Phase separation and pairing regimes in the one-dimensional asymmetric Hubbard model

We address some open questions regarding the phase diagram of the one-dimensional Hubbard model with asymmetric hopping coefficients and balanced species. In the attractive regime we present a numerical study of the passage from on-site pairing dominant correlations at small asymmetries to charge-density waves in the region with markedly different hopping coefficients. In the repulsive regime we exploit two analytical treatments in the strong- and weak-coupling regimes in order to locate the onset of phase separation at small and large asymmetries respectively.Comment: 13 pages, RevTeX 4, 12 eps figures, some additional refs. with respect to v1 and citation errors fixe

Ultrasound as first line step in anaemia diagnostics

This review covers the role of ultrasonography as an essential non-invasive diagnostic approach when facing patients with anaemia, a common clinical problem. Abdomen ultrasound is well recognised as a first-line examination in the setting of blood loss, both acute and chronic. Less is clear about the additional opportunities, given by ultrasound in anaemia, due to the many other possible causes. Here we provide information on the utility of ultrasound in different contexts and a practical guide for clinicians facing anaemic patients

Treatment of squamous cell carcinoma of the anal canal: A new strategies with anti-EGFR therapy and immunotherapy

The incidence of squamous cell carcinoma of the anal canal (SCAC) is increasing in both sexes but the standard treatment remains that of 20 years ago. However, interesting data have recently emerged on the use of anti-epidermal growth factor receptor (EGFR) agents and immunotherapy in advanced disease. Thus, new avenues of research are opening up that will hopefully lead to more effective therapeutic strategies. We provide an overview of the latest studies published on this tumor and discuss the possible future therapeutic options for combination therapy, anti-EGFR treatment and radiotherapy

A bizarre foreign body in the appendix: A case report

Foreign bodies are rare causes of appendicitis and, in most cases, ingested foreign bodies pass through the alimentary tract asymptomatically. However, ingested foreign bodies may sometimes remain silent within the appendix for many years without an inflammatory response. Despite the fact that cases of foreign-body-induced appendicitis have been documented, sharp and pointed objects are more likely to cause perforations and abscesses, and present more rapidly after ingestion. Various materials, such as needles and drill bits, as well as organic matter, such as seeds, have been implicated as causes of acute appendicitis. Clinical presentation can vary from hours to years. Blunt foreign bodies are more likely to remain dormant for longer periods and cause appendicitis through obstruction of the appendiceal lumen. We herein describe a patient presenting with a foreign body in his appendix which had been swallowed 15 years previously. The contrast between the large size of the foreign body, the long clinical history without symptoms and the total absence of any histological inflammation was notable. We suggest that an elective laparoscopic appendectomy should be offered to such patients as a possible management optio

A Methodology and Simulation-Based Toolchain for Estimating Deployment Performance of Smart Collective Services at the Edge

Research trends are pushing artificial intelligence (AI) across the Internet of Things (IoT)-edge-fog-cloud continuum to enable effective data analytics, decision making, as well as the efficient use of resources for QoS targets. Approaches for collective adaptive systems (CASs) engineering, such as aggregate computing, provide declarative programming models and tools for dealing with the uncertainty and the complexity that may arise from scale, heterogeneity, and dynamicity. Crucially, aggregate computing architecture allows for 'pulverization': applications can be decomposed into many deployable micromodules that can be spread across the ICT infrastructure, thus allowing multiple potential deployment configurations for the same application logic. This article studies the deployment architecture of aggregate-based edge services and its implications in terms of performance and cost. The goal is to provide methodological guidelines and a model-based toolchain for the generation and simulation-based evaluation of potential deployments. First, we address this subject methodologically by proposing an approach based on deployment code generators and a simulation phase whose obtained solutions are assessed with respect to their performance and costs. We then tailor this approach to aggregate computing applications deployed onto an IoT-edge-fog-cloud infrastructure, and we develop a corresponding toolchain based on Protelis and EdgeCloudSim. Finally, we evaluate the approach and tools through a case study of edge multimedia streaming, where the edge ecosystem exhibits intelligence by self-organizing into clusters to promote load balancing in large-scale dynamic settings

Robust Online Magnet Demagnetization Diagnosis in Asymmetrical Six-Phase AC Permanent Magnet Motor Drives

