Category Archives: Science

Gut bacteria: We share them with our kin


A family tree showing how different strains of Bifidobacteriaceae bacteria evolved in humans [blue] and our hominid relatives, the gorilla [green], chimp [yellow] and bonobo [red].

A family tree showing how different strains of Bifidobacteriaceae bacteria evolved in humans [blue] and our hominid relatives, the gorilla [green], chimp [yellow] and bonobo [red].

We’ve been posting quite a bit about the critters inside us, organisms that comprise the majority of the cells inside our skins.

They’ve been linked with a growing list of human afflictions, as we’ve noted in previous posts about  Previous posts have noted newly established links between our intestinal microbes and multiple sclerosis, rheumatoid arthritis, chronic fatigue syndrome, anorexia, Alzheimer’s disease, and even our emotional states.

And now comes the latest intestinal microbial discovery, genetic traits they share in large part with their relatives in the guts of our own relatives.

From the University of California, Berkeley: [emphasis added]

For all the anxiety today about the bacteria in our gut being under constant assault by antibiotics, stress and bad diets, it turns out that a lot of the bacteria in our intestines have been with us for at least 15 million years, since we were pre-human apes.

A new comparison [$30 for a one-day access] of the gut microbiomes of humans, chimps (our closest ancestor), bonobos and gorillas shows that the evolution of two of the major families of bacteria in these apes’ guts exactly parallels the evolution of their hosts.

This shows that the microbes in our guts are determined in part by our evolutionary history, not just external factors like diet, medicine and geography. Obesity, cancer and some inflammatory diseases, such as diabetes and Crohn’s disease, have been linked to imbalances in the mix of microbes in our stomach and intestines.

“We are showing that some human gut bacteria are the direct descendant of gut bacteria that lived within our common ancestors with apes,” said lead researcher Andrew Moeller, a Miller Postdoctoral Fellow in UC Berkeley’s Museum of Vertebrate Zoology. “It shows there has been an unbroken line of inheritance or transfer from one generation to another for millions of years, since the dawn of African apes.”

Moeller is beginning to assemble a snapshot of the microbes in the guts of our ancient ape ancestor — in essence, a paleo gut that fit our paleo diet — and hopes to go even further back in time if, as seems likely, all mammals have evolved their unique microbiota from a common ancestral population in the distant past.

“We now have samples from all the major groups of mammals, and we’re working on tracing the evolution of the microbiome all the way back to when we were tiny carnivorous creatures 100 million years ago,“ he said.

There’s more, after the jump. Continue reading

Chicken smells drive malarial mosquitoes away


Not only do chickens provide eggs, table meat, and Jewish penicillin; they also appear to possess mosquito-repelling aromas, offering a new way for folks to keep them at bay.

From BBC News:

The smell from a live chicken could help protect against malaria, researchers have found.

Ethiopian and Swedish scientists discovered that malarial mosquitoes tend to avoid chickens and other birds. The experiments, conducted in western Ethiopia, included suspending a live chicken in a cage near a volunteer sleeping under a bed net.

>snip<

The scientists, whose research was published in the Malaria Journal, concluded that as mosquitoes use their sense of smell to locate an animal they can bite there must be something in a chicken’s odour that puts the insects off.

Addis Ababa University’s Habtie Tekie, who worked on the research, said that the compounds from the smell of the chicken can be extracted and could work as a repellent.

Field trials for this stage of the research are now “in the pipeline”, he told the BBC.

Antioxidants may do more harm than good


One of thousands of products peddled with the promise of antioxidant health benefits.

One of thousands of products peddled with the promise of antioxidant health benefits.

You hear about them all the time, and countless foods and supplements containing them are peddled with promises that they’ll fix you up, keep you healthy, and put a little extra spring in your step.

But do antioxidants really fulfill all that hype? Or can filling up on them actually be harmful to your health?

