Currently browsing the Life Science Category

Posts covering topics such as: biology, genetics, viruses, health care...
Recommended posts: Complete Work of Charles Darwin Online - The Inner Life of a Cell - Feed your Newborn Neurons - New Understanding of Human DNA - Bye Bye Bees - Energy Efficiency of Digestion - Microbe Types

Europe Bans Certain Pesticides, USA Just Keeps Looking, Bees Keep Dying

For years the bee colony collapse disorder has been showing the difficulty of the scientific inquiry process. And that difficulty often becomes more difficult if interests with lots of money at stake want to block certain conclusions.

One-Third of U.S. Honeybee Colonies Died Last Winter, Threatening Food Supply

Multiple factors — pesticides, fungicides, parasites, viruses and malnutrition — are believed to cause the losses, which were officially announced today by a consortium of academic researchers, beekeepers and Department of Agriculture scientists.

“We’re getting closer and closer to the point where we don’t have enough bees in this country to meet pollination demands,” said entomologist Dennis vanEngelstorp of the University of Maryland, who led the survey documenting the declines.

Beekeepers lost 31 percent of their colonies in late 2012 and early 2013, roughly double what’s considered acceptable attrition through natural causes. The losses are in keeping with rates documented since 2006, when beekeeper concerns prompted the first nationwide survey of honeybee health. Hopes raised by drop in rates of loss to 22 percent in 2011-2012 were wiped out by the new numbers.

Most losses reported in the latest survey, however, don’t actually fit the CCD profile. And though CCD is largely undocumented in western Europe, honeybee losses there have also been dramatic. In fact, CCD seems to be declining, even as total losses mount. The honeybees are simply dying.

“Even if CCD went away, we’d still have tremendous losses,” said entomologist Diana Cox-Foster at Pennsylvania State University. “CCD losses are like the straw that breaks the camel’s back. The system has many other issues.”

Continue reading

Can You Effectively Burn Calories by Drinking Cold Water?

Neil deGrasse Tyson stated on Twitter:

Wanna lose 1200 Calories a month? Drink a liter of ice water a day. You burn the energy just raising the water to body temp.

What if your body is trying to cool down? I would imagine we have to use energy to cool off (though I am no expert on this)? So if you drink cold water and your body has less need to cool off, couldn’t this actually end up “saving” your body needing to burn calories – and thus cause yourself to gain weight?

This model would be similar to a server room that was cooled with air conditioning and cold winter air to cool off the servers. If there was less cold air used then more electricity would be used running the air conditioner to cool down the servers. I don’t know if it is a decent analogy though – maybe that isn’t an usable model for how we cool off.

I know we cool off partially by pushing water out onto the exterior of our skin to have it evaporate and cool us off. I would think that takes energy to do.

I do get that it takes energy to raise the temperature of the water you consume. It does make sense to me that if you were cold (like say I was during the winter living in the house I grew up in) you would use energy raising the temperature of the water.

What the overall energy situation is if your body needs to cool down seems questionable to me. Please let me know your thoughts. In any event his statement is accurate. It is just that the implication may lead people astray; that you can consume 1,200 Calories extra to balance the 1,200 Calories drinking cold water uses (or loss weight by having reduced your excess Calories by 1,200 if you eat exactly the same things you would without the cold water).

Related: Why is it Colder at Higher Elevations?Does Diet Soda Result in Weight Gain?Why Does Hair Turn Grey as We Age?How Corn Syrup Might Be Making Us FatWhy Wasn’t the Earth Covered in Ice 4 Billion Years Ago (When the Sun was Dimmer)

Cell Aging and Limits Due to Telomeres

When cells divide the process fails to copy DNA all the way to the end. Telomeres are are the end of DNA strands, as essentially a buffer of material that won’t cause information to be lost when part of the telomere isn’t copied. As DNA is copied, as new cells are created, the length of telomeres at the end is reduced. Once the telomeres are gone the cell will no longer divide.

