Talk about making an impact. One of the meteorites that slammed into the planet early in its history could have kick-started life: the collision may have generated all four of the bases in RNA.
Life appeared on Earth around 4 billion years ago, about the same time that the planet was experiencing a beating from large meteorites - an event called theLate Heavy Bombardment. As far as Svatopluk Civiš at the Academy of Sciences of the Czech Republic in Prague and his colleagues are concerned, that's no coincidence.
They simulated a meteorite impact on early Earth by firing a high-power laser at samples of formamide – a liquid that would have existed on our primordial planet. The sample temperatures soared to 4200 °C, generating X-rays and extreme ultraviolet radiation that reacted with the formamide to create chemical radicals. These radicals, in turn, reacted with hydrogen and the remaining formamide to generate 2,3-diaminomaleonitrile – DAMN for short – which is a chemical precursor to the nucleobases.
When Civiš and his colleagues examined the end products of their reaction, they found all four RNA bases: adenine, guanine, cytosine and uracil – three of which are also found in DNA.
The work "nicely correlates the late heavy bombardment and the energy that it delivered to Earth with the formation of RNA and DNA nucleobases from formamide", says Steven Benner at the Foundation For Applied Molecular Evolution in Gainesville, Florida.
The work still doesn't quite answer the question of how the RNA bases came together with other complex molecules to form RNA, though. "This is what we are working on right now," says Civiš. For instance, they hope to generate carbohydrates through similar laser experiments.
‘The Invisible History of the Human Race’ Provides Transparency on Our Genetic Heritage
Books
By VIRGINIA HUGHES
Not so long ago, genealogy rested contentedly on the turf of hobbyists who enjoyed trolling dusty archives and filling pedigree charts. But over the past decade, because of the rise of digitized records and cheap DNA testing, the quaint pastime has turned into a lucrative commercial industry. Genealogy companies capitalize on consumers’ seemingly boundless curiosity about their personal origins. As the industry leader Ancestry.com implores on its home page: “Join us on a journey through the story of how you became, well, you.” What country did my great-great-grandparents come from? Were they rich? Adventurous? Powerful? How did they lead to me?
Answers to these questions go beyond, say, whether you belong in the Mayflower Society, or whether you are in the male line of Genghis Khan (which, by the way, roughly 16 million men are). They can upend lives, particularly those of adoptees or descendants of slaves.
But what receives far less attention is how genealogy can reveal secrets about all of us, at once: the emergence of our species, the political history of the world, and the origins of the social structures that dictate modern life. As Christine Kenneally writes in this engrossing new book, genealogy’s boom gives us “historical transparency” as never before.
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The Invisible History of the Human Race How DNA and History Shape Our Identities and Our Futures Viking Adult. 368 pages. $27.95.CreditPatricia Wall/The New York Times
“The Invisible History of the Human Race” is packed with stories that make this point, but one of the most intriguing comes from Ms. Kenneally’s own line. She was born in Australia, and after digging into genealogical records discovered what her grade-school self would have relished: a convict in the family. Her great-great-grandfather was sent, at age 15, from Dublin to the vast penal colony on the Australian island of Van Diemen’s Land.
Learning about her ancestor’s dark past (he had stolen a handkerchief) doesn’t shake her personal identity. But it does lead her to some profound insights about how a community keeps a secret. As the convict system wound down, in the mid-1800s, the people of Van Diemen’s Land changed the island’s name to Tasmania and stopped talking about their criminal roots. Newspapers wrote obliquely of “different regimes” or a “gloomy phase”; the word “convict” all but disappeared. Within a few generations, almost nobody in Tasmania knew that almost everybody had convict origins. For Ms. Kenneally, genealogical records revealed the truth.
DNA, too, holds myriad secrets of the past. After all, the biggest events in history — the migrations, wars and plagues — drastically influenced how people paired up and reproduced. With today’s technology, exposing this genetic legacy is astonishingly easy. For $99 or less, the three largest genetic genealogy companies — 23andMe, AncestryDNA and Family Tree DNA — will screen customers’ saliva for hundreds of thousands of genetic markers. Ms. Kenneally visits the Family Tree DNA headquarters in Houston and is stunned by its ordinariness: a generic office building with a back-room “DNA lab” containing a few noisy machines and an expensive freezer. “Once you have the right machines,” she notes, “you don’t need a lot of space or gleaming paraphernalia to uncover the mysteries of the human race.”
