3D images show what lies beneath Mars poles

January 4, 2017

Washington, Jan 4: Scientists using data from a NASA probe have unveiled 3D subsurface images of Mars polar ice caps, showing previously obscured layering, larger volume of frozen carbon dioxide and bowl-shaped features that may be buried impact craters.mars

The information will help scientists better understand Martian climate changes and may allow them to determine the age of the polar caps without using climate models.

The 3D data volumes were assembled from observations by the Shallow Radar (SHARAD) onboard NASA's Mars Reconnaissance Orbiter (MRO) during more than 2000 orbit passes over each Martian pole.

"We have applied industry-developed techniques in a very novel fashion to a martian dataset, producing 3D volumes that are each over 600 times larger than any terrestrial or planetary dataset of this kind," said Nathaniel E Putzig, a senior scientist at the Planetary Science Institute in the US.

"It is gratifying to see so plainly in the SHARAD volumes structures that took years of effort to characterise with the single-orbit profiles," Putzig said.

Layering seen at the surface of the martian polar caps has been studied for decades. It has long been thought to represent a record of climate changes on that planet.

The interior structures of the caps remained a mystery until the arrival of radar sounders at Mars in the last decade.

An early version of the north polar 3D volume helped to assess the quantity of water ice transferred to the polar caps in the most recent retreat from a martian ice age.

First looks at the south polar 3D volume indicate that previously mapped deposits of carbon dioxide ice are somewhat larger than reported.

In both polar 3D volumes, known impact craters in and near the polar caps that are partially filled with ice have distinctive bowl-shaped signatures in the radar data, and similar signatures are found elsewhere within the polar ices but without any surface expression.

Whether the latter structures truly are impact craters remains to be determined.
Age estimates of planetary surfaces throughout the solar system rely on statistical data for impact craters on the Moon's surface calibrated to radiometrically dated samples returned during the Apollo programme.

This method has been used to estimate the surface ages of the martian polar caps, but estimates for the ages of the caps themselves have had to rely on numerical models of past climate changes.

If a sufficient number of the bowl-shaped features found in the radar volumes are shown to be impact craters, scientists will be able to assess the age of the polar caps using cratering statistics alone.

The extent to which age estimates from this new volumetric method agree or disagree with those from climate models will have important implications for the accuracy of these dating techniques.

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Agencies
January 22,2020

New Delhi, Jan 22: "Don't get into a trap. Your security is in your hands," the Border Security Force (BSF) has said issuing its social media rules for its officers and men. It has directed them not to use 42 mobile applications and show caution while using Facebook, Twitter and WhatsApp.

"Be cautious while using social media," said the BSF in a circular issued recently.

"Before using WhatsApp, Facebook, Twitter and other social media platforms, one needs to keep in mind that you are border guarding force and Central Civil Services (Conduct) Rules rule duly are applicable," it said.

It further pointed out that by commenting/writing about or forwarding unverified reports and rumours one violates laws of land.

"Several times unverified reports would be presented in way that they are absolutely true and start believing it. Seeing such post always use your commonsense and never get into the trap (sic.)," it state adding that the anti-national elements uses social media to propagate their agenda to cause unrest in India.

A picture clicked by Border Security Force personnel and posted on a social media platform remains there for always. Therefore, one should use officially approved pictures about any incident or untoward incidents related to Border Security Force, stated the circular. It pointed that unauthorised persons should not engage into taking pictures of the incidents.

It also highlighted how through social media, a few BSF personnel have fallen into trap of espionage racket carried out by enemy countries.

"Our security and respect is in our hands. Always think twice whether you are doing correct by accepting friendship requests from unknown persons, especially women and girls," it cautioned the troopers and officers.

It also highlighted that while going on leave and joining back the force, always follow the rules and regulations laid out for safety and security. "This is for your own safety," it stressed in the end.

The BSF has also issued a list of 42 mobile applications that needs to be completely avoided by serving BSF officers and jawans.

They are MI store, Weibo, Wechat, Shareit, Truecaller, UC News, UC Browser, Beautyplus, NewsDog, Viva Video - QU video Inc, Parallel Space, Apus Browser, Perfect Corp, Virus Cleaner - HI Security Lab, CM browser, MI Community, DU recorder, Vault Hide - No mobile Security, Youcam Makeup, Cachecleaner DU Apps Studio, DU battery saver, DU privacy, 360 security, DU Browser,Clean master - Cheeta Mobile, Baidu Translate, Wonder Camera - Bindu Inc, ES Ifle Explorer, Photo Wonder, QQ international , QQ music, QQ Mail, AA player, QQ News Feed, Wesync, QQ security Center, Selfie City, Mail Master, Mi Video Call -Xaomi and QQ launcher.

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News Network
June 18,2020

Beijing, Jun 18:  Besides washing hands and wearing masks, it is also important to close the toilet lid before flushing to contain the spread of COVID-19, as per a new study.

According to a new study cited by The Washington Post, scientists who simulated toilet water and airflows, have found that flushing a toilet can generate a plume of virus-containing aerosol particles that is widespread and can linger in the air long enough to be inhaled by others. The novel coronavirus has been found in the faeces of COVID-19 patients, but it remains unknown whether such clouds could contain enough virus to infect a person.

"Flushing will lift the virus up from the toilet bowl," co-author Ji-Xiang Wang, who researches fluids at Yangzhou University in Yangzhou, China, said in an email. Wang stressed that bathroom users "need to close the lid first and then trigger the flushing process" and wash hands properly if the closure is not possible. As one flushes the toilet with the lids open, bits of faecal matter swish around so violently that they can be propelled into the air, become aerosolised and then settle on the surroundings.

