Silk Maker Eight-legged wonder

All spiders are predatory eight-legged creatures that have organs to spin silk at the back ends of their bodies. They are the largest part of the arachnid family, a group that also includes scorpions and ticks. Spiders all have the ability to bite with venom-injecting fangs to kill prey and nearly all of them are poisonous (even if it's just a little).
Beyond that, there are many different kinds of spiders just about 40,000 types living in all continents except for Antarctica.

Curiosity lands safely on Mars

Curiosity has phoned home from the dusty surface of Mars.
Radio signals and images received at 10:32 p.m. PDT by NASA's Jet Propulsion Laboratory confirm that the rover has reached Mars' Gale Crater, Curiosity's intended destination after an 8.5-month journey of 567 million kilometers.
Scientists and engineers packed into the JPL mission control room erupted in cheers upon receiving word that the one-ton, six-wheeled rover had survived a complicated sequence of maneuvers that ferried the spacecraft from the top of the Martian atmosphere to the floor of the crater a descent covering 640 kilometers in just seven minutes.
Dubbed "seven minutes of terror" by NASA engineers, Curiosity's touchdown was the interplanetary equivalent of a high-flying, hypersonic circus act, a performance that included firing 76 pyrotechnic charges, dropping 150 kilograms of tungsten, deploying a massive parachute and being lowered to the planet's surface from a rocket-powered sky crane.
“It's like us launching out of Kennedy Space Center, sending something here to the Rose Bowl, and having it land on the 50-yard line on a Frisbee,” said NASA Administrator Charles Bolden.
Like any considerate traveler, the rover's first task after phoning home with news of its safe arrival was to send pictures. A thumbnail image from Curiosity, relayed through the Mars Odyssey Orbiter, depicted one of the rover's wheels resting on Mars.
Now, the rover's journey on the Red Planet can begin, a trek that will take it from the floor of Gale Crater to the slopes of Mount Sharp, the massive mountain rising from the crater's depths. There, this most advanced rover ever will search for organic compounds and signs of life-friendly environments, while reading in the crater's layers a story of Martian history. All along the way, the rover will stamp “JPL” into Mars' reddish sands in Morse code, a message engineers imprinted into its tire treads.
Landing Curiosity successfully is “one of the greatest feats in planetary exploration ever,” says Doug McCuistion, director of NASA's Mars Exploration Program. “It shows the leadership that the United States has had in the exploration of Mars.”
The $2.5 billion rover, probably the last mission of its size to launch in this decade, is crucial for the continuing success of NASA's Mars program. “Our nation has had a continuous presence on Mars for 15 years,” says Charles Elachi, director of the Jet Propulsion Laboratory. “It is a great day; it is a great moment.”
Curiosity's experiments will take several steps toward determining if Mars' early environment was warmer and wetter billions of years ago, as scientists suspect, and answering the question of whether life ever evolved on the planet.
“One of the main reasons for going there is to figure out whether life ever started,” said Michael Meyer, lead scientist for NASA's Mars Exploration Program. “My conclusion would be that life is easy, it's a natural process, and that the universe is just littered with places that support life.”

Did You Know? Why are we obsessed with Mars?

As one of our closest and most familiar neighbours, the Red Planet has served as the source of legends since the first storytellers slept under the stars. With its 24.6-hour day and snowy polar caps, Mars is really the only place that looks promising for life whether alien or an outpost for humans. In modern times, that makes it a perfect slate for allegories about human behavior, from the recently deceased sci-fi author and space visionary Ray Bradbury's critiques of American culture to Kim Stanley Robinson's sci-fi books on the ecological and sociological sustainability on Mars.

Bio-engineered jellyfish

Using rat heart cells and silicone polymer, researchers have bioengineered a "jellyfish" that knows how to swim.
The odd jellyfish mimic, dubbed a "Medusoid" by its creators, is more than a curiosity. It's a natural biological pump, just like the human heart. That makes it a good model to use to study cardiac physiology, said study researcher Kevin Kit Parker, a bioengineer at Harvard University.
"The idea is to look at a muscular pump other than the heart or other muscular organ and see if there are some fundamental similarities, or design principles, that are conserved across them," Parker told LiveScience. "This study revealed that there are."
Building a jelly: Jellyfish propel themselves with a pumping action, as anyone who has ever watched them float around an aquarium tank can attest. Parker was looking for a way to tackle questions about the heart that aren't well understood when he saw some jellyfish in a display in 2007.
"I thought, 'I can build this,'" he said.
The ingredients were rat heart muscle cells and a thin silicone film. ("The world needs less rats and more jellyfish, so I thought it would be cool to do a one-for-one swap," Parker joked.) Along with researchers from the California Institute of Technology, he and his team engineered the cells and silicone in a pattern that mimicked the structure of a real jellyfish. They then stuck the creature in a tank full of electrically conducting fluid and zapped it with current.

