Mystery behind large size of human brain unravelled

Agencies
May 25, 2018

Paris, May 25: The human brain is disproportionately large. And while abundant grey matter confers certain intellectual advantages, sustaining a big brain is costly — consuming a fifth of energy in the human body.

It is an oddity that has long flummoxed scientists: while most organisms thrive with small brains, or none at all, the human species opted to sacrifice a degree of body growth for more cerebral capacity.

The human brain, scientists say, expanded mainly in response to environmental stresses that forced our species to come up with innovative solutions for food and shelter, and pass the lessons on to our offspring.

The finding challenges a popular theory that the thinking organ grew as social interactions between humans became more complex, a research duo wrote in the Nature.

Ecological problem-solving

“The large human brain is more likely to stem from ecological problem-solving and cumulative culture than it is from social manoeuvering,” said paper co-author Mauricio Gonzalez-Forero of the University of St Andrews in Scotland.

From our ape-like Australopithecus ancestors to modern Homo sapiens, the human brain has tripled in size. But feeding such a big brain has been suggested to come at the cost of slow body growth in childhood — leaving our young dependent and vulnerable for longer than other animals.

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Agencies
July 7,2020

The World Health Organization (WHO) is reviewing a report that suggested its advice on the novel coronavirus needs updating after some scientists told the New York Times there was evidence the virus could be spread by tiny particles in the air.

The WHO says the Covid-19 disease spreads primarily through small droplets, which are expelled from the nose and mouth when an infected person breaths them out in coughs, sneezes, speech or laughter and quickly sink to the ground.

In an open letter to the Geneva-based agency, 239 scientists in 32 countries outlined the evidence they say shows that smaller exhaled particles can infect people who inhale them, the newspaper said on Saturday.

Because those smaller particles can linger in the air longer, the scientists - who plan to publish their findings in a scientific journal this week - are urging WHO to update its guidance, the Times said.

"We are aware of the article and are reviewing its contents with our technical experts," WHO spokesman Tarik Jasarevic said in an email reply on Monday to a Reuters request for comment.

The extent to which the coronavirus can be spread by the so-called airborne or aerosol route - as opposed to by larger droplets in coughs and sneezes - remains disputed.

Any change in the WHO's assessment of the risk of transmission could affect its current advice on keeping one-metre physical distancing. Governments, which also rely on the agency for guidance policy, may also have to adjust public health measures aimed at curbing the spread of the virus.

"Especially in the last couple of months, we have been stating several times that we consider airborne transmission as possible but certainly not supported by solid or even clear evidence," Benedetta Allegranzi, the WHO's technical lead for infection prevention and control, was quoted as saying in the New York Times.

WHO guidance to health workers, dated June 29, says that SARS-CoV-2, the virus that causes Covid-19, is primarily transmitted between people through respiratory droplets and on surfaces.

But airborne transmission via smaller particles is possible in some circumstances, such as when performing intubation and aerosol-generating procedures, it says.

Medical workers performing such procedures should wear heavy-duty N95 respiratory masks and other protective equipment in an adequately ventilated room, the WHO says.

Officials at South Korea's Centers for Disease Control said on Monday they were continuing to discuss various issues about Covid-19, including the possible airborne transmission. They said more investigations and evidence were needed.

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Agencies
July 25,2020

The COVID-19 pandemic and the subsequent lockdown saw many people turning chefs overnight, but those who could not turned to online delivery of food. And not just any food, as per a new report, Indians "craved the most for Biryani" during the lockdown.

The "StatEATistics report: The Quarantine Edition" from food delivery platform Swiggy found that Indians ordered biryani over "5.5 lakh times" from their favourite restaurants.

The new normal might have opened a pandora's box of behavioral changes, but some old habits die hard like the love for Biryani, which took the top spot for overall orders. It was followed by butter naan and masala dosa at 3,35,185 and 3,31,423, respectively.

Biryani has topped the list of most ordered dishes for the fourth year in a row, the food delivery platform noted.

Indians didn't forget to indulge their sweet tooth in the uncertain months of lockdown. Their favourite comfort food during the lockdown period was the moist and decadent Choco Lava cake, ordered around 1,29,000 times.

"The humble Gulab Jamun (84,558) and chic Butterscotch Mousse cake (27,317) followed suit," said the report derived from Swiggy's order analysis in the past few months across cities that it is present in.

Also, as birthday parties moved to video calls, and virtual cake cutting sessions, according to the food delivery platform, it delivered nearly "1,20,000 cakes" to complete these celebrations.

According to the report, on average, "65,000 meal orders" were placed by 8 pm each day to make sure food arrived in time for dinner.

"It was the busiest hour for Swiggy delivery partners and restaurants. On average, they (customers) chose to tip Rs.23.65, with one particularly generous customer tipping Rs. 2500!," it added.

For those who only relied on home-made food during the quarantine, Swiggy delivered a whooping 323 million kgs of onions and 56 million kgs of bananas through its grocery section and hence ensured that its consumers were all stocked up.

That said, it also took care of the 'quick-fix meal' tribe -- consumers who resort to the evergreen college hacks of living on instant noodles.

"Around 3,50,000 packets of this ideal easy to cook meal were ordered during the lockdown," it said.

In all, Swiggy delivered 40 million orders across food, groceries, medicines and other household items during India's lockdowns. It also delivered over 73,000 bottles of sanitizers and hand wash along with 47,000 face masks as the definition of essentials' changed during these uncertain times.

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Agencies
February 4,2020

Despite tremendous advances in treatment of congenital heart disease (CHD), a new global study shows that the chances for a child to survive a CHD diagnosis is significantly less in low-income countries.

The research revealed that nearly 12 million people are currently living with CHD globally, 18.7 per cent more than in 1990.

The findings, published in The Lancet, is drawn from the first comprehensive study of congenital heart disease across 195 countries, prepared using data from the Global Burden of Diseases, Injuries and Risk Factors Study 2017 (GBD).

"Previous congenital heart estimates came from few data sources, were geographically narrow and did not evaluate CHD throughout the life course," said the study authors from Children's National Hospital in the US.

This is the first time the GBD study data was used along with all available data sources and previous publications - making it the most comprehensive study on the congenital heart disease burden to date.

The study found a 34.5 per cent decline in deaths from congenital disease between 1990 to 2017. Nearly 70 per cent of deaths caused by CHD in 2017 (180,624) were in infants less than one year old.

Most CHD deaths occurred in countries within the low and low-middle socio-demographic index (SDI) quintiles.

Mortality rates get lower as a country's Socio-demographic Index (SDI) rises, the study said.

According to the researchers, birth prevalence of CHD was not related to a country's socio-demographic status, but overall prevalence was much lower in the poorest countries of the world.

This is because children in these countries do not have access to life saving surgical services, they added.

"In high income countries like the United States, we diagnose some heart conditions prenatally during the 20-week ultrasound," said Gerard Martin from Children's National Hospital who contributed to the study.

"For children born in middle- and low-income countries, these data draw stark attention to what we as cardiologists already knew from our own work in these countries -- the lack of diagnostic and treatment tools leads to lower survival rates for children born with CHD," said researcher Craig Sable.

"The UN has prioritised reduction of premature deaths from heart disease, but to meet the target of 'ending preventable deaths of newborns and children under 5 years of age,' health policy makers will need to develop specific accountability measures that address barriers and improve access to care and treatment," the authors wrote.

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