Interesting Facts about Dolphins

How do dolphins sleep?
Dolphins have to be conscious to breath. This means that they cannot go into a full deep sleep, because then they would suffocate. Dolphins have "solved" that by letting one half of their brain sleep at a time. This has been determined by doing EEG studies on dolphins. Dolphins sleep about 8 hours day in this fashion.

A dolphin's behavior when sleeping/resting depends on the circumstances and possibly on individual preferences. They can either:
1. swim slowly and surface every now and then for a breath
2. rest at the surface with their blowhole exposed
3. rest on the bottom (in shallow water) and rise to the surface every now and then to breath.
How smart are dolphins?
The short answer to this is that we do not know. There is no reliable method to measure intelligence in humans across cultures, so it is not surprising that comparing humans, dolphins, apes, dogs, etc. is impossible. There are some indications of their potential: they are fast learners and can generalize (which is also true of pigs). Also they can learn to understand complicated language-like commands (which is also true of the great apes).

How much do dolphins eat?
Bottlenose dolphins eat several kinds of fish (including mullet, mackerel, herring, cod) and squid. The compostion of the diet depends very much on what is available in the area they live in and also on the season. The amount of fish they eat depends on the fish species they are feeding on: mackerel and herring have a very high fat content and consequently have a high caloric value, whereas squid has a very low caloric value, so to get the same energy intake (calories) they will need to eat much more if they feed on squid than if they feed on mackerel or herring. On average an adult dolphin will eat 4-9% of its body weight in fish, so a 250 kg (550 lb) dolphin will eat 10-22.5 kg (22-50 lb) fish per day.

How long do dolphins live?
The maximum age for bottlenose dolphins is between 40 and 50 years. The average age a dolphin can get (the life expectancy) can be calculated from the ASR Annual Survival Rate (the percentage of animals alive at a certain point, that is still alive one year later). For the dolphin population in Sarasota Bay, the ASR has been measured to be about 0.961. This yields a life expectancy of about 25 years. For the population in the Indian/Banana River area, the ASR is between 0.908 and 0.931. This yields a life expectance between 10.3 and 14 years. So the actual life expectancy differs per region.

How deep can a dolphin dive?
The deepest dive ever recorded for a bottlenose dolphin was a 300 meters (990 feet). This was accomplished by Tuffy, a dolphin trained by the US Navy. Most likely dolphins do not dive very deep, though. Many bottlenose dolphins live in fairly shallow water. In the Sarasota Bay area, the dolphins spend a considarable time in waters that are less than 2 meters (7 feet) deep.

Other whale and dolphin species are able to dive to much greater depths even. The pilot whale (Globicephala melaena) can dive to at least 600 meters (2000 feet) and a sperm whale (Physeter macrocephalus) has been found entangled in a cable at more that 900 meters (500 fathoms) depth.

Recent studies on the behavior of belugas (Delphinapterus leucas) has revealed that they regularly dive to depths of 800 meters. The deepest dive recorded of a beluga was to 1250 meters.

Do dolphins drink salt water?
Most dolphins live in the ocean and the ocean water is too salty for them to drink! If they would drink sea water, they would actually use more water trying to get rid of the salt than they drank in the first place. Most of their water comes from their food (fish and squid). Also, when they metabolize (burn) their fat, water is released in the process. Their kidneys are also adapted to retaining as much water as possible. Although they live in water, they live as desert animals with no direct source of drinkable water.

Mass strandings: Why?
If a single whale or dolphin strands, it usually is a very sick (and exhausted) animal. Such an animal often has some infections (pneumonia is almost always one of them) and a lot of parasites (worms in the nasal passages are very common). Sometimes these animals can be rehabilitated, but often they are so sick they won't make it.

Some species of whales and dolphins occassionally strand in groups. A stranding of 2 or more animals is usually called a mass stranding. There are a number of theories that try to explain the occurrence of mass strandings. No theory can adequately explain all of them. In some cases it will be a combination of causes. The most common explanations are:

deep water animals (the species that most often are the victim of mass strandings) can not "see" a sloping sandy beach properly with its sonar. They detect the beach only when they are almost stranded already and they will panic and run aground.
whales and dolphins may be navigating by the earth's magnetic field. When the magnetic field is disturbed (this occurs at certain locations) the animals get lost and may run into a beach.
in some highly social species, the group leader may be sick and wash ashore. The other members try to stay close and may strand with the group leader.
when under severe stress or in panic, the animals may fall back to the behavior of their early ancestors and run to shore to find safety.


Interesting Facts About Balsa Wood

Model airplanes are no different than any other type of flying machine, large or small - THE LIGHTER IT IS BUILT, THE BETTER IT WILL FLY! With that in mind, it is easy to understand why balsa wood has been the standard material for model airplane construction since it first became readily available in the U.S. in the late 1920s. Its outstanding strength-to-weight ratio enables hobbyists to construct durable models that fly in a totally realistic manner. Balsa also absorbs shock and vibration well and can be easily cut, shaped, and glued with simple hand tools.

Balsa trees grow naturally in the humid rain forests of Central and South America. Its natural range extends south from Guatemala, through Central America, to the north and west coast of South America as far as Bolivia. However, the small country of Ecquador on the western coast of South America, is the primary source of model aircraft grade blasa in the world. Blasa needs a warm climate with plenty of rainfall and good drainage. For that reason, the best stands of balsa usually appear on the high ground between tropical rivers. Ecquador has the ideal geography and climate for growing balsa trees. The scientific name for balsa wood is ochroma lagopus. The word balsa itself is Spanish meaning raft, in reference to its excellent floatation qualities. In Ecquador it is known as Boya, meaning buoy.

There is no such thing as entire forests of balsa trees. They grow singly or in very small, widely scattered groups in the jungle. For hundreds of years, balsa was actually considered a weed tree. They reproduce by growing hundreds of long seed pods, which eventually open up and, with the help of the wind, scatter thousands of new seeds over a large area of the jungle. Each seed is airborne on its own small wisp of down, similar to the way dandelion seeds spread. The seeds eventually fall to the ground and are covered by the litter of the jungle. There they lay and accumulate until one day there is an opening in the jungle canopy large enough for the sun's rays to strike the jungle floor and start the seeds growing. Wherever there is an opening, made either by a farmer or by another tree dying, balsa will spring up as thick as grass. A farmer is often hard put to keep his food plot clear of balsa. As the new balsa trees grow, the strongest will become predominate and the weaker trees will die. By the time they are mature, there may be only one or two basa trees to an acre of jungle.

