Category Archives: Science

Gut microbes, antibiotics linked to diabetes


Graph of the relationships between groups of bacterial species called OTUs found to occur together in mice either treated with antibiotics or not. Antibiotic-treated mice (red) have a very different, and less diverse, set of OTUs than the control mice (blue). Image courtesy of Nature Microbiology.

Graph of the relationships between groups of bacterial species called OTUs found to occur together in mice either treated with antibiotics or not. Antibiotic-treated mice (red) have a very different, and less diverse, set of OTUs than the control mice (blue). Image courtesy of Nature Microbiology.

Most of the cells in our bodies don’t belong to use; instead, they represent the host of micorganisms in our digestive tracts and play a critical role in extracting the nutrients from the foods we eat.

Yet until recently, scientists have paid little attention to the role these critters may play in our health, other than to ensure we get the nourishment we need to keep our own cells alive and well.

But as regular readers know, studies are revealing that they may play roles in the onset of a wide range of illnesses, ranging from multiple sclerosis and rheumatoid arthritis [our own affliction] to anorexia, chronic fatigue syndrome, and Alzheimer’s disease.

We also know that antibiotics, the drugs we’ve invented to treat once-fatal bacterial infections, can have a lethal impact on those same internally resident creatures, as we’ve sometimes experienced in the diarrhea often accompanying a heavy dose of antibiotics.

By killing off much of our internal alien population, could we actually be contributing to the rise of other dangerous conditions?

Specially, in this case, diabetes?

The answer may well be yes.

From the New York University Langone Medical Center:

In doses equivalent to those used regularly in human children, antibiotics changed the mix of gut microbes in young mice to dramatically increase their risk for type 1 diabetes. That is the finding of a study led by researchers from NYU Langone Medical Center with support from the Juvenile Diabetes Research Foundation (JDRF), and published August 22 in Nature Microbiology [$32 to download].

The study results center on the microbiome, the bacterial species in our guts that co-evolved with humans to play roles in digestion, metabolism, and immunity. As children’s exposure to microbe-killing antibiotics has increased in recent decades, the incidence of autoimmune diseases like type 1 diabetes has more than doubled. The average American child currently receives 10 courses of antibiotics by age 10.

Specifically, the new study found that short pulses of antibiotics cause mice that are susceptible to type 1 diabetes to develop the disease more quickly and more often than mice not treated with antibiotics.

“Our study begins to clarify the mechanisms by which antibiotic-driven changes in gut microbiomes may increase risk for type 1 diabetes,” says Martin Blaser, MD, the Muriel G. and George W. Singer Professor of Translational Medicine at NYU School of Medicine, and the study’s senior author. “This work uses NOD mice, the best model of type 1 diabetes to date, and doses of antibiotics like those received by most children to treat common infections.”

“This latest study result is compelling, linking the effects of use of antibiotics in mice to type 1 diabetes,” says Jessica Dunne, director of discovery research at JDRF. “This is the first study of its kind suggesting that antibiotic use can alter the microbiota and have lasting effects on immunological and metabolic development, resulting in autoimmunity. We’re eager to see how these findings may impact the discovery of type 1 diabetes preventive treatments in the future and continued research in the area of vaccines.”

More after the jump. . .
Continue reading

Destructive ‘afterslip’ followed Napa earthquake


And free books, too

We’ll begin with the free books.

We were once buried in books.

It was at 0136 hours on 3 September 2000 and we were sitting in our recliner in the livingroom of our apartment in Napa California when the lights went out and we were pummeled repeatedly by invisible assailants.

It was a magnitude 5.2 earthquake, and our assailants were books, an avalanche vomited forth by falling and collapsing bookcases.

We’re moving this weekend, and we again are buried in books, too many to carry south to L.A., so every day this week we’re putting lots of them out on the media between sidewalk and street, free for one and all.

The address is 2032 Prince Street in Berkeley [one house south of Shattuck Avenue between the Starry Plow and the Ashby BART station], and subjects range for brain/mind science to history, science, biography, media, and much more.

Fresh offerings daily through Saturday.

