26 Aug 2012

Stem cells blamed for tumor re-growth



Stem cells are viewed on a computer screen. Researchers presented evidence Wednesday for the existence of cancer stem cells, with three different studies seeking to end a decades-old scientific dispute about how tumours grow. (AFP Photo/)
Researchers presented evidence Wednesday for the existence of cancer stem cells, with three different studies seeking to end a decades-old scientific dispute about how tumours grow.

The discovery should lead to new drugs targeting stem cells that cause tumours to reappear after cancer therapy, the teams argued in three scientific papers published simultaneously in the journals Nature and Science.

25 Aug 2012

ICMR JRF 2012 Marks Publicized



INDIAN COUNCIL OF MEDICAL RESEARCH
V.RAMALINGASWAMI BHAWAN
ANSARI NAGAR, NEW DELHI 110029

NOTIFICATION

RESULT OF ICMR/JRF ENTRANCE EXAMINATION- 22nd July, 2012


CSIR June 2012 Marks Publicized




Examination Unit, Human Resource Development Group,
CSIR Complex, Opposite Institute of Hotel Management, Library Avenue, Pusa, New Delhi 110012

RESULT OF THE JOINT CSIR-UGC TEST FOR JUNIOR RESEARCH FELLOWSHIP (JRF) AND ELIGIBILITY FOR LECTURESHIP NET) HELD ON 17-06-2012


24 Aug 2012

Research on Wood Formation Sheds Light on Plant Biology

Sequoya. Scientists at North Carolina State University have discovered a phenomenon never seen before in plants while studying molecular changes inside tree cells as wood is formed.


Scientists at North Carolina State University have discovered a phenomenon never seen before in plants while studying molecular changes inside tree cells as wood is formed.

In research published online in Proceedings of the National Academy of Sciences the week of Aug. 20, the team found that one member of a family of proteins called transcription factors took control of a cascade of genes involved in forming wood, which includes a substance called lignin that binds fibers together and gives wood its strength.

The controller protein regulated gene expression on multiple levels, preventing abnormal or stunted plant growth. And it did so in a novel way.

The controller, a spliced variant of the SND1 family, was found in the cytoplasm outside the cell nucleus. This is abnormal, because transcription factor proteins are always in the nucleus. But when one of the four other proteins in its family group was present, the spliced variant was carried into the nucleus, where it bound to the family member, creating a new type of molecule that suppressed the expression of a cascade of genes.

“This is nothing that’s been observed before in plants,” says Dr. Vincent Chiang, co-director of NC State’s Forest Biotechnology Group with Dr. Ron Sederoff. Chiang’s research team was the first to produce a transgenic tree with reduced lignin. High lignin levels are desirable for lumber, but lignin is removed during the process of making paper or manufacturing biofuels.

Chiang, a professor in the College of Natural Resources, described the team’s finding as the long-sought path to understanding the hierarchy of gene regulation for wood formation.

Lead authors are Dr. Quanzi Li, senior research associate, who discovered the controller protein, and doctoral student Ying-Chung Lin, who carried out extensive experimental work, demonstrating with Li that the controller protein was carried into the nucleus.

Gene advance may possibly improvement rice yields by 20%

A Nepalese farmer walks past rice paddy fields at Khokana village on the outskirts of Kathmandu in July 2012. Scientists said they had developed a strain of rice that grows well in soils that lack the nutrient phosphorus, a feat that could boost crop yields for some farmers by as much as a fifth. (AFP Photo/Prakash Mathema)


Scientists on Wednesday said they had developed a strain of rice that grows well in soils lacking the nutrient phosphorus, a feat that could boost crop yields for some farmers by as much as a fifth.

The announcement ends a quest to pinpoint a mystery gene that helps the roots of baby rice plants tease phosphorus from the soil, enabling them to notch up strong, early growth.

The gene has now been transferred to modern varieties of rice using classic methods of cross-breeding, not genetic engineering, said Sigrid Heuer at the International Rice Research Institute (IRRI) in the Philippines.

Next week, national rice breeders from Bangladesh, India, Thailand and India will be briefed on the exciting find, which should benefit small farmers most of all, Heuer said in a phone interview from Manila.

"I would expect to see (an improvement in yield of) around 20 percent, but it depends so much on the type of the soil and how severe the stress is," Heuer said.

"But realistically, we are talking conservatively of an average of 10-20 percent, and locally a little more if the (phosphorus) stress is severe," she said.

The breakthrough seeks to address one of the biggest problems facing rice growers from the southeastern United States to South America, Southeast Asia and China.

Many soil types bond tightly to phosphorus, surrendering only a tiny amount of the precious mineral to plant roots.

To get around this, farmers look to phosphorus fertilisers which are spread on the field.

But in poorer countries, this option is often too costly, which means the plant is left undernourished at a stage when it is in competition with weeds. Ultimately this meagre growth affects yields when the plant matures.

The search for PSTOL-1 -- for phosphorus-starvation tolerance 1 -- began in the late 1990s, when researchers were intrigued that a rice strain grown in India called Kasalath grew so well in phosphorus-deficient conditions.

But it took nearly a decade of further work, including a full sequencing of the strain's genome, to close in on the gene that does the magic.

"Over the last one-and-a-half to three years, we were pretty certain that we had the gene, but then we had to carry out a lot of experiments to confirm our findings," said Heuer.

Poor farmers, especially those in Southeast Asia and Bangladesh, could benefit most, she said.

But rice growers in richer countries could also save money as they would need less fertiliser, which would also mean less damaging phosphate runoff into groundwater and the sea.

