1,752 research outputs found

    Setting the stage: social-environmental and motivational predictors of optimal training engagement

    Get PDF
    In this paper, we will firstly explore the central tenets of SDT. Research that has examined the social-environmental and motivation-related correlates of optimal training, performance and health-related engagement through the theoretical lens of SDT will be reviewed. Drawing from SDT-driven work undertaken in educational, sport and dance settings, we will draw conclusions and suggest future directions from a research and applied perspective

    Flow-weighted values of runoff tracers (δ18O, DOC, Ba, alkalinity) from the six largest Arctic rivers

    Get PDF
    Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 35 (2008): L18606, doi:10.1029/2008GL035007.We present new flow-weighted data for δ 18OH2O, dissolved organic carbon (DOC), dissolved barium and total alkalinity from the six largest Arctic rivers: the Ob', Yenisey, Lena, Kolyma, Yukon and Mackenzie. These data, which can be used to trace runoff, are based upon coordinated collections between 2003 and 2006 that were temporally distributed to capture linked seasonal dynamics of river flow and tracer values. Individual samples indicate significant variation in the contributions each river makes to the Arctic Ocean. Use of these new flow-weighted estimates should reduce uncertainties in the analysis of freshwater transport and fate in the upper Arctic Ocean, including the links to North Atlantic thermohaline circulation, as well as regional water mass analysis. Additional improvements should also be possible for assessing the mineralization rate of the globally significant flux of terrigenous DOC contributed to the Arctic Ocean by these major rivers.Supported by the U.S. National Science Foundation (OPP-0229302), the U.S. Geological Survey and the Water Resources Division of Canada’s Department of Indian Affairs and Northern Development

    Representations of twisted Yangians of types B, C, D: I

    Get PDF
    We initiate a theory of highest weight representations for twisted Yangians of types B, C, D and we classify the finite-dimensional irreducible representations of twisted Yangians associated to symmetric pairs of types CI, DIII and BCD0

    Design of the HIV Prevention Trials Network (HPTN) Protocol 054: A cluster randomized crossover trial to evaluate combined access to Nevirapine in developing countries

    Get PDF
    HPTN054 is a cluster randomized trial designed to compare two approaches to providing single dose nevirapine to HIV-seropositive mothers and their infants to prevent mother-to-child transmission of HIV in resource limited settings. A number of challenging issues arose during the design of this trial. Most importantly, the need to achieve high participation rates among pregnant, HIV-seropositive women in selected prenatal care clinics led us to develop a method of collecting anonymous and unlinked information on a key surrogate endpoint instead of pursuing linked and identified information on a clinical endpoint. In addition, since group counseling is the standard model for prenatal care in sub-Saharan Africa, the prenatal care clinic serves as the unit of randomization. However, constraints on the number of suitable clinics and other logistical difficulties necessitated a unique type of hybrid parallel/stepped wedge cluster randomized design in which some clinics cross over between the two treatment modalities and some do not. We describe the design for the HPTN054 trial with an emphasis on the logistic and statistical features that allowed us to address these issues. We also provide some general statistical results that are useful for computing power in parallel, crossover, stepped wedge or mixed designs of cluster randomized trials

    Circular RNAs as novel regulators of β-cell functions in normal and disease conditions.

    Get PDF
    There is strong evidence for an involvement of different classes of non-coding RNAs, including microRNAs and long non-coding RNAs, in the regulation of β-cell activities and in diabetes development. Circular RNAs were recently discovered to constitute a substantial fraction of the mammalian transcriptome but the contribution of these non-coding RNAs in physiological and disease processes remains largely unknown. The goal of this study was to identify the circular RNAs expressed in pancreatic islets and to elucidate their possible role in the control of β-cells functions. We used a microarray approach to identify circular RNAs expressed in human islets and searched their orthologues in RNA sequencing data from mouse islets. We then measured the level of four selected circular RNAs in the islets of different Type 1 and Type 2 diabetes models and analyzed the role of these circular transcripts in the regulation of insulin secretion, β-cell proliferation, and apoptosis. We identified thousands of circular RNAs expressed in human pancreatic islets, 497 of which were conserved in mouse islets. The level of two of these circular transcripts, circHIPK3 and ciRS-7/CDR1as, was found to be reduced in the islets of diabetic db/db mice. Mimicking this decrease in the islets of wild type animals resulted in impaired insulin secretion, reduced β-cell proliferation, and survival. ciRS-7/CDR1as has been previously proposed to function by blocking miR-7. Transcriptomic analysis revealed that circHIPK3 acts by sequestering a group of microRNAs, including miR-124-3p and miR-338-3p, and by regulating the expression of key β-cell genes, such as Slc2a2, Akt1, and Mtpn. Our findings point to circular RNAs as novel regulators of β-cell activities and suggest an involvement of this novel class of non-coding RNAs in β-cell dysfunction under diabetic conditions

