1,246 research outputs found

    InfoFlowNet: A Multi-head Attention-based Self-supervised Learning Model with Surrogate Approach for Uncovering Brain Effective Connectivity

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    Deciphering brain network topology can enhance the depth of neuroscientific knowledge and facilitate the development of neural engineering methods. Effective connectivity, a measure of brain network dynamics, is particularly useful for investigating the directional influences among different brain regions. In this study, we introduce a novel brain causal inference model named InfoFlowNet, which leverages the self-attention mechanism to capture associations among electroencephalogram (EEG) time series. The proposed method estimates the magnitude of directional information flow (dIF) among EEG processes by measuring the loss of model inference resulting from the shuffling of the time order of the original time series. To evaluate the feasibility of InfoFlowNet, we conducted experiments using a synthetic time series and two EEG datasets. The results demonstrate that InfoFlowNet can extract time-varying causal relationships among processes, reflected in the fluctuation of dIF values. Compared with the Granger causality model and temporal causal discovery framework, InfoFlowNet can identify more significant causal edges underlying EEG processes while maintaining an acceptable computation time. Our work demonstrates the potential of InfoFlowNet for analyzing effective connectivity in EEG data. The findings highlight the importance of effective connectivity in understanding the complex dynamics of the brain network

    The design of quasi-sliding mode control for a permanent magnet synchronous motor with unmatched uncertainties

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    AbstractIn this study, the concept of a quasi-sliding mode control (QSMC) is introduced for the robust control of a permanent magnet synchronous motor (PMSM) system subjected to unmatched uncertainties, and even with input nonlinearity. On the basis of the new concept of QSMC, continuous control is obtained, to avoid the chattering phenomenon. As expected, the system state can be stabilized and driven into a predictable neighborhood of zero. Also, this approach only uses a single controller to achieve chaos control, which reduces the cost and complexity of implementation. The results of numerical simulations demonstrate the validity of the proposed QSMC design method

    The Role Of The CEO, Executive Team, And Workforce Metrics Of A Small University In The U.S.

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    The Role of the CEO, Executive Team, and Workforce Metrics of a small University in the U.S. is not just a question of academic standards. The 21st century requirements of education involve a wider set of attributes, equipping the young with social and organizational skills to cope with adult life inside and outside the workplace (Barber, 2001). It is necessary to describe the importance of aligning clear strategic priorities with workforce metric of a small university in the U.S. In addition, effective strategy execution requires a new partnership between the CEO, the workforce, and a small universityā€™s HR function. Therefore, providing insights into the execution challenge, with examples of how a small university has developed workforce and HR strategies to drive strategy execution efforts, and offering suggestions about workforce metrics might enhance the success in strategy execution

    Localized Langerhans cell histiocytosis masquerading as Brodie s abscess in a 2-year-old child: a case report

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    Langerhans cell histiocytosis (LCH), formerly known as histiocytosis X, refers to a spectrum of diseases characterized by idiopathic proliferation of histiocytes that produce either focal (localized LCH) or systemic manifestations (Handā€“SchĆ¼llerā€“Christian disease and Lettererā€“Siwe disease). Localized LCH accounts for approximately 60ā€“70 % of all LCH cases. Osseous involvement is the most common manifestation and typically involves the flat bones, along with lesions of the skull, pelvis, and ribs. Localized LCH in bone shows a wide spectrum of clinical manifestations and radiologic features that may mimic those of infections as well as benign and malignant tumors. The diagnostic imaging findings of localized LCH are also diverse and challenging. The penumbra sign is a common and characteristic magnetic resonance imaging (MRI) feature of Brodieā€™s abscess, but is rarely seen in localized LCH. In this report, we describe a case of localized LCH misdiagnosed as Brodieā€™s abscess in a 2-year-old child based on clinical symptoms, laboratory findings, and pre-diagnostic MRI findings (penumbra sign). Therefore, the penumbra sign is not sufficient to clearly establish the diagnosis of Brodieā€™s abscess, and the differential diagnosis of localized LCH should be considered when a child with an osteolytic lesion presents with a penumbra sign

