Invading black holes cause ‘cosmic flashes’

Washington, September 19 (ANI): Mathematicians at the University of Leeds, UK, have determined that cosmic flashes, known as gamma ray bursts, are produced by jets of plasma that originate from invading black holes.

Gamma ray bursts are beams of high-energy radiation that are similar to the radiation emitted by explosions of nuclear weapons.

The orthodox model for this cosmic jet engine involves plasma being heated by neutrinos in a disk of matter that forms around a black hole, which is created when a star collapses.

But, mathematicians at the University of Leeds, have come up with a different explanation: the jets come directly from black holes, which can dive into nearby massive stars and devour them.

Their theory is based on recent observations by the Swift satellite, which indicates that the central jet engine operates for up to 10,000 seconds – much longer than the neutrino model can explain.

Mathematicians believe that this is evidence for an electromagnetic origin of the jets, that is, that the jets come directly from a rotating black hole, and that it is the magnetic stresses caused by the rotation that focus and accelerate the jet’s flow.

For the mechanism to operate, the collapsing star has to be rotating extremely rapidly.

This increases the duration of the star’s collapse as the gravity is opposed by strong centrifugal forces.

One particularly peculiar way of creating the right conditions involves not a collapsing star, but a star invaded by its black hole companion in a binary system.

The black hole acts like a parasite, diving into the normal star, spinning it with gravitational forces on its way to the star’s centre, and finally eating it from the inside.

“The neutrino model cannot explain very long gamma ray bursts and the Swift observations, as the rate at which the black hole swallows the star becomes rather low quite quickly, rendering the neutrino mechanism inefficient, but the magnetic mechanism can,” said Professor Komissarov from the School of Mathematics at the University of Leeds.

“Our knowledge of the amount of the matter that collects around the black hole and the rotation speed of the star allow us to calculate how long these long flashes will be – and the results correlate very well with observations from satellites,” he added. (ANI)

Findings from India’s Chandrayaan to provide new understanding of lunar surface

London, September 18 (ANI): India’s Chandrayaan-1 X-ray Spectrometer (C1XS) has gathered data for a total of 30 solar flares, giving the most accurate measurements to date of magnesium, aluminum, silicon, calcium, and iron in the lunar surface.

Although contact was lost with Chandrayaan-1 last month, the enhanced performance of the C1XS instrument, which exceeded its design specification, means that the science team will be able to determine the geochemistry of new areas of the lunar surface, adding some vital pieces to the jigsaw of the mineralogy of the lunar surface.

The miniature C1XS instrument investigated the lunar surface using an effect whereby X-ray illumination from the Sun causes rocks to fluoresce, emitting light at a different wavelength.

This re-emitted light contains spectral peaks that are characteristic of elements contained in the rock, revealing its composition.

Solar flares act like a flash bulb, giving added illumination and allowing C1XS to ‘see’ more elements.

During normal conditions, C1XS could detect magnesium, aluminum, and silicon and collected data on the levels of these elements, enabling detailed mapping of areas of the lunar surface during its operational period.

During the 30 solar flares, C1XS detected calcium and iron (and sometimes titanium, sodium, and potassium) in key areas in the southern hemisphere and on the far side of the Moon.

The spectral resolution of 50 km was much better than previous missions.

According to Professor Grande, “The C1XS team will be analyzing the data collected during the Chandrayaan-1 mission over the next few months, and the results will help us further our knowledge of the Moon and planetary formation.”

In addition, the design of the instrument has been proved very successful in that it withstood passage through the Earth’s radiation belts and went on to produce these wonderful high-resolution spectra. We were able to separate clear peaks for each of the target elements, allowing us not only to identify where they are present but give an accurate estimate for how much is there,” he said.

“The technology developed for C1XS opens up some exciting opportunities for future missions,” he added. (ANI)

World’s most advanced CT scanner to see through solids

Washington, September 11 (ANI): Researchers at The University of Nottingham, UK, have created the most advanced 3D X-ray micro Computed Tomography (CT) scanner in the world, which will help scientists from a wide variety of departments across the University literally see through solid materials, including soil.

Known as the ‘Nanotom’, the machine will make previously difficult and laborious research much easier as it allows researchers to probe inside objects without having to break into them.

The Nanotom will produce high-resolution 3D and slice images of solids with a pixel resolution of up to half micron or 500 nanometres.

It will be based at the School of Biosciences as the centrepiece of research into efforts to understand the microscopic interactions between plant root growth and soil structure.

The first project to use it will examine the sensing ability of roots to grow in the best direction for the health of the plant through the soil.