Balsa trees grow very rapidly (like all pesky weeds). Six months after germination, the tree is about 1-1/2 inches in diameter and 10 - 12 feet tall. In 6 to 10 years the tree is ready for cutting, having reached a height of 60 to 90 feet tall and a diameter of 12 to 45 inches. If left to continue growing, the new wood being grown on the outside layers becomes very hard and the tree begins to rot in the center. Unharvested, a balsa tree may grow to a diameter of 6 feet or more, but very little usable lumber can be obtained from a tree of this size. The basla leaf is similar in shape to a grape leaf, only a lot bigger. When the tree is young, these leaves measure a much as four feet across. They become progressivly smaller as the tree grows older, until they are about 8 - 10 inches across. Balsa is one of the few trees in the jungle which has a simple leaf shape. This fact alone makes the balsa tree stand out in the jungle.

Nature evidently designed the balsa tree to be a "nurse tree" which would protect the slower-growing species of trees from the scorching jungle sun during their critical early years. For instance, in an area of the jungle that has been ravaged by a tropical storm or other natural disaster, the balsa trees will quickly sprout and begin to shoot up to impressive heights in a very short time. Their fast growth, and the extra large leaves they have in their early years, provide shade to the young seedlings of the slower-growing forest giants. By the time the seedlings are established enough to take care of themselves, the balsa tree is beginning to die. Undoubtably, the balsa tree's rapid growth, fast spreading crown of first very large and gradually smaller leaves, and it's relatively short life span were intended to make it the "perfect nurse" in the jungle ecosystem.

While nature intended the balsa tree to be a short lived nursemaid, mankind eventually discovered that it was an extremely useful resource. The real start of the basa business was during World War I, when the allies were in need of a plentiful substitute for cork. The only drawback to using balsa was, and still is, the back breaking work that is necessary to get it out of the jungle. Beacause of the way the individual balsa trees are scattered throughtout the jungles, it has never been possible to use mass production logging procedures and equipment. The best way to log balsa trees is to go back to the methods of Paul Bunyan -- chop them down with an axe, haul them to the nearest river by ox team, tie them together into rafts, and then float the rafts of balsa logs down the river to the saw mill.
The logging team usually consists of two native Ecquadorians, each armed with a broad Spanish axe, a machete, and a long pole sharpened like a chisel on one end for removing the bark from the downed trees. Because of the hilly terrain, an ox team may only be able to drag two logs to the river per day. At the saw mill the raw balsa is first rough cut into large boards, the carefully kiln dried, and finally packed into bales for shipment to the U.S. via ocean freighter. Final cutting and finishing of our model aircraft balsa is done right here at the SIG factory. As a result of the balsa tree's fast growth cycle, both the quality and lightness of the lumber obtained from a balsa tree can vary enormously depending upon the tree's age at the time of cutting.

The secret to balsa wood's lightness can only be seen with a microscope. The cells are big and very thin walled, so that the ratio of solid matter to open space is as small as possible. Most woods have gobs of heavy, plastic-like cement, called lignin, holding the cells together. In balsa, lignin is at a minimum. Only about 40% of the volume of a piece of balsa is solid substance. To give a balsa tree the strength it needs to stand in the jungle, nature pumps each balsa cell full of water until they become rigid - like a car tire full of air. Green balsa wood typically contains five times as much water by weight as it has actual wood substance, compared to most hardwoods which contain very little water in relation to wood substance. Green balsa wood must therefore be carefully kiln dried to remove most of the water before it can be sold. Kiln drying is a tedious two week process that carefully removes the excess water until the moisture content is only 6%. Kiln drying also kills any bacteria, fungi, and insects that may have been in the raw balsa wood.

Finished balsa wood, like you find in model airplane kits, varies widely in weight. Balsa is occasionally found weighing as little as 4 lbs. per cu. ft. On the other hand, you can also find balsa which will weigh 24 lbs or more per cu. ft. However, the general run of commercial balsa for model airplanes will weigh between 6 and 18 pounds per cu. ft. Eight to twelve pound balsa is considered medium or average weight, and is the most plentiful. Six pound or less is considered "contest grade", which is very rare and sometimes even impossible to obtain.

No! Most people are surprised to hear that botanically, balsa wood is only about the third or fourth lightest wood in the world. However, all the woods which are lighter than balsa are terribly weak and unsuitable for any practical use. The very lightest varieties don't really resemble wood at all, as we commonly think of it, but are more like a tree-like vegetable that grows in rings, similar in texture to an onion. It is not until balsa is reached that there is any sign of real strength combined with lightness. In fact, balsa wood is often considered the strongest wood for its weight in the world. Pound for pound it is stronger in some respects than pine, hickory, or even oak.

Most hobby shops have a large rack of balsa sheets, sticks, and blocks that you can choose from if you are going to build a model airplane from scratch. Undoubtably, because of the nature of balsa, the actual weight of each piece of wood of the same size can vary slightly. When you select the pieces you want to buy you should keep their final use in mind. Logically one should select the lightest grades for the lightly stressed model parts (nose blocks, wingtip blocks, fill-ins, etc.) and the heavier grades for important load bearing parts of the structure (spars, fuselage stringers, etc.). To a large extent, this selection is already partly done for you. Here at SIG, we purosely cut up our lightest raw balsa into blocks, and our hardest raw balsa into sticks. Sheets are cut in the entire wide range of density.

Balsa is a very "friendly" wood to work with -- so light, so soft, so easily worked into so many things. You don't need heavy-duty power saws and sanders like you would if working with a hardwood. In fact, even with an extensive power shop at their disposal, the professional model builders here at the SIG factory find that they still rely primarily on 4 or 5 simple hand tools for the majority of their work. If you are just starting out in the model airplane hobby, here are the tools that they recommend you get:
X-ACTO No. 1 knife with No. 11 blade for general cutting; X-ACTO No. 2 knife with No. 26 blade for carving; Razor saw for cutting thick sizes of wood; Razor plane for shaping; A knife or razor blade will work well for cutting balsa sheets and sticks up to 3/16". Always keep replacement blades on hand - blades do wear our and a dull blade can make it impossible to do a good job.

