872 research outputs found
Remodeling of Abdominal Aortic Angulation and Curvature After Endovascular Aneurysm Repair in Patients With vs Without Late Type Ia Endoleak or Endograft Migration
Purpose: To investigate aortic remodeling of the supra- and infrarenal aorta from preoperative to 1 month and midterm follow-up after endovascular aneurysm repair (EVAR) by analyzing changes in angulation and curvature in patients with vs without late type Ia endoleak or device migration. Materials and Methods: From a multicenter database, 35 patients (mean age 76 +/- 5 years; 31 men) were identified with late (>1 year) type Ia endoleak or endograft migration (>= 10 mm) and defined as the complication group. The control group consisted of 53 patients (mean age 75 +/- 7 years; 48 men) with >1-year computed tomography angiography (CTA) follow-up and no evidence of endoleaks. Suprarenal and infrarenal angles were measured on centerline reconstructions of the preoperative, 1-month, and midterm CTA scans. The value and location relative to baseline of maximum suprarenal and infrarenal curvature were determined semiautomatically using dedicated software. Changes were determined at 1 month compared with the preoperative CTA and at midterm compared with 1 month. Results: Preoperative suprarenal angulation was significantly greater in the complication group compared to the controls (34 degrees +/- 18 degrees vs 24 degrees +/- 17 degrees, p=0.008). It decreased significantly at 1 month in the complication group (29 degrees +/- 16 degrees, p=0.011) and at midterm follow-up in the controls (20 degrees +/- 19 degrees, p Conclusion: At midterm follow-up, significant differences in supra- and infrarenal angulation and curvature were observed between patients with vs without type Ia endoleak or migration. The location of the maximum curvature shifted distally in patients with complications. The aortic morphology is more stable during midterm follow-up in the patients without endoleaks
The relation between endothelial dependent flow mediated dilation of the brachial artery and coronary collateral development – a cross sectional study
<p>Abstract</p> <p>Background</p> <p>Endothelial dysfunction is thought to be a potential mechanism for the decreased presence of coronary collaterals. The aim of the study was to investigate the association between systemic endothelial function and the extent of coronary collaterals.</p> <p>Methods</p> <p>We investigated the association between endothelial function assessed via flow mediated dilation (FMD) of the brachial artery following reactive hyperemia and the extent of coronary collaterals graded from 0 to 3 according to Rentrop classification in a cohort of 171 consecutive patients who had high grade coronary stenosis or occlusion on their angiograms.</p> <p>Results</p> <p>Mean age was 61 years and 75% were males. Of the 171 patients 88 (51%) had well developed collaterals (grades of 2 or 3) whereas 83 (49%) had impaired collateral development (grades of 0 or 1). Patients with poor collaterals were significantly more likely to have diabetes (<it>p </it>= 0.001), but less likely to have used statins (<it>p </it>= 0.083). FMD measurements were not significantly different among good and poor collateral groups (11.5 ± 5.6 vs. 10.4 ± 6.2% respectively, <it>p </it>= 0.214). Nitroglycerin mediated dilation was also similar (13.4 ± 5.9 vs. 12.8 ± 6.5%, <it>p </it>= 0.521).</p> <p>Conclusion</p> <p>No significant association was found between the extent of angiographically visible coronary collaterals and systemic endothelial function assessed by FMD of the brachial artery.</p
The Association Between Familial Risk and Brain Abnormalities Is Disease Specific: An ENIGMA-Relatives Study of Schizophrenia and Bipolar Disorder
Background: Schizophrenia and bipolar disorder share genetic liability, and some structural brain abnormalities are common to both conditions. First-degree relatives of patients with schizophrenia (FDRs-SZ) show similar brain abnormalities to patients, albeit with smaller effect sizes. Imaging findings in first-degree relatives of patients with bipolar disorder (FDRs-BD) have been inconsistent in the past, but recent studies report regionally greater volumes compared with control subjects. Methods: We performed a meta-analysis of global and subcortical brain measures of 6008 individuals (1228 FDRs-SZ, 852 FDRs-BD, 2246 control subjects, 1016 patients with schizophrenia, 666 patients with bipolar disorder) from 34 schizophrenia and/or bipolar disorder family cohorts with standardized methods. Analyses were repeated with a correction for intracranial volume (ICV) and for the presence of any psychopathology in the relatives and control subjects. Results: FDRs-BD had significantly larger ICV (d = +0.16, q <.05 corrected), whereas FDRs-SZ showed smaller thalamic volumes than control subjects (d = −0.12, q <.05 corrected). ICV explained the enlargements in the brain measures in FDRs-BD. In FDRs-SZ, after correction for ICV, total brain, cortical gray matter, cerebral white matter, cerebellar gray and white matter, and thalamus volumes were significantly smaller; the cortex was thinner (d < −0.09, q <.05 corrected); and third ventricle was larger (d = +0.15, q <.05 corrected). The findings were not explained by psychopathology in the relatives or control subjects. Conclusions: Despite shared genetic liability, FDRs-SZ and FDRs-BD show a differential pattern of structural brain abnormalities, specifically a divergent effect in ICV. This may imply that the neurodevelopmental trajectories leading to brain anomalies in schizophrenia or bipolar disorder are distinct
