Science Simplified!

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Comment by Dr. Krishna Kumari Challa on December 16, 2015 at 5:42am

Here is some interesting news: We all know that female mosquitoes spread diseases while having their meals. But you can avoid them in certain conditions. One of is to understand and follow their behaviour ...

A temperature-sensitive receptor prevents mosquitoes from being attracted to targets that are hotter than a potential host. Yes, true!

From warm summer days to cold winter nights, temperature is a ubiquitous sensory stimulus. All animals rely on their ability to detect environmental temperatures to avoid harm and to seek out more optimal conditions. Some animals, such as mosquitoes, also use their temperature sensors for a more nefarious purpose: to locate warm prey for a blood meal. Roman Corfas and Leslie Vosshall (e-Life) from Rockefeller University recently reported on the molecular basis of temperature-sensing behavior in Aedes aegypti, the mosquito that spreads yellow fever. They have shown how avoiding high temperatures can stop these insects from being attracted to targets that are too hot to represent a suitable host: in other words, while these mosquitoes like it hot, they don’t like it too hot.

Molecular receptors  guide the movements of some in the animal world like fruit flies and mosquitoes. In the malaria-spreading mosquito Anopheles gambiae, TRPA1 is expressed at the tips of the antennae. The tip of a mosquito antenna houses very sensitive thermoreceptors that could help drive host-seeking behavior.

Female mosquitoes normally prefer temperatures around 23°C. However, a puff of carbon dioxide (which could indicate that a metabolically active host is nearby) drives the mosquitoes to seek out temperatures that are closer to the body temperature of a mammal or bird (that is, between about 37°C and 43°C).  Corfas and Vosshall started by further characterizing this heat-seeking behavior. They found that mosquitoes were strongly attracted to a target when it was heated to temperatures above ambient, but only up to ~50°C. When it got hotter, this attraction declined strongly.

To probe the molecular mechanisms that might control this response, Corfas and Vosshall exploited genome-editing techniques to knock out the genes for GR19 and TRPA1 in A. aegypti. They found that mosquitoes lacking GR19 behaved like wild type mosquitoes and showed normal responses to heat. However, mosquitoes without TRPA1 continued to be attracted to the target even when its temperature reached potentially harmful levels (> 50°C).

The ability of animals to avoid high temperatures is commonly viewed from the perspective of damage avoidance. This response could also help a heat-seeking mosquito to choose among multiple potential targets.

As mosquito-borne illnesses kill more than a million people every year, interventions that can reduce the spread of such diseases are crucial. It is hoped that an increased understanding of how mosquitoes target their hosts can help accelerate the development of new control strategies.

Source: eLife Sciences

Comment by Dr. Krishna Kumari Challa on December 15, 2015 at 7:36am

We welcome climate pact to battle global warming at Paris.

The new accord, embraced by 195 nations, aims to cap warming to "well below" two degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels, and to "pursue efforts" to limit the increase to 1.5C.

But according to scientists ... this ambitious temperature goal is not matched by an equally ambitious mitigation goal - the scientific term for the drawing-down of heat-trapping gases.

To have a two-thirds chance of limiting warming to two degrees, emissions would have to fall by 40-70 percent by mid-century, according to the Intergovernmental Panel on Climate Change (IPCC), the UN`s climate science body.

And to reach the 1.5C target also embraced in the newborn pact, those mid-century cuts would have to be even deeper: 70 to 95 percent.

Without these hard numbers -- dropped from an earlier draft -- the climate pact does not send a clear signal about the level and timing of emissions cuts.

Many scientists highlighted the imbalance created by boosting the ambition of the temperature target on the one hand, while removing the yardsticks against which progress toward that goal could be measured, on the other. How are we going to reach our objective unless we set out in the right direction? What matters more is how to get to the target.

Until governments accept this, we should restrain our optimism.

Scientific reality is unyielding. Stabilising greenhouse gases "in the second half of this century will require net carbon dioxide emissions to be reduced, in effect, to zero! scientists voiced concern about the fact that the new accord allows several years to pass before ramping up emissions reduction efforts.

We can`t wait until 2020 -- acting before then is essential, we have to be very pro-active, according to climate scientists.

