Washington, Apr 20 : Exposure to marijuana or hashish during adolescence has a lasting impact on cognitive processes such as learning and memory, says a new study.

Lead researcher Dr. Peter Winsauer, from Louisiana State University suggests that illicit use of THC, an ingredient of marijuana or hashish, during adolescence produces persistent changes in the brain that sensitise females to the negative effects of THC later in life.

Washington, Apr 20 : Genetic variations in the micro-RNA (miRNA) processing pathway genes and miRNA binding sites could predict a woman''s risk of developing ovarian cancer and her prospects for survival, according to a new study.

The study by researchers from The University of Texas M. D. Anderson Cancer Centre was the first to examine the association of genetic variants related to miRNA with ovarian cancer risk, overall survival for ovarian cancer patients, and platinum-based chemotherapy response.

Washington, Apr 20 : Incorporating an omega three fatty acid- found in fish oil- in the diet could help prevent diseases like Parkinson''s and Huntington''s.

Dr. Nicolas Bazan, form the Louisiana State University Health Sciences Center, showed that the omega three fatty acid, docosahexaenoic acid (DHA), prevented the misfolding of a protein resulting from a gene mutation in neurodegenerative diseases.

For the study, researchers developed a cell model with a mutation of the Ataxin-1 gene.

Washington, Apr 20 : A simple urine test could predict if a smoker is at the risk of developing lung cancer or not, according to a new study.

Lung cancer afflicts some smokers and not others, and now University of Minnesota researchers have hypothesised that the presence of the metabolite NNAL in a patient''s urine might predict risk of lung cancer.

Washington, April 20 : An international team of scientists has reported an innovative method for controlling light on the nanoscale by adopting tuning concepts from radio-frequency technology, which opens the door for antenna-based applications, including highly sensitive biosensors and extremely fast photodetectors.

These applications could play an important role in future biomedical diagnostics and information processing.

An antenna is a device designed to transmit or receive electromagnetic waves.

Radio frequency antennas find wide use in systems such as radio and television broadcasting, point-to-point radio communication, wireless LAN, radar, and space exploration.

Washington, April 20 : A new report has determined that climate change and major water conservation projects are a major risk to the long-term "health" of the Yangtze River in China.

The Yangtze Conservation and Development Report 2009, compiled by the China Academy of Science (CAS), states the basin of China's longest waterway has been hit by a yearly reduction in rain since 2006, brought on by global warming.