Comment

Comment by Dr. Krishna Kumari Challa on Saturday

In some of the world’s least-developed countries, spacing births two years apart, instead of one, can nearly halve infant mortality rates, a study finds.

Short birth intervals have been linked to poor health outcomes for moms and infants for decades, though the exact causes aren’t clear. Research has shown that the mothers’ bodies can struggle to recover and provide nutrients to children. In addition, siblings that are close in age may compete for the same resources, crucially breast milk, and are exposed to similar diseases.  

Babies born in the shortest birth intervals to uneducated mothers living in countries with high infant mortality — at least 100 babies dying for every 1,000 births — were in the greatest danger. (The researchers used infant mortality rate as a proxy for a country’s level of development.) In those circumstances, babies born within one year of an older sibling had around a 22 percent chance of dying before age 1. That chance dropped to about 13 percent when the birth interval increased to two years.

J. Molitoris, K. Barclay and M. Kolk. When and where birth intervals matter for child survival: An intern.... Demography. Published online July 3, 2019. doi: 10.1007%2Fs13524-019-00798-y.

E. Rogers and R. Stephenson. Examining temporal shifts in the proximate determinants of fertilit... Journal of Biosocial Science. Vol. 50, July 2018, p. 551. doi: 10.1017/S0021932017000529

Comment by Dr. Krishna Kumari Challa on Friday

Combination Strategy Nearly Eliminates Invasive Mosquitoes in Field

Researchers use two techniques—Wolbachia infection and irradiation—to suppress reproduction in populations of Asian tiger mosquitoes at two study sites in China.

Asian tiger mosquitoes (Aedes albopictus) are among the world’s most invasive mosquito species and can spread dengue and Zika viruses. In a study published on July 17 in Nature, an international team of researchers has virtually eradicated populations of the insects from two residential areas in China.

The researchers infected the insects with the bacterium Wolbachia to limit embryo viability and, as an added precaution, irradiated mosquitoes to induce sterility, and then released millions of male mosquitoes, which don’t bite, at their test sites. The males mated with local females, resulting in a drastic reduction in the populations of A. albopictus. 

This work is promising for control of these mosquitoes in local populations.

Comment by Dr. Krishna Kumari Challa on July 17, 2019 at 11:29am

Machine learning has helped scientists identify bat species which could host Nipah virus, the cause of lethal outbreaks afflicting people in South and Southeast Asia. These results, published in PLoS Neglected Tropical Diseases, also flagged four new bat species as surveillance priorities. Nipah virus is a highly lethal, emerging henipavirus that can be transmitted to people from the body fluids of infected bats. Eating fruit or drinking date palm sap that has been contaminated by bats has been flagged as a transmission pathway. Once infected, people can spread the virus directly to other people, sparking an outbreak. Domestic pigs are also bridging hosts that can infect people. There is no vaccine and the virus has a high mortality rate. 

India is home to an estimated 113 bat species. Just 31 of these species have been sampled for Nipah virus, with 11 found to have antibodies that signal host potential. The team compiled published data on bat species known to carry Nipah and other henipaviruses globally. Data included 48 traits of 523 bat species, including information on foraging methods, diet, migration behaviors, geographic ranges and reproduction. They also looked at the environmental conditions in which reported spillovers occurred. Then they applied a trait-based machine learning approach to a subset of species that occur in Asia, Australia, and Oceana. Their algorithm identified known Nipah-positive bat species with 83 percent accuracy. It also identified six bat species that occur in Asia, Australia and Oceana that have traits that could make them competent hosts and should be prioritized for surveillance. Four of these species occur in India, two of which are found in Kerala.

The study is a starting point for the research needed to contain Nipah at its source.

https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd....

Comment by Dr. Krishna Kumari Challa on July 9, 2019 at 8:54am

A common gut virus that maps our travels

A San Diego State University researcher has found evidence that a virus nicknamed crAssphage, found in the guts of about 70 percent of the world's population, has a country-specific biomarker that changes rapidly as humans travel from one location to another.

