1,110 research outputs found

    Are your students safe to learn? The role of lecturer’s authentic leadership in the creation of psychologically safe environments and their impact on academic performance:The role of teacher's authentic leadership on the creation of psychologically safe environments and their impact on academic performance

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    As the role of students and lecturers in higher education changes, several questions emerge about the role of each of them on students? academic performance. This includes questions regarding the impact of the relationships between students, lecturer?s characteristics and the social environment on students? performance. To address these questions, this article reports a study of the impact of lecturer authentic leadership, psychological safety and network density on academic performance. It explores the relationship between network density, psychological safety and lecturer authentic leadership. A questionnaire was distributed to undergraduate students. A positive impact of lecturer authentic leadership and psychological safety on academic performance was found. Students from high-density groups tended to show better academic performance, higher psychological safety and tended to see their lecturers as being more authentic. A reflection on the role of the lecturer in higher education settings is presented. It also presents some recommendations on how student academic performance can be improved by the adoption of specific behaviours by their lecturer

    Isolation and fine mapping of Rps6: An intermediate host resistance gene in barley to wheat stripe rust

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    A plant may be considered a nonhost of a pathogen if all known genotypes of a plant species are resistant to all known isolates of a pathogen species. However, if a small number of genotypes are susceptible to some known isolates of a pathogen species this plant maybe considered an intermediate host. Barley (Hordeum vulgare) is an intermediate host for Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust. We wanted to understand the genetic architecture underlying resistance to Pst and to determine whether any overlap exists with resistance to the host pathogen, Puccinia striiformis f. sp. hordei (Psh). We mapped Pst resistance to chromosome 7H and show that host and intermediate host resistance is genetically uncoupled. Therefore, we designate this resistance locus Rps6. We used phenotypic and genotypic selection on F2:3 families to isolate Rps6 and fine mapped the locus to a 0.1 cM region. Anchoring of the Rps6 locus to the barley physical map placed the region on two adjacent fingerprinted contigs. Efforts are now underway to sequence the minimal tiling path and to delimit the physical region harbouring Rps6. This will facilitate additional marker development and permit identification of candidate genes in the region

    Phase II trial of weekly 24-hour infusion of gemcitabine in patients with advanced gallbladder and biliary tract carcinoma

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    BACKGROUND: Patients with advanced gallbladder and biliary tract carcinoma face a dismal prognosis, as no effective palliative chemotherapy exists. The antitumor effect of gemcitabine is schedule-dependent rather than dose-dependent. We evaluated the activity of a prolonged infusion of gemcitabine in advanced gallbladder and biliary tract carcinomas. METHODS: Nineteen consecutive eligible patients were enrolled. All patients were required to have histologically confirmed diagnosis and measurable disease. Gemcitabine was infused over 24 hours at a dose of 100 mg/m(2 )on days 1, 8, and 15. Treatment was repeated every 28 days until progression of disease or limiting toxicity. Tumor response was evaluated every second course by computed tomography (CT) scans. RESULTS: Eighteen patients were evaluable for response. A total of 89 cycles of therapy were administered. One partial response was observed (6%; 95% confidence interval (CI): 0–27%) and ten additional patients had stable disease for at least two months (disease control rate 61%; 95% CI: 36–83%). The therapy was well tolerated, with moderate myelosuppression as the main toxicity. The median time to tumor progression and median overall survival was 3.6 months (95% CI 2.6–4.6 months) and 7.5 months (95% CI 6.5–8.5 months), respectively. CONCLUSION: Weekly 24-hour gemcitabine at a dose of 100 mg/m(2 )is well tolerated. There was a relatively high rate of disease control for a median duration of 5.3 months (range 2.8–18.8 months). However, the objective response rate of this regimen in gallbladder and biliary tract carcinomas was limited

    Effects of common haplotypes of the ileal sodium dependent bile acid transporter gene on the development of sporadic and familial colorectal cancer: A case control study

