Scientists create bacterium with fewest number of genes
Researchers report the making of a living, replicating and stable cell that uses the minimum number of genes — 437 — to be considered biologically ‘alive.’
42, according to The Hitchhiker’s Guide To The Galaxy, is the answer to the “ultimate question of Life, the Universe, and Everything” but a team of biologists has shown that a better answer, to the ultimate question of life at least, maybe 473.
In Friday’s edition of the journal Science, researchers J. Craig Venter and Clyde Hutchinson and colleagues at the Venter Institute, California, report the making of a living, replicating and stable cell that uses the minimum number of genes — 437 — to be considered biologically ‘alive.’ In the natural world, no living organism is ever known to possess fewer than 1000 genes. The knowledge gained from this creation may be foundational to understand how organisms can be created from scratch.
Ever since the human genome — the complete sequence of genes that make up human DNA — was deciphered at the turn of the century, researchers have tried to understand the precise functions of these 25,000 genes and the way they network with other pieces of DNA in the cell to keep it functional.
Their efforts dovetail with the fundamental question of whether there is a minimum number of genes without which a cell would be dead. That question is also of immense practical interest as there is an entire subfield — called synthetic biology — that’s modifying bacteria and other microorganisms at the level of genes to make organic machines that can be employed to, for instance, clear oil spills and industrial enzymes. To build complex organisms would mean having a fine-grained understanding of why some genes are more essential than others. Scientists have sought to study bacteria of theMycoplasma genus — as it has relatively few genes and multiplies quite quickly — to analyse the relationship between genes and the chemical pathways they make.
From Syn 1.0 to Syn 3.0
In 2010, Mr. Venter and his team built and booted up the first self-replicating, synthetic bacterial cell (called Syn 1.0) through the sole chromosome (the storehouse of a cell’s DNA) of Mycoplasma mycoides — a bacterium with a relatively small genome — and transplanted it into Mycoplasma capricolum, from which they had previously extracted the DNA.
The hollowed-out capricolum was re-programmed to behave like a mycoides; proof that genomes can be designed in the computer, chemically made in the lab, and transplanted into a recipient cell to produce a new, self-replicating cell controlled only by the synthetic genome. For its present work, the team reviewed scientific literature on the functions of each of the genes of Syn 1.0 and tried to remove every gene that didn’t seem essential. That, however, didn’t yield a stable cell.
Simultaneously, another team — through trial and error — sliced and diced the genome of Syn 1.0 and then identified which of its original 901 genes could be done away with. The final product of this stable cell with 473 genes is Syn 3.0. Intriguingly, they cannot yet explain why 149 of Syn 3.0’s 473 genes are essential to the survival of their test bacterium. “The JCVI-syn3.0 platform (as the software version of the test bacterium version is called) represents a versatile tool for investigating the core functions of life,” the authors said in their paper.
The next step would be to add genes, one by one, to this stripped-down genome and then see its effects on the constitution of the cell. “We are not claiming that this is the ultimate minimal genome,” Mr. Venter told Science.
Describing the research as a “huge contribution”, Mukund Thattai, a synthetic biologist at the Bengaluru-based National Centre for Biological Sciences, said the paper was significant because it showed up significant gaps in science’s understanding of how something as fundamental as a cell worked. He said that a reading of the paper revealed the ambition and effort that is required to build artificial genomes and test their viability. But, he cautioned, this did not mean that science was closer to making so-called artificial life in the laboratory. “Finding a precise answer to making a so-called minimal genome is an extremely important theoretical question…there is still too much unknown.”
Keywords:
human genome,
sequence of genes,
human DNA Beetle gives chemical cues to ward off mates
Reuters
The burying beetle Nicrophorus vespilloides.
The female burying beetle employs an ‘anti-aphrodisiac’ when she is caring for offspring
When a female “burying beetle” is focused on caring for babies and not making new ones, she releases a chemical signal to her libidinous mate that says in no uncertain terms, “Honey, I’m not in the mood.”
Scientists described on Tuesday how these females employ an anti-aphrodisiac chemical during a three-day period critical for raising offspring to tell the male she is temporary infertile and prevent him from trying to copulate.
The study focused on a beetle species, Nicrophorus vespilloides, known for burying carcasses of small animals like birds and rodents as food for their larvae.
It provides insight into how animals change their behaviour to provide care for their young, in this instance favouring parenting over sexual activity to produce new offspring.