Comment by Dr. Krishna Kumari Challa on December 13, 2015 at 11:13am

Comment by Dr. Krishna Kumari Challa on December 11, 2015 at 6:08am

There’s only so much brainpower to go around, and when the eyes hog it all, the ears suffer. When challenged with a tough visual task, people are less likely to perceive a tone, scientists report in the Dec. 9 Journal of Neuroscience. The results help explain what parents of screen-obsessed teenagers already know. For the study, people heard a tone while searching for a letter on a computer screen. When the letter was easy to find, participants were pretty good at identifying a tone. But when the search got harder, people were less likely to report hearing the sound, a phenomenon called inattentional deafness. Neural responses to the tone were blunted when people worked on a hard visual task, but not when the visual task was easy, researchers found. By showing that a demanding visual job can siphon resources away from hearing, the results suggest that perceptual overload can jump between senses.

Comment by Dr. Krishna Kumari Challa on December 10, 2015 at 6:14am

New light on introversion and extroversion personality traits:

Dr. Scott Barry Kaufman, Scientific Director at the Imagination Ins... from Quiet on Vimeo.

Comment by Dr. Krishna Kumari Challa on December 10, 2015 at 5:53am

Molecule that improves learning capabilities has been identified

Neuroscience: The compound D-cycloserine enhances cellular changes in the brain that lead to learning.

Our interactions with the world around us strengthen and weaken the connections between our neurons, a process that neuroscientists consider to be the cellular mechanism of learning.

Now researchers report that boosting signaling of a certain receptor in the brain with a small molecule can enhance these cellular changes and improve learning in people. The findings could lead to new treatments for patients with disorders associated with deficits in learning, such as Alzheimer’s disease and schizophrenia.

Through decades of research on how synapses change in animal brains, scientists have found that the N-methyl-d-aspartate receptor (NMDAR) plays a critical role in strengthening synapses during learning. Compounds that increase NMDAR signaling can drive such changes and, as a result, help animals learn new tasks.

http://www.pnas.org/content/early/2015/11/24/1509262112

Comment by Dr. Krishna Kumari Challa on December 9, 2015 at 12:52pm

The 2014 hypertension guidelines: implications for patients and practitioners in Asia
Hypertension is a global public health issue and a major cause of morbidity and mortality. Because of population growth and ageing, the number of people with uncontrolled hypertension rose from 600 million in 1980 to nearly 1 billion in 2008. Furthermore, the number of adults with hypertension in 2025 has also been predicted to increase by about 60% to a total of 1.56 billion. The prevalence of hypertension in most Asian countries has increased over the last 30 years and more dramatically in the last 10 years. Several factors contributed to such changes in Asia, but acculturation to Western lifestyle, modernisation and urbanisation are considered key contributing factors. There are some unique features in regards to cardiovascular risk in Asia. Specifically, Asian regions have disproportionately higher mortality and morbidity from stroke compared with Western countries. Furthermore, the relationship between blood pressure level and risk of stroke is stronger in Asia than in Western regions. Although evidence-based and qualified guidelines for hypertension diagnosis and management have been released recently from Europe and North America, the unique features of Asian patients with hypertension raise concerns in regards to the real clinical applicability of Western guidelines in Asian populations. Specifically, it is not yet clear to what extent the new blood pressure target proposed by Western guidelines for high risk and elderly hypertensive individuals apply to Asian populations.
European and North American blood pressure guidelines, issued last year, may actually boost the stroke risk if used for Asian patients, particularly the elderly, suggested an expert opinion published online in Heart Asia. High blood pressure is a key risk factor for stroke, but the link between the two is much stronger in Asians than it is in Europeans or North Americans, said the experts. The global number of people with poorly controlled high blood pressure has risen from 600 million in 1980 to almost 1 billion in 2008, and predicted to rise a further 60 percent to 1.56 billion by 2025. The prevalence of high blood pressure in Asian countries has risen sharply in the past 30 years, and particularly over the past decade, as a result of increasing urbanization and the adoption of a Western lifestyle. High blood pressure among Asian populations has unique features in terms of the response to drug treatment, risk of complications, and outcomes, say the authors. This leads to disproportionately high rates of death and ill health from stroke compared with Western populations. “Although evidence-based and qualified guidelines have been recently released from Europe and North America, the unique features of Asian hypertensive patients raise concerns on the real clinical applicability of these guidelines to Asian populations,” wrote the authors. The latest Western guidelines increased target blood pressure to 140/90 mmHg for patients at high risk of cardiovascular disease and renal failure, but this may be too high for Asian populations warn, the authors. Some Asian guidelines have recommended more stringent targets in these patients, they said. Treating high blood pressure in elderly Asian patients is particularly challenging, they said. And the threshold for systolic blood pressure recommended by Western guidelines could boost the risk of stroke in these patients. A threshold below 140/90 mmHg might be more appropriate, they suggest. “The paucity of data on the correct definition of the most appropriate [blood pressure] target in elderly patients, highlighted by the few available trials, should be perceived as a stimulus for future research in Asia, not as an argument for questioning the benefit of treatment,” the researchers wrote.
http://heartasia.bmj.com/content/7/2/21

Comment by Dr. Krishna Kumari Challa on December 8, 2015 at 5:55am

Rattan wood — the stems of a climbing palm that grows in South-East Asian and West African forests — could be the source of next-generation bone implants, with the first products planned for release in 2019.

