Weird Ancient Black Hole Has Extra Suck.


Astronomers observing distant quasars have discovered something puzzling about a very rare class of these enigmatic objects — some appear to be sucking material inwards at relativistic speeds, whereas the vast majority of quasars do exactly the opposite.

Quasars dominated the early Cosmos, generating vast quantities of radiation that can be observed today right at the edge of our observable Universe. Consisting of an active supermassive black hole and a searing disk of plasma in the cores of young galaxies, the vast majority of quasars eject material from their energetic environments at high speed.

This may sound counter-intuitive; black holes consume matter after all, they don’t eject it. But in a quasar’s hot accretion disk — composed of a superheated soup of blended stars, gas and dust that strayed too close to the supermassive black hole’s gravitational wrath — the intense radiation blasts the surrounding material away from the black hole. Although some material inevitably gets fed from the accretion disk into the black hole, vast quantities are ejected at up to a significant fraction of the speed of light.

However, by taking a Doppler speed check of the motion of gas around known quasars, a team of researchers analyzing data from the Sloan Digital Sky Survey (SDSS-III) have discovered a very rare subset of quasars that don’t fit the norm.

“The gas in this new type of quasar is moving in two directions: some is moving toward Earth but most of it is moving at high velocities away from us, possibly toward the quasar’s black hole,” said Niel Brandt, study co-author and Distinguished Professor of Astronomy and Astrophysics at Penn State University. “Just as you can use the Doppler shift for sound to tell if an airplane is moving away from you or toward you, we used the Doppler shift for light to tell whether the gas in these quasars is moving away from Earth or toward these distant black holes, which have a mass from millions to billions of times that of the sun.”

“Matter falling into black holes may not sound surprising,” added team leader Patrick Hall of York University in Toronto, “but what we found is, in fact, quite mysterious and was not predicted by current theories.

“The gas in the disc must eventually fall into the black hole to power the quasar, but what is often seen instead is gas blown away from the black hole by the heat and light of the quasar, heading toward us at velocities up to 20 percent of the speed of light,” he said. “If the gas is falling into the black hole, then we don’t understand why it’s so rare to see infalling gas. There’s nothing else unusual about these quasars. If gas can be seen falling into them, why not in other quasars?”

So how rare are these objects? 1-in-10,000 rare. Of the tens of thousands of quasars known, only 17 such objects have been discovered so far.

For now, the researchers are baffled as to why these few distant supermassive black holes, which have masses millions to billions of times of the mass of our sun, appear to have more suck than the rest of their quasar cousins. Their work has been published in the journal Monthly Notices of the Royal Astronomical Society (doi: 10.1093/mnras/stt1012).

One explanation, says Hall, is that in actuality, the majority of gas is being ejected from the quasar, but it is moving in a peculiar fashion. Perhaps gas is rapidly orbiting around the black hole’s superheated accretion disk, sometimes traveling toward, sometimes away from us, but the Doppler measurements appear to show a bias toward the gas that is moving away. This may give the impression that the gas is being sucked into the black hole, when, in fact, it’s being ejected.

Regardless, these are strange objects that don’t appear to fit with current quasar theory, something astrophysicists will have to work on for a while yet.

Source: Physorg.com

California coastline hosts ‘Great Pacific Garbage Patch’


Tons of plastic have accumulated in an area between Hawaii and California, and the convergence of currents swirls the trash into what is now known as the Great Pacific Garbage Patch.

Bottle caps, trash bags and broken plastic are now part of the diet of many birds and sea creatures around the world.

It’s very depressing, initially, to realize the extent of the problem,” said Captain Charles Moore, founder of Alagalita Marine Research Institute.

One of the largest concentrations of marine debris is in the Pacific Ocean, halfway between Hawaii and California. It’s called the Great Pacific Garbage Patch.

Moore accidentally found the garbage patch in 1997 while sailing through a gyre, where ocean currents circulate and accumulate trash.

It’s a piece here, a piece there. It’s not a solid island. In general what we see is a soup of plastic. Not really an island of plastic,” said Moore.

Next year, Captain Moore is planning to spend a month at the Garbage Patch to research its effects on the food chain.

