278 research outputs found

    Investigating the Relationship between Effectiveness of App Evolution and App Continuance Intention: An Empirical Study of the U.S. App Market

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    App evolution has been shown to continuously lead to app success from the developer perspective. However, few studies have explored app success from the user perspective, which limits our understanding of the role of app evolution in app success. Building on app evolution literature and the technology acceptance model (TAM), the authors investigate the influence of the effectiveness of app evolution on users’ perceived app usefulness and ease of use and their app continuance intention, which is a proxy of app success from the user perspective. Survey data were collected from 299 app users on both the Google Play and AppStore platforms in the U.S. The findings indicate that the effectiveness of strategic evolution and effectiveness of evolution speed directly affect a user’s perceived app usefulness, while effectiveness of operational evolution and effectiveness of evolution speed directly affect a user’s perceived app ease of use. In addition, perceived app usefulness and perceived app ease of use are two keys that lead to users’ app continuance intention. A user’s perceived app ease of use affects app continuance intention both directly and indirectly through perceived app usefulness. This study enhances our understanding of the relationship between effectiveness of app evolution and app continuance intention. This is especially important in helping app developers that are small firms or startups with limited resources understand how to retain app users. Limitations and directions for future research are also discussed

    Investigating the Relationship between the Effectiveness of App Evolution and App Continuance Intention: An Empirical Study of the U.S. App Market

    Get PDF
    Researchers have shown app evolution to continuously lead to app success from the developer perspective. However, few studies have explored app success from the user perspective, which limits our knowledge about the role that app evolution has in app success. Building on app evolution literature and the technology acceptance model (TAM), we investigate the influence that effectiveness of app evolution has on perceived app usefulness, perceived ease of use, and app continuance intention (a proxy for app success from the user perspective). We collected survey data from 299 app users on both the Google Play and Apple’s App Store platforms in the United States. Our findings indicate that effectiveness of strategic evolution and effectiveness of evolution speed directly affect perceived app usefulness, while effectiveness of operational evolution and effectiveness of evolution speed directly affect perceived app ease of use. In addition, perceived app usefulness and perceived app ease of use constitute two key factors that lead to app continuance intention. Perceived ease of use affects users’ app continuance intention both directly and indirectly through perceived app usefulness. This study enhances our knowledge about the relationship between effectiveness of app evolution and app continuance intention. Such knowledge has particular importance in helping small firms or startups with limited resources understand how to retain app users. We also discuss limitations and directions for future research

    The Impact Of Knowledge From Learning-About Electronic Health Records On It Innovation Adoption: The Moderating Role Of Absorptive Capacity

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    Learning-by-doing is a crucial process to successful IT adoption. Yet, this type of organizational learning process is necessary but not sufficient to the adoption success. Learning-about, the pre-adoption learning activity, plays an equally important role in an organization’s IT adoption. In healthcare industry, hospitals are not always able to utilize healthcare information technologies (HITs), such as electronic healthcare records (EHRs), to generate high quality information for decision making. Having pre-adoption knowledge and the capacity to absorb the knowledge is likely to better the adoption results. This research proposes a conceptual model to explain the importance of the knowledge from learning-about EHR technology and explore the role absorptive capacity plays in EHR pre-adoption. This study contributes to the existing EHR literature by (1) adding pre-adoption knowledge into the ingredients of successful adoption, and (2) discussing the moderating effect of absorptive capacity to the relationship between pre-adoption knowledge and outcomes of adoption

    TrustGuard: GNN-based Robust and Explainable Trust Evaluation with Dynamicity Support

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    Trust evaluation assesses trust relationships between entities and facilitates decision-making. Machine Learning (ML) shows great potential for trust evaluation owing to its learning capabilities. In recent years, Graph Neural Networks (GNNs), as a new ML paradigm, have demonstrated superiority in dealing with graph data. This has motivated researchers to explore their use in trust evaluation, as trust relationships among entities can be modeled as a graph. However, current trust evaluation methods that employ GNNs fail to fully satisfy the dynamicity nature of trust, overlook the adverse effects of attacks on trust evaluation, and cannot provide convincing explanations on evaluation results. To address these problems, in this paper, we propose TrustGuard, a GNN-based accurate trust evaluation model that supports trust dynamicity, is robust against typical attacks, and provides explanations through visualization. Specifically, TrustGuard is designed with a layered architecture that contains a snapshot input layer, a spatial aggregation layer, a temporal aggregation layer, and a prediction layer. Among them, the spatial aggregation layer can be plugged into a defense mechanism for a robust aggregation of local trust relationships, and the temporal aggregation layer applies an attention mechanism for effective learning of temporal patterns. Extensive experiments on two real-world datasets show that TrustGuard outperforms state-of-the-art GNN-based trust evaluation models with respect to trust prediction across single-timeslot and multi-timeslot, even in the presence of attacks. In particular, TrustGuard can explain its evaluation results by visualizing both spatial and temporal views

