On the p,qp,q-binomial distribution and the Ising model

A completely new approach to the Ising model in 1 to 5 dimensions is developed. We employ $p,q$-binomial coefficients, a generalisation of the binomial coefficients, to describe the magnetisation distributions of the Ising model. For the complete graph this distribution corresponds exactly to the limit case $p=q$. We take our investigation to the simple $d$-dimensional lattices for $d=1,2,3,4,5$ and fit $p,q$-binomial distributions to our data, some of which are exact but most are sampled. For $d=1$ and $d=5$ the magnetisation distributions are remarkably well-fitted by $p,q$-binomial distributions. For $d=4$ we are only slightly less successful, while for $d=2,3$ we see some deviations (with exceptions!) between the $p,q$-binomial and the Ising distribution. We begin the paper by giving results on the behaviour of the $p,q$-distribution and its moment growth exponents given a certain parameterization of $p,q$. Since the moment exponents are known for the Ising model (or at least approximately for $d=3$) we can predict how $p,q$ should behave and compare this to our measured $p,q$. The results speak in favour of the $p,q$-binomial distribution's correctness regarding their general behaviour in comparison to the Ising model. The full extent to which they correctly model the Ising distribution is not settled though.Comment: 51 pages, 23 figures, submitted to PRB on Oct 23 200

Validez de predicción de los criterios de admisión a la Universidad de Puerto Rico

This research consisted of a validity study to evaluate the predictive power of the components of the University of Puerto Rico’s admissions formula. The three components have been academic in nature: high school GPA, standardized aptitude tests scores, and standardized achievement tests scores. Various multiple regression equations were generated to determine the joint and individual predictive power of the formula components. Aptitude and achievement tests scores’ predictive power were compared. Based on the research findings, recommendations for possible modifications to the admissions formula are proposed. How to cite: Colorado-Laguna, R. J., & Corcino-Marrero, L. (2013). Validez de predicción de los criterios de admisión a la Universidad de Puerto Rico. Pedagogía, 46(1), 66-92. Retrieved from https://revistas.upr.edu/index.php/educacion/article/view/16416Esta investigación consistió de un estudio de validez para evaluar el poder de predicción de los componentes de la fórmula de admisión a la Universidad de Puerto Rico, Recinto de Río Piedras. Los tres componentes han sido de carácter académico: el promedio de escuela superior, las puntuaciones en las dos pruebas de aptitud y las puntuaciones en las tres pruebas de aprovechamiento. Se generaron modelos de regresión múltiple para determinar el poder de predicción conjunto y relativo de cada uno de los predictores. Se establecieron comparaciones entre la validez de predicción de las pruebas de aptitud y las pruebas de aprovechamiento. A partir de los resultados del estudio, se formularon recomendaciones sobre posibles modificaciones a la fórmula de admisión. Cómo citar: Colorado-Laguna, R. J., & Corcino-Marrero, L. (2013). Validez de predicción de los criterios de admisión a la Universidad de Puerto Rico. Pedagogía, 46(1), 66-92. Recuperado a partir de https://revistas.upr.edu/index.php/educacion/article/view/1641

Validez de predicción de los criterios de admisión, por género, a la Universidad de Puerto Rico

This research consisted of a validity study to determine gender differences with respect to aptitude and achievement tests scores, a set of college success predictors, and the relative predictive power of each predictor. Results confirmed nationwide findings with respect to tests scores. However, tendencies with respect to correlation coefficients’ magnitude were partially confirmed. The three best predictors of short time and longtime college success, for each gender, coincided in the first two: high school academic average and verbal aptitude test score. The third best predictor of college success for females, short term and long term, was the English achievement test score. How to cite: Colorado-Laguna, R. J., & Corcino-Marrero, L. (2013). Validez de predicción de los criterios de admisión, por género, a la Universidad de Puerto Rico. Cuaderno de Investigación en la Educación, 28, 185-210. Retrieved from https://revistas.upr.edu/index.php/educacion/article/view/13579Esta investigación consistió de un estudio de validez para determinar posibles diferencias de género en las puntuaciones en las pruebas de aptitud y de aprovechamiento, el conjunto de predictores de éxito universitario, y el poder de predicción relativa de cada predictor. Los resultados constataron tendencias registradas en los Estados Unidos respecto a diferencias de género en las puntuaciones en pruebas de aptitud y aprovechamiento. Por otro lado, parcialmente corroboraron tendencias de género respecto a la magnitud de los coeficientes de correlación entre predictores y criterios. Los tres mejores predictores de éxito universitario para mujeres y varones, a corto y a largo plazos, coinciden en dos de los predictores: el promedio de escuela superior y la puntuación en la prueba de aptitud verbal. El tercer mejor predictor para mujeres fue, a corto y largo plazos, la puntuación en la prueba de aprovechamiento en inglés. Cómo citar: Colorado-Laguna, R. J., & Corcino-Marrero, L. (2013). Validez de predicción de los criterios de admisión, por género, a la Universidad de Puerto Rico. Cuaderno de Investigación en la Educación, 28, 185-210. Recuperado a partir de https://revistas.upr.edu/index.php/educacion/article/view/1357

