Knowledge Update

Washington, Sep 24 (IANS) A NASA-funded sounding rocket to study the origin of X-rays in the universe has helped scientists reveal a new mystery - an entire group of X-rays that don't come from any known source.

Some of this invisible light that fills space takes the form of X-rays, the source of which has been hotly contended over the past few decades.

The DXL (Diffuse X-ray emission from the Local galaxy) sounding rocket was launched from White Sands Missile Range in New Mexico in 2012 to study the source of certain X-rays observed near Earth.

In a new study, DXL's data confirms some of our ideas about where these X-rays come from, thus strengthening our understanding of our solar neighbourhood's early history.

The two known sources of X-ray emission are the solar wind and the Local Hot Bubble - a theorised area of hot interstellar material that surrounds our solar system.

"We show that the X-ray contribution from the solar wind charge exchange is about 40 percent in the galactic plane, and even less elsewhere," said Massimiliano Galeazzi, astrophysicist at University of Miami.

"So the rest of the X-rays must come from the Local Hot Bubble, proving that it exists," he added.

However, DXL also measured some high-energy X-rays that could not possibly come from the solar wind or the Local Hot Bubble.

"At higher energies, these sources contribute less than a quarter of the X-ray emission," noted Youaraj Uprety, lead author and astrophysicist at University of Miami at the time the research was conducted. "So there's an unknown source of X-rays in this energy range."

"We think that around 10 million years ago, a supernova exploded and ionized the gas of the Local Hot Bubble," said Galeazzi.

But one supernova wouldn't be enough to create such a large cavity and reach these temperatures - so it was probably two or three supernova over time, one inside the other.

"Identifying the X-ray contribution of the Local Hot Bubble is important for understanding the structure surrounding our solar system," added Uprety who is now astrophysicist at Middle Tennessee State University.

It helps us build better models of the interstellar material in our solar neighbourhood, the authors noted in a paper published in the Astrophysical Journal.

​New York, Sep 24 (IANS) Fish oil which contains Omega-3 fatty acids helps to boost brain functions and acts as an anti-inflammatory within the body -- helping athletes and soldiers manage intense training better, finds a study.

Low concentration of fish oil in the blood and also lack of physical activity may contribute to the high levels of depressed mood among soldiers returning from combat, the study suggested.

Fish oil content is especially important for soldiers due to the consistent training and physical regiments performed in and out of combat and risk of traumatic brain injury.

For the study, published in the journal Military Medicine, researchers worked with 100 soldiers to identify which factors affected the moods of those returning from combat.

"We looked at how physical activity levels and performance measures were related to mood state and resiliency. What we found was the decrease in physical activity and the concentration of fish oil and Omega-3s in the blood were all associated with resiliency and mood," said Richard Kreider, Researcher at the Texas A and M University.

The study originated from research that examined Omega-3 fatty acid levels of soldiers who committed suicide compared to non-suicide control and found lower Omega-3 levels in the blood were associated with increased risk of being in the suicide group.

According to the researchers, these findings are significant toward addressing some of the issues many soldiers face.

"The mental health of soldiers is a serious concern and it is exciting to consider that appropriate diet and exercise might have a direct impact on improving resiliency," said Nicholas Barringer, Researcher at the Texas A and M University.

In order to properly measure soldiers physically, Kreider and Barringer developed a formula that has the potential to assist in effectively screening soldiers with potential post-traumatic stress disorder (PTSD) ahead of time. 

The formula measures a number of factors including fitness and psychometric assessments, physical activity and additional analysis.

"By improving resiliency in service members, we can potentially decrease the risk of mental health issues. Early identification can potentially decrease the risk of negative outcomes for our active service members as well as our separated and retired military veterans," Barringer added. 

"The military is using some of our exercise, nutrition, and performance-related work and the findings may help identify soldiers at risk for depression when they return from combat tours," Kreider added. 

The study mentioned that by working to identify such high-risk issues faced by soldiers, it can set a precedent that will benefit not only the military leadership, but also the general public.

​London, Sep 24 (IANS) To identify individuals at risk of coronary heart disease (CHD) much earlier and improve its prevention, a new genetic risk tool has been developed by an Indian-origin researcher.

Genetic factors have long been known to make a significant contribution to CHD risk. Recent advances in genetics have led to the identification of many Single Nucleotide Polymorphisms, or SNPs -- very small differences in our DNA that vary from person to person. 

