Three share Nobel for medicine

U.S.-British scientist John O’Keefe and Norwegian married couple May—Britt Moser and Edvard Moser won the Nobel Prize in medicine on Monday for discovering the brain’s positioning system.

This “inner GPS” helps explain how the brain creates “a map of the space surrounding us and how we can navigate our way through a complex environment,” the Nobel Assembly said.

O’Keefe, of University College London, discovered the first component of this positioning system in 1971 when he found that a certain type of nerve cell was always activated when a rat was at a certain place in a room.

Thirty--four years later May-Britt and Edvard Moser, of the Norwegian University of Science and Technology in Trondheim, identified another type of nerve cell that generates a coordinate system for precise path—finding, the assembly said.

It said that knowledge about the brain’s positioning system may “help us understand the mechamism underpinning the devastating spatial memory loss” that affects people with Alzheimer’s disease.

success

success

Giant leap,mom

THE precise and flawless manoeuvre with which the Indian Space Research Organisation’s (ISRO) Mars orbiter was eased into its designated orbit around the red planet has surprised even ISRO scientists. This is evidence of the meticulous preparation, checking, extensive simulations and ground-testing of all the on-board systems including the main thruster engine 440-Newton Liquid Apogee Motor (LAM), and the accuracy of the command algorithms and the associated software that has gone in to give the satellite complete on-board autonomy of operations in this crucial phase.

The achievement is even more remarkable because, notwithstanding its modest mission objectives and corresponding relatively small-sized spacecraft, such a complex mission was put together in just 18 months. The mission objectives required the development of 22 new software modules, modification of 42 modules and usage of 19 existing modules, a process that began only in November 2012 after the project was sanctioned in July.

This total autonomy was essential to the mission given the Earth-Mars distance of about 224 million kilometres at the time of Mars capture to a maximum of 375 million km after six months. This means there would be a communication delay of 25 to 42 minutes given the time that an electromagnetic signal will take for its round trip. So any real-time intervention would be impossible. Further, the geometry of Mars, the earth and the satellite during Mars Orbit Insertion (MOI) was such that the manoeuvre would have to be performed when there was an occultation of the satellite by the planet when the satellite would be out of visibility for ground systems and there would be a total communication blackout.Complete autonomy means that all the commands that are uploaded into the on-board computer are time-tagged and are sitting in the spacecraft’s command processor, and any major problem in the ground-to-satellite link will not affect the firing, pointed out K. Radhakrishnan, Chairman, ISRO. Spacecraft autonomy is also essential during the lifetime of the satellite because, as the satellite goes round in its Martian orbit, eclipses, whiteouts and blackouts will recur. “We essentially had a suitcase model of the satellite system on the ground and whatever operations are to be carried out in space have been performed and tested on the ground. The ground tests involved as many as 120 parameters,” Radhakrishnan said a week before the MOI firing, on September 24.

The final Martian orbit achieved by the MOI manoeuvre on September 24 has a 427-km periapsis (shortest distance from Mars) and a 76,993.6 km apoapsis (the farthest distance) as against the planned 423 km × 80,000 km orbit. “This is, in fact, a better orbit than what we had aimed for, because a smaller apoapsis orbit is more stable,” pointed out Koteswara Rao, ISRO’s Scientific Secretary. “But these orbit parameters are based on measurements on points on only a part of the orbit. We will have the exact parameters after it completes one full orbit,” he cautioned.

But, more significantly, the burn duration of the main thruster LAM during the MOI was reduced from the 24.14 minutes planned earlier to 23.15 seconds following the successful test of LAM firing on September 22 after the spacecraft had entered the sphere of influence (SOI) of Mars’ gravity. This test-firing, which was for a very short duration of four seconds, consuming only about 0.5 kilograms of the fuel, not only obviated the need for Plan B (which would have involved firing only the eight 22-N smaller thrusters for a longer duration) but also reduced the actual firing duration required for the MOI.

The final burn duration was only 23.08 seconds, a difference of nearly a minute from the planned duration. This duration is actually determined by the on-board accelerometer itself, which shuts off the engine automatically once the required change in velocity—actually a braking velocity to slow down the spacecraft to enable its capture into the Martian orbit—is realised. As against the targeted 1,098.7 m/s, the operation achieved a velocity change of 1,099 m/s. That is indeed an amazing precision. A difference of one minute in the burn time also means a significant gain in terms of the on-board fuel saved.

