Scientists isolate genes that delay Alzheimer's disease
Olga Deacon, who has dementia, speaks with her granddaughter, Chris Boyce, in a replica 1940s kitchen, at The Easton Home in Easton, Pa. - Photo: AP
A team of researchers have identified a network of nine genes that play a key role in the onset of Alzheimer’s disease and these findings could help scientists develop new treatments to delay the onset of the disease in a study of a family of 5,000 people in Columbia, scientists identified genes that delayed the disease and others that accelerated it, and by how much.
Arcos-Burgos at the John Curtin School of Medical Research said that if they could work out how to decelerate the disease, then they could have a profound impact.
Mr.Burgos said that it would be more successful to delay the onset of the disease than to prevent it completely, adding that even if they delay the onset by on average one year, that would mean nine million fewer people will have the disease in 2050.
Burgos and his team studied the variable age of onset of dementia in this family and with the cooperation of the family, the team were able to discount environmental factors and trace their genetic predisposition to Alzheimer’s Disease back to a founder mutation in one individual who came to the region about 500 years ago.
The team was able to isolate the nine genes involved in Alzheimer’s, some of which delay the onset by up to 17 years, while others advance its progress.
The study is published in the Journal Molecular Psychiatry.
Small indoor gardens may benefit cancer patients: study
Tending small indoor gardens may instill feelings of positivity, control and meaning in cancer patients, a new study suggests. The benefits of health nature-based activities are well-known; many programmes encourage cancer patients to tend gardens to improve psychological health. But gardens are not always accessible, particularly for cancer patients who are frail or disadvantaged.
Researchers led by Dr Ceri Phelps of the University of Wales Trinity Saint David in Wales tested a simpler, smaller approach - accessible, cheap, and not prone to whims of weather. Seven women from an existing breast cancer support group cultivated and customised their own indoor ‘garden bowls’ for three months. They started with a bowl, compost and three starter plants, which they took home and tended daily. The women reported on their feelings and findings in diary entries, collected within the research paper. “I think it doesn’t matter whether you’ve just been diagnosed or whether it’s been ten years down the road-it could be beneficial. The garden bowl could help you deal with whatever you have left behind,” said one of the patients while reflecting her bowl. The women felt that the process of tending the bowl and reflecting upon it led to feelings of positivity, control and meaning.
"The take-home message is that psychosocial interventions do not have to be complex, labour-intensive to deliver, or costly,” said Ceri Phelps of the University of Wales who led the study.
The study was published in the journal ecancermedicalscience.
Global diet is getting sweeter: study
The Hindu
Consuming foods and beverages with added caloric sweeteners is linked to an increased risk of weight gain .Photo:R Ragu
The global diet is getting sweeter, particularly when it comes to beverages, a trend that could negatively impact global health, researchers have warned. Previous research has shown that consuming foods and beverages with added caloric sweeteners is linked to an increased risk of weight gain, heart disease, diabetes and stroke.
Currently, 68 per cent of packaged foods and beverages in US contain caloric sweeteners, 74 per cent include both caloric and low-calorie sweeteners, and just 5 per cent are made with low-calorie sweeteners only.
The added sugar comes from hundreds of different versions of sugar, all of which have the same equal health effect, according to Barry M Popkin, from the University of North Carolina in US. He expects that in the absence of intervention, the rest of the world will move towards a similar pervasiveness of added sugars in the entire packaged food and beverage supply, with added sugars of all kinds increasing rapidly in the diets of people living in developing countries, while many high-ncome countries, despite being among the highest sugar consumers, are beginning to see a slight decline in sugar consumption. After analysing nutritional datasets from around the world, the researchers, including Corinna Hawkes from the City University London in UK, found that trends in sales of sugar-sweetened beverages around the world are increasing in terms of calories sold per person per day and volume sold per person per day.
“Consumption is rising fastest in low-and middle-income countries in Latin America, the Caribbean, Africa, the Middle East, Asia and Oceania,” the researchers said.
“The four regions with the current highest consumption are Latin America, North America, Australasia and Western Europe, though intakes are beginning to decline in the latter three,” they said.
