725 research outputs found

    A new perspective on the Frenkel-Zhu fusion rule theorem

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    In this paper we prove a formula for fusion coefficients of affine Kac-Moody algebras first conjectured by Walton [Wal2], and rediscovered in [Fe]. It is a reformulation of the Frenkel-Zhu affine fusion rule theorem [FZ], written so that it can be seen as a beautiful generalization of the classical Parasarathy-Ranga Rao-Varadarajan tensor product theorem [PRV].Comment: 19 pages, no figures, uses conm-p-l.cls style fil

    Student-generated e-learning for clinical education

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    Background Within clinical education, e-learning facilitates a standardised learning experience to augment the clinical experience while enabling learner and teacher flexibility. With the shift of students from consumers to creators, student-generated content is expanding within higher education; however, there is sparse literature evaluating the impact of student-developed e-learning within clinical education. The aim of this study was to implement and evaluate a student-developed e-learning clinical module series within ambulatory care clinical pharmacy experiences. Methods Three clinical e-learning modules were developed by students for use prior to clinical experiences. E-learning modules were created by fourth-year professional pharmacy students and reviewed by pharmacy faculty members. A pre-/post-assessment was performed to evaluate knowledge comprehension before and after participating in the e-learning modules. Additionally, a survey on student perceptions of this educational tool was performed at the end of the clinical experience. There is sparse literature evaluating the impact of student-developed e-learning within clinical education Results Of the 31 students eligible for study inclusion, 94 per cent participated in both the pre- and post-assessments. The combined post-assessment score was significantly improved after participating in the student-developed e-learning modules (p = 0.008). The student perception survey demonstrated positive perceptions of e-learning within clinical education. Discussion Student-generated e-learning was able to enhance knowledge and was positively perceived by learners. As e-learning continues to expand within health sciences education, students can be incorporated into the development and execution of this educational tool

    A Hybrid Dynamical–Statistical Downscaling Technique. Part I: Development and Validation of the Technique

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    Abstract In this study (Part I), the mid-twenty-first-century surface air temperature increase in the entire CMIP5 ensemble is downscaled to very high resolution (2 km) over the Los Angeles region, using a new hybrid dynamical–statistical technique. This technique combines the ability of dynamical downscaling to capture finescale dynamics with the computational savings of a statistical model to downscale multiple GCMs. First, dynamical downscaling is applied to five GCMs. Guided by an understanding of the underlying local dynamics, a simple statistical model is built relating the GCM input and the dynamically downscaled output. This statistical model is used to approximate the warming patterns of the remaining GCMs, as if they had been dynamically downscaled. The full 32-member ensemble allows for robust estimates of the most likely warming and uncertainty resulting from intermodel differences. The warming averaged over the region has an ensemble mean of 2.3°C, with a 95% confidence interval ranging from 1.0° to 3.6°C. Inland and high elevation areas warm more than coastal areas year round, and by as much as 60% in the summer months. A comparison to other common statistical downscaling techniques shows that the hybrid method produces similar regional-mean warming outcomes but demonstrates considerable improvement in capturing the spatial details. Additionally, this hybrid technique incorporates an understanding of the physical mechanisms shaping the region's warming patterns, enhancing the credibility of the final results

    Structural disorder in (Bi,M)2(Fe,Mn,Bi)2O6+x (M = Na or K) pyrochlores seen from reverse Monte Carlo analysis of neutron total scattering

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    The average structures of the polycrystalline pyrochlores (Na0.60Bi1.40)(Fe1.06Mn0.17Bi0.77)O6.87 and (K0.24Bi1.51)(Fe1.07Mn0.15Bi0.78)O6.86 can be refined through Rietveld refinement against Bragg scattering data using cubic space group Fd3 ̅m, with off-centred 96h and 32e positions describing the A2Oʹ network. Investigation of their local structures through neutron total scattering confirms the extent of disorder within these materials, and furthermore shows significant deviation from the average structure, which is not accounted for through analysis of Bragg data alone. Reverse Monte Carlo (RMC) analysis with a 6 × 6 × 6 supercell was used to model accurately this local disorder, revealing ellipsoidal distributions for A-site potassium, distinctly different to the hollow torus-shaped distributions for the sodium and bismuth cations. It is shown through bond valence sum analysis that whilst these atomic displacements allow for the steric preferences of Bi3+, they are also necessary to satisfy the valence of both the bismuth and the alkali metals on the A sites. Analysis of the final RMC configuration showed the BO6 octahedra for the separate B site metals to be more regular (O–B–O ≈ 90°) than those in the Rietveld model (O–B–O ≈ 85/95°) which describes an average of the three different environments