    Scrt1, a transcriptional regulator of β-cell proliferation identified by differential chromatin accessibility during islet maturation.

    Get PDF
    Glucose-induced insulin secretion, a hallmark of mature β-cells, is achieved after birth and is preceded by a phase of intense proliferation. These events occurring in the neonatal period are decisive for establishing an appropriate functional β-cell mass that provides the required insulin throughout life. However, key regulators of gene expression involved in functional maturation of β-cells remain to be elucidated. Here, we addressed this issue by mapping open chromatin regions in newborn versus adult rat islets using the ATAC-seq assay. We obtained a genome-wide picture of chromatin accessible sites (~ 100,000) among which 20% were differentially accessible during maturation. An enrichment analysis of transcription factor binding sites identified a group of transcription factors that could explain these changes. Among them, Scrt1 was found to act as a transcriptional repressor and to control β-cell proliferation. Interestingly, Scrt1 expression was controlled by the transcriptional repressor RE-1 silencing transcription factor (REST) and was increased in an in vitro reprogramming system of pancreatic exocrine cells to β-like cells. Overall, this study led to the identification of several known and unforeseen key transcriptional events occurring during β-cell maturation. These findings will help defining new strategies to induce the functional maturation of surrogate insulin-producing cells

    Multiplicative slices, relativistic Toda and shifted quantum affine algebras

    Full text link
    We introduce the shifted quantum affine algebras. They map homomorphically into the quantized KK-theoretic Coulomb branches of 3d N=43d\ {\mathcal N}=4 SUSY quiver gauge theories. In type AA, they are endowed with a coproduct, and they act on the equivariant KK-theory of parabolic Laumon spaces. In type A1A_1, they are closely related to the open relativistic quantum Toda lattice of type AA.Comment: 125 pages. v2: references updated; in section 11 the third local Lax matrix is introduced. v3: references updated. v4=v5: 131 pages, minor corrections, table of contents added, Conjecture 10.25 is now replaced by Theorem 10.25 (whose proof is based on the shuffle approach and is presented in a new Appendix). v6: Final version as published, references updated, footnote 4 adde

    Small RNAs derived from tRNA fragmentation regulate the functional maturation of neonatal β cells.

    Get PDF
    tRNA-derived fragments (tRFs) are an emerging class of small non-coding RNAs with distinct cellular functions. Here, we studied the contribution of tRFs to the regulation of postnatal β cell maturation, a critical process that may lead to diabetes susceptibility in adulthood. We identified three tRFs abundant in neonatal rat islets originating from 5' halves (tiRNA-5s) of histidine and glutamate tRNAs. Their inhibition in these islets reduced β cell proliferation and insulin secretion. Mitochondrial respiration was also perturbed, fitting with the mitochondrial enrichment of nuclear-encoded tiRNA-5 <sup>HisGTG</sup> and tiRNA-5 <sup>GluCTC</sup> . Notably, tiRNA-5 inhibition reduced Mpc1, a mitochondrial pyruvate carrier whose knock down largely phenocopied tiRNA-5 inhibition. tiRNA-5 <sup>HisGTG</sup> interactome revealed binding to Musashi-1, which was essential for the mitochondrial enrichment of tiRNA-5 <sup>HisGTG</sup> . Finally, tiRNA-5s were dysregulated in the islets of diabetic and diabetes-prone animals. Altogether, tiRNA-5s represent a class of regulators of β cell maturation, and their deregulation in neonatal islets may lead to diabetes susceptibility in adulthood

    A cost comparison of electronic and hybrid data collection systems in Ontario during pandemic and seasonal influenza vaccination campaigns

