Comparison of multiple-input single-output single-user ultra-wideband systems with pre-distortion

This paper presents a performance analysis of a baseband multiple-input single-output ultra-wideband system over scenarios CM1 and CM3 of the IEEE 802.15.3a channel model, incorporating four different schemes of pre-distortion: time reversal, zero-forcing pre-equaliser, constrained least squares pre-equaliser, and minimum mean square error pre-equaliser. For the third case, a simple solution based on the steepest-descent (gradient) algorithm is adopted and compared with theoretical results. The channel estimations at the transmitter are assumed to be truncated and noisy. Results show that the constrained least squares algorithm has a good trade-off between intersymbol interference reduction and signal-to-noise ratio preservation, providing a performance comparable to the minimum mean square error method but with lower computational complexity. Copyright (C) 2011 John Wiley & Sons, Ltd.Brazilian agency National Council for Scientific Technological Development (CNPq)Brazilian agency National Council for Scientific Technological Development (CNPq) [303426/2009-8

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Multicarrier CDMA systems.

Os sistemas CDMA multiportadora estão sendo considerados como fortes candidatos a integrar um dos padrões de telefonia móvel digital de quarta geração, principalmente por serem relativamente robustos aos efeitos nocivos de um canal de comunicação móvel com altas taxas de transmissão. O presente trabalho traz um estudo comparativo em termos de desempenho de três desses sistemas: MC-CDMA, MC DS-CDMA ortogonal e MT-CDMA. Os resultados aqui apresentados são obtidos analiticamente a partir de desenvolvimentos encontrados na literatura e também via simulação computacional Monte Carlo. Dentre os sistemas analisados, o MC-CDMA é o que apresentou um melhor resultado em termos de probabilidade de erro de bit. Entretanto, tal conclusão se restringe às configurações utilizadas e às simplificações adotadas para a obtenção das figuras de mérito dos sistemas.Multicarrier CDMA systems have been considered as good candidates to integrate one of the fourth generation wireless mobile communications standards, mainly because they are relatively robust to the degrading effects of a mobile communication channel with high transmission rates. The present work brings a comparative performance study of three multicarrier CDMA systems: MC-CDMA, MC DS-CDMA orthogonal and MT-CDMA. The results presented here are obtained analytically according to some developments found in the literature and also by Monte Carlo simulation. The MC-CDMA system had the best result in terms of bit error rate. However, it is important to point out that such conclusion limits to the configurations used and the simplifications adopted to obtain the systems performance

Constrained least square pre-distortion scheme for multiuser ultra-wideband

The study proposes a constrained least square (CLS) pre-distortion scheme for multiple-input single-output (MISO) multiple access ultra-wideband (UWB) systems. In such a scheme, a simple objective function is defined, which can be efficiently solved by a gradient-based algorithm. For the performance evaluation, scenarios CM1 and CM3 of the IEEE 802.15.3a channel model are considered. Results show that the CLS algorithm has a fast convergence and a good trade-off between intersymbol interference (ISI) and multiple access interference (MAI) reduction and signal-to-noise ratio (SNR) preservation, performing better than time-reversal (TR) pre-distortion

Performance analysis of a single-user MISO ultra-wideband time reversal system with DFE

This paper presents an analysis of the performance of a baseband multiple-input single-output (MISO) time reversal ultra-wideband system (TR-UWB) incorporating a symbol spaced decision feedback equalizer (DFE). A semi-analytical performance analysis based on a Gaussian approach is considered, which matched well with simulation results, even for the DFE case. The channel model adopted is based on the IEEE 802.15.3a model, considering correlated shadowing across antenna elements. In order to provide a more realistic analysis, channel estimation errors are considered for the design of the TR filter. A guideline for the choice of equalizer length is provided. The results show that the system`s performance improves with an increase in the number of transmit antennas and when a symbol spaced equalizer is used with a relatively small number of taps compared to the number of resolvable paths in the channel impulse response. Moreover, it is possible to conclude that due to the time reversal scheme, the error propagation in the DFE does not play a role in the system`s performance

