Image of the Day


Donate Button 1

Donate Button 2

Post 4427

Image of the Day

by Tom Chao, SPACE.com Producer

Blow, Winds

Credit: Canada-France-Hawaii Telescope/Coelum
Friday, August 30, 2013: The Cone Nebula (NGC 2264) consists of a glowing cloud of ionized gas excited by the surrounding hot, massive young blue stars. Strong winds of particles blow from these stars, shaping the residual gas left from a spent star formation region, creating these structures with striking appearances.

You Wear My Polar Collar

Credit: NASA/JPL-Caltech/Space Science Institute
Thursday, August 29, 2013: Cassini spacecraft has now seen Titan’s polar collar in ultraviolet light; previously it was observed by Voyager 2 and the Hubble Space Telescope. Researchers studying the collar’s cause and evolution believe it to be seasonal in nature. This view looks toward the Saturn-facing hemisphere of Titan. Cassini spacecraft took the image on April 13, 2013 at a distance of approximately 1.1 million miles (1.8 million kilometers) from Titan.

Emission Nebula NGC 6357

Credit: ESO
Wednesday, August 28, 2013: A small part of emission nebula NGC 6357 glows in this image. The nebula lies some 8000 light-years away in the tail of the southern constellation of Scorpius (The Scorpion). The image contains a large amount of ionized and excited hydrogen gas. The cloud bathes in intense ultraviolet radiation (mainly from the open star cluster Pismis 24 which contains some massive, young, blue stars) which it re-emits as visible light, in this distinctive red hue. The star cluster sits outside the frame, but diffuse light from the cluster illuminates the cloud at right center. This close-up of the surrounding nebula displays a mesh of gas, dark dust, and newly born and still forming stars.

Brighter Than a Thousand Thousand Suns

Credit: NASA/JPL-Caltech
Tuesday, August 27, 2013: This new view shows the Carina nebula as seen in a new image made by NASA’s Spitzer Space Telescope. At the center of the nebula lies Eta Carinae, one of the most massive stars in the galaxy. Its blinding glare sculpts and destroys the surrounding nebula. Eta Carinae represents a true giant of a star. It contains 100 times the mass of our sun, and burns its nuclear fuel so quickly that it blazes at least one million times brighter than the sun. It has brightened and faded over the years, and some astronomers think it could explode as a supernova in the not-too-distant future.

Space Rock

Credit: NASA/JPL-Caltech
Monday, August 26, 2013: Potentially hazardous near-Earth object 1998 KN3 zips past a cloud of dense gas and dust near the Orion nebula. NEOWISE, the asteroid-hunting portion of the Wide-field Infrared Survey Explorer, or WISE, mission, captured infrared pictures of the asteroid, the yellow-green dot at upper left. The sun warms asteroids to roughly room temperature, so they glow brightly at the infrared wavelengths used by WISE. WISE infrared data reveals that this asteroid is about 0.7 mile (1.1 kilometers) in diameter and reflects about 7 percent of the visible light falling on its surface, making it relatively dark. In this image, blue denotes shorter infrared wavelengths, and red, longer ones. Hotter objects emit shorter-wavelength light, so they appear blue. The coolest gas and dust appears red.

So Many Stars

Credit: Miguel Claro/www.miguelclaro.com
Thursday, August 22, 2013: Astrophotographer Miguel Claro captured the Milky Way in Monte Faperras, Mourão, above Lake Alqueva, in the Alqueva Dark Sky Reserve, Portugal, on July 15, 2013. The photo includes Cygnus (The Swan), with the North America nebula (NGC 7000). Down to the right lies the constellation of Sagittarius and many nebulas: M16, M17, M24, M20, and M8, plus the supergiant star Antares. At the top, the bright star is Vega, in the constellation of Lyra, which forms the well-known Summer Triangle with Deneb and Altair. At the left edge of the image, between the arc of the Milky Way and the horizon, Andromeda Galaxy M31 shines. Above the horizon line, the green/yellow band represents the airglow phenomenon.

