Blogcritics

Announcement: Short-content feeds

Phillip Winn — Sun, 26 Aug 2007 12:00:00 EDT

Sunday, August 26, 2007, marks the switch of all Blogcritics.org article feeds from full-content to short-content. This is the result of several converging factors, and is unfortunately a permanent decision (as permanent as any decision can be on the web, that is). We are aware of all of the reasons that this is a Bad Idea, and we are aware that some of you will be quite upset about having to click on something to read the free content, and we're sorry. Unfortunately, despite great effort, full-content feeds are not currently economically viable. Two other factors are involved: full-content feeds have resulted in an unprecedented level of content theft, with BC content appearing on many websites, usually spam sites, without attribution or permission. This duplicate content causes a cascading set of problems, not the least of which is that search engines generally aren't favorable to duplicate content, and don't always guess correctly. Finally, our RSS advertising partner is strongly in favor of short-content feeds. We hope that you'll continue to subscribe to BC via RSS, and when an article grabs your eye, it's only a click away, still free on the BC website. Thank you for your understanding.

Enzyme Removes HIV from Cells

John Vaccaro — Sat, 30 Jun 2007 14:50:02 EDT

A study published in the June 29 issue of the magazine Science provides the first evidence that Human Immunodeficiency Virus (HIV) can be fought by removing HIV's DNA from infected cells. A group of German scientists have created a mutant strain of a well-known enzyme that acts as a pair of scissors to "snip out" HIV's DNA sequence that was previously inserted into the larger human cell DNA as part of an HIV infection.What makes HIV so insidious is that it insinuates its own DNA into that of the host cell. HIV's DNA hijacks the cell's reproductive mechanism to produce more of the HIV virus. When that host cell divides more of the HIV virus is produced. Current treatments for HIV focus on the use of anti-viral drugs to suppress the HIV virus before it enters cells. The German researchers, Indrani Sarkar, Ilona Hauber, Joachim Hauber, and Frank Buchholz of the Max Planck Institute for Molecular Cell Biology and Genetics and the University of Hamburg's Heinrich Pette Institute for Experimental Virology and Immunology created a variant of the Cre recombinase enzyme, know as Tre. Cre looks for specific sites, designated lox P, on a cell's DNA which indicate the beginning and end of a section of DNA. The Cre enzyme destroys those sites causing the DNA segment to be severed from the rest of the cell's DNA. The Tre enzyme was created by exposing Cre to the HIV virus and allowing Cre to evolve into an enzyme that can detect a segment of HIV DNA in a cell's strand of DNA.While this is a very promising line of research, much work remains to be done to make this an effective treatment for HIV. Enzymes such as Cre/Tre are notoriously hard to introduce into the body without the body's natural processes destroying them. Further, this study was conducted on only one species of HIV, HIV-1. It remains to be seen if this enzyme will be equally effective on the other species of HIV, HIV2. Lastly, Tre is a very slow-acting enzyme. In the experiments conducted by Sarkar, et al, Tre required three months to remove all traces of HIV from cultured human cervical cells.Alan Engelman, a molecular virologist at the Dana-Farber Cancer Institute in Boston wrote an accompanying editorial in the same issue of Science. "This is the first demonstration of actual removal of the integrated virus from cells. The results are promising," he says, "but researchers have to make sure the slow-acting Tre enzyme works on real-world strains of HIV and figure out how to safely and precisely administer it in gene form to give it time to snip."Ideally, Engelman wrote, researchers would like to find a way to send Tre enzymes into the small number of white blood cells, known as T cells, that carry the virus without producing new viral particles, which allows HIV to hide from both antiviral drugs and the immune system.

John Vaccaro is a senior technologist with a wide spectrum of experience in science and information technology. He has worked in the marketing automation, speciality polymers, healthcare and financial services areas and has extensive experience with open source software in an international business environment.

