One in eight Americans will fall prey to Alzheimer's disease at some point in their life, current statistics say. Because Alzheimer's is associated with vascular damage in the brain, many of them will succumb through a painful and potentially fatal stroke.

If Dr. Doolittle is famous for talking to animals, then here's a story that might make him hold his tongue: According to new research published online in The FASEB Journal (http://www.fasebj.org), scientists have successfully fused human stem cells derived from subcutaneous adipose (fat) tissue with muscle cells from rat hearts. Not only did these cells "talk" to form new muscle cells altogether, but they actually beat.

A change in the formulation of tenofovir gel, an anti-HIV gel developed for vaginal use, may make it safer to use in the rectum, suggests research presented today at the 18th Conference on Retroviruses and Opportunistic Infections (CROI). In laboratory tests of rectal tissue, researchers from the Microbicide Trials Network (MTN) found the reformulated gel was less harmful to the lining of the rectum than the original vaginal formulation, and just as effective in protecting cells against HIV.

In the mating game, some female mites are mightier than their mates, new research at the University of Michigan and the Russian Academy of Sciences suggests. The evidence comes, in part, from 40 million-year-old mating mites preserved in Baltic amber.

Scientists have published results that will forever change the way researchers view the interplay between gene expression, DNA replication and the prevention of DNA damage.

Scientists at Harvard University are moving closer to answering some age-old questions.

A new finding from scientists at the National Institutes of Health could help efforts to design vaccines and other prevention tools to block HIV in the early stages of sexual transmission, before infection takes hold. Researchers at the NIH National Institute of Allergy and Infectious Diseases have helped explain genetic differences that can distinguish some early-transmitting HIVs—viruses found in an infected individual within the first month after infection—from forms of HIV isolated later in infection. These genetic features help HIV bind tightly to a molecule called integrin α4β7. According to the scientists, the capacity to bind tightly to α4β7 likely enhances the ability of certain HIV viruses to complete the many steps of sexual transmission and become the "founder" virus that establishes infection in an individual.

The Svalbard Global Seed Vault (SGSV) celebrated its third anniversary today with the arrival of seeds for rare lima beans, blight-resistant cantaloupe, and progenitors of antioxidant-rich red tomatoes from Peru and the Galapagos Islands. The arrival of these collections, including many drought- and flood-resistant varieties, comes at a time when natural and man-made risks to agriculture have reinforced the critical need to secure all the world's food crop varieties.

A new dinosaur named Brontomerus mcintoshi, or "thunder-thighs" after its enormously powerful thigh muscles, has been discovered in Utah, USA. The new species is described in a paper recently published in the journal Acta Palaeontologica Polonica by an international team of scientists from the U.K. and the U.S.

Almost 600 million years ago, before the rapid evolution of life forms known as the Cambrian explosion, a community of seaweeds and worm-like animals lived in a quiet deep-water niche near what is now Lantian, a small village in south China.

Immunology: Three percent of the world's population is currently infected by hepatitis C. The virus hides in the liver and can cause cirrhosis and liver cancer, and it's the most frequent cause of liver transplants in Denmark. Since the virus mutates strongly, we have no traditional vaccine, but researchers at the University of Copenhagen are now the first to succeed in developing a vaccine, which provides future hope for medical protection from this type of hepatitis.

Vaccine scientists say their “Holy Grail” is to stimulate immunity that lasts for a lifetime. Live viral vaccines such as the smallpox or yellow fever vaccines provide immune protection that lasts several decades, but despite their success, scientists have remained in the dark as to how they induce such long lasting immunity.

T-cell receptor diversity in blood samples from healthy individuals has been extensively cataloged for the first time in a study published online today in Genome Research (www.genome.org), setting the stage for a better understanding of infectious disease, cancer, and immune system disorders.

A strategy developed by Massachusetts General Hospital (MGH) researchers to shield the ovaries of female mammals from the damaging effects of radiation and chemotherapy has passed an important milestone. A collaborative study with investigators from Oregon Health and Sciences University (OHSU), published online in the journal Fertility and Sterility, reports that brief preexposure of the ovaries to an FDA-approved agent called FTY720 preserved the fertility of female rhesus monkeys exposed to potentially lethal doses of radiation. All of the treated animals have had successful pregancies and delivered healthy offspring.

The ferocious Tyrannosaurus rex has been depicted as the top dog of the Cretaceous, ruthlessly stalking herds of duck-billed dinosaurs and claiming the role of apex predator, much as the lion reigns supreme in the African veld.

A report issued today, co-authored by the Wildlife Conservation Society (WCS) working in conjunction with the Turtle Conservation Coalition, lists the 25 most endangered turtle species from around the world – some of which currently number less than five individuals.

In an advance that could improve battlefield and trauma care, scientists at Albert Einstein College of Medicine of Yeshiva University have used tiny particles called nanoparticles to improve survival after life-threatening blood loss. Nanoparticles containing nitric oxide (NO) were infused into the bloodstream of hamsters, where they helped maintain blood circulation and protect vital organs. The research was reported in the February 21 online edition of the journal Resuscitation.

It's a discordant note in the symphony of good news that usually accompanies stem cell research announcements. Stem cells hold enormous promise in regenerative medicine, thanks to their ability to regenerate diseased or damaged tissues. They have made it possible to markedly improve the effectiveness of many medical treatments – muscle regeneration in cases of dystrophy, skin grafts for treating burn victims, and the treatment of leukemia via bone marrow transplants.

Algae play key roles in the global carbon cycle, helping sequester significant amounts of carbon. Some algal species can bloom, or become so numerous, that they discolor coastal waters and reduce the amount of light and oxygen available in the ecosystem. Previously known as "red tide," the term "harmful algal blooms" (HABs) was introduced two decades ago to note accumulation of algal biomass can sometimes also turn the ocean waters brown or green and disrupt an ecosystem, or that red-colored waters can sometimes be harmless.

