295 research outputs found

    Effect of Background, Attitudinal and Social Network Variables on PhD Students’ Academic Performance. A Multimethod Approach

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    The aim of this paper is to predict the academic performance of PhD students understood as publications and presentations at conferences. MATERIALS AND METHODS: We use a multimethod approach, a quantitative web survey of PhD students and their supervisors and in-depth interviews. We surveyed all PhD students at the University of Girona (Spain) in their 4th and 5th year, who held either a PhD grant or a teaching position at the university. RESULTS: The explanatory variables of PhD performance are of three types: characteristics of the PhD students’ research groups understood as social networks, background variables and attitudinal characteristics. The quantitative analyses show the importance of some background and attitudinal variables like supervisor performance, having a grant, or motivation. The qualitative results show networking to be also important. Policy implications are drawn at country and university level. DISCUSSION: Policy implications are drawn at country and university level

    SNP-based pathway enrichment analysis for genome-wide association studies

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    <p>Abstract</p> <p>Background</p> <p>Recently we have witnessed a surge of interest in using genome-wide association studies (GWAS) to discover the genetic basis of complex diseases. Many genetic variations, mostly in the form of single nucleotide polymorphisms (SNPs), have been identified in a wide spectrum of diseases, including diabetes, cancer, and psychiatric diseases. A common theme arising from these studies is that the genetic variations discovered by GWAS can only explain a small fraction of the genetic risks associated with the complex diseases. New strategies and statistical approaches are needed to address this lack of explanation. One such approach is the pathway analysis, which considers the genetic variations underlying a biological pathway, rather than separately as in the traditional GWAS studies. A critical challenge in the pathway analysis is how to combine evidences of association over multiple SNPs within a gene and multiple genes within a pathway. Most current methods choose the most significant SNP from each gene as a representative, ignoring the joint action of multiple SNPs within a gene. This approach leads to preferential identification of genes with a greater number of SNPs.</p> <p>Results</p> <p>We describe a SNP-based pathway enrichment method for GWAS studies. The method consists of the following two main steps: 1) for a given pathway, using an adaptive truncated product statistic to identify all representative (potentially more than one) SNPs of each gene, calculating the average number of representative SNPs for the genes, then re-selecting the representative SNPs of genes in the pathway based on this number; and 2) ranking all selected SNPs by the significance of their statistical association with a trait of interest, and testing if the set of SNPs from a particular pathway is significantly enriched with high ranks using a weighted Kolmogorov-Smirnov test. We applied our method to two large genetically distinct GWAS data sets of schizophrenia, one from European-American (EA) and the other from African-American (AA). In the EA data set, we found 22 pathways with nominal P-value less than or equal to 0.001 and corresponding false discovery rate (FDR) less than 5%. In the AA data set, we found 11 pathways by controlling the same nominal P-value and FDR threshold. Interestingly, 8 of these pathways overlap with those found in the EA sample. We have implemented our method in a JAVA software package, called <it>SNP Set Enrichment Analysis </it>(SSEA), which contains a user-friendly interface and is freely available at <url>http://cbcl.ics.uci.edu/SSEA.</url></p> <p>Conclusions</p> <p>The SNP-based pathway enrichment method described here offers a new alternative approach for analysing GWAS data. By applying it to schizophrenia GWAS studies, we show that our method is able to identify statistically significant pathways, and importantly, pathways that can be replicated in large genetically distinct samples.</p

    Prevalencia de perdida prematura de primeros molares permanentes, en escolares de 8 anos de edad pertenecientes a diferentes tipos de colegios de la ciudad de Talca

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    57 p.Se efectuó un estudio epidemiológico para determinar la prevalencia de pérdida prematura de los Primeros Molares Permanentes, en la población escolar de 8 arlos de edad, de la Comuna de Talca. Se determinó además la relación entre el tipo de colegio al cual asistían los niños y la perdida prematura de los molares. La prevalencia total de pérdida prematura de PMP Para los escolares de 8 años de edad de la ciudad de Talca es de 15, 67 %, El 84,33 % de los escolares presentaba sus cuatro molares sin patologías evidentes, No se encontró una relación estadísticamente significativa, entre la perdida prematura de PMP y el tipo de colegio al cual asistían los niños, Se encontró un mayor porcentaje de pérdida prematura en el sexo femenino que es de 16,13 %, comparado con el 15,17 % encontrado en el sexo masculino. Sólo el 1 % de los PMP ya había sido extraído, entre los 6 y 7 años de edad; 0,67 % correspondi6 a la pieza 4.6 y 0,33 % a la pieza 3.6. La pieza mas afectada por caries es la 4.6 con un 5,33 %; seguida de la pieza 1.6 y 2.6 con igual porcentaje 0,33 % y finalmente la 3.6 con un 2,67 %.La mayor parte de la población examinada tenia una frecuencia de cepillado de 2 veces al día, que correspondió al 40 %. Sólo el 2 % de los niños confesó no lavarse los dientes en ningún momento del día. El 72,67 % de los escolares examinados habían recibido atención dental, por lo menos una vez, en los últimos 12 meses; el 27,33 % de los escolares nunca había recibido atención dental. El 96,67 % de los niños utilizaba pasta dental al momento de cepillar sus diente

    On the tracks of Nitrogen deposition effects on temperate forests at their southern European range - an observational study from Italy

