What about upwind buffer zones for aerial applications?

Buffer zones are areas set adjacent to areas sprayed with pesticides in which spray drift can deposit without consequence. It has been suggested that buffer zones should totally surround areas to be sprayed. We reviewed the scientific literature and employed a recently developed mechanistic model of spray drift to assess the magnitude of upwind spray drift and the consequent need for upwind buffer zones. Neither the scientific literature nor the AgDRIFT model support the need for upwind buffer zones for typical aerial spray applications.     

White-tailed deer activity reconstructed from tree-rings in eastern boreal Canada

We evaluated the potential of tree-ring techniques for the reconstruction of recent and past seasonal activity of introduced white-tailed deer in a boreal environment of eastern Canada. Hoof scrape scars on balsam fir stems and trampling scars on roots were used to reconstruct deer activity during the winter and snow-free seasons, respectively. Tree damage showed that there was continuous deer activity in the north-central part of Anticosti Island since the mid-1960s. High scrape scars along tree stems (3–3.5 m from the ground) indicate that 1975, 1976, 1981, 1983 and 1985 were years of intensive food search by deer on high balsam fir foliage. The annual number of hoof scrape scars was low between 1982 and 1985, when severe defoliation by the spruce budworm, combined with deer browsing, led to high fir sapling mortality, food depletion, degradation of the winter shelter forests and a decrease in deer activity. The lowest scrape scars 50 cm above ground correspond to the mean height of the residual snowpack in the shelter forest at springtime, when deer start searching for food in nearby open sites and use logging roads, where dead and bonsai-like fir predominate due to overbrowsing. The trampling scar age frequency distribution from two sites indicated that deer activity during the snow-free season started synchronously in the late 1960s. In response to degradation of winter shelter forests, deer may have moved from the southern part to the north-central part of the island and other sectors to survive. Deer-induced tree damage and tree-ring techniques can thus be used to reconstruct past seasonal activity of white-tailed deer.     

Productivity is a poor predictor of plant species richness

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters(-2)) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.     

Ehrlichia and Babesia infections in dogs in The Netherlands

A retrospective study was performed at the Department of Clinical Sciences of Companion Animals at Utrecht University amongst 75 dogs diagnosed with a Babesia canis and/or an Ehrlichia canis infection. The majority of the dogs had visited an endemic area (most often the Mediterranean area or the Dutch Antilles), but two dogs became infected with Babesia in the Netherlands. Babesia infections were associated with a stay in an endemic area and an incubation period that are both significantly shorter (less than 3 months) than those for Ehrlichia and co-infections (more than 3 months). Reasons for the owner to seek veterinary attention (lethargy, anorexia, fever), findings from the physical examination (pale mucous membranes, hepato-/splenomegaly) and laboratory results (anemia, thrombocytopenia, hypo-albuminemia) were highly aspecific, making serology or PCR mandatory for diagnosing infections. Antigenic stimulation by the parasite sometimes resulted in immune-mediated diseases such as immune-mediated hemolytic anemia, thrombocytopenia, glomerulonefritis, and polyarthritis and in the case of ehrlichiosis in hypergammaglobulinemia. Specific therapy (imidocarb-diproprionate and/or doxycycline) was necessary, and because combined infections were common, it was considered appropriate to administer both drugs while the definitive diagnosis was being established. The prognosis was reasonably good, with almost half of all patients showing no clinical signs after treatment, although Babesia and co-infections were associated with a significantly longer survival sometimes resulted than Ehrlichia infections.     

Effects of enteral and intravenous fluid therapy, magnesium sulfate, and sodium sulfate on colonic contents and feces in horses

OBJECTIVE: To assess changes in systemic hydration, concentrations of electrolytes in plasma, hydration of colonic contents and feces, and gastrointestinal transit in horses treated with IV fluid therapy or enteral administration of magnesium sulfate (MgSO4), sodium sulfate (NaSO4), water, or a balanced electrolyte solution. ANIMALS: 7 horses with fistulas in the right dorsal colon (RDC). PROCEDURE: In a crossover design, horses alternately received 1 of 6 treatments: no treatment (control); IV fluid therapy with lactated Ringer's solution; or enteral administration of MgSO4, Na2SO4, water, or a balanced electrolyte solution via nasogastric intubation. Physical examinations were performed and samples of blood, RDC contents, and feces were collected every 6 hours during the 48 hour-observation period. Horses were muzzled for the initial 24 hours but had access to water ad libitum. Horses had access to hay, salt, and water ad libitum for the last 24 hours. RESULTS: Enteral administration of a balanced electrolyte solution and Na2SO4 were the best treatments for promoting hydration of RDC contents, followed by water. Sodium sulfate was the best treatment for promoting fecal hydration, followed by MgSO4 and the balanced electrolyte solution. Sodium sulfate caused hypocalcemia and hypernatremia, and water caused hyponatremia. CONCLUSIONS AND CLINICAL RELEVANCE: Enteral administration of a balanced electrolyte solution promoted hydration of RDC contents and may be useful in horses with large colon impactions. Enteral administration of either Na2SO4 or water may promote hydration of RDC contents but can cause severe electrolyte imbalances.     

A retrospective multi‐center study of treatment,outcome, and prognostic factors in 34 dogs with disseminated aspergillosis in Australia

BackgroundDisseminated aspergillosis (DA) in dogs has a guarded prognosis and there is a lack of a gold standard treatment protocol.ObjectiveTo retrospectively assess survival times and factors influencing survival times.AnimalsDogs diagnosed with DA from January 2007 to June 2017.MethodsDisseminated aspergillosis case data were retrieved from 13 Australian veterinary referral centers, with a diagnosis confirmed with culture or PCR. Factors influencing survival time after diagnosis were quantified using a Cox proportional hazards regression model.ResultsThirty‐four dogs met the study inclusion criteria. Twenty‐two dogs were treated with antifungal treatment and 12 dogs received no antifungal treatment. Accounting for censoring of dogs that were either still alive on the date of data collection or were loss to follow‐up, dogs treated with itraconazole alone (n = 8) had a median survival time (MST) of 63 (95% CI: 20−272) days compared to 830 (95% CI: 267‐1259) days for the n = 14 dogs that received multimodal antifungal therapy (χ2 test statistic 8.6; df = 1; P < .01). The daily hazard of death (DHOD) for dogs with abnormally high serum creatinine concentration at the time of diagnosis was 7.4 (95% CI: 1.9‐29) times that of dogs with serum creatinine within the reference interval.Conclusion and Clinical ImportanceSerum creatinine concentration at the time of diagnosis is a useful prognostic indicator for survival after a diagnosis of DA. The MST for dogs treated with multimodal antifungal therapy is longer than itraconazole alone and warrant further investigation (P < .01).