Thoracopagus Conjoined Twins: A Case Report

Objective. Conjoined twin is a rarely seen congenital anomaly together with severe mortality and morbidity. The more common types of conjoined twins include the thoracopagus type, where the fusion is anterior, at the chest, and involves the heart. We are reporting one case of conjoined thoracopagus twins diagnosed by ultrasonography at 11 weeks. Case Report. In a multigravid pregnant woman who has been admitted to our clinic with a diagnosis of conjoined twins, thoracopagus, by ultrasonography at an 11-week gestation, termination of the pregnancy was performed. Conclusion. Making an early diagnosis with ultrasonographic examination gives the parents a chance to elect pregnancy termination

Características productivas y de gestión de fincas lecheras en Boyacá

Objetivo. Caracterizar las fincas productoras de leche y las prácticas administrativas, técnicas y de manejo en Boyacá. Materiales y métodos. Estudio epidemiológico descriptivo, a través de encuestas y registros rutinarios de la finca. Las variables se agruparon en categorías ambientales, de infraestructura, producción y administrativas. Se utilizaron el χ2 de Pearson y ANOVA para diferencia entre medias. Resultados. La temperatura ambiental promedio fue de 13.5 (± 2.18) ºC, la altura promedio de 2.630 (± 205,5) m.s.n.m, precipitación promedio anual de 49.81 (± 5,35)mm; la extensión de las fincas osciló entre 9 y 89 ha, con una media de 43.35 ha, la asistencia técnica se tuvo en el 95% de las fincas, un 75% en salud animal y un 25% en reproducción animal. La producción promedio de leche fue de 16.5 litros/vaca/día, la administración de las fincas es realizada principalmente por mayordomos. El 90% de los propietarios tienen estudios universitarios relacionados con actividades diferentes al sector agropecuario. Conclusiones. Las fincas son pequeñas comparadas con otras regiones lecheras nacionales y mundiales, la media de producción láctea es mayor que en otras regiones, hay baja gestión administrativa y se considera actividad anexa a los ingresos de los propietarios. Se hace necesario implementar estrategias de capacitación o cursos de manejo, prevención y control de enfermedades a mayordomos y operarios, cursos de gestión de empresas agropecuarias para mejorar sus renglones productivos

Quantifying the Energetics and Length Scales of Carbon Segregation to Fe Symmetric Tilt Grain Boundaries Using Atomistic Simulations

Segregation of impurities to grain boundaries plays an important role in both the stability and macroscopic behavior of polycrystalline materials. The research objective in this work is to better characterize the energetics and length scales involved with the process of solute and impurity segregation to grain boundaries. Molecular dynamics simulations are used to calculate the segregation energies for carbon within multiple grain boundary sites over a database of 125 symmetric tilt grain boundaries in Fe. The simulation results show that the majority of atomic sites near the grain boundary have segregation energies lower than in the bulk. Moreover, depending on the boundary, the segregation energies approach the bulk value approximately 5-12 \AA\ away from the center of the grain boundary, providing an energetic length scale for carbon segregation. A subsequent data reduction and statistical representation of this dataset provides critical information such as about the mean segregation energy and the associated energy distributions for carbon atoms as a function of distance from the grain boundary, which quantitatively informs higher scale models with energetics and length scales necessary for capturing the segregation behavior of impurities in Fe. The significance of this research is the development of a methodology capable of ascertaining segregation energies over a wide range of grain boundary character (typical of that observed in polycrystalline materials), which herein has been applied to carbon segregation in a specific class of grain boundaries in iron

Ab-initio study of several static and dynamic properties of liquid palladium and platinum

We report a study on several static and dynamic properties of liquid Pd and Pt metals at thermodynamic conditions near their respective triple points. The calculations have been carried out by an ab initio molecular dynamics simulation technique. Results are reported for several static structural magnitudes which are compared with the available X-ray diffraction. As for the dynamic properties, results have been obtained for both single and collective dynamical magnitudes as well as for some transport coeffcients which are compared with the corresponding experimental data

Robust production of purified H-2 in a stable, self-regulating, and continuously operating solar fuel generator

The development of practical solar-driven electrochemical fuel generators requires the integration of light absorbing and electrochemical components into an architecture that must also provide easy separation of the product fuels. Unfortunately, many of these components are not stable under the extreme pH conditions necessary to facilitate ionic transport between redox reaction sites. By using a controlled recirculating stream across reaction sites, this work demonstrates a stable, self-regulating and continuous purified solar-hydrogen generation from near neutral pH electrolytes that yield continuous nearly pure H-2 streams with solar-fuel efficiencies above 6.2%

Time Dependent Surface Corrosion Analysis and Modelling of Automotive Steel Under a Simplistic Model of Variations in Environmental Parameters

This research presents time-dependent corrosion analysis of automotive steel utilised in a large military vehicle in real operating environment, followed by simulated environmental tests and simplistic surface corrosion modelling. Time-dependent surface corrosion accumulated on this specific component was observed to be approximately 250 µm thick, with the identification of surface contaminants such as chlorine and sulphur. Simulated environmental tests considering temperature and relative humidity variations were performed to evaluate quantitative corrosion damage to the structure of the vehicle. The relationship of various temperatures and relative humidity with respect to time, within the context of corrosion initiation and propagation, has been presented. A mathematical model to incorporate corrosion accumulation on the surfaces derived from the simulated environmental tests is presented

A questão ambiental na origem do problema agrário brasileiro e o caso da região Sul.