Before the MOI, the quantity of effectively available on-board fuel was 281 kg, of which about 250 kg was expected to be consumed during the LAM firing. But that difference of one minute has meant a fuel saving of about 10 kg and this can, in principle, increase the spacecraft life beyond the targeted six months. “We achieved a completely unexpected efficiency of 99.6 per cent in the LAM performance during the test firing,” Radhakrishnan said. “Normally, one does expect a performance degradation of about 2 per cent when you restart after leaving it idle for as long a duration as 300 days. Even our simulations had indicated that. But to our surprise, we got such high efficiency that we decided to reduce the burn time during the MOI,” he said. And even the final firing seems to have gone off with equal efficiencyThe idea of the September 22 test firing itself was quite innovative. It was actually a two-in-one operation: one to carry out a trajectory correction manoeuvre (TCM) of bringing the altitude of the final orbit down to the designated value of around 500 km from the 720-odd km that the spacecraft would have achieved if this firing had not succeeded and the spacecraft had gone along in its trajectory; two, to test the performance of the main engine for the crucial D-day operation. This TCM, which was otherwise scheduled to be carried out on September 14, was not done with this two-birds-with-one-stone operation in mind. You could argue that that there was a risk of not getting the correct altitude if the LAM had failed in the test. But, if the LAM had failed, in any case an optimum orbit with thrusters alone would not have been possible. So why not this? So went the scientists’ logic and it was indeed remarkable thinking. As Radhakrishnan pointed out, the most crucial firing for the orbiter was the Trans-Mars Injection (TMI) manoeuvre. At TMI, the route taken, with four TCMs using the small thrusters, was projected to take the spacecraft to about 500± (50-60) km away from Mars (the periapsis). The four TCMs that ISRO had originally planned were: TCM-1, which was performed on December 11, 2013; TCM-2 scheduled for April; TCM-3 for August and TCM-4 for September.

But ISRO did not have to do the TCM-2 in April because it was felt that the spacecraft trajectory was steady and did not need any correction at that time. TCM-2 was subsequently done on June 11. TCM-2 was also important from another perspective. Except for the engine itself, this manoeuvre had all other aspects involved in the MOI manoeuvre: reorienting the spacecraft, loss of telemetry, and so on. The question then was whether TCM-3 in August was required. It was found that there was no need for it because, without TCM-3, the trajectory was going to be about only 720 km away from Mars. Finally, TCM-4 was reconfigured to be a twin operation with the LAM itself instead of the thrusters. The success of TCM-2 already had given confidence to ISRO scientists that the MOI could be performed without any problem if LAM worked. And the modified TCM-4 proved that LAM will work more efficiently than they had imagined.

Providing a parallel circuit of flow lines for the propellants, a feature not used in other inter-planetary spacecraft—which may have been the reason for the high rate of failures in such missions—was really an innovative solution to a potentially serious problem. The ground test of the D-day firing with the propulsion parameters on D-day—the tank ullage volume, the pressure, the temperature, and so on—and with a new set of flow lines but with the main engine that had gone through some firings, had been conducted successfully for nearly 2,000 seconds, which was more than the targeted duration of about 1,500 seconds for actual firing. This test, which was done only in August, had also indicated that the engine should work after being idle for 10 months, giving the scientists added confidence in its success.

One of the important elements in propellant flow is the pressure in the fuel and oxidiser tanks. Basically, the pressure in the tanks should last the entire operation, MOI and the additional minor on-orbit corrections to the satellite later during its lifetimeThe pressure should not fall below a critical value of 11-12 bar. [One bar is about one atmospheric pressure.] There is a pressurisation system—including the pressurant tank (helium under very high pressure) and the two pressure regulators—sitting above the engine to regulate the pressure in the propellant tanks, which normally come into the pictures only if the pressure falls below 11 bar. But an unexpected leak in one of the pressure regulators required the pressurisation system to be completely isolated from the engine. This was a well-thought-out decision because the ground tests for full 2,000 seconds had shown that the engine performed well with the pressure (of about 16.5 bar) available in the tanks as measured before the test firing without requiring to bring the pressurisation system into play. Both the test burn and the MOI burn firing were therefore performed in the so-called “blow down” mode (in which the pressure is allowed to drop naturally as the engine consumes the propellant). The final pressure as measured after the MOI firing was 11.5 bar in the fuel tank and 12 bar in the oxidiser rank, which, according to Koteswara Rao, are more than optimum for the minor on-orbit corrections that will be required during the mission lifetime of six months.

Camera switched on

Only the on-board colour camera has been switched on now after MOM entered the Martian orbit. According to Radhakrishnan, these pictures have been compared with archived pictures taken from lower altitudes by the Mariner and Viking missions of NASA. “They compare well,” he said. The other instruments will be calibrated and checked over the next one week to 10 days one by one, according to Koteswara Rao. Science will begin after that with appropriate instruments being switched on when required, depending upon the altitude, illumination condition, and so on. “Our scientists are right now discussing what should be the schedule of operations for observing the comet Siding Spring on October 19,” said Radhakrishnan.

