Prevalencia de equinococosis canina en predios asesorados por prodesal en el sector sur de la zona rural de la comuna de Melipilla, Región Metropolitana

El objetivo de este estudio fue determinar la prevalencia de equinococosis canina en perros pertenecientes apredios asesorados por el Programa de Desarrollo Local (PRODESAL) en el área rural del sector sur de lacomuna de Melipilla, Región Metropolitana, Chile, en el año 2012. Se utilizaron muestras de heces deperros pertenecientes a 64 usuarios con producción ganadera asesorados por PRODESAL. Las muestrasfueron procesadas por la técnica de reacción de polimerasa en cadena (PCR) en el Laboratorio ClínicoCAMPVS ubicado en Santiago. De 244 perros muestreados, 17 de ellos (6,9%) resultaron positivos a lapresencia de E. granulosus, por lo contrario 227 perros (93,1%) resultaron no tener dicho parásito. Esimportante contar con esta información para poder establecer programas de control de esta parasitosis en lapoblación canina y así, disminuir el número de animales y personas afectadas por ella.  

Automated generation of computationally hard feature models using evolutionary algorithms

This is the post-print version of the final paper published in Expert Systems with Applications. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2014 Elsevier B.V.A feature model is a compact representation of the products of a software product line. The automated extraction of information from feature models is a thriving topic involving numerous analysis operations, techniques and tools. Performance evaluations in this domain mainly rely on the use of random feature models. However, these only provide a rough idea of the behaviour of the tools with average problems and are not sufficient to reveal their real strengths and weaknesses. In this article, we propose to model the problem of finding computationally hard feature models as an optimization problem and we solve it using a novel evolutionary algorithm for optimized feature models (ETHOM). Given a tool and an analysis operation, ETHOM generates input models of a predefined size maximizing aspects such as the execution time or the memory consumption of the tool when performing the operation over the model. This allows users and developers to know the performance of tools in pessimistic cases providing a better idea of their real power and revealing performance bugs. Experiments using ETHOM on a number of analyses and tools have successfully identified models producing much longer executions times and higher memory consumption than those obtained with random models of identical or even larger size.European Commission (FEDER), the Spanish Government and the Andalusian Government

Asymptotic Expansions of Jacobi Polynomials for Large Values of Beta

Asymptotic approximations of Jacobi polynomials are given for large values of the Beta-parameter and of their zeros. The expansions are given in terms of Laguerre polynomials and of their zeros. The levels of accuracy of the approximations are verified by numerical examples.This work was supported by Ministerio de Econom a y Competitividad, project MTM2015-67142-P (MINECO/FEDER, UE). NMT thanks CWI, Amsterdam, for scienti c support

On the computation and inversion of the cumulative noncentral beta distribution function

The computation and inversion of the noncentral beta distribution Bp,q(x, y) (or the noncentral F-distribution, a particular case of Bp,q(x, y)) play an important role in different applications. In this paper we study the stability of recursions satisfied by Bp,q(x, y) and its complementary function and describe asymptotic expansions useful for computing the function when the parameters are large. We also consider the inversion problem of finding x or y when a value of Bp,q(x, y) is given. We provide approximations to x and y which can be used as starting values of methods for solving nonlinear equations (such as Newton) if higher accuracy is needed

L'Estudi de les funcions utilitzant el full de càlcul com a eina de treball : anàlisi d'un procès constructiu basat en la manipulació i la visualització /

