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Eight years and 34 million miles on, Mars rover nears end of road
Gene therapy shown to destroy leukemia tumours
Prof Yash
Pa
THIS UNIVERSE
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Eight years and 34 million miles on, Mars rover nears end of road
It travelled at an average speed of 60cm an hour and it has arrived a year late. But the Mars rover Opportunity is finally approaching its destination, the rim of the vast Endeavour crater. Nasa hailed the six-wheel Opportunity’s approach to the 22.5km-wide crater last night as a “tremendous scientific success”. The ageing robotic field geologist has logged more than 32km since it was first parachuted on to the planet’s surface in 2003, along with its twin rover Spirit, for a planned three-month mission after their 34 million-mile journey from Earth. Spirit emitted its last signal a year ago after becoming trapped in sand. Opportunity crawled out from a crater in 2008 and headed south to the Endeavour, a two-year journey in theory, which has taken longer because Opportunity had to drive backwards to prevent its front wheel from wearing out. At the crater, Opportunity will travel south across the rim to perform a geological assessment of the location, examining the clay minerals formed under wet conditions at the oldest of the four craters it has visited. The finishing point was nicknamed Spirit Point in honour of Opportunity’s fallen twin. Scott Maxwell, leader of the Mars Rover driving team, tweeted: “The drive we uplink today will actually take us physically on to Cape York. So. Excited.” Project manager John Callas, of the Nasa Jet Propulsion Laboratory, said that reaching the Endeavour crater was an important science target: “We will likely spend years at this location. It’s not just one spot. There’s kilometres of interesting geology to explore.” Endeavour is more than 25 times wider than the Victoria crater, an earlier stop that the rover examined for two years. Nasa believes Endeavour is much older. The minerals and sediments had only been viewed at a distance. Mr Callas said: “It represents geology from very early in Mars history. It’s understanding what happened to Mars a long time ago.” Both rovers have made important discoveries about wet environments on ancient Mars. Scientists now know that Mars was at one time like Earth, with an atmosphere thick enough to support liquid water which may have been favourable for microbial life. Mr Callas said the Spirit rover also found evidence of ancient hydrothermal systems on Mars that could support an ecosystem. He said the Opportunity was still in good health despite some “arthritis” in its joints, adding: “We’re on the surface of a planet that’s hundreds of millions of kilometres away in frigid cold temperatures.” —The Independent
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Gene therapy shown to destroy leukemia tumours
Scientists for the first time have used gene therapy to successfully destroy cancer tumours in patients with advanced disease—a goal that has taken 20 years to achieve.
Researchers at the University of Pennsylvania engineered patients’ own pathogen-fighting T-cells to target a molecule found on the surface of leukemia cells. The altered T-cells were grown outside of the body and infused back into patients suffering from late-stage chronic lymphocytic leukemia (CLL), which affects the blood and bone marrow and is the most common form of leukemia. Two participants in the Phase I trial have been in remission for up to a year. A third had a strong anti-tumour response, and his cancer remains in check. The research group plans to treat four more patients with CLL before moving into a larger Phase II trial. “We put a key onto the surface of the T-cells that fits into a lock that only the cancer cells have,” said Dr. Michael Kalos, director of translational and correlative studies at the University of Pennsylvania’s Perelman School of Medicine and an investigator on the study. The results provide “a tumour-attack roadmap for the treatment of other cancers,” including those of the lung and ovaries as well as myeloma and melanoma, researchers said. The findings were published simultaneously on Wednesday in the New England Journal of Medicine and Science Translational Medicine. Kalos said past efforts to use the technique, known as “adoptive T-cell transfer,” failed either because the T-cell response was too weak or proved too toxic for normal tissue. The technique differs from other cancer therapies designed to harness the body’s own immune system to fight tumours—such as therapeutic cancer vaccines. “We are saying forget about stimulating an immune response. We are going to give you an immune response,” Kalos said. The treatment appears safe, but researchers said more study was needed. The leukemia patients in the Phase I trial had to be treated with an immunity-boosting drug since the targeted molecule, CD-19, is also present on certain normal immune-system cells. To deliver the gene therapy, the researchers used a virus that can only infect cells once. It was used to carry a chimeric antigen receptor targeting CD-19 coupled with receptors for two other components of T-cell activity. About two weeks after the gene therapy, patients began to experience “tumor lysis syndrome”—chills, nausea and fever — caused by the break-down products of dying cancer cells. The engineered T-cells were detected in patients’ blood for several months afterward, and a portion of them turned into “memory T-cells,” which could provide ongoing protection against cancer recurrence, researchers surmised. — Reuters
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Genetic clues to multiple sclerosis unravelled
LONDON: Scientists have found 29 new genetic variants linked to multiple sclerosis (MS) and say the findings should help drug makers focus treatment research on precise areas of the immune system. In a study published in the journal Nature on Wednesday, researchers said the newly-found links point to the idea that T-cells—a type of white blood cell responsible for mounting an immune response—and chemicals called interleukins play a key role in the development of the debilitating disease. LONDON: Releasing genetically modified, spermless male mosquitoes into the wild could in future help to prevent malaria transmission and reduce the chances of large outbreaks of the killer disease, British scientists said on Monday. Researchers from Imperial College London sterilized male mosquitoes by genetically modifying them to neutralize a gene required for sperm production. Orange goo washing ashore in Alaska is egg mass ANCHORAGE, Alaska: A mysterious orange goo that washed ashore in an Alaska village last week and sparked pollution concerns turns out to be a mass of crustacean eggs or embryos, government scientists said on Monday. Tests of a sample sent by the Alaska Department of Environmental Conservation produced the results, officials at a laboratory belonging to the National Oceanic and Atmospheric Administration’s Alaska Fisheries Service Center said. —Reuters |
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THIS UNIVERSE
We often hear about cloudbursts. However, rain still comes down in drops and not as if from a faucet. Why is it so?
The use of the word cloudburst gives the impression that in a thick large cloud, water collects as in a lake or a dam. The "cloudburst" then suggests the breaking up of the dam that pours down all its water on a city already soggy with water. This is a picturesque way of describing extremely heavy downpours often encountered during the Monsoon season. No, there is no storage of water in the atmosphere after it becomes a liquid. Gravity will not allow it a rest period. It has to start its descent towards the earth surface. This phase of the drama could involve adventure and transformations. Tiny droplets might freeze when they meet a cold front. Tiny crystals might congregate to form large snowflakes. Snow flakes might float down to the surface in cold parts of the earth, including mountain peaks and over log periods form glaciers that inch down to feed rivers and oceans either as melted water or as icebergs — or they night lie there and accumulate over millions of years into kilometers thick coverings of the earth in the polar regions of the planet. In tropical regions the snowflakes melt before reaching lower atmosphere and forget that they had started their journey down like fairies. They just become spherical raindrops. It does come happen occasionally that tiny droplets freeze into super cooled balls of ice that get layers of ice on their journey down and turn into large hailstones that damage crops and occasionally cause more grievous damage . Finally, if production of each drop of rain is an autonomous act by a small part of the cloud, how come there is a synchrony among these small parts ranging over long distances. I believe this is because the convection zones have a large size and also because the rate at which the temperature decreases with altitude is also the same.
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