Man, Nature, Technology

Credit: ESO/H. Dahle
Wednesday, August 21, 2013: The Southern Hemisphere’s night sky shines in this photo taken by astronomer Håkon Dahle at ESO’s La Silla Observatory in the Atacama Desert of Chile. Dahle appears silhouetted in the foreground while telescope domes loom in the distance. Håkon took this photo during a week-long observing run at the MPG/ESO 2.2 telescope. Although the Milky Way is usually outshined by light pollution or even the moon, the skies at La Silla are so dark that it is possible to see a shadow cast by the light of the Milky Way alone.

Cat’s Eye

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Tuesday, August 20, 2013: On Mercury lies Eminescu crater, illuminated by a bright halo of material around its edge. A ray system emanating from nearby crater Xiao Zhao appears on the right side of the image. The shape and coloration of Eminescu crater suggest the familiar sight of the Cat’s Eye Nebula. MESSENGER spacecraft acquired this image on January 3, 2012. Image released August 15, 2013. [See our MESSENGER gallery.]

Across the Sun

Credit: SDO
Monday, August 19, 2013: On August 6, 2013, the moon made an appearance in NASA’s Solar Dynamics Observatory’s view for almost 90 minutes. This occurrence has happened before, and it provides scientists with useful information. The lunar limb’s sharp edge assists researchers in measuring how light diffracts around the telescope’s optics and filter support grids. This data allows the scientists to fine-tune their instruments more precisely. The sun was imaged here in extreme ultraviolet light, and at the time, a large, bright active region sat right in the central area of the solar disk. SDO orbits about 22,400 miles (36,000 km) above the Earth.

First!

Credit: Tommy Eliassen
Friday, August 16, 2013: Aurora-spotter Tommy Eliassen took his first aurora photo of the autumn season in Hemnesberget, Nordland, Norway, on August 14, 2013.

You Know Your Straight Line From the Curve

Credit: Adam Block
Thursday, August 15, 2013: Streaks of Perseid meteors intersect arcing star trails above the Mt. Lemmon SkyCenter in Arizona. 274 exposures combine in this image by Adam Block, made on August 11, 2013.

How Many Stars?

Credit: ESA/Hubble & NASA. Acknowledgement: Luca Limatola
Wednesday, August 14, 2013: In this image, two spiral galaxies collide, however they lie millions of light-years away, far beyond the cloud of blue and red stars near the merging spiral. This sprinkling of stars is actually an isolated, irregular dwarf galaxy named ESO 489-056. This galaxy floats 16 million light-years from Earth in the constellation of Canis Major (The Greater Dog). It contains a few billion red and blue stars — a very small number when compared to galaxies like the Milky Way, estimated to contain around 200 to 400 billion stars, or the Andromeda Galaxy, which contains one trillion. Image released August 12, 2013.

Two of a Kind

Credit: ESO
Tuesday, August 13, 2013: Galaxies NGC 799 (below) and NGC 800 (above) lie about 300 million light-years from Earth, in the constellation of Cetus (The Whale). These objects are spiral galaxies, with long arms winding towards bright bulges at their centers. NGC 799 possesses a bar structure, extending from its central bulge, and the spiral arms wind out from the ends of the bar. The small NGC 800 claims three bright spiral arms, whilst NGC 799 only owns two relatively dim, but broad spiral arms. As with all situations when two galaxies sit close enough together, possibly these two galaxies will interact over hundreds of millions of years through gravitational disturbances. Image released August 12, 2013.

Watch the Sun

Credit: ESA/SWAP PROBA2 Science Centre
Monday, August 12, 2013: The SWAP instrument on board ESA’s Proba-2 spacecraft saw the sun on July 30, 2013. SWAP stands for “Sun Watcher using Active Pixel System detector and Image Processing.” The instrument is a small telescope capturing the solar corona at wavelengths corresponding to temperatures of about a million degrees (around 17.1 nanometers). [Get ourwallpaper of this image.]

Will the Circle Be Unbroken?

Credit: NASA/JPL-Caltech
Friday, August 9, 2013: Galaxy Messier 94 (also known as NGC 4736) appeared historically to possess two quite different rings: a brilliant, compact band around the galaxy’s core, and a faint, broad swath of stars outside its main disk. Astronomers recently discovered that the outer ring, seen here in a deep blue glow of starlight, might actually be an optical illusion. A new, more complete picture of Messier 94 indicates that two separate spiral arms, from our perspective, take on the appearance of a single, unbroken ring.

Wild Colors

Credit: ESA/DLR/FU Berlin (G. Neukum)
Thursday, August 8, 2013: The region of Mars to the north of Hesperia Planum, including part of the Tagus Valles, appears in a color-coded overhead digital terrain model acquired by ESA’s Mars Express spacecraft. (Blue indicates lower elevation.) Evidence of a watery past for the larger crater at top left can be seen in the top right of the crater in the shape of a small, winding river channel. The view was taken on 15 January 2013, during orbit 11504.

I’ve Got My Orange Belt

Credit: C. Liefke/ESO
Wednesday, August 7, 2013: An almost full moon hangs above Paranal Observatory in Chile, seconds after the sun has disappeared behind the horizon. The orange glow of the sunset shines on the 1.8-metre VLT Auxiliary Telescopes. The intriguing part of the image hangs in the sky beyond, the atmospheric phenomenon known as the Belt of Venus. The shadow of the Earth creates the grey-bluish shadow above the horizon, and right above glows a pinkish band. The reddened light of the setting sun being backscattered by the Earth’s atmosphere produces the phenomenon. This effect can also appear right after sunset, or a similar effect can appear during a total solar eclipse.

In These Arms

Credit: ESO
Friday, August 2, 2013: Grand design spiral galaxy Messier 100, located in the southern part of the constellation of Coma Berenices, lies about 55 million light-years from Earth. It faces Earth, presenting a spectacular appearance showing well defined spiral arms. The galaxy also possess the faintest of bar-like structures in the center. The photo shows the main features of a galaxy of this type: clouds of hydrogen gas, glowing redly when re-emitting the energy absorbed from newly born, massive stars; uniform brightness of older, yellowish stars near the center; and black dust trails weaving through the galaxy arms. Messier 100 represents one of the brightest members of the Virgo Cluster, the closest cluster of galaxies to our galaxy, the Milky Way.

Lights of a Summer Night

Credit: Kevin Palmer
Thursday, August 1, 2013: During early July 2013, Astrophotographer Kevin Palmer visited Weinberg King State Park in western Illinois to escape light pollution. He was hoping to make a time-lapse video of the Milky Way rising, but as he tells it: “After setting up my camera to shoot a sequence of images, the high humidity caused the lens to fog over after only 15 minutes. The video was ruined. But I had noticed the fireflies were very active on this night. When I was sitting down trying to look at a star chart, I had fireflies landing and crawling on me. (But I didn’t mind that much, I’ll take fireflies over mosquitoes and ticks any day.) When I got home and looked at the shots before the lens fogged up, I noticed lots of green streaks from fireflies at the bottom of the pictures. A popular astrophotography technique is to combine a series of pictures to make a star trail image that shows the stars’ apparent motion through the night sky. I decided to try something different–I took one image of the night sky and combined it with 10 images of the fireflies.” [See Photos: Stunning Night Sky Stargazing Images of July 2013]

Image of the Day Archives

Credit: NASA, ESA and Orsola De Marco (Macquarie University)
For older Image of the Day pictures, please visit the Image of the Day archives. Above: NGC 2467.
Advertisements

Under the Greenland Ice Sheet


Donate Button 1

Donate Button 2

Post 4426

Under the Greenland Ice Sheet

By LiveScience Staff   |   August 29, 2013 01:53pm ET

A topographic map of Greenland from bedrock elevation data.