S/MIMO MC-CDMA Heuristic Multiuser Detectors Based on Single-Objective Optimization

This paper analyzes the complexity-performance trade-off of several heuristic near-optimum multiuser detection (MuD) approaches applied to the uplink of synchronous single/multiple-input multiple-output multicarrier code division multiple access (S/MIMO MC-CDMA) systems. Genetic algorithm (GA), short term tabu search (STTS) and reactive tabu search (RTS), simulated annealing (SA), particle swarm optimization (PSO), and 1-opt local search (1-LS) heuristic multiuser detection algorithms (Heur-MuDs) are analyzed in details, using a single-objective antenna-diversity-aided optimization approach. Monte- Carlo simulations show that, after convergence, the performances reached by all near-optimum Heur-MuDs are similar. However, the computational complexities may differ substantially, depending on the system operation conditions. Their complexities are carefully analyzed in order to obtain a general complexity-performance framework comparison and to show that unitary Hamming distance search MuD (uH-ds) approaches (1-LS, SA, RTS and STTS) reach the best convergence rates, and among them, the 1-LS-MuD provides the best trade-off between implementation complexity and bit error rate (BER) performance.Brazilian CAPES Agency[BEX0556/07-6

Hybrid heuristic-waterfilling game theory approach in MC-CDMA resource allocation

This paper discusses the power allocation with fixed rate constraint problem in multi-carrier code division multiple access (MC-CDMA) networks, that has been solved through game theoretic perspective by the use of an iterative water-filling algorithm (IWFA). The problem is analyzed under various interference density configurations, and its reliability is studied in terms of solution existence and uniqueness. Moreover, numerical results reveal the approach shortcoming, thus a new method combining swarm intelligence and IWFA is proposed to make practicable the use of game theoretic approaches in realistic MC-CDMA systems scenarios. The contribution of this paper is twofold: (i) provide a complete analysis for the existence and uniqueness of the game solution, from simple to more realist and complex interference scenarios; (ii) propose a hybrid power allocation optimization method combining swarm intelligence, game theory and IWFA. To corroborate the effectiveness of the proposed method, an outage probability analysis in realistic interference scenarios, and a complexity comparison with the classical IWFA are presented. (C) 2011 Elsevier B.V. All rights reserved.National Council for Scientific and Technological Development (CNPq) of BrazilNational Council for Scientific and Technological Development (CNPq) of Brazil [303426/2009-8

Correction to: Major adverse cardiovascular events in non-valvular atrial fibrillation with chronic obstructive pulmonary disease: the ARAPACIS study

