Chapter 16. None
Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.
Janet Raloff Over the last three years, growing evidence has shown that electronic cigarettes are not the harmless alternative to smoking that many proponents have argued. Now, a new study traces a large share of e-cigs’ toxic gases to a heat-triggered breakdown of the liquids used to create the vapors. And the hotter an e-cig gets — and the more it’s used — the more toxic compounds it emits, the study shows. “There is this image that e-cigarettes are a lot better than regular cigarettes, if not harmless,” says Hugo Destaillats, a chemist at Lawrence Berkeley National Laboratory in California. But after his team’s new analyses, published July 27 in Environmental Science & Technology, “we are now definitely convinced that they are far from harmless.” Electronic cigarettes draw liquids over one or more hot metal coils to transform them into vapors. Those liquids — polyethylene glycol, glycerin or a mix of the two — are food-grade solvents laced with flavorings and usually nicotine. The Berkeley team used two current models of e-cigs and three different commercially available e-liquids. The experimental setup mechanically drew air through the devices to create the vapors that a user would normally inhale. Heating up The higher an e-cigarette’s voltage, the more toxic aldehydes it produces in each puff of vapor. Once a certain threshold is hit, each voltage increase produces a disproportionate increase (see last bar) in acrolein, acetaldehyde and formaldehyde, three of the most harmful compounds in the vapor. |© Society for Science & the Public 2000 - 2016
Keyword: Drug Abuse
Link ID: 22490 - Posted: 07.28.2016
By ANDREW POLLACK A new type of drug for Alzheimer’s disease failed to slow the rate of decline in mental ability and daily functioning in its first large clinical trial. There was a hint, though, that it might be effective for certain patients. The drug, called LMTX, is the first one with its mode of action — trying to undo so-called tau tangles in the brain — to reach the final stage of clinical trials. So the results of the study were eagerly awaited. The initial reaction to the outcome was disappointment, with perhaps a glimmer of hopefulness. Over all, the patients who received LMTX, which was developed by TauRx Therapeutics, did not have a slower rate of decline in mental ability or daily functioning than those in the control group. However, the drug did seem to work for the subset of patients — about 15 percent of those in the study — who took LMTX as their only therapy. The other 85 percent of patients took an existing Alzheimer’s drug in addition to either LMTX or a placebo. “There were highly significant, clinically meaningful, large effects in patients taking the drug as monotherapy, and no effect in patients taking it as an add-on,” Claude Wischik, a founder and the chief executive of TauRx, said in an interview. He spoke from Toronto, where the results were being presented at the Alzheimer’s Association International Conference. Dr. Wischik said a second clinical trial sponsored by the company, whose results will be announced later, found the same phenomenon. He said the company planned to apply for approval of LMTX to be used by itself. But some experts not involved in the study were skeptical about drawing conclusions from a small subset of patients, especially since there was no obvious explanation why LMTX would be expected to work only in patients not getting other drugs. on © 2016 The New York Times Company
Link ID: 22488 - Posted: 07.28.2016
By PAM BELLUCK The World Health Organization is moving toward declassifying transgender identity as a mental disorder in its global list of medical conditions, with a new study lending additional support to a proposal that would delete the decades-old designation. The change, which has so far been approved by each committee that has considered it, is under review for the next edition of the W.H.O. codebook, which classifies diseases and influences the treatment of patients worldwide. “The intention is to reduce barriers to care,” said Geoffrey Reed, a psychologist who is coordinating the mental health and behavior disorders section in the upcoming edition of the codebook, called the International Classification of Diseases, or