The success of the mission so far has proved beyond doubt ISRO’s capability in building reliable systems that can endure journeys of over hundreds of millions of kilometres in hostile space environment and its deep-space communication and navigation capabilities on inter-planetary scales. Innovation and ingenuity in the conceptualisation and designing of the on-board systems have also contributed greatly to the success. And to have been able to achieve this in its maiden attempt when other, more experienced, space-faring nations failed is indeed commendable. With this achievement, ISRO will command more respect in the world of space technology and industry

The distance to disarmament

The 1966 Nuclear Non-Proliferation Treaty remains on date the only agreement to prevent the spread of these weapons outside the original five nuclear weapons states.

The commemoration of the first International Day for the Total Elimination of Nuclear Weapons on September 26 was a moment for introspection. The Cold War is behind us and it is nearly 70 years since the catastrophe in Hiroshima and Nagasaki. Yet, why are nuclear arms the most contentious of all Weapons of Mass Destruction, and nuclear disarmament as distant as ever? The answers are not far to seek. The 1966 Nuclear Non-Proliferation Treaty remains on date the only agreement to prevent the spread of these weapons outside the original five nuclear weapons states. But then, there are more countries today that flaunt these terrible weapons as a symbol of military might and many more that are perhaps perilously close to their acquisition. This bleak history is a commentary on the discrimination inherent in the NPT. The treaty privileges the status quo; it obliges non-nuclear weapons states not to acquire nuclear weapons, without concomitant guarantees on disarmament from the Nuclear Weapons States (NWSs). The 1996 Comprehensive Nuclear Test Ban Treaty aims to prohibit all tests and explosions. A potentially crucial deal, it has yet to come into force because not all of the 44 countries with nuclear power reactors would ratify it. The big players in Asia’s geopolitics including India have kept out of it, as has Washington.

Formal negotiations to finalise a Fissile Material Cut-off Treaty have not commenced in all these decades. At issue has been the question whether such a deal should cover existing or future stockpiles of plutonium and highly enriched uranium needed to produce nuclear weapons. The refusal of many non-aligned countries to sign up to a deal that would exclude current stocks from its purview, in effect preserving the hegemony of the NWSs, seem unexceptionable. The 2010 New START (strategic arms reduction treaty) limits the U.S. and Russia to 1,550 strategic nuclear warheads deployed on 700 strategic delivery systems. This is the most current legally binding and verifiable bilateral arms control accord between Washington and Moscow. Meanwhile, the five nuclear weapons free zones in different regions across the globe have not been backed by unconditional assurances by the original five NWSs not to use force. Against this overall backdrop, the recent global ban on chemical and biological weapons — other categories of WMDs — offers the hope of securing a similar abolition in relation to nuclear weapons at some time in the future. Efforts at the UN Conference on Disarmament towards the conclusion of a treaty may be long-drawn. But the stakes for world peace were never greater than they are today.

Coverage of antenatal care in India has to be increased: WHO

''Antenatal care is very important for health workers to detect mothers with obesity or diabetes... both specific risks during pregnancy," says Dr. Flavia Bustreo, Assistant Director General at WHO.

In 2013, globally, preterm birth complications were responsible for 15 per cent (0.96 million) of deaths in children under five years of age. It is a leading cause of death in neonates (0-27 days after birth). According to WHO, about 15 million babies are born preterm (before 37 completed weeks of gestation) every year. Such births are seen both in the developed and developing countries.

India ranks first in the list of 10 countries that account for 60 per cent of all preterm births; the U.S. is ranked sixth in the list.

“India has little more than 50 per cent of antenatal care coverage. So in order to face the issue of premature births, low birth weight babies and stillbirths, the first aspect is to increase the coverage of antenatal care,” Dr. Flavia Bustreo, Assistant Director General at WHO told this Correspondent. “During antenatal care, health workers can detect whether progress of foetal growth is happening normally, pregnant mother’s nutrition is good or look out for any other complications.”

What is evident in the latest data is that across the world, nearly 30 per cent of maternal deaths are linked to indirect causes like gestational diabetes and obesity — especially among young mothers, and the influence of communicable diseases on maternal deaths.

“So antenatal care is very important as health workers can detect mothers who are obese or have diabetes. These are specific risks during pregnancy and should be given particular care,” Dr. Bustreo said. “This is not happening in India. India has to particularly care for mothers for what we call as pre-existing conditions.”

