30 maio 2015
Messier Craters in Stereo
Many bright nebulae and star clusters in planet Earth's sky are associated with the name of astronomer Charles Messier, from his famous 18th century catalog. His name is also given to these two large and remarkable craters on the Moon. Standouts in the dark, smooth lunar Sea of Fertility or Mare Fecunditatis, Messier (left) and Messier A have dimensions of 15 by 8 and 16 by 11 kilometers respectively. Their elongated shapes are explained by an extremely shallow-angle trajectory followed by the impactor, moving left to right, that gouged out the craters. The shallow impact also resulted in two bright rays of material extending along the surface to the right, beyond the picture. Intended to be viewed with red/blue glasses (red for the left eye), this striking stereo picture of the crater pair was recently created from high resolution scans of two images (AS11-42-6304, AS11-42-6305) taken during the Apollo 11 mission to the moon.
from NASA http://ift.tt/1QgEZs3
via IFTTT
the sun, photographed by sdo, 15th april 2015.24 frames,...
the sun, photographed by sdo, 15th april 2015.
24 frames, photographed over 6 hours. top: as photographed. bottom: aligned to the sun.
i don’t know if this sort of pointing is done intentionally (to image the wider corona, perhaps) or if it’s just the result of leaving the camera operating while the spacecraft performs some other function.
image credit: nasa/sdo, aia/eve/hmi. animation: ageofdestruction.
ageeyesonoakland: Here’s a sampling of insights we heard from...
We’re not sure exactly where she was born, or when she was...
We’re not sure exactly where she was born, or when she was born, but we know that Mary Harris was from somewhere in Cork County, Ireland, and immigrated to North America with her family as a child to escape the Irish famine. In her early twenties, she moved to Chicago, where she worked as a dressmaker, and then to Memphis, Tennessee, where she met and married George Jones, a skilled iron molder and staunch unionist. The couple had four children. Then tragedy struck: a yellow fever epidemic in 1867 took the lives of Mary’s husband and all four children. Mary Harris Jones returned to Chicago where she continued to sew, becoming a dressmaker for the wealthy. “I would look out of the plate glass windows and see the poor, shivering wretches, jobless and hungry, walking alongside the frozen lake front,” she said. “The tropical contrast of their condition with that of the tropical comfort of the people for whom I sewed was painful to me. My employers seemed neither to notice nor to care.” Then came the Great Chicago Fire of 1871. Mary once again lost everything.
After the fire, Mary began to travel across the country. The nation was undergoing dramatic change, and industrialization was changing the nature of work. She worked with the Knights of Labor, often giving speeches to inspire the workers during strikes. She organized assistance for workers’ strikes, and prepared for workers’ marches. In June 1897, after Mary addressed the railway union convention, she began to be referred to as “Mother” by the men of the union. The name stuck. That summer, when the 9,000-member Mine Workers called a nationwide strike of bituminous (soft coal) miners and tens of thousands of miners laid down their tools, Mary arrived in Pittsburgh to assist them. She became “Mother Jones” to millions of working men and women across the country for her efforts on behalf of the miners. Mother Jones was so effective the union would send her into mines, to help miners to join unions. In addition to miners, Mother Jones also was very concerned about child workers. To attract attention to the cause of abolishing child labor, in 1903, she led a children’s march of 100 children from the textile mills of Philadelphia to New York City “to show the New York millionaires our grievances.” She led the children all the way to President Theodore Roosevelt’s Long Island home.
A political progressive, she was a founder of the Social Democratic Party in 1898. Mother Jones also helped establish the Industrial Workers of the World in 1905. For all of her social reform and labor activities, she was considered by the authorities to be one of the most dangerous women in America. In 1912, Mother Jones was even charged with a capital offense by a military tribunal in West Virginia and held under house arrest for weeks until popular outrage and national attention forced the governor to release her. In her eighties, Mother Jones settled down near Washington, D.C., in 1921 but continued to travel across the country. She died, possibly aged 100, in 1930. Her final request was to be buried in the Miners Cemetery in Mt. Olive, Illinois, where you can visit her grave today.
Why Girls Are Starting Puberty EarlyFor the past two decades...