In addition to the cutting tools, you will need an assortment of different size sanding blocks. These are indispenable tools for model construction. You can buy ready-made sanding blocks or make your own. The most often used general-purpose sanding block in our model shop is made simply by wrapping a full 9" x 11" sheet of sandpaper around a 3/4" x 3" x 11" hardwood or plywood block. Use three screws along one edge to hold the overlapped ends of the sandpaper in place. Use 80 grit garnet sandpaper on the block during general construction. Another handy sanding block to have can be made by gluing 80 grit garnet sandpaper onto a 24" or 36" long piece of aluminum channel stock. Most hardware stores carry a rack of aluminum in various sizes and shapes. This long sanding block is very helpful for shaping leading and trailing edges, and other large pieces, accurately. Last but not least, glue sandpaper onto different sizes of scrap plywood sticks and round hardwood dowels. These are handy for working in tight places and for careful shaping where a big sanding block is too hard to control.

In selecting balsa sheets for use in your model, it is important to consider the way the grain runs through the sheet as well as the weight of the sheet. The grain direction actually controls the rigidity or flexibility of a balsa sheet more than the density does. For example, if the sheet is cut from the log so that the tree's annular rings run across the thickness of the sheet (A-grain, tangent cut), then the sheet will be fairly flexible edge to edge. In fact, after soaking in water some tangent cut sheets can be completely rolled into a tube shape without splitting. If on the other hand the sheet is cut with the annular rings running through the thickness of the sheet (C-grain, quarter grain), the sheet will be very rigid edge to edge and cannot be bent without splitting. When the grain direction is less clearly defined (B-grain, random cut), the sheet will have most intermediate properties between A and C grain. Naturally, B-grain is the most common and is suitable for most jobs. The point to bear in mind is that whenever you come across pure A-grain or C-grain sheets, learn where to use them to take best advantage of their special characteristics.

A-GRAIN sheet balsa has long fibers that show up as long grain lines. It is very flexible across the sheet and bends around curves easily. Also warps easily. Sometimes called "tangent cut." DO use for sheet covering rounded fuselages and wing leading edges, planking fuselages, forming tubes, strong flexible spars, HL glider fuselages. DON'T use for sheet balsa wings or tail surfaces, flat fuselage sides, ribs, or formers.

B-GRAIN sheet balsa has some of the qualities of both type A and type C. Grain lines are shorter than type A, and it feels stiffer across the sheet. It is a general puropse sheet and can be used for many jobs. Sometimes called "random cut." DO use for flat fuselage sides, trailing edges, wing ribs, formers, planking gradual curves, wing leading edge sheeting. DON'T use where type A or type C will do a significantly better job.

C-GRAIN sheet balsa has a beautiful mottled appearance. It is very stiff across the sheet and spits easily. But when used properly, it helps to build the lightest, strongest models. Most warp resistant type. Sometimes called "quarter grain." DO use for sheet balsa wings and tails, flat fuselage sides, wing ribs, formers, trailing edges. Best type for HL glider wings and tails. DON'T use for curved planking, rounded fuselages, round tubes, HL glider fuselages, or wing spars.


Interesting Facts About Transplantation

Transplantation is now a highly successful procedure, which is considered routine surgical practice for people with serious kidney, liver, heart or lung disease. Over the past 50 years, surgeons have made great strides in their ability to implant organs in people who are seriously ill. At least 21 different organs such as hearts, livers and kidneys and tissues such as corneas and bone marrow can now be successfully transplanted into patients who can then expect to survive for years or even decades. It is the treatment of choice for many diseases, but all too often a suitable organ is not available to meet the ever-increasing demand for transplantation.

For medical transplantation to be successful, physicians must elude the combative efforts of the bodys complex immune system, which fights to protect the body from infections of all sorts. Central to the functioning of the immune system is its ability to distinguish between invading or foreign matter, which should be attacked, and matter that is a normal part of the body, which should not be attacked. This recognition system causes the immune system to attack transplanted tissues because it has no way to distinguish between harmful and beneficial foreign matter.

Because of this rejection, the recipient must take drugs to suppress the immune response. The first drugs that were used were azathioprine and prednisone. But these drugs suppress the entire immune system, leaving the recipient vulnerable to infections and certain cancers. They also have toxic side effects. A major breakthrough in immune suppression was the development of cyclosporine, a natural product derived from a fungus found in the soil. Cyclosporine suppresses the part of the immune system involved in organ rejection with less severe impact on other parts of the immune system.

The diseases that most often create a need for kidney transplantation are glomerulonephritis (inflammation of the kidneys), diabetes, hypertension and cystic kidney failure. People with these diseases who have failing kidneys have to undergo regular treatment with an artificial kidney (haemodialysis). Kidney dialysis is the procedure in which blood is circulated through a machine that removes wastes and excess fluids from the bloodstream. The patient must be hooked up to the dialysis machine two to three times each week for as long as 12 hours at a time. Some patients use dialysis for a short time, while their kidneys recover from injury or disease. Others must use dialysis for their entire lives or until they undergo a kidney transplant. However, dialysis can only replace about 5% of the function of two healthy kidneys, and for many people their quality of life on dialysis is very poor. Additionally, life expectancy is lower for people on dialysis than for the normal population.

Kidney transplantation is the best treatment possible for kidney failure. Kidney transplants are also the most common of all transplant operations and have excellent success rates. It can improve quality of life dramatically and increase life expectancy.

One year after transplantation of a kidney from a brain-dead donor around 90% of transplants are still functioning well. After five years over 60% are still healthy and overcoming any need for dialysis. Some kidney transplant patients have survived more than 25 years.

Because people have two kidneys but need only one, a living relative often serves as a donor, retaining one kidney for his or her own use. About one-third of transplanted kidneys come from living relatives and about two-thirds are from someone who recently died.

For people with severe liver disease, transplantation can sometimes be the only effective treatment available. The most common diseases that cause a need for liver transplantation are cirrhosis, some types of chronic hepatitis, acute liver failure, or inflammation of the bile ducts that lead into the liver (primary sclerosing cholangitis).

The liver is the only internal organ with the capacity to regenerate. This capacity provides the surgeon additional flexibility in treating liver damage. For instance, if the damage is not very severe, a temporary transplant can take over the livers function while the patients own liver recovers. It is also possible to remove part of a liver from a living donor and transplant it. After the surgery both the donors liver and the transplanted portion will grow to full size.

Fortunately, waiting lists for liver transplants are shorter than for kidneys. At one year, around 80% of liver transplants are working well. This falls to 60 65% after five years.

Heart transplants are perhaps the most dramatic of all organ transplants because without a functioning heart, a patient cannot survive more than a few minutes. On December 3, 1967, Christiaan Barnard performed the first human heart transplant, transferring the heart of a 25-year-old woman into the body of Louis Washkansky, a 55-year-old grocer, Washkansky died 18 days later. The second transplant, on January 2, 1968, was for Philip Blaiberg, who lived for 563 days after the operation. However, heart transplant surgery later became standard after the development of powerful drugs that prevented the bodys immune system from rejecting the transplant.

The most common cause of heart failure is coronary heart failure. The final stage in almost any type of heart disease is heart failure, also known as congestive heart failure, in which the heart muscle weakens and is unable to pump enough blood to the body. In response to this shortfall, the kidneys conserve water in an attempt to increase blood volume, and the heart is stimulated to pump harder. Eventually excess fluid seeps through the walls of tiny blood vessels and into the tissues. Fluid may collect in the lungs, making breathing difficult, especially when a patient is lying down at night. Many patients with heart failure must sleep propped up on pillows to be able to breathe. Fluid may also build up in the ankles, legs or abdomen. In the later stages of heart failure, any type of physical activity becomes next to impossible. Heart failure can sometimes be reversed and can often be effectively treated for long periods with a combination of drugs. A last resort in the treatment of heart failure is heart transplantation, in which a diseased heart is replaced with a healthy heart from a person who has died of other causes.

Heart transplantation is an effective option: Most patients are able to resume a normal life about six months after surgery and 85% of heart transplants are still working well after a year, and almost 70% after five years. However, because there is only a limited supply of donor hearts, many people who could potentially benefit from heart transplantation are not placed on the waiting list.

Increasingly, cystic fibrosis patients with severe, irreparable lung damage turn to lung transplantation surgery. Although complications with transplantation surgery may pose problems for some patients, lung or combination heart and lung transplants provide nearly 80% of cystic fibrosis patients with severe lung damage an entirely new lease on life.

In nearly 20% of all cases, the first symptom is intestinal blockage in newborns. In other babies, the first evidence is bulky stool, poor weight gain, flabby muscle tone, or slow growth, all products of low levels of digestive enzymes in the intestines. About half of all children with cystic fibrosis first see the doctor for coughing, wheezing, or respiratory tract infections. Teenagers with cystic fibrosis may grow slowly and enter puberty later than their peers. Cystic fibrosis often causes impaired reproductive function. Cystic fibrosis patients of all ages are prone to dehydration because they lose so much salt in their sweat. Infections, particularly in the lungs, plague people with cystic fibrosis throughout their lives. These chronic infections destroy lung tissue, a complication that ultimately takes the lives of most people with cystic fibrosis.

Eye banks concentrate on retrieving tissues used in eye surgery that restores or improves sight. Most eye banks focus on retrieving corneas. The cornea is the clear front window of the eye, about the size and shape of a coin. It transmits light to the interior of the eye allowing us to see clearly. Corneal injury, disease or hereditary conditions can cause clouding, distortion and scarring that may result in blindness. But corneal blindness is one of the few forms of blindness that can be cured. In a delicate procedure, the surgeon removes the damaged cornea and replaces it with a cornea donated by a recently deceased person. Cornea transplants are very successful, with a success rate of more than 90% if the cornea is placed on the eye in such a manner that blood vessels do not come into contact with it. Without blood vessels, the body cannot send immune cells to attack the cornea.

A burn is an injury to the skin caused when heat, chemicals, electricity, or radiation destroy tissue. Extensive burns, involving 30% or more of the bodys surface, can be life threatening because they disrupt the skins ability to fight infection, prevent fluid loss, and regulate body temperature. Deep burns are often treated with skin grafts. In this procedure, healthy skin removed from another area on the body is transferred to the burned area to cover the wound. If the burned area is not too large, the grafted skin will grow in its new location and eventually fuse with the healthy skin at the edges of the burn. But if burns cover a large portion of a patients body and not enough healthy skin remains to use for a graft, patients may receive grafts from dead bodies. Although the patients immune system eventually rejects and destroys this foreign tissue, these temporary skin grafts help prevent fluid loss and infection while the patients own skin heals.

Skin was the first tissue transplanted, and researchers used skin transplants in the late 1950s and early 1960s to decipher the immune system response to transplants.

Bone marrow is the living tissue found in the centre of many large bones of the body. Special cells on the bone marrow, called stem cells, are the source of both red blood cells, the primary component of blood, and white blood cells, the workhorses of the immune system. Certain blood diseases, including leukaemia and sickle cell anaemia, are the result of the stem cells in the bone marrow producing faulty blood cells. In some cases, these diseases can be treated by destroying all of the patients bone marrow and replacing it with new donor bone marrow that does not produce the faulty blood cells. Bone marrow transplants are also used in fighting breast cancers and other cancers because intensive radiation or chemotherapy used to cure the cancer also kills the patients bone marrow, which must then be replaced with a transplant.

Stem cell transplants require a closer matching of donor and recipient than is the case with other types of transplants. If the match is not good enough, the recipients body may reject the bone marrow or the white blood cells generated by the donor marrow can attack the recipients body, a phenomenon known as graft-versus-host disease. Formerly, stem cells could only be transplanted from the bone marrow of the donor, and the procedure was known as bone marrow transplantation. Recent advances now make it possible to recover stem cells from circulating blood, making the transplant procedure much simpler and less risky for the donor. A live donor is able to simply donate blood, from which the necessary cells and components are removed.

Bone is used for facial reconstruction of motor vehicle accident victims. Bone is also used in replacing cancerous growths in arms or legs of patients. In the past we used to have to amputate the limb.

