239 research outputs found

    Completed cohomology of Shimura curves and a p-adic Jacquet-Langlands correspondence

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    We study indefinite quaternion algebras over totally real fields F, and give an example of a cohomological construction of p-adic Jacquet-Langlands functoriality using completed cohomology. We also study the (tame) levels of p-adic automorphic forms on these quaternion algebras and give an analogue of Mazur's `level lowering' principle.Comment: Updated version. Contains some minor corrections compared to the published versio

    On a Conjecture of Rapoport and Zink

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    In their book Rapoport and Zink constructed rigid analytic period spaces FwaF^{wa} for Fontaine's filtered isocrystals, and period morphisms from PEL moduli spaces of pp-divisible groups to some of these period spaces. They conjectured the existence of an \'etale bijective morphism FaFwaF^a \to F^{wa} of rigid analytic spaces and of a universal local system of QpQ_p-vector spaces on FaF^a. For Hodge-Tate weights n1n-1 and nn we construct in this article an intrinsic Berkovich open subspace F0F^0 of FwaF^{wa} and the universal local system on F0F^0. We conjecture that the rigid-analytic space associated with F0F^0 is the maximal possible FaF^a, and that F0F^0 is connected. We give evidence for these conjectures and we show that for those period spaces possessing PEL period morphisms, F0F^0 equals the image of the period morphism. Then our local system is the rational Tate module of the universal pp-divisible group and enjoys additional functoriality properties. We show that only in exceptional cases F0F^0 equals all of FwaF^{wa} and when the Shimura group is GLnGL_n we determine all these cases.Comment: v2: 48 pages; many new results added, v3: final version that will appear in Inventiones Mathematica

    Genomic history of the Italian population recapitulates key evolutionary dynamics of both Continental and Southern Europeans

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    Background: The cline of human genetic diversity observable across Europe is recapitulated at a micro-geographic scale by variation within the Italian population. Besides resulting from extensive gene flow, this might be ascribable also to local adaptations to diverse ecological contexts evolved by people who anciently spread along the Italian Peninsula. Dissecting the evolutionary history of the ancestors of present-day Italians may thus improve the understanding of demographic and biological processes that contributed to shape the gene pool of European populations. However, previous SNP array-based studies failed to investigate the full spectrum of Italian variation, generally neglecting low-frequency genetic variants and examining a limited set of small effect size alleles, which may represent important determinants of population structure and complex adaptive traits. To overcome these issues, we analyzed 38 high-coverage whole-genome sequences representative of population clusters at the opposite ends of the cline of Italian variation, along with a large panel of modern and ancient Euro-Mediterranean genomes. Results: We provided evidence for the early divergence of Italian groups dating back to the Late Glacial and for Neolithic and distinct Bronze Age migrations having further differentiated their gene pools. We inferred adaptive evolution at insulin-related loci in people from Italian regions with a temperate climate, while possible adaptations to pathogens and ultraviolet radiation were observed in Mediterranean Italians. Some of these adaptive events may also have secondarily modulated population disease or longevity predisposition. Conclusions: We disentangled the contribution of multiple migratory and adaptive events in shaping the heterogeneous Italian genomic background, which exemplify population dynamics and gene-environment interactions that played significant roles also in the formation of the Continental and Southern European genomic landscapes

    Whole-genome sequencing analysis of semi-supercentenarians

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    Extreme longevity is the paradigm of healthy aging as individuals who reached the extreme decades of human life avoided or largely postponed all major age-related diseases. In this study, we sequenced at high coverage (90X) the whole genome of 81 semi-supercentenarians and supercentenarians [105+/110+] (mean age: 106.6 ± 1.6) and of 36 healthy unrelated geographically matched controls (mean age 68.0 ± 5.9) recruited in Italy. The results showed that 105+/110+ are characterized by a peculiar genetic background associated with efficient DNA repair mechanisms, as evidenced by both germline data (common and rare variants) and somatic mutations patterns (lower mutation load if compared to younger healthy controls). Results were replicated in a second independent cohort of 333 Italian centenarians and 358 geographically matched controls. The genetics of 105+/110+ identified DNA repair and clonal haematopoiesis as crucial players for healthy aging and for the protection from cardiovascular events

    Exacerbation of cigarette smoke-induced pulmonary inflammation by Staphylococcus aureus Enterotoxin B in mice

