117 research outputs found
Effect of Background, Attitudinal and Social Network Variables on PhD Students’ Academic Performance. A Multimethod Approach
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
A New Fiji-Based Algorithm That Systematically Quantifies Nine Synaptic Parameters Provides Insights into Drosophila NMJ Morphometry
The morphology of synapses is of central interest in neuroscience because of the intimate relation with synaptic efficacy. Two decades of gene manipulation studies in different animal models have revealed a repertoire of molecules that contribute to synapse development. However, since such studies often assessed only one, or at best a few, morphological features at a given synapse, it remained unaddressed how different structural aspects relate to one another. Furthermore, such focused and sometimes only qualitative approaches likely left many of the more subtle players unnoticed. Here, we present the image analysis algorithm ‘Drosophila_NMJ_Morphometrics’, available as a Fiji-compatible macro, for quantitative, accurate and objective synapse morphometry of the Drosophila larval neuromuscular junction (NMJ), a well-established glutamatergic model synapse. We developed this methodology for semi-automated multiparametric analyses of NMJ terminals immunolabeled for the commonly used markers Dlg1 and Brp and showed that it also works for Hrp, Csp and Syt. We demonstrate that gender, genetic background and identity of abdominal body segment consistently and significantly contribute to variability in our data, suggesting that controlling for these parameters is important to minimize variability in quantitative analyses. Correlation and principal component analyses (PCA) were performed to investigate which morphometric parameters are inter-dependent and which ones are regulated rather independently. Based on nine acquired parameters, we identified five morphometric groups: NMJ size, geometry, muscle size, number of NMJ islands and number of active zones. Based on our finding that the parameters of the first two principal components hardly correlated with each other, we suggest that different molecular processes underlie these two morphometric groups. Our study sets the stage for systems morphometry approaches at the well-studied Drosophila NMJThis study was supported by VIDI and TOP grants (917-96-346, 912-12-109) from the
Netherlands Organization for Scientific Research (NWO), by a DCN/Radboud University Medical Center PhD fellowship, by the German Mental Retardation Network funded by the NGFN+ program of the German Federal Ministry of Education and Research (BMBF) and by the European Union's FP7 large scale integrated network Gencodys (HEALTH-241995) to A
Nuevas observaciones sobre la fenologÃa y distribución espacial de los artrópodos en el dosel y sotobosque de un rodal mixto mediterráneo (Collserola, Cataluña), con énfasis en Diptera e Hymenoptera
El presente trabajo es una continuación del monitoreo permanente que se viene realizando desde 2009 en el Parc Natural de la Serra de Collserola, y se centra en la actividad de las familias de Diptera e Hymenoptera muestreadas en un bosque mixto mediterráneo Pinus- Quercus. De abril a octubre de 2012 se realizaron muestreos en el dosel y sotobosque, con un total de 7789 especÃmenes muestreados y resultando Diptera (1393; 17,9%) e Hymenoptera (1039; 13,3%) entre los grupos dominantes en el área. Se encontró una clara estratificación de la fauna, donde el dosel se mostró no solo como el estrato donde se desarrolla el mayor volumen de la actividad de los artrópodos, sino también como el estrato más biodiverso. Estos resultados contrastan con estudios realizados anteriormente en la misma área, donde el sotobosque jugaba un papel dominante sobre el dosel. Las diferencias entre los resultados del primer estudio y los obtenidos en este trabajo evidencian la necesidad de focalizar la atención hacia los diversos factores que marcan la actividad de los artrópodos entre estratos con exposición solar total y parcial.This work is part of permanent monitoring that has been conducted since 2009 in the Serra de Collserola Natural Park, and focuses on the activities of families of Diptera and Hymenoptera sampled in a Mediterranean mixed forest of Pinus-Quercus. From April to October of 2012, samples were taken in the canopy and understory, with a total of 7789 specimens with Diptera (1393; 17.9 %) and Hymenoptera (1039; 13.3 %) among the dominant groups. We found a clear stratification of arthropods, where the canopy showed not only as the layer where the bulk of the activity takes place, but also as the most biodiverse stratum. These results contrast with previous studies in the same area where the understory played a dominant role compared to the canopy. The differences between the results of the first study and those obtained in this study show the need to focus attention on the various factors that influence the activity of arthropods between strata with full and partial sun exposure
Analysing interactions in a teacher network forum: a sociometric approach
This article presents the sociometric analysis of the interactions in a forum of a social network created for the professional development of Portuguese-speaking teachers. The main goal of the forum, which was titled Stricto Sensu, was to discuss the educational value of programmes that joined the distance learning model in Brazil. The empirical study focused on the sociometrie analysis of the social interactions that take place in asynchronous online environments. This approach, according to literature, allows for new means to observe, analyse, and interpret the reality of a new social paradigm. This type of analysis tries to understand the relationship established between the different actors, seeking to verify if the roles they play in both the access to information and the construction of shared knowledge. The data collected allow the researchers to deduce that the indicators used in the analysis are important for understanding and intervening in the dynamics and functioning of the network to propose improvements in its structure and organisation. In the specific case of the aforementioned discussion forum, the results of the sociometrie analysis of the perceived interactions were not surprising, considering that the nature of the topic did not demand deep reflection to contribute to the debate.This work is funded by Portuguese Foundation for Science and Technology under the doctoral grant
