599 research outputs found

    The Fight or Flight Response: A Look at Stand Your Ground

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    In addressing the historical importance—or lack thereof—of the Stand Your Ground law, this article discusses the evolution of self-defense laws. Specific landmark cases are discussed as they relate to establishing the foundation of self-defense. The article also examines various issues that have been inherent within the Stand Your Ground debate. Statistical analysis of Stand Your Ground data from the State of Florida is conducted using binary logistic regression model to test the relationship between case outcomes and a number of other variables involving demographics, and the nature of the confrontation that led to the crim

    A high efficiency input/output coupler for small silicon photonic devices

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    Coupling light from an optical fibre to small optical waveguides is particularly problematic in semiconductors, since the refractive index of the silica fibre is very different from that of a semiconductor waveguide. There have been several published methods of achieving such coupling, but none are sufficiently efficient whilst being robust enough for commercial applications. In this paper experimental results of our approach called a Dual-Grating Assisted Directional Coupler, are presented. The principle of coupling by this novel method has been successfully demonstrated, and a coupling efficiency of 55% measured

    Artroplastia total no cementada en la coxartrosis secundaria a displasia y luxación congenita de cadera

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    Se revisan 13 prótesis no cementadas implantadas en 12 paciente s que presentaban una coxartrosis secundaria a una displasia congénita de cadera. Los paciente s han sido seguidos más de 2 años de evolución. En todos los casos se utilizó la via de abordaje postero-lateral. Se implantó siempre la prótesis tipo PCA procediéndose en 7 casos a la realización, a nivel acetabular, de un alo o autoinjerto complementario. A nivel femoral se utilizaron 7 vástagos estándar, 3 medianos y 3 largos para facilitar la restauración del centro rotatorio original de la cadera. En los pacientes que presentaban una luxación importante se llevaron a cabo osteotomías de acortamiento a nivel subtrocantérico. Los pacientes han sido evaluados pre y post-operatoriamente tanto desde el punto de vista radiográfico como clínico. Desde el punto de vista clínico, se obtuvieron 8 resultados excelentes, 3 buenos, 1 discreto y 1 malo. Todos los pacientes estaban plenamente satisfechos con el resultado de la operación habiendo aumentado drásticamente su nivel de actividad. Solamente en un caso fue necesario practicar una intervención de revisión a los 4 años de la artroplastia primitiva, a causa de una grave osificación periprotésica. Solamente se tuvo una complicación intraoperatoria consistente en una fractura de la diálisis femoral.Thirteen non-cemented hips prostheses implanted in 12 patients with an osteoartritis secundar y to congenita l dislocation and dysplasi a of the hip wer e reviewed . Patients had a more than 2 years follow-up. The postero-lateral surgical approach was employed in all cases. On the acetabular side, we always used the PCA socket type. On the femoral side we implanted a PCA standard stem in 7 cases, mid stem in 3 cases and a long stem in 3. Acetabular bone autograft was added in 7 patients. In order to restore the original center of rotacion of the hip, in patients with a severe dislocation we perfomed also a shortening sub-trochanteric osteotomy; all the patients wer e evaluated pre and post-operatively with two separate forms. The first regarding the clinical evaluation, the second for radiographic assessment. All the patients were fully satisfied with the operation increasing dramatically their activity level. We obtained 8 excellent results, 3 good, 1 fair and 1 poor. One case required a revision for a severe heterotopic bone formation about 4 years after the first implant. We had a diaphyseal femoral fracture as the sole inly an intraoperative complication

    Large Area Scene Selection Interface (LASSI). Methodology of Selecting Landsat Imagery for the Global Land Survey 2005

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    The Global Land Survey (GLS) 2005 is a cloud-free, orthorectified collection of Landsat imagery acquired during the 2004-2007 epoch intended to support global land-cover and ecological monitoring. Due to the numerous complexities in selecting imagery for the GLS2005, NASA and the U.S. Geological Survey (USGS) sponsored the development of an automated scene selection tool, the Large Area Scene Selection Interface (LASSI), to aid in the selection of imagery for this data set. This innovative approach to scene selection applied a user-defined weighting system to various scene parameters: image cloud cover, image vegetation greenness, choice of sensor, and the ability of the Landsat 7 Scan Line Corrector (SLC)-off pair to completely fill image gaps, among others. The parameters considered in scene selection were weighted according to their relative importance to the data set, along with the algorithm's sensitivity to that weight. This paper describes the methodology and analysis that established the parameter weighting strategy, as well as the post-screening processes used in selecting the optimal data set for GLS2005

