Extending the SACOC algorithm through the Nystrom method for dense manifold data analysis

Data analysis has become an important field over the last decades. The growing amount of data demands new analytical methodologies in order to extract relevant knowledge. Clustering is one of the most competitive techniques in this context.Using a dataset as a starting point, these techniques aim to blindly group the data by similarity. Among the different areas, manifold identification is currently gaining importance. Spectral-based methods, which are the mostly used methodologies in this area, are however sensitive to metric parameters and noise. In order to solve these problems, new bio-inspired techniques have been combined with different heuristics to perform the clustering solutions and stability, specially for dense datasets. Ant Colony Optimization (ACO) is one of these new bio-inspired methodologies. This paper presents an extension of a previous algorithm named Spectral-based ACO Clustering (SACOC). SACOC is a spectral-based clustering methodology used for manifold identification. This work is focused on improving this algorithm through the Nystrom extension. The new algorithm, named SACON, is able to deal with Dense Data problems.We have evaluated the performance of this new approach comparing it with online clustering algorithms and the Nystrom extension of the Spectral Clustering algorithm using several datasets

Medoid-based clustering using ant colony optimization

The application of ACO-based algorithms in data mining has been growing over the last few years, and several supervised and unsupervised learning algorithms have been developed using this bio-inspired approach. Most recent works about unsupervised learning have focused on clustering, showing the potential of ACO-based techniques. However, there are still clustering areas that are almost unexplored using these techniques, such as medoid-based clustering. Medoid-based clustering methods are helpful—compared to classical centroid-based techniques—when centroids cannot be easily defined. This paper proposes two medoid-based ACO clustering algorithms, where the only information needed is the distance between data: one algorithm that uses an ACO procedure to determine an optimal medoid set (METACOC algorithm) and another algorithm that uses an automatic selection of the number of clusters (METACOC-K algorithm). The proposed algorithms are compared against classical clustering approaches using synthetic and real-world datasets

Extending the SACOC algorithm through the Nystrom method for Dense Manifold Data Analysis

Data analysis has become an important field over the last decades. The growing amount of data demands new analytical methodologies in order to extract relevant knowledge. Clustering is one of the most competitive techniques in this context. Using a dataset as a starting point, clustering techniques aim to blindly group the data by similarity. Among the different areas, manifold identification is currently gaining importance. Spectral-based methods, which are one of the main used methodologies in this area, are sensitive to metric parameters and noise. In order to solve these problems, new bio-inspired techniques have been combined with different heuristics to perform the cluster selection, in particular for dense datasets. Dense datasets are featured by areas of higher density, where there are significantly more data instances than in the rest of the search space. This paper presents an extension of a previous algorithm named Spectral-based Ant Colony Optimization Clustering (SACOC), a spectral-based clustering methodology used for manifold identification. This work focuses on improving the SACOC algorithm through the Nystrom extension in order to deal with dense data problems. We evaluated the performance of the proposed approach, called SACON, comparing it against online clustering algorithms and the Nystrom extension of the Spectral Clustering algorithm using several benchmark datasets

Awareness, treatment and control of hypertension: Trend from population-based surveys conducted in a low-middle income country

