Seismic behavior of posttensioned self-centering precast concrete dual-shell steel columns

This paper describes an innovative bridge column technology for application in seismic regions. The proposed technology combines a precast posttensioned composite steel-concrete hollow-core column, with supplemental energy dissipation, in a way to minimize postearthquake residual lateral displacements. The column consists of two steel cylindrical shells, with high-performance concrete cast in between. Both shells act as permanent formwork; the outer shell substitutes for the longitudinal and transverse reinforcement, because it works in composite action with the concrete, whereas the inner shell removes unnecessary concrete volume from the column, prevents concrete implosion, and prevents buckling of energy dissipating dowels when embedded in the concrete. Large inelastic rotations can be accommodated at the end joints with minimal structural damage, since gaps are allowed to open at these locations and to close upon load reversal. Longitudinal posttensioned high-strength steel threaded bars, designed to respond elastically, in combination with gravity forces ensure self-centering behavior. Internal or external steel devices provide energy dissipation by axial yielding. This paper describes the main requirements for the design of these columns and also discusses the experimental findings from two quasi-static tests

Modelo para el análisis de la aplicación de la NIC 41 en las empresas ganaderas en el departamento del Meta

La investigación se centra en el diseño de un modelo sobre el impacto de la Norma Internacional de Contabilidad (NIC 41), en la información financiera de las empresas ganaderas bovinas del departamento del Meta. Se analizan los conceptos y principios de la normatividad contable vigente (Decreto 2649/93) y la NIC 41 frente al efecto del registro del costo histórico y el valor razonable. Mediante la descripción casuística se simulan escenarios que incluyen el cálculo de indicadores financieros: Valor Presente Neto (VPN), la Tasa Interna de Retorno (TIR), la relación Beneficio Costo (B/C), generando un índice que permite comparar los resultados y los efectos en los estados financieros.The research is focused on the design of a model to know the impact of the International Accounting Standard (IAS 41), on the financial information of cattle enterprises in Meta State. Concepts and Principles of the current accounting standards (Decree 2649/93) and IAS 41, were analized, against the effect of historical register and the fair cost. By casuistry Description, some scenarios that include the calculation of financial indicators Net Present Value (NPV), Internal Return Rate (IRR), Benefit Cost (B / C) ratio are simulated; generating an index to compare the results, and the effects on the financial statements

Genome size and ploidy of Paracoccidioides brasiliensis reveals a haploid DNA content: Flow cytometry and GP43 sequence analysis

The aim of this study was to evaluate genome size and ploidy of the dimorphic pathogenic fungus Paracoccidioides brasiliensis. The cell cycle analysis of 10 P. brasiliensis isolates by flow cytometry (FCM) revealed a genome size ranging from 26.3+/-0.1Mb (26.9+/-0.1fg) to 35.5+/-0.2Mb (36.3+/-0.2fg) per uninucleated yeast cell. The DNA content of conidia from P. brasiliensis ATCC 60855-30.2+/-0.8Mb (30.9+/-0.8fg) -showed no significant differences with the yeast form, possibly excluding the occurrence of ploidy shift during morphogenesis. The ploidy of several P. brasiliensis isolates was assessed by comparing genome sizing by FCM with the previously described average haploid size obtained from electrophoretic karyotyping. The analysis of intra-individual variability of a highly polymorphic P. brasiliensis gene, GP43, indicated that only one allele seems to be present. Overall, the results showed that all analysed isolates presented a haploid, or at least aneuploid, DNA content and no association was detected between genome size/ploidy and the clinical-epidemiological features of the studied isolates. This work provides new knowledge on P. brasiliensis genetics/genomics, important for future research in basic cellular/molecular mechanisms and for the development/design of molecular techniques in this fungus

Parametric Probabilistic Seismic Performance Assessment Framework for Ordinary Standard Bridges