It is difficult to see the collection of trash from above because it’s made up of pieces of plastic the size of a finger nail. Researchers believe that there could be 2 million of these little pieces of plastic per square mile.

Millions of creatures are dying every year, tangled in plastic,” said Moore.

It’s not just the wildlife that is being fooled into eating this stuff and getting tangled in it, it’s we ourselves that are changing our biological being with these chemicals in this hyper-consumptive world that we live in,” Moore added.

Scientists at the Scripps Institution of Oceanography in San Diego have also been trying to figure out how the marine debris is changing the world. A Scripps study estimated that fish in the intermediate ocean depths of the North Pacific Ocean ingest plastic at a rate of roughly 12,000 to 24,000 tons per year.

Cleaning up the mess that’s already been made is likely impossible, but experts believe the problem could potentially be saved with a radical change in economic and social culture.

When you hear politicians talk about growth, you would think it’s one of the 10 Commandments,” said Moore.

Our very being is consumers of products. This defines us these days. The type of car we have, the type of shoes we wear. The type of hair gel we do. The band of clothing we have. This is how we get our identity,” Moore added.

Moore argues that consumption habits and our creature comforts have led to an earth shattering problem: where to put all of the trash we generate.

We have to really redefine ourselves as human beings, as something other than a consumer in order to beat this problem,” said Moore.

New shorelines created of trash are appearing in all oceans, and even in America’s Great Lakes.

As world economies continue to thrive on mass consumption, Captain Moore will continue to sail and study the plastic oceans.

Why Time Slows Down When We’re Afraid, Speeds Up as We Age, and Gets Warped on Vacation.


Time perception matters because it is the experience of time that roots us in our mental reality.”

Given my soft spot for famous diaries, it should come as no surprise that I keep one myself. Perhaps the greatest gift of the practice has been the daily habit of reading what I had written on that day a year earlier; not only is it a remarkable tool of introspection and self-awareness, but it also illustrates that our memory “is never a precise duplicate of the original [but] a continuing act of creation” and how flawed our perception of time is — almost everything that occurred a year ago appears as having taken place either significantly further in the past (“a different lifetime,” I’d often marvel at this time-illusion) or significantly more recently (“this feels like just last month!”). Rather than a personal deficiency of those of us befallen by this tendency, however, it turns out to be a defining feature of how the human mind works, the science of which is at first unsettling, then strangely comforting, and altogether intensely interesting.

That’s precisely what acclaimed BBC broadcaster and psychology writer Claudia Hammond explores in Time Warped: Unlocking the Mysteries of Time Perception (public library) — a fascinating foray into the idea that our experience of time is actively created by our own minds and how these sensations of what neuroscientists and psychologists call “mind time” are created. As disorienting as the concept might seem — after all, we’ve been nursed on the belief that time is one of those few utterly reliable and objective things in life — it is also strangely empowering to think that the very phenomenon depicted as the unforgiving dictator of life is something we might be able to shape and benefit from. Hammond writes:

We construct the experience of time in our minds, so it follows that we are able to change the elements we find troubling — whether it’s trying to stop the years racing past, or speeding up time when we’re stuck in a queue, trying to live more in the present, or working out how long ago we last saw our old friends. Time can be a friend, but it can also be an enemy. The trick is to harness it, whether at home, at work, or even in social policy, and to work in line with our conception of time. Time perception matters because it is the experience of time that roots us in our mental reality. Time is not only at the heart of the way we organize life, but the way we experience it.

Discus chronologicus, a depiction of time by German engraver Christoph Weigel, published in the early 1720s; from Cartographies of Time. (Click for details)

Among the most intriguing illustrations of “mind time” is the incredible elasticity of how we experience time. (“Where is it, this present?,” William James famously wondered. “It has melted in our grasp, fled ere we could touch it, gone in the instant of becoming.”) For instance, Hammond points out, we slow time down when gripped by mortal fear — the cliche about the slow-motion car crash is, in fact, a cognitive reality. This plays out even in situations that aren’t life-or-death per se but are still associated with strong feelings of fear. Hammond points to a study in which people with arachnophobia were asked to look at spiders — the very object of their intense fear — for 45 seconds and they overestimated the elapsed time. The same pattern was observed in novice skydivers, who estimated the duration of their peers’ falls as short, whereas their own, from the same altitude, were deemed longer.

