Tuesday, December 25, 2007

Bullet

A bullet is a rock-hard projectile propelled by a firearm or air gun and is normally made from metal (usually lead). A bullet (in contrast to a shell) does not contain explosives, and damages the intended target solely by imparting kinetic energy upon impact. Modern bullets for firearms are generally part of a cartridge, also known as a round. In contrast, bullets for air guns are not part of a cartridge. The word "bullet" is sometimes used to refer to the grouping of bullet, case, gunpowder and primer more properly known as a cartridge or round.; the Oxford English Dictionary definition of a bullet is "a projectile of lead ... for firing from a rifle, revolver etc."

Monday, December 17, 2007

JAR Files

A JAR file has a manifest file situated in the path META-INF/MANIFEST.MF. The entries in the manifest file conclude how the JAR file will be used. JAR files which are intended to be executed as separate programs will have one of their classes specified as the "main" class. The obvious file would have an entry such as

Main-Class: myPrograms.MyClass

Such JAR files are characteristically started with a command similar to

java -jar foo.jar

These files can also include a Classpath entry, which identifies other JAR files to be overloaded with the JAR. This entry consists of a list of absolute or relation paths to other JAR files. Although intended to simplify JAR use, in practice, it turns out to be infamously brittle as it depends on all the relevant JARs being in the exact locations specified when the entry-point JAR was built. To change versions or locations of libraries, a new manifest is required.

Wednesday, December 12, 2007

JAR

In computing, a JAR file (or Java ARchive) file used to deal out a set of Java classes. It is used to store compiled Java classes and connected metadata that can constitute a program.

* WAR (file format) (Web Application aRchive) files are also Java archives which store XML files, java classes, Java Server Pages and extra objects for Web Applications.

* EAR (file format) (Enterprise ARchive) files are also Java archives which store XML files, java classes and additional objects for Enterprise Applications.

* RAR (file format) (Resource Adapter aRchive) files are also Java archives which store XML files, java classes and added objects for J2EE Connector Architecture (JCA) applications.

JAR files can be created and extracted by the "jar" command that comes with the JDK. It can be done using zip tools, but as WinZip has a custom of renaming all-uppercase directories and files in lower case, this can raise support calls with whoever shaped the JAR or the tool authors themselves. WinRAR, on the additional hand, retains the original case of filenames.

Tuesday, December 04, 2007

Grape

A grape is the non-climacteric fruit that grows on the permanent and deciduous woody vines of the folks Vitaceae. Grapes develop up in clusters of 6 to 300, and can be black, blue, golden, green, purple, red, pink, brown, peach or white. They can be eaten raw or used for producting jam, grape juice, jelly, wine and grape germ oil. Development of grapevines occurs in vineyards, and is called viticulture. One who studies and practises increasing grapes for wine is called a viticulturist. The leaves of the grape vine itself are painstaking safe to eat and are used in the production of dolmades

Monday, November 26, 2007

Lighthouse of Alexandria

The Pharos of Alexandria was a large tower built in the 3rd century BC (between 285 and 247 BC) on the island of Pharos in Alexandria, Egypt to give out as that port's landmark, and later, its lighthouse.

With a height variously expected at between 115 and 150 meters (383 - 450 ft) it was among the tallest man-made structures on Earth for many centuries, and was recognized as one of the Seven Wonders of the World by Antipater of Sidon. It was the third big and tallest building after the two Great Pyramids (of Khufu and Khafra) for its whole life. Some scientists calculate approximately a much taller height exceeding 180 metres that would make the tower the tallest building up to the 14th century.

Monday, November 19, 2007

Traffic Claming

Traffic calming is a set of strategies used by urban planners and traffic engineers which aims to slow down traffic and get better safety for pedestrians and bicyclists, although some of these features can also be hazardous to cyclists. It is now comparatively common in Europe, especially Northern Europe; less so in North America.Traffic calming has conventionally been justified on the grounds of pedestrian safety and reduction of noise and local air pollution which are side effects of the traffic. However, it has become more and more apparent that streets have many social and recreational functions which are severely impaired by fast car traffic. For much of the twentieth century, streets were designed by engineers who were charged only with ensuring traffic flow and not with development other functions of streets. The rationale for traffic reassuring is now broadening to include designing for these functions.

Monday, November 12, 2007

Bareboat charter

A bareboat charter is an arrangement for the hiring of a boat, whereby no crew or provisions are contained as party of the agreement; instead, the people who rent the boat from the owner are responsible for taking care of such things.