Experts call it the "toilet plume".Age-old studies have been made to understand the potential for airborne transmission of infectious disease via sewage, and the toilet plume's role. Scientists who have seeded toilet bowls with bacteria and viruses have found contamination of seats, flush handles, bathroom floors and nearby surfaces. This is one reason we are told to wash our hands after visiting the toilet. Public bathrooms are well known to contribute to the spread of viruses that transmit via ingestion, such as the noroviruses that haunt cruise ships. However, their role in the transmission of respiratory viruses has not been established, said Charles P Gerba, a microbiologist at the University of Arizona."The risk is not zero, but how great a risk it is, we do not know. The big unknown is how much virus is infectious in the toilet when you flush it ... and how much virus does it take to cause an infection," said Gerba, who has studied the intersection of toilets and infectious disease for 45 years.

A study published in March in the journal Gastroenterology found significant amounts of coronavirus in the stool of patients and determined that viral RNA lasted in faeces even after the virus cleared from the patients` respiratory tracts. While another study in the journal Lancet found coronavirus in faeces up to a month after the illness had passed.

Scientists around the world are now studying sewage to track the spread of the virus. According to the researchers, the presence of the virus in excrement and the gastrointestinal tract raises the prospect of transmission via toilets, because many COVID-19 patients experience diarrhoea or vomiting.

A study of air samples in two hospitals in Wuhan, China found that although coronavirus aerosols in isolation wards and ventilated patient rooms were very low, "it was higher in the toilet areas used by the patients".The Centers for Disease Control and Prevention (CDC) says it remains "unclear whether the virus found in faeces may be capable of causing COVID-19," and "there has not been any confirmed report of the virus spreading from faeces to a person".For now, the CDC characterises the risk as low based on observations from previous outbreaks of other coronaviruses such as severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS). Wang decided to use computer models to simulate toilet plumes while isolating at home, as per Chinese government orders and thinking about how a fluids researcher "could contribute to the global fight against the virus".

Published in the journal Physics of Fluids, the study found that flushing of both single-inlet toilets, which push water into the bowl from one port, and annular-inlet toilets, which pour water into the bowl from the rim's surrounding edge with even greater energy, results in "massive upward transport of virus".

Particles can reach heights of more than three feet and float in the air for more than a minute, it found. The paper recommends not just lid-closing and hand-washing, it urges manufacturers to produce toilets that close and self-clean automatically. It also suggests that toilet-users should wipe down the seat. Gerba, however, said seats should not be a major concern.

Research has found that public and household toilet seats are typically the cleanest surfaces in restrooms, he said, probably because so many people already wipe them off before using them. Also, he said of SARS-CoV-2, the virus that causes COVID-19, "I don't think it's butt-borne, so I don`t think you have to worry."Gerba, who has been studying coronavirus transmission for two decades to investigate the role of a toilet flushing in a SARS outbreak stresses "flush and run" when using a public toilet without a lid. Gerba also said that people should wash hands well post-flushing and use hand sanitiser after leaving the restroom. "Choose well-ventilated bathrooms if possible and do not hang around the restroom in any case," added Gerba.

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Agencies
April 17,2020

New Delhi, Apr 17: The Indian Railways turned 167 years old on Thursday and for the first time ever, its trains did not carry any passengers on its birthday and instead stood idle in the yards waiting for the nationwide lockdown to end.

On this day 167 years ago, the wheels of the first passenger train in the country from Mumbai to Thane started rolling.

In 1974, Indians experienced life without trains for the first time. In May 1974 during the strike of the railways that lasted for around three weeks, drivers, station masters, guards, track staff and many others went on 'chakka jam' demanding fixed working hours for train drivers and an across-the-board pay hike.

"I can recall those times vividly. I remember that our leader George Fernandes had almost secured a deal with the then railway minister, but it fell through when it was taken to the then Prime Minister Indira Gandhi," All India Railwaymens Federation General Secretary Shiv Gopal Mishra, who was an apprentice in the railways at that time, told PTI.

"Fernandes was arrested in Lucknow. The workers went through a lot at that time. But those were days that angry workers had refused to give in and took great risks to get their demands met," he said.

However, just like this time, four decades ago too freight trains carrying essential supplies were run and the unions agreed to let some passenger trains run on the trunk routes like the Kalka Mail from Howrah to Delhi.

"Never ever in its history, there has been such a long interruption of services. Not during the World Wars, not during the 1974 railway strike, or any other national calamity or natural disaster," a railway spokesperson said.

The first Indian Railways passenger train was flagged off on April 16, 1853, from Mumbai to nearby Thane.

On Thursday, the Railway Ministry wished the railways a happy birthday on Twitter - "Today, 167 years ago with the zeal of 'never to stop' the wheels of the first passenger train from Mumbai to Thane started rolling. For the first time, passenger services are stopped for your safety. Stay indoors & make the nation victorious," it said.

Railway has suspended all passenger services since March 25 till May 3 due to the coronavirus outbreak. Around 15,523 trains run by the railways have been affected including 9,000 passenger trains and 3,000 mail express services which are run daily. It caters to over 20 million passengers every day.

According to the Union health ministry, the death toll due to coronavirus rose to 414 and the number of cases to 12,380 in the country on Thursday.

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