dSarm/Sarm1 is required for activation of an injury-induced axon death pathway

Axonal and synaptic degeneration is a hallmark of peripheral neuropathy, brain injury, and neurodegenerative disease. Axonal degeneration has been proposed to be mediated by an active autodestruction program, akin to apoptotic cell death; however, loss-of-function mutations capable of potently blocking axon self-destruction have not been described. Here, we show that loss of the Drosophila Toll receptor adaptor dSarm (sterile α/Armadillo/Toll-Interleukin receptor homology domain protein) cell-autonomously suppresses Wallerian degeneration for weeks after axotomy. Severed mouse Sarm1 null axons exhibit remarkable long-term survival both in vivo and in vitro, indicating that Sarm1 prodegenerative signaling is conserved in mammals. Our results provide direct evidence that axons actively promote their own destruction after injury and identify dSarm/Sarm1 as a member of an ancient axon death signaling pathway.     

Manipulation of parasitoids for aphid pest management: progress and prospects

This paper describes research at IACR-Rothamsted on aphid parasitoid responses to semiochemical foraging stimuli, aimed at developing novel ways of manipulating these behaviours to overcome ecological constraints to biological and integrated pest control. Female parasitoids respond both to aphid sex pheromones acting as kairomones, and to aphid-induced plant volatiles, acting as synomones. A range of economically important parasitoid species respond to aphid sex pheromones, and their potential for enhancing parasitization of aphid populations has been demonstrated in the field. Commercial production of the pheromone from the plant Nepeta cataria L has been developed and strategies for its use in arable crops are being investigated. Aphid-induced plant volatiles are released systemically throughout the plant and are aphid species specific, probably induced by elicitors in aphid saliva. Aphid-infested plants can induce uninfested neighbours to release damage-related volatiles, plant-to-plant communication occurring via the rhizosphere. The plant compound cis-jasmone has been identified as a plant signal with potential for aphid control, inducing plant defence mechanisms that both deter colonising aphids and attract parasitoids and predators. Such compounds may represent a new generation of crop protectants and their further investigation and development will be aided by the tools generated by genomic and post-genomic biology.     

A legacy of competing imperatives: Environment and development in australia since 1788

Australia's environments have been dramatically transformed by immigrant communities who were impelled by a simple utilitarian dream and obliged by geographical and historical circumstance to contend with accumulating uncertainties, including those connected with the operation of Nature's own independent dynamic. With the exception of a few critical junctures and significant but highly localized settings which are reasonably well supplied with primary material, the historical records are scarcely satisfactory for fine-textured reconstructions of changing physical landscapes. There is certainly some potential for very broad ‘indicative’ stocktaking, but unavoidable imprecisions and the irritating problem of discontinuities rule out the most ambitious of International Geosphere-Biosphere Programme (IGBP) style studies. Therefore a major premise of this discussion is the acceptance that we are obviously better placed to offer a range of underpinning social, political and economic analyses than to launch into the production of confident, large-scale reconstructions of the past ‘faces’ of Australia. The bulk of this paper explores that proposition and is confined to such analyses. On the other hand, it also suggests that the time is ripe for tailoring novel co-operative research into landscape change in the ‘European’ era, especially by combining physical and documentary evidence in the investigation of carefully selected sites and situations.     

A Rertrospective Analysis of Pulmonary Contusion Secondary to Motor Vehicular Accidents in 143 Dogs: 1994 - 1997

