Tuesday, May 27, 2008

Homeodynamics

"HOMEODYNAMICS - One of the dominating motifs in biological thinking was provided by the physiologist Claude Bernard in Paris in the 1850s. Bernard, who among many other discoveries carried out some of the earliest systematic studies on what were later to become known as enzymes and hormones, saw living systems as explicable neither by vitalism (the belief that there existed some special 'life forces' beyond the reach of chemistry or physics) nor by mechanism. "He regarded stability as a major organising physiological principle, and emphasised the constancy of what he described as the milieu interieur - the 'internal environment' - of multicellular organisms, their tendency to work to regulate this environment in terms of temperature, acidity, ionic composition and so forth.

This capacity he saw as providing a stable context in which the individual cells of the body can function with a minimum of disruptive turmoil. "Seventy years later the American physiologist Walter Cannon generalzed Bernard's concept by introducing the term homeostasis - the tendency of a regulated system to maintain itself close to some fixed point, like the temperature of a room controlled by a central heating system and a thermostat. No modern textbook account of physiological or psychological mechanisms fails to locate itself within this homeostatic metaphor. But the metaphor of homeostasis contrains our view of living systems. "Lifelines are not purely homeostatic: they have a beginning at conception, and an end at death. Organisms, and indeed ecosystems, develop, mature and age.

The set oints of homeostatic theory are not themselves constant during this trajectory but change over time. The organism switches its own thermostat. Organisms are active players in their own fate, not simply the playthings of the gods, nature or the inevitable workings-out of replicator-driven natural selection. To understand lifelines, therefore, we need to replace homeostasis with a richer concept, that of homeodynamics."

Monday, May 19, 2008

Adaptive system

An adaptive system is a system that is able to adapt its behavior according to changes in its environment or in parts of the system itself. A human being, for instance, is certainly an adaptive system; so are organizations and families. Some man-made systems can be made adaptive as well; for instance, control systems utilize feedback loops in order to sense conditions in their environment and adapt accordingly. Robots incorporate many of these control systems. Neural Networks are a common type of algorithmic implementation of adaptive systems.

Diffusion of innovations theory can help to explain the uptake of new ideas, practices and products by individuals and social groups -- human adaptive systems.

Monday, May 12, 2008

Microsoft Reciprocal License (Ms-RL)

This Microsoft license allows for distribution of derived code so long as the modified source files are included and retain the Ms-RL. The Ms-RL allows those files in the distribution that do not contain code originally licensed under Ms-RL to be licensed according to the copyright holder's choosing. This is equivalent to the CDDL or LGPL (GPL with a typical "linking exception"). Initially known as the Microsoft Community License, it was renamed during the OSI approval process.

On December 9, 2005, the Ms-RL license was submitted to the Open Source Initiative for approval by John Cowan. OSI then contacted Microsoft and asked if they wanted OSI to proceed. Microsoft replied that they did not wish to be reactive and that they needed time to review such a decision.

At the O'Reilly Open Source Convention in July 2007, Bill Hilf, director of Microsoft's work with open source projects, announced that Microsoft had formally submitted Ms-PL and Ms-RL to OSI for approval. It was approved on October 12, 2007 along with the Ms-PL. According to the Free Software Foundation, it is a free software license. However, unlike the Microsoft Public License, it is not compatible with the GNU GPL.

Tuesday, May 06, 2008

Norse colonization of the Americas

Norse sailors, often referred to as Vikings, explored and settled areas of the North Atlantic, including the northeast fringes of North America, beginning in the 10th century. While this settlement process did not have the lasting effects that later settlements and conquests would have, it can be seen as a prelude to wide-scale European settlement in the Americas.

The Viking activities are often erroneously described as the Viking colonization of North America, but there are few findings to support the idea that the Vikings colonized North America, except for Greenland which they occupied for almost 500 years . Outside Greenland, though, the Viking settlements only grew to a small size and never fully developed into permanent colonies, partly because of hostile relations with Native Americans, whom the Norse referred to as Skrælings. In turn, the Viking exploited the natural resources such as furs and lumber. Lumber, in particular, was in short supply in Norse Greenland, due to deforestation.

Monday, April 28, 2008

New Mobility Agenda

The New Mobility Agenda is an international institution which while virtual and an open collaborative was originally set up by an international working group meeting at the Abbey de Royaumont near Paris with the support of the OECD in Paris in 1974 to challenge old ideas and practices in the field of urban transport through a long term collaborative program of information exchange, education and peer support. The Agenda today draws together the experience, expertise and support of more than four thousand individuals and groups world wide in an open collaborative peer network. One of the original proponents of this approach, Professor Mikoto Usui then director of the OECD Development Centre, referred to it in the founding meeting at the “Abbé de Royaumont as an “invisible college”. Drawing together the experience and expertise of more than four thousand individuals and groups world wide, who are networked via a combination of websites, discussion groups and fora, and collaborative projects, the Agenda takes an approach to transportation planning, policy and practice that has gained considerable force over the last two decades -- provides a leading-edge alternative to earlier (20th century) methods of looking at and providing mobility for people and goods in cities. The Agenda has received prestigious awards for its contributions, including the Stockholm Environment Challenge Prize (2000) and the World Technology Environment Award (2002).