Due to the major health risks, particularly weight gain and increased risk of diabetes, hypertension and many cardiovascular problems associated with added caloric sweetener consumption, the World Health Organisation (WHO) is promoting major initiatives to reduce intake. Many governments have already implemented policies with this goal, including taxation, reduction of availability in schools, restrictions on marketing of sugary foods to children, public awareness campaigns and front-of-pack labelling, the researchers said. While the latest data show that many countries consume high levels of sugar-sweetened beverages, and other countries with lower intakes are seeing steep increases, the authors did find that consumption seems to be decreasing in countries with taxes on such products (eg Mexico, Finland, Hungary and France).
The study was published in The Lancet Diabetes and Endocrinology journal.
Tuesday, 1 December 2015
Of free fall space cubes & waves
Elizabeth Gibney, Nov 24, 2015, The New York Times
There is a lot riding on the LISA Pathfinder mission, an ambitious effort to test whether intricate technology designed to detect ripples in space-time can be deployed in space. Scheduled to launch on December 2, the spacecraft is a long-awaited test-drive for a future one billion-euro ($1.1 billion) space observatory planned by the European Space Agency (ESA). The follow-up mission would track the largest objects in the Universe, including mergers between supermassive black holes and collisions between galaxies, by the space-time ripples that they create.
First predicted by Albert Einstein almost exactly 100 years ago as part of his general theory of relativity, such gravitational waves have never been observed directly — let alone used to study the cosmos. There are already Earth-based observatories hunting these waves, but a space-based one would search for waves at the opposite end of the spectrum. “It’s like having a radio telescope as well as an optical one,” says Karsten Danzmann, director of the Max Planck Institute for Gravitational Physics in Hanover, Germany, and co-principal investigator for the Pathfinder mission. “The part of the Universe you see is completely different.”
The final space-based observatory will try to spot the stretching and compressing of space by bouncing laser beams between three masses floating in free fall, each separated from the others by some five million kilometres (3.1 million miles). Because the masses would be protected from all other external forces, only a gravitational wave should disrupt the synchrony of their falling motion — a disturbance that would affect laser frequency.
The LISA Pathfinder (named after the Laser Interferometer Space Antenna, the concept behind the gravitational-wave observatory) is a smaller-scale test of this ultimate plan. With a price tag of 400 million euros ($426.2 million), it uses just two masses — each a two-kilogram (4.4-pound) cube of gold and platinum — separated by a mere 38 centimetres (15 inches), which allows them to fit inside the same spacecraft.
Unlike that of the observatory that it is designed to test-drive, this setup is not sensitive enough to detect gravitational waves — instead, its purpose is to show that the masses can be completely isolated, and that any deviations in their relative motion can be measured with picometre accuracy. “We’re missing out the five million kilometres, but so what?” says Paul McNamara, the mission’s project scientist. “Pretty much everything that could affect our ability to measure gravitational waves is here.”
From the time of Pathfinder’s launch from ESA’s spaceport in Kourou, French Guiana, to the end of its subsequent eight-week journey, the masses will stay pinned to their housing deep inside the craft. But on arrival in orbit around a stable point between the Sun and Earth called Lagrange point 1, or L-1, about 1.5 million kilometres (.9 million miles) away, the cubes will be gently released to float within the spacecraft.
Once in free fall, “the challenge is to isolate this little cube from everything around it, so the only thing it sees is space-time,” says Paul. Expected disturbances are pressure from solar radiation and stray magnetic fields; the equipment is so precise that it should detect even a force equal to the weight of a small bacterium on Earth.
As a high-precision laboratory in space, the LISA Pathfinder is unlike anything that ESA has done before, says Tim Sumner, an astrophysicist at Imperial College, London who led the team that constructed one of the craft’s protection mechanisms.
Another unusual element is that the major cargo — the cubes — will define the craft’s trajectory, rather than vice versa. As they orbit around L-1 and fall in microgravity, Pathfinder will deploy microthrusters that are so gentle, it would take around 1,000 to lift a piece of paper on Earth. The thrusters will monitor the cubes’ positions, ensuring that the craft hovers around the cubes without letting them touch its sides. Such a setup required the teams who built the instruments and the engineers who made the craft to work together to an unprecedented degree, says Tim. These complexities go a long way toward explaining why the launch has taken so long to orchestrate, says Stefano Vitale, a physicist at the University of Trento in Italy, and a principal investigator for the Pathfinder mission; Pathfinder was approved by ESA in 2000 and originally intended for launch in 2006. “Coarsely speaking, I think people underestimated the difficulty,” says Stefano. “But that’s why you have a Pathfinder.”
