Species selection

Theoretically, any species could be used for acute toxicity tests, however, it is important that there be a sufficient body of backgroimd information on the species to be able to estimate the hazard of a chemical which is being tested relative to other materials. This would be true unless the species selected was a potential target for harm in the use of the chemical where a direct correlation 

A question remains about the minimum number of species that are necessary to adequately represent aquatic taxa for purposes of EQS derivation. There is no consensus among the authors about this minimum data requirement. 

The known effects of drugs from a variety of pharmacologic/therapeutic classes on the respiratory system and worldwide regulatory requirements support the need for conducting respiratory function evaluations in 

McNeill, R.S., Effect of a p-adrenergic blocking agent, propranolol, on asthmatics, Lancet, 1964, Nov., 21 1101-1102. 

Borison, H.L., Central nervous system depressants control-systems approach to respiratory depression, Pharmacol. Ther. B., 1977,3 211-226. 

Natural history of drug-induced pneumonitis. In Drug Induced Disorders, Volume 3 Treatment Induced Respiratory Disorders (Akoun, G.M., and White, J.P., eds.). New York Elsevier Scientific Publishers B.V., 1989, pp. 3-9. 

Dorato, M.A., Toxicological evaluation of intranasal peptide and protein drugs. Drugs and the Pharma. Sci, 1994, 62 345-381. 

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Climate and Environmental Factors. The biomass species selected for energy appHcations and the climate must be compatible to faciUtate operation of fuel farms. The three primary climatic parameters that have the most influence on the productivity of an iadigenous or transplanted species are iasolation, rainfall, and temperature. Natural fluctuations ia these factors remove them from human control, but the information compiled over the years ia meteorological records and from agricultural practice suppHes a valuable data bank from which to develop biomass energy appHcations. Ambient carbon dioxide concentration and the availabiHty of nutrients are also important factors ia biomass production. 

To conclude, the introduction of species-selective membranes into the simulation box results in the osmotic equilibrium between a part of the system containing the products of association and a part in which only a one-component Lennard-Jones fluid is present. The density of the fluid in the nonreactive part of the system is lower than in the reactive part, at osmotic equilibrium. This makes the calculations of the chemical potential efficient. The quahty of the results is similar to those from the grand canonical Monte Carlo simulation. The method is neither restricted to dimerization nor to spherically symmetric associative interactions. Even in the presence of higher-order complexes in large amounts, the proposed approach remains successful. 

Test name Ref. Usual solution composition Test procedure Quantitative measure Potential range (V vs. S.H.E.) Species selectively attacked... 

Tables 2.6 and 2.7 give examples of the modes of action of pollutants in animals and in plants/fungi, respectively. It is noteworthy that many of the chemicals represented are pesticides. Pesticides are designed to be toxic to target species. On the other hand, manufacturers seek to minimize toxicity to humans, beneficial organisms and, more generally, nontarget species. Selective toxicity is an important issue. Regardful of the potential risks associated with the release of bioactive compounds into the environment, regulatory authorities usually require evidence of the mode of toxic action before pesticides can be marketed. Other industrial chemicals are not subject to such strict regulatory requirements, and their mode of action is frequently unknown.

C19-0119. For each of the following pairs of species, select the one that is the better oxidizing agent under standard conditions (see Appendix F) (a) in acidic solution, Cr2 or Mn04 (b) in basic solution, O2 or N03 and(c) or Sn +. 

Tam et al. [37-47] developed an impressive generalized method for the determination of ionization constants and molar absorptivity curves of individual species, using diode-array UV spectrophotometry, coupled to an automated pH titrator. Species selection was effected by target factor analysis. Multiprotic compounds with overlapping pK s have been investigated binary mixtures of ionizable compounds have been considered assessment of inicroconstants have been reported. 

Trace-elemental analysis with species selectivity... 

