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Journals and Conferences
Optical channel waveguides have been obtained by electric?field?assisted diffusion of copper films on glass substrates. The mode indices of these channel waveguides were determined with the prism?coupling technique, and the refractive?index profile of the waveguide was reconstructed from measurements of the near?field intensity distribution.
Increases in species diversity and density from higher to lower latitudes are well documented. Nevertheless, the consequences of these changes in diversity for structuring ecological communities and influencing biotic evolution are largely unknown. It is widely believed that this increase in species diversity is associated with increased intensity of… (More)
Directed dispersal occurs when seeds are differentially deposited to sites where offspring survivorship is higher than at randomly chosen sites. Traditionally, characteristics of the dispersal target sites that could increase survivorship of the dispersed plants are thought to be intrinsic to the sites. If directed dispersal is constant over extended… (More)
INTRODUCTION Information concerning to triatomine diversity and some eco-epidemiologic aspects on Margarita Island has been recorded only from two of the five counties on the island. Knowledge about species habitat and their natural infection is essential to establish the risk for Chagas disease in endemic areas. OBJECTIVE The distribution of triatomine… (More)
Community ecologists have strived to find mechanisms that mediate the assembly of natural communities. Recent evidence suggests that natural enemies could play an important role in the assembly of hyper-diverse tropical plant systems. Classic ecological theory predicts that in order for coexistence to occur, species differences must be maximized across… (More)
An experimental study about four optical setups used for developing a Focused IR Light Soldering System (FILSS) for Surface Mount Technology (SMT) lead-free electronic devices specifically for Ball Grid Arrays (BGA) is presented. An analysis of irradiance and infrared thermography at BGA surface is presented, as well as heat transfer by radiation and… (More)
The sensitivity of the interferometric techniques to longitudinal variations of the optical path can be increased by introducing carrier fringes. A new method for introducing such fringes is presented.
Fifty years ago, Ehrlich and Raven proposed that insect herbivores have driven much of plant speciation, particularly at tropical latitudes. There have been no explicit tests of their hypotheses. Indeed there were no proposed mechanisms either at the time or since by which herbivores might generate new plant species. Here we outline two main classes of… (More)
Optical waveguides have been obtained by field-assisted Cu(+)-Na(+) exchanged on glass. The refractive index profiles of the waveguides are determined by means of the prism-coupling technique and Chiang's method [J. Lightwave Technol. LT-3, 385 (1985)], and they correlate with the index profile calculated as a function of the glass composition. The… (More)