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ARCHAEOLOGY


In archaeology, ''in situ'' refers to an artifact that has not been moved from its originial place of deposition. An artifact being ''in situ'' is critical to the interpretation of that artifact and, consequently, to the culture which formed it. Once an artifact's provenance has been recorded, the artifact can then be moved for conservation, further interpretation and display. An artifact that is not discovered ''in situ'' is considered out of context and will not provide an accurate picture of the associated culture. However, the out of context artifact can provide scientists with an example of types and locations of ''in situ'' artifacts yet to be discovered.


BIOLOGY


In Biology , ''in situ'' means to examine the phenomenon exactly in place where it occurs (without removing it in some special medium etc.). Usually means something intermediate between In Vivo and In Vitro . For example, examining a cell within a whole Organ Intact and under Perfusion may mean ''in situ'' investigation. This is not obviously in vivo experimenting because an animal is sacrificed, but it is not the same as working with the cell alone (which may be a perfect case of an in vitro experiment).

In Oncology , for a Carcinoma which is a cancer of an Epithelium , ''in situ'' means that malignant cells are present in the epithelium but has not invaded beyond the Basal Lamina into deeper tissues.

In Genetics , ''in situ'' can also mean ''in the chromosome''. For example, FISH can be done with chromosomes in cells or in a karyotype, such as with Spectral Karyotyping . In each case, we are observing the target sequence(s) where they are in the chromosome.


CHEMISTRY

In chemistry, there are numerous unstable molecules which must be synthesized ''in situ'' for use in various processes. Examples include the Corey-Chaykovsky Reagent and Adrenochrome .


EARTH AND ATMOSPHERIC SCIENCES


In Physical Geography and the Earth Science s, ''in situ'' typically describes natural material or processes prior to transport. For example, ''in situ'' is used in relation to the distinction between Weathering and Erosion , the difference being that erosion requires a transport medium (such as Wind , Ice , or Water ), whereas weathering occurs ''in situ''. Geochemical processes are also often described as occurring to material ''in situ''.

In the Atmospheric Sciences , in situ refers to measurements obtained through direct contact with the respective subject, such as a Radiosonde measuring a parcel of air or an Anemometer measuring wind, as opposed to Remote Sensing such as weather radar or satellites.


ENVIRONMENTAL ENGINEERING


''In situ'' can refer to where a clean up or Remediation of a Polluted site is performed using and simulating the natural processes in the Soil , contrary to Ex Situ where contaminated soil is Excavated and cleaned elsewhere, off site.


LITERATURE


In Literature ''in situ'' is used to describe a condition. The Rosetta Stone , for example, was originally erected in a courtyard, for public viewing. Most pictures of the famous stone are not ''"in-situ"'' pictures of it erected, as it would have been originally. The stone was uncovered as part of building material, within a wall. Its in situ condition today is that it is erected, vertically, on public display at the British Museum .


LINGUISTICS


In Linguistics , specifically Syntax an element may be said to be ''in situ'' if it is pronounced in the position where it is interpreted. For example, Questions in languages such as Chinese have ''in-situ'' wh-elements, with structures comprable to "John bought what?" while English wh-elements are not ''in-situ'': "What did John buy?"


LAW


In Legal context, ''in situ'' is often used for its literal meaning. For example, in Hong Kong , in situ land exchange involves the Government exchanges the original or expired Lease of a piece of land with a new Grant or re-grant with the same piece of land or a portion of that.


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