none372In the original publication, one of the ARAPACIS collaborators Dr. “Leonardo Di Gennaro” name has been erroneously mentioned as “Leonardo De Gennaro”.noneRaparelli V.; Pastori D.; Pignataro S.F.; Vestri A.R.; Pignatelli P.; Cangemi R.; Proietti M.; Davi G.; Hiatt W.R.; Lip G.Y.H.; Corazza G.R.; Perticone F.; Violi F.; Basili S.; Alessandri C.; Serviddio G.; Palange P.; Greco E.; Bruno G.; Averna M.; Giammanco A.; Sposito P.; DeCristofaro R.; Carulli L.; DiGennaro L.; Pellegrini E.; Cominacini L.; Mozzini C.; Pasini A.F.; Sprovieri M.; Spagnuolo V.; Cerqua G.; Cerasola G.; Mule G.; Barbagallo M.; Lo Sciuto S.; Monteverde A.; Saitta A.; Lo Gullo A.; Malatino L.; Cilia C.; Terranova V.; Pisano M.; Pinto A.; DiRaimondo D.; Tuttolomondo A.; Conigliaro R.; Signorelli S.; DePalma D.; Galderisi M.; Cudemo G.; Galletti F.; Fazio V.; DeLuca N.; Meccariello A.; Caputo D.; DeDonato M.T.; Iannuzi A.; Bresciani A.; Giunta R.; Utili R.; Iorio V.; Adinolfi L.E.; Sellitto C.; Iuliano N.; Bellis P.; Tirelli P.; Sacerdoti D.; Vanni D.; Iuliano L.; Ciacciarelli M.; Pacelli A.; Palazzuoli A.; Cacciafesta M.; Gueli N.; Lo Iacono C.; Brusco S.; Verrusio W.; Nobili L.; Tarquinio N.; Pellegrini F.; Vincentelli G.M.; Ravallese F.; Santini C.; Letizia C.; Petramala L.; Zinnamosca L.; Minisola S.; Cilli M.; Colangelo L.; Falaschi P.; Martocchia A.; Pastore F.; Bertazzoni G.; Attalla El Halabieh E.; Paradiso M.; Lizzi E.M.; Timmi S.; Battisti P.; Cerci S.; Ciavolella M.; DiVeroli C.; Malci F.; DeCiocchis A.; Abate D.; Castellino P.; Zanoli L.; Fidone F.; Mannarino E.; Pasqualini L.; Oliverio G.; Pende A.; Artom N.; Ricchio R.; Fimognari F.L.; Alletto M.; Messina S.; Sesti G.; Arturi F.; Succurro E.; Fiorentino T.V.; Pedace E.; Scarpino P.E.; Carullo G.; Maio R.; Sciacqua A.; Frugiuele P.; Battaglia G.; Atzori S.; Delitala G.; Angelucci E.; Sestili S.; Traisci G.; DeFeudis L.; DiMichele D.; Fava A.; Balsano C.; DeCiantis P.; Desideri G.; Camerota A.; Mezzetti M.; Gresele P.; Vedovati C.; Fierro T.; Puccetti L.; Bertolotti M.; Mussi C.; Boddi M.; Savino A.; Contri S.; Degl'Innocenti G.; Saller A.; Fabris F.; Pesavento R.; Filippi L.; Vedovetto V.; Puato M.; Treleani M.; DeLuca E.; DeZaiacomo F.; Giantin V.; Semplicini A.; Minuz P.; Romano S.; Fantin F.; Manica A.; Stockner I.; Pattis P.; Gutmann B.; Catena C.; Colussi G.; Sechi L.A.; Annoni G.; Bruni A.A.; Castagna A.; Spinelli D.; Miceli E.; Padula D.; Schinco G.; Spreafico S.; Secchi B.; Vanoli M.; Casella G.; Pulixi E.A.; Sansone L.; Serra M.G.; Longo S.; Antonaci S.; Belfiore A.; Frualdo M.; Palasciano G.; Ricci L.; Ventrella F.; Bianco C.; Santovito D.; Cipollone F.; Nicolai S.; Salvati F.; Rini G.B.; Scozzari F.; Muiesan M.L.; Salvetti M.; Bazza A.; Picardi A.; Vespasiani-Gentilucci U.; DeVincentis A.; Cosio P.; Terzolo M.; Madaffari B.; Parasporo B.; Fenoglio L.; Bracco C.; Melchio R.; Gentili T.; Salvi A.; Nitti C.; Gabrielli A.; Martino G.P.; Capucci A.; Brambatti M.; Sparagna A.; Tirotta D.; Andreozzi P.; Ettorre E.; Viscogliosi G.; Servello A.; Musumeci M.; Delfino M.; Giorgi A.; Glorioso N.; Melis G.; Marras G.; Matta M.; Sacco A.; Stellitano E.; Scordo A.; Russo F.; Caruso A.A.; Porreca E.; Tana M.; Ferri C.; Cheli P.; Portincasa P.; Muscianisi G.; Giordani S.; Stanghellini V.; Sabba C.; Mancuso G.; Bartone