DTC 354: Digital Storytelling
Class: T 5:45pm-8:30pm
Location: VMMC 111
Instructor: Will Luers
Office Hours: T 4:30pm – 5:30pm in The Digs or on Zoom after 12pm most days
NOTE: All matters associated with this course are subject to change. Any changes will be communicated to students.
DTC 354 / Digital Storytelling will immerse students in the theory and practice of creating and delivering stories in a digital and computational environment. We will look at narrative traditions that precede the digital to understand the foundations of storytelling as an evolved and evolving form of meaning-making and then proceed through different digital storytelling modalities – textual, diagrammatic/typographic, visual/auditory, cinematic and hypermedial – to arrive at an integrated approach to networked, multilinear and multimedia storytelling.
Lectures, blogging, in-depth readings and in-class discussion will offer students multiple modes for understanding the theories and expressive possibilities behind “digital storytelling.” Concepts explored will be the spring boards for students to develop their own practice-based research. Through short creative assignments and collaborative group projects, students will have the opportunity to work with text, digital imaging, sound, video, and other media to create new forms of the digital stories.
|Required Course Activities||University Learning Goals||University Learning Objectives||CMDC Goals & Objectives|
|1.Typographic, Visual & Cinematic||Critical and Creative Thinking (ULG1)Communication (ULG4)||Combine and synthesize existing ideas, images, or expertise in original ways.Express concepts propositions, and beliefs in coherent, concise, and technically correct form.||Goal 1 Demonstrate competency with computers for designing, distributing, retrieving, and preserving digital works in various mediums for humane and effective human-computer interactionsGoal 2 Synthesize media forms for multimedia contextsGoal 3 Employ the principles of visual form for sophisticated image manipulation|
|2. Hypermedia||Quantitative and Symbolic Reasoning (ULG2)||Understand and apply quantitative, symbolic and computational principles and methods in the solution of problems||Goal 7 Recognize various forms of language processing and their implications for media authoring|
|3.Korsakow||Critical and Creative Thinking (ULG1)Information Literacy (ULG2)Communication||Combine and synthesize existing ideas, images, or expertise in original ways.Determine the extent and type of information needed.Express concepts propositions, and beliefs in coherent, concise, and technically correct form.By applying the concepts of the general and specialized studies to personal, academic, service learning, professional, and/or community activities.||Goal 5 Know the basics of information architecture and knowledge management along with ways digital information can be structured for retrieval and archival purposes for different audiences|
|4. Final Project||Critical and Creative Thinking (ULG1)Information Literacy (ULG2)Communication (ULG4)Depth, Breadth, and Integration of Learning (ULG7)||Combine and synthesize existing ideas, images, or expertise in original ways.Determine the extent and type of information needed.Express concepts propositions, and beliefs in coherent, concise, and technically correct form.By applying the concepts of the general and specialized studies to personal, academic, service learning, professional, and/or community activities.||Goal 5 Know the basics of information architecture and knowledge management along with ways digital information can be structured for retrieval and archival purposes for different audiences|
The assignments and activities for this course reflect these objectives and serve to assist students with reaching program goals.
- Focus on the manual creation of web-based objects and other digital interfaces
- Readings, discussion of concepts, and application of theory
- Multiple assignments and projects
- Conceptual and creative work with ideas explored in this course
Required Course Texts and other resources
- The Poetics, by Aristotle (Bookie)
- Understanding Comics, Scott McCloud (Bookie)
- Movie Rentals: Occurrence and Owl Creek Bridge $1.99
- Selected online readings
- Access to smartphone and/or digital camera (option to check-out equipment)
Course Point-Earning Opportunities
- 5 story summaries 5%
- One-on-one Zoom meeting 5%
- Blogging: 20%
- Diagrammatic Narrative 10%
- Visual Narrative: 10%
- Video/Audio Story 10%
- Hypermedia Narrative: 10%
- Final Project: 30%
General Project Guidelines
- Multimedia projects should address narrative and design issues raised in this course
- Design and content must be your own work, unless otherwise stated.
- You may use AI image and text generation, as long as you state that in your sources
- All images not your own or significantly altered by you must be clearly labeled with ownership and copyright information
- Multimedia projects should be checked thoroughly for errors. There is no excuse for sloppy writing and such mistakes will count against you.
Assessment and Final Grades
Both attendance and participation will be monitored and deficiencies in either/both will result in lower final grades. Participation means being attentive in class, joining in discussions, engaging in informal critiques and completing all in-class and outside assignments.
You are allowed 2 class absences. Each class absence after that will result in a 5-point deduction from the final cumulative points. It is your responsibility to make sure I check your attendance if you arrive after the start of class. Frequent late arrivals, leaving early, or other forms of lack of attendance will also deduct points from the cumulative total. Absent students remain responsible for all course matters during their absence(s). Opportunities to make up missed work may not be available.
Final grades are determined from the cumulative points earned, plus or minus any deductions or additions for attendance or participation. No curving, averaging, or other manipulations are utilized. No other assessment or extra credit opportunities are planned. Incompletes are not available. Final grades are based on the following scale:
|D||no Ds in the DTC program|
Submission of Late Work
All work must be submitted as and when required. If you are sick or have an emergency, you must make contact with me (best to use Slack) and arrange a time to submit work.
Students are responsible for reading and understanding all university-wide policies and resources pertaining to all courses (for instance: accommodations, crisis resources, policies on discrimination or harassment), which can be found in the university syllabus: https://syllabus.wsu.edu/university-syllabus/
Student Wellness Center
If you are concerned about a student’s wellness center is available to help students with self-determination, self-advocacy and self-care. To contact or schedule with staff in Counseling Services or Health Services, please leave a detailed voicemail message at 360-546-9238 or email us at email@example.com or firstname.lastname@example.org. The Access Center has some changes in location and phone number. The Access Center office is now in VCLS 110, however, the Access Center Testing Classroom is still in VCLS 160A, adjacent to the Student Wellness Center Lobby.
Early Academic Referrals Program (EARS)
The first 3 weeks of the semester are a critical window for student persistence at the university. Students who miss class, fail to turn in work, or fail assignments are at academic risk. Research has shown that a “nudge” or “early intervention” can help students succeed in the course and persist in the university.
At WSU Vancouver we use two methods to request assistance for students.
- The Student Care Network (former AWARE Network) should be used if you see a student who is in severe distress and you are concerned may cause harm to self or others. https://www.studentcare.wsu.edu/home/
- The Academic Alert System should be used if you see a student who is struggling academically and would benefit from additional support. Please read the descriptions of the two systems and then select the one you think is more appropriate.
Instructors can support students in distress in the moment using skills and strategies from the Student Care Network’s Guide to Helping Students in Distress.
- Instructors may hear of financial hardships, food security needs, home security needs, or other fundamental need from students. Students in need of support to meet their fundamental needs can be referred for assistance through the Student Care Network.
Reasonable Accommodations Policy
Reasonable accommodations are available for students with documented disabilities or chronic medical or psychological conditions. If you have such a condition and need accommodations to fully participate in this class, please visit the campus’ Access Center/Services website to follow published procedures to request accommodations. Students may also contact their campus offices to schedule an appointment with a Access Advisor. All disability related accommodations are to be approved through the Access Center/Services on your campus. It is a university expectation that students connect with instructors (via email, Zoom, or in person) to discuss logistics within two weeks after they have officially requested their accommodations.
Vancouver Access Center
Academic Integrity Policy
Academic integrity is the cornerstone of higher education. As such, all members of the university community share responsibility for maintaining and promoting the principles of integrity in all activities, including academic integrity and honest scholarship. Academic integrity will be strongly enforced in this course. Students who violate WSU’s Academic Integrity Policy (identified in Washington Administrative Code (WAC) 504-26-010(4) will receive a failing grade in this class, will not have the option to withdraw from the course pending an appeal, and will be reported to the Center for Community Standards.
Cheating includes, but is not limited to, plagiarism and unauthorized collaboration as defined in the Standards of Conduct for Students, WAC 504-26-010(3). Read and understand all of the definitions of cheating. If you have any questions about what is and is not allowed, ask your course instructor.
If you wish to appeal a instructor’s decision relating to academic integrity, please use the “Appeal An Academic Integrity Decision” form available here. Make sure you submit your appeal within 21 calendar days of the instructor’s decision.
Accommodation for Religious Observances or Activities
Washington State University reasonably accommodates absences allowing for students to take holidays for reasons of faith or conscience or organized activities conducted under the auspices of a religious denomination, church, or religious organization. Reasonable accommodation requires the student to coordinate with the instructor on scheduling examinations or other activities necessary for course completion. Students requesting accommodation must provide written notification within the first two weeks of the beginning of the course and include specific dates for absences. Approved accommodations for absences will not adversely impact student grades. Absence from classes or examinations for religious reasons does not relieve students from responsibility for any part of the course work required during the period of absence. Students who feel they have been treated unfairly in terms of this accommodation may refer to Academic Regulation 104 – Academic Complaint Procedures.
Discrimination and Sexual Harassment Policy
Discrimination, including discriminatory harassment, sexual harassment, and sexual misconduct (including stalking, intimate partner violence, and sexual violence) is prohibited at WSU (See WSU Policy Prohibiting Discrimination and Harassment (Executive Policy 15) and WSU Standards of Conduct for Students). If you feel you have experienced or have witnessed discriminatory conduct, you can contact the WSU Compliance & Civil Rights (CCR) and/or the WSU Title IX Coordinator to discuss resources, including confidential resources, and reporting options. (Visit ccr.wsu.edu for more information). Most WSU employees, including faculty, who have information regarding sexual harassment or sexual misconduct are required to report the information to CCR or a designated Title IX Coordinator or Liaison. (Visit ccr.wsu.edu/reporting-requirements for more info).
University Support and Response for Discrimination and Harassment
Discrimination, discriminatory harassment, sexual harassment, and sexual misconduct (including stalking, intimate partner violence, and sexual violence) are prohibited at Washington State University (see Executive Policy 15 WSU Policy Prohibiting Discrimination and Harassment, the WSU Standards of Conduct for Students, and relevant employee manuals). WSU has instituted procedures to respond to violations of these laws and standards, programs aimed at the prevention of such conduct, and intervention on behalf of victims.
If you are in immediate danger, call 911.
If you are experiencing sexual assault, domestic violence, stalking, discrimination or harassment, you have support and options. If you share information with WSU faculty and/or state, please know that they may be required to reach out to the Title IX Coordinator in WSU Compliance and Civil Rights (CCR), and CCR will reach out to you with information about on and off campus reporting options and resources. CCR is a system-wide resource (all campuses) which is available for intake consultations for you to learn more about available support.
You can also speak to a victim advocate, a medical provider, or counselor confidentially about your concerns. Advocates help survivors of crime determine their own needs in regards to their physical and emotional health, reporting options, and academic concerns. At no cost, advocates connect survivors to campus and community services, and provide accompaniment to important appointments (court, hospital, and police) and support throughout the process. For a list of confidential victim advocates and medical providers, please visit CCR Resources.
WSU Police Department (WSU PD) officers and campus security will treat victims of sexual assault, domestic violence, stalking, hate crimes, and other crimes with respect and dignity. WSU PD, campus security departments, CCR, and victim advocates can also help you with safety planning.
Safety and Emergency
Classroom and campus safety are of paramount importance at Washington State University, and are the shared responsibility of the entire campus population. WSU urges students to follow the “Alert, Assess, Act,” protocol for all types of emergencies and the “Run, Hide, Fight” response for an active shooter incident. Remain ALERT (through direct observation or emergency notification), ASSESS your specific situation, and ACT in the most appropriate way to assure your own safety (and the safety of others if you are able).
- Campus Lock Down – Exterior doors will lock.
- Apply “RUN-HIDE-FIGHT” personal safety protocol.
- If sheltered or hiding; silence electronics, turn out lights, stay away from windows, barricade or lock doors, make a plan to fight if necessary.
- Active Shooter Training links:
- Apply “RUN-HIDE-FIGHT” personal safety protocol
- If sheltered or hiding; silence electronics, turn out lights, stay away from windows, barricade or lock doors, make a plan to fight if necessary
Please sign up for emergency alerts on your account at MyWSU. For more information on this subject, campus safety, and related topics, please view the FBI’s Run, Hide, Fight video and visit the WSU safety portal.
WSU Vancouver Police: (360) 546-9001
Emergency Notification Network
WSU Vancouver has made an emergency notification system available for faculty, students, and staff. Please register at MyWSU with emergency contact information (cell, email, text, etc.). You may have been prompted to complete emergency contact information when registering for classes at RONet. In the event of a building evacuation, refer to the map at each classroom entrance, which shows the evacuation point for each building. Finally, in case of class cancellation campus-wide, please check local media, the WSU Vancouver website and/or the FlashAlert Newswire. Individual class cancellations may be made at the discretion of the instructor. Each individual is expected to make the best decision for their personal circumstances, taking safety into account. For additional safety plan information, please click here.
Inclement Weather Policy
In the event that an adverse weather event (e.g., snow or ice) or natural hazard that poses a safety risk occurs, you should take personal safety into account when deciding whether you can travel safely to and from campus, taking local conditions into account. If campus remains open and your instructor decides to cancel the face-to-face meeting and substitute an alternative learning activity, you will be notified by your instructor via email or through the course Slack channel within a reasonable time after the decision to open or close campus has been made. Instructions regarding any alternative learning options or assignments will be communicated in a timely manner. If travel to campus is not possible due to adverse regional conditions, allowances to course attendance policy and scheduled assignments, including exams and quizzes, will be made. Students who attempt to gain advantage through abuse of this policy (e.g., by providing an instructor with false information) may be referred to the Center for Community Standards for disciplinary action. If a student encounters an issue with an instructor, the student should first talk with the instructor. If the issue cannot be resolved, the student should follow the reporting violations of policies outlined on the student affairs website.
WSU Vancouver Campus Emergency Links
During adverse weather conditions when C-Tran is operating on snow routes, the WSU Vancouver campus will not be served as the snow route ends at 20th Ave. More information on bus routes and C-Tran scheduling at their website.
WSU Vancouver Home Page
Announcements and Alerts
Service/Emotional Support Animal Guidelines
University policies on service animal and emotional support animals are available at: https://access.wsu.edu/service-animals/. Pets are not allowed on campus. Emotional support animals are not allowed in public buildings or in classrooms. Trained service animals are allowed in classrooms. If you have questions about animals on campus, please contact the university ADA Coordinator (https://access.wsu.edu/ada-coordinator/) and refer to Executive Policy 39 Service and Support Animal Police found at:https://access.wsu.edu/service-animals/.
Academic Complaint Procedures
Following Academic Regulation 104, students having complaints about instruction or grading should attempt to resolve those issues directly with the instructor. If that fails, the student should send an email to the instructor using his or her official WSU email account no later than 20 business days following the end of the semester. This email should briefly outline the complaint and be copied to the chairperson of the academic department.
If the complaint is not resolved with the instructor within 20 business days of sending the email, then the student may work directly with the chairperson of the academic department in which the course is offered. The chair’s decision shall be rendered within 20 additional business days.
After the chair’s decision, the student or the instructor may appeal to the academic college Dean’s Office. Complaints must be presented in writing to the college dean within 20 business days of the chair’s decision. The written statement should describe the complaint, indicate how it affects the individual or unit, and include the remedy sought from the college dean. The decision of the college dean is the final step and shall be made within 20 business days.
At the campuses other than Pullman, the procedure is identical except that the program leader shall substitute for the department chair, and the campus chancellor or his or her designee shall substitute for the college dean, if the department chair and/or the college dean is not located on that campus.
The University Ombudsman is available at any stage for advice or assistance in resolving academic complaints.


