SiZer for time series: A new approach to the analysis of trends

Smoothing methods and SiZer are a useful statistical tool for discovering statistically significant structure in data. Based on scale space ideas originally developed in the computer vision literature, SiZer (SIgnificant ZERo crossing of the derivatives) is a graphical device to assess which observed features are `really there' and which are just spurious sampling artifacts. In this paper, we develop SiZer like ideas in time series analysis to address the important issue of significance of trends. This is not a straightforward extension, since one data set does not contain the information needed to distinguish `trend' from `dependence'. A new visualization is proposed, which shows the statistician the range of trade-offs that are available. Simulation and real data results illustrate the effectiveness of the method.Comment: Published at http://dx.doi.org/10.1214/07-EJS006 in the Electronic Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of Mathematical Statistics (http://www.imstat.org

CONNESSIONI COMUNITARIE. LE TECNOLOGIE DI COMUNITA' NEI CONTESTI ECCLESIALI

La ricerca affronta il tema di come le tecnologie di comunità possano essere integrate nel lavoro socio-educativo, e in particolare nell’agire pastorale delle realtà ecclesiali, al fine di generare nuovi legami sociali o di rafforzare gli esistenti. Dopo un affondo teorico sul costrutto di comunità e la messa in luce del significato che ha assunto nel corso dello sviluppo delle scienze umane, il lavoro di ricerca si è concretizzato nell’attivazione e nell’animazione di una comunità autoriale (online e in presenza) capace di produrre riflessioni a partire dall’esperienza sul campo. La ricerca desidera approfondire quanto accaduto durante la sperimentazione del paradigma delle tecnologie di comunità in contesti ecclesiali. Durante la ricerca sono state raccolte le informazioni in maniera sequenziale e in fase di analisi si è proceduto con l’integrazione dei dati qualitativi e quantitativi. Gli obiettivi che si è posti sono stati: indagare la riflessività nelle pratiche pastorali in relazione al senso di comunità; analizzare la capacità di generare tramite le tecnologie un tessuto connettivo comunitario tra differenti gruppi parrocchiali; accompagnare i partecipanti della sperimentazione a progettare interventi educativi capaci di sfruttare non solo la dimensione informativa-organizzativa delle tecnologie, ma anche quella connettiva-relazionale.The research aims at exploring the ways in which community technologies can be integrated into socio-educational activities. In particular, the research investigates how the incorporation of these technologies in support of pastoral actions in ecclesial contexts may enable the development of new social connections or strengthen existing ones. The first part of the research investigates the concept of community through the lens of social sciences. The second part of this study engages with the analysis of case studies to test the applicability of the community technologies paradigm in ecclesial contexts. Through participant observation, this research aimed at investigating the steps that a pastoral community needs to take in order to activate its presence online and integrate it with face-to-face activities. The research involved the collection of quantitative data through the administration of standardized surveys, which was implemented by individual interviews and focus groups. The research objectives included investigating reflexivity in pastoral practices in relation to the sense of community; analyzing the ability to generate a community connective network between different parish groups using technologies; assisting the participants in planning the educational interventions to carry out both in the information-organizational aspect of the technologies, as well as in the connective-relational aspect

Small-bowel capsule endoscopy with panoramic view: results of the first multicenter, observational study (with videos).

BACKGROUND AND AIMS: The first small-bowel video-capsule endoscopy (VCE) with 360° panoramic view has been recently developed. This new capsule has a wire-free technology, 4 high frame-rate cameras, and a long-lasting battery life. The present study was aimed at assessing performances and the safety profile of the 360° panoramic-view capsule in a large series of patients from a multicenter clinical practice setting. METHODS: Consecutive patients undergoing a 360° panoramic-view capsule procedure in 7 European Institutions between January 2011 and November 2015 were included. Both technical (ie, technical failures, completion rate) and clinical (ie, indication, findings, retention rate) data were collected by means of a structured questionnaire. VCE findings were classified according to the likelihood to explain reason for referral: P0-low, P1-intermediate and P2-high. RESULTS: Among 172 patients (94 men; median age: 68 years, IQR: 53-75), 142 underwent VCE for obscure (32 overt, 110 occult) GI bleeding (OGIB) and 28 for suspected (17) or established (2) Crohn's disease (CD). Overall, 560 findings were detected; 252 of them were P2. The overall diagnostic yield was 40.1%; 42.2% and 30.0% in patients with OGIB and CD, respectively. The rate of complete enteroscopy was 90.2%. All of the patients but one, who experienced capsule retention (1/172: 0.6%), excreted and retrieved the capsule. VCE failure occurred in 4 of 172 (2.3%) cases for technical problems. CONCLUSION: The present multicenter study, conducted in clinical practice setting and based on a large consecutive series of patients, showed that DY and safety profile of 360° panoramic-view capsule are similar to those of forward-view VCEs

Rôle actuel de la capsule endoscopique dans la détection des tumeurs néoplasiques de l’intestin grêle

