Wednesday, October 28, 2009

Swine influenza

Swine influenza (also called swine flu, hog flu, pig flu and sometimes, the swine) is an infection by any one of several types of swine influenza virus. Swine influenza virus (SIV) is any strain of the influenza family of viruses that is endemic in pigs. As of 2009, the known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H3N1, H3N2, and H2N3.

Swine influenza virus is common throughout pig populations worldwide. Transmission of the virus from pigs to humans is not common and does not always lead to human influenza, often resulting only in the production of antibodies in the blood. If transmission does cause human influenza, it is called zoonotic swine flu. People with regular exposure to pigs are at increased risk of swine flu infection. The meat of an infected animal poses no risk of infection when properly cooked.



Swine influenza was first proposed to be a disease related to human influenza during the 1918 flu pandemic, when pigs became sick at the same time as humans. The first identification of an influenza virus as a cause of disease in pigs occurred about ten years later, in 1930. For the following 60 years, swine influenza strains were almost exclusively H1N1. Then, between 1997 and 2002, new strains of three different subtypes and five different genotypes emerged as causes of influenza among pigs in North America. In 1997–1998, H3N2 strains emerged. These strains, which include genes derived by reassortment from human, swine and avian viruses, have become a major cause of swine influenza in North America. Reassortment between H1N1 and H3N2 produced H1N2. In 1999 in Canada, a strain of H4N6 crossed the species barrier from birds to pigs, but was contained on a single farm.

The H1N1 form of swine flu is one of the descendants of the strain that caused the 1918 flu pandemic. As well as persisting in pigs, the descendants of the 1918 virus have also circulated in humans through the 20th century, contributing to the normal seasonal epidemics of influenza. However, direct transmission from pigs to humans is rare, with only 12 cases in the U.S. since 2005. Nevertheless, the retention of influenza strains in pigs after these strains have disappeared from the human population might make pigs a reservoir where influenza viruses could persist, later emerging to reinfect humans once human immunity to these strains has waned.

Reference : Wikipedia.org


Monday, October 26, 2009

Bear

American Black Bear
These bears are often found in national parks, where they raid campsites for food. They have a keen sense of smell, and usually hunt at night. They are smaller and less dangerous than their brown bear cousins.



Asiatic Black Bear
This bear has a broader face than the American black bear and a v-shaped patch of white fur on its chest. They are very good climbers and often climb up trees to catch insect or to reach fruit and honey.


Grizzly Bear
The grizzly bear is one of the largest brown bears in the world. Other members of the brown bear family include the Alaskan brown bear, the American brown bear, and the brown bears of Europe and Asia. Grizzlies can stand more than 10 ft. high on their hind legs. These animals mainly live in forests, and will eat almost anything including fruit, deer, and fish, and have even been witnessed killing other bears.



Polar Bear
The polar bear is the world''s largest bear. Females can weigh over 650 lbs, while males can weigh more than double that weight. Polar bears are great swimmers, they have been seen in open waters hundreds of miles from the land. Males are active year round, while females usually hibernate in ice dens during the winter. A female polar bear will give birth to their young inside of these ice dens, and then emerge in the spring.



Sun Bear
The sun bear is one of the smallest and most intelligent bears in the world. They live in the tropical forests of Southeast Asia, and feed on fruit and a variety of animals. Sun bears sleep during the day in nests they make out of leafy branches. The spend the nights foraging for food.



Sloth Bear
The sloth bear has quite an unusual diet they fed on termites by, sucking them up like a vacuum. Sloths have very powerful feet and long claws.



Spectacled Bear
The spectacled bear is the only bear found in South America. This bear''s fur is mostly black or brown with white spectacles. They are great climbers, and live in warm climates where they don''t need to hibernate.


Fish

A fish is any aquatic vertebrate animal that is typically ectothermic (or cold-blooded), covered with scales, and equipped with two sets of paired fins and several unpaired fins. Fish are abundant in the sea and in fresh water, with species being known from mountain streams (e.g., char and gudgeon) as well as in the deepest depths of the ocean (e.g., gulpers and anglerfish).

Jawless fish: Like we just said, the first fish didn't have jaws. It is tough to eat and even harder to survive in the long run. Even with a mouth and a series of teeth to cling to their food, it's still hard to compete with fish that have jaws and mouths. Some species made it to the modern world. One good example is a Lamprey. These fish suck on the sides of other fish. Not a very exciting life.

Fish with cartilage: In our opinion, though not as advanced as fish with real bones, fish with cartilage are the coolest fish out there.Cartilaginous fish include species of sharks, rays, and skates. Sharks are the ultimate hunters of the ocean.

They are big, fast, and have very sharp teeth that rip their prey apart. Skates and rays are a lot more docile or non-aggressive. They are usually bottom feeders. The bodies of rays and skates have developed large wings that allow them to glide through the water using their tail as a rudder.

Here the Cartilage Fish Soup :



Bony fish with lobe fins: And then the fish with real bones came along. No longer was cartilage the skeleton of choice. Bony fish were able to out-compete most of the fish that had cartilage for skeletons. Scientists classify them into two groups - the LOBE-finned and the RAY-finned. Lobe-finned bony fish include examples such as lungfish and coelacanthus. Until about 30 years ago, scientists thought the coelacanthus was long extinct. One day a fisherman found one in the net and voila!


Bony fish with ray fins: You probably think of these fish when you think of a classic fish. The bony fish with ray shaped fins include goldfish, tuna, and trout, all tasty fish you can eat. Goldfish are for the college guys. They have complex skeletons and are built to move. Some move really fast and are very strong. Something like a tuna can move extremely quickly through the water.