Earth’s magnetic field is generated by an interaction between rotation in the planet’s core and electrical currents. The field then creates the magnetosphere, which acts sort of like a force field, protecting the planet from the brunt of the sun's solar wind. This field has both a North and South pole, which can be used for navigational purposes, and they are not static. Variations in the electric current have caused the poles to migrate as much as 16 km (10 miles) per year.
What will it take to convince skeptics of global warming that the phenomenon is real? Surely, many scientists believe, enough droughts, floods and heat waves will begin to change minds.
But a new study led by a Michigan State University scholar throws cold water on that theory.
Only 35 percent of U.S. citizens believe global warming was the main cause of the abnormally high temperatures during the winter of 2012, Aaron M. McCright and colleagues report in a paper published online today in the journal Nature Climate Change.
"Many people already had their minds made up about global warming and this extreme weather was not going to change that," said McCright, associate professor in MSU's Lyman Briggs College and Department of Sociology.
Winter 2012 was the fourth warmest winter in the United States dating back to at least 1895, according to the National Oceanic and Atmospheric Administration. Some 80 percent of U.S. citizens reported winter temperatures in their local area were warmer than usual.
The researchers analyzed March 2012 Gallup Poll data of more than 1,000 people and examined how individuals' responses related to actual temperatures in their home states. Perceptions of warmer winter temperatures seemed to track with observed temperatures.
"Those results are promising because we do hope that people accurately perceive the reality that's around them so they can adapt accordingly to the weather," McCright said.
But when it came to attributing the abnormally warm weather to global warming, respondents largely held fast to their existing beliefs and were not influenced by actual temperatures.
As this study and McCright's past research shows, political party identification plays a significant role in determining global warming beliefs. People who identify as Republican tend to doubt the existence of global warming, while Democrats generally believe in it.
The abnormally warm winter was just one in an ongoing series of severe weather events -- including the 2010 Russian heat wave, Hurricane Sandy in 2012 and the 2013 typhoon in the Philippines -- that many believed would help start convincing global warming skeptics.
"There's been a lot of talk among climate scientists, politicians and journalists that warmer winters like this would change people's minds," McCright said. "That the more people are exposed to climate change, the more they'll be convinced. This study suggests this is not the case."
Most of the genes (around six million) are shared by just 1% of the population, making them quite rare. While there is substantial data today regarding the most common genes, future research will focus on determining the importance and role of these rare genes.
Thanks to this catalogue, the most clinically significant genes can be described, most notably those related to illnesses such as Type 2 diabetes, cirrhosis of the liver, cardiovascular diseases and some cancers. It will also provide a more complete picture of imbalances in the gut microbiome (dysbiosis), particularly those caused by medication.
The holiday season gives people the opportunity to reconnect with friends and family each year. Sometimes these interactions can be stressful, especially around the Thanksgiving table where a heated debate can occur. How come some people are better at handling these stressful interactions than others? A recent study published in the journal Human Communication Research by researchers at Rollins College and The Pennsylvania State University found that individuals who were exposed to intense verbal aggression as children are able to handle intense conflict later in life.
Lindsey Aloia (Rollins College) and Denise Solomon (The Pennsylvania State University) published their findings in the journal Human Communication Research. Aloia and Solomon studied 50 romantically involved couples and found that the more intense the conflict interaction was rated between the couples the stronger the physiological stress response to the conflict. This relationship, however, was weakened for individuals who reported a higher level of childhood exposure to verbal aggression.
For the experiment the couples provided saliva samples to determine their baseline cortisol levels. They were then interviewed separately about the most stressful areas of conflict in their relationship and filled out a questionnaire that asked about their childhood experiences with verbal aggression. Following the interview, partners were asked to sit together and discuss an area of conflict alone for 10 minutes. The sessions were videotaped. After the discussion the couples were separated again and provided two additional saliva samples over a period of 20 minutes after the conflict. Trained judges then watched video recordings of the couples and rated the intensity of the conflict communication of each couple. Finally, cortisol levels were calculated to evaluate experiences of stress using the collected saliva samples.
