Minor Thoughts from me to you

Archives for Science (page 2 / 3)

High Fat Foods Don’t Appear to Cause High Cholesterol

As I think about losing weight (which I do (think about, that is) from time to time), I’m always interested in what kind of a diet would be most effective. I’m most convinced by what I’ve read about low-carb, high protein, high fat diets. But, inevitably, the first objection I’ll hear is that a diet high in eggs and cheese is a diet that will lead to high cholesterol and heart problems.

Stephen Guyenet recently reviewed the literature. He found that there is very little evidence that diets high in saturated fats give you high cholesterol.

The earliest and perhaps most interesting study I found was published in the British Medical Journal in 1963 and is titled "Diet and Plasma Cholesterol in 99 Bank Men" (4). Investigators asked volunteers to weigh all food consumed at home for 1-2 weeks, and describe in detail all food consumed away from home. Compliance was good. This dietary accounting method was much more thorough than in most observational studies today**. Animal fat intake ranged from 55 to 173 grams per day, and blood cholesterol ranged from 154 to 324 mg/dL, yet there was no relationship whatsoever between the two. I'm looking at a graph of animal fat intake vs. blood cholesterol as I write this, and it looks like someone shot it with a shotgun at 50 yards. They twisted the data every which way, but were never able to squeeze even a hint of an association out of it.

Overall, the literature does not offer much support for the idea that long term saturated fat intake has a significant effect on the concentration of blood cholesterol. If it's a factor at all, it must be rather weak, which is consistent with what has been observed in multiple non-human species (13).

I found another interesting analysis, published last January in the American Journal of Clinical Nutrion. In it, the authors did a meta-analysis of lots of other studies. They also concluded that there is very little relationship between the fat in your diet and the fat (cholestrol) in your blood.

BACKGROUND: A reduction in dietary saturated fat has generally been thought to improve cardiovascular health.

OBJECTIVE: The objective of this meta-analysis was to summarize the evidence related to the association of dietary saturated fat with risk of coronary heart disease (CHD), stroke, and cardiovascular disease (CVD; CHD inclusive of stroke) in prospective epidemiologic studies.

DESIGN: Twenty-one studies identified by searching MEDLINE and EMBASE databases and secondary referencing qualified for inclusion in this study. A random-effects model was used to derive composite relative risk estimates for CHD, stroke, and CVD.

RESULTS: During 5-23 y of follow-up of 347,747 subjects, 11,006 developed CHD or stroke. Intake of saturated fat was not associated with an increased risk of CHD, stroke, or CVD. The pooled relative risk estimates that compared extreme quantiles of saturated fat intake were 1.07 (95% CI: 0.96, 1.19; P = 0.22) for CHD, 0.81 (95% CI: 0.62, 1.05; P = 0.11) for stroke, and 1.00 (95% CI: 0.89, 1.11; P = 0.95) for CVD. Consideration of age, sex, and study quality did not change the results.

CONCLUSIONS: A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.

This entry was tagged. Foods Research

Shyness: Evolutionary Tactic?

Shyness: Evolutionary Tactic? →

An interesting overview of the importance of introverts, the ways in which our society is marginalizing introverts (possibly even describing introversion as a mental disease). We introverts should probably think about this article carefully, to ponder its ramifications. I doubt the extroverts will even see it though.

Once you know about sitters and rovers, you see them everywhere, especially among young children. Drop in on your local Mommy and Me music class: there are the sitters, intently watching the action from their mothers’ laps, while the rovers march around the room banging their drums and shaking their maracas.

Relaxed and exploratory, the rovers have fun, make friends and will take risks, both rewarding and dangerous ones, as they grow. According to Daniel Nettle, a Newcastle University evolutionary psychologist, extroverts are more likely than introverts to be hospitalized as a result of an injury, have affairs (men) and change relationships (women). One study of bus drivers even found that accidents are more likely to occur when extroverts are at the wheel.

In contrast, sitter children are careful and astute, and tend to learn by observing instead of by acting. They notice scary things more than other children do, but they also notice more things in general. Studies dating all the way back to the 1960’s by the psychologists Jerome Kagan and Ellen Siegelman found that cautious, solitary children playing matching games spent more time considering all the alternatives than impulsive children did, actually using more eye movements to make decisions. Recent studies by a group of scientists at Stony Brook University and at Chinese universities using functional M.R.I. technology echoed this research, finding that adults with sitter-like temperaments looked longer at pairs of photos with subtle differences and showed more activity in brain regions that make associations between the photos and other stored information in the brain.

