(Current Affairs) Science & Technology, Defence, Environment | October : 2017

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::Science & Technology, Defense, Environment::

Rotavirus vaccine of Serum Institute’s found to be effective on children

  • A rotavirus vaccine tested on children during a Phase III trial has been found to be safe and efficacious.
  • The vaccine (ROTASIL) manufactured by the Pune-based Serum Institute of India has nearly 39% efficacy in children with severe rotavirus cases and nearly 55% against the very severe form of rotavirus diarrhoea.
  • The vaccine targets all the five rotavirus serotypes.
  • In 2013, an estimated 47,000 rotavirus deaths occurred in India. India accounted for 22% of all rotavirus deaths in the world.
  • The Phase III trial was carried out at six sites in India.
  • Three doses of the vaccine were given at 6, 10, and 14 weeks of age to 3,749 infants, while another group of 3,751 children was given a dummy.
  • Children were randomly assigned to receive either the vaccine or the dummy and neither the children and their parents nor those involved in vaccinating the children were aware who was receiving the vaccine and who was receiving the dummy.
  • The trial followed the vaccinated children till they turned two to study the safety of the vaccine. The results were published in the journal Vaccine .
  • The three doses of the vaccine were given at 6, 10, and 14 weeks to coincide with the routine vaccination under India’s universal immunisationprogramme.
  • The vaccine used is a mixture (reassortment) of bovine and human rotavirus
  • “The bovine serotype does not cause diarrhoea in children. But as the bovine serotype carried the human antigen (gene) it helps the human body to develop antibodies against all the five human rotavirus serotypes,” says Dr. Prasad S. Kulkarni, Medical Director at Serum Institute, Pune.\
    Bharat Biotech launched a human rotavirus vaccine in 2015.
  • The international NGO PATH partnered with Serum Institute on evaluating the vaccine in the Phase III trial.

First lunar space station

  • Russia and the United States agreed to cooperate on a NASA-led project to build the first lunar space station, part of a long-term project to send humans to Mars.
  • The project envisages building a crew-tended spaceport in lunar orbit that would serve as a “gateway to deep space and the lunar surface”
  • The Russian space agency Roscosmos and NASA said they had signed a cooperation agreement at an astronautical congress in Adelaide.
  • NASA said the agreement reflected the two agencies’ common vision for space exploration.

Ten scientists win laurels

  • Ten scientists were announced winners of the annual Shanti Swarup Bhatnagar Prize at a function presided over by President Ram Nath Kovind.
  • The winners this year for the Biological Sciences are Deepak Nair at the Regional Centre for Biotechnology, Faridabad, and Sanjeev Das, National Institute of Immunology, Delhi; Chemical Sciences, Naresh Patwari, Indian Institute of Technology Bombay; Earth Sciences, Suresh Babu, VSSC, Thiruvanantha-puram; Engineering Services, Aloke Paul and Neelesh Mehta, Indian Institute of Science, Bengaluru.

Nerve stimulation pulls patient out of 15-year vegetative state

  • Researchers say that a nerve stimulation technique may have raised the level of consciousness in a 35-year-old man who has been in a vegetative state for years.
  • The report in the U.S. journal Current Biology is based on just one patient, but researchers say they plan to expand their work to others because of the improvements they have seen in the man, who was incapacitated by a car accident 15 years ago.
  • The process involves using a chest implant to send pulses of electricity to the vagus nerve, which connects the brain to other major organs of the body. Vagus nerve stimulation is already used to treat people with epilepsy and depression.
  • The man showed significant improvements in attention, movement and brain activity after one month of vagal nerve stimulation, according to the report.
  • He began responding to simple orders, such as following an object with his eyes and turning his head on request. He also appeared more alert and was able to stay awake when listening to his therapist read a book.
  • He was classified as having moved from a vegetative state to a “state of minimal consciousness”, according to brain scans that showed improvements in areas of the brain involved in movement, sensation and awareness.
  • This means consciousness remains severely altered but, in contrast to the vegetative state, there is minimal but definite behavioural evidence of self or environmental awareness.
  • The patient was scored on a scale of 0 to 23, where 0 represents no real verbal, visual or motor response and 23 indicates good ability. Before any stimulation, the patient scored 6/23 and at the end of the study, when the patient was on the maximum stimulation, he scored 8/23 on the functional scale.

Organic waste as a substitute for petroleum

Scientists have developed a way to extract sugars from wood chips and organic forest waste, which may serve as a cheaper substitute for petroleum a raw material for fuel.

The key to the technology is the use of a concentrated solution of an inorganic salt in the presence of a small amount of mineral acid, researchers said.

The team integrated the process with another step, which converts the sugars to furans and enables the salt solution to be recycled. Furans are compounds used to make speciality chemicals.

Cement material that is eco friendly being tested for use in industry

  • A research collaboration between India and Switzerland on a new cement material that can reduce carbon dioxide emissions in the manufacturing process is set to take off into implementation.
  • The construction sector is a major contributor to global carbon dioxide emissions. Though this is known, it appears difficult to reduce the scale of construction, especially as it is a route to establishing more equitable conditions in developing countries like India. One way of mitigating the emissions factor is the use of Limestone Calcined Clay Cement or the LC3 technology.
  • Traditional processes that manufacture cement from clinker-limestone or clinker-calcined clay combinations are well known. LC3 effects a synergy between these processes.
  • The combination of the new method and the material properties effectively reduces carbon dioxide emissions by 30% as compared to the traditional way of manufacturing cement.
  • Research on this evolved over ten years in Karen Scrivener’s lab at the Swiss Federal Institute of Technology (EPFL) at Lausanne, in Switzerland. Partners in this research are IIT Delhi, IIT Madras and TARA (Technology and Action for Rural Development).
  • In manufacturing portland cement, limestone and materials like clay are heated together in huge kilns to high temperatures (approximately 1,450 degrees C), so that they fuse without melting to give clinker.
  • This is the most CO2-intensive part of the whole process. The carbon dioxide comes both from the burning of the fuel needed to create that temperature and due to the breakdown of limestone into calcium oxide and carbon dioxide. The latter part accounts for 60% of the CO2 emissions in manufacture of cement.
  • The best thing to do would be to substitute CO2-intensive clinker with a different material.
  • In India, fly ash a waste produced in the burning of coal for producing energy is used in the manufacture of blended cement. However this is used in a lower proportions and only where available; therefore, for effectively reducing emissions, more clinker is to be substituted with calcined clay and limestone. This reduces emissions by 30% with respect to portland cement.

