Las tierras, los ganados, los trabajadores... Una posible reconstrucción de las estancias reduccionales de la experiencia jesuítica bonaerense, 1740-1752

El presente trabajo propone reconstruir el sistema productivo organizado por los misioneros de la Compañía de Jesús al sur de la jurisdicción colonial de Buenos Aires, entre 1740 y 1752. Si bien los hombres de la Compañía desarrollaron durante el siglo XVIII establecimientos productivos en todas las regiones rioplatenses, la característica de este caso se refiere a que la estancias y chacras que son descriptas tienen una vida activa de 12 años en la frontera, es decir, en territorio indígena ocupado por la reducciones pero con un dominio colonial no consolidado. Los espacios fronterizos no son habitados permanentemente por los españoles y la dominación y control del Estado suelen ser esporádicos. Por tanto, la experiencia misional se transforma en un mecanismo que pretende vigilar y controlar, pero que para existir en un territorio cuyo dominio es detentado por otras sociedades debe negociar con las mismas sus condiciones de existencia. ¿Cómo afectó esta situación a la constitución de ┤chacras' y ┤estancias' productivas? ¿En qué medida estos establecimientos se integraron a la red de establecimientos que la Compañía posee en tierras ┤españolas'? ¿La organización es similar en el ámbito fronterizo y en el ámbito ┤efectivamente' colonizado?

Las tierras, los ganados, los trabajadores... Una posible reconstrucción de las estancias reduccionales de la experiencia jesuítica bonaerense, 1740-1752

El presente trabajo propone reconstruir el sistema productivo organizado por los misioneros de la Compañía de Jesús al sur de la jurisdicción colonial de Buenos Aires, entre 1740 y 1752. Si bien los hombres de la Compañía desarrollaron durante el siglo XVIII establecimientos productivos en todas las regiones rioplatenses, la característica de este caso se refiere a que la estancias y chacras que son descriptas tienen una vida activa de 12 años en la frontera, es decir, en territorio indígena ocupado por la reducciones pero con un dominio colonial no consolidado. Los espacios fronterizos no son habitados permanentemente por los españoles y la dominación y control del Estado suelen ser esporádicos. Por tanto, la experiencia misional se transforma en un mecanismo que pretende vigilar y controlar, pero que para existir en un territorio cuyo dominio es detentado por otras sociedades debe negociar con las mismas sus condiciones de existencia. ¿Cómo afectó esta situación a la constitución de ┤chacras' y ┤estancias' productivas? ¿En qué medida estos establecimientos se integraron a la red de establecimientos que la Compañía posee en tierras ┤españolas'? ¿La organización es similar en el ámbito fronterizo y en el ámbito ┤efectivamente' colonizado?

Las tierras, los ganados, los trabajadores... Una posible reconstrucción de las estancias reduccionales de la experiencia jesuítica bonaerense, 1740-1752

El presente trabajo propone reconstruir el sistema productivo organizado por los misioneros de la Compañía de Jesús al sur de la jurisdicción colonial de Buenos Aires, entre 1740 y 1752. Si bien los hombres de la Compañía desarrollaron durante el siglo XVIII establecimientos productivos en todas las regiones rioplatenses, la característica de este caso se refiere a que la estancias y chacras que son descriptas tienen una vida activa de 12 años en la frontera, es decir, en territorio indígena ocupado por la reducciones pero con un dominio colonial no consolidado. Los espacios fronterizos no son habitados permanentemente por los españoles y la dominación y control del Estado suelen ser esporádicos. Por tanto, la experiencia misional se transforma en un mecanismo que pretende vigilar y controlar, pero que para existir en un territorio cuyo dominio es detentado por otras sociedades debe negociar con las mismas sus condiciones de existencia. ¿Cómo afectó esta situación a la constitución de ┤chacras' y ┤estancias' productivas? ¿En qué medida estos establecimientos se integraron a la red de establecimientos que la Compañía posee en tierras ┤españolas'? ¿La organización es similar en el ámbito fronterizo y en el ámbito ┤efectivamente' colonizado?

