The influence of matrix quality on species richness in remnant forest

Context

Habitat destruction is the leading threat to terrestrial biodiversity, isolating remnant habitat in a matrix of modified vegetation.

Objectives

Our goal was to determine how species richness in several broad taxonomic groups from remnant forest was influenced by matrix quality, which we characterized by comparing plant biomass in forest and the surrounding matrix.

Methods

We coupled data on species-area relationships (SARs) in forest remnants from 45 previously published studies with an index of matrix quality calculated using new estimates of plant biomass derived from satellite imagery.

Results

The effect size of SARs was greatest in landscapes with low matrix quality and little forest cover. SARs were generally stronger for volant than for non-volant species. For the terrestrial taxa included in our analysis, matrix quality decreased as the proportion of water, ice, or urbanization in a landscape increased.

Conclusions

We clearly demonstrate that matrix quality plays a major role in determining patterns of species richness in remnant forest. A key implication of our work is that activities that increase matrix quality, such as active and passive habitat restoration, may be important conservation measure for maintaining and restoring biodiversity in modified landscapes.

     

High-pressure balloon valvuloplasty for severe pulmonary valve stenosis: a prospective observational pilot study in 25 dogs

Objectives

We aimed to evaluate safety and efficacy of high-pressure balloon valvuloplasty (HPBVP) for treatment of canine severe pulmonary valve stenosis (PS). A secondary aim was to provide pre-procedure predictors of success.

Effects of selenium source on measures of selenium status and immune function in horses

The effects of selenium (Se) supplementation and source on equine immune function have not been extensively studied. This study examined the effects of oral Se supplementation and Se source on aspects of innate and adaptive immunity in horses. Fifteen horses were assigned to 1 of 3 groups (5 horses/group): control, inorganic Se (sodium selenite), organic Se (Se yeast). Immune function tests performed included: lymphocyte proliferation in response to mitogen concanavalin A, neutrophil phagocytosis, antibody production after rabies vaccination, relative cytokine gene expression in stimulated lymphocytes [interferon gamma (IFNγ), interleukin (IL)-2, IL-5, IL-10, tumor necrosis factor alpha (TNFα)], and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Plasma, red blood cell Se, and blood glutathione peroxidase activity were measured. Plasma and red blood cell Se were highest in horses in the organic Se group, compared with that of inorganic Se or control groups. Organic Se supplementation increased the relative lymphocyte expression of IL-5, compared with inorganic Se or no Se. Selenium supplementation increased relative neutrophil expression of IL-1 and IL-8. Other measures of immune function were unaffected. Dietary Se content and source appear to influence immune function in horses, including alterations in lymphocyte expression of IL-5, and neutrophil expression of IL-1 and IL-8.     

Combination CCNU and vinblastine chemotherapy for canine mast cell tumours: 57 cases

The purpose of this study was to evaluate the efficacy and toxicity of a CCNU and vinblastine chemotherapy protocol for canine mast cell tumours. Fifty-seven tumours in 56 dogs were evaluated, 37 had macroscopic disease and 20 had microscopic disease. A 57% response rate was seen in dogs with macroscopic disease for a median duration of 52 weeks. Dogs with macroscopic disease had a median progression free survival time (PFST) of 30 weeks and a median overall survival time (OST) of 35 weeks. Dogs with microscopic disease had a median PFST of 35 weeks and a median OST of 48 weeks. Toxicity was recorded in 54% of the dogs treated, with the majority of events being mild. This chemotherapy protocol appears to be well tolerated and should be considered for canine mast cell tumours.     

Preliminary investigation of the probiotic potential of Lactobacillus rhamnosus strain GG in horses: fecal recovery following oral administration and safety

This study was designed to evaluate whether Lactobacillus rhamnosus strain GG (LGG), an extensively studied probiotic organism in humans, can colonize the intestines of adult horses and foals. Lactobacillus rhamnosus strain GG was administered to adult horses at doses of 1 x 10(9) CFU/50kg bodyweight (BW)/day (group 1, 7 horses), 1 x 10(10) colony forming units/ 50kg BW/day (group 2, 7 horses) and 5 x 10(10) colony forming units/50kg BW/day (group 3, 7 horses) for 5 d. Foals received 2 x 10(10) colony forming units/50kg BW/day (group 1, 7 foals) or 1 x 10(11) colony forming units/50kg BW/day (group 2, 7 foals) for 5 d. Fecal levels of L. rhamnosus strain GG in adult horses were low and variable in the 2 lower dose groups. Even in the high dose group, colonization was relatively low. In contrast, more consistent intestinal colonization was present in foals, and colonization persisted for up to 9 d following cessation of administration. No adverse effects were observed in any animal. Clinical studies evaluating this probiotic are indicated in foals. The presence of this organism in the feces of adult horses may only represent passive movement through the intestinal tract, not actual colonization. Consistent intestinal colonization in adults was only achieved with a prohibitively high dose.     

Pediatric emergencies.

The unique anatomic and physiologic characteristics of neonatal and pediatric patients make diagnosis, monitoring, and treatment a challenge.Adult parameters cannot be relied on in these patients, and an awareness of these unique characteristics is essential for any practitioner with a neonatal and pediatric patient base. In addition, many laboratory and pharmacologic data differ dramatically in neonates compared with adults of the same species.Familiarity with these variations is essential in the monitoring and treatment of the neonatal and pediatric illness, such as hypovolemia, shock, and sepsis.     

Segmental aplasia of the caudal vena cava in a dog

Ultrasonography, angiography, magnetic resonance imaging, and exploratory laparotomy of a 2-year-old wheaten terrier with lethargy, exercise intolerance, and ascites revealed segmental aplasia of the caudal vena cava with azygos continuation, complicated by thrombus formation. Surgeries were performed on the blind-ended vessel to remove thrombi, enhancing shunting of blood through the azygos vein.