Effect of the Gribov horizon on the Polyakov loop and vice versa

We consider finite temperature SU(2) gauge theory in the continuum formulation, which necessitates the choice of a gauge fixing. Choosing the Landau gauge, the existing gauge copies are taken into account by means of the Gribov-Zwanziger (GZ) quantization scheme, which entails the introduction of a dynamical mass scale (Gribov mass) directly influencing the Green functions of the theory. Here, we determine simultaneously the Polyakov loop (vacuum expectation value) and Gribov mass in terms of temperature, by minimizing the vacuum energy w.r.t. the Polyakov loop parameter and solving the Gribov gap equation. Inspired by the Casimir energy-style of computation, we illustrate the usage of Zeta function regularization in finite temperature calculations. Our main result is that the Gribov mass directly feels the deconfinement transition, visible from a cusp occurring at the same temperature where the Polyakov loop becomes nonzero. In this exploratory work we mainly restrict ourselves to the original Gribov-Zwanziger quantization procedure in order to illustrate the approach and the potential direct link between the vacuum structure of the theory (dynamical mass scales) and (de)confinement. We also present a first look at the critical temperature obtained from the Refined Gribov-Zwanziger approach. Finally, a particular problem for the pressure at low temperatures is reported.Comment: 19 pages, 8 .pdf figures. v2: extended section 3 + extra references; version accepted for publication in EPJ

Complete design and optimization of multicomponent separation processes: the case study of the quaternary separation of nadolol stereoisomers

The direct chromatographic resolution of enantiomers using chiral stationary phases (CSPs) is actually a very well established separation technique. Several reasons were responsible for the growing success of this technique. The continuous technical development of new chiral stationary phases (CSPs) combined with their commercial availability has been, probably, the most relevant leverage issue. Chiral liquid chromatography is based on different mutual interactions between the molecules that elute with the liquid (solvent and solutes) and the molecules that are present in the stationary phase. Therefore, optimization of a chiral separation is based on the selection of a proper combination between a CSP and a mobile phase (solvent) composition by promoting, in a favourable way, all possible mutual interactions. The optimization will be a much more challenging task if we are leading not with a traditional binary racemic mixture separation problem but if we are interested in the separation of a quaternary chiral mixture. The complexity degree will be significantly increased if we consider a preparative separation, using a technique such as the simulated moving bed technology, were high feed concentrations are normally used in order to improve the process performance. In these situations, the wanted high concentrations of the different chiral solutes inside the chromatographic columns will enhance significantly the mutual competition between solutes for adsorption with the stationary phase. From a preparative point of view, and when considering the choice of the mobile phase (“solvent”) composition, a high selectivity of the enantiomers should not be the only goal to be aimed, as it is frequently the case at analytical scale. Besides the choice of a CSP with high loading capacity, a high solubility of the solutes in the solvent and low retention times should also be taken into account, in order to improve the preparative process performance, as it was extensively explained for the separation of chiral non-steroidal anti-inflammatory drugs1-4 . Nadolol (1-(tert-butyamino)-3-[(5,6,7,8-tetrahydro-cis-6,7-dihydroxy-1-naphthyl)oxy]-2-propanol) is a non-selective beta-adrenergic antagonist pharmaceutical drug. This class of pharmaceutical drugs is prescribed, mainly, to treat arrhythmias, angina pectoris, hypertension, migraine disorders and for tremor. Today, and in spite of the more and more restricted international legislation towards the commercialization of pharmaceutical drugs based on active principles that are made of single enantiomers, nadolol is still only commercially available as an equal mixture of four stereoisomers. This is even more serious due to the considerable evidence, recently made both by the academic community and pharmaceutical industry, that it is important to characterize the single stereochemical components when describing the pharmacodynamics and pharmacokinetics of a racemic drug. The separation of nadolol stereoisomers on CHIRALPAK® AD at both analytical and preparative scales was recently reportedby Ribeiro et al5. However, nowadays no further work was developed to better understand and exploit the capabilities of Chiralpak® IA both for the analytical and preparative chiral separations of nadolol stereoisomers. This work will present a complete methodology concerning experimental, modelling and simulation results. Both the CHIRALPAK® AD and CHIRALPAK® IA CSP will be evaluated. The selection of the proper CSP/solvent combination for preparative operation will be fully study taking into account the screening strategy proposed by Zhang et al6. Additional results include the measurement of nadolol stereoisomers solubilities, equilibrium adsorption data and fixed bed (breakthroughs) experiments. The complete screening of CSP/solvent combination will lead to the choice of the better solutions for the separation of nadolol stereoisomers, considering the target component or components to be obtained. Simulation and experimental results will be presented for the multicomponent separation of nadolol stereoisomers by Simulated Moving Bed adsorption process

