Current Affairs May 4 – GES Reporter

Pfizer vaccine

Why in News?

The European Union’s drug regulator s has begun evaluating a request by Pfizer Inc and BioNTech to extend approval of their coronavirus vaccine to include children ranging in age from 12 to 15.
The European Medicines Agency’s human medicines committee will carry out an accelerated assessment of data submitted by Pfizer and BioNTech and is expected to reach a decision in June, unless it requires extra information.
The children will continue to be monitored for longer-term protection and safety for another two years.
The companies’ vaccine is currently approved for use in people ages 16 years and older. Extending that approval to the younger age group could offer younger and less at-risk populations in Europe access to the shot for the first time.
Most COVID-19 vaccines approved by authorities around the world are for adults, who are at higher risk, but health officials believe vaccinating children of all ages will be critical to stopping the pandemic. Some research has shown that older children may play a role in spreading the virus.

THE HINDU

Kuiper, the father of modern planetary science

Kuiper Belt a disc-shaped region outside the orbit of Neptune, the Kuiper Belt consists of a lot of icy objects. Apart from being home to plenty of celestial objects and minor planets, the region also produces many comets. It is named after astronomer Gerard Kuiper, who speculated about the existence of such a disc decades before it was actually observed.
Born in 1905 in a village in northern Holland, Kuiper was meant to be an astronomer from birth.
Kuiper made a number of discoveries that advanced the field of planetary science.
In 1947, Kuiper predicted correctly that carbon dioxide is a major component of Mars’ atmosphere. In that same year, he also correctly predicted that the rings of Saturn are composed of ice particles, and discovered Miranda, Uranus’ fifth moon.
In 1949, he discovered Nereid, Neptune’s moon. He also proposed a theory for the origin of the solar system in that year. He suggested that planets had been formed by the condensation of a large cloud of gas around the sun.
It was in 1951 that he proposed the existence of what we now call the Kuiper Belt.
Even though he wasn’t the first to think of the idea (Irish astronomer, engineer and economist Kenneth Edgeworth had proposed the existence of such a disc of bodies), it is Kuiper’s name that is now associated with it.
Kuiper not only used this idea to offer an explanation as to why there were no large planets beyond Neptune, but also suggested that objects from this disc wandered into the solar system as a comet, thereby explaining their origins as well.
Kuiper was also able to prove in 1956 that Mars’ polar ice caps were not made up of carbon dioxide as had been previously believed, but were actually composed of frozen ice.
He also predicted in 1964 that our moon’s surface would be “like crunchy snow” to walk on, something that was later verified by U.S. astronaut Neil Armstrong in 1969.

Influential role

Kuiper’s role was influential in the development of infrared airborne astronomy in the 1960s and 1970s. Using these, Kuiper studied the spectroscopy of the sun, stars and planets, something impossible from ground-based observatories.

More about Nereid

Nereid, Neptune’s moon, is named after the Nereids, which are sea-nymphs in Greek mythology. It was Kuiper who proposed the name following his discovery on May 1, 1949.
Kuiper made the discovery using a ground-based telescope. It was the last of Neptune’s satellites to be discovered until Voyager 2’s discoveries came about four decades later.
Nereid is among the largest and outermost of Neptune’s known moons with one of the most eccentric orbits for any satellite in our solar system.

THE HINDU

Single COVID-19 vaccine dose

Why in News?

A single dose of COVID-19 vaccine boosts protection against SARS-CoV-2 coronavirus variants, but only in those previously infected with the disease.
The researchers looked at the U.K. and South Africa variants, however, it is possible that the findings will apply to other variants in circulation, such as the Brazil (P.1) and India (B.1.617 and B.1.618) variants.

Findings

In those who have not previously been infected and have so far only received one dose of vaccine, the immune response to coronavirus variants of concern may be insufficient.
People who had previously had mild or asymptomatic infection had significantly enhanced protection against the Kent and South Africa variants, after a single dose of the mRNA vaccine. In those without prior COVID-19, the immune response was less strong after a first dose, potentially leaving them at risk from variants.
Study highlights the importance of getting second doses of the vaccine rolled out to protect the population.
Along with antibodies, the researchers also focused on two types of white blood cell: B-cells, which ‘remember’ the virus, and T cells, which help B cell memory and recognise and destroy cells infected with coronavirus.
They found that after a first dose of vaccine, prior infection was associated with a boosted T cell, B cell and neutralising antibody response, which could provide effective protection against SARS-CoV-2, as well as the Kent and South Africa variants.
The mutations in the Kent and South Africa variants resulted in T cell immunity which could be reduced, enhanced or unchanged compared to the original strain, depending on genetic differences between people.

