Positive solutions of Schr\"odinger equations and fine regularity of boundary points

Given a Lipschitz domain $\Omega$ in ${\mathbb R} ^N$ and a nonnegative potential $V$ in $\Omega$ such that $V(x)\, d(x,\partial \Omega)^2$ is bounded in $\Omega$ we study the fine regularity of boundary points with respect to the Schr\"odinger operator $L_V:= \Delta -V$ in $\Omega$. Using potential theoretic methods, several conditions equivalent to the fine regularity of $z \in \partial \Omega$ are established. The main result is a simple (explicit if $\Omega$ is smooth) necessary and sufficient condition involving the size of $V$ for $z$ to be finely regular. An essential intermediate result consists in a majorization of $\int_A | {\frac {u} {d(.,\partial \Omega)}} | ^2\, dx$ for $u$ positive harmonic in $\Omega$ and $A \subset \Omega$. Conditions for almost everywhere regularity in a subset $A$ of $\partial \Omega$ are also given as well as an extension of the main results to a notion of fine ${\mathcal L}_1 | {\mathcal L}_0$-regularity, if ${\mathcal L}_j={\mathcal L}-V_j$, $V_0,\, V_1$ being two potentials, with $V_0 \leq V_1$ and ${\mathcal L}$ a second order elliptic operator.Comment: version 1. 23 pages version 3. 28 pages. Mainly a typo in Theorem 1.1 is correcte

Non-equilibrium thermodynamic description of junctions in semiconductor devices

The methods of non-equilibrium thermodynamics of systems with an interface have been applied to the study of transport processes in semiconductor junctions. A complete phenomenological model for drift-diffusion processes in a junction has been derived, which includes, from first principles, both surface equations and boundary conditions, together with the usual drift-diffusion equations for the bulks. In this way a self-consistent characterisation of the whole system, bulks and interface, has been obtained in a common framework. The completeness of the model has been shown and a simple application to metal-semiconductor junctions developed.Comment: 12 pages, RevTex. Submitted to Phys. Rev. B minor LaTex errors correcte

Quantum and Classical Glass Transitions in LiHoxY1−xF4Li Ho_x Y_{1-x} F_4

When performed in the proper low field, low frequency limits, measurements of the dynamics and the nonlinear susceptibility in the model Ising magnet in transverse field, $\text{LiHo}_x\text{Y}_{1-x}\text{F}_4$, prove the existence of a spin glass transition for $x$ = 0.167 and 0.198. The classical behavior tracks for the two concentrations, but the behavior in the quantum regime at large transverse fields differs because of the competing effects of quantum entanglement and random fields.Comment: 5 pages, 5 figures. Updated figure 3 with corrected calibration information for thermometr

Leave-one-out prediction error of systolic arterial pressure time series under paced breathing

In this paper we show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. In particular we consider systolic arterial pressure time series from healthy subjects and Chronic Heart Failure patients, undergoing paced respiration. We model time series by the regularized least squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular, thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. The leave-one-out error separates controls from patients and, when all orders of nonlinearity are taken into account, alive patients from patients for which cardiac death occurred

Biomarkers of aging in HIV: inflammation and the microbiome

Purpose: HIV-infected subjects present increased levels of inflammatory cytokines and T cell activation in the peripheral blood despite suppressive combination antiretroviral therapy which renders them susceptible to premature aging. The purpose of the present work was to review existing evidence on the ways in which the anatomical and microbiological abnormalities of the gastrointestinal tract can represent a major cause of organ disease in HIV infection. Methods: We conducted a systematic review of the Pubmed database for articles published from 2014 to 2018. We included studies on inflammatory/activation biomarkers associated with cardiovascular and bone disease, neurocognitive impairment and serious non-AIDS events in HIV-infected subjects. We also included researches which linked peripheral inflammation/activation to the anatomical, immune and microbiological alterations of the gastrointestinal tract. Results: Recent literature data confirm the association between non-infectious comorbidities and inflammation in HIV infection which may be driven by gastrointestinal tract abnormalities, specifically microbial translocation and dysbiosis. Furthermore, there is mounting evidence on the possible role of metabolic functions of the microbiota in the pathogenesis of premature aging in the HIV-infected population. Conclusions: Biomarkers need to be validated for their use in the management of HIV infection. Compounds which counteract microbial translocation, inflammation and dysbiosis have been investigated as alternative therapeutic strategies in viro-suppressed HIV-infected individuals, but appear to have limited efficacy, probably due to the multifactorial pathogenesis of non-infectious comorbidities in this setting

