Respiratory support in patients with severe COVID-19 in the International Severe Acute Respiratory and Emerging Infection (ISARIC) COVID-19 study: a prospective, multinational, observational study

Invasive mechanical ventilation; COVID-19; Critical careVentilación mecánica invasiva; COVID-19; Cuidado críticoVentilació mecànica invasiva; COVID-19; Atenció críticaBackground Up to 30% of hospitalised patients with COVID-19 require advanced respiratory support, including high-flow nasal cannulas (HFNC), non-invasive mechanical ventilation (NIV), or invasive mechanical ventilation (IMV). We aimed to describe the clinical characteristics, outcomes and risk factors for failing non-invasive respiratory support in patients treated with severe COVID-19 during the first two years of the pandemic in high-income countries (HICs) and low middle-income countries (LMICs). Methods This is a multinational, multicentre, prospective cohort study embedded in the ISARIC-WHO COVID-19 Clinical Characterisation Protocol. Patients with laboratory-confirmed SARS-CoV-2 infection who required hospital admission were recruited prospectively. Patients treated with HFNC, NIV, or IMV within the first 24 h of hospital admission were included in this study. Descriptive statistics, random forest, and logistic regression analyses were used to describe clinical characteristics and compare clinical outcomes among patients treated with the different types of advanced respiratory support. Results A total of 66,565 patients were included in this study. Overall, 82.6% of patients were treated in HIC, and 40.6% were admitted to the hospital during the first pandemic wave. During the first 24 h after hospital admission, patients in HICs were more frequently treated with HFNC (48.0%), followed by NIV (38.6%) and IMV (13.4%). In contrast, patients admitted in lower- and middle-income countries (LMICs) were less frequently treated with HFNC (16.1%) and the majority received IMV (59.1%). The failure rate of non-invasive respiratory support (i.e. HFNC or NIV) was 15.5%, of which 71.2% were from HIC and 28.8% from LMIC. The variables most strongly associated with non-invasive ventilation failure, defined as progression to IMV, were high leukocyte counts at hospital admission (OR [95%CI]; 5.86 [4.83–7.10]), treatment in an LMIC (OR [95%CI]; 2.04 [1.97–2.11]), and tachypnoea at hospital admission (OR [95%CI]; 1.16 [1.14–1.18]). Patients who failed HFNC/NIV had a higher 28-day fatality ratio (OR [95%CI]; 1.27 [1.25–1.30]). Conclusions In the present international cohort, the most frequently used advanced respiratory support was the HFNC. However, IMV was used more often in LMIC. Higher leucocyte count, tachypnoea, and treatment in LMIC were risk factors for HFNC/NIV failure. HFNC/NIV failure was related to worse clinical outcomes, such as 28-day mortality.This work was supported by the UK Foreign, Commonwealth, and Development Office and Wellcome [215091/Z/18/Z] and the Bill & Melinda Gates Foundation [OPP1209135]; CIHR Coronavirus Rapid Research Funding Opportunity OV2170359; Grants from Rapid European COVID-19 Emergency Response research (RECOVER) [H2020 Project 101003589] and European Clinical Research Alliance on Infectious Diseases (ECRAID) [965313]; The Imperial NIHR Biomedical Research Centre; The Cambridge NIHR Biomedical Research Centre; and Endorsed by the Irish Critical Care-Clinical Trials Group, co-ordinated in Ireland by the Irish Critical Care-Clinical Trials Network at University College Dublin and funded by the Health Research Board of Ireland [CTN-2014-12]. This work uses Data/Materials provided by patients and collected by the NHS as part of their care and support #DataSavesLives. The Data/materials used for this research were obtained from ISARIC4C. The COVID-19 Clinical Information Network (CO-CIN) data was collated by ISARIC4C Investigators. Data and Material provision were supported by grants from: the National Institute for Health Research (NIHR; award CO-CIN-01), the Medical Research Council (MRC; Grant MC_PC_19059), and the NIHR Health Protection Research Unit (HPRU) in Emerging and Zoonotic Infections at the University of Liverpool in partnership with Public Health England (PHE), (Award 200907), Wellcome Trust [Turtle, Lance-fellowship 205228/Z/16/Z], NIHR HPRU in Respiratory Infections at Imperial College London with PHE (Award 200927), Liverpool Experimental Cancer Medicine Centre (Grant C18616/A25153), NIHR Biomedical Research Centre at Imperial College London (Award IS-BRC-1215-20013), and NIHR Clinical Research Network providing infrastructure support. This work was possible due to the dedication and hard work of the Norwegian SARS-CoV-2 study team and supported by grants from Research Council of Norway Grant No. 312780 and a philanthropic donation from Vivaldi Invest A/S owned by Jon Stephenson von Tetzchner; The dedication and hard work of the Groote Schuur Hospital Covid ICU Team, and supported by the Groote Schuur nursing and University of Cape Town registrar bodies coordinated by the Division of Critical Care at the University of Cape Town; and supported by the COVID clinical management team, AIIMS, Rishikesh, India