And the afterslips from another Napa quake

A map shows the location of the August 24, 2014 earthquake just south of Napa, California. In a new report, scientists from MIT and elsewhere detail how, even after the earthquake’s main tremors and aftershocks died down, earth beneath the surface was still actively shifting and creeping — albeit much more slowly — for at least four weeks after the main event. Image: Gareth Funning/University of California, Riverside

A map shows the location of the August 24, 2014 earthquake just south of Napa, California. In a new report, scientists from MIT and elsewhere detail how, even after the earthquake’s main tremors and aftershocks died down, earth beneath the surface was still actively shifting and creeping — albeit much more slowly — for at least four weeks after the main event.
Image: Gareth Funning/University of California, Riverside

A fascinating story from the Massachusetts Institute of Technology:

Nearly two years ago, on August 24, 2014, just south of Napa, California, a fault in the Earth suddenly slipped, violently shifting and splitting huge blocks of solid rock, 6 miles below the surface. The underground upheaval generated severe shaking at the surface, lasting 10 to 20 seconds. When the shaking subsided, the magnitude 6.0 earthquake — the largest in the San Francisco Bay Area since 1989 — left in its wake crumpled building facades, ruptured water mains, and fractured roadways.

But the earthquake wasn’t quite done. In a new report, scientists from MIT and elsewhere detail how, even after the earthquake’s main tremors and aftershocks died down, earth beneath the surface was still actively shifting and creeping — albeit much more slowly — for at least four weeks after the main event. This postquake activity, which is known to geologists as “afterslip,” caused certain sections of the main fault to shift by as much as 40 centimeters in the month following the main earthquake.

This seismic creep, the scientists say, may have posed additional infrastructure hazards to the region and changed the seismic picture of surrounding faults, easing stress along some faults while increasing pressure along others.

The scientists, led by Michael Floyd, a research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences, found that sections of the main West Napa Fault continued to slip after the primary earthquake, depending on the lithology, or rock type, surrounding the fault. The fault tended to only shift during the main earthquake in places where it ran through solid rock, such as mountains and hills; in places with looser sediments, like mud and sand, the fault continued to slowly creep, for at least four weeks, at a rate of a few centimeters per day.

“We found that after the earthquake, there was a lot of slip that happened at the surface,” Floyd says. “One of the most fascinating things about this phenomenon is it shows you how much hazard remains after the shaking has stopped. If you have infrastructure running across these faults — water pipelines, gas lines, roads, underground electric cables — and if there’s this significant afterslip, those kinds of things could be damaged even after the shaking has stopped.”

There’s lots more, after the jump. . .

Continue reading

Plastic food packaging to get edible replacement


We posted extensively about the health dangers posed by the plastics used to contain the foods we eat. The stuff ha been linked to everything from cancer obesity to ADHD and and the growth of man boobs.

And now comes word that scientists are developing a replacement, one we can eat.

From Bloomberg:

Much of the plastic packaging we see in the grocery store can be recycled, from egg containers, to milk jugs, to butter tubs. But what about that thin plastic film stretched around wedges of manchego in the cheese bin or the 16-ounce rib-eye in the chiller case?

It turns out that kind of plastic is tougher to recycle and might even be adding harmful chemicals to your food. Oh, and it’s not even good at doing what it’s supposed to do: prevent food spoilage.

Luckily, researchers are investigating alternative forms of food packaging—the kind you can eat.

U.S. Department of Agriculture researchers have discovered that a milk protein called casein can be used to develop an edible, biodegradable packaging film. The casein-based film is up to 500 times better than plastic at keeping oxygen away from food because proteins form a tighter network when they polymerize, the researchers found. It’s also more effective than current edible packaging materials made from starch and protects food products that are sensitive to light.

To produce a more practical packaging material, the team added glycerol and citrus pectin to the casein film, which is made by spreading a mixture of water and commercially available casein powder. Glycerol made the protein film softer, and citrus pectin added more structure to the film, allowing it to resist humidity and high temperatures better. Bonnaillie said the additives used by researchers also distinguish their packaging, because pectin is good for us.

Flavorings, vitamins, and other additives can be used to make the packaging, and the food it surrounds, tastier and more nutritious.

Sounds like a good idea.

Zika may cause adult memory loss, depression


Zika in the adult brain: Illumination of the fluorescent biomarker in green revealed that Zika can infect the adult mouse brain in a region full of neural progenitor cells, which play an important role in learning and memory.

Zika in the adult brain: Illumination of the fluorescent biomarker in green revealed that Zika can infect the adult mouse brain in a region full of neural progenitor cells, which play an important role in learning and memory. From the study.

