Bose-Einstein condensation and critical behavior of two-component bosonic gases

We study Bose-Einstein condensation (BEC) in three-dimensional two-component bosonic gases, characterizing the universal behaviors of the critical modes arising at the BEC transitions. For this purpose, we use field-theoretical (FT) renormalization-group (RG) methods and perform mean-field and numerical calculations. The FT RG analysis is based on the Landau-Ginzburg-Wilson Phi4 theory with two complex scalar fields which has the same symmetry as the bosonic system. In particular, for identical bosons with exchange Z_2,e symmetry, coupled by effective density-density interactions, the global symmetry is Z_2e X U(1) X U(1). At the BEC transition it may break into Z_2,e X Z_2 X Z_2 when both components condense simultaneously, or to U(1) X Z_2 when only one component condenses. This implies different universality classes for the corresponding critical behaviors. Numerical simulations of the two-component Bose-Hubbard model in the hard-core limit support the RG prediction: when both components condense simultaneously, the critical behavior is controlled by a decoupled XY fixed point, with unusual slowly-decaying scaling corrections arising from the on-site inter-species interaction.Comment: 13 page

Destruction of dimethyl ether and methyl formate by collisions with He+^+

To correctly model the abundances of interstellar complex organic molecules (iCOMS) in different environments, both formation and destruction routes should be appropriately accounted for. While several scenarios have been explored for the formation of iCOMs via grain and gas-phase processes, much less work has been devoted to understanding the relevant destruction pathways, with special reference to (dissociative) charge exchange or proton transfer reactions with abundant atomic and molecular ions such as He$^+$, H$_3^+$ and HCO$^+$. By using a combined experimental and theoretical methodology we provide new values for the rate coefficients and branching ratios (BRs) of the reactions of He$^+$ ions with two important iCOMs, namely dimethyl ether (DME) and methyl formate (MF). We also review the destruction routes of DME and MF by other two abundant ions, namely H$_3^+$ and HCO$^+$. Based on our recent laboratory measurements of cross sections and BRs for the DME/MF + He$^+$ reactions over a wide collision energy range, we extend our theoretical insights on the selectivity of the microscopic dynamics to calculate the rate coefficients $k(T)$ in the temperature range from 10 to 298 K. We implement these new and revised kinetic data in a general model of cold and warm gas, simulating environments where DME and MF have been detected. Due to stereodynamical effects present at low collision energies, the rate coefficients, BRs and temperature dependences here proposed differ substantially from those reported in KIDA and UDfA, two of the most widely used astrochemical databases. These revised rates impact the predicted abundances of DME and MF, with variations up to 40% in cold gases and physical conditions similar to those present in prestellar coresComment: accepted for publication in Astronomy and Astrophysics (manuscript no. AA/2018/34585), 10 pages, 3 figure

Voriconazole treatment of Candida tropicalis meningitis: persistence of (1,3)-b-D-glucan in the cerebrospinal fluid is a marker of clinical and microbiological failure

Introduction: Infections are still the most common complications of cerebral shunt procedures. Even though fungal etiologies are considered to be rare, they are associated with significant morbidity and mortality. Due to their uncommonness, diagnostic procedures and optimal therapy are poorly defined. We report a case of Candida tropicalis infection of ventriculo-peritoneal cerebrospinal fluid (CSF) shunt in a 49-year-old immune competent male treated with voriconazole (VOR). Methods: Microbiological and CSF markers (1,3-b-D-glucan-BDG) of fungal infection, biofilm production capacity, sensitivity of serial isolates of the pathogen, and the concentration of the antifungal drug have been monitored and related to the clinical course of this infection. Results: Despite appropriate treatment with VOR, in terms of adequate achieved CSF drug concentrations and initial effective therapeutic response, loss of VOR susceptibility of the C tropicalis and treatment failure were observed. Conclusion: Biofilm production of the C. tropicalis isolate might have had a significant role in treatment failure. Of interest, clinical and microbiological unfavorable outcome was anticipated by persistence of BDG in CSF. Rising titers of this marker were associated with relapse of fungal infection

The presence and localization of apelin in the sheep abomasum: impact of diets characterized by different chemical composition

The apelinergic system is a complex system including the apelin peptide (AP), initially isolated in 1998 from bovine stomach homogenates and its receptor, named APJ receptor. The apelin peptide is extensively expressed in several human and laboratory animal organs (heart, lung, brain, mammary gland). Between the different roles hypothesize for apelin there are also the control of blood pressure and the stimulation of drinking behavior in rats. Recently its expression was also evidenced in the basal glandular portion of the stomach in laboratory animals, allowing to hypothesize its intervention in the control of acid secretion. No data concerning its presence and distribution in the abomasums of the sheep are present at the moment. So, we decided to test the presence and distribution of apelin in the abomasums of the sheep and the possible existence of a variability as a consequence of the different water content of the diet.The experiment was conducted using 50 sheep fed on Apennine semi-natural pasture for two experimental periods: in the first period the animals were fed for 45 days on the pasture at the maximum of its flowering; in the second one the animals were fed on the same pasture until its maximum dryness but the half of them daily received adiet integration of cereals. At the end of each experimental period, some animals were regularly slaughtered at the local abattoir, the abomasum specimens were immediately removed and some of them processed for routine tissue-embedding preparation while other for molecular biology. The immunohistochemical reaction was visualized on 5 µm serial sections, using a primary rabbit polyclonal antibody (anti-AP), the avidin-biotin-complex and the DAB as the chromogen. The immunohistochemical study showed a peculiar immunoreaction for AP in the abomasum of the animals examined. In particular, a immunopositive reaction for AP was evident in the cells of the basal third of the tubular glands and they were mainly of the closed type, with an oval or round shape and contained many perinuclear granules. The immunopositive reactions didn’t evidence any difference both in the localization and in the number of the positive cells, between the different groups. Immuno-positivity for AP was not observed in any other histological structure or in the sections utilized as negative controls.These results allow us to conclude that AP is present in the glandular tissue of the abomasums of the sheep, as observed in laboratory animals, with a peculiar cytoplasmatic localization and to hypothesize that AP is involved in the control of gastric secretion, probably via APJ receptor. The AP expression in the stomach doesn’t seem to be influenced by the water content of the diets with a positivity that appears to be localized in the same glandular portion between the different animal groups

