the cDNA library contains only complementary DNA molecules synthesized from mRNA molecules in a cell.
The advantage of cDNA library is that it contains only the coding region of a genome. To prepare a cDNA library, the first step is to isolate the total mRNA from the cell type of interest. Because eukaryotic mRNAs consist of a poly-A tail, they can easily be separated. Then the enzyme reverse transcriptase is used to synthesize a DNA strand complementary to each mRNA mlecule. After the single-stranded DNA molecules are converted into double-stranded DNA molecules by DNA polymerase, they are inserted into vectors and cloned.
The Johns Hopkins Center for Alternatives to Animal Testing (CAAT) works since 1981 to find new methods to replace the use of laboratory animals in experiments, reduce the number of animals tested, and refine necessary tests to eliminate pain and distress.
See also: http://caat.jhsph.edu/
Concerted Action on brownfield and Economic Regeneration Network.
The CABERNET network consists of 55 Members, including 8 Team Leaders and 4 Coordination Team members, originating from 21 countries across Europe.
The groups cover the different aspects of rehabilitation of brownfield sites. The network has been divided into 8 distinct stakeholder groups. A number of Stakeholder Groups also have invited non-contracted Associate Members.
CABERNET has a distinct multi-disciplinary flavour, consisting of members from a wide range of professional backgrounds including environmental science, engineering, spatial and urban planning, and political administration.
The Members, drawn from across the European Community and accession countries, represent interests that span the stakeholder spectrum.
calibration is he set of operations that establish, under specified conditions, the relationship between values indicated by a measuring instrument or measuring system, and the corresponding known values. The result of a calibration is sometimes expressed as a calibration factor, or as a series of calibration factors in the form of a calibration curve.
Calibration standard is a substance or reference material used to calibrate an instrument.
Calibration check standard is a standard independently prepared (different source, different analyst) from the calibration standards and run after the original calibration to verify the original calibration. There is usually at least one calibration check standard per batch.
calibration curve gives the relation between analyte concentration and analytical response. Normally at least 3-5 appropriately placed calibration standards are needed to adequately define the curve. The curve should incorporate a low standard not exceeding 10 times the detection limit. Analytical response, where appropriate, is zeroed using a reagent blank. Either a linear or
other curve fit, as appropriate, may be used. Standards and samples must have equivalent reagent backgrounds (e.g., solvent, acid content, etc.) at the point of analysis.
any one of a group of diseases that occur when cells in the body become abnormal and grow or multiply out of control.
Carcinogenity of chemical substances is confirmed by animal testing. In carcinogenicity tests the tumors grown on the effect of the substance are investigated.
the basic substance of nylon synthesis. Caprolactam is produced from phenol.
CARACAL is an expert group giving advice for the European Commission and ECHA (European Chemicals Agency) on questions related to REACH and CLP. It was founded as "European Commission Working Group on the Practical Preparations for REACH" in May 2004. As of September 2007, it was re-named into "REACH Competent Authorities (REACH CA)" and, as of March 2009, into "Competent Authorities for REACH and CLP (CARACAL)".
See also: http://ec.europa.eu/enterprise/sectors/chemicals/reach/caracal/index_en.htm
Concerted Action on risk Assessment for Contaminated Land
any member of a very abundant and widespread class of natural organic substances, compounds of carbon, hydrogen and oxygen, that includes the sugars, starch, and cellulose.
carbon capture and storage (CCS), also mentioned as carbon capture and sequestration, is a means of mitigating the contribution of fossil fuel emissions to global warming, based on capturing carbon dioxide (CO2) from large point sources such as fossil fuel power plants, and storing it in such a way that it does not enter the atmosphere.
Storage of the CO2 is envisaged either in deep geological formations, in deep ocean masses, or in the form of mineral carbonates. Geological formations are currently considered the most promising sequestration sites. Deep ocean storage has a risk of increased ocean acidification. Leakage of the underground storage places has also certain risk.