Why Girls Are Starting Puberty Early
For the past two decades scientists have been trying to unravel a mystery in young girls. Breast development, typical of 11-year-olds a generation ago, is now occurring in more seven-year-olds and, rarely, even in three-year-olds. That precocious development, scientists fear, may increase their risk for cancer or other illnesses later in life. Time has not resolved the puzzle. Nor is there any indication that this trend is slowing. More and more families are finding themselves in the strange position of juggling stuffed animals and puberty talks with their first and second graders.
Obesity appears to be the major factor sending girls into these unchartered waters. The rate of obesity has more than doubled in children over the past 30 years. And whereas only 7 percent of children aged six to 11 were obese in 1980, nearly 18 percent were obese in 2012. The latest studies, however, suggest that weight gain does not explain everything. Family stress and chemical exposures in the environment may also play a role, but the data do not yet paint a very clear picture of their contribution. As for boys, the data are murkier, but one 2012 study did suggest that they, too, may be starting puberty earlier than before—perhaps by as much as six months to two years.
Clinicians say that slightly early development of breasts is likely not physically harmful and so does not require medical or pharmaceutical therapy for most girls. (Among the few exceptions are pituitary disorders.) The psychological effects, though, are another matter that warrants more attention from schools and parents; early puberty seems to augment the risk of depression and to promote substance abuse and early initiation of sexual intercourse.
Obesity’s role
Precocious development was first thrust into the spotlight in 1997, when a landmark U.S. study declared that at least 5 percent of white and 15 percent of black girls had started to develop breasts by age seven—much earlier than expected. “That finding evoked a lot of passion,” says Paul B. Kaplowitz, a pediatric endocrinologist at Children’s National Health System in Washington, D.C. Moreover, the 1997 work found that the trend toward early development was not happening only in outliers. Puberty was happening earlier in most girls and again differed by race: instead of age 11, the typical age of breast development by the early 1990s was 8.87 years in African-Americans and 9.96 in white girls, researchers found. Other studies soon reached similar conclusions in Europe as well as the U.S. According to the most recent U.S. data (from 2013), 23 percent of black girls, 15 percent of Hispanic girls and 10 percent of white girls have started to develop breasts by the age of seven. Those findings suggest the proportion of girls with significantly earlier breast development may still be ticking upward.
From a biological point of view, whether puberty begins early or late, it still starts in the brain. Something cues the brain to produce a substance called gonadotropin-releasing hormone, or GnRH. This process activates the pituitary gland, which then signals the ovaries to produce estrogen, which in turn stimulates the breasts to grow and puberty to begin. (Pubic hair forms as the result of a different biological process.) Menstruation usually begins a few years later. Focusing too much on the latter meant researchers tended to overlook the breast trend.
The ovaries are not the only place in the body where estrogen is produced, however. Fat cells manufacture the hormone as well. Thus, with obesity levels on the rise around the world, it is not surprising that earlier puberty would result. Although girls’ breasts are developing earlier than before, the age at which they start to menstruate—and at which ovaries start pumping out large amounts of estrogen on a regular basis—has advanced by about only three months compared with decades past. As a result, puberty not only begins earlier but lasts longer than before.
The most obvious physical consequence of early puberty is a prolonged exposure to estrogen. Although excessive amounts of the hormone appear to increase the risk of developing breast cancer, no data so far indicate that starting one’s period a few months earlier than the previous norm exposes a girl to enough extra estrogen to cause a health problem. The potential effect probably is minimal, researchers say—particularly when weighed against myriad other factors—such as genetics, alcohol consumption and exercise—that also affect cancer risk. The much smaller exposure to estrogen that occurs in conjunction with early breast development has not yet been definitively studied.
Against that backdrop, many experts now believe parents should focus on the psychosocial consequences of early puberty rather than the potential physical risks. Frank M. Biro of Cincinnati Children’s Hospital Medical Center has spent his career studying puberty. He is also the father of three children. In his estimation, one of the biggest issues with early puberty is social well-being. “We interact with girls as they appear,” Biro says. “People relate to an early-maturing girl as if she is older than she is, but there is really no correlation between age of onset of puberty and one’s social or emotional maturation.” The result can be incredibly confusing for girls—who may face sexual innuendo or teasing long before they (or their parents) are ready for it.
