911 resultados para Geometric mean titer
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RATIONALE In biomedical journals authors sometimes use the standard error of the mean (SEM) for data description, which has been called inappropriate or incorrect. OBJECTIVE To assess the frequency of incorrect use of SEM in articles in three selected cardiovascular journals. METHODS AND RESULTS All original journal articles published in 2012 in Cardiovascular Research, Circulation: Heart Failure and Circulation Research were assessed by two assessors for inappropriate use of SEM when providing descriptive information of empirical data. We also assessed whether the authors state in the methods section that the SEM will be used for data description. Of 441 articles included in this survey, 64% (282 articles) contained at least one instance of incorrect use of the SEM, with two journals having a prevalence above 70% and "Circulation: Heart Failure" having the lowest value (27%). In 81% of articles with incorrect use of SEM, the authors had explicitly stated that they use the SEM for data description and in 89% SEM bars were also used instead of 95% confidence intervals. Basic science studies had a 7.4-fold higher level of inappropriate SEM use (74%) than clinical studies (10%). LIMITATIONS The selection of the three cardiovascular journals was based on a subjective initial impression of observing inappropriate SEM use. The observed results are not representative for all cardiovascular journals. CONCLUSION In three selected cardiovascular journals we found a high level of inappropriate SEM use and explicit methods statements to use it for data description, especially in basic science studies. To improve on this situation, these and other journals should provide clear instructions to authors on how to report descriptive information of empirical data.
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Two groundwater bodies, Grazer Feld and Leibnitzer Feld, with surface areas of 166 and 103 km2 respectively are characterised for the first time by measuring the combination of d18O/d2H, 3H/3He, 85Kr, CFC-11, CFC-12 and hydrochemistry in 34 monitoring wells in 2009/2010. The timescales of groundwater recharge have been characterised by 131 d18O measurements of well and surface water sampled on a seasonal basis. Most monitoring wells show a seasonal variation or indicate variable contributions of the main river Mur (0–30%, max. 70%) and/or other rivers having their recharge areas in higher altitudes. Combined d18O/d2H-measurements indicate that 65–75% of groundwater recharge in the unusual wet year of 2009 was from precipitation in the summer based on values from the Graz meteorological station. Monitoring wells downstream of gravel pit lakes show a clear evaporation trend. A boron–nitrate differentiation plot shows more frequent boron-rich water in the more urbanised Grazer Feld and more frequent nitrate-rich water in the more agricultural used Leibnitzer Feld indicating that a some of the nitrate load in the Grazer Feld comes from urban sewer water. Several lumped parameter models based on tritium input data from Graz and monthly data from the river Mur (Spielfeld) since 1977 yield a Mean Residence Time (MRT) for the Mur-water itself between 3 and 4 years in this area. Data from d18O, 3H/3He measurements at the Wagna lysimeter station supports the conclusion that 90% of the groundwaters in the Grazer Feld and 73% in the Leibnitzer Feld have MRTs of <5 years. Only in a few groundwaters were MRTs of 6–10 or 11–25 years as a result of either a long-distance water inflow in the basins or due to longer flow path in somewhat deeper wells (>20 m) with relative thicker unsaturated zones. The young MRT of groundwater from two monitoring wells in the Leibnitzer Feld was confirmed by 85Kr-measurements. Most CFC-11 and CFC-12 concentrations in the groundwater exceed the equilibration concentrations of modern concentrations in water and are therefore unsuitable for dating purposes. An enrichment factor up to 100 compared to atmospheric equilibrium concentrations and the obvious correlation of CFC-12 with SO4, Na, Cl and B in the ground waters of the Grazer Feld suggest that waste water in contact with CFC-containing material above and below ground is the source for the contamination. The dominance of very young groundwater (<5 years) indicates a recent origin of the contamination by nitrate and many other components observed in parts of the groundwater bodies. Rapid measures to reduce those sources are needed to mitigate against further deterioration of these waters.
