Papers by francisco Lopez
Revista Venezolana De Oncologia, Dec 1, 2009
The breast cancer represents a public health problem. The breast cancer is entities which increas... more The breast cancer represents a public health problem. The breast cancer is entities which increase his incidence in the world. These problem do to a creation...
El arrendamiento financiero, mas conocido como leasing comenzo a introducirse en Espana a finales... more El arrendamiento financiero, mas conocido como leasing comenzo a introducirse en Espana a finales de la decada de los anos 50 del siglo pasado. En 2005, ultimos datos disponibles, mas de una cuarta parte de la totalidad de las inversiones realizadas por los empresarios y profesionales espanoles de todos los sectores se financio mediante leasing. Sin embargo, todavia esta muy por debajo de la presencia que tiene en la UE. La existencia del leasing facilita el que muchas empresas y emprendedores (en Espana el 80% de la inversion nueva financiada con leasing corresponde a las pymes) encuentren la financiacion de la que, en su ausencia, podrian carecer, o que, al menos, la encuentren en condiciones mas ventajosas. Ello estimula la inversion a largo plazo y el crecimiento de la economia. Con el objeto de poner en perspectiva y clarificar las relaciones entre tres grandes cuestiones de evidente relevancia para el progreso de una economia avanzada: la importancia de la inversion a largo plazo, el papel del leasing como instrumento de financiacion de dicha inversion a largo plazo y los efectos leasing en la economia espanola, y de dar unas conclusiones y recomendaciones, la Asociacion Espanola de Leasing (AEL) encomendo a Analistas Financieros Internacionales (AFI), el estudio que conforma esta edicion.
La Semana Vitivinicola, 2000
Journal of the American College of Cardiology, 2015
Background: When evaluating syncope in a young pregnant patient, the most likely causes include p... more Background: When evaluating syncope in a young pregnant patient, the most likely causes include pulmonary embolism (PE) and cardiac arrhythmia. We present an unusual cause of syncope masquerading as PE. case: A 26 year old female, 14 weeks pregnant, presented with dyspnea, chest discomfort and syncope. On examination, she was hypotensive and tachycardic. A contrasted computed tomography (CT) of the chest showed a large filling defect in the proximal PA trunk presumed to be PE. Upon transfer to a tertiary care center, a transthoracic echocardiography (TTE) demonstrated a dilated right ventricle (RV) and a mass in the proximal PA, inconsistent with thrombus, causing hemodynamically significant obstruction. Cardiac magnetic resonance (CMR) imaging was then performed. decision Making: CMR showed a well-circumscribed, heterogeneous cystic mass causing critical obstruction of the proximal PA. RV remodelling suggested slow growth of the cyst and chronic RV pressure overload. The patient underwent urgent surgical excision of the mass and pathology reported a proteinacious cyst, wall composition indicating valvular origin. An increased gradient across the mass due to pregnancy related hemodynamic changes and/or acute enlargement of the cyst (area of hemorrhage noted) explained her presentation. conclusion: CMR is the gold standard for assessment of cardiac masses and was essential in characterizing the cyst. In this case, an extremely rare proteinaceous cyst was correctly diagnosed and treated.
Lecture Notes in Computer Science, 2004
Segmentation is an essential part of practically any automated image recognition system, since it... more Segmentation is an essential part of practically any automated image recognition system, since it is necessary for further processing such as feature extraction or object recognition. There exist a variety of techniques for threshold selection, as it is a fast, simple and robust method. Threshold value will have considerable effects on the boundary position and overall size of the extracted objects. In this work, we propose an automated thresholding selection, which takes into account the local properties of a pixel. To do this, the algorithm calculates the morphological gradient and Laplacian and, afterwards, chooses a suitable threshold after estimating the lowest distance between the ideal segmentation and the morphological gradient thresholding segmentation.
Clinical cancer research : an official journal of the American Association for Cancer Research, 2003
Signet ring cell colorectal carcinoma (SRCCC) represents a unique, infrequent, and highly maligna... more Signet ring cell colorectal carcinoma (SRCCC) represents a unique, infrequent, and highly malignant variant of colorectal cancer. To understand the pathogenesis of SRCCC, we investigated its molecular abnormalities and compared them with those of the usual type of colorectal adenocarcinoma. Microdissected archival paraffin-embedded tissue from 16 SRCCCs and 27 non-SRCCCs was used to determine the frequency and pattern of mutation at codons 12, 13, and 61 of K-ras. A subset of tumors was examined for TP53 mutations at exons 5-8 and allele loss and genetic instability using seven microsatellite and two mononucleotide markers. Comparable data on TP53 mutation, allele loss, and microsatellite instability were found between SRCCC and non-SRCCC. However, SRCCCs demonstrated a distinct pattern of K-ras mutation with a significantly lower frequency of mutations at codons 12 and 13 (13% versus 48%, P = 0.02) as compared with the non-SRCCCs. Four cases (25%) of SRCCC demonstrated the same A:T...
