A novel on-chip three-dimensional micromachined calorimeter with fully enclosed and suspended thin-film chamber for thermal characterization of liquid samples

A microfabricated calorimeter (μ-calorimeter) with an enclosed reaction chamber is presented. The 3D micromachined reaction chamber is capable of analyzing liquid samples with volume of 200 nl. The thin film low-stress silicon nitride membrane is used to reduce thermal mass of the calorimeter and increase the sensitivity of system. The μ-calorimeter has been designed to perform DC and AC calorimetry, thermal wave analysis, and differential scanning calorimetry. The μ-calorimeter fabricated with an integrated heater and a temperature sensor on opposite sides of the reaction chamber allows to perform thermal diffusivity and specific heat measurements on liquid samples with same device. Measurement results for diffusivity and heat capacitance using time delay method and thermal wave analysis are presented.     

Fast and reliable droplet transport on single-plate electrowetting on dielectrics using nonfloating switching method

In a droplet transport based on electrowetting on dielectrics, the parallel-plate configuration is more popular than the single-plate one because the droplet transport becomes increasingly difficult without cover plate. In spite of the improved transport performance, the parallel-plate configuration often limits the access to the peripheral components, requesting the removal of the cover plate, the single-plate configuration. We investigated the fundamental features of droplet transport for the single-plate configuration. We compared the performance of several switching methods with respect to maximum speed of successive transport without failure and suggested nonfloating switching method which is inherently free from the charge-residue problem and exerts greater force on a droplet than conventional switching methods. A simple theory is provided to understand the different results for the switching methods.     

Exploiting Hierarchy in Text Categorization

With the recent dramatic increase in electronic access to documents, text categorization—the task of assigning topics to a given document—has moved to the center of the information sciences and knowledge management. This article uses the structure that is present in the semantic space of topics in order to improve performance in text categorization: according to their meaning, topics can be grouped together into meta-topics, e.g., gold, silver, and copper are all metals. The proposed architecture matches the hierarchical structure of the topic space, as opposed to a flat model that ignores the structure. It accommodates both single and multiple topic assignments for each document. Its probabilistic interpretation allows its predictions to be combined in a principled way with information from other sources. The first level of the architecture predicts the probabilities of the meta-topic groups. This allows the individual models for each topic on the second level to focus on finer discriminations within the group. Evaluating the performance of a two-level implementation on the Reuters-22173 testbed of newswire articles shows the most significant improvement for rare classes.     

Science and sports: a brief history of muscle, motion and ad hoc organizations

Both the history of biolocomotion (later to become motion analysis/biomechanics) and of electrology (later kinesiological electromyography) are to be traced back to approximatively the same period in the second half of the seventeenth century. The major contributors to these emergent sciences were Swammerdam in 1658 and Borelli in 1680. Some 150 years later, electrophysiological methods were derived and motion-cinephotography was developed from their pioneering work. Subsequently, use was made of motion analysis by means of cinephotography, forming a basis for biomechanics. The work of Marey in 1873 in particular stimulated the multidisciplinary study of human activity, providing models for contemporary sports scientists working in applied settings. The link between theory and practice in motion sciences and the multidisciplinary model of Marey were the motive and the example for establishing the Working Group of Biomechanics in the 1960s. This body has gone through a series of progressive developments, culminating in the approval of the World Commission of Science and Sports as a service group of the International Council for Sport Science and Physical Education (recognized by UNESCO).     

Open Access and the Transformation of Science——the Time is Ripe

We are experiencing a ＇ climate change＇ in science publishing and we will witness major changes in the way it is being done, resulting in more and more open access to the scientific research literature. The internet makes it all possible, and the impact on science will be phenomenal.     

专业元数据词表研究

因特网已成为全球性的信息环境，我们可以跨越时空获取信息资源。然而，当用户使用自身社区的术语和元数据方案来检索信息时，现在的因特网技术还没有成熟到能提供专业信息设施。元数据担任很重要的角色来帮助实现社区导向的信息环境。本文进行了两项案例研究，包括建立专业主题词表(用于图书馆和图书馆信息科学资源主题网关(LIS)的核心主题词表)和用于地方社区门户网站的主题词表。从这两个案例可以看出小型的主题词表对专业服务是非常有用的，并且维护工作对词表的建立和应用是至关紧要的。为了在网络上建立专业信息环境，我们必须解决对元数据方案来说相悖的两个需求——社区中的专业化(或者本地化)和社区之间的互操作。这篇文章提供了一个概念模型来理解解决这个问题所要涉及的诸多方面。     

The user friendly card catalog

The changing roles and relationships of professional staff in Reference and Cataloging departments in the catalog creation process are discussed. Specific examples are given for handling classification, subject headings and cross references. The article stresses the importance of interface between the two departments in making the catalog more accessible to the users of the library.     

Different visual stimuli affect muscle activation at the knee during sidestepping

Increasing knee stability via appropriate muscle activation could reduce anterior cruciate ligament (ACL) injury risk during unplanned sidestepping. High-level athletes may activate their knee muscles differently from low-level athletes when responding to quasi-game realistic versus non game-realistic stimuli. Eleven high-level and 10 low-level soccer players responded to a non game-realistic arrow-planned condition (AP), a quasi game-realistic one-defender scenario (1DS) and two-defender scenario (2DS), and an arrow-unplanned condition (AUNP), that imposed increasing time constraints to sidestep. Activation from eight knee muscles during sidestepping was measured during pre-contact and weight-acceptance. Knee flexor-extensor co-activation ratios were established. Muscle activation levels increased by approximately 27% solely in the 1DS in both sidestepping phases. In the 2DS, the shift from a flexor dominant co-activation strategy in pre-contact toward extensor dominance in weight-acceptance commenced earlier for the high-level players. Quasi game-realistic information allowed for anticipatory increases in knee muscle activation regardless of expertise levels but only when the time demands to respond were low (1DS). High-level players were better at interpreting complex game-realistic information (2DS) to activate their knee extensors earlier in preparation for single-leg landing during weight-acceptance.     

Perceptual-cognitive expertise when refereeing the scrum in rugby union

Compared to sports performers, relatively little is known about how sports officials make decisions at a perceptual-cognitive level. Thus, this study examined the decision-making accuracy and gaze behaviour of rugby union referees of varying skill levels while reviewing scrum scenarios. Elite (n = 9) and trainee (n = 9) referees, as well as experienced players (n = 9), made decisions while watching ten projected scrum clips and wearing a mobile eye-tracker. Decision-making accuracy and gaze behaviour were recorded for each scrum. The elite and trainee referees made more accurate decisions than the players, and differences in gaze behavior were observed. The elite and trainee referees displayed lower search rates, spent more time fixating central-pack (i.e., front rows, binds, and contact point) and less time fixating outer-pack (e.g., second rows) and non-pack (e.g., other) locations, and exhibited lower entropy than the players. While search rate failed to predict decision-making accuracy, the time spent fixating central-, outer-, and non-pack locations, as well as entropy, were significant predictors. The findings have implications for training perceptual-cognitive skill among sports officials.