Aim: To estimate and determine temporal trends for awareness, treatment and control of hypertension in adults from the urban area in Colombia. Methods: We conducted two population-based surveys (years 2010 and 2015) in the Metropolitan Area of Bucaramanga-Santander, Colombia, using the WHO STEPwise approach. Participants were asked to provide demographic, socioeconomic and cardiovascular risk factors data. Blood pressure (BP) was measured twice using an automated device. Hypertension was defined as a systolic BP≥140 mmHg, a diastolic BP≥90 mmHg or self-reported antihypertensive treatment. We estimated age, sex, and socioeconomic status (SES) adjusted prevalence ratios (PR), with 2010 as the reference survey, using poisson regression and correcting standard errors by clustering. Results: We evaluated 1,136 (mean age: 35.7 years; 43% male) and 872 (mean age:37.7 years; 41% male) adults from the 2010 and 2015 surveys, respectively. There were a larger proportion of individuals sampled from low SES in the 2015 as compared to the 2010 survey (93.6% vs. 70.9%). Overall, prevalence of hypertension was 16.4% (95%CI: 14.8 – 17.9): It increased significantly with age (from 2.4% among individuals 15-19 years old to 41.1% among individuals 50 years and older; p-trend<0.001) but did not differed by sex (17.8% in men vs. 15.4% in women) or year (16.1% vs. 16.6% in 2010 and 2015, respectively). Overall, prevalence of awareness, treatment and control of hypertension were 65.0%, 84.1%, and 62.2%, respectively. Although awareness and control increased from 2010 to 2015 (PR=1.05 and PR=1.12, respectively), only the prevalence of treatment showed a statistically significant increment of 11% (PR=1.11; 95%IC: 1.01 – 1.24). Implication: The STEPwise is a suitable surveillance strategy to estimate the burden of cardiovascular risk factors in low-middle income countries. Our results are consistent with national data from urban areas and show for the first time a short-time improvement in antihypertensive coverage

Live lecture screencast recording: a proposal to simplify the tasks associated with content production for video-teaching

Se trata de un resumen (Abstract) de la contribución. El acuerdo de transferencia de copyright del trabajo completo es incompatible con el depósito del mismo en RIUMA.Se describe la implementación inicial de un método simplificado de grabación en directo de sesiones de clase en asignaturas de las Escuelas de Ingeniería de la Universidad de Málaga. La simplificación se logra al incorporar en la actividad diaria del aula ciertas características típicas de la grabación en diferido de mini videos docentes. En una configuración mínima se graba únicamente el audio y el video en pantalla de la clase, evitando los desafíos técnicos y las dificultades que implica la grabación de otros elementos como la pizarra. Esto implica el uso de anotaciones en pantalla en tiempo real para reemplazar completamente las anotaciones en la pizarra.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. I Plan Propio Integral de Docencia. Universidad de Málaga. Universidad de Málaga. Vicerectorado de Personal Docente e Investigador, Proyectos de Innovación Educativa (PIE 17-018

High sporulation and overexpression of virulence factors in biofilms and reduced susceptibility to vancomycin and linezolid in recurrent Clostridium [Clostridioides] difficile infection isolates

Clostridium [Clostridioides] difficile infection (CDI) is one of the leading causes of diarrhea associated with medical care worldwide, and up to 60% of patients with CDI can develop a recurrent infection (R-CDI). A multi-species microbiota biofilm model of C. difficile was designed to evaluate the differences in the production of biofilms, sporulation, susceptibility to drugs, expression of sporulating (sigH, spo0A), quorum sensing (agrD1, and luxS), and adhesion-associated (slpA and cwp84) pathway genes between selected C. difficile isolates from R-CDI and non-recurrent patients (NR-CDI). We obtained 102 C. difficile isolates from 254 patients with confirmed CDI (66 from NR-CDI and 36 from R-CDI). Most of the isolates were biofilm producers, and most of the strains were ribotype 027 (81.374%, 83/102). Most C. difficile isolates were producers of biofilm (100/102), and most were strongly adherent. Sporulation was higher in the R-CDI than in the NR-CDI isolates (p = 0.015). The isolates from R-CDI patients more frequently demonstrated reduced susceptibility to vancomycin than isolates of NR-CDI patients (27.78% [10/36] and 9.09% [6/66], respectively, p = 0.013). The minimum inhibitory concentrations for vancomycin and linezolid against biofilms (BMIC) were up to 100 times and 20 times higher, respectively, than the corresponding planktonic MICs. Expression of sigH, spo0A, cwp84, and agrD1 was higher in R-CDI than in NR-CDI isolates. Most of the C. difficile isolates were producers of biofilms with no correlation with the ribotype. Sporulation was greater in R-CDI than in NR-CDI isolates in the biofilm model of C. difficile. The R-CDI isolates more frequently demonstrated reduced susceptibility to vancomycin and linezolid than the NR-CDI isolates in both planktonic cells and biofilm isolates. A higher expression of sporulating pathway (sigH, spo0A), quorum sensing (agrD1), and adhesion-associated (cwp84) genes was found in R-CDI than in NR-CDI isolates. All of these factors can have effect on the recurrence of the infection.Peer reviewe