I.C.D. Dr. Reed, a professor at the National Autonomous University of Mexico and an author of the new study, said the proposal to remove transgender from the mental disorder category was “not getting opposition from W.H.O.,” suggesting that it appears likely to be included in the new edition. The revised volume would be the first in more than 25 years, and is scheduled to be approved in May 2018. Removing the mental health label from transgender identity would be a powerful signifier of acceptance, advocates and mental health professionals say. “It’s sending a very strong message that the rest of the world is no longer considering it a mental disorder,” said Dr. Michael First, a professor of clinical psychiatry at Columbia University and the chief technical consultant to the new edition of the codebook, which is known by its initials and the edition number I.C.D.-11. “One of the benefits of moving it out of the mental disorder section is trying to reduce stigma.” © 2016 The New York Times Company
Keyword: Sexual Behavior
Link ID: 22484 - Posted: 07.27.2016
By Jesse Singal As anyone who has read much about the subject can attest, the discussion about kids with gender dysphoria — that is, discomfort with their body and the feeling that they should have been born the other sex, or that they are the other sex — can get extremely heated and tricky. Much of the controversy stems from questions of age: How young is too young to help a child socially transition — that is, to change their name and pronoun, and possibly the way they present themselves? To prescribe them cross-sex hormones to begin the process of physically transitioning? For children with persistent gender dysphoria who are approaching adolescence, current best practice is to prescribe them so-called puberty blockers. Delaying the onset of puberty both forestalls the sometimes very uncomfortable experience of a child going through puberty in a body they aren’t comfortable in, and buys them and their families time to figure out what to do. Sometimes, this eventually leads to the prescription of cross-sex hormones, and sometimes it leads to surgery after that. Some people, though, are arguing that kids — particularly those who have socially transitioned at a young age — shouldn’t have to wait that long. Recently in the Guardian, for example, Kate Lyons reported on the current state of this debate in Britain: specifically, whether children who identify as transgender should be given access to cross-sex hormones, or possibly even surgery, at younger ages than what is current practice. © 2016, New York Media LLC.
Keyword: Sexual Behavior
Link ID: 22483 - Posted: 07.27.2016
An orangutan copying sounds made by researchers offers new clues to how human speech evolved, scientists say. Rocky mimicked more than 500 vowel-like noises, suggesting an ability to control his voice and make new sounds. It had been thought these great apes were unable to do this and, since human speech is a learned behaviour, it could not have originated from them. Study lead Dr Adriano Lameira said this "notion" could now be thrown "into the trash can". Dr Lameira, who conducted the research at Amsterdam University prior to joining Durham University, said Rocky's responses had been "extremely accurate". The team wanted to make sure the ape produced a new call, rather than adapting a "normal orangutan call with a personal twist" or matching sounds randomly or by coincidence, he said. The new evidence sets the "start line for scientific inquiry at a higher level", he said. "Ultimately, we should be now in a better position to think of how the different pieces of the puzzle of speech evolution fit together." The calls Rocky made were different from those collected in a large database of recordings, showing he was able to learn and produce new sounds rather than just match those already in his "vocabulary". In a previous study Dr Lameira found a female orangutan at Cologne Zoo in Germany was able to make sounds with a similar pace and rhythm to human speech. Researchers were "astounded" by Tilda's vocal skills but could not prove they had been learned, he said. However, the fact that "other orangutans seem to be exhibiting equivalent vocal skills shows that Rocky is not a bizarre or abnormal individual", Dr Lameira said. © 2016 BBC.