Control of prostate cancer associated with withdrawal of a supplement containing folic acid, L-methyltetrahydrofolate and vitamin B12: a case report

<p>Abstract</p> <p>Introduction</p> <p>This is the first report of possible direct stimulation of hormone-resistant prostate cancer or interference of docetaxel cytotoxicity of prostate cancer in a patient with biochemical relapse of prostatic-specific antigen. This observation is of clinical and metabolic importance, especially at a time when more than 80 countries have fortified food supplies with folic acid and some contemplate further fortification with vitamin B₁₂.</p> <p>Case presentation</p> <p>Our patient is a 71-year-old Caucasian man who had been diagnosed in 1997 with prostate cancer, stage T1c, and Gleason score 3+4 = 7. His primary treatment included intermittent androgen deprivation therapy including leuprolide + bicalutamide + deutasteride, ketoconazole + hydrocortisone, nilandrone and flutamide to resistance defined as biochemical relapse of PSA. While undergoing docetaxel therapy to treat a continually increasing prostate-specific antigen level, withdrawal of 10 daily doses of a supplement containing 500 μg of vitamin B₁₂as cyanocobalamin, as well as 400 μg of folic acid as pteroylglutamic acid and 400 μg of L-5-methyltetrahydrofolate for a combined total of 800 μg of mixed folates, was associated with a return to a normal serum prostatic-specific antigen level.</p> <p>Conclusion</p> <p>This case report illustrates the importance of the effects of supplements containing large amounts of folic acid, L-5-methyltetrahydrofolate, and cyanocobalamin on the metabolism of prostate cancer cells directly and/or B vitamin interference with docetaxel efficacy. Physicians caring for patients with prostate cancer undergoing watchful waiting, hormone therapy, and/or chemotherapy should consider the possible acceleration of tumor growth and/or metastasis and the development of drug resistance associated with supplement ingestion. We describe several pathways of metabolic and epigenetic interactions that could affect the observed changes in serum levels of prostate-specific antigen.</p

Was it Uruguay or Coffee? The causes of the beef jerky industry’s decline in southern Brazil (1850 – 1889)

What caused the decline of the beef jerky’s production in Brazil? The main sustenance for slaves, beef jerky was the most important industry in southern Brazil. Nevertheless, by 1850, producers were already worried that they could not compete with Uruguayan industry. Traditional interpretations impute the decline to labor markets differences in productivity, since Brazil used slaves while Uruguay had abolished slavery in 1842. Recent research also raises the possibility of a Brazilian “Dutch Disease”, resulting from the coffee exports boom. We test both hypothesis and argue that Brazilian production’s decline was associated with structural changes in demand for low quality meat. Trade protection policies created disincentives for Brazilian producers to increase productivity and diversify its cattle industry

Percepción y receptividad al proceso de coaching como componente de un programa de desarrollo profesional para maestros de escuela primaria

Paradígma, vol.35, n.1, pp. 79-102La participación en actividades de desarrollo profesional es indispensable para el fortalecimiento de la carrera magisterial. La estrategia de coaching, como modelo de desarrollo profesional para maestros, ha cobrado auge en los últimos años. Este estudio persiguió auscultar el nivel de satisfacción y la receptividad de un grupo de maestros de escuela primaria hacia la práctica de coaching, como uno de los componentes de un proyecto de desarrollo profesional. Las respuestas a cuestionarios administrados a maestros y coaches, reflejaron un nivel de satisfacción relativamente alto con la práctica de coaching. Se incluyen recomendaciones para optimizar los beneficios del coaching