Although CO2 has been injected into geological formations for various purposes, the long term storage of CO2 is a relatively new concept. The first commercial example is Weyburn in 2000. Integrated pilot-scale CCS power plant was to begin operating in September 2008 in the eastern German power plant Schwarze Pumpe run by utility Vattenfall, in the hope of answering questions about technological feasibility and economic efficiency.
CCS applied to a modern conventional power plant could reduce CO2 emissions to the atmosphere by approximately 80-90% compared to a plant without CCS.
Capturing and compressing CO2 requires much energy and would increase the fuel needs of a coal-fired plant with CCS by 25%-40%. Estimates for 2025 say, that costs with CO2 sequestration will not be higher, than without. (Source: Wikipedia)
Carbon capture and storage has also been used to describe biological capture by plants and microorganisms and subsequent storage of atmospheric CO2, mainly in soil, and also in surface water sediments.
Biological sequestration involves the net removal of CO2 from the atmosphere by plants and micro-organisms and its storage in vegetative biomass or structura organic matter. such as humus. Terrestrial carbon sequestration means the storage in storage in vegetative biomass and in soils.
Terrestrial sequestration applies agro- and forestry-technologies as well as ecoengineering tools and offers many potential advantages:
- could sequester relatively large volumes of carbon at comparatively low cost
- protecting or improving soils, water resources, habitat, and biodiversity
- generate rural income
- promotes more sustainable agriculture and forestry practices.
the term used to describe the exchange of carbon (in various forms, e.g., as carbon dioxide) between the atmosphere, ocean, terrestrial biosphere, and geological deposits.
a colourless, non-poisonous gas (under a certain concentration) that is a normal part of the ambient air. CO2 or carbon dioxide is formed in combustion of fossil fuel or any carbon-containing organic materials. It is the endproduct of biological oxidation (energy production) by the respiration of aerobic or alternative respiration of anaerobic organisms. CO2 is employed by plants and other phototrophic organisms in the photosynthesis of carbohydrates.
arbon tetrachloride is produced by the high temperature chlorination of propylene or methane. It is used as a feedstock in the production of CFCs, HCFCs and HFCs, as a process agent in the production of chlorine, to extract nitrogen trichloride, and as a solvent to recover chlorine from tail gas. It has been phased out in dispersive uses since 1995 under the Montreal Protocol.
carbon management is the concept that the impact of burning fossil fuels on global warming might be minimized.
Carbon management have two main steps: carbon capturing or sequestration and carbon-storage. The practical solutions for minimizing emission and lowering CO2 content in the atmosphere may differ for point and diffuse sources.
Separation of emitted carbon (primarily carbon dioxide) maybe done by physico-chemical or biological methods. Physico-chemical methods are applied mainly for point sources (treatment of the emission of power plants and incinerators), the biological methods (immobilisation of CO2 by plants and microorganisms) for diffuse atmospheric CO2.
The storage may happen as deposites in geological formations or in biomass. The disposal into geological formations is carried out by geotechnologies. Storage in biomass is the result of agro- or ecotechnologies, and the carbon can be stored both in living or dead organic matter, or humus.
Terrestrial sequestration is based on biomass production (plant and microbial) an storage in the soil in form of humus.
carcinogen is a substance or a mixture of substances which induces cancer or increases its incidence (REACH).
Tghere are other definitions, such as the UNECE (2004) "The term carcinogen denotes a chemical substance or a mixture of chemical substances which induce cancer or increase its incidence".
An third alternate definition is that carcinogenic substances are ones that "induce tumors (benign or malignant), increase their incidence or malignancy, or shorten the time of tumor occurrence when they are inhaled, injected, dermally applied, or ingested".
Carcinogens are classified according to their mode of action as genotoxic or nongenotoxic carcinogens. Genotoxic carcinogens initiate carcinogenesis by direct interaction with DNA, resulting in DNA damage or chromosomal aberrations that can be detected by genotoxicity tests (OECD, 2006).
Nongenotoxic carcinogens are agents that, at least initially, directly internact with DNA. These indirect modifications to DNA structure, amount, or function may result in altered gene expression or signal transduction (OECD, 2006).
