Dynamic non-uniform lighting conditions, prevalent in many field robot applications, cause drastic changes in the visual information captured by camera images, resulting in major difficulties for mobile robots attempting to localise visually. Most current solutions to the problem rely on extracting visual information from images that is decoupled from the effects of lighting. This is not possible in many situations. Chrominance information is often cited as having some invariance to lighting changes, which is confirmed by experiments in this thesis. However, in the bland application environments investigated,chrominance is not a pertinent metric, indicating that chrominance is not the complete solution to the lighting problem. Descriptions of the intensity gradient are also cited as having robustness to lighting changes. Many descriptions of image-point features are based on the intensity gradient and are commonly used as a basis for visual localisation. However, the non-uniform effects of lighting – shadows and shading – are tangled into the intensity gradient, making these descriptions sensitive to non-uniform lighting changes. Experiments are presented which reveal that image-point features recorded at one time of the day cannot be reliably matched with images captured only one or two hours later, after typical changes in sunlight. It appears that autonomously building visual maps which permit geometric localisation in many lighting conditions remains an unsolved problem. Therefore, this thesis develops systems based on manually generated maps which are created a priori and ensure that only permanent, invariant, information is included within the map and allows reliable localisation to be achieved in many conditions. The first proposed visual localisation system is for autonomous ground vehicles operating at outdoor industrial sites. The system avoids the problem of mapping from fluctuating visual information by using a professionally-surveyed 3D-edge map of the permanent buildings. The vehicles are fitted with fish-eye cameras that often have direct sunlight in the field of view, causing an issue of camera exposure – dealt with by using an intelligent exposure control algorithm. Results from the system show accurate localisation during the full range of lighting conditions experienced over a day. The second visual localisation framework discussed is for submarines navigating underwater structures, where the only light source is a spotlight mounted on the vehicle. The moving vehicle and hence changing incident angle of the light source cause major variations in the appearance of the structure. This makes it difficult to employ traditional tracking techniques. The proposed localisation system uses the novel idea of incorporating a light source model. The light model is used to render synthetic images of scene – which accurately recreate the non-uniform lighting effects. The synthetic images are compared with the real camera image to localise the vehicle. The idea of using a light model is partly motivated by the human visual system’s understanding of the light source within a scene and is also motivated by the limitations of the traditional approaches to factor-out lighting. Using a light model within a visual localisation system enables a more natural link between the internal environment representation and the image and is demonstrated to allow successful localisation in this difficult visual scenario. The results of the two proposed localisation systems are encouraging, given the extremely challenging dynamic non-uniform lighting in each environment. Both systems have attracted the interest of industry partners and the projects will continue to be developed into the future, with the goal of progressing them into fully functioning robotic systems.

This thesis, after presenting recent advances obtained for the two-dimensional bin packing problem, focuses on the case where guillotine restrictions are imposed. A mathematical characterization of non-guillotine patterns is provided and the relation between the solution value of the two-dimensional problem with guillotine restrictions and the two-dimensional problem unrestricted is being studied from a worst-case perspective. Finally it presents a new heuristic algorithm, for the two-dimensional problem with guillotine restrictions, based on partial enumeration, and computationally evaluates its performance on a large set of instances from the literature. Computational experiments show that the algorithm is able to produce proven optimal solutions for a large number of problems, and gives a tight approximation of the optimum in the remaining cases.

