Astronomers suggest more accurate star formation rates

Astronomers have found a new way of predicting the rate at which a molecular cloud—a stellar nursery—will form new stars. Using a novel technique to reconstruct a cloud’s 3-D structure, astronomers can estimate how many new stars it is likely to form. The newfound “recipe” allows for direct tests of current theories of star formation. It will also enable telescopes such as the Atacama Large Millimeter/submillimeter Array (ALMA) to estimate the star formation activity in more distant molecular clouds, and thus create a map of star births within our home galaxy.

Star formation is one of the fundamental processes in the universe—how  form, and under what conditions, shapes the structure of entire galaxies. Stars form within giant clouds of interstellar gas and dust. As a sufficiently dense region within such a molecular cloud collapses under its own gravity, it contracts until the pressure and the temperature inside are high enough for nuclear fusion to set in, signaling the birth of a star. 

Measuring  rates is extremely challenging, even throughout our home galaxy, the Milky Way. Only for nearby clouds, up to distances of about 1,500 light-years, are such measurements fairly straightforward—you simply count the young stars within that cloud. For more distant clouds, where it is impossible to discern individual stars, this technique fails, and star formation rates have remained uncertain. 

Now three astronomers, Jouni Kainulainen and Thomas Henning from the Max Planck Institute for Astronomy in Germany and Christoph Federrath from Monash University in Australia, have found an alternative way of determining star formation rates—a “recipe for star formation”—that links direct astronomical observations of the structure of a giant gas cloud to its star formation activity. 

The astronomers arrived at their result by modeling the 3-D structure of individual clouds in a simplified way. The data they use comes from an astronomical version of a medical X-raying procedure—as the light of distant stars shines through a cloud, it is dimmed by the cloud’s dust. The dimming of tens of thousands of different stars forms the basis of the 3-D reconstruction, which in turn shows the matter density for various regions within the cloud. 

For nearby clouds, Kainulainen and his colleagues compared their reconstruction and direct observations of how many  had recently formed in these clouds. In this way, they were able to identify a “critical density” of 5,000 hydrogen molecules per cubic centimeter and showed that only regions exceeding this critical density can collapse to form stars. 

“This is the first time anyone has determined a critical density for forming stars from observations of cloud structure,” said Kainulainen. “Theories of star formation have long predicted the importance of such a critical density. But our reconstruction technique is the first to allow astronomers to deduce the density structure of these clouds and to confront star formation theories with observational data.” 

“With these results and the tools we developed to test theories of star formation, we can even hope to tackle one of the greatest unanswered questions of astrophysics: If stars form within a cloud of a given mass, how many stars with what kind of mass can you expect?” asked Federrath. 

“There are many observations of molecular clouds, and with the advent of ALMA, much more precise data for more distant clouds will become available,” said Henning. “With our technique, we’re able to say: Show us your data, and we will tell you how many stars your cloud is forming right now.” 

ALMA is an array of 66 high-precision microwave antennas spread over distances of up to 10 miles (16 kilometers) in the Chilean desert and able to act as a single high-resolution telescope. ALMA has just commenced operations and can detect clouds of gas and dust with unprecedented sensitivity and in more detail than ever before. 

“We’ve handed astronomers a potent new tool. Star formation is one of the most fundamental processes in astronomy, and our results allow astronomers to determine star formation rates for more than ever before, both within our own galaxy and in distant other galaxies,” said Kainulainen.

Scientists discover how to make ethanol using just water and CO2 .

Scientists at Stanford University in the state of California say they’ve developed a procedure for making potent liquid ethanol that doesn’t rely on corn or any other crops traditionally involved in the process.

The researchers disclosed their discovery in the latest online edition of the journal Nature, and in it they say that in less than three years’ time they expect to have a prototype device ready that will make biofuel from using not much more than carbon monoxide, easily derived from carbon dioxide.

AFP Photo / Joe Raedle

We have discovered the first metal catalyst that can produce appreciable amounts of ethanol from carbon monoxide at room temperature and pressure – a notoriously difficult electrochemical reaction,” wrote Stanford’s Matthew Kanan, a co-author of the report released this week.

The scientists say that they are still a ways from developing said prototype, but believe they are on the right track towards achieving a goal that has the potential of providing people with a new, less-costly biofuel that could essentially revamp the energy industry.

I emphasize that these are just laboratory experiments today. We haven’t built a device,” Kanan said. “But it demonstrates the feasibility of using electricity that you could get from a renewable energy source to power fuel synthesis — in this case ethanol. There are some real advantages to doing that relative to using biomass to produce ethanol.”

