Preservice Generalist Teachers Enlightened Approach to Teaching Physical Education through Teacher Biography.

This paper describes a new learning experience, which was introduced following an examination of the literature regarding preservice primary school teachers’ (PPST) notions of their past experience in Physical Education (PE) (Elliott 2013). PPSTs were given the opportunity to recognise, reflect, interrogate and reframe a critical incident from their schooling in PE or Sport. This exercise was designed to enlighten students about their own schooling and the potential impact this event may have on pre-conceived ideas and opinions about teaching PE. Students (N=214) enrolled in off and on campus mode, of a preservice teacher education program in a university located in regional NSW, were asked to provide information about, and to analyse, an incident, either positive or negative that occurred in PE or Sport during their primary or secondary school years. In addition, students were encouraged to reframe the incident and to seek out alternative actions that could have influenced the outcome. The aim was to encourage reflection about how preconceived notions pertaining to PE might be dealt within their present position as a preservice teacher. The PPSTs scripts were analysed using the Leximancer text mining software (Smith, 2000). Findings from the analysis provided themes and concepts, which suggest a similarity for both, off and on campus, males and females. However, there are some subtle differences between the cohorts that may be due to an age or experience

Absorbed dose evaluation of Auger electron-emitting radionuclides: impact of input decay spectra on dose point kernels and S-values

The aim of this study was to investigate the impact of decay data provided by the newly developed stochastic atomic relaxation model BrIccEmis on dose point kernels (DPKs - radial dose distribution around a unit point source) and S-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE) emitting radionuclides, namely 67Ga, 80mBr, 89Zr, 90Nb, 99mTc, 111In, 117mSn, 119Sb, 123I, 124I, 125I, 135La, 195mPt and 201Tl. Radiation spectra were based on the nuclear decay data from the medical internal radiation dose (MIRD) RADTABS program and the BrIccEmis code, assuming both an isolated-atom and condensed-phase approach. DPKs were simulated with the PENELOPE Monte Carlo (MC) code using event-by-event electron and photon transport. S-values for concentric spherical cells of various sizes were derived from these DPKS using appropriate geometric reduction factors. The number of Auger and Coster-Kronig (CK) electrons and x-ray photons released per nuclear decay (yield) from MIRD-RADTABS were consistently higher than those calculated using BrIccEmis. DPKs for the electron spectra from BrIccEmis were considerably different from MIRD-RADTABS in the first few hundred nanometres from a point source where most of the Auger electrons are stopped. S-values were, however, not significantly impacted as the differences in DPKS in the sub-micrometre dimension were quickly diminished in larger dimensions. Overestimation in the total AE energy output by MIRD-RADTABS leads to higher predicted energy deposition by AE emitting radionuclides, especially in the immediate vicinity of the decaying radionuclides. This should be taken into account when MIRD-RADTABS data are used to simulate biological damage at nanoscale dimensions.Comment: 27 pages, 4 figures, 3 table

Polysialic Acid Is Required for Dopamine D2 Receptor-Mediated Plasticity Involving Inhibitory Circuits of the Rat Medial Prefrontal Cortex

Decreased expression of dopamine D2 receptors (D2R), dysfunction of inhibitory neurotransmission and impairments in the structure and connectivity of neurons in the medial prefrontal cortex (mPFC) are involved in the pathogenesis of schizophrenia and major depression, but the relationship between these changes remains unclear. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a plasticity-related molecule, may serve as a link. This molecule is expressed in cortical interneurons and dopamine, via D2R, modulates its expression in parallel to that of proteins related to synapses and inhibitory neurotransmission, suggesting that D2R-targeted antipsychotics/antidepressants may act by affecting the plasticity of mPFC inhibitory circuits. To understand the role of PSA-NCAM in this plasticity, rats were chronically treated with a D2R agonist (PPHT) after cortical PSA depletion. PPHT-induced increases in GAD67 and synaptophysin (SYN) neuropil expression were blocked when PSA was previously removed, indicating a role for PSA-NCAM in this plasticity. The number of PSA-NCAM expressing interneuron somata also increased after PPHT treatment, but the percentages of these cells belonging to different interneuronal subpopulations did not change. Cortical pyramidal neurons did not express PSA-NCAM, but puncta co-expressing this molecule and parvalbumin could be found surrounding their somata. PPHT treatment increased the number of PSA-NCAM and parvalbumin expressing perisomatic puncta, but decreased the percentage of parvalbumin puncta that co-expressed SYN. PSA depletion did not block these effects on the perisomatic region, but increased further the number of parvalbumin expressing puncta and increased the percentage of puncta co-expressing SYN and parvalbumin, suggesting that the polysialylation of NCAM may regulate perisomatic inhibition of mPFC principal neurons. Summarizing, the present results indicate that dopamine acting on D2R influences structural plasticity of mPFC interneurons and point to PSA-NCAM as a key player in this remodeling

