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Variables Indicative (variable + indicative)
Selected Abstracts59 Utility of the periphyton index of biotic integrity (PIBI) as an indicator of acid mine drainage impacts in southeastern ohioJOURNAL OF PHYCOLOGY, Issue 2003S. E. Hamsher In the Appalachian region, numerous streams are polluted with acid mine drainage (AMD). These waters are sulfate-rich with elevated amounts of total acidity, low pH, and high levels of dissolved metals. Biotic multimetric indices, such as the Periphyton Index of Biotic Integrity (PIBI) have been employed to determine water quality across a variety of environmental conditions and may prove useful for AMD impacts. This study was initiated (1) to evaluate the PIBI for distinguishing AMD impact in streams and (2) to examine whether PIBI scores are impacted by seasonal differences. Twelve AMD and three reference streams were sampled for periphyton in June, August, and October. Water chemistry was collected at least once during the sampling period. Preliminary results showed that PIBI scores were significantly different (p<0.05) among the seasons. In addition, the seasonal trends in PIBI scores among streams were not consistent. The PIBI scores were correlated with six water chemistry variables in August and with at least one variable indicative of AMD in each season sampled. PCA and UPGMA analyses of water chemistry data grouped the streams into five categories: (1) moderately impacted AMD streams with lower total dissolved solids, sulfate, total aluminum, and alkalinity, and higher sulfate; (2) AMD streams with higher alkalinity and lower total aluminum; (3) AMD streams with lower alkalinity and higher total aluminum; (4) reference streams and (5) an outlier reference stream affected by nutrients. Relationships between the groups based on water chemistry and the groups derived from the PIBI will be discussed. [source] Haematological, hepatic and renal alterations after repeated oral and intraperitoneal administration of monoisoamyl DMSA.JOURNAL OF APPLIED TOXICOLOGY, Issue 2 2003Abstract We recently reported the effects of repeated administration of the monoisoamyl ester of dimercaptosuccinic acid (MiADMSA) on a few selected biochemical variables indicative of haematopoietic, liver, kidney and brain toxicity, oxidative stress and essential metal status in male rats. The present investigation studies similar changes in female rats to ,nd out if the changes are independent of gender. The results suggest signi,cant and pronounced toxic effects of MiADMSA on haem biosynthesis, liver and kidneys in female rats exposed to higher doses of orally (p.o.) or intraperitoneally (i.p.) administered MiADMSA, compared with the effects in male rats. No effects on brain tissues were seen. A pronounced depletion of copper was noted in the blood and liver of MiADMSA administered rats, irrespective of route of exposure. It can be concluded that the administration of MiADMSA in female rats is confounded with side-effects and may require caution during its use and further exploration. Copyright © 2003 John Wiley & Sons, Ltd. [source] Changes in brain biogenic amines and haem biosynthesis and their response to combined administration of succimers and Centella asiatica in lead poisoned ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2006Geetu Saxena This study was designed to investigate the therapeutic potential of meso 2,3-dimercaptosuccinic acid (DMSA) and one of its monoesters, monoisoamyl DMSA (MiADMSA), individually or when administered in combination with an extract of Centella asiatica against experimental lead intoxication in rats. Biochemical variables indicative of alterations in the central nervous system and haem biosynthesis were investigated to determine the toxicity in male Wistar rats. Thirty five rats were exposed to 0.2% lead acetate for 10 weeks, followed by 10 days of treatment with DMSA and MiADMSA (50 mg kg,1, i.p., once daily) alone and in combination with C. asiatica (200 mg kg,1, p.o., once daily). Biochemical variables indicative of oxidative stress and brain biogenic amines, along with lead concentration in blood and brain, were measured. Lead exposure caused a significant depletion of blood and brain ,-aminolevulinic acid dehydratase (ALAD) activity, an important enzyme of the haem biosynthesis pathway, and glutathione (GSH) level. These changes were accompanied by a marked increase in reactive oxygen species (ROS) level, thiobarbituric acid reactive substances (TBARS), ,-aminolevulinic acid synthase (ALAS) and oxidized glutathione (GSSG) activity in blood and brain. Significant depletion of brain noradrenaline (norepinephrine, NE), 5-hydroxytryptamine (5-HT), dopamine (DA) and acetylcholinesterase (AChE) also were observed following lead exposure. Also seen was a significant depletion in brain glutathione peroxidase (GPx), glutathione S-transferase (GST) and monoamine oxidase activity, as well as blood and brain superoxide dismutase (SOD) activity. These biochemical changes were correlated with an increased uptake of lead in blood and brain. Combined administration of MiADMSA and C. asiatica was most effective in reducing these alterations, including biogenic amines, besides reducing body lead burden, compared with individual treatment with MiADMSA. Certain other biochemical variables responded favourably to combination therapy and monotherapy with MiADMSA. Thus, supplementation of C. asiatica during chelation could be recommended for achieving optimum effects of chelation therapy. [source] An analysis and review of models of the