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Movement of ions in and out of cells is crucial to maintaining homeostasis within the body and ensuring that biological functions run properly. The natural movement of molecules due to collisions is called diffusion. Several factors affect diffusion rate: concentration, surface area, and molecular pumps. This activity demonstrates diffusion, osmosis, and active transport through 12 interactive models. Start by following the path of a molecule of dye in water, create concentration gradients on either side of a cell membrane and watch the movement of substances in and out of a cell, and monitor the movement of oxygen into red blood cells with and without hemoglobin.

Awesome interactive player

In this interrupted case study, students meet a pair of fictional newlyweds on their way to Australia for their honeymoon. Initially eager to enjoy the sun, sand, and sights, Tanya and Julien Brahim end up more intimately acquainted with the local wildlife than they had planned. Tanya is bitten by a venomous arachnid and Julien has a run-in with a dangerous cnidarian. This case study was created to help students solidify their knowledge about cardiac myocytes, particularly ion movements associated with action potential generation in autorhythmic and contractile cells. As students work through the case, they will complete fill-in-the-blank paragraphs describing the heart, diagram membrane potentials and ion movements, and compare and contrast action potentials from different cell types. Written for a course in human physiology, the case requires some prior knowledge of membrane potentials, equilibrium potentials, ion gradients, neuronal action potentials, and skeletal muscle action potentials. An optional pre-case assignment (included in the teaching notes) can be used to make sure that students are familiar with the necessary concepts.

" A brief visual task can predict IQ, according to a new study. This surprisingly simple exercise measures the brain's unconscious ability to filter out visual movement. The study shows that individuals whose brains are better at automatically suppressing background motion perform better on standard measures of intelligence. The test is the first purely sensory assessment to be strongly correlated with IQ and may provide a non-verbal and culturally unbiased tool for scientists seeking to understand neural processes associated with general intelligence."

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.

The fates of ice age human groups in Europe were closely linked to climate change, according to an unprecedented study of the genomes of 51 individuals who lived between 45,000 years ago (when modern humans arrived in Europe) and 7,000 years ago. "We see multiple, huge movements of people displacing previous ones," David Reich of the Harvard Medical School said. "During this first four-fifths of modern human history in Europe, history is just as complicated as it is during the last fifth that we know so much more about." 

start at 4:00 human genome project translation target rare diseases with gene therapy: 1)Leber's congenital amaurosis- blindness 2) congenitaal AADC deficiency- enzyme responsible for movement 3)  Muscular Dystrophy- Pompe Disease

How are the stages of mitosis related to the creation of identical daughter cells? The primary function of the stages of mitosis is to make certain that each daughter cell is genetically identical to the mother cell. The mother cell's DNA is copied during interphase. During mitosis the chromosomes condense from long strands to highly coiled structures. The two copies of each DNA strand, called sister chromatids, are physically attached to one another. The chromosomes are moved to the center of the cell and split apart in a highly coordinated fashion. The condensation of the chromosomes, the physical connection of the sister chromatids, and the precise movement of the chromosomes are all important in making sure that each daughter cell has one copy of each chromosome and is genetically identical to the mother cell.

3:16 video To track commercial fishing activity around the world, SkyTruth, a small nonprofit based in Shepherdstown, West Virginia, has recently launched Global Fishing Watch in partnership with Google and Oceana. This prototype tool analyzes a satellite-collected feed of tracking data from ships' automatic identification systems-which vessels use to communicate their location to one another-to map movement over time and automatically determine which ships are engaged in fishing activity. Each vessel is pinpointed on a map outlining fishing laws around the globe. This map will be publicly available on theWeb, allowing anyone with an Internet connection to act as a watchdog and see when and where commercial fishing activity is occurring.

The chart below gives some examples of how disease levels have declined since vaccinations began. Since the introduction of the measles, or MMR vaccine, annual cases of the illness have dropped by a jaw-dropping 99%.

When you leave the house, does your dog or cat even remember you? Read More: A Rat's Tenacious Memory http://www.indiana.edu/~rcapub/v17n1/... "In the wild, rats scramble over the network of pathways they have created, combing their surroundings for food, water, mates, and shelter. Their movements may seem automatic to the untrained eye, simply a reflexive pattern. Decades ago, however, researchers established that rats know where they are going and remember where they have been."

