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Mars Base

July 16 - Today in Science History - Scientists born on July 16th, died, and events - 0 views

www.todayinsci.com/...7_16.htm

scibyte136 LookingBackJul

shared by Mars Base on 15 Jul 14 - No Cached
  • Shoemaker-Levy Comet
  • In 1994, the first of 21 asteroids, major fragments of the comet Shoemaker-Levy 9 broken-up 2 years earlier, hit Jupiter, creating a 1200-mile wide fireball 600 miles high to the joy of astronomers awaiting the celestial fireworks, giving scientists their first chance to observe such a collision as it happened, and others through July 22. Jupiter is a gas giant, made up mostly of hydrogen and helium in gas and liquid form.When we observe Jupiter, we are looking not at a solid surface, but a banded atmosphere with swirling clouds and huge storms
Mars Base

July 17 - Today in Science History - Scientists born on July 17th, died, and events - 0 views

www.todayinsci.com/...7_17.htm

scibyte136 LookingBackJul

shared by Mars Base on 15 Jul 14 - No Cached
  • Earliest Record Solar Eclipse
  • In 709 BC, the earliest record of a confirmed total solar eclipse was written in China. From: Ch'un-ch'iu, book I: "Duke Huan, 3rd year, 7th month, day jen-ch'en, the first day (of the month). The Sun was eclipsed and it was total." This is the earliest direct allusion to a complete obscuration of the Sun in any civilisation. The recorded date, when reduced to the Julian calendar, agrees exactly with that of a computed solar eclipse. Reference to the same eclipse appears in the Han-shu ('History of the Former Han Dynasty') (Chinese, 1st century AD): "...the eclipse threaded centrally through the Sun; above and below it was yellow." Earlier Chinese writings that refer to an eclipse do so without noting totality.
Mars Base

SpaceX Launches Six Commercial Satellites on Falcon 9; Landing Test Ends in "Kaboom" - 0 views

www.universetoday.com/...-9-landing-test-ends-in-kaboom

scibyte136 SpaceX

shared by Mars Base on 15 Jul 14 - No Cached
  • SpaceX successfully launched six ORBCOMM advanced telecommunications satellites into orbit on Monday, July 14, to significantly upgrade the speed and capacity of their existing data relay network.
  • SpaceX also used this launch opportunity to try and test the reusability of the Falcon 9′s first stage and its landing system while splashing down in the ocean
  • However, the booster did not survive the splashdown. SpaceX CEO Elon Musk reported that the rocket booster reentry, landing burn and leg deployment worked well, the hull of the first stage “lost integrity right after splashdown
  • ...5 more annotations...
  • Musk tweeted. “Detailed review of rocket telemetry needed to tell if due to initial splashdown or subsequent tip over and body slam.”
  • SpaceX wanted to test the “flyback” ability to the rocket, slowing down the descent of the rocket with thrusters and deploying the landing legs for future launches so the first stage can be re-used
  • The previous test of the landing system was successful, but the choppy seas destroyed the stage and prevented recovery
  • the six satellites launched
  • are the first part of what the company hopes will be a 17-satellite constellation. They hope to have all 17 satellites in orbit by the end of the 2014
Mars Base

July 20 - Today in Science History - Scientists born on July 20th, died, and events - 0 views

www.todayinsci.com/...7_20.htm

scibyte136 LookingBackJul

shared by Mars Base on 15 Jul 14 - No Cached
  • Mars landing
  • In 1976, America's "Viking I Lander" spacecraft, launched 20 Aug 1975, made its successful, first-ever landing on Mars at Chryse Planitia, and began transmitting pictures. Later, a robot arm that could scoop up samples of material and deposit them into on-board experiments, investigated the hint of life on Mars. Both weathered top soil and deeper soil samples were tested. The image shows Chryse Planitia looking NW over the Viking 1 Lander. An antenna is at upper right. The wide, low plain is covered with large rocks, loose sand and dust. The image was taken on 30 August 1976, a little over a month after landing. Pictures from the mission included views of the Mars surface taken from the Viking 1 Orbiter from space.
Mars Base

'Mississippi Baby' now has detectable HIV, researchers find -- ScienceDaily - 0 views

www.sciencedaily.com/...140710151951.htm

scibyte136 AIDS

shared by Mars Base on 12 Jul 14 - No Cached
  • The child known as the 'Mississippi baby' -- an infant seemingly cured of HIV that was reported as a case study of a prolonged remission of HIV infection
  • now has detectable levels of HIV after more than two years of not taking antiretroviral therapy without evidence of virus
  • an infant seemingly cured of HIV that was reported as a case study of a prolonged remission of HIV infection
  • ...24 more annotations...
  • now has detectable levels of HIV after more than two years of not taking antiretroviral therapy without evidence of virus
  • "Scientifically, this development reminds us that we still have much more to learn about the intricacies of HIV infection and where the virus hides in the body. The NIH remains committed to moving forward with research on a cure for HIV infection."
  • NIAID Director Anthony S. Fauci, M.D.
  • The researchers planning the clinical trial will now need to take this new development into account
  • The child was born prematurely in a Mississippi clinic in 2010 to an HIV-infected mother who did not receive antiretroviral medication during pregnancy and was not diagnosed with HIV infection until the time of delivery
  • Because of the high risk of HIV exposure, the infant was started at 30 hours of age on liquid, triple-drug antiretroviral treatment.
  • Testing confirmed within several days that the baby had been infected with HIV. At two weeks of age, the baby was discharged from the hospital and continued on liquid antiretroviral therapy
  • The baby continued on antiretroviral treatment until 18 months of age, when the child was lost to follow up and no longer received treatment
  • when the child was again seen by medical staff five months later, blood samples revealed undetectable HIV levels (less than 20 copies of HIV per milliliter of blood (copies/mL)) and no HIV-specific antibodies
  • The child continued to do well in the absence of antiretroviral medicines and was free of detectable HIV for more than two years
  • Repeat viral load blood testing performed 72 hours later confirmed this finding
  • Additionally, the child had decreased levels of
  • a key component of a normal immune system, and the presence of HIV antibodies
  • Based on these results, the child was again started on antiretroviral therapy
  • To date, the child is tolerating the medication with no side effects and treatment is decreasing virus levels
  • Genetic sequencing of the virus indicated that the child's HIV infection was the same strain acquired from the mother
  • In light of the new findings, researchers must now work to better understand what enabled the child to remain off treatment for more than two years without detectable virus or measurable immunologic response
  • what might be done to extend the period of sustained HIV remission in the absence of antiretroviral therapy
  • "Typically, when treatment is stopped, HIV levels rebound within weeks, not years."
  • "The prolonged lack of viral rebound, in the absence of HIV-specific immune responses, suggests that the very early therapy not only kept this child clinically well, but also restricted the number of cells harboring HIV infection," said Katherine Luzuriaga, M.D., professor of molecular medicine, pediatrics and medicine at the University of Massachusetts
  • The case
  • indicates that early antiretroviral treatment in this HIV-infected infant did not completely eliminate the reservoir of HIV-infected cells that was established upon infection
  • may have considerably limited its development and averted the need for antiretroviral medication over a considerable period
  • during a routine clinical care visit earlier this month, the child, now nearly 4 years of age, was found to have detectable HIV levels in the blood
Mars Base

The 1% of scientific publishing | Science/AAAS | News - 0 views

news.sciencemag.org/...1-scientific-publishing

scibyte136

shared by Mars Base on 15 Jul 14 - No Cached
  • But these
  • scientists dominate the research journals, having their names on 41% of all papers.
  • The new research, published on 9 July in PLOS ONE, was led by epidemiologist John Ioannidis of Stanford University in Palo Alto, California, with analysis of Elsevier’s Scopus database by colleagues Kevin Boyack and Richard Klavans at SciTech Strategies
  • ...14 more annotations...
  • They looked at papers published between 1996 and 2011 by 15 million scientists worldwide in many disciplines
  • The ranks of scientists who repeatedly published more than one paper per year thin out dramatically
  • Two or more: 68,221
  • Three or more: 37,953
  • Four or more: 23,342
  • Five or more: 15,464
  • 10 or more: 3269
  • Many of these prolific scientists are likely the heads of laboratories or research groups; they bring in funding, supervise research, and add their names to the numerous papers that result
  • Others may be scientists with enough job security and time to do copious research themselves
  • there’s also a lot of grunt work behind these papers
  • from highly productive labs
  • doctoral students may be enrolled in high numbers, offering a cheap workforce
  • may spend years on research that yields
  • only one or a few papers
Mars Base

Sun sends more 'tsunami waves' to Voyager 1 - 0 views

phys.org/...14-07-sun-tsunami-voyager.html

scibyte136 Voyager1

shared by Mars Base on 12 Jul 14 - No Cached
  • NASA's Voyager 1 spacecraft has experienced a new "tsunami wave" from the sun as it sails through interstellar space
  • Such waves are what led scientists to the conclusion, in the fall of 2013, that Voyager had indeed left our sun's bubble, entering a new frontier
  • "Normally, interstellar space is like a quiet lake,
  • ...15 more annotations...
  • Ed Stone of the California Institute of Technology
  • But when our sun has a burst, it sends a shock wave outward that reaches Voyager about a year later. The wave causes the plasma surrounding the spacecraft to sing."
  • Data from this newest tsunami wave generated by our sun confirm that Voyager is in interstellar space
  • The mission has not left the solar system—it has yet to reach a final halo of comets surrounding our sun—but it broke through the wind-blown bubble, or heliosphere, encasing our sun
  • ur sun goes through periods of increased activity, where it explosively ejects material from its surface, flinging it outward
  • These events, called coronal mass ejections, generate shock, or pressure, waves. Three such waves have reached Voyager 1 since it entered interstellar space in 2012
  • The first was too small to be noticed when it occurred and was only discovered later, but the second was clearly registered by the spacecraft's cosmic ray instrument in March of 2013
  • another instrument on Voyager
  • The plasma wave instrument can detect oscillations of the plasma electrons
  • This ringing of the plasma bell is what led to the key evidence showing Voyager had entered interstellar space
  • "The tsunami wave rings the plasma like a bell," said Stone. "While the plasma wave instrument lets us measure the frequency of this ringing, the cosmic ray instrument reveals what struck the bell—the shock wave from the sun."
  • denser plasma oscillates faster, the team was able to figure out the density of the plasma
  • In 2013, thanks to the second tsunami wave, the team acquired evidence that Voyager had been flying for more than a year through plasma that was 40 times denser than measured before—a telltale indicator of interstellar space
  • Now, the team has new readings from a third wave from the sun, first registered in March of this year
  • These data show that the density of the plasma is similar to what was measured previously, confirming the spacecraft is in interstellar space
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