Knowledge Update

London, Dec 25 (IANS) Using ultrafast imaging of moving energy, scientists have determined the speed of photosynthesis.

The study said the imaging could help scientists better understand the process and how it could be copied for producing fuels.

Earlier, it was believed that the process of charge separation in the reaction was the slowest step in the process. But scientists have shown that the slowest step is in fact the process through which the plants harvest light and transfer its energy through the antennae to the reaction centre.

"We can now see how nature has optimised the physics of converting light energy to fuel, and can probe this process using our new technique of ultrafast crystal measurements," said Jasper van Thor from Imperial College, London.

"For example, is it important that the bottleneck occurs at this stage, in order to preserve overall efficiency? Can we mimic it or tune it to make artificial photosynthesis more efficient? These questions, and many others, can now be explored," Thor added.

Scientists used lasers to cause reactions in crystals of Photosystem II -- enzyme that uses the light energy to split water into oxygen and hydrogen -- and then measured in space and time the movement of excitations of electrons.

"The resulting movie of the movement of excited electrons across minute sections of the system revealed where energy is held and when it is passed along," the study noted.

The study was published in the journal Nature Communications.

​New York, Dec 25 (IANS) US researchers claim to have found the risk factors associated with adults having mental illness becoming victims or perpetrators of violence.

Previous study found that almost one-third of adults with mental illness were likely to be victims of violence within a six-month period.

The study found that factors such as homelessness, in-patient mental-health treatment, psychological symptoms of mental illness, substance use and as victims or perpetrators of violence are both indicators and outcomes -- that is, they can act as both causes and effects.

"We found that all of these indicators mattered, but often in different ways," said Sarah Desmarais, Associate Professor at North Carolina State University in the US.

"For example, drug use was a leading indicator of committing violence, while alcohol use was a leading indicator of being a victim of violence," Desmarais added.

However, the researchers also found that affective symptoms -- category of psychological symptoms -- were also closely associated with violence.

"By affect, we mean symptoms including anxiety, depressive symptoms and poor impulse control. The more pronounced affective symptoms were, the more likely someone was to both commit violence and be a victim of violence," Desmarais noted.

The study highlights the importance of interventions to treat mental-health problems in order to reduce community violence and instances of mental-health crises.

"By treating people who are exhibiting these symptoms, we could reduce violence. Just treating drug or alcohol use - which is what happens in many cases - isn't enough. We need to treat the underlying mental illness that is associated with these affective symptoms," Desmarais said, in the paper appearing in the journal Psychological Medicine.

New York, Dec 25 (IANS) Driverless cars can save fuel if they trail each other in large platoons, as they will experience less aerodynamic drag when they drive close together, researchers have found.

But formation of a vehicle platoon could be time consuming.

The study by the researchers at Massachusetts Institute of Technology (MIT) that was recently presented at the International Workshop on the Algorithmic Foundations of Robotics suggested that relatively simple, straightforward schedules may be the optimal approach for saving fuel and minimising delays for autonomous vehicle fleets.

The findings may also apply to conventional long-distance trucking and even ride-sharing services.

"Ride-sharing and truck platooning and even flocking birds and formation flight, are similar problems from a systems point of view," said Sertac Karaman, Associate Professor at MIT.

"People who study these systems only look at efficiency metrics like delay and throughput. We look at those same metrics, versus sustainability such as cost, energy, and environmental impact. This line of research might really turn transportation on its head," Karaman added.

The research noted that for truck-driving -- particularly over long distances -- most of a truck's fuel is spent on trying to overcome aerodynamic drag, that is, to push the truck through the surrounding air.

"Scientists have previously calculated that if several trucks were to drive just a few metres apart, one behind the other, those in the middle should experience less drag, saving fuel by as much as 20 per cent, while the last truck should save 15 per cent -- slightly less, due to air currents that drag behind," the study found.

As the number of vehicles are increased in the platoon, more energy can be collectively saved but it may cost in terms of time it takes to form a platoon.

