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Somalia – Mogadiscio – La Fontana della Garesa
No full textImmagine tratta dal sito "Mogadishu: Images from the past" (https://mogadishuimages.wordpress.com/) e inclusa nell'Archivio Somalia con il consenso del curatore della collezione Rick Davies.Sawir laga soo qaatay mareegta "Mogadishu: Images from the past" (https://mogadishuimages.wordpress.com/), waxaana lagu biiriyay Kaydka Soomaaliya, kaddib markii oggolaasho laga helay qofka diyaariyay oo ah Rick Davies.Image taken from the website "Mogadishu: Images from the past" (https://mogadishuimages.wordpress.com/) and included in the Somali Archive with the permission of the owner of the collection, Mr. Davies
Behind Barbed Wire Fences: Higher Education and Twenty-first Century Teaching in Dadaab, Kenya
No full textThe article pays attention to the importance and the role of education in Africa, in particular it focuses on education in Dadaab refugee camp (Kenya) and education programs provided by international organizations.Maqaalkaani wuxuu ka hadlayaa muhimadda iyo dowrka ay wax barashadu ay ku leedahay Afrika, gaar ahaan wuxuu diiradda saarayaa arrinta waxbarashada sida midda xerada qaxootiga ee Dhadhaab (Kenya).L'articolo pone l'attenzione sull'importanza e il ruolo dell'istruzione in Africa, in particolare affronta il tema dell'educazione in contesti come quello del campo profughi di Dadaab in Kenya.Document provided by Bildhaan, Digital Commons at Macalester College.Dokumentigan waxaa dadka u soo bandhigay Bildhaan, Digital Commons jaamacadda "Macalester College".Documento messo a disposizione da Bildhaan, Digital Commons del Macalester College.Link: http://digitalcommons.macalester.edu/bildhaan
Orbis dictus – Dalle analisi lessicali all'elaborazione del linguaggio naturale. I nuovi algoritmi
No full textAlcuni degli aspetti importanti nell’educazione a distanza e tradizionale sono
l’individualizzazione e la motivazione. Si sono svolte e si svolgono molte ricerche al fine
di raggiungere un modello educativo affidabile in grado di garantire una fruttuosa
esperienza di apprendimento. Nella letteratura, alcune teorie sostengono che un sistema
generale possa essere applicato a ogni campo scientifico e sociale (General System
Theory), inclusa anche l’istruzione, altre teorie mettono l’istruzione in un altro livello, in
cui grazie all’integrazione di Set theory, Information theory, Graph theory e la General
Systems theory (SIGGS) si raggiunge un’esperienza conoscitiva migliore. A causa della
crescita dei sistemi educativi elettronici, alcune teorie sono state create per utilizzare gli
strumenti tecnologici disponibili, con l’obiettivo di creare un apprendimento dinamico che
cambi in modo da incontrare i bisogni dello studente e le sue abilità a vari livelli di
specificità (approcci educativi adattivi)
Questo lavoro introduce un nuovo modello educativo, il modello Orbis Dictus che ha
l’ambizioso intento di creare un multi-level model frame-work (modello di multilivelli). Il
modello Orbis Dictus è visto come un modello teorico e allo stesso tempo come una
piattaforma empirica e-learning adattiva, con alcune proposte di miglioramento attraverso
l’introduzione di alcuni algoritmi avanzati (trueskill, mixed chaining expert system e
predictive decision trees), e anche un lavoro di aggiornamento delle frequenze delle parole
nel Vocabolario Di Base di Tullio De Mauro, visto che l’ultimo aggiornamento è stato
fatto nel 2004, al fine di realizzare un miglioramento degli strumenti utilizzati nell’attuale
piattaforma Orbis Dictus verso una migliore esperienza di apprendimento degli studenti.