“Our study helps to understand animal family life and how it is coordinated between family members,” said biologist Sandra Steiger of Germany’s University of Ulm, who led the study published in l Nature Communications.
“It is kind of intriguing that such mechanisms exist in animals and that animal parents synchronise their mating and parental-care behaviour for their own benefit and that of the children,” Ms. Steiger added. — Reuters
New Mars gravity map reveals useful details
Resaerchers with the help of NASA spacecrafts have developed a new map of mars gravity. Photo by Specal Arrangement
A better knowledge of the planet’s gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars.
Researchers have developed a new map of Mars’ gravity with three NASA spacecraft that is the most detailed to date, providing a glimpse into the hidden interior of the Red Planet.
“Gravity maps allow us to see inside a planet, just as a doctor uses an X-ray to see inside a patient,” said Antonio Genova from Massachusetts Institute of Technology (MIT).
The new gravity map will be helpful for future Mars explorations, because a better knowledge of the planet’s gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars.
“Furthermore, the improved resolution of our gravity map will help us understand the still-mysterious formation of specific regions of the planet,” Genova added.
The improved resolution of the new gravity map suggests a new explanation for how some features formed across the boundary that divides the relatively smooth northern lowlands from heavily cratered southern highlands.
Also, the team confirmed that Mars has a liquid outer core of molten rock by analysing tides in the Martian crust and mantle caused by the gravitational pull of the sun and the two moons of Mars.
Finally, by observing how Mars’ gravity changed over 11 years — the period of an entire cycle of solar activity — the team inferred the massive amount of carbon dioxide that freezes out of the atmosphere onto a Martian polar ice cap when it experiences winter.
They also observed how that mass moves between the south pole and the north pole with the change of season in each hemisphere.
The map was derived using data collected by NASA’s Deep Space Network from three NASA spacecraft in orbit around Mars: Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO).
Like all planets, Mars is lumpy, which causes the gravitational pull felt by spacecraft in orbit around it to change.
For example, the pull will be a bit stronger over a mountain, and slightly weaker over a canyon.
The gravity field was recovered using about 16 years of data that were continuously collected in orbit around Mars.
“With this new map, we’ve been able to see gravity anomalies as small as about 100 kms across and we’ve determined the crustal thickness of Mars with a resolution of around 120 kms,” said Genova in a paper published in the journal Icarus.
The better resolution of the new map helps interpret how the crust of the planet changed over Mars’ history in many regions.
Keywords:
NASA,
Mars,
spacecraft Study says Malaria first spread from birds
Malaria started out as a parasite in birds, then evolved to colonise bats, and from there spread to other mammals, says a new study on the evolution of the parasite found.
Malaria affects around 500 million people every year, but humans are not the only ones - different species of malaria parasite can infect birds, bats, and other mammals too, researchers said.
“We cannot begin to understand how malaria spread to humans until we understand its evolutionary history. In learning about its past, we may be better able to understand the effects it has on us,” said Holly Lutz from Cornell University in the US.
Malaria is a parasitic single-celled organism that reproduces in the bloodstream of its host and is transferred between hosts by insects like mosquitoes. Different species of malaria live in different species of host animals.
Blood samples to identify mutations
Researchers took blood samples from hundreds of East African birds, bats, and other mammals and screened the blood for the parasites. When they found malaria, they took samples of the parasites’ DNA and sequenced it to identify mutations in the genetic code.
From there, they were able to perform what is called “phylogenetic analysis” to determine how different malaria species are related.
In analysing the genetic codes of the malaria parasites, researchers were able to find places where the DNA differed from one species to the next.
Then, they used powerful computing software to determine how the different species evolved and how they are related to each other.
This phylogenetic analysis relied on large sample sizes and DNA from many different host species of bats and birds, because otherwise, the picture would be incomplete, researchers said.
“Trying to determine the evolutionary history of malaria from just a few specimens would be like trying to reconstruct the bird family tree when you only know about eagles and canaries,” said Lutz.
“There is still more to discover, but this is the most complete analysis of its kind for malaria to date,” she said.
The analysis showed that malaria has its roots in bird hosts, from which it spread to bats, and then on to other mammals.
“It is not that bats are spreading malaria - we get different species of malaria than they do, and we cannot get it from them. Instead, by looking at patterns of mutations in the DNA of the different malaria species, we are able to see when it branched off from one host group into another,” said Lutz.
“It started out as a parasite in birds, and then it evolved to colonise bats, and from there, it is evolved to affect other mammals,” she said.
The findings were published in the journal Molecular Phylogenetics and Evolution.
Keywords:
Malaria,
new study Cassini reveals tallest peaks at Saturn s moon Titan
Titan’s tallest peak is 10,948 feet high and is found within a trio of mountainous ridges called the Mithrim Montes.
In a nod to extraterrestrial mountaineers of the future, scientists working on NASA’s Cassini mission have identified the highest point on Saturn’s largest moon Titan.
Titan’s tallest peak is 10,948 feet high and is found within a trio of mountainous ridges called the Mithrim Montes.
The researchers found that all of Titan’s highest peaks are about 10,000 feet in elevation.
The study used images and other data from Cassini’s radar instrument, which can peer through the obscuring smog of Titan’s atmosphere to reveal the surface in detail.
“It’s not only the highest point we’ve found so far on Titan, but we think it’s the highest point we’re likely to find,” said Stephen Wall, deputy lead of the Cassini radar team at NASA.
Most of Titan’s tallest mountains appear to be close to the equator.
The researchers identified other peaks of similar height within the Mithrim Montes, as well as in the rugged region known as Xanadu.
“As explorers, we’re motivated to find the highest or deepest places partly because it’s exciting. But Titan’s extremes also tell us important things about forces affecting its evolution,” added Jani Radebaugh, a Cassini radar team associate at Brigham Young University in Utah.
Mountains and cliffs on Earth usually are found in locations where forces have shoved the surface upward from underneath.
The Himalaya and Andes Mountains are examples of places where interior forces are at work today.
Cassini has found that Titan also has rain and rivers that erode its landscape.
According to Radebaugh, the process probably proceeds much more slowly on Titan than on the Earth because, at 10 times Earth’s distance from the sun, there is less energy to power erosive processes in the moon’s atmosphere.
The fact that Titan has significant mountains suggests that some active tectonic forces could be affecting the surface, for example, related to Titan’s rotation, tidal forces from Saturn or cooling of the crust.
The next step for the researchers will be trying to figure out what could produce such tall peaks on an icy ocean world. “There is lot of value in examining the topography of Titan in a broad, global sense, since it tells us about forces acting on the surface from below as well as above,” said Radebaugh.
The results were presented at the 47th annual lunar and planetary science conference in Texas on Thursday.
Keywords:
Saturn,
Cassini Mission,
Cassini flyby,
Titan,
NASA,
Solar System Ancient virus DNA lies dormant in humans
A significant portion of what we think of as our “human” DNA actually came from viruses, and a new discovery suggests that our DNA is even less human than scientists previously thought.
Nineteen new pieces of non-human DNA — left by viruses that first infected our ancestors hundreds of thousands of years ago — have just been found lurking between our own genes.
And one stretch of newfound DNA, found in about 50 of the 2,500 people studied, contains an intact, full genetic recipe for an entire virus, said the scientists.
Whether or not it can replicate, or reproduce, is not yet known. But other studies of ancient virus DNA have shown it can affect the humans who carry it.
About eight per cent of what we think of as “human” DNA actually came from viruses, said the study published in the journal PNAS.
Soon, clothes that can clean themselves with light
The process developed by the team has a variety of applications for catalysis-based industries.
A spot of sunshine is all it could take to clean your clothes within minutes, as scientists, including those of Indian-origin, have developed a low-cost, efficient way to grow nanostructures on textiles that can degrade organic matter when exposed to light.
The research from RMIT University in Australia paves the way towards nano-enhanced textiles that can spontaneously clean themselves of stains and grime simply by being put under a light bulb or worn out in the Sun.
The process developed by the team has a variety of applications for catalysis-based industries such as agrochemicals, pharmaceuticals and natural products, and could be easily scaled up to industrial levels.
3D structure
“The advantage of textiles is they already have a 3D structure so they are great at absorbing light, which in turn speeds up the process of degrading organic matter,” Rajesh Ramanathan from RMIT University said.
“There’s more work to do to before we can start throwing out our washing machines, but this advance lays a strong foundation for the future development of fully self-cleaning textiles,” he said.