The 2009 Nobel Prize in Physiology or Medicine went to 3 scientists for discovering how the chromosomes can be copied in a complete way during cell divisions and how they are protected against degradation. The Nobel Laureates have shown that the solution is to be found in the ends of the chromosomes – the telomeres – and in an enzyme that forms them – telomerase.

There is some debate over the benefit of the mechanism of cells not dividing do to lack of telomere. This can prevent cancerous cells from replicating (once they replicate to the extent that the necessary telomere buffer is gone). It is also seen that as telomeres get shorter the cells become more likely to become cancerous.

Cancer also can stimulate the production of telomerase which can stop telomeres from getting shorter as cells divide and thus allow the cancer cells to keep dividing (thus producing more cancer cell and increasing the amount of cancerous cells). Using telomerase to allow health cells to avoid the limits of division is being researched.

Are Telomeres the Key to Aging and Cancer? (University of Utah)

An enzyme named telomerase adds bases to the ends of telomeres. In young cells, telomerase keeps telomeres from wearing down too much. But as cells divide repeatedly, there is not enough telomerase, so the telomeres grow shorter and the cells age.

Cells normally can divide only about 50 to 70 times, with telomeres getting progressively shorter until the cells become senescent, die or sustain genetic damage that can cause cancer.

shorter telomeres are associated with shorter lives. Among people older than 60, those with shorter telomeres were three times more likely to die from heart disease and eight times more likely to die from infectious disease.

While telomere shortening has been linked to the aging process, it is not yet known whether shorter telomeres are just a sign of aging – like gray hair – or actually contribute to aging.

Related: The Naked Mole Rat is the Only Known Cancerless AnimalWebcast of a T-cell Killing a Cancerous CellRNA interference webcast

Huge Human Population Boom 40,000 to 50,000 Years Ago

Interesting open access paper on looking at the Y-chromosome to explore our ancestry: A calibrated human Y-chromosomal phylogeny based on resequencing. I can’t understand all the details but the basic idea isn’t that complicated. It is interesting to see these details as are the conclusions that can be drawn: that we had a big explosion of human population o 41,000–52,000 years ago.

This population explosion occurred, between the first expansion of modern humans out of Africa 60,000 to 70,000 years ago and the Neolithic expansions of people in several parts of the world starting 10,000 years ago.

“We think this second, previously unknown population boom, may have occurred as humans adapted to their new environment after the first out-of-Africa expansion,” says Dr Qasim Ayub, lead author from the Wellcome Trust Sanger institute. “We think that when humans moved from the horn of Africa to Asia, Australia and eventually Europe, they remained in small groups by the coasts. It took them tens of thousands of years to adapt to the mountainous, forested surroundings on the inner continents. However, once their genetic makeup was suited to these new environments, the population increased extremely rapidly as the groups travelled inland and took advantage of the abundance of space and food.”

The work highlights how it is now possible to obtain new biological insights from existing DNA sequencing data sets, and the value of sharing data. The majority of the DNA information used for this study was obtained from freely-available online data-sets.

This is the first time researchers have used the information from large-scale DNA sequencing to create an accurate family tree of the Y chromosome, from which the inferences about human population history could be made.

Full press release

Related: Laser Tool Creates “blueprints” of Archeology SitesHHMI on Science 2.0: Information RevolutionScientists crack 40-year-old DNA puzzle

CDC Again Stresses Urgent Need to Adjust Practices or Pay a Steep Price

Untreatable and hard-to-treat infections from Carbapenem-resistant Enterobacteriaceae (CRE) germs are on the rise among patients in medical facilities. CRE germs have become resistant to all or nearly all the antibiotics we have today. Types of CRE include Klebsiella pneumoniae Carbapenemase (KPC) and New Delhi metallo-beta-lactamase (NDM). By following the United States Center for Disease Control (CDC) guidelines, we can slow the penetration of CRE infections in hospitals and other medical facilities and potentially spread to otherwise healthy people outside of medical facilities.