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>During the pandemic (H1N1) 2009 influenza vaccination campaign, health regions in Canada collected client-level immunization data using fully electronic or hybrid systems, with the latter comprising both electronic and paper-based elements. The objective of our evaluation was to compare projected five-year costs associated with implementing these systems in Ontario public health units (PHUs) during pandemic and seasonal influenza vaccination campaigns.</p> <p>Methods</p> <p>Six PHUs provided equipment and staffing costs during the pandemic (H1N1) 2009 influenza vaccination campaign and staffing algorithms for seasonal campaigns. We standardized resources to population sizes 100,000, 500,000 and 1,000,000, assuming equipment lifetime of five years and public health vaccine administration rates of 18% and 2.5% for H1N1 and seasonal campaigns, respectively. Two scenarios were considered: Year 1 pandemic and Year 1 seasonal campaigns, each followed by four regular influenza seasons. Costs were discounted at 5%.</p> <p>Results</p> <p>Assuming a Year 1 pandemic, the five-year costs per capita for the electronic system decrease as PHU population size increases, becoming increasingly less costly than hybrid systems (4.33vs.4.33 vs. 4.34 [100,000], 4.17vs.4.17 vs. 4.34 [500,000], 4.12vs.4.12 vs. 4.34 [1,000, 000]). The same trend is observed for the scenario reflecting five seasonal campaigns, with the electronic system being less expensive per capita than the hybrid system for all population sizes (1.93vs.1.93 vs. 1.95 [100,000], 1.91vs.1.91 vs. 1.94 [500,000], 1.87vs.1.87 vs. 1.94 [1,000, 000]). Sensitivity analyses identified factors related to nurse hours as affecting the direction and magnitude of the results.</p> <p>Conclusions</p> <p>Five-year cost projections for electronic systems were comparable or less expensive than for hybrid systems, at all PHU population sizes. An intangible benefit of the electronic system is having data rapidly available for reporting.</p

    Effects of plant extracts and essential oils as feed supplements on quality and microbial traits of rabbit meat