The researchers including Dipesh Kumar and Vipul Bansal, also from RMIT University, worked with copper and silver-based nanostructures, which are known for their ability to absorb visible light.
When the nanostructures are exposed to light, they receive an energy boost that creates “hot electrons.” These “hot electrons” release a burst of energy that enables the nanostructures to degrade organic matter.
The challenge for researchers has been to bring the concept out of the lab by working out how to build these nanostructures on an industrial scale and permanently attach them to textiles.
The team’s approach was to grow the nanostructures directly onto the textiles by dipping them into a few solutions, resulting in the development of stable nanostructures within 30 minutes.
When exposed to light, it took less than six minutes for some of the nano-enhanced textiles to spontaneously clean themselves.
“Our next step will be to test our nano-enhanced textiles with organic compounds that could be more relevant to consumers, to see how quickly they can handle common stains like tomato sauce or wine,” Mr. Ramanathan said.
The research was published in the journal Advanced Materials Interfaces.
Keywords:
Nano-enhanced textiles,
RMT University,
Australia NASA cargo mission with key science supplies on way to ISS
This investigation will help to study fire, meteors, regolith, adhesion and 3D printing in microgravity.
Carrying 7,500 pounds (3,400 kg) of key science research, the Orbital ATK Cygnus spacecraft is currently on it way to the International Space Station (ISS).
Lifted off aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on Wednesday, the Orbital ATK Cygnus spacecraft has a new EVA spacesuit, clothing, food, spare parts and several key research.
According to the US space agency, the lift-off occurred under perfect weather conditions and without any technical difficulties.The flight will deliver investigations to the space station to study fire, meteors, regolith, adhesion and 3D printing in microgravity.
The “Saffire-I” investigation will provide a new way to study a realistic fire on an exploration vehicle, which has not been possible in the past because the risks for performing such studies on manned spacecraft are too high.
Instruments on the returning Cygnus will measure flame growth, oxygen use and more.
Results could determine microgravity flammability limits for several spacecraft materials, help to validate NASA’s material selection criteria, and help scientists understand how microgravity and limited oxygen affect flame size.
A less heated investigation called “Meteor Composition Determination” will enable the first space-based observations of meteors entering Earth’s atmosphere from space, the US space agency said in a statement.
Study of properties
A more “grounded” Strata-1 probe will study the properties and behaviour of regolith - the impact-shattered “soil” found on asteroids, comets, the Moon and other airless worlds.
From grounded to gripping, another investigation launching takes its inspiration from small lizards. The “Gecko Gripper” investigation tests a gecko-adhesive gripping device that can stick on command in the harsh environment of space.
Once adhered, the gripper can bear loads up to 20 pounds. The gripper can remain in place indefinitely and can also be easily removed and reused.
From adhesion to additive, the new Additive Manufacturing Facility (AMF) will also be part of the cargo. Additive manufacturing (3D printing) is the process of building a part layer-by-layer, with an efficient use of the material.
The facility is capable of producing parts out of a wide variety of space-rated composites, including engineered plastics.
The ability to manufacture on the orbiting laboratory enables on-demand repair and production capability, as well as essential research for manufacturing on long-term missions.
Keywords:
NASA,
International Space Station,
ISS,
Orbital ATK Cygnus IISc scientists find a novel method to kill cancerous cells
Scientists at the Indian Institute of Science, Bengaluru, have found a novel way to kill cancerous cells by using iron-based compounds “decorated” with organic groups. Red light acts as a switch that turns these compounds on and off. Like a Trojan horse, the organic molecule directs the compound into the mitochondria of cancerous cells, and the light-sensitive iron-based compound (inorganic iron (III) catecholates) generates reactive oxygen species when exposed to red light. The reactive oxygen species so generated destroy the mitochondria, thus killing the cancerous cells. The results, based on in vitro studies, were published recently in the European Journal of Inorganic Chemistry.
“Red light is used because the longer wavelength enables it to penetrate the skin deeper,” said Prof. Akhil Chakravarty from the Department of Inorganic and Physical Chemistry. “Normal cells don’t allow the compound to get in but cancerous cells do and we have taken advantage of this.”
The reason for targeting mitochondria is because unlike nuclear DNA that repairs itself when damaged by drugs, mitochondria have no repair mechanism. So cells die once the mitochondria are damaged. According to the paper, mitochondrial dysfunction is implicated in tumorigenesis and thereby makes it a popular target for the development of various cytotoxins.