Autobiographical memory

UC Irvine scientists have discovered intriguing differences in the brains and mental processes of an extraordinary group of people who can effortlessly recall every moment of their lives since about age 10.
The phenomenon of highly superior autobiographical memory -- first documented in 2006 by UCI neurobiologist James McGaugh and colleagues in a woman identified as "AJ" -- has been profiled on CBS's "60 Minutes" and in hundreds of other media outlets. But a new paper in the peer-reviewed journal Neurobiology of Learning & Memory's July issue offers the first scientific findings about nearly a dozen people with this uncanny ability.
All had variations in nine structures of their brains compared to those of control subjects, including more robust white matter linking the middle and front parts. Most of the differences were in areas known to be linked to autobiographical memory, "so we're getting a descriptive, coherent story of what's going on," said lead author Aurora LePort, a doctoral candidate at UCI's Center for the Neurobiology of Learning & Memory.
Surprisingly, the people with stellar autobiographical memory did not score higher on routine laboratory memory tests or when asked to use rote memory aids. Yet when it came to public or private events that occurred after age 10½, "they were remarkably better at recalling the details of their lives," said McGaugh, senior author on the new work.
"These are not memory experts across the board. They're 180 degrees different from the usual memory champions who can memorize pi to a large degree or other long strings of numbers," LePort noted. "It makes the project that much more interesting; it really shows we are homing in on a specific form of memory."
She said interviewing the subjects was "baffling. You give them a date, and their response is immediate. The day of the week just comes out of their minds; they don't even think about it. They can do this for so many dates, and they're 99 percent accurate. It never gets old."

Stocks plunge

Prices of most shares on the country's premier bourse witnessed a fall during the first two hours of trading on Monday.
DGEN, the general index of the Dhaka Stock Exchange, shed 16 points to reach 4,219 at 1:00pm when the report was filed.
Of the issues traded, 186 declined, 43 advanced and 13 remained unchanged.
Total trade equalled 53,448 while total trade value reached Tk 189 crore.
On Sunday, the DGEN rose 94 points to reach 4,236 points.

Egyptian President Mohammed Morsi has said his move to order the retirement of two of the country's top generals was for "the benefit of this nation".
He was speaking after replacing the powerful head of the armed forces, Field Marshal Mohamad Hussein Tantawi, and Chief of staff Sami Annan.
Morsi also said a constitutional declaration aimed at curbing presidential powers had been cancelled.
Morsi, who was elected in June, is a member of the Muslim Brotherhood.
Relations between Islamists and the military have been increasingly tense since the fall of President Hosni Mubarak last year amid mass street protests.
'Holy mission'
"The decisions I took today were not meant ever to target certain persons, nor did I intend to embarrass institutions, nor was my aim to narrow freedoms," Morsi said during a speech to mark the Muslim fasting month of Ramadan.
Kevin Connolly
Middle East correspondent
As he took office it seemed President Mohammed Morsi would be governing within narrow limits set by Egypt's generals - who had exercised power behind the throne for decades and then exercised it directly in the months since the fall of Hosni Mubarak.
But it is possible Morsi's opponents may have underestimated him.
Egypt's army was unprepared for a recent attack on a security base in the Sinai desert by Islamic militants in which 16 soldiers died.
Morsi appears to be seizing on that failure - which shocked ordinary Egyptians - to move against two key members of the high command.
It may be that the move has been co-ordinated secretly with other influential generals behind the scenes but for now, no-one can be sure.
"I did not mean to send a negative message about anyone, but my aim was the benefit of this nation and its people," he said.
The president also praised the armed forces, saying they would now focus "on the holy mission of protecting the nation".
It was announced earlier that a career army officer, Gen Abdel-Fattah al-Sisi, would replace Field Marshal Tantawi as both armed forces chief and defence minister.
Field Marshal Tantawi, 76, has not yet indicated whether he accepts the moves.
However Gen Mohamed el-Assar, a member of the Supreme Council of the Armed Forces (Scaf), told Reuters news agency the decision had been "based on consultation with the field marshal, and the rest of the military council".
A presidential spokesman said Gen Annan and Field Marshal Tantawi had been appointed as presidential advisers and were given Egypt's highest state honour, the Grand Collar of the Nile.
Islamist raid
BBC Middle East correspondent Kevin Connolly says the dismissal of senior military officers will be seen by Egyptians as a decisive move in a struggle for real power between the country's newly elected politicians and the generals who have exercised power for many years.
As head of Scaf, Field Marshal Tantawi became Egypt's interim ruler after President Mubarak was ousted following last year's mass protests.
Under the interim constitutional declaration issued by Scaf before Morsi was sworn in, the president could not rule on matters related to the military - including appointing its leaders.
The council also dissolved parliament, which is dominated by the Muslim Brotherhood.
Tensions between the presidency and Scaf were further exacerbated after Islamist militants in the Sinai peninsula killed 16 border guards last week, in a raid that embarrassed the military.
The president, whose own Brotherhood movement renounced violence long ago, sacked Egypt's intelligence chief and two senior generals following the attack.