Consultable des del TDXTítol obtingut de la portada digitalitzadaAnalitzem el procés d'aprenentatge de l'alumnat d'ensenyament secundària en relació a l'estudi de funcions amb la utilització del full de càlcul com a eina de treball sota un model metodològic constructiu enfocat en la manipulació la visualització. Com a treball d'innovació pretenem dissenyar i construir una seqüència d'aprenentatge sobre les funcions i implementar la unitat didàctica elaborada. Com a recerca, en primer lloc, analitzar el procés d'aprenentatge dels alumnes en relació als continguts treballats en el tema de funcions, l'eina informàtica (full de càlcul), la metodologia emprada, la unitat didàctica elaborada i l'actitud de l'alumnat. I en segon lloc, millorar la unitat didàctica elaborada i que constitueix part del currículum de l'aprenentatge. Aquests quatre objectius es concreten en: a) Revisar, en procés constructiu, la unitat didàctica dissenyada i elaborar una nova proposta, partint de l'anàlisi i la classificació de les dificultats i/o els errors comesos pels alumnes en relació a l'estudi de les funcions i en l'ús del full de càlcul per estudiar-les i , en concret atenent a les seves característiques, intentant determinar els motius que els provoquen. b) Valorar com influencia, en el procés d'aprenentatge de l'alumnat, el full de càlcul. c) Revisar la metodologia de treball desenvolupada en la innovació didàctica en l'estudi de funcions utilitzant el full de càlcul sota un procés constructiu enfocat en la manipulació i la visualització. d) Concretar les actituds de l'alumnat dintre del seu procés d'aprenentatge.This thesis belongs to the field of Mathematical Didactics (education, learning). We analyse the learning process of the secondary education student in relation to the study of functions with the use of spreadsheets as a work tool with a constructive methodologist model directed to manipulation and visualization. There are two focuses: as an innovation work and as a research work. As an innovation work we design and construct a learning sequence about functions and we create a teaching unit. Therefore, first of all we have prepared a teaching unit thought to study the functions using the spreadsheets at 4th level of obligatory secondary education (ESO in Spanish abbreviation). The students are 15 years old. The study of the functions goes towards the identification of the graphic behaviour of a straight line and a parabola according to the variations of its parameters and to recognize its characteristics across different algebraic situations that have been generated by affine and quadratic function. Secondly, we prepared a new teaching unit thought for Humanities «Bachillerato» (Spanish high school). The students are 16 to 18 years old. The purpose is to find and to recognize the functions, the graphics and the characteristics of the functions from the algebraic expression of the function. The functions studied are exponential, logarithmic, polynomial and rational functions. In the two last functions are applied derivates. As a research, firstly, we have analysed the student learning process in relation to the contents worked on the function subject, computer tool (spreadsheets), methodology used, the teaching unit and the student's attitude. Secondly, we have improved the teaching unit that constitutes a part of the learning curriculum. We have concreted these objectives in: a) to revise, in constructive process, the designed teaching unit and to elaborate a new proposal, b) to value how the spreadsheets affects the student's learning process, c) to revise the work methodology developed in the didactic innovation in the study of the functions using the spreadsheets for manipulation and visualization, d) to concrete the student's attitude within their learning process. Taking into account the objectives above mentioned the stages of our research design are: stage of elaboration, empiric stage and conclusive stage. The first is the stage of elaboration of the teaching unit; the second is the empiric stage, and finally, the conclusive stage where, at the end of every school year at every studied level, we analyse all the information collected during the process development and finally, we draw the conclusions

Fast, reliable and unrestricted iterative computation of Gauss-Hermite and Gauss-Laguerre quadratures

Methods for the computation of classical Gaussian quadrature rules are described which are effective both for small and large degree. These methods are reliable because the iterative computation of the nodes has guaranteed convergence, and they are fast due to their fourth-order convergence and its asymptotic exactness for an appropriate selection of the variables. For Gauss?Hermite and Gauss?Laguerre quadratures, local Taylor series can be used for computing efficiently the orthogonal polynomials involved, with exact initial values for the Hermite case and first values computed with a continued fraction for the Laguerre case. The resulting algorithms have almost unrestricted validity with respect to the parameters. Full relative precision is reached for the Hermite nodes, without any accuracy loss and for any degree, and a mild accuracy loss occurs for the Hermite and Laguerre weights as well as for the Laguerre nodes. These fast methods are exclusively based on convergent processes, which, together with the high order of convergence of the underlying iterative method, makes them particularly useful for high accuracy computations. We show examples of very high accuracy computations (of up to 1000 digits of accuracy)

Asymptotic inversion of the binomial and negative binomial cumulative distribution functions

ABSTRACT: The computation and inversion of the binomial and negative binomial cumulative distribution functions play a key role in many applications. In this paper, we explain how methods used for the central beta distribution function (described in Gil, Segura, and Temme, [Numer. Algorithms, 74 (2017), pp. 77?91]) can be utilized to obtain asymptotic representations of these functions and also for their inversion. The performance of the asymptotic inversion methods is illustrated with numerical examples.Acknowledgments. The authors thank the anonymous referees for their constructive comments and suggestions. This work was supported by Ministerio de Ciencia e Innovación, Spain, projects MTM2015-67142-P (MINECO/FEDER, UE) and PGC2018-098279-B-I00 (MCIU/AEI/FEDER, UE). NMT thanks CWI, Amsterdam, for scientific support

