Tuesday, June 30, 2009

Organogenesis


In animal development, organogenesis (organo-genesis, compound of the Greek words όργανον "that with which one works", and γένεσις "origin,creation,generation") is the process by which the ectoderm, endoderm, and mesoderm develop into the internal organs of the organism. Internal organs initiate development in humans within the 3rd to 8th weeks in utero.The germ layers in organogenesis differ by three processes: folds, splits, and condensation. Developing early during this stage in chordate animals are the neural tube and notochord. Vertebrate animals all differentiate from the gastrula the same way. Vertebrates develop a neural crest that differentiates into many structures, including some bones, muscles, and components of the peripheral nervous system. The coelom of the body forms from a split of the mesoderm along the somite axis.

Monday, June 29, 2009

Glossolalia

Glossolalia or speaking in tongues is the vocalizing of fluent speech-like, but unintelligible utterances, often as part of religious practice. Its use (including use in this article) also embraces Xenoglossy - speaking in a natural language that was previously unknown to the speaker.

Tuesday, June 23, 2009

Megalopolis

A megalopolis (sometimes called a megapolis) is defined as an extensive metropolitan area or a long chain of roughly continuous metropolitan areas. The term was first used in the United States by Jean Gottmann in 1957, to describe the huge metropolitan area along the Eastern seaboard of the U.S. extending from Boston, Massachusetts through New York, New York; Philadelphia, Pennsylvania; and ending in Washington, D.C. According to Gottmann, it resulted from changes in work and social habits. The concept was later extended to include the following regions: BosWash (Boston–Washington), ChiPitts (Chicago to Pittsburgh), Quebec City–Windsor Corridor, SanSan, and Bajalta California. A megalopolis is also frequently a megacity, megapolitan area, or a metropolitan area with a total population in excess of 10 million people.

Monday, June 22, 2009

Arcology


Arcology, from the words "architecture" and "ecology," is a set of architectural design principles aimed toward the design of enormous habitats (hyperstructures) of extremely high human population density. These largely hypothetical structures, called "arcologies," would contain a variety of residential and commercial facilities and minimize individual human environmental impact. They are often portrayed as self-contained or economically self-sufficient.

The concept has been primarily popularized by architect Paolo Soleri, and appears commonly in science fiction.

Sunday, June 21, 2009

hysteresis


A system with hysteresis can be summarized as a system that may be in any number of states, independent of the inputs to the system. To be exact, a system with hysteresis exhibits path-dependence, or "rate-independent memory". By contrast, consider a deterministic system with classical dynamics but no hysteresis. In that case, one can predict the output of the system at some instant in time, given only the input to the system at that instant. If the system has hysteresis, then this is not the case; one cannot predict the output without looking at the history of the input, i.e., the state of the system for a given input. In order to predict the output, one must look at the path that the output followed before it reached its current value.

Many physical systems naturally exhibit hysteresis. A piece of iron that is brought into a magnetic field retains some magnetization, even after the external magnetic field is removed. Once magnetized, the iron will stay magnetized indefinitely. To demagnetize the iron, it would be necessary to apply a magnetic field in the opposite direction. This effect is exploited commercially; for example, it provides the element of memory in a hard disk drive.

Saturday, June 20, 2009

Antinatalism


Antinatalism is the philosophical position that asserts a negative value judgment towards birth. It has been advanced by figures such as Arthur Schopenhauer, Brother Theodore and David Benatar. Schopenhauer, in his essay On the Suffering of the World articulates the position as follows:

If the act of procreation were neither the outcome of a desire nor accompanied by feelings of pleasure, but a matter to be decided on the basis of purely rational considerations, is it likely the human race would still exist? Would each of us not rather have felt so much pity for the coming generation as to prefer to spare it the burden of existence, or at least not wish to take it upon himself to impose that burden upon it in cold blood?

Similarly, Benatar argues from the hedonistic premise that the infliction of harm is generally morally wrong and therefore to be avoided, and the intuition that the birth of a new person always entails nontrivial harm to that person, that there exists a moral imperative not to procreate.

Friday, June 19, 2009

Natalism

Natalism or pro-birth is a belief that promotes human reproduction. The term is taken from the Latin adjective form for "birth," natalis.

Pronatalism or simply natalism is an ideology promoting child-bearing, which may include limited access to abortion and contraception, as well as financial and social incentives for the population, particularly natives without recent immigrant heritage, to reproduce.

Thursday, June 18, 2009

endpapers


The endpapers of a book are the leaves of paper before the title page and after the text. One part is pasted to the inside cover. They hold the text and cover together. Also called end leaf or end sheet.

overshoot

In ecology, overshoot occurs when a population exceeds the long term carrying capacity of its environment. The consequence of overshoot is called a crash or die-off. The classic application of this concept to human experience is Overshoot: The Ecological Basis of Revolutionary Change, by William R. Catton, Jr. Also see Limits to growth: The 30-year update, by Meadows, Randers & Meadows, which updates the classic 1974 book, The Limits to Growth.

Wednesday, June 17, 2009

Detritovore



Detritivores, also known as detritus feeders or saprophages, are heterotrophs that obtain nutrients by consuming detritus (decomposing organic matter). By doing so, they contribute to decomposition and the nutrient cycles.

Detritivores are an important aspect of many ecosystems. They can live on any soil with an organic component, and even live in marine ecosystems where they are termed interchangeably with bottom feeders.

Tuesday, June 16, 2009

Whoredom

Whoredom: The practice of accepting payment in exchange for sexual relations; prostitution

Monday, June 15, 2009

Thursday, June 11, 2009

Rheology


Rheology is the study of the flow of matter: mainly liquids but also soft solids or solids under conditions in which they flow rather than deform elastically.

Wednesday, June 10, 2009

Monday, June 8, 2009

Noocracy

Noocracy, or "aristocracy of the wise", as defined by Plato, is a social and political system that is "based on the priority of human mind", according to Vladimir Vernadsky. It was also further developed in the writings of Pierre Teilhard de Chardin.

Saturday, June 6, 2009

Friday, June 5, 2009

Eruv

A community Eruv (Hebrew: ערובmixture, also transliterated as Eiruv or Erub, plural: Eruvin) refers to the legal aggregation or "mixture" under Jewish religious property law of separate parcels of property meeting certain requirements into a single parcel held in common by all the holders of the original parcels, which enables Jews who observe the traditional rules concerning Shabbat to carry children and belongings anywhere within the jointly held property without transgressing the prohibition against carrying a burden across a property line on the Jewish sabbath. The legal aggregation is set up to have effect on the Sabbath day only; on other days of the week, including Yom Tov (with the exception of Yom Kippur), ordinary property ownership applies. A valid aggregation has a number of requirements including an agreement among the property-holders and an aggregation ritual.

One of the requirements of a valid aggregation is that all the parcels must lie within a chatzer, or walled courtyard. For this reason, this type of aggregation is more properly known as an eruv chatzerot (Hebrew: ערוב חצרות‎), an "aggregation of courtyards," to distinguish it from other types of rabbinically-ordained mixture procedures which also have the name eruv.

lordosis

  Lordosis is historically defined as an abnormal inward curvature of the lumbar spine.