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This study reevaluates how far airborne pathogens in coughs and sneezes can travel. From MIT News:

In the cloud: How coughs and sneezes float farther than you think

The next time you feel a sneeze coming on, raise your elbow to cover up that multiphase turbulent buoyant cloud you’re about to expel. That’s right: A novel study by MIT researchers shows that coughs and sneezes have associated gas clouds that keep their potentially infectious droplets aloft over much greater distances than previously realized.

“When you cough or sneeze, you see the droplets, or feel them if someone sneezes on you,” says John Bush, a professor of applied mathematics at MIT, and co-author of a new paper on the subject. “But you don’t see the cloud, the invisible gas phase. The influence of this gas cloud is to extend the range of the individual droplets, particularly the small ones.”

Indeed, the study finds, the smaller droplets that emerge in a cough or sneeze may travel five to 200 times further than they would if those droplets simply moved as groups of unconnected particles — which is what previous estimates had assumed. The tendency of these droplets to stay airborne, resuspended by gas clouds, means that ventilation systems may be more prone to transmitting potentially infectious particles than had been suspected.

With this in mind, architects and engineers may want to re-examine the design of workplaces and hospitals, or air circulation on airplanes, to reduce the chances of airborne pathogens being transmitted among people.

“You can have ventilation contamination in a much more direct way than we would have expected originally,” says Lydia Bourouiba, an assistant professor in MIT’s Department of Civil and Environmental Engineering, and another co-author of the study.

Indeed, the cough or sneeze resembles, say, a puff emerging from a smokestack.

“But by elucidating the dynamics of the gas cloud, we have shown that there’s a circulation within the cloud — the smaller drops can be swept around and resuspended by the eddies within a cloud, and so settle more slowly. Basically, small drops can be carried a great distance by this gas cloud while the larger drops fall out. "

Specifically, the study finds that droplets 100 micrometers — or millionths of a meter — in diameter travel five times farther than previously estimated, while droplets 10 micrometers in diameter travel 200 times farther. Droplets less than 50 micrometers in size can frequently remain airborne long enough to reach ceiling ventilation units.

A cough or sneeze is a “multiphase turbulent buoyant cloud,” as the researchers term it in the paper, because the cloud mixes with surrounding air before its payload of liquid droplets falls out, evaporates into solid residues, or both.

The benefits of exercise and being fit keeps growing. From Medical Daily:

Physical Fitness In Your 20s Can Help Preserve Your Thinking Skills Later On In Life

If you need some motivation to get up off the couch and in your running shoes than how about this; a new study has proved that those who are fitter in their 20s are sharper thinkers in their middle age. So not only does exercise improve your health, slim your waistline, and lift your mood, but apparently it can also make you smarter. 

The study was carried out by researchers at the University of California, San Francisco. It started in 1985 and was conducted on nearly 3,000 19- to 30-year-olds in the U.S. The participants were asked to do a treadmill test and undergo physical examinations. They were asked to run for as long as they could without becoming exhausted or short of breath, according to the BBC. Then, 20 years later, the participants agreed to repeat the physical test. Five years after the second physical exam the participants underwent brain testing. These included a word recall test, a number-based test of attention, thinking speed and memory, and a test of how well people can focus while tuning out distractions. Results showed that the better people did on the treadmill test 20 years earlier, the better they did on the memory test. Also, those who had kept up their fitness later on in life scored the best overall in the memory tests. The researchers took into account factors such as weight, sex, drinking, smoking, and education. Still, those who did better on the treadmill test seemed to do better on the memory tests years later. 

The reasoning for this is that the brain uses a lot of oxygen and people who are fitter make more efficient use of oxygen. Also, exercise improves mitochondrial function, which is necessary in making use of energy. It is emphasized that this increase in brain function cannot be attributed to exercise alone. People who are physically fit are less likely to be sat in front of a television and more likely to interact with people and be engaged in life. “Just moving around — being engaged in family and life as opposed to sitting down and watching TV and pretty much not doing anything, they are going to preserve brain function. This is really about engagement in life,” lead researcher David Jacobs told NBC News. The study will continue by observing whether physical fitness in youth makes individuals less likely to develop Alzheimer’s disease later on in life. “Investment in research is vital to better understand how we can protect our brains as we age,” Jacobs concluded.

