Ecoturismo en comunidades rurales: análisis de los impactos negativos para la población local. Un estudio de caso

En los últimos años han aparecido nuevas formas de turismo más sostenibles, donde existen elementos relacionados con el descanso, el disfrute y la protección del medio ambiente o el conocimiento de la cultura local, a través de políticas que favorecen la sostenibilidad del destino. En este sentido, el ecoturismo se configura como una tipología turística que se desarrolla en contacto con la naturaleza. Este turismo ayuda a mejorar el desarrollo socioeconómico de las comunidades locales, a la vez, que fomenta la conservación de los recursos naturales y el respeto hacia el medio ambiente. Aunque, esta tipología de turismo también genera importantes impactos negativos. El objetivo principal de esta investigación es analizar los impactos socioeconómicos, culturales y medioambientales percibidos por el ecoturismo por parte de los residentes de comunidades rurales de República Dominicana. La técnica de recolección de datos utilizada ha consistido en un cuestionario. Entre las principales conclusiones, cabe destacar que actualmente no se perciben impactos negativos, pero si hay una serie de elementos que hay que ir considerando, con la finalidad de que no se conviertan en un impacto a corto plazo para la comunidad rural.

Local and semilocal density functional computations for crystals of 1-alkyl-3-methyl-imidazolium salts

The accuracy and reliability of popular density functional approximations for the compounds giving origin to room temperature ionic liquids have been assessed by computing the T=0 K crystal structure of several 1-alkyl-3-methyl-imidazolium salts. Two prototypical exchange-correlation approximations have been considered, i.e., the local density approximation (LDA) and one gradient corrected scheme [PBE-GGA, Phys. Rev. Lett. 77, 3865 (1996)]. Comparison with low-temperature x-ray diffraction data shows that the equilibrium volume predicted by either approximations is affected by large errors, nearly equal in magnitude (~10%), and of opposite sign. In both cases the error can be traced to a poor description of the intermolecular interactions, while the intramolecular structure is fairly well reproduced by LDA and PBE-GGA. The PBE-GGA optimization of atomic positions within the experimental unit cell provides results in good agreement with the x-ray structure. The correct system volume can also be restored by supplementing PBE-GGA with empirical dispersion terms reproducing the r-6 attractive tail of the van der Waals interactions.

An analogue of the Magnus problem for associative algebras

We prove an analogue of Magnus theorem for associative algebras without unity over arbitrary fields. Namely, if an algebra is given by $n+k$ generators and $k$ relations and has an $n$-element system of generators, then this algebra is a free algebra of rank $n$.

Nonlinear PCA with Local Approach for Diesel Engine Fault Detection and Diagnosis

This brief examines the application of nonlinear statistical process control to the detection and diagnosis of faults in automotive engines. In this statistical framework, the computed score variables may have a complicated nonparametric distri- bution function, which hampers statistical inference, notably for fault detection and diagnosis. This brief shows that introducing the statistical local approach into nonlinear statistical process control produces statistics that follow a normal distribution, thereby enabling a simple statistical inference for fault detection. Further, for fault diagnosis, this brief introduces a compensation scheme that approximates the fault condition signature. Experimental results from a Volkswagen 1.9-L turbo-charged diesel engine are included.