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Archive:Total parenteral nutrition

2009-03-14T00:24:23Z

129.2.170.36: Intermal link added for enteral feeding

[[Image:Tpn 3bag.jpg|thumb|Home TPN formula]]

'''Total [[parenteral]] nutrition''' (TPN), is the practice of feeding a person [[intravenous]]ly, bypassing the usual process of [[eating]] and [[digestion]]. The person receives nutritional formulas containing [[salt]]s, [[glucose]], [[amino acid]]s, [[lipid]]s and added [[vitamin]]s.

==General usage==

{{Unreferencedsection|date=October 2007}}

Total parenteral nutrition (TPN), also referred to as Parenteral nutrition (PN), is provided when the gastrointestinal tract is nonfunctional because of an interruption in its continuity or because its absorptive capacity is impaired (Kozier et al., 2004). It has been used for [[coma]]tose patients, although [[enteral feeding]] is usually preferable, and less prone to complications. Short-term TPN may be used if a person's digestive system has shut down (for instance by [[Peritonitis]]), and they are at a low enough weight to cause concerns about nutrition during an extended hospital stay. Long-term TPN is occasionally used to treat people suffering the extended consequences of an accident or surgery or digestive disorder. TPN has extended the life of children born with nonexistent or severely deformed guts. People have survived on parenteral nutrition for more than 35 years, living fully productive lives.

The preferred method of delivering TPN is with a medical [[infusion pump]]. A [[sterilization (microbiology)|sterile]] bag of nutrient solution, between 500 mL and 4 L is provided. The pump infuses a small amount (0.1 to 10 mL/hr) continuously in order to keep the vein open. Feeding schedules vary, but one common regimen ramps up the nutrition over one hour, levels off the rate for a few hours, and then ramps it down over a final hour, in order to simulate a normal metabolic response resembling meal time. This should be done over 12 to 14 hours rather than intermittently during the day.

Chronic TPN is performed through a central intravenous catheter, usually through the [[subclavian vein|subclavian]] or [[jugular vein]] with the tip of the catheter at the superior vena cava without entering the right atrium. Another common practice is to use a [[PICC line]], which originates in the arm, and extends to one of the central veins, such as the subclavian with the tip in the superior vena cava. In infants, sometimes the [[umbilical vein]] is used.

Battery-powered ambulatory infusion pumps can be used with chronic TPN patients. Usually the pump and a small (100 ml) bag of nutrient (to keep the vein open) are carried in a small bag around the waist or on the shoulder. Outpatient TPN practices are still being refined but have been used for years. Patients can receive the majority of their infusions while they sleep and instill heparin in their catheters when they are done to simulate a more "normal" life style off the pump.

Aside from their dependence on a pump, chronic TPN patients can live quite normal lives. A non-profit organization, the Oley Foundation, provides free information and programs to better the quality of life for TPN and tube fed patients.

In most US hospitals, [[clinical pharmacist]]s evaluate the patient's individual data and decide what TPN formula to use.

==Complications==

The most common complication of TPN use is bacterial infection, usually due to the increased infection risk from having an indwelling [[central venous catheter]]. In patients with frequent bacterial infections, fungal infections can also occur. [[Liver failure]], often related to [[Fatty liver]], may sometimes occur. This condition is generally due to excess in glucose provided in TPN solutions.

Two related complications of TPN are [[venous thrombosis]] and rarely [[priapism]]. Fat infusion during TPN is assumed to contribute to both.<ref>{{cite journal |author=Hébuterne X, Frere AM, Bayle J, Rampal P |title=Priapism in a patient treated with total parenteral nutrition |journal=JPEN J Parenter
Enteral Nutr |volume=16 |issue=2 |pages=171–4 |year=1992 |pmid=1556816 |doi=10.1177/0148607192016002171 |url=}}</ref>

Total parenteral nutrition increases the risk of acute [[cholecystitis]] due to complete unusage of gastrointestinal tract, which may result in bile stasis in the [[gallbladder]]. The risk of acute cholecystitis is increased accordingly.

