Group items tagged

A newly developed vaccine that researchers hope will prove effective at destroying tumors in cases where all other treatments have failed is currently being trialed in the UK.

As the prevalence of genetically modified organisms (GMOs) continues to rise, there has been an increasing public interest for information concerning the safety of these products. Concerns generally focus on how the GMO may affect the environment or how it may affect the consumer. One specific concern is the possibility for GMOs to negatively affect human health. This could result from differences in nutritional content, allergic response, or undesired side effects such as toxicity, organ damage, or gene transfer.

This interrupted case study addresses several concepts related to climate change and its effect on the American pika. Often called an indicator species for climate change, the pika has a unique set of variables specific to its environment. Factors such as temperature, snowpack, and vegetation can affect the distribution and ultimately the chances of survival. The case was designed for use in a "flipped" classroom in which students prepare in advance outside of class by filling out a worksheet while watching a video. The video, created by the author of the case, provides students with baseline information that they apply in class to come up with key ideas and predictions, followed by analysis of actual data to test the hypotheses they develop. The case study incorporates group discussion, analysis of experimental design, and data evaluation as central activities and can be taught in a single 50 minute class session. The case was designed for use in a large introductory-level class, but is also appropriate for smaller classes.

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."

Men shed more bacteria into their surroundings than women do, studies have shown. Now scientists have found that men and women have different effects on the variety of bacteria inside a home, too. The variation comes down to skin biology and "perhaps to body size and hygiene practices," note researchers who sequenced the genes in dust that had settled on the tops of doors in 1,200 homes across the U.S. Dogs apparently alter indoor bacteria more extensively than humans or cats. The bacterial signatures of each of these living beings are unique enough that by simply testing dust in a home, investigators can accurately predict if more women or men live there and if dogs or cats do as well.

And as the El Nino weather system has been storming across the Pacific this season, it has stirred up ocean waters enough to cool down the original Blob off of Alaska, but at the same time helped give birth to what has been nicknamed the "Son of Blob" off the coast of Southern California. The still-warmer Alaskan waters, and Son of Blob sector are expected to continue to magnify the El Nino effect for months to come, according to Weather Underground's "Blob Watch" blog.

The researchers, Eicke Latz at the University of Bonn and colleagues, followed up on the parents' hypothesis and found that in mice, cyclodextrin indeed blocked plaque formation, melted away plaques that had already formed in arteries, reduced atherosclerosis-associated inflammation, and revved up cholesterol metabolism-even in rodents fed cholesterol-rich diets. In petri dish-based tests, the researchers found that the drug seemed to have the same effects on human cells and plaques.

She wanted to understand the effects of mutations that the gene for p53 is prone to. In dozens of simulations, she and her colleagues tracked how common p53 mutations further destabilize the already floppy protein, distorting it and preventing it from binding to DNA. Some simulations also revealed something else: a fingerhold for a potential drug. Once in a while, a small cleft forms in the mutated protein's core. When Amaro added virtual drug molecules into her models, the compounds lodged in that cleft, stabilizing p53 just enough to allow it to resume its normal functions.

This flipped case study is formatted as a PowerPoint presentation that uses group experimentation to encourage active learning in a large science classroom. There are options for using either wet bench experimentation or an online simulation, depending on the class goals. Students learn about plant transpiration and how it affects normal plant processes (photosynthesis). The basics of transpiration are covered in an animated video viewed outside of class. The experiment and/or simulation of transpiration can be conducted in or out of class. If the class is very large, the instructor may choose to assign the experiment/simulation for outside of class (post-video) and have the students bring their data to class, or the instructor may choose to just present the students with a data set from which they can work with their groups in class. At the end, students should be able to define transpiration, explain climate effects on transpiration rates, and how transpiration rates affect the overall physiology of the plant itself, through their own hypothesis design and experimentation.

Discover what happens when random events meet allele frequencies: genetic drift! This Amoeba Sisters video also discusses the bottleneck and founder effect as well as contrasts genetic drift with natural selection.

This flipped case study is suited for general education undergraduate level biology. Students prepare ahead of time for class by viewing a video created by the authors that reviews the basics of nutrition and digestion; in class, students then engage in three activities to further explore aspects of the video's content using specific and concrete examples of diverse foods. During the first part of the case study, students learn information about balanced diets, nutrition and the digestive system. Students apply their knowledge on how food passes through the digestive tract, and how absorption and breakdown of nutrients occur by explaining and presenting the process based on assigned food items. Students are then asked to further apply their knowledge when presented with two scenarios ("mini-cases"), one involving gastric bypass surgery and the other the effects of cholera.

