Yellow Fever

The burden of yellow fever in any given area is known to be heavily dependent on climate, particularly rainfall and temperature which can impact both mosquito life cycle and viral replication. Now, researchers from Imperial College London and the World Health Organization (WHO) have developed a new model to quantify yellow fever dynamics across Africa using not only annual averages of these climatic measures but seasonal dynamics.

The new model integrated the effects of temperature on mosquito behavior and virus transmission and looked at monthly variation in temperature, rainfall, and vegetation throughout the year across Africa. The model confirmed and quantified that, even in areas with high transmission potential for yellow fever, the risk varies throughout the year.

This finding, in conjunction with forecasted data, could highlight areas of increased transmission and provide insights into the occurrence of large outbreaks. When used in conjunction with forecasted data, the model predictions could be useful for focusing both surveillance efforts, and the pre-positioning of material and equipment in areas and periods of, particularly high risk. This would allow the facilitation of early interventions in emerging yellow fever outbreaks — which is key to prevent large-scale outbreaks

Yellow fever is an acute viral hemorrhagic disease transmitted by the Aedes and Haemogogus mosquitoes. It is not always easy to diagnose, especially at the beginning, since its symptoms can often be confused with those of malaria, dengue fever, or other hemorrhagic fever. However, some patients will suffer from jaundice specific to the disease, which explains why the term “yellow” is used.

To date, there is no treatment for yellow fever. Water and medicines can be given to target the symptoms, such as fever or dehydration. Vaccination is the best option to prevent outbreaks of the disease and to protect people against it.

Other strategies to combat the disease include mosquito population control, with the large-scale use of pesticides and mosquito nets, as well as the treatment of stagnant water sources.

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Carnivorous plants use CO2 to lure prey

Scientists unravel another prey capture mechanism by pitcher plants
Carnivorous plants have been known to employ a variety of techniques like nectar, smell, colour and ultraviolet florescence to lure and capture prey. But now, scientists at the Jawaharlal Nehru Tropical Botanic Gardens and Research Institute here have come up with evidence that some carnivorous plants use carbon dioxide (CO2) to attract insects and ants to their prey traps.

A study conducted by the division of Phytochemistry and Pharmacology at the institute has found that the Indian pitcher plant (Nepenthes khasiana) uses the gas, both to attract prey and to aid the digestive process. The research team led by Sabulal Baby demonstrated that the unopened pitchers of the plant are carbon dioxide-enriched, with a gas concentration of 2,500 to 5,000 ppm (parts per million), approximately 10 times that in the earth’s atmosphere.

The open Nepenthes pitchers were found to emit CO2 constantly to attract insects. The study also detected high levels of CO2 dissolved in acidic pitcher fluids, ensuring optimum activities of the digestive enzymes. The findings have been reported in Scientific Reports, a journal published by Nature.

Carnivorous plants of the genus Nepenthes supplement their nutrient deficiency by capturing insects through their leaf-evolved pitchers which act as biological traps.

The study found that the high CO2 inside the pitchers was produced by the respiration of tissues within the cavity.

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Faster, cheaper urinary tract infection test

Urinary tract infection (UTI) is the second most common infectious disease that affects millions of people globally each year. The 48-hour wait for urine test report delays treatment, and inappropriate use of antibiotics make the problem even worse by giving rise to multidrug-resistant pathogens.

Now, researchers have developed a new test that can provide results in just 4 hours and also indicate which medicine should be prescribed for the infection. The diagnostic technique was developed by scientists at BITS-Pilani, Hyderabad campus, and published in BMJ Innovations.

The scientists visited hospitals in Punjab, Rajasthan and Telangana and collected urine samples from suspected UTI patients. The urine was filtered in a special filter to trap the pathogenic bacteria, and the bacteria was cultured in a specially designed growth media.

Antibiotic sensitivity strips

The strip contains 15 common antibiotics and helps in identifying the antibiotic sensitivity of the bacteria and deciding the most appropriate medicine to be used for the patient.

The new diagnostic technique has 93% sensitivity and 96% specificity. The researchers found that among the 426 tested samples, conventional microbiological method showed 243-positive and 183-negative whereas the new test showed 234-positive and 192-negative. There was very small fraction of false positive and false negatives reported. Further tests were carried out with more people.

The long delay in getting the test results often leads to wrong antibiotics being used. “Due to doctors prescribing broad spectrum antibiotics, the main agents of UTI [E. coli and K. pneumoniae] have developed antimicrobial resistance. These resistant bacteria not only cause long lasting infection but also reduce effectiveness of the available antibiotics. So our main aim was to develop a test which can minimise the irrational use of antibiotics,”

According to the scientists, the test does not require any other specialised equipment, dedicated space/lab or trained personnel. As the strip already has the panel of antibiotics, it is easier, faster and cheaper.

