Special Current Affair for IBPS Exams : Science & Technology Part - 3

Special Current Affair for IBPS Exam


Topic: Science & Technology

  • Bacteria can help Farmers Use less Potash
  • US Scientists Created frist Cloned Human Embryo
  • Hydrogen Sensor for Greater Safety
  • Peptide-based Delivery Platforms to cure Cancer
  • A New Type of Wheat developed to Increase Productivity
  • Camera with Compound eye-like Lenses
  • The Tibetan Plateau and the Indian Monsoon
  • IISC designed a New Concept of Vaccine Delivery System
  • Making more out of Pedal Power

Bacteria can help Farmers Use less Potash

Potash is one of the major nutrients required by all crops. There is no such source in India and the entire requirement of potassic fertilizer is met by imports and distributed to farmers at subsidised price eroding both the foreign exchange reserve and revenue.

Import

During the year 2011-12 India imported about 38 lakh tonnes of potassic fertilizers for supplying to farmers. One can imagine the spending by the Government apart from the expenditure to the farmers. Usually about 50-60 kg of potassium is recommended for a hectare of rice. Crops like sugarcane, banana, potato and tapioca require more potassium. As much as 200 kg of potassium is recommended per hectare of sugarcane. To supply this quantity of potassium, farmers have to apply 330 kg of Muriate of Potash which costs Rs. 5,450. But to our advantage Indian soils are naturally rich in potassium and there is a potash mobilizing bacterium to mobilize this native potassium for plant absorption. Potassium in soil exists in different forms but the crop can absorb what is present in soil solution only.

US Scientists Created frist Cloned Human Embryo

A group of US Scientists in second week of May 2013 declared that they have succeeded in creating a cloned human embryo using the technique that helped in developing the cloned sheep in 1996. The scientists took fifteen years to create the cloned embryo. The team of scientists developed the embryo using skin samples of a woman’s egg to develop an early cloned human embryo. Aim of this research is development of a source of stem cells not a baby. These can be helpful in repair of damage created after heart attack or brains of patients of Parkinson’s disease. Somatic Cell Nuclear transfer technique was used in development of the embryo and it is the same technique that was used for developing the Ship Dolly, the first cloned animal in 1996.

Hydrogen Sensor for Greater Safety

The use of liquid sodium as a coolant in fast breeder reactors has been made safer, thanks to a sensor — electrochemical hydrogen meter — developed by scientists at the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, off Chennai. The sensor has been thoroughly tested at IGCAR; it was also tested at the Phenix fast breeder reactor in France. “It was first tested in Phenix in 2009 for one year,” said T. Gnanasekaran, Raja Ramanna Fellow at the Chemistry Group, IGCAR. “Now another sensor has been installed a few days ago in one of the experimental sodium loops in Cadarache, France.” Liquid sodium metal, not water, is used for extracting heat from the extremely hot core (where nuclear fission takes place) of a breeder reactor. Aside from other properties, liquid sodium has excellent heat transfer properties compared with water. The liquid metal at about 550 degree C transfers the heat to water in the secondary circuit to generate steam; the steam eventually runs the turbine. Any large-scale mixing of sodium and steam should be prevented as it can lead to explosive events. The pressure on the sodium side is low (1 bar) as the liquid sodium is at an operating temperature of 550 degree C, well below the 883 degree C boiling point. However, at about 160 bar, the pressure on the steam side is very high. But all that separates sodium and steam is a thin (4-5 mm) ferretic steel tube through which steam flows. There is a possibility, even if remote, of tube failure. Steam, which is at a higher pressure than sodium, tends to leak into the coolant when the tube develops a leak. On reaction with sodium, hydrogen and sodium hydroxide are formed. Sodium hydroxide, which is a caustic material, further aggravates the problem. Due to its low melting point, sodium hydroxide turns into a molten material at the site of the crack causing further corrosion of the tube. “Continuous monitoring for any steam leak even at its inception is therefore extremely important,” he pointed out. Since the operating temperature of sodium is high, hydrogen and other reaction products get dissolved in it. Hence the presence of dissolved hydrogen in sodium is continuously monitored to detect the initiation of a leak. “If undetected at the micro and small leak stages, steam leaks can develop into a large leak and lead to explosive events,” Dr. Gnanasekaran pointed out.