Previous research has examined the experience of conflict within a multitude of relationships. These studies make it clear that conflict can produce a number of negative outcomes. For example, exposure to conflict has been linked to depression, distress, and anxiety; feelings of hurt and anger; relationship dissatisfaction; and subsequent physical violence. Recent efforts point to the role of physiological processes in understanding the variation in individuals' experiences of interpersonal conflict. Considering the physiological implications for stress and viewing interpersonal conflict interactions as potential stressors highlights how experiences of conflict are shaped by both the demands of the interaction and people's adaptive capacity to handle that stressor.
"Conflict experiences can be beneficial, by alleviating tension and avoiding conflict escalation, reducing communication apprehension, and contributing to closeness within the relationship," said Aloia. "Given the diversity of outcomes associated with interpersonal conflict, efforts to understand variation in the experienced negativity of conflict experiences are extremely important in helping people navigate these interactions."
CELLULAR SNACK PACK: An axon in the optic nerve of a mouse packs mitochondria (pink) into bite-size parcels for degradation by adjacent astrocytes. KEUN-YOUNG KIM, MARK ELLISMAN, NICHOLAS MARSH-ARMSTRONG EDITOR'S CHOICE IN NEUROSCIENCE
The paper C.O. Davis et al., “Transcellular degradation of axonal mitochondria,” PNAS, 111:9633-38, 2014.
The background Most cells clean up their own damaged mitochondria by transporting the organelles into lysosomes, where they are digested internally. Lysosomes are located in the cell body, so neurons with long axons were thought to shuttle far-off axonal mitochondria back to the cell bodies for disposal. Nicholas Marsh-Armstrong of Johns Hopkins University School of Medicine and colleagues observed that in mice, retinal glial cells called astrocytes, clustered around the head of the optic nerve, were constantly chomping up cellular parcels extruded by axons in the nerve, leading Marsh-Armstrong to wonder what the neurons might be exporting for degradation.
The discovery Marsh-Armstrong and his colleagues used 3-D and transmission electron microscopy to identify the organelles being shed as mitochondria. Axonal mitochondria tagged with a fluorescent transgene showed up within adjacent astrocytes and were apparently degraded there.
Polyethylene (PE) has been considered nonbiodegradable for decades. Although the biodegradation of PE by bacterial cultures has been occasionally described, valid evidence of PE biodegradation has remained limited in the literature. We found that waxworms, or Indian mealmoths (the larvae of Plodia interpunctella), were capable of chewing and eating PE films. Two bacterial strains capable of degrading PE were isolated from this worm’s gut, Enterobacter asburiae YT1 and Bacillus sp. YP1. Over a 28-day incubation period of the two strains on PE films, viable biofilms formed, and the PE films’ hydrophobicity decreased. Obvious damage, including pits and cavities (0.3–0.4 μm in depth), was observed on the surfaces of the PE films using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The formation of carbonyl groups was verified using X-ray photoelectron spectroscopy (XPS) and microattenuated total reflectance/Fourier transform infrared (micro-ATR/FTIR) imaging microscope. Suspension cultures of YT1 and YP1 (108 cells/mL) were able to degrade approximately 6.1 ± 0.3% and 10.7 ± 0.2% of the PE films (100 mg), respectively, over a 60-day incubation period. The molecular weights of the residual PE films were lower, and the release of 12 water-soluble daughter products was also detected. The results demonstrated the presence of PE-degrading bacteria in the guts of waxworms and provided promising evidence for the biodegradation of PE in the environment.
The present study shows that oral sex and swallowing sperm is correlated with a diminished occurrence of preeclampsia which fits in the existing idea that a paternal factor is involved in the occurrence of preeclampsia. Because pregnancy has many similarities with transplantation, we hypothesize that induction of allogeneic tolerance to the paternal HLA molecules of the fetus may be crucial.
Since its advent 50 years ago, the pill has helped revolutionize contraception and transform women’s lives. The pill is so popular today that over 100 million women worldwide currently use this method of contraception, and the majority of users report high levels of satisfaction.
Many women, however, experience unpleasant side effects, ranging from mood changes to androgenic effects, such as acne and unwanted hair growth. The latter are caused by the fact that some progestins (the synthetic versions of the hormone progesterone used in oral contraceptives) interact with androgen receptors. The androgens, such as testosterone, are steroid hormones that are responsible for male characteristics. Some progestins have high androgenic activity and therefore increase the chances of androgen-related side effects, but many more modern pills actually exert anti-androgenic effects.
