474 research outputs found

    Imaging characteristics and treatment of a penetrating brain injury caused by an oropharyngeal foreign body in a dog

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    A 4-year-old Border collie was presented with one episode of collapse, altered mentation, and a suspected pharyngeal stick injury. Magnetic resonance imaging (MRI) and computed tomography showed a linear foreign body penetrating the right oropharynx, through the foramen ovale and the brain parenchyma. The foreign body was surgically removed and medical treatment initiated. Complete resolution of clinical signs was noted at recheck 8 weeks later. Repeat MRI showed chronic secondary changes in the brain parenchyma. To the authors' knowledge, this is the first report of the advanced imaging findings and successful treatment of a penetrating oropharyngeal intracranial foreign body in a dog

    Extended-SWIR High-Speed All-GeSn PIN Photodetectors on Silicon

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    There is an increasing need for silicon-compatible high bandwidth extended-short wave infrared (e-SWIR) photodetectors (PDs) to implement cost-effective and scalable optoelectronic devices. These systems are quintessential to address several technological bottlenecks in detection and ranging, surveillance, ultrafast spectroscopy, and imaging. In fact, current e-SWIR high bandwidth PDs are predominantly made of III-V compound semiconductors and thus are costly and suffer a limited integration on silicon besides a low responsivity at wavelengths exceeding 2.3μ2.3 \,\mum. To circumvent these challenges, Ge1x_{1-x}Snx_{x} semiconductors have been proposed as building blocks for silicon-integrated high-speed e-SWIR devices. Herein, this study demonstrates a vertical all-GeSn PIN PDs consisting of p-Ge0.92_{0.92}Sn0.08_{0.08}/i-Ge0.91_{0.91}Sn0.09_{0.09}/n-Ge0.89_{0.89}Sn0.11_{0.11} and p-Ge0.91_{0.91}Sn0.09_{0.09}/i-Ge0.88_{0.88}Sn0.12_{0.12}/n-Ge0.87_{0.87}Sn0.13_{0.13} heterostructures grown on silicon following a step-graded temperature-controlled epitaxy protocol. The performance of these PDs was investigated as a function of the device diameter in the 1030μ10-30 \,\mum range. The developed PD devices yield a high bandwidth of 12.4 GHz at a bias of 5V for a device diameter of 10μ10 \,\mum. Moreover, these devices show a high responsivity of 0.24 A/W, a low noise, and a 2.8μ2.8 \,\mum cutoff wavelength thus covering the whole e-SWIR range

    Liver Parasites and Body Condition in Relation to Environmental Contaminants in Caribou (Rangifer tarandus) from Labrador, Canada

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    Over the last several decades, elders and hunters of the Innu Nation in Labrador, Canada, have expressed concerns over perceived declines in environmental health and the integrity of country food, including caribou. The primary objective of this study was to determine links between specific health parameters and contaminants found in caribou from the George River herd. Twenty-seven caribou killed by local Innu hunters between February and December 2001 were evaluated for gross and microscopic pathology, body condition, liver parasitology, and contaminant levels in kidney and fat. Overall, the sampled caribou appeared to be in adequate body condition for the time of year, and no clinically significant lesions were found. Concentrations of selenium, metals (Hg, Cd, and Pb), 20 organochlorine pesticides (HCB, a-HCH, g-HCH, aldrin, dieldrin, methoxychlor, mirex, a- and b-endosulfan, heptachlor, heptachlor epoxide, g-CHL, cis-CHL, trans-nonachlor, and o,p'- and p,p'-DDD, DDE, DDT), and 24 PCB congeners were within the ranges reported for caribou in Canada. In general, contaminant levels were relatively low, with the exception of cadmium in kidneys (geometric mean: 6.5 μg/g wet weight; range: 1.5–44.0 μg/g). Two types of liver parasites were found: the liver fluke Fascioloides magna (prevalence: 78%; geometric mean abundance: 4.2 flukes/caribou) and a tapeworm larva consistent with Taenia hydatigena (prevalence: 50%; geometric mean abundance: 0.6 larvae/caribou). Using multiple variable regression analysis, we found renal concentrations of cadmium to be positively associated, and selenium to be negatively associated, with F. magna abundance.Ces dernières décennies, les aînés et les chasseurs de la nation montagnaise du Labrador, au Canada, ont exprimé des inquiétudes au sujet du déclin de la santé de l’environnement et de l’intégrité de la nourriture provenant de la campagne, telle que le caribou. L’objectif principal de cette étude consistait à déterminer les liens qui existent entre certains paramètres de santé précis et les contaminants se trouvant dans le caribou du troupeau de la rivière George. Vingt-sept caribous ayant été tués par les chasseurs montagnais de la région entre les mois de février et de décembre 2001 ont subi des examens pathologiques macroscopiques et microscopiques, en plus d’avoir été évalués pour en déterminer l’état du corps, la parasitologie du foie et les taux de contaminants dans le foie et le gras. Dans l’ensemble, l’état des corps de caribous échantillonnés semblait adéquat pour cette période de l’année et aucune lésion clinique importante n’a été signalée. Les concentrations de sélénium, de métaux (Hg, Cd et Pb), de 20 pesticides organochlorés (HCB, a-HCH, g-HCH, aldrine, dieldrine, méthoxychlore, mirex, a- et b-endosulfane, heptachlore, heptachlorépoxyde, g-CHL, cis-CHL, trans-nonachlore ainsi que o,p'- et p,p'-DDD, DDE, DDT) et de 24 congénères de PCB s’établissaient dans les étendues signalées pour le caribou au Canada. En général, les niveaux de contaminants étaient relativement faibles, à l’exception du cadmium se trouvant dans les reins (moyenne géometrique : 6,5 μg/g poids humide; étendue : 1,5–44,0 mg/g). Deux types de parasites du foie ont été trouvés : la douve Fascioloides magna (prévalence : 78 %; abondance moyenne géométrique : 4,2 douves/caribou) et un cestode du genre Taenia hydatigena (prévalence : 50 %; abondance moyenne géométrique : 0,6 larves/caribou). Nous avons également réalisé une analyse de régression à variables multiples qui nous a permis de constater que les concentrations de cadmium sont positivement associées et celles de sélénium sont négativement associées à l’abondance de F. magna
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