Prevalence, distribution and evolutionary significance of the IS629 insertion element in the stepwise emergence of Escherichia coli O157:H7

<p>Abstract</p> <p>Background</p> <p>Insertion elements (IS) are known to play an important role in the evolution and genomic diversification of <it>Escherichia coli </it>O157:H7 lineages. In particular, IS<it>629 </it>has been found in multiple copies in the <it>E. coli </it>O157:H7 genome and is one of the most prevalent IS in this serotype. It was recently shown that the lack of O157 antigen expression in two O rough <it>E. coli </it>O157:H7 strains was due to IS<it>629 </it>insertions at 2 different locations in the <it>gne </it>gene that is essential for the O antigen biosynthesis.</p> <p>Results</p> <p>The comparison of 4 <it>E. coli </it>O157:H7 genome and plasmid sequences showed numerous IS<it>629 </it>insertion sites, although not uniformly distributed among strains. Comparison of IS<it>629</it>s found in O157:H7 and O55:H7 showed the presence of at least three different IS<it>629 </it>sub-types. O157:H7 strains carry IS<it>629 </it>elements sub-type I and III whereby the ancestral O55:H7 carries sub-type II. Analysis of strains selected from various clonal groups defined on the <it>E. coli </it>O157:H7 stepwise evolution model showed that IS<it>629 </it>was not observed in sorbitol fermenting O157 (SFO157) clones that are on a divergent pathway in the emergence of O157:H7. This suggests that the absence of IS<it>629 </it>in SFO157 strains probably occurred during the divergence of this lineage, albeit it remains uncertain if it contributed, in part, to their divergence from other closely related strains.</p> <p>Conclusions</p> <p>The highly variable genomic locations of IS<it>629 </it>in O157:H7 strains of the A6 clonal complex indicates that this insertion element probably played an important role in genome plasticity and in the divergence of O157:H7 lineages.</p

Effectiveness of Clinical Diagnosis in Lesions by HPV in Mouth. Useful Clinical Criteria

Infection by human papilloma virus (hpv) in the mouth is associated with lesions as multifocal epithelial hyperplasia (meh), verruca vulgaris (vv) and condyloma acuminatum (ca). In this study, the effectiveness of clinical diagnosis in lesions caused by hpv in mouth was evaluated, and useful clinical criteria for its diagnosis were proposed. The results suggest, that the clinical evaluation does not allow to differentiate the lesions. Age and the presence of multiple lesions were the clinical variables found for the diagnosis of meh. In the case of vv, female gender and unique pediculate lesions 7.65mm, and for the ca, age and male gender. Although, these variables might be insufficient in some cases, they contribute to the development of a dentistry based on evidence

Effectiveness of Toki's criteria and determination of variables for identification of HPV L1 protein in oral lesions

Objectives: To evaluate the effectiveness of Toki’s criteria in identifying the HPV L1 protein in oral lesions with the use of immunohistochemistry (IHC) and to determine which criteria optimize such identification. Study Design: Retrospective study of 277 cases diagnosed as HPV lesions at 22 years. Tests of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), kappa coefficients, and chi2 values, as well as two logistic regression analyses (p≤0.05), were conducted. Results: Of the lesions studied, 96.4% (267 of 277) were positive for HPV using Toki’s criteria and 28.5% (79 of 277) were positive for L1 by IHC. Toki’s criteria showed sensitivity=93.67%, specificity=2.53%, PPV=6.99%, and NPV=46.55%. Neither concordance nor statistically significant associations were observed between both tests. The logistic regression of Toki’s criteria was useful in the diagnosis of L1, correctly classified 71.8% of the lesions positive for L1, and showed a Hosmer-Lemeshow adjustment of p=0.614 and a Nagelkerke’s coefficient of determination of 6.8%. The explanatory variables statistically significant at p≤0.05 were dyskeratosis (p=0.01) and papillomatosis (p=0.04). Forty-nine independent variables (clinical and histopathologic) were involved in the second regression analysis. The model correctly classified 85.2% of the lesions and showed a Hosmer-Lemeshow adjustment of p=0.696 and a Nagelkerke’s coefficient of determination of 60.2%. The explanatory variables statistically significant atp≤0.05 were: age younger than 35 years (p=0.001), multiple lesions (p=0.031), hyperorthokeratosis (p=0.019), focal intracellular edema (p=0.002), and the presence of 1 to more than 5 cells with degenerative changes in their nucleus (p=0.048). Conclusions: Toki’s criteria are not adequate to make a diagnosis of lesions by HPV in the mouth, but the logistic regression analysis showed clinical and histopathologic variables which optimize the identification of lesions through the L1 protein. However, a PCR study is advisable when the presence of high-risk HPV is suspected