Il progetto di questa tesi nasce dalla osservazione degli strumenti sviluppati all’interno
della piattaforma Orbis Dictus, sviluppata all’interno del progetto nazionale am-learning, e
trovando dei limiti di tali strumenti, nella forma di parole con frequenze che non
rispecchiano la difficoltà di tali parole. Questo causa qualche scelta errata dalla parte degli
strumenti della piattaforma Orbis Dictus, e di conseguenza, occorre l’intervento umano
per correggere tali errori.
Possiamo minizzare l’intervento dell’essere umano nella creazione deelle parove a lacune
automatiche ? L’utilizzo dell’internet come fonte ,per ricalcolare le frequenze delle parole
nel Vocabolario Di Base di Di Mauro, potrebbe migliorare la scelta degli strumento per le
prove a lacune ? Quali strumenti potrebbero beneficiare dell’aggiornamento del
Vocabolario Di Base ?
L’internet, potrebbe essere una fonte per analizzare il linguaggio di base in questi giorni,
cone milioni e milioni di pagine Web create ogni giorno, questo potrebbe essere un modo
non solo per aggiornare il linguaggio di base, ma anche per monitorare e vedere il
cambiamento della lingua attraveerso il tempo.
Per realizzare uno strumento del genere, è necessario avere in attenta considerazione ciò
che rappresenta l’oggetto di studio e di elaborazione. Partendo dai dati raccolti dai siti
dove gli utenti contribuiscono alle pagine e gli articoli con dei commenti, altri siti come i
forum e i gruppi di discussione, i social network, e le notizie giornaliere, con l’attenzione
di non raccogliere lo stesso articolo di più di una volta (i duplicati).
Lo strumento è realizzato sviluppando dei piccoli software (Web Crawlers) che
raccolgono le pagine dei siti prescelti, e portano indietro le pagine intere al server creato
per tale obbiettivo, nel momento che le pagine vengono riportate al server, qualche
algoritmo per pulire le pagine dagli annunci, la struttura della pagine (html tags), e i
boilerplates (sono dei contenuti creati in automatico per tentare il visitatore a cliccare e
visitare un’altra pagine che gli potrebbe interessare). Una volta che le pagine raccolte
vengono pulite, rimane solo il testo, qui si intramette il lemmatizzatore, che porta la parola
al lemma. Una volta che abbiamo i lemmi, si calcolano l’occurenza di sciascuna parola, poi
si calcola la frequenza delle parole confronto al testo raccolto.
Affinché gli studi e le proposte in campo educativo possano indirizzarsi e svolgersi con
maggiore efficacia in un quadro schematico, occorre creare degli strumenti che consentano
l’aggiornamento del vocabolario di base. Il presente lavoro è teso proprio a reintrodurre
un fattore importante, che è l’utilizzo dei contributi degli utenti su internet per aggiornare
il vocabolario di base e monitorare il cambiamento della lingua attraverso il tempo, al fine
di migliorare l’esperienza educativa dello studente a distanza
Autovalutazione, valutazione esterna e miglioramento delle scuole: indagine sulle condizioni di successo nel contesto di un progetto pilota italiano
No full textNegli ultimi anni, nonostante le differenze esistenti, i sistemi educativi, specialmente quelli europei, sono stati caratterizzati da alcune dinamiche convergenti, tra cui l’estensione dell’autonomia scolastica e dell’uso della valutazione a molteplici livelli e per una pluralità di scopi. In questo contesto, l’attenzione è andata spostandosi verso la valutazione dei singoli istituti scolastici e, in particolare, verso il sostegno all’autovalutazione e la valorizzazione di essa nel processo di valutazione esterna. In Italia, nell’anno scolastico 2014/2015 sono state avviate a regime le attività del Sistema Nazionale di Valutazione (SNV). Al fine di identificare il modello valutativo sono state realizzate diverse sperimentazioni, tra cui il progetto Vales. Nonostante non esista un modello unico di valutazione delle scuole né a livello di politiche scolastiche internazionali, né nella letteratura, si è cercato di comprendere quali sono le condizioni che possono contribuire a realizzare un percorso di autovalutazione e di valutazione esterna con maggiori probabilità di successo in termini di efficacia e di condivisibilità. In collaborazione con il gruppo di ricerca dell’Invalsi dell’Area Valutazione delle scuole, è stato indagato il percorso realizzato nell’ambito del progetto pilota Vales mediante la somministrazione di un