“We saw very good activity. Almost all cancerous cells were destroyed when red light was used. We have to next undertake studies in animals,” he said. Cancerous cells from the cervix, lung and skin were tested. Since the procedure relies on the ability of the red light to penetrate the skin, only certain cancers can be targeted. “We are mainly bothered about oral cancer and skin cancer. Using endoscopy and colonoscopy we can take red light inside the body and achieve similar results,” he said sounding very optimistic.
“Photodynamic therapy (PDT) is a relatively new mode of cancer treatment, which depends on the retention of the photosensitizers in the tumour cells followed by their selective activation under red light in the presence of molecular oxygen. Photosensitizers are light-sensitive compounds that cause localized oxidative damage within the target cells upon irradiation,” notes the paper.
Keywords:
IISc,
killing cancerous cells,
cancer therapy Dept. of Biotechnology launches fund to tackle anti-microbial resistance
The move is to encourage biotechnology start-ups as well as tackle the threat faced by India from resistance to antimicrobial drugs.
In a move to encourage biotechnology start-ups as well as tackle the threat faced by India from resistance to antimicrobial drugs, the Department of Biotechnology (DBT) — through the Biotechnology Industry Research Assistance Council (BIRAC) — has invested an initial $1,00,000 to start an India-focussed seed fund to help groups in India compete for the Longitude Prize. This is a £ 10 million prize offered by Nesta, a U.K. charity, to any individual group anywhere in the world that develops an affordable, effective diagnostic test to detect resistance to microbes.
Renu Swarup, Managing Director, BIRAC, said the collaborations were to encourage more biotechnology start-ups out of India. “BIRAC, since its inception, has supported several social entrepreneurs and we are committed to creating an atmosphere where innovation is encouraged and nurtured,” she said. BIRAC is supported by the DBT.
India faces increasing instances of tuberculosis patients being resistant to front line drugs. Experts say this is due to lax monitoring and profligate prescription by medical authorities that allow these drugs to be easily available. Indiscriminate usage means that bugs are, overtime, able to resist these medicines. The World Health Organisation statistics for 2014 give an estimated incidence figure of 2.2 million cases of TB for India out of a global incidence of 9 million, with instances of drug-resistant TB rapidly rising.
Alongside Nesta, BIRAC also inked collaboration with Tekes, the Finnish funding agency, to improve competitiveness of Indian and Finnish industries through promoting collaboration in different phases of the knowledge innovation chain and it is teaming up with Horticulture Innovation Australia (HIA) for a joint funding programme to support innovative technologies for sustainable horticulture at a global level.
Last December, the DBT laid out a strategy whereby biotechnology would be at the foundation of a $100-billion industry by 2025, rising from the current $7-$10 billion.
Four missions
The National Biotechnology Development Strategy, as it is called, expects to launch four missions in healthcare, food and nutrition, clean energy and education; create a technology development and translation network across India with global partnership.
Keywords:
antimicrobial drugs,
bio-technology startups New ultra-sensitive test for cancer, HIV developed
The chemists have replaced the standard flag with short strand DNA while testing for cancer. Photo: Special Arrangement
TOPICS
health
disease
health treatment
health
This test is more effective than the current diagnostics.
A new ultra-sensitive test has been designed to detect diseases including HIV and cancer, it may prove 10,000 times more effective than current diagnostic tools, say Stanford scientists.0
When a disease - whether it is a cancer or a virus like HIV - begins growing in the body, the immune system responds by producing antibodies.
Fishing these antibodies or related biomarkers out of the blood is one way that scientists infer the presence of a disease.
This involves designing a molecule that the biomarker will bind to, and which is adorned with an identifying “flag.”
Through a series of specialised chemical reactions, known as an immunoassay, researchers can isolate that flag, and the biomarker bound to it, to provide a proxy measurement of the disease.
The new technique, developed in the lab of Carolyn Bertozzi, a professor of chemistry at Stanford University in U. S. augments this standard procedure with powerful DNA screening technology.
The chemists have replaced the standard flag with a short strand of DNA, which can then be teased out of the sample using DNA isolation technologies that are far more sensitive than those possible for traditional antibody detections.
“This is spiritually related to a basic science tool we were developing to detect protein modifications, but we realised that the core principles were pretty straightforward and that the approach might be better served as a diagnostic tool,” said Peter Robinson, a graduate student in Bertozzi’s group.
