Tuesday, November 15, 2011
Monday, November 14, 2011
Pembangkit-pembangkit energi, bangunan-bangunan, pabrik-pabrik saat ini yang dibangun diseluruh dunia sebagian besar berdasar pada mebakaran bahan bakar fosil seperti batu bara. Gambar diatas, buruh-buruh di Cina mencari batu bara yang masih bisa digunakan di tempat pembuangan batu api/bara.
(foto dari Reuters)
untuk National Geographic diterbitkan 9 November 2011
Friday, November 04, 2011
Thursday, August 18, 2011
Fireflies Exhibit a Unique Use of Energy. ATP is used to create flashes of light as energy is transferred to an electron in a specialized molecule called luciferin. The energy is released as light as the electron drops back to its original position
Photosynthesis transforms light energy into chemical energy. In bioluminescence, the reverse can happen—chemical energy is converted into light energy. Bioluminescence is common in the oceans, where hordes of glowing microscopic organisms called dinoflagellates lend an eerie bluish cast to fishes, dolphins or even ships that interrupt their movement.
More familiar, perhaps, is the glow of a firefly’s abdomen in the late summer. More than 1,900 species of fireflies are known, and members of each use a distinctive repertoire of light signals to attract a mate. Typically, flying males emit pattern a flashes. Wingless female, called glowworms, usually are on leaves, where they emit light in response to the male. In one species, Photuris versicolor, the female emits the mating signal of another species and then eats the tricked male who approaches her. Some frogs consume so many fireflies that they glow!
In the 1960s, johns Hopkins University researchers William McElroy and Marlene DeLuca asked Baltimore schoolchildren to bring them jar of fireflies. They then used the insects to decipher the firely bioluminescence reaction. McElroy and DeLuca found that light is emitted when a molecule called luciferin reacts with ATP, yielding the intermediate compound luciferin adenylate (figure). The enzyme luciferase then catalyzes reaction of the intermediate with molecular oxygen (O2) to yield Iaxyluciferin- and a flash of light. Oxyluciferin is then reduced to luciferin, and the cycle starts over.
Although we understand the biochemistry of the firefly’s glow, the ways animas use their bioluminescence are still very much a mystery. This is particularly true for the bioluminescent synchrony seen in fireflies in the same trees. When night falls, first one firefly, then another, then another, then more, begin flashing from the tree. Soon the tree twinkles like a Christmas tree. But then, order slowly descends. In small parts of the tree, the lights begin to blink on and off together. The synchrony spreads. A half-hour later, the entire tree seems to blink on and off every second. Biologists studying animal behavior have joined mathematicians studying order to try to figure out just what the fireflies are doing—or saying—when they synchronize their glow.
Life, Sixth Edition Published by McGraw-Hill 2007
Tuesday, July 05, 2011
Monday, July 04, 2011
Photograph by Eric Draper, Reuters
for National Geographic News
If the sun looks a little smaller than usual as you're barbecuing this Fourth of July, it's not your imagination: Earth will be farther from the sun on Monday than on any other day this year.
That's because the orbits of all the planets in our solar system—including Earth's—are not perfectly circular, a phenomenon that was first explained in mathematical detail by the 17th-century German astronomer Johannes Kepler.
Kepler "figured out the orbits of the planets were elliptical in shape and that the sun was offset from the center," explained Mark Hammergren, an astronomer at the Adler Planetarium in Chicago, Illinois.
Earth's elliptical orbit means there will be a point each year when the planet is closest to the sun, called perihelion, and a point when it is farthest away, known as aphelion.
On July 4 our planet will be at aphelion—94,511,923 miles (152,102,196 kilometers) from the sun. This year's perihelion was on January 3, when Earth was 92,955,807 miles (149,597,870 kilometers) from the sun.
On average, Earth is about three million miles—or about 3 percent—farther from the sun at aphelion than at perihelion.
As a result, the apparent size of the sun in the sky will be about 3 percent smaller, but you may not notice the difference without a telescope.
"It's probably not noticeable, but it's certainly measurable," Hammergren said.
Distance Won't Dampen Fourth of July Heat
So if Earth is at its maximum distance from the sun on the Fourth of July, why are those of us in the Northern Hemisphere sweltering in the heat of summer?
Because it's the tilt of the Earth and not our distance from the sun that determines the seasons, Hammergren said.
Earth's north-south axis is tilted by about 23.4 degrees, so during its orbit, the poles point in different directions from the sun.
By coincidence, Earth reaches aphelion when the North Pole is tilted more toward the sun than the South Pole.
"Because the Earth has a tilt, it means that in the summer months [the Northern Hemisphere] receives a longer duration of sunshine—so the day is longer and the night is shorter—but also the sunlight hits the ground more vertically," Hammergren said.
"Those two things together contribute to the difference in heating for the seasons."
Tuesday, June 28, 2011
Photograph by Khalil Hamra, AP
For the first time in centuries, a multi-ton limestone slab—one of dozens—floats free of the "tomb" of a 4,500-year-old, disassembled "solar boat" at the foot of the Great Pyramids in Giza (map), Egypt, on Thursday.
Below are hundreds of delicate wooden "puzzle pieces," protected by the climate-controlled tent built over the site in 2008.
Once the months-long process of extracting the pieces is finished, researchers expect to spend several years restoring the ship before placing it on display in Giza's Solar Boat Museum near the Pyramids. A similar ship found nearby has already been reconstructed and is on display in the museum. At about 140 feet (43 meters) long, the restored ship is thought to be a bit bigger than its still fragmented sister.
