1,720,967 research outputs found

    Quantitative easing, financial risk, and portfolio diversification

    No full text
    We assess the extent to which the aforementioned changed monetary conditions have affected the relationship between financial markets and some leading macro-finance indicators. In the first part, we thus examine the financialmarkets dynamics before and after February 2006. We find evidence supporting the view that the macro-finance foundation of market movements has changed substantially in the Bernanke period. If real interest rates could explain markets’ performance in the second part of the Greenspan tenure, the stochastic discount factor (SDF) seems to be the only factor capable of explaining financial markets movements after 2006. In the second part, we relate our findings to the extraordinary growth of money supply determined by the Federal Reserve’s choice of expanding its balance sheet by purchasing long-term Treasury securities. In addition, rather than focusing exclusively on money supply, we explore the role of the risk premium that seems to lie beneath the different outcome characterizing the Bernanke sample. Gagnon et al. (2011), in fact, find that the flattening of the yield curve is mostly due to declining term premia. Our empirical findings are in line with the achievements of modern macro-finance theory, according to which asset pricing is explained by time-varying risk aversion and the cyclical movements of term premia (Campbell and Cochrane, 1999; Brandt and Wang, 2003; Wachter, 2006; Li, 2007; Mele, 2007). In particular, we argue that risk premia are related to changes in both unemployment and risk aversion, finding evidence that the weak discounting process implied by high levels of risk aversion can explain the cyclical behavior of assets prices

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

    Full text link
    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

    Full text link
    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Fate of primary determinate and indeterminate target vessel endoleaks after fenestrated-branched endovascular aortic repair

    Full text link
    Objective: The aim of this study was to investigate the outcomes of primary determinate and indeterminate target vessel endoleaks (TVELs) after fenestrated-branched endovascular aortic repair (F-BEVAR). Methods: We conducted a single-center retrospective study (2014-2023) on F-BEVAR for thoracoabdominal (TAAAs) or pararenal aortic aneurysms (PRAAs). TVELs were classified as "primary" if present at the first postoperative computed tomography angiogram. Endoleaks were defined "determinate" (dELs) if the cause (type Ic or IIIc) and implicated target vessel were identifiable and "indeterminate" (iELs) if contrast enhancement was detectable at the level of fenestrations/branches without any evident source. Endoleaks involving multiple inflows (type II and target vessels) were defined as "complex" (cELs). Endpoints were endoleak spontaneous resolution, 1-year aneurysm sac failure to regress (>5 mm diameter decrease), and 4-year endoleak-related secondary interventions. Kaplan-Meier estimates and Cox regression were used for the analysis. Results: There were 142 patients with JRAAs/PRAAs (n = 85; 60%) or TAAAs (n = 57; 40%), with 513 target arteries incorporated through a fenestration (n = 294; 57%) or directional branch (n = 219; 43%). Fifty-nine primary TVELs (12%) were identified in 35 patients (25%), a dEL in 20 patients (14%) and iEL in 15 (11%); 22 (15%) had a determinate or indeterminate cEL. Overall spontaneous resolution rate was 75% (95% confidence interval [CI], 51%-87%) at 4 years. cELs (odds ratio [OR], 5.00; 95% CI, 1.10-49.4; P 6 months, and persistent forms were associated with sac failure to regress at 1 year (OR, 1.72; 95% CI, 1.03-12.59; P = .040). Overall freedom from endoleak-related reinterventions was 85% (95% CI, 79%-92%) at 4 years, 92% (95% CI, 87%-97%) for those without primary TVELs and 62% (95% CI, 46%-84%) for those with any primary TVEL (P < .001). In particular, cELs (hazard ratio, 1.94; 95% CI, 1.4-18.81; P = .020) were associated with an increased need for reintervention. In case a secondary intervention was needed, iEL or cEL had an increased risk for multiple secondary procedures (hazard ratio, 2.67; 95% CI, 1.22-10.34; P = .034). Conclusions: Primary TVELs are frequent after F-BEVAR, and a clear characterization of the endoleak source by computed tomography angiogram is not possible in 40% of patients. Most primary TVELs spontaneously resolve, but during follow-up, patients with any primary TVEL experience a worsened freedom from endoleak-related reinterventions that is mostly driven by persistence of cELs and post-BEVAR iELs. Multiple secondary procedures may be required in case of iELs or cELs

    Dispelling the Myths Behind First-author Citation Counts

    Full text link
    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

    No full text
    Nao informado

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
    corecore