Zika, the mosquito-borne virus that spread from West Africa to Latin America and the Western Pacific and resident in Florida, not only causes shrunken skulls and damaged brain in infants born to infected mothers. It may also cause depression and Alzheimer’s-like memory loss in adults.

That’s the disturbing finding of new research on the impact of the virus on the human brain.

From the Rockefeller University:

Concerns over the Zika virus have focused on pregnant women due to mounting evidence that it causes brain abnormalities in developing fetuses. However, new research in mice from scientists at The Rockefeller University and La Jolla Institute for Allergy and Immunology suggests that certain adult brain cells may be vulnerable to infection as well. Among these are populations of cells that serve to replace lost or damaged neurons throughout adulthood, and are also thought to be critical to learning and memory.

“This is the first study looking at the effect of Zika infection on the adult brain,” says Joseph Gleeson, adjunct professor at Rockefeller, head of the Laboratory of Pediatric Brain Disease, and Howard Hughes Medical Institute investigator. “Based on our findings, getting infected with Zika as an adult may not be as innocuous as people think.”

Although more research is needed to determine if this damage has long-term biological implications or the potential to affect behavior, the findings suggest the possibility that the Zika virus, which has become widespread in Central and South America over the past eight months, may be more harmful than previously believed. The new findings were published in Cell Stem Cell[open access] on August 18.

“Zika can clearly enter the brain of adults and can wreak havoc,” says Sujan Shresta, a professor at the La Jolla Institute of Allergy and Immunology. “But it’s a complex disease—it’s catastrophic for early brain development, yet the majority of adults who are infected with Zika rarely show detectable symptoms. Its effect on the adult brain may be more subtle, and now we know what to look for.”

Neuronal progenitors

Early in gestation, before our brains have developed into a complex organ with specialized zones, they are comprised entirely of neural progenitor cells. With the capability to replenish the brain’s neurons throughout its lifetime, these are the stem cells of the brain. In healthy individuals, neural progenitor cells eventually become fully formed neurons, and it is thought that at some point along this progression they become resistant to Zika, explaining why adults appear less susceptible to the disease.

But current evidence suggests that Zika targets neural progenitor cells, leading to loss of these cells and to reduced brain volume. This closely mirrors what is seen in microcephaly, a developmental condition linked to Zika infection in developing fetuses that results in a smaller-than-normal head and a wide variety of developmental disabilities.

The mature brain retains niches of these neural progenitor cells that appear to be especially impacted by Zika. These niches—in mice they exist primarily in two regions, the subventricular zone of the anterior forebrain and the subgranular zone of the hippocampus—are vital for learning and memory.

There’s more, after the jump. . . Continue reading

Time to book your Northwest Passage cruise


Yep, the Northwest Passage, the impossible dream of early European explorers of an Arctic waters shortcut to Asia, is now open.

From NASA’s Earth Observatory:

BLOG Passage

From NASA:

In August 2016, tourists on a luxury cruise departed Seward Alaska and steered toward the waterways of the Canadian Arctic Archipelago. The excursion is one example of the growing human presence in an increasingly ice-free Northwest Passage—the famed high-latitude sea route that connects the northern Atlantic and Pacific oceans. In mid-August 2016, the southern route through the Passage was nearly ice-free.

For most of the year, the Northwest Passage is frozen and impassible. But during the summer months, the ice melts and breaks up to varying degrees. The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured the top image of the Northwest Passage on August 9, 2016. A path of open water can be traced along most of the distance from the Amundsen Gulf to Baffin Bay.

“It was a warm winter and spring,” said NASA sea ice scientist Walt Meier. That means that the seasonal ice—ice that grew since the end of last summer, and the type found throughout most of the Passage—is thinner than normal. Thinner ice can melt more easily, break up, and move out of the channels.

A scattering of broken ice is visible just east of Victoria Island. “It looks pretty thin and disintegrating,” Meier said. “I think an ice-strengthened ship could get through without too much trouble.”

The open water this year flows along the southern route, or “Amundsen route.” It’s not unusual for the southern route to open up to some degree, as it is more protected than the northern route and receives less sea ice directly from the Arctic Ocean.