There are legal differences between a bareboat charter and another types of charter arrangement, such as crewed or luxury yacht charter, commonly called time or voyage charters. In these charters the charterer can direct where the ship will go but the owner of the ship tells possession of the ship through its employment of the master and crew. In a bare-boat or demise charter, on the other hand, the owner gives possession of the ship to the charterer and the charterer retriew its own master and crew. The bare-boat charterer is sometimes known as a "disponent owner".

Monday, November 05, 2007

Banana boat

A banana boat (or a boat made of bananas), often referred to simply as a banana, is an unpowered recreational boat designed to be pulled by a bigger boat. Riders sit astride a big tube which is supported by two smaller tubes which provide balance and footrests, permit them to experience some of the thrill of moving fast and close to the water much more easily and safely than by water-skiing or surfing and they are therefore a popular ride for children. Many large motor yachts or luxury yachts have a banana as one of their onboard "toys", but any powered boat can pull a banana, and they are sometimes available as a commercial ride at holiday resorts. Most models seat middle of three and ten people. Two models with two seating tubes side by side are available. Banana boats are often yellow and are sometimes actually builted into the shape of a banana.

Monday, October 29, 2007

Types of boats

Airboat

Airboats are needlly flat-bottomed vessels propelled in a forward direction by an aircraft type propeller and powered by either an aircraft or automotive engine. The engine and propeller are covered in a protective metal cage that prevents objects, i.e., tree limbs, branches, clothing, beverage containers, wildlife from coming in contact with the whirling propeller, which could cause devastating falt to the vessel and traumatic injury to the operator and passengers.

The propeller gives a rearward column of air that propels the airboat forward. Steering is accomplished by forced air passing across vertical rudders. There must be a forceful airflow in order to the vessel to be steered. Airboats not have brakes and are incapable of traveling in reverse. Stopping and reversing direction are dependent upon operator/pilot/driver skill.

Monday, October 22, 2007

Parts of a boat

The roughly horizontal, but cambered structures spanning the hull of the boats are reffer to as the "deck". In a ship there are often many, but a boat is unlikely to have more than one. The similar but generally lighter structure which spans a raised cabin is a coach-roof. The "floor" of a cabin is properly known as the sole but is more likely to be called the floor. (A floor is properly, a structural member which ties a frame to the keelson and keel.) The underside of a deck is called the deck head. The keel is a lengthwise structural member to which the frames are constant one (sometimes referred to as a backbone). The vertical surfaces splitting the internal space are known as bulkheads. The front of a boat is known as the bow or prow. The rear of the boat is known as the stern. The right side of the boat is called starboard and the left side of the boat is called port.

Monday, October 15, 2007

ship
Usually a ship has enough size to carry its own boats, such as lifeboats, dinghies, or runabouts. A rule of thumb is "a boat can fit on a ship, but a ship can't fit on a boat". Consequently submarines are referred to as "boats", because early submarines were little enough to be carried aboard a ship in transit to distant waters. Other types of big vessels which are traditionally called boats are the Great Lakes freighter, the riverboat, and the ferryboat. Though big enough to carry their own boats and/or heavy cargoes, these examples are designed for operation on inland or protected coastal waters. Often local law and regulation will define the correct size (or the number of masts) which a boat requires to become a ship. Nautical meaning is related to sailors, particularly customs and practices at sea. Naval is the adjective pertaining to ships, step by step in common usage it has come to be more particularly associated with the noun "navy".

Monday, October 08, 2007

Boat
A boat is a watercraft designed to plane on, and provide transport over, water. However, boats such as the whaleboat were designed to be operated from a ship in an offshore environment. In Naval terms, a boat is small enough to be carried aboard another vessel (a ship). Boats that are notable exceptions to this concept due to their large size are the riverboat, narrowboat and ferryboat. These examples do, however, generally operate on inland , protected coastal waters. Modern submarines may also be referred to as boats but this is possibly due to the fact that the first submarines could be carried by a ship and were certainly not capable of making offshore passages on their own. Boats are may have military, other government, research, or commercial usage.

Monday, September 24, 2007

Krill fishery

Krill fishery is the profitable fishery of krill, small shrimp-like marine animals that live in the oceans world-wide. Estimates for how much krill there is vary wildly, depending on the methodology used. They range from 125–725 million tones of biomass globally. The total global harvest of krill from all fisheries amounts to 150 – 200,000 tones annually, mainly Antarctic krill (Euphausia superb) and North Pacific krill (E. Pacifica).