Skin bacterium with antimicrobial activity discovered

  • Bacteria found on the skin are known to harbour a large repertoire of antimicrobial agents. A new bacterial strain of Staphylococcus capitis identified by scientists at Delhi’s CSIR-Institute of Genomics and Integrative
  • Biology (CSIR-IGIB) has a strong antibacterial activity against Gram-positive bacteria, including Staphylococcus aureus.
  • The work reconfirms the growing understanding that bacteria found on the skin may be a “rich source” of novel antimicrobial molecules. The results of the study were published in the journal Scientific Reports.
  • The bacteria were isolated from the skin surface of a healthy human foot; the bacteria are specifically found near the toes. Different bacteria are found in different niches of the skin. For instance, bacteria found in the arm pit are different from those found on the feet.
  • The antimicrobial activity helps the bacteria to secure their niche environment by preventing other bacteria, including pathogenic bacteria, from colonising.
  • The new bacterial strain identified are closely related and can thrive in the same niche on the skin. And this drives the competition between the two bacteria.
  • Staphylococci are common colonisers of human skin and the third largest genera identi?ed in human skin microbiome.
  • In all, the new strain of bacteria has nine antimicrobial peptides, of which two (epidermicin and gallidermin) have already been characterised from other bacteria. The other seven new peptides have been found to have antimicrobial activity.
  • To be absolutely certain about the antimicrobial activity that we see is from the peptides and not from any other biological material as a result of contamination, we tested the seven purified synthetic peptides against a set of select microbes. It was a qualitative test.
  • Synthetic peptides with sequences identical to the natural ones isolated from the bacteria were synthesised by the team. The synthetic peptides were found to possess antibacterial activity, opening the window to developing new antimicrobial compounds.
  • Since the purified synthetic peptides are inhibitory, it not only confirms the antimicrobial activity but also shows that the synthetic peptides can be used directly without actually culturing the microbes.
  • The researchers would next study the minimum inhibitory concentration (the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism) required by the peptides and test it against more species of Gram-positive bacteria and specifically against drug-resistant S. aureus.
  • Besides isolating the peptides responsible for antimicrobial activity, the researchers have identified the genes responsible for other functions such as adhesion, acid stress tolerance, colonisation and survival on human skin.
  • The team has been isolating bacteria from the skin and studying their roles. The researchers had earlier reported another bacteria from human skin with antimicrobial activity. And in a paper published in May this year, they reported the discovery of a new Gram-positive bacterial genus — Auricoccus indicus. The bacteria were isolated from the external ear lobe of a healthy individual.

Does total darkness or light alter the body clock?

  • Will living in complete darkness or being in light for 24 hours for the rest of our lives affect our circadian rhythm (sleep–wake cycles)? Probably not, at least in the case of fruit flies.
  • Experiments carried out on 330 generations of drosophila (fruit flies) confirmed that circadian rhythm was persistent in flies that were kept in complete darkness or complete light 24 hours a day for over 19 years. This may be due to the intrinsic value of the body’s time-keeping system in coordinating our internal physiological functions.
  • This was the finding of a study by a group of scientists led by Prof. Vijay Kumar Sharma at the Chronobiology Lab (where study of the biological clock is carried out) at Jawaharlal Nehru Centre for Advanced Scientific
  • Research (JNCASR), Bengaluru; Prof. Sharma passed away last year after the completion of the work.
  • Using drosophila activity monitors, locomotor activity patterns of flies kept in the three different conditions (total darkness, total light, and normal day–night conditions) were monitored.
  • Interestingly, the flies maintained in complete darkness exhibited a relatively better sleep–wake cycle than the ones in complete light. The control group had cues of day and night in the form of 12 hours of light and 12 hours of darkness, while the flies in the other two groups which were not exposed to such cues also maintained circadian rhythms over several hundred generations.
  • The results of the study help dispel the notion that continuous darkness may regress the body’s biological clock and show that absence of light may have caused the evolution of a more robust clock in flies. The results were recently published in Chronobiology International.
  • The time at which flies emerge as adults from pupae and the time when adult females laid eggs were examined, since appropriate timing of adult emergence and oviposition (egg-laying) behaviours are thought to be important for survival and reproduction.
  • For the experiment, a few flies taken from the group kept in complete darkness and complete light were exposed to normal cycle of 12 hours of light and 12 hours of darkness. They found that flies which were taken from the group exposed to complete light tend to lay eggs at the time of dusk when exposed to normal light and darkness cycle. On the other hand, flies taken from the group exposed to complete darkness tend to lay eggs at about noon.
  • In nature, a high temperature during the day may increase the risk of drying of eggs, which may be the reason why egg-laying mostly takes place in the evenings. Since the flies in complete darkness have not been exposed to light for several generations they may have slowly lost this ability of restricting egg-laying to the evenings.
  • The most interesting find of the study was that the circadian rhythm did not degenerate over 19 years. Complete regression of the circadian clock is very unlikely because of the several other functions of the core circadian genes.

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