In animal studies, most potent mutagens are also found to be carcinogenic (Maurici, et al., 2005). Substances that induce tumors in animals are considered as presumed or suspected human carcinogens until convincing evidence to the contrary is presented (UNECE, 2004).
Maurici D, Aardema M, Corvi R, et al. (2005), “Carcinogenicity”. Alt Lab Anim Vol. 33 (Suppl 1): 177−182
carcinogenic effect has a substance or a mixture of substances which induces cancer or increases its incidence and/or malignancy or shorten the time to tumour occurrence. Causing cancer may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Carcinogenic chemicals have conventionally been divided into two categories according to the presumed mode of action. Non-genotoxic modes of action include epigenetic changes, i.e., effects that do not involve alterations in DNA but that may influence gene expression, altered cell-cell communication, or other factors involved in the carcinogenic process.
Cancer is a disorder of the cells, characterized by the lack of programmed cell death. Carcinogens induces the uncontrolled, malignant division pf cells, ultimately leading to the formation of tumors. Usually DNA damage leads to programmed cell death, but if the programmed cell death pathway is damaged, then the cell cannot prevent itself from becoming a cancer cell. The objective of investigating the carcinogenicity of chemicals is to identify potential human carcinogens, their modes of action, and their potency. Once a chemical has been identified as a carcinogen, there is a need to elucidate the underlying mode of action, i.e. whether the chemical is directly genotoxic or not. For genotoxic carcinogens it is assumed that, unless exception, there is no discernible threshold and that any level of exposure carries a risk. For non-genotoxic carcinogens, no-effect-thresholds are assumed to exist and to be discernable. Human studies are generally not available for making a distinction between the above mentioned modes of action; and a conclusion on this, in fact, depends on the outcome of mutagenicity testing and other mechanistic studies. In addition to this, animal studies may also inform on the underlying mode of carcinogenic action.
The cancer hazard and mode of action may also be highly dependent on exposure conditions such as the route of exposure. Therefore, all relevant effect data and information on human exposure conditions are evaluated.
carotene is an orange photosynthetic pigment in plants. Carotenes are responsible for the orange colour of the carrot for which it is named, and many other fruits and vegetables. Some type of microorganisms also synthetize carotenes.
In humans β-carotene can be stored in the liver and body fat and converted to retinal as needed, thus making it a form of vitamine-A for humans and some other mammals. The carotenes α-carotene and γ-carotene, due to their single retinyl group, also have some vitamin A activity (though less than β-carotene), but all other carotenoids, including lycopene, have no beta-ring and thus no vitamin A activity.
Carotenes are natural antioxidants and such thay are used for dietary supplements or food and cosmetics preservatives to prevent oxidation.
a substance which aids or promotes a chemical reaction without forming part of the final product. It enables the reaction to take place faster, remains unchanged at the end of the reaction and can provide control by increasing desirable reactions and decreasing undesirable reactions.
Biological catalysts are enzymes, which work in the living organisms, anabling reactions take place on low temperature and pressure. They accept specific substrates and catalyse specific reactions.
A catalytic converter in our casr is a device used to reduce the toxicity of emissions from an internal combustion engine. Catalytic converters are also used on generator sets, forklifts, mining equipment, trucks, buses, trains, airplanes and other engine-equipped machines. A catalytic converter provides an environment for a chemical reaction wherein toxic combustion by-products, such as NOx are converted to less-toxic substances, e.g. N2.
it is also called simply caustic or lye, its chemical formula is NaOH. originally ot was produced from soda (Na2CO3), today it is the principal co-product in chlorine manufacture. Sold as a household chemical for unblocking drains and used industrially in the manufacture of rayon, pulp and paper, aluminium, soaps and detergents, textiles and vegetable oils.
Central and Eastern European Countries.
