Dinosaur Dads Took Care of Nest
By Erik Stokstad
ScienceNOW Daily News 18 December 2008
The movie Jurassic Park gave advanced, birdlike dinosaurs a fearsome reputation--swift, intelligent, and deadly. Now it turns out that they had a softer side. Researchers report that males in three species were stay-at-home dads that incubated the eggs in their nests.
There's plenty of evidence to suggest that dinos baby-sat their offspring. A predatory dinosaur called Oviraptor, for example, was discovered in the Gobi Desert in 1993, its fossilized remains protecting a brood of eggs. In addition, dinosaurs' closest living relatives, birds and crocodiles, display nesting behavior: Female crocs guard the eggs, whereas in birds the gender of the stay-at-home-parent depends on the species. But whether male or female dinos had nest duty has remained a mystery.
For the new research, paleontologist David Varricchio of Montana State University in Bozeman compared three species of birdlike dinosaurs--Oviraptor, Citipati, and Troodon--with birds and crocodiles. All three types of dinosaurs were found on nests, and those nests contain large clutches of eggs, as many as 30 each. Varricchio and his colleagues investigated whether they could discern the nesting behavior from the relationship of the clutch size and the animal's body size. Measurements in 433 living birds and crocodiles revealed that, for a given body size, species in which males took care of the nest tended to have the largest clutches. The next-largest clutches were cared for by mothers. Mom-dad partnerships had the smallest clutches. Extrapolated to dinosaurs, the data revealed a pattern of paternal care in the ancient beasts.
Another line of evidence in the paper comes from Gregory Erickson, a biologist at Florida State University in Tallahassee. His studies of dinosaur bone tissue showed that none of the seven specimens associated with nests showed signs of changes associated with egg laying, such as medullary tissue (ScienceNOW, 2 June 2005). That's not sure-fire proof the nest-caretakers were male, he notes, but it's consistent with the hypothesis. The findings are reported in tomorrow's issue of Science.
Richard Prum, an ornithologist at Yale University, says he never expected paternal care in dinosaurs. But with their dinosaur ancestors showing more and more traits once thought to be exclusive to birds, such as feathers, he says the finding makes sense. It also points to a question on the reproductive frontier: Did dinosaurs practice polygamy?
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Anything Into Ethanol
Forget about corn—future biofuels will be made of wood chips and trash.
Robb Mandelbaum
Biofuels could be a crucial weapon against both rising temperatures and dwindling global oil supplies. They are made from organic material such as plants, so they essentially recycle existing carbon in the atmosphere instead of releasing new carbon from the depths of the earth; they are also, in principle, endlessly renewable. But the best-known biofuel, ethanol, is looking decidedly unpromising right now. Today most ethanol in the United States is made from corn, using an energy-intensive process that may not actually save a lot of fossil fuel, and in any case America cannot produce enough ethanol from corn to really matter.
Scientists have long tried to devise an efficient way to make ethanol from a wider range of raw materials, especially waste products rather than food. The U.S. government has calculated that the country could generate 1.4 billion tons of biomass a year. This could make 100 billion gallons of fuel or more, enough to meet much of America’s demand for motor gasoline. One approach to tapping into all that biomass focuses on cellulose, the material that gives plant cells their strong walls. The cellulose is converted into sugar and then from sugar into ethanol. But despite decades of research, the technology is still far from commercially viable.
Now several companies, including Coskata and Range Fuels, say they have cracked the problem. They are pursuing a different strategy, one that turns any carbon-rich matter into a gas, which is then converted to liquid fuel. This approach can use any organic material, so the potential sources for this fuel are virtually unlimited. Soon, the companies claim, they will be able to refine vast quantities of noncorn ethanol. Coskata even predicts they will do so for as little as $1 a gallon.
Biofuels could be a crucial weapon against both rising temperatures and dwindling global oil supplies. They are made from organic material such as plants, so they essentially recycle existing carbon in the atmosphere instead of releasing new carbon from the depths of the earth; they are also, in principle, endlessly renewable. But the best-known biofuel, ethanol, is looking decidedly unpromising right now. Today most ethanol in the United States is made from corn, using an energy-intensive process that may not actually save a lot of fossil fuel, and in any case America cannot produce enough ethanol from corn to really matter.