Bioinformatics researcher and professor Rob Edwards' study is the first to examine the global similarity of viruses in the human microbiome. His research also suggests that a relative of this crAssphage was living in primates and may have evolved alongside humans for millions of years. The research will be published in Nature Microbiology July 8th.

https://www.eurekalert.org/pub_releases/2019-07/sdsu-acg070519.php

Comment by Dr. Krishna Kumari Challa on June 30, 2019 at 11:34am

Cleaning water and then producing electricity by using bacteria!

Sounds unbelievable but true!

Sewage treatment plants use bacteria to metabolise the organic material in waste water now.  At the end of the process, the microbes can make up a third by weight of the leftovers to be disposed of. Before being put in landfill, this “microbe cake” itself needs to be heat-sterilised and chemically treated, which uses a lot of energy.

Microbial fuel cells have long been touted as the way forward. The idea is that the biochemistry involved in metabolising the contaminants can yield electricity to help power the process. But fuel cells of this kind have been very difficult to scale up outside the lab.

Some companies use strains of Geobacter and another microbe called Shewanella oneidensis   to process the sludge. Its proprietary mix of organisms has one key advantage – the bacteria liberate some electrons as they respire, effectively turning the whole set-up into a battery. This has the added benefit of slowing bacterial growth, so that at the end of the process you have electricity and no microbe cake.

“The bacteria that purify the water also liberate electrons, turning the set-up into a battery“

Comment by Dr. Krishna Kumari Challa on June 24, 2019 at 7:06am

Alternative to plastics: Seafood shells

We are facing plastic pollution like hell. 

Some scientists think it’s possible to tackle the  problem at once. Crustaceans’ hardy shells contain chitin, a material that, along with its derivative chitosan, offers many of plastic’s desirable properties and takes only weeks or months to biodegrade, rather than centuries.

The challenge is getting enough pure chitin and chitosan from the shells to make bio-based “plastic” in cost-effective ways. 

Chitin is one of the most abundant organic materials in the world, after cellulose, which gives woody plants their structure. In addition to crustaceans, chitin is found in insects, fish scales, mollusks and fungi. Like plastic, chitin is a polymer, a molecular chain made from repeating units. The building block in chitin, N-acetyl-D-glucosamine, is a sugar related to glucose. Chitin and chitosan are antibacterial, nontoxic and used in cosmetics, wound dressings and pool-water treatments, among other applications.

Only thing that stands in between using it and plastic is viable and green technology to obtain chitin. Right now scientists are trying various methods - using microbes to obtain chitin is one of them.

https://www.sciencenews.org/article/seafood-shells-chitin-plastic-f...

Comment by Dr. Krishna Kumari Challa on June 20, 2019 at 9:09am

Here is a heart-warming news:  In Science the world Still Trusts!  Despite pseudo-science's dirty dance! 
Roughly 7 in 10 people around the world say they trust scientists and want to learn more about science and health, an international survey shows

Among the survey's major findings:

• A greater share of younger people claim some knowledge of science than older people. "Worldwide, more than half the people aged 15–29 (53%) say they know 'some' or 'a lot' about science, compared to 40% of those aged 30–49 and 34% of those aged 50 and older," say the authors of the report.
• Overall, people around the world are interested in science, with 62% saying they would like to learn more about it.
• The understanding of concepts such as "science" and "scientist" vary around the world. For example, about 32% of people in Central Africa said "they understood none of the definitions presented to them or simply didn't know what science and scientist meant, the report shows. In contrast, about 2% in Northern America and most of Europe gave a similar answer.
• 18% of those interviewed have a "high" level of trust in scientists; 54% reported "medium" levels of trust, 14% have "low" trust and 13% said they don't know.
• About 70% of those surveyed say they feel that science benefits them. Only about 40% say they feel science benefits most people in their nation.

Do You Trust Science?

https://wellcome.ac.uk/reports/wellcome-global-monitor/2018

https://news.gallup.com/opinion/chairman/258329/trust-science.aspx

https://www.usnews.com/news/best-countries/articles/2019-06-19/the-...

