text:
Fungus gnats are as common as dirt wherever plants are grown, but like dust balls under the bed we only notice them when they get out of hand. So far as we know, this never happens in the garden, where natural predators and the vagaries of weather and the seasons keep their populations in check. But indoors in hobby greenhouses or on potted plants, fungus gnat numbers can sometimes soar, and a spray from the watering wand or routine sanitation among the pots on the windowsill can stir up a fruit-fly-like explosion of winged insects.What Triggers Outbreaks?
Although the linkage isn't fully explained yet, researchers agree that high fungus gnat populations are linked to high humidity and soil moisture levels. It may have something to do with the insect's vulnerable egg stage. (Like all flies, fungus gnats have four developmental stages: egg, larva, pupa and adult.) Millie Casey, research assistant at the Ohio State Agricultural Research and Development Center insect lab in Wooster (where she and her colleagues have been studying fungus gnats for several years), says fungus gnat eggs "are very much subject to desiccation. On the other hand, each adult can lay up to 200 eggs, and when the moist conditions that favor egg development are present in a species that goes from egg to adult in only 10 to 14 days, populations are likely to boom."
Another theory is that high humidity and soil moisture encourage the growth of the larval stage. Under normal conditions, larvae feed on soil fungi, just about any soil fungi. Fungus gnats are very closely associated with fungi and highly attracted to them, says Mary Harris, a doctoral candidate working on fungus gnats at the University of Georgia in Athens. (Some people call these insects "fungus-feeding gnats" to call attention to this characteristic.) When moist conditions favoring fungal growth are present, larval food sources can also increase, and with them larval populations.
Fortunately for indoor gardeners whose plants also depend on moist conditions and adequate soil organic matter content, fungus gnats -- and then only the adults -- are usually just a nuisance. A cloud of tiny insects that appears when pots are moved or plants are disturbed may look like a pest problem, but it usually only indicates a living soil.Some Threat of Disease
When fungus gnat populations explode, however, and larvae exhaust the limited fungal food resources in a greenhouse bench or plant pot, they can turn to feed on plant roots and sometimes stems. Again, under most circumstances this feeding is only a nuisance with no visible plant symptoms. Casey says "If you have a strong, healthy plant with a healthy root system, fungus gnats pose absolutely no problem at all." Young plants, however, are sometimes set back by damage to their already-limited root systems.
Many indoor gardeners can live with even this relatively minor threat to the health of their plants. But now, after reassuring growers for years that the gnats were largely a cosmetic problem, researchers have found the threat doesn't end there. In a recent breakthrough, Harris has shown that both fungus gnat larvae and adults occasionally transmit a variety of diseases. She's proved they spread black root rot and Pythium wilt and suspects they transmit many other fungal pathogens as well. It's akin to discovering dust mites carry the common cold.Controls
Water management is crucial to controlling fungus gnat buildups. Harris says to absolutely avoid overwatering, particularly of young plants. This is especially good advice for the winter months when air circulation, light levels and growth rates -- and therefore evapotranspiration -- are lower.
Potting mixes also seem to make a difference. Harris says that fresh potting mixes seem more attractive to fungus gnats than older mixes (another reason to be vigilant over your young plants, which are usually potted up in fresh materials). Dr. Richard Lindquist, professor of entomology at Ohio State in Wooster, and Casey found that potting mixes containing higher percentages of compost, especially compost less than six months old, were more likely to breed larger numbers of fungus gnats.
But you don't have to reserve your compost for the garden. Bruce Steward, integrated pest management coordinator at Longwood Gardens in Kennett Square, Pennsylvania, says they grow their bulbs "in a soil type the gnats like." Simply take advantage of the fungus gnat larvae's preference for the upper soil layers and add a half-inch layer of sand to the tops of their bulb pots. "It really works," says Steward. "The eggs probably dried out, or perhaps the adults couldn't emerge."
