170 research outputs found
Does the level of motivation of physical education teachers matter in terms of job satisfaction and emotional exhaustion? A person-centered examination based on self-determination theory
Grounded in self-determination theory (SDT), prior research has demonstrated that physical education (PE) teachers may have different reasons to engage in teaching. Although some person-centered studies have identified varied motivational profiles in PE teachers, none of these studies have included the three forms of motivation (i.e., autonomous motivation, controlled motivation, and amotivation). This study aims to identify teachersâ motivational profiles, using the three forms of motivation. Moreover, differences between the obtained profiles in terms of job satisfaction and emotional exhaustion were examined. A sample of 107 primary school PE teachers participated. Four distinct motivational profiles were identified: ârelatively amotivated,â âsomewhat motivated,â âautonomous-controlled motivated,â and ârelatively autonomously motivated.â Results showed that the predominantly autonomously motivated PE teachers reported the most adaptive pattern of outcomes. Although PE teachers from the ârelatively autonomously motivatedâ group did not differ in terms of job satisfaction when compared to those in the âautonomous-controlled motivatedâ group, the former displayed lower values of emotional exhaustion. These findings support SDT in that more motivation is not necessarily better if this additional motivation comes from controlled reasons. These results could raise awareness among school stakeholders about the importance of increasing PE teachersâ autonomous motivation
Influence of handover mechanisms and transmission delay difference on SFN gain
Single Frequency Networks (SFNs) are often deployed for their optimal frequency reuse and the more homogeneous distribution of the field strength in the covered area. Different methodologies have already been proposed to calculate the so-called SFN gain over Multi Frequency Networks (MFNs), but so far, the influence of (MFN) handover mechanisms on the gain values has not yet been investigated. Also, it can be expected that in SFNs, the gain values will depend on the transmission delay difference of the signals from the different transmitters in the SFN. This paper will first assess the influence of a handover mechanism on previously obtained SFN gain values. Secondly, it will be investigated if the transmission delay difference is a good predictor for the SFN gain. This paper further clarifies the SFN concept from a network planner's point of view and aids in understanding what a network planner should take into account when deploying an SFN
Sex hormone-binding globulin regulation of androgen bioactivity in vivo : validation of the free hormone hypothesis
Sex hormone-binding globulin (SHBG) is the high-affinity binding protein for androgens and estrogens. According to the free hormone hypothesis, SHBG modulates the bioactivity of sex steroids by limiting their diffusion into target tissues. Still, the in vivo physiological role of circulating SHBG remains unclear, especially since mice and rats lack circulating SHBG post-natally. To test the free hormone hypothesis in vivo, we examined total and free sex steroid concentrations and bioactivity on target organs in mice expressing a human SHBG transgene. SHBG increased total androgen and estrogen concentrations via hypothalamic-pituitary feedback regulation and prolonged ligand half-life. Despite markedly raised total sex steroid concentrations, free testosterone was unaffected while sex steroid bioactivity on male and female reproductive organs was attenuated. This occurred via a liganddependent, genotype-independent mechanism according to in vitro seminal vesicle organ cultures. These results provide compelling support for the determination of free or bioavailable sex steroid concentrations in medicine, and clarify important comparative differences between translational mouse models and human endocrinology
An integrated analysis of miRNA and gene copy numbers in xenografts of Ewing's sarcoma
<p>Abstract</p> <p>Background</p> <p>Xenografts have been shown to provide a suitable source of tumor tissue for molecular analysis in the absence of primary tumor material. We utilized ES xenograft series for integrated microarray analyses to identify novel biomarkers.</p> <p>Method</p> <p>Microarray technology (array comparative genomic hybridization (aCGH) and micro RNA arrays) was used to screen and identify copy number changes and differentially expressed miRNAs of 34 and 14 passages, respectively. Incubated cells used for xenografting (Passage 0) were considered to represent the primary tumor. Four important differentially expressed miRNAs (miR-31, miR-31*, miR-145, miR-106) were selected for further validation by real time polymerase chain reaction (RT-PCR). Integrated analysis of aCGH and miRNA data was performed on 14 xenograft passages by bioinformatic methods.</p> <p>Results</p> <p>The most frequent losses and gains of DNA copy number were detected at 9p21.3, 16q and at 8, 15, 17q21.32-qter, 1q21.1-qter, respectively. The presence of these alterations was consistent in all tumor passages. aCGH profiles of xenograft passages of each series resembled their corresponding primary tumors (passage 0). MiR-21, miR-31, miR-31*, miR-106b, miR-145, miR-150*, miR-371-5p, miR-557 and miR-598 showed recurrently altered expression. These miRNAS were predicted to regulate many ES-associated genes, such as genes of the IGF1 pathway, <it>EWSR1, FLI1 </it>and their fusion gene (<it>EWS-FLI1</it>). Twenty differentially expressed miRNAs were pinpointed in regions carrying altered copy numbers.</p> <p>Conclusion</p> <p>In the present study, ES xenografts were successfully applied for integrated microarray analyses. Our findings showed expression changes of miRNAs that were predicted to regulate many ES associated genes, such as IGF1 pathway genes, <it>FLI1, EWSR1</it>, and the <it>EWS-FLI1 </it>fusion genes.</p