    A Bayesian measurement error model for two-channel cell-based RNAi data with replicates

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    RNA interference (RNAi) is an endogenous cellular process in which small double-stranded RNAs lead to the destruction of mRNAs with complementary nucleoside sequence. With the production of RNAi libraries, large-scale RNAi screening in human cells can be conducted to identify unknown genes involved in a biological pathway. One challenge researchers face is how to deal with the multiple testing issue and the related false positive rate (FDR) and false negative rate (FNR). This paper proposes a Bayesian hierarchical measurement error model for the analysis of data from a two-channel RNAi high-throughput experiment with replicates, in which both the activity of a particular biological pathway and cell viability are monitored and the goal is to identify short hair-pin RNAs (shRNAs) that affect the pathway activity without affecting cell activity. Simulation studies demonstrate the flexibility and robustness of the Bayesian method and the benefits of having replicates in the experiment. This method is illustrated through analyzing the data from a RNAi high-throughput screening that searches for cellular factors affecting HCV replication without affecting cell viability; comparisons of the results from this HCV study and some of those reported in the literature are included.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS496 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Cyclooxygenase-2 enhances Ī±2Ī²1 integrin expression and cell migration via EP1 dependent signaling pathway in human chondrosarcoma cells

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    <p>Abstract</p> <p>Background</p> <p>Cyclooxygenase (COX)-2, the inducible isoform of prostaglandin (PG) synthase, has been implicated in tumor metastasis. Interaction of COX-2 with its specific EP receptors on the surface of cancer cells has been reported to induce cancer invasion. However, the effects of COX-2 on migration activity in human chondrosarcoma cells are mostly unknown. In this study, we examined whether COX-2 and EP interaction are involved in metastasis of human chondrosarcoma.</p> <p>Results</p> <p>We found that over-expression of COX-2 or exogenous PGE<sub>2 </sub>increased the migration of human chondrosarcoma cells. We also found that human chondrosarcoma tissues and chondrosarcoma cell lines had significant expression of the COX-2 which was higher than that in normal cartilage. By using pharmacological inhibitors or activators or genetic inhibition by the EP receptors, we discovered that the EP1 receptor but not other PGE receptors is involved in PGE<sub>2</sub>-mediated cell migration and Ī±2Ī²1 integrin expression. Furthermore, we found that human chondrosarcoma tissues expressed a higher level of EP1 receptor than normal cartilage. PGE<sub>2</sub>-mediated migration and integrin up-regulation were attenuated by phospholipase C (PLC), protein kinase C (PKC) and c-Src inhibitor. Activation of the PLCĪ², PKCĪ±, c-Src and NF-ĪŗB signaling pathway after PGE<sub>2 </sub>treatment was demonstrated, and PGE<sub>2</sub>-induced expression of integrin and migration activity were inhibited by the specific inhibitor, siRNA and mutants of PLC, PKC, c-Src and NF-ĪŗB cascades.</p> <p>Conclusions</p> <p>Our results indicated that PGE<sub>2 </sub>enhances the migration of chondrosarcoma cells by increasing Ī±2Ī²1 integrin expression through the EP1/PLC/PKCĪ±/c-Src/NF-ĪŗB signal transduction pathway.</p

    A new cable clip module with moveable cable clip

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    For a server system, we would have many kinds of configurations for customerā€™s different application. Some configurations like 2.5ā€ / 3.5ā€ HDD or different length PSU might have different PCBA, cable, mechanical part and cable clip in the chassis. It will have the partā€™s maintenance and inventory cost on these parts for different configuration. So if we could use the same part at different configuration, it will reduce our cost. So we propose a new cable clip module with moveable cable clip to let the cable routing more flexible by moving the location of the cable clip. By using this cable clip module, we could use the same cable for different configuration like different length PSU and different size HDD. And we also could use the cable clip module at the same location in the chassis for these configurations
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