A stochastic estimated version of the Italian dynamic General Equilibrium Model (IGEM)

We estimate with Bayesian techniques the Italian dynamic General Equilibrium Model (IGEM), which has been developed at the Italian Treasury Department, Ministry of Economy and Finance, to assess the effects of alter-native policy interventions. We analyze and discuss the estimated effects of various shocks on the Italian economy. Compared to the calibrated version used for policy analysis, we find a lower wage rigidity and higher adjustment costs. The degree of prices and wages indexation to past inflation is much smaller than the indexation level assumed in the calibrated model. No substantial difference is found in the estimated monetary parameters. Estimated fiscal multipliers are slightly smaller than those obtained from the calibrated version of the model

Bayesian Ideas in Survey Sampling: The Legacy of Basu

Survey sampling and, more generally, Official Statistics are experiencing an important renovation time. On one hand, there is the need to exploit the huge information potentiality that the digital revolution made available in terms of data. On the other hand, this process occurred simultaneously with a progressive deterioration of the quality of classical sample surveys, due to a decreasing willingness to participate and an increasing rate of missing responses. The switch from survey-based inference to a hybrid system involv- ing register-based information has made more stringent the debate and the possible resolution of the design-based versus model-based approaches con- troversy. In this new framework, the use of statistical models seems unavoid- able and it is today a relevant part of the official statistician toolkit. Models are important in several different contexts, from Small area estimation to non sampling error adjustment, but they are also crucial for correcting bias due to over and undercoverage of administrative data, in order to prevent potential selection bias, and to deal with different definitions and/or errors in the measurement process of the administrative sources. The progressive shift from a design-based to a model-based approach in terms of super-population is a matter of fact in the practice of the National Statistical Institutes. How- ever, the introduction of Bayesian ideas in official statistics still encounters difficulties and resistance. In this work, we attempt a non-systematic review of the Bayesian development in this area and try to highlight the extra ben- efit that a Bayesian approach might provide. Our general conclusion is that, while the general picture is today clear and most of the basic topics of survey sampling can be easily rephrased and tackled from a Bayesian perspective, much work is still necessary for the availability of a ready-to-use platform of Bayesian survey sampling in the presence of complex sampling design, non-ignorable missing data patterns, and large datasets

Portal Hypertension in Childhood Bilateral Wilms' Tumor Survivor: An Excellent Indication for TIPS

Introduction. Increased pressure in portal venous system is relatively a rare complication after chemoradiotherapy for Wilms' tumor (WT). In paediatric population, feasibility and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in portal hypertension nonresponsive to medical or endoscopic treatment have been recently advocated. We report a case of TIPS positioning in a 15-year-old girl with portal hypertension as a long-term sequel of multimodality therapy in bilateral WT. Case Report. Two-year-old girl was diagnosed for bilateral WT. Right nephrectomy with left heminephrectomy and chemoradiotherapy were performed. At 7 years of age, the first gastrointestinal bleeding appeared, followed by another episode two years later, both were treated successfully with beta-blockers. At 15 years of age, severe unresponsive life-threatening gastroesophageal bleeding without hepatosplenomegaly was managed by TIPS. Reduction of the portosystemic pressure gradient was obtained. Conclusion. TIPS positioning for portal hypertension in long-term tumors' sequel is feasible and could be considered as an additional indication in paediatric patients

10-Gb/s Operation of a Colorless Self-Seeded Transmitter Over More Than 70 km of SSMF

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Overview and analysis of optical sensing techniques over deployed telecom networks

In this Invited Paper, we review the most promising techniques that have been recently proposed for optical sensing over deployed telco fiber networks, with a particular emphasis on methods that allow coexistence with telco traffic (typically using a WDM approach). For the most promising solutions, physical layer simulations and experiments are presented to further elaborate on coexistence constraints

Self-Seeded RSOA-Fiber Cavity Lasers vs. ASE Spectrum-Sliced or Externally Seeded Transmitters—A Comparative Study

Reflective semiconductor optical amplifier fiber cavity lasers (RSOA-FCLs) are appealing, colorless, self-seeded, self-tuning and cost-efficient upstream transmitters. They are of interest for wavelength division multiplexed passive optical networks (WDM-PONs) based links. In this paper, we compare RSOA-FCLs with alternative colorless sources, namely the amplified spontaneous emission (ASE) spectrum-sliced and the externally seeded RSOAs. We compare the differences in output power, signal-to-noise ratio (SNR), relative intensity noise (RIN), frequency response and transmission characteristics of these three sources. It is shown that an RSOA-FCL offers a higher output power over an ASE spectrum-sliced source with SNR, RIN and frequency response characteristics halfway between an ASE spectrum-sliced and a more expensive externally seeded RSOA. The results show that the RSOA-FCL is a cost-efficient WDM-PON upstream source, borrowing simplicity and cost-efficiency from ASE spectrum slicing with characteristics that are, in many instances, good enough to perform short-haul transmission. To substantiate our statement and to quantitatively compare the potential of the three schemes, we perform data transmission experiments at 5 and 10 Gbit/s

