2,615 research outputs found
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Prediction of Recovery From Severe Hemorrhagic Shock Using Logistic Regression.
This paper implements logistic regression models (LRMs) and feature selection for creating a predictive model for recovery form hemorrhagic shock (HS) with resuscitation using blood in the multiple experimental rat animal protocols. A total of 61 animals were studied across multiple HS experiments, which encompassed two different HS protocols and two resuscitation protocols using blood stored for short periods using five different techniques. Twenty-seven different systemic hemodynamics, cardiac function, and blood gas parameters were measured in each experiment, of which feature selection deemed only 25% of the them as relevant. The reduced feature set was used to train a final logistic regression model. A final test set accuracy is 84% compared to 74% for a baseline classifier using only MAP and HR measurements. Receiver operating characteristics (ROC) curve analysis and Cohens kappa statistics were also used as measures of performance, with the final reduced model outperforming the model, including all parameters. Our results suggest that LRMs trained with a combination of systemic hemodynamics, cardiac function, and blood gas parameters measured at multiple timepoints during HS can successfully classify HS recovery groups. Our results show the predictive ability of traditional and novel hemodynamic and cardiac function features and their combinations, many of which had not previously been taken into consideration, for monitoring HS. Furthermore, we have devised an effective methodology for feature selection and shown ways in which the performance of such predictive models should be assessed in future studies
Agile Ways of Working: A Team Maturity Perspective
With the agile approach to managing software development projects comes an
increased dependability on well functioning teams, since many of the practices
are built on teamwork. The objective of this study was to investigate if, and
how, team development from a group psychological perspective is related to some
work practices of agile teams. Data were collected from 34 agile teams (200
individuals) from six software development organizations and one university in
both Brazil and Sweden using the Group Development Questionnaire (Scale IV) and
the Perceptive Agile Measurement (PAM). The result indicates a strong
correlation between levels of group maturity and the two agile practices
\emph{iterative development} and \emph{retrospectives}. We, therefore, conclude
that agile teams at different group development stages adopt parts of team
agility differently, thus confirming previous studies but with more data and by
investigating concrete and applied agile practices. We thereby add evidence to
the hypothesis that an agile implementation and management of agile projects
need to be adapted to the group maturity levels of the agile teams
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Itaconate modulates tricarboxylic acid and redox metabolism to mitigate reperfusion injury.
ObjectivesCerebral ischemia/reperfusion (IR) drives oxidative stress and injurious metabolic processes that lead to redox imbalance, inflammation, and tissue damage. However, the key mediators of reperfusion injury remain unclear, and therefore, there is considerable interest in therapeutically targeting metabolism and the cellular response to oxidative stress.MethodsThe objective of this study was to investigate the molecular, metabolic, and physiological impact of itaconate treatment to mitigate reperfusion injuries in in vitro and in vivo model systems. We conducted metabolic flux and bioenergetic studies in response to exogenous itaconate treatment in cultures of primary rat cortical neurons and astrocytes. In addition, we administered itaconate to mouse models of cerebral reperfusion injury with ischemia or traumatic brain injury followed by hemorrhagic shock resuscitation. We quantitatively characterized the metabolite levels, neurological behavior, markers of redox stress, leukocyte adhesion, arterial blood flow, and arteriolar diameter in the brains of the treated/untreated mice.ResultsWe demonstrate that the "immunometabolite" itaconate slowed tricarboxylic acid (TCA) cycle metabolism and buffered redox imbalance via succinate dehydrogenase (SDH) inhibition and induction of anti-oxidative stress response in primary cultures of astrocytes and neurons. The addition of itaconate to reperfusion fluids after mouse cerebral IR injury increased glutathione levels and reduced reactive oxygen/nitrogen species (ROS/RNS) to improve neurological function. Plasma organic acids increased post-reperfusion injury, while administration of itaconate normalized these metabolites. In mouse cranial window models, itaconate significantly improved hemodynamics while reducing leukocyte adhesion. Further, itaconate supplementation increased survival in mice experiencing traumatic brain injury (TBI) and hemorrhagic shock.ConclusionsWe hypothesize that itaconate transiently inhibits SDH to gradually "awaken" mitochondrial function upon reperfusion that minimizes ROS and tissue damage. Collectively, our data indicate that itaconate acts as a mitochondrial regulator that controls redox metabolism to improve physiological outcomes associated with IR injury
