Hotter is better for removing allergens in laundry
SAN FRANCISCO -- A new study finds that the heat setting you choose when doing laundry makes all the difference when it comes to killing dust mites. The researchers found that washing laundry in hot water--140 degrees Fahrenheit (60 ºC) or higher--kills all house dust mites, compared with just 6.5% of dust mites in laundry washed at 104 degrees Fahrenheit (40 ºC), or warm water. The study is being presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20.
Hotter water temperatures are also more effective in removing dog dander and pollen, says lead researcher Jung-Won Park, M.D., Ph.D., of Yonsei University in Seoul, Korea.
There is an alternative to washing in hot water that’s also effective, Dr. Park found: washing at a lower temperature (between 86-104° F, or 30-40 ºC), then rinsing the laundry twice with cold water for three minutes each.
In the study, researchers compared allergen levels on cotton sheets after they were washed in various temperature settings. They found that since more pollen was left on the sheets when they were washed in cooler temperatures (86° F, or 30ºC), rinsing the sheets was especially important when using this temperature setting.
Green tea may protect the bladder from becoming inflamed
ANAHEIM, Calif – Herbal agents could be used to treat inflammatory bladder diseases, according to a preliminary study that looked at the ability of green tea to protect bladder cells from inflammation. The University of Pittsburgh School of Medicine study, being presented at the annual meeting of the American Urological Association (AUA) in Anaheim, Calif., found that components of green tea protected bladder cells from damage in culture. The study is Abstract 299 in the AUA proceedings.
Green tea, reported to have many health benefits, is rich in powerful antioxidants that make it a possible remedy for many medical conditions. It is comprised of catechins – plant metabolites that provide it with many anti-oxidative properties.
"We discovered that catechins found in green tea protected both normal and cancerous bladder cells from inflammation when we exposed the cells to hydrogen peroxide," said Michael B. Chancellor, M.D., professor of urology and gynecology at the University of Pittsburgh School of Medicine. "Although further studies are needed, these results indicate herbal supplements from green tea could be a treatment option for various bladder conditions that are caused by injury or inflammation."
In the study, normal and cancerous bladder cells were exposed to two major catechin components of green tea, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), for 23 hours. Both significantly protected cell lines from exposure to hydrogen peroxide, which damages or kills cells. The concentrations of EGCG and ECG used in the study were at levels that may be achieved through dietary intake.
Repetitive exposure to an opinion can influence as much as exposure to opinions from several people
Study examines people's tendency to conclude that a familiar opinion is the same as a popular opinion
WASHINGTON -- Whether people are making financial decisions in the stock market or worrying about terrorism, they are likely to be influenced by what others think. And, according to a new study in this month’s Journal of Personality and Social Psychology, published by the American Psychological Association (APA), repeated exposure to one person’s viewpoint can have almost as much influence as exposure to shared opinions from multiple people. This finding shows that hearing an opinion multiple times increases the recipient’s sense of familiarity and in some cases gives a listener a false sense that an opinion is more widespread then it actually is.
In a series of six experiments that included 1044 students, from the University of Michigan, Princeton University, Rutgers University, University of Michigan – Dearborn, University of Toledo and Harvard University, researchers sought to understand individuals’ accuracy in identifying group norms and opinions. The experiments included dividing students into three groups, (three person control group, single opinion group and repeated opinions group).
Participants in the three person control group read three opinion statements each made by a different group member. The participants in the repeated opinion group read the same three statements but they were all attributed to one group member. Those in the single opinion control group read one opinion statement from one group member.
The studies found that an opinion is more likely to be assumed to be the majority opinion when multiple group members express their opinion. However, the study also showed that hearing one person express the same opinion multiple times had nearly the same effect on listener’s perception of the opinion being popular as hearing multiple people state his/her opinion.
Researchers examined the underlying processes that take place when individuals estimate the shared attitude of a group of people and how that estimation of collective opinion can be influenced by repetition from a single source. Since gauging public opinion is such an essential component in guiding our social interactions, this research has implications in almost every facet of modern day life.
"This study conveys an important message about how people construct estimates of group opinion based on subjective experiences of familiarity," states lead author Kimberlee Weaver, (Ph.D), of Virginia Polytechnic Institute and State University. "The repetition effect observed in this research can help us to understand how our own impressions are influenced by what we perceive to be the reality of others. For example, a congressman may get multiple phone calls from a small number of constituents requesting a certain policy be implemented or changed, and from those requests must decide how voters in their state feel about the issue. This study sheds light on the cognitive processes that take place that may influence such a decision."
