Month: August 2019

  • Sterile neutrinos and the search for warm dark matter

    first_imgThese two figures show how intergalactic structures at high redshift look in cold dark matter (left) and warm dark matter (right) models. The size of the simulated region corresponds to 3.3 million light-years. In warm dark matter models, the structures are more diffused. Credit: Matteo Viel Matteo Viel, a research fellow at the Institute of Astronomy in Cambridge, England, believes that particle physics and cosmology could be more compatible as scientists work toward understanding the origins and the nature of our universe. Citation: Sterile neutrinos and the search for warm dark matter (2006, September 1) retrieved 18 August 2019 from https://phys.org/news/2006-09-sterile-neutrinos-dark.html And, with an international team that includes scientists from France and Italy, as well as a theorist from CERN in Switzerland, Viel has produced a paper that may just do that. It is titled “Can Sterile Neutrinos Be Ruled Out as Warm Dark Matter Candidates?”, and it addresses the possibility of a less-standard view of the universe. It was published in Physical Review Letters on August 17.“We know that dark matter is one of the main constituents of our universe,” Viel tells PhysOrg.com. “The most popular view is that this dark matter is mostly cold. And while some things can be explained by cold dark matter, there are some things, especially on a smaller scale, that are better explained by a dominance of warm dark matter.” Things, the Letter explains, like pulsar velocity kick, universe re-ionization at a high redshift. Warm dark matter, in the form of sterile neutrinos, could even possibly help with grand unification theories in particle physics.Viel and his colleagues studied a subset of data taken from the Sloan Digital Sky Survey (SDSS) to find differences in warm and cold dark matter. The subset included quasars that show the absorptions of the photons emitted by a distant source by the intervening neutral hydrogen which populate intergalactic structures. Using the SDSS data, Viel and his peers used computers to model different scenarios using warm and cold dark matter to get an idea of what objects in a forming universe might look like.Two figures show how intergalactic structures at high redshift look in cold dark matter (left) and warm dark matter (right) models. The size of the simulated region corresponds to 3.3 million light-years. In warm dark matter models, the structures are more diffused.“Among all warm dark matter particles,” says Viel, “there are neutrinos. Neutrinos come in two kinds: active and sterile. We quantify the impact of the sterile neutrinos on intergalactic structures when the universe was about 10% of its present age.”The problem, though, arrives in the fact that a group in Ohio, using observational data, discovered an upper limit to neutrino mass that is smaller than Viel and his group’s lower limit. This means that the findings are incompatible. So, does this result rule out sterile neutrinos as warm dark matter candidates? “Yes,” says Viel, “and no.”In a standard neutrino production scenario, there is leptonic symmetry. In such a universe, sterile neutrinos could not be dark matter candidates. But Viel and his team explored some new possibilities, including leptonic symmetry, and discovered that sterile neutrinos are still good candidates for warm dark matter. “What we need now,” he says, “are further parameters — tighter constraints — to study.”This is where a combination of particle physics and cosmology could really help. “This is really a work that lies between particle physics and cosmology,” he explains. By collecting higher resolution data on intergalactic structures, better constraints could be developed for particle physics experiments in the laboratory. “If we can find better constraints, the physics community can tailor experiments in those ranges that cosmologists have found. It is important for these communities to interact, bring data and share models of the universe.”“There are infinite numbers of consequences in the development of the universe, depending on warm or cold dark matter,” says Viel. “If we can get tighter constraints on even one property of sterile neutrinos, through some direct detection experiments or by observation, it would be an enormous improvement of our understanding of the universe.”By Miranda Marquit, Copyright 2006 PhysOrg.com Explore further Deceptively simple: Minute marine animals live in a sophisticated symbiosis with bacteria This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

