Daily Quiz: UPSC Prelims Marathon (Science & Technology ) – July 9, 2020

Acute encephalitis syndrome (AES) is a serious public health problem in India. It is characterized as acute-onset of fever and a change in mental status (mental confusion, disorientation, delirium, or coma) and/or new-onset of seizures in a person of any age at any time of the year.

• The syndrome most commonly affects children and young adults and can lead to considerable morbidity and mortality.
• Viruses are the main causative agents in AES cases, although other sources such as bacteria, fungus, parasites, spirochetes, chemicals, toxins and noninfectious agents have also been reported over the past few decades.
• In May-June 2019, the acute encephalitis syndrome (AES) in Bihar’s Muzaffarpur, Vaishali, Sheohar and East Champaran districts has so far claimed the lives of over 100 children.
• More than 400 children with AES have been admitted to various hospitals. Most of the deaths have been attributed to low blood sugar level (hypoglycaemia).
• In Bihar, convulsions in children (which is AES) are found in combination with hypoglycaemia.

Japanese Encephalitis (JE) is a mosquito-borne viral infection of the brain. There is, however, a debate about the origin of the disease and whether it is enteroviruses — caused by virus found in pigs and birds. There is no cure for JE.

• The efficacy of the JE vaccine is between 85-90%. The lessons learnt from polio vaccination drives is that people left out of each round of vaccination are the most disenfranchised, most likely to take ill and least likely to seek medical care in time.
• One hundred and ninety positive cases of Japanese Encephalitis (JE) have been reported and 49 people have died of the vector-borne disease in Assam since January 2019 to June 2019.
• Assam is an ecologically favorable region for the spread of JE due to heavy rainfall, large paddy fields and water bodies and pig farming almost throughout the State.
• Pigs act as amplifying host for the JE virus transmitted through culex mosquito, as do wading birds such as herons and egrets.
  

A virus named after Kampung Sungai Nipah, a village in Malaysia, where it was first discovered in 1998-99.

• According to the World Health Organization (WHO) Nipah is Zoonotic Virus. “A zoonosis is any disease transmitted from vertebrate animals to humans.”
• It could be caused by a virus, bacteria, fungi or parasite; some examples include anthrax, bird flu, ebola, dengue, rabies, malaria, swine flu and leptospirosis.
• Nipah is believed to be transmitted from what are called flying foxes, or mega bats, so called because they are the largest bat species. They eat fruits and live in trees.
• These are a part of the old-world fruit bat family, called pteropid bats. Bats often end up being reservoirs for a number of severe infectious diseases, including Ebola, SARS coronavirus, Nipah and Hendra.
• Nipah is an RNA or Ribonucleic Acid virus. “RNA viruses are the most common cause of emerging diseases in humans, attributable to the high mutation rate in RNA viruses compared to DNA viruses,” says the book Essential Human Virology.
• Nipah belongs to a genus (category, in layperson speak) called the Henipavirus; the Hendra virus, also found on pteropid bats, belongs to this category too.
• The virus, which is classified as Bio-safety Level 4, meaning that it is highly infectious and needs a maximum containment facility, can be confirmed by an ELISA, RT-PCR or Serum Neutralization Test.
• The incubation period is anywhere between 5-14 days, but it can soon affect the respiratory and nervous system and patients can go into delirium or coma. Unfortunately, there is no definite treatment, except intensive supported care.

On September 3 (2019), Bangladesh, Bhutan, Nepal and Thailand became the first four countries in the World Health Organization’s south-east Asia region to have successfully controlled hepatitis B. The virus is said to be controlled when the disease prevalence is reduced to less than 1% among children less than five years of age.

A potential vaccine against diarrhea has been proven safe and effective in an early stage clinical trial carried out in Bangladesh in November 2019.

• The study, published in the journal The Lancet Infectious Diseases, studied the safety and effectiveness of an oral, inactivated vaccine candidate — ETVAX — against toxin-producing coli bacteria which caused diarrhea.
• According to the researchers, including those from the University of Gothenburg in Sweden, the specific type of the bacteria are the primary cause of diarrhea, leading to substantial illness and death in children in low- and middle-income countries (LMICs) as well as in travelers to LMICs.

According to the Directorate General Foreign Trade (DGFT) Beach Sand Minerals (BSM) comprised a suite of seven minerals.

• They are limonite, rutile, leucoxene (titanium being mineral), zircon (zirconium being mineral), garnet, sillimanite and monazite (a proscribed substance under the Atomic Energy Act of 1962 since it covers uranium and thorium).
• The suites of BSM were also called atomic minerals. Except garnet and sillimanite, others were prescribed substances under the Atomic Energy Act.

Mankind has known materials such as gold, silver, mercury, iron, phosphorous, sulphur and others since antiquity.

• Alchemists tried making gold out of “base” metals — with no success. But we had to wait until the English school teacher John Dalton who in 1808 came up with his “new system of chemical philosophy”, where he proposed that chemical elements are made of atoms;
• Any given element is made entirely of one kind of atom and that each atom has a characteristic weight; chemical reactions occur when atoms of different elements interact with one another.
• Dalton and Thomas Thomson from England and Berzelius from Europe defined the weight of a hydrogen atom as one, and the atomic weights of other elements were measured using this standard.
• By the 1860s, the atomic weights of a large number of elements were published.

A new initiative aims at reducing the population of Aedes aegypti mosquito by introducing genetically modified version of mosquitoes.

• Aedes aegypti mosquito is the carrier of diseases such as Zika, dengue and chikungunya.
• The genetic strategy employed to control A. aegypti population known as RIDL (the Release of Insects carrying Dominant Lethal genes) is to reduce the population of the naturally occurring A. aegypti mosquitoes and not affect or alter their genetics.

The Food Safety and Standards Authority of India (FSSAI) seized one tonne of artificially ripened bananas and plantains from a market in Tiruppur (Tamil Nadu). According to FSSAI officials, a trader had used ripening agent ethephon (2-chloroethylphosphonic acid) on the bananas and plantains kept for sale.

The Zoological Survey of India (ZSI), with help from Gujarat’s forest department, is attempting for the first time a process to restore coral reefs using biorock or mineral accretion technology.

• A biorock structure was installed one nautical mile off the Mithapur coast in the Gulf of Kachchh.
• Biorock is the name given to the substance formed by electro accumulation of minerals dissolved in seawater on steel structures that are lowered onto the sea bed and are connected to a power source, in this case solar panels that float on the surface.
• The technology works by passing a small amount of electrical current through electrodes in the water.
• When a positively charged anode and negatively charged cathode are placed on the sea floor, with an electric current flowing between them, calcium ions combine with carbonate ions and adhere to the structure (cathode).
• This results in calcium carbonate formation. Coral larvae adhere to the CaCO3 and grow quickly.