The CDC has worked with hospitals to successfully apply these measures. The CDC worked with Florida to stop a year-long CRE outbreak in a long-term acute care hospital. With the improved use of CDC recommendations (such as educating staff; dedicating staff, rooms, and equipment to patients with CRE; and improving use of gloves and gowns) the percentage of patients who got CRE at the facility dropped from 44% to 0.

One travesty has been how poorly health care professionals have been about prescribe antibiotics wisely We need to improve and follow CDC antibiotics guidelines (stop the overuse of antibiotics) and use culture results (for patients undergoing treatment) to modify prescriptions, if needed. Antibiotic overuse contributes to the growing problems of Clostridium difficile (c-diff) infection and antibiotic resistance in healthcare facilities. Studies indicate that nearly 50% of antimicrobial use in hospitals is unnecessary or inappropriate (per CDC web site).

Israel decreased CRE infection rates in all 27 of its hospitals by more than 70% in one year with a coordinated prevention program. The USA is at a critical time in which CRE infections could be controlled if addressed in a rapid, coordinated, and consistent effort by doctors, nurses, lab staff, medical facility leadership, health departments/states, policy makers, and the federal government.

As I have been saying for years the damage we are creating due to our actions around the use and abuse of antibiotics is likely to kill tens of thousands, or more people. Because the deaths are delayed and often not dramatic we have continued dangerous practices for years when we know better. It is a shame we are condemning so many to increased risks. The CDC, and others, are doing good work, unfortunately too much bad work is continuing in the face of evidence of how dangerous that is.

Related: CDC Urges Increased Effort to Reduce Drug-Resistant Infections (2006)Key scientific articles on Healthcare Associated Infections via CDCOur Dangerous Antibiotic Practices Carry Great RisksDangerous Drug-Resistant Strains of TB are a Growing Threat

People are Superorganisms With Microbiomes of Thousands of Species

In a recent article in National Geographic Carl Zimmer has again done a good job of explaining the complex interaction between our bodies and the bacteria and microbes that make us sick, and keep us healthy.

The damage done by our indiscriminate use of antibiotics is not just the long term resistance that we create in bacteria (making the future more dangerous for people) that I have written about numerous times but it also endangers the person taking the anti-biotics in the short term. Sometimes the other damage is a tradeoff that should be accepted. But far too often we ignore the damage taking antibiotics too often does.

When You Swallow A Grenade

While antibiotics can discriminate between us and them, however, they can’t discriminate between them and them–between the bacteria that are making us sick and then ones we carry when we’re healthy. When we take a pill of vancomycin, it’s like swallowing a grenade. It may kill our enemy, but it kills a lot of bystanders, too.

If you think of the human genome as all the genes it takes to run a human body, the 20,000 protein-coding genes found in our own DNA are not enough. We are a superorganism that deploys as many as 20 million genes.

Before he started taking antibiotics, the scientists identified 41 species in a stool sample. By day 11, they only found 13. Six weeks after the antibiotics, the man was back up to 38 species. But the species he carried six weeks after the antibiotics did not represent that same kind of diversity he had before he took them. A number of major groups of bacteria were still missing.

They found that children who took antibiotics were at greater risk of developing inflammatory bowel disease later in life. The more antibiotics they took, the greater the risk. Similar studies have found a potential link to asthma as well.

The human body contains trillions of microorganisms — outnumbering human cells by 10 to 1. Because of their small size, however, microorganisms make up only about 1% to 3% of the body’s mass, but play a vital role in human health.

Where doctors had previously isolated only a few hundred bacterial species from the body, Human Microbiome Project (HMP) researchers now calculate that more than 10,000 microbial species occupy the human ecosystem. Moreover, researchers calculate that they have identified between 81% and 99% of all microorganismal genera in healthy adults.

