Histopathological investigation of four populations of abalone (Haliotis iris) exhibiting divergent growth performance.

The black-foot abalone (paua), Haliotis iris, is a unique and valuable species to New Zealand with cultural importance for Maori. Abalone are marine gastropods that can display a high level of phenotypic variation, including slow-growing or 'stunted' variants. This investigation focused on identifying factors that are associated with growth performance, with particular interest in the slow-growing variants. Tissue alterations in H. iris were examined using histopathological techniques, in relation to growth performance, contrasting populations classified by commercial harvesters as 'stunted' (i.e., slow-growing) and 'non-stunted' (i.e., fast-growing) from four sites around the Chatham Islands (New Zealand). Ten adults and 10 sub-adults were collected from each of the four sites and prepared for histological assessment of condition, tissue alterations, presence of food and presence of parasites. The gut epithelium connective tissue, digestive gland, gill lamellae and right kidney tissues all displayed signs of structural differences between the slow-growing and fast-growing populations. Overall, several factors appear to be correlated to growth performance. The individuals from slow-growing populations were observed to have more degraded macroalgal fragments in the midgut, increased numbers of ceroid granules in multiple tissues, as well as increased prevalence of birefringent mineral crystals and haplosporidian-like parasites in the right kidney. The histopathological approaches presented here complement anecdotal field observations of reduced seaweed availability and increased sand incursion at slow-growing sites, while providing an insight into the health of individual abalone and sub-populations. The approaches described here will ultimately help elucidate the drivers behind variable growth performance which, in turn, supports fisheries management decisions and future surveillance programs.

Machine Learning Methods and Visual Observations to Categorize Behavior of Grazing Cattle Using Accelerometer Signals.

Accelerometers worn by animals produce distinct behavioral signatures, which can be classified accurately using machine learning methods such as random forest decision trees. The objective of this study was to identify accelerometer signal separation among parsimonious behaviors. We achieved this objective by (1) describing functional differences in accelerometer signals among discrete behaviors, (2) identifying the optimal window size for signal pre-processing, and (3) demonstrating the number of observations required to achieve the desired level of model accuracy,. Crossbred steers (Bos taurus indicus; n = 10) were fitted with GPS collars containing a video camera and tri-axial accelerometers (read-rate = 40 Hz). Distinct behaviors from accelerometer signals, particularly for grazing, were apparent because of the head-down posture. Increasing the smoothing window size to 10 s improved classification accuracy (p < 0.05), but reducing the number of observations below 50% resulted in a decrease in accuracy for all behaviors (p < 0.05). In-pasture observation increased accuracy and precision (0.05 and 0.08 percent, respectively) compared with animal-borne collar video observations.

British societies guideline on the management of emergencies in implantable left ventricular assist device recipients in transplant centres.

An implantable left ventricular assist device (LVAD) is indicated as a bridge to transplantation or recovery in the United Kingdom (UK). The mechanism of action of the LVAD results in a unique state of haemodynamic stability with diminished arterial pulsatility. The clinical assessment of an LVAD recipient can be challenging because non-invasive blood pressure, pulse and oxygen saturation measurements may be hard to obtain. As a result of this unusual situation and complex interplay between the device and the native circulation, resuscitation of LVAD recipients requires bespoke guidelines. Through collaboration with key UK stakeholders, we assessed the current evidence base and developed guidelines for the recognition of clinical deterioration, inadequate circulation and time-critical interventions. Such guidelines, intended for use in transplant centres, are designed to be deployed by those providing immediate care of LVAD patients under conditions of precipitous clinical deterioration. In summary, the Joint British Societies and Transplant Centres LVAD Working Group present the UK guideline on management of emergencies in implantable LVAD recipients for use in advanced heart failure centres. These recommendations have been made with a UK resuscitation focus but are widely applicable to professionals regularly managing patients with implantable LVADs.