Evolutionary algorithms guided by Erdos-Rényi complex networks.

This article proposes an evolutionary algorithm integrating Erdos-Rényi complex networks to regulate population crossovers, enhancing candidate solution refinement across generations. In this context, the population is conceptualized as a set of interrelated solutions, resembling a complex network. The algorithm enhances solutions by introducing new connections between them, thereby influencing population dynamics and optimizing the problem-solving process. The study conducts experiments comparing four instances of the traditional optimization problem known as the Traveling Salesman Problem (TSP). These experiments employ the traditional evolutionary algorithm, alternative algorithms utilizing different types of complex networks, and the proposed algorithm. The findings suggest that the approach guided by an Erdos-Rényi dynamic network surpasses the performance of the other algorithms. The proposed model exhibits improved convergence rates and shorter execution times. Thus, strategies based on complex networks reveal that network characteristics provide valuable information for solving optimization problems. Therefore, complex networks can regulate the decision-making process, similar to optimizing problems. This work emphasizes that the network structure is crucial in adding value to decision-making.

Early prediction of student performance in CS1 programming courses.

There is a high failure rate and low academic performance observed in programming courses. To address these issues, it is crucial to predict student performance at an early stage. This allows teachers to provide timely support and interventions to help students achieve their learning objectives. The prediction of student performance has gained significant attention, with researchers focusing on machine learning features and algorithms to improve predictions. This article proposes a model for predicting student performance in a 16-week CS1 programming course, specifically in weeks 3, 5, and 7. The model utilizes three key factors: grades, delivery time, and the number of attempts made by students in programming labs and an exam. Eight classification algorithms were employed to train and evaluate the model, with performance assessed using metrics such as accuracy, recall, F1 score, and AUC. In week 3, the gradient boosting classifier (GBC) achieved the best results with an F1 score of 86%, followed closely by the random forest classifier (RFC) with 83%. These findings demonstrate the potential of the proposed model in accurately predicting student performance.

Predicting the final grade using a machine learning regression model: insights from fifty percent of total course grades in CS1 courses.

This article introduces a model for accurately predicting students' final grades in the CS1 course by utilizing their grades from the first half of the course. The methodology includes three phases: training, testing, and validation, employing four regression algorithms: AdaBoost, Random Forest, Support Vector Regression (SVR), and XGBoost. Notably, the SVR algorithm outperformed the others, achieving an impressive R-squared (R2) value ranging from 72% to 91%. The discussion section focuses on four crucial aspects: the selection of data features and the percentage of course grades used for training, the comparison between predicted and actual values to demonstrate reliability, and the model's performance compared to existing literature models, highlighting its effectiveness.

Fístula aorto-atrial derecha: una presentación inusual / Aorta-to-right atrium fistula: an unusual presentation

Resumen Las fístulas aorto-atriales son anomalías anatómicas poco comunes, de etiología multifactorial; la causa más frecuente en la población adulta son las infecciones endocárdicas. Puede manifestarse como falla cardíaca, pasando por hipertensión pulmonar, hasta ser asintomática y precipitarse por algún evento estresante. El método diagnóstico de elección es la ecocardiografía, que según su localización pudiera ser mejor la modalidad, transtorácica o transesofágica. Se han descrito reparaciones endovasculares y quirúrgicas de las fístulas; esta última técnica es la más utilizada porque, como se indicó, la etiología más frecuente son los procesos infecciosos endomiocárdicos.

Abstract Aorta-to-atrium fistulas are rare anatomical anomalies, of a multifactorial aetiology. The most common cause in the adult population is due to endocardial infections. They can present as cardiac failure, ranging from pulmonary hypertension to being asymptomatic, and being precipitated by any stressful event. The diagnostic method of choice is echocardiography, and depending on its location, the transthoracic or trans-oesophageal mode would be better. Endovascular and surgical repairs of the fistulas have been described. This latter technique is the most used because, as previously mentioned, the most common origin is an endomyocardial infection.

Biotea: semantics for Pubmed Central.

A significant portion of biomedical literature is represented in a manner that makes it difficult for consumers to find or aggregate content through a computational query. One approach to facilitate reuse of the scientific literature is to structure this information as linked data using standardized web technologies. In this paper we present the second version of Biotea, a semantic, linked data version of the open-access subset of PubMed Central that has been enhanced with specialized annotation pipelines that uses existing infrastructure from the National Center for Biomedical Ontology. We expose our models, services, software and datasets. Our infrastructure enables manual and semi-automatic annotation, resulting data are represented as RDF-based linked data and can be readily queried using the SPARQL query language. We illustrate the utility of our system with several use cases. Our datasets, methods and techniques are available at http://biotea.github.io.