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    <p>Abstract</p> <p>Background</p> <p>The genetics of sporadic and non-syndromic familial colorectal cancer (CRC) is not well defined. However, genetic factors that promote the development of precursor lesions, i.e. adenomas, might also predispose to CRC. Recently, an association of colorectal adenoma with two variants (c.507C>T;p.L169L and c.511G>T;p.A171S) of the ileal sodium dependent bile acid transporter gene (<it>SLC10A2</it>) has been reported. Here, we reconstructed haplotypes of the <it>SLC10A2 </it>gene locus and tested for association with non-syndromic familial and sporadic CRC compared to 'hyper-normal' controls who displayed no colorectal polyps on screening colonoscopy.</p> <p>Methods</p> <p>We included 150 patients with sporadic CRC, 93 patients with familial CRC but exclusion of familial adenomatous polyposis and Lynch's syndrome, and 204 'hyper-normal' controls. Haplotype-tagging <it>SLC10A2 </it>gene variants were identified in the Hapmap database and genotyped using PCR-based 5' exonuclease assays with fluorescent dye-labelled probes. Haplotypes were reconstructed using the PHASE algorithm. Association testing was performed with both SNPs and reconstructed haplotypes.</p> <p>Results</p> <p>Minor allele frequencies of all <it>SLC10A2 </it>polymorphisms are within previously reported ranges, and no deviations from Hardy-Weinberg equilibrium are observed. However, we found no association with any of the <it>SLC10A2 </it>haplotypes with sporadic or familial CRC in our samples (all P values > 0.05).</p> <p>Conclusion</p> <p>Common variants of the <it>SLC10A2 </it>gene are not associated with sporadic or familial CRC. Hence, albeit this gene might be associated with early stages of colorectal neoplasia, it appears not to represent a major risk factor for progression to CRC.</p

    Prefrontal Cortex Glutamate Correlates with Mental Perspective-Taking

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    Background: Dysfunctions in theory of mind and empathic abilities have been suggested as core symptoms in major psychiatric disorders including schizophrenia and autism. Since self monitoring, perspective taking and empathy have been linked to prefrontal (PFC) and anterior cingulate cortex (ACC) function, neurotransmitter variations in these areas may account for normal and pathological variations of these functions. Converging evidence indicates an essential role of glutamatergic neurotransmission in psychiatric diseases with pronounced deficits in empathy. However, the role of the glutamate system for different dimensions of empathy has not been investigated so far. Methodology/Principal Findings: Absolute concentrations of cerebral glutamate in the ACC, left dorsolateral PFC and left hippocampus were determined by 3-tesla proton magnetic resonance spectroscopy (1H-MRS) in 17 healthy individuals. Three dimensions of empathy were estimated by a self-rating questionnaire, the Interpersonal Reactivity Index (IRI). Linear regression analysis showed that dorsolateral PFC glutamate concentration was predicted by IRI factor ‘‘perspective taking’’ (T = 22.710, p = 0.018; adjusted alpha-level of 0.017, Bonferroni) but not by ‘‘empathic concern’ ’ or ‘‘personal distress’’. No significant relationship between IRI subscores and the glutamate levels in the ACC or left hippocampus was detected. Conclusions/Significance: This is the first study to investigate the role of the glutamate system for dimensions of theory of mind and empathy. Results are in line with recent concepts that executive top-down control of behavior is mediated b

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Spatial Frequency-Based Analysis of Mean Red Blood Cell Speed in Single Microvessels: Investigation of Microvascular Perfusion in Rat Cerebral Cortex

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    BACKGROUND: Our previous study has shown that prenatal exposure to X-ray irradiation causes cerebral hypo-perfusion during the postnatal development of central nervous system (CNS). However, the source of the hypo-perfusion and its impact on the CNS development remains unclear. The present study developed an automatic analysis method to determine the mean red blood cell (RBC) speed through single microvessels imaged with two-photon microscopy in the cerebral cortex of rats prenatally exposed to X-ray irradiation (1.5 Gy). METHODOLOGY/PRINCIPAL FINDINGS: We obtained a mean RBC speed (0.9±0.6 mm/sec) that ranged from 0.2 to 4.4 mm/sec from 121 vessels in the radiation-exposed rats, which was about 40% lower than that of normal rats that were not exposed. These results were then compared with the conventional method for monitoring microvascular perfusion using the arteriovenous transit time (AVTT) determined by tracking fluorescent markers. A significant increase in the AVTT was observed in the exposed rats (1.9±0.6 sec) as compared to the age-matched non-exposed rats (1.2±0.3 sec). The results indicate that parenchyma capillary blood velocity in the exposed rats was approximately 37% lower than in non-exposed rats. CONCLUSIONS/SIGNIFICANCE: The algorithm presented is simple and robust relative to monitoring individual RBC speeds, which is superior in terms of noise tolerance and computation time. The demonstrative results show that the method developed in this study for determining the mean RBC speed in the spatial frequency domain was consistent with the conventional transit time method

    Effects of food on physical and sleep complaints in children with ADHD: a randomised controlled pilot study

