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Archives for: August 31, 2019

Spacecraft Could Save Earth from Asteroids

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first_img(PhysOrg.com) — British space engineers working for a space company in Stevenage in England, have designed a “gravity tractor” spacecraft to deflect any asteroids threatening to collide with Earth. The announcement comes only weeks after an asteroid collision scar around the size of Earth was detected on Jupiter. Explore further 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. Asteroid (2867) Steins. Image: ESA Citation: Spacecraft Could Save Earth from Asteroids (2009, September 4) retrieved 18 August 2019 from https://phys.org/news/2009-09-spacecraft-earth-asteroids.html A collision with an asteroid is a rare event, but scientists believe it is inevitable that sooner or later an asteroid will come close enough to be a real threat. In fact in 2004 an asteroid called Apophis caused alarm when scientists predicted there was a 1:37 chance of it hitting Earth in 2029, which is the greatest threat in recorded history. They later revised their figures but it could still be on course to collide in 2036. The US space agency, NASA estimates there are at least 1000 “potentially hazardous asteroids.”NASA is so concerned about the threat it has set up a monitoring program to track every space object that could be an asteroid on a collision course. They are so far tracking over 6,000 asteroids whose orbits bring them close to Earth, but there are an estimated 100,000 asteroids large enough to wipe out a city.A collision could be catastrophic, depending on how large the asteroid is and where it hits. A direct hit to a city by even a relatively small asteroid the size of a football field, for example, could completely destroy the city and kill millions of people. Many more could be killed by tsunamis triggered by the impact, and by dust and burning material thrown up into the atmosphere after the collision.The engineers, led by Dr Ralph Cordey, head of exploration and business at EADS Astrium, a British space company, have designed what they call a “gravity tractor”, a ten-tonne spacecraft around 100 feet long that could provide a practical way of averting a collision with Earth. The device would be launched as soon as an asteroid was found to be on course to crash into the planet, and would fly alongside it at a distance of about 160 feet away. The craft could divert an asteroid up to 430 yards in diameter, and an impact with an asteroid this size would release around 100,000 times the energy of the bomb dropped on Hiroshima in 1945.The gravity tractor is designed to draw the asteroid towards itself by exerting a small gravitational force on it. The spacecraft would then steer the asteroid away into an orbit away from Earth. The craft would use four ion thrusters, which are low energy and efficient, of the type commonly used on deep space probes. The ion thrusters enable the craft to adjust its position relative to the asteroid. The gravitational pull exerted by the asteroid would be enough to nudge the rock into a different, and less dangerous, trajectory.The process of steering the asteroid away from a collision course would take several years, with the craft changing the angle of trajectory by only a fraction of an inch over 15 years, but that is enough change to divert an asteroid. The spacecraft would need to be launched at least 15 (preferably 20) years before the predicted collision to give it time to adjust the asteroid’s trajectory away from Earth.The design team say the gravity tractor could be built fairly quickly with existing technologies, although a prototype has not yet been built. They have planned the details of the mission, and expect the cost could be shared by a number of governments if an asteroid on track to hit Earth was discovered, and international agreements would need to be drawn up.NASA published a paper earlier this year on the feasibility of using a gravity tractor for this purpose, and they concluded it could be extremely effective if there was enough warning. With scientists saying the asteroid Apophis could possibly be on a course to collide with Earth in 2036, perhaps we do have enough warning.© 2009 PhysOrg.com NASA Statement on Student Asteroid Calculationslast_img read more

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Team finds buckyballs grow larger by eating vaporized carbon

