a backtracking search tool for constructing combinatorial test suites

Combinatorial testing is an important testing method. It requires the test cases to cover various combinations of parameters of the system under test. The test generation problem for combinatorial testing can be modeled as constructing a matrix which has certain properties. This paper first discusses two combinatorial testing criteria: covering array and orthogonal array, and then proposes a backtracking search algorithm to construct matrices satisfying them. Several search heuristics and symmetry breaking techniques are used to reduce the search time. This paper also introduces some techniques to generate large covering array instances from smaller ones. All the techniques have been implemented in a tool called EXACT (EXhaustive seArch of Combinatorial Test suites). A new optimal covering array is found by this tool.

Comparison of porcine urine and bile as matrices to screen for the residues of two sulfonamides using a semi-automated enzyme immunoassay.

Porcine urine enzyme immunoassays for sulfamethazine and sulfadiazine have previously been employed as screening tests to predict the concentrations of the drugs in the corresponding tissues (kidneys), If a urine was found positive (> 800 ng ml(-1)) the corresponding kidney was then analysed by an enzyme immunoassay and, if found positive, a confirmatory analysis by HPLC was performed. Urine was chosen as the screening matrix since sulfonamides are mainly eliminated through this body fluid, However, after obtaining a number of false positive predictions, an investigation was carried out to assess the possibility of using an alternative body fluid which would act as a superior indicator of the presence of sulfonamides in porcine kidney, An initial study indicated that serum, plasma and bile could all be used as screening matrices. From these, bile was chosen as the preferred sample matrix and an extensive study followed to compare the efficiencies of sulfonamide positive bile and urine at predicting sulphonamide positive kidneys, Bile was found to be 17 times more efficient than urine at predicting a sulfamethazine positive kidney and 11 times more efficient at predicting a sulfadiazine positive kidney, With this enhanced performance of the initial screening test, the need for the costly and time consuming kidney enzyme immunoassay, prior to HPLC analysis, was eliminated

Determination of thyreostat residues from bovine matrices using high-performance liquid chromatography

High-performance liquid chromatography (HPLC) methodologies were evaluated for the detection and quantification of thyreostatic drug residues in cattle serum and thyroid tissue. The paper details a protocol, using a simple ethyl acetate extraction for the determination of thiouracil, tapazole, methyl thiouracil, propyl thiouracil and phenyl thiouracil in thyroid tissue. Using two sequential HPLC injections, and quantitative analysis, in two steps, all five thyreostats were detectable at concentrations greater than 2.45-4.52 ng/g. Modifications to a published method for detection of thyreostatic residues in serum involving the addition of mercaptoethanol and a freezing step are described. The modifications improved sensitivity and allowed detection of the five thyreostats at levels greater than 16.98-35.25 ng/ml. Young bulls were treated with thyreostats to demonstrate the validity of the methodologies described. Administered thyreostats were not absorbed equally by the test animals and the compounds were not all detected in the serum samples removed at 7 days following drug withdrawal. These experiments indicate the necessity to be able to detect thyreostat residues in a variety of matrices. (C) 1998 Elsevier Science B.V. All rights reserved.

Test-retest variability in structural and functional parameters of glaucoma damage in the glaucoma imaging longitudinal study.

PURPOSE:

To determine the test-retest variability in perimetric, optic disc, and macular thickness parameters in a cohort of treated patients with established glaucoma.

PATIENTS AND METHODS:

In this cohort study, the authors analyzed the imaging studies and visual field tests at the baseline and 6-month visits of 162 eyes of 162 participant in the Glaucoma Imaging Longitudinal Study (GILS). They assessed the difference, expressed as the standard error of measurement, of Humphrey field analyzer II (HFA) Swedish Interactive Threshold Algorithm fast, Heidelberg retinal tomograph (HRT) II, and retinal thickness analyzer (RTA) parameters between the two visits and assumed that this difference was due to measurement variability, not pathologic change. A statistically significant change was defined as twice the standard error of measurement.