This paper focuses on the assembly and implementation of a full-fledged parametric probabilistic seismic performance assessment framework for ordinary standard bridges (OSBs) in California. The framework stems from the performance-based earthquake engineering (PBEE) assessment methodology developed under the auspices of the Pacific Earthquake Engineering Research (PEER) Center. It involves a sequential execution of analytical steps to arrive at estimates of performance measures which, for example as considered in this study, are the mean return periods (MRPs) of exceedances for a selected set of limit-states (LSs). Improvements from state-of-the-art literature related to various stages of the PEER PBEE assessment framework are incorporated. This includes: (1) introduction of an improved intensity measure (IM), i.e., average spectral acceleration over a period range, for probabilistic seismic hazard analysis (PSHA), (2) conditional mean spectrum (CMS)-based site-specific risk-consistent ground motions selection for ensemble nonlinear time-history analyses involved in probabilistic seismic demand hazard analysis (PSDemHA), (3) introduction of material strain-based engineering demand parameters (EDPs), (4) identification of practical damage LSs, and (5) development of strain-based fragility functions required in probabilistic seismic damage hazard analysis (PSDamHA) for the considered LSs. Four distinct testbed OSBs are selected for the study. A two-dimensional design parameter space is defined in terms of typical primary design variables involved in seismic design of OSBs, i.e., the column diameter and the column longitudinal steel reinforcement ratio. Computational models of the as-designed bridges as well as their re-designs spawned by varying the primary design variables subject to practical constraints are assessed using the implemented framework. For each testbed OSB, and for each of the considered LSs, a smooth surface is fitted to the MRPs computed for all the re-designs of the bridge in the primary design parameter space. Topologies of these surfaces are explored. Feasible design domains in the two-dimensional design parameter space are identified. Safety of the as-designed version and feasibility domain for the re-designs of each testbed OSB are examined and discussed.Support of this research by the California Department of Transportation under Grant No. 65A0594, Task No. 2880 is gratefully acknowledged. Opinions and findings in this study are those of the authors and do not necessarily reflect the views of the sponsor

Procalcitonin (PCT) levels for ruling-out bacterial coinfection in ICU patients with influenza: A CHAID decision-tree analysis

Objectives: To define which variables upon ICU admission could be related to the presence of coinfection using CHAID (Chi-squared Automatic Interaction Detection) analysis. Methods: A secondary analysis from a prospective, multicentre, observational study (2009-2014) in ICU patients with confirmed A(H1N1)pdm09 infection. We assessed the potential of biomarkers and clinical variables upon admission to the ICU for coinfection diagnosis using CHAID analysis. Performance of cut-off points obtained was determined on the basis of the binominal distributions of the true (+) and true (−) results. Results: Of the 972 patients included, 196 (20.3%) had coinfection. Procalcitonin (PCT; ng/mL 2.4 vs. 0.5, p < 0.001), but not C-reactive protein (CRP; mg/dL 25 vs. 38.5; p = 0.62) was higher in patients with coinfection. In CHAID analyses, PCT was the most important variable for coinfection. PCT <0.29 ng/mL showed high sensitivity (Se = 88.2%), low Sp (33.2%) and high negative predictive value (NPV = 91.9%). The absence of shock improved classification capacity. Thus, for PCT <0.29 ng/mL, the Se was 84%, the Sp 43% and an NPV of 94% with a post-test probability of coinfection of only 6%. Conclusion: PCT has a high negative predictive value (94%) and lower PCT levels seems to be a good tool for excluding coinfection, particularly for patients without shock

