245 research outputs found

    The Numerical Invariant Measure of Stochastic Differential Equations With Markovian Switching

    Full text link
    The existence and uniqueness of the numerical invariant measure of the backward Euler-Maruyama method for stochastic differential equations with Markovian switching is yielded, and it is revealed that the numerical invariant measure converges to the underlying invariant measure in the Wasserstein metric. Under the polynomial growth condition of drift term the convergence rate is estimated. The global Lipschitz condition on the drift coefficients required by Bao et al., 2016 and Yuan et al., 2005 is released. Several examples and numerical experiments are given to verify our theory.Comment: 25 pages, 4 figure

    Système participatif de tags iconiques basé sur un langage visuel instinctif multi-points de vue

    Get PDF
    Le système de tags pour un système d organisation des connaissances centralise et fournit les tags qui peuvent être utilisés pour classer, partager et rechercher des connaissances sur le web pour l utilisation personnelle ou organisationnelle. Bien que les études précédentes aient pensé à améliorer le système de tags visuels en utilisant des icônes, il existe dans ce cas le problème de reconnaissance, de mémorisation et de désorientation. Notre recherche se consacre à la recherche d'une nouvelle approche pour améliorer la représentation des tags et surtout de leur structure, dans un système où les icônes bien structurées pourront améliorer l'efficacité de tagage en considérant la qualité et la rapidité. Ce système de tags iconiques s organise sur un LVD (Langage Visuel Distinctif) lui-même basé sur le modèle Hypertopic pour la représentation de cartes de thèmes multipoints de vue développé par l équipe Tech-CICO. Cette solution est proposée pour améliorer principalement l'interprétation sémiotique du sens de l icone et renforcer la compréhension et l usage de la structure de tags dans un système informatisé de partage des connaissances, notamment pour gérer et partager les tags iconiques sur une plate-forme collaborativeTags systems for Knowledge Organization System centralize and provide the tags that can be employed in classifying, sharing and seeking knowledge on the web for personal or organizational use. However, an increased variety of vocabularies and languages cause connections between tags and documents marked by textual tags to become less and less distinctive, making the use and reuse of tags systems even harder. Although previous attempts have been made onto visual tags system by using icons, it caused the disorientation when users facing with plant of isolated symbols. Our research dedicates to searching a new approach to improve the representation of tags and their structure in a tags system, where well-structured icons enhance the tagging effectiveness by considering tagging quality and tagging speed. The LVD (Visual Distinctive Language)-based iconic tags system is proposed and presented in this thesis to bring amelioration mainly from semiotic interpretation of tag meaning and graphical code of tag structure. The arrangement of icons is as well another interesting topic that was deal with in our research to offers a more complete definition of iconic tags system. Apart from modeling and evaluating the LVD-based iconic tags system we have considered the way to build up such icon system in today s cooperative knowledge sharing context and made it possible to manage and share iconic tags on a collaborative plate-formTROYES-SCD-UTT (103872102) / SudocSudocFranceF

    Rabies Surveillance Identifies Potential Risk Corridors and Enables Management Evaluation

    Get PDF
    Intensive efforts are being made to eliminate the raccoon variant of rabies virus (RABV) from the eastern United States and Canada. The United States Department of Agriculture (USDA) Wildlife Services National Rabies Management Program has implemented enhanced rabies surveillance (ERS) to improve case detection across the extent of the raccoon oral rabies vaccination (ORV) management area. We evaluated ERS and public health surveillance data from 2006 to 2017 in three northeastern USA states using a dynamic occupancy modeling approach. Our objectives were to examine potential risk corridors for RABV incursion from the U.S. into Canada, evaluate the effectiveness of ORV management strategies, and identify surveillance gaps. ORV management has resulted in a decrease in RABV cases over time within vaccination zones (from occupancy (ψ) of 0.60 standard error (SE) = 0.03 in the spring of 2006 to ψ of 0.33 SE = 0.10 in the spring 2017). RABV cases also reduced in the enzootic area (from ψ of 0.60 SE = 0.03 in the spring of 2006 to ψ of 0.45 SE = 0.05 in the spring 2017). Although RABV occurrence was related to habitat type, greater impacts were associated with ORV and trap–vaccinate–release (TVR) campaigns, in addition to seasonal and yearly trends. Reductions in RABV occupancy were more pronounced in areas treated with Ontario Rabies Vaccine Bait (ONRAB) compared to RABORAL V-RG®. Our approach tracked changes in RABV occurrence across space and time, identified risk corridors for potential incursions into Canada, and highlighted surveillance gaps, while evaluating the impacts of management actions. Using this approach, we are able to provide guidance for future RABV management