In this case study, the complexity of the Malaysian palm oil industry is examined through the perspective of various stakeholders, namely, villagers, corporations, orangutans, smallholders, conservationists, and an average consumer. Students learn about the plight of the orangutan and the environmental impacts of the palm oil industry but also understand the influence of global markets and the effect of their own purchases. Students are challenged to make ethical decisions, propose policy recommendations, and examine their own contributions to the demand for palm oil. The aim of the case is to provide students with tools to personally champion change. The case is appropriate for undergraduate students in wildlife, ecology, biology, or related classes but can also be tailored for advanced high school science courses.

This directed case study follows the story of "Pauline," a 20-year-old college student who has just received results from a personal genetic testing kit she purchased online. The report shows a negative result for variants of the BRCA 1 and 2 genes, which are associated with a greater risk for breast cancer. Although Pauline has a family history of breast cancer, she concludes that she no longer needs to be concerned, or does she? As students work through the questions in this case study, they review the role of genes and how they code for proteins as well as the effects of proteins on health, especially on cellular growth regulation and cancer. They also learn about the process of genetic testing and consider the ramifications of positive and negative tests for diseases or health conditions, especially with respect to breast cancer. The case is designed for non-science majors in a scientific methods course and could also be used in an introductory biology course. The questions in the case could be adapted for an upper level genetics class.

This case study presents the mock trial of "Martin Miller." There is no question that Martin killed his girlfriend; he admitted to stabbing her in a violent rage. But what is the degree of his responsibility? By virtue of Martin having the MAOA-L gene variant, together with a history of childhood abuse, should his punishment be reduced? This hypothetical case, which requires students to think through the issues rather than simply look up a verdict, is based on actual events and violent behaviors that resulted in criminal charges claimed to be related to MAOA. The MAOA gene and its effect on behavior have been extensively studied, and research results have been introduced as evidence in court cases with differing results. The present case study allows students to explore how behavioral genetic information can be applied to a courtroom situation, and requires them to integrate information from biology, ethics, and the law. Note: Due to the unusual structure of the case, no answer key is available.

Scientists have created an "artificial womb" in the hopes of someday using the device to save babies born extremely prematurely. So far the device has only been tested on fetal lambs. A study published Tuesday involving eight animals found the device appears effective at enabling very premature fetuses to develop normally for about a month.

In the study, published Monday (May 1) in Nature Biotechnology,  Luo and colleagues set their sights on two fusions genes they had previously found to be associated with prostate cancer and various forms of rapid and invasive cancer, including liver tumors. Using a modified CRISPR-Cas9 tool that creates a single- rather than double-stranded break in DNA, they targeted the chromosomal breakpoints that form these fusion genes and replaced fusion DNA with a gene encoding the enzyme HSV1-tk. This enzyme effectively kills tumor cells by converting the drug ganciclovir into its active form, which then blocks DNA synthesis and leads to cell death. (Ganciclovir is used to treat cytomegalovirus in humans.)

In this interrupted case study developed for use in a flipped classroom, students read about a picnic that takes place in autumn during the peak of fall color and along the way learn about light absorption by photosynthetic pigments, why leaves turn color in the fall, atmospheric CO2 concentrations and their effect on photosynthesis, and the C3, C4, and CAM photosynthetic pathways. The case is designed to provide introductory biology students with a basic understanding of photosynthetic pathways and how environmental factors affect plants using these pathways. The activity could also be used in an advanced high school biology course covering photosynthesis. The case includes several short videos that students watch as homework before coming to class so that they are prepared to work together in class in small groups to answer the case questions.

A genetic "crystal ball" can predict whether certain people will respond effectively to the flu vaccine. Nine genes are associated with a strong immune response to the flu vaccine in those aged 35 and under, a new study finds. If these genes were highly active before vaccination, an individual would generate a high level of antibodies after vaccination, no matter the flu strain in the vaccine, researchers report online August 25 in Science Immunology. This response can help a person avoid getting the flu.

This case study describes a visit by "Naomi" to her physician, who upon seeing Naomi's bloodwork decides to prescribe her a cholesterol-lowering agent, a statin. The case discusses (1) the prevalence of non-communicable diseases such as atherosclerosis, which can lead to strokes and heart disease; (2) circulating lipoprotein particles including LDL and HDL, differentiating between which is a risk factor for heart disease and which is protective;  (3) the pathway for cholesterol synthesis; (4) the evidence demonstrating that statins inhibit the enzyme HMG-CoA reductase, which is the committed step for cholesterol synthesis; and (5) the kinetic mechanism by which statins inhibit the enzyme. Students examine and interpret data from radioactive tracer and enzyme kinetics studies. The case ends with another visit by Naomi to her physician, who reexamines her bloodwork after she has been taking a statin for six months. Students are asked to determine whether the drug was effective for Naomi and, if not, what changes could be made to her regimen. The case was originally written for use in a survey of biochemistry course for upper level undergraduates.

When it comes to what you bite, chew and swallow, your choices have a direct and long-lasting effect on the most powerful organ in your body: your brain. So which foods cause you to feel so tired after lunch? Or so restless at night? Mia Nacamulli takes you into the brain to find out.