Nuevas tendencias en el diseño de materiales y estructuras

El presente texto incluye temas como las nuevas herramientas para la modelación de diferentes problemas relacionados con la Ingeniería Civil; la implantación de un modelo matemático para el análisis dinámico no lineal de las viviendas prefabricadas, que permite simular el comportamiento histerético del sistema estructural de la vivienda a partir del comportamiento cíclico experimental; las herramientas de la inteligencia artificial (las redes neuronales) para la modelación de fenómenos complejos presentes en el comportamiento de algunos materiales, en este caso en tres arenas típicas y su relación esfuerzo-deformación; nuevos enfoques en el diseño de estructuras y materiales, nuevas tendencias de diseño tanto de las estructuras como en los materiales compuestos; una perspectiva sobre nuevos materiales compuestos o alternativos, que proponen materiales de origen natural combinados con materiales tradicionales en la industria de la construcción. Presenta una breve descripción de los materiales compuestos, tipo sándwich, y propone un nuevo compuesto a partir de conglomerados de material vegetal y ferrocemento. E incluye el estudio de los suelos residuales estabilizados con cal y se evalúa su comportamiento mecánico.PRÓLOGO............. 15 PRESENTACIÓN.............. 17 Primera parte Nuevas herramientas para la modelación de problemas en Ingeniería Civil Capítulo 1 APLICACIÓN DEL MODELO DE Bouc y Wen EN EL ANÁLISIS SÍSMICO DE VIVIENDAS PREFABRICADAS Daniel Alveiro Bedoya Ruiz 1.1 INTRODUCCIÓN.............. 21 1.2 AVANCES EN EL MODELO DE Bouc y Wen............. 23 1.3 SISTEMAS HISTERÉTICOS NO LINEALES............ 27 1.3.1 Ecuación de movimiento............ 30 1.3.2 Parámetros de forma de la histéresis............ 31 1.3.3 Disipación de energía............. 34 1.3.4 Rigidez, resistencia y estrangulamiento..............35 1.4 Identificación de sistemas y control.............. 37 1.5 APLICACIÓN DEL MODELO EN VIVIENDAS PREFABRICADAS............. 38 1.5.1 El modelo en casas prefabricadas de ferrocemento............. 41 1.5.2 Dinámica y comportamiento no lineal............. 44 1.6 CONCLUSIÓN............ 45 Capítulo 2 DETERMINACIÓN DE LA RELACIÓN CONSTITUTIVA DE LAS ARENAS USANDO REDES NEURONALES ARTI FICIALES (RNA) Hernán Eduardo Martínez-Carvajal - Márcio Muniz de Farias 2.1 INTRODUCCIÓN............ 51 2.2 MODELAMIENTO CONSTITUTIVO DE MATERIALES........... 53 2.3 MODELAMIENTO CONSTITUTIVO USANDO REDES NEURONALES ARTIFICIALES............. 55 2.4 LA BASE DE DATOS............ 56 2.5 LA ARQUITECTURA DE LA RED NEURONAL............... 58 2.6 RESULTADOS DE LA SIMULACIÓN............. 60 2.7. CONCLUSIONES.............. 65 Segunda parte Nuevos enfoques en el diseño de materiales y estructuras Capítulo 3 Diseño por desplazamientos de pilares de puentes Matthew J. Tobolski - José I. Restrepo 3.1 INTRODUCCIÓN............ 69 3.2 ESPECTRO DEL DISEÑO............. 72 3.3 AMORTIGUAMIENTO............ 74 3.4 RESPUESTA INÉLASTICA............. 75 3.5 COMBINACIÓN DE FACTORES DE AMPLIFICACIÓN DE DESPLAZAMIENTO............. 79 3.6 CAPACIDAD DE DESPLAZAMIENTO............ 80 3.7 PROCEDIMIENTO DE DISEÑO............ 85 3.8 OBJETIVO DE DESEMPEÑO DE SEGURIDAD DE LA VIDA.............. 86 3.9 OBJETIVO DE DESEMPEÑO DE FUNCIONAMIENTO INMEDIATO.............. 89 3.10 DISEÑO DE LOS ELEMENTOS............. 92 3.11 ANÁLISIS PARAMÉTRICO............. 93 3.12 EXIGENCIA SÍSMICA Y DUCTILIDAD DE CURVATURA.............. 93 3.13 PROPORCIÓN DE LA ROTACIÓN RESIDUAL............. 94 3.14 DIÁMETRO Y ALTURA DE LA COLUMNA.............. 95 3.15 CONCLUSIONES.............. 98 3.16 APÉNDICE. EJEMPLO DE DISEÑO............... 99 Capítulo 4 UN NUEVO ENFOQUE PARA EL ANÁLISIS Y DISEÑO DE ESTRUCTURAS DE HORMIGÓN ARMADO Héctor Guillermo Urrego Giraldo 4.1 INTRODUCCIÓN.............. 111 4.2 COMPORTAMIENTO DEL HORMIGÓN............. 113 4.3 COMPORTAMIENTO DEL ACERO.............. 115 4.4 CURVATURA.............. 117 4.5 EJEMPLO 1.............. 123 4.6 MÉTODO PROPUESTO............... 136 4.7 EJEMPLO 2............. 138 4.8 CONCLUSIONES............... 