Influence of mobile phase composition on the preparative separation of profens by chiral liquid chromatography

The chirality of drugs is an important issue for the pharmaceutical industry, since the different enantiomers of a racemic drug may have distinct pharmacological activities, pharmacokinetic and pharmacodynamic effects. Because of its chiral selectivity, human body reacts with a racemic drug differently, and metabolise each enantiomer on separate pathways producing different pharmacological activity. Thus, one isomer may produce the desired therapeutic activities, while the other may be inactive or even, in worst cases, produce unwanted effects. Flurbiprofen [2-(2-fluoroo4-biphenyl)-propionic acid] and ketoprofen [2-(3-benzoylphenyl)-propionic acid] belong to a family of chemicals named 2-arylpropionic acids, or profens, an important sub-class of the frequently prescribed and used drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). A considerable number of these drugs possess antipyretic activity in addition to its analgesic and antiinflammatory actions, and thus have utility in the treatment of fever. The main primary indications for NSAIDs therapy include rheumatoid arthritis, osteoarthritis, acute gouty arthritis, ankylosing spondylitis and dysmenorrhea (DeRuiter, 2002). The importance of this class of drugs is supported by U,e fact that, in the last twenty years, drugs like aspirin, phenazone derivatives or acetaminophen are being supplemented by profens (Brune and Hinz, 1998)

Psychosocial Aspects Associated with Pain Perception in Individuals Undergoing Coronary Surgery

Objectivo: Identificar os factores psicossociais que influenciam a percepção da dor pós-operatória em doentes submetidos a cirurgia de revascularização do miocárdio (CRM). Material e Métodos: Estudo exploratório correlacional de 91 doentes (71 homens e 20 mulheres) submetidos a CRM (pontagem aortocoronária) por esternotomia. A idade média era de 63,8 ± 9,6 anos (entre 39 e 84). Foram utilizados os seguintes instrumentos: Escala Analógica Visual às 24, 48 e 96 horas do pós-operatório; Questionário de Caracterização Demográfica; Mental Health Inventory de 5 itens; Percepção de Saúde Geral (SF-36); Escala de Expectativas de Dor; Escala de Percepção de Apoio; Escala de Expectativas de Auto-eficácia; Satisfação com o tratamento, médicos e enfermeiros (American Pain Society Questionnaire) aplicados às 96 horas após a cirurgia. Resultados: Os doentes que apresentaram expectativas elevadas de dor, percepcionaram maior apoio, apresentaram níveis elevados de auto-eficácia para lidar com a dor ou, se pertenciam ao sexo masculino, sentiram menos dor. De igual modo, os doentes que apresentaram melhor saúde mental, percepcionaram a sua saúde como boa e os doentes que expressaram maior satisfação com o tratamento sentiram menos dor. A dor não foi influenciada pela idade, grau de escolaridade ou pela satisfação com a conduta de médicos e enfermeiros. Conclusão: Após as primeiras 48 horas do pós-operatório, a experiência de dor é influenciada por factores psicossociais, em particular pela expectativa de dor, expectativa de auto-eficácia, apoio percebido, percepção da saúde geral, percepção de saúde mental e satisfação com o tratamento para a dor. Perante os resultados, evidencia-se a necessidade de conjugar conhecimentos no sentido de dar respostas mais alargadas e de carácter multidisciplinar no tratamento da dor pós-operatória em CRM devendo, a par de outros aspectos, focar-se na gestão das expectativas dos doentes