sociobiology of the MustelidaeMAMMAL REVIEW, Issue 3-4 2000Dominic D. P. Johnson ABSTRACT Classical models of social organization in mustelids suggest that female ranging patterns are determined by the dispersion of resources, whereas those of males are determined by the dispersion of females. However, mating systems and social spacing patterns vary widely both between and within species. For example, European Badgers exhibit a continuum from the classical mustelid model of intra-sexual territoriality and inter-sexual overlap to very large, mixed-sex, promiscuous groups. We evaluated hypotheses and existing data to explain this variation, using comparative analyses and Principal Components Analysis of life history and ecological variables. In addition, we applied a null model of allometric scaling to test for associations between group mass and residual home range size. We found that: (1) the degree of social behaviour and breeding group size increased with life history variables indicative of K-selected strategies of parental investment. (2) Absolute home range size and residual home range size (derived from allometric home range scaling) decreased, paradoxically, with breeding group size and group mass, respectively. These results provide support for ecological theories of social grouping in general and, in particular, for the importance of dispersed resource-rich patches as developed in the Resource Dispersion Hypothesis. [source] Protective value of Aloe vera against some toxic effects of arsenic in ratsPHYTOTHERAPY RESEARCH, Issue 1 2005Richa Gupta Abstract Concomitant oral supplementation of Aloe vera, (1, 2 or 5% w[sol ]v in drinking water) during arsenic exposure (0.2 mg[sol ]kg, intraperitoneally, once daily for 3 weeks) was investigated in rats for its protective value. Animals exposed to arsenic (III) showed a significant inhibition of , -aminolevulinic acid dehydratase (ALAD) activity, a marginal decrease in glutathione (GSH) and an increase in zinc protoporphyrin (ZPP) level in blood. White blood corpuscles (WBC) level decreased while most of the other clinical blood parameters like red blood cells count, haemoglobin, MCV, MCH, MCHC ratio and platelet number, etc. remained unaltered on arsenic exposure. Hepatic reduced GSH, oxidized glutathione (GSSG) level remained unaltered, thiobarbituric acid reactive substance (TBARS) level increased significantly while the activity of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and catalase decreased on arsenic exposure. Renal GSH contents decreased while superoxide dismutase (SOD) activity decreased significantly on arsenic exposure. Concomitant administration of Aloe vera had remarkable protective action on inhibited blood ALAD activity and restored blood GSH level while most of the other blood biochemical parameters remained unchanged on Aloe vera supplementation. Interestingly, most of hepatic biochemical variables indicative of oxidative stress showed protection; no effect of Aloe vera on blood and liver arsenic concentration was noted. Also, no effect of Aloe vera on most of the altered renal biochemical parameters were noticed. The results thus lead us to conclude that simultaneous supplementation of Aloe vera protects against arsenic induced oxidative stress but does not influence the arsenic concentration in these organs. Copyright © 2005 John Wiley & Sons, Ltd. [source] Lake habitat suitability for the rare European macrophyte Najas flexilis (Willd.) Rostk.AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2005& Schmidt Abstract 1.Najas flexilis (Willd.) Rostk. & Schmidt is a submerged annual macrophyte, rare in Europe, which is protected under the EC Habitats Directive. 2.N. flexilis grows in deep, often coloured or turbid water in mesotrophic lakes. Because of this habitat preference it is difficult to locate and assess the ecological state of populations of the species for conservation monitoring purposes. 3.A method is described based on plant community information that can be used to determine the baseline probability that conditions in a lake are suitable for supporting N. flexilis growth. This can be applied to conservation management decisions, such as whether a detailed underwater survey is justified for monitoring the integrity of existing populations of N. flexilis, or whether the lake may be a suitable site for introduction, or reintroduction, of populations of the plant. 4.Two methods of plant community description are compared: a quantitative micro-habitat scale approach and a whole-lake-scale qualitative approach. Plant community data collected using each method were grouped using TWINSPAN, and environmental descriptors of the sites comprising each plant community group were compared statistically. 5.Micro-habitat-scale community groups differed significantly only in the light extinction coefficient, indicating the zone within the lake in which N. flexilis occurred. 6.The whole-lake-scale community groups differed in a number of environmental variables indicative of eutrophication and acidification, two major environmental threats to N. flexilis survival. 7.This study suggests that a lake-scale qualitative plant community description would be a better indicator of site suitability for N. flexilis growth than a quantitative micro-habitat plant community description. This is because the whole-lake-scale approach could detect a difference in the environmental factors that affect N. flexilis growth, which the micro-habitat scale approach could not. Copyright © 2005 John Wiley & Sons, Ltd. 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