Pregnant mothers who have diabetes, are obese or have preeclampsia (high blood pressure) are less likely to complete full term and babies will be born with low birth weight. Therefore, antenatal care becomes all the more important.

Of course, babies who are born before full term can still survive as simple interventions and treatments are available. For instance, corticosteroid given to mothers before delivery can greatly facilitate the development of the babies’ lungs. It can also be given to babies soon after their birth in cases when delivery takes place even before the steroid can be given to pregnant mothers. The steroid greatly reduce the possibility of neonatal deaths. Similarly, kangaroo mother care can go a long way in keeping babies warm and improve their chances of survival.

More to do

“India has to still progress. What is available as special care facilities for babies that are low birth weight and premature are not sufficient in number. What I have seen happening is that some of the facilities in private hospitals have moved very fast especially in the cities. But when you come to rural areas in North India, this is something that is still missing,” Dr. Bustreo said. “So this leads to loss of babies who are born too early or born too small. This is part of India’s challenge.”

Within reach

While being critical of the shortcoming of the Indian government, she is still very optimistic. “Our latest data show that India is just an inch away from reaching the MDG4 (child morality) and MDG5 (maternal mortality) targets. [The current under-five mortality rate is 56 and should reach 42 before December 2015. The MMR is 190 and should drop to 140 before the end of next year.] It’s just a matter of the curve accelerating a little bit. I am hopeful that if the new government concentrates constructively on the challenges and focuses on the strengths of immunisation programme then India can achieve the MDG4 target,” she stressed.

One big challenge that stares the country in the face is the reach of antenatal care. According to the 2014 data, antenatal care in rural areas is about 50 per cent for more than one visit and about 10 per cent for more than four visits. The availability of skilled attendant at the time of delivery is only about 20 per cent in rural areas.

Yet, Dr. Bustreo remains confident. “These data are retrospect. We don’t measure them in real time. I can tell you some countries that have seen huge progress when they applied themselves to the task. For example, in the case of child mortality, we have seen annual rate of reduction of seven per cent, nine per cent and even 10 per cent in the case of Ethiopia, Rwanda and Malawi,” she said. “So if India applies specific measures, I am quite confident that it would really come close to meeting the goals and it would surprise everybody.”

Talking about the huge number of adolescent marriages and women’s role in the society and education, she noted that positive results can be obtained despite certain determinants that impact on maternal and child mortality taking a long time to change.

“What we are arguing at this juncture is that India can strengthen the provision of care so even if you have a young adolescent pregnant mother or if a pregnant mother is affected by gestational diabetes or is biologically not matured and delivers a preterm baby, she and the baby can be saved,” she noted. “Some determinants will take a generation to change but providing critical care will not take a generation.”

Nobel-winning physicist Martin Perl dies at 87

The Nobel Prize-winning physicist from Stanford University discovered a subatomic particle known as the tau lepton

Martin Perl, a Nobel Prize-winning physicist from Stanford University who discovered a subatomic particle known as the tau lepton, has died at age 87.

The university said the retired professor, one of two American scientists who shared the Nobel Prize for physics in 1995, died at Stanford Hospital on Tuesday.

At the time Perl discovered the tau lepton, many physicists doubted the particle that would turn out to be a heavyweight cousin of the electron existed. He eventually proved them wrong using a new kind of accelerator in which electrons and positrons course in opposite directions and collide.

“People wanted me to be cautious,” Mr. Perl recalled in a 2013 interview with Stanford staff. “We kept taking data, and the evidence kept coming in. Every month or so we would get another handful 10 to 20 of these funny events. I gave a lot of talks. There would be all sorts of objections. ... We eventually eliminated every other explanation.”

In a 1995 interview with The Associated Press, Mr. Perl acknowledged that while his research defied easy explanation, he hoped that understanding the building blocks of matter would lead to advancements in fields such as alternative energy.

“We’re trying to get to simplest ideas of matter and energy. That could lead in the end to things that would help all sorts of fields,” he said. “If you don’t do basic research, in the end you won’t have a foundation for other discoveries.”

Born in New York City to Polish-immigrant parents in 1927, Perl earned his Ph.D. at Columbia University while studying under Nobel-winning physicist Isidor Isaac Rabi. He worked at the University of Michigan until he came to Stanford in 1963 as its linear accelerator was being construction.

One of his four children, Joseph Perl, works as a software developer and researcher at the Stanford Linear Accelerator Centre. He said his father kept coming to work in the lab and to trade ideas with colleagues for years after his official retirement.

“It was the one place in the whole world to be, to do what he wanted to do,” Joseph Perl said. “He always advocated that you should look at what the crowd is doing and go in a different direction.”