257 research outputs found
社団法人神緑会事業報告1
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.
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
Renormalized Quantum Yang-Mills Fields in Curved Spacetime
We present a proof that quantum Yang-Mills theory can be consistently defined
as a renormalized, perturbative quantum field theory on an arbitrary globally
hyperbolic curved, Lorentzian spacetime. To this end, we construct the
non-commutative algebra of observables, in the sense of formal power series, as
well as a space of corresponding quantum states. The algebra contains all gauge
invariant, renormalized, interacting quantum field operators (polynomials in
the field strength and its derivatives), and all their relations such as
commutation relations or operator product expansion. It can be viewed as a
deformation quantization of the Poisson algebra of classical Yang-Mills theory
equipped with the Peierls bracket. The algebra is constructed as the cohomology
of an auxiliary algebra describing a gauge fixed theory with ghosts and
anti-fields. A key technical difficulty is to establish a suitable hierarchy of
Ward identities at the renormalized level that ensure conservation of the
interacting BRST-current, and that the interacting BRST-charge is nilpotent.
The algebra of physical interacting field observables is obtained as the
cohomology of this charge. As a consequence of our constructions, we can prove
that the operator product expansion closes on the space of gauge invariant
operators. Similarly, the renormalization group flow is proved not to leave the
space of gauge invariant operators.Comment: Latex 144pp, no figures, review style presentation; v2: equations
corrected, details in proof of Ward-identity added, discussion of state
space, refs. added; v3: typos corrected, details added in renormalization
section, one subsection removed; v4 BRST-invariant state, typos corrected,
background field discussion clarified, hyperref feature adde
Resolving the ancestry of Austronesian-speaking populations
There are two very different interpretations of the prehistory of Island Southeast Asia (ISEA), with genetic evidence invoked in support of both. The “out-of-Taiwan” model proposes a major Late Holocene expansion of Neolithic Austronesian speakers from Taiwan. An alternative, proposing that Late Glacial/postglacial sea-level rises triggered largely autochthonous dispersals, accounts for some otherwise enigmatic genetic patterns, but fails to explain the Austronesian language dispersal. Combining mitochondrial DNA (mtDNA), Y-chromosome and genome-wide data, we performed the most comprehensive analysis of the region to date, obtaining highly consistent results across all three systems and allowing us to reconcile the models. We infer a primarily common ancestry for Taiwan/ISEA populations established before the Neolithic, but also detected clear signals of two minor Late Holocene migrations, probably representing Neolithic input from both Mainland Southeast Asia and South China, via Taiwan. This latter may therefore have mediated the Austronesian language dispersal, implying small-scale migration and language shift rather than large-scale expansion
High familial burden of cancer correlates with improved outcome from immunotherapy in patients with NSCLC independent of somatic DNA damage response gene status
Family history of cancer (FHC) is a hallmark of cancer risk and an independent predictor of outcome, albeit with uncertain biologic foundations. We previously showed that FHC-high patients experienced prolonged overall (OS) and progression-free survival (PFS) following PD-1/PD-L1 checkpoint inhibitors. To validate our findings in patients with NSCLC, we evaluated two multicenter cohorts of patients with metastatic NSCLC receiving either first-line pembrolizumab or chemotherapy. From each cohort, 607 patients were randomly case–control matched accounting for FHC, age, performance status, and disease burden. Compared to FHC-low/negative, FHC-high patients experienced longer OS (HR 0.67 [95% CI 0.46–0.95], p = 0.0281), PFS (HR 0.65 [95% CI 0.48–0.89]; p = 0.0074) and higher disease control rates (DCR, 86.4% vs 67.5%, p = 0.0096), within the pembrolizumab cohort. No significant associations were found between FHC