ScienceDaily 2

ScienceDaily (Aug. 26, 2010) — Pathogens make themselves feel at home in the human body, invading cells and living off the plentiful amenities on offer. However, researchers at the Max Planck Institute for Infection Biology, Berlin, together with colleagues at Harvard University, reveal an opposite strategy used to ensure infection success. Pathogens can actually delay their entry into cells to ensure their survival. Upon cell contact, bacteria trigger a local strengthening of the cellular skeleton with the aid of signalling molecules, allowing them to remain outside the cell. The researchers also show that this strategy, unknown until now, is used by certain intestinal pathogens as well.

The research appears in PLoS Biology, published by the Public Library of Science (Aug. 24, 2010).

Infection with the sexually transmitted bacterium Neisseria gonorrhoeae can lead to an inflammation of the urogenital tract, the uterus and ovaries. By means of thread-shaped proteins on its surface called pili, the bacterium attaches itself to the cell membrane. Once attached, the bacteria undergo rapid changes of their surface structure to avoid recognition by the host's immune system. Only during the later stages of infection will the pathogens penetrate cells and occasionally advance into deeper tissues to find further breeding ground.

Until now scientists were firmly focused on understanding the tricks used by these pathogens to enter cells. The results of the Berlin-based researchers suggest, however, that bacteria may spend as much effort in resisting cell entry. Host cells tend to generate tiny vesicles by which they transport bacteria inadvertently into the interior. The researchers have now shed some light on the signals which prevent the bacteria from being 'swallowed'. Upon fastening themselves to the cell surface, the bacteria induce a sequence of events that results in the strengthening of the cell skeleton directly beneath the point of attachment. The structural protein Actin is transported to attachment sites, where it forms a strong, supportive chain. In tandem, another structural protein Caveolin-1 and the signalling proteins VAV2 and RhoA are recruited to the cell membrane where they play a central role in effectively maintaining N. gonorrhoeae in the extracellular milieu.

Better outside than inside

These results have opened up new perspectives in understanding the course of infections: "For a long time it was thought that most pathogens strive to enter cells quickly. However, the opposite may be the case. It seems the bacteria prolong their extracellular existence in order to survive," declares Thomas F. Meyer of the Max Planck Institute of Infection Biology. By anchoring to the cell via pili proteins and assembling an underlying support skeleton, the pathogen is buffered against the often inhospitable conditions of the extracellular environment.

By extrapolating their findings to the intestinal bacteriaEscherichia coli, the scientists have indicated that the strategy of delaying entry into cells to ensure survival may be widespread among pathogens, possibly even the bacterial agents of meningitis and pneumonia. These newly discovered signalling pathways may therefore have exciting implications for the prevention of infection.

Programming 2

Computer scientists from the University of California, San Diego broke "the terabyte barrier" -- and a world record -- when they sorted more than one terabyte of data (1,000 gigabytes or 1 million megabytes) in just 60 seconds. During this 2010 "Sort Benchmark" competition -- the "World Cup of data sorting" -- the computer scientists from the UC San Diego Jacobs School of Engineering also tied a world record for fastest data sorting rate. They sorted one trillion data records in 172 minutes -- and did so using just a quarter of the computing resources of the other record holder.

Companies looking for trends, efficiencies and other competitive advantages have turned to the kind of heavy duty data sorting that requires the hardware muscle typical of data centers. The Internet has also created many scenarios where data sorting is critical. Advertisements on Facebook pages, custom recommendations on Amazon, and up-to-the-second search results on Google all result from sorting data sets as large as multiple petabytes. A petabyte is 1,000 terabytes.

"If a major corporation wants to run a query across all of their page views or products sold, that can require a sort across a multi-petabyte dataset and one that is growing by many gigabytes every day," said UC San Diego computer science professor Amin Vahdat, who led the project. "Companies are pushing the limit on how much data they can sort, and how fast. This is data analytics in real time," explained Vahdat. Better sort technologies are needed, however. In data centers, sorting is often the most pressing bottleneck in many higher-level activities, noted Vahdat who directs the Center for Networked Systems (CNS) at UC San Diego.

The two new world records from UC San Diego are among the 2010 results released recently on http://sortbenchmark.org -- a site run by the volunteer computer scientists from industry and academia who manage the competitions. The competitions provide benchmarks for data sorting and an interactive forum for researchers working to improve data sorting techniques.

World Records
The Indy Minute Sort and the Indy Gray Sort are the two data sorting world records the UC San Diego computer scientists won in 2010, the first year they entered the Sort Benchmark competition.