Since the day you were born, a slimy, three-pound blob has controlled your every thought, memory, movement, and emotion. Visual perception, creativity, lying, and persuasion are just a few of the mental skills explored in the new television series Brain Games from the National Geographic Channel.

Single cell moving toward a micropipette containing the chemoattractant cAMP. Note that the cell changes direction in response to movement of the micropipette by extending a new pseudopod in the direction of the pipette tip.

Computed tomography (CT) is an excellent noninvasive technique to investigate bones and soft tissue structures in a patient. Unfortunately, sometimes imaging can be difficult, as any movement from the patient can result in images that are unclear and need to be redone. This is especially difficult when dealing with patients who are young children, mentally impaired, suffering from motor disease, or are in pain. To ensure these images are clear, these challenging patients may require sedation, which is not desirable. General Electronics sought to facilitate treatment of these patients and improve the imaging process in general with the development of the Revolution CT.

 For my research project with the USHMM, I focused on the ethical and moral deficiencies exhibited and practiced by scientists, doctors, nurses, and anthropologists during the Holocaust. As part of that research, I also focused on the American Eugenics movement,and specifically what happened in North Carolina.       The website contains videos, testimonies, articles, timelines, and specific activities associated with the specific Nazi plans of euthanasia through extermination. There is also a site that deals specifically with American and NC eugenics.

Honey bee dancing, perhaps the most intriguing aspect of their biology, is also one of the most fascinating behaviors in animal life. Performed by a worker bee that has returned to the honey comb with pollen or nectar, the dances, in essence, constitute a language that "tells" other workers where the food is. By signaling both distance and direction with particular movements, the worker bee uses the dance language to recruit and direct other workers in gathering pollen and nectar.

The dewlaps of Anolis lizards provide a classic example of a complex signaling system whose function and evolution is poorly understood. Dewlaps are flaps of skin beneath the chin that are extended and combined with head and body movements for visual signals and displays. They exhibit extensive morphological variation and are one of two cladistic features uniting anoles, yet little is known regarding their function and evolution.

"This modular case study tells the story of Dan and Annie, a married couple of Acadian ancestry who have a genetic form of deafblindness called Usher syndrome. They live in Southwest Louisiana, home of the largest population of DeafBlind citizens in the United States. Acadian Usher syndrome is caused by an allele of the USH1C gene that came to Louisiana with the first Acadian settlers from Canada who founded today's Cajun population. This allele's single nucleotide substitution creates an erroneous splice site that produces a defective cytoskeletal protein (harmonin) of the cochlear and vestibular hair cells and retinal photoreceptors. This splice site is the target of a promising gene therapy. The case study applies and connects Mendelian inheritance, chromosomes, cell division, vision and hearing, DNA sequences, gene expression, gene therapy and population genetics to a specific gene and its movement through generations of Dan and Annie's families.  After the introduction, each of the remaining sections can be used independently either for in-class team activities or out-of-class extensions or assignments over an entire year of introductory undergraduate biology. "

Currently there is considerable confusion surrounding the use of the term "organic" as applied to food and other consumer products, but within the agriculture industry the term has a well-defined meaning related to the practices that are allowed in the production of a crop. This case study was written to inform students about organic agriculture and its implications with regard to food nutritional value as well as its costs.  The case is presented as a dilemma in the context of buying produce in the grocery store. Concepts presented include the difference between organic and conventional agricultural practices, the analysis of food to quantify nutrient levels, the history of the organic movement, and the economic and environmental impacts of organic agriculture. The activity was designed for use in a lower level general science course (with a cursory review of the scientific literature) or in an upper level chemistry course (with a thorough analysis of the literature).

A soft brush that feels like prickly thorns. A vibrating tuning fork that produces no vibration. Not being able to tell which direction body joints are moving without looking at them. Those are some of the bizarre sensations reported by a 9-year-old girl and 19-year-old woman in a new study. The duo, researchers say, shares an extremely rare genetic mutation that may shed light on a so-called "sixth sense" in humans: proprioception, or the body's awareness of where it is in space. The new work may even explain why some of us are klutzier than others.