Heart valves can also be replaced through transplantation. Pancreases can also be transplanted, although they are not done in South Africa. In America they have also started with small intestine transplants. Reliable survival data for intestine transplant patients are not yet available because the procedure is still experimental. Techniques are improving all the time and it may soon be practical to transplant other parts of the body.

One way to get around the shortage of donors is to use wholly or partially artificial organs made of plastic, metal, and other synthetic materials. A kidney dialysis machine, for example, is an artificial organ, even if it is too large to implant in the body. The first permanent artificial heart was transplanted in 1982, but the patient survived only for 112 days. Artificial hearts are not widely used today because of the risk of infection and bleeding and concerns about their reliability. In addition, the synthetic materials used to fashion artificial hearts can cause blood clots to form in the heart. These blood clots may travel to a vessel in the neck or head, resulting in a stroke. Instead, emphasis has shifted to the use of left-ventricular assist devices (LVADs), which are implanted beside a patients heart to help it pump blood. LVADs keep patients alive until a donor heart is available. Many artificial devices work to restore the operation of malfunctioning organs without replacing the whole organ. Examples include artificial heart valves and pacemakers to help the heart function properly, and cochlear implants to restore hearing.

The shortage of donors has led some surgeons to consider using animals as donors. Chimpanzee kidneys were successfully transplanted in 1963, with one recipient living for nine months after the surgery. Although the kidneys were not rejected, they proved too small to keep the recipient alive. Efforts to transplant chimpanzee and baboon hearts into humans in the 1960s and 1970s also failed because the hearts were too small. The first successful baboon organ transplant occurred in 1984, when a baboon's heart was transplanted into a two-week-old premature baby whose heart was congenitally malformed. The baby survived for 20 days before her body rejected the organ. Because of problems with the small size of chimpanzee and baboon organs, doctors are now turning to other species as potential organ donors.

One animal receiving a lot of attention from the medical community is the pig. Pigs have organs that are the right size for human use, they have large litters, and they mature quickly so there is a ready supply of donating animals. Human bodies do not reject some pig tissues, such as heart valves. Surgeons in the United States transplant about 60,000 pig heart valves into humans annually. However, other transplanted pig organs undergo a phenomenon called hyperacute rejection. The recipient's immune system recognizes that the blood vessels in the transplanted organ are foreign and shuts off blood flow to the new organ within hours or even minutes, causing the transplanted organ to blacken and die. Recently, scientists have used genetic engineering techniques to breed pigs whose blood vessels contain the marker antigens found in human blood vessels. Livers from these pigs have been successfully connected to the bloodstream of several patients to clear toxic wastes while the patients' own livers recovered. Fetal pig brain cells have also been used to treat Parkinson disease, and research is underway on using other organs from these pigs.

One of the big drawbacks of xenotransplants is the fear that unknown, possibly deadly viruses could be transferred from animals to humans. Once the animal viruses get into humans, they might spread to other humans. In 1997, scientists showed that pig viruses could infect humans with unpredictable results. The unresolved questions surrounding xenotransplantation mean that future research must be done cautiously.


Interesting Facts about Supreme Court of Canada

  • The Supreme Court of Canada was created by an Act of Parliament in 1875 as a general court of appeal.
  • The Court sat for the first time on January 17, 1876, but did not have any cases to hear. It heard its first case in April of that year.
  • The Court was originally composed of a Chief Justice and five puisne or associate judges. Today, the court is composed of a Chief Justice and eight puisne or associate judges.
  • Puisne judge: The word “puisne” is an old French word meaning younger. This term, used by the Supreme Court, distinguishes the Chief Justice from the other eight judges.
  • For years, Supreme Court decisions could be appealed to the Judicial Committee of the Privy Council in England. The right of appeal was abolished for criminal cases in 1933, and in all other cases in 1949.
  • The original Supreme Court of Canada was housed in a building located at the corner of Wellington and Bank Streets in Ottawa. The building had been the stables of Parliament before being converted into the Supreme Court building.
  • There are two flagstaffs at the front of the Supreme Court building. The Canadian flag to the west is hoisted daily, while the flag to the east only flies when the Court is sitting.
  • The current Supreme Court building was designed by Montreal architect Ernest Cormier, who also designed the University of Montreal, the Government Printing Bureau in Gatineau and the Quebec Court of Appeal in Montreal.
  • The cornerstone of the Court building is dated May 19, 1939, and was supposed to be laid by King George VI. Queen Elizabeth laid the cornerstone in the presence of the King, her husband, on May 20, 1939. (The arrival of their ship was delayed by a day due to bad weather on the Atlantic Ocean.)
  • The Supreme Court of Canada receives between 550 and 650 applications for leave to appeal every year and hears around 80 appeals.

Interesting Facts about Reptile

The first reptiles evolved in the Upper Carboniferous period, at least 300 million years ago. The Class Reptilia consists of three orders:

# Order Crocodilia, consisting of roughly 30 species and subspecies of crocodile, alligator and caiman

# Order Chelonia (tortoises and turtles), at least 244 species

# Order Squamata, includes lizards (over 3,750 species), snakes (about 3,000 species) and the lesser known Amphisbaenians or "worm lizard."

# There are about 160 species of Amphisbaenians, and they are found in Africa, Europe, Asia, North and South America. They are burrowing animals, up to 2 feet long, whose ring like scales gives them an earthworm like appearance.

# The fourth Order, Rhynchocephalia, flourished in pre-historic times but is now almost extinct. The number of species making up the single living genus, represented by the Tuatara, is still being argued.

# The Tuatara is extremely rare, found on just a few islands near New Zealand. Superficially lizard like, the Tuatara has unique eye and jaw anatomy, which among other factors separate it taxonomically (that is, the factors which determine its place in our classification of order, family, genus and species). Unusually for reptiles, Tuataras are adapted to life at temperatures as low as 6 degrees Celsius (43 degrees Fahrenheit).

Other interesting facts:

# Reptiles, like birds, have voluntary control over the muscles in their eyes, which determine their pupil size. This means that they are able to constrict or dilate their pupils at will, not just in response to light.

# The brain of a reptile is not more than 1 percent of his body mass. This means that the brain of a 70-pound python is no larger than a lima bean. Unlike amphibians, however, the reptilian brain has two hemispheres. Since man appears to use very little of his brain mass, the reptilian brain appears to be highly and efficiently adapted. The nervous systems of reptiles are sufficiently complex and similar to those of mammals that we can conclude that their senses and pain perception are highly refined. We are only beginning to understand just how highly specialized these animals are.