Solar boats played an important role in story of the afterlife in ancient Egyptian mythology. Each night the sun god Ra—in the form of the evening sun, Ra-Atum—was thought to sail through the afterlife in one boat to battle gods and beasts until he rose as the morning sun, Ra-Horakhty, and sailed his day boat across the sky.
Buried near the Great Pyramid, the buried sister boats were likely intended to assist Pharaoh Khufu on similar journeys during the afterlife.
Covering pet stores, puppy mills and animal shelters, as well as factory farms, the leather and fur trades, sports and entertainment industries, and finally the medical and scientific profession, EARTHLINGS includes footage obtained through the use of hidden cameras to chronicle the day-to-day practices of some of the largest industries in the world, all of which rely on animals. It draws parallels between racism, sexism, and speciesism, and advocates veganism.
Rekor pohon tertinggi dunia yang semula dipegang sebuah pohon redwood yang dinamai Stratosphere Giant, ternyata telah dipatahkan. Ilmuwan menemukan tiga pohon di sebuah hutan di California bagian utara yang lebih tinggi daripada pohon itu.
Pejabat kehutanan Amerika Serikat Rick Nolan menyatakan, para ilmuwan itu menemukan tanpa sengaja. Ketika tengah mengikuti jalan setapak di hutan lebat dekat Eureka, California pada musim panas, mereka menemukan ketiga pohon redwood pantai yang lebih tinggi daripada Stratosphere Giant setinggi 113 meter.
Pengawas Taman Nasional Redwood itu mengatakan pohon tertinggi dari tiga pohon itu mencapai 115,2 meter, dan dinamai Hyperion. Namun pengukuran tambahan akan dilakukan untuk mengkonfirmasi rekor baru itu, sebelum menyatakan Hyperion sebagai pohon tertinggi.
“Ada dugaan kuat bahwa tiga pohon ini lebih besar daripada pohon yang tumbuh di ekosistem redwood pantai," kata Nolan. “Mereka akan jadi pohon hidup tertinggi.”
Tebalnya kanopi hutan redwood California menghalangi pandangan para ilmuwan yang ingin mengukur ketinggian pohon. Selain harus berjuang menyusuri hutan yang amat lebat itu, para ilmuwan terpaksa harus memanjat ketiga pohon untuk menjatuhkan tali pengukur ke dasar hutan untuk memperoleh angka akurat.
“Mustahil bagi seseorang di permukaan tanah untuk memilih mana yang lebih tinggi dari ketiganya,” kata Ruskin Hartley, direktur konservasi Save-the-Redwoods League.
Monday, June 27, 2011
Photograph by Amanda Rivkin
With a bowl beside her, a child beggar sleeps on the street at midday on the main thoroughfare of Rustaveli Avenue in Tbilisi, Georgia. Although the government of Georgia receives about $65 million in annual transit fees due to the BTC oil pipeline route across its territory, the nation has no mineral wealth of its own to exploit.
Thirty percent of Georgians live in poverty and the unemployment rate is 16 percent.
Friday, April 29, 2011
Photograph by Travis Nykamp, My Shot
This Month in Photo of the Day: Nature and Weather Photos
The Lethbridge Viaduct is the largest railway structure in Canada, standing almost 100 meters high and over 1,600 meters long. This morning it appeared to be skirted in a morning fog.
Wednesday, April 20, 2011
In the main part of Brown's novel, the characters (while pursued by various sinister agencies) are trying to access the secret to the Holy Grail by figuring out the passwords that will open two different cryptexes, one hidden within the other to provide extra security. In the 2006 movie based on the novel, only one cryptex is vital to the plot (though another cryptex is briefly seen in a flashback scene with Sophie as a child). Its password is the Black Cryptex's password.
Thursday, March 17, 2011
Aquilegia (Columbine ; from Latin columba "dove") is a genus of about 60-70 species * of perennial plants that are found in meadows, woodlands, and at higher altitudes throughout the Northern Hemisphere, known for the spurred petals of their flowers.
* Sunset Western Garden Book, 1995:606–607
Saturday, March 12, 2011
Photograph from Kyodo/Reuters
A three-story tsunami obscures all but treetops as it roars into Natori, Japan, on Friday—about the same height as the largest waves seen during the Indian Ocean tsunami that killed hundreds of thousands in late 2004.
Tsunamis have been known to surge vertically as tall as 100 feet (30 meters). Most tsunamis cause the sea to rise no more than 10 feet (3 meters).
Thursday, February 24, 2011
Some 20 million people live in Mexico City, the world's fifth largest metropolitan area. In 1800 the urban fraction of the global population was 3 percent. Today it is 50 percent and rising. In crowded shantytowns, the need for clean water and sanitation is urgent. But urbanization has an upside: Per capita, cities use less energy and pollute less than rural areas.
Saturday, February 19, 2011
In a 3-D image, a bacteriophage aggressively attacks a bacterium "B-movie horror style," according to creator Jonathan Heras of Equinox Graphics, Ltd. The digital ambush snagged an honorable mention in the illustrations category of the 2010 International Science and Engineering Visualization Challenge.
Bacteriophages are viruses with "alien, spindly legs" and sucker-shaped mouths used to "relentlessly pursue their prey," Heras said in a statement. The viruses hijack bacteria's biology and use the victims as virus "replication factories," he said.
Overall, the 2010 entries were "exceptional," communicating science "in a way that the public can understand and appreciate," Monica M. Bradford, Science's executive editor, said in a statement.
"The international competition highlights the innovation and technical expertise of scientists who are able to visually attract a wide audience and engage them to experience the complex nature and beauty of science."
The most detailed 3-D model yet of the HIV virus won first place for illustrations in the 2010 International Science and Engineering Visualization Challenge.