Krill are rich in protein (40% or more of dry weight) and lipids (about 20% in E. superb). Their exoskeleton amounts to some 2% of dry weight of chitin. They also contain traces of a wide array of hydrolytic enzymes such as proteases, carbohydrates, nucleases and phospholipids, which are intense in the digestive gland in the cephalothoraxes of the krill.

Monday, September 17, 2007

Biotic pollination

It occurs when pollination is mediated by an organism, termed a pollinator. Entomophily, pollination by insects, often occur on plants that have urbanized blue petals and a strong scent to attract insects such as, bees, wasps and rarely ants (Hymenoptera), beetles (Coleoptera), moths and butterflies (Lepidoptera), and flies (Dipteral). In Zoophily, pollination is done by vertebrates such as birds and bats, mainly, hummingbirds, sunbirds, spider hunters, honeyeaters, and fruit Bats. Plants modified to this strategy tend to develop red petals to attract birds and rarely develop a scent because few birds have a sense of smell.

Monday, September 10, 2007

Rainbow

Rainbows are optical and meteorological phenomena that reason of a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere. They take the form of a multicolored arc, with red on the external part of the arch and violet on the inner section of the arch. More rarely, a secondary rainbow is seen, which is a second, fainter arc, outside the primary arc, with colours in the differing order, that is, with violet on the outside and red on the inside.

A rainbow spans a permanent spectrum of colours. Traditionally, however, the chain of colours is quantized. The majority cited and remembered sequence, in English, is Newton's sevenfold red, orange, yellow, green, blue, indigo and violet. "Roy G. Biv" and "Richard of York Gave Battle In Vain" are admired mnemonics.

Though rainbows are bow-shaped in most cases, there are also phenomena of rainbow-colored flooring in the sky: in the shape of stripes, circles, or even flames

Tuesday, September 04, 2007

water taxi

A water taxi or river taxi or aquatically disposed taxi is a boat used for public transportation in cities with plentiful water channels. Many cities, including New York City, Boston, Baltimore, Fort Lauderdale, Winnipeg, Vancouver, London, and Tokyo have planned water taxis that operate in a similar manner to ferries or buses. Others, like Venice, have for-hire boats like to traditional taxis. Venice also has a vaporetto or waterbus system that operates in the same way to American "water taxis" (image).
Water taxis also activate in cottage areas where some cottages are available only by water. Visitors can drive to a local marina and take a water taxi to the final purpose.
On March 6, 2004, a "Seaport Taxi," a water taxi service operated by the Living Classrooms Foundation, capsized through a storm near Baltimore's Inner Harbor; 5 passengers died in the accident.

Monday, August 27, 2007

Tomato

The tomato (Solanum lycopersicum) is a plant in the Solanaceae or nightshade family, as are its close cousin’s tobacco, chili peppers, potato, and eggplant. The tomato is subject to Central, South, and southern North America from Mexico to Peru. It is a perennial, often grown outdoors in temperate climates as an annual, typically attainment to 1–3 m (3 to 10 ft) in height, with a weak, woody stem that often vines over other plants.

The leaves are 10–25 cm long, pinnate, with 5–9 leaflets, each leaflet up to 8 cm long, with a jagged margin; both the stem and leaves are thickly glandular-hairy. The flowers are 1–2 cm across, yellow, with five sharp lobes on the corolla; they are borne in a cyme of 3–12 together. The word tomato derives from an expression in the Nahuatl language, tomatl. The exact name, lycopersicum, means "wolf-peach" compare the related species S. lycocarpum, whose scientific name means "wolf-fruit", common name "wolf-apple".

Tuesday, August 21, 2007

Egypt

Egypt is officially the Arab Republic of Egypt, is a country in North Africa that includes the Sinai Peninsula, a ground bridge to Asia. Covering a region of about 1,001,450 square kilometers (386,560 square miles), Egypt borders Libya to the west, Sudan to the south, and Israel and the Gaza Strip to the northeast; on the north and the east are the Mediterranean Sea and the Red Sea, correspondingly.

Egypt is the fifteenth most crowded country in the world. The huge majority of its 78.8 million people (2006) live close to the banks of the Nile River (about 40,000 km² or 15,450 sq miles) where the only arable agricultural land is found. Large areas of land form part of the Sahara Desert and are sparsely inhabited. Around half of Egypt's residents live in urban areas, with the majority spread across the densely populated center of greater Cairo (the largest city in Africa and the Middle East), Alexandria and other major towns in the Nile Delta.

Egypt is famous for its very old civilization and some of the world's most ancient and important monuments, including the Giza Pyramids and the Great Sphinx of Giza; the southern city of Luxury contains a particularly large number of ancient artifacts such as the Karnak Temple and the Valley of the Kings. Nowadays, Egypt is extensively regarded as a main political and cultural centre of the Middle East

Monday, August 13, 2007

Blazer

A blazer or boating jacket is a kind of jacket, generally double-breasted even though single-breasted blazers have become more general in recent times. A blazer looks like a suit jacket except for that it generally has patch pockets with no flaps, and metal shank buttons. A blazer's cloth is usually of a resilient nature as it is used in schools and was used for sport. They frequently form part of the uniform dress of bodies, such as airlines, schools, yacht or rowing clubs, and private security organizations. As sporting dress has become more modified to the activity, the blazer has become limited to clubs' social meetings. Generally, blazers are navy blue, but nearly every color and mixture of colors has been used, particularly by schools and sporting organizations.

Tuesday, August 07, 2007

Infrared

Infrared (IR) emission is electromagnetic emission of a wavelength longer than that of noticeable light, but shorter than that of radio waves. The name means "below red", red being the color of detectable light of longest wavelength. Infrared radiation spans three instructions of magnitude and has wavelengths between about 750 nm and 1 mm.

These divisions are suitable by the different human response to this radiation: near infrared is the area closest in wavelength to the radiation detectable by the human eye, mid and far infrared are gradually further from the visible regime. Other definitions follow different physical mechanisms and the newest follow technical reasons .Unfortunately the international standards for these specifications are not currently obtainable.

The boundary between visible and infrared light is not precisely defined. The human eye is markedly less responsive to light above 700 nm wavelength, so longer frequencies make irrelevant contributions to scenes illuminated by common light sources. But particularly strong light (e.g., from lasers, or from bright daylight with the visible light removed by colored gels can be detected up to approximately 780 nm, and will be apparent as red light. The onset of infrared is defined at different values typically between 700 nm and 780 nm.

Monday, July 30, 2007

Software

Software basically is the distinct image or representation of physical or material position that constitute configuration to or functional identity of a machine, usually a computer. As a substance of memory, software in principle can be changed without the alteration to the static paradigm of the hardware thus without the remanufacturing thereof. Generally software is of an algorithmic form which translates into being to a progression of machine instructions. Some software, however, is relational forms which translate into being the map of a recognition network.

Software is a program that enables a computer to achieve a specific task, as contrasting to the physical components of the system. This include application software such as a word processor, which enables a user to achieve a task, and system software such as an operating system, which enables other software to run suitably, by interfacing with hardware and with other software.

Tuesday, July 24, 2007

Metabolism

Metabolism is the total set of chemical reactions that occur in living cells. These processes are the source of life, allowing cells to grow and reproduce, maintain their structures, and react to their environments. Metabolism is frequently divided into two categories. Catabolic reactions yield energy, an example being the stop working of food in cellular respiration. Anabolic reactions, on the other hand, use this energy to construct mechanism of cells such as proteins and nucleic acids.

The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is distorted into another by a series of enzymes. Enzymes are vital to metabolism because they allow cells to drive desirable but thermodynamically unfavorable reactions by combination them to favorable ones. Enzymes also agree to the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.

Monday, July 16, 2007

Robotics

It is the science and technology of robots, their plan, manufacture, and application.Robotics requires functioning information of electronics, mechanics, and software. A person functioning in the field is a roboticist. The word robotics was first used in issue by Isaac Asimov, in his science fiction short story "Runaround" (1941).

Although the outside and capabilities of robots vary extremely, all robots share the features of a mechanical, movable structure under some form of control. The chain is misshapen of links, actuators and joints which can allow one or more degrees of freedom. Most modern robots use open sequential chains in which each link connects the one before to the one after it. These robots are called serial robots and often look like the human arm. A few robots, such as the Stewart platform, use closed parallel kinematic chains. Other structures, such as those that imitate the mechanical structure of humans, diverse animals and insects, are relatively rare. However, the development and use of such structures in robots is a dynamic area of research. Robots used as manipulators have a finish effector mount on the last link. This end effector can be something from a welding mechanism to a mechanical provide used to manipulate the environment.

Wednesday, July 11, 2007

Hardware and software design

Supercomputers using custom CPUs traditionally gained their speed over conventional computers through the use of innovative designs that allow them to carry out many tasks in parallel, as well as complex feature engineering. They tend to be expert for certain types of computation, usually numerical calculations, and perform poorly at more general computing tasks. Their memory hierarchy is very cautiously designed to ensure the processor is kept fed with data and commands at all times—in fact, much of the performance difference between slower computers and supercomputers is due to the memory hierarchy. Their I/O systems tend to be planned to support high bandwidth, with latency less of an issue, because supercomputers are not used for transaction processing.

