The measurement of Pitot pressure in high enthalpy expansion tubes

Expansion tubes operating at total flow enthalpies of 100 MJ kg(-1) or more have characteristical test times of 30-50 mus. Under these conditions, the response time of the Pitot pressure measuring device is critical when performing flow calibration studies. The conventional technique of using a commercial pressure transducer protected by shielding has not always proven to be effective, due to the relatively large (and variable) response time caused by the shielding. A device called the stress wave bar gauge has been designed and calibrated and shown to be an effective way to measure the Pitot pressure with a response time of only 2-3 mus.

Detection of Optimal Models in Parameter Space with Support Vector Machines

The paper proposes an approach aimed at detecting optimal model parameter combinations to achieve the most representative description of uncertainty in the model performance. A classification problem is posed to find the regions of good fitting models according to the values of a cost function. Support Vector Machine (SVM) classification in the parameter space is applied to decide if a forward model simulation is to be computed for a particular generated model. SVM is particularly designed to tackle classification problems in high-dimensional space in a non-parametric and non-linear way. SVM decision boundaries determine the regions that are subject to the largest uncertainty in the cost function classification, and, therefore, provide guidelines for further iterative exploration of the model space. The proposed approach is illustrated by a synthetic example of fluid flow through porous media, which features highly variable response due to the parameter values' combination.

Modelling bird species richness with neural networks for forest landscape management in NE Spain

Para preservar la biodiversidad de los ecosistemas forestales de la Europa mediterránea en escenarios actuales y futuros de cambio global mediante una gestión forestal sostenible es necesario determinar cómo influye el medio ambiente y las propias características de los bosques sobre la biodiversidad que éstos albergan. Con este propósito, se analizó la influencia de diferentes factores ambientales y de estructura y composición del bosque sobre la riqueza de aves forestales a escala 1 × 1 km en Cataluña (NE de España). Se construyeron modelos univariantes y multivariantes de redes neuronales para respectivamente explorar la respuesta individual a las variables y obtener un modelo parsimonioso (ecológicamente interpretable) y preciso. La superficie de bosque (con una fracción de cabida cubierta superior a 5%), la fracción de cabida cubierta media, la temperatura anual y la precipitación estival medias fueron los mejores predictores de la riqueza de aves forestales. La red neuronal multivariante obtenida tuvo una buena capacidad de generalización salvo en las localidades con una mayor riqueza. Además, los bosques con diferentes grados de apertura del dosel arbóreo, más maduros y más diversos en cuanto a su composición de especies arbóreas se asociaron de forma positiva con una mayor riqueza de aves forestales. Finalmente, se proporcionan directrices de gestión para la planificación forestal que permitan promover la diversidad ornítica en esta región de la Europa mediterránea.

Efeito da aplicação de nitrato na redução biogênica de sulfeto sob diferentes concentrações iniciais de bactérias redutoras de nitrato e sulfato

The effect of sodium nitrate application in the reduction of biogenic sulphide was evaluated through a 2k complete factorial design, using as variable response the production of sulfide at intervals of incubation of 7, 14 and 28 days. The most effective condition for reducing the sulphide production (final concentrations from 0.4 to 1.6 mg S2- L-1) was obtained with an initial population of sulphate-reducing bacteria and nitrate-reducing bacteria of 10(4) MPN mL-1 and 427.5 mg L-1 nitrate. The results also suggested that the applications of nitrate to control the process of souring should follow a continuous scheme.

Corticosteroids in acute respiratory distress syndrome

Improving the course and outcome of patients with acute respiratory distress syndrome presents a challenge. By understanding the immune status of a patient, physicians can consider manipulating proinflammatory systems more rationally. In this context, corticosteroids could be a therapeutic tool in the armamentarium against acute respiratory distress syndrome. Corticosteroid therapy has been studied in three situations: prevention in high-risk patients, early treatment with high-dose, short-course therapy, and prolonged therapy in unresolving cases. There are differences between the corticosteroid trials of the past and recent trials: today, treatment starts 2-10 days after disease onset in patients that failed to improve; in the past, the corticosteroid doses employed were 5-140 times higher than those used now. Additionally, in the past treatment consisted of administering one to four doses every 6 h (methylprednisolone, 30 mg/kg) versus prolonging treatment as long as necessary in the new trials (2 mg kg-1 day-1 every 6 h). The variable response to corticosteroid treatment could be attributed to the heterogeneous biochemical and molecular mechanisms activated in response to different initial insults. Numerous factors need to be taken into account when corticosteroids are used to treat acute respiratory distress syndrome: the specificity of inhibition, the duration and degree of inhibition, and the timing of inhibition. The major continuing problem is when to administer corticosteroids and how to monitor their use. The inflammatory mechanisms are continuous and cyclic, sometimes causing deterioration or improvement of lung function. This article reviews the mechanisms of action of corticosteroids and the results of experimental and clinical studies regarding the use of corticosteroids in acute respiratory distress syndrome.