Análisis de elementos finitos con un continuo elástico lineal tipo Cosserat

Contexto: Los resultados experimentales en materiales granulares muestran que el comportamiento esfuerzo deformación tiene dependencia con la escala de análisis, sin embargo, debido a las supocisiones intrínsecas que tiene la mecánica del medio continuo, los análisis de elementos finitos basados en el continuo continuo de Boltzmann no permite tener en cuenta longitudes características en su formulación que refleje la escala.Método: En este trabajo se presenta la formulación especializada de los elementos finitos para un problema de deformación plana para el continuo de Cosserat. Se presentan los grados de libertad de un elemento finito cuadrilatero y se deduce el operador diferencial para obtener el vector de deformación, su función de forma, la matriz de interpolación, la matriz de rigidez y el vector de fuerza nodal. Finalmente se implementa el continuo de cosserat con el elemento descrito en un programa de elementos finitos codificado por los autores.  El programa se ejecuta para resolver el problema de esfuerzos y deformaciones en una capa homogenea de material con comportamiento lineal elástico.Resultados: Se obtiene las diferencias entre los componentes de esfuerzos y deformaciones de corte entre el continuo convencional y el de Cosserat junto con la aparición de momentos  a nivel de punto de Gauss.Conclusiones: La deducción e implementación del continuo de Cosserat permite un análisis de elementos finitos alternativo al del continuo Convencional con la posibilidad de introducir una longitud característica en su formulación para tener en cuenta los efectos de escala y rotaciones que se observan en materiales granulares.Contexto: Los resultados experimentales en materiales granulares muestran que el comportamiento esfuerzo deformación tiene dependencia con la escala de análisis, sin embargo, debido a las supocisiones intrínsecas que tiene la mecánica del medio continuo, los análisis de elementos finitos basados en el continuo continuo de Boltzmann no permite tener en cuenta longitudes características en su formulación que refleje la escala.Método: En este trabajo se presenta la formulación especializada de los elementos finitos para un problema de deformación plana para el continuo de Cosserat. Se presentan los grados de libertad de un elemento finito cuadrilatero y se deduce el operador diferencial para obtener el vector de deformación, su función de forma, la matriz de interpolación, la matriz de rigidez y el vector de fuerza nodal. Finalmente se implementa el continuo de cosserat con el elemento descrito en un programa de elementos finitos codificado por los autores.  El programa se ejecuta para resolver el problema de esfuerzos y deformaciones en una capa homogenea de material con comportamiento lineal elástico.Resultados: Se obtiene las diferencias entre los componentes de esfuerzos y deformaciones de corte entre el continuo convencional y el de Cosserat junto con la aparición de momentos  a nivel de punto de Gauss.Conclusiones: La deducción e implementación del continuo de Cosserat permite un análisis de elementos finitos alternativo al del continuo Convencional con la posibilidad de introducir una longitud característica en su formulación para tener en cuenta los efectos de escala y rotaciones que se observan en materiales granulares

