Comunicazioni sicure su canali eterogenei: un'analisi sistematica di SSL da Java a Jolie

All’interno di questa tesi è stata affrontata la tematica della realizzazione di comuni- cazioni sicure, in modo da ottenere l'indipendenza di queste ultime dal canale utilizzato, con l'ausilio di strumenti in grado di fornire supporto per la creazione di applicativi orientati allo scambio di dati e messaggi, quali i linguaggi di programmazione Java e Jolie, il quale è basato sul precedente. Sono state inizialmente analizzate le principali caratteristiche e le problematiche più importanti che è necessario dover risolvere in modo da poter arrivare al risultato desiderato. Successivamente, è stato dato un ampio sguardo ad una delle scienze più applicate per risolvere i problemi tipici che affliggono questo tipo di comunicazioni, la crittografia. Sono stati elencati gli strumenti messi a disposizione ed il loro funzionamento. La crittografia viene poi applicata al protocollo SSL, il quale rappresenta la soluzione maggiormente diffusa, sia sul Web che in altri ambiti, per proteggere le informazioni personali che transitano tra gli end-point di una comunicazione. Sono state elencate le principali caratteristiche, alcuni cenni riguardanti la nascita e lo sviluppo ed è stato descritto il funzionamento di questo protocollo, soprattutto per quanto riguarda la sua fase preliminare, che è una delle parti che lo caratterizzano maggiormente. In seguito, è stata analizzata la soluzione fornita all’interno delle librerie del linguaggio Java per realizzare comunicazioni indipendenti dal mezzo di comunicazione che soddisfino le politiche dettate dal protocollo SSL. Questa soluzione è rappresentata dalla classe SSLEngine, che è quindi stata esaminata, a partire dal ciclo di vita e dall'inizializzazione, fino ad arrivare all'interazione all'interno di un applicazione. Quanto esplorato in precedenza viene poi applicato a Jolie, un linguaggio di programmazione basato sulle comunicazioni e sviluppato in Java, all'interno dell'Università di Bologna. Dopo uno sguardo generale alle sue caratteristiche è stata approfondita la gestione dei protocolli, e di conseguenza, l'introduzione di SSL all'interno di essi, realizzata tramite la classe SSLProtocol. Questa classe contiene ed implementa i concetti analizzati nel capitolo riguardante Java, adattandoli all'architettura ed alla progettazione pensata appositamente per Jolie; è stata quindi effettuata un'analisi del codice e della gestione della classe SSLEngine per realizzare comunicazioni sicure. Infine, per verificare l’effettivo funzionamento, sono stati creati due semplici casi d’uso per poter sfruttare i vantaggi offerti da Jolie, il quale è particolarmente indicato per la creazione di applicazioni orientate ai servizi

Studio preliminare della dinamica libera e delle qualita' di volo della configurazione Prandtlplane

L'obbiettivo di questa tesi consiste nello sviluppo di un programma di dimensionamento aeromeccanico preliminare di un generico velivolo con configurazione Prandtlplane. Il programma ricevendo in input dati geometrici ed inerziali da altri programmi sviluppati per lo studio della medesima configurazione deve stabilire le dimensioni delle superci di controllo per ottenere le volute caratteristiche di controllabilita', manovrabilita' ed il soddisfacimento delle qualita' di volo, inoltre il programma deve anche dare indicazioni sulla stabilita' e le caratteristiche di volo non legate al dimensionamento dei comandi al fine di ottenere livelli di qualita' di volo accettabili. Parallelamente a questo obbiettivo la tesi ha anche scopo di studiare con maggior dettaglio rispetto ai lavori precedenti, anche se solo dal punto di vista teorico, le peculiarita' della dinamica della configurazione Prandtlplane e valutare la loro influenza sulle caratteristiche di volo

Rheological characterisation of sludge coming from a wastewater treatment plant

The aim of this study was that of studying the rheology of sewage sludge using two different rheological test protocols taken from literature and comparing them in order to evaluate which useful information are given from every protocol. Approach: Two different protocols have been used taking particularly into account the problems connected to sludge heterogeneous composition and to the interaction between solid-solid and solid-water particles in order to completely understand the rheological behavior of this suspension; moreover, the consequences of particular effects connected to test geometry and conditions have been considered. Two fundamental parameters have been modified in the samples: The total solids content and the polyelectrolyte addition. Sludge with 3 and 5% of total solids have been investigated, with or without polyelectrolyte using also microscope analysis to understand the effect of polyelectrolyte on the sludge. Results: As expected, it was noticed that sludge viscosity grows up increasing the total solids content and with the presence of polyelectrolyte. The effect of polyelectrolyte is that of separating the liquid-phase from the solid-phase of the sludge giving a more space-heterogeneous suspension with higher viscosity and higher non-Newtonian behavior. Conclusion: This study proved that combining two different protocols of analysis can be useful to furnish important and complementary information on sludge rheology especially when some parameters change from sample to sample. Moreover, in order to have good and consistent results, it is necessary to use particular attention on samples pretreatment

Determination of Crumb Rubber Content of Asphalt Rubber Binders

The study focused on two new laboratory procedures developed for the determination of crumb rubber content of asphalt rubber binders. The first methodology was on the basis of the comparative analysis of cobalt and antimony content of base bitumen, crumb rubber, and asphalt rubber. The second was on the basis of the analysis of combustion products of asphalt rubber binders and of their components. Investigations were performed on binders prepared in the laboratory or sampled at production plants during pavement rehabilitