123 research outputs found

    Contrasting effects of hemiparasites on ecosystem processes: can positive litter effects offset the negative effects of parasitism?

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    Hemiparasites are known to influence community structure and ecosystem functioning, but the underlying mechanisms are not well studied. Variation in the impacts of hemiparasites on diversity and production could be due to the difference in the relative strength of two interacting pathways: direct negative effects of parasitism and positive effects on N availability via litter. Strong effects of parasitism should result in substantial changes in diversity and declines in productivity. Conversely, strong litter effects should result in minor changes in diversity and increased productivity. We conducted field-based surveys to determine the association of Castillejaoccidentalis with diversity and productivity in the alpine tundra. To examine litter effects, we compared the decomposition of Castilleja litter with litter of four other abundant plant species, and examined the decomposition of those four species when mixed with Castilleja. Castilleja was associated with minor changes in diversity but almost a twofold increase in productivity and greater foliar N in co-occurring species. Our decomposition trials suggest litter effects are due to both the rapid N loss of Castilleja litter and the effects of mixing Castilleja litter with co-occurring species. Castilleja produces litter that accelerates decomposition in the alpine tundra, which could accelerate the slow N cycle and boost productivity. We speculate that these positive effects of litter outweigh the effects of parasitism in nutrient-poor systems with long-lived hemiparasites. Determining the relative importance of parasitism and litter effects of this functional group is crucial to understand the strong but variable roles hemiparasites play in affecting community structure and ecosystem processes

    Recent developments in genetics and medically assisted reproduction: from research to clinical applications

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    Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved

    Counteracting Age-related Loss of Skeletal Muscle Mass: a clinical and ethnological trial on the role of protein supplementation and training load (CALM Intervention Study): study protocol for a randomized controlled trial

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    Recent developments in genetics and medically assisted reproduction : from research to clinical applications

    Get PDF
    Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.Peer reviewe

    Assisted Reproductive Technologies in Europe. Usage and Regulation in the Context of Cross-Boarder Reproductive Care

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    This chapter reviews assisted reproductive technologies (ART) usage and policies across European countries, and scrutinizes emerging issues related to cross-border reproductive care (or “reproductive tourism”). Although Europe is currently the largest market for ART, the extent of usage varies widely across countries, largely because of differences in the laws, the affordability, the types of reimbursement, and the norms surrounding childbearing and conception. Since 2009, the regulation of ART has been expanding in Europe, and all countries now have some form of ART legislation. Countries where the treatments are completely covered by national health plans have the highest level of ART utilization. Being in a legal marriage or a stable union is often a prerequisite for access to ART. Currently, only half of European countries allow single women to use ART, and even fewer grant access to lesbian women. Surrogate motherhood is strictly prohibited in many countries in Europe, and where it is allowed, strong restrictions against commercial surrogacy are in place. While restrictive national legislation can be easily circumvented by crossing national boundaries for ART treatments, questions of equity of access have been raised, as not all prospective parents can afford to travel for treatment
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