# Reptiles were the first vertebrates to evolve with 12 cranial nerves. "Lower" vertebrates have 10 pairs of these important nerves, which govern activities of the senses, such as sight, hearing and taste.

# The jaw structure of a reptile does not permit chewing; they can only tear their food.

# Some reptile species are known to store sperm and produce young 3 and perhaps 6 or more years after a single, successful mating. In some cases, it is possible to have an infertile clutch followed by a fertile clutch without further matings.

# The sex of a turtle is determined by the temperature at which the egg is incubated, with warmer temperatures producing females, cooler temperatures producing males and temperatures in the middle resulting in a mixed clutch. The situation is reversed for crocodiles, with males predominating at higher temperatures. The gender of a snake is determined by chromosomes, as it is in the case of mammals and birds.

# Reptiles do not have sweat or sebaceous glands; therefore, they are not slimy. They are, however, waterproof, and this, in addition to lacking a metamorphic stage is one of the distinctions between amphibians and reptiles (tadpoles metamorphose, or change, into frogs). The reptilian egg, with calcium in its shell is not dependant on development in water, as is the amphibian egg.

# Reptiles are not "cold blooded"; rather they are ectothermic animals, which rely on heat to be provided by the environment, as they produce little of their own. Behavior, such as seeking shade, gaping and shunting blood toward or away from the body surface allows impressively fine control of body temperature several degrees above or below the ambient temperature. When housed in suitable environments, most reptiles when active, maintain a body temperature similar to that of mammals.


Interesting Facts About New Brunswick

· New Brunswick is the largest of Canada’s three Maritime provinces. New Brunswick is 73,440 sq. km (28,354 sq. mi.).

· There are three distinct coastlines in New Brunswick that together span 2,250 km (1,398 mi.).

· The province has eight cities, Saint John, Moncton, Dieppe, Fredericton (Capital), Edmundston, Campbellton, Bathurst and Miramichi.

· The population of New Brunswick is 749,200.

· New Brunswick is Canada’s only officially bilingual province (1969) (French and English).

· New Brunswick’s Bay of Fundy has the highest tides on earth and is one of the most accessible viewing areas for marine life in the world.

· The St. John River system is the second largest on North America’s Atlantic coastline and extends from the northwest point of the province to the southern coast, where it empties into the Bay of Fundy at Saint John.

· Fiddleheads, edible, tightly coiled ferns that resemble the spiral end of a violin or fiddle, are a New Brunswick delicacy. Freshly picked from the riverbanks in the early spring, they are wonderful served with Atlantic salmon!

· New Brunswick has many species of birds. Grand Manan Island in the Fundy Isles is one of the top birding spots in North America. Grand Manan Island is also the Dulse Capital of the World. Dulse is an edible dried seaweed with many healthy properties, containing many minerals and a variety of vitamins.

· New Brunswick has more than 48 lighthouses and is famous for its existing inland lighthouse system that dots its inland rivers.

· The Bay of Fundy is a pristine sanctuary for all kinds of rare, unusual wild creatures. Immense blooms of plankton provide a vast feeding ground for up to 15 species of toothed and baleen whales, including Finbacks, Humpbacks, Pilot whales and the rare Right whale.

· Although New Brunswick has 64 remaining covered bridges, Kings County is considered the Covered Bridge Capital of Atlantic Canada. The bridges that are standing today are living examples of the pride of craftsmanship, heritage, engineering and design of our forefathers. The ‘’Longest Covered Bridge in the World’’ is located in Hartland, New Brunswick - 390 m. (1,282 ft.) long.

· New Brunswick has some of the warmest saltwater beaches north of Virginia.

· New Brunswick is accessible by major airports and highways, as well as by cruise ship, ferry and by rail.

· The Appalachian Range is one of the oldest mountain ranges on earth.

· Ganong Brothers Ltd. created the first chocolate and nut candy bar by individually wrapping pieces of chocolate and selling them for a nickel.

· Manufacturing, mining and forestry are the main industries, and the province is considered a North American leader in forest management.


Interesting Facts about Queen Elizabeth I

There are many interesting facts that surround the life of Queen Elizabeth I - some are based on facts and some are based on fiction! Some are interesting facts, some are strange facts and some are down right weird facts! The Virgin Queen was interesting! Check out our Top 10 Facts on Queen Elizabeth I!

Top 10 Facts About Queen Elizabeth I

Trivia Fact 1 - Queen Elizabeth I was born 7 September 1533 at Greenwich Palace

Trivia Fact 2 - The Father of Queen Elizabeth I was the nororious King Henry VIII

Trivia Fact 3 - The Mother of Queen Elizabeth I was Anne Boleyn

Trivia Fact 4 - Queen Elizabeth I Died on 24 March 1603 (of blood poisoning) - she was nearly 70 years of age

Trivia Fact 5 - Queen Elizabeth I Reigned for 45 years from 1558 - 1603

Trivia Fact 6 - Her mother, Anne Boleyn, was accused of adultery and incest ( with her brother George Boleyn) and was beheaded at the Tower of London

Trivia Fact 7 - Princess Elizabeth lived with her stepmother Katharine Parr and her husband Thomas Seymour - she was sent away in disgrace amid rumours that she was having an affair with Seymour!

Trivia Fact 8 - Scandal followed Queen Elizabeth I when Amy Robsart, the wife of her favourite courtier Robert Dudley (some say lover) was found dead at the foot of her stairs - Dudley was suspected or arranging her murder so that he would be free to marry Queen Elizabeth

Trivia Fact 9 - Queen Elizabeth almost died of Smallpox in 1562 and was left with scars on her face - these were covered with the heavy white make-up which was fashionable at the time

Trivia Fact 10 - She never met her cousin and rival, Mary Queen of Scots, although she was imprisoned in England for many years


Interesting Facts About Amateur Radio

The oldest radio service
Amateur's have been around since the beginning of radio itself. Many individuals built, communicated and experimented with radio. They communicated using Morse code, that strange configuration of dits and dahs still holds the fascination of many operators today. Amateur's , or "hams" as we are known, have been at the forefront of radio technology. Many hams have pioneered the art of radio and provided experimentation which has led to many of today's high tech. communication capabilities. A good example of this experimentation is communicating thru a PC. Hams also communicate with computers, but instead of using the phone lines to transfer the information, we send the information over the air waves using HF or VHF/UHF radio equipment. An example of computer communication on the amateur radio bands, is called "RTTY" , which stands for Radio TeleType , better known as simply teletype. RTTY is a very fun mode of communication, and much simpler to participate in with the advent of the desk top personal computer. Another example is called "packet", whereby "packets" of information are sent at the same time, arrive at their destination, then wait for a reply. There is a whole network across the country linked together via VHF/UHF repeaters to carry messages back and forth thousands of miles away.

