SVM for density estimation and application to medical image segmentation

A method of medical image segmentation based on support vector machine （SVM） for density estimation is presented. We used this estimator to construct a prior model of the image intensity and curvature profile of the structure from training images. When segmenting a novel image similar to the training images, the technique of narrow level set method is used. The higher dimensional surface evolution metric is defined by the prior model instead of by energy minimization function. This method offers several advantages. First, SVM for density estimation is consistent and its solution is sparse. Second, compared to the traditional level set methods, this method incorporates shape information on the object to be segmented into the segmentation process. Segmentation results are demonstrated on synthetic images, MR images and ultrasonic images.     

Proximity-to-goal as a constraint on patterns of behaviour in attacker-defender dyads in team games

The aim of this study was to determine whether spatiotemporal interactions between footballers and the ball in 1 vs. 1 sub-phases are influenced by their proximity to the goal area. Twelve participants (age 15.3 ± 0.5 years) performed as attackers and defenders in 1 vs. 1 dyads across three field positions: (a) attacking the goal, (b) in midfield, and (c) advancing away from the goal area. In each position, the dribbler was required to move beyond an immediate defender with the ball towards the opposition goal. Interactions of attacker-defender dyads were filmed with player and ball displacement trajectories digitized using manual tracking software. One-way repeated measures analysis of variance was used to examine differences in mean defender-to-ball distance after this value had stabilized. Maximum attacker-to-ball distance was also compared as a function of proximity-to-goal. Significant differences were observed for defender-to-ball distance between locations (a) and (c) at the moment when the defender-to-ball distance had stabilized (a: 1.69 ± 0.64 m; c: 1.15 ± 0.59 m; P < 0.05). Findings indicate that proximity-to-goal influenced the performance of players, particularly when attacking or advancing away from goal areas, providing implications for training design in football. In this study, the task constraints of football revealed subtly different player interactions than observed in previous studies of dyadic systems in basketball and rugby union.     

从生物小问题中引发学生的生物兴趣

如何激发学生学习生物的兴趣,不同的学者有不同的看法和做法。其实,生物学本身就含有许多吸引学生的内在因素,我们可以很好地加以利用。特别是生物学中那些细小而具体的问题,更贴近学生的日常生活,尤其容易引发学生的好奇心,从而产生生物兴趣。     

Draw a Leaf for Life

阅读提示一个小女孩即将走到人生的尽头,伤心欲绝的妈妈找到了她的画家朋友。这位艺术家为小女孩画了一些树叶。没想到这些树叶竟奇迹般地使这个身患重病的小女孩在绝望中看到了希望。想了解这个故事吗?赶快来读一读吧!     

Patterns and costs of printed and online journal usage

This study in an academic medical sciences library setting examines the correlation of usage of a matched set of print and online titles, the validity of e-journals usage statistics and the impact of online journals on print journal usage. The print and online usage was determined for 270 journals, both versions of which were available. Print usage was determined annually since 1997 using the reshelving and the error-copies method. Online usage statistics were delivered by five publishers and corrected for redundant multiple accesses. Print journal usage decreased by 22.3 and 30.2% respectively over each of 2 years after the introduction of online journals. Journals published both in print and online lost 30.4% of their print usage within 2 years. The total loss of usage of print-only titles in the same period was somewhat higher, at 45.8%. The average correlation between online and print usage is 0.60 and 0.67 respectively. For the examined titles, users accessed the online versions ten times as often as the print version. Two clearly distinguishable groupings emerged: while with Academic Press and Elsevier, e-journal usage exceeded print usage by a factor of 3 or 4, the e-journals of Blackwell, HighWire and Springer were used on average 14.6 times as frequently as the corresponding print journals. Each usage of a print article cost 2.79-50.82 Euro, each usage of an online article 0.31-15.10 Euro, depending on the publisher. On average, the usage of an online article was 5.4 times cheaper. Within 2-3 years the usage of online journals has outstripped that of print titles by a factor of ten, but the specific spectrum of usage remains much the same as when only print journals alone existed. Print titles not available online suffer a greater decline in usage compared with print/online journals. This confirms that what is read or purchased is determined primarily by ease of access and that there is a steady tendency to reduce the multiplicity of access modes to a manageable few. The availability of journals online seems to have created a new clientele, at least in the case of the German-language Springer journals. The connection between supplier and supply is much less clear with e-journals than it is with print titles. Therefore it is very important to stress and encourage the role of the library as the supplier of this sort of information in the university environment. Collection building issues are discussed in the light of the results.     

祝贺与期望——我省三家报纸举办报庆活动

本刊讯 12月7日,新中国成立后全国创办最早的省级工人报《浙江工人日报》举行创刊55周年座谈会。 《浙江工人日报》于1949年12月7日创刊,在长期的办报实践中逐渐形成了自己鲜明的办报特色。特别是随着浙江社会、经济渐显多元化,《断江工人日报》深入地剖析社会热点难点问题,积极探索维护职工合法权益的新途径,多次与有关部门联手,坚定地维护职工的合法权益。