1,789 research outputs found
La cultura i el clima organitzacional a l'Educació Secundària
La importància de l'educació secundària per al desenvolupament personal i social i les diferents problemàtiques que actualment presenta obliguen a fer diferents actuacions (polítiques, legals, científiques i tècniques) que permetin optimitzar i millorar la realitat actual. En el present article exposem resumidament les principals característiques d'una recerca que s'ha desenvolupat amb l'objectiu de millorar el funcionament dels centres d'educació secundària (IES) a partir del diagnòstic detallat de les variables cultura i clima organitzatius. Presentem una recerca desenvolupada per un equip de treball format per professors i directors d'IES, professionals de l'administració educativa i acadèmics del món universitari. Això ens ha permès fer un plantejament global i plural de la realitat i coordinar els diferents agents implicats i els professionals de l'àmbit. Partim presentant molt breument el marc teòric de referència. En segon lloc es determinen les bases metodològiques i els aspectes empírics de la recerca. A més del disseny dels instruments per al diagnòstic de la cultura i el clima dels centres. Finalment, es presenten resumidament els resultats i les principals conclusions de l'estudi.La importancia de la educación secundaria para el desarrollo personal y social y las diversas disfunciones y problemas que presenta obligan a realizar diferentes actuaciones (políticas, legales, científicas y técnicas) que permitan superar y optimizar la actual situación. En el presente artículo se exponen de forma sintética los principales rasgos y características de una investigación que ha tenido como objeto de estudio la mejora del funcionamiento de los centros de educación secundaria (IES) a partir del diagnóstico detallado de las variables de su clima y cultura institucional. Presentamos una investigación desarrollada por un equipo de trabajo configurado por profesores y directores de IES, profesionales de la administración educativa y académicos de la universidad que ha permitido plantear un enfoque global, plural y coordinado de los diferentes agentes implicados y profesionales del ámbito. Partimos presentando de forma sucinta el marco teórico en el que hemos basado nuestra investigación. Seguidamente se determinan las bases metodológicas y de carácter más empírico, destacando por un lado el estudio de casos como metodología de trabajo y el diseño o aplicación de instrumentos para el análisis y el diagnóstico del clima y cultura institucional. Finalmente se presentan de forma resumida los resultados y las principales conclusiones del estudio.The importance of the education secondary for the personal and social development and the diverse problems that present/display force to make different performances (political, legal, scientific and technical) that allows to surpass and to optimize the present one situation. In the present article they are exposed of synthetic form the main characteristics and characteristics of one investigation that it has had as study object the improvement of the operation of the centers of secondary education (IES) from the detailed diagnosis of the variables of its climate and institutional culture. We presented/displayed an investigation developed by a work party formed by professors and directors of IES, academic professionals of the educative administration and of university that has allowed to raise a global approach, plural and coordinated of the different professional implied agents y from the scope. We started off presenting/displaying of the theoretical frame on which we have based our investigation. Next the methodologic bases and of more empirical character are determined, emphasizing by a side the study of cases like work methodology and design or application of instruments for the analysis and diagnosis of the climate and institutional culture. Finally the results appear of summarized form and the main conclusions of the study
A 2-D π–π dimer model system to investigate structure-charge transfer relationships in rubrene
© The Royal Society of Chemistry 2019Rubrene (5,6,11,12-tetraphenyltetracene) is undoubtedly one of the best performing organic charge transfer mediating materials, with experimentally determined mobilities up to 40 cm2 V−1 s−1. Consequently, there has been increasing interest by means of crystal engineering in trying to generate rubrene-based materials with analogous or even superior conducting properties. Often, experimental measurements are carried out in thin film architectures of these materials, where measured properties can be detrimentally impacted by device manufacture rather than intrinsic charge transfer properties of the material. The latter results in discarding potential good performers. To address these concerns, we report a two-dimensional model system that will allow researchers to predict charge transfer properties of their materials solely requiring the coordinates of the π–π stacking motifs. We envisaged this study to be of significant interest to the increasingly large community of materials scientists devoted to the realisation of improved organic charge mediating materials and particularly to those engaged in exploiting rubrene-based architectures.Peer reviewedFinal Accepted Versio
Detection of an optical transient following the 13 March 2000 short/hard gamma-ray burst
We imaged the error box of a gamma-ray burst of the short (0.5 s), hard type
(GRB 000313), with the BOOTES-1 experiment in southern Spain, starting 4 min
after the gamma-ray event, in the I-band. A bright optical transient (OT
000313) with I = 9.4 +/- 0.1 was found in the BOOTES-1 image, close to the
error box (3-sigma) provided by BATSE. Late time VRIK'-band deep observations
failed to reveal an underlying host galaxy. If the OT 000313 is related to the
short, hard GRB 000313, this would be the first optical counterpart ever found
for this kind of events (all counterparts to date have been found for bursts of
the long, soft type). The fact that only prompt optical emission has been
detected (but no afterglow emission at all, as supported by theoretical models)
might explain why no optical counterparts have ever been found for short, hard
GRBs.This fact suggests that most short bursts might occur in a low-density
medium and favours the models that relate them to binary mergers in very
low-density enviroments.Comment: Revised version. Accepted for publication in Astronomy and
Astrophysics Letters, 5 pages, 3 figure
INTEGRAL and XMM-Newton observations of the weak GRB 030227
We present INTEGRAL and XMM-Newton observations of the prompt gamma-ray
emission and the X-ray afterglow of GRB030227, the first GRB for which the
quick localization obtained with the INTEGRAL Burst Alert System (IBAS) has led
to the discovery of X-ray and optical afterglows. GRB030227 had a duration of
about 20 s and a peak flux of 1.1 photons cm^-2 s^-1 in the 20-200 keV energy
range. The time averaged spectrum can be fit by a single power law with photon
index about 2 and we find some evidence for a hard to soft spectral evolution.