For routine fungus gnat control, Steward drenches pots and flats with Gnatrol (Bacillus thuringiensis H-14), applying it weekly for two or three weeks. (The B. t. israelensis strain, usually marketed for mosquito and black fly control, is also effective against fungus gnats.) Results aren't immediate. Bt doesn't kill egg-laying adults, so "you've just got to keep at it," Steward says. Harris agrees that it takes time to get control with Bt, and suggests using it to prevent infestations rather than cure them. "A rule of thumb with biologicals," she says, "is you can't wait until you get an infestation. All these organisms seem to work best when pest populations are lower." She recommends watering new transplants with a B.t. israelensis or Gnatrol solution.
Many commercial greenhouse growers use synthetic growth regulators to control fungus gnats. Azadirachtin, an extract from seeds of the neem tree, seems to work in the same way, and is available to home gardeners. Like Bt, it's usually applied as a soil drench. It appears to have little impact on beneficial organisms.
Beneficials are a focus of Stanton Gill's five-year integrated pest management research program at the University of Maryland's Central Maryland Research and Education Center in Ellicott City. His greenhouse trials have shown that a predatory mite, Hypoaspis miles, and a nematode, Steinernema feltiae, offer good control of fungus gnat larvae. The combination of mite and nematode seems to work very well, says Mary Harris. Beneficials can't always be counted on for the long run, because once they've consumed their pest hosts, they'll die or depart, leaving the plant unprotected. But when fungus gnat food resources are exhausted, Hypoaspis mites will turn to feed on the nematodes -- and be present when fungus gnat populations rise again. Harris stresses that only the nematode Steinernema feltiae really works against fungus gnats. Indoor gardeners who use the more common species S. carpocapsae will be disappointed with the results, according to Harris.
You can, as Harris recommends, use Bt and other beneficials as preventive measures before pest levels build up. Or, like Longwood's Bruce Steward and many commercial growers, you can wait until monitoring indicates it's time to act.
Steward uses yellow sticky cards to monitor fungus gnats. Stanton Gill monitors the larvae with a one-inch-diameter potato ball laid on the surface of the growing bench or pot, a technique suggested by Mary Harris. It works as long as the greenhouse mice don't pack the potato pieces away.
Photography by National Gardening Association
|Thread Title
|Last Reply
|potted plants by jgb1957
|Aug 25, 2017 4:46 PM


text:
On our vacation this year to Rockport, Massachusetts, we spent an hour one night watching the Perseid meteor shower. This is my favorite meteor shower because I can lay outside and not get cold too fast. The night sky is far darker on the end of Cape Ann than it is at home in Delaware, so it was a rewarding activity. There's really nothing like staring at the stars and pondering the vastness of space to make you realize your puny human problems aren't worth losing sleep over.
Ancient astronomers were the first to notice that most of the objects in the night sky moved in circular patterns. They also observed that a few did not move this way, and those they named wandering stars. The ancients' wandering stars are what we today know as planets. Almost since humans recognized that Earth was also a planet, we have wondered whether there could be life in other parts of the universe. Recent technological advancements in astronomy have increased confidence in the probability that there are other forms of life in the universe.
Detection and Identification
The United States National Air and Space Administration (NASA) developed the ongoing Kepler mission to detect other planets in the universe and identify those that are similar to Earth in size, chemical composition, and orbit. Kepler is a spacecraft and photometer that continuously points at the same group of stars. The Kepler mission has identified a number of Earth-like planets in the habitable zones of stars. Since its launch on March 6, 2009, Kepler has identified 12 Earth-like planets in the habitable zones of stars. This is remarkable because the Kepler field of view is just a tiny portion of our galaxy, and the galaxy is a tiny portion of the universe.
Identifying a planet as potentially habitable isn't enough to say if it is certainly so. The crucial element is water. The habitable zone for humans is identified as the orbital period around a star where liquid water might exist on the surface of the planets. The way that astrophysicists calculate a planet's temperature is described here. The habitable zone for a star system can also be calculated.