Sponsored jointly by the journal Science and the National Science Foundation, the annual competition awards entries that "engage people worldwide and convey science close up in novel and visually stimulating ways," according to a statement. Judging criteria include visual impact, effective communication, freshness, and originality. (See some of the 2009 winners.)
A Russian team led by Ivan Konstantinov analyzed data from more than a hundred scientific journals to digitally depict HIV as close to the real thing as possible. The two-tone color scheme shows HIV (orange) attacking and fusing with an immune cell (gray). The triangular cut-away shows how the virus integrates itself to turn the cell into a virus factory. (Get the facts on AIDS.)
"We consider such 3-D models as a new way to present and promote scientific data about ubiquitous human viruses," Konstantinov, of the Visual Science Company, said in a statement.
Thursday, February 17, 2011
What causes weather?
Weather is the physical condition of the atmosphere at a particular time. It includes temperature, air pressure and water content.
Weather is produced when air moves from plece to place. This moving air is known as wind. Winds are caused by warm air rising and cooler air mooving to replace it. Warm air is usually less dense then cooler air; therefore, it creates low air pressure. Cool air is more dense and creates high air pressure.
Usually we have fine the weather when the air pressure is high, and we will have clouds, rain or snow when air pressure drops.
1. What is the purpose ot the text?
a. To retell abou weather
b. To explain the process of the information of weather
c. To describe the steps of the information of weather
d. To describe about weather
e. To persuade people about the information of weather
2. When do we find good weather?a. When air moves from place to place
b. When there is moving air
c. When warm air is less dense than cool air
d. Ahen air pressure drops
e. When the air pressure is high
3. The following statements are true except...
a. A physical condition of the atmosphere at a particular time is called weather.
b. Air movement from place to place causes weather.
c. The moving air is called wind.
d. Warm air is usually more dense than cool air.
e. When air pressure drops we usually have clouds.
4. “Cool air is more dense and creates high air pressure.” The synonym of the underline word is...
Wednesday, February 16, 2011
Scarabaeus sacer is a species of dung beetle, found in coastal dunes and marshes around the Mediterranean Basin. It collects balls of dung which it rolls to an underground chamber to feed its offspring. This behaviour inspired the Ancient Egyptians to compare it to the sun god Khepri, and they considered S. sacer to be sacred.
Scarabaeus sacer is found across North Africa, southern Europe and parts of Asia. In the Camargue, S. sacer is almost exclusively a coastal species, living only in dunes and coastal marshes. It serves as the host for the phoretic mite Macrocheles saceri.
The head of S. sacer has a distinctive array of six projections, resembling rays.
Like other dung beetles, S. sacer has no tarsi (usually the final segment of the insect leg) on its front legs, which are specialised for forming a ball of dung. The ball of dung is transported to a underground chamber, and is used to feed the beetle's larvae.
Scarabaeus sacer is the most famous of the scarab beetles. To the Ancient Egyptians, S. sacer was a symbol of Khepri, the early morning manifestation of the sun god Ra, from an analogy between the beetle's behaviour of rolling a ball of dung across the ground and Khepri's task of rolling the sun across the sky.
The Egyptians also observed young beetles emerging from the ball of dung, from which they mistakenly inferred that the female beetle was able to reproduce without needing a male. From this, they drew parallels with their god Atum, who also begat children alone.
Scarabaeus sacer was the species which first piqued the interest of William Sharp Macleay and drew him into a career in entomology.
Scarabaeus sacer was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae, the starting point of zoological nomenclature. It has since been treated by "the vast majority of authors" as the type species of the genus Scarabaeus, even though strict application of the International Code of Zoological Nomenclature would require Scarabaeus hercules (now usually called Dynastes hercules) to be the type species, following Pierre André Latreille's 1810 type designation.
Friday, February 11, 2011
Saturday, February 05, 2011
Photograph by Jennifer Kiewit, Your Shot
Often mistaken for a jellyfish, the Portuguese man-of-war is actually made up of a colony of organisms working together. Its tentacles can extend 165 feet (50 meters) below the surface, although 30 feet (10 meters) is more the average.
Friday, February 04, 2011
Jupiter, Earth, and planets found by the Kepler telescope, including the newest (bottom row).
Diagram courtesy Tim Pyle, NASA
NASA's Kepler space telescope has uncovered six new planets huddled around a sunlike star—odd worlds that astronomers have dubbed mini-Neptunes, scientists announced Wednesday.
Five of the new planets are closer to their parent star than Mercury is to the sun. The sixth world lies farther out, within a region that would fit inside the orbit of Venus.
"This is the most closely packed known planetary system," said study co-author Jonathan Fortney, an astronomer with the Lick Observatory at the University of California, Santa Cruz.
The planets are relatively small—ranging from roughly 2 to 4.5 times Earth's radius—but they are also surprisingly lightweight, indicating they are made mostly of gases. Based on their densities, four of the planets appear to have thick atmospheres of hydrogen and helium.
The two planets closest to the star have higher densities, suggesting these bodies have atmospheres of mostly water, with just a thin skin of hydrogen and helium.
Finding so many planets around the same star and being able to calculate their properties is a scientific boon, Fortney said. Like paleontologists studying related dinosaur species, astronomers can look at multiple worlds that were born together to get a better understanding of planetary transformations.
"We can do comparative science and ... we can think about how the evolution of the planets has diverged over time," he said.
New Planets Found Via Orbital Dance
The Kepler space telescope was designed to look for Earth-size planets that transit—or pass in front of—their host stars, as seen from Earth.