UCLA imaging study reveals how pure oxygen harms the brain
Adding a little carbon dioxide could prevent lasting damage
It's a scenario straight out of Gray's Anatomy – a paramedic or doctor plops a mask over the face of a person struggling to breathe and begins dispensing pure oxygen.
Yet growing research suggests that inhaling straight oxygen can actually harm the brain. For the first time, a new UCLA brain-imaging study reveals why. Published in the May 22 edition of Public Library of Science (PLoS) Medicine, the findings fly in the face of national guidelines for medical practice and recommend a new approach adding carbon dioxide to the gas mix to preserve brain function in patients.
"For decades, the medical community has championed 100 percent oxygen as the gold standard for resuscitation. But no one has reported what happens inside our brains when we inhale pure oxygen," explained Ronald Harper, distinguished professor of neurobiology at the David Geffen School of Medicine at UCLA. "What we discovered adds to a compelling body of evidence for modifying a widely practiced standard of care in the United States."
Harper's team used functional magnetic resonance imaging (fMRI) to capture detailed pictures of what occurs inside the human brain during two different breathing scenarios. The technique detects subtle increases in blood flow triggered by the activation of different parts of the brain, causing these regions to glow or "light up" on the color scan.
The researchers scanned the brains of 14 healthy children, ages 8 – 15, as they inhaled 100 percent oxygen through a mouthpiece, and monitored their breathing and heart rates. After waiting eight minutes for the youngsters' breathing to return to normal, the team added 5 percent carbon dioxide to the gas mixture and repeated the scan.
A comparison of the two scans revealed dramatic differences.
"When the children inhaled pure oxygen, their breathing quickened, resulting in the rapid exhalation of carbon dioxide from their bodies," said coauthor Paul Macey, associate researcher in neurobiology. "The drop in carbon dioxide narrowed their blood vessels, preventing oxygen from reaching tissue in the brain and heart."
That's when something surprising happened on the MRI scan.
Three brain structures suddenly lit up: the hippocampus, which helps control blood pressure; the cingulate cortex, which regulates pain perception and blood pressure; and the insula, which monitors physical and emotional stress.
All this activity awakened the hypothalamus, which regulates heart rate and hormonal outflow. Activation of the hypothalamus triggered a cascade of harmful reactions and released chemicals that can injure the brain and heart.
"Several brain areas responded to 100 percent oxygen by kicking the hypothalamus into overdrive," explained Harper. "The hypothalamus overreacted by dumping a massive flood of hormones and neurotransmitters into the bloodstream. These chemicals interfere with the heart's ability to pump blood and deliver oxygen – the opposite effect you want when you're trying to resuscitate someone."
When the children inhaled the carbon dioxide-oxygen mix, the hypothalamus' hyperactivity vanished from the MRI scan.
"Adding carbon dioxide to the oxygen relaxed the blood vessels, allowed oxygen to reach the heart and brain, calmed the hypothalamus and slowed the release of dangerous chemicals," said Macey.
"Pure oxygen kindles the match that fuels a forest fire of harm to the body," said Harper. "But a little whiff of carbon dioxide makes it all go away."
Based on their findings, the researchers strongly encourage healthcare providers to add carbon dioxide to oxygen dispensation, especially when resuscitating infants or administering oxygen for more than a few minutes. The new direction could hold particular implications for patients of stroke, heart attack, carbon monoxide poisoning and any long-term oxygen therapy.
"When in doubt about a case, the current medical approach is to increase oxygen levels and wait to see if the patient improves," explained Harper. "But no one has ever scanned patients' brains to examine how they respond to oxygen therapy."
Earlier data on high oxygen's harmful effects have already resulted in policy changes overseas. Instead of using straight oxygen, many European hospitals now resuscitate patients with room air, which contains a mixture of nitrogen, oxygen and carbon dioxide; or with a blend of oxygen and carbon dioxide.
Climate change threatens wild relatives of key crops
At risk are vital genetic resources for resisting drought, pests
ROME, ITALY -- Wild relatives of plants such as the potato and the peanut are at risk of extinction, threatening a valuable source of genes that are necessary to boost the ability of cultivated crops to resist pests and tolerate drought, according to a new study released today by scientists of the Consultative Group on International Agricultural Research (CGIAR). The culprit is climate change, the researchers said.
According to the study, in the next 50 years as many as 61 percent of the 51 wild peanut species analyzed and 12 percent of the 108 wild potato species analyzed could become extinct as the result of climate change. Most of those that remained would be confined to much smaller areas, further eroding their capacity to survive. The study also examined wild relatives of cowpea, a nutritious legume farmed widely in Africa. It found that only two of 48 species might disappear. However, the authors predict that most wild cowpeas will decline in numbers because climatic changes will push them out of many areas they currently inhabit.
