كلية الأفق الجامعية
كلية الأفق الجامعية

Knowledge Update

How highly potent antibody neutralises Zika discovered

New York, Nov 25 (IANS) Taking a step further in identifying a possible therapy for the Zika infection, researchers have discovered the mechanism by which a human antibody previously identified to react with the Dengue virus, prevents Zika infection at a cellular level.

Previously, the antibody C10 was identified as one of the most potent antibodies able to neutralise Zika infection. The new study, published in the journal Nature Communications, determines how C10 prevents the infection.

"By defining the structural basis for neutralization, these studies provide further support for the idea that this antibody will protect against Zika infection, potentially leading to a new therapy to treat this dreaded disease," said Ralph Baric, Professor at University of North Carolina.

To infect a cell, virus particles usually undergo two main steps, docking and fusion, which are also common targets for disruption when developing viral therapeutics. 

During docking, the virus particle identifies specific sites on the cell and binds to them. With Zika infection, docking then initiates the cell to take the virus in via an endosome -- a separate compartment within the cell body. 

Proteins within the virus coat undergo structural changes to fuse with the membrane of the endosome, thereby releasing the virus genome into the cell, and completing the fusion step of infection.

Using a method called cryoelectron microscopy, which allows for the visualisation of extremely small particles and their interactions, the team visualised C10 interacting with the Zika virus under different pHs (potential of hydrogen, a scale of acidity), so as to mimic the different environments both the antibody and virus will find themselves in throughout infection. 

They showed that C10 binds to the main protein that makes up the Zika virus coat, regardless of pH, and locks these proteins into place, preventing the structural changes required for the fusion step of infection. 

Without fusion of the virus to the endosome, viral DNA is prevented from entering the cell, and infection is thwarted.

"Hopefully, these results will further accelerate the development of C10 as a Zika therapy to combat its effects of microcephaly (a birth defect) and Guillain-Barre (paralysis) syndrome," one of the researchers Lok Shee-Mei from Duke-National University of Singapore Medical School in Singapore.

This skin patch does more than monitor sweat

New York, Nov 24 (IANS) Researchers have developed a first-of-its-kind soft, flexible microfluidic device that easily adheres to the skin and connects wirelessly with a smartphone to measure the wearer's sweat to show how his or her body is responding to exercise.

Sweat is a rich, chemical broth containing a number of important chemical compounds with physiological health information, the researchers said.

The low-cost device, which is a little larger than a quarter and nearly the same thickness, connects wirelessly with a smartphone to analyse key biomarkers to help a person to find whether he/she needs to drink more water or energy drink to boost the electrolyte levels, or if something is medically going wrong in his/her body.

"The intimate skin interface created by this wearable, skin-like microfluidic system enables new measurement capabilities not possible with the kinds of absorbent pads and sponges currently used in sweat collection," said John A. Rogers, Professor at the Northwestern University, US.

For the study, published in the journal Science Translational Medicine, the team tested the device on two groups of cyclists. 

The device, which is designed for one-time use for a few hours, was placed directly on the skin of the forearm or back of the athletes.

It showed accurate accounts of the acidity of sweat and concentrations of glucose, chloride and lactate and could even detect the presence of a biomarker for cystic fibrosis.

To get the data, individuals had to use a smartphone to capture the photo of the device. An app then analyses that photo to display the relevant information.

"The sweat analysis platform we developed will allow people to monitor their health on the spot without the need for a blood sampling and with integrated electronics that do not require a battery but still enable wireless connection to a smartphone," said Yonggang Huang, Professor at the Northwestern University, US.

In the future, it may be more broadly used for disease diagnosis, the researchers added.

New drug to suppress allergies, asthma

Melbourne, Nov 25 (IANS) An Australian Nobel Prize-winning scientist is developing a drug to counter allergies and asthma, a statement said on Friday.

Still in its initial stage the the drug can be taken as tablets, capsules, liquids or powder, Xinhua news reported. 

Barry Marshall, a microbiology professor from University of Western Australia, who won the Nobel Prize in Physiology in 2005 for stomach ulcer research, is working on the new drug.

The medication, named Immbalance, aims to suppress an overactive immune system.

"This actually arose from work we were doing on helicobacter, the stomach bug, for which Robin Warren and I won the Nobel Prize a few years ago," Marshall said on Friday.