The X-ray afterglow has been detected starting only 8 hours after the prompt
emission, with a 0.2-10 keV flux decreasing as t^-1 from 1.3x10e-12 to 5x10e-13
erg cm^-2 s^-1. The afterglow spectrum is well described by a power law with
photon index 1.94+/-0.05 modified by a redshifted neutral absorber with column
density of several 10e22 cm^-2. A possible emission line at 1.67 keV could be
due to Fe for a redshift z=3, consistent with the value inferred from the
absorption.Comment: 16 pages, 5 figures, latex, Accepted for publication in The
Astrophysical Journal Letter
A semi-grand canonical Monte Carlo simulation model for ion binding to ionizable surfaces: proton binding of carboxylated latex particles as a case study
In this paper, we present a computer simulation study of the ion binding process at an ionizable surface using a semi-grand canonical Monte Carlo method that models the surface as a discrete distribution of charged and neutral functional groups in equilibrium with explicit ions modelled in the context of the primitive model. The parameters of the simulation model were tuned and checked by comparison with experimental titrations of carboxylated latex particles in the presence of different ionic strengths of monovalent ions. The titration of these particles was analysed by calculating the degree of dissociation of the latex functional groups vs. pH curves at different background salt concentrations. As the charge of the titrated surface changes during the simulation, a procedure to keep the electroneutrality of the system is required. Here, two approaches are used with the choice depending on the ion selected to maintain electroneutrality: counterion or coion procedures. We compare and discuss the difference between the procedures. The simulations also provided a microscopic description of the electrostatic double layer (EDL) structure as a function of p H and ionic strength. The results allow us to quantify the effect of the size of the background salt ions and of the surface functional groups on the degree of dissociation. The non-homogeneous structure of the EDL was revealed by plotting the counterion density profiles around charged and neutral surface functional groups
Sal k 5, a member of the widespread Ole e 1-like protein family, is a new allergen of Russian thistle (Salsola kali) pollen.
Salsola kali is an Amaranthaceae weed with important repercussions for pollinosis in temperate areas. Ole e 1-like members are relevant allergens in pollen from different species. We aimed to characterize and produce as recombinant allergen S. kali Ole e 1-like protein.
METHODS:The natural allergen was purified at homogeneity after three chromatographic steps. Specific cDNA was sequenced and expressed in Pichia pastoris yeast. Structural relationships of natural and recombinant forms were carried out by 2D electrophoresis and spectroscopic analyses. Its immunological relevance was analyzed by ELISA and immunoblotting using an IgG antiserum and monoclonal antibodies specific to Ole e 1, as well as sera from 57 allergic patients recruited from two Spanish regions where this pollinosis is frequent.
RESULTS:The purified allergen, Sal k 5, is an acidic glycoprotein of 151 amino acid residues and 17,628 Da of molecular mass. Its amino acid sequence exhibits 68 and 32% identity with the allergens of Che a 1 and Ole e 1, respectively. The recombinant protein was correctly processed and its structural and immunologic equivalence to the natural form was proven. A sensitization frequency between 30 and 40% was observed in pollinic patients from the center and east coast of Spain.