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Introduction: Organisational changes in sports federations are often associated with a drift from a volunteer driven to an increasingly business-like phenomenon (Shilbury & Ferkins, 2011). This process of transfor-mation is be called as “professionalization”. Accordingly, professionalization seems to be an appropriate strategy for sport organisations in order to meet organizational pressure due to challenges of a more complex and dynamic changing environment adequately. Despite the increasing research interest and the attempts for systematization on the phenomenon of professionalization it still remains unclear what does the term professionalization exactly mean (Dowling et al., 2014). Thus, there is a lack of a consistent concept of professionalization that is needed in order to explore different facets and perspectives of this phenomenon more validly. Against this background following question emerged: What is the suitable concept of professionalization for analyzing the actual ongoing processes of change, adaption or transformation in sport federations? Methods: Dealing with this question, following two-step approach was choosen: (1) In a first step a scholar’s perspective at professionalisation of sport organisations will be displayed in order to explore both the common ground as well as divergences and inconsistencies in previous approaches. Therefore, a literature review is indicated. (2) In a second step, and in contrast to previous studies we will consider a practical point of view by a so called second-order observation of experts to gain valuable insights into current thinking and acting towards professionalization in sport federations. In doing so, a hermeneutical approach is used, which is about understanding the meaning of contexts by grasping the everyday world, and draw insight and meaning from it (Shilbury et al., 2013). Accordance with hermeneutics, the explorative interpretive knowledge of expert interviews was used. The interviews were conducted with a sample of six selected experts, who have both dedicated insider knowledge and the overall view of all Swiss sport federations. Results and discussion: The summaries of literature review could be categorized into two research currents. The one defines professionalization as a structural process towards professional status of occupations. The other defines it in a broader sense as an organisational change towards a business-like approach. Whereas the first perspective there is a broad scientific consensus that second isn’t that clear, however. Explorative analysis of interview data reveals different themes in relation to professionalization of sports federation. First theme deals with a changed philosophy as more strategic alignment towards for-profit, efficiency and quality orientation. Second theme refers to paid work associated with more competence orientation and balanced governance between paid and voluntary work. Third theme deals with acting shift towards more rationalization and efficiency by implementation of innovative management and communication tools. Based on findings of both our review of scholar`s perspective as well insights from experts we will provide – in the sense of synthesis – a more clear understanding of what does professionalization mean that can be useful in terms of further studies. References: Dowling, M., Edwards, J. & Washington, M. (2014). Understanding the concept of professionalisation in sport management research. Sport Management Review, 17 (4), 520–529. Shilbury, D., Ferkins, L. & Smythe, L. (2013). Sport governance encounters: Insights from lived experiences. Sport Management Review, 16,349–363. Shilbury, D., & Ferkins, L. (2011). Professionalisation, sport governance and strategic capability. Managing Leisure, 16, 108–127.
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In this paper we propose a new fully-automatic method for localizing and segmenting 3D intervertebral discs from MR images, where the two problems are solved in a unified data-driven regression and classification framework. We estimate the output (image displacements for localization, or fg/bg labels for segmentation) of image points by exploiting both training data and geometric constraints simultaneously. The problem is formulated in a unified objective function which is then solved globally and efficiently. We validate our method on MR images of 25 patients. Taking manually labeled data as the ground truth, our method achieves a mean localization error of 1.3 mm, a mean Dice metric of 87%, and a mean surface distance of 1.3 mm. Our method can be applied to other localization and segmentation tasks.
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This paper addresses the problem of fully-automatic localization and segmentation of 3D intervertebral discs (IVDs) from MR images. Our method contains two steps, where we first localize the center of each IVD, and then segment IVDs by classifying image pixels around each disc center as foreground (disc) or background. The disc localization is done by estimating the image displacements from a set of randomly sampled 3D image patches to the disc center. The image displacements are estimated by jointly optimizing the training and test displacement values in a data-driven way, where we take into consideration both the training data and the geometric constraint on the test image. After the disc centers are localized, we segment the discs by classifying image pixels around disc centers as background or foreground. The classification is done in a similar data-driven approach as we used for localization, but in this segmentation case we are aiming to estimate the foreground/background probability of each pixel instead of the image displacements. In addition, an extra neighborhood smooth constraint is introduced to enforce the local smoothness of the label field. Our method is validated on 3D T2-weighted turbo spin echo MR images of 35 patients from two different studies. Experiments show that compared to state of the art, our method achieves better or comparable results. Specifically, we achieve for localization a mean error of 1.6-2.0 mm, and for segmentation a mean Dice metric of 85%-88% and a mean surface distance of 1.3-1.4 mm.