questionario rivolto a tutti i capi d’istituto delle scuole coinvolte nel progetto e un successivo approfondimento qualitativo, durante il quale sono state visitate alcune scuole, in cui sono state condotte interviste individuali con i loro dirigenti e focus group con i membri dei Nuclei di autovalutazione. I risultati indicano l’importanza dei seguenti aspetti: collaborazione e un ampio coinvolgimento dei vari attori all’interno e all’esterno delle scuole; accompagnamento concreto delle scuole con limitata esperienza nei processi di autovalutazione; organizzazione e comunicazione adeguate rispetto alle tempistiche delle attività valutative; competenza e apertura al dialogo dei valutatori esterni nel condurre le visite, interpretare le informazioni raccolte e fornire il feedback alla scuola
Il recupero della rete dei percorsi antichi per la "riattualizzazione" del territorio : azioni strategiche lungo la via Clodia nel paesaggio dell'Etruria meridionale interna
No full textIl ruolo dell’espressione della neuroglobina indotta da estrogeno nella neurodegenerazione e neuroprotezione
No full textSince its discovery, Neuroglobin (Ngb) has received great attention by the scientific community for its peculiar functions.
Even though it is a member of the globin family, Ngb displays a low degree of homology with other globins including Myoglobin (Mb) and Hemoglobin (Hb), only sharing with them the quaternary structure and the capability to bind to oxygen and other gaseous ligands. On the other hand, Ngb is a hexa-coordinated globin, whereas the other members of the globin family show a penta-coordination, index of a highest reactivity. Furthermore Ngb exhibits characteristic enzymatic properties.
Several works focused on the definition of Ngb functions, starting from its localization inside the cell. Although the molecular mechanism(s) involved is(are) yet matter of debate, as a whole Ngb is considered a protein whose over-expression results protective in the nervous system against a panel of pathologic conditions, including neurodegenerative diseases.
Recently our laboratory have reported that 17β-estradiol (E2), the most active between estrogens, is an endogenous modulator of Ngb. In fact, E2 is able to promote in several cells of the nervous system (i.e., hypothalamic neurons, astrocytes, human neuroblastoma cell lines), via ERβ, Ngb over-expression and binding to mitochondrial cytochrome c, a crucial event against oxidative stress-induced apoptosis.
E2 is a steroid hormone with pleiotropic effects on the entire organism playing roles that encompass from the control of reproductive functions to advanced cerebral functions. Estrogen receptors (ERs) are ligand activated transcription factors, so operating genomically, but also involved in rapid mechanisms, activated when they are localized at the plasma membrane. There are two estrogen receptors subtypes (i.e., ERα and ERβ), responsible for opposing functions and displaying a different expression pattern among tissues. To further complicate the picture, E2 finely tunes their expression, so modulating its effects in target cells. As an example, E2 promotes the cell proliferation via ERα, whereas ERβ activities are responsible for the apoptotic cell death. On the other hand, in the nervous system, both ERs activation is required for neuron survival. Thus, both receptor subtypes mediates the E2 neuroprotective and neurotrophic effects, working against a series of brain damages, as well as responsible for sexual differences in the onset of neurodegenerative disorders and the gravity of their symptoms.
Previous data obtained in our laboratory sustain the idea that one of the mechanisms by which E2 acts as a neuroprotective hormone is the promotion
of high Ngb level into mitochondria which, in turn, is fundamental for Ngb anti-apoptotic activity. In this thesis this idea has been further enlarged by characterizing E2-induced Ngb over-expression in mitochondria both in neuroprotection and in neurodegeneration. This information will be useful to better define the signaling pathways at the root of E2-induced Ngb over-expression that can be used to discover novel molecules able to maintain Ngb up-regulation avoiding the side effects linked to the E2 treatment. In particular, our project has been mainly focused in discovery the protein that could realize Ngb transport to mitochondria upon E2 stimulus.