Prediction of virus-host protein-protein interactions mediated by short linear motifs.

BACKGROUND: Short linear motifs in host organisms proteins can be mimicked by viruses to create protein-protein interactions that disable or control metabolic pathways. Given that viral linear motif instances of host motif regular expressions can be found by chance, it is necessary to develop filtering methods of functional linear motifs. We conduct a systematic comparison of linear motifs filtering methods to develop a computational approach for predicting motif-mediated protein-protein interactions between human and the human immunodeficiency virus 1 (HIV-1). RESULTS: We implemented three filtering methods to obtain linear motif sets: 1) conserved in viral proteins (C), 2) located in disordered regions (D) and 3) rare or scarce in a set of randomized viral sequences (R). The sets C,D,R are united and intersected. The resulting sets are compared by the number of protein-protein interactions correctly inferred with them - with experimental validation. The comparison is done with HIV-1 sequences and interactions from the National Institute of Allergy and Infectious Diseases (NIAID). The number of correctly inferred interactions allows to rank the interactions by the sets used to deduce them: D∪R and C. The ordering of the sets is descending on the probability of capturing functional interactions. With respect to HIV-1, the sets C∪R, D∪R, C∪D∪R infer all known interactions between HIV1 and human proteins mediated by linear motifs. We found that the majority of conserved linear motifs in the virus are located in disordered regions. CONCLUSION: We have developed a method for predicting protein-protein interactions mediated by linear motifs between HIV-1 and human proteins. The method only use protein sequences as inputs. We can extend the software developed to any other eukaryotic virus and host in order to find and rank candidate interactions. In future works we will use it to explore possible viral attack mechanisms based on linear motif mimicry.

Tratamiento quirúrgico de la endocarditis infecciosa / Surgical treatment of infective endocarditis

Objetivo: describir las características epidemiológicas y los resultados del tratamiento quirúrgico temprano de los pacientes con diagnóstico de endocarditis infecciosa intervenidos en el Departamento de Cirugía Cardiovascular de la Clínica Medellín, Colombia. Métodos: estudio observacional, descriptivo, retrospectivo, de todos los pacientes con diagnóstico de endocarditis infecciosa tratados mediante cirugía en la Clínica Medellín, entre enero de 2003 y enero de 2010. Resultados: se incluyeron en total 54 pacientes, 37 (68,5%) de ellos de género masculino. La mediana de la edad fue 57,5 años (9 - 76 años). El 77,7% tenía algún factor de riesgo para desarrollar endocarditis infecciosa; entre los más destacados insuficiencia renal crónica (IRC) en hemodiálisis (18,5%) y prótesis valvulares cardiacas (18,5%). El 66,7% de los hemocultivos fue positivo. Staphylococcus aureus fue el principal germen aislado en el 40,7% del total de pacientes. El 81,4% de las válvulas comprometidas eran nativas con predominio de la válvula mitral (44,5%) y el 7,5% presentaba compromiso de dos válvulas. En el 68,5% el motivo de consulta fue falla cardiaca y 35,3% presentaron fenómenos embólicos como manifestación inicial o asociada (cerebral 16,7%, pulmonar 13%, esplénica 5,6%). En el 83,3% de los casos se realizó cirugía temprana; 66% recibieron válvulas mecánicas. La mortalidad total a tres meses fue del 13% (muerte intraoperatoria 3,7%, mortalidad a 30 días, 9%). La mediana en el tiempo de estancia hospitalaria fue de 36 días (7 a 130 días). En este estudio se reporta una mortalidad total que se encuentra en el límite inferior de lo reportado en el mundo. Una de las razones atribuibles a este hallazgo es el manejo quirúrgico temprano que se protocoliza en el servicio.

Objective: to describe the epidemiological characteristics and the results of early surgical treatment of patients diagnosed with infectious endocarditis who underwent surgery in the Department of Cardiovascular Surgery in the Medellin Clinic, Colombia. Methods: observational, descriptive, retrospective study of all the patients diagnosed with infective endocarditis treated by surgery in the Medellin Clinic between January 2003 and January 2010. Results: a total of 54 patients were included. 37 (68.5%) were male. Mean age was 57.5 years (9-76 years). 77.7% had a risk factor for developing infective endocarditis; among the most prominent risk factors were chronic renal failure (CRF), patients on hemodialysis (18.5%) and heart valve prostheses (18.5%). 66.7% of the blood cultures were positive. Staphylococcus aureus was the main germ isolated in 40.7% of patients. 81.4% of the involved valves were native, with mitral valve predominance (44.5%) and 7.5% had involvement of two valves. In 68.5% the reason for the consultation was heart failure and 35.3% had embolic phenomena as the initial manifestation or associated (16.7% cerebral, pulmonary 13%, spleen 5.6%). In 83.3 % of cases early surgery was performed: 66% received mechanical valves. The three-month total mortality was 13% (3.7% intraoperative death, mortality at 30 days 9%). The median length of hospital stay was 36 days (7-130 days). In this study the total mortality reported is at the lower limit of the reported in the world. One of the reasons attributed to this finding is the early surgical management that is the protocol in the service.

