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

Science & Technology, Defense, Environment

Major extinction event that wiped out around a third of marine species (Free Available)
Novel cancer drug delivery system using graphene oxide nanoparticles (Free Available)
NASA is launching a sounding rocket CHESS (Only for Online Coaching Members)
Researchers synthesised molecule that shows promise as an anticancer agent (Only for Online Coaching Members)

Major extinction event that wiped out around a third of marine species

Scientists have discovered a major extinction event that wiped out around a third of marine species and reduced their diversity by 55% between two to three million years ago.
The disappearance of a large part of the terrestrial megafauna such as the sabre-toothed cat and the mammoth during the Ice Age is well known.
The team investigated fossils of marine megafauna from the Pliocene and the Pleisto-cene epochs — 5.3 million to around 9,700 years B.C.
As many as 43% of sea turtle species were lost, along with 35% of sea birds and nine per cent of sharks.

Novel cancer drug delivery system using graphene oxide nanoparticles

Researchers at the Indian Institute of Science Education and Research (IISER) Pune have successfully developed a novel cancer drug delivery system using graphene oxide nanoparticles.
In a serendipitous discovery, a team led by Dr. Sudipta Basu and Dr. NirmalyaBhallav from the Department of Chemistry found that when a FDA-approved anticancer drug cisplatin was added, the graphene oxide sheets self-assembled into spherical nanoparticles enclosing the drug within.
Two DNA-damaging anticancer drugs — proflavine and doxorubicin — that bind to graphene oxide through non-covalent bond were also used.
The nanoparticles of 90-120 nanometre size containing cisplatin and either of the two anticancer drugs were taken up by cervical cancer cells leading to programmed cell death. The results were published in the journal Chemical Communication.
The cisplatin nanoparticles containing either proflavine or doxorubicin were found to get into the lysosomes of a cell in a time-dependent manner.
Once inside the lysosomes, the drugs were released in a slow and sustained manner and killed the cancer cells predominantly through programmed cell death.
In the case cisplatin nanoparticles containing proflavine, about 54% of proflavine was released in about 2 days while 22% of cisplatin was released after three days.
For cisplatin nanoparticles containing doxorubicin, more (33%) of cisplatin and less (22%) of doxorubicin were released after three days.
Though the study found that comparable concentration of doxorubicin and proflavine was required to kill 50% of the cells at the end of 48 hours, Dr. Basu prefers to use doxorubicin.

NASA is launching a sounding rocket CHESS

NASA is launching a sounding rocket CHESS on June 27 to study vast interstellar clouds and know about the earliest stages of star formation.
The Colorado High-resolution Echelle Stellar Spectrograph will measure light filtering through the interstellar medium, which provides crucial information for understanding the lifecycle of stars.
In the space between distant stars there drift vast clouds of neutral atoms and molecules, as well as charged plasma particles that may, over millions of years, evolve into new stars and even planets.
CHESS will train its eye at Beta Scorpii — a hot, brightly shining star in the Scorpius constellation well-positioned for the instrument to probe the material between the star and our own solar system.
This is the third flight for the CHESS payload in the past three years, and the most detailed survey yet.
Some IT experts identified the virus as “Petrwrap”, a modified version of the Petya ransomware which hit last year and demanded money from victims in exchange for the return of their data.
But global cybersecurity firm Kaspersky Lab said: “Our preliminary findings suggest that it is not a variant of Petya ransomware as publically reported, but a new ransomware that has not been seen before,” which it named “NotPetya”.
The cyberattack also recalled a ransomware outbreak last month which hit more than 150 countries and a total of more than 200,000 victims with the WannaCry ransomware.
Research from Florida Institute of Technology in the US, published in Geophysical Research Letters shows that lightning can be much more powerful over the ocean than land.
The new study validates for the first time through independent measurement previously formed beliefs that strikes over sea water tend to be more powerful.
It could inform how off-shore infrastructure and vessels are to be built to minimise the risk of super-powerful lightning bolts.
In their study, which measured peak currents of various cloud-to-ground lightning strikes over land and ocean from 2013 to 2015, researchers calculated the duration of the “negative stepped leader” — the electrical channel that moves down towards ground from a thundercloud.
When the leader touches ground, a surge of current, typically with a peak value of around 30 kilo amperes, flows upward to the cloud.
The durations of negative stepped leaders over the ocean were significantly shorter than those over land, indicating they carry more charge in them.

Researchers synthesised molecule that shows promise as an anticancer agent

Researchers at the Indian Institute of Science, Bengaluru, have synthesised a small molecule that shows a degree of promise as an anticancer agent.
In particular, the inhibitor was effective against leukaemia. The work was done in collaboration with researchers from the University of Mysore.
The molecule (a benzothiazole derivative), codenamed 5g, was found to be effective in inhibiting cell proliferation in both leukaemia and breast cancer cell lines.
This was achieved by arresting a particular phase (G2/M) of the cell cycle, thereby preventing cancer cells from dividing and growing in number.
But a small-scale study carried out on approximately 5,000 people living in 30 tribal villages in West Godavari district of Andhra Pradesh was able to improve the practice of seeking out mental health care significantly.
The intervention was carried out for three months from November 2015 to January 2016 by involving 21 ASHA workers and two primary health care doctors who were trained for about 10 days.
A mobile technology-based mental health service delivery model was used by ASHA workers and doctors for screening, diagnosing and treating people with common mental disorders such as depression, anxiety, suicide risk and stress.
Of the nearly 5,000 people who were screened, 238 were identified as being positive for common mental disorders and were referred to primary care doctors for treatment.
Thirty of the 238 people visited a primary care doctor for further diagnosis and treatment.
The percentage of people who sought mental health care shot up from 0.8% at the beginning of the intervention to 12.6% at the end of the three-month intervention period. The results were published in the Journal of Global Health.
Considering that there were not sufficient mental health professionals to treat all patients across the country, the study has been successful in training ASHA workers and PHC doctors to provide basic mental health care that included screening and providing treatment.
Prior to intervention, an anti-stigma campaign was carried out for three months. The campaign improved the awareness level and changed the attitude and behaviour related to mental health.