M.; Calipari D.; Arcidiacono G.; Bellanuova I.; Ferraro M.; Marigliano G.; Cozzolino D.; Lampitella A.; Acri V.; Galasso D.; Mazzei F.; Buratti A.; Galasso S.; Porta M.; Brizzi M.F.; Fattorini A.; Sampietro F.; D'Angelo A.; Manfredini R.; Pala M.; Fabbian F.; Moroni C.; Valente L.; Lopreiato F.; Parente F.; Granata M.; Moia M.; Braham S.; Rossi M.; Pesce M.; Gentile A.; Catozzo V.; Baciarello G.; Cosimati A.; Ageno W.; Rancan E.; Guasti L.; Ciccaglioni A.; Negri S.; Polselli M.; Prisco D.; Marcucci R.; Ferro D.; Perri L.; Saliola M.; DelBen M.; Angelico F.; Baratta F.; Migliacci R.; Porciello G.; Corrao S.; Napoleone L.; Talerico G.; Amoroso D.; Romiti G.F.; Ruscio E.; Toriello F.; Sperduti N.; Todisco T.; DiTanna G.; Sacchetti M.L.; Puddu P.E.; Farcomeni A.; Anzaldi M.; Bazzini C.; Bianchi P.I.; Boari B.; Buonauro A.; Butta C.; Buzzetti E.; Calabria S.; Capeci W.; Caradio F.; Carleo P.; Carrabba M.D.; Castorani L.; Cecchetto L.; Cicco S.; Cimini C.; Colombo B.M.; De Giorgi A.; DeVuono S.; DelCorso L.; Denegri A.; DiGiosia P.; Durante Mangoni E.; Falsetti L.; Forgione A.; Giorgini P.; Grassi D.; Grembiale A.; Hijazi D.; Iamele L.; Lorusso G.; Marchese A.; Marra A.M.; Masala M.; Miceli G.; Montebianco Abenavoli L.; Murgia G.; Naccarato P.; Pattoneri P.; Perego F.; Pesce P.; Piano S.; Pinna M.; Pinto D.; Pretti V.; Pucci G.; Salinaro F.; Salzano A.; Santilli F.; Scarpini F.; Scicali R.; Sirico D.; Suppressa P.; Talia M.; Tassone E.J.; Torres D.; Vazzana N.; Vecchio C.R.; Vidili G.; Vitale F.; Zaccone V.Raparelli, V.; Pastori, D.; Pignataro, S. F.; Vestri, A. R.; Pignatelli, P.; Cangemi, R.; Proietti, M.; Davi, G.; Hiatt, W. R.; Lip, G. Y. H.; Corazza, G. R.; Perticone, F.; Violi, F.; Basili, S.; Alessandri, C.; Serviddio, G.; Palange, P.; Greco, E.; Bruno, G.; Averna, M.; Giammanco, A.; Sposito, P.; Decristofaro, R.; Carulli, L.; Digennaro, L.; Pellegrini, E.; Cominacini, L.; Mozzini, C.; Pasini, A. F.; Sprovieri, M.; Spagnuolo, V.; Cerqua, G.; Cerasola, G.; Mule, G.; Barbagallo, M.; Lo Sciuto, S.; Monteverde, A.; Saitta, A.; Lo Gullo, A.; Malatino, L.; Cilia, C.; Terranova, V.; Pisano, M.; Pinto, A.; Diraimondo, D.; Tuttolomondo, A.; Conigliaro, R.; Signorelli, S.; Depalma, D.; Galderisi, M.; Cudemo, G.; Galletti, F.; Fazio, V.; Deluca, N.; Meccariello, A.; Caputo, D.; Dedonato, M. T.; Iannuzi, A.; Bresciani, A.; Giunta, R.; Utili, R.; Iorio, V.; Adinolfi, L. E.; Sellitto, C.; Iuliano, N.; Bellis, P.; Tirelli, P.; Sacerdoti, D.; Vanni, D.; Iuliano, L.; Ciacciarelli, M.; Pacelli, A.; Palazzuoli, A.; Cacciafesta, M.; Gueli, N.; Lo Iacono, C.; Brusco, S.; Verrusio, W.; Nobili, L.; Tarquinio, N.; Pellegrini, F.; Vincentelli, G. M.; Ravallese, F.; Santini, C.; Letizia, C.; Petramala, L.; Zinnamosca, L.; Minisola, S.; Cilli, M.; Colangelo, L.; Falaschi, P.; Martocchia, A.; Pastore, F.; Bertazzoni, G.; Attalla El