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1. Miss Tompkins gave the same English grammar assessment to her students twice, once on Monday and then two weeks later. Her students scored almost exactly the same on both tests. Why does this assessment seem reliable? 2. Mr. Lucas wrote two forms of the same test. Each form had different questions. He gave Form 1 to half his students and Form 2 to the other half. The students taking Form 1 scored 11 percentage points higher than those taking Form Why does this assessment seem unreliable? 3. Mr. Sorza gave a multiplication test to his students once a month. Each month he was surprised when a different group of students scored well. Why does this assessment seem unreliable? 4. Mrs. McCarlson is testing her physical education student’s vertical leap. She will be using a yardstick and taking the average measurement from 3 jumps per student. Why does this assessment seem reliable? 1. Miss Lund graded her students on a semester exam that only included content they had covered during the last five weeks. Why doesn’t this assessment seem valid? 2. Mr. Bach’s 4th grade students scored almost the same on his end-of-year math tests as they did on the statewide math tests. Why does this assessment seem valid? 3. Mr. Lee gave true and false geography tests to his students to determine the three students who might do well in the geography bee. The three students who did the best were eliminated in the first round. Why doesn’t this assessment seem valid? 4. Ms. Kwan’s objective is to determine if her students are able to identify the correct use of a vocabulary word. She provides her students with the definition of the word along with 4 separate sentences containing the word. Based on the definition provided, students must select which sentence uses the vocabulary word correctly. Why does this assessment seem valid?
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Calif. Plants Put A Wrinkle In Climate Change Plans
As the globe warms up, many plants and animals are moving uphill to keep their cool. Conservationists are anticipating much more of this as they make plans to help natural systems adapt to a warming planet. But a new study in Science has found that plants in northern California are bucking this uphill trend in preference for wetter, lower areas.
Usually, coping with climate change is an uphill struggle for ecosystems �?�¢?? literally. Plants and animals want to be in a temperature zone where they can survive best.
"We see it consistently for mobile species such as insects and animals," says Solomon Dobrowski, an assistant professor of forest landscape ecology at the University of Montana. "A lot of the real foundation studies of this have come out of studies of butterflies, for example."
Dobrowski expected he'd see the same trend when he looked into historical movements of plants in a vast area of northern California. He dug through a remarkable record of the region's vegetation, collected back in the 1930s thanks to a federal project started during the Great Depression. He and his colleagues from the University of Idaho and the University of California, Davis, then compared that with modern vegetation surveys.
"What we found was counter to our expectations," he says. "We found that in fact the preponderance of plants in our study area had actually moved downhill 80 meters, or roughly 240 feet."
Water Availability Is Key
Individual plants don't move, of course, but the optimal range of many different species in the area studied has been creeping downhill. That means more new seeds sprouted downhill, and more new plants took root. This was true not just for annual plants but also for bushes and even trees.
Why would that be, Dobrowski wondered, considering that the area has warmed up. He and his colleagues say the answer lies not in the temperature, but in the amount of life-giving rain and snow. It turns out this region has been getting wetter.
"These plants are tracking water availability more so than temperature," he says.
Until now, ecologists doing this kind of study had mostly noticed a trend linked with temperature. Dobrowski says that still holds in many cases. But "the simple message �?�¢?? that things are going to move uphill and toward the poles �?�¢?? may not be the answer in all cases."
Disruptions In Ecosystems
This adds some pretty big wrinkles to conservation plans. For example: It's not always a good assumption that protecting areas up slope from plants will help protect their future habitat as the climate changes.
Dobrowski says if ecosystems see their optimal temperature range moving uphill and their water supply moving downhill, that could be quite awkward at times. What if plants move downhill to better moisture conditions, but the butterflies that rely on those plants are driven uphill to avoid the heat?
"You could have situations in which plant and animal communities are even disrupted further," he says.
This is quite a sobering finding for ecologists trying to anticipate what will happen to natural systems in the coming century.
Scott Loarie, a researcher at the Carnegie Institution of Science on the Stanford University campus, says most of the research into this topic has been focused on temperature trends, "because we know the most about temperature. Pretty much all our evidence shows the Earth will get hotter, and there's very little dispute about that. We don't know very much about precipitation."
Loarie says the new study underlines just how important precipitation can be. Unfortunately, in many parts of the world, scientists simply can't say whether climate change in the long run will bring more moisture or more drought. Loarie says California is a case in point �?�¢?? the various climate forecasts disagree.
"So it's really a crapshoot in California whether we're facing a drier or a wetter future," he says.
That means it's entirely possible that the plant communities that have been marching downhill for the past 80 years will eventually reverse course, and head back up the slopes.
Source: NPR [http://www.npr.org/2011/01/21/133092677/calif-plants-put-a-wrinkle-in-climate-change-plans?ft=3&f=1003,1004,1007,1013,1014,1017,1019,1128] |
Memories and the feelings associated with them are not set in stone. You may have happy memories about your family’s annual ski vacation, but if you see a tragic accident on the slopes, those feelings may change. You might even be afraid to ski that mountain again.
Now, using a technique in which light is used to switch neurons on and off, neuroscientists at the Massachusetts Institute of Technology appear to have unlocked some secrets about how the brain attaches emotions to memories and how those emotions can be adjusted.
Their research, published Wednesday in the journal Nature, was conducted on mice, not humans, so the findings cannot immediately be translated to the treatment of patients. But experts said the experiments may eventually lead to more effective therapies for people with psychological problems such as depression, anxiety or post-traumatic stress disorder.
“Imagine you can go in and find a particular traumatic memory and turn it off or change it somehow,” said David Moorman, an assistant professor of psychological and brain sciences at the University of Massachusetts Amherst, who was not involved in the research. “That’s still science fiction, but with this we’re getting a lot closer to it.”
The M.I.T. scientists labeled neurons in the brains of mice with a light-sensitive protein and used pulses of light to switch the cells on and off, a technique called optogenetics. Then they identified patterns of neurons activated when mice created a negative memory or a positive one.
A negative memory formed when mice received a mild electric shock to their feet; a positive one was formed when the mice, all male, were allowed to spend time with female mice.
Later, mice that had been shocked were put in the company of females, a positive experience, while scientists used the light to activate the memory of the shock. As a result, the negative memory became less negative: The mice became less fearful in the place where they had been conditioned to remember the shock.
The mice that originally spent time with the females later received mild electric shocks while scientists activated the neurons associated with this positive memory. The memory became less enticing, the scientists concluded: The mice froze more and sniffed less, standard measures of fear and reward in rodents.
The study’s senior author, Susumu Tonegawa, a professor of biology and neuroscience at M.I.T., said the findings provided a neurological basis for psychotherapy in which patients are encouraged to unearth a good memory to “reduce the feelings of a bad memory they have or stress they have had.”
Roger L. Redondo, a postdoctoral student and one of the study’s lead authors, said the experiments showed it was possible to alter the emotional perception of a memory “without any drugs and without the mice being brought back to the area where the memory occurred.”
The scientists also discovered important differences in the way neurons work in two important brain areas, the hippocampus and the amygdala. The hippocampus is involved in forming new memories and encoding factual details like where, what and when. The amygdala helps link emotions to memory.
The experiments found that neurons in the hippocampus can be changed to make a bad memory less negative, and vice versa. But neurons in the amygdala did not change, leading scientists to conclude that those neurons are prewired to reflect positive or negative emotions.
“That’s absolutely new,” said Richard Morris, a neuroscientist at the University of Edinburgh who was not involved in the research. He said it made sense that the amygdala would have specialized neurons, because it connects to several brain areas involved in taking action.
The brain must understand quickly if an experience is, say, fearful or rewarding, so it can coordinate its response, he said.
Susan Sangha, an assistant professor of psychological sciences at Purdue University who has studied neurons in the amygdala, said an important question was “what is special about these neurons.” Her research has suggested that besides reward and fear, some neurons transmit feelings of safety, and some seem to fire with any emotion.
Joshua P. Johansen, a neuroscientist at the Riken Brain Science Institute in Japan who was not involved in the research, said the findings “provide clues as to how we go about tackling things like anxiety disorder.”
He cautioned that the research was in its infancy and that it involved normal behaviors, not disorders. But, Dr. Johansen said, “if we can figure out how to associate bad experiences with neutral or pleasurable experiences,” it could guide development of drugs, gene therapy or other treatments for mental illness.
Current optogenetics techniques are not appropriate for people because they involve inserting fiber optic wires and injecting a virus containing a protein into the brain.
But the researchers said noninvasive techniques were already being explored. “It’s not something we can do next week or next year, but people are now developing a variety of methods,” Dr. Tonegawa said. “Technology develops so fast these days, so I’m quite optimistic.” |
Fractions SupportORTi Presentation October 2016ResourcesThis book shows the progression of learning fractions at each grade level, K-7. It shows models and ideas for helping all students understand the fraction concepts.See the progressions and go back to fill holes with Turnonccmath.net---Click the standard you are teaching at grade level. Then see what builds up to that standard. This is helpful to figure out how to intervene for a student and fill their holes.VideosGrade 3 (6 min.)Grade 3 (16 min.)Grades 3-5 (5 min.)Grade 4-5 (13 min.)Grade 4 (14 min.)Grade 3-5 (9 min.)Grade 5-8 (9min.)Grade 4 (23 min.)Grade 4 (14 min.)Grades 5 (7 min.)Try these websites for repetitive practice with your students.Try these apps for practice and intervention with your studentsCheck out number line and Geoboard app too! |
Ever wondered what natural sounds you would hear on another planet? Although some spacecraft have carried microphones, sound has never been reliably recorded in an alien atmosphere. But now, thanks to simulations created by Tim Leighton from the University of Southampton, UK, and his team, you can hear what Mars and Venus would sound like.
In this video, you can listen to the recreated sound of a waterfall, thunder and a human voice on different planets and on Titan. Leighton used physics models to produce the sound of thunder and waterfalls in the different atmospheres, whereas the voice was morphed fromrecordings. "On Venus, the atmosphere is thick and soupy so vocal chords that would flutter lightly on Earth would vibrate more slowly," says Leighton. "As a result, the pitch of your voice drops."
In addition to changing the speed of moving vocal chords, different atmospheres affect the speed of sound itself. On Venus, sound travels faster, resulting in echoes moving quickly through a person's windpipe. This could confuse a listener, making it seem like the person has a short windpipe and therefore is small. "You would sound like a bass Smurf," says Leighton.
The sounds will be heard publicly for the first time tonight as part of a show at the Intech planetarium in Winchester, UK. But simulating sounds on other planets could have applications beyond entertainment. Using the same models, engineers could predict how vanes and struts on probes might vibrate or become fatigued during a mission. The simulations could also be used to design acoustic instruments calibrated to a specific planet's atmosphere. |
Parkinson’s disease – Knowing the facts
Parkinson's disease is a chronic, degenerative condition affecting the central nervous system that results in decreased movement. This happens due to decreased production of the hormone, dopamine, in the brain which results in gradually decreased movements.
Parkinson's disease is a chronic, degenerative condition affecting the central nervous system that results in decreased movement. This happens due to decreased production of the hormone, dopamine, in the brain which results in gradually decreased movements. Parkinson’s disease belongs to the group of conditions known as motor system disorders.
The symptoms of Parkinson’s disease include the following:
• Tremor or shaking that begins in a limb, usually the fingers or hands. The characteristic sign of Parkinson’s disease is if this tremor occurs when the patient is at rest. Also, the thumb and forefingers rub against each other, and this resembles counting of coins.
• There’s a reduced ability to move and movement slows down. Steps become shorter when walking and it becomes more difficult to get out of a chair. As one walks, dragging of the feet may occur. This is called a shuffling gait.
• Muscle stiffness may occur in any part of your body. This limits the affected individual’s range of motion and may cause pain.
• Posture can become stooped, or the patient’s balance can become affected.
• Automatic movements such as smiling or blinking may disappear.
• Slurred speech, hesitating to talk, speaking softly and being monotonous are changes that can occur.
• Writing can become difficult and may appear small.
People who are at risk of developing Parkinson’s disease include those who are 60 years of age or older, having a strong family history of the condition, being male and constant exposure to toxins such as pesticides and herbicides.
Complications associated with Parkinson's disease may include problems such as memory impairment (dementia), depression and emotional changes such as anxiety, fear and loss of motivation, difficulties with swallowing, drooling, sleeping problems, urinary incontinence, difficulty urinating and constipation. Other possible complications may also include feeling lightheaded or dizzy due to a sudden drop in blood pressure when standing up (orthostatic hypotension), impaired sense of smell, fatigue, generalized body pains and a decrease in sexual desire or performance.
Unfortunately, there is no cure for Parkinson's disease. Pharmacological medications are available though that are effective in controlling the symptoms caused by this movement disorder. These include drugs such as the widely used combination of carbidopa and levodopa, dopamine agonists, anticholinergics and amantadine.
Lifestyle changes, such as aerobic exercises including walking, gardening, swimming, water aerobics, dancing and stretching, can be suggested by healthcare professionals. The incorporation of physical therapy and exercise is very important to increase muscle strength and flexibility, as this helps to improve the affected patient’s balance and coordination. Exercise also helps to improve one’s well-being and reduce emotional changes such as anxiety and depression. A speech therapist is included to help improve any speech-related issues, and an occupation therapist shows the patient techniques regarding how to dress, eat, write and bathe which helps make daily life easier.
Eating a healthy and well balanced diet helps to avoid complications of Parkinson’s disease such as constipation. A diet high in fibre and an adequate water intake helps to avoid such as issue. A diet high in omega-3, through fatty fish intake, is also beneficial for patients diagnosed with this movement disorder. |
Kyphosis, commonly known as "humpback" or "round back," is a deformity of the spine caused by an external growth of the spine. The spine of the human body has curves that allow people to stand, sit, and walk upright. If the curves of the spine are too large or too small for biological reasons, it causes problems in our standing and sitting posture, and our body does not look normal. The range of curvature of the thoracic spine varies from 20 to 45 degrees. Curves beyond this range become the cause of the concern and are known in medical terms as curvatures. It can affect people of any age, but a medical history suggests a greater risk of developing the disease in adolescence, when bone growth is at its peak. Postural curvature leads to the development of a smooth, rounded curve that causes poor or sagging posture. Scheuermann's kyphosis is of a more severe nature and condition than the first. The vertebrae are triangular rather than rectangular because they wedge forward of the spine, causing a hard and sharp curve. Congenital kyphosis develops in the womb when the bones do not form as they should or the vertebrates fuse together. The situation worsens over time as the child grows older. |
A graph G is planar if it can be drawn in the plane in such a way that no two edges meet each other except at a vertex to which they are incident. Any such drawing is called a plane drawing of G.
For example, the graph K4 is planar, since it can be drawn in the plane without edges crossing.
The three plane drawings of K4 are:
The five Platonic graphs are all planar.
On the other hand, the complete bipartite graph K3,3 is not planar, since every drawing of K3,3 contains at least one crossing. why? because K3,3 has a cycle which must appear in any plane drawing.
To study planar graphs, we restrict ourselves to simple graphs.
- If a planar graph has multiple edges or loops.
- Collapse the multiple edges to a single edge.
- Remove the loops.
- Draw the resulting simple graph without crossing.
- Insert the loops and multiple edges.
Remove loops and multiple edge.
Draw without multiple edge.
Insert loops and multiple edges.
If G is a planar graph, then any plane drawing of G divides the plane into regions, called faces. One of these faces is unbounded, and is called the infinite face. If f is any face, then the degree of f (denoted by deg f) is the number of edges encountered in a walk around the boundary of the face f. If all faces have the same degree (g, say), the G is face-regular of degree g.
For example, the following graph G has four faces, f4 being the infinite face.
It is easy to see from above graph that deg f1=3, deg f2=4, deg f3=9, deg f4=8.
Note that the sum of all the degrees of the faces is equal to twice the number of edges in the the graph , since each edge either borders two different faces (such as bg, cd, and cf) or occurs twice when walk around a single face (such as ab and gh). The Euler's formula relates the number of vertices, edges and faces of a planar graph. If n, m, and f denote the number of vertices, edges, and faces respectively of a connected planar graph, then we get n-m+f = 2.
The Euler formula tells us that all plane drawings of a connected planar graph have the same number of faces namely, 2+m-n.
Theorem 1 (Euler's Formula) Let G be a connected planar graph, and let n, m and f denote, respectively, the numbers of vertices, edges, and faces in a plane drawing of G. Then n - m + f = 2.
Proof We employ mathematical induction on edges, m. The induction is obvious for m=0 since in this case n=1 and f=1. Assume that the result is true for all connected plane graphs with fewer than m edges, where m is greater than or equal to 1, and suppose that G has m edges. If G is a tree, then n=m+1 and f=1 so the desired formula follows. On the other hand, if G is not a tree, let e be a cycle edge of G and consider G-e. The connected plane graph G-e has n vertices, m-1 edges, and f-1 faces so that by the inductive hypothesis,
n - (m - 1) + (f - 1) = 2
which implies that
n - m + f = 2.
We can obtains a number of useful results using Euler's formula. (A "corollary" is a theorem associated with another theorem from which it can be easily derived.)
Corollary 1 Let G be a connected planar simple graph with n vertices, where n ≥ 3 and m edges. Then m ≤ 3n - 6.
Proof For graph G with f faces, it follows from the handshaking lemma for planar graph that 2m ≥ 3f (why?) because the degree of each face of a simple graph is at least 3), so f ≤ 2/3 m.
Combining this with Euler's formula
Since n - m + f = 2
We get m - n + 2 ≤ 2/3 m
Hence m ≤ 3n - 6.
As an example of Corollary 1, show that K5 is non-planar.
Proof Suppose that K5 is a planar graph. Since K5 has 5 vertices and 10 edges it follows from Corollary 1 that 10 (3 × 5) - 6 = 9. This contradiction shows that K5 is non planar.
It is important to note that K3,3 has 6 vertices and 9 edges, and it is true that 9 ≤ (3 × 6) - 6 = 12. This fact simply shows that we cannot use Corollary 1 to prove that K3,3 is non-planar. This leads us to following corollary.
Corollary 2 Let G be a connected planar simple graph with n vertices and m edges, and no triangles. Then m ≤ 2n - 4.
Proof For graph G with f faces, it follows from the handshaking lemma for planar graphs that 2m ≥ 4f (why because the degree of each face of a simple graph without triangles is at least 4), so that f ≤ 1/2 m.
Combining this with Euler's formula
Since n - m + f = 2
Implies m -n + 2 = f
We get m - n + 2 ≤ 1/2m
Hence m ≤ 2n - 4
As an example of Corollary 2, show that K3,3 is non-planar.
Proof Suppose that K3,3 is a planar graph. Since K3,3 has 6 vertices and 9 edges and no triangles, it follows from Corollary 2 that 9 ≤ (2×6) - 4 = 8. This contradiction shows that K3,3 is non-planar.
Corollary 3 Let G be a connected planar simple graph. Then G contains at least one vertex of degree 5 or less.
Proof From Corollary 1, we get m ≤ 3n-6. Suppose that every vertex in G has degree 6 or more. Then we have 2m ≥ 6n (why? because 2m is the sum of the vertex-degree), and therefore m≥3n. This contradiction shows that at least one vertex has degree 5 or less.
Now we will show by using Euler's formula that there are only five regular convex polyhedra - namely, the tetrahedron, cube, octahedron, dodecahedron, and isosahedron.
Theorem 2 There are only 5 regular convex polyhedra.
Proof We prove this theorem by showing that there are only 5 connected planar graph G with following properties.
- G is regular of degree d, where d≥3.
- Any plane drawing of G is face-regular of degree g where g≥3.
Let n, m and f be the numbers of vertices, edges, and faces of such a planar graph G. Then, from properties (i) and (ii), we ge
m = 1/2 dn
= 1/2 gf
This gives us n = 2m/d and f = 2m/g
Here Euler's formula (n - m + f = 2) holds, since G is a planar graph.
Therefore, 2m/d - m + 2m/g = 2
Which can be written as 1/d - 1/2 + 1/g = 1/m
Since 1/m > 0, it follows that 1/d + 1/g > 1/2
Note that each of d and g is at least 3, so each of
1/d and 1/g is at most
Therefore, 1/d > 1/2 - 1/3 = 1/6 and 1/g > 1/2 - 1/3 = 1/6.
and we conclude that d < 6 and g < 6.
This means that the only possible values of d and g are 3, 4, and 5. However, if both d and g are greater than 3, then
1/d + 1/g ≤ 1/4 + 1/4 = 1/2
which is a contradiction. This leaves us with just five cases:
Case 1: When
d = 3 and
g = 3.
we get 1/m = 1/3 - 1/2 + 1/3 = 1/6
Therefore m = 6
It follows that n = 8 and f = 4 and this gives the Tetrahedron.
Case 2: When d = 3
and g = 4.
we get 1/m = 1/3 - 1/2 + 1/4 = 1/12
Therefore m = 12
It follows that n = 8 and f = 6 and this gives the Cube.
Case 3: When d = 3
and g = 5.
we get 1/m = 1/3 - 1/2 + 1/5 = 1/30
Therefore m = 30
It follows that n = 20 and f = 12 and this gives the Dodecahedron.
Case 4: When d = 4
and g = 3.
we get 1/m = 1/4 - 1/2 + 1/3 = 1/12
Therefore m = 12
It follows that n = 6 and f = 8 and this gives the Octahedron.
Case 5: When d = 5
and g = 3.
we get 1/m = 1/5 - 1/2 + 1/3 = 1/30
Therefore m = 30
It follows that n = 12 and f = 20 and this gives the Icosahedron.
And this completes the proof.
The Corollaries 1, 2 and their generalization are often useful for showing that graph is not planar. Unfortunately, there are many graphs which satisfy these inequalities but are not planar. Therefore, we need other way to decide planarity.
Some important observations:
- Observation 1
- Not all graphs are planar.
- For example, we know K5 and K3,3 are not planar.
- Observation 2
- If G is a planar graph, then every subgraph of G is planar;
- We usually stated observation 2 as follows
- Observation 2a
- If G contains a nonplanar graph as a subgraph, then G is non-planar. For example, following graph is nonplanar
- Since it contains K5 as a subgraph.
- The following graph is also non-planar
- Since the it contains K3,3 as a subgraph.
- Observation 3
- If G is a planar graph, then every subdivsion of G is planar, we usually stated observation 3 in the following way.
- Observation 3a
- If G is a subdivision of a non-planar graph, then G is non-planar.
- For example, following graph is non-planar,
- Since it is a subdivision of K5.
- Also, the following graph is non-planar,
- Since it is a subdivision of K3,3.
It follows from observations (2a) and (3a) that, if any graph G contains a subdivision of K5 and K3,3 as a subgraph, then G must be non-planar.
Why are we so obsessed with K5 and K3,3? The reason is that all non-planar graphs can be obtained by adding vertices and edges to a subdivision of K5 and K3,3.
Every non-planar graph contains K5 or K3,3 as a subgraph.
Following result is due to the Polish mathematician K. Kuratowski.
Theorem 3 A graph is planar if and only if it does not contain a subdivision of K5 and K3,3 as a subgraph.
In the following figure contradiction is done by bringing the vertex w closer and closer to v until w and v coincide and then coalescing multiple edges into a single edge.
Bring vertex w closer to v.
Coalesce vertex v and vertex w.
Finally, coalesce multiple edges and we have
A contraction of a graph is the result of a sequence of edge-contractions. For example, K5 is a contraction of the Petersen graph
Theorem 4 A graph is planar if and only if it does not contain a subgraph which has K5 and K3,3 as a contraction.
The basic idea to test the planarity of the given graph is if we are able to
spot a subgraph which is a subdivision of K5 or K3,3 or a subgraph which
contracts to K5 or K3,3 then a given graph is non-planar.
Theorems 3 and 4 give us necessary and sufficient conditions for a graph to be planar in purely graph-theoretic sense (subgraph, subdivision, K3,3, etc) rather than geometric sense (crossing, drawing in the plane, etc). This is the reason, why there exists no algorithm uses these two theorems for testing the planarity of a graph. Since this would involve looking at a large number of subgraph and verifying that none of them is a subdivision of, or contracts toK5 or K3,3.
Given a connected planar graph G, we construct dual graph G* in three stages.
- Take a plane drawing of G.
- Choose one point inside each face of the plane drawing - these points are the vertices of G*.
- For each e of the plane drawing, draw a line connecting the vertices of G* on each side of e.
This procedure is illustrated as follows:
Note that each plane drawing of G given rise to just one dual graph G*.
Following theorem illustrates a simple relationship between the number of vertices, faces and edges of a graph and its dual.
Theorem 6 If G is a connected planar graph with n vertices, f faces and m edges, then G* has f vertices, n faces and m edges.
In the above example, G has 5 vertices, 4 faces and 7 edges, and G* has 4 faces, 5 faces, and seven edges.
Note that if G is a connected planar graph, then G* is also connected planar graph. |
On Sept. 20, the Obama Administration continued its efforts to combat climate change by proposing new standards that will limit dangerous carbon pollution from new power plants.
The Environmental Protection Agency's (EPA) new requirements were enacted to fight climate change from carbon pollution, and pave the way for clean energy technologies. The draft rule requires that all new power plants built in the U.S. limit their emissions to less than 1,100 pounds of carbon pollution per megawatt-hour. The rule is part of a comprehensive strategy to address climate change outlined by the president in June, 2013.
When the EPA proposed its first draft of the standards last year, it received more than 3.2 million comments in favor of curbing carbon pollution from power plants—the most the agency has ever received on any issue in its history. A July survey conducted by Hart Research for NRDC found that 65 percent of Americans endorse setting limits on carbon pollution from power plants. This includes 49 percent of Republicans, 56 percent of independents, and 84 percent of Democrats.
Although the proposed rule won't immediately affect plants already operating, it is an important step towards limiting emissions from the existing power plant fleet, which accounts for a third of all U.S. greenhouse gas emissions.
The following statement on today’s EPA announcement is from Chase Huntley, Government Relations Director for the energy program at The Wilderness Society.
“This is exciting news for our shared wild places. Forests, prairies and other natural areas are on the front lines of climate change. These areas will feel some of the first effects of drier summers, warmer winters and extreme weather. Our public lands are also the places that can provide refuge and help insulate communities from some of the worst effects of climate change.
We welcome this important step towards realizing the climate goals set forth in President Obama’s climate action plan. The plan is clear – we have to be smarter about how we power our nation and how we manage our public lands. Bringing more clean, renewable, energy sources online will help wean our dependence from these same climate change-causing fossil fuels. By guiding development to places with the least amount of conflict, we can simultaneously protect our irreplaceable wild lands, the very places that will help us absorb the impacts of climate change.
Administrator McCarthy’s leadership in doing what Congress has been unwilling or unable to do – taking steps to reign in carbon emissions- will have a positive impact on our country and its land, air and water for generations to come.” |
Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus. Since neutrons have no electric charge, they can enter a nucleus more easily than positively charged protons, which are repelled electrostatically.
Neutron capture plays an important role in the cosmic nucleosynthesis of heavy elements. In stars it can proceed in two ways: as a rapid (r-process) or a slow process (s-process). Nuclei of masses greater than 56 cannot be formed by thermonuclear reactions (i.e. by nuclear fusion), but can be formed by neutron capture. Neutron capture on protons yields a line at 2.223 MeV, predicted and commonly observed in solar flares.
Neutron capture at small neutron fluxEdit
At small neutron flux, as in a nuclear reactor, a single neutron is captured by a nucleus. For example, when natural gold (197Au) is irradiated by neutrons, the isotope 198Au is formed in a highly excited state, and quickly decays to the ground state of 198Au by the emission of γ rays. In this process, the mass number increases by one. This is written as a formula in the form 197Au+n → 198Au+γ, or in short form 197Au(n,γ)198Au. If thermal neutrons are used, the process is called thermal capture.
Neutron capture at high neutron fluxEdit
The r-process happens inside stars if the neutron flux density is so high that the atomic nucleus has no time to decay via beta emission in between neutron captures. The mass number therefore rises by a large amount while the atomic number (i.e., the element) stays the same. Only afterwards, the highly unstable nuclei decay via many β− decays to stable or unstable nuclei of high atomic number.
Capture cross sectionEdit
The absorption neutron cross-section of an isotope of a chemical element is the effective cross sectional area that an atom of that isotope presents to absorption, and is a measure of the probability of neutron capture. It is usually measured in barns (b).
Absorption cross section is often highly dependent on neutron energy. As a generality, the likelihood of absorption is proportional to the time the neutron is in the vicinity of the nucleus. The time spent in the vicinity of the nucleus is inversely proportional to the relative velocity between the neutron and nucleus. Other more specific issues modify this general principle. Two of the most commonly specified measures are the cross-section for thermal neutron absorption, and resonance integral which considers the contribution of absorption peaks at certain neutron energies specific to a particular nuclide, usually above the thermal range, but encountered as neutron moderation slows the neutron down from an original high energy.
The thermal energy of the nucleus also has an effect; as temperatures rise, Doppler broadening increases the chance of catching a resonance peak. In particular, the increase in uranium-238's ability to absorb neutrons at higher temperatures (and to do so without fissioning) is a negative feedback mechanism that helps keep nuclear reactors under control.
Neutron capture is involved in the formation of isotopes of chemical elements. As a consequence of this fact the energy of neutron capture intervenes in the standard enthalpy of formation of isotopes.
Neutron activation analysis can be used to remotely detect the chemical composition of materials. This is because different elements release different characteristic radiation when they absorb neutrons. This makes it useful in many fields related to mineral exploration and security.
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The most important neutron absorber is 10B as 10B4C in control rods, or boric acid as a coolant water additive in PWRs. Other important neutron absorbers that are used in nuclear reactors are xenon, cadmium, hafnium, gadolinium, cobalt, samarium, titanium, dysprosium, erbium, europium, molybdenum and ytterbium; all of which usually consist of mixtures of various isotopes—some of which are excellent neutron-absorbers. These also occur in combinations such as Mo2B5, hafnium diboride, titanium diboride, dysprosium titanate and gadolinium titanate.
Hafnium, one of the last stable elements to be discovered, presents an interesting case. Even though hafnium is a heavier element, its electron configuration makes it practically identical with the element zirconium, and they are always found in the same ores. However, their nuclear properties are different in a profound way. Hafnium absorbs neutrons avidly (Hf absorbs 600 times more than Zr), and it can be used in reactor control rods, whereas natural zirconium is practically transparent to neutrons. So, zirconium is a very desirable construction material for reactor internal parts, including the metallic cladding of the fuel rods which contain either uranium, plutonium, or mixed oxides of the two elements (MOX fuel).
Hence, it is quite important to be able to separate the zirconium from the hafnium in their naturally occurring alloy. This can only be done inexpensively by using modern chemical ion-exchange resins. Similar resins are also used in reprocessing nuclear fuel rods, when it is necessary to separate uranium and plutonium, and sometimes thorium.
- Ahmad, Ishfaq; Hans Mes; Jacques Hebert (1966). "Progress of theoretical physics: Resonance in the Nucleus". Institute of Physics. Ottawa, Canada: University of Ottawa (Department of Physics). 3 (3): 556–600.
- Morrison, P. "On gamma-ray astronomy".
- Chupp, E.; et al. "Solar Gamma Ray and Neutron Observations".
- Prompt Gamma-ray Neutron Activation Analysis. International Atomic Energy Agency
- D. Franklin; R. B. Adamson (1 January 1984). Zirconium in the Nuclear Industry: Sixth International Symposium. ASTM International. pp. 26–. ISBN 978-0-8031-0270-5. Retrieved 7 October 2012. |
Biking, Walking & Bus Safety
Hundreds of cyclists are killed, and thousands injured, each year while navigating the nation's roadways. Bicycle riders can help prevent crashes by following a few basic rules of the road:
- Always wear an approved bicycle safety helmet to protect your head from serious injury when riding.
- Before riding out of a driveway, parking lot or sidewalk into the street, stop and look left, right and left again for traffic.
- Ride on the right–hand side of the street in the same direction as the flow of automobile traffic.
- When riding with others, form a single line, one bike length apart, on the right–hand side of the roadway.
- Stop at all stop signs and look left, right, and left again for traffic.
- Walk your bike across busy roads and intersections.
- Use hand signals to show others that you are stopping or making a turn.
- Help other drivers to see you. Wear light or brightly colored clothing.
- On streets where cars are parked, watch for car doors opening into the roadways.
- Avoid riding after dark or if the weather is bad. All cyclists are at risk during the hours of darkness.
- Give cars and pedestrians the right–of–way. It's an act of courtesy, and it's safer, too.
- Obey traffic signs, signals and pavement markings. Obeying the law can keep you out of many hazardous driving situations.
- Avoid broken pavement, litter, loose gravel, mud, or leaves. Any of these can cause you to lose control of your bike.
- Look all ways before crossing at crosswalks.
- Keep to the right in the crosswalk. At signalized crosswalks, cross only on proper signal.
- Avoid crossing between parked cars.
- Where there is no sidewalk and it is necessary to walk in the roadway, walk on left side, facing traffic.
- Wear or carry retro–reflective material at night to help drivers see you.
Tips For Safe School Bus Riding
For a safe and enjoyable ride to and from school, follow these rules:
- Leave home early enough to arrive at your bus stop on time.
- Wait for your bus in a safe place well off the roadway.
- Enter your bus in an orderly manner and take your seat.
- Follow the instructions of your school bus driver or bus patrol.
- Remain in your seat while your bus is in motion.
- Keep your head and arms in the bus at all times.
- Keep aisles clear at all times.
- Remain quiet and orderly.
- Be courteous to your school bus driver and fellow passengers.
- Be alert to traffic when leaving the bus. |
Difference Between Sample Mean and Population Mean
Sample Mean vs Population Mean
When the provided list represents a statistical population, then the mean is called the population mean. It is usually denoted by the letter “µ.”
When the provided list represents a statistical sample, then the mean is called the sample mean. The sample mean is denoted by “X.” It is a satisfactory estimate of the population mean.
For a sample, a population mean may be defined as:
µ = Σ x / n where;
Σ represents the sum of all the number of observations in the population;
n represents the number of observations taken for the study.
When frequency is also included in the data, then the mean may be calculated as:
µ = Σ f x / n where;
f represents the class frequency;
x represents class value;
n represents the size of the population, and
Σ represents the summation of the products “f” with “x” all over the classes.
In the same way the sample mean will be;
X = Σ x / n or
µ = Σ f x / n where “n” is the number of observations.
In a more elaborate way it may be represented as;
X = x₁ + x₂ + x₃ +…………….xn / n or
X = 1/n(x₁ + x₂ + x₃ +…………….xn ) = Σ x / n
This can be cleared with the following example:
Suppose the data has the following observations of a study.
1, 2, 2, 3, 3, 4, 5, 6, 7, 8
For these samples to take out the sample mean, we will consider several samples and consider the mean.
For 1, 2, 3, mean will be calculated as (1+ 2+3/ 3) = 2;
For 3, 4, 5, mean will be calculated as (3 +4 + 5/3) = 4;
For 4, 5, 6, 7, 8, mean will be calculated as (4 +5+6 +7 +8/5) = 6;
And for 3, 3, 4, 5, mean will be calculated as (3 + 3 +4 + 5/4) = 3.75.
Thus the total mean of these samples is (2 + 4+ 6 + 3.75/ 4) = 3.94 or approximately 4.
This value is called the sample mean.
Now for the population, the population mean can be calculated as:
1+ 2+ 2+ 3+ 3+4+5+ 6+7+ 8/10 = 4.1
Thus the sample mean is very close to the population mean. The accuracy increases with an increase in the number of samples taken.
1.A sample mean is the mean of the statistical samples while a population mean is the mean of the total population.
2.The sample mean provides an estimate of the population mean.
3.A sample mean is more manageable data while a population mean is difficult to calculate.
4.The sample mean increases its accuracy to the population mean with the increased number of observations.
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New research findings from the Centre for Permafrost (CENPERM) at the Department of Geosciences and Natural Resource Management, University of Copenhagen, document that permafrost during thawing may result in a substantial release of carbon dioxide into the atmosphere and that the future water content in the soil is crucial to predict the effect of permafrost thawing. The findings may lead to more accurate climate models in the future.
The permafrost is thawing and thus contributes to the release of carbon dioxide and other greenhouse gases into the atmosphere. But the rate at which carbon dioxide is released from permafrost is poorly documented and is one of the most important uncertainties of the current climate models.
The knowledge available so far has primarily been based on measurements of the release of carbon dioxide in short-term studies of up to 3-4 months. The new findings are based on measurements carried out over a 12-year period. Studies with different water content have also been conducted. Professor Bo Elberling, Director of CENPERM (Centre for Permafrost) at the University of Copenhagen, is the person behind the novel research findings which are now being published in the internationally renowned scientific journal Nature Climate Change.
"From a climate change perspective, it makes a huge difference whether it takes 10 or 100 years to release, e.g., half the permafrost carbon pool. We have demonstrated that the supply of oxygen in connection with drainage or drying is essential for a rapid release of carbon dioxide into the atmosphere," says Bo Elberling.
Water content in the soil crucial to predict effect of permafrost thawing
The new findings also show that the future water content in the soil is a decisive factor for being able to correctly predict the effect of permafrost thawing. If the permafrost remains water-saturated after thawing, the carbon decomposition rate will be very low, and the release of carbon dioxide will take place over several hundred years, in addition to methane that is produced in waterlogged conditions. The findings can be used directly to improve existing climate models.
The new studies are mainly conducted at the Zackenberg research station in North-East Greenland, but permafrost samples from four other locations in Svalbard and in Canada have also been included and they show a surprising similarity in the loss of carbon over time.
"It is thought-provoking that microorganisms are behind the entire problem - microorganisms which break down the carbon pool and which are apparently already present in the permafrost. One of the critical decisive factors - the water content - is in the same way linked to the original high content of ice in most permafrost samples. Yes, the temperature is increasing, and the permafrost is thawing, but it is, still, the characteristics of the permafrost which determine the long-term release of carbon dioxide," Bo Elberling concludes.
Link to the scientific article
Professor Bo Elberling, Director of CENPERM, Centre for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K. Mobile: + 45 2363 8453.
The core funding for the Centre for Permafrost for the 2012-2018 period is a Centre of Excellence grant from the Danish National Research Foundation. CENPERM is an interdisciplinary project studying the biological, geographical and physical effects of permafrost thawing in Greenland.
The studies combine field studies in Greenland under extreme conditions with laboratory experiments under controlled conditions. The studies are intended to decode the complex interaction between microorganisms, plants and soil during permafrost thawing.
Permafrost and carbon
Permafrost is layers of soil and sediments which remain frozen for more than two consecutive years, while the active layer is the top layer of soil which thaws during the summer.
In Arctic areas with so-called continuous permafrost, the permafrost may be several hundred metres deep. The permafrost contains large amounts of organic matter, because the pool is built up over several thousand years. The pool can be extremely large and includes old top layers containing organic material which have been buried by wind or water-deposited sediments.
This means that near-surface layers, over time, will become a part of the permafrost. In addition, the decomposition rate of the pool of organic matter is slow during the generally cold conditions in the Arctic. It is well-documented that carbon in organic matter can be decomposed when permafrost layers thaw, and that these decomposition processes can contribute to a significant release of both carbon dioxide and methane - two well-known and problematic greenhouse gases.
How rapidly thaws the permafrost
Observations from Greenland may provide the answer to the question of how rapidly the permafrost thaws. The depth of the active layer in Zackenberg in North-East Greenland has been measured at the end of the growth season since 1996.
The measurements show that the depth of the active layer increases by more than 1 cm per year, which means that, as a minimum, more than 1 cm of permafrost thaws every year. This is the minimum figure, because permafrost, due to its content of ice, will typically decrease in size after thawing and becoming a part of the active layer.
The Danish Meteorological Institute has climate models for the period up until 2100 that cover all of Greenland. The model results predict a future climate with an annual summer mean temperature that is 2-3 degrees higher than today.
All things being equal, this translates into an increase in permafrost thawing in the order of 10-30 cm over the next 70 years. The reason for not stating a more precise figure is that the increase in thawing depends on soil type, in particular the water content. The maximum thawing depth is expected in the dry soil types. |
The Eastern Black Sea region was home to the well-developed bronze age culture, known as the Colchian culture. In at least some parts of Colchis, the process of urbanization seems to have been well advanced by the end of the second millennium B.C, centuries before Greek settlement. The Colchian Late Bronze Age (15th to 8th Centurys B.C.) saw the development of significant skill in the smelting and casting of metals, that began long before this skill was mastered in Europe. Sophisticated farming implements were made, and the fertile, well-watered lowlands with their mild climate, promoted the growth of progressive agricultural techniques.
According to Greek mythology, Colchis was a fabulously wealthy land situated on the mysterious periphery of the heroic world. Here in the sacred grove of the war god Ares, King Aeëtes hung the Golden Fleece until it was seized by Jason and the Argonauts. Colchis was also the land where the mythological Prometheus was punished by being chained to a mountain while an eagle ate at his liver, for revealing to humanity the secret of fire. The Amazons also were said to be from Colchis. The main mythical characters from Colchis are Aeëtes, Medea, Absyrtus, Chalciope, Circe, Eidyia, Pasiphaë.
In about 730 B.C, Colchis was overrun by the White Kurgan tribes called Cimmerians and Scythians. But they appear to have done little permanent damage.
In about 600 B.C, the advanced economy of Colchis soon attracted the attention of the Milesian (White) Greeks in Anatolia (Turkey), who colonized the Colchian coast and established trading posts at Phasis, Gyenos, and Sukhumi.
In about 580 B.C, the kingdom came under the control of (probably by the dating); King Astyages of the Median Empire. Which would soon become part of the first Persian Empire under Cyrus II, the Great. (The Sassanian was the second Persian Empire).
Herodotus in Book 3 says: The tribes living in southern Colchis (the Tibareni, Mossynoeci, Macrones, Moschoi, and Marres) were incorporated in the 19th Satrapy of the Persian King Darius; while the northern tribes submitted “voluntarily” and had to send to the Persian court 100 girls and 100 boys in every 5 years.
The Tibareni - Called Tubal by Josephus Flavius (see below) - He identifies them with the (Eastern) Iberians and Cappadocians.
The Macrones (Makrones) were an original Colchian tribe.
The Moschoi - Josephus Flavius identified the Moschoi with the Biblical Meshech. Meshech is named with Tubal (and Rosh, in certain translations) as principalities of "Gog, prince of Magog" in Ezekiel 38:2 and 39:1, and is considered a Japhetite tribe, identified by Flavius Josephus with the Cappadocian Moschoi (Mushki, also associated with Phrygians or Bryges) and their capital Mazaca. Another Meshech is named as a son of Aram in 1 Chronicles 1:17 (corresponding to the form Mash in Genesis 10). In Hippolytus of Rome's chronicle (234 AD), the "Illyrians" were identified as Meshech's offspring. In addition, Georgians have traditions that they, and other Caucasus people including Armenians, share descent from Meshech.
The Mossynoeci - (Greek word Mossynoikoi "dwellers in wooden towers"). The Greeks of the Black Sea area applied it to the peoples of Pontus, on the northern Anatolian coast.