Finite Element Analysis Using a Cosserat Linear Elastic Continuum

RESUMEN: Contexto: Los resultados experimentales en materiales granulares muestran que el comportamiento esfuerzo deformación tiene dependencia con la escala de análisis, sin embargo, debido a las supocisiones intrínsecas que tiene la mecánica del medio continuo, los análisis de elementos finitos basados en el continuo de Boltzmann no permite tener en cuenta longitudes características en su formulación que refleje la escala. Método: En este trabajo se presenta la formulación especializada de los elementos finitos para un problema de deformación plana para el continuo de Cosserat. Se presentan los grados de libertad de un elemento finito cuadrilatero y se deduce el operador diferencial para obtener el vector de deformación, su función de forma, la matriz de interpolación, la matriz de rigidez y el vector de fuerza nodal. Finalmente se implementa el continuo de cosserat con el elemento descrito en un programa de elementos finitos codificado por los autores. El programa se ejecuta para resolver el problema de esfuerzos y deformaciones en una capa homogenea de material con comportamiento lineal elástico. Resultados: Se obtiene las diferencias entre los componentes de esfuerzos y deformaciones de corte entre el continuo convencional y el de Cosserat junto con la aparición de momentos a nivel de punto de Gauss. Conclusiones: La deducción e implementación del continuo de Cosserat permite un análisis de elementos finitos alternativo al del continuo Convencional con la posibilidad de introducir una longitud característica en su formulación para tener en cuenta los efectos de escala y rotaciones que se observan en materiales granulares.ABSTRACT: Context: Experimental results show that the stress-strain behavior of granular materials depends upon the scale analysis. However, due to the intrinsic assumptions of the mechanics of a continuum medium, the analysis of finite elements based on the Boltzmann´s continuum does not allow to consider characteristic lengths in its formulation to reflect the scale effect. Method: This work presents a finite element formulation to analyze plane-strain linear problems using the Cosserat continuum. The degrees of freedom of a four-node quadrilateral finite element are presented and the differential operator is derived to obtain the deformation vector, function form, interpolation matrix, stiffness matrix and nodal load vector. Finally, the Cosserat continuum with the aforementioned element is implemented in a finite element software coded by the authors. The software is used to solve a stress-strain problem of a homogeneous layer with a linear elastic behavior. Results: The differences of the stress and shear strain responses between the conventional and the Cosserat continuum along with the moments acting at the Gauss point level are obtained. Conclusions: The derivation and implementation of the Cosserat continuum provides an alternative finite element analysis to the conventional continuum, along with the advantage of introducing a characteristic length in the formulation to account for the scale effects and rotations observed in granular materials

Niveles umbrales de lluvia que generan deslizamientos: Una revisión crítica

Multiple rainfall-landslides relationships have been proposed for early warning systems in the world. This work presents a data base that synthesizes the state of the art of rainfall thresholds that generate mass movements in the entire world. The more common rainfall-landslides relationships are processed in order to analyze data in function of the Köppen climatic classification and the area for which it was proposed. The results show a wide range of parameters derived from rainfall that triggers landslides together with considerable differences between threshold values. Data analysis shows the necessity to obtain parameters and thresholds derived from the rainfall that generate landslides for each specific geographical and climatic zone. For that reason, it is possible to generate a rational background that allows us to establish early warning systems of landslides caused by rainfall with low variability. This work provides insights into the catalog of possible parameters derived from rainfall records that allow us to generate thresholds to predict the landslides occurrence. Researchers will have the possibility to search for rainfall-landslide relationships based on statistical analysis, with a wide spectrum of parameters, beyond the traditional variables of antecedent rainfall and the intensity occurred the day of the landslide. En el mundo se han propuesto múltiples relaciones lluvia-deslizamientos para sistemas de alerta temprana. Este trabajo presenta una base de datos que sintetiza el estado del arte de umbrales de lluvia que generan movimientos en masa en todo el mundo. Las relaciones más comunes lluvia-deslizamiento se procesan con el fin de analizar los datos en función de la clasificación climática de Köppen y el área para la cual fue generada. Los resultados muestran la amplia oferta disponible de tipos de parámetros derivados de lluvia que producen deslizamientos, unido con las diferencias considerables en los valores umbrales que pueden tomar dichos parámetros. Estos resultados se condensan en figuras comparativas de niveles umbrales de lluvia que generan deslizamientos propuestos en el mundo para diferentes parámetros. Del análisis de la información recopilada resulta evidente la necesidad de obtener parámetros y umbrales derivados de lluvia que generan deslizamientos para cada zona geográfica y climática específica, de forma tal que se pueda generar una base racional de conocimiento que permita establecer sistemas de alerta temprana de deslizamientos detonados por lluvias con baja variabilidad. Este trabajo aporta en la construcción del conocimiento del catálogo de posibles parámetros derivados de registros de precipitación que permiten generar umbrales de predicción de ocurrencia de deslizamientos. Los investigadores tendrán la posibilidad de buscar relaciones lluvia-deslizamiento, basadas en análisis estadísticos, con una amplia paleta de parámetros, más allá de las variables tradicionales de lluvia antecedente e intensidad ocurrida el día del deslizamiento

