Category Science

Coronaviruses are unsegmented single-stranded RNA viruses ranging from 26 to 32 kilobases in length, belonging to the subfamily Coronavirinae of the family Coronaviridae of the order Nidovirales.

In December 2019, 27 patients out of the 41 people admitted to hospitals due to mysterious lung disease, passed through a wet market in Wuhan City. Though the origin of the virus has been traced to the market, the very first human case identified did not go to the market often. Instead, based on SARS-CoV-2 genomic sequences, the first case can be traced back to November 2019.

In a study conducted by Canadian scientists, they sequenced nearly 30,000-base genome of the SARS-associated coronavirus, called the Tor2 isolate. They found that the novel coronavirus, SARS-CoV-2, is only moderately associated with other known coronaviruses, such as the OC43 and the 229E.  

Further, the researchers found that SARS-CoV-2 belongs to the group of Betacoronaviruses, which are similar to the SARS-CoV from 2002. During that time, it was found that bats of the genus Rhinolophus were the reservoir of the virus. It was also revealed that a palm civet, a long-bodied, short-legged cat-like carnivore of the family Viverridae, was the intermediate host of the virus before it jumped to humans. In 2012, the MERS-CoV also jumped to humans through dromedary camels.

 

Picture Credit : Google

Proteins are essential to life, supporting practically all its functions. They are large complex molecules, made up of chains of amino acids, and what a protein does largely depends on its unique 3D structure. Figuring out what shapes proteins fold into is known as the “protein folding problem”, and has stood as a grand challenge in biology for the past 50 years. In a major scientific advance, the latest version of our AI system AlphaFold has been recognised as a solution to this grand challenge by the organisers of the biennial Critical Assessment of protein Structure Prediction (CASP). This breakthrough demonstrates the impact AI can have on scientific discovery and its potential to dramatically accelerate progress in some of the most fundamental fields that explain and shape our world.

In 1994, Professor John Moult and Professor Krzysztof Fidelis founded CASP as a biennial blind assessment to catalyse research, monitor progress, and establish the state of the art in protein structure prediction. It is both the gold standard for assessing predictive techniques and a unique global community built on shared endeavour. Crucially, CASP chooses protein structures that have only very recently been experimentally determined (some were still awaiting determination at the time of the assessment) to be targets for teams to test their structure prediction methods against; they are not published in advance. Participants must blindly predict the structure of the proteins, and these predictions are subsequently compared to the ground truth experimental data when they become available. We’re indebted to CASP’s organisers and the whole community, not least the experimentalists whose structures enable this kind of rigorous assessment.

The main metric used by CASP to measure the accuracy of predictions is the Global Distance Test (GDT) which ranges from 0-100. In simple terms, GDT can be approximately thought of as the percentage of amino acid residues (beads in the protein chain) within a threshold distance from the correct position. According to Professor Moult, a score of around 90 GDT is informally considered to be competitive with results obtained from experimental methods.

In the results from the 14th CASP assessment, released today, our latest AlphaFold system achieves a median score of 92.4 GDT overall across all targets. This means that our predictions have an average error (RMSD) of approximately 1.6 Angstroms, which is comparable to the width of an atom (or 0.1 of a nanometer). 

 

Picture Credit : Google

Streptococcus is a genus of gram-positive coccus (plural cocci) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Firmicutes.Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically).

Group A strep causes

• Strep throat – a sore, red throat. Your tonsils may be swollen and have white spots on them.
• Scarlet fever – an illness that follows strep throat. It causes a red rash on the body.
• Impetigo – a skin infection
• Toxic shock syndrome
• Cellulitis and necrotizing fasciitis (flesh-eating disease)

Group B strep can cause blood infections, pneumonia and meningitis in newborns. A screening test during pregnancy can tell if you have it. If you do, intravenous (IV) antibiotics during labor can save your baby’s life. Adults can also get group B strep infections, especially if they are 65 or older or already have health problems. Strep B can cause urinary tract infections, blood infections, skin infections and pneumonia in adults.

 

Picture Credit : Google

When we talk about tectonic or lithospheric plates, we mean the sections into which the lithosphere is cracked. The surface of the Earth is divided into 7 major and 8 minor plates. The largest plates are the Antarctic, Eurasian, and North American plates.