Peptide-based Delivery Platforms to cure Cancer

Scientists at CSIR-Centre for Cellular and Molecular Biology (CCMB) invented peptide-based delivery platforms for targeting tumours. This can be helpful in curing Cancer. The scientists developed this platform by using bacterial fermentation to bind DNA or small interfering RNA (siRNA) or short hairpin RNA (shRNA) and delivering them into cells to target tumours.

Given that DNA, siRNA and shRNA are negatively-charged, they need carriers like recombinant proteins. The benefit of DNA or siRNA is that they help in silencing the targeted genes. For example, if the TF gene involved in new blood vessel formation is silenced, the tumour will degenerate. At CCMB, the scientists developed chimeric peptide by fusing three peptide modules to deliver DNA or shRNA for degenerating tumours. Chimeric proteins with varied functional properties can be obtained from any organism or a virus and produced in bacterial factories using standard practices of recombinant DNA method. The advantage of using chimeric proteins is that they could be changed to target different tumours. Scientists are making efforts to evolve peptide-based platform technology with other homing ligands recognising different targets.

A New Type of Wheat developed to Increase Productivity

British scientists developed a new type of wheat which could increase productivity by 30 percent. The last 15 years have registered little growth in the average wheat harvest from each acre in Britain. The Cambridge-based National Institute of Agricultural Botany combined an ancient ancestor of wheat with a modern variety to produce a new strain.

The scientists used cross-pollination and seed embryo transfer technology to transfer some of the resistance of the ancient ancestor of wheat into modern British varieties. The resulting crop turned out to be bigger and stronger than the current modern wheat varieties. Scientists will carry out more tests before it is harvested by farmers. This Scientific development ensures that the global food security demands of the next five decades can be met.

Camera with Compound eye-like Lenses

A digital camera that has a lens that very closely mimics the compound eye of arthropods in all respects — wide-angle field of view of nearly 160 degrees, low aberration, high sharpness of vision, and infinite depth of field — has been developed by a team of scientists led by Young Min Song from the University of Illinois at Urbana-Champaign, U.S. A paper on the invention is published today (May 2) in Nature. Compound eyes of arthropods are by default hemispherical and have multiple lenses; hence any camera lens that intends to mimic them should have the same shape and multiple lenses. Digital cameras available today have a planar sensor with a single lens. The biggest challenge the scientists faced was in developing such a hemispherical sensor that has multiple microlenses.

They took advantage of the recent developments in stretchable electronics to achieve this. Elastic microlenses that could be blown into a dome-shaped structure are formed from a moulded piece of rubber. An array of 16 by 16 microlenses is found in a small square area of nearly 15 mm by 15 mm. According to the authors, of the 256 microlenses present, only 180 form the “working components of the camera.” Each convex microlens is connected to the base layer by means of a supporting post. This makes a microlens to appear like a dome on top of a pillar. A perforated black matrix covers the interspaces between the microlenses to prevent any stray light from entering the imaging system.

A black flexible silicon base layer has photodetectors that are arranged in such a manner that they match the microlenses. The two layers — one containing the lenses and the other containing the photodetectors — are then bonded in such a manner that the photodiodes are at the “focal position” of the lenses. The bonding is done at the points where the lenses overlie the photodetectors. Since both layers are made of stretchable material and are bonded at the correct points, they can be elastically changed from a flat shape, in which they are fabricated, to a dome-shaped structure when it becomes a part of the camera. The dome-shaped structure of the lens mimics a compound eye. The authors stress that changing the shape from planar to hemisphere neither changes the optical alignment nor the optical and electrical.