Obiettivo del lavoro è stato lo sviluppo e la validazione di nuovi bioassay e biomarker quali strumenti da utilizzare in un approccio ecotossicologico integrato per il biomonitoraggio di ambienti marino-costieri interessati da impatto antropico negli organismi che vivono in tali ambienti. L’ambiente reale impiegato per l’applicazione in campo è la Rada di Augusta (Siracusa, Italia). Una batteria di bioassay in vivo e in vitro è stata indagata quale strumento di screening per la misura della tossicità dei sedimenti. La batteria selezionata ha dimostrato di possedere i requisiti necessari ad un applicazione di routine nel monitoraggio di ambienti marino costieri. L’approccio multimarker basato sull’impiego dell’organismo bioindicatore Mytilus galloprovincialis in esperimenti di traslocazione ha consentito di valutare il potenziale applicativo di nuovi biomarker citologici e molecolari di stress chimico parallelamente a biomarker standardizzati di danno genotossico ed esposizione a metalli pesanti. I mitili sono stati traslocati per 45 giorni nei siti di Brucoli (SR) e Rada di Augusta, rispettivamente sito di controllo e sito impattato. I risultati ottenuti supportano l’applicabilità delle alterazioni morfometriche dei granulociti quale biomarker di effetto, direttamente correlato allo stato di salute degli organismi che vivono in un dato ambiente. Il significativo incremento dell’area dei lisosomi osservato contestualmente potrebbe riflettere un incremento dei processi degradativi e dei processi autofagici. I dati sulla sensibilità in campo suggeriscono una valida applicazione della misura dell’attività di anidrasi carbonica in ghiandola digestiva come biomarker di stress in ambiente marino costiero. L’utilizzo delle due metodologie d’indagine (bioassay e biomarker) in un approccio ecotossicologico integrato al biomonitoraggio di ambienti marino-costieri offre uno strumento sensibile e specifico per la valutazione dell’esposizione ad inquinanti e del danno potenziale esercitato dagli inquinanti sugli organismi che vivono in un dato ambiente, permettendo interventi a breve termine e la messa a punto di adeguati programmi di gestione sostenibile dell’ambiente. / The aim of the work was the development and validation of new bioassays and biomarkers as tools in an integrated ecotoxicological approach for the biomonitoring of impacted coastal marine environment environments. The Rada of Agusta (Syracuse, Sicily) was used as real environment for the field application of the proposed integrated approach. A battery of in vivo and in vitro bioassays was investigated as screening tool of the assessment of marine sediment toxicity. The battery has proven to have the necessary requirement for a routine application in marine coastal environment biomonitoring. The multimarker approach based on the use of bioindicator organism Mytilus galloprovincialis in translocation experiments allowed to evaluate the field application potential of new cytological and molecular biomarkers in parallel to standardized biomarkers of genotoxicity and heavy metal exposure. Mussels were caged for 45 days in Brucoli (SR) and Rada di Augusta, reference site and impacted site respectively. Results support the applicability of granulocytes morphometric alterations as effect biomarker, directly correlated to the health of the organism. Morphometric alterations were accompanied by a significative increase of the lysosomal compartment, which in turn could reflect the pollutant induced increase of the degradative and autophagic processes. Carbonic anhydrase activity in digestive gland proved to be a valuable biomarker of chemical stress in marine coastal environment. The functional role of carbonic anhydrase in the lysosomal compartment functioning was evaluated. The combined use of the two methodologies (bioassays and biomarkers) in an integrated ecotoxicological approach provides a sensitive and specific tool for the assessment of pollutant exposure and pollutant effects in biomonitoring of coastal marine environment, facilitating the application of monitoring data in risk-based decision making

The study of optic flow on postural control may explain how self-motion perception contributes to postural stability in young males and females and how such function changes in the old falls risk population. Study I: The aim was to examine the optic flow effect on postural control in young people (n=24), using stabilometry and surface-electromyography. Subjects viewed expansion and contraction optic flow stimuli which were presented full field, in the foveral or in the peripheral visual field. Results showed that optic flow stimulation causes an asymmetry in postural balance and a different lateralization of postural control in men and women. Gender differences evoked by optic flow were found both in the muscle activity and in the prevalent direction of oscillation. The COP spatial variability was reduced during the view of peripheral stimuli which evoked a clustered prevalent direction of oscillation, while foveal and random stimuli induced non-distributed directions. Study II was aimed at investigating the age-related mechanisms of postural stability during the view of optic flow stimuli in young (n=17) and old (n=19) people, using stabilometry and kinematic. Results showed that old people showed a greater effort to maintain posture during the view of optic flow stimuli than the young. Elderly seems to use the head stabilization on trunk strategy. Visual stimuli evoke an excitatory input on postural muscles, but the stimulus structure produces different postural effects. Peripheral optic flow stabilizes postural sway, while random and foveal stimuli provoke larger sway variability similar to those evoked in baseline. Postural control uses different mechanisms within each leg to produce the appropriate postural response to interact with extrapersonal environment. Ageing reduce the effortlessness to stabilize posture during optic flow, suggesting a neuronal processing decline associated with difficulty integrating multi-sensory information of self-motion perception and increasing risk of falls.

