Investigation of a Toy Model for Frustration in Abelian Lattice Gauge Theory

We introduce a lattice model with local U(1) gauge symmetry which incorporates explicit frustration in d >2. The form of the action is inspired from the loop expansion of the fermionic determinant in standard lattice QED. We study through numerical simulations the phase diagram of the model, revealing the existence of a frustrated (antiferromagnetic) phase for d=3 and d=4, once an appropriate order parameter is identified.Comment: 7 pages, 7 figure

LITTLE THINGS in 3D: robust determination of the circular velocity of dwarf irregular galaxies

Dwarf Irregular galaxies (dIrrs) are the smallest stellar systems with extended HI discs. The study of the kinematics of such discs is a powerful tool to estimate the total matter distribution at these very small scales. In this work, we study the HI kinematics of 17 galaxies extracted from the `Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey' (LITTLE THINGS). Our approach differs significantly from previous studies in that we directly fit 3D models (two spatial dimensions plus one spectral dimension) using the software $^\text{3D}$BAROLO, fully exploiting the information in the HI datacubes. For each galaxy we derive the geometric parameters of the HI disc (inclination and position angle), the radial distribution of the surface density, the velocity-dispersion ($\sigma_v$) profile and the rotation curve. The circular velocity (V$_{\text{c}}$), which traces directly the galactic potential, is then obtained by correcting the rotation curve for the asymmetric drift. As an initial application, we show that these dIrrs lie on a baryonic Tully-Fisher relation in excellent agreement with that seen on larger scales. The final products of this work are high-quality, ready-to-use kinematic data ($\textrm{V}_\textrm{c}$ and $\sigma_v$) that we make publicly available. These can be used to perform dynamical studies and improve our understanding of these low-mass galaxies.Comment: 36 pages, 28 figures, 2 tables. Submitted to MNRAS (revised version after the referee report). The final rotation curves can be downloaded from http://www.filippofraternali.com/styled-9/index.htm

Global Value Chains During the Great Trade Collapse: A Bullwhip Effect?

This paper analyzes the performance of global value chains during the trade collapse. To do so, it exploits a unique transaction-level dataset on French firms containing information on cross-border monthly transactions matched with data on worldwide intra-.rm linkages as defined by property rights (multinational business groups, hierarchies of firms). This newly assembled dataset allows us to distinguish firm-level transactions among two alternative organizational modes of global value chains: internalization of activities (intra- group trade/trade among related parties) or establishment of supply contracts (arm's length trade/trade among unrelated parties). After an overall assessment of the role of global value chains during the trade collapse, we document that intra-group trade in intermediates was characterized by a faster drop followed by a faster recovery than arm's length trade. Amplified fluctuations in terms of trade elasticities by value chains have been referred to as the "bullwhip effect" and have been attributed to the adjustment of inventories within supply chains. In this paper we first con.rm the existence of such an effect due to trade in inter- mediates, and we underline the role that different organizational modes can play in driving this adjustment.trade collapse, multinational firms, global value chains, hierarchies of firms, vertical integration

Petrography, mineralogy and geochemistry of a primitive pumice from Stromboli: implications for the deep feeding system

