Skin layer thickness at the ear of the domesticated pig,with special reference to the use of the ear integument for human dermatological research

Based on a shrinkage-free methodical approach (special plastic resin embedding, frozen section technique) and histological routine staining, the thickness of the different skin layers was measured from 15 regions of the outer and the inner side of the porcine auricle. Mean thickness values were for the str. corneum: 19 microns outside/20 microns inside, vital epidermis without ridges: 52 microns outside/56 microns inside, dermis: 1175 microns outside/1112 microns inside, hypodermis: 1024 microns outside/741 microns inside, perichondrium: 295 microns outside/220 microns inside. When both sides of the auricle were compared, it became obvious that the outer side generally had a thicker dermis (1140-1290 microns) and hypodermis (780-1150 microns), whereas the inner side had a thicker vital epidermis (50-60 microns) and deeper epidermal ridges (145-165 microns). The results are discussed with regard to corresponding findings from the human skin, and one region of the outer side of the porcine auricle is recommended as suitable for human dermatological research.     

The antifouling activity of some juvenoids on three species of acorn barnacle, Balanus

Analogues of insect juvenile hormones (juvenoids) have been tested for settling inhibition of cyprids from three species of barnacle, Balanus balanoides (L.), Balanus improvisus Darwin and Balanus amphitrite Darwin. Some 3-alkoxypyridine derivatives exhibited strong activity at mg litre(-1) concentrations; 3,7-dimethyloctyl 2-methyl-5-pyridyl ether (8) gave an EC(50) of 0.006 mg litre(-1) when tested on B. balanoides. When compound 8 and similar juvenoids were incorporated into paints, test panels kept in seawater for 8 months were free of barnacles.     

A coherent signature of anthropogenic nitrogen deposition to remote watersheds of the Northern Hemisphere

Humans have more than doubled the amount of reactive nitrogen (Nr) added to the biosphere, yet most of what is known about its accumulation and ecological effects is derived from studies of heavily populated regions. Nitrogen (N) stable isotope ratios ((15)N:(14)N) in dated sediments from 25 remote Northern Hemisphere lakes show a coherent signal of an isotopically distinct source of N to ecosystems beginning in 1895 ± 10 years (±1 standard deviation). Initial shifts in N isotope composition recorded in lake sediments coincide with anthropogenic CO(2) emissions but accelerate with widespread industrial Nr production during the past half century. Although current atmospheric Nr deposition rates in remote regions are relatively low, anthropogenic N has probably influenced watershed N budgets across the Northern Hemisphere for over a century.     

Summary receiver operating characteristics (SROC) and hierarchical SROC models for analysis of diagnostic test evaluations of antibody ELISAs for paratuberculosis

Critical, systematic reviews of available diagnostic test evaluations are a meticulous approach to synthesize evidence about a diagnostic test. However, often the review finds that data quality is poor due to deficiencies in design and reporting of the test evaluations and formal statistical comparisons are discouraged. Even when only simple summary measures are appropriate, the strong correlation between sensitivity and specificity and their dependence on differences in diagnostic threshold across studies, creates the need for tools to summarise properties of the diagnostic test under investigation.This study presents summary receiver operating characteristics (SROC) analysis as a means to synthesize information from diagnostic test evaluation studies. Using data from a review of diagnostic tests for ante mortem diagnosis of paratuberculosis as an illustration, SROC and hierarchical SROC (HSROC) analysis were used to estimate overall diagnostic accuracies of antibody ELISAs for bovine paratuberculosis while accounting for covariates: the target condition (infectious or infected) used in the test evaluation (one for the evaluation of Se and one for Sp); and the type of test (serum vs. milk). The methods gave comparable results (regarding the estimated diagnostic log odds ratio), considering the small sample size and the quality of data. The SROC analysis found a difference in the performance of tests when the target condition for evaluation of Se was infected rather than infectious, suggesting that ELISAs are not suitable for detecting infected cattle. However, the SROC model does not take differences in sample size between study units into account, whereas the HSROC allows for both between and within study variation. Considering the small sample size, more credibility should be given to the results of the HSROC. For both methods the area under the (H)SROC curve was calculated and results were comparable.The conclusion is that while the SROC is simpler and easier to implement, analyse and interpret, the HSROC does have properties encourage the extra effort involved in the analysis.     

Development of a Rapid LC-UV Method for the Investigation of Chemical and Metabolic Stability of Resveratrol Oligomers

Resveratrol, piceatannol, ε-viniferin, r-viniferin, r2-viniferin, and hopeaphenol are naturally occurring polyphenols, associated with potentially beneficial health effects. We developed a rapid liquid chromatography-ultraviolet detection (LC-UV) method, allowing for the simultaneous determination of these six compounds in biological samples in less than 2.5 min with standard LC equipment. Using this method for the assessment of the stability of the six analytes, we demonstrated that all stilbene polyphenols disappear rapidly in Dulbecco's modified Eagle's medium (e.g., half-life of resveratrol of 1 h). In contrast, the tetramer hopeaphenol was stable over the maximum incubation time of 72 h. In incubations with liver microsomes, ε-viniferin was rapidly glucuronidated, although to a lower extent than resveratrol. Hopeaphenol was not glucuronidated at all. Given that glucuronidation is the major metabolic pathway for polyphenols, hopeaphenol might exhibit significantly different pharmacokinetic properties than other polyphenols. When chemical and metabolic stability as well as biological activity of hopeaphenol are taken together, these findings warrant further investigation of this polyphenol.     

Evaluation of two herd-level diagnostic tests for Streptococcus agalactiae using a latent class approach

Streptococcus agalactiae mastitis persists as a significant economic problem for the dairy industry in many countries. In Denmark, the annual surveillance programme for this mastitis pathogen initially based only on bacteriological culture of bulk tank milk (BTM) samples, has recently incorporated the use of the real-time PathoProof Mastitis PCR assay with the goal of improving detection of infected herds. The objective of our study was to estimate the herd sensitivity (Se) and specificity (Sp) of both tests of BTM samples using latent class models in a Bayesian analysis while evaluating the effect of herd-level covariates on the Se and Sp of the tests. BTM samples were collected from all 4258 Danish dairy herds in 2009 and screened for the presence of S. agalactiae using both tests. The highest Se of PCR was realized at a cycle threshold (Ct) cut-off value of 40. At this cut-off, the Se of the PCR was significantly higher (95.2; 95% posterior credibility interval [PCI] [88.2; 99.8]) than that of bacteriological culture (68.0; 95% PCI [55.1; 90.0]). However, culture had higher Sp (99.7; 95% PCI [99.3; 100.0]) compared to PCR (98.8; 95% PCI [97.2; 99.9]). The accuracy of the tests was unaffected by the herd-level covariates. We propose that screenings of BTM samples for S. agalactiae be based on the PCR assay with Ct readings of <40 considered as positive. However, for higher Ct values, confirmation of PCR test positive herds by bacteriological culture is advisable especially when the between-herd prevalence of S. agalactiae is low.     

Household Dynamics of Wildlife Value Orientations

Wildlife value orientations (WVOs) shape attitudes and behavior toward wildlife. Although demographic correlates of WVOs are well established, these relationships are largely unknown among children and within family units. The only previous study addressing these topics used fathers’ perceptions as proxies for family member WVOs. We surveyed North Carolina households (n = 136) to test hypotheses regarding whether individuals can assess household WVOs and what variables shape WVOs within households. Fathers and mothers accurately assessed WVOs of their children. Membership in a household was the most important predictor of an individual’s WVOs (accounting for 37% [ρ = .37] of the variance predicted by the model). Younger age, being female, and lack of participation in hunting were associated with more protectionist WVOs. These results provide the first household level support for divergence between generations from utilitarian toward protectionist WVOs. Our results suggest that household unit may be a critical element to consider in WVO research.     

Fractionation of Soluble Molybdenum-Binding Proteins from Liver,Kidney, Plasma and Erythrocytes from Sheep Supplemented with Molybdenum

Five ewes were given a daily dose of 1.4 mg Mo/kg body weight as ammonium molybdate for 21 to 55 days. Plasma molybdenum concentrations increased considerably following the dosage, but no systematic changes were seen in the plasma copper concentrations. About 80 % of the molybdenum present in blood was found in plasma. With gel filtration it was shown that practically all of the molybdenum present in plasma and red cell haemolyzates was found in a fraction with molecular weight less than 1,500. Soluble proteins from liver and kidney cortex were separated into one high molecular weight fraction with molecular weight above 200,000 and a non-protein fraction with molecular weight less than 1,500. Significant correlations were found between the amounts of molybdenum present in the high molecular weight fraction and the molybdenum concentrations in liver and kidney.     

Nitrogen release from different polymer-coated urea fertilizers in soil is affected by soil properties

The use of urea as nitrogen (N) fertilizer in agriculture needs to consider environmental, economic and resource conservation aspects because of low N-use efficiency (NUE). Polymer-coated urea (PCU) offers an effective way to improve the NUE of urea and to reduce its environmental trade-offs. However, we lack information on the impact of climate and soil properties on N release from PCU. Therefore, this study was performed to quantify the effects of soil texture, moisture and temperature on the release kinetics of N from PCU. We designed a test system for soil incubation experiments and investigated three fertilizers with different release patterns, five topsoils, three moisture levels and two temperatures over 48 days. We analysed the concentrations of inorganic N (${\mathrm{NH}}_4^{+}-\mathrm{N}$ and ${\mathrm{NO}}_3^{-}-\mathrm{N}$) in the soil and estimated N release rates using the unified Richards model. Soil texture did not change the N release patterns, but release rates varied significantly among the investigated soils. Changes in soil moisture for a given soil had no effect on N release from PCU and urea when fertilizers were incorporated into the soil at conditions supportive of crop growth. Lowering soil temperatures, however, decreased N release rates from PCU by 16%–49% but only in silt loam and not in sandy loam. We conclude that PCU improves the N residence time in soil, but predictions on N release from PCU must be adapted to the prevailing environmental conditions and cannot be generalized across differently textured soils.