Twin

Twins are two offspring produced by the same pregnancy. Twins can either be monozygotic ("identical"), meaning that they can develop from just one zygote that will then split and form two embryos, or dizygotic ("fraternal"), meaning that they can develop from two different eggs; each are fertilized by separate sperm cells.

In contrast, a fetus which develops alone in the womb is called a singleton, and the general term for one offspring of a multiple birth is multiple.

Statistics

The twin birth rate in the United States rose 76% from 1980 through 2009, from 18.9 to 33.3 per 1,000 births. The Yoruba have the highest rate of twinning in the world, at 45–50 twin sets (or 90–100 twins) per 1,000 live births, possibly because of high consumption of a specific type of yam containing a natural phytoestrogen which may stimulate the ovaries to release an egg from each side.

In Central Africa there are 18–30 twin sets (or 36–60 twins) per 1,000 live births. In Latin America, South Asia, and Southeast Asia, the lowest rates are found; only 6 to 9 twin sets per 1,000 live births. North America and Europe have intermediate rates of 9 to 16 twin sets per 1,000 live births.

Guest appearance

In show business, a guest appearance is the participation of an outsider performer (such as a musician or actor) in an event such as a music record or concert, show, etc., when the performer does not belong to the regular cast, band or other performing group. In music, such an outside performer is often referred to as a guest artist. In performance art, the terms guest role or guest star are also common, the latter term specifically indicating the guest appearance of a celebrity. The latter is often also credited as "special guest star" or "special musical guest star" by some production companies. A guest character is a character being portrayed within a fictional entertainment setting who is only involved as part of the plot once or a few times at most. A guest character has fewer appearances than main characters, supporting characters, and recurring characters.

In pop music, guest appearances are often described with the words featuring, with, or and. It is abbreviated in credit lists as feat., ft., f/, f.. In a television series, a guest star is an actor who appears in one or a few episodes. In radio and television shows, a guest star is a guest of the show who is a celebrity.

Coffee

Coffee is a brewed drink prepared from roasted coffee beans, which are the seeds of berries from the Coffea plant. The plant is native to subtropical Africa and some islands in southern Asia. The plant was exported from Africa to countries around the world and coffee plants are now cultivated in over 70 countries, primarily in the equatorial regions of the Americas, Southeast Asia, India, and Africa. The two most commonly grown are the highly regarded arabica, and the less sophisticated but stronger and more hardy robusta. Once ripe, coffee beans are picked, processed, and dried. Dried coffee beans are roasted to varying degrees, depending on the desired flavor. Roasted beans are ground and brewed to produce coffee as a beverage.

Coffee is slightly acidic and can have a stimulating effect on humans because of its caffeine content. Coffee is one of the most popular drinks in the world. It can be prepared and presented in a variety of ways (e.g., espresso, cappuccino, cafe latte, etc.). It is usually served hot, although iced coffee is also served. Clinical studies indicate that moderate coffee consumption is benign or mildly beneficial in healthy adults, with continuing research on whether long-term consumption inhibits cognitive decline during aging or lowers the risk of some forms of cancer.

Mathematics

Mathematics (from Greek μάθημα máthēma, “knowledge, study, learning”) is the study of topics such as quantity (numbers),structure,space, and change. There is a range of views among mathematicians and philosophers as to the exact scope and definition of mathematics.

Mathematicians seek out patterns and use them to formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proof. When mathematical structures are good models of real phenomena, then mathematical reasoning can provide insight or predictions about nature. Through the use of abstraction and logic, mathematics developed from counting, calculation, measurement, and the systematic study of the shapes and motions of physical objects. Practical mathematics has been a human activity for as far back as written records exist. The research required to solve mathematical problems can take years or even centuries of sustained inquiry.

Rigorous arguments first appeared in Greek mathematics, most notably in Euclid's Elements. Since the pioneering work of Giuseppe Peano (1858–1932), David Hilbert (1862–1943), and others on axiomatic systems in the late 19th century, it has become customary to view mathematical research as establishing truth by rigorous deduction from appropriately chosen axioms and definitions. Mathematics developed at a relatively slow pace until the Renaissance, when mathematical innovations interacting with new scientific discoveries led to a rapid increase in the rate of mathematical discovery that has continued to the present day.

Remix

A remix is a piece of media which has been altered from its original state by adding, removing, and/or changing pieces of the item. A song, piece of artwork, book, video, or photograph can all be remixes. The only characteristic of a remix is that it appropriates and changes other materials to create something new.

Most commonly, remixes are associated with music and songs. Songs are remixed for a variety of reasons: