Que ningún desgraciado muera de hambre: agricultura, reciprocidad y reelaboración de identidades entre los ranqueles en la década de 1840

La imagen de las sociedades indígenas que habitaron las pampas rioplatenses con posterioridad al siglo XVI - y especialmente la visión acerca de su economía - ha sido objeto de una profunda revisión historiográfica y antropológica en las últimas décadas. La perspectiva que sólo se limitaba a consignar diversas formas predatorias fue reemplazada por un enfoque más amplio que reconoce la variedad y complejidad de la organización productiva. El propósito de este artículo - inscripto en ese enfoque - consiste en analizar las condiciones históricas que rodearon la incorporación y actualización de prácticas agrícolas por parte de los ranqueles durante la década de 1840, utilizando como fuente principal un texto descriptivo de las profundas transformaciones experimentadas por aquellos, redactado por el joven cautivo Santiago Avendaño y omitido en las versiones editadas de sus memorias. Luego de las gravosas derrotas sufridas en los años 30, los ranqueles lograron reconstruir su deteriorada base demográfica y económica, entre otros medios, incorporando contingentes boroganos, y con ellos ciertos manejos agrícolas de origen trasandino. La combinación de estos últimos con los tradicionales dio como resultado un conjunto flexible y diversificado que, unido a una nueva política de comensalidad consistente en la extensión fuera de sus límites normales de la reciprocidad generalizada, fue capaz de sustentar la recuperación social del grupo.

Que ningún desgraciado muera de hambre: agricultura, reciprocidad y reelaboración de identidades entre los ranqueles en la década de 1840

La imagen de las sociedades indígenas que habitaron las pampas rioplatenses con posterioridad al siglo XVI - y especialmente la visión acerca de su economía - ha sido objeto de una profunda revisión historiográfica y antropológica en las últimas décadas. La perspectiva que sólo se limitaba a consignar diversas formas predatorias fue reemplazada por un enfoque más amplio que reconoce la variedad y complejidad de la organización productiva. El propósito de este artículo - inscripto en ese enfoque - consiste en analizar las condiciones históricas que rodearon la incorporación y actualización de prácticas agrícolas por parte de los ranqueles durante la década de 1840, utilizando como fuente principal un texto descriptivo de las profundas transformaciones experimentadas por aquellos, redactado por el joven cautivo Santiago Avendaño y omitido en las versiones editadas de sus memorias. Luego de las gravosas derrotas sufridas en los años 30, los ranqueles lograron reconstruir su deteriorada base demográfica y económica, entre otros medios, incorporando contingentes boroganos, y con ellos ciertos manejos agrícolas de origen trasandino. La combinación de estos últimos con los tradicionales dio como resultado un conjunto flexible y diversificado que, unido a una nueva política de comensalidad consistente en la extensión fuera de sus límites normales de la reciprocidad generalizada, fue capaz de sustentar la recuperación social del grupo.

Que ningún desgraciado muera de hambre: agricultura, reciprocidad y reelaboración de identidades entre los ranqueles en la década de 1840

La imagen de las sociedades indígenas que habitaron las pampas rioplatenses con posterioridad al siglo XVI - y especialmente la visión acerca de su economía - ha sido objeto de una profunda revisión historiográfica y antropológica en las últimas décadas. La perspectiva que sólo se limitaba a consignar diversas formas predatorias fue reemplazada por un enfoque más amplio que reconoce la variedad y complejidad de la organización productiva. El propósito de este artículo - inscripto en ese enfoque - consiste en analizar las condiciones históricas que rodearon la incorporación y actualización de prácticas agrícolas por parte de los ranqueles durante la década de 1840, utilizando como fuente principal un texto descriptivo de las profundas transformaciones experimentadas por aquellos, redactado por el joven cautivo Santiago Avendaño y omitido en las versiones editadas de sus memorias. Luego de las gravosas derrotas sufridas en los años 30, los ranqueles lograron reconstruir su deteriorada base demográfica y económica, entre otros medios, incorporando contingentes boroganos, y con ellos ciertos manejos agrícolas de origen trasandino. La combinación de estos últimos con los tradicionales dio como resultado un conjunto flexible y diversificado que, unido a una nueva política de comensalidad consistente en la extensión fuera de sus límites normales de la reciprocidad generalizada, fue capaz de sustentar la recuperación social del grupo.

A study of employee affective organisational commitment and retention in Pakistan:the roles of psychological contract breach and norms of reciprocity

Social exchange theory and notions of reciprocity have long been assumed to explain the relationship between psychological contract breach and important employee outcomes. To date, however, there has been no explicit testing of these assumptions. This research, therefore, explores the mediating role of negative, generalized, and balanced reciprocity, in the relationships between psychological contract breach and employees’ affective organizational commitment and turnover intentions. A survey of 247 Pakistani employees of a large public university was analyzed using structural equation modeling and bootstrapping techniques, and provided excellent support for our model. As predicted, psychological contract breach was positively related to negative reciprocity norms and negatively related to generalized and balanced reciprocity norms. Negative and generalized (but not balanced) reciprocity were negatively and positively (respectively) related to employees’ affective organizational commitment and fully mediated the relationship between psychological contract breach and affective organizational commitment. Moreover, affective organizational commitment fully mediated the relationship between generalized and negative reciprocity and employees’ turnover intentions. Implications for theory and practice are discussed.

