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Comment by Dr. Krishna Kumari Challa on November 5, 2015 at 8:25am

Controlling mosquitoes the natural way: Insect-control experts are now hoping that deploying the laboratory mosquitoes will eventually slash the number of wild mosquitoes in people’s neighbourhoods.
A new plan to release thousands of mosquitoes in people's backyards in Los Angeles is underway. The bugs—all males—would not bite humans like females do, and area officials hoped these particular insects would block further reproduction of their kind. To some local residents the approach seemed a bit counterintuitive at first. Yet they were told the method would help curb pesticide use while simultaneously beating back their mosquito population.

The bugs to be released were not genetically modified. But they were not exactly garden-variety mosquitoes, either. The male mosquitoes were raised in a laboratory where they were infected with Wolbachia, a natural bacterium that would effectively sterilize them. When the males are released into people’s backyards and mate with wild females, the resulting eggs—for reasons not yet fully understood—simply will not hatch, leading to fewer mosquitoes.
The biology of how Wolbachia interact with their hosts is a bit complex. If a male mosquito with Wolbachia mates with an uninfected female, then their eggs will not hatch. That is the key to Dobson’s approach. Yet if two mosquitoes that both have Wolbachia mate, then their resulting eggs will hatch as normal, although the offspring will potentially harbor Wolbachia. Basically, their lives will go on as usual and they will be able to reproduce. Similarly, if an infected female mates with an uninfected male, then their resulting eggs will also hatch as normal—although again, the offspring will potentially also be infected.

This is not the first time Wolbachia has been auditioned as a way to hamper the spread of mosquito-borne diseases—scientists have previously used a strain of the bacterium to curb the spread of dengue.
- Scientific American

Comment by Dr. Krishna Kumari Challa on November 5, 2015 at 7:10am

Effects of an AC or DC Currents on the Human Body

The three basic factors that determine what kind of shock you experience are the amplitude of the current, the duration of the current passing through the body, and the frequency.
Direct Currents actually have zero frequency, as the current is constant. However, there are physiological effects during electrocution no matter what type of current.
The factor deciding the effects of the AC and DC current is the path the current takes through the body. If it is from the hand to the foot, it does not pass through the heart, and then the effects are not so lethal.
However DC current will make a single continuous contraction of the muscles compared to AC current, which will make a series of contractions depending on the frequency it is supplied at. In terms of fatalities, both kill but more milliamps are required of DC current than AC current at the same voltage.
If the current takes the path from hand to hand thus passing through the heart it can result in fibrillation of the heart. Fibrillation is a condition when all the heart muscles start moving independently in a disorganized manner rather than in a state of coordination. It affects the ability of the heart to pump blood, resulting in brain damage and eventual cardiac arrest.
Either AC or DC currents can cause fibrillation of the heart at high enough levels. This typically takes place at 30 mA of AC (rms, 60 Hz) or 300 – 500 mA of DC.
Though both AC and DC currents and shock are lethal, more DC current is required to have the same effect as AC current. For example, if you are being electrocuted or shocked 0.5 to 1.5 milliamps of AC 60 Hz current is required and up to 4 mA of DC current is required. For the let-go threshold in AC a current of 3 to 22 mA is required against 15 to 88 of DC current.

Comment by Dr. Krishna Kumari Challa on November 5, 2015 at 7:08am

In direct current electrons flow in one and only one direction (zero frequency). So if you happen to close the circuit by any kind of physical contact forming a low resistance path, the current would start flowing through you. In other words you will be stuck to the conductor as if you just held onto a super.... duper glue. In the meanwhile all your muscles would contract and the heart would stop beating because of the contraction plus there would be other major burns. Eventually you'll die!!
In DC the body just contracts once touched, but in AC the power is made up of frequencies of currents with highs and lows. Thus the body if touched would experience series of contractions depending on the frequency of power. That is like multiple dc shocks in a small gap, and that too the current flows in both directions alternatively. So yes, this kind of shock would totally destroy your muscles. But yeah, if you are lucky enough you can detach yourself from the circuit when the current reaches its 0 and changes direction.

But both AC and DC are lethal.

Comment by Dr. Krishna Kumari Challa on November 5, 2015 at 6:15am

Specialized Cells Help Each Other Survive During Times of Stress
A team led by scientists from the Florida campus of The Scripps Research Institute (TSRI) and the University of Pittsburgh has shown for the first time how one set of specialized cells survives under stress by manipulating the behavior of key immune system cells.

The new study, published recently in the journal Nature Communications, involved mesenchymal stem cells—which live in bone marrow and can differentiate into several different cell types used in bone and connective tissue—and macrophages—immune cells that usually respond to infectious agents or damaged cells by engulfing and devouring them.

“This is the first time anyone has shown how mesenchymal stem cells provide for their own survival by recruiting and then suppressing normal macrophage activity,” said TSRI Professor Donald G. Phinney, who led the study with University of Pittsburgh Associate Professor Luis A. Ortiz. “This finally puts the crosstalk between these cells into the context of cell survival.”

The team’s experiments showed that, like all other cells, mesenchymal stem cells experience stress due to tissue injury and inflammation. When this stress results in damage to the mitochondria (the power houses of the cell), the mesenchymal stem cells recruit the immune system’s macrophages—but in an unusual way.

By reengineering macrophage action with secreted microRNA, the stem cells protect themselves from being targeted and instead package their damaged mitochondria into small sacs known as vesicles and send them out to be engulfed by the macrophage.

Once macrophages subsume the damaged mitochondria, the macrophages are able to repurpose the mitochondria for their own use, replenishing their own energy supplies. Blocking the exchange of damaged mitochondrial to macrophages causes death of the stem cells. Therefore, the process is mutually beneficial.
http://www.nature.com/ncomms/2015/151007/ncomms9472/full/ncomms9472...

Comment by Dr. Krishna Kumari Challa on November 1, 2015 at 12:08pm

Comment by Dr. Krishna Kumari Challa on November 1, 2015 at 11:49am

Comment by Dr. Krishna Kumari Challa on October 31, 2015 at 8:53am

A new study from scientists at The Scripps Research Institute (TSRI) helps explain why cancer metastasis is so hard to stop. The researchers found an additional mechanism explaining how a molecule long linked to cancer progression appears to “seed” the body with metastatic cells long before doctors would typically detect a primary tumor. The molecule, known as epidermal growth factor receptor (EGFR), encourages blood vessel growth early in tumor development—not only feeding the primary tumor, but also providing vehicles for cancer to escape the primary tumor site and travel throughout the body.

“When cancer cells have high levels of EGFR, the tumor has a lot of new, angiogenic blood vessels,” said TSRI Assistant Professor Elena Deryugina, senior author of the new study. “And these vessels are very welcoming for tumor cells and facilitate their dissemination from the very early stages of tumor development.”

The study was published recently in the journal Neoplasia.
When we downregulated EGFR so it wasn’t expressed anymore, the tumor cells were not able to disseminate efficiently,” said TSRI Research Associate Petra Minder, who was first author of the new study. “This gave us a hint that EGFR plays a role in intravasation [an early step of metastatic dissemination during which tumor cells enter angiogenic blood vessels]—we were just not sure how.

The new study shows how EGFR levels make a difference. In experiments using chick embryos, the researchers found that EGFR signaling starts a chain reaction inside tumor cells, ultimately resulting in the release of a molecule called vascular endothelial growth factor (VEGF), known to be active in almost all forms of solid tumors. Released VEGF then binds to endothelial cells, inducing the growth of new blood capillaries and vessels within a developing tumor.

For many years, scientists had seen small blood vessels growing in early-stage tumors, but it was thought these vessels were mostly for supplying tumors with oxygen and nutrients.

“Now we have learned that these newly formed vessels are used by tumor cells for dissemination because of their certain structural properties,” added Deryugina.