Inferior visual field reductions are associated with poorer functional status among older adults with glaucoma

Purpose: To examine the relationship between visual impairment and functional status in a community-dwelling sample of older adults with glaucoma. Methods: This study included 74 community-dwelling older adults with open-angle glaucoma (aged 74 ± 6 years). Assessment of central vision included high-contrast visual acuity and Pelli-Robson contrast sensitivity. Binocular integrated visual fields were derived from merged monocular Humphrey Field Analyser visual field plots. Functional status outcome measures included physical performance tests (6-min walk test, timed up and go test and lower limb strength), a physical activity questionnaire (Physical Activity Scale for the Elderly) and an overall functional status score. Correlation and linear regression analyses, adjusting for age and gender, examined the association between visual impairment and functional status outcomes. Results: Greater levels of visual impairment were significantly associated with lower levels of functional status among community-dwelling older adults with glaucoma, independent of age and gender. Specifically, lower levels of visual function were associated with slower timed up and go performance, weaker lower limb strength, lower self-reported physical activity, and lower overall functional status scores. Of the components of vision examined, the inferior visual field and contrast factors were the strongest predictors of these functional outcomes, whereas the superior visual field factor was not related to functional status. Conclusions: Greater visual impairment, particularly in the inferior visual field and loss of contrast sensitivity, was associated with poorer functional status among older adults with glaucoma. The findings of this study highlight the potential links between visual impairment and the onset of functional decline. Interventions which promote physical activity among older adults with glaucoma may assist in preventing functional decline, frailty and falls, and improve overall health and well-being.

Tuning the reduction power of supported gold nanoparticle photocatalysts for selective reductions by manipulating wavelength of visible light irradiation

Gold nanoparticles supported on CeO2 were found to be efficient photocatalysts for three selective reductions of organic compounds at ambient temperatures, under irradiation of visible light; their reduction ability can be tuned by manipulating the irradiation wavelength.

Selective reductions using visible light photocatalysts of supported gold nanoparticles

Photocatalytic synthesis using visible light is a desirable chemical process because of its potential to utilize sunlight. Supported gold nanoparticles (Au-NPs) were found to be efficient photocatalysts and the effects of the supports were identified including CeO2, TiO2, ZrO2, Al2O3, and zeolite Y. In particular Au/CeO2 exhibited the high catalytic activity to reduce nitroaromatics to azo compounds, hydrogenate azobenzene to hydroazobenzene, reduce ketones to alcohols, and deoxygenate epoxides to alkenes at ambient temperatures, under irradiation of visible light (or simulated sunlight). The reac-tive efficiency depends on two primary factors: one is the light adsorption of catalysts and another is the driving ability of catalysts corresponding to the reactants. The light absorption by Au-NPs is due to surface plasmon resonance effect or inter-band electron transition; this is related to the reduction ability of the photocatalysts. Irradiation with shorter wavelengths can excite the conduction electrons in Au-NPs to higher energy levels and as a result, induce reduction with more negative reduction potentials. It is known when irradiated with light the Au-NPs can abstract hydrogen from isopropanol forming Au-H species on the Au-NP surface. Hence, we proposed that the active Au-H species will react with the N=O, N=N, C=O double bonds or epoxide bonds, which are weakened by the interaction with the excited electrons in the Au-NPs, and yield the final reductive products. The reacting power of the Au-H species depends on the energy of the excited electrons in Au-NPs: the higher the electronic energy, the stronger the reduction ability of the Au-H species. This finding demonstrates that we can tune the reduction ability of the photocatalysts by manipulating the irradiation wavelength.