“Humans don’t have all the enzymes we need to digest our own diet,” said Lita Proctor, Ph.D., NHGRI’s HMP program manager. “Microbes in the gut break down many of the proteins, lipids and carbohydrates in our diet into nutrients that we can then absorb. Moreover, the microbes produce beneficial compounds, like vitamins and anti-inflammatories that our genome cannot produce.” Anti-inflammatories are compounds that regulate some of the immune system’s response to disease, such as swelling.

“Enabling disease-specific studies is the whole point of the Human Microbiome Project,” said Barbara Methé, Ph.D., of the J. Craig Venter Institute, Rockville, MD, and lead co-author of the Nature paper on the framework for current and future human microbiome research. “Now that we understand what the normal human microbiome looks like, we should be able to understand how changes in the microbiome are associated with, or even cause, illnesses.”

Read the full NIH press release on the normal bacterial makeup of the body

Related: Tracking the Ecosystem Within UsWhat Happens If the Overuse of Antibiotics Leads to Them No Longer Working?Antibacterial Products May Do More Harm Than GoodAntibiotics Too Often Prescribed for Sinus Woes

Human Gene Origins: 37% Bacterial, 35% Animal, 28% Eukaryotic

The percent of human genes that emerged in various stages of evolution: 37% bacterial, 28% eukaryotic, 16% animal, 13% vertebrate, 6% primate. The history that brought us to where we are is amazing. Eukaryotes include animals, plants, amoebae, flagellates, amoeboflagellates, fungi and plastids (including algae). So eukaryotic genes are those common to us and other non-animal eukaryotes while those classified as animal genes are shared by animals but not non-animal eukaryotes.

We are living in a bacterial world, and it’s impacting us more than previously thought by Lisa Zyga

Bacterial signaling is not only essential for development, it also helps animals maintain homeostasis, keeping us healthy and happy. As research has shown, bacteria in the gut can communicate with the brain through the central nervous system. Studies have found that mice without certain bacteria have defects in brain regions that control anxiety and depression-like behavior. Bacterial signaling also plays an essential role in guarding an animal’s immune system. Disturbing these bacterial signaling pathways can lead to diseases such as diabetes, inflammatory bowel disease, and infections. Studies also suggest that many of the pathogens that cause disease in animals have “hijacked” these bacterial communication channels that originally evolved to maintain a balance between the animal and hundreds of beneficial bacterial species.

Scientists have also discovered that bacteria in the human gut adapts to changing diets. For example, most Americans have a gut microbiome that is optimized for digesting a high-fat, high-protein diet, while people in rural Amazonas, Venezuela, have gut microbes better suited for breaking down complex carbohydrates. Some people in Japan even have a gut bacterium that can digest seaweed. Researchers think the gut microbiome adapts in two ways: by adding or removing certain bacteria species, and by transferring the desired genes from one bacterium to another through horizontal gene transfer. Both host and bacteria benefit from this kind of symbiotic relationship, which researchers think is much more widespread than previously thought.

We want badly for the message in ‘Animals in a bacterial world,’ to be a call for the necessary disappearance of the old boundaries between life science departments (e.g., Depts of Zoology, Botany, Microbiology, etc.) in universities, and societies (e.g., the American Society for Microbiology, etc.). We also want the message disseminated in college and university classes from introductory biology to advanced courses in the various topic areas of our paper.”

Very cool stuff. This amazing facts scientists discover provide an amazing view of the world we live in and how interconnected we are to other life forms in ways we don’t normally think of.

