Monday, February 21, 2011

WA'S INCREDIBLE UNDERGROUND ORCHID

0 comentarios

Rhizanthella gardneri is a cute, quirky and critically endangered orchid that lives all its life underground. It even blooms underground, making it virtually unique amongst plants.

Last year, using radioactive tracers, scientists at The University of Western Australia showed that the orchid gets all its nutrients by parasitising fungi associated with the roots of broom bush, a woody shrub of the WA outback.

Now, with less than 50 individuals left in the wild, scientists have made a timely and remarkable discovery about its genome.

Despite the fact that this fully subterranean orchid cannot photosynthesise and has no green parts at all, it still retains chloroplasts - the site of photosynthesis in plants.

"We found that compared with normal plants, 70 per cent of the genes in the chloroplast have been lost," said Dr Etienne Delannoy, of the ARC Centre for Excellence in Plant Energy Biology, the lead researcher of a study published in Molecular Biology and Evolution. "With only 37 genes, this makes it the smallest of all known plant chloroplast genomes."

"The chloroplast genome was known to code for functions other than photosynthesis, but in normal plants, these functions are hard to study," said ARC Centre Director Professor Ian Small.

"In Rhizanthella, everything that isn't essential for its parasitic lifestyle has gone. We discovered that it has retained a chloroplast genome to make only four crucial proteins.

Our results are relevant to understanding gene loss in other parasites, for example, the Plasmodium parasite that causes malaria."

Associate Professor Mark Brundrett from the Wheatbelt Orchid Rescue Project describes Rhizanthella as one of the most beautiful, strange and iconic orchids in the world.

"Combining on-the-ground conservation efforts with cutting edge laboratory technologies has led to a great discovery with impacts for both science and conservation. The genome sequence is a very valuable resource, as it makes it possible to estimate the genetic diversity of this Declared Rare plant".

Professor Brundrett has been working with the Department of Environment and Conservation and volunteers from the West Australian Native Orchid Study and Conservation Group to locate these unique orchids.

"We needed all the help we could get since it often took hours of searching under shrubs on hands and knees to find just one underground orchid!"

(Photo: UWA)

The University of Western Australia

LACK OF SLEEP FOUND TO BE A NEW RISK FACTOR FOR COLON CANCER

0 comentarios
In a ground-breaking new study published in the Feb. 15, 2011 issue of the journal Cancer, researchers from University Hospitals (UH) Case Medical Center and Case Western Reserve University School of Medicine, found that individuals who averaged less than six hours of sleep at night had an almost 50 percent increase in the risk of colorectal adenomas compared with individuals sleeping at least seven hours per night. Adenomas are a precursor to cancer tumors, and left untreated, they can turn malignant.

"To our knowledge, this is the first study to report a significant association of sleep duration and colorectal adenomas," said Li Li, MD, PhD, the study's principal investigator, family medicine physician in the Department of Family Medicine at UH Case Medical Center and Associate Professor of Family Medicine, Epidemiology and Biostatistics at Case Western Reserve University School of Medicine. "A short amount of sleep can now be viewed as a new risk factor for the development of the development of colon cancer."

In the study, patients were surveyed by phone prior to coming into the hospital for scheduled colonoscopies at UH Case Medical Center. They were asked demographic information as well as questions from the Pittsburg Sleep Quality Index (PSQI), which obtains information about the patient's overall sleep quality during the past month. The PSQI asks for such information as how frequently one has trouble sleeping and how much sleep one has had per night. The study was funded by the National Cancer Institute through Case Western Reserve University School of Medicine.

Of the 1,240 patients, 338 were diagnosed with colorectal adenomas at their colonoscopy. The patients with adenomas were found in general to have reported sleeping less than six hours compared to compared to those patients without adenomas (control) patients, and the association between amount of sleep and adenomas remained even when adjusted for family history, smoking, and waist-to-hip ratio (a measurement of obesity).

The researchers also found a slightly stronger association of sleep duration with adenomas with women compared to men, but the difference was not statistically significant.

Dr Li said the magnitude of the increase in risk due to less hours of sleep is comparable to the risk associated with having a first-degree relative (parent or sibling) with colon cancer, as well as with high, red meat intake. "Short sleep duration is a public health hazard leading not only to obesity, diabetes and coronary heart disease, but also, as we now have shown in this study, colon adenomas," he said. "Effective intervention to increase duration of sleep and improve quality of sleep could be an under-appreciated avenue for prevention of colorectal cancer."

Although why fewer hours of sleep may lead to colon cancer is unknown, Dr. Li said some of theories include that less sleep may mean less production of melatonin, a natural hormone that in animals has been linked to DNA repair, or that insulin resistance may underlie the link between sleep disturbance and cancer development.

University Hospitals Case Medical Center

CROCODILE TEARS DON'T FOOL US ALL

0 comentarios
How easy is it to fake remorse? Not so easy if your audience knows what to look for. In the first investigation of the nature of true and false remorse, Leanne ten Brinke and colleagues, from the Centre for the Advancement of Psychology and Law (CAPSL), University of British Columbia and Memorial University of Newfoundland in Canada, show that those who fake remorse show a greater range of emotional expressions and swing from one emotion to another very quickly - a phenomenon referred to as emotional turbulence - as well as speak with more hesitation.

These findings have important implications for judges and parole board members, who look for genuine remorse when they make their sentencing and release decisions. Ten Brinke's work is published in Springer's journal Law and Human Behavior.

Deception is a common aspect of human social interaction that can have major implications if undetected, particularly in the context of crime sentencing and parole hearings, where the perceived credibility of the defendants' emotion during their testimony informs decisions about their future.

Ten Brinke and colleagues examined the facial, verbal and body language behaviors associated with emotional deception in videotaped accounts of true personal wrongdoing, with either genuine or fabricated remorse, among 31 Canadian undergraduate students. Their analysis of nearly 300,000 frames showed that those participants who displayed false remorse displayed more of the seven universal emotions (happiness, sadness, fear, disgust, anger, surprise, and contempt) than those who were genuinely sorry.

The authors grouped the emotions displayed in facial expressions into three categories: positive (happiness), negative (sadness, fear, anger, contempt, disgust) and neutral (neutral, surprise). They found that participants who were genuinely remorseful did not often swing directly from positive to negative emotions, but went through neutral emotions first. In contrast, those who were deceiving the researchers made more frequent direct transitions between positive and negative emotions, with fewer displays of neutral emotions in between. In addition, during fabricated remorse, students had a significantly higher rate of speech hesitations than during true remorse.

The authors conclude: "Our study is the first to investigate genuine and falsified remorse for behavioral cues that might be indicative of such deception. Identifying reliable cues could have considerable practical implications - for example for forensic psychologists, parole officers and legal decision-makers who need to assess the truthfulness of remorseful displays."

Springer

Followers

Archive

 

Selected Science News. Copyright 2008 All Rights Reserved Revolution Two Church theme by Brian Gardner Converted into Blogger Template by Bloganol dot com