Suspected transient pseudohypoaldosteronism in a 10-day-old quarter horse foal

A 10-day-old quarter horse colt was presented for signs of disorientation and inability to nurse. Hydronephrosis/hydroureters, with concomitant pyelonephritis and a severe electrolytes disturbance, were diagnosed. The clinical findings closely resembled those described for a syndrome of transient pseudohypoaldosteronism in human neonates.     

Evaluation of the pathogenic potential of cervid adenovirus in calves.

Four 3-month-old Jersey calves and three 3-month-old Holstein calves were inoculated with cervid adenovirus and monitored for clinical signs until necropsied between 10 and 42 days postinoculation. The neonatal Jersey calves had received colostrum, and the Holstein calves were colostrum deprived. Preinoculation and postinoculation serum samples were tested for antibodies to the cervid adenovirus, bovine adenovirus type 6, bovine adenovirus type 7, and goat adenovirus type 1. Virus isolation was performed on kidney, nasal secretion, and/or lung homogenates in fetal white-tailed deer lung cells. Negatively stained preparations of feces from Jersey calves were examined weekly using an electron microscope, and weekly blood samples were collected for complete blood counts. Full necropsies were performed on all calves. A complete selection of tissues was evaluated for microscopic changes, and immunohistochemistry was performed on all tissues using a polyclonal antibody to deer adenovirus. No clinical signs were observed in the calves during the study period. Following inoculation, colostrum-deprived calves developed low antibody titers to deer adenovirus, while the Jersey calves that received colostrum did not. Calves that received colostrum had high antibody titers to bovine adenovirus type 7 and goat adenovirus type 1. No consistent gross or microscopic lesions were seen. Adenovirus was not observed in negatively stained preparations of feces. Immunohistochemistry results did not demonstrate virus in all tissues examined microscopically, and virus was not isolated from lungs, nasal secretions, and kidneys.     

Listeria associated mural and valvular endocarditis in an alpaca

An alpaca presented for emergency evaluation of respiratory distress. Physical examination revealed weakness, pyrexia, and a grade V/VI left apical holosystolic murmur. Initial thoracic examination and radiographs were consistent with left sided congestive heart failure. Blood cultures, echocardiographic evaluation, and necropsy findings established a diagnosis of bacterial endocarditis associated with a Listeria monocytogenes infection. Left ventricular endocarditis is uncommon in ruminants, and to the authors' knowledge there are no other reports of L. monocytogenes being the causative agent in an alpaca.     

The influence of soil processes on carbon isotope distribution and turnover in the British uplands

Understanding the natural variation of carbon within the soil, and between soil types, is crucial to improve predictive models of carbon cycling in high and mid-latitude ecosystems in response to global warming. We measured the carbon isotope distributions (¹²C, ¹³C and ¹⁴C) in soil organic matter (SOM) from Podzols, Brown Podzolic soils and Stagnohumic Gleysols from the British uplands, which were then compared with the total amounts and turnover of carbon in these soils. We did so by sampling at 2-cm intervals down six profiles of each soil type. The average amount of carbon stored in the top 28 cm of the Stagnohumic Gleysols is twice that of the other two soils. The ¹³C content and ¹⁴C age show a general increase with depth in all soils, and there is also a significant correlation between isotopic variation and the main pedogenic features. The latter suggests that soil-forming processes are significant in determining the carbon isotope signatures retained in SOM. Organic matter formed since 1960 is not found below 5 cm in any of the soils. Evidently organic detritus in the surface layers (LF and Oh) is rapidly mineralized. This accords with our modelled net annual C fluxes which show that more than 80% of the CO₂ emanating from these soils is derived from the top 5 cm of each profile. Although these soils contain much carbon, they do not appear to assimilate and retain SOM rapidly. The mean residence time of most of their carbon is in the 2–50 years range, so the soils are fairly ineffective sinks for excess CO₂ in the atmosphere. Under the predicted future ‘greenhouse’ climate, likely to favour more rapid microbial decomposition of organic materials, these soils are a potential source of CO₂ and are therefore likely to accelerate global warming.     