RESULTS:

In this cohort of treated glaucoma patients, it was found that statistically significant changes were 3.2 dB for mean deviation (MD), 2.2 for pattern standard deviation (PSD), 0.12 for cup shape measure, 0.26 mm for rim area, and 32.8 microm and 31.8 microm for superior and inferior macular thickness, respectively. On the basis of these values, it was estimated that the number of potential progression events detectable in this cohort by the parameters of MD, PSD, cup shape measure, rim area, superior macular thickness, and inferior macular thickness was 7.5, 6.0, 2.3, 5.7, 3.1, and 3.4, respectively.

CONCLUSIONS:

The variability of the measurements of MD, PSD, and rim area, relative to the range of possible values, is less than the variability of cup shape measure or macular thickness measurements. Therefore, the former measurements may be more useful global measurements for assessing progressive glaucoma damage.

Octopus Standard Automated Perimetry, Pulsar Perimetry, Moorfields Motion Displacement Test and Heidelberg Retinal Tomography in Glaucoma Detection - A Comparison of Diagnostic Accuracy

Purpose: To investigate the accuracy of 4 clinical instruments in the detection of glaucomatous damage. Methods: 102 eyes of 55 test subjects (Age mean = 66.5yrs, range = [39; 89]) underwent Heidelberg Retinal Tomography (HRTIII), (disc area<2.43); and standard automated perimetry (SAP) using Octopus (Dynamic); Pulsar (TOP); and Moorfields Motion Displacement Test (MDT) (ESTA strategy). Eyes were separated into three groups 1) Healthy (H): IOP<21mmHg and healthy discs (clinical examination), 39 subjects, 78 eyes; 2) Glaucoma suspect (GS): Suspicious discs (clinical examination), 12 subjects, 15 eyes; 3) Glaucoma (G): progressive structural or functional loss, 14 subjects, 20 eyes. Clinical diagnostic precision was examined using the cut-off associated with the p<5% normative limit of MD (Octopus/Pulsar), PTD (MDT) and MRA (HRT) analysis. The sensitivity, specificity and accuracy were calculated for each instrument. Results: See table Conclusions: Despite the advantage of defining glaucoma suspects using clinical optic disc examination, the HRT did not yield significantly higher accuracy than functional measures. HRT, MDT and Octopus SAP yielded higher accuracy than Pulsar perimetry, although results did not reach statistical significance. Further studies are required to investigate the structure-function correlations between these instruments.

Effects of selection and drift on G matrix evolution in a heterogeneous environment: a multivariate Qst-Fst Test with the freshwater snail Galba truncatula.

Unraveling the effect of selection vs. drift on the evolution of quantitative traits is commonly achieved by one of two methods. Either one contrasts population differentiation estimates for genetic markers and quantitative traits (the Q(st)-F(st) contrast) or multivariate methods are used to study the covariance between sets of traits. In particular, many studies have focused on the genetic variance-covariance matrix (the G matrix). However, both drift and selection can cause changes in G. To understand their joint effects, we recently combined the two methods into a single test (accompanying article by Martin et al.), which we apply here to a network of 16 natural populations of the freshwater snail Galba truncatula. Using this new neutrality test, extended to hierarchical population structures, we studied the multivariate equivalent of the Q(st)-F(st) contrast for several life-history traits of G. truncatula. We found strong evidence of selection acting on multivariate phenotypes. Selection was homogeneous among populations within each habitat and heterogeneous between habitats. We found that the G matrices were relatively stable within each habitat, with proportionality between the among-populations (D) and the within-populations (G) covariance matrices. The effect of habitat heterogeneity is to break this proportionality because of selection for habitat-dependent optima. Individual-based simulations mimicking our empirical system confirmed that these patterns are expected under the selective regime inferred. We show that homogenizing selection can mimic some effect of drift on the G matrix (G and D almost proportional), but that incorporating information from molecular markers (multivariate Q(st)-F(st)) allows disentangling the two effects.

Estudio psicométrico del test de Bohem de Conceptos Básicos en la población asturiana.

