Archive for August, 2012

No Virus to Blame for New AIDS-Like Disease—It’s an Autoimmune Response

By Sophie Bushwick | August 24, 2012 1:11 pm

Mycobacterium abscessus
Signs of infection with Mycobacterium abcessus, which
primarily attacks those with suppressed immune systems

In 2004, medical researchers began noticing cases where patients, primarily middle-aged Asians, sought treatment for frequent opportunistic infections. Developing these infections, which mainly affect people with compromised immune systems, is a key sign of AIDS, and yet these patients test negative for HIV, the AIDS virus.

According to a new study published in the New England Journal of Medicine, an autoimmune response—when your immune system attacks your own body—triggers the immunodeficiency. But we still don’t know why the autoimmune response develops abruptly at around age 50.

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CATEGORIZED UNDER: Health & Medicine

Look at This: Every Recorded Hurricane Since 1851 on One Map

By Sophie Bushwick | August 24, 2012 9:16 am

hurricane map

The National Oceanic and Atmospheric Administration has a tropical storm and hurricane data archive that stretches back to 1851. But looking at each storm individually doesn’t have nearly as much impact as seeing them all projected onto a map at once. Data visualization expert John Nelson combined data on historical storms’ paths and intensities to create this stunning image, where the color of a dot represents that storm’s intensity.

The photo links to a larger version, but for a resolution high enough to see each individual point, click here.

[via io9]

Image courtesy of IDVsolutions / flickr

CATEGORIZED UNDER: Environment

Older Dads Pass on More Mutations to Their Kids

By Sophie Bushwick | August 23, 2012 2:24 pm

old dad

The hard-working precursor cells that produce sperm just can’t catch a break. Since men make sperm throughout their lives, these cells have to divide again and again, sending one copy of themselves off to become sperm cells each time. DNA doesn’t always copy itself perfectly, so over the years, genetic errors pile up. And now a new study has quantified just how many mutations sperm will accumulate—and pass on to any offspring—for fathers of various ages. Scientists think that these mutations may be partly to blame for the fact that children with older fathers tend to have higher rates of bipolar disorderschizophrenia, and autism.

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CATEGORIZED UNDER: Health & Medicine

Look at This: Glowing South American Roaches Mimic Toxic Beetles

By Veronique Greenwood | August 23, 2012 10:25 am

roaches

Under normal light, this roach looks normal enough. But under a fluorescent light, its three spots—two large ones and one very tiny one just visible under the right spot—light up like a Christmas tree.

This remarkable species of South American cockroach, Lucihormetica luckae, owes its fluorescence to bacteria. The spots on the dark brown area of its carapace are pits inhabited by microbes that glow under fluorescent light.

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CATEGORIZED UNDER: Living World

Mayan Tree Chopping May Have Worsened Droughts, and Contributed to The Civilization's Demise

By Sophie Bushwick | August 22, 2012 12:51 pm

Chac
The Mayan rain god Chac

Droughts do far worse than brown our lawns—the water shortages and crop damage they mete out, and the fires fed by dry conditions, have effects that last long after rain returns. These events may even have civilization-destroying powers: although doubts remain, many researchers consider drought one of the leading contributors to the collapse of the Maya. And a new study published in Geophysical Research Letters finds that by cutting down forests, Mayans may have directly contributed to the droughts that brought about the downfall of their society.

Like modern civilizations, Mayans felled trees in order to harvest the raw material and clear land for cities and crops. Researchers modeled how this deforestation affected local climate conditions with computer simulations. Cleared land absorbs less solar energy, which means it releases less moisture to contribute to rainfall. By comparing untampered or regrown forest to reconstructions of the tree cover during Mayan occupation, researchers found that razed land could have reduced annual rainfall by 5 to 15 percent. This means that of the estimated drought during the height of Mayan civilization, 60 percent of the rainfall decrease was likely due to deforestation.

