Papers by JUAN DAVID CHAVERRA CASTANO
This research studied alum recovery, using sulphuric acid, from sludge collected during settlers ... more This research studied alum recovery, using sulphuric acid, from sludge collected during settlers operation and maintenance routines in water potabilization systems. Jar tests were carried out at pHs of 1 .5, 2.5, 3.5 and slow mixing times of 5, 30 and 100 minutes. Alum recovery percentages from 18 to 64% were reached, generating solutions with Aluminium concentrations ranging from 8.9 to 1510 mg/l. Finally, the economical feasibility of reusing recovered alum solutions in the potabilization process was evaluated.
Actas españolas de psiquiatría, 2015
Introduction. To analyze factors associated with clinical observation, pharmacotherapy and referr... more Introduction. To analyze factors associated with clinical observation, pharmacotherapy and referral on discharge of patients with anxiety disorder (AD) seeking care at a psychiatric emergency unit. Method. A total of 5003 consecutive visits were reviewed over a three-year period at a psychiatric emergency service in a tertiary university hospital. Data collected included sociodemographic and clinical information as well as the Global Assessment of Functioning (GAF) and the Severity Psychiatric Illness (SPI) scale scores. Results. Of all the visits, 992 (19.8%) were diagnosed of AD. Of these, 19.6% required clinical observation and 72.2% were referred to a psychiatrist at discharge. Regression analysis showed that referral to psychiatry was associated with being male, native, psychiatric background, greater severity, lower global functioning, and behavioral disorders. Clinical observation (in a box) was associated with being female, greater severity, and psychotic or behavioral sympt...
Revista Estomatología, 2003
Revista Urologia Colombiana, 2012
Sociedad Colombiana de Urología escape) y la interpretación diagnóstica final, pueden verse influ... more Sociedad Colombiana de Urología escape) y la interpretación diagnóstica final, pueden verse influidas por la pérdida de información al no interpretarse el estudio en tiempo real, siendo una constante en cada uno de los centros analizados. Conclusión: La interpretación de la urodinamia en tiempo real es fundamental para sacar el mejor provecho de un estudio que no es estático y cuyo análisis puede verse afectado por la pérdida de información relevante que no puede ser registrada en una gráfica y que el intérprete puede obtener durante la realización del estudio. Palabras clave: urodinamia, concordancia, tiempo real. multicentric study to evaluate intraobserver accuracy in the analysis of urodynamic studies: differences between real-time and deferred interpretation
Linux Actual La Primera Revista En Castellano Del Sistema Operativo Gnu Linux, 1998
Para quienes creen que Linux es igual a Unix de Pc es una grata sorpresa poder comprobar que esto... more Para quienes creen que Linux es igual a Unix de Pc es una grata sorpresa poder comprobar que esto no es sino una falacia. Linux ha sido portado con exito a multiples arquitecturas y plataformas. Se presentan en este articulo las peculiaridades de instalacion y configuracion en una de las plataformas mas comunes en el mundo academico; las estaciones de trabajo SUN Sparc.
Murgetana, 2000
El cese de las hostilidades en el reino de Granada, con la toma de su capital en el año 1492, mar... more El cese de las hostilidades en el reino de Granada, con la toma de su capital en el año 1492, marcó el inicio de una bonanza económica para los reinos vecinos que no se quebraría hasta mediados del siglo XVI. '" únicamente pecheros, pues la relación de la que procede es netamente fiscal, hecha para la paga de los servicios ordinarios y extraordinarios^ ' Los datos del cuadro proceden del libro de Juan GONZÁLEZ CASTAÑO:
IFAC Proceedings Volumes, 2011
The Set Membership nonlinear identification method is a flexible technique, suitable for the iden... more The Set Membership nonlinear identification method is a flexible technique, suitable for the identification of non-linear systems where no information on the system structure is available. This method generates a non-parametric model, embedded on the identification data set, with optimality properties and bounds on the possible values the variable can assume. However, the complexity of the model grows with the product of the input dimension and the size of the data set. This is problematic when a big data set is employed. In this paper, the nearest point approximation to the exact Set Membership model, found in literature, is analyzed and a novel approximation is proposed, whose complexity does not depend on the size of the data set. Guaranteed bounds on the worst-case approximation error are given. Two examples, considering simulated and experimental data, illustrate the validity and applicability of the obtained results.