Credit: J. Bamber, University Bristol
A topographic map of Greenland from bedrock elevation data.

3D view of the subglacial canyon, looking northwest from central Greenland.

Credit: J. Bamber, University Bristol
3D view of the subglacial canyon, looking northwest from central Greenland.

3D view of the subglacial canyon, looking to the southeast from the north of Greenland

Credit: J. Bamber, University Bristol
3D view of the subglacial canyon, looking to the southeast from the north of Greenland.

3D view of the subglacial canyon, northwest from central Greenland

Credit: J. Bamber, University Bristol
3D view of the subglacial canyon, northwest from central Greenland.

3D view of the subglacial canyon, northwest from central Greenland.

Credit: J. Bamber, University Bristol
3D view of the subglacial canyon, northwest from central Greenland.

Image Gallery: Combat Sports in Ancient Rome


Donate Button 1

Donate Button 2

Post 4425

Image Gallery: Combat Sports in Ancient Rome

Owen Jarus, LiveScience Contributor

Mixed Martial Arts

Credit: Photo by Nicholas Milner, British Institute at Ankara
A new inscription reveals that a Roman city in Turkey, Oinoanda, turned to a mixed martial art champion named Lucius Septimius Flavianus Flavillianus to recruit and deliver soldiers for the empire’s army. It is written in Greek.

Champion Athlete

Credit: Photo by Nicholas Milner, British Institute at Ankara
Flavillianus was so successful that he was deified after his death, with statues being erected his memory. The inscription was carved onto the base of a statue of him. This base was discovered in 2002 in the city’s agora, a central public space.

Origins in Greek Sports

Flavillianus excelled at two sports, wrestling and pankration, winning victories in Athens, Argos and Neapolis. Both of these sports have roots in ancient Greece.

Roman Empire

By the third century A.D., Greece and was part of the Roman world; however its culture lived on and Greek-speaking inhabitants of Turkey kept up these athletics.

Greek vs. Roman Sports

One notable difference between the Roman and Greek sports is that while the famous Roman gladiator matches tended to be fought by slaves, in Greek sports the competitors were typically free individuals. Flavillianus was actually a Roman equestrian, a man of some wealth.

Anything Goes

Credit: Photo by Marie-Lan Nguyen, CC Attribution 2.5
Pankration was a mixed martial art that was well known for its bloodiness. The only two rules know were: no eye gouging and no biting, other than that anything went. The goal was to knock your competitor unconscious or get them to submit. Shown here, an artifact in the Metropolitan Museum of Art showing two pankratiasts fight before a trainer and onlooker around 500 B.C.

Bend Ankles & Twist Arms

Credit: Photo by Matthias Kabel CC Attribution 2.5
A writer named Philostratos who lived around the same time as Flavillianus wrote that pankration competitors are “skilful in various ways of strangulation. They bend ankles and twist arms and throw punches and jump on their opponents.” Shown here, a bronze artifact in Staatliche Antikensammlungen in Munich showing two pankratiasts fight it out, second century B.C.

Greek Wrestling

Credit: Photo courtesy Walters Art Museum, through Wikimedia, CC Attribution Share-Alike 3.0 Unported
Flavillianus also excelled at wrestling. Unlike modern-day versions of the sport, the goal wasn’t to pin your opponent but simply to throw him onto the ground. Whoever threw their opponent three times first won the contest. Shown here, a solid-cast bronze artifact from the second century B.C.

Brutal Boxing

Credit: Photo by Marie-Lan Nguyen, CC Attribution 2.5 Generic, Metropolitan Museum of Art, circa 520 BC
Another Greek combat sport practiced in Roman times was boxing. We have no indication that Flavillianus took part in it. By the third century A.D., a boxing glove known as the caestus was worn that could be filled with metal and glass fragments. One good hit could easily knock a person out. The fight continued until someone was knocked out or signaled submission. Needless to say injuries, including death, were common in this sport.

