Bias extension test for pantographic sheets: numerical simulations based on second gradient shear energies

We consider a bi-dimensional sheet consisting of two orthogonal families of inextensible fibres. Using the representation due to Rivlin and Pipkin for admissible placements, i.e. placements preserving the lengths of the inextensible fibres, we numerically simulate a standard bias extension test on the sheet, solving a non-linear constrained optimization problem. Several first and second gradient deformation energy models are considered, depending on the shear angle between the fibres and on its gradient, and the results obtained are compared. The proposed numerical simulations will be helpful in designing a systematic experimental campaign aimed at characterizing the internal energy for physical realizations of the ideal pantographic structure presented in this paper

Corporate governance codes: a review and research agenda

Manuscript Type: Review Research Question/Issue: This study reviews previous country-level and firm-level studies on corporate governance codes up to 2014 in order to highlight recent trends and indicate future avenues of research. Research Findings/Results: Our data show that research on codes increases over time consistently with the diffusion and the relevance of the empirical phenomenon. Despite previous studies have substantially enriched our knowledge of the antecedents and the consequences of governance codes, our study shows there are still several opportunities for making significant contributions in this area. Theoretical Implications: Agency theory is the dominant theoretical framework, although other theoretical perspectives (especially the institutional one) are increasingly adopted. Future studies should be aimed at widening and combining various theoretical lenses so as to develop new interpretations and a better understanding of governance codes. Practical Implications: Legislators and policy makers should continue to develop and update the recommendations of national governance codes in order to address the potential failures of corporate governance mechanisms in place

an innovative algorithm to estimate risk optimum path for unmanned aerial vehicles in urban environments

Abstract The diffusion of the Unmanned Aerial Vehicles (UAVs) requires a suitable approach to define safe flight operations. In this paper, an innovative algorithm able to quantify the risk to the population and to search for the minimum risk path is proposed. The method has two main phases: in the former, a risk-map is generated quantifying the risk of a specific area, in the latter, a path planning algorithm seeks for the optimal path minimizing the risk. The risk-map is generated with a risk assessment method combining layers related to the population density, the sheltering factor, no-fly zones and obstacles. The risk-aware path planning is based on the well-known Optimal Rapidly-exploring Random Tree, with the minimization of the risk cost with respect to the flight time. Simulation results corroborate the validity of the approach

Biomarkers, Inflammation, and Bipolar Disorder: Association Between the Improvement of Bipolar Disorder Severity and the Improvement in C-Reactive Protein Levels After 7 Days of Inpatient Treatment

Introduction: Compared to the general population, people with severe mental illness (SMI) have a poorer health status and a higher mortality rate, with a 10-20-year reduction in life expectancy. Excess mortality and morbidity in SMI have been explained by intertwined components. Inflammatory processes could increase the morbidity and mortality risk in patients with bipolar disorder (BD) because of a bidirectional interaction between BD and conditions related to inflammation. This pilot study aimed to evaluate the relationship between C-Reactive-Protein (CRP) and bipolar disorder severity.Methods: A retrospective observational study was conducted on 61 hospitalized patients with bipolar disorder. CRP was measured at admission to inpatient treatment (T0) and after seven days from the admission (T1). Clinical Global Impression for Depression, Mania and Overall Bipolar Illness were recorded at T0 and T1. Comparisons among the recorded CRP values were determined through the paired t-test. Correlations between CRP and CGI scores were determined through Spearman's correlation coefficient at T0 and T1.Results: A statistically significant decrease in CRP values was observed after 7 days of hospitalization (p < 0.001) and positive significant correlations emerged between CRP and CGI scores at T0 and T1.Conclusion: Patients admitted to the inpatient unit reported a statistically significant decrease of CRP values during the first 7 days of treatment. Although the direction of the relationship between BP severity and inflammation status continues to remain unclear, this study showed a relationship between the improvement of bipolar disease symptoms and the improvement of the inflammatory marker CRP

Yin Yang 1 extends the Myc-related transcription factors network in embryonic stem cells

The Yin Yang 1 (YY1) transcription factor is a master regulator of development, essential for early embryogenesis and adult tissues formation. YY1 is the mammalian orthologue of Pleiohomeotic, one of the transcription factors that binds Polycomb DNA response elements in Drosophila melanogaster and mediates Polycomb group proteins (PcG) recruitment to DNA. Despite several publications pointing at YY1 having a similar role in mammalians, others showed features of YY1 that are not compatible with PcG functions. Here, we show that, in mouse Embryonic Stem (ES) cells, YY1 has genome-wide PcG-independent activities while it is still stably associated with the INO80 chromatin-remodeling complex, as well as with novel RNA helicase activities. YY1 binds chromatin in close proximity of the transcription start site of highly expressed genes. Loss of YY1 functions preferentially led to a down-regulation of target genes expression, as well as to an up-regulation of several small non-coding RNAs, suggesting a role for YY1 in regulating small RNA biogenesis. Finally, we found that YY1 is a novel player of Myc-related transcription factors and that its coordinated binding at promoters potentiates gene expression, proposing YY1 as an active component of the Myc transcription network that links ES to cancer cells

On the fatigue improvement of railways superstructure components due to cold expansion – Part I: Experimental analysis

The fatigue strength improvement of materials and structures has always been the subject of studies, as a consequence of the rapid development of technologies and strictive safety requirements. In the railway field the fatigue resistance problem is thoroughly studied due to high transportation safety standard. Fatigue cracking is a major issue, in particular at rail-end-bolt holes. Cold Expansion is a common technique to induce beneficial residual compressive stresses around the holes, with the aim to improve the fatigue life of the rail. This paper is the first of a two part-series dealing with the study of the residual stress-strain field induced by the cold expansion process around rail-end-bolt holes. In Part I of this series, a contribution to better understanding the whole strain field distribution arising around rail-end-bolt holes during and after cold expansion is presented. Strains were experimentally measured using both electrical strain gauges and 2D-Digital Image Correlation. Contrary to common literature, strain-time history during the entire cold expansion process was investigated, in order to capture the highly non-linear elasto-plastic response of the material; the results of this study has been used in Part II of this series for the validation of the finite element model described there. The cold expansion process was applied to three rail holes, having equal nominal diameter. At first, the experimental results concerning each expanded hole are analysed. Then, all the results are compared, in order to evaluate the repeatability: - of the measurements; - of the Cold Expansion process; - of the adopted experimental technique, and, above all, to extrapolate the distribution of the hoop and radial residual strains as a function of the distance from the hole edge. At the end, results obtained by strain gauges and 2D-Digital Image Correlation are compared: a good agreement is found on the central flat surface of the rail web, which guarantees the availability of a robust and valuable highly non-linear reference result that has been used for the validation of the finite element model presented in Part II of this series

Low-dose pulse cyclophosphamide in interstitial lung disease associated with systemic sclerosis (SSc-ILD): efficacy of maintenance immunosuppression in responders and non-responders

To investigate the long-term disease course of patients with recently deteriorated systemic sclerosis (SSC)-interstitial lung disease (ILD) undergoing continuous immunosuppressive treatment with cyclophosphamide (CYC) as induction therapy