807 research outputs found
Loop expansion around the Bethe approximation through the -layer construction
For every physical model defined on a generic graph or factor graph, the
Bethe -layer construction allows building a different model for which the
Bethe approximation is exact in the large limit and it coincides with the
original model for . The perturbative series is then expressed by a
diagrammatic loop expansion in terms of so-called fat-diagrams. Our motivation
is to study some important second-order phase transitions that do exist on the
Bethe lattice but are either qualitatively different or absent in the
corresponding fully connected case. In this case the standard approach based on
a perturbative expansion around the naive mean field theory (essentially a
fully connected model) fails. On physical grounds, we expect that when the
construction is applied to a lattice in finite dimension there is a small
region of the external parameters close to the Bethe critical point where
strong deviations from mean-field behavior will be observed. In this region,
the expansion for the corrections diverges and it can be the starting
point for determining the correct non-mean-field critical exponents using
renormalization group arguments. In the end, we will show that the critical
series for the generic observable can be expressed as a sum of Feynman diagrams
with the same numerical prefactors of field theories. However, the contribution
of a given diagram is not evaluated associating Gaussian propagators to its
lines as in field theories: one has to consider the graph as a portion of the
original lattice, replacing the internal lines with appropriate one-dimensional
chains, and attaching to the internal points the appropriate number of
infinite-size Bethe trees to restore the correct local connectivity of the
original model
Photonic technologies for non-invasive sexual identification: the case study of salamandrina perspicillata (amphibia, urodela)
Medium-Long-Term Radiographic and Clinical Outcomes after Surgical Treatment of Intra-Articular Tibial Pilon Fractures by Three Different Techniques
The goal of this retrospective, observational, case series study was to evaluate the medium-long-term clinical and radiographic results of the three most common surgical osteosynthesis techniques used for the treatment of articular tibial pilon fractures: ORIF, MIPO, and EF. Materials and Methods. A consecutive series of patients with articular pilon fractures who underwent surgery at our institution were enrolled in this study. Fractures were classified according to the M\ufcller AO classification system. Overall outcomes took the following into account: radiographic quality of reduction, evaluated using Ovadia and Beals\u2019 criteria; clinical assessment, evaluated using the AOFAS questionnaire; and general health, evaluated with the SF36-v2 Health Survey. Results. A total of 94 articular pilon fractures (34 type 43-B and 60 43-C) were evaluated with a mean follow-up of 56.34 months (range 33\u2013101). The techniques used were ORIF, MIPO, and EF in 63 (67%), 17 (18.9%), and 14 cases (14.1%), respectively. According to Ovadia and Beals\u2019 criteria, good, fair, and poor results were reported in 61 (64.89%), 26 (27.66%), and 7 (7.45%) cases, respectively. The mean AOFAS score was 82.41 for MIPO, 79.83 for ORIF, and 50.57 for EF, respectively. Thirty-nine patients (41.49%) presented early and/or late complications. Conclusion. Satisfactory outcomes using the three different techniques were reported. In particular, the radiographic outcomes were inversely proportional to the fracture comminutions and statistically different between internal and external osteosynthesis, but comparable between ORIF and MIPO techniques. On the other hand, the clinical outcomes were closely related to the soft tissue conditions and the anatomical reconstruction of the joint
Novel perspectives in redox biology and pathophysiology of failing myocytes: modulation of the intramyocardial redox milieu for therapeutic interventions - A review article from the Working Group of Cardiac Cell Biology, Italian Society of Cardiology
The prevalence of heart failure (HF) is still increasing worldwide, with enormous human, social, and economic costs, in spite of
huge efforts in understanding pathogeneticmechanisms and in developing effective therapies that have transformed this syndrome
into a chronic disease. Myocardial redox imbalance is a hallmark of this syndrome, since excessive reactive oxygen and nitrogen
species can behave as signaling molecules in the pathogenesis of hypertrophy and heart failure, leading to dysregulation of cellular
calcium handling, of the contractile machinery, of myocardial energetics and metabolism, and of extracellular matrix deposition.
