Truncated Product Representations for L-Functions in the Hyperelliptic Ensemble

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordWe investigate the approximation of quadratic Dirichlet L-functions over function fields by truncations of their Euler products. We first establish representations for such L-functions as products over prime polynomials times products over their zeros. This is the hybrid formula in function fields. We then prove that partial Euler products are good approximations of an L-function away from its zeros, and that, when the length of the product tends to infinity, we recover the original L-function. We also obtain explicit expressions for the arguments of quadratic Dirichlet L-functions over function fields and for the arguments of their partial Euler products. In the second part of the paper we construct, for each quadratic Dirichlet L-function over a function field, an auxiliary function based on the approximate functional equation that equals the L-function on the critical line. We also construct a parametrized family of approximations of these auxiliary functions, prove the Riemann hypothesis holds for them, and that their zeros are related to those of the associated L-function. Finally, we estimate the counting function for the zeros of this family of approximations, show that these zeros cluster near those of the associated L-function, and that, when the parameter is not too large, almost all the zeros of the approximations are simple.JCA was partially supported by a Research in Pairs - Scheme 4 London Mathematical Society grant. SMG was supported in part by National Science Foundation Grant DMS-1200582. JPK gratefully acknowledges support under EPSRC Programme Grant EP/K034383/1 (LMF: L-Functions and Modular Forms) and a Royal Society Wolfson Research Merit Award

Social job resources as sources of meaningfulness and its effects on nurses’ vigor and emotional exhaustion: a cross-sectional study among spanish nurses

This study investigates the mediating role of psychological meaningfulness among social job resources (i.e., coworkers and supervisor support), vigor, and emotional ex haustion in a nursing context. In spite of progress in under standing which organizational influence affects nurses’ vigor and emotional exhaustion, the psychological mechanisms as sumed to underlie the associations have not been fully ex plored. The sample for this study consisted of 171 nurses from Spanish hospitals (54.4 %) and Primary Care Centers (45.6 %). The mediation model was tested using the bootstrapping procedure. Our findings confirmed that psycho logical meaningfulness fully mediates the impact of social job resources on vigor at work. Moreover, psychological mean ingfulness partially mediated the impact of social job resources on emotional exhaustion. Results suggest that mean ingfulness plays an important role in the connection between job resources, vigor, and emotional exhaustion. The findings contribute to our understanding of the psychological processes that can explain how job resources contribute to the energetic aspect of burnout and engagement among nurses. Providing nurses with more social job resources, such as coworker and supervisor support, could activate their levels of personal meaningfulness and thus enhance their levels of well-being at workThis research was funded by an FPU grant from the Spanish Ministry of Education (AP2010-0099) and by a project from the Spanish Ministry of Economy and Competitiveness (FEM2012-34692

Pancreatic cancer in type 1 and young-onset diabetes: systematic review and meta-analysis

We conducted a systematic review of the risk of pancreatic cancer in people with type I and young-onset diabetes. In three cohort and six case–control studies, the relative risk for pancreatic cancer in people with (vs without) diabetes was 2.00 (95% confidence interval 1.37–3.01) based on 39 cases with diabetes

Dietary Supplementation with Soluble Plantain Non-Starch Polysaccharides Inhibits Intestinal Invasion of Salmonella Typhimurium in the Chicken