The study found that the simplest policies resulted in least delays in platoon formation while saving most fuel.

"Time tables set to deploy platoons at regular intervals were more sustainable and efficient than those that deployed at more staggered times," the study mentioned.

​London, Dec 25 (IANS) British researchers have discovered a new genetic disease which results in neuro-degeneration and help find treatments for brain ageing conditions, such as Alzheimer's, Huntington's and Parkinson's.

The study revealed that the disease -- ataxia oculomotor apraxia type XRCC1 -- is caused by a genetic mutation that disrupts the repair of our DNA.

The study showed that when single strands of our DNA are damaged, a genetic mutation in a gene called XRCC1 causes a vital DNA-repairing enzyme (known as PARP1) in our bodies to over-activate.

In people suffering from the new disease, the speeding up of this key enzyme actually triggers the death of brain cells, the researchers said.

"Discovering this new disease and its cause is a huge step towards developing drug-based therapies for other rare neurodegenerative conditions," said lead author Keith Caldecott, Professor at University of Sussex.

"Drugs which target this key DNA repairing enzyme in the right way, could prove vital for treating people suffering from diseases caused by the over-activation of this protein - it is now crucial we determine what diseases these are.

Single strand breaks are one of the most common types of DNA damage and the researchers believe it's possible the discovery of this new genetic disease could be important for scientists researching other rare DNA repair related diseases.

The details appeared in the journal Nature.

​New York, Dec 25 (IANS) Researchers have identified a genetic immune disorder characterised by increased susceptibility and poor immune control of Epstein-Barr virus (EBV) and, in some cases, an EBV-associated cancer called Hodgkin's lymphoma.

The researchers studied two unrelated sets of siblings with similar immune problems and determined their symptoms were likely caused by a lack of CD70, a protein found on the surface of several types of immune cells.

Scientists at the US National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health (NIH), conducted the research with an international team of collaborators.

Both sets of siblings had evidence of uncontrolled infection with EBV, a common and usually mild virus, which resulted in the development of Hodgkin's lymphoma in three of these children.

Each child also had other immune symptoms, such as reduced activity of pathogen-fighting T cells, low production of antibodies and poor activation of antibody-producing B cells.

The researchers analysed the genomes of all four children and found that each had two mutated copies of the CD70 gene, resulting in nonfunctioning or nonexistent CD70 proteins.

All four parents, who had healthy immune systems, had only one copy of the mutation--indicating that CD70 deficiency follows an autosomal recessive pattern of inheritance.

This means affected individuals receive a flawed gene from each parent in order to have symptoms.

While no specific treatment for CD70 deficiency currently exists, each of the four children has recovered from Hodgkin's lymphoma and is receiving antibody infusions to help bolster the immune system, the researchers recently reported in the Journal of Experimental Medicine.

​London, Dec 25 (IANS) Using ultrafast imaging of moving energy, scientists have determined the speed of photosynthesis.

The study said the imaging could help scientists better understand the process and how it could be copied for producing fuels.

Earlier, it was believed that the process of charge separation in the reaction was the slowest step in the process. But scientists have shown that the slowest step is in fact the process through which the plants harvest light and transfer its energy through the antennae to the reaction centre.

"We can now see how nature has optimised the physics of converting light energy to fuel, and can probe this process using our new technique of ultrafast crystal measurements," said Jasper van Thor from Imperial College, London.

"For example, is it important that the bottleneck occurs at this stage, in order to preserve overall efficiency? Can we mimic it or tune it to make artificial photosynthesis more efficient? These questions, and many others, can now be explored," Thor added.

Scientists used lasers to cause reactions in crystals of Photosystem II -- enzyme that uses the light energy to split water into oxygen and hydrogen -- and then measured in space and time the movement of excitations of electrons.

"The resulting movie of the movement of excited electrons across minute sections of the system revealed where energy is held and when it is passed along," the study noted.

