13,429 research outputs found

    On Ramanujan-Fourier expansions

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    We heuristically study the shifted convolution ∑n≤Xτk(n)τℓ(n+h)\sum_{n\le X} \tau_k(n) \tau_\ell(n+h) using a normalized version of Ramanujan-Fourier expansions for τk(n)\tau_k(n) and verify they produce the expected answer.Comment: six page

    On correlation of the 3-fold divisor function with itself

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    Let ζk(s)=∑n=1∞τk(n)n−s,ℜs>1\zeta^k(s) = \sum_{n=1}^\infty \tau_k(n) n^{-s}, \Re s > 1. We present three conditional results on the ternary additive correlation sum ∑n≤Xτ3(n)τ3(n+h),(h≥1),\sum_{n\le X} \tau_3(n) \tau_3(n+h),\quad (h\ge 1), and give numerical verifications of our method. The first is a conditional proof for the full main term of the above correlation sum for any composite shift 1≤h≤X2/31 \le h \le X^{2/3}, on assuming an averaged level of distribution for the three-fold divisor function τ3(n)\tau_3(n) in arithmetic progressions to level two-thirds. The second is a conditional derivation for the leading order main term asymptotics of this correlation sum, also valid for any composite shift 1≤h≤X2/31 \le h \le X^{2/3}. The third result gives a complete expansion of the polynomial for the full main term for the special case h=1h=1 from both our method and from the delta-method, showing that our answers match. Our method is essentially elementary, especially for the h=1h=1 case, uses congruences, and, as alluded to earlier, gives the same answer as in prior prediction of Conrey and Gonek [Duke Math. J. 107 (3) 2002], previously computed by Ng and Thom [Funct. Approx. Comment. Math. 60(1) 2019], and unpublished heuristic probabilistic arguments of Tao. Our procedure is general and works to give the full main term with a power-saving error term for any correlations of the form ∑n≤Xτk(n)f(n+h)\sum_{n\le X} \tau_k(n) f(n+h), to any composite shift hh, and for a wide class of arithmetic function f(n)f(n).Comment: details on contours shifting added; presentation improved. 46 pages, 2 tables, 4 figure

    A novel function for the Caenorhabditis elegans torsin OOC-5 in nucleoporin localization and nuclear import.

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    Torsin proteins are AAA+ ATPases that localize to the endoplasmic reticular/nuclear envelope (ER/NE) lumen. A mutation that markedly impairs torsinA function causes the CNS disorder DYT1 dystonia. Abnormalities of NE membranes have been linked to torsinA loss of function and the pathogenesis of DYT1 dystonia, leading us to investigate the role of the Caenorhabditis elegans torsinA homologue OOC-5 at the NE. We report a novel role for torsin in nuclear pore biology. In ooc-5-mutant germ cell nuclei, nucleoporins (Nups) were mislocalized in large plaques beginning at meiotic entry and persisted throughout meiosis. Moreover, the KASH protein ZYG-12 was mislocalized in ooc-5 gonads. Nups were mislocalized in adult intestinal nuclei and in embryos from mutant mothers. EM analysis revealed vesicle-like structures in the perinuclear space of intestinal and germ cell nuclei, similar to defects reported in torsin-mutant flies and mice. Consistent with a functional disruption of Nups, ooc-5-mutant embryos displayed impaired nuclear import kinetics, although the nuclear pore-size exclusion barrier was maintained. Our data are the first to demonstrate a requirement for a torsin for normal Nup localization and function and suggest that these functions are likely conserved

    Cynicism about change, work engagement, and job satisfaction of Public Sector Nurses