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The Secrets of our Genealogical Past 8:12
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DNA analyses can reveal surprises about the emergence of our species and the political and social structures that dictate modern life. Claire Maldarelli
That last phrase may sound grandiose, but it’s accurate. These DNA markers give clues about the evolution of our species in Africa some 200,000 years ago, and about the small band of people who left around 60,000 years ago. At the beginning of that diaspora, the wandering Homo sapiens sapiens evidently had close encounters with another species, the Neanderthal, because the molecular signatures of these couplings still exist deep inside their descendants’ cells.
DNA also sheds light on more recent historical events. Native Americans’ Y chromosomes, which are carried only by men, tend to have European signatures, for example, whereas their mitochondrial DNA, passed down from mothers, does not — indicating, perhaps, that male colonists killed native men and slept with native women. Genealogy makes many people squeamish because of its associations with racism. Ms. Kenneally digs deep into the roots of the eugenicist movement and the Third Reich, and indeed finds much ugliness: segregation, forced sterilization, breeding programs.
But she also shows how the suppression of genealogy can be malign. During China’s Cultural Revolution, for example, the Red Guard would often kill families who possessed records indicating that any of their ancestors were rich or powerful. And over the last century, tens of thousands of institutionalized children across the world have been denied access to information about their families — including, sometimes, their own names.
Genealogy, like most technologies, is morally neutral; it can be deployed for evil or for good. Though the Nazis used genealogy to justify racial hierarchies, today’s scientists are using it to dispel the notion of biological race altogether. As Ms. Kenneally points out, the categories we use to talk about race — black, white, Asian, Hispanic — are in large part cultural. Genetic differences among populations don’t fit into clear-cut boundaries.
In fact, if the genome has taught us anything, it is that our DNA has far less influence on our lives than the culture we are born into. And here lies the best argument for genealogy: It unearths nature and nurture, to make our invisible histories visible, free for all to know and to judge.
By Bonnie Berkowitz and Patterson Clark, Published: Jan. 20, 2014
We know sitting too much is bad, and most of us intuitively feel a little guilty after a long TV binge. But what exactly goes wrong in our bodies when we park ourselves for nearly eight hours per day, the average for a U.S. adult? Many things, say four experts, who detailed a chain of problems from head to toe. Download a pdf poster of this graphic.
Muscles burn less fat and blood flows more sluggishly during a long sit, allowing fatty acids to more easily clog the heart. Prolonged sitting has been linked to high blood pressure and elevated cholesterol, and people with the most sedentary time are more than twice as likely to have cardiovascular disease than those with the least.
OVERPRODUCTIVE PANCREAS
The pancreas produces insulin, a hormone that carries glucose to cells for energy. But cells in idle muscles don't respond as readily to insulin, so the pancreas produces more and more, which can lead to diabetes and other diseases. A 2011 study found a decline in insulin response after just one day of prolonged sitting.
COLON CANCER
Studies have linked sitting to a greater risk for colon, breast and endometrial cancers. The reason is unclear, but one theory is that excess insulin encourages cell growth. Another is that regular movement boosts natural antioxidants that kill cell-damaging — and potentially cancer-causing — free radicals.
Muscle degeneration
MUSHY ABS
When you stand, move or even sit up straight, abdominal muscles keep you upright. But when you slump in a chair, they go unused. Tight back muscles and wimpy abs form a posture-wrecking alliance that can exaggerate the spine's natural arch, a condition called hyperlordosis, or swayback.
TIGHT HIPS
Flexible hips help keep you balanced, but chronic sitters so rarely extend the hip flexor muscles in front that they become short and tight, limiting range of motion and stride length. Studies have found that decreased hip mobility is a main reason elderly people tend to fall.
LIMP GLUTES
Sitting requires your glutes to do absolutely nothing, and they get used to it. Soft glutes hurt your stability, your ability to push off and your ability to maintain a powerful stride.
Leg disorders
POOR CIRCULATION IN LEGS
Sitting for long periods of time slows blood circulation, which causes fluid to pool in the legs. Problems range from swollen ankles and varicose veins to dangerous blood clots called deep vein thrombosis (DVT).
SOFT BONES
Weight-bearing activities such as walking and running stimulate hip and lower-body bones to grow thicker, denser and stronger. Scientists partially attribute the recent surge in cases of osteoporosis to lack of activity.
Trouble at the top
FOGGY BRAIN
Moving muscles pump fresh blood and oxygen through the brain and trigger the release of all sorts of brain- and mood-enhancing chemicals. When we are sedentary for a long time, everything slows, including brain function.
