Pathology of inhalational anthrax infection in the african green monkey

There is a critical need for an alternative nonhuman primate model for inhalational anthrax infection because of the increasingly limited supply and cost of the current model. This report describes the pathology in 12 African green monkeys (AGMs) that succumbed to inhalational anthrax after exposure to a low dose (presented dose 200-2 x 10(4)colony-forming units [cfu]) or a high dose (presented dose 2 x 10(4)-1 x 10(7) cfu) of Bacillus anthracis (Ames strain) spores. Frequent gross lesions noted in the AGM were hemorrhage and edema in the lung, mediastinum, and mediastinal lymph nodes; pleural and pericardial effusions; meningitis; and gastrointestinal congestion and hemorrhage. Histopathologic findings included necrohemorrhagic lymphadenitis of mediastinal, axillary, inguinal, and mesenteric lymph nodes; mediastinal edema; necrotizing splenitis; meningitis; and congestion, hemorrhage, and edema of the lung, mesentery, mesenteric lymph nodes, gastrointestinal tract, and gonads. Pathologic changes in AGMs were remarkably similar to what has been reported in rhesus macaques and humans that succumbed to inhalational anthrax; thus, AGMs could serve as useful models for inhalation anthrax studies.     

Favism-inducing toxins in broad beans (Vicia faba): Estimation of the vicine contents of broad bean and other legume samples

A method for the estimation of vicine in leguminous seeds and related material has been developed. It involves the extraction and isolation of mixed pyrimidine bases, thin layer chromatography and spectrophotometry. Results obtained withVicia faba (broad bean) samples from various sources are recorded and reference made to data obtained from some other leguminous crops.     

Favism-inducing toxins in broad beans (Vicia faba) examination of bean extracts for pyrimidine glucosides

Methods for the isolation and identification of the pyrimidine glucoside, vicine, in extracts of broad beans, are described, By thin-layer chromatography, five fluorescing or fluorescencequenching components of the extracts are identifiable. One of them, which has been isolated from the mixture, is identified as vicine, 2:4-diamino-5:6-dihydroxypyrimidine-5-(-D-glucopyranoside).     

Chemical repellents appear non-useful for eliciting exit of brown tree snakes from cargo

The brown tree snake (Boiga irregularis) is invasive in Guam, has imposed ecological and economic problems there, and threatens to be dispersed via cargo and vehicles to other islands in the Pacific, where it could be expected to inflict similar damages. Prevention of inadvertent snake export currently relies on cargo inspection and suppression of snake populations around ports, which are expensive and incompletely reliable. Hence, there has long been interest in developing additional tools to preclude snakes leaving in cargo, and fumigation with essential oils has been suggested for this role. We tested gaseous or aerosol deliveries of several essential oils and three other candidate irritants. We found none to work reliably in repelling snakes, and we discuss several limitations that make development of an effective fumigation tool from these chemicals improbable. Additional effort to develop an operational tool using essential oils would likely be misdirected, and effective fumigation methods for invasive snakes should be sought elsewhere.     

Effect of soil moisture and bovine urine on microbial stress

While many studies have examined the cycling of urinary nutrients, few have focused on the effects ruminant urine might have on the soil microbial community. Urine application can cause microbial communities to become stressed, potentially changing community composition and microbial function with subsequent effects on nutrient dynamics. Identification of the factors that stress microbes may assist in explaining ruminant urine effects on nutrient cycling. In this laboratory study bovine urine, with either a high (15.0 g K⁺ l^?1) or low (10.4 g K⁺ l^?1) salt concentration, was added to repacked soil cores maintained at high or low soil moisture contents (70 or 35% water-filled pore space, respectively). Control cores did not receive urine. Microbial stress was measured using phospholipid fatty acid (PLFA) biomarker ratios. Urine addition increased stress as indicated by a decrease in the iso15:0/anteiso15:0 PLFA ratio from >1.35 to <0.95 in both wet and dry soils and by an increase in the 18:1ω9trans/18:1ω9cis PLFA ratio from 1.4 to 1.9 from day 8 onwards in wet soils. Higher stress was indicated by a lower Gram-positive/Gram-negative PLFA ratio in the urine treatments than in the control treatments on day 29 and this may have been a response to the reduction in substrate availability as the experiment progressed. The PLFA biomarkers showed that the salt treatments did not induce stress. Stress induced by urine addition and wet soil treatments was also indicated by principal component analyses and the metabolic quotient for CO₂, respectively. Thus microbial stress was induced by both urine addition and high soil moisture content, but not specifically by increasing the urinary salt concentration.     

