Ecological diversity of sediment rhizobacteria associated with Phragmites australis along a drainage canal in the Yellow River watershed

Journal of Soils and Sediments - Spatial distribution on a regional scale of the rhizobacterial communities of Phragmites australis stands was investigated along the Yellow River watershed, China....     

Regionalizing soil properties in a catchment of the Bavarian Alps

Regionalizing information on soil hydraulic properties is a fundamental task for solving many soil related ecological problems at the landscape scale. The objective of this study was to derive this information from readily available topographical and geological data for the watershed of the Halbammer (42 km²) in the Bavarian Alps. The database consisted of 297 profiles taken during a 1 month field survey in summer 2001 and the topographical and geological maps (1:25,000) of the area. Soil profiles were grouped into six pedogenetic units taking into account the water regime of the profile and its texture. Another classification was done that relied only on texture and bedrock material as to describe the soil hydrological properties independently from their position in the landscape. In order to regionalize these classes, the tree based CART-Algorithm was used. This algorithm creates optimal classification trees based on a classified training sample and available parameters. The decision rules of these trees then served as basis for the derivation of soil maps that were created using the geographical information system ArcGIS 9.2. The accuracy of the regionalization was estimated using mathematical criteria as well as human expertise. Six to ten units proved to be a good number concerning the available data, but even then not all of them could be separated by CART. The performance of the CART algorithm is measured by the decrease of the misclassification error of an optimally pruned classification tree. In our study, the decrease of the misclassification reached 32 resp. 26% compared to a uniform classification of all data into the most frequent soil unit. The distributions of soil classes in the terminal nodes of the classification trees were useful for the interpretation of the soil units in the maps’ legends and also helped to identify typical soil patterns in the study area. According to these results, CART seems to be a suitable tool for regionalizing soil-related data, but human expertise is still needed to create plausible soil maps out of the information the CART algorithm provides.     

Scoring of the extent and intensity of carp (Cyprinus carpio) skin changes made by cormorants (Phalacrocorax carbo sinensis): relationship between morphometric and histological indices

Cormorants cause damage to fish in aquaculture not only by consuming large number of fish but also by wounding them. Quantification of the actual damage in fish induced by wounding is important for reliable estimations of the overall loss in aquaculture caused by cormorants. In this study, specimens of mirror and scaly carp (Cyprinus carpio L.) injured by attacks of great cormorant (Phalacrocorax carbo L.) were collected from the ??E?ka?? fish farm in Serbia. Surfaces of superficial and open subepithelial wounds (expressed as a percent of the total body surface), estimated by computer-assisted image analysis, had mean values 10.66?±?1.86 and 0.85?±?0.90, respectively. Histological evaluation of wounds was performed by two scoring systems: system proposed by Bernet et al. (J Fish Dis 22:25?C34, 1999) and modified system described by Wahli et al. (Aquaculture 225:371?C386, 2003). The most frequent histopathological changes were disturbed epidermal structure and surface cell morphology and increased number of club cells (on more than 75% of specimens); increased number of melanocytes and their distribution in different layers in dermis; and enlarged hypodermis (more than 80% of samples) and myolysis (50% of samples). Comparison of wounds?? surfaces (surface of superficial injures) and histopathological changes, estimated by two scoring systems, revealed significant positive correlation. Bernet??s scoring system showed higher correlation coefficients, when compared with the modified Wahli??s scoring system.     

Annual variation in predation and dispersal of Arolla pine (Pinus cembra L.) seeds by Eurasian red squirrels and other seed-eaters

Seed predation and dispersal are key processes in the survival and distribution of plant species. Many animals cache seeds for later consumption, and, failing to recover some of these seeds, act as seed dispersers, influencing post-dispersal seed and seedling survival. Both animal and plant benefit from scatterhoarding and natural selection of seed characteristics and adaptations of seed predators (and dispersers) is one of the most important examples of co-evolution and mutualism. We studied the producer–consumer Arolla pine (Pinus cembra)–red squirrel (Sciurus vulgaris) system in a subalpine forest in the Italian Alps. Arolla pine produced large seed-crops (masting) at irregular intervals, followed by years with poor or moderate seed production. Squirrel density fluctuated in synchrony with the food resource, eliminating the time-lag normally present when resources are produced in pulses. In all years except 2009 (a mast-crop year), all Arolla pine cones were harvested (their seeds consumed and/or cached) by September to late October by different species. Both squirrels and nutcrackers (Nucifraga caryocatactes) fed on seeds, and their relative pre-dispersal predation rates (on cones in the canopy) differed between years. Overall, nutcrackers consumed more seeds between July and October than squirrels, but in 1 year squirrels took the largest number of seeds. Pre-dispersal seed predation by squirrels tended to be lower in years with large seed-crop size and there was a positive correlation, over the entire study period, between density of recovered hoards and Arolla pine seed density of the previous year. We conclude that (i) squirrels and nutcrackers are important pre-dispersal seed predators and seeds dispersers; (ii) squirrels are also post-dispersal seed predators, and (iii) the proportion of cached seeds consumed by squirrels increased with the size of the Arolla pine seed-crop, suggesting that red squirrel is a conditional mutualistic scatterhoarder of Arolla pine seeds.     

