489 research outputs found

    Contributions to the extension theory in Hilbert spaces

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    This thesis presents solutions to certain problems in the extension theory in Hilbert spaces. Basically there are three main parts of the thesis corresponding to three objects which are studied. The first part consists of chapter 3 and deals with Lagrangian pairs in a pair of Hilbert spaces. In the second part nonnegative linear relations are studied. Finally, in the third part certain results concerning the extension theory of sectorial relations in Hilbert spaces are presented

    PRDM9 sticks its zinc fingers into recombination hotspots and between species.

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    Meiotic recombination events typically cluster within narrow regions of the genome termed hotspots. A series of recent papers reveals that PRDM9, a C2H2-type zinc-finger protein with histone H3 lysine 4 methyltransferase activity, plays a major role in the specification of hotspots. The zinc fingers that contact DNA in a sequence-dependent manner evolve rapidly and are under positive selection, leading to differences in the location of recombination hotspots as well as hybrid sterility

    Islam, Religiosity, and Immigrant Political Action in Western Europe

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    Cataloged from PDF version of article.The issues of migration and immigrant political integration in western democracies have become increasingly intertwined with debates on religion, particularly Islam. To date, however, we have surprisingly little systematic research on how religious beliefs are related to immigrants’ political engagement. In this study, we argue that religion has a capacity to mobilize immigrants politically but the strength of this relationship depends on immigrant generation, religiosity, and the type of religion. Using survey data collected as part of the European Social Survey (ESS) 2002–2010 in 18 West European democracies, our analyses reveal that religion is indeed linked to political engagement of immigrants in a complex way: while belonging to a religion is generally associated with less political participation, exposure to religious institutions appears to have the opposite effect. Moreover, we find that, compared to foreign-born Muslims, second-generation Muslim immigrants are not only more religious and more politically dissatisfied with their host countries, but also that religiosity is more strongly linked to their political engagement. This relationship, however, is limited to uninstitutionalized political action

    Factorized sectorial relations, their maximal-sectorial extensions, and form sums

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    In this paper we consider sectorial operators, or more generally, sectorial relations and their maximal-sectorial extensions in a Hilbert space H. Our particular interest is in sectorial relations S, which can be expressed in the factorized form S=T∗(I+iB)TorS=T(I+iB)T∗, where B is a bounded self-adjoint operator in a Hilbert space K and T:H→K (or T:K→H, respectively) is a linear operator or a linear relation which is not assumed to be closed. Using the specific factorized form of S, a description of all the maximal-sectorial extensions of S is given, along with a straightforward construction of the extreme extensions SF, the Friedrichs extension, and SK, the Kreĭn extension of S, which uses the above factorized form of S. As an application of this construction, we also treat the form sum of maximal-sectorial extensions of two sectorial relations.fi=vertaisarvioitu|en=peerReviewed

    Maternal diet, aging and diabetes meet at a chromatin loop.

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    We have recently demonstrated that exposure to a suboptimal diet during early development leads to abnormal epigenetic regulation of a promoter-enhancer interaction at the gene encoding HNF-4α, a key transcription factor required for pancreatic β-cell differentiation and glucose homeostasis. In addition, our studies revealed that the suboptimal maternal diet amplifies the age-associated epigenetic silencing of this locus. In this research perspective we discuss these novel findings in the context of the growing list of epigenetic mechanisms by which the environment can affect gene activity and emphasize their implications for the understanding of the mechanistic basis of the development of type 2 diabetes with age.This work was supported by the Biotechnology and Biological Sciences Research Council, the British Heart Foundation, the FP6 Epigenome Network of Excellence programme, GlaxoSmithKline, the Nuffield Foundation, the Royal Society, the National Institute for Health Research Cambridge Biomedical Research Centre, and the Medical Research Council Centre for Obesity and Related Metabolic Disease

    Diagnostic Accuracy of Symptoms, Physical Signs, and Laboratory Tests for Giant Cell Arteritis: A Systematic Review and Meta-analysis

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    Importance: Current clinical guidelines recommend selecting diagnostic tests for giant cell arteritis (GCA) based on pretest probability that the disease is present, but how pretest probability should be estimated remains unclear. Objective: To evaluate the diagnostic accuracy of symptoms, physical signs, and laboratory tests for suspected GCA. Data Sources PubMed, EMBASE, and the Cochrane Database of Systematic Reviews were searched from November 1940 through April 5, 2020. Study Selection: Trials and observational studies describing patients with suspected GCA, using an appropriate reference standard for GCA (temporal artery biopsy, imaging test, or clinical diagnosis), and with available data for at least 1 symptom, physical sign, or laboratory test. Data Extraction and Synthesis: Screening, full text review, quality assessment, and data extraction by 2 investigators. Diagnostic test meta-analysis used a bivariate model. Main Outcome(s) and Measures: Diagnostic accuracy parameters, including positive and negative likelihood ratios (LRs). Results: In 68 unique studies (14 037 unique patients with suspected GCA; of 7798 patients with sex reported, 5193 were women [66.6%]), findings associated with a diagnosis of GCA included limb claudication (positive LR, 6.01; 95% CI, 1.38-26.16), jaw claudication (positive LR, 4.90; 95% CI, 3.74-6.41), temporal artery thickening (positive LR, 4.70; 95% CI, 2.65-8.33), temporal artery loss of pulse (positive LR, 3.25; 95% CI, 2.49-4.23), platelet count of greater than 400 × 103/μL (positive LR, 3.75; 95% CI, 2.12-6.64), temporal tenderness (positive LR, 3.14; 95% CI, 1.14-8.65), and erythrocyte sedimentation rate greater than 100 mm/h (positive LR, 3.11; 95% CI, 1.43-6.78). Findings that were associated with absence of GCA included the absence of erythrocyte sedimentation rate of greater than 40 mm/h (negative LR, 0.18; 95% CI, 0.08-0.44), absence of C-reactive protein level of 2.5 mg/dL or more (negative LR, 0.38; 95% CI, 0.25-0.59), and absence of age over 70 years (negative LR, 0.48; 95% CI, 0.27-0.86). Conclusions and Relevance: This study identifies the clinical and laboratory features that are most informative for a diagnosis of GCA, although no single feature was strong enough to confirm or refute the diagnosis if taken alone. Combinations of these symptoms might help direct further investigation, such as vascular imaging, temporal artery biopsy, or seeking evaluation for alternative diagnoses
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