By PAM BELLUCK “Has the person become agitated, aggressive, irritable, or temperamental?” the questionnaire asks. “Does she/he have unrealistic beliefs about her/his power, wealth or skills?” Or maybe another kind of personality change has happened: “Does she/he no longer care about anything?” If the answer is yes to one of these questions — or others on a new checklist — and the personality or behavior change has lasted for months, it could indicate a very early stage of dementia, according to a group of neuropsychiatrists and Alzheimer’s experts. They are proposing the creation of a new diagnosis: mild behavioral impairment. The idea is to recognize and measure something that some experts say is often overlooked: Sharp changes in mood and behavior may precede the memory and thinking problems of dementia. The group made the proposal on Sunday at the Alzheimer’s Association International Conference in Toronto, and presented a 38-question checklist that may one day be used to identify people at greater risk for Alzheimer’s. “I think we do need something like this,” said Nina Silverberg, the director of the Alzheimer’s Disease Centers program at the National Institute on Aging, who was not involved in creating the checklist or the proposed new diagnosis. “Most people think of Alzheimer’s as primarily a memory disorder, but we do know from years of research that it also can start as a behavioral issue.” Under the proposal, mild behavioral impairment (M.B.I.) would be a clinical designation preceding mild cognitive impairment (M.C.I.), a diagnosis created more than a decade ago to describe people experiencing some cognitive problems but who can still perform most daily functions. © 2016 The New York Times Company
Link ID: 22480 - Posted: 07.26.2016
By Dave Dormer, Transporting babies deprived of oxygen at birth to a neonatal intensive care unit in Calgary will soon be safer thanks to a new portable cooling device. The Foothills hospital is one of the first facilities in Canada to acquire one and doctors hope it will help prevent brain injuries, as reducing a baby's temperature can prevent damage to brain tissue and promote healing. The reduction in temperature is called therapeutic hypothermia, and it can help prevent damage to brain tissue and promote healing. (Evelyne Asselin/CBC) "The period immediately following birth is critical. We have about a six-hour window to lower these babies' temperatures to prevent neurological damage," said Dr. Khorshid Mohammad, the neonatal neurocritical care project lead who spearheaded the initiative. "The sooner we can do so, and the more consistent we can make the temperature, the more protective it is and the better their chances of surviving without injury." Since about 2008, doctors used cooling blankets and gel packs to lower a baby's temperature to 33.5 C from the normal 37 C for 72 hours in order to prevent brain damage. "With those methods, it can be difficult to maintain a stable temperature," said Mohammad. ©2016 CBC/Radio-Canada.
Keyword: Development of the Brain
Link ID: 22476 - Posted: 07.26.2016
By Lizzie Wade Neandertals and modern humans had a lot in common—at least enough to have babies together fairly often. But what about their brains? To answer that question, scientists have looked at how Neandertal and modern human brains developed during the crucial time of early childhood. In the first year of life, modern human infants go through a growth spurt in several parts of the brain: the cerebellum, the parietal lobes, and the temporal lobes—key regions for language and social interaction. Past studies suggested baby Neandertal brains developed more like the brains of chimpanzees, without concentrated growth in any particular area. But a new study casts doubt on that idea. Scientists examined 15 Neandertal skulls, including one newborn and a pair of children under the age of 2. By carefully imaging the skulls, the team determined that Neandertal temporal lobes, frontal lobes, and cerebellums did, in fact, grow faster than the rest of the brain in early life, a pattern very similar to modern humans, they report today in Current Biology. Scientists had overlooked that possibility, the researchers say, because Neandertals and Homo sapiens have such differently shaped skulls. Modern humans’ rounded skull is a telltale marker of the growth spurt, for example, whereas Neandertals’ skulls were relatively flat on the top. If Neandertals did, in fact, have fast developing cerebellums and temporal and frontal lobes, they might have been more skilled at language and socializing than assumed, scientists say. This could in turn explain how the children of Neandertal–modern human pairings fared well enough to pass down their genes to so many us living today. © 2016 American Association for the Advancement of Science