An atlas of line profile studies for SU UMa type cataclysmic variables

We present H-alpha line-profile analyses for the seven SU UMa type dwarf novae AK Cnc, WX Cet, AQ Eri, VW Hyi, RZ Leo, TU Men, and HS Vir. All data sets are treated in the same manner, applying a sequence of techniques for each system. The basic ingredients of this sequence are the diagnostic diagram to determine the zero point of the orbital phase, and Doppler tomography to visualise the emission distribution. We furthermore introduce a new qualitative way of to evaluate the Doppler fit, by comparing the line profile of the reconstructed with the original spectrum in the form of the V/R plot. We present the results of the analysis in the compact form of an atlas, allowing a direct comparison of the emission distribution in our targets. Although most of the data sets were not taken with the intention of a line-profile analysis, we obtain significant results and are able to indicate the type of the additional emission in these systems. Our objects should have in principle very similar physical properties, i.e. they cover only a small range in orbital periods, mass ratios, and mass-transfer rates. Nevertheless, we find a large variety of phenomena both with respect to the individual systems and also within individual data sets of the same object. This includes `canonical' additional emission components from the secondary star and the bright spot, but also emission from the leading side of the accretion disc.Comment: 20 pages, 25 figures, accepted for publication in A&A, figures have been diminished in size and qualit

Fish assemblages across the Mediterranean Sea and the effects of protection from fishing = I Popolamenti ittici nel Mediterraneo e gli effetti della protezione dall’impatto della pesca

Several studies have assessed the effectiveness of individual marine protected areas (MPAs) in protecting fish assemblages, but regional assessments of multiple parks are scarce. Here fish surveys using visual census were done in marine parks and fished areas at 31 locations across the Mediterranean Sea. Fish species richness, diversity and biomass (especially of top predators) were higher in MPAs compared to fished areas, and community structure differed significantly between MPAs and fished areas. Results suggest that MPAs are generally effective means to protect and recover fish populations and assemblages

Optimizing interpolation of shoot density data from a Posidonia oceanica seagrass bed

A case study on the optimization of Posidonia oceanica density interpolation, using a data set from a large meadow at Porto Conte Bay (NW Sardinia, Italy), is presented. Ordinary point kriging, cokriging and a weighted average based on inverse square distance were used to interpolate density data measured in 36 sampling stations. The results obtained from different methods were then compared by means of a leave-one-out cross-validation procedure. The scale at which interpolation was carried out was defined on the basis of the Hausdorff dimension of the variogram. Optimizing spatial scale and data points search strategy allowed obtaining more accurate density estimates independently of the interpolation method

Lentiviral vectors with amplified beta cell-specific gene expression.

An important goal of gene therapy is to be able to deliver genes, so that they express in a pattern that recapitulates the expression of an endogenous cellular gene. Although tissue-specific promoters confer selectivity, in a vector-based system, their activity may be too weak to mediate detectable levels in gene-expression studies. We have used a two-step transcriptional amplification system to amplify gene expression from lentiviral vectors using the human insulin promoter. In this system, the human insulin promoter drives expression of a potent synthetic transcription activator (the yeast GAL4 DNA-binding domain fused to the activation domain of the Herpes simplex virus-1 VP16 activator), which in turn activates a GAL4-responsive promoter, driving the enhanced green fluorescent protein reporter gene. Vectors carrying the human insulin promoter did not express in non-beta-cell lines, but expressed in murine insulinoma cell lines, indicating that the human insulin promoter was capable of conferring cell specificity of expression. The insulin-amplifiable vector was able to amplify gene expression five to nine times over a standard insulin-promoter vector. In primary human islets, gene expression from the insulin-promoted vectors was coincident with insulin staining. These vectors will be useful in gene-expression studies that require a detectable signal and tissue specificity