Determination of Number of Instars of Rhyssomatus subtilis (Coleoptera: Curculionidae) Based on Head Capsule Widths
Rhyssomatus subtilis Fiedler (Coleoptera: Curculionidae) es una importante plaga del cultivo de soja en el Noroeste Argentino. Existen pocos estudios acerca de parámetros especÃficos del ciclo de vida y de comportamiento ecológico. El objetivo de este estudio fue determinar el número de instares larvales de R. subtilis. En total, 1018 larvas fueron colectadas del cultivo de soja durante 2011 y 2013. Se midió el ancho de la cápsula cefálica de cada larva. Para el análisis de los datos se utilizó el programa Hcap y la regla de Dyar. El programa Hcap mostró cuatro picos distintos en la distribución de frecuencias de la anchura de la cápsula cefálica. Estos resultados concuerdan con la regla de Dyar que muestra un perfecto crecimiento geométricos de las larvas para cada instar representada por la lÃnea de regresión. El excelente ajuste del modelo lineal, indica que no hay instares solapados. Esta investigación identificó cuatro instares larvales para R. subtilis.Rhyssomatus subtilis Fiedler (Coleoptera: Curculionidae) is an important pest of the soybean crop in northwestern Argentina. Few studies have been made on specific parameters of its life history and ecology. The aim of this study was to determine the number of larval stages of R. subtilis. One thousand and eighteen larvae were collected from soybean plants during 2 yr (2011 and 2013), and head capsule width of each larva was measured. For analysis of data, the Hcap program and Dyar's rule were used. The Hcap program showed 4 different peaks in the frequency distribution of the head capsule widths. This result also agreed with Dyar's rule that revealed a perfect geometric larval growth pattern for each instar by regression analysis. The excellent fit to a linear model, indicates that no instar was overlooked. This research identified 4 instars for R. subtilis.Fil: Cazado, Lucas Emiliano. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Instituto de TecnologÃa Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres"(p). Instituto de TecnologÃa Agroindustrial del Noroeste Argentino; ArgentinaFil: Van Nieuwenhove, Guido Alejandro. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: O'brien, C. W.. No especifica;Fil: Gastaminza, Gerardo Alfredo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Murúa, MarÃa Gabriela. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Instituto de TecnologÃa Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres"(p). Instituto de TecnologÃa Agroindustrial del Noroeste Argentino; Argentin
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Numerical Model for the Determination of Erythrocyte Mechanical Properties and Wall Shear Stress in vivo From Intravital Microscopy.
The mechanical properties and deformability of Red Blood Cells (RBCs) are important determinants of blood rheology and microvascular hemodynamics. The objective of this study is to quantify the mechanical properties and wall shear stress experienced by the RBC membrane during capillary plug flow in vivo utilizing high speed video recording from intravital microscopy, biomechanical modeling, and computational methods. Capillaries were imaged in the rat cremaster muscle pre- and post-RBC transfusion of stored RBCs for 2-weeks. RBC membrane contours were extracted utilizing image processing and parametrized. RBC parameterizations were used to determine updated deformation gradient and Lagrangian Green strain tensors for each point along the parametrization and for each frame during plug flow. The updated Lagrangian Green strain and Displacement Gradient tensors were numerically fit to the Navier-Lame equations along the parameterized boundary to determined Lame's constants. Mechanical properties and wall shear stress were determined before and transfusion, were grouped in three populations of erythrocytes: native cells (NC) or circulating cells before transfusion, and two distinct population of cells after transfusion with stored cells (SC1 and SC2). The distinction, between the heterogeneous populations of cells present after the transfusion, SC1 and SC2, was obtained through principle component analysis (PCA) of the mechanical properties along the membrane. Cells with the first two principle components