Voxel model in BNCT treatment planning: Performance analysis and improvements

In recent years, many efforts have been made to study the performance of treatment planning systems in deriving an accurate dosimetry of the complex radiation fields involved in boron neutron capture therapy (BNCT). The computational model of the patient's anatomy is one of the main factors involved in this subject. This work presents a detailed analysis of the performance of the 1 cm based voxel reconstruction approach. First, a new and improved material assignment algorithm implemented in NCTPlan treatment planning system for BNCT is described. Based on previous works, the performances of the 1 cm based voxel methods used in the MacNCTPlan and NCTPlan treatment planning systems are compared by standard simulation tests. In addition, the NCTPlan voxel model is benchmarked against in-phantom physical dosimetry of the RA-6 reactor of Argentina. This investigation shows the 1 cm resolution to be accurate enough for all reported tests, even in the extreme cases such as a parallelepiped phantom irradiated through one of its sharp edges. This accuracy can be degraded at very shallow depths in which, to improve the estimates, the anatomy images need to be positioned in a suitable way. Rules for this positioning are presented. The skin is considered one of the organs at risk in all BNCT treatments and, in the particular case of cutaneous melanoma of extremities, limits the delivered dose to the patient. Therefore, the performance of the voxel technique is deeply analysed in these shallow regions. A theoretical analysis is carried out to assess the distortion caused by homogenization and material percentage rounding processes. Then, a new strategy for the treatment of surface voxels is proposed and tested using two different irradiation problems. For a parallelepiped phantom perpendicularly irradiated with a 5 keV neutron source, the large thermal neutron fluence deviation present at shallow depths (from 54% at 0 mm depth to 5% at 4 mm depth) is reduced to 2% on average. Reassigning fluence values in the case of this phantom in angular position produced the maximum deviation in the thermal fluence to decrease from 140% to 23% at the surface of the phantom. Thus, even for the largest deviations, obtained by intentionally placing the phantom in the most disadvantageous position with respect to the voxel grid, the reassignment shows very good performance. Since these results substantially improve the performance of the 1 cm based voxel model in surface boundary regions, the proposed strategy will be implemented in future versions of the NCTPlan code.Fil: González, Sara Josefina. Comisión Nacional de Energía Atómica; Argentina. United Automobile Insurance Company; ArgentinaFil: Carando, Daniel Germán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigaciones Matemáticas "Luis A. Santaló". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Matemáticas "Luis A. Santaló"; Argentina. Universidad de San Andrés; ArgentinaFil: Santa Cruz, Gustavo Alberto. Comisión Nacional de Energía Atómica; Argentina. United Automobile Insurance Company; ArgentinaFil: Zamenhof, Robert G.. Tufts-New England Medical Center; Estados Unido

Quality of Work Life and Mental Health in Primary Care Physicians

AbstractThe aim of this study was to find the relationship between the perception of Quality of Work Life (QWL) and the mental health of primary care physicians of a public health institution in Guadalajara, Mexico. The study was analytical and was carried out with a universe of 818 doctors from 92 health units and the probability sample of 154 people. In all of them, CVT-GOHISALO and Goldberg GHQ-28 questionnaires were applied in order to measure their perception of QWL and the risk of mental illness respectively. Both instruments were selected because of their high reliability. We measured the satisfaction of the people interviewed for each one of the seven dimensions of CVT-GOHISALO and related to the points assigned to GHQ-28 case or not to consider the case of mental illness. The percentages of dissatisfaction with the QWL were greater than 12% in all dimensions of the instrument, being the highest value of 20.5% dissatisfaction for the job satisfaction dimension. In the classification of the case or not according to the GHQ-28, 22% were considered cases and 78% non-cases. We sought correspondence of satisfaction with the QWL by dimensions and non-case of Goldberg's, as well as dissatisfaction with the QWL and Goldberg's case, finding a clear link between being satisfied and having mental health. All dimensions have a correspondence that goes from 79.7% to 82.3% between satisfaction and non-case, being in all the statistical significance value less than 0.05 For primary care physicians in the studied institution, there is a clear relationship between being satisfied with the QWL and present less risk of mental illness. It is alarming that the medical staff presents high rates of dissatisfaction with the QWL and risk of mental illness. It is necessary to provide preventive programs among health care workers in order to improve their QWL and mental health