A potentially habitable planet must also have an atmosphere. An atmosphere shields the planet's surface from impacts and radiation, both of which can be hazardous to life. Some researchers have posited that some planets' atmospheres could evolve over time. If a big planet forms in an outer orbit, with a rocky core and a thick gaseous atmosphere (similar to Neptune in our solar system), tidal forces in that star system could cause the planet to change and move over time. The star's gravitational pull would stretch the planet into an ellipsoid and possible pull the planet closer to the star. The friction caused by these movements would cause heat, that could potentially drive surface volcanism or drive off lighter gasses in the atmosphere. If the planet has shifted into the star's habitable zone, the leftover rocky core could be a habitable planet.
Are We Alone?
Although the existence of a number of planets in the habitable zone of other star systems has been proven, no one has yet seen these planets or captured images of them. There are a number of reasons why the search for other habitable planets matters to all of us. One is of course that the question of "Are we alone?" has fascinated humans since the recognition of Earth as a planet. Another is that the natural evolution of a star means that the Sun will eventually make life on Earth unsustainable, and we definitely don't want to be in the neighborhood when that happens.
The recent discovery of Kepler 452b has been exciting for astrophysicists because its star is very similar to our Sun and the planet is of similar size, mass, and distance from its star as Earth. Its mass is likely about 5 times that of Earth because it is about 60% larger in diameter. The additional mass would provide many thousands of additional years of protection for the planet's atmosphere from the increased energy of its star.
The relatively new field of astrobiology offers new opportunities for students interested in an interdisciplinary STEM career. Astrobiology degree programs are currently offered at a number of U.S. universities, including the University of Washington and the University of Hawaii. A comprehensive list of international educational resources can be found here.
Produced by the National Science Teachers Association (NSTA), science writer Becky Stewart contributes monthly to the Science and STEM Classroom e-newsletter, a forum for ideas and resources that middle and high school teachers need to support science, technology, engineering, and math curricula. If you enjoy these blog posts, follow Becky Stewart on Twitter (@ramenbecky).
Follow NSTA

subset: commoncrawl


text:
Hello Teresa and Patti,
Thank you for contacting us about the rewards not appearing for rating Simon's Slots and for connecting to Facebook.
The rewards for performing both of these actions can be claimed in the Achievements area. The Achievements area can be accessed when you select the Achievements button located in the upper right corner of the screen in any Lobby.
Please give this a try and you will find that you can collect your rewards.
Thanks for choosing Simon's Slots!
Best regards,
Blue Crystal Labs Support


text:
This music major's job offer created a dilemma for him. What would you do if you were offered a job in your field before you finished your degree?
That's exactly the challenge that faced Anthony McCain, voice performance major, now in his sophomore year at Oberlin Conservatory Of Music. Remember him? He was the gutsy, talented freshman who wrote Building a Music Career… One Cookie at a Time, about how he funded the one crucial part of his education not covered by scholarships.
Seems McCain's YouTube videos may have caught the eye of a five-star cruise line. Shortly before school started, a recruiter offered him a contract that would cover travel to places like Alaska, Hawaii, and the Caribbean, with all expenses paid plus a salary. McCain's job? Perform nightly.
The too-good-to-be-true offer proved to be daunting for McCain. As a student on full scholarship who worked so hard just to physically get to his school 2,200 miles from his home in Washington state, the decision was a tough one. As he says, "I didn't want to make any decision that I might regret…I really gave it a whole lot of thought. I gathered my own thoughts and weighed the options, the pros, the cons."
McCain then sought the assistance of his voice teacher at Oberlin as well as others. Their opinions coincided with his. "Everyone I asked –– teachers, coaches, etc. –– agreed that I should stick with school for now. If I had accepted this contract, I might have a job, an income, and performance time, but I wouldn't be at my best. Each year I improve so much that it would be silly to stop now. I want to give my best and be my best. I'm perfecting my craft, which is more important to me right now."
Wisely, McCain declined the cruise line offer with the caveat that, once he graduates, he may be interested. He'll also talk with the recruiter about the possibility of a summer gig.