144 Capítulo 5 DESEMPEÑO SÍSMICO DE PÓRTI COS PLANOS DE ACERO CON EL SISTEMA KNEE-BRACING Ricardo León Bonett Díaz - Carolina López Toro 5.1 INTRODUCCIÓN.............. 147 5.2 MARCO CONCEPTUAL.............. 149 5.3 CRITERIOS PARA ESCOGER EL KNEE Y EL BRACE.............. 151 5.4 CASO DE ESTUDIO............. 153 5.5 INCORPORACIÓN DEL DISPOSABLE KNEE BRACING............. 165 5.6 EVALUACIÓN DE LA CAPACIDAD SÍSMICA............. 167 5.7 ANÁLISIS DE RESULTADOS.............. 172 5.8 CONCLUSIONES................ 176 Capítulo 6 TENDENCIAS EN EL DISEÑO DE MEZCLAS ASFÁLTI CAS EN CALIENTE ¡MARSHALL vs SUPERPAVE! Carlos Rodolfo Marín Uribe 6.1 INTRODUCCIÓN.............. 179 6.2 DESCRIPCIÓN DE LAS METODOLOGÍAS DE DISEÑO............... 180 6.3 Algunas diferencias entre las dos metodologías.............. 190 6.4 DESARROLLO DE UN TRABAJO EXPERIMENTAL.............. 192 6.4.1 Selección de materiales............ 192 6.4.2 Obtención del porcentaje óptimo de asfalto........... 195 6.4.3 Caracterización mecánica y dinámica de las mezclas asfálticas............. 195 6.5 ANÁLISIS DE RESULTADOS.............. 203 6.6 CONCLUSIONES............... 204 Capítulo 7 EL EFECTO ARCO EN SUELOS John Mario García Giraldo 7.1 INTRODUCCIÓN............. 209 7.2 EL ARCO COMO FORMA ESTRUCTURAL.............. 210 7.2.1 Definición de arco.............. 210 7.2.2 Historia del arco como elemento estructural............. 211 7.3 F ORMAS DE ARCO............ 212 7.4 EFECTO DE LA GEOMETRÍA ESTRUCTURAL EN LA DISTRIBUCIÓN DE TENSIONES EN EL INTERIOR DE UN ELEMENTO............. 215 7.4.1 Esfuerzos en un elemento estructural............. 215 7.4.2 Distribución de tensiones en el interior de un elemento estructural............. 216 7.5 GEOMETRÍAS ÓPTIMAS............... 219 7.6 ESTUDIO DEL EFECTO ARCO EN LOS SUELOS............ 220 7.6.1 Efecto de arco sobre una escotilla móvil (trapdoor).............. 220 7.6.2 Análisis del efecto arco en los suelos por Terzaghi en 1945........... 222 7.7 ANÁLISIS DEL EFECTO ARCO EN LOS SUELOS POR HANDY EN 1985.............. 226 7.8 ANÁLISIS DEL EFECTO ARCO EN LOS SUELOS POR HARROP EN 1989.............. 233 7.9 ANÁLISIS DEL EFECTO ARCO EN LOS SUELOS POR SALGADO EN 2002.............. 237 7.10 CONCLUSIONES............ 241 Tercera parte Nuevos materiales compuestos o alternativos Capítulo 8 MATERIALES COMPUESTOS A BASE DE FERROCEMENTO Y MATERIAL VEGETA L Daniel Alveiro Bedoya Ruiz - Juan Camilo Aldana Barrera - Leonardo Ávila Vélez 8.1 INTRODUCCIÓN.............. 247 8.2 MATERIALES COMPUESTOS.............. 249 8.2.1 Núcleo............. 252 8.2.2 Corteza estructural............. 253 8.2.3 Sistemas constructivos............ 254 8.3 COMPORTAMIENTO EXPERIMENTAL DE LOS COMPUESTOS DE FERROCEMENTO Y MATERIAL VEGETAL............. 255 8.3.1 Núcleo de material vegetal............ 256 8.3.2 Corteza de ferrocemento.............. 260 8.3.3 A. 3.3 paneles de ferrocemento con núcleo vegetal............. 261 8.4 CONCLUSIONES.............. 266 Capítulo 9 COMPORTAMIENTO MECÁNICO DE SUELOS RESIDUALES ESTABILIZADO S César Augusto Hidalgo Montoya - Mario Alberto Rodríguez Moreno 9.1 INTRODUCCIÓN.............. 271 9.2 ESTABILIZACIÓN DE SUELOS CON CAL............. 273 9.3 PROPIEDADES RESILIENTES O RESILIENCIA............... 275 9.4 CARGAS EN EL PAVIMENTO.............. 276 9.4.1 Tipos de cargas que actúan............. 276 9.4.2 Duración de la carga cíclica............. 279 9.5 MÓDULO RESILIENTE............. 279 9.6 F ACTORES GENERALES QUE AFECTAN EL MÓDULO RESILIENTE............. 281 9.6.1 Factores que afectan el Mr de suelos finos............ 281 9.6.2 Factores que afectan el Mr de materiales granulares............ 284 9.7 ENSAYOS PARA DETERMINAR EL MÓDULO RESILIENTE.............. 286 9.8 CORRELACIONES............... 289 9.9 PROPIEDADES RESILIENTES DE SUELOS ESTABILIZADOS.............. 290 9.10 ENSAYOS DE LABORATORIO.............. 292 9.11 ANÁLISIS DE RESULTADOS............... 295 9.11.1 Compresión simple............ 296 9.11.2 Tracción indirecta............. 299 9.11.3 CBR............. 300 9.11.4 Módulo resiliente.............. 302 9.12 CONCLUSIONES.............. 30