"We've discovered the way it survives in your body is by suppressing the immune system so you can't get rid of it.

"I can't guarantee that it's going to cure allergy sufferers... we think this kind of thing will bring people who are hyper reactive... down into the normal range."

Marshall, who spent the last seven years developing the drug, said that it can be formulated as tablets, capsules, liquids or powder.

"Children could spread the powder on their cereal or put it in a drink and over the course of a few months could suppress their allergic response," he said in a UWA media release.

"We think it's going to be 100 percent safe. It won't remove your immune system; it will just take the edge off."

Astronomers may have found Milky Way's faintest satellite galaxy

Washington, Nov 23 (IANS) Using a 8.2-meter telescope on the summit of Mauna Kea in Hawaii, an international team of researchers has found what could be the faintest dwarf satellite galaxy of our Milky Way.

Called Virgo I, the new dwarf satellite galaxy lies in the direction of the constellation Virgo at a distance of 280,000 light years from our Sun, Xinhua news agency reported.

It has an absolute luminosity of -0.8 in the optical waveband and such a remote galaxy with faint brightness has not been identified in previous sky surveys.

Its discovery suggested the presence of a large number of yet-undetected dwarf satellites in the halo of the Milky Way, according to the study published this week in The Astrophysical Journal.

"This discovery implies hundreds of faint dwarf satellites waiting to be discovered in the halo of the Milky Way," study leader Masashi Chiba, a professor from the Tohoku University in Japan, said in a statement.

"How many satellites are indeed there and what properties they have, will give us an important clue of understanding how the Milky Way formed and how dark matter contributed to it."

So far, some 50 satellite galaxies to the Milky Way have been identified.

Santa Claus fantasy may damage parent-child bond

London, Nov 24 (IANS) With the onset of Christmas season, millions of parents will lie to their children about the existence of Santa Claus or Christmas Father. A new study has suggested that this lie may damage their bond.

The study, published in Lancet Psychiatry, showed that the children's trust in their parents may be undermined by the Santa lie.

"The morality of making children believe in such myths has to be questioned. All children will eventually find out they've been consistently lied to for years, and this might make them wonder what other lies they've been told," asked Christopher Boyle, Professor at the University of Exeter in Britain.

But, according to the authors, the Christmas father fantasy may not be purely for the children.

Parents may not be motivated by purely creating magic for their children, but by a desire to return to the joy of childhood themselves.

For adults, it's a chance to go back to a time when they believed in magic.

"Many people may yearn for a time when imagination was accepted and encouraged, which may not be the case in adult life," Boyle said.

"The persistence of fandom in stories like Harry Potter, Star Wars and Doctor Who well into adulthood demonstrates this desire to briefly re-enter childhood," added Kathy McKay from the University of New England, Australia. 

However, the study contended that lying to children may sometimes be right.

"An adult comforting a child and telling them that their recently deceased pet will go to a special place (animal heaven) is arguably nicer than telling graphic truths about its imminent re-entry into the carbon cycle," Boyle observed.

Rare genetic variations linked to schizophrenia found

New York, Nov 23 (IANS) In the largest study of its kind, researchers have discovered rare genetic variations linked to schizophrenia, a severe mental disorder that often includes psychotic experiences, such as delusions or hearing voices that are not there.

The Psychiatric Genomics Consortium, an international team led by Jonathan Sebat from the University of California San Diego School of Medicine in the US analysed the genomes of more than 41,000 people.

Their study, published in the journal Nature Genetics, revealed several regions of the genome where mutations increase schizophrenia risk between four- and 60-fold.

These mutations, known as copy number variants, are deletions or duplications of the DNA sequence. 

A copy number variant may affect dozens of genes, or it can disrupt or duplicate a single gene. 

"This type of variation can cause significant alterations to the genome and lead to psychiatric disorders," said Sebat.

Analysing the genomes of 21,094 people with schizophrenia and 20,227 people without schizophrenia, the team of more than 260 researchers found eight locations in the genome with copy number variants associated with schizophrenia risk. 

The researchers also found that these copy number variants occurred more frequently in genes involved in the function of synapses, the connections between brain cells that transmit chemical messages.