Logistics involves planning, managing, and organizing the flows of goods from the point of origin to the point of destination in order to meet some requirements. Logistics and transportation aspects are very important and represent a relevant costs for producing and shipping companies, but also for public administration and private citizens. The optimization of resources and the improvement in the organization of operations is crucial for all branches of logistics, from the operation management to the transportation. As we will have the chance to see in this work, optimization techniques, models, and algorithms represent important methods to solve the always new and more complex problems arising in different segments of logistics. Many operation management and transportation problems are related to the optimization class of problems called Vehicle Routing Problems (VRPs). In this work, we consider several real-world deterministic and stochastic problems that are included in the wide class of the VRPs, and we solve them by means of exact and heuristic methods. We treat three classes of real-world routing and logistics problems. We deal with one of the most important tactical problems that arises in the managing of the bike sharing systems, that is the Bike sharing Rebalancing Problem (BRP). We propose models and algorithms for real-world earthwork optimization problems. We describe the 3DP process and we highlight several optimization issues in 3DP. Among those, we define the problem related to the tool path definition in the 3DP process, the 3D Routing Problem (3DRP), which is a generalization of the arc routing problem. We present an ILP model and several heuristic algorithms to solve the 3DRP.

Introduzione: l’epatite cronica C è la più comune infezione virale trasmessa per via ematica e la principale causa di mortalità tra le epatopatie. La terapia antivirale può prevenire la progressione della malattia nei pazienti HCV. Telaprevir e simeprevir sono Direct Acting Antivirals e due inibitori delle proteasi, utili nell’eradicazione del virus. Scopo: stabilire l’efficacia e sicurezza di un regime di terapia antivirale con telaprevir, pegIFN/ribavirin e di uno con simeprevir-sofosbuvir+/- ribavirina. Metodi: 35 pazienti venivano consecutivamente arruolati nel gruppo telaprevir (54.3% maschi, età mediana 61, 43-71) e confrontati con 70 controlli, selezionati random da una popolazione di pazienti trattati con simeprevir-sofosbuvir e appaiati per età, sesso e fibrosi. Erano valutati l’efficacia misurata attraverso la risposta virologica sostenuta (SVR) e il miglioramento dei parametri biochimici, e la sicurezza. Risultati: i pazienti trattati con telaprevir presentavano eventi avversi nel 94.2% dei casi contro il 28.6% del gruppo simeprevir (p.000). Gli eventi avversi di grado severo si concentravano poi tutti nel gruppo telaprevir (20% vs 0%, p.000). Il più comune evento avverso in entrambi i gruppi era rappresentato dall’anemia (77.1% nel gruppo telaprevir va 14.3% nel gruppo simeprevir, p 0.000). L’SVR era del 91.4% nei casi e del 71.4% nei controlli (p 0.01). L’utilizzo di ribavirina, il tipo di genotipo 1 e lo stadio di fibrosi, non influenzavano i tassi di SVR. Conclusioni: il nostro studio ha mostrato che il telaprevir è meno efficace e sicuro del simeprevir nei pazienti con fibrosi avanzata o cirrosi epatica. I dati confermano l’indicazione a preferire i regimi liberi da interferone a quelli che lo contengono ancora. / Introduction: Chronic hepatitis C (CHC) is the most common viral infection blood-transmitted and it is the leading cause of death from liver disease. Antiviral therapy can prevent disease progression in patients with CHC. Telaprevir and Simeprevir are Direct Acting Antivirals and two protease inhibitor, useful in the eradication of the virus. Aim: to assess the safety and efficacy of telaprevir-based antiviral therapy with pegIFN/ribavirin or simeprevir-based antiviral therapy with sofosbuvir ± ribavirin. Methods: consecutive 35 CHC patients (54.3% males, median age 61, range 43-71) were enrolled in telaprevir group and compared with 70 controls, randomly selected from the population of patients treated with simeprevir-sofosbuvir and matched by age ± 5 years, sex and degree of fibrosis. Efficacy by sustained virological response (SVR) and improvement of laboratory tests and safety were evaluated. Results: patients treated with telaprevir had adverse events in 94.2% of cases while occurred in 28.6% of patients treated with simeprevir (p.000). Severe adverse events occurred all in telaprevir group (20% vs 0%, p 0.000). The most common adverse event in both groups was anemia (77.1% in telaprevir treatment vs 14.3% in simeprevir treatment, p 0.000). SVR was 91.4% in cases and 71.4% in controls (p 0.01). Use of ribavirin, type of genotype 1 and stage of fibrosis did not affect SVR rates. Conclusion: our study showed the telaprevir is less effective and safe compared to simeprevir in patients with advanced fibrosis or cirrhosis. The data confirm the indication to prefer interferon free regimens to those still based on interferon in this setting.

