Tin

Organotin compounds such as tributyltin oxide are biocides and need to be handled with care. The incidence of twinning among cattle is about 1-4%, and research is underway to improve the odds of twinning, which can be more profitable for the breeder if complications can be sidestepped or managed. The small amount of tin that is found in canned foods is not harmful to humans. Multiple births are common in many animal species, such as cats, sheep, and ferrets. See also Stannous hydroxide (Sn(OH)₂), Stannic acid (Stannic Hydroxide - Sn(OH)₄), Tin dioxide (Stannic Oxide - SnO₂), Tin(II) oxide (Stannous Oxide - SnO), Tin(II) chloride (SnCl₂), Tin(IV) chloride (SnCl₄). In this case, although the twins did come from the same egg, it is incorrect to refer to them as genetically identical, since they have different karyotypes. For Stannite (SnO₃^-) see Stannite. When monozygotic twins are born with different genders it is because of chromosomal birth defects.

For discussion of Stannate compounds (SnO₃^2-) see Stannate. The probability of this is so vanishingly small (only 3 documented cases) that multiples having different genders is universally accepted as a sound basis for a clinical determination that in utero multiples are not monozygotic. 18 additional unstable isotopes are known. Among monozygotic twins, in extremely rare cases, twins have been born with opposite sexes (one male, one female). Tin is the element with the greatest number of stable isotopes (ten). One 1992 study estimates that the frequency of heteropaternal superfecundation among dizygotic twins whose parents were involved in paternity suits was approximately 2.4%; see the references section, below, for more details. Secondary, or scrap, tin is also an important source of the tin. This can lead to the possibility of a woman carrying fraternal twins with different fathers (that is, half-siblings).

The only mineral of commercial importance as a source of tin is cassiterite (SnO₂), although small quantities of tin are recovered from complex sulfides such as stannite, cylindrite, frankeite, canfieldite, and teallite. Among fraternal twins, in rare cases, the eggs are fertilised at different times with two or more acts of sexual intercourse, either within one menstrual cycle (superfecundation) or, even more rarely, later on in the pregnancy (superfetation). Most of the world's tin is produced from placer deposits; at least one-half comes from Southeast Asia. There are some patterns of twinning that are exceedingly rare: while they have been reported to happen, they are so unusual that most obstetricians or midwives may go their entire careers without encountering a single case. This metal is a relatively scarce element with an abundance in the earth's crust of about 2 ppm, compared with 94 ppm for zinc, 63 ppm for copper, and 12 ppm for lead. Twins that have been separated early in life and raised in separate households are especially sought-after for these studies, which have been invaluable in the exploration of human nature. Tin is produced by reducing the ore with coal in a reverberatory furnace. Twin studies are studies that assess identical (monozygotic) twins for medical, genetic, or psychological characteristics to try to isolate genetic influence from environmental influence.

Nearly every continent has an important tin-mining country. Many fertility treatments have no effect on the likelihood of multiple births. About 35 countries mine tin throughout the world. Some other treatments such as the drug Clomid can stimulate a woman to release multiple eggs, allowing the possibility of multiples. Likewise, so-called "tin toys" are usually made of steel, and may or may not have a small coating of tin to inhibit rust. With in vitro fertilisation (IVF), this is primarily due to the insertion of multiple embryos into the uterus. Most everyday objects that are commonly called tin, such as aluminium foil, beverage cans, and tin cans, are actually made of steel or aluminium, although tin cans do contain a small coating of tin to inhibit rust. This can vary depending on what types of fertility treatments are used.

In modern times, the word "tin" is often (improperly) used as a generic phrase for any silvery metal that comes in thin sheets. Women undergoing certain fertility treatments may have a greater chance of multiple births. The alchemical symbol for tin is shown on the left. Dizygotic twin pregnancies are slightly more likely when the following factors are present in the woman:. The American Heritage Dictionary speculates that the word was borrowed from a pre-Indo-European language. Some evidence suggests that the environment of the womb causes the zygote to split in most cases. The word "tin" has cognates in many Germanic and Celtic languages. Fewer than 20 families have been described with an inherited tendency towards monozygotic twinning (people in these families have nearly a 50% chance of delivering monozygotic twins).

However the pure metal was not used until about 600 BC. The cause of monozygotic twinning is unknown. Tin mining is believed to have started in Cornwall and Devon ( esp Dartmoor) in Classical times, and a thriving tin trade developed with the civilizations of the Mediterranean. Multiple pregnancies are usually delivered before the full term of 40 weeks gestation: the average length of pregnancy is around 36 weeks for twins, 34 weeks for triplets and 32 weeks for quadruplets. Because of its hardening effect on copper, tin was used in bronze implements as early as 3,500 BC. Before the advent of ovulation-stimulating drugs, triplets were quite rare (approximately 1 in 8000 births) and higher order births so rare as to be almost unheard of. Tin (anglo-Saxon, tin, Latin stannum) is one of the earliest metals known and was used as a component of bronze from antiquity. If there are three, they are called triplets; four, quadruplets; five, quintuplets; six, sextuplets, seven, septuplets, and so on.