Photos of Samurai: The Last Century of Japanese Warriors


Donate Button 1

Donate Button 2

Post 4424

Photos of Samurai: The Last Century of Japanese Warriors

Owen Jarus, LiveScience Contributor   |   August 29, 2013 09:43am ET

The hilt of a tachi

Credit: Owen Jarus
A Samurai training text dating to 1844 has been deciphered; the text served as a primer for students learning the martial art of Takenouchi-ryū. The text reads: “When [knowledge] is mature, the mind forgets about the hand, the hand forgets about the sword,” a status requiring a calm mind and one few students could hope to achieve. This picture shows the hilt of a tachi (slung sword), dating to 1861, which would have been used by a high-ranking young Samurai. The sword with mounting is now in the Royal Ontario Museum in Toronto, Canada.

The mounting for the tachi

Credit: Owen Jarus
The mounting for the tachi sword is made of lacquered wood and contains gold decoration and silver fittings. It would have been made for a samurai who was relatively wealthy and high ranking. By 1861 many samurai were struggling to survive on a meager fixed income and had to seek loans to survive.

Samurai armor

Credit: Owen Jarus
This 19th-century Samurai armor contains a mempo, a face mask that, in addition to being decorative, would potentially have had a strong psychological effect on any would-be opponent. This suit of armor is in the Royal Ontario Museum in Toronto, Canada.

Hand-made armor

Credit: Owen Jarus
Royal Ontario Museum researchers say that the 19th-century Samurai armor is made of lacquered iron, silk lacing, doeskin and engraved gilt copper. The decorations are colorful and carefully made.

Significant protection

Credit: Owen Jarus
In the 19th-century, Samurai armor still offered full protection down to the gloves, pelvis, legs and boots. This is remarkable considering that gunpowder weapons had been available in Japan for more than two centuries.

Full armor

Credit: Wikimedia.
A photograph taken around 1860 showing a Samurai in full armor with sword. Within two decades of this photo being taken the Samurai would effectively be abolished and Japan would move to a conscript army that would largely consist of peasants.

Creative design

Credit: Owen Jarus
In the 19th century the helmets the Samurai worn were, at times, created in very creative ways. This helmet, which Royal Ontario Museum researchers say is a product of the Myochin School, is made of iron and depicts the face of an ogre.

Decorative headpiece

Credit: Owen Jarus
This helmet was made around 1790 and is made of lacquered iron and wood, silk lacing and gilt copper fittings according to Royal Ontario Museum researchers. An elaborate and decorative piece created at a time when the samurai had relatively few conflicts to fight.

Weapons of choice

Credit: Owen Jarus
While only Samurai could use long swords Royal Ontario Museum researchers notes that merchants were allowed to carry daggers and short swords which could be decorated lavishly. This Aikuchi-type tanto (dagger) may have been worn by a merchant.

Practical yet beautiful

Credit: Owen Jarus
This stirrup would have been used by a samurai mounting a horse, helping him stay mounted. Royal Ontario Museum researchers say that this example was made in 1852 and was decorated with gold maki-edecoration.

Ancient weapons

Credit: Owen Jarus
By the 19th century gunpowder weapons had been in use in Japan for over two centuries, its users included the samurai. This percussion lock pistol dates to the mid-19th century and is now in Toronto’s Royal Ontario Museum.

For the emperor

Credit: Wikimedia.
During the Boshin War, fought in 1668-1669, samurai fought against the Tokugawa Shogunate (which had effectively ruled Japan for over two centuries) in an effort to restore the emperor to full political power in hopes he would expel foreigners. While the emperor was restored his new government ended up doing the exact opposite, embracing western ways, reforming the military and effectively abolishing the samurai. This photograph shows samurai from the Chosyu clain, fighting for the emperor, in the Boshin War.

19th-Century Samurai Training Text Deciphered


Donate Button 1

Donate Button 2

Post 4423

19th-Century Samurai Training Text Deciphered

Owen Jarus, LiveScience Contributor   |   August 29, 2013 09:46am ET
A Samurai in full armor with sword.
A photograph taken around 1860 showing a Samurai in full armor with sword. Within two decades of this photo being taken the Samurai would effectively be abolished and Japan would move to a conscript army that would largely consist of peasants.
Credit: Wikimedia.