It aims to provide evidence of how the root reacts and adapts to soil stresses like drought and compaction by adjusting the genetic information in the tips of the root as it grows.

The Nanotom will allow researchers to follow the progress of the root growth and soil structural development for the first time without disturbing the sample of the plant growing in the soil.

The eventual aim of research like this is to contribute to worldwide efforts for food security and sustainable food production by preserving and improving the vital but finite soil resources of the planet.

It will enable scientists to come up with a recipe for the best soil composition and level of compaction as well as informing plant breeding programmes.

Accurate soil structure measurement will be also be essential in changing farming practices to cut CO2 which is released into the atmosphere during traditional ploughing of agricultural soil.

According to Dr Sacha Mooney from the University’s Division of Agricultural and Environmental Sciences, “This new kit will completely revolutionize our work in trying to understand the key factors that control some of the many functions that soils perform.”

“Of course it’s not just soils we’ll be scanning, I think I am just as excited about the opportunity to look inside newly created environmental building materials, eco-friendly crops developed to improve yield and even chocolate bars for the food industry,” Mooney added. (ANI)

Men with high levels of bone lead 6 times more likely to die from heart disease

Washington, Sept 10 (ANI): Men with high levels of lead in bones are six times more likely to die from heart disease, according to a new study.

Researchers from the Harvard School of Public Health (HSPH) and the University of Michigan School of Public Health found that bone lead was associated with a higher risk of death from all causes, particularly from cardiovascular disease.

“The findings with bone lead are dramatic,” said Marc Weisskopf, assistant professor of environmental and occupational epidemiology at HSPH and lead author of the study.

“It is the first time we have had a biomarker of cumulative exposure to lead and the strong findings suggest that, even in an era when current exposures are low, past exposures to lead represent an important predictor of cardiovascular death, with important public health implications worldwide,” he added.

During the study, the researchers examined 868 participants in the Department of Veterans Affairs Normative Aging Study, a study of aging in men that began in 1963. Blood lead and bone lead were analyzed using X-ray fluorescence.

The results showed that the risk of death from cardiovascular disease was almost six times higher in men with the highest levels of bone lead compared to men with the lowest levels.

The risk of death from all causes was 2.5 times higher in men with the highest levels of lead compared to those with the lowest levels.

According to the authors, there are a number of mechanisms, such as increased oxidative stress, by which lead exposure may result in cardiovascular mortality.

They also note that, in addition to high blood pressure, exposure to lead has been associated with widened pulse-pressure (an indicator of arterial stiffening) and heart disease.

Given that bone lead may be a better biomarker of cumulative lead exposure than blood lead, it may be the best predictor of chronic disease from exposure to lead in the environment.

The study appears in journal Circulation. (ANI)

“Saddam-style” torture and death penalty still prevalent in Iraq: Amnesty

Baghdad (Iraq), Sep 1(ANI): Amnesty International on Tuesday said that even though Iraq has been free from Saddam Hussein’s regime for six years, more than 1,000 prisoners are still facing death penalty in the country.

It said that Iraq’s burdened justice system can barely cope with ordinary crimes, and punishment for crimes ranging from murder to the membership and support of armed groups are out of bounds for them.

“Many Iraqis who had been traumatised by his policies hoped and expected that a new chapter would be opened in which human rights would be respected and upheld, and that torture, killings and the death penalty would remain only as a bad memory of the past,” The Daily Express quoted Amnesty International, as saying.

“Six years on (from the fall of the regime in 2003), as an estimated 1,000 prisoners face the prospect of execution, that dream has all but faded to nothing,” it added.

Amnesty further said that instead of wiping away the death penalty, Iraqi government had widened both the scope and application of penalty in 2004, and called for an “immediate moratorium” on all executions.

It further added that Iraq use of the death penalty “lacks transparency”, and trails in the country fail to match international standards and said it expressed disappointment that Iraq’s Human Rights Minister Dr Wajdan Mikhail Salam advocates the death penalty.

It also said that people suffering from death penalties should be given a ray of hope to contend their cases again.

Amnesty also claimed that complaints were received from defendants in numerous cases that confessions were extracted from them under torture.

It further informed that out of the 1,000 prisoners, some 150 have exhausted all means of appeal or clemency and are at “immediate risk of death”. (ANI)

Newly found natural odours could pave way for developing mosquito repellents

London, Aug 27 (ANI): In a lab study on fruit flies, entomologists led by an Indian origin scientist at the University of California, Riverside, have discovered a novel class of compounds that could help in developing inexpensive and safe mosquito repellents for combating West Nile virus and other deadly tropical diseases.