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    Attention deficit/hyperactivity disorder (ADHD), a common behavioural disorder in children, may be associated with comorbid physical and sleep complaints. Dietary intervention studies have shown convincing evidence of efficacy in reducing ADHD symptoms in children. In this pilot study, we investigated the effects of an elimination diet on physical and sleep complaints in children with ADHD. A group of 27 children (3.8–8.5 years old), who all met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for ADHD, were assigned randomly to either a diet group (15/27) or a control group (12/27). The diet group followed a 5-week elimination diet; the control group adhered to their normal diet. Parents of both groups had to keep an extended diary and had to monitor the behaviour and the physical and sleep complaints of their child conscientiously. The primary endpoint was the clinical response, i.e. a decrease of physical and sleep complaints, at the end of the trial, based on parent ratings on a Physical Complaints Questionnaire. The number of physical and sleep complaints was significantly decreased in the diet group compared to the control group (p < 0.001), with a reduction in the diet group of 77% (p < 0.001, effect size = 2.0) and in the control group of 17% (p = 0.08, effect size = 0.2). Specific complaints that were significantly reduced were in three domains: headaches or bellyaches, unusual thirst or unusual perspiration, and sleep complaints. The reduction of complaints seemed to occur independently of the behavioural changes (p = 0.1). However, the power of this comparison was low. A positive correlation existed between the reduction of physical and behavioural symptoms (p < 0.01). The reduction did not differ between children with or without an atopic constitution (p = 0.7). An elimination diet may be an effective instrument to reduce physical complaints in children with ADHD, but more research is needed to determine the effects of food on (functional) somatic symptoms in children with and without ADHD. This trial was registered as an International Standard Randomised Controlled Trial, ISRCTN47247160

    Prenatal Stress Exposure Related to Maternal Bereavement and Risk of Childhood Overweight

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    BACKGROUND: It has been suggested that prenatal stress contributes to the risk of obesity later in life. In a population-based cohort study, we examined whether prenatal stress related to maternal bereavement during pregnancy was associated with the risk of overweight in offspring during school age. METHODOLOGY/PRINCIPAL FINDINGS: We followed 65,212 children born in Denmark from 1970-1989 who underwent health examinations from 7 to 13 years of age in public or private schools in Copenhagen. We identified 459 children as exposed to prenatal stress, defined by being born to mothers who were bereaved by death of a close family member from one year before pregnancy until birth of the child. We compared the prevalence of overweight between the exposed and the unexposed. Body mass index (BMI) values and prevalence of overweight were higher in the exposed children, but not significantly so until from 10 years of age and onwards, as compared with the unexposed children. For example, the adjusted odds ratio (OR) for overweight was 1.68 (95% confidence interval [CI] 1.08-2.61) at 12 years of age and 1.63 (95% CI 1.00-2.61) at 13 years of age. The highest ORs were observed when the death occurred in the period from 6 to 0 month before pregnancy (OR 3.31, 95% CI 1.71-6.42 at age 12, and OR 2.31, 95% CI 1.08-4.97 at age 13). CONCLUSIONS/SIGNIFICANCE: Our results suggest that severe pre-pregnancy stress is associated with an increased risk of overweight in the offspring in later childhood

    ARHGEF7 (BETA-PIX) Acts as Guanine Nucleotide Exchange Factor for Leucine-Rich Repeat Kinase 2

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    Background: Mutations within the leucine-rich repeat kinase 2 (LRRK2) gene are a common cause of familial and sporadic Parkinson’s disease. The multidomain protein LRRK2 exhibits overall low GTPase and kinase activity in vitro. Methodology/Principal Findings: Here, we show that the rho guanine nucleotide exchange factor ARHGEF7 and the small GTPase CDC42 are interacting with LRRK2 in vitro and in vivo. GTPase activity of full-length LRRK2 increases in the presence of recombinant ARHGEF7. Interestingly, LRRK2 phosphorylates ARHGEF7 in vitro at previously unknown phosphorylation sites. We provide evidence that ARHGEF7 might act as a guanine nucleotide exchange factor for LRRK2 and that R1441C mutant LRRK2 with reduced GTP hydrolysis activity also shows reduced binding to ARHGEF7. Conclusions/Significance: Downstream effects of phosphorylation of ARHGEF7 through LRRK2 could be (i) a feedback control mechanism for LRRK2 activity as well as (ii) an impact of LRRK2 on actin cytoskeleton regulation. A newly identified familial mutation N1437S, localized within the GTPase domain of LRRK2, further underlines the importance of the GTPas
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