Italian firm GreenBone announced last month that trials on sheep prove that its technology works. It found that rattan can be used to build a scaffold to support damaged bones by turning rattan into a material with the same strength, flexibility and porosity as bones.

“Rattan is totally biocompatible and absorbable, and structurally organised like natural bone... it induces bone regeneration.”

The chemical process that turns rattan into a bone-like material was developed by a team at the Institute of Science and Technology for Ceramics (Istec) of the Italian National Research Council. Through this process, plant materials such as lignin and cellulose are removed from pieces of rattan wood, which are then treated to create hydroxyapatite, the same mineral that makes up human bones.

“The advantages offered by rattan-derived bone-like material over other bone substitutes like ceramics, polymers and titanium are great,” says Anna Tampieri, a researcher with the Istec project and chief scientist at GreenBone “Unlike these solutions, rattan is totally biocompatible and absorbable, and structurally organised like natural bone. We also already had evidence that it induces bone regeneration. With time, it will completely fuse with the real bone.”

Bone replacement is crucial for treating various conditions when bones cannot self-repair. These include severe breaks, bone cancer and degenerative diseases such as osteoporosis.

Rattan bones could be especially important for replacing large chunks of bone — three centimetres or more — for which existing bone substitutes are unsuitable, the team found. In time, rattan grafts are replaced with newly formed bone without needing further surgery, making it a cheaper and less-invasive choice for long-term treatment, the researchers say.

Pilot studies by Tampieri’s team showed evidence of full integration with real bone and no signs of rattan bones being rejected or leading to infection.
http://www.scidev.net/global/r-d/news/rattan-wood-bone-implants-nea...

http://www.inbar.int/forest-femur

http://news.bbc.co.uk/2/hi/europe/8446637.stm

Comment by Dr. Krishna Kumari Challa on December 7, 2015 at 5:31am

How scientists are trying to protect coral reefs

Comment by Dr. Krishna Kumari Challa on December 4, 2015 at 7:36am

Event Horizon Telescope Reveals Magnetic Fields at Milky Way's Central Black Hole

The supermassive black holes at the centers of galaxies are more like cosmic engines, converting energy from infalling matter into intense radiation that can outshine the combined light from all surrounding stars. If the black hole is spinning, it can generate strong jets that blast across thousands of light-years and shape entire galaxies. These black hole engines are thought to be powered by magnetic fields. For the first time, astronomers have detected magnetic fields just outside the event horizon of the black hole at the center of our Milky Way galaxy.
A new study results appear in the Dec. 4th issue of the journal Science.
These magnetic fields have been predicted to exist, but no one has seen them before.
This feat was achieved using the Event Horizon Telescope (EHT) – a global network of radio telescopes that link together to function as one giant telescope the size of Earth. Since larger telescopes can provide greater detail, the EHT ultimately will resolve features as small as 15 micro-arcseconds. (An arcsecond is 1/3600 of a degree, and 15 micro-arcseconds is the angular equivalent of seeing a golf ball on the moon.)
The Event Horizon Telescope made observations at a wavelength of 1.3 mm. The team measured how that light is linearly polarized. On Earth, sunlight becomes linearly polarized by reflections, which is why sunglasses are polarized to block light and reduce glare. In the case of Sgr A*, polarized light is emitted by electrons spiraling around magnetic field lines. As a result, this light directly traces the structure of the magnetic field.

Sgr A* is surrounded by an accretion disk of material orbiting the black hole. The team found that magnetic fields in some regions near the black hole are disorderly, with jumbled loops and whorls resembling intertwined spaghetti. In contrast, other regions showed a much more organized pattern, possibly in the region where jets would be generated.

They also found that the magnetic fields fluctuated on short time scales of only 15 minutes or so.

“Once again, the galactic center is proving to be a more dynamic place than we might have guessed. Those magnetic fields are dancing all over the place.”

https://www.cfa.harvard.edu/news/2015-28

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