Indeed, for one the new process unveiled out of the Ivy League school this week would eliminate crops from the equation needed to make biofuel, a change that is certain to revamp America’s agriculture landscape if the resources once required were no longer needed. According to the scientists, this alone could help push food prices down by no longer diverting thousands of acres worth of key crops to the energy sector. The traditional biofuel conversion process requires a single bushel of corn, for example, in order to make just three gallons of ethanol — along with hundreds upon hundreds of gallons of water, the Stanford News site reported this week.

Instead, the researchers say that biofuel would be generated by using a state-of-the-art device still in development that uses two electrodes, including one made of an “oxide-derived copper,” to convert it into fuel.

Copper,” the researchers wrote in their abstract, “…is the only known material with an appreciable [carbon monoxide electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use.”

But using a two-stop conversion process, the Stanford scientists say it’s entirely feasible to create a device that would create potent liquid fuel without requiring acres upon acres of farmland.

“The electrochemical conversion of CO2and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2capture,” they wrote.

Most materials are incapable of reducing carbon monoxide and exclusively react with water,” Kanan told the Stanford News site. “Copper is the only exception, but conventional copper is very inefficient.”

Prior to our study, there was a sense that no catalyst could efficiently reduce carbon monoxide to a liquid. We have a solution to this problem that’s made of copper, which is cheap and abundant,” he added. “We hope our results inspire other people to work on our system or develop a new catalyst that converts carbon monoxide to fuel.”

According to the Renewable Fuels Association, the US leads the world in ethanol production by generation around 13.3 billion gallons of the biofuel during the last calendar year.

Parasitic Amoeba Eats People Alive, Bite By Bite.

Scientists tackle human waste in space.

Scientists are developing a new technique which can turn astronaut urine into fuel and drinking water to tackle the problem of human waste in space.

Human waste on long term journeys into space makes up about half of the mission’s total waste, researchers said. Recycling it is critical to keeping a clean environment for astronauts.

And when onboard water supplies run low, treated urine can become a source of essential drinking water, which would otherwise have to be delivered from Earth at a tremendous cost, they said.

Previous research has shown that a wastewater treatment process called forward osmosis in combination with a fuel cell can generate power.

Eduardo Nicolau, from Department of Chemistry and NASA Center for Advanced Nanoscale Materials, University of Puerto Rico, and his team decided to build on these initial findings to meet the challenges of dealing with urine in space.

They collected urine and shower wastewater and processed it using forward osmosis, a way to filter contaminants from urea, a major component of urine, and water.

Their new Urea Bioreactor Electrochemical system (UBE) efficiently converted the urea into ammonia in its bioreactor, and then turned the ammonia into energy with its fuel cell.

The system was designed with space missions in mind, but “the results showed that the UBE system could be used in any wastewater treatment systems containing urea and/or ammonia,” the researchers concluded.


Lab-grown vaginas prove long-term success for four women born without one

Lab-grown vaginas prove long-term success for four women born without one.

From the desk of Zedie.

Scientists discover how parasite wreaks havoc by nibbling at intestines.

Microscope reveals how amoeba that kills 70,000 people a year works, giving clues to how other infections could operate

The gruesome means by which a parasite wreaks havoc in the human body has been laid bare for the first time by researchers who filmed the bug in action at the end of a microscope.

Infections of Entamoeba histolytica can trigger intestinal ulcers, gut inflammation and life-threatening diarrhoea in children in developing countries, but how the organism caused such distress was unknown.

One theory was that the parasite released toxins which destroyed cells in the intestine where it hunkers down in people who carry the infection. But the high-magnification video footage drew a thick line through that idea.

“To our surprise, with live microscopy, we found that the parasites were actually taking bites out of the human cells and that this eventually led to their death,” said Katherine Ralston at the University of Virginia.

“This is the first demonstration that nibbling can be used to kill,” she told the Guardian.

The same modus operandi might be employed by the brain-eating amoeba, Naegleria fowleri, Ralston said.

Amoeba attacks on human cells began almost as soon as Ralston introduced them to one another in a dish. The human cells took some chomping to kill them off, surviving for around 10 minutes before their membranes were torn apart and their inner contents spewed out.

“It’s the accumulation of physical damage. They can survive a limited number of bites but as the amoeba takes more and more bites, eventually the cell loses its membrane integrity and dies,” Ralston said. Details of the study are reported in Nature.

Amoeba do not have mouths to speak of, but the parasites appeared to use their cytoskeleton – the scaffolding that maintains their shape – to generate enough force to take chunks out of nearby cells.

“We think it’s really critical for the parasite to tear a bite off another living cell. The human cell material is stretched and then sheared off into individual bites,” she said. The process is called trogocytosis, after the Greek word, trogo, meaning nibble.

