18 research outputs found

    AD51B in Familial Breast Cancer

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    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk

    Roll-over shapes of the able-bodied knee-ankle-foot system during gait initiation, steady-state walking, and gait termination

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    A few investigators have described the movement of the center of pressure (COP) of the ground reaction force and the activation patterns of the lower limb muscles during gait initiation and termination. This study examines the effective rocker (roll-over shape) behavior of the knee-ankle-foot (KAF) system during gait initiation, steady-state walking (i.e. constant speed gait), and gait termination. The KAF roll-over shapes were characterized by transforming COP data of 10 able-bodied subjects from a laboratory-based coordinate system into a leg-based coordinate system. The resulting roll-over shapes (effective rockers) were characterized using a circular arc model. The KAF roll-over shapes exhibit an overall ''flexed'' orientation during the first step of gait initiation and an ''extended'' orientation during the last step of gait termination. Understanding the behavior of the anatomical KAF system during gait initiation and termination may aid in the design of prosthetic components, i.e. mechanical devices that replace complete anatomical structures. Prostheses that intend to mimic the overall behavior of physiological KAF systems (biomimetic designs) could be manufactured using approaches that are much simpler than attempting to reconstruct the complexity of the lower limb. Copy Right 2007 Elsevier B.V. All rights reserved. Keywords: Rocker; Roll-over shape; Center of pressure; Prosthetic

    Net external energy of the biologic and prosthetic ankle during gait initiation

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    The net external energy of the biologic human ankle joint and of some lower limb prosthetic ankle-foot systems was examined during gait initiation. The purpose of the study was to better understand the ankle's behavior during the acceleration phase of walking for use in the design of improved lower limb prostheses and orthoses. Quantitative gait data were collected from 10 able-bodied subjects and 10 persons with unilateral transtibial amputations during gait initiation. The behaviors of the biologic and prosthetic 'ankle' joints were examined by analyzing the relationship between sagittal plane ankle angles and moments. Net external energy at the ankle was estimated by calculating the area under the moment versus angle curves (hysteresis) created during the loading and unloading phases. Results indicate that able-bodied persons utilize energy input from the trailing ankle after the first step is made in gait initiation, most likely to help transition the body into steady-state walking. The passive prosthetic ankle-foot systems tested were unable to put energy into the system during gait initiation

    Best After Rain: Waterfall Discharges and the Tourist Experience

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    Waterfalls attract tourists because they are aesthetically appealing landscape features that are not part of everyday experience. It is generally understood that falls are usually seen at their best when there is a copious flow of water, especially after heavy rain. Guidebooks often contain this observation when referring to waterfalls, sometimes warning readers that the flow may be severely reduced during dry periods. Indeed, many visitors are disappointed when they see falls at such times. Some are saddened when the discharge of a waterfall has been depleted by the abstraction of water upstream for power generation or other purposes. While, for those in search of the Sublime or merely the superlative, size is often important, small waterfalls can give great pleasure to lovers of landscape beauty. According to guidebooks, however, even these falls are usually best seen after rain. Drawing on tourist and travel literature and personal journals from the eighteenth century to the present, and with reference to examples from different parts of the world, this paper discusses the importance of discharge in the tourist experience of waterfalls
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