293 research outputs found

    Private-label use and store loyalty

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    The authors develop an econometric model of the relationship between a household’s private-label (PL) share and its behavioral store loyalty. The model includes major drivers of these two behaviors and controls for simultaneity and nonlinearity in the relationship between them. The model is estimated with a unique data set that combinescomplete purchase records of a panel of Dutch households with demographic and psychographic data. The authorsestimate the model for two retail chains in the Netherlands the leading service chain with a well-differentiatedhigh-share PL and the leading value chain with a lower-share PL. They find that PL share significantly affects all three measures of behavioral loyalty in the study: share of wallet, share of items purchased, andshare of shopping trips. In addition, behavioral loyalty has a significant effect on PL share. For the service chain, the authors find that both effects are in the form of an inverted U. For the value chain, the effects are positive and nonlinear, but they do not exhibit nonmonotonicity, because PL share has not yet reached high enough levels. The managerial implications of this research are important. Retailers can reap the benefits of a virtuous cycle; greater PL share increases share of wallet, and greater share of wallet increases PL share. However, this virtuous cycle operates only to a point because heavy PL buyers tend to be loyal to price savings and PLs in general, not to the PL of any particular chain.pre-prin

    Minimally Invasive Mitral Valve Surgery III: Training and Robotic-Assisted Approaches.

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    Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program

    Minimally Invasive Mitral Valve Surgery I: Patient Selection, Evaluation, and Planning.

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    Widespread adoption of minimally invasive mitral valve repair and replacement may be fostered by practice consensus and standardization. This expert opinion, first of a 3-part series, outlines current best practices in patient evaluation and selection for minimally invasive mitral valve procedures, and discusses preoperative planning for cannulation and myocardial protection

    Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management.

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    Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery

    Designing comparative effectiveness trials of surgical ablation for atrial fibrillation: Experience of the Cardiothoracic Surgical Trials Network

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    ObjectiveSince the introduction of the cut-and-sew Cox maze procedure for atrial fibrillation, there has been substantial innovation in techniques for ablation. Use of alternative energy sources for ablation simplified the procedure and has resulted in dramatic increase in the number of patients with atrial fibrillation treated by surgical ablation. Despite its increasingly widespread adoption, there is lack of rigorous clinical evidence to establish this procedure as an effective clinical therapy.MethodsThis article describes a comparative effectiveness randomized trial, supported by the Cardiothoracic Surgical Clinical Trials Network, of surgical ablation with left atrial appendage closure versus left atrial appendage closure alone in patients with persistent and long-standing persistent atrial fibrillation undergoing mitral valve surgery. Nested within this trial is a further randomized comparison of 2 different lesions sets: pulmonary vein isolation and the full maze lesion set.ResultsThis article addresses trial design challenges, including how best to characterize the target population, operationalize freedom from atrial fibrillation as a primary end point, account for the impact of antiarrhythmic drugs, and measure and analyze secondary end points, such as postoperative atrial fibrillation load.ConclusionsThis article concludes by discussing how insights that emerge from this trial may affect surgical practice and guide future research in this area

    Tricuspid Valve Academic Research Consortium Definitions for Tricuspid Regurgitation and Trial Endpoints.

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    Interest in the pathophysiology, etiology, management, and outcomes of patients with tricuspid regurgitation (TR) has grown in the wake of multiple natural history studies showing progressively worse outcomes associated with increasing TR severity, even after adjusting for multiple comorbidities. Historically, isolated tricuspid valve surgery has been associated with high in-hospital mortality rates, leading to the development of transcatheter treatment options. The aim of this first Tricuspid Valve Academic Research Consortium document is to standardize definitions of disease etiology and severity, as well as endpoints for trials that aim to address the gaps in our knowledge related to identification and management of patients with TR. Standardizing endpoints for trials should provide consistency and enable meaningful comparisons between clinical trials. A second Tricuspid Valve Academic Research Consortium document will focus on further defining trial endpoints and will discuss trial design options

    Tricuspid Valve Academic Research Consortium Definitions for Tricuspid Regurgitation and Trial Endpoints.

