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Search Results: 1 - 10 of 85141 matches for " Carlos Fernando Ramos-Lopez "
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PhagoSight: An Open-Source MATLAB? Package for the Analysis of Fluorescent Neutrophil and Macrophage Migration in a Zebrafish Model
Katherine M. Henry, Luke Pase, Carlos Fernando Ramos-Lopez, Graham J. Lieschke, Stephen A. Renshaw, Constantino Carlos Reyes-Aldasoro
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0072636
Abstract: Neutrophil migration in zebrafish larvae is increasingly used as a model to study the response of these leukocytes to different determinants of the cellular inflammatory response. However, it remains challenging to extract comprehensive information describing the behaviour of neutrophils from the multi-dimensional data sets acquired with widefield or confocal microscopes. Here, we describe PhagoSight, an open-source software package for the segmentation, tracking and visualisation of migrating phagocytes in three dimensions. The algorithms in PhagoSight extract a large number of measurements that summarise the behaviour of neutrophils, but that could potentially be applied to any moving fluorescent cells. To derive a useful panel of variables quantifying aspects of neutrophil migratory behaviour, and to demonstrate the utility of PhagoSight, we evaluated changes in the volume of migrating neutrophils. Cell volume increased as neutrophils migrated towards the wound region of injured zebrafish. PhagoSight is openly available as MATLAB? m-files under the GNU General Public License. Synthetic data sets and a comprehensive user manual are available from http://www.phagosight.org.
An adaptive algorithm for the cornea modeling from keratometric data
Andrei Martinez-Finkelshtein,Dario Ramos-Lopez,Gracia M. Castro-Luna,Jorge L. Alio
Physics , 2010,
Abstract: In this paper we describe an adaptive and multi-scale algorithm for the parsimonious fit of the corneal surface data that allows to adapt the number of functions used in the reconstruction to the conditions of each cornea. The method implements also a dynamical selection of the parameters and the management of noise. It can be used for the real-time reconstruction of both altimetric data and corneal power maps from the data collected by keratoscopes, such as the Placido rings based topographers, decisive for an early detection of corneal diseases such as keratoconus. Numerical experiments show that the algorithm exhibits a steady exponential error decay, independently of the level of aberration of the cornea. The complexity of each anisotropic gaussian basis functions in the functional representation is the same, but their parameters vary to fit the current scale. This scale is determined only by the residual errors and not by the number of the iteration. Finally, the position and clustering of their centers, as well as the size of the shape parameters, provides an additional spatial information about the regions of higher irregularity. These results are compared with the standard approximation procedures based on the Zernike polynomials expansions.
Computation of 2D Fourier transforms and diffraction integrals using Gaussian radial basis functions
A. Martinez-Finkelshtein,D. Ramos-Lopez,D. R. Iskander
Mathematics , 2015,
Abstract: We implement an efficient method of computation of two dimensional Fourier-type integrals based on approximation of the integrand by Gaussian radial basis functions, which constitute a standard tool in approximation theory. As a result, we obtain a rapidly converging series expansion for the integrals, allowing for their accurate calculation. We apply this idea to the evaluation of diffraction integrals, used for the computation of the through-focus characteristics of an optical system. We implement this method and compare it performance in terms of complexity, accuracy and execution time with several alternative approaches, especially with the extended Nijboer-Zernike theory, which is also outlined in the text for the reader's convenience. The proposed method yields a reliable and fast scheme for simultaneous evaluation of such kind of integrals for several values of the defocus parameter, as required in the characterization of the through-focus optics.
Optimal sampling patterns for Zernike polynomials
D. Ramos-Lopez,M. A. Sanchez-Granero,M. Fernandez-Martinez,A. Martinez-Finkelshtein
Mathematics , 2015,
Abstract: A pattern of interpolation nodes on the disk is studied, for which the interpolation problem is theoretically unisolvent, and which renders a minimal numerical condition for the collocation matrix when the standard basis of Zernike polynomials is used. It is shown that these nodes have an excellent performance also from several alternative points of view, providing a numerically stable surface reconstruction, starting from both the elevation and the slope data. Sampling at these nodes allows for a more precise recovery of the coefficients in the Zernike expansion of a wavefront or of an optical surface.