The final step in the planned mission will test Pathfinder’s limits by instructing onboard instruments to tweak the internal temperature and magnetic and electrostatic fields to see how such changes affect the cubes. “We want to learn everything we can about the physics of a free-floating body, and everything we learn will feed back into design of the future mission,” says Paul.
However, some opportunistic ESA scientists are already thinking about how Pathfinder’s instruments could be used to inform other problems once its main mission, which could take up to a year, is complete. Measurement of the gravitational constant, known as Big G, for example, should fall naturally out of Pathfinder’s data, Tim says. Because the true value of Big G is disputed, a fresh measurement from space would provide useful perspective.
To get a higher precision measurement, ESA may also consider extending the mission — although Tim says that scientists would only request this after Pathfinder has proved itself, a few months in. He and his colleagues have also discussed using the craft’s thrusters to send it to a spot known as a saddle point, where the gravitational pulls of Earth and the Sun cancel each other out. This could reveal how gravity behaves at its lowest level possible in the solar system, with little extra cost. Few scientists doubt that Einstein’s theories hold, says Tim, but it would be interesting to do the test nonetheless.
Stefano, however, points out that it is important for researchers to stay focused on the mission’s immediate goal. “Our main objective is to demonstrate free fall,” he says, “and we don’t want to be distracted from that.”
SNIPPETS-Identifying gender from a fingerprint
Sindya N Bhanoo Dec 1, 2015, The New York Times
A simple test performed at a crime scene may help forensic scientists determine whether a fingerprint belongs to a man or a woman, a new study reports. The test is based on certain amino acids found in the fingerprints. Levels are twice as high in the sweat of women as in that of men.
“Fingerprints have really been treated as pictures for more than a hundred years,” said Jan Halamek, a forensic scientist at the State University of New York at Albany and one of the study’s authors. “The only major improvements in recent years have been due to software and databases that make it faster to match fingerprints.”
Regardless of the surface type, they found it was possible to tell whether the fingerprint belonged to a woman by testing levels of residual amino acids. The report was published in the journal Analytical Chemistry. The study involved only a few fingerprints, however, and a larger sample is required to ensure the results are statistically significant, Jan said.
He and his colleagues are developing additional fingerprint tests based on protein markers found in blood samples. “We want to create a very simple kit which can determine on the spot whether the person was young or old, male or female, and their ethnicity,” Jan said. These tests, he cautioned, could not replace DNA tests, which are reliable but also time-consuming and expensive.
Astrobiological impacts of neutrinos
This year’s Physics Nobel Prize for the discovery of neutrino oscillations implies that at least one of the three neutrino species has a tiny mass, possibly of the order of one or a few electron volts. Individual neutrino masses are yet to be accurately ascertained. But the oscillations measure is the mass difference squared, i.e., for two species 1 and 2 or more, it is precisely the product of the mass difference squared and the mixing angle.
For instance, independent cosmological evidence from the Wilkinson Microwave Anisotropy Probe (WMAP) suggests that the sum total of the masses is about an electron volt. Other experiments suggest a few electron volts. As each neutrino has a corresponding antineutrino, there are totally six types of neutrinos.
Now, neutrinos are expected to have been produced profusely in the very initial stages of the universe, i.e., during the Big Bang. Similar to the microwave background which is the fossil remnant of the high energy radiation, which characterised the hot dense phase of the earlier epoch, we also expect a fossil remnant of neutrinos, which now form a background with an estimated density of about 150 per cubic centimetre, per species. So, in summation, from all the six species we expect a fossil neutrino background with a number density of 1,000 per cubic centimetre.
So, if each neutrino had a mass of about even 20 electron volts, this would imply that the Universe would have a density much greater than the closure density and would have collapsed several billion years ago. But a universe where a neutrino had a 50 electron volt rest mass would definitely not have had much of a chance to develop biological life, let alone support advanced forms of evolved life.
Since at present, we do not have a definitive understanding of neutrino masses, one wonders whether there can be some anthropic requirement for low masses. Neutrinos are known to be produced prodigiously in a Type-2 supernova, where a massive star collapses after its iron core can no longer continue to produce thermonuclear energy.
A supernova occurring 10 light years away would produce 10 billion neutrino captures in a kiloton detector and each of us would capture one lakh high energy neutrinos, which could potentially cause DNA cell damage. The captured neutrinos would produce damaging gamma rays, high energy neutrons, among other elements. So, life on potential planets neighbouring massive star associations, (or stellar systems) like OB associations could be severely constrained.
