Group items tagged

ach of the four hallmarks of autosomal dominant inheritance are fulfilled. Each affected individual has an affected parent; there is no skipping of generations. Males and females are equally likely to be affected. About 1/2 of the offspring of an affected individual are affected (the recurrence risk is 1/2). Normal siblings (II-3) of affected individuals have all normal offspring.

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.

In this video Paul Andersen explains how the climate on the earth is affected by the amount of solar radiation and the greenhouse affect. The addition of anthropogenic greenhouse gases has led to global warming which is impacting humans on the planet. A discussion of the greenhouse effect and greenhouse gases (including water vapor, carbon dioxide, methane, nitrous oxide, and CFCs) is included. Countries have committed to reduce through both the Kyoto Protocol and the Paris Agreement.

The external environment's effects upon genes can influence disease, and some of these effects can be inherited in humans. Studies investigating how environmental factors impact the genetics of an individual's offspring are difficult to design. However, in certain parts of the world in which social systems are highly centralized, environmental information that might have influenced families can be obtained. For example, Swedish scientists recently conducted investigations examining whether nutrition affected the death rate associated with cardiovascular disease and diabetes and whether these effects were passed from parents to their children and grandchildren (Kaati et al., 2002). These researchers estimated how much access individuals had to food by examining records of annual harvests and food prices in Sweden across three generations of families, starting as far back as the 1890s. These researchers found that if a father did not have enough food available to him during a critical period in his development just before puberty, his sons were less likely to die from cardiovascular disease. Remarkably, death related to diabetes increased for children if food was plentiful during this critical period for the paternal grandfather, but it decreased when excess food was available to the father. These findings suggest that diet can cause changes to genes that are passed down though generations by the males in a family, and that these alterations can affect susceptibility to certain diseases. But what are these changes, and how are they remembered? The answers to questions such as these lie in the concept of epigenetics.

3:49 video, Alzheimer's disease is the most common cause of dementia, affecting over 40 million people worldwide. And though it was discovered over a century ago, scientists are still grappling for a cure. Ivan Seah Yu Jun describes how Alzheimer's affects the brain, shedding light on the different stages of this complicated, destructive disease.

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.

This case study synthesizes students' knowledge of the central dogma and cell structure by examining a rare health disorder in order to understand protein targeting and its medical consequences. Students first identify the molecular alteration in affected members of a family with renal Fanconi syndrome as reported in the New England Journal of Medicine (2014). Students then use an online bioinformatics tool to analyze the wildtype and mutant proteins and examine their subcellular localization. Finally, students use this information to explain the symptoms of affected family members. The case is delivered with a PowerPoint presentation that includes a selection of brainstorming prompts and "clicker questions." Students complete a worksheet (included in the teaching notes) before class, making the activity suitable for a flipped classroom. A second worksheet (also included in the teaching notes) is completed during class. The case is written for an introductory biology course for majors, but could also be used as a unit capstone in a non-majors human biology course; the case is also scalable to upper division courses in physiology that specifically explore kidney function.

UCLA researchers now have the first evidence that bacteria ingested in food can affect brain function in humans. In an early proof-of-concept study of healthy women, they found that women who regularly consumed beneficial bacteria known as probiotics through yogurt showed altered brain function, both while in a resting state and in response to an emotion-recognition task.

Stress isn't always a bad thing; it can be handy for a burst of extra energy and focus, like when you're playing a competitive sport or have to speak in public. But when it's continuous, it actually begins to change your brain. Madhumita Murgia shows how chronic stress can affect brain size, its structure, and how it functions, right down to the level of your genes.

This 8-minute video is derived from the 2013 Holiday Lectures on Science. In it, Dr. Charles Sawyers explains the difference between proto-oncogenes, oncogenes, and tumor suppressor genes, and how mutations in these genes drive cancer development. "Cancer genes" can affect several cellular processes that he groups into three categories: cell growth and survival (i.e., genes involved in the cell cycle, cell fate (i.e., genes involved in cell differentiation), and genome maintenance (i.e, genes involved in DNA repair.)

Students begin by watching the online video clip and completing a worksheet. After that assignment, instructors can decide which of the two activities (or both!) to use in class. In Activity 1, students identify the locations on chromosomes of genes involved in cancer, using a set of 139 "Cancer Gene Cards" and associated posters. In Activity 2, students explore the genetic basis of cancer by examining cards that list genetic mutations found in the DNA of actual cancer patients. Small-group work spurs discussion about the genes that are mutated in different types of cancers and the cellular processes that the affected genes control. The Activity 1 and 2 Overview document provides short summaries of the two activities along with key concepts and learning objectives, background information, references and rubrics, and answers to students' questions. Both cancer discovery activities are appropriate for first-year high school biology (honors or regular), AP and IB Biology. Activity 2 is also appropriate for an undergraduate freshman biology class.