Under stress, fruit flies emit carbon dioxide (CO2) that serves as a warning to other fruit flies that danger or predators could be nearby.

The fruit flies are able to detect the CO2 and escape because their antennae are equipped with specialized neurons that are sensitive to the gas.

But fruits and other important food sources for fruit flies also emit CO2 as a by-product of respiration and ripening.

Researchers started to wonder how does fruit flied find their way to these foods, despite having an inherent tendency to avoid CO2.

However, Anandasankar Ray, an assistant professor in the Department of Entomology, and Stephanie Turner, his graduate student, have now identified a new class of odorants – chemical compounds with smells – present in ripening fruit that prevent the CO2-sensitive neurons in the antennae from functioning.

They discovered that particularly two odours, hexanol and 2,3- butanedione, are strong inhibitors of the CO2-sensitive neurons in the fruit fly.

The research has strong implications for control of deadly diseases transmitted by Culex mosquitoes such as West Nile virus disease and filariasis, an infectious tropical disease affecting the lymphatic system.

“CO2 emitted in human breath is the main attractant for the Culex mosquito to find people, aiding the transmission of these deadly diseases. In our experiments we identified hexanol, and a related odor, butanal, as strong inhibitors of CO2-sensitive neurons in Culex mosquitoes. These compounds can now be used to guide research in developing novel repellents and masking agents that are economical and environmentally safe methods to block mosquitoes’ ability to detect CO2 in our breath, thereby dramatically reducing mosquito-human contact,” Nature quoted Ray as saying.

Inhibitory odours not only play an important role in modifying insect behaviour, but the study found that some of these odours even have a long-term effect.

For example, the researchers found that some odours silenced the CO2 neuron in the fruit fly well beyond the period of application.

“To our surprise, we found that exposure to a long-term CO2 response inhibitor can exert a profound and specific effect on the behavior of the insect, even after the inhibitor is no longer in the environment.

This means this odorant could potentially be used to keep mosquitoes at bay for longer periods of time, benefiting people in areas where mosquito-transmitted diseases are prevalent,” said Ray.

The results of the study appear in Nature. (ANI)

New X-ray technique reveals buried image in N. C. Wyeth’s painting

Washington, August 20 (ANI): A new X-ray imaging technique has for the first time in a century revealed unprecedented details of a painting hidden beneath another painting by famed American illustrator Newell Convers Wyeth, who is regarded as the greatest American illustrator of the 20th century.

While making a presentation at the 238th National Meeting of the American Chemical Society (ACS) on Wednesday, Dr. Jennifer Mass said that the non-destructive look-beneath-the-surface method could reveal hidden images in hundreds of Old Master paintings, and other prized works of art.

In the study paper, the researcher noted that many great artists re-used canvases or covered paintings with other paintings, in order to save money on materials or to let the colours and shapes of a prior composition influence the next one.

Art historians believe that several of Wyeth’s most valued illustrations have been lost from view in that way, and one of them, depicting a dramatic fist fight, was published in a 1919 Everybody’s Magazine article titled ‘The Mildest Mannered Man’.

X-ray techniques previously used by other scientists suggested that Wyeth had covered the fight scene with another painting called ‘Family Portrait’, but they had not shown the the true image except in black and white reproductions.

The new instrument, called a confocal X-ray fluorescence microscope, was developed at the Cornell High Energy Synchrotron Source (CHESS) national X-ray facility.

The instrument reveals minute details in hidden paintings without removing paint samples. It shoots X-ray beams into a painting and then collects fluorescent X-ray “signals” given off by the chemicals in the various paint layers.

Scientists can link each signal to specific paint pigments.

In addition to revealing the original image, the method is providing new information on Wyeth’s materials and methods.

The same technique may ultimately reveal hidden images in paintings by other famed artists, the researchers say. (ANI)

Now, Sikhs accuse BBC’s Asian network of religious bias

London, Aug.20 (ANI): The BBC’s Asian Network is at the center of a race row after Sikhs accused the digital radio station of being insensitive towards their religion.

The BBC were forced to remove a show from their website after Adil Ray, a popular Muslim presenter, received threats from Sikh listeners who accused him of denigrating one of their religious symbols, The Telegraph reports.

The row centres around a show broadcast earlier this month in which Ray discussed a Punjabi music concert in Canada where police had banned a number of Sikhs who refused to remove their “kirpan” dagger. number of listeners believed that Ray had been disparaging about whether Sikhs really needed to carry their kirpan – a ceremonial symbol that baptised Sikhs are expected to wear at all times – and began making complaints and threats against him.

