Using Caenorhabditis Elegans As An Environmental Indicator for Impaired Urbanized Watersheds

Background Third Fork Creek is a historically impaired urban stream that flows through the city of Durham, North Carolina. Caenorhabditis elegans (C. elegans) are non-parasitic, soil and aquatic dwelling nematodes that have been used frequently as a biological and ecotoxicity model. We hypothesize that exposure to Third Fork Creek surface water will inhibit the reproduction and chemotaxis of C. elegans. Using our ring assay model, nematodes were enticed to cross the impaired water samples to reach a bacterial food source which allowed observation of chemotaxis. The total number of nematodes found in the bacterial food source and the middle of the plate with the impaired water source was recorded for three days. Results Our findings suggest a reduction in chemotaxis and reproduction on day three in nematodes exposed to Third Fork Creek water samples when compared to the control (pvalue<0.05). These exploratory data provide meaningful insight to the quality of Third Fork Creek located near a Historically Black University. Conclusions Further studies are necessary to elucidate the concentrations of the water contaminants and implications for human health. The relevance of this study lies within the model C. elegans, that has been used in a plethora of human diseases and exposure research but can be utilized as an environmental indicator of water quality impairment.

Evaluation of Methionine Sources in Protein Reduced Diets for Turkeys in the Late Finishing Period Regarding Performance, Footpad Health and Liver Health

Footpad dermatitis and hepatic lipidosis are health problems in fattening turkeys where a positive influence of higher methionine content in feed is discussed. The effects of the methionine supplements DL-methionine (DLM) and liquid methionine hydroxyl analogue free acid (MHA-FA) under the aspect of low protein diets were investigated in this study based on performance parameters, footpad health, liver health and oxidative stress. In this study, 80 female turkeys (B.U.T. Big 6) of 63 day-old, were randomly assigned to four groups characterising a 2 × 2 factorial design with five replicates each over five weeks. The groups were fed with diets differing in methionine source (DLM vs. MHA-FA, assuming a biological activity of MHA-FA of 65%) and crude protein content (15% vs. 18%) for 35 days. The results showed no significant interactions between the protein content and methionine source. Strong protein reduction significantly impaired water intake, feed intake, weight gain and feed conversation ratio, but improved footpad health. DLM and MHA-FA addition had no significant effect on weight gain, crude fat and protein contents in the liver, but DLM resulted in a significant increase in livers antioxidative capacity compared to MHA-FA. Although the protein reduction resulted in reduced performance, the study showed that MHA-FA can be replaced by DLM in a 100:65 weight ratio without compromising performance but with certain advantages in the antioxidative capacity of the liver.

The Effect of Class C Fly Ash on the Water Impermeability of Brick Body

The effect of fluidized fly ash (Tisová, ČEZ Group Czech Republic, class C according to ASTM C618) on the porosity (water absorption, bulk density, capillarity) and water impermeability of brick body used for the production of clay roofing tiles (Wienerberger, Czech Republic). The properties of plastic body (mixing water, drying shrinkage) are discussed too. The addition (10 %wt) of fluidized fly ash in the raw materials mixture for the production of clay roofing tiles generally reduces the sensitivity to the formation of reducing cores during firing thanks to higher porosity of dried green body (higher mixing water) - this is also related to the higher water absorption and capillarity of the fired body and hence to the impaired water impermeability when the fly ash is used.

Angiotensin II-Vasopressin Interactions in The Regulation of Cardiovascular Functions. Evidence for an Impaired Hormonal Sympathetic Reflex in Hypertension and Congestive Heart Failure

Conclusion: Hormonal imbalance between ANG II, VP, and SNS may induce hypertension and impaired water-electrolyte balance in cardiovascular diseases.

THE NEGATIVE IMPACT OF HIKING ON THE MOUNTAIN ENVIRONMENT – THE POSITION OF POLISH SCIENTISTS IN COMPARISON TO GLOBAL LITERATURE

Purpose. In this article, the position of Polish scientists is presented with regard to the impact of hiking on the environment, particularly mountain areas, by reference to the broader context of selected works of global literature. Method. The paper is mainly in the form of a review of literature connected with Earth sciences, chiefly geomorphology. Particular emphasis is placed on the effects of hiking, which have been divided by impact type (e.g. compaction and soil erosion, initiation of morphogenetic processes, impaired water circulation, destruction of plant biomass and changes in the plant and animal world). Findings. The Polish scientific contribution to the subject area presented should be considered significant, however, it does differ in certain characteristics from the achievements of the wider world. Considerable attention has been devoted to means of counteracting particular negative effects of tourism, both the technical (remodelling of trails and their surroundings) and organisational aspects (management of tourist traffic). Research and conclusions limitations. The position of Polish science is mostly presented, however, this is done in comparison to the broader global literature on the topic. Practical implications. The suggested means of counteracting the negative effects of hiking may be useful while planning tourist infrastructure, especially in protected areas. Originality. In the paper, a complex review is presented regarding the opinions of Polish scientists, not only on the topic of the negative impact of hiking, but also methods of its prevention. Type of paper. Literature review.