A recent small-scale study at Children's Hospital Boston on the cause of liver failure suggests it may be due to a large difference in omega-6 to omega-3 ratio. When treated with [[Omegaven]], a different fatty acid infusion (which is approved for limited use in the U.S.), two patients were able to recover from their condition.<ref>{{cite journal |author=Gura KM, Duggan CP, Collier SB, ''et al'' |title=Reversal of parenteral nutrition-associated liver disease in two infants with short bowel syndrome using parenteral fish oil: implications for future management |journal=[[Pediatrics (journal)|Pediatrics]] |volume=118 |issue=1 |pages=e197–201 |year=2006 |month=July|pmid=16818533|doi=10.1542/peds.2005-2662 |url=http://pediatrics.aappublications.org/cgi/content/full/118/1/e197?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=parenteral+nutrition&searchid=1&FIRSTINDEX=0&volume=118&issue=1&resourcetype=HWCIT}}</ref>

==In critical and/or perioperative care==

Parenteral nutrition is indicated to prevent the adverse effects of malnutrition in patients who are unable to obtain adequate nutrients by oral or enteral routes. Other indications are short gut syndrome, high-output fistula, prolonged ileus, or bowel obstruction. However, the decision to initiate TPN needs to be made on an individual patient basis, as different patients will have differing abilities to tolerate starvation.<ref>[http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=3056&nbr=2282 American Gastroenterological Association medical position statement: parenteral nutrition]</ref>

The nutrient solution consists of [[water]] and electrolytes; [[glucose]], [[amino acid]]s, and lipids; essential [[vitamin]]s, minerals and trace elements are added or given separately. Previously lipid emulsions were given separately but it is becoming more common for a "three-in-one" solution of glucose, proteins, and lipids to be administered.<ref>{{cite journal |author=Didier ME, Fischer S, Maki DG |title=Total nutrient admixtures appear safer than lipid emulsion alone as regards microbial contamination:
growth properties of microbial pathogens at room temperature |journal=JPEN J Parenter Enteral Nutr |volume=22 |issue=5 |pages=291–6 |year=1998 |pmid=9739032
|doi=10.1177/0148607198022005291 |url=}}</ref><ref>{{cite journal |author=Rollins CJ, Elsberry VA, Pollack KA, Pollack PF, Udall JN |title=Three-in-one parenteral nutrition: a safe and economical method
of nutritional support for infants |journal=JPEN J Parenter Enteral Nutr |volume=14 |issue=3 |pages=290–4 |year=1990 |pmid=2112645 |doi=10.1177/0148607190014003290 |url=}}</ref>

'''Complications''' are either related to Catheter insertion, or Metabolic (including the Refeeding Syndrome). Catheter complications include pneumothorax, accidental arterial puncture, and catheter-related sepsis. The complication rate at the time of insertion should be less than 5%.<ref>{{cite journal |author=McGee DC, Gould MK |title=Preventing complications of central venous catheterization |journal=N. Engl. J. Med. |volume=348 |issue=12
|pages=1123–33 |year=2003 |month=March |pmid=12646670 |doi=10.1056/NEJMra011883 |url=http://content.nejm.org/cgi/pmidlookup?view=short&pmid=12646670&promo=ONFLNS19}}</ref> Catheter-related infections may be minimised by appropriate choice of catheter and insertion technique.<ref>{{cite journal |author=Horattas MC, Trupiano J, Hopkins S, Pasini D, Martino C, Murty A |title=Changing concepts in long-term central venous access: catheter
selection and cost savings |journal=Am J Infect Control |volume=29 |issue=1 |pages=32–40 |year=2001 |month=February |pmid=11172316 |doi=10.1067/mic.2001.111536
|url=}}</ref> Metabolic complications include the [[Refeeding]] Syndrome characterised by hypokalemia, hypophosphatemia and hypomagnesemia. Hyperglycemia is common at the start of therapy, but can be treated with insulin added to the TPN solution. Hypoglycaemia is likely to occur with abrupt cessation of TPN. Liver dysfunction can be limited to a reversible cholestatic jaundice and to fatty infiltration (demonstrated by elevated transaminases). Severe hepatic dysfunction is a rare complication.<ref>G. Edward Morgan, Jr., Maged S. Mikhail, Michael J. MurrayClinical Anesthesiology, 4th Edition</ref> Overall, patients receiving TPN have a higher rate of infectious complications. This can be related to hyperglycemia.<ref>McCowen K, Friel C, Sternberg J et al. Hypocaloric total parenteral nutrition: effectiveness in prevention of hyperglycemia and infectious complications--a randomised clinical trial. Crit Care Med 2000; 28: 3606-11</ref>

