228 research outputs found

    Individual differences and course attendance: Why do students skip class?

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    Individual differences are theorised as being key predictors of students’ lecture attendance. Understanding students’ (lack of) motivation for studying is an essential first step in supporting these individual differences and potentially increasing class/lecture attendance. The current study explored the role of students’ deficits in motivations (ability/effort/task value) for studying and their predictive relationship with course attendance, while controlling for prior competence and academic self-concept. Second-year students (n = 219; Female = 40) undertaking three semester-long courses in English as a foreign language participated in the year-long study. The structural model tested included prior achievement and self-concept (Time-1; 15 weeks prior), the motivational deficits for studying in the course (Time-2; ability, effort and task value), and class attendance across the two semesters of study. Self-concept negatively predicted all motivational deficits (moderate-large effects), and positively predicted attendance. Two of the motivational deficits (ability and effort) also had strongly contrasting effects (positive and negative respectively) on attendance. The implications and practical suggestions for intervention are discussed

    CALIBRATION OF 2-DOF PARALLEL MECHANISM

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    Abstract In order to avoid some drawbacks of traditional Coordinate measuring machine (CMM) based on serial mechanism, we are developing Parallel-CMM based on a parallel mechanism. We have already built the prototype of 3-DOF Parallel CMM and now we are researching about the calibration of our Parallel CMM. When we use a CMM to measure the objects, we need to calibrate the geometrical parameters of the CMM to evaluate the uncertainty of measurement. In this paper, we discuss the details of calibration for 2-DOF parallel mechanism instead of 3-DOF parallel mechanism

    Growth and disease burden in children with hypophosphatasia

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    Hypophosphatasia, an inborn error of metabolism characterized by impaired bone mineralization, can affect growth. This study evaluated relationships between anthropometric parameters (height, weight, and body mass index) and clinical manifestations of hypophosphatasia in children. Design: Data from children (aged < third percentile) and those with normal stature. Methods: Anthropometric parameters were evaluated by age group (< third percentile) and those with normal stature. Results: This analysis included 215 children (54.4% girls). Short stature presented in 16.1% of children aged<2 years and 20.4% of those aged≥2 years at assessment. Among those with available data (n = 62), height was below the target height (mean: −0.66 standard deviations). Substantial worsening of growth (mean delta height z score: −1.45; delta weight z score: −0.68) occurred before 2 years of age, while in those aged≥2 years, anthropometric trajectories were maintained (delta height z score: 0.08; delta weight z score: 0.13). Broad-ranging hypophosphatasia manifestations (beyond dental) were observed in most children. Conclusions: Short stature was not a consistent characteristic of children with hypophosphatasia, but growth impairment was observed in those aged<2 years, indicating that hypophosphatasia might affect growth plate activity during infancy. In addition, a broad range of clinical manifestations occurred in those above and below the third percentile for height, suggesting that height alone may not accurately reflect hypophosphatasia disease burden and that weight is less affected than longitudinal growt

    Identifying SARS-CoV-2 antiviral compounds by screening for small molecule inhibitors of Nsp3 papain-like protease

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    The COVID-19 pandemic has emerged as the biggest life-threatening disease of this century. Whilst vaccination should provide a long-term solution, this is pitted against the constant threat of mutations in the virus rendering the current vaccines less effective. Consequently, small molecule antiviral agents would be extremely useful to complement the vaccination program. The causative agent of COVID-19 is a novel coronavirus, SARS-CoV-2, which encodes at least nine enzymatic activities that all have drug targeting potential. The papain-like protease (PLpro) contained in the nsp3 protein generates viral non-structural proteins from a polyprotein precursor, and cleaves ubiquitin and ISG protein conjugates. Here we describe the expression and purification of PLpro. We developed a protease assay that was used to screen a custom compound library from which we identified dihydrotanshinone I and Ro 08-2750 as compounds that inhibit PLpro in protease and isopeptidase assays and also inhibit viral replication in cell culture-based assays

    The dopamine D1 receptor is expressed and induces CREB phosphorylation and MUC5AC expression in human airway epithelium