Tratamiento quirúrgico en el manejo de los defectos del septum atrial / Surgical treatment in the management of atrial septal defects

Objetivo: describir las características epidemiológicas y los resultados del tratamiento quirúrgico de los defectos septales atriales en los pacientes intervenidos por esta patología en un centro de alta complejidad en Colombia. Métodos: estudio observacional de tipo descriptivo, retrospectivo, de una cohorte que incluye todos los pacientes intervenidos mediante cirugía por defectos septales atriales en el periodo comprendido entre octubre de 1996 y julio de 2012. Resultados: se incluyeron en total 329 pacientes, de los cuales 216 (65,6%) pertenecía al género femenino. La mediana de la edad fue de 34 años (RIC 15-49). El 77,8% de los defectos fueron tipo ostium secundum. En 80% se realizó reparo del defecto mediante parche de pericardio autólogo. En 7,6% de los casos se utilizó técnica de cirugía cardiaca mínimamente invasiva. Se realizaron cuatro cirugías de rescate (1,21%) por complicaciones relacionadas con la colocación de dispositivos percutáneos. Se documentó una sola muerte intraoperatoria (tasa de mortalidad del 0,3%) y una morbilidad global asociada de 7,6%, sin ninguna secuela y representada por: reintervención por sangrado en ocho casos (2,4%), infección profunda de la herida esternal en tres pacientes (0,9%), empiema en tres pacientes (0,9%), colecciones pleurales residuales en cuatro pacientes (1,2%), infecciones superficiales en cinco pacientes (1,5%), disección arterial femoral secundaria a canulación arterial en un paciente (0,3%) y bloqueo cardiaco completo con necesidad de marcapaso permanente en un paciente (0,3%). La mediana del tiempo de estancia en UCI fue de 24 horas (RIC 20 – 25). La mediana del tiempo de ventilación mecánica fue de 3 horas (RIC 0-5). La mediana del tiempo de estancia hospitalaria fue de 4 días (RIC 3-5). Conclusiones: los resultados obtenidos reflejan que en nuestro medio la corrección quirúrgica de los defectos septales atriales es segura y efectiva, con una tasa de mortalidad con tendencia al 0% y una muy baja morbilidad asociada, acorde con los estándares internacionales. De igual forma, la cirugía cardiaca mínimamente invasiva ha permitido mejorar los resultados del procedimiento y ha tenido gran aceptación por parte de los pacientes, por lo que constituye el abordaje de elección actual para el manejo quirúrgico de esta patología en el servicio de Cardiología de la institución.

Objective: to describe the epidemiological characteristics and outcomes of surgical treatment of atrial septal defects in patients operated for this condition on a tertiary care center in Colombia. Methods: an observational, descriptive, retrospective study of a cohort including all patients undergoing surgery for atrial septal defects in the period between October 1996 and July 2012. Results: we included a total of 329 patients, were 216 (65.6%) were female. The mean age was 34 years (IQR 15-49). 77.8% of the defects were ostium secundum type. In 80% the defect repair was performed using autologous pericardial patch. In 7.6% of cases we used minimally invasive cardiac surgery technique. Four rescue surgeries (1.21%) were performed due to complications related to the placement of percutaneous devices. We documented only one operative death (mortality rate 0.3%) and an associated overall morbidity of 7.6% without any sequelae and represented by re-operation for bleeding in eight cases (2.4%), deep sternal wound infection in three patients (0.9%), empyema in three patients (0.9%), residual pleural collections in four patients (1.2%), superficial infections in five patients (1.5%), femoral arterial dissection secondary to arterial cannulation in one patient (0.3%) and complete heart block requiring permanent pacemaker in one patient (0.3%). The median length of stay in ICU was 24 hours (IQR 20-25). The median duration of mechanical ventilation was 3 hours (IQR 0-5). The median hospital stay was 4 days (IQR 3-5). Conclusions: the results obtained show that in our environment, surgical correction of atrial septal defects is safe and effective, with a mortality rate tending to 0% and a very low associated morbidity, in line with international standards. Similarly, minimally invasive cardiac surgery has improved the results of the procedure and has been widely accepted by the patients, thus constituting the current preferred approach in the Cardiology service of the institution for the surgical management of this pathology.