Arthroscopic Subchondral Bone Plate Microfracture Technique Augments Healing of Large Chondral Defects in the Radial Carpal Bone and Medial Femoral Condyle of Horses

OBJECTIVE: To evaluate the effect of arthroscopic subchondral bone microfracture on healing of large chondral defects in horses. STUDY DESIGN: Short- (4 months) and long-term (12 months) in vivo experimental chondral defect model. ANIMALS: 10 horses, aged 2 to 5 years. METHODS: Each horse had a 1 cm2 full-thickness chondral defect created in both radial carpal bones and both medial femoral condyles. One carpus and one femoral condyle of each horse had the subchondral bone plate under the defect perforated using an orthopedic awl. All horses were exercised, five horses were evaluated after 4 months and five horses after 12 months. Gross, histologic, and histomorphometric examination of defect sites and repair tissues was performed, as was collagen typing of the repair tissue. RESULTS: On gross observation a greater volume of repair tissue filled treated defects (74%) compared with control defects (45%). Histomorphometry confirmed more repair tissue filling treated defects, but no difference in the relative amounts of different tissue types was observed. There was an increased percentage of type II collagen in treated defects compared with control defects and evidence of earlier bone remodeling as documented by changes in porosity. CONCLUSIONS: In full-thickness chondral defects in exercised horses, treatment with subchondral bone microfracture increased the tissue volume in the defects and the percentage of type II collagen in the tissue filling the defects when compared to nontreated defects. CLINICAL RELEVANCE: No negative effects of the microfracture technique were observed and some of the beneficial effects are the basis for recommending its use in patients cases with exposed subchondral bone.     

Ontology-based simulation in agricultural systems modeling

A methodology and applications of ontology-based simulation are presented. An environment for building simulations based on the Lyra ontology management system is described which includes web-based visual design tools for constructing models and automatically generating simulation code. The ontology is used for representing all equations and all symbols appearing in these equations that are needed to describe a model. The example applications presented are models of soil, water, and nutrient management in citrus and sugarcane. Results thus far show that the ontology-based approach has advantages for representing the model structure, equations, and symbols, that complex models can be described in this format, and that efficient simulation code can be generated automatically from the ontology definition of the model. Potential applications, not yet fully explored, include ability to automatically connect models and data sources, using the ontology to organize model bases containing many models and model components, and using ontology reasoners to search for models, automatically discover model similarities and differences, and generate model instances from general principles.     

Consumer acceptance of transgenic crops

It has long been recognised that a key determinant of the future development of genetic engineering in food production is likely to be consumer acceptance. Much of the earlier research into acceptance issues has assumed that public perceptions of genetic engineering are defined by beliefs about the technology overall. However, it is now known that acceptance of novel products is unlikely to be related to general attitudes towards genetic engineering. People's perceptions of risk and benefit associated with particular products and applications will determine acceptance. There is a need to develop effective risk–benefit communication strategies, based on the best scientific information available, in order to enable the public to make informed choices about consuming the products of genetic engineering. It is also essential to develop effective communication methods if the public is to contribute to the wider debate about strategic development of genetic engineering. Issues of social context (such as trust in risk regulators) must also be considered. Providing information is likely to change people's attitudes, which will in turn generate further public concerns and create a demand for more information about genetic engineering. © 1998 SCI     

The effect of thiopental sodium, methoxyflurane and halothane on the acid-base status in sheep.

Experiments have been carried out on 20 adult fat-tailed ewes to determine the effects of thiopental sodium, methoxyflurane and halothane on acid-base status of the saliva loss during prolonged surgical anaesthesia. The rate of loss of base in saliva depends on the volume of saliva produced, which fell sharply at the onset of anesthesia with the volatile anaesthesia. Plasma pH and plasma pvCO2 excess were both increased by the volatile anaesthetics but fell sharply during thiopental anaesthesia. Plasma pH and plasma PvCO2 showed no consistent relationship.     

Simulation study of the competitive ability of erect, semi-erect and prostrate cowpea (Vigna unguiculata) genotypes

Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterised, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower than companion field experiments for the competition of cowpea and purslane. The validated simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habit on final biomass production of cowpea and sunflower. The model suggested that erect growth habit was more competitive than semi‐erect and prostrate growth habit, when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass. Our simulation approach is suggested as a method for crop breeders to gauge the likely success of selection for competitive crops before undertaking expensive long‐term breeding experiments.