A training text, used by a martial arts school to teach members of the bushi (samurai) class, has been deciphered, revealing the rules samurai were expected to follow and what it took to truly become a master swordsman.

The text is called Bugei no jo, which means “Introduction to Martial Arts” and is dated to the 15th year of Tenpo (1844). Written for samurai students about to learn Takenouchi-ryūa martial arts system, it would have prepared students for the challenges awaiting them.

“These techniques of the sword, born in the age of the gods, had been handed down through divine transmission. They form a tradition revered by the world, but its magnificence manifests itself only when one’s knowledge is ripe,” part of the text reads in translation. “When [knowledge] is mature, the mind forgets about the hand, the hand forgets about the sword,” a level of skill that few obtain and which requires a calm mind.

The text includes quotes written by ancient Chinese military masters and is written in a formal kanbun style, a system that combines elements of Japanese and Chinese writing. The text was originally published by scholars in 1982, in its original language, in a volume of the book “Nihon budo taikei.” Recently, it was partly translated into English and analyzed by Balázs Szabó, of the department of Japanese studies at Loránd Eötvös University in Budapest, Hungary. The translation and analysis are detailed in the most recent edition of the journal Acta Orientalia Academiae Scientiarum Hungaricae.

Among its many teachings, the text tells students to show great discipline and not to fear the enemy’s numbers. “To see bad as good is like stepping out of the gate we see the enemy, though numerous we see them as few, therefore no fear awakes, so we triumph when the fighting is just started,” it reads in translation, quoting a teaching from the Seven Military Classics of ancient China.

Last century of the Samurai

In 1844, only members of the Samurai class were allowed to receive martial arts training. Szabó explained in an email to LiveScience that this class was strictly hereditary and there was little opportunity for non-samurai to join it.

tachi, slung sword, samurai
This picture shows the hilt of a tachi (slung sword), dating to 1861, which would have been used by a high-ranking young Samurai.
Credit: Owen Jarus

Samurai students, in most cases, would have attended multiple martial arts schools and, in addition, would have been taught “Chinese writing, Confucian classics and poetry in domain schools or private academies,” Szabó explained.

The students starting their Takenouchi-ryū training in 1844 may not have realized that they lived at a time when Japan was about to undergo tremendous change. For two centuries, there had been tight restrictions on Westerners entering Japan, something that would be shattered in 1853 when the U.S. commodore Matthew Perry sailed into Tokyo Bay with a fleet and demanded that Japan enter into a treaty with the United States. In the two decades that followed, a series of events and wars erupted that would see the downfall of the Japanese Shōgun, the rise of a new modernized Japan and, ultimately, the end of the Samurai class.

Samurai rules

The newly translated text sets out 12 rules that members of theTakenouchi-ryū school were expected to follow. Some of them, including “Do not leave the path of honor!” and “Do not commit shameful deeds!” were ethical rules samurai were expected to follow.

One notable rule, “Do not let the school’s teachings leak out!” was created to protect the school’s secret martial art techniques and aid students should they find themselves in a fight.

“For a martial arts school … to be attractive, it was necessary to have special techniques enabling the fighter to be effective even against a much stronger opponent. These sophisticated techniques were the pride of the school kept cautiously in secret, as their leaking out would have caused economic as well as prestige loss,” writes Szabó in his paper.

Two other, perhaps more surprising, rules, tell students “Do not compete!” and “Do not tell bad things about other schools!”

Modern-day Westerners have a popular vision of the samurai fighting each other regularly, but by 1844, they were not allowed to duel each other at all, Szabó writes.

