IdeaWazaWiki - User contributions [en]

Immunology basics

2009-03-07T00:20:45Z

58.165.251.117: /* Histological examination of the immune system */

'''Immunology''' is a broad branch of [[biomedical science|biomedical]] [[science]] that covers the study of all aspects of the [[immune system]] in all [[organism]]s. It deals with, among other things, the [[physiology|physiological]] functioning of the immune system in states of both health and disease; malfunctions of the immune system in immunological disorders ([[autoimmune diseases]], [[hypersensitivity|hypersensitivities]], [[immune deficiency]], [[transplant rejection]]); the physical, chemical and physiological characteristics of the components of the immune system [[in vitro]], [[in situ]], and [[in vivo]]. Immunology has applications in several disciplines of science, and as such is further divided.

Immunology is that branch of biomedical science,which deals with the study of normal and malfunctions of immune system in all organisms.

==Histological examination of the immune system==
Even before the concept of [[immunity (medical)|immunity]] (from ''immunis'', Latin for "exempt") was developed, numerous early physicians characterized organs that would later prove to be part of the immune system. The key primary lymphoid organs of the immune system are [[thymus]] and [[bone marrow]], and secondary lymphatic tissues such as [[spleen]], [[tonsil]]s, [[lymphatic system|lymph vessels]], [[lymph node]]s, [[adenoid]]s, and [[skin]]. When health conditions warrant, immune system organs including the thymus, spleen, portions of bone marrow, lymph nodes and secondary lymphatic tissues can be [[surgery|surgically]] excised for examination while patients are still alive.

Many components of the immune system are actually [[cell (biology)|cell]]ular in nature and not associated with any specific organ but rather are embedded or circulating in various [[tissue (anatomy)|tissues]] located throughout the body.

yo yo yo yo dig dog this part of the immune system dig dog dooood

==Classical immunology==

Classical immunology ties in with the fields of [[epidemiology]] and [[medicine]]. It studies the relationship between the body systems, [[pathogen]]s, and immunity. The earliest written mention of immunity can be traced back to the [[Pandemic|plague]] of [[Athens]] in 430 BCE. [[Thucydides]] noted that people who had recovered from a previous bout of the disease could [[nurse]] the sick without contracting the illness a second time. Many other ancient societies have references to this phenomenon, but it was not until the 19th and 20th centuries before the concept developed into scientific theory.

The study of the molecular and cellular components that comprise the immune system, including their function and interaction, is the central science of immunology. The immune system has been divided into a more primitive [[innate immunity|innate immune system]], and [[adaptive immunity|acquired or adaptive immune system]] of vertebrates, the latter of which is further divided into [[humoral immunity|humoral]] and [[cell-mediated immunity|cellular components]].

The humoral (antibody) response is defined as the interaction between [[antibody|antibodies]] and [[antigen]]s. Antibodies are specific proteins released from a certain class of immune cells (B lymphocytes). Antigens are defined as anything that elicits generation of antibodies, hence they are '''Anti'''body '''Gen'''erators. Immunology itself rests on an understanding of the properties of these two biological entities. However, equally important is the cellular response, which can not only kill infected cells in its own right, but is also crucial in controlling the antibody response. Put simply, both systems are highly interdependent.

In the 21st century, immunology has broadened its horizons with much research being performed in the more specialized niches of immunology. This includes the immunological function of cells, organs and systems not normally associated with the immune system, as well as the function of the immune system outside classical models of immunity.

==Clinical immunology== 
Clinical immunology is the study of [[disease]]s caused by disorders of the immune system (failure, aberrant action, and malignant growth of the cellular elements of the system). It also involves diseases of other systems, where immune reactions play a part in the pathology and clinical features.

The diseases caused by disorders of the immune system fall into two broad categories: [[immunodeficiency]], in which parts of the immune system fail to provide an adequate response (examples include [[chronic granulomatous disease]]), and [[autoimmunity]], in which the immune system attacks its own host's body (examples include [[systemic lupus erythematosus]], [[rheumatoid arthritis]], [[Hashimoto's disease]] and [[myasthenia gravis]]). Other immune system disorders include different [[hypersensitivity|hypersensitivities]], in which the system responds inappropriately to harmless compounds ([[asthma]] and other [[allergy|allergies]]) or responds too intensely.

The most well-known disease that affects the immune system itself is [[Acquired Immunodeficiency Syndrome|AIDS]], caused by [[HIV]]. AIDS is an immunodeficiency characterized by the lack of CD4+ ("helper") [[T cells]] and [[macrophages]], which are destroyed by HIV.

Clinical immunologists also study ways to prevent [[transplant rejection]], in which the immune system attempts to destroy [[allograft]]s or [[xenograft]]s.