The amoeba did not finish the human cells off once they had killed them, but left their ripped-up remains where they fell and moved on to the next cell. Other amoeba who encountered killed human cells probed them for a bit, but moved on instead taking a bite themselves.

William Petri, a senior author on the paper, said the Virginia group was working on a vaccine to protect children against the infection. One target that has come from Ralston’s work is a molecule on the surface of the parasite that when blocked, prevents the amoeba from being able to nibble.

Records from children born in an urban slum in Dhaka, Bangladesh, show that one in three is infected with the parasite by the time they reach 12 months. The organism, which spreads through contaminated food and water, kills around 70,000 people each year, according to the World Health Organisation.

Some questions that remain are why the parasites stop eating once they have killed a human cell, and how they and others in the colony know when the job is done. Ralston says the parasites might be picking up on substances that are only exposed when a cell is pulled wide open.

Petri speculates that there might be a good reason for the parasites leaving scraps of dead cells behind. In an infected person, the remains would likely be cleared from the body by cells called macrophages, which release anti-inflammatory chemicals.

That suppression of the immune system might help the parasites to survive in humans for long periods. People who catch the infection can be healthy for six months but then develop a liver abscess caused by the parasite, Petri said.

Scientists name world’s 100 most unique and endangered birds.

‘Little dodo’, flightless parrot and giant ibis among species ranked by evolutionary distinctiveness and global extinction risk

100 most endangerd birds : Kakapo

At number four on the list is the kakapo (Strigops habroptila), a nocturnal, flightless parrot. Photograph: Tui De Roy/Corbis

The “little dodo”, a flightless parrot and the world’s largest ibis are among the world’s 100 most unusual and endangered birds, according to a new study.

Scientists from the Zoological Society of London (ZSL) and Yale University assessed the world’s 9,993 bird species according to their evolutionary distinctiveness and global extinction risk to produce a list of the world’s 100 most Evolutionarily Distinct and Globally Endangered (Edge) species.

Topping the list is the rare and striking giant ibis (Thaumatibis gigantea) – the world’s largest ibis weighing in at 4.2kg and reaching more than one metre in height. With only 230 pairs estimated to remain in the wild, it is a critically endangered species. Habitat loss, human disturbance and hunting have reduced its range to an extremely small, declining population concentrated in Cambodia.

At number four on the list is the kakapo (Strigops habroptila), a nocturnal parrot that has evolved to be flightless due to the historic absence of mammalian predators in its New Zealand habitat. Hunting, the introduction of predators, forest clearance and habitat degradation have caused a catastrophic decline in numbers. It is now extinct in its natural range, and survives only on three small, intensively managed islands after being relocated. Dedicated conservation efforts have increased the population to 125 individuals.

100 most endangerd birds : Giant Ibis (Thaumatibis gigantea)The giant ibis, Thaumatibis gigantea, which lives in Cambodia, tops the list. Photograph: FLPA/Alamy

At number 34 on the list is the tooth-billed pigeon (Didunculus strigirostris), also known as the “little dodo” and found only on the island of Samoa. With less than 250 adults estimated to survive in the wold, conservationists say urgent action is needed to prevent the species from meeting the same fate as its closest relative, the dodo. Loss of its forest habitat to agriculture and cyclones, hunting and invasive species are the greatest threats to this bird.

Half of the 100 highest ranked Edge bird species are receiving little or no conservation attention, the study warned. Carly Waterman, Edge programme manager at ZSL, said: “We lament the extinction of the dodo, but without action we stand to lose one of its closest relatives, the tooth-billed pigeon or ‘little dodo’, and many other extraordinary birds.

“The release of the Edge birds list enables us to prioritise our conservation efforts in the face of a mounting list of endangered species. These one-of-a-kind birds illustrate the incredible diversity that exists in our natural world.”

100 most endangered birds : Egyptian Vulture The Egyptian vulture (Neophron percnopterus) is one of only three European species on the list. Photograph: Alamy

Only three of the 100 Edge species are found in Europe. The Egyptian vulture (Neophron percnopterus), ranked at number 30, is found from the Ukraine, south throughout the Balkans to Greece and Turkey, but is threatened by poisoning, poaching, electrocution and human disturbance. At number 49, the sociable lapwing (Vanellus gregarius) has been found in Armenia, Turkey and Ukraine – and once in Essex – while the slender-billed curlew (Numenius tenuirostris) breeds in Russia and spends the winter in several eastern European countries.