What to do when oil hits $100 a barrel
Congress must be bolder in forcing oil substitutes for transportation. It did that for electric utilities.
For the first time, oil prices have nosed above $100 a barrel. Gasoline is higher by 73 cents a gallon from a year ago. In past decades, such price jumps brought a knee-jerk reaction to conserve or to find more oil. The world has done both. Yet prices continue to rise. So what's left to do?
Congress tried to mandate more conservation last month when it insisted on better fuel efficiency in automobiles (from 25 to 35 miles per gallon by 2020). But some evidence suggests that better gas mileage creates an incentive for people to drive more, or even faster.
Consumers have also seen fuel prices go down for long stretches – just nine years ago, oil was at $10.35 a barrel. Making expensive investments in conservation or alternative transportation makes little sense to many. Ever since the oil shocks of the 1970s that saw prices rise to levels well above costs of production, Saudi Arabia has often jerked around prices to keep the world addicted to oil.
And in recent years, large, poor countries with a growing middle class, such as China, have jumped into the car culture. That has pushed up demand to the point that OPEC and the private oil industry can barely meet it. New oil fields are more difficult to find and to tap, and much of the oil is controlled by authoritarian governments that aren't very efficient at exploiting it.
So thin are supplies that market concerns over interruptions now account for much of today's higher prices. The latest upswings, for instance, were caused by tensions in Nigeria and Pakistan, bad weather in Mexico, and China's refineries running full tilt.