within 3 standard deviations of the mean, were labeled as SC1, and those with the first two principle components greater than 3 standard deviations from the mean were labeled as SC2. The calculated shear modulus average was 1.1±0.2, 0.90±0.15, and 12 ± 8 MPa for NC, SC1, and SC2, respectively. The calculated young's modulus average was 3.3±0.6, 2.6±0.4, and 32±20 MPa for NC, SC1, and SC2, respectively. o our knowledge, the methods presented here are the first estimation of the erythrocyte mechanical properties and shear stress in vivo during capillary plug flow. In summary, the methods introduced in this study may provide a new avenue of investigation of erythrocyte mechanics in the context of hematologic conditions that adversely affect erythrocyte mechanical properties
Determinación de la concentración de flúor en muestras biológicas
Descripción de las diferentes técnicas para la medición de flúor en muestras de diversos orÃgenes. Tecnicas colorimétricas, potenciométricas, cromatográficas. Reseña sobre los efectos biológicos y tóxicos del flúor.Laboratorio de BiologÃa Ósea. Facultad de Ciencias MédicasFil: Rigalli, Alfredo. Universidad Nacional de Rosario. Facultad de Ciencias Médicas. Laboratorio de BiologÃa Ósea y Metabolismo Mineral. CONICET. Rosario; Argentina.Fil: Brun, Lucas. . Universidad Nacional de Rosario. Facultad de Ciencias Médicas. Laboratorio de BiologÃa Ósea y Metabolismo Mineral. Rosario; Argentina.Fil: Di Loreto, Verónica. Universidad Nacional de Rosario. Facultad de Ciencias Médicas. Laboratorio de BiologÃa Ósea y Metabolismo Mineral. Rosario; Argentina.Fil: Pera, Laura. Universidad Nacional de Rosario. Facultad de Ciencias Médicas. Laboratorio de BiologÃa Ósea y Metabolismo Mineral. Rosario; Argentina
Luminal calcium concentration controls intestinal calcium absorption by modification of intestinal alkaline phosphatase activity
Intestinal alkaline phosphatase (IAP) is a brush-border phosphomonoesterase. Its location suggests an involvement in the uptake of nutrients, but its role has not yet been defined. IAP expression parallels that of other proteins involved in Ca absorption under vitamin D stimulation. Experiments carried out in vitro with purified IAP have demonstrated an interaction between Ca and IAP. The gut is prepared to face different levels of Ca intake over time, but high Ca intake in a situation of a low-Ca diet over time would cause excessive entry of Ca into the enterocytes. The presence of a mechanism to block Ca entry and to avoid possible adverse effects is thus predictable. Thus, in the present study, Sprague-Dawley rats were fed with different amounts of Ca in the diet (0•2, 1 and 2 g%), and the percentage of Ca absorption (%Ca) in the presence and absence of l-phenylalanine (Phe) was calculated. The presence of Phe caused a significant increase in %Ca (52•3 (SEM 6•5)% in the presence of Phe v. 31•1 (SEM 8•9)% in the absence of Phe, regardless of the amount of Ca intake; paired t test, P = 0•02). When data were analysed with respect to Ca intake, a significant difference was found only in the group with low Ca intake (paired t test, P = 0•03). Additionally, IAP activity increased significantly (ANOVA, P < 0•05) as Ca concentrations increased in the duodenal lumen. The present study provides in vivo evidence that luminal Ca concentration increases the activity of IAP and simultaneously decreases %Ca, acting as a minute-to-minute regulatory mechanism of Ca entry.Fil: Brun, Lucas Ricardo MartÃn. Universidad Nacional de Rosario. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Brance, MarÃa Lorena. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Rigalli, Alfredo. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
¿Cuarta Guardia?: Un acercamiento a los recursos técnicos del tango canción del siglo XXI a través del abordaje de tres casos
A través del estudio de una serie de casos referidos al género se intenta contribuir a la producción de material bibliográfico especÃfico acerca de los recursos técnico-musicales usuales en el tango canción del siglo XXI. Se buscará abrir el debate sobre los ejes continuidad-ruptura en las producciones actuales, asà como también comenzar a reflexionar acerca de la delimitación de los contornos estéticos y conceptuales de una corriente contemporánea y en constante movimiento. La convivencia de una multiplicidad de sentidos al interior de una misma práctica artÃstica tiene como resultado una realidad conformada por destellos fugaces, escurridizos y difÃciles de asir: más aún cuando esta práctica recién ha comenzado a mirar dentro de sà y a generar un espacio introspectivo de reflexión. Es a través de estas miradas que se buscará ir descubriendo las estructuras inherentes a la entretejida trama que conforma el universo del tango en el siglo XXI.Facultad de Arte
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