    A Unified Framework for Modality-Agnostic Deepfakes Detection

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    As AI-generated content (AIGC) thrives, deepfakes have expanded from single-modality falsification to cross-modal fake content creation, where either audio or visual components can be manipulated. While using two unimodal detectors can detect audio-visual deepfakes, cross-modal forgery clues could be overlooked. Existing multimodal deepfake detection methods typically establish correspondence between the audio and visual modalities for binary real/fake classification, and require the co-occurrence of both modalities. However, in real-world multi-modal applications, missing modality scenarios may occur where either modality is unavailable. In such cases, audio-visual detection methods are less practical than two independent unimodal methods. Consequently, the detector can not always obtain the number or type of manipulated modalities beforehand, necessitating a fake-modality-agnostic audio-visual detector. In this work, we introduce a comprehensive framework that is agnostic to fake modalities, which facilitates the identification of multimodal deepfakes and handles situations with missing modalities, regardless of the manipulations embedded in audio, video, or even cross-modal forms. To enhance the modeling of cross-modal forgery clues, we employ audio-visual speech recognition (AVSR) as a preliminary task. This efficiently extracts speech correlations across modalities, a feature challenging for deepfakes to replicate. Additionally, we propose a dual-label detection approach that follows the structure of AVSR to support the independent detection of each modality. Extensive experiments on three audio-visual datasets show that our scheme outperforms state-of-the-art detection methods with promising performance on modality-agnostic audio/video deepfakes.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

    Nomogram based on computed tomography images and clinical data for distinguishing between primary intestinal lymphoma and Crohn’s disease: a retrospective multicenter study

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    BackgroundDifferential diagnosis of primary intestinal lymphoma (PIL) and Crohn’s disease (CD) is a challenge in clinical diagnosis.AimsTo investigate the validity of the nomogram based on clinical and computed tomography (CT) features to identify PIL and CD.MethodsThis study retrospectively analyzed laboratory parameters, demographic characteristics, clinical manifestations, and CT imaging features of PIL and CD patients from two centers. Univariate logistic analysis was performed for each variable, and laboratory parameter model, clinical model and imaging features model were developed separately. Finally, a nomogram was established. All models were evaluated using the area under the curve (AUC), accuracy, sensitivity, specificity, and decision curve analysis (DCA).ResultsThis study collected data from 121 patients (PIL = 69, CD = 52) from Center 1. Data from 43 patients (PIL = 24, CD = 19) were collected at Center 2 as an external validation cohort to validate the robustness of the model. Three models and a nomogram were developed to distinguish PIL from CD. Most models performed well from the external validation cohort. The nomogram showed the best performance with an AUC of 0.921 (95% CI: 0.838–1.000) and sensitivities, specificities, and accuracies of 0.945, 0.792, and 0.860, respectively.ConclusionA nomogram combining clinical data and imaging features was constructed, which can effectively distinguish PIL from CD

    Didymin improves UV irradiation resistance in C. elegans

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    Didymin, a type of flavono-o-glycoside compound naturally present in citrus fruits, has been reported to be an effective anticancer agent. However, its effects on stress resistance are unclear. In this study, we treated Caenorhabditis elegans with didymin at several concentrations. We found that didymin reduced the effects of UV stressor on nematodes by decreasing reactive oxygen species levels and increasing superoxide dismutase (SOD) activity. Furthermore, we found that specific didymin-treated mutant nematodes daf-16(mu86) & daf-2(e1370), daf-16(mu86), akt-1(ok525), akt-2(ok393), and age-1(hx546) were susceptible to UV irradiation, whereas daf-2(e1371) was resistant to UV irradiation. In addition, we found that didymin not only promoted DAF-16 to transfer from cytoplasm to nucleus, but also increased both protein and mRNA expression levels of SOD-3 and HSP-16.2 after UV irradiation. Our results show that didymin affects UV irradiation resistance and it may act on daf-2 to regulate downstream genes through the insulin/IGF-1-like signaling pathway

    Effects of Ultrasonic and Microwave Pretreatments on Calcium Chelating Capacity, Structure and Stability of Walnut Meal Protein Peptides

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    In this study, a mixture of ultrasound or microwave pretreated walnut meal protein peptides and CaCl2 was used for the preparation of walnut peptide-calcium chelate. The effects of different pretreatments on the calcium chelating capacity, structural changes and stability of walnut meal protein peptides were analyzed. The results showed that compared with walnut meal protein peptide-calcium chelate (WPP-Ca), the chelation rates of ultrasound-pretreated walnut meal protein peptide-calcium chelate (UP-WPP-Ca) and microwave-pretreated walnut meal protein peptide-calcium chelate (MP-WPP-Ca) were enhanced, which indicated that ultrasound and microwave pretreatments improved the calcium-chelating capacity of the peptides effectively. Using ultraviolet-visible (UV-Vis) absorption spectroscopy and Fourier transform infrared (FTIR) spectroscopy, it was found that ultrasound and microwave pretreatments mainly affected the calcium ion binding sites such as amino groups, carbonyl groups, carboxyl groups, amide bonds and carboxylate groups of walnut meal protein peptides. The results of X-ray diffraction (XRD) showed that ultrasound and microwave treatments changed the molecular arrangement of walnut meal protein peptides, thereby making the structure of walnut peptide-calcium chelate more ordered. Fluorescence spectroscopy showed that ultrasonic and microwave treatments promoted the chelation between aromatic amino acids and calcium ions. In addition, UP-WPP-Ca and MP-WPP-Ca showed good stability toward different pH values, temperatures, and gastrointestinal digestion. In short, ultrasonic and microwave pretreatments can improve the calcium-chelating capacity and stability of walnut meal protein peptides, which is of guiding significance for the processing of walnut peptide-calcium chelate and the development of calcium supplements
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