A new cautionary note has been sounded in a study from scientists in Britain and the Netherlands, and our post includes the announcements from their respective universities.

First, from Maastricht University:

Researchers Professor Pietro Ghezzi of the Brighton and Sussex Medical School and Professor Harald Schmidt of Maastricht University urge caution in the use of antioxidants. Many people take antioxidants to treat or prevent disease. Ghezzi and Schmidt’s research has shown that such supplements help only in clear cases of vitamin deficiency, and that some antioxidants may even have harmful effects. The study has been published in the British Journal of Pharmacology.

Gut microbes linked to Alzheimer’s progression


The human body is an interspecies cooperative, the with bulk of the cells in our body belonging to other species than homo sapiens, primarily the bacteria within out gut that enable us to digest the food on which our very lives depend.

But those bacteria excrete all manner of chemicals, and we’re only now beginning to learn that the complex stew they brew impacts us in very many ways.

Previous posts have noted newly established links between our intestinal microbes and multiple sclerosis, rheumatoid arthritis, chronic fatigue syndrome, anorexia, Alzheimer’s disease, and even our emotional states.

And now comes the latest bombshell: Our intestinal inhabitants impact the development of Alzheimer’s disease.

From the University of Chicago:

Long-term treatment with broad spectrum antibiotics decreased levels of amyloid plaques, a hallmark of Alzheimer’s disease, and activated inflammatory microglial cells in the brains of mice in a new study by neuroscientists from the University of Chicago.

The study, published July 21, 2016, in Scientific Reports, also showed significant changes in the gut microbiome after antibiotic treatment, suggesting the composition and diversity of bacteria in the gut play an important role in regulating immune system activity that impacts progression of Alzheimer’s disease.

“We’re exploring very new territory in how the gut influences brain health,” said Sangram Sisodia, PhD, Thomas Reynolds Sr. Family Professor of Neurosciences at the University of Chicago and senior author of the study. “This is an area that people who work with neurodegenerative diseases are going to be increasingly interested in, because it could have an influence down the road on treatments.”

Two of the key features of Alzheimer’s disease are the development of amyloidosis, accumulation of amyloid-ß (Aß) peptides in the brain, and inflammation of the microglia, brain cells that perform immune system functions in the central nervous system. Buildup of Aß into plaques plays a central role in the onset of Alzheimer’s, while the severity of neuro-inflammation is believed to influence the rate of cognitive decline from the disease.

For this study, Sisodia and his team administered high doses of broad-spectrum antibiotics to mice over five to six months. At the end of this period, genetic analysis of gut bacteria from the antibiotic-treated mice showed that while the total mass of microbes present was roughly the same as in controls, the diversity of the community changed dramatically. The antibiotic-treated mice also showed more than a two-fold decrease in Aß plaques compared to controls, and a significant elevation in the inflammatory state of microglia in the brain. Levels of important signaling chemicals circulating in the blood were also elevated in the treated mice.

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

Quantifying the Sierra National Forest tree die-off


From NASA’s Earth Observatory:

BLOG Trees

From NASA:

Mass tree die-offs are sparking worries of fire in California’s Sierra Nevada range. An outbreak of bark beetles, along with persistent drought in the state, have caused many evergreen trees to wither and die.

The damage spread rapidly through the mountains in the fall of 2015 after favorable spring conditions (warm and dry) led to a surge in beetle populations, according to Zach Tane, a remote sensing analyst with the U.S. Forest Service (USFS). The beetles burrow under a tree’s bark and lay their eggs. Once they penetrate the tree’s armor (the bark), they begin to gnaw into its living tissue, the phloem.

“Needles don’t turn red the next day. It’s a slow process of the tree dying, and it has to do with life cycle of bark beetle and how long needles can persist in a green state,” said Tane. “As the population of beetles grows, they can overwhelm the natural defenses of a tree. There’s a tipping point—that’s what happened in Colorado and probably what’s happening here.”