Realizar un estudio de las propiedades psicométricas del test de Boehm de Conceptos Básicos (BTBC) a partir de las respuestas emitidas por escolares asturianos. 153 alumnos de Preescolar-1, 136 de Preescolar-2 y 205 de primero de EGB del Principado de Asturias, distribuidos en función del sexo y la clase social. Muestreo aleatorio estratificado con afijación proporcional dentro de la población escolar. Cálculo de los coeficientes de fiabilidad, validez e indices de dificultad y discriminación. Baremación de la prueba para la población asturiana. Para cada uno de los análisis se toma individualmente los tres grupos resultantes de los niveles escolares a los que pertenecen los sujetos de la muestra, pretendiendo con ello observar el comportamiento del test en cada grupo de edad. BTBC, WIPPSI, WIC y test de matrices progresivas de colores de Raven. Calificación académica en Lenguaje. La fiabilidad se calculó por tres métodos: dos mitades, alpha de Cronbach y zeta de Carmines. La validez se calculó por medio de correlaciones con otros tests y el análisis de componentes principales. Fiabilidad: para los dos grupos de Preescolar, los coeficientes son relativamente altos en todos los casos, produciéndose una baja significativa en el grupo de primero de EGB; también se observa que los resultados alcanzados son levemente inferiores a los aportados en el manual de la versión castellana. Validez: el test tiene una aceptable relación con las pruebas elegidas como criterio y con la calificación en lenguaje; se corrobora que el BTBC es un test multidimensional. Dificultad y discriminación: en la primera mitad los índices de dificultad son muy altos, de los que se derivan unos niveles de discriminación muy bajos para la mayor parte de los ítems; la segunda parte del test tiene unos índices de dificultad con valores más bajos y la discriminación mejora; al mismo tiempo, los resultados indican que los ítems aun cuando presentan una diferenciación en dificultad entre los correspondientes a la primera y segunda mitad, no mantienen un riguroso orden de dificultad creciente. Baremación: los datos obtenidos indican la necesidad de que se realice una unica baremación para todos los sujetos en los dos cursos de Preescolar y tres baremaciones, según los tres niveles de clase social, para el primer curso de EGB. En términos generales, se concluye que los valores obtenidos en los diferentes análisis caen dentro de niveles 'razonablemente' aceptables, no pudiendo olvidar nunca las especiales características de esta prueba.

Medida del factor G de la inteligencia a través del test de los naipes.

Lograr un test que pueda ser utilizado para la mensuración del factor 'G' de la inteligencia y que posea una mayor saturación en factor 'G' que otros tests y una menor saturación en otros factores intelectuales. 139 sujetos entre 18 y 35 años, cursillistas de cursos de formación intensiva de Ciappe. 106 sujetos entre 17 y 20 años estudiantes del Liceo Francés de Barcelona. 119 niños entre 10 y 12 años estudiantes de cuarto y quinto del antiguo Bachillerato. 1. Elección del diseño y disposición formal de los elementos. 2. Fase de ideación del test: primeros ensayos del diseño con los prototipos (a y b) a partir de los cuales se crea un tercer prototipo (c) más operativo. 3. Fase de perfeccionamiento: nuevos ensayos que dan lugar a los prototipos d, e, f, g, siendo la forma definitiva del test de naipes. Cada test se aplica a una muestra concreta. 4. Aplicación del test definitivo a tres muestras diferenciadas entre sí en cuanto a edad y nivel de instrucción. 5. Aplicación de otros tests (matrices progresivas y dominós) a esas tres muestras y correlación con el test de naipes. 6. Análisis de los resultados y conclusiones. Test de naipes: 80 ítems. Test de dominós: 44 ítems. Matrices progresivas: 60 ítems. Tests factoriales (factores e, n, r) de la batería Ampe y de la batería de Ciappe del autor de la tesis. Coeficiente de correlación. Índices de validez. Tabla de frecuencias. Diferencias intercuartiles. Percentiles. Diagrama de barras. Media móvil (orden 5). Suavización. Se confirma la hipótesis de que el test de naipes puede ser un test capaz de medir el factor 'G' de inteligencia. Puede considerarse 'test universal' aplicable a las distintas culturas, en el campo escolar (a partir de los 7 años), para clasificar, diagnosticar y verificar rendimientos de sujetos en el campo industrial (orientación profesional, selección de personal) y en otros campos como el judicial, militar o Psicología. Las ventajas de este test son su mayor agradabilidad y el ser más comercial y económico.