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    <p>Abstract</p> <p>Background</p> <p>Cigarette smoke (CS) is a major risk factor for the development of COPD. CS exposure is associated with an increased risk of bacterial colonization and respiratory tract infection, because of suppressed antibacterial activities of the immune system and delayed clearance of microbial agents from the lungs. Colonization with <it>Staphylococcus aureus </it>results in release of virulent enterotoxins, with superantigen activity which causes T cell activation.</p> <p>Objective</p> <p>To study the effect of <it>Staphylococcus aureus </it>enterotoxin B (SEB) on CS-induced inflammation, in a mouse model of COPD.</p> <p>Methods</p> <p>C57/Bl6 mice were exposed to CS or air for 4 weeks (5 cigarettes/exposure, 4x/day, 5 days/week). Endonasal SEB (10 μg/ml) or saline was concomitantly applied starting from week 3, on alternate days. 24 h after the last CS and SEB exposure, mice were sacrificed and bronchoalveolar lavage (BAL) fluid and lung tissue were collected.</p> <p>Results</p> <p>Combined exposure to CS and SEB resulted in a raised number of lymphocytes and neutrophils in BAL, as well as increased numbers of CD8<sup>+ </sup>T lymphocytes and granulocytes in lung tissue, compared to sole CS or SEB exposure. Moreover, concomitant CS/SEB exposure induced both IL-13 mRNA expression in lungs and goblet cell hyperplasia in the airway wall. In addition, combined CS/SEB exposure stimulated the formation of dense, organized aggregates of B- and T- lymphocytes in lungs, as well as significant higher CXCL-13 (protein, mRNA) and CCL19 (mRNA) levels in lungs.</p> <p>Conclusions</p> <p>Combined CS and SEB exposure aggravates CS-induced inflammation in mice, suggesting that <it>Staphylococcus aureus </it>could influence the pathogenesis of COPD.</p

    The dynamics of university units as a multi-level process. Credibility cycles and resource dependencies

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    This paper presents an analysis of resource acquisition and profile development of institutional units within universities. We conceptualize resource acquisition as a two level nested process, where units compete for external resources based on their credibility, but at the same time are granted faculty positions from the larger units (department) to which they belong. Our model implies that the growth of university units is constrained by the decisions of their parent department on the allocation of professorial positions, which represent the critical resource for most units’ activities. In our field of study this allocation is largely based on educational activities, and therefore, units with high scientific credibility are not necessarily able to grow, despite an increasing reliance on external funds. Our paper therefore sheds light on the implications that the dual funding system of European universities has for the development of units, while taking into account the interaction between institutional funding and third-party funding

    High Log-Scale Expansion of Functional Human Natural Killer Cells from Umbilical Cord Blood CD34-Positive Cells for Adoptive Cancer Immunotherapy

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    Immunotherapy based on natural killer (NK) cell infusions is a potential adjuvant treatment for many cancers. Such therapeutic application in humans requires large numbers of functional NK cells that have been selected and expanded using clinical grade protocols. We established an extremely efficient cytokine-based culture system for ex vivo expansion of NK cells from hematopoietic stem and progenitor cells from umbilical cord blood (UCB). Systematic refinement of this two-step system using a novel clinical grade medium resulted in a therapeutically applicable cell culture protocol. CD56+CD3− NK cell products could be routinely generated from freshly selected CD34+ UCB cells with a mean expansion of >15,000 fold and a nearly 100% purity. Moreover, our protocol has the capacity to produce more than 3-log NK cell expansion from frozen CD34+ UCB cells. These ex vivo-generated cell products contain NK cell subsets differentially expressing NKG2A and killer immunoglobulin-like receptors. Furthermore, UCB-derived CD56+ NK cells generated by our protocol uniformly express high levels of activating NKG2D and natural cytotoxicity receptors. Functional analysis showed that these ex vivo-generated NK cells efficiently target myeloid leukemia and melanoma tumor cell lines, and mediate cytolysis of primary leukemia cells at low NK-target ratios. Our culture system exemplifies a major breakthrough in producing pure NK cell products from limited numbers of CD34+ cells for cancer immunotherapy

    The elite brain drain

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    We collect data on the movement and productivity of elite scientists. Their mobility is remarkable: nearly half of the world’s most-cited physicists work outside their country of birth. We show they migrate systematically towards nations with large R&D spending. Our study cannot adjudicate on whether migration improves scientists’ productivity, but we find that movers and stayers have identical h-index citations scores. Immigrants in the UK and US now win Nobel Prizes proportionately less often than earlier. US residents’ h-indexes are relatively high. We describe a framework where a key role is played by low mobility costs in the modern world

    Fishing for complementarities : competitive research funding and research productivity

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    This paper empirically investigates complementarities between different sources of research funding with regard to academic publishing. We find for a sample of UK engineering academics that competitive funding is associated with an increase in ex-post publications but that industry funding decreases the marginal utility of public funding by lowering the publication and citation rate increases associated with public grants. However, when holding all other explanatory variables at their mean, the negative effect of the interaction does not translate into an effective decrease in publication and citation numbers. The paper also shows that the positive effect of public funding is driven by UK research council and charity grants and that EU funding has no significant effect on publication outcomes
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