2010 IEEE ANDESCON, 2010
Recently, novel identification methods have been proposed based on orthogonal basis nonlinear fun... more Recently, novel identification methods have been proposed based on orthogonal basis nonlinear functions. These methods present strong statistical convergence properties but have not been evaluated from a computational point of view. This paper investigates the computational cost and performance of an orthogonal basis nonlinear system identification method. The computational effort of the model estimation and simulation are evaluated for an
IX Latin American Robotics Symposium and IEEE Colombian Conference on Automatic Control, 2011 IEEE, 2011
This paper presents the system identification techniques as an alternative to model processes for... more This paper presents the system identification techniques as an alternative to model processes for control purposes. A methodology for obtaining adequate empirical models for distillation columns is presented. This methodology is applied to a benchmark of a distillation column at laboratory scale (Column A). In this work, experimental data fit a state space model using subspace identification techniques.
2010 IEEE ANDESCON, 2010
Page 1. 1 Small Scale Prototype of a DC/DC Multilevel Converter for High Voltage Applications Jua... more Page 1. 1 Small Scale Prototype of a DC/DC Multilevel Converter for High Voltage Applications Juan Alejandro Castano, Gabriel Perilla, Rafael Diez and Diego Patino {j-castano, gabriel.perilla, rdiez, patino-d}@javeriana.edu ...
Revista ICONO14. Revista científica de Comunicación y Tecnologías emergentes, 2012
Este artículo se va a centrar en los aspectos creativos y heurísticos (arte de crear) de la obra ... more Este artículo se va a centrar en los aspectos creativos y heurísticos (arte de crear) de la obra ilustrada de Paul Gustave Doré. Para ello, vamos a buscar los elementos que definen la esencia de la creatividad y aplicarlos a la obra de este artista francés del siglo XIX, quien a pesar de poseer una de las obras que mayor difusión tiene en la historia de la humanidad, se presenta como un desconocido para la sociedad. Numerosas, han sido las publicaciones sobre creatividad y heurística, y, si algo hay claro, es la enorme cantidad de conceptos que se han usado para apreciar cómo y qué hace que una persona o un objeto, obra, trabajo, etc. sea creativo. De este modo, conceptos como fluidez, flexibilidad, elaboración, coherencia interna, adecuación, así como, la experiencia profesional han sido muy citados por los autores, junto con los de originalidad, imaginación, invención y muchos más. La creatividad, ha sido entendida como algo diferente a la inteligencia; aunque muchos autores consideran que radica en ella, ha sido objeto de estudio en múltiples investigaciones de muy diferente ámbito, tanto desde el
Journal of Human Genetics, 2009
Hypokalaemic periodic paralysis (HypoPP) is an autosomal dominant disorder, which is characterize... more Hypokalaemic periodic paralysis (HypoPP) is an autosomal dominant disorder, which is characterized by periodic attacks of muscle weakness associated with a decrease in the serum potassium level. A major disease-causing gene for HypoPP has been identified as CACNA1S, which encodes the skeletal muscle calcium channel a-subunit with four transmembrane domains (I-IV), each with six transmembrane segments (S1-S6). To date, all CACNA1S mutations identified in HypoPP patients are located within the voltage-sensor S4 segment. In this study we report a novel CACNA1S mutation in a new region of the protein, the S3 segment of domain III. We characterized a four-generation South American family with HypoPP. Genetic analysis identified a novel V876E mutation in all HypoPP patients in the family, but not in normal family members or 160 control people. Clinical analysis indicates that mutation V876E is associated with a severe outcome as characterized by a very early age of onset, complete penetrance and a severe prognosis including death. These results identify a new mutation in CACNA1S and expand the spectrum of CACNA1S mutations associated with HypoPP.
Actas de las XII Jornadas Ornitológicas Españolas …, 1997
CAMERAMAN, 2007
Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...
Dermatologic Therapy, 2013
Topical minoxidil is the most common drug used for the treatment of androgenetic alopecia (AGA) i... more Topical minoxidil is the most common drug used for the treatment of androgenetic alopecia (AGA) in men and women. Although topical minoxidil exhibits a good safety profile, the efficacy in the overall population remains relatively low at 30-40%. To observe significant improvement in hair growth, minoxidil is typically used daily for a period of at least 3-4 months. Due to the significant time commitment and low response rate, a biomarker for predicting patient response prior to therapy would be advantageous. Minoxidil is converted in the scalp to its active form, minoxidil sulfate, by the sulfotransferase enzyme SULT1A1. We hypothesized that SULT1A1 enzyme activity in the hair follicle correlates with minoxidil response for the treatment of AGA. Our preliminary retrospective study of a SULT1A1 activity assay demonstrates 95% sensitivity and 73% specificity in predicting minoxidil treatment response for AGA. A larger prospective study is now under way to further validate this novel assay.
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Papers by JUAN DAVID CHAVERRA CASTANO