Studies on the degradation of bis(tributyltin) oxide in soil

The degradation of bis(tri[1-¹⁴C]butyltin) oxide in two soils (1 mg tin kg^?1) has been studied under laboratory conditions. Half of the applied compound disappeared from unsterilised silt loam and sandy loam in approximately 15 and 20 weeks, respectively; it disappeared also from the sterilised soils but to a lesser extent. The formation of small amounts of dibutyltin derivatives was established by thin-layer chromatography both in the unsterilised and sterile soils. The amount of unextractable radioactivity increased with time in the unsterilised and sterile soils. In the unsterilised soils ¹⁴C was released as [¹⁴C]carbon dioxide in amounts equivalent to 20% of the applied radioactivity for silt loam and 10.7% for sandy loam over a period of 42 weeks. Almost no [¹⁴C]carbon dioxide was released from the sterile soils, confirming microbial participation in the degradation of the compound in the unsterilised soils.     

Dr. Georg August Pritzel 1815–1874Ein Gedenken zum 150. Geburtstag

Ohne Zusammenfassung     

Comment on "Fire-derived charcoal causes loss of forest humus"

Wardle et al. (Brevia, 2 May 2008, p. 629) reported that fire-derived charcoal can promote loss of forest humus and belowground carbon (C). However, C loss from charcoal-humus mixtures can be explained not only by accelerated loss of humus but also by loss of charcoal. It is also unclear whether such loss is related to mineralization to carbon dioxide or to physical export.     

Colloidal hard-sphere crystal growth frustrated by large spherical impurities

Impurities affect the nucleation, growth, and structure of crystals. Here we report the effect of large, spherical, polymethylmethacrylate impurities on the crystal growth of monodisperse, hard, polymethylmethacrylate colloids in a density- and optically matching apolar solvent mixture. Crystal growth, initiated at the bottom of the sample, was studied by imaging sequences of two-dimensional xy slices in the plane of the impurity's center with a laser scanning confocal microscope. Impurities form the center of grain boundaries, and a single fluid particle layer around the impurity persists in all cases. The growth rate sensitively depends on the impurity's size. Crystal growth is inhibited to a greater extent near smaller impurities, pointing to local crystal frustration induced by the curvature of the impurity.     

Atmospheric deposition to remote receptors II. Temporal and spatial variation of inorganic ion species in precipitation over the Ilwas-network

Water, Air, & Soil Pollution - Measurements of SO4 −, NO3 −, Cl−, NH4 +, Ca++, Mg++ Na+, K+, pH, and specific conductance, were made on a precipitation event basis (defined as...     

Angora goat gastrointestinal parasite knowledge and control practices among Lesotho farming communities

Tropical Animal Health and Production - Smallholder Angora goat farming is widespread throughout Lesotho, resulting in the country being ranked second in global mohair production. The Lesotho...     

Computed tomographic findings in a Bluetick Coonhound with a longitudinal thoracic tracheal tear

A 9‐year‐old intact male Bluetick Coonhound presented for progressive subcutaneous emphysema of 5 days’ duration due to a suspected tracheal tear. Cervical computed tomography (CT) and thoracic CT were performed after failure to identify the tracheal tear with tracheoscopy. A longitudinal tracheal tear was identified starting 4.3 cm cranial to the tracheal bifurcation and extending caudally over a distance of 3.6 cm. Severe pneumomediastinum, subcutaneous emphysema, and retroperitoneal gas were also present. A follow‐up CT 7 days postoperatively confirmed the successful repair of the tear with partial resolution of the presurgical secondary pathology and the patient recovered uneventfully.     

Growth response of advanced planted European beech (Fagus sylvatica L.) after storm-caused loss of shelterwood

European Journal of Forest Research - Outcomes after an abrupt, storm-caused loss of spruce shelterwood (Picea abies L. Karst.) overstories on advanced planted beech (Fagus sylvatica L.) were...     

Applications and future challenges in marine species distribution modeling

• 1. Anthropogenic climate change affects both phenology and distribution patterns of the world's biota including marine species. During the last decade, species distribution models have been more frequently used to assess the potential distributions of species and possible effects of climate change. However, unlike for terrestrial species, there have been few investigations assessing climate change effects on distribution patterns of marine organisms.
• 2. An overview of marine species distribution modelling is given. Possibilities of how to characterize and project the environmental niches of species onto climatic change scenarios are highlighted and novel techniques for addressing specific needs in a 3‐D context are proposed. A detailed introduction into different modelling tools and databases for environmental parameters given provides a starting point for the application of these models.
• 3. Application of a species distribution model and its projections onto a glacial and future scenario on a global scale are presented for the great white shark (Carcharodon carcharias) for illustrative purposes. An approach for addressing marine migratory species with seasonal distribution patterns is presented. Copyright © 2010 John Wiley & Sons, Ltd.

     

Serum pepsinogen levels to monitor gastrointestinal nematode infections in cattle revisited

The serum pepsinogen level is widely accepted as a useful parameter for monitoring gastrointestinal nematode infections in first-season grazing calves. However, several aspects, with possible implications for its practicality and the way to use the pepsinogen test, have received little attention to date. The objectives of this study were to evaluate (1) the reproducibility of a pepsinogen assay; (2) the required sample size for a reliable diagnosis and (3) the compliance to and effect of advice based on pepsinogen levels determined in year one on the nematode infection levels in the next generation of calves. Despite a high repeatability of the pepsinogen assay within the reference lab, the reproducibility between different labs was poor. There was more variation in pepsinogen levels between herds than between animals within a herd, suggesting that it is most useful to make a herd level diagnosis. Sample size calculation indicated that sampling seven animals sufficed to obtain a reliable indication of calf groups of up to 40 animals. Eighty-two herds were followed-up over two consecutive years and 39 (48%) had followed the advice that was formulated based on pepsinogen levels. Thirty-nine percent of the herds were advised to reduce the intensity of chemoprophylaxis. Samples from animals of those herds showed a higher pepsinogen level in the second year, but none of them had a mean pepsinogen level that is considered excessive. It is concluded that pepsinogen determination at housing from a limited number of animals can contribute to the design of the anthelmintic control strategy in the next year and a more targeted use of anthelmintics. However, more efforts are needed to harmonize the assay between veterinary diagnostic labs.