Monte Carlo Simulation of Electron Backscattering in Solids Using a General-Purpose Computer Code

A Monte Carlo study of backscattering of kilovolt electrons in solids, a process of primary importance in electron microscopy and surface analytical techniques, is carried out. Simulations have been performed using the general-purpose simulation code PENELOPE (an acronym for Penetration and ENErgy LOss of Positrons and Electrons ), which generates electron-photon showers in arbitrary materials. A systematic comparison of results from PENELOPE with available experimental data, and with results from simulations with a much more sophisticated code, is given for electron beams with energies between 2.5 and 60 keV and elemental solids with atomic numbers Z = 4 to 92. It is concluded that PENELOPE gives a reliable description of the backscattering process, even for relatively low electron energies and thin targets

Photochromic mechanism in oxygen-containing yttrium hydride thin films: An optical perspective

Oxygen-containing yttrium hydride thin films exhibit photochromic behavior: Transparent thin films reversibly switch from a transparent state to a photodarkened state after being illuminated with UV or blue light. From optical spectrophotometry and ellipsometry measurements of the transparent state and photodarkened state, it is concluded that the photochromic effect can be explained by the gradual growth, under illumination, of metallic domains within the initial wide-band-gap semiconducting lattice. This conclusion is supported by Raman measurements

Oxygen vacancy related distortions in rutile TiO_2 nanoparticles: a combined experimental and theoretical study

The effects of doubly ionized oxygen vacancies [(V_O)ˆ(2+)]on the electronic structure and charge distribution in rutile TiO_2 are studied by combining first-principles calculations based on density functional theory and experimental results from x-ray photoelectron and x-ray absorption measurements carried out in synchrotron facilities on rutile TiO_2 nanoparticles. The generalized gradient approximation of the Perdew-Burke-Ernzerhof functional has demonstrated its suitability for the analysis of the [(V_O)ˆ(2+)]defects in rutile TiO_2. It has been found that the presence of empty electronic states at the conduction band shifted ̴1 eV from t_(2g) and e_(g) states can be associated with local distortions induced by [(V_O)ˆ(2+)]defects, in good agreement with Gauss-Lorentzian band deconvolution of experimental O K-edge spectra. The asymmetry of t(2g) and e(g) bands at the O-K edge has been associated with [(V_O)ˆ(2+)], which can enrich the understanding of studies where the presence of these defects plays a key role, as in the case of doped TiO_2

Puesta a punto de una metodología que permita evaluar el efecto de cantidades perfectamente conocidas de O2 en diferentes vinos tintos, sin la interferencia del O2 atmosférico.

El estudio de los procesos de oxidación-reducción en el vino es un campo en el cuál, aún a día de hoy, existen grandes lagunas acerca de determinados aspectos. Por ello, el objetivo final de este trabajo consiste en poder adicionar de forma perfectamente controlada cantidades conocidas de O2 en botellas de 150 mL. De esta manera,  después de 6 meses a 25ºC, se pretenderá caracterizar: 1) el estado redox del vino, 2) los sistemas catalíticos, 3) el estado aromático del vino, 4) aquellos precursores involucrados en cambios aromáticos y 5) el aroma. Para ello se han escogido 16 vinos tintos con diferente tendencia oxido-reductiva. Para poder realizar este estudio ha sido imprescindible disponer de una caja de guantes con atmósfera de Argón, que asegura un nivel de O2  inferior a 1 ppm. Otro de los requisitos ha sido obtener un sistema de almacenaje prácticamente impermeable alO2 atmosférico. Para ello se ha partido de un sistema comercial (Sigma-Aldrich), que constaba de una chapa con un orificio, un septum, (a través del cual se adiciona con una jeringa de gases la correspondiente cantidad de O2) y un tapón de rosca externo. Este sistema comercial demostró funcionar estrepitosamente, ya que permitía la entrada continua de O2 atmosférico al vino, y por tanto después de tres meses no se encontraron diferencias significativas entre los diferentes niveles de adición de O2, ya que todos los vinos estaban extremadamente oxidados. Para solucionar este problema se ha probado con distintos dispositivos y modificaciones de este sistema comercial, para finalmente encontrar uno impermeable al O2 atmosférico que ha permitido llevar a cabo las adiciones de forma correcta. Este trabajo pretende ilustrar dicho proceso y sistema de trabajo

Puesta a punto de una metodología que permita evaluar el efecto de cantidades perfectamente conocidas de O2 en diferentes vinos tintos, sin la interferencia del O2 atmosférico.