Two types of OPIDN have been described in animals (Abou-Donia and Lapadula 1990). Type I is produced by compounds with a pentavalent phosphorus (like TOCP), and Type II is produced by compounds with a trivalent phosphorus. Characteristics used to differentiate between the types of OPIDN include species selectivity, age sensitivity, length of latent period, and morphology of neuropathologic lesions. Thus, at doses that did not produce death due to acetylcholinesterase inhibition, TOCP (a Type I compound) produced lesions in the spinal cord of rats without producing ataxia. In contrast, triphenyl phosphite (a Type II compound) produced delayed (1 week) ataxia in the rat and a distribution of spinal cord lesions distinct from those produced by TOCP (Abou-Donia and Lapadula 1990). 

David Hull Another example would be species selection, for upward versus downward. Are there characteristics of whole species which influence the behaviour of individual organisms, rather than the other way around (Audible No from someone). Yeah. There s a lot of people who say there is no species selection. This is an example of where the debate is. 

Wong reported that stoichiometric amounts of copper(I) chloride alone can promote the intramolecular Stille coupling (equation 138)243. In fact, copper(I)-mediated reaction was cleaner and faster compared with that catalysed by Pd(0) species. Selected examples of intermolecular Stille coupling reactions leading to dienes (Table 25)236a,242b 244, polyenes (Table 26)245 and macrocyclizations (Table 27)246 are given in the respective tables. 

This area was the most profusely studied in the AQUATERRA project in terms of biological effects in fish populations. Barbel and bleak were the sentinel species selected in this area and an array of histological and biochemical tests were used to monitor the impact due to three major sources of pollution mercury and OCs at Monzon (with a comparison in one of the papers with Flix) and PBDEs in Barbastro [1—4, 37]. Mercury pollution was directly correlated to an increase of MTprotein in the liver of barbel captured downstream Monzon when compared to samples captured upstream (Fig. 3a). However, mRNA quantitative analyses failed to show any differences between downstream and upstream Monzon, neither correlated with MT protein levels. Further studies showed that MT mRNA in liver is a rather weak marker for chronic metal pollution in liver (see below) [4], The presence of degenerative hepatocytes in barbels and bleaks was also linked to mercury poisoning although it can also reflect the impact by other pollutants, like OCs or PBDEs (Fig. 3e). 

A completely different mode of interaction has been reported for Pt(en)2, which binds to double-stranded oligonucleotides in a noncova-lent manner. NMR studies have indicated that in the duplexes d(TCGGGATCCCGA)2 and d(CAATCCGGATTG)2 this square planar Pt(II) species selectively binds to the AT sequence in the minor groove [101]. It was suggested that the binding is stabilized by close van der Waals interactions as well as hydrogen bonds [101]. 

Barker, E. L., Perlman, M. A., Adkins, E. M Houlihan, W. J., Pristupa, Z. B Niznik, H. B and Blakely, R. D. (1998) High affinity recognition of serotonin transporter antagonists defined by species-scanning mutagenesis. An aromatic residue in transmembrane domain I dictates species-selective recognition of citalopram and mazindol. J. Biol. Chem. 273, 19459-19468. 

Maltby L, Blake N, Brock TCM et al (2005) Insecticide species sensitivity distributions the importance of test species selection and relevance to aquatic ecosystems. Environ Toxicol Chem 24 379-388... 

Most commonly, bioassays for the evaluation of the acute toxic effects of pesticides are based on single aquatic species selected to be representative of a range of taxonomic and functional groups, i.e., bacteria, algae, invertebrates or fish [ 53,54]. Generally, toxicity evaluation using a single species is the alternative of choice rather than the use of multiple species, because extrapolation of effects to an ecosystem is more difficult and can often lead to incorrect conclusions. 

The physiological similarity and phylogenetic proximity of nonhuman primates to humans are often cited as rationale for primate selection for safety studies especially when mechanisms of toxicity or pharmacologic action are expected to be closely related to potential physiological reactions in humans. Likewise, species selection is often based on the demonstration of pharmacologic activity of the test article. Many biopharmaceuticals do not exhibit their intended activity in nonprimate species, whereas small molecules may have activity across all species. 

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