Halabieh, E.; Paradiso, M.; Lizzi, E. M.; Timmi, S.; Battisti, P.; Cerci, S.; Ciavolella, M.; Diveroli, C.; Malci, F.; Deciocchis, A.; Abate, D.; Castellino, P.; Zanoli, L.; Fidone, F.; Mannarino, E.; Pasqualini, L.; Oliverio, G.; Pende, A.; Artom, N.; Ricchio, R.; Fimognari, F. L.; Alletto, M.; Messina, S.; Sesti, G.; Arturi, F.; Succurro, E.; Fiorentino, T. V.; Pedace, E.; Scarpino, P. E.; Carullo, G.; Maio, R.; Sciacqua, A.; Frugiuele, P.; Battaglia, G.; Atzori, S.; Delitala, G.; Angelucci, E.; Sestili, S.; Traisci, G.; Defeudis, L.; Dimichele, D.; Fava, A.; Balsano, C.; Deciantis, P.; Desideri, G.; Camerota, A.; Mezzetti, M.; Gresele, P.; Vedovati, C.; Fierro, T.; Puccetti, L.; Bertolotti, M.; Mussi, C.; Boddi, M.; Savino, A.; Contri, S.; Degl'Innocenti, G.; Saller, A.; Fabris, F.; Pesavento, R.; Filippi, L.; Vedovetto, V.; Puato, M.; Treleani, M.; Deluca, E.; Dezaiacomo, F.; Giantin, V.; Semplicini, A.; Minuz, P.; Romano, S.; Fantin, F.; Manica, A.; Stockner, I.; Pattis, P.; Gutmann, B.; Catena, C.; Colussi, G.; Sechi, L. A.; Annoni, G.; Bruni, A. A.; Castagna, A.; Spinelli, D.; Miceli, E.; Padula, D.; Schinco, G.; Spreafico, S.; Secchi, B.; Vanoli, M.; Casella, G.; Pulixi, E. A.; Sansone, L.; Serra, M. G.; Longo, S.; Antonaci, S.; Belfiore, A.; Frualdo, M.; Palasciano, G.; Ricci, L.; Ventrella, F.; Bianco, C.; Santovito, D.; Cipollone, F.; Nicolai, S.; Salvati, F.; Rini, G. B.; Scozzari, F.; Muiesan, M. L.; Salvetti, M.; Bazza, A.; Picardi, A.; Vespasiani-Gentilucci, U.; Devincentis, A.; Cosio, P.; Terzolo, M.; Madaffari, B.; Parasporo, B.; Fenoglio, L.; Bracco, C.; Melchio, R.; Gentili, T.; Salvi, A.; Nitti, C.; Gabrielli, A.; Martino, G. P.; Capucci, A.; Brambatti, M.; Sparagna, A.; Tirotta, D.; Andreozzi, P.; Ettorre, E.; Viscogliosi, G.; Servello, A.; Musumeci, M.; Delfino, M.; Giorgi, A.; Glorioso, N.; Melis, G.; Marras, G.; Matta, M.; Sacco, A.; Stellitano, E.; Scordo, A.; Russo, F.; Caruso, A. A.; Porreca, E.; Tana, M.; Ferri, C.; Cheli, P.; Portincasa, P.; Muscianisi, G.; Giordani, S.; Stanghellini, V.; Sabba, C.; Mancuso, G.; Bartone, M.; Calipari, D.; Arcidiacono, G.; Bellanuova, I.; Ferraro, M.; Marigliano, G.; Cozzolino, D.; Lampitella, A.; Acri, V.; Galasso, D.; Mazzei, F.; Buratti, A.; Galasso, S.; Porta, M.; Brizzi, M. F.; Fattorini, A.; Sampietro, F.; D'Angelo, A.; Manfredini, R.; Pala, M.; Fabbian, F.; Moroni, C.; Valente, L.; Lopreiato, F.; Parente, F.; Granata, M.; Moia, M.; Braham, S.; Rossi, M.; Pesce, M.; Gentile, A.; Catozzo, V.; Baciarello, G.; Cosimati, A.; Ageno, W.; Rancan, E.; Guasti, L.; Ciccaglioni, A.; Negri, S.; Polselli, M.; Prisco, D.; Marcucci, R.; Ferro, D.; Perri, L.; Saliola, M.; Delben, M.; Angelico, F.; Baratta, F.; Migliacci, R.; Porciello, G.; Corrao, S.; Napoleone, L.; Talerico, G.; Amoroso, D.; Romiti, G. F.; Ruscio, E.; Toriello, F.; Sperduti, N.; Todisco, T.; Ditanna, G.; Sacchetti, M. L.; Puddu, P. E.; Farcomeni, A.; Anzaldi, M.; Bazzini, C.; Bianchi, P. I.; Boari, B.; Buonauro, A.; Butta, C.; Buzzetti, E.; Calabria, S.; Capeci, W.; Caradio, F.; Carleo, P.; Carrabba, M. D.; Castorani, L.; Cecchetto, L.; Cicco, S.; Cimini, C.; Colombo, B. M.; De Giorgi, A.; Devuono, S.; Delcorso, L.; Denegri, A.; Digiosia, P.; Durante Mangoni, E.; Falsetti, L.; Forgione, A.; Giorgini, P.; Grassi, D.; Grembiale, A.; Hijazi, D.; Iamele, L.; Lorusso, G.; Marchese, A.; Marra, A. M.; Masala, M.; Miceli, G.; Montebianco Abenavoli, L.; Murgia, G.; Naccarato, P.; Pattoneri, P.; Perego, F.; Pesce, P.; Piano, S.; Pinna, M.; Pinto, D.; Pretti, V.; Pucci, G.; Salinaro, F.; Salzano, A.; Santilli, F.; Scarpini, F.; Scicali, R.; Sirico, D.; Suppressa, P.; Talia, M.; Tassone, E. J.; Torres, D.; Vazzana, N.; Vecchio, C. R.; Vidili, G.; Vitale, F.; Zaccone, V