For the first time it has been ascertained that E2 enhances Huntingtin (Htt) expression both in vitro (human neuroblastoma cells SK-N-BE) and in vivo (striatal and hippocampal rat tissues), thanks to rapid (i.e., Akt activation) and long-term (transcription) ERα-dependent pathways. Htt is a ubiquitous protein with several functions vital for the cell survival attributed to, and so also considered a neuroprotectant protein.
Htt involvement in anti-apoptotic E2/Ngb process has been verified by several steps: (i) E2 requires Htt to promote Ngb expression; (ii) Htt and Ngb interact, and this binding is strongly induced by E2; (iii) Htt realizes E2-induced Ngb transport from nucleus to mitochondria upon oxidative stress conditions; (iv) Htt is important for E2-induced and Ngb mediated cellular protection against apoptosis. These results allowed to define a novel neuroprotective axis (i.e., E2/Htt/Ngb), active under oxidative stress conditions.
In order to verify if this axis is active even under neurodegenerative conditions its existence in Huntington’s Disease (HD) models has been tested. HD is a neurodegenerative dominant autosomal pathology caused by a mutation in the Htt codifying gene. This mutation determines the development of an oversized glutamine tract (PolyQ) in the N-terminal region of Htt, so losing its physiological activities and also acquiring toxicity, hence resulting in the neurodegeneration for striatal neurons at the first, and other brain regions with the progression of pathology. Estrogenic induction of Htt expression levels is active only for the wild type form (wt) of the protein, whereas E2 effects were completely impaired in the hippocampus of 13 weeks old R6/2 transgenic mice and in the murine cell lines expressing mHtt (STHdhQ111 striatal cell line). Additionally, wtHtt is required for E2 promotion of its interaction with Ngb and for Ngb migration to mitochondria. As a consequence, the presence of mHtt also impairs the anti-apoptotic effect usually guaranteed by E2/Htt/Ngb axis, clearly inoperative under neurodegenerative conditions.
These results show that only the wt form of Htt takes part of the cellular defensive system elicited by E2, whereas upon mutation Htt loses these beneficial functions. Thus, the discovery of drugs able to increase Ngb levels in mitochondria, mimicking E2 effects, could be promising for the development of treatment of neurodegenerative diseases. This substance could so guarantee neuronal survival against neurodegenerative processes.
The screening involved compounds known from literature as Ngb inductors (i.e., valproic acid and cinnamic acid), natural estrogen-mimetic compounds (i.e., Resveratrol and Naringenin), the selective ERβ ligand dyarilpropionitrile (DPN), the brain neurotrophic factor BDNF and the environmental pollutant Bisphenol A (BPA).
Both Naringenin and DPN (specific ligands of ERβ) satisfy the research requests. Previous studies from literature pointed the therapeutically potential of ERs ligands, further supporting the results here reported indicating that DPN, selectively activating ERβ, enhances Ngb expression levels, without exerting any parallel influence on Htt levels, which requires ERα activation.
This induction is sufficient for the protection against programmed cell death upon oxidative stress, as Ngb over-expression is preserved.
The Ngb anti-apoptotic function has been attributed to various functions Ngb potentially exerts in different cellular sites. This is the reason why it has been evaluated Ngb localization consequent to DPN administration. Results show that DPN, like E2, carries Ngb to mitochondria without any Htt involvement, unlike E2.