In this thesis we study selected topics in the field of Mixed Integer Programming (MIP), in particular Mixed Integer Linear and Nonlinear Programming (MI(N)LP). We set a focus on the influences of Constraint Programming (CP). First, we analyze Mathematical Programming approaches to water network optimization, a set of challenging optimization problems frequently modeled as non-convex MINLPs. We give detailed descriptions of many variants and survey solution approaches from the literature. We are particularly interested in MILP approximations and present a respective computational study for water network design problems. We analyze this approach by algorithmic considerations and highlight the importance of certain convex substructures in these non-convex MINLPs. We further derive valid inequalities for water network design problems exploiting these substructures. Then, we treat Mathematical Programming problems with indicator constraints, recalling their most popular reformulation techniques in MIP, leading to either big-M constraints or disjunctive programming techniques. The latter give rise to reformulations in higher-dimensional spaces, and we review special cases from the literature that allow to describe the projection on the original space of variables explicitly. We theoretically extend the respective results in two directions and conduct computational experiments. We then present an algorithm for MILPs with indicator constraints that incorporates elements of CP into MIP techniques, including computational results for the JobShopScheduling problem. Finally, we introduce an extension of the class of MILPs so that linear expressions are allowed to have non-contiguous domains. Inspired by CP, this permits to model holes in the domains of variables as a special case. For such problems, we extend the theory of split cuts and show two ways of separating them, namely as intersection and lift-and-project cuts, and present computational results. We further experiment with an exact algorithm for such problems, applied to the Traveling Salesman Problem with multiple time windows.

Oggetto: Ruolo dell’ ecoendoscopia (EUS) nello studio dei tumori neuroendocrini del tratto digestivo è la stadiazione locoregionale basata sulla valutazione dell’ estensione di profondità di parete (T) e l’ interessamento dei linfonodi loco-regionali (N) con un’accuratezza diagnostica del 94-100%. La resezione endoscopica è un’ opzione di trattamento. Scopo dello studio è stato valutare l’ accuratezza diagnostica dell’ EUS nella stadiazione locale dei tumori neuroendocrini gastrici, duodenali e rettali macroscopicamente suscettibili di resezione endoscopica e valutare l’efficacia della resezione endoscopica. Materiali e metodi: Studio retrospettivo condotto su una coorte consecutiva di pazienti con diagnosi di neoplasia neuroendocrina del tratto gastroenterico afferenti all’ Istituto Europeo di Oncologia di Milano. Risultati: Sono stati sottoposti ad EUS 21 pazienti per un totale di 22 lesioni da Settembre 2001 a Gennaio 2016. 21 lesioni erano confinate alla sottomucosa, soltanto in una lesione gastrica è stato posto il dubbio di infiltrazione superficiale della tonaca muscolare propria e in una lesione del retto riscontro di una linfoadenopatia di aspetto secondario. 11 lesioni erano nello stomaco (NET gastrico di tipo 1), 5 nel duodeno e 5 nel retto. Le lesioni sono state asportate per via endoscopica in pezzo unico intero. All’ analisi istopatologica 21 lesioni erano limitate alla sottomucosa, tranne il caso con dubbia infiltrazione della tonaca muscolare che presentava interessamento dello strato muscolare superficiale. In 2 dei 21 è stato valutato l’ interessamento linfonodale dopo resezione chirurgica. In 10 di 22 lesioni con infiltrazione dei margini di resezione non si è riscontrata recidiva di malattia durante il follow-up (media 34 mesi, 3-126 mesi). Conclusioni: L’ EUS è una metodica valida nella valutazione della resecabilità endoscopica dei NETs gastrici di tipo 1, del bulbo e del retto. La resezione endoscopica è risultata efficace nel trattamento di queste neoplasie anche in presenza di infiltrazione dei margini di resezione. / Background and aim: Diagnostic role of endoscopic ultrasound (EUS) in gastrointestinal neuroendocrine tumors (GE-NETs) is the local staging based on the assessment of wall depth (T) and of lymph nodes metastasis (N). Diagnostic accuracy of EUS in T-staging is 94-100%. Endoscopic resection is a treatment option in selected cases. Aim of the current study was to evaluate diagnostic accuracy of EUS in the local staging of GE-NETs candidates to endosciopic resection and the efficacy of endoscopic resection in gastrointestinal neuroendocrine NETs’ treatment. Methods: This is a retrospective analysis of a prospectively collected database. Patients with GE-NETs that underwent EUS and endoscopic resection at Istituto Oncologico Europeo (IEO) were included. Results: From September 2001 to January 2016, 21 patients for a total of 22 GE-NETs underwent EUS: 21 GE-NETs were confined to the submucosa layer; 1 case presented a doubtful involvement of the proper muscolaris layer. 11 NETs were in the stomach, 5 NETs in the duodenum and 5 NETs in the rectum. All but one rectal NET case were negative for metastatic lymph nodes. All the 22 lesions were endoscopically resected in one piece by endoscopic resection. The histological analysis confirmed that twenty-one lesions were confined to the submucosa layer and that one case was involved the proper muscolaris layer. The involvement of lymph nodes was evaluated in only the two cases who underwent surgical resection. Ten out of 22 lesions had positive margins at the histological analysis but no recurrence were observed during follow-up (mean 34 months; range 3-126). Conclusions: EUS is useful for estimating the depth of invasion of type 1 gastric neuroendocrine tumor, duodenal and rectal neuroendocrine tumors and for determining whether endoscopic resection is indicated. Endoscopic resection is effective in gastrointestinal neuroendocrine NETs’ treatment.