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first_img(Phys.org) — Fullerenes were first discovered back in 1985 by a team of physicists vaporizing graphite in helium gas, one class of which, the buckminsterfullerene (C60) named after Buckminster Fuller and his geodesic domes, forms into spherical, hollow cages that resemble soccer balls. Since that time, a lot of study has been done on and with so named buckyballs, yet no one has been able to figure out how exactly they form. Now, new research by one of the original discoverers of fullerenes, Harold Kroto and his team at Florida State University moves closer to that goal in finding that buckyballs grow larger when exposed to vaporized carbon. The team has written a paper describing their observations and have had it published in the journal Nature Communications. Buckyballs… throwing astronomers a curve Quantum chemical modelling of growth processes. Image (c) Nature Communications, doi:10.1038/ncomms1853 Explore further Because of their similarity to graphene, sheets of one atom thick carbon atoms that form hexagonal patterns, researchers have wondered if fullerenes might come into being after first existing as simple sheets that somehow warp to the degree that they form into balls. Unfortunately, no one has yet been able to create the right set of circumstances that have allowed them to witness the actual birth of a fullerene structure, though they have found that they also exist in nature as well, specifically in the soot that comes from burning candles, and near red giant stars or supernovae.Using a Fourier transform ion cyclotron resonance mass spectrometer, Kroto and his team were able to analyze what happens when buckyballs come to exist in the same space as vaporized carbon, they grow larger. They found that small fullerenes grew to buckyball size, and buckyball sized fullerenes grew into larger balls by “eating” or absorbing carbon atoms into their structure. They also found that the original structure was maintained by atoms being shifted around during the absorption process.In learning more about how fullerenes are formed, and now how they grow, researchers are able to apply new evidence to help explain other natural phenomenon, such as how they come to exist in space in such large quantities such as is found with carbon stars and supernovae and why their distribution in the lab is so similar to what is found in the soot produced by a burning candle. More information: Closed network growth of fullerenes, Nature Communications 3, Article number: 855 doi:10.1038/ncomms1853AbstractTremendous advances in nanoscience have been made since the discovery of the fullerenes; however, the formation of these carbon-caged nanomaterials still remains a mystery. Here we reveal that fullerenes self-assemble through a closed network growth mechanism by incorporation of atomic carbon and C2. The growth processes have been elucidated through experiments that probe direct growth of fullerenes upon exposure to carbon vapour, analysed by state-of-the-art Fourier transform ion cyclotron resonance mass spectrometry. Our results shed new light on the fundamental processes that govern self-assembly of carbon networks, and the processes that we reveal in this study of fullerene growth are likely be involved in the formation of other carbon nanostructures from carbon vapour, such as nanotubes and graphene. Further, the results should be of importance for illuminating astrophysical processes near carbon stars or supernovae that result in C60 formation throughout the Universe.via RSCcenter_img Journal information: Nature Communications Citation: Team finds buckyballs grow larger by ‘eating’ vaporized carbon (2012, May 30) retrieved 18 August 2019 from https://phys.org/news/2012-05-team-buckyballs-larger-vaporized-carbon.html © 2012 Phys.Org 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

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Long term satellite data offers insights into degree of global sensitivity to

