An incremental learning approach to prediction models of SEIRD variables in the context of the COVID-19 pandemic.

Several works have proposed predictive models of the SEIRD (Susceptible, Exposed, Infected, Recovered, and Dead) variables to characterize the pandemic of COVID-19. One of the challenges of these models is to be able to follow the dynamics of the disease to make more precise predictions. In this paper, we propose an approach based on incremental learning to build predictive models of the SEIRD variables for the COVID-19 pandemic. Our incremental learning approach is a dynamic ensemble method based on a bagging scheme that allows the addition of new models or the updating of incremental models. The article proposes an incremental learning architecture composed of two components. The first component carries out an analysis of the interdependencies of the SEIRD variables and the second component is an incremental learning model that builds/updates the predictive models. The paper analyses the quality of the predictive models of our incremental learning approach using data of the COVID-19 from Colombia, and shows interesting results about the predictions of the SEIRD variables. These results are compared with an incremental learning approach based on random forests.

Anti-Biofouling and Desalination Properties of Thin Film Composite Reverse Osmosis Membranes Modified with Copper and Iron Nanoparticles.

The anti-biofouling and desalination properties of thin film composite reverse osmosis membranes (TFC-RO), modified by the incorporation of copper and iron nanoparticles, were compared. Nanoparticles of metallic copper (CuNPs) and an iron crystalline phase mix (Fe and Fe2O3, FeNPs) were obtained by oxide-reduction-precipitation and reduction reactions, respectively, and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. Modified membranes (PA+0.25Cu-PSL and PA+0.25Fe-PSL) were obtained by incorporating these nanoparticles during the interfacial polymerization process (PI). These membranes were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and contact angle measurements. Bactericidal tests by a Colony Forming Unit (CFU) were performed using Escherichia coli, and anti-adhesion properties were confirmed by fluorescence microscopy estimating the percentage of live/dead cells. The permeate flow and rejection of salts was evaluated using a crossflow cell. An increase of the membrane's roughness on the modified membrane was observed, influencing the desalination performance more strongly in the presence of the FeNPs with respect to the CuNPs. Moreover, a significant bactericidal and anti-adhesion effect was obtained in presence of both modifications with respect to the pristine membrane. An important decrease in CFU in the presence of modified membranes of around 98% in both modifications was observed. However, the anti-adhesion percentage and reduction of live/dead cells were higher in the presence of the copper-modified membrane in comparison to the iron-modified membrane. These facts were attributed to the differences in antimicrobial action mechanism of these types of nanoparticles. In conclusion, TFC-RO membranes modified by the incorporation of CuNPs during PI represent one alternative material to attend to the biofouling impact in the desalination process.

Liver lipocalin 2 expression in severely obese women with non alcoholic fatty liver disease.

BACKGROUND: Lipocalin 2 (LCN2) has been related to obesity, insulin resistance and metabolic disturbance. However, its relation with non alcoholic fatty liver disease (NAFLD) has hardly been studied. METHODS: We examined LCN2 circulating levels and its protein and gene expression in liver from women with severe obesity and NAFLD. We analyzed the liver histology of 59 white severely obese women (BMI ≥40 Kg/m²): 15 subjects presented normal liver histology or non-significant liver disease (NL), 18 simple steatosis (SS) and 26 non alcoholic steatohepatitis (NASH). We determined the anthropometric and metabolic features of the women. LCN2 levels were determined by an ELISA and liver mRNA expression by real time RT-PCR. We also studied LCN2 expression in HepG2 liver cells under various inflammatory stimuli. RESULTS: Liver LCN2 protein and gene expression were higher in NAFLD than in obese with NL. Liver LCN2 gene expression correlated with SS (r=0.351, p=0.016), and its protein expression correlated with NASH (r=0.705, p=0.003). LCN2 expression was detected in HepG2 cells after the administration of TNFα, IL6, resistin or adiponectin. LCN2 expression was induced by TNFα, IL6 and resistin. CONCLUSIONS: Liver LCN2 is related to NAFLD in severely obese women. Up-regulation of LCN2 expression is detected in HepG2 cells after exposure to TNFα, IL6 and resistin. These results suggest that LCN2 expression is induced under liver harmful conditions.

Quantification of the expression of reference and alcohol dehydrogenase genes of some acetic acid bacteria in different growth conditions.

AIMS: The aim of this study was to develop a reliable system to analyse the expression of the pyrroloquinoline quinone (PQQ)-alcohol dehydrogenase (ADH) and test its ability to predict the growth and oxidative activity of some acetic acid bacteria (AAB). METHODS AND RESULTS: Specific primers were designed for use in RT-PCR to quantify ADH expression and several housekeeping genes in four species of AAB. 16S rRNA gene was selected as an internal control. The relative expression of adhA was measured in Acetobacter aceti, Acetobacter pasteurianus, Gluconacetobacter hansenii and Gluconobacter oxydans grown in two media that had glucose or ethanol as the carbon source. AAB adhA expression was shown to be related to the two Acetobacter species' ability to oxidise and grow on ethanol, whereas G. oxydans were unable to grow on ethanol and the growth of Ga. hansenii was not related to adhA expression. CONCLUSIONS: The differential expression of ADH could be a marker to analyse both growth and oxidation ability in some AAB, especially those of the genus Acetobacter. SIGNIFICANCE AND IMPACT OF THE STUDY: Several housekeeping genes were tested in AAB and after growth in different media and it was evident that only the ribosomal coding genes were adequate as reference genes for RT-PCR.