Relación de los hábitos de estudio y estilos de aprendizaje con el rendimiento académico en estudiantes de propedéutico de Chapingo

The aim of this study was to relate learning styles (LS) and study habits (SH) to academic performance (AP) for propaedeutic students from the Chapingo Autonomous University. To obtain this information, we applied two methods: the Honey-Alonso learning style questionnaire (HALSQ) and the study habits and techniques questionnaire (SHTQ). The sampling included 142 propaedeutic students, from whom we obtained their course grades. The answers to the questionnaire on SH and the LS were analyzed using the Kruskal-Wallis test and the correlation between the different ratings was evaluated. During the first semester, those who stated they had moderate habits achieved the lowest grade (77), and those with good and excellent habits attained similar grades (81.5-81.7). During the first semester, students with very good LS achieved the lowest grade (79). Among students with active LS, no correlation was observed with grades. We conclude that the correlation of study habits and learning styles with academic performance among propaedeutic students at Chapingo Autonomous University was very limited and in many cases there was no significance.El objetivo del estudio fue relacionar los estilos de aprendizaje (EA) y hábitos de estudios (HE) con el rendimiento académico (RA) de los estudiantes de propedéutico de la Universidad Autónoma Chapingo. Para obtener la información se utilizaron dos instrumentos, el cuestionario de Honey-Alonso de estilos de aprendizaje (CHAEA) y el cuestionario de hábitos y técnicas de estudio (CHTE). El muestreo consideró a 142 estudiantes de propedéutico, de los que se obtuvieron las calificaciones de sus materias cursadas. Las respuestas del cuestionario sobre los HE y de los EA se analizaron mediante la prueba de Kruskal-Wallis y se evaluó la correlación entre las diferentes escalas. Durante el primer semestre, quienes manifestaron tener hábitos moderados tuvieron la menor calificación (77), y los de buenos y excelentes hábitos tuvieron similar calificación (81.5-81.7). Durante el primer semestre los estudiantes con muy altos EA tuvieron la menor calificación (79). En los estudiantes con EA activo no se observó correlación con las calificaciones. Se concluye que la correlación de los hábitos de estudio y los estilos de aprendizaje con el rendimiento académico en estudiantes de propedéutico de la Universidad Autónoma Chapingo fue muy baja y en muchos casos no existió significancia

Design, construction and study of the efficiency of green panels with a monitoring system for physical variables

de un grupo de variables dentro de un prototipo a escala de un panel verde, las variables seleccionadas fueron; temperatura, humedad relativa, humedad del substrato, cantidad de luz, vibraciones mecánicas y telúricas, para luego estudiar el comportamiento de las variables mencionadas anteriormente. Para preparar el sistema para capturar y adquirir los datos y almacenarlos, se construyó un complejo electrónico que comprenda diversos sensores electrónicos acoplados a una tarjeta de hardware libre para elaborar prototipos denominada “Arduino Uno” y que mandara los datos a un ordenador vía alámbrica (cable USB) y creaba hojas de cálculo en Microsoft Excel, con un intervalo de tiempo definido por código abierto, creando inmensas bases de datos, después de 44 días de monitorización, para posteriormente, sus cifras fueran procesadas mediante software “R studio” de código de fuentes abiertas, obteniendo las medidas de tendencia central, gráficas, histogramas, curvas de densidad y se demostraron las relaciones entre variables con el coeficiente (R) de correlación se obtuvo mediante el método “Pearson”. El estudio de series de tiempo se logró desarrollar mediante ecuaciones lineales y no lineales; y se efectuó mediante el método de mínimos cuadrados y el método GARCH, corriendo una regresión simple que incluyó términos cuadráticos, logarítmicos, primeras diferencias, variables “dummy” o falsas y constantes, en este caso el software de elección fue E views, secundariamente Minitab, SPSS, SAS y STATA. Al terminar el análisis de regresión lineal, se obtuvieron resultados que confirmaron la eficiencia de los paneles verdes en el prototipo que se construyó, dando resultados que reforzaban la hipótesis del experimento, demostrando que las cubiertas vegetales instaladas en edificios reducen hasta en 8 °C la temperatura atmosférica y la humedad relativa del viento se potencializa hasta en 15 % más que en un edificio común y la disminución del efecto “Isla de Calor Urbana” por área verde determinada.The present work had some challenges such as to design and then construct an electronic system for monitoring the values of a select group of physical variables in a prototype of a green panel, the selected variables were temperature, relative humidity, soil humidity, mechanic and telluric vibrations and quantity of light, then study their behaviors of these variables mentioned before. To get the system ready for data acquisition and saving the data, it became necessary the construction of an electronically arrangement that understands; Open Source code, diverse types of electronic sensors and a free hardware device named “Arduino Uno board”. The prototype of a green panel in which we installed the electronic system with sensors that recorded the changes in an automatic way, then they were sent to a computer connected to the system with an USB wire for capturing data in Microsoft Excel, with an interval defined by Open Source Code, constructing a database, after 44 days of monitoring, for processing the data we occupied the software “R studio” of Open Source for continuing the study with a statistical analysis giving the central tendency measures, graphs, histograms, density curves and proving the correlation between variables with correlation coefficient (R) obtained by “Pearson” methodology. The study of time series and for developing linear and non-linear equations were done with the least squares’ methodology and GARCH method, running a simple regression, that included: logarithmic terms, quadratic terms, first differences, “dummies” and constants, in this case the statistical suites of choice were primarily E views, secondarily Minitab, SPSS, SAS and STATA. At the end of the regression, the results were in favor for the implementation of green panels in buildings, because they can bring several benefits to the environment. The conclusion was that the experiment generated atmospheric conditions that reduced in 8 °C of atmospheric temperature and the relative humidity in air is augmented in 15% and reduces carbon dioxide and carbon monoxide and the diminution of the “Urban Heat Island” effect in weather for a determined green area.SIEA UAME