This entry was tagged. Research

A Release Valve for Cyclists’ Unrelenting Pressure

A Release Valve for Cyclists’ Unrelenting Pressure →

Should you get a new bike seat, for the good of your sexual health? As the Blogfather would say, why take chances?

John Tierney, reports.

“I’ve spent much of my journalistic career debunking health scares, but the bike-saddle menace struck me as a no-brainer when I first heard about it. Why, if you had an easy alternative, would you take any risk with that part of the anatomy? Even if you didn’t feel any symptoms, even if you didn’t believe the researchers’ warnings, even if you thought it was perfectly healthy to feel numb during a ride — why not switch just for comfort’s sake? Why go on crushing your crotch?”

Alternative bike seats listed at healthycycling.org.

This entry was tagged. Innovation

Milk Doesn't Make Coughing Worse

Milk Doesn't Make Coughing Worse →

This is good news because milk is my daughter's favorite drink even (especially?) when she's sick. We used to tell her that drinking milk would make her cough worse. Now, we won't have to.

“The question has been formally investigated in studies, which demonstrated no increase in mucus production,” Dr. Sulica said, “although subjects who believed in the phenomenon reported that they did feel more mucus” when they ate dairy products.

The corollary to this finding is that dairy products have no effect on cough, he said.

This entry was tagged. Food

That's How a Dark Age Begins

That's How a Dark Age Begins →

Jeff Greason, President of XCOR Aerospace, talks at TEDx about being a rocket scientist and making space pay — and why he got into commercial space travel in the first place.

"Daddy, is it really true that they used to fly to the moon when you were a boy?" That shook me and it still does. It shook me because that's how a dark age begins. A dark age is not just when you as a civilization have forgotten how to do something. It's when you forget that you ever could.

... We have done fewer than 500 space flights since the 1960s. The Wright Brothers did more than 700 glider test flights, in preparation for their first powered flight. The space age has not yet opened. We are at the very beginnings of it.

I think commercial space travel, research, and development is one of the coolest things to happen in a long, long time. The resources in space are limitless — water, minerals, metals, energy and more. Let's get out there and get it. There's no reason that earth's billions have to remain poor.

I can't wait until I can book a flight on a rocket.

Space Farming

Space Farming →

This is pretty cool. Teams around the world are working on plans for building indoor farms on the moon. These farms would scrub CO2 out of the air, produce about 500 pounds of oxygen a year, and produce food for the astronauts. And, most of it could be run by robots.

This entry was not tagged.

The Problem with Anthropogenic Global Warming

Warren Meyer points out Richard Lindzen's Congressional testimony as a great example of the central problem with global warming models.

Here are two statements that are completely agreed on by the IPCC. It is crucial to be aware of their implications.

  1. A doubling of CO2, by itself, contributes only about 1C to greenhouse warming. All models project more warming, because, within models, there are positive feedbacks from water vapor and clouds, and these feedbacks are considered by the IPCC to be uncertain.

  2. If one assumes all warming over the past century is due to anthropogenic greenhouse forcing, then the derived sensitivity of the climate to a doubling of CO2is less than 1C. The higher sensitivity of existing models is made consistent with observed warming by invoking unknown additional negative forcings from aerosols and solar variability as arbitrary adjustments.

Given the above, the notion that alarming warming is 'settled science' should be offensive to any sentient individual, though to be sure, the above is hardly emphasized by the IPCC. 4

Did you catch that? Even assuming that all of the warming that occurred from 1900-2000 was due to human activities (a very dubious assertion to begin with), the climate still isn't as sensitive to increases in CO2 as the climate models predicate. The climate models have to add in additional fudge factors to get the results that the "scientists" want to see.

Until that changes -- until there is hard evidence that the climate really is that sensitive to increases in CO2 -- I'll continue to oppose any kind of carbon caps, carbon taxes, or any other attempt by the government to control how we generate and use energy.

This entry was tagged. Global Warming

Where Drugs Come From: The Numbers

Derek Lowe has a very interesting post on Where Drugs Come From:

We can now answer the question: "Where do new drugs come from?". Well, we can answer it for the period from 1998 on, at any rate. A new paper in Nature Reviews Drug Discovery takes on all 252 drugs approved by the FDA from then through 2007, and traces each of them back to their origins. What's more, each drug is evaluated by how much unmet medical need it was addressed to and how scientifically innovative it was. Clearly, there's going to be room for some argument in any study of this sort, but I'm very glad to have it, nonetheless. Credit where credit's due: who's been discovering the most drugs, and who's been discovering the best ones?