    Evaluating Total Environmental Impact for a Computing Infrastructure

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    In this paper we outline the results of a project to evaluate the total climate/carbon impact of a digital research infrastructure for a defined snapshot period. We outline the carbon model used to calculate the impact and the data collected to quantify that impact for a defined set of resources. We discuss the variation in potential impact across both the active and embodied carbon for computing hardware and produce a range of estimates on the amount of carbon equivalent climate impact for the snapshot period

    Caenorhabditis elegans AF4/FMR2 Family Homolog affl-2 Regulates Heat-Shock-Induced Gene Expression

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    To mitigate the deleterious effects of temperature increases on cellular organization and proteotoxicity, organisms have developed mechanisms to respond to heat stress. In eukaryotes, HSF1 is the master regulator of the heat shock transcriptional response, but the heat shock response pathway is not yet fully understood. From a forward genetic screen for suppressors of heat-shock-induced gene expression in Caenorhabditis elegans, we found a new allele of hsf-1 that alters its DNA-binding domain, and we found three additional alleles of sup-45, a previously molecularly uncharacterized genetic locus. We identified sup-45 as one of the two hitherto unknown C. elegans orthologs of the human AF4/FMR2 family proteins, which are involved in regulation of transcriptional elongation rate. We thus renamed sup-45 as affl-2 (AF4/FMR2-Like). Through RNA-seq, we demonstrated that affl-2 mutants are deficient in heat-shock-induced transcription. Additionally, affl-2 mutants have herniated intestines, while worms lacking its sole paralog (affl-1) appear wild type. AFFL-2 is a broadly expressed nuclear protein, and nuclear localization of AFFL-2 is necessary for its role in heat shock response. affl-2 and its paralog are not essential for proper HSF-1 expression and localization after heat shock, which suggests that affl-2 may function downstream of, or parallel to, hsf-1. Our characterization of affl-2 provides insights into the regulation of heat-shock-induced gene expression to protect against heat stress

    Caenorhabditis elegans AF4/FMR2 Family Homolog affl-2 Regulates Heat-Shock-Induced Gene Expression

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    To mitigate the deleterious effects of temperature increases on cellular organization and proteotoxicity, organisms have developed mechanisms to respond to heat stress. In eukaryotes, HSF1 is the master regulator of the heat shock transcriptional response, but the heat shock response pathway is not yet fully understood. From a forward genetic screen for suppressors of heat-shock-induced gene expression in Caenorhabditis elegans, we found a new allele of hsf-1 that alters its DNA-binding domain, and we found three additional alleles of sup-45, a previously molecularly uncharacterized genetic locus. We identified sup-45 as one of the two hitherto unknown C. elegans orthologs of the human AF4/FMR2 family proteins, which are involved in regulation of transcriptional elongation rate. We thus renamed sup-45 as affl-2 (AF4/FMR2-Like). Through RNA-seq, we demonstrated that affl-2 mutants are deficient in heat-shock-induced transcription. Additionally, affl-2 mutants have herniated intestines, while worms lacking its sole paralog (affl-1) appear wild type. AFFL-2 is a broadly expressed nuclear protein, and nuclear localization of AFFL-2 is necessary for its role in heat shock response. affl-2 and its paralog are not essential for proper HSF-1 expression and localization after heat shock, which suggests that affl-2 may function downstream of, or parallel to, hsf-1. Our characterization of affl-2 provides insights into the regulation of heat-shock-induced gene expression to protect against heat stress

    Design of Drug-Induced Diseases Elective Utilizing Active Learning

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    Objectives To describe active learning utilized in a drug-induced diseases (DID) elective and determine inter-rater reliability of the assessment rubric for oral case-based presentations. Methods The design of this DID elective focuses on problem-based learning to enhance students’ critical thinking and problem-solving skills pertaining to the treatment of inducible diseases and general medicine. Each class incorporates active learning, utilization of drug information resources, and group work. The primary course assessment is student developed oral case-based presentations evaluated with a standard rubric. Results The intra-class correlation coefficient (ICC) was calculated amongst evaluators to assess the inter-rater reliability of the DID rubric for 21 case-based presentations during the Fall 2013 semester. Composite scores for the case-based presentations demonstrated good inter-rater reliability with an ICC of 0.628. Conclusions Teaching methods utilizing active learning are described for this DID elective. The rubric for the student developed oral case-based presentations demonstrated good inter-rater reliability amongst evaluators and could be modified for use in other professional courses