    Get PDF
    Interest in the pathophysiology, etiology, management, and outcomes of patients with tricuspid regurgitation (TR) has grown in the wake of multiple natural history studies showing progressively worse outcomes associated with increasing TR severity, even after adjusting for multiple comorbidities. Historically, isolated tricuspid valve surgery has been associated with high in-hospital mortality rates, leading to the development of transcatheter treatment options. The aim of this first Tricuspid Valve Academic Research Consortium document is to standardize definitions of disease etiology and severity, as well as endpoints for trials that aim to address the gaps in our knowledge related to identification and management of patients with TR. Standardizing endpoints for trials should provide consistency and enable meaningful comparisons between clinical trials. A second Tricuspid Valve Academic Research Consortium document will focus on further defining trial endpoints and will discuss trial design options

    Exogenous 17-β estradiol administration blunts progression of established angiotensin II-induced abdominal aortic aneurysms in female ovariectomized mice

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    BACKGROUND: Abdominal aortic aneurysms (AAAs) occur predominately in males. However, AAAs in females have rapid growth rates and rupture at smaller sizes. Mechanisms contributing to AAA progression in females are undefined. We defined effects of ovariectomy, with and without 17-β estradiol (E2), on progression of established angiotensin II (AngII)-induced AAAs in female mice. METHODS: We used neonatal testosterone exposures at 1 day of age to promote susceptibility to AngII-induced AAAs in adult female Ldlr(−/−) mice. Females were infused with AngII for 28 days to induce AAAs, and then stratified into groups that were sham, ovariectomized (Ovx, vehicle), or Ovx with E2 administration for 2 months of continued AngII infusions. Aortic lumen diameters were quantified by ultrasound and analyzed by linear mixed model, and maximal AAA diameters were analyzed by one-way ANOVA. Atherosclerosis was quantified en face in the aortic arch. AAA tissue sections were analyzed for cellular composition. We quantified effects of E2 on abdominal aortic smooth muscle cell (SMC) growth, α-actin and transforming growth factor-beta (TGF-β) production, and wound healing. RESULTS: Serum E2 concentrations were increased significantly by E2. Aortic lumen diameters increased over time in sham-operated and Ovx (vehicle) females, but not in Ovx females administered E2. At day 70, E2 administration decreased significantly aortic lumen diameters compared to Ovx vehicle and sham-operated females. Compared to Ovx females (vehicle), maximal AAA diameters were reduced significantly by E2. AAA tissue sections from Ovx females administered E2 exhibited significant increases in α-actin and decreases in neutrophils compared to Ovx females administered vehicle. In abdominal aortic SMCs, E2 resulted in a concentration-dependent increase in α-actin, elevated TGF-β, and more rapid wound healing. E2 administration to Ovx females also significantly reduced atherosclerotic lesions compared to sham-operated females. This effect was accompanied by significant reductions in serum cholesterol concentrations. CONCLUSIONS: E2 administration to Ovx females abolished progressive growth and decreased severity of AngII-induced AAAs. These effects were accompanied by increased SMC α-actin, elevated TGF-β, and reduced neutrophils. Similarly, E2 administration reduced AngII-induced atherosclerosis. These results suggest that loss of E2 in post-menopausal females may contribute to progressive growth of AAAs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13293-015-0030-1) contains supplementary material, which is available to authorized users

    Towards modeling the retailer as a brand: A social construction of the grocery store from the customer standpoint

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    As a highly customer-sensitive business, retailing is one of the most socially active industries. Nevertheless, when addressing retailers as brands, the retailing literature has failed to account for their unique social orientation, exposing a gap in the literature. This paper utilizes the sociological view of brands to socially construct a conceptual retail brand model from the customer standpoint. An ethnographic study of grocery retailing revealed that the store has, metaphorically, a tree-shaped culture, which can organically model the interplay between building the retailer brand as a culture and the phases constituting the social-self concept

    Generation of human vascular smooth muscle subtypes provides insight into embryological origin-dependent disease susceptibility.

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    Heterogeneity of embryological origins is a hallmark of vascular smooth muscle cells (SMCs) and may influence the development of vascular disease. Differentiation of human pluripotent stem cells (hPSCs) into developmental origin-specific SMC subtypes remains elusive. Here we describe a chemically defined protocol in which hPSCs were initially induced to form neuroectoderm, lateral plate mesoderm or paraxial mesoderm. These intermediate populations were further differentiated toward SMCs (>80% MYH11(+) and ACTA2(+)), which displayed contractile ability in response to vasoconstrictors and invested perivascular regions in vivo. Derived SMC subtypes recapitulated the unique proliferative and secretory responses to cytokines previously documented in studies using aortic SMCs of distinct origins. Notably, this system predicted increased extracellular matrix degradation by SMCs derived from lateral plate mesoderm, which was confirmed using rat aortic SMCs from corresponding origins. This differentiation approach will have broad applications in modeling origin-dependent disease susceptibility and in developing bioengineered vascular grafts for regenerative medicine
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