Scientists have long tried to devise an efficient way to make ethanol from a wider range of raw materials, especially waste products rather than food. The U.S. government has calculated that the country could generate 1.4 billion tons of biomass a year. This could make 100 billion gallons of fuel or more, enough to meet much of America’s demand for motor gasoline. One approach to tapping into all that biomass focuses on cellulose, the material that gives plant cells their strong walls. The cellulose is converted into sugar and then from sugar into ethanol. But despite decades of research, the technology is still far from commercially viable.
Now several companies, including Coskata and Range Fuels, say they have cracked the problem. They are pursuing a different strategy, one that turns any carbon-rich matter into a gas, which is then converted to liquid fuel. This approach can use any organic material, so the potential sources for this fuel are virtually unlimited. Soon, the companies claim, they will be able to refine vast quantities of noncorn ethanol. Coskata even predicts they will do so for as little as $1 a gallon.
Range Fuels initially hoped to feed its refinery with leaves and small limbs that the timber industry cannot process. The Georgia Forestry Commission reports that each year loggers leave behind some 8 million tons of waste wood, including too-small living trees, within a 75-mile radius of the new refinery—enough for four of Range Fuels’ plants. But getting that material to the refinery has proved difficult. “The timber industries are really not set up to do that,” says Range Fuels’ Mandich.
Nobody has yet figured out how to compact forest leftovers for transport. “Have you ever tried to move your leaves in the fall?” asks Richard Hess, a scientist studying the problem at Idaho National Laboratory. “You fill up this garbage sack and it doesn’t weigh anything. That’s the problem. It takes a lot of energy to move air.” Still, Hess expects optimized handling systems will be ready by 2012, meeting the government’s goal and in time for a wave of new refineries. “We’re rich in opportunities to make fairly epic gains,” he says. Until then Range Fuels will source its wood chips from whole trees—not a waste product at all, but a commodity used to make paper pulp.
It might not be long before the ethanol companies are paying to get more biomass waste headed into their plants. According to Richard Bain, a researcher at NREL, the estimated cost of producing a gallon of ethanol stands at $2.10 today. By 2012 this should fall to $1.33—at least for those companies using steam to turn biomass into syngas (several firms, he says, have developed this technology). At the same time, the steep price of gasoline—and corn—means that next-generation ethanol can be profitable even if its price doesn’t reach what Khosla Ventures’ Kaul calls the “holy grail” of $1 a gallon. Freed from the bad rap of corn ethanol, biofuel-powered cars could then drive us toward a better future.
New life found in ancient tombs
The Catacombs of Saint Callistus are part of a massive graveyard that covers 15 hectares, equivalent to more than 20 football pitches. The underground tombs were built at the end of the 2nd Century AD and were named after Pope Saint Callistus I. More than 30 popes and martyrs are buried in the catacombs.
"Bacteria can grow on the walls of these underground tombs and often cause damage," said Professor Dr Clara Urzì from the University of Messina in Italy. "We found two new species of bacteria on decayed surfaces in the catacombs and we think the bacteria, which belong to the Kribbella group, may have been involved in the destruction."
By studying bacteria that ruin monuments, the researchers hope to develop methods of protecting cultural heritage sites such as the catacombs in Rome. The two new bacterial species discovered in the tombs also have the potential to produce molecules that have useful properties, like enzymes and antibiotics.
"The special conditions in the catacombs have allowed unique species to evolve," said Professor Dr Urzì. "In fact, the two different Kribbella species we discovered were taken from two sites very close to each other; this shows that even small changes in the micro-environment can lead bacteria to evolve separately."
Kribbella species are found in many different locations all over the world, from a racecourse in South Africa to a medieval mine in Germany. The genus was only discovered in 1999 but since then several species have been found. The two species discovered in the Roman catacombs have been named Kribbella catacumbae and Kribbella sancticallisti.
"The worldwide existence of the genus Kribbella raises questions about the path of evolution," said Professor Dr Urzì. "If the bacteria are very old, does the wide geographical distribution prove the genus is stable? Or have similar bacteria evolved in parallel to one another in different places? The questions are made even more interesting by the discovery of these two different bacteria in the Roman tombs."
100 greatest discoveries- Biology
Biology1. Microorganisms (1674)
Microscope lens grinder Anton Van Leeuwenhoek accidentally discovers microorganisms in a drop of water. Using his own microscopes, he observes sperm, bacteria and red blood cells. His observations lay the foundation for the sciences of bacteriology and microbiology.
2. The Cell Nucleus (1831)
While studying an orchid, botanist Robert Brown identifies a structure within the cells that he terms the "nucleus."
