2,328 research outputs found

    An ecological study of butter-clam (Saxidomus giganteus) toxicity in southeast Alaska

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    Thesis (M.S.) University of Alaska Fairbanks, 1971Butter clams (Saxidomus giganteus) at South and North porpoise Islands and Pleasant Island, Southeast Alaska, were occasionally found to accumulate significant amounts (higher than the maximum human tolerance) of paralytic shellfish poison (PSP) at any season of the year, and to occasionally lose or regain PSP rapidly between two samplings. The fluctuations of toxicity levels were not similar at all stations and no consistent patterns were Observed. The toxicity of only 19 out of 53 samples collected at three high-toxicity stations exceeded the maximum human tolerance level for PSP (1200 MU), and clam samples taken from moderate and low-toxicity stations never exceeded this level. Neither phytoplankton populations nor hydrographic parameters had a consistently significant correlation with toxicity levels; however, fluctuations of phytoplankton numbers demonstrated an inverse relationship with fluctuations of inorganic nutrient concentrations. Dinoflagellate maxima tended to occur at relatively low salinity (22% - 29%) and relatively high temperatures (7Ā°C - 16Ā°C), whereas the diatom numbers did not significantly correlate with salinity or temperature. The three high-toxicity stations were all within Icy Passage; fluctuations of phytoplankton populations and the hydrographic conditions at these stations were similar, yet the fluctuations of toxicity levels were quite dissimilar. A number of possible sources may be responsible for the butter-clam toxicity in Southeast Alaska. However, more studies are needed to define the cause of the butter-clam poisoning problem in Southeast Alaska

    A Study on Taiwan Consumersā€™ Adoption of Online Financial Services

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    Despite Taiwan financial institutionsā€™ huge investments in online financial services systems, Taiwan consumersā€™ adoption of online financial services has been slower than anticipated. So far, online financial services research in Taiwan is still in its infancy, hence receiving little academic attention. This suggests a need to understand Taiwan Internet usersā€™ adoption behavior of online financial services and to identify the potential factors that may motivate or impede Taiwan Internet usersā€™ acceptance of online financial services. The research framework of this study is constituted by the extended version of the Technology Acceptance Model (TAM2). Other variables, which have proven academically important in influencing consumersā€™ intentions to use information technology, were added to the conceptual framework. The results strongly support that the extended TAM (TAM2) is a valid model to predict Taiwan consumersā€™ intention to use online financial services and to explain the intention difference between adopters and non-adopters. The results also demonstrated that perceived privacy protection, perceived security, and consumer innovativeness not only have a significant, positive relationship with Taiwan consumersā€™ intention to use online financial services but also can significantly predict who is more likely to be an online financial service adopter in Taiwan. The research findings may help Taiwan financial institutions and other interested parties to formulate appropriate marketing strategies and design effective online financial services systems and accelerate the diffusion of online financial services in the future

    Haemophilus Aphrophilus Associated Spleen Abscess: An Unusual Presentation of Subacute Endocarditis

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    The HACEK group of bacteria (Haemophilus spp., Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella spp.), is uncommon pathogens of infective endocarditis, but can cause life-threatening events such as heart failure or formation of lethal emboli. Here we report a 58-year-old Asian man with a past history of congenital valvular heart disease who presented with sudden onset of left flank pain followed by fever with chills for 2 weeks. Abdominal computed tomography (CT) indicated a 1.6 cm abscess in the spleen. Culturing indicated the presence of Haemophilus aphrophilus. We diagnosed the patient with subacute endocarditis complicated with spleen abscess. The patient recovered fully after two weeks antibiotic (Ceftriaxone) treatment. Clinicians should give further attention to infective endocarditis caused by bacteria in the HACEK group in patients with metastatic infection such as spleen abscess with suspected valvular heart disease

    The Development of Audit Detection Risk Assessment System: Using the Fuzzy Theory and Audit Risk Model

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    The result of audit designation is significantly influenced by the audit evidence collected when planning the audit and the degree of detection risk is further depends on the amount of audit evidence. Therefore, when the assessment factors of detection risk are more objective and correct, audit costs and the risk of audit failure can be reduced. Thus, the aim of this paper is to design an audit detection risk assessment system that could more precisely assess detection risk, comparing with the traditional determination method of detection risk in order to increase the audit quality and reduce the possibility of audit failure. First, the grounded theory is used to reorganize 53 factors affecting detection risk mentioned in literatures and then employed the Delphi method to screen the 43 critical risk factors agreed upon by empirical audit experts. In addition, using the fuzzy theory and audit risk model to calculate the degree of detection risk allow the audit staff to further determine the amount of audit evidence collected and set up initial audit strategies and construct the audit detection risk assessment system. Finally, we considered a case study to evaluate the system in terms of its feasibility and validity