    Subcutaneous Haemangiosarcoma in a Cockatiel ( Nymphicus hollandicus )

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74932/1/j.1439-0442.2006.00825.x.pd

    Tailoring the Response of Silicon Photonics Devices

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    Abstract: Shrinking waveguide dimensions in silicon photonics results in a series of performance enhancements, but at some cost. We analyse the waveguide geometry in optical modulators and filters to address some issues associated with this trend. Silicon photonics has experienced rapid development for the last three years and several significant results have been reported, demonstrating the viability of the technology [e.g., 1, 2, 3, 4]. One of the recent trends in silicon photonics has been the reduction of waveguide dimensions. This reduction facilitates tighter bending radii and therefore a smaller device footprint which in turn, significantly reduces the cost. Furthermore, technical performance of many silicon photonic devices is enhanced. However, there are also some issues with this trend to smaller dimensions, notably increased propagation losses, increased polarisation dependence and difficulty in coupling to/from optical fibres. These issues can be overcome with a careful design of the waveguide and device geometry. We have previously shown that by reducing waveguide dimensions, multi-GHz bandwidth optical modulators can be achieved by utilising a horizontal pn junction in a waveguide with an overall height of 450 nm In order to improve the polarisation performance to approach polarisation independence of the modulator, we propose here a modulator with a pn junction that is a V-shape structure, as shown in Highly doped silicon Silicon dioxide Highly doped silicon Highly doped silico

    Direct Observation of Martensitic Phase-Transformation Dynamics in Iron by 4D Single-Pulse Electron Microscopy

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    The in situ martensitic phase transformation of iron, a complex solid-state transition involving collective atomic displacement and interface movement, is studied in real time by means of four-dimensional (4D) electron microscopy. The iron nanofilm specimen is heated at a maximum rate of ∼10^(11) K/s by a single heating pulse, and the evolution of the phase transformation from body-centered cubic to face-centered cubic crystal structure is followed by means of single-pulse, selected-area diffraction and real-space imaging. Two distinct components are revealed in the evolution of the crystal structure. The first, on the nanosecond time scale, is a direct martensitic transformation, which proceeds in regions heated into the temperature range of stability of the fcc phase, 1185−1667 K. The second, on the microsecond time scale, represents an indirect process for the hottest central zone of laser heating, where the temperature is initially above 1667 K and cooling is the rate-determining step. The mechanism of the direct transformation involves two steps, that of (barrier-crossing) nucleation on the reported nanosecond time scale, followed by a rapid grain growth typically in ∼100 ps for 10 nm crystallites

    A Preparative Method for the Isolation and Fractionation of Dissolved Organic Acids from Bitumen-influenced Waters

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    The surface mining of oil sands north of Fort McMurray, Alberta produces considerable tailings waste that is stored in large tailings ponds on industrial lease sites. Viable strategies for the detoxification of oil sands process affected water (OSPW) are under investigation. In order to assess the toxic potential of the suite of dissolved organics in OSPW, a method for their extraction and fractionation was developed using solid phase extraction. The method successfully isolated organic compounds from 180 L of an aged OSPW source. Using acidic- or alkaline-conditioned non-polar ENV+ resin and soxhlet extraction with ethyl acetate and methanol, three fractions (F1–F3) were generated. Chemical characterization of the generated fractions included infusion to electrospray ionization ultrahigh-resolution mass spectrometry (ESI-UHRMS), liquid chromatography quadrupole time-of-flight mass spectrometry, gas chromatography triple quadrupole time-of-flight mass spectrometry, and synchronous fluorescence spectroscopy (SFS). Additionally, ESI-UHRMS class distribution data and SFS identified an increased degree of oxygenation and aromaticity, associated with increased polarity. Method validation, which included method and matrix spikes with surrogate and labelled organic mono carboxylic acid standards, confirmed separation according to acidity and polarity with generally good recoveries (average 76%). Because this method is capable of extracting large sample volumes, it is amenable to thorough chemical characterization and toxicological assessments with a suite of bioassays. As such, this protocol will facilitate effects-directed analysis of toxic components within bitumen-influenced waters from a variety of sources
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