STRAINED NECK
If most of your sitting occurs at a desk at work, craning your neck forward toward a keyboard or tilting your head to cradle a phone while typing can strain the cervical vertebrae and lead to permanent imbalances.
SORE SHOULDERS AND BACK
The neck doesn't slouch alone. Slumping forward overextends the shoulder and back muscles as well, particularly the trapezius, which connects the neck and shoulders.
Bad back
INFLEXIBLE SPINE
When we move around, soft discs between vertebrae expand and contract like sponges, soaking up fresh blood and nutrients. But when we sit for a long time, discs are squashed unevenly. Collagen hardens around supporting tendons and ligaments.
DISK DAMAGE
People who sit more are at greater risk for herniated lumbar disks. A muscle called the psoas travels through the abdominal cavity and, when it tightens, pulls the upper lumbar spine forward. Upper-body weight rests entirely on the ischial tuberosity (sitting bones) instead of being distributed along the arch of the spine.
Mortality of sitting
People who watched the most TV in an 8.5-year study had a 61 percent greater risk of dying than those who watched less than one hour per day.
4%
14%
31%
61%
1-2
3-4
5-6
7+
Hours of TV per day
The right way to sit
If you have to sit often, try to do it correctly. As Mom always said, "Sit up straight."
• Not leaning forward
• Shoulders relaxed
• Arms close to sides
• Elbows bent 90°
• Lower back may be supported
• Feet flat on floor
So what can we do? The experts recommend . . .
Sitting on something wobblysuch as an exercise ball or even a backless stool to force your core muscles to work. Sit up straight and keep your feet flat on the floor in front of you so they support about a quarter of your weight.
Stretching the hip flexorsfor three minutes per side once a day.
Walking during commercials when you're watching TV. Even a snail-like pace of 1 mph would burn twice the calories of sitting, and more vigorous exercise would be even better.
Alternating between sitting and standing at your work station. If you can't do that, stand up every half hour or so and walk.
Trying yoga poses — the cow pose and the cat — to improve extension and flexion in your back.
THE EXPERTS
| Scientists interviewed for this report
James A. Levine, inventor of the treadmill desk and director of Obesity Solutions at Mayo Clinic and Arizona State University. Charles E. Matthews, National Cancer Institute investigator and author of several studies on sedentary behavior. Jay Dicharry, director of the REP Biomechanics Lab in Bend, Ore., and author of "Anatomy for Runners." Tal Amasay, biomechanist at Barry University's Department of Sport and Exercise Sciences.
Additional sources: "Amount of time spent in sedentary behaviors and cause-specific mortality in U.S. adults," by Charles E. Matthews, et al, of the National Cancer Institute; "Sedentary behavior and cardiovascular disease: A review of prospective studies," by Earl S. Ford and Carl J. Casperson of the Centers for Disease Control and Prevention; Mayo Clinic.
First developed in China in about the year A.D. 150, paper has many uses, the most common being for writing and printing upon. Indeed, the development and spread of civilization owes much to paper's use as writing material.
According to some surveys, 90 percent of all information in businesses today is retained on paper, even though the bulk of this printed paper is discarded after just one-time use.
Such waste of paper (and ink cartridges) -- not to mention the accompanying environmental problems such as deforestation and chemical pollution to air, water and land -- could be curtailed if the paper were "rewritable," that is, capable of being written on and erased multiple times.
Chemists at the University of California, Riverside have now fabricated in the lab just such novel rewritable paper, one that is based on the color switching property of commercial chemicals called redox dyes. The dye forms the imaging layer of the paper. Printing is achieved by using ultraviolet light to photobleach the dye, except the portions that constitute the text on the paper. The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution.
"This rewritable paper does not require additional inks for printing, making it both economically and environmentally viable," said Yadong Yin, a professor of chemistry, whose lab led the research. "It represents an attractive alternative to regular paper in meeting the increasing global needs for sustainability and environmental conservation."
Study results appear online today (Dec. 2) in Nature Communications.
The rewritable paper is essentially rewritable media in the form of glass or plastic film to which letters and patterns can be repeatedly printed, retained for days, and then erased by simple heating.
The paper comes in three primary colors: blue, red and green, produced by using the commercial redox dyes methylene blue, neutral red and acid green, respectively. Included in the dye are titania nanocrystals (these serve as catalysts) and the thickening agent hydrogen cellulose (HEC). The combination of the dye, catalysts and HEC lends high reversibility and repeatability to the film.
During the writing phase, ultraviolet light reduces the dye to its colorless state. During the erasing phase, re-oxidation of the reduced dye recovers the original color; that is, the imaging material recovers its original color by reacting with ambient oxygen. Heating at 115 C can speed up the reaction so that the erasing process is often completed in less than 10 minutes.