The Birmingham-based network has strongly denied the accusations or any suggestion that Ray meant to mock Sikhism.

The row has nonetheless raised fresh questions over whether the digital network, which was set up eight years ago after the BBC’s then director general Greg Dyke described the corporation as “hideously white”, is serving its Asian listeners.

Last year, Labour peer Lord Ahmed accused the network of being biased against Muslims in favour of Sikhs and Hindus, although an internal investigation by the BBC later exonerated it.

The Sikh Media Monitoring Group has written to the BBC asking for a full transcript of Adil Ray’s show and accused the station of being insensitive towards Sikh listeners. (ANI)

Scientists use titanium dioxide nanoparticles to kill cancer cells, sparing healthy ones

Washington, August 20 (ANI): Scientists in America have developed a way to target brain cancer cells using inorganic titanium dioxide nanoparticles bonded to soft biological material.

This achievement is a result of the joint efforts of scientists from the U.S. Department of Energy’s (DOE) and the University of Chicago’s Brain Tumor Center.

Thousands of people die from malignant brain tumours every year, and the tumors are resistant to conventional therapies.

The researchers say that their nano-bio technology may eventually provide an alternative form of therapy, which targets only cancer cells and does not affect normal living tissue.

“It is a real example of how nano and biological interfacing can be used for biomedical application. We chose brain cancer because of its difficulty in treatment and its unique receptors,” said scientist Elena Rozhkova with the DOE’s Argonne National Laboratory.

The novel approach relies upon a two-pronged approach.

The researchers describe titanium dioxide as a versatile photoreactive nanomaterial that can be bonded with biomolecules.

When linked to an antibody, they say, nanoparticles recognize and bind specifically to cancer cells.

When focused visible light is shined onto the affected region, the researchers add, the localized titanium dioxide reacts to the light by creating free oxygen radicals that interact with the mitochondria in the cancer cells.

Mitochondria act as cellular energy plants, and when free radicals interfere with their biochemical pathways, mitochondria receive a signal to start cell death.

“The significance of this work lies in our ability to effectively target nanoparticles to specific cell surface receptors expressed on brain cancer cells,” said Dr. Maciej S. Lesniak, Director of Neurosurgical Oncology at University of Chicago Brain Tumor Center.

“In so doing, we have overcome a major limitation involving the application of nanoparticles in medicine, namely the potential of these agents to distribute throughout the body. We are now in a position to develop this exciting technology in preclinical models of brain tumours, with the hope of one day employing this new technology in patients,” Lesniak added.

Using X-ray fluorescence microscopy at Argonne’s Advanced Photon Source, the researchers have also found that the tumours’ invadopodia, actin-rich micron scale protrusions that allow the cancer to invade surrounding healthy cells, can be also attacked by the titanium dioxide.

The researchers have thus far carried out tests on cells in a laboratory setting, but animal testing is planned for the next phase.

Results show an almost 100 percent cancer cell toxicity rate after six hours of illumination, and 80 percent after 48 hours.

Also, since the antibody only targets the cancer cells, surrounding healthy cells are not affected, unlike other cancer treatments such as chemotherapy and radiotherapy.

Rozhkova said that a proof of concept is demonstrated, and other cancers can be treated as well using different targeting molecules.

The expert, however, admits that the research is presently in the early stages. (ANI)

Radiation from massive stars may trigger many more stars than previously thought

Washington, August 13 (ANI): A new study from two of NASA’s Great Observatories has shown that radiation from massive stars may trigger the formation of many more stars than previously thought.

While astronomers have long understood that stars and planets form from the collapse of a cloud of gas, the question of the main causes of this process has remained open.

One option is that the cloud cools, gravity gets the upper hand, and the cloud falls in on itself.

The other possibility is that a “trigger” from some external source – like radiation from a massive star or a shock from a supernova – initiates the collapse.

Some previous studies have noted a combination of triggering mechanisms in effect.

By combining observations of Cepheus B from the Chandra X-ray Observatory and Spitzer Space Telescope, researchers have taken an important step in addressing this question.

Cepheus B is a cloud of mainly cool molecular hydrogen located about 2,400 light years from the Earth.

There are hundreds of very young stars inside and around the cloud – ranging from a few millions years old outside the cloud to less than a million in the interior – making it an important testing ground for star formation.

“Astronomers have generally believed that it’s somewhat rare for stars and planets to be triggered into formation by radiation from massive stars,” said Konstantin Getman of Penn State University, and lead author of the study. “Our new result shows this belief is likely to be wrong,” he added.