CEFIC (European Chemical Industry Council) is the Brussels-based organization representing the European chemical industry. Since its creation in 1972, Cefic has grown to become one of the largest and most efficient advocacy network amongst the industry trade organizations in Europe and in the world, representing 29 000 companies that produce about 30% of the world chemicals and employ about 1.3 million people, 22 national chemical federations and 6 associated federations across Europe. Took part in over 60 Strategy Implementation Groups and Issue Teams dealing with the industry's strategic concerns such as REACH, energy, environment, international trade, research & innovation and many others. More than 4000 industry experts from companies and federations participate in the Cefic groups. CEFIC has Close cooperation with the US, Japan and other major chemical countries through ICCA and many federations and trade unions.
The European Policy Centre comprises 7 programmes, backed up by the two corporate Communications and Advocacy functions:
* Product Stewardship
* Industrial Policy
* Energy, HSE and Logistics
* Build Trust
* Research and Innovation
* Legislation and Advocacy
* Business Development and Special Projects
The Services Unit addresses both in-house support services and member services:
* Support services
There are four Industry Sectors :
* Fine, Specialty and Consumer Chemicals (FSCC)
* Halogens/Euro Chlor
Celeron is a brand name given by Intel Corp. to a number of different x86 computer microprocessor models targeted at budget personal computers.
cells from living organisms, e.g. from Chinese hamster or human, cultivated in artificial medium under constant environmental conditions.
Permanent cultures are maintained for years, cells often transformed or from cancer biopsis, used for in vitro biotests.
Primary cells are isolated from an organism, e.g. primary hepatocytes (liver cells).
Cultured cells can be used in biotests in vitro and in vivo and substitute laboratory animals in the testing of chemicals.
the International System of Units is called "SI" and is the Metric Measurement used in America. 1 centimeter is one hundredth from a meter (0.01 m). There are exactly 100 cm (centimeters) in the Base Unit meter. The conversion is shown in the following table:
|0.032 808 40
|0.393 700 8
|0.010 936 13
|0.061 023 744
|0.001 076 39
|0.155 000 31
|0.000 119 599
region of a chromosome with which spindle fibers are associated during cell division, allowing orderly movement of daughter chromosomes to the poles of the daughter cells.
Comprehensive Environmental Response, Compensation and Liability Act. Its common name is Superfund. It is a USA act of 1980 (CERCLA). This federal law was designed to clean up sites contaminated with hazardous substances. Superfund created the Agency for Toxic Substances and Disease Registry (ATSDR), and it provides broad federal authority to clean up releases or threatened releases of hazardous substances that may endanger human health or the environment. The law authorized the Environmental Protection Agency (EPA) to identify parties responsible for contamination of sites and compel the parties to clean up the sites. Where responsible parties cannot be found, the Agency is authorized to clean up sites itself, using a special trust fund.
Two main actions of Superfund:
1. Removal action: these are typically short-term response actions, where actions may be taken to address releases or threatened releases requiring prompt response. Removal actions are classified as: (1) emergency; (2) time-critical; and (3) non-time critical. Removal responses are generally used to address localized risks such as abandoned drums containing hazardous substances, contaminated surface soils posing acute risks to human health or the environment, etc.
2. Remedial actions: these are usually more long-term response actions than a removal action. Remedial actions permanently and significantly reduce the risks associated with releases or threats of releases of hazardous substances that are serious but lack the time-criticality of a removal action, and include such measures as preventing the migration of pollutants and neutralization of toxic substances. These actions can be conducted only at sites listed on the EPA National Priorities List (NPL), in the United States and territories.
Certified Reference Material (CRM)is a reference material having one or more property values that are certified by a technically valid procedure, accompanied by or traceable to a certificate or other documentation that is issued by a certifying authority.
an experimental exposure of a previously treated subject to a test substance following an induction period, to determine if the subject reacts in a hypersensitive manner.
a diagram that illustrates information in the form of a table, graph, or picture.
Chemical Abstracts Service maintains the most comprehensive list of chemical substances. Each substance registered in the CAS Registry is assigned a CAS Registry Number. The CAS Registry Number (commonly referred to as CAS number) is widely used as a unique identifier of chemical substances. (Source: REACH Glossary)