A Model for QCD at High Density and Large Quark Mass

We study the high density region of QCD within an effective model obtained in the frame of the hopping parameter expansion and choosing Polyakov type of loops as the main dynamical variables representing the fermionic matter. To get a first idea of the phase structure, the model is analyzed in strong coupling expansion and using a mean field approximation. In numerical simulations, the model still shows the so-called sign problem, a difficulty peculiar to non-zero chemical potential, but it permits the development of algorithms which ensure a good overlap of the Monte Carlo ensemble with the true one. We review the main features of the model and present calculations concerning the dependence of various observables on the chemical potential and on the temperature, in particular of the charge density and the diquark susceptibility, which may be used to characterize the various phases expected at high baryonic density. We obtain in this way information about the phase structure of the model and the corresponding phase transitions and cross over regions, which can be considered as hints for the behaviour of non-zero density QCD.Comment: 21 pages, 29 figure

In vitro cultured progenitors and precursors of cardiac cell lineages from human normal and post-ischemic hearts.

The demonstration of the presence of dividing primitive cells in damaged hearts has sparked increased interest about myocardium regenerative processes. We examined the rate and the differentiation of in vitro cultured resident cardiac primitive cells obtained from pathological and normal human hearts in order to evaluate the activation of progenitors and precursors of cardiac cell lineages in post-ischemic human hearts. The precursors and progenitors of cardiomyocyte, smooth muscle and endothelial lineage were identified by immunocytochemistry and the expression of characteristic markers was studied by western blot and RT-PCR.The amount of proteins characteristic for cardiac cells (alpha-SA and MHC, VEGFR-2 and FVIII, SMA for the precursors of cardiomyocytes, endothelial and smooth muscle cells, respectively) inclines toward an increase in both alpha-SA and MHC. The increased levels of FVIII and VEGFR2 are statistically significant, suggesting an important re-activation of neoangiogenesis. At the same time, the augmented expression of mRNA for Nkx 2.5, the trascriptional factor for cardiomyocyte differentiation, confirms the persistence of differentiative processes in terminally injured hearts. Our study would appear to confirm the activation of human heart regeneration potential in pathological conditions and the ability of its primitive cells to maintain their proliferative capability in vitro. The cardiac cell isolation method we used could be useful in the future for studying modifications to the microenvironment that positively influence cardiac primitive cell differentiation or inhibit, or retard, the pathological remodeling and functional degradation of the heart

Phase diagram of the lattice Wess-Zumino model from rigorous lower bounds on the energy

We study the lattice N=1 Wess-Zumino model in two dimensions and we construct a sequence $\rho^{(L)}$ of exact lower bounds on its ground state energy density $\rho$, converging to $\rho$ in the limit $L\to\infty$. The bounds $\rho^{(L)}$ can be computed numerically on a finite lattice with $L$ sites and can be exploited to discuss dynamical symmetry breaking. The transition point is determined and compared with recent results based on large-scale Green Function Monte Carlo simulations with good agreement.Comment: 32 pages, 12 figure

Arte rupestre, tiempo y espacio en La Damiana (Quebrada de Incahuasi, Salta, Argentina)

In this paper, we present the results of a spatial analysis of rock art from La Damiana (Quebrada de Incahuasi, Salta). We studied 163 engraved blocks, part of the Section 1 of the site, in order to define changes and continuities in the pastoralist landscapes from the Formative (700 B.C. – A.D. 1000) to the Late period (A.D. 1000 – 1430). We were interested in defining how later representations were spatially organized in relation to preexisting ones, and how the earlier engravings participated in the spatial arrangements of later pastoralist landscapes. The methodological approach supported by the use of GIS tools, sought to define the rock art’s spatial structure during each period and at different scales: a “block” scale that considered distributional and visual aspects for each chronological subset, and an “intra-block” scale that focused on reused surfaces, representations, and their spatial relationships. We observed a recurrence in the occupation of spaces and in the form in which they had been modified through rock art, with greater intensity during the Late period. Moreover, we suggest that at this moment new themes and modes of representation arose, even while some preexisting ones were still in use.En este artículo se presentan los resultados del análisis espacial de las manifestaciones rupestres de La Damiana (Quebrada de Incahuasi, Salta). El conjunto estudiado abarca 163 bloques grabados que componen el Tramo 1. A partir de su análisis se busca definir cambios y continuidades en los paisajes pastoriles desde el período Formativo (700 a.C. – 1000 d.C.) al Tardío (1000 – 1430 d.C.). Interesa conocer de qué manera las representaciones tardías se organizaron espacialmente y con respecto a otras preexistentes y cómo los grabados más tempranos participaron en el marco de las estrategias de configuración de los paisajes pastoriles posteriores. Se parte de un enfoque metodológico apoyado por el empleo de herramientas SIG y que indaga acerca de la estructura espacial del arte rupestre de cada periodo en una escala de bloque, abordando aspectos distribucionales y visuales de cada subconjunto, y otra intrabloque, que considera los soportes reutilizados, los motivos en estos plasmados y sus relaciones espaciales. Se observa una recurrencia en los espacios ocupados y la forma en que han sido intervenidos a partir del arte rupestre, aunque con una mayor intensidad durante el Tardío. A la vez que surgen nuevos temas y formas de representación, se sugiere la vigencia de otros preexistentes