Antiproliferative effects of retinoic acid in breast cancer

Les rétinoïdes sont utilisés dans le traitement d’une variété de tumeurs malignes et lésions précancéreuses. Leurs effets dans des lignées cellulaires dérivées de tumeurs solides tel que le cancer du sein ont été étudiés extensivement. Cependant, les bénéfices dans le cancer du sein restent à date peu clairs. Ceci est probablement du à l’hétérogénéité des tumeurs mammaires et la réponse très variable aux effets antiprolifératifs de l’acide rétinoïque. Dans les lignées cellulaires cancéreuses mammaires, la réponse l’AR est fortement corrélée au niveau d’expression du récepteur aux estrogènes alpha (ERα), qui régule l’expression du gène qui encode le récepteur à l’acide rétinoïque alpha, RARA. Malgré cela, certaines lignées cellulaires ER-négatives, comme la lignée HER2-positive SK-BR-3, ont été décrites comme étant sensibles à l’AR. Dans le Chapter 2: de cette thèse, nous avons étudié les mécanismes de la signalisation ER-dépendante et ER-indépendante dans les cellules cancéreuses mammaires. Nous avons utilisé des lignées ER-négatives et ER-positives pour démontrer qu’une partie de la réponse à l’AR est indépendante de la signalisation par ER. Nous avons identifié plusieurs gènes cibles primaires de l’AR qui ont des effets similaires à l’AR quand ils sont surexprimés dans des cellules mammaires cancéreuses. Cette étude apporte une meilleure compréhension des mécanismes complexes qui mènent à l’arrêt de croissance induit par l’AR dans les cellules cancéreuses mammaires. Dans le Chapitre 3, nous avons regardé plus en détails la signalisation ER-indépendante par l’AR dans des cellules ayant une amplification des gènes HER2 et RARA et nous avons identifié une synergie entre l’AR et le Herceptin dans ces cellules. Nous proposons que les gènes FOXO jouent une rôle dans cette synergie. Les cellules SK BR 3, ayant une coamplification HER2/RARA, pourraient représenter une classe de tumeurs qui pourraient bénéficier d’un traitement avec des rétinoïdes, en augmentent la réponse au Herceptin et potentiellement en réduisant la résistance au Herceptin. En conclusion, les données présentées dans cette thèse aident à mieux comprendre les mécanismes menant à l’arrêt de croissance induit par l’AR dans les cellules cancéreuses mammaires et fournissent une application potentielle pour l’utilisation de l’AR dans le traitement du cancer du sein.

Variabilité des souches de Escherichia coli provenant de divers poulaillers au Québec

La technique d’empreinte génétique par rep-PCR, qui utilise des séquences d’ADN répétitives, a été utilisée pour mettre en évidence la présence de groupes d’Escherichia coli signatures pour divers poulaillers et d’évaluer leur évolution suite au détassement. L’amorce (GTG)5 a été utilisée pour générer des empreintes d’ADN de 522 isolats provenant de 7 poulaillers échantillonnés deux fois : juste avant et 5 jours après le détassement. Les empreintes d’ADN ont été analysées selon l’algorithme de correspondance de bandes de Jaccard. Les analyses de Jackknife des coefficients de similitude ont révélé qu’entre 73% et 93% des isolats ont pu être correctement regroupés selon leur poulailler d’origine. Un dendrogramme construit à partir des coefficients de similitude de Jaccard a groupé les isolats dans 42 grappes avec près de la moitié dans une seule grappe. Environ 80% des isolats ont été groupés dans les 6 plus grosses grappes. Quatre de ces grappes été constituées majoritairement d’isolats provenant d’un seul site. Ces grappes pourraient être des grappes signatures qui permettraient d’identifier des poulaillers en particulier. La comparaison des nombres de grappes présentes avant et après le détassement a révélé une variabilité de l’impact du détassement sur les populations fécales d’E. coli. Pour certains sites, il y avait peu d’agrégats présents tant avant qu’après le détassement alors que pour d’autres sites c’était le contraire. Quoique plus de recherches soient nécessaires afin de valider les conclusions, nos résultats suggèrent la présence de sous-populations signatures d’E. coli pour certains poulaillers et une réponse variable à l’effet du détassement.