CONCLUSIONS:Sal k 5 is a member of the Ole e 1-like protein family which can be considered an important allergen from S. kali. Its inclusion in diagnosis protocols would allow the accurate defining of patients allergic to this pollen
Twist and shout: a surprising synergy between aryl and N-substituents defines the computed charge transport properties in a series of crystalline diketopyrrolopyrroles
This is the Accepted Manuscript version of an article accepted for publication in CyrstEngComm. Under embargo. Embargo end date: 22 November 2017. Jesus Calvo-Castrp, Sebastian Macza, Connor Thomson, Graeme Morris, Alan R. Kennedy and Callum J. McHugh, ‘Twist and shout: a surprising synergy between aryl and N-substituents defines the computed charge transport properties in a series of crystalline diketopyrrolopyrroles’, CrysEngComm, Vol 18(48): 9382-9390, first published online 22 November 2016, available at doi: 10.1039/C6CE02261HThe influence of systematic variation of aryl and N-substitution on predicted charge transport behaviour in a series of crystalline diketopyrrolopyrroles is evaluated. A correct combination of substituents is revealed to maximise those properties which dictate device performance in organic single crystals based upon this structural motif. For electron transport, furan and N-alkyl substitution emerge as optimal molecular design strategies, whilst phenyl structures bearing N-benzyl substituents are shown to offer the most significant promise as highly sought after crystalline hole transport materials.Peer reviewedFinal Accepted Versio
Lifestyle and Health among Spanish University Students: Differences by Gender and Academic Discipline
Today the need to analyze health behaviour from a gender perspective is as imminent as ever, particularly at university, where the number of women who register is on the rise and has exceeded the number of male students worldwide. We carried out a prevalence study aimed at analyzing Spanish university students’ lifestyles and identify differences according to gender and academic discipline. Of 3,646 eligible subjects doing university courses related to health (Group A), education (Group B) and other professions (Group C), 985 (27.0%) participated in the study. Information was elicited about their physical activity level, disturbed eating attitudes, consumption of alcohol, tobacco and illegal substances. Prevalence and Odds Ratios (OR) were calculated according to sex and kind of academic discipline. The obtained data confirmed that only 27.4% of the students were considered as sufficiently active, while 14.9% of them suffered from disturbed eating attitudes (DEA). Women were particularly less active (OR 0.46 (0.32–0.66); <em>p</em> < 0.0001), and more sedentary than men (OR 1.40 (1.00–1.97); <em>p</em> = 0.03). Binge drinking was more frequent in female than in male students (OR 1.79 (1.29–2.47); <em>p</em> = 0.0004). A third of the analyzed sample admitted that they had used illegal substances, while a lower consumption prevalence was found in women (OR 0.53 (0.40–0.71); <em>p</em> < 0.0001). The studied population was not very active (27.4%), especially women (OR = 0.45). Therefore, it seems that Spanish university students lead an unhealthy lifestyle, a situation which seems more conspicuous amongst females
Competition effects in cation binding to humic acid: Conditional affinity spectra for fixed total metal concentration conditions
Information on the Pb and Cd binding to a purified Aldrich Humic Acid (HA) is obtained from the influence of different fixed total metal concentrations on the acid- base titrations of this ligand. NICA (Non-Ideal Competitive Adsorption) isotherm has been used for a global quantitative description of the binding, which has then been interpreted by plotting the Conditional Affinity Spectra of the H+ binding at fixed total metal concentrations (CAScTM). This new physicochemical tool, here introduced, allows the interpretation of binding results in terms of distributions of proton binding energies. A large increase in the acidity of the phenolic sites as the total metal concentration increases, especially in presence of Pb, is revealed from the shift of the CAScTM towards lower affinities. The variance of the CAScTM distribution, which can be used as a direct measure of the heterogeneity, also shows a significant dependence on the total metal concentration. A discussion of the factors that influence the heterogeneity of the HA under the conditions of each experiment is provided, so that the smoothed pattern exhibited by the titration curves can be justified
Global characteristics of GRBs observed with INTEGRAL and the inferred large population of low-luminosity GRBs
INTEGRAL has two sensitive gamma-ray instruments that have detected 46
gamma-ray bursts (GRBs) up to July 2007. We present the spectral, spatial, and
temporal properties of the bursts in the INTEGRAL GRB catalogue using data from
the imager, IBIS, and spectrometer, SPI. Spectral properties of the GRBs are
determined using power-law, Band model and quasithermal model fits to the
prompt emission. Spectral lags, i.e. the time delay in the arrival of
low-energy gamma-rays with respect to high-energy gamma-rays, are measured for
31 of the GRBs. The photon index distribution of power-law fits to the prompt
emission spectra is consistent with that obtained by Swift. The peak flux
distribution shows that INTEGRAL detects proportionally more weak GRBs than
Swift because of its higher sensitivity in a smaller field of view. The all-sky
rate of GRBs above ~0.15 ph cm^-2 s^-1 is ~1400 yr^-1 in the fully coded field
of view of IBIS. Two groups are identified in the spectral lag distribution,
one with short lags <0.75 s (between 25-50 keV and 50-300 keV) and one with
long lags >0.75 s. Most of the long-lag GRBs are inferred to have low redshifts
because of their long spectral lags, their tendency to have low peak energies
and their faint optical and X-ray afterglows. They are mainly observed in the
direction of the supergalactic plane with a quadrupole moment of
Q=-0.225+/-0.090 and hence reflect the local large-scale structure of the
Universe. The rate of long-lag GRBs with inferred low luminosity is ~25% of
Type Ib/c supernovae. Some of these bursts could be produced by the collapse of
a massive star without a supernova or by a different progenitor, such as the
merger of two white dwarfs or a white dwarf with a neutron star or black hole,
possibly in the cluster environment without a host galaxy.Comment: 22 pages, 13 figures and appendix, accepted for publication in A&A,
added and updated reference
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