51 research outputs found

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

    Update for the practicing pathologist: The International Consultation On Urologic Disease-European association of urology consultation on bladder cancer

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    The International Consultations on Urological Diseases are international consensus meetings, supported by the World Health Organization and the Union Internationale Contre le Cancer, which have occurred since 1981. Each consultation has the goal of convening experts to review data and provide evidence-based recommendations to improve practice. In 2012, the selected subject was bladder cancer, a disease which remains a major public health problem with little improvement in many years. The proceedings of the 2nd International Consultation on Bladder Cancer, which included a 'Pathology of Bladder Cancer Work Group,' have recently been published; herein, we provide a summary of developments and consensus relevant to the practicing pathologist. Although the published proceedings have tackled a comprehensive set of issues regarding the pathology of bladder cancer, this update summarizes the recommendations regarding selected issues for the practicing pathologist. These include guidelines for classification and grading of urothelial neoplasia, with particular emphasis on the approach to inverted lesions, the handling of incipient papillary lesions frequently seen during surveillance of bladder cancer patients, descriptions of newer variants, and terminology for urine cytology reporting

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    El cultivo de garbanzo (Cicer arietinum L.) en Argentina

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    El Programa Transferencia de Resultados de Investigación y Comunicación Pública de la Ciencia (PROTRI), de la Secretaría de Ciencia y Tecnología del Gobierno de la Provincia de Córdoba, financió la realización del libro El cultivo de garbanzo en Argentina con el objeto de promover la transferencia de resultados, experiencias o saberes entre las áreas del sector social y productivo para una mejor calidad de vida. Para la ejecución de esta obra han sido convocados técnicos e investigadores de las Ciencias Agropecuarias, Biológicas y Económicas, quienes en una forma clara y sencilla, aunque no menos consistente, ponen a disposición del lector sus experiencias adquiridas a lo largo de varios años de trabajo. El desarrollo de los diferentes temas se realiza a través de dieciséis Capítulos que abarcan desde la domesticación de Cicer y su llegada a la Argentina (Capítulo 1), pasando por el estudio morfológico de las diferentes partes de la planta en relación a los cultivares locales (Capítulo 2), además del manejo del suelo y sus nutrientes, en cuanto a requerimientos edáficos en los sistemas productivos (Capítulo 3). También se contempla el análisis de la influencia de los diversos factores ambientales para la determinación de zonas productivas (Capítulo 4). En el Capítulo 5 se hace referencia a la ecofisiología del cultivo, sus requerimientos en las diferentes etapas fenológicas, y cuándo y cómo se expresan en los cultivares. Un tema de indudable importancia para las leguminosas en general, y para el garbanzo en particular, es la simbiosis con las bacterias fijadoras de nitrógeno y su influencia en la productividad, el cual se desarrolla en el Capítulo 6. La mejora genética en el país es abordada en el Capítulo 7, donde se exponen sus inicios, desarrollo, disponibilidad de recursos, bondades y potencial del germoplasma disponible. A lo largo del ciclo biológico de la planta, el cultivo es visitado por insectos e infectado por hongos. Identificarlos y conocer sus ciclos biológicos y comportamientos es un aspecto importante para seleccionar las medidas de manejo y control más adecuadas (Capítulos 8 y 9). Quizás pocos sepan que el volumen de semilla genética de un cultivar, alcanza sólo unos pocos gramos (alrededor de 20). Para llevar este pequeño volumen a toneladas, se requiere del trabajo y tesón de investigadores, fitomejoradores y productores. Resultado de ese esfuerzo es la difusión de los seis cultivares obtenidos en el país, y se sigue trabajando para lograr nuevos materiales que se adapten a las diversas áreas y sistemas de producción (Capítulo 10). El desarrollo de los diferentes cultivares, que dan lugar a diversas arquitecturas de plantas, sumado a la adopción de diversos sistemas de producción, hace que el tema de la mecanización ocupe un lugar importante. Maquinas pequeñas y grandes intervienen en las etapas de siembra y de cosecha tratando de lograr la mayor eficiencia posible y un producto de calidad (Capítulo 11). Un cuello de botella para la expansión del cultivo es su comercialización, tanto para consumo interno como externo. En el Capítulo 12 se analizan los diferentes mercados y la necesidad de lograr un producto rentable de alta calidad, para mercados muy diversos. En el Capítulo 13 se hace un recorrido por las diferentes Provincias que actualmente producen garbanzo. Sus autores comentan como se incorporó el cultivo a los sistemas productivos de la región, sobre posibilidades y limitaciones, manejos y potencial de rendimiento, entre otros aportes. Los Capítulos 14 y 15 presentan dos temas de relevancia actual: la composición química del grano y las posibilidades de brindar valor agregado a éste, aspectos reforzados en la última década por el auge de las tendencias que promueven un nuevo estilo de vida y una alimentación sana, con alimentos naturales, bajos en grasa y con un buen balance nutricional. En el último Capítulo (16) se presentan experiencias de investigación en las que se utilizó al garbanzo como materia prima o como sustrato para diversas experimentaciones. La interacción docente-investigador-alumno permitió que vieran la luz diversos trabajos que, además de la formación de recursos humanos, brindan una información útil y novedosa al incursionar en temas tales como manejo de fechas de siembra, riego, alimento para pollos, cerdos y abejas. Estimado lector, tiene en sus manos un libro que es una invitación a un viaje con dieciséis estaciones. En cada una de ellas encontrará información sobre el cultivo del garbanzo en la Argentina. Estos datos fueron obtenidos por docentes, investigadores, productores, estudiantes que trabajaron y siguen trabajando para aportar al conocimiento del cultivo en nuestro país, bajo la realidad local y el contexto regional, ya que la mayoría de los trabajos y publicaciones son de origen extranjero y la aplicación de muchas de las tecnologías de manejo requieren una correcta adaptación y validación. Esperamos que este libro, además de serle útil, pueda ser disfrutado, sintiendo la pasión y el entusiasmo de cada uno de los autores por brindar y compartir sus conocimientos y logros

