Knowledge Update

New York, July 20 (IANS) Ants belonging to a South American group switched from a hunter-gatherer lifestyle to subsistence farming of fungi that grew on decomposing, woody plant matter some 55 to 60 million years ago, shortly after the dinosaurs died out, new research has found.

By contrast, humans began subsistence farming around 10,000 years ago, progressing to industrialised agriculture only in the past century. 

The genes of the ant farmers and their fungal crops revealed a surprisingly ancient history of mutual adaptations, said the study published in the journal Nature Communications.

This evolutionary give-and-take led to some species -- the leafcutter ants, for example -- developing industrial-scale farming that surpasses human agriculture in its efficiency, the researchers said.

Much of the research on fungus-farming ants came from scientists working in Panama through the Smithsonian Tropical Research Institute, headquartered in Panama City, during the past 25 years. 

The key chapters of the history of ant agriculture were written into the genes of both the insects and their crop fungi. 

"The ants lost many genes when they committed to farming fungi," said Jacobus Boomsma, Research Associate at Smithsonian Tropical Research Institute.

This tied the fate of the ants to their food -- with the insects depending on the fungi for nutrients, and the fungi increasing their likelihood of survival if they produced more nutritious crop. 

"It led to an evolutionary cascade of changes, unmatched by any other animal lineage studied so far," Boomsma, who is also a biology professor at the University of Copenhagen in Denmark.

The researchers found that leafcutter ant species cut and sow their underground farms daily with fresh, green plant matter, cultivating a fully domesticated species of fungus on an industrial scale that can sustain colonies with up to millions of ants.

Put in human terms, Boomsma said, the leafcutter ants' success is akin to people figuring out how to grow a single, all-purpose, disease-, pest- and drought-resistant superfood at an industrial scale, "by the time of the ancient Greek civilisation."

New York, July 20 (IANS) In addition to environmental benefits, shifting away from inefficient and polluting fuel-based lighting -- such as candles, firewood, and kerosene lanterns -- to solar-LED systems can spur economic development as well -- to the tune of two million potential new jobs, a study says.

The researchers analysed how the transition from polluting fuel-based lighting to solar-LED lighting would impact employment and job creation.

"People like to talk about making jobs with solar energy, but it's rare that the flip side of the question is asked -- how many people will lose jobs who are selling the fuels that solar will replace," said researcher Evan Mills from Lawrence Berkeley National Laboratory (Berkeley Lab).

The University of California manages Berkeley Lab for the US Department of Energy's Office of Science.

"We set out to quantify the net job creation. The good news is, we found that we will see many more jobs created than we lose," Mills noted.

The findings were published in the journal Energy for Sustainable Development.

There are about 274 million households worldwide that lack access to electricity.

But Mills' study focused on the "poorest of the poor", or about 112 million households, largely in Africa and Asia, that cannot afford even a mini solar home system, which might power a fan, a few lights, a phone charger, and a small TV.

Mills found that fuel-based lighting today provides 150,000 jobs worldwide. 

Because there is very little data in this area, his analysis is based on estimating the employment intensity of specific markets and applying it to the broader non-electrified population. He also drew on field observations in several countries to validate his estimates.

He did a similar analysis for the emerging solar-LED industry and found that every one million of these lanterns provides an estimated 17,000 jobs.

These values include employees of these companies based in developing countries but exclude upstream jobs in primary manufacturing by third parties such as those in factories in China. 

Assuming a three-year product life and a target of three lanterns per household, this corresponded to about two million jobs globally, more than compensating for the 150,000 jobs that would be lost in the fuel-based lighting marke, the study said.

Furthermore, Mills' research found that the quality of the jobs would be much improved. 

"With fuel-based lighting a lot of these people are involved in the black market and smuggling kerosene over international borders, and child labour is often involved in selling the fuel," he said. 

"These new solar jobs will be much better jobs -- they're legal, healthy, and more stable and regular," he added.

The new jobs span the gamut, from designing and manufacturing products to marketing and distributing them.

​New York, July 20 (IANS) A child's brain should get enough and healthy activation even before they enter pre-school for the proper development of learning as well as memory functions, suggests a study.

The research reveals the significance of learning experiences over the first two-to-four years of human life, also known as "critical periods". 

In these periods memories are believed to be quickly forgotten in a phenomenon known as infantile amnesia -- the inability of adults to retrieve episodic memories that took place during the first two-to-four years of life.

"Our findings reveal us that children's brains need to get enough and healthy activation even before they enter pre-school," said lead author Cristina Alberini, Professor at New York University in the US.

"Without this, the neurological system runs the risk of not properly developing learning and memory functions," Alberini added.

Focussing on the brain's hippocampus -- a region of the brain necessary for encoding new episodic memories, the researchers found that the mechanisms of "critical periods" are fundamental for establishing these infantile memories.

During this critical period the hippocampus learns to become able to efficiently process and store memories for long-term.

If the hippocampus was inactive, the ability of younger rats to form latent memories and recall them later by reminders as they got older was diminished. 

