Development of Optimal Experimental Design Parameters for Pseudo Ambient Vibration Testing of Bridges

The United States of America is facing an infrastructure crisis that is characterized by aging and deteriorating structures, a significant backlog of maintenance and upgrades for existing infrastructure, limited funding and lack of practical and effective tools for identifying and prioritizing the most pressing infrastructure needs. The American Association of Civil Engineers (ASCE) qualifies America’s infrastructure with a D+(ASCE Report Card). This rating reflects the general state of infrastructure that is unlikely to improve dramatically in the short-term, yet the situation costs the nation billions of dollars annually due to losses in economic efficiency and productivity, and in some cases can needlessly expose communities to safety risks that would be considered unacceptable for other industries. There is a clear need for the development of better tools for assessing the condition of existing aged and deteriorated structures to support more timely and effective infrastructure maintenance management and planning decisions. The focus of this research is to improve upon an existing test method that is widely used for characterizing the performance of in-service bridges and other civil infrastructure systems. The specific characterization method explored here is known as ambient vibration testing (AVT). It involves measuring a structure’s vibration responses due to environmental and/or operating loads in order to quantitatively identify its dynamic characteristics and to evaluate its structural properties, performance and condition. The identified dynamic properties are mathematically related to the physical characteristics of the structure can be compared to a baseline characterization to identify and evaluate structural damage and deterioration. In AVT, the structure vibrates due to unmeasured dynamic forces from natural sources and operating traffic, and because these inputs are unknown, their characteristics must be assumed. Researchers at the University of Arkansas are trying to improve upon ambient vibration testing by using multiple low-cost shakers to provide known and controlled dynamic forces to the structure thereby reducing the uncertainty in this approach. Establishing the optimal test design parameters for this new vibration testing approach represents a critical need for improving the cost, reliability, and testing time requirements for this novel experimental method

Diagnóstico de la aplicación del Régimen Sancionatorio ambiental en Colombia: Ley 1333 de 2009

Artículo de investigaciónEl desarrollo de este artículo de reflexión presenta un análisis sobre el régimen ambiental sancionatorio existente en Colombia, el cual se promulgó con la expedición de la Ley 1333 del 21 de julio de 2009, contemplando aspectos fundamentales como la facultad dada a entidades del sector medioambiental para la imposición de las sanciones, los tipos de sanciones, el régimen probatorio dentro de ese procedimiento administrativo y la efectividad de las sanciones, respecto de la recuperación de los recursos afectados. La importancia de la realización de un análisis crítico a este régimen sancionatorio, permite evidenciar nuevas opciones en el proceso de imposición y ejecución de la sanción, de modo que si bien se sancione económicamente a las empresas que infringen la normativa ambiental existente, también se impongan obligaciones en materia de recuperación de los recursos que pudieran haber sufrido algún tipo de afectación, por las acciones desplegadas por el sancionado.Introducción. 1. Acercamiento a la legislación en materia ambiental sancionatoria en Colombia. 2. Discusión sobre las Infracciones y compensaciones en el régimen ambiental sancionatorio colombiano. 3. Estudio de sanciones impuestas de acuerdo a lo dispuesto en la Ley 1333 de 2009. Conclusiones. Referencia s.PregradoAbogad

De la autonomía a la independencia : la Junta Superior Gubernativa de Mérida

En mi presentación expongo un análisis del proceso constitutivo de la Junta Superior Gubernativa conservadora de los derechos de Fernando VII de Mérida, con sus peculiaridades y el significativo proceso de adhesión a la Junta emeritense, de ciudades y villas, que formaron la región histórica merideña durante el periodo de dominación hispánica.Fil: Samudio Aizpurúa, Edda Otilia

Proceso de poblamiento y asignación de resguardos en los Andes venezolanos.

Sin resume

Relación entre temperamento y problemas emocionales y conductuales en la adolescencia: Una revisión de la literatura.

55 Páginas.Este artículo tiene la finalidad de llevar a cabo una revisión bibliográfica de los estudios empíricos que buscan identificar la relación entre temperamento y problemas emocionales y conductuales en la adolescencia. Los problemas psicológicos estudiados fueron: depresión, ansiedad, trastornos de conducta alimentaria: anorexia y bulimia; el trastorno por déficit de atención con hiperactividad (TDAH), trastornos relacionados con sustancias y conductas adictivas. Las investigaciones referenciadas apuntan a la conclusión de que el temperamento no se considera eminentemente predominante en la aparición, mantenimiento y evolución de los problemas psicológicos; también existe una relación con el contexto, estudiada y sustentada en algunas de las investigaciones expuestas, llevadas a cabo en población adolescente con un rango de edad entre 11 y 18 años y diferentes nacionalidades dependiendo del lugar del estudio