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CATEGORIZED UNDER: Environment, Human Origins

Human Skull Begins to Fill in 20,000-Year Gap in Fossil Record

By Sophie Bushwick | August 22, 2012 11:15 am

spacing is important

Back in the day, in the northern part of modern-day Laos, an early modern human died and its corpse washed into a nearby cave. Sure, it doesn’t sound like a particularly noteworthy event. But researchers dated the remains of this human’s skull to at least 46,000 years ago, making it the oldest modern human ever discovered in Southeast Asia.

Scientists discovered the skull fragments back in 2009, but have only this week published their findings in the Proceedings of the National Academy of Sciences. Features not found in any earlier specimens of the Homo genus, such as the absence of a brow ridge on the skull’s frontal bone, mark it as a modern human.

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CATEGORIZED UNDER: Human Origins

No More Needles! Blood Cells Can Become Internal Sensors

By Sophie Bushwick | August 21, 2012 1:19 pm

spacing is important

As technology advances, electronic implants may or may not make their way into our bodies. But sometimes your own cells can prove sensors enough. Red blood cells, say scientists presenting work at the American Chemical Society meeting this week, could eventually be transformed to send doctors messages about your blood chemistry, without ever needing to leave the body.

Light, specifically near-infrared light, plays a starring role in this message-sending system. Near-infrared can seep through skin and strike the blood below. Scientists hope to eventually put special dye molecules into patients’ bloodstreams that will, if the blood is at a particular pH, for instance, send out a fluorescent glow when light hits them. A monitor that can detect that glow could let doctors keep tabs on blood chemistry without requiring blood samples.

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CATEGORIZED UNDER: Health & Medicine
MORE ABOUT: blood, pH, red blood cell, sensor

Aphids May Harvest Solar Energy Like Plants

By Sophie Bushwick | August 20, 2012 3:13 pm

aphids

Turning the sun’s rays into usable energy is a skill thought to be limited to plants, algae, and solar panels. But a new study suggests that aphids may be also possess this ability.

Aphids already stand out from other animals for their production of carotenoids, pigments that also help out the immune system—most organisms get carotenoids from food, rather than making them themselves. A group of French and Israeli researchers now suggests that the reason aphids expend energy making these pigments is because they play an additional role in aphid life: Carotenoids, which plants use in photosynthesis, could be helping aphids do some of the same tricks.

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CATEGORIZED UNDER: Living World

Hope Springs Anew for Reversible Male Birth Control

By Sophie Bushwick | August 17, 2012 2:38 pm

male pill
Hey baby, I take my pill every day…if you know what I mean

Women can choose from a plethora of reversible birth control options, including diaphragms, IUDs, and the Pill. On the other hand, when men want to be responsible without resorting to permanent infertility, they have only one choice: condoms. But a new study has found a compound that may hold the key to a reversible male birth control pill.

The manufacturers of any male pill face the daunting task of restraining the production of about 1,000 sperm per second. To create all those sperm, the testes depend on, among other things, a protein called bromodomain, or BRDT. It was this protein that researchers decided to hobble, using a compound called JQ1 can pass from the blood into the testes and bind to BRDT, preventing the molecule from carrying out its usual duties and the testes from producing viable sperm.

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CATEGORIZED UNDER: Health & Medicine

Meet Trogloraptor, a New Kind of Spider

By Veronique Greenwood | August 17, 2012 2:28 pm

spider

A spider recently discovered in caves in the Pacific Northwest is an odd beast: not only is it a new species, it’s got its own genus and even family to itself. Up to three inches wide with its legs extended, it sports long, sharp claws that suggest it’s a keen predator of some sort, but scientists currently have no idea what it eats. It was discovered hanging from rather messy webs on the ceilings of caves, as well as in undergrowth in redwood forests. Its genus name, Trogloraptor, means cave robber.

Former 80beats blogger Doug Main, now at Our Amazing Planet, has interviewed the scientists who made the discovery and has plenty more interesting details. Head on over to learn more, and to see pictures of its claws.

Image courtesy of  Griswold CE, Audisio T, Ledford JM 

CATEGORIZED UNDER: Living World
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