Inversely, time seems to speed up as we get older — a phenomenon of which competing theories have attempted to make light. One, known as the “proportionality theory,” uses pure mathematics, holding that a year feels faster when you’re 40 than when you’re 8 because it only constitutes one fortieth of your life rather than a whole eighth. Among its famous proponents are Vladimir Nabokov and William James. But Hammond remains unconvinced:

The problem with the proportionality theory is that it fails to account for the way we experience time at any one moment. We don’t judge one day in the context of our whole lives. If we did, then for a 40-year-old every single day should flash by because it is less than one fourteen-thousandth of the life they’ve had so far. It should be fleeting and inconsequential, yet if you have nothing to do or an enforced wait at an airport for example, a day at 40 can still feel long and boring and surely longer than a fun day at the seaside packed with adventure for a child. … It ignores attention and emotion, which … can have a considerable impact on time perception.

Another theory suggests that perhaps it is the tempo of life in general that has accelerated, making things from the past appear as slower, including the passage of time itself.

But one definite change does take place with age: As we grow older, we tend to feel like the previous decade elapsed more rapidly, while the earlier decades of our lives seem to have lasted longer. Similarly, we tend to think of events that took place in the past 10 years as having happened more recently than they actually did. (Quick: What year did the devastating Japanese tsunami hit? When did we love Maurice Sendak?) Conversely, we perceive events that took place more than a decade ago as having happened even longer ago. (When did Princess Diana die? What year was the Chernobyl disaster?) This, Hammond points out, is known as “forward telescoping”:

It is as though time has been compressed and — as if looking through a telescope — things seem closer than they really are. The opposite is called backward or reverse telescoping, also known as time expansion. This is when you guess that events happened longer ago than they really did. This is rare for distant events, but not uncommon for recent weeks.

[…]

The most straightforward explanation for it is called the clarity of memory hypothesis, proposed by the psychologist Norman Bradburn in 1987. This is the simple idea that because we know that memories fade over time, we use the clarity of a memory as a guide to its recency. So if a memory seems unclear we assume it happened longer ago.

And yet the brain does keep track of time, even if inaccurately. Hammond explains the factors that come into play with our inner chronometry:

It is clear that however the brain counts time, it has a system that is very flexible. It takes account of [factors like] emotions, absorption, expectations, the demands of a task and even the temperature .The precise sense we are using also makes a difference; an auditory event appears longer than a visual one. Yet somehow the experience of time created by the mind feels very real, so real that we feel we know what to expect from it, and are perpetually surprised whenever it confuses us by warping.

In fact, memory — which is itself a treacherous act of constant transformation with each recollection — is intricately related to this warping process:

We know that time has an impact on memory, but it is also memory that creates and shapes our experience of time. Our perception of the past moulds our experience of time in the present to a greater degree than we might realize. It is memory that creates the peculiar, elastic properties of time. It not only gives us the ability to conjure up a past experience at will, but to reflect on those thoughts through autonoetic consciousness — the sense that we have of ourselves as existing across time — allowing us to re-experience a situation mentally and to step outside those memories to consider their accuracy.

But, curiously, we are most likely to vividly remember experiences we had between the ages of 15 and 25. What the social sciences might simply call “nostalgia” psychologists have termed the “reminiscence bump” and, Hammond argues, it could be the key to why we feel like time speeds up as we get older:

The reminiscence bump involves not only the recall of incidents; we even remember more scenes from the films we saw and the books we read in our late teens and early twenties. … The bump can be broken down even further — the big news events that we remember best tend to have happened earlier in the bump, while our most memorable personal experiences are in the second half.

[…]

The key to the reminiscence bump is novelty. The reason we remember our youth so well is that it is a period where we have more new experiences than in our thirties or forties. It’s a time for firsts — first sexual relationships, first jobs, first travel without parents, first experience of living away from home, the first time we get much real choice over the way we spend our days. Novelty has such a strong impact on memory that even within the bump we remember more from the start of each new experience.