and OS/PFS/DCR within the chemotherapy cohort. We explored the association between FHC and somatic DNA damage response (DDR) gene alterations as underlying mechanism to our findings in a parallel cohort of 118 NSCLC, 16.9% of whom were FHC-high. The prevalence of ≥ 1 somatic DDR gene mutation was 20% and 24.5% (p = 0.6684) in FHC-high vs. FHC-low/negative, with no differences in tumor mutational burden (6.0 vs. 7.6 Mut/Mb, p = 0.6018) and tumor cell PD-L1 expression. FHC-high status identifies NSCLC patients with improved outcomes from pembrolizumab but not chemotherapy, independent of somatic DDR gene status. Prospective studies evaluating FHC alongside germline genetic testing are warranted
Aboriginal Australian mitochondrial genome variation - An increased understanding of population antiquity and diversity
Aboriginal Australians represent one of the oldest continuous cultures outside Africa, with evidence indicating that their ancestors arrived in the ancient landmass of Sahul (present-day New Guinea and Australia) ∼55 thousand years ago. Genetic studies, though limited, have demonstrated both the uniqueness and antiquity of Aboriginal Australian genomes. We have further resolved known Aboriginal Australian mitochondrial haplogroups and discovered novel indigenous lineages by sequencing the mitogenomes of 127 contemporary Aboriginal Australians. In particular, the more common haplogroups observed in our dataset included M42a, M42c, S, P5 and P12, followed by rarer haplogroups M15, M16, N13, O, P3, P6 and P8. We propose some major phylogenetic rearrangements, such as in haplogroup P where we delinked P4a and P4b and redefined them as P4 (New Guinean) and P11 (Australian), respectively. Haplogroup P2b was identified as a novel clade potentially restricted to Torres Strait Islanders. Nearly all Aboriginal Australian mitochondrial haplogroups detected appear to be ancient, with no evidence of later introgression during the Holocene. Our findings greatly increase knowledge about the geographic distribution and phylogenetic structure of mitochondrial lineages that have survived in contemporary descendants of Australia's first settlers. © The Author(s) 2017
Baseline BMI and BMI variation during first line pembrolizumab in NSCLC patients with a PD-L1 expression >= 50%: a multicenter study with external validation
Background The association between obesity and
outcomes in patients receiving programmed death-1/
programmed death ligand-1 (PD-L1) checkpoint inhibitors
has already been confirmed in pre-treated non-small cell
lung cancer (NSCLC) patients, regardless of PD-L1 tumor
expression.
Methods We present the outcomes analysis according
to baseline body mass index (BMI) and BMI variation in a
large cohort of metastatic NSCLC patients with a PD-L1
expression ≥50%, receiving first line pembrolizumab.
We also evaluated a control cohort of metastatic
NSCLC patients treated with first line platinum-based
chemotherapy. Normal weight was set as control group.
Results 962 patients and 426 patients were included
in the pembrolizumab and chemotherapy cohorts,
respectively. Obese patients had a significantly higher
objective response rate (ORR) (OR=1.61 (95% CI: 1.04–
2.50)) in the pembrolizumab cohort, while overweight
patients had a significantly lower ORR (OR=0.59 (95%
CI: 0.37–0.92)) within the chemotherapy cohort. Obese
patients had a significantly longer progression-free
survival (PFS) (HR=0.61 (95% CI: 0.45–0.82)) in the
pembrolizumab cohort. Conversely, they had a significantly
shorter PFS in the chemotherapy cohort (HR=1.27 (95%
CI: 1.01–1.60)). Obese patients had a significantly longer
overall survival (OS) within the pembrolizumab cohort
(HR=0.70 (95% CI: 0.49–0.99)), while no significant
differences according to baseline BMI were found in the
chemotherapy cohort. BMI variation significantly affected
ORR, PFS and OS in both the pembrolizumab and the
chemotherapy cohorts.
Conclusions Baseline obesity is associated to
significantly improved ORR, PFS and OS in metastatic
NSCLC patients with a PD-L1 expression of ≥50%,
receiving first line pembrolizumab, but not among
patients treated with chemotherapy. BMI variation is also
significantly related to clinical outcomes
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