1,102 research outputs found
Recent and Current Educational Research with and in Developing Countries by Researchers from Britain
SUMMARY A survey of British work on education in developing countries lists projects under a number of headings — from ‘qualifications and job selection’, to ‘small countries’, and ‘in service training’. The article ends with a plea for more interdisciplinary work, as well as more cross?national collaboration. RESUMEN Investigación educacional británica reciente con y en los países en desarrollo Este estudio del trabajo británico sobre educación en los países en desarrollo, proporciona una lista de proyectos bajo títulos que van desde ‘calificaciones y selección de trabajo’ a ‘países pequeños’ y ‘en capacitación de servicio’. El artículo termina solicitando mayor trabajo interdisciplinario y mayor colaboración bilateral. SOMMAIRE La récente recherche actuelle sur l'éducation par des chercheurs de Grande?Bretagne avec et dans les pays en voie de développement Un rapport du travail britannique sur l'éducation dans les pays en voie de développement énumère les projets sous différentes rubriques — de ‘qualifications et sélection d'emploi’, à ‘petits pays’, et ‘formation sur le tas’. L'article se termine par des arguments pour un travail plus interdisciplinaire, ainsi qu'une plus grande collaboration transnationale
Multiplicative renormalizability and quark propagator
The renormalized Dyson-Schwinger equation for the quark propagator is
studied, in Landau gauge, in a novel truncation which preserves multiplicative
renormalizability. The renormalization constants are formally eliminated from
the integral equations, and the running coupling explicitly enters the kernels
of the new equations. To construct a truncation which preserves multiplicative
renormalizability, and reproduces the correct leading order perturbative
behavior, non-trivial cancellations involving the full quark-gluon vertex are
assumed in the quark self-energy loop. A model for the running coupling is
introduced, with infrared fixed point in agreement with previous
Dyson-Schwinger studies of the gauge sector, and with correct logarithmic tail.
Dynamical chiral symmetry breaking is investigated, and the generated quark
mass is of the order of the extension of the infrared plateau of the coupling,
and about three times larger than in the Abelian approximation, which violates
multiplicative renormalizability. The generated scale is of the right size for
hadronic phenomenology, without requiring an infrared enhancement of the
running coupling.Comment: 17 pages; minor corrections, comparison to lattice results added;
accepted for publication in Phys. Rev.
Multiplicative renormalizability of gluon and ghost propagators in QCD
We reformulate the coupled set of continuum equations for the renormalized
gluon and ghost propagators in QCD, such that the multiplicative
renormalizability of the solutions is manifest, independently of the specific
form of full vertices and renormalization constants. In the Landau gauge, the
equations are free of renormalization constants, and the renormalization point
dependence enters only through the renormalized coupling and the renormalized
propagator functions. The structure of the equations enables us to devise novel
truncations with solutions that are multiplicatively renormalizable and agree
with the leading order perturbative results. We show that, for infrared power
law behaved propagators, the leading infrared behavior of the gluon equation is
not solely determined by the ghost loop, as concluded in previous studies, but
that the gluon loop, the three-gluon loop, the four-gluon loop, and even
massless quarks also contribute to the infrared analysis. In our new Landau
gauge truncation, the combination of gluon and ghost loop contributions seems
to reject infrared power law solutions, but massless quark loops illustrate how
additional contributions to the gluon vacuum polarization could reinstate these
solutions. Moreover, a schematic study of the three-gluon and four-gluon loops
shows that they too need to be considered in more detail before a definite
conclusion about the existence of infrared power behaved gluon and ghost
propagators can be reached.Comment: 13 pages, 1 figure, submitted to Phys. Rev.