Most fascinating of all, however, is the reason the “reminiscence bump” happens in the first place: Hammond argues that because memory and identity are so closely intertwined, it is in those formative years, when we’re constructing our identity and finding our place in the world, that our memory latches onto particularly vivid details in order to use them later in reinforcing that identity. Interestingly, Hammond points out, people who undergo a major transformation of identity later in life — say, changing careers or coming out — tend to experience a second identity bump, which helps them reconcile and consolidate their new identity.

So what makes us date events more accurately? Hammond sums up the research:

You are most likely to remember the timing of an event if it was distinctive, vivid, personally involving and is a tale you have recounted many times since.

But one of the most enchanting instances of time-warping is what Hammond calls the Holiday Paradox — “the contradictory feeling that a good holiday whizzes by, yet feels long when you look back.” (An “American translation” might term it the Vacation Paradox.) Her explanation of its underlying mechanisms is reminiscent of legendary psychologist Daniel Kahneman’s theory of the clash between the “experiencing self” and the “remembering self”. Hammond explains:

The Holiday Paradox is caused by the fact that we view time in our minds in two very different ways — prospectively and retrospectively. Usually these two perspectives match up, but it is in all the circumstances where we remark on the strangeness of time that they don’t.

[…]

We constantly use both prospective and retrospective estimation to gauge time’s passing. Usually they are in equilibrium, but notable experiences disturb that equilibrium, sometimes dramatically. This is also the reason we never get used to it, and never will. We will continue to perceive time in two ways and continue to be struck by its strangeness every time we go on holiday.

Like the “reminiscence bump,” the Holiday Paradox has to do with the quality and concentration of new experiences, especially in contrast to familiar daily routines. During ordinary life, time appears to pass at a normal pace, and we use markers like the start of the workday, weekends, and bedtime to assess the rhythm of things. But once we go on vacation, the stimulation of new sights, sounds, and experiences injects a disproportionate amount of novelty that causes these two types of time to misalign. The result is a warped perception of time.

Ultimately, this source of great mystery and frustration also holds the promise of great liberation and empowerment. Hammond concludes:

We will never have total control over this extraordinary dimension. Time will warp and confuse and baffle and entertain however much we learn about its capacities. But the more we learn, the more we can shape it to our will and destiny. We can slow it down or speed it up. We can hold on to the past more securely and predict the future more accurately. Mental time-travel is one of the greatest gifts of the mind. It makes us human, and it makes us special.

Time Warped, a fine addition to these essential reads on time, goes on to explore such philosophically intriguing and practically useful questions as how our internal clocks dictate our lives, what the optimal pace of productivity might be, and why inhabiting life with presence is the only real way to master time. Pair it with this remarkable visual history of humanity’s depictions of time.

Vedolizumab as Induction and Maintenance Therapy for Crohn’s Disease.


BACKGROUND

The efficacy of vedolizumab, an α4β7 integrin antibody, in Crohn’s disease is unknown.

METHODS

In an integrated study with separate induction and maintenance trials, we assessed intravenous vedolizumab therapy (300 mg) in adults with active Crohn’s disease. In the induction trial, 368 patients were randomly assigned to receive vedolizumab or placebo at weeks 0 and 2 (cohort 1), and 747 patients received open-label vedolizumab at weeks 0 and 2 (cohort 2); disease status was assessed at week 6. In the maintenance trial, 461 patients who had had a response to vedolizumab were randomly assigned to receive placebo or vedolizumab every 8 or 4 weeks until week 52.