Monday, April 21, 2008

Population history of American indigenous peoples

Millions of indigenous people lived in the Americas when the 1492 voyage of Christopher Columbus began a historical period of large-scale European contact with the Americas. European contact with what they called the "New World" led to the European colonization of the Americas, with millions of emigrants (willing and unwilling) from the "Old World" eventually resettling in the Americas. While the population of Old World peoples in the Americas steadily grew in the centuries after Columbus, the population of the American indigenous peoples plummeted. The extent and causes of this population decline have long been the subject of controversy and debate. The 500th anniversary in 1992 of Columbus's famous voyage drew renewed attention to claims that indigenous peoples of the Americas had been the victims of ethnocides (the destruction of a culture).

Monday, April 14, 2008

Integrated development environment

In computing, an integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of a source code editor, a compiler and/or interpreter, build automation tools, and (usually) a debugger. Sometimes a version control system and various tools are integrated to simplify the construction of a GUI. Many modern IDEs also have a class browser, an object inspector, and a class hierarchy diagram, for use with object oriented software development.

Monday, April 07, 2008

Snapshot isolation

In databases, snapshot isolation is a guarantee that all reads made in a transaction will see a consistent snapshot of the database, and the transaction itself will successfully commit only if no updates it has made conflict with any concurrent updates made since that snapshot.

Snapshot isolation (SI) has been adopted by several major database management systems, such as SQL Anywhere, InterBase, Firebird, Oracle, PostgreSQL and Microsoft SQL Server. The main reason for its adoption is that it allows better performance than serializability, yet still avoids the kind of concurrency anomalies that cannot easily be worked around. SI has also been used to critique the ANSI SQL-92 standard's definition of isolation levels, as it exhibits none of the "anomalies" that the SQL standard prohibited, yet is not serializable (the anomaly-free isolation level defined by ANSI).

Friday, April 04, 2008

4th Dimension (Software)

4th Dimension (or 4D, or Silver Surfer, as it was known during early development) is a relational database management system and IDE developed by Laurent Ribardière in 1984. In 1993, 4D Server, the client/server version of 4th Dimension was introduced and since 1995, 4D has supported both the Microsoft Windows and Apple Macintosh operating systems.

The 4D product line has since expanded to an SQL front-end, integrated compiler and several productivity plug-ins and interfaces. Some of the more useful plug-ins include 4D Write (a word processor), 4D Draw (to draw shapes), 4D View (somewhat like a spreadsheet, but with extra functionality) and 4D Internet Commands (which let you add all sorts of Internet related functionality to a database). There are also over 100 third-party plugins, free and commercial.

Monday, March 24, 2008

FTPS

FTP/SSL is a name used to encompass a number of ways in which FTP software can perform secure file transfers. Each way involves the use of a SSL/TLS layer below the standard FTP protocol to encrypt the control and/or data channels. It should not be confused with either SSH file transfer protocol (SFTP), or FTP over SSH (no acronym).

The most common uses of FTP and SSL are:

* AUTH TLS, Explicit FTPS or FTPES, named for the command issued to indicate that TLS security should be used. This is the preferred method according to RFC 4217. The client connects to the server port 21 and starts an unencrypted FTP session as normal, but requests that TLS security be used and performs the appropriate handshake before sending any sensitive data.

* AUTH as defined in RFC 2228.

* Implicit FTPS is an older, but still widely implemented style in which the client connects to a different port (usually 990), and an SSL handshake is performed before any FTP commands are sent.

Monday, March 17, 2008

Spiral model

The spiral model is a software development process combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. Also known as the spiral lifecycle model, it is a systems development method (SDM) used in information technology (IT). This model of development combines the features of the prototyping model and the waterfall model. The spiral model is intended for large, expensive and complicated projects.

Sunday, March 09, 2008

NEC Display Solutions

NEC Display Solutions is a manufacturer of computer monitors and large-screen public-information displays, and has sold and marketed products under the NEC brand globally for more than twenty years. The company sells display products to the consumer, business, professional (e.g. financial, graphic design, CAD/CAM), digital signage and medical markets. The company became a wholly owned subsidiary of Japan-based NEC Corporation on March 31, 2005. Prior to that date, the company was known as NEC/Mitsubishi, a 50/50 joint venture between NEC Corporation and Mitsubishi Electric that began in 2000, and sold display products under both the NEC and Mitsubishi brands. The company, which is no longer affiliated with Mitsubishi, currently sells and markets products under the NEC brand only.

