Space-time coupling in the up-conversion of broadband down-converted light

We investigate the up-conversion process of broadband light from parametric down-conversion (PDC), focusing on the spatio-temporal spectral properties of the sum-frequency generated (SFG) radiation. We demonstrate that the incoherent component of the SFG spectrum is characterized by a skewed geometry in space-time, which originates from a compensation between the group-velocity mismatch and the spatial walk-off of the fundamental and the SFG fields. The results are illustrated both by a theoretical modeling of the optical system and by experimental measurements.Comment: 11 pages, 9 figures. arXiv admin note: text overlap with arXiv:1308.236

Time and position distributions in large volume spherical scintillation detectors

Large spherical scintillation detectors are playing an increasingly important role in experimental neutrino physics studies. From the instrumental point of view the primary signal response of these set-ups is constituted by the time and amplitude of the anode pulses delivered by each individual phototube following a particle interaction in the scintillator. In this work, under some approximate assumptions, we derive a number of analytical formulas able to give a fairly accurate description of the most important timing features of these detectors, intended to complement the more complete Monte Carlo studies normally used for a full modelling approach. The paper is completed with a mathematical description of the event position distributions which can be inferred, through some inference algorithm, starting from the primary time measures of the photomultiplier tubes.Comment: 29 pages, 20 figures, accepted for publication on Nucl. Instr. and Meth.

Towards better models of externalities in sponsored search auctions

Sponsored Search Auctions (SSAs) arguably represent the problem at the intersection of computer science and economics with the deepest applications in real life. Within the realm of SSAs, the study of the effects that showing one ad has on the other ads, a.k.a. externalities in economics, is of utmost importance and has so far attracted the attention of much research. However, even the basic question of modeling the problem has so far escaped a definitive answer. The popular cascade model is arguably too idealized to really describe the phenomenon yet it allows a good comprehension of the problem. Other models, instead, describe the setting more adequately but are too complex to permit a satisfactory theoretical analysis. In this work, we attempt to get the best of both approaches: firstly, we define a number of general mathematical formulations for the problem in the attempt to have a rich description of externalities in SSAs and, secondly, prove a host of results drawing a nearly complete picture about the computational complexity of the problem. We complement these approximability results with some considerations about mechanism design in our context

HGF/Met axis has anti-apoptotic and anti-autophagic function in hypoxic cardiac injury

Ischaemic heart disease is the main cause of death in western countries. Cardiac tissue is primarily damaged by cardiomyocyte cell death triggered by low oxygen supply to the heart (hypoxia). The current therapeutic approach is coronary angioplastic intervention or thrombolytic treatments to resume blood flow in the ischaemic heart. Unfortunately, reperfusion itself causes a burst of ROS production responsible for cardiomyocyte death and myocardial dysfunction. Indeed, the majority of patients surviving to acute myocardial infarction undergoes progressive heart failure, with 50% mortality at five years from diagnosis. Apoptosis of cardiomyocytes is dangerous both during ischaemia and reperfusion. In line with this concept, we have shown that treatment of H9c2 cardiomyoblasts with cobalt chloride (CoCl2), a chemical mimetic of hypoxia, induces caspase-dependent apoptosis. Unexpectedly, we found that 3-methyladenine, an inhibitor of autophagy initiation, partially prevents CoCl2-mediated cell death, indicating that also autophagy contributes to cardiomyoblast death. Consistently, we found an increase in the autophagic flux in dying cells. Mechanistically, we have shown that CoCl2 upregulates Redd1, Bnip3 and phospho-AMPK proteins and causes inhibition of mTOR, the main negative regulator of autophagy.  In light of these observations, it is important to discover new therapeutic tools displaying a dual prosurvival mechanism. To this aim, we have analyzed the cardioprotective action of HGF/Met axis in hypoxic injury. To activate Met signaling we have used either the HGF ligand or two different monoclonal antibodies (mAbs) directed against the extracellular moiety of Met receptor. Owing a divalent structure, the two mAbs can dimerize and activate Met receptor, thus displaying agonist activity. Hypoxic injury was fully prevented by either HGF or Met agonist mAbs through both anti-apoptotic and anti-autophagic functions. By pharmacological inhibition we showed that activation of mTOR is the protective signaling downstream to Met, being involved in the anti-autophagic effect. In conclusion, HGF or Met agonist mAbs promote cell survival by negative dual regulation of apoptotic and autophagic cell death and represent promising new therapeutic tools to manage cardiac diseases

Research Progress on Homogeneous Fabrication of Large-Area Perovskite Films by Spray Coating