Syrian rebels call for no-fly zone

Syrian rebels fighting to oust President Bashar al-Assad need the protection of no-fly zones and safe havens patrolled by foreign forces near the borders with Jordan and Turkey, a Syrian opposition leader said.
Battles raged on Sunday in the northern city of Aleppo, where tanks, artillery and snipers attacked rebels in the Saif al-Dawla district next to the devastated area of Salaheddine.
Syrian civilians desperate to check on their homes pushed into fluid front lines around Salaheddine, even as sniper fire cracked out and rebels warned them to stay away.
Abdelbasset Sida, head of the Syrian National Council, said the United States had realised that the absence of a no-fly zone to counter Assad's air superiority hindered rebel movements.
He was speaking a day after US Secretary of State Hillary Clinton said her country and Turkey would study a range of possible measures to help Assad's foes, including a no-fly zone, although she indicated no decisions were necessarily imminent.
"It is one thing to talk about all kinds of potential actions, but you cannot make reasoned decisions without doing intense analysis and operational planning," she said after meeting Turkish Foreign Minister Ahmet Davutoglu in Istanbul.
Though any intervention appears to be a distant prospect, her remarks were nevertheless the closest Washington has come to suggesting direct military action in Syria.
"There are areas that are being liberated," Sida told Reuters by telephone from Istanbul. "But the problem is the aircraft, in addition to the artillery bombardment, causing killing, destruction."
He said the establishment of secure areas on the borders with Jordan and Turkey "was an essential thing that would confirm to the regime that its power is diminishing bit by bit".
A no-fly zone imposed by Nato and Arab allies helped Libyan rebels overthrow Muammar Gaddafi last year. The West has shown little appetite for repeating any Libya-style action in Syria, and Russia and China strongly oppose any such intervention.
Insurgents have expanded territory they hold near the Turkish border in the last few weeks since the Syrian army gathered its forces for an offensive to regain control of Aleppo, Syria's biggest city and economic hub.
TANKS ADVANCE
Rebels who seized swathes of the city three weeks ago have been fighting to hold their ground against troops backed by warplanes, helicopter gunships, tanks and artillery.
One rebel commander named Yasir Osman, 35, told Reuters tanks had advanced into Salaheddine, despite attempts to fend them off by 150 fighters he said were short of ammunition.
"Yesterday we encircled the Salaheddine petrol station, which the army has been using as a base, and we killed its commander and took a lot of ammunition and weapons. This ammunition is what we are using to fight today," he said.
Aleppo and the capital Damascus, where troops snuffed out a rebel offensive last month, are vital to Assad's struggle for the survival of a ruling system his family and members of his minority Alawite clan have dominated for four decades.
Assad has suffered some painful, but not yet fatal, setbacks away from the battlefield, losing four of his closest aides in a bomb explosion on July 18 and suffering the embarrassment of seeing his prime minister defect and flee to Jordan last week.
Syrian state television showed Assad swearing in Wael al-Halki on Saturday to replace Riyad Hijab, who had only spent two months in the job. Halki is a Sunni Muslim from the southern province of Deraa where the uprising began 17 months ago.
The deputy police commander in the central province of Homs was the latest to join a steady trickle of desertions, said an official in the opposition Higher Revolution Council group.
"Brigadier General Ibrahim al-Jabawi has crossed into Jordan," the official told Reuters from Amman.
At least 20 people were killed on Sunday in the second day of an armored offensive to retake the northern Damascus suburb of al-Tel from rebels, opposition activists said.
Heavy artillery barrages were hitting the Sunni Muslim town as loyalist troops made a renewed push after an attempt to storm Tel on Saturday was repelled, several activists and Free Syrian Army sources in the area said.
The Arab League said it had postponed a meeting of Arab foreign ministers scheduled for Sunday to discuss the Syria crisis and to select a replacement for Kofi Annan, the United Nations-Arab League envoy, and would set a new date.
Deputy Arab League chief Ahmed Ben Helli told Reuters the meeting was delayed because of a minor operation undergone by Saudi Arabian Foreign Minister Prince Saud al-Faisal.
Saudi Arabia, Qatar and Turkey are the leading regional supporters of the Syrian opposition. Assad's main backers are Iran and Lebanon's Shi'ite Hezbollah movement.