The team has already won several awards for the test. “The test is now undergoing multi-centric clinical validation in various labs and hospitals. We are waiting for the permission from CDSCO [Central Drugs Standard Control Organisation] to commercialise the test. It will probably hit the markets in three months,” adds Dr. Kapur.

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Scientists link new virus to kala-azar

Researchers have stumbled upon tantalizing evidence of an unknown virus that may be responsible for the persistence of kala-azar or visceral leishmaniasis, a parasite infection that has spawned epidemics and sickened thousands of Indians for over a century.

It’s still early to pointedly blame the virus but its discovery portends a new kind of treatment regime and may aid attempts to eradicate the disease.
Historically, the parasite Leishmania donovani is believed to be responsible for the dreaded infection. People get infected when bitten by an insect called the sandfly, which harbours the disease-causing parasite.

This month, a group of scientists from West Bengal and Uttar Pradesh said that another parasite may be involved. Another parasite called Leptomonas seymouri may also be present, according to Subhajit Biswas, one of the scientists involved in the study.

The researchers inferred this after they found the L seymouri and a virus called Lepsey NLV1 within it in 20 of 22 biological samples of patients who had a residual L donovani infection. They reported their findings in an online version of the peer-reviewed Archives of Virology.

Kala-azar is endemic to the Indian subcontinent in 119 districts in four countries (Bangladesh, Bhutan, India and Nepal). India itself accounts for half the global burden of the disease. If untreated, kala-azar can kill within two years of the onset of the ailment, though the availability of a range of drugs has meant that less than one in 1,000 now succumbs to the disease.

Kala Azar

It is also called Visceral Leishmaniasis, Black Fever and Dum Dum Fever. It is the most severe form of leishmaniasis and, without proper diagnosis and treatment, is associated with a high death rate.

Leishmaniasis is a disease caused by protozoan parasites of the Leishmania genus. The life cycle of Leishmania is completed in two hosts, humans and sandflies. The adult female sandfly is a bloodsucker, usually feeding at night on sleeping prey. The parasite migrates to the internal organs such as the liver, spleen (hence “visceral”), and bone marrow, and, if left untreated, will almost always result in the death of the host. Signs and symptoms include fever, weight loss, fatigue, anaemia and substantial swelling of the liver and spleen. Of particular concern, according to the World Health Organization (WHO), is the emerging problem of HIV/VL co-infection.

This disease is the second-largest parasitic killer in the world (after malaria), responsible for an estimated 200,000 to 400,000 infections each year worldwide.

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Embryo Transfer Technology

Embryo transfer technology (ETT) has revolutionised the breeding strategies in Bovines as a tool to optimise the genetic improvement in cattle.

Department of Animal husbandry, Dairying and Fisheries in co-operation with 12 States has undertaken a Mass Embryo Transfer programme in Indigenous Breeds under the scheme, National Mission on Bovine Productivity.

It has been planned to carry out 440 embryo transfers during October 2-10, 2017 throughout the country. The programme is implemented with the objective of conservation and development of indigenous breeds under Rashtriya Gokul Mission.

Through the use of ETT, (i) a farmer can get a 5-6 fold increase in the number of offsprings, (ii) the calves so born will be of high genetic merit and (iii) the offsprings born will be free from diseases.

The programme has been initiated in 12 ETT centres across the country from 2nd October and will continue till 10th October 2017. Under this programme, embryos of higher genetic merit indigenous bovines are being transferred into surrogate cows.

Embryos of Indigenous breeds such as Sahiwal, Gir, Red Sindhi, Ongole, Deoni and Vechur have been proposed to be transferred under this programme. On the first day of ET programme held on 2nd October, 35 Nos. of embryos were transferred into recipients.

Remaining will be transferred on different days till 10th of October 2017.The technology now being taken up to the doorstep of the farmers will result in rapid propagation of high genetic merit indigenous cattle

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2017 Nobel Peace Prize

The 2017 Nobel Peace Prize was awarded to a group campaigning for nuclear disarmament — a decision that comes amid growing tensions between the U.S. and North Korea and as President Donald Trump reportedly considers ending a nuclear deal with Iran.

The Nobel Committee honoured the International Campaign to Abolish Nuclear Weapons (ICAN) for drawing attention to “the catastrophic humanitarian consequences of any use of nuclear weapons” and for its efforts toward nuclear prohibition.

ICAN is a coalition of non-governmental organizations from around 100 different countries around the globe.

The Nobel committee said ICAN has given the movement toward the world without nuclear weapons a new direction and new vigour.

The Nobel committee emphasized that the next steps towards attaining a world free of nuclear weapons must involve the nuclear-armed states and is calling upon these states to initiate negotiations to the gradual elimination of the world’s 15,000 nuclear weapons.