"We're basically targeting 100,000 to 150,000 stars next to the constellation Cygnus," said Fortney, who is a member of the Kepler science team. "Kepler just stares at that patch of sky unblinking for four years."
With enough time, astronomers can tease out periodic dips in the light from stars as planets pass. (Find out how you can help hunt for planets using Kepler.)
Fortney and colleagues found six signature dips in light from a star called Kepler-11, about 2,000 light-years away. The star is almost the same size, temperature, and brightness as our sun: "It's very much like a solar twin," Fortney said.
At such a distance, though, the star is very dim, making it hard for astronomers to use other planet-hunting techniques to verify the find. Instead the Kepler team confirmed the discoveries using a method called transit timing variations, or TTV.
"Think about one planet that transits," Fortney said. "If its orbital period is ten days, every ten days it will pass in front of the parent star. But if multiple planets transit, they'll affect each other [via gravity]. A planet may transit early or late."
Similar calculations of planets affecting each other's orbital timing are what allowed French and German astronomers to find Neptune in 1846.
The outermost planet in our solar system, Neptune was barely visible to telescopes of the time, and those who could see it thought it was a star. But astronomers knew that Uranus wasn't orbiting as it should, based on laws of physical motion.
Uranus's odd orbit led mathematician Urbain Joseph Le Verrier to predict Neptune's position and mass to account for the discrepancies.
In the case of the Kepler-11 star, the gravity-driven choreography of dips in starlight is almost certainly the product of multiple planets, the team concluded. Further studies, detailed this week in the journal Nature, allowed astronomers to calculate with significant accuracy the masses, positions, sizes, and densities of five of the new worlds.
The sixth planet is far enough away from its siblings that it doesn't affect their orbital dance. Instead astronomers had to run through a suite of calculations to be sure the planet exists. While the team is confident it's there, they weren't able to tease out as many details about the outlying world.
"We know the radius is about 3.6 times that of Earth," Fortney said, "and it's probably less than 30 Earth masses."
"Super Earth" Among New Planets?
The new planetary sextet is remarkably similar to another tight-knit set of worlds found around the sunlike star HD 10180, which was announced last fall. That star lies a mere 127 light-years from Earth.
A team of scientists based in Europe found five Neptune-like worlds close to the star and a larger sixth planet farther out.
They also saw a faint signature of a much smaller world very close to the star that may be a "super Earth"—a rocky planet much larger than our own.
One key difference between the two newfound systems is that "the 'packing' is much more pronounced in the new Kepler system," HD 10180 study leader Christophe Lovis, an astronomer with the Observatory of Geneva in Switzerland, said in an email.
"At first glance I was very surprised that such a system could be dynamically stable on the long term," he said. "Planet masses in the Kepler system are lower than in HD 10180 ... which probably makes it possible to have an even more compact configuration."
Lovis and colleagues had found the planets around HD 10180 using the High Accuracy Radial velocity Planet Searcher, or HARPS, instrument in Chile. The radial-velocity method measures wobbles in starlight caused by the gravitational tugs of orbiting bodies.
"The fact that HARPS and Kepler, using different techniques, find similar things is reassuring in itself and shows how complementary both approaches can be."
Lovis notes, however, that he'd prefer to have the planetary properties of the Kepler-11 system confirmed by other techniques.
"In this particular case, radial velocities would be helpful to measure the masses, probably more precisely than is feasible with TTV," he said. The problem is that the Kepler-11 star "is almost too faint for precise radial velocity followup and would require a lot of telescope time.
"This will remain the main contrast between the Kepler survey and a typical radial velocity survey like the HARPS one: Kepler looks at tens of thousands of distant stars, whereas HARPS looks at a few hundred nearby, bright stars."
Even More New Planets Waiting for Discovery?
For now astronomers aren't sure whether the Kepler-11 system hosts any rocky Earthlike worlds like the one circling HD 10180.
"It's possible that there are smaller planets that we haven't been able to see yet," said Fortney, co-author of the new Kepler study.
"With a few more years of data, one may emerge. It's also possible that TTV will show us there's another planet in the system that doesn't transit. ... "
What the existing data do reveal is that the closely orbiting group around Kepler-11 most likely formed very quickly.
"The way we think that big gas giants like Jupiter form is that first a protocore of ice and rock forms that's like ten [times Earth's mass]. Through its gravity, the core pulls tremendous amounts of gases on top"—notably hydrogen—Fortney said.
In the disk of planet-forming materials, free hydrogen gas lasts just five million years or so before stellar wind—charged particles flowing from the host star—blows it all away. That means the gassy planets around Kepler-11 must have grown up quickly for them to be full of hydrogen.
The Kepler-11 system is also a good case study for what happens to gas planets that move in close to their stars. Based on their sizes and orbital dynamics, the Kepler planets formed farther from the star and migrated inward, the team thinks.
The two mini-Neptunes closest to the star may once have had thicker hydrogen-helium atmospheres like their siblings, but as the two nearer worlds cuddled close to the star, its powerful radiation began to strip away the outer layers.
Looking at the differences between the two sets of planets can help astronomers understand exactly how such worlds lose mass over time.
"In the long term, I think we're going to find that multiplanet systems are common," Fortney added. "With transits limited to seeing edge-on systems, we're always going to be finding the minimum number of planets—a system could have an alignment so that we measure three planets when really there are five."
But overall, he said, "when you see one planet, you're probably going to find another."
Tuesday, January 25, 2011
Photograph courtesy Don Demaria
Off the Florida Keys (map), hundreds of stinging tentacles dangle from a "pink meanie"—a new species of jellyfish with a taste for other jellies.