This particular type of triggered star formation had previously been seen in small populations of a few dozen stars, but the latest result is the first time it has been clearly observed in a rich population of several hundred stars.

The new study suggests that star formation in Cepheus B is mainly triggered by radiation from one bright, massive star outside the molecular cloud.

According to theoretical models, radiation from this star would drive a compression wave into the cloud triggering star formation in the interior, while evaporating the cloud’s outer layers.

The Chandra-Spitzer analysis revealed slightly older stars outside the cloud while the youngest stars with the most protoplanetary disks congregate in the cloud interior – exactly what is predicted from the triggered star formation scenario.

“We essentially see a wave of star and planet formation that is rippling through this cloud,” said co-author Eric Feigelson, also of Penn State. “Outside the cloud, the stars probably have newly born planets while inside the cloud the planets are still gestating,” he added. (ANI)

Earliest animals on Earth lived in lakes

Washington, July 28 (ANI): In a new research, scientists have found evidence that the earliest animals on Earth lived in lakes.

Conventional wisdom has it that animal evolution began in the ocean, with animal life adapting much later in Earth history to terrestrial environments.

Now, a UC (University of California) Riverside-led team of researchers, studying ancient rock samples in South China, has found that the first animal fossils in the paleontological record are preserved in ancient lake deposits, not marine sediments as commonly assumed.

“We know that life in the oceans is very different from life in lakes, and, at least in the modern world, the oceans are far more stable and consistent environments compared to lakes which tend to be short-lived features relative to, say, rates of evolution,” said Martin Kennedy, a professor of geology in the Department of Earth Sciences who participated in the research.

“Thus it is surprising that the first evidence of animals we find is associated with lakes, a far more variable environment than the ocean,” he added.

The study raises questions such as what aspects of the Earth’s environment changed to enable animal evolution.

In their research, the authors focused on South China’s Doushantuo Formation, one of the oldest fossil beds that houses highly preserved fossils dated to about 600 million years ago.

These beds have no adult fossils. Instead, many of the fossils appear as bundles of cells interpreted to be animal embryos.

“Our first unusual finding in this region was the abundance of a clay mineral called smectite,” said lead author Tom Bristow, who worked in Kennedy’s lab.

“In rocks of this age, smectite is normally transformed into other types of clay. The smectite in these South China rocks, however, underwent no such transformation and have a special chemistry that, for the smectite to form, requires specific conditions in the water – conditions commonly found in salty, alkaline lakes,” he added.

The researchers’ work involved collecting hundreds of rock samples from several localities in South China, carrying out mineralogical analysis using X-ray diffraction, and collecting and analyzing other types of geochemical data.

“All our analyses show that the rocks’ minerals and geochemistry are not compatible with deposition in seawater,” Bristow said.

“Moreover, we found smectite in only some locations in South China, and not uniformly as one would expect for marine deposits. This was an important indicator that the rocks hosting the fossils were not marine in origin. Taken together, several lines of evidence indicated to us that these early animals lived in a lake environment,” he added. (ANI)

121 breeding tigers in Nepal spells new ray of hope for the species

Washington, July 28 (ANI): Conservationists worrying about the fate of the majestic tiger can now breathe a sign of relief as about 121 breeding tigers are estimated to have been found in Nepal.

The figures announced by the Nepal Government’s Department of National Parks and Wildlife Conservation (DNPWC) shows the presence of 121 (100 – 194) breeding tigers in the wild within the four protected areas of Nepal.

The 2008 tiger population estimate was jointly implemented by the DNPWC, Department of Forests (DOF), WWF, National Trust for Nature Conservation (NTNC) with support from Save The Tiger Fund (STF), WWF-US, WWF-UK, WWF International and US Fish and Wildlife Service (USFWS).

“To obtain reliable population estimates of wide ranging species like the tiger, it is important to undertake the survey simultaneously in all potential habitats,” said Dr. Rinjan Shrestha, Conservation Biologist with WWF Nepal.

Previous studies had been undertaken in different time periods and at different spatial scales.

“To derive information on both abundance and distribution of tigers, the current survey employed two methods – Camera Trapping method inside the protected areas and Habitat Occupancy survey both inside and outside the protected areas,” said Dr. Shrestha.

“The tiger numbers have increased in Chitwan but decreased in Bardia and Shuklaphanta,” said Anil Manandhar, Country Representative, WWF Nepal.