The purpose of this post is to provide some clues of the population growth impact on the environment.
Nowadays the total human population on the Earth is currently estimated to be 6.92 billion. Human population is increasing with tremendous growth rate and scientists believed that in 50 years the number will reach to 10 billion as we can see on the graph below. So with the limited carrying capacity of the earth the problem of the overpopulation is obviously unavoidable. Carrying capacity is the maximum population size of the species that the environment can sustain.
Causes that increase the human population.
The basic factors that can determine the population growth are the birth and immigration rates that increase the size of the population and on the other side the death and emigration rates that decrease the size. So an easy way to calculate these rates is the specific formula:
Population Growth = Birth rates – Death rates + Immigration – Emigration.
Population growth theories.
Cornucopians are futurist who believe that human through the continued progress and the advances in technology will manage to face the problem of the over-population. Fundamentally they believe that there is enough matter and energy on the Earth to provide for the estimated peak population of about 9.22 billion in 2075.
Cassandras on the other side they believe that the overpopulation of the earth in the future will bring the world to an end. The earth will not be able to sustain the size of the population and unavoidably will have the extinction of the natural resources such as food and water and so on the end of the human species.
Now as far as my opinion, I believe that indeed humanity will face the problem of the overpopulation in the future and this will yield two different problems. The first is the matter of extinction of the natural sources and the second is the matter of extinction of space. So I think the problem of natural sources will be overcome with the rapidly growth of the technology. For example the creation of artificial products without the use of the natural materials such as pills that will replace the need of food and water by the human. But on the other side I believe that the matter of space extinction on the earth can be a vital problem in the future. The uncontrolled population growth will limited the space of living for every individual. Even nowadays we have extremely overcrowded cities that people face the problem of limited space and this will be even worst with the continuous population growth.
Paul Ralph Ehrlich is an American biologist and educator who is the Bing Professor of Population Studies in the department of Biological Sciences at Stanford University and president of Stanford’s Center for Conservation Biology. He is known better as an ecologist and a demographer, specifically for his warnings about unrestricted population growth and limited resources. Ehrlich became well-known after publication of his controversial 1968 book The Population Bomb. (3) Ehrlich through his book focused to the mass starvation of humans in the 1970s and 1980s due to overpopulation, and advocated immediate action to limit population growth. The book has been criticized in recent decades for its alarmist tone and inaccurate predictions. Ehrlich stand by the basic ideas in the book, stating in 2009 that “perhaps the most serious flaw in The Bomb was that it was much too optimistic about the future” and believe that it achieved their goals because “it alerted people to the importance of environmental issues and brought human numbers into the debate on the human future.” (4) However Ehrlich made a number of specific predictions that did not come to pass, for which he have received criticism. He have acknowledged that some predictions were incorrect but maintain that his general argument remains intact, that his predictions were merely illustrative, that his warnings caused preventive action, or that many of his predictions may yet come true.
The Book –>
The I PAT equation.
I=PAT is the lettering of a formula put forward to describe the impact of human activity on the environment.
I = P × A × T
- Human Impact (I) on the environment equals the product of P= Population, A= Affluence, T= Technology. This describes how our growing population, affluence, and technology contribute toward our environmental impact.
The equation was developed in the 1970s during the course of a debate between Barry Commoner, Paul R. Ehrlich and John Holdren. Commoner argued that environmental impacts in the United States were caused primarily by changes in its production technology following World War II, while Ehrlich and Holdren argued that all three factors were important and emphasized in particular the role of population growth. The equation can aid in understanding some of the factors affecting human impacts on the environment. (7)
How The IPAT equation applies in various countries.
United States – The US with a population around 300 millions has a huge impact on the environment. The two major factors of the US is technology and affluence. By having these two factors on the highest grade, a developed country like the US can determine and influence the formation of the environment. Especially if the country’s consumption rate is as big as the US.
China – China being the most populated country in the world, having more than 1.4 billions, it is obvious that can affect in a big percentage the environment. China faces the problem of the overpopulation and that’s why is used strict governmental policies to reduce the growth of the population. The one child policy that China uses is an effective way to stabilize and control the population growth. So despite the huge technological growth that China has, the decrease of the population will eventually decrease China’s impact on the environment.
Greece – Greece’s population reaches around to 11 billion and in connection to a low affluence and even lower technological progress means that the impact of the country on the environment is balance between the average and under the average rate.
Hans Rosling is a Swedish medical doctor, academic, statistician and public speaker. He is Professor of International Health at Karolinska Institute and co-founder and chairman of the Gapminder Foundation, which developed the Trendalyzer software system. Rosling’s research has also focused on different links between economic development, agriculture, poverty and health in Africa, Asia and Latin America. He has been health adviser to WHO, UNICEF and several aid agencies. Also as chairman of Karolinska International Research and Training Committee (1998–2004) he started health research collaborations with universities in Asia, Africa, the Middle East and Latin America. He started new courses on Global Health and co-authored a textbook on Global Health that promotes a fact-based world view. (8)
However it is interesting also to mention how Rosling presents and mixed many factors that contribute to the development of a country such as of economy, health and education.Rosling also aim on the interrelation of the developing countries with the developed and how these different economies are set up to achieve the specific progress. Such as the example of China that first developed a health policy before the economical growth that china has nowadays.


Passenger vehicles must know how to share the road safely with large trucks and buses – and a campaign by the U.S. Department of Transportation’s Federal Motor Carrier Safety Administration (FMCSA) emphasizes that need.
The Our Roads, Our Safety initiative is intended to reduce crashes, injuries and fatalities involving large trucks and buses,” according to said FMCSA Deputy Administrator Daphne Jefferson.
The American Bus Association, AAA and the American Trucking Association have joined with FMCSA in the effort to educate all pedestrians, bicyclists, passenger vehicle drivers and commercial motor vehicle (CMV) drivers on how to better share the roadways and improve safety for all.
There are several simple actions passenger vehicle drivers should take while sharing the road with large trucks and buses:
- Stay out of the “No Zones” or blind spots at the front, back and sides of the vehicle
- Make sure they can see the driver in the mirror before safely passing
- Don’t cut in close while merging in front of a CMV
- Stay back a safe distance to avoid being in the blind spot
- Anticipate wide turns and consider larger vehicles may require extra turning room
- Stay focused on the road and avoid distractions
- Lastly, be patient driving around large trucks and buses
In addition to these tips, parents and teachers can involve children aged 5-12 in highlighting the importance of road safety by participating in the Road Safety Art Contest. The contest allows children in kindergarten through sixth grade to use their creativity and talent to help raise awareness of how to stay safe on the roads.
Visit www.sharetheroadsafely.gov to get involved. Learn more and share information about how passenger vehicle drivers, CMV drivers, bicyclists and pedestrians share a responsibility for making our roads a safer place for everyone.


Interfacing with Nature
Even before the Internet of Things becomes reality, the Internet of Animals is already proclaimed. Big animal data is collected in real time, and people follow individual wolves, birds and sharks online. At the same time, nature moves physically into the urbanised areas of people.
Since the industrial revolution there has been a growing separation between nature and the human living environment. Now, with digital technologies, there are new possibilities and attempts to bridge these separations again and making contact.
Does this technological bridge imply a de-sensualisation when experiencing nature? How could such experiences look like? Can we still escape into a nature that has become transparent? And what would the animals get out of it?
In this class we look at the different forms of interaction between people and nature, at forms of plant communication, go on expeditions to explore forest and urban eco systems, set up electro-botanical experiments and make contact.
FH Potsdam / Design dept., spring term 2015


Bsal animations and videos
Educational videos on Bsal were recently created to provide an overview of
- the etiology and epidemiology of Bsal,
- the clinical signs in different amphibian species, pathogenesis and pathology,
- the diagnostic methods
- possible treatment options
- and preventive measures that can be taken by hobbyists and naturalists.
At the European Herpetological Congress in Salzburg in 2017 two animations on Bsal were presented for the very first time. Both animations are available in 18 European languages (and counting). These clips were created by several European organisations and issued by the European Commission. Aims: delineate the current range of Bsal in Europe, create an Early Warning System, development of an emergency action plan (short term) and to provide proofs of concept for sustainable long-term mitigation measures.
Not seeing the subtitles automatically? Click on the subtitle icon in the bottom right corner of the video and select the preferred language.
In addition, an instructional video was created outlining the hygiene protocol for fieldwork, step-by-step:
Bsal poses a threat to salamanders in the whole of Europe so please share these videos widely!


F.D.A. Says Source of Tainted Tomatoes May Stay a Mystery
The Food and Drug Administration may never be able to pinpoint the origin of salmonella-tainted tomatoes that have sickened hundreds of people, an agency official said Wednesday.
“We may not ultimately know the farm where these came from,” Dr. David Acheson, the agency’s associate commissioner for foods, told reporters in a conference call. “Some trace-backs that we thought were looking pretty good have been falling apart.”
Dr. Acheson said he remained optimistic, but added, “I’m trying to be realistic.”
The agency is investigating a cluster of nine people who ate tomatoes at the same restaurant chain, but has not disclosed the chain’s name or location.
Also on Wednesday, the Centers for Disease Control and Prevention raised its count of people who have become sick from eating raw tomatoes, to 383 in 30 states and Washington, D.C., up from 277 cases in 28 states and Washington.
And the New York City Department of Health and Mental Hygiene said it had confirmed six new cases in addition to a previously known one. More cases might still be confirmed, the department said.
An official at the disease centers said the increase in national cases was mostly from greater surveillance at the state level and positive identifications of salmonella samples in recent tests. At least 48 people have been hospitalized.
The tainted tomatoes were probably grown in Mexico or central or southern Florida, Dr. Acheson said. The agency is looking for the genetic fingerprint of the rare strain of salmonella responsible for the illnesses, tracing the tomatoes back through the supply chain.
Dr. Robert Tauxe of the disease centers said the process would require “finding someone who not only remembers what they had to eat and where they ate it, but someone who doesn’t have tomatoes more than once a day.”
Dr. Tauxe added, “We do not think the outbreak is over.”