The research, published in the European Heart Journal, shows how using this new knowledge could pave the way for earlier and more personalised preventative interventions.

By looking at over 49,000 SNPs the researchers created a score, known as a genomic risk score (GRS), and showed that the higher the GRS the higher the future risk of CHD. People with a GRS in the top 20 per cent had an over five-fold higher life-time risk of CHD.

The clinical risk scores are based on known risk factors for CHD such as cholesterol level, having high blood pressure or diabetes and smoking. But such scores are imprecise and unable to identify a large proportion of people who develop CHD. 

The researchers showed that the GRS was independent of the clinical risk scores and by combining the two risk score tools they were better able to predict people who were at risk of developing CHD in the next 10-years.

"This study shows the potential benefits of using a genetic risk score over and above current methods to identify people at increased risk of coronary heart disease. We already know that CHD starts at an early age, several decades before symptoms develop, and preventative measures should ideally be applied much earlier, especially to those who are at increased risk," said Nilesh Samani, Professor at the University of Leicester, England.

Beijing, Sep 25 (IANS) The world's largest radio telescope began operations on Sunday in a mountainous region of China's Guizhou province.

Shortly after noon, in a valley in Pingtang county, hundreds of astronomers and astronomy enthusiasts witnessed the official launch of the Five-hundred-metre Aperture Spherical Telescope's (FAST) mission to explore space and hunt for extraterrestrial life, Xinhua news agency reported.

Work on the nearly 1.2 billion-yuan ($180 million) project started in 2011, 17 years after it was proposed by Chinese astronomers.

The installation of the telescope's main structure -- a 4,450-panel reflector as large as 30 football pitches -- was finished in early July.

This study aimed to describe the status of Tourism Cultural and Promotional Development Division Office (TCPDD) of City Economic Management and Cooperative Development Office of CEMCDO. 

The study was conducted to determine the work ethics, values and performance of the Officers, specifically the

​Toronto, Sep 23 (IANS) Hormonal changes that women experience throughout their menstrual cycles can have significant effects on how they approach and solve problems, a study has found.

Women have sometimes reported that their memory works differently depending on which phase of the menstrual cycle they are in -- even during and following pregnancy, or following menopause, the study said. 

"Our research shows that, rather than impairing memory in general, oestrogen and progesterone - female sex hormones - may instead cause the brain to favour one memory system or strategy over another," said Wayne Brake, Professor at Concordia University in Quebec, Canada. 

For the study, researchers tested 45 women who had regular menstrual cycles. First, participants responded to a 'hormonal profile' questionnaire that gathered detailed information on their periods, past pregnancies, contraceptive and synthetic hormone intake history and general life habits.

The participants were then given a verbal memory task, such as remembering a list of words, as well as a virtual navigation task, such as finding their way through a maze in a video game, that could be solved in several ways.

The results showed that women who were ovulating performed better on the verbal memory task. On the other hand, women in their pre-menstrual phase tested better at solving spatial navigation tasks.

That proves that women tend to use different strategies to solve tasks -- such as navigating a maze or remembering a list of words -- depending on where they are in their menstrual cycle.

Previously studies have shown that the levels of oestrogen and progesterone in rodents influence different brain regions, affecting various memory systems involved in task-solving.

"For example, when oestrogen levels are high, female rats will use one type of memory system or strategy versus another to solve a maze. This is the first study to show that this is also true in humans (women), who solve tasks in different ways based on their hormones," Brake noted, in the paper published in the journal Psychoneuroendocrinology.

​New York, Sep 23 (IANS) In a ray of hope for people with alopecia areata -- an autoimmune disease that causes patchy, and sometimes total hair loss - researchers have found promise in a drug which is already approved for treating certain bone marrow disorders.

In a study, researchers from Columbia University Medical Center (CUMC) reported that seventy five percent of patients with moderate to severe alopecia areata had significant hair regrowth after treatment with ruxolitinib.

By the end of their treatment, average hair regrowth was 92 percent, said the study published in the Journal of Clinical Investigation/Insight.

Ruxolitinib is a US Food and Drug Administration (FDA)-approved drug that inhibits the Janus kinase (JAK) family of enzymes known as JAK inhibitors.

"Although our study was small, it provides crucial evidence that JAK inhibitors may constitute the first effective treatment for people with alopecia areata," said Julian Mackay-Wiggan, Associate Professor at CUMC .