A superconducting magnet weighing only a couple of kilograms is capable of producing magnetic fields comparable to a conventional electromagnet weighing tons. Sometimes multiple births may involve more than two fetuses. The niobium-tin compound Nb₃Sn is commercially used as wires for superconducting magnets, due to the material's high critical temperature (18 K) and critical magnetic field (25 T). Nevertheless, the rate of identical twins remains at about 1 in 250 across the globe, further suggesting that pregnancies resulting in identical twins occur randomly. In fact, tin was one of the first superconductors to be studied; the Meissner effect, one of the characteristic features of superconductors, was first discovered in superconducting tin crystals. Thus, approximately 6% of children born in the US in 2001 were twins. Tin becomes a superconductor below 3.72 K. In 2001, for the first time ever in the US, the twinning rate exceeded 3% of all births.

Other uses:. The widespread use of fertility drugs causing hyperovulation (stimulated release of multiple eggs by the mother) has caused what some call an "epidemic of multiple births". The tin whistle is so called because it was first mass-produced in tin-plated steel. The rate of twinning varies greatly among ethnic groups, ranging as high as about 6% for the Yoruba or 10% for a tiny Brazilian village (see [1]). One thus-derived use of the slang term "tinnie" or "tinny" means "can of beer". Historically, about 1 in 80 human births (1.2%) has been the result of a twin pregnancy. Speakers of British English call them "tins"; Americans call them "cans". Similar to vanishing twin.

Tin-plated steel containers are widely used for food preservation, and this forms a large part of the market for metallic tin. Occasionally, a woman will suffer a miscarriage early in pregnancy, yet the pregnancy will continue; one twin was miscarried but the other was able to be carried to term. Tin bonds readily to iron, and has been used for coating lead or zinc and steel to prevent corrosion. A chimera may arise either from identical twin fetuses (where it would be impossible to detect), or from dizygotic fetuses, which could be identified by chromosomal comparisons from various parts of the body. However, this transformation is affected by impurities such as aluminium and zinc and can be prevented from occurring through the addition of antimony or bismuth. A chimera is a person who is a completely normal human with no extra parts, but some of the parts actually came from his or her twin. It slowly changes back to the gray form when cooled, which is called the tin pest or tin disease. Sometimes the parasitic twin just becomes an almost indistinguishable part of the other.

When warmed above 13.2 °C it changes into white or beta tin, which is metallic and has a tetragonal structure. One fetus acts as a parasite towards the other. At low temperatures it exists as gray or alpha tin, which has a cubic crystal structure similar to silicon and germanium. Sometimes one twin fetus will fail to develop completely and continue to cause problems for its surviving twin. Solid tin has two allotropes at normal pressure. This condition occurs in about 1 in 100,000 pregnancies. Tin is malleable at ordinary temperatures but is brittle when it is heated. This occurs where the single zygote of identical twins fails to separate completely.

This metal combines directly with chlorine and oxygen and displaces hydrogen from dilute acids. Conjoined twins are monozygotic twins, whose bodies are joined together at birth. Tin can be highly polished and is used as a protective coat for other metals in order to prevent corrosion or other chemical action. Early obstetric ultrasonography exams sometimes reveal an "extra" fetus, which fails to develop and instead disintegrates and vanishes. SnO₂, in turn, is feebly acidic and forms stannate (SnO₃^-2) salts with basic oxides. Researchers suspect that more pregnancies start out as multiples than come to term that way. Tin forms the dioxide SnO₂ when it is heated in the presence of air. Such conditions are usually associated with a higher incidence of other birth defects.

Tin acts as a catalyst when oxygen is in solution and helps accelerate chemical attack. This is where some or all of the organs will be on the opposite side of the body, such as the heart being on the right(Dextrocardia). This metal resists corrosion from distilled sea and soft tap water, but can be attacked by strong acids, alkalis, and by acid salts. One mirror may or may not have situs inversus. Tin is a malleable, ductile, highly crystalline, silvery-white metal whose crystal structure causes a strange screeching sound known as the "tin cry" when a bar of tin is bent (caused by crystals breaking). They result from a late split of the fertilized egg at around 9-12 days. . The incidence of mirror twinning is comparatively rare.

Tin is obtained chiefly from the mineral cassiterite where it occurs as an oxide. These are identical twins with opposite features, that is one may be right handed and the other may be left handed; hair will whorl in the opposite direction, and so on. This silvery, malleable poor metal that is not easily oxidized in air and resists corrosion is found in many alloys and is used to coat other metals to prevent corrosion. Some percentage of monozygotic twins are called "mirror twins" or mirror image twins. Stannum) and atomic number 50. (Fraga, et al., 2005). Tin is a chemical element in the periodic table that has the symbol Sn (L. Twins who had spent their lives apart (such as those adopted by two different sets of parents at birth) had the greatest difference.

