Persistence of a Geographically-Stable Hybrid Zone in Puerto Rican Dwarf Geckos

Determining the mechanisms that create and maintain biodiversity is a central question in ecology and evolution. Speciation is the process that creates biodiversity. Speciation is mediated by incompatibilities that lead to reproductive isolation between divergent populations and these incompatibilities can be observed in hybrid zones. Gecko lizards are a speciose clade possessing an impressive diversity of behavioral and morphological traits. In geckos, however, our understanding of the speciation process is negligible. To address this gap, we used genetic sequence data (both mitochondrial and nuclear markers) to revisit a putative hybrid zone between Sphaerodactylus nicholsi and Sphaerodactylus townsendi in Puerto Rico, initially described in 1984. First, we addressed discrepancies in the literature on the validity of both species. Second, we sampled a 10-km-wide transect across the putative hybrid zone and tested explicit predictions about its dynamics using cline models. Third, we investigated potential causes for the hybrid zone using species distribution modeling and simulations; namely, whether unique climatic variables within the hybrid zone might elicit selection for intermediate phenotypes. We find strong support for the species-level status of each species and no evidence of movement, or unique climatic variables near the hybrid zone. We suggest that this narrow hybrid zone is geographically stable and is maintained by a combination of dispersal and selection. Thus, this work has identified an extant model system within geckos that that can be used for future investigations detailing genetic mechanisms of reproductive isolation in an understudied vertebrate group

Alcohol consumption and cardiovascular outcomes in patients with nonalcoholic fatty liver disease: A population-based cohort study

Low-level alcohol consumption is associated with reduced cardiovascular disease (CVD) in the general population. It is unclear whether this association is seen in patients with nonalcoholic fatty liver disease (NAFLD) who have an increased risk of CVD. We examined the association between alcohol consumption and CVD-related outcomes in subjects with NAFLD from a general population cohort. Subjects participating in the 1994-1995 Busselton Health survey underwent clinical and biochemical assessment. NAFLD was identified using the Fatty Liver Index of \u3e60, and alcohol consumption quantified using a validated questionnaire. CVD hospitalizations and death during the ensuing 20 years were ascertained using the Western Australian data linkage system. A total of 659 of 4,843 patients were diagnosed with NAFLD. The average standard drinks per week was 8.0 for men and 4.0 for women. Men consuming 8-21 drinks per week had a 38% (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.43-0.90) lower risk of CVD hospitalization as compared with men consuming 1-7 drinks per week. With both men and women combined, consumption of 8-21 drinks per week was associated with a 32% (HR 0.68, 95% CI 0.49-0.93) reduction in CVD hospitalization in minimally adjusted and 29% (HR 0.71, 95% CI 0.51-0.99) in fully adjusted models. No protective association was observed with binge drinking. There was no association between alcohol consumption and CVD death. Conclusion: Low to moderate alcohol consumption is associated with fewer CVD hospitalizations but not CVD death in subjects with NAFLD

Strategies to address the shortcomings of commonly used advanced chronic heart failure descriptors to improve recruitment in palliative care research: A parallel mixed-methods feasibility study

Background:Recruitment challenges contribute to the paucity of palliative care research with advanced chronic heart failure patients.Aim:To describe the challenges and outline strategies of recruiting advanced chronic heart failure patients.Design:A feasibility study using a pre–post uncontrolled design.Setting:Advanced chronic heart failure patients were recruited at two nurse-led chronic heart failure disease management clinics in IrelandResults:Of 372 patients screened, 81 were approached, 38 were recruited (46.9% conversion to consent) and 25 completed the intervention. To identify the desired population, a modified version of the European Society of Cardiology definition was used together with modified New York Heart Association inclusion criteria to address inter-study site New York Heart Association classification subjectivity. These modifications substantially increased median monthly numbers of eligible patients approached (from 8 to 20) and median monthly numbers recruited (from 4 to 9). Analysis using a mortality risk calculator demonstrated that recruited patients had a median 1-year mortality risk of 22.7 and confirmed that the modified eligibility criteria successfully identified the population of interest. A statistically significant difference in New York Heart Association classification was found in recruited patients between study sites, but no statistically significant difference was found in selected clinical parameters between these patients.Conclusion:Clinically relevant modifications to the European Society of Cardiology definition and strategies to address New York Heart Association subjectivity may help to improve advanced chronic heart failure patient recruitment in clinical settings, thereby helping to address the paucity of palliative care research this population

Carotid intima-medial thickness measured on multiple ultrasound frames: evaluation of a DICOM-based software system

United Kingdo

Lipoprotein(a) and apolipoprotein(a) isoform size: Associations with angiographic extent and severity of coronary artery disease, and carotid artery plaque

Background and aims: Lipoprotein(a) [Lp(a)] is an emerging genetic risk factor for cardiovascular disease (CVD). We examined whether plasma Lp(a) concentration and apolipoprotein(a) [apo(a)] isoform size are associated with extent and severity of coronary artery disease (CAD), and the presence of carotid artery plaque. Methods: We included in our study male participants (n = 263) from a cohort with angiographically defined premature CAD (Carotid Ultrasound in Patients with Ischemic Heart Disease). The angiographic extent and severity of CAD were determined by the modified Gensini and Coronary Artery Stenosis≥20% (CAGE) scores. Carotid artery plaque was assessed by bilateral carotid B-mode ultrasound. Apo(a) isoform size was determined by LPA Kringle IV-2 copy number (KIV-2 CN). Results: Lp(a) concentration, but not KIV-2 CN, was positively associated with the Gensini score. The association remained significant following adjustment for conventional CVD risk factors (all p Conclusions: Lp(a) concentration, but not apo(a) isoform size, is independently associated with angiographic extent and severity of CAD. Neither Lp(a) nor apo(a) isoform size is associated with carotid artery plaque