The Shōgun Tokugawa Tsunayoshi (1646-1709) had placed a ban on martial art dueling and had even rewritten the code the samurai had to follow, adapting it for a period of relative peace. “Learning and military skill, loyalty and filial piety, must be promoted, and the rules of decorum must be properly enforced,” the Shōgun ruled (translation from the book “Studies in the Intellectual History of Tokugawa Japan,” by Masao Maruyama, Princeton University Press, 1974).

Secret skills

The text offers only a faint glimpse at the secret techniques the students would have learned at this school, separating the descriptions into two parts called “Deepest Secrets of Fistfight” and “Deepest Secrets of Fencing.”

One section of secret fistfight techniques is called Shinsei no daiji,which translates as “divine techniques,” indicating that such techniques were considered the most powerful. Intriguingly, a section of secret fencing techniques is listed as Ōryūken, also known as iju ichinin,meaning those “considered to be given to one person” — in this case, the headmaster’s heir.

The lack of details describing what these techniques looked like in practice is not surprising, Szabó said. The headmasters had their reasons for the cryptic language and rule of secrecy, he added. Not only would they have protected the school’s prestige, and students’ chances in a fight, but they helped “maintain a mystical atmosphere around the school,” something important to a people who held the study of martial arts in high esteem.

Follow LiveScience on TwitterFacebookand Google+. Original article onLiveScience.

How Anthrax Kills: Toxins Damage Liver and Heart


Donate Button 1

Donate Button 2

Post 4422

How Anthrax Kills: Toxins Damage Liver and Heart

By Jesse Emspak, Contributing writer   |   August 28, 2013 01:06pm ET
Anthrax spores
This image shows spores from Bacillus anthracis bacteria, magnified more than 30,000 times.
Credit: Janice Haney Carr, via CDC

A new study of anthrax reveals why the infection is deadly.

The findings also offer clues that could be used to better treat people who are infected, which could possibly improve survival rates, researchers said in their study published  Thursday (Aug. 29) in the journal Nature.

Doctors in developed nations rarely see anthrax cases, but if they do, it’s important to treat the disease correctly, and as soon as possible, said Stephen Leppla, of the Laboratory for Infectious Diseases at the National Institutes of Health.

“The problem with clinicians treating anthrax is that nobody has much experience doing it,” Leppla said. Understanding exactly how anthrax kills can help clinicians tailor better strategies.

Anthrax is caused by bacteria, and can infect people in one of three ways: people might inhale the spores, eat the spores, or take in spores via the skin. All three types of infection can be deadly, though the skin route of infection is much less so, according to the Centers for Disease Control and Prevention. Inhaled anthrax has a mortality rate of about 75 percent, while the gastrointestinal infection kills about 60 percent of infected people, even with treatment. Among those infected through their skin, anthrax mortality drops to 20 percent. [Tiny & Nasty: Images of Things That Make Us Sick]

In the developing world, people become infected though contact with livestock. In the U.S. and Europe, anthrax is now very rare — only one or two cases appear yearly on average in the U.S.

Deadly toxins

The bacteria themselves aren’t what sickens and kills: it’s the toxins the bacteria produce. A doctor can treat a patient with antibiotics and kill all the anthrax bacteria – antibiotics are very effective against the infection. But the toxins the bacteria made remain in the body, and continue damaging cells.

The two toxins produced by anthrax, called lethal toxin and edema toxin, damage many types of cells, but it was thought that their effects on endothelial cells, which line blood and lymph vessels, were what made anthrax so lethal.

In the new study, it was found that wasn’t the case; rather, much of the toxins’ action seems to be in the cells of the heart muscle and the liver.

To track down which cells anthrax targeted, the researchers looked at mice genetically altered so that a protein called CMG2, to which anthrax toxins bind, was absent from their endothelial cells. They compared these mice with another group that had CMG2.

Results showed that both sets of mice were similarly sensitive to anthrax, which meant that anthrax wasn’t killing the mice via damage to endothelial cells.

The researchers next tested mice that were missing the CMG2 protein from their heart cells. Those mice survived the doses of lethal toxin much better than their litter mates that had the protein, which pointed to anthrax’s effects on the heart muscle as the way that it kills.