“In spite of the decade long insurgency, encroachment, poaching and illegal trade, the present numbers is a positive sign, but we can’t remain unworried.

The declining numbers in western Nepal has posed more challenges, needing a concerted effort to save this charismatic endangered species focusing on anti-poaching and illegal wildlife trade,” he added.

The Government of Nepal has approved and launched the ‘Tiger conservation Action Plan 2008- 2012′.

A comprehensive management plan has been devised in which the target is to increase the population of tigers by 10 per cent within the first 5 year period of the plan implementation.

“Tigers can not be saved by the effort of a single individual or a single organization,” said Gopal Prasad Upadhyay, Director General, DNPWC.

“The transboundary relation with India needs to be strengthened further and all organizations should work together to conserve tigers,” he added. (ANI)

Tennis ace Andy Murray in pet scare

London, July 16 (ANI): Scottish professional tennis player Andy Murray was in a tizzy when his pet dog had to be rushed to the vet, after it ate many rocks from the garden.

Murray, 22, became worried when his border terrier pet dog Maggie started suffering from a mystery illness.

He had a pet ambulance collect Maggie from his 5million-pound home in Oxshott, Surrey, and an X-ray revealed the rocks.

Vets removed them, and Maggie was back to her playful self in a couple of days.

“Stones are usually left to pass through a dog’s body but these were too big,” the Sun quoted a source as saying. (ANI)

Astronomers see high-speed galaxy collision in action

Washington, July 10 (ANI): Astronomers at the Chandra X-ray Observatory have spotted a galaxy collision in action, with one galaxy passing through the core of other galaxies at almost 2 million miles per hour.

The image obtained is of Stephan’s Quintet, a compact group of galaxies discovered about 130 years ago and located about 280 million light years from Earth.

Four of the galaxies in the group are visible in the optical image from the Canada-France-Hawaii Telescope.

A labeled version identifies these galaxies (NGC 7317, NGC 7318a, NGC 7318b and NGC 7319) as well as a prominent foreground galaxy (NGC 7320) that is not a member of the group.

The galaxy NGC 7318b is passing through the core of galaxies at almost 2 million miles per hour, and is thought to be causing the ridge of X-ray emission by generating a shock wave that heats the gas.

Additional heating by supernova explosions and stellar winds has also probably taken place in Stephan’s Quintet.

A larger halo of X-ray emission, detected by ESA’s (European Space Agency’s) XMM-Newton could be evidence of shock heating by previous collisions between galaxies in this group.

Some of the X-ray emissions are likely caused by binary systems containing massive stars that are losing material to neutron stars or black holes.

Stephan’s Quintet provides a rare opportunity to observe a galaxy group in the process of evolving from an X-ray faint system dominated by spiral galaxies to a more developed system dominated by elliptical galaxies and bright X-ray emission.

According to scientists, being able to witness the dramatic effect of collisions in causing this evolution is important for increasing the understanding of the origins of the hot, X-ray bright halos of gas in groups of galaxies.

Stephan’s Quintet shows an additional sign of complex interactions in the past, notably the long tails visible in the optical image.

These features were probably caused by one or more passages through the galaxy group by NGC 7317. (ANI)

Milky Way’s “dark matter” mystery solved by astrophysicists

Washington, July 9 (ANI): A team of astrophysicists has solved a mystery that led some scientists to speculate that the distribution of certain gamma rays in our Milky Way galaxy was evidence of a form of undetectable “dark matter” believed to make up much of the mass of the universe.

In two separate scientific papers, the astrophysicists show that this distribution of gamma rays can be explained by the way “antimatter positrons” from the radioactive decay of elements, created by massive star explosions in the galaxy, propagate through the galaxy.

Thus, the scientists said, the observed distribution of gamma rays is not evidence for dark matter.

“There is no great mystery,” said Richard Lingenfelter, a research scientist at UC San Diego’s Center for Astrophysics and Space Sciences who conducted the studies with Richard Rothschild, a research scientist also at UCSD, and James Higdon, a physics professor at the Claremont Colleges.

“The observed distribution of gamma rays is in fact quite consistent with the standard picture,” he added.

Over the past five years, gamma ray measurements from the European satellite INTEGRAL have perplexed astronomers, leading some to argue that a “great mystery” existed because the distribution of these gamma rays across different parts of the Milky Way galaxy was not as expected.

To explain the source of this mystery, some astronomers had hypothesized the existence of various forms of dark matter, which astronomers suspect exists, but have not yet found.

What is known for certain is that our galaxy and others are filled with tiny subatomic particles known as positrons, the antimatter counterpart of typical, everyday electrons.