Duración de la gestación en el ganado bovino criollo costeño con cuernos

The aim of this study was to determine the duration of pregnancy in the Creole cattle breed Costeño con Cuernos and establish whether factors such as the sex of the calf or order delivery could intervene in the duration of this period. A retrospective study was conducted in a herd of females of Center for Agricultural Research, Turipaná, Cerete, Colombia. It was considered as length of gestation, the interval between the date of effective service and date of delivery time. The period considered was between the years 1969 and 1988. The overall average length of gestation of 184 cases was 288.6 ± 5.7 days. Calf sex influenced (p <0.05) on the length of gestation, and was longer lasting when it was male, when was female (290 ± 288 ± 5.2 vs. 6.0). Cows were arranged according to the number of labor into three groups: group I (one and two deliveries), group II (three and four deliveries) and group III (5 or more deliveries). It was found that the sex of the fetus was a cause of variation in the length of gestation of cows Costeño con Cuernos (p <0.05) among the cows in groups I and II, and between group II and III.Determinar la duración de la gestación en la raza bovina criolla Costeño con Cuernos y establecer si factores tales como el sexo del ternero o el orden de partos podrían intervenir en la duración de este periodo. Se realizó un estudio retrospectivo en un hato de hembras del Centro de Investigación Agropecuaria, Turipaná, Cereté, Colombia. Se consideró como duración de la gestación, el intervalo de tiempo transcurrido entre la fecha del servicio efectivo y la fecha del parto. El periodo considerado fue entre los años de 1969 y 1988. El promedio general de la duración de la gestación de 184 casos fue de 288,6 ± 5,7 días. El sexo del ternero influyó (p<0,05) sobre la duración de la gestación, y resultó de mayor duración cuando fue macho, que cuando fue hembra (290 ± 5,2 vs. 288±6,0). Las vacas fueron ordenadas de acuerdo con el número del parto en tres grupos: grupo I (uno y dos partos), grupo II (tres y cuatro partos) y grupo III (5 o más partos). Se encontró que el sexo del feto fue una causa de variación en la duración de la gestación de las vacas Costeño con Cuernos (p<0,05) entre las vacas de los grupos I y II, así como entre las vacas de los grupos II y III

The southernmost record of a Neuryurini Hoffstetter, 1958 (Mammalia, Xenarthra, Glyptodontidae)

Fil: González Ruiz, Laureano Raúl. Universidad Nacional de La Patagonia; ArgentinaFil: Zurita, Alfredo Eduardo. Centro de Ecologia Aplicada del Litoral (CECOAL). Universidad Nacional del Nordeste; CorrientesFil: Fleagle, John G.. Stony Brook University State University of New York. Department of Anatomical Sciences. Stony Brook United States; ArgentinaFil: Scillato-Yané, Gustavo Juan. División Paleontología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Dozo, María Teresa. Laboratorio de Paleontología, Centro Nacional Patagónico CONICET, Blvd. Alte. Guillermo Browns/n, 9120 Puerto Madryn, Chubut, ArgentinaFil: Zamorano, Martín. División Paleontología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Mixed micelles and gels of a hydrophilic poloxamine (Tetronic 1307) and miltefosine: Structural characterization by small-angle neutron scattering and in vitro evaluation for the treatment of leishmaniasis

Hypothesis/background: Tetronic is a family of four-armed amphiphilic block copolymers of polyethylene oxide (PEO) and polypropylene oxide (PPO) that self-aggregate to form micelles and hydrogels. Due to their temperature and pH-responsiveness, they are emerging as smart nanomaterials in the area of drug delivery. Here we propose the use of Tetronic 1307 (T1307) as a nanocarrier of miltefosine (MF), a zwitterionic alkylphospholipid highly active against leishmaniasis, one of the most threating neglected tropical diseases. Given the amphiphilic nature of the drug, both surfactants can combine to form mixed micelles, reducing the cytotoxicity of MF by lowering its dose and improving its internalization, hence its antileishmanial effect. Experiments: The structure of the T1307 micelles, MF micelles, mixed micelles and hydrogels, formed in buffered solution (pH = 7.4) at different concentrations has been investigated in-depth by a combination of small-angle neutron scattering (SANS), dynamic light scattering (DLS), fluorescence spectroscopy and nuclear magnetic resonance methods (1D, 2D NOESY, and diffusion NMR). The cytotoxicity of the aggregates in macrophages has been assessed, as well as the antileishmanial activity in both Leishmania major promastigotes and amastigotes. Findings: T1307 and MF combine into mixed aggregates over a wide range of temperatures and compositions, forming ellipsoidal core–shell mixed micelles. The shell is highly hydrated and comprises most of the PEO blocks, while the hydrophobic core contains the PO blocks and the MF along with a fraction of EO and water molecules, depending on the molar ratio in the mixture. The combination with T1307 amplified the leishmanicidal activity of the drug against both forms of the parasite and dramatically reduced drug cytotoxicity. T1307 micelles also showed a considerable leishmanicidal activity without exhibiting macrophage toxicity. These results support the use of T1307 as a MF carrier for the treatment of human and animal leishmaniasis, in its different clinical forms

Where does the peanut smut pathogen, Thecaphora frezii, fit in the spectrum of smut diseases?