Degradabilidade in situ de híbridos de milho e de capim-elefante colhidos em quatro estádios de maturidade

Dentre as forragens, a silagem de milho é amplamente utilizada pelos fazendeiros que visam explorar o máximo do potencial genético dos animais. No entanto, outros volumosos tropicais como o capim-elefante (Pennisetum purpureum) são mais produtivos e, portanto, mais baratos do que a silagem de milho. Nosso objetivo foi comparar a degradabilidade in situ do capim-elefante com a degradabilidade de híbridos de milho, colhidos em quatro estágios de maturidade. O experimento seguiu um delineamento de blocos ao acaso com sub-parcelas. Dois híbridos de milho: AG5011 e ZN8392 foram colhidos com 25, 30, 35 e 40% matéria seca (MS) na planta toda e separados na fração colmo + bainha + folhas e espigas. Capim elefante foi colhido 30, 40, 50 e 60 dias após o corte de nivelamento. As amostras secas e trituradas foram incubadas no rúmen por 0, 6, 12, 24, 48 e 72 h para cálculo da cinética da degradação ruminal da MS e da fibra em detergente neutro (FDN). O avanço da maturidade aumentou os teores de FDN e fibra em detergente ácido (FDA) do capim elefante e reduziu a degradabilidade da MS. Entretanto, a maturidade teve pouco efeito sobre os teores de fibra e a degradabilidade da MS da fração planta dos híbridos de milho. O capim elefante apresentou maior degradabilidade da FDN do que híbridos de milho, e não houve efeito da maturidade sobre a degradabilidade da FDN das duas espécies. A degradabilidade da fibra de capim-elefante não é pior do que a de híbridos de milho e, portanto a escolha da forragem deve ser feita com base em análises econômicas ao invés de assumir um menor potencial de produção em dietas a base de capim elefanteAmong tropical forages, corn silage is largely used by farmers trying to explore the maximum genetic potential from the animals. However, other tropical forages, such as elephant-grass (Pennisetum purpureum), are more productive and therefore cheaper to use than corn silage. Our objective was to compare the in situ degradability of elephant-grass with that from corn hybrids, all harvested at four stages of maturity. The experimental design followed a randomized block design with nested subplots. Two corn hybrids: AG5011, ZN8392 were harvested with 25, 30, 35, and 40% dry matter (DM) in the whole plant, and separated in stem + leaf sheath + leaf blade (stover), and cobs. Elephant-grass was harvested with 30, 40, 50 and 60 days after a leveling cut. Dried and ground samples were incubated in nylon bags inside the rumen for 0, 6, 12, 24, 48 and 72 h to estimate the kinetics of ruminal DM and neutral detergent fiber (NDF) degradation. The advance of maturity increased the NDF and acid detergent fiber (ADF) content in elephant-grass, and reduced its DM degradability. However, maturity had little or no effect on fiber content and DM degradability of corn stover. Elephant-grass had a higher NDF degradability than corn stover, and there was no effect of maturity on NDF degradability of either elephant-grass or corn stover. Fiber degradability of elephant-grass was not worse than that of corn stover, and therefore the choice of forage should be made on economical analysis rather than assuming an intrinsic low production potential for elephant-grass based diet

Infraestructura para explotación de datos de un simulador azucarero

[Resumen] En este trabajo mostramos el desarrollo de una posible infraestructura para implementar algoritmos RTO (Real Time Optimization, optimización en tiempo real) en un sistema industrial. Para ello, construiremos el sistema sobre un simulador de una factoría azucarera que nos permita probar los algoritmos en simulación. Como base de datos industrial que permita el almacenamiento y análisis de los datos usaremos el PI System de la empresa Osisoft®. Finalmente, como entorno desde el que probar los algoritmos RTO usaremos Matlab de la empresa Mathworks®.Ministerio de Economía y Competitividad; DPI2015-70975-

Major adverse cardiovascular events (MACE) in patients with severe COVID-19 registered in the ISARIC WHO clinical characterization protocol: A prospective, multinational, observational study