    Altered Resting-State Functional Activity in Medication-Naive Patients With First-Episode Major Depression Disorder vs. Healthy Control: A Quantitative Meta-Analysis

    Get PDF
    Background: There is an urgent need for a meta-analysis that characterizes the brain states of major depression disorder (MDD) patients and potentially provides reliable biomarkers, because heterogeneity in the results of resting-state functional neuroimaging has been observed between studies, with some patients not showing the consistent changes, or even opposite patterns. Thus, we evaluated consistent regional brain activity alterations in medication-naive patients with first-episode unipolar MDD and compared the results with those in healthy controls (HCs).Methods: A systematic database search was conducted (in PubMed, Ovid, and Web of Knowledge) between January 1984 and July 2016 to select resting-state functional activity studies with a voxel-wise analysis in MDD. We used anisotropic effect size-signed differential mapping to perform a whole-brain meta-analysis, comparing functional alterations between first-episode medication-naive unipolar MDD patients and HCs by integrating the studies. In addition, subgroup meta-analysis was conducted to control for the MRI analysis method. Moreover, the meta-regression analyses were performed to examine the potential effects of mean age, education duration, illness duration, and severity of depressive symptoms.Results: A total of 12 studies were included, comparing 313 MDD patients with 283 HCs. The pooled and subgroup meta-analysis found that the MDD patients showed hyperactivity in the left parahippocampal gyrus, left supplementary motor area, left amygdala, left hippocampus, and left middle frontal gyrus (MFG; orbital part), and hypoactivity in the left lingual gyrus, left middle occipital gyrus, right cuneus cortex, right MFG (orbital part), and left cerebellum. In the meta-regression analyses, the mean illness duration was positively associated with hyper-activation in the left parahippocampal gyrus and hypoactivation in the hemispheric lobule IV/V of the left cerebellum.Conclusions: This meta-analysis indicated that MDD patients had significant and robust resting-state brain activity alteration in amygdala, left hippocampus and other regions, which implicated this finding in the pathophysiology of cognitive and emotional impairment in MDD patients

    Comparison of Diagnostic Performance of Three-Dimensional Positron Emission Mammography versus Whole Body Positron Emission Tomography in Breast Cancer

    Get PDF
    Objective. To compare the diagnostic performance of three-dimensional (3D) positron emission mammography (PEM) versus whole body positron emission tomography (WBPET) for breast cancer. Methods. A total of 410 women with normal breast or benign or highly suspicious malignant tumors were randomized at 1 : 1 ratio to undergo 3D-PEM followed by WBPET or WBPET followed by 3D-PEM. Lumpectomy or mastectomy was performed on eligible participants after the scanning. Results. The sensitivity and specificity of 3D-PEM were 92.8% and 54.5%, respectively. WBPET showed a sensitivity of 95.7% and specificity of 56.8%. After exclusion of the patients with lesions beyond the detecting range of the 3D-PEM instrument, 3D-PEM showed higher sensitivity than WBPET (97.0% versus 95.5%, P = 0.913), particularly for small lesions (<1 cm) (72.0% versus 60.0%, P = 0.685). Conclusions. The 3D-PEM appears more sensitive to small lesions than WBPET but may fail to detect lesions that are beyond the detecting range. This study was approved by the Ethics Committee (E2012052) at the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China). The instrument positron emission mammography (PEMi) was approved by China State Food and Drug Administration under the registration number 20153331166

