Mood-Congruent Attentional Bias in Dysphoria: Maintained Attention to and Impaired Disengagement From Negative Information.

Attentional bias to negative information has been proposed to be a cognitive vulnerability factor for the development of depression. In 2 experiments, the authors examined mood-congruent attentional bias in dysphoria. In both experiments, dysphoric and nondysphoric participants performed an attentional task with negative, positive, and neutral word cues preceding a target. Targets appeared either at the same or at the opposite location of the cue. Overall, results indicate that dysphoric participants show maintained attention for negative words at longer stimulus presentations, which is probably caused by impaired attentional disengagement from negative words. Furthermore, nondysphoric participants maintain their attention more strongly to positive words. These results are discussed in relation to recent developments in the pathogenesis and treatment of depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simulation of a functional neuromuscular stimulation powered mechanical gait orthosis with coordinated joint locking.

The purpose of this study was to examine a hybrid orthosis system (HOS) for walking after spinal-cord injury (SCI) that coordinates the mechanical locking and unlocking of knee and ankle joints of a reciprocating gait orthosis (RGO), while propulsive forces are injected and unlocked joints controlled with functional neuromuscular stimulation (FNS). The likely effectiveness of the HOS in terms of forward progression, stability, and posture of paraplegic gait was determined in this simulation study. A three-dimensional computer model of a HOS combining FNS with an RGO incorporating feedback control of muscle activation and joint locking was developed. An anthropomorphic human model included passive joint moments and a foot-ground contact model adapted from other studies. A model of the RGO reciprocally coupled the hips and locked and unlocked the knee and ankle joints during stance and swing respectively. The actions of muscles under FNS activation were modeled via closed-loop control of joint torque inputs. A walking aid that mimicked canes and voluntary upper extremity actions maintained lateral stability by providing the necessary shoulder forces and moments. The simulated HOS achieved gait speeds of 0.51 +/- 0.03 m/s, stride lengths of 0.85 +/- 0.04 m, and cadences of 72 +/- 4 steps/min, exceeding the reported performance of other assistive gait systems. Although minimal forward trunk tilt was found to be necessary during specific phases of gait, posture, and stability were significantly improved over FNS-only systems.     

岩体强度参数空间变异性分析

应用地质统计学的理论和方法,以变差函数为工具,对现场实测的岩体强度参数进行了分析,拟合出相应的最优化理论变差函数,并求出了岩体性质参数的相关距离和相关函数,说明了岩体性质的空间变异性特征。     

Delay Bounds for Voice over IP Calls Transported over Satellite Access Networks

Whether or not voice calls of traditional quality can be supported between two users connected to an IP backbone via satellite access systems depends largely on the mouth-to-ear delay, an important part of which is consumed by the satellite networks themselves. In this paper, a methodology is developed to calculate upper bounds for the latter delay component as a function of the used codec, the experienced packet loss ratio, the echo levels at both sides of the connection and the chosen voice packet size. Illustrations are provided.     

Transforming arbitrary tables into logical form with TARTAR

The tremendous success of the World Wide Web is countervailed by efforts needed to search and find relevant information. For tabular structures embedded in HTML documents, typical keyword or link-analysis based search fails. The Semantic Web relies on annotating resources such as documents by means of ontologies and aims to overcome the bottleneck of finding relevant information. Turning the current Web into a Semantic Web requires automatic approaches for annotation since manual approaches will not scale in general. Most efforts have been devoted to automatic generation of ontologies from text, but with quite limited success. However, tabular structures require additional efforts, mainly because understanding of table contents requires the comprehension of the logical structure of the table on the one hand, as well as its semantic interpretation on the other. The focus of this paper is on the automatic transformation and generation of semantic (F-Logic) frames from table-like structures. The presented work consists of a methodology, an accompanying implementation (called TARTAR) and a thorough evaluation. It is based on a grounded cognitive table model which is stepwise instantiated by the methodology. A typical application scenario is the automatic population of ontologies to enable query answering over arbitrary tables (e.g. HTML tables).     