"Our results would indicate that the survival of many species of crop wild relatives, not just wild potato, peanuts and cowpea, are likely to be seriously threatened even with the most conservative estimates regarding the magnitude of climate change," said the study’s lead author, Andy Jarvis, who is an agricultural geographer working at two CGIAR-supported centers – the Colombia-based International Center for Tropical Agriculture and Bioversity International, with headquarters in Rome. "There is an urgent need to collect and store the seeds of wild relatives in crop diversity collections before they disappear. At the moment, existing collections are conserving only a fraction of the diversity of wild species that are out there."
Extinction of crop wild relatives threatens food production because they contain genes for traits such as pest resistance and drought tolerance, which plant breeders use to improve the performance of cultivated varieties. The reliance on wild relatives to improve their cultivated cousins on the farm is expected to intensify as climate change makes it too hot, too cold, too wet or too dry for many existing crop varieties to continue producing at their current levels.
The results of the study were announced on International Biodiversity Day, organized by the Convention on Biological Diversity (CBD).
Jarvis and his colleagues looked specifically at the effects of climate change on the three crops in Africa and South America. The scientists focused on the two continents because this allowed them to consider how known populations of wild plants would fare in a wide variety of growing conditions. They found the impact of climate change is likely to be more pronounced in some species than in others but that, in general, all three groups of species would suffer.
Though not apparent to the average consumer, the wild relatives of crops play an important role in food production. All food crops originated from wild plants. But when they were domesticated, their genetic variation was narrowed significantly as farmers carefully selected plants with traits such as those related to taste and appearance as well as to yield. When trouble arises on the farm—attacks by pests or disease or, more recently, stressful growing conditions caused by climate change—breeders tend to dip back into the gene pool of the robust wild relatives in search of traits that will allow the domesticated variety to overcome the threat.
In recent years, genes available in wild relatives have helped breeders develop new types of domesticated potatoes that can fight devastating potato blight and new types of wheat more likely to survive drought conditions. Wild relatives of the peanut have helped breeders provide farmers with varieties that can survive a plant pest known as the root knot nematode, and resist a disease called early leaf spot. In fact, according to the report, more than half of new domesticated peanut varieties developed in the last five years have incorporated traits from wild relatives. Cowpea wild relatives are known to be a reservoir of genes that could confer resistance to major insect pests. In the US alone, the value of the improved yield and quality derived from wild species is estimated to be in the hundreds of millions of dollars a year.
Jarvis said the vulnerability of a wild plant to climate change can depend on its ability to adapt by, for example, extending its range as warming in its native regions becomes too hot to handle. One reason wild peanut plants appear to be so vulnerable to climate change is they are largely found in flat lands and would have to migrate a long way to reach cooler climates, a predicament exacerbated by the fact that peanuts bury their seeds underground, a meter or less from the parent plant. That limits the speed at which seeds can move into more favorable climates. By contrast, plants in mountainous locations could theoretically survive by extending their range slightly up a slope, even by only a few meters, to find cooler weather. What scientists must do, Jarvis said, is identify which wild relatives are most likely to suffer from climate change and give them priority for conservation.
"The irony here is that plant breeders will be relying on wild relatives more than ever as they work to develop domesticated crops that can adapt to changing climate conditions," said Annie Lane, the coordinator of a global project on crop wild relatives led by Bioversity International. "Yet because of climate change, we could end up losing a significant amount of these critical genetic resources at precisely the time they are most needed to maintain agricultural production.
Research that identifies crop wild relatives threatened by climate change is part of a broader CGIAR effort to anticipate and blunt the effects of global warming on agriculture. In the local, national, and international policy arenas, CGIAR researchers are generating innovative options to foster adaptation to climate change. In addition, new research at CGIAR-supported centers focuses on understanding the impacts of shifting climate patterns on natural resources, such as water, fisheries, and forests, and on planning for improved management of these resources to meet the needs of growing populations as the climate changes.
Alarming acceleration in CO2 emissions worldwide
Stanford, CA -- Between 2000 and 2004, worldwide CO2 emissions increased at a rate that is over three times the rate during the 1990s—the rate increased from 1.1 % per year during the 1990s to 3.1% per year in the early 2000s. The research, published in the early on-line edition of the Proceedings of the National Academy of Sciences* May 21-25, also found that the accelerating growth rate is largely due to the increasing energy intensity of economic activity (the energy required to produce a unit of gross domestic product) and the carbon intensity of the energy system (the amount of carbon per unit of energy), coupled with increases in population and in per-capita gross domestic product. “No region is decarbonising its energy supply,” states the study.