Recently, following new interesting advances in understanding myocardial ROS and RNS signaling pathways, new promising
therapeutical approaches with antioxidant properties are being developed, keeping in mind that scavenging ROS and RNS tout
court is detrimental as well, since these molecules also play a role in physiological myocardial homeostasis
Archaeology and virtual acoustics. A pan flute from ancient Egypt
This paper presents the early developments of a recently started research project, aimed at studying from a multidisciplinary perspective an exceptionally well preserved ancient pan flute. A brief discussion of the history and
iconography of pan flutes is provided, with a focus on Classical Greece. Then a set of non-invasive analyses are presented, which are based on 3D scanning andmaterials chemistry, and are the starting point to inspect the geometry, construction, age and geographical origin of the instrument. Based on the available measurements, a preliminary analysis of the instrument tuning is provided, which is also informed with elements of theory of ancient Greek music. Finally, the paper presents current work aimed at realizing an interactive museum installation that recreates a virtual flute and allows intuitive access to all these research facets
Clustering data by inhomogeneous chaotic map lattices
A new approach to clustering, based on the physical properties of
inhomogeneous coupled chaotic maps, is presented. A chaotic map is assigned to
each data-point and short range couplings are introduced. The stationary regime
of the system corresponds to a macroscopic attractor independent of the initial
conditions. The mutual information between couples of maps serves to partition
the data set in clusters, without prior assumptions about the structure of the
underlying distribution of the data. Experiments on simulated and real data
sets show the effectiveness of the proposed algorithm.Comment: 8 pages, 6 figures. Revised version accepted for publication on
Physical Review Letter
Non-neural phenotype of spinal and bulbar muscular atrophy: Results from a large cohort of Italian patients
Objective: To carry out a deep characterisation of the main androgen-responsive tissues involved in spinal and bulbar muscular atrophy (SBMA). Methods: 73 consecutive Italian patients underwent a full clinical protocol including biochemical and hormonal analyses, genitourinary examination, bone metabolism and densitometry, cardiological evaluation and muscle pathology. Results: Creatine kinase levels were slightly to markedly elevated in almost all cases (68 of the 73; 94%). 30 (41%) patients had fasting glucose above the reference limit, and many patients had total cholesterol (40; 54.7%), low-density lipoproteins cholesterol (29; 39.7%) and triglyceride (35; 48%) levels above the recommended values. Although testosterone, luteinising hormone and follicle-stimulating hormone values were generally normal, in one-third of cases we calculated an increased Androgen Sensitivity Index reflecting the presence of androgen resistance in these patients. According to the International Prostate Symptom Score (IPSS), 7/70 (10%) patients reported severe lower urinal tract symptoms (IPSS score >19), and 21/73 (30%) patients were moderately symptomatic (IPSS score from 8 to 19). In addition, 3 patients were carriers of an indwelling bladder catheter. Videourodynamic evaluation indicated that 4 of the 7 patients reporting severe urinary symptoms had an overt prostate-unrelated bladder outlet obstruction. Dual-energy X-ray absorptiometry scan data were consistent with low bone mass in 25/61 (41%) patients. Low bone mass was more frequent at the femoral than at the lumbar level. Skeletal muscle biopsy was carried out in 20 patients and myogenic changes in addition to the neurogenic atrophy were mostly observed. Conclusions: Our study provides evidence of a wide non-neural clinical phenotype in SBMA, suggesting the need for comprehensive multidisciplinary protocols for these patients. \ua9 2016 Published by the BMJ Publishing Group Limited
INFUSION PRESSURE CONTROL SYSTEM
An infusion pressure control system for ophthalmic surgery includes: - intraocular pressure detection means; - arterial pressure detection means; and a control unit operatively connected to said intraocular pressure detection means and said arterial pressure detection means and configured for calculating the mean ocular perfusion pressure value based on the intraocular pressure and arterial pressure values provided by said intraocular pressure detection means and by said arterial pressure detection means, and for comparing said calculated mean ocular perfusion pressure value and at least one predetermined threshold value
La tradizione europea del pensiero economico
Spalletti \ue8 segretario organizzativo, membro del collegio dei docenti del dottorato e co-curatore della cotutela del titolo di dottorato con l'Universit\ue0 Sorbona di Parigi.