Self-Seeded RSOAs WDM PON Field Trial for Business and Mobile Fronthaul Applications

GEth, CPRI and 10 Gbit/s transmissions are experimented using amplified and standard self-seeded RSOA WDM PON systems. A field trial setup was exploited to test the system performance in terms of reach and optical budget

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Optical transmitter based on self-seeded architectures for passive WDM networks

Le futuri reti per l'accesso, in grado di sostenere la forte crescita del traffico Internet, sono state recentemente standardizzate dal'ITU-T all'interno delle raccomandazioni Next Generation Passive Optical Network 2 (NG-PON2). La struttura proposta è una architettura di tipo ibrido a multiplazione di tempo e lunghezza d'onda (TWDM) e dovrà essere in grado di garantire un bit-rate di 10 Gb/s per il segnale upstream lungo decine di chilometri tra l'utente e il central office. Le reti a divisione di lunghezza d'onda (WDM) possono beneficiare enormente della disponibilità di trasmettitori di tipo "colorless" e "self-seeding", in modo da poter ridurre i costi di inventario ed eliminare la necessità di un livello di controllo che assegni all'utente una specifica lunghezza d'onda. In seguito alla evoluzione della tecnologia radio, è stato introdotto un nuovo segmento della topologia di una rete radio, chiamato "fronthaul", tra la remote radio head (RRH) e la base band unit (BBU) con l'obiettivo di ottenere una centralized radio access network (C-RAN). Questa nuova struttura permette un utilizzo più efficiente della fibra ottica già distribuita. A causa dell'elevato numero di collegamenti per ogni antenna radio, si rende necessaria anche una tecnica di multiplazione. Ogni collegamento tra antenna e BBU dovrà poter garantire bit rates da 614 Mb/s a 9.8 Gb/s su lunghezze comparabili a quelle richieste nella rete d'accesso. Una rete WDM rappresenta, al momento, una delle più interessanti soluzioni per il fronthaul poichè permette la creazione di collegamenti virtuali di tipo punto punto tra ogni antenna e la rispettiva BBU al central office. Così come per le reti d'accesso, il successo di tali soluzioni nel fronthaul è legato alla disponibilità di trasmettitori di tipo "colorless" e "self-seeding". Questo lavoro di dottorato si è focalizzato sullo studio di una soluzione colorless per trasmettitori upstram in reti ottiche passive per reti d'accesso e fronthaul. Si basa sull'utilizzo di un reflective semiconductor optical amplifier (RSOA) collocato presso ogni utente (optical network unit, ONU) o antenna e coincide fisicamente con una parte della rete stessa. Il trasmettitore infatti può essere indicato come una cavità laser estesa, che comprende l'RSOA, la cui faccia riflettente rappresenta uno degli specchi della cavità, la fibra tra utente e nodo remoto (drop fiber), il mux/demux (AWG) e un secondo specchio entrambi collocati al nodo remoto (RN). L'AWG rappresenta l'elemento che seleziona automaticamente la lunghezza d'onda, senza bisogno di ulteriori livelli di controllo e gestione all'OLT. L'RSOA presente in ogni ONU è l'elemento chiave del trasmettitore proposto in quanto ha tre funzioni distinte, tutte necessarie ad un corretto funzionamento dello stesso: fornisce il guadagno ottico per sotenere le perdite dlela cavità laser, è l'elemento modulato direttamente con il segnale upstream e, funzionando in regime di saturazione, cancella la modulazione ricircolante in seguito alla riflessione al RN. Queste funzioni sono state studiate in dettaglio durante il progetto di dottorato. La limitata banda elettro/ottica degli RSOA, tipicamente intorno ai 2 GHz, rappresenta il principale ostacolo all'aumento del bit rate del segnale di upstream, pur mantenendo buone prestazioni in trasmissione. In particolare, modulare direttamente gli RSOA con segnali a 10 Gb/s risulta essere molto impegnativo. Dispositivi con banda E/O fino a 4 GHz sono disponibili, in banda C, ma a causa del design dei componenti, prensentano anche un elevata dipendenza del guadagno dalla polarizzazione, maggiore di 20 dB. Se lo stato di polarizzazione del segnale ricircolante non è allineato con l'asse di guadagno dell'RSOA allora le perdite totali della cavità potrebbero risultare troppo elevate rispetto al guadagno. E' stato quindi studiata una topologia alternativa, basata su un Faraday rotator mirror al RN e un Farday rotator all'ONU, che potesse garantire che lo stato di polarizzazione in ingresso risulti sempre allineato con l'asse principale dell'RSOA. Grazie a questa topologia è stato quindi possibile utilizzare dispositivi ad elevato PDG e con prestazioni migliori anche in presenza di segnali di upstream ad alto bit-rate (10 Gb/s). Con RSOA che emettono in banda C (ovvero intorno ai 1550 nm) sono state ottenute buone prestazioni a 2.5 Gb/s e 5 Gb/s, con collegamenti fino a 50 km e 24 km rispettivamente; nelle misure a 10 Gb/s era invece evidente l'impatto dlela dispersione cromatica se vengono utilizzate fibre standard (SSMF), a causa del chirp in frequenza del segnale in uscita dal trasmettitore. Nelle fibre SSMF il coefficiente di dispersione è quasi nullo nell'intorno dei 1300 nm; quindi, utilizzando RSOA in banda O (in grado quindi di emettere in un intorno dei 1300 nm) è stato possibile modulare a 10 Gb/s e ottenere valori di BER inferiori al limite del FEC (3·10-3), utilizzando AWG commercialmente disponibili, drop fiber fino a 1 km e fibra di distribuzione fino a 40 km.Future access networks capable of sustaining the increasing demand of capacity have recently been standardized by ITU-T under the Next Generation Passive Optical Network 2 (NG-PON2) recommendations; the proposed hybrid time and wavelength division multiplexing (TWDM) architecture is required to guarantee 10 Gb/s upstream rates per user over tens of kilometers between user and central office. WDM-based networks can greatly benefit from availability of colorless transmitters, reducing inventory costs and eliminating the needs of control layer for wavelength assignment. Due to the evolution of the radio technologies, a