At some point in almost every summer since 2007, conditions along the southern passage have been fairly open. There have been exceptions; the second image shows the Northwest Passage on August 9, 2013, as observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite. Ice that year was relatively extensive. Turn on the image comparison tool to see the difference.

What’s left of the ice in 2016 is opening up fast. Meier expects that the Northwest Passage will open up completely in the next couple of weeks. Moreover, a strong Arctic cyclone appears to be approaching the archipelago. It could push the ice around and further open up still-blocked channels. Or, it could have the opposite effect and push in ice from the north.

The Great British Bee Pesticidal Massacre


A sad story, and ominous, via Quartz:

Since around 2002, farmers in the English countryside have been using neonic insecticides to protect their abundant oilseed crops spanning 8.2 million hectares. Now, scientists are linking the chemicals, also called neonicotinoids, to the death of half of the wild bee population in the country, according to a new study published in Nature Communications [open access].

Many bee species forage on the bright yellow oilseed crops that grow in the UK. The seeds for these crops are coated with neonicotinoids upon planting. Then, the chemical systematically expresses itself in all cells of the growing plant. Bees that feed on the plant ingest the chemical through the pollen or nectar.

Researchers studied 62 species of wild bees across England from 1994 to 2011. Over the last nine years, the decline in population size was three times worse among species that regularly fed on oilseed plants compared to others that forage on different floral resources, the study found. Five species showed declines of 20% or more, with the worst-hit species experiencing a 30% drop in its population.

In Europe, 9.2% of the continent’s almost 2,000 bee species are facing extinction, according to one assessment. But until now, it’s been hard to quantify how seriously chemicals have impacted bees. “Pesticides and beekeeping have been butting heads for 50-plus years,” David R. Tarpy, a professor at North Carolina State University’s department of entomology, told Quartz.“[Pesticides are] clearly part of the equation, but we don’t know the relative magnitude.” Habitat loss and mites also have a hand in the declining bee populations but the latest findings is hard to ignore. Especially since neonic pesticides may also harm birds, butterflies, and water-borne invertebrates, according to Mother Jones.

Interracial couples trigger disgust in brains of many


Following on the heels of yesterday’s posts about racism and racial divides in the U.S. comes new research from the University of Washington revealing that, for many folks, racism is buried deeply in the brain.

The findings aren’t so surprising, but their confirmation is another sad, tragic proof that the “post-racial America” so often decreed by Republicans and others is nothing but a myth.

From the University of Washington:

Interracial marriage has grown in the United States over the past few decades, and polls show that most Americans are accepting of mixed-race relationships.

A 2012 study by the Pew Research Center found that interracial marriages in the U.S. had doubled between 1980 and 2010 to about 15 percent, and just 11 percent of respondents disapproved of interracial marriage.

But new research [Elsevier wants $35.95 to let you read it] from the University of Washington suggests that reported acceptance of interracial marriage masks deeper feelings of discomfort — even disgust — that some feel about mixed-race couples. Published online in July in the Journal of Experimental Social Psychology and co-authored by UW postdoctoral researcher Caitlin Hudac, the study found that bias against interracial couples is associated with disgust that in turn leads interracial couples to be dehumanized.

Lead author Allison Skinner, a UW postdoctoral researcher, said she undertook the study after noting a lack of in-depth research on bias toward interracial couples.

“I felt like the polls weren’t telling the whole story,” said Skinner, a researcher in the UW’s Institute for Learning & Brain Sciences.

The research involved three experiments. In the first, 152 college students were asked a series of questions about relationships, including how disgusted they felt about various configurations of interracial relationships and about their own willingness to have an interracial romance. The participants overall showed high levels of acceptance and low levels of disgust about interracial relationships, and pointed to a strong negative correlation between the two.

In the second experiment, the researchers showed 19 undergraduate students wedding and engagement photos of 200 interracial and same-race couples while recording their neural activity. The researchers asked the students to quickly indicate whether each couple should be included in a future study on relationships, a task that was intended to ensure participants were socially evaluating the couples while their neural activity was recorded.

Participants responded faster to images of same-race couples and selected them more often for inclusion in the study. More significantly, Skinner said, participants showed higher levels of activation in the insula — an area of the brain routinely implicated in the perception and experience of disgust — while viewing images of interracial couples.

“That indicates that viewing images of interracial couples evokes disgust at a neural level,” Skinner said.

There’s more, after the jump. . . Continue reading