Researchers studying the origin of Earth's first breathable atmosphere have zeroed in on the major role played by some very unassuming creatures: plankton.

Researchers from the Georgia Institute of Technology have created a new sampling device that could prevent thousands of people worldwide from dying of pneumonia each year.

Sonja Kotz leads the Minerva research group "Neurocognition of Rhythm in Communication" at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig. She will present evidence from neuroimaging on the impact of cognitive functions on bilingual processing at the AAAS symposium "Crossing Borders in Language Science: What Bilinguals Tell Us About Mind and Brain".

Most patients who undergo total knee replacement (TKR) are age 60 to 80. More than 90 percent of these individuals experience a dramatic reduction in knee pain and a significant improvement in the ability to perform common activities. However questions have been raised about the decline in physical function over the long term despite the absence of implant-related problems. New research revealed today at the 2011 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) evaluates patient functionality 20 years after knee replacement.

Researchers at Columbia University Medical Center have discovered that the skeleton acts as a regulator of fertility in male mice through a hormone released by bone, known as osteocalcin.

Forest biomass could replace as much as one quarter of the liquid fossil fuel now being used for industrial and commercial heating in the Northeastern United States. That's according to a new report released today by the Cary Institute of Ecosystem Studies.

A unique strategy developed by researchers at Cardiff University is opening up new possibilities for improving medical imaging.

Researchers at the University of California, San Diego School of Medicine have identified the motors that move non-infectious prion proteins (PrPC) – found within many mammalian cells – up and down long, neuronal transport pathways. Identifying normal movement mechanisms of PrPC may help researchers understand the spread of infectious prions within and between neurons to reach the brain, and aid in development of therapies to halt the transport.

Tomatoes spend so much time on shelves and in refrigerators that an estimated 20 percent are lost to spoilage, according to the U.S. Department of Agriculture (USDA). But scientists with USDA's Agricultural Research Service (ARS) are working with colleagues at Purdue University to extend the shelf life of tomatoes. The research also may lead to tomatoes that taste better and are more nutritious.

Whole genome sequencing — spelling out a person's entire DNA genetic code — has moved one step closer to being a medical option for direct patient care.

When doctors discover high concentrations of regulatory T cells in the tumors of breast cancer patients, the prognosis is often grim, though why exactly has long been unclear.

The more humanity acidifies and warms the world's oceans with carbon emissions, the harder we will have to work to save our coral reefs.

Scientists have discovered a molecular assistant called Spy that helps bacteria excel at producing proteins for medical and industrial purposes.

In an unprecedented coming-out party, 100 newly discovered species are revealed to the world in a single scholarly paper coordinated by Field Museum scientists.

According to Dr Annette Baudisch of the Max Planck Institute for Demographic Research in Rostock, Germany, current methods of comparing patterns of ageing are limited because they confound two different elements of ageing – pace and shape.

Two artificial big toes – one found attached to the foot of an ancient Egyptian mummy – may have been the world's earliest functional prosthetic body parts, says the scientist who tested replicas on volunteers.

If a human cell and a bacterial cell met at a speed-dating event, they would never be expected to exchange phone numbers, much less genetic material. In more scientific terms, a direct transfer of DNA has never been recorded from humans to bacteria.

The application of a naturally occurring pheromone to honey bee test colonies increases colony growth resulting in stronger hives overall, according to a new study conducted by scientists at Oregon State University and Texas A&M University.

Brain and spinal cord comprise more than just nerve cells. The extracellular matrix, a complex scaffold of proteins with sugar residues, surrounds the cells and influences their well-being. Prof. Wiese's team is interested in the interaction of the matrix with a specific kind of nerve cells, which transmit signals from the brain to muscles (motoneurons). Because injured motoneurons lead to paralysis, clinicians have great interest in being able to influence the growth of these cells. "If we had a medication that could change the extracellular matrix so that it favours the growth and survival of nerve cells, that would be a large step in the treatment of nerve injuries after accidents or also for the treatment of diseases such as Multiple Sclerosis", says Prof. Wiese.

In 1980 in the United States, approximately 4.5% of all pregnant women were of advanced maternal age. By 2007 that figure had increased to 14%. Women over 35 are at increased risk of giving birth to babies with trisomy 21. In a study published online today in the American Journal of Obstetrics & Gynecology (AJOG), researchers from the Sequenom Center for Molecular Medicine confirmed that DNA sequencing of maternal blood plasma could accurately detect trisomy 21.

If you thought that we know everything about how the flea jumps, think again. In 1967, Henry Bennet-Clark discovered that fleas store the energy needed to catapult themselves into the air in an elastic pad made of resilin. However, in the intervening years debate raged about exactly how fleas harness this explosive energy. Bennet-Clark and Miriam Rothschild came up with competing hypotheses, but neither had access to the high speed recording equipment that could resolve the problem. Turn the clock forward to Malcolm Burrows' Cambridge lab in 2010. 'We were always very puzzled by this debate because we'd read the papers and both Henry and Miriam put a lot of evidence for their hypotheses in place and their data were consistent with each other but we couldn't understand why the debate hadn't been settled,' says Burrows' postdoc, Gregory Sutton. He adds, 'We had a serendipitous set of hedgehog fleas show up so we figured we'd take a crack at it and try to answer the question'. Filming leaping fleas with a high-speed camera, Sutton and Burrows found that fleas push off with their toes (tarsus) and publish their discovery in The Journal of Experimental Biology at http://jeb.biologists.org/cgi/content/abstract/214/5/836.