43 research outputs found
Gender employment discrimination : Greece and the United Kingdom
Get PDFPurpose: This study examines the factors affecting the labour market status of females in Greece and the UK respectively, and also attempts to explore what accounts for the differences in the employment status between males and females. In particular, the study assesses whether these differences can be explained by employees’ endowments or by discrimination in the labour market.
Methodology-Approach: Labour Force Survey (LFS) data are used to examine the impact of observable characteristics on female labour market participation,unemployment and self-employment through the use of logit models. An extension of
the Oaxaca-Blinder decomposition technique is used to estimate the gender employment discrimination gap.
Findings: Clear evidence of gender differences was found in both countries, although differences are substantially larger in the case of Greece. Evidence of female
employment discrimination was also found in both labour markets.
Originality/Value: The paper explores the factors affecting the labour market situation of females, and for the first time, assesses the level of gender employment
discrimination in Greece and the UK analysing the differences on the unemployment rates of males and females
Investigation of Vortex Induced Vibrations on Wind Turbine Towers
No full textVortex Induced Vibrations (VIV) is a well-known and explored topic. It is a quite complex phenomenon as it is part of different disciplines including fluid mechanics, structural mechanincs, vibrations and computational dynamics. It can be found in many engineering applications such as bridges, industrial chimneys, transmission lines, marine risers in petroleum production and in other hydrodynamics applications. Despite it is a well-known and widely explored topic, the modelling of vortex induced vibrations for engineering purposes still presents a lot of issues due to the complexity of the phenomena involved. These oscillations are of great interest for structural engineers, not only because of the large oscillation amplitude but also due to the long term cyclic loads which can cause significant fatigue damage to the wind turbine towers. In this thesis the phenomenon of VIV on wind turbine towers is examined. Before the commissioning of the towers in the offshore wind farms, there is a number of different load cases when these structures are susceptible to VIV. These cases are summarized in the following: (i) towers standing on the quay-side, (ii) on the vessel during their transportation offshore and (iii) as installed towers on the foundation (e.g. monopile or jacket) before the installation of the rotor-nacelle assembly (RNA). The main objective is to formulate a realistic model for the prediction of wind turbine towers response due to VIV. The tower geometry includes a tapered section at the top of the structure complicating the phenomenon. The thesis approach starts with a literature study and continues with investigating the different approaches proposed from the Standards (e.g. Eurocode) and the researchers over the years. Investigation of the theoretical background of each analytical model, sensitivity analysis of the main influencing parameters and comparison of the computed vibration amplitudes contributed to the identification of advantages and limitations of these approaches. Consequently, knowledge gained from this research and data extracted from forced oscillation experiments performed in a wind tunnel contributed to the development of a more accurate, reliable and realistic model for the prediction of the tower response due to VIV. The recommended design procedure models the fluid structure interaction through a negative aerodynamic damping and takes into account the tapered section of the tower, the effect of turbulence intensity and the shear exponent factor of the wind. Finally, fatigue analysis of the wind turbine towers is performed in order to assess the effect of VIV on the lifetime of these structures. Concluding, through the literature study and the review of the approaches proposed by the design codes and various researchers, a design procedure for the prediction of the tower response over a range of wind velocities is developed. Simplifications of existing methodologies proposed by the Standards limit their accuracy for design purposes. Finally, further experimental investigations and CFD simulations regarding the effect of group arrangements of the towers and the effectiveness of suppression measures are proposed for future research.<br/
Educational interventions need evidence too. Commentary: a crisis in comparative psychology: where have all the undergraduates gone?
