An Algorithmic Approach to Quantum Field Theory

The lattice formulation provides a way to regularize, define and compute the Path Integral in a Quantum Field Theory. In this paper we review the theoretical foundations and the most basic algorithms required to implement a typical lattice computation, including the Metropolis, the Gibbs sampling, the Minimal Residual, and the Stabilized Biconjugate inverters. The main emphasis is on gauge theories with fermions such as QCD. We also provide examples of typical results from lattice QCD computations for quantities of phenomenological interest.Comment: 44 pages, to be published in IJMP

Ruolo della chirurgia endovascolare nelle rotture aortiche del politraumatizzato con lesioni polidistrettuali di pertinenza chirurgica

Nel politraumatizzato con gravi lesioni polidistrettuali di interesse chirurgico il trattamento endovascolare (TEV) della rottura posttraumatica dell’ aorta toracica (RPAT) rappresenta oggi una valida alternativa terapeutica al trattamento chirurgico convenzionale. Nella nostra esperienza (ottobre 2001-novembre 2004) abbiamo osservato 5 casi di RPAT (3 rotture istmiche, 2 rotture aorta toracica discendente) in gravi politraumatizzati, tutti di sesso maschile, di età compresa fra i 23 ed i 42 anni (media 32,4), trattate con successo con TEV. Il Glasgow Coma Score (GCS) era compreso fra 5 e 13. Tutti i pazienti sono stati sottoposti, dopo adeguata stabilizzazione del quadro clinico-emodinamico, ad angio-TC total body al fine di valutare la lesione aortica ed identificare le altre lesioni associate. In 4 casi erano coinvolti più distretti corporei di pertinenza chirurgica (3 casi: trauma osseo, addominale e neurochirurgico; 1 caso: trauma osseo, addominale, neurochirurgico e toracico). Il TEV è stato eseguito sempre in sala operatoria previa arteriografia digitale. La durata media della procedura angio-radiologica è stata di 105 minuti (range 80 - 125). Non si è verificata nessuna complicanza né immediata né a distanza (follow-up = medio 24 mesi; range 12-36). In conclusione il TEV delle RPAT offre in pazienti ‘critici’ una valida opzione terapeutica alla chirurgia tradizionale in grado di stabilizzare il quadro clinico e trattare successivamente ‘in sicurezza’ le altre gravi lesioni chirurgiche associate

Hodgkin's disease presenting below the diaphragm. The experience of the Gruppo Italiano Studio Linfomi (GISL)

Background and Objective. Infradiaphragmatic Hodgkin\ub4s disease is rare, making up 5-12% of cases in clinical stages I and II; consequently, several questions concerning prognosis and treatment strategy remain to be answered. The aim of this study was to analyze the clinical and prognostic characteristics and outcome of his condition. Methods. A series of 282 patients with CS I-II Hodgkin\ub4s disease (HD) was investigated. In 31 patients the disease was confined below the diaphragm (BDHD), and in the remaining above the diaphragm (ADHD). The presenting features and outcomes were compared in the two groups. Results. The BDHD group was older (p < 0.0002), had a higher frequency of males (p < 0.08) and a different histological subtype group distribution (p < 0.0001). Stage II BDHD patients had a worse overall survival rate (OS) than stage II ADHD patients (68.8% vs 86.6% at 8 years, p < 0.01) if age is not considered; patients with more than 40 years of age, in fact, had the same survival rates as those with ADHD. BDHD patients with intra-abdominal disease alone had worse prognostic factors and OS (p = 0.12) than patients with inguinal-femoral nodes. Interpretation and Conclusions. Although BDHD patients present distinct features, they have the same OS and relapse-free survival rate as age-adjusted ADHD patients. According to our experience patients with stage I peripheral BDHD respond well to radiotherapy-based regimens. Those with stage II and or intra-abdominal disease are more challenging; chemotherapy or a combined therapy seem to be more suitable approaches for these patients

Gauge thresholds in the presence of oblique magnetic fluxes

We compute the one-loop partition function and analyze the conditions for tadpole cancellation in type I theories compactified on tori in the presence of internal oblique magnetic fields. We check open - closed string channel duality and discuss the effect of T-duality. We address the issue of the quantum consistency of the toroidal model with stabilized moduli recently proposed by Antoniadis and Maillard (AM). We then pass to describe the computation of one-loop threshold corrections to the gauge couplings in models of this kind. Finally we briefly comment on coupling unification and dilaton stabilization in phenomenologically more viable modelsComment: 34 pages, 2 figures; references added, major changes to the discussion of the model proposed by Antoniadis and Maillar

Long-term results from MOPPEBVCAD chemotherapy with optional limited radiotherapy in advanced Hodgkin's disease