Dialectical behavior therapy is an evidence-based psychotherapy treatment approach that was developed by Marsha M. Linehan, in the late 1980s. It was originally developed, to help treat chronically suicidal individuals diagnosed with borderline personality disorder (BPD), and is now recognized as an effective therapeutic method for treating a wide range of other mental health conditions, such as depression, anxiety, post-traumatic stress disorder (PTSD), substance use disorder (SUD), eating disorders, and more. DBT is founded on the principles of cognitive-behavioral therapy (CBT) and blends Eastern mindfulness techniques such as awareness, mindfulness, and attentiveness to current situations and emotional experiences to encourage acceptance and change. DBT is comprised of three different therapy settings, including weekly individual psychotherapy sessions, weekly DBT skills training group therapy sessions, and as-needed phone coaching to provide additional support between weekly individual and group sessions. Dialectical behavior therapy helps teach teenagers healthy coping mechanisms and useful techniques for managing stress, regulating emotions, and improving relationships with others.
DBT Skills Training Group Sessions
Research has found that the “DBT skills training group is effective in reducing symptoms for both adults with borderline personality disorder and adolescents with oppositional defiant disorder.” The DBT skills training group sessions are facilitated by a qualified mental health professional who will follow the lessons provided in the DBT curriculum. Each session generally lasts about two hours long. These group sessions are focused on enhancing the capabilities of each participant by teaching behavioral skills related to the four modules that make up the pillars of DBT. Each of these four key areas focuses on distinct and specific skills that build upon each other and are integral to one’s healing process. The modules of DBT include the following, provided by the Linehan Institute:
- Core Mindfulness (focusing skills): the practice of being fully aware and wholly present in the current moment
- Distress Tolerance (crisis survival skills): learning tools and techniques to accept, find meaning through, and tolerate distress
- Interpersonal Effectiveness (relationship/ people skills): learning assertive communication methods that enable an individual to engage with others in a way that maintains self-respect and simultaneously strengthens relationships
- Emotion Regulation (de-escalation skills): learning to recognize, label, and adjust emotions to assist in regulating emotions and subsequently changing reactions to events
These group sessions offer participants an emotionally safe environment to begin to implement the DBT skills alongside other teenagers working on similar issues. Group members are encouraged to share their experiences and provide mutual support, which can be invaluable to the therapeutic process. The work that occurs during the DBT skills training group sessions continues, as homework that corresponds to the DBT skills taught or visited during each DBT group session is regularly assigned.
The information above is provided for the use of informational purposes only. The above content is not to be substituted for professional advice, diagnosis, or treatment, as in no way is it intended as an attempt to practice medicine, give specific medical advice, including, without limitation, advice concerning the topic of mental health. As such, please do not use any material provided above to disregard professional advice or delay seeking treatment.


Working in the Cold
Telling everyone to stay out of the cold is good advice, but what happens when your job demands you be outside for extended periods of time? Workers in such industries as construction, commercial fishing, and agriculture need to be especially mindful of the weather, its effects on the body, proper prevention techniques, and treatment of cold-related disorders.
The following recommendations may help to reduce the number of cold-related problems workers experience during winter months.
- When possible, try to work in an area sheltered from the wind.
- Dress appropriately. Wear at least three layers of clothing: an outer layer to break the wind and allow some ventilation (like gortex or nylon); a middle layer of wool, down, or synthetic pile to absorb sweat and retain insulating properties when wet; and an inner layer of cotton or synthetic weave to allow ventilation and escape of perspiration.
- Layer clothing to create air pockets that help retain body heat. Layering also makes adapting to changes in weather and level of physical exertion easier.
- Keep a change of clothing available in case your work clothes get wet. If your clothes get wet, you should try to change into dry clothes as soon as possible.
- Pay special attention to protecting your feet, hands, head, and face. Your head should be covered (up to 40% of your body heat can be lost when your head is exposed). Fingers and hands lose their dexterity at temperatures below 59°F. Find gloves that will allow you to perform the tasks you need to perform and remember to put dry gloves on if your gloves get wet.
- Wear boots or shoes that protect against cold and dampness. Footwear needs be insulated and fit comfortably with several layers of socks.
- Avoid wearing dirty or greasy clothing because they have poor insulating properties and will allow you to get cold faster than clean clothing.


Many of us try to drink the recommended 6-8 glasses of water per day because we’ve heard it helps with our skin and other aspects of health. But you may be even more vigilant about keeping that Nalgene filled if you knew that even the slightest dehydration can affect your mental awareness.
Business Insider’s Drake Baer takes a look at some of the studies related to hydration and brain functionality, and the takeaway is clear: Drink more water if you want to perform your best at anything, even if it involves spreadsheets instead of wind sprints.
As University of Texas neuroscientist Joshua Gowin writes in Psychology Today, “Brain cells require a delicate balance between water and various elements to operate, and when you lose too much water, that balance is disrupted. Your brain cells lose efficiency.”
Staying properly hydrated is just as important for those who work all day at a computer, as it is for marathon runners.
In fact, losing just 1% of body weight due to not drinking enough water can decrease both concentration and alertness, reports a separate piece in Psychology Today. Simply providing access to water has been shown to increase both attention and memory in school-aged children, who are generally more prone to dehydration than adults.
Dr. Gowin agrees: “Dehydration can impair short-term memory function and the recall of long-term memory. The ability to perform mental arithmetic, like calculating whether or not you’ll be late for work if you hit snooze for another 15 minutes, is compromised when your fluids are low.”
If that’s not reason enough for you to drink more water, consider a 2012 study from the University of Connecticut’s Human Performance Laboratory. Tests gauged the comparative abilities of both properly hydrated and dehydrated subjects at several cognitive tests.
This study found that mild levels of dehydration in young women seemed to produce greater levels of headaches, fatigue, and difficulty concentrating, as well as bigger mood swings—but no measurable decrease in cognitive function. However, young men experienced cognitive issues, including problems with vigilance, memory, anxiety, and tension.
Study co-author Harris Lieberman noted, “Dehydration affects all people, and staying properly hydrated is just as important for those who work all day at a computer, as it is for marathon runners.”
Lieberman’s partner on this study, Lawrence E. Armstrong, added, “Our thirst sensation doesn’t really appear until we are 1 or 2% dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform.”
So really, the key is sipping water consistently throughout the day, before you notice that you’re thirsty.
And what about that old wisdom that coffee dehydrates you? That’s not necessarily the case, according to a different study from the University of Birmingham.
Study author Sophie Killer said, “It’s well understood that if you drink coffee habitually you can develop a tolerance to the potential diuretic effects of coffee.”
Phew. So it’s settled: More water and more coffee.
[via Business Insider]


Robert Steinke of Speed Up suggested using a self pressurizing propellant to drive a pump for a less pressurized propellant. In this case nitrous at about 800 psi is vaporized to pump a fuel up to some pressure in between the two. Say a pressure drop of two for the nitrous through the turbine drops it to 400 psi while pumping the fuel from 200 or less up to 400 psi. There was a some discussion of it on A Rocket. One of the comments suggested that since nitrous is already the bulk of the propellant, just pressurize the fuel and be done with it.
Being the kind of person that steals and modifies ideas as a matter of habit, I decided to see what I could do with the basic concept.Taking a self pressurizing propellant to drive a pump that reduces over all system mass, and hopefully operating cost.
Helium is the pressurant gas of choice for any that require performance. Unfortunately it seems that it is becoming somewhat more expensive and harder to order as the decades roll on. Also, it must be stored as a gas which means a relatively large pressure container. Self pressurizing propellants can get by without helium at the expense of considerably more mass of pressurant gas at the end of the burn. With a self pressurizing propellant driving the turbine after a run through the cooling jacket, It may be possible to do without helium altogether without the mass penalty of heavier gasses for pressurant.
Hopefully my cartoons will be better when I get another computer in a week or so. My desktop computer doesn’t save sketches in a manner that the blog will accept, and my laptop does these tiny things that even I can’t read.
Anyway, a small pressure sphere of LH2 contains less than 1% of the total propellant on board. The liquid hydrogen at 6,000 psi is sent through the cooling jacket to cool the engine and gain energy to drive the turbine. The hot hydrogen gas drives the turbine with a pressure drop of about ten from 5,400 psi after a 10% loss in the cooling phase to 540 or so psi which exhausts into the combustion chamber. The LOX and Kerosene is pumped up to nearly 600 psi to allow for pressure drop through the injectors. With a chamber pressure at 500 psi in a sorta expander cycle Isp will be a bit higher than most pressure fed engines. Mixture of propellants is less than 1LH burns with less than 6LOX+28Kero+65LOX if I have it guestimated correctly.
Low pressure tanks for the Kero/LOX at a bit less than a cubic meter per metric ton would be partnered with about about 100 liters or so of LH2 in high pressure spheres. System dry mass should be less than that with the helium spheres and medium pressure tanks of most current set ups. A quality trade study will probably find the sweet spot to be less pressure than I am suggesting on this first pass. More LH2 at a 1,500 psi would feel like a better solution as long as it didn’t go overboard and become a pressure fed hydrogen rocket.
Kerosene impeller tip speed will be on the order of 350 ft/sec with LOX impeller at about 290 ft/sec. For perspective, a 2″ disk on a 35,000 rpm Dremel tool has a tip speed of 300 ft/sec. My 14″ demolition saw at 6,000 rpm has a tip speed of 350 ft/sec. Most people worry about the turbine. This one is driven by hydrogen that is fairly warm though well below turbine temperatures on almost any application you can think of. It will require a multistage turbine to extract the energy both from the low turbine speeds and the very high pressure drop.
A variation that would get more turbine drive with less hydrogen mass would be to discharge the hydrogen gas into the expansion nozzle as extension skirt cooling. Prior art suggests that the Isp hit is not that severe, and pressure drop down to 50 psi or so is possible. With a turbine exhaust in the 50 psi range, the hydrogen spheres might optimize toward the 1,000 psi range.