Medical records of 143 dogs with pulmonary contusion secondary to motor vehicular trauma were evaluated retrospectively to determine length of hospitalization, oxygen supplementation, and associated injuries. Therapeutic interventions, including the dose of intravenous fluid administration, the use of antibiotics, and the use of glucocorticoids were recorded. Initial thoracicradiographs were reviewed, and pulmonary contusion was graded as mild, moderate or severe. Pulmonary contusion severity was compared to use of supplemental oxygen, oxygen administration time, hospitalization time, and the presence or absence of fractures. The length of hospital stay and the survival rate was calculated.
The mean respiratory rate at admission was 55 ± 22 breaths per minute. Concurrent thoracicinjuries were common, and included pneumothorax and pleural effusion. Fifty-two percent ofdogs received oxygen supplementation for a median of 35 hours. The median hospitalization time was 48 hours. Forty (28%) dogs were treated with antibiotics for a minimum of 5 days, and forty- five (31%) were administered glucocorticoids. Two (1%) dogs developed pulmonary infection. Dogs with more severe thoracic radiographic changes on presentation were more likely to receiveoxygen, received oxygen for longer periods of time, and had a longer hospitalization time. Eighty-two percent of dogs survived to hospital discharge.     

Effect of short-term feed restriction and calorie source on hormonal and metabolic responses in geldings receiving a small meal

The metabolic effects of short-term feed restriction and dietary calorie source were studied in horses receiving high-roughage or high-concentrate diets. Four Thoroughbred geldings were assigned to four treatment groups in a 4 x 4 Latin square experiment. The four treatments were 1) a nutritionally adequate high-roughage ration (70% roughage, 30% concentrate; AHR), 2) a nutritionally adequate high-concentrate ration (40% roughage, 60% concentrate; AHC), 3) 70% of the intake of the AHR diet (RHR), and 4) 70% of the intake of the AHC diet (RHC). Diets AHR and AHC were designed to meet the caloric need of horses undergoing moderately intense work. Blood samples were taken on the first 7 d of each period for analysis of serum T4 and T3 concentrations. On d 9 of each feeding period, each horse was fed 1.0 kg of oats as the morning meal. Jugular blood was sampled before and immediately after, as well as at 30 min after, completion of the meal and subsequently every hour for 7 h. Daily serum T4 and T3 concentrations were not affected by day, feeding level, or diet composition. Meal feeding produced an increase (P < 0.01) in T4 and T3 concentrations when horses were adapted to the AHR and AHC diets but not the RHR or RHC diets. Thyroxine concentrations were lowest (P < 0.05) when horses were adapted to the AHC diet. Glucose (P < 0.05), insulin (P < 0.01), and NEFA (P < 0.01) concentrations were higher in response to the meal when horses received RHR than for the other diets. These results indicate that nutrient restriction alters responses to meal feeding in horses and that this response may also be affected by the dietary roughage:concentrate ratio.     

A cross-sectional survey on wounds in horses in New Zealand

AIM: To determine the frequency and type of skin wounds encountered by New Zealand veterinarians in their equine patients, the duration and estimated costs of treatment as well as the expected outcomes for these wounds.

METHODS: An online survey was sent to all veterinarians registered with the New Zealand Equine Veterinary Association. The survey comprised questions on the location and experience of respondents, the number of wound-related cases in relation to the total equine caseload, the type and anatomical location of wounds treated, the frequency, duration and costs of treatments, the outcome of wound treatment and an estimate of the most common causes of death or euthanasia in their equine patients.

RESULTS: The survey response rate was 110/262 (41.9%). The median number of equine cases seen by respondents was 20 (interquartile range (IQR) 6–60) per month; of these, five (IQR 2–10) were wound related. Wounds ranked third after lameness and respiratory disease for the relative frequency with which respondents encountered them. Of 102 respondents 59 (58%) reported that their clients frequently treated wounds incurred by their horse without consulting a veterinarian. Wounds on the distal limb, whether involving only the skin or also deeper structures, were reported by 86/101 (85%) respondents as the most frequently encountered. Wounds in this location also incurred the longest treatment period and were the most prone to develop complications. Finally, wounds ranked second, after colic, as the most common cause of death/euthanasia in the veterinary respondents’ equine patients.

CONCLUSIONS: The data obtained via the survey indicate that skin wounds, particularly on the distal limb, are a common occurrence in horses in New Zealand and, when they involve structures underlying the skin, are costly and time-consuming to manage and may lead to decreased performance, retirement or euthanasia. Consequently, we recommend that more effort be devoted to the education of equine veterinarians and owners, and that appropriate research funds be allocated to help improve patient outcomes.