Tuesday, March 04, 2008

Molecular mechanics

In many cases, large molecular systems can be modeled successfully while avoiding quantum mechanical calculations entirely. Molecular mechanics simulations, for example, use a single classical expression for the energy of a compound, for instance the harmonic oscillator. All constants appearing in the equations must be obtained beforehand from experimental data or ab initio calculations.

The database of compounds used for parameterization, i.e., the resulting set of parameters and functions is called the force field, is crucial to the success of molecular mechanics calculations. A force field parameterized against a specific class of molecules, for instance proteins, would be expected to only have any relevance when describing other molecules of the same class.

Monday, February 25, 2008

Jupiter

Jupiter (pronounced /'d?u?p?t?/) is the fifth planet from the Sun and the largest planet within the solar system. It is two and a half times as enormous as all of the other planets in our solar system combined. Jupiter, next to Saturn, Uranus and Neptune, is classified as a gas giant. Together, these four planets are sometimes referred to as the Jovian planets; somewhere Jovian is the adjectival form of Jupiter.

The planet was known by astronomers of ancient times and was connected with the mythology and religious beliefs of many cultures. The Romans named the planet subsequent to the Roman god Jupiter. When view from Earth, Jupiter can arrive at an apparent magnitude of -2.8, creation it the third brightest object in the night sky after the Moon and Venus.

Tuesday, February 19, 2008

Strawberry

The strawberry (Fragaria) (plural strawberries) is a type of plants in the family Rosaceae and the fruit of these plants. There are more than 20 named types and a lot of hybrids and cultivars. The most frequent strawberries grown commercially are cultivars of the Garden strawberry. Strawberries have a taste that varies by cultivar, and range from quite sweet to slightly tartlet.

Monday, February 11, 2008

History museums

History museums cover the information of history and its meaning to the present and future. Some cover particular aspects of history or a particular locality; others are more general. Such museums contain a broad range of objects, including documents, artifact of all kinds, art, and archaeological substance. Antiquities museums think in more archaeological findings.
A common type of history museum is a major house. A historic house may be a building of special architectural interest, the birthplace or home of a famous person, or a house with an attractive history. Historic sites can also become museums, mostly those that mark public crimes, such as Tuol Sleng or Robben Island.

Another category of history museum is a living museum; a living museum is where people reorganize a time period to the fullest extent, including buildings, clothes and language. It is alike to historical rebuilding.

Monday, February 04, 2008

Climate

The climate is commonly measured to be the weather averaged over a long period of time, naturally 30 years. Somewhat more precisely, the concept of "climate" also includes the statistics of the weather - such as the degree of day-to-day or year-to-year difference expected. IPCC is called as Intergovernmental Panel on Climate Change.

Climate in a narrow sense is usually defined as the "average weather", or more meticulously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time range from months to thousands or millions of years. The traditional period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are the majority often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a numerical description, of the climate system.

Monday, January 28, 2008

Dye-transfer process

The dye transfer progression is a continuous-tone color photographic printing process, popularized by the Eastman Kodak Company in the 1940s. It is sometimes referred to by such general names as wash-off relief printing and dye imbibition’s transfer printing. The process involves making three matrices for each color, which absorb dye in quantity to the density of the relief. A color print is shaped, by transferring the dyed film matrices in physical contact onto a mordant dye receiver paper. Eastman Kodak Company congested making materials for this process in the mid 1990s. The dyes used in the process are very spectrally pure compare to normal coupler induced photographic dyes, with the immunity of the Kodak cyan. Also the dyes have exceptional light and dark fastness. The dye transfer process possesses the major color gamut and tonal scale than any other process, including inkjet. Another important characteristic of dye move is it allows the practitioner the highest degree of photographic control compare to any other photochemical color print process.

Monday, January 21, 2008

Debenture

In finance, a debenture is a long-term debt instrument used by governments and large companies to get funds. It is similar to a bond apart from the securitization conditions are different. A debenture is frequently unsecured in the sense that there are no liens or pledges on specific assets. It is however, secured by all property not otherwise pledged. In the case of insolvency debenture holders are considered general creditors.
The advantage of debentures to the issuer is they leave specific assets imaginative, and thereby leave them open for subsequent financing. Debentures are generally freely transferable by the debenture holder.

Wednesday, January 16, 2008

Cricket ball

Cricket balls are made from a core of cork, which is coated with tightly wound string, and covered by a leather case with a slightly raised sewn seam. The covering is constructed of four piece of leather shaped similar to the peel of a quartered orange, but one hemisphere is rotated by 90 degrees with respect to the other. The "equator" of the ball is stitch with string to form the seam, with a total of six rows of stitches. The remaining two join connecting with the leather pieces are left unstitched.For men's cricket, the ball must weigh between 5.5 and 5.75 ounces (155.9 and 163.0 g) and determine between 8 13/16 and 9 in (224 and 229 mm) in circumference. Balls used in women's and youth matches are a little smaller.