The research, published in the journal Nature, marks the latest laboratory exploit for boosting rice yields. Other recent finds have been genes that help rice plants cope better with drought and saline soil.

Arguably the most important crop in the world, rice is under pressure from rising demographic growth and the impacts of climate change.

Last October, the UN Population Fund (UNFPA) said the global population of seven billion could rise to at least 10 billion by 2100, but could top 15 billion if birth rates are just slightly higher than expected.

Phosphate fertilisers are typically extracted from layers of rock that millions of years ago were ocean sediments.

The price of rock phosphate has more than doubled since 2007. According to a 2009 estimate, world supplies could run out in 50 to 100 years.

Two gene clues for resistance to malaria


A mosquito is prepared to be studied in a laboratory. Scientists in Germany and Africa on Wednesday said they had found two variants of genes that help to explain why some lucky individuals do not develop severe malaria. (AFP Photo/Luis Robayo)

Scientists in Germany and Africa on Wednesday said they had found two variants of genes that help to explain why some lucky individuals do not develop severe malaria.

The two variants were netted in a comparison of 1,325 people in the West African state of Ghana who had fallen ill with severe falciparum malaria and of 828 counterparts who were otherwise healthy.

One variant is found in a gene called ATP2B4, they reported in the journal Nature. The gene's function is to help the passage of calcium through the membrane of red blood cells, which are targeted for infection by the malaria parasite.

The other variant is located near a gene called MARVELD3, controlling a protein on the lining of blood vessels. The gene could play a part in reducing damage that occurs when colonized blood cells stick to tiny blood vessels, according to the research.

The results of the study, led by Christian Timmann of the Bernhard Nocht Institute for Tropical Medicine in Hamburg, Germany, were compared with a similar survey among children in Gambia.

A fast-growing tool in basic research, genomic comparison entails sifting through the human genetic code and looking for tiny changes that signify why some people are likelier to fall sick from disease and others less so or maybe not at all.

The goals are to provide diagnostic tools, helping to identify people who are at greater risk, and develop new drugs inspired by the pathways which confer immunity.

Previous work has found that people with the blood group O have a protection against falciparum malaria, the severest form of the disease.

People with sickle-cell disorder, in which blood cells with an abnormal sickle shape can trigger anaemia, have also been found to be resistant to malaria.

In 2010, malaria infected about 216 million people and claimed an estimated 655,000 lives, particularly in Africa and among small children, according to the UN's World Health Organization (WHO). Other experts’ say the toll is at least double that estimate.


19 Aug 2012

What’s New in CSIR December 2012 Exam?



Here are some important changes for CSIR JRF/NET December 2012 exam.

1. Change in the CSIR JRF /NET Syllabus for Part A

    Instead of General Science, Now Part A is GENERAL APTITUDE with emphasis on logical reasoning, graphical analysis, analytical and numerical ability, quantitative comparison, series formation, puzzles etc. Total Marks 40.

2. TWO years CSIR Validity : 1st April, 2013 with the validity period of 2 years for joining the fellowship under CSIR Scheme. Before it was 1year validity.


3. Engineering Sciences Subject Paper Introduced.

    Apart from 1. Chemical Sciences, 2. Earth, Atmospheric, Ocean and Planetary Sciences, 3. Life Sciences, 4. Mathematical Sciences, 5. Physical Sciences, now 6. Engineering Sciences subject paper introduced for engineering students.

    There is no Biotech syllabus for Engineering Sciences.

4. BE/BTech/BPharma Students are Eligible to write CSIR.

    For the First time, CSIR Clearly mentioned in December 2012 notification about BE/BTech/BPharma Students Eligibility for CSIR.

11 Aug 2012

Researcher Explains How Doddering Cells Can Hurt Us [Video]


Cells that lose the ability to proliferate gain some surprisingly toxic powers
By Ricki Rusting  | August 8, 2012
Judith Campisi
Image: Berkeley Lab

Cells that permanently stop dividing—that become “senescent”—have long been known to be a defense against cancer: if damaged cells can’t replicate, they can’t form tumors. Recently, though, investigators have learned that senescent cells can at times prod other cells to become malignant, as David Stipp notes in “Quiet Little Traitors,” in the August 2012 issue of Scientific American. Here, Judith Campisi, of the Buck Institute for Research on Aging, describes how senescent cells cause such havoc and how they can contribute, not only to cancer, but to an array of age-related ills. She also speculates on possible interventions.







See more: www.scientificamerican.com

1 Aug 2012

The Discovery of Reverse Transcriptase




For their discovery of the viral enzyme reverse transcriptase (RT), Howard Temin, David Baltimore, and Renato Dulbecco shared the 1975 Nobel Prize for Physiology or Medicine. Temin and Baltimore discovered this enzyme, also known as RNA-dependent DNA polymerase, at the same time, but independently of each other. Dulbecco took no direct part in their experiments, but it was he who had taught them the methods they used to make their discovery.

RT is an enzyme produced by retroviruses, which are RNA viruses that make DNA copies of themselves and then insert those copies into host chromosomes. It plays an essential role in the reproduction of these molecular parasites. Well-known examples of retroviruses that can infect human beings are the agents of such diseases as AIDS or herpes.

Some retroviruses - oncoviruses - cause normal cells to become cancerous. Dulbecco's lab was the first to demonstrate this fact. They showed that the infection of normal cells with oncoviruses leads to the insertion of viral genes into host-cell chromosomes, which in turn can cause the cell to transition to a state of uncontrolled growth that gives rise to a malignant tumor (cancer). Oncoviruses are the cause of some forms of human cancer. However, in order to replicate a retrovirus must make a DNA copy of itself and then insert that copy into a host chromosome.