As with all highly parallel systems, Amdahl's law applies, and supercomputer designs devote great effort to eliminate software serialization, and using hardware to speed up the remaining bottlenecks.

Wednesday, June 06, 2007

Wherry

The Norfolk wherry is a black-sailed trader, kind of boat on The Broads in Norfolk. It is double-ended with the pole steeped well forward, tinted black with a single gaff sail. Mostly clinker-built, it would carry about 25 tons of goods.
Wherries were able to arrive at better boats just off coast and take their cargoes off to be transported inland through the broads and the rivers.
Before wherries, there was the Norfolk Keel, a quadrangle rigged, transom sterned clinker-built boat, 54 feet by 14 feet, and able to carry 30 tons of goods. The keel had been built since the middle Ages and the plan probably went back to the Viking invasion. After 1800, the Norfolk Keel (or 'keel wherry') disappeared, partly since a wherry could be sailed with fewer crew, and it had limited maneuverability and lacked speed.
A special wherry wheelbarrow was used to unpack cargo, e.g. stone, from the wherries. It was made from wood and strengthens with iron bands. It had no legs; therefore it could be rested on the 11 inches wide plank on the surface of the wherry.

Monday, May 28, 2007

Kayak

A kayak is a little human-powered boat. It classically has a covered deck, and a cockpit covered by a spray deck. It is propelled by a double-bladed paddle by sitting paddlers. The kayak was used by the inhabitant Ainu, Aleut and Eskimo hunters in sub-arctic regions of northeastern Asia, North America and Greenland. Modern kayaks come in a wide diversity of designs and materials for particular purposes. Kayaks are frequently referred to as canoes in Great Britain and Ireland.
Traditional kayaks typically accommodate one, two or infrequently three paddlers who sit facing ahead in one or more cockpits below the deck of the boat. If used the spray deck or comparable waterproof garment attach securely to the edges of the cockpit, prevent the entry of water from waves or spray, and making it possible in some styles of boat, to roll the kayak upright again without it filling with water or eject the paddler.
Kayaks differ definitely in design and history from canoes, which are more flat-bottomed boats propel by single-bladed paddles by a kneeling paddler, even though some modern canoes may be difficult for a non-expert to distinguish from a kayak. One benefit to a kayak is that with a canoe's high bow, it is harder to paddle against the wind. As Kayaks do not have such high sides, it is easier to paddle on a breezy day.

Sunday, May 20, 2007

Hovercraft

A hovercraft, or air-cushion vehicle (ACV), is a vehicle or craft that can be hold up by a cushion of air dispossessed downwards against a surface close below it, and can in principle travel over any relatively smooth surface, such as gently sloping land, water, or marshland, while having no substantial contact with it.
Hovercraft has one or more parts of engines (some craft, such as the SR-N6, have one engine with a drive split through a gearbox). One engine drives the fan (the impeller) which is in charge for exciting the vehicle by forcing air under the craft. The air therefore must exit throughout the "skirt", lifting the craft above the area which the craft resides. One or more additional engines are used to offer thrust in order to propel the craft in the favorite direction. Some hovercraft utilized ducting to allow one engine to perform both tasks by directing some of the air to the skirt, the rest of the air passing out of the back to push the craft forward.

Sunday, May 13, 2007

Folding boat

A Folding boat is frequently a smaller boat, typically ranging between 8 to 12 feet. This style of boat must also allow for easy lifting which require a glow weight. Folding boats are made from light weight resources such as marine plywood, aluminum or more exotic man-made materials lighter and tougher than aluminum. Folding boats fill a need for people who do not have storage gap for a full-size boat or cannot transport a full-size boat.
There are more than a few folding boat makers and folding kayak makers in the world from the USA, England and Australia with several variations and models. The handyman can also produce their own unit at home with plans or buy designing their own version.
Although there is much to be thought by the advantages of a folding boat, they are not common place in boating and aluminum and inflatable alternatives are far more common despite some folding boats having been sold for several decades.

