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Severe winter weather in the UK has worsened, callous rancid more areas of the land as driving snow which caused chaos in the north has at the present stimulated south.

While the picture is beautiful from the air, by ground level Britain's most terrible storm in 30 years is more of an menacing truth.

The south of England is at the present demeanor the brunt with many roads in Hampshire, Berkshire and Kent by a fester, leaving commuters trembling in their cars.

But the neighborhood spirit was prevailing with community walking up and down with flasks offering cups of tea or coffee. Others had bits of food they were sharing with everybody.

Councils are difficult to patent the roads with gritters and snow ploughers are harsh by drive on the major roads.

But it's not much more comfortable intended for persons who stayed by local with prevalent power outages.

Further north, the community of Liverpool heeded warnings not to venture dated into the cold and the city streets were near deserted.
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Added than 8000 schools across the UK give birth to been clogged.

Even the slight blue line proved thumbs down match intended for a thick blanket of white and inhabitant communities give birth to dug in.

Airports were crippled as 240 flights in and dated of Gatwick were cancelled.

Key generous gear across the land were postponed while others went early in fewer than just what the doctor ordered conditions.

And the deep freeze is bringing harmful conditions to much of northern Europe. The army was called dated in eastern Poland to help residents edit rancid as a inhabitant waterway burst its banks and froze on the roads.

The death toll in Poland from the unembellished weather has risen to 122 - many of the victims reported to be on the streets.

And a cold snap mesmerizing the central US is causing problems intended for Florida farmers well developed to rescue summer crops from freezing temperatures. Fruit has been sprayed with a protecting icy layer and covered in plastic to save it from the cold.

A female blacktip shark in Virginia fertilized her own egg without mating with a male shark, new DNA evidence shows. This is the second time scientists have used DNA testing to verify shark parthenogenesis—the process that allows females of some species to produce offspring without sperm.

The female shark, dubbed Tidbit, died during a routine physical exam before the pregnancy was identified.

A necropsy—an animal autopsy—after her death revealed she was carrying a near-term pup fetus that was about 12 inches (30 centimeters) in length.

Tidbit was caught in the wild when she was very young and reached sexual maturity in a tank at the Virginia Aquarium in Virginia Beach, where she lived for eight years.

"The interesting thing about that was there were no male blacktip sharks in the tank for the entire time of her captivity," said Demian Chapman, a researcher with the Institute for Ocean Conservation Science at Stony Brook University in New York.

"So the question is, where does this baby come from?" he asked.

Chapman is the lead author of a study on the female blacktip in the latest issue of the Journal of Fish Biology.

DNA fingerprinting

Chapman and his colleagues generated a DNA fingerprint for the mother shark and her pup fetus with a procedure identical to a human paternity test.

Ordinarily, a shark's DNA contains some genetic material from its mother and some from its father. Tidbit's pup, however, was not ordinary.

"Every part of the fingerprint of the embryo comes from the mother," Chapman said. "In other words, there is no genetic material from a father."

All non-mammal vertebrate species are theoretically capable of parthenogenesis, scientists say. Examples have been documented in komodo dragons , pythons, rattlesnakes, chickens, and turkeys.

Parthenogenesis is not possible in humans because if all the genetic material comes from the mother, certain genes will be switched off, and the embryo won't develop.

"For sharks in captivity, [parthenogenesis] has probably occurred more times than has been documented," says Robert Hueter, director of the Center for Shark Research at Mote Marine Laboratory in Sarasota, Florida.

The question then becomes, is parthenogenesis a type of developmental anomaly or a response to the female shark not having a mate in captivity?

"The fact that only one shark embryo was formed may suggest that this is more a case of an egg developmental aberration rather than a physiological response to the lack of a mate," said Hueter, who was not involved with the study.

No Variation

Normally, an embryo is formed when an egg containing half its chromosomes is fertilized by a sperm containing the other half.

When an egg cell is formed, a plant or female animal also produces three other cells called polar bodies. In the type of parthenogenesis observed in sharks, one of those cells behaves like a sperm and fertilizes the egg.

"But that cell is genetically identical to the egg," Chapman said. "So that's where you lose a lot of genetic variation."

Offspring produced by parthenogenesis are not exact clones of their mothers, however, because the genetic material is mixed differently.

Still, researchers believe the risk of congenital defects increases in animals whose DNA lack genetic variation.

"There's an increased risk of having a weakened immune system and there's a risk of reproductive abnormalities," Chapman said. "But in some cases, they'll be able to survive."

The scientists have not ruled out the possibility that increased stress from the abnormal pregnancy contributed to Tidbit's death.