"The printed letters remain legible with high resolution at ambient conditions for more than three days -- long enough for practical applications such as reading newspapers," Yin said. "Better still, our rewritable paper is simple to make, has low production cost, low toxicity and low energy consumption."
His lab is currently working on a paper version of the rewritable paper.
"Even for this kind of paper, heating to 115 C poses no problem," Yin said. "In conventional laser printers, paper is already heated to 200 C in order to get toner particles to bond to the paper surface."
His lab also is working on increasing the cycling number (the number of times the rewritable paper can be printed and erased), with a target of 100, to reduce overall cost. His research team is exploring ways to extend the legibility of the printed texts or images for more than three days to expand their potential uses.
"One way is to develop new photocatalyst nanoparticles that become highly reductive when irradiated by ultraviolet light," Yin said. "We are exploring, too, the possibility of multi-color printing. The design principle can be extended to various commercial redox dyes to produce rewritable paper capable of showing prints of different colors. All these efforts will help increase the practical applications of the technology."
He was joined in the study by UC Riverside's Wenshou Wang (first author of the research paper), Ning Xie and Le He. Wang and Yin conceived and designed the experiments. Wang performed the experiments. Xie and He contributed to sample analysis. Wang and Yin analyzed the results.
The research was funded by a grant to Yin from the U.S. Department of Energy.
This technology has been disclosed and assigned UC case number 2015-250. A provisional patent has been filed and the UCR Office of Technology Commercialization is actively seeking a company to license the technology.
Yin's lab has recently synthesized a colloidal titania nanoparticle catalyst doped with barium ions that enables reversible light-responsive color switching with excellent cycling performance and considerably high switching rate.
"The improved performance is attributed to the more effective removal of the photogenerated oxidative holes that results from barium doping. This leaves more electrons for promoting the reduction of redox dyes," Yin said.
The finding was recently reported in Angewandte Chemie.
hope you and your loved ones share a healthy holiday season full of laughter!
State Representative 14th Middlesex District
Legislation
This fall I worked with Middlesex District Attorney, Marian Ryan and filed a bill to update state drug laws to include a new synthetic chemical drug that is illegal under federal drug laws but not yet Massachusetts. This bill will include this chemical compound, NBOMe, as a Class B substance, making it illegal to possess or sell. The drug can be similar in appearance to LSD and used as a hallucinogen.
The federal Drug Enforcement Administration has issued an emergency ruling classifying NBOMe as a dangerous drug, but Massachusetts has not yet changed its laws. Without legal authority, Massachusetts state and local police cannot arrest a person for possession or distribution of this drug, nor can the district attorneys prosecute it. After this drug had been found by police in Middlesex County involving teenagers from Concord, Chelmsford, and Westford I believed this demanded a rapid response. I am pleased we were able to file this bill immediately and am hopeful that this bill will pass soon. It is important that we get this bill passed and give our police the resources they need to fight this dangerous substance and keep our communities safe.
Researchers have found that people diagnosed with diabetes in their 50’s are significantly more likely than others to suffer mental decline by their 70’s.
The study, published Monday in the Annals of Internal Medicine, started in 1990. Scientists examined 13,351 black and white adults, aged 48 to 67, for diabetes and prediabetes using self-reported physician diagnoses and glucose control tests. They also administered widely used tests of memory, reasoning, problem solving and planning.
About 13 percent had diabetes at the start. The researchers followed them with five periodic examinations over the following 20 years. By that time, 5,987 participants were still enrolled.
After adjusting for numerous health and behavioral factors, and for the large attrition in the study, the researchers found people with diabetes suffered a 30 percent larger decline in mental acuity than those without the disease.
Regular consumption of yogurt may help lower the risk for Type 2 diabetes, a new study has found.
Researchers followed almost 200,000 men and women ages 25 to 75 for as long as 30 years, tracking their health with periodic interviews and their diets with detailed food questionnaires. They found 15,156 cases of Type 2 diabetes over the course of the study. Then they pooled their data with data from previous studies in a meta-analysis. The report appears online in BMC Medicine.
After adjusting for age, body mass index, smoking, hypertension and many other health and behavioral characteristics, they found that total dairy consumption, either high-fat or low-fat, was not associated with the risk for Type 2 diabetes.
But yogurt was different. Compared to eating the average amount of 4 ounces a day, eating 12 ounces a day was associated with an 18 percent reduction in the risk for Type 2 diabete