new fronthaul segment is appearing between remote radio head (RRH) and base band unit (BBU) to achieve a centralized radio access network (C-RAN) architecture. This optical network has to be optimized in order to make efficient usage of fibers and minimize deployment cost. Moreover, to deal with the high number of digital radio over fiber links per antenna site (one potential link per carrier, per radio sector, per mobile generation), this optical network requires the exploitation of a multiplexing technique. Based on common public radio interface (CPRI) radio, link data rates can range from 614 Mb/s to 9.8 Gb/s and the link length from each antenna and BBU hotel are comparable to the one required in access networks. A WDM network is, at present, one of the most interesting solutions, as is allow to setup a virtual point to point connection between each antenna and the corresponding BBU at the central office. As for access networks, the availability of colorless transmitters is a key factor for successful implementation of WDM networks applied to fronthaul. This PhD work has been focused on the study of a colorless solution for the upstream PON transmitter for access and fronthaul applications; it's based on the exploitation of a reflective semiconductor optical amplifier (RSOA) located at each optical network unit (ONU) or antenna and physically coincides with a portion of the network itself. The transmitter relies on a laser cavity, which comprises an RSOA active chip, placed at the ONU, whose reflective ends is one of the cavity mirrors, the drop fiber, which connects the ONU and the remote node, the remote node (RN) arrayed waveform guide (AWG) multiplexer and a mirror also placed at the RN. The AWG is the cavity wavelength-selective element. This WDM solution brings the advantage of self-selecting the wavelength by simply connecting the drop fiber to the multiplexing element at the remote node. No more management and control interface by the optical line terminal at the central office (CO) is required to set up the wavelength. The RSOA device in each ONU is the key element in the proposed transmitter as it plays the triple role of sustaining the cavity gain, of modulating the transmitted signal via its bias current and of bleaching the recirculating modulation inside the cavity. We studied in detail each of these functions and showed how each represents a crucial aspects for the proper operation of the transmitter. The small E/O bandwidth of the RSOA, ~2 GHz in typical devices, is the main limit to the maximum upstream bit rate at which the proposed transmitter can reach good performance. In particular, with such small E/O bandwidth, direct modulation of the RSOAs with 10 Gb/s OOK is very challenging. RSOAs devices with E/O bandwidth up to 4 GHz, in C-band devices, are available but, due to the their design, they also present very high polarization dependent gain, higher than 20 dB. If the recirculating state of polarization is not aligned to the principle axis of the RSOA the total losses can be higher than the gain. Hence, we presented and studied a topology of the self seeded transmitter, based on a Faraday rotator mirror at the remote node and a Faraday rotator at the ONU; using this topology we proved that the input polarization is stable and always aligned to the principle axis of the RSOA. Hence, thanks to the proposed topology, we are able to use faster HPDG RSOAs for the self seeded transmitter and have a better performance when the upstream signal is at high bit rate, like 10 Gb/s. With RSOA emitting in the C-band (i.e. 1550 nm) we were able to obtain good performance at 2.5 Gb/s and 5 Gb/s, with optical distribution network (ODN) links up to 50 km and 24 km respectively; at 10 Gb/s measurements with C-band RSOA have showed the great impact of the chromatic dispersion when SSMF are exploited for the optical distribution network, due to the frequency chirp of the output signal. In SSMF the dispersion coefficient is close to zero at 1300 nm; thus, exploiting O-band RSOA (i.e. emitting light in the 1300-nm band) we were able to directly modulate the RSOA at 10 Gb/s and obtain a BER below the 3·10-3 FEC limit with commercial AWG, drop fiber link up to 1 km and feeder fiber link of 40 km, both with SSMF. For legacy consideration with the previous PON generation, the ITU recommendation in NG-PON2 suggest the C-band for upstream signal from the ONU to CO, while the O-band is used by the already deployed GPON. Moreover, the vast majority of the fiber already deployed for access and metropolitan network is SSMF. Hence the self seeded transmitter in the C-band can represent an interesting solution for PON with bit rate limited at 2.5 Gb/s or 5 Gb/s while, for PON at 10 Gb/s more optimization is still required, primarily in the increase of E/O bandwidth of the devices, to allow longer link connections between ONUs and CO with BER below the FEC limit. In a green field environment, with the possibility to deploy dispersion shifted fiber, the C-band transmitter can be suitable even for a signal at 10 Gb/s, allowing the link length required by the recommendation. While permitting the reuse of the deployed SSMF, also the O-band self seeded transmitter can be considered for access network applications only in a green field environment, where the O-band is not already reserved for signal of previous generation of PON solutions. On the other hand, the relatively new network segment for mobile fronthaul lacks of proper standardizations or recommendations, without indications on the dedicated transmission band for example; hence, the colorless transmitter for WDM networks studied in this thesis represents an efficient multiplexing technique to connect several RRHs with centralized BBUs. In particular, the O-band transmitter can support 10 Gb/s (required by standard interfaces such as CPRI) with 40-km long links over SSMF, fulfilling the basic requirements of future mobile networks.DIPARTIMENTO DI ELETTRONICA, INFORMAZIONE E BIOINGEGNERIATelecommunications28BELLINI, SANDROBONARINI, ANDRE