    Realtime object extraction and tracking with an active camera using image mosaics

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    [[abstract]]Moving object extraction plays a key role in applications such as object-based videoconference, surveillance, and so on. The dimculties of moving object segmentation lie in the fact that physical objects are normally not homogeneous with to low-level features and it's usually tough to segment them accnrately and efficiently. Object segmentation based on prestored background information has proved to be effective and efficient in several applications such as videophone, video conferencing, and surveillance, etc. The previous works, however, were mainly concentrated on object segmentation with a static camera and in a stationary background. In this paper, we propose a robust and fast segmentation algorithm and a reliable tracking strategy without knowing the shape of the object in advance. The proposed system can real-time extract the foreground from the background and track the moving object with an active (pan-tilt) camera such that the moving object always stays around the center of images.[[fileno]]2030144030033[[department]]é›»ę©Ÿå·„ē؋å­ø

    Extraction of single-trial cortical beta oscillatory activities in EEG signals using empirical mode decomposition

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    <p>Abstract</p> <p>Background</p> <p>Brain oscillatory activities are stochastic and non-linearly dynamic, due to their non-phase-locked nature and inter-trial variability. Non-phase-locked rhythmic signals can vary from trial-to-trial dependent upon variations in a subject's performance and state, which may be linked to fluctuations in expectation, attention, arousal, and task strategy. Therefore, a method that permits the extraction of the oscillatory signal on a single-trial basis is important for the study of subtle brain dynamics, which can be used as probes to study neurophysiology in normal brain and pathophysiology in the diseased.</p> <p>Methods</p> <p>This paper presents an empirical mode decomposition (EMD)-based spatiotemporal approach to extract neural oscillatory activities from multi-channel electroencephalograph (EEG) data. The efficacy of this approach manifests in extracting single-trial post-movement beta activities when performing a right index-finger lifting task. In each single trial, an EEG epoch recorded at the channel of interest (CI) was first separated into a number of intrinsic mode functions (IMFs). Sensorimotor-related oscillatory activities were reconstructed from sensorimotor-related IMFs chosen by a spatial map matching process. Post-movement beta activities were acquired by band-pass filtering the sensorimotor-related oscillatory activities within a trial-specific beta band. Signal envelopes of post-movement beta activities were detected using amplitude modulation (AM) method to obtain post-movement beta event-related synchronization (PM-bERS). The maximum amplitude in the PM-bERS within the post-movement period was subtracted by the mean amplitude of the reference period to find the single-trial beta rebound (BR).</p> <p>Results</p> <p>The results showed single-trial BRs computed by the current method were significantly higher than those obtained from conventional average method (<it>P </it>< 0.01; matched-pair Wilcoxon test). The proposed method provides high signal-to-noise ratio (SNR) through an EMD-based decomposition and reconstruction process, which enables event-related oscillatory activities to be examined on a single-trial basis.</p> <p>Conclusions</p> <p>The EMD-based method is effective for artefact removal and extracting reliable neural features of non-phase-locked oscillatory activities in multi-channel EEG data. The high extraction rate of the proposed method enables the trial-by-trial variability of oscillatory activities can be examined, which provide a possibility for future profound study of subtle brain dynamics.</p

    Thoracic aorta pseudoaneurysm with hemopericardium: unusual presentation of warfarin overdose

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    There have been few case reports which discuss a relationship between warfarin overdose and aortic pseudoaneurysm leakage. We report the case of a female receiving warfarin who presented with dsypnea. Her international normalized ratio was > 10. Chest radiograph revealed cardiomegaly, and chest computed tomography (CT) showed a bulging pouch-like lesion below the aortic arch greater than 6x6 cm in size and a fluid collection suggesting blood in the pericardium. Thoracic endovascular aneurysm repair (TEVAR) was successfully performed by a cardiovascular surgeon. Aortic pseudoaneurysm formation and leakage may be considered as a rare complication in patients receiving warfarin therapy. Further study regarding warfarin use and the incidence of pseudoaneurysm leakage is needed
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