686 research outputs found

    Embracing conservation success of recovering humpback whale populations: Evaluating the case for downlisting their conservation status in Australia

    Get PDF
    Optimism and hope in conservation biology are supported by examples of endangered species recovery, such as the population growth observed in humpback whales in several of the world's oceans. In Australia, monitoring data suggest rapid recovery for both east and west coast populations, which are now larger than 50% of their pre-whaling abundance. The measured growth rates exceed known species trends worldwide and have no indication of diminishing. Under Australian Commonwealth legislation and regulations, these populations should be considered for downlisting, as they are not eligible for listing as a threatened species against all statutory criteria. A change in conservation status will produce new challenges for the conservation and management of a recovered species, especially with the Australian economic landscape experiencing large-scale growth and development in recent years. More importantly, a recovered humpback whale population may bring a positive shift in the research goals and objectives throughout Australia by ensuring other endangered species an equal chance of recovery while delivering hope, optimism, and an opportunity to celebrate a conservation success

    Novel targets for immune-checkpoint inhibition in cancer.

    Get PDF
    Immune-checkpoint inhibitors have revolutionized cancer therapy, yet many patients either do not derive any benefit from treatment or develop a resistance to checkpoint inhibitors. Intrinsic resistance can result from neoantigen depletion, defective antigen presentation, PD-L1 downregulation, immune-checkpoint ligand upregulation, immunosuppression, and tumor cell phenotypic changes. On the other hand, extrinsic resistance involves acquired upregulation of inhibitory immune-checkpoints, leading to T-cell exhaustion. Current data suggest that PD-1, CTLA-4, and LAG-3 upregulation limits the efficacy of single-agent immune-checkpoint inhibitors. Ongoing clinical trials are investigating novel immune-checkpoint targets to avoid or overcome resistance. This review provides an in-depth analysis of the evolving landscape of potentially targetable immune-checkpoints in cancer. We highlight their biology, emphasizing the current understanding of resistance mechanisms and focusing on promising strategies that are under investigation. We also summarize current results and ongoing clinical trials in this crucial field that could once again revolutionize outcomes for cancer patients

    社団法人神緑会事業報告1

    Get PDF
    Archaeology, linguistics, and existing genetic studies indicate that Oceania was settled by two major waves of migration. The first migration took place approximately 40 thousand years ago and these migrants, Papuans, colonized much of Near Oceania. Approximately 3.5 thousand years ago, a second expansion of Austronesian-speakers arrived in Near Oceania and the descendants of these people spread to the far corners of the Pacific, colonizing Remote Oceania. To assess the female contribution of these two human expansions to modern populations and to investigate the potential impact of other migrations, we obtained 1,331 whole mitochondrial genome sequences from 34 populations spanning both Near and Remote Oceania. Our results quantify the magnitude of the Austronesian expansion and demonstrate the homogenizing effect of this expansion on almost all studied populations. With regards to Papuan influence, autochthonous haplogroups support the hypothesis of a long history in Near Oceania, with some lineages suggesting a time depth of 60 thousand years, and offer insight into historical interpopulation dynamics. Santa Cruz, a population located in Remote Oceania, is an anomaly with extreme frequencies of autochthonous haplogroups of Near Oceanian origin; simulations to investigate whether this might reflect a pre-Austronesian versus Austronesian settlement of the island failed to provide unequivocal support for either scenario

    The Genetic Structure and History of Africans and African Americans.

    Get PDF
    Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (approximately 71%), European (approximately 13%), and other African (approximately 8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies

    Mongolians in the Genetic Landscape of Central Asia: Exploring the Genetic Relations among Mongolians and Other World Populations

    Get PDF
    Genetic data on North Central Asian populations are underrepresented in the literature, especially autosomal markers. In the present study we use 812 single nucleotide polymorphisms that are distributed across all the human autosomes and that have been extensively studied at Yale to examine the affinities of two recently collected, samples of populations: rural and cosmopolitan Mongolians from Ulaanbaatar and nomadic, Turkic-speaking Tsaatan from Mongolia near the Siberian border. We compare these two populations to one another and to a global set of populations and discuss their relationships to New World populations. Specifically, we analyze data on 521 autosomal loci (single SNPs and multi-SNP haplotypes) studied on 57 populations representing all the major geographical regions of the world. We conclude that the North Central Asian populations we study are genetically distinct from all other populations in our study and may be close to the ancestral lineage leading to the New World populations
    corecore