    Use of titanocalix[4]arenes in the ring opening polymerization of cyclic esters

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    The known dichloride complexes [TiCl2L(O)2(OR)2] (type I: R = Me (1), n-Pr (2) and n-pentyl (3); L(OH)2(OR)2 = 1,3-dialkyloxy-p-tert-butylcalix[4]arene), together with the new complexes {[TiL(O)3(OR)]2(μ-Cl)2}·6MeCN (R = n-decyl (4·6MeCN)), and [Ti(NCMe)Cl(L(O)3(OR))]·MeCN (type II: R = Me, 5·MeCN) are reported. Attempts to prepare type II for R = n-Pr and n-pentyl using [TiCl4] resulted in the complexes {[TiL(O)3(On-propyl)]2(μ-Cl)(μ-OH)} 6·7MeCN and {[TiL(O)3(On-pentyl)]2(μ-Cl)(μ-OH)}·7.5MeCN (7·7.5MeCN), respectively; use of [TiCl4(THF)2] resulted in a co-crystallized THF ring-opened product [Ti(NCMe)(μ3-O)L(O)4TiCl(O(CH2)4Cl)]2-2[TiCl(NCMe)(L(O)3(On-Pr))]·11MeCN (8·11MeCN). The molecular structures of 2·2MeCN, 4·6MeCN, and 5·MeCN together with the hydrolysis products {[TiL(O)3(OR)]2(μ-Cl)(μ-OH)} (R = n-Pr 6·7MeCN; n-pentyl, 7·7.5MeCN, 9·9MeCN); R = n-decyl 10·8.5MeCN) and that of the ring opened product 8·11MeCN and the co-crystallized species [Ti2(OH)Cl(L(O)3(OR))][L(OH)2(OR)2]·2.85(C2H3N)·0.43(H2O) (R = n-pentyl, 11·2.85(C2H3N)·0.43(H2O)) are reported. Type I and II complexes have been screened for their ability to act as catalysts in the ring opening polymerization (ROP) of ϵ-caprolactone (ϵ-CL), δ-valerolactone (δ-VL), ω-pentadecalactone (ω-PDL) and rac-lactide (r-LA), both with and without benzyl alcohol present and either under N2 or in air. The copolymerization of ϵ-CL with δ-VL and with r-LA has also been investigated. For the ROP of ϵ-CL, all performed efficiently (>99% conversion) at 130 °C over 24 h both under N2 and in air, whilst over 1 h, for the type I complexes the trend was 3 > 2 > 1 but all were poor (≤12% conversion). By contrast, 5 over 1 h at 130 °C was highly active (85% conversion). At 80 °C, the activity trend followed the order 5 ≈ 4 > 3 > 2 > 1. For δ-VL, at 80 °C the activity trend 5 ≈ 4 > 1 > 2 > 3 was observed. ROP of the larger ω-PDL was only possible using 5 at 130 °C over 24 h with moderate activity (48% conversion). For r-LA, only low molecular weight products were obtained, whilst for the co-polymerization of ϵ-CL with δ-VL using 5, high activity was observed at 80 °C affording a polymer of molecular weight >23,000 Da and with equal incorporation of each monomer. In the case of ϵ-CL/r-LA co-polymerization using 5 either under N2 or air, the polymerization was more sluggish and only 65% conversion of CL was observed and the resultant co-polymer had 65:35 incorporation. Complex 5 could also be supported on silica, however this system was not as active as its homogeneous counterpart. Finally, the activity of these complexes is compared with that of three benchmark species: a di-phenolate Ti compound {TiCl2(2,2′-CH3CH[4,6-(t-Bu)2C6H2O]2)} (12) and a previously reported NO2-containing titanocalix[4]arene catalyst, namely cone-5,17-bis-tert-butyl-11,23-dinitro-25,27-dipropyloxy-26,28-dioxo-calix[4]arene titanium dichloride (13), as well as [Ti(Oi-Pr)4]; the parent calixarenes were also screened
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