Preparation and characterization of methacrylate hydrogels for zeta potential control

A technique based on the measurement of streaming potentials has been developed to evaluate the effects of hydrophilic coatings on electroosmotic flow. The apparatus and procedure are described as well as some results concerning the electrokinetic potential of glass capillaries as a function of ionic strength, pH, and temperature. The effect that turbulence and entrance flow conditions have on accurate streaming potential measurements is discussed. Various silane adhesion promoters exhibited only a slight decrease in streaming potential. A coating utilizing a glycidoxy silane base upon which methylcellulose is applied affords a six-fold decrease over uncoated tubes. Hydrophilic methacrylate gels show similar streaming potential behavior, independent of the water content of the gel. By introduction of positive or negative groups into the hydrophilic methacrylate gels, a range of streaming potential values are obtained having absolute positive or negative signs

Hydrodynamics: Fluctuating Initial Conditions and Two-particle Correlations

Event-by-event hydrodynamics (or hydrodynamics with fluctuating initial conditions) has been developed in the past few years. Here we discuss how it may help to understand the various structures observed in two-particle correlations.Comment: 7 pages, 9 figures, presented at the Workshop on Saturation, the Color Glass Condensate and Glasma: What Have we Learned from RHIC

Imaging the postoperative patient: long-term complications of gastrointestinal surgery

The objectives of this review are (1) to become acquainted with the long-term complications of surgery of the gastrointestinal tract, and (2) to appreciate the appropriate use of imaging in the assessment of long-term complications

Barreras percibidas y nivel de actividad física en adultos mayores de Aguascalientes, Ags.: Un estudio transversal

Introduction. Mexico is in demographic transition being more than 10% of its population older adults who have a high frequency of non-communicable diseases. The objective was to know the relationship between perceived barriers and physical activity level in older adults from Aguascalientes in Mexico. Material and methods. The present study is cross-sectional, analytic, and observational.150 older adults registered in the Family Integral Development System from Aguascalientes State were included at random, who accepted to participate by signing a consent form. A questionnaire to detect perceived barriers as well as an international physical activity questionnaire was applied. Statistical analysis. Z for two proportions, p-value and odds ratio, 95% confidence interval were calculated, between external and internal perceived barriers and low physical activity level in older adults from the sample. Results. In reference to the sample, 71.3% were between 60 and 70 years old; 72% were female, 78% had low physical activity level. The lack of information about physical activity benefits is a barrier in relation to low physical activity (Z=2.36, p=0.02, OR=2.97 95%CI=1.28 to 6.90); the lack of support from their family is another barrier in relation to their low physical activity (Z=2.91, p=0.003, OR=3.82, 95%CI=161 to 9.10); another barrier was the lack of places (such as health centers and gyms for older adults) to perform physical activity (Z=4.2, p<0.05, OR=5.8, 95%CI=2.5 to 13.3). Conclusion. The nursing designing programs to perform physical activity in older adults should take into account these perceived barriers.Introducción. México está en transición demográfica con más del 10% de su población, siendo adultos mayores, quienes tienen elevada prevalencia de enfermedades no transmisibles. El objetivo fue conocer la relación entre las barreras percibidas y el nivel de actividad física en adultos mayores de Aguascalientes, Ags.Materiales y métodos. Es un estudio transversal, observacional, analítico. 150 adultos mayores registrados en el Sistema de Desarrollo Integral Familiar de Aguascalientes, que firmaron el consentimiento, fueron incluidos. Se aplicaron los cuestionarios de barreras percibidas y el internacional de actividad física.Análisis estadístico. Z para dos proporciones, valor de p, Razón de Momios e intervalos de confianza al 95% fueron calculados, entre barreras percibidas externas e internas y el nivel de actividad física que realizaban los adultos mayores de la muestra.Resultados. La muestra estuvo integrada por adultos mayores con edad entre los 60 y 70 años; 72% fueron mujeres, 78% tenían bajo nivel de actividad física. La falta de información acerca de los beneficios de la actividad física es una barrera para tener mejor nivel de actividad física (Z=2.36, p=0.02, RM=2.97 IC95%=1.28 a 6.90); la falta de apoyo de las familias es otra barrera para la actividad física (Z=2.91, p=0.003, RM=3.82, IC95%=161 a 9.10); también fue una barrera la falta de espacios para realizar actividad física, tales como centros de salud y gimnasios para adultos mayores (Z=4.2, p<0.05, RM=5.8, IC95=2.5 a 13.3).Conclusión. El diseño de programas de enfermeríapara realizar actividad física en adultos mayores, deberán tomar en cuenta las barreras percibidas

Aeroallergens sensitization in an allergic paediatric population of Cova da Beira, Portugal.

Cova da Beira is an interior central region of Portugal, with a population of 93,000 inhabitants. The first pollen counts performed in Portugal revealed the highest values of the country in this area. The aim of this study was to assess the aeroallergens sensitization in an allergic population, according to the age groups. In a 5 year period (1995-2000) 1790 consecutive outpatients were observed for suspected allergic symptoms. We included in this study all the 557 paediatric (< or = 15 years old) observed patients (317 male (57%) and 240 female (43%) with an average age of 7.6 < or = 4.2 years old). They were divided in three age groups (Group I: < or = 5 yr; Group II: 6-10 yr; Group III: 11-15 yr). 371 patients were submitted to skin prick tests to aeroallergens. 86.5% of these patients were sensitised to at least one allergen extract. The most representative aeroallergens sensitization were grasses mixture (44.9%), D. pteronyssinus (32.5%), D. farinae (29.1%), Olea europea (27.5%), Parietaria judaica (23.4%), cat dander (16.1%), Artemisia vulgaris (17.6%), Robinia pseudoacacia (12.2%), Platanus acerifolia (11.4%), Tilia cordata (11.4%) moulds mixture (11.2%), Plantago lanceolata (10.6%), dog dander (10.4%), and Pinus radiata (7.5%). The sensitisation to indoor aeroallergens, was similar in all age groups and it was less important than that of pollens. The prevalence of sensitisation to grasses was the greatest in all ages and the house dust mites sensitization was the second most prevalent. The highest pollens counts in this region could explain the early sensitisation even in young children