Review Board Reports on Mars Orbiter Loss

John Vaccaro — Sun, 22 Apr 2007 18:51:24 EDT

The Mars Global Surveyor (MGS) spacecraft unexpectedly lost radio contact in November, 2006. When attempts to reconnect with MGS were unsuccessful, NASA convened an internal review board. The board was formed to determine why NASA's Mars Global Surveyor went silent and to make recommendations about any processes or procedures changes that could increase safety for other spacecraft.The results of the internal review board were published on April 13th, 2007. The root cause of the spacecraft loss was complete discharge of the spacecraft's batteries. When a command was sent to MGS on November 2nd, 2006 to reorient its solar panels, the spacecraft transmitted a series of alarms, followed by a message indicating MGS had stabilized. This was the last message the MGS ground controllers received from the spacecraft.Investigators now believe that although the spacecraft indicated it was in a stable position, in reality it had oriented itself into a position that exposed one of its two batteries to direct sunlight. The unrelenting sunlight caused the battery to overheat and fail leading to the depletion of the second battery. The programmed attitude MGS was to assume in case of a problem was not a thermally safe orientation. The spacecraft's antenna was not aimed at Earth so the spacecraft could not communicate its status or accept commands. Eleven hours later the battery system depleted completely. These failures were traced back to a software update transmitted to MGS in June of 2006. The directions for pointing the spacecraft antenna in case of a problem on board the spacecraft were written to the wrong memory address in MGS's computer. When the November 2nd command was received by MGS it triggered a sequence of events that resulted in the loss of power to the spacecraft.The internal review board findings were made in three key areas: Operational Procedures and Processes, Spacecraft Design Weaknesses and Lifetime Management Considerations. The processes and procedures were inadequately written, providing no guidance for the errors that occurred. The spacecraft's on board fault protection was insufficient to handle the faults that were most likely encountered. Finally, the risk for errors was increased by the staff and other cost reductions made to the MGS Mission as it entered its fourth extended mission phase.The full text of the Interim Report is available NASA's web site.

Very Little Arctic Thick Sea Ice Replenished in 2005

John Vaccaro — Sat, 21 Apr 2007 17:20:05 EDT

A NASA study released in early April has found that very little of the thick sea ice in the Arctic has been replaced during the perennial melt/freeze cycle the Arctic undergoes. The replenishment of the sea ice is critical to maintaining a stable covering of ice during the Arctic summer season. These findings reinforce earlier data from NASA that indicated a 14 percent drop in perennial ice between 2004 and 2005.The perennial ice coverage in the Arctic falls due to summer melting and transport of ice out of the Arctic. Perennial ice is typically ten or more feet thick while seasonal ice is much thinner. The seasonal ice replaces the lost perennial ice, but must survive an entire summer season to become part of the perennial ice cover. If none of the seasonal ice survives then previously ice-covered areas may become open water."Recent studies indicate Arctic perennial ice is declining seven to 10 percent each decade," explained Ron Kwok of NASA's Jet Propulsion Laboratory in Pasadena, California. "Our study gives the first reliable estimates of how perennial ice replenishment varies each year at the end of summer. The amount of first-year ice that survives the summer directly influences how thick the ice cover will be at the start of the next melt season."Using data from NASA's QuikScat satellite and other sources, data on six annual cycles of perennial Arctic ice were studied. The QuikScat satellite uses radar pulses reflected off Arctic ice to inventory both perennial and first-year ices. After the 2005 summer melt only about four percent of the 965,000 square miles of seasonal ice that formed the previous winter survived the summer and replenished the perennial ice cover. Additionally, weather conditions in the Arctic created winds that pushed ice out of the Arctic at an increased rate. Perennial ice that moves out of the Arctic in the summer time leaves open-water areas behind that absorb more heat than ice cover would and do not refreeze until summer's end. The increased heat absorption leads to additional thinning of the ice cover.These findings suggest that the amount of first-year ice that survives is related to the number of freezing temperature days during the prior season. More freezing temperature days increases the ice thickness, making it more likely to survive the summer heating. "The winters and summers before fall 2005 were unusually warm," Kwok said. "The low replenishment seen in 2005 is potentially a cumulative effect of these trends."When the six years of data were examined within the larger context of longer-term temperature records dating back to 1958, Kwok found a gradual warming trend in the first 30 years, which accelerated after the mid-1980s. Additionally, there was no data to indicate any reversal of the warming trend. "The record doesn't show any hint of recovery from these trends," he stated. "If the correlations between replenishment area and numbers of freezing and melting temperature days hold long-term, it's expected the perennial ice coverage will continue to decline."This study suggests that on average the area of seasonal ice may no longer be large enough to sustain a stable perennial ice cover. Data from the 2005-2006 season have not yet been analyzed. The study appeared March 2 in Geophysical Research Letters.