El estudio de los procesos de oxidación-reducción en el vino es un campo en el cuál, aún a día de hoy, existen grandes lagunas acerca de determinados aspectos. Por ello, el objetivo final de este trabajo consiste en poder adicionar de forma perfectamente controlada cantidades conocidas de O2 en botellas de 150 mL. De esta manera,  después de 6 meses a 25ºC, se pretenderá caracterizar: 1) el estado redox del vino, 2) los sistemas catalíticos, 3) el estado aromático del vino, 4) aquellos precursores involucrados en cambios aromáticos y 5) el aroma. Para ello se han escogido 16 vinos tintos con diferente tendencia oxido-reductiva. Para poder realizar este estudio ha sido imprescindible disponer de una caja de guantes con atmósfera de Argón, que asegura un nivel de O2  inferior a 1 ppm. Otro de los requisitos ha sido obtener un sistema de almacenaje prácticamente impermeable alO2 atmosférico. Para ello se ha partido de un sistema comercial (Sigma-Aldrich), que constaba de una chapa con un orificio, un septum, (a través del cual se adiciona con una jeringa de gases la correspondiente cantidad de O2) y un tapón de rosca externo. Este sistema comercial demostró funcionar estrepitosamente, ya que permitía la entrada continua de O2 atmosférico al vino, y por tanto después de tres meses no se encontraron diferencias significativas entre los diferentes niveles de adición de O2, ya que todos los vinos estaban extremadamente oxidados. Para solucionar este problema se ha probado con distintos dispositivos y modificaciones de este sistema comercial, para finalmente encontrar uno impermeable al O2 atmosférico que ha permitido llevar a cabo las adiciones de forma correcta. Este trabajo pretende ilustrar dicho proceso y sistema de trabajo

Development of a GPU-based Monte Carlo dose calculation code for coupled electron-photon transport

Monte Carlo simulation is the most accurate method for absorbed dose calculations in radiotherapy. Its efficiency still requires improvement for routine clinical applications, especially for online adaptive radiotherapy. In this paper, we report our recent development on a GPU-based Monte Carlo dose calculation code for coupled electron-photon transport. We have implemented the Dose Planning Method (DPM) Monte Carlo dose calculation package (Sempau et al, Phys. Med. Biol., 45(2000)2263-2291) on GPU architecture under CUDA platform. The implementation has been tested with respect to the original sequential DPM code on CPU in phantoms with water-lung-water or water-bone-water slab geometry. A 20 MeV mono-energetic electron point source or a 6 MV photon point source is used in our validation. The results demonstrate adequate accuracy of our GPU implementation for both electron and photon beams in radiotherapy energy range. Speed up factors of about 5.0 ~ 6.6 times have been observed, using an NVIDIA Tesla C1060 GPU card against a 2.27GHz Intel Xeon CPU processor.Comment: 13 pages, 3 figures, and 1 table. Paper revised. Figures update

Nocturnal but not Diurnal Hypertension Is Associated to Insulin Resistance Markers in Subjects with Normal or Mildly Elevated Office Blood Pressure

Objective: The aim was to evaluate the relationships among insulin resistance markers and nocturnal and diurnal hypertension in normotensive or mildly untreated hypertensive adults. Methods: The study was performed in both female and male adults referred to the Cardiometabolic Unit of the Hospital San Martín, La Plata, Argentina, in order to perform an ambulatory blood pressure measurement (ABPM) for the evaluation of a possible hypertensive disorder. The population was stratified according to their ABPM in: 1-presence or absence of diurnal hypertension and 2-presence or absence of nocturnal hypertension; both conditions were analyzed separately. Fasting plasma insulin (FPI), homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C) ratio were used as surrogate markers of insulin resistance and compared among subjects with vs. without diurnal or nocturnal hypertension. Results: One hundred and five patients, 55 women, 47 (11) years old, and 50 men, 44 (16) years old, were included. Diurnal and nocturnal hypertension were found in 60% and 64% of the sample, respectively. There were no significant differences among the levels of insulin resistance markers between individuals with or without diurnal hypertension. In contrast, individuals with nocturnal hypertension were more insulin resistant irrespectively of whether they were evaluated using FPI (P = 0.016), HOMA-IR (P = 0.019), or TG/HDL-C ratio (P = 0.011); FPI differences remained significant after adjustment for sex, age, and obesity indicators (P = 0.032). Conclusions: Nocturnal but not diurnal hypertension was related to higher levels of 3 insulin resistance markers in normotensive and untreated mildly hypertensive adults; this relationship seems partially independent of obesity.Facultad de Ciencias Médica