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    This paper uses the job demands‐resources theory to examine the consequences of changes on nursing work. Data were collected from 220 public sector nurses in Australia to test the model. We conducted a two‐wave data collection process where independent variables (organisational change, workload, job control, nursing administrative stressors, cynicism about organisational change, and demographic variables) were collected in Time 1. The dependent variables (nursing work engagement and job satisfaction) were collected 6 months later. Changes to nursing work were found to cause high workload and an increase of administrative stressors that leads to an increase in nurses’ change cynicism. Job control was needed to cope with the increase in workload and reduction in cynicism about change. Cynicism about organisational change was found to have a direct negative effect on nurses’ engagement which in turn was found to negatively impact job satisfaction. Our contribution to theory and practice arises from the discovery that the connections between organisational change, work environment variables, and job outcomes of nurses are more complicated than previous research suggests. Theoretical and practical implications will be discussed

    Sol-Gel Technology in Enhancing the Filtration of Semi-Volatile Organic Compounds

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    For the past several years, the field of sol-gel technology has undergone remarkable growth in areas ranging from micro-fibers to chemical sensors. Incorporating an organic phase into the colloidal mixture via pre- or post-doping can modify sol-gels, and manipulation of the size of the pores can be used in developing \u27eco-friendly\u27 water filters, particularly for filtering semi-volatile organic compounds in water. In this research project, various forms of sol-gels were made to see which is more efficient for certain semi-volatile chemicals that can be found in diverse sources of water. Organically modified silicates and different structurally sound sol-gels were made to determine which type of sol-gel material provides the most effective water filter

    Percutaneous pulmonary valve implantation alters electrophysiologic substrate

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    BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is first‐line therapy for some congenital heart disease patients with right ventricular outflow tract dysfunction. The hemodynamics improvements after PPVI are well documented, but little is known about its effects on the electrophysiologic substrate. The objective of this study is to assess the short‐ and medium‐term electrophysiologic substrate changes and elucidate postprocedure arrhythmias. METHODS AND RESULTS: A retrospective chart review of patients undergoing PPVI from May 2010 to April 2015 was performed. A total of 106 patients underwent PPVI; most commonly these patients had tetralogy of Fallot (n=59, 55%) and pulmonary insufficiency (n=60, 57%). The median follow‐up time was 28 months (7‐63 months). Pre‐PPVI, 25 patients (24%) had documented arrhythmias: nonsustained ventricular tachycardia (NSVT) (n=9, 8%), frequent premature ventricular contractions (PVCs) (n=6, 6%), and atrial fibrillation/flutter (AF/AFL) (n=10, 9%). Post‐PPVI, arrhythmias resolved in 4 patients who had NSVT (44%) and 5 patients who had PVCs (83%). New arrhythmias were seen in 16 patients (15%): 7 NSVT, 8 PVCs, and 1 AF/AFL. There was resolution at medium‐term follow‐up in 6 (86%) patients with new‐onset NSVT and 7 (88%) patients with new‐onset PVCs. There was no difference in QRS duration pre‐PPVI, post‐PPVI, and at medium‐term follow‐up (P=0.6). The median corrected QT lengthened immediately post‐PPVI but shortened significantly at midterm follow‐up (P<0.01). CONCLUSIONS: PPVI reduced the prevalence of NSVT. The majority of postimplant arrhythmias resolve by 6 months of follow‐up

    Lignin biosynthesis in wheat (Triticum aestivum L.): its response to waterlogging and association with hormonal levels

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    Phylogenetic relationships of wheat C3H and CCoAOMT genes with the homologs from other species. Phylogenetic trees of C3H (A) and CCoAOMT (B) were generated based on nucleic acid sequence similarity of wheat genes with 15 C3H and 19 CCoAOMT genes, respectively, of other monocot and dicot species identified from the NCBI nucleotide database [39] using MEGA program [41], and the trees were inferred using Maximum Likelihood method based on the Tamura-nei model. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test of 500 replicates is shown next to the branches. ●, wheat candidate gene; ▲, genes from dicot species other than Arabidopsis; *, wheat sequence used for the analysis. (PDF 175 kb

    Measuring the Impact of Civic Engagement: Tracking Outcomes in Health, Education, and Economic Security

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    Describes the process of developing the Civic Engagement Measurement System to measure the impact of integrating civic engagement practices into human services programs in the areas of education, healthy living, and economic security. Includes the CEMS
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