KNOW A SCIENTIST

    Irving Millmanwas a noted virologist and microbiologist. He was a member of the U.S. Army's Eighth Armored Division during the Second World War, earning a Bronze Star. Millman's work with Baruch Blumberg helped lead to the creation of a test to detect hepatitis B. The test allowed blood banks to identify the hepatitis B virus in the blood of potential donors, thereby preventing the spread of the virus.

    Later research by the team led to a vaccine that is now commonly given to neonates. Millman and Blumberg found that the blood of individuals who carried the hepatitis B virus contained particles of the outside coating of the virus. The coating, hepatitis B surface antigen (HBsAg), is not infectious; however, HBsAG can provoke an immune response. In order to develop a vaccine, Millman and Blumberg developed a method of detaching the coatings from the virus.

Future climate models greatly affected by fungi and bacteria

(Image Credit: Johannes Rousk)

    Researchers from Lund University, Sweden, and USA have shown that our understanding of how organic material is decomposed by fungi and bacteria is fundamentally wrong. This means that climate models that include microorganisms to estimate future climate change must be reconsidered.

    When a plant dies, its leaves and branches fall to the ground. Decomposition of soil organic matter is then mainly carried out by fungi and bacteria, which convert dead plant materials into carbon dioxide and mineral nutrients.

    Until now, scientists have thought that high quality organic materials, such as leaves that are rich in soluble sugars, are mainly decomposed by bacteria. Lower quality materials, such as cellulose and lignin that are found in wood, are mainly broken down by fungi.

    Previous research has also shown that organic material that is broken down by fungi results in a reduced leakage of carbon dioxide and nutrients compared to material decomposed by bacteria.

    This has consequences for climate models, since more loss of carbon dioxide and mineral nitrogen would have a direct bearing on the soil's contribution to greenhouse gases and eutrophication.

    In a 23-year experiment, researchers from Lund University and USA have examined the relative significance of fungal and bacterial decomposition.

    "In contrast with expectations, there was no evidence that high quality organic material was mainly broken down by bacteria. In fact, the data strongly suggested the contrary," says Johannes Rousk, researcher in Microbial Ecology at Lund University in Sweden.

    "There was also no evidence to suggest that organic material broken down by fungi reduced the leakage of carbon dioxide into the atmosphere, or the leakage of nutrients. Once again, the results tended to suggest the contrary," says Johannes Rousk.

    The results could have consequences not only for future climate models, but may also impact current policies on land use intended to promote fungi. This may be based on flawed assumptions regarding the fungal role in reducing negative environmental effects.

Source: www.sciencedaily.com

Air pollution may increase Alzheimer's risk

    Higher levels of air pollution may increase risk of Alzheimer's disease in those who carry a gene associated with the debilitating brain disorder, suggests new research.

    The researchers detected detrimental impact of air pollution on cognitive abilities of children carrying a version of the apolipoprotein E gene (APOE) associated with the risk for Alzheimer disease (AD). 

    These results add to growing data suggesting APOE e4 carriers could have a higher risk of developing early AD if they reside in a polluted urban environment, and unfortunately this statement applies to individuals all around the world with high exposures to air pollutants regardless of ethnicity," said one of the researchers Lilian Calderon-Garciduenas, Professor at Universities of Montana in the US. 

Source: www.timesofindia.indiatimes.com

Excess vitamin A disrupts immune system

(Image Credit: V. Ganesan)

    Too much Vitamin A shuts down the body’s trained immunity, opening door to infections to which we would otherwise be immune, says a new study. According to the study, excess Vitamin A makes the body ‘forget’ past infections.

    The findings suggest that although Vitamin A supplementation can have profound health benefits when someone is deficient, supplementation of the vitamin above and beyond normal levels may have negative health consequences.

    Two different types of Vitamin A are found in the diet. While animal products such as meat, fish, poultry and dairy foods have preformed Vitamin A, plant-based foods such as fruits and vegetables contain the other type — Pro-Vitamin A.

    “This study helps to explain the mechanisms of anti-inflammatory effects of vitamin A and by doing so opens the door to identifying novel ways to modulate the immune response and restore its function in situations in which it is dis-regulated,” said one of the researchers Mihai Netea from the Radboud University Medical Center in Nijmegen, The Netherlands.

    To make this discovery, Netea and colleagues stimulated immune cells, isolated from volunteers, with Vitamin A and saw that the cells produced fewer cytokines, key proteins that help ward off microbes, upon stimulation with various mitogens and antigens.

    Furthermore, the cells were also stimulated with various microbial structures, which resulted in long-term activation or training of the cells.

    When the same experiments were performed in the presence of vitamin A, the microbial structures were no longer able to activate the immune cells.

    The study was published in the Journal of Leukocyte Biology.

Source: www.thehindu.com