RESULTS

At week 6, a total of 14.5% of the patients in cohort 1 who received vedolizumab and 6.8% who received placebo were in clinical remission (i.e., had a score on the Crohn’s Disease Activity Index [CDAI] of ≤150, with scores ranging from 0 to approximately 600 and higher scores indicating greater disease activity) (P=0.02); a total of 31.4% and 25.7% of the patients, respectively, had a CDAI-100 response (≥100-point decrease in the CDAI score) (P=0.23). Among patients in cohorts 1 and 2 who had a response to induction therapy, 39.0% and 36.4% of those assigned to vedolizumab every 8 weeks and every 4 weeks, respectively, were in clinical remission at week 52, as compared with 21.6% assigned to placebo (P<0.001 and P=0.004 for the two vedolizumab groups, respectively, vs. placebo). Antibodies against vedolizumab developed in 4.0% of the patients. Nasopharyngitis occurred more frequently, and headache and abdominal pain less frequently, in patients receiving vedolizumab than in patients receiving placebo. Vedolizumab, as compared with placebo, was associated with a higher rate of serious adverse events (24.4% vs. 15.3%), infections (44.1% vs. 40.2%), and serious infections (5.5% vs. 3.0%).

CONCLUSIONS

Vedolizumab-treated patients with active Crohn’s disease were more likely than patients receiving placebo to have a remission, but not a CDAI-100 response, at week 6; patients with a response to induction therapy who continued to receive vedolizumab (rather than switching to placebo) were more likely to be in remission at week 52. Adverse events were more common with vedolizumab.

Source: NEJM

Hepatitis C Drug Sofosbuvir Still Effective at 24 Weeks.


New data from 4 phase 3 trials with the hepatitis C (HCV) drug sofosbuvir (SOF) and ribavirin (RBV) show that a 12-week regimen is effective in treating HCV genotypes 1 through 6. Twenty-four-week sustained virologic response (SVR) is essentially identical to 12-week SVR, bolstering confidence that the drug combination represents a cure. Those with genotype 3 infections are better served with a 16-week course of treatment.

The new work extends the results of the studies out to 24 weeks after treatment cessation. Twenty-four weeks was the traditional milestone for HCV treatments, but in recent years, the US Food and Drug Administration and industry have gravitated toward the 12-week time point. However, with new drugs set to greatly affect HCV treatment, it is important to consider this older benchmark, according to Kris Kowdley, MD, director of the Liver Center of Excellence at the Digestive Disease Institute at the Virginia Mason Medical Center in Seattle, Washington, who presented the research here at the American College of Gastroenterology (ACG) 2013 Annual Scientific Meeting and Postgraduate Course.

“We’re in a brave new world of hepatitis C treatments, and we’re very quickly reaching all oral, interferon-free, short-duration regimens, so I think it remains valuable to continue following patients to 24 weeks, and possibly 48 weeks, posttreatment to see if the assumption [of a cure] really holds up. We can also learn more about late relapses and possible questions about resistance,” Dr. Kowdley told Medscape Medical News.

The research drew from 4 phase 3 studies: Sofosbuvir With Peginterferon Alfa 2a and Ribavirin for 12 Weeks in Treatment-Naive Subjects With Chronic Genotype 1, 4, 5, or 6 HCV Infection (NEUTRINO), which enrolled treatment-naive patients with genotype (GT) 1, 4, 5, and 6 infection, each of whom received 12 weeks of SOF, peg-interferon (PEG), and ribavirin (RBV); Phase 3 Study of Sofosbuvir and Ribavirin (FISSION), which enrolled treatment-naive GT 2/3 patients to receive either 12 weeks of SOF+RBV or 24 weeks of PEG+RBV; GS-7977 + Ribavirin for 12 Weeks in Subjects With Chronic Genotype 2 or 3 HCV Infection Who Are Interferon Intolerant, Interferon Ineligible or Unwilling to Take Interferon (POSITRON), which enrolled GT 2/3 patients unable or unwilling to receive interferon, who were randomly assigned to receive 12 weeks of SOF+RBV or placebo; and Sofosbuvir + Ribavirin for 12 or 16 Weeks in Treatment Experienced Subjects With Chronic Genotype 2 or 3 HCV Infection (FUSION), which enrolled treatment-experienced GT2/3 patients who received 12 or 16 weeks of SOF+RBV.

For all studies, the primary end point was sustained virologic response (HCV RNA < 25 IU/mL) at 12 weeks posttreatment (SVR12).