4 held with 81 fake passports

Detective Branch of police seized 81 fake passports and arrested four people at Matuail in the capital Saturday midnight.
The arrestees are Firoz Hossain, 30, Rajib Hossain, 25, Yunus Mollik, 30 and Mohamad Sumon, 20.
On secret information, detectives raided Dakshinpara of Matuail and arrested the four along with the fake passports, said Deputy Commissioner Masudur Rahman, in-charge of Media and Community Service of Dhaka Metropolitan Police.
The gang stole passports with visas and fixed photographs of other persons in exchange of money, the DC said.

Iran earthquake toll rises to 250

Rescuers in Iran are searching through the rubble of collapsed buildings for survivors from two strong earthquakes which left at least 250 people dead.
The 6.4 and 6.3 quakes struck near Tabriz and Ahar Saturday afternoon, and more than 1,800 are believed injured, many in outlying villages.
Thousands have been spending the night in emergency shelters or in the open.
Relief agencies are trying to provide the survivors with tents, bread and drinking water.
Reports say phone lines to many villages have been cut off, confining rescuers to radio contact and, analysts said, probably masking the true scale of casualties.
"The quake has created huge panic among the people," one resident of Tabriz told the BBC. "Everyone has rushed to the streets and the sirens of ambulances are everywhere."
The towns of Haris and Varzaqan in East Azerbaijan province in north-western Iran were among those that suffered casualties, local crisis committee chief Khalil Saei told state TV according to the Associated Press.
State TV said at least six villages were totally flattened, with 60 other villages sustaining damage ranging from 50% to 80%.
'My family is terrified'
Dozens of rescue workers have been sent to the region, but relief efforts have been limited overnight.
"Unfortunately there are still a number of people trapped in the rubble but finding them is very difficult because of the darkness," news agency Fars quoted national emergency head Gholam Reza Masoumi as saying.
Almost all deaths seem to have been confined to rural areas, local disaster officials said - probably because buildings in the cities are more sturdily constructed.
An Iranian Red Crescent official estimated that 16,000 people had been given emergency shelter after they were forced to leave their homes.
President Mahmoud Ahmadinejad's office posted a statement on its website expressing condolences to those in the disaster zone and calling on authorities to "mobilise all efforts to help the affected populations," the AFP news agency reports.
A provincial official has warned people in the region to stay outdoors overnight because of the risk of aftershocks.
"My family is really terrified. It is night time now but we cannot sleep," Tabriz resident Amina Zia told the BBC.
"This earthquake was... very strong and violent.
"There were around 10 aftershocks, which lasted a total of 10 minutes."
The second earthquake struck just 11 minutes after the first, said the US Geological Survey.
Iran straddles a major geological fault line, making it prone to seismic activity. In 2003 an earthquake in the city of Bam left 25,000 people dead.