  • British researchers find geese alter course to avoid wind farm

    first_img(Phys.org) — Researchers in Britain have found that migrating pink-footed geese have altered the path they take when returning to the UK to winter after flying southeast from Iceland, due to the construction of a wind farm. The study, conducted by Pawel Plonczkier and Ian Simms of Britain’s Food and Environment Research Agency was held over a four year period using radar following the final construction of an offshore wind farm near Lincolnshire. They found, as they note in their paper published in the Journal of Applied Ecology, that as the finishing touches were applied to the wind generators, the geese began taking an alternate route when looking to overwinter in the UK. © 2012 Phys.org More information: Radar monitoring of migrating pink-footed geese: behavioural responses to offshore wind farm development, Journal of Applied Ecology, DOI: 10.1111/j.1365-2664.2012.02181.x Citation: British researchers find geese alter course to avoid wind farm (2012, August 15) retrieved 18 August 2019 from https://phys.org/news/2012-08-british-geese-farm.html The findings offer some relief to ecological organizations who have feared that migrating geese and other birds would meet their death running into the giant blades used by wind generators if wind farms were erected in places where the birds were used to flying. This fear was compounded by the fact that geese find it difficult to change course in midflight and because they fly at night sometimes, making it more difficult of course, to see obstacles in their path.The researchers began their observations after the towers were built, but before the generators were added, back in 2007. They used radar to track the movements of approximately 40,000 geese as they migrated over a four year time frame. Initial results were difficult to gauge as Europe experienced some unusual weather patterns. Overall however, a pattern emerged as it became clear the birds were intentionally avoiding the wind farm, clearly understanding the danger it represented.The results don’t erase the fear of bird deaths from wind farms, of course, as the team studied just one species reacting to two nearly adjoining facilities, though it’s hard to argue with their results. In all they noted that the proportion of geese flying outside the wind farm zone during their observations rose from 52% to 81% and the majority of the geese that continued to fly through the zone altered their altitude to fly higher than the blades could reach.While this news is promising, more research will have to be conducted before ecologists gain a true understanding of just how much danger wind farms pose to migrating birds. A wind farm in South Australiacenter_img Journal information: Journal of Applied Ecology Explore further Conflict with farmers threaten geese This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

  • Bioengineering team creates selfforming tetrahedron protein

    center_img Imaging of the assembled TET12 reveals tetrahedral topology. Credit: Nature Chemical Biology (2013) doi:10.1038/nchembio.1248 More information: Design of a single-chain polypeptide tetrahedron assembled from coiled-coil segments, Nature Chemical Biology (2013) doi:10.1038/nchembio.1248AbstractProtein structures evolved through a complex interplay of cooperative interactions, and it is still very challenging to design new protein folds de novo. Here we present a strategy to design self-assembling polypeptide nanostructured polyhedra based on modularization using orthogonal dimerizing segments. We designed and experimentally demonstrated the formation of the tetrahedron that self-assembles from a single polypeptide chain comprising 12 concatenated coiled coil–forming segments separated by flexible peptide hinges. The path of the polypeptide chain is guided by a defined order of segments that traverse each of the six edges of the tetrahedron exactly twice, forming coiled-coil dimers with their corresponding partners. The coincidence of the polypeptide termini in the same vertex is demonstrated by reconstituting a split fluorescent protein in the polypeptide with the correct tetrahedral topology. Polypeptides with a deleted or scrambled segment order fail to self-assemble correctly. This design platform provides a foundation for constructing new topological polypeptide folds based on the set of orthogonal interacting polypeptide segments. Citation: Bioengineering team creates self-forming tetrahedron protein (2013, April 29) retrieved 18 August 2019 from https://phys.org/news/2013-04-bioengineering-team-self-forming-tetrahedron-protein.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

  • Progress finally being made on understanding ABC proof

    first_img Explore further Credit: Charles Rondeau/public domain Meeting of math minds fails to clear up ABC conjecture proof © 2016 Phys.org (Phys.org)—A team of mathematicians met last week at Kyoto University in another attempt to understand a proof unveiled almost four years ago by Shinichi Mochizuki—one that he claims offers a proof of the ABC conjecture. If the proof turns out to be verifiable, most in the field believe it will be a truly historical event.last_img read more

