4,346 research outputs found

    Large earthquakes create vertical permeability by breaching aquitards

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    Hydrologic responses to earthquakes and their mechanisms have been widely studied. Some responses have been attributed to increases in the vertical permeability. However, basic questions remain: How do increases in the vertical permeability occur? How frequently do they occur? Is there a quantitative measure for detecting the occurrence of aquitard breaching? We try to answer these questions by examining data from a dense network of ∼50 monitoring stations of clustered wells in a sedimentary basin near the epicenter of the 1999 M7.6 Chi-Chi earthquake in western Taiwan. While most stations show evidence that confined aquifers remained confined after the earthquake, about 10% of the stations show evidence of coseismic breaching of aquitards, creating vertical permeability as high as that of aquifers. The water levels in wells without evidence of coseismic breaching of aquitards show tidal responses similar to that of a confined aquifer before and after the earthquake. Those wells with evidence of coseismic breaching of aquitards, on the other hand, show distinctly different postseismic tidal response. Furthermore, the postseismic tidal response of different aquifers became strikingly similar, suggesting that the aquifers became hydraulically connected and the connection was maintained many months thereafter. Breaching of aquitards by large earthquakes has significant implications for a number of societal issues such as the safety of water resources, the security of underground waste repositories, and the production of oil and gas. The method demonstrated here may be used for detecting the occurrence of aquitard breaching by large earthquakes in other seismically active areas

    Developing an interactive game platform to promote learning and teamwork on mobile devices: an experience report

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    In the past few Years, many new development toolkits such as the Nebula2 and/or mobile technologies including the WiFi or mobileTV have opened up exciting learning opportunities on mobile devices. On top of it, new technologies continue to fuel the rapid growth of newly merged fields of research like the edutainment for educational entertainment. In a recent teaching development project, we have developed an interactive game platform to facilitate learning and more importantly the spirit of teamwork for collaborative problem-solving on desktop and pocket PCs. With the great challenges imposed by globalization, we strongly believe that learning to collaboratively analyze and then apply the "appropriate" knowledge to solve a specific problem is always the key to success. In this paper, we discuss about an on-going work, and share our relevant experience in system development. Furthermore, evaluation strategies will be thoroughly examined. After all, our work shed light on many interesting directions for future exploration. © 2008 IEEE.published_or_final_versio

    Atorvastatin correlates with decreased risk of esophageal cancer: A population-based casecontrol study from Taiwan

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    Objectives: The aim of this study was to explore the association between the use of statins and esophageal cancer in Taiwan.Methods: We designed a casecontrol study using database from the Taiwan National Health Insurance program. In all, 549 patients (cases) aged 20 years or older diagnosed recently with esophageal cancer, from 2000 to 2009, and 2,196 subjects (controls) without esophageal cancer participated in this study. The association between esophageal cancer and the use of statins and other co-morbidities was measured.Results: After adjustment for covariates, multivariate logistic regression showed that patients with a cumulative duration of ]12 months of using atorvastatin might have a reduced risk of esophageal cancer, compared with those who did not use statins (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.040.56). The other statins could not show a significant association with esophageal cancer. Age (OR 1.01, 95% CI 1.001.01), alcoholism (OR 3.83, 95% CI 3.014.89), and esophageal diseases (OR 4.60, 95% CI 3.466.12) were independent factors significantly associated with esophageal cancer.Conclusions: Use of atorvastatin ]12 months may correlate with an 86% reduction of esophageal cancer risk.Keywords: atorvastatin; esophageal cancer; stati

    Atorvastatin correlates with decreased risk of esophageal cancer: A population-based casecontrol study from Taiwan

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    Objectives: The aim of this study was to explore the association between the use of statins and esophageal cancer in Taiwan.Methods: We designed a casecontrol study using database from the Taiwan National Health Insurance program. In all, 549 patients (cases) aged 20 years or older diagnosed recently with esophageal cancer, from 2000 to 2009, and 2,196 subjects (controls) without esophageal cancer participated in this study. The association between esophageal cancer and the use of statins and other co-morbidities was measured.Results: After adjustment for covariates, multivariate logistic regression showed that patients with a cumulative duration of ]12 months of using atorvastatin might have a reduced risk of esophageal cancer, compared with those who did not use statins (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.040.56). The other statins could not show a significant association with esophageal cancer. Age (OR 1.01, 95% CI 1.001.01), alcoholism (OR 3.83, 95% CI 3.014.89), and esophageal diseases (OR 4.60, 95% CI 3.466.12) were independent factors significantly associated with esophageal cancer.Conclusions: Use of atorvastatin ]12 months may correlate with an 86% reduction of esophageal cancer risk.Keywords: atorvastatin; esophageal cancer; stati

