13 research outputs found
(η6-Benzophenone)(η5-pentaÂmethylÂcycloÂpentaÂdienÂyl)ruthenium(II) tetraÂphenylÂborate
The structure of the title compound, [Ru(C10H15)(C13H10O)](C24H20B), consists of discrete [Cp*Ru(II)benzophenone] cations and tetraÂphenylÂborate anions (Cp* = pentaÂmethylÂcycloÂpentaÂdienÂyl). Tethering the Cp*Ru group to one aryl ring of benzophenone results in average values of 1.42 (1) and 1.38 (1) Å for the C—C bond lengths in the Ru-tethered and untethered phenyl rings, respectively. The dihedral angle between the benzene and phenyl rings of the benzophenone group is 50.5 (1)°
Male-Mediated Gene Flow in Patrilocal Primates
BACKGROUND: Many group-living species display strong sex biases in dispersal tendencies. However, gene flow mediated by apparently philopatric sex may still occur and potentially alters population structure. In our closest living evolutionary relatives, dispersal of adult males seems to be precluded by high levels of territoriality between males of different groups in chimpanzees, and has only been observed once in bonobos. Still, male-mediated gene flow might occur through rare events such as extra-group matings leading to extra-group paternity (EGP) and female secondary dispersal with offspring, but the extent of this gene flow has not yet been assessed. METHODOLOGY/PRINCIPAL FINDINGS: Using autosomal microsatellite genotyping of samples from multiple groups of wild western chimpanzees (Pan troglodytes verus) and bonobos (Pan paniscus), we found low genetic differentiation among groups for both males and females. Characterization of Y-chromosome microsatellites revealed levels of genetic differentiation between groups in bonobos almost as high as those reported previously in eastern chimpanzees, but lower levels of differentiation in western chimpanzees. By using simulations to evaluate the patterns of Y-chromosomal variation expected under realistic assumptions of group size, mutation rate and reproductive skew, we demonstrate that the observed presence of multiple and highly divergent Y-haplotypes within western chimpanzee and bonobo groups is best explained by successful male-mediated gene flow. CONCLUSIONS/SIGNIFICANCE: The similarity of inferred rates of male-mediated gene flow and published rates of EGP in western chimpanzees suggests this is the most likely mechanism of male-mediated gene flow in this subspecies. In bonobos more data are needed to refine the estimated rate of gene flow. Our findings suggest that dispersal patterns in these closely related species, and particularly for the chimpanzee subspecies, are more variable than previously appreciated. This is consistent with growing recognition of extensive behavioral variation in chimpanzees and bonobos
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One-Year Outcomes of Transcarotid Artery Revascularization Versus Transfemoral Carotid Artery Stenting in a Medicare Database
Developing palliative care programs in indigenous communities using participatory action research: A Canadian application of the public health approach to palliative care
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One-year Outcomes of Transcarotid Artery Revascularization vs Carotid Endarterectomy in Medicare Database
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Long-Term Outcomes of Carotid Endarterectomy vs. Transfemoral Carotid Stenting in a Medicare-Matched Database
ImportanceCarotid endarterectomy is associated with lower risk of perioperative stroke compared to transfemoral carotid artery stenting in the treatment of carotid artery stenosis. However, there is discrepancy in data regarding long-term outcomes. We aimed to compare long-term outcomes of carotid endarterectomy vs transfemoral carotid artery stenting using the Medicare-matched Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database.MethodsWe assessed patients undergoing first-time carotid endarterectomy or transfemoral carotid artery stenting in VQI-VISION from January 2003 to December 2018. Patients with prior history of carotid revascularization, non-transfemoral stenting, stenting performed without distal embolic protection, multiple or non-atherosclerotic lesions, or concomitant procedures were excluded. The primary outcome of interest was all-cause mortality, any stroke, and combined endpoint of death or stroke. We additionally performed propensity score matching and stratification based on symptomatic status.ResultsA total of 80,146 carotid revascularizations were performed of which 72,615 were carotid endarterectomy and 7,531 were transfemoral carotid artery stenting. CEA was associated with significantly lower risk of death (57.8% vs. 70.4%, aHR 0.46, 95%CI 0.41-0.52, p<0.001), stroke (21.3% vs. 26.6%, aHR 0.63, 95%CI 0.57-0.69, p<0.001) and combined endpoint of death and stroke (65.3% vs. 76.5%, HR 0.49, 95%CI:0.44-0.55, p<0.001) at 10 years. These findings were reflected in the propensity-matched cohort (combined endpoint: 34.6% vs. 46.8%, HR 0.53, 95%CI: 0.46-0.62) at 4 years as well as stratified analyses of combined endpoint by symptomatic status (asymptomatic: 63.2% vs. 74.9%, HR 0.49, 95%CI: 0.43-0.58, p<0.001; symptomatic 69.9% vs. 78.3%, HR 0.51, 95%CI: 0.45-0.59, p<0.001) at 10 years.ConclusionsIn this analysis of North American real-world data, CEA was associated with greater long-term survival and fewer strokes compared to TFCAS. These findings support the continued use of CEA as the first-line revascularization procedure
Substitutions in woolly mammoth hemoglobin confer biochemical properties adaptive for cold tolerance
We have genetically retrieved, resurrected and performed detailed structure-function analyses on authentic woolly mammoth hemoglobin to reveal for the first time both the evolutionary origins and the structural underpinnings of a key adaptive physiochemical trait in an extinct species. Hemoglobin binds and carries O2; however, its ability to offload O2 to respiring cells is hampered at low temperatures, as heme deoxygenation is inherently endothermic (that is, hemoglobin-O2 affinity increases as temperature decreases). We identify amino acid substitutions with large phenotypic effect on the chimeric b/d-globin subunit of mammoth hemoglobin that provide a unique solution to this problem and thereby minimize energetically costly heat loss. This biochemical specialization may have been involved in the exploitation of high-latitude environments by this African-derived elephantid lineage during the Pleistocene period. This powerful new approach to directly analyze the genetic and structural basis of physiological adaptations in an extinct species adds an important new dimension to the study of natural selection.Kevin L Campbell, Jason E E Roberts, Laura N Watson, Jörg Stetefeld, Angela M Sloan, Anthony V Signore, Jesse W Howatt, Jeremy R H Tame, Nadin Rohland, Tong-Jian Shen, Jeremy J Austin, Michael Hofreiter, Chien Ho, Roy E Weber & Alan Coope