  • Music books and history

    first_imgThe Hungarian Information and Cultural Centre (HICC) in the Capital is all set to being the New year in high spirits. From film screenings to instrumental recitals, the month of January has a lot going on for those who appreciate Hungarian art.Ambassador to Bern (A berni követ), directed by Attila Szász  isa fictional account of the 1958 attack against the Hungarian embassy in Bern, the film is based on a true story about the aftermath of the 1956 Hungarian revolution.  Also Read – ‘Playing Jojo was emotionally exhausting’A tense, twist-filled drama plays out behind the closed doors of the embassy, and the international relations soon begin to boil: Hungary’s government demands immediate action, Swiss policemen surround the building and Hungarian immigrants demonstrate on the street. The film will be screened at HICC on January 15 at an event titled Fábri Film Club.Concert Tour: a series of flute and Piano recital by Dávid Simon and János Palojtay will go on from January 20 to February 1 in Delhi and other cities in the country. Also Read – Leslie doing new comedy special with NetflixDávid Simon (flutist, composer, educator) studied at the Ferenc Liszt Academy of Music, Budapest and at the University of Music and Theater. Since 1996, he has several national and international awards to his credit. As a composer, he has also won special prize of the Béla Bartók competition, organised for the young Hungarian composers. János Palojtay (pianist, soloist, improviser, and composer) began to play piano at the young age of five and began his training of talented students in music at the Ferenc Liszt Academy of Music, Budapest. He has won several International prizes and participated as a soloist in many international festivals. He is a part of the famous Ludwig Ensemble and has played with various well known orchestras and opera.Petofi Book Club at HICC will be held on January 22. January 22 is the Day of Culture in Hungary. It is the day, when Hungarian poet Ferenc Kölcsey (1790 – 1838) has finished the Himnusz, the verses of the Hungarian Anthem, in 1823. The music was composed by Ferenc Erkel (1810 – 1893) and is played by orchestra or sung, in each festive occasion. There will be a commemorative lecture by Ágnes Kirpalani as well.Cocos Nuciferas (India art fair), Spirit and Matter by MD Deleep (Marc Delorme) and by three woman artistes – Three Generations from Hungary is an art work exhibition to be held from January 27 to February 28.An amalgamated art show under the aegis of India Art Fair, represented by Marc Delorme (a French-Swiss artist) and an exhibition-cum-performance, curated by art historian, writer and curator Katalin Keseru , organised by art consultant Anna Bagyó with the participation of three Hungarian woman artists: Ilona Lovas, Anna Makovecz and Villo Turcsány.Open Day for Schools is a Children’s programme at HICC on January 30 by Johanna Balchandani.This exclusive programme for school children introduces Hungary in terms of its history, geography, people, art and culture.A short documentary film gives a brief snapshot of the country’s landscapes and a firsthand experience on the rich and vibrant culture of Hungary. The students may also get a chance to view the ongoing exhibition at the gallery of the Centre.last_img read more

  • Lohri delicacies

    first_imgThe restaurant is all set to delight the guests with its mouthwatering Punjabi fare throughout the week, from January 12-18. During this week long festival, a delectable variety of Punjabi food from soups till desserts will be served. Treat your taste buds with non-veg delicacies like Tangri Masala , Tawe Wala Keema Meat, Machchi Amritsar to veg delicacies like Cholia Paneer, Aloo Vadian, Kadhi Punjabi, Mah Chollian Di Dal etc. The dishes can be paired with the finest selection of spirits available at Paatra, to make one’s experience truly memorable! Also Read – ‘Playing Jojo was emotionally exhausting’Jaypee Hotels, one of the finest hospitality groups in India was established in 1981. It is a division of the conglomerate, Jaiprakash Associates Ltd. Presently the group has five luxury properties, strategically located to service the needs of discerning business and leisure travelers. In New Delhi, the group has two hotels: Jaypee Siddharth and Jaypee Vasant Continental.Where: Paatra, Jaypee Greens Golf and Spa Resort When: 12 January to 18 January 2015 Price: A la Carte menu.last_img read more