Studies on ocean surface layer responses to atmospheric forcing in the North Indian Ocean

The present study on upper ocean responses to atmospheric forcing (associated with cyclone passage) in North Indian Ocean revealed significant variability between AS and BoB. The analysis of cyclone frequency during 1947 to 2006 exhibited lesser frequency of cyclones in AS than that of BoB. The analysis also revealed significant reduction in cyclone frequency after the year 1976 with substantial reduction during monsoon season. The long term SST data at selected points in AS and BoB could not reveal any relation with reduction in cyclone frequency. However the SLP at same locations exhibited considerable increase during mid 1970’s, which could have contributed to the observed reduction in cyclone frequency after the year 1976.The response in waves during cyclone passage exhibited significant asymmetry on either side of the track in AS and BoB and the response is observed at 100’s of kilometers away from the track. The significant clockwise rotation in wave direction is observed on the right side of the track starting from near the track to far away locations, which existed for a longer duration. However, the anticlockwise rotation in wave direction is observed over a shorter distance on the left side of the track and dissipated immediately.Inertial oscillation is observed in surface current and in the mixed layer temperature associated with cyclone passage, which revealed the role of relative location(s) on either side of the track. The inertial peak closer to the local inertial period indicates maximum transfer of energy during the cyclone passage in both AS and BoB. The absence of strong inertial oscillation even with clockwise rotation in surface current and wind indicates the dominant role of duration of strong wind in generating inertial oscillation.The oceanic response associated with cyclone passage reveal the variable response(s) which depends on cyclone intensity, the proximity to track and cyclone translation speed. It is observed that resonance with wind generates higher response in surface current, wave and SST on the right side of the track and it lasts for a longer duration. The maximum oceanic response is observed at a few kilometers away on right side of the track. However lesser rightward bias in the location of maximum cooling is observed for cyclones with low cyclone translation speed. The response on the left side of the track is less and is limited over a shorter distance and dissipates immediately. It is observed that the ocean response, in general, increases with intensity of cyclones. However the differential cooling produced by the same intensity cyclones in AS and in BoB indicates the dominant role of low cyclone translation speed in oceanic response.The surface cooling exhibited strikingly differential responses between AS and BoB. The TMI-SST and buoy observations exhibited significant cooling for a longer duration in AS compared to that of BoB. The spatial extent of cooling is also much higher in AS than that of BoB. The wide spread cooling associated with cyclone passage in AS indicates the dominant role of thermal structure in oceanic response in AS than that of BoB.

Respuesta clínica con el uso de beclometasona inhalada durante mínimo 4 semanas y factores ambientales, familiares y personales asociados, en pacientes con diagnóstico de asma, entre 6 y 15 años

Objetivo: el asma es una enfermedad que ha aumentado su incidencia afectando principalmente los niños, causando deterioro de la calidad de vida y su desarrollo. El tratamiento está basado en el uso de esteroides inhalados, el cual genera una respuesta variable en cada individuo. Buscamos determinar cuál es la respuesta clínica en nuestros pacientes y la asociación de ésta con 20 variables que incluyen factores ambientales, familiares o personales. Materiales y métodos: se realizó un estudio observacional de corte transversal. Se evaluaron 93 pacientes de edades entre 6 y 15 años, con diagnóstico de asma leve o moderada persistente, que reciben tratamiento con beclometasona por 4 semanas y que asisten a control en la Clínica Infantil Colsubsidio entre agosto – octubre 2009. Se analizaron los resultados mediante descripción de la población por porcentaje y obtención de OR con intervalo de confianza del 95% para evaluación de variables. Resultados: de los 93 pacientes, con una media de 8.5±2.5 años y genero más frecuente el masculino (58.1%). Diagnóstico inicial de ALP 75.3% y AMP de 24.7%. No se controlaron el 69.9% de los niños. No encontramos diferencia estadísticamente significativa entre los factores de riesgo y diferencia por géneros con la respuesta clínica. Conclusiones: los pacientes con ALP y AMP que reciben tratamiento monoterápico con Beclometasona, el 69.9% no se controlan y es importante optimizar en todos los casos el tratamiento hasta lograr su control. No hay evidencia significativa en las variables estudiadas como factores modificadores de la respuesta clínica.