When pink meanies were first observed in large numbers in the Gulf of Mexico (map) in 2000, they were though to be Drymonema dalmatinum, a species known since the late 1800s and usually found in the Mediterranean Sea, the Caribbean Sea, and off the Atlantic coast of South America.
Recently, though, scientists using genetic techniques and visual examinations have revealed that this pink meanie is an entirely new species—Drymonema larsoni, named after scientist Ron Larson, who did some of the first work on the species in the Caribbean. (Related: "'City of Gonads' Jellyfish Discovered.")
Moreover, the pink meanie appears to be so different from other known scyphozoans, or "true jellyfish," that it forced the scientists to create a whole new animal family, a biological designation two levels above species. The new scyphozoan family—the first since 1921—is called Drymonematidae and includes all Drymonema species.
"They're just off by themselves," said Keith Bayha, a marine biologist at the Dauphin Island Sea Lab in Alabama.
"As we started to really examine Drymonema both genetically and morphologically, it quickly became clear that they're not like other jellyfish and are in their own family."
Bayha and Michael Dawson, an expert on the evolutionary history of marine creatures at the University of California, Merced, detail the new Drymonema jellyfish species and family in the current issue of the journal the Biological Bulletin.
Sunday, January 23, 2011
Fossil of a female Darwinopterus pterosaur preserved together with her egg.
Photograph courtesy Lü Junchang, Institute of Geology, Beijing
Pterosaur parents reproduced more like turtles than birds, according to a new study of a fossilized mother and her egg. The discovery is also the first to allow researchers to conclusively tell the sex of a pterosaur.
The fossils were found next to each other in China's Liaoning Province, once the site of an ancient lake. They appear to belong to a species of pterosaur called Darwinopterus (picture), which lived about 160 million years ago.
Scientists think the adult was an expectant pterosaur mother that somehow broke her left wing, causing her to fall into the lake and drown. The body sank to the bottom and eventually expelled the egg.
"During the decay process, you get a buildup of gases and pressure inside the carcass, and that tends to expel things out," said study co-author David Unwin, a paleontologist at the University of Leicester in the U.K. The egg "didn't go very far. It just came out of the body and sat there."
In addition to the associated egg, the fossil has a larger pelvis than other known Darwinopterus fossils, which is consistent with the animal being a female.
Chemical analysis of the egg suggests that, instead of laying hard-shell eggs and watching over the chicks, as most birds do, pterosaur mothers laid soft-shell eggs, which they buried in moist ground and abandoned.
"It's a very reptilian style of reproduction," Unwin said. "Fertilize the egg, lay the egg, and then go and do whatever you want, without having to worry about what's happening with your offspring."
Based on other fossils of juvenile pterosaurs, scientists think that, unlike birds, pterosaur hatchlings were capable of fending for themselves.
"They looked like tiny adults," Unwin said. "They were highly precocious and could almost certainly fly very soon after hatching."
Pterosaur Eggs Were Soft and Porous?
According to the study, published in this week's issue of the journal Science, the newfound egg contains no traces of calcium carbonate, the mineral responsible for making bird shells hard. By contrast, bird eggs show signs of this mineral throughout their development.
Using magnification, the team could also discern folds in the egg and pore-like holes that might have allowed water to pass through the shell. Taken together, these features suggest the pterosaur egg was relatively soft and had a "parchment like" texture that could expand.
By laying soft eggs that could grow in size, pterosaurs could "make a much smaller investment in terms of material effort," Unwin said.
"As an analogy, imagine you're going on holiday and have to take everything with you, including your food and water. Birds, with their hard-shell eggs, have to pack everything into their eggs, including water.
"Pterosaurs could lay smaller eggs that could absorb water later. That means the environment is contributing to the egg rather than the parent."
Three other fossilized pterosaur eggs are known, and they all showed little or no evidence of calcium carbonate. (See "Fossil Egg Finds Yield Clues to How Pterosaurs Lived.")
What makes this find different is that the other eggs were discovered in isolation, said Mark Witton, a pterosaur researcher and illustrator at the University of Portsmouth in the U.K.
"We could identify in some cases what species the eggs belonged to, but we've never had a pterosaur egg in association with its mother before," said Witton, who was not involved in the new study.
In addition to showing the condition of a pterosaur egg shortly before being laid, the new discovery gives scientists an idea what the size ratio was between pterosaurs and their eggs, said Chatham University paleontologist Michael Habib.
"They seem to be relatively smallish eggs," said Habib, who was not involved in the study. "That's consistent with most egg-laying animals, but they don't all do that. So that's good to know."
Pterosaur Crests Likely a Guy Thing
The new pterosaur fossil is also important because it could finally allow scientists to determine the sex of certain pterosaur species.
Darwinopterus fossils, for example, have been found with and without head crests. Until now, it was unclear whether crested individuals were male or female.
The new fossil, which is obviously a female, lacks a head crest.
Based on this, the team thinks only Darwinopterus males sported head crests, which they may have used to communicate with other members of their species.
A crest could have been used to signal to other males "that 'I'm bigger than you,' or it could be used to tell females 'Here I am, carrying this enormous crest, and I'm a better pterosaur to mate with than the chap next door who's got a smaller crest,'" study co-author Unwin said.
The University of Portsmouth's Witton thinks this interpretation of the head crest's function is "right on the money"—not just for Darwinopterus, but perhaps for most, or even all, pterosaurs.
"That's not to say that they're not going to have other effects," Witton said of the crests. For example, one theory is that the features allowed pterosaurs to expell excess heat during flight.
"If you have a very thin bone sticking out of your head ... you're going to lose some heat out of it," Witton said. "But that's not its main goal. It's just a side effect of the structure."