Trump is reportedly expected to announce that he will decertify the landmark 2015 nuclear deal with Iran, which he has previously called “an embarrassment to the United States.” And the escalating war of words between President Donald Trump and North Korea leader Kim Jong-un has cast new fears of a possible nuclear conflict.

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2017 Nobel prize in chemistry

Biophysicists Jacques Dubochet, Joachim Frank and Richard Henderson have won the Nobel Prize in chemistry for inventing new and better ways to see molecules.

The Nobel committee praised the trio in its announcement Wednesday “for developing cryo-electron microscopy for the high-resolution structure determination of biomolecules in solution.” Cryo-electron microscopy is “a cool method for imaging the materials of life,” said Nobel committee member Göran K. Hansson from Stockholm. The development allows scientists to visualize proteins and other biological molecules at the atomic level.

Dubochet, 75, a Swiss citizen, is a professor at the University of Lausanne in Switzerland. Frank, 77, born in Germany and now a U.S. citizen, is a Columbia University professor in New York. Henderson, 72, of Scotland, works at Cambridge University in Britain.

To see the structure of molecules at ultrahigh resolution, scientists must hold molecules in place in their natural configuration. Other microscopic techniques, such as X-ray crystallography, are far more rigid than cryo-electron microscopy.

What is cryo-electron microscopy?

“Cryo”, short for cryogenic refers to very low temperatures. Though the actual temperature is not well defined, it is below minus 150°C. In the context of electron microscopy, it refers to the fact that the object to be imaged is frozen to such low temperatures to facilitate being studied under the beam of the electron microscope.

This method is so effective that even in recent times, it has been used to image the elusive Zika virus: When researchers began to suspect that the Zika virus was causing the epidemic of brain-damaged newborns in Brazil, they turned to cryo-EM to visualise the virus. Over a few months, three dimensional (3D) images of the virus at atomic resolution were generated and researchers could start searching for potential targets for pharmaceuticals.

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A rapid test to diagnose Zika and dengue

An international team, including researchers from India, has developed a low-cost, rapid diagnostic test for diagnosing Zika and dengue viruses and differentiating the four serotypes of dengue virus. None of the rapid tests available is capable of differentiating the four dengue virus serotypes.

While many diagnostic tests cannot strictly distinguish between Zika and dengue infections, the test has nearly 100% ability to distinguish between the two virus infections. Science Translational Medicine published the results.

The diagnostic test has nearly 76-100% sensitivity and specificity in the case of dengue, while the sensitivity is 81% and specificity 86% in the case of Zika.

The researchers injected specific flavivirus nonstructural 1 (NS1) proteins produced by Zika and dengue viruses into mice to generate monoclonal antibodies. They identified pairs of antibodies that can specifically detect and distinguish each of the four dengue serotype NS1 proteins as well as the Zika NS1 protein. They took the antibody pairs and coated each antibody on a strip of chromatography paper at two different spots. One of these antibodies was attached to gold nanoparticles.

“When a serum sample from a patient is added to the chromatography paper where the antibody is spotted, the antigen present in the serum binds to the first antibody. Since it is paper, the antigen bound to the antibody diffuses and comes in contact with the second antibody. The second antibody also binds to the antigen leading to the formation of colloidal aggregates, which then forms a pink spot,”

The appearance of the pink spot indicates positivity to either Zika virus or dengue virus. And in the case of a serotype test, it indicates the respective dengue virus serotype.

The team has also developed a pan-dengue strip which indicates positivity to dengue virus without cross-reacting with Zika NS1, unlike the current kits. The strip cannot differentiate between the four serotypes.

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Nobel prize in physics awarded for discovery of gravitational waves

Three American physicists have won the Nobel prize in physics for the first observations of gravitational waves, ripples in the fabric of spacetime that were anticipated by Albert Einstein a century ago.

Rainer Weiss has been awarded one half of the 9m Swedish kronor (£825,000) prize, announced by the Royal Swedish Academy of Sciences in Stockholm on Tuesday. Kip Thorne and Barry Barish will share the other half of the prize.

Analysis ‘A new way to study our universe’: what gravitational waves mean for future science

The 2017 physics Nobel prize was awarded for the detection of gravitational waves. But what else could be revealed now that this discovery has been made?

All three scientists have played leading roles in the Laser Interferometer Gravitational-Wave Observatory, or Ligo, experiment, which in 2015 made the first historic observation of gravitational waves triggered by the violent merger of two black holes a billion light-years away.

Prof Olga Botner, a member of the Nobel committee for physics, described this as “a discovery that shook the world”.

The Ligo detections finally confirmed Einstein’s century-old prediction that during cataclysmic events the fabric of spacetime itself can be stretched and squeezed, sending gravitational tremors out across the universe like ripples on a pond.