Spoiler: Overall 58% of all new drugs come from the pharmaceutical companies. BUT, 53% of all drugs for unmet needs came from either biotech companies or universities and 56% of all truly novel drugs came from either biotech companies or universities.

My conclusion: all 3 sources are important parts of the drug innovation system and we shouldn't bash or diminish the importance of any of the 3 sources.

Obamacare delenda est

Plastics from engineered yeast?

We're going to run out of oil someday -- whether it's now or 75 years from now. Plastics are pretty important and we'll need a way to produce them once we run out of oil. Given all of that, how cool is this?

Engineered yeast could produce low-cost plastics from renewable resources:

The researchers engineered C. tropicalis to transform fatty acids into omega-hydroxyfatty acids, a monomer that when polymerized provides a variety of options for developing new bio-based plastics with attractive physical properties. Usually, these acids are difficult and expensive to prepare using traditional methods. The key to getting the yeast to produce large amounts of omega-hydroxyfatty acids was eliminating certain enzymes that further oxidize these acids into unwanted diacids. The researchers identified and eliminated 16 genes and other oxidation pathways, which resulted in a 90% reduction in the activity that converts omega-hydroxyfatty acids to diacids.

As the scientists explained, this new engineered strain of C. tropicalis provides a foundation for the development of low-cost methods of producing omega-hydroxyfatty acids for conversion into plastics. Plastics produced by this method could have a variety of uses, as previous research has shown that plastics produced from a very similar omega-hydroxyfatty acid are strong, ductile materials. The plastics could have applications in lubricants, adhesives, cosmetics, and anti-cancer therapies, and could also be recycled through a conversion process that results in a biofuel similar to biodiesels such as Soy Gold.

Obamacare delenda est

This entry was tagged. Innovation

What Color Were Dinosaurs?

Picture of a colored dinosaur

This is just incredibly cool.

Dr. Prum and his colleagues took advantage of the fact that feathers contain pigment-loaded sacs called melanosomes. In 2009, they demonstrated that melanosomes survived for millions of years in fossil bird feathers. The shape and arrangement of melanosomes help produce the color of feathers, so the scientists were able to get clues about the color of fossil feathers from their melanosomes alone.

[...] Working with paleontologists at the Beijing Museum of Natural History and Peking University, the researchers began to study a 150-million-year-old species called Anchiornis huxleyi. The chicken-sized theropod was festooned with long feathers on its arms and legs.

The researchers removed 29 chips, each the size of a poppy seed, from across the dinosaur’s body. Mr. Vinther put the chips under a microscope and discovered melanosomes.

To figure out the colors of Anchiornis feathers, Mr. Vinther and his colleagues turned to Matthew Shawkey, a University of Akron biologist who has made detailed studies of melanosome patterns in living birds. Dr. Shawkey can accurately predict the color of feathers from melanosomes alone. The scientists used the same method to decipher Anchiornis’s color pattern.

Organic food is just the same only more expensive

Organic food is no healthier, study finds | Science | Reuters

LONDON (Reuters) - Organic food has no nutritional or health benefits over ordinary food, according to a major study published Wednesday.

Researchers from the London School of Hygiene & Tropical Medicine said consumers were paying higher prices for organic food because of its perceived health benefits, creating a global organic market worth an estimated $48 billion in 2007.

A systematic review of 162 scientific papers published in the scientific literature over the last 50 years, however, found there was no significant difference.

"A small number of differences in nutrient content were found to exist between organically and conventionally produced foodstuffs, but these are unlikely to be of any public health relevance," said Alan Dangour, one of the report's authors.

"Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority."

I'm shocked, shocked, to find that out. I'm also laughing at the superior diets of everyone who paid for more for their organic food than I did for my silicon food.

This entry was tagged. Research

The Inscrutable Woman

When it comes to assessing the romantic playing field -- who might be interested in whom -- men and women were shown to be equally good at gauging men's interest during an Indiana University study involving speed dating -- and equally bad at judging women's interest.

"The hardest-to-read women were being misperceived at a much higher rate than the hardest-to-read men. Those women were being flirtatious, but it turned out they weren't interested at all," said lead author Skyler Place, a doctoral student in IU's Department of Psychological and Brain Sciences working with cognitive science Professor Peter Todd. "Nobody could really read what these deceptive females were doing, including other women."