Circulation of Highly Drug-Resistant Clostridium difficile Ribotypes 027 and 001 in Two Tertiary-Care Hospitals in Mexico

© 2018, Mary Ann Liebert, Inc.OBJECTIVE: To assess drug susceptibility and characterize Clostridium difficile ribotypes in isolates from two tertiary-care hospitals in Mexico. METHODS: Isolates were evaluated for genotyping, antimicrobial susceptibility testing and detection of mutations associated with drug resistance. PCR ribotyping was performed using a combination of gel-based and capillary electrophoresis-based approaches. RESULTS: MIC50 and MIC90 were ≥128 mg/L for ciprofloxacin, erythromycin, clindamycin, and rifampicin. There was no reduced susceptibility to metronidazole or tetracycline; however, reduced susceptibility to vancomycin (≥4 mg/L) and fidaxomicin (≥2 mg/L) was detected in 50 (40.3%) and 4 (3.2%) isolates, respectively. Furthermore, the rpoB Arg505Lys mutation was more frequently detected in isolates with high minimum inhibitory concentration (MIC) to rifampicin (≥32 mg/L) (OR = 52.5; 95% CI = 5.17-532.6; p < 0.000). Of the 124 C. difficile isolates recovered, 84 (66.7%) were of ribotype 027, 18 (14.5%) of ribotype 001, and the remainder were other ribotypes (353, 255, 220, 208, 176, 106, 076, 020, 019, 017, 014, 012, 003, and 002). CONCLUSION: Ribotypes 027 and 001 were the most frequent C. difficile isolates recovered in this study, and demonstrated higher MICs. Furthermore, we found four isolates with reduced susceptibility to fidaxomicin, raising a concern since this drug is currently unavailable in Mexican Hospitals.Peer reviewedFinal Accepted Versio

Assessment of cognitive performance among Mexican children and adolescents afflicted by simple to complex congenital heart diseases. Preliminary study

Among patients afflicted by congenital heart diseases (CHD) diverse, and complex neurological alterations are commonly observed. These have neither been completely identified nor understood. With the aim of identifying specific neurocognitive alterations among children and adolescents afflicted by CHD we investigated the possible presence of cognitive disorders related to the presence of cardiovascular disease with the aid of a sample of 20 patients (12 teenagers and 8 school-age children). Taken altogether, 9 of them were afflicted by simple and 11 by complex pathologies (respectively, CHDs/c). The Neuropsychological Test for Memory and Attention (Neuropsi), standardized for Mexico by Ostrosky et al. (2004), was individually applied to all participants. The information of cognitive performance was obtained in relation to the categories attention and memory, and the same areas allowed us to assess global performance. CHDc subjects performed significantly poorer compared to CHDs in i) attention and executive function, ii) memory and iii) attention and memory. Likewise, among CHDc subjects a significantly higher proportion of cases were diagnosed as abnormal in the same variables. Also a significant and negative correlation was determined between CHD severity and neuropsychological scoring. Children and adolescents afflicted by CHD are at high risk of developing cognitive function alterations including aspects of memory, attention and executive functions, alterations which are likely to be worst among those cases carrying CHDc conditions

Continuous ultrafiltration during extracorporeal circulation and its effect on lactatemia: A randomized controlled trial