Journal of the Chinese Institute of Industrial Engineers, 2008
In this paper, we propose a heuristic for the well-known single-level un-capacitated dynamic lot-... more In this paper, we propose a heuristic for the well-known single-level un-capacitated dynamic lot-sizing problem. The proposed heuristic is based on the average period cost criterion introduced by the heuristic from Silver and Meal (18), also known as Least Period Cost (LPC). Two desirable features of the proposed heuristic are simplicity and the heuristic's ability to complement LPC effectively. We
Journal of Institutional Economics, 2014
A growing literature in the fields of economics and political science has identified the importan... more A growing literature in the fields of economics and political science has identified the importance of culture for both economic development and good governance. In this article, we argue that a fundamental factor driving cultural traits conducive towards development and governance is inter-personal income inequality. Our empirical evidence from a cross-section of countries and based on measures of culture extracted from the World Values Survey, provides strong support for our argument even after controlling for the effect of an extensive range of potentially confounding variables and the possibility that our estimates may suffer from both measurement error and reverse causality.
Imaging and Applied Optics, 2011
This paper presents preliminary studies of RGB and HSV color spaces analysis for polarized light ... more This paper presents preliminary studies of RGB and HSV color spaces analysis for polarized light images of plastic films under tensile deformation. The results obtained show a tool for differentiating phenomena of deformation analyzing plastics
2011 IEEE Consumer Communications and Networking Conference (CCNC), 2011
ABSTRACT In this work the authors assess the main stakeholders involved in using Internet Protoco... more ABSTRACT In this work the authors assess the main stakeholders involved in using Internet Protocol Television (IPTV) from the perspective of how users can interact in a business model that will be mutually beneficial to all. Then, Social TV is well placed to leverage the benefits to both business players and end users in an advertising business model that will be summarized by authors using game theory techniques.
Neuroscience Research, 1995
There does not appear to be a consensus on the normal values of cerebrospinal fluid pressure (Pcs... more There does not appear to be a consensus on the normal values of cerebrospinal fluid pressure (Pcsf) in rats because of the different conditions in which each experiment has been done. Anaesthesia, restraint or recordings from different anatomical places and the use of simultaneous infusions could produce a great variability in the obtained results and because of that the average Pcsf in rats has been reported to be between 2 and about 18.5 cm H20. The aim of this study is to provide new information about the normal values of Pcsf in adult, conscious rats by carrying out long-term measurements, for 3 consecutive days, from different anatomical places. Thirty male Wistar rats divided in three experimental groups of ten animals each were used. A catheter of silicone was implanted into the lateral ventricles in group I, the cisterna magna in group II, and the lumbar subarachnoid space in group III to record the Pcsf values. This catheter was attached to a swivel system to allow unrestrained and free behaviour in the rats. Mean values of normal Pcsf values were 13.03.4-0.73 cm HeO from the lateral ventricles, 15.9 4-0.73 cm H20 from the cisterna magna, and 16.73.4-1.14 cm H20 from the lumbar subarachnoid space.
Medical Physics, 2000
Virtual Wedge (VW) is a Siemens treatment modality which generates wedge-shaped dose distribution... more Virtual Wedge (VW) is a Siemens treatment modality which generates wedge-shaped dose distributions by moving a collimator jaw from closed to open at a constant speed while varying the dose rate in every 2 mm jaw position. In this work, the implementation and verification of VW in a radiotherapy treatment planning (RTP) system is presented. The VW implementation models the dose delivered by VW using the Siemens monitor units (MU) analytic formalism which determines the number of MU required to generate a wedge-fluence profile at points across the VW beam. For any set of treatment parameters, the VW algorithm generates an "intensity map" that is used to model the modification of fluence emanating from the collimator. The intensity map is calculated as the ratio of MU delivered on an axis point, divided by the monitor units delivered on the central-axis MU(0). The dose calculation is then performed using either the Clarkson or Convolution/ Superposition algorithms. The VW implementation also models the operational constraints for the delivery of VW due to dose rate and jaw speed limits. Dose verifications with measured profiles were performed using both the Clarkson and Convolution/Superposition algorithms for three photon beams; Siemens Primus 6 and 23 MV, and Mevatron MD 15 MV. Agreement within 2% or 2 mm was found between calculated and measured doses, over a large set of test cases, for 15, 30, 45, and 60 degree symmetric and asymmetric VW fields, using the manufacturer's supplied mu and c values for each beam.