Insulin gene polymorphisms in type 1 diabetes, Addison's disease and the polyglandular autoimmune syndrome type II
Elizabeth Ramos-Lopez, Britta Lange, Heinrich Kahles, Holger S Willenberg, Gesine Meyer, Marissa Penna-Martinez, Nicole Reisch, Stefanie Hahner, Jürgen Seissler, Klaus Badenhoop
BMC Medical Genetics , 2008, DOI: 10.1186/1471-2350-9-65
Abstract: We investigated the role of the -2221Msp(C/T) and -23HphI(A/T) polymorphisms within the insulin gene in patients with a monoglandular autoimmune endocrine disease [patients with isolated type 1 diabetes (T1D, n = 317), Addison's disease (AD, n = 107) or Hashimoto's thyroiditis (HT, n = 61)], those with a polyglandular autoimmune syndrome type II (combination of T1D and/or AD with HT or GD, n = 62) as well as in healthy controls (HC, n = 275).T1D patients carried significantly more often the homozygous genotype "CC" -2221Msp(C/T) and "AA" -23HphI(A/T) polymorphisms than the HC (78.5% vs. 66.2%, p = 0.0027 and 75.4% vs. 52.4%, p = 3.7 × 10-8, respectively).The distribution of insulin gene polymorphisms did not show significant differences between patients with AD, HT, or APS-II and HC.We demonstrate that the allele "C" of the -2221Msp(C/T) and "A" -23HphI(A/T) insulin gene polymorphisms confer susceptibility to T1D but not to isolated AD, HT or as a part of the APS-II.Type 1 diabetes (T1D) has a multifactorial pathogenesis, partly caused by environment but also by genetic predisposition. The association of the MHC class II genes with T1D is well known, but there are also non- MHC genes such as the insulin gene, that confer susceptibility to T1D [1].The insulin gene is transcribed upon binding of the transcription factor Pur1 to the promoter element, known as the variable number of tandem repeat (VNTR) region, located 596 bp upstream of the insulin gene translation initiation site. The VNTR region comprises variable 14–15 bp tandem repeat sequences with the consensus 5'-ACAGGGGTGTGGGG-3', also named the insulin gene minisatellite. In Caucasians there are two main classes of the VNTR region minisatellites named class I and class III alleles. The VNTR class I alleles, which are associated with increased susceptibility to T1D, comprise between 26 and 63 repeat units and are shorter than class III alleles (between 141 and 209 repeat units), associated with dominant protect
The rs1990760 polymorphism within the IFIH1 locus is not associated with Graves' disease, Hashimoto's thyroiditis and Addison's disease
Marissa Penna-Martinez, Elizabeth Ramos-Lopez, Inka Robbers, Heinrich Kahles, Stefanie Hahner, Holger Willenberg, Nicole Reisch, Christian Seidl, Maria Segni, Klaus Badenhoop
BMC Medical Genetics , 2009, DOI: 10.1186/1471-2350-10-126
Abstract: The aim of the present study was to investigate the role of the rs1990760 polymorphism within the IFIH1 gene in German patients with GD (n = 258), Hashimoto's thyroiditis (HT, n = 106), Addison's disease (AD, n = 195) and healthy controls (HC, n = 227) as well as in 55 GD families (165 individuals, German) and 100 HT families (300 individuals, Italian). Furthermore, the interaction between rs1990760 polymorphism with human leukocyte antigen (HLA) risk haplotype DQ2(DQA*0501-DQB*0201), the risk haplotypes DQ2/DQ8 (DQA*0301-DQB*0302) and the status of thyroglobulin antibody (TgAb), thyroid peroxidase antibody (TPOAb) and TSH receptor antibody (TRAb) in patients and families were analysed.No significant differences were found between the allele and genotype frequencies for rs1990760 IFIH1 polymorphism in patients with GD, HT, AD and HC. Also no differences were observed when stratifying the IFIH1 rs1990760 polymorphism for gender, presence or absence of thyroid antibodies (GD:TRAb and HT:TPOAb/TgAb) and HLA risk haplotypes (DQ2:for GD and HT, DQ2/DQ8:for AD). Furthermore the transmission analysis in GD and HT families revealed no differences in alleles transmission for rs1990760 IFIH1 from parents with or without HLA risk haplotype DQ2 to the affected offspring. In contrast, by dividing the HT parents according to the presence or absence of thyroid Ab titers, mothers and fathers both positive for TPOAb/TgAb overtransmitted the allele A of IFIH1 rs1990760 to their HT affected offspring (61.8% vs 38.2%;p = 0.05;corrected p [pc] = 0.1). However, these associations did not remain statistically significant after correction of the p-values.In conclusion, our data suggest, no contribution from IFIH1 rs1990760 polymorphism to the pathogenesis of either Graves' disease, Hashimoto's thyroiditis or Addison's disease in our study populations. However, in order to exclude a possible influence of the studied polymorphism in specified subgroups within patients with autoimmune thyroid
A WEB SERVICE FOR SIGNING AND AUTHENTICATING DIGITAL DOCUMENTS BASED ON SYMMETRIC CRYPTOGRAPHY PROTOCOL
Juan Carlos Lopez Pimentel,Victor Fernando Ramos Fon Bon,Raul Monroy
International Journal of Digital Information and Wireless Communications , 2011,
Abstract: Nowadays, recognizing whether or not a digital document has been counterfeit is a priority issue, particularly in organizations where legal information is handled digitally. Signing a digital document is maybe a preliminary solution. In general, we are interested in developing a web service that allows signing a document using cryptography and steganography techniques to protect the information; and also, it can verify the authenticity of the document that has previously been signed. To protect the web service against malicious activity there are aspects of computer security that must be considered, such as the implementation of a security protocol considered secure. This article reports the general ingredients to implement a Web Service to sign and authenticate digital documents using a symmetric cryptography protocol previously published by the authors; and also it describes some implementations carried out so far.