McCain's advice to any student facing a similar dilemma? "Sleep on it first! There shouldn't ever be a rush because that's when you might make decisions you later regret. After you sleep on it, then take some time to think about it, its possibilities and effects on your future versus where you are right now in your life. Once you have your own opinion, ask teachers, mentors and those who have your best interest at heart for advice."


text: Sapareva banya is situated on the Northern slope of Rila Mountain in Southwestern Bulgaria, just a two hours drive from the Capital of Sofia. The municipality contains the popular tourist destinations of the Seven Rila Lakes and the Skakavitza Reserve and Waterfall. As well as the administrative center of Sapareva Banya, 15 kilometers East of Doupnitza, the municipality includes the villages of Saparevo, Resilovo, Ovchartzi and the mountain resort of Panichishte. The municipality proudly shares one third of its territory with Rila National Park, which was established in 1992. While Sapareva Banya is known for its cool, clean mountain water, it is famous for its unique geothermal mineral water. Here one finds the hottest mineral water in all of Europe (103degrees C) and the only active Geyser in the Balkans. To reach Sapareva Banya and the Panichishte Resort, travel south from Sofia on the International Highway E - 79 for 45 minutes. Take the Doupnitza exit and follow the signs to Sapareva Banya (15 minutes). For public transportation services to Sapareva Banya there is one direct bus dailyat 2:00p.m. from the "Ovcha Kypel" bus station. Buses run hourly from the same station to Doupnitza where you can catch any of the "Saparevo" buses that run every half hour. All buses will drop you off in front of the Tourist Information Center in Sapreva Banya.


text:
Further to Week 5 & 7 blogs on the construction of trench RC barrier for SPJ – 12B project and the effects of Learning curve on production we would now like to review production results observed over the past 12 weeks and assess the actual learning curve parameters and make an assessment of the total predicted man hours to complete the entire 1330 Lm of barrier wall – based on actual productivity figures
Two types of learning curves will be assessed for the purpose of assessing the actual learning curve parameters
- Unit Learning and;
- Cumulative average
Selecting the correct learing curve will be critical in estimating the total man hours to complete the works. The total hours (or cost) determined using the Unit Linear method will be the sum of the unit costs however the Cumulative Average linear, the total hours (or costs) will be the unit values times the total number of units up to that point.
Productivities for planned as well as actual cumulative figures are outlined in table 1 below
Contractor has performance from 12th August to the 3rd November is further broken down as per table 2 below.
Note that the Unit Linear figures are based on the weekly average.
To determine which curve can be used to estimate the total man hours at completion we must first evaluate which is most reliable. To achieve this we will perform a regression analysis on both sets of data and determine the R^2 or coefficient of determination.
The option which provides a R^2 value closer to 1.0 will be regarded as representative or best fit of the data. An R^2 of 0.9 or better is considered a good fit however a result of less than 0.9 may mean the resultant equation doe not adequately represent the data that are being analysed.
Both the Unit linear and Cumulative average are plotted on the graph below including the corresponding R^2 values and equations for each set of data and best fit curves
The Blue line indicates the cumulative average whilst the red dashed line indicates the Unit Linear and whilst the R^2 for the cumulative average is closer to 1.0 than the unit linear, both options are below 0.9 indicating that the line of best fit or equation may not accurately represent the data.
6. Selection of the Preferred alternative
Whilst neither curve satisfies the requirement of an R^2 value <0.9, the cumulative average may provide the best chance of estimating total man hours at completion
Based on the figure 1 above, the learning rate of the cumulative average-time model is the anit-log of 10^-0.246*log(2) = 84.32%
The cumulative average is determined by =464*67^(log(0.8432)/log(2) = 165 mnhrs /unit with a total number of direct labour hours estimated as 11,047 (165*67 units)
6. Performance Monitoring
The range of the figures obtained from the field data would indicate that there is too much variance in the data to allow for the development of an equation that allows accurate forecasting.
The labour figures and productivities above are based on weekly averages and these will include non productive periods and man hours associated with delays from weather, concrete supply, etc.