Short-term consequences of spatial heterogeneity in soil nitrogen concentrations caused by urine patches of different sizes

The scale of spatial heterogeneity in soil nitrogen (N) concentrations varies considerably in grazed systems, because grazers vary in the volume of urine they excrete. This could affect how urine-N is processed, and subsequently how much N is lost from the system, as diffusion and plant effects on soil nutrient concentrations can be scale-dependent. Two field experiments were performed; one measured the impact of urine patch size (small, medium or large) on soil inorganic N pools and fluxes over time, and the other assessed whether urine patch size affected plant responses and system N retention even if the same total amount of urine was applied. Soil from inside small urine patches retained inorganic N for shorter amounts of time, resulting in lower plant biomass and N uptake than that inside larger patches. Although system nitrogen retention was not affected by patch size, it appeared that larger patches had a greater potential to lose N due to the longer period over which soil inorganic N concentrations remained high. This suggests that systems grazed by larger organisms are more prone to lose N through patch size effects than those grazed by smaller ones.     

Influence of woody and herbaceous competition on microclimate and growth of eastern white pine (Pinus strobus L.) seedlings planted in a central Ontario clearcut

The influence of woody and herbaceous plant competition, either alone or in combination, on microclimate and growth of planted eastern white pine (Pinus strobus L.) seedlings was examined over four consecutive growing seasons in a central Ontario clearcut. Treatments that manipulated the comparative abundance of these two plant functional groups significantly affected light availability, soil moisture, and air and soil temperature regimes. These microclimate alterations, coupled with the relative competitiveness of herbaceous and woody vegetation, corresponded to temporal changes in vegetation cover and dominance. The more rapid colonization and growth of the herbaceous plant community, dominated by bracken fern (Pteridium aquilinum) and ericaceous shrubs (Kalmia sp., Vaccinium sp.), resulted in this form of vegetation being a comparatively important early competitor for soil moisture. As the woody plant community, dominated by naturally regenerated trembling aspen (Populus tremuloides Michx.), grew in height and leaf area, it became a comparatively strong competitor for both light and soil moisture. For all vegetation treatments combined, white pine seedling growth responses were strongly correlated with total cover of competing vegetation and its relative influence on above- and belowground microclimatic variables. Higher total cover of competing vegetation was generally associated with lower light and soil moisture availability and cooler soil temperatures. Multiple regression analyses indicated that pine seedling relative height growth increased with soil moisture content and growing season soil heat sum, while seedling relative diameter and relative volume growth increased with light availability.     

Influence of woody and herbaceous vegetation control on leaf gas exchange,water status,and nutrient relations of eastern white pine (Pinus strobus L.) seedlings planted in a central Ontario clearcut

The influence of herbaceous and woody vegetation control, either singly or in combination, on leaf gas exchange, water status, and nutrient relations of planted eastern white pine (Pinus strobus L.) seedlings was examined in a central Ontario clearcut over four consecutive growing seasons (GSs). Net carbon assimilation (A_n), leaf conductance to water vapour (G_wv), water use efficiency (WUE), and midday leaf water potential (ψ_m) were measured periodically during the second to fourth GSs of vegetation control treatments, while leaf nutrient relations were examined in GS five. Leaf A_n and G_wv were reduced (p ≤ 0.05) in the presence of herbaceous vegetation in GS two, by both herbaceous and woody vegetation in GS three, and only by woody vegetation (largely trembling aspen (Populus tremuloides Michx.)) in GS four. Leaf WUE was increased (p ≤ 0.05) in all three GSs in which herbaceous vegetation control was applied and where woody vegetation provided partial shading of planted white pine. Leaf water status was comparatively less responsive to vegetation control treatments, but leaf ψ_m was increased (p ≤ 0.05) in the presence of woody vegetation in GSs two and four, likely due to shading and reduced atmospheric evaporative demand of the white pine seedling environment. Within a given GS, the effects of vegetation control on A_n, G_wv, and ψ_m were strongly linked to treatment-induced changes in total vegetative cover, and light and soil moisture availability. Seedling height, diameter, and volume growth rates were positively correlated with A_n and WUE in GSs two and three, but less so in GS four. Vector analysis suggested that herbaceous competition induced foliar N, P, and K deficiencies in five-year-old white pine seedlings while competition from aspen resulted in foliar Ca deficiency.     

A review of the use of a controlled-release formulation of ivermectin in the treatment and prophylaxis of Psoroptes ovis infestations in sheep.

The options for the treatment and control of sheep scab (psoroptic mange) have been increased in recent years through the introduction of the endectocides ivermectin, doramectin and moxidectin. Whilst therapeutic efficacy is good, the current injectable formulations offer limited protection against re-infestation with Psoroptes ovis. An intraruminal controlled-release formulation of ivermectin has been developed to provide therapeutic and prophylactic activity against a range of sensitive endo- and ecto-parasites of sheep for 100 days after administration. These ivermectin boluses are designed to release ivermectin at 20-40 microg/kg/day over 100 days and were developed for use in sheep of 20-90 kg bodyweight. Several controlled therapeutic and prophylactic trials against sheep scab have been conducted under a variety of protocols with such boluses in Europe and South America. The results of these studies indicate that the bolus provides 100% therapeutic efficacy against established P. ovis infestations and equivalent prophylactic efficacy against challenge infestations administered during the active life of the bolus.