==See also==
* [[Intravenous drip]]

==References==
{{reflist|2}}



== External links ==
*[http://www.nutritioncare.org American Society for Parenteral and Enteral Nutrition]
*[http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a601166.html TPN Drug Information] from MedlinePlus NIH Database

[[Category:Nutrition]]
[[Category:Intensive care medicine]]
[[Category:Intravenous fluids]]

[[de:Parenterale Ernährung]]
[[es:Nutrición parenteral]]
[[nl:Parenterale voeding]]
[[ja:高カロリー輸液]]
[[pl:Żywienie pozajelitowe]]
[[pt:Nutrição parenteral]]

Software industry

2008-12-01T12:50:07Z

129.2.210.55:

{{globalize}}

The '''software industry''' includes businesses involved in the [[software development|development]], [[software maintenance|maintenance]] and [[software publisher|publication]] of [[computer software]] using any business model. The industry also includes software [[Service (economics)|service]]s, such as [[training]], [[software documentation|documentation]], and [[consultancy|consulting]].

The largest and most profitable of software companies are located in the [[United States]]. As of 2008, the client software industry is dominated by [[Microsoft]]{{Fact|date=March 2008}}. [[Software Magazine]]'s 500 list in 2005 shows the total amount of revenue brought in by software companies per locale, with the highest being [[California]] due to [[Silicon Valley]] and the number of [[Fortune 500]] software companies residing in that area. <ref>[http://www.softwaremag.com/SW500/index.cfm?StartRow=1&RowsPer=50&BusCat_Search=&PrimBus_Search=&PrimBusCat_Search=&RankSort=ASC&CompSort=&trk=n&id=5 Software Magazine 500] (2005)</ref>

== Overview ==
There are several types of businesses in the software industry. The largest and most profitable publish horizontal [[proprietary software]] such as [[Microsoft]], [[SAP]], [[Oracle]], and [[Adobe]]. Others develop vertical-market software intended for a particular sector or niche in the economy such as finance, health care, insurance, retail, automotive manufacturing, and so on. A great deal of specialized software is produced for various niches. Other companies do contract programming to develop unique software for one particular client company, or focus on configuring and customizing suites from large vendors such as SAP or Oracle. And a few companies publish or support [[open source software]].

Developing proprietary software involves [[software licensing]] and the need to protect the software from [[Software cracking|cracking]] and [[Software piracy|piracy]].

== History ==
The software industry started in the early 1960s when universities and businesses first began to use computers and to seek out programs to do certain computing tasks. Many of these programs were written in-house by full-time staff programmers. Some were distributed freely between users of a particular machine for no charge. But others were done on a commercial basis, and the very first standalone software firms started in the United States in 1959-1960.

The industry expanded greatly with the rise of the personal computer in the mid-1970s, which created a growing market for games, applications, and utilities. And gradually the concept that software should be bought and paid for took hold. One of the earliest proponents of this view was [[Bill Gates]], founder of [[Microsoft]].

In the early years of the 21st century, another successful business model has arisen for hosted software, called software as a service, or [[SaaS]]; this was at least the third time this model had been attempted. SaaS reduces the concerns about software piracy, since it can only be accessed through the Web, and by definition no client software is loaded onto the end user's PC.

== Size of the industry ==
[[Software Magazine]]s' ''Software 500 survey'' can be used to gauge the value of the commercial software industry. The ''Software 500 survey'' consists of data from the largest 500 public and private software companies, as ranked by [[Software Magazine]]. Total worldwide revenues in 2007 for companies in the ''Software 500'' list were $451.8 billion, up 14.7% from 2006, when total Software 500 revenue was $394 billion.<ref>[http://www.softwaremag.com/L.cfm?Doc=1175-10/2008 Software Magazine - 2008 Software 500: Innovation Alive and Well</ref>

== Open source software ==
The financial return on open source software comes from selling services, such as training and support, rather than the software itself.

Much of the Internet runs on open source software tools and utilities such as [[Linux]], [[Apache HTTP Server|Apache]], [[MySQL]], and [[PHP]], known as the LAMP stack for web servers. Using open source appeals to software developers for three main reasons: low or no cost, access to [[source code]] they can tailor themselves, and a shared community that ensures a generally robust code base, with quick fixes for any new issues that surface.

Despite doing much business in proprietary software, some companies like [[Sun Microsystems]] and [[IBM]] participate in developing free and open source software to deter from [[monopoly|monopolies]] and take a portion of [[market share]] for themselves. [[Netscape]]'s actions are an example of this, and thus [[Firefox]] has become more popular, stealing market share from Internet Explorer.<ref>[[Netscape_Navigator#Fall_of_Netscape]]</ref> But in general, it remains difficult to base a successful business on the open source model.

== See also ==
* [[Professional open-source| Professional Open Source Business Model]]
* [[Computer software]]
* [[Software development]]
* [[Software publisher]]
* [[Software engineering]]
* [[World's largest software companies]]
* [[China Software Industry Association]] (CSIA)

== References ==
<div class="references-small"><references/></div>

== External links ==
{{Wiktionary}}
* [http://www.siia.net/ Software and Information Industry Association website]
* [http://www.softwareceo.com/ SoftwareCEO] the largest online community of software executives in the world
* [http://www.softwaremag.com/ Software Magazine website]
* [http://www.siprofessionals.org/ Software Industry Professionals website]
* [http://www.sao.org/ Software Association of Oregon website]
* [http://software.computerdictionaries.org/ Software Terms] A collection of software dictionaries

[[Category:Industries]]
[[Category:Software industry|*]]

[[ar:صناعة البرمجيات]]
[[es:Industria del software]]
[[simple:Software company]]
[[sv:Programvaruföretag]]
[[th:ซอฟต์แวร์เชิงพาณิชย์]]

Stellar evolution

2008-05-12T20:55:49Z

129.2.175.80: /* Introduction */

[[Image:NGC6543.jpg|thumb|The [[w:Cat's Eye Nebula|Cat's Eye Nebula]], a [[w:planetary nebula|planetary nebula]] formed by the death of a star with about the same mass as the sun]]

==Introduction==

How do stars form, how do they burn for so long and how do they die? This lesson aims to explain the entire process of a star's evolution from formation to its sometimes violent death.

Stellar evolution can be described as the birth, life, and death of a star. A period that can last from ten billion to a few hundred billion years depending on its size. Our Sun is about 4.5 billions years old and should last us another six billion years, making our Sun an average star amongst the bounty and variety of stellar mass' in our galaxy, the Milkyway.
Throughout a star's life, the star fiercely consumes it hydrogen through the process of nuclear fusion in its core, creating new and heavier elements until the star has exhausted all of its fuel. The end of a star's life again depends on the star's size; for example, our sun will most likely become a red giant and then slowly shrink for another few million years and become a dark cinder called a brown dwarf. Yet other stars with much larger masses of about ten times that of our Sun's have an increased chance that they may burst and eject all of their stellar material into the surrounding space leaving behind a super-dense object called a neutron star.

Students should have a good grasp of classical physics and calculus.

Structure of the course:

*'''Initial Conditions'''
**Collapsing Gas Clouds
**The Virial Theorem
**Jeans Mass
**Kelvin-Helmholz Contraction

*'''Nuclear Fusion in Stars'''
**The proton-proton chain

Students will understand the following:
1.The stages of evolution a star goes through are determined by the size of the star.

