Type: Prelims Only

After seven months, the use of social media was allowed in Jammu and Kashmir with an order laying down the latest rules for the use of the Internet in the UT.  Among various conditions, the order says Internet connectivity will be made available “with mac-binding”.

What is Mac-binding?

• Every device has a Media Access Control (MAC) address, a hardware identification number that is unique to it. While accessing the Internet, every device is assigned an IP address.
• Mac-binding essentially means binding together the MAC and IP addresses, so that all requests from that IP address are served only by the computer having that particular MAC address.
• In effect, it means that if the IP address or the MAC address changes, the device can no longer access the Internet.
• Also, monitoring authorities can trace the specific system from which a particular online activity was carried out.

Permitted connections

• The Internet can be accessed on all postpaid devices, and those using Local Area Networks (LAN).
• While the postpaid SIM card holders shall continue to be provided access to the Internet, these services shall not be made available on prepaid SIM cards unless verified as per the norms applicable for postpaid connections.
• Apart from this, special access terminals provided by the government will continue to run.
• It is further directed that the access/communication facilities provided by the government, viz. e-terminals/Internet kiosks apart from special arrangements for tourists, students, traders etc shall continue.

Only 2G permitted

• Internet speed in J&K is still restricted to 2G.
• This means very slow services — pictures will take a long time to be sent or downloaded, videos will be nearly impossible to share, and there will be a long loading time for most websites.
• It also means that although in theory, the “whitelist system” — where people could only access some websites pre-approved by the government — has been removed, some sites designed for a 4G Internet experience will hardly work.

Have curbs been lifted?

• Not exactly. The latest order is to remain in force till March 17 unless modified earlier.
• The government has been relaxing Internet and phone usage in the UTs in phases.

Men outnumbered women by 37 million in the 2011 Census of India, but among those over the age of 60, there were more than 1 million more women than men. In general, men live shorter lives than women worldwide. This is due to the chromosomal differences between the two, points’ new study.

What are Chromosomes?

• The human body is made up of cells, and in the centre of each cell is the nucleus. Chromosomes, which are located inside the nucleus, are structures that hold the genes.
• It is the genes that determine the various traits of an individual including eye colour, blood type — and sex.
• The human cell has 23 pairs of chromosomes. One pair is of the sex chromosomes, named X and Y, which determine whether an individual is male or female.
• A female has two X chromosomes (XX) while a male has one X and one Y (XY).

Unguarded X hypothesis

• This hypothesis suggests that the Y chromosome in XY is less able to to protect an individual from harmful genes expressed on the X chromosome.
• In a male, as the Y chromosome is smaller than the X chromosome, it is unable to “hide” an X chromosome that carries harmful mutations, which may later expose the individual to health threats.
• On the other hand, the hypothesis goes, there is no such problem in a pair of X chromosomes (XX) in a female.
• If one of the X chromosomes has genes that have suffered mutations, then the other X chromosome, which is healthy, can stand in for the first, so that the harmful genes are not expressed.
• This maximizes the length of life, according to the hypothesis. And this is what the UNSW researchers set out to examine.

Testing the hypothesis

• In a statement issued by UNSW, PhD student and study first author Zoe Xirocostas said the
• Unguarded X hypothesis appears to stack up, after examining the lifespan data available on a wide range of animal species.
• Researchers studied lifespan data in not just primates but mammals and birds, but also reptiles, fish, amphibians, arachnids, cockroaches, grasshoppers, beetles, butterflies and moths among others.
• It was found that across that broad range of species, the heterogametic sex (XY in humans) does tend to die earlier than the homogametic sex (XX in humans).

Researchers at Tel Aviv University have discovered a non-oxygen breathing animal, which significantly changes one of science’s assumptions about the animal world — that all animals use aerobic respiration and therefore, oxygen.

Henneguya Salminicola

• The organism is Henneguya salminicola, a fewer-than-10-celled microscopic parasite that lives in salmon muscle.
• It relies on anaerobic respiration (through which cells extract energy without using oxygen).
• In the case of this non-oxygen breathing organism, evolution turned it into a simpler organism that shed “unnecessary genes” responsible for aerobic respiration.
• Other organisms such as fungi and amoebas that are found in anaerobic environments lost the ability to breathe over time.
• The new study shows that the same can happen in the case of animals, too.

What is Aerobic respiration?

• Animals, including humans, need energy to perform the various tasks that are essential for survival.
• Aerobic respiration is one such chemical reaction through which organisms take in oxygen and release carbon dioxide into the atmosphere.
• Through this mechanism, energy is transferred to cells, which can use it for multiple purposes — for instance, to burn food.
• Mitochondria is the “powerhouse” of the cell, which captures oxygen to make energy — its absence in the H. salminicola genome indicates that the parasite does not breathe oxygen.