A novel approach to studying the effects of temperature on soil biogeochemistry using a thermal gradient bar

The temperature dependence of chemical reaction rates and microbial metabolism mean that temperature is a key factor regulating soil trace gas emissions and hydrochemistry. Here we evaluated a novel approach for studying the thermal response of soils, by examining the effects of temperature on gas emissions and hydrochemistry in (a) peat and (b) soil from a Sitka spruce plantation. A thermal gradient was applied along an aluminium bar, allowing soil to be incubated contemporaneously from 2 to 18 °C. The approach demonstrated clear differences in the biogeochemical responses of the two soil types to warming. The peat showed no significant emission of CH₄ at temperatures below 6 °C, while above 6 °C, a marked increase in the rate of release was apparent up to 15 °C (Q₁₀ = 2.5) with emissions being similar between 15 and 18 °C. Conversely, CH₄ emissions from the forest soil did not respond to warming. Nitrate availability in the peat decreased by 90% between 2 and 18 °C (P < 0.01), whereas concentrations in the forest soil did not respond. Sulphate availability in the peat decreased significantly with warming (60%, P < 0.01), while the forest soil showed the opposite response (a 30% increase, P < 0.01). Conventionally, thermal responses are studied by incubating individual soil samples at different temperatures, involving lengthy preparation and facilities to incubate samples at different temperatures simultaneously. Data collected on a given thermal response is usually limited and thus interpolated or extrapolated. The thermal gradient method overcomes these problems, is simple and flexible, and can be adapted for a wide range of sample types (not confined to soil). Such apparatus may prove useful in the optimization of management practices to mitigate the effects of climate change, as thermal responses will differ depending on land use and soil type.     

Osteosarcoma of the distal femur, combined with multiple bone infarcts: the case of a 10-year-old poodle

A ten-year-old female poodle was presented for left hindlimb lameness. Radiographically, irregular intramedullary densities of long bones (bone infarcts) and a lytic lesion in the left distal femur were detected. Two years after the first examination, the lesions in the distal femur were definitely identified as osteosarcoma and the dog was euthanized. Pathological and histological changes of the bone infarcts as well as of the osteosarcoma are described. Regarding bibliographical data, occurrence and aetiopathogenesis of osteosarcoma associated with multifocal bone infarction in man and dog are discussed.     

Economies of Pond Size for Hybrid Striped Bass Growout1

The objective of this study was to evaluate the relationship of pond size and hybrid striped bass growout profitability as an alternative source of farm income in the Mid-Atlantic region. A dynamic, whole farm, Montdarlo capital budgeting simulation model (AQUASIM) and stochastic dominance with respect to a function technique were used to analyze the economics of hybrid striped bass growout from phase II to market production stage for eight farms categorized by pond sizes. Three scenarios are assumed to examine the effects of pond-size dependent changes in feed conversion efficiency and fingerling survival rates on discounted after-tax net present values and probabilities of economic survival and success. Optimal pond sizes were found to be in the 2.5 acre to 10 acre range.     

Evaluation of phagocytic function of canine peripheral polymorphonuclear leucocytes by whole blood chemiluminescence.

Zymosan-induced and luminol-aided chemiluminescence (CL) of whole blood from beagle dogs was estimated for the function of polymorphonuclear leucocytes (PMNs). Whole blood (0.1 ml) was examined directly and results were obtained within 20 min. A phagocytic function of PMNs can be estimated from the peak CL counts and the number of PMNs in a specimen, and the opsonic activity can also be estimated by the peak time showing peak CL after the addition of non-opsonized zymosan. The optimal temperatures to keep diluted whole blood for the CL measurement was around 13 degrees C. Thus, this method offers information concerning the functions of phagocytic cells in whole blood.     

Hematological parameters and visceral lesions relationships in rabbit viral hemorrhagic disease.

Twenty rabbits were inoculated with a suspension of Viral Hemorrhagic Disease virus. Hemostatic functions were assessed every sixth hour from 6 to 60 hours post-inoculation. Tissue samples obtained at the same intervals allowed the study of the development of lesions throughout the experiment. Biological signs of Disseminated Intravascular Coagulation (DIC) were detected on and after 30 h post-inoculation and consisted of prolonged One Stage Prothrombin Time and Activated Partial Thrombin Time, the decrease of factors V, VII, and X and high levels of soluble fibrin monomer complexes and D-dimers. A reduction of thrombocyte numbers, heterophils and lymphocytes was associated. The close association of DIC and necrotizing hepatitis lesions suggested the hepatic lesions to be the most important DIC triggering factor. Other mechanisms are discussed.     

Specificity of the carbon immunoassay (CIA) test for the diagnosis of Toxoplasma infections.

A rapid and low cost procedure, the carbon immunoassay (CIA) test, was evaluated for the diagnosis of Toxoplasma gondii infections. Using a closely related parasite (Besnoitia jellisoni) as antigen, and homologous or heterologous immune sera, it was demonstrated by light and electron microscopy that CIA is a very reliable and specific test. As it is neither expensive nor time-consuming, it can be recommended for general and routine laboratory use.     

Microcirculation in the follicles and corpora lutea of the bovine ovary--a corrosion anatomical study

With the help of a new synthetic material follicles and corpora lutea from the ovaries of 80 cows in different stages of the sexual cycle were examined for modifications of their blood vessel architecture. In the theca externa the main artery which runs towards the follicle, separates into arterioles of which capillaries derive in the theca interna, building a basket-like network around the zona granulosa. After ovulation the follicle wall forms characteristic fields. Capillaries grow into the zona granulosa and thus the folds form the lobular structure of the corpus luteum. Capillaries which rise from the ruptured part of the follicle, spread centripetally and together with lutein cells they build up the not lobulated cupola of the corpus luteum. The regression of the corpus luteum starts around the 16th day of the cycle, beginning at the capillary network of the cupola. A contraction of the vessels and a quick decrease of the volume follow.     

Squamous cell carcinoma of the corneoscleral limbus in a dog.

Squamous cell carcinoma is an uncommon tumor of the cornea in dogs. A 12-year-old Shih Tzu with a history of chronic keratoconjunctivitis sicca was diagnosed as having squamous cell carcinoma of the corneoscleral limbus. The lesion was treated by surgical resection and cryotherapy. One year after surgery, multiple tumors, apparently unrelated to the first tumor, appeared on the same cornea. Keratoconjunctivitis sicca may have predisposed the dog to corneal squamous cell carcinoma development.     

Dietary Lysine Requirement of Juvenile Red Drum Sciaenops ocellatus

The dietary lysine requirement of juvenile red drum Sciaenops ocellatus was reevaluated in two separate experiments. In the first experiment, lyophilized red drum muscle was combined with an L-form crystalline amino acid premix to yield diets containing approximately 35% protein on a dry-matter basis. Gradations (0.25%) of L-lysine HCl were added to the basal diet containing approximately 1.0% lysine. Each diet was fed to triplicate groups of juvenile red drum initially weighing 6–7 g for 8 weeks. Based on growth and feed efficiency data, the lysine requirement (±SE) was determined to be 1.55% (±0.079%) of dry diet or 4.430% of dietary protein. In a second experiment, the lysine requirement of red drum was investigated with diets containing 35% intact protein from zein and red drum muscle. Each of the zein-based diets containing incremental levels of lysine was fed to triplicate groups of juvenile red drum initially weighing 1–2 g for 8 weeks. A crystalline amino acid test diet serving as a control in this experiment significantly outperformed the zein-based diets, and palatability of those diets was questionable due to an obvious change in feeding behavior of the fish. Due to the inferior performance of the fish fed the zein-based diets, the authors were not successful in determining a requirement with these diets. Thus, a lysine requirement of 1.55% of dry diet (4.43% of dietary protein) as determined in the first experiment is recommended for juvenile red drum.     

Isoleucine requirements of the chicken: the effect of excess leucine and valine on the response to isoleucine.

1. Three experiments were designed to determine the response of broiler chickens to dietary isoleucine, and to quantify the antagonistic effects of excess leucine and valine on this response. 2. A dilution technique was used to measure the responses in growth rate and food intake to a range of diets differing in their isoleucine concentrations. A summit diet was formulated to contain isoleucine at 1.14 times the requirement and with leucine (1.76 times the requirement) and valine (1.87 times the requirement) at the minimum possible concentrations, given the ingredients available. A dilution mixture, devoid of protein, was formulated to correspond in all respects, other than in amino acid content, to the summit diet. These two basal diets were blended in different proportions to give a range of diets of decreasing isoleucine and protein content. 3. In experiment 1 the response was measured to isoleucine with leucine and valine remaining in the same proportion to isoleucine throughout the range of diets fed. In experiments 2 and 3, however, L-leucine and L-valine were added to the diets either singly or in combination to give 6 isoleucine concentrations and 3 ratios of each of leucine and valine to isoleucine. 4. Weight gain decreased as the isoleucine content of the diet was reduced, whereas food intake of broilers fed on the marginally deficient diets increased to a maximum and then decreased. FCE decreased curvilinearly as the isoleucine concentration in the food decreased, reflecting a concomitant change in the fat content of the broilers. 5. It is possible that the amount of dietary isoleucine assumed to be available to the broilers in these experiments was overestimated by hydrolysing the food samples for 72 h, and the doubt thus created makes an estimate of the efficiency of retention of isoleucine suspect. 6. Excess valine had no effect on the response to isoleucine, whereas an increase in the leucine to isoleucine ratio depressed food intake and hence weight gain, but only at the lowest concentrations of isoleucine. 7. If the food content of isoleucine is sufficient to meet the requirements of the broiler, relatively large excesses of leucine, of valine, or of both will not depress growth.