The scientists calculated that most of the gamma rays should be concentrated in the inner regions of the galaxy, just as was observed by the satellite data.

“The observed distribution of gamma rays is consistent with the standard picture where the source of positrons is the radioactive decay of isotopes of nickel, titanium and aluminum produced in supernova explosions of stars more massive than the Sun,” said Rothschild.

The scientists point out that a basic assumption of one of the more exotic explanations for the purported mystery – dark matter decays or annihilations – is flawed, because it assumes that the positrons annihilate very close to the exploding stars from which they originated.

“We clearly demonstrated this was not the case, and that the distribution of the gamma rays observed by the gamma ray satellite was not a detection or indication of a ‘dark matter signal’,” said Lingenfelter. (ANI)

Nuclear science unravels mysteries of ancient mummies

Washington, July 8 (ANI): A study has said that advanced nuclear science can shed new light into the well-being and nutrition of ancient mummies.

Paleoradiology uses nuclear technologies such as X-rays, computed tomography (CT), and Magnetic Resonance Imaging (MRI) to study artefacts, skeletons, mummies and fossils.

Many museums worldwide use the nuclear technologies to discover otherwise hidden details that piece together historic puzzles.

X-ray technology has been around since 1896, and CT since 1979. Advances since then make the technologies increasingly exact, and quick.

Newer prototypes of computed tomography can give additional insights, including both about the well-being and nutrition of ancient mummies.

The technology has grown so rapidly that there now is a data overload, experts report.

In September 2008, an advanced CT technology called iCT (“i” for intelligent) was used in a Chicago, US, hospital to study a wealthy Egyptian priestess named Meresamum.

She was the first mummy scanned with iCT.

Through 3D images, paleoradiologists virtually are able to unravel the mummy. The approach is non-intrusive, leaving the mummy intact, untouched, and unharmed.

The measurements of Meresamum were so precise the scan was able to extract 30 billion measurements.

The raw data collected was 1000 times greater than that available in the 1990s. The resulting profile of the priestess provided details about her looks, health, eating habits and lifestyle.

The full data will take more than a year to analyze. (ANI)

Sustainable development needs to be inclusive: Selja

New Delhi, July 7 (ANI): Union Housing and Urban Poverty Alleviation Minister Kumari Selja said on Tuesday that sustainable development needs to be inclusive and different from mere economic development of the past, and its benefits must last well into the next generation, and beyond.

Delivering the inaugural address at the launch of Habitat Business Forum in New Delhi, the minister emphasised the role of private sector in contributing towards this cause has to be recognized and promoted on a large scale.

She also discussed the importance of Non-Government Organizations, saying that they can be very effective agent for building public awareness at the local level, for mobilizing community action, and for voicing local concerns.

Selja also highlighted that capital intensity of urban growth creates divide between the rich and the poor raising prices of basic amenities and making these inaccessible to poor.

The minister said it was critical that cities devise institutional framework for themselves that satisfy the requirements of good urban governance.

She said it is essential that urban local government translate national policies and programmes into local action.

Referring to the Rajiv Awas Yojana, Selja said the scheme is an effort to promote a slum free India in five years, adding that the government would extend support to states that are willing to assign property rights to people living in slum areas.

Rajiv Awas Yojna will offer a ray of hope to slum dwellers and other urban poor to access a decent and dignified living environment and an affordable home. (ANI)

Radioactive isotope in ice core record reflects solar activity over 600 years

Washington, July 4 (ANI): Scientists have analyzed Beryllium-10, a radioactive isotope, found from the NGRIP ice core, Greenland, which reflects solar activity over the past 600 years.

Beryllium-10, a radioactive isotope, is produced in cosmic ray showers.

Because stronger solar activity deflects cosmic rays away from Earth, low levels of beryllium-10 correlate with higher solar activity. However, few extensive beryllium-10 records exist.

Now, A.M. Berggren from the Department of Earth Sciences, Uppsala University, Uppsala, Sweden, and his colleagues have described a new 600-year beryllium-10 record from the North Greenland Ice Core Project (NGRIP), one of only two beryllium-10 records with annual resolution over several centuries.

Comparing the NGRIP record with the Dye-3 record from another site in Greenland, the researchers found that both show similar long-term trends with some short-term differences between the two sites.

The researchers also compared the NGRIP and Dye-3 data with sunspot records and with neutron data, which tracks cosmic ray intensity.

Their results confirm that ice core beryllium-10 reflects solar cycle variations as well as longer-term trends in solar activity.