"Early in life, while the brain cannot efficiently form long-term memories, it is 'learning' how to do so, making it possible to establish the abilities to memorise long-term," Alberini explained. 

"However, the brain needs stimulation through learning so that it can get in the practice of memory formation -- without these experiences, the ability of the neurological system to learn will be impaired," Alberini noted.

In the study, which appears in the journal Nature Neuroscience, the team compared rats' infantile memory with that when they reached 24-days-old -- when they are capable of forming and retaining long-term memories and at an age that roughly corresponded to humans at six to nine years old.

The infantile memory formation in rats pointed out to the importance of critical periods in early-life learning on functional development of the brain.

Using learning and environmental interventions during a critical period in life may significantly help to address learning disabilities, the researchers concluded.

​London, July 20 (IANS) Last month was the hottest June ever recorded worldwide, and the 14th straight month that global heat records were broken, scientists say.

Global sea temperatures were fractionally higher than for June last year while land temperatures tied, BBC quoted the US National Oceanic and Atmospheric Administration (NOAA) as saying.

Its global temperature records date back 137 years, to 1880.

Most scientists attribute the increases to greenhouse gas emissions.

They also say climate change is at least partially to blame for a number of environmental disasters around the world.

The combined average temperature over global land and ocean surfaces for June was 0.9 C above the 20th Century average of 15.5 C, the NOAA said in its monthly report.

Last year was the hottest on record, beating 2014, which had previously held the title.​

New York, July 17 (IANS) Researchers have created a comprehensive molecular atlas of brain development in non-human primate that could shed crucial light on what makes human brain development distinct.

This analysis uncovered features of the genetic code underlying brain development in our close evolutionary relative, while revealing distinct features of human brain development by comparison.

"This is the most complete spatiotemporal map we have for any mammal's development, and we have it in a model system that provides directly meaningful insight into human brain development, structure, and function," said Ed Lein, investigator at Allen Institute for Brain Science, a US-based non-profit medical research organisation.

"This exceptional dataset is useful for exploring precisely where and when genes are active in relation to the events of brain development and the onset of brain disorders," Lein noted in an analysis of the atlas published in the journal Nature.

The study is based on the US National Institutes of Health (NIH) Blueprint Non-Human Primate (NHP) Atlas, a publicly available resource created by the Allen Institute and colleagues at the University of California, Davis and the California National Primate Research Centre.

The goal of the NHP atlas was to marry the techniques of modern transcriptomics with the rich history of anatomical developmental studies by measuring gene activity at a series of ten important stages in prenatal and postnatal brain development.

At each stage, a technique called laser microdissection was used to precisely isolate fine layers and nuclei of cortical and subcortical brain regions associated with human psychiatric disease, thereby creating a high resolution time series of the generation and maturation of these brain regions and their underlying cell types.

The authors collaborated with colleagues at the Baylor College of Medicine to use this molecular map to pinpoint when and where candidate genes for diseases like autism and schizophrenia become active.

"This tremendous resource is freely available to the research community and will guide important research into the etiology of many developmental disorders for years to come," Michelle Freund, programme officer at National Institute of Mental Health, noted.​

Washington, July 18 (IANS) As we wait for Juno's first close-up images of Jupiter on August 27, NASA continues to explore our solar system to help answer fundamental questions about how we came to be, where we are going and whether we are alone in the universe.

“Juno is the latest example of the extraordinary science we have to look forward to right in our own solar system,” said Jim Green, Director of NASA Planetary Division.

“There are many uncharted, promising worlds and objects we are eager to explore with our current and future missions,” he added in a statement.

In September, NASA will launch OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) - the first US mission to a near-Earth asteroid (Bennu) to collect a sample for return to Earth in 2023.

OSIRIS-REx will help unlock secrets of the history of our solar system, and shed light on how life may have come to be on our planet.

The James Webb Space Telescope (Webb telescope), set to launch in 2018, can observe not only faint objects across the universe but also our neighbouring planets and their moons within our solar system.

Webb’s angular and spectral resolution will allow us to observe these targets with unprecedented sensitivity and even follow geologic activity.

With Juno exploring Jupiter, NASA is also intrigued by its largest moons.

Io’s intense geological activity makes it the most volcanically active world in the solar system, something Webb could potentially follow-up with.

The US space agency has selected nine science instruments for a future mission to investigate whether Europa -- a mysterious moon that scientists believe to have a liquid ocean beneath its icy surface -- hosts habitable environments.

Hubble, with its suite of upgraded instruments, has captured Jupiter’s auroras and found evidence of saltwater on Jupiter’s largest moon, Ganymede.

The mission has been extended another five years, and NASA expects it to continue to provide excellent science.

“NASA’s Cassini spacecraft continues exploring Saturn, its rings and moons, as it has since 2004. In 2017, during the final phase of its long mission, Cassini will complete 22 dives through the narrow gap between Saturn's outer atmosphere and its rings,” the statement read.

Titan is one of the major satellites of Saturn, with a rich atmosphere and surface chemistry that has been observed extensively by Cassini and ESA's Huygens Probe.

