Species studied

The Table of Contents for this collection will facilitate this discussion. Notice that the papers are grouped into the categories of Atmospheric, Aquatic and Terrestrial Components, Global Carbon Cycle and Climate Change, and Global Environmental Science Education. The reader may want to consider the various chemical species studied in each paper. Next, the reader may wish to group the papers by whether they address the source or the receptor, the transport or transformation processes for the chemical species. Finally, the reader needs to establish the time scales and the spatial resolution used. 

Protection Studies. Animals were given a sublethal dose of palytoxin followed at various time intervals by a lethal dose. Control and treatment data for each route of administration and species studied are given in the appropriate table (Tables III, IV, V, and VI). 

C13-0102. hi the 1950s, Edwin Chargaff of Columbia University studied the composition of DNA from a variety of plants and animals. He found that the relative amounts of different bases changed from one species to another. However, in every species studied, the molar ratios of guanine to cytosine and of adenine to thymine were found to be very close to 1.0. Explain Chargaff s observations in terms of the Watson-Crick model of DNA structure. 

Rifampicin is the semisynthetic derivative used widely in the UK. Resistance to rifampicin is primarily due to chromosomal mutations resulting in an altered RNA polymerase which is less well inhibited by the drug. The mutations tend to be clustered within short conserved regions of the J3 subunit gene of RNA polymerase. Similar mutations have been found in all bacterial species studied thus far. 

There is little new with regard to the mu receptor, the main target for opioid drugs. The receptor is remarkably similar in structure and function in all species studied so animal studies will be good predictors for clinical applications. Although there have been suggestions of subtypes of the receptor, the cloned mu receptors have all been identical. 

A typical dose-response is shown in Fig. 11.1. This assumes that a dose exists which has no effects due to the capacity of the body to reverse minor changes and maintain cellular homeostasis. The threshold dose is normally taken to be the observed experimental NOAEL, but the NOAEL could be lower than the threshold dose. The NOAEL chosen is the one that represents the most sensitive species studied since all international protocols require that the chemical is tested on at least two species (frequently the rat and the mouse). 

Materials and methods. Each species studied was grown in the greenhouse in a growth unit constructed from 10 cm PVC drain pipe and T-fittings, as described previously. The growth units were filled with an artificial soil mix of perlite/coarse sand/coarse vermlculite 3/2/1 by volume. On the second and fifth day of each week four liters of a full strength Peter s Hydro-sol solution plus calcium nitrate (36.7 g/37.8 liters plus 17.0 g Ca(N03 )2 /37.8 liters) were added to each growth... 

The results of the bloassays reported here Indicate that some of the species studied may release phytotoxins into the environment. Further work is needed to identify any active compounds and determine their influence in the field. 

Fat tissues do not appear to highly concentrate diisopropyl methylphosphonate or its metabolites. Tissue blood ratios for adipose deposits range from 1.3 to 3.6 in the species studied (Hart 1976). There was a surprisingly high concentration of radiolabel in the skin for mice with a tissue blood ratio of 14.6 (Hart 1976). It has been suggested, however, that the skin samples were contaminated with urine. 

Spirodela intermedia, L. minor, and P. stratiotes were able to remove Pb(II), Cd(II), Ni(II), Cu(II), and Zn(II), although the two former ions were removed more efficiently. Data fitted the Langmuir model only for Ni and Cd, but the Freundlich isotherm for all metals tested. The adsorption capacity values (K ) showed that Pb was the metal more efficiently removed from water solution (166.49 and 447.95 mg/g for S. intermedia and L. minor, respectively). The adsorption process for the three species studied followed first-order kinetics. The mechanism involved in biosorption resulted in an ion-exchange process between monovalent metals as counterions present in the macrophytes biomass and heavy metal ions and protons taken up from water.112... 

Emission rates, modes, locations, and times must be described for each species studied. The emission work was done by Hydroscience, Incorporated (HI), of Knoxville, Tennessee. Emission characterization involved review of trade literature, files of the various states, EPA reports and data, and site visits and correspondence with staff of specific sources. 

Figure 7. Carbon stock and contribution of each carbon pool studied (AGB includes only five species studied). The acronyms AGB10, AGB0 and SOC are explained in the text.

The Pedemontana Jungle sectors that have been left isolated are subject to edge effect, with changes clearly visible in microclimatic variables. The AGB in fragments is notably reduced for the main five tree species studied, but the species composition has also changed. 

Meunier, F.C., Tibiletti, D., Goguet, A., Shekhtman, S., Hardacre, C., and Burch, R. 2007. On the complexity of the water-gas shift reaction mechanism over a Pt/Ce02 catalyst Effect of the temperature on the reactivity of formate surface species studied by operando DRIFT during isotopic transient at chemical steady-state. Catal. Today 126 143 17. 

Several authors observed CL emission based on reduction reactions. Lu et al. [59] developed a method by applying a Jones reductor for producing unstable reductants. A column (100 X 3 mm i.d.) filled with Zn-Hg particles was inserted into the flow stream of a flow injection system. CL was measured using a homemade CL analyzer. Although the Jones reductor was more effective for the species studied in 0.5-5 mol/L H2S04 solution, the authors found that a lower acid concentration improved the CL emission. Hie optimal pH was 6.5 for V(II), 2.5 for Mo(III), 3.5 for U(III), 3.0 for W(III), 3.0 for Cr(II), 2.5 for Ti(III), and 2.5 for Fe(II). The methods allowed determination of the above-mentioned species at pg/mL to ng/mL levels. It was assumed that the CL reactions were related to the production of superoxide radicals by dissolved oxygen in the solutions. The proposed methods could be successfully applied to the determination of V [60], Mo [61], and U [62] in water or steel samples. 

Hence, the low THg levels reported in both barbel and bleak specimens sampled upstream the chlor-alkali plant in Monzon, suggest that neither of these fish species migrate upstream the factory, and therefore the fishing area upstream from Monzon does not carry a very high risk to public health, at least for these two fish species studied. 

The data in Table 4-1 indicate that myelin accounts for much of the total lipid of white matter, and that the lipid composition of gray matter is quite different from that of myelin. The composition of brain myelin from all mammalian species studied is very much the same. There are, however, some species differences for example, myelin of rat has less sphingomyelin than does that of bovine or human (Table 4-1). Although not shown in the table, there are also regional variations for example, myelin isolated from the spinal cord has a higher lipid-to-protein ratio than brain myelin from the same species. 

Dimethylarsinic acid is the major metabolite of orally administered arsenic trioxide, and is excreted rapidly in the urine (Yamauchi and Yamamura 1985). The methylation process is true detoxification, since methanearsonates and cacodylates are about 200 times less toxic than sodium arsenite (NAS 1977). The marmoset monkey (Callithrix jacchus), unlike all other animal species studied to date, was not able (for unknown reasons) to metabolize administered As+5 to demethylarsinic acid most was reduced to As+3. Only 20% of the total dose was excreted in urine as unchanged As+5, and another 20% as As+3. The rest was bound to tissues, giving distribution patterns similar to arsenite (Vahter and Marafante 1985). Accordingly, the marmoset, like the rat, may be unsuitable for research with arsenicals. 

SP Indicator test species Study type Endpoint Toxicity... 

Cypermethrin Winter Wheat 0.595 (drift rate) and 25 g a.i./ha (2 app at 14 day intervals) Effects reported on a wide range of species studies at both 0.595 and 25 g a.i./ha Recovery reported for all taxonomic groups 38-40 days after 2nd application of both 0.595 and 25 g a.i./ha... 

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