Related: People’s Bodies Carry More Bacterial Cells than Human CellsMicrobes Flourish In Healthy PeopleTracking the Ecosystem Within UsForeign Cells Outnumber Human Cells in Our BodiesBacteria Beneficial to Human Health

How Corn Syrup Might Be Making Us Fat

How Corn Syrup Might Be Making Us Hungry–and Fat by Katherine Harmon

…Glucose lowered the activity of the hypothalamus but fructose actually prompted a small spike to this area. As might be expected from these results, the glucose drink alone increased the feelings of fullness reported by volunteers, which indicates that they would be less likely to consume more calories after having something sweetened with glucose than something sweetened with more fructose.

Fructose and glucose look similar molecularly, but fructose is metabolized differently by the body and prompts the body to secrete less insulin than does glucose (insulin plays a role in telling the body to feel full and in dulling the reward the body gets from food). Fructose also fails to reduce the amount of circulating ghrelin (a hunger-signaling hormone) as much as glucose does. (Animal studies have shown that fructose can, indeed, cross the blood-brain barrier and be metabolized in the hypothalamus.) Previous studies have shown that this effect was pronounced in animal models…

Most of the science indicates calories consumed is by far the dominant factor in weight gain. Different foods with the same calories can affect how hungry you feel. Thus the biggest factor in reducing weight gain seems to be reducing calories and one way to help is to eat food that leaves you feeling full and avoid foods that don’t.

The science is not completely clear though on whether certain diets can have a significant affect above and beyond calorie levels. I am skeptical of such claims, however. There are concerns beyond calories for healthy eating – getting a well balanced diet is important.

Healthy physical activity is also important. Burning off calories with exercise allows more consumption without weight gain. And exercise is important for health not just to avoid gaining weight.

Related: Researchers Find High-Fructose Corn Syrup Results in More Weight GainDoes Drinking Diet Soda Result in Weight Gain?Waste from Gut Bacteria Helps Host Control WeightModeling Weight Loss Over the Long TermHow Caffeine Affects Your Body

Drug Company Funding Taints Published Medical Research

Science provide the opportunity for us to achieve great benefits for society. However, especially in medical research money can make what are already very difficult judgments even less reliable. Add that to a very poor understanding of science in those we elect and you have a dangerous combination. That combination is one of the largest risks we face and need to manage better. I wish we would elect people with a less pitiful appreciation for science but that doesn’t seem likely. That makes doing a better job of managing the conflicts of interest money puts into our current medical research a top priority.

How Drug Company Money Is Undermining Science by Charles Seife

In the past few years the pharmaceutical industry has come up with many ways to funnel large sums of money—enough sometimes to put a child through college—into the pockets of independent medical researchers who are doing work that bears, directly or indirectly, on the drugs these firms are making and marketing. The problem is not just with the drug companies and the researchers but with the whole system—the granting institutions, the research labs, the journals, the professional societies, and so forth. No one is providing the checks and balances necessary to avoid conflicts.

Peer-reviewed journals are littered with studies showing how drug industry money is subtly undermining scientific objectivity. A 2009 study in Cancer showed that participants somehow survived longer when a study’s authors had conflicts of interest than when the authors were clean. A 1998 study in the New England Journal of Medicine found a “strong association” between researchers’ conclusions about the safety of calcium channel blockers, a class of drugs used to reduce blood pressure, and their financial relationships with the firms producing the drugs.

Most of those in the system have an interest in minimizing an effort to clean this up. It is just more work they don’t want to do. Or it goes directly against their interest (drug companies that want to achieve favorable opinions by buying influence). The main political message in the USA for a couple decades has been to reduce regulation. Allowing research that is tainted because you find regulation politically undesirable is a bad idea. People that understand science and how complex medical research is appreciate this.

Sadly when we elect people that by and large are scientifically illiterate they don’t understand the risks of the dangerous practices they allow. Even if they were scientifically illiterate but understood their ignorance they could do a decent job by getting scientific consultation from experts but they don’t (to an extent they listen to the scientists that those that give them lots of money tell them to which does help make sure those giving the politicians cash have their interests served but it is not a good way to create policy with the necessary scientific thinking needed today).