SFRH/BD/60677/2009
Oxygen-rich microporous carbons with exceptional hydrogen storage capacity
Porous carbons have been extensively investigated for hydrogen storage but, to date, appear to have an upper limit to their storage capacity. Here, in an effort to circumvent this upper limit, we explore the potential of oxygen-rich activated carbons. We describe cellulose acetatederived carbons that combine high surface area (3800 m2 g-1) and pore volume (1.8 cm3 g-1) that arise almost entirely (> 90%) from micropores, with an oxygen-rich nature. The carbons exhibit enhanced gravimetric hydrogen uptake (8.1 wt% total, and 7.0 wt% excess) at -196 ºC and 20 bar, rising to a total uptake of 8.9 wt% at 30 bar, and exceptional volumetric uptake of 44 g l-1 at 20 bar, and 48 g l-1 at 30 bar. At room temperature they store up to 0.8 wt% (excess) and 1.2 wt% (total) hydrogen at only 30 bar, and their isosteric heat of hydrogen adsorption is above 10 kJ mol-1
Biallelic PI4KA variants cause a novel neurodevelopmental syndrome with hypomyelinating leukodystrophy
Phosphoinositides are lipids that play a critical role in processes such as cellular signalling, ion channel activity and membrane trafficking. When mutated, several genes that encode proteins that participate in the metabolism of these lipids give rise to neurological or developmental phenotypes. PI4KA is a phosphoinositide kinase that is highly expressed in the brain and is essential for life. Here we used whole exome or genome sequencing to identify 10 unrelated patients harbouring biallelic variants in PI4KA that caused a spectrum of conditions ranging from severe global neurodevelopmental delay with hypomyelination and developmental brain abnormalities to pure spastic paraplegia. Some patients presented immunological deficits or genito-urinary abnormalities. Functional analyses by western blotting and immunofluorescence showed decreased PI4KA levels in the patients' fibroblasts. Immunofluorescence and targeted lipidomics indicated that PI4KA activity was diminished in fibroblasts and peripheral blood mononuclear cells. In conclusion, we report a novel severe metabolic disorder caused by PI4KA malfunction, highlighting the importance of phosphoinositide signalling in human brain development and the myelin sheath
Distribució Geogrà fica de l’Esforç Pesquer i Captures de la Flota d’Encerclament Catalana (ICATMAR, 20-02)
23 pages, 15 figuresEn aquest informe es presenta la metodologia d’anà lisi i primers resultats de la distribució geogrà fica de l’esforç i captures de la flota d’encerclament catalana a partir de dades VMS (Vessel Monitoring System) i ha estat realitzat per l’Institut Català de Recerca per a la Governança del Mar (ICATMAR), un òrgan de cooperació entre la Direcció General de Pesca i Afers MarÃtims del Departament d’Agricultura, Ramaderia, Pesca i Alimentació (DARP) de la Generalitat de Catalunya i l’Institut de Ciències del Mar (ICM) del Consejo Superior de Investigaciones CientÃficas (CSIC)Peer reviewe
Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers
Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants
Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers
Modern humans have populated Europe for more than 45,000 years. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants.Open access funding provided by Max Planck Society. This project has received funding by the European Research Council under the European Union’s Horizon 2020 research and innovation programme under grant agreements no. 803147-RESOLUTION (to S.T.), no. 771234-PALEoRIDER (to W.H.), no. 864358 (to K.M.), no. 724703 and no. 101019659 (to K.H.). K.H. is also supported by the Deutsche Forschungsgemeinschaft (DFG FOR 2237). E.A. has received funding from the Van de Kamp fonds. PACEA co-authors of this research benefited from the scientific framework of the University of Bordeaux’s IdEx Investments for the Future programme/GPR Human Past. A.G.-O. is supported by a Ramón y Cajal fellowship (RYC-2017-22558). L. Sineo, M.L. and D.C. have received funding from the Italian Ministry of University and Research (MUR) PRIN 2017 grants 20177PJ9XF and 20174BTC4R_002. H. Rougier received support from the College of Social and Behavioral Sciences of CSUN and the CSUN Competition for RSCA Awards. C.L.S. and T. Saupe received support from the European Union through the European Regional Development Fund (project no. 2014-2020.4.01.16-0030) and C.L.S. received support from the Estonian Research Council grant PUT (PRG243). S. Shnaider received support from the Russian Science Foundation (no. 19-78-10053).Peer reviewe
Fostering support for non-democratic rule? Controlled political liberalization and popular support for non-democratic regimes
When the Cold War ended, many non-democratic regimes across the globe embarked on a course of controlled political liberalization, hoping to stabilize their autocratic rule by mitigating popular demands for democratization and increasing regime legitimacy. But does this strategy actually work? This article uses multi-level analyses to examine how the degree of political liberalization affects regime support in non-democratic political systems and to ascertain which mechanisms underlie this effect. Drawing on aggregate measures of political liberalization and comparative survey data from four regional survey projects and 31 non-democracies, the study's results indicate that the degree of liberalization has no decisively positive effect on regime support, suggesting controlled political liberalization might not be an effective legitimizing strategy after all.Nach Ende des Kalten Krieges haben viele nicht-demokratische Regime weltweit einen Kurs der begrenzten politischen Öffnung eingeschlagen, um öffentliche Forderungen nach Demokratisierung zu entschärfen und auf diese Weise die Legitimität ihrer autokratischen Herrschaft zu erhöhen. Doch ist diese Strategie tatsächlich effektiv? Der Beitrag verwendet Mehrebenenanalysen, um zu untersuchen wie der Grad an politischer Öffnung die Regimerunterstützung in nicht-demokratischen politischen Systemen beeinflusst. Auf Basis von Aggregatmaßen zur politischen Öffnung und Individualdaten aus vier regionalen Umfrageprojekten und 31 Autokratien kann kein klarer positiver Effekt des Grads der politischen Öffnung auf die Regimeunterstützung nachgewiesen werden, was eine begrenzte politische Öffnung als wenig effektive Legitimationsstrategie erscheinen lässt
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