Come molti altri settori produttivi, anche l'agricoltura deve affrontare una crescente dipendenza energetica da elettricità, petrolio e gas naturale. Tuttavia, l'agricoltura può rispondere direttamente a tali richieste ricorrendo alle fonti di energia rinnovabili (FER), come il solare fotovoltaico (PV) e gli impianti biogas/biometano (BP). Questi sistemi sono stati fortemente incentivati in passato. Gli attuali sistemi d’incentivazione prevedono invece sussidi commisurati alle caratteristiche aziendali come stalle, fienili, disponibilità di biomasse, ecc. Per questi motivi, per quanto riguarda il settore FV, è necessario utilizzare modelli analitici affidabili per valutare l’orientamento e la tecnologia migliore, in particolare per generatori integrati architettonicamente. Per la produzione di biometano, gli impianti di piccole dimensioni risultano quelli maggiormente incentivati previa alimentazione con sottoprodotti agro-industriali. Tuttavia, le loro performance dipendono fortemente dalla tecnologia d’upgrading. Pertanto, le prospettive economiche offerte da questi sistemi RES sono legate alla scelta della tecnologia da impiegare e non più esclusivamente al semplice dimensionamento. Su questa base, l'obiettivo principale di questo lavoro è stato lo sviluppo di strumenti di supporto decisionali (DSSS) per l'ottimizzazione energetica d’impianti FV e BP. Un primo studio si è focalizzato sull’analisi prestazionale per singolo componente e globale d’impianti FV installati in un’azienda agricola. Inoltre, una procedura analitica di ottimizzazione dei parametri d’impianto è stata definita per massimizzare il rendimento elettrico di un generatore integrato architettonicamente rispetto ad un’installazione a terra. Attraverso una serie d’informazioni tecnico-economiche di tecnologie di upgrading, un secondo studio è stato condotto con l'obiettivo di sviluppare un DSS per valutare la marginalità sul reddito aziendale data dall’installazione on-farm di un impianto BP collegato alla rete del gas naturale. I risultati dei due studi hanno dimostrato come questi DSS possono essere utili strumenti per valutare preventivamente le diverse potenzialità offerte da impianti FV e BP in base alle caratteristiche di un’azienda agricola. / Like many other productive sectors, even agriculture must tackle an increasing energy dependency on electricity, petroleum and natural gas. Nevertheless, agriculture can directly respond to such request thanks to renewable energy systems (RES) like solar photovoltaic (PV) and biogas/biomethane (BP) plants. These systems have been strongly incentivized in the past. On the contrary, current incentive schemes provide feed-in-tariffs proportionate to farming characteristics as stables, barns, biomass availability, etc. For this reason, as regards the PV sector, it is required to use reliable analytical models for assessing the best orientation and technology, in particular for architecturally integrated generators. For the biomethane production, small-medium plants have stronger incentives in particular using agro-food by-products as feed. However, their performances are strongly dependent on biomethane upgrading technology. Thus, the economic prospective offered by these RES systems are substantially tied to technology choice optimization and no longer solely in simple sizing. On this basis, the main goal of this work is to develop Decision Support Tools (DSSs) for energy optimization both for PV and BP plants. A first study was focused on the analysis of PV plants installed in the same farm. The aim is to examine the impact each plant component has on the PV generator global efficiency and define an analytical procedure for technical parameters optimization in order to maximize the electric yield of an architectonically integrated plant compared to a ground-mounted one. Based on the economic and efficiency features of a biomethane upgrading technology set, a second study was carried out with the aim to design a DSS to assess enterprise-wide profit margins resulting from the on-farm BP plant installation linked to the natural gas grid. The results of the two studies have shown how these DSSs can be useful tools for choosing PV and BP technologies based on farm characteristics.