Comment by Dr. Krishna Kumari Challa on June 18, 2019 at 7:06am

Clinical Trials Involving Fecal Transplants have their own risks

The US Food and Drug Administration issued a safety alert for fecal transplant procedures after two immune-compromised patients contracted drug-resistant infections, according to a statement from the agency’s website. The patients received transplants from the same donor, and one of the patients died. As a result, the agency plans to suspend clinical trials involving the procedure.

Fecal matter transplants (FMT) are not yet officially approved by the US Food and Drug Administration (FDA). “While we support this area of scientific discovery, it’s important to note that FMT does not come without risk,” Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, says in a brief statement on the agency’s website. Marks does not state how many clinical trials will be affected, but says it was “not just a few.”
The FDA warns that fecal matter should be tested for drug-resistant bacteria. Today’s safety communication underscores the importance of why new therapies are thoroughly studied to ensure the benefits of taking them outweigh the risks to patients, and they will continue to aggressively monitor clinical trials to ensure patients are protected when safety concerns arise.

Comment by Dr. Krishna Kumari Challa on May 29, 2019 at 7:52am

Severe air pollution can cause birth defects, deaths

Researchers from Texas A&M University have determined that harmful particulate matter in the atmosphere can produce birth defects and even fatalities during pregnancy using the animal model.

The team of researchers from Texas A&M's Colleges of Agriculture and Life Sciences and Geosciences, the Texas A&M Health Science Center, and colleagues from the University of California-San Diego has had their findings published in the current issue of PNAS (Proceedings of the National Academy of Sciences).

Using female rats, the team examined the adverse health effects of exposure to fine particulate matter consisting of ammonium sulfate commonly found in many locations around the world. 

During winter months in China and India, where severe haze events frequently occur, fine particulate matter levels were especially high at several hundred micrograms per cubic meter, the team concluded.

Air pollution is a century-old problem for much of the world. According to the World Health Organization, 9 out of 10 people worldwide breathe air containing high level of pollutants, and 1 of every 9 global deaths can be attributed to exposure to air pollution, totaling over 7 million premature deaths a year.

Sulfate is mainly produced from coal burning, which is a major energy source for much of the world in both developed and developing countries. Ammonium is derived from ammonia, which is produced from agricultural, automobile, and animal emissions.

The results also show that prenatal exposure to air pollution may not dispose offspring to obesity in adulthood. Previous studies have shown such pollution to impair metabolic and immune systems in animal offspring, but this team's study shows definitive proof of decreased fetal survival rates, and also shortened gestation rates that can result in smaller body weight, in addition to damage to brains, hearts and other organs in the adult rat models.

Comment by Dr. Krishna Kumari Challa on May 25, 2019 at 9:07am

How Bacteria Become Drug-Resistant While Exposed to Antibiotics

Escherichia coli is capable of synthesizing drug-resistant proteins even in the presence of antibiotics designed to cripple cell growth. That’s the finding by a group of French researchers reporting on May 23 in Science. They also discovered how the bacteria manage this feat: a well-conserved membrane pump shuttles antibiotics out of the cell—just long enough to buy the cells time to receive DNA from neighbor cells that codes for a drug-resistant protein. 

Many bacterial membranes are known to harbor a multidrug efflux pump known as AcrAB-TolC, which is capable of shuttling a wide range of antibiotics out of cells. 

They found that the mutants, although they received the plasmid bearing the genetic code for TetA from neighboring cells, weren’t capable of synthesizing TetA protein. Without the functional efflux pump, the mutants can’t shuttle the tetracycline out of the cells. As levels of the antibiotic surged inside the cells, they could no longer make proteins or grow. 

When functional, the AcrAB-TolC pump buys the bacteria time by keeping antibiotic concentrations just low enough for the cells to synthesize the resistance proteins encoded in the plasmid DNA, according to the researchers. Ultimately, bacteria can become resistant while still under the influence of antibiotics. 

S. Nolivos et al., “Role of AcrAB-TolC multidrug efflux pump in drug-resistance acquisition by plasmid transfer,” Science, doi:10.1126/science.aax6620, 2019. 

• ‹ Previous
• 1
• 2
• 3
• …
• 226
• Next ›
• Page