No full textAbramson laments that there is a crisis in comparative psychology, measuring success by recruitment to undergraduate courses. By employing such a narrow perspective on how to measure the success of a field, the article offers a narrow viewpoint on the issue and, as such, I am concerned that the solutions it offers may be ineffective. I urge academics to look outwards and work with other groups, such as the students themselves. If we believe our field is ‘in crisis’, isolating ourselves is not a solution.Peer reviewe
Intestinal host response to SARS-CoV-2 infection and COVID-19 outcomes in patients with gastrointestinal symptoms
No full textBackground & aims: Given that gastrointestinal (GI) symptoms are a prominent extrapulmonary manifestation of COVID-19, we investigated intestinal infection with SARS-CoV-2, its effect on pathogenesis, and clinical significance. Methods: Human intestinal biopsy tissues were obtained from patients with COVID-19 (n = 19) and uninfected control individuals (n = 10) for microscopic examination, cytometry by time of flight analyses, and RNA sequencing. Additionally, disease severity and mortality were examined in patients with and without GI symptoms in 2 large, independent cohorts of hospitalized patients in the United States (N = 634) and Europe (N = 287) using multivariate logistic regressions. Results: COVID-19 case patients and control individuals in the biopsy cohort were comparable for age, sex, rates of hospitalization, and relevant comorbid conditions. SARS-CoV-2 was detected in small intestinal epithelial cells by immunofluorescence staining or electron microscopy in 15 of 17 patients studied. High-dimensional analyses of GI tissues showed low levels of inflammation, including down-regulation of key inflammatory genes including IFNG, CXCL8, CXCL2, and IL1B and reduced frequencies of proinflammatory dendritic cells compared with control individuals. Consistent with these findings, we found a significant reduction in disease severity and mortality in patients presenting with GI symptoms that was independent of sex, age, and comorbid illnesses and despite similar nasopharyngeal SARS-CoV-2 viral loads. Furthermore, there was reduced levels of key inflammatory proteins in circulation in patients with GI symptoms. Conclusions: These data highlight the absence of a proinflammatory response in the GI tract despite detection of SARS-CoV-2. In parallel, reduced mortality in patients with COVID-19 presenting with GI symptoms was observed. A potential role of the GI tract in attenuating SARS-CoV-2-associated inflammation needs to be further examined
A highly adaptive microbiome-based association test for survival traits
No full textAbstract Background There has been increasing interest in discovering microbial taxa that are associated with human health or disease, gathering momentum through the advances in next-generation sequencing technologies. Investigators have also increasingly employed prospective study designs to survey survival (i.e., time-to-event) outcomes, but current item-by-item statistical methods have limitations due to the unknown true association pattern. Here, we propose a new adaptive microbiome-based association test for survival outcomes, namely, optimal microbiome-based survival analysis (OMiSA). OMiSA approximates to the most powerful association test in two domains: 1) microbiome-based survival analysis using linear and non-linear bases of OTUs (MiSALN) which weighs rare, mid-abundant, and abundant OTUs, respectively, and 2) microbiome regression-based kernel association test for survival traits (MiRKAT-S) which incorporates different distance metrics (e.g., unique fraction (UniFrac) distance and Bray-Curtis dissimilarity), respectively. Results We illustrate that OMiSA powerfully discovers microbial taxa whether their underlying associated lineages are rare or abundant and phylogenetically related or not. OMiSA is a semi-parametric method based on a variance-component score test and a re-sampling method; hence, it is free from any distributional assumption on the effect of microbial composition and advantageous to robustly control type I error rates. Our extensive simulations demonstrate the highly robust performance of OMiSA. We also present the use of OMiSA with real data applications. Conclusions OMiSA is attractive in practice as the true association pattern is unpredictable in advance and, for survival outcomes, no adaptive microbiome-based association test is currently available
‐Promoted Coupling of Ketones and Activated Acyl Donors via Soft Enolization: A Practical Synthesis of 1,3‐Diketones.
No full textAdditional file 6: of A highly adaptive microbiome-based association test for survival traits
No full textFigure S5. Power estimates for the individual and adaptive tests. The censoring scheme, Ci ~ Unif(0,5), and the same effect directions, where βj ∈ Λ is a vector of the elements sampled from Unif(0,1) (blue), Unif(0,2) (yellow), or Unif(0,3) (red), for a small sample size (n = 50) were surveyed. KU, K0.5, KW, and KBC, indicates the use of unweighted UniFrac, generalized UniFrac with ϴ = 0.5, weighted UniFrac, and the Bray-Curtis dissimilarity kernels, respectively, for MiRKAT-S [24]. (A: 10 most abundant OTUs are associated. B: 10 random OTUs are associated. C: 10 least abundant OTUs are associated. D: OTUs in a chosen cluster are associated.). (PDF 9 kb
Additional file 11: of A highly adaptive microbiome-based association test for survival traits
No full textFigure S10. Power estimates for individual MiRKAT-S tests through different software facilities, OMiSA and MiRKATS (via analytic p-value calculation). The censoring scheme, Ci ~ Unif(0,5), and the mixed effect directions, where βj ∈ Λ is a vector of the elements sampled from Unif(− 1,1) (blue), Unif(− 2,2) (yellow), or Unif(− 3,3) (red), for a large sample size (n = 100) were surveyed. KU, K0.5, KW, and KBC, indicates the use of unweighted UniFrac, generalized UniFrac with ϴ = 0.5, weighted UniFrac, and the Bray-Curtis dissimilarity kernels, respectively. (PDF 6 kb
Additional file 10: of A highly adaptive microbiome-based association test for survival traits
No full textFigure S9. Power estimates for individual MiRKAT-S tests through different software facilities, OMiSA and MiRKATS (via analytic p-value calculation). The censoring scheme, Ci ~ Unif(0,5), and the same effect directions, where βj ∈ Λ is a vector of the elements sampled from Unif(0,1) (blue), Unif(0,2) (yellow), or Unif(0,3) (red), for a large sample size (n = 100) were surveyed. KU, K0.5, KW, and KBC, indicates the use of unweighted UniFrac, generalized UniFrac with ϴ = 0.5, weighted UniFrac, and the Bray-Curtis dissimilarity kernels, respectively. (PDF 6 kb