La trombosi portale non neoplastica (PVT) è una complicanza frequente della cirrosi epatica. Attualmente, gli unici fattori di rischio associati, ripetutamente confermati in letteratura, sono il precedente sanguinamento da varici esofagee e la piastrinopenia che sbilancia il precario equilibrio coagulativo tipico della cirrosi. Tra Gennaio 2013 e Ottobre 2015, sono stati arruolati prospetticamente 253 pazienti cirrotici (età media 58,8 ± 10,3 (23 – 75) anni) senza neoplasie anamnestiche e/o malattia ematologica e liberi da terapia anticoagulante/antiaggregante assunta er altre cause. Nel campione raccolto sono stati studiati: lo stadio di malattia secondo il Child-Pugh (CP) e il Model for end-stage liver disease (MELD) scores, eziologia, età ed esami laboratoristici. I pazienti con PVT sono stati il 13%, di cui il 63,3% maschi, significativamente più giovani dei controllonegativi (51,9 ± 13,2 (23 – 75) anni; P=0,004), con una maggior piastrinopenia (73,1 ± 48,1 (25 – 174); P = 0,001), INR > 1.25 in 54,5% dei casi (P=0,024) e MELD >10 in 86,2% (P=0,001). INR e MELD sono state considerate anche come valore continuo senza raggiungere la significatività come eziologia, ematocrito, Bilirubina ttale, AST, ALT, Albumina, Creatinina e CP score e classe. All'analisi multivariata solo la conta piastrinica è risultata indipendentemente associata alla presenza di PVT (OR = 0.97, 95% CI: 0.96-0.99; P <0.001) come da letteratura. Le trombocitopenie ereditarie (ITs) sono un gruppo eterogeneo di disordini genetici con diversi gradi di severità e cmplessità caratterizzate da piastrinopenia associata o meno a sanguinamento di variabile entità. Tali disordini, in un substrato così favorevole come la cirrosi epatica, potrebbe spiegare l'eterogeneità dei quadri clinici e la risposta apparentemente casuale alla terapia anticoagulante. Non abbiamo ancora dati che confermino questa ipotesi alternativa, ma se così fosse, probabilmente l'approccio clinico a questa problematica cambierebbe significativamente. / Non-neoplastic porta vein thrombosis (PVT) in cirrhotic patients is a frequent complication of liver cirrhosis. Yet, only confirmed data about its natural history are the association with variceal bleeding and low platelet count which influences this precarious coagulation balance. In our prospective study, from January 2013 to October 2015, we enrolled 253 cirrhotic patients (mean age 58,8 ± 10,3 (23 – 75) years) without a history of malignancy and/or hematological disease and who aren’t on oral anticoagulants or antiplatelet therapy taken for other reasons. Overall were subsequently studied according to the degree of liver disease using the Child-Pugh (CP) and Model for end-stage liver disease (MELD) scores, etiology, age and blood tests. Patient with PVT, of which 63,3% males, was significantly younger (51,9 ± 13,2 (23 – 75) yrs; P=0,004), with lesser platelet count (73,1 ± 48,1 (25 – 174); P = 0,001), INR > 1.25 in 54,5% of cases (P=0,024) and MELD >10 in 86,2% (P=0,001). INR and MELD considered as continuous variables were not significant as well as etiology, hematocrit, total Bilirubin, AST, ALT, Albumine, Creatinine and CP score and class. In multivariate analysis, only the platelet count was independently associated with the occurance of PVT (OR = 0.97, 95% CI: 0.96-0.99; P <0.001) confirming the literature. The inheritated thrombocytopenias (ITs) are a heterogeneous group of genetic disorders with different degrees of complexity and severity, characterized by a low platelets count associated or not with a bleeding tendency which varies from absent to very strict. This group of diseases, in the context of an extremely favorable substrate such as cirrhotic degeneration, would explain the heterogeneity of the cadres and random responses to anticoagulation. We have no data yet certain about this, but if this hypothesis be confirmed, the clinical approach to the disease might change dramatically.