ROLE OF CART ON GUT MICROBIAL DYSBIOSIS, STUDYING THE GUT/BLOOD MICROBIOTA DURING THE FIRST TWO YEARS OF SUPPRESSIVE CART

ROLE OF CART ON GUT MICROBIAL DYSBIOSIS, STUDYING THE GUT/BLOOD MICROBIOTA DURING THE FIRST TWO YEARS OF SUPPRESSIVE CART BACKGROUND Microbial dysbiosis features HIV+ individuals, both na\uefve and cART-treated, and is linked to anatomical/structural changes in the gastrointestinal (GI) tract, leading to microbial translocation (MT) and immune activation. Given that data on microbiota modifications during long-term therapy are lacking, we investigated gut/blood microbiota during the first 2 years of suppressive cART. METHODS We enrolled 138 HIV+ subjects. Plasma was collected at baseline (T0) and following 12 (T12) and 24 months (T24) of cART. CD8+ T-cell activation (CD38+; CD38+CD45R0+), MT (sCD14 and EndocAb) and GI damage (IFAB-P) were studied. In a sub-group of 41 patients (pts) we also evaluated GI permeability (urinary LAC/MAN test), inflammation (faecal calprotectin), 16SDNA (MT marker) and gut persistence score, metagenomic function analysis (Picrust) as well as peripheral and faecal microbiota (DNA extraction and 16S Metagenomic Sequencing; MiSeq Illumina\uae). For the microbiota analyses we enrolled 15 HIV- subjects as controls. All groups were analysed by Wilcoxon test, Kruskal-Wallis test and Permanova analysis. RESULTS 88% were male, 65% MSM, 6% HCV+; median age, CD4+ count, HIV RNA and duration of infection were respectively 38 years, 312/mmc, 5.03 log10cp/mL and 11.5 months. Following cART we registered a reduction of activated and activated/memory CD+8 T-cells (both with p<0.0001), an increase of EndoCab levels (p<0.0001) yet no significant changes in plasma sCD14. In contrast, an increase of I-FABP (p<0.0001) vis- \ue0 -vis a reduction of LAC/MAN test (p=0.03) and faecal calprotectin (p=0.01) were found. In faeces, cART resulted in a limited modification of the relative abundance of the microbiota, however differences between pts and controls were detected in the Firmicutes, Bacteroidetes and Actynobacteria phyla. Alpha-diversity showed higher richness in HIV+ vs controls (observed: p=0.006; Chao1: p=0.002) and these differences were maintained at T12 and T24. PCoA plot analyses showed a trend to the separation of pts and controls at all time-points yet the latter overlapped regardless of treatment status and length of cART. Lefse analyses (LDS >2.0) in HIV+ showed a significant increase of Veillonellaceae at T12 (p=0.007) and T24 (p=0.001) Desulfovibrionaceae at T24 (p=0.022) and Prevotellaceae at T24 (p=0.018). Further, many differences between pts and controls was detected in HIV+ . This persistent dysbiosis was associated with the continuous mucosal damage, despite cART introduction: I-FABP were positively correlated with Veillonellaceae both at T12 (r2=0.197; p=0.030;) and T24 (r2=0.156; p=0.017). Interestingly, when we stratified patients according to cART regimens, we found that only NNRTI-based therapy significantly reduced richness (observed: p=0.038; Chao1: p=0.006), but not evenness indexes over time. Furthermore, the relative abundance analyses showed a different profile at both family and genus levels, with NNRTI-based regimens significantly reducing the families of Coriobacteriaceae, Peptococcaceae and increasing the Veillonellaceae family. On the opposite, INSTI-based regimens resulted in decreased Peptococcaceae and increased Veillonellaceae families, as well as in higher Allisonella genus. No major effects following PI-based regimens were detected; no modifications about gut persistence score analysis as well as predicted functional metagenomic pathway analysis were found. Plasma microbiota analyses revealed no major changes of relative abundance parameters during cART and in comparison with uninfected controls. Decreased alpha-diversity was nonetheless found in HIV+ compared to controls (Shannon: p=0.02, Simpson: p=0.009) and persisted both at T12 and T24. CONCLUSIONS HIV-related modifications of the microbiota occur within the GI tract and not in the blood and are minimally affected by long-term effective cART, despite evidence of the containment of gut inflammation. These data suggest the ability of the virus to irreversibly impact the microbiological core of chronically-infected individuals