The researchers tested their technique, with its signature DNA flag, against four commercially available, U.S. Food and Drug Administration (FDA)- approved tests for a biomarker for thyroid cancer.
It outperformed the sensitivity of all of them, by at least 800 times, and up to 10,000 times, researchers said.
By identifying the biomarkers of disease at lower concentrations, physicians could theoretically detect the diseases in the earlier stages.
“The thyroid cancer test has historically been a fairly challenging immunoassay, as it produces a lot of false positives and false negatives, so it was not clear if our test would have an advantage,” Robinson said.
A clinical trial underway in collaboration with the Alameda County Public Health Laboratory will help evaluate the technique as a screening tool for HIV, researchers said.
Early detection and treatment of the virus can help ensure that its effects on the patient are minimised and reduce the chance that it is transmitted to others.
“In contrast to many new diagnostic techniques, this test is performed on pre-existing machines that most clinical labs are already familiar with,” said Cheng-ting Tsai, a graduate student in Bertozzi’s group.
The research was published in the journal ACS Central Science.
Keywords:
Cancer treatment,
research,
DNA screening technology Nine monster stars detected by Hubble
Astronomers working with data from the NASA/Hubble space telescope have identified nine massive “monster” stars, each of which is more than 100 times the mass of the sun. These massive stars are located in the Tarantula Nebula, within the Large Magellanic Cloud. This structure is 1,70,000 light years away; one light year measuring a distance of approximately 9 trillion kilometres.
R136, the star cluster within the Tarantula Nebula is just a few light years wide and is known to host some of the most massive, luminous stars in the universe. The energy of these stars is mostly radiated in the ultraviolet range. So, the scientists had to take the images given by the Wide Field Camera 3 of the space telescope and use the high ultraviolet spatial resolution of the Space Telescope Imaging Spectrograph to analyse light from the R136 cluster, in an unprecedented manner.
While there were dozens of stars exceeding 50 solar masses, there were only nine stars that were over 100 times the mass of the Sun. Together, light from these nine stars alone outshines the Sun by a factor of 30 million.
Extensively studied by Paul Crowther of University of Sheffield, U.K., R136, was thought of as one star, the brightest object in the Magellanic Cloud, as noted by the Radcliffe Observatory of South Africa. Later it was recognised to be made up of separate units by the European Southern Observatory, which classified it into three components R136a, b and c. Of these, R136a was identified as consisting of eight stars, which the NASA/ESA denoted as a star cluster, in 1993. In 2010, Dr. Crowther and collaborators understood that R136 contained four massive stars. Thenew finding tells us that there are, in fact, nine massive stars in this cluster.How do these monsters originate? That is a question for astronomers to ponder over.
Keywords:
NASA/Hubble,
Tarantula Nebula,
R136 Abel prize for ‘stunning proof’
Andrew Wiles, British mathematician, has won the 2016 Abel prize for his “stunning proof of Fermat’s last theorem by way of the modularity conjecture for semistable elliptic curves, opening a new era of mathematics,” (to quote from the citation). Awarded by the Norwegian Academy of Science and Letters, the Abel prize is an international award given for outstanding scientific work in the field of mathematics, including mathematical aspects of computer science, mathematical physics, probability, numerical analysis, scientific computing, statistics and also mathematical applications in the sciences.
Fermat’s last theorem, which looks deceptively simple, is the statement that the equation xn + yn = zn, where x, y and z are positive whole numbers, has no solution for n larger than 2. In what can only be described as tenacious, Professor Wiles worked on this single problem for nearly a decade before making a breakthrough, in the process having to develop a lot of mathematics. Efforts to solve the problem go back 350 years: Pierre de Fermat first formulated the theorem in the 17th century, and he himself proved the claim for n = 4; Leonhard Euler proved the case of n = 3 and Sophie Germain generalised it to infinitely many prime exponents. While Ernest Kummer’s attempts led to major revelations, the bounty of a full proof eluded all concerned until Professor Wiles proved it in 1994. R. Balasubramanian, a well-known number theorist and former director of Institute of Mathematical Sciences, Chennai, declares his happiness at the award to professor Wiles: “He more than deserves the award, and I can’t think of anyone else who is better qualified [for the award]. It is a herculean task and he worked on this problem alone for the last ten years!... he proved the Shimura-Taniyama-Weil conjecture to the extent needed and for this he had to develop a lot of mathematics… which has applications to the Diophantine equations,” he says.