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first_img Citation: Long term satellite data offers insights into degree of global sensitivity to climate change (2016, February 18) retrieved 18 August 2019 from https://phys.org/news/2016-02-term-satellite-insights-degree-global.html More information: Alistair W. R. Seddon et al. Sensitivity of global terrestrial ecosystems to climate variability, Nature (2016). DOI: 10.1038/nature16986AbstractThe identification of properties that contribute to the persistence and resilience of ecosystems despite climate change constitutes a research priority of global relevance1. Here we present a novel, empirical approach to assess the relative sensitivity of ecosystems to climate variability, one property of resilience that builds on theoretical modelling work recognizing that systems closer to critical thresholds respond more sensitively to external perturbations2. We develop a new metric, the vegetation sensitivity index, that identifies areas sensitive to climate variability over the past 14 years. The metric uses time series data derived from the moderate-resolution imaging spectroradiometer (MODIS) enhanced vegetation index3, and three climatic variables that drive vegetation productivity4 (air temperature, water availability and cloud cover). Underlying the analysis is an autoregressive modelling approach used to identify climate drivers of vegetation productivity on monthly timescales, in addition to regions with memory effects and reduced response rates to external forcing5. We find ecologically sensitive regions with amplified responses to climate variability in the Arctic tundra, parts of the boreal forest belt, the tropical rainforest, alpine regions worldwide, steppe and prairie regions of central Asia and North and South America, the Caatinga deciduous forest in eastern South America, and eastern areas of Australia. Our study provides a quantitative methodology for assessing the relative response rate of ecosystems—be they natural or with a strong anthropogenic signature—to environmental variability, which is the first step towards addressing why some regions appear to be more sensitive than others, and what impact this has on the resilience of ecosystem service provision and human well-being.Press release (Phys.org)—A team of researchers from several institutions in Norway and the U.K. has isolated the parts of our planet that appear to be the most sensitive to climate change using several years of satellite data. In their paper published in the journal Nature, the team describes their use of data covering the past 14 years and what their study revealed. Alfredo Huete with University of Technology Sydney offers a News & Views piece on the work done by the team and outlines the importance of such studies. Most climate scientists know that as the planet warms, some parts of it will change more than others—some will become drier, some wetter, and some will change so much they will become entirely new ecosystems. They also know that some parts of the world are more sensitive to a warming planet than others—the upper altitudes of big mountain ranges, for example, or the Arctic tundra are likely to be more sensitive than large desert areas. But, as Heute notes, what has been lacking is a way to define just how sensitive a place or ecosystem is, and then defining a means of applying an indicator of sorts to the various parts of the planet to allow for comparison. That is just what this new team has done, by poring over satellite data that revealed changes on the surface, such as more or less green, more or less rainfall, etc., they were able to chart which parts of the planet were showing how sensitive they were to the changes that have already occurred—they called their indicator ‘the vegetation sensitivity index’ and used it to create maps that showed the degree of sensitivity in various areas across the globe, which also of course, showed which parts are the most sensitive, e.g. parts of the boreal forest, alpine regions, prairies and steppe, the Arctic tundra, parts of central Asia and both North and South America; also the Caatinga and some of parts of Eastern Australia.Identifying the degree of sensitivity of various parts of the planet, Huete notes, is necessary for making plans to avoid irreversible damage to vital ecosystems and hopefully sustaining those that are most critical to our own survival. Global snapshot of the Vegetation Sensitivity Index (VSI), a new indicator of vegetation sensitivity to climate variability using satellite data between 2000-2013 at 5km resolution (Seddon et al. 2016). Areas in green (red) have comparatively lower (higher) vegetation sensitivity. Grey areas are barren land or ice covered. Inland water bodies as identified by the Global Lakes and Wetlands Database (Lehner & Döll, 2004), are mapped in blue. Credit: Seddon et al Explore furthercenter_img © 2016 Phys.org Journal information: Nature Tundra study uncovers impact of climate warming in the Arctic 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

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The spirit of the east

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first_imgOn that note, it is incontestably indicative that twenty-two reputable, senior artists from the Singapore Art Society (of Singapore) are collaborating with Art Spice Gallery in the capital city of India, in this intriguing, large-scale exhibition.Supported by prestigious names like Singapore Airlines, Singapore Embassy, Singapore Tourism Board, luxury car, Mercedes-Benz and a premium magazine, The Ideal Home and Garden; this is a stupendous collaboration that proves to be a monumental cultural exchange between magnificent India and the industrious Lion City. Also Read – ‘Playing Jojo was emotionally exhausting’In this exhibition, the 22 Singaporean artists, each with a unique style of paintings, are representatives of the ‘Nanyang’ spirit. The term ‘Nanyang’ is often used to denote the idea of a regional identity and culture for the overseas Chinese in Southeast Asia.  In it, ‘Nanyang’ artists express their personal unique painting styles in their artworks, often through a blend of multiple stylistic techniques of the East and West, resulting in a varied body of works unified by their focus on Southeast Asian subjects. Also Read – Leslie doing new comedy special with NetflixHaving grown up in Singapore during the developmental period, some of these artists have experienced the tensions between tradition and modernity, enabling them to incorporate these elements into their painting styles. Such is the essence of the ‘Nanyang’ spirit.Conquering the gap between traditional Chinese and Western influence, these iconic artists have brought the ‘Nanyang’ spirit into their art development, and has also achieved acclaim for their artistic excellence within the international art market. Thus, the remarkable collection of art in this exhibition is an engaging voyage into Singapore, with paintings and drawings that re-create multiculturalism, wherein, one cannot help but be fascinated by the incredible ease at which the nation embraces numerous ethnicities and related physical spaces, such as its very own Little India and Chinatown.Apart from Terence Teo Chin Keong (the current President of the Singapore Art Society), the other esteemed artists of the exhibition are Chan Chang How, Lim Choon Jin, P. Gnana, Low Puay Hua, Dr Ho Kah Leong, Wang Fei, Cheng Yoke Khoon, Seah Kang Chui, Koeh Sia Yong, Chiew Swee Fah, Eng Siak Loy, Lee Choon Kee, Ang Hiong Chiok, Wong Hai and Anne Lim Geok Kuan.WHEN: 12 to 21 MarchWHERE: Art Spice Gallery, Metropolitan Hotellast_img read more

