¿Puede hablarse de acumulación y progreso en las ciencias sociales?

No es inusual la opinión de que el conocimie1úo científico-social se caracteriza por una proliferación teórica que conspira contra toda posibilidad de afirmar que, en ese campo, se da alguna clase de progreso. Mucho pesa en este tipo de evaluación la renuencia de los teóricos a reconocer explícitamente influencias de otros investigadores en sus propias construcciones y desarrollos, así como la vigencia de una concepción de progreso cuya necesidad y pertinencia se pretende examinar en el presente trabajo. La presentación se articula a partir de la consideración de la que podría denominarse concepción dominante del progreso científico entre quienes estudian las teorías sociales desde un metanivel. Para ello se discutirán las posiciones sustentadas por Agnes Heller y Michel Foucault v se las contrastará con las nociones de progreso y acumulación emergentes de un análisis estructural, con especial alusión a los conceptos de red teórica y de holán teórico

Captación artificial y crecimiento temprano de la semilla de Argopecten puppuratus (Lamarck, 1819) en la Reserva Marina La Rinconada, Antofagasta, Chile

Artificial collection of early juveniles (“spat”) of the scallop Argopecten purpuratus in Japanese-type collectors was evaluated between January 2001 and July 2002 in the La Rinconada Marine Reserve, Antofagasta, Chile. This area of Antofagasta Bay has in the past been noted for the retention of scallop larvae by local gyres, in which their numbers can vary between 89 and 34175 larvae m-3, producing larval sets of 400 to 15340 post-larvae (spat) per collector. The results showed no quantitative relationship between larval abundance in the water and the spat density collected per day in the collectors, although high settlement rates were associated with high numbers of umboned larvae in the water. Allowing collectors to remain in situ for extended periods of 88 and 159 days resulted in a severe loss of seed which had settled in the collectors during the first 28 to 40 days of immersion. These losses varied between 50.9 and 99.6% of the spat collected, and were more prejudicial for the smaller cohorts that had settled in the collectors at the end of the first immersion period. The growth rates measured among different cohorts for each immersion period varied between 81.3 and 235.2 mm/day for the first cohort (C1) and between 64.0 and 167.4 mm/day for the second cohort (C2). The highest growth rates occurred in collectors containing the lowest numbers of spat after the occurrence of spat losses during the long periods of immersion. Occurrence of intraspecific competition within the collectors is discussed as potentially responsible for the decreases in spat numbers and the variations observed in their growth rates.Un programa mensual de captación de A. purpuratus, implementado en la reserva marina de La Rinconada, entre enero de 2001 y julio de 2002, la caracterizó como zona de retención larvaria, con densidades variando entre 89 y 34175 larvas m-3, y de fijaciones entre 400 y 15340 post-larvas por colector. No se encontró una relación directa entre abundancia larvaria y asentamiento, sin embargo, las mayores captaciones estuvieron asociadas a la presencia de un elevado número de estados umbonados. La mantenimiento prolongado de colectores in situ, por periodos que variaron entre 88 y 159 días, provocó una fuerte reducción en el número de semillas que se asentaron en ellos durante los primeros 28 a 40 días de inmersión Estas reducciones variaron entre el 99.6 y el 50.9% de la semilla fijada, siendo las más perjudicadas las cohortes más pequeñas, asentadas al final del primer periodo de inmersión. Las tasas de crecimiento registradas en estas cohortes, para cada periodo de inmersión, variaron entre 81.3 y 235.2 ìm/día para las cohortes C1 y entre 64.0 y 167.4 ìm/día para las cohortes C2. Las mayores tasas están directamente relacionadas con un menor número de semilla recuperada. Se discuten las competencias intraespecíficas ocurridas en los colectores, como responsables de la disminución del número de semilla y de las variaciones registradas en sus tasas de crecimiento

Molecular thermodynamics of adsorption using discrete-potential systems

A molecular thermodynamics approach has been developed in order to describe the adsorption of fluids onto solid surfaces based on the use of discrete-potential fluid models. Using perturbation theories for fluids such as the Statistical Associating Fluid Theory (SAFT) and the Discrete Potential Theory (DPT), in combination with molecular simulation, we have formulated a two-dimensional approach to describe systems of interest for the oil industry, such as adsorption isotherms of carbon dioxide and asphaltenes

Kisspeptins and the neuroendocrine control of reproduction: Recent progress and new frontiers in kisspeptin research

In late 2003, a major breakthrough in our understanding of the mechanisms that govern reproduction occurred with the identification of the reproductive roles of kisspeptins, encoded by the Kiss1 gene, and their receptor, Gpr54 (aka, Kiss1R). The discovery of this unsuspected reproductive facet attracted an extraordinary interest and boosted an intense research activity, in human and model species, that, in a relatively short period, established a series of basic concepts on the physiological roles of kisspeptins. Such fundamental knowledge, gathered in these early years of kisspeptin research, set the scene for the more recent in-depth dissection of the intimacies of the neuronal networks involving Kiss1 neurons, their precise mechanisms of regulation and the molecular underpinnings of the function of kisspeptins as pivotal regulators of all key aspects of reproductive function, from puberty onset to pulsatile gonadotropin secretion and the metabolic control of fertility. While no clear temporal boundaries between these two periods can be defined, in this review we will summarize the most prominent advances in kisspeptin research occurred in the last ten years, as a means to provide an up-dated view of the state of the art and potential paths of future progress in this dynamic, and ever growing domain of Neuroendocrinology

Revisit Sparse Polynomial Interpolation based on Randomized Kronecker Substitution

In this paper, a new reduction based interpolation algorithm for black-box multivariate polynomials over finite fields is given. The method is based on two main ingredients. A new Monte Carlo method is given to reduce black-box multivariate polynomial interpolation to black-box univariate polynomial interpolation over any ring. The reduction algorithm leads to multivariate interpolation algorithms with better or the same complexities most cases when combining with various univariate interpolation algorithms. We also propose a modified univariate Ben-or and Tiwarri algorithm over the finite field, which has better total complexity than the Lagrange interpolation algorithm. Combining our reduction method and the modified univariate Ben-or and Tiwarri algorithm, we give a Monte Carlo multivariate interpolation algorithm, which has better total complexity in most cases for sparse interpolation of black-box polynomial over finite fields

Surgical treatment of congenital pseudoarthrosis of the clavicle: Our 22-year, single-center experience

Objectives: This study reports the surgical outcomes in a patient cohort with congenital pseudarthrosis of the clavicle (CPC). Patients and methods: A total of nine pediatric patients (5 males, 4 females; mean age: 4.43 years; range, 2 to 12 years) who were diagnosed with CPC and treated surgically with a minimum one-year follow-up between January 1996 and December 2018 were retrospectively analyzed. The patients were divided into two groups according to the fixation method as the Kirschner wire (K-wire; Group A, n=2) or stabilization with a plate (Group B, n=7). The physical function and symptoms were evaluated using the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scale. Results: The mean age at the time of diagnosis was 2.95 (range, 0 to 12) years. Six cases were atrophic pseudarthrosis and three cases were hypertrophic. Radiographic consolidation occurred in all cases with a mean duration of 103.8±39.1 days, indicating no significant difference between the groups (p>0.05). Complications registered were a K-wire breakage in a patient in Group A and an internal fixation plate loosening in a patient in Group B. The mean postoperative follow-up was 2.98±1.82 years. The QuickDASH score was 0 points in all patients. Conclusion: The early surgical indication based on refreshment of the pseudarthrosis focus, with bone autograft interposition when a failure exists to restore adequate clavicular length, and fixation are reliable alternatives with favorable clinical and radiological results in the mid- and long-term with fewer complications