More often than not the discipline of history seems to swing between the true and trivial (or perhaps more precisely, picayune), and grand narratives which emphasize a nearly fictionalized story. In some ways this is not entirely a problem. When teaching young children the history of the United States a punctilious adherence to fact is essential, but, one can not deny that the selection of topicality can sway and shade the direction of the lessons learned. But far too often this ideological element of the historical narrative determines the central focus, rather than floating along the margins. With erudite command of detail historical scholars can, if they so choose, engage in a game of ideological sophistry, cultural flattery, and underhanded polemic. Both Howard Zinn and David Barton were and are players at this game. But there are still those who engage in the Sisyphean task of perceiving the world as it is, not as we would wish it to be, through the dark glass. Such a colossal enterprise, to ascertain the objective character of an exceedingly complex phenomenon, requires every tool at hand. Historians have traditionally been hunters of musty texts in neglected libraries, but they have on many an occasion received auxiliary data from scholars working in more material domains, such as archaeologists and engineers. Today you must add geneticists to the growing brigade of scholars attempting to excavate the past.
In truth the power of genetics is most evident and necessary in areas where history is silent, before written records can build a narrative skeleton in which we can play. Using both modern and ancient DNA samples the geneticists, working with archaeologists, can still make vague inferences where before there was only darkness. But illumination can be had even in time periods when historical records are quite good. Though the public understands evolution to transpire over eons, basic population genetic processes occur over a matter of generations, and so can give us fresh insight into dynamics which played out quite recently in time. A new paper in PLoS GENETICS, Reconstructing the Population Genetic History of the Caribbean, does just this. Obviously we already have a history of the Caribbean. As every schoolboy knows it began in 1492, and proceeded across the centuries as a palimpsest of European colonial powers, and later independent nations, rose and fell. But history is more than just wars, international congresses, and once-in-a-generation discoveries. It is the ebbing and flowing of peoples themselves in their aggregate masses. Conventional textual narratives and coarse archaeological inferences can get us rather far. See Charles C. Mann’s magisterial 1493 for an example. But historical population genetics goes a step further, as it attempts to infer demography through patterns of variation in genes, the most elemental instrumental variable for tracing demographic patterns one might imagine.
What the above paper does is reiterate, emphasize, and clarify, particular population genetic demographic events which have been suspected. First, the Amerindian populations were not static creatures in equilibrium with nature, but dynamic. There is clear evidence in these results that some groups migrated from South America to Central America, and especially the Caribbean. This is not unreasonable a priori, but far too often our stylized models presume the Amerindian population as a homogeneous, uniform, almost ahistorical substrate upon which European agency and African tragedy can unfold. But on the contrary, the peoples of the New World had their own history, oral as it may be. As you can see the Maya, one of the most iconic of Amerindian peoples, seem to exhibit some southern affinities, perhaps the result of an ancient “back migration.” If the Old World is any guide there may have been many forward and back migrations.
This ancient legacy is evident in the admixed populations, the Mestizos, Zambos, and Mulattos of the Greater Caribbean region. Looking in particular at the Puerto Rican and Dominican populations you see low, but significant, levels of admixture from specific native groups. One the one hand you may not be surprised, but it must be stated that before the genetic evidence there was much skepticism as to whether any Amerindian genetic heritage persisted in the populations of the Caribbean. A particular style of cultural/humanistic scholar intuited that perhaps an emphasis on indigenous ancestry was a mechanism for people of some African ancestry to deflect attention away from this aspect of their heritage because of the fraught history of slavery. Though the internal logic here seems reasonable, the empirical evidence makes it clear that the legacy of the Amerindians does persist in these islands, among these peoples. Their motive may have been unpalatable, but their argument was right.
Who were these Amerindian people? And how did they become integrated with the synthetic populations which came to dominate these islands? This is where textual history and genetics operate in a complimentary fashion. Both history and ethnography document mass population collapse in concert with an androcide of the Amerindians. By this, I mean that European males took Amerindian women as concubines, and engaged in de facto polygyny in the New World. Hernan Cortes, conqueror of the Aztecs, illustrates his phenomenon, as he had an illegitimate son, Martin Cortes, with his native translator, and later on a legitimate son, another Martin Cortes, with a Spanish noblewoman. This pattern of sexual liberty and license was common in the early years, and has been extensively documented by historians. It is a reason many anthropologists give for the relatively low rates of legitimacy in much of Latin America. And of course what applied to Amerindian females also applied to African females. What the genetics makes clear is that this asymmetric pattern of cultural power relations was demographically very significant. Populations with a near total lack of Amerindian and African Y chromosomal lineages, passed from father to son, may still have high levels of non-European mtDNA, passed from mother to daughter. In this study they also looked at the X chromosome, which spends 2/3 of its time in females, and did find an enrichment of Amerindian ancestry there as well.
But they didn’t just focus on the nature of admixture today, they inferred its history. The technique is rooted in basic concepts in genetics. When you have chromosomes come together from parents in a child, those are distinct and identical in nature to segments of ancestry one might find in parents. But genetic recombination in the next generation shuffles the segments, so that parental elements become mixed together on the same segment. When parents are from different geographic populations you see alternative segments of “ancestry tracts.” For example a chromosomal segment with alternative regions of European, Amerindian, and African, ancestry. Because there are only 20-30 recombination events per generation per individual the distribution of the length of these tracts is a function of the length of time since admixture. The early years after admixture will be characterized by long blocks of ancestry from one population, alternated with another. As time passes the segments will get smaller, and alternate much more rapidly. What the authors found was that indeed Amerindian segments exhibited the latter pattern, while European and African segments were more diverse in their distribution. The distinction was strongest in the Caribbean populations, but was evident elsewhere. The explanation is the one above. The early years of Iberian settlement were characterized by de facto polygyny and decimation of male Amerindians through enslavement (though there was population collapse more generally due to disease). Amerindian ancestry came in one singular pulse, and slowly dissipated and distributed itself through the population.
Finally, the results here also yield the finding that Latin American European ancestry seems to have diverged from its parent source. A detailed exploration of the technical issues can be found at the Haldane’s Sieve weblog, but I will say I am convinced that the authors have made a good, if not definitive, case for the proposition that the Latin American ancestral component is one which has diverged significantly. Again, the reason was listed above: de facto polygyny. This drives down the effective population, increases the drift, and skews the allele frequency distribution rapidly away from the source population. If this is a true result it shows us the possibilities for how new populations can arise through fission and rapid expansion. In particular, they may be male mediated. For this period, from 1500-1900, we have extensive documentation to corroborate the broad inferences made. But not so for many regions deep into the past. What these sorts of papers illustrate is the fine-grained power of genetics in shedding light on topics and issues which might otherwise have remained off limits. In particular genetics taps into some of the most primal activities of humankind, those that lead to procreation.
Citation: Moreno-Estrada A, Gravel S, Zakharia F, McCauley JL, Byrnes JK, et al. (2013) Reconstructing the Population Genetic History of the Caribbean. PLoS Genet 9(11): e1003925. doi:10.1371/journal.pgen.1003925


Summary of Alignment & Usability for Holt McDougal Mathematics | Math
The materials reviewed do not meet the expectations for alignment to the Common Core State Standards. The materials assess minimal grade appropriate topics. Approximately 20% of the content focuses on the major work. There is minimal supporting work enhancing the understanding of the major work in the standards. It would take more than 190 days to complete each course. The mathematics progression for the series is based on the National Council of Teachers of Mathematics Curriculum Focal Points instead of the CCSSM. Since the material does not meet the alignment standards for focus or coherence, it was not reviewed for rigor and the math practices.