Glial ÎČ-Oxidation regulates drosophila energy metabolism
The brain's impotence to utilize long-chain fatty acids as fuel, one of the dogmas in neuroscience, is surprising, since the nervous system is the tissue most energy consuming and most vulnerable to a lack of energy. Challenging this view, we here show in vivo that loss of the Drosophila carnitine palmitoyltransferase 2 (CPT2), an enzyme required for mitochondrial ÎČ-oxidation of long-chain fatty acids as substrates for energy production, results in the accumulation of triacylglyceride-filled lipid droplets in adult Drosophila brain but not in obesity. CPT2 rescue in glial cells alone is sufficient to restore triacylglyceride homeostasis, and we suggest that this is mediated by the release of ketone bodies from the rescued glial cells. These results demonstrate that the adult brain is able to catabolize fatty acids for cellular energy production.This work was partially supported by the Flanders Fund for Scientific Research (FWO G 0.666.10N), NEUROBRAINNET IAP 7/16, Flemish Government Methusalem Grant, Spanish Ministry of Science (SAF2010-14906) and Innovation Ingenio-Consolider (CSD2010-00045) and Spanish Ministry of Economy and Competitiveness (SAF2013-45392).Peer Reviewe
Glial ÎČ-Oxidation regulates drosophila energy metabolism
The brain's impotence to utilize long-chain fatty acids as fuel, one of the dogmas in neuroscience, is surprising, since the nervous system is the tissue most energy consuming and most vulnerable to a lack of energy. Challenging this view, we here show in vivo that loss of the Drosophila carnitine palmitoyltransferase 2 (CPT2), an enzyme required for mitochondrial ÎČ-oxidation of long-chain fatty acids as substrates for energy production, results in the accumulation of triacylglyceride-filled lipid droplets in adult Drosophila brain but not in obesity. CPT2 rescue in glial cells alone is sufficient to restore triacylglyceride homeostasis, and we suggest that this is mediated by the release of ketone bodies from the rescued glial cells. These results demonstrate that the adult brain is able to catabolize fatty acids for cellular energy production.This work was partially supported by the Flanders Fund for Scientific Research (FWO G 0.666.10N), NEUROBRAINNET IAP 7/16, Flemish Government Methusalem Grant, Spanish Ministry of Science (SAF2010-14906) and Innovation Ingenio-Consolider (CSD2010-00045) and Spanish Ministry of Economy and Competitiveness (SAF2013-45392).Peer Reviewe
Comparison of procedures for RNA-extraction from peripheral blood mononuclear cells
RNA quality and quantity are important factors for ensuring the accuracy of gene expression analysis and other RNA-based downstream applications. Thus far, only a limited number of methodological studies have compared sample storage and RNA extraction procedures for human cells. We compared three commercially available RNA extraction kits, i.e., (NucliSENS) easyMAG, RNeasy (Mini Kit) and RiboPure (RNA Purification Kitâblood). In addition, additional conditions, such as storage medium and storage temperature of human peripheral blood mononuclear cells were evaluated, i.e., 4 °C for RNAlater or -80 °C for QIAzol and for the respective cognate lysis buffers; easyMAG, RNeasy or RiboPure. RNA was extracted from aliquots that had been stored for one day (Run 1) or 83 days (Run 2). After DNase treatment, quantity and quality of RNA were assessed by means of a NanoDrop spectrophotometer, 2100 Bioanalyzer and RT-qPCR for the ACTB reference gene. We observed that high-quality RNA can be obtained using RNeasy and RiboPure, regardless of the storage medium, whereas samples stored in RNAlater resulted in the least amount of RNA extracted. In addition, RiboPure combined with storage of samples in its cognate lysis buffer yielded twice as much RNA as all other procedures. These results were supported by RT-qPCR and by the reproducibility observed for two independent extraction runs
APHRODITE criteria:addressing male patients with hypogonadism and/or infertility owing to altered idiopathic testicular function
Research question: Can a novel classification system of the infertile male - 'APHRODITE' (Addressing male Patients with Hypogonadism and/or infeRtility Owing to altereD, Idiopathic TEsticular function) - stratify different subgroups of male infertility to help scientists to design clinical trials on the hormonal treatment of male infertility, and clinicians to counsel and treat the endocrinological imbalances in men and, ultimately, increase the chances of natural and assisted conception?Design: A collaboration between andrologists, reproductive urologists and gynaecologists, with specialization in reproductive medicine and expertise in male infertility, led to the development of the APHRODITE criteria through an iterative consensus process based on clinical patient descriptions and the results of routine laboratory tests, including semen analysis and hormonal testing.Results: Five patient groups were delineated according to the APHRODITE criteria; (1) Hypogonadotrophic hypogonadism (acquired and congenital); (2) Idiopathic male infertility with lowered semen analysis parameters, normal serum FSH and normal serum total testosterone concentrations; (3) A hypogonadal state with lowered semen analysis parameters, normal FSH and reduced total testosterone concentrations; (4) Lowered semen analysis parameters, elevated FSH concentrations and reduced or normal total testosterone concentrations; and (5) Unexplained male infertility in the context of unexplained couple infertility.Conclusion: The APHRODITE criteria offer a novel and standardized patient stratification system for male infertility independent of aetiology and/or altered spermatogenesis, facilitating communication among clinicians, researchers and patients to improve reproductive outcomes following hormonal therapy. APHRODITE is proposed as a basis for future trials of the hormonal treatment of male infertility.</p
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