Army ants build living bridges by linking their bodies to span gaps and create shortcuts across rainforests in Central and South America. An international team of researchers has now discovered these bridges can move from their original building point to span large gaps and change position as required.
The bridges stop moving when they become so long that the increasing costs incurred by locking workers into the structure outweigh the benefit that the colony gains from further shortening their trail. Bridges dismantle when the ants in the structure sense the traffic walking over them slows down below a critical threshold.
A new analysis led by the Johns Hopkins Bloomberg School of Public Health suggests that while most U.S. health insurance plans deny benefits to transgender men and women for medical care necessary to transition to the opposite sex, paying for sex reassignment surgery and hormones is actually cost-effective.
How does the price impact your evaluation of a restaurant meal?
Psychologists have long believed that we judge experiences based on their most intense moment (the peak) and the last part of the experience (end). But that can change dramatically depending on how much customers are paying for the experience., according to a new paper which investigated how the price of pizza changed the relationship between a consumer's overall evaluation of the meal and the evaluation of each individual slice of pizza.
An international team of astrophysicists led by a Johns Hopkins University scientist has for the first time witnessed a star being swallowed by a black hole and ejecting a flare of matter moving at nearly the speed of light.
The finding reported Thursday in the journal Science tracks the star -- about the size of our sun -- as it shifts from its customary path, slips into the gravitational pull of a supermassive black hole and is sucked in, said Sjoert van Velzen, a Hubble fellow at Johns Hopkins.
"These events are extremely rare," van Velzen said. "It's the first time we see everything from the stellar destruction followed by the launch of a conical outflow, also called a jet, and we watched it unfold over several months."
Scientists have developed a new method to model heat wave magnitude that takes both the duration and the intensity of the heat wave into account.
The new metric--the Heat Wave Magnitude Index daily (HWMId)--indicates that a little-studied heat wave in Finland in 1972 had the same extent and magnitude of the 2003 European heat wave that is considered the second strongest heat wave since 1950.
The findings are published today, 27th November 2015, in the journal Environmental Research Letters.
New research finds that progesterone supplements in the first trimester of pregnancy do not improve outcomes in women with a history of unexplained recurrent miscarriages.
The study of 826 women with previously unexplained recurrent miscarriage showed that those who received progesterone treatment in early pregnancy were no less likely to miscarry than those who received a placebo. This was true whatever their age, ethnicity, medical history and pregnancy history.
Smoking high potency 'skunk-like' cannabis can damage a crucial part of the brain responsible for communication between the two brain hemispheres, according to a new study.
Researchers have known for some time that long-term cannabis use increases the risk of psychosis and recent evidence suggests that alterations in brain function and structure may be responsible for this greater vulnerability.
Two new studies report dramatic changes in phytoplankton abundance and nature, changes that have important implications for storing excess carbon. Collectively, these studies suggest that certain types of carbon-intensive algae are flourishing and will play increasingly prominent roles as carbon pumps, removing carbon dioxide from the atmosphere. Using the isotopic signature of phytoplankton amino acids embedded in skeletons of deep water soft corals, Kelton McMahon and colleagues determined how plankton dominance changed in the North Pacific over the past millennium. Their analysis reveals that there was a transition from dominance by non-nitrogen-fixing cyanobacteria to that by eukaryotic microalgae.
Cognitive behavioural therapy could help many people with a dental phobia overcome their fear of visiting the dentist and enable them to receive dental treatment without the need to be sedated, according to a new study by King's College London.
Anxiety about visiting the dentist is common and becomes a phobia when it has a marked impact on someone's well-being; people with dental phobias typically avoid going to the dentist and end up experiencing more dental pain, poorer oral health and a detrimental effect on their quality of life. Estimates from the most recent Adult Dental Health Survey in the UK suggest around one in ten people suffers from dental phobia.
A James Cook University scientist says a new study shows more than half of all tree species in the world's most diverse forest -- the Amazon -- may be globally threatened.
Long-time Amazon researcher, Professor William Laurance from JCU, is a co-author of the study, published this week in the journal Science Advances.
It compared data from forest surveys across the Amazon with maps of current and projected deforestation to estimate how many tree species have been lost, and where.
Professor Laurance said the study suggests existing Amazonian parks and reserves, if properly managed, could protect many of the threatened species. But it was not a forgone conclusion.