After Cassini's mission ends, Webb will begin operations, providing an excellent platform for continuing studies of Titan with its unique new capabilities.

“On our journey to Mars, we are closer than ever before to sending American astronauts to our neighbouring Red Planet,” Green noted.

The next Mars rover scheduled for launch in 2020 is under construction and NASA’s InSight Mission to study the interior of the Red Planet is scheduled to launch in 2018.​

​New York, July 18 (IANS) The specialised nerve cells in our brain that are responsible for emotional memory also play an important role in fear learning, say researchers.

The team from Mount Sinai Health System in New York City set out to identify the synaptic connections between brain's inhibitory cells called parvalbumin-interneurons (PV-INs), sensory pathways and neighbouring principal neurons in a brain region involved in detecting and responding to dangerous situations.

They found that the sparse but potent population of PV-INs in the amygdala region of the brain influence fear memory encoding -- the process responsible for persistent reactions to trauma-associated cues.

Stimuli encountered during a traumatic event can elicit strong emotional reactions long after the threat has subsided. 

These emotional memories are thought to be encoded through changes in the neural connections or synapses, within the basolateral amygdala that provide outputs to other brain areas, controlling the so-called "fight or flight" response. 

"Our study is the first to show that this default silencing may, in part, be attributable to a sparse population of inhibitory PV-INs," said Roger Clem from Mount Sinai. 

"The complex anatomy of these cells may allow them to function like master regulators on a hair trigger, springing into action to suppress their neighbours when they detect even the slightest sensory perturbation," Clem added.

To investigate whether fear learning alters PV-IN properties and their silencing effect on surrounding neurons, the researchers introduced fear conditioning in a mouse model, pairing an auditory tone with a subsequent aversive foot shock. 

They found that when animals acquire a fear memory, the suppressive influence of PV-INs is relieved, allowing the fear system to respond more vigorously during a "fight-or-flight" response.

The study was published recently in the journal Neuron.​

New York, July 20 (IANS) The key element in our decision-making that serves to both gauging errors and revising our approach is confidence, suggested a new study.

The study, published in the journal Proceedings of the National Academy of Sciences, offers insights into the hierarchical nature of how we make choices over extended periods of time, ranging from medical diagnoses and treatment to the strategies we use to invest our money.

"Overall, we found that the brain uses confidence to gauge errors and revise decision strategy. Specifically, the confidence in our initial assessments influences how we revisit them," said Roozbeh Kiani, Assistant Professor, New York University.

The research was to not only understand simple decisions about information immediately available to us but also to capture decisions about the strategies that guide multiple decisions over time.

"What is challenging about comprehending, why we make certain choices over long periods is to determine the true causes of the outcomes of our decisions," explains Braden Purcell, researcher, New York University.

To do so, the researchers devised an experiment in which subjects judged the net motion direction of multiple dots on a computer screen. The subjects' judgments were recorded by gauging their eye movement toward one of several targets on the screen.

Researchers discovered that when confident about motion direction, subjects attributed negative feedbacks to a change in the environment and quickly explored new targets.

When the subjects were less confident, they counted negative feedbacks as partial evidence for an environment change but withheld exploring a new target until the sum of evidence which is confidence on error trials -- reached a threshold, revealed the study.

According to the researchers, optimal decision-makers should adjust the threshold for switching strategy based on the volatility of the environment -- lower thresholds for environments that change more often.

They tested this possibility and showed that subjects were quicker to explore new targets when changes in the environment happened more frequently

London, July 18 (IANS) Children as young as nine months-old prefer to play with toys specific to their own gender -- boys with cars or balls and girls with dolls or cooking pots, says a new study.

The study, published in the journal of Infant and Child Development, showed that in a familiar nursery environment significant sex differences were evident at an earlier age than gendered identity is usually demonstrated.

“We found that, in general, boys played with male-typed toys more than female-typed toys and girls played with female-typed toys more than male-typed toys,” Brenda Todd, Senior Lecturer in Psychology at City University London.

To investigate the gender preferences seen with toys, the researchers observed the toy preferences of boys and girls engaged in independent play nurseries in Britain, without the presence of a parent. 

The toys used in the study were a doll, a pink teddy bear and a cooking pot for girls, while for boys a car, a blue teddy, a digger and a ball were used.

The 101 boys and girls fell into three age groups: nine to 17 months, when infants can first demonstrate toy preferences in independent play; 18 to 23 months, when critical advances in gender knowledge occur; and 24 to 32 months, when knowledge becomes further established.

Stereotypical toy preferences were found for boys and girls in each of the age groups, demonstrating that sex differences in toy preference appear early in development. 

Both boys and girls showed a trend for an increasing preference with age for toys stereotyped for boys.

"Our results show that there are significant sex differences across all three age groups, with the finding that children in the youngest group, who were aged between nine-17months when infants are able to crawl or walk and therefore make independent selections, being particularly interesting; the ball was a favourite choice for the youngest boys and the youngest girls favoured the cooking pot," Todd noted.

"Sex differences in play and toy choice are of interest in relation to child care, educational practice and developmental theory,” she pointed out.​