The mechanism by which tectonic plates move is still a subject of much debate among Earth scientists. The Earth is dynamic thanks to its internal heat, which comes from deep within the mantle from the breakdown of radioactive isotopes. It was long thought that this resulted in convection currents in the mantle which were responsible for the movement of tectonic plates across the Earth’s surface – indeed this is still the most common idea illustrated in many textbooks and on the internet. However, this theory is now largely out of favour, with modern imaging techniques unable to identify mantle convection cells that are sufficiently large to drive plate movement. Some plate models show that two thirds of the Earth’s surface move faster than the underlying mantle so there appears to be little or no evidence that convection currents in the mantle move plates (apart maybe from some very small plates in unusual circumstances).

Where slab pull is not the main plate driver, ‘ridge push’ is another possibility. As the lithosphere formed at divergent plate margins is hot, and less dense than the surrounding area it rises to form oceanic ridges. The newly-formed plates slide sideways off these high areas, pushing the plate in front of them resulting in a ridge-push mechanism.

 

Picture Credit : Google

The amygdaloid body is also known as the amygdaloid nucleus. This is an oval structure located within the temporal lobe of the human brain. The structure is a small part of the brain and is closely associated with the hypothalamus, cingulated gyrus, and hippocampus.

The amygdala is an important part of the brain, which assists in responses of fear and pleasure. The abnormal working of the amygdaloid body can lead to various clinical conditions including developmental delay, depression, anxiety, and autism.

A simple view of the information processing through the amygdala follows as- the amygdala sends projections to the hypothalamus, the dorsomedial thalamus, the thalamic reticular nucleus, the nuclei of the trigeminal nerve and the facial nerve, the ventral tegmental area, the locus coeruleus, and the laterodorsal tegmental nucleus. The basolateral amygdala projects to the nucleus accumbens, including the medial shell.

The amygdala is also involved in the modulation of memory consolidation. Following any learning event, the long-term memory for the event is not formed instantaneously. Rather, information regarding the event is slowly assimilated into long-term (potentially lifelong) storage over time, possibly via long-term potentiation. Recent studies suggest that the amygdala regulates memory consolidation in other brain regions. Also, fear conditioning, a type of memory that is impaired following amygdala damage, is mediated in part by long-term potentiation.

 

Picture Credit : Google

The Arecibo Telescope was primarily used for research in radio astronomy, atmospheric science, and radar astronomy, as well as for programs that search for extraterrestrial intelligence (SETI). Scientists wanting to use the observatory submitted proposals that were evaluated by independent scientific referees. NASA also used the telescope for near-Earth object detection programs. The observatory, funded primarily by the National Science Foundation (NSF) with partial support from NASA, was managed by Cornell University from its completion in 1963 until 2011, after which it was transferred to a partnership led by SRI International. In 2018, a consortium led by the University of Central Florida assumed operation of the facility.

Since its completion in November 1963, the Telescope had been used for radar astronomy and radio astronomy, and had been part of the Search for extraterrestrial intelligence (SETI) program. It was also used by NASA for Near-Earth object detection. Since around 2006, NSF funding support for the telescope had waned as the Foundation directed funds to newer instruments, though academics petitioned to the NSF and Congress to continue support for the telescope. Numerous hurricanes, including Hurricane Maria, had damaged parts of the telescope, straining the reduced budget.

Two cable breaks, one in August 2020 and a second in November 2020, threatened the structural integrity of the support structure for the suspended platform and damaged the dish. The NSF determined in November 2020 that it was safer to decommission the telescope rather than to try to repair it, but the telescope collapsed before a controlled demolition could be carried out. The remaining support cables from one tower failed around 7:56 a.m. local time on December 1, 2020, causing the receiver platform to fall into the dish and collapsing the telescope.

In late 2020, Wanda Vázquez Garced, then governor of Puerto Rico signed an executive order for $8 million for the removal of debris and for the design of a new observatory to be built in its place. The governor stated reconstruction of the observatory is a “matter of public policy”. The executive order also designated the area as a history site.

 

Picture Credit : Google

The ASKAP telescope makes images of radio signals from the sky, allowing astronomers to view the Universe at wavelengths that our eyes cannot see. It is a type of radio telescope known as an ‘interferometer’. This means it uses many antennas acting together as one large telescope. In our case, ASKAP has 36 dish antennas spread out over six kilometres in outback Western Australia.

ASKAP’s key feature is its wide field of view, generated by its unique chequerboard Phased Array Feed (PAF) receivers. Together with specialised digital systems, a PAF creates 36 separate (simultaneous) beams on the sky which are mosaicked together into a large single image. This gives ASKAP the ability to rapidly survey large areas of the sky – making it one of the world’s fastest survey radio telescopes. ASKAP will help to answer some of the most fundamental questions of 21st century astronomy and astrophysics involving dark matter, dark energy, the nature of gravity, the origins of the first stars, the evolution of galaxies and the properties of magnetic fields in space.