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Defamation case Court exempts Rahul from personal appearance

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first_imgA magisterial court in Bhiwandi in Maharashtra’s Thane district on Tuesday granted exemption to Congress vice-president Rahul Gandhi from personal appearance in a case in which he has been accused of making defamatory references to RSS while campaigning during Lok Sabha polls.First Class Judicial Magistrate SV Swami granted Rahul’s prayer for exemption moved by his counsel citing his busy schedule due to assembly elections in Maharashtra and Haryana. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJISwami had directed the Congress leader to be present in the court on Tuesday in connection with a case filed by secretary of Bhiwandi unit of RSS Rajesh Kunte, who had claimed Rahul had ‘distorted history’ and ‘defamed’ the organisation by alleging that ‘RSS people had killed Mahatma Gandhi’.The court directed that Rahul be present himself before it on 7 January, the next date of hearing.The magistrate had on 11 July ordered processes to be issued against Rahul under Section 500 of the Indian Penal Code (defamation) to ensure his presence before the court for allegedly accusing RSS of killing Mahatma Gandhi, while addressing an election rally at Sonale village on 6 March.last_img read more

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Girl held for supplying drugs to Correctional Home inmate

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first_imgKolkata: A girl has been arrested from the Dum Dum Correctional Home on Wednesday after she tried to supply drugs to an under trail prisoner. She was later released on bail after being produced at a Barrackpore court.She has been identified as Susmita Malakar. According to the preliminary investigation, police suspect that the girl had an affair with the accused for a long time. She used to visit him at the correctional home and supply items frequently. Also Read – Heavy rain hits traffic, flightsThe accused Bhagirath Sarkar was arrested on the charges of murder that occurred under Nijpur police station in North 24-Parganas. According to sources, the girl, a resident of Duttapukur of the same district, visited the correctional home on Wednesday morning. She met the boy inside the jail.She told the security personnel that she had some items to hand over. It was learnt that when security check was going on some of the jail staff found that the girl was carrying drugs weighing around 295 gm. The matter was immediately reported to the local police station. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedPolice reached the spot and arrested the girl. During police interrogation, the girl pleaded her innocence saying that she has been framed.The lawyer of the girl has, however, claimed that she was going to meet her friend when someone had handed over a packet to her to pass it on to someone else. When she was about to hand over the item to the person, the correctional home security men intercepted her and recovered the drug from her possession. The lawyer argued in the court that the girl, a college student was not involved in any immoral activities. After hearing the plea the court granted her bail.last_img read more

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Beware Less sleep puts you at risk of compulsive Facebook use

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first_imgLong spells of bad night sleep do not only put you at the risk of developing day-long tiredness, crankiness or distraction but also lead to compulsive Facebook checking too, find researchers.The team from University of California-Irvine demonstrated that lack of sleep – in addition to affecting busy college students’ moods and productivity – leads to more frequent online activities such as browsing Facebook.“When you get less sleep, you’re more prone to distraction. If you’re being distracted, what do you do? You go to Facebook. It’s lightweight, it’s easy, and you’re tired,” said lead researcher and informatics professor Gloria Mark.The findings show a direct connection among chronic lack of sleep, worsening mood and greater reliance on Facebook browsing. Mark also found that the less sleep people have, the more frequently their attention shifts among different computer screens, suggesting heightened distractibility.Sleep deprivation can cause workplace mishaps and make drivers fall asleep.last_img read more