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    Background Dopamine receptors comprise two subgroups, Gs protein-coupled “D1-like” receptors (D1, D5) and Gi-coupled “D2-like” receptors (D2, D3, D4). In airways, both dopamine D1 and D2 receptors are expressed on airway smooth muscle and regulate airway smooth muscle force. However, functional expression of the dopamine D1 receptor has never been identified on airway epithelium. Activation of Gs-coupled receptors stimulate adenylyl cyclase leading to cyclic AMP (cAMP) production, which is known to induce mucus overproduction through the cAMP response element binding protein (CREB) in airway epithelial cells. We questioned whether the dopamine D1 receptor is expressed on airway epithelium, and whether it promotes CREB phosphorylation and MUC5AC expression. Methods We evaluated the protein expression of the dopamine D1 receptor on native human airway epithelium and three sources of cultured human airway epithelial cells including primary cultured airway epithelial cells, the bronchial epithelial cell line (16HBE14o-), and the pulmonary mucoepidermoid carcinoma cell line (NCI-H292) using immunohistochemistry and immunoblotting. To characterize the stimulation of cAMP through the dopamine D1 receptor, 16HBE14o- cells and NCI-H292 cells were treated with dopamine or the dopamine D1 receptor agonists (SKF38393 or A68930) before cAMP measurements. The phosphorylation of CREB by A68930 in both 16HBE14o- and NCI-H292 cells was measured by immunoblot. The effect of dopamine or A68930 on the expression of MUC5AC mRNA and protein in NCI-H292 cells was evaluated by real-time PCR and immunofluorescence staining, respectively. Results The dopamine D1 receptor protein was detected in native human airway epithelium and three sources of cultured human airway epithelial cells. Dopamine or the dopamine D1-like receptor agonists stimulated cAMP production in 16HBE14o- cells and NCI-H292 cells, which was reversed by the selective dopamine D1-like receptor antagonists (SCH23390 or SCH39166). A68930 significantly increased phosphorylation of CREB in both 16HBE14o- and NCI-H292 cells, which was attenuated by the inhibitors of PKA (H89) and MEK (U0126). Expression of MUC5AC mRNA and protein were also increased by either dopamine or A68930 in NCI-H292 cells. Conclusions These results suggest that the activation of the dopamine D1 receptor on human airway epithelium could induce mucus overproduction, which could worsen airway obstructive symptoms

    Methamphetamine induces endoplasmic reticulum stress related gene CHOP/Gadd153/ddit3 in dopaminergic cells

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    We examined the toxicity of methamphetamine and dopamine in CATH.a cells, which were derived from mouse dopamine-producing neural cells in the central nervous system. Use of the quantitative real-time polymerase chain reaction revealed that transcripts of the endoplasmic reticulum stress related gene (CHOP/Gadd153/ddit3) were considerably induced at 24–48 h after methamphetamine administration (but only under apoptotic conditions), whereas dopamine slightly induced CHOP/Gadd153/ddit3 transcripts at an early stage. We also found that dopamine and methamphetamine weakly induced transcripts for the glucose-regulated protein 78 gene (Grp78/Bip) at the early stage. Analysis by immunofluorescence microscopy demonstrated an increase of CHOP/Gadd153/ddit3 and Grp78/Bip proteins at 24 h after methamphetamine administration. Treatment of CATH.a cells with methamphetamine caused a re-distribution of dopamine inside the cells, which mimicked the presynaptic activity of neurons with cell bodies located in the ventral tegmental area or the substantia nigra. Thus, we have demonstrated the existence of endoplasmic reticulum stress in a model of presynaptic dopaminergic neurons for the first time. Together with the recent evidence suggesting the importance of presynaptic toxicity, our findings provide new insights into the mechanisms of dopamine toxicity, which might represent one of the most important mechanisms of methamphetamine toxicity and addiction

    Impact of muscular symptoms and/or pain on disease characteristics, disability, and quality of life in adult patients with hypophosphatasia: A cross-sectional analysis from the Global HPP Registry