==Immunotherapy==
:''See main article [[Immunotherapy]]''

The use of immune system components to treat a disease or disorder is known as immunotherapy. Immunotherapy is most commonly used in the context of the treatment of [[cancer]]s together with [[chemotherapy]] ([[Medication|drug]]s) and [[radiotherapy]] ([[electromagnetic radiation|radiation]]). However, immunotherapy is also often used in the immunosuppressed (such as [[HIV]] patients) and people suffering from other immune deficiencies or autoimmune diseases.

==Diagnostic immunology==
:''See main article [[Diagnostic immunology]]''
The specificity of the bond between antibody and antigen has made it an excellent tool in the detection of substances in a variety of diagnostic techniques. Antibodies specific for a desired [[antigen]] can be conjugated with a radiolabel, fluorescent label, or color-forming enzyme and are used as a "probe" to detect it.

==Evolutionary immunology==
Study of the immune system in extant and [[extinction|extinct]] species is capable of giving us a key understanding of the [[evolution]] of species and the immune system.

A development of complexity of the immune system can be seen from simple phagocytotic protection of single celled organisms, to circulating antimicrobial peptides in insects to lymphoid organs in vertebrates. Of course, like much of evolutionary observation, these physical properties are often seen from the [[anthropocentric]] aspect. It should be recognized that every organism living today has an immune system absolutely capable of protecting it from most forms of harm; those organisms that did not adapt their immune systems to external threats are no longer around to be observed.

[[Insect]]s and other [[arthropod]]s, while not possessing true adaptive immunity, show highly evolved systems of innate immunity, and are additionally protected from external injury (and exposure to pathogens) by their [[chitin]]ous shells.

==See also==
* [[Autoimmunity]]
* [[List of immunologists]]
* [[History of immunology]]
* [[Serology]]
* [[Immunodeficiency]]
* [[Medical technologist]]
* [[Osteoimmunology]]

== References ==
* [http://en.wikibooks.org/wiki/Immunology Wikibooks Immunology Textbook]
* Goldsby RA, Kindt TK, Osborne BA and Kuby J (2003) '''Immunology''', 5th Edition, W.H. Freeman and Company, New York, New York, ISBN 0-7167-4947-5

== External links ==
{{WVD}}
* [http://www.dayofimmunology.org/ April the 29th - the annual Day of Immunology]
* [[Annual Review of Immunology]] ([http://arjournals.annualreviews.org/loi/immunol journal home])
* [http://www.biomedcentral.com/bmcimmunol/ BMC: Immunology]- [[BioMed Central]]:Immunology is an [[open access journal]] publishing original peer-reviewed research articles.
* [http://www.fleming.gr Biomedical Sciences Research Center "Alexander Fleming" Institute of Immunology]
* [http://www.brt-labs.com/ BRT-Burleson Research Technologies] Tests the effects of pharmaceuticals in the developmental stage on the immune system.
* [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=imm.TOC&depth=2 Janeway's Immunobiology textbook] Searchable free online version at the [[National Center for Biotechnology Information]]
* [http://www.mugen-noe.org/ MUGEN NoE] murine models for immunological disease
* [[Nature Reviews Immunology]] ([http://www.nature.com/nri/index.html journal home])
* [http://www.immport.org The Immunology Database and Analysis Portal] - an NIAID-funded database resource of reference and experiment data covering the entire immunology domain
* [http://medweb2.unige.ch/immunologie/ Transplantation Immunology] Interesting web site made by the faculty of medicine of the University of Geneva dealing with the immunological issues linked with the transplantation of materials genetically different between donor and recipient (hematopoietical stem cells, organs or the transfusion of blood).
* [http://media.med.sc.edu/microbiology2007/ Online lectures in immunology] University of South Carolina
* [http://www.aaaai.org/ American Academy of Allergy, Asthma & Immunology] Medical specialty organization

{{Medicine}}
{{Immune system}}
[[Category:Immunology| ]]
[[Category:Subjects taught in medical school]]