Related: Problems with the Existing Funding System for Medical ResearchMedical Study Integrity (or Lack Thereof)Merck and Elsevier Publish Phony Peer-Review JournalAnti-Science PoliticsStand with Science, Late is Better than Never

Parrots Given “Names” by Their Parents and Use Them Throughout Their Lives

Parrots learn their ‘names’ from their parents

Parrots, which have long amused us for their ability to imitate our vocal patterns, actually learn to caw their “names” from their parents, says a new Cornell study. The research offers the first evidence that parrots learn their unique signature calls from their parents and shows that vocal signaling in wild parrots is a socially acquired rather than a genetically wired trait.

Previous research had shown that all wild parrots use unique “contact calls” that not only distinguish each bird individually, but also communicate their gender, and the mate and larger group they belong to.

“Parrots can have extremely long periods [leading up] to independence, and this is thought to be related to their large brains,” explained Berg. The same goes for primates, he said, with humans in particular being “off the charts” when it comes to a lengthy stage of child dependence.

More research is required, to better understand the evolution of and interaction between these physical and behavioral traits, he said. “We still don’t have good explanations of how these behaviors help wild individuals survive and reproduce in nature,” he said.

The paper offers some possible explanations: Perhaps the parrots’ far-ranging journeys to “communal foraging sights” are what impress upon each parent the need to have their fledglings’ names sorted out — not unlike human parents’ need to call for their children by name at a crowded fair.

I enjoy learning more fun and cool stuff about the animals we share the world with. They are quite an interesting bunch of creatures.

Related: Crow Using a Sequence of Three ToolsFriday Fun: Crow Sledding, Flying Back Up and Sledding Down AgainBackyard Wildlife: HawkFriday Fun: Dancing Parrot

How Caffeine Affects Your Body

From the video by Alex Dainis: Caffeine prevents adenosine from slowing down your nervous system, by binding to the same receptors adenosine would. Caffeine also stimulates the production of adrenaline. And it increases the amount of dopamine present. The average half life of caffeine in the human body is about 6 hours.

Related: Does Diet Soda Result in Weight Gain?Mental Pick-Me-Ups: The Coming BoomRitalin Doesn’t Show Long Term Effectiveness for ADHD

I have been curious about the caffeine content of various drinks and writing this post is a good enough reason to actually look it up.

  • expresso (2oz) 100 mg (varies – 60 mg to 180 mg)
  • coffee (8oz) 100 mg – this can vary quite a bit, 50 to over 100 mg is common. Brewed coffee has more caffeine 100-200 mg.
  • Red Bull (8.2 oz) 80 mg
  • tea (8oz) 20 to 80 mg (depending on strength and type, can also be higher, green tea is on the lower end)
  • Mountain Dew (12 oz) 54 mg (diet has 54 mg also)
  • Diet Coke 46 mg (regular Coke 34mg)
  • Pepsi 38 mg, Diet Pepsi 36 mg

Sprite, 7Up and some root beers have no caffeine.
Chocolate can also be a significant source of caffeine – dark chocolate can have over 80 mg per 100 g (approximately 4 ounces).

  • Recent Comments:

    • rizky indra: is this bad ??? what will happen to earth if the plasma reach here
    • Brian: A lot of younger kids seem to have a uncanny ability to learn things faster and faster. A lot of...
    • here: I wonder how many people a year would be saved from certain types of cancer if they just ate better...
    • himanshu: I would like to question now a days it has been seen that teenagers are having some white hairs...
    • Can: I totally agree with you. I had research position in one of the top European public R&D centers in...
    • Bhatti: Very nice information about this.. first time i am reading about rubber tree.. keep it up..
    • Nick: I agree with Guy. The pharma co’s have to be disassembled and maybe one day we will be treating...
    • Felipe Porto Alegre: Brazil really tried to defend it’s ground on the rubber battlefield, but Malay...
  • Recent Trackbacks:

  • Links