Herodotus on Colchis:
[2.104] There can be no doubt that the Colchians are an Egyptian race. Before I heard any mention of the fact from others, I had remarked it myself. After the thought had struck me, I made inquiries on the subject both in Colchis and in Egypt, and I found that the Colchians had a more distinct recollection of the Egyptians, than the Egyptians had of them. Still the Egyptians said that they believed the Colchians to be descended from the army of Sesostris. My own conjectures were founded, first, on the fact that they are black-skinned and have woolly hair, which certainly amounts to but little, since several other nations are so too; but further and more especially, on the circumstance that the Colchians, the Egyptians, and the Ethiopians (Nubians), are the only nations who have practised circumcision from the earliest times.
An abject example of the lying degeneracy of Whites.
This is in the British museum.
|Plate 7: Jason arriving in Colchis and embracing King Aeëtes; on the right, Hercules standing beside Jason, and beyond the Argonauts disembarking; in ornate border, with below a cartouche printed from a separate plate. Print made by René Boyvin After Léonard Thiry 1563 . It is best to assume that everything the White man says is a lie, then work back from there.|
Iberia also known as Iveria was a name given by the ancient Greeks and Romans to the ancient Georgian kingdom of Kartli (4th century BC-5th century AD) corresponding roughly to the eastern and southern parts of the present day Georgia.
The term “Caucasian Iberia” (or Eastern Iberia) is used to distinguish it from the Iberian Peninsula, where the present day states of Spain, Andorra and Portugal are located. The Caucasian Iberians provided a basis for later Georgian statehood and formed a core of the present day Georgian people (or Kartvelians).
The area was inhabited in earliest times by several related tribes, collectively called Iberians (the Eastern Iberians) by ancient authors. Locals called their country Kartli after a mythic chief, Kartlos.
The Moschi mentioned by various classic historians, and their possible descendants, the Saspers (who were mentioned by Herodotus), may have played a crucial role in the consolidation of the tribes inhabiting the area. The Moschi had moved slowly to the northeast forming settlements as they migrated. The chief town of these was Mtskheta, the future capital of the Iberian kingdom. The Mtskheta tribe was later ruled by a chief locally known as Mamasakhlisi (“the father of the household” in Georgian).
The medieval Georgian source Moktsevai Kartlisai (“Conversion of Kartli”) speak also about Azo and his people, who came from Arian-Kartli - the initial home of the proto-Iberians, which had been under Achaemenid rule until the fall of the Persian Empire - to settle on the site where Mtskheta was to be founded. Another Georgian chronicle Kartlis Tskhovreba (“History of Kartli”) claims Azo to be an officer of Alexander’s armies, who massacred a local ruling family and conquered the area, until being defeated at the end of the 4th century, B.C, by Prince Pharnavaz, who was a local chief at that time.
Pharnavaz I and His Descendants
Pharnavaz, victorious in power struggle, became the first King of Iberia (ca. 302 - 237 BC). Driving back an invasion, he subjugated the neighbouring areas, including significant part of the western Georgian state of Colchis (locally known as Egrisi), and seems to have secured recognition of the newly founded state by the Seleucids of Syria. Pharnavaz then focused on social projects, including the construction of the citadel in the capital, the Armaztsikhe, and erection of an idol of a god named Armazi. He also reformed the Georgian written language, and created a new system of administration subdividing the country into several counties called saeristavos. His successors managed to gain control over the mountainous passes of the Caucasus Range with Daryal (also known as the Iberian Gates) being the most important of them. The period following this time of prosperity was marked with incessant warfare though. Iberia was forced to defend itself against numerous invasions. As a result, the country lost some of its southern provinces to Armenia, and the Colchian lands seceded to form separate princedoms (sceptuchoi). At the end of the 2nd century BC, the Pharnavazid king Farnadjom was dethroned by his own subjects and the crown given to an Armenian prince Arshak who ascended the Iberian throne in 93 BC, establishing the Arshakid dynasty.
This close association with Armenia brought upon the country an invasion (65 BC) by the Roman general Pompey, who was then at war with both Mithradates VI of Pontus, and Tigran II of Armenia. However, Rome failed to establish its permanent power over Iberia. Nineteen years later, the Romans again marched into Iberia (36 BC) forcing King Pharnavaz II to join their campaign against Caucasian Albania.
Between the early 2nd century, B.C. and the late 2nd century A.D., the Kingdom of Colchis together with the neighbor countries, become an arena of long and devastating conflicts between major local powers Rome, Kingdom of Armenia and the short-lived Kingdom of Pontus. As a result of the brilliant Roman campaigns of generals Pompey and Lucullus, the Kingdom of Pontus was completely destroyed by the Romans and all its territory including Colchis, were incorporated into Roman Empire as her provinces.
The former Kingdom of Colchis was re-organized by the Romans into the province of Lazicum ruled by Roman legati. During Byzantine times, the word Colchi gave way to the term Laz. The Roman period was marked by further Hellenization of the region in terms of language, economy and culture. For example, since the early 3rd century, Greco-Latin Philosophical Academy of Phasis (present-day Poti) was quite famous all over the Roman Empire. In the early 3rd century, newly established Roman Lazicum was given certain degree of autonomy which by the end of the century developed into full the independence and formation of a new Kingdom of Lazica (covering the modern day regions of Mingrelia, Adjaria, Guria and Abkhazia) on the basis of smaller principalities of Zans, Svans, Apsyls and Sanyghs. Kingdom of Lazica survived more than 250 years until in 562 AD it was absorbed by the Byzantine Empire. In the middle of the 4th century, Lazica adopted Christianity as her official religion. That event was preceded by the arrival of St. Simon the Canaanite (or Kananaios in Greek) who was preaching all over Lazica and met his death in Suaniri (Western Lazica). According to Moses of Chorene, the enemies of Christianity cut him in two halves with a saw.
The re-incorporation of Lazica with the Kingdom of Aphkhazeti into Byzantine Empire in 562 AD was followed by 150 years of relative stability that ceased in the early 7th century when the Arabs appeared in the area as a new regional power. Today, the entire area is part of the Republic of Turkey. But its history dates back to when the first South Caucasian state in the west was the Kingdom of Colchis which covered modern western Georgia and modern Turkish provinces of Trabzon and Rize.
While Colchis was turned into a Roman province, Iberia accepted Roman Imperial protection. A stone inscription discovered at Mtskheta speaks of the first-century ruler Mihdrat I (A.D. 58-106) as "the friend of the Caesars" and “the King of Roman-loving Iberians." It was at that period when Emperor Vespasian fortified the ancient Mtskheta site of Arzami for the Iberian kings in 75 A.D.
The next two centuries saw a continuation of Roman influence over the area, but by the reign of King Pharsman II (116 – 132) Iberia had regained some of its former power. Relations between the Roman Emperor Hadrian and Pharsman II were strained, though Hadrian is said to have sought to appease Pharsman. However, it was only under Hadrian's successor Antoninus Pius that relations improved to the extent that Pharsman was said to have even visited Rome, where Dio Cassius reported that a statue was erected in his honor and that rights to sacrifice were granted to him. The period brought a major change to the political status of Iberia with Rome recognizing the kingdom as an ally rather than subject state as its former status was. That political situation remained the same for quite a while, even during the period of the Empire's conflict with the Parthians.
Decisive for the future history of Iberia was the foundation of the Sassanian Empire in 224. By replacing the weak Parthian realm with a strong, centralized state, it changed the political orientation of Iberia drifting it away from Rome. During the reign of Shapur I (241-272) Iberia became a tributary of the Sassanian state. Relations between the two countries seem to have been friendly at first as Iberia cooperated in Persian campaigns against Rome, and the Iberian king Amazasp III (260-265) was listed as a high dignitary of the Sassanian realm, not a vassal who had been subdued by force of arms. But the aggressive tendencies of the Sassanians were evident in their propagation of Zoroastrianism, which was probably established in Iberia between the 260s and 290s A.D. However, in accordance with the Peace Teaty of Nisibis (298) Rome was acknowledged the dominant power over the whole area, but recognized Mirian III, the first of the Chosroid dynasty, as the King of Iberia. Roman dominance proved crucial, since King Mirian II and leading nobles converted to Christianity around 317 A.D. The event is related with the mission of a Cappadocian woman, Saint Nino, who in the year of 303, started preaching Christianity in Iberia.
The religion became a strong tie between Iberia (since then also known as Kartli) and Rome / Byzantine Empire and had a large-scale impact on the state's culture and society. However, after the emperor Julian was slain during his failed campaign in Persia in 363, Rome ceded control of Iberia (Kartli) to Persia, and King Varaz-Bakur I (Asphagur) (363-365) became a Persian vassal, an outcome confirmed by the Peace of Acilisene in 387. Although a later ruler of Iberia/Kartli, Pharsman IV (406-409), preserved his country's autonomy and ceased to pay tribute to Persia, Persian influence still prevailed in the region, and Sassanian kings soon began to appoint their Viceroys (pitiaxae/bidaxae) to keep watch on Iberia/Kartli. The Persians eventually made Viceroyal office hereditary in the ruling house of Lower Kartli, thus inaugurating the Kartli pitiaxate bringing under their control quite an extensive territory. Although it remained a part of the kingdom of Kartli, its viceroys turned their domain into a center of Persian influence. Sassanian rulers put the Christianity of the Georgians to a severe test. They promoted the teachings of Zoroaster, and by the middle of the 5th century, Zoroastrianism became a second official religion in eastern Georgia alongside Christianity. However, efforts to convert the common Georgian people were generally unsuccessful.
The early reign of the Iberian king Vakhtang I also known as Gorgasali (447-502) was marked by relative revival of the kingdom. Formally vassal of the Persians, he secured the northern borders by subjugating the Caucasian mountaineers, and brought the adjacent western and southern Georgian lands under his control. He established an Autocephalic Patriarchate at Mtskheta, and made Tbilisi his capital. In 482, Vakhtang Gorgasali led a general uprising against Sassanian Persia. A desperate war for independence lasted for twenty years, but the kingdom failed to gain active Byzantine support and was finally defeated in 502 when King Vakhtang was slain in battle.
FALL OF THE KINGDOM
The continuing rivalry between Byzantium and Persia for supremacy in the Caucasus, and an abortive insurrection of the Iberians under Gurgen that followed (523), had tragic consequences for the country. Thereafter, the kings of Iberia had nominal power only while the country was effectively ruled by the Persians. In 580, Hormizd IV (578-590) abolished the monarchy after the death of King Bakur III, and Iberia became a Persian province ruled by a marzpan (governor). In the late 6th century, Iberian nobles urged Byzantine Emperor Maurice to recreate the Kingdom of Iberia, and the independence was temporarily restored in 582. However in 591, Byzantium and Persia agreed to partition Iberia with Tbilisi being assigned to Persian while Mtskheta remained under Byzantine control.
At the beginning of the 7th century, the truce between Byzantium and Persia collapsed. The Iberian Prince Stephanoz I (ca. 590-627), decided in 607 to join forces with Persia in order to reunite all the provincess of Iberia under one crown, a goal he seemed to have accomplished. But the offensive of Emperor Heraclius' armies in 627 and 628, resulted in the defeat of both Iberians and Persians and secured Byzantine dominance in the South Caucasus until the beginning of the Arab invasion.
THE ARAB INVASION
The Arab armies reached Iberia about 645 and forced its Crown Prince Stephanoz II ca 637-650), to abandon his allegiance to Byzantium and recognize the Caliph as his suzerain. Iberia thus became a tributary state and an Arab Emir was appointed to Tbilisi around the year of 653.
At the beginning of the 9th century, Ashot I (813-830) of the new Bagrationi dynasty, took advantage of the weakening of the Arab rule in the area and expanded his domain in the southwestern province of Speri to establish himself as hereditary ruler (Curopalates) of the whole of Iberia. His successor, Adarnase II of Tao, formally vassal of Byzantium, was crowned as the “king of Iberians” in 888. His descendant Bagrat III (975-1014), brought several smaller states together under one crown to form the first united Georgian state.
EASTERN AND WESTERN IBERIAS
The similarity of the name with the old inhabitants of the Iberian peninsula, the 'Western' Iberians, has led to an idea of ethno-genetic kinship between them and the people of Caucasian Iberia (called the 'Eastern' Iberians).
It has been advocated by various ancient and medieval authors although they differed in approach to the problem of the initial place of their origin. The theory seems to have been popular in medieval Georgia. The prominent Georgian religious writer Giorgi Mthatzmindeli (George of Mt Athos) (1009-1065) writes about the wish of certain Georgian nobles to travel to the Iberian peninsula and visit the local “Georgians of the West”, as he called them.
Albania, Parthian: Ardhan, Middle Persian: Arran; usually referred to as Caucasian Albania for disambiguation with the modern state of Albania; the native name for the country is unknown. It is a name for the historical region of the eastern Caucasus, that existed on the territory of present-day republic of Azerbaijan (where both of its capitals were located) and partially southern Dagestan.
The Parthian name was Ardhan ( Middle Persian: Arran). The Arabic was ar-Rān. The name of the country in the language of the native population, the Caucasian Albanians, is not known.
Aghuank is the Armenian name for Caucasian Albania. Armenian authors mention that the name derived from the word "Aghu" meaning amiable in Armenian. The term Aghuank is polysemous and is also used in Armenian sources to denote the region between the Kur and Araxes rivers as part of Armenia. In the latter case it is sometimes used in the form "Armenian Aghuank" or "Hay-Aghuank".
The Armenian historian of the region, Movses Kaghankatvatsi, who left the only more or less complete historical account, also explains the name Aghvank as a derivation from the word Aghu (Armenian for sweet, soft, tender), which, he said, was the nickname of Caucasian Albania's first governor Arran and referred to his lenient personality. Moses of Kalankatuyk and other ancient sources explain Arran or Arhan as the name of the legendary founder of Caucasian Albania (Aghvan) or even as the Iranic tribe known as Alans (Alani), who in some versions was son of Noah's son Yafet (Japheth). James Darmesteter, translator of the Avesta, compared Arran with Airyana Vaego which he also considered to have been in the Araxes-Ararat region, although modern theories tend to place this in the east of Iran.
Originally, the Caucasian Albanians apparently spoke Lezgic languages close to those found in modern Daghestan. After the Caucasian Albanians were Christianized in the 4th century, the western parts of the population were gradually assimilated by the ancestors of modern Armenians, and the eastern parts of Caucasian Albania were Islamized and absorbed by Iranian and subsequently Turkic peoples(modern Azerbaijanis). Small remnants of this group continue to exist independently, and are known as the Udi people.
The pre-Islamic population of Caucasian Albania might have played a role in the ethnogenesis of a number of modern ethnicities, including the Azerbaijanis, the Armenians of the Nagorno-Karabakh, the Georgians of Kakhetia, the Laks, the Lezgins and the Tsakhurs of Daghestan.
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Standards in Economics
Below are the National Standards in Economics that most closely relate to the following interactive tool.
- Students will understand that: Institutions evolve and are created to help individuals and groups accomplish their goals. Banks, labor unions, markets, corporations, legal systems, and not-for-profit organizations are examples of important institutions. A different kind of institution, clearly defined and enforced property rights, is essential to a market economy.
- Students will be able to use this knowledge to: Describe the roles of various economic institutions and explain the importance of property rights in a market economy.
Name: Competition and Market Structure
- Students will understand that: Competition among sellers usually lowers costs and prices, and encourages producers to produce what consumers are willing and able to buy. Competition among buyers increases prices and allocates goods and services to those people who are willing and able to pay the most for them.
- Students will be able to use this knowledge to: Explain how changes in the level of competition in different markets can affect price and output levels. |
Confined Space Lighting for Hazardous Locations |
Confined spaces represent some of the most dangerous work places in commercial industries. Because of their enclosed nature, confined spaces are poorly ventilated and allow volatile gases, fumes, vapors and particulates to accumulate and increase in atmospheric density to potentially explosive levels. Confined spaces represent a hazardous work area and are loosely defined by a few general characteristics.
- The area is large enough to permit entry and the performance or work;
- Has limited openings for entry and exit; and
- Is not intended for continuous worker presence within the space.
Examples of confined spaces are the chemical storage tanks used by power plants and industrial operations, silos used in agriculture, ship tanks used for the transport of chemicals, petroleum and other volatile materials and railroad car tanks. Each of these is an example of confined spaces that represent hazardous conditions for workers who must enter them to perform jobs such as servicing and cleaning.
Although there are many procedures and programs in place to mitigate the dangers of working in confined spaces, accidents still occur and it is critical that workers entering confined spaces be aware of the hazards at all times. Most states have implemented programs and regulations intended to create and enforce standards governing the performance of work in the hazardous conditions that confined spaces represent. These regulations have been largely successful in reducing the number of incidents resulting in injuries, damages and deaths in hazardous work areas. These programs and regulations center on educating the workers, providing rules for the types of equipment to be used and how work in confined spaces is to be performed. In order to ensure the maximum safety of all workers, these regulations must always be observed and adhered to. This can be a problem as these hazardous areas often vary in the level of danger they present.
Confined spaces can often appear non hazardous, but this appearance is deceiving. Workers may have entered and exited, performed work and tested for the presence of volatile compounds previously and found conditions acceptable, yet conditions within these spaces are highly dynamic and as a result can change quickly and without notice. Because of this, any time workers are about to enter a potentially hazardous confined space, testing for the presence of volatile compounds and their levels should precede entry. The proper gear must always be used and the procedures for removing the presence of volatile compounds from the work space must always be implemented if there is any doubt.
Although due diligence and procedure can greatly reduce the hazards of working in a confined space, there are no guarantees that they will be one hundred percent effective in protecting the worker. As a result, further measures must also be taken to ensure that the risks from explosions and fire are reduced as much as possible. These measures include ensuring that workers have the properly rated equipment for the jobs at hand and that this equipment is properly used and maintained. According to studies and reports compiled by OSHA, most workplace accidents are a result of human errors and the improper use of equipment. For example, something as simple as a naked light bulb in a non explosion proof housing can instantly ignite volatile vapors or gases if the light is dropped or the bulb broken and result in a serious explosion or fire. Fire and explosions are two of the biggest concerns with working in confined spaces due to the unpredictable nature of volatile gases or vapors within an enclosed area. For work that is to be performed in a confined area where gases or vapors may be present, any equipment used by the workers must be explosion proof and rated for use in that particular environment.
Lighting the interior of confined area workspaces is almost always a necessary requirement and any lighting equipment used must be rated explosion proof by a recognized authority such as Underwriters Laboratories. Portable lighting, personal work lights and commercial tank lights all must meet with OSHA guidelines for use in hazardous locations when used in confined work spaces where volatile compounds may be present. Lamps like Larson Electronics’s Explosion Proof Light - Class 1 & II Div 1 & 2 - 70 Watt Metal Halide are specifically designed to meet the requirements set forth by regulatory agencies for explosion proof lighting and are appropriate for use in locations like confined spaces where volatile compounds may be present.
Lights like these reduce the chances of accidentally igniting volatile compounds by preventing heated gases from escaping the lamps housing until they are cooled enough to be incapable of causing ignition and are constructed of materials that resist producing sparks when they are dropped or make contact with other metallic surfaces. These lamps allow workers to safely and powerfully illuminate the interior of confined spaces while complying with the necessary regulations governing such applications. Since it is nearly impossible to guarantee that a confined space will remain entirely free of volatile compounds while work is being performed, explosion proof lights add further protection by removing possible sources of ignition. Since an atmosphere requires three basic ingredients to become flammable; fuel, oxygen, ignition source; explosion proof lights remove one of the necessary components. Although two may be present, without the third, ignition cannot take place.
Explosion proof lighting equipment must be operated only within its rated classes and divisions. A Class 2 Division 2 lamp will not be suitable for use in a location that requires a Class1 explosion proof lamp and will fail to meet OSHA requirements. Although equipment may be rated explosion proof and properly rated for a given application, it must also be used and maintained properly. Lighting equipment should always be inspected prior to use for damaged cords, loose housings, worn plugs, cracked or loose lenses and exposed wiring. Plugs that are not rated explosion proof must be connected to a power source outside the hazardous workspace.
There are many factors that affect how hazardous a confined space may be. Atmospheric conditions are only one factor, yet represent one of the most important factors that must be evaluated before workers enter. Conditions can change quickly in hazardous confined workspaces and the appropriate procedures and equipment must always be followed and used to avoid potential problems should conditions change. Explosion proof lighting adds an extra degree of protection that procedure and training alone cannot provide and should always be used in any situation that may expose workers to a volatile environment. |
Artificial Wetlands for Wastewater Treatment
By Dr. Isobel Heathcote
What is the ideal sewage treatment system? It would probably produce high-quality effluent (discharge) at a modest cost, be aesthetically pleasing, and would not create secondary environmental impacts. Yet the reality is that the vast majority of wastewater treatment systems developed over the past 25 years discharge highly toxic effluents, are ugly and/or have a strong odor, and create secondary problems in air quality or sludge disposal. These plants may also consume large quantities of energy in processing, sludge-drying, incineration, and other activities. It is becoming increasingly clear that bigger is not necessarily better in terms of wastewater treatment efficiency or environmental impact.
A conventional sewage treatment plant typically discharges effluents containing relatively low amounts of biochemical oxygen demand (BOD) and suspended solids (SS)—often around 30 mg/L of each. But for every 10,000 people, a secondary plant discharges with the treated wastewater over 100 kg/day of microbial dry solids, an equal amount of oxygen-demanding substances, and enough nutrients to provide fertilizer to grow crops on over 300 hectares. Where chlorination is practiced, a substantial amount of toxic chlorinated organic compounds are also discharged. In addition, two thirds of the dry matter received by the plant is only converted in form and discharged as sludge, on average about 12 cubic meters of wet residue for every 10,000 people. Because most of these facilities practice intensive aeration, volatile organics—including some known carcinogens—are stripped during the treatment process and discharged into the local environment. In many cases, significant quantities (kg/day) of these materials are discharged into the atmosphere. And these conventional technologies are not cheap: They typically cost each individual served about 1% of his or her annual income.
Some engineers and scientists are beginning to challenge the notion that sewage treatment facilities must be large, costly, and unsightly. They believe that natural technologies, such as constructed wetlands, could offer better treatment at lower costs, with better aesthetics and less environmental impact, than traditional methods. Some authors have even used the term sewage treatment park instead of sewage treatment plant.
These natural (sometimes called “alternative”) wastewater treatment technologies are attracting considerable attention across Canada and elsewhere in the world. A variety of proprietary systems are now available on the market, and many municipalities, industries, and farms have begun testing constructed wetlands as a treatment alternative or an adjunct to conventional treatment. Constructed wetlands are now in use in the treatment of acid mine drainage, barn wastes, feedlot runoff in agricultural operations, urban stormwater runoff, various industrial wastewater treatment applications, and in the secondary and tertiary treatment of municipal sewage. Private applications of this technology are also on the rise, replacing traditional septic systems, especially in areas where those conventional approaches are not feasible or where dense development limits their treatment efficiency. A number of community systems have been developed for groups of 10 to 200 homes, and some authors believe that this community approach to sewage treatment is likely to be an important trend in the future, reducing dependence on large, costly, centralized sewage treatment facilities.
There are various kinds of constructed wetlands. Some are housed in a greenhouse enclosure, where they can provide aesthetic and indoor air quality benefits as well as effluent treatment. Examples of these systems are the solar aquatics installations at the head office of The Body Shop in Toronto, Ontario, the Boyne River Outdoor Education Centre just outside Toronto, and facilities at Bear River and Beaverbank Villa, Nova Scotia. (The term solar aquatics was coined by John Todd, an innovator in this field and the designer of the first installation of this type.) Some of these facilities have generated such public interest that they have become tourist attractions in their own right.
Other wetlands are modeled on natural systems and are located outdoors, without protection from the elements even in the coldest times of winter. Among these are the Village of Alfred (Ontario) constructed wetland system, which treats 15% of the municipal sewage effluents in that town, and the Listowel Marsh, in west-central Ontario, which was the site of a long-term study of constructed wetland performance through the 1980s. These systems are usually planted with a variety of species (although single-species reed beds are also sometimes used), with certain plants, such as cattails, used in the initial stages and a mixture of other water-tolerant species used to polish the effluent in its final stages. Sometimes, additions to the wetland sediments (for instance, crushed recycled iron) are used to improve the removal of phosphorus or other target constituents.
In general, constructed wetlands have been proven to perform well and often inexpensively relative to conventional treatment systems. Depending on the system and its configuration, problems may arise with insect or mammal pests. Invasive muskrats may, for instance, chew off most of the emergent cattail growth and reduce treatment efficiency in a cattail marsh. In some multistage systems, insect infestations have caused certain stages of the process to fail temporarily. But most systems have been designed with enough retention time that effluents can be held until an adequate discharge quality is achieved, so temporary upsets do not create serious problems with the process.
Constructed wetlands are very popular with the public, but regulatory agencies have been slower to support them, in part because of concerns that their performance may be less effective or less reliable than tried-and-true technologies. The public, and many engineers and scientists, would respond by saying that conventional technologies are inadequate in other ways, and there is a clear need for alternative technologies for wastewater treatment.
One of the most important advantages of constructed wetlands is their aesthetic appeal. Some researchers believe that the sewage treatment plant of the future could actually do double duty as a wastewater treatment facility and a recreational facility. Certainly, constructed wetlands, whether greenhouse-enclosed or out-of-doors, are an attractive alternative to the monolithic structures of most modern-day sewage treatment plants.
Constructed wetlands offer the potential to create habitat for bird and mammal populations, and thus to improve the ecological integrity of a wastewater treatment site. In an urban area, wildlife habitat can be scarce in any case, so the creation of additional habitat is often highly valued. When this creation occurs in conjunction with a socially valuable function like sewage treatment, local residents may particularly welcome the facility.
Evidence from a number of experimental sites suggests that the maintenance and labor costs associated with constructed wetlands are significantly lower than those for conventional treatment facilities designed to treat the same volume of wastewater. In other words, the costs of treating the sewage flows for 10,000 people are potentially lower, or much lower, with a constructed wetland system than they would be for a conventional treatment system, while effluent quality from those systems is as good or better than that from conventional systems. It should be noted, however, that treatment costs can vary widely depending on the nature of the raw sewage stream (for instance, whether it contains a high proportion of inorganic and trace industrial pollutants from industrial discharges), on climate, and on other local factors.
Phosphorus removal is notoriously poor in many constructed wetland systems. The reasons for this are not entirely clear, but may be related to reduced oxygenation of the root zone in slow-moving waters. Although constructed wetlands may be able to remove BOD, suspended solids, and nitrogen compounds with reasonable effectiveness, they may not perform well in terms of phosphorus removal. Where phosphorus enrichment is a concern (for instance, because of the potential for eutrophication), constructed wetlands may cause problems rather than solve them.
to Climate and Disease
A conventional wastewater treatment system is well protected from the elements and from disease and predators, but a constructed wetland is vulnerable to all three. Although even a conventional plant experiences an occasional process upset—for instance from unexpectedly high loads of certain pollutants in the raw sewage—generally, a conventional plant is well-buffered from its environment. By definition, a constructed wetland is part of its environment, and is subject to the same forces. In cold climates, as would be the case in most of Canada, climatic variations in particular may affect the performance of a natural treatment system. In the spring and during summer thunderstorms, excessive rainfall can flood a wetland, decreasing its treatment effectiveness. Insects and other predators can reduce the populations of key wetland species, thus impairing the treatment function. Simple upsets of temperature, pH, or other factors can affect the health and removal efficiency of wetland plants. These factors create a potential for variability in effluent quality that is unacceptable in a public utility or a private treatment facility subject to legally binding standards for discharge.
Although a conventional sewage treatment plant can have a life expectancy of many decades if it is adequately maintained and upgraded, the life expectancy of a constructed wetland system is likely to be much shorter. For one thing, wetlands tend to accumulate suspended solids, so they will fill up with time, gradually reducing their volume and thus their treatment capacity—and their effectiveness. Because of the relative newness of alternative technologies, long-term data for wetland performance is not yet available. Estimates suggest that wetlands may be limited to 15 to 20 years of life, compared to the 25- to 50-year life span possible with conventional facilities.
4. Creation of Toxic Wetlands
As wetlands accumulate sediments, they also accumulate the many pollutants that have a natural affinity for solids. These pollutants include some forms of phosphorus, many heavy metals, and some trace organic pollutants. When the wetland is retired at the end of its useful life, it is not an inert or innocuous component of the environment but rather a hazardous waste disposal site. Concentrations of hazardous materials in wetland sediments may be too high to permit the use of the site for other purposes, such as recreation. The treatment or removal of those contaminated sediments may therefore add significantly to the costs of building and operating a constructed wetland.
Regardless of how it is processed, treated effluent must comply with applicable discharge standards. In most of Canada, provincial standards would apply, either specific standards for a given industry or discharge point, or general prohibitions against pollution. The Canadian Federal Fisheries Act contains prohibitions on discharges that adversely affect the quality of fish habitat, and the Canadian Environmental Protection Act contains general prohibitions on environmental degradation. In most provinces, approval must be obtained for any effluent discharge before a new treatment works operation is allowed to begin. (This, in fact, has been the point at which some constructed wetlands have been refused permission to operate.) Application procedures and expectations are generally geared to more conventional technologies, so it may be difficult to persuade regulators that an innovative technology will be as good as, or better than, conventional treatment approaches. Nevertheless, the new technology will not be allowed to operate until such official permission is given. Local standards may apply for the discharge of stormwater treated in a constructed wetland, or for industrial or other effluents treated in this way and destined for discharge to municipal sewer systems. Municipal zoning restrictions may limit where new constructed wetland facilities may be built.
The principal text resources for this topic are found in Chapters 7 and 17.
· Chapter 7 (Water: Hydrologic Cycle and Human Use), Section 7.2 (“The Hydrologic Cycle,” pages 181–189), and Section 9.3 (“Water: A Resource to Manage, a Threat to Control,” pages 189–195), discuss the hydrologic cycle and how human activities affect it.
· Chapter 17 (Water Pollution and Its Prevention) provides an overview of the many factors that influence water quality, including sewage pollution. Section 17.1 (“Water Pollution,” pages 464–472) covers the basic components of sewage, including nutrients, organic wastes, microorganisms, and chemical pollutants. Section 17.2 (“Eutrophication,” pages 472–479), describes the impacts of excessive nutrients on the aquatic environment. Section 17.3 (“Sewage Management and Treatment,” pages 479–486), specifically addresses the problem of managing human wastes, and discusses both conventional and alternative treatment systems. Section 17.4 (“Public Policy,” pages 486–487), describes the U.S. legislative framework regulating water quality and sewage pollution.
This page is maintained by a researcher at Texas A&M University and contains information about recent research on constructed wetlands for the treatment of livestock wastes.
This is a news article describing the solar aquatics installation at Bear River, Nova Scotia, Canada.
This brief site from North Carolina State University reports on the results of recent research on the use of constructed wetlands for the removal of nutrients and solids from swine-lagoon effluent.
This site describes a solar aquatics installation in the town of Weston, Massachusetts, just outside Boston, and discusses some of the pros and cons of this innovative technology.
This PDF fact sheet gives an overview of the pilot solar aquatics facility at the Ontario Science Centre (Toronto). Although the facility is no longer functional, this site provides detailed information about how it worked and how it looked.
This article discusses the village of Alfred, Ontario, constructed wetland facility, which treats 15% of Alfred’s municipal sewage stream.
This site describes a citizen-based project to develop alternative solutions to wastewater treatment challenges in Hornby Island, British Columbia.
EDM Consultants maintains this page, describing their solar aquatics projects at Bear River and Beaverbank Villa, Nova Scotia.
Gale, P. M., K. R. Reddy, and D. Graetz, “Phosphorus Retention by Wetland Soils Used for Treated Wastewater Disposal.” Journal of Environmental Quality 23 (1994): 370–377.
Griggs, J. “Constructed Wetlands—A Low-Cost Reliable Alternative for Waste Water Treatment.” J. Soil & Water Cons 21, no. 4 (1988): 13.
Kadlec, R. H., and H. Alvord, Jr., ed. Mechanisms of Water Quality Improvement in Wetland Treatment Systems. In Wetlands: Concerns and Successes. Bethesda, MD: American Water Resources Association, 1989.
Kadlec, R. H., and R. L. Knight, Treatment Wetlands. New York: CRC Press and Lewis Publishers, 1996.
Pullin, B. P., and D. A. Hammer. “Aquatic Plants Improve Wastewater Treatment.” Water Environment & Technology 3, no. 3 (1991): 36–40.
Reed, S. C. “Nationwide Inventory: Constructed Wetlands for Wastewater Treatment.” Biocycle 32, no. 1 (1991): 44–49.
Teal, J., and S. B. Peterson. “A Solar Aquatic System Septage Treatment Plant.” Environmental Science and Technology 27, no. 1 (1993).
Water Pollution Control Federation. Natural Systems for Wastewater Treatment: Manual of Practice FD-16. Alexandria, VA: Water Pollution Control Federation. 1990. |
Prions are shape-shifting proteins that act like germs, infecting healthy tissue and causing havoc in the body. Prions pass on, or infect, by converting normally folded molecules of the same protein into abnormally structured clumps called amyloid. The changed structure is extremely stable and accumulates in infected tissue, causing tissue damage and cell death, often leading to devastating disorders in the brain, such as ‘mad cow’ disease. This extreme stability and the ability to shift into multiple different shapes or ‘strains’ make prions exceptionally difficult drug targets.
Yeast prions. Credit: James Shorter, PhD.
In a paper published in Nature Chemical Biology, researchers found that yeast prions were able to evade a small-molecule inhibitor by shifting into a novel drug-resistant shape that does not usually appear. However, by combining two small molecules, prions could no longer escape and were eradicated.
“We were very surprised to find that the prion could change into a brand new shape to evade what we had anticipated to be a very potent small molecule inhibitor. However, by combining two different inhibitors we were able to hit multiple prion strains.” says senior author James Shorter, PhD, assistant professor of Biochemistry and Biophysics at the Perelman School of Medicine.
These findings provide proof-of-principle that small molecule combinations can counter strains of amyloid, which likely plays an important role in other fatal neurodegenerative disorders, including Alzheimer’s and Huntington’s disease.
“When used together their effect was synergistic, because the two small molecules work in different ways to break up the prions. We suspect that small molecule cocktails that safely eradicate complete strain repertoires can be found for various neurodegenerative disorders.” says Shorter.
This research was done in collaboration with Martin Duennwald at the Boston Biomedical Research Institute. |
What is Dyspraxia?
Dyspraxia is a condition that has an impact on the early development of motor skills, and manifests in delayed language development, poor articulation, and poor listening skills. Despite these difficulties, adults and children with dyspraxia have normal or even above average intellectual abilities.
In children, the symptoms of dyspraxia include learning difficulties, poor handwriting, difficulties with fine motor skills, eating, dressing, and toileting. Children with dyspraxia are often described as clumsy or accident prone. They can perform in certain areas of sport, but struggle with the ability to learn, plan and carry out skilled or seldom-used tasks requiring motor skills.
When writing children with dyspraxia require an immense effort to achieve and keep up with their peers. In class they are often described as inconsistent, one day being able to carry out a certain task, but the following day showing confusion and an inability to perform the same task.
For older children with dyspraxia it is often counter-productive to persist with handwriting training programmes. The use of modern technology has been found to be an effective tool to support these children with their requirements and progress at school.
Adults with dyspraxia describe difficulties in planning a sequence of actions and/or accurately retrieving or storing sensory information. This often manifests with high levels of disorganization, a poor ability to multi-task, the need to repeat routines obsessively, lack of perseverance, and a general feeling of fatigue in the absence of other medical conditions.
Pro Ed understand the importance of identifying dyspraxia early in order to instigate specific and relevant intervention programmes, e.g. occupational therapy, which can address symptoms, such as fatigue, poor posture, messy handwriting, frustration, loss of focus, low self-esteem and lack of confidence. |
Teachers' Pets: Tips for keeping classroom animals and new ways to engage your students
Click to enlarge:
Healthy pet tortoise
Here is a picture showing the large enclosure and special lighting requirements to keep a tortoise kept indoors healthy.
Image courtesy of Beth Girard.
View of tortoise's enclosure from above
Another view of the tortoise enclosure.
Image courtesy of Beth Girard.
Outdoor learning can be a great way to grasp students' attention; even the most urban wetlands are teaming with life. Partnering with a local nature center, park, or other DNR staff can be educational for both the students and the instructor. Here is a DNR staff person teaching students about the fishes of Minnesota.
DNR staff show students one of many techniques used to survey Minnesota fishes.
Students learn to identify Minnesota fishes
Students learning to identify Minnesota fishes. Hands-on experiences like this can grasp students' attention and hopefully ignite their passion for the environment and the creatures that inhabit it.
It is important to grasp students’ attention in the classroom, and science classrooms offer a plethora of opportunities to do so. One of the more common ways teachers engage students in a science classroom, especially those in a biological or an environmental course, is through the keeping of classroom animals. Whether teachers select amphibians, birds, fishes, insects, mammals, or reptiles, it is important to be mindful of the past, present, and future responsibilities that keeping an animal in the classroom will bring. Whenever possible, observe animals in the wild and release after brief discussion (many small wetlands contain a diverse group of animals and plants). Below are a few points that should be considered BEFORE bringing animals into the classroom.
- Buy only captive bred animals! Wild-caught animals are still common in the pet-trade, many of which are illegally collected – poached, and should be avoided when possible. It is important to ask animal sellers, pet-stores, and biological supply companies where the animal of interest originated. If they cannot tell you, they are most likely wild caught.
- Keep receipts and paperwork for animals obtained for educational use.
- Special permits, or hunting or fishing licenses may be required to take or be in possession of animals taken from the wild (e.g., native fishes, birds, frogs, turtles, endangered or threatened species) or animal parts (e.g., bird feathers, bird or turtle eggs, bird nests, or dead birds).
- For more information, or to obtain a permit to keep native game fishes in the classroom, please contact Colleen Telander in Fisheries Research.
- You must exchange water in buckets or containers used to transport aquatic animals with tap or bottled water prior to leaving any waterbody to prevent the spread of aquatic invasive species or diseases.
- Choose appropriate animals! Many species make poor captives, especially those that require specialized diets or extreme temperatures (i.e., not all animals can thrive at room temperature).
- It is often illegal to take animals from the wild, especially rare and/or state-listed species.
- Many of the popular classroom pets (e.g., frogs, salamanders, snakes, and turtles) do not make good “hands-on” animals. Regular handling can cause additional stress to animals.
- Many animal species can live a long time (in excess of 10 years). Turtles, for example, can live over 25 years. Try to choose short-lived or easily adoptable species (e.g., mice, rats, hamsters, some insects).
- Contact local non-profit organizations to adopt animals in need of a home (e.g., humane societies, MN Herpetological Society).
- Think long term! It is important to have plans in place for animals once the course is over, or during the summer months.
- Animals maintained in captivity should NOT be released back into the wild. Disease and invasive species are significant problems facing wild animal populations. Animals may appear healthy while cared for in captivity but can harbor disease or parasites that would be fatal to that individual if returned to the wild, or put a wild population at significant risk. The risk of spreading disease to wild animal populations far out-weighs the benefit of releasing an individual or two back into the wild. Learn more about amphibian and reptile, and fish diseases.
- Releasing animals into the wild may also interfere with wild animal populations’ genetic, age, and/or gender dynamics.
- It is illegal to release non-native animals in Minnesota.