Micropropagation supports reintroduction of an apulian artichoke landrace in sustainable cropping systems

Artichoke (Cynara cardunculus L. var. scolymus (L.) Fiori) is a perennial plant of the Aster-aceae’s family native to the Mediterranean basin. Italy has rich artichoke biodiversity, but many landraces are subjected to genetic erosion caused by increasing use of commercial varieties that are more homogenous in production. An Apulian landrace ‘Troianella’ was established in vitro to valorize and provide high-quality material for propagation in nurseries and, subsequently, for cultivation in production fields. The shoot proliferation was tested on four different growth media, adding cytokinin (-6-benzylamminopurine (BAP-0.05 mg L−1 ). Among these, the best results were achieved on MS519-A and BM media in which MS macronutrients were supplemented with additional doses of CaCl2 and MgSO4 (plus 120 mg L−1 and 190 mg L−1, respectively). In vitro root induction was obtained with 10 mg L−1 of Indole-3-acetic acid (IAA) and 30 g L−1 of sucrose. Plants derived from tissue culture were acclimatized in greenhouse using mycorrhizal symbiosis to increase survival during the acclimatization phase and to improve their performance after transplanting in field. Three arbuscular mycorrhizal (AM) fungi (Septoglomus viscosum, Funelliformis mosseae, and Symbivit, a commercial mix) were added to a sterile substrate and compared to a sterile control without any AM fungal inocula. After 3 months, the best growth and plant appearance were on substrates with S. viscosum fungus or the commercial mycorrhizal fungi mix. The results supported a development of an efficient micropropagation protocol and a production of high quality plant material for sustainable farming of the endangered ’Troianella’ landrace

Role of surgical setting and patients-related factors in predicting the occurrence of postoperative pulmonary complications after abdominal surgery

OBJECTIVE: The aim of this retrospective study was to evaluate the role of surgical setting (urgent vs. elective) and approach (open vs. laparoscopic) in affecting postoperative pulmonary complications (PPCs) prevalence in patients undergoing abdominal surgery. PATIENTS AND METHODS: After local Ethical Committee approval, 409 patients who had undergone abdominal surgery between January and December 2014 were included in the final analysis. PPCs were defined as the development of one of the following new findings: respiratory failure, pulmonary infection, aspiration pneumonia, pleural effusion, pneumothorax, atelectasis on chest X-ray, bronchospasm or un-planned urgent re-intubation. RESULTS: PPCs prevalence was greater in urgent (33%) vs. elective setting (7%) (chi(2) with Yates correction: 44; p=0.0001) and in open (6%) vs. laparoscopic approach (1.9%) (chi(2) with Yates correction: 12; p=0.0006). PPCs occurrence was positively correlated with in-hospital mortality (Biserial Correlation r=0.37; p=0.0001). Logistic regression showed that urgent setting (p=0.000), Ariscat (Assess Respiratory Risk in Surgical Patients in Catalonia) score (p=0.004), and age (p=0.01) were predictors of PPCs. A cutoff of 23 for Ariscat score was also identified as determining factor for PPCs occurrence with 94% sensitivity and 29% specificity. CONCLUSIONS: Patients undergoing abdominal surgery in an urgent setting were exposed to a higher risk of PPCs compared to patients scheduled for elective procedures. Ariscat score fitted with PPCs prevalence and older patients were exposed to a higher risk of PPCs. Prospective studies are needed to confirm these result

Nonlinear hyperbolic systems: Non-degenerate flux, inner speed variation, and graph solutions

We study the Cauchy problem for general, nonlinear, strictly hyperbolic systems of partial differential equations in one space variable. First, we re-visit the construction of the solution to the Riemann problem and introduce the notion of a nondegenerate (ND) system. This is the optimal condition guaranteeing, as we show it, that the Riemann problem can be solved with finitely many waves, only; we establish that the ND condition is generic in the sense of Baire (for the Whitney topology), so that any system can be approached by a ND system. Second, we introduce the concept of inner speed variation and we derive new interaction estimates on wave speeds. Third, we design a wave front tracking scheme and establish its strong convergence to the entropy solution of the Cauchy problem; this provides a new existence proof as well as an approximation algorithm. As an application, we investigate the time-regularity of the graph solutions $(X,U)$ introduced by the second author, and propose a geometric version of our scheme; in turn, the spatial component $X$ of a graph solution can be chosen to be continuous in both time and space, while its component $U$ is continuous in space and has bounded variation in time.Comment: 74 page