We are living in an exciting time, where next-generation instruments and improved methods are leading to discoveries in astronomy, astrophysics, planetary science, and cosmology. As we look farther and in greater detail into the cosmos, some of the most enduring mysteries are finally being answered. Of particular interest are cosmic rays, the tiny particles consisting of protons, atomic nuclei, or stray electrons that have been accelerated to near the speed of light. These particles represent a major hazard for astronauts venturing beyond Earth’s protective magnetic field.
At the same time, cosmic rays regularly interact with our atmosphere (producing “showers” of secondary particles) and may have even played a role in the evolution of life on Earth. Due to the way they carry an electric charge, which scrambles their path as they travel through the Milky Way’s magnetic field, astronomers have been hard-pressed to find where cosmic rays originate. But thanks to a new study that examined 12 years of data from NASA’s Fermi Gamma-ray Space Telescope, scientists have confirmed that the most powerful originate from shock waves caused by supernova remnants.
The research was led by Ke Fang, an assistant professor with the Wisconsin IceCube Particle Astrophysics Center at the University of Wisconsin–Madison. She was joined by researchers from the Naval Research Laboratory, the Kavli Institute for Particle Astrophysics and Cosmology, the SLAC National Accelerator Laboratory, the Catholic University of America, and the Center for Research and Exploration in Space Science and Technology (CRESST) at NASA’s Goddard Space Flight Center. The paper that describes their findings recently appeared in the Physical Review Letters.
Mitigation against cosmic rays is one of the main considerations regarding future missions to the Moon and Mars. Like solar radiation, these high-energy particles pose a risk to astronaut health due to their effect on skin tissue and organs, but also from the “showers” of secondary particles they produce. This occurs when cosmic rays come into contact with our atmosphere, which produces lower-energy particles like neutrons or electrons, most of which are deflected off into space.
In space, however, cosmic rays produce showers after impacting with dense material – such as radiation shielding. Aboard the ISS, the impact of these rays creates showers of secondary particles that pass through the hull and fill the interior with lower-energy radiation. While ISS astronauts can limit their exposure to this radiation by rotating back to Earth, long-duration missions will not have that luxury. For crewed missions to Mars, astronauts will spend up to a year and a half in transit, plus several months on the Martian surface.
For this reason, knowing where cosmic rays come from and the kind of energies they can achieve is essential to developing improved protection and mitigation methods. For years, astronomers have been searching for where the highest-energy cosmic rays come from – those that exceed 1,000 trillion electron volts (PeV). These rays are ten times the energy generated by the Large Hadron Collider, the most powerful particle accelerator in the world, and are almost powerful enough to escape our galaxy.
“Theorists think the highest-energy cosmic ray protons in the Milky Way reach a million billion electron volts (or PeV) energies,” explained Fang in a recent NASA press release. “The precise nature of their sources, which we call PeVatrons, has been difficult to pin down.”
Results from the Fermi Space Telescope, showing G106.3+2 (and J2229+6114) in different energy ranges. Credit: NASA/Fermi/Fang et al. 2022
While it is difficult to track cosmic rays back to their origin, scientists have observed how they collide with interstellar gas near supernovae, which produces gamma rays (the highest energy light there is). From this, scientists suggested in a previous study (also based on Fermi data) that a significant fraction of primary cosmic rays originate from supernova explosions. For the sake of their study, Prof. Fang and her colleagues analyzed twelve years of Fermi data on SNR G106.3+2, a comet-shaped supernova remnant located about 2,600 light-years from Earth in the constellation Cepheus.
Using its primary instrument – the Large Area Telescope (LAT) – Fermi detected billion-electron-volt (GeV) gamma rays from within G106.3+2’s extended tail. Similar observations were conducted using the Very Energetic Radiation Imaging Telescope Array System (VERITAS) instrument at the Fred Lawrence Whipple Observatory in southern Arizona, the High-Altitude Water Cherenkov Gamma-Ray Observatory in Mexico, and the Tibet AS-Gamma Experiment in China. These observatories detected even higher-energy gamma rays reaching up to 100 trillion electron volts (TeV).
While cosmic ray particles would initially be trapped by the supernova remnant’s powerful magnetic fields, their path causes them to repeatedly cross the supernova’s shock wave. The particles gain speed and energy with each pass and eventually become too fast for the supernova remnant to hold onto them. At this point, they fly off into interstellar space, where they become incredibly difficult to trace back to their source. Co-author Henrike Fleischhack, a researcher from the Catholic University of America in Washington and NASA’s Goddard Space Flight Center:
“This object has been a source of considerable interest for a while now, but to crown it as a PeVatron, we have to prove it’s accelerating protons. The catch is that electrons accelerated to a few hundred TeV can produce the same emission. Now, with the help of 12 years of Fermi data, we think we’ve made the case that G106.3+2.7 is indeed a PeVatron.”
Illustration of NASA’s Fermi Gamma-ray Space Telescope at work. Credit: NASA GSFC
The supernova remnant is also notable for the pulsar J2229+6114 at its northern end, which astronomers think was born from the same supernova. This pulsar emits gamma rays as it spins, creating a strobing effect (like a lighthouse) that are typically less than 10 GeV in energy. These emissions are only visible during the first half of the pulsar’s rotation and did not present any significant interference for Fermi. Nevertheless, the research team was able to isolate G106.3+2.7’s higher-energy emissions by analyzing gamma rays arriving from the latter part of the cycle.
Their detailed analysis overwhelmingly shows that PeV protons are what was driving the powerful gamma-ray emissions they observed. This research has demonstrated that supernova remnants are the source of the most powerful cosmic rays in the Universe, though some questions remain. While astronomers have identified other potential sources of PeVatrons – including Active Galactic Nuclei (AGNs) – supernova remnants remain at the top of the list. Yet out of about 300 known remnants, only a few have been found to emit gamma rays at these energies.
“So far, G106.3+2.7 is unique, but it may turn out to be the brightest member of a new population of supernova remnants that emit gamma rays reaching TeV energies,” Fang added. “More of them may be revealed through future observations by Fermi and very-high-energy gamma-ray observatories.”
Further Reading: NASA, Physical Review Letters


Impedance matching is a fundamental aspect of RF design and testing; the signal reflections caused by mismatched impedances can lead to serious problems.
Matching seems like a trivial exercise when you’re dealing with a theoretical circuit composed of an ideal source, a transmission line, and a load.
Let’s assume that the load impedance is fixed. All we need to do is include a source impedance (ZS) equal to ZL and then design the transmission line so that its characteristic impedance (Z0) is also equal to ZL.
But let’s consider for a moment the difficulty of implementing this scheme throughout a complex RF circuit consisting of numerous passive components and integrated circuits. The RF design process would be seriously unwieldy if engineers had to modify every component and specify the dimensions of every microstrip according to the one impedance chosen as the basis for all the others.
Also, this assumes that the project has already reached the PCB stage. What if we want to test and characterize a system using discrete modules, with off-the-shelf cables as interconnects? Compensating for mismatched impedances is even more impractical under these circumstances.
The solution is simple: choose a standardized impedance that can be used in numerous RF systems, and ensure that components and cables are designed accordingly. This impedance has been chosen; the unit is ohms, and the number is 50.
The first thing to understand is that there is nothing intrinsically special about a 50 Ω impedance. This is not a fundamental constant of the universe, though you might get the impression that it is if you spend enough time around RF engineers. It is not even a fundamental constant of electrical engineering—remember, for example, that simply changing the physical dimensions of a coaxial cable will alter the characteristic impedance.
Nevertheless, 50 Ω impedance is very important, because it is the impedance around which most RF systems are designed. It is difficult to determine exactly why 50 Ω became the standardized RF impedance, but it’s reasonable to assume that 50 Ω was found to be a good compromise in the context of early coaxial cables.
The important issue, of course, is not the origin of the specific value but rather the benefits of having this standardized impedance. Achieving a well-matched design is vastly simpler because manufacturers of ICs, fixed attenuators, antennas, and so forth can build their parts with this impedance in mind. Also, PCB layout becomes more straightforward because so many engineers have the same goal, namely, to design microstrips and striplines that have a characteristic impedance of 50 Ω.
Before we move on, let’s be clear that not every high-frequency system or component is designed for 50 Ω. Other values could be chosen, and in fact 75 Ω impedance is still common. The characteristic impedance of a coaxial cable is proportional to the natural log of the ratio of the outer diameter (D2) to the inner diameter (D1).
This means that more separation between the inner conductor and outer conductor corresponds to a higher impedance. Greater separation between the two conductors also leads to lower capacitance. Thus, 75 Ω coax has lower capacitance than 50 Ω coax, and this makes 75 Ω cable more suitable for high-frequency digital signals, which require low capacitance in order to avoid excessive attenuation of the high-frequency content associated with the rapid transitions between logic low and logic high.
Considering how important impedance matching is in RF design, we shouldn’t be surprised to find that there is a specific parameter used to express the quality of a match. It is called the reflection coefficient; the symbol is Γ (the Greek capital letter gamma). It is the ratio of the complex amplitude of the reflected wave to the complex amplitude of the incident wave. However, the relationship between incident wave and reflected wave is determined by the source (ZS) and load (ZL) impedances, and thus it is possible to define the reflection coefficient in terms of these impedances:
If the “source” in this case is a transmission line, we can change the ZS to Z0.
In a typical system, the magnitude of the reflection coefficient is a number between zero and one. Let’s look at three mathematically straightforward situations to help us understand how the reflection coefficient corresponds to actual circuit behavior:
Another parameter used to describe impedance matching is the voltage standing wave ratio (VSWR). It is defined as follows:
VSWR approaches impedance matching from the perspective of the resulting standing wave. It conveys the ratio of the highest standing-wave amplitude to the lowest standing-wave amplitude. This video can help you visualize the relationship between impedance mismatch and the amplitude characteristics of the standing wave, and the following diagram conveys standing-wave amplitude characteristics for three different reflection coefficients.
VSWR is commonly expressed as a ratio. A perfect match would be 1:1, meaning that the peak amplitude of the signal is always the same (i.e., there is no standing wave). A ratio of 2:1 indicates that reflections have resulted in a standing wave with a maximum amplitude that is twice as large as its minimum amplitude.
by Luke James
by Luke James
by Robert Keim
by Robert Keim
In Partnership with Avnet Silica


