Group items tagged

HIV jumped from apes to humans at least four times, as evidenced by genetically distinct groups of the virus that have been detected: M, N, O, and P. While N and P have had little impact, M is responsible for the pandemic affecting millions of individuals, and O has infected another 100,000.

Today, about one-tenth of the world's population are southpaws. Why are such a small proportion of people left-handed -- and why does the trait exist in the first place? Daniel M. Abrams investigates how the uneven ratio of lefties and righties gives insight into a balance between competitive and cooperative pressures on human evolution. Lesson by Daniel M. Abrams, animation by TED-Ed.

The SAT Biology E/M Subject Test is a multiple-choice test with 80 questions. You'll answer 60 multiple-choice questions on core principles in biology; then, depending on the additional subject matter you selected, you'll answer an additional 20 multiple-choice questions on Biology-E or Biology-M subject matter. You'll have one hour to answer all 80 questions.

We see color because of specialized light-sensing cells in our eyes called cones. One type, L-cones, sees the reds of strawberries and fire trucks; M-cones detect green leaves, and S-cones let us know the sky is blue. But vision scientists have now discovered that not all cones sense color (see video).

"There has been an over-reliance on male animals in preclinical research in the past, and as we have worked to study female specific physiological conditions, we became aware that even many aspects of our basic model of diet induced obesity are different in females," Erin Giles, assistant professor at Texas A&M University and lead author of the study, said in a press release.

Another case is ready for you: "East Meets West: An Infectious Disease Case" by Harry M. Zollars, Catherine D. Santanello, and Marcelo J. Nieto, Department of Pharmaceutical Sciences, Southern IL University Edwardsville.   Ying is sick and is progressively getting worse. His parents' clashing views on Eastern and Western medicine prevent them from agreeing on a course of treatment. As the case unfolds, students follow the progression of their son's illness. After a physician is finally seen and the results of tests are evident, students should be able to narrow the list of possible etiological agents and suggest a potential treatment. In addition, the students should integrate the different health beliefs into the final treatment as well as the aspects of patient counseling. The case works well as an interrupted case that can be assigned to individual students or student teams. This case is appropriate for graduate courses with a component in health care, therapeutics, medicinal chemistry, medicinal plants, microbiology, epidemiology, or cultural competency. Instructors can choose to focus only on the medical components of the case or incorporate the cultural and ethical aspects, depending on course goals and subject area.

A zebrafish model of a rare genetic disease has revealed an unexpected regulatory pathway for cholesterol absorption and processing. The findings, reported in the Journal of Molecular Medicine, were "quite surprising and have the potential to teach us about the basic physiology of cholesterol management," said Ela Knapik, M.D., associate professor of Medicine and Cell and Developmental Biology.

"Survival of the Fittest: Variations in the Clam Species Clamys sweetus" is a guided inquiry. This series of hands-on activities complements the HHMI DVD Evolution: Constant Change and Common Threads and requires simple materials such as M&Ms, Reese's Pieces, food storage bags, and paper cups. This activity has been designed to engage students in thinking about the mechanism of natural selection by encouraging them to formulate questions that can be answered through scientific investigation, data collection, and pattern recognition.

This case study introduces students to the true story of Caster Semenya, an outstanding female mid-distance runner from South Africa.  Caster won the 800 m race at the 2009 Track and Field World Championships when she was just 18. Since then, she has faced scrutiny about her sex and gender. Due to her high levels of endogenous testosterone, she was banned from running for almost a year by the track and field governing body, the IAAF. In this case study, students use information from news reports and Caster's appearance to determine the possible biological underpinnings likely responsible for her anatomy and physiology.  Students are also asked to consider if using circulating testosterone levels to determine if a female can race is a valid method of exclusion. This case asks students to think about how sex and gender are related, and pushes them to discuss societal implications of labeling both of these constructs as binary when in fact they are much better described as spectra.

5:35 minute video on ATP hydrolysis

The highly virulent Ebola virus has seen a few major outbreaks since it first appeared in 1976 -- with the worst epidemic occurring in 2014. How does the virus spread, and what exactly does it do to the body? Alex Gendler details what Ebola is and why it's so hard to study.

Highlighting role of animal research in human health.  A visually appealing website with an array of research summaries.

A British researcher has received permission to use a powerful new genome editing technique on human embryos, even though researchers throughout the world are observing a voluntary moratorium on making changes to DNA that could be passed down to subsequent generations.

A new study, published and reviewed in Nature magazine, shows the changes in shades of green (a proxy for plant health) in response to certain environmental factors - in this case, temperature, water availability and cloud cover.

An international group of scientists meeting in Washington called on Thursday for what would, in effect, be a moratorium on making inheritable changes to the human genome. The group said it would be "irresponsible to proceed" until the risks could be better assessed and until there was "broad societal consensus about the appropriateness" of any proposed change. The group also held open the possibility for such work to proceed in the future by saying that as knowledge advances, the issue of making permanent changes to the human genome "should be revisited on a regular basis."

Scientists were investigating a tantalizing but controversial hypothesis: that a man's experiences can alter his sperm, and that those changes in turn may alter his children.

IN recent weeks, two major medical organizations have issued independent warnings about toxic chemicals in products all around us. Unregulated substances, they say, are sometimes linked to breast and prostate cancer, genital deformities, obesity, diabetes and infertility. "Widespread exposure to toxic environmental chemicals threatens healthy human reproduction," the International Federation of Gynecology and Obstetrics warned in a landmark statement last month.

The agricultural revolution was one of the most profound events in human history, leading to the rise of modern civilization. Now, in the first study of its kind, an international team of scientists has found that after agriculture arrived in Europe 8,500 years ago, people's DNA underwent widespread changes, altering their height, digestion, immune system and skin color. Researchers had found indirect clues of some of these alterations by studying the genomes of living Europeans. But the new study, they said, makes it possible to see the changes as they occurred over thousands of years.

Lots of resources for enzymens