    Get PDF
    [EN] The effects of dietary supplementation of onion, cranberry,  strawberry and essentials oils on meat quality were analysed. Five groups of 48 Grimaud female weaned rabbits received the supplemented or the control ration; the experimental unit was a cage of 6 rabbits. Each experimental diet contained 10 ppm of added active ingredients.  Rabbits were fed with the experimental diets for 4 wk before determining slaughter and carcass traits and determining the pH at 1 and 24 h post mortem (pHu) of the Longissimus dorsi (LD) and the Biceps femoris (BF) muscle, left and right, respectively. Cooking loss, drip loss and L*, a* and b* color parameters were obtained of the right LD and for ground meat and antioxidant status (TBARS, DNPH, Folin Ciocalteu). Only the pHu of the LD muscle for the strawberry supplemented group was significantly lower when compared to the control group (P=0.04). However, we note that for the pH of the LD, the average was less than 6 for the meat of animals who received a diet enriched in polyphenols, compared to the control group. Plant extract supplementation did not influence meat quality traits, growth performance or oxidative stability. But under aerobic and anaerobic conditions, our results indicate that diet supplementation with extracts rich in polyphenols, especially with essential oils, had a small bot sporadic positive effect in reducing bacterial microflora compared to the control group (P<0.05). In conclusion, plant extracts and essential oils can be used in a rabbit diet without adverse effects on performance and meat quality traits. This effect could be optimized by investigating higher doses.Kone, AP.; Cinq-Mars, D.; Desjardins, Y.; Guay, F.; Gosselin, A.; Saucier, L. (2016). Effects of plant extracts and essential oils as feed supplements on quality and microbial traits of rabbit meat. World Rabbit Science. 24(2):107-119. doi:10.4995/wrs.2016.3665SWORD107119242AOAC. 1995. Official methods of Analysis of the Association of Official Analytical Chemists, 15th Ed. AOAC, Arlington, VA. USA.Bízková Z., Tumová E. 2010. Physical characteristics of rabbit meat: a review. Scienta Agriculturae Bohemica., 4: 236-241.Botsoglou, N. A., Govaris, A., Botsoglou, E. N., Grigoropoulou, S. H., & Papageorgiou, G. (2003). Antioxidant Activity of Dietary Oregano Essential Oil and α-Tocopheryl Acetate Supplementation in Long-Term Frozen Stored Turkey Meat. Journal of Agricultural and Food Chemistry, 51(10), 2930-2936. doi:10.1021/jf021034oBrichta-Harhay, D. M., Arthur, T. M., Bosilevac, J. M., Guerini, M. N., Kalchayanand, N., & Koohmaraie, M. (2007). Enumeration of Salmonella and Escherichia coli O157:H7 in ground beef, cattle carcass, hide and faecal samples using direct plating methods†. Journal of Applied Microbiology, 103(5), 1657-1668. doi:10.1111/j.1365-2672.2007.03405.xCardinali R., Dal Bosco A., Mugnai C., Mattioli S., Ruggeri S., Dalle Zotte A., Sartori A., Cullere M., Castellini C. 2012. Effect of different dietary aromatic essences on meat quality of rabbit. In Proc.: 10th World Rabbit Congress, 3-6 September, 2012, Sharm El-Sheikh, Egypt. 6: 925- 929.CIE. 2004. International Commission on Illumination. Colorimetry. Publication 15. 3rd edition, Bureau Central de la CIE.Combes S. 2004. Valeur nutritive de la viande de lapin. INRA Prod. Anim., 17: 373-383.Fraysse J.L., Darre A. 1989. Production des viandes. Volume I. Ed Technique et documentation. Lavoisier. Paris, pp. 374.Greer G.G., 1989. Red meat, poultry, and fish. In: McKellar R.C. (ed). Enzymes of psychotrophs in raw food. CRC Press, Inc., Boca Raton, FL, USA, 267-292.King J.C., Black R.E., Doyle M.P., Fritsche K.L., Halbrook B.H., Levander O.A., Meydani S.N., Walker W.A., Woteki C.E. 2000. Foodborne illnesses and nutritional status: a statement from an american society for nutritional sciences working group. J. Nutr., 130: 2613-2617.Magdelaine P. 2003. Économie et avenir des filières avicoles et cunicoles. INRA Prod. Anim., 16: 349-356.Peiretti, P. G., & Meineri, G. (2008). Effects on growth performance, carcass characteristics, and the fat and meat fatty acid profile of rabbits fed diets with chia (Salvia hispanica L.) seed supplements. Meat Science, 80(4), 1116-1121. doi:10.1016/j.meatsci.2008.05.003Pla M. 1999. Carcass and meat quality of growing rabbits under high ambient temperature using high fat diets. In: Testik A., Baselga M. (ed). 2nd International Conference on rabbit production in hot climates. Ciheam-Iamz Adana (Turquía). Cahiers Options Méditerranéennes, 41: 93-98.Rasmussen A.J., Andersson M. 1996. New method for determination of drip loss in pork muscles. In Proc.: 42nd International Congress of Meat Science and Technology,1-6 September, 1996. Lillehammer, Norway. 286-287.Rotolo, L., Gai, F., Nicola, S., Zoccarato, I., Brugiapaglia, A., & Gasco, L. (2013). Dietary Supplementation of Oregano and Sage Dried Leaves on Performances and Meat Quality of Rabbits. Journal of Integrative Agriculture, 12(11), 1937-1945. doi:10.1016/s2095-3119(13)60631-0Salvini S., Parpinel M., Gnagnarella P., Maisonneuve P., Turrini A. 1998. Banca dati di composizione degli alimenti per studi epidemiologici in Italia. Ed. Istituto Superiore di Oncologia, Genova, Italy.SAS. 2002. SAS/STAT User's Guide (Release 9.1). SAS Institute, Inc., Cary NC, USA.Subramanian K.N., Padmanaban G., Sarma P.S. 1965. Folin-Ciocalteu reagent for the estimation of siderochromes. Anal. Biochem., 12: 106-112. doi:10.1016/0003-2697(65)90147-Thomas M.K., Majowicz S.E, Pollari F., Sockett P.N. 2008. Burden of acute gastrointestinal illness in Canada, 1999-2007: Interim summary of NSAGI activities. Canada Communicable Disease Report, 34: 8-13
    corecore