Recomendaciones basadas en la evidencia del grupo andaluz para la reflexión e investigación en nutrición (Garin) para el manejo del paciente con síndrome de intestino corto

In order to develop evidence-based recommendations and expert consensus for the nutritional management of patients with short bowel syndrome (SBS), we conducted a systematic literature search using the PRISMA methodology plus a critical appraisal following the GRADE scale procedures. Pharmacological treatment with antisecretory drugs, antidiarrheal drugs, and somatostatin contributes to reducing intestinal losses. Nutritional support is based on parenteral nutrition; however, oral intake and/or enteral nutrition should be introduced as soon as possible. In the chronic phase, the diet should have as few restrictions as possible, and be adapted to the SBS type. Home parenteral nutrition (HPN) should be individualized. Single-lumen catheters are recommended and taurolidine should be used for locking the catheter. The HPN’s lipid content must be greater than 1 g/kg per week but not exceed 1 g/kg per day, and omega-6 fatty acids (ω6 FAs) should be reduced. Trace element vials with low doses of manganese should be used. Patients with chronic SBS who require long-term HPN/fluid therapy despite optimized treatment should be considered for teduglutide treatment. All patients require a multidisciplinary approach and specialized follow-up. These recommendations and suggestions regarding nutritional management in SBS patients have direct clinical applicability

Predictores de riesgo en una cohorte española con cardiolaminopatías. Registro REDLAMINA