Introduction. Hyperlactatemia occurs during or after extracorporeal circulation in the form of lactic acidosis, increasing the risk of postoperative complications and the mortality rate. The aim of this study was to evaluate whether continuous high-volume hemofiltration with volume replacement through a polyethersulfone filter during the extracorporeal circulation procedure decreases postoperative lactatemia and its consequences. ||Materials and methods. This was a randomized controlled trial. Patients were randomly divided into two groups of 32: with or without continuous high-volume hemofiltration through a polyethersulfone membrane. Five patients were excluded from each group during the study period. The sociodemographic characteristics, filter effects, and blood lactate levels at different times during the procedure were evaluated. Secondary endpoints were studied, such as the reduction in the intubation time and time spent in ICU. ||Results. Lactatemia measurements performed during the preoperative and intraoperative phases were not significantly different between the two groups. However, the blood lactate levels in the postoperative period and at 24 hours in the intensive care unit showed a significant reduction and a possible clinical benefit in the hemofiltered group. Following extracorporeal circulation, the mean lactate level was higher (difference: 0.77 mmol/L; CI 0.95: 0.01–1.53) in the nonhemofiltered group than in the hemofiltered group (p<0.05). This effect was greater at 24 hours (p = 0.019) in the nonhemofiltered group (difference: 1.06 mmol/L; CI 0.95: 0.18–1.93) than in the hemofiltered group. The reduction of lactatemia is associated with a reduction of inflammatory mediators and intubation time, with an improvement in liver function. || Conclusions. The use and control of continuous high-volume hemofiltration through a polyethersulfone membrane during heart-lung surgery could potencially prevent postoperative complications. The reduction of lactatemia implied a reduction in intubation time, a decrease in morbidity and mortality in the intensive care unit and a shorter hospital stay.14 páginas

Microemprendimientos, asociatividad y gestión de organizaciones sociales

The paper aims to present progress of the Project “promotion, development and strengthening solidarity organizations in the departments of Atlántico, Bolivar and Magdalena” , specifically South Atlantic , on general aspects of the production units or micro in the policy framework public . Likewise, partnerships as key element in the current dynamics of the economy and its relationship with micro-emprendimientos, from creating solidarity economy organizations and the challenge of managing them. Itpresents reflections on the connection between the theoretical and the general characteristics that distinguish this type of venture. The progress of the project and the theoretical review show that these microenterprises have major limitations to be sustainable and profitable. Moreover, individualism and distrust are obstacles to associativity. Added to that, when achieved associative processes formally and create solidarity economy organizations present a problem: their management. Because peoplelack the skills to do it. Through public policy has promoted the strengthening of small units , but large gap still exists between the dynamics of these and operation of public policy.Este artículo tiene como propósito presentar avances del proyecto titulado “Promoción, desarrollo y fortalecimiento a organizaciones solidarias de los departamentos del Atlántico, Bolívar y Magdalena”; específicamente sur del Atlántico, sobre aspectos generales de las unidades productivas o micro-emprendimientos en el marco de la política pública. Así mismo, la asociatividad como elemento clave en la dinámica actual de la economía y su relación con los micro-emprendimientos, a partir de la creación de organizaciones de economía solidaria y el reto que implica gestionarlas. Se reflexiona sobre la conexión entre los planteamientos teóricos y las características generales que distinguen este tipo de emprendimientos. Los avances del proyecto y la revisión teórica evidencian que estos microemprendimientos tienen grandes limitaciones para ser sostenibles y rentables. Además, el individualismo y desconfianza son obstáculos para la asociatividad. Sumado a ello, cuando se logran los procesos de asociatividad de manera formal y se crean organizaciones de economía solidaria se presenta una problemática: su gestión. Porque las personas carecen de la competencias necesarias para realizarlo. A través de la política pública se ha impulsado el fortalecimiento de las pequeñas unidades; pero aún existe gran brecha entre la dinámica de estas y la operatividad de la política pública