"We're confident that applying this same approach to a lot of new data will help us discover additional genomic variations and identify specific genes that play a role in schizophrenia and other psychiatric conditions," Sebat said.

Study sheds light on genetic makeup of river blindness parasite

Washington, Nov 23 (IANS) Aiming to understanding why the roundworm that causes river blindness has started developing resistance to the drug used as the first-line treatment for the disease, a new study sheds light on the genetic makeup of the parasite.

The drug ivermectin remains the first-line treatment to target the parasite. The drug's discoverers were honoured with the Nobel Prize in Physiology or Medicine just last year.

But after several decades of exposure to ivermectin, these parasites are beginning to show resistance.

"We want to understand the origin of this resistance," said senior study author Makedonka Mitreva, Associate Professor of medicine at Washington University School of Medicine in St. Louis.

The parasite that causes river blindness infects about 37 million people in parts of Africa and Latin America, causing blindness and other major eye and skin diseases in about five million of them. 

The parasite is a roundworm called Onchocerca volvulus and is carried by black flies that thrive near rivers and streams. 

"Are these parasites evolving to survive the treatment, or are the surviving worms actually new strains that have been introduced due to migration of the black flies or of the parasite itself?" Mitreva asked.

To find out, Mitreva and her colleagues studied samples of the roundworms that have been stored since the early 1990s, before large-scale ivermectin treatment programmes began. 

They also are sequencing present-day strains for comparison. The current study, published in the journal Nature Microbiology, reports data only from the historical samples.

"We worked hard to find samples of the parasite that had not been exposed to the drug because we needed to establish an ancestral baseline," Mitreva said. 

The new study included 27 roundworm samples taken in the early 1990s from four distinct regions -- West African forest, West African savanna, Uganda and Ecuador.

"In West Africa, there are two separate strains of this parasite based on geographic areas -- the savanna strain and the forest strain," Mitreva said.

"The severity of the disease caused by each strain is very different. The savanna strains are much more virulent and have been associated with higher rates of blindness. The forest strains cause a mild skin disease. That's why we wanted to see how they differ genetically," she added.

According to Mitreva, the Uganda strains, collected in central Africa, could not be classified as either the forest or savanna strain. Similarly, the strains from Ecuador, in South America, were also very different from the African strains.

In general, Mitreva said, large-scale control efforts -- including mass treatment with ivermectin and the use of insecticides to reduce black fly populations -- have been very effective over the past 30 years. 

But since pockets of drug resistance are showing up, she said studies such as this one are important if the World Health Organisation's goal of eliminating the parasite by 2025 is to be met

NASA selects SpaceX for launch of global surface water survey probe

Washington, Nov 23 (IANS) NASA has selected SpaceX to provide launch services for the agencys April 2021 mission designed to make the first-ever global survey of Earths surface water.

The mission is likely to be launched on a SpaceX Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Air Force Base in California.

The total cost for NASA to launch the Surface Water and Ocean Topography (SWOT) mission is approximately $112 million, which includes the launch service; spacecraft processing; payload integration; and tracking, data and telemetry support, the US space agency said on Wednesday.

Designed to make the first-ever global survey of Earth's surface water, in addition to high-resolution ocean measurements, the SWOT mission will collect detailed measurements of how water bodies on Earth change over time.

The satellite will survey at least 90 per cent of the globe, studying Earth's lakes, rivers, reservoirs and oceans, at least twice every 21 days, aid in freshwater management around the world, to improve ocean circulation models and weather and climate predictions. 

The SWOT spacecraft will be jointly developed and managed by NASA and the French space agency Centre National d'Etudes Spatiales (CNES).

NASA said its launch services programme at Kennedy Space Center in Florida will manage the SpaceX launch service. 

SpaceX currently has nine NASA missions on its planned launch manifest for upcoming contracts, but it still hasn't provided a definite date for resuming launches following the explosion of a SpaceX rocket during pre-flight checks on a launch pad in September, Techcrunch.com reported.

SpaceX's Falcon 9 rocket exploded on September 1 at Cape Canaveral, Florida during a pre-launch test, destroying the rocket itself and a $200-million communications satellite that was set to play a key role in Facebook's plans to provide internet access to remote villages in Africa. No one was injured in the explosion.

In a series of tweets in September, SpaceX CEO Elon Musk termed the launch pad accident as the "the most difficult and complex failure" in the company's 14-year history.