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Professionalization seems to be an appropriate strategy for sports organizations to meet organizational pressure due to challenges of a more complex and dynamic changing environment (e.g. Shilbury & Ferkins, 2011). However, despite the increasing number of studies attempting to disclose professionalization in sports organizations, it still remains unclear, what the term professionalization actually mean, and which aspects a suitable concept of professionalization for studying the phenomena should consist in (Dowling et al., 2014). To bridge this gap, we firstly display scholars’ perspective of professionalization in sports organizations in order to explore the common ground as well as divergences in previous approaches. We will then consider practical views of Swiss experts to gain valuable insight, as pointed out by Slack (2014), into current thinking and acting towards professionalization in sports federations in Switzerland. In semi-structured interviews, we asked six experts, who accompany the professionalization processes of Swiss national sports federations, about their subjective understanding of professionalization, and its characteristics. The interviews were analyzed applying hermeneutic approach to systematically reconstruct the observed characteristics of professionalization resulting in three main topics: (1) changed management philosophy, (2) specialization and functional differentiation, and (3) management tools. Based on the literature review as well as insights from the Swiss experts, we will provide a synthesis of crucial aspects for developing a conceptual framework of professionalization that can be useful for further studies. References Dowling, M., Edwards, J., & Washington, M. (2014). Understanding the concept of professionalisation in sport management research. Sport Management Review, 17, 520-529. Shilbury, D., & Ferkins, L. (2011). Professionalisation, sport governance and strategic capability. Managing Leisure, 16, 108-127. Slack, T. (2014). The social and commercial impact of sport, the role of sport management. European Sport Management Quarterly, 14, 454–463.
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We describe the recovery of three daily meteorological records for the southern Alps (Domodossola, Riva del Garda, and Rovereto), all starting in the second half of the nineteenth century. We use these new data, along with additional records, to study regional changes in the mean temperature and extreme indices of heat waves and cold spells frequency and duration over the period 1874–2015. The records are homogenized using subdaily cloud cover observations as a constraint for the statistical model, an approach that has never been applied before in the literature. A case study based on a record of parallel observations between a traditional meteorological window and a modern screen shows that the use of cloud cover can reduce the root-mean-square error of the homogenization by up to 30% in comparison to an unaided statistical correction. We find that mean temperature in the southern Alps has increased by 1.4°C per century over the analyzed period, with larger increases in daily minimum temperatures than maximum temperatures. The number of hot days in summer has more than tripled, and a similar increase is observed in duration of heat waves. Cold days in winter have dropped at a similar rate. These trends are mainly caused by climate change over the last few decades.
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PURPOSE In the present case series, the authors report on seven cases of erosively worn dentitions (98 posterior teeth) which were treated with direct resin composite. MATERIALS AND METHODS In all cases, both arches were restored by using the so-called stamp technique. All patients were treated with standardized materials and protocols. Prior to treatment, a waxup was made on die-cast models to build up the loss of occlusion as well as ensure the optimal future anatomy and function of the eroded teeth to be restored. During treatment, teeth were restored by using templates of silicone (ie, two "stamps," one on the vestibular, one on the oral aspect of each tooth), which were filled with resin composite in order to transfer the planned, future restoration (ie, in the shape of the waxup) from the extra- to the intraoral situation. Baseline examinations were performed in all patients after treatment, and photographs as well as radiographs were taken. To evaluate the outcome, the modified United States Public Health Service criteria (USPHS) were used. RESULTS The patients were re-assessed after a mean observation time of 40 months (40.8 ± 7.2 months). The overall outcome of the restorations was good, and almost exclusively "Alpha" scores were given. Only the marginal integrity and the anatomical form received a "Charlie" score (10.2%) in two cases. CONCLUSION Direct resin composite restorations made with the stamp technique are a valuable treatment option for restoring erosively worn dentitions.
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PURPOSE The study aims to evaluate three-dimensionally (3D) the accuracy of implant impressions using a new resin splinting material, "Smart Dentin Replacement" (SDR). MATERIALS AND METHODS A titanium model of an edentulous mandible with six implant analogues was used as a master model and its dimensions measured with a coordinate measuring machine. Before the total 60 impressions were taken (open tray, screw-retained abutments, vinyl polysiloxane), they were divided in four groups: A (test): copings pick-up splinted with dental floss and fotopolymerizing SDR; B (test): see A, additionally sectioned and splinted again with SDR; C (control): copings pick-up splinted with dental floss and autopolymerizing Duralay® (Reliance Dental Mfg. Co., Alsip, IL, USA) acrylic resin; and D (control): see C, additionally sectioned and splinted again with Duralay. The impressions were measured directly with an optomechanical coordinate measuring machine and analyzed with a computer-aided design (CAD) geometric modeling software. The Wilcoxon matched-pair signed-rank test was used to compare groups. RESULTS While there was no difference (p = .430) between the mean 3D deviations of the test groups A (17.5 μm) and B (17.4 μm), they both showed statistically significant differences (p < .003) compared with both control groups (C 25.0 μm, D 19.1 μm). CONCLUSIONS Conventional impression techniques for edentulous jaws with multiple implants are highly accurate using the new fotopolymerizing splinting material SDR. Sectioning and rejoining of the SDR splinting had no impact on the impression accuracy.