- Ideally, unwanted animals should be gifted to other educators to use in their classroom(s), or to naturalists at regional or state parks. Alternatively, animals could be given to local humane or non-profit societies (e.g., Minnesota Herpetological Society – Adoption Program). If having difficulties placing unwanted animals, please contact the appropriate regional MN DNR Nongame Wildlife Specialist. Learn more about Habitattitude! |
10-13 ?We?re coming to the Americas? (Area, Population, and Physical Environment of Latin America) What is the size of the area and what is the location of Latin America? How do the terms ?mainland and rimland? and ?core and hinterland? describe the population distribution of Latin America? Size: 85 degrees long and 83 degrees wide, nearly 5,900 miles from north to south Located: south east of the United States of America, making it closer to Africa Mainland ? geographical alignment, normally a highland, smaller of the two as far as population, known for its good soil Rimland ? geographical alignment, larger of the two holding 2/3 of Latin Americas population, located about the coasts and highlands (more fragmented) Cities on the rim are the core because that is where the most power is and the most of the population Hinterlands are the less populated areas What is the pattern of population growth and urbanization? Latin America is in the second stage of the Demographic transition ? LDCs have relatively high birth rates and low death rates due to advances in the spread of medical technologies Average of 1.5% population growth (.3 being the lowest and 2.8 being the highest percent) 76% is urban ? people are leaving the rural areas and going to the cities, the poor are seen on the outskirts of the cities There are megacities (largest cities) and shantytowns (outer edges where there are poorer populations) How have humans adapted to the various aspects of the physical geography of Latin America? What is altitudinal zonation and how does it connect human activities and physical realities? They have learned to grow different agriculture on the different elevations Altitudinal Zonation ? pattern in South America (mostly look at undifferentiated highland climate, different things happen at different altitudes) Tierra Helada (highest altitudes) ? ice land Paramos ? basins able to have some agriculture, alpine meadows Supports some grain and livestock Valuable minerals Tierra Fria ? cold land Subsistence; marginalization High plateaus, basins, valleys, and mountain slopes Largest area is in the Andes Begins at 6,000 feet and goes upward to the upper limit of agriculture ? represented by hardy crops like potatoes and barley; and the tree line ? upper limit of natural tree growth at 12,000 feet Tierra Templada ? temperate land Coffee zone; European favor this area, not too cold and not too hot Contains the rugged western mountain ranges Lowland products reach their uppermost limits here Guatemala City, San Salvador, Tegucigalpa, San Jose Tierra Caliente ? hot land Area of tropical plantations (citrus, banana, chocolate) Zone embracing the tropical rainforests and tropical savanna climates Reaches up to 3,000 feet above sea level Slave trade prominent here 10-18 ?Emerging Latin American? (Culture, Economy, and Politics) How are the various ethnic groups distributed and what influences have they had on the cultural landscape? How did the European Conquest change the human geography of Latin America? How does poverty appear on the landscape? What are the two systems of agriculture, latifundia and minifundia, and how are the expressed? What is the pattern of minerals, mining, and manufacturing? How have trade relationships with the world been changing, particularly after NAFTA and CAFTA? Why would the countries of Latin America be called emerging economies? How does tourism affect the cultures and economies? What is the Geopolitical ?Dance? and how might any given country of Latin America indicate this pattern? How are geopolitical and environmental issues linked? What is the historic role of the USA with regard to Latin America? Why has it been referred to as the ?backyard? of the USA? What is the geography of drug trafficking? 10-20 ?South of the Border? (Geography of Mexico) What are the signatures of the three Historic Eras of Mexico (Native, Colonial, and Mexican)? Native: indigenous era, highly developed with larger empires and civilizations that were 1,000 years old, built architecture and religion Triple alliance: (Aztec was the capital), got all the groups to work together and round Lake Texoco, gathered resources to build up cities (mounds of dirt that were made into islands) ? largest was Tenochtitlan Colonial: when the Spanish arrived (16th to early 19th century) Territory of Spain, reshaped the cultural landscape (new plants and animals) Empires had a stratified system but the Spanish took them over Mexican: got out from under Spain When the country of Mexico was formed (1821) Revolution and independence from Spain What are the general geographic characteristics of Mexico? What are the major regions of Mexico? Where are they and how are they indicated? Mexican Plateau ? higher elevations in the south, lower in the north Balsas depression, lowland area surrounded by mountains Southern highlands Isthmus of Tehuantepec (marrow between Mexico and central America) Coastal lowlands ? greatest extent is on the gulf of Mexico, also on the pacific side Baja California Peninsula ? western side that lies on a fault line What are some of the highlights of the political geography of Mexico? How is Mexico?s economy changing? What is a maquiladora? 10-25 ?The Caribbean Beat? (Central American and the Caribbean) How do the physical realities of Central America interact with the culture, politics, and chancing economy? How would one describe Central America agriculture? Physical realities: volcanic mountains and tropical conditions Culture: richer colonials and poorer indigenous people Politics: the geopolitical dance (bounces back and forth), recently democracy but not all stable Economy: from bananas to tourism and manufacturing Do have political and economic issues Agriculture: plantation with coffee, bananas, citrus fruits and coconuts What has been the historic importance of the Panama Canal? History: Shortcut between the Atlantic and Pacific oceans 1846 ? Colombia(which then controlled Panama) and the United States signed a treaty supporting a project to cut the isthmus 1878- Colombia granted permission to a French firm to build a canal across the isthmus , went bankrupt in 1889 and was followed by another French attempt that also failed 1903 ? panama broke away from Colombia 1904 ? construction began and it is still expanding today What are the major aspects of the physical geography of the Caribbean? Greater Antilles: central mountains and coastal lowlands (Cuba, Hispaniola, Jamaica, Puerto Rico) Lesser Antilles: low, flat, limestone and/or coal based (Bahamas), volcanic (leeward and windward) Tropical; orographic precipitation (windward side gets moisture and leeward is desert like) Volcanic cones and coral reefs What are the historic cultural imprints of the people and landscape of the Caribbean, and why are they where they are? How did colonialism get expressed as ?Europe met the Indigenous people met Africa?? Colonialism brought together European, indigenous and African people in a multicultural microcosm Europeans (Spanish mainly) brought over Africans as slaves; also would bring resources and materials and goods back to their homeland Why might one describe the Caribbean as a multicultural microcosm? It is populated with Spanish, French, British, Dutch, north America, Asia, and African peoples and it has a lot of religious diversity What are the ?blessing and curses? of tourism? What are the other aspects of the Caribbean economy? Blessings: foreign exchange enters the country, major investment for recreational activities and infrastructure, promotes preservation of native crafts and historic landscapes Curses: a lot of the capital gain belongs to transitional businesses, local people do most of the work but aren?t paid well, pressure on space and natural resources Agriculture is a mainstay in economy, bananas, coffee, spices, citrus fruits and coconuts 10-27 ?Mountains of Problems? (The Andean Countries) p. 572-581 What are the major geographic regions of South America? What are the common traits shared across the Andes? What are some of the distinctive cultural landscape signatures of the Andes? 11-1 ?Big Kid on the Block? (Brazil) How does Brazil fit into the overall geographic dynamics of South America? How does Brazil?s size and resources affect its relationship with the other countries of South America? Of the world? Why are there unique environmental regions in Brazil? What are the developmental eras of Brazil and what has been their lasting importance? How does the geography of the Amazon contribute to the character of Brazil? Why might this be a new age for Brazil? How does agriculture fit into the global economy? 11-3 ?South America?s ?Down Under?? (The Southern Mid latitude Countries) What are some of the political struggles of the Southern Cone? Why are Argentina, Chile, Uruguay, and Paraguay described as the ?Southern Powers??
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Berlin traces the evolution of black society from the first arrivals in the early seventeenth century through the American Revolution, reintegrates slaves into the history of the American working class, and reveals the diverse forms that slavery and freedom assumed before cotton was the mainstay of the slave economy. You witness the transformation that occurred as the first generations of Creole slaves, free blacks, and indentured whites gave way to the plantation generations, whose exhausting labor was the sole engine of their society and whose physical and linguistic seclusion sustained African traditions on American soil. Berlin demonstrates that the meaning of slavery and of race itself was continually redefined, as the nation moved toward political and economic independence.
Berlin argues that despite an inherent power imbalance, slavery was a negotiated relationship between slave and owner. Even in the worst of circumstances, slaves always held a strong card: the threat of rebellion.
Through this negotiation, slaves not only carved out an independent social sphere from sundown to sunup, they created their own world under the owners' noses from sunup to sundown as well.
Additionally, slavery itself continually changed, and hence the terms of the relationship frequently had to be renegotiated. Slavery was not a static institution, as many historians have portrayed it. Berlin's signal contribution is to drive home that slave life differed from place to place and from time to time.
Berlin divides his study by both place and time. He identifies and examines four distinct slave societies in the first 200 years of North American slavery: the North; the Chesapeake Bay area; the coastal low country of South Carolina, Georgia, and eastern Florida; and the lower Mississippi Valley of west Florida and Louisiana.
He periodizes slave history and slaves themselves into the charter generations (charter refers to... |
Lisa Mac Donald-Clark
December 19, 2011
Abnormal psychology, also known as psychopathology, is the branch of psychology that deals with abnormal behaviors and mental illness (Hansell & Damour, (2008). Although psychopathology is a fascinating field of study it can be equally challenging, covering a broad range of disorders, illnesses, and symptoms. Defining abnormal psychology also poses a challenge. The fundamental concept of abnormal would seem simple in that it would include anything that falls outside of what societies considers normal. Narrowing the group association is essential in defining the behavior as normal or abnormal. As one develops and experiences new cultures, religions, and environments he or she will come into contact with customs that may seem unusual. Unfamiliar is not the same as abnormal, distinction between these two is vital to understanding psychopathology and those affected by mental illness. As abnormal psychology evolves and progresses in treatments, therapies, and research the central theme of the six core concepts continues to guide researcher. These six concepts define and provide understanding of abnormality. The concepts also illustrate the range between normal and abnormal behavior of individuals experiencing personality disorders. Another concept is studying cultural and historical relativism in defining and classifying abnormality in relation to environment. Pointing out the advantages and limitations of diagnosis is an additional concept. The fifth concept shows the principle of causality. The final concept is the connection between mind and body (Hansell & Damour, (2008).
Origins of Abnormal Psychology
Personality disorders and mental illness always have existed in societies. These abnormal disorders such as depression, obsessive-compulsive, and schizophrenia were misunderstood and misdiagnosed for centuries. Prior to medical research individuals suffering... |
Night eating syndrome is a condition in which people eat large
amounts of food after the evening meal, often waking up during the night to eat. People with this condition may delay their first meal of the day
for many hours.
Experts still do not know very much about night eating syndrome, but
they continue to study the condition.
What causes night eating syndrome?
Doctors are not sure what causes night eating syndrome. But some studies show that it may be related to problems with the sleep-wake cycle and certain hormones.
What are the symptoms of night eating syndrome?
People with night eating syndrome do remember eating during the night. They usually do not feel hungry in the early part of the day. They may delay their first meal of the day for many hours. Then later, after the evening meal, they may eat more than a quarter of the food they eat each day.
This pattern of eating cannot be explained by changes in the person's sleep schedule or local social routines (for example, a custom of eating late at night). People with this problem feel upset about their night eating.
People with night eating syndrome also have sleep problems, including
difficulty falling asleep and staying asleep. People with this problem are more likely to be obese. And depression is common in people who have night eating syndrome.
Night eating syndrome is different from binge eating disorder. People
with binge eating disorder usually do not have episodes of binge eating during
the night (10 p.m. to 6 a.m.). But if they do, they eat large amounts of food in
a single sitting. People with night eating syndrome tend to eat smaller amounts
of food many times during the night.
How is night eating syndrome diagnosed?
To find out if you have night eating syndrome, your doctor will ask questions about your medical history and eating patterns. Night eating syndrome often happens along with sleep problems, so your doctor may want to do tests of your sleep (polysomnography).
How this information was developed to help you make better health decisions. |
|Galileo invented many mechanical devices other than the pump, such as the hydrostatic balance. But perhaps his most famous invention was the telescope. Galileo made his first telescope in 1609, modeled after telescopes produced in other parts of Europe that could magnify objects three times. He created a telescope later that same year that could magnify objects twenty times. With this telescope, he was able to look at the moon, discover the four satellites of Jupiter, observe a supernova, verify the phases of Venus, and discover sunspots. His discoveries proved the Copernican system which states that the earth and other planets revolve around the sun. Prior to the Copernican system, it was held that the universe was geocentric, meaning the sun revolved around the earth.|
Text, design, and layout by Megan Wilde for the Electronic Text Center. This biography is based upon information culled from The Galileo Project website. |
People who have low levels of iron in their blood may be prone to hearing loss, reports Live Science. A new study suggests that when people have low levels of iron, they may develop a condition called iron deficiency anemia which is linked to varying effects throughout the body, including hearing loss.
In the study, researchers looked at the medical records of more than 300,000 adults in Hershey, Pennsylvania. They found that individuals who had iron deficiency anemia were more than twice likely to develop a specific type of hearing loss – known as combined hearing loss – compared to those without iron deficiency anemia. The participants’ ages ranged from 21 to 90. The results of the study were published in the journal JAMA Otolaryngology-Head & Neck Surgery.
Hearing loss was divided into three types: conductive hearing loss, which occurs when sound cannot travel through the ear properly; sensorineural hearing loss, which results from damage to the inner ear; and combined hearing loss, which is a combination of the two.
Researchers found that individuals with iron deficiency anemia were 2.4 times more likely to have combined hearing loss compared with those who did not have low levels of iron. Individuals with iron deficiency anemia were also 1.8 times more likely to have sensorineural hearing loss. No link, however, was found between iron deficiency anemia and conductive hearing loss.
Kathleen Schieffer, lead study author and doctoral student at Pennsylvania State University College of Medicine, wrote in the study:
Earlier research suggested several potential reasons why iron deficiency anemia may be linked to hearing loss and, in particular, to sensorineural hearing loss.
Researchers also wrote: “Sensorineural hearing loss can develop when damage occurs to the tiny blood vessels in the ear, and iron deficiency anemia can put a person at risk for such damage. For example, iron deficiency anemia has been linked to several blood disorders that can cause such damage to these delicate blood vessels. In addition, the condition has been linked to problems with myelin, a sheath that surrounds nerve cells, including the nerve that runs from the ear to the brain.”
The researchers noted, however, that although their findings suggest that there is an association between certain types of hearing loss and iron deficiency anemia, it does not prove a cause-and-effect relationship between the two. |
Among the many ways to sense temperature, combinations of advanced optical principles used with optical fibers offer very different approaches, with application advantages and implementation limitations.
Temperature is the most widely sensed physical parameter; it’s that simple. What’s not simple is the many ways we have of measuring it through the use of sensors such as thermocouples, RTDs, diodes, thermal imaging, and the expansion of materials, to cite just a few techniques (it’s a very long list).
There’s also the common challenge in many situations of getting that temperature sensor to be “close enough” or properly situated to make the measurement, to make it accurately, to work reliably, and even survive the measurement environment, as there are often have issues of access, temperature extremes, vibration, or harsh atmosphere. Finally, the sensor must be observable and eventually report the changes via readout system, which is usually electronic. In short: temperature is widely measured, sometimes with ease and often with difficulty, especially as the temperature goes into extreme cold or hot regions.
The reality is that engineers of all types have a conflicting relationship with temperature. On one side, it’s a cause of change in component and structural parameters such as shifts causing physical changes and electrical errors, and even eventual failure in many cases. Among these effects are diode voltage-drop change; resistance change; crystal-frequency shift; fractures due to dimensional changes, thermal coefficients, and materials mismatch, and more. These changes are unavoidable as they are due to basic physics and often must be dealt with. Among the techniques for dealing with temperature coefficient-induced changes are the use of:
- carefully selected materials;
- component burn-in and aging;
- thermally controlled oven;
- data calibration and correction;
- ratiometric or balanced electrical topologies where changes cancel out, such as in the Wheatstone bridge, Figure 1:
- mechanical matching of materials to cancel material-elongation effects, a seen in the gridiron (or “banjo”) pendulum developed in the early 1700s by John Harrison for his legendary chronometer, Figure 2.
On the other hand, the fact that temperature affects so many physical factors can be leveraged to measure that temperature (or other factors) via a wide variety of electrical and mechanical implementations. For example, the bimetallic strip used in older thermostats is an all-mechanical example (Figure 3), while the Seebeck effect embodied by thermocouples is an electrical one.
Add fiber to the temperature-measurement menu
In recent years, the development of high-purity, consistent, hair-thin light conduits made of optical glass has completely changed the nature of data links, ranging from close-in, short-range ones of a few meters to submarine cables which run on the ocean floor for thousands of kilometers. These optical fibers are optimized for different data links by their material specifics and doping, diameters, and cladding. Most – but not all – are “stepped-index” fibers where a glass core with a tightly controlled index of refraction and precise diameter is clad with a glass or glass-like material of having a lower refraction index. Much of the pioneering work on the use of optical fibers for data links was done by Charles K. Kao, work for which he was awarded the Nobel Prize in Physics in 2009
As long as the incident light enters the core at or below the critical angle for that pairing of core and cladding indices of refraction, the light stays inside the fiber as it propagates along its length, Figure 4. This is called “total internal reflection,” While the credit for its discovery is not known with certainty, the Dutch physicist, astronomer, mathematician, and inventor Christiaan Huygens explored the basic underlying physics principles in the late 1600s, as did Isaac Newton. (They first observed it experimentally as the light was sent into a stream of water coming out of a hole in the side of a pitcher while not exiting the steam’s sides.
Of course, there’s more to the use of optical fibers for data transmission than shining a bright light or laser beam directly into the fiber. There are issues of wavelengths, coupling losses, fiber attenuation, single and multimode propagation, vectors and polarization, optical sources and receivers, and more. The huge growth in fiber-optic use has also brought major advances in theoretical and applied optical physics, monochromatic and tunable lasers, optical materials and crystals, electro-optical systems and integration, and integrated microfabrication similar to silicon-based MEMS, and more. Many structures are known in theory, but large and complex in actual execution are now being reduced to small, mass-produced components and systems.
While most engineers are familiar with optical fibers for conveying light for illumination or data communications, they may not be as familiar with other applications of these fibers and related structures. Just as with any physical material, the first-, second-, and third-order performance attributes of glass fibers are affected by stimuli such as pressure, bending, temperature, and more. Scientists and engineers have studied the nature of these changes, quantified them, and determined ways to exploit them – in the positive sense of the word – to use them to measure physical parameters unrelated to data communications. (Note that we are talking about glass-based fibers only; lower-cost plastic fibers are available but useful only for very short-distance links or conveying illumination but not data.)
This article will look at two of many basic optical structures and principles – based on the fiber Bragg grating (FBG) and the Mach-Zehnder interferometer (MZI) – used for fiber-based sensing. While the principles of FBGs and MZIs have been known for over a century, they required larger, table-top size assemblies and support to be useful until the last few decades. Now, however, they are being fabricated in optics-compatible crystal materials such as lithium niobate ((LiNbO3) and gallium arsenide (GaAs). Once again, there have been connections and synergy among different advances and technologies that make this possible; for example, the MZI advances in ring-laser and fiber-optic gyroscopes and MEMS and thin-films for semiconductors contributed to the advances which make their use as sensors practical and effective.
While full descriptions of the use of optical fibers, FBGs, and MZIs require deep-level physics and associated equations, it is possible to understand their operation and application without them properly. The principles of using glass fibers and fiber optics will apply to sensing temperature, pressure, bending, magnetic fields, and more, but we will focus on temperature.
The next part of this article will explain FBGs and MZIs as they apply to sensing.
Related EE World Content
- Undersea optical-fiber cables do double-duty as seismic sensors, Part 1: Context
- Undersea optical-fiber cables do double-duty as seismic sensors, Part 2: Application
- Optical amplifiers, Part 1: Applications and considerations
- Optical amplifiers, Part 2: Basic implementations
- Wheatstone bridge, Part 1: Principles and basic applications
- Wheatstone bridge, Part 2: Additional considerations
- Gyroscopes, Part 2: Optical and MEMS implementations
- What are cryogenic temperature measurements? Part 1
- What are cryogenic temperature measurements? Part 2
- Fiber Optic Sensor Measures Tiny Magnetic Fields
- RP Photonics Consulting GmbH, “Optical Temperature Sensors”
- Opsens Solutions, “Fiber Optic Temperature Sensors”
- Micronor LLC, “TS Series Temperature Sensors”
- Micronor LLC, “Why Fiber Optic Sensing?”
- Wikipedia, “Fiber-optical thermometer”
- InTechOpen, “Optic-Fiber Temperature Sensor”
- RF Wireless World, “Fiber Optic Temperature Sensor structure, working, advantages, disadvantages”
- RP Photonics, “Optical Temperature Sensors”
- Research Gate, “Applications of fibre optic temperature measurement”
- Sensor Letters, “A New Fiber Optical Thermometer and its Application for Process Control in Strong Electric, Magnetic, and Electromagnetic Fields”
- Research Gate, “Ultra-high Sensitive Temperature Sensor Based on Multimode Fiber Mach-Zehnder Interferometer”
- Wikipedia, “Brillouin scattering”
- Washington University/St. Louis, “What is Raman scattering?”
- Georgia State University, “Raman scattering”
- BW Tech, “Theory of Raman Scattering”
- Nano Photon, “What is Raman spectrum?”
- RP Photonics, “Rayleigh Scattering”
Background and Related
- Wikipedia, “Fiber Bragg Grating”
- Laser Focus World, “Distributed fiber-optic hydrophone is based on heterodyne coherent detection”
- Laser Focus World, “Fiber-optic communications: Tailoring the fiber to the task”
- Wikipedia, “Michelson–Morley experiment”
- NASA, “Sensing Magnetic Fields: Using an Innovative Optical Waveguide Fiber Bragg Grating”
- OSA Publishing, “All-fiber-optic vector magnetic field sensor based on side-polished fiber and magnetic fluid”
- Photonics, “LIGO Continues Making Waves”
- The Optical Society, “LIGO-Virgo in OPN” |
This article will help you to understand more about osteoporosis wrist exercises. Are you experiencing weakness in your grip? Or can you observe that your fingernails are also becoming brittle daily? If yes, then you might have early signs of osteoporosis.
What is Osteoporosis?
Osteoporosis is a medical condition that is characterized by weak thinning of bones. Bone loss that comes with this is often unseen unless a sudden break of bones or “fracture” happens – thus calling it – The Silent Disease.
How does Osteoporosis happen?
Bone typically provides our body structure. It is a connective tissue infused with calcium, bone cells, and other minerals. The body continuously breaks down old bone tissue and reforms new bone tissue in remodeling. This helps build a more substantial bone, promote growth, and repair damaged bone tissues. During our early 30s, we usually make more new bone tissues than we lose. However, at age 35, the breakdown of old bone tissue is quicker than the build-up of new ones, resulting in decreased bone mass. A typical bone appears like a honeycomb matrix, while an osteoporotic bone has larger holes or is more porous. If a low bone mass, also known as Osteopenia, continues, it will lead to Osteoporosis.
A lot of factors can affect one’s chance of developing osteoporosis – this includes:
- Sex: Women are more likely to develop osteoporosis than men. Estrogen, a female sex hormone responsible for developing and maintaining the female reproductive system & characteristics, is needed for healthy bones. It helps promote the activity of osteoblast (bone formation cell). However, during menopause, this hormone decreases, which leads to reduced bone density.
- Age: The older you get, the higher the risk. At the age of 35, the rate at which the breakdown of old bone tissue increases more than the buildup of new ones, resulting in decreased bone mass.
- Family history
- Hormone levels: increased thyroid hormones can cause bone loss
- Dietary Factors: low to no calcium intake
- Presence of other medical conditions: Celiac disease, inflammatory disease, kidney or liver disease, cancer, multiple myeloma, rheumatoid arthritis
- Lifestyle: increased alcohol consumption — two alcoholic drinks a day increase the risk of having osteoporosis
Signs and symptoms
The most common areas where osteoporotic fracture happens are the wrists, hips, and spine. However, it can also occur in other areas, such as the arm or pelvis.
Osteoporosis fractures in the forearm, especially in wrists, are more common than in the hips and the spine. Symptoms may include decreased grip strength, pain, swelling of the wrist/base of the thumb, and bending of the wrist at an unnatural angle.
Frequently, osteoporosis cannot be seen or diagnosed unless trauma to the bone has occurred. However, if you have suspected osteoporosis, various tests can be done to confirm the condition.
- Bone Density Scan
Bone density scan is the most commonly used test. A bone density scan is a short, painless procedure that measures bone mineral density (BMD). Bone mineral density is the amount of bone tissue present in a segment of a bone.
The following test can be done to diagnose bone fractures due to osteoporosis:
- Bone X-ray: It uses a small dose of ionizing radiation to develop images of any bone. It is the fastest and most effortless test to determine bone fractures within the body.
- Computed Tomography (CT) Scan for Spine: It is a fast, painless, and noninvasive diagnostic imaging to diagnose spinal column injuries due to osteoporosis.
- Magnetic Resonance Imaging (MRI) for the Spine: It uses radio waves and a magnetic field to evaluate underlying fracture diseases such as osteoporosis and cancer.
How is Osteoporosis treated?
The goal of treatment for osteoporosis may focus on slowing or stopping bone loss or preventing fractures. Treatments may include exercise, lifestyle changes, vitamin and mineral supplements, and medications. While fall prevention, smoking cessation, reduction of alcohol intake, and bisphosphonate therapy may also be made to prevent fractures.
- Bisphosphonate: The most prescribed medication for osteoporosis is bisphosphonates. These help slow down bone loss, thus reducing the risk of fractures. It can be taken orally (by mouth), intravenous infusion (through a drip), or injection.
Regular physical activity like osteoporosis wrist exercises can help in protecting bones. Here are some of the benefits of exercising:
- Increase muscle strength
- Improve balance
- Decrease the risk of bone fracture
- Maintain or improve posture
- Decrease pain
- Increased mobility or range of motion
- Bone loss reduction
You were working and exercising your muscles matters just as much as building up bone. It can slow the process of bone loss that happens with osteoporosis and may help prevent fractures. However, only some exercise plans work for everyone with osteoporosis. Factors like fracture risk, muscle strength, range of motion, level of physical activity, and balance should be considered to develop the most appropriate plan for each case. You should always consult your doctor and physical therapist to plan a safe exercise routine.
Meanwhile, here are some of the recommended wrist exercises for people with osteoporosis:
- Weight-bearing Exercises such as dancing, jogging, hiking, jumping rope
- Muscle-Strengthening Exercises such as push-ups, squats, and equipment like elastic exercise bands, free weights, and weight machines can be used.
- Non-Impact Exercises such as Tai Chi
You can read this article for more information about Bone health:
A lot of people know osteoporosis usually happens in the hips and spine. However, that isn’t the case. Osteoporosis in the forearm is more common than in the hip or spine. The forearm, specifically the wrist, is more susceptible to fractures.
Osteoporosis Wrist Strengthening Exercises
1. Lateral Wrist Exercise
These osteoporosis wrist exercises target the wrist extensors and flexors. In doing so, the practice helps to restore movement in your wrist while also improving the flexibility of the wrist muscles.
- Begin standing with your arms in front of you, palms facing down.
- Bend your wrists forward and backward until you feel a light, pain-free stretch.
- Repeat 10 times on each arm.
- Do 3 sets of 10 repetitions.
Alternatively, seated with your forearm supported by a table, you can also do this osteoporosis wrist exercise. Your wrists and fingers should hang over the edge (you can also put a rolled-up towel for padding underneath your forearm). Then bend your wrists forward and backward, as in the picture above.
Advanced: you can also add a 1- or 2-lbs—Dumbbell for extra resistance (and benefit to your forearm).
2. Seated Wrist Curl with Dumbbell
This seated wrist curl helps to develop your flexor muscles: Wrist flexors, supinators, pronators, and brachialis.
Start light with this exercise! Do not use heavy weights if you are beginning or have a wrist injury. Wear a wrist wrap if you need support.
- In a seated position on a stability ball or chair, place your forearm on your thigh with your palm facing upward.
- Using a 1- 5 lb hand weight (the weight should be just enough, so you feel fatigued at the end of your set), flex your wrist upward.
- Focus on keeping your forearm well placed against your thigh for stability. You can also use your opposite hand and thigh as pictured.
- Do 3 sets of 10 repetitions.
While in between sets for your seated wrist curl, you can add the seated wrist reverse curls. This will target your extensor muscles.
- Start in the same seated position with your forearm on your thigh. But this time, your palm will face downward.
- Using your weight, extend your wrist upward fully.
- Do 3 sets of 10 repetitions.
Progression: Once these exercises are no longer a challenge, increase the weight by 1 pound and add an extra set too.
3. Tennis Ball Grip Strength
The Tennis Ball Grip Strength targets your wrist flexors and extensors.
- Grasp the tennis ball in one hand while sitting or standing.
- Slowly squeeze it as hard as possible, and hold for 2-3 seconds.
- Slowly release your squeeze.
- Rest for 3 seconds and then repeat 10 times.
- Switch hands and repeat steps 1-4 above.
- Repeat twice on each hand (for 3 sets in total for each hand).
Progression: Once this exercise is no longer a challenge, add an extra set and increase your squeeze time by 1-2 seconds.
Osteoporosis that leads to fractures can seriously affect our way of life. Fractures take longer to heal and could lead to complications like a poor alignment of the bone, infection, nerve damage, compartment syndrome, fat embolism, and more.
Fortunately, although bone loss is natural upon aging, — with proper diet and exercise — early prevention can slow the process.
It is always best to consult a doctor if you think you’re at risk or already have osteoporosis. They can create an appropriate treatment plan to prove your bone health, prevent fractures and reduce the risk of other complications. |
Some robotic prosthetics currently in development are connected to the user via a socket which detects electrical signals from muscle movements. One challenge with this technology is maintaining an electrical connection to the muscle via sensors placed on the skin inside the socket. For example, this connection can be lost because of sweat, which can inhibit the prosthetic hand’s ability to function.Fabricating and calibrating the system for a user is also quite expensive.
The researchers’ prototype sensor system is said to avoid this pitfall by detecting mechanical signals, instead of electrical signals, from tiny vibrations produced by muscle fibres as they move when muscles flex.These vibrations can be sensed and passed to a robot hand to make it move in response.
The team caution that they have not yet carried out patient clinical trials with the technology. They still have a number of refinements to complete before the sensor and motion tracking system can be commercialised. However, they believe their work is a step forward in making robotic prosthetics more robust in their design, which could widen their usefulness for patients.
The team have carried out a preliminary demonstration of the system with Alex Lewis who lost his legs, his right arm and use of his left arm following a rare infection.
To operate the robotic hand Lewis had a small arm band placed around his bicep, which has a muscle sensor and motion tracking electronics embedded into it. When he flexed his bicep the vibrations made were detected by the sensor, interpreted as signals and transmitted to a computer. A program then executed a mathematical algorithm designed to isolate Lewis’s muscle signal and filter out other arm motions and sounds, converting it into a command for the robotic hand.
Lewis had the option of activating a three fingered pinch that could enable movements such as picking up a small object like a set of keys, and a power grip that could enable the prosthetic to grasp a larger object such as a glass of water.
Future refinements to the technology will include adding more sensors to increase the range of commands and isolating the range of vibration interference that may make the hand open or close unexpectedly. The team also plan to refine the device so that it is more portable and enables the user to self-calibrate.
Lewis said: “It is really exciting to be part of this project to test the robotic hand system. Current prosthetics can be very cumbersome, so any technology that can reduce the burden on users is an important step forward. I look forward to seeing this device developed further.”
In the future, the team predict that the sensor system could also be adapted so that it could be used to control other technologies and appliances around the home, to further benefit people living with disabilities. |
Mastering the Alphabet: A Close-up on Languages from A to Z
Language is the ultimate tool for human communication, allowing us to effectively convey our thoughts, ideas, and emotions. With over 7,000 recognized languages in the world, each unique and captivating, exploring the diverse alphabets is like embarking on an enchanting journey across continents and cultures.
A is for Arabic, a flowing script that originated in the Arabian Peninsula and is now spoken by millions in the Middle East and North Africa. Known for its elegant curves and intricate characters, Arabic is not only a language but also an art form.
Moving across to Asia, B takes us to Bengali, the sixth most spoken language in the world. With its curved and rounded script, this South Asian language is renowned for its poetic beauty and rich literary heritage.
C brings us to Mandarin Chinese, an ancient language that dates back thousands of years. Its logographic writing system, composed of thousands of unique characters, tells a story of China’s profound history and intricate cultural nuances.
Next on our journey is D for Devanagari, the script used for writing Hindi, Sanskrit, and several other languages of the Indian subcontinent. This script is characterized by its distinctive horizontal top line and the loop-like shape of its characters.
E takes us to the Old World, where we encounter the elegant script of Ethiopian Amharic. This alphabet, known as Fidel, is said to be one of the oldest in the world and is used to write several languages spoken in Ethiopia.
Our exploration continues to F for French, a language that evokes images of romance, literature, and art. The Latin-based script used in French is both beautiful and practical, making it one of the most widely learned second languages worldwide.
G leads us to Greek, which has been of great influence in the fields of science, philosophy, and literature. Its magnificent and distinctive characters, derived from the Phoenician alphabet, continue to captivate minds and inspire new generations of scholars.
H brings us to Hebrew, an ancient and sacred language that holds deep religious significance for millions. Written from right to left, Hebrew is rich in symbolism and mystery, with a script that traces back to biblical times.
Crossing the Atlantic, we arrive at I, representing English and the Latin alphabet. English has become the lingua franca, connecting people from all walks of life. Its simplicity and straightforwardness make it accessible to many, with the Latin script becoming a global standard.
J takes us to Japan, where we encounter the intricate characters of Kanji, borrowed from Chinese and combined with syllabic systems Hiragana and Katakana. The combination of these scripts creates a visual harmony that truly reflects Japan’s unique culture.
Next on our alphabetical tour is Korea, represented by Hangeul. Developed during the 15th century, Hangeul has a philosophical approach to its arrangement of characters, mirroring the phonetic structure of words and sounds.
M takes us to the romantic language of Spanish, known for its passionate speech and vibrant culture. With over 460 million native speakers worldwide, the Latin alphabet is adorned with accents and distinctive characters that add a touch of poetic flair.
N brings us to the land of Vikings and Nordic legends, where we encounter the runes of Old Norse. These ancient characters convey a rich history and have become a fascination for lovers of ancient cultures and languages.
O symbolizes one of the most widely spoken languages globally, Portuguese. Originating from the Latin alphabet, it is a mellifluous script that reflects the soul of Brazil and the charm of Portugal, both known for their remarkable literature and music.
Continuing our journey, P introduces us to the Russian Cyrillic alphabet. With its round shapes and intricate letter combinations, it is visually captivating. Russian is a language that has produced remarkable literature and holds an important place in the cultural tapestry of Eastern Europe.
S brings us to Arabic once again, showcasing the script used for writing Urdu. With its unique characters and elongated strokes, Urdu evokes a sense of grace and beauty, making it the language of poets and artists.
Our adventure through the alphabets reaches its peak at Z, closing with the intriguing script of Zulu. This South African language embodies the spirit of unity and diversity, with its characters designed to create harmony and express the vibrant culture of the Zulu people.
The world’s alphabets bear witness to the rich tapestry of languages that have evolved over centuries and across continents. Mastering the alphabet and delving into the world of languages from A to Z allows us to appreciate and understand the diverse cultures that shape our global society. So, let us immerse ourselves in this linguistic journey, where every letter unfolds a captivating story. |
THE POLYMERASE CHAIN REACTION (PCR)
The polymerase chain reaction (PCR) is a procedure for amplifying tiny amounts of DNA and is used when there is too little DNA, or the DNA is too degraded for DNA fingerprinting via the RFLP approach. The details of PCR have already been discussed. PCR machines can amplify a segment of DNA (100 to 3000 bp long) in a few hours, starting from only a picogram (10 –12 g), although microgram (10 –6 g) quantities or larger are better. In fact, PCR can be used successfully to analyze DNA from a single cell.
Whereas classical DNA fingerprinting
requires relatively long strands of DNA, PCR can be used on short segments of
DNA. PCR is most useful for regions of the DNA with high individual
variability. Small regions with high person-to-person variability are the best
to amplify. If the sequences of two samples match in several highly variable
regions, they are probably from the same person. In current practice, forensic
DNA analysis is almost all done by PCR-based methodology.
Once the DNA from the forensic sample has
been amplified by PCR, it is compared with DNA from the suspect, or suspects. Spots of both
DNA samples are bound to a membrane and tested for binding to a DNA probe that
is either radioactive or tagged with a fluorescent dye. The probe either binds
or doesn’t bind, so any spot is either positive or negative. This kind of test
is known as a dot blot ( Fig. 24.7 ). Thus, the major difference between PCR
and DNA fingerprinting is that DNA fingerprinting looks for differences in
fragment sizes, whereas PCR tests for the presence or absence of specific
stretches of DNA with identical (or almost identical) sequences. If necessary, segments
of DNA that have been amplified by PCR can be fully sequenced. In this case, we
do not need to rely just on hybridization as an indication of related
sequences. In the future, such sequence identification will most likely be done
by DNA array technology, which allows simultaneous analysis of multiple short
It is possible to analyze several STR
loci simultaneously by running several PCR reactions in the same tube using
different primers ( multiplex PCR ; Fig. 24.8 ). This requires that the multiple
sets of primers do not interfere with each other, which is often difficult to
achieve when running six or more amplifications together. Nonetheless, commercial
kits are now available that can run up to 13 STR analyses in one reaction tube.
Such a multiplex analysis gives a gel track with up to 2 N bands (where N
is the number of loci analyzed). For this example, 13 STR loci would
produce 26 bands. Fewer bands will be seen in individuals who are homozygous at
any of the chosen loci.
Despite the apparent complexity, the
STRs that are used derive from known sequences at known chromosomal locations,
and hence the individual bands can be identified and entered into computer
databases. Multiplex STR analysis is the basis of the national database set up
in the UK in 1995. Similar databases are now used in other European nations
and, since 1998, in the United States. |
Long denigrated as vestigial or useless, the appendix now appears to have a reason to be – as a “safe house” for the beneficial bacteria living in the human gut.
Drawing upon a series of observations and experiments, Duke University Medical Center investigators postulate that the beneficial bacteria in the appendix that aid digestion can ride out a bout of diarrhea that completely evacuates the intestines and emerge afterwards to repopulate the gut. Their theory appears online in the Journal of Theoretical Biology.
“While there is no smoking gun, the abundance of circumstantial evidence makes a strong case for the role of the appendix as a place where the good bacteria can live safe and undisturbed until they are needed,” said William Parker, Ph.D., assistant professor of experimental surgery, who conducted the analysis in collaboration with R. Randal Bollinger, M.D., Ph.D., Duke professor emeritus in general surgery.
The appendix is a slender two- to four-inch pouch located near the juncture of the large and small intestines. While its exact function in humans has been debated by physicians, it is known that there is immune system tissue in the appendix.
The gut is populated with different microbes that help the digestive system break down the foods we eat. In return, the gut provides nourishment and safety to the bacteria. Parker now believes that the immune system cells found in the appendix are there to protect, rather than harm, the good bacteria.
For the past ten years, Parker has been studying the interplay of these bacteria in the bowels, and in the process has documented the existence in the bowel of what is known as a biofilm. This thin and delicate layer is an amalgamation of microbes, mucous and immune system molecules living together atop of the lining the intestines.
“Our studies have indicated that the immune system protects and nourishes the colonies of microbes living in the biofilm,” Parkers explained. “By protecting these good microbes, the harmful microbes have no place to locate. We have also shown that biofilms are most pronounced in the appendix and their prevalence decreases moving away from it.”
This new function of the appendix might be envisioned if conditions in the absence of modern health care and sanitation are considered, Parker said.
“Diseases causing severe diarrhea are endemic in countries without modern health and sanitation practices, which often results in the entire contents of the bowels, including the biofilms, being flushed from the body,” Parker said. He added that the appendix’s location and position is such that it is expected to be relatively difficult for anything to enter it as the contents of the bowels are emptied.
“Once the bowel contents have left the body, the good bacteria hidden away in the appendix can emerge and repopulate the lining of the intestine before more harmful bacteria can take up residence,” Parker continued. “In industrialized societies with modern medical care and sanitation practices, the maintenance of a reserve of beneficial bacteria may not be necessary. This is consistent with the observation that removing the appendix in modern societies has no discernable negative effects.”
Several decades ago, scientists suggested that people in industrialized societies might have such a high rate of appendicitis because of the so-called “hygiene hypothesis,” Parker said. This hypothesis posits that people in “hygienic” societies have higher rates of allergy and perhaps autoimmune disease because they — and hence their immune systems — have not been as challenged during everyday life by the host of parasites or other disease-causing organisms commonly found in the environment. So when these immune systems are challenged, they can over-react.
“This over-reactive immune system may lead to the inflammation associated with appendicitis and could lead to the obstruction of the intestines that causes acute appendicitis,” Parker said. “Thus, our modern health care and sanitation practices may account not only for the lack of a need for an appendix in our society, but also for much of the problems caused by the appendix in our society.”
Parker conducted a deductive study because direct examination the appendix’s function would be difficult. Other than humans, the only mammals known to have appendices are rabbits, opossums and wombats, and their appendices are markedly different than the human appendix.
Parker’s overall research into the existence and function of biofilms is supported by the National Institutes of Health. Other Duke members of the team were Andrew Barbas, Errol Bush, and Shu Lin. |
Proof of Concept: What It Is and Why It’s Important
In the world of business and technology, the term “proof of concept” (POC) is often used to describe a demonstration of the viability of a product or idea. This article will explore the concept of POC, its significance, and how it is implemented in various fields.
The Basics of Proof of Concept
Proof of concept refers to the process of validating the feasibility and potential success of a project or initiative. It is a critical step in the development of new products, services, or technologies, as it helps to determine whether an idea is practical and worth pursuing further. A successful POC provides evidence that a concept can be realized and is worth investing in.
- POC is often used in the early stages of a project to test the viability of an idea.
- It helps to identify potential technical and operational challenges.
- POC is used to demonstrate the value and potential impact of a concept to stakeholders.
- It is an essential tool for risk management and decision-making.
- POC can also be used to attract potential investors or partners.
The Importance of Proof of Concept
Conducting a proof of concept is crucial for several reasons. Firstly, it helps to mitigate the risks associated with investing time, resources, and money into an unproven idea. By testing the feasibility of a concept in a controlled environment, organizations can identify and address potential challenges and roadblocks early on, reducing the likelihood of costly failures down the line.
Moreover, a successful POC provides confidence and validation for stakeholders, including investors, partners, and internal decision-makers. It demonstrates the potential value and impact of a concept, making it easier to secure buy-in and support for further development and implementation.
Implementing a Proof of Concept
The process of conducting a proof of concept can vary depending on the nature of the project and the industry. However, there are several common steps and best practices that can be followed to ensure a successful POC.
- Define clear objectives: Clearly outline the goals and expected outcomes of the POC to provide a roadmap for the testing process.
- Identify success criteria: Establish specific metrics and benchmarks for evaluating the success of the POC.
- Assemble a dedicated team: Assign a cross-functional team with the necessary skills and expertise to execute the POC effectively.
- Select appropriate methodologies: Choose the right tools, technologies, and methodologies for testing and validation.
- Document the process: Keep detailed records of the POC process, including findings, challenges, and key learnings.
Challenges and Limitations
While proof of concept is a valuable process, it is not without its challenges and limitations. One of the common challenges in conducting a POC is the potential for bias or skewed results. As the POC is often conducted in a controlled environment, the real-world implications and complexities of a concept may not be fully captured.
Additionally, POC can be resource-intensive and time-consuming, requiring significant investment in terms of personnel, technology, and infrastructure. In some cases, organizations may struggle to allocate the necessary resources for a comprehensive POC, which can impact the quality and reliability of the results.
Examples of Proof of Concept
Proof of concept is utilized in a wide range of industries and fields. From healthcare to finance to technology, organizations leverage POC to validate new ideas and innovations. One example of a successful POC is the development of autonomous vehicles.
In the early stages of autonomous vehicle technology, companies conducted extensive POCs to test the feasibility and safety of self-driving cars. These POCs involved rigorous testing of the technology in various driving conditions and scenarios, providing critical data and insights to support further development and eventual deployment.
Future Trends in Proof of Concept
The landscape of proof of concept is constantly evolving, driven by advancements in technology and changing market dynamics. As organizations continue to pursue innovation and agility, the need for efficient and robust POC processes will become increasingly important.
One emerging trend is the use of AI and machine learning in conducting POCs. These technologies can accelerate the testing and validation process, enabling organizations to gather and analyze large volumes of data more effectively. Additionally, the rise of cloud-based services and platforms has the potential to streamline POC activities, providing scalable and cost-effective solutions for testing new concepts.
Proof of concept is a critical step in the development and validation of new ideas, products, and technologies. By conducting a thorough and well-executed POC, organizations can minimize risks, attract support from stakeholders, and pave the way for successful implementation and commercialization. |
So you have seen the above image by now, right?
Let me explain the above image in short.
GeH4 lewis structure has a Germanium atom (Ge) at the center which is surrounded by four Hydrogen atoms (H). There are 4 single bonds between the Germanium atom (Ge) and each Hydrogen atom (H).
If you haven’t understood anything from the above image of GeH4 lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of GeH4.
So let’s move to the steps of drawing the lewis structure of GeH4.
Steps of drawing GeH4 lewis structure
Step 1: Find the total valence electrons in GeH4 molecule
In order to find the total valence electrons in GeH4 molecule, first of all you should know the valence electrons present in germanium atom as well as hydrogen atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)
Here, I’ll tell you how you can easily find the valence electrons of germanium as well as hydrogen using a periodic table.
Total valence electrons in GeH4 molecule
→ Valence electrons given by germanium atom:
Germanium is group 14 element on the periodic table. Hence the valence electrons present in germanium is 4.
You can see the 4 valence electrons present in the germanium atom as shown in the above image.
→ Valence electrons given by hydrogen atom:
Hydrogen is group 1 element on the periodic table. Hence the valence electron present in hydrogen is 1.
You can see that only 1 valence electron is present in the hydrogen atom as shown in the above image.
Total valence electrons in GeH4 molecule = valence electrons given by 1 germanium atom + valence electrons given by 4 hydrogen atoms = 4 + 1(4) = 8.
Step 2: Select the central atom
For selecting the center atom, you have to remember that the atom which is less electronegative remains at the center.