In the studies, participants had a mean age of 53 years (range, 19 – 77 years) and a mean body mass index of 28 kg/m2 (range, 17 – 56 kg/m2). Demographics were consistent with those of the HCV-infected population in the United States. Six percent of the participants were receiving opioid replacement therapy.

Table 1. 12-Week SVR Rates

GT 1,4,5,6 GT 2 and 3
NEUTRINO FISSION POSITRON FUSION
SOF/PEG/RBV (n = 327) SOF/RBV (n = 253) PEG/RBV (n = 243) SOF/RBV (n = 207) Placebo (n = 71) SOF/RBV 12 week (n = 100) SOF/RBV 16 week (n = 95)
Overall 91% 67% 67% 78% 0% 50% 73%
GT 2 N/A 97% 78% 93% 0% 86% 94%
GT 3 N/A 56% 63% 61% 0% 30% 62%
Noncirrhotic 93% 72% 74% 81% 0% 61% 76%
Cirrhotic 80% 47% 38% 61% 0% 31% 66%

Compensated cirrhosis at baseline was found in 17% of patients in the NEUTRINO study, 21% in FISSION, 18% in POSITRON, and 33% in FUSION.

In all studies, SVR12 was higher in patients without cirrhosis. Patients with GT 2 experienced higher SVR12 rates than those with GT 3.

SVR 24 rates were similar to SVR 12 rates.

Table 2. SVR12 vs SVR24

SVR12 SVR24
Treatment-naïve patients
GT 1, 4, 5, 6 overall 91% 91%
GT 1 90% 90%
GT 4 96% 96%
GT 5 and GT 6 100% 100%
Treatment-naive and experienced GT 2, 3 patients
Treatment-naive 67% 67%
Interferon unable 78% 78%
Previously treated (12 week regimen) 51% 50%
Previously treated (16 week regimen) 73% 72%

The additional data back up the 12-week SVR. “In all the studies, the 24-week results are almost identical [to the 12-week SVR]. We detected durability of that response,” said Dr. Kowdley. The studies also suggest that interferon is not needed to achieve SVR in genotypes 2 and 3, although Dr. Kowdley said that trials of interferon-sparing regimens are underway.

The results further underscore the anticipation that physicians have toward sofosbuvir and other new drugs. “I think 2 years ago there was a standing-room only meeting in San Francisco, where Pharmasset (which originally developed sofosbuvir), dropped just unbelievable results, and we all thought this was too good to be true,” Tim Little, MD, a physician with Puget Sound Gastroenterology in Seattle, Washington, who attended the presentation, told Medscape Medical News.

“I don’t know that there’s anything incredibly new about (this study), but it’s confirmation that this dramatic result that this very small group of investigators presented is actually real, and I think we can all understand that this is as good as they said it was going to be, or almost as good,” Dr. Little said.

On October 25, an FDA advisory committee unanimously recommended approval of sofosbuvir based on the 12-week results. The FDA is expected to make a decision by December 8.

Source: American College of Gastroenterology (ACG)

Healthy Diet, Healthy Aging.


Middle-aged women following a healthy Mediterranean-type diet — with an emphasis on fruits, vegetables, whole grains and fish, moderate amounts of alcohol, and little red meat — have much greater odds of healthy aging later on, a new study reports.

“In this study, women with healthier dietary patterns at midlife were 40% more likely to survive to age 70 or over free of major chronic diseases and with no impairment in physical function, cognition or mental health,” said lead study author, Cécilia Samieri, PhD, Institut pour la Santé Publique et le Developpement, Université Bordeaux, France.

This new study adds to growing research on the health benefits of the Mediterranean diet recently reported. Various studies have shown that this diet may contribute to reduced fasting glucose concentrations and lipid levels in those at risk for diabetes, may lower the risk for cardiovascular events and stroke, and improve cognition.

The new study was published in the November 5 issue of Annals of Internal Medicine.

The analysis included 10,670 participants in the Nurses’ Health Study, which began in 1976 when female nurses aged 30 to 55 years completed a mail-in survey. Since then, study participants have been closely followed on a regular basis.

