Birefringence of interferential mirrors at normal incidence Experimental and computational study

In this paper we present a review of the existing data on interferential mirror birefringence. We also report new measurements of two sets of mirrors that confirm that mirror phase retardation per reflection decreases when mirror reflectivity increases. We finally developed a computational code to calculate the expected phase retardation per reflection as a function of the total number of layers constituting the mirror. Different cases have been studied and we have compared computational results with the trend of the experimental data. Our study indicates that the origin of the mirror intrinsic birefringence can be ascribed to the reflecting layers close to the substrate.Comment: To be published in Applied Physics

The charismatic leadership of the ECB presidency:A language-based analysis

There is little doubt that the European Central Bank (ECB), and in particular its presidency, has taken the lead in tackling the euro crisis. But can this leadership be also characterised as charismatic? This article answers the question by focusing on language – a key component as well as a reliable indicator of charisma. By means of a software‐assisted content analysis of the entire corpus of ECB presidential speeches, it is found that the crisis has indeed led to the emergence of the Bank's presidency as a charismatic euro leader. This in turn confirms the recent politicisation of the ECB, but at the same time might be seen as mitigating the problems related to the Bank's democratic deficit, to the extent that charisma can be seen, from a Weberian standpoint, as an alternative source of political legitimacy

Structural basis for type VI secreted peptidoglycan DL-endopeptidase function, specificity and neutralization in <em>Serratia marcescens</em>

Some Gram-negative bacteria target their competitors by exploiting the type VI secretion system to extrude toxic effector proteins. To prevent self-harm, these bacteria also produce highly specific immunity proteins that neutralize these antagonistic effectors. Here, the peptidoglycan endopeptidase specificity of two type VI secretion-system-associated effectors from Serratia marcescens is characterized. These small secreted proteins, Ssp1 and Ssp2, cleave between γ-d-glutamic acid and l-meso-diaminopimelic acid with different specificities. Ssp2 degrades the acceptor part of cross-linked tetratetrapeptides. Ssp1 displays greater promiscuity and cleaves monomeric tripeptides, tetrapeptides and pentapeptides and dimeric tetratetra and tetrapenta muropeptides on both the acceptor and donor strands. Functional assays confirm the identity of a catalytic cysteine in these endopeptidases and crystal structures provide information on the structure–activity relationships of Ssp1 and, by comparison, of related effectors. Functional assays also reveal that neutralization of these effectors by their cognate immunity proteins, which are called resistance-associated proteins (Raps), contributes an essential role to cell fitness. The structures of two immunity proteins, Rap1a and Rap2a, responsible for the neutralization of Ssp1 and Ssp2-like endopeptidases, respectively, revealed two distinct folds, with that of Rap1a not having previously been observed. The structure of the Ssp1–Rap1a complex revealed a tightly bound heteromeric assembly with two effector molecules flanking a Rap1a dimer. A highly effective steric block of the Ssp1 active site forms the basis of effector neutralization. Comparisons with Ssp2–Rap2a orthologues suggest that the specificity of these immunity proteins for neutralizing effectors is fold-dependent and that in cases where the fold is conserved sequence differences contribute to the specificity of effector–immunity protein interactions

The European Union in the 21st century: Perspectives from the Lisbon Treaty. CEPS Paperbacks. December 2009

The new Treaty of Lisbon brings important changes to the European construction, including a significant expansion of common policies decided by the Community method, a stable President for the European Council, a strengthened framework for external policies, more transparent and effective decision-making and strict safeguards of subsidiarity. This collection of essays edited by Stefano Micossi and Gian Luigi Tosato, analyse the changing equilibria in common policies, institutional settings and mechanisms of legitimisation of the European Union and sketch out possible scenarios for the 21st century

Minimal models of glucose disappearance: lessons from the labelled IVGTT.

In this paper the domain of validity of the unlabelled and labelled minimal models of glucose disappearance is studied. Labelled intravenous glucose tolerance tests were performed in six normal subjects using 3-3H-glucose as the tracer. Insulin and unlabelled glucose data were analysed with the minimal model of glucose disappearance. The model provides estimates of glucose effectiveness (SG) and insulin sensitivity (SI) which measure the effects of glucose per se and insulin on both glucose production and disposal. Insulin and labelled glucose data were analysed with the labelled minimal model of tracer disappearance. Estimates of glucose effectiveness (SG*) and insulin sensitivity (SI*) which reflect disposal processes only were calculated. The results of the two minimal models suggest two areas of model error. Firstly, the relationships between labelled and unlabelled parameters contradict the theoretical expectation. Secondly, the time-course of hepatic glucose production is unrealistic. Possible sources of these inconsistencies are an inadequate description of the glucose and/or insulin effect upon hepatic glucose production, and the assumption that glucose kinetics are monocompartmental. The monocompartmental description of glucose kinetics may affect both model parameters and hepatic glucose production and this leads to a critical reexamination of the previously published validation studies in which the minimal model metabolic indices have been compared with the analogous indices measured during glucose clamp studies

Gluten-free diet: a new strategy for management of painful endometriosis related symptoms?

Pelvic pain affects 4% to 39% of women and accounts for 10-40% of all outpatient gynecologic visits. The etiology of painful endometriosis-related has not been fully delineated. No studies have been published concerning gluten-free diet administered to achieved relief of painful symptoms endometriosis-related. The aim of this retrospective study was to evaluate the effectiveness for the outcomes of endometriosis-related pain and quality of life of gluten-free diet in a follow-up of 12 months in patients with chronic pelvic pain endometriosis-related

Peritoneal and subcutaneous absorption of insulin in type I diabetic subjects

We and others have shown that in type I diabetes, ip insulin delivery results in lower free insulin levels than sc delivery. The aim of this study was to compare the rate of appearance of insulin in the peripheral circulation during ip and sc insulin administration in type I diabetes, in steady state and nonsteady state. To do this, we determined free insulin levels during ip or sc infusion as well as the impulse response of the insulin system after iv injection of a 6-nmol bolus of insulin. Twelve hours after a constant basal insulin infusion (5.5 +/- 1.4 nmol/h) was started, five C-peptide-negative type I diabetic subjects showed a lower systemic rate of appearance of insulin (expressed as a percentage of the administered dose) with ip than sc administration (27 +/- 6% vs. 40 +/- 10%; P < 0.001). In nonsteady state, when the infusion rate was increased from basal to 15 nmol/h (0-150 min) and subsequently to 42 nmol/h (150-300 min), the percent increase in insulin's systemic rate of appearance was higher with ip than sc infusion (P < 0.05 from 60-150 min; P < 0.01 from 150-300 min), indicating faster absorption. Thus, we conclude that insulin is more rapidly absorbed from the peritoneal cavity than from sc tissue. However, with ip administration, a sizable amount of insulin, once absorbed, is extracted before reaching the peripheral circulation, most likely by the liver. This is indirect evidence that ip insulin delivery results in a portal-peripheral insulin gradient in humans