By NATALIE ANGIER Their word is their bond, and they do what they say — even if the “word” on one side is a loud trill and grunt, and, on the other, the excited twitterings of a bird. Researchers have long known that among certain traditional cultures of Africa, people forage for wild honey with the help of honeyguides — woodpecker-like birds that show tribesmen where the best beehives are hidden, high up in trees. In return for revealing the location of natural honey pots, the birds are rewarded with the leftover beeswax, which they eagerly devour. Now scientists have determined that humans and their honeyguides communicate with each other through an extraordinary exchange of sounds and gestures, which are used only for honey hunting and serve to convey enthusiasm, trustworthiness and a commitment to the dangerous business of separating bees from their hives. The findings cast fresh light on one of only a few known examples of cooperation between humans and free-living wild animals, a partnership that may well predate the love affair between people and their domesticated dogs by hundreds of thousands of years. Claire N. Spottiswoode, a behavioral ecologist at Cambridge University, and her colleagues reported in the journal Science that honeyguides advertise their scout readiness to the Yao people of northern Mozambique by flying up close while emitting a loud chattering cry. For their part, the Yao seek to recruit and retain honeyguides with a distinctive vocalization, a firmly trilled “brrr” followed by a grunted “hmm.” In a series of careful experiments, the researchers then showed that honeyguides take the meaning of the familiar ahoy seriously. The birds were twice as likely to offer sustained help to Yao foragers who walked along while playing recordings of the proper brrr-hmm signal than they were to participants with recordings of normal Yao words or the sounds of other animals. © 2016 The New York Times Company
By Tanya Lewis Scientists have made significant progress toward understanding how individual memories are formed, but less is known about how multiple memories interact. Researchers from the Hospital for Sick Children in Toronto and colleagues studied how memories are encoded in the amygdalas of mice. Memories formed within six hours of each other activate the same population of neurons, whereas distinct sets of brain cells encode memories formed farther apart, in a process whereby neurons compete with their neighbors, according to the team’s study, published today (July 21) in Science. “Some memories naturally go together,” study coauthor Sheena Josselyn of the Hospital for Sick Children told The Scientist. For example, you may remember walking down the aisle at your wedding ceremony and, later, your friend having a bit too much to drink at the reception. “We’re wondering about how these memories become linked in your mind,” Josselyn said. When the brain forms a memory, a group of neurons called an “engram” stores that information. Neurons in the lateral amygdala—a brain region involved in memory of fearful events—are thought to compete with one another to form an engram. Cells that are more excitable or have higher expression of the transcription factor CREB—which is critical for the formation of long-term memories—at the time the memory is being formed will “win” this competition and become part of a memory. © 1986-2016 The Scientist
Keyword: Learning & Memory
Link ID: 22467 - Posted: 07.23.2016
Carl Zimmer The brain looks like a featureless expanse of folds and bulges, but it’s actually carved up into invisible territories. Each is specialized: Some groups of neurons become active when we recognize faces, others when we read, others when we raise our hands. On Wednesday, in what many experts are calling a milestone in neuroscience, researchers published a spectacular new map of the brain, detailing nearly 100 previously unknown regions — an unprecedented glimpse into the machinery of the human mind. Scientists will rely on this guide as they attempt to understand virtually every aspect of the brain, from how it develops in children and ages over decades, to how it can be corrupted by diseases like Alzheimer’s and schizophrenia. “It’s a step towards understanding why we’re we,” said David Kleinfeld, a neuroscientist at the University of California, San Diego, who was not involved in the research. Scientists created the map with advanced scanners and computers running artificial intelligence programs that “learned” to identify the brain’s hidden regions from vast amounts of data collected from hundreds of test subjects, a far more sophisticated and broader effort than had been previously attempted. While an important advance, the new atlas is hardly the final word on the brain’s workings. It may take decades for scientists to figure out what each region is doing, and more will be discovered in coming decades. “This map you should think of as version 1.0,” said Matthew F. Glasser, a neuroscientist at Washington University School of Medicine and lead author of the new research. “There may be a version 2.0 as the data get better and more eyes look at the data. We hope the map can evolve as the science progresses.” © 2016 The New York Times Company
Keyword: Brain imaging
Link ID: 22466 - Posted: 07.21.2016
