Change in Mesoherbivore Browsing Is Mediated by Elephant and Hillslope Position

Elephant are considered major drivers of ecosystems, but their effects within small-scale landscape features and on other herbivores still remain unclear. Elephant impact on vegetation has been widely studied in areas where elephant have been present for many years. We therefore examined the combined effect of short-term elephant presence (< 4 years) and hillslope position on tree species assemblages, resource availability, browsing intensity and soil properties. Short-term elephant presence did not affect woody species assemblages, but did affect height distribution, with greater sapling densities in elephant access areas. Overall tree and stem densities were also not affected by elephant. By contrast, slope position affected woody species assemblages, but not height distributions and densities. Variation in species assemblages was statistically best explained by levels of total cations, Zinc, sand and clay. Although elephant and mesoherbivore browsing intensities were unaffected by slope position, we found lower mesoherbivore browsing intensity on crests with high elephant browsing intensity. Thus, elephant appear to indirectly facilitate the survival of saplings, via the displacement of mesoherbivores, providing a window of opportunity for saplings to grow into taller trees. In the short-term, effects of elephant can be minor and in the opposite direction of expectation. In addition, such behavioural displacement promotes recruitment of saplings into larger height classes. The interaction between slope position and elephant effect found here is in contrast with other studies, and illustrates the importance of examining ecosystem complexity as a function of variation in species presence and topography. The absence of a direct effect of elephant on vegetation, but the presence of an effect on mesoherbivore browsing, is relevant for conservation areas especially where both herbivore groups are actively managed.

An electrokinetic sensor for studying immersed surfaces, using focused ultrasound

A novel method for obtaining information on the charge density of an immersed surface is presented. The technique uses focused ultrasound to excite oscillatory fluid motion in the plane of the solid-liquid interface, over a localised area. The displacement current (resulting from the motion of fluid-borne ions in the outer double-layer) is detected by electrodes in the liquid. The method is demonstrated as a means for monitoring protein adsorption, and for monitoring interactions between two different proteins. A second electrokinetic effect at the interface is identified, isolated from the first, and shown to provide additional information on the compressibility and charge density of the double-layer. © 2001 Elsevier Science B.V. All rights reserved.

Integration of holographic sensors into microfluidics for the real-time pH sensing of L. casei metabolism

We describe developments in the integration of analyte specific holographic sensors into PDMS-based microfluidic devices for the purpose of continuous, low-impact monitoring of extra-cellular change in micro-bioreactors. Holographic sensors respond to analyte concentration via volume change, which makes their reduction in size and integration into spatially confined fluidics difficult. Through design and process modification many of these constraints have been addressed, and a microfluidics-based device capable of real-time monitoring of the pH change caused by Lactobacillus casei fermentation is presented as a general proof-of-concept for a wide array of possible devices.

Probing biomolecular interaction forces using an anharmonic acoustic technique for selective detection of bacterial spores.

Receptor-based detection of pathogens often suffers from non-specific interactions, and as most detection techniques cannot distinguish between affinities of interactions, false positive responses remain a plaguing reality. Here, we report an anharmonic acoustic based method of detection that addresses the inherent weakness of current ligand dependant assays. Spores of Bacillus subtilis (Bacillus anthracis simulant) were immobilized on a thickness-shear mode AT-cut quartz crystal functionalized with anti-spore antibody and the sensor was driven by a pure sinusoidal oscillation at increasing amplitude. Biomolecular interaction forces between the coupled spores and the accelerating surface caused a nonlinear modulation of the acoustic response of the crystal. In particular, the deviation in the third harmonic of the transduced electrical response versus oscillation amplitude of the sensor (signal) was found to be significant. Signals from the specifically-bound spores were clearly distinguishable in shape from those of the physisorbed streptavidin-coated polystyrene microbeads. The analytical model presented here enables estimation of the biomolecular interaction forces from the measured response. Thus, probing biomolecular interaction forces using the described technique can quantitatively detect pathogens and distinguish specific from non-specific interactions, with potential applicability to rapid point-of-care detection. This also serves as a potential tool for rapid force-spectroscopy, affinity-based biomolecular screening and mapping of molecular interaction networks.

Alma, cuerpo y mente : Santo Tomás y algunos contemporáneos

No necesitamos justificar la actualidad del problema mente-cuerpo en una parte importante de la filosofía contemporánea. Puede decirse que el nacimiento oficial del asunto se remonta a dos artículos pioneros aparecidos en 1958 y en 1959 escritos por Herbert Feigl el primero y J.J.C. Smart el segundo. Se trata de un asunto planteado en buena medida a partir de los descubrimientos en materia de anatomía y fisiología cerebral y de la relevancia del funcionamiento del cerebro en los actos mentales. Sin ánimo de simplificar excesivamente, puede decirse que las neurociencias se proponen hallar en la complejidad de la organización cerebral la explicación fundamental de la mente misma, e incluso de los actos humanos.

[Discurso do Deputado Castro Costa : Sessão da Câmara dos Deputados de 08 de novembro de 1962]

Comenta o discurso do Deputado Herbert Levy em relação às condições de funcionamento da administração pública em Brasília e em relação a críticas feitas ao Senador Pedro Ludovico. Declara ser impossível admitir o retorno da capital do país para o Rio de Janeiro.

Diário da Constituinte [gravação de vídeo] : [programa n. 502 ]

A constituinte começa a votar as mudanças no poder judiciário. Portadores do vírus HIV levam apelo ao Congresso. O presidente da Associação Brasileira Interdisciplinar da AIDS, Herbert de Souza, se reuniu com líderes de diversos partidos e apresentou um projeto de lei que puni com a prisão o doador que fizer doação de sangue sabendo que é portador do vírus HIV. Ele sugeriu também que atividades hemoterápicas sejam exercidas sem fins lucrativos, além de punição aos hospitais que se recusarem a atender pessoas soropositivas. A constituinte começou a votar todo o capítulo sobre o poder judiciário. A constituinte começou a votar o capítulo do Poder Judiciário. Existem algumas mudanças nesse capítulo como: o habeas data, mandado de injunção e o mandato de segurança coletivo. Alguns constituintes querem outras mudanças. Como o constituinte Paulo Pimentel que quer alterar o atual projeto de constituição no artigo em que se cria o Conselho Nacional de Justiça. Para ele esse conselho deveria ser suprimido. A sessão começou com a votação do substitutivo de Centrão sobre Poder Judiciário. O texto foi aprovado sem maiores discussões, graças a um acordo de lideranças. Foram 359 votos a favor e 10 contra. A primeira emenda a ser votada foi a do constituinte Oswaldo Trevisan que propõe a federalização da justiça. Mas a emenda acabou sendo rejeitada. Foi aprovada a emenda que propõe que o ingresso na carreira judiciária aconteça por meio do cargo de juiz substituto e de concurso público. Essa proposta foi feita pelos deputados Nelson Aguiar e Konder Reis. A sessão continuará ao longo da noite, sendo que quase todas as emendas que tratam do Poder Judiciário poderão ser votadas.