A simple computational model for predicting .pi.-facial selectivity in reductions of sterically unbiased ketones. Relative importance of electrostatic and orbital interactions

Various factore controlling the preferred facial selectivity in the reductions of a number of sterically unbiased ketones have been evaluated using a semiempirical MO procedure. MNDO optimized geometries do not reveal any significant ground-state distortions which can be correlated with the observed face selectivities. Electrostatic effecta due to an approaching reagent were modeled by placing a test negative charge at a fixed distance from the carbonyl carbon on each of the two faces. A second series of calculations was carried out using the hydride ion as a test nucleophile. The latter calculations effectively include orbital interactions involving the u and u* orbitals of the newly formed bond in the reaction. The computed energy differences with the charge model are generally much larger compared to those with the hydride ion. However, both models lead to predictions which are qualitatively consistent with the experimentally determined facial preferences for most of the systems. Thus, electrostatic interactions between the nucleophile and the substrate seem to effectively determine the face selectivities in these molecules. However, there are a few exceptions in which orbital interactions are found to contribute significantly and occasionally reverse the preference dictated by electrostatic effecta. The remarkable succew of the hydride model calculations, in spite of retaining the unperturbed geometries of the substrates, points to the unimportance of torsional effeds and orbital distortions associated with the pyramidalized carbonyl unit in the transition state in most of the substrates considered. Additional experimental results are reported which provide useful calibration for the present computational approach.

Multiple scales without center manifold reductions for delay differential equations near Hopf bifurcations

We study small perturbations of three linear Delay Differential Equations (DDEs) close to Hopf bifurcation points. In analytical treatments of such equations, many authors recommend a center manifold reduction as a first step. We demonstrate that the method of multiple scales, on simply discarding the infinitely many exponentially decaying components of the complementary solutions obtained at each stage of the approximation, can bypass the explicit center manifold calculation. Analytical approximations obtained for the DDEs studied closely match numerical solutions.

How much efficiency gains and price reductions for an efficiency defense? 'Quanto Basta'

Potential efficiency gains due to a merger can be used by competition authorities to judge upon proposed mergers. In a world where agents’ efforts, observable or unobservable, affect the success of a production cost reducing project that may be conducted as a stand-alone firm or in a merger, we characterize the merger decision and the type of errors a competition authority may make when it relies on an efficiency defense. In addition, we show that the occurrence of either type of errors is always smaller under the unobservable efforts assumption, than under the observable efforts one.

Rapid and parallel chromosomal number reductions in muntjac deer inferred from mitochondrial DNA phylogeny

Muntjac deer (Muntiacinae, Cervidae) are of great interest in evolutionary studies because of their dramatic chromosome variations and recent discoveries of several new species. In this paper, we analyze the evolution of karyotypes of muntjac deer in the context of a phylogeny which is based on 1,844-bp mitochondrial DNA sequences of seven generally recognized species in the muntjac subfamily. The phylogenetic results support the hypothesis that karyotypic evolution in muntjac deer has proceeded via reduction in diploid number. However, the reduction in number is not always linear, i.e., not strictly following the order: 46-->14/13-->8/9-->6/7. For example, Muntiacus muntjak (2n = 6/7) shares a common ancestor with Muntiacus feae (2n = 13/14), which indicates that its karyotype was derived in parallel with M. feae's from an ancestral karyotype of 2n greater than or equal to 13/14. The newly discovered giant muntjac (Muntiacus vuquangensis) may represent another pa;allel reduction lineage from the ancestral 2n = 46 karyotype. Our phylogenetic results indicate that the giant muntjac is relatively closer to Muntiacus reevesi than to other muntjacs and may be placed in the genus Muntiacus. Analyses of sequence divergence reveal that the rate of change in chromosome number in muntjac deer is one of the fastest in vertebrates. Within the muntjac subfamily, the fastest evolutionary rate is found in the Fea's lineage, in which two species with different karyotypes diverged in around 0.5 Myr.

Model reductions for inference: generality of pairwise, binary, and planar factor graphs.

We offer a solution to the problem of efficiently translating algorithms between different types of discrete statistical model. We investigate the expressive power of three classes of model-those with binary variables, with pairwise factors, and with planar topology-as well as their four intersections. We formalize a notion of "simple reduction" for the problem of inferring marginal probabilities and consider whether it is possible to "simply reduce" marginal inference from general discrete factor graphs to factor graphs in each of these seven subclasses. We characterize the reducibility of each class, showing in particular that the class of binary pairwise factor graphs is able to simply reduce only positive models. We also exhibit a continuous "spectral reduction" based on polynomial interpolation, which overcomes this limitation. Experiments assess the performance of standard approximate inference algorithms on the outputs of our reductions.