Absence of an association of human polyomavirus and papillomavirus infection with lung cancer in China: a nested case–control study
Abstract Background Studies of human polyomavirus (HPyV) infection and lung cancer are limited and those regarding the association of human papillomavirus (HPV) infection and lung cancer have produced inconsistent results. Methods We conducted a nested case–control study to assess the association between incident lung cancer of various histologies and evidence of prior infection with HPyVs and HPVs. We selected serum from 183 cases and 217 frequency matched controls from the Yunnan Tin Miner’s Cohort study, which was designed to identify biomarkers for early detection of lung cancer. Using multiplex liquid bead microarray (LBMA) antibody assays, we tested for antibodies to the VP1 structural protein and small T antigen (ST-Ag) of Merkel cell, KI, and WU HPyVs. We also tested for antibodies against HPV L1 structural proteins (high-risk types 16, 18, 31, 33, 52, and 58 and low-risk types 6 and 11) and E6 and E7 oncoproteins (high risk types 16 and 18). Measures of antibody reactivity were log transformed and analyzed using logistic regression. Results We found no association between KIV, WUV, and MCV antibody levels and incident lung cancer (P-corrected for multiple comparisons >0.10 for all trend tests). We also found no association with HPV-16, 18, 31, 33, 52, and 58 seropositivity (P-corrected for multiple comparisons >0.05 for all). Conclusions Future studies of infectious etiologies of lung cancer should look beyond HPyVs and HPVs as candidate infectious agents
A study on the revival of shamanism in Horqin, Inner Mongolia
今日の中国は社会主義市場経済を実施し、社会が全面的に発展を遂げている。一方で、こう言った社会の背景のもとに、シャマニズムを含めた民間信仰が復活している。内モンゴルのホルチン地方のシャマニズムの信仰が、在来の世界観を持ちながら復興現象を見せ、人々の日常生活に生き、シャマンが依頼者の請求に応じて自分の役割を果たして人々に好まれている。しかも時代的特徴、つまり変容の姿をも見せている。本研究は今現在におけるホルチン地方のシャマニズムのあり方、つまり復興と変容に着目して、モンゴル人のシャマニズムの信仰体系、おもにシャマンの活動をめぐる諸現象、社会の反応などを分析しながらホルチン地方のシャマニズムの復興と変容の特徴を明らかにすることを目的としている。そのため、ホルチン地方のシャマニズムを復興と変容という二つの内容に分けて述べることにした。今回は復興現象を対象にした。また、論文に用いる資料としては文献資料と筆者が2002年2月、2003年8月、9月に現地調査を行って得た資料を用いた
Non-Neuronal Functions of the M2 Muscarinic Acetylcholine Receptor
Acetylcholine is an important neurotransmitter whose effects are mediated by two classes of receptors. The nicotinic acetylcholine receptors are ion channels, whereas the muscarinic receptors belong to the large family of G protein coupled seven transmembrane helix receptors. Beyond its function in neuronal systems, it has become evident that acetylcholine also plays an important role in non-neuronal cells such as epithelial and immune cells. Furthermore, many cell types in the periphery are capable of synthesizing acetylcholine and express at least some of the receptors. In this review, we summarize the non-neuronal functions of the muscarinic acetylcholine receptors, especially those of the M2 muscarinic receptor in epithelial cells. We will review the mechanisms of signaling by the M2 receptor but also the cellular trafficking and ARF6 mediated endocytosis of this receptor, which play an important role in the regulation of signaling events. In addition, we provide an overview of the M2 receptor in human pathological conditions such as autoimmune diseases and cancer
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Callous-unemotional traits, low cortisol reactivity and physical aggression in children: findings from the Wirral Child Health and Development Study
Callous-unemotional (CU) traits are thought to confer risk for aggression via reduced amygdala responsivity to distress cues in others. Low cortisol reactivity is thought to confer risk for aggression via reduced arousal and this effect may be confined to boys. We tested the hypothesis that the association between childhood CU traits and aggression would be greatest in the absence of the inhibitory effects of cortisol reactivity, and that this effect would be sex dependent. Participants were 283 members of a stratified subsample within an epidemiological longitudinal cohort (WCHADS). Cortisol reactivity to a social stressor was assessed at 5 years. CU traits were reported by mothers at 5 years, and physical aggression by mothers and teachers at age 7. Results showed that CU traits were associated with elevated aggression at 7 years controlling for earlier aggression. There was no main effect of cortisol reactivity on regression. The association between CU traits and aggression was moderated by cortisol reactivity (p = .011) with a strong association between CU traits and aggression in the presence of low reactivity, and a small and non-significant association in the presence of high reactivity. This association was further moderated by child sex (p = .041) with the joint effect of high CU traits and low cortisol reactivity seen only in boys (p = .016). We report first evidence that a combined deficit in inhibitory processes associated with CU traits and low cortisol reactivity increases risk for childhood aggression, in a sex-dependent manner
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Diversity and stability of cultured vaginal lactobacilli in pregnant women from a multi-ethnic urban UK population
Aim: To determine the diversity and stability of cultured vaginal lactobacilli in a multi-ethnic population of pregnant women.
Methods and Results: A single-centre, prospective, cohort study was performed in a tertiary perinatal centre in East London, UK. Self-collected vaginal swabs at 13 and 20 weeks gestation were obtained from women attending for routine antenatal care and cultured for lactobacilli. In women who provided both swabs, 37 of 203 (18%) had no lactobacilli cultured at either time. Only 53 (26%) had the same species at both times. Black women were less likely to have lactobacilli cultured at 13 weeks (P = 0·014), and Black and Asian women were less likely to have lactobacilli cultured at 20 weeks (P = 0·002) compared with those in the White and Other groups.
Conclusions: Significant differences exist between ethnic groups in the carriage and stability of vaginal lactobacilli.
Significance and Impact of the Study: These differences have implications for the design of interventions aimed at normalizing the vaginal microbiota in pregnant women
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