In 1980, participants completed a food-frequency questionnaire (FFQ) that asked how often on average they consumed standard portions of various foods. This questionnaire was repeated in 1984 and 1986 and then every 4 years.

To assess dietary quality at midlife, researchers averaged information from the 1984 and 1986 FFQs. They calculated scores on 2 diet indexes:

  • Alternative Healthy Eating Index-2010 (AHEI-2010): This index considers greater intake of vegetables, fruits, whole grains, nuts, legumes, and polyunsaturated fatty acids (PUFAs); lower intake of sugar-sweetened beverages, red or processed meats, trans fats, and sodium; and moderate intake of alcoholic beverages. Total AHEI-2010 scores range from 0 (nonadherence) to 110 (perfect adherence).

  • Alternate Mediterranean diet (A-MeDi): Developed to assess adherence to the traditional Mediterranean diet, this index includes 9 components that are similar to those in the AHEI-2010. Total A-MeDi scores range from 0 (nonadherence) to 9 (perfect adherence).

In 1992, 1996, and 2000, participants completed the Medical Outcomes Short-Form 36 Health Survey, a questionnaire that evaluates 8 health concepts, including mental health and physical functioning. Scores from the Telephone Interview for Cognitive Status, an adaptation of the Mini-Mental State Examination, were used to evaluate cognitive health. From 1995 to 2001, a cognitive study was administered to participants aged 70 years or older.

Investigators separated “healthy” from “usual” aging on the basis of 4 health domains. Overall, 11.0% of the participants were considered healthy (and so were free of chronic diseases, such as cancers, myocardial infarction, and diabetes, and with no limitation in cognitive function, mental health, and physical function), and the remaining participants were considered usual agers.

Several health domains were typically impaired among the “usual” agers, said Dr. Samieri. “For example, 33% had both chronic diseases and limitations in cognitive, physical, or mental health; 64% had only limitations in cognitive, physical, or mental health; and 3.4% had only 1 or more chronic diseases.”

The analysis revealed that greater adherence at midlife to AHEI-2010 and A-MeDi was strongly associated with greater odds of healthy aging (P for trend < .001 for AHEI-2010; P for trend = .002 for A-Medi).

For example, compared with women in the worst quintile of diet scores, women in the highest quintile of the AHEI-2010 and A-MeDi scores had 34% (95% confidence interval [CI], 9% – 66%) and 46% (95% CI, 17% – 83%) greater odds of healthy aging, respectively.

Individual Components

When they analyzed individual dietary components, researchers found statistically significant associations of greater intake of fruits (odds ratio [OR] for upper versus lower quintiles, 1.46) and alcohol (OR, 1.28), and lower intakes of sweetened beverages (OR, 1.28) and PUFAs (OR, 1.38) with healthy aging (P for trend ≤ .04).

The authors noted that they could not exclude participants with impaired cognition, mental health, and physical function in midlife, and although probably few women had severe impairments at baseline, reverse causation in these participants may still be possible. Because they didn’t follow participants through to death or onset of a condition that would classify them as no longer healthy, researchers couldn’t prospectively estimate risks for transitioning from healthy to usual aging. As well, measurement errors may have occurred in the assessment of dietary patterns.

Other possible limitations were that the study was observational and, because it included mostly white women, its results may not be generalizable to other populations.

Middle age is probably the most relevant period of exposure for preventing chronic conditions of aging that develop over many years.

“It’s largely accepted that cumulative exposures to environmental risk factors over the lifespan are probably more important than late-life exposures to determine health in older ages,” said Dr. Samieri. “Several mechanisms of age-related chronic diseases, for example, atherosclerosis in cardiac diseases, brain lesions in dementia, start in midlife.”

Various researchers have reported on other newly documented health benefits of the Mediterranean diet, including the following:

Scientists identify clue to regrowing nerve cells.


Researchers atWashington University School of Medicine in St. Louis have identified a chain reaction that triggers the regrowth of some damaged nerve cell branches, a discovery that one day may help improve treatments for nerve injuries that can cause loss of sensation or paralysis. 