Role of PET gamma detection in radioguided surgery: a systematic review

Purpose This systematic review aimed to collect published studies concerning intraoperative gamma detection of positronemitting tracers for radioguided surgery (RGS) applications. Methods A systematic literature search of studies published until October 2022 was performed in Pubmed, Web Of Science, Central (Cochrane Library) and Scopus databases, including the following keywords: “Positron Emission Tomography” OR “PET” AND “Gamma” OR “γ” AND “Probe” AND “Radioguided Surgery” OR “RGS”. The included studies had to concern RGS procedures performed in at least 3 patients, regardless of the administered radiopharmaceutical and the field of application. Results Among to the 17 selected studies, all published between 2000 and 2022, only 2 investigations were conducted with gallium-68 (68Ga)-labeled somatostatin analogues, with fluorine-18-fluoro-2-deoxyglucose ([ 18F]FDG) being the most commonly used agent for RGS applications. Almost all studies were performed in oncologic patients, with only one paper also including inflammatory and infectious findings. The analysis showed that the largest part of procedures was performed through the intraoperative use of conventional gamma probes, not specifically designed for the detection of annihilation photons (n = 9), followed by PET gamma probes (n = 5) and with only three studies involving electronic collimation. Conclusions Regardless of the intraoperative devices, RGS with positron emitters seems to lead to significant improvements in surgeons’ ability to obtain a complete resection of tumors, even if the nature of photons resulting from positron–electron collision still remains extremely challenging and requires further technical advances

Assessment of biological kinetics in a conventional municipal WWTP by means of the oxygen uptake rate method

Pollution control of surface water bodies requires stringent checks on wastewater treatment plants performances. The satisfactory operation of biological treatment, commonly performed by means of activated sludge processes, requires a number of controlling and monitoring procedures. Suitable respirometric techniques for the determination of the kinetic parameters that regulate biological processes have been implemented in order to achieve this aim. This paper describes the results of an experimental research carried out in a conventional Italian municipal wastewater treatment plant. Particularly, the research has been finalized to both evaluate the biological process for the removal of biodegradable pollutants, such as carbonaceous substrates and ammonia nitrogen, and to collect data in order to evaluate a possible plant upgrade. Heterotrophic and autotrophic biomass kinetic parameters have been examined using respirometric techniques based on oxygen uptake measurements. The research performed makes a valuable contribution toward verifying the reliability of the values proposed in the literature for some kinetic parameters, which have been commonly used for a long time

A Systematic Review of Meta-Analyses on Gene Polymorphisms and Gastric Cancer Risk

BACKGROUND: Individual variations in gastric cancer risk have been associated in the last decade with specific variant alleles of different genes that are present in a significant proportion of the population. Polymorphisms may modify the effects of environmental exposures, and these gene-environment interactions could partly explain the high variation of gastric cancer incidence around the world. The aim of this report is to carry out a systematic review of the published meta-analyses of studies investigating the association between gene polymorphisms and gastric cancer risk, and describe their impact at population level. Priorities on the design of further primary studies are then provided. METHODS: A structured bibliographic search on Medline and EMBASE databases has been performed to identify meta-analyses on genetic susceptibility to gastric cancer, without restriction criteria. We report the main results of the meta-analyses and we describe the subgroup analyses performed, focusing on the detection of statistical heterogeneity. We investigated publication bias by pooling the primary studies included in the meta-analyses, and we computed the population attributable risk (PAR) for each polymorphism. RESULTS: Twelve meta-analyses and one pooled-analysis of community based genetic association studies were included, focusing on nine genes involved in inflammation (IL-1beta, IL-1RN, IL-8), detoxification of carcinogens (GSTs, CYP2E1), folate metabolism (MTHFR), intercellular adhesion (E-cadherin) and cell cycle regulation (p53). According to their random-Odds Ratios, individuals carrying one of the IL-1RN *2, IL-1beta -511T variant alleles or homozygotes for MTHFR 677T are significantly at higher risk of gastric cancer than those with the wild type homozygote genotypes, showing high PARs. The main sources of heterogeneity in the meta-analyses were ethnicity, quality of the primary study, and selected environmental co-exposures. Effect modification by Helicobacter pylori infection for subjects carrying the unfavourable variant of IL-1 polymorphisms and by low folate intake for individuals homozygotes for MTHFR 677T allele has been reported, while genes involved in the detoxification of carcinogens show synergistic interactions. Publication bias was observed (Egger test, p = 0.03). DISCUSSION: The published meta-analyses included in our systematic review focused on polymorphisms having a small effect in increasing gastric cancer risk per se. Nevertheless, the risk increase by interacting with environmental exposures and in combination with additional unfavourable polymorphisms. Unfortunately meta-analyses are underpowered for many subgroup analyses, so additional primary studies performed on larger population and collecting data on environmental and genetic co-exposures are demanded