Evaluacion economica centro acuiturismo en la comuna de Longavi, VII Region

132 p.En este estudio se realizo una evaluación económica de la instalación de un centro de acuiturismo en el sector precordillerano Los Canelos de la comuna de Longavi, ubicada en la Región del Maule. Este proyecto contempla la producción de 41 ton anuales de trucha arcoiris (oncorynchus mykiss), de las cuales 33 ton netas aprox., serán comercializadas congeladas con un tamaño porción de 200-250 grs. de peso unitario, y la prestación de servicios turísticos como son acceso a cabañas, camping, visitas a la piscicultura, caminatas por los alrededores, pesca deportiva, entre otros. Se realizo una caracterización del entorno en que se desarrolla el proyecto a nivel regional y comunal, que mostró que existen buenas posibilidades para invertir, en especial por la riqueza de los recursos naturales disponibles para el turismo y aprovechables para el desarrollo de una actividad productiva como es la salmonicultura. Una vez determinados ingresos y costos para cada periodo de tiempo, el flujo de caja proyectado para 10 anos se descontó a una tasa del 10,77% determinada en base al modelo de valoración de activos de capital, CAPM, utilizando retornos accionarios de la empresa de la industria salmonera Mainstream Salmones y Alimentos S.A. Con estos datos fue posible aplicar los criterios de VAN y TIR para obtener la verdadera rentabilidad del proyecto. Los resultados demostraron que el proyecto es rentable para un precio de venta del producto trucha de US $5,6/kilo con una TIR de 21,9%; no así para niveles inferiores de precio en los que no es aconsejable invertir puesto que no se recupera la inversión

Incidencia de trastornos mentales en Guinea Bissau de febrero - julio 2007.

This research was performed considering as universe the amount of patients treated at the Psychiatric practice belonging to the Reference Center of Mental Health at the Hospital ¨August 3th¨; we worked with the casuistry of February to July, 2007, taking the clinical and sociodemographic variables such as: classification of mental disorders supported by the ICD-10, age group, gender, procedence and type of ethnicity that they had practiced. The percentage distribution by sex was similar, a predominance of organic mental disorders, schizophrenia and other due to the use of psychoactive substances, mainly in the region of the Autonomous Sector of Bissau, the age groups of youth and adulthood prevailed, emphasizing the Fula, Balanta and Mandingo ethnic groups. The source of information was the book of statistical record of the Health Center. The data processing was supported in the percentage descriptive statistics.La investigación se realizó tomando como universo el total de pacientes atendidos en la consulta de Psiquiatría del Centro de Referencia de Salud Mental del Hospital 3 de Agosto, se trabajó con la casuística de febrero a julio del 2007 tomando variables clínicas y sociodemográficas como: clasificación del tipo de trastornos mentales apoyados en el CIE 10, grupos de edades, sexo, región de procedencia y tipo de etnia que practicaban. La distribución porcentual según sexo fue semejante, predominio de los trastornos mentales orgánicos, esquizofrenia y otros trastornos psicóticos y debido al consumo de sustancias psicoactivas, mayoritariamente de la región del Sector Autónomo de Bissau, predominaron los grupos de edades enmarcados en la juventud y adultez, destacándose las etnias fula, balanta y mandinga. La fuente de información fue el libro de registro estadístico del Centro de Salud. El procesamiento de los datos fue apoyado en la estadística descriptiva porcentual