(Remember: If hydrogen is present in the given molecule, then always put hydrogen outside.)
Now here the given molecule is GeH4 and it contains germanium atom (Ge) and hydrogen atoms (H).
You can see the electronegativity values of germanium atom (Ge) and hydrogen atom (H) in the above periodic table.
If we compare the electronegativity values of germanium (Ge) and hydrogen (H) then the hydrogen atom is less electronegative. But as per the rule we have to keep hydrogen outside.
So here the germanium atom (Ge) is the center atom and the hydrogen atoms (H) are the outside atoms.
Step 3: Connect each atoms by putting an electron pair between them
Now in the GeH4 molecule, you have to put the electron pairs between the germanium atom (Ge) and hydrogen atoms (H).
This indicates that the germanium (Ge) and hydrogen (H) are chemically bonded with each other in a GeH4 molecule.
Step 4: Make the outer atoms stable
Now in this step, you have to check the stability of the outer atoms.
Here in the sketch of GeH4 molecule, you can see that the outer atoms are hydrogen atoms.
These outer hydrogen atoms are forming a duplet and hence they are stable.
Also, in step 1 we have calculated the total number of valence electrons present in the GeH4 molecule.
The GeH4 molecule has a total 8 valence electrons and all these valence electrons are used in the above sketch of GeH4.
Hence there are no remaining electron pairs to be kept on the central atom.
So now let’s proceed to the next step.
Step 5: Check the octet on the central atom
In this step, you have to check whether the central germanium atom (Ge) is stable or not.
In order to check the stability of the central germanium (Ge) atom, we have to check whether it is forming an octet or not.
You can see from the above picture that the germanium atom is forming an octet. That means it has 8 electrons.
And hence the central germanium atom is stable.
Now let’s proceed to the final step to check whether the lewis structure of GeH4 is stable or not.
Step 6: Check the stability of lewis structure
Now you have come to the final step in which you have to check the stability of lewis structure of GeH4.
The stability of lewis structure can be checked by using a concept of formal charge.
In short, now you have to find the formal charge on germanium (Ge) atom as well as hydrogen (H) atoms present in the GeH4 molecule.
For calculating the formal charge, you have to use the following formula;
Formal charge = Valence electrons – (Bonding electrons)/2 – Nonbonding electrons
For Germanium (Ge) atom:
Valence electrons = 4 (because germanium is in group 14)
Bonding electrons = 8
Nonbonding electrons = 0
For Hydrogen (H) atom:
Valence electron = 1 (because hydrogen is in group 1)
Bonding electrons = 2
Nonbonding electrons = 0
From the above calculations of formal charge, you can see that the germanium (Ge) atom as well as hydrogen (H) atom has a “zero” formal charge.
This indicates that the above lewis structure of GeH4 is stable and there is no further change in the above structure of GeH4.
In the above lewis dot structure of GeH4, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of GeH4.
I hope you have completely understood all the above steps.
For more practice and better understanding, you can try other lewis structures listed below.
Try (or at least See) these lewis structures for better understanding:
|FCN Lewis Structure
|HClO2 Lewis Structure
|C2Cl4 Lewis Structure
|CF3Cl Lewis Structure
|PF3Cl2 Lewis Structure
|C2H4Cl2 Lewis Structure
Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. He is a founder of Pediabay and is passionate about helping students through his easily digestible explanations.
Read more about our Editorial process. |
The Asia of remote prehistory was very different from the teeming continent and islands of today. Its population was tiny and dispersed, living mostly on the seacoasts and the plains of the big rivers, each small group of humanity separated from the others by virgin forest, full of wild animals. Families stayed together, developed into clans for mutual protection. Life was precarious, death came early and was often sudden and violent.
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We all know what multiplication is but we don't really know the rules, or properties of multiplication. Multiplication Properties include the following properties:
- Commutative Property of Multiplication
- Associative Property of Multiplication
- Identity Property of Multiplication
- Zero Property of Multiplication
I know that all of these big and fancy words seem like a lot of stuff, but it's actually pretty easy. Especially once you know what they are and have solved some examples!
Commutative Property of Multiplication
Definition: The order of factors can be changed, but the product stays the same.
Associative Property of Multiplication
Definition: You can change the grouping of the factors. The product stays the same.
Identity Property of Multiplication
Definition: When you multiply any number by 1, the product is that number.
Zero Property of Multiplication
Definition: When you multiply any number by 0, the product is 0.
More about the Properties of Multiplication
I hope that after reading the above information on the Properties of Multiplication, you got an idea of what each is. Even if you already knew these, this was probably a good review! Also, if you still think you need to practice identifying them, try doing the problems listed below:
Sheet 1 Practice Problems Multiplication |
1. Gets a healthy start in life
- Communities have multiple interventions to prevent children's exposure to adverse childhood experiences as well as opportunities for adults to heal and therefore become better parents.
- Communities pay adults a living wage and thereby eliminate poverty.
- All parents have access to high quality daycare
- All children have access to high quality education
2. Is supported by a healthy life style growing up and in maturity in which sources of traumatic and toxic stress are minimized.
- Communities are committed to nonviolence, do not tolerate bullying, and address any issues of around a loss of safety
3. Guards the perimeters
- Communities are able to create, reinforce, and maintain healthy social norms
- Children are oriented from early childhood around those social norms and expectations
4. Accurately recognizes various source of danger
- Communities recognize moral, social, psychological as well as physical manifestations of danger and community members are educated about these sources of danger.
5. Accurately identifies the sources of those dangers
- Communities avoid simplistic blame-and-punish strategies and instead seek out the real source of danger in every instance, usually requiring root cause analyses with multiple sources of information and input.
- Communities are aware that buried conflicts are often the seeds for later dangerous attitudes and activities and therefore places an active emphasis on conflict management methods that are effective.
6. Effectively responds to the dangers
- Community adopts problem-solving approaches and tools that are able to respond to the complexity of every situation.
- Community constantly learns from these approaches, as well as its own successes and failures in problem-solving and is able to challenge its own mental models when the approaches do not appear to be working to resolve the problems.
7. Gathers information over time
- Community values memory, keeps good records that are accessible to the future, and carefully evaluates its own responses to events.
8. Stores information over time and is able to access that information later when needed
- Because the community values memory as a source of knowledge for the future, records are fully developed, present multiple points of view, and summarize lessons learned.
9. Learns from experience and adapts to change
- Because memory is retained for previous responses - both successful and failed - the community learns from its own experience but is similarly able to mobilize adaptive responses to changed conditions instead of compulsively repeating the past.
10. Has specialists to deal with different kinds of problemd
- In every community there will be those who have special expertise in addressing complex problems.
11. Returns to normal alert status when acute danger has passed
- Responses to situations that endanger established social norms is prompt and efficient, but are ended when the problems have been assessed to be resolved.
12. Includes the entire body
- Everyone in a community must be involved, even in a minor way.
- Groups or individuals who have not been involved are likely to become a source of future problems - "people support what they have helped to create and if they haven't helped to create it, they won't support it" |
What Occurs in a Reaction Between Acetone and Water?
Acetone dissolves in water, and there is minimal chemical reaction involved. As acetone is dissolved in water, hydrogen bonds form between the molecules of water and acetone. The hydrogen bonds are what keeps the acetone dissolved in the water.
When acetone is completely dissolved in water, any sample of the solution delivers equal parts acetone and water. Sometimes, dissolving acetone in water creates the appearance of bubbles. The bubbles are likely not an indication of the chemical reaction. Bubbles may be introduced through air that is trapped in the solution when acetone is poured into the water. Some solutions bubble because the chemical reaction between ingredients generates enough heat to boil; this is not the case with acetone and water. |
Through case study inquiries, students will focus on one of three conservation topics, sharing what they’ve learned with the rest of the class.
Organize your students into small groups and introduce the three topics:
Give each group the "Investigations in energy conservation" worksheet and have them select one of the topics.
Groups will need to use their devices or computers to complete their investigations. Have them answer the questions and complete the tasks on their worksheet.
As they are finishing their investigations, encourage students to decide on the key points they’d like to share with the class.
When the groups have completed their research, gather groups that share a topic to design a presentation. They will need to decide on a maximum of five key points they want to communicate, and plan how to share them with the class.
Give each topic group a maximum of five minutes to present what they’ve learned.
In Canada, EnerGuide® labels help consumers understand the energy use of major appliances. This allows people to compare the efficiency of different makes and models of appliance.
In the past, most utility companies used electromechanical meters to measure the amount of electricity consumed by a household or business. These meters measure the energy used in kilowatt-hours and the utility bills the customer for every kilowatt-hour used. Electromechanical meters only capture the total energy consumption.
For people to make informed decisions about their use of electricity, though, they need specific and real-time information about how much they’re using.
Smart meters accurately measure a household’s energy use throughout the day and periodically transmit the data to utility companies. They can also measure the amount of power a household may produce.
Having this detailed information enables the utility to more effectively manage the supply of energy based on demand, which leads to efficiencies and cost savings. The information also creates opportunities for customers and communities to generate their own power from clean sources, such as solar panels, wind, biomass and geothermal generation, which can be sold back to the utility. |
Introducing the Greenhouse Effect Aim: To understand how the Earth is warmed and how greenhouse gases contribute to global warming. Time: 15 min Best for: Year 4-8. Links with Science. Materials: Large clear plastic sheet (available from hardware stores) Activity: Stand out in sun and talk about the weather and the sun’s rays. Ask the students what happens to the sun’s rays as they come down? (Sun is absorbed by ground, reflected by earth and atmosphere) Ask the students how then Earth is kept at the right temperature? (By the atmosphere, including greenhouse gases) Put the plastic sheet over the group and ask the students what they notice - they should feel the temperature rise. Talk about the heat being trapped inside the sheet. Compare this to greenhouse gases – when they build up they trap heat in and don’t let it escape. Nearly everything we do produces greenhouse gases (like driving cars, burning coal for electricity, methane etc), which help build up the layer. Talk about ways to produce electricity without producing greenhouse gases - solar, wind, hydro, etc. Curriculum links Science Year Content Description 4 Earth’s surface changes over time as a result of natural processes and human activity (ACSSU075) 6 Energy from a variety of sources can be used to generate electricity (ACSSU219) 7 Some of Earth’s resources are renewable, but others are non-renewable (ACSSU116) 8 Energy appears in different forms including movement (kinetic energy), heat and potential energy, and causes change within systems (ACSSU155) Note 1: the curriculum links listed here are the ones most closely related to the lesson, but the list is not exhaustive and there may be links to other learning areas, strands and year levels which are also fulfilled by this lesson idea. Note 2: For Cross-curriculum priorities and General capabilities, check the Content Descriptions at ACARA. |
Augustus Altar of Peace
The ancient Romans were instrumental in building monuments to great victories in battle.
But they also built monuments for their leaders and emperors. One such monument is the Augustus’ Altar of Peace, also known as Ara Pacis in Latin.
This particular altar was constructed for the period of peace that Emperor Augustus brought to the Roman Empire.
Why construct the Augustus’ Altar of Peace?
Augustus’ rise of power from 27 B.C.E., ancient Rome entered into the period known as Pax Romana or simply the Roman peace.
With only a few instances of disturbances during the next two centuries, ancient Rome was peaceful. During his time as emperor Augustus worried about how he was viewed by the public.
He did not want to be seen as a tyrant or authoritarian emperor. Augustus knew from his adoptive father, Julius Caesar, that a person could take control with absolute power as long as the actions were not obvious.
Augustus led by example of how to be a good Roman citizen and portrayed himself as a protector of the Roman Republic. The Augustus’ Altar of Peace was a tribute to this period of peace in ancient Rome.
Augustus’ Altar of Peace
The altar was constructed between 13 B.C.E. to 9 B.C.E. It is located within the Campus Martius, known as the Field of Mars. The altar was constructed to celebrate his return from Spain and Gaul.
The altar is quite remarkable in design and in construction. Altars in ancient Rome were built outside because sacrifices were not made inside temples. The entire altar is built from Italian Luna marble.
The three-meter altar is set upon a pedestal that is seven meters tall within an open-air structure with four walls that are over 11 meters tall. The pedestal is decorated with Vestal Virgins, sacrificial animals, and priests.
The interior walls surrounding the Augustus’ Altar of Peace have engravings of fruit, flowers draped over the necks of ox heads.
The exterior walls have designs that include mythical figures such as a she-wolf nursing Romulus and Remus as well as a female with two children that represent Mother Earth. Another wall includes the designs of senators, priests, families, and magistrates.
There is also a wall that depicts Augustus and his Imperial family. Walls also show people talking with each other, including families with children that actually look bored with the adult conversations taking place between the figures carved on the walls.
Discovering Augustus’ Altar of Peace
Pieces of the altar were discovered around 1568, 1859, and 1903 C.E. numerous fragments were also found within several museums around Europe. During the 1930s under the Mussolini rule, the altar was reassembled piece by piece. Today, Augustus’ Altar of Peace now resides within the Museum of the Ara Pacis in Rome.
Facts about Augustus’ Altar of Peace
- Augustus was emperor from 27 B.C.E. until his death in 14 C.E.
- During his reign, Augustus wanted the public to view him as a model Roman citizen and not a tyrant or authoritative leader.
- Augustus’ Altar of Peace was constructed from 13 B.C.E. to 9 B.C.E.
- The altar was to memorialize a period of peace in ancient Rome known as the Pax Romana.
- The altar was built from Italian Luna marble and was located within the Campus Martius or Field of Mars.
- Altars in ancient Rome were constructed outside to accommodate sacrifices to their gods.
- The walls of the altar are designed with several people, including children, senators, magistrates, and one wall shows a she-wolf feeding Romulus and Remus.
- The altar was discovered in 1538 C.E., and pieces were later found in several museums around Europe. Today, the reassembled altar is located in the Museum of the Ara Pacis.
What did you learn?
- What type of marble was used for constructing Augustus’ Altar of Peace?
Italian Luna marble
- Where was the original location of Augustus’ Altar of Peace?
Campus Martius also is known as the Field of Mars
- What is the time period known as during the rule of Augustus in ancient Rome?
Pax Romana or Roman Peace
- What mythical figure is portrayed on one of the exterior walls?
A she-wolf with Romulus and Remus
- What type of person did Augustus want the public to view him as while he was emperor of Rome?
A model Roman citizen |
The practice of placemaking can help communities achieve the ideals of the complete communities philosophy. Complete communities, among other core values, seek to be inclusive, active, and sustainable. Creating vibrant public places can play a vital role in bringing these ideals to fruition in our own communities.
Great public spaces encourage inclusive and active communities because they provide tangible features that citizens can be proud of. These are the places that citizens will choose to gather and interact with one another. Interactions amongst citizens in public spaces create social networks, promote a culture of involvement, and foster a sense of community character.
Economic and environmental sustainability can also be achieved through placemaking. Creating, maintaining, and improving public places are good practices in economic development. Businesses are attracted to and thrive in areas that have vital centers of community.
Placemaking encourages citizens to improve their environments, especially those they share with their neighbors. Many public spaces also serve as natural oases in urban settings. Open spaces provide psychological value to citizens and ecological benefits to the environment.
Creating vibrant communities where people not only can, but want to live, work, play and interact can be a difficult but exciting task. It is about creating and implementing a shared community vision—something that begins at the community level and involves local residents and stakeholders. While trained professionals can facilitate the process, community members must cooperatively identify the greatest assets, aspirations, and collective vision for their community. |
Our tamaiti is now becoming much more aware that they’re a unique individual.
They will be working out friendships and how relationships work. Their awareness increases about other people’s feelings and perspectives, which helps their developing sense of empathy.
They’re not always good at sharing yet, but they’re learning to.
They are still developing their ability to regulate their emotions.
They’ll be curious about gender — their own and others’ — because they now understand that boys and girls are different.
They can follow simple instructions and feel proud of their ability to complete tasks.
‘I can do it’ is still a favourite phrase and will be used regularly, especially when it comes to getting dressed, washing hands and brushing teeth.
Help them to feel special by encouraging their achievements and acknowledging what they can do, and also when they’re trying hard.
Encourage and help them to share. Ask them about their ideas for making things fair for everyone.
Talk with them about your own feelings — the frustrating ones and the happy ones.
Read stories about kids who are learning to share, join in a group or deal with upsets.
Understand that it’s quite natural for children of the same age to be curious about each other’s bodies, especially those of the opposite gender.
Calmly accept their natural curiosity. Adult reactions will influence whether tamariki feel this is something odd, naughty or shameful, or just another normal learning experience.
Give simple, clear answers to their questions.
Encourage self-care practices with patience and consistency as they learn to look after themselves well. They’ll benefit from developing skills such as going to the toilet independently, hand-washing, using a tissue, brushing their teeth and dressing themselves.
If you are concerned about how well they do a task, say something like, ‘You brush your teeth first and then I’ll check them for you when you’re finished.’
Remember to work on tasks together and to offer tamariki simple choices.
Our tamaiti is now developing more control of their body and more strength in their muscles. They may also go through a growth spurt.
Their skills will continue to consolidate through repeated practice while they play.
They’re also likely to show more confidence, having moved from a wobbly toddler to a young child with less fat and more muscle.
New large motor skills will usually develop during this time, including:
more accuracy throwing and catching a ball
walking on tip toe
steering a balance bike
pedalling and steering a tricycle
walking up and down stairs one foot after the other.
Their fine motor skills also become more controlled, so our tamaiti will be more capable and confident when using scissors, paint brushes, building with blocks, and using pencils, pens or crayons. They can also copy vertical lines and circles.
They can likely prepare and serve some of their own food and drink.
Vision and hearing checks are still important.
Keep providing tamaiti with plenty of time outside to play and explore in safe environments.
Visit parks, beaches, playgrounds and other open spaces where they can run, jump, climb, dig, balance, slide and swing.
Have lots of opportunities for ball play — throwing, kicking, aiming and catching.
Check where they’re playing for possible dangers, both inside the house and outdoors in gardens, garages and sheds.
Be especially careful with road and driveway safety. Remind other whānau members and visitors about this too.
Think of ways to provide vigorous play opportunities when it’s not possible to be outside. For example, make an indoor obstacle course or start a game of balloon volleyball.
Give plenty of opportunities to use paper, scissors and drawing tools like pencils, crayons, chalk and felt tips.
Talk to them about where it’s okay to draw and what is okay to cut.
Have paint brushes, glue, scissors and collage materials available for them. Regularly using the small muscles in their hands and fingers consolidates their fine motor skills.
Continue to keep appointments for Well Child/Tamariki Ora health checks.
Although language ability varies, by the age of 3 many tamaiti will be using 4-word sentences.
Their vocabulary increases depending on the amount and quality of the language they hear, and the conversations they have.
People familiar to them can understand their speech most of the time.
They can recite rhymes and songs and tell stories that may mix up reality and make-believe.
They’ll ask lots of questions.
They’ll enjoy playing with language, repeating phrases, making up rhymes and making up silly words.
They’ll use language to enter a fantasy world.
Singing songs is another fun way for them to use language.
By the time they’re 5 they’ll be understood by most people.
However, they may still stumble over some words. Sounds such as ‘s’ and ‘th’ could still be developing, but this doesn’t always mean a long-term problem. With growth and practice they should master all the sounds in the language of their whānau.
They’re on the way to using plurals accurately.
Picture books remain popular and they’re likely to have their favourites, which they may want to hear over and over again.
Their ability to concentrate is strengthened through book sharing.
Have conversations about what’s going on around them, the people they meet and what they’re doing.
Tell stories and encourage them to join in the telling.
Model accurate grammar and plurals.
Join in games and add in new ideas to conversations.
Listen patiently, giving them time to say what they’re trying to get out.
Have fun reading books together, and talk about the story and the characters in it.
Add extra words to extend vocabulary.
Have fun with words and sounds. Talk about words that rhyme or start with the same sound.
Look for ways to increase the number of words they use, especially about new experiences they are having.
Books have many uses. Stories can entertain, teach tamariki about the world, calm their fears, show families going through similar events, comfort them and make them laugh.
When reading together, check in with them by asking questions like, ‘What do you think that word means?’ ‘What do you think is going to happen next?’
Make your own books with them by writing the story together.
Point out letters and words everywhere, such as traffic signs, street names and brand names.
Libraries are free and books are readily available. Sitting and reading with a child can be one of life’s joys — for both of you.
By age 3, tamariki are better at recognising and expressing their emotions.
Their behaviour is a window into their world, and shows how they’re coping with the day-to-day realities of their lives.
They don’t yet have all the skills to solve problems and get what they need by reasonable and acceptable means, so they’ll need help when things go wrong for them.
For example, they might be using the toilet independently or they may still need help. How adults help with this learning can impact greatly on the level of progress they make.
Changes in their environment can have an impact on their toileting progress and may even see them regressing to wetting and soiling themselves. A new sibling arriving, a new home or starting at an early childhood education centre can all upset their toileting progress.
Sometimes a child finds themself in a new home with a new family caring for them. This is likely the result of some crisis and may see them suffering from grief, loss or trauma. They may be obviously upset, angry, unhappy or withdrawn, or seemingly OK, but struggling under the surface.
Build a safe and secure world for tamariki, even if that wasn’t what dad and mum experienced growing up.
Be warm and caring towards them, as loving relationships are the foundation for their wellbeing and development. If a child’s trust is shaken, their behaviour may be negatively affected.
Understand that sometimes they will need extra support and stability, especially if they’ve experienced trauma or are upset and their behaviour is difficult. Even when it’s hard to give, they need love and kindness, not punishment.
Revisit SKIP’s ‘ngā tohu whānau’ (the 6 principles of effective discipline’). These will help give tamariki the structure and discipline they need to grow into happy and capable adults.
Help them to learn and use language to say how they’re feeling. This way they’re less likely to ‘act out’ with challenging behaviour, or bottle up their emotions when there are disputes.
Whatever a child’s circumstances, those caring for them can provide a healthy, stable and positive environment by using ngā tohu whānau to guide them. It can take a great deal of effort and perseverance by the caregiver, but it is absolutely worth it.
Right from the start, this resource has emphasised the importance of play. Play is a child’s work and is how they get their main learning opportunities. Humans are no different to other baby mammals like kittens, puppies or cubs: play prepares them for adult life.
At ages 3–5 the play activities can seem more like miniature adult activities than previously, and a child’s sense of humour is developing as they are learning about how things ‘ought’ to be.
Their play will likely include pretend games with imaginary friends. Through their imagination they can create someone or something special just for themselves.
By age 4, pretend play may become quite sophisticated. Upsetting events or exposure to inappropriate material can lead to confusion or fears — real or imagined.
Play also provides ideal opportunities for learning te reo Māori.
Tamariki learn best when they’re relaxed and having fun.
Be their child’s first and most important playmates. Turn anything into an opportunity to play. For example, getting dressed, household jobs, cooking or shopping are all opportunities to have fun together and watch them learn and grow.
Avoid the ‘it’s just quicker to do it myself’ thinking and instead give tamariki the opportunity to help with jobs at home.
Be prepared to laugh along with them and make up silly rhymes and stories together.
Respond thoughtfully to their pretend play. It can be a source of entertainment and amusement, or it may cause concern.
Decide whether they need someone to ‘play along’ with in an imaginative game, or if they need comfort and reassurance.
Remember that in most cases imaginative play will be influenced by all the things they see and hear in their daily lives.
Be aware of what they may be watching on television or accessing on the internet.
Understand that fantasy play with imaginary friends can be their way of experimenting with different situations and feelings. It can give a glimpse into their inner thoughts and wishes.
Whānau can encourage the use of te reo through play. Keep it fun and lively. |
Though there are many kinds of springs, helical springs are the most common, and their application is widespread. From machinery and consumer products to industrial equipment and transportation—anything with a machine will likely have a spring inside it. Springs are a valued device because they can store mechanical energy. Varying types have been in use since the beginning of recorded time, from simple snare traps to the bow and arrow to leaf springs, some argue that the use of springs dates back to the Stone Age. Yet, it was not until 1763 that the invention of the helical spring occurred. A near century later, 1857, the first steel coil spring was produced. From that point forward, helical springs played an important role in the Industrial Revolution and in industries today.
What is a Helical Spring?
The simple answer is that helical springs are elastic coils. Thus, helical springs are also referred to as coil springs. They are formed by a tightly wound helical coiled wire into a cylindrical spring. Their unique design can absorb, eject, or maintain a force or energy between surfaces. Once the energy has been released, the elastic coil returns to its original helix-shaped form. Helical springs functionality can be easily highlighted by the sheer amount of applications that the spring has in all areas of modern life.
Types of Helical Springs
There are different kinds of helical springs. The easiest way to recognize one from the other is to understand the application. In other words, what kind of load is the spring designed to carry? The three main varieties of helical springs are compression, tension or extension, and torsion. As their names imply, the specific design of the springs represents their mechanical application and how their potential energy is stored.
Compression springs are the most common helical spring on the market. They are the open-coiled springs designed to resist force when their axis is compressed. They come in numerous shapes, including conical, hourglass, or barrel. The compression acts as a buffer to absorb the energy of a particular load. They are powerful, durable springs that are placed in round holes, over rods or shafts—anywhere any resistance to linear compression is needed. Common compression springs have diverse applications in many industrial sectors. You will find them in ballpoint pens, mattresses, sofas, couches, valves, electrical switches, button operated devices, vehicle suspensions, and medical devices.
Tension springs, or extension springs, are those tightly wound coiled springs with loops or hooks at either end. This allows the spring to be attached to separate components. Mechanical energy is expended when an outside force creates tension and pulls the spring. The further a device is extended the greater energy is needed to return components back to its resting or neutral position. Tension springs are used across many industry sectors, from energy and agriculture to aerospace and rail. Common applications for tension springs include trampolines, automotive interiors and exteriors, various farm equipment, garage doors, and medical devices like stretchers and surgical lights.
Finally, torsion springs store energy similarly to compression springs. However, they store their energy when twisted or rotated, utilizing torque force. Once the spring is twisted, the spring exerts proportional force to the amount being applied but in the opposite direction. Torsion springs are used whenever a rotational or torque force is needed. Door hinges are a prime example. Torsion springs are used in garage doors, automobile doors, industrial heavy-duty overhead doors on loading docks and warehouses, and common screen porch doors. This helical spring provides the clamping ability of a clothespin. Spiral torsion springs are used in mechanical watches. They are also found in clipboards, mousetraps, and levers and switches of all shapes and sizes.
The combination of simplicity and functionality present a multitude of uses for helical springs. Over the years, helical springs have been widely adapted for use in common household products to industrial applications. They vary in size from micro designs for medical and electronic applications to large industrial-sized foundational dampeners for bridges. Helical springs are a reliable means to store mechanical energy, and their durability and precision not only make them suitable for a wide range of products and applications but an indispensable component in the modern world.
Want to learn more about the capabilities and products James Spring & Wire has to offer? Contact us online today or give us a call at (610) 644-3450 to learn more! |
Cardiac arrhythmias are disorders associated with abnormal electrical activity of the heart. Such disorders manifest in the heart beating too fast or too slow, or might manifest in an irregular heartbeat. Arrhythmias may occur occasionally in healthy hearts but are of minor consequence. However, in other cases, arrhythmias may indicate a serious problem and lead to heart disease, stroke or sudden cardiac arrest.
Artificial Pacemaker & Implantable Cardioverter-Defibrillator
Cardiac arrhythmias can be treated with implantable medical devices that use electrical impulses to regulate the beating of the heart. Generally, two basic types of devices are distinguished: the artificial pacemaker and the implantable cardioverter-defibrillator (some devices combine defibrillation and pacing function in a single device).
Devices that correct the heart rate are traditionally called artificial pacemakers. They correct irregularities of the sinus node, the natural pacemaker tissue of the heart. Irregular activity of the sinus node might result in signals that are either too slow (sinus bradycardia) or in signals that are temporarily suspended (sinus arrest). Other irregularities might manifest in improper electrical signal transmission from the atria (the top heart chambers) to the ventricles (the bottom heart chambers). In all cases, artificial pacemakers are used to maintain an adequate heart rate.
The first implantable pacemaker (CC Professor Marko Turina, University Hospital, Zurich).
Devices that correct irregular heart rhythms (as opposed to heart rates) are called implantable cardioverter-defibrillator (ICD). They are, like pacemakers, small electrical impulse generators implanted in patients. As the name suggest, defibrillators counter the effects of fibrillation, a life-threatening event in which the heart muscle cells contract chaotically.
Pacemakers and defibrillators contain a battery, electrodes that measure the naturally occurring activity of the heart, an amplifier for these signals and an integrated circuit that computes and delivers impulse to the heart. The devices are hermetically sealed and usually made of titanium to avoid rejection by the immune system. Most commonly, the devices are placed below the fat layer of the chest wall. However, the placement may vary on a case-by-case basis. The most modern devices contain a wireless emitter that is able to send critical information to the physician. If any abnormal problems are detected, an intricate system will alert the physician at any time of the day or night. |
Draw students' attention to the key ideas of this section using means such as posters and overhead transparencies.
Discuss with students the role of dissection in learning about the human body. For example, students will use a mammalian heart to increase their knowledge of the structure of their own heart.
Begin this section with Activity 2-1: Exploring the Heart. You may want to assign the Activity Report before beginning the activity.
Assign Mini Activity: Heartbeats and Mini Activity: Word Origins.
Remind students of the important role of models in science.
Activity 2-2: Siphon Pump gives students another opportunity to use a model and provides them with a concrete example of the pumping action of the heart.
Assign Mini Activity: What's Your Cardiac Output Today?
Discuss the importance of a healthy heart in maintaining homeostasis.
Select from Journal Writing prompts, Enrichment Activity 2-1: What Makes the Heart Beat Faster?, Mini Activity: Is Pumping Hard Work?, and the Breathing Projects beginning on TE page 164.
Review the Apply Your Knowledge and the Review Questions responses.
Throughout and at the end of the section refocus students' attention to the key ideas.
Read the Prerequisites and Background Information for Activity 2-2: The Siphon Pump. |
1. Is a standard for describing the structure and presentation of information via internet.
2. To create a web to test text editor web browser FTP Client.
3. things in the body tag are things that shouldn't rendered. Body tag are the things that should be displayed.
1. heading element by base of size make the text bigger.
2. order list is which displays with number y unordered is displays with a bullet.
3. this used to display a block of quoted text in special way.
1. the greater than sign (>), the less than sign (<), and the copy right sign in your web page document you use special character called entity characters.
2. absolute hyper link - absolute location of a resource on the web. to the homepage of a web site.
3 If when you need to link web pages within your site use a relative hyper link. href will contain only the file name or file name and folder of the web page you want to display.
Web research answers
a. one type of uniture resource identifier.
b. definitely both!
c. no because some website can be harmful.
d. I didn't really look through one tutorial specifically but just looked ground. |
This is an activity to introduce and practise clothes idioms. Students complete the sentences with the missing items of clothing and later interview their classmates.
Time: 45 minutes
- To present students with clothes idioms.
- To complete the sentences in Exercise 1 with the missing items of clothing.
- To interview other classmates and write down the reasons why they agree or disagree with the statements in Exercise 1.
- Clothes do (not) make the man Worksheet, one per student.
- Write the statement Clothes don’t make the man on the board and ask students to tell their partner if they agree or disagree with it.
- Hand out a copy of Clothes do (not) make the man Worksheet and ask students to individually complete the sentences in Exercise 1.
- When the students have finished, ask them to compare in small groups and then check together as a class.
- Clarify meaning if necessary.
- In pairs, or small groups of 3, ask the students to interview each other (Exercise 2) and write down the reasons why their classmates agree or disagree with the statements they have just completed (Exercise 1).
- Once they have discussed 2 statements with their current partner(s), change the groups and continue until the students have completed the table in Exercise 2.
- When the students have finished, ask them to share the most well presented arguments they have heard.
- Ask students to choose 5 clothes idioms and think of situations in their life that could be described using those idioms, e.g. since losing my weekend job, I have had to tighten my belt; If I don’t pull my socks up, I won’t pass the exam at the end of term. |
Sixth Grade Common Core Learning StandardsRatios & Proportional Relationships
Understand ratio concepts and use ratio reasoning to solve problems.
1. Understand the concept of a ratio and use ratio language to describe a ratio relationship between two
quantities. For example, “The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2
wings there was 1 beak.” “For every vote candidate A received, candidate C received nearly three votes.”
2. Understand the concept of a unit rate a/b associated with a ratio a:b with b 0, and use rate language in the
context of a ratio relationship. For example, “This recipe has a ratio of 3 cups of flour to 4 cups of sugar, so
there is 3/4 cup of flour for each cup of sugar.” “We paid $75 for 15 hamburgers, which is a rate of $5 per
3. Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables
or equivalent ratios, tape diagrams, double number line diagrams, or equations.
a. Make tables of equivalent ratios relating quantities with whole-number measurements, find missing
values in the tables, and plot the pairs of values on the coordinate plane. Use tables to compare ratios.
b. Solve unit rate problems including those involving unit pricing and constant speed. For example, if it
took 7 hours to mow 4 lawns, then at that rate, how many lawns could be mowed in 35 hours? At what
rate were lawns being mowed?
c. Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity);
solve problems involving finding the whole, given a part and the percent.
d. Use ratio reasoning to convert measurement units; manipulate and transform units appropriately when
multiplying or dividing quantities.
Number SystemApply and extend previous understandings of multiplication and division to divide fractions by
1. Interpret and compute quotients of fractions, and solve word problems involving division of fractions by
fractions, e.g., by using visual fraction models and equations to represent the problem. For example, create a
story context for (2/3) ÷ (3/4) and use a visual fraction model to show the quotient; use the relationship
between multiplication and division to explain that (2/3) ÷ (3/4) = 8/9 because 3/4 of 8/9 is 2/3. (In general,
(a/b) ÷ (c/d) = ad/bc.) How much chocolate will each person get if 3 people share 1/2 lb of chocolate equally?
How many 3/4-cup servings are in 2/3 a cup of yogurt? How wide is a rectangular strip of land with length
3/4 mi and area 1/2 square mi?
Compute fluently with multi-digit numbers and find common factors and multiples.
2. Fluently divide multi-digit numbers using the standard algorithm.
3. Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each
4. Find the greatest common factor of two whole numbers less than or equal to 100 and the least common
multiple of two whole numbers less than or equal to 12. Use the distributive property to express a sum of two
whole numbers 1–100 with a common factor as a multiple of a sum of two whole numbers with no common
factor. For example, express 36 + 8 as 4 (9 + 2).
Apply and extend previous understandings of numbers to the system of rational numbers.
5. Understand that positive and negative numbers are used together to describe quantities having opposite
directions or values (e.g., temperature above/below zero, elevation above/below sea level, credits/debits,
positive/negative electric charge); use positive and negative numbers to represent quantities in real-world
contexts, explaining the meaning of 0 in each situation.
6. Understand a rational number as a point on the number line. Extend number line diagrams and coordinate
familiar from previous grades to represent points on the line and in the plane with negative number
a. Recognize opposite signs of numbers as indicating locations on opposite sides of 0 on the number
line; recognize that the opposite of the opposite of a number is the number itself, e.g., –(–3) = 3, and
that 0 is its own opposite.
b. Understand signs of numbers in ordered pairs as indicating locations in quadrants of the coordinate
plane; recognize that when two ordered pairs differ only by signs, the locations of the points are
related by reflections across one or both axes.
c. Find and position integers and other rational numbers on a horizontal or vertical number line
diagram; find and position pairs of integers and other rational numbers on a coordinate plane.
7. Understand ordering and absolute value of rational numbers.
a. Interpret statements of inequality as statements about the relative position of two numbers on a
number line diagram. For example, interpret –3 > –7 as a statement that –3 is located to the right of –
7 on a number line oriented from left to right.
b. Write, interpret, and explain statements of order for rational numbers in real-world contexts. For
example, write –3 °C > –7 °C to express the fact that –3 °C is warmer than –7 °C.
c. Understand the absolute value of a rational number as its distance from 0 on the number line;
interpret absolute value as magnitude for a positive or negative quantity in a real-world situation. For
example, for an account balance of –30 dollars, write |–30| = 30 to describe the size of the debt in
d. Distinguish comparisons of absolute value from statements about order. For example, recognize
that an account balance less than –30 dollars represents a debt greater than 30 dollars.
8. Solve real-world and mathematical problems by graphing points in all four quadrants of the coordinate
plane. Include use of coordinates and absolute value to find distances between points with the same first
coordinate or the same second coordinate.
Expressions & Equations
Apply and extend previous understandings of arithmetic to algebraic expressions.
1. Write and evaluate numerical expressions involving whole-number exponents.
2. Write, read, and evaluate expressions in which letters stand for numbers.
a. Write expressions that record operations with numbers and with letters standing for numbers. For
example, express the calculation “Subtract y from 5” as 5 – y.
b. Identify parts of an expression using mathematical terms (sum, term, product, factor, quotient,
coefficient); view one or more parts of an expression as a single entity. For example, describe the
expression 2 (8 + 7) as a product of two factors; view (8 + 7) as both a single entity and a sum of two
c. Evaluate expressions at specific values of their variables. Include expressions that arise from
formulas used in real-world problems. Perform arithmetic operations, including those involving
in the conventional order when there are no parentheses to specify a particular order (Order of
For example, use the formulas V = s3 and A = 6 s2 to find the volume and surface area of a cube
with sides of length s = 1/2.
3. Apply the properties of operations to generate equivalent expressions. For example, apply the
distributive property to the expression 3 (2 + x) to produce the equivalent expression 6 + 3x; apply the
distributive property to the expression 24x + 18y to produce the equivalent expression 6 (4x + 3y);
apply properties of operations to y + y + y to produce the equivalent expression 3y.
4. Identify when two expressions are equivalent (i.e., when the two expressions name the same
number regardless of which value is substituted into them). For example, the expressions y + y + y
and 3y are equivalent because they name the same number regardless of which number y stands for.
Reason about and solve one-variable equations and inequalities.
5. Understand solving an equation or inequality as a process of answering a question: which values
from a specified set, if any, make the equation or inequality true? Use substitution to determine
whether a given number in a specified set makes an equation or inequality true.
6. Use variables to represent numbers and write expressions when solving a real-world or
mathematical problem; understand that a variable can represent an unknown number, or, depending
on the purpose at hand, any number in a specified set.
7. Solve real-world and mathematical problems by writing and solving equations of the form x + p =
q and px = q for cases in which p, q and x are all nonnegative rational numbers.
8. Write an inequality of the form x > c or x < c to represent a constraint or condition in a real-world
or mathematical problem. Recognize that inequalities of the form x > c or x < c have infinitely many
solutions; represent solutions of such inequalities on number line diagrams.
Represent and analyze quantitative relationships between dependent and independent
9. Use variables to represent two quantities in a real-world problem that change in relationship to one
another; write an equation to express one quantity, thought of as the dependent variable, in terms of
the other quantity, thought of as the independent variable. Analyze the relationship between the
dependent and independent variables using graphs and tables, and relate these to the equation. For
example, in a problem involving motion at constant speed, list and graph ordered pairs of distances
and times, and write the equation d = 65t to represent the relationship between distance and time.
Solve real-world and mathematical problems involving area, surface area, and volume.
1. Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing
into rectangles or decomposing into triangles and other shapes; apply these techniques in the context
of solving real-world and mathematical problems.
2. Find the volume of a right rectangular prism with fractional edge lengths by packing it with unit
cubes of the appropriate unit fraction edge lengths, and show that the volume is the same as would be
found by multiplying the edge lengths of the prism. Apply the formulas V = l w h and V = b h to find
volumes of right rectangular prisms with fractional edge lengths in the context of solving real-world
and mathematical problems.
3. Draw polygons in the coordinate plane given coordinates for the vertices; use coordinates to find
the length of a side joining points with the same first coordinate or the same second coordinate. Apply
these techniques in the context of solving real-world and mathematical problems.
4. Represent three-dimensional figures using nets made up of rectangles and triangles, and use the
nets to find the surface area of these figures. Apply these techniques in the context of solving realworld
and mathematical problems.
Statistics & Probability
Develop understanding of statistical variability.
1. Recognize a statistical question as one that anticipates variability in the data related to the question
and accounts for it in the answers. For example, “How old am I?” is not a statistical question, but
“How old are the students in my school?” is a statistical question because one anticipates variability
in students’ ages.
2. Understand that a set of data collected to answer a statistical question has a distribution which can
be described by its center, spread, and overall shape.
3. Recognize that a measure of center for a numerical data set summarizes all of its values with a
single number, while a measure of variation describes how its values vary with a single number.
Summarize and describe distributions.
4. Display numerical data in plots on a number line, including dot plots, histograms, and box plots.
5. Summarize numerical data sets in relation to their context, such as by:
a. Reporting the number of observations.
b. Describing the nature of the attribute under investigation, including how it was measured and its
units of measurement.
c. Giving quantitative measures of center (median and/or mean) and variability (interquartile range
and/or mean absolute deviation), as well as describing any overall pattern and any striking deviations
from the overall pattern with reference to the context in which the data were gathered.
d. Relating the choice of measures of center and variability to the shape of the data distribution and
the context in which the data were gathered. |
As part of a collaboration with the USGS and CSUN, Dr. Renaud Berlemont, associate professor of Biological Sciences at CSULB, recently contributed to a research analyzing samples of ancient soil trapped in Arctic ice from roughly 33,000 years ago.
In this work, the team analyzed the soil chemistry and the bacteria that were able to survive the harsh frozen conditions of the Arctic. Among other discoveries, the team identified what remained of the plants and the bacteria, and how these microbes degraded the plant material under primitive conditions.
"We still do not understand the mechanisms that enable microbial survival and growth in permafrost(frozen soil in the arctic)," the authors said. "Nor how microbial communities respond to increasingly thermodynamically limited conditions given the closed nature of the system."
This research helps us understand how the soil was formed and preserved for so long. In addition, as the permafrost is melting due to climate change, it is essential to understand how the microbes will reactivate and degrade the remaining plant material. This could possibly increase the soil respiration and the release of CO2 in the atmosphere and thus accelerate the climate change.
Dr. Berlemont's work may also help people understand that these small organisms are affected by, and will contribute, to the climate change: "Most processes and fluxes (e.g., O2, CO2, N) in environments are driven by the many 'invisible' microbes. However, most people don't know that and focus on larger, easier to observe organisms." Berlemont said.
Explore more of Dr. Berlemont's work, including his research on microbes in the Arctic permafrost, on his faculty website. |
When it comes to the evolution of human beings, there is a lot of ground to cover. Fully modern human beings belong to the subspecies Homo Sapiens Sapiens, and evolved from the Australopithecine, (also known as archaic Homo sapiens) a subspecies from Africa that no longer exists today. However, there are still some Scientists that believe that today’s fully modern humans are also related to the subspecies Homo sapiens neanderthalensis, although there is now genetic evidence which points to the fact that the DNA of modern humans and that of Neanderthals deviated nearly 500,000 years ago, thereby making the subspecies Homo sapiens a much more direct ancestor. Modern humans, also known as Anatomically Modern Humans (AMH), evolved from the earlier Homo Sapiens nearly 200,000 years ago. Much of the differences between the different sub-species of Homo Sapiens can be seen by analyzing fossil evidence.
