This is SCIENCE IN THE NEWS in VOA
Special English. I'm Bob Doughty.
And I'm Shirley Griffith. This week, we tell about a discovery of
gorillas in the Republic of Congo and the loss of Bengal tigers in Nepal. We also tell about a famous heart surgeon
and what you need to know about your heart.
Deep in the forests in the northern part
of the Republic of Congo, scientists have made a surprising discovery. Researchers discovered more than one hundred
twenty-five thousand critically endangered western lowland gorillas.
nineteen eighties, scientists estimated that the total population of western
lowland gorillas in Central Africa was fewer than one hundred thousand. Since then however, the scientists believed
this number had been reduced by at least half.
They thought the animals were being killed off by hunters and disease,
especially the deadly Ebola virus.
The new population count was the result
of intensive work by the Wildlife Conservation Society, based in New York City,
and scientists of the Republic of Congo. They searched rainforests and swamps,
looking for gorilla nests.
Gorillas build beds, or nests, for
sleeping each night. They use leaves
and other parts of trees. The researchers
use the number of nests they find to help estimate the local gorilla
population. They found some forests had
population densities that were among the highest ever recorded. The researchers studied an area of
forty-seven thousand square kilometers. They announced the results of their
population count at a meeting of the International Primatological Society
Congress in Edinburgh, Scotland.
scientists say the higher number of gorillas is the result of efforts by the
Republic of Congo to take care of its protected areas. The gorillas have also done well because
they live in areas far away from people.
And they have plenty to eat.
Wildlife Conservation Society President Steven Sanderson said the
success of the gorillas is proof that humans can help protect animal species in
danger of disappearing.
lowland gorillas are one of four recognized gorilla subspecies. Other subspecies include mountain gorillas,
eastern lowland gorillas, and Cross River gorillas. The International Union for Conservation of Nature considers
all of the subspecies
to be critically endangered, except for the eastern lowland gorillas. That subspecies is considered endangered.
Researchers at the meeting in Scotland warned
about the dangers that continue to threaten gorillas. They say almost fifty
percent of the world's species of primates are in danger of disappearing,
especially in Asia. This is because the
areas in which they live are being destroyed. And many animals are illegally
hunted as food.
That was some good news about gorillas.
But we have some bad news about tigers.
Three years ago, between twenty and fifty Bengal tigers lived in the
Suklaphanta Wildlife Reserve in Nepal.
But this year, researchers reported evidence of only six to fourteen
tigers. The Nepalese government announced the decrease of the tiger population
last month. The wildlife reserve
measures about thirty thousand hectares.
It is the world's third largest living area for the big cats.
national parks and conservation officials called the situation very serious.
They said illegal hunting is the major cause of tigers disappearing from this
The World Wildlife Fund did most of the
study about the tigers. The findings
were based on pictures taken by camera traps from January to April. The camera traps contain devices that take a
picture when they sense movement in the forest. Researchers used two cameras to
take pictures of the tigers from both sides.
But the cameras also photographed the hunters who killed the tigers and
removed their remains.
Suklaphanta Wildlife Reserve is on the border with India. World Wildlife Fund officials say this makes
it easy to illegally transport protected wildlife. Very little of the tigers' remains are found because all of the
animal's parts are valuable in the illegal wildlife trade.
Miceler heads the World Wildlife Fund's Eastern Himalayas Program. Mister Miceler said that in May, two tiger
skins were seized from the Nepalese border town of Dhangadi. So were thirty-two kilograms of tiger bones.
Mister Miceler says the loss of tigers
is linked to a powerful international criminal group that controls the illegal
wildlife trade. Only about two thousand
to four thousand Bengal tigers survive in the wild.
live in forests in central and south India, Bhutan, and the Himalayan foothills
of India and Nepal. Bengal tigers also
live in China, Bangladesh and Burma. The World Wildlife Fund says populations
of all kinds of tigers have decreased by ninety-five percent over the past one
hundred years. And three kinds of
tigers have disappeared.
American heart surgeon Michael DeBakey died last month. He was ninety-nine
years old. He performed more than sixty
thousand operations during his long career.
As a medical student in nineteen thirty-one, he invented the roller
pump. Years later doctors used it for blood transfusions during heart
operations. The roller pump became a major part of the heart-lung machine. The
machine pumps oxygen-rich blood to the brain and other organs so doctors can
operate on the heart.
DeBakey was a pioneer of open-heart surgery. The name means that doctors open
the chest and perform surgery on the heart. Doctors may or may not open the
heart as well.
DeBakey developed a way to replace or repair blood vessels with Dacron, a
stretchy manmade material. He continued to improve on the process. Today the
DeBakey artificial graft is used around the world. He was also a pioneer in
artificial hearts, heart transplants and recording surgeries on film. During
World War Two in the nineteen forties, he helped develop the Mobile Army
Surgical Hospital, or MASH.
DeBakey saved many lives during his long career as a heart surgeon. One life he
helped save was his own. Two years ago he had a damaged aorta, which carries
blood from the heart to the body. Surgeons repaired it with an operation he
developed long ago.
of hearts, here is some information about that complex organ and how to keep it
healthy. The heart has four parts. As
the heart beats, it pumps blood through these chambers and the blood vessels in
the body. The body is estimated to have at least ninety-six thousand kilometers
of blood vessels. That is about the same as two and a half times around the
Earth. But blood goes the distance in about twenty seconds on its way back to
the heart. Each day the heart pumps about eight thousand liters of blood.
blood feeds the brain and other organs with oxygen and nutrients. It also carries
away carbon dioxide and other waste. The heart pumps by expanding and
contracting of muscle. In a healthy adult, the heart beats an average of
seventy-two times a minute -- about one hundred thousand times a day.
Rates of heart disease started growing
sharply in the second half of the twentieth century. As machines did more and
more work, people did less and less. Not only did physical activity decrease,
but people started eating more processed foods.
say a diet low in fats and high in fruits, vegetables, proteins and whole
grains may help reduce the risk of heart disease. At least thirty minutes a day
of physical activity, enough to work up a sweat, can also help. A good night's
sleep is also important for good health.
Cardiovascular disease is caused by disorders of the
heart and blood vessels. It includes heart attacks, strokes and high blood
pressure. The World Health Organization says there are three major causes of
cardiovascular disease: tobacco use, physical inactivity and an unhealthy diet.
W.H.O. says cardiovascular disease is the world's leading cause of death.
This SCIENCE IN THE NEWS program was
written by Jerilyn Watson, Caty Weaver and Brianna Blake, who also was our producer. I'm Shirley Griffith.
And I'm Bob Doughty. You can read and
listen to our programs at voaspecialenglish.com. Join us
next week for more news about science in VOA Special English.