Rotor magnets are critical components, which in case of fault, directly affect the performance of drives based on permanent magnet synchronous motors. Thus, monitoring the rotor magnets status is essential to ensure both high level of efficiency and service continuity. The present study focuses on the investigation of a new full-time domain-based method for the diagnosis of incipient rotor magnet demagnetization in a vector-controlled asymmetrical six-phase surface-mounted ac permanent magnet synchronous motor. The proposed strategy evaluates the rotor magnet demagnetization using a fault index derived from the control signals synthetized in the 5th subspace, and already available in the control system platform. The main advantages of the proposed new strategy are its simplicity of implementation, and effectiveness even under time-varying operating conditions as the employed control signals in specific subspaces have a dc behavior. Extensive numerical simulations and experimental tests, carried out at different speed and load levels, have shown the validity of the proposed method, leading to an effective diagnostic procedure for a vector-controlled asymmetrical six-phase surface-mounted ac PMSM

Laparoscopic distal pancreatectomy in Italy: A systematic review and meta-analysis

Background The use of laparoscopic distal pancreatectomy (LDP) increased in the past twenty years but the real diffusion of this technique is still unknown as well as the type of centers (high or low volume) in which this procedure is more frequently performed. Data Source A systematic review was performed to evaluate the frequency of LDP in Italy and to compare indications and results in high volume centers (HVCs) and in low volume centers (LVCs). Results From 95 potentially relevant citations identified, only 5 studies were included. A total of 125 subjects were analyzed, of whom 95 (76.0%) were from HVCs and 30 (24.0%) from LVCs. The mean number of LDPs performed per year was 6.5. The mean number of patients who underwent LDP per year was 8.8 in HVCs and 3.0 in LVCs (P<0.001). The most frequent lesions operated on in HVCs were cystic tumors (62.1%, P<0.001) while, in LVCs, solid neoplasms (76.7%, P<0.001). In HVCs, malignant neoplasms were treated with LDP less frequently than in LVCs (17.9% vs 50.0%, P<0.001). Splenectomy was performed for non-oncologic reason frequenter in HVCs than in LVCs (70.2% vs 25.0%, P=0.004). The length of stay was shorter in HVCs than in LVCs (7.5 vs 11.3, P<0.001). No differences were found regarding age, gender, ductal adenocarcinoma treated, operative time, conversion, morbidity, postoperative pancreatic fistula, reoperation and margin status. Conclusions LDPs were frequently performed in Italy. The "HVC approach" is characterized by a careful selection of patients undergoing LDP. The "LVC approach" is based on the hypothesis that LDPs are equivalent both in short-term and long-term results to laparotomic approach. These data are not conclusive and they point out the need for a national register of laparoscopic pancreatectomy

The prognostic role of hemoglobin levels in patients undergoing concurrent chemo-radiation for anal cancer

Background: Concurrent chemo-radiation (CT-RT) is a standard therapy for squamous cell carcinoma of anal canal. Different clinical and biological factors may potentially affect outcome. We investigated the prognostic role of baseline hemoglobin (Hb) in a cohort of anal cancer patients submitted to CT-RT with 5-fluorouracil and mitomycin C. Methods: Up to 161 patients with clinical stage T1-T4/N0-N3/M0 were treated. Response was assessed at 6 weeks and thereafter at 3, 6 and 12 months. Two different approaches were used:a)simultaneous integrated boost following RTOG 05-29 indications;b)first sequence of 45Gy/25 fractions to the pelvis followed by 9-14.4 Gy/5-8 fractions to the macroscopic disease. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Results: On multivariate analysis, pre-treatment Hb level had a significant correlation to OS (HR:0.53;95% CI:0.33-0.87; p = 0.001), but not to PFS (HR:0.78;95% CI:0.53-1.15; p = 0.12) Patients with pre-treatment Hb ≥ 12 g/dl had 5-year PFS and OS of 82.2%, compared to 29.3% and 32.8% for those below the threshold. The likelihood to achieve a complete remission increased by 5.6% for every single-unit (g/dl) increase in baseline Hb level over 11 g/dl. On multivariate analysis, response to treatment had a significant correlation to PFS (incomplete vs complete response - HR:5.43;95% CI:2.75-10.7; p < 0.0001) and OS (HR: 6.96;95% CI:2.96-16.5; p < 0.0001). Conclusions: We showed that baseline Hb level is a strong indicator for poor response to RT-CT in anal cancer patients. A close clinical monitoring for incomplete response to treatment should be advised in patients with low pre-treatment Hb. The hypothesis that the preservation of adequate Hb level during treatment may lead to a better outcome needs prospective evaluation

The AMS-02 Time of Flight System. Final Design

The AMS-02 detector is a superconducting magnetic spectrometer that will operate on the International Space Station. The time of flight (TOF) system of AMS-02 is composed by four scintillator planes with 8, 8, 10, 8 counters each, read at both ends by a total of 144 phototubes. This paper describes the new design, the expected performances, and shows preliminary results of the ion beam test carried on at CERN on October 2002.Comment: 4 pages, 6 EPS figures. Proc. of the 28th ICRC (2003