Although small-bowel tumors are a small proportion of gastrointestinal neoplasms recent studies suggest that the incidence of these diseases is increasing. In fact, using new diagnostic modalities, their frequency has been shown to be slightly superior than previously thought. Until recently, diagnosis and management of these tumors were delayed by the difficult of access to the small bowel and the poor diagnostic capabilities of the available diagnostic techniques. An array of new methods has recently been developed, increasing the possibility of detecting these tumors at an earlier stage. In this particular subset of patients capsule endoscopy, despite its possible limitations, may provide crucial information changing the subsequent patient management and possibly influencing the long-term clinical outcome.Bien que les tumeurs de l’intestin grêle ne représentent qu’une faible proportion des lésions néoplasiques du tractus digestif, de récentes études ont mis en évidence une légère augmentation de leur incidence. En fait, grâce aux nouvelles modalités diagnostiques, leur fréquence s’est avérée légèrement supérieure à ce qui était précédemment rapporté. Jusqu’à très récemment, le diagnostic et la prise en charge de ces tumeurs étaient retardés en raison d’un accès difficile à l’intestin grêle et aux faibles capacités diagnostiques des moyens techniques disponibles. Tout un éventail de nouvelles méthodes ont récemment été mises au point, améliorant la possibilité de détecter ces lésions à un stade plus précoce. Pour cette catégorie spécifique de patients avec lésions de l’intestin grêle, la capsule endoscopique, en dépit de ses limites, peut fournir une information cruciale influant par conséquent sur la prise en charge du patient et sur les résultats cliniques au long cours

Dependent SiZer: Goodness-of-Fit Tests for Time Series Models

In this paper, we extend SiZer (SIgnificant ZERo crossing of the derivatives) to dependent data for the purpose of goodness of fit tests for time series models. Dependent SiZer compares the observed data with a specific null model being tested by adjusting the statistical inference using an assumed autocovariance function. This new approach uses a SiZer type visualization to flag statistically significant differences between the data and a given null model. The power of this approach is demonstrated through some examples of time series of Internet traffic data. It is seen that such time series can have even more burstiness than is predicted by the popular, long range dependent, Fractional Gaussian Noise model

Recent developments in small bowel endoscopy: the “black box” is now open!

Over the last few years, capsule endoscopy has been established as a fundamental device in the practicing gastroenterologist’s toolbox. Its utilization in diagnostic algorithms for suspected small bowel bleeding, Crohn’s disease, and small bowel tumors has been approved by several guidelines. The advent of double-balloon enteroscopy has significantly increased the therapeutic possibilities and release of multiple devices (single-balloon enteroscopy and spiral enteroscopy) aimed at improving the performance of small bowel enteroscopy. Recently, some important innovations have appeared in the small bowel endoscopy scene, providing further improvement to its evolution. Artificial intelligence in capsule endoscopy should increase diagnostic accuracy and reading efficiency, and the introduction of motorized spiral enteroscopy into clinical practice could also improve the therapeutic yield. This review focuses on the most recent studies on artificial-intelligence-assisted capsule endoscopy and motorized spiral enteroscopy

Terminal ileum ileoscopy and histology in patients undergoing high-definition colonoscopy with virtual chromoendoscopy for chronic nonbloody diarrhea : a prospective, multicenter study

Background and aims: Ileo-colonoscopy is the procedure of choice for chronic nonbloody diarrhea (CNBD) of unknown origin. Histological evaluation at different colonic sites is mandatory to assess the presence of microscopic colitis. However, the value of routine ileal biopsy on normal-appearing mucosa as assessed by means of standard-resolution white-light ileoscopy is controversial given its reported low diagnostic yield. Hence, we have assessed for the first time the accuracy of retrograde ileoscopy using high-definition and dyeless chromoendoscopy (HD + DLC), thereby calculating the impact and cost of routine ileal biopsy in CNBD. Methods: Patients with CNBD of unknown origin were prospectively enrolled for ileo-colonoscopy with HD + DLC at five referral centers. Multiple biopsies were systematically performed on each colorectal segment and in the terminal ileum for histopathological analysis. Results: Between 2014 and 2017, 546 consecutive patients were recruited. Retrograde ileoscopy success rate was 97.6%. A total of 492 patients (mean age: 53 \ub1 18 years) fulfilled all the inclusion criteria: Following endoscopic and histopathological work-up, 7% had lymphoid nodular hyperplasia and 3% had isolated ileitis. Compared to the histopathology as the gold standard, retrograde ileoscopy with HD + DLC showed 93% sensitivity, 98% specificity and 99.8% negative predictive value. In patients with normal ileo-colonoscopy, ileum histology had no diagnostic gain and resulted in a cost of US $26.5 per patient. Conclusions: Retrograde ileoscopy with HD + DLC predicts the presence of ileitis in CNBD with excellent performance. The histopathological evaluation of the terminal ileum is the gold standard for the diagnostic assessment of visible lesions but has no added diagnostic value in CNBD patients with negative ileo-colonoscopy inspection using modern endoscopic imaging techniques