Modulation of tryptophan/serotonin pathway by probiotic supplementation in human immunodeficiency virus-positive patients: preliminary results of a new study approach

Background: To date, no data are available regarding the effects of probiotics on the pathway of tryptophan/serotonin metabolism among human immunodeficiency virus (HIV) 1–infected individuals. Because a condition of dysbiosis might be responsible for the altered use of tryptophan described in this population, the aim of this study was to investigate the link between probiotic supplementation and serotonin levels in combined antiretroviral therapy–treated patients and the subsistence of an interplay with inflammation. Methods: We conducted a pilot study that included 8 HIV-positive subjects. We collected blood and fecal samples before and after 6 months of probiotic supplementation, to measure the level of serotonin in serum and tryptophan in stool, the expression of CD38 and HLADR on peripheral CD4+ T lymphocytes (as immune activation markers), the expression of indoleamine 2,3-dioxygenase 1 messenger RNA (mRNA) and IFN-γ mRNA (as markers of tryptophan metabolism and systemic inflammation). Results: After probiotic supplementation, we observed a significant increase in concentration of serum serotonin (P=.008) and a decreased level of tryptophan in plasma. Moreover, a significant reduction in CD38 and HLA-DR expression on the surface of peripheral CD4+ T cells (P=.008) and a reduced expression of indoleamine 2,3-dioxygenase 1 mRNA on peripheral blood mononuclear cells (P=.04) were observed. Conclusions: Considering that this probiotic (Vivomixx® in EU; Visbiome® in USA) has an influence on tryptophan metabolism, larger studies on this topic are needed

Physiological and ultrastructural effects of acute ozone fumigation in the lichen Xanthoria parietina: the role of parietin and hydration state

The physiological and ultrastructural effects induced by acute exposure to ozone (O3) were investigated in the lichen Xanthoria parietina. Our working hypothesis was that parietin content and hydration of the thalli may play a role in the modulation of the effects of O3 exposure. Four batches of X. parietina samples, dry and wet, with (P+) and without (Pâ\u88\u92) parietin, were fumigated for 1 h with 3 ppm O3. The effects of O3 were assessed immediately after the fumigation and after one week of recovery under controlled conditions. O3 fumigation caused physiological and ultrastructural impairment both to the photobiont and the mycobiont, irrespective if samples were fumigated wet or dry, and P+ or Pâ\u88\u92. However, one week after fumigation, a recovery was observed in P+ samples for the photobiont and in dry samples for the mycobiont. We suggest that the hydration state may play a major role in determining the severity of the damage, while the presence of parietin may promote the recovery. Our results provide physiological and ultrastructural basis to explain the ecological insensitivity of lichens to high environmental levels of ozone occurring during dry Mediterranean summers

Results on Proton-Irradiated 3D Pixel Sensors Interconnected to RD53A Readout ASIC

Test beam results obtained with 3D pixel sensors bump-bonded to the RD53A prototype readout ASIC are reported. Sensors from FBK (Italy) and IMB-CNM (Spain) have been tested before and after proton-irradiation to an equivalent fluence of about $1$ $\times$ $10^{16}$ $\text{n}_{\text{eq}}$ cm$^{-2}$ (1 MeV equivalent neutrons). This is the first time that one single collecting electrode fine pitch 3D sensors are irradiated up to such fluence bump-bonded to a fine pitch ASIC. The preliminary analysis of the collected data shows no degradation on the hit detection efficiencies of the tested sensors after high energy proton irradiation, demonstrating the excellent radiation tolerance of the 3D pixel sensors. Thus, they will be excellent candidates for the extreme radiation environment at the innermost layers of the HL-LHC experiments.Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of Instrumentation, February 18-22, 2019, Vienna, Austria. arXiv admin note: text overlap with arXiv:1903.0196

Linear Accelerator Test Facility at LNF Conceptual Design Report

Test beam and irradiation facilities are the key enabling infrastructures for research in high energy physics (HEP) and astro-particles. In the last 11 years the Beam-Test Facility (BTF) of the DA{\Phi}NE accelerator complex in the Frascati laboratory has gained an important role in the European infrastructures devoted to the development and testing of particle detectors. At the same time the BTF operation has been largely shadowed, in terms of resources, by the running of the DA{\Phi}NE electron-positron collider. The present proposal is aimed at improving the present performance of the facility from two different points of view: extending the range of application for the LINAC beam extracted to the BTF lines, in particular in the (in some sense opposite) directions of hosting fundamental physics and providing electron irradiation also for industrial users; extending the life of the LINAC beyond or independently from its use as injector of the DA{\Phi}NE collider, as it is also a key element of the electron/positron beam facility. The main lines of these two developments can be identified as: consolidation of the LINAC infrastructure, in order to guarantee a stable operation in the longer term; upgrade of the LINAC energy, in order to increase the facility capability (especially for the almost unique extracted positron beam); doubling of the BTF beam-lines, in order to cope with the signicant increase of users due to the much wider range of applications.Comment: 71 page