A story of Wiles' pursuit of thesolution, well known among mathematicians, can be narrated: While at Princeton, Andrew Wiles started his work on this problem and for seven years worked alone, in his attic, without telling anyone and after seven years, announced that he had solved it, in a conference in Cambridge, U.K., only to have a serious mistake pointed out by a colleague a few months later. He was not to be outdone and with help from his former student Richard Taylor, he patched up the gap and proved it successfully a year later. “Many people believe that if only he had been less than 40 years , he would have surely won the Fields Medal. This is a fantastic proof,” says Prof. Balasubramanian. According to an article in Nature, the two papers he published on this work in 1995 took up the entire issue of Annals of Mathematics.
“His work has made it easier to study elliptic curves and modular forms. It is a step ahead towards the Langlands programme,” says Prof. Balasubramanian, naming some sought-after areas of mathematics. Professor Wiles now aims to work on the Birch and Swinnerton-Dyer conjecture — a problem which has a million dollar prize attached. It is one of the seven millennium problems, only one of which, the Poincare conjecture, has been solved by Grigori Perelman, so far.
One cannot help but recall John Nash here who won the prize last year, and also that once the prize has gone to an Indian-origin mathematician Srinivasa Varadhan.
Keywords:
Andrew Wiles,
Abel Prize Space around Pluto nearly dust free: NASA
Studying the microscopic dust grains can give researchers clues about how the solar system was formed billions of years ago and how it works today
Space environment around Pluto and its moons is almost empty, containing only about six dust particles per cubic mile, according to data collected by a student-built instrument riding on NASA’s New Horizons spacecraft.
The spacecraft found only a handful of dust grains, the building blocks of planets, when it whipped by Pluto at about 49,000 kilometres per hour July last year, scientists said.
“The bottom line is that space is mostly empty,” said Fran Bagenal, a professor at University of Colorado Boulder, who leads the New Horizons Particles and Plasma Team.
“Any debris created when Pluto’s moons were captured or created during impacts has long since been removed by planetary processes,” said Bagenai, a faculty member at the Laboratory for Atmospheric and Space Physics (LASP).
Studying the microscopic dust grains can give researchers clues about how the solar system was formed billions of years ago and how it works today, providing information on planets, moons and comets, said Bagenal.
Launched in 2006, the New Horizons mission was designed to help scientists understand better the icy world at the edge of our solar system, including Pluto and the Kuiper Belt.
A vast region thought to span more than a billion miles beyond Neptune’s orbit, the Kuiper Belt is believed to harbour at least 70,000 objects more than 96 kilometres in diameter and contain samples of ancient material created during the solar system’s violent formation some 4.5 billion years ago.
The Student Dust Counter (SDC) logged thousands of dust grain hits over the spacecraft’s nine year, 3 billion-mile journey to Pluto while most of other six instruments slept, said Professor Mihaly Horanyi from LASP.
“Now we are starting to see a slow but steady increase in the impact rate of larger particles, possibly indicating that we already have entered the inner edge of the Kuiper Belt,” said Horanyi, the principal investigator for the SDC.
The dust counter is a thin film resting on a honeycombed aluminium structure the size of a cake pan mounted on the spacecraft’s exterior.
A small electronic box functions as the instruments “brain” to assess each individual dust particle that strikes the detector, allowing the students to infer the mass of each particle.
“Our instrument has been soaring through our solar system’s dust disk and gathering data since launch,” said Jamey Szalay, a former CU—Boulder student, now postdoctoral researcher at Southwest Research Institute (SwRI).
“It’s going to be very exciting to get into the Kuiper Belt and see what we find there,” said Szalay.
The research was published in the journal Science.
Keywords:
NASA,
Pluto,
Dust free planet A look into planet formation
The star, called HL Tau, is about a million-years-old
Astronomers studied the new images of a young star taken by the Karl G. Jansky Very Large Array (VLA) and said it reveals very early stages of planet formation.
The scientists used the VLA to see unprecedented detail of the inner portion of a dusty disk surrounding the star, nearly 450 light years from Earth.
The star and its disk were studied in 2014 with Atacama Large Millimeter/submillimeter Array (ALMA), which produced what astronomers then called the best image ever of planet formation in progress, National Radio Astronomy Observatory posted online on Thursday.