Diferencias en el desempeño académico y en los predictores de éxito universitario por escuela de procedencia

The purpose of this research was to explore possible differences between public and private school students with respect to: scores on standardized aptitude and achievement tests used as admission criteria to higher education institutions in Puerto Rico, the set of college success predictors, and the relative predictive value of each predictor, individually and in combination with other predictors. Major study findings were: private school students’ aptitude and achievement tests scores were higher than those of public school students; correlation coefficients between selected predictors and criteria, freshman’s GPA and graduation’s GPA, were higher for private school students, and the set of college success predictors for both school types were similar. Possible explanations for the differences in academic performance are considered. How to cite: Colorado-Laguna, R. J., &amp; Corcino-Marrero, L. (2014). Diferencias en el desempeño académico y en los predictores de éxito universitario por escuela de procedencia. Pedagogía, 47(1), 159-191. Retrieved from https://revistas.upr.edu/index.php/educacion/article/view/16364El propósito de esta investigación fue explorar posibles diferencias entre estudiantes procedentes de escuela pública y escuela privada respecto a las puntuaciones en las pruebas estandarizadas de aptitud y de aprovechamiento utilizadas como criterios de admisión a las instituciones universitarias en Puerto Rico, el conjunto de predictores de éxito universitario y la utilidad de predicción de cada predictor, individualmente y en conjunto. Los resultados fueron los siguientes: los estudiantes de escuela privada obtuvieron puntuaciones promedio mayores que los estudiantes de escuela pública en las pruebas de aptitud y en las pruebas de aprovechamiento; los coeficientes de correlación entre predictores y criterios, promedio de primer año de estudios universitarios y promedio de graduación, fueron mayores para estudiantes procedentes de escuela privada, y los predictores de éxito universitario de estudiantes procedentes de ambos tipos de escuela fueron similares. Se incluyen posibles explicaciones para las diferencias en el desempeño académico de los estudiantes procedentes de ambos tipos de escuela. Cómo citar: Colorado-Laguna, R. J., &amp; Corcino-Marrero, L. (2014). Diferencias en el desempeño académico y en los predictores de éxito universitario por escuela de procedencia. Pedagogía, 47(1), 159-191. Recuperado a partir de https://revistas.upr.edu/index.php/educacion/article/view/1636

Jejunal Perfusion of Simple and Conjugated Folates in Tropical Sprue

Absorption of labeled simple 3′,5′,9′-(3)H pteroylmonoglutamate, ([(3)H]PG-1) and conjugated pteroyl-μ[(14)C]glutamyl-γ-hexaglutamate, ([(14)C]PG-7) folates was assessed in six patients with tropical sprue, before and after 6 mo of treatment, utilizing jejunal perfusion and urinary recovery techniques. Degradation products of [(14)C]PG-7 which were produced during perfusion were identified by DEAE-cellulose column chromatography. Jejunal mucosal activities of folate conjugase, lactase, sucrase, and maltase were measured in every patient. Malabsorption of both [(3)H]PG-1 and [(14)C]PG-7 was found in every untreated patient, with significant improvement after therapy. The urinary excretion of (3)H and (14)C paralleled the luminal disappearance of both isotopes. The chromatographic patterns of intraluminal degradation products of [(14)C]PG-7 obtained during perfusion did not differ from those previously found in normal subjects and were similar in studies performed before and after treatment. The activity of folate conjugase was increased in the mucosa of the untreated patients when compared to the post-treatment levels while the activities of mucosal lactase, sucrase, and maltase were originally low and increased significantly after therapy. These observations suggest that folate conjugase originates at a different mucosal locus than the brush border disaccharidases, and are consistent with previous evidence that folate conjugase is an intracellular enzyme. The present studies have demonstrated unequivocal malabsorption of both simple and conjugated folates in tropical sprue. In tropical sprue, folate malabsorption is the reflection of impaired folate transport and not of impaired hydrolysis