COVID-19; Complications; MortalityCOVID-19; Complicacions; MortalitatCOVID-19; Complicaciones; MortalidadPurpose To determine its cumulative incidence, identify the risk factors associated with Major Adverse Cardiovascular Events (MACE) development, and its impact clinical outcomes. Materials and methods This multinational, multicentre, prospective cohort study from the ISARIC database. We used bivariate and multivariate logistic regressions to explore the risk factors related to MACE development and determine its impact on 28-day and 90-day mortality. Results 49,479 patients were included. Most were male 63.5% (31,441/49,479) and from high-income countries (84.4% [42,774/49,479]); however, >6000 patients were registered in low-and-middle-income countries. MACE cumulative incidence during their hospital stay was 17.8% (8829/49,479). The main risk factors independently associated with the development of MACE were older age, chronic kidney disease or cardiovascular disease, smoking history, and requirement of vasopressors or invasive mechanical ventilation at admission. The overall 28-day and 90-day mortality were higher among patients who developed MACE than those who did not (63.1% [5573/8829] vs. 35.6% [14,487/40,650] p < 0.001; 69.9% [6169/8829] vs. 37.8% [15,372/40,650] p < 0.001, respectively). After adjusting for confounders, MACE remained independently associated with higher 28-day and 90-day mortality (Odds Ratio [95% CI], 1.36 [1.33–1.39];1.47 [1.43–1.50], respectively). Conclusions Patients with severe COVID-19 frequently develop MACE, which is independently associated with worse clinical outcomes

Aplicabilidad de la energía cinética en el inicio de la inestabilidad de materiales granulares en un tambor rotador mediante la técnica PIV (Particle Image Velocimetry)

This article presents a study of the behavior of granular materials that are subject to a process of instability in a rotating drum. By employing an original procedure, the applicability of kinetic energy as a parameter to measure processes of instability and their relationships with the granulometry of materials and rotating drum’s velocities are evaluated. Certain granulometries are tested in various set-ups in order to capture consecutive images of the process in which the present materials flow into the rotating drum. Image processing is carried out by using the Particle Image Velocimetry (PIV) technique in order to be able to determine the particles’ displacement vectors and velocity fields by using Pivlab, the Matlab toolbox. Subsequently, the kinetic energy is calculated and its applicability is determined through analyzing the variation of this parameter in the processes of instability and its relationship with the granulometry of materials and the velocities of the rotating drum. The trials undertaken as part of this study have determined that there are two types of particle flow: falling and rolling. Moreover, the dependence of the material type on the threshold value of kinetic energy at the beginning of the process of instability was discovered as well as the independence of this parameter from the angle of inclination of the material inside the rotating drum. The results from this research allow for an analysis of the processes of instability in granular materials by means of non-conventional methodologiesSe presenta un estudio del comportamiento de materiales granulares sometidos a procesos de inestabilidad en un tambor rotador. Mediante un procedimiento novedoso se evalúa la aplicabilidad de la energía cinética como parámetro de medición de procesos de inestabilidad y su relación con las granulometrías de los materiales y las velocidades de rotación del tambor. Determinadas granulometrías se ensayan en diferentes montajes, para la captura de imágenes consecutivas del proceso de flujo de los materiales presentes en el tambor rotador. El procesamiento de las imágenes es realizado mediante la técnica de Particle Image Velocimetry (PIV) para así poder determinar los vectores de desplazamiento y el campo de velocidad de las partículas, utilizando el toolbox de Matlab llamado Pivlab. Posteriormente se calcula la energía cinética y se determina su aplicabilidad mediante el análisis de la variación de este parámetro en los procesos de inestabilidad y su relación con las granulometrías de los materiales y las velocidades de rotación del tambor. En los ensayos realizados se determinaron dos tipos de flujo de partículas: régimen de caída y régimen rodante. Además, se encontró la dependencia del tipo de material en el valor umbral de energía cinética al inicio del proceso de inestabilidad y la independencia de este parámetro del ángulo de inclinación del material dentro del tambor rotador. Los resultados de este proyecto permiten un análisis de los procesos de inestabilidad en materiales granulares mediante metodologías no convencionales

Efeito de diferentes fontes de carboidratos não-fibrosos sobre o pH ruminal e digestibilidade in vitro de forragens tropicais