Keratitis by Lasiodiplodia theobromae: a case report and literature review

We report a case of mycotic keratitis caused by Lasiodiplodia theobromae in a 60-year-old man with a history of ocular trauma with vegetable matter. Ophthalmological assessment with slit-lamp and microbiological evaluation of the corneal ulcer by conventional microbiological techniques were performed. Mycology study of the corneal scraping showed the presence of fungal filaments and the isolate was identified as Lasiodiplodia theobromae. Patient was treated with natamycin 5% and fluconazole 0.2% for 37 days. The infection was controlled but the corneal scars required a cornea transplant. This is the first case of keratitis by Lasiodiplodia theobromae in Paraguay. Difficulties in the management of these cases, which often requires surgical procedures, are discussed.Se presenta un caso clínico de queratitis causada por Lasiodiplodia theobromae en un agricultor de 60 años de edad, con antecedentes de un trauma ocular con un vegetal. Se realizó un examen oftalmológico con lámpara de hendidura y estudio microbiológico de la úlcera corneal por técnicas microbiológicas convencionales. El examen micológico del raspado corneal reveló la presencia de hifas septadas y el cultivo fue identificado como Lasiodiplodia theobromae. El paciente fue tratado con natamicina al 5% y fluconazol al 0,2% durante 37 días. La infección fue controlada, sin embargo, el paciente quedó con cicatrices corneales y con necesidad de trasplante. Es el primer caso de queratitis por Lasiodiplodia theobromae en Paraguay. Se discute la dificultad de manejo de estos casos que a menudo requieren procedimientos quirúrgicos y trasplante de córnea.Fil: Samudio, Margarita. Universidad Nacional de Asuncion; ParaguayFil: Laspina, Florentina. Universidad Nacional de Asuncion; ParaguayFil: Fariña, Norma. Universidad Nacional de Asuncion; ParaguayFil: Franco, Alicia. Banco de Ojos, “Don Fernando Oca del Valle”; ParaguayFil: Miño de Kaspar, Herminia. Technische Universitat Munchen; AlemaniaFil: Giusiano, Gustavo Emilio. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

What Do Studies of Insect Polyphenisms Tell Us about Nutritionally-Triggered Epigenomic Changes and Their Consequences?

Many insects are capable of remarkable changes in biology and form in response to their environment or diet. The most extreme example of these are polyphenisms, which are when two or more different phenotypes are produced from a single genotype in response to the environment. Polyphenisms provide a fascinating opportunity to study how the environment affects an animal’s genome, and how this produces changes in form. Here we review the current state of knowledge of the molecular basis of polyphenisms and what can be learnt from them to understand how nutrition may influence our own genomes

Effects of the breed, sex and age on cellular content and growth factor release from equine pure-platelet rich plasma and pure-platelet rich gel

Background: There is no information on the effects of the breed, gender and age on the cellular content and growth factor (GF) release from equine pure-platelet rich plasma (P-PRP) and pure-platelet rich gel (P-PRG). The objectives of this study were: 1) to compare the cellular composition of P-PRP with whole blood and platelet poor plasma (PPP); 2) to compare the concentration of transforming GF beta 1 (TGF-β1) and platelet derived GF isoform BB (PDGF-BB) between P-PRP treated with non-ionic detergent (P-PRP+NID), P-PRG (activated with calcium gluconate -CG-), PPP+NID, PPP gel (PPG), and plasma and; 3) to evaluate and to correlate the effect of the breed, gender and age on the cellular and GF concentration for each blood component. Forty adult horses, 20 Argentinean Creole Horses (ACH) and, 20 Colombian Creole Horses (CCH) were included. Data were analyzed by parametric (i.e.: t-test, one way ANOVA) and non parametric (Kruskal-Wallis test, Wilcoxon test) tests. Correlation analysis was also performed by using the Spearman and Pearson tests. A p ≤ 0.05 was set as significant for all tests. All the blood components were compared for platelet (PLT), leukocyte (WBC), TGF-β1 and PDGF-BB concentrations. The effect of the breed, gender and age on these variables was analyzed. A P ≤ 0.05 was accepted as significant for all the tests. Results: PLT counts were 1.8 and 0.6 times higher in P-PRP than in whole blood and PPP, respectively; WBC counts were 0.5 and 0.1 times lower in P-PRP, in comparison with whole blood and PPP, respectively. TGF-β1 and PDGF-BB concentrations were 2.3 and 262 times higher, respectively, in P-PRG than in plasma, and 0.59 and 0.48 times higher, respectively, in P-PRG than in PPG. P-PRG derived from CCH females or young horses presented significantly (P < 0.001) higher PDGF-BB concentrations than P-PRG derived from ACH males or older horses. Conclusions: Our results indicated that P-PRP obtained by a manual method was affected by intrinsic factors such as the breed, gender and age. Equine practitioners should be aware that cellular and GF release from P-PRP/P-PRG could change according with the intrinsic variables associated with a patient in particular