The bottleneck for large-scale processing within perovskite solar cells (PSCs) development is the stringent need for uniform thin films. On a lab scale, the spin coating methodology with acceptable uncertainty ensures a high level of uniformity with minimal roughness, no voids, and reproducible procedures. However, the technique is strongly limited for up-scaling because the uncertainty is out of range from the spin center to the edge, resulting in areas only up to a few cm2. In order to boost the industrialization of PSCs, the spray coating (SC) methodology can represent a good solution for achieving the goal of uniformity (in terms of crystal size, film thickness, and roughness) that, combined to a reduced active materials waste, compatible to roll2roll production line, will pave the way to PSCs mass production. In this critical review, we present the technological features of SC relevant to PSCs development and critically discuss the key points on which to address the focus for achieving optimal and reliable performances in connection with the fundamental higher potential of SC over spin-coating in allowing to control thin film homogeneity. This review can help in the commercialization of perovskite solar cells but also can contribute to the development of scale-up methodologies

Liver Injury with Nintedanib: A Pharmacovigilance-Pharmacokinetic Appraisal

Drug-induced liver injury (DILI) with nintedanib has emerged as an adverse event of special interest in premarketing clinical trials. We characterized DILI with nintedanib in the real world and explored the underlying pharmacological basis. First, we assessed serious hepatic events reported to the Food and Drug Administration's Adverse Event Reporting System by combining the disproportionality approach [reporting odds ratio (ROR) with 95% confidence interval (CI)] with individual case assessment. Demographic and clinical features were inspected (seriousness, onset, discontinuation, dechallenge/rechallenge, concomitant drugs) to implement an ad hoc causality assessment scoring system. Second, we appraised physiochemical and pharmacokinetic parameters possibly predictive of DILI occurrence. Significant disproportionality was found for nintedanib as compared to pirfenidone (N = 91; ROR = 4.77; 95% CI = 3.15-7.39). Asian population, low body weight (59 kg), and rapid DILI onset (13.5 days) emerged as clinical features. Hospitalization and discontinuation were found in a significant proportion of cases (32% and 36%, respectively). In 24% of the cases, at least two potentially hepatotoxic drugs (statins, proton pump inhibitors, antibiotics) were recorded. Causality was at least possible in 92.3% of the cases. High lipophilicity and predicted in silico inhibition of liver transporters emerged as potential pharmacokinetic features supporting the biological plausibility. Although causality cannot be demonstrated, clinicians should consider early monitoring and medication review on a case-by-case basis

Effects of a glucooligosaccharide supplement on the morphological characteristics of the gastro-intestinal tract and growth performance in weaned piglets

This study was designed to evaluate the effects of a gluco-oligosaccharide (GOS), as an alternative to growth promoters in piglets, on: growth performance, blood parameters and morphological characteristics of the intestinal tract. Four week old weaned piglets (n=128) (7.2 ± 1.04 kg l.w.) were divided into four groups and fed for 77 days on different diets as follows: 1.- Basal diet (CTR); 2.- Basal diet supplemented with a 2% GOS; 3.- Basal diet supplemented with chlortetracycline and spiramicine at 1000 and 400 mg/ kg, respectively, for 14 days and then fed the CTR basal diet (CTRM); or 4.-a GOS diet supplemented and administered as in group 3 (GOSM). Animals were individually weighed 5 times, on days 0, 14, 35, 56 and 77. At the same time, the feed intake and average daily gains (ADG) were recorded and the feed conversion ratio (FCR) was calculated. On days 0 and 77, plasma was sampled from 6 piglets/treatment group, whereas on 77th day, 4 piglets/treatment were slaughtered to assess the morphological characteristics of parts of their gastro-intestinal tracts (ileum and caecum). The results showed no effects of the medications on the ADG in all the experimental periods. However, from days 57 to 77 of the trial period, the ADG was found to be higher in the GOS-fed animals (P=0.0747). During the first 14 days of the trial, the piglets on the medicated diets showed a higher intake than the animals in the normal diet groups, but no differences were detectable in the FCR. The globulin concentration and the albumin/globulin ratio was found to be reduced by GOS treatment (P <0.01). The urea concentration in the blood was decreased (P<0.05), whereas the plasma concentration of phosphorous was increased (P<0.01), by GOS supplementation. We found that the heights of the villi in the ileum was higher in the piglets on the GOSM diet compared to CTRM diet: (188.66 mm vs 255.74 mm; P<0.01). We also observed that supplementing these diets with GOS lead to a higher caecum epithelial cell height (11.7 μm vs 14.7 μm; P 0.068) compared with animals on the non-supplemented diets. Our current data indicate that the growth performance did not differ between piglets fed on control, antibiotic- supplemented or GOS-supplemented diets. A dietary supplementation of GOS does increase the villus length, but only in animals previously fed with medicated feeds. The use of GOS seems to exert anti-inflammatory effects upon these animals