    Clinical outcomes meta-analysis: measuring subendocardial perfusion and efficacy of transmyocardial laser revascularization with nuclear imaging

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    Abstract Introduction Randomized and nonrandomized clinical trials have tried to assess whether or not TMR patients experience an increase in myocardial perfusion. However there have been inconsistencies reported in the literature due to the use of different nuclear imaging modalities to test this metric. The primary purpose of this meta-analysis was to determine whether SPECT, MUGA and PET scans demonstrate changes in myocardial perfusion between lased and non-lased subjects and whether laser type affects myocardial perfusion. The secondary purpose was to examine the overall effect of laser therapy on clinical outcomes including survival, hospital re-admission and angina reduction. Methods Sixteen studies were included in the primary endpoint analysis after excluding all other non-imaging TMR papers. Standardized mean difference was used as the effect size for all quantitative outcomes and log odds ratio was used as the effect size for all binary outcomes. Results Statistically significant improvements in myocardial perfusion were observed between control and treatment groups in myocardial perfusion at 6-month follow up using PET imaging with a porcine model. However non-significant differences were observed in patients at 3 and 12 months using SPECT, PET or MUGA scans. Both CO2 and Ho:YAG laser systems demonstrated an increase in myocardial perfusion however this effect was not statistically significant. In addition both laser types displayed statistically significant decreases in patient angina at 3, 6 and 12 months but non-significant increases in survival rates and decreases in hospital re-admissions. Conclusion In order to properly assess myocardial perfusion in TMR subjects, subendocardial perfusion needs to be analyzed via nuclear imaging. PET scans can provide this level of sensitivity and should be utilized in future studies to monitor and detect perfusion changes in lased and non-lased subjects

    Segmentation of the right ventricle in four chamber cine cardiac MR images using polar dynamic programming

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    The four chamber plane is currently underutilized in the right ventricular segmentation community. Four chamber information can be useful to determine ventricular short axis stacks and provide a rough estimate of the right ventricle in short axis stacks. In this study, we develop and test a semi-automated technique for segmenting the right ventricle in four chamber cine cardiac magnetic resonance images. The three techniques that use minimum cost path algorithms were used. The algorithms are: Dijkstra's shortest path algorithm (Dijkstra), an A* algorithm that uses length, curvature and torsion into an active contour model (ALCT), and a variation of polar dynamic programming (PDP). The techniques are evaluated against the expert traces using 175 cardiac images from 7 patients. The evaluation first looks at mutual overlap metrics and then focuses on clinical measures such as fractional area change (FAC). The mean mutual overlap between the physician's traces ranged from 0.85 to 0.88. Using as reference physician l's landmarks and traces (i.e., comparing the traces from physician 1 to the semi-automated segmentation using physician l's landmarks), the PDP algorithm has a mean mutual overlap of 0.8970 compared to 0.8912 for ALCT and 0.8879 for Dijkstra. The mean mutual overlap between the BP regions generated by physician 1 and physician 2 landmarks are 0.9674, 0.9605 and 0.9531 for PDP, ALCT and Dijkstra, respectively. The FAC correlation coefficient between the physician's traces ranged from 0.73 to 0.93. (C) 2017 Elsevier Ltd. All rights reserved.National Institute of Health (NIH) [T32-HL007955, HL085385]12 month embargo; published online: 18 August 2017This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Etiologies of bilateral pleural effusions

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    SummaryBackgroundTo evaluate the safety, etiology and outcomes of patients undergoing bilateral thoracentesis.MethodsThis is a prospective cohort study of 100 consecutive patients who underwent bilateral thoracenteses in an academic medical center from July 2009 through November 2010. Pleural fluid characteristics and etiologies of the effusions were assessed. Mean differences in levels of fluid characteristics between right and left lungs were tested. Associations between fluid characteristics and occurrence of bilateral malignant effusions were evaluated. The rate of pneumothorax and other complications subsequent to bilateral thoracentesis was determined.ResultsExudates were more common than transudates, and most effusions had multiple etiologies, with 83% having two or more etiologies. Bilateral malignant effusions occurred in 19 patients, were the most common single etiology of exudative effusions, and were associated with higher levels of protein and LDH in the pleural fluid. Among 200 thoracenteses performed with a bilateral procedure, seven resulted in pneumothoraces, three of which required chest tube drainage and four were ex vacuo.ConclusionsMore often than not, there are multiple etiologies that contribute to pleural fluid formation, and of the combinations of etiologies observed congestive heart failure was the most frequent contributor. Exudative effusions are more common than transudates when bilateral effusions are present. Malignancy is a common etiology of exudative effusions. This study suggests that the overall complication rate following bilateral thoracentesis is low and the rate of pneumothorax subsequent to bilateral thoracentesis is comparable to unilateral thoracentesis
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