Lorentz-covariant Hamiltonian analysis of BF gravity with the Immirzi parameter

We perform the Lorentz-covariant Hamiltonian analysis of two Lagrangian action principles that describe general relativity as a constrained BF theory and that include the Immirzi parameter. The relation between these two Lagrangian actions has been already studied through a map among the fields involved. The main difference between these is the way the Immirzi parameter is included, since in one of them the Immirzi parameter is included explicitly in the BF terms, whereas in the other (the CMPR action) it is in the constraint on the B fields. In this work we continue the analysis of their relationship but at the Hamiltonian level. Particularly, we are interested in seeing how the above difference appears in the constraint structure of both action principles. We find that they both possess the same number of first-class and second-class constraints and satisfy a very similar (off-shell) Poisson-bracket algebra on account of the type of canonical variables employed. The two algebras can be transformed into each other by making a suitable change of variablesComment: LaTeX file, no figure

Citalopram plus low-dose pipamperone versus citalopram plus placebo in patients with major depressive disorder: an 8-week, double-blind, randomized study on magnitude and timing of clinical response

Background: Selective serotonin reuptake inhibitors take several weeks to achieve their full antidepressant effects. Post-synaptic 5-HT<sub>2A</sub> receptor activation is thought to be involved in this delayed therapeutic effect. Pipamperone acts as a highly selective 5-HT<sub>2A</sub>/D<sub>4</sub> antagonist when administered in low doses. The purpose of this study was to compare citalopram 40 mg once daily plus pipamperone 5 mg twice daily (PipCit) versus citalopram plus placebo twice daily for magnitude and onset of therapeutic effect. Method: An 8-week, randomized, double-blind study in patients with major depressive disorder was carried out. Results: The study population comprised 165 patients (citalopram and placebo, n=82; PipCit, n=83) with a mean baseline Montgomery–Asberg Depression Rating Scale (MADRS) score of 32.6 (S.D.=5.5). In the first 4 weeks, more citalopram and placebo than PipCit patients discontinued treatment (18% v. 4%, respectively, p=0.003). PipCit patients had significantly greater improvement in MADRS score at week 1 [observed cases (OC), p=0.021; last observation carried forward (LOCF), p=0.007] and week 4 (LOCF, p=0.025) but not at week 8 compared with citalopram and placebo patients. Significant differences in MADRS scores favoured PipCit in reduced sleep, reduced appetite, concentration difficulties and pessimistic thoughts. Mean Clinical Global Impression–Improvement scores were significantly improved after 1 week of PipCit compared with citalopram and placebo (OC and LOCF, p=0.002). Conclusions: Although the MADRS score from baseline to 8 weeks did not differ between groups, PipCit provided superior antidepressant effects and fewer discontinuations compared with citalopram and placebo during the first 4 weeks of treatment, especially in the first week

A statistical mechanics approach to autopoietic immune networks

The aim of this work is to try to bridge over theoretical immunology and disordered statistical mechanics. Our long term hope is to contribute to the development of a quantitative theoretical immunology from which practical applications may stem. In order to make theoretical immunology appealing to the statistical physicist audience we are going to work out a research article which, from one side, may hopefully act as a benchmark for future improvements and developments, from the other side, it is written in a very pedagogical way both from a theoretical physics viewpoint as well as from the theoretical immunology one. Furthermore, we have chosen to test our model describing a wide range of features of the adaptive immune response in only a paper: this has been necessary in order to emphasize the benefit available when using disordered statistical mechanics as a tool for the investigation. However, as a consequence, each section is not at all exhaustive and would deserve deep investigation: for the sake of completeness, we restricted details in the analysis of each feature with the aim of introducing a self-consistent model.Comment: 22 pages, 14 figur