Over the years, many studies have scrutinized these side effects, but the focus of the majority of these studies has been on metabolic and emotional effects. A few studies also looked at effects on cognitive tasks, and some found that the pill is associated with memory changes, enhancing verbal and recognition memory. The possible effects on brain structure and function, however, have been largely ignored, despite the fact that the steroid from which many progestins were derived has been demonstrated to induce changes in the brain.
A few years back, a study aimed to address this gap in our knowledge and discovered that users of oral contraceptives had larger volumes of gray matter (brain tissue consisting of nerve cell bodies) in certain areas of the brain. However, they failed to take into account the androgenic activity (androgenicity) of the progestin or control for age differences.
Building on this work, scientists from the University of Salzberg enrolled 60 women into a new study. 20 of the participants were naturally cycling, i.e. not taking oral contraceptives (OCs), 18 were using OCs containing androgenic progestins, and 22 were taking OCs containing anti-androgenic progestins.
As described in Brain Research, after controlling for age, MRI scans revealed that women using anti-androgenic progestins had significantly larger gray matter volumes in several brain regions when compared with naturally cycling women. These brain areas include the hippocampus, which is involved in learning and memory, and the fusiform face area (FFA), which is thought to be specialized for facial recognition. Furthermore, they found that volume increased with duration of use, i.e. the longer women had been taking the pill, the greater the gray matter volume in these areas. Women taking androgenic progestins, however, had smaller gray matter volumes in certain brain regions when compared with naturally cycling women.
Next, they asked women to participate in a facial recognition test, which revealed that these observed changes were related to task performance. For the task, women were presented with 30 faces, 15 male and 15 female, for 3 seconds, and asked to memorize them. Next, they were shown 60 photos, which included the 30 previous photos and 30 previously unseen photos, and asked to indicate which ones they had seen before.
The researchers found that women taking anti-androgenic progestins performed significantly better than members of the other two groups, and that performance was related to the gray matter volume in the FFA.
Taken together, this study suggests that androgenic and anti-androgenic progestins may exert differential effects on brain structure. However, this study is limited by the fact that a small sample size was used, and the fact that it is not possible to discern which compound in the combined oral contraceptive could be inducing these effects.
Researchers sequence a rare species of parasitic worm pulled from a patient’s cerebrum, where it was causing seizures, headaches, and flashbacks.
By Bob Grant | November 24, 2014
When a 50-year-old man went to a hospital in the United Kingdom complaining of headaches, seizures, altered sense of smell, and memory flashbacks, doctors performed a battery of tests. Tuberculosis? Negative. Syphilis? Negative. Lyme disease? No. HIV? Also negative. His physicians saw an abnormality in his brain using MRI, but a biopsy found no tumor. It would be four years before doctors found out the reason for the man’s symptoms: a tapeworm. Researchers who studied the worm—and sequenced its genome—published their results last week (November 21) in Genome Biology.
Over that four-year span, doctors performed MRIs and tracked the movement of the worm, which is endemic to Asia, around the right and left hemispheres of the man’s brain. And researchers sequenced the centimeter-long worm upon its extraction to find that it had a genome 10 times larger than any other tapeworm sequenced—a fact that may account for Spirometra erinaceieuropaei’s ability to infect numerous hosts. “Humans aren’t the natural host for the worm—they’re usually found in cats, dogs and carnivores—so when it enters a human, it doesn’t migrate to the gut as it usually would,” lead author and Wellcome Trust Sanger Institute biologist Hayley Bennett told New Scientist. “In previous cases, they’ve been found under the skin, in the lungs or in breast lumps—where people have suspected cancer and found a worm instead.”
Microtubules are cylinders made of 13 protein strands and are one of several components of a cell's cytoskeleton. Motor proteins walk along these bundles to deliver cargoes to various parts of a cell and to discard trash. Microtubules also play a part in cell division, movement and signaling.
Cells constantly build, destroy and rebuild these cylinders and reuse the molecular blocks like Legos. "One of the most interesting phenomena associated with microtubules is this dynamic instability," Kolomeisky said. "When you look at them in cells or in vitro, they grow and grow, and suddenly start to shrink without any change in the external conditions. Then suddenly, they start to grow again."