Ian Sample Science editor When the German neurologist Korbinian Brodmann first sliced and mapped the human brain more than a century ago he identified 50 distinct regions in the crinkly surface called the cerebral cortex that governs much of what makes us human. Now researchers have updated the 100-year-old map in a scientific tour de force which reveals that the human brain has at least 180 different regions that are important for language, perception, consciousness, thought, attention and sensation. The landmark achievement hands neuroscientists their most comprehensive map of the cortex so far, one that is expected to supersede Brodmann’s as the standard researchers use to talk about the various areas of the brain. Scientists at Washington University in St Louis created the map by combining highly-detailed MRI scans from 210 healthy young adults who had agreed to take part in the Human Connectome Project, a massive effort that aims to understand how neurons in the brain are connected. Most previous maps of the human brain have been created by looking at only one aspect of the tissues, such as how the cells look under a microscope, or how active areas become when a person performs a certain task. But maps made in different ways do not always look the same, which casts doubt on where one part of the brain stops and another starts. Writing in the journal Nature, Matthew Glasser and others describe how they combined scans of brain structure, function and connectivity to produce the new map, which confirmed the existence of 83 known brain regions and added 97 new ones. Some scans were taken while patients simply rested in the machine, while others were recorded as they performed maths tasks, listened to stories, or categorised objects, for example by stating whether an image was of a tool or an animal. © 2016 Guardian News and Media Limited
Keyword: Brain imaging
Link ID: 22465 - Posted: 07.21.2016
You drift off to dreamland just fine but then something, a noise, a partner's tossing and turning, jars you awake. Now your mind races with an ever expanding to-do list of worries that you can't shut off. When the alarm buzzes, you start the day feeling grouchy and slightly dazed. Nearly six in 10 Canadians say they wake up feeling tired. About 40 per cent of Canadians will exhaust themselves with a sleep disorder at some point in their lifetime, studies suggest. It's common for people to wake up in the middle of the night. What's important is not to let it snowball, sleep specialists say. Our sleep cycles include brief periods of wakefulness but deep sleep makes us forget about these awakenings. "It's normal to have one or two a night," said Dr. Brian Murray, a sleep neurologist at Sunnybrook Health Sciences Centre and a professor at the University of Toronto. "It's when it's multiple that I worry." Sleep experts say if someone wakes up multiple times a night, it's a red flag. Chronic sleep problems are linked to heart disease, high blood pressure and some cancers. It can also affect hormone levels, which increases the risk of obesity and Type 2 diabetes, sleep specialists say. Julie Snyder of Toronto said she has stretches of days or weeks when she'll consistently wake up at 1:15 a.m., and again at 4 a.m. The broken sleep leaves her feeling short on patience. ©2016 CBC/Radio-Canada.
Link ID: 22463 - Posted: 07.21.2016
By David Levine Almost seven percent of U.S. adults—about 15.7 million people—are diagnosed with major depression disorder, according to the National Institute of Mental Health (NIMH). The Centers for Disease Control and Prevention report that depression causes 200 million lost workdays each year at a cost to employers of between $17 billion and $44 billion. The statistics for anxiety disorders are not great either. The most common mental illnesses in the U.S., they affect 40 million adults age 18 and older, costing the economy more than $42 billion a year. In my twenties, I developed panic disorder. I failed to get better on most medications and therapy. As I reported in an article earlier this year, it took me years to find a medication that worked. Because it took me so long to be diagnosed and treated properly, I have always been interested in alternative treatments for depression and anxiety. Two years ago I attended two sessions at the World Science Festival on the use of electrical therapy to treat depression and anxiety. The first event was Spark of Genius? Awakening a Better Brain, a panel discussion moderated by ABC News Chief Health & Medical Editor Richard Besser. The panel discussed what is known about treating the brain and the ethical and legal complications of brain enhancement. (You can watch it online at the World Science Festival website.) The second panel, "Electric Medicine and the Brain" was moderated by John Rennie, former editor in chief of Scientific American His panel focused on the use of "electroceuticals," a term coined by researchers at GlaxoSmithKline to refer to all implantable devices being used to treat mental illnesses and being explored in the treatment of metabolic, cardiovascular and inflammatory disorders. © 2016 Scientific American
Link ID: 22462 - Posted: 07.20.2016