It may be advisable to eliminate some of the data points which include excessive delay periods or exclude non productive man hours from the total figures.
Also consideration needs to be given to any changes in actual crew members and the impact that this may have on the crews overall productivity.
Further assessments will be over the next 2-3 weeks with a closer assessment of man hours spent during disruption or delay periods.
- Sullivan, G. W., Wicks, M. E., & Koelling, C. P.(2014). Engineering economy 16th Edition. Chapter 3 – Learning and Improvement., pp.110-112.
- Humphreys, G.C 2011 Project Management Using Earned Value Humphreys associates, Management Consultants. Second Edition, pp 435-440
- Dennis F. Togo, Curivlinear Analysis of Learning for Cost Estimation. Retrieved from http://http://www.swdsi.org


text:
Sign up for the newsletter now to get all the insider info for all things THD. Enter your email at the bottom of the page.
4 items
3 items
7 items
6 items
1 item
Sign up for the newsletter and you'll be the first to know of new products, upcoming events and things that just make you happy!
Thanks for Joining!
Sold Out


text:
System patching made easy
Here's an introduction to a handy patch management tool.
By now you've heard of the HFNetChk command line tool distributed by Microsoft and its GUI replacement, the Microsoft Baseline Security Analyzer (MBSA). Well, the company that designed the core structure of these tools, Shavlik Technologies, has an updated version of HFNetChk that you should seriously consider employing.
HFNetChkPro4 is a GUI-based patch management system that is simple to operate yet powerful enough to get the job done quickly and efficiently. This patch-implementation tool can support Windows NT, Windows 2000, Windows XP and Windows Server 2003 foundational operating systems, as well as the add-on products of Exchange, SQL Server, Outlook, Microsoft Office, Java Virtual Machine and more.
Patch management through HFNetChkPro4 is as detailed as you need it to be. It can be used to granularly control patch application down to which individual patches are applied to which systems all the way through to forcing all patches to all systems. The tool self-updates as it is launched so you always have the latest up-to-the-minute information from Microsoft as to what patches are necessary or recommended for your software. In comparison with any Microsoft patch distribution product, HFNetChkPro4 is easier to use, more versatile and more exhaustive. One of the features of HFNetChkPro4 that I'm most impressed with is its ability to use external third-party threat information, such as from BugTraq and CVE, in addition to that provided by Microsoft. This feature alone makes HFNetChkPro4 rank above any other product.
The main differences between HFNetChkPro4 and MBSA include:
- HFNetChkPro4 can be used remotely against all the systems on your network
- HFNetChkPro4 scans Exchange, SQL, Office, and Commerce Server systems
- HFNetChkPro4 performs patch ranking and supports third-party threat information
- HFNetChkPro4 includes an automatic self-update feature
HFNetChkPro4 is available for a free trial as well as full purchase for enterprise deployment. The free trial is a fully functional version of the software with no time restrictions on use, but it can only be used to manage patches for 10 clients and one server. I highly recommend visiting Shavlik and downloading this tool. After a few experiments with configuring patch implementation solutions, I'm sure you'll never want to go back to manual download and installation again.
There are several other options for a patch management solution, but I see no direct competitor to HFNetChkPro4. But just in case you want to make the comparison yourself, here is a list of the top patch management products available today:
- Altiris, Inc.'s Altiris Patch Management Solution
- BigFix, Inc.'s Big Fix Patch Manager
- Configuresoft, Inc.'s Security Update Manager
- Ecora's Ecora Patch Manager
- GFI Software Ltd.'s GFI LANguard Network Security Scanner (NSS)
- Gravity Storm Software, LLC's Service Pack Manager 2000
- LANDesk Software, Ltd.'s LANDesk Patch Manager
- Microsoft Corp.'s Software Update Services (SUS)
- Novadigm, Inc.'s Radia Patch Manager
- PatchLink Corp.'s PatchLink Update
- St. Bernard Software's UpdateExpert
About the author
James Michael Stewart is a partner and researcher for ITinfopros, a technology-focused writing and training organization.