New Approach May Lower Drug Prices

John Vaccaro — Sat, 31 Mar 2007 19:11:51 EDT

A team at Princeton University has conducted research that may lead to cheaper manufacturing of drugs. Their use of novel compounds as catalysts appears to overcome one of the fundamental problems in producing biologically active chemicals. Biological systems are sensitive to the way a molecule is structured as well as what it is made of. To illustrate: hold up a hand and extend your thumb and create a loop with your index finger. Think of this as a molecule. Now rotate your hand so the thumb is on top. Although in the composition of our pretend molecule your hand and fingers are the same in either position, in the biological world, only one of those two positions could be a valid drug. The other position would be inactive, or maybe even harmful. With current technology, synthesizing a drug results in a mixture of molecule orientations. Additional processing must be done to remove the molecules that are "pointed the wrong way" so as to increase the drug's biologic activity or specialized "asymmetric" catalysts must be used to produce the drug with only the correct orientation. These additional steps can be extremely expensive and hard to do since we have very few purification tools that can detect the orientation of a molecule.The damage the wrong orientation can do was painfully demonstrated by the thalidomide birth defect tragedy of the 1960s. The correctly oriented version of the drug helped pregnant women overcome morning sickness, but its mirror image caused birth defects.What the Princeton team of David MacMillan, Teresa Beeson, Anthony Mastracchio, Jun-Bae Hong, and Kate Ashton have done is show that by using organic catalysts rather than the classic metal-based catalysts it is possible to synthesize molecules with a preponderance of molecules oriented in a single manner. Since 2000, MacMillan's team at the Merck Center for Catalysis have been working with a new family of catalysts which produce drugs with the correct orientation in greater purity. These catalysts have proven desirable because they are based on organic substances, and are therefore not harmful either to patients or to the environment. Their work has yielded not merely better catalysts, but whole new types of chemical reactions previously unavailable."The big payoff here is that the discovery will allow new chemical reactions to be developed that are powerful yet unprecedented in the field of chemistry," MacMillan said. "They will allow access to correctly structured drugs, and they will do it using cheap, environmentally friendly small organic molecules as catalysts. It's a double whammy."The paper, "Enantioselective Organocatalysis using SOMO Activation", which MacMillan cowrote with first author Teresa Beeson, Anthony Mastracchio, Jun-Bae Hong and Kate Ashton, all members of his research group, appears in the March 29 issue of the journal Science.

SciTech Watch: Congress at Work on the Web

John Vaccaro — Fri, 2 Jun 2006 18:35:09 EDT

If you follow the actions and activities of the United States Congress don't you often wonder what they really do? This week, SciTech Watch looks at a web site that makes the day-to-day activities of the Congress visible to anyone with a web browser.Founded in 2004 by a graduate student, GovTrack.us is the hub of a set of automated tools that collect information about the daily business of Congress. As GovTrack's about page says, the site......fills that role at the federal level by bringing together legislative data from existing government sources and presenting it in a more user-friendly format, and by providing the ability to track legislative events as they happen via email updates and RSS/Atom feeds.GovTrack lists its data sources as:The Library of Congress and the Congressional Research Service The House of Representatives and the Senate The Government Printing Office The Office of Management and Budget and the Congressional Budget Office OpenSecrets TechnoratiGovTrack allow you to monitor Resolutions, Votes and Bills as they are presented to and acted on by both Houses of Congress. You can get the information as email messages or as an RSS/Atom feed to monitor in your favorite news aggregator. From the site's home page you can search for activities based on a Bill Number or a keyword. Further, you can set up custom RSS/Atom feeds based on any topic the site has indexed. Once you choose a topic from the alphabetical list, the site allows you to receive updates on this topic via email or use the created RSS orAtom feed to refresh the search each time your aggregator scans the feed.GovTrack has been nominated for a 2006 Webbie Award in the Politics category.Technorati Tags: Congress, GovTrack, Bill, Vote

