Rhetorical analysis of Sunoco, Inc. chairman and chief executive officer address to the World Fuels Conference : Requirements for Economic and Environmental Competitiveness in the 21st Century

The present thesis examines the rhetorical dimensions of the speech presented by Sunoco, inc. Chairman and Executive Officer before the World Fuels Conference held in Washington DC, October 23, 1997. The focus of the thesis is to examine the effectiveness of the speech. Principles of rhetoric were explained and applied to evaluate the effectiveness of the speech as a means of persuasion. The rhetorical analysis of the speech illustrates how language can be used as a symbolic means of inducing cooperation from individuals

Stern-Gerlach Entanglement in Spinor Bose-Einstein Condensates

Entanglement of spin and position variables produced by spatially inhomogeneous magnetic fields of Stern-Gerlach type acting on spinor Bose-Einstein condensates may lead to interference effects at the level of one-boson densities. A model is worked out for these effects which is amenable to analytical calculation for gaussian shaped condensates. The resulting interference effects are sensitive to the spin polarization properties of the condensate.Comment: 9 pages, 2 figure

Interrupción de Aferencias propioceptivas a nivel de la segunda neurona inducen escoliosis: Estudio experimental en ratas

El propósito de este trabajo es valorar el comportamiento del raquis, en un modelo experimental con ratas, tras producir una lesión a nivel del núcleo gracilis. Un total de 20 animales de 5 semanas de edad fueron usados en nuestro estudio. Las lesiones fueron realizadas en el lado derecho. Del total de 15 animales con lesión, todos presentaron lesión histológica, 5 de estos desarrollaron curvas escolióticas (33.3%) con una media de 14.8-Cobb (9-20) y cifosis de 40.4-Cobb (38-42). Nuestros datos sugieren que el núcleo gracilis puede estar implicado de algún modo en el desarrollo de la escoliosis.The aim of this study wa s to investigate if damage of gracilis nucleus could bring about scoliotic deformitie. A total of 20 animals aged 5 weeks wer e used in this experiment. Lesions wer e performed on the right side. Out of 15 brain damaged animals, 15 had accurat e histological lesions, 5 of these (33.3%) developed scoliotic curve s with a mean Cobb's angle 14. 8 (range: 8-20) and Kyphosis with a mean Cobb's angle 40.4 (range: 38-42). This study provide s the expiremental support that gracilis nucleus can be a primary etiology factor in idiophatic scoliosis

Trophic cascades and the transient keystone concept

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordApex predator reintroductions are commonly motivated by the imperative to restore populations and wider ecosystem function by precipitating trophic cascades that release basal species. Yet evidence for the existence of such cascades is often equivocal, particularly where consumptive interactions between apex and intermediate predators are weak or absent. Here, using a tri-trophic skate-crab-bivalve study-system, we find that non-consumptive interactions between apex skate and intermediate crabs cascade down to consumptive interactions between crabs and bivalves, significantly reducing bivalve mortality. However, skate only functioned as keystone where crabs foraged for bivalves in the absence of mature bivalve reef: where reef was present, bivalve mortality was not significantly different in the presence or absence of skate. By facilitating the establishment of basal species which, in turn, diminish apex-intermediate effects, the skate's keystone function is subject to negative regulation. Thus, we propose that keystone functionality can be transient with respect to environmental context. Our findings have two central implications for apex predator reintroductions and basic ecology: (i) species hitherto not considered as keystone may have the capacity to act as such transiently, and; (ii) keystones are known to regulate ecosystems, but transience implies that ecosystems can regulate keystone function.Natural Environment Research Council (NERC

Fiabilidad diagnóstica comparativa de la mielografía y de la tomografía axial computarizada en la hernia discal lumbar

Un grupo de 137 pacientes con hernia discal lumbar fue estudiado retrospectivamente , contrastando los hallazgos quirúrgicos con los proporcionado s por la mielografía y la tomografía axial computarizada (TAC), con objeto de comparar la fiabilidad de ambas técnicas de diagnóstico. La hernia discal correspondió al nivel L5-S1 en 76 pacientes y al L4-L5 en 61. Preoperatoriamente se había efectuado una TAC lumbar en 99 paciente s y una mielografía en 77. En 39 casos se efectuaron ambas exploraciones. La fiabilidad diagnóstica cuantificada por el porcentaje de resultados "verdaderos positivos" fue similar en ambas exploraciones, elevándose al 89% y 90% para la TAC y la mielografía respectivamente . De los 39 paciente s a quiene s se le s practicó ambas exploraciones, en 12 (39%) de ellos no existía concordancia en el diagnóstico. No se registraron "falsos negativos" con la TAC. Como conclusión, ambas técnicas diagnósticas tienen una alta y similar fiabilidad para detectar hernias discale s a nivel lumbar. No obstante, las ventajas que aporta la TAC respecto a la mielografía en cuanto a confort para el pacient e y ausencia de reaccione s adversas hac e que esta técnica sea considerada como el método diagnóstico de elección. La mielografía queda relegada a casos con imágene s dudosas con la TAC.In orde r to compar e the diagnosti c accurac y of CT sca n and myelo - graphy, a series of 137 patients with herniated lumbar disc was retrospectively analyzed matching the surgical findings with the images obtained by both diagnostic techniques. Ther e wer e 7 6 herniate d disc s a t th e L5-S1 leve l an d 6 1 a t th e L4-L5. Preoperatively, 99 patients wer e assessed by CT scan and 77 by mielography. In 39 cases, both technique s wer e performed. The diagnosti c accuracy, quantified by the percentage of "true positive" results wa s similar in both techniques: 89% in CT scan and 90% in mielography . In 12 of the 39 patients explore d by bot h CT scan and myelo - graphy, the results wer e discordant. "False negative" case s wer e not found using CT scan. In conclusion, both CT scan and myelography provide equal high diagnosti c accuracy for lumbar herniated disc. However, CT scan has become the primary diagnostic tool because of several advantages, such as the confort for the patients and the lack of adverse reactions