The largest known predatory dinosaur to roam the Earth was nine feet longer than the world’s biggest T. Rex specimen.
Scientists report that Spinosaurus aegyptiacus also appears to have been the first truly semiaquatic dinosaur.
New fossils of the massive Cretaceous-era predator reveal it adapted to life in the water some 95 million years ago, providing the most compelling evidence to date of a dinosaur able to live and hunt in an aquatic environment.
Image: The Black Plague killed half of Europe’s population. In Kutna Hora in Czech Republic, the skulls of plague victims were fashioned into a chapel. (Martin Moos/ Getty)
Bodies were piled into mass graves—sometimes five bodies high. Towns were destroyed, families wiped out. As the Black Plague marched through Europe in the 14th century, it decimated half of the continent’s population.
Few were spared from loss.
Six hundred years later, the pestilence reared its head again. This time it killed around 10 million people in the late 19th century.
It was in this zenith that the murderer was uncovered.
In 1894, Swiss doctor Alexandre Yersin identified that the bacteria, Yersinia pestis, were the destructive beasts.
While stories of this scourge have largely been relegated to history books, we have never gotten rid of this disease.
Is your feline friend purring because he’s happy, or could it be something else? (Photo: Travis Modisette/flickr)
It’s easy to assume that cats purr because they’re happy. After all, when your kitty contentedly curls up in your lap for some well-deserved scratches and rubs, she’s obviously one happy feline.
However, cats also purr when they’re frightened or feel threatened, such as during a visit to the vet. Veterinarian Kelly Morgan equates this reaction with smiling. “People will smile when they’re nervous, when they want something, and when they’re happy, so perhaps the purr can also be an appeasing gesture,” Morgan told WebMD.
A cat’s purr begins in its brain. A repetitive neural oscillator sends messages to the laryngeal muscles, causing them to twitch at a rate of 25 to 150 vibrations per second. This causes the vocal cords to separate when the cat inhales and exhales, producing a purr. But not all cats can purr. Domestic cats, some wild cats and their relatives — civets, genets and mongooses — purr, and even hyenas, raccoons and guinea pigs can purr.
However, cats that purr can’t roar, and cats that roar can’t purr because the structures surrounding roaring cats’ larynxes aren’t stiff enough to allow purring. Roaring cats evolved this way for good reason. These cats move around a lot to catch prey, so they developed their roar to protect their prides and their territory.
Purring cats, on the other hand, are smaller and more likely to be loners that don’t have to compete with each other for prey. They use scent to mark territory and don’t need a far-reaching way to communicate.
However, your cat may also purr to communicate with you. According to researchers at the University of Sussex, domestic cats can hide a plaintive cry within their purrs that irritates their humans while appealing to their nurturing instincts.The team examined the sound spectrum of 10 cats’ purrs and found an unusual peak in the 220- to 520-hertz frequency range embedded in the lower frequencies of the usual purr. Babies’ cries have a similar frequency range at 300 to 600 hertz.
Karen McComb, who headed the study, said cats may be exploiting “innate tendencies in humans to respond to cry-like sounds in the context of nurturing offspring.
”Why would your feline do this? “Cats apparently learn to do this to get people to feed them sooner,” said veterinarian Benjamin L. Hart.Cats’ purrs are more than simply a way to communicate though. Scientists like Elizabeth von Muggenthaler, a bioacoustics researcher, believe that cats also purr to heal themselves.
But now comes a surprise. When students went to downtown Seattle to count bird species, within the first 10 to 15 minutes they spotted pigeons, finches, sparrows, crows and an occasional hummingbird.
Their count was 10 to 15 different kinds of birds — not many, but they expected that.
When they went the other way (to the far edge of the metropolitan area near the Cascade Mountains, where there is mostly forest, protected parks, reservoirs, and humans are sparse), in the first 10 to 15 minutes, they found a very different set of birds (woodpeckers, wrens, warblers, chickadees).
In all, 20 different species — more, but not many more than downtown.
Then they went to the in-between zone, the Seattle suburbs, where they expected an in-between count, something like 12 different kinds of birds. But that’s not what happened.
Birds in the suburbs.
“We were astonished,”
Marzluff writes. The suburban count (again in the first 10 minutes) was “30 or more species,” says Marzluff, some from downtown, some from the mountains, but also spectacularly new samples of “violet-green swallows, willow flycatchers, killdeer, orange crowned warblers, American goldfinches, and Bewick’s wrens … [plus a few] white crowned sparrows.”
The suburbs produced, by far, the most biologically diverse collection of birds.
What? This region that’s all sprawl, a hodgepodge of strip malls, yards, highways, parking lots, hedges, fences, is “a mecca for birds”? More than a forest? No way, thought Marzluff. So he counted again. Then again.
And after checking and compiling “more than 100 locations in and around Seattle,” he writes, he and his team discovered “a consistent, but unexpected relationship between the intensity of development and bird diversity.”
To his great surprise, Marzluff concluded that the “greatest diversity was not in the most forested setting. Instead, bird diversity rose quickly from the city center to the suburbs and then dropped again in the extensive forest that eases Seattle into the high Cascades.”
If you plotted it on a graph, bird biodiversity looks like this …
Louis Pasteur was born in Dole France, married to Marie Laurent and had five children.
Three of his children died of typhoid fever, maybe leading to Pasteur’s drive to save people from disease.
He graduated in 1842 from Besancon College Royal de la Franche with honors in physics, mathematics, Latin, and drawing. Louis Pasteur later attended Ecole Normale to study physics and chemistry, specializing in crystals.
In his early research Pasteur worked with the wine growers of France, helping with the fermentation process to develop a way to pasteurize and kill germs.
He was granted U.S. patent 135,245 for “Improvement in Brewing Beer and Ale Pasteurization.”
Pasteur then worked within the textile industry finding a cure for a disease affecting silk worms.
He also found cures for chicken cholera, anthrax and rabies.
The Pasteur Institute
The Pasteur Institute was opened in 1888. During Louis Pasteur’s lifetime it was not easy for him to convince others of his ideas, controversial in their time but considered absolutely correct today.
Pasteur fought to convince surgeons that germs existed and carried diseases, and dirty instruments and hands spread germs and therefore disease. Pasteur’s pasteurization process killed germs and prevented the spread of disease.
The Germ Theory of Disease
Louis Pasteur’s main contributions to microbiology and medicine were; instituting changes in hospital/medical practices to minimize the spread of disease by microbes or germs, discovering that weak forms of disease could be used as an immunization against stronger forms and that rabies was transmitted by viruses too small to be seen under the microscopes of the time, introducing the medical world to the concept of viruses.
The quagga (/ˈkwɑːxɑː/) (Equus quagga quagga) is an extinct subspecies of the plains zebra that lived in South Africa. The Image above is the only known photograph of a Quagga.
It was long thought to be a distinct species, but recent genetic studies have shown it to be the southernmost subspecies of the plains zebra.
It is considered particularly close to Burchell’s zebra.
Its name is derived from its call, which sounds like “kwahaah”.
The quagga is believed to have been around 257 cm (8 ft 5 in) long and 125–135 cm (4 ft 1 in–4 ft 5 in) tall at the shoulder. It was distinguished from other zebras by its limited pattern of primarily brown and white stripes, mainly on the front part of the body.
The rear was brown and without stripes, and therefore more horse-like. The distribution of stripes varied considerably between individuals. Little is known about its behaviour but it may have gathered into herds of 30–50 individuals.
Quaggas were said to be wild and lively, yet were also considered more docile than Burchell’s zebra (see above). They were once found in great numbers in the Karoo of Cape Province and the southern part of the Orange Free State in South Africa.
Since Dutch settlement of South Africa began, the quagga was heavily hunted, and it competed with domesticated animals for forage. While some individuals were taken to zoos in Europe, breeding programs were not successful.
The last wild population lived in the Orange Free State, and the quagga was extinct in the wild by 1878. The last captive specimen died in Amsterdam on 12 August 1883.