At number 11, the spoonbilled sandpiper (Eurynorhynchus pygmeus) has become a temporary resident of the UK, with a captive breeding population of 25 birds at the WWT Slimbridge reserve in Gloucestershire. Eggs from the birds will eventually be taken back to the Arctic in a bid to rebuild the rapidly declining wild population.

The top 100 Edge birds are found in more than 170 countries. The list includes species from 22 of the 29 living orders of birds, with 18% made up of Passeriformes, more commonly known as perching birds. Twelve of the top 100 species belong to the family Charadriiformes (sandpipers), 11 from the family Accipitridae, which includes eagles, hawks and kites, and eight from the family Columbiformes (doves and pigeons).

100 most endangered birds : Spoon-billed Sandpiper At number 11, the spoonbilled sandpiper (Eurynorhynchus pygmeus), was a one-time resident of the UK after 13 young birds were flown over for captive breeding. iPhotograph: Chris Schenk/Corbis

Sixty-four per cent of the top 100 species are country endemic, meaning they are found nowhere else in the world. India has the highest number of Edge birds with 14 species, while the Philippines has the highest number of endemic Edge birds at nine species.

The study, “Distribution and conservation of global evolutionary distinctness in birds”, published on Thursday in the journal Current Biology, found that species representing the most evolutionary history over the smallest area as well as some of the most threatened distinct species are often found far from places that are species-rich or already on the conservation radar.

Lead author Prof Walter Jetz from Yale University and Imperial College London, said: “By identifying these top 100 species, we can now focus our efforts on targeted conservation action and better monitoring to help ensure that they are still here for future generations to come. As we show, conservation priorities can be adjusted to better conserve the avian tree of life and the many important functions it provides.”

The study was a collaboration between Yale University, Imperial College London, Sheffield University, University College London, Simon Fraser University and the University of Tasmania.

The world’s 100 most unusual and endangered birds

Giant Ibis
New Caledonian Owlet-nightjar
California Condor
Bengal Florican
Forest Owlet
Philippine Eagle
Christmas Island Frigatebird
Sumatran Ground-cuckoo
Spoon-billed Sandpiper
Northern Bald Ibis
New Zealand Storm-petrel
Hooded Grebe
White-shouldered Ibis
Black-hooded Coucal
Madagascar Serpent-eagle
Dwarf Olive Ibis
Rufous Scrub-bird
Noisy Scrub-bird
Junin Grebe
White-collared Kite
Congo Bay-owl
White-eyed River-martin
Red-headed Vulture
Peruvian Diving-petrel
Egyptian Vulture
St Helena Plover
Australian Painted Snipe
Cuban Kite
Tooth-billed Pigeon
Nahan’s Francolin
Sulu Hornbill
Purple-winged Ground-dove
Asian Crested Ibis
Sangihe Shrike-thrush
Jerdon’s Courser
Lesser Florican
Rufous-headed Hornbill
Masked Finfoot
Bahia Tapaculo
Waved Albatross
Stresemann’s Bristlefront
Sociable Lapwing
Eskimo Curlew
Slender-billed Curlew
Bannerman’s Turaco
Ashy Storm-petrel
Siberian Crane
White-throated Storm-petrel
Juan Fernandez Firecrown
Dark-winged Trumpeter
Uluguru Bush-shrike
Polynesian Ground-dove
Sichuan Jay
Mountain Serpent-eagle
Sulu Bleeding-heart
Zapata Rail
Mindoro Bleeding-heart
Negros Bleeding-heart
Black Stilt
Makira Moorhen
Great Indian Bustard
Abbott’s Booby
Kittlitz’s Murrelet
Titicaca Grebe
Greater Adjutant
Western Bristlebird
Eastern Bristlebird
Shore Plover
Udzungwa Forest-partridge
Madagascar Fish-eagle
White-bellied Heron
Subdesert Mesite
Long-whiskered Owlet
Philippine Cockatoo
Spix’s Macaw
South Island Wren
Crow Honeyeater
Northern Brown Kiwi
Banded Ground-cuckoo
Flores Hawk-eagle
Tachira Antpitta
Beck’s Petrel
Cebu Flowerpecker
Blue-eyed Ground-dove
Javan Trogon
Pulitzer’s Longbill
Alagoas Antwren
Pernambuco Pygmy-owl
Jamaica Petrel
Grenada Dove
Wood Snipe
Rio de Janeiro Antwren

Oral Zinc for the Common ColdOral Zinc for the Common ColdOral Zinc for the Common Cold

From the desk of Zedie.

Google Releases First Developer Resources For Project Ara, Its Modular Smartphone | TechCrunch

From the desk of Zedie.

Tamiflu: drugs given for swine flu ‘were waste of £500m’ – Telegraph

From the desk of Zedie.