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Green themes abound in Durga Puja marquees

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first_imgKolkata: At a time when global warming and high pollution levels have emerged as major challenges for policy planners worldwide, a number of community Durga Puja organisers in and around Kolkata have come up with green themes to spread awareness about a clean environment among the public. Children and adults alike can enjoy the feeling of passing through a sanctuary at “Dinosaur Park” that has been simulated with high quality light and sound effects in Salt Lake City’s FD Block marquee, while the Beliaghata Sandhani club has protested against the killing of tigers and underscored the need for conservation of the big cat with its “Tarjon Garjon” (Roar of the Tiger) theme. Delivering a message about reusing plastics and not littering it everywhere, the “When Useless Becomes Useful” theme finds prominence in the marquee of Kankulia and Fern Road Community Durga Puja. Organisers of the Patuli community Durga Puja festival, on the other hand, have showcased “Go Green with Development” in the marquee. Dum Dum Park Sarbojonin’s marquee on the “Ujan thele Chalo nao, Pakhira bole moder praan bachao” (Row the boat upstream, birds are crying for their lives) theme is a telling reminder about the species of birds which are facing extinction due to radiation emitting from mobile towers and the destruction of their nests due to the felling of trees. The “Nirmal Bangla” (Clean Bengal) project has been highlighted by the Ashwininagar Bandhu Mahal Club, which has created a canvas using mostly nails. Dwelling on green themes presents a win-win scenario for organisers as they are usually big hits with the spectators, who empathise with the marquee’s concern about environmental degradation through the themes, which also bring in the prizes. Ten years ago, FD Block in Salt Lake had started the trend of promoting environment-related themes at community Puja marquees. Since then, green theme Pujas have been gradually changing the face of Bengal’s and perhaps India’s biggest carnival. “About 10 years back, environment-based themes in community Pujas were hardly noticed. But, the growing number of green themes over the past few years is not only encouraging but also instrumental in developing environment consciousness among school children and college goers,” Calcutta University’s Professor of Environment Sciences Aniruddha Mukhopadhyay said. Mukhopadhyay, who has been following the evolution of the environment-based themes since 2007, as a jury member of an award for green community Pujas — Serader Sera Nirmal Pujo Puroskar — said varied themes describing the menace of global warming, climate change, pollution, crop diversity and bio-diversity, conservation of forests, medicinal plants, the marine ecosystem and recycling of waste have made their presence felt at marquees across the city. Topics such as safety and disaster management have also been turned into Puja themes. Mukhopadhyay, however, called for the development of year-long green neighbourhood programmes in order to extend the boundaries, instead of remaining confined to the marquees. “Showcasing green themes during festive days and eco-friendly activities within the Puja premises will not be enough. The crucial thing is how the Puja organisers are able to transform the five-day green activities into actions for 365 days and extend the boundaries to entire the locality to make it sabuj para (green neighbourhood),” Mukhopadhyay told IANS. West Bengal Pollution Control Board Chairman Kalyan Rudra pointed out that the flipside of such a big carnival is that colossal waste, including of non-biodegradable material, is generated and electricity consumption surges as thousands of lights are installed in and around the marquees across the city during the festival days. Even trees are trimmed for displaying hoardings and advertisements. “It will be painful if the Puja organisers do not pay enough attention on these issues. This year, we are issuing an advisory to at least 200 community Pujas across districts to create awareness for environment protection. We have also urged the district administrations to take necessary action,” Rudra told IANS. Artists of Kumartuli — the city’s hub of idol makers — claim they use lead-free colour for painting the idols. Awareness about eco-friendly colour has been developed not only among idol makers, but also among consumers. However, mass-scale adoption of non-toxic paint is yet to be achieved in the absence of any checks and due to a lack of understanding of the cost-benefit analysis, said Krishnajyoti Goswami, Professor of Biochemistry at Malaysia’s Lincoln University College. “Idol makers are claiming that they use non-toxic paint. But who is monitoring this? Mass-scale adoption of eco-friendly colour is yet to be achieved. The unit price of lead-free colour is dearer compared to traditional dust colour but consumption of eco-friendly colour is much lower than that of the dust variety,” Goswami, who has been associated with the campaign for use of lead-free paint in idol making, told IANS.last_img read more