Soluble fibres (non-starch polysaccharides, NSP) from edible plants but particularly plantain banana (Musa spp.), have been shown in vitro and ex vivo to prevent various enteric pathogens from adhering to, or translocating across, the human intestinal epithelium, a property that we have termed contrabiotic. Here we report that dietary plantain fibre prevents invasion of the chicken intestinal mucosa by Salmonella. In vivo experiments were performed with chicks fed from hatch on a pellet diet containing soluble plantain NSP (0 to 200 mg/d) and orally infected with S.Typhimurium 4/74 at 8 d of age. Birds were sacrificed 3, 6 and 10 d post-infection. Bacteria were enumerated from liver, spleen and caecal contents. In vitro studies were performed using chicken caecal crypts and porcine intestinal epithelial cells infected with Salmonella enterica serovars following pre-treatment separately with soluble plantain NSP and acidic or neutral polysaccharide fractions of plantain NSP, each compared with saline vehicle. Bacterial adherence and invasion were assessed by gentamicin protection assay. In vivo dietary supplementation with plantain NSP 50 mg/d reduced invasion by S.Typhimurium, as reflected by viable bacterial counts from splenic tissue, by 98.9% (95% CI, 98.1–99.7; P<0.0001). In vitro studies confirmed that plantain NSP (5–10 mg/ml) inhibited adhesion of S.Typhimurium 4/74 to a porcine epithelial cell-line (73% mean inhibition (95% CI, 64–81); P<0.001) and to primary chick caecal crypts (82% mean inhibition (95% CI, 75–90); P<0.001). Adherence inhibition was shown to be mediated via an effect on the epithelial cells and Ussing chamber experiments with ex-vivo human ileal mucosa showed that this effect was associated with increased short circuit current but no change in electrical resistance. The inhibitory activity of plantain NSP lay mainly within the acidic/pectic (homogalacturonan-rich) component. Supplementation of chick feed with plantain NSP was well tolerated and shows promise as a simple approach for reducing invasive salmonellosis

Increased S-nitrosylation and proteasomal degradation of caspase-3 during infection contribute to the persistence of adherent invasive escherichia coli (AIEC) in immune cells

Adherent invasive Escherichia coli (AIEC) have been implicated as a causative agent of Crohn's disease (CD) due to their isolation from the intestines of CD sufferers and their ability to persist in macrophages inducing granulomas. The rapid intracellular multiplication of AIEC sets it apart from other enteric pathogens such as Salmonella Typhimurium which after limited replication induce programmed cell death (PCD). Understanding the response of infected cells to the increased AIEC bacterial load and associated metabolic stress may offer insights into AIEC pathogenesis and its association with CD. Here we show that AIEC persistence within macrophages and dendritic cells is facilitated by increased proteasomal degradation of caspase-3. In addition S-nitrosylation of pro- and active forms of caspase-3, which can inhibit the enzymes activity, is increased in AIEC infected macrophages. This S-nitrosylated caspase-3 was seen to accumulate upon inhibition of the proteasome indicating an additional role for S-nitrosylation in inducing caspase-3 degradation in a manner independent of ubiquitination. In addition to the autophagic genetic defects that are linked to CD, this delay in apoptosis mediated in AIEC infected cells through increased degradation of caspase-3, may be an essential factor in its prolonged persistence in CD patients

Anthropogenic heat flux: advisable spatial resolutions when input data are scarce

Anthropogenic heat flux (QF) may be significant in cities, especially under low solar irradiance and at night. It is of interest to many practitioners including meteorologists, city planners and climatologists. QF estimates at fine temporal and spatial resolution can be derived from models that use varying amounts of empirical data. This study compares simple and detailed models in a European megacity (London) at 500 m spatial resolution. The simple model (LQF) uses spatially resolved population data and national energy statistics. The detailed model (GQF) additionally uses local energy, road network and workday population data. The Fractions Skill Score (FSS) and bias are used to rate the skill with which the simple model reproduces the spatial patterns and magnitudes of QF, and its sub-components, from the detailed model. LQF skill was consistently good across 90% of the city, away from the centre and major roads. The remaining 10% contained elevated emissions and B hot spots ^ representing 30 – 40% of the total city-wide energy. This structure was lost because it requires workday population, spatially resolved building energy consumption and/or road network data. Daily total building and traffic energy consumption estimates from national data were within ± 40% of local values. Progressively coarser spatial resolutions to 5 km improved skill for total Q F , but important features (hot spots, transport network) were lost at all resolutions when residential population controlled spatial variations. The results demonstrate that simple QF models should be applied with conservative spatial resolution in cities that, like London, exhibit time-varying energy use patterns