SciTech Watch: Indy Racing Tech

John Vaccaro — Sun, 28 May 2006 05:00:59 EDT

This Sunday, May 28th is the 90th running of the Indianapolis 500 race. Join us this week on SciTech Watch as we explore the science and technology behind racing in the Indianapolis Racing League (IRL) at the 2.5-mile Indianapolis Motor Speedway oval track.After 90 years of racing at Indianapolis, technology has taken car capabilities to a very high level. These cars are capable of running in excess of 225 miles per hour for extended periods of time. Their aerodynamics have evolved to use the forces acting on the car to improve stability and speed of the car on the track. Advanced technology is found throughout the IRL. Technology helps increase the cars performance, monitor the engineering state of the cars, protect the drivers, and control the race for maximum safety.Performance The cars that race in the IRL are open-wheel cars, meaning there is no bodywork or fenders around the wheels. The engine is located in the middle of the car behind the driver. The engine drives the rear wheels through a six-speed transmission. The tires used on open wheel racers are 11 to 15 inches wide and smooth, with no tread. At any given time on the track the total surface-area of tire in contact with the track is about one square foot. At race speed the tires have an almost tar-like consistency to exert maximum grip. The chassis of the IRL cars are manufactured by either Dallara or Panoz. They are constructed of carbon fiber and composites and typically weigh about 1500 lbs, excluding fuel and the driver. Each car has a 30-gallon rupture-proof fuel tank and is 192 inches long and 78 inches wide. The Dallara chassis is pictured above.The car is aerodynamically controlled by two major wing surfaces: there are wings on either side of the nose cone and a large wing at the rear of the car behind the rear wheels. Increasing the angle of the wings on the nose of the car forces the front tires down harder on to the track improving steering response. There are three separate rear wing designs. Different designs are used depending on the type of track the cars are racing on. At Indianapolis they use a single plane wing with no flaps. On bigger tracks, a two-element wing is used to increase down force and drag helping to keep the cars at safe speeds. On short tracks or road courses a three-element wing is used to provide maximum down force.The engines for the cars are manufactured by Honda using an aluminum cylinder block. The upper part of the engine is gold plated to help radiate heat. An electronic engine management system, supplied by Motorola, controls a capacitive discharge ignition system. The engine is structurally part of the frame lending its mass to strengthen the chassis. This year the fuel used by the IRL racers will be a blend of methanol and ethanol. Historically, IRL cars ran on pure methanol. In 2007 the cars will switch to pure ethanol as fuel, sending the message that ethanol fuel can be high performance as well as eco-friendly.Monitoring Performance Each IRL car is equipped with a radio telemetry module that transmits engine and chassis data from a speeding race car to the team engineers located in the pits; the telemetry module enhances driver safety and race team strategy by making real-time data available. The system monitors strain, acceleration, pressure, temperature and other parameters feeding this information in real-time back to the racecar's crew in the pits. Analyzing this information allows the crew to see what problems the car may be experiencing and plan corrective action before the car makes its next pit stop.Racing Safely As in any high-performance sport, there is always the possibility of injury to drivers or fans if something unexpected happens on the track. Spectators at the track are protected by a large debris-retaining fence. The fence stands between all public areas, the track, and pit proper. It is constructed of heavy-gauge wire mesh with reinforcing half-inch steel cables. The fences are 15 to 20 feet tall with an additional three to six feet of overhang, which curves back over the track. The overhang is designed to catch flying debris and allow it to fall back on to the track.The IRL race cars and tracks contain many innovative safety features. When a caution is declared during a race, in addition to the yellow flag waving and yellow flashing lights situated around the track, a yellow light also blinks in the cockpit of each race car letting the driver unequivocally know a caution is in progress. Tethers are attached to key suspension and chassis points to prevent the exposed wheel and suspension assemblies from becoming completely detached during a crash. The steering column of the cars is designed to collapse in a collision, keeping the column from hurting the driver. All the tracks where the IRL races now have a significant portion of their race track walls upgraded with an energy-absorbing materialknown as the SAFER (Steel and Foam Energy Reduction) Barrier. When a car collides with this wall, the Styrofoam inserts behind the steel outer wall absorb energy from the contact resulting in less force being transmitted to the driver and reducing the chance of severe injury.All cars carry Delphi's Accident Data Recorder. Serving much like an airplane's flight data recorder, the Accident Data Recorder captures data about the force and direction of the crash for later analysis. If the recorder detects conditions that exceed preset levels, a special indicator is lit signaling to the safety crew that driver injuries are more likely.There are over 100 people dedicated to the safety of the drivers and race fans. Thirty-eight doctors and nurses are on site to treat both fans and drivers. A four-truck, 17-member safety team is on stand-by during practice and races to respond to incidents on the track during races and practice sessions. Each safety truck carries equipment such as hydraulic cutters, fire extinguishers, and video cameras at the front and rear. All crewmembers are certified paramedics or firefighters. They arrive at the scene of an on-track incident within 30 seconds.Race Control To accurately determine the car's position on the track for accurate restarts and finishes, each car carries a radio transmitter positioned 33 inches from the tip of the nose code. Cabling buried under the track collects the signals from the cars and provides timing and scoring information. This allows each team to know where their car and others are in relation to one another. The timing information is accurate to one ten-thousandth of a second. A camera located at the start-finish line snaps pictures at the same interval. The camera played a vital role in determining the race winner at Kansas in 2004 when Buddy Rice edged Vitor Meira by .005 of a second. The timing data is distributed to the racing teams and the public via a sophisticated client-server application written specifically for the IRL.Technorati Tags: IRL, Auto Racing, Indianapolis 500, Racing Technology