Davide Castelvecchi People can detect flashes of light as feeble as a single photon, an experiment has demonstrated — a finding that seems to conclude a 70-year quest to test the limits of human vision. The study, published in Nature Communications on 19 July1, “finally answers a long-standing question about whether humans can see single photons — they can!” says Paul Kwiat, a quantum optics researcher at the University of Illinois at Urbana–Champaign. The techniques used in the study also open up ways of testing how quantum properties — such as the ability of photons to be in two places at the same time — affect biology, he adds. “The most amazing thing is that it’s not like seeing light. It’s almost a feeling, at the threshold of imagination,” says Alipasha Vaziri, a physicist at the Rockefeller University in New York City, who led the work and tried out the experience himself. Experiments on cells from frogs have shown that sensitive light-detecting cells in vertebrate eyes, called rod cells, do fire in response to single photons2. But, in part because the retina processes its information to reduce ‘noise’ from false alarms, researchers hadn’t been able to confirm whether the firing of one rod cell would trigger a signal that would be transmitted all the way to the brain. Nor was it clear whether people would be able to consciously sense such a signal if it did reach the brain. Experiments to test the limits of human vision have also had to wait for the arrival of quantum-optics technologies that can reliably produce one photon of light at a time. © 2016 Macmillan Publishers Limited
Link ID: 22461 - Posted: 07.20.2016
Ian Sample Science editor They were once considered merely lazy and adorable. But new research into the antics of the slow loris has revealed a wilder side to the docile creatures. Given the chance the innocent-eyed beasts will neck the most alcoholic drinks they can lay their paws on. The ability of the slow loris to seek out the most potent brew in reach was discovered by researchers in the US who wanted to know whether the animals favoured highly-fermented nectar over the less alcoholic forms secreted by plants in their natural habitats. As sugary nectar ferments in the wild, its calorie content rises, making it a potentially more valuable source of energy. In a series of tests with Dharma, an adult female slow loris, biologists at Dartmouth College in New Hampshire found that when presented with a choice of sugary solutions laced with different amounts of alcohol, the loris speedily settled on the most intoxicating. But while the animal was quickly drawn to the nectar substitutes, which contained between 1% and 4% alcohol, the slow loris displayed what the researchers describe as “a relative aversion to tap water”, which was used as a control. Dharma was not alone in her taste for drink. The scientists ran the same series of experiments with two nocturnal aye aye lemurs, a male called Merlin and a female called Morticia. Once again, the primates homed in on the most alcoholic of sugary solutions the researchers knocked up to mimic fermented nectar. © 2016 Guardian News and Media Limited
By TRIP GABRIEL DO you remember June 27, 2015? If you knew you had been on a sailboat, and that the weather was miserable, and that afterward you had a beer with the other sailors, would you expect to recall — even one year later — at least a few details? I was on that boat, on a blustery Saturday on Long Island Sound. But every detail is missing from my memory, as if snipped out by an overzealous movie editor. The earliest moment I recall from the day is lying in an industrial tube with a kind of upturned colander over my face, fighting waves of claustrophobia. My mind was densely fogged, but I understood that I was in an M.R.I. machine. Someone was scanning my brain. Other hazy scenes followed: being wheeled into a hospital room. My wife, Alice, hovering in the background. A wall clock that read minutes to midnight, an astonishing piece of information. What had happened to the day? Late that night, alone in the room, I noticed two yellow Post-its on the bedside table in Alice’s writing: “You have a condition called transient global amnesia. It will last Hours not DAYS. You’re going to be fine. Your CT scan was clear. You sailed today and drove yourself home,” the note read in part. I had never heard of transient global amnesia, a rare condition in which you are suddenly unable to recall recent events. Its causes are unknown. Unlike other triggers of memory loss, like a stroke or epileptic seizures, the condition is considered harmless, and an episode does not last long. “We don’t understand why it happens,” a neurologist would later tell me. “There are a million theories.” © 2016 The New York Times Company
Keyword: Learning & Memory
Link ID: 22456 - Posted: 07.19.2016
Tina Hesman Saey ORLANDO, Fla. — Weight gain may depend on how an individual’s genes react to certain diets, a new study in mice suggests. Four strains of mice fared differently on four different diets, William Barrington of North Carolina State University in Raleigh reported July 15 at the Allied Genetics Conference. One strain, the A/J mouse, was nearly impervious to dietary changes. Those mice didn’t gain much weight or have changes in insulin or cholesterol no matter what they ate: a fat-and-carbohydrate-laden Western diet, traditional Mediterranean or Japanese diet (usually considered healthy) or very low-carbohydrate, fat-rich fare known as the ketogenic diet. In contrast, NOD/ShiLtJ mice gained weight on all but the Japanese diet. Those mice’s blood sugar shot up — a hallmark of diabetes — on a Mediterranean diet, but decreased on the Japanese diet. FVB/NJ mice didn’t get fat on the Western diet, but became obese and developed high cholesterol and other health problems on the ketogenic diet. The opposite was true for C57BL/6J mice. They became obese and developed cholesterol and other problems linked to heart disease and diabetes in people on the Western diet, but not on the ketogenic diet. They also fattened up on the Mediterranean diet. © Society for Science & the Public 2000 - 2016.