Resultado postnatal de fetos con malformación adenomatoide quística pulmonar en la unidad maternofetal Clínica Colombia

Introducción La Malformación Adenomatoide Quística Pulmonar es una patología que se desarrolla durante estadíos tempranos de desarrollo embriológico y su pronóstico depende del tamaño de la lesión pulmonar. Existen muy pocos estudios que caractericen esta patología, ninguno en nuestro país. Metodología Se realizó una serie de casos para describir el resultado postnatal de los casos registrados en la Clínica Colombia entre 2005 hasta 2013. Resultados: Se incluyeron un total de 20 casos. La malformación más frecuente fue MAQ III con 45% de los casos, de localización izquierda (75%), el 65% nacieron después de la semana 35 y con un peso mayor de 2500 g. Tan solo 30 % desarrollaron hidrops asociado. Hubo una mortalidad de 35% (7 casos). Discusion La MAQ es un patología infrecuente que genera una alta morbimortalidad en la vida perinatal. Se requieren estudios con muestras más amplias para determinar los factores pronósticos para la ocurrencia de los desenlaces adversos como la necesidad de cirugía de urgencia, deterioro respiratorio o mortalidad.

Model inter-comparison between statistical and dynamic model assessments of the long-term stability of blanket peat in Great Britain (1940-2099)

We compared output from 3 dynamic process-based models (DMs: ECOSSE, MILLENNIA and the Durham Carbon Model) and 9 bioclimatic envelope models (BCEMs; including BBOG ensemble and PEATSTASH) ranging from simple threshold to semi-process-based models. Model simulations were run at 4 British peatland sites using historical climate data and climate projections under a medium (A1B) emissions scenario from the 11-RCM (regional climate model) ensemble underpinning UKCP09. The models showed that blanket peatlands are vulnerable to projected climate change; however, predictions varied between models as well as between sites. All BCEMs predicted a shift from presence to absence of a climate associated with blanket peat, where the sites with the lowest total annual precipitation were closest to the presence/absence threshold. DMs showed a more variable response. ECOSSE predicted a decline in net C sink and shift to net C source by the end of this century. The Durham Carbon Model predicted a smaller decline in the net C sink strength, but no shift to net C source. MILLENNIA predicted a slight overall increase in the net C sink. In contrast to the BCEM projections, the DMs predicted that the sites with coolest temperatures and greatest total annual precipitation showed the largest change in carbon sinks. In this model inter-comparison, the greatest variation in model output in response to climate change projections was not between the BCEMs and DMs but between the DMs themselves, because of different approaches to modelling soil organic matter pools and decomposition amongst other processes. The difference in the sign of the response has major implications for future climate feedbacks, climate policy and peatland management. Enhanced data collection, in particular monitoring peatland response to current change, would significantly improve model development and projections of future change.

Índice preditor de reserva ovariana (ORPI) para controle de estimulação ovariana individualizado

Objective: to expand the evaluation of a new ovarian response prediction index (ORPI), which was based on the AMH, AFC and age, and to verify its reability as a predictor of ovarian response to stimulation in assisted reproductive technology (ART) cycles. Methods: A total of 129 patients enrolled in the ICSI programme were included. The ORPI values were calculated by multiplying the AMH level (ng/ml) by the number of antral follicles (2-9 mm), and the result was divided by the age (years) of the patient (ORPI=(AMH × AFC)/Patient age). Results: Spearman's test revealed significant correlations (P<0.0001) between the ORPI and the number of oocytes collected and the number of follicles. Logistic regression revealed that ORPI values were significantly associated with the likelihood of collecting ≥4 oocytes (OR=45.56), ≥4 MII oocytes (OR=6.01) and ≥15 oocytes (OR=6.15; P<0.0001). Based on the ROC curves, the ORPI accurately predicted a low ovarian response (<4 oocytes retrieved; area under the curve (AUC):0.91), collection of ≥4 MII oocytes (AUC:0.85) and an excessive ovarian response (≥15 oocytes retrieved; AUC:0.89). Conclusions: The ORPI exhibited an excellent ability to predict a low ovarian response and a good ability to predict a collection of ≥ 4 MII oocytes, an excessive ovarian response. The ORPI might be used to improve the cost-benefit ratio of ovarian stimulation regimens by guiding the selection of medications and by modulating the doses and regimens according to the actual needs of the patients. © Todos os direitos reservados a SBRA - Sociedade Brasileira de Reprodução Assistida.

Utilização de técnicas do planejamento de experimentos na otimização de um processo de torneamento da superliga NIMONIC 80A

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Silício e nitrogênio em alho vernalizado com e sem limpeza de vírus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Physiological Parameters in Neonatal Lambs of the Bergamasca Breed

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)