Smut fungi, such as Ustilago maydis, have been studied extensively as a model for plant-pathogenic basidiomycetes. However, little attention has been paid to smut diseases of agronomic importance that are caused by species of the genus Thecaphora, probably due to their more localized distribution. Peanut smut incited by Thecaphora frezii has been reported only in South America, and Argentina is the only country where this disease has been noted in commercial peanut production. In this work, important advances in deciphering T. frezii specific biology/pathobiology in relation to potato (T. solani), wheat (U. tritici), and barley (U. nuda) smuts are presented. We summarize the state of knowledge of fungal effectors, functionally characterized to date in U. maydis and most recently in T. thlaspeos, as well as the potential to be present in other Thecaphora species involved in dicot-host interactions like T. frezii-peanut. We also discuss applicability and limitations of currently available methods for identification of smut fungi in different situations and management strategies to reduce their impact on agri-food quality. We conclude by describing some of the challenges in elucidating T. frezii strategies that allow it to infect the host and tolerate or evade plant immune defense mechanisms, and assessing other aspects related to pest control and their implications for human health.Fil: Arias, Silvina Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina. University of Iowa; Estados UnidosFil: Mary, Verónica Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; ArgentinaFil: Velez, Pilar Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Rodriguez, María G.. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Otaiza González, Santiago Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; ArgentinaFil: Theumer, Martín Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentin

Accurate Atmospheric Parameters at Moderate Resolution Using Spectral Indices: Preliminary Application to the MARVELS Survey

Studies of Galactic chemical and dynamical evolution in the solar neighborhood depend on the availability of precise atmospheric parameters (Teff, [Fe/H] and log g) for solar-type stars. Many large-scale spectroscopic surveys operate at low to moderate spectral resolution for efficiency in observing large samples, which makes the stellar characterization difficult due to the high degree of blending of spectral features. While most surveys use spectral synthesis, in this work we employ an alternative method based on spectral indices to determine the atmospheric parameters of a sample of nearby FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving power (R~12,000). We have developed three codes to automatically normalize the observed spectra, measure the equivalent widths of the indices and, through the comparison of those with values calculated with pre-determined calibrations, derive the atmospheric parameters of the stars. The calibrations were built using a sample of 309 stars with precise stellar parameters obtained from the analysis of high-resolution FEROS spectra. A validation test of the method was conducted with a sample of 30 MARVELS targets that also have reliable atmospheric parameters from high-resolution spectroscopic analysis. Our approach was able to recover the parameters within 80 K for Teff, 0.05 dex for [Fe/H] and 0.15 dex for log g, values that are lower or equal to the typical external uncertainties found between different high-resolution analyzes. An additional test was performed with a subsample of 138 stars from the ELODIE stellar library and the literature atmospheric parameters were recovered within 125 K for Teff, 0.10 dex for [Fe/H] and 0.29 dex for log g. These results show that the spectral indices are a competitive tool to characterize stars with the intermediate resolution spectra.Comment: Accepted for publication in AJ. Abstract edited to comply with arXiv standards regarding the number of character

Innovación en el uso de planillas Excel para la enseñanza de estructuras en arquitectura

Ponencia presentada en el XXV Congreso Latinoamericano de Escuelas y Facultades de Arquitectura y Diseño. CLEFA 2014. Asunción del ParaguayEn una época donde las metodologías de enseñanza se diversifican, y la tecnología de información y la comunicación han alcanzado a ser totalmente cotidianos para las nuevas generaciones (llamadas nativas digitales), se proponen nuevos usos de los software en la instrumentación de las estructuras en Arquitectura. Los alumnos de arquitectura, tienen competencias gráficas e informáticas, habilidades para ubicarse en el espacio, facilidad para interpretar esquemas, y especial interés por las imágenes que relacionan con procesos creativos y constructivos. A partir de estas capacidades se introduce una metodología que incluye la utilización de recursos informáticos contemplando las características de los estudiantes. Se desarrollaron planillas pensadas para integrar contenidos teóricos y prácticos. En ellas se incorporan hipertextos y pestañas, atendiendo a la lógica de multipantallas, propuesta por internet, en las que se encuentra información reglamentaria textual y gráfica. Estas planillas fueron diseñadas para facilitar la resolución de cálculos complejos de forma tal que el alumno se enfoque en el diseño, el cual además, debe ser coherente y compatible con la materialidad. Este recurso permite, además, verificar rápidamente distintas alternativas de resolución del proyecto, incorporando herramientas acordes a las habilidades propias del estudiante de arquitectura, tales como el uso de AutoCAD para introducir datos, la lectura a través de gráficos y variables de selección para verificar la viabilidad de las propuestas. El uso de técnicas informáticas con un sentido didáctico introduce al alumno en el uso de software específicos, con condicionantes definidas que permiten sortear la tarea procedimental y centralizarse en el manejo de las variables que inciden en los parámetros proyectuales, en busca de una retroalimentación que le permita tomar decisiones de diseño. En otras palabras, como dice Alicia de Camilloni “se busca alentar” el desafío de usar, con sabiduría práctica, el instrumental a disposición, para la mejora efectiva de las prácticas de enseñanza.Fil: Elicabe, Alberto. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Simonetti, Isolda. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Mansilla, María Julieta. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: González, Gustavo G. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Ghezan, Nahuel. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Altamirano, Horacio. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaIngeniería Arquitectónic