Debugging strategies and tactics in a multi-representation software environment

This paper investigates the interplay between high level debugging strategies and low level tactics in the context of a multi-representation software development environment (SDE). It investigates three questions. 1. How do programmers integrate debugging strategies and tactics when working with SDEs? 2. What is the relationship between verbal ability, level of graphical literacy and debugging (task) performance. 3. How do modality and perspective influence debugging strategy and deployment of tactics? The paper extends the work of Katz and Anderson [1988. Debugging: an analysis of bug location strategies. Human-Computer Interaction 3, 359–399] and others in terms of identifying high level debugging strategies, in this case when working with SDEs. It also describes how programmers of different backgrounds and degrees of experience make differential use of the multiple sources of information typically available in a software debugging environment. Individual difference measures considered among the participants were their programming experience and their knowledge of external representation formalisms. The debugging environment enabled the participants, computer science students, to view the execution of a program in steps and provided them with concurrently displayed, adjacent, multiple and linked programming representations. These representations comprised the program code, two visualisations of the program and its output. The two visualisations of the program were available, in either a largely textual format or a largely graphical format so as to track interactions between experience and low level mode-specific tactics, for example.The results suggest that (i) additionally to deploying debugging strategies similar to those reported in the literature, participants also employed a strategy specific to SDEs, following execution, (ii) verbal ability was not correlated with debugging performance, (iii) knowledge of external representation formalisms was as important as programming experience to succeed in the debugging task, and (iv) participants with greater experience of both programming and external representation formalisms, unlike the less experienced, were able to modify their debugging strategies and tactics effectively when working under different format conditions (i.e. when working with either largely graphical or largely textual visualisations) in order to maintain their high debugging accuracy level.     

Role of apoptosis in gastric epithelial turnover

Gastric epithelial turnover is a dynamic process. It is characterized by continuous cell proliferation, which is counterbalanced by cell loss. The biological principle that mediates the homeostasis of epithelium is programmed cell death, or apoptosis. Currently, several subtypes of apoptosis are distinguished, which are mediated by different mechanisms. Various subtypes of apoptosis also occur in the gastric epithelium under various conditions. In the normal stomach, apoptosis due to cell isolation (anoikis) mediates the physiological epithelial turnover. Albeit rarely seen in routine histology, approximately 2% of epithelial cells in the normal stomach are apoptotic. In Helicobacter pylori-induced gastritis, apoptosis and epithelial proliferation are moderately increased, with approximately 8% apoptotic epithelial cells. In gastritis, factors such as CD95 ligand or tumor necrosis factor (TNF) alpha act as death factors. They bind to specific receptors, CD95 and TNF-R, which are induced either by other cytokines, such as interferon gamma, or by Helicobacter pylori itself. In addition to CD95, H.pylorican also induce upregulation of CD95 ligand expression. Taken together, the upregulated expression of CD95, and the presence of CD95L in the close proximity to apoptotic gastric epithelial cells suggest a functional role of the CD95-CD95L system in the induction of apoptosis in H.pylori-gastritis. The role of other pathways to apoptosis is currently under study. Apart from being a biological phenomenon, apoptosis in the stomach may also have direct clinical consequences. An extreme example is given in gastric graft-vs.-host disease when epithelial denudement occurs.     

Modelling of mercury transport and transformation processes in the Idrijca and Soca river system

In the town of Idrija, Slovenia, the world's second largest mercury mine was active for 500 years and about 37,000 tons of mercury has been lost in the environment. Mercury is still drained from soil, riverbed and floodplains and transported with the Idrijca and Soca Rivers to the Gulf of Trieste. A part of inorganic mercury is methylated either in the river system, or later in the coastal area, and, due to its bioaccumulation and biomagnification represents potential danger to human health. A 1-D aquatic model MeRiMod was used to simulate hydrodynamics and sediment transport in the river system from Idrija to the Soca River mouth. Transport of particle bound and dissolved mercury as well as potential net methylation of mercury in the river system was simulated. The simulation of an observed flood wave with 20-year recurrence period was performed in order to validate the model. Methylation was simulated at lower discharges, as higher methylation rates occur in such conditions. The measurement data and the MeRiMod model were also used to establish a historical mercury mass balance of the Idrijca and Soca Rivers catchment. Sediment core data from the Gulf of Trieste and the measured concentrations from floodplains were used to verify and calibrate the model. Simulations of different high discharges were performed as most of the transport of particulate mercury occurs within flood wave conditions. Compared to the measurements, the results of the model showed an agreement within an order of magnitude, for the transport of total mercury mostly within a factor of 4, and for the methylation within a factor of 5. However, proper trends of the phenomena were obtained by simulations. The combination of modelling and measurements has resulted in some interesting conclusions about the phenomenon of the transport and transformations of mercury in the observed river system.     

An energy-efficient air-conditioning system for hydrogen driven cars

In this paper a new operation principle of an air-conditioning system for hydrogen driven cars is proposed and experimental results of a laboratory prototype are presented. The system is able to utilize the potential energy of the compressed hydrogen gas as main driving energy to generate a cooling effect usable for e.g. air-conditioning. Therefore, it is able to partially reuse the compression energy originally spent in order to increase the energy density of hydrogen but is so far wasted onboard. The underlying principle of the process is based on a chemical reaction of a metal hydride (Ti_0.99Zr_0.01V_0.43Fe_0.09Cr_0.05Mn_1.5) with hydrogen at different pressures and corresponding equilibrium temperatures. The laboratory prototype consists of two alternating capillary tube bundle reactors (together around 5 kg and 1.5 l) and is able to generate a quasi-continuous cooling effect at 13 °C in the order of 900 W.