Lo scopo \ue8 formare studiosi con una preparazione adeguata alla complessit\ue0 che la ricerca nella Storia del pensiero economico ha raggiunto negli ultimi anni, conformemente anche con le nuove funzioni che la disciplina ha assunto nella formazione di economisti e scienziati sociali. La Storia del pensiero economico svolge infatti il ruolo di riflessione critica sui fondamenti della teoria economica; di riconoscimento dell\u2019influenza esercitata dall'evoluzione delle altre scienze; di approfondimento della teoria che nasce dall\u2019inquadramento del contesto culturale e storico che l\u2019ha determinata. In altre parole, la Storia del pensiero contribuisce a mantenere viva la tradizione europea di considerare la scienza economica come una scienza sociale. Tuttavia i corsi di laurea attuali non sono in grado di fornire un\u2019adeguata preparazione alla ricerca \u2013 ed eventualmente all\u2019insegnamento universitario \u2013 in questo settore. La materia richiede sia la conoscenza della teoria economica contemporanea (non fornita dai corsi di laurea propriamente umanistici) sia un\u2019adeguata preparazione alla ricerca storica (non fornita dai corsi di laurea in economia). Studi recenti hanno messo in evidenza i limiti di un approccio alla Storia del Pensiero economico confinato alla tradizione nazionale (considerata come un\u2019esperienza isolata poich\ue9 sovente gli Italiani studiano gli economisti italiani, i Tedeschi studiano gli economisti tedeschi etc.) ovvero alla tradizione anglosassone dominante. Ci\uf2 ha fatto passare in secondo piano interessanti correnti di pensiero che hanno avuto meno fortuna, o che sono legate a realt\ue0 nazionali diverse. La diffusione delle idee economiche tra i Paesi europei e la ricostruzione delle reti internazionali di
collaborazione e di influenze costituiscono i campi di ricerca pi\uf9 innovativi e interessanti e sono ancora quasi interamente da esplorare. In particolare i rapporti tra Germania, Francia, Spagna e Italia sono tutti da ricostruire. Occorre, dunque, essere pronti ad accogliere le indicazioni provenienti dalla Comunit\ue0 scientifica internazionale, che gi\ue0 da tempo ha cominciato a interrogarsi sui meccanismi di trasferimento delle idee economiche attraverso i confini nazionali. Proprio l'istituzione scientifica pi\uf9 autorevole in materia, la Societ\ue0 Europea per la Storia del pensiero economico (ESHET), ha organizzato nel 1999 il convegno: "National Traditions in Economic Thought and the Diffusion of Ideas". Si tratta di filoni di ricerca che richiedono una complessa preparazione (disciplinare e linguistica) per essere adeguatamente affrontati. Non esistono dottorati in Europa che abbiano queste caratteristiche di apertura internazionale e di interdisciplinarit\ue0 tra economia e storia. In Italia i giovani studiosi/e che nutrono interesse in questo campo vi accedono generalmente tramite dottorati in economia e sono costretti ad acquisire faticosamente e isolatamente la strumentazione necessaria e a dedicare tempo e risorse ad approfondire conoscenze che non sono funzionali ai loro interessi di ricerca. Inoltre l\u2019alta specializzazione di questo dottorato, che ha quasi come solo sbocco professionale la ricerca, rende efficiente la scelta di concentrare gli sforzi tra diversi Paesi in un unico corso di studio a valenza internazionale
The ASTRO-H X-ray Observatory
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly
successful X-ray missions initiated by the Institute of Space and Astronautical
Science (ISAS). ASTRO-H will investigate the physics of the high-energy
universe via a suite of four instruments, covering a very wide energy range,
from 0.3 keV to 600 keV. These instruments include a high-resolution,
high-throughput spectrometer sensitive over 0.3-2 keV with high spectral
resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in
the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers
covering 5-80 keV, located in the focal plane of multilayer-coated, focusing
hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12
keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and
a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the
40-600 keV band. The simultaneous broad bandpass, coupled with high spectral
resolution, will enable the pursuit of a wide variety of important science
themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical
Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to
Gamma Ray
- …
