面向大规模胸片图像的深度哈希检索

目的 医学图像检索在疾病诊断、医疗教学和辅助症状参考中发挥了重要作用,但由于医学图像类间相似度高、病灶易遗漏以及数据量较大等问题,使得现有哈希方法对病灶区域特征的关注较少,图像检索准确率较低。对此,本文以胸部X-ray图像为例,提出一种面向大规模胸片图像的深度哈希检索网络。方法 在特征学习部分,首先采用ResNet-50作为主干网络对输入图像进行特征提取得到初步特征,将该特征进行细化后获得全局特征;同时将初步特征输入构建的空间注意模块,该注意模块结合了3个描述符用于聚焦胸片图像中的显著区域,将该模块的输出进行细化得到局部特征;最后融合全局特征与局部特征用于后续哈希码优化。在哈希码优化部分,使用定义的二值交叉熵损失、对比损失和正则化损失的联合函数进行优化学习,生成高质量的哈希码用于图像检索。结果 为了验证方法的有效性,在公开的ChestX-ray8和CheXpert数据集上进行对比实验。结果显示,构建空间注意模块有助于关注病灶区域,定义特征融合模块有效避免了信息的遗漏,联合3个损失函数进行优化可以获得高质量哈希码。与当前先进的医学图像检索方法比较,本文方法能够有效提高医学图像检索的准确率...     

Vibrotactile and vibroacoustic communications: pairs in interaction and play—an interactive structure and bodies in an urban environment

We designed a vibrotactile vest and The Humming Wall, a vibroacoustic interactive furniture set in an urban environment to interact with each other. We developed the vibrotactile patterns in the vest as a form of vibrotactile language to convey information to the wearer. In addition, we designed a set of interactive movements on The Humming Wall that would trigger patterns on the vest and elicit sensations and encourage body movements onto the wearer’s body. We invited people to interact in pairs at The Humming Wall, with one at the wall and one wearing the vest (they later swapped roles). Actions by the one at the wall, such as swiping or knocking on the wall were repeated on the vest wearer’s body. In addition, participants could ‘feel’ (vibroacoustically) and hear their own heartbeats and breath rates at the wall. We conducted a field trial with 39 participants over a 5-week period. Participants wearing the vest (and their pair) completed a set of tasks. We logged use and responses, recorded all activities on video and conducted post-experiment interviews and questionnaires. The results depicted the participants’ experience, communication and connection while wearing the vibrotactile vest and interacting with the wall. The findings show convincing, strong and positive responses to novel interactions between the responsive vibroacoustic environment and the vibrotactile vest. This work constitutes the first field trial with people ‘working’ in pairs with a vibrotactile wearable responding to and driving vibroacoustic displays with an interactive vibroacoustic environment.     

Involvement in traditional and electronic bullying among adolescents.

The increasing availability of Internet and cell phones has provided new avenues through which adolescents can bully. Electronic bullying is a new form of bullying that may threaten adolescent social and emotional development. In this study the relation between involvement in electronic and traditional bullying was examined. Eighty-four adolescents completed questionnaires regarding their involvement in traditional and electronic bullying. Results show that students' roles in traditional bullying predicted the same role in electronic bullying. Also, being a victim of bullying on the Internet or via text messages was related to being a bully at school. Traditional victims were not found to be electronic bullies. Perceptions of the effects of and motivations for electronic bullying are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for metabolic activity of airborne bacteria

Aerosols of the bacterium Serratia marcescens and of uniformly labelled ¹⁴C glucose were produced simultaneously by two separate atomizers and mixed within tubing leading to an aerosol chamber where the r.h. was 90–95%. About 15% coagulation occurred. During a subsequent period of about 5 hr, ¹⁴CO₂ was produced metabolically within the chamber and labelled material incorporated within the suspended particles first increased and then decreased. This constitutes the first direct evidence of microbial metabolism of bacteria suspended in the air.     

Lipoprotein synthesis. I. rat plasma lipoprotein composition and synthesis from radioactive precursors

The in vivo synthesis of rat plasma lipoproteins was studied by the use of isotopic protein and lipid precursors. Labelled amino acids, palmitic acid and tripalmitin were administered by stomach tube and the radioactivity in the plasma lipoproteins was determined following preparative ultracentrifugal isolation at densities of 1.006, 1.019, 1.063 and 1.21 g/ml. In response to triglyceride feeding, amino acid composition of the high density lipoprotein changed little, but in the low density lipoproteins proportionality in the amino acid pattern was changed as reflected by increases and decreases in certain amino acids. Isotopic amino acids were not incorporated in proportion to the relative abundance with which they occurred in the lipoproteins. Triglyceride feeding markedly stimulated isotope utilization, especially in the low density fractions. Methionine, though only present in small amounts, was extensively utilized and it is suggested that this amino acid may play a significant role in the synthesis of lipoproteins, other than the role of a methyl donor for phosphatidylcholine.