ASKAP is located at CSIRO’s Murchison Radio-astronomy Observatory (MRO) in Western Australia (WA). The MRO is about 700 kilometres north of Perth in the Murchison Shire, on the traditional lands of the Wajarri Yamaji. Situated in Mid West WA, the Shire covers an area of 49,500 square kilometers and has a population of 120 people.

This remote location is ideal for radio astronomy as there is minimal interference from Earth-based radio transmissions. In the same way that it is necessary for us to avoid city-lights when we’re looking up at the stars, radio telescopes must avoid other radio communication networks that disrupt the signals being received from space.  

 

Picture Credit : Google

The 1967 article “On the Origin of Mitosing Cells” in the Journal of Theoretical Biology by Lynn Margulis (then Lynn Sagan) is widely regarded as stimulating renewed interest in the long-dormant endosymbiont hypothesis of organelle origins.

In 1966, as a young faculty member at Boston University, Margulis wrote a theoretical paper titled “On the Origin of Mitosing Cells”. The paper, however, was “rejected by about fifteen scientific journals,” she recalled. It was finally accepted by Journal of Theoretical Biology and is considered today a landmark in modern endosymbiotic theory. Weathering constant criticism of her ideas for decades, Margulis was famous for her tenacity in pushing her theory forward, despite the opposition she faced at the time. The descent of mitochondria from bacteria and of chloroplasts from cyanobacteria was experimentally demonstrated in 1978 by Robert Schwartz and Margaret Dayhoff. This formed the first experimental evidence for the symbiogenesis theory. The endosymbiosis theory of organogenesis became widely accepted in the early 1980s, after the genetic material of mitochondria and chloroplasts had been found to be significantly different from that of the symbiont’s nuclear DNA.

 

Picture Credit : Google

Helium is used as a cooling medium for the Large Hadron Collider (LHC), and the superconducting magnets in MRI scanners and NMR spectrometers. It is also used to keep satellite instruments cool and was used to cool the liquid oxygen and hydrogen that powered the Apollo space vehicles.

Because of its low density helium is often used to fill decorative balloons, weather balloons and airships. Hydrogen was once used to fill balloons but it is dangerously reactive.

Because it is very unreactive, helium is used to provide an inert protective atmosphere for making fibre optics and semiconductors, and for arc welding. Helium is also used to detect leaks, such as in car air-conditioning systems, and because it diffuses quickly it is used to inflate car airbags after impact.

A mixture of 80% helium and 20% oxygen is used as an artificial atmosphere for deep-sea divers and others working under pressurised conditions.

Helium-neon gas lasers are used to scan barcodes in supermarket checkouts. A new use for helium is a helium-ion microscope that gives better image resolution than a scanning electron microscope.

After hydrogen, helium is the second most abundant element in the universe. It is present in all stars. It was, and is still being, formed from alpha-particle decay of radioactive elements in the Earth. Some of the helium formed escapes into the atmosphere, which contains about 5 parts per million by volume. This is a dynamic balance, with the low-density helium continually escaping to outer space.

It is uneconomical to extract helium from the air. The major source is natural gas, which can contain up to 7% helium.

 

Picture Credit : Google

Alpha-Tocopherol is the orally bioavailable alpha form of the naturally-occurring fat-soluble vitamin E, with potent antioxidant and cytoprotective activities. Upon administration, alpha-tocopherol neutralizes free radicals, thereby protecting tissues and organs from oxidative damage. Alpha-tocopherol gets incorporated into biological membranes, prevents protein oxidation and inhibits lipid peroxidation, thereby maintaining cell membrane integrity and protecting the cell against damage. In addition, alpha-tocopherol inhibits the activity of protein kinase C (PKC) and PKC-mediated pathways. Alpha-tocopherol also modulates the expression of various genes, plays a key role in neurological function, inhibits platelet aggregation and enhances vasodilation. Compared with other forms of tocopherol, alpha-tocopherol is the most biologically active form and is the form that is preferentially absorbed and retained in the body.

Vitamin E is a supplement used to prevent or treat a lack of vitamin E in the body. A low body level of vitamin E is rare. Most people who eat a normal diet do not need extra vitamin E. However, vitamin E supplements are used in premature newborns and in people who have problems absorbing enough vitamin E from their diets. Vitamin E is important in protecting your body’s cells from damage. It is known as an antioxidant.

Vitamin E is available under the following different brand names: Aquasol E, alpha-tocopherol, and tocopherol.

 

Picture Credit : Google