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S S Kroll M A Schusterman D L Larson A Fender 《Plastic and reconstructive surgery》1990,86(4):697-701
Reconstruction of chest-wall defects with musculocutaneous flaps permits resection of advanced chest-wall tumors and of tissues severely damaged by radiotherapy in patients who in a previous era were not surgically treatable. To determine the long-term outcome from this surgery, the records of 96 patients who had undergone chest-wall resection with musculocutaneous flap reconstruction were reviewed. Median survival for the entire group was 20.5 months, but a more accurate prediction of outcome could be obtained by dividing the patients into three groups. In group I, patients free of known malignancy and undergoing resection of radionecrotic tissues, median survival was 60.0 months. In group II, patients with resectable disease and free of tumor following surgery, median survival was 31.1 months. In group III, patients incompletely resected or known to have metastatic disease following surgery, median survival was only 12.5 months. Even in group III, however, some individuals achieved prolonged survival and lasting benefits from the surgery, so these data should not be used to exclude patients from undergoing necessary palliative procedures. 相似文献
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Anthropologists have long been interested in missionization, acculturation, and political subjugation of traditional peoples. In recent years scholars have generated voluminous amounts of data on Spanish colonialism and its effects on the native population of the Americas. This article specifically examines the missionization of the Chumash occupying the coastal region of central California. Although the abandonment of Chumash villages occurred over a 40-year period, the vast majority of the Chumash people—over 85 percent—migrated to the missions between 1786 and 1803. We suggest that the decision to move to the missions may have been based on a desire to minimize risk and was considered an acceptable alternative under the pressures of several interrelated catastrophic events: the period between 1780 and 1830 was characterized by high climatic variability, several years of droughts, and significantly elevated sea surface temperatures. This was a particularly difficult period of high subsistence risk, and the traditional Chumash buffers of trade and political alliances failed under intense pressures of missionization. Compounding these conditions were European diseases that decimated the Chumash people. Primary sources used for this research include mission documents and registers produced by Franciscan missionaries between 1786 and 1834. Information on paleoenvironmental conditions is derived from high-resolution dendrochronological and marine sedimentary records. 相似文献
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The mitotic spindle is a structure that forms during mitosis to help ensure that each daughter cell receives a full complement of genetic material. In metaphase, the spindle contains microtubules that nucleate inward from two opposing poles. Chromosomes are attached to plus-ends of these microtubules via protein structures called kinetochores. The centromere is the specific region of kinetochore attachment on the chromosome. Chromatin surrounding the centromere (pericentric chromatin) is subject to microtubule-based forces and is commonly modeled as a linear spring, where the force that it exerts is proportional to the distance that it is stretched. We have incorporated physically based models of chromatin to create more accurate and predictive models of the spindle. In addition, using fluorescence microscopy and motion analysis of fluorescently labeled chromatin spots we discovered that pericentric chromatin is restrained relative to free diffusive motion. The characterization of chromatin is crucial to understand mitotic spindle stability and to understand the cell cycle checkpoint regulating anaphase onset. 相似文献
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Andrew N. Tri Joseph P. Sands Michael C. Buelow Damon Williford Erin M. Wehland Jon A. Larson Kyle A. Brazil Jason B. Hardin Fidel Hernández Leonard A. Brennan 《The Journal of wildlife management》2013,77(3):579-586
A landscape-scale assessment of how bobwhite productivity varies in relation to weather does not exist for northern bobwhite (Colinus virginianus). We collected age and sex ratio and body mass data from hunter-harvested bobwhites in 16 counties of South Texas (n = 72,797 bobwhites) during 2001–2009 hunting seasons. We evaluated annual bobwhite production (juvenile:adult age ratios) as a function of cumulative April–August rainfall using National Oceanic and Atmospheric Administration (NOAA) weather station data from Falfurrias and Hebbronville, Texas. We observed minimal among-year change in percent males harvested (51.0–54.5% male) and mean mass (156–160 g) of bobwhites across South Texas. We found no relationship between percent male or body mass and weather. We documented a positive, linear relationship between cumulative April–August rainfall and bobwhite age ratios (r2 = 0.94); we also documented a negative, linear relationship between summer (Jun–Aug) mean maximum daily temperature and bobwhite age ratios (r2 = 0.38). Our results suggest that rainfall is a landscape-scale indicator of annual bobwhite production in South Texas and can thus be used to manage annual expectations of quail hunters prior to the hunting season. © The Wildlife Society, 2012 相似文献
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