Abundant PrP(CWD) in tonsil from mule deer with preclinical chronic wasting disease.

A monoclonal antibody dot-blot assay was used to evaluate detergent lysates of tonsil tissue from mule deer to detect PrP(CWD), the marker for the cervid transmissible spongiform encephalopathy chronic wasting disease (CWD). Samples of formalin-fixed brain and tonsil tissues from mule deer were examined for PrP(CWD) using immunohistochemistry (IHC) with Mab F99/97.6.1, the gold standard for diagnosis of preclinical CWD. The contralateral tonsil from each of the 143 deer was prepared for confirmatory IHC and as a 10% (wt/vol) detergent lysate without purification or enrichment steps for monoclonal antibody dot-blot assay. PrP(CWD) was detected by dot-blot assay in 49 of 50 samples considered positive by IHC. Forty-eight of the positive samples were evaluated with a quantitative dot-blot assay calibrated with recombinant PrP. Tonsillar PrP(CWD) concentrations ranged from 34 to 1,188 ng per 0.5 mg starting wet weight of tissue. The abundant PrP(CWD) in mule deer tonsil will facilitate development and validation of high-throughput screening tests for CWD in large populations of free-ranging deer.     

Stability in reproductive timing and habitat usage of Chinook salmon across six years of varying environmental conditions and abundance

The spatial and temporal distribution of spawning activity by autumn‐run Chinook salmon Oncorhynchus tshawytscha (Walbaum) was examined across multiple years. The study period included two years of extreme drought conditions when water temperatures in the spawning reach of the Stanislaus River were considered sub‐optimal for spawning and egg incubation. Despite varying levels of superimposition, redd counts and densities remained stable and positively associated with river location, indicating that superimposition may be driven by habitat preference rather than the absence of suitable spawning locations. Spawning occurred slightly later during drought years (6–10 days later compared with wetter years). This delay was attributable to deferred migration instead of deferred spawning, and the majority of redds were constructed at water temperatures exceeding the optimal temperature range. As a consequence, estimates of juvenile production during 2014 and 2015 were among the lowest on record. These findings may be related in part to the high hatchery contribution to the population, above‐average temperatures during spawning and incubation, and superimposition rates. Management recommendations include adequate cold‐water storage in the upstream reservoir, refined spawning habitat restoration techniques in the light of superimposition rates and, on a broader system scale, actions that reduce the amount of stray hatchery Chinook salmon.     

Global occurrence and spread of highly pathogenic avian influenza virus of the subtype H5N1

Highly pathogenic avian influenza viruses of the subtype H5N1 (HPAIV-H5N1) have circulated continuously in Asia, Europe, and Africa since 2003. Investigations on the environmental preference and global spread processes of the virus are needed. We compiled 16 environmental variables to assess their correlation with HPAIV-H5N1 occurrences by using a niche-based model called Maxent. We found the virus had the strongest positive association with the human footprint index, as well as the presence of certain types of wetlands and mild temperature (10-30 C). Outbreaks of HPAIV-H5N1 in poultry or wild birds were also more frequent in certain major habitat types (e.g., tropical and subtropical moist broadleaf forests, temperate broadleaf and mixed forests, and flooded grasslands and savannas) and ecoregions. We conducted trend surface analysis to generate the travelling wave of the virus' global spread from 2003 to 2009, which indicated that high mountains or plateaus did not affect the spread speed and direction.     

The impact of phages on interspecific competition in experimental populations of bacteria

Background  

Phages are thought to play a crucial role in the maintenance of diversity in natural bacterial communities. Theory suggests that phages impose density dependent regulation on bacterial populations, preventing competitive dominants from excluding less competitive species. To test this, we constructed experimental communities containing two bacterial species (Pseudomonas fluorescens and Pseudomonas aeruginosa) and their phage parasites. Communities were propagated at two environmental temperatures that reversed the outcome of competition in the absence of phage.     