The mystery of antimatter
Palahalli R Vishwanath Dec 1, 2015,
The discovery of a particle with curious properties in August 1932 was probably the first time a piece of antimatter was found in nature. At that time, a particle detector called cloud chamber, where an incoming particle would leave a trail of drops was being used to record particles. In the presence of a magnetic field, particles would curve in opposite directions depending on their charge. Carl Andersen, a physicist from Caltech in the USA, when working with cosmic rays, found a track in the cloud chamber which was opposite in direction to the ones caused by the electron. Carl called it a positron which seemed to be very similar to the electron except for the charge.
This particle had been actually anticipated by the scientific community. In 1897, J J Thomson discovered the electron, a negative charged particle. In 1928, the great theorist Paul Dirac published the famous Dirac equation, which allowed electrons to have both positive charge and negative energy. While for sometime, he thought that proton could be that particle, three years later he predicted the particle would be an antielectron with all qualities same as electron but with a positive charge. Paul and Carl and got the Nobel Prize for the prediction and the discovery in 1933 and 1936, respectively. Thus, it was accepted that all particles should have antiparticles.
A fundamental concept In the postulation and discovery of the positron, physicists were enunciating a fundamental concept that equal amount of matter and antimatter should be present in the Universe. Paul had also postulated that when matter and antimatter combine, they would annihilate each other, resulting in the creation of energy which would present itself in the form of high energy photons like gamma rays.
The energy of one of the first big particle accelerators Bevatron was tuned specifically to produce antiprotons. It started functioning in 1954. After one year of the experiment, and sifting through nearly two million particle events, the group had detected 38 particles with same mass as proton but with negative charge. This research also fetched the Nobel Prize for the discovery of antiproton.
Neutral particles also have antiparticles. For example, neutron and antineutron have differing signs for their magnetic moment. Just as hydrogen atom has a proton in the centre and an electron in the outer ring, antihydrogen atom would have antiproton in the centre and a positron in the outer ring.
The preponderance of matter over antimatter has been a mystery of nature. If these had been in the same proportion, the Universe, as we know, would not have come into existence. Somewhere in the initial stages of the Big Bang, due to certain processes, we have an asymmetric universe. However, there is the possibility that there are some regions of the Universe where antimatter dominates. Thus, how much antimatter exists is one of the fundamental questions of the origin and nature of the Universe. Another important question is about the possible difference between matter and antimatter. There have been two interesting experiments addressing these questions in the last few months.
First is the AMS (Alpha Magnetic Spectrometer) experiment located on the International Space Station, which looks for primary antiprotons in cosmic rays. Its aim, according to its spokesman, Nobel Prize winner Samuel Ting, is “to search for phenomena that so far we have not had the imagination or the technology to discover!” The standard picture is that antiprotons are produced in collisions of cosmic ray protons with nuclei in interstellar matter. New results from the experiment presented in mid-April disagree with current models of antiproton production.
The ratio of antiprotons to protons has been obtained across a wide energy range and the experiment finds that this proportion does not decrease at higher energies as predicted, but stays almost constant. Earlier, the same group had found an anomalous result for the proportion of positrons to electrons, a higher fraction than expected, but it could be invoking conventional physics. The authors believe that dark matter could be producing these antiprotons but only more data can give a better understanding of the results.
The second experiment seeks to find possible differences between matter and antimatter. While they can differ, for example, in the way they decay, other fundamental properties, such as the absolute value of their electric charges and masses are predicted to be exactly equal. It is with this aim that an experiment called Baryon Antibaryon Symmetry Experiment (BASE) conducted in CERN laboratory in Geneva started some time ago. The experiment looks for precise comparison of the charge-to-mass ratio of the proton to that of the antiproton.
The new result, the result of an intense 35-day experiment with 13,000 measurements, shows no difference between the proton and the antiproton. They state, “We found that the charge-to-mass ratio is identical to 69 parts per thousand billion, supporting a fundamental symmetry between matter and antimatter.”
Any difference between the charge-to-mass ratio of protons and antiprotons, however small, would break a fundamental symmetry law, a difference that would constitute a dramatic challenge to the basic concepts of particle physics.
Taking the right measure of stress
Karen Weintraub Dec 1, 2015, The New York Times
Research has long shown that stress is bad for you, but many people are not even aware when they are feeling stressed. Now, a number of new devices are sold as stress trackers, measuring signs of stress the way fitness tracking devices monitor steps and movement. The gadgets track the biological symptoms of stress — changes in skin perspiration, breathing patterns and heart rate — in hopes of helping people become aware of their stress levels.