Who can become a "ham"
Anyone may receive an FCC Amateur Radio License, called a "ticket" by ham's. There are no age limits, you just need to demonstrate the ability to receive morse code at a minimum speed of five words per minute, as well as pass a written exam covering rules and regulations, electronic theory and good operating practices. There are six different "classes" or levels of amateur radio license's , novice, technician, technician plus, general, advanced and extra. Each class has a different requirement for obtaining that level of license. The different levels of license's allow the operator different operating privileges, the higher the class, the more privileges you obtain . Recently, the FCC has created a class of license ( technician ) that no longer requires the ability to receive morse code. Of course your operating privileges are very limited with this entry level class. I won't go into what each classes privileges are here. Check out the ARRL's home page for more information

WorldWide Communications
With the proper equipment, hams can communicate with other hams around the globe, around the clock. Propagation is a fascinating aspect to radio communication, many hams study the solar activity and try to predict the best openings for a particular band at a given time of day. This helps in setting up schedules with others in different parts of the country, or world. As well as giving you a pretty good idea what part of the world you should be hearing and on what band you should be hearing it ! The sun and the rays it emits have been studied for many years, even before radio was "invented". Scientist's discovered many years ago that the sun developed spots on its face, called sunspots. They also learned that in some years the sun would develop more sunspots than in others. These sunspots are cooler area's on the sun's surface, or face. Tracking these sunspots lead to the finding that the sun goes through a cycle every eleven years ( called the solar cycle or 11 year cycle ). As each year went by , the sun would gain more spots. Then at the peak of the cycle, the spots would start to decline in numbers and start the whole process all over again. After the advent of radio, came the realization that as the solar cycle reached its peak, radio communication with distant stations became easier. Signals become very strong and communicating with someone on the other side of the world was just as easy as with someone across town ! Furthermore, communications on bands which were once thought of as worthless were providing communications on a regular basis , during these "peaks" in the cycle. It is truly amazing how far your signal can go during the peak of the solar cycle with very little power ( watts ) out ! Of course during the declining years, communications become poor, if not impossible, on some bands.

Exchanging "postcards"
One popular activity among hams includes the exchanging of postcards, called "QSL" cards. The purpose is to confirm that two way communication was made between the two stations. These cards contain information about the operator, such as name, call sign, location, etc. As well as information about the contact, band , mode, time of day , date . Most hams have their own personal cards printed by professional printers. Some cards are very creative, some are just "plain jane", but they are always fun to receive in the mail. Some examples include: hand drawn designs, photo's of the operating station and the owner, even pictures of tropical islands with crystal blue water and white sandy beaches ! Some cards are highly sought after, hams will travel to remote islands or countries which have little or no amateur radio activity , then offer QSL cards to everyone who contacts them. It is not unusual for these "DXpeditions" , as they are called, to make many thousands of contacts with other hams around the world in a weekend ! QSL cards are a fun way of keeping track of all the different countries or places one has talked to. They are also required for many of the awards that are offered hams.

Pick a mode, any mode...
Just about every mode of communication available today is used by amateurs. Some of them include, AM, FM, SSB, CW. Hams can even send TV pictures across the country or around the world ! All forms of digital communication are used as well, computers have become a communication tool used by most of the hams today.

Through the efforts of the "AMSAT" organization, amateur satellite communications have been a reality since the early sixties. Hams enjoy satellite communication on a daily basis. Imagine the thrill and excitement of "working" other hams around the world using minimum power as the "bird" orbits overhead ! Satellite tracking is an activity in and of itself and is very challenging, just figuring it all out has its rewards. Some amateurs even bounce their signals off of the earth's biggest satellite, the MOON !

Space Shuttle Communication
There have been a number of Astronauts who are also "hams" that have been allowed to experiment, while on a Shuttle mission, with amateur radio. They have communicated with other hams on earth. Many hams have set up stations in schools to demonstrate to the students, amateur radios ability to communicate with the shuttle astronauts. The equipment usually is a simple VHF/UHF handheld "HT" running only a few watts of output power. Can you imagine talking with an astronaut who is orbiting the earth at 17k + MPH ?

Low Power (QRP) Operation
While many amateur's are allowed to run up to 1500 watts, there is a growing interest in low power operation. Commonly referred to as "QRP", individuals who find this aspect of the hobby challenging, enjoy building or "homebrewing" their own radios and receivers. There are many ham's who have made contact with others around the world using only a few watts of power, in some cases milliwatts ! The most popular mode for QRP operation is CW, due to its ability to be heard under extreme band conditions and low signal strength. The rigs sometimes can be very small in size, some have built transmitters inside of tuna fish can's ( tuna removed ) , while others have used "Altoids" tins ! Some of these radios are really creative, and can be taken just about anywhere, on camping trips, hiking, bike riding etc. Many awards are issued with the "QRP" endorsement, showing that the operator was using limited power and therefore making it harder ( more challenging ) on him/herself !

Emergency communications
Amateur's provide emergency communications whenever the need arises. Ham's have been the sole means of communication in many instances during a catastrophe. Floods, earthquakes, hurricanes, tornadoes etc. Whenever the phone lines or power is out , hams are still able to summon help to the area that is affected with the disaster. There is an annual event called "Field-Day", where hams participate in emergency type operating conditions, such as battery powered , make shift antenna's supported in trees, operating from car's, tent's, travel trailers etc. This and other event's like it, help to prepare individuals for the real thing.