For example, today’s modern humans can be easily distinguished from archaic Homo sapiens based on a wide number of different anatomical/skeletal features. The skeletons of early archaic Homo sapiens included very prominent and protruding layers of bone in the brow area above the eyes, as well as skeletal features that indicated that they lived extremely physically demanding, grueling lifestyles. In contrast, today’s modern humans have all but lost the very prominent brow ridge, and modern humans also have much more noticeable chins and vertical foreheads, which contrasts with the sloped forehead and almost non-existent chins of archaic Homo Sapiens. Scientists believe that the vertical forehead of modern humans allows for larger brains, as well as providing humans with an important form of communication through brow and forehead movements (Bradshaw Foundation, 2013). In other words, the differences between modern humans differ and our ancestors extend beyond our physical appearances.
When it comes to the human Y-Chromosome, recent analysis has suggested that modern humans are much younger than scientists once believed (approximately 200,000 years old), and that contrary to the societal constructs of today (i.e. race, nationality, sex, religion, etc.), all humans are biologically related and descendants of the same early humans. Studies based off of samples taken from human beings all across the world show that the differences between humans as being so minor that they are biologically insignificant. Robert Dorit, an Assistant Professor of Biology at Yale University worked with other researchers from Harvard and the University of Chicago studying the Y chromosome and its significance. Dorit and his colleagues findings caused him to conclude that “If we all descended from a recent common ancestor, and if the history of human population is a history of movement and gene flow, then the differences between us, as socially striking as we may wish to make them, are largely irrelevant from a biologist’s standpoint” (Klein & Takahata, 2002). Furthermore, another very interesting fact that has come out of Y-chromosome analysis, is that contrary to earlier theories regarding human evolution, and due to the fact that there is such a lack of genetic variation among the humans studied, Dorit states that it is “...impossible for us to reconstruct the geographic location of our last common ancestor” (Klein & Takahata, 2002, p. 283). This is an interesting fact, given that so many commonly refer to Africa as the being the birthplace of civilization.
When it comes to the physical features that are used to distinguish fully modern Homo sapiens from other Homo Sapiens, there are of course quite a few to speak of. As mentioned previously, the skulls of modern humans differ quite greatly from other members of the Homo genus, with fully modern Homo sapiens having more pronounced chins with smaller and flatter foreheads. Another obvious key difference in anatomy is that modern humans are able to walk straight and upright, while our early ancestors were more hunched over in their physical stance. In addition to these differences, early humans are noted to be light in weight and rather short compared to modern humans. Early humans were actually very tiny, weighing an average of only 70 pounds with an average height between 3 ft. 4 in. to 4 ft. 5 in. However, the most striking and obvious differences between early Homo Sapiens and Modern Homo Sapiens is still that of the head. Modern-day humans have obviously developed much larger brains and the faces of today’s human (as well as the teeth and jaw structure) are also much smaller than that of our early ancestors. In terms of the differences in brain size, “Early transitional humans had brains that on average were about 35% larger than those of Australopithecus africanus. In fact, it is beginning with Homo habilis (1.4-1.9 million years ago) that our ancestors finally had brains that were consistently bigger than that of the great apes” (O’Neil, 1999-2012). In addition, early humans are known to have had smaller teeth that indicate that they lived off of a diet comprised of much softer foods than those of earlier human ancestors.
When it comes to analyzing the unique behavioral traits of modern humans and those of early Homo Sapiens, there are many to speak of. One of the most interesting things about human evolution has been the ability of humans to utilize our larger brains and use it for the purposes of innovation. Humans, unlike our early ancestors the Australopithecines, evolved to become far more proficient when it came to creating tools and technologies to aid in the long-term survival of the species. Some key behavioral traits that modern humans have come to embrace and heavily rely upon are language and the use of abstract thought and creativity. While there is still considerable debate as to when and where language was first invented and developed, there is evidence that points to our archaic human ancestors (who were known to live in tribes or groups of 120 individuals or more) utilizing language in order to maintain some sort of organization among the respective group. When looking at the idea of language and its inception, many point to the fact that it derived out of necessity, due to the fact that humans were beginning to cluster in ever larger groups. In fact, “The earliest members of our species appear around 500,000 years ago, and the equations would predict group sizes of 115 to 120 for them, with grooming times of around 30 to 33 percent. The conclusion seems inescapable: the appearance of our own species, Homo sapiens, was marked by the appearance of language” (Dunbar, 1998, p.112). In other words, once humans began to be able to communicate more effectively, our abilities to work together also increased as well.
In other words, language was born out of necessity and thanks to the evolution of larger brains, humans were able to think more deeply and communicate more effectively than ever before. Other examples of early human skills and inventions include the vast amount of cave paintings, pottery, tools (some showcasing their ability to create and use symbolism with engraved “art” on them), and architecture have been discovered all over the world. In addition, one of the most important human advances of all time has been the hugely important invention of agriculture, which has clearly played an enormous role in sustaining human life since it first began. The Neolithic period is known to most as the last part of what is commonly referred to as “The Stone Age”, taking place from approximately 10,200 BC and 2,000 BC. (Jurmain, et al., 2011, p. 427). This period is widely thought to have begun in what is now the West Bank in Israel, and is cited as being the era in which tools and technology became much more widespread.
The advancements in technology allowed the Neolithic to do a great deal of farming, of which they are known to have grown wheat and other grains, as well as also keeping goats, sheep, pigs, cows, and even dogs. It was also during the Neolithic era that pottery became much more practiced and prevalent in certain parts of the world (Bellwood, 2005, pgs. 49-55). The Neolithic era is also credited with being the period in which humans began creating permanent or semi-permanent settlements, leading to the creation of what we now regard as civilization. The world’s first town appeared in 9000 BC in an area known as the Levant, but that is now referred to as Jericho, which is actually located in modern-day Israel. It is quite interesting to imagine what the first settlement must have been like: chock-full of people, animals, and new ideas flourishing all around.
Given what we now know, it is clear that the advent of agriculture allowed humans to live and work together in greater numbers, and to abandon their once nomadic lifestyles. The interconnectedness of their lives thereby created civilization and society based on their respective commonalities. Soon the early human civilizations were coming together to trade goods and eventually came to rely on one another. The first examples of civilizations appeared in the Levant, which was located in what is now the West Bank in Israel. In addition to the rise of civilization in the Levant, the first settlements that were able to provide homes to thousands of people appeared around the 31st century BC in a place called Memphis. The settlement of Memphis was located where now modern-day Egypt exists, as well as the ancient city of Uruk, which is located near what would later be known as Babylon, and inside the borders of the country which we now know today as Iraq. This fact is made all the more interesting based on the high-profile of Iraq in our own media in recent years.
In closing, an anthropologist would likely define civilization as any place where a mass of people live and work together toward a collective good. Technology allowed for a much broader and more diverse future for humans, and afforded them the ability to settle down and make permanent homes for themselves. The future looked bright and these early communities began to flourish as new ideas began to be exchanged among their respective citizens.
Bellwood, P. (2005). First farmers: The origins of agricultural societies. Malden, MA: Blackwell Publishing.
Bradshaw Foundation. (2013). Homo sapiens. Retrieved from http://www.bradshawfoundation.com/origins/homo_sapiens.php
Dunbar R. (1998). Grooming, gossip, and the evolution of language. Cambridge: Harvard University Press.
Jurmain R., Kilgore L., Trevathan W. & Ciochon R.L. (2011). Introduction to physical anthropology(2011-2012 ed.). Belmont, CA: Cengage Learning.
Klein, J. & Takahata N. (2002). Where do we come from?: The molecular evidence for human descent. New York: Springer-Verlag New York, LLC.
O’Neil D. (1999-2012). Early transitional humans. Retrieved from http://anthro.palomar.edu/homo/homo_1.htm |
On the Road to Writing
Handwriting develops as children develop increased control over their bodies and a desire to communicate through mark-making. In order to eventually acquire a legible, fluent and fast handwriting style, children need to develop skills including good gross and fine motor control, recognition of pattern, a language to talk about shapes and movements, the main handwriting movements involved in the three basic letter shapes as exemplified by l, c, r.
What is the difference between gross and fine motor control?
Fine motor control is the term used to describe smaller movements, usually of the hand and fingers. Fine motor control is best developed through activities which involve small-scale movements. Gross motor control is the term used to describe the development of controlled movements of the whole body, or limbs (arms or legs). Of particular importance in relation to handwriting is the development of good posture and balance. Activities such as dance, football, use of small apparatus, cycling, gripping climbing frames and building with large-scale construction kits all develop gross motor control.
Why is pencil grip important?
A good pencil grip facilitates legibility, letter formation, speed and endurance. An efficient pencil grip is one in which the writing tool is controlled only through finger movements. This occurs when the pinky side of the hand supports the whole hand against the writing surface, allowing the other fingers to hold and move the pencil/pen/crayon. Holding a pencil or pen correctly requires strong finger and hand muscles and dexterity. A correct pencil grip will enable the writer to move the fingers, controlling the pencil or pen with efficient finger movements. The ability to hold a pencil correctly can affect a child’s attitude to learning and schoolwork, their academic achievement as well as their motor/joint development. Incorrect pencil grip is painful and causes the child’s hand and arm to fatigue quickly.
Why is good posture important?
Developing a good posture is as important as developing a good pencil grip. Over the years, children spend a great deal of time writing, and sitting in an awkward position can cause headaches, fatigue and pain in the shoulder, arm or hand. It can also slow down a child’s writing. Children will be able to sustain writing for longer if they become used to sitting comfortably.
Ideas for developing gross motor control
-Consolidate the vocabulary of movement by talking about the movements children make, such as going round and round, making curves, springing up and sliding down, making long, slow movements or quick, jumpy movements.
-Show children how to make large movements in the air with their arms, hands and shoulders. For example, fix ribbons on to the end of sticks for the children to swirl in the air. Encourage the use of both sides of the body.
-Let the children make different body shapes/actions in response to music to help them to remember the shapes.
Ideas for developing fine motor control
- Let the children make patterns using pegboards.
- Provide sewing and weaving activities.
- Involve the children in chopping and peeling in cooking activities.
- Provide woodworking tools – pliers, screwdrivers, hammers.
- Use finger rhymes, counting fingers, playing with words and sounds, etc.
- Provide small construction toys.
-Structure sand and water play to include sieving, pouring, picking up toys using tools, etc.
- Develop the pincer movement: show the children how to use tweezers to pick up and sort sequins, small beads, etc., sprinkle coloured sand, glitter, salt, etc. on pictures.
- Provide the children with paints, finger paints, etc. for making big patterns on differently shaped paper, for example, fish, balloons, kites. Talk about the patterns they make. Focus on developing the curly caterpillar, long ladder and one-armed robot.
- Encourage the children to strengthen their fingers by using clay, play dough, Plasticine, etc., for modelling. They can make letter shapes and patterns using the modelling media.
- Encourage dexterity by asking the children to cut out large letter shapes or patterns. They can use different coloured marker pens for tracing along inside the shapes. Emphasise that circles and curly caterpillars need to be traced from the top and anti-clockwise.
- Give the children thick paintbrushes and water to paint patterns on walls, fences, etc. |
Delegates from 24 countries and the European Union have agreed that the Ross Sea in Antarctica will become the world's largest marine protected area (MPA). Some 1.57m sq km (600,000 sq miles) of the Southern Ocean will gain protection from commercial fishing for 35 years.
The Marine Institute has welcomed the move to protect what's said to be the Earth's most pristine marine ecosystem. The Ross Sea, its shelf and slope only comprise 2% of the Southern Ocean but they are home to 38% of the world's Adelie penguins, 30% of the world's Antarctic petrels and around 6% of the world's population of Antarctic minke whales.
The region is important to the rest of the planet as the upwelling of nutrients from the deep waters are carried on currents around the world.The Ross Sea is also home to huge numbers of krill, a staple food for species including whales and seals. Their oil is critical for salmon farming.However there are concerns that overfishing and climate change are having significant impacts on their numbers. |
PM2.5 a name you must know…
What is PM2.5?
Particulate Matter (PM) 2.5 is a term used to describe the mixture of solid particles and liquid droplets in the air with a diameter of 2.5 micrometers or less, small enough to invade even the smallest airways.
Where does PM2.5 come from?
Outside, fine particles primarily come from car, truck, bus and off-road vehicle exhausts. Other operations that involve the burning of fuels such as wood, heating oil or coal and natural sources such as forest and grass fires. Fine particles also form from the reaction of gases or droplets in the atmosphere from sources such as power plants.
Indoor, some sources of fine particles are tobacco smoke, cooking, burning candles or oil lamps, and operating fireplaces and fuel-burning space heaters.
How can PM2.5 affect my health?
Particles in the PM2.5 size range are able to travel deeply into the respiratory tract, reaching the lungs. Exposure to fine particles can cause short-term health effects such as itchy eye, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath. Exposure to fine particles can also affect lung function and worsen medical conditions such as asthma and heart disease. Scientific studies have linked increases in daily PM2.5 exposure with increased respiratory and cardiovascular hospital admissions, emergency department visits and deaths. Studies also suggest that long term exposure to fine particulate matter may be associated with increased rates of chronic bronchitis, reduced lung function and increased mortality from lung cancer and heart disease. People with breathing and heart problems, children and the elderly may be particularly sensitive to PM2.5.
VOC another name you must know…
What is VOC?
Volatile Organic Compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short and long-term adverse health effects. Concentrations of many VOCs are consistently HIGHER indoors than outdoors.
Where does VOC come from?
Organic chemicals are widely used as ingredients in household products, such as paints, varnishes, wax, air fresheners, cleaners, disinfectants, cosmetics, hobby products, and pesticides. All of these products can release organic compounds while you are using them and sometimes even when they are stored.
How can VOC affect my health?
Exposure to VOC can cause short-term health effects such as red eyes, stuffed up nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath. In some cases, headaches, loss of coordination and nausea are also often seen.
What are you doing about improving your Indoor Air Quality? |
The phrase derives from an ancient belief that crocodiles shed tears while consuming their prey, and as such is present in many modern languages, especially in Europe where it was introduced through Latin. While crocodiles do have tear ducts, they weep to lubricate their eyes, typically when they have been out of water for a long time and their eyes begin to dry out. However, evidence suggests this could also be triggered by feeding.
Bogorad's syndrome is a condition which causes sufferers to shed tears while consuming food, so has been labelled "crocodile tears syndrome" with reference to the legend.
History and usageEdit
The expression comes from an ancient anecdote that crocodiles weep for the victims they are eating. A collection of proverbs attributed to Plutarch suggests that the phrase "crocodile tears" was well known in antiquity: comparing the crocodile's behaviour to people who desire or cause the death of someone, but then publicly lament for them. The story is given a Christian gloss in the Bibliotheca by early medieval theologian Photios. Photios uses the story to illustrate the Christian concept of repentance. The story is repeated in bestiaries such as De bestiis et aliis rebus.
In that country and by all Inde be great plenty of cockodrills, that is a manner of a long serpent, as I have said before. And in the night they dwell in the water, and on the day upon the land, in rocks and in caves. And they eat no meat in all the winter, but they lie as in a dream, as do the serpents. These serpents slay men, and they eat them weeping; and when they eat they move the over jaw, and not the nether jaw, and they have no tongue.— Curious creatures in zoology
A later writer, Edward Topsell, provided a different explanation for the tears, saying "There are not many brute beasts that can weep, but such is the nature of the crocodile that, to get a man within his danger, he will sob, sigh, and weep as though he were in extremity, but suddenly he destroyeth him." In this version, the crocodile pretends to be in distress to lure prey into a false sense of security. However, Topsell also refers to the older story that crocodiles wept during and after eating a man, repeating the standard Christian moral that this signified a kind of fake repentance like Judas weeping after betraying Jesus.
Shakespeare regularly refers to the concept. He uses both of Topsell's versions of the motive, as a trick and as fake repentance. A prominent example is in Othello, Act IV, Scene i, in which Othello convinces himself that his wife is cheating on him.
If that the earth could teem with woman's tears,
Each drop she falls would prove a crocodile.
He also refers to the version about tricking prey in Henry VI, Part 2, Act III, Scene i, in which a character refers to the faked emotions of the Duke of Gloucester: "Gloucester's show / Beguiles him, as the mournful crocodile / With sorrow, snares relenting passengers." In Antony and Cleopatra, Act II, Scene vii, Mark Antony chides Lepidus, who has asked him what crocodiles are like, with a meaningless description ending with the words "And the tears of it are wet".
Shakespeare's contemporary Edmund Spenser also refers to the story in The Faerie Queene, writing of the "cruel crafty" creature "which, in false grief, hiding his harmful guile / Doth weep full sore, and sheddeth tender tears.
In Henry Purcell's 1688 opera Dido and Aeneas, (librettist Nahum Tate), when Aeneas tells Dido he must abandon her to found Rome on the Italian Peninsula, she proclaims, "Thus on the fatal banks of Nile, / Weeps the deceitful crocodile."
Actual crocodile behaviourEdit
While crocodiles can and do generate tears, the tears are not linked to emotion. The fluid from their tear ducts functions to clean and lubricate the eye, and is most prominent and visible when crocodiles have been on dry land for a while. In the case of American crocodiles and saltwater crocodiles, the tears help rid of the excess salt that they take in with their food. According to Adam Britton,
It is difficult to trace the origin of this particular myth, but it's easy to see why it has become so popular – for an apparently remorseless creature such as a crocodile to actually weep over its victims is a memorable irony which has inspired considerable prose and created a phrase which is still popular today.
In 2006, neurologist Malcolm Shaner, assisted by Kent Vliet, a researcher at the University of Florida, decided to test the story that crocodiles or their close relatives alligators and caimans were likely to "weep" while feeding. Studying animals in Florida's St. Augustine Alligator Farm Zoological Park, Vliet recorded seven caimans feeding. He chose to use caimans rather than crocodiles because at the sanctuary they could be observed feeding on dry land. Five of the seven animals were seen "weeping", leading to the conclusion that the story describes a real phenomenon. The researchers suggest that the "weeping" may be caused by the hissing of warm air during feeding, which is forced through the sinuses, stimulating the animals' tear glands into emptying fluid into the eye.
The phrase gives its name to Bogorad's syndrome, colloquially "crocodile tears syndrome", an uncommon consequence of recovery from Bell's palsy where faulty regeneration of the facial nerve causes sufferers to shed tears while eating. Russian neuropathologist F. A. Bogorad, who first described the condition in 1926, did so in an article entitled "syndrome of the crocodile tears" (also translated as "the symptom of crocodile tears"). Bogorad argued that the tears were caused by the act of salivation.
- Arnaud Zucker (ed), Physiologos: le bestiaire des bestiaires, Jérôme Millon, 2004, p.300.
- PHOTIUS (1977). Bibliothèque. Tome VIII : Codices 257-280 (in French and Ancient Greek). Texte établi et traduit par R. Henry. Paris: Les Belles Lettres. p. 93. ISBN 978-2-251-32227-8.
- John Ashton (2009). Curious creatures in zoology. ISBN 978-1-4092-3184-4.
- Sax, Boria, The Mythical Zoo: An Encyclopedia of Animals in World Myth, Legend, and Literature, ABC-CLIO, 2001, p.70.
- Whyile, Dan. "Crocodile tears idiom origin". Theidioms.com. Retrieved 28 September 2018.
- Dido and Aeneas libretto
- Britton, Adam (n.d.). Do crocodiles cry 'crocodile tears'? Crocodilian Biology Database. Retrieved March 13, 2006 from the Crocodile Specialist Group, Crocodile Species List, FAQ.
- "No Faking It, Crocodile Tears Are Real." ScienceDaily, 4 October 2007
- Shaner, D. M. & Vliet, K. A.: "Crocodile Tears: 'And thei eten hem wepynge'", BioScience, 2007, Vol. 57, No. 7, pp.615–617
- Morais Pérez D, Dalmau Galofre J, Bernat Gili A, Ayerbe Torrero V (1990). "[Crocodile tears syndrome]". Acta Otorrinolaringol Esp (in Spanish). 41 (3): 175–7. PMID 2261223.
- McCoy, FJ; Goodman, RC (Jan 1979). "The crocodile tear syndrome". Plastic and Reconstructive Surgery. 63 (1): 58–62. doi:10.1097/00006534-197901000-00010. PMID 432324.
- F. A. Bogorad (trans Austin Seckersen), "The symptom of crocodile tears", Journal of the History of Medicine and Allied Sciences, 02/1979; 34(1):74-9.
- Lester Allen Russin, "Paroxysmal Lacrimation During Eating as a Sequal of Facial Palysyndrome of Crocodile Tears", JAMA. 1939;113(26):2310-2311.
|Look up crocodile tears in Wiktionary, the free dictionary.| |
Systematic phonics is widely regarded as the most effective way to teach children to read. It also gives children the knowledge that they need to spell. The ultimate goal is that children will transition from slowly decoding (or sounding out) a word to rapidly recognising it. At Oakfield, we follow the Letters and Sounds guidance from the Department for Education. Phonics is taught daily throughout Saplings and Key Stage 1.
At the end of Year 1, all children will be required to take the Phonics Screening Check. This will include real and fake words, and tests the children’s ability to decode and blend using the 44 sounds that they have been taught.
More information is provided at our annual Phonics Evening in January.
Blending – putting individual sounds together to make a word (eg. s-n-a-p when blended becomes snap)
Digraph – two letters used together to make one sound (eg. ck in clock, oo in book)
Grapheme – a group of letters that represent one sound
Phoneme – the smallest unit of sound in a word
Segmenting – breaking a word down into its component sounds
Split digraph - two letters that work together to make one sound but that are separated within a word (eg. the ‘ay’ in cake)
Trigraph – three letters used together to make one sound (eg. igh in light, air in hair)
You may be interested in the following resources:
This free online course designed for parents
Phonics Play – there are a variety of games to help children with decoding
Alphablocks is a BBC programme based around phonics
Demystifying Digraphs - this video explains digraphs (sounds made with two letters, such as sh, or oo). It also shares the Jolly Phonics actions that the children learn at school for these sounds |
What strategies can a teacher implement for students with mild disabilties to be successful in a general education classroom?
What is your position on the ways that students with disabilties should be taught?
When you start your paper, consider an outline that breaks the topic into sections. For example: the classroom, evaluation choices, teaching methods, curriculum options, etc.
Some possible points to include:
1. What is the physical layout of your classroom- will desk groupings work best or a single file arrangement? (Take into
consideration the nature of the disability. Some students will benefit from groupings while others will need to avoid the
distractions of a group setting).
2. Is your class layout conducive to someone with physical disabilities? (I don't know the nature of the disabled students you
are to ...
This solution includes a list of approaches for the inclusion of students with disabilities into the classroom. It provides suggestions regarding classroom design and management, evaluation, teaching methods, and curriculum.
This solution includes a list of books on the topic of students with disabilities.
This solution includes a list of education journals. |
- September 12, 2018
School and colleges teach us some awesome science fact such as magnetism, periodic table, and DNA replication. But the magic of science doesn’t end here. It is the next level of science that makes it more alluring and interesting. In no particular below are certain scientific facts that would definitely amuse you.
Top 10 Incredible Science Facts:
Science Fact 1:
It takes nearly 8 minutes 17 seconds for the light to travel from the Sun’s surface to the Earth. But takes 1 million Years to travel from Sun’s core to its surface.
This means that the light we get at this very moment was actually originated a million years ago. Fascinating right?
Science Fact 2:
Helium when cooled to absolute zero degrees it becomes an anti-gravity liquid
The gas helium known for blowing up balloons has a most interesting property when it is cooled and converted to liquid form. Helium as a liquid will have zero viscosity without loss of kinetic energy giving it the power to oppose gravity and flow upwards from a vessel.
Science Fact 3:
A drive to space will only take you an hour
The distance between the earth’s surface and space is approximately 100 kilometers. Hence at a speed of 63 mph, it would take only an hour to reach the Karman line.
Science Fact 4:
The average weight of a cloud is equal to that of 80 elephants
The volume of a cloud is higher than the weight of the same. This makes the gases fly. But it is certainly not that light and fluffy as it seems.
Science Fact 5:
The color of the sun is ‘white’
The light that is emitted from the surface of the sun is white in color. Earth’s atmosphere
Science Fact 6:
Reach the moon by folding a paper in half exactly 42 times
This is the power of exponential, folding a paper with the breadth of 0.0039 Inch for 42 times it will have a height of 439,804 kilometers. The distance between earth and moon is 384473 kilometer. Get a paper and try it now!
Science Fact 7:
Superconductors conduct electricity with zero resistance
Some special elements For example diamond will act as a superconductor at a very low temperature. This has several applications like levitating objects, lossless machines and such.
Science Fact 8:
The human mind thinks in logarithmic scale
Logarithmic scale deals with multiplication and division whereas algebraic is addition and subtraction. In simple terms, Buy 1 get 2 offer seems more attractive to the human mind than Buy 50 get 51 offer, even though in both the case we receive only one product as free.
Science Fact 9:
A hydrophobic dress doesn’t get wet
Lotus leaf has a hydrophobic compound called as the ‘Trimethylsilanol’ which has the property to oppose the water molecules. The hydrophobic dress is made using this compound as the base, thus it doesn’t get wet or dirty.
Science Fact 10:
Time dilation is the scientific proof of time travel
A list of science facts can never be completed without time travel. According to the theory of relativity, as your speed increases time slows down for you compared to those who are traveling at a slower pace than yours, this phenomenon is referred to as time dilation.
No matter what we say, science is indeed a fascinating mystery, hope that this article scraped a small portion of that mystery to you. It is time to open the door of science to young children so that they can explore the conundrum. |
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Thermogenic plants have the ability to raise their temperature above that of the surrounding air. Heat is generated in the mitochondria, as a secondary process of cellular respiration called thermogenesis. Alternative oxidase and uncoupling proteins similar to those found in mammals enable the process, which is still poorly understood.
The role of thermogenesis
Botanists are not completely sure why thermogenic plants generate large amounts of excess heat, but most agree that it has something to do with increasing pollination rates. The most widely accepted theory states that the endogenous heat helps in spreading chemicals that attract pollinators to the plant. For example, the Voodoo lily uses heat to help spread its smell of rotting meat. This smell draws in flies which begin to search for the source of the smell. As they search the entire plant for the dead carcass, they unknowingly pollinate the plant.
Other theories state that the heat may provide a heat reward for the pollinator: pollinators are drawn to the flower for its warmth. This theory has less support because most thermogenic plants are found in tropical climates.
Yet another theory is that the heat helps protect against frost damage, allowing the plant to germinate and sprout earlier than otherwise. For example, the skunk cabbage generates heat, which allows it to melt its way through a layer of snow in early spring. The heat, however, is mostly used to help spread its pungent odor and attract pollinators.
Characteristics of thermogenic plants
Most thermogenic plants tend to be rather large. This is because the smaller plants do not have enough space to create a considerable amount of heat. Large plants, on the other hand, have a lot of mass to create and retain heat.
Thermogenic plants are also protogynous, meaning that the female part of the plant matures before the male part of the same plant. This reduces inbreeding considerably, as such a plant can be fertilized only by pollen from a different plant. This is why thermogenic plants release pungent odors to attract pollinating insects.
Examples of thermogenic plants
Thermogenic plants are found in a variety of families, but Araceae in particular contains many such species. Examples from this family include the eastern skunk cabbage, the dead-horse arum, the elephant yam and Philodendron selloum, also known as elephant ear. Contrary to popular belief, the western skunk cabbage, a close relative from the Araceae family, is not thermogenic. The carrion flower (Amorphophallus titanum) also uses thermogenically created water vapor to disperse its scent — that of rotting meat — above the cold air that settles over it at night in its natural habitat.
A list of thermogenic plants
- Dead horse arum lily (Helicodiceros muscivorus)
- Eastern Skunk Cabbage (Symplocarpus foetidus)
- Elephant Foot Yam (Amorphophallus paeoniifolius)
- Sacred lotus (Nelumbo nucifera)
- voodoo lily (Typhonium venosum)
- Titan Arum (Amorphophallus titanum)
- "How Plants Work". Retrieved 4 December 2012.
- Turner Photographics. "Plant of the month: Voodoo Lily". Retrieved 4 December 2012.
- "Giant Stinking Flower". Retrieved 4 December 2012.
- "Skunk Cabbage". National Wildlife Federation. Retrieved 4 December 2012.
- Seymour, Roger; Paul Schultze-Motel (1997). "Heat Producing Flowers" (PDF). Endeavor. 3. 21: 125–129. doi:10.1016/s0160-9327(97)80222-0. Retrieved 4 December 2012.
- Onda, Yoshihiko; Kato, Yoshiaki; Yukie, Abe; Ito, Takanori; Morohashi, Miyuki; Ito, Yuka; Ichikawa, Megumi; Matsukawa, Kazushige; Kakizaki, Yusuke; Koiwa, Hiroyuki; Ito, Kikukatsu (2008). "Functional Coexpression of the Mitochondrial Alternative Oxidase and Uncoupling Protein Underlies Thermoregulation in the Thermogenic Florets of Skunk Cabbage". Plant Physiology. pp. 636–645. doi:10.1104/pp.107.113563. Missing or empty |
This ncert solutions has a variety of exemplary questions like MCQ’S, Short and long answer questions, worksheets and HOTs. By studying these solutions students get elites on this topic and they can easily make their own chapter 19 biology class 11 notes to score good marks in class 11 biology examination and entrance exams.
NCERT Solutions for Class 11 Biology Chapter 19 Excretory Products
The process of eliminating all the waste products of metabolism and other non-useful materials from a body of an organism is termed as Excretion. The metabolic wastes include carbon dioxide, the excess of water molecules, nitrogenous compounds are termed as excretory products. These products are eliminated out of our body by the excretory system. The excretory system comprises different organs and it varies in different organisms.
Main components of the human excretory system
A pair of kidneys
They are dark coloured, bean-shaped organs. The size of each kidney is about 11 cm long, 3 cm thick, and 5 cm wide. Each kidney weighs about 135gm in adult female and150gm in an adult male.
A pair of ureter
They are a white coloured tube which emerges out from each kidney. They are about 26-28 cm long and its wall is made up of transitional epithelium and is surrounded by layers of muscle fibre.
A pear-shaped, muscular sac, composed of smooth and involuntary muscles known as detrusor muscles.
It is a tube-like structure that connects the urinary bladder to the urinary meatus for the elimination of urine from the body. The structure of the urethra is different in both male and female.
Subtopics of Chapter 19 Excretory Products and their Elimination
- Human Excretory System
- Urine Formation
- The function of the Tubules
- Mechanism of Concentration of the Filtrate
- Regulation of Kidney Function
- Role of other Organs in Excretion
- Disorders of the Excretory System.
NCERT solutions for class 11 biology chapter 19 excretory products and their elimination is one of the key tools to prepare biology for class 11th examination. The class 11 NCERT solutions for biology chapter 19 provided here to help students to prepare for their exams in an effective way. The NCERT class 11 biology solutions for chapter 19 Excretory Products and their Elimination is prepared by a team of expert teachers and it covers all the key concepts of the chapter.
Class 11 Biology NCERT Solutions Transport in Plants Important Questions
Q7: Match the items of column I with those of column II:
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Excretory Products and their Elimination one of the most important topics for CBSE class 12 Biology exams. It is one among the good weightage chapters, hence, students are advised to get well versed with the concepts related to this chapter by referring to these NCERT SOLUTIONS. By practising more questions from these NCERT study materials, students can score good marks in the board exam as it will provide all the basic information about the different types of questions asked, exam question paper pattern and the marking scheme.
By downloading these pdf files, students can learn other topics related to the excretory system, structure, and functions of the excretory system and its organs. These NCERT solutions are viable for free in pdf format. Those students who like to avail these study materials can either download the pdf files or prepare online by visiting our website at BYJU’S. |
How is MS diagnosed?
Information sourced from www.mssociety.org.au
When a person has symptoms that are similar to the symptoms of MS, a neurologist – a specialist who treats diseases of the brain, spinal cord and nerves – will need to collect a detailed medical history, order a range of tests, and perform a physical examination to check certain reflexes and responses. This information is then used to determine what is happening within the central nervous system, what may have happened in the past, and whether a person meets the international criteria for a diagnosis of MS. This involves excluding any other possible causes for the symptoms the person is experiencing. If the results do not meet the criteria for a definitive diagnosis of MS, a doctor may diagnose clinically isolated syndrome or they may not be able to make a definite diagnosis. For some people it takes many years to be given a diagnosis and they may need to be monitored for a while; however, for others, a diagnosis is given when they first experience symptoms. In some instances there may even be enough information for a doctor to identify a particular type of MS. It is important to remember the process is different for everyone.
International diagnostic criteria
The criteria used to diagnose MS are agreed upon by an international committee of experts. The criteria specify the evidence a doctor needs to make a diagnosis of MS. The most important detail required is evidence of lesions in different parts of the central nervous system, at different times, with no alternative explanation other than MS. The criteria are updated regularly as better technology becomes available and as researchers learn more about MS. Today, an accurate diagnosis of MS can be achieved much quicker than it was in the past.
Once diagnosed with MS, many people realise their symptoms actually started many years before. That is why medical history is important. A person’s neurologist will usually ask about
any symptoms experienced in the past. Some of the symptoms might be evidence of existing lesions and lesions in different parts of the central nervous system. People are sometimes doubtful about telling their neurologist about symptoms, particularly unusual ones like tingling sensations or dizziness. It is important to remember neurologists are specialists who understand the central nervous system and the unusual symptoms it can produce.
Magnetic resonance imaging (MRI)
MRI scans are a specific type of diagnostic imaging used to produce images of the brain
or spinal cord. On the scans, areas of damage may show up as spots known as lesions. If
there are lesions, your neurologist will examine what type of lesions they are as well as their location. More than one lesion might be evidence of lesions in other parts of the central nervous system. Different types of MRI scans can also be used to provide different types of information. Some MRI scans can show older lesions which are remyelinating, or areas where scarring has occurred at a different time.
Your neurologist may order a range of blood tests. Generally these will be to exclude other possible causes of your symptoms. MS cannot be diagnosed by a single blood test, but test results can contribute information to the diagnostic process. They can also provide important information your neurologist will need to prescribe treatments.
A lumbar puncture (sometimes called a spinal tap) is a test which involves taking a small amount of fluid from your spine using a needle. The fluid is then sent to a laboratory to test for a number of things that can help the neurologist to build a picture of what is happening inside your body. One of the things your neurologist might be looking for is oligoclonal bands, which can provide evidence of inflammation occurring in the central nervous system.
Evoked potentials (EPs) and visual evoked potentials (VEPs)
Evoked potentials are tests which measure the time it takes for messages to travel along nerve fibres to the brain. If messages are delayed, it can indicate scarring to nerves even if you are not experiencing symptoms. Visual evoked potentials (VEPs) provide information about how well messages are travelling along your optic nerve. These tests measure the time between when you are shown an image to when the message registers in the part of your brain that processes information from your eyes. VEPs are one of the more common EPs used to diagnose or monitor MS. Your doctor may order other types of EPs such as somatosensory evoked potentials, which measure messages travelling from your skin, or auditory evoked potentials, which measure messages travelling from your ears.
For more information visit www.mssociety.org.au |
By the end of the European Middle Ages, a Christianized version of Aristotelian philosophy had achieved the status of the official Western interpretation of the world and of the place of human beings in the world. According to Aristotelian scholasticism, things are made up of matter and form. Form comes from an essence or soul within all things that also joins each form inseparably with its substance. The essence of each thing also determines how it develops and interacts with other things. Scientific thinking, from the late Middle Ages through the Early Modern period, generally involved classifying and explaining things according to their innate qualities. This view of the world, with its emphasis on essences, was consistent with the idea of souls in Christian theology and with the idea that the universe is purposeful, consisting of movement toward ends created by divine design. It was also consistent with the established political order, because political inequality among people was the result of placement decreed by God according to inborn essences.
By the seventeenth century, however, new trends in scientific and philosophical thinking began to pose challenges to Aristotelianism. A growing number of thinkers saw naturalistic and mechanistic explanations of events as more accurate than vague references to essences. From a mechanistic point of view, if something moves or changes, it is because something else causes it to move or change. This kind of explanation posed a problem for religious thinkers in the seventeenth century and after. God seemed to be left out of an account of the world that attributed every event to the interaction of bodies. In addition, there seemed to be no room for human thought or awareness in the machine of the universe.
French philosopher René Descartes (1596-1650) came up with one ingenious and influential solution to the problems posed by mechanism. By carefully reflecting on his own thoughts, Descartes found that the world seemed to be divided into himself as a thinking being and the mechanistic objects outside of himself. This managed to maintain both the supernatural and the scientific mechanisms of nature by splitting them apart. The solution offered by Descartes was frequently viewed with suspicion by leaders of church and state, but there were still some radical thinkers, such as Benedict de Spinoza (1632-1677) who went even further than Descartes and discarded the supernatural altogether.
Jonathan Israel argues, in this comprehensive and detailed volume, that the naturalistic radicals did not merely exist at the fringes of Enlightenment thinking. Although repeatedly denounced by church and state officials and frequently given only covert support even by their followers, the radicals played a central part in the creation of a modern view of the world. The radicals made substantial contributions both to the naturalistic perspective of modern science and to secular, democratizing trends in politics.
Earlier studies of the Enlightenment have frequently approached the period as a matter of national politics. Insofar as these studies have understood the Enlightenment as a European occurrence, they have portrayed it as the projection of a single nation’s influence. Those who place France at the center of the events of the time have seen Europe revolving around the writings of the philosophes from Charles de Montesquieu (1689-1755) to Jean-Jacques Rousseau (1712-1788). Those in the English school have argued that the empiricism and materialistic philosophies of John Locke (1632-1704), Sir Isaac Newton (1642-1727), and their colleagues established the current of the era. Israel does acknowledge the importance of French thinkers, although he also maintains that the development of the French Enlightenment was hampered by the hostility of the court of King Louis XIV (ruled 1643-1715). Israel also recognizes that English thinking was widely influential, particularly during the “Anglomania,” the fashion for English ideas and styles that swept through European intellectual life in the 1730’s and 1740’s. However, he sees the Enlightenment as a continental phenomenon, a set of challenges to received views and social hierarchies that arose in all parts of Europe and took varied forms in response to varied conditions.
Insofar as Israel gives priority to any country in setting the pace of the times, he gives it to the Netherlands. Some readers may feel that this is simply the author’s professional bias. He specializes in Early Modern Dutch history and the academic tendency to see one’s own field as the...
(The entire section is 1869 words.) |
A marriage between 3-D printer plastic and a versatile material for detecting and storing gases could lead to inexpensive sensors and fuel cell batteries alike, suggests new research from the National Institute of Standards and Technology (NIST).
The material is called a metal-organic framework, or MOF—perhaps not as familiar a substance as plastic, but one that may prove as broadly useful. They are easy to make, cost little, and some of them are good at picking out a particular gas from the air.
NIST sensor scientists use puppets to demonstrate metal-organic frameworks (MOFs) and their ability to selectively capture specific substances.
Seen on a microscopic level, MOFs look like buildings under construction—think of steel girders with space between them. A particular MOF talent is to allow fluids to flow through their spaces while their girders attract some specific part of the fluid and hold onto it as the rest of the fluid flows past. MOFs are already promising candidates for refining petroleum and other hydrocarbons.
MOFs have caught the attention of a team of scientists from NIST and American University because they also might be good as the basis for inexpensive sensing technology. For example, certain MOFs are good at filtering out methane or carbon dioxide, both of which are greenhouse gases. The big problem is that newly made MOFs are tiny particles that in bulk have the consistency of dust. And it’s hard to build a usable sensor from a material that slips through your fingers.
To address this problem, the team decided to try mixing MOFs into the plastic that is used in 3-D printers. Not only would the printer mold the plastic into any shape the team desired, but the plastic itself is permeable enough to allow gases to pass right through it, where the MOFs could snag the specific gas molecules the team wants to detect. The question was, would the MOFs work in the mix?
The team’s new research paper shows the idea has promise not only for sensing but for other applications as well. It demonstrates that the MOFs and the plastic get along well; for example, the MOFs don’t settle to the bottom of the plastic when it’s melted, but stay evenly distributed in the mixture. The team then moved on to mix in a specific MOF that’s good at capturing hydrogen gas and conducted testing to see how well the solidified mixture could store hydrogen.
“The auto industry is still looking for an inexpensive, lightweight way to store fuel in hydrogen-powered cars,” said NIST sensor scientist Zeeshan Ahmed. “We’re hoping that MOFs in plastic might form the basis of the fuel tank.”
The paper also shows that when exposed to hydrogen gas, the solid mix retains more than 50 times more hydrogen than plastic alone, indicating the MOFs are still functioning effectively while inside the plastic. These are promising results, but not yet good enough for a fuel cell.
Ahmed said his team members are optimistic the idea can be improved enough to be practical. They have already built on their initial research in a second, forthcoming paper, which explores how well two other MOFs can absorb nitrogen gas as well as hydrogen, and also shows how to make the MOF-plastic mixtures immune to the degrading effects of humidity. The team is now pursuing collaborations with other NIST research groups to develop MOF-based sensors.
“The goal is to find a storage method that can hold 4.5 percent hydrogen by weight, and we’ve got a bit less than one percent now,” he said. “But from a materials perspective, we don’t need to make that dramatic an improvement to reach the goal. So we see the glass—or the plastic—as half full already.”
Paper: M.C. Kreider, M. Sefa, J.A. Fedchak, J. Scherschligt, M. Bible, B. Natarajan, N.N. Klimov, A.B. Miller, Z. Ahmed and M.R. Hartings. Toward 3D printed hydrogen storage materials made with ABS‐MOF composites. Polymers for Advanced Technologies. Published online 19 October 2017. DOI: 10.1002/pat.4197 |
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The littoral fringe ecosystem is as much a part of Hawaii’s shorelines as our popular beaches and reefs. The Aquarium wants to emphasize the important link between land and sea by drawing attention to this often overlooked native environment. Healthy shores and healthy reefs are a part of Hawaii’s heritage. Just as plants of the uplands protect the watershed with a cloak of vegetation, coastal plants secure the dunes and slow shoreline erosion. And, many coastal plants serve traditional uses and hold cultural significance in Hawai‘i and throughout the Pacific. Some plants, like the naupaka-kahakai (Scaevola sericea) are indigenous – found naturally in Hawai‘i as well as elsewhere. Others, like the ‘ohai (Sesbania tomentosa) are endemic – unique species found only in Hawai‘i. While others, like the kukui (Aleurites moluccana), were brought on canoes by early Polynesian settlers. These plants aren’t considered native, they are very culturally important species, that allowed early settlers to survive on remote islands with unfamiliar vegetation.
Sadly, human activities have altered or destroyed the natural profile and vegetation along much of Hawaii’s shores. Some shoreline developments and homes are built on the shore rather than behind it; landscaping often uses exotic ornamentals rather than adapted native plants. On less developed shorelines, recreational activities like, camping, and even hiking on the dunes, break the protective cover of vegetation causing dunes to erode, and allowing aggressive weeds crowd out remaining native species.