Emergenza abitativa e baracche a Roma tra le due guerre

La ricerca prende spunto da un più ampio ambito di indagine volto ad approfondire il tema delle condizioni abitative a Roma nel corso del Novecento. Per larghi tratti la storia postunitaria di Roma è stata caratterizzata da un deficit di spazi abitativi che talora ha assunto i caratteri di emergenza sociale, particolarmente acuta per i soggetti con minori capacità di spesa. Una delle conseguenze dell’insufficiente offerta di abitazioni per i ceti più popolari fu il diffondersi di insediamenti informali, baraccopoli composte da alloggi che rispondevano agli elementari bisogni abitativi di immigrati e famiglie già residenti. Tali presenze, in diverse aree della città ben percepibili fino all’inizio degli anni Ottanta, furono oggetto delle attenzioni delle autorità locali che in più occasioni provvidero a censire i baraccati. Quei censimenti forniscono dati utili alla comprensione del fenomeno ma molti aspetti restano da approfondire. A questo riguardo, un’opportunità viene offerta dalla documentazione conservata presso l’Archivio Storico Capitolino, tra la quale figura anche l’intero corpus delle schede di rilevazione compilate in occasione del censimento dei baraccati del 1933. Si tratta di documenti riguardanti oltre 4.400 famiglie che contengono una considerevole mole di elementi analitici finora usati solo parzialmente. Attraverso la costruzione di un database che ne recepisca integralmente il potenziale informativo, l’uso di aggiornate metodologie statistiche e sistemi di georiferimento, rendono oggi possibile indagare con un inedito grado di dettaglio le caratteristiche demografiche, sociali ed economiche di coloro che abitavano le baraccopoli romane nei primi anni Trenta. La realizzazione della base di dati, è tuttora in corso – sono stati inseriti le informazioni relative a circa 1.500 schede, poco meno di un terzo del totale – ma alcune prime elaborazioni, sebbene parziali e provvisorie, lasciano già emergere nuovi ed interessanti spunti da valutare anche in chiave comparativa con quanto evidenziato dalle rilevazioni condotte dal dopoguerra