There has never been an outbreak of this magnitude recorded in the Sierra Nevada, according to Tane. The maps above depict some of the damage as observed by NASA’s Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument. AVIRIS is an optical sensor that collects data in 224 spectral bands, ranging from visible blue (0.4 µm) to shortwave infrared (2.5 µm). Researchers can make inferences about tree health from the way the leaves absorb and scatter light.

When trees die, they lose water and chlorophyll. This allows the cellulose and lignin in the leaves to become more apparent in the 2 to 2.5 µm region of the spectrum (which is invisible to the human eye). AVIRIS gives researchers the ability to distinguish cellulose and lignin from other brown matter like soil. The Forest Service uses data from AVIRIS and other sources to quantify the health of forests and to make projections of wildfire risk in the wildland-urban interface, the fire-vulnerable zone where wilderness and human cities and towns meet.

The Forest Service also routinely uses data from Landsat, a satellite that gives systematic, frequent coverage and good spatial resolution (30 meters per pixel). The USFS Pacific Southwest Region Remote Sensing Lab at the University of California, Davis, has developed an advanced analysis system that can automatically extract forest disturbance information from Landsat’s two overpasses each month. The system, called Ecosystem Disturbance and Recovery Tracker (eDaRT), will soon be deployed in California to make tree mortality information more readily available to vegetation managers as they plan forest treatment, restoration, and salvage logging.

Fracking wells linked with increased asthma rates


Fracking, the extraction of shale-trapped of oil and gas by hydraulic fracturing, using water laced with a noxious brew of chemicals injected under high pressure to break up the readily fissile rock and trigger the release of the precious hydrocarbons.

Fracturing has been fraught with problem, ranging from the contamination of drinking water wells to the release of chemically laden water from containment ponds into nearby streams and lakes.

Most infamously, fracking has given us home water taps so loaded with natural gas that a spark gives us a mix of water and flame.

Which leads to a question, expressed in music and animation by students of Studio 20 at the Arthur L. Carter Journalism Institute at New York University:

The Fracking Song (My Water’s On Fire Tonight)

Program notes:

“My Water’s On Fire Tonight” is a product of Studio 20 NYU (http://bit.ly/hzGRYP) in collaboration with ProPublica.org (http://bit.ly/5tJN). The song is based on ProPublica’s investigation on hydraulic fractured gas drilling (read the full investigation here: http://bit.ly/15sib6).

Music by David Holmes and Andrew Bean
Vocals and Lyrics by David Holmes and Niel Bekker
Animation by Adam Sakellarides and Lisa Rucker

The fracking/asthma link established

And now comes evidence that fracking also leads to a rise in asthma in nearby residents.

From the Johns Hopkins Bloomberg School of Public Health in Baltimore [H/T to Newswise]:

People with asthma who live near bigger or larger numbers of active unconventional natural gas wells operated by the fracking industry in Pennsylvania are 1.5 to four times likelier to have asthma attacks than those who live farther away, new Johns Hopkins Bloomberg School of Public Health research suggests.

The findings [open access], published July 18 in JAMA Internal Medicine, add to a growing body of evidence tying the fracking industry to health concerns. Health officials have been concerned about the effect of this type of drilling on air and water quality, as well as the stress of living near a well where just developing the site of the well can require more than 1,000 truck trips on once-quiet roads. The fracking industry has developed more than 9,000 wells in Pennsylvania in just the past decade.

“Ours is the first to look at asthma but we now have several studies suggesting adverse health outcomes related to the drilling of unconventional natural gas wells,” says study leader Sara G. Rasmussen, MHS, a PhD candidate in the Bloomberg School’s Department of Environmental Health Sciences. “Going forward, we need to focus on the exact reasons why these things are happening, because if we know why, we can help make the industry safer.”