    Exploratory analysis of high-dose corticosteroid therapy on epileptic encephalopathy with spike-and-wave activation in sleep

    Get PDF
    ObjectiveThis study aims to evaluate the therapeutic efficacy of high-dose corticosteroid therapy in children diagnosed with epileptic encephalopathy with spike-and-wave activation in sleep (EE-SWAS), investigate associated clinical indicators influencing treatment outcomes, and establish a predictive model for recurrence.MethodsChildren diagnosed with EE-SWAS who received high-dose corticosteroid therapy were categorized into responder group and non-responder group. Data on clinical parameters, electroencephalogram (EEG) features, and serum cytokine levels were collected. Six months post-treatment, the effectively treated children were further stratified into recurrence and non-recurrence groups. Risk factors for poor outcomes following corticosteroid therapy were identified using univariate analysis. Multivariate logistic regression analysis was then employed to determine independent factors influencing the recurrence of corticosteroid therapy, which facilitated the development of a predictive model.ResultsThe study included 48 children, with 33 cases in the responder group (effective rate = 68.8%) and 15 cases in the non-responder group. The responder group exhibited an older onset age of electrical status epilepticus in sleep (ESES) and higher proportions of combined benzodiazepines (BZDs) use (P &lt; 0.05). Among those responding to corticosteroid therapy, 11 cases experienced a recurrence (recurrence rate = 33.3%), while 22 cases did not. Significant differences were observed between the two groups concerning age of seizure onset, age of ESES onset, seizure frequency, atypical presentations, and concomitant frontal lobe discharges (all P &lt; 0.05). Concomitant frontal lobe discharges and an earlier age of seizure onset were identified as risk factors for ESES recurrence following corticosteroid therapy. The predictive model was formulated as Logit(P) = 2.35 × presence of frontal lobe discharges—0.802 × age of seizure onset + 2.457. The Area Under the Curve (AUC) of Receiver Operating Characteristics (ROC) was 0.93, with sensitivity and specificity at 100% and 77.3%, respectively.ConclusionHigh-dose corticosteroid therapy for EE-SWAS exhibited a high effective rate as well as a notable recurrence rate. Onset age of ESES and combined benzodiazepines usage correlated with therapeutic efficacy. Seizure onset age and the presence of frontal lobe discharges may hold predictive value for recurrence following corticosteroid therapy

    Analysis of main taste substances and sensory evaluation of Shuixian Wuyi rock tea narcissus in different years

    Get PDF
    [Objective] This study aimed to investigate the correlation between taste substances and flavor presentation intensity of Shuixian Wuyi rock tea from different storage years. [Methods] The main taste substances, including tea polyphenols, flavonoids, free amino acids, soluble sugars, catechins and other components, were detected in several years of Narcissus (2022, 2018, 2016, 2014, 2012, 2010, 2008, 2006 for storage 1, 3, 5, 7, 9, 11, 13, 15 years, respectively) by using chemical methods and high-performance liquid chromatography, and the reasons for the change of the two and their correlation were analyzed by combining with the sensory evaluation of the electronic tongue. [Results] With the increase of storage year, the contents of tea polyphenols, soluble sugars, and catechins in Narcissus showed a decreasing trend, the total flavonoids and free amino acids showed an inconspicuous trend, and the contents of caffeine, gallic acid, and theaflavin increased in general. Its freshness showed an increasing trend, richness, bitterness, astringency, and its aftertaste showed a decreasing trend, while the salty and sweet tastes fluctuated up and down within a certain level. [Conclusion] EGCG of Shuixian in different years showed a strong positive correlation with a bitter taste, astringent aftertaste, and richness, while EGC showed a strong negative correlation with sourness, TF, and astringency
    • …
    corecore