As a whole, these data confirm the pivotal role played by Ngb in neuroprotective effects of E2, highlighting the importance of Ngb over-expression. In addition, the principal results obtained during this three year project were: (i) the discovery of a novel neuroprotective axis (i.e., E2/Htt/Ngb), active under oxidative stress conditions; (ii) the loss of this beneficial axis activities during neurodegeneration; (iii) the description of novel beneficial functions for Htt protein which are loss upon its mutation; (iv) the discovery that the activation of Htt/Ngb pathway is shared by several substances with neuroprotective effects; (v) the discovery that ERs activate diverse and parallel pathways to guarantee neuroprotection; and (vi) the identification of a compound that preserves E2/Ngb anti-apoptotic results (i.e., DPN) specifically activating only ERβ pathway.
As a whole, these data elucidate the role of E2-induced neuroglobin expression in neurodegeneration and neuroprotection opening a new avenues in the field of neurodegeneration treatment with the discovery of DPN protective action
Ruolo della transglutaminasi 2 nell’invecchiamento del tessuto nervoso
No full textTransglutaminases (TGs) are a nine members protein family, among which tissue transglutaminase (TG2) is unique for its multiple enzyme activities, ubiquitous expression, cellular localizations and physiological roles. Primary and best studied TG2 function is the Ca+2-dependent transamidating activity, which can result in protein cross-linking between a glutamine and a lysine residue (Iismaa et al., 2009). It is found throughout the body and highly expressed in many tissue, including the nervous one (Thomazy & Fesus, 1989; Chen & Mehta, 1999; Fesus & Piacentini, 2002; Siegel & Khosla, 2007). Within the brain, the enzyme is present in many regions including frontal and temporal cortex, hippocampus and cerebellum (Appelt et al., 1996; Johnson et al., 1997; Kim et al., 1999; Lesort et al., 1999, 2000; Andringa et al., 2004; Wilhelmus et al., 2008). It is primarily neuronal, but can be found in glia as well (Wilhelmus et al., 2008). Originally regarded as a cytosolic protein, TG2 was later found in other cell compartments, including the nucleus, mitochondria, endoplasmic reticulum, as well as in the extracellular space (Lesort et al., 1998; Piacentini et al., 2002; Verderio et al. 2003; Rodolfo et al., 2004; Mishra et al., 2006; Zemskov et al. 2006; Malorni et al., 2009; Szegezdi et al., 2009; Piacentini et al., 2011, Caccamo et al., 2012; Gundemir et al., 2012; Piacentini et al., 2014). Given the ubiquitous expression and vast array of enzymatic and non-enzymatic TG2 activities, it is not surprising that this protein is intimately involved in the regulation of numerous functions, including cell survival and apoptosis (Fesus & Szondy, 2005; Mehta et al., 2006; Verma & Mehta, 2007), autophagy (Mastroberardino & Piacentini, 2010), inflammation (Caccamo et al., 2005b, c; Takano et al., 2010) and oxidative stress processes (Fesus & Szondy 2005; Caccamo et al., 2012). The observed increase of mRNA levels during normal aging and TG2 role in apoptosis, autophagy, ROS imbalance e inflammation create a direct link with the ageing process. Thus it is certain that there are grounds for TG2 to become a new therapeutic target in many age-related diseases in which TG2 contribution has been long described: for instance, cardiovascular disease (Sane et al., 2007), cancer pathology (Budillon et al., 2013), hepatic disease (Nardacci et al., 2003) and age-related neurodegenerative disease, including HD, PD, AD (Jeitner et al., 2009).
Given its involvement in neural cell homeostatic pathways, my PhD project aimed at characterizing the TG2 in vivo contribution to mechanisms such as autophagy and antioxidant defense, and how these processes are modulated in
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the different brain areas and during normal ageing. This was achieved by studying a knockout mouse model, generated by De Laurenzi & Melino in 2001, carrying a homologous recombination to replace the region of the TG2 gene encoding its catalytic site with the neomycin resistance gene.