This research also ties in with another study released this week that showed young adults who had better heart health, as measured by blood pressure, have better thinking skills in middle age than those with high blood pressure.

Two studies published in the British Medical Journal (BMJ) looked at Vitamin D. From NY Times:

Low Vitamin D Levels Linked to Disease in Two Big Studies

People with low vitamin D levels are more likely to die from cancer and heart disease and to suffer from other illnesses, scientists reported in two large studies published on Tuesday.

The new research suggests strongly that blood levels of vitamin D are a good barometer of overall health. But it does not resolve the question of whether low levels are a cause of disease or simply an indicator of behaviors that contribute to poor health, like a sedentary lifestyle, smoking and a diet heavy in processed and unhealthful foods.

Nicknamed the sunshine nutrient, vitamin D is produced in the body when the skin is exposed to sunlight. It can be obtained from a small assortment of foods, including fish, eggs, fortified dairy products and organ meats, and vegetables like mushrooms and kale. And blood levels of it can be lowered by smoking, obesity, and inflammation.

Vitamin D helps the body absorb calcium and is an important part of the immune system. Receptors for the vitamin and related enzymes are found throughout cells and tissues of the body, suggesting it may be vital to many physiological functions, said Dr. Oscar H. Franco, a professor of preventive medicine at Erasmus Medical Center in the Netherlands and an author of one of the new studies, which appeared in the journal BMJ.

The two studies were meta-analyses that included data on more than a million people. They included observational findings on the relationship between disease and blood levels of vitamin D. The researchers also reviewed evidence from randomized controlled trials — the gold standard in scientific research — that assessed whether taking vitamin D daily was beneficial.

Dr. Franco and his co-authors — a team of scientists at Harvard, Oxford and other universities — found persuasive evidence that vitamin D protects against major diseases. Adults with lower levels of the vitamin in their systems had a 35 percent increased risk of death from heart disease, 14 percent greater likelihood of death from cancer, and a greater mortality risk overall.

When the researchers looked at supplement use, they found no benefit to taking vitamin D2. But middle-aged and older adults who took another form, vitamin D3 — which is the type found in fish and dairy products and produced in response to sunlight — had an 11 percent reduction in mortality from all causes, compared to adults who did not. In the United States and Europe, it is estimated that more than two-thirds of the population is deficient in vitamin D. In their paper, Dr. Franco and his colleagues calculated that roughly 13 percent of all deaths in the United States, and 9 percent in Europe, could be attributed to low vitamin D levels.

In the second study, also published in BMJ, a team of researchers at Stanford and several universities in Europe presented a more nuanced view of vitamin D.

They concluded there was “suggestive evidence” that high vitamin D levels protect against diabetes, stroke, hypertension and a host of other illnesses. But they also said there was no “highly convincing” evidence that vitamin D pills affected any of the outcomes they examined.

Dr. Theodoratou was not alone in suggesting people hold off on taking vitamin D supplements for now. Even though Dr. Franco found them to be beneficial, he said that more research was needed to show what levels are best. Instead of taking pills, people could improve their vitamin D levels with an adequate diet and 30 minutes of sunlight twice a week, he said.

A small study, but interesting to see if it holds up. Note that watermelon extract is not actual watermelon. From Science Daily:

Chowing down on watermelon could lower blood pressure, study suggests

A new study by Florida State University Associate Professor Arturo Figueroa, published in the American Journal of Hypertension, found that watermelon could significantly reduce blood pressure in overweight individuals both at rest and while under stress.

The study started with a simple concept. More people die of heart attacks in cold weather because the stress of the cold temperatures causes blood pressure to increase and the heart has to work harder to pump blood into the aorta. That often leads to less blood flow to the heart.

