New heterocyclic herbicidal sulphonamides

The sulphonylurea structures and their relationships with the 1,2,4-triazolo[1,5-a]pyrimidinesulphonamides are first discussed. Three novel examples of heterocyclic sulphonamides, pyrazolo[1,5-a]pyrimidine-2-sulphonamides, thiazolo[3,2-b][1,2,4]triazole-2-sulphonamides and 1,2,4-triazole-3-sulphonamides are highlighted and their synthesis, biological activity and soil behaviour are described.     

The pathology of Flexibacter maritimus in aquaculture species in Tasmania, Australia

Macroscopic and microscopic features of natural and experimental Flexibacter maritimus infection, and epidemiological aspects of the disease, have been reported in a number of species of fish in Tasmanian aquaculture including Atlantic salmon, Salmo salar L., rainbow trout, Oncorhynchus mykiss (Walbaum), greenback flounder, Rhombosolea tapirina Günther, and striped trumpeter, Latris lineata (Bloch & Schneider). There is a great deal of consistency in the pathology in salmonids and non-salmonid species, with erosive lesions of external surfaces being the most prominent clinical sign. Experimentally induced disease of salmonids and flounder is similar to natural infection. Mature lesions show dermal and gill erosion, with dermal bacterial invasion into the dense connective tissue and occasionally underlying musculature, but a remarkable lack of inflammatory response. The earliest lesions show consistent fragmentation and degeneration of the epithelium, with infiltration of amorphous protein-like materials and occasionally intra-epithelial cellular inflammatory cells, plus congestion and haemorrhage of the superficial dermis, but without visible bacteria in standard sections. Variable scale loss, oedema and a low level of inflammation in scale pockets, plus variable small adherent bacterial mats, are evident before full epithelial erosion.     

Formation of a Reservoir of Sperm in the Oviduct

A reservoir of sperm in the initial segment of the oviduct has been found in several species of domestic and laboratory mammals. Evidently, the reservoir serves to ensure successful fertilization by providing the appropriate number of sperm in the appropriate physiological state for fertilizing oocytes soon after they enter the oviduct. Recent evidence indicates that sperm are trapped in the reservoir by binding to specific carbohydrate moieties on the surface of the mucosal epithelium of the oviduct. A bovine seminal plasma protein has been identified that associates with sperm and confers on them the capacity to bind to the carbohydrate moiety.     

Estimating the level of disease risk and biosecurity on commercial poultry farms in New Zealand

ABSTRACT

Aims: To collect baseline data on the contact risk pathways and biosecurity practices of commercial poultry farms in New Zealand, investigate the relationship between the farm-level disease contact risks and biosecurity practices, and identify important poultry health concerns of producers.

Methods: A cross-sectional survey of all registered New Zealand commercial poultry operations was conducted in 2016 collecting information on farm demographics, biosecurity practices, and contact risk pathways. Survey responses were used to generate an unweighted subjective disease risk score based on eight risk criteria and a subjective biosecurity score based on the frequency with which producers reported implementing seven biosecurity measures. Producer opinions towards poultry health issues were also determined.

Results: Responses to the survey response were obtained from 120/414 (29.0%) producers, including 57/157 (36.3%) broiler, 33/169 (19.5%) layer, 24/55 (44%) breeder, and 6/32 (19%) other poultry production types. Median disease risk scores differed between production types (p?<?0.001) and were lowest for breeder enterprises. The greatest risk for layer and broiler enterprises was from the potential movement of employees between sheds, and for breeder enterprises was the on- and off-farm movement of goods and services. Median biosecurity scores also differed between production types (p?<?0.001), and were highest for breeder and broiler enterprises. Across all sectors there was no statistical correlation between biosecurity scores and disease risk scores. Producers showed a high level of concern over effectively managing biosecurity measures.

Conclusions: The uptake of biosecurity measures in the commercial poultry farms surveyed was highly variable, with some having very low scores despite significant potential disease contact risks. This may be related to the low prevalence or absence of many important infectious poultry diseases in New Zealand leading farmers to believe there is a limited need to maintain good biosecurity as well as farmer uncertainty around the efficacy of different biosecurity measures. Further research is needed to understand barriers towards biosecurity adoption including evaluating the cost-effectiveness of biosecurity interventions.     

Biofilms and their relevance to veterinary medicine

Bacteria are renowned for their ability to tolerate and adapt to a wide range of adverse environmental conditions. The primary mechanism that facilitates these adaptations is thought to be the capacity to form and maintain biofilms. Within a biofilm, bacteria become attached to a surface where they exist in complex communities which are able to interact with each other through intracellular communication and thus rapidly adapt to changing environments. The organisms within biofilms are notorious for their resistance towards the host immune response and antibacterial agents compared to their free-living planktonic counterparts. Consequently, biofilms are of significant importance to both clinical and veterinary science. However, although bacterial infections are widely reported in animals their association with biofilms is rarely discussed. The aim of this review is to look at the characteristics of biofilm infections in humans and to relate this knowledge to veterinary science in order to assess their relevance in this area.     

An improved method for determining the specific surface areas of topsoils with varied organic matter content, texture and clay mineral composition

Measuring the specific surface area (SSA) of soils that contain much organic matter (OM) is problematic. The adsorption of p-nitrophenol (pNP) from xylene at room temperature yielded realistic values for the SSA of a wide range of clays, oxides and subsoils. Here we have extended the same measurement to some topsoils with varied OM content, texture and clay mineral composition. Specifically, we have compared the surface areas measured by adsorption of N₂, and, applying the BET equation, with the values obtained by adsorption of pNP, before and after treatment of the samples with hydrogen peroxide. In all instances, the removal by H₂O₂ of organic matter – albeit in part only – led to a marked increase in the SSAs measured by nitrogen because of the exposure of micropores previously blocked or covered by OM. The surface areas measured by pNP were appreciably larger than those obtained by the standard BET equation, and showed little change after removal of organic matter. However, the surface area of two smectite-rich samples measured by pNP increased substantially after peroxidation, presumably because smectite crystals decomposed during treatment with H₂O₂. The results suggest that, under the experimental conditions used, pNP could diffuse without hindrance into and through organic matter, enabling it to adsorb on to micropore surfaces within clay aggregates (domains). In keeping with this suggestion, the relation between the surface areas measured by pNP and the corresponding values calculated from the clay and OM contents, and clay mineral composition, of the soils was close to 1:1. An even stronger relation was observed between the measured and calculated values for cation exchange capacity.     

Laboratory and field susceptibility of blueberry spanworm (Lepidoptera: Geometridae) to conventional and reduced-risk insecticides

Blueberry spanworm (Itame argillacearia Packard) is a key insect defoliator of wild blueberry, an important crop in north-eastern North America. We evaluated the susceptibility of blueberry spanworm to several reduced-risk insecticides in laboratory and field experiments. Two populations from two Canadian provinces were studied in the laboratory. Both were highly susceptible to flubendiamide, spinetoram and deltamethrin, although there were inter-population differences, and flubendiamide was slower acting. Flubendiamide, spinosad, spinetoram, and methoxyfenozide demonstrated good suppression of economically damaging populations of blueberry spanworm larvae in the field.