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    IntroductionHypophosphatasia (HPP) manifests in adults as fractures/pseudofractures, pain, muscle weakness, and other functional impairments. Better phenotypic disease characterization is needed to help recognize disability and treat patients with HPP.MethodsBaseline/pretreatment demographic, clinical characteristic, and patient-reported disability/health-related quality-of-life (HRQoL) data from adults (≥18 y) in the Global HPP Registry (NCT02306720) were stratified by presence of overt skeletal manifestations (skeletal group) versus muscular/pain manifestations without skeletal manifestations (muscular/pain group) and summarized descriptively. Disability was measured using the Health Assessment Questionnaire–Disability Index (HAQ-DI), and HRQoL using the 36-item Short Form Health Survey (SF-36v2).ResultsOf 468 adults, 300 were classified into the skeletal group and 73 into the muscular/pain group. The skeletal group had a higher median age at baseline (50.1 vs 44.4 y; P=0.047) but a lower median age at first HPP manifestation (12.3 vs 22.1 y; P=0.0473), with more signs and symptoms (median, 4 vs 3; P&lt;0.0001) and involved body systems (median, 3 vs 2; P&lt;0.0001) than the muscular/pain group. More patients in the skeletal group required any use of mobility aids (22.6% vs 3.5%, respectively; P=0.001). Six-Minute Walk test distances walked were similar between groups. SF-36v2 and HAQ-DI scores were similar between groups for physical component summary (n=238; mean [SD]: 40.2 [11.0] vs 43.6 [11.2]; P=0.056), mental component summary (n=238; mean [SD]: 43.6 [11.3] vs 43.8 [11.8]; P=0.902), and HAQ-DI (n=239; median [minimum, maximum]: 0.4 [0.0, 2.7] vs 0.3 [0.0, 2.1]; P=0.22).ConclusionAdults with HPP experience similar QoL impairment regardless of skeletal involvement.Registrationhttps://clinicaltrials.gov/ct2/show/NCT02306720 and https://www.encepp.eu/encepp/viewResource.htm?id=47907, identifier NCT02306720; EUPAS13514

    E2F1-Mediated Upregulation of p19INK4d Determines Its Periodic Expression during Cell Cycle and Regulates Cellular Proliferation

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    BACKGROUND: A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. CONCLUSIONS/SIGNIFICANCE: The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an additional mechanism to limit E2F activity

    Safety of growth hormone replacement in survivors of cancer and intracranial and pituitary tumours: a consensus statement

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    Growth hormone (GH) has been used for over 35 years, and its safety and efficacy has been studied extensively. Experimental studies showing the permissive role of GH/insulin-like growth factor 1 (IGF-I) in carcinogenesis have raised concerns regarding the safety of GH replacement in children and adults who have received treatment for cancer and those with intracranial and pituitary tumours. A consensus statement was produced to guide decision-making on GH replacement in children and adult survivors of cancer, in those treated for intracranial and pituitary tumours and in patients with increased cancer risk. With the support of the European Society of Endocrinology, the Growth Hormone Research Society convened a Workshop, where 55 international key opinion leaders representing 10 professional societies were invited to participate. This consensus statement utilized: (1) a critical review paper produced before the Workshop, (2) five plenary talks, (3) evidence-based comments from four breakout groups, and (4) discussions during report-back sessions. Current evidence reviewed from the proceedings from the Workshop does not support an association between GH replacement and primary tumour or cancer recurrence. The effect of GH replacement on secondary neoplasia risk is minor compared to host- and tumour treatment-related factors. There is no evidence for an association between GH replacement and increased mortality from cancer amongst GH-deficient childhood cancer survivors. Patients with pituitary tumour or craniopharyngioma remnants receiving GH replacement do not need to be treated or monitored differently than those not receiving GH. GH replacement might be considered in GH-deficient adult cancer survivors in remission after careful individual risk/benefit analysis. In children with cancer predisposition syndromes, GH treatment is generally contraindicated but may be considered cautiously in select patients
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