Beyond obesity
Although researchers agree that obesity plays the central role in the earlier development of puberty, there is evidence implicating other factors as well. Lise Aksglaede and her colleagues at Rigshospitalet in Copenhagen followed more than 2,000 girls and discovered that although heavier individuals were indeed entering puberty earlier, a similar—if slightly less pronounced—trend also existed among normal-weight girls. In a 2009 study published in Pediatrics, they concluded that the increases in body mass index (a standard measure of weight in relation to height) between 1991 and 2006 were simply not large enough to account for girls’ breast development dropping by a year during that period. “In my view, this is the best study that suggests it may not all be body fat and that there’s something else here,” Kaplowitz says.
What might that something else include? Researchers have long suspected that exposure to certain compounds known as endocrine disruptors might have a part in triggering early puberty. These substances, among them pesticides, polychlorinated biphenyls and bisphenol A, mimic the effects of estrogen in the body—and so could potentially stimulate early breast growth. Discerning how much of an influence exposure to these chemicals might play is complicated, however, by the obesity epidemic. Because the body often stores chemicals in fat cells, an overweight girl is more likely to be exposed to more chemicals—making it difficult to apportion blame between endocrine disruptors and weight gain. Other investigators have implicated intense stresses in childhood, such as sometimes occurs with the absence of the biological father in the home or if a child is sensitive to conflict around her, as possible causes of earlier puberty—although the biological mechanism of action is not known. What is evident is that there is a symphony of moving parts to make puberty happen instead of a solo actor.
What to do?
Girls are not hapless creatures, of course, buffeted by the winds of change without any control over their actions. Regular physical activity may prove beneficial to help counteract at least some of the trend toward early puberty by improving mood and combating weight gain. Helping daughters to maintain a healthy diet rich in fruits and vegetables may also offer some protection, psychologist Julianna Deardorff and pediatric endocrinologist Louise Greenspan write in their new book, The New Puberty: How to Navigate Early Development in Today’s Girls.
One thing mothers can do to try to avoid the problem in the first place is to breast-feed their children. Children who are breast-fed appear to be less likely to enter puberty early, although the reasons are still unclear. A 2015 study that tracked some 1,200 girls and their mothers’ breast-feeding habits found that breast-feeding—and longer duration of breast-feeding—correlated with later onset of breast development in daughters in some populations. Parents and communities can also help protect girls from the painful psychological effects of early development. One way, Deardorff says, is preparing girls for puberty by talking about developmental changes in a positive, nonstigmatizing way. Living in a homogeneous neighborhood may also be helpful: early-maturing fifth graders of Mexican descent showed fewer symptoms of depression by seventh grade when they lived in Hispanic neighborhoods compared with similar girls living in more diverse neighborhoods, according to another study. It is unclear, however, why homogeneity may have helped.
Regardless of where girls live, they could well benefit from a change in school curriculums. Schools typically do not offer sexual education classes covering body maturation until fifth grade, when most children are around age 10 or 11. Puberty education should start earlier, Deardorff and Greenspan believe, with age-appropriate materials beginning in the first semester of fourth grade to more closely conform with present reality.
Identifying the triggers that push individual girls into early puberty remains a challenge that leaves parents short of a simple action plan. As Marcia E. Herman-Giddens, lead author of the watershed 1997 early puberty paper, says, “People always want to know the reason, but I don’t think people will ever be able to sort out the reason or the fix. It’s a lot of things interacting together, and they have different effects on different individuals.”
It remains to be seen if the early puberty trends will continue. “You would think at some point you would hit a biologic minimum, but I don’t know when that is or when it would be,” Biro says. Will every girl start maturing earlier? If obesity trends reverse course, will puberty begin later? As researchers look for answers, it is clear that parents and doctors alike need to be aware of the changes happening right now.
How Technology Affects Our Sleep Throughout your life, you’ve...
How Technology Affects Our Sleep
Throughout your life, you’ve probably been told how important sleep is for your body. However, did you know using technology could be negatively affecting your sleep patterns? According to The National Sleep Foundation, 95 percent of people surveyed admitted to using electronic devices prior to sleeping. Researchers have found using these devices so close to bedtime can lead to sleep disturbances, low energy and drowsy driving. Check out this infographic for more details on how technology affects your sleep – and what to avoid doing to get the best sleep possible for your body.