Thus, people with obesity and high blood pressure face a higher risk for stroke or heart attack when exposed to the cold either during the winter or in rooms with low temperatures.

So, what might help their hearts? It turned out that watermelon may be part of the answer.

Figueroa's 12-week study focused on 13 middle-aged, obese men and women who also suffered from high blood pressure. To simulate cold weather conditions, one hand of the subject was dipped into 39 degree water (or 4 degrees Celsius) while Figueroa's team took their blood pressure and other vital measurements.

Meanwhile, the group was divided into two. For the first six weeks, one group was given four grams of the amino acid L-citrulline and two grams of L-arginine per day, both from watermelon extract. The other group was given a placebo for 6 weeks. Then, they switched for the second six weeks. Participants also had to refrain from taking any medication for blood pressure or making any significant changes in their lifestyle, particularly related to diet and exercise, during the study.

The results showed that consuming watermelon had a positive impact on aortic blood pressure and other vascular parametersNotably, study participants showed improvements in blood pressure and cardiac stress while both at rest and while they were exposed to the cold water.

This exciting research opens a whole new way of thinking about the female breast and breast cancer. First of all, note that even our breasts have a microbiome (the microbial community). Key finding: the breast microbial population (specifically the bacteria) is different in healthy breasts (in the breast tissue) as compared to cancerous breasts. From Science Daily:

First look at breast microbiota raises tantalizing questions

The female breast contains a unique population of microbes relative to the rest of the body, according to the first-ever study of the breast microbiome. That study sought to lay the groundwork for understanding how this bacterial community contributes to health and disease, says first author Camilla Urbaniak, a PhD student at the University of Western Ontario. 

"Proteobacteria was the dominant phylum in healthy breast tissue," says Urbaniak, noting that it is found only in small proportions at other sites in the body. That may reflect the fact that breast tissue produces high concentrations of fatty acids, and these bacteria are fatty acid metabolizers. Proteobacteria is also the predominant phylum in human milk.

"The fact that beneficial bacteria, such as Lactobacillus and Bifidobacteria, were also detected makes us wonder whether their presence might be protective for both mother and child," says principal investigator Gregor Reid of the University of Western Ontario. Breast milk is one of the initial sources of gastrointestinal (GI) bacteria for newborns, and their GI microbiota are different if they are formula fed, says Urbaniak.

Conversely, Escherichia and Bacillus predominated in cancerous breasts.

"Strains of Escherichia have been shown to have mutagenic and carcinogenic activity in the gut and the bladder," says Urbaniak.

In the study, the investigators collected breast tissue from 81 women. Ten of these had undergone breast reduction, and their breast microbiota served as controls. The remaining women had had benign or cancerous tumors. The tissue collected from these women was taken from about five centimeters from the tumor, from what is known as "normal adjacent" tissue. Bacterial censuses were taken using a molecular technique known as 16S ribosomal sequencing, and with cultures.

Studies of the microbiome in other parts of the body, most notably the gastrointestinal tract, have shown that certain changes in bacterial populations can lead to a variety of ills, from obvious gastrointestinal conditions such as inflammatory bowel disease to those more unexpected, such as diabetes, obesity, cancer and even neurological conditions.

The complete reference: C. Urbaniak, J. Cummins, M. Brackstone, J. M. Macklaim, G. B. Gloor, C. K. Baban, L. Scott, D. M. O'Hanlon, J. P. Burton, K. P. Francis, M. Tangney, G. Reid.Bacterial microbiota of human breast tissueApplied and Environmental Microbiology, 2014; DOI: 10.1128/AEM.00242-14

The numbers are so staggering that at first I thought it was a joke (it being April 1). But no, these are the real study results. From Science Daily:

Eating seven or more portions of fruit and vegetables a day reduces your risk of death by 42 percent

Eating seven or more portions of fruit and vegetables a day reduces your risk of death at any point in time by 42% compared to eating less than one portion, reports a new UCL study.