THE HINDU

A Malaria Vaccine Candidate

Why in News?

A malaria vaccine candidate has shown promise in phase 2b clinical trials, with high efficacy at 77%.

The previous version

The new vaccine candidate, called R21/Matrix M, is a modified version of RTS, S — another candidate against malaria that has been in development for more than 30 years by Walter Reed Institute of Research, GlaxoSmithKline and Bill and Melinda Gates Foundation with the PATH Malaria Vaccine Initiative.
This vaccine is designed to stop the Plasmodium falciparum malaria parasite from entering the liver and preventing the subsequent deadly blood stages. It targets the liver stage protein of the Plasmodium falciparum life cycle.
Thirty years in the making, RTS,S is the first, and to date the only, vaccine to reduce malaria in children. But it is not highly efficacious.

The new version

R21/Matrix M has been developed by scientists at University of Oxford, the same location where the AstraZeneca Covid-19 vaccine was developed.
They’ have been working on this version for almost 6-7 years now.
This vaccine was produced in the Serum Institute of India.

Why it matters

In 2019, there were an estimated 229 million cases of malaria and 409 000 malaria-related deaths in 87 countries. Children under the age of 5 in sub-Saharan Africa accounted for approximately two-thirds of global deaths.
Between 2000 and 2020, 24 countries reported zero indigenous cases of malaria for 3 or more years. This is the benchmark for the World Health Organization (WHO) certification of a country as malaria-free. Globally, 39 countries have achieved the milestone.
In 2019, India had an estimated 5.6 million cases of malaria compared to about 20 million cases in 2020 according to WHO. The 2020 cases estimates (global, regional and country level) will be published later this year.

3D heart scans

Patients with life-threatening coronary heart disease will be treated five times faster thanks to 3D scans being introduced on the NHS that allow for a diagnosis in just 20 minutes.
The revolutionary technology can turn a regular CT scan of the heart into a 3D image, allowing doctors to diagnose them rapidly.
Patients – who would previously have had to undergo an invasive and time-consuming angiogram in hospital – will now be seen, diagnosed and treated around five times faster.
The new technology, introduced recently, is part of the NHS long-term plan to cut the number of heart attacks and strokes by 150,000.

THE GUARDIAN

Receding glaciers causing rivers to suddenly disappear

As glaciers around the world recede rapidly owing to global warming, some communities are facing a new problem: the sudden disappearance of their rivers.
River piracy, or stream capture, is when water from one river is diverted into another because of erosion or, in this case, glacier melt.
Scientists predict as we move towards a world with far fewer glaciers, land that has been continuously covered by ice for many centuries will become ice-free, thus redirecting rivers in high mountain areas.
In most instances, the redirection will be inconsequential. But in some areas with various user groups that rely on the river’s flow, the changes might have a more significant impact.
Canada’s largest glacier melted so quickly it diverted a large river, and thus significantly reduced the water level of a lake it fed.

THE GUARDIAN

Air pollution spikes may impair older men’s thinking

Temporary rises in air pollution may impair memory and thinking in older men, according to research that indicates even short-term spikes in airborne particles can be harmful to brain health.
Scientists found that the men’s cognitive performance fell following rises in air pollution during the month before testing, even when peak levels remained below safety thresholds for toxic air set by the World Health Organization and national regulators.

Findings

The findings build on growing evidence that exposure to fine particulate matter in the air, largely from road vehicles and industry, is harmful not only to the heart and lungs, but also to delicate neural tissues in the brain.
Test scores were less affected by short-term rises in air pollution if the men were taking aspirin or other non-steroidal anti-inflammatory drugs, known as NSAIDs.
Such painkillers may help by reducing inflammation that is triggered by fine particles getting into the brain.
The impact of toxic air on respiratory and cardiovascular health is well-established and evidence for damage to the brain is mounting.
Studies have linked air pollution to reduced intelligence and dementia.