Updated Science: The New Zodiac
FYI, the croissant is still a croissant, but it has a lighter glaze.
Intrauterine devices (IUDs) and implants, known as Long-Acting...
Intrauterine devices (IUDs) and implants, known as Long-Acting Reversible Contraception (LARC), are the most effective types of birth control for teens. LARC is safe to use, does not require taking a pill each day or doing something each time before having sex, and can prevent pregnancy for 3 to 10 years, depending on the method. Less than 1% of LARC users would become pregnant during the first year of use.
(From CDC)
May 30th 1431: Joan of Arc burned at the stakeOn this day in...
Joan of Arc (1412-1431)
Joan of Arc burning at the stake
Memorial near spot of her death in Rouen
May 30th 1431: Joan of Arc burned at the stake
On this day in 1431, in Rouen, France the 19-year-old Joan of Arc was burned at the stake. The peasant girl, who claimed that God had chosen her and gave her divine guidance, led France’s army to several victories during the Hundred Years’ War. This long-running war aimed to liberate France from English control and establish the French crown prince Charles of Valois as King, making Joan of Arc a national heroine in France. She famously defied many of the gender norms of her day, refusing to marry, and dressing as a man in order to cross enemy territory to reach Charles’s palace. Joan had no military experience, but successfully led French forces to victory in several battles, including in the city of Orléans. However, Joan of Arc was captured by the English and put on trial for witchcraft and heresy, of which she was convicted. As was customary at the time, she was burned at the stake for her crimes. She was posthumously declared innocent and made a Catholic saint; this day is often celebrated to commemorate the remarkable story of Joan of Arc.
A cradleboard, by the Kootenai (Kutenai), who live in what we...
A cradleboard, by the Kootenai (Kutenai), who live in what we today call Idaho. Besides pretty, it is quite intricate with wood, cotton, glass and metal beads, shells, animal teeth, and twine all carved, sewn, and fringed together to make the elaborate patterns we see. (Circa 1880)
gov-info: CDC Gov Doc/Data: New Chronic Disease Indicators...
CDC Gov Doc/Data: New Chronic Disease Indicators Website
Chronic diseases represent seven of the top 10 deaths in the United States. The Chronic Disease Indicators (CDI) website is the only integrated source for comprehensive access to a wide range of key indicators for the surveillance of chronic diseases, conditions, and risk factors.
The redesigned and more user-friendly website also provides an online tool for users to compare data on the prevalence of chronic diseases in 40 large metropolitan areas, as well as at state and national levels.
What are Chronic Disease Indicators?
Established in 1999 these indicators provide access to relevant, up-to-date, and uniformly defined chronic disease surveillance data at the state and country level. There are currently 18 topic groups which comprise 124 indicators. These 18 categories represent a wide spectrum of conditions and risk factors as well as social context:
- Alcohol
- Arthritis
- Asthma
- Cancer
- Cardiovascular disease
- Chronic kidney disease
- Chronic obstructive pulmonary disease
- Diabetes
- Disability
- Immunization
- Mental health
- Nutrition, physical activity, and weight status
- Older adults
- Oral health
- Overarching conditions
- Reproductive health
- School health
- Tobacco
Chronic Disease Indicators is a joint project by the CDC and partner organizations– the National Association of Chronic Disease Directors and the Council of State and Territorial Epidemiologists.
May 29th 1953: Hillary and Norgay reach Everest summitOn this...
Norgay on Everest's summit
Hillary & Norgay near summit - May 28th
Hillary (left) and Norgay (right)
May 29th 1953: Hillary and Norgay reach Everest summit
On this day in 1953, Edmund Hillary and Sherpa Tenzing Norgay become the first people to reach the summit of the world’s highest mountain: Mount Everest. Many previous attempts to scale the peak had failed, but New Zealander Hillary and Nepalese Norgay reached the top (29,028 feet) at 11.30am local time on May 29th 1953. Norgay later revealed that Hillary had been the first to step onto the summit. The pair spent only 15 minutes taking pictures at the summit before they began their descent. Norgay left chocolates in the snow as an offering and Hillary left a cross that he had been given by John Hunt (leader of the expedition). News of their success reached London on the morning of Queen Elizabeth II’s coronation on June 2nd, and upon arrival in Kathmandu Hillary and Hunt discovered they had been knighted.
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