Researchers used the Health Survey for England to study the eating habits of 65,226 people representative of the English population between 2001 and 2013, and found that the more fruit and vegetables they ate, the less likely they were to die at any age. Eating seven or more portions reduces the specific risks of death by cancer and heart disease by 25% and 31% respectively. The research also showed that vegetables have significantly higher health benefits than fruit.

Compared to eating less than one portion of fruit and vegetables, the risk of death by any cause is reduced by 14% by eating one to three portions, 29% for three to five portions, 36% for five to seven portions and 42% for seven or more. These figures are adjusted for sex, age, cigarette smoking, social class, Body Mass Index, education, physical activity and alcohol intake, and exclude deaths within a year of the food survey.

The study, published in the Journal of Epidemiology & Community Health, found that fresh vegetables had the strongest protective effect, with each daily portion reducing overall risk of death by 16%. Salad contributed to a 13% risk reduction per portion, and each portion of fresh fruit was associated with a smaller but still significant 4% reduction.

"We all know that eating fruit and vegetables is healthy, but the size of the effect is staggering," says Dr Oyinlola Oyebode of UCL's Department of Epidemiology & Public Health, lead author of the study. "The clear message here is that the more fruit and vegetables you eat, the less likely you are to die at any age. Vegetables have a larger effect than fruit, but fruit still makes a real difference. If you're happy to snack on carrots or other vegetables, then that is a great choice but if you fancy something sweeter, a banana or any fruit will also do you good."

The researchers found no evidence of significant benefit from fruit juice, and canned and frozen fruit appeared to increase risk of death by 17% per portion. The survey did not distinguish between canned and frozen fruit so this finding is difficult to interpret. Canned fruit products are almost four times more popular than frozen fruit in Europe*, so it is likely that canned fruit dominated this effect.

"Most canned fruit contains high sugar levels and cheaper varieties are packed in syrup rather than fruit juice," explains Dr Oyebode. "The negative health impacts of the sugar may well outweigh any benefits. Another possibility is that there are confounding factors that we could not control for, such as poor access to fresh groceries among people who have pre-existing health conditions, hectic lifestyles or who live in deprived areas."

This is a depressing research finding, with long-term negative results. From Science Daily:

Four in 10 infants lack strong parental attachments

In a study of 14,000 U.S. children, 40 percent lack strong emotional bonds -- what psychologists call "secure attachment" -- with their parents that are crucial to success later in life, according to a new report. The researchers found that these children are more likely to face educational and behavioral problems.

In a report published by Sutton Trust, a London-based institute that has published more than 140 research papers on education and social mobility, researchers from Princeton University, Columbia University, the London School of Economics and Political Science and the University of Bristol found that infants under the age of three who do not form strong bonds with their mothers or fathers are more likely to be aggressive, defiant and hyperactive as adults. These bonds, or secure attachments, are formed through early parental care, such as picking up a child when he or she cries or holding and reassuring a child.

Written by Moullin, Jane Waldfogel from Columbia University and the London School of Economics and Political Science and Elizabeth Washbrook from the University of Bristol, the report uses data collected by the Early Childhood Longitudinal Study, a nationally representative U.S. study of 14,000 children born in 2001. The researchers also reviewed more than 100 academic studies.

Their analysis shows that about 60 percent of children develop strong attachments to their parents, which are formed through simple actions, such as holding a baby lovingly and responding to the baby's needs. Such actions support children's social and emotional development, which, in turn, strengthens their cognitive development, the researchers write. These children are more likely to be resilient to poverty, family instability, parental stress and depression. Additionally, if boys growing up in poverty have strong parental attachments, they are two and a half times less likely to display behavior problems at school.

The approximately 40 percent who lack secure attachments, on the other hand, are more likely to have poorer language and behavior before entering school. This effect continues throughout the children's lives, and such children are more likely to leave school without further education, employment or training, the researchers write. Among children growing up in poverty, poor parental care and insecure attachment before age four strongly predicted a failure to complete school. Of the 40 percent who lack secure attachments, 25 percent avoid their parents when they are upset (because their parents are ignoring their needs), and 15 percent resist their parents because their parents cause them distress.