Monday, April 02, 2007

Human-powered transport

Human-powered transport is transport of person(s) and or goods motorized by human muscle.
Like animal-powered transport, human-powered transport has been in continuation since time immemorial in the form of walking, running and swimming. However modern technology has led to machines to improve human-power. Although motorization has compact the effort in transport, many human-powered machines stay popular for leisure or exercise and for short distance travel. Human-powered transport is frequently the only (reliable) power source available in underdeveloped or inaccessible regions, and may be measured an ideal form of sustainable transportation.

Wednesday, March 28, 2007

A Civil Role Model
The word civil carries a lot of power. The usage needs to be carefully considered when it's entered into a sentence or an expression. Civil means a wide difference of things. It can be defined as a way to be attentive of the forms required for good reproduction. It can also be a means to the needs and affairs of the common public. However, the latter of the two definitions can also be extended to include a definition of the private rights and the remedy sought by action or costume. The point is that the word civil has a greater significance that has been embraced by our American legal traditions. It is the premise that law is there to provide the people and the lawyers are nothing more than mere guardians of law.
These are thoughts that were measured during the class viewing of A Civil Action. In the events of the case, there were many concerns that were brought up about our permissible culture.

Tuesday, March 20, 2007

Carriage

The standard definition of a carriage is a four-wheeled horse drawn personal passenger vehicle with leaf springs or leather robust for postponement, whether light, smart and fast or large and relaxed. Compare the public conveyance stagecoach, charabanc, and omnibus.
A medium that is not sprung is a wagon. An American buckboard or Conestoga wagon or "prairie schooner" was never taken for a carriage, but a waggonette was an enjoyment vehicle, with lengthways seats.
The word car meaning "wheeled vehicle", came from Norman French at the start of the 14th century; it was absolute to cover automobile in 1896.
In the British Isles and many Commonwealth countries, a railway carriage (also called a coach) is a railroad car planned and prepared for transporting passengers.
In the United States, a baby carriage is a wheeled transportation for recline infants (in English outside North America: perambulator or pram), often with a hood that can be adjusted to protect the baby from the sun.

Sunday, January 21, 2007

Lighthouse of Alexandria

The Pharos of Alexandria was a lighthouse built in the 3rd century BC on the island of Pharos in Alexandria, Egypt to serve as that port's landmark, and later, a lighthouse. With a height variously estimated at between 115 and 135 metres it was among the tallest man-made structures on Earth for many centuries, and was identified as one of the Seven Wonders of the World by classical writers. It ceased operating and was largely destroyed as a result of two earthquakes in the 14th century AD; some of its remains were found on the floor of Alexandria's Eastern Harbour by divers in 1994. More of the remains have subsequently been revealed by satellite imaging.

Constructed from large blocks of light-colored stone, the tower was made up of three stages: a lower square section with a central core, a middle octagonal section, and, at the top, a circular section. At its apex was positioned a mirror which reflected sunlight during the day; a fire was lit at night. Extant Roman coins struck by the Alexandrian mint show that a statue of a triton was positioned on each of the building's 4 corners. A statue of Poseidon stood atop the tower during the Roman period.

Monday, January 08, 2007

Conjoined twins

Conjoined twins are monozygotic twins, whose bodies are joined together at birth. This occurs where the single zygote of identical twins fails to separate completely, and the zygote starts to split after day 13 following fertilization. This condition occurs in about 1 in 50,000 human pregnancies. Most conjoined twins are now evaluated for surgery to attempt to separate them into separate functional bodies. The degree of difficulty rises if a vital organ or structure is shared between twins, such as brain, heart or liver.

A chimera is an ordinary person or animal except that some of his or her parts actually came from his or her twin. A chimera may arise either from identical twin fetuses, or from dizygotic fetuses, which can be identified by chromosomal comparisons from various parts of the body. The number of cells derived from each fetus can vary from one part of the body to another, and often leads to characteristic mosaicism skin colouration in human chimeras. A chimera may be a hermaphrodite, composed of cells from a male twin and a female twin.

Monday, January 01, 2007

Wildlife

The term wildlife refers to living organisms that are not in any way artificial or domesticated and which survive in natural habitats. Wildlife can refer to flora but more usually refers to fauna. Wildlife is a very general term for life in ecosystems. Deserts, rainforests, plains, and other areas including the most built-up urban sites all have distinct forms of wildlife.

Humans have historically tended to split civilization from wildlife in a number of ways; besides the obvious difference in vocabulary, there are differing expectations in the legal, social, and moral sense. This has been a reason for debate during recorded history. Religions have often declared certain animals to be sacred, and in modern times concern for the environment has aggravated activists to protest the exploitation of wildlife for human benefit or entertainment. Literature has also made use of the traditional human separation from wildlife.