Implementación de un Modelo de medición del Clima Organizacional desde la perspectiva de los estudiantes en la Universidad Nacional de Mar del Plata: algunas conclusiones derivadas de sus resultados

El diagnóstico de las condiciones asociadas al clima organizacional que contribuyen a la conflictividad institucional y al desgranamiento de la matricula, permite generar acciones estratégicas que incorporen el reconocimiento de estas condiciones e intenten modificarlas. Dado que es esencial saber que piensan y sienten los diferentes actores, nos centramos en la perspectiva de los estudiantes de la Facultad de Ciencias Económicas y Sociales en su carácter de participantes y en los diferentes roles que les toca actuar, determinando aquellas variables objetivas que puedan incidir negativamente sobre la percepción que tienen de la calidad de vida. Esta calidad influirá en el desempeño y por lo tanto en su satisfacción comprometiéndose así su permanencia estable, productiva y saludable. El modelo de medición del clima organizacional que presentamos abordan las “percepciones de los actores”, y parte de encuestar a éstos para conocer como perciben las condiciones en que actúan. De esta manera se abordan dimensiones como la participación, organización, gestión y liderazgo, capacitación para el desempeño, reconocimiento, relaciones horizontales y condiciones físicas, considerándolas como aquellas más relevantes a los efectos del diagnóstico. En el X Encuentro compartimos el instrumento diseñado en el marco de un proyecto de investigación. En esta oportunidad pretendemos compartir los primeros resultados, reflexiones y conclusiones obtenidas luego de administrar la encuesta a una muestra estadísticamente representativa de alumnos de la Facultad de Ciencias Económicas y Sociales de la UNMdP. Esperamos que el análisis e interpretación de los datos obtenidos permitan generar un mejoramiento en la calidad de la gestión de la institución, facilitando la generación de políticas de desarrollo institucional

Phase transitions in two dimensions - the case of Sn adsorbed on Ge(111) surfaces

Accurate atomic coordinates of the room-temperature (root3xroot3)R30degree and low-temperature (3x3) phases of 1/3 ML Sn on Ge(111) have been established by grazing-incidence x-ray diffraction with synchrotron radiation. The Sn atoms are located solely at T4-sites in the (root3xroot3)R30degree structure. In the low temperature phase one of the three Sn atoms per (3x3) unit cell is displaced outwards by 0.26 +/- 0.04 A relative to the other two. This displacement is accompanied by an increase in the first to second double-layer spacing in the Ge substrate.Comment: RevTeX, 5 pages including 2 figure

Measurement of IEC Groups and Subgroups Using Advanced Spectrum Estimation Methods

The International Electrotechnical Commission (IEC) standards characterize the waveform distortions in power systems with the amplitudes of harmonic and interharmonic groups and subgroups. These groups/subgroups utilize the waveform spectral components obtained from a fixed frequency resolution discrete Fourier transform (DFT). Using the IEC standards allows for a compromise among the different goals, such as the needs for accuracy, simplification, and unification. In some cases, however, the power-system waveforms are characterized by spectral components that the DFT cannot capture with enough accuracy due to the fixed frequency resolution and/or the spectral leakage phenomenon. This paper investigates the possibility of a group/subgroup evaluation using the following advanced spectrum estimation methods: adaptive Prony, estimation of signal parameters via rotational invariance techniques, and root MUltiple-SIgnal Classification (MUSIC). These adaptive methods use variable lengths of time windows of analysis to ensure the best fit of the waveforms; they are not characterized by the fixed frequency resolution and do not suffer from the spectral leakage phenomenon. This paper also presents the results of the applications of these methods to three test waveforms, to current and voltage waveforms obtained from simulations of a real dc arc-furnace plant, and to waveforms measured at the point of common coupling of the low-voltage network supplying a high-performance laser printer

FIRST experiment: Fragmentation of Ions Relevant for Space and Therapy

Nuclear fragmentation processes are relevant in different fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at SIS accelerator of GSI laboratory in Darmstadt, has been designed for the measurement of different ions fragmentation cross sections at different energies between 100 and 1000 MeV/nucleon. The experiment is performed by an international collaboration made of institutions from Germany, France, Italy and Spain. The experimental apparatus is partly based on an already existing setup made of the ALADIN magnet, the MUSIC IV TPC, the LAND2 neutron detector and the TOFWALL scintillator TOF system, integrated with newly designed detectors in the interaction Region (IR) around the carbon removable target: a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger for detection of light fragments emitted at large angles (KENTROS). The scientific program of the FIRST experiment started on summer 2011 with the study of the 400 MeV/nucleon 12C beam fragmentation on thin (8mm) carbon targe

Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction

At a coverage of about 1/3 monolayer, Sn deposited on Ge(111) below 550 forms a metastable (sqrt3 x sqrt3)R30 phase. This phase continuously and reversibly transforms into a (3x3) one, upon cooling below 200 K. The photoemission spectra of the Sn 4d electrons from the (3x3)-Sn/Ge(111) surface present two components which are attributed to inequivalent Sn atoms in T4 bonding sites. This structure has been explored by photoelectron diffraction experiments performed at the ALOISA beamline of the Elettra storage ring in Trieste (Italy). The modulation of the intensities of the two Sn components, caused by the backscattering of the underneath Ge atoms, has been measured as a function of the emission angle at fixed kinetic energies and viceversa. The bond angle between Sn and its nearest neighbour atoms in the first Ge layer (Sn-Ge1) has been measured by taking polar scans along the main symmetry directions and it was found almost equivalent for the two components. The corresponding bond lengths are also quite similar, as obtained by studying the dependence on the photoelectron kinetic energy, while keeping the photon polarization and the collection direction parallel to the Sn-Ge1 bond orientation (bond emission). A clear difference between the two bonding sites is observed when studying the energy dependence at normal emission, where the sensitivity to the Sn height above the Ge atom in the second layer is enhanced. This vertical distance is found to be 0.3 Angstroms larger for one Sn atom out of the three contained in the lattice unit cell. The (3x3)-Sn/Ge(111) is thus characterized by a structure where the Sn atom and its three nearest neighbour Ge atoms form a rather rigid unit that presents a strong vertical distortion with respect to the underneath atom of the second Ge layer.Comment: 10 pages with 9 figures, added reference

New Techniques in Diagnostic X-ray Imaging: A Simulation Tool and Experimental Findings

AbstractAbsorption X-ray imaging is a well-established technique. However it is still a challenging task in its search for a compromise between the need for high spatial resolution and high contrast and the request to keep the dose delivered to the patient within acceptable values. New imaging techniques are under investigation, like the use of new X-ray sources, phase contrast imaging or K-edge imaging. Monte Carlo or analytic simulations are often the best way to test and predict the effectiveness of these techniques. A new simulation tool for X-ray imaging will be presented together with some applications to the characterization of new X-ray sources, in-line phase contrast effect and angiographic K-edge imaging. Simulation results will be compared also with experimental dat

Glucose restriction induces cell death in parental but not in homeodomain-interacting protein kinase 2-depleted RKO colon cancer cells: molecular mechanisms and implications for tumor therapy.

Tumor cell tolerance to nutrient deprivation can be an important factor for tumor progression, and may depend on deregulation of both oncogenes and oncosuppressor proteins. Homeodomain-interacting protein kinase 2 (HIPK2) is an oncosuppressor that, following its activation by several cellular stress, induces cancer cell death via p53-dependent or -independent pathways. Here, we used genetically matched human RKO colon cancer cells harboring wt-HIPK2 (HIPK2(+/+)) or stable HIPK2 siRNA interference (siHIPK2) to investigate in vitro whether HIPK2 influenced cell death in glucose restriction. We found that glucose starvation induced cell death, mainly due to c-Jun NH2-terminal kinase activation, in HIPK2(+/+)cells compared with siHIPK2 cells that did not die. (1)H-nuclear magnetic resonance quantitative metabolic analyses showed a marked glycolytic activation in siHIPK2 cells. However, treatment with glycolysis inhibitor 2-deoxy-D-glucose induced cell death only in HIPK2(+/+) cells but not in siHIPK2 cells. Similarly, siGlut-1 interference did not re-establish siHIPK2 cell death under glucose restriction, whereas marked cell death was reached only after zinc supplementation, a condition known to reactivate misfolded p53 and inhibit the pseudohypoxic phenotype in this setting. Further siHIPK2 cell death was reached with zinc in combination with autophagy inhibitor. We propose that the metabolic changes acquired by cells after HIPK2 silencing may contribute to induce resistance to cell death in glucose restriction condition, and therefore be directly relevant for tumor progression. Moreover, elimination of such a tolerance might serve as a new strategy for cancer therapy

Influence of pharmacogenetic variability on the pharmacokinetics and toxicity of the aurora kinase inhibitor danusertib

Objectives Danusertib is a serine/threonine kinase inhibitor of multiple kinases, including aurora-A, B, and C. This explorative study aims to identify possible relationships between single nucleotide polymorphisms in genes coding for drug metabolizing enzymes and transporter proteins and clearance of danusertib, to clarify the interpatient variability in exposure. In addition, this study explores the relationship between target receptor polymorphisms and toxicity of danusertib. Methods For associations with clearance, 48 cancer patients treated in a phase I study were analyzed for ABCB1, ABCG2 and FMO3 polymorphisms. Association analyses between neutropenia and drug target receptors, including KDR, RET, FLT3, FLT4, AURKB and AURKA, were performed in 30 patients treated at recommended phase II dose-levels in three danusertib phase I or phase II trials. Results No relationships between danusertib clearance and drug metabolizing enzymes and transporter protein polymorphisms were found. Only, for the one patient with FMO3 18281AA polymorphism, a significantly higher clearance was noticed, compared to patients carrying at least 1 wild type allele. No effect of target receptor genotypes or haplotypes on neutropenia was observed. Conclusions As we did not find any major correlations between pharmacogenetic variability in the studied enzymes and transporters and pharmacokinetics nor toxicity, it is unlikely that danusertib is highly susceptible for pharmacogenetic variation. Therefore, no dosing alterations of danusertib are expected in the future, based on the polymorphisms studied. However, the relationship between FMO3 polymorphisms and clearance of danusertib warrants further research, as we could study only a small group of patients