"Lumpy jaw" in exotic hoof stock: a histopathologic interpretation with a treatment proposal.

"Lumpy jaw" of artiodactyls and macropods, although often considered a manifestation of actinomycosis, is actually an osteomyelitis, perhaps commencing with a dental root abscess or trauma to the jaw. Anaerobes may be cultured from the lesions, and vegetable matter may be impacted in them. It is a chronic disease and difficult to treat. Successful treatment may include draining the abscess, cleaning the cavity with saline and antibiotics, flushing with a combination of hydrogen peroxide-sodium hypochlorite and Betadine, and apicoectomy and endodontic filling when active inflammation has subsided.     

Mechanism-based diagnostic reasoning: thoughts on teaching introductory clinical pathology

Abstract: Teaching introductory clinical pathology to veterinary students is a challenging endeavor that requires a shift in learning strategies from rote memorization to diagnostic reasoning. Educational research has identified discrete cognitive stages required to achieve the automated, unconscious thinking process used by experts. Building on this knowledge, we developed a case-based approach to clinical pathology instruction that actively engages students in the learning process and links performance with positive reward. Simulated cases provide context and create a structure, or "schema", which enhances the learning process by enabling students to synthesize facts and link them with their causal mechanism to reach a defensible diagnostic conclusion. Web-based tools, including the "Problem List Generator" and tutorials, have been developed to facilitate this process. Through the collaborative Biomedical Informatics Research Group, we are working to further develop and evaluate Web-based instructional tools and new educational methods, to clarify the diagnostic reasoning processes used by experienced clinical pathologists, and, ultimately, to better educate our future students to be effective diagnosticians.     

A neurophysiological study of DDT-pyrethroid isosteres on the labellar hair receptor of Lucilia cuprina

A novel group of oxime O-ether insecticides was tested on the labellar taste receptors of the blowfly Lucilia cuprina. Some of the compounds failed to elicit any response at the receptor, while the neurophysiologically active compounds generated multiple nerve spikes similar to DDT. The insect toxicities of all the oxime O-ethers were tested by topical application on the same strain of blowfly. The relationships between structure, index of multiplicity and LD₅₀ values are discussed.     

Distribution of glyphosate-resistant and glyphosate-susceptible hairy fleabane (Conyza bonariensis) in central California and their phenological development

Glyphosate-resistant (GR) hairy fleabane was first documented in California in 2007. A preliminary study comparing plants from this population to a glyphosate-susceptible (GS) population determined that they developed more rapidly than the GS plants. However, it was not known if this was a general characteristic of all GR populations. Therefore, seeds of hairy fleabane were collected from 122 locations in central California. Plants from each location were grown and tested for resistance using a shikimate enzyme assay. Seeds from 90 locations germinated of which 27 % were determined as GR, 21 % as GS, and 52 % as intermediate/mixed. Plants from five GR and five GS populations, as determined by the assay, were randomly selected for comparisons and were grown in 2010/2011. Time taken by each plant to reach key phenological stages was recorded and converted into growing degree day (GDD) using a base temperature of 4.2 °C. The biomass of each plant was recorded at seed set. The five GR and GS plants had similar phenological development rates and biomass. Therefore, the differences previously identified between the two populations were not present in the additionally tested populations. The phenological development was hence described by a common GDD model with the plants requiring 374, 711, 970, 1289, and 1551 GDD, to reach the rosette, bolting, first bud, first flower, and first seed stages, respectively. This study shows widespread distribution of GR hairy fleabane in central California, provides useful information on biology of this weed for management, and suggests possible label changes to herbicide manufacturers.     

Recovery and dynamics of a primary tropical dry forest in Jamaica, 10 years after human disturbance

Changes in forest structure, the rate of recovery and stem turnover, 10 years after experimental cutting of a primary tropical dry forest in Jamaica, were determined by conducting a post-disturbance inventory of permanent sample plots in 2009. In April 1999, two plots within each of four blocks were assigned to two randomly allocated treatments (partially and clear cut) and a plot was assigned as a control (uncut). The treatment intensities were intended to mimic wood extraction for charcoal or timber production, a common form of anthropogenic disturbance in Caribbean dry forests. The application of the treatments significantly reduced the number of trees per diameter size-class, but after 10 years, the size-class distribution for the small size-classes was similar to pre-disturbance measurements. However, larger size-classes (?14 cm) in 2009 had fewer individuals when compared with the pre-disturbance size-class distribution. Ten years after cutting, tree height, basal area and tree density in partially cut plots had recovered by 92%, 81% and 94% and in clear cut plots by 78%, 35% and 78% respectively, in comparison with control plots. Although the biomass lost due to cutting and the original state of this forest have not fully recovered 10 years after disturbance, our results showed that coppicing allows the establishment of some semblance of a canopy and offers a rapid route to reclaim space. This newly established canopy also helps to ameliorate environmental conditions facilitating regeneration by seed, which would otherwise take years to occur due to the harsh conditions found in open areas. No new species or any species that could be described as pioneers were recorded and despite a shift in dominance, secondary succession did not occur. Therefore gap dynamics, often used to describe the process of regeneration in tropical rainforests, cannot be used to describe regeneration in this dry forest ecosystem.