Waikīkī once had a different profile and vegetation than we see today. The Waikīkī Aquarium’s Coastal Gardens provide a glimpse of the diversity of this important native habitat, fascinating plants and their adaptations. The Aquarium has expanded its plantings and helped restore a bit of Waikiki’s natural lei of native coastal plants. More than twenty native plant species are currently established in the Aquarium’s gardens.
The endemic plant ‘ākia, is a sprawling shrub that is adapted to dry, windy, coastal cliffs and shorelines. ‘Ākia, though listed as a threatened species, has become a popular ornamental plant used in gardens around Hawai‘i, and at Waikīkī Aquarium. Traditionally, the bark from the roots and stems of ‘ākia were crushed and then thrown into small tide pools. Within a few minutes, stupefied fish floated to the surface and were harvested. The poison would dissipate, either through dilution or through time, and the remaining tidepool fish would recover from the temporary stunning.
Endemic to the Hawaiian Islands, found from Kaua‘i to Maui |
Ear infections are the number one reason that parents bring their children to the doctor—in fact, three out of four children will experience at least one ear infection before they are three years old. An ear infection, also called acute otitis media (AOM), is an inflammation of the middle ear that results when fluid builds up behind the eardrum. While anyone can get an ear infection, they are much more common in children due to their smaller anatomy and poorly developed immune systems.
Ear infections are usually caused by bacteria and typically occur after a child suffers from a sore throat or upper respiratory infection. The bacterial infection causes fluid to build up behind the eardrum, resulting in the symptoms associated with ear infections: pain in the ear, trouble sleeping, fever, fluid drainage from the ear, problems with balance, and trouble hearing. While it is very common for children to get ear infections, there are factors that can put your child more at risk. These factors include:
Children between the ages of six months and two years are at the highest risk of developing ear infections. This is largely due to the shape of their Eustachian tubes—at this age, they have a decreased ability to drain any fluid that accumulates due to bacterial infection.
- Air quality
Children exposed to tobacco smoke or air pollution have an increased risk of developing middle ear infections.
- Seasonal factors
Children are more likely to develop ear infections during the fall and winter, when influenza and colds are common. Children with allergies may also have problems with ear infections during times when there are high pollen counts.
- Child care
Children that are cared for in group child care settings are much more likely to catch the common cold or other infections, which also increases their risk of suffering from an ear infection.
If your child appears to be suffering from possible ear infection symptoms, consider seeking treatment from your pediatrician. If you would like to learn more about the causes and treatments of acute otitis media, contact the professionals at Sunrise Children’s Hospital at (702) 233-5437. |
Hop on a laptop, click “download” on a book, and you’ve just directed nimble fingers of electricity to painstakingly transcribe every letter of that book. These fingers of electricity don’t write each letter like we do—on paper, in an alphabet of loops and lines. Rather, these fingers write each letter on eight switches, in a kind of braille alphabet called ASCII.
If the first letter of the book is “A”, these fingers start the transcription by flicking switches to “off, on, off, off, off, off, off, on”. A fraction of a second later, these nimble fingers of electricity will have flicked a few million switches. In doing so, they will have made a real, physical, ASCII copy of Fifty Shades of Grey materialise right underneath your hands.
If the laptop you’re on has a solid-state hard drive, there are more fingers of electricity flicking switches for you then there are real fingers on the planet. And yet somehow, you manage to effortlessly choreograph hundreds of billions of fingers of electricity to flick exactly the switches you want switched, without understanding anything of what you’re actually doing at all. You just point and click.
This is possible because some people designed you an intuitive user interface that makes choosing exactly the right dance of electricity easy. But the people who designed this user interface don’t understand this intricate dance of electricity either. Rather, they understand another “user interface” that is slightly more fundamental: a high-level programming language. If you keep digging, it continues like a Russian doll. Peer behind one neat mental picture and what you find underneath is another neat mental picture that is just a little bit more fundamental.
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We can pull apart these Russian dolls/mental pictures until we get to the baby doll/base mental picture. Here, we physicists try to draw a neat picture of how electricity works for the people who design electronic components. For instance, for the people who design switches that can be flicked by electricity.
The picture we have of how electricity works is something like this. Electricity is the aggregate flow of huge quantities of electrons. And just like the way ordinary objects move is dependent on what the gravity of a planet is, the way electrons move is dependent on what the electric fields in a material are. And every material has its own characteristic electric fields that are intrinsic to it. So from an electron’s point of view, a different material is like a different planet. The rules of how to move change.
The basic ploy of an electronic component designer is fairly simple. By making a component out of lumps of different materials melded together, she can ensure the electric fields are different in different parts of the component. Now, melding different materials also creates additional electric fields, but these are predictable and so can be part of her plan. That is, her plan to manipulate how electricity flows in a component, by manipulating the rules that dictate how electrons move.
But in addition to the predictable electric fields the component designer plans, there are also electric fields that cannot be predicted. And at room temperature, no matter how perfectly pure a material, these random electric fields are inevitable. So the electrons in the component are always subject to both predictable and random rules. And our picture of how electricity works depends on which rules dominate.
If the electronic component is less than about 20 or so atoms long, the electrons’ movement is dominated by the predictable rules. This means that, roughly, all electrons move the same. So in order to figure out the aggregate flow of all electrons, we only need to calculate how one electron moves. If the electronic component is larger than about 600 atoms long, the electrons’ movement is dominated by the random rules. This means the aggregate movement of electrons at every point is similarly random. Except, that is, for an easily calculated, small distortion from randomness due to the local predictable rules.
But if the component is between these sizes, the electrons’ movement is neither dominated by the predictable rules nor by the random rules. Here, we don’t have an elegant picture. Instead, we get a supercomputer, we teach it to follow both the predictable and the random rules, and we tell it to simulate the paths of a few million electrons. Then, we tally these up, to get a prediction of the aggregate flow of electrons.
Unfortunately, there are many people who have the awkward job of designing components of this intermediate size, including our friends who design switches that can be flicked by electricity. So in my research, I’ve tailor-made a new kind of “partial randomness” that can be strongly distorted by the non-random part of the electrons’ movement. My hope is that this will be able to greatly simplify our picture of electricity at this intermediate scale. Now, can I finish this piece by telling you what kind of fancy new component someone might design with a much neater picture? I can’t. And that’s the most exciting part. |
What steps can parents take to improve sibling relationships?
All siblings are bound to fight, tease and tattle on one another at some point. However, you can take active steps to encourage healthy sibling relationships. Consider these tips:
- Respect each child's unique needs. Treating your children uniformly isn't always practical — and the harder you try, the more your children might look for signs of unfairness. Instead, focus on meeting each child's unique needs. For example, instead of buying both of your children the same gifts to avoid conflict, consider buying them different gifts that reflect their individual interests. Instead of signing up all of your children for soccer or piano lessons, ask for their individual input.
- Avoid comparisons. Comparing your children's abilities can cause them to feel hurt and insecure. While it's natural to notice the differences between children, avoid discussing them in front of the kids. When praising one of your children, stick to describing his or her action or accomplishment — rather than comparing it to how his or her sibling does it.
- Set the ground rules. Make sure your children understand what you consider acceptable and unacceptable behavior when it comes to interacting with each other, as well as the consequences of misbehavior.
- Don't get involved in battles. Encourage your children to settle their own differences. Discourage tattling. While you might need to help younger children resolve disputes, you can still refrain from taking sides. When you need to discipline your children, avoid doing so in front of others — which can cause shame and embarrassment. When possible, take your child aside to discuss his or her behavior. Also, avoid using nicknames for your children that might perpetuate sibling rivalry or repeatedly blaming one child for sibling disputes.
- Anticipate problems. If your children can't resolve a disagreement by themselves or routinely fight over the same things, consider helping them devise a solution. For example, if you have young children who have trouble sharing, encourage them to each play with their own toys or plan activities that don't require much cooperation — such as listening to music or playing hide and seek. If your children regularly battle over use of the television, shared gaming systems or other gadgets, help them create a weekly schedule. Explain the consequences of not following the schedule.
- Listen to your children. Being a sibling can be frustrating. Allow your children to vent their negative feelings about each other. Respond by acknowledging their feelings. If you have siblings, share stories of your own childhood conflicts. Consider holding regular family meetings to give your children a chance to talk about and work out sibling issues.
- Encourage good behavior. When you see your children playing well together or working as a team, be sure to compliment them. A little praise can go a long way.
- Show your love. Spend time alone with each of your children. Do special activities with each of your children that reflect their interests. Remind your children that they're loved, you're there for them and they can talk about anything with you.
Do twins or other multiples have special sibling issues?
Sibling rivalry often isn't an issue for multiples. While twins or other multiples might compete against each other, the children typically also depend on each other and develop close relationships early on. However, they might have problems maintaining their individuality. Twins are often treated as a unit, rather than two children who have unique personalities. It can be tempting to dress them alike and give them the same toys. If you have multiples, pay attention to their different needs and try to foster individuality.
Other children in a family with multiples might feel left out or jealous since they're not part of this unique relationship and multiples often need and attract lots of attention. If you have multiples and one or more other children, be sure to spend plenty of special one-on-one time with each of your kids. Also, encourage your multiples to play separately with other children. For example, arrange a play date for one of your twins while the other twin plays with a sibling. Your multiples might resist separation, but being able to be apart is a skill your children will benefit from as they get older.
Remember, all siblings fight or argue. Sibling rivalry is normal. However, by treating your children as individuals, listening to them and giving them opportunities to resolve their own problems, you'll lay the groundwork for solid sibling relationships.
Feb. 23, 2012
See more In-depth
- Sibling relationships. American Academy of Pediatrics. http://patiented.aap.org/content.aspx?aid=5019. Accessed July 7, 2011.
- Shelov SP, et al. Caring for Your Baby and Young Child: Birth to Age 5. New York, N.Y.: Bantam Books; 2009:35.
- Berkowitz CD. Berkowitz's Pediatrics: A Primary Care Approach. 3rd ed. Washington, D.C.: American Academy of Pediatrics; 2008:179.
- Greydanus DE, et al. Caring for Your Teenager. New York, N.Y.: Bantam Books; 2003:85.
- Faber A, et al. Siblings Without Rivalry. New York, N.Y.: HarperCollins; 2004:1. |
Joseph Lister (18271912). On the Antiseptic Principle of the Practice of Surgery. The Harvard Classics. 190914.
JOSEPH LISTER was born at Upton, Essex, England, in 1827, and received his general education at the University of London. After graduation he studied medicine in London and Edinburgh, and became lecturer in surgery at the University in the latter city. Later he was professor of surgery at Glasgow, at Edinburgh, and at Kings College Hospital, London, and surgeon to Queen Victoria. He was made a baronet in 1883; retired from teaching in 1893; and was raised to the peerage in 1897, with the title of Baron Lister. He died in 1912.
Even before the work of Pasteur on fermentation and putrefaction, Lister had been convinced of the importance of scrupulous cleanliness and the usefulness of deodorants in the operating room; and when, through Pasteurs researches, he realized that the formation of pus was due to bacteria, he proceeded to develop his antiseptic surgical methods. The immediate success of the new treatment led to its general adoption, with results of such beneficence as to make it rank as one of the great discoveries of the age. |
Origins of Massive Young Stars orbiting the Supermassive Black Hole at the Centre of the Milky Way
The discovery of these stars called “S-stars” in recent years has provided an unprecedented opportunity for studying the black hole at the Galactic centre itself, but it also raised new questions because these massive young stars were orbiting in a region too violent for them to have formed there, implying that they had to have migrated from further out.
When theoreticians produced models explaining the migration of the S-stars toward the centre, the observed orbits didn’t match the models.
Dr. Antonini is offering the best answers to date for this puzzle in his Thursday afternoon talk at the annual meeting of the Canadian Astronomical Society (CASCA). In “The origin of the S-star cluster at the Galactic Centre”, Antonini is presenting a unified theory for the origin and dynamics of the S-stars.
Explaining how these stars managed to get so close in only tens of millions of years since they formed has been a challenge. “Theories exist for how migration from larger distances has occurred, but have up until now been unable to convincingly explain why the S-stars orbit the Galactic centre the way they do”, Antonini said. “As main-sequence stars, the S-stars can not be older than about 100 million years, yet their orbital distribution appears to be ‘relaxed’, contrary to the predictions of models for their origin”.
Antonini and Merritt’s model suggests that the S-stars attained the orbital shapes astronomers have observed by interacting gravitationally with other stars near the central black hole. Their research builds on new insights on how stellar orbits at the Galactic centre evolve due to the joint effect of gravitational interactions with other stars and the super massive black hole.
Merritt says “Theoretical modeling of S-star orbits is a means to constrain their origin, to probe the dynamical mechanisms of the region near the Galactic centre and indirectly to learn about the density and number of unseen objects in this region”.
Supermassive black holes are believed to inhabit the centre of most, if not all, massive galaxies. How they form and grow is intimately connected to the formation of the galaxies they inhabit. The black hole in the centre of our own Galaxy, named Sgr A* (pronounced Sagittarius A-star), is the closest and most extensively studied example. By tracking the orbits of the S-stars over the past several years, astronomers have been able to conclusively show that the object they orbit is indeed a supermassive black hole.
The CASCA annual meeting is being hosted at the University of British Columbia, in Vancouver, BC May 28 – 30. Dr. Antonini is among a dozen CITA faculty, post-doctoral fellows and national fellows giving talks at the meeting.
Model of the Orbits of Stars at the Galactic Centre- Data by Andrea Ghez and Sylvana Yelda, UCLA using the Keck Telescopes. Visualization by Stuart Levy and Robert Patterson, NCSA
CASCA Annual Meeting 2013 Program |
In computing, a shell is a user interface for access to an operating system's services. In general, operating system shells use either a command-line interface (CLI) or graphical user interface (GUI), depending on a computer's role and particular operation. It is named a shell because it is a layer around the operating system kernel.
The design of a shell is guided by cognitive ergonomics and the goal is to achieve the best workflow possible for the intended tasks; the design can be constricted by the available computing power (for example, of the CPU) or the available amount of graphics memory. The design of a shell is also dictated by the employed computer periphery, such as computer keyboard, pointing device (a mouse with one button, or one with five buttons, or a 3D mouse) or touchscreen, which is the direct human–machine interface.
CLI shells allow some operations to be performed faster, especially when a proper GUI has not been or cannot be created, however they require[dubious ] the user to memorize commands and their calling syntax, and to learn the shell-specific scripting language (for example bash script). CLIs are also easier to be operated via refreshable braille display and provide certain advantages to screen readers.
Graphical shells place a low burden on beginning computer users, and they are characterized as being simple and easy to use. With the widespread adoption of programs with GUIs, the use of graphical shells has gained greater adoption. Since graphical shells come with certain disadvantages (for example, lack of support[dubious ] for easy automation of operation sequences), most GUI-enabled operating systems also provide additional CLI shells.
Operating systems provide various services to their users, including file management, process management (running and terminating applications), batch processing, and operating system monitoring and configuration.
Most operating system shells are not direct interfaces to the underlying kernel, even if a shell communicates with the user via peripheral devices attached to the computer directly. Shells are actually special applications that use the kernel API in just the same way as it is used by other application programs. A shell manages the user–system interaction by prompting users for input, interpreting their input, and then handling an output from the underlying operating system (much like a read–eval–print loop, REPL). Since the operating system shell is actually an application, it may easily be replaced with another similar application, for most operating systems.
In addition to shells running on local systems, there are different ways to make remote systems available to local users; such approaches are usually referred to as remote access or remote administration. Initially available on multi-user mainframes, which provided text-based UIs for each active user simultaneously by means of a text terminal connected to the mainframe via serial line or modem, remote access has extended to Unix-like systems and Microsoft Windows. On Unix-like systems, Secure Shell protocol is usually used for text-based shells, while SSH tunneling can be used for X Window System–based graphical user interfaces (GUIs). On Microsoft Windows, Remote Desktop Protocol can be used to provide GUI remote access.
Most operating system shells fall into one of two categories – command-line and graphical. Command line shells provide a command-line interface (CLI) to the operating system, while graphical shells provide a graphical user interface (GUI). Other possibilities, although not so common, include voice user interface and various implementations of a text-based user interface (TUI) that are not CLI. The relative merits of CLI- and GUI-based shells are often debated.
Text (CLI) shells
A command-line interface (CLI) is an operating system shell that uses alphanumeric characters typed on a keyboard to provide instructions and data to the operating system, interactively. For example, a teletypewriter can send codes representing keystrokes to a command interpreter program running on the computer; the command interpreter parses the sequence of keystrokes and responds with an error message if it cannot recognize the sequence of characters, or it may carry out some other program action such as loading an application program, listing files, logging in a user and many others. Operating systems such as UNIX have a large variety of shell programs with different commands, syntax and capabilities. Some operating systems had only a single style of command interface; commodity operating systems such as MS-DOS came with a standard command interface but third-party interfaces were also often available, providing additional features or functions such as menuing or remote program execution.
Application programs may also implement a command-line interface. For example, in Unix-like systems, the telnet program has a number of commands for controlling a link to a remote computer system. Since the commands to the program are made of the same keystrokes as the data being sent to a remote computer, some means of distinguishing the two are required. An escape sequence can be defined, using either a special local keystroke that is never passed on but always interpreted by the local system. The program becomes modal, switching between interpreting commands from the keyboard or passing keystrokes on as data to be processed.
A feature of many command-line shells is the ability to save sequences of commands for re-use. A data file can contain sequences of commands which the CLI can be made to follow as if typed in by a user. Special features in the CLI may apply when it is carrying out these stored instructions. Such batch files (script files) can be used repeatedly to automate routine operations such as initializing a set of programs when a system is restarted. Batch mode use of shells usually involves structures, conditionals, variables, and other elements of programming languages; some have the bare essentials needed for such a purpose, others are very sophisticated programming languages in and of themselves. Conversely, some programming languages can be used interactively from an operating system shell or in a purpose-built program.
The command-line shell may offer features such as command-line completion, where the interpreter expands commands based on a few characters input by the user. A command-line interpreter may offer a history function, so that the user can recall earlier commands issued to the system and repeat them, possibly with some editing. Since all commands to the operating system had to be typed by the user, short command names and compact systems for representing program options were common. Short names were sometimes hard for a user to recall, and early systems lacked the storage resources to provide a detailed on-line user instruction guide.
Graphical shells provide means for manipulating programs based on graphical user interface (GUI), by allowing for operations such as opening, closing, moving and resizing windows, as well as switching focus between windows. Graphical shells may be included with desktop environments or come separately, even as a set of loosely coupled utilities.
Most graphical user interfaces develop the metaphor of an "electronic desktop", where data files are represented as if they were paper documents on a desk, and application programs similarly have graphical representations instead of being invoked by command names.
Modern versions of the Microsoft Windows operating system use the Windows shell as their shell. Windows Shell provides the familiar desktop environment, start menu, and task bar, as well as a graphical user interface for accessing the file management functions of the operating system. Older versions also include Program Manager, which was the shell for the 3.x series of Microsoft Windows, and which in fact ships with later versions of Windows of both the 95 and NT types at least through Windows XP. The interfaces of Windows versions 1 and 2 were markedly different.
Desktop applications are also considered shells, as long as they use a third-party engine. Likewise, many individuals and developers dissatisfied with the interface of Windows Explorer have developed software that either alters the functioning and appearance of the shell or replaces it entirely. WindowBlinds by StarDock is a good example of the former sort of application. LiteStep and Emerge Desktop are good examples of the latter.
Interoperability programmes and purpose-designed software lets Windows users use equivalents of many of the various Unix-based GUIs discussed below, as well as Macintosh. An equivalent of the OS/2 Presentation Manager for version 3.0 can run some OS/2 programmes under some conditions using the OS/2 environmental subsystem in versions of Windows NT.
Graphical shells typically build on top of a windowing system. In the case of X Window System or Wayland, the shell consists of an X window manager or a Wayland compositor, respectively, as well as of one or multiple programs providing the functionality to start installed applications, to manage open windows and virtual desktops, and often to support a widget engine.
"Shell" is also used loosely to describe application software that is "built around" a particular component, such as web browsers and email clients, in analogy to the shells found in nature.
- "Operating system shells". AIX 6.1 Information Center. IBM Corp. Retrieved September 16, 2012.
- "The Life Cycle of a Daemon". Apple Inc.
- "Restart Mission Control in OS X Lion". OSXDaily. Nov 23, 2011.
- British Computer Society: The BCS glossary of ICT and computing terms. Pearson Education. 2005. p. 135. ISBN 978-0-13-147957-9. |
Deductive reasoning inductive reasoning what is deductive reasoning difference between deductive and inductive reasoning research methods what is reasoning. The aim of this paper was to try to provide some insights as to whether the inductive or deductive method of instruction is more effective in the context of teaching. What's the difference between deductive and inductive deductive reasoning uses given this is against the scientific method deductive vs inductive. 3 research methods research types deductive approach inductive approach in research, we often refer to the two broad methods of reasoning as the deductive and. Inductive & deductive research approach by: mohd tajudin b jamaludin contents definition methods inductive teaching deductive teaching. In logic, we often refer to the two broad methods of reasoning as the deductive and inductive approaches. Inductive and deductive method of research - download as word doc (doc / docx), pdf file (pdf), text file (txt) or read online. In logic, we often refer to the two broad methods of reasoning as the deductive and inductive approaches deductive reasoning works from the more general to the more.
A brief description of the differences and connections between deductive and inductive logic. The scientific method uses deduction to test hypotheses and another form of scientific reasoning that doesn't fit in with inductive or deductive reasoning is. Advertisements: there are two method of reasoning in theoretical economics they are the deductive and inductive methods as a matter of fact, deduction and induction. Get expert answers to your questions in mixed methods, quantitative & qualitative research both deductive logic and inductive deductive and inductive you. Using inductive reasoning in user experience research method in research that aims to reach a conclusion based on either inductive reasoning or deductive.
Week 3 deductive and inductive research (1 page) after reading dudley's and neuman's discussions regarding deductive and inductive philosophies or theories. This lesson explores the difference between inductive and deductive reasoning in the form of psychological experiments research methods in psychology. The effectiveness of modified inductive versus deductive teaching a case study on word order amongst a group of english as a foreign language learners. The role of deductive and inductive reasoning in accounting research and to explore the role of deductive and inductive method (deductive approach) the.
Quantitative, qualitative, inductive and deductive research characteristics of quantitative and qualitative research differences between inductive and deduct. Deductive research and inductive research name institutional affiliation deductive research and inductive research it is good to note the reciprocal relationship that.
Learning objectives describe the inductive approach to research, and provide examples of inductive research describe the deductive approach to research, and provide. 1 integrating deductive and inductive approaches in a study of new ventures and customer perceived risk haider ali, cranfield university, silsoe, bedfordshire mk45 4dt.
Software and qualitative analysis 5 logic of qualitative research inductive vs deductive you may have heard or read the position taken that quantitative methods are.
Informed by the scientific method, much research conducted today inductive reasoning and deductive reasoning this is an example of the inductive/deductive. Scientific method: inductive method, deductive method and hypothetico-deductive method with examples , inductive method, notes on research methodology. Comparing inductive and deductive methodologies for design patterns identification and articulation within this research, an inductive, deductive 2. Inductive vs deductive while conducting a research, there are broadly two methods of reasoning that are adopted these are known as inductive and deductive.
Differences between deductive and inductive approaches to research by: jo david | tags: research methods differences between deductive and inductive approaches to. Inductive and deductive instruction in contrast with the deductive method, inductive instruction makes use of student “noticing. Research methods in the real new to these topics when they consider the relationships between theory and research in inductive and deductive approaches to. Figure 21 an illustration of how the inductive and deductive methods can be combined inductive research theoretical perspectives and research methodologies 19. |
The first bicycle-like vehicle was the creation of German engineer Baron Karl von Drais. His 1817 draisienne looked much like a modern bicycle, except it had no pedals. The wooden machine was propelled by the rider’s feet. Scottish blacksmith Kirkpatrick Macmillan put pedals to the draisienne in 1839. Driving cranks attached to the rear axle, the pedal mechanism was too inefficient to catch on.
A much better bicycle came along in 1861, the product of French father and son Pierre and Ernest Michaux. Their vélocipède had pedals attached to a large front wheel. Sitting atop this wheel, the rider turned the pedals—one rotation would turn the wheel all the way around. The wheels were made of iron or solid rubber, and gave such a bumpy ride that it was also nicknamed the boneshaker.
In England, a similar contraption became known as the penny-farthing (after the penny coin and the much smaller farthing), its front wheel as large as five feet in diameter. It was very unsafe. Falls from the high wheel were common. Attempts to reduce accidents by placing the small wheel in front were unsuccessful.
In 1885 the safety bicycle was introduced by English bicycle maker J. K. Starley. As on the draisienne, the wheels were the same size. But on the safety bicycle the pedals drove a chain attached to the rear wheel, and the saddle was atop a diamond-shaped frame. The pattern for the modern bicycle was in place. The solid rubber tires were replaced by pneumatic (air-filled) tyres in 1887, an innovation by Scottish inventor John Dunlop for his son’s bike. By 1890 coaster brakes were added, and millions of people were riding bicycles. Later improvements gave bicycles the distinction of being perhaps the most efficient means of self-propulsion ever devised. |
Normally light microscopy can at most resolve details roughly half the wavelength of the light used. If light is squeezed past this limit, it flares out from an aperture as two portions: a far-field part that spreads out, and a near-field fraction that remains close, decaying rapidly once emitted. Conventional lenses can capture far-field light, but they lose all the information about details smaller than a wavelength contained in near-field light. Metal probe tips scanning over a surface can detect this near-field light, but until now they could only "see" what they touch and not below.
To get a better glimpse of features below the skin of an object, physicist Rainer Hillenbrand at the Max Planck Institute for Biochemistry in Martinsreid, Germany, and his colleagues used superlenses. These novel devices exploit a property called permittivity, which describe a substance's ability to transmit an electric field. Specifically, the superlenses combine materials with negative and positive electric permittivities, so that internal electric fields align in opposite directions from each other in response to external fields. The result: superlenses can recover near-field as well as far-field light.
The researchers placed a superlens made of crystalline silicon carbide 440 nanometers thick between the scanning microscope tip and a gold film patterned with holes of different sizes. They showed they were able to image details using infrared light that were 1/15 the size of the wavelength used and 880 nanometers below the surface.
A limitation of this new technique, reported in the September 15 Science, is that the maximum depth it can see below the surface of an object and the size of the tiniest details it can resolve are the same--the width of the superlens. In other words, this method cannot realistically image relatively tiny features that are buried relatively deep below a surface at the same time, explains researcher Gennady Shvets, a physicist at the University of Texas at Austin.
In comparison, ultrasound can simultaneously image details as little as 20 nanometers in size and as much as 1,000 nanometers below the surface. In addition, it can also probe mechanical properties. Still, superlenses could help determine chemical properties of scanned features much better than ultrasound, suggests metrologist Alain Diebold, a senior fellow at semiconductor consortium SEMATECH in Austin, Tex., who did not participate in the study.
Moreover, past light microscopy techniques using scanning probes involved mechanical contact between the tip and the sample, "and fragile samples often prevented a high-resolution measurement process, making, for example, the optical probing of living cells nearly impossible," Hillenbrand says. Superlenses could help probe cells a distance from their surface "in their natural environment," he explains, and could also help examine defects in electronics. |
A structure in mathematics (also “mathematical structure”) is often taken to be a set equipped with some choice of elements, with some operations and some relations. Such as for instance the “structure of a group”. In model theory this concept of mathematical structure is formalized by way of formal logic.
Notice however that by far not every concept studied in mathematics fits as an example of a mathematical structure in the sense of classical first oder model theory, described below. For instance a concept as basic as that of topological spaces fails to be a structure in the sense of classical model theory (see here).
Given a first-order language , which consists of symbols (variable symbols, constant symbols, function symbols and relation symbols including ) and quantifiers; a structure for , or “-structure”, is a set with an interpretation for symbols:
if is an -ary relation symbol, then its interpretation
if is an -ary function symbol, then is a function
if is a constant symbol, then
The underlying set of the structure is referred to as (universal) domain of the structure (or the universe of the structure).
Interpretation for an -structure inductively defines an interpretation for well-formed formulas in . We say that a sentence is true in if is true. Given a theory , which is a language together with a given set of sentences in (axioms), the interpretation in a structure makes those sentences true or false; if all the sentences in are true in we say that is a model of .
In model theory, given a language , a structure for is the same as a model of as a theory with an empty set of axioms. Conversely, a model of a theory is a structure of its underlying language that satisfies the axioms demanded by that theory.
There is a generalization of structure for languages/theories with multiple domains or sorts, called multi-sorted languages/theories.
A class of structures of a given signature is an elementary class if there is a first-order theory such that consists precisely of all models of .
Every first-order language gives rise to a first-order hyperdoctrine with equality freely generated from . Denoting this by , the base category consists of sorts (which are products of basic sorts) and functional terms between sorts; the predicates are equivalence classes of relations definable in the language. The construction of depends to some extent on the logic we wish to impose; for example, we could take the free Boolean hyperdoctrine generated from if we work in classical logic.
There is also a “tautological” first order hyperdoctrine whose base category is , and whose predicates are given by the power set functor
and then an interpretation of , as described above, amounts to a morphism of hyperdoctrines .
This observation opens the door to a widened interpretation of “interpretation” in categorical logic, where we might for instance generalize Set to any other topos , and use instead (taking an object of to its Heyting algebra of subobjects) as the receiver of interpretations. This of course is just one of many possibilities.
Standard textbook accounts include
Wilfrid Hodges, section 1 of A shorted model theory, Cambridge University Press (1997)
Chen Chung Chang, H. Jerome Keisler, Model Theory. Studies in Logic and the Foundations of Mathematics. 1973, 1990, Elsevier.
Online discussion includes |
HOP TO IT!
Students will learn how a frog's strong back legs allow it to
hop long distances. Segments from two ITV programs will be used to help
students become interested in imitating the jumping behaviors of frogs.
The students will estimate the distances they can jump with two different
movements. They will jump and measure the actual distances to determine
which kind of jumping resulted in longer jumps. The students will use this
information to make second estimates and jumps. This information, as well
as their personal reactions to the comfort and ease of each type of jump,
will help students determine which kind of jumping is best for them. Although
this lesson could stand alone, it would fit nicely as the opening activity
in a science study about frogs or within a unit on measurement. This lesson
can be completed in one day.
Reading Rainbow #415: My Little Island
The Magic School Bus #105: The Magic School Bus Hops Home
Students will be able to:
- estimate the distance they will travel with two different types of
- measure the distance of the two different types of jumps using nonstandard
measurements (such as linking cubes, especially for younger students) or
standard measurements (centimeters, in most cases).
- use the information gathered from the first set of two jumps to estimate
the distance they will travel with a second round of jumps.
- use the information they have gathered to draw a conclusion about
the best type of jumping for them.
Texas Assessment of Academic Skills (TAAS), Grades K-4:
- Demonstrate an understanding of measurement concepts using metric
and customary units.
- Demonstrate an understanding of probability and statistics.
- Estimate solutions to a problem situation.
- Acquire scientific data and/or information.
- Interpret scientific data and/or information.
- Make inferences, form generalized statements, and/or make predictions
using scientific data and/or information.
if using nonstandard measure:
- diagram of a hopping frog
if using standard measure:
- linking cubes
- large paper clips
- crayons or straws
- tape measures or meter sticks
- a recording sheet
- pencil or crayon
- front legs
- back legs
Tell students that in this activity they will be moving like a certain animal
and measuring to see how well they do at moving like this animal. Ask the
students to guess what animal they will be moving like. After several students
have had the opportunity to guess, tell them that LeVar Burton was out on
a search for one of these animals in the Reading Rainbow program about the
book "My Little Island". Tell students that they should watch
carefully to determine what animal LeVar was looking for and where he would
find this animal.
Background information: Frogs are amphibians. They have backbones and their
skeletons are inside their bodies. Frogs are cold-blooded, so their body
temperature stays the same as the air or water around them. Frogs usually
have moist skin. A frog has a large mouth with a long sticky tongue that
shoots out quickly to catch prey like insects. Frogs lay eggs in the water
which hatch into tadpoles. Tadpoles go through metamorphosis, which is a
series of changes to the size, shape, and appearance of it body. Frogs have
four appendages. The two front legs are short and weak. Each front leg has
four toes and is used for balance and to land after a jump. The two back
legs are long and well developed. Each back leg has five toes and many frogs
have webbed back feet used for swimming. A frog rests with its back legs
folded so it can hop quickly to catch prey or to escape from predators.
(Information about frogs adapted from Victor, E. (1975) Science for the
Elementary School, Third Ed., New York: Macmillan Publishing, p. 524-525.)
In this lesson, it is important that students learn how to jump safely and
use this information during the jumping activity to prevent injuries. Demonstrate
and explain the appropriate ways to jump carefully to the students.
Frog jump: The student will squat, with hands on the floor in front of the
feet. The student will jump a short distance and land on the hands and feet
simultaneously. The hands and arms absorb part of the landing impact to
prevent excessive strain on the knees. The students should be frequently
encouraged to consider personal estimates and actual measures in order to
discourage aspects of competition in jumping.
Standing jump: The student will bend legs at knees, jump by taking off with
both feet, swing arms forward upon takeoff, and will land on both feet.
The arms help with an upswing and the movement of the body combined with
the force of the feet helps lift the weight. A jumper lands lightly on the
balls of the feet with the knees bent. (Information adapted from Dauer,
V. P. & Pangrazi. (1989). Dynamic Physical Education For Elementary
School Children. New York: Macmillan, p. 281, 282, 448.)
Segments from two ITV programs are used in this lesson. Reading Rainbow
is used as an anticipatory set to create interest in frogs. The Magic School
Bus segment is used to help students focus on how frogs can jump. Since
one of the purposes of using the first video is to discover the animal and
what it can do, there are no pre-viewing activities.
CUE the Reading Rainbow video to the point after the
book reading segment and LeVar has been to a market to examine fruits and
vegetables on sale there. BEGIN the video as LeVar says, "Some
of the fruit here is pretty wild. But it's not only the wild life here on
Monserrat. Meet me tonight up in the mountains and I'll show you what I
mean." PAUSE after LeVar says, "Ssh! We're out here trying
to catch mountain chickens. You gotta be quick. But they're usually quicker."
Ask, "Where is LeVar?" (in the mountains, a place with lots of
trees, dark) Ask, "What is LeVar looking for?" (mountain chickens)
Ask, "What do you think mountain chickens are?" (Students may
make various guesses such as birds or chickens.)
Tell students to watch the next segment to see if they find a mountain chicken.
RESUME the video to continue as LeVar and his guide are prowling
in the dark. PAUSE as the hand reaches down before it picks up the
frog. Ask, "Do you think they found something?" (yes) Ask, "What
might he have found?" (a mountain chicken, a frog, others) Ask, "Why
might it be hard to spot the mountain chicken?" (too dark, animal is
camouflaged, its color makes it hard to see)
Tell students to watch the next segment to see what he caught. RESUME
video and PAUSE where guide picks up frog and says, "LeVar,
I got one. Come, you see it." Ask, "What did he catch?" (a
mountain chicken, a frog)Tell students to watch the next segment to see
if the frog is really a mountain chicken. RESUME video to continue
through the examination of the frog's back. PAUSE where LeVar says,
"One of the reasons they're so difficult to catch." Ask, "Is
it a mountain chicken? (yes) Why do you think they call it that? (it lives
in the mountains, people like to eat frogs' legs, some people say it tastes
like chicken) [Note: These points are not discussed in the video, so the
teacher may need to discuss these ideas with the students.]
Ask, "What is special about this frog?" (the eyes look fluorescent-
they glow, the mouth can expand like a balloon to make sounds, the color
of its back makes it hard to see)
Tell students the frog's legs help it to do something special. Tell students
to watch the next segment to see what else is special about its legs. RESUME
the video. PAUSE after LeVar says, "Stay right there, you guy."
Ask, "What are the frog's legs like? (long, strong, funny toes) What
can the frog do? (jump far) How can the frog jump far? (strong legs push
him) How did LeVar say the frog felt? (slippery) Why do you think the frog
felt slippery? (he was wet, rain, frogs like to be wet) What did LeVar say
the toes look like?" (twigs from a tree)
Tell students that LeVar is going to put the frog down. Ask, "What
do you think the frog will do?" (jump, hop away) Tell students to watch
the next segment to see what the frog will do. RESUME the video.
STOP the video where LeVar puts the frog on the ground and says,
"There you go, guy." and the frog sits on the ground. Ask, "What
did the frog do? (sat on the ground) Why do you think he didn't hop away?
(he was scared, he was trying to hide)
What do you think of when someone mentions frogs? Jumping, of course. But
how far can a frog jump? Tell students to think about how far frogs can
jump as they watch a segment of The Magic School Bus Hops Home. EJECT
the Reading Rainbow video and INSERT The Magic School Bus
Tell students to watch the first segment to see what the problem is. BEGIN
The Magic School Bus video with the first appearance of the Magic School
Bus. PAUSE after the bus shrinks and the cat first appears. Ask,
"What is the problem? (the frog is missing) How will they find the
missing frog? (by acting like a frog) What does the bus do? (turns into
a frog, it shrinks, gets smaller) How big is the bus when it shrinks?"
(about the size of a frog)
Tell students to watch to see how they will know where to go. RESUME
video to continue as bus hops. PAUSEwhere Ralphie says, "Ms.
Frizzle, do we have to hop?" Ask, "What did the bus hop over?
(a fence) Do you think a frog could hop over a fence like that? (yes) Where
might Bella the frog have gone? (to find food) What kind of food did they
say Bella would like? (bugs) Where might they go to find bugs?" (outside,
FAST FORWARD until the cat begins to stalk the bus. Tell students
to watch the next segment to see where the bus goes. RESUME video
and continue as the bus jumps into a tree. PAUSE as Carlos says,
"It's just a little mishap." Ask, "Where did the bus hop?
(into a tree) Do you think a frog could really hop that far?" (It's
pretty high, but some frogs live in trees.)
FAST FORWARD past the jump out of the tree, past the fast moving
water, past the heron and STOP the video where the beavers build
a dam. Tell students to watch the next segment to see if Bella is there.
RESUME video and continue as it shows the heron stalking the frog.
PAUSE when the empty lily pad is shown and the children call, "Wanda!"
Ask, "Where was Bella? (in a beaver pond) Why was she there? (slow
moving water, food) Why did the frog disappear? (a heron was coming) What
did the heron want? (to eat the frog) How did the frog get away from the
heron?" (it hopped away)Tell students to watch the next segment to
see if Bella and Wanda are OK. RESUME video. STOP the video
after Ms. Frizzle says, "They're all part of the same food chain."
Ask, "Why is the beaver pond a good place for Bella the frog to live?
(It has food, slow moving water to swim in and lay eggs in, and space to
hop.) What would the frog like to eat? (bugs) What did the frog do to catch
a bug?" (hopped)
Could we really shrink to be as little as a frog? No, it's not
possible. But we can imagine that we can hop like a frog. They will see
if they can jump better on four legs like a frog or on two legs like a person.
Explain to the students that they will hop or jump in two different ways.
One way will be more like the way a frog hops. Describe and model how to
do a frog jump. (See explanation in background information section.) Then
describe and model how to do a standing jump like a person might do. (See
explanation in background information section.) Which way do the students
think will make a longer jump? It is beneficial for students to have some
points of reference about the measurements they will be using in the activity.
For younger students, nonstandard measurement with materials such as linking
cubes or large paper clips is an appropriate measurement tool. Show the
students the materials they will use. About how long is one unit? About
how long are ten units? Let students compare 1 unit, 10 units, and 100 units
to things they know, such as parts of their bodies. A similar process should
be followed if using standard measurements. Ask students to examine the
tape measure and find a part of their hand which is about one centimeter.
The width of a pinky, for example, is usually about one centimeter. Now
ask students to use their hands to estimate the length of 10 centimeters.
Young students may find they can open their fingers just a bit to get a
hand spread which will match 10 centimeters on the tape measure. Then ask
students to estimate and check on 100 centimeters on the tape measure. Children
may relate this to the span of both arms stretched wide or to the length
of a table or desk. Now that the students have some general ideas about
the length of 1, 10, and 100 centimeters, they are ready to estimate. Each
student should use a recording sheet (see attachment) to write an estimate
for the distance he or she will travel with one frog jump and with one long
jump. You may wish to use an overhead transparency of the recording sheet
to demonstrate to students how to write their estimates. Emphasize that
estimates are only guesses at this point and that we are not concerned about
correctness. You might have the students write their estimates with crayons
to discourage them from wanting to change the estimates after they do the
actual jumping. After all students have made estimates for the distance
they will go with each jump, the group is ready to begin. Identify the starting
line and have each student do the frog jump. After jumping, each student
should write the distance under "actual distance". Then have each
student do the long jump and write the distance under "actual distance".
When the actual distances are written on the recording sheet, the differences
between the estimates and the actual measurements need to be determined.
Calculators may be used for this. Students should now be asked to reflect
upon their experiences in doing the activity the first time. Allow for about
two minutes to reflect quietly. Ask students to use the information they
found to make a second round of estimates on the bottom half of the recording
sheet. After each of the members of the group has written estimates, the
group is ready to complete the activity a second time with a new round of
jumping and finding the differences between estimates and actual distances.
Ask students to put a star by the kind of jump which took them farther.
Then ask the students to put a happy face by the kind of jump which was
easier. Have the students use this information to determine which type of
jump was best for them. Make a graph of the choices made by the students.
Which type of jump was chosen more often? Ask students why they think this
The students can use the Internet to access the Froggy Page
at Yale University through http://www.cs.yale.edu/homes/sjl/froggy.html.
Have the students use telecommunications to communicate the results of their
jumping experiment and encourage others to try and send their results.Have
students research to determine if any types of frogs are on the endangered
species list. Why would these frogs be endangered? What can people do to
Science: Bullfrogs eat bugs and herons eat bullfrogs. Frogs
are part of a food chain. Have students research and create a picture to
show the food chain mentioned briefly in The Magic School Bus Hops Home.
Writing: Create a word web to tell about frogs. Ask students to think of
things they know about frogs. This information could come from the video
or from their own knowledge and experiences. You may wish to collect the
information about frogs by writing a web such as this on the blackboard
or on a chart. This information can be used by students to write about frogs.
Mathematics: Have the students use a bar graph to compare the actual results
of their best of each of the two types of jumps. Ask students to examine
the graphs to help them make judgments about these two types of jumping.
What other kinds of jumps might children make? Have the students determine
another kind of jump and estimate, jump, record, graph, and compare these
results to those from the first two types. What does this new information
help us to understand about jumping?
Health: Jumping can be good exercise. Have students experiment with other
types of jumps, such as the long jump or the triple jump. Which kind of
jump helps students jump farther?
Click here to view the
worksheet associated with this lesson.