The main results obtained from the research and described in this thesis can be summarized as follows:
1. Our data provided in vivo evidence of a negative modulatory role of TG2 in the induction phase of autophagy, so far only supported by in vitro literature (Akar et al., 2007; Ozpolat et al., 2007; Luciani et al., 2010) Noteworthy, induction of autophagy in TG2-/- mouse brain appears not to be followed by successful completion of the process. This statement is mainly supported by electron microscopic findings concerning (i) accumulation in TG2-/- mouse brain of mitochondria/lipofuscin aggregates, index of decreased lysosomal degradation, (ii) presence of intracellular “myelin figures”, reminiscent of residual autophagic bodies, and (iii) deranged Golgi apparatus, sign of lysosomal disturbed biogenesis.
2. Our ultrastructural results highlighted profound alterations of the mitochondrial compartment subsequent to TG2 ablation, consistent with the role of the enzyme in stabilizing complex I and II of the electron respiratory chain (Malorni et al., 2009). Mitochondrial impairment likely leads to superoxide anion leakage, whose accumulation appear aggravated by the decreased expression of its major scavenger SOD2.
3. Our data pointed out that there are brain region-based differences in coping with TG2 ablation. Indeed, neocortex and, partly, the hippocampal formation, regions where ROS detoxifying enzymes are downregulated, are oxidative stress prone areas. By contrast, cerebellar area, long known to be a more protected region of the brain in many neurodegenerative diseases, displays less damaged mitochondria in TG2-/- mice. This could relate to an efficient activation of the antioxidant systems – indeed we detected higher expression of H2O2 metabolizing enzymes CAT and GPx 1/2- and/or to a higher autophagic flux.
4. Response to cellular stress caused by TG2 ablation apparently involves peroxisomes, which are biogenetically induced, possibly to cope with mitochondrial deficiency, as it occurs in other pathophysiological situations.
5. Our data clearly show that any attempt by the cell to counteract cell injury consequent to TG2 ablation, is subject to progressive loss of efficiency when
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senescence ensues. When comparatively analyzing results from 12- and 24-month-old mice, a worsening of antioxidant defences and autophagic efficiency, associated with ultrastructural damage is detected, even in regions (cerebellum) more resistant to insult.
Our study, by providing novel insights into previously suggested TG2 roles in the brain, and especially by highlighting new functions of the protein in the complex organ, opens the way to future mechanistic investigations, which will hopefully lead to therapeutic applications
Softcomputing Techniques on Embedded Systems for Industrial Engineering and Information Technology
No full textThis dissertation documents a research on e cient Soft Computing tech-
niques on Embedded Systems. The study begins with an analysis of the
numerical techniques that constitutes the state of the art of practical Soft
Computing, identifying in the Arti cial Neural Networks and the Non-linear
Optimization Algorithms the most interesting techniques to develop in em-
bedded environment. A comprehensive foundation of the theoretical aspects
involving these topics, and a documented review of the techniques used in
practical engineering scenarios is described in the rst part of the disserta-
tion. The topics investigated involves: Advanced Arti cial Neural Network
Architectures, Enhanced Generalization Sizing Techniques, First and Second
Order Training Algorithms, Non-Linear Optimization problems, Evolution-
ary and Swarm Intelligence Algorithms, Local Search Techniques and Hybrid
Optimization Algorithms.
The problem of embedded implementation of Arti cial Neural Networks,
and the optimization algorithms involved for their training, is described in
the second part of the dissertation. First, an overview of the most interesting
embedded devices available for this techniques implementation is presented.
Following, an analysis on the performance, accuracy and memory footprint
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for neural techniques is presented. Two aspects where considered in the anal-
ysis: the numerical approximations of the non-linear activation function , and
the algorithmic e ciency of the linear operations. The topics investigated
involved: Numerical Approximation of the Activation Function, Microcon-
troller Optimization of the Resources, FPGA based Hardware Accelerators
for Floating-Point Operations and Vector-Matrix Multiplication.
The nal part of this dissertation describes the scenarios where the devel-
oped techniques were used. The applications were divided in speci c elds.