Similarly, mice without CMG2 in their liver cells fared better when exposed to edema toxin than mice that expressed CMG2, showing that the edema toxin affects the liver.

Leppla noted that it is not clear whether the findings are also true of anthrax in people. Future experiments on primates would confirm the results, he said.

Follow LiveScience on Twitter @livescience. We’re also on Facebook &Google+

 

What Is Garcinia Cambogia?


Donate Button 1

Donate Button 2

Post 4421

What Is Garcinia Cambogia?

By Lauren Cox, Contributing writer   |   August 28, 2013 09:09am ET
Garcinia cambogia fruit

The fruit Garcinia cambogia was once just the less popular cousin of a trendy fruit, the mangosteen. But now, nutritional supplements containing Garcinia cambogia extract have become the rage, touted for their purported ability to curb appetite and stop weight gain.

The gambooge fruit, also known as the Malabar tamarind, grows across southwest India, Myanmar and Indonesia. It ripens to a red or yellowish fruit about the size of an orange, but resembling the shape of a pumpkin.

People have long used the dried gambooge rinds for chutneys or curries, and sometimes as an aid for stomach problems. But in the late 1960s, scientists identified a substance in the rind of the fruit called hydroxycitric acid, or HCA, which has some potentially attractive qualities.

“Some studies have shown that HCA stops an enzyme that turns sugar into fat,” said Catherine Ulbricht, senior pharmacist at Massachusetts General Hospital in Boston and co-founder of Natural Standard Research Collaboration, which reviews evidence on herbs and supplements.

A fruit extract that could interfere with the body’s production of fat? The appeal is obvious. However, good results in test tubes don’t always translate to an entire person.

Does Garcinia cambogia work?

Some studies say HCA works, and some say it doesn’t. Animal studies of HCA showed that mice taking the substance ate less, lost weight and produced less fat from sugar.

Human studies had more conflicting results. One weight loss trial showed no difference between people who took Garcinia cambogia and those who took a placebo pill. Other trials linked HCA to weight loss and healthy blood lipid levels (lipids are fats).

“Further, well-designed clinical trials are needed before any firm conclusions can be made,” Ulbricht said.

If a pharmaceutical company wanted to sell HCA as a drug, the company would have to find stronger evidence that the substance worked, coming from better-designed clinical trials. Without that data, HCA wouldn’t pass U.S. Food and Drug Administration approval, Ulbricht said. But the FDA doesn’t put chemicals sold as nutritional supplements under the same burden of proof as pharmaceuticals. In fact, supplement makers only have to make their products safe to eat and responsibly label them.

Despite the popularity of Garcinia cambogia, it is difficult to track how effective supplements containing it are.

“Preparation of products may vary from manufacturer to manufacturer, and from batch to batch within one manufacturer,” Ulbricht said. That makes it difficult to compare one brand to another or even to measure the effects of a single brand.

Is Garcinia cambogia safe?

People may safely eat the fruit, of course. And clinical trials have shown it’s safe to take Garcinia cambogia extract by mouth — at least for 12 weeks, the length of the studies.

But take caution. Garcinia cambogia has side effects – it may lower a person’s blood sugar, so it can interact with diabetes treatments. The fruit hasn’t been adequately studied in pregnant women or women who breastfeed. And Garcinia cambogia may be a problem for patients with Alzheimer’s or other forms of dementia, Ulbricht said.

In 2009, the FDA issued a safety warning after receiving more than 20 reports of severe reactions, including liver damage, in people taking the supplement Hydroxycut. At the time, Hydroxycut contained Garcinia cambogia extract and other compounds, including chromium polynicotinate and Gymnema sylvestre extract.

Ulbricht said it’s unclear if the Garcinia cambogia extract caused the liver damage.

The bottom line is that people should tell their doctors before trying a new supplement, including Garcinia cambogia and HCA, she said.

Follow LiveScience @livescienceFacebook & Google+.