Static analysis of business artifact-centric operational models
Business Artifacts are the core entities used by businesses to record information pertinent to their operations. Business operational models are representations of the processing of business artifacts. Traditional process modeling approaches focus on the actions taken to achieve a certain goal (verb-centric). Business artifact-centric modeling starts by identifying what is acted upon (noun-centric), and constructs business operational models by identifying the tasks/actions that business actors execute to add business value. In this paper, we identify important classes of properties on artifact-centric operational models. In particular, we focus on persistence, uniqueness and arrival properties. To enable a static analysis of these properties, we propose a formal model for artifact-centric operational models. We show that the formal model guarantees persistence and uniqueness. We prove that, while checking an arrival property is undecidable in general, under a restricted version of the formalism, an arrival property can be checked in EXPTIME.
Information Infrastructures and the Future of Ecological Citizenship in the Anthropocene
In the last two decades, the concept of ecological citizenship has become a recurrent theme in both popular and academic discussions. Discussions around the prospects of, and limitations to, ecological citizenship have mostly focused on the idea of political agency and the civic responsibility of individuals in relation to their environments, with an emphasis on environmental justice and sustainability. However, the current scholarship has yet to adequately characterize its conceptual bases and empirical applications from an information perspective. Therefore, this paper provides an overview of citizenship studies and infrastructure studies for developing more nuanced understanding(s) of epistemological models for ecological citizenship in our networked world. Drawing on the literature on information infrastructure, this paper then proposes a conceptual framework to understand ecological citizenship as constituted both discursively and techno-materially through neoliberal, anthropocentric informational infrastructures
Online and minimum-cost ad hoc delegation in e-service composition
The paradigm of automated e-service composition through the integration of existing services promises a fast and efficient development of new services in cooperative business environments. Although the “why ” part of this paradigm is well understood, many key pieces are missing to utilize the available opportunities. Recently “e-service communities ” where service providers with similar interests can register their services are proposed towards realizing this goal. In these communities, requests for services posed by users can be processed by delegating them to already registered services, and orchestrating their executions. We use the service framework of the “Roman” model and further extend it to integrate activity processing costs into the “ad hoc ” delegation computation. We investigate the problem of efficient processing of service requests in service communities and develop polynomial time ad hoc delegation techniques guaranteeing optimality.
Specification and Verification of Artifact Behaviors in Business Process Models ⋆
Abstract. SOA has influenced business process modeling and management. Recent business process models have elevated data representation to the same level as control flows, for example, the artifact-centric business process models allow the life cycle properties of artifacts (data objects) to be specified and analyzed. In this paper, we develop a specification language ABSL based on computation tree logic for artifact life cycle behaviors (e.g., reachability). We show that given a business model and starting configuration, it can be decided if an ABSL sentence is satisfied when the domains are bounded, and if an ABSL-core (sublanguage of ABSL) sentence is satisfied when the domains are totally ordered but unbounded. We also show that if the starting configuration is not given, ABSL(-core) is still decidable if the number of artifacts is bounded with bounded (resp. unbounded but ordered) domains.
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