Global carbon emissions remain flat for third year

London, Nov 14 (IANS) Global carbon emissions from burning fossil fuels are projected to rise only slightly in 2016, marking three years of almost no growth, says a study.

The researchers said that carbon emissions did not grow last year and the projected rise of only 0.2 per cent for 2016 marks a clear break from the rapid emissions growth of 2.3 per cent per year in the decade to 2013, with just 0.7 per cent growth seen in 2014.

The study, published in the journal Earth System Science Data, however, pointed out that although the break in emissions rise ties in with the pledges by countries to decrease emissions until 2030, it falls short of the reductions needed to limit climate change well below two degrees Celsius.

"This third year of almost no growth in emissions is unprecedented at a time of strong economic growth. This is a great help for tackling climate change but it is not enough. Global emissions now need to decrease rapidly, not just stop growing," Corinne Le Quere, Professor at University of East Anglia (UEA) in Britain who led the data analysis, said.

The analysis by researchers at the University of East Anglia and the Global Carbon Project, a group of scientists who measure how much carbon dioxide (CO2) humans emit every year, and how much is subsequently absorbed by plants, land surfaces and oceans, showed emissions growth remained below one per cent despite GDP growth exceeding three per cent.

The researchers identified decreased use of coal in China and the US as the main reason behind the three-year slowdown.

China - the biggest emitter of CO2 at 29 per cent - saw emissions decrease by 0.7 per cent in 2015, compared to growth of more than five per cent per year the previous decade. 

The scientists have projected a further reduction of 0.5 per cent is projected for 2016.

The US, the second biggest emitter of CO2 at 15 per cent, also reduced its coal use while increasing its oil and gas consumption and saw emissions decrease 2.6 per cent last year.

US emissions are projected to decrease by 1.7 per cent in 2016.

The European Union's 28 member states are the third largest emitter causing 10 per cent of emissions. The EU's CO2 emissions went up 1.4 percent in 2015, in contrast with longer term decreases.

India contributed 6.3 per cent of all global CO2 emissions in 2015, the study said.

The Global Carbon Budget analysis showed that, in spite of a lack of growth in emissions, the growth in atmospheric CO2 concentration was a record-high in 2015, and could be a record again in 2016 due to weak carbon sinks.

"Part of the CO2 emissions are absorbed by the ocean and by trees. With temperatures soaring in 2015 and 2016, less CO2 was absorbed by trees because of the hot and dry conditions related to the El Niño event. Atmospheric CO2 levels have exceeded 400 parts per million (ppm) and will continue to rise and cause the planet to warm until emissions are cut down to near zero," Le Quere said.

Researchers find 'sweet' solution to purify contaminated water

Toronto, Nov 15 (IANS) Indian-origin researchers at York University in Toronto have developed a solution for water treatment that uses only naturally available antimicrobial substances and sugar.

The paper strip solution called "DipTreat" is laced with sugar to kill E. coli bacteria in contaminated water.

"We were able to efficiently remove almost 90 per cent of bacteria by dipping the special paper strip, DipTreat, in contaminated water samples," said one of the researchers Sushanta Mitra.

The discovery will be key to developing a new generation of inexpensive and portable water treatment devices, with human health benefits around the world - from the far north of Canada to the remote villages of India, Mitra said.

"Now with DipTreat, we have learned it will take less than two hours to fish, trap and kill E. coli in water," Mitra, Professor at York University's Lassonde School of Engineering.

While using porous paper strips to trap the bacterial cells, for killing, the researchers used an antimicrobial agent extracted from the seeds of moringa -- commonly known as drumstick or horseradish tree. 

As a result, the DipTreat solution for water treatment uses only naturally available antimicrobial substances and sugar, with minimal environmental and health impact. 

Currently, popular water treatment systems use silver nanoparticles and clays, whose long term impact on human health is yet to be fully understood, according Mitra. 

So far, DipTreat is effective for small quantities of water. For example, someone who is hiking can collect a glass of water and then dip the paper strips to purify it before drinking. 

The researchers believe that the invention could lead to a much greater impact. 

Published in the journal Environmental Science Water Research & Technology, the study is co-authored by Mitra, Saumyadeb Dasgupta and Naga Siva Gunda.