For the study, Rasmussen and her colleagues analyzed health records from 2005 through 2012 from the Geisinger Health System, a health care provider that covers 40 counties in north and central Pennsylvania. The study is a joint effort of the Bloomberg School and the Geisinger Health System. Hopkins researchers identified more than 35,000 asthma patients between the ages of five and 90 years. They identified 20,749 mild attacks (requiring a corticosteroid prescription), 1,870 moderate ones (requiring an emergency room visit) and 4,782 severe attacks (requiring hospitalization). They mapped where the patients with these attacks lived; assigned them metrics based on the location, size, number, phase, total depth and gas production of the wells; and compared them to asthma patients who didn’t have attacks in the same year.

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

Mexican gov’t Aytozinapa claims hit once again


The disappearance of 43 students from the Raúl Isidro Burgos Rural Teachers’ College of Ayotzinapa after police opened fire on them on the night of 26 September 2014 [previously] remains an open sore on the Mexican body politic.

President Enrique Peña Nieto’s administration has been eager to sweep the presumptive massacre under the rug, or at least relegate the whole bloody mess to the past, but their own incompetence in stage-managing the coverup has been nothing less than inflammatory.

The government claims it has discovered the “historical truth,” claiming all the students were slain byu drug gang members and the bodies then incinerated in a dumping group with the ashes tossed into a nearby stream.

The latest revelation via teleSUR English:

An inquiry published Saturday has revealed that there is virtually no physical evidence to support the Mexican government’s version of the 2014 disappearance of 43 students traveling by bus to Mexico City. Government officials insist that a drug gang kidnapped the students at gunpoint, killed them and burned the bodies at a dumpsite near the southwestern town of Iguala, but the report, based on forensic records requested by the Associated Press, revealed no signs of a fire on the night in question.

But the notes of a forensic examination of the Cocula dumpsite in Guerrero state in western Mexico shows that investigators could not confirm a fire on the night that the students vanished on September 26, 2014. The AP obtained the documents under a freedom of information request permissible under Mexican law,

The AP inquiry is the latest in a series of independent investigations that undermines the Mexican government’s version of events. Police say that five suspects have confessed to the crimes but an international panel of experts earlier this year concluded that the confessions were obtained by torture.

Earlier this year the Argentine Forensic Anthropology Team (EAAF) found animal and human remains at the dumpsite but said none of the remains corresponded to the government’s allegation that the bodies were incinerated by members of the Guerreros Unidos cartel. The Attorney General’s Office in April presented evidence of a huge fire and the discovery of the remains of at least 17 adults but the bone fragments were too badly burned to identify, the Argentine team said.

The government’s handling of the case has triggered massive protests that include parents and friends of the students, trade unions and grassroots organizations who believe that law-enforcement authorities are complicit in the slayings of the 43 students, who had effectively stolen a bus, ironically enough, to attend the commemoration of a 1968 police massacre of students.

More from the Associated Press report:

The report from international fire experts convened by the government was obtained by The Associated Press through an open records request. It shows the experts found evidence the Cocula dump had been the site of at least five fires, but could not determine when. Remains of 17 people were also found, but it was unknown when they were burned.

“The duration and dates of the fires could not be established based on the available physical data,” the report said.

>snip<

There was no information about the identities of the 17 remains found, but it was known that the remote dump had become a place to dispose of bodies for some time in an area where hundreds have gone missing.

>snip<

The Argentine team had previously advised of shell casings that suddenly appeared at the site and were later touted by the government as evidence that the students were executed at the dump.

Santiago Aguirre, deputy director of the nonprofit Miguel Agustin Pro Juarez Center for Human Rights, which is representing the students’ families, said Friday the report displayed serious deficiencies and was part of “a deliberate attempt to fabricate a version not supported by scientific evidence.”

Before departing Mexico at the end of April, the team from the Inter-American Human Rights Commission urged the government to drop its theory and explore details in the investigation that point to other possible destinations for the students’ remains.

And because authorities failed to maintain control of the site, fabricated evidence could have been added to the already chaotic mix