This instability is essential to cellular processes. "If the cell stabilizes, it dies," said Kolomeisky, a professor of chemistry and of chemical and biomolecular engineering at Rice. In fact, he said, the goal of many drugs that target microtubules aim to stabilize growth so a cell stops functioning before it can reproduce. That's important in the fight against cancer, he said.
At the heart of every cell in our body is a cell nucleus, a dense structure that contains our DNA. For a cell to function normally, it needs to surround its nucleus with a protective membrane but this must open enough to let vital molecules in and out, so the membrane is pierced by hundreds of tiny gateways known as nuclear pores.
The research, published today in Nature Nanotechnology, reports on nuclear pores in frog eggs and reveals how these pores can act like a supercharged sieve, filtering molecules by size but also based on chemical properties. Co-lead author Dr Bart Hoogenboom, from the London Centre for Nanotechnology (UCL Mathematics & Physical Sciences), said: "The pores have been known to act like a sieve that could hold back sugar while letting grains of rice fall through at the same time, but it was not clear how they were able to do this."
Bacteria compete for resources in the environment by injecting deadly toxins into their rivals. Researcher have now discovered that many animals steal toxins from bacteria to fight unwanted microbes growing on them. Genes for these toxins have jumped from bacterial to animals. These genes are now permanently incorporated into the genomes of these animals. Deer ticks, which can carry Lyme disease, are one of the many diverse organisms in which toxin gene transfers from bacteria to animal has occurred.
A gene associated with schizophrenia plays a role in brain development and may help to explain the biological process of the disease, according to new Rutgers research. In the study, published in Biological Psychiatry, Bonnie Firestein, professor in the Department of Cell Biology and Neuroscience, says too much protein expressed by the NOS1AP gene, which has been associated with schizophrenia, causes abnormalities in brain structure and faulty connections between nerve cells that prevent them from communicating properly.
Firestein's research indicates that an overabundance of a protein in the NOS1AP gene resulted in the dendrites -- tree-like structures that allow cells to talk to each other and are essential to the functioning of the nervous system -- being stunted in the developing brains of rats.
She and her colleagues found that too much of the NOS1AP protein in brain cells didn't allow them to branch out and kept them deep within the neocortex, the portion of the brain responsible for higher functioning skills, such as spatial reasoning, conscious thought, motor commands, language development and sensory perception.
In the control group of rats in which NOS1AP chemical protein was not overexpressed, the cellular connections developed properly, with cells moving out to the outer layers of the neocortex and enabling the nerve cells to communicate.
"When the brain develops, it sets up a system of the right type of connectivity to make sure that communication can occur," says Firestein. "What we saw here was that the nerve cells didn't move to the correct locations and didn't have dendrites that branch out to make the connections that were needed."
Although scientists can't pinpoint for certain the exact cause of schizophrenia, they have determined that several genes, including NOS1AP, are associated with an increased risk for the disabling brain disorder and believe that when there is an imbalance of the chemical reactions in the brain, development can be disrupted.
Firestein has been working with Rutgers geneticist Linda Brzustowicz, professor and chair of the Department of Genetics, who co-authored the paper and first began investigating the genetic link between NOS1AP and schizophrenia a decade ago.
While about 1 percent of the general population suffers from schizophrenia, the risk increases to about 10 percent in the first degree relatives of an individual with the disease. NOS1AP has been identified as a risk factor in some families with multiple individuals affected with schizophrenia.
Since the prefrontal cortex, the part of the brain that is associated with schizophrenia, matures through adulthood, Firestein says it is possible that drug treatment therapies could be developed to target the disease in adolescents when schizophrenia is thought to develop and when symptoms appear.
"The next step would be to let the disease develop in the laboratory and try to treat the over expression of the protein with an anti-psychotic therapy to see if it works," says Firestein.
A link between breast cancer and salivary gland cancer has been suspected for decades. This study found an association between mutations in two breast cancer genes and salivary gland cancer. The finding must be verified, but should be considered during genetic counseling for people with BRCA1 or BRCA2 mutations – however, it is premature to offer genetic testing for BRCA1 and BRCA2 mutations to individuals with salivary gland cancer unless there is a family history of breast or ovarian cancer. Individuals known to carry mutations in these genes and who have a salivary gland mass should seek evaluation by a physician.