They note that while recent beryllium-10 values are low, they do not indicate unusually high solar activity compared with the last 600 years. (ANI)

Marie Curie named greatest woman scientist of all time

London, July 2 (ANI): Nobel Prize-winning nuclear physicist Marie Curie, who discovered that radiation therapy could treat cancer, has been voted the greatest woman scientist of all time.

The Polish-born researcher bagged over a quarter of the votes (25.1 per cent), almost double the votes received by her nearest rival Rosalind Franklin (14.2 per cent), the English biophysicist who helped discover the structure of DNA.

Third on the list was Hypatia of Alexandria, played by Rachel Weisz in a recent film about the fourth century Egyptian philosopher.

New Scientist magazine conducted the poll of 800 scientists and members of the public, which was commissioned by cosmetics company L’Oreal.

At the fourth position was astrophysicist Dame Jocelyn Bell Burnell with 4.7 per cent votes.

London-born Ada, the Countess of Lovelace, the mathematician who wrote the first computer programmes grabbed the fifth spot in the poll.

Austrian physicist Lise Meitner who discovered nuclear fission was sixth in the list, while British chemist Dorothy Hodgkin who pioneered X-ray techniques was at seventh.

Then came French-born Sophie Germain, who was one of the world’s greatest mathematicians, followed by American marine biologist Rachel Carson, who pioneered the global environmental movement ninth.

Standing proudly at the tenth spot is modern role model Dr Jane Goodall, the world famous primatologist, with 2.7 percent votes.

“The poll indicates the vital need to celebrate and raise awareness of the many female scientists who have shaped modern science since Marie Curie – and who are making a bigger contribution than ever,” the Telegraph quoted Dr Roger Highfield, the editor of New Scientist magazine, as saying.

Grita Loebsack, of L’Oreal said: “Women are at the forefront of advances in many scientific disciplines, particularly in health and life sciences.”

“The aim of the poll was to celebrate the contribution women have made to scientific research but also to highlight the lack of modern role models to encourage young women to pursue careers in science,” she added.

The Top 10 woman scientists of all time are:

1. Marie Curie (25.1 percent)

2. Rosalind Franklin (14.2 percent)

3. Hypatia of Alexandria (9.4 percent)

4. Dame Jocelyn Bell Burnell (4.7 percent)

5. Ada, Countess of Lovelace (4.5 percent)

6. Lise Meitner (4.4 per cent)

7. Dorothy Hodgkin (3.8 percent)

8. Sophie Germain (3.7 percent)

9. Rachel Carson (3.3 percent)

10. Dr Jane Goodall (2.7 percent) (ANI)

Astronomers discover new class of black holes

London, July 2 (ANI): An international team of astronomers has discovered a new class of black hole, more than 500 times the mass of the Sun.

Astronomers made the finding in a distant galaxy approximately 290 million light years from Earth.

Until now, identified black holes have been either super-massive in the centre of galaxies, or about the size of a typical star (between three and 20 Solar masses).

The new discovery is the first solid evidence of a new class of medium-sized black holes.

A black hole is a remnant of a collapsed star with such a powerful gravitational field that it absorbs all the light that passes near it and reflects nothing.

It had been long believed by astrophysicists that there might be a third, intermediate class of black holes, with masses between a hundred and several hundred thousand times that of the Sun.

However, such black holes had not been reliably detected until now.

The team, led by astrophysicists at the Centre d’Etude Spatiale des Rayonnements in France, detected the new black hole with the European Space Agency’s XMM-Newton X-ray space telescope.

“While it is widely accepted that stellar mass black holes are created during the death throes of massive stars, it is still unknown how super-massive black holes are formed,” said the lead author of the research paper, Dr. Sean Farrell, now based at the Department of Physics and Astronomy at the University of Leicester, UK.

“One theory is that super-massive black holes may be formed by the merger of a number of intermediate mass black holes. To ratify such a theory, however, you must first prove the existence of intermediate black holes,” he added.

“This is the best detection to date of such long sought after intermediate mass black holes. Such a detection is essential. While it is already known that stellar mass black holes are the remnants of massive stars, the formation mechanisms of supermassive black holes are still unknown,” said Farrell.

“The identification of HLX-1 is therefore an important step towards a better understanding of the formation of the super-massive black holes that exist at the centre of the Milky Way and other galaxies,” he added.

HLX-1 (Hyper-Luminous X-ray source 1), lies towards the edge of the galaxy ESO 243-49.

It is ultra-luminous in X-rays, with a maximum X-ray brightness of approximately 260 million times that of the Sun. (ANI)