Women with primary mitral insufficiency have a smaller regurgitant volume at the same regurgitant fraction than men. We hypothesized that normalizing regurgitant volume with left ventricular end-diastolic volume or allometric scaling would eliminate the difference in regurgitant volume between women and men. The study cohort consisted of 101 patients with mitral valve prolapse undergoing cardiac MRI.
View Article and Find Full Text PDFGuidelines suggest using a regurgitant fraction of 50% and regurgitant volume of 60 ml for determination of severe mitral insufficiency. Recent MRI data has suggested that a regurgitant fraction of 40% defines severe primary mitral insufficiency. We sought to determine whether there were gender differences in primary mitral regurgitant volumes for regurgitant fractions of 40% and 50%.
View Article and Find Full Text PDFBackground: Many mammalian species have experienced range contractions. Following a reduction in distribution that has resulted in apparently small and disjunct populations, the Humboldt marten () was recently designated as federally Threatened and state Endangered. This subspecies of Pacific marten occurring in coastal Oregon and northern California, also known as coastal martens, appear unlike martens that occur in snow-associated regions in that vegetation associations appear to differ widely between Humboldt marten populations.
View Article and Find Full Text PDFResearch hypotheses have been a cornerstone of science since before Galileo. Many have argued that hypotheses (1) encourage discovery of mechanisms, and (2) reduce bias-both features that should increase transferability and reproducibility. However, we are entering a new era of big data and highly predictive models where some argue the hypothesis is outmoded.
View Article and Find Full Text PDFBackground: Studies of animal movement using location data are often faced with two challenges. First, time series of animal locations are likely to arise from multiple behavioral states (e.g.
View Article and Find Full Text PDFThe complex topography, climate, and geological history of Western North America have shaped contemporary patterns of biodiversity and species distributions in the region. Pacific martens (Martes caurina) are distributed along the northern Pacific Coast of North America with disjunct populations found throughout the Northwestern Forested Mountains and Marine West Coast Forest ecoregions of the West Coast. Martes in this region have been classified into subspecies; however, the subspecific designation has been extensively debated.
View Article and Find Full Text PDFPacific martens (Martes caurina) are often associated with mature forests with complex structure for denning, resting, and efficient hunting. Nonetheless, a small isolated population of the Humboldt subspecies of Pacific martens (Martes caurina humboldtensis) occupies a narrow strip of young, coastal forest (< 70 years old) but not inland mature forest in the central Oregon Coast Range. We examined factors contributing to this unexpected distribution of martens by 1) analyzing marten diets using DNA metabarcoding to assess 90 scats, 2) using camera traps to assess differences in the relative abundances of prey, competitors, and predators across a coastal to inland gradient of vegetation types, and 3) quantifying differences in extent of fruit-producing shrubs and vegetation structure within vegetation types.
View Article and Find Full Text PDFForest management guidelines for rare or declining species in the Pacific Northwest, USA, include both late successional reserves and specific vegetation management criteria. However, whether current management practices for well-studied species such as northern spotted owls (Strix occidentallis caurina) can aid in conserving a lesser known subspecies-Humboldt martens (Martes caurina humboldtensis)-is unclear. To address the lack of information for martens in coastal Oregon, USA, we quantified vegetation characteristics at locations used by Humboldt martens and spotted owls in two regions (central and southern coast) and at two spatial scales (the site level summarizing extensive vegetation surveys and regionally using remotely sensed vegetation and estimated habitat models).
View Article and Find Full Text PDFBackground: The study aim was to determine the prevalence of normally functioning mitral prostheses with mean gradient ≥10 mmHg, and to identify the characteristics and echocardiographic variables that might be useful to distinguish normal function from dysfunction.
Methods: A total of 56 consecutive patients with a prosthetic mitral valve and mean gradient ≥10 mmHg was retrospectively identified. Nineteen patients without subsequent imaging confirming normal prosthesis function or dysfunction were excluded; hence, 37 patients were classified as obstruction, insufficiency, or normal prosthesis (high-gradient; NPHG).
Pacific martens () in coastal forests of Oregon and northern California in the United States are rare and geographically isolated, prompting a petition for listing under the Endangered Species Act. If listed, regulations have the potential to influence land-use decisions on public and private lands, but no estimates of population size, density, or viability of remnant marten populations are available for evaluating their conservation status. We used GPS and VHF telemetry and spatial mark-resight to estimate home ranges, density, and population size of Pacific martens in the Oregon Dunes National Recreation Area, central coast Oregon, USA.
View Article and Find Full Text PDFAbstract The use of midazolam as a tranquilizer for anesthesia in mustelids in conjunction with the cyclohexamine ketamine is not well documented. Because midazolam is fast acting, inexpensive, and quickly metabolized, it may serve as a good alternative to other more commonly used tranquilizers. We trapped and anesthetized 27 Pacific martens (Martes caurina) in Lassen National Forest (northern California, US) August 2010-April 2013.
View Article and Find Full Text PDFThe definition of estrogen's actions has expanded from transcriptional regulation to the rapid, membrane-initiated activation of numerous signal transduction cascades. Multiple biological effects of estrogen have been shown in numerous animals, cellular and molecular studies, which support the favorable effects of estrogen on vascular structure, function, and cell signaling. Work from several laboratories has shown that these effects are mediated by distinct forms of estrogen receptor (ER) alpha.
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