SciTech Watch: Venus Express

John Vaccaro — Thu, 18 May 2006 13:33:59 EDT

This week's SciTech Watch takes a look at the new Venus space probe that has arrived at its destination.The Venus Express probe is a project of the European Space Agency (ESA) to study the atmosphere, the plasma environment, and the surface of Venus in great detail. The probe was launched in November, 2005 and arrived in orbit around Venus on April 11, 2006. The spacecraft carries a suite of instruments for gathering visual, spectroscopic, radio, magnetic and plasma data. Venus Express's orbit will be similar to that of the JPL's Magellan probe which orbited Venus from August 1990 till September, 1992. Magellan primarily used Synthetic Aperture Radar to collect data bout the surface of Venus.Here's a summary of what we currently believe conditions on Venus are like: * Distance from Sun: 1.1 x 10^8 km * Orbit Period: 225 Earth days * Radius: 6051 km * Rotational Period (sidereal): 243 Earth days * Average Density: 5.24 g/cm3 * Surface Gravity: 0.907 times that of Earth (8.87 m/s2) * Surface Temperature: 850 F (730 K) * Surface Atmospheric Pressure: 90 times that of Earth * Atmospheric Composition: Carbon dioxide (96%); nitrogen (3+%); trace amounts of sulfur dioxide, water vapor, carbon monoxide, argon, helium, neon, hydrogen chloride, hydrogen fluoride The spacecraft has two distinct operating modes while in orbit around Venus. The Observation phase consists of Nadir pointing, Limb observations, Star occultation and Radio science. Nadir pointing observations are taken while the spacecraft is closest to Venus, Limb observations analyze the Vesuvian atmosphere by examining star light that has through Venus's atmosphere. Star occultation performs spectrographic analysis of star or sun light in ultraviolet or infrared that has transited the Vesuvian atmosphere to obtain information about the components of Venus's atmosphere. The Radio science package on Venus Express will examine the ionosphere, atmosphere and surface of Venus by means of radio waves transmitted from the spacecraft, passed directly through the atmosphere or reflected off the planet surface and received by a ground station on Earth.When not in Observation phase, Venus Express will be in Earth Pointing phase. In this mode, the spacecraft communicates with Earth and recharges its batteries. The spacecraft posses two different high-gain antennas for communications. Earth Pointing is used whenever the spacecraft is not in the observation phase. In the Earth pointing phase, one of the two High Gain Antennas is oriented towards Earth. Which antenna is used is based on the season, so that the spacecraft's cold face remains always protected from the Sun.The planned mission for Venus Express is approximately 500 earth-days. Technorati Tags: Venus Express, Venus,Magellan,ESA