{{Link FA|ca}}
{{Link FA|de}}

[[af:Immunologie]]
[[ar:علم المناعة]]
[[bs:Imunologija i imunohematologija]]
[[bg:Имунология]]
[[ca:Immunologia]]
[[cs:Imunologie]]
[[da:Immunologi]]
[[de:Immunologie]]
[[et:Immunoloogia]]
[[es:Inmunología]]
[[eo:Imunologio]]
[[eu:Immunologia]]
[[fa:ایمنی‌شناسی]]
[[fr:Immunologie]]
[[gl:Inmunoloxía]]
[[ko:면역학]]
[[hr:Imunologija]]
[[id:Imunologi]]
[[it:Immunologia]]
[[he:אימונולוגיה]]
[[lb:Immunologie]]
[[lt:Imunologija]]
[[hu:Immunológia]]
[[ms:Immunologi]]
[[nl:Immunologie]]
[[ja:免疫学]]
[[no:Immunologi]]
[[pl:Immunologia]]
[[pt:Imunologia]]
[[ro:Imunologie]]
[[ru:Иммунология]]
[[sq:Imunologjia]]
[[simple:Immunology]]
[[sk:Imunológia]]
[[sl:Imunologija]]
[[sr:Имунологија]]
[[sh:Imunologija]]
[[fi:Immunologia]]
[[sv:Immunologi]]
[[th:วิทยาภูมิคุ้มกัน]]
[[vi:Miễn dịch học]]
[[tr:İmmünoloji]]
[[uk:Імунологія]]
[[ur:مناعیات]]
[[zh:免疫学]]

Archive:Basic coastal geography

2007-05-16T08:31:46Z

58.165.200.194: /* Weathering Processes */

'''Coastal geography''' is the study of the dynamic interface between the ocean and the land, incorporating both the [[physical geography]](i.e coastal geomorphology, geology and oceanography) and the [[human geography]](sociology and history) of the coast. It involves an understanding of coastal weathering processes, particularly wave action, sediment movement and weather, and also the ways in which humans interact with the coast.

==Coastal processes==

===Wave action and longshore drift===
[[Image:Portcampbellcliffs.jpg|right|thumb|300px|The cliffs, rocky outcrops and powerful waves indicate this coastline in Port Campbell in southern Australia is a high energy shoreline.]]
The waves of different strengths that constantly hit against the shoreline are the primary movers and shapers of the coastline. Despite the simplicity of this process, the differences between waves and the rocks they hit result in hugely varying shapes.

The effect that waves have depends on their strength. Strong, also called destructive waves occur on high energy beaches and are typical of Winter. They reduce the quantity of sediment present on the beach by carrying it out to bars under the sea. Constructive, weak waves are typical of low energy beaches and occur most during summer. They do the opposite to destructive waves and increase the size of the beach by piling sediment up onto the berm.

One of the most important transport mechanisms results from [[wave refraction]]. Since waves rarely break onto a shore at right angles, the upward movement of water onto the [[beach]] (swash) occurs at an oblique angle. However, the return of water (backwash) is at right angles to the beach, resulting in the net movement of beach material laterally. This movement is known as beach drift (Figure 3). The endless cycle of swash and backwash and resulting beach drift can be observed on all beaches.

[[Image:RhossiliBeach.jpg|left|250px|thumb|The wide expanse of sand and low waves, even though a storm is blowing onshore, indicate that this coastline at Rhossili in Wales is a low energy shoreline.]]Probably the most important effect is [[longshore drift]] (LSD), the process by which sediment is continuously moved along beaches by wave action. LSD occurs because waves hit the shore at an angle, pick up sediment (sand) on the shore and carry it down the beach at an angle (this is called swash). Due to gravity, the water then falls back perpendicular to the beach, dropping its sediment as it loses energy (this is called backwash). The sediment is then picked up by the next wave and pushed slightly further down the beach, resulting in a continual movement of sediment in one direction. This is the reason why long strips of coast are covered in sediment, not just the areas around river mouths, which are the main sources of beach sediment. LSD is reliant on a constant supply of sediment from rivers and if sediment supply is stopped or sediment falls into a submarine canals at any point along a beach, this can lead to bare beaches further along the shore.

LSD helps create many landforms including [[barriers]], bay beaches and [[Spit (landform)|spits]]. In general LSD action serves to straighten the coast because the creation of barriers cuts off [[Headlands and bays|bays]] from the sea while sediment usually builds up in bays because the waves there are weaker (due to wave refraction), while sediment is carried away from the exposed [[Headlands and bays|headlands]]. The lack of sediment on headlands removes the protection from waves them and makes them more vulnerable to weathering while the gathering of sediment in bays (where longshore drift is unable to remove it) protects the bays from further erosion and makes them pleasant [[recreational beaches]].

{{seealso|Beach evolution}}

===Atmospheric processes===

*Onshore winds blowing "up" the beach, pick up sand and moves it up the beach to form [[sand dunes]].
*Rain hits the shore and erodes rocks and carries weathered material to the shoreline to form beaches.
*Warm weather can encourage chemical and biological processes to occur. In tropical areas some plants and animals protect stones from weathering, while others actually eat away at the rocks.
*Temperatures that vary from below to above freezing point result in [[Weathering#Freeze-thaw|freeze-thaw]] weathering, while weather more than a few degrees below freezing point creates sea ice.

