Effects of bovine leukemia virus infection on milk neutrophil function and the milk lymphocyte profile

The effects of bovine leukemia virus (BLV) on the immune response have been extensively investigated; however, its effects on mammary gland immunity are only speculative. Although BLV has a tropism for B cells, it can affect both adaptive and innate immunities because these systems share many effector mechanisms. This scenario is the basis of this investigation of the effects of BLV on mammary gland immunity, which is largely dependent upon neutrophilic functions. Thus, the present study sought to examine neutrophilic functions and the lymphocyte profile in the milk of naturally BLV-infected cows. The viability of the milk neutrophils and the percentage of milk neutrophils that produced reactive oxygen species (ROS) or phagocytosed Staphylococcus aureus were similar between BLV-infected and BLV-uninfected dairy cows. Furthermore, the expression of CD62L and CD11b by the milk neutrophils and the percentage of milk neutrophils (CH138⁺ cells) that were obtained from the udder quarters of the BLV-infected cows were not altered. Conversely, the median fluorescence intensity (MFI) representing intracellular ROS production and the phagocytosis of S. aureus, the expression of CD44 by the milk neutrophils and the percentage of apoptotic B cells were lower in the milk cells from BLV-infected dairy cows, particularly those from animals with persistent lymphocytosis (PL). The lymphocyte subsets were not different among the groups, with the exception of the percentage of CD5⁻/CD11b⁻ B cells, which was higher in the milk cells from BLV-infected cows, particularly those with PL. Thus, the present study provides novel insight into the implications of BLV infection for mammary gland immunity.     

Scale-dependent seasonal habitat selection by jaguars (Panthera onca) and pumas (Puma concolor) in Panama

Landscape Ecology - Few habitat modeling studies consider multiple spatial or temporal scales; less identify the operative scale of an organism's response to predictor variables. Optimizing...     

Matrix dominance and landscape resistance affect genetic variability and differentiation of an Atlantic Forest pioneer tree

Landscape Ecology - Despite the importance of secondary forests for the maintenance of biodiversity, the impact of pioneer trees on habitat loss and fragmentation is poorly understood. We analyzed...     

Orchid bees respond to landscape composition differently depending on the multiscale approach

Landscape Ecology - Multiscale approaches are essential for understanding ecological processes and detecting the scale of effect. However, nested multiscale approaches retain the effect of the...     

Effects of rainfall,competition and grazing on flowering of Osteospermum sinuatum (Asteraceae) in arid Karoo rangeland

The shrub Osteospermum sinuatum, an important fodder plant in Karoo rangelands, flowered after heavy rain in autumn, winter and spring. The number of flowers produced per bush was positively conelated with basal stem diameter and rainfall in the 12 weeks before anthesis. Flowering increased when neighbouring plants of all species were removed. Grazing during flowering and seed set, by sheep stocked at recommended densities, reduced potential seed set by as much as 90%. Birds, hares and small antelope consumed 10–50% of the flowers. Size‐class distributions indicated that little recent recruitment had taken place on a ranch where palatable plants were scarce and where O. sinuatum flower production was severely depressed by grazing sheep.     

Comparison of water‐retention functions obtained from the extended evaporation method and the standard methods sand/kaolin boxes and pressure plate extractor

Knowledge of the soil hydraulic functions is required for various hydrological studies and for the simulation of water and solute fluxes in unsaturated soils. Sand/kaolin boxes are frequently used to determine these properties in the low‐tension range. For higher tensions the pressure plate extractor is mainly applied. The extended evaporation method allows a more efficient determination of the water‐retention curve in an adequate range. Besides this method enables to quantify simultaneously the unsaturated hydraulic‐conductivity function. The objective of this study was to compare the water‐retention curves obtained from the standard methods (STM) with those determined with the extended evaporation method (EEM). A set of 90 natural soil samples of different texture and origin was analyzed, and the agreement between the methods was statistically evaluated. The average water‐content deviation (AWCD) of all samples was 1.83 vol.%, and the root mean square error (RMSE) 2.08 vol.%. The deviation of soil water‐storage capacity in the pore‐size classes 0–6, 6–30, 30–500, 500–1500 kPa varied between minimum –0.17 and 0.25 vol.% and maximum –2.89 and 2.36 vol.%, and confirmed the good comparability among the adopted methods. Systematic deviations between the methods were not found.     

Nitrogen and Phosphorus Remediation by Three Floating Aquatic Macrophytes in Greenhouse-Based Laboratory-Scale Subsurface Constructed Wetlands

In the greenhouse and container nursery production industry there is potential for runoff of nitrogen (N) and phosphorus (P), which may contaminate surface and groundwater. Since the 1950s constructed wetlands (CWs), as a simple, low-technology method, have been shown to effectively treat agricultural, industrial, and municipal wastewater. We investigated the N and P attenuating potential of three floating hydrophytes planted in a laboratory-scale subsurface flow (SSF) CW system. Over an 8-week period plants were supplied with N and P (0.39 to 36.81 mg·L^?1 N and 0.07 to 6.77 mg·L^?1 P) that spanned the rates detected in nursery runoff between the discharge and inflow locations of a commercial nursery currently employing CWs. Whole plant dry weight was positively correlated with N and P supplied. Highest N recovery rates were exhibited by water hyacinth (Eichhornia crassipes [Mart.] Solms.) and water lettuce (Pistia stratiotes L.). P recovery rates were similar for water hyacinth, water lettuce, and dwarf redstemmed parrotfeather (Myriophyllum aquaticum [Vell.] Verdc.). These floating hydrophytes can be cultivated in a SSF CW to remediate runoff losses of N and P. The possibility exists for integrating them into a polycultural remediation system that includes emergent aquatic macrophytes for processing and polishing nursery/greenhouse wastewater.     

Effects of topical administration of an aldose reductase inhibitor on cataract formation in dogs fed a diet high in galactose

OBJECTIVE: To determine effects of a topical formulation of an aldose reductase inhibitor (ARI) on the development of sugar cataracts in dogs fed a diet high in galactose. Animals-Ten 6-month old Beagles. PROCEDURES: Dogs were fed a diet containing 30% galactose, and after 16 weeks, 6 dogs were treated topically with a proprietary ARI formulation and 4 dogs were treated with a placebo. Cataract formation was monitored by means of slit-lamp biomicroscopy and fundus photography. Dogs were euthanized after 10 weeks of treatment, and lenses were evaluated for degree of opacity, myo-inositol and galactitol concentrations, and concentration of the ARI. RESULTS: All dogs developed bilateral cortical opacities dense enough to result in a decrease in the tapetal reflex after being fed the galactose-containing diet for 16 weeks. Administration of the ARI arrested further development of cataract formation. In contrast, cataracts in the vehicle-treated dogs progressed over the 10-week period to the mature stage. Evaluation of the isolated lenses after 26 weeks of galactose feeding indicated that lenses from treated dogs were significantly less optically dense than lenses from control dogs. Lenticular myo-inositol concentration was significantly higher in the treated than in the control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that topical application of a proprietary ARI formulation may arrest or reverse the development of sugar cataracts in dogs fed a diet high in galactose. This suggests that this ARI formulation may be beneficial in maintaining or improving functional vision in diabetic dogs with early lens opacities.