653 research outputs found

    Steady State Analysis Of Single Phase IPM Motors By D-Q Harmonic Balance Method

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    A concise steady-state analysis of a single-phase line-start permanent magnet (SPLSPM) machine is conducted from a developed d-q model using the d-q harmonic balance technique. The d-q model was developed in rotor reference frame from a phase variable model of the machine. SPLSPM whose performance indices were characterized by high torque ripples has detailed analysis docile mostly in computer simulations quite unlike the three-phase types. The main cause is not far-fetched, it was due to nonexistence of precise mathematical model in d-q rotor frame of the motor due to the unbalanced field winding, the rotor saliency and the presence of the capacitor in the auxiliary windings. Even after model has been developed, the simple traditional procedure of setting all time varying component to zero for steady-state analysis fails because the rotor position dependence on the inductance expressions could not be eliminated. The d-q harmonic-balance technique was then applied. An important feature of the harmonic balance technique was that it decoupled all equations to simple sine waveforms in a style that resembled Fourier series. Results yield torque pulsation, current and load characteristics in the steady state

    The Pivotal Role of Regulatory T Cells in the Regulation of Innate Immune Cells

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    The distinction between innate and adaptive immunity is one of the basic tenets of immunology. The co-operation between these two arms of the immune system is a major determinant of the resistance or susceptibility of the host following pathogen invasion. Hence, this interactive co-operation between cells of the innate and adaptive immunity is of significant interest to immunologists. The sub-population of CD4+ T cells with regulatory phenotype (regulatory T cells; Tregs), which constitute a part of the adaptive immune system, have been widely implicated in the regulation of the immune system and maintenance of immune homeostasis. In the last two decades, there has been an explosion in research describing the role of Tregs and their relevance in several immunopathologies ranging from inflammation to cancer. The majority of these studies focus on the role of Tregs on the cells of the adaptive immune system. Recently, there is significant interest in the role of Tregs on cells of the innate immune system. In this review, we examine the literature on the role of Tregs in immunology. Specifically, we focus on the emerging knowledge of Treg interaction with dendritic cells, macrophages, neutrophils, and γΎ T cells. We highlight this interaction as an important link between innate and adaptive immune systems which also indicate the far-reaching role of Tregs in the regulation of immune responses and maintenance of self-tolerance and immune homeostasis

    Enhanced trimethylation of histone H3 mediates impaired expression of hepatic glucose 6-phosphatase expression in offspring from rat dams exposed to hypoxia during pregnancy

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    Given that hepatic glucose 6-phosphatase (G6Pase, involved in gluconeogenesis) has been demonstrated to be altered long term in animal models of intrauterine growth restriction (IUGR), we hypothesized that hypoxia in utero may regulate G6Pase expression via epigenetic mechanisms. To address this further, a rat model of maternal hypoxia leading to IUGR and impaired liver growth was utilized. In the 12-month-old male offspring of pregnant rat dams exposed to 11.5% atmospheric oxygen from gestational day (gd) 15 to gd 21, nonfasting glucose was lower in association with decreased hepatic G6Pase messenger RNA and protein levels. This was concomitant with enhanced methylation of histone H3 [K9] surrounding the promoter of G6Pase. Moreover, when McA-RH7777 hepatoma cells were exposed to various concentrations of oxygen for 48 hours, we observed an oxygen-dependent decrease in G6Pase expression associated with enhanced histone H3 [K9] methylation. Collectively, these results indicate that hypoxia directly and indirectly impairs G6Pase expression through enhanced methylation of histone H3 [K9]. © The Author(s) 2013

    Registration of ‘Purple Bounty’ and ‘Purple Prosperity’ hairy vetch

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    The hairy vetch (Vicia villosa Roth) cultivars ‘Purple Bounty’ (Reg. no. CV-12, PI 648342) and ‘Purple Prosperity’ (Reg. no. CV-11, PI 654047) were released in 2007 and 2008, respectively, by the USDA–ARS in collaboration with the Rodale Institute and the agricultural experiment stations of Pennsylvania State University and Cornell University. Hairy vetch is a commonly used annual legume cover crop grown for its cold tolerance, fast growth, large biomass production, and ability to fix N2. However, this species has not been selected for the traits needed to optimize its use as a cover crop. Our breeding program focused on developing a cultivar that was both early flowering and had adequate winter survival and therefore adapted to mechanical termination in organic no-till production in the U.S. Northeast and Mid-Atlantic. Purple Bounty and Purple Prosperity were developed between 1998 and 2005 using recurrent selection at nurseries in Beltsville and Keedysville, MD. In 2005–2006, selections were evaluated against commercial checks for flowering time in Maryland and Pennsylvania, and in the 2006–2007 and 2007–2008 seasons they were evaluated in 10 locations (12 total site-years) across the United States for winter survival. Purple Bounty and Purple Prosperity both flowered earlier than the commercial material against which they were tested (significance depended on the date and site); Purple Bounty was the earlier flowering of the two cultivars. Purple Bounty and Purple Prosperity also had equivalent or improved winter survival compared with ‘AU Early Cover’, an early-maturing cultivar developed in the southern United States, at all test locations. Purple Prosperity is no longer commercially available, but Purple Bounty is currently licensed and distributed by Allied Seed (Nampa, ID)