Effect of awareness through movement on the head posture of bruxist children.

The aim of this study was to evaluate the effectiveness of physiotherapy to improve the head posture and reduce the signs of bruxism in a group of bruxist children. A single-blind randomized clinical trial was performed. All the subjects were 3- to 6-year old, had complete primary dentition, dental and skeletal class I occlusion and were classified as bruxist according to the minimal criteria of the ICSD for bruxism. For each child, a clinical, photographic and radiographic evaluation of the head and cervical posture were realized with standardized techniques. The children were randomized in an experimental (n = 13) and a control (n = 13) group. A physiotherapeutic intervention was applied to the children of the experimental group once a week, until 10 sessions were completed. Afterwards, the cephalogram and the clinical and photographic evaluation of the head posture were measured again. The data were analysed with the t-test and Mann-Whitney test. The subjects of the experimental group showed statistically significant improvement in the natural head posture. The physiotherapeutic intervention showed to be efficient to improve the head posture at the moment of measurement in the studied children. The relationship between bruxism and head posture, if exists, seems to be worthwhile to examine.

Anestesia regional para pilomatrixoma: manejo anestésico: a propósito de un caso / Pilomatrixoma for regional anesthesia: anesthetic management: a purpose of a case

El pilomatrixoma es un tumor que deriva de la matrix del folículo piloso. Usualmente se manifiesta como un nódulo firme, solitario y asintomático. Es considerado como un tumor raro. Aproximadamente el 50 por ciento de las lesiones se observan en cabeza y cuello. Se presenta en la mayoría de veces en niños, pero su presentación en adultos es altamente reportada. Es más común en mujeres que en hombres. Su tratamiento se basa en la resección quirúrgica. Múltiples pilomatrixomas se han observado en asociación con distrofias musculares. La técnica anestésica ideal es aquella que permite mantener una adecuada estabilidad hemodinámica intraoperatoria, sin embargo los procedimientos extra e intracraneanos, están asociados a importantes variaciones en los estímulos nociceptivos, debido a lo cual se requiere frecuentes ajuste de la profundidad anestésica, el bloqueo somático de cabeza y cuello, proporciona una forma optima de anestesia, sola o como complemento de anestesia general, y produce una analgesia excelente en el período postoperatorio. En nuestro centro asistencial es frecuente el uso de bloqueo de cuero cabelludo, en los pacientes neuroquirúrgicos, a continuación se describe el uso de anestesia regional en un paciente masculino, con pilomatrixoma, realizada en el Instituto Autónomo Hospital Universitario de Los Andes.

Larga duración de la respuesta inmunitaria celular inducida en lactantes y niños inmunizados con vacuna proteoliposómica antimeningocócica BC / Long-lasting cellular immune response in babies, children, and pre-teenagers vaccinated with a proteoliposome based anti-meningococcal BC vaccine

VA-MENGOC-BC® es una vacuna contra los sero grupos B y C de Neisseria meningitidis. La respuesta humoral ha sido extensivamente evaluada pero no la respuesta celular. Estudios prospectivos y retrospectivos fueron realizados para especificar la inducción y duración de la respuesta inmunitaria. El estudio prospectivo fue llevado a cabo en 62 lactantes usando un test de hipersensibilidad retardada (DTH) antes de la primera (3,5 meses de edad), junto a la segunda (42 días después) y 28 días después de la segunda dosis. En los lactantes, la DTH fue negativa antes y 100 por ciento positiva después de la vacunación. El estudio retrospectivo incluyó 535 niños que habían sido vacunados entre 2 y 7 años antes. La positividad de la DTH fue de 100 por ciento en todos los grupos. En los niños vacunados 5 ó 7 años antes, las técnicas de linfoproliferación (LP) y las células secretoras de anticuerpos (ASC) fueron también determinadas. La LP fue positiva en el 26 y 34 por ciento antes de la dosis de re fuerzo en los niños vacunados de 5 y 7 años, respectivamente y decreció posteriormente. Los ASC fueron negativos antes de la dosis de refuerzo y generalmente positivos 7 días después de ésta. No obstante, en los niños vacunados hacía 7 años el 12 por ciento tuvo una pequeña cantidad de ASC antes del refuerzo, los cuales pudieran estar relacionados con la alta frecuencia de circulación de Neisseria en la población o de microorganismos con reactividad cruzada. El mayor incremento en los ASC después del refuerzo (desde 0,73 hasta 166,24 x 106 PBMC) fue observado en aquellos negativos que tenían bajos números de ASC antes del refuerzo al compararlos con los totalmente negativos (desde 0 hasta 67,7 x 106 PBMC). Estos resultados muestran claramente la inducción de respuesta celular en lactantes, la persistencia de respuesta celular en los grupos vacunados hacía tiempo y la memoria de larga duración detectada por una tercera dosis (AU)

Nitric oxide participates in the immune response against Neisseria meningitidis serogroup B.

The present report explores the role of nitric oxide into the immune response against Neisseria meningitidis serogroup B. Here we show that NO mediates the alphaTNF increase induced by N. meningitidis derived lipopolysaccharides (LPS), at the same time that participates in the bactericidal activity of resting or gammaIFN activated macrophages and plays a role in the specific DTH and IgG response induced by a commercial anti-meningococcal vaccine. Our findings suggest a positive role for NO at the final effector mechanisms and in the early events driving the immunity against N. meningitidis, suggesting also an insight into its role in endotoxic shock.