O presente estudo teve como objetivo avaliar os carboidratos não-fibrosos (CNF) em dietas à base de cana-de-açúcar sobre o pH ruminal e digestibilidade da forragem, e descrever as curvas de degradação dos CNF. O estudo foi composto de dois ensaios. No primeiro, três novilhos canulados no rúmen, com peso vivo de 350&nbsp;±&nbsp;15&nbsp;kg (Média ± DP), foram alocados em um quadrado latino (QL) 3×3, e alimentados com dietas contendo: milho moído (MM, tamanho de partículas 0,9&nbsp;mm), laminado a vapor (MLV) ou polpa cítrica peletizada (PCP). Cada período tinha 14&nbsp;d, sendo os primeiros 12 para adaptação e o 13º para a medição seriada do pH e o 14º para a coleta de líquido ruminal e incubação in vitro para digestibilidade da MS e FDN (DIVMS e DIVFDN) de feno de bermudagrass (Feno) e silagens de milho (SM) e cana (SC). No segundo ensaio, coletou-se fluido ruminal de um touro canulado, alimentado com silagem de milho e concentrado padrão, para digestão in vitro dos CNF em vários tempos. Esses resultados foram utilizados para ajustar as curvas de degradação dos CNF e calcular o tempo de colonização, frações alimentares e taxa de degradação. Os resultados do primeiro ensaio foram analisados em um QL 3×3. O modelo dos parâmetros de digestibilidade incluiu efeito fixo de forragem (Alimento), dieta com CNF (Dieta) e interação (Alimento × Dieta), e efeito aleatório de animal e período. O modelo para pH incluiu efeito fixo de Dieta, Tempo como medida repetida, animal e período como aleatórios. Foi considerada a probabilidade significativa de ≤&nbsp;5% (α&nbsp;=&nbsp;0,05). As curvas de degradação dos CNF foram ajustadas pelo PROC NLIN do SAS, e parâmetros de equação comparados por intervalo de confiança. Houve interação Dieta × Tempo no pH ruminal (P&nbsp;=&nbsp;0,04), onde o MLV diminuiu o pH comparado com PCP e MM apenas no tempo 6&nbsp;h. Não houve interação Alimento×Dieta (P&nbsp;&gt;&nbsp;0,05) para nenhum parâmetro de digestibilidade. Houve efeito de Alimento sobre a DIVMS e DIVFDN, após 30 e 48&nbsp;h de incubação (P&nbsp;&lt;&nbsp;0,01). A SM teve a maior DIVMS, seguido por SC e Feno, após 30 e 48&nbsp;h de incubação. A SM teve a maior DIVFDN após 30&nbsp;h, comparado com SC e Feno. No entanto, para DIVFDN após 48&nbsp;h, a SM teve maior média, seguida da SC e Feno. O fluido ruminal de animais alimentados com MLV diminuiu a DIVMS e DIVFDN (P&nbsp;&lt;&nbsp;0.05) de todas as forragens, após 48&nbsp;h. Resultados do segundo ensaio mostram que PCP diminuiu o tempo de colonização, fração B e aumentou a kd comparado com os dois milhos, e MLV apresentou maior kd que o MM. Em conclusão, a dieta com MLV diminuiu o pH ruminal no tempo 6&nbsp;h e, consequentemente, diminuiu a DIVFDN das forragens avaliadas. Embora PCP tenha apresentado menor tempo de colonização e maior taxa de degradação da fração B, não afetou negativamente o pH do rúmen nem a digestibilidade da fibra das forragens.The present study aimed to evaluate non-fiber carbohydrates (NFC) in sugarcane-based diets on rumen pH, and forage digestibility, and to describe NFC degradation curves. The study consisted of two trials. For the first trial, three rumen cannulated steers, BW of 350 ± 15&nbsp;kg (mean ± SE), were assigned in a 3×3 Latin Square (LS) design. They were fed diets containing finely-ground (0.9&nbsp;mm average particle size) corn (GC), steam-rolled corn (SRC), or pelleted citrus pulp (PCP). Each period had 14&nbsp;d, with the first 12 for adaptation. The 13th d was for serial measurement of rumen pH, and the14th for rumen fluid collection and in vitro incubation for DM and NDF digestibility (IVDMD and IVNDFD) of bermudagrass hay (Hay), corn (CS), and sugarcane (SS) silages. In the second trial, rumen fluid of a cannulated bull, fed corn silage and a regular concentrate, was collected for in vitro digestion of NFC for multiple time points. The incubation results were used to adjust the NFC degradation curves, and calculate lag-time, feed fractions, and degradation rate. Data from first trial was analyzed in a 3×3 LS. The model for the digestibility parameters included fixed effects of forage (Feed), diets with NFC (Diet), and their interaction (Feed × Diet), and random effect of animal and period. The model for rumen pH included fixed effect of diet, time as repeated measures, animal and period as random effects. The significance was considered at probability ≤&nbsp;5% (α&nbsp;=&nbsp;0.05). The NFC degradation curves were adjusted using the PROC NLIN procedure from SAS, and equation parameters compared using confidence intervals. There was a Diet × Time interaction on rumen pH (P&nbsp;=&nbsp;0.04), where SRC decreased pH compared to PCP and GC diets at the time 6&nbsp;h, only. There was no Feed × Diet interaction effect (P&nbsp;&gt;&nbsp;0.05) for any digestibility parameter. There was a Feed effect on both IVDMD and IVNDFD, either after 30 or 48&nbsp;h incubation (P&nbsp;&lt;&nbsp;0.01). The CS had the greatest IVDMD, followed by SS and Hay, after 30 and 48 h of incubation. The CS had the greatest IVNDFD after 30&nbsp;h, compared to SS and Hay. However, for IVNDFD after 48&nbsp;h, CS presented the greatest mean, followed by SS and Hay. The rumen fluid from animals fed SRC decreased both IVDMD and IVNDFD (P&nbsp;&lt;&nbsp;0.05) of all roughages after 48&nbsp;h. Results from the second trial showed that the PCP had lower Lag Time, B fraction and greater kd compared to both corn sources, and SRC had greater kd than GC. In conclusion, the SRC diet decreased rumen pH 6&nbsp;h after feeding and, consequently, decreased fiber digestibility of the tropical forage sources evaluated. Although the PCP had lower lag time, and faster rate of degradation of B fraction, it did not negatively affect rumen pH or fiber digestibility of forage