SciTech Watch: The Finest SciFi TV You've Never Seen

John Vaccaro — Thu, 4 May 2006 17:37:21 EDT

Hardly any of the current crop of Science Fiction television shows are of any interest to me. With the exception of Doctor Who, none of the currently airing shows have grabbed my attention. And even Doctor Who is not really science-based Science Fiction, but fantasy woven around scientific or historical facts. There really is a science-based science fiction television out there! I'll wager that anyone outside Canada or the northern United States has never seen it. So join us this week as SciTech Watch explores the world of Regenesis, the Finest SciFi TV You've Never Seen.Regenesis is an hour-long television program created by Christina Jennings and produced by Shaftesbury Films. Airing on Canada's Movie Central and The Movie Network on Sunday nights, Regenesis began its second season on March 19th. Regenesis is set in Toronto, Canada and follows the work of a fiction biotechnology advisory commission that was set up by Mexico, the United States, and Canada. Officially named the North American Biotechnology Advisory Commission, it is known in the show by its acronym, NorBAC. NorBAC has a staff of scientists whose job it is to look at any activities or science in the areas of nanotechnology, biotechnology, and bioweaponry. As a reference point, think the Crime Scene Investigator series on CBS or House on Fox with more science and less gore.Regenesis has a higher science content that any other Science Fiction TV series I have encountered. The characters regularly deal with biological and environmental threats in a detailed fashion, managing to educate the viewer without long pieces of boring exposition. The first season of Regenesis dealt with topics such as bioterroism, Mad Cow disease, power blackouts, and Spanish Influenza. The Spanish Flu story arc is particularly interesting given all the press around the current Bird Flu and the recreation of the Spanish Flu genome. So far in the nine episodes of season two, arcs have included HIV as bioterrorism, a cure for juvenile diabetes, and acid rain on Mexico City. There is even a link off of the Regenesis web site to the Ontario Genomics Institute where they discuss the science involved in each episode.This show has an ensemble cast, with the Chief Scientist, David Sandstrom, played by Peter Outerbridge, and the lab's Executive Director, Caroline Morrison, played by Maxim Roy in most scenes. The remaining cast include Conrad Pla as Carlos Serrano, Mayko Nguyen as Mayko Tran, Dmitry Chepovetsky as Bob Melnikov, Sarah Strange as Jill Langston, and Greg Bryk as Weston Field.Most episodes of Regenesis contain two or more story arcs. Some arcs are completed within an episode, some within a few episodes, and some story arcs last an entire season. The multitude of arcs make each show more realistic in that the characters are dealing with multiple events and problems not all related to a single story arc.The bad news, right now there is no airing of Regenesis in the United States and it is carried by two premium cable TV services in Canada: Movie Central and The Movie Network. You can get a podcast stream from the Regenesis Remixed podcast site. The Remixed site has MP3s of show music and is hosted by the music producer for Regenesis's soundtrack, Andrea Higgins. New in season two is the ability to download video summaries of episodes in iPod video format. The first six of these video podcasts are available at the Regenesis site or you can subscribe through iTunes.My apologies to Tony Steidler-Dennison for stealing his Roadhouse tag line The Finest Blues You've Never Heard for my column title.

SciTech Watch - Podcasting: What's On?