Hence one use of the slang term "tinnie" or "tinny" for a small retail package of a drug such as cannabis or for a can of beer. 50-year-old twins had over 3 times the epigenetic difference that the 3-year-old twins had. Tin foil was once a common wrapping material for foods and drugs; now replaced by the use of aluminium foil, which is commonly referred to as tin foil. The number of differences between identical twins increases with age. Although of higher melting point than a lead-tin alloy, the use of pure tin or tin alloyed with other metals in these applications is rapidly supplanting the use of the previously common lead–containing alloys in order to eliminate the problems of toxicity caused by lead. A study of 80 pairs of twins ranging in age from 3 to 74 showed that the youngest twins have relatively few epigenetic differences. Tin is also used in solders for joining pipes or electric circuits, in bearing alloys, in glass-making, and in a wide range of tin chemical applications. This is called epigenetic modification.

Window glass is most often made via floating molten glass on top of molten tin (creating float glass) in order to make a flat surface (this is called the "Pilkington process"). Identical twins have identical DNA but differing environmental influences throughout their lives affect which genes are switched on or off. These coatings have been used in panel lighting and in the production of frost-free windshields. There are usually obvious signs of differences when the identical twins are observed separately or together. Electrically conductive coatings are produced when tin salts are sprayed onto glass. Twins are unique individuals that establish their own individual likes and dislikes. The most important salt formed is tin chloride, which has found use as a reducing agent and as a mordant in the calico printing process. Many identical twins spend most of their time together (especially as children), so people often assume that they will behave alike just as they look alike; however, this is not the case.

Some important tin alloys are: bronze, bell metal, Babbitt metal, die casting alloy, pewter, phosphor bronze, soft solder, and White metal. They develop their own individual personalities to enable themselves to be identified as individual persons. Identical twins can behave as differently as any other siblings (a matter of much interest to psychologists). The exact cause for the splitting of a zygote or embryo is unknown. While it was originally thought that identical twins do not run in families, but occur more or less randomly, some recent research has suggested that a genetic predisposition may exist.

As they mature, identical twins often become less alike because of lifestyle choices or external influences such as scars. Examination of details such as fingerprints can tell them apart. (On extremely rare occasions, an original XXY zygote may form monozygotic boy/girl twins by dropping the Y chromosome for one twin and the extra X chromosome for the other.) Monozygotic twins generally look alike, although sometimes they appear as mirror images of each other. Monozygotic twins are genetically identical unless there has been a mutation in development, and they are almost always the same gender.

About 50% of mono-mono twins die from umbilical cord entanglement. These twins may develop such that blood passes disproportionately from one twin to the other through connecting blood vessels within their shared placenta, leading to twin-to-twin transfusion syndrome. Monochorionic twins, sharing one placenta, usually also share the placental blood supply. For example, the umbilical cords of monoamniotic twins can become entangled, reducing or interrupting the blood supply to the developing fetus.

Sharing the same amnion (or the same amnion and placenta) can cause complications in pregnancy. Twinning after 12 days post-fertilization will typically result in conjoined twins. Twinning between 8 to 12 days after fertilization will usually result in monochorionic-monoamniotic ("mono-mono") twins. Twinning between 4 to 8 days after fertilization typically results in monochorionic-diamniotic ("mono-di") twins.

Zygotes that twin at the earliest stages will be diamniotic and dichorionic ("di-di"). The later in pregnancy that twinning occurs, the more structures will be shared. This condition does not occur for fraternal twins. Also note that any monochorionic or monoamniotic twins are identical twins.

All monoamniotic twins are monochorionic. Diamniotic identical twins may share the same placenta (known as monochorionic) or not (dichorionic). Depending on the stage at which the zygote divides, identical twins may share the same amnion (in which case they are known as monoamniotic) or not (diamniotic). The two embryos develop into fetuses sharing the same womb.

Identical twins occur when a single egg is fertilized to form one zygote (monozygotic) but the zygote then divides into two separate embryos. However, it is only the female that has any influence on the chances of having fraternal twins as the male cannot make her release more than one ovum. Studies show that there is a genetic basis for fraternal twinning—that is, non-identical twins do run in families. Dizygotic twins may be a different sex or the same sex, just as with any other siblings.

Dizygotic twins, like any siblings, have a very small chance of having the exact same chromosome profile, but most likely have a number of different chromosomes that distinguish them. The two eggs form two zygotes, and these twins are therefore also known as dizygotic as well as "biovular" twins. Fraternal twins (commonly known as "non-identical twins") usually occur when two fertilized eggs are implanted in the uterine wall at the same time. .

Since some premature births often have health consequence to the babies, twins birth are often handled with special procedures. Due to the limited size of the mother's womb, multiple pregnancy is much less likely to carry to full term than singleton birth (twins usually around 34 to 36 weeks). A fetus alone in the womb is called a singleton. The term twin most notably refers to two individuals (or one of two individuals) who have shared the same uterus (womb) and are usually, but not necessarily, born on the same day.

Several previous pregnancies. Greater than average height and weight. Between the age of 30 and 40 years. She is of African descent.