Hyper-IgM syndrome is an X-linked genetic disorder more commonly affecting males than females. It is caused by the lack of heavy chain class-switching from IgM to other isotypes. Patients with hyper-IgM syndrome are susceptible to a variety of infections as demonstrated in this medical case study. Students are presented patient information, symptoms and a diagnosis that must be interpreted. The case was written for use with the team-based learning (TBL) format involving groups of 4-5 students per group, but it could also be completed as an individual project. The case is targeted to premedical/allied health advanced students and is appropriate for any immunology course at the undergraduate or graduate level in a biomedical science program, or health-related professional courses such as advanced physiology, pathophysiology, microbiology, or histology and cytology.

Humans construct boundaries -- around our homes, our neighborhoods, and our nations -- to bring order to a chaotic world. But we rarely consider how these boundaries affect other creatures. In this episode of Think Like A Scientist, we meet conservation photographer Krista Schlyer, who has spent the last seven years documenting the environmental effects of the U.S./Mexico border wall, and biologist Jon Beckmann, who studies how man-made barriers influence the movement of wildlife. Schlyer and Beckmann have seen damaging impacts of the border wall firsthand, but they remain optimistic. Humans probably won't stop constructing walls and fences any time soon, but planning our boundaries with wildlife in mind can help prevent these structures from causing environmental harm.

Researchers have long known that women whose families include fraternal twins are more likely to give birth to twins themselves, and they're finally starting to figure out why. After scanning data from nearly 2000 mothers of fraternal twins, scientists from eight countries found two genes that increase a woman's chance of having twins-one that affects hormone levels and another that may alter how ovaries respond to them. The second of these may also have implications for why some women respond better than others to in vitro fertilization.

In this case study students are provided with information for piecing together the story of how forest fragmentation and biodiversity loss can affect the risk of Lyme disease transmission to humans. The case introduces the dilution effect, a widely accepted theory-and one of the most important ideas in disease ecology-which suggests that disease risk for humans decreases as the diversity of species in an area increases. It also explains how landscape fragmentation, one of the most common threats to biodiversity, can influence the risk of Lyme disease for humans. Students interpret and discuss various figures to develop a concept map that connects all the individual results of the story. Students gain an appreciation for the complexity of species interactions in an ecosystem, the effects of forest fragmentation on these interactions and the possible consequences for human health. This activity was developed for an undergraduate introduction to environmental sciences course under the topic of biodiversity and conservation, but would also be suitable for interdisciplinary studies interested in examining the connections between conservation and public health.

DNA acquired from breeding with Neanderthals may explain why people of European descent respond differently to infection than those of African descent, two studies suggest. The findings might also offer insight into why people of African descent are more prone to autoimmune diseases caused by an overactive immune system.

Our hard-wired stress response is designed to gives us the quick burst of heightened alertness and energy needed to perform our best. But stress isn't all good. When activated too long or too often, stress can damage virtually every part of our body. Sharon Horesh Bergquist gives us a look at what goes on inside our body when we are chronically stressed.

She says people became much more willing to talk about their genetic predispositions and seek out testing for conditions like Alzheimer's disease and cystic fibrosis. The number of patients seeking genetic counseling and testing has increased dramatically, according to a 2014 study that looked at how Jolie's announcement affected interest in testing. But the number of genetic counselors, the people who help both doctors and patients make sense of these tests, hasn't expanded enough to keep up with that demand. There are just 4,000 certified genetic counselors in the country today. That's one for every 80,000 Americans.

When ultraviolet sunlight hits our skin, it affects each of us differently. Depending on skin color, it'll take only minutes of exposure to turn one person beetroot-pink, while another requires hours to experience the slightest change. What's to account for that difference, and how did our skin come to take on so many different hues to begin with? Angela Koine Flynn describes the science of skin color.

The study is the first to examine all of the gene networks affected by fructose that result in changes to brain function and metabolism-more than 20,000 genes in total. Although the study was conducted using rats, the researchers report that the majority of the sequenced genes are comparable to those in humans, including more than 200 genes in the hippocampus, a brain area crucial to memory, and 700 in the hypothalamus, the seat of the brain's metabolic control center.