The purpose was to verify the 5-year results of the MOPPEBVCAD chemotherapy regimen with limited radiotherapy in relation to the promising preliminary data. Mechlorethamine, vincristine, procarbazine, prednisone, epidoxorubicin, bleomycin, vinblastine, lomustine, melphalan, and vindesine were delivered according to a schedule derived through hybridization, intensification, and shortening of the corresponding alternating CAD/MOPP/ABV regimen. Radiotherapy was restricted to sites of bulky involvement or to areas that responded incompletely to chemotherapy. This multicenter, controlled, nonrandomized trial involved 145 eligible patients. Radiotherapy was administered to 47 patients, 46 of whom were in complete remission after chemotherapy. Remissions were complete in 137 patients (94%), partial in 4 (3%), and null in the remaining 4. Tumor-specific, overall, relapse-free, and failure-free survival at 5 years were 0.89, 0.86, 0.82, and 0.78, respectively. Hematologic toxicity was considerable, whereas nonhematologic side effects were fully acceptable. Most of the unfavorable prognostic factors lost their clinical weight. Only age and lymphocyte depletion histologic type were statistically correlated with major follow up endpoints; performance status and bone marrow involvement were subordinate to age. Seven patients developed a second cancer (including 3 myelodysplasias). MOPPEBVCAD with selected radiotherapy is a highly effective regimen in advanced Hodgkin\ub4s disease. Early and late toxicity are no more severe than what would be expected with other alternating or hybrid regimens. A comparison with ABVD, which is currently considered the standard regimen for advanced Hodgkin\ub4s disease, is needed

Pulsating Variable Stars in the Coma Berenices dwarf spheroidal galaxy

We present B, V, I time-series photometry of the Coma Berenices dwarf spheroidal galaxy, a faint Milky Way satellite, recently discovered by the Sloan Digital Sky Survey. We have obtained V, B-V and V, V-I color-magnitude diagrams that reach V~23.0-23.2 mag showing the galaxy turnoff at V~21.7 mag, and have performed the first study of the variable star population of this new Milky Way companion. Two RR Lyrae stars (a fundamental-mode -RRab- and a first overtone -RRc- pulsator) and a short period variable with period P=0.12468 days were identified in the galaxy. The RRab star has a rather long period of P_ab=0.66971 days and is about 0.2 mag brighter than the RRc variable and other non-variable stars on the galaxy horizontal branch. In the period-amplitude diagram the RRab variable falls closer to the loci of Oosterhoff type-II systems and evolved fundamental-mode RR Lyrae stars in the Galactic globular cluster M3. The average apparent magnitude of the galaxy horizontal branch, =18.64+-0.04 mag, leads to a distance modulus for the Coma dSph mu_0=18.13+-0.08 mag, corresponding to a distance d=42^{+2}_{-1} kpc, by adopting a reddening E(B-V) = 0.045 +- 0.015 mag and a metallicity [Fe/H]=-2.53 +- 0.05 dex.Comment: 14 pages, 3 figures, Accepted for publication in ApJ

Wider implications of video-assisted thoracic surgery versus open approach for lung metastasectomy

Lung metastasectomy is considered a safe and potentially curative procedure despite there is not a strong evidence that metastasectomy prolongs long-term survival in patients with lung metastases. Moreover, the debate is open regarding the best approach for lung metastasectomy, video-assisted thoracic surgery versus open approach. A systematic review of literature to clarify what is the best approach to prolong survival in patients with lung metastases was performed. Our study confirms that overall survival is equivalent for video-assisted thoracic surgery and thoracotomy, therefore the ‘gold standard’ surgical treatment for lung metastases remains a point of debate. The choice of the surgical approach still depends more on the single center or surgeon practice than on strong scientific evidence. A prospective randomized trial could clarify the question

Prolonged survival in the absence of disease-recurrence in advanced-stage follicular lymphoma following chemo-immunotherapy: 13-year update of the prospective, multicenter randomized GITMO-IIL trial

Aprospective trial conducted in the period 2000-2005 showed no survival advantage for high-dose chemotherapy with rituximab and autograft (RHDS) versus conventional chemotherapy with rituximab (CHOP-R) as firstline therapy in 134 high-risk follicular lymphoma patients aged &lt;60 years. The study has been updated at the 13-year median follow up. As of February 2017, 88 (66%) patients were alive, with overall survival of 66.4% at 13 years, without a significant difference between R-HDS (64.5%) and CHOP-R (68.5%). To date, 46 patients have died, mainly because of disease progression (47.8% of all deaths), secondary malignancies (3 solid tumor, 9 myelodysplasia/acute leukemia; 26.1% of all deaths), and other toxicities (21.7% of all deaths). Complete remission was documented in 98 (73.1%) patients and associated with overall survival, with 13- year estimates of 77.0% and 36.8% for complete remission versus no-complete remission, respectively. Molecular remission was documented in 39 (65%) out of 60 evaluable patients and associated with improved survival. In multivariate analysis, complete remission achievement had the strongest effect on survival (P&lt;0.001), along with younger age (P=0.002) and female sex (P=0.013). Overall, 50 patients (37.3%) survived with no disease recurrence (18 CHOP-R, 32 R-HDS). This follow up is the longest reported on follicular lymphoma treated upfront with rituximab-chemotherapy and demonstrates an unprecedented improvement in survival compared to the pre-rituximab era, regardless of the use of intensified or conventional treatment. Complete remission was the most important factor for prolonged survival and a high proportion of patients had prolonged survival in their first remission, raising the issue of curability in follicular lymphoma