==Materials required==

For this lesson, you will need:

Research materials about stars and the evolution of stars

==Lesson==
#Review what you have learned about stars so far. In the course of discussion, determine how much you know about star evolution.
#Do you fully understand the terms red giant, white dwarf, neutron star, supernova, and black hole? If not, become acquainted with the terms and understand how they relate to the evolution of stars of different sizes.
#Before continuing the activity, you should understand the following three facts:
##A star the size of our sun will burn steadily for 10 billion years, then expand to a red giant, and finally collapse into a white dwarf about the size of Earth.
##A star three or four times the sun’s mass will burn steadily for a shorter time, then expand into a red giant, and finally collapse, ending up as a neutron star—a super-dense star about the size of a large city.
##A star 50 times the sun’s mass will burn for an even shorter time and may blow up as a supernova before collapsing and eventually shrinking to infinity, becoming a black hole.
#Divide into three groups, each group should focus on one of the three types of stars just mentioned: a star the size of our sun, a star three or four times the sun’s mass, and a star 50 times the sun’s mass.
#Each student should use her or his prior knowledge and information from research to draw a carefully labeled set of diagrams illustrating the stages in the evolution of the type of star assigned to them.
#Display students’ diagrams below so that the class can use them to compare the stages of evolution of the three different types of stars.

Draw a set of diagrams for all three types of stars.

Example diagram:
[[w:Image:Sun Life.png]]

==Discussion Questions==

#Discuss why some scientists were uneasy about the idea of an expanding universe?
#Astronomer Wendy Freedman's observations of Cepheid variable stars in another galaxy indicated that the age of the universe is about eight-twelve billion years. Why did her discovery cause such a debate among astronomers? What elements of her discovery still lend themselves to argument?
#What do scientists learn by observing parts of the universe in other than the visible parts of the spectrum?
#What materials are believed to compose dark matter, and what can we learn about the universe by examining it?

==Evaluation==

Evaluations of the diagrams are as follows:

Three points: diagrams carefully prepared; labels clear and correct; diagrams accurately illustrate the star’s stages of evolution

Two points: diagrams adequately prepared; some labels unclear or incorrect; diagrams accurately illustrate the star’s stages of evolution

One point: diagrams carelessly prepared; labels unclear and/or incorrect; diagrams reflect some inaccurate information about the star’s stages of evolution

Students can contribute to the assessment by determining how many diagrams will be required to illustrate the stages of evolution for each type of star.

==Extra==
*Cepheid variables, supernovae, dark matter, cosmic background radiation, black holes, red shift.

==Readings==
*[[w:Astronomy]]
**[[w:Star]]
***[[w:Stellar evolution]]
etc...

[[Category:Astronomy]]
[[Category:Learning activities]]

Template:Max

2007-07-03T17:43:20Z

129.2.100.211:

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Archive:Fanboy

2006-10-09T03:29:04Z

129.2.213.93:

{{Otheruses3|Fanboys}}

'' '''Fanboy''' '' or '' '''fanboi''' '' is a term used to describe an individual (usually male, though the feminine version ''fangirl'' may be used for females) who is utterly devoted to a single fannish subject, or to a single point of view within that subject, often to the point where it is considered an [[obsession]].

==History of fanboys and the term==
The term originated in [[comic book]] circles, to describe someone who immersed himself in the fictional worlds of comics and the culture of comics fandom. The term is often used in a derogatory manner by other less obsessed fans. In the songs of the fannish [[parody]] [[musician]] [[Luke Ski]], many characters proudly consider themselves ''fanboys''. The term is most commonly associated with adolescent and teen males but can be applicable to any age or sex. Common subjects of reverence by fanboys are [[TV show]]s, [[film|movie]]s, [[music]], [[anime]], [[car]]s, [[video game console]]s, [[video games]], [[operating system]]s, [[MMORPG]]s, and [[software]] companies.

The stereotypical image of the fanboy is as an unkempt, socially awkward, young man who may be perceived as a loud mouthed [[pseudo-intellectual]]. A popular depiction of this stereotype is the [[Comic Book Guy]] on ''[[The Simpsons]]''.