Tracking stress One of them is Spire, a stone-like device that clips to a belt or bra and senses the expansion and contraction of the chest cavity during breathing. The device sends phone notifications when it detects a change in breathing patterns that may indicate stress. “Your breathing suggests you’re stressed,” it says. “Take a deep breath.”
The Pip stress manager uses electrical changes at the surface of the skin to measure an individual’s stress response. The user holds the teardrop-shaped device between the thumb and forefinger and the device collects data and analyses it with charts and graphs that monitor stress on a given day or across weeks or months to find patterns, such as what time of day is most stressful for you.
The downside of most devices is that while breathing patterns and skin sweat certainly can signal stress, they can also indicate a range of emotions and activities. Physiologically, there is not much difference between the stress of a work deadline and the excitement of watching your favourite sports team. Even going for a brisk walk stimulates a similar response from the sympathetic nervous system, which runs the body’s fight or flight mechanism. The same thing occurs in certain stages of sleep.
Most apps and devices that claim to track or reduce stress lack scientific rigour, said Rosalind Picard, a professor at the Massachusetts Institute of Technology’s Media Lab, who straps stress monitors onto the wrists of visitors to her Cambridge office. It is hard to objectively determine someone’s stress in the real world — accounting for individual variation, diets, lifestyles, medication and other environmental factors, Rosalind said, adding, “If you want to learn about human variability, measure stress.”
But that has not stopped Rosalind from trying. She is chief scientist at Empatica, which will soon release its Embrace watch. It takes stress monitoring a step further than most by tracking skin temperature, movement, sleep, respiration, heart rate, heart rate variability and skin conductance, a measure of electrical charge that reflects changes in arousal. The watch vibrates when it detects a rising stress level. The device is also designed to alert people with epilepsy of an impending seizure.
Neumitra, a start-up based in Boston, is scheduled to release a watch-like stress tracker early next year, but has not released pricing details. The device, said the company’s chief executive, Robert Goldberg, will turn people into “citizen scientists,” feeding the tracker’s algorithm to make it smarter about what’s causing their arousal. If someone consistently shows signs of stress when heading to a particular client’s office or when driving on the highway, the tracker may link them to their favourite tunes or lead them through breathing exercises to help reduce their stress. Rosalind said she has worked with teachers who changed their approach when stress monitors showed their students’ anxiety triggers.
One father had a long conversation with his son when a monitor repeatedly showed the boy felt more anxious around him. And Rosalind said she changed her own response to Boston traffic after an earlier version of her tracking device showed her how much she was letting other drivers get to her. “I am a much more relaxed driver now,” she said.
Researchers at Microsoft in Redmond, Washington, are testing how to deliver useful stress reduction tips. In one month-long study, participants were instructed to do positive activities on their phone, like going to their Facebook timeline and looking for three people, objects or events they are thankful for.
“Maybe what you need to do is teach people a little bit and get out of their way,” said Mary Czerwinski, who is leading that study and is a research manager at Microsoft. “And maybe after a couple of months, if their stress levels are going up, maybe pop back in and remind them of what it was.”
Not liked by everyone But sometimes telling a person that he or she is stressed may end up just causing more stress. Mary once worked with a study volunteer who got upset when tracking devices indicated that he was stressed. “No machine can know when I’m stressed better than I know I’m stressed,” the volunteer said angrily.
Some device makers are working to incorporate stress reduction into the device itself. Thync Inc. of Boston and Los Gatos, California, makes a headset that uses nerve stimulation that claims to “recharge your mood,” provide calm, focus and energy, and promote sleep. The device creates an electrical circuit between the right temple and the back of the neck, modulating nerves on the head, face and neck, which are involved in sensory processing and mood. One level of stimulation is designed to reduce stress; a different level can reportedly stir feelings of bliss.
The only studies showing Thync’s success have come from the company itself, which has tested the device in about 4,000 people, said Jamie Tyler, co-founder and the chief science officer.
Rosalind and Mary said they remained sceptical that any currently available device could act on the body to reduce stress. Instead, Rosalind said she prefers a low-tech way of responding to her own anxiety: She gets up and goes for a short walk. “It’s not only less expensive” than any device, she said, “but it’s probably better for my whole body, not just my brain.”