  • Body of patient found hanging

    first_imgKolkata: Mystery shrouds the death of a patient whose body was found hanging inside the toilet of the ESI Hospital in Uluberia, where he had been undergoing treatment for the past few days.The victim has been identified as Amar Pramanik. The family members of the victim staged a demonstration outside the hospital alleging negligence on the part of the hospital authorities. The incident triggered tension among the patients in the hospital. Senior police officers rushed to the spot to bring the situation under control. Also Read – Heavy rain hits traffic, flightsA resident of Chandipur area of Uluberia, Pramanik was admitted to the hospital with abdominal pain on last Thursday. Some of the staff members of the hospital found the patient hanging. They immediately informed the police who later rescued the victim. He was later declared dead by the doctors.The hospital authorities reported the matter to the family members of the victim. They rushed to the hospital and staged a protest demonstration. They alleged that the patient was not given adequate treatment in the hospital. After the patient was admitted to the hospital, the patient was not given proper attention by the doctors. As a result of this, the health condition of the patient deteriorated. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThis resulted in frustration inside the patient, which might have prompted him to take such a drastic step.The demonstration was later lifted following the intervention of the senior police officers of the district. They promised the agitated family members of the victim that the matter would be looked into. Police assured them that action will be taken against the accused if any negligence is found. Police have started a probe in this regard and are probing all possible angles into the incident.last_img read more

  • Rajasthan artisanship on display

    first_img10 master painters from Rajasthan will display their contemporary work from February 13-19 in the national Capital. Over 100 paintings will be on display, some from the private collections of the painters. The exhibition, which has been curated by Durgesh Shankar, is an unique exhibition celebrating diversity and folklore. It is a week-long event which will see the best of artworks from the sand dunes of Rajasthan under one roof.The participating artists include Shilp Guru Pradip Mukherjee, Padma Shri S. Shakir Ali, Shilp Guru Nand Kishore Sharma, Shilp Guru Reva Shankar Sharma, National Awardees Shammi Sharma (Shammi ‘Bannu’), Ramu Ramdev, Kalyan Joshi, Trilok Prakash Soni, Raja Ram Sharma; along with Kuldeepak Soni. Also Read – ‘Playing Jojo was emotionally exhausting’Among the works for sale would be Rajasthani phad paintings (originally narrative scrolls on long canvas pieces, since miniaturised and painted on cloth/canvas or paper), pichwais (large paintings intended to provide a backdrop to the idol of Sri Nathji, to depict a festival or mood) and Rajasthan, Mughal and Persian miniature paintings. The paintings have been made using traditional methods and natural colours.Curator of the event-Durgesh Shankar is a retired member of Central Board of Direct Taxes and Special Secretary to the government of India, who has always had a keen interest in fine arts and is smitten by rich heritage of Rajasthan and the vibrancy of Rajasthani art.  Also Read – Leslie doing new comedy special with Netflix“An artist, through his art, is essentially telling a story. Excellence in art therefore means, to me, how well he is able to communicate the story to you, his audience. The stories they choose to tell, the images they conceive, the lines they draw and embellish with colours, will inextricably draw you into their web. Enjoying a work of art is a highly individualistic experience. If it makes you turn around just so you can see it once more, then the artist has succeeded in his work. For if a mere look can transport you away from the humdrum of life, then it is, in my view, a great piece of art”, said Durgesh Shankar. “Rajasthan has perhaps experienced these influences more than others, and has subsumed them in every aspect of their lives, including art.  In this exhibition, through the 10 artists of diverse genre, who are acknowledged as masters in their fields, and who are working quietly in remote corners of the State, churning out masterpieces, I wish to introduce their work to the audience in Delhi, so that people can admire and enjoy the fine brush-work, the magic of the natural colors and the vivid portrayal of themes known to us since childhood but again presented to us on a modern palette,” he added.last_img read more