Many studies of human populations have used the male-specific region of the Y chromosome (MSY) as a marker, but MSY sequence variants have traditionally been subject to ascertainment bias. Also, dating of haplogroups has relied on Y-specific short tandem repeats (STRs), involving problems of mutation rate choice, and possible long-term mutation saturation. Next-generation sequencing can ascertain single nucleotide polymorphisms (SNPs) in an unbiased way, leading to phylogenies in which branch-lengths are proportional to time, and allowing the times-to-most-recent-common-ancestor (TMRCAs) of nodes to be estimated directly. Here we describe the sequencing of 3.7 Mb of MSY in each of 448 human males at a mean coverage of 51×, yielding 13,261 high-confidence SNPs, 65.9% of which are previously unreported. The resulting phylogeny covers the majority of the known clades, provides date estimates of nodes, and constitutes a robust evolutionary framework for analyzing the history of other classes of mutation. Different clades within the tree show subtle but significant differences in branch lengths to the root. We also apply a set of 23 Y-STRs to the same samples, allowing SNP- and STR-based diversity and TMRCA estimates to be systematically compared. Ongoing purifying selection is suggested by our analysis of the phylogenetic distribution of nonsynonymous variants in 15 MSY single-copy genes.
We compared the type 1 and I11 collagen amounts and cross-linked telopeptides at the rupture site and two other sites of the same tendon. Tendon saniples of ten individuals with total Achilles tendon rupture and six healthy cadavers were collected. The newly synthesized type I and 111 procollagens were assessed by extracting the soluble propeptides PINP, PICP and PIIINP. The insoluble matrix was solubilized by heat denaturation and trypsin digestion. Hydroxyproline, the cross-linked telopeptide structures of type I (ICTP and SP 4) and I11 collagens (IIINTP) and the degradation product of type I11 collagen (tryptic PIIINP) were measured from the digests.The type 111 collagen content was significantly increased at the rupture site when compared to control sites (5-and 12-fold increased) or cadavers (5-fold increased). No changes in the amounts of newly synthesized type I and I11 procollagens were observed. The ICTP content decreased and the SP 4/ICTP ratio increased along with ageing, suggesting a structural change in the type of cross-link in the carboxyterminal telopeptide of type I collagen.Type 111 collagen has accumulated at the rupture site probably due to microtrauinas and the subsequent healing process. The increased content of type I11 collagen can cause thinner collagen fibers, decrease the tensile strength and may finally result in total rupture of the tendon. The age-related change in the nature of the cross-link in the carboxyterminal telopeptide may contribute to this weakening.
The proportion of Europeans descending from Neolithic farmers ∼10 thousand years ago (KYA) or Palaeolithic hunter-gatherers has been much debated. The male-specific region of the Y chromosome (MSY) has been widely applied to this question, but unbiased estimates of diversity and time depth have been lacking. Here we show that European patrilineages underwent a recent continent-wide expansion. Resequencing of 3.7 Mb of MSY DNA in 334 males, comprising 17 European and Middle Eastern populations, defines a phylogeny containing 5,996 single-nucleotide polymorphisms. Dating indicates that three major lineages (I1, R1a and R1b), accounting for 64% of our sample, have very recent coalescent times, ranging between 3.5 and 7.3 KYA. A continuous swathe of 13/17 populations share similar histories featuring a demographic expansion starting ∼2.1–4.2 KYA. Our results are compatible with ancient MSY DNA data, and contrast with data on mitochondrial DNA, indicating a widespread male-specific phenomenon that focuses interest on the social structure of Bronze Age Europe.
BackgroundSuicide is a serious public health challenge in circumpolar regions, especially among Indigenous youth. Indigenous communities, government agencies and health care providers are making concerted efforts to reduce the burden of suicide and strengthen protective factors for individuals, families and communities. The persistence of suicide has made it clear that more needs to be done.ObjectiveOur aim was to undertake a scoping review of the peer-reviewed literature on suicide prevention and interventions in Indigenous communities across the circumpolar north. Our objective was to determine the extent and types of interventions that have been reported during past decade. We want to use this knowledge to support community initiative and inform intervention development and evaluation.DesignWe conducted a scoping review of online databases to identify studies published between 2004 and 2014. We included articles that described interventions in differentiated circumpolar Indigenous populations and provided evaluation data. We retained grey literature publications for comparative reference.ResultsOur search identified 95 articles that focused on suicide in distinct circumpolar Indigenous populations; 19 articles discussed specific suicide-related interventions and 7 of these described program evaluation methods and results in detail. The majority of publications on specific interventions were found in North American countries. The majority of prevention or intervention documentation was found in supporting grey literature sources.ConclusionDespite widespread concern about suicide in the circumpolar world and active community efforts to promote resilience and mental well-being, we found few recorded programs or initiatives documented in the peer-reviewed literature, and even fewer focusing specifically on youth intervention. The interventions described in the studies we found had diverse program designs and content, and used varied evaluation methods and outcomes. The studies we included consistently reported that it was important to use community-based and culturally guided interventions and evaluations. This article summarizes the current climate of Indigenous circumpolar suicide research in the context of intervention and highlights how intervention-based outcomes have largely remained outside of peer-reviewed sources in this region of the world.
Circumpolar regions, and the nations within which they reside, have recently gained international attention because of shared and pressing public policy issues such as climate change, resource development, endangered wildlife and sovereignty disputes. In a call for national and circumpolar action on shared areas of concern, the Arctic states health ministers recently met and signed a declaration that identified shared priorities for international cooperation. Among the areas for collaboration raised, the declaration highlighted the importance of enhancing intercultural understanding, promoting culturally appropriate health care delivery and strengthening circumpolar collaboration in culturally appropriate health care delivery. This paper responds to the opportunity for further study to fully understand indigenous values and contexts, and presents these as they may apply to a framework that will support international comparisons and systems improvements within circumpolar regions. We explored the value base of indigenous peoples and provide considerations on how these values might interface with national values, health systems values and value bases between indigenous nations particularly in the context of health system policy-making that is inevitably shared between indigenous communities and jurisdictional or federal governments. Through a mixed methods nominal consensus process, nine values were identified and described: humanity, cultural responsiveness, teaching, nourishment, community voice, kinship, respect, holism and empowerment.
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