582 research outputs found

    Hospital-free Days as an Outcome for Trials Among Critically and Seriously Ill Patients: Defining and Estimating Treatment Effects

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    Hospital-free days (HFD) is a composite outcome combining information on mortality and hospitalization. There has been increasing popularity in using HFD for studying the effects of interventions among critically and seriously ill patients. However, to date, no study has critically evaluated the statistical methods for analyzing this composite outcome. This thesis formally defines the marginal treatment effect for the HFD composite outcome, difference in mean HFD across treatment groups, and compares it to the treatment effect for the competitor rank-based composite score. Three ways of visualizing data from studies using HFD are proposed which improve understanding of treatment mechanisms and can be used for planning future studies. For studies enrolling hospitalized patients, the statistical performance of eight parametric estimators are evaluated against a simple estimator (difference in sample means) under four treatment effect scenarios. For studies enrolling non-hospitalized patients, four parametric estimators are evaluated against the simple estimator under the four treatment effect scenarios. Using our data generating mechanism which is designed to mimic daily patterns of hospitalization and mortality in seriously ill patients, we find that in most scenarios we consider both the simple estimator and the estimators derived from parametric models are unbiased; however, the parametric models often suffer from inflated or conservative Type I Error rates driven by the fact that the variance assumed by the parametric model is not consistent with the data. In addition, among estimators that maintained the nominal 5\% Type I Error rate, the simple estimator has power comparable to the estimators based on parametric models. Therefore, we suggest the use of the simple estimator for estimating the marginal treatment effect based on its statistical properties as well as the ability to harmonize statistical analyses and results across future studies. Researchers who adopt parametric models for HFD should utilize a bootstrap procedure to generate valid standard errors for test statistics or confidence intervals

    SD-GAN: Semantic Decomposition for Face Image Synthesis with Discrete Attribute

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    Manipulating latent code in generative adversarial networks (GANs) for facial image synthesis mainly focuses on continuous attribute synthesis (e.g., age, pose and emotion), while discrete attribute synthesis (like face mask and eyeglasses) receives less attention. Directly applying existing works to facial discrete attributes may cause inaccurate results. In this work, we propose an innovative framework to tackle challenging facial discrete attribute synthesis via semantic decomposing, dubbed SD-GAN. To be concrete, we explicitly decompose the discrete attribute representation into two components, i.e. the semantic prior basis and offset latent representation. The semantic prior basis shows an initializing direction for manipulating face representation in the latent space. The offset latent presentation obtained by 3D-aware semantic fusion network is proposed to adjust prior basis. In addition, the fusion network integrates 3D embedding for better identity preservation and discrete attribute synthesis. The combination of prior basis and offset latent representation enable our method to synthesize photo-realistic face images with discrete attributes. Notably, we construct a large and valuable dataset MEGN (Face Mask and Eyeglasses images crawled from Google and Naver) for completing the lack of discrete attributes in the existing dataset. Extensive qualitative and quantitative experiments demonstrate the state-of-the-art performance of our method. Our code is available at: https://github.com/MontaEllis/SD-GAN.Comment: 16 pages, 12 figures, Accepted by ACM MM202

    Microcirculatory changes identified by photoacoustic microscopy in patients with complex regional pain syndrome type I after stellate ganglion blocks

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    Complex regional pain syndrome (CRPS) is a chronic pain syndrome that causes intractable pain, disability, and poor quality of life for patients. The etiology and pathophysiology of CRPS are still poorly understood. Due to a lack of proper diagnostic tools, the prognosis of CRPS is primarily based on clinical observation. The objective of this work is to evaluate a new imaging modality, photoacoustic microscopy (PAM), for assisting diagnoses and monitoring the progress and treatment outcome of CRPS. Blood vasculature and oxygen saturation (sO_2) were imaged by PAM from eight adult patients with CRPS-1. Patients’ hands and cuticles were imaged both before and after stellate ganglion block (SGB) for comparison. For all patients, both vascular structure and sO_2 could be assessed by PAM. In addition, more vessels and stronger signals were observed after SGB. The results show that PAM can help diagnose and monitor CRPS

    Aphid Performance Changes with Plant Defense Mediated by \u3cem\u3eCucumber mosaic virus\u3c/em\u3e Titer

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    Background: Cucumber mosaic virus (CMV) causes appreciable losses in vegetables, ornamentals and agricultural crops. The green peach aphid, Myzus persicae Sulzer (Aphididae) is one of the most efficient vectors for CMV. The transmission ecology of aphid-vectored CMV has been well investigated. However, the detailed description of the dynamic change in the plant-CMV-aphid interaction associated with plant defense and virus epidemics is not well known. Results: In this report, we investigated the relationship of virus titer with plant defense of salicylic acid (SA) and jasmonic acid (JA) during the different infection time and their interaction with aphids in CMV-infected tobacco plants. Our results showed that aphid performance changed with virus titer and plant defense on CMV-inoculated plants. At first, plant defense was low and aphid number increased gradually. The plant defense of SA signaling pathway was induced when virus titer was at a high level, and aphid performance was correspondingly reduced. Additionally, the winged aphids were increased. Conclusion: Our results showed that aphid performance was reduced due to the induced plant defense mediated by Cucumber mosaic virus titer. Additionally, some wingless aphids became to winged aphids. In this way CMV could be transmitted with the migration of winged aphids. We should take measures to prevent aphids in the early stage of their occurrence in the field to prevent virus outbreak

    Detection and Epidemic Dynamic of ToCV and CCYV with \u3cem\u3eBemisia tabaci\u3c/em\u3e and Weed in Hainan of China

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    Background: In recent years, two of the crinivirus, Tomato chlorosis virus (ToCV) and Cucurbit chlorotic yellows virus (CCYV) have gained increasing attention due to their rapid spread and devastating impacts on vegetable production worldwide. Both of these viruses are transmitted by the sweet potato whitefly, Bemisia tabaci (Gennadius), in a semi-persistent manner. Up to now, there is still lack of report in Hainan, the south of China. Methods: We used observational and experimental methods to explore the prevalence and incidence dynamic of CCYV and ToCV transmitted by whiteflies in Hainan of China. Results: In 2016, the chlorosis symptom was observed in the tomato and cucumber plants with a large number of B. tabaci on the infected leaves in Hainan, China, with the incidence rate of 69.8% and 62.6% on tomato and cucumber, respectively. Based on molecular identification, Q biotype was determined with a viruliferous rate of 65.0% and 55.0% on the tomato and cucumber plants, respectively. The weed, Alternanthera philoxeroides near the tomato and cucumber was co-infected by the two viruses. Furthermore, incidence dynamic of ToCV and CCYV showed a close relationship with the weed, Alternanthera philoxeroides, which is widely distributed in Hainan. Conclusion: Our results firstly reveal that the weed, A. philoxeroides is infected by both ToCV and CCYV. Besides, whiteflies showed a high viruliferous rate of ToCV and CCYV. Hainan is an extremely important vegetable production and seed breeding center in China. If the whitefly can carry these two viruses concurrently, co-infection in their mutual host plants can lead to devastating losses in the near future
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