Evaluating repellence properties of catnip essential oil against the mosquito species Aedes aegypti using a Y-tube olfactometer.

The mosquito species Aedes aegypti (L.) is known to act as a vector in the transmission of various diseases, including dengue fever and yellow fever. The use of insect repellents is one of precautionary measures used to mitigate the risk of these diseases in humans by reducing mosquito biting.

Aerobic Biostabilization of the Organic Fraction of Municipal Solid Waste-Monitoring Hot and Cold Spots in the Reactor as a Novel Tool for Process Optimization.

The process of aerobic biostabilization (AB) has been adopted for treatment of the organic fraction of municipal solid waste (OFMSW). However, thermal gradients and some side effects in the bioreactors present difficulties in optimization of AB. Forced aeration is more effective than natural ventilation of waste piles, but "hot and cold spots" exist due to inhomogeneous distribution of air and heat.

The influence of perforation of foil reactors on greenhouse gas emission rates during aerobic biostabilization of the undersize fraction of municipal wastes.

The opinion, that the use of foil reactors for the aerobic biostabilization of municipal wastes is not a valid method, due to vulnerability to perforation, and risk of uncontrolled release of exhaust gasses, was verified. This study aimed to determine the intensity of greenhouse gas (GHG) emissions to the atmosphere from the surface of foil reactors in relation to the extent of foil surface perforation. Three scenarios were tested: intact (airtight) foil reactor, perforated foil reactor, and torn foil reactor.

Distribution of beach litter along the coastline of Cádiz, Spain.

A total of 59 categories of litter items were found at 20 beaches (13 mechanically cleaned, 7 non-cleaned) in the Cádiz tourist environment, Spain. Cluster Analysis and Principal Components Analysis were used to highlight similarities and contrasts between sites and/or associations between litter categories. Multivariate analyses separated beaches according to the total numbers of litter items present.

Nitrogen removal from landfill leachate in constructed wetlands with reed and willow: redox potential in the root zone.

This study investigated the effects of reed and willow on bioremediation of landfill leachate in comparison with an unplanted control by measuring redox potential levels in the rhizosphere of microcosm systems in a greenhouse. Plants had a significant influence on redox potential relative to the plant-less system. Redox potential in the reed rhizosphere was anoxic (mean -102±85 mV), but it was the least negative, being significantly higher than in the willow (mean -286±118 mV), which had the lowest Eh.

Phytotoxicity of landfill leachate on willow--Salix amygdalina L.

Because of low investment and operational costs, interest is increasing in the use of willow plants in landfill leachate disposal. Toxic effects of leachate on the plants should be avoided in the initial period of growth and phytotoxicological testing may be helpful to select appropriate leachate dose rates. The aim of this study was to determine the phytotoxicity of landfill leachate on young willow (Salix amygdalina L.

Using fractal geometry to determine phytotoxicity of landfill leachate on willow.

Phytotoxicological tests were conducted during 6weeks on the willow Salix amygdalina using six concentrations of landfill leachate. Plants were exposed to landfill leachate solutions using two regimes: (A) - the willow shoots were watered by leachate solution from the beginning of the test; (B) - the willow shoots were cultivated in pots with clean water during 4weeks, then water was exchanged for leachate solutions. The tolerance of plants to prepared leachate concentration was determined by observations of morphological parameters of leaves including their fractal dimension.

Contrasting effects of n-3 and n-6 fatty acids on cyclooxygenase-2 in model systems for arthritis.

Cyclooxygenase-2 (COX-2) is intimately involved in symptoms of arthritis while dietary n-3 polyunsaturated fatty acids (PUFA) are thought to be beneficial. In these experiments, using both bovine and human in vitro systems that mimic features of arthritis, we show that the n-3 PUFA eicosapentaenoic acid (EPA) is able to reduce mRNA and protein levels of COX-2. Activity, as assessed through prostaglandin E(2) formation, was also reduced in a dose-dependent manner.

Cu and Cd effects on the earthworm Lumbricus rubellus in the laboratory: multivariate statistical analysis of relationships between exposure, biomarkers, and ecologically relevant parameters.

This study sets out to examine the potential of a suite of novel molecular biomarkers as early warning indicators of environmental state and damage. Transcriptional responses of four genes, metallothionein 1 and 2, amine oxidase, and the lysosomal associated glycoprotein, were measured in the earthworm Lumbricus rubellus exposed to increasing concentrations of cadmium and copper in OECD soil. These responses were compared to metal body concentrations and lifecycle parameters: survival, cocoon production, and growth.

Analysis of microbial community functional diversity using sole-carbon-source utilisation profiles - a critique.

Abstract Information on functional diversity (metabolic potential) is essential for understanding the role of microbial communities in different environments. Variations of the commercially available BIOLOG bacterial identification system plates are now widely used to assess functional diversity of microorganisms from environmental samples, based on utilisation patterns of a wide range (up to 95) of single carbon sources. There are many problems as well as benefits of using the approach, but the former are often disregarded.

Flow cytometry and other techniques show that Staphylococcus aureus undergoes significant physiological changes in the early stages of surface-attached culture.

The techniques of flow cytometry, scanning and transmission electron microscopy, and confocal scanning laser microscopy were used to study the physiology of Staphylococcus aureus in the early stages of surface-attached culture, and to make direct comparisons with planktonic bacteria grown under the same conditions. Attached bacteria growing in nutrient-rich batch culture were found to go through the same growth phases as equivalent planktonic cultures, but with an exponential growth rate of about half that of the planktonic bacteria. Viability of attached bacteria was very high (around 100%) throughout the first 24 h of growth.