===Biological processes===
In tropical regions in particular, plants and animals not only affect the weathering of rocks but are a source of sediment themselves. The shells and skeletons of many organisms are of calcium carbonate and when this is broken down it forms sediment, [[limestone]] and [[clay]].

===Physical processes===
The main Physical Weathering process on beaches is [[Weathering#Salt-crystal growth|salt-crystal growth]]. Wind carries salt spray onto rocks, where it is absorbed into small pores and cracks within the rocks. There the water evaporates and the salt crystallises, creating pressure and often breaking down the rock.
In some beaches calcium carbonate is able to bind together other sediments to form [[beachrock]] and in warmer areas [[dunerock]].

===Sea level changes===
Because the sea level on earth regularly rises and falls due to climatic changes. During cold periods more of the Earth’s water is stored as ice in glaciers while during warm periods it is released and sea levels rise to cover more land. Sea levels are currently quite high, while just 18,000 years ago during the [[Pleistocene]] ice age they were quite low. [[Global warming]] may result in further rises in the future, which presents a risk to coastal cities as most would be flooded by only small rises. As sea levels rise [[fjords]] and [[rias]] form. Fjords are flooded [[glacial valleys]] and rias are flooded river valleys. Fjords typically have steep rocky sides, while rias have dendritic drainage patterns typical of drainage zones.
As [[tectonic plates]] move about the Earth they can rise and fall due to changing pressures and the presence of glaciers. If a beach is moving upwards relative to other plates this is known as isostatic change and [[raised beaches]] can be formed.
{{seealso|Beach evolution}}

==Coastal landforms==

===Spits===
[[image:Chesil_and_fortuneswell.JPG|thumb|220px|[[Chesil Beach]], an excellent example of a [[tombolo]] in [[Dorset]], [[United Kingdom]].]]
If the coast suddenly changes direction, especially around an estuary, spits are likely to form. LSD pushes sediment along the beach but when it reaches a turn as in the diagram, the LSD does not always easily turn with it, especially near an estuary where the outward flow from a river may push sediment away from the coast. The area may be also be shielded from wave action, preventing much LSD. On the side of the headland receiving weaker waves, shingle and other large sediments will build up under the water where waves are not strong enough to move them along. This provides a good place for smaller sediments to build up to sea level. The sediment, after passing the headland will accumulate on the other side and not continue down the beach, sheltered both by the headland and the shingle.

Slowly over time sediment simply builds on this area, extending the spit outwards, forming a barrier of sand. Once in a while, the wind direction will change and come from the other direction. During this period the sediment will be pushed along in the other direction. The spit will start to grow backwards, forming a 'hook'. After this time the spit will grow again in the original direction. Eventually the spit will not be able to grow any further because it is no longer sufficiently sheltered from erosion by waves, or because the estuary current prevents sediment resting. Usually in the salty but calm waters behind the spit there will form a salt marshland. Spits often form around the breakwater of artificial harbours requiring dredging.

Occasionally, if there is no estuary then it is possible for the spit to grow across to the other side of the bay and form what is called a bar, or barrier. Barriers come in several varieties, but all form in a manner similar to spits. They usually enclose a bay to form a lagoon. They can join two headlands or join a headland to the mainland. When an island is joined to the mainland with a bar or barrier it is known as a tombolo. This usually occurs due to wave refraction, but can also be caused by isostatic change, a change in the level of the land (e.g. [[Chesil Beach]]). An example of this is along the Holderness coastline.

==See also==
*[[Coastal erosion]]
*[[Weathering]]
*[[Beach evolution]]

==Sources==

Codrington, Stephen. ''Planet Geography 3rd Edition'' (02-Dec-2006) Chapter 8 [http://www.planetgeography.com]

{{Physical geography topics}}

[[Category:Coastal geography]]
[[Category:Physical geography]]

Archive:Philip Zepter

2007-03-08T08:56:22Z

58.165.126.167: rv

'''Philip Zepter''' is a Serbian [[entrepreneur]] and the richest [[Serb]]s in the world with an estimated net worth of [[US dollar|$]]4 billion according to Polish magazine ''[[Wprost]]''.

Born '''Milan Janković''' in [[Bosanska Dubica]], [[Federal People's Republic of Yugoslavia]] in [[1950]], he is the graduate of [[University of Belgrade]]'s Faculty of Economy.

He later founded [[Zepter International]], which has over time become a succesful [[conglomerate (company)|conglomerate]] focusing, among other things, on production and sale of exclusive high-quality consumer products.

Zepter currently resides in [[Monte Carlo]].

{{Serbia-bio-stub}}
[[Category:Serbian people|Zepter, Philip]]
[[Category:Billionaires|Zepter, Philip]]