Singular Temperatures Connected to Charge Transport Mechanism Transitions in Perylene Bisimides from Steady-State Photocurrent Measurements

Perylene bisimides (PBIs) are n-type semiconducting and photogenerating materials widely used in a variety of optoelectronic devices. Particularly interesting are PBIs that are simultaneously water-soluble and liquid-crystalline (PBI-W+LC) and, thus, attractive for the development of high-performing easily processable applications in biology and “green” organic electronics. In this work, singular temperatures connected to charge transport mechanism transitions in a PBI-W+LC derivative are determined with high accuracy by means of temperature-dependent photocurrent studies. These singular temperatures include not only the ones observed at 60 and 110 °C, corresponding to phase transition temperatures from crystalline to liquid-crystalline (LC) and from LC to the isotropic phase, respectively, as confirmed by differential scanning calorimetry (DSC), but also a transition at 45 °C, not observed by DSC. By analyzing the photocurrent dependence simultaneously on temperature and on light intensity, this transition is interpreted as a change from monomolecular to bimolecular recombination. These results might be useful for other semiconducting photogenerating materials, not necessarily PBIs or even organic semiconductors, which also show transport behavior changes at singular temperatures not connected with structural or phase transitions.We appreciate support from the Spanish government (MINECO) and the European Community (FEDER) through Grant MAT-2011-28167-C02-01, as well as the University of Alicante. We gratefully acknowledge financial support from MINECO (MAT2014-52305-P) and the UCM-BSCH joint project (GR3/14-910759). A. de la Peña thanks Universidad Complutense for a predoctoral fellowship

Panniculitis – A Rare Manifestation of Acute Pancreatitis

AbstractPancreatic panniculitis is a rare skin disorder that occurs in 2–3% of pancreatic diseases, mostly associated with acute or chronic pancreatitis. Its pathophysiology is still unclear, but the release of pancreatic enzymes in circulation can be responsible for this disorder. The typical histological features are adipocyte necrosis with neutrophils infiltrate and typical “ghost cells”. Its treatment, clinical course and prognosis are usually related with the pancreatic disease.We present a case of a 39-year-old man who presented with fever, abdominal pain, nausea and vomiting after a copious alcohol ingestion. Acute alcohol-induced pancreatitis was diagnosed. 9 days after admission he developed tender erythematous subcutaneous nodules, whose biopsy was consistent with pancreatic panniculitis. There was clinical and laboratory improvement with supportive treatment as well as skin nodules regression.Although pancreatic panniculitis is a rare condition, physicians must be aware of it to avoid delay in the diagnosis

Late presentation of human T-lymphotropic virus type 1 infection in Spain reflects suboptimal testing strategies

Diagnosis; Myelopathy; Sexually transmitted infectionsDiagnóstico; Mielopatía; Infecciones de transmisión sexualDiagnòstic; Mielopatia; Infeccions de transmissió sexualObjectives Although only 10% of persons infected with human T-lymphotropic virus type 1 (HTLV-1) may develop virus-associated illnesses over their lifetime, missing the earlier diagnosis of asymptomatic carriers frequently leads to late presentation. Methods A nationwide HTLV-1 register was created in Spain in 1989. We examined the main demographics and clinical features at the time of the first diagnosis for more than three decades. Results A total of 428 individuals infected with HTLV-1 had been reported in Spain until the end of 2021. Up to 96 (22%) individuals presented clinically with HTLV-1-associated conditions, including subacute myelopathy (57%), T-cell lymphoma (34%), or Strongyloides stercoralis infestation (8%). Since 2008, HTLV-1 diagnosis has been made at blood banks (44%) or clinics (56%). Native Spaniards and Sub-Saharan Africans are overrepresented among patients presenting with HTLV-1-associated illnesses suggesting that poor epidemiological and/or clinical suspicion, which led to the late presentation are more frequent in them than carriers from Latin America (LATAM) (31.7% vs 20.4%, respectively; P = 0.015). Conclusion HTLV-1 infection in Spain is frequently diagnosed in patients presenting with characteristic illnesses. Although screening in blood banks mostly identifies asymptomatic carriers from LATAM, a disproportionately high number of Spaniards and Africans are diagnosed too late at the time of clinical manifestations. Expanding testing to all pregnant women and clinics for sexually transmitted infections could help to unveil HTLV-1 asymptomatic carriers.This work was supported in part by grants from FIS-ISCIII PI-21/1717 and Fundación Mutua Madrileña AP-174112020