Susan Campbell, a professor of psychology at the University of Pittsburgh who studies social and emotional development in young children and infants, said insecure attachments emerge when primary caregivers are not "tuned in" to their infant's social signals, especially their cries of distress during infancy.

"When helpless infants learn early that their cries will be responded to, they also learn that their needs will be met, and they are likely to form a secure attachment to their parents," Campbell said. "However, when caregivers are overwhelmed because of their own difficulties, infants are more likely to learn that the world is not a safe place -- leading them to become needy, frustrated, withdrawn or disorganized."

The report, which is titled "Baby Bonds: Parenting, attachment and a secure base for children," was published March 21 by the Sutton Trust and is available online: http://www.suttontrust.com/our-work/research/item/baby-bonds/.

Hopefully these research results hold up for humans. But just the possibility is a wonderful and delicious reason to eat peaches. From Science Daily:

Peaches inhibit breast cancer metastasis in mice

Lab tests at Texas A&M AgriLife Research have shown that treatments with peach extract inhibit breast cancer metastasis in mice.

AgriLife Research scientists say that the mixture of phenolic compounds present in the peach extract are responsible for the inhibition of metastasis, according to the study, which was this month published in the Journal of Nutritional Biochemistry.

"Cancer cells were implanted under the skin of mice with an aggressive type of breast cancer cells, the MDA-MB-435, and what we saw was an inhibition of a marker gene in the lungs after a few weeks indicating an inhibition of metastasis when the mice were consuming the peach extract," said Dr. Luis Cisneros-Zevallos, a food scientist for AgriLife Research in College Station. "Furthermore, after determining the dose necessary to see the effects in mice, it was calculated that for humans it would be equivalent to consuming two to three peaches per day."

This work builds upon previous work at AgriLife Research released a few years ago, which showed that peach and plum polyphenols selectively killed aggressive breast cancer cells and not the normal ones, Cisneros-Zavallos said.

In the western hemisphere, breast cancer is the most common malignant disease for women, he said. In the U.S. last year, the American Cancer Society estimated about 232,340 new cases of invasive breast cancer among women.

The study was conducted using the peach variety Rich Lady. However, according to Cisneros-Zevallos, most peach fruit share similar polyphenolic compounds but might differ in content

"In general, peach fruit has chemical compounds that are responsible for killing cancer cells while not affecting normal cells as we reported previously, and now we are seeing that this mixture of compounds can inhibit metastasis," said Cisneros-Zevallos. "We are enthusiastic about the idea that perhaps by consuming only two to three peaches a day we can obtain similar effects in humans. However, this will have to be the next step in the study for its confirmation."

A totally off the wall study that I think will interest those who have wondered if we can control our dreams. This is especially appealing for everyone wanting pleasant dreams and wanting to avoid nightmares. From Science Daily:

Mass participation experiment reveals how to create the perfect dream

Today psychologist Professor Richard Wiseman from the University of Hertfordshire announces the results of a two-year study into dream control. The experiment shows that it is now possible for people to create their perfect dream, and so wake up feeling especially happy and refreshed.

In 2010, Professor Wiseman teamed-up with app developers YUZA to create 'Dream:ON' -- an iPhone app that monitors a person during sleep and plays a carefully crafted 'soundscape' when they dream. Each soundscape was carefully designed to evoke a pleasant scenario, such as a walk in the woods, or lying on a beach, and the team hoped that these sounds would influence people's dreams. At the end of the dream, the app sounded a gentle alarm and prompted the person to submit a description of their dream.

The app was downloaded over 500,000 times and the researchers collected millions of dream reports. After studying the data, Professor Wiseman discovered that the soundscapes did indeed influence people's dreams.

Richard Wiseman, professor in the Public Understanding of Psychology at the University of Hertfordshire, said: "If someone chose the nature landscape then they were more likely to have a dream about greenery and flowers. In contrast, if they selected the beach soundscape then they were more likely to dream about the sun beating down on their skin."

"In 2013, neuroscientists from the University of Basel discovered that people experience more disturbed sleeping patterns around the time of a full Moon," remarked Wiseman. "We have seen a similar pattern, with more bizarre dreams being associated with a full moon."

Finally, the team also found that certain soundscapes produced far more pleasant dreams.

The findings are described in Professor Wiseman's book on sleep and dreaming, Night School. The Dream:ON app and all of the soundscapes are currently available free of charge.

Last month (Feb. 12, 2014) I posted two studies that discussed the link between exercise and health, including eye health and macular degeneration. This following article builds on those studies to discuss the link between eye health and exercise, how exercise could protect our eyes from age-related vision loss, and even repair eye damage.

From the NY Times: Exercising for Healthier Eyes

There have been suggestions that exercise might reduce the risk of macular degeneration, which occurs when neurons in the central part of the retina deteriorate. The disease robs millions of older Americans of clear vision. A 2009 study of more than 40,000 middle-aged distance runners, for instance, found that th0se covering the most miles had the least likelihood of developing the disease. But the study did not compare runners to non-runners, limiting its usefulness. It also did not try to explain how exercise might affect the incidence of an eye disease. 

So, more recently, researchers at Emory University in Atlanta and the Atlanta Veterans Administration Medical Center in Decatur, Ga., took up that question for a study published last month in the Journal of Neuroscience. Their interest was motivated in part by animal research at the V.A. medical center. That work had determined that exercise increases the levels of substances known as growth factors in the animals’ bloodstream and brains. These growth factors, especially one called brain-derived neurotrophic factor, or B.D.N.F., are known to contribute to the health and well-being of neurons and consequently, it is thought, to improvements in brain health and cognition after regular exercise.

But the brain is not the only body part to contain neurons, as the researchers behind the new study knew. The retina does as well, and the researchers wondered whether exercise might raise levels of B.D.N.F. there, too, potentially affecting retinal health and vision.

To test that possibility, the researchers gathered adult, healthy lab mice. Half of these were allowed to remain sedentary throughout the day, while the other animals began running on little treadmills at a gentle rodent pace for about an hour a day. After two weeks, half of the mice in each group were exposed to a searingly bright light for four hours. The other animals stayed in dimly lit cages. This light exposure is a widely used and accepted means of inducing retinal degeneration in animals. It doesn’t precisely mimic the slowly progressing disease in humans, obviously. But it causes a comparable if time-compressed loss of retinal neurons.

The mice then returned to their former routine — running or not exercising — for another two weeks, after which the scientists measured the number of neurons in each animal’s eyes. The unexercised mice exposed to the bright light were experiencing, by then, severe retinal degeneration. Almost 75 percent of the neurons in their retinas that detect light had died. The animals’ vision was failing.

But the mice that had exercised before being exposed to the light retained about twice as many functioning retinal neurons as the sedentary animals; in addition, those cells were more responsive to normal light than the surviving retinal neurons in the unexercised mice. Exercise, it seems, had armored the runners’ retinas.

Separately, the researchers had other mice run or sit around for two weeks, and then measured levels of B.D.N.F. in their eyes and bloodstreams. The runners had far more. Tellingly, when the scientists injected still other mice with a chemical that blocks the uptake of the growth factor before allowing them to run and exposing them to the bright light, their eyes deteriorated as badly as among sedentary rodents. When the mice could not process B.D.N.F., exercise did not safeguard their eyes.

Taken together, these experiments strongly suggest that “exercise protects vision, at least in mice, by increasing B.D.N.F. in the retina,” said Jeffrey Boatright, an associate professor of ophthalmology at Emory University School of Medicine and a co-author of the study.

For now, she and Dr. Boatright said, people who are concerned about their vision, and especially those with a family history of retinal degeneration, might want to discuss an exercise program with their doctor. “As potential treatments go,” she said, “it’s cheap, easy and safe.”