The ALMA image showed gaps in the disk, presumably caused by planet-like bodies sweeping out the dust along their orbits.
This image showed in real life what theorists had proposed for years. However, scientists were surprised to see this phenomenon because the star, called HL Tau, is only about a million years old — very young by stellar standards.
The ALMA image showed details of the system in the outer portions of the disk, but in the inner portions, nearest to the young star, the thicker dust is opaque to the short radio wavelengths received by ALMA.
The new VLA images revealed a distinct clump of dust in the inner region of the disk that contains roughly three to eight times the mass of Earth.
“We believe this clump of dust represents the earliest stage in the formation of protoplanets, and this is the first time we have seen that stage,” said Thomas Henning from Max Planck Institute for Astronomy (MPIA).
“This is an important discovery, because we have not yet been able to observe most stages in the process of planet formation,” said Carlos Carrasco-Gonzalez from the Institute of Radio Astronomy and Astrophysics (IRyA) in Mexico.
This region, the scientists said, is presumably where Earth-like planets would form, as clumps of dust grow by pulling in material from their surroundings. Eventually, the clumps would gather enough mass to form solid bodies that would continue to grow into planets.
Keywords:
ALMA,
planet formation,
VLA China to adopt national standard on lab animal welfare
The draft, which is available for public opinion until Sunday, is expected to greatly improve the welfare of laboratory animals in China.
China is set to adopt its first national standard on laboratory animal welfare and ethics by the end of this year, the media reported on Friday.
The draft, which is available for public opinion until Sunday, is expected to greatly improve the welfare of laboratory animals in China, according to Sun Deming, chairman of the Welfare and Ethics Committee of the Chinese Association for Laboratory Animal Sciences.
“Although all users of laboratory animals are required to conduct welfare and ethics reviews, they adopt different standards, and some are too lax,” said the China Daily quoteing Sun
The draft includes requirements for the production, transportation and use of laboratory animals, including qualifications for personnel, animal-raising facilities and the use of animals in testing.
Qin Chuan, the association’s president, said the lack of legislation has become a roadblock for the development of China’s multi-billion biological and pharmaceutical industries and other industries related to the use of laboratory animals.
The new standard, aims to minimise the use of animals and also their pain, integrates the latest concepts and requirements for the ethical treatment of lab animals, Sun said.
It has been recognised by leading experts at home and abroad, Sun said during the two-day Sino-British Third International Seminar on Laboratory Animal Welfare and Ethics.
The conference in Hefei, Anhui province, which was co-hosted by the association and the British government, ended on Thursday.
Keywords:
animal welfare,
national standard,
China New golden frog species found in Colombia
At seven-tenths of an inch long, it is among the smaller species in the group.
Researchers have discovered a new species of pale-gold coloured frog in the cloud forests of the high Andes in Colombia.
Its name, Pristimantis dorado, commemorates both its colour (dorado means ‘golden’ in Spanish) and El Dorado, a mythical city of gold eagerly sought for centuries by Spanish conquistadores in South America.
“The Spaniards assumed Colombia’s wealth was its gold, but today we understand that the real riches of the country lie in its biodiversity,” said one of the researchers Andrew Crawford from Smithsonian Tropical Research Institute (STRI) in Panama.
The new species was found calling from bushes along a roadside at about 8,700 feet elevation near Chingaza National Park, roughly 10 miles east of Bogota, Colombia’s capital and largest city.
Its discovery so close to a metropolitan area of nearly 10 million inhabitants illustrates how much of the planet’s biodiversity remains to be discovered.
“With this new species, Colombia now hosts 800 species of amphibians, second only to Brazil in total diversity,” Mr. Crawford said.
The findings were described in the journal Amphibia-Reptilia.
The extraordinarily diverse group to which the new species belongs, Pristimantis, includes 465 recognised species, 205 of them from Colombia.
At seven-tenths of an inch long, the new species is among the smaller species in the group. The largest species grow to be two inches in length, the researchers said.
Males of many frog species advertise for females with distinctive calls produced by vocal sacs or vocal slits. Oddly, although the new species lacks these structures, males are still able to produce calls consisting of an irregularly pulsed series of clicks, the study pointed out.
Keywords:
New frog species,
Pristimantis,
Chingaza National Park,
Andes