The Tibetan Plateau and the Indian Monsoon

The Plateau heating correlated with monsoon rainfall but only in early and late season. To what extent does the Tibetan plateau influence the south-west monsoon? Some 130 years ago, Sir H.F. Blanford, Chief Reporter of the newly-established India Meteorological Department (IMD), noticed that more Himalayan snow cover during the preceding winter presaged a poor monsoon. On that basis, IMD began issuing the first monsoon forecasts from 1882. But monsoon prediction was not so easily done and remains a difficult problem to this day.

Years later, the established view came to be that the Himalayas acted on the monsoon in two ways. The Tibetan plateau, heated up during summer and thereby established an atmospheric circulation that was conducive for the monsoon.

The vast mountain range also acted as a tall barrier, preventing cold, dry air in the northern latitudes from entering the subcontinent and subduing the warm, moisture-laden winds from the oceans that drive the monsoon.
In a paper published in the journal Nature in 2010, William Boos and Zhiming Kuang of Harvard University in the U.S argued that the Himalayas’ role as a barrier was the crucial factor for the monsoon.
Using a general circulation model that simulated what happened in the atmosphere, they found that even if the Tibetan plateau did not exist, the monsoon would be unaffected provided the Himalayas and adjacent mountain ranges were there to prevent intrusion of northern air. That belt of low pressure sucked in moisture from the oceans, thus initiating the monsoon. The heating of the Tibetan plateau correlated well with rainfall over India from May 20 to June 15 when the monsoon was setting in. But then the correlation disappeared only to reappear again for rainfall between September 1 and October 15 when the monsoon was tailing off. “We don’t have a very good answer yet” about how the Tibetan plateau could be influencing the late stage of the monsoon, he said.

In an earlier paper, he and Dr. Molnar had noted that swings in the temperature of the tropical Pacific Ocean’s surface waters near the international dateline, known as the El Nino-Southern Oscillation (ENSO), also strongly influenced rainfall over central India and its west coast during the early and late phases of the monsoon. With the Tibetan heating and ENSO acting independently of each other, the two factors taken together could have predictive value for rainfall in the monsoon’s early and late phases.

IISC designed a New Concept of Vaccine Delivery System

The Indian Institute of Science (IISc) designed and successfully tested a new concept of needleless vaccine delivery system in the laboratory. IISc has become the only organization in the world that has developed such a device. The new device was the result of collaboration among the laboratory for hypersonic and shock wave, the department of aerospace engineering, and the microbiology and cell biology department of the Indian Institute of Science.

Typhoid vaccine was successfully delivered into mice in laboratory using the new technique. The device utilizes the instantaneous mechanical impulse produced by micro-blast waves to achieve delivery of vaccines into mice.

A negligible amount of chemical energy is used to generate the micro-blast wave inside a small disposable plastic tube. Since the depth of penetration of drug below the skin is not much, animals do not feel the pain during vaccine delivery. The trials on animals have proved that by using this device a lesser quantity of vaccines is sufficient to provide resistance to animals against in comparison to conventional methods. The new system is safe, economical and painless.

Making more out of Pedal Power

Nine out of every 20 households in India still use bicycles (Census 2011). This offers a great potential to tap vast amount of energy from these cycles. Atom, a lightweight bicycle generator, can power your mobile, lights or any electronic device via USB. It comes with a detachable rechargeable battery pack, meaning the stored energy can be used whenever and wherever you need it. “The Atom is designed to charge phones at 2.5 W at 14.5 km per hour, initiating the charging at 5 kmph with 0.75 W. The rate of power generation is dependent on speed, but we’ve designed the Atom to be fully functioning at moderate speeds. At this speed, devices charge at the same rate as if they were plugged into a computer, and conforms to USB 2.0 standards,” said Aaron Latzke, CTO of Siva Cycle and the brain behind the design of this device. That charge rate equates to 1 per cent for every 2 minutes on the cycle for a 1440 mAh battery, the likes of which powers an iPhone 5. For batteries with lesser capacity, it would therefore charge faster.