|Helping the worlds poorest|
|Jeffrey Sachs, a top academic
economist, argues that rich countries must mobilise global science and technology to
address the specific problems which help to keep poor countries poor*
IN OUR Gilded Age, the poorest of the poor are nearly invisible. Seven hundred million people live in the 42 so-called Highly Indebted Poor Countries (HIPCs), where a combination of extreme poverty and financial insolvency marks them for a special kind of despair and economic isolation. They escape our notice almost entirely, unless war or an exotic disease breaks out, or yet another programme with the International Monetary Fund (IMF) is signed. The Cologne Summit of the G8 in June was a welcome exception to this neglect. The summiteers acknowledged the plight of these countries, offered further debt relief and stressed the need for a greater emphasis by the international community on social programmes to help alleviate human suffering.
The G8 proposals should be seen as a beginning: inadequate to the problem, but at least a good-faith prod to something more useful. We urgently need new creativity and a new partnership between rich and poor if these 700m people (projected to rise to 1.5 billion by 2030), as well as the extremely poor in other parts of the world (especially South Asia), are to enjoy a chance for human betterment. Even outright debt forgiveness, far beyond the G8s stingy offer, is only a step in the right direction. Even the call to the IMF and World Bank to be more sensitive to social conditions is merely an indicative nod.
A much more important challenge, as yet mainly unrecognised, is that of mobilising global science and technology to address the crises of public health, agricultural productivity, environmental degradation and demographic stress confronting these countries. In part this will require that the wealthy governments enable the grossly underfinanced and underempowered United Nations institutions to become vibrant and active partners of human development. The failure of the United States to pay its UN dues is surely the worlds most significant default on international obligations, far more egregious than any defaults by impoverished HIPCs. The broader American neglect of the UN agencies that assist impoverished countries in public health, science, agriculture and the environment must surely rank as another amazingly misguided aspect of current American development policies.
The conditions in many HIPCs are worsening dramatically, even as global science and technology create new surges of wealth and well-being in the richer countries. The problem is that, for myriad reasons, the technological gains in wealthy countries do not readily diffuse to the poorest ones. Some barriers are political and economic. New technologies will not take hold in poor societies if investors fear for their property rights, or even for their lives, in corrupt or conflict-ridden societies. The Economists response to the Cologne Summit (Helping the Third World, June 26th) is right to stress that aid without policy reform is easily wasted. But the barriers to development are often more subtle than the current emphasis on good governance in debtor countries suggests.
Research and development of new technologies are overwhelmingly directed at rich-country problems. To the extent that the poor face distinctive challenges, science and technology must be directed purposefully towards them. In todays global set-up, that rarely happens. Advances in science and technology not only lie at the core of long-term economic growth, but flourish on an intricate mix of social institutionspublic and private, national and international.
Currently, the international system fails to meet the scientific and technological
needs of the worlds poorest. Even when the right institutions existsay, the
World Health Organisation to deal with pressing public health disasters facing the poorest
countriesthey are generally starved for funds, authority and even access to the key
negotiations between poor-country governments and the Fund at which important development
strategies get hammered out.
|The ecology of underdevelopment|
|If it were true that the poor were
just like the rich but with less money, the global situation would be vastly easier than
it is. As it happens, the poor live in different ecological zones, face different health
conditions and must overcome agronomic limitations that are very different from those of
rich countries. Those differences, indeed, are often a fundamental cause of persisting
Let us compare the 30 highest-income countries in the world with the 42 HIPCs (see table). The rich countries overwhelmingly lie in the worlds temperate zones. Not every country in those bands is rich, but a good rule of thumb is that temperate-zone economies are either rich, formerly socialist (and hence currently poor), or geographically isolated (such as Afghanistan and Mongolia). Around 93% of the combined population of the 30 highest-income countries lives in temperate and snow zones. The HIPCs, by contrast, include 39 tropical or desert societies. There are only three in a substantially temperate climate, and those three are landlocked and therefore geographically isolated (Laos, Malawi and Zambia).
|Not only life but also death differs between temperate and tropical zones. Individuals
in temperate zones almost everywhere enjoy a life expectancy of 70 years or more. In the
tropics, however, life expectancy is generally much shorter. One big reason is that
populations are burdened by diseases such as malaria, hookworm, sleeping sickness and
schistosomiasis, whose transmission generally depends on a warm climate. (Winter may be
the greatest public-health intervention in the world.) Life expectancy in the HIPCs averages just 51 years, reflecting the interacting effects of
tropical disease and poverty. The economic evidence strongly suggests that short life
expectancy is not just a result of poverty, but is also a powerful cause of
All the rich-country research on rich-country ailments, such as cardiovascular diseases and cancer, will not solve the problems of malaria. Nor will the biotechnology advances for temperate-zone crops easily transfer to the conditions of tropical agriculture. To address the special conditions of the HIPCs, we must first understand their unique problems, and then use our ingenuity and co-operative spirit to create new methods of overcoming them.
Modern society and prosperity rest on the foundation of modern science. Global
capitalism is, of course, a set of social institutionsof property rights, legal and
political systems, international agreements, transnational corporations, educational
establishments, and public and private research institutionsbut the prosperity that
results from these institutions has its roots in the development and applications of new
science-based technologies. In the past 50 years, these have included technologies built
on solid-state physics, which gave rise to the information-technology revolution, and on
genetics, which have fostered breakthroughs in health and agricultural productivity.
|Science at the ecological divide|
|In this context, it is worth noting that the inequalities of income across the globe are actually exceeded by the inequalities of scientific output and technological innovation. The chart below shows the remarkable dominance of rich countries in scientific publications and, even more notably, in patents filed in Europe and the United States.|
|The role of the developing world in one sense is much greater than the chart
indicates. Many of the scientific and technological breakthroughs are made by poor-country
scientists working in rich-country laboratories. Indian and Chinese engineers account for
a significant proportion of Silicon Valleys workforce, for example. The basic point,
then, holds even more strongly: global science is directed by the rich countries and for
the rich-country markets, even to the extent of mobilising much of the scientific
potential of the poorer countries.
The imbalance of global science reflects several forces. First, of course, science follows the market. This is especially true in an age when technological leaps require expensive scientific equipment and well-provisioned research laboratories. Second, scientific advance tends to have increasing returns to scale: adding more scientists to a community does not diminish individual marginal productivity but tends to increase it. Therein lies the origin of university science departments, regional agglomerations such as Silicon Valley and Route 128, and mega-laboratories at leading high-technology firms including Merck, Microsoft and Monsanto. And third, science requires a partnership between the public and private sectors. Free-market ideologues notwithstanding, there is scarcely one technology of significance that was not nurtured through public as well as private care.
If technologies easily crossed the ecological divide, the implications would be less dramatic than they are. Some technologies, certainly those involving the computer and other ways of managing information, do indeed cross over, and give great hopes of spurring technological capacity in the poorest countries. Othersespecially in the life sciences but also in the use of energy, building techniques, new materials and the likeare prone to ecological specificity. The result is a profound imbalance in the global production of knowledge: probably the most powerful engine of divergence in global well-being between the rich and the poor.
Consider malaria. The disease kills more than 1m people a year, and perhaps as many as 2.5m. The disease is so heavily concentrated in the poorest tropical countries, and overwhelmingly in sub-Saharan Africa, that nobody even bothers to keep an accurate count of clinical cases or deaths. Those who remember that richer places such as Spain, Italy, Greece and the southern United States once harboured the disease may be misled into thinking that the problem is one of social institutions to control its transmission. In fact, the sporadic transmission of malaria in the sub-tropical regions of the rich countries was vastly easier to control than is its chronic transmission in the heart of the tropics. Tropical countries are plagued by ecological conditions that produce hundreds of infective bites per year per person. Mosquito control does not work well, if at all, in such circumstances. It is in any event expensive.
Recent advances in biotechnology, including mapping the genome of the malaria parasite, point to a possible malaria vaccine. One would think that this would be high on the agendas of both the international community and private pharmaceutical firms. It is not. A Wellcome Trust study a few years ago found that only around $80m a year was spent on malaria research, and only a small fraction of that on vaccines.
The big vaccine producers, such as Merck, Rhône-Poulencs Pasteur-MérieuxConnaught and SmithKline Beecham, have much of the in-house science but not the bottom-line motivation. They strongly believe that there is no market in malaria. Even if they spend the hundreds of millions, or perhaps billions, of dollars to do the R&D and come up with an effective vaccine, they believe, with reason, that their product would just be grabbed by international agencies or private-sector copycats. The hijackers will argue, plausibly, that the poor deserve to have the vaccine at low pricesenough to cover production costs but not the preceding R&D expenditures.
The malaria problem reflects, in microcosm, a vast range of problems facing the HIPCs in health, agriculture and environmental management. They are
profound, accessible to science and utterly neglected. A hundred IMF missions
or World Bank health-sector loans cannot produce a malaria vaccine. No individual country
borrowing from the Fund or the World Bank will ever have the means or incentive to produce
the global public good of a malaria vaccine. The root of the problem is a much more
complex market failure: private investors and scientists doubt that malaria research will
be rewarded financially. Creativity is needed to bridge the huge gulfs between human
needs, scientific effort and market returns.
|Promise a market|
|The following approach might work.
Rich countries would make a firm pledge to purchase an effective malaria vaccine for
Africas 25m newborn children each year if such a vaccine is developed. They would
even state, based on appropriate and clear scientific standards, that they would guarantee
a minimum purchase pricesay, $10 per dosefor a vaccine that meets minimum
conditions of efficacy, and perhaps raise the price for a better one. The recipient
countries might also be asked to pledge a part of the cost, depending on their incomes.
But nothing need be spent by any government until the vaccine actually exists.
Even without a vast public-sector effort, such a pledge could galvanise the world of private-sector pharmaceutical and biotechnology firms. Malaria vaccine research would suddenly become hot. Within a few years, a breakthrough of profound benefit to the poorest countries would be likely. The costs in foreign aid would be small: a few hundred million dollars a year to tame a killer of millions of children. Such a vaccine would rank among the most effective public-health interventions conceivable. And, if science did not deliver, rich countries would end up paying nothing at all.