Autoestima y consumo de alcohol en estudiantes de una preparatoria de la ciudad de Guanajuato

Propósito y Método de Estudio: el objetivo del estudio fue conocer la relación del autoestima con el consumo de alcohol en estudiantes de una preparatoria de la ciudad de Guanajuato, el diseño fue descriptivo y correlacional, el muestreo fue probabilístico estratificado con asignación proporcional al tamaño del estrato (grado escolar). Se obtuvo una muestra de 441 estudiantes, estimada para un 95% de nivel de confianza, considerando un enfoque conservador de .5 y un límite de error de estimación de .03. Se aplicó una Cédula de Datos Personales, un Cuestionario de Prevalencia de Consumo de Alcohol y la Escala de Autoestima de Rosenberg, la cual obtuvo un Alpha de Cronbach de .77. Contribuciones y Conclusiones: la media de edad fue 16.47 años (DE= .98), la edad de inicio de consumo de 10.93 años (DE= 5.73), los estudiantes en un día típico consumen en promedio 2.46 copas por ocasión. Se encontró una prevalencia global de consumo de alcohol de 79.8% (IC 95% .76 - .83), prevalencia anual de 62.6% (IC 95% .58 - .67), prevalencia actual de 39.5% (IC 95% .34 - .44) y prevalencia instantánea de 21.8% (IC 95% .17 - .25). Se presentó diferencia significativa de la prevalencia de consumo de alcohol actual (X2 =8.95,p = .003) y de la prevalencia instantánea (X2 = 6.39, p = .015) por sexo, los estudiantes del sexo masculino presentaron una proporción más alta (46.9%) de consumo de bebidas en un día típico que las mujeres (32.9%) en el último mes y últimos siete días. Los estudiantes de 16 años presentaron medias y medianas de consumo de copas en un día típico mayores en la prevalencia global ( X = 3.30, Mdn = 3.00), prevalencia actual ( X = 4.81, Mdn = 4.50) y prevalencia instantánea ( X = 4.91, Mdn = 4.50). No se encontró relación significativa del autoestima con el consumo de alcohol (p >.05)

An Efficient Local Search for Partial Latin Square Extension Problem

A partial Latin square (PLS) is a partial assignment of n symbols to an nxn grid such that, in each row and in each column, each symbol appears at most once. The partial Latin square extension problem is an NP-hard problem that asks for a largest extension of a given PLS. In this paper we propose an efficient local search for this problem. We focus on the local search such that the neighborhood is defined by (p,q)-swap, i.e., removing exactly p symbols and then assigning symbols to at most q empty cells. For p in {1,2,3}, our neighborhood search algorithm finds an improved solution or concludes that no such solution exists in O(n^{p+1}) time. We also propose a novel swap operation, Trellis-swap, which is a generalization of (1,q)-swap and (2,q)-swap. Our Trellis-neighborhood search algorithm takes O(n^{3.5}) time to do the same thing. Using these neighborhood search algorithms, we design a prototype iterated local search algorithm and show its effectiveness in comparison with state-of-the-art optimization solvers such as IBM ILOG CPLEX and LocalSolver.Comment: 17 pages, 2 figure

Highly Sensitive Detection of Individual HEAT and ARM Repeats with HHpred and COACH

BACKGROUND:HEAT and ARM repeats occur in a large number of eukaryotic proteins. As these repeats are often highly diverged, the prediction of HEAT or ARM domains can be challenging. Except for the most clear-cut cases, identification at the individual repeat level is indispensable, in particular for determining domain boundaries. However, methods using single sequence queries do not have the sensitivity required to deal with more divergent repeats and, when applied to proteins with known structures, in some cases failed to detect a single repeat. METHODOLOGY AND PRINCIPAL FINDINGS:Testing algorithms which use multiple sequence alignments as queries, we found two of them, HHpred and COACH, to detect HEAT and ARM repeats with greatly enhanced sensitivity. Calibration against experimentally determined structures suggests the use of three score classes with increasing confidence in the prediction, and prediction thresholds for each method. When we applied a new protocol using both HHpred and COACH to these structures, it detected 82% of HEAT repeats and 90% of ARM repeats, with the minimum for a given protein of 57% for HEAT repeats and 60% for ARM repeats. Application to bona fide HEAT and ARM proteins or domains indicated that similar numbers can be expected for the full complement of HEAT/ARM proteins. A systematic screen of the Protein Data Bank for false positive hits revealed their number to be low, in particular for ARM repeats. Double false positive hits for a given protein were rare for HEAT and not at all observed for ARM repeats. In combination with fold prediction and consistency checking (multiple sequence alignments, secondary structure prediction, and position analysis), repeat prediction with the new HHpred/COACH protocol dramatically improves prediction in the twilight zone of fold prediction methods, as well as the delineation of HEAT/ARM domain boundaries. SIGNIFICANCE:A protocol is presented for the identification of individual HEAT or ARM repeats which is straightforward to implement. It provides high sensitivity at a low false positive rate and will therefore greatly enhance the accuracy of predictions of HEAT and ARM domains