The scientists also showed that nerve cells in the brain and spinal cord are missing a link in this chain reaction. The link, a protein called HDAC5, may help explain why these cells are unlikely to regrow lost branches on their own. The new research suggests that activating HDAC5 in the central nervous system may turn on regeneration of nerve cell branches in this region, where injuries often cause lasting paralysis. 

Nerve cells with branches

“We knew several genes that contribute to the regrowth of these nerve cell branches, which are called axons, but until now we didn’t know what activated the expression of these genes and, hence, the repair process,” said senior author Valeria Cavalli, PhD, assistant professor of neurobiology. “This puts us a step closer to one day being able to develop treatments that enhance axon regrowth.” 

The research appears Nov. 7 in the journal Cell.

Axons are the branches of nerve cells that send messages. They typically are much longer and more vulnerable to injury than dendrites, the branches that receive messages. 

In the peripheral nervous system — the network of nerve cells outside the brain and spinal column — cells sometimes naturally regenerate damaged axons. But in the central nervous system, comprised of the brain and spinal cord, injured nerve cells typically do not replace lost axons. 

Working with peripheral nervous system cells grown in the laboratory, Yongcheol Cho, PhD, a postdoctoral research associate in Cavalli’s laboratory, severed the cells’ axons. He and his colleagues learned that this causes a surge of calcium to travel backward along the axon to the body of the cell. The surge is the first step in a series of reactions that activate axon repair mechanisms. 

In peripheral nerve cells, one of the most important steps in this chain reaction is the release of a protein, HDAC5, from the cell nucleus, the central compartment where DNA is kept. The researchers learned that after leaving the nucleus, HDAC5 turns on a number of genes involved in the regrowth process. HDAC5 also travels to the site of the injury to assist in the creation of microtubules, rigid tubes that act as support structures for the cell and help establish the structure of the replacement axon.

When the researchers genetically modified the HDAC5 gene to keep its protein trapped in the nuclei of peripheral nerve cells, axons did not regenerate in cell cultures. The scientists also showed they could encourage axon regrowth in cell cultures and in animals by dosing the cells with drugs that made it easier for HDAC5 to leave the nucleus.

When the scientists looked for the same chain reaction in central nervous system cells, they found that HDAC5 never left the nuclei of the cells and did not travel to the site of the injury. They believe that failure to get this essential player out of the nucleus may be one of the most important reasons why central nervous system cells do not regenerate axons.

“This gives us the hope that if we can find ways to manipulate this system in brain and spinal cord neurons, we can help the cells of the central nervous system regrow lost branches,” Cavalli said. “We’re working on that now.”

Cavalli also is collaborating with Susan Mackinnon, MD, the Sydney M. Shoenberg Jr. and Robert H. Shoenberg Professor of Surgery, chief of the Division of Plastic and Reconstructive Surgery and a pioneer in peripheral nerve transplants. The two are investigating whether HDAC5 or other components of the chain reaction can be used to help restore sensory functions in nerve grafts.

 

A Smartphone App That Detects Radiation In A Disaster.


GammaPix just got a test run at the catastrophe simulation site Disaster City.

Disaster City is your one-stop for about every catastrophe you can think of. Train derailments, hurricanes, and other unfortunate happenings all get simulated at the Texas A&M site. As part of a test Wednesday, first responders test piloted something new: a smartphone app that detects radiation.

GammaPix, which sounds like one of those weird apps you accidentally find in the App Store and assume doesn’t work, is apparently a real thing for iPhone and Android that “can be used for the detection of radioactivity in everyday life such as exposure on airplanes, from medical patients or from contaminated products.” It works through a smartphone’s camera, so doesn’t require any external attachments. Chips inside of a smartphone’s built-in camera are sensitive to gamma rays; GammaPix uses its software to measure the impact of those rays, and give a picture of radioactivity in the area. The company says it works from up to 100 meters away.

Wednesday, at the Disaster City exercise, first responders measured radiation levels with the app, then practiced sending the data to officials through a wireless network. The idea’s that those officials will be able to make better-informed decisions more quickly with the data. Maybe one day civilians could download the app and be prepared to monitor radioactivity in an emergency, although they probably (hopefully) wouldn’t get much of a chance to use it.