Concentrations of clindamycin in the mandibular bone of companion animals

Concentrations of clindamycin in the mandible were determined in 17 dogs and 13 cats with severe plaque, gingivitis/periodontitis, and calculus that were treated orally with clindamycin (11 mg/kg) once daily for 5 days prior to professional teeth cleaning and extractions. The animals were patients at the Dental Department of the Clinic for Surgery and Ophthalmology of the University of Veterinary Medicine in Vienna, Austria. Clindamycin levels were determined during postextractional alveoloplasty. Approximately 1 to 3 mm3 of mandible was removed from the intraradicular septum in multirooted teeth and from the protruding labial/buccal alveolar rim with a small rongeur. The mean concentration of clindamycin was 8.18 microg/g in dogs (range=3.16 to 24.08 microg/g) and 17.43 microg/g in cats (range=2.45 to 51.60 microg/g). The concentration of clindamycin in the mandibles of dogs and cats may be useful to combat infections after periodontal procedures, tooth extractions, or injuries to the mandible.     

Evaluation of Erysiphe graminis f sp tritici field isolates for resistance to strobilurin fungicides with different SNP detection systems

A single nucleotide polymorphism (snp) in the cytochrome b gene confers resistance to strobilurin fungicides in Erysiphe graminis DC fsp tritici Marchal. On the basis of this point mutation three different types of molecular markers have been developed. Cleaved amplified polymorphic sequences and allele-specific PCR were used to score resistant and sensitive isolates from specifically selected regional populations across Europe. The results of molecular tests were in total agreement with the resistance phenotypes revealed by in vivo tests. Serial dilutions of mixed samples (resistant/sensitive) delimited the detection for strobilurin-resistant alleles to a range of 10-50% for both marker classes. Due to these detection limits no mixture of mitochondria within individual isolates was found. Denaturing high performance chromatography was used to increase the detection sensitivity for the mutant allele. Although the detection limit was lowered to 5-10%, there was no evidence for the existence of mixed mitochondrial genotypes.     

Laparoscopic ovariectomy in mares using a polyamide tie-rap

OBJECTIVE: To describe use of a polyamide tie-rap to ligate the mesovarium during standing laparoscopic ovariectomy in mares. STUDY DESIGN: Prospective study. ANIMALS: Ten mares. METHODS: Bilateral ovariectomy was performed in 10 mares. Standing laparoscopic ovariectomy was performed using 3 portals in the paralumbar fossa. A commercial polyamide tie-rap was prepared as a loop and marked with 4 colored lines close to the buckle, to enable us to check whether the loop was tightened securely. The ovary was grasped with forceps and after the mesovarium was minimally transected cranially and caudally, the loop of the tie-rap was inserted in the abdomen and placed around the mesovarium. It was firmly tightened, until at least 3 of the 4 marks were visible, then the end of the tie-rap was cut. The ovary was transected and removed through an enlarged 3rd portal. The contralateral ovary was removed similarly through the opposite paralumbar fossa. Repeat laparoscopy was performed in 8 mares, 2, 3, 4, and 12 weeks later. RESULTS: None of the mares had postoperative discomfort. On repeat laparoscopy, there was complete encapsulation of the stump and tie-rap after 3-4 weeks. In 2 mares, an adhesion between the left stump and the mesentery of the descending colon was observed. CONCLUSION: Ligation of the mesovarium can be easily and safely performed using a polyamide tie-rap during standing laparoscopic ovariectomy in mares. CLINICAL RELEVANCE: Standing laparoscopic ovariectomy using a polyamide tie-rap is a safe, technically easy and reliable surgical procedure in the mare.     

Surgical correction of ear curling caused by scar tissue formation in a horse

An 18-month-old Belgian Warmblood mare was evaluated because it had injured the outer convex aspect of the left auricle. Second intention healing of the wound area caused tissue contracture, which resulted in the tip of the ear curling backward. By use of a technique involving undermining of the skin and a flap of granulation tissue on the medial aspect of the wound area and multiple incisions of the auricular cartilage, the curling was relieved and the ear regained a more normal shape. A skin graft was applied to cover the existing wound defect in an attempt to accelerate wound healing; thermoplastic material was contoured to fit the inner concave surface of the ear for immobilization and fixation of the ear in its final shape after surgery. Thirty days after surgery, the graft had healed completely and the ear had a normal conformation. The successful outcome of this treatment suggests that correction of an ear deformity secondary to scar tissue formation by use of an adapted surgical technique and appropriate materials can be achieved with good cosmetic results in horses.     

Effect of storage on bovine erythrocyte cholinesterase activity.

Bovine whole blood and washed erythrocyte samples with either sodium heparin or EDTA as the anticoagulant were stored at -24, 2 to 3, 21, or 37 C for up to 8 weeks to determine the stability of erythrocyte cholinesterase (ChE) activity. An automated colorimetric method was used to measure ChE activity. Regression analysis was used to estimate the rate of decline of ChE activity of samples to 95% of normal. Samples stored at -24 and 2 to 3 C were very stable, and ChE activity was maintained for several weeks or longer. Samples stored at 21 C maintained an activity level not less than 95% of normal for at least 9 days and those stored at 37 C for at least 2 days. The type of anticoagulant used did not appear to affect significantly the stability of activity.