72 research outputs found

    Composite Adenocarcinoma and Carcinoid Gastric Tumor in Chronic Atrophic Gastritis and Pernicious Anemia

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    A 42-year-old Hispanic female was referred for investigation of unexplained weight loss. Initial upper endoscopy showed atrophic gastritis. Repeat endoscopy one year later revealed the presence of mixed composite tumor consisting of gastric adenocarcinoma and carcinoid tumors. Treatment was accomplished by surgical excision. Such cases are extremely rare and few such reports are available in the literature. We discuss the pathologies and means by which these tumors are classified and treated

    Energy-overlap of the Dirac surface state with bulk bands in SnBi2Te4

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    Topological insulators in which the Fermi level is in the bulk gap and intersects only a topological surface state (the Dirac cone) are of special interest in the current research. In the last decades, a fine-tuning of the chemical composition of topological insulators has been carefully explored in order to control the Fermi level position with respect to the Dirac surface state. Taking the SnBi 2 Te 4 crystal as a case study, we provide a characterization of its electronic structure by means of angle-resolved photoemission spectroscopy and first-principles calculations. We show that, going away from the Brillouin zone center, bulk band states energetically overlap with the Dirac cone at the Fermi level, thus providing an unwanted as well as hidden contribution to the transport properties of the material. In addition, the comparison between experimental results of the band structure with state-of-the-art simulations, implemented taking into account the number of defects, leads to useful insights on the existing limits in the description of this material.This research was supported in part by the Proget to STAR2(PIR01-00008) of the Italian Ministry of Education, University, and Research.We acknowledge EUROFEL-ROADMAP ESFRI of the Italian Ministry of Education, University, and Research. The density functional theory calculations were supported by the government research assignment for ISPMS SB RAS, Project No. FWRW-20220001. E.V.C. acknowledges support from Saint Petersburg State University (ProjectIDNo.94031444).Peer reviewe

    Examining the generalizability of research findings from archival data

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    This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability—for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Insights into the accuracy of social scientists' forecasts of societal change

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    How well can social scientists predict societal change, and what processes underlie their predictions? To answer these questions, we ran two forecasting tournaments testing the accuracy of predictions of societal change in domains commonly studied in the social sciences: ideological preferences, political polarization, life satisfaction, sentiment on social media, and gender–career and racial bias. After we provided them with historical trend data on the relevant domain, social scientists submitted pre-registered monthly forecasts for a year (Tournament 1; N = 86 teams and 359 forecasts), with an opportunity to update forecasts on the basis of new data six months later (Tournament 2; N = 120 teams and 546 forecasts). Benchmarking forecasting accuracy revealed that social scientists’ forecasts were on average no more accurate than those of simple statistical models (historical means, random walks or linear regressions) or the aggregate forecasts of a sample from the general public (N = 802). However, scientists were more accurate if they had scientific expertise in a prediction domain, were interdisciplinary, used simpler models and based predictions on prior data
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