Ubiquitous Computing and Its Applications in the Disease Management in a Ubiquitous City  [PDF]
Javier Cabo Salvador, Jose Miguel Ramirez Uceda, Verónica Cabo Mui?os, Javier Ramos Lopez, Carlos de Castro
Journal of Computer and Communications (JCC) , 2018, DOI: 10.4236/jcc.2018.63002
Abstract: The actual challenge in health is to manage patients with chronic diseases from a holistic approach where technology around the patient and at the city enhances their wellness. This paper deepens in the relations between health, devices, and models of technological cities and how these can be modeled to provide a more cost efficient solution while less invasive and more natural to the end users. In light of this, usable and accessible software and a wide range of devices, ranging from PC, smartphone, tablet and SmartTV have been tested. This manuscript will give good comprehension on how technology and disease management care models interact with the patient.
FISim: A new similarity measure between transcription factor binding sites based on the fuzzy integral
Fernando Garcia, Francisco J Lopez, Carlos Cano, Armando Blanco
BMC Bioinformatics , 2009, DOI: 10.1186/1471-2105-10-224
Abstract: We propose FISim, a new similarity measure between PFMs, based on the fuzzy integral of the distance of the nucleotides with respect to the information content of the positions. Unlike existing methods, FISim is designed to consider the higher contribution of better conserved positions to the binding affinity. FISim provides excellent results when dealing with sets of randomly generated motifs, and outperforms the remaining methods when handling real datasets of related motifs. Furthermore, we propose a new cluster methodology based on kernel theory together with FISim to obtain groups of related motifs potentially bound by the same TFs, providing more robust results than existing approaches.FISim corrects a design flaw of the most popular methods, whose measures favour similarity of low information content positions. We use our measure to successfully identify motifs that describe binding sites for the same TF and to solve real-life problems. In this study the reliability of fuzzy technology for motif comparison tasks is proven.One of the main goals in computational biology is to understand how expression of genes is controlled, and to unravel gene regulatory networks. Cells control the abundance and activity of proteins by means of diverse factors in which transcription regulation plays a central role. Multiple events are involved in the initiation of transcription of a gene. One of the most important ones is the binding of several proteins, called transcription factors (TFs), to DNA near the gene, called transcription factor binding sites (TFBSs). TFBSs are usually located close to the transcription start site (TSS) of the gene and upstream from it. Additionally, in some cases TFBSs can be found downstream the TSS or, in rare instances, even within exons [1]. These interactions between DNA and proteins play a crucial role in controlling the expression of the genes by activating or inhibiting the transcriptional machinery.The identification of binding sites bound
Brugada electrocardiographic pattern induced by fever
Pablo Lamelas,Carlos Labadet,Fernando Spernanzoni,Cristian Lopez Saubidet
World Journal of Cardiology , 2012, DOI: 10.4330/wjc.v4.i3.84
Abstract: Brugada syndrome is a major cause of sudden death in young adults. Fever has been described to induce a Brugada-type electrocardiogram in asymptomatic patients with a negative family history, to disclose Brugada syndrome and to increase the risk of death and induce T wave alternans in patients with diagnosed Brugada syndrome. Risk stratification is challenging and demands a careful evaluation. Here we present 2 case reports and review the literature.
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