John Vaccaro — Thu, 27 Apr 2006 21:21:14 EDT

Podcasting has become the generic term for creating and distributing audio files for listening on personal computers or portable music players. But what kind of programs are available as podcasts? How do you find more podcasts you will like? Join us this week on SciTech Watch as we explore Podcasting: What's on?To explore what sort of programs or content we can find available as a podcast, we're going to dissect my own podcast playlist to see what categories the things I listen to fall into. We'll also explore Internet resources to help you find additional podcasts of things you like.MusicPeople who create podcasts realized early on that if they played popular music or more specifically copyrighted music without permission, they would be liable for copyright infringement. Since podcasting is a new technology, none of the existing music-licensing methods accurately apply. So podcasters began looking for musical artists who have not signed on with a major music label and have enough control over their music to be able to grant podcasters the explicit right to play their music on podcasts. Currently, many small music labels are also granting podcasters rights to play music from their stable of artists in a podcast. Music whose copyright holders have explicitly allowed their music to be played on podcasts is known as podsafe music.I have several music podcasts in my playlist: The Roadhouse, Raven and the Blues, Celtic Music News, Renaissance Festival Podcast, and Knobtweakers. Four of these follow the same format: 5 - 10 songs played in a single podcast, interspersed with commentary from the podcaster. The last podcast on the list, Knobtweakers, a podcast devoted to electronic music, actually puts individual songs out as .MP3 files.The popular radio program Echoes, which features a wide array of styles, from acoustic to electronic, jazz to space music, avant-garde to rock, doesn't podcast their actual program, but does have a stream of material that they podcast providing short interviews with artists featured on Echoes and snippets of their music.For a look inside a working band, check out the Lascivious Biddies podcast. These four New York girls produce a regular podcast about their adventures and gigs as a band and always include a couple of their tunes.Interviews/ConversationsPodcasts give you the ability to hear interviews or conversations with thought-leaders and other individuals on you own schedule. Since I'm a computer and science geek, I get a lot of these types of podcasts from IT Conversations. IT Conversations also has several themed podcasts with recurring hosts who interview people involved with the work connected to the series' theme. They carry Moira Gunn's excellent Tech Nation series which interviews authors, scientists and others in science and technology fields. Tech Nation has a spin-off, Biotech Nation where she interviews scientists and others working in various fields of Biotechnology. Other recurring series include Globeshakers, Opening Move, and Sound Policy. The Science and Society podcast broadly focuses on nanotechnology, life sciences, energy and the environment, space exploration, and K-12 science education. Over the last several years they have interviewed more than 400 trendsetting and groundbreaking researchers, industry-leading executives, and senior government officials. Two of the best technology-oriented conversation podcasts are the Gillmor Gang where Steve Gillmor hosts a regular hour-long roundtable discussion on the various technology news. This Week in Tech (aka TWiT) features Leo Laporte and a round-table of folks who worked with Leo at TechTV. The TWiT discussions are wide-ranging, pretty geeky and always fun.For conversation about science fiction programming on television and in the movies, check out the Slice of SciFi podcast for weekly interviews and conversation about new science fiction programming.Lectures/ConferencesIT Conversations is a leader in providing audio of speakers at various lectures and conferences. They post individual sessions from each conference as separate files allowing you to pick which lectures you want to listen to. They have provided recorded sessions from a plethora of events including Pop Tech, Open Source Convention (aka OSCON), and Web 2.0.StoriesOne of the great effects of the rise of podcasting has been the resurgence of story-telling podcasts. Some authors are reading their works as podcasts with each chapter being a single .MP3 file. Cory Doctorow podcasts readings of his shorter works in science fiction and the Escape Pod podcast features reading of short fantasy and science fiction stories by established authors. There is even a web site dedicated to delivering audiobook chapters via podcasting at Podiobooks. The Morning Stories podcast is a ten minute segment produced by WGBH radio in Boston and based on their radio series of the same name. The segments feature interesting personal stories told by the story's author.VarietyA lot of podcasts have a variety of elements in them, including music, conversation, promotional clips for other podcasts, etc. The granddaddy of all the variety shows is Adam Curry's Daily Source Code. Adam is a former DJ and MTV VJ. He was instrumental in getting the software mechanisms in place to easily distribute podcasts. The Daily Source Code combines new podsafe music, Adam's commentary on his life, work and the world around him, as well has promos for other podcasts. The first 30 minutes of Adam's show is available on Sirius Satellite Radio while the entirety of the show is available as a podcast.The Internet makes podcasts available no matter what country they originate in. I listen to three podcasts produced outside the U.S. Caribbean Free Radio is produced in Trinidad by Georgia Popplewell. She includes local music, news and of course football news in her podcast. Scott Lockman is the host of the Tokyo Calling podcast. His was one of the first podcasts to originate from Tokyo, Japan. Tokyo Calling is Scott's vehicle for talking about life, parenthood, work, and much more about life in Japan's largest city. From Australia comes the G'day World podcast the very first Australian podcast, an irreverent rant about technology, science, politics, and the arts by Cameron Reilly.Finding MoreThere are several good sources of podcasts including the PodcastDirectory, Podcast.net, Podcast Alley, NPR, Indiepodder and iPodder. These sites will let you browse podcasts by genre or category as well as doing key word searches of the podcast's descriptive text. When you find interesting podcasts, these directories will point you to the correct URL for adding them to your podcast client.If you have other great podcasts you listen to, feel free to leave information about them in the comments so we all can enjoy.