Baremación en población española del Test de esquema corporal de C. Daurathmeljak, M. Stambak y J. Berges.

Baremar en población española la prueba citada. Comprobar si existen diferencias significativas entre sexos. Comprobar si la adquisición del esquema corporal está ligada al desarrollo educativo de la persona y por lo tanto a la edad. 160 escolares de edades comprendidas entre 4 y 11 años, de ambos sexos. Se establecieron diez sujetos por sexo en cada intervalo de edad, que reunieran las siguientes características: correspondencia de curso con la edad, rendimiento escolar medio, ausencia de trastornos de conducta observables, percentil 75 o más en inteligencia. Aplicación de la prueba de esquema corporal a los 160 sujetos seleccionados con los requisitos anteriormente descritos. Estudio estadístico. Construcción de las tablas de baremación. Informe del profesor, evaluaciones escolares, test de matrices progresivas (escala especial de cuatro a once años) de Raven, prueba de esquema corporal. Análisis estadístico. Distribución de frecuencias por edad y sexo. Medidas de tendencia central: cuartiles, mediana, media. Medidas de dispersión. Desviación típica. Medidas de estudio significativo. T de Student. No existen diferencias significativas entre sexos por grupo de edad, a excepción de los once años, favorable al sexo femenino. Trazado de un perfil por edad, que permite la comparación rápida de un individuo con su grupo de edad. Existen tres etapas de adquisición del esquema corporal: 1. Entre 4-5 años; 2. 6-7 años; 3. 8-11 años. La adquisición del esquema corporal se produce de forma progresiva y en relación con el desarrollo evolutivo del individuo. Los resultados de la prueba posibilitan la distribución del conocimiento del cuerpo y de la cara en tres etapas fundamentales. La realización de este trabajo permite la comparación, mediante las tablas de perfiles de edad, con sujetos que tengan algún trastorno asociado a problemas del esquema corporal.

El test de Goodenough en la orientación escolar.

Intentar ver la consistencia de medida de la inteligencia que aporta el test de Goodenough desde el primer curso de Preescolar hasta el último curso de EGB. Comparar los resultados obtenidos con un test admitido generalmente como un buen instrumento de medida del desarrollo de la inteligencia desde la infancia como es la serie ideada por J.C. Raven: 'matrices progresivas en color', edición de 1956 (series A, Ab, B) que extiende su cobertura desde primero de EGB hasta el quinto curso, y 'matrices progresivas, escala general', revisión 1956 (series A, B, C, D, E) aplicados desde sexto a octavo EGB. 530 sujetos. Raven. D-48. Tea-2. Caras. Fluidez Verbal. Rendimiento escolar. Según los datos hay una muy amplia gama de correlaciones entre el test de Goodenough y el de Raven, dato que nos hace pensar que el test de Raven y el Goodenough miden aspectos distintos de lo que hemos dado en llamar inteligencia. Debemos reseñar que otra razón bastante poderosa para elegir el test de Raven como criterio, ha sido su cualidad de test no verbal, al igual que el Goodenough. Por otra parte, nuestros resultados nos llevan a afirmar que lo que mide el test de Raven: (el factor g de Spearman) es algo bastante diferente de lo que mide el Goodenough, (capacidad de observación analítica, asociación, discriminación, memoria de detalles, abstracción, coordinación visomanual). En lo que se refiere al pronóstico del rendimiento escolar a partir de test de pronóstico académico, al menos directamente. Todas las correlaciones con rendimiento escolar son positivas, pero muy bajas. El test de Goodenough no es un instrumento válido para el diagnóstico de la inteligencia y el pronóstico académico con lo cual se rechaza la hipótesis de trabajo. Igualmente creemos que queda suficientemente claro que no pueden utilizarse ambos tests (Raven y Goodenough) como unidad de medida de una misma función o actividad psíquica.

Test performance indicators from a single soccer specific fitness test differentiate between highly trained and recreationally active soccer players

Aim. The aim of this study was to investigate whether a single soccer specific fitness test (SSFT) could differentiate between highly trained and recreationally active soccer players in selected test performance indicators. Methods. Subjects: 13 Academy Scholars (AS) from a professional soccer club and 10 Recreational Players (RP) agreed to participate in this study. Test 1-(V)over dotO(2) max was estimated from a progressive shuttle run test to exhaustion. Test 2-The SSFT was controlled by an automated procedure and alternated between walking, sprinting, jogging and cruise running speeds. Three activity blocks (1A, 2A and 3A) were separated by 3 min rest periods in which blood lactate samples were drawn. The 3 blocks of activity (Part A) were followed by 10 min of exercise at speeds alternating between jogging and cruise running (Part B). Results. Estimated (V)over dotO(2) max did not significantly differ between groups, although a trend for a higher aerobic capacity was evident in AS (p<0.09). Exercising heart rates did not differ between AS and RP, however, recovery heart rates taken from the 3 min rest periods were significantly lower in AS compared with RP following blocks 1A (124.65 b(.)min(-1) +/-7.73 and 133.98 b(.)min(-1) +/-6.63), (p<0.05) and 3A (129.91 b.min(-1) +/-10.21 and 138.85 b.min(-1) +/-8.70), (p<0.01). Blood lactate concentrations were significantly elevated in AS in comparison to RP following blocks 2A (6.91 mmol(.)l(-1) +/-2.67 and 4.74 mmol(.)l(-1) +/-1.28) and 3A (7.18 mmol(.)l(-1) +/-2.97 and 4.88 mmol(.)l(-1) +/-1.50), (p<0.05). AS sustained significantly faster average sprint times in block 3A compared with RP (3.18 sec +/-0.12 and 3.31 sec +/-0.12), (p<0.05). Conclusion. The results of this study show that highly trained soccer players are able to sustain, and more quickly recover from, high intensity intermittent exercise.

A note on the eigenvalues of a special class of matrices

In the analysis of stability of a variant of the Crank-Nicolson (C-N) method for the heat equation on a staggered grid a class of non-symmetric matrices appear that have an interesting property: their eigenvalues are all real and lie within the unit circle. In this note we shall show how this class of matrices is derived from the C-N method and prove that their eigenvalues are inside [-1, 1] for all values of m (the order of the matrix) and all values of a positive parameter a, the stability parameter sigma. As the order of the matrix is general, and the parameter sigma lies on the positive real line this class of matrices turns out to be quite general and could be of interest as a test set for eigenvalue solvers, especially as examples of very large matrices. (C) 2010 Elsevier B.V. All rights reserved.

The effects of progressive resistance training combined with a whey-protein drink and vitamin D supplementation on glycaemic control, body composition and cardiometabolic risk factors in older adults with type 2 diabetes: study protocol for a randomized c

While physical activity, energy restriction and weight loss are the cornerstone of type 2 diabetes management, less emphasis is placed on optimizing skeletal muscle mass. As muscle is the largest mass of insulin-sensitive tissue and the predominant reservoir for glucose disposal, there is a need to develop safe and effective evidence-based, lifestyle management strategies that optimize muscle mass as well as improve glycaemic control and cardiometabolic risk factors in people with this disease, particularly older adults who experience accelerated muscle loss.

Demographic and metabolic characteristics of individuals with progressive glucose tolerance

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

MATHEMATICA notebook for computing tetrahedral finite element shape functions and matrices for the Helmholtz equation

A MATHEMATICA notebook to compute the elements of the matrices which arise in the solution of the Helmholtz equation by the finite element method (nodal approximation) for tetrahedral elements of any approximation order is presented. The results of the notebook enable a fast computational implementation of finite element codes for high order simplex 3D elements reducing the overheads due to implementation and test of the complex mathematical expressions obtained from the analytical integrations. These matrices can be used in a large number of applications related to physical phenomena described by the Poisson, Laplace and Schrodinger equations with anisotropic physical properties.