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Conquering Everest

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first_imgTen NCC girl cadets were felicitated by General Dalbir Singh, COAS, for successfully summiting Mt Everest, on Thursday afternoon at Vigyan Bhawan in the national Capital. This was the first NCC Girl Cadets expedition to have successfully scaled world’s highest peak.The event was also graced by Lt General Aniruddha Chakravarty, DG NCC, who expressed his gratitude and thanked the Ministry of Defence, The Indian Army, All India Radio and the Indian Air Force for their support to the expedition. Also Read – ‘Playing Jojo was emotionally exhausting’The expedition led by Col Gaurav Karki, a renowned mountaineer, comprised of cadets namely- Rigzen Dolker, Tashi Kaskit, Trishala Gurung, Staniz Laskit, Pooja Mehra, Baljeet Kaur, Lalrintluangi, Tsering Angmo, Sulaxchana Tamang and Kumari Nutan.The expedition succedded in two consecutive days as two batches comprising of five girls each, scaled the peak on May 21 at 11:00am and May 22 at 07:40am. The first batch was led by Col Gaurav Karki and Maj Deepika while the second batch, by Deputy expedition leader Lt Col Vishal Ahlawat. Also Read – Leslie doing new comedy special with NetflixGeneral Dalbir Singh, addressed the girls for their achievement and said that they had set an example for the future generations, and are an inspiration for everyone in the country. He said, “You have set an example for the younger generation and you are an inspiration to all the women in the nation.” He also requested the audience present, to give the team a standing ovation.As Col Gaurav Karki addressed the NCC cadets, he informed the audience about the strenuous procedure and training sessions the girls had undergone. A selected team of girl cadets had climbed to Mt Deo Tibba and Mt Trishul last year as part of an initial training. Later, ten selected cadets were given survival training for three weeks to endure the extreme cold conditions at Siachen Glacier in the beginning of this year. After these lengthy preparations the team set out for Everest in the month of March and successfully overcame their expedition without any casualties. Lalrintluangi, a bubbly 12th standard student form Mizoram, who had been a part of the expedition, smiled and said, “I felt beautiful being on top of the world, as I placed my bible and the flag of Mizoram at the peak of Mt Everest. This memory will be preserved in my mind forever.”last_img read more

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Youth shot dead by cousin brother over family dispute

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first_imgKolkata: A youth from Diamond Harbour was allegedly shot dead by his cousin brother over some dispute.The incident took place in the Netra area of Diamond Harbour area in South 24-Parganas on Monday night. The victim has been identified as Sabbir Gaji. The victim went to a fair near Diamond Harbour station on Monday evening. After visiting the fair, the victim was going to one of his relatives’ houses situated nearby. When Gaji was about to enter the house of his relative, his cousin brother Rakibul Gaji turned up there and took him to a house in the locality. Also Read – Rain batters Kolkata, cripples normal lifeAfter a few minutes the youths stepped into the room, locals heard the sound of a gunshot. They rushed to the spot only to find the victim lying in a pool of blood. The victim with a bullet injury was taken to Diamond Harbour District Hospital and was later shifted to a city hospital as his condition deteriorated. The patient succumbed to his injury on late Monday night. The incident triggered panic among locals residents in the Netra area. The family members of the victim lodged a complaint at the local police station against the cousin brother, Rakibul, and four others. On the basis of the complaint police have started a probe. They are yet to ascertain the exact cause that might have led to the murder. According to the preliminary investigation, police suspect that some family-related dispute might have caused the incident. Cops are investigating if the victim had any personal rivalry with his cousin brother. The investigating officers are interrogating the family members of the victim and police are conducting raids to nab the accused.last_img read more

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