Incremento Del Nivel De Persistencia De Los Clientes De Los Sectores Socioeconómicos A Y B Con La Implantación Del Marketing Relacional En La Empresa El Pacifico Vida Cía. De Seguros Y Reaseguros

El presente trabajo de investigación plantea la implementación de Marketing Relacional en la empresa El Pacifico VIDA Cía. de Seguros y Reaseguros, lo cual se implementará utilizando el Modelo de los Seis Mercados, estrategia propuesta por Peck H, Payne A, Christopher M, Clark M. (1999). Con la implementación de esta estrategia o modelo de marketing, la empresa obtendría mayores conocimientos sobre sus clientes, y mejoraría el proceso de atención, la idea es alcanzar una relación a largo plazo entre ambos (empresa y cliente). El problema que existe en la empresa El Pacifico VIDA Cía. de Seguros y Reaseguros es que La persistencia, método por la cual se mide los datos numéricos de valores relacionados con la inversión de una determinada empresa, en este caso mostramos La persistencia de la empresa El Pacifico VIDA Cía. de Seguros y Reaseguros la cual es según fuente de la Oficina de Gerencia del cliente, a través del informe de Persistencia al cierre de julio de 2014. La Persistencia de Vida disminuyó de 76.35% del mes de junio, a 76.07%, para el mes de julio. Por lo tanto, el objetivo es Incrementar el nivel de persistencia de los clientes de los sectores socioeconómicos “A y B” de la empresa, pero con la implementación del Marketing Relacional se obtendría la fidelidad del cliente donde éste es más accesible a la adquisición de nuevos productos y servicios prestados por la empresa.The present research project proposes the implementation of Relational Marketing in the company El Pacifico VIDA Cía. of Insurance and Reinsurance, which will be implemented using the Six Market Model, strategy proposed by Peck H, Payne A, Christopher M, Clark M. (1999). With the implementation of this marketing strategy or model, the company would obtain greater knowledge about its customers, and improve the process of attention, the idea is to achieve a long-term relationship between both (company and client). The problem that exists in the company El Pacifico VIDA Cía. of Insurance and Reinsurance is that the persistence, method by which the numerical data of values related to the investment of a certain company is measured, in this case we show The persistence of the company El Pacifico VIDA Cía. of Insurance and Reinsurance which is according to the source of the client's Management Office, through the Persistence report at the close of July 2014: The Persistence of Life decreased from 76.35% in June, to 76.07%, for the month of July. Therefore, the objective is to increase the level of persistence of the clients of the socio-economic sectors "A and B" of the company but with the implementation of the Relational Marketing, the loyalty of the client would be obtained where this is more accessible to the acquisition of new products and services provided by the company.Trabajo de investigació