The new study shows that these vessels are actually useful for tumors because they are dilated and unusually permeable. Tumor cells can slip into the vessels, escape the primary tumor site and lodge throughout the body. Escaped cells often lie dormant or grow very slowly, not appearing as metastases until after the primary tumor is detected.

The results could also explain why EGFR-inhibiting drugs have had limited success in human patients. While these drugs target EGFR’s effects in primary tumor growth, they don’t address EGFR’s role in blood vessel growth and early metastatic seeding.
The researchers said the findings highlight the urgent need for new methods to diagnose cancers early and new treatments to fight growing metastases.
- http://www.neoplasia.com/article/S1476-5586%2815%2900098-6/abstract

Comment by Dr. Krishna Kumari Challa on October 30, 2015 at 9:19am

All our fears are coming true! Yes, now we hear about Plastic Contamination of Table Salt in China. Supermarket products have tiny plastic particles, probably from ocean pollution attached to sea salt.

People in China who season their meals with sea salt may be unwittingly consuming microscopic pieces of plastic pollution.

When researchers analyzed fifteen brands of common table salt bought at supermarkets across China, they found among the grains of seasoning micro-sized particles of the common water bottle plastic polyethylene terephthalate, as well as polyethylene, cellophane, and a wide variety of other plastics (Env. Sci.& Tech. 2015, DOI: 10.1021/acs.est.5b03163).

The highest level of plastic contamination was found in salt sourced from the ocean: The researchers measured more than 1,200 particles of plastic per lb of sea salt. The team, led by Huahong Shi of East China Normal University also found tiny particles of plastic in salt sourced from briny lakes, briny wells, and salt mines, although at lower levels—between 15 and 800 particles/ lb.

Shi and colleagues argue that plastic contamination originates from the vast amount of plastic pollution floating around marine environments where sea salt is sourced. For instance, bits of plastics might abrade from larger objects, such as water bottles, dumped in the water or they might come from cosmetic products, such as face washes, that use plastic microbeads as exfoliants. The researchers add that other points of entry for plastic contamination are also possible, including during salt processing, drying, and packaging.

Given that manufacturers typically extract sea salt from ocean water by evaporation—a process that leaves everything behind but water—microplastic contamination of sea salt is likely prevalent outside China as well.

Feeling Scary? Then stop using plastic and products made from it as much as possible.

Comment by Dr. Krishna Kumari Challa on October 29, 2015 at 8:42am

Centre for Cellular and Molecular Biology (CCMB) founder-director P M Bhargava on Wednesday became the first Indian scientist to join the bandwagon of writers and filmmakers returning their awards when he told TOI that he will return his Padma Bhushan to protest against "the government's attack on rationalism, reasoning and science".

Bhargava's decision came hours after 107 senior scientists signed an online statement on Wednesday to join the chorus of protests by other scientists, artists and writers.

"The Padma Bhushan had a special place in my collection of more than 100 awards for science. Now I feel no sentimental attachment to it when the government tries to institutionalise religion and curtail freedom and scientific spirit," said Bhargava, who received the Padma award in 1986. He said it was a personal decision and that he had no idea if other scientists would return their awards.

The Indian Constitution in Article 51 A (h) demands ... that we develop scientific temper, humanism and the spirit of inquiry and reform. Unfortunately, what we are witnessing instead is the active promotion of irrational and sectarian thought.

Declaring solidarity with writers who returned their Sahitya Akademi awards, the statement said, "We scientists now join our voices to theirs, to assert that the Indian people will not accept such attacks on reason, science and our plural culture."We appeal to all other sections of society to raise their voice against the assault on reason and scientific temper we are witnessing in India today. The scientists have not sent their statement to any government agency or minister. Rather, they want the government to take note of their protest after reading what the scientist community feels about the state of affairs. Many of the scientists, who are working in the government institutions, including the Delhi-based Indian National Science Academy (INSA), have similar views.

"We are very much with the fellow scientists who have raised the issue of growing intolerance," said a senior scientist of the INSA .

-Times of India

Comment by Dr. Krishna Kumari Challa on October 29, 2015 at 7:43am

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