NOTE TO TEACHER
For the english learner: The student who is learning English as a Second Language
will benefit from the active demonstration and practice of vocabulary in
the lesson. As the students participate in the activity, be sure to emphasize
the words which tell what they are doing, such as squat, jump, hop, and
land. Also be sure to emphasize the names of the parts of the body used
for jumping, including hands, arms, feet, knees, and legs. These words may
be printed on word cards to help the student connect the spoken word with
the written word. Students will have the opportunity to use mathematical
vocabulary, such as estimate, distance
Lesson Plan Database
Thirteen Ed Online |
The book of Judges describes the time period between Joshua and King Saul when Israel had no king. God wanted his people to follow his instructions through the law and prophets, but they always turned from him.
Because of their disobedience, God would subject to foreign powers. Afterwards they would repent and God would call a leader known as a Judge to deliver them out of bondage. The Judges were often warriors inspired by the Spirit of God, although sometimes there were Judges who simply held authority and acted as leaders of the people. In the book of judges we can find the circle of disobedience-punishment-regret-salvation- quiet in some famous stories, the first is othniel.
Who was Othniel?
Othniel Ben kenaz was the first judge of Israel. His name means the power of god. Othniel was a member of the tribe of Caleb .He was the only Judge menioned connected with the Tribe of Judah.
The Old testament describes othniel act's only in 5 verses, as written:
וַיַּעֲשׂוּ בְנֵי-יִשְׂרָאֵל אֶת-הָרַע בְּעֵינֵי יְהוָה, וַיִּשְׁכְּחוּ אֶת-יְהוָה אֱלֹהֵיהֶם; וַיַּעַבְדוּ אֶת-הַבְּעָלִים, וְאֶת-הָאֲשֵׁרוֹת. וַיִּחַר-אַף יְהוָה, בְּיִשְׂרָאֵל, וַיִּמְכְּרֵם בְּיַד כּוּשַׁן רִשְׁעָתַיִם, מֶלֶךְ אֲרַם נַהֲרָיִם; וַיַּעַבְדוּ בְנֵי-יִשְׂרָאֵל אֶת-כּוּשַׁן רִשְׁעָתַיִם, שְׁמֹנֶה שָׁנִים. וַיִּזְעֲקוּ בְנֵי-יִשְׂרָאֵל אֶל-יְהוָה, וַיָּקֶם יְהוָה מוֹשִׁיעַ לִבְנֵי יִשְׂרָאֵל וַיֹּשִׁיעֵם--אֵת עָתְנִיאֵל בֶּן-קְנַז, אֲחִי כָלֵב הַקָּטֹן מִמֶּנּוּ. וַתְּהִי עָלָיו רוּחַ-יְהוָה, וַיִּשְׁפֹּט אֶת-יִשְׂרָאֵל, וַיֵּצֵא לַמִּלְחָמָה, וַיִּתֵּן יְהוָה בְּיָדוֹ אֶת-כּוּשַׁן רִשְׁעָתַיִם מֶלֶךְ אֲרָם; וַתָּעָז יָדוֹ, עַל כּוּשַׁן רִשְׁעָתָיִם. וַתִּשְׁקֹט הָאָרֶץ, אַרְבָּעִים שָׁנָה; וַיָּמָת, עָתְנִיאֵל בֶּן-קְנַז
"And the children of Israel did that which was evil in the sight of the LORD, and forgot the LORD their God, and served the Baalim and the Asheroth. Therefore the anger of the LORD was kindled against Israel, and He gave them over into the hand of Cushan-rishathaim king of Aram-naharaim; and the children of Israel served Cushan-rishathaim eight years. And when the children of Israel cried unto the LORD, the LORD raised up a saviour to the children of Israel, who saved them, even Othniel the son of Kenaz, Caleb's younger brother. And the spirit of the LORD came upon him, and he judged Israel; and he went out to war, and the LORD delivered Cushan-rishathaim king of Aram into his hand; and his hand prevailed against Cushan-rishathaim. And the land had rest forty years. And Othniel the son of Kenaz died"
30 years after the death of Joshuah, the people of Israel fell under the rule of Mesopotamia. Othniel delivered the erring Israelites from eight years of oppression by Cushan-rishathaim, king of Mesopotamia.
.Peace lasted for forty years during his time as a Judge of Israel. After these forty years , Israel fell under the subjection of Eglon , king of moab.
main phrases of the post + transcription + translation
Hebrew Transcription Translation
חֲרָטָה hărātāh regret
עֹנֶשׁ 'ones punishment
שָׁפַט šāpat Judged (past)
יְשׁוּעָה yəšû'āh salvation
שִׁעְבּוּד Ši'bûd subjection
שֵׁבֶט šēbet tribe
דִּכּוּי dikkûy Oppression |
About Divergent ZonesWhere lithospheric plates move apart
Where the lithospheric plates move apart from each other, the boundary between them becomes a divergent margin. Unlike convergent margins, divergent margins involve only oceanic or only continental lithosphere, not one of each. Today the vast majority of divergent margins are in the ocean, where they were not mapped or understood until late in the 20th century. Of all these oceanic divergent margins, only Iceland stands above the waves. Two examples on the continents are the Afar region of east Africa and the Imperial Valley of California/Mexico.
New lithosphere is born hot and cools over millions of years. As it cools it shrinks, thus the fresh sea floor stands higher than the older lithosphere on either side. This is why divergent zones take the form of long, wide swells running along the ocean floor: mid-ocean ridges. The ridges are only a few kilometers high but hundreds wide. The slope on the flanks of a ridge means that diverging plates get an assist from gravity, a force called "ridge push" that together with slab pull accounts for most of the energy driving the plates. On the crest of each ridge is a line of volcanic activity. This is where the famous black smokers of the deep sea floor are found.
Plates diverge at a wide range of speeds, giving rise to differences in spreading ridges. Slow-spreading ridges like the Mid-Atlantic Ridge have steeper-sloping sides because it takes less distance for their new lithosphere to cool. They have relatively little magma production so that the ridge crest can develop a deep dropped-down block, a rift valley, at its center. Fast-spreading ridges like the East Pacific Rise make more magma and lack rift valleys.
The best example on Earth today is the narrow Red Sea, where the Arabia plate has pulled away from the Africa plate. Because Arabia has run into southern Asia while Africa isn't going anywhere, the Red Sea won't widen into a Red Ocean soon. It probably isn't a typical case.
Divergence is also going on in the great rift valleys of East Africa, forming the boundary between the Africa and Nubia plates. But these rift zones, like the Red Sea, have not opened much though they are millions of years old. Apparently the tectonic forces around Africa are pushing on the continent's edges.
One fact not widely appreciated is that divergent margins move sideways just like the plates themselves do. To see this for yourself, take a bit of string cheese and pull it apart in your two hands. If you move your hands apart, both at the same speed, the "rift" in the cheese stays put. If you move your hands at different speedswhich is what the plates generally dothe rift moves too. This is how a spreading ridge can migrate right into a continent and vanish, as is happening in western North America today.
This exercise should demonstrate that divergent margins are passive windows into the asthenosphere, releasing magmas from below wherever they happen to wander. While textbooks often say that plate tectonics is part of a convection cycle in the mantle, that notion cannot be true in the ordinary sense. Mantle rock is lifted to the crust, carried around, and subducted somewhere else, but not in the closed circles called convection cells. |
The handscroll is a long narrow scroll for displaying a series of scenes in Chinese, Japanese, Indian, or Korean painting and calligraphy. The handscroll presents an artwork in the horizontal form and can be exceptionally long, usually measuring up to a few meters in length and around 25–40 cm in height. Handscrolls are generally viewed starting from the right end. This kind of scroll is intended to be viewed flat on a table while admiring it section for section during the unrolling as if traveling through a landscape. In this way, this format allows for the depiction of a continuous narrative or journey.
The handscroll originated from ancient Chinese text documents. From the Spring and Autumn period (770-481 BCE) through the Han dynasty (206 BCE - 220 CE), bamboo or wooden slips were bound and used to write texts on. During the Eastern Han period (25-220), the use of paper and silk as handscrolls became more common. The handscroll was the one of the main formats for texts up until the Tang dynasty (618-907). Since the Three Kingdoms (220–280), the handscroll became a standard form for mounting artwork. In India, a scroll painting genre called Pattachitra evolved, whose origin dates back to the 5th century BC. Pattachitra is a general term for traditional, cloth-based scroll painting. In the Sanskrit language, "Patta" literally means "cloth" and "Chitra" means "picture". Most of these paintings depict stories of Hindu deities. New styles were developed over time.
A handscroll has a backing of protective and decorative silk (包首) with a small title label (題籤) on it. The front of a scroll usually consists of a frontispiece (引首) at the right side, the artwork (畫心) itself in the middle, and a colophon panel (拖尾) at the left side for various inscriptions. The right side of the scroll, to where the frontispiece was located, is known as the "heaven" (天頭). Vertical strips (隔水) are used to separate the different sections. Most handscrolls display only one painting, although several short paintings can also be mounted on the scroll. On the right end of a scroll is a wooden stave (天杆), which serves as a support to a scroll. A silk cord (帶子) and a fastener (別子) is attached to the stave and used to secure a rolled-up scroll. A wooden roller (木杆) is attached on the left end and forms an axis to help roll up a scroll. |
How do we know the age of the universe is 13.7 billion years?
We say the universe is 13.7 billion years old, while the farthest matter we have ‘looked’ at is about 480 million years older than our Universe’s supposed birth-moment
(to experts) Why haven’t we seen further than that? Is it because of the limitations of our equipment or because light from that far hasn’t reached us yet? And if we cannot see further than that, on what basis do we calculate the age of our universe?
This question is in the General Section. Responses must be helpful and on-topic. |
What is Dysarthria?
Dysarthria is a motor-speech disorder that results in unclear speech. This inability to speak clearly is because of weakness, slowness, or lack of coordination in the muscles of the mouth, voice, and lungs.
Dysarthria results from damage to the nervous system. There are several different types of dysarthria. The type of dysarthria a person has is determined by the area of the nervous system that’s damaged.
In unilateral dysarthria, just one side of the face and tongue is weak. In spastic dysarthria, the muscles on both sides are stiff and uncoordinated. With flaccid dysarthria, the muscles are loose and floppy. In ataxic dysarthria, muscle movements are uncoordinated. Hyperkinetic dysarthria involves involuntary muscle movements, while hypokinetic dysarthria features muscle movements that are slow to start. There are also many mixed dysarthrias that include features of more than one type.
Dysarthria can be a mild annoyance, or it can have a devastating effect on a person’s ability to make him or herself understood.
What Causes Dysarthria
Dysarthria can be caused by a stroke, head injury, or brain tumor. It can also be caused by a congenital disorder such as cerebral palsy, or a degenerative disease such as amyotrophic lateral sclerosis (ALS), multiple sclerosis, or Parkinson’s disease.
What You Might Notice
Dysarthria affects different people in different ways.
Some people sound like they’re mumbling or slurring their words. Some sound like they’re talking through their noses, while others sound stuffed up.
Some speak in a monotone, while others make extreme pitch changes. Some speak slowly, some speak very quickly, and some fluctuate. Some speak loudly, some speak softly, and some are irregular in volume. Their voices may sound unusually hoarse, breathy, or strained.
Dysarthria can affect more than just speech. Someone with dysarthria may look like his or her face is drooping. They may have difficulty swallowing, or get food caught in the cheeks. Due to limited movement of the tongue, lips, or jaw, the person may drool or have trouble keeping dentures in place. Even breathing may be irregular, if the lungs are affected.
If You Have Dysarthria
If you have dysarthria, you may find talking to be difficult and frustrating. Take your time and follow these tips:
- Sit up and face your listener if possible. It’s important to make eye contact so your listeners can understand you better by watching your lips. You might want to avoid wearing a moustache that hides your upper lip.
- Speak slowly and loudly, exaggerating how each word is supposed to sound. Pause to take a breath when you need one.
- Use facial expressions, gestures, drawing, and pointing to help get your message across.
- If your listener has trouble understanding you, try using different words if repeating the exact words hasn’t worked.
- If you need to, write down what you want to say or key words. You can also point to the first letter of words on a letter board.
- Swallow before speaking to clear your mouth of saliva. Clear your throat if you need to so your voice will be clear.
- Try to relax and stay calm. If you have trouble, it’s okay to give up and come back to the subject later. Avoid important conversations when you’re tired or feeling emotional.
5 Ways to Help a Person with Dysarthria
A person with dysarthria can improve a great deal through speech therapy. Meanwhile, you can help the person communicate by taking a few simple actions:
- Make sure your surroundings are quiet and well lit. Turn off the TV and radio, and shut the door, so you won’t be interrupted. Be sure the lights are on or the curtains are open.
- Sit across from the person, so you can make eye contact. His or her body language and lip movements can tell you a lot.
- Establish the topic, so you both know what you’re discussing.
- Be patient. Give the person plenty of time to speak.
- If you don’t understand what the person is trying to say, don’t pretend you do. Instead, say what you do understand, using his or her exact words. Then ask specifically for the words that are unclear.
Want to learn more about dysarthria or other communication disorders in adults? Visit our Knowledge Center to discover helpful resources. We also have a wide variety of apps for dysarthria therapy you can download to get started on improving communication today. |
Itching is an intense, distracting irritation or tickling sensation that may be felt all over the skin's surface, or confined to just one area. The medical term for itching is "pruritus." Itching instinctively leads most people to scratch the affected area. Different people can tolerate different amounts of itching, and anyone's threshold of tolerance can be changed due to stress, emotions, and other factors. In general, itching is more severe if the skin is warm, and if there are few distractions.
This is why people tend to notice itching more at night.
Most people experience some soreness or itching around their anus (bottom) at some time. Fortunately for most of us this is only a temporary problem. But for some sufferers it can be a great ordeal. In most patients, Pruritus is due to inflammation (dermatitis of the sensitive skin just around the anus). The skin in this area is one of the most sensitive parts of the body. It is particularly prone to inflammation. This is not surprising because the area is frequently smeared with motion and is soggy due to perspiration.
Itching that occurs all over the body may indicate a medical condition such as diabetes mellitus, liver disease, kidney failure, jaundice, thyroid disorders (and rarely, cancer). Blood disorders such as leukemia, and lymphatic conditions such as Hodgkin's disease may sometimes cause itching as well. Some people may develop an itch without a rash when they take certain drugs (such as aspirin, codeine, cocaine); others may develop an itchy red "drug rash" or hives because of an allergy to a specific drug. Itching also may be caused when any of the family of hookworm larvae penetrate the skin. This includes swimmer's itch and creeping eruption caused by cat or dog hookworm, and ground itch caused by the "true" hookworm.
Specific itchy areas may occur if a person comes in contact with soap, detergents, and wool or other rough-textured, scratchy material. Adults who have hemorrhoids, anal fissure, or persistent diarrhea may notice itching around the anus (called "pruritus ani"). In children, itching in this area is most likely due to worms. Intense itching in the external genitalia in women ("pruritus vulvae") may be due to candidiasis, hormonal changes, or the use of certain spermicides or vaginal suppositories, ointments, or deodorants. It's also common for older people to suffer from dry, itchy skin (especially on the back) for no obvious reason. Younger people also may notice dry, itchy skin in cold weather. Itching is also a common complaint during pregnancy.
Itching is one of the easiest symptoms to detect in a child over three months of age, which is about when babies have the hand coordination they need to scratch. Children will rub, claw and pick at itchy areas until they are raw and bleeding. In many cases, they feel the itch and begin to scratch before any rash is visible. In eczema, for example, the rash typically appears after the child scrapes away at the itchy, dry skin. Itching is not a disorder in itself, but a symptom of another problem. Itching can develop as a small patch in a specific area or allover the body. Scratching will produce redness, bumps and even bleeding if the injury breaks the skin. Scratching can lead to infection.
If a skin rash or irritation goes with it, then itching is usually the result of a fungal, parasitic or scabies infection. It can also be part of an internal process such as chickenpox or measles; or a skin disorder, like eczema, psoriasis or dandruff. Allergies cause the skin to itch, even before an eruption appears. Excess toxins are eliminated through the skin, as it is the final detoxifying organ in the digestive process. Insect bites, especially from mosquitoes, or dry skin can be the problem due to a lack of essential fatty acids in the body, particularly in the elderly. In some cases, itchy skin can also be a sign of a more serious illness, like diabetes, leukemia or kidney failure, when other symptoms exist.
Itching can be a side-effect of prescription and over-the-counter drugs. Jaundice from the back-up of bile will cause the skin to itch and turn yellow. If confined to the anal area, the cause is constipation, fissures, hemorrhoids or worms, and if situated in the genital area, it is often the result of a vaginal yeast infection, although a sexually transmitted disease like trichomoniasis should be ruled out. Itching is an early symptom of shingles (herpes zoster), a condition more common in people over the age of sixty. Another cause of itching is a deficiency in B vitamins (especially biotin), vitamin A, iron, selenium, silicon, zinc, essential fatty acids and vitamin E. It is not uncommon to find itching the result of psychological causes related to stress, drug abuse, alcohol or tobacco excesses.
There are treatments available to reduce itching. Antihistamine medications such as hydroxyzine and diphenhydramine can be helpful. Another type of medication is topical corticosteroids such as hydrocortisone cream. Occasionally, oral corticosteroids such as prednisone are used for severe rashes. Other remedies such as calamine lotion are also available.
Treatment of the cause is also important, when possible. For example, antibiotics can be used to treat scabies. A thyroid hormone imbalance can often be corrected with medications. Surgery, chemotherapy, or radiation therapy may be needed to treat a tumor or cancer. Treatment of anal itching depends upon what is causing the problem. Gently wipe your anus well with toilet paper after having a BM. Use soap and water to wash between your legs each day. Dry this area well after washing. Wear cotton underwear and loose-fitting clothes. Do not use soaps or perfumes in the anal area that may bother your skin.
Antihistamines such as diphenhydramine (Benadryl) can help relieve itching caused by hives, but won't affect itching from other causes. Most antihistamines also make people sleepy, which can help patients sleep who would otherwise be awake from the itch.
Specific treatment of itching depends on the underlying condition that causes it. In general, itchy skin should be treated very gently. While scratching may temporarily ease the itch, in the long run scratching just makes it worse. In addition, scratching can lead to an endless cycle of itch--scratch--more itching. To avoid the urge to scratch, a person can apply a cooling or soothing lotion or cold compress when the urge to scratch occurs. Soaps are often irritating to the skin, and can make an itch worse; they should be avoided, or used only when necessary. Creams or ointments containing cortisone may help control the itch from insect bites, contact dermatitis or eczema. Cortisone cream should not be applied to the face unless a doctor prescribes it. |
Powassan is a troubling new viral tick-borne disease.
According to the CDC, it takes anywhere from about seven to 30 days after being bitten by a tick carrying the Powassan virus for symptoms to begin.
Powassan virus can attack the nervous system, causing encephalitis (brain inflammation) and meningitis (inflammation of the membranes around the spinal cord).
- loss of coordination
- trouble speaking
About half of those who survive a Powassan infection have permanent health issues such as recurrent headaches, muscle wasting and memory problems.
There are no medications (antibiotics don’t work on viruses) to treat it or vaccine to prevent infection. Since there is no treatment, the best way to protect is to follow the CDC recommendations:
- Avoid contact with ticks
- Walk in the center of trails or paths through woods or tall grasses
- Use insect repellent
- Bathe or take a shower as soon as possible after coming indoors (preferably within two hours) to wash off and more easily find ticks that are crawling on you.
- Check your whole body for ticks and use a mirror to check your back, neck, under the arms, in and around the ears, inside the belly button, behind the knees, between the legs, around the waist, and especially in your hair or on your head.
- Check pets, coats, backpacks, etc. as ticks can come into the house on them and attach to a person later.
- Put clothes in a dryer on high heat for 10 minutes to kill ticks on dry clothing. |
- slide 1 of 3
Effective use of differented instruction often comes down to student engagement. If students are not being taught in a way that allows them to easily process the information, then you are going to lose their interest and they will no longer be engaged in what you are doing. Once they are bored or distracted, the learning ends.
- slide 2 of 3
What Differentiated Instruction Does Not Mean
It’s important to get a firm grasp on what differentiated instruction is and what it is not if you want to successfully implement it in your classroom. Let’s take a look at what it is not as this is where I see most teachers making their mistakes. Repetition of the same concept the same way is not differentiated instruction. Repeating something LOUDER and SLOWER is not different.
A good way to remember this is to think about a person trying to communicate in a language they are not fluent in. I’ve had the unique opportunity to spend time overseas studying various languages. One of the most frustrating moments for a language learner is when you explain to somebody that you don’t understand and they respond by repeating the exact phrase louder and slower. In your head you think “umm… I just said I don’t understand that".
Unless they explain it using different terminology (hopefully with words you know) you will never understand what they said. After all, you don’t know the words they are using. The fact that they repeat the phrase 5 times won’t change the fact that you don’t know what those words mean. You won’t magically understand the words the 5th time they say them either. The only way you will understand what they are trying to communicate is if they use different words (or add some hand motions) to convey the same meaning.
This is the frustration your students can feel when you teach the same concept in basically the same way. If they don’t understand it the first time (or the second time) then you need to find a creative way to teach it differently. Louder and slower isn’t different. It will do nothing for them to repeat what you said the same way.
- slide 3 of 3
What Effective Instruction Looks Like
For differentiated instruction to be effective, start with the concept you are trying to teach and then think of as many ways as possible that you can teach the concept. Try to embed a few of those different methods into one lesson and you will have better results. Don’t be a lazy teacher and assume because you taught it one way, everybody got it.
The most important element of differentiated instruction is engagement. Are the students engaged in what you are doing or are you talking to a group of students who are not mentally in your class? Boredom is the enemy of learning. Students may physically be in your class, but if they’re not paying attention the battle is lost. Focus on using differentiated instruction to increase student engagement and you will find that the more students are engaged, the more they learn and retain. Differentiated instruction is about making connections in their little heads.
Could you use a manipulative to help explain a concept? What about using technology? Maybe you could play a game that would teach students a concept while they are having fun. How about a story? Stories are fantastic… if they have a purpose. I love telling stories because if they are interesting students are engaged and when they have a concept attached to them, students remember the concept. Please don’t be the teacher who tells stories just to pass the time.
Remember that not every child will learn the same way and louder and slower is just what it is… louder and slower, NOT different. Different is different. Also be aware that differentiated instruction is not going to work if you are just winging it. You need to plan out the lesson methodically with different instructional methods embedded in the lesson. The goal outcome is that when you are done with a lesson (filled with different learning styles) most of your students will understand the concept. The reason most teachers end up simply being louder and going slower is because they didn’t spend time planning like they should have. |
By Dr. David Wartinbee, for the Redoubt Reporter
At this time of the year in Alaska, a drive of more than a couple hundred miles will involve some time during darkness. While heading north to visit friends during the holidays, I spotted a small, bright spot in the roadway ahead.
As my lights got closer, a huge, brown ungulate appeared surrounding that tiny light spot. I slowed appropriately. A few miles farther down the road, a pair of bright spots appeared on one side of the road. A second later I was able to see the faintly lit image of a lynx crossing the road. I had first seen both of these animals because of their tapetum lucidum reflecting my headlight illumination.
While many are familiar with the phrase, “A deer-in-the-headlights look,” not as many may realize there is an interesting anatomical basis for this situation. Most nocturnal animals, like dogs, cats, deer, etc., will demonstrate “eye shine” when a bright light is shown on them at night. What happens is the light entering the animal’s eyeball is being reflected right back at us as if there were a mirror in there. The mirror analogy is actually pretty close to what is happening.
In order to understand how the tapetum lucidum works, we have to know a little about the layers inside the eyeball itself. First, the retina is the thin, innermost layer of the eye and it contains the light-sensitive cells called rods and cones, and lots of blood vessels. In very close proximity to the rods and cones is a black layer called the choroid.
The important choroid layer absorbs light that has just passed by the light-sensitive
rods and cones. In humans that do not have a heavily pigmented choroids, like albinos, to absorb the passing rays, light gets reflected and scattered inside the eyeball. These individuals suffer with visual difficulties and even small amounts of light are blindingly bright.
In nocturnal animals with a tapetum lucidum, the choroid, or a special portion of the retina, will act as a slight reflector. The actual tapetum lucidum can vary in its composition depending on the specific animal. Since there are so many different animals that exhibit “eye shine,” it is easy to understand that there are many different kinds of reflective layers.
In some, it is composed of a special layer of iridescent crystals like guanine, or in others it might be a layer of cells with reflective fibers.
No matter how the reflection by the tapetum is accomplished, the incoming light is reflected right back past the very rods and cones that it originally passed. This essentially gives the rods and cones a second chance to detect the same light rays. That simple reflection greatly enhances night vision.
Also, by reflecting the light exactly back from where it came, the animal is able to create a crisp visual image rather than getting a blurry image that would occur if the light scattered randomly within the eyeball. It is believed that cats can see about nine times better at night than we can, since they have a tapetum and we do not.
The color of the reflective “eye shine” will vary according to the animal. Many reptiles
show bright red eye shine, while mammals vary from yellow, white, blue and green. There are variations even within the same species and there are lots of examples of one eye reflecting back one color while the other eye reflects back a different color. Along with birds, some fish, like walleye, have a tapetum.
Most primates — like humans — pigs, kangaroos and other day-active animals do not have a tapetum lucidum. Accordingly, our night vision is mediocre compared to those animals that are active at night.
Humans can produce a confusing situation known in the photography arena as “red eye.” This occurs when a flash of light illuminates the blood vessel-rich retina in the back of the eye and the eyes appear to be red. There is no tapetum involved here, just illumination of blood vessels. If the source of the flash were somewhere other than on the camera, there would be no “red eye.”
Imagine how our flash pictures might look if we had chartreuse-colored blood?
Another unusual situation in humans and some animals is the white glow that can appear in the eyes. This “eye glow” occurs when there are cataracts. The glow is caused by illumination of the crystals embedded within the lens of the eye and, again, is not caused by a tapetum.
Moose certainly have a tapetum lucidum, but I have wondered why we don’t often see the same bright headlight reflection from moose eyes that can be seen from smaller animals like dogs or cats. The answer probably comes from several different reasons.
First, moose are large animals and their eyes are often held above the level where our headlights are aimed. Because a moose’s eyes are on extreme sides of its head, it is difficult to see both of their eyes at the same time. So we most commonly get a reflection from only one eye at a time.
I have not been able to find much documentation on the size of a moose tapetum compared with other animals. However, after shining a bright flashlight beam at a moose from various angles, I have discovered that the tapetum in a moose’s eye is mostly in the very back of the eyeball.
When the moose is at right angles to you, your lights are not striking the tapetum, and you only get a slight “red-eye” reflection.
Only when the moose is looking directly at you, and they don’t do this all that often, will you see the bright, two-eyed reflection.
So, as a moose crosses the road, you and I get a single, slight reddish glow from an eye that is not reflecting back much light from our headlights. No wonder we don’t easily see that moose crossing up ahead.
The next time your lights fall on an animal and you see the distinctive “deer-in-the-headlights” reflection, you will know that particular animal is normally active at night. You’ll also know they have a microscopically thin tapetum lucidum in the back of their eyeball that aids in their night vision.
David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the ecology of the Cook Inlet watershed. |
It appears sea urchins might just use their entire body as one huge eye. Previous research has shown certain marine invertebrates react to light even without apparent “eyes” leaving scientists to wonder how did they see but new research suggests sea urchins may have light-sensitive cells throughout their feet behaving much like one giant eye.
Genetic analysis of the California purple sea urchin had already yielding data showing a large amount of their genes were linked with what is found in the development of retinas — the light-sensitive tissue in the inner eyeballs of humans and other invertebrates. And other research has suggested urchins might have a spattering of light-receptor cells all over its body that collectively act much like a retina.
But recent research has found that there are two distinct groups of light receptor cells are found concentrated at the base and tips of the urchins’ feet. Considering there are over 1,400 feet on the California purple urchin, the research team speculate urchins use these multitude of tube feet as retinas and the rest of their bodies to shield against the extra incoming light allowing them to have some form of “vision.”
Since previous work discovered the number and placement of spines on a sea urchin can affect how sharp its vision might be, the new data definitely helps support the theory that the entire body of sea urchins just may in fact act as one massive eyeball.
The sea urchin-eye study appeared May 2 in the journal Proceedings of the National Academy of Sciences. |
Anaerobic exercise is an exercise intense enough to trigger lactic acid formation. It is used by athletes in non-endurance sports to promote strength, speed and power and by body builders to build muscle mass. Muscle energy systems trained using anaerobic exercise develop differently compared to aerobic exercise, leading to greater performance in short duration, high intensity activities, which last from mere seconds to up to about 2 minutes. Any activity lasting longer than about two minutes has a large aerobic metabolic component.
Anaerobic metabolism, or anaerobic energy expenditure, is a natural part of whole-body metabolic energy expenditure. Fast twitch muscle (as compared to slow twitch muscle) operates using anaerobic metabolic systems, such that any recruitment of fast twitch muscle fibers leads to increased anaerobic energy expenditure. Intense exercise lasting upwards of about four minutes (e.g., a mile race) may still have a considerable anaerobic energy expenditure component. Anaerobic energy expenditure is difficult to accurately quantify, although several reasonable methods to estimate the anaerobic component to exercise are available.
In contrast, aerobic exercise includes lower intensity activities performed for longer periods of time. Activities such as walking, long slow runs, rowing, and cycling require a great deal of oxygen to generate the energy needed for prolonged exercise (i.e., aerobic energy expenditure). In sports which require repeated short bursts of exercise however, the anaerobic system enables muscles to recover for the next burst. Therefore training for many sports demands that both energy producing systems be developed.
There are two types of anaerobic energy systems: 1) the high energy phosphates, ATP adenosine triphosphate and CP creatine phosphate; and 2) anaerobic glycolysis. The high energy phosphates are stored in very limited quantities within muscle cells. Anaerobic glycolysis exclusively uses glucose (and glycogen) as a fuel in the absence of oxygen or more specifically, when ATP is needed at rates that exceed those provided by aerobic metabolism; the consequence of rapid glucose breakdown is the formation of lactic acid (more appropriately, lactate at biological pH levels). Physical activities that last up to about thirty seconds rely primarily on the former, ATP-CP phosphagen system. Beyond this time both aerobic and anaerobic glycolytic metabolic systems begin to predominate.
The by-product of anaerobic glycolysis, lactate, has traditionally been thought to be detrimental to muscle function. However, this appears likely only when lactate levels are very high. Elevated lactate levels are only one of many changes that occur within and around muscle cells during intense exercise that can lead to fatigue. Fatigue, that is muscular failure, is a complex subject. Elevated muscle and blood lactate concentrations are a natural consequence of any physical exertion. The effectiveness of anaerobic activity can be improved through training.
- What is Anaerobic Exercise?
- Medbo, JI; Mohn, Tabata, Bahr, Vaage, Sejersted (January 1988). "Anaerobic capacity determined by maximal accumulated O2 deficit". Journal of Applied Physiology 64 (1): 50–60. Retrieved 14 May 2011.
- Scott, Christopher B (June 2005). "Contribution of anaerobic energy expenditure to whole body thermogenesis". Nutrition & Metabolism. 14 2. doi:10.1186/1743-7075-2-14. Retrieved 14 May 2011.
- Di Prompero, PE; G. Ferretti (Dec 1, 1999). "The energetics of anaerobic muscle metabolism". Respiration Physiology 118 (2-3): 103–115.
- Scott, Christopher B (2008). A Primer for the Exercise and Nutrition Sciences: Thermodynamics, Bioenergetics, Metabolism. Humana Press. p. 166. ISBN 978-1-60327-382-4.
- Anaerobic training
- McMahon, Thomas A (1984). Muscles, Reflexes, and Locomotion. Princeton University Press. pp. 37–51. ISBN 0-691-02376-X. |
|Codeforces Round #375 (Div. 2)|
Modern text editors usually show some information regarding the document being edited. For example, the number of words, the number of pages, or the number of characters.
In this problem you should implement the similar functionality.
You are given a string which only consists of:
It is guaranteed that each opening parenthesis has a succeeding closing parenthesis. Similarly, each closing parentheses has a preceding opening parentheses matching it. For each pair of matching parentheses there are no other parenthesis between them. In other words, each parenthesis in the string belongs to a matching "opening-closing" pair, and such pairs can't be nested.
For example, the following string is valid: "_Hello_Vasya(and_Petya)__bye_(and_OK)".
Word is a maximal sequence of consecutive letters, i.e. such sequence that the first character to the left and the first character to the right of it is an underscore, a parenthesis, or it just does not exist. For example, the string above consists of seven words: "Hello", "Vasya", "and", "Petya", "bye", "and" and "OK". Write a program that finds:
The first line of the input contains a single integer n (1 ≤ n ≤ 255) — the length of the given string. The second line contains the string consisting of only lowercase and uppercase English letters, parentheses and underscore symbols.
Print two space-separated integers:
In the first sample, the words "Hello", "Vasya" and "bye" are outside any of the parentheses, and the words "and", "Petya", "and" and "OK" are inside. Note, that the word "and" is given twice and you should count it twice in the answer. |
The human body has certain chemicals called hormones that serve as the body’s messengers. Endocrine glands are specialized glands that release these chemicals. The body contains many of these endocrine glands. The way hormones work has a big impact on the human body.
These hormones play a role in the regulation of a variety of physiological functions as well as human physical health. Here, we’ll go into great detail regarding hormones and their functions i.e. how they work in the body. Additionally, we’ll discuss how hormones and endocrine glands interact.
Endocrine Glands and Hormones
The hormonal system, also known as the endocrine system, is a reticulation of glands in the body that produces hormones that let cells communicate with one another. They control nearly every cell, organ, and bodily function. Your body may experience a number of health issues if your endocrine system is not functioning properly.
Endocrine glands and hormones are interconnected. Hormones act as the body’s transmit system. They use signals from one area of the body to direct another area to execute essential action. The endocrine glands play a role in many different bodily processes, including growth, weight gain, reproduction, metabolism, and other functions. Here is the list of major glands:
- Pineal gland
- Hypothalamus Pituitary gland
- Adrenal glands
- Thyroid gland
The base of the human brain contains the hypothalamus, which links the brain and the hormone system. They connect the neuronal and hormonal systems with the hypothalamus. Its hormones maintain the body’s balance.
They have an impact on the body’s reaction to illness, mood, memory, appetite, sex drive, alertness, body weight, blood pressure, heart rate, and more. The endocrine system and hormones impact the body’s functions as well as psychological functions. Here is the list of the major hormones:
- Luteinising hormone
- Follicle-stimulating hormone
- Thyroid-stimulating hormone
- Antidiuretic hormone
- Corticotropin-releasing hormone
The pituitary gland is the body’s endocrine system’s major gland. Using the information received from the brain it instructs other glands in the body. This gland produces a number of crucial hormones, such as prolactin, a growth hormone, which aids lactating mothers in producing milk. Another hormone is the antidiuretic hormone, which controls blood pressure and aids in controlling the body’s water balance by acting on the kidneys.
The thyroid gland produces thyroid hormone, which regulates your metabolism and growth. Everything moves more slowly if this gland doesn’t produce enough, and your heart rate may also slow down. You can develop constipation or put on weight. On the other hand, when it performs too much, everything accelerates.
For example, your heart may beat more quickly, you might begin to lose weight. The hormone calcitonin, which is also produced by the thyroid gland, may contribute to stronger bones by facilitating calcium absorption into the bone.
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Adrenal Gland is crucial for the production of epinephrine, commonly known as adrenaline, the hormone associated with fight. Additionally, both of these glands produce corticosteroid hormones. Among other things, they have an impact on your heart rate, oxygen intake, metabolism, blood flow, sexual function, etc.
The pineal Gland is a small gland located close to the brain’s centre. It produces melatonin, a key hormone that aids in sleep.
T-lymphocytes, a type of white blood cell that fights infection, are produced by this specific thymus gland. The thymus gland starts to decrease after puberty.
Hormones and their functions
The human body has various types of hormones and their functions are different in the body. As a messenger that is released into the blood, hormones work. They are carried by the blood to the body’s many organs and tissues. Hormones bind to the receptors once they have reached their target spot. A number of significant functions of hormones are:
- Hormones control mood and cognitive functions
- They contribute to growth and development
- They contribute to food metabolism
- In order to maintain the temperature of the body, hormones help.
- Hormones control thirst as well as hunger
- They maintain sexual development
The hormones are classified into three main types that are based on their chemical structure. They include Lipid-Derived, Peptide, and Amino Acid-Derived hormones. Some significant hormones in human body and their functions are described below:
The thyroid gland basically releases two hormones Triiodothyronine and Thyroxine, and they are called thyroid hormones. These hormones aim in regulating your body’s metabolism.
Growth hormone is essentially a protein hormone with amino acids that is generated as well as secreted by the anterior pituitary cells. It promotes metabolism-boosting growth and cell regeneration.
A protein called prolactin hormone is effective for helping mammals create milk. It affects more than 300 different processes in men and animals.
Luteinizing hormone is a certain hormone released by the anterior pituitary gland that promotes both female ovulation and male androgen synthesis.
The posterior pituitary releases oxytocin, a peptide hormone and neuropeptide that is typically made in the hypothalamus. It contributes to social interaction, reproduction, etc.
Insulin hormone, which is produced by the pancreas, helps the body turn glucose from food into energy.
The thyroid gland releases the hormone thyroxine, which aids in regulating the human body’s metabolism.
The parathyroid glands produce the hormone parathyroid. Your neck contains four small glands. This hormone regulates the volume of calcium in your blood.
Salt and water balances are regulated by a group of steroid hormones known as mineralocorticoids. The most important mineralocorticoid is aldosterone. The body’s sodium and potassium transport is aided by the hormone mineralocorticoids.
Steroid hormones known as glucocorticoids are extensively utilized to treat cancer, inflammation, and autoimmune disorders.
Sex hormones are called steroid hormones. Its work is to communicate with vertebrate steroid hormone receptors.
Certain neurons are present in the central nervous system as well as medulla of the adrenal gland. They secrete the hormone adrenaline. It is sometimes referred to as an emergency hormone since it triggers a rapid response that causes people to act and think swiftly under pressure.
There are many more hormones and their functions that are observed differently. If there is any disturbance in hormones, various symptoms will arise in the body. Healthy hormones lead to the good functioning of every organ of the body. Treatments also apply to hormone problems. |
When it comes to raising children, our main goal is to help them grow into well-rounded individuals who can navigate through life successfully. One crucial aspect of their development is encouraging creativity, as it helps foster their imagination and problem-solving skills. But how can we unleash their creativity and allow it to flourish? The answer lies in the power of play.
Play is not just a way to keep children entertained; it is a fundamental part of their development. Through play, children learn how to express themselves, explore their surroundings, and make sense of the world around them. It allows them to experiment, take risks, and discover new things. So, instead of dismissing play as mere child’s play, let’s acknowledge its importance and make it a priority.
But what exactly is the power of play? It is the ability to ignite a child’s imagination, promote problem-solving skills, and enhance their emotional development. When children engage in pretend play, they create magical worlds where anything is possible. They become the main characters in their stories, making decisions, and taking on different roles. This form of play not only gives them a sense of control but also allows them to be creative and think outside the box.
By providing children with open-ended toys and materials, we give them the opportunity to use their imagination and think critically. Building blocks, art supplies, and dress-up clothes are all great examples of toys that encourage creativity. These types of toys don’t come with a set of rules or limitations, allowing children to play freely and explore their ideas. As parents, we can also participate in their play by asking open-ended questions and engaging in imaginative play with them. This not only strengthens our bond with them but also supports their creative development.
Another way to encourage creativity in children is by creating a safe and supportive environment. When children feel secure and validated, they are more likely to take risks and express their ideas. Instead of dismissing their imaginative play as silly or unimportant, we should praise and encourage their efforts. By doing so, we empower them to believe in themselves and their creative abilities.
Furthermore, allowing children to have unstructured free playtime is essential for their creative development. In today’s fast-paced world, children are often overscheduled with structured activities and classes, leaving little time for them to play freely. We need to provide them with the necessary space and time to explore, invent, and create on their own terms. This unstructured playtime allows them to practice problem-solving skills, think critically, and collaborate with others.
Moreover, technology has become an integral part of our lives, and children are growing up in a digital age. While technology can be a valuable learning tool, it should not replace the power of play. We need to find a balance that allows children to explore the virtual world while also engaging in hands-on, imaginative play. Limiting screen time and encouraging outdoor play can help children connect with nature and develop their creativity in a more holistic way.
Fostering Creativity Through Arts and Crafts
Art is a powerful tool for nurturing creativity in children. Whether it’s painting, drawing, or sculpting, artistic activities allow children to express themselves and explore their ideas. By providing them with various art supplies and materials, we give them the freedom to experiment and create. We can also introduce them to different art techniques and styles, exposing them to a wide range of artistic possibilities.
One way to foster creativity through arts and crafts is by encouraging children to tell stories through their artwork. By asking questions about their artwork, we can prompt them to think deeper and expand on their ideas. This not only helps them develop their storytelling skills but also allows them to connect their creativity with their emotions and experiences.
In addition to traditional art activities, we can also encourage children to engage in DIY projects. These projects allow them to problem-solve, think critically, and use their creativity to create something tangible. From building a birdhouse to designing their own board game, the possibilities are endless.
By providing them with tools and materials, we show them that their ideas are valuable and that they have the power to bring them to life.
The Role of Imagination in Creativity
Imagination is the key ingredient to creativity, and it is our role as parents to nourish and cultivate it. We can do this by providing children with opportunities to engage in imaginative play. Pretend play, dress-up, and storytelling are all great ways to ignite their imagination and creativity.
Furthermore, we can expose children to different forms of storytelling, such as reading books, watching movies, or visiting museums. These experiences not only expand their knowledge but also inspire them to create their own stories. By encouraging them to write, draw, or act out their stories, we help them develop their narrative skills and boost their creative thinking.
In today’s digital age, we can also harness the power of technology to stimulate imagination and creativity. There are countless apps and websites that offer interactive storytelling experiences, allowing children to explore different worlds and characters. By engaging in these digital storytelling platforms, children can develop their storytelling skills and create their own digital narratives.
Encouraging Creativity through Play-Based Learning
Play-based learning is an approach that combines play and educational activities to promote children’s development. It allows children to learn and explore while also fostering their creativity. By integrating play into educational settings, we can make learning more enjoyable and engaging for children.
One way to encourage creativity through play-based learning is by implementing project-based activities. These activities allow children to work on long-term projects, which require them to plan, design, and create something of their own. Whether it’s building a model of a city or creating a stop-motion animation, these projects give children the freedom to use their creativity and problem-solving skills.
Furthermore, incorporating games into educational settings can also enhance children’s creativity. Educational games provide a fun and interactive way for children to learn and think critically. From puzzle-solving games to logic games, these activities challenge children’s minds and encourage them to come up with creative solutions.
Supporting Creativity through Play in Nature
Nature has always been a source of inspiration for creativity. The sights, sounds, and textures of the natural world awaken our senses and stimulate our imagination. Therefore, it is essential to provide children with opportunities to play in nature and explore its wonders.