THE GUARDIAN

Nano flashlight

Why in News?

In work that could turn cell phones into sensors capable of detecting viruses and other minuscule objects, MIT researchers have built a powerful nanoscale flashlight on a chip.
Their approach to designing the tiny light beam on a chip could also be used to create a variety of other nano flashlights with different beam characteristics for different applications.
Scientists have long used light to identify a material by observing how that light interacts with the material.
They do so by essentially shining a beam of light on the material, then analyzing that light after it passes through the material.
Because all materials interact with light differently, an analysis of the light that passes through the material provides a kind of “fingerprint” for that material.
Imagine doing this for several colors, i.e. several wavelengths of light, and capturing the interaction of light with the material for each color. That would lead to a fingerprint that is even more detailed.
Most instruments for doing this, known as spectrometers, are relatively large.
Making them much smaller would have a number of advantages.

PHYS.org

Top Quarks at high and not-so-high energies

Why in News?

CERN’s Large Hadron Collider (LHC) is famous for colliding protons at world-record energies—but sometimes it pays to dial down the energy and see what happens under less extreme conditions.
One particle they were especially keen to study was the top quark.
As the heaviest-known elementary particle, the rate (or cross-section) for producing top-quark pairs depends very strongly on the collision energy achieved.
By measuring the production rate at different energies, scientists can learn more about the distributions of the quarks and gluons that make up the proton.
Top quarks decay rapidly and leave a distinct signature in the detector.
To spot top-pair collision events, ATLAS physicists looked for events with two electrons, two muons, or an electron–muon pair, one or two ‘b-tagged’ jets of particles (coming from b-quark decays), and a significant momentum imbalance indicating the presence of a neutrino.
This selection heavily suppresses background events from the production of other types of particles, particularly in the case of electron–muon events.
In events with either two electrons or two muons, there is still a large background from events with Z bosons to contend with.
Physicists reduced this background using the measured energies and angles of the electrons and muons, requiring their combination to be inconsistent with originating from a Z boson decay.

Phys.org

Earthquake, tsunami hazards from subduction zones

Two of the most destructive forces of nature—earthquakes and tsunamis—might actually be more of a threat than current estimates according to new research.
The researchers developed a new method to assess earthquake and tsunami hazards represented by the most distant part of offshore subduction zones and found that the hazard might have been systematically underestimated in some areas, meaning that tsunami risk assessments should be redone given the new results.
The findings have important implications for the mitigation of risk in affected areas worldwide, including Southeast Asia and the Pacific Rim, in the event of future earthquakes and tsunamis.
Megathrust earthquakes are among the most powerful earthquakes experienced worldwide and occur in subduction zones, where two tectonic plates converge, and one slides under the other.
The plates move toward each other continuously, but if the interface, or fault, between them is stuck, then a slip deficit builds up over time.
Like a debt, this slip deficit has to be paid off eventually, and for tectonic plates pay day is earthquake day. When these earthquakes affect the shallowest part of the fault near the seafloor, they have the potential to shift the seafloor upward and create devastating tsunamis as well.
Understanding the potential rupture behavior of megathrusts, particularly in the shallow offshore part of the fault where most destructive tsunamis are generated, is therefore a critical task for geoscientists forecasting seismic and tsunami inundation hazards.
The likelihood of seismic behavior is often assumed to be somewhat low in the shallow part of the fault.
Now, scientists developed a new geodetic method for inferring this value that accounts for the interaction between different parts of the fault, resulting in a much more physically accurate result.
Previous models have failed to take into account the fact that if the deep part of the fault is stuck between earthquakes, the shallow part can’t move either—it is in what they term a ‘stress shadow’ and there is no buildup of energy available to cause it to slip.
By taking this effect into account, the team developed a technique that uses the same land-based data but results in a vast improvement in their ability to “see” the fault slip in the areas that are farthest from shore, allowing researchers to reassess the hazard presented by the offshore parts of subduction zones most prone to tsunami generation.
Applied this technique to the Cascadia and Japan subduction zones and found that wherever deeper locked patches are present, the shallow fault must also have a high slip deficit—regardless of its own frictional properties.
If these areas can slip seismically, global tsunami hazard could be higher than currently recognized.

Phys.org