3. Archaea (1977)
Carl Woese discovers bacteria are not the only simple-celled prokaryotes (unicellular organisms without a nucleus) on Earth. Many of the organisms classified in the new kingdom of Archaea are extremophiles. Some live at very high or low temperatures, others in highly saline, acidic or alkaline water. Some have been found in environments like marshland, sewage and soil. Archaea are usually harmless to other organisms and none are known to cause disease.
4. Cell Division (1879)
Walther Flemming carefully observes that animal cells divide in stages and calls the process mitosis. Eduard Strasburger independently identifies a similar process of cellular division in plant cells.
5. Sex Cells (1884)
August Weismann identifies that sex cells must have divided differently to end up with only half of a chromosomal set. This very special division of sex cells is called meiosis. Weismann's experiments with reproduction in jellyfish lead him to the conclusion that variations in offspring result from the union of a substance from the parents. He refers to this substance as "germ plasm."
6. Cell Differentiation (late 19th century)
Several scientists participate in the discovery of cell differentiation, eventually leading to the isolation of human embryonic stem cells. During differentiation, a cell turns into one of the many cell types that make up the body, such as a lung, skin or muscle cell. Certain genes are activated and others are inactivated, so the cell develops structures to perform a specific function. Cells that are not yet differentiated and have the potential to become any type of cell are called stem cells.
7. Mitochondria (late 19th century to the present)
Scientists discover mitochondria, the powerhouses of the cell. These small structures within animal cells are responsible for metabolism and convert food into chemicals that cells can use. Originally thought to be part of the cell, scientists now believe they are specialized bacteria with their own DNA.
8. The Krebs Cycle (1937)
Hans Krebs identifies the many steps the cell takes to convert sugars, fats and proteins into energy. Also known as the citric acid cycle, it is a series of chemical reactions using oxygen as part of cellular respiration. The cycle contributes to the breakdown of carbohydrates, fats and proteins into carbon dioxide and water.
9. Neurotransmission (late 19th to early 20th century)
Scientists discover neurotransmitters and how they tell the body what to do by passing signals from one nerve cell to another via chemical substances or electrical signals.
10. Hormones (1903)
William H. Bayliss and Ernest H. Starling give hormones their name and reveal their role as chemical messengers. The team specifically describes secretin, a substance released into the blood from the duodenum (between the stomach and small intestine) that stimulates secretion of pancreatic digestive juice into the intestine.
11. Photosynthesis (1770s)
Jan Ingenhousz discovers that plants react to sunlight differently than shade. The underpinnings of the understanding of photosynthesis are born. Photosynthesis is a process in which plants, algae and certain bacteria convert the energy of light into chemical energy. In plants, leaves take in carbon dioxide and roots absorb water. Sunlight runs a reaction that yields glucose (food for the plant) and oxygen (a waste product released into the environment). Nearly all living things on Earth are ultimately dependent on this process.
12. Ecosystem (1935)
Arthur George Tansley coins the term ecosystem and single-handedly bridges the biology in ecology with the physics, chemistry and other fields of science that describe the environment. An ecosystem is defined as a dynamic and complex whole that functions as an ecological unit.
13. Tropical Biodiversity (15th century to the present)
On sailing expeditions around the world, early European explorers notice that the tropics host a much greater variety of species. Answering why this is the case allows today's scientists to help protect life on Earth.
Source: Science Channel
Avian Influenza (Bird Flu) - Overview
Overview
Sabra L. Katz-Wise; Ralph Poore
Content provided by Healthwise
What is bird flu?
Bird flu is an infection caused by a type of avian influenza virus. Although there are many types of bird flu, the type that now concerns health workers is the H5N1 bird flu virus. This virus is found in wild birds. Most of the time, wild birds do not get sick from the virus. But wild birds can easily pass the virus to birds that are being raised for food—such as chickens, ducks, and turkeys—and cause them to get very sick.
Usually, bird flu virus is not passed from birds to people. But since 1997, some people have become sick with this serious, deadly type of bird flu. Most of these infections have been in Asian countries among people who have had close contact with farm-raised birds.
What causes bird flu?
Bird flu is caused by an infection with a virus. After a wild bird infects a farm-raised bird, the virus can easily and quickly spread among hundreds or thousands of birds. Sick birds must then be killed to stop the virus from spreading.
People who come into contact with sick chickens, ducks, or turkeys are more likely to get the virus. Bird flu virus can be passed through bird droppings and saliva. It can also live on surfaces such as cages, tractors, and other farm equipment.
Most people do not need to worry about getting sick with bird flu virus. You cannot get bird flu from eating cooked chicken, turkey, or duck because heat makes the bird flu virus inactive.
Why are people so worried about H5N1 bird flu?
In a few cases, experts think that bird flu was passed from a person to a person, not from a bird to a person. Because viruses can change quickly (mutate), experts worry that bird flu will one day be passed easily from person to person. This is a scary possibility because the H5N1 bird flu virus can make people more sick than other types of flu viruses. Even though only a few hundred people are known to have been sick with bird flu, more than half of them have died.
Experts also worry because the H5N1 bird flu virus is so different from other flu viruses that our bodies do not have any immunity . Not having immunity means that our bodies have a hard time fighting the virus. It also means that anyone, including those who are otherwise very healthy, can get seriously ill if he or she gets this type of bird flu.
What are the symptoms?
Symptoms of bird flu can be the same as common flu symptoms, such as:
- A fever.
- A cough.
- A sore throat.
- Muscle aches.
- An eye infection (conjunctivitis ).
More serious symptoms of bird flu include:
- Pneumonia , a serious lung infection.
- Acute respiratory distress syndrome , a life-threatening lung problem.
If you have traveled somewhere or live in an area where there is bird flu and you have a fever and a hard time breathing, contact your doctor right away.
How is it diagnosed and treated?
If your doctor thinks you may have bird flu, he or she will do a physical exam and ask you questions about your symptoms and past health. Your doctor will also ask you where you live, where you have traveled recently, and if you have been near any birds. Then your doctor may order blood tests, nasal swabs, or other tests, such as X-rays , to help find out what is making you sick.
Some questions your doctor might ask are:
- Have you been in close contact with live, sick, or dead poultry, or wild birds within 3 ft]?
- Have you eaten raw or poorly cooked poultry or poultry products?
- Have you had close contact (touching or speaking distance) with someone from an area affected with H5N1 bird flu virus who has a severe respiratory illness or someone who later died from an unknown cause?
- Are you a laboratory or poultry worker who might have been exposed to H5N1 bird flu virus?
Treatment for bird flu depends on what the virus is doing to your body. In some cases, antiviral medicines may help improve symptoms. But experts are concerned that bird flu may be resistant to certain antiviral medicines. Viruses become resistant when they change over time and then the medicines that killed them in the past no longer work well.
If you have bird flu, you will stay in a private hospital room (isolation room ) to reduce the chances of spreading the virus to others. When your doctors and nurses are caring for you, they will wear gloves and gowns. Some people who have bird flu may need a machine to help them breathe better (a ventilator ). Other people may need a machine to help the kidneys work better (kidney dialysis ). More than half of the time, bird flu leads to death.
So far, no cases of H5N1 bird flu in humans have been found in Canada or the United States. Most human cases have occurred in Asian countries. But experts believe the virus may eventually spread to all parts of the world.
What is being done to prevent the spread of bird flu? What can I do to prevent it?
The World Health Organization and the U.S. Centers for Disease Control and Prevention are preparing for the possibility that bird flu could spread to people all over the world (a pandemic). Experts are working on a shot (vaccine) to protect people from getting the H5N1 bird flu virus. They are also storing up large supplies of antiviral medicines. The United States government has also developed a flu plan. This is a plan to prepare for a pandemic and to make sure as few people as possible get the virus.
International health organizations now require that all infected birds be killed. Some countries have programs to clean up poultry farms and to check that all birds are healthy before they are sold. In 2004, the United States stopped buying poultry from most Asian countries.
Even though there is a lot of talk about bird flu, most people do not have to worry about getting it. As of spring 2006, no cases of bird flu in humans have been found in the United States. But you can take steps to lower your chances of getting infected.
- If you live in an area with bird flu or if you are traveling to a country where there is bird flu:
- Avoid poultry farms, poultry-processing factories or plants, and close contact with chickens, turkeys, or ducks.
- Stay away from open-air markets where live birds are sold.
- If you are traveling to a country where there is bird flu, you can also do the following:
- Ask your doctor about getting a regular flu shot. It is best to do this at least 2 weeks before you leave. This will not prevent bird flu, but it may help you avoid getting the regular flu.
- Keep your hands clean by washing them often with soap and warm water or using a hand gel that kills germs. If you use a hand gel, be sure to buy only gels made with alcohol. They do the best job of cleaning your hands.
- Do not eat raw eggs or raw poultry. But you can safely eat cooked eggs and cooked chicken, duck, and turkey because heat kills the bird flu virus.