COLUMBUS, Ohio – The risk of developing cancer in a salivary gland might be higher in people with mutations in either of two genes associated with breast and ovarian cancer, according to a new study by researchers at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James).
Although salivary gland cancer is rare, this retrospective study suggests it occurs 17 times more often in people with inherited mutations in genes called BRCA1 and BRCA2, than those in the general population.
“Further study is needed to confirm this preliminary result, but I believe that a BRCA-positive patient with a lump in a salivary gland should have that lesion evaluated as soon as possible,” says co-author Theodoros Teknos, MD, professor and chair of otolaryngology, director of head and neck oncologic surgery, and the David E. Schuller, MD, and Carole H. Schuller Chair in Otolaryngology at the OSUCCC – James.
The findings are published in the journal JAMA Otolaryngology-Head and Neck Surgery.
It is well known that women who inherit mutations in either of the two genes have a higher risk of breast and ovarian cancer than women without the mutation; men with the mutations are at higher risk of breast cancer. The two mutated genes are also linked to prostate, pancreatic and other cancers.
The study’s principal investigator, Rebecca Nagy, MS, a certified genetic counselor and clinical associate professor of human cancer genetics at the OSUCCC – James, recommends that individuals who carry a BRCA mutation need to be made aware of this possible association.
“The finding should be considered during genetic counseling of families with inherited BRCA1 or BRCA2 mutations,” says Nagy, who is also immediate past president of the National Society of Genetic Counselors. “In the future, patients with salivary-gland cancer and their family members might be referred for BRCA testing, or carriers of BRCA mutations might undergo surveillance for salivary gland cancers.”
Cancers of the salivary glands are rare in the United States, with about three cases occurring annually per 100,000 adults in the general population (0.003 percent).
For this study, Nagy, Teknos, first-author and medical student Tim Shen and their colleagues searched a large BRCA-gene-mutation database maintained by the OSUCCC – James Clinical Cancer Genetics Program for salivary gland cancers. Out of 5,754 people with mutations in either the BRCA1 or BRCA2 gene, the researchers identified three cases of salivary gland cancer (0.052 percent).
“I would like physicians and dentists to realize that BRCA mutations carry risks for salivary gland cancer as well as breast cancer, and to remember that salivary glands include not only the paired parotid glands and submandibular glands but also innumerable minor salivary glands in the oral cavity,” Teknos says.
Funding from the Sandy Slomin Foundation supported this research.
Other researchers involved in this study were Amanda Toland and Leigha Senter.
The dinosaurs were killed off some 65 million years ago after a colossal asteroid struck Earth. But what many people probably don’t know is how paleontologists came to that conclusion. "Mass Extinction: Life at the Brink" tells that story.
Scientists get first measurements from historic comet landing
Cindy Seiwert's insight:
The first measurements taken by the Philae lander, which touched down on Comet 67P on 12 November, reveal organic compounds are present on the comet's surface, and also hint at a dense, icy interior.
Philae made history after successfully landing on the comet after a 10-year journey on board the European Space Agency’s Rosetta probe. Unfortunately, the landing didn't go according to plan and Philae touched down in a shadowy hollow without enough sunlight to recharge its batteries. After the landing, scientists had to hurry to gather as much data as possible from Philae’s instruments before it ran out of power and went into hibernation. This happened on 15 November, and teams have now begun to work through the 60 hours’ worth of observations beamed back to Earth.
Most of the 10 instruments Philae was carrying were successfully deployed and managed to take measurements. The cometary sampling and composition system (COSAC) detected organics in the atmosphere at the comet’s surface – although the exact nature of these compounds and what they can tell us about 67P is still being analysed. The multi-purpose sensors for surface and sub-surface science instrument also managed to hammer a probe into the surface, which because of its hardness is thought to consist of water ice covered with a layer of dust.
Unfortunately, despite the drill being activated, the lander’s sampling system didn’t manage to collect a soil sample for COSAC to analyse. However, there are hopes that Philae will be able to power up again in a few months when the comet moves closer to the sun and the lander’s solar panels are illuminated.
Researchers working near a coal mine in India have discovered an ancient relative of horses and rhinos that originated in India 50 million years ago when the subcontinent was still an island—having separated from Madagascar on its final collision course with Asia. The findings, published in Nature Communications this week, fill a major gap in our understanding of the evolution of a major mammal group.