Outdoor play allows children to engage in unstructured play, where they can freely explore their environment and connect with nature. By providing them with natural materials like rocks, leaves, or sticks, we give them the tools to create their own imaginative play experiences. Whether it’s building a fort, creating a nature collage, or pretending to be explorers, these outdoor activities foster their creativity and sense of wonder.
Moreover, nature provides endless possibilities for children to engage in sensory play. From splashing in puddles to playing with sand and mud, these sensory experiences stimulate their senses, spark their creativity, and promote their emotional well-being. By allowing them to get messy and explore with their hands, children can fully engage with their surroundings and express themselves through play.
Nurturing Creativity through Music and Movement
Music and movement are powerful tools for nurturing creativity in children. They allow children to express themselves, connect with their emotions, and engage their imagination. By incorporating music and movement into their daily lives, we can provide them with a rich sensory experience that nurtures their creative development.
One way to nurture creativity through music is by encouraging children to create their own songs or melodies. By providing them with simple musical instruments or even everyday objects that make sounds, we allow them to experiment and compose their own music. This not only stimulates their auditory senses but also boosts their creative thinking and self-expression.
Furthermore, we can encourage children to engage in creative movement activities, such as dancing or yoga. These activities not only promote physical well-being but also allow children to express themselves through movement and connect with their bodies. By providing them with a safe and supportive environment to explore different movements, we empower them to be creative and imaginative.
Building a Creative Mindset
Nurturing creativity in children is more than just providing them with artistic activities or play opportunities. It is about building a creative mindset that they can carry with them throughout their lives. By fostering their confidence, resilience, and curiosity, we empower them to think creatively and embrace challenges.
We can build a creative mindset by encouraging children to take risks, make mistakes, and learn from them. Instead of focusing on the outcome, we should praise their effort and persistence. By doing so, we teach them that creativity is not about being perfect but about embracing the process and being open to new ideas.
In conclusion, the power of play in encouraging creativity in children’s development is undeniable. By providing them with open-ended toys, a safe and supportive environment, and opportunities for unstructured playtime, we allow their imagination to soar. Through arts and crafts, imaginative play, play-based learning, outdoor play, and music and movement, we can nurture their creativity and help them build a creative mindset that will serve them well in all aspects of their lives. |
The Status and Trends range maps show a species’ range in each season stacked on top of each other to illustrate the boundaries of a species—how far east or west or north or south a species is known to occur throughout the year. These range maps are based on analytical results powered by eBird sightings and are light years ahead of the range maps found in traditional field guides that provide a coarse overview of a species’ range. Before citizen science projects, such as eBird, ornithologists relied on expert opinion to create range maps for field guides. While the experts consulted knew a lot about when and where each species occurred, they could not be everywhere. Now thanks to eBirders who have shared their sightings of birds around the world and new statistical modeling techniques, range maps are more accurate than ever.
Fork-tailed Flycatchers sally over grasslands and open areas from southern Mexico to Argentina. Traditional range maps show these dramatic birds occurring throughout much of the Amazon during the non-breeding season. But the new analytical range maps show that Fork-tailed Flycatchers only migrate through the Amazon and instead use open areas along the Amazon River and its tributaries year-round.
The analytical powered range maps also highlight patterns across the entire species’ range. The Common Firecrest spans all of Europe to Asia Minor and Northern Africa. These new range maps reveal fine-scale relationships with topography and emphasize seasonal patterns of occurrence in great detail.
Range maps powered by eBird data can also be used to improve your birding. Not only do these maps help you find out when and where to go looking for your favorite bird, they also show you the extent of a species range throughout the year. A good reminder that your favorite birds are not only affected by actions in your backyard but also by what happens in locations where they stop during migration and on the wintering grounds.
The range map depicts the boundary of the species’ range, defined as the areas where the species is estimated to occur within at least one week within each season. Purple indicates locations where the species is present year-round, red indicates the breeding season, blue indicates the non-breeding season, and yellow indicates locations where the species is present during the pre-breeding and post-breeding seasons. Areas of light gray indicate species absence (or very rare occurrence). Areas of darker gray indicate areas in which predictions could not be made due to a lack of data. |
What are Digenetic flukes?
The digenetic flukes include blood flukes and schistosomes that are generally considered to be the most serious helminthic human parasite. See Classification; schistosomiasis.
What is the difference between Monogenetic and Digenetic flukes?
– Additionally, if an organism can complete its life cycle inside a single host it is termed as monogenetic while if an organism utilises two host organisms for completing its life cycle it is termed as digenetic organisms. – Liver flukes spend their life cycle utilising two hosts.
What is the most common 1st intermediate host among Digenetic trematodes?
As many as three intermediate hosts and a single definitive host may be required to complete a digenetic trematode life cycle. The first intermediate host is typically a gastropod (snail). The definitive host is always a vertebrate.
What is Digenetic nematode parasite?
Digenic trematodes are unsegmented, leaf-shaped worms that are flattened dorsoventrally. They bear 2 suckers, one surrounding the mouth (oral sucker) and another on the ventral surface of the body (ventral sucker). These serve as the organs of attachment. The sexes of the parasites are not separate (monoecious).
What is Digenetic?
Definition of digenetic : of or relating to a subclass (Digenea) of trematode worms in which sexual reproduction as an internal parasite of a vertebrate alternates with asexual reproduction in a mollusk.
Which of the following is Digenetic parasite?
Solution : The parasites which complete their life cycle in the body of two hosts are called digenetic parasites. Example : Liver fluke (Fasciola hepatica) completes its life cycle in sheep and snail.
What is Monogenetic and Digenetic parasite?
Monogenetic parasites are the parasites that complete their life cycles in one host only. Digenetic parasites are those that need more than one host (usually two) to complete their life cycles.
Is fasciola a Monogenetic or Digenetic trematode?
The adult form of the fasciola hepatica is seen in the vertebrate host and larval stages are seen in the invertebrate host and it mainly lives in the bile duct of the sheep. That is the reason why the fasciola hepatica is called a digenetic endoparasite.
What is Digenetic parasite give an example?
Solution : The parasites which complete their life cycle in the body of two hosts are called digenetic parasites. Example : Liver fluke (Fasciola hepatica) completes its life cycle in sheep and snail. Loading Books. × Question Details till 01/06/2022.
Which of these is a Digenetic?
Taenia solium, Fasciola hepatica and Taenia saginata all have digenetic life cycles. Hence, option D is correct.
Is Entamoeba a Digenetic parasite?
Thus, it is also digenetic. > Entamoeba histolytica is a protozoan parasite that is responsible for a disease known as amoebiasis. It occurs usually in the large intestine of humans.
Which of the following is a Digenetic parasite? |
|Breast cancer cells |
Image Credit: Anne Weston - Francis Crick Institute (CC BY-NC 4.0)
Tumors are complex entities made up of many types of cells, including cancer cells and normal cells. But even within a single tumor there are a diverse range of cancer cells – and this is one reason why standard therapies fail.
When a tumor is treated with anti-cancer drugs, cancer cells that are susceptible to the drug die, the tumor shrinks and the therapy appears to be successful. But in reality, a small number of cancer cells in the tumor may be able to survive the treatment and regrow, often more persistently, causing a relapse.
In a study published in eLife, scientists from Professor Greg Hannon’s IMAXT lab at the Cancer Research UK Cambridge Institute at the University of Cambridge have developed a new technique for identifying the different types of cells in a tumor. Their method – developed in mouse tumors – allows them to track the cells during treatment, seeing which types of cells die and which survive.
The IMAXT team was previously awarded £20 million by Cancer Grand Challenges, funded by Cancer Research UK.
Dr Kirsty Sawicka from the Cancer Research UK Cambridge Institute said: “Tumors are incredibly complex, made up of many different types of tumor cells that have acquired genetic mutations as they evolve and replicate – and some of these cells are able to evade standard cancer treatments. Until now, it hasn’t been possible to work out which these cells are and what makes them special, but our technique means that we can now do just that.”
The team used viruses to tag different types of breast cancer cells with a unique genetic ‘barcode’. They then formed tumors from these cells in mice and treated them with the same drugs used to treat patients with breast cancer.
By scanning the barcodes using recently developed single cell sequencing technologies – which look for those genes that are turned on or off in the cell – they were able to identify the different types of cancer cells, how many of those cells there are and what their characteristics are – and which types of cancer cells are not killed effectively by standard treatments.
The team noticed that the cells that evade chemotherapy are those that have a greater reliance on asparagine, an amino acid that cells use to protect themselves from damage. By then administering L-asparaginase – a drug currently used to treat patients with acute lymphoblastic leukemia, which breaks down asparagine – they were able to specifically target and kill these tumor cells.
Dr Ian Cannell from the Cancer Research UK Cambridge Institute said: “Offering some kind of ‘combination therapy’ that adds asparaginase to the standard treatment could be a way of further shrinking tumors in breast cancer patients and reducing their risk of relapse.
“Although we see evidence that these evasive tumor cells are increased in patients after chemotherapy, so far, we’ve only shown that we can target them in mice, so there’s still a long way to go before it leads to a treatment for patients. Before we can do that, we need to find the best way of administering the drugs – would we give the drugs together, for example, or offer the standard treatment and then asparaginase.”
David Scott, Director of Cancer Grand Challenges, Cancer Research UK, said: “Incredible innovations like these are exactly why Cancer Grand Challenges was created. Ambitious ideas from world class scientists – like tracking how individual cells respond to cancer treatments – are what will give us the much-needed insights to bring us the more effective cancer treatments of tomorrow and make real differences to patients.”
Published in journal: journal eLife
Source/Credit: University of Cambridge
Reference Number: med122022_01 |
By reading to your child — even after they can read on their own — and talking about the books you share together, you are sending a signal that reading is important. Like any conversation, talking about books can happen anywhere and at any time (in the car, at bedtime or at tea-time for example). Books can generate feelings that need to be shared. A great way to start a conversation about reading is to bring up what you have read and how it made you feel. Then invite your child to do the same.
There are many different skills that a child will need to develop in order to become a good reader. These include:
- using sounds to decode unfamiliar words (phonics)
- recognising words by sight
- knowing how to read a book (e.g. reading from left to right and from the top to the bottom of the page or, when they are older, using the contents, glossary and index pages)
- having some background knowledge about the themes in a book
- having a suitable vocabulary (understanding or working out what individual words mean)
- using the punctuation and recognising the grammar
- reading with confidence and smoothness (also known as being ‘fluent’)
- being prepared to think about and question what the author is trying achieve.
A child will need all these skills, to a greater or lesser extent, before they can understand a book, or a passage from a book. These skills are what teachers are referring to when they talk to you about your child’s ‘reading comprehension’.
So what does a ‘good’ reader look like?
Trying to help a child who is just starting to read get to know their letters and words can be a daunting task – and it's only the first step to becoming a good reader. Children learn to read in the same way as they learn to speak. Do you remember when your child first started speaking? Did they have a difficult time pronouncing their Ls and THs? Of course, almost every child does. But by practising and observing you, many children are well on their way to becoming excellent little speakers by the time they start school. Children learn to read in the same way that they learn to speak. It's an adult’s job to provide children with opportunities to practise their reading and to set an example so that their children become as fluent with reading as they are with speaking.
Being a fluent reader is about reading aloud without difficulty. It is about reading with expression and emphasis (not reading like a robot). It is about reading at a good pace (not too fast and not too slow), reading accurately and paying attention to the punctuation. Children cannot achieve fluency until they are able to use phonics skills automatically and when they can sight-read many of the words in their book. Without fluency it is difficult to understand what you are reading or to explain to others something about what you have just read.
Please spend a few minutes looking at the following video of a teacher reading with a child who is on the way to becoming a fluent reader. The child reads with expression and at a good pace. She is reading accurately and paying attention to the punctuation. She is being encouraged to think about what she is reading, predict what will happen next and talk about the story. Most importantly, they are both enjoying the experience. If you don’t show your child that you enjoy reading, how will your child ever learn to enjoy it?
It is important to make sure your child is reading a text at the right level if you want to make them into a fluent reader. If a text is too hard, they will spend too much time trying to sound out words and may even get stuck on some of the more difficult words. This will hinder their fluency. Typically, if a child misreads or has to sound-out more than 1/10 words, they will not be able to focus on their fluency.
How can you tell if your child is reading fluently? As yourself the following questions:
- Do they struggle to sound out words?
- Do they get ‘stuck’ on words?
- Do they read hesitantly?
- Do they need to use a lot of effort in order to read their book?
- Do they read a list of words rather than try to read a whole sentence before pausing?
- Do they correct themselves when they make a mistake and the sentence they have just read doesn’t make sense?
- Do they read without any expression?
If the answer to any of these questions is yes, then your child has not yet achieved fluency in their reading. So what now? Here are some tips and strategies that may help you to improve your child's reading fluency.
Model fluent reading
Has your child's teacher every told you to spend time reading to your child, and not just having your child read to you? This is why... children need to hear fluent reading in order to achieve their own fluency. Hearing an adult read smoothly and easily provides a model for how a child should be reading. As your child hears you smoothly and easily pronounce words, pause after commas, and stop when there is a full stop, they'll start doing the same. Reading to your child also exposes them to expressive reading. As you emphasise the emotion of the text you're reading, your child will catch on and begin doing the same as they read. Being a model reader for your child is key to helping them achieve fluency.
Echo reading is a form of modelling where you read a sentence to your child and they read it back to you. Echo reading helps children begin to recognise words and anchor important words in their vocabulary. As your child reads a passage back to you, it may be helpful to run his or her his finger under the words as s/he reads them. This ensures that your child recognises the words and isn't just regurgitating what s/he heard you say. As your child gets better at reading a sentence back to you, you'll want to increase the number of sentences they echo.
Practice Makes Better
Fostering reading fluency requires lots of practise. The best readers weren't born that way. They achieved fluency through repeated, consistent practise. The ultimate goal of reading fluency is to be able to read effortlessly. To be able to read effortlessly requires a great deal of effort over a long period time!
We would recommend reading the same passage aloud three times until fluency is achieved. Reading the same passage again and again will provide your child with the recognition and repetition needed to reach fluency. Start by reading a short passage (no longer than 100 words) aloud to your child. Then have your child read the same passage back to you, repeating this until it becomes effortless for them.
Memorising Can Help
As your child works towards reading fluency, have them memorise some short stories, nursery rhymes or poems. Having your child memorise sentences and short passages will achieve three things. First, memorising will allow your child to become very familiar with specific words that they'll easily recognise in future reading. Second, as your child memorises passages, they will learn the rhythm of written language. Achieving fluency with just a few sentences will empower them to achieve fluency with paragraphs and then longer passages. Finally, memorisation helps beginning readers feel like they're a success. And success engenders success. Once your child has memorised a few short passages, they'll immediately begin feeling like a fluent reader.
Keep It Fun
While practise, repetition and memorising are vital to achieving fluency, if reading turns into an arduous, painful experience for your child, they're likely to rebel. As you work towards improving your child's fluency, don't stick to a fixed routine. Mix it up a little and keep it fun. Incorporating games, activities and a little friendly competition into your reading will make it something your child enjoys. The following are just a few ideas for keeping your child's reading fun and engaging:
- Have your child pick the story or passage s/he wants to read.
- Act out what the characters are saying as you read using different voices and emotions.
- Help your child write his or her own story and read it together.
- Keep a record of how many words your child can read in 1 minute. A fluent reader (between 7 and 11 years old) will read at approximately 90 words per minute. Do a ‘before and after’: record your child reading a passage the first time; then record them again after their reading fluency has improved. Celebrate their success!
If you have any concerns about your child’s reading, please speak to their teacher. |
In the UK, electricity is increasingly generated using renewable energy sources, such as wind and solar, and the cost of generating it in this way has fallen sharply over recent decades. Despite this, the price of natural gas continues to largely determine the price that consumers pay for electricity. This explainer sets out why.
The UK uses a mix of sources to generate its electricity: fossil fuels (mainly gas and coal), nuclear energy and renewable energy. The contribution of different generation methods to overall electricity supply has changed dramatically in recent decades.
In 1990, coal generated 80% of electricity. Newly privatised electricity companies then shifted towards generating electricity using natural gas, which had become cheaper (as the production of gas in the North Sea increased) and more efficient (thanks to technological advances and, more recently, carbon pricing).
Since 2000, fossil fuels’ contribution to overall electricity supply has decreased, while nuclear energy has provided 15-25%. The share of renewable sources has increased sharply: having made only a marginal contribution to supply in 2000, in 2020 its contribution was higher than that from fossil fuels for the first time (though this reversed in 2021).
For electricity to arrive in homes and businesses across the UK, it must be generated, transported and then sold to the customer. Companies can be involved in any or all three of these stages.
- Generation: There are many different companies operating in the electricity generation sector, of different sizes and using different generation methods.
- Networks: The National Grid runs the transportation (transmission and distribution) of electricity. It is responsible for making sure that the supply of electricity on the grid constantly meets demand.
- Retail supply: Electricity suppliers are responsible for selling electricity to consumers (households and businesses) and operate in a competitive market. There are many suppliers of different sizes and consumers can choose which one provides them with electricity.
There are two markets for electricity: the retail market (where households and businesses buy electricity from suppliers) and the wholesale market (where suppliers – and energy traders – buy electricity from generators).
In the retail market, consumers enter into a contract with an electricity supplier.
Households typically either agree a fixed price or pay the ‘default tariff’. The industry regulator, Ofgem, sets a ‘price cap’, which determines the latter. Given the recent surge in wholesale prices and huge uncertainty surrounding future prices, most fixed-price deals are now above the price set by the price cap, so most customers entering into a new contract will pay the default tariff. Ofgem now adjusts the price cap four times a year and this is set using market-based forecasts for wholesale prices during the three months that it covers.*
Most businesses also buy energy from the retail market and will agree a contract with a supplier at a fixed price for a fixed period. But the price cap does not apply to businesses, so when such a contract comes to an end, the new price they face will depend on the current wholesale price. Businesses’ energy costs are therefore much more volatile than those for households.
Electricity suppliers buy the electricity they need to supply homes and businesses from generators on the wholesale market, which is open and competitive.
Wholesale electricity prices are not regulated and, instead, trading on spot (or day-ahead) markets sets them. In these markets, electricity generators bid to contribute to the power grid. The power exchange (Nord Pool in the UK) accepts these bids in price order, from lowest to highest, until demand is met, in what is known as the ‘merit order’: sources of electricity with the lowest marginal cost of generation (typically renewables, as they do not use any fuel) are the first bids to be accepted, and sources such as gas- and coal-fired power stations are the last (as they use fuel and the generator must also pay carbon tax on that fuel use).
In each half-hour trading period, the marginal cost of the last generating unit used to meet demand sets the price that the buyers (energy suppliers or traders) pay to the sellers (energy generators or traders) – known as a ‘pay as you clear’ model.
The marginal producer of electricity in the UK is most often gas because it is one of the most expensive sources, so is chosen last in the ‘merit order’ on the spot market. But it serves a vital role because gas-fired power stations can be easily switched on and off at short notice to make sure that supply balances to meet demand. Renewable energy sources, on the other hand, are unpredictable due to changes in weather, while nuclear energy provides a fairly constant source of power that is difficult to turn on and off.
This means that, although generation methods that have low marginal cost (including renewables and nuclear) produce the majority of UK electricity, the price that is paid for it in both wholesale and retail markets is set much higher, at the marginal cost of generating electricity with gas.
*The price cap includes costs other than wholesale prices, such as green levies and ‘network costs’, but these are much less volatile than wholesale prices.
It may seem odd that electricity produced with low-cost renewables should cost suppliers (and thus consumers) the same high price as electricity generated by gas-fired power stations. But this is a common feature of competitive auction markets of any kind.
The wholesale electricity market could instead be run using a ‘pay as bid’ auction model. In this type of auction, electricity generators would put in bids and be paid the price they bid, rather than the bid of the highest-priced supplier. If low-cost generators submitted bids at their marginal cost, this would lower the average cost in the wholesale market, feeding through to lower prices in the retail market.
But there would be no incentive for low-cost generators to bid at their true marginal cost. Instead, they would bid at the price at which they expected the market to clear. If renewable electricity generators were aware that demand was high enough for gas-fired power stations to be required, then they would know they would be able to sell their energy at (or just below) the marginal cost of gas-fired power stations. To prevent this sort of strategic bidding, additional controls on the market would be necessary.
Without radically altering the wholesale electricity market, it is difficult to break the link between marginal electricity generation costs (typically from gas) and the prices that consumers pay. But as part of its recently announced review of electricity market arrangements (REMA), the government is considering making the sort of fundamental changes that could break the link. Some options being considered include:
- moving to the ‘pay as bid’ auction model – but without additional controls imposed by government this may not lead to particularly large changes in electricity prices
- splitting the electricity markets into separate markets for variable power (for example wind and solar) and constant power (such as nuclear) – a more radical option.
- the creation of a ‘green power pool’, a government-backed entity that would offer long-term contracts to all low-carbon generators and sell directly to consumers, using exclusive access to cheap green power to deliver lower prices
The “Energy Price Guarantee” recently announced by the prime minister does not change of the rules of the market in order to lower prices, as the solutions above do. Rather, the policy lowers prices in the retail market by paying suppliers for the difference between the guaranteed price (equivalent to a typical household paying £2,500 per year) and the wholesale price, rather than changing the way in which wholesale prices are determined.
However, alongside the energy price guarantee, Truss announced that the government was exploring agreeing contracts with renewables generators (similar to existing ‘contracts for difference’) to provide electricity to the grid at below the current market price. The main benefit for generators would be price stability for the next 5-10 years. This would go some way to decoupling gas and electricity price, but is being considered as a short-/medium-term measure outside of the more fundamental reforms that may be introduced as a result of the REMA process.
1. Department for Business, Energy and Industrial Strategy, ‘Review of electricity market arrangements’, GOV.UK, 2022, retrieved 8 September 2022, www.gov.uk/government/consultations/review-of-electricity-market-arrangements
2. Keay, M. and Robinson, D., Market design for a decarbonised electricity market: the “two market” approach, in Rossetto, N. (ed.), Design the Electricity Market(s) of the Future, proceedings from the Eurelectric-Florence School of Regulation Conference, 7 June 2017. https://www.oxfordenergy.org/publications/market-design-for-a-decarbonised-electricity-market-the-two-market-approach/
3. Aldersgate Group, Policy Briefing: Delivering competitive industrial electricity prices in an era of transition, Aldersgate Group, 2021, www.aldersgategroup.org.uk/content/uploads/2022/03/DELIVERING-COMPETITIVE-INDUSTRIAL-ELECTRICITY-PRICES-IN-AN-ERA-OF-TRANSITION-policy-briefing.pdf
4. Department for Business, Energy and Industrial Strategy, ‘Energy bills support factsheet: 8 September 2022’, GOV.UK, 2022, retrieved 13 September 2022 https://www.gov.uk/government/publications/energy-bills-support/energy-bills-support-factsheet-8-september-2022 |
Picture a world where one man’s wealth surpassed that of any other in history. A man so rich that he could pave roads with gold and build mosques as magnificent as palaces. You may have Mansa Musa history in mind.
Musa was the tenth Mansa, or king, of the West African empire of Mali from 1312 to 1337 AD. It was during his reign that Mali reached its peak power and prosperity. He was a brilliant businessman and a devout Muslim who used his wealth to build mosques, libraries, and schools throughout Mali. He also patronized the arts and sciences, and his court was a center of learning and culture.
His wealth mindset charmed many people then and now and his legacy passes on to generations today.
Table of Contents
Is Mansa Musa The Richest Person Ever?
A huge part of Mansa Musa history is based on his colossal wealth estimated to be $600 billion. Besides building mosques and schools across the Empire of Mali from his pocket, his caravan painted a picture of a wealthy man. In 1324, Mansa Musa embarked on a pilgrimage to Mecca, the holiest city in Islam.
His pilgrimage was a lavish affair, with a caravan of over 60,000 people, including 12,000 slaves carrying gold dust. Mansa Musa distributed gold so freely along the way that its value plummetted. His wealth came from Mali’s control of the gold trade in West Africa. His empire also produced salt and other valuable commodities and used his wealth to develop Mali.
Mansa Musa history captures a man who could travel with an entourage so large that it could deplete the food and water supplies of entire cities along the way. He was so generous to the core that gold was his way to thank people for their benevolence. His pilgrimage brought him international fame and recognition and his return to Mali a hero, and his reign continued to be a golden age for the empire. He died in 1337 AD, leaving behind a legacy of wealth, power, and cultural achievement.
How Did Mansa Musa Lose His Money?
Despite his huge fortune, Mansa Musa history captures details of how he lost some of his money. A case in point is during his pilgrimage to Mecca with a caravan of over 72,000 where his gold donations to people dipped their prices for over a deacade. Secondly, inefficiencies in his government led to wastage of resources which became an eye sore. Lastly, his numerous military campaigns gobbled up a lot of money.
How Rich Was Mansa Musa Today?
Mansa Musa’s wealth back in the 14th century is estimated to average between $400 – $600 billion in 2023. However, the empire he built with a lot of sacrifice all went down after his demise. Today, Mali is a pale shadow of the successful empire it was in the 14th century under Musa’s reign.
Is Mansa Musa Richer Than Elon Musk?
In critical analysis, Mansa Musa is richer than Elon Musk who is among the world’s richest people. According to Bloomberg, Musk’s net worth in 2023 is $269.8 billion placing him as richest person in the world. In contrast to Mansa Musa history in wealth – estimated to be $400 billion – he is theoretically richer than the SpaceX CEO. Most of the Emperor’s wealth came from trading in salt and gold which were treasured good back in the day.
Mansa Musa history is a charming anecdote of the wealthiest African ruler to ever live. This is the world of Mansa Musa, the wealthiest man who ever lived. Mansa Musa’s life is a story of unimaginable wealth, power, and ambition. He was a man who lived larger than life, and his legacy continues to fascinate people centuries after his death.
- Who is the richest man ever on earth?
Mansa Musa, an Emperor of Mali Kingdom in the 14th century remains the richest man to have ever lived. His fortune in today’s estimates is way above Elon Musk’s who is currently the richest man in the world.
- Why did Mansa Musa fail?
His legacy went to the drain after his death in 1337 and the Mali empire tumbled down due to poor governance. More trading centres also emerged and it eventually led to civil war.
- How long did Mansa Musa live?
He lived for 57 years. He was born in 1280 and he died in 1337.
- Who was the richest man in Africa gold?
Mansa Musa was the richest man in Africa gold. His caravan to Mecca dipped gold prices in Egypt for over 12 years because he gave it out for free to anyone he met. |
Celebrating Birds: The Phenomenon of Migration
Volume 25 Issue 2, Spring 2020
by Joe Coleman
Every day, any time of day, somewhere in the Western Hemisphere, birds are migrating. The peak of migration in our area occurs in May and then again from late September through early October. As Scott Weidensaul wrote in his book Living on the Wind , “If it is spring or fall, the great pivot points of the year, … continents are swarming with billions of traveling birds — a flood so great that even the most ignorant and unobservant notice, if nothing else, the skeins of geese and the flocks of robins.”
Some birds migrate during the day. Many others, the majority in terms of sheer numbers, migrate at night, generally beginning about a half hour after sunset. Those observers fortunate enough to watch this on radar see what appears to be a great cloud rising from the landscape.
About 75% of North America’s 650 nesting bird species migrate. While some of these birds will only move a few states, others will shift all the way to Argentina. In some areas a species doesn’t migrate at all, while in another only the females migrate. Dark-eyed Juncos, often called snowbirds because they go south for the winter, are an example of this. Some young male juncos never leave Canada during their migration, while adult females will go all the way to the southern U.S. Young males migrate the shorter distance, perhaps so they can be the first to return home to establish a territory.
Although some species never leave the U.S., many go to Mexico and Central America and about 50 species go all the way to South America. Only about 10 songbird species, including Eastern Kingbirds, a common summer resident in Loudoun County, and Bobolinks, a rapidly disappearing summer resident in the county, travel beyond the Amazon basin. Bobolinks, a delightful and attractive blackbird with an incredible song, have the longest migration of any blackbird species, traveling from North America to northern Argentina. Like many migrants, both sexes return to the same nesting grounds year after year. While some Bobolinks follow the coast south, others travel out over the Atlantic on their journey to South America.
Another fascinating aspect of migration is the role of fat. Fat deposits in non-migrating birds are about 5%, while long-distance migrants build their fat reserves to 50% or more of their total body weight before they begin migration. The Ruby-throated Hummingbird, the only nesting hummingbird in the eastern U.S., normally weighing about 3 grams (0.11 ounces), increases its weight by 2 grams (0.07 ounces), or by two-thirds, for its journey. As a result it can fly across the Gulf of Mexico nonstop if the winds are right.
Unfortunately, the phenomenon of migration is showing signs of trouble. For over a century the Migratory Bird Treaty Act of 1918 was the cornerstone of bird protection. Last year the current federal administration severely weakened this protection. Even before then, humankind’s footprint on the land was having a strong impact on birds. With increased habitat loss and all the other ways humans have impacted the natural environment, birds are struggling. It is up to us to recognize what is happening and to do something about it now.
Scientists have learned a tremendous amount about migration recently, but because a great deal of research is continuing, what we know about migration is constantly evolving. For more information on this very complex topic you can review these resources:
•All about Birds by the Cornell Lab of Ornithology, an online resource accessed at www.allaboutbirds.org that is constantly being updated.
•Living on the Wind: Across the Hemisphere with Migratory Birds by Scott Weidensaul (North Point Press, 1999).
•The Sibley Guide to Bird Life and Behavior by National Audubon Society (Alfred A. Knopf, 2001). |
Rajasthan Board RBSE Class 10 Science Notes Chapter 3 Genetics
- Heredity: Inheritance of characters from one generation to next generation is called heredity.
- Variation: The difference in traits between two individuals is called variation.
- Genetics: The branch of biology which deals with heredity and variations is called genetics.
- Mendelism: Laws of inheritance were proposed on the basis of Mendel’s findings. These laws are also termed as Mendelism.
Reasons for Mendel’s Success :
Some of the reasons for his success are as follows:
- Mendel studied inheritance of only one trait at a time rather than taking too many traits into account.
- Mendel did careful statistical analysis of all the data collected during the experiment. This gave a solid mathematical foundation to his findings.
- Mendel was also careful in selecting the plant for his experiments.
Selection of Pea Plant:
Scientists could make some assumptions on this topic which can be as follows:
- Pea is an annual plant and hence it is possible to study many generations of pea in a short time period.
- Pea plant produces bisexual flowers. Hence, it is possible to get a pure line of homozygous plant through self pollination.
- Artificial pollination can be easily done with the help of encapsulation of flowers.
- A pea plant shows many pairs of contrasting characters which are inheritable.
|Seven Pairs of Inheritable Traits as Selected by Mendel|
|Traits of plant||Dominant||Recessive|
|Height of plant||Tall||Dwarf|
|Position of flower||Axial||Terminal|
|Shape of mature pod||Inflated||Constricted|
|Colour of immature pod||Green||Yellow|
|Shape of seeds||Round||Wrinkled|
|Colour of seeds||Yellow||Green|
- Gene: A factor which controls a trait is called gene. Mendel used the term ‘factors’ which was later termed as ‘gene’ by Johannsen.
- Allelomorph or Allele: For any given trait, there are two independent inheritable forms. These are called allelomorph or allele. For example, the gene which controls the height of a plant has two alleles, i.e. T(tallness) and t(dwarfness).
- Homozygous: When both the genes in a pair of alleles are similar, the gene is called homozygous, e.g. TT or tt.
- Heterozygous: When the genes in a pair of alleles are dissimilar, the gene is called heterozygous, e.g. Tt.
- Phenotype: The apparent characters which can be easily recognized make the phenotype. For example, height, hair colour, eye colour, colour of flowers, etc.
- Genotype: The genetic constitution of an individual is called genotype. For example, a tall plant can be hozomozygous with genotype TT or heterozygous with genotype Tt.
- Monohybrid Cross: When inheritance of only one character is studied during hybridization, the hybridization is called monohybrid cross.
- Dihybrid Cross: When inheritance of two characters is studied during hybridization, the hybridization is called dihybrid cross.
- Trihybrid Cross: When inheritance of three characters is studied during hybridization, the hybridization is called trihybrid cross.
- Polyhybrid Cross: When inheritance of many characters is studied during hybridization, the hybridization is called polyhybrid cross.
A cross in which plant ‘A’ (TT) is used as male parent and plant ‘B’ (tt) is used as female parent and another cross in which plant ‘A’ (TT) is used as female parent and plant ‘B’ (tt) is used as male parent, then this case is called reciprocal cross.
- Parental Generation: The plants which are hybridized to obtain offspring is called parental generation.
- F1 or First Filial Generation: The first generation obtained after crossing the parents is called F1 generation or first filial generation.
- F2 Generation or Second Filial Generation: The generation obtained after cross of Ft generation is called F2 generation or second filial generation.
- Monohybrid Ratio: The ratio of offsprings with different traits obtained after monohybrid cross is called monohybrid ratio.
- Dihybrid Ratio: The ratio of offpsrinng with different traits obtained after dihybrid cross is called dihybrid ratio.
- Mendel’s Laws of Inheritance: These are laws proposed by Mendel which are also called laws of genetics.
Law of Dominance :
This law is based on the results of monohybrid cross. This law says that when homozygous plants are crossed for a pair of particular trait then only one of the traits expresses in Fa generation. This trait is called dominant trait. The trait which does not express in F1 generation is called recessive trait.
Law of Segregation or Law of Purity of Gametes:
This law is also based on monohybrid cross. This law says that during gamete formation of hybrid plants of Fa generation, both the alleles separate from each other and go to different gametes. As the genes from a pair segregate during gamete formation hence this law is called law of segregation. Due to presence of two alleles for each trait, this law is called the law of purity of gametes.
When F1 generation is crossed with either of the parents (TT or tt), it is called back cross. There are two types of back cross which are as follows:
- Out Cross: When plants of Fx generation (Tt) are crossed with the parent with dominant character (TT), it is called out cross. All offsprings obtained after this cross are tall plants. Half (50%) of them are homozygous tall (TT) and half (50%) of them are heterozygous tall (Tt).
- Test Cross: When plants of F] generation (Tt) are crossed with parent with recessive character (tt), it is called test cross. Half of the offspring are heterozygous tall (Tt) and half (50% are homozygous short (tt). Thus, both phenotype and genotype ratio among offsprings is 1:1.
Law of Independent Assortment:
This law is based on results of dihybrid cross. This law says that when plants with two or more characters are crossed then inheritance of one character has no effect on inheritance of another character. This means that alleles of each character are not only separated during gamete formation but also behave independently of each other. Because of freedom of combining with any other trait, this law is called the law of independent assortment. This means that tallness can go with any colour of flower, i.e. white or violet. Similarly, violet followers can go with any shape of pod.
Importance of Mendel’s Law of Inheritance
- The presence of dominance of a particular trait ensures that harmful traits are suppressed through generations. Thus, presence of dominant trait is very important for survival.
- Law of independent assortment confirms the gene concept.
- Appearance of new traits can be easily explained with these laws.
a Traits can be carefully selected for producing new varieties of plants with desirable characters.
- Knowledge of these laws can be utilized to produce plants and cattle with desirable trait. For example, large varieties of rice with higher yield have been produced by careful hybridization.
- The concept of Eugenics is based on Mendelism. Eugenics deals with improvement in the human race. |
Common Dielectric Waveguide Applications
The presence of dielectric materials in a waveguide structure forms a dielectric waveguide that relies on the reflection from the dielectric interface for wave propagation.
The types of dielectric waveguides are dielectric slab waveguides and optical fibers.
Dielectric waveguide applications include integrated optical systems, optical communications (optical fibers), and shorter millimeter-wavelength integrated circuits.
Optical communication is one place dielectric waveguides can be applied
Waveguides are structures used to direct and propagate electromagnetic waves such as radio waves, microwaves, and infrared waves. Waveguides can be classified into metal waveguides and dielectric waveguides. Metal waveguides are made of metal, whereas in dielectric waveguides, the dielectric interface allows the reflection of electromagnetic waves.
Dielectric waveguide applications include monolithic integrated circuits, optical communications, integrated optical systems, and shorter millimeter-wavelength systems. In this article, we will explore the classifications of waveguides as well as various dielectric waveguide applications.
What Are Waveguides?
Waveguides are employed in various applications for propagating electromagnetic energy within a certain frequency range in the desired direction in space from one point to another. The structure of a waveguide influences the operating bandwidth of the waveguide. The lower operating frequency of the waveguide is dependent on the electrical property of the waveguide structure.
When an electromagnetic wave is transmitted from one end of the waveguide, it gets reflected due to the waveguide's internal structure. The interaction between the reflected waves in the waveguide produces discrete characteristic patterns called modes. The number of modes is dependent on the geometry of the waveguide, the medium in the waveguide, and the operating frequency.
In waveguides, modes can be either transverse electric (TE) mode or transverse magnetic mode (TM). Waveguides fail to support transverse electromagnetic (TEM) propagation due to their structure being made of a single conductor.
Classification of Waveguides
Based on the material used for building waveguides, they can be classified into:
Metal waveguides: Metal waveguides consist of enclosed metal pipes. The fundamental principle of wave propagation in metal waveguides is the total internal reflection from the conducting sidewalls. Rectangular waveguides and circular waveguides are examples of metal waveguides.
Dielectric waveguides: The presence of dielectric materials in the waveguide structure forms dielectric waveguides. They rely on the reflection from the dielectric interface for wave propagation.
Let’s explore dielectric waveguides and their applications.
A simple dielectric waveguide, called a typical dielectric slab waveguide, consists of a planar film of material with refractive index nr, which lies between a substrate and a cover. Light, which is guided by total internal reflection, is reflected internally between the film-substrate and film-cover interfaces and propagates forward to a target destination.
The Refractive Index
Various materials make up dielectric waveguides, and the refractive indices of the materials used in dielectric waveguides are critical in guiding light from the source to the destination. The refractive index is an important parameter that determines the characteristics of a dielectric waveguide structure. The refractive index of substrate ns and cover nc should be lower than the refractive index nr. The cover material is usually air, which has a refractive index equal to unity. Typically, refractive index value differences range from 10-3 to 10-1 and the film thickness is 1µm.
Types of Dielectric Waveguides
The types of dielectric waveguides are:
Dielectric slab waveguide - If ns = nc, the waveguide structure turns into a symmetric dielectric slab waveguide. When ns ≠ nc, then the structure is an asymmetric dielectric slab waveguide.
Optical fiber - Optical fibers are the most important dielectric waveguide. They are made of glass or plastic and are used to transmit information in the form of light pulses in optical communication systems.
Dielectric Waveguide Applications
Dielectric waveguides are very important in integrated optical systems, optical communications (optical fibers), and shorter millimeter-wavelength applications.
Dielectric waveguides are often used in guided-wave devices and integrated optic circuits for confining and guiding light in the preferred direction. Usually, in integrated optics, planar dielectric structures—such as planar strips or films—are of interest. In active integrated optic devices such as lasers and modulators, the optical confinement provided by dielectric strip waveguides is utilized for saving the drive voltage and drive power.
The widespread use of optical fibers emerged as a result of developments in the field of optical frequency sources, especially lasers. Optical fibers generally consist of a circular core surrounded by a cladding of dielectric material. The circular core often varies in dielectric constant radially.
Optical communication, internet communication, cable TV, and television broadcasting systems benefit from the use of optical fibers. The data transmitted over optical fibers travel long distances with more power and less distortion. Signal transmission through optical fibers offers advantages like high-speed data transmission, data security, and data reliability in communication systems.
Shorter Millimeter-Wavelength Applications
Dielectric waveguides support TE and TM modes of wave propagation and are suitable for miniaturization. The small compact sizing and wave propagation modes of dielectric waveguides make them convenient for integration with active devices utilizing millimeter-wavelength signals. In millimeter-wave integrated circuits, dielectric waveguides form the low-frequency replicas of optical waveguides.
Terahertz applications in spectroscopy, sensors, radars, and imaging use parallel-plate dielectric waveguides. Parallel-plate dielectric waveguides consist of parallel plates that are perfectly conducting and three rectangular dielectric materials are placed between the parallel plates. The strong energy concentration and weak radiation field exhibited by parallel-plate dielectric waveguides provide better results in terahertz applications.
Cadence software offers tools for fabricating dielectric waveguides for integrated optical systems, optical communications systems, and shorter millimeter-wavelength applications. Subscribe to our newsletter for the latest updates. If you’re looking to learn more about how Cadence has the solution for you, talk to our team of experts. |
Blood is a vital element in keeping a human being alive, as it is responsible for a number of tasks that keep our body in balance. Therefore, knowing your blood type is essential before undergoing surgery or receiving transfusions. However, among the different types that exist, there are those that are considered extremely rare. Below, learn more about what rare blood types are and how to know if you have one.
What are blood and blood groups?
Blood is present in the internal region of our body and is considered a living tissue, capable of transporting oxygen directly to the lungs, helping to defend the body from infectious agents, promoting coagulation, transporting already assimilated food to the cells and even collecting part of it. waste and carry it to the kidneys to be eliminated in the urine.
Blood groups are made up of a set of groups that bring together and differentiate the different types of human blood. This categorization is essential because receiving an inappropriate blood type can lead to death, so it is necessary to analyze all the particularities of each blood and group them.
In Brazil, blood typing takes into account two main factors, the ABO group (A, B, AB and O) and the Rh factor (positive and negative). However, it is possible to find numerous other classifications, which differentiate one tissue from another, for example, based on the type of antigen present. These antigens are proteins on the surface of red blood cells (blood cells), which help make the characteristics of your blood even more precise when you donate or receive a transfusion.
What are rare bloods?
According to the International Society of Blood Transfusion (ISBT), a blood type can be considered rare when it appears in one person in every thousand inhabitants of a civilization. So, the rarity of blood depends, for example, on where it is found: it is possible that a phenotype considered rare is abundant among the indigenous populations of South America, but uncommon in the rest of the world, so it would be considered rare blood. . Considering this observation, it is possible that a blood is rare in some communities and very common in others.
Of the rare blood types, many consider “golden blood” to be the most difficult to find. Also called “Rh null blood”, it is very precious for saving human lives, as it can be donated to anyone who falls into the traditional blood group with Rh positive and negative. However, it can be considered a disadvantage for the host, as they can only receive a transfusion of other Rh null blood –– so if finding one person with golden blood is already difficult, imagine finding two.
In Brazil, in addition to golden blood, there are other blood groups considered rare because they are not very present in the Brazilian population, such as AB-, B- and AB+.
How do you know if you have a rare blood type?
To identify your blood and find out whether it has rare characteristics or not, you need to carry out a test called “blood typing”, which will identify which ABO group you belong to and identify the antigens present (or absent) on the red box of blood cells.
The post Rare Blood Types: What They Are and How to Know If You Have One appeared first on Olhar Digital.
Source: Olhar Digital
I’m David Jackson, a professional news writer and author at Run Down Bulletin. I specialize in writing health news stories that offer readers the latest information on medical discoveries, treatments and advancements. |
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