Saturday, January 22, 2011
Surinam powder puff, pink powder puff, Surinamese stickpea, officiers-kwast.
Family Mimosaceae (Leguminoceae).
A very common, low branching shrub or small tree with multiple trunks, it is native to Suriname it grows up to a height of 15 feet; has evergreen bipinnate, oblong leaves and axillary, compound, showy pink flowers, like a powder puff.
Surinam powder puff has dense foliage and is a fast grower.
A flat pod, first green later brown, contains 5 - 6 seeds; it curls open to release the brown seeds.
This plant is cultivated for its ornamental purposes; it can also be used for bonsai.
photo from flickr.com/photos/jomatt/
PassifloraceaeCommon Names: Passion Fruit, Granadilla, Purple Granadilla, Yellow Passion Fruit
Related Species: Fragrant Granadilla (Passiflora alata), Red Granadilla (P. coccinea), Maypop (P. incarnata), Yellow Granadilla (P. Laurifolia), Sweet Granadilla (P. ligularis), Sweet Calabash (P. maliformis), Banana Passion Fruit (P. mollissima), Giant Granadilla (P. quadrangularis).
Origin: The purple passion fruit is native from southern Brazil through Paraguay to northern Argentina. It has been stated that the yellow form is of unknown origin, or perhaps native to the Amazon region of Brazil, or is a hybrid between P. edulis and P. ligularis. Cytological studies have not borne out the hybrid theory. In Australia the purple passion fruit was flourishing and partially naturalized in coastal areas of Queensland before 1900. In Hawaii, seeds of the purple passion fruit, brought from Australia, were first planted in 1880 and the vine came to be popular in home gardens.
Adaptation: The purple passion fruit is subtropical and prefers a frost-free climate. However, there are cultivars that can take temperatures into the upper 20's (°F) without serious damage. The plant is widely grown in California as far north as San Jose, the Monterey Bay Area and the San Franciso Bay Area. The vines may lose some of their leaves in cool winters. The roots often resprout even if the top is killed. The plant does not grow well in intense summer heat. The yellow passion fruit is tropical or near-tropical and is much more intolerant of frost. Both forms need protection from the wind. Generally, annual rainfall should be at least 35 inches. Passion fruit vines make good container specimens but require maintenance. They perform well indoors.
photo from flickr.com/photos/jomatt/
Photograph by Jennifer Jesse
This photograph was taken in July of 2010 while hiking in a region of Iceland called Landmannalaugar. People come to this area in order to see the colorful rhyolite mountains. During our trip we had come across small amounts of cotton grass along the roads, but I never expected to see such a huge field of it. This image represents what Iceland is all about. Just when you think the landscape can't surprise you anymore, something else even more amazing comes along.
In arid lands, the ability to create freshwater out of thin air would be priceless.
Now a Swiss company, Meteo Systems, is poised to earn a pretty penny in Abu Dhabi with a controversial weather modification system said to be responsible for dozens of rain showers in the desert last summer.
The claim is difficult to verify but certainly has raised a storm of skepticism among many leading weather modification experts.
“As far as I’m concerned I don’t believe these claims,” said Roelof Bruintjes, who heads the National Center for Atmospheric Research’s international weather modification programs. “There’s no scientific basis for this; the physics doesn’t support it.”
(Related: “Planes Create Weird Clouds—And Snow, Rain Fall Out.”)
While typical weather modification efforts—which began in the mid-20th century and continue in nations from the United States to China—make use of natural clouds and attempt to “seed” them to produce precipitation, Meteo Systems purports to create the clouds themselves.
Their system uses arrays of 33-foot (10-meter) electric towers that produce negatively charged ions, according to the company. These ions bind with tiny solid and liquid particles, supercharging the particles’ ability to form clouds and precipitation.
Joseph Golden, a weather modification expert who once chaired the now-defunct Atmospheric Modification Program at the National Oceanic and Atmospheric Administration (NOAA), also has serious doubts that the technique could work.
“This method is inherently incapable of producing clouds out of thin air,” Golden said.
(Related: “China’s Rain-Free Olympics Plan Met With Skepticism.”)
A Long History of Ionization
The Technical University of Munich’s Peter Wilderer, winner of the 2003 Stockholm Water Prize, said people have been attempting ionization techniques for decades.
"The ionization technology was first mentioned in 1890 by [Nikola] Tesla. In 1946 General Electric executed some field trials under the leadership of [Bernard] Vonnegut [brother of novelist Kurt Vonnegut]. Later the technology was used for military purposes in the former Soviet Union."
Wilder added that reviews of radar images suggested to him that ionization could possibly have some effect, under proper meteorological conditions. Despite press reports to the contrary, he has never personally witnessed any rainfall events produced by Meteo Systems.
Show Me the Data
NOAA’s Golden is interested in hearing much more from the scientists trying to make it rain in the desert.
“I put out a challenge to any of those that are involved in this project and making these claims. Show me the data,” he said.
There may be little chance of such transparency in the near-term, however, as Meteo Systems is closely guarding the secrets of the potentially valuable technology the company has dubbed “WEATHERTEC.”
Meteo Systems did not respond to calls and emails from National Geographic News.
The directors of the Max Planck Institute for Meteorology, who have been erroneously linked to the project via media reports, released a statement expressing “distress” that the scientific organization had been associated in any way with the work of Meteo Systems. They added that rainstorms were part of unusual weather patterns in the Middle East last summer.
“Our institute has no connection whatsoever to this work, nor have we been privy to the underlying evidence that the company is using to support its claims,” the statement said.