Theoretical and Empirical Relationships Between Oat Test Weight and Groat Proportion

Test weight and groat proportion are two very important quality characteristics of oat grain. In this study, we pose the hypothesis that these two characteristics are related through characteristics of grain density. Test weight is defined as the product of kernel density and packing proportion. Groat proportion, in theory, is the ratio of the groat mass to the kernel mass. We present two theoretical constructions expressing test weight in terms of groat proportion, packing proportion and kernel density components. To test these, we have applied measurements of test weight, groat proportion, kernel density components, and packing proportion of 18 oat cultivars grown at six environments. Whereas the groat proportion alone accounted for only 34% of the variation in test weight, our theoretical constructions that included groat proportion could account for ≤82% of variation in test weight. Also, we present previously undescribed variation in oat kernel density components across genotypes and environments. Although the kernel density alone could account for most of the variation in test weight across genotypes, packing proportion appeared to be more important in describing variation in test weight of a genotype across different environments. We observed significant variation in both groat and hull density which, together with groat proportion, described most of the variation in kernel density.     

Evaluating a group-based intervention to improve the safety of meat in Bodija Market,Ibadan, Nigeria

We evaluated a group-based, participatory training intervention to improve food safety among meat processors and retailers in Bodija Market, Ibadan, Nigeria. An interactive training workshop was held for Butchers Associations’ representatives who were selected to pass on information and training to their group. Meat hygiene knowledge, attitude and practice was assessed before attending the workshop and afterwards (n = 63). It was also assessed for those who did not attend the workshop (n = 68) but were intended recipients of training through their association. Microbiological quality of meat was assessed before and after the workshop (n = 400 samples). After the workshop, participants significantly improved knowledge, attitude and practice in key food safety aspects; specifically, understanding sources of contamination and food-borne diseases, use of bleach and disinfectant and hand washing. Participants also shared information with an average of 18 other group members and improvements were seen in group members who did not attend the workshop but received training through their Butchers Association. Microbiological quality of meat sold also significantly improved after the intervention. In conclusion, participatory, group-based methods targeted at meat processors and retailers can improve meat hygiene knowledge, attitude and practice as well as the microbiological quality and hence safety of meat.

     

Identification of a novel hemotropic mycoplasma in a splenectomized dog with hemic neoplasia

A 3-year-old sexually intact male Bull Mastiff underwent splenectomy for splenic thrombosis; prior to and after splenectomy, multiple blood transfusions were administered. Two weeks after the procedure, T-cell lymphoproliferative disease was diagnosed. Treatment with prednisone and chlorambucil was initiated, and 2 weeks later, cytologic examination of a blood smear revealed small (0.3 microm), coccoid basophilic bodies on the surface of approximately 70% of the RBCs. Morphologically, these resembled "Candidatus Mycoplasma haemominutum." A polymerase chain reaction assay was used to amplify a partial 16S rRNA sequence in blood obtained from the dog; the product was sequenced and compared with 16S rRNA gene sequences of other hemotropic mycoplasmas. The sequence was 98% homologous to that of "Candidatus M haemominutum", but only 77% homologous to that of M haemocanis and M haemofelis.     

Quantitative study of pulmonary endocrine cells in fetal, postnatal and adult sheep

Using light microscopic immunohistochemistry, neuron-specific enolase (NSE)-positive endocrine cells were quantitatively analyzed in the sheep lung during different stages of development from the canalicular stages to adulthood. In all stages, NSE-positive endocrine cells were usually located in the bronchi and bronchioles as solitary cells, although a few NSE-positive cell clusters, the so-called neuroepithelial bodies, were found in some places. The number of NSE-positive endocrine cells decreased with advanced stages of gestation. In the late alveolar stage, the number of NSE-positive endocrine cells reached its bottom during the fetal period. There was a gradual upturn after birth. The overall pattern of growth and differentiation of the endocrine cells is most likely species-related and depends on the state of airway development; the number of the endocrine cells of almost all animals, excluding the sheep, in relation to the size of the lung reaches a peak in the late fetal and early neonatal periods and decreases shortly thereafter. NSE-positive endocrine cells were also predominantly located in the large airways during the early stage of development (canalicular stage), and were found more frequently in the small peripheral airways towards the term. These results show the number of NSE-positive endocrine cells in the sheep to be different from that seen in other species.