The direct detection of gravitational waves also opens a new vista on the “dark” side of the cosmos, to times and places from which no optical light escapes. This includes just fractions of a second after the Big Bang, 13.7 billion years ago, when scientists believe gravitational waves left a permanent imprint on the cosmos that may still be perceptible today.

The notion that space-time is malleable was first predicted by Einstein’s general theory of relativity. But Einstein himself was unsure whether this was merely a mathematical illusion, and concluded that, in any case, the signal would be so tiny that it would “never play a role in science”.

It was a significant career gamble then, when in the mid-1970s Weiss and Thorne, who is now the Feynman professor of theoretical physics at California Institute of Technology, began the decades-long quest to detect gravitational waves, which they believed could revolutionise our understanding of the universe.
Weiss designed a detector, called a laser-based interferometer, that he believed would be capable of measuring a signal so tiny that it could easily be masked by the background murmur of the ocean waves. Thorne, a theorist, began making crucial predictions of what the signal of a gravitational wave emanating from two black holes colliding would actually look like.

Independently, Ronald Drever, a Scottish physicist, also began building prototype detectors in Glasgow and after moving to Caltech, he, Weiss and Thorne formed a trio that laid the groundwork for Ligo. Drever died in March after suffering from dementia, and while the Nobel prize is not normally awarded posthumously, he is widely recognised as having made a decisive contribution.

Barry Barish, a former particle physicist at California Institute of Technology (now an Emeritus professor) came to the project at a much later stage but is often credited for making Ligo happen. When he took over as its second director in 1994, the project was at risk of being cancelled. Barish turned things around and saw it through to construction.

In the end, detection required a peerless collaboration between experimentalists, who built one of the most sophisticated detectors on Earth, and theorists, who figured out what a signal from two black holes colliding would actually look like.

Ligo’s twin detectors, two pairs of 4km-long perpendicular pipes, one in Hanford, Washington state, the other in Livingston, Louisiana, are so sensitive that they can spot a distortion of a thousandth of the diameter of an atomic nucleus across a 4km length of a laser beam.

The phenomenon detected was the collision of two giant black holes, one 35 times the mass of the sun, the other slightly smaller, 1.3 billion light-years away. At the start of the 20-millisecond “chirp” in the signal, the two objects were found to be circling each other 30 times a second. By the end, the rate had accelerated to 250 times a second before meeting in a violent collision.

Since then, three further black hole collisions have been made and rumours are afoot that the consortium may have also observed the collision of a pair of neutron stars. In the future, scientists hope to supernovae, pulsars and the insides of stars as they collapse into black holes. A network of gravitational-wave observatories could even allow us to gaze back to almost the beginning of time itself.

Last year’s prize went to three British physicists for their work on exotic states of matter that may pave the way for quantum computers and other revolutionary technologies.

Read Also:

Gravitational Waves

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India Third in Nuclear Power Installations: Study

India is third in the world in the number of nuclear reactors being installed, at six, while China is leading at 20, the World Nuclear Industry Status Report 2017, released this month, shows. The number of nuclear reactor units under construction is, however, declining globally for the fourth year in a row, from 68 reactors at the end of 2013 to 53 by mid-2017, the report says.

The latest report further reveals that most nuclear reactor construction is behind schedule, with delays resulting in an increase in project costs and delay in power generation. There are 37 reactor constructions behind schedule, of which 19 reported further delays over the past year. In India itself, five out of the six reactors under construction is behind schedule. Eight nuclear power projects have been under construction globally for a decade or more, of which three have been so for over 30 years.

Data gathered by the authors shows that global nuclear power generation increased by 1.4% in 2016 due to a 23% increase in China, though the share of nuclear energy in electricity generation stagnated at 10.5%. By comparison, globally, wind power output grew by 16% and solar power by 30%. Wind power increased generation by 132 TWh (terawatt hours) or 3.8 times, and solar power by 77 TWh or 2.2 times more than nuclear power’s 35 TWh respectively. Renewables represented 62% of global power generating capacity additions.

Russia and the U.S. shut down reactors in 2016, while Sweden and South Korea both closed their oldest units in the first half of 2017, the report notes.

Financial crisis

The report also documents the financial crisis plaguing the industry. After the discovery of massive losses over its nuclear construction projects, Toshiba filed for bankruptcy of its U.S. subsidiary Westinghouse, the largest nuclear power builder in history. AREVA has accumulated $12.3 billion in losses over the past six years.

French bailout

The French government has provided a $5.3 billion bailout and continues its break-up strategy, the report notes.

In the chapter on the status of the Fukushima nuclear power project in Japan, six years after the disaster began, the report notes how the total official cost estimate for the catastrophe doubled to $200 billion.

The lead authors of the report are Paris-based energy consultant Mycle Schneider, who advised the European Parliament on energy matters for over 20 years, and Antony Froggart, energy policy consultant and senior researcher at Chatham House, a London-based non-profit organisation working on international affairs.

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