Global attitudes in the management of acute appendicitis during COVID-19 pandemic: ACIE Appy Study

Background: Surgical strategies are being adapted to face the COVID-19 pandemic. Recommendations on the management of acute appendicitis have been based on expert opinion, but very little evidence is available. This study addressed that dearth with a snapshot of worldwide approaches to appendicitis. Methods: The Association of Italian Surgeons in Europe designed an online survey to assess the current attitude of surgeons globally regarding the management of patients with acute appendicitis during the pandemic. Questions were divided into baseline information, hospital organization and screening, personal protective equipment, management and surgical approach, and patient presentation before versus during the pandemic. Results: Of 744 answers, 709 (from 66 countries) were complete and were included in the analysis. Most hospitals were treating both patients with and those without COVID. There was variation in screening indications and modality used, with chest X-ray plus molecular testing (PCR) being the commonest (19\ub78 per cent). Conservative management of complicated and uncomplicated appendicitis was used by 6\ub76 and 2\ub74 per cent respectively before, but 23\ub77 and 5\ub73 per cent, during the pandemic (both P < 0\ub7001). One-third changed their approach from laparoscopic to open surgery owing to the popular (but evidence-lacking) advice from expert groups during the initial phase of the pandemic. No agreement on how to filter surgical smoke plume during laparoscopy was identified. There was an overall reduction in the number of patients admitted with appendicitis and one-third felt that patients who did present had more severe appendicitis than they usually observe. Conclusion: Conservative management of mild appendicitis has been possible during the pandemic. The fact that some surgeons switched to open appendicectomy may reflect the poor guidelines that emanated in the early phase of SARS-CoV-2