A especificidade do processo de apropriação privada de terras públicas no Brasil, após 1850, é o ponto de origem dos problemas ambientais atuais no espaço rural, isso porque foi desse período em diante que a ausência de limites ambientais se tornou a regra principal da aliança entre a concentração fundiária e o progresso técnico aplicado à agricultura, comprometendo dramaticamente outras formas de acesso, bem como o uso produtivo ou não produtivo das terras e seus recursos naturais. O estudo de caso realizado na região sudoeste do Paraná, no Sul do Brasil, no entanto, demonstra que, apesar de uma estrutura agrária mais democrática, a regra de ausência de limites ambientais também é reiterada. Naquela região, o impulso básico à degradação ambiental deve-se ao fato de as estratégias de reprodução da agricultura familiar estarem estreitamente associadas aos imperativos do mercado exportador de grãos

The pathogen recognition sensor, NOD2, is variably expressed in patients with pulmonary tuberculosis

Background: NOD2, an intracellular pathogen recognition sensor, modulates innate defences to muropeptides derived from various bacterial species, including Mycobacterium tuberculosis (MTB). Experimentally, NOD2 attenuates two key putative mycobactericidal mechanisms. TNF-alpha synthesis is markedly reduced in MTB-antigen stimulated-mononuclear cells expressing mutant NOD2 proteins. NOD2 agonists also induce resistance to apoptosis, and may thus facilitate the survival of MTB in infected macrophages. To further define a role for NOD2 in disease pathogenesis, we analysed NOD2 transcriptional responses in pulmonary leucocytes and mononuclear cells harvested from patients with pulmonary tuberculosis (PTB).Methods: We analysed NOD2 mRNA expression by real-time polymerase chain-reaction in alveolar lavage cells obtained from 15 patients with pulmonary tuberculosis and their matched controls. We compared NOD2 transcriptional responses, in peripheral leucocytes, before and after anti-tuberculous treatment in 10 patients. In vitro, we measured NOD2 mRNA levels in MTB-antigen stimulated-mononuclear cells.Results: No significant differences in NOD2 transcriptional responses were detected in patients and controls. In some patients, however, NOD2 expression was markedly increased and correlated with toll-like-receptor 2 and 4 expression. In whole blood, NOD2 mRNA levels increased significantly after completion of anti-tuberculosis treatment. NOD2 expression levels did not change significantly in mononuclear cells stimulated with mycobacterial antigens in vitro.Conclusion: There are no characteristic NOD2 transcriptional responses in PTB. Nonetheless, the increased levels of NOD2 expression in some patients with severe tuberculosis, and the increases in expression levels within peripheral leucocytes following treatment merit further studies in selected patient and control populations

Cross-sectional validation of the Aging Perceptions Questionnaire: a multidimensional instrument for assessing self-perceptions of aging

<p>Abstract</p> <p>Background</p> <p>Self-perceptions of aging have been implicated as independent predictors of functional disability and mortality in older adults. In spite of this, research on self-perceptions of aging is limited. One reason for this is the absence of adequate measures. Specifically, there is a need to develop a measure that is theoretically-derived, has good psychometric properties, and is multidimensional in nature. The present research seeks to address this need by adopting the Self-Regulation Model as a framework and using it to develop a comprehensive, multi-dimensional instrument for assessing self-perceptions of aging. This study describes the validation of this newly-developed instrument, the Aging Perceptions Questionnaire (APQ).</p> <p>Methods</p> <p>Participants were 2,033 randomly selected community-dwelling older (+65 yrs) Irish adults who completed the APQ alongside measures of physical and psychological health. The APQ assesses self-perceptions of aging along eight distinct domains or subscales; seven of these examine views about own aging, these are: timeline chronic, timeline cyclical, consequences positive, consequences negative, control positive, control negative, and emotional representations; the eighth domain is the identity domain and this examines the experience of health-related changes.</p> <p>Results</p> <p>Mokken scale analysis showed that the majority of items within the views about aging subscales were strongly scalable. Confirmatory factor analysis also indicated that the model provided a good fit for the data. Overall, subscales had good internal reliabilities. Hierarchical linear regression was conducted to investigate the independent contribution of APQ subscales to physical and psychological health and in doing so determine the construct validity of the APQ. Results showed that self-perceptions of aging were independently related to physical and psychological health. Mediation testing also supported a role for self-perceptions of aging as partial mediators in the relationship between indices of physical functioning and physical and psychological health outcomes.</p> <p>Conclusion</p> <p>Findings support the complex and multifaceted nature of the aging experience. The good internal reliability and construct validity of the subscales suggests that the APQ is a promising instrument that can enable a theoretically informed, multidimensional assessment of self-perceptions of aging. The potential role of self-perceptions of aging in facilitating physical and psychological health in later life is also highlighted.</p