Group items tagged

Signaling at the neuromuscular junction (NMJ) is a complex process that is required for many actions that sustain life within humans. Toxins that act upon the NMJ, both natural and synthetic, act in a variety of ways to inhibit this function. This case study examines how a variety of toxins can act to disrupt the normal mechanism of function of the NMJ  by placing a protagonist ("Unlucky Chucky") at an eco-spa in Colombia with his good friend Melody. Unfortunately, during their time at the eco-spa, things don't always turn out well for Chucky. A variety of neuromuscular toxins are discussed including curare (d-tubocurarine), Botox (botulinum toxin A), physostigmine and sarin gas (GB). This case was designed to be used in a variety of classrooms ranging from an undergraduate introduction to biology course in a module focused on neuromuscular functioning, to an introduction to physiology course as an introduction to the NMJ; it could also potentially be used in a nursing course that is examining NMJ physiology.

Why is the North American population of monarch butterflies declining? In 1999, a study published in the journal Nature suggested that a variety of genetically modified corn was killing these iconic butterflies. While it was later shown that the conditions in this study did not mirror those in the field, the results garnered a lot of media attention and many people today still believe that monarchs are being killed by GMOs. This case familiarizes students with the plight of the monarchs, encourages them to think about how to test the hypothesis that a toxin is responsible for their decline, and takes a critical look at several studies that investigated the role of Bt corn in the life cycle of monarchs. This interrupted case takes 60-90 min to complete, requires little to no science background, and can be used to explore the ecology and wildlife management of monarchs; risk assessment, toxicity, and exposure; experimental design, the scientific method, hypothesis, and critical thinking; or the relationship between science, the media and the public.

Taylor must write a report about a natural toxin while she is home from college on break. After a family dinner conversation about the latest attempt to poison a politician via a letter, Taylor decides to explore how ricin acts as a poison. Students work in small groups to help Taylor by working through figures from primary literature papers and exploring the use of an in vitro translation system, sucrose gradient fractionation and the effect of inhibiting various steps of translation.  A shorter, second day activity involves students looking further at the effect of ricin upon ribosome function and at the ricin protein itself.  Students individually complete a cumulative assignment of writing a letter back to Mom and Dad about how ricin has its effects. This case was designed for use in a second semester biochemistry course or a molecular biology course that incorporates the mechanism of transcription. Prerequisite knowledge includes a general understanding of the steps of translation and the ability to interpret data from agarose gels.

China is engulfed in an extreme amount of pollution, and it's causing health problems for people living in this area! How can we help fight some of these diseases? Laci explains how broccoli could incredibly helpful when it comes to ridding the body of deadly toxins! Follow DNews on Twitter: http://www.twitter.com/dnews Follow Laci on Twitter: http://www.twitter.com/gogreen18  Read More: China's toxic air pollution resembles nuclear winter, say scientists http://www.theguardian.com/world/2014... "Air pollution now impeding photosynthesis and potentially wreaking havoc on country's food supply, experts warn."

This PowerPoint-driven case study presents three different stories, each of which explores an aspect of membranes. The first (The Exploding Fish) covers diffusion, specifically addressing the question of why animal cells explode in freshwater but fish do not, and differences between saltwater and freshwater fish. The second case (The Pleasurable Poison) is designed to show that alcohol can slip across membranes and also highlights some of the problems of ingesting this toxin. The third case (The Dangerous Diet) explores a weight-loss drug, DNP, and how it operates in mitochondrial membranes. The first of these case studies also includes a number of "clicker" questions. These cases were originally designed for a semester-long, introductory biology course for non-majors, and instructors can choose to use one or all of the cases to suit their course.

When scientists first made contact with an isolated village of Yanomami hunter-gatherers in the remote mountains of the Amazon jungle of Venezuela in 2009, they marveled at the chance to study the health of people who had never been exposed to Western medicine or diets. But much to their surprise, these Yanomami's gut bacteria have already evolved a diverse array of antibiotic-resistance genes, according to a new study, even though these mountain people had never ingested antibiotics or animals raised with drugs. The find suggests that microbes have long evolved the capability to fight toxins, including antibiotics, and that preventing drug resistance may be harder than scientists thought.

In this video Paul Andersen explains how chemicals can cause both chronic and acute diseases. A discussion of the five main types of toxins; neurotoxins, carcinogens, teratogens, endocrine disruptors, and allergens is including. The LD50 method of determining toxicity as well as a discussion of bioaccumulation and biomagnification is is included.

Genetically modified organisms (GMOs) or genetically engineered (GE) foods have the potential to cause a variety of health problems.  For example, they may produce new allergens and toxins, and spread harmful traits to non-GMO crops. In addition, at least one major environmental impact of genetic engineering has already reached critical proportions: overuse of herbicide-tolerant GE crops has spurred an increase in herbicide use and an epidemic of herbicide-resistant "superweeds," which will lead to even more herbicide use. The long-term impacts of GMOs are unknown, and once released into the environment they cannot be recalled.  

Join the Amoeba Sisters as they explore biomagnification! Discover why toxins are especially bad news for high level consumers.

Would you rather be bitten by a venomous rattlesnake or touch a poisonous dart frog? While both of these animals are capable of doing some serious damage to the human body, they deliver their dangerous toxins in different ways. Rose Eveleth sheds light on the distinction between poison and venom (and why you shouldn't treat either one like you've seen in the movies).

Their nervous systems have changed over time to fight off the powerful chemicals-an extraordinary example of evolution in action, according to a new study. "I've been wanting to understand how organisms could acquire neurotoxins, [which] requires an animal to reorganize their nervous system," says study coauthor Rebecca Tarvin, a biologist at the University of Texas at Austin and National Geographic Society grantee.

To address this issue, we have developed case studies that track the evolution of traits from their origination in DNA mutation, to the production of different proteins, to the fixation of alternate macroscopic phenotypes in reproductively isolated populations.

Extensive lessons from hands on inquiry lab at University of Rochester, developed/written with research funds.

A complete understanding of evolution requires knowledge that spans many biological sub-disciplines. However, students are often taught evolution in the context of ecological systems and isolated from genetic and cellular ones. To address this issue, we have developed case studies that track the evolution of traits from their origination in DNA mutation, to the production of different proteins, to the fixation of alternate macroscopic phenotypes in reproductively isolated populations.

This case study was written for an introductory course for biology majors who are first learning about embryonic development. The case is composed of several parts and involves a storyline about a team of researchers who find frogs and eggs in bamboo plants during a field study. Students consider what these observations mean, learn basics about the stages of animal embryonic development, and make connections to phylogeny and natural selection. Students then apply their understanding of animal embryonic stage development to the chemical atrazine in the environment by examining data from several experiments. As a concluding activity students write a letter to an agency or newspaper of their choosing stating their opinion surrounding the use of atrazine in the environment. The case proceeds in a progressive disclosure format and involves a combination of class discussion, small group work, and homework. Because the case focuses on very basic animal embryonic development, it would also be a great start to a developmental biology course or an embryology course.