"This is encouraging news for patients who are coping with the physical and emotional effects of this disfiguring autoimmune disease," Mackay-Wiggan noted.

Alopecia areata, the second most common form of hair loss, can occur at any age and affects men and women equally. 

The disease usually causes hair loss on the scalp, but some patients also experience facial and body hair loss, with devastating consequences particularly in children. Currently, there is no known treatment that can completely restore hair.

Previously, the Columbia researchers identified the specific immune cells and the dominant inflammatory signalling pathways responsible for attacking the hair follicle in alopecia areata, putting them into a dormant state. 

Subsequent experiments with mouse and human hair follicles showed that topical and oral drugs that inhibit the Janus kinase family of enzymes, reawaken these dormant follicles by blocking inflammatory signalling. 

Two such JAK inhibitors already approved by the U.S. FDA are ruxolitinib, a medication that is used to treat bone marrow malignancies, and tofacitinib, a treatment for rheumatoid arthritis.

To test this hypothesis, the researchers initiated a small, open-label clinical trial of 12 patients with moderate to severe alopecia areata (more than 30 per cent hair loss). 

All patients were given 20 mg of oral ruxolitinib, twice a day, for three to six months.

Participants were followed for an additional three months to assess the durability of treatment response.

Nine of the patients had hair regrowth of 50 per cent or more. By the end of the treatment period, 77 per cent of those who responded to the therapy achieved hair regrowth of over 95 per cent. 

A third of the responders had significant hair loss in the follow-up period after the medication was stopped, although their hair loss did not reach pre-treatment levels.

The drug was well tolerated in all participants with no serious adverse effects, the researchers reported.

New York, Sep 23 (IANS) A gene that can potentially reduce female mosquitoes has been identified by a team of US researchers. That's good news for malaria, dengue, Zika control. The bad news is this happens over generations of moquitoes.

Female mosquitoes draw human blood to facilitate their egg production and are also the prime carriers of the pathogens that cause deadly diseases like malaria, Zika, and dengue fever.

The study found that placing a particular Y chromosome gene on the autosomes of Anopheles stephensi mosquitoes -- a species responsible for transmitting malaria -- killed off 100 per cent of all female embryos that inherited this gene.

The extra copy of this gene, which the researchers call Guy1, is passed on to both sexes but only males survive, the study said. 

"The Guy1 protein is a strong candidate of the male determining factor in Anopheles stephensi," said Zhijian "Jake" Tu, Professor at the Virginia Polytechnic Institute and State University in the US.

"The extra copy of the Guy1 gene is only passed down to half of the progeny, leaving some females among the mosquitoes that did not inherit the gene in the next generation," added Frank Criscione from Virginia Polytechnic Institute and State University in the US.

In order to produce all male offspring, all progeny needs to inherit this extra copy of Guy1, which can potentially be achieved by using genome-editing, the researchers stated, in the paper published in the journal eLife.

London, Sep 23 (IANS) Researchers have found a potential new way of stopping one of the most aggressive types of brain tumour from spreading, which could also lead the way to better patient survival.

Glioblastoma, which is one of the most common types of malignant brain tumours in adults, grow fast as well as spread easily. 

The tumour has threadlike tendrils that extend into other parts of the brain making it difficult to remove it all, the study from the University of Southampton in Britain said.

The findings suggest that by blocking specific enzymes called ADAM10 and ADAM17, the tumour can be stopped from growing and spreading. 

It also moves the cancer cells away from the place where they were growing which could allow them to be removed through traditional cancer treatments such as radiotherapy, chemotherapy or surgery, the researchers noted.

"Glioblastoma is a devastating disease which is often untreatable. We have found that blocking ADAMs may lead to reduced tumour growth and less recurrence following conventional treatments, improving the chance of complete surgical removal and improving survival rates," said Sandrine Willaime-Morawek, Lecturer at the University of Southampton in Britain.

The current treatment regimens are ineffective against the small population of cancer stem cells residing in the tumourigenic niche. 

These tumours are highly proliferative and infiltrative resulting in a median patient survival of only 14 months from diagnosis.

However, the new therapeutic approach could involve the removal of these cells from the microenvironment that maintains the cancer stem cell phenotype, the researchers concluded in the paper published in the journal Molecular Neurobiology.