    Recent advances in acoustic diagnostics for electrochemical power systems

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    Acknowledgments The authors would like to gratefully acknowledge the EPSRC for supporting the electrochemical research in the Electrochemical Innovation Lab (EP/R020973/1; EP/R023581/1; EP/N032888/1; EP/R023581/1; EP/P009050/1; EP/M014371/1; EP/M009394; EP/L015749/1; EP/K038656/1) and Innovate UK for funding the VALUABLE project (Grant No. 104182). The authors would also like to acknowledge the Royal Academy of Engineering for funding Robinson and Shearing through ICRF1718\1\34 and CiET1718 respectively and the Faraday Institution (EP/S00353/1, Grant Nos. FIRG003, FIRG014). The authors also acknowledge the STFC for supporting Shearing and Brett (ST/K00171X/1) and ACEA for supporting ongoing research at the EIL. Support from the National Measurement System of the UK Department for Business, Energy and Industrial Strategy is also gratefully acknowledged.Peer reviewedPublisher PD

    Lack of confidence among trainee doctors in the management of diabetes: the Trainees Own Perception of Delivery of Care (TOPDOC) Diabetes Study

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    Background: There is an increased prevalence of diabetes. Doctors in training, irrespective of specialty, will have patients with diabetes under their care

    Maternal Attachment Style and Responses to Adolescents’ Negative Emotions: The Mediating Role of Maternal Emotion Regulation

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Parenting: Science and Practice on November 11, 2014, available online: https://doi.org/10.1080/15295192.2014.972760 .Objective. Previous research has examined the developmental consequences, particularly in early childhood, of parents’ supportive and unsupportive responses to children’s negative emotions. Much less is known about factors that explain why parents respond in ways that may support or undermine their children’s emotions, and even less is known about how these parenting processes unfold with adolescents. In the present study, researchers examined the associations between mothers’ attachment styles and their distress, harsh, and supportive responses to their adolescents’ negative emotions two years later and whether these links were mediated by maternal emotion regulation difficulties. Design. Mothers in a longitudinal study (n = 230) reported on their attachment style, difficulties regulating their emotions, and their hypothetical responses to their adolescents’ negative emotions, respectively, at consecutive laboratory visits one year apart. Results. Mothers who reported greater attachment-related avoidance and anxiety reported having greater difficulties with emotion regulation one year later. Emotion dysregulation, in turn, predicted more distressed, harsher, and less supportive maternal responses to adolescents’ negative emotions the following year. In addition, greater avoidance directly predicted harsher maternal responses two years later. Conclusions. These findings extend previous research by identifying maternal attachment style as a predictor of responses to adolescent distress and by documenting the underlying role of emotion dysregulation in the link between adult attachment style and parenting.https://doi.org/10.1080/15295192.2014.97276

    Structural characterization of CYP144A1 - a cytochrome P450 enzyme expressed from alternative transcripts in Mycobacterium tuberculosis.

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    Mycobacterium tuberculosis (Mtb) causes the disease tuberculosis (TB). The virulent Mtb H37Rv strain encodes 20 cytochrome P450 (CYP) enzymes, many of which are implicated in Mtb survival and pathogenicity in the human host. Bioinformatics analysis revealed that CYP144A1 is retained exclusively within the Mycobacterium genus, particularly in species causing human and animal disease. Transcriptomic annotation revealed two possible CYP144A1 start codons, leading to expression of (i) a "full-length" 434 amino acid version (CYP144A1-FLV) and (ii) a "truncated" 404 amino acid version (CYP144A1-TRV). Computational analysis predicted that the extended N-terminal region of CYP144A1-FLV is largely unstructured. CYP144A1 FLV and TRV forms were purified in heme-bound states. Mass spectrometry confirmed production of intact, His6-tagged forms of CYP144A1-FLV and -TRV, with EPR demonstrating cysteine thiolate coordination of heme iron in both cases. Hydrodynamic analysis indicated that both CYP144A1 forms are monomeric. CYP144A1-TRV was crystallized and the first structure of a CYP144 family P450 protein determined. CYP144A1-TRV has an open structure primed for substrate binding, with a large active site cavity. Our data provide the first evidence that Mtb produces two different forms of CYP144A1 from alternative transcripts, with CYP144A1-TRV generated from a leaderless transcript lacking a 5'-untranslated region and Shine-Dalgarno ribosome binding site
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