Malaria imposes a fearsome burden on poor countries, the AIDS epidemic an even weightier load. Two-thirds of the worlds 33m individuals infected with the HIV virus are sub-Saharan Africans, according to a UN estimate in 1998, and the figure is rising. About 95% of worldwide HIV cases are in the developing world. Once again, science is stopping at the ecological divide.
Rich countries are controlling the epidemic through novel drug treatments that are too expensive, by orders of magnitude, for the poorest countries. Vaccine research, which could provide a cost-effective method of prevention, is dramatically under-funded. The vaccine research that is being done focuses on the specific viral strains prevalent in the United States and Europe, not on those which bedevil Africa and Asia. As in the case of malaria, the potential developers of vaccines consider the poor-country market to be no market at all. The same, one should note, is true for a third worldwide killer. Tuberculosis is still taking the lives of more than 2m poor people a year and, like malaria and AIDS, would probably be susceptible to a vaccine, if anyone cared to invest in the effort.
The poorer countries are not necessarily sitting still as their citizenry dies of AIDS. South Africa is on the verge of authorising the manufacture of AIDS medicines by South African pharmaceutical companies, despite patents held by American and European firms. The South African government says that, if rich-country firms will not supply the drugs to the South African market at affordable prices (ones that are high enough to meet marginal production costs but do not include the patent-generated monopoly profits that the drug companies claim as their return for R&D), then it will simply allow its own firms to manufacture the drugs, patent or no. In a world in which science is a rich-country prerogative while the poor continue to die, the niceties of intellectual property rights are likely to prove less compelling than social realities.
There is no shortage of complexities ahead. The world needs to reconsider the question
of property rights before patent rights allow rich-country multinationals in effect to own
the genetic codes of the very foodstuffs on which the world depends, and even the human
genome itself. The world also needs to reconsider the role of institutions such as the
World Health Organisation and the Food and Agriculture Organisation. These UN
bodies should play a vital role in identifying global priorities in health and
agriculture, and also in mobilising private-sector R&D towards
globally desired goals. There is no escape from such public-private collaboration. It is
notable, for example, that Monsanto, a life-sciences multinational based in St Louis,
Missouri, has a research and development budget that is more than twice the R&D budget of the entire worldwide network of public-sector tropical
research institutes. Monsantos research, of course, is overwhelmingly directed
towards temperate-zone agriculture.
|People, food and the environment|
|Public health is one of the two
distinctive crises of the tropics. The other is the production of food. Poor tropical
countries are already incapable of securing an adequate level of nutrition, or paying for
necessary food imports out of their own export earnings. The HIPC population
is expected to more than double by 2030. Around one-third of all children under the age of
five in these countries are malnourished and physically stunted, with profound
consequences throughout their lives.
As with malaria, poor food productivity in the tropics is not merely a problem of poor social organisation (for example, exploiting farmers through controls on food prices). Using current technologies and seed types, the tropics are inherently less productive in annual food crops such as wheat (essentially a temperate-zone crop), rice and maize. Most agriculture in the equatorial tropics is of very low productivity, reflecting the fragility of most tropical soils at high temperatures combined with heavy rainfall. High productivity in the rainforest ecozone is possible only in small parts of the tropics, generally on volcanic soils (on the island of Java, in Indonesia, for example). In the wet-dry tropics, such as the vast savannahs of Africa, agriculture is hindered by the terrible burdens of unpredictable and highly variable water supplies. Drought and resulting famine have killed millions of peasant families in the past generation alone.
Scientific advances again offer great hope. Biotechnology could mobilise genetic engineering to breed hardier plants that are more resistant to drought and less sensitive to pests. Such genetic engineering is stymied at every point, however. It is met with doubts in the rich countries (where people do not have to worry about their next meal); it requires a new scientific and policy framework in the poor countries; and it must somehow generate market incentives for the big life-sciences firms to turn their research towards tropical foodstuffs, in co-operation with tropical research centres. Calestous Juma, one of the worlds authorities on biotechnology in Africa, stresses that there are dozens, or perhaps hundreds, of underused foodstuffs that are well adapted to the tropics and could be improved through directed biotechnology research. Such R&D is now all but lacking in the poorest countries.
The situation of much of the tropical world is, in fact, deteriorating, not only because of increased population but also because of long-term trends in climate. As the rich countries fill the atmosphere with increasing concentrations of carbon, it looks ever more likely that the poor tropical countries will bear much of the resulting burden.
Anthropogenic global warming, caused by the growth in atmospheric carbon, may actually benefit agriculture in high-latitude zones, such as Canada, Russia and the northern United States, by extending the growing season and improving photosynthesis through a process known as carbon fertilisation. It is likely to lower tropical food productivity, however, both because of increased heat stress on plants and because the carbon fertilisation effect appears to be smaller in tropical ecozones. Global warming is also contributing to the increased severity of tropical climatic disturbances, such as the one-in-a-century El Niño that hit the tropical world in 1997-98, and the one-in-a-century Hurricane Mitch that devastated Honduras and Nicaragua a year ago. Once-in-a-century weather events seem to be arriving with disturbing frequency.
The United States feels aggrieved that poor countries are not signing the convention on
climatic change. The truth is that these poor tropical countries should be calling for
outright compensation from America and other rich countries for the climatic damages that
are being imposed on them. The global climate-change debate will be stalled until it is
acknowledged in the United States and Europe that the temperate-zone economies are likely
to impose heavy burdens on the already impoverished tropics.
|New hope in a new millennium|
|The situation of the HIPCs has become intolerable, especially at a time when the rich
countries are bursting with new wealth and scientific prowess. The time has arrived for a
fundamental re-thinking of the strategy for co-operation between rich and poor, with the
avowed aim of helping the poorest of the poor back on to their own feet to join the race
for human betterment. Four steps could change the shape of our global community.
First, rich and poor need to learn to talk together. As a start, the worlds democracies, rich and poor, should join in a quest for common action. Once again the rich G8 met in 1999 without the presence of the developing world. This rich-country summit should be the last of its kind. A G16 for the new millennium should include old and new democracies such as Brazil, India, South Korea, Nigeria, Poland and South Africa.
Second, rich and poor countries should direct their urgent attention to the mobilisation of science and technology for poor-country problems. The rich countries should understand that the IMF and World Bank are by themselves not equipped for that challenge. The specialised UN agencies have a great role to play, especially if they also act as a bridge between the activities of advanced- country and developing-country scientific centres. They will be able to play that role, however, only after the United States pays its debts to the UN and ends its unthinking hostility to the UN system.
We will also need new and creative institutional alliances. A Millennium Vaccine Fund, which guaranteed future markets for malaria, tuberculosis and AIDS vaccines, would be the right place to start. The vaccine-fund approach is administratively straightforward, desperately needed and within our technological reach. Similar efforts to merge public and private science activities will be needed in agricultural biotechnology.
Third, just as knowledge is becoming the undisputed centrepiece of global prosperity (and lack of it, the core of human impoverishment), the global regime on intellectual property rights requires a new look. The United States prevailed upon the world to toughen patent codes and cut down on intellectual piracy. But now transnational corporations and rich-country institutions are patenting everything from the human genome to rainforest biodiversity. The poor will be ripped off unless some sense and equity are introduced into this runaway process.
Moreover, the system of intellectual property rights must balance the need to provide incentives for innovation against the need of poor countries to get the results of innovation. The current struggle over AIDS medicines in South Africa is but an early warning shot in a much larger struggle over access to the fruits of human knowledge. The issue of setting global rules for the uses and development of new technologiesespecially the controversial biotechnologieswill again require global co-operation, not the strong-arming of the few rich countries.
Fourth, and perhaps toughest of all, we need a serious discussion about long-term finance for the international public goods necessary for HIPC countries to break through to prosperity. The rich countries are willing to talk about every aspect except money: money to develop new malaria, tuberculosis and AIDS vaccines; money to spur biotechnology research in food-scarce regions; money to help tropical countries adjust to climate changes imposed on them by the richer countries. The World Bank makes mostly loans, and loans to individual countries at that. It does not finance global public goods. America has systematically squeezed the budgets of UN agencies, including such vital ones as the World Health Organisation.
We will need, in the end, to put real resources in support of our hopes. A global tax on carbon-emitting fossil fuels might be the way to begin. Even a very small tax, less than that which is needed to correct humanitys climate-deforming overuse of fossile fuels, would finance a greatly enhanced supply of global public goods. No better time to start than as the new millennium begins.
*Jeffrey Sachs is director of the Centre for International Development and professor of international trade at Harvard University. A prolific writer, he has also advised governments of many developing and East European countries
Updated: 13 Aug 2007


A disadvantage of the offline technique above is that it is offline: the predictor does not adapt to the specific text file it sees. This limitation is not essential, however. It is straight-forward to construct an online variant of the approach. With the online variant, the predictor continues to learn during compression. The online variant proceeds like this: Both the sender and the receiver start with exactly the same initial predictor. Whenever the sender sees a new character, it encodes it using its current predictor. The code is sent to the receiver who decodes it. Both the sender and the receiver use exactly the same learning protocol to modify their weights. This implies that the modified weights need not be sent from the sender to the receiver and do not have to be taken into account to compute the average compression ratio. Of course, the online method promises higher compression ratios than the offline method.
The main disadvantage of both online and offline variants, however, is their computational complexity. The current offline implementation is clearly slower than conventional standard techniques, by about three orders of magnitude (but no attempt was made to optimize the code with respect to speed). And the complexity of the online method is even worse (the exact slow-down factor depends on the precise nature of the learning protocol, of course). For this reason, especially the promising online variants can be recommended only if special neural net hardware is available. Note, however, that there are many commercial data compression applications which rely on specialized electronic chips.
Among the methods presented in this paper, perhaps the most interesting way of using neural predictors for redundancy reduction is the one described in the next section.