“We also note that many people have a financial stake in seeing these claims being credibly reported by the media, and that to the extent rain showers in the region were unusual this summer, they accompanied rather unusual weather patterns over the broader region, which certainly had nothing to do with the very localized experiments in Abu Dhabi. One only needs to be reminded of the terrible flooding over neighboring Pakistan.”
NCAR’s Bruintjes noted that the UN-based World Meteorological Organization’s expert team on weather modification research met in Abu Dhabi in March 2010, and issued a report on the state of the science that cautioned against just this type of technology.
“The energy involved in weather systems is so large that it is impossible to create cloud systems that rain,” the WMO report read. “Weather modification technologies that claim to achieve such large-scale or dramatic effects do not have sound scientific basis (e.g. hail cannons, ionization methods) and should be treated with suspicion.”
Golden said people who are simply desperate to fool Mother Nature often pay for modification techniques that are unproven at best, including the hail cannons mentioned in the WMO report. “Farmers invest thousands of dollars in those cannons to suppress hail even though the scientific evidence is that they don’t work,” he said.
Bruintjes put his point bluntly: “The rotation of the Earth, the energy of the sun, and moisture from the oceans cause these things. None of us can change that, and it’s actually good that none of us can change that because we’d likely make a mess of it.”
Thursday, January 20, 2011
Tuesday, January 18, 2011
Photograph by Mihai Iacob
I happened to be in the right place at the right time when I took this picture. The place was Nichols Bridgeway leading to the modern wing of the Art Institute of Chicago, with beautiful views of downtown Chicago, and the time was sunset. I love the architecture, the vibrant city life and the light, all captured in the same frame.
Monday, January 17, 2011
Standar Kompetensi Guru
Guru adalah salah satu jenis jabatan profesional di dalam bidang kependidikan. Sebagai jabatan, guru harus dipersiapkan melalui pendidikan dalam jangka waktu tertentu dengan seperangkat mata kuliah serta beban SKS tertentu sesuai dengan jenjangnya. Pendidikan yang dimaksud adalah untuk mendidik calon guru yang kelak mampu melaksanakan tugas secara profesional. Tugas profesional guru dapat dipilah menjadi empat fungsi sekalipun di dalam praktik merupakan satu kesatuan terpadu saling terkait, mendukung dan memperkuat satu terhadap aspek yang lain. Empat fungsi yang dimaksud adalah: 1) guru sebagai pendidik, 2) guru sebagai pengajar, 3) guru sebagai pelatih, dan 4) guru sebagai pembimbing.
Hasil studi dari pakar pendidikan (Jalal & Mustafa, 2001), menyimpulkan bahwa guru merupakan faktor kunci yang paling menentukan dalam keberhasilan pendidikan dinilai dari prestasi belajar siswa. Reformasi apapun yang dilakukan dalam pendidikan seperti pembaruan kurikulum, penyediaan sarana-prasarana dan penerapan metode mengajak baru, tanpa guru yang bermutu, peningkatan mutu pendidikan tidak akan mencapai hasil yang maksimal.
Kenyataan menunjukkan bahwa masih sebagian besar guru underqualified, tingkat penguasaan bahan ajar dan keterampilan dalam menggunakan metode pembelajaran yang inovatif masih kurang. Untuk itu perlu upaya peningkatan kualitas guru melalui berbagai cara antara lain : penentuan standar kompetensi, uji kompetensi dan sertifikasi guru, penilaian kinerja guru, penataran /pelatihan guru, peningkatan kesejahteraan dan profesionalisme guru, studi lanjut, peningkatan kualitas LPTK penghasil guru, dan lain-lain.
Khusus dalam perumusan standar komptensi guru terlebih dahulu perlu dikaji, dianalisis dan dibahas secara mendalam semua aspek yang berkaitan dengan tugas dan fungsi guru. Tim Penyusun Standar Kompetensi Guru Pemula (SKGP) merumuskan kompetensi guru dalam 4 (empat) rumpun yaitu: (1) Penguasaan Bidang Studi; (2) Pemahaman tentang Peserta Didik; (3) Penguasaan Pembelajaran yang mendidik; dan (4) Pengembangan Kepribadian dan Keprofesionalan. Keempat rumpun tersebut mencerminkan empat standar kompetensi guru yang dijabarkan lagi masing-masing dalam butir-butir kompetensi ( 28 butir kompetensi) selanjutnya diuraikan menjadi indikator yang berfungsi untuk memperjelas butir-butir kompetensi sehingga dapat dirujuk untuk mengembangkan instrumen uji kompetensi guru.
Friday, January 14, 2011
Scientific Name: Aquilegia canadensis
Plant Family: Ranunculaceae
Size: Eastern red columbine is a perennial forb which grows to about 30 to 76 cm (12 to 30 in) in height.
Leaves: Leaves are compound, divided into rounded leaflets which give them the distinctive buttercup appearance.
Flowers: Flowers face downward, with petals which extend backward into long spurs.
Habitat: Eastern red columbine is found in well- lit areas on the edges of woodland areas, on open hillsides and bluffs, and even peat bogs.
Bloom time: May-July
USDA Plants Database (plants.usda.gov)
Flowers have two tiny sepals and four petals. The petals are bisymmetric: the two outer ones are spurred or pouched at the base and curved outwards or backwards at the tip, and the two inner ones are straight and connected at the tip.
The genus Dicentra is distinct from other genera with bisymmetric heart-shaped flowers (Lamprocapnos, Dactylicapnos, Ichtyoselmis, Ehrendorferia) in that the flower stem lacks leaves and all leaves are in a basal rosette.
Each of the two compound stamens is composed of four stamens fused together. The stamens and pistil are held between the inner petals.