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    We studied forest monitoring data collected at permanent plots in Italy over the period 2000\u20132009 to identify the possible impact of nitrogen (N) deposition on soil chemistry, tree nutrition and growth. Average N throughfall (N-NO3+N-NH4) ranged between 4 and 29 kg ha 1 yr 1, with Critical Loads (CLs) for nutrient N exceeded at several sites. Evidence is consistent in pointing out effects of N deposition on soil and tree nutrition: topsoil exchangeable base cations (BCE) and pH decreased with increasing N deposition, and foliar nutrient N ratios (especially N : P and N : K) increased. Comparison between bulk openfield and throughfall data suggested possible canopy uptake of N, levelling out for bulk deposition &gt;4\u20136 kg ha 1 yr 1. Partial Least Square (PLS) regression revealed that - although stand and meteorological variables explained the largest portion of variance in relative basal area increment (BAIrel 2000\u20132009) - N-related predictors (topsoil BCE, C : N, pH; foliar N-ratios; N deposition) nearly always improved the BAIrel model in terms of variance explained (from 78.2 to 93.5%) and error (from 2.98 to 1.50%). N deposition was the strongest predictor even when stand, management and atmosphere-related variables (meteorology and tropospheric ozone) were accounted for. The maximal annual response of BAIrel was estimated at 0.074\u20130.085% for every additional kgN. This corresponds to an annual maximal relative increase of 0.13\u20130.14% of carbon sequestered in the above-ground woody biomass for every additional kgN, i.e. a median value of 159 kgC per kgN ha 1 yr 1 (range: 50\u2013504 kgC per kgN, depending on the site). Positive growth response occurred also at sites where signals of possible, perhaps recent N saturation were detected. This may suggest a time lag for detrimental N effects, but also that, under continuous high N input, the reported positive growth response may be not sustainable in the long-term

    A kapwa-infused paradigm in teaching Catholic theology/catechesis in a multireligious classroom in the Philippines

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    The increasing religious diversity in educational space has raised a legitimate question on how Catholic theology/ catechesis must be taught in Philippine Catholic universities given the institutional mandate to educate students “into the faith of the Church through teaching of Christian doctrine in an organic and systematic way” (Wuerl, 2013, 1). On this note, the paper makes reference to “centered plural- ism” (CP), a positional posture espoused by Georgetown University in dealing with this predicament. In an attempt to (re) appropriate CP into local context, there is a need to explore the Filipino conception of self/others as enveloped within the indigenous concept of kapwa. Hereon, the paper finds that CP is not just feasibly suitable in local context but with kapwa's more inclusive description of the relationship of self and others, a CP‐based teaching paradigm in theology/ catechesis is a promising project in the educational scene of the Philippines

    The AMS-RICH velocity and charge reconstruction

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    The AMS detector, to be installed on the International Space Station, includes a Ring Imaging Cerenkov detector with two different radiators, silica aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to provide very precise measurements of velocity and electric charge in a wide range of cosmic nuclei energies and atomic numbers. The detector geometry, in particular the presence of a reflector for acceptance purposes, leads to complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The results of different reconstruction methods applied to test beam data as well as to simulated samples are presented. To ensure nominal performances throughout the flight, several detector parameters have to be carefully monitored. The algorithms developed to fulfill these requirements are presented. The velocity and charge measurements provided by the RICH detector endow the AMS spectrometer with precise particle identification capabilities in a wide energy range. The expected performances on light isotope separation are discussed.Comment: Contribution to the ICRC07, Merida, Mexico (2007); Presenter: F. Bara

    Effects of health and social care spending constraints on mortality in England: a time trend analysis.

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    OBJECTIVE: Since 2010, England has experienced relative constraints in public expenditure on healthcare (PEH) and social care (PES). We sought to determine whether these constraints have affected mortality rates. METHODS: We collected data on health and social care resources and finances for England from 2001 to 2014. Time trend analyses were conducted to compare the actual mortality rates in 2011-2014 with the counterfactual rates expected based on trends before spending constraints. Fixed-effects regression analyses were conducted using annual data on PES and PEH with mortality as the outcome, with further adjustments for macroeconomic factors and resources. Analyses were stratified by age group, place of death and lower-tier local authority (n=325). Mortality rates to 2020 were projected based on recent trends. RESULTS: Spending constraints between 2010 and 2014 were associated with an estimated 45 368 (95% CI 34 530 to 56 206) higher than expected number of deaths compared with pre-2010 trends. Deaths in those aged ≥60 and in care homes accounted for the majority. PES was more strongly linked with care home and home mortality than PEH, with each £10 per capita decline in real PES associated with an increase of 5.10 (3.65-6.54) (p<0.001) care home deaths per 100 000. These associations persisted in lag analyses and after adjustment for macroeconomic factors. Furthermore, we found that changes in real PES per capita may be linked to mortality mostly via changes in nurse numbers. Projections to 2020 based on 2009-2014 trend was cumulatively linked to an estimated 152 141 (95% CI 134 597 and 169 685) additional deaths. CONCLUSIONS: Spending constraints, especially PES, are associated with a substantial mortality gap. We suggest that spending should be targeted on improving care delivered in care homes and at home; and maintaining or increasing nurse numbers

    The RICH detector of the AMS-02 experiment: status and physics prospects

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    The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV. It is equipped with several subsystems, one of which is a proximity focusing RICH detector with a dual radiator (aerogel+NaF) that provides reliable measurements for particle velocity and charge. The assembly and testing of the AMS RICH is currently being finished and the full AMS detector is expected to be ready by the end of 2008. The RICH detector of AMS-02 is presented. Physics prospects are briefly discussed.Comment: 5 pages. Contribution to the 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications (Como 2007). Presenter: Rui Pereir
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