Journal of Insect Behavior, 1992
Page 1. Journal of Insect Behavior, Vol. 5, No. 3, 1992 The Problem of the Acts Duration Measurem... more Page 1. Journal of Insect Behavior, Vol. 5, No. 3, 1992 The Problem of the Acts Duration Measurement in Relation to the "Focal-Animal" Technique of Behavioral Recording Francisco J. Acosta, 1 Jose M. Serrano, 1 Jesus M. Barandica, 2 and Francisco Lopez ...
International Journal of Environmental Analytical Chemistry, 2007
ABSTRACT Liquid chromatography coupled to tandem mass spectrometry with a triple quadrupole analy... more ABSTRACT Liquid chromatography coupled to tandem mass spectrometry with a triple quadrupole analyser was used to determine selected (medium) polar organic pollutants—isoproturon, diuron and pentachlorophenol, as the herbicides simazine, atrazine, terbuthilazine, alachlor, and metolachlor—in treated water from urban solid-waste leachates. Two millilitres of water was preconcentrated by on-line trace enrichment (solid-phase extraction liquid chromatography) which allowed rapid analysis, but still with a satisfactory sensitivity, as the limits of quantification were 0.05 µg L, while the limits of detection were in the range of 0.001–0.01 µg L. Confirmation of the identity of compounds was ensured by the use of two tandem mass spectrometry transitions. Moreover, a study of matrix effects was thoroughly investigated by applying the developed procedure to different ground and surface waters. A simple dilution of the water sample with high-performance-liquid-chromatography-grade water was sufficient to minimize and/or remove this undesirable effect in all water samples tested, this approach being feasible due to the excellent sensitivity of the method.
International Journal of Environmental Analytical Chemistry, 1998
An experimental approach for pesticide mobility studies in the soil environment has been develope... more An experimental approach for pesticide mobility studies in the soil environment has been developed, based on three main aspects: 1) the development of analytical procedures suitable for unsaturated zone pesticide monitoring; 2) adsorption studies; 3) controlled application of pesticides to two experimental sites and subsequent analysis of soil and water samples. Four pesticides have been selected to perform this study:
Cancer, 2002
BACKGROUND. Telomerase is a ribonucleoprotein polymerase that adds telomeric repeats to chromosom... more BACKGROUND. Telomerase is a ribonucleoprotein polymerase that adds telomeric repeats to chromosome ends. This enzyme is deficient in the majority of normal somatic cells, but often is reactivated during tumorigenesis. In the current study, the authors examined telomerase activity in human American Joint Committee on Cancer Stage II colorectal carcinomas and correlated it with traditional prognostic indicators and disease outcome. METHODS. The telomerase repeat amplification protocol (TRAP) was employed to determine telomerase activity in 122 surgical specimens (from 77 male and 45 female patients) of human Stage II colorectal carcinoma. The primary site of the tumor was the colon in 52 cases and the rectum in 70 cases. Telomerase activity was correlated with traditional prognostic indicators such as gender, age, T classification, tumor size, tumor grade, and disease outcome (overall survival and disease-free survival). The Median follow-up for patients who still were alive was 5.8 years. RESULTS. Telomerase activity was detected in 80% of the tumors (98 of 122 tumors). Telomerase-positive patients differed from telomerase-negative patients in that they tended to be female (41% vs. 21%; P ϭ 0.1), presented with primary tumors of the colon more frequently (49% vs. 17%; P ϭ 0.01), and had a higher T classification (T 4) (62% vs. 38%; P ϭ 0.04). Univariate and multivariate analyses demonstrated a correlation between telomerase activity and disease-free survival (P ϭ 0.05). CONCLUSIONS. Although a large percentage of Stage II colorectal carcinoma samples were positive for telomerase activity, the prognosis for patients with telomerase-negative tumors was found to be worse than that for patients with telomerasepositive tumors. Cancer 2002;95:1834-9.
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Papers by francisco Lopez