Greater Sage-Grouse and Severe Winter Conditions: Identifying Habitat for Conservation

Developing sustainable rangeland management strategies requires solution-driven research that addresses ecological issues within the context of regionally important socioeconomic concerns. A key sustainability issue in many regions of the world is conserving habitat that buffers animal populations from climatic variability, including seasonal deviation from long-term precipitation or temperature averages, and that can establish an ecological bottleneck by which the landscape-level availability of critical resources becomes limited. We integrated methods to collect landscape-level animal occurrence data during severe winter conditions with estimation and validation of a resource selection function, with the larger goal of developing spatially explicit guidance for rangeland habitat conservation. The investigation involved greater sage-grouse (Centrocercus urophasianus) that occupy a landscape that is undergoing human modification for development of energy resources. We refined spatial predictions by exploring how reductions in the availability of sagebrush (as a consequence of increasing snow depth) may affect patterns of predicted occurrence. Occurrence of sage-grouse reflected landscape-level selection for big sagebrush, taller shrubs, and favorable thermal conditions and avoidance of bare ground and anthropogenic features. Refinement of spatial predictions showed that important severe winter habitat was distributed patchily and was constrained in spatial extent (7–18% of the landscape). The mapping tools we developed offer spatially explicit guidance for planning human activity in ways that are compatible with sustaining habitat that functions disproportionately in population persistence relative to its spatial extent or frequency of use. Increasingly, place-based, quantitative investigations that aim to develop solutions to landscape sustainability issues will be needed to keep pace with human-modification of rangeland and uncertainty associated with global climate change and its effects on animal populations.     

Ochetostoma Erythrogrammon (Leuckart & Rüppell 1828) (Echiurida) from Isipingo Beach,Natal, South Africa

The first record of O. erythrogrammon from Isipingo was found in a crevice at the high-water mark. The specimen has a mucilaginous cap covering the posterior end of the trunk. The anatomy shows that the intestinal siphon terminates posteriorly at the opening of the rectal diverticulum into the rectum. There is a pair of anal vesicles beset with numerous stalked ciliated funnels. Replacement setae are found associated with each of the two functional setae. Each nephridium is provided with a single outgrowth which divides into two coiled appendages. There are 12 muscle bundles of limited extent.     

Organisms associated with the sandy-beach bivalve Donax serra Röding,with a description of Cercaria serrae sp. nov. (Trematoda)

Examination of two collections of Donax serra from a South African west coast beach revealed the presence of Ciliophora, Trematoda, Nematoda and a parasitic pycnogonid. This is the first record of a pycnogonid from the genus Donax and the first published report of such a parasite from any southern African bivalve mollusc. One of the two trematode species found is described as new and its epidemiology is discussed briefly. No epibiota were found on the bivalve shell.     

How do hedgerows influence soil organic carbon stock in livestock‐grazed pasture?

Hedgerows have the potential to influence ecosystem function in livestock‐grazed pasture. Despite this, they are often ignored when quantifying farmland ecosystem service delivery. In this study, we assess the contribution of hedgerows to the ecosystem function of carbon (C) storage, with a particular emphasis on soil organic carbon (SOC). We measured SOC stock (kg C m^?2), on an equivalent soil mass basis, at 0–0.15 m depth in pasture adjacent to 38 hedgerows (biotic) and 16 stone walls or fences (abiotic controls) across ten farms in the county of Conwy, Wales, UK. Pasture SOC stock (~7 kg C m^?2) was similar adjacent to biotic and abiotic field boundaries, positively associated with soil moisture and negatively with soil bulk density (BD). For biotic boundaries, two further variables were significantly associated with SOC stock, distance from hedgerow (decrease in SOC stock) and slope orientation (upslope SOC stock greater than downslope). For pasture adjacent to hedgerows, a model combining the aforementioned variables (BD, soil moisture, distance from hedgerow, slope orientation) explained 78% of variation in SOC stock. This study demonstrates that whilst hedgerows do have subtle positive effects on SOC stock in adjacent pasture, SOC storage adjacent to field boundaries is influenced more by soil moisture content and BD than field boundary type.     

Review and analysis of the potential for glyphosate to interact with the estrogen,androgen and thyroid pathways

Glyphosate was recently evaluated for its potential to interact with the estrogen, androgen and thyroid (EAT) hormone pathways, including steroidogenesis, under the United States Environmental Protection Agency's (USEPA) Endocrine Disruptor Screening Program (EDSP), then by Germany, the rapporteur Member State who led the European Annex 1 renewal for glyphosate, and then by the European Food Protection Agency (EFSA) also as part of the Annex 1 renewal for glyphosate. Under the EDSP, 11 Tier 1 assays were run following the USEPA's validated 890‐series test guidelines and included five in vitro and six in vivo assays to evaluate the EAT pathways. Steroidogenesis was evaluated as part of the estrogen and androgen pathways. An up‐to‐date critical review has been conducted that considered results from the EDSP Tier 1 battery, guideline regulatory studies and an in‐depth analysis of the literature studies that informed an endocrine assessment. A strength of this evaluation was that it included data across multiple levels of biological organization, and mammalian and nonmammalian test systems. There was strong agreement across the in vitro and in vivo Tier 1 battery, guideline studies and relevant literature studies, demonstrating that glyphosate does not interact with EAT pathways including steroidogenesis. Based on an analysis of the comprehensive toxicology database for glyphosate and the literature, this review has concluded that glyphosate does not have endocrine‐disrupting properties through estrogen, androgen, thyroid and steroidogenic modes of action. © 2020 Society of Chemical Industry     

Oxidative stress and liver disease.

Pro-oxidants are numerous and varied. Antioxidants are equally varied in their mechanism of action, and oxidative stress is likely not a simple arithmetic summation of these two opposing forces. More likely, it is a complex set of interrelated formulas with large areas of overlap and small areas of unique effect. In this article, the language of oxidative stress is reviewed, the consequences of oxidative stress are presented, the pathophysiology of oxidative stress in the liver is briefly discussed, and various antioxidant treatment options most relevant to small animal patients with liver disease are reviewed.     

Radiotherapy isocenters verified by matching to bony landmarks of the canine and feline head differ when localized using volumetric versus planar imaging

The “gold standard” for verification of patient positioning before linear accelerator‐based stereotactic radiation therapy is kilovoltage cone‐beam computed tomography (kV‐CBCT), which is not uniformly available or utilized; planar imaging is sometimes used instead. The primary aim of this study was to determine if the position of the bony skull, when used as a surrogate for isocenter verification, is different when orthogonal megavoltage (MV) portal or kilovoltage (kV/kV) radiographs are used for image guidance, rather than kV‐CBCT. A secondary aim was to determine the influence of intra‐observer variability, body size and skull conformation on positioning, as determined using these three imaging modalities. Dogs and cats receiving radiotherapy of the head were recruited for this prospective analytical study. Planar (MV portal and kV/kV images) and volumetric (kV‐CBCT) images were acquired before treatment, and manually coregistered with reference images. Differences in skull position when matched based on MV portal, kV/kV images and kV‐CBCT were compared. A total of 65 subjects and 148 unique datasets were evaluated. The Wilcoxon rank‐sum test was used to evaluate effects of transitioning between imaging modalities. When comparing magnitude of shifts in MV to kV‐CBCT, MV to kV/kV and kV/kV to kV‐CBCT, there were statistically significant differences. Results were not measurably impacted by body size, skull conformation or interobserver differences. Based on shift magnitude and direction, an isotropic setup margin of at least 1 mm should be incorporated within the planning target volume when MV or kV planar imaging is used for position verification.