The earliest use of the word "fanboy" has been dated to 1982, to the cover of the "Official Underground and Newave Comix Price Guide". On this cover page are sketched overweight, overzealous comic book collectors wearing T-shirts that state "Fanboys of America," and are describing the extreme measures they would go to, including moving to San Francisco to preserve their comics. Another early use is in a smart-alec editorial reply by "[[Ambush Bug]]" to a letter in his comic in [[1985]].

"Fanboys" remain loyal to their particular obsession, disregarding any factors that differ from their point of view. They are also typically hateful the opposing brand of their obession regardless of its merits or achievements.

==Subjects of reverence==
Some brands and products, which have fanboy supporters:
*The [[graphics processing unit|graphics processing units]] produced by [[ATI Technologies|ATI]] and [[NVIDIA|nVidia]]
*The [[computer]] [[microprocessor]] companies [[Advanced Micro Devices|AMD]] and [[Intel Corporation|Intel]]
*The [[automobile]] companies [[Ford Motor Company|Ford]], [[General Motors]], and [[DaimlerChrysler]]
*The [[cola]] products: [[Coca-Cola|Coke]], from the [[The_Coca-Cola_Company|The Coca-Cola Company]]; and [[Pepsi]], from [[PepsiCo]]
*The competing video game consoles: [[Xbox 360]], [[Wii]] and [[Playstation 3]] from [[Microsoft]], [[Nintendo]] and [[Sony]]
*The competing handheld video game consoles: [[PlayStation Portable]] from [[Sony]], and the [[Nintendo DS]]
*The competing [[DVD]] formats [[Blu-ray Disc|Blu-ray]] and [[HD DVD]]

==Trivia==
The word "fanboys" can be a [[mnemonic]] [[acronym]] for the [[Grammatical conjunction|coordinating conjunction]]s of the [[English language]]: "for", "and", "nor", "but", "or", "yet", and "so".

==Media==
===Comic Book===
*[[Sergio Aragonés]]' ''Fanboy''
*Doug Holverson's "Fanboy" (anthropomorphized rotary fan obsessed with comics, who uses his electrical plug for a hand). Dates from the prolific minicomic wave of the 1980s.

===Television===
*''[[The Simpsons]]'''s [[Comic Book Guy]] refers to himself as a fanboy.
*''[[Freakazoid!|Freakazoid]]'''s [[freakazoid!#Other_characters|Fan Boy]]

===Radio/Podcasts===
*[[Fanboy Radio]] - [http://fanboyradio.com]
*Drooling FanBoy - [http://droolingfanboy.com]
*ifanboy - [http://www.ifanboy.com]
*[[The Fanboy Smackdown Podcast]] - [http://www.fanboysmackdown.com]

===Webcomics===
*Fanboy Almanac (webcomic) - [http://fanboyalmanac.com Fanboy Almanac]
*[http://www.ngeb.net/fanboys Fanboys web comic]
*[http://www.fogclub.net Fanboy Otaku Gamers Club web comic]
*[http://www.fanboysonline.com Fanboys!! Beyond Geekdom!!! (webcomic)]
*[http://www.fanboys-online.com Fanboys-Online]

===Video Games===
*[http://www.dsfanboy.com DS Fanboy]
*[http://www.pspfanboy.com PSP Fanboy]
*[http://www.nintendowiifanboy.com Nintendo Wii Fanboy]
*[http://www.ps3fanboy.com Playstation 3 Fanboy]
*[http://www.xbox360fanboy.com Xbox 360 Fanboy]

==See also==
* [[Addiction]]
* [[Otaku]]
* [[Anorak (slang)|Anorak]]

== External links ==
* [http://www.urbandictionary.com/define.php?term=fanboy Urban dictionary: fanboy]
* [http://www.netjak.com/review.php/1013 Dissecting the Fanboy Mind] - A discussion of the fanboy behavior in regards to video games.

[[Category:Fandom]]
[[Category:Anime and manga terminology]]
[[de:Fanboy]]