Dependence of the crossover exponent with the diffusion rate in the generalized contact process model

We study how the crossover exponent, phi, between the directed percolation (DP) and compact directed percolation (CDP) behaves as a function of the diffusion rate in a model that generalizes the contact process. Our conclusions are based in results pointed by perturbative series expansions and numerical simulations, and are consistent with a value phi = 2 for finite diffusion rates and phi = 1 in the limit of infinite diffusion rate.

Data collapse, scaling functions, and analytical solutions of generalized growth models

We consider a nontrivial one-species population dynamics model with finite and infinite carrying capacities. Time-dependent intrinsic and extrinsic growth rates are considered in these models. Through the model per capita growth rate we obtain a heuristic general procedure to generate scaling functions to collapse data into a simple linear behavior even if an extrinsic growth rate is included. With this data collapse, all the models studied become independent from the parameters and initial condition. Analytical solutions are found when time-dependent coefficients are considered. These solutions allow us to perceive nontrivial transitions between species extinction and survival and to calculate the transition's critical exponents. Considering an extrinsic growth rate as a cancer treatment, we show that the relevant quantity depends not only on the intensity of the treatment, but also on when the cancerous cell growth is maximum.

Generalized connectivity between any two nodes in a complex network

This article focuses on the identification of the number of paths with different lengths between pairs of nodes in complex networks and how these paths can be used for characterization of topological properties of theoretical and real-world complex networks. This analysis revealed that the number of paths can provide a better discrimination of network models than traditional network measurements. In addition, the analysis of real-world networks suggests that the long-range connectivity tends to be limited in these networks and may be strongly related to network growth and organization.

Generalized Sznajd model for opinion propagation

In the last decade the Sznajd model has been successfully employed in modeling some properties and scale features of both proportional and majority elections. We propose a version of the Sznajd model with a generalized bounded confidence rule-a rule that limits the convincing capability of agents and that is essential to allow coexistence of opinions in the stationary state. With an appropriate choice of parameters it can be reduced to previous models. We solved this model both in a mean-field approach (for an arbitrary number of opinions) and numerically in a Barabaacutesi-Albert network (for three and four opinions), studying the transient and the possible stationary states. We built the phase portrait for the special cases of three and four opinions, defining the attractors and their basins of attraction. Through this analysis, we were able to understand and explain discrepancies between mean-field and simulation results obtained in previous works for the usual Sznajd model with bounded confidence and three opinions. Both the dynamical system approach and our generalized bounded confidence rule are quite general and we think it can be useful to the understanding of other similar models.

Coexistence of interacting opinions in a generalized Sznajd model

The Sznajd model is a sociophysics model that mimics the propagation of opinions in a closed society, where the interactions favor groups of agreeing people. It is based in the Ising and Potts ferromagnetic models and, although the original model used only linear chains, it has since been adapted to general networks. This model has a very rich transient, which has been used to model several aspects of elections, but its stationary states are always consensus states. In order to model more complex behaviors, we have, in a recent work, introduced the idea of biases and prejudices to the Sznajd model by generalizing the bounded confidence rule, which is common to many continuous opinion models, to what we called confidence rules. In that work we have found that the mean field version of this model (corresponding to a complete network) allows for stationary states where noninteracting opinions survive, but never for the coexistence of interacting opinions. In the present work, we provide networks that allow for the coexistence of interacting opinions for certain confidence rules. Moreover, we show that the model does not become inactive; that is, the opinions keep changing, even in the stationary regime. This is an important result in the context of understanding how a rule that breeds local conformity is still able to sustain global diversity while avoiding a frozen stationary state. We also provide results that give some insights on how this behavior approaches the mean field behavior as the networks are changed.

Nonempirical hyper-generalized-gradient functionals constructed from the Lieb-Oxford bound

A simple and completely general representation of the exact exchange-correlation functional of density-functional theory is derived from the universal Lieb-Oxford bound, which holds for any Coulomb-interacting system. This representation leads to an alternative point of view on popular hybrid functionals, providing a rationale for why they work and how they can be constructed. A similar representation of the exact correlation functional allows to construct fully nonempirical hyper-generalized-gradient approximations (HGGAs), radically departing from established paradigms of functional construction. Numerical tests of these HGGAs for atomic and molecular correlation energies and molecular atomization energies show that even simple HGGAs match or outperform state-of-the-art correlation functionals currently used in solid-state physics and quantum chemistry.

GENERALIZED FINITE ELEMENT METHOD FOR NONLINEAR THREE-DIMENSIONAL ANALYSIS OF SOLIDS

The Generalized Finite Element Method (GFEM) is employed in this paper for the numerical analysis of three-dimensional solids tinder nonlinear behavior. A brief summary of the GFEM as well as a description of the formulation of the hexahedral element based oil the proposed enrichment strategy are initially presented. Next, in order to introduce the nonlinear analysis of solids, two constitutive models are briefly reviewed: Lemaitre`s model, in which damage and plasticity are coupled, and Mazars`s damage model suitable for concrete tinder increased loading. Both models are employed in the framework of a nonlocal approach to ensure solution objectivity. In the numerical analyses carried out, a selective enrichment of approximation at regions of concern in the domain (mainly those with high strain and damage gradients) is exploited. Such a possibility makes the three-dimensional analysis less expensive and practicable since re-meshing resources, characteristic of h-adaptivity, can be minimized. Moreover, a combination of three-dimensional analysis and the selective enrichment presents a valuable good tool for a better description of both damage and plastic strain scatterings.