Hipotiroidismo subclínico y factores de riesgo cardiovascular

Objetivo: Conocer la prevalencia del hipotiroidismo subclínico en la población general de un centro de salud urbano y describir las características clínicas y factores de riesgo cardiovascular de los pacientes con hipotiroidismo subclínico. Métodos: Se realizó un estudio observacional descriptivo, transversal, retrospectivo, revisando las historias clínicas de los pacientes incluidos en la muestra desde junio de 2005 hasta julio de 2007. Se analizaron las siguientes variables; Datos generales: edad y sexo. Antecedentes familiares: patología tiroidea y otras enfermedades. Antecedentes personales: cardiovasculares, pulmonares, enfermedades autoinmunes, alteraciones gineco-obstétricas, diabetes, hipertensión (HT), dislipemia, obesidad, alteraciones psiquiátricas y hematológicas. Datos de laboratorio: niveles de TSH, niveles de T4 libre,presencia de anticuerpos antiperoxidasa, niveles de colesterol total y sus fracciones. Resultados: La prevalencia de la muestra de 100 pacientes recogida durante 8 meses fue de 3,8% de la población general mayor de 14 años, de la cual 79 eran mujeres y 21 eran hombres. El 13% eran diabéticos tipo 2, 23% tenían HT y un 40% tenían dislipemia. Sobrepeso y obesidad estaban presentes en un 26%. El nivel medio de TSH fue 6.92 ± 2,29 U/ml y el nivel medio de T4 libre fue 1,16 ± 0,16 ng/ml. Conclusiones: La prevalencia del hipotiroidismo subclínico fue 3,8%. sobre todo en mujeres con una edad media de 46 años. La incidencia de factores de riesgo cardiovascular en los sujetos estudiados es mayor en DM (13%), similar a la población general en cuanto a la dislipemia (40%) y obesidad (20%) y menor en HTA (23%). En nuestro estudio no se observa una pauta común en el manejo del hipotiroidismo subclínico, siendo necesaria la implementación y promoción de guías de actuación en Atención PrimariaObjective: To determine the prevalence of subclinical hypothyroidism in the general population of an urban health center and describe the clinical characteristics and cardiovascular risk factors in patients with subclinical hypothyroidism. Methods: An observational study, retrospective, reviewing the medical histories of patients sampled from June 2005 until July 2007. We analyzed the following variables; facts: age and sex. Family history thyroid disease and other diseases. Personal history: cardiovascular pulmonary autoimmune, alterations gynecology obstetric diabetes, hypertension (HT) dislipemia, obesity, psychiatric alterations and haematological. Laboratory data: novel TSH, free T4, antiperoxidase antibodies, total cholesterol and its fractions. Results: The prevalence of the sample of 100 patients collected over 8 months was 3.8% in the general population over 14 years, of which 79 were women and 21 were men. 13% were type 2 diabetics, 23% had HT and 40% had dyslipidemia. Overweight and obesity were present in 26%. The average level of TSH was 6.92 ± 2.29 U/ml and the average level of free T4 was 1.16 ± 0.16 ng/ml. Conclusions: Prevalence subclinical hypothyroidism was 3.8%. especially in women with a mean age of 46. The incidence of cardiovascular risk factors in the subjects studied is higher in DM (13%), similar to general population in terms of dyslipidemia (40%) and obesity (23%) and lowest in hypertension (23%). In our study we observed a common pattern in the management of subclinical hypothyroidism, requiring the implementation and promotion of practice guidelines in primary car

Species appeal predicts conservation status

Conservation of animal species should start from real needs of protection and intervention shown by species and their habitats, but it is often driven by the perception which humans have of species, as the latter enables fund raising and attracts financial resources for conservation actions. However, this approach dominated by the so-called flagship species has been severely criticised, because of the associated risk of directing resources to charismatic species while neglecting threatened ones. An analysis of conservation status in relation to species appeal, habitat, sociality, body length and population size outlined how the more "appealing" bird species in Italy have better conservation status. This is likely due to an over-representation of most appealing species in conservation projects and suggests that a more careful and status-based prioritization of conservation efforts should be adopted

Optimality of mutation and selection in germinal centers

The population dynamics theory of B cells in a typical germinal center could play an important role in revealing how affinity maturation is achieved. However, the existing models encountered some conflicts with experiments. To resolve these conflicts, we present a coarse-grained model to calculate the B cell population development in affinity maturation, which allows a comprehensive analysis of its parameter space to look for optimal values of mutation rate, selection strength, and initial antibody-antigen binding level that maximize the affinity improvement. With these optimized parameters, the model is compatible with the experimental observations such as the ~100-fold affinity improvements, the number of mutations, the hypermutation rate, and the "all or none" phenomenon. Moreover, we study the reasons behind the optimal parameters. The optimal mutation rate, in agreement with the hypermutation rate in vivo, results from a tradeoff between accumulating enough beneficial mutations and avoiding too many deleterious or lethal mutations. The optimal selection strength evolves as a balance between the need for affinity improvement and the requirement to pass the population bottleneck. These findings point to the conclusion that germinal centers have been optimized by evolution to generate strong affinity antibodies effectively and rapidly. In addition, we study the enhancement of affinity improvement due to B cell migration between germinal centers. These results could enhance our understandings to the functions of germinal centers.Comment: 5 figures in main text, and 4 figures in Supplementary Informatio