    Discovering sequential rental patterns by fleet tracking

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    © Springer International Publishing Switzerland 2015. As one of the most well-known methods on customer analysis, sequential pattern mining generally focuses on customer business transactions to discover their behaviors. However in the real-world rental industry, behaviors are usually linked to other factors in terms of actual equipment circumstance. Fleet tracking factors, such as location and usage, have been widely considered as important features to improve work performance and predict customer preferences. In this paper, we propose an innovative sequential pattern mining method to discover rental patterns by combining business transactions with the fleet tracking factors. A novel sequential pattern mining framework is designed to detect the effective items by utilizing both business transactions and fleet tracking information. Experimental results on real datasets testify the effectiveness of our approach

    The Clinical Application of Anti-CCP in Rheumatoid Arthritis and Other Rheumatic Diseases

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    Rheumatoid arthritis (RA) is a common rheumatic disease in Caucasians and in other ethnic groups. Diagnosis is mainly based on clinical features. Before 1998, the only serological laboratory test that could contribute to the diagnosis was that for rheumatoid factor (RF). The disease activity markers for the evaluation of clinical symptoms or treatment outcome were the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). As a matter of fact, the diagnosis of early RA is quite impossible, as the clinical criteria are insufficient at the beginning stage of the disease. In 1998, Schelleken reported that a high percentage of RA patients had a specific antibody that could interact with a synthetic peptide which contained the amino acid citrulline. The high specificity (98%) for RA of this new serological marker, anti-cyclic citrullinated antibody (anti-CCP antibody), can be detected early in RA, before the typical clinical features appear. The presence or absence of this antibody can easily distinguish other rheumatic diseases from RA. Additionally, the titer of anti-CCP can be used to predict the prognosis and treatment outcome after DMARDs or biological therapy. Therefore, with improvement of sensitivity, the anti-CCP antibody will be widely used as a routine laboratory test in the clinical practice for RA

    Exploring the Brain Responses to Driving Fatigue through Simultaneous EEG and fNIRS Measurements

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    © 2020 World Scientific Publishing Company. Fatigue is one problem with driving as it can lead to difficulties with sustaining attention, behavioral lapses, and a tendency to ignore vital information or operations. In this research, we explore multimodal physiological phenomena in response to driving fatigue through simultaneous functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) recordings with the aim of investigating the relationships between hemodynamic and electrical features and driving performance. Sixteen subjects participated in an event-related lane-deviation driving task while measuring their brain dynamics through fNIRS and EEGs. Three performance groups, classified as Optimal, Suboptimal, and Poor, were defined for comparison. From our analysis, we find that tonic variations occur before a deviation, and phasic variations occur afterward. The tonic results show an increased concentration of oxygenated hemoglobin (HbO2) and power changes in the EEG theta, alpha, and beta bands. Both dynamics are significantly correlated with deteriorated driving performance. The phasic EEG results demonstrate event-related desynchronization associated with the onset of steering vehicle in all power bands. The concentration of phasic HbO2 decreased as performance worsened. Further, the negative correlations between tonic EEG delta and alpha power and HbO2 oscillations suggest that activations in HbO2 are related to mental fatigue. In summary, combined hemodynamic and electrodynamic activities can provide complete knowledge of the brain's responses as evidence of state changes during fatigue driving

    A novel 16-channel wireless system for electroencephalography measurements with dry spring-loaded sensors

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    Understanding brain function using electroencephalography (EEG) is an important issue for cerebral nervous system diseases, especially for epilepsy and Alzheimer's disease. Many EEG measurement systems are used reliably to study these diseases, but their bulky size and the use of wet sensors make them uncomfortable and inconvenient for users. To overcome the limitations of conventional EEG measurement systems, a wireless and wearable multichannel EEG measurement system is proposed in this paper. This system includes a wireless data acquisition device, dry spring-loaded sensors, and a sizeadjustable soft cap. We compared the performance of the proposed system using dry versus conventional wet sensors. A significant positive correlation between readings from wet and dry sensors was achieved, thus demonstrating the performance of the system. Moreover, four different features of EEG signals (i.e., normal, eye-blinking, closed-eyes, and teeth-clenching signals) were measured by 16 dry sensors to ensure that they could be detected in real-life cognitive neuroscience applications. Thus, we have shown that it is possible to reliably measure EEG signals using the proposed system. This paper presents novel insights into the field of cognitive neuroscience, showing the possibility of studying brain function under real-life conditions. © 2014 IEEE
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