In the Indy Minute Sort, the researchers sorted 1.014 terabytes in one minute -- thus breaking the minute barrier for this terabyte sort for the first time.

"We've set our research agenda around how to make this better…and also on how to make it more general," said UC San Diego computer science PhD student Alex Rasmussen, the lead graduate student on the team.

The team also tied the world record for the Indy Gray Sort which measures sort rate per minute per 100 terabytes of data.

"We used one forth the number of computers as the previous record holder to achieve that same sort rate performance -- and thus one fourth the energy, and one fourth the cooling and data center real estate," said George Porter, a Research Scientist at the Center for Networked Systems at UC San Diego. The Center for Networked Systems is an affiliated Center of the California Institute for Telecommunications and Information Technology (Calit2).

Both world records are in the Indy category -- meaning that the systems were designed around the specific parameters of the Sort Benchmark competition. The team is looking to generalize their results for the Daytona competition and for use in the real world.

"Sorting is also an interesting proxy for a whole bunch of other data processing problems. Generally, sorting is a great way to measure how fast you can read a lot of data off a set of disks, do some basic processing on it, shuffle it around a network and write it to another set of disks," explained Rasmussen. "Sorting puts a lot of stress on the entire input/output subsystem, from the hard drives and the networking hardware to the operating system and application software."

Balanced Systems

The data sorting challenges the computer scientists took on are quite different from the modest sorting that anyone with off the shelf database software can do by comparing two tables. One of the big differences is that data in terabyte and petabyte sorts is well beyond the memory capacity of the computers doing the sorting.

In creating their heavy duty sorting system, the computer scientists designed for speed and balance. A balanced system is one in which computing resources like memory, storage and network bandwidth are fully utilized and as few resources as possible are wasted.

"Our system shows what's possible if you pay attention to efficiency -- and there is still plenty of room for improvement," said Vahdat, holder of the SAIC Chair in Engineering in the Department of Computer Science and Engineering at UC San Diego. "We asked ourselves, 'What does it mean to build a balanced system where we are not wasting any system resources in carrying out high end computation?'" said Vahdat. "If you are idling your processors or not using all your RAM, you're burning energy and losing efficiency." For example, memory often uses as much or more energy than processors, but the energy consumed by memory gets less attention.

To break the terabyte barrier for the Indy Minute Sort, the computer science researchers built a system made up of 52 computer nodes. Each node is a commodity server with two quad-core processors, 24 gigabytes (GB) memory and sixteen 500 GB disks -- all inter-connected by a Cisco Nexus 5020 switch. Cisco donated the switches as a part of their research engagement with the UC San Diego Center for Networked Systems. The compute cluster is hosted at Calit2.

To win the Indy Gray Sort, the computer science researchers sorted one trillion records in 10,318 seconds (about 172 minutes), yielding their world-record tying data sorting rate of 0.582 terabytes per minute per 100 terabytes of data. The winning sort system is made up of 47 computer nodes similar to those used in the minute sort.

According to wolframalpha.com, 100 terabytes of data is roughly equivalent to 4,000 single-layer Blu-Ray discs, 21,000 single-layer DVDs, 12,000 dual-layer DVDs or 142,248 CDs (assuming CDs are 703 MB).

Info from http://www.sciencedaily.com/

Technology 2

The loneliness of the long-distance robot: A Cornell University robot named Ranger walked 14.3 miles in about 11 hours, setting an unofficial world record at Cornell's Barton Hall early on July 6. A human -- armed with nothing more than a standard remote control for toys -- steered the untethered robot.

Ranger navigated 108.5 times around the indoor track in Cornell's Barton Hall -- about 212 meters per lap, and made about 70,000 steps before it had a stop and recharge.

The 14.3-mile record beats the former world record set by Boston Dynamics' BigDog, which had claimed the record at 12.8 miles.

A group of engineering students, led by Andy Ruina, Cornell professor of theoretical and applied mechanics, announced the robotic record at the Dynamic Walking 2010 meeting on July 9, in Cambridge, Mass. Ruina leads the Biorobotics and Locomotion Laboratory at Cornell. The National Science Foundation funds this research.

Previously, students in Ruina's lab set a record for an untethered walking robot in April 2008, when Ranger strode about 5.6 miles around the Barton Hall. Boston Dynamics' BigDog subsequently beat that record.

One goal for robotic research is to show off the machine's energy efficiency. Unlike other walking robots that use motors to control every movement, the Ranger appears more relaxed and in a way emulates human walking, using gravity and momentum to help swing its legs forward.

Standing still, the robot looks a bit like a tall sawhorse and its gait suggests a human on crutches, alternately swinging forward two outside legs and then two inside ones. There are no knees, but its feet can flip up -- and out of the way, while it swings its legs -- so that the robot can finish its step.

Ruina says that this record not only advances robotics, but helps undergraduate students learn about the mechanics of walking. The information could be applied to rehabilitation, prosthetics for humans and improving athletic performance.

Info from http://www.sciencedaily.com/

ScienceDaily 1

Astronomers using NASA's Hubble Space Telescope have confirmed the existence of a baked object that could be called a "cometary planet." The gas giant planet, named HD 209458b, is orbiting so close to its star that its heated atmosphere is escaping into space.

Observations taken with Hubble's Cosmic Origins Spectrograph (COS) suggest powerful stellar winds are sweeping the cast-off atmospheric material behind the scorched planet and shaping it into a comet-like tail.

"Since 2003 scientists have theorized the lost mass is being pushed back into a tail, and they have even calculated what it looks like," said astronomer Jeffrey Linsky of the University of Colorado in Boulder, leader of the COS study. "We think we have the best observational evidence to support that theory. We have measured gas coming off the planet at specific speeds, some coming toward Earth. The most likely interpretation is that we have measured the velocity of material in a tail."

The planet, located 153 light-years from Earth, weighs slightly less than Jupiter but orbits 100 times closer to its star than the Jovian giant. The roasted planet zips around its star in a short 3.5 days. In contrast, our solar system's fastest planet, Mercury, orbits the Sun in 88 days. The extrasolar planet is one of the most intensely scrutinized, because it is the first of the few known alien worlds that can be seen passing in front of, or transiting, its star. Linsky and his team used COS to analyze the planet's atmosphere during transiting events. During a transit, astronomers study the structure and chemical makeup of a planet's atmosphere by sampling the starlight that passes through it. The dip in starlight because of the planet's passage, excluding the atmosphere, is very small, only about 1.5 percent. When the atmosphere is added, the dip jumps to 8 percent, indicating a bloated atmosphere.

COS detected the heavy elements carbon and silicon in the planet's super-hot, 2,000-degree-Fahrenheit atmosphere. This detection revealed the parent star is heating the entire atmosphere, dredging up the heavier elements and allowing them to escape the planet.

The COS data also showed the material leaving the planet was not all traveling at the same speed. "We found gas escaping at high velocities, with a large amount of this gas flowing toward us at 22,000 miles per hour," Linsky said. "This large gas flow is likely gas swept up by the stellar wind to form the comet-like tail trailing the planet."

Hubble's newest spectrograph has the ability to probe a planet's chemistry at ultraviolet wavelengths not accessible to ground-based telescopes. COS is proving to be an important instrument for probing the atmospheres of "hot Jupiters" like HD 209458b.

Another Hubble instrument, the Space Telescope Imaging Spectrograph (STIS), observed the planet in 2003. The STIS data showed an active, evaporating atmosphere, and a comet-tail-like structure was suggested as a possibility. But STIS wasn't able to obtain the spectroscopic detail necessary to show a tail, or an Earthward-moving component of the gas, during transits. The tail was detected for the first time because of the unique combination of very high ultraviolet sensitivity and good spectral resolution provided by COS.

Although this extreme planet is being roasted by its star, it won't be destroyed anytime soon. "It will take about a trillion years for the planet to evaporate," Linsky said.

Info from http://www.sciencedaily.com/

The results appeared in the July 10 issue of The Astrophysical Journal.

Technology

Hello Technology! as well! I also like technology as well as science and programming. Technology is important for human life, from breadmakers to computers. Do you see how important technology is? Without technology life would be dull. Technology is lots of things, including electric blankets as well! And a final Bye Technology! to finish off the post!

Science

Hello Science! As some of you know I am a fan of science as well as programming. I have been reading science books since Grade 1 and whenever I get a chance to buy books, I usually never miss it! Now I'm on the top of the class! I like astronomy and chemistry mostly, because I like star gazing and creating formulas and potions. In fact, one day I will be a famous scientist. I will also notify you of the latest science news if possible.Bye Science! for now!

Programming

Hello World! I am starting a domain with my dad and he's an IT ( Information Technology ) Manager so I will need his help to learn how to create a domain. The programming language we are using is PHP and we will be doing it on Linux ( Ubuntu ). The server we are using is the Apache Web Server, with MySQL as the database. If you have a Windows you can use WAMP Server and on Linux you can use LAMP Server. Any tips would be most appreciated. I will notify you when the real thing starts. Right now I am thinking of a name for our domain. Bye World! for now!