Emission and chemistry of organic carbon in the gas and aerosol phase at a sub-urban site near Mexico City in March 2006 during the MILAGRO study

Volatile organic compounds (VOCs) and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives). Diurnal variations of hydrocarbons, elemental carbon (EC) and hydrocarbon-like organic aerosol (HOA) were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA) and water-soluble organic carbon (WSOC) stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the U.S., but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the U.S., due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the U.S. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC), and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps not dissimilar from observations in the U.S

Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin

What is the level of consciousness of the psychedelic state? Empirically, measures of neural signal diversity such as entropy and Lempel-Ziv (LZ) complexity score higher for wakeful rest than for states with lower conscious level like propofol-induced anesthesia. Here we compute these measures for spontaneous magnetoencephalographic (MEG) signals from humans during altered states of consciousness induced by three psychedelic substances: psilocybin, ketamine and LSD. For all three, we find reliably higher spontaneous signal diversity, even when controlling for spectral changes. This increase is most pronounced for the single-channel LZ complexity measure, and hence for temporal, as opposed to spatial, signal diversity. We also uncover selective correlations between changes in signal diversity and phenomenological reports of the intensity of psychedelic experience. This is the first time that these measures have been applied to the psychedelic state and, crucially, that they have yielded values exceeding those of normal waking consciousness. These findings suggest that the sustained occurrence of psychedelic phenomenology constitutes an elevated level of consciousness - as measured by neural signal diversity

Sixty years of habitat decline : impact of land-cover changes in northern Italy on the decreasing ortolan bunting Emberiza hortulana

Habitat loss and degradation are main global threats to biodiversity, and land-use changes in agriculture-dominated landscapes are crucial for an important portion of biodiversity, especially in Europe. We evaluated the effects of land-use changes (1954–2012) on a threatened species, the ortolan bunting, in an agricultural area crucial for its conservation in Italy. We built a distribution model for ortolan bunting in current landscapes and then re-projected it to past scenarios (1954 and 1999–2000). We evaluated the most important land-use changes occurred and estimated their effects on habitat suitability. Bunting occurrence was mostly affected by the extent of grassland (positively; used as foraging/breeding ground), shrubland (quadratic effect; perches/shelter), forest and urbanized land (negatively), and by solar radiation (positively) and slope (quadratic), consistent with other studies carried out especially in southern Europe. The potential distribution of the species was much larger in the past: the estimated decline in suitable habitat is 44–72 % (since 1999–2000/1954), coherent with historical data suggesting strong decline and contraction. Changes in suitability (1954–2012) were mostly associated with changes in the cover of forest, vineyards and abandoned areas (negatively), and shrubland (positively). Land-use/land-cover changes are the main drivers of species occurrence and of habitat decline. The heterogeneous landscape of hilly/low-mountain sites in this area, characterized by a mix of habitats offering complementary resources to ortolan buntings and other species of conservation concern, is currently threatened by abandonment and intensification, but its maintenance may be promoted by a correct definition of Rural Development Programme measures

Microstructural Impact of Si and Ni During High Temperature Quenching and Partitioning Process in Medium-Mn Steels

Austenite stabilization through carbon partitioning from martensite into austenite is an essential aspect of the quenching and partitioning (Q&P) process. Substitutional alloying elements are often included in the chemical composition of Q&P steels to further control the microstructure development by inhibiting carbide precipitation (silicon) and further stabilize austenite (manganese and nickel). However, these elements can interfere in the microstructure development, especially when high partitioning temperatures are considered. In this study, the microstructural development during the Q&P process of four low-carbon, medium-manganese steels with varying contents of silicon and nickel is investigated. During partitioning at 400 °C, silicon hinders cementite precipitation in primary martensite thereby assisting carbon partitioning from martensite to austenite. During partitioning at temperatures of 500 °C and 600 °C, presence of nickel inhibits pearlite formation and promotes austenite reversion, respectively. It is observed that the stabilization of austenite is significantly enhanced through the addition of nickel by slowing down the kinetics of competitive reactions that are stimulated during the partitioning stage. Results of this study provide an understanding of the interplay among carbon, silicon and nickel during Q&P processing that will allow the development of new design strategies to tailor the microstructure of this family of alloys.This research work has been carried out in the framework of the HighQP project (Proposal Number: 709855), funded by the Research Fund for Coal and Steel (RFCS)