The study was published in the journal Nature Communications.

​New York, Dec 25 (IANS) When exposed to cancer treatment like chemotherapy and radiation, brain and heart tissues in very young children are more prone to apoptosis or programmed cell death, researchers said.

Apoptosis, in which molecular signals order cells to self-destruct, plays an important role in deciding the "fate" of a developing cell.

These toxic treatment stressors put young children at high risk for developing severe, long-lasting impairments in their brain, heart, the study said.

But active apoptosis in the early brain "also sets the stage for extremely high sensitivity to any type of damage or stress, especially that induced by radiation or chemotherapy," said lead author Kristopher A. Sarosiek, Assistant Professor at the Harvard T.H. Chan School of Public Health.

While some cancer cells die through apoptosis, some escape the death orders by activating "pro-survival" signals.

Anthony Letai from Dana-Farber Cancer Institute in Massachusetts, developed a test called BH3 profiling that can measure inside any cell the relative dominance of pro-survival or pro-death signals.

A cancer cell in which apoptotic death signals are dominant, is said to be "highly primed" or ready for self-destruction and therefore easily killed by therapy, while a cell with low priming is more resistant to death or damage.

Measuring the priming of cells in normal cells and tissues, the researchers found that in most normal adult tissues, including the brain and the heart, the machinery needed to perform apoptosis is nearly completely absent.

In contrast, this molecular machinery is abundant in newborn and very young rodents. As a result, brain and heart cells were therefore much more vulnerable to undergoing cell death when exposed to chemotherapy or radiation.

When tested in human cells, the youngest human brain cells were more highly primed with apoptotic machinery and vulnerable to chemotherapy and radiation damage.

Human brain and heart cells are most highly primed for apoptosis until four to six years of age, after which priming continues to be reduced, the researchers noted, in the paper appearing in the journal Cancer Cell.

New York, Dec 25 (IANS) Driverless cars can save fuel if they trail each other in large platoons, as they will experience less aerodynamic drag when they drive close together, researchers have found.

But formation of a vehicle platoon could be time consuming.

The study by the researchers at Massachusetts Institute of Technology (MIT) that was recently presented at the International Workshop on the Algorithmic Foundations of Robotics suggested that relatively simple, straightforward schedules may be the optimal approach for saving fuel and minimising delays for autonomous vehicle fleets.

The findings may also apply to conventional long-distance trucking and even ride-sharing services.

"Ride-sharing and truck platooning and even flocking birds and formation flight, are similar problems from a systems point of view," said Sertac Karaman, Associate Professor at MIT.

"People who study these systems only look at efficiency metrics like delay and throughput. We look at those same metrics, versus sustainability such as cost, energy, and environmental impact. This line of research might really turn transportation on its head," Karaman added.

The research noted that for truck-driving -- particularly over long distances -- most of a truck's fuel is spent on trying to overcome aerodynamic drag, that is, to push the truck through the surrounding air.

"Scientists have previously calculated that if several trucks were to drive just a few metres apart, one behind the other, those in the middle should experience less drag, saving fuel by as much as 20 per cent, while the last truck should save 15 per cent -- slightly less, due to air currents that drag behind," the study found.

As the number of vehicles are increased in the platoon, more energy can be collectively saved but it may cost in terms of time it takes to form a platoon.

The study found that the simplest policies resulted in least delays in platoon formation while saving most fuel.

"Time tables set to deploy platoons at regular intervals were more sustainable and efficient than those that deployed at more staggered times," the study mentioned.

​Brussels, Dec 24 (IANS) The European Union (EU) has provided 38.2 million euros ($39.8 million) in emergency funding to Italy to ease migratory pressure, an EU statement said.

​Beijing, Dec 24 (IANS) China began construction of its first high-speed railway network line under a private-public partnership, officials reported on Saturday.

The 269 km line will connect Hangzhou and Taizhou, in the eastern province of Zhejiang, among China's most prosperous provinces and one where the private sector is