Seeds with elaiosomes are borne in long pods.
All parts are poisonous if ingested.
photo from flickr.com
A cactus (plural: cacti, cactuses or cactus) is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptions to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines. Many species are used for ornamental plants, and some are also grown for fodder, forage, fruits, cochineal, and other uses.
Cacti come in a wide range of shapes and sizes. The tallest is Pachycereus pringlei, with a maximum recorded height of 19.2 m, and the smallest is Blossfeldia liliputiana, only about 1 cm in diameter at maturity. Cactus flowers are large, and like the spines arise from distinctive features called areoles.
Lilium columbianum is a lily native to western North America. It is also known as the Columbia Lily or Tiger Lily (sharing the latter common name with several other species in its genus). It occurs in open woods and forest openings from southern British Columbia in Canada south to northern California and east to Idaho and Nevada in the USA.
It grows up to 1.2 m tall, and bears from few to many orange flowers with darker spots. The tepals are 3 to 6 cm long and the flowers are lightly scented. Like many true lilies, the leaves are arranged in whorls around the stem of the plant.
Several Native American tribes in its range used its bitter or peppery-tasting bulbs as a food source. Dried Lilium columbianum is also eaten all around the world but it is not well known for it. Dried whole L. columbianum has a sweet and a sour taste. Unlike many native lilies, it is not particularly rare, but picking the flowers is discouraged as it impairs the ability of the plant to reproduce.
Sunday, January 09, 2011
Excess-3 binary-coded decimal (XS-3), also called biased representation or Excess-N, is a numeral system used on some older computers that uses a pre-specified number N as a biasing value. It is a way to represent values with a balanced number of positive and negative numbers. In XS-3, numbers are represented as decimal digits, and each digit is represented by four bits as the BCD value plus 3 (the "excess" amount):
The smallest binary number represents the smallest value. (i.e. 0 − Excess Value)
The greatest binary number represents the largest value. (i.e. 2^ N+1 − Excess Value -1)
To encode a number such as 127, then, one simply encodes each of the decimal digits as above, giving (0100, 0101, 1010).
The primary advantage of XS-3 coding over BCD coding is that a decimal number can be nines' complemented (for subtraction) as easily as a binary number can be ones' complemented; just invert all bits. In addition, when the sum of two XS-3 digits is greater than 9, the carry bit of a four bit adder will be set high. This works because, when adding two numbers that are greater or equal to zero, an "excess" value of six results in the sum. Since a four bit integer can only hold values 0 to 15, an excess of six means that any sum over nine will overflow.
Adding Excess-3 works on a different algorithm than BCD coding or regular binary numbers. When you add two XS-3 numbers together, the result is not an XS-3 number. For instance, when you add 1 and 0 in XS-3 the answer seems to be 4 instead of 1. In order to correct this problem, when you are finished adding each digit, you have to subtract 3 (binary 11) if the digit is less than decimal 10 and add three if the number is greater than or equal to decimal 10 (thus causing the number to wrap).
Friday, January 07, 2011
Wednesday, January 05, 2011
The giant Pacific octopus grows bigger and lives longer than any other octopus species. The size record is held by a specimen that was 30 feet (9.1 meters) across and weighed more than 600 pounds (272 kilograms). Averages are more like 16 feet (5 meters) and 110 lbs (50 kilograms).
They live to be about four years old, with both males and females dying soon after breeding. Females live long enough to tend fastidiously to their eggs, but they do not eat during this months-long brooding period, and usually die soon afterwards.
Giant Pacific octopuses have huge, bulbous heads and are generally reddish-brown in color. Like the other members of the octopus family, though, they use special pigment cells in their skin to change colors and textures, and can blend in with even the most intricately patterned corals, plants, and rocks.
They hunt at night, surviving primarily on shrimp, clams, lobsters, and fish, but have been known to attack and eat sharks as well as birds, using their sharp, beaklike mouths to puncture and tear flesh. They range throughout the temperate waters of the Pacific, from southern California to Alaska, west to the Aleutian Islands and Japan.
Highly intelligent creatures, giant Pacific octopuses have learned to open jars, mimic other octopuses, and solve mazes in lab tests. Their population numbers are unknown, and they do not currently appear on any lists of endangered or vulnerable animals. However, they are sensitive to environmental conditions and may be suffering from high pollution levels in their range.
- Average life span in the wild:3 to 5 years
- Size:9.75 to 16 ft (3 to 5 m)
- Weight:22 to 110 lbs (10 to 50 kg)
- Did you know? The appendages of octopuses are called arms, not tentacles.
- Size relative to a 6-ft (2-m) man:
A halo (ἅλως; also known as a nimbus, icebow or Gloriole) is an optical phenomenon produced by ice crystals creating colored or white arcs and spots in the sky. Many are near the sun or moon but others are elsewhere and even in the opposite part of the sky. They can also form around artificial lights in very cold weather when ice crystals called diamond dust are floating in the nearby air.
There are many types of ice halos. They are produced by the ice crystals in cirrus clouds high (5–10 km, or 3–6 miles) in the upper troposphere. The particular shape and orientation of the crystals is responsible for the type of halo observed. Light is reflected and refracted by the ice crystals and may split up into colors because of dispersion. The crystals behave like prisms and mirrors, refracting and reflecting sunlight between their faces, sending shafts of light in particular directions.
Atmospheric phenomena such as halos were used as part of weather lore as an empirical means of weather forecasting before meteorology was developed.
Other common optical phenomena involving water droplets rather than ice crystals include the glory and the rainbow.
photo from 2.bp.blogspot.com