The rst regards the control of a Photovoltaic System operating-point for
the extraction of the maximum power, referred as Maximum Power Point
Tracking. The second describes the assessment of the Solar Irradiance from
indirect measurements on PV devices, and the prediction of its future value
using Recurrent Neural Networks. The third is inherent to an Inverse Biome-
chanical Problem relative to the estimation of the muscle load of an cyclist
using kinematic and dynamic measurements from an instrumental pedal
Design of a robotic rehabilitation hand for optimal grasping
No full textBuilding robotic devices able to replicate the human behavior to obtain motor recovery,
functional substitution or human-robot interaction as human-like as possible, is becoming increasingly popular. In the last past years several robotic rehabilitation devices demonstrate how they can improve the performance of the rehabilitation therapy performed by a human therapist in terms of action repetition and accurate tracking of the desired trajectory. A proliferation of robotic devices for gait rehabilitation applications
have been manufactured. Most of them may be intimidating to patients, others may
require long and involved patient setups. Using a human-like robotic device, such as a
robotic arm and a robotic hand, may be fruitful. Starting with the use of a multipurpose
robotic arm to be attach to the human leg to automate gait training and relieve the
physical burdens placed upon therapists, we design a mechanism able to attach the robot arm to a human limb, in a fast and safety way. Afters studying grasping in industrial robot we developed a new robotic hand to be used with the robotic rehabilitation device: the Easyhand, a small. light, easy to build and to control robotic hand to be adapt to use with the multipurpose robotic arm to be attached to the human leg. This dissertation present a the design of a new robotic hand for optimal grasping in rehabilitation field
Models and algorithms for the real-time railway and air traffic flow management problems
No full textPublic transport systems with high capacity and high speed, such as railways and air traffic,
efficiently address the ever increasing transport demand, reducing road congestions on
highways and in densely populated areas. Building new infrastructures is a difficult task,
due to high costs and physical obstacles, thus pushing infrastructure managers to better use
the already existing ones. Utilization plans are carefully designed, however disturbances
may arise, creating time-overlapping conflicting request done by multiple vehicles on the
same resources that the dispatchers are required to address. Limited automated system aid is
provided to the dispatchers which, due to the limited time available, are not allowed to fully
evaluate the effect of the recovery decisions taken. Some decisions may lead to future
delays, which in turn may create new conflicting requests, in a snowball effect.
Optimization is thus necessary to minimizing the delay propagation and the consequential
worsening of the quality of the service offered. This PhD thesis investigates how operations
research models and algorithms benefit the solution process of the real-time railway and air
traffic flow management problems. The railway traffic management problem consists in
detecting and solving conflicting track requests done by multiple trains and creating a
recovery plan in which each track is used by at most one train at a time and no deadlock
exists in the network. The air traffic flow management problem deals with the assignment of
an entry time to each landing and take-off aircraft in each resource the aircraft requires to
traverse in such a way that potential conflicts between single aircraft are efficiently solved
and all aircraft respect the minimum longitudinal and diagonal safety distances. In order to
incorporate safety regulations constraints, both problems require a microscopical level of
detail. This is achieved through the use of the alternative graph model. This model has
already been proved successful for the railway case and thus is here applied to the air traffic
one. Algorithms improving the performance of the state-of-the-art AGLIBRARY
optimization solver (a set of operations research based models and algorithms for complex
practical scheduling problems) are proposed. Furthermore, the thesis deals with large test
cases in terms of size of the network studied, time of prediction considered and number of
available alternative routings for each vehicle. Search space restriction and decomposition
methods are analyzed in order to simplify the solution process of the problems when such
large cases are considered. Also, lacking generally recognized objective functions both for
the railway and the air traffic management problems, the gaps between solutions optimized
and evaluated with different performance indicators are analyzed, together with possible
ideas on how to combine multiple performance indicators when required. Different test beds
have been taken into consideration for both problems. The instances considered are of
practical size and affected by different disturbances, such as initial delays and infrastructure
disruptions