SciTech Watch: Lactic Acid Not Athlete's Poison

John Vaccaro — Fri, 21 Apr 2006 17:47:43 EDT

Most people who exercise regularly have heard about the problems lactic acid build-up in major muscles can cause. Muscle fatigue, cramping, and reduced performance have all been tied to increased levels of lactic acid in the affected muscles. This week in SciTech Watch we take a look at the results of new research on lactic acid's role in metabolism and exercise. It seems lactic acid can be your friend.Exercise physiologists tell us that lactic acid is a by-product of metabolism in muscle cells as they do work. When lactic acid, also known as lactate, builds up to too high a level the muscle's functioning is impaired or performance reduced. Lactic acid is considered a waste product that must be flushed out of the muscle to keep its performance at high levels.Now results from 30 years of metabolic research at the University of California, Berkley are painting a strikingly different picture of lactic acid's role in metabolism. The two methods which a muscle uses to do work have been found to be linked together rather than being two distinct methods, as thought previously. The two methods, anaerobic metabolism and aerobic metabolism are now believed to be linked together and the link is lactate.When muscle cells convert carbohydrates to energy they do so in an oxygen-free cycle called the glycolytic pathway. This method produces lactate as a by-product. The lactate is flushed out into the blood stream for reuse or disposal. During intense exercise, a second energy production method, the oxidative pathway, becomes active. This method uses oxygen and lactate to provide more energy for muscle work. Thus the lactate produced by the glycolytic pathway is used by the oxidative pathway as fuel to produce additional energy.As people exercise regularly, the muscle cells are exposed to elevated levels of lactate. Repeated exposure to elevated levels of lactate triggers muscle cell adaptations producing the ability to use lactate as a second energy source rather than treating lactate as a waste product. Many athletes use interval training to achieve high levels of performance. Interval training works because the short bursts of intense activity cause spikes in lactate levels which encourage the activation of the oxidative pathway. George Brooks, UC Berkeley professor of integrative biology, has been performing experiments on frogs and muscle metabolism over the last ten years. His research indicates that the mitochondria in cells are the sites where oxidative metabolism is occurring. Further, interval training increases the number of lactate transporter molecules found in mitochondria. Lactate levels measured during endurance training indicated that lactate levels in the blood were decreasing even though cells were producing the same amounts of lactate. Two scientific papers on this subject provide direct evidence of a complex of proteins inside a cell whose function it is to collect lactate and transport it to the mitochondria for use by the oxidative metabolism pathway.The first paper by Professor Brooks is in press for the American Journal of Physiology, Endocrinology and Metabolism, was published online in January. The second paper will be published in the near future. Professor Brooks, and colleagues Takeshi Hashimoto and Rajaa Hussien did their research at UC Berkeley's Exercise Physiology Laboratory. An overview of Professor Brooks' work is available at the EurekAlert web site.