Operating awards
Amateurs may earn various awards for different operating activities. Some of which include the "WAS" award, for Worked All States, this award is issued to ham's who make contact with other ham's in each of the fifty states. There are many endorsements available for this award, such as working fifty states on CW, SSB etc. Working fifty states on all bands, or just one band, like six meters. Most newly licensed ham's work on their WAS award as soon as they start making contacts, a new state is always fun to work and it can be quite a challenge, as some states are harder to find than others. Other awards include, DXCC, WAC and WPX to name just a few. There is even an award for working all of the counties in the U.S. ! Some radio clubs even offer operating awards for working members of the club. You could spend a lifetime trying to collect all of the awards that are out there !


Interesting Facts About Tape Measures

The tape measure has evolved into a much modern process of getting measurements. It developed from the ribbon type to the most modern digital and laser technology capable of measuring in the most accurate method.

Tape measures are similar to rulers but, the difference is that it can be folded or rolled. They are commonly used for dressmaking and tailoring. They are made up of ribbon, cloth, plastic, or metal. Tape measures consist of linear measure marking in metric and imperial units. Carpenters or construction workers also make use of tape measures made up of thin metallic ribbon that remains straight. The metallic ribbon retracts into a small convenient storage. Surveyors also utilize tape measures with a hectometer as its measuring unit.

A unique feature prevalent to most tape measures is a small diamond which is embedded every 19.2 inches. It is called black truss marking. Measuring tapes are ideal measuring tools because of its flexibility which can be used to measure even tight corners and curves. It can also be carried in a pocket because of its small size.

This measuring tool comes in different types:

Body Measuring Tape

This type of measuring tape can be used to measure circumference of the head, waist, legs and arms of the body. One of the models of this type is the Quick Medical QM2000 Measure Mate Body. It features accurate and quick measurements. Another good feature of this tool is that it can measure up to 60 inches and has automatic retracting system. In addition, measurement readings are shown on both sides of the tape. For a more accurate measurement, a 0.1 cm increment is used with this tool.

Measuring with the Measure Mate is simple. Just wrap the retracting tape around the area which you want to measure and then put the end into position. Afterwards, just push on the button and it automatically locks into position.

Adhesive Measuring Tape

This type of tape measure comes with an adhesive that allows it to be removed and positioned on almost any surface. The tape can be written with marking pens or pencil. It is 1 inch wide and 100 inches long and is colored white with black numeral markings. This is mostly used by police investigators or Scene of the Crime Operatives (SOCO). It is ideal in measuring blood splatter on any surface, bullet holes, or any pieces of evidence for crime scenes.

Magnetic Measuring Tape

The magnetic measuring tape is ideal for measuring metal surfaces. It is made up of vinyl material with a UV resistant red and blue ink. It is one meter long and uses standard and metric measurement system.

Laser Measuring Tape

This type of measuring device is one of the latest advancements in measuring technology. This device can be manipulated to accurately measure length, width, distance, area, and volume. Basically, it is used by interior designers, architects, and craftsmen. The great feature of this device is that it is able to measure hard to reach objects such as buildings and billboards if it is 300 feet in distance.

The TLM100 is one of the models of this kind of measuring tool. With its point and shoot technology, it can measure quickly and precisely without having a need for an assistant. Plus, it lessens the burden of having to calculate a lot of measurements. Some of the latest models include LCD display and Bluetooth technology for fast and easy data transfer.

Digital Measuring Tape

It features an LCD that displays the measurement made. Measurements can be made in inches, feet, and even fraction measurements. The measuring device automatically switches on when the tape is extended. It will turn off when the tape is retracted into its case. The measuring tape operates with the use of two LR44 batteries.

Most of the modern spring tape measures are design based on the patent by Alvin J. Fellows on July 14, 1868. The spring tape measure has existed ever since Fellow's patent. It was not widely used during that time. But in 1940, it slowly emerged and supplemented in the form of the folding ruler.

Having a proper tool for measuring jobs requiring the most exact measurement is important. The slightest inaccuracy in measurements can cause a big difference and may lead to waste of time and material. This is especially true in woodworking, tailoring, and architecture. To achieve the best results, accuracy is necessary.


Interesting Facts About Turtle

There's a lot to admire about turtles and tortoises. They seem to have a steadfast character, and a plodding yet undeniable gait that sooner or later gets them to where they are going. Here are some other facts about these creatures that may make you scratch your shell in wonder.

# Testudo, the Latin word for tortoise, shell, arch or vault, was also the name given to a technique used by Roman soldiers in warfare. Standing close together, in the shape of a rectangle, they held their shields flat over their heads, to form a protective dome, allowing them to approach the enemy en masse, unharmed by spears, stones and arrows.

# The black soft-shelled turtle figures importantly in Hindu mythology. The animals are believed to represent the souls of long ago sinners, transformed into reptiles by a 13th century saint, are in a tank attached to a temple in Bangladesh. Each animal is considered sacred, and so none can be removed.

# The oldest known tortoise may have been a radiated tortoise from Madagascar (Astrochelys radiata), which died in 1965. She was at least 188 years old, having been given to the Tonga royal family, by Captain Cook in 1773 or 1777.

# The Galapagos tortoise is the largest living species, weighing in some cases, over 570 pounds.

# The carapace or upper shell of the tortoise or turtle is composed of about 50 bones, which include modified ribs, vertebrae and bony skin plates. The lower shell or plastron has evolved from the clavicles or collarbones and the ribs. The bony structure joining the two is called the bridge. The shell is very much alive, not dead tissue, like nails or hair.

# The growth rings on the scutes or scales on a tortoise cannot be used to determine the animal's age with any degree of accuracy, as in most instances, growth spurts and interruptions in growth are determined largely by environmental conditions.

# In leatherback and soft-shelled turtles, the bony scutes have been replaced with tough, leathery skin.

# Some species have hinges on either the carapace or the plastron, which allow closure of the shell.

# The snapping turtle (Macroclemys sp.) has a worm-like, fleshy structure on its tongue, which it wiggles to attract fish.

# Turtles cannot protrude their tongues from their mouths, but they can smell. Flapping the loose skin under the chin or throat moves air over the Jacobsen's organ.

# Tortoises and turtles do not have teeth.

# Tortoises store sperm and have been known to produce fertile eggs three years after the last mating.

# Stupendemys geographicus was a prehistoric turtle that was 10 feet long and probably weighed 4,000 to 5,000 pounds.