We describe the field relations, petrographic, mineralogical and geochemical characteristics of an exceptional “golden” pumice belonging to a tephra layer exposed on the summit area of Stromboli volcano, Italy. Pumice sample PST-9 comes from a fallout deposit older than a spatter agglutinate sequence emplaced during the twentieth century. The eruption that produced it had a size exceeding that of intermediate paroxysms but was smaller than large-scale, spatter-forming, paroxysms from the sixteenth century and 1930 A.D. Lapilli are strongly vesicular and crystal-poor, similar to other “golden” pumices. Modal proportions include 89 vol% glass, 8 vol% clinopyroxene, 1–2 vol% olivine and 1–2 vol% plagioclase. Plagioclase is represented by reacted crystals coming from the shallow resident magma and incorporated in the pumice during eruption. A total of 74 and 44 crystals of olivine and clinopyroxene, respectively, were examined and 187 and 99 electron microprobe analyses obtained. Fo in olivine ranges between 70 and 92 mol% and Fs in clinopyroxene between 3 and 13 mol%. PST-9 hosts a higher proportion of Fo-rich olivine and Fs-poor clinopyroxene than the other “golden” pumices. Groundmass glasses are basaltic (Mg# = 66–69), as are most rim glasses around olivine and clinopyroxene, and glass inclusions in clinopyroxene. They are more primitive than in the other “golden” pumices. A few rim glasses and glass inclusions are shoshonitic (Mg# = 45–50). Most glass inclusions in olivine have CaO/Al2O3 higher than the other glasses and the whole-rock. PST-9 has the highest bulk MgO, CaO, Mg# and CaO/Al2O3 and the lowest FeOt of all “golden” pumices analysed to date. Analysis of Fe-Mg partitioning between olivine, clinopyroxene and melt allows three crystallization stages to be recognized. The first involves primitive mantle-derived melts (Mg# = 74–80), the second basaltic melts represented by groundmass glasses and the third is associated with more evolved melts represented by the shoshonitic glasses. The population of crystals in “golden” pumices is heterogeneous not only because of crystal incorporation from the shallow resident magma, but also because of pre-eruptive recharge of the deep reservoir with primitive melts. Differences between PST-9 and the other “golden” pumices in terms of groundmass glass composition and distribution of olivine and clinopyroxene compositions reflect contrasted replenishment rates of the deep reservoir with primitive liquids. Gabbroic inclusions in a clinopyroxene crystal provide a direct illustration of melt wall-rock interaction and stress the variability of the deep reservoir in terms of temperature, crystallinity and phase assemblages. Deep crystallization of plagioclase should be considered as a possibility at Stromboli. PST-9 is exceptionally well representative of the early magmatic evolution of “golden” pumices

Il costo sociale del morbillo in età pediatrica. L’epidemia a Palermo nel 1996-97

Objective To determine the direct and indirect costs associated with a measles epidemic occurring between September 1996 and August 1997 in Palermo (Italy) in paediatric-aged patients. Design A total of 2,029 cases of measles in a paediatric patient population were identified from a total of 38 paediatricians databases (24% of total). An extrapolation to the general population was then performed to estimate a total of 9,059 cases. Patient information obtained from the database such as patient age, risk factors, complications, vaccination history, as well as caretaker’s profession were included in a questionnaire compiled for each patient. Setting Inpatient and outpatient clinics in Palermo, Italy. Patients and participants Participants were paediatric-aged patients who had been diagnosed with measles. Included in the study was a group of previously vaccinated patients (6%). Main outcome measures and results The average cost of care was 464.000 Italian lire (Lit.) per case with a total cost of Lit. 4,2 billion for the entire epidemic. The direct costs comprehended 46.6% (Lit. 217.000 per case) of the total costs related to the measles epidemic and were subdivided according to in-patient care (55.4%), paediatric outpatient visits (33.5%) and drugs (9.7%). The average health-care cost associated to previously vaccinated patients (6%) was lower than for non-vaccinated patients, Lit. 110.000 vs Lit. 223.000 per case, respectively. Conclusion The demographic and economic data obtained highlights not only the social and economic impact of the epidemic, but also provides relevant information useful for cost-effectiveness analysis

Effects of final expenditures on ICT goods and services on the croatian domestic output and imports–the input- output approach

Information and Communication Technology (ICT) has a significant role in the growth and development of almost every national economy. The aim of this paper is to estimate the overall contribution of final expenditures on ICT goods and services on the domestic output and imports of Croatia in terms of gross value added (GVA) and employment. In order to quantify the direct, indirect and induced effects of final expenditures on ICT goods and services to the overall Croatian economy, input-output (IO) analysis is applied. The results of the empirical analysis show that of all three categories of total final uses, the final consumption expenditure on ICT goods and services recorded the highest total contribution in terms of GVA and in terms of employment. The final consumption expenditure of households had the most important role in generating GVA and employment, while the impact of government and non-profit organisations serving households expenditures was limited. At the activity section level, the majority of GVA and the number of jobs were generated in the activity section J–Information and Communication. The total number of employees induced by final expenditures on goods and services produced by the ICT sectors is estimated at 2.8%. The ICT sectors contributed to the total Croatian GVA in a range higher than 4.5

Heat Sensing Receptor TRPV1 Is a Mediator of Thermotaxis in Human Spermatozoa

The molecular bases of sperm thermotaxis, the temperature-oriented cell motility, are currently under investigation. Thermal perception relies on a subclass of the transient receptor potential [TRP] channels, whose member TRPV1 is acknowledged as the heat sensing receptor. Here we investigated the involvement of TRPV1 in human sperm thermotaxis. We obtained semen samples from 16 normozoospermic subjects attending an infertility survey programme, testis biopsies from 6 patients with testicular germ cell cancer and testis fine needle aspirates from 6 patients with obstructive azoospermia undergoing assisted reproductive technologies. Expression of TRPV1 mRNA was assessed by RT-PCR. Protein expression of TRPV1 was determined by western blot, flow cytometry and immunofluorescence. Sperm motility was assessed by Sperm Class Analyser. Acrosome reaction, apoptosis and intracellular-Ca2+ content were assessed by flow cytometry. We found that TRPV1 mRNA and protein were highly expressed in the testis, in both Sertoli cells and germ-line cells. Moreover, compared to no-gradient controls at 31°C or 37°C (Ctrl 31°C and Ctrl 37°C respectively), sperm migration towards a temperature gradient of 31-37°C (T gradient) in non-capacitated conditions selected a higher number of cells (14,9 ± 4,2×106 cells T gradient vs 5,1± 0,3×106 cells Ctrl 31°C and 5,71±0,74×106 cells Ctrl 37°C; P = 0,039). Capacitation amplified the migrating capability towards the T gradient. Sperms migrated towards the T gradient showed enriched levels of both TRPV1 protein and mRNA. In addition, sperm cells were able to migrate toward a gradient of capsaicin, a specific agonist of TRPV1, whilst capsazepine, a specific agonist of TRPV1, blocked this effect. Finally, capsazepine severely blunted migration towards T gradient without abolishing. These results suggest that TRPV1 may represent a facilitating mediator of sperm thermotaxis

An improved fault mitigation strategy for CUDA Fermi GPUs

High computation is a predominant requirement in many applications. In this field, Graphic Processing Units (GPUs) are more and more adopted. Low prices and high parallelism let GPUs be attractive, even in safety critical applications. Nonetheless, new methodologies must be studied and developed to increase the dependability of GPUs. This paper presents an improved fault mitigation strategy against permanent faults for CUDA Fermi GPUs. The proposed approach exploits the reverse engineering of the block scheduling policy in CUDA Fermi GPUs in order to minimize the fault mitigation timing overhead. The graceful performance degradation achieved by the proposed technique outperforms multithreaded CPU implementations and other fault mitigation strategies for CUDA GPU, even in presence of multiple permanent faults

Neurobiology of performance anxiety:A new approach

The aim of this study is to investigate the neurobiology of stress/emotionality, creating a multidisciplinary assessment model, which can help to provide psychological and physiological responses depending on the genetic background related to sport performances, social closeness and performance anxiety management in team sports. We enrolled 20 female volleyball players aged 13 \ub1 1 years old played in two different teams during a regional championship final. Saliva collection was carried out before and after the match. In order to evaluate the neuroendocrine effectors involved in stress and performance, we analyzed cortisol and progesterone levels through Elisa standard kit as well as HSP70 and amylase activity as stress-induced markers. As concern the psychometric assesment, we administrated he CSAI-2 test, Closeness Generating Procedure and STAI test. Genomic DNA was isolated from saliva cells using a QIAamp saliva kit according to the manufacturer\u2019s protocols. The SNP of the 5-HTTLPR, BDNF, DRD4 were analyzed. The results of the T-test performed on the total results showed a statistically significant relationship (p < 0.05) in cortisol levels pre and post match, as well between amylase and HP70 according to the genetic background. The analysis performed using just post match samples show a negative correlation between social closeness, cortisol and progesterone levels, with p < 0.010 for progesterone vs social closeness and p < 0.012 for cortisol vs social closeness. About the winner teams and the looser teams, there is a negative correlation between pre match cortisol levels and performance anxiety (p < 0.042)