Link ID: 22454 - Posted: 07.19.2016
By Maggie Koerth-Baker Q: I want to hear what the loudest thing in the world is! — Kara Jo, age 5 No. No, you really don’t. See, there’s this thing about sound that even we grown-ups tend to forget — it’s not some glitter rainbow floating around with no connection to the physical world. Sound is mechanical. A sound is a shove — just a little one, a tap on the tightly stretched membrane of your ear drum. The louder the sound, the heavier the knock. If a sound is loud enough, it can rip a hole in your ear drum. If a sound is loud enough, it can plow into you like a linebacker and knock you flat on your butt. When the shock wave from a bomb levels a house, that’s sound tearing apart bricks and splintering glass. Sound can kill you. Consider this piece of history: On the morning of Aug. 27, 1883, ranchers on a sheep camp outside Alice Springs, Australia, heard a sound like two shots from a rifle. At that very moment, the Indonesian volcanic island of Krakatoa was blowing itself to bits 2,233 miles away. Scientists think this is probably the loudest sound humans have ever accurately measured. Not only are there records of people hearing the sound of Krakatoa thousands of miles away, there is also physical evidence that the sound of the volcano’s explosion traveled all the way around the globe multiple times. Now, nobody heard Krakatoa in England or Toronto. There wasn’t a “boom” audible in St. Petersburg. Instead, what those places recorded were spikes in atmospheric pressure — the very air tensing up and then releasing with a sigh, as the waves of sound from Krakatoa passed through. There are two important lessons about sound in there: One, you don’t have to be able to see the loudest thing in the world in order to hear it. Second, just because you can’t hear a sound doesn’t mean it isn’t there. Sound is powerful and pervasive and it surrounds us all the time, whether we’re aware of it or not.
Link ID: 22453 - Posted: 07.19.2016
Paula Span An estimated one zillion older people have a problem like mine. First: We notice age-related hearing loss. A much-anticipated report on hearing health from the National Academies of Sciences, Engineering and Medicine last month put the prevalence at more than 45 percent of those aged 70 to 74, and more than 80 percent among those over 85. Then: We do little or nothing about it. Fewer than 20 percent of those with hearing loss use hearing aids. I’ve written before about the reasons. High prices ($2,500 and up for a decent hearing aid, and most people need two). Lack of Medicare reimbursement, because the original 1965 law creating Medicare prohibits coverage. Time and hassle. Stigma. Both the National Academies and the influential President’s Council of Advisors on Science and Technology have proposed pragmatic steps to make hearing technology more accessible and affordable. But until there’s progress on those, many of us with mild to moderate hearing loss may consider a relatively inexpensive alternative: personal sound amplification products, or P.S.A.P.s. They offer some promise — and some perils, too. Unlike for a hearing aid, you don’t need an audiologist to obtain a P.S.A.P. You see these gizmos advertised on the back pages of magazines or on sale at drugstore chains. You can buy them online. © 2016 The New York Times Company
Link ID: 22449 - Posted: 07.16.2016