Because detectable mass only makes up about 5 percent of the universe - and the universe is expanding faster now than in the past - a rethink of mass and gravity has been required. The umbrella term for this mass that must exist, but can't be detected, is "dark matter." Don't worry if that definition is vague, no one knows any more than that.
Dark matter can be inferred by gravitational effects - and things like antimatter and baryonic clouds can be excluded - and so hundreds of explanations have been created for it. A new one by Mikhail Medvedev, professor of physics and astronomy at the University of Kansas is called "flavor-mixed multicomponent dark matter."
By Helen King, The Open University
It wasn’t that long ago that it was believed that regular periods were essential for women's health and in their absence, a loss of blood through another orifice was a fair substitute.
In a classical Greek text linked to Hippocrates, the Aphorisms, it was written that “a nosebleed is a good thing if the menstrual period is suppressed”. So too was vomiting blood. And these beliefs lasted in western Europe until the middle of the 19th century.
But what was the theory behind what now seems a pretty alarming set of beliefs?1. A build up of blood caused illness -->
Should scientists handle retractions differently?
Peer review cannot catch everything. In many papers, there is no peer review at all, it is editorial review that checks off a few boxes and relies on post-publication peer review to find flaws. That makes retractions more common.
Greenhouse gases, originating from natural sources, industrial processes and the burning of fossil fuels, are the culprits behind current global warming fears. The most abundant among them is carbon dioxide, which made up 84% of the United State's greenhouse gases in 2012, and can linger in Earth's atmosphere for up to a thousand ears.
Countries all over the world are looking to reduce their carbon dioxide footprint but carbon dioxide is essentially a waste product with little immediate commercial value and large treatment costs. New low-cost technologies will be needed to incentivize greenhouse gas capture by industry.
Over the past couple of years, massive open online courses (MOOCs) have taken the academic world by storm. Despite much debate about whether the idea of running free online courses for everyone is both a good and cost-effective idea in the long-run, MOOCs are teaching universities valuable lessons about how students want to learn.-->
Mathematical techniques that not only identify whether two data sets correlate, but also whether one drives the other, have allowed researchers to look at a lot of old data in new ways. Methods have been developed to try to identify and correct for bias in the fossil record but the new research suggests many of these correction methods may actually be misleading.
The new results show that out of all the geological factors, only the area of preserved rock drives biodiversity. Therefore, the other geological factors – counts of fossil collections and geological formations – are not independent measures of bias in the fossil record.
Data from FIRST (MM-020/IFM 07-01), an open-label phase III randomized study of continuous REVLIMID (lenalidomide) in combination with dexamethasone in patients newly diagnosed with multiple myeloma (NDMM) who are not candidates for stem cell transplant, have been published.
The initial findings, including that the trial had met its primary endpoint of progression free survival, were reported during the plenary session at the 55th American Society of Hematology annual meeting in December 2013.
A new supermassive dinosaur species with the most complete skeleton ever found of its type has been unveiled. Dreadnoughtus schrani was 85 feet long and weighed about 65 tons in life, making iy the largest land animal for which a body mass can be accurately calculated.
Its skeleton is exceptionally complete, with over 70 percent of the bones, excluding the head, represented. Because all previously discovered supermassive dinosaurs are known only from relatively fragmentary remains, Dreadnoughtus offers an unprecedented window into the anatomy and biomechanics of the largest animals to ever walk the Earth.
By Tanya Hill, University of Melbourne
Have you ever considered our cosmic address? It’s a fun device I’ve often used to help students get a grasp on our place in the universe.
For example, I work at the Melbourne Planetarium, 2 Booker St, Spotswood, Victoria, Australia, Earth, Solar System, Orion Arm, Milky Way Galaxy, Local Group, Virgo Cluster, Local Supercluster, the Universe.-->
A team of epidemiologists have written a study indicating that exposure to certain phenols during pregnancy, especially parabens and triclosan, may disrupt growth of boys during fetal growth and the first years of life.
Triclosan is on store shelves and in almost every home. Bisphenol A (BPA), which has been increasingly removed from products due to environmental claims, showed no impact.
Two new species of sea-dwelling, mushroom-shaped organisms have been discovered.
Scientists classify organisms based on shared characteristics using a taxonomic rank, including kingdom, phylum, and species. In 1986, the authors of this study collected organisms at 400 and 1000 meters deep on the south-east Australian continental slope and only just recently isolated two types of mushroom-shaped organisms that they couldn't classify into an existing phylum.
A group of ecotoxicologists claim that the US Environmental Protection Agency's evaluations of pesticide safety are inadequate and lead to bias.
Parts of the iconic Galapagos Islands have been overrun by invasive plants from other parts of the world, according to results published in Neobiota which confirm that in the humid highland part of Santa Cruz Island in the Galapagos National Park, nearly half of the canopy of the vegetation is comprised of non-native trees, shrubs and grasses.
Keeping upright in a low-gravity environment is not easy and nothing shows that more than by how often NASA has documented astronauts falling on the lunar surface.
A new paper suggests these moon mishaps might be common because its gravity isn't sufficient to provide astronauts with unambiguous information on which way is "up".
You have a new galactic address; astronomers have determined that our own Milky Way galaxy is part of a newly identified enormous supercluster of galaxies - dubbed "Laniakea," which means "immense heaven" in Hawaiian.
This discovery broadens the boundaries of our galactic neighborhood and establishes previously unrecognized linkages among various galaxy clusters in the local Universe. How big are are talking? The Milky Way galaxy alone has 100 billion stars. We think. And then there are 1012 galaxies. So your address is now a lot bigger. Instead of being Earth, Sol, Orion arm, Milky Way, Local Group and Virgo cluster, you can now add Laniakea before Universe.
Selective Serotonin Reuptake Inhibitors (SSRIs), the most widely used drugs for the treatment of depression, have been reported to reduce bone formation and increase the risk of bone fracture. Since osseointegration is influenced by bone metabolism, a new study investigated the association between SSRIs and the risk of failures in osseointegrated implants.
Within the limits of the study, the findings indicate that treatment with SSRIs is associated with an increased failure risk of osseointegrated implants.
Eric R. Kandel, MD, who shared the 2000 Nobel Prize in Physiology or Medicine for his discoveries related to the molecular basis of memory, and Denise B. Kandel, PhD, professor of psychiatry at Columbia University Medical Center, write in the New England Journal of Medicine that electronic cigarettes (e-cigarettes) may function as a "gateway drug"—a drug that lowers the threshold for addiction to other substances, such as marijuana and cocaine— as part of the 120th Shattuck lecture and presented to the Massachusetts Medical Society.
Most living mammals are nocturnal and it has long been thought that the transition to nocturnality occurred at about the same time as mammals evolved, around 200 million years ago. That hypothesis was based on features such as the large brains of mammals (good for processing information from senses like hearing, touch, and smell) and the details of light-sensitive chemicals in the eyes of mammals.
It turns out that nocturnal activity might have a much older origin among ancient mammal relatives, called synapsids.