[Abstract] Introduction and objectives. According to sudden cardiac death guidelines, an implantable cardioverter-defibrillator (ICD) should be considered in patients with LMNA-related dilated cardiomyopathy (DCM) and ≥ 2 risk factors: male sex, left ventricular ejection fraction (LVEF) < 45%, nonsustained ventricular tachycardia (NSVT), and nonmissense genetic variants. In this study we aimed to describe the clinical characteristics of carriers of LMNA genetic variants among individuals from a Spanish cardiac-laminopathies cohort (REDLAMINA registry) and to assess previously reported risk criteria. Methods. The relationship between risk factors and cardiovascular events was evaluated in a cohort of 140 carriers (age ≥ 16 years) of pathogenic LMNA variants (54 probands, 86 relatives). We considered: a) major arrhythmic events (MAE) if there was appropriate ICD discharge or sudden cardiac death; b) heart failure death if there was heart transplant or death due to heart failure. Results. We identified 11 novel and 21 previously reported LMNA-related DCM variants. LVEF < 45% (P = .001) and NSVT (P < .001) were related to MAE, but not sex or type of genetic variant. The only factor independently related to heart failure death was LVEF < 45% (P < .001). Conclusions. In the REDLAMINA registry cohort, the only predictors independently associated with MAE were NSVT and LVEF < 45%. Therefore, female carriers of missense variants with either NSVT or LVEF < 45% should not be considered a low-risk group. It is important to individualize risk stratification in carriers of LMNA missense variants, because not all have the same prognosis.[Resumen] Introducción y objetivos. Según las guías de muerte súbita, se debe considerar un desfibrilador automático implantable (DAI) para los pacientes con miocardiopatía dilatada debida a variantes en el gen de la lamina (LMNA) con al menos 2 factores: varones, fracción de eyección del ventrículo izquierdo (FEVI) < 45%, taquicardia ventricular no sostenida (TVNS) y variantes no missense. Nuestro objetivo es describir las características clínicas de una cohorte española de pacientes con cardiolaminopatías (registro REDLAMINA) y evaluar los criterios de riesgo vigentes. Métodos. Se evaluó la relación entre factores de riesgo y eventos cardiovasculares en una cohorte de 140 portadores de variantes en LMNA (54 probandos, 86 familiares, edad ≥ 16 años). Se consideró: a) evento arrítmico mayor (EAM) si hubo descarga apropiada del DAI o muerte súbita, y b) muerte por insuficiencia cardiaca, incluidos los trasplantes. Resultados. Se identificaron 11 variantes nuevas y 21 previamente publicadas. La FEVI < 45% (p = 0,001) y la TVNS (p < 0,001) se relacionaron con los EAM, pero no el sexo o el tipo de variante (missense frente a no missense). La FEVI < 45% (p < 0,001) fue el único factor relacionado con la muerte por insuficiencia cardiaca. Conclusiones. En el registro REDLAMINA, los únicos 2 predictores asociados con EAM fueron la TVNS y la FEVI < 45%. No se debería considerar grupo de bajo riesgo a las portadoras de variantes missense con TVNS o FEVI < 45%. Es importante individualizar la estratificación del riesgo de los portadores de variantes missense en LMNA, porque no todas tienen el mismo pronóstico.This study received a grant from the Proyecto de investigación de la Sección de Insuficiencia Cardiaca 2017 from the Spanish Society of Cardiology and grants from the Instituto de Salud Carlos III (ISCIII) [PI14/0967, PI15/01551, AC16/0014] and ERA-CVD Joint Transnational Call 2016 (Genprovic). Grants from the ISCIII and the Ministerio de Economía y Competitividad de España (Spanish Department of Economy and Competitiveness) are supported by the Plan Estatal de I+D+i 2013-2016: Fondo Europeo de Desarrollo Regional (FEDER) “Una forma de hacer Europa”

Class-modeling analysis reveals T-cell homeostasis disturbances involved in loss of immune control in elite controllers

Despite long-lasting HIV replication control, a significant proportion of elite controller (EC) patients may experience CD4 T-cell loss. Discovering perturbations in immunological parameters could help our understanding of the mechanisms that may be operating in those patients experiencing loss of immunological control. Methods A case–control study was performed to evaluate if alterations in different T-cell homeostatic parameters can predict CD4 T-cell loss in ECs by comparing data from EC patients showing significant CD4 decline (cases) and EC patients showing stable CD4 counts (controls). The partial least-squares–class modeling (PLS-CM) statistical methodology was employed to discriminate between the two groups of patients, and as a predictive model. Results Herein, we show that among T-cell homeostatic alterations, lower levels of naïve and recent thymic emigrant subsets of CD8 cells and higher levels of effector and senescent subsets of CD8 cells as well as higher levels of exhaustion of CD4 cells, measured prior to CD4 T-cell loss, predict the loss of immunological control. Conclusions These data indicate that the parameters of T-cell homeostasis may identify those EC patients with a higher proclivity to CD4 T-cell loss. Our results may open new avenues for understanding the mechanisms underlying immunological progression despite HIV replication control, and eventually, for finding a functional cure through immune-based clinical trials.projects RD12/0017/0031, RD16/0025/ 0013, and SAF2015-66193-R as part of the Health Research and Development Strategy, State Plan for Scientific and Technical Research and Innovation (2008– 2011 and 2013–2016) and cofinanced by the Institute of Health Carlos III (ISCIII), Sub-Directorate General for Research Assessment and Promotion and European Regional Development Fund. NR is a Miguel Servet investigator from the ISCIII (CP14/00198), Madrid, Spain. C Restrepo was funded by project RD12/0017/ 0031 and is currently funded by project RD16/0025/0013. M García is a predoctoral student co-funded by grant CP14/00198 and an Intramural Research Scholarship from Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD)