Competitive direct enzyme-linked immunosorbent assay for detection of sulfamethazine residues in swine urine and muscle tissue

A sensitive assay for the detection of sulfamethazine in swine urine and muscle tissue using a direct competitive enzyme-linked immunosorbent assay (ELISA) has been developed. Undiluted urine or a phosphate-buffered saline extract of pork muscle tissue is mixed with an enzyme-labeled conjugate of sulfamethazine and horseradish peroxidase. The mixture is added to wells of a microtiter plate coated with antibody to sulfamethazine. After the test system is incubated, washed, and re-incubated with substrate and the reaction is stopped, the absorbance is measured at 405 nm. Levels of sulfamethazine as low as 20 ng sulfamethazine/g muscle tissue and 10 ng sulfamethazine/mL swine urine were detected and estimated.     

Facilitation of sexual behavior in French-Alpine goats treated with intravaginal progesterone-releasing devices and estradiol during the breeding and nonbreeding seasons.

The effectiveness of administering progesterone (P4) using controlled intravaginal drug release (CIDR) devices on estradiol (E2)-induced sexual behaviors was examined in ovariectomized (ovx) French-Alpine goats during the fall and spring. Estradiol-induced attractivity and receptivity were facilitated during the spring when P4-filled CIDR devices were removed 24 or 48 h before injection of 30 microg of E2. During the fall, attractivity was also facilitated by CIDR removal 24 h prior to E2 injection, whereas E2-induced receptivity was unaffected by removal of the CIDR at this interval. Concentrations of P4 in circulation during the 3 d of treatment with a CIDR were similar to those during the late luteal phase of the estrous cycle in intact goats. Treatment with P4-filled CIDR for 3 d, followed by injection with 30 microg of E2 24 h after removal, was determined to be a useful model for inducing sexual behavior in a physiologically relevant manner, and it may also be an effective means for facilitating estrus detection due to the high frequency of display of sexual behavior during a predictable time period following steroid treatment.     

A typology of fisheries management tools: using experience to catalyse greater success

Fisheries provide nutrition and livelihoods for coastal populations, but many fisheries are fully or over‐exploited and we lack an approach for analysing which factors affect management tool performance. We conducted a literature review of 390 studies to assess how fisheries characteristics affected management tool performance across both small‐scale and large‐scale fisheries. We defined success as increased or maintained abundance or biomass, reductions in fishing mortality or improvements in population status. Because the literature only covered a narrow set of biological factors, we also conducted an expert elicitation to create a typology of broader fishery characteristics, enabling conditions and design considerations that affect performance. The literature suggested that the most commonly used management tool in a region was often the most successful, although the scale of success varied. Management tools were more often deemed successful when used in combination, particularly pairings of tools that controlled fishing mortality or effort with spatial management. Examples of successful combinations were the use of catch limits with quotas and limited entry, and marine protected areas with effort restrictions. The most common factors associated with inadequate biological performance were ‘structural’ issues, including poor design or implementation. The expert‐derived typologies revealed strong local leadership, high community involvement and governance capacity as common factors of success across management tool categories (i.e. input, output and technical measures), but the degree of importance varied. Our results are designed to inform selection of appropriate management tools based on empirical data and experience to increase the likelihood of successful fisheries management.     

Gold nanoelectrodes of varied size: transition to molecule-like charging

A transition from metal-like double-layer capacitive charging to redox-like charging was observed in electrochemical ensemble Coulomb staircase experiments on solutions of gold nanoparticles of varied core size. The monodisperse gold nanoparticles are stabilized by short-chain alkanethiolate monolayers and have 8 to 38 kilodaltons core mass (1.1 to 1.9 nanometers in diameter). Larger cores display Coulomb staircase responses consistent with double-layer charging of metal-electrolyte interfaces, whereas smaller core nanoparticles exhibit redox chemical character, including a large central gap. The change in behavior is consistent with new near-infrared spectroscopic data showing an emerging gap between the highest occupied and lowest unoccupied orbitals of 0.4 to 0.9 electron volt.     

A review of 14 cases of hypertrophic osteopathy (Marie's disease) in horses in the Republic of Ireland

There are few reports describing hypertrophic osteopathy (HO) in horses and no reports describing this in the Irish equine population. This case series outlines the clinical, radiological and pathological features of HO in horses in Ireland and compares and contrasts the findings to previous reports. Overall, the prevalence of HO in Irish horses was found to be low with clinical signs similar to previous reports. Diagnosis of the primary lesion was low, largely due to the limited diagnostic evaluation in a large proportion of the horses evaluated. The horses had a low average age and a high prevalence (35.5%) of mandibular and facial involvement.