For a beholder who is an evolutionary biologist, the eye is has long been a fascinating puzzle because of the many parts that must seamlessly work together for the whole to work properly. Biologists have addressed the question of ocular evolution with comparisons between different species, or macroevolutionary studies, and shown how the evolutionary process can be broken down into discrete steps through which a simple light-sensitive cell can evolve into a complex, multicomponent eye through adaptation.
A new study reveals that many European hospitals fail to routinely test people who may be at risk of an HIV-infection. If tests were more widely offered in the healthcare system, fewer HIV-patients would go unnoticed, especially in Northern Europe.
When a patient is admitted to hospital with a disease that could indicate an HIV-infection, they are not always offered an HIV-test. However, if offered a test, almost all patients accept, as revealed in the currently largest study on the subject, which has just now been published in the renowned scientific journal, PlosOne.
Research efforts on the intestine have increased in recent years. Owing to its enormous surface area - comparable to that of a one-bedroom apartment - and the huge number of neurons it contains - comparable to that in the brain - the intestine is sometimes referred to as the abdominal brain. In addition to absorbing nutrients from the foods we eat, it influences our immune status and metabolism.
With the help of sensors, specialized cells in the intestinal wall determine which hormones, if any, should be released into the bloodstream. Overall, it acts as a highly sophisticated control center.
How an organoid grows from cells
CORVALLIS, Ore. - Researchers in the College of Engineering at Oregon State University have discovered a new approach to "vitrification," or ice-free cryopreservation, that could ultimately allow a much wider use of extreme cold to preserve tissues and even organs for later use.
The findings were announced today in PLOS ONE, in work supported by the National Science Foundation.
"This could be an important step toward the preservation of more complex tissues and structures," said Adam Higgins, an associate professor in the OSU School of Chemical, Biological and Environmental Engineering, and expert on medical bioprocessing.
Scientists have mapped out the genes that keep our cells alive, creating a long-awaited foothold for understanding how our genome works and which genes are crucial in disease like cancer.
A team of Toronto researchers, led by Professor Jason Moffat from the University of Toronto's Donnelly Centre, with a contribution from Stephane Angers from the Faculty of Pharmacy, have switched off, one by one, almost 18,000 genes -- 90 per cent of the entire human genome -- to find the genes that are essential for cell survival.
The data, published in Cell on November 25, revealed a "core" set of more than 1,500 essential genes. This lays the foundation for reaching the long-standing goal in biomedical research of pinpointing a role for every single gene in the genome.
Proteins are often referred to as the building blocks of life, and make up about 15 per cent of the mass of the average person, performing a wide variety of essential functions in the body.
Scientists have long speculated about the nature of the dark proteome, the area of proteins that are completely unknown, but a recent study by CSIRO has mapped the boundaries of these dark regions, bringing us one step closer to discovering the complete structure and function of all proteins.
The work, led by Dr Sean O'Donoghue, a data visualisation scientist with CSIRO and the Garvan Institute, has been published today in the prestigious Proceedings of the National Academy of Sciences journal.
Both in materials science and in biomedical research it is important to be able to view minute nanostructures, for example in carbon-fiber materials and bones. A team from the Technical University of Munich (TUM), the University of Lund, Charite hospital in Berlin and the Paul Scherrer Institute (PSI) have now developed a new computed tomography method based on the scattering, rather than on the absorption, of X-rays. The technique makes it possible for the first time to visualize nanostructures in objects measuring just a few millimeters, allowing the researchers to view the precise three-dimensional structure of collagen fibers in a piece of human tooth.
Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that a dim, cool dwarf star is generating a surprisingly powerful magnetic field, one that rivals the most intense magnetic regions of our own Sun.
The star's extraordinary magnetic field is potentially associated with a constant flurry of solar-flare-like eruptions. As with our Sun, these flares would trace tightly wound magnetic field lines that act like cosmic particle accelerators: warping the path of electrons and causing them to emit telltale radio signals that can be detected with ALMA.
Such intense flare activity, the astronomers note, would barrage nearby planets with charged particles.
Many birds travel in flocks, sometimes migrating over thousands of miles. But how do the birds decide who will lead the way? Researchers at Oxford University, reporting in the journal Current Biology, can offer new insight based on studies in homing pigeons. For pigeons, it seems, leadership is largely a question of speed.
'This changes our understanding of how the flocks are structured and why flocks of this species have consistent leadership hierarchies,' says co-author Dr Dora Biro of the Department of Zoology at Oxford.