-- from Newswise Social and Behavioral Sciences News | Observers of First Dates Can Predict Outcome

Huh. So guys who complain of being led on aren't just making it up.

This entry was tagged. Dating Research Women

32 Weeks ... And Growing

Why Every Week of Pregnancy Counts - WSJ.com:

A study in the American Journal of Obstetrics and Gynecology in October calculated that for each week a baby stayed in the womb between 32 and 39 weeks, there is a 23% decrease in problems such as respiratory distress, jaundice, seizures, temperature instability and brain hemorrhages.

A study of nearly 15,000 children in the Journal of Pediatrics in July found that those born between 32 and 36 weeks had lower reading and math scores in first grade than babies who went to full term. New research also suggests that late preterm infants are at higher risk for mild cognitive and behavioral problems and may have lower I.Q.s than those who go full term.

What's more, experts warn that a fetus's estimated age may be off by as much as two weeks either way, meaning that a baby thought to be 36 weeks along might be only 34.

The American College of Obstetricians and Gynecologists, the American Academy of Pediatrics and the March of Dimes are now urging obstetricians not to deliver babies before 39 weeks unless there is a medical reason to do so.

This entry was tagged. Research

Increasing Solar Efficiency

Researches keep moving along with solar power advancements. The latest advancement is a new antireflective coating that allows solar panels to absorb more sunlight.

Researchers at Rensselaer Polytechnic Institute have discovered and demonstrated a new method for overcoming two major hurdles facing solar energy. By developing a new antireflective coating that boosts the amount of sunlight captured by solar panels and allows those panels to absorb the entire solar spectrum from nearly any angle, the research team has moved academia and industry closer to realizing high-efficiency, cost-effective solar power.

"To get maximum efficiency when converting solar power into electricity, you want a solar panel that can absorb nearly every single photon of light, regardless of the sun's position in the sky," said Shawn-Yu Lin, professor of physics at Rensselaer and a member of the university's Future Chips Constellation, who led the research project. "Our new antireflective coating makes this possible."

... An untreated silicon solar cell only absorbs 67.4 percent of sunlight shone upon it -- meaning that nearly one-third of that sunlight is reflected away and thus unharvestable. From an economic and efficiency perspective, this unharvested light is wasted potential and a major barrier hampering the proliferation and widespread adoption of solar power.

After a silicon surface was treated with Lin's new nanoengineered reflective coating, however, the material absorbed 96.21 percent of sunlight shone upon it -- meaning that only 3.79 percent of the sunlight was reflected and unharvested. This huge gain in absorption was consistent across the entire spectrum of sunlight, from UV to visible light and infrared, and moves solar power a significant step forward toward economic viability.

That's exciting stuff. Of course, there's a while to go yet before we have solar panels on our houses. The comments on the original article point out some of the remaining issues. For instance, this new coating requires 7 new layers on top of the solar cell. How expensive are these layers? Does the additional energy offset the additional manufacturing cost? What about converting that extra sunlight into electricity? The sunlight isn't necessarily converted into electricity just because it's absorbed by the panel. What about conversion efficiency? Existing panels convert sunlight to electricity at around 30% efficiency. New panels with this coating will collect more light but still convert it with ridiculously low efficiency.

To have a viable solar infrastructure we need panels that can absorb nearly 100% of the incoming sunlight, convert nearly 100% of the incoming sunlight, and convert the sunlight with much better efficiency. More than that, the final panels need to be relatively cheap or no one will be able to buy and use them. We're not there yet. But we are getting closer. And I look forward to the day that I can power a significant portion of my home's energy needs with solar energy.

This entry was tagged. Energy Solar Power

Stop Stretching!

Everything you know about stretching is probably wrong. So say many sports researchers.

When Duane Knudson, a professor of kinesiology at California State University, Chico, looks around campus at athletes warming up before practice, he sees one dangerous mistake after another. "They're stretching, touching their toes. . . . " He sighs. "It's discouraging."

If you're like most of us, you were taught the importance of warm-up exercises back in grade school, and you've likely continued with pretty much the same routine ever since. Science, however, has moved on. Researchers now believe that some of the more entrenched elements of many athletes' warm-up regimens are not only a waste of time but actually bad for you. The old presumption that holding a stretch for 20 to 30 seconds -- known as static stretching -- primes muscles for a workout is dead wrong. It actually weakens them. In a recent study conducted at the University of Nevada, Las Vegas, athletes generated less force from their leg muscles after static stretching than they did after not stretching at all. Other studies have found that this stretching decreases muscle strength by as much as 30 percent. Also, stretching one leg's muscles can reduce strength in the other leg as well, probably because the central nervous system rebels against the movements.

This entry was tagged. Research

Pop an Exercise Pill

I've been wanting to get back into shape. These new pills could be the perfect solution.

In a series of startling experiments in mice, the drugs improved the ability of cells to burn fat and retain muscle mass, and they substantially prolonged endurance during exercise. Using one of the compounds for just a month, even sedentary, couch-potato mice improved their endurance running by a staggering 44%. Some mice that combined a month of exercise with the other drug bolstered their long-distance running by about 70% over untreated mice.

One of the drugs is already in late-stage human trials for other purposes, and the mouse experiments raise hopes for new strategies to protect people against obesity, diabetes and muscle-wasting diseases such as muscular dystrophy.

Anabolic steroids, often abused by athletes, enhance the performance of fast-twitch muscle cells -- those that provide power and speed. The two drugs being researched are among the first compounds shown clearly to improve the slow-twitch muscle cells used in endurance activities. Whereas fast-twitch muscle cells burn sugar, slow-twitch cells primarily burn fat, which means they could help combat obesity.

Now I'm just waiting until I can buy me a 90-day supply.

This entry was tagged. Good News Innovation

Its troubles are over, Guys

Cow at Peace

Test: Can you tell whether this cow was treated well or not?

How much histrionic handwringing about this beef recall do we have to endure? From The New York Times, presumably nicknamed "The Gray Lady" because it's gone senile, writes:

"A nauseating video of cows stumbling on their way to a California slaughterhouse has finally prompted action: the largest recall of meat in American history... A lot of that beef has already been eaten, and so far, thankfully, there have been no reports of illness. But the question Congress needs to ask is how many people need to get sick or die before it starts repairing and modernizing the nation’s food safety system?"

Am I the only one to ask the question of how cows being killed "inhumanely" (and that's really an interesting term to apply to the death of something that isn't human, isn't it?) results in beef that is not fit for consumption? Even if we waterboard the things before putting them through the grinder, their meat is still meat. A stressed cow does not equal a poisonous cow.

Slap a fine on the meatpackers to appease the heifer-huggers and serve 'em up. Send some to my house.

What was God thinking?

Checking Her Out

The Good Lord's reputation for cruelty amidst our world's heathen is in no way improved when scientists make discoveries like this:

"A sexy sway of the hips, long-believed to be a sign [of] seduction from women, actually may mean back off, according to a new study.

"A woman with a sexy walk is unlikely to be ovulating, which is typically when single women seek out male partners, according to a new Canadian study, French news service AFP reports."

Yes, you read that right: a woman is least interested in sex right when her body is performing magic show-worthy feats of hypnosis on male passersby.

On the plus side, say what you want about the misuse of American tax dollars on grants for questionable academic research, but those Canadian professors are earning their public funds.

This entry was tagged. Humor

The Useful Appendix

The function of the appendix seems related to the massive amount of bacteria populating the human digestive system, according to the study in the Journal of Theoretical Biology. There are more bacteria than human cells in the typical body. Most of it is good and helps digest food.

But sometimes the flora of bacteria in the intestines die or are purged. Diseases such as cholera or amoebic dysentery would clear the gut of useful bacteria. The appendix's job is to reboot the digestive system in that case.

The appendix "acts as a good safe house for bacteria," said Duke surgery professor Bill Parker, a study co-author. Its location -- just below the normal one-way flow of food and germs in the large intestine in a sort of gut cul-de-sac -- helps support the theory, he said.

Also, the worm-shaped organ outgrowth acts like a bacteria factory, cultivating the good germs, Parker said.

That use is not needed in a modern industrialized society, Parker said. If a person's gut flora dies, they can usually repopulate it easily with germs they pick up from other people, he said. But before dense populations in modern times and during epidemics of cholera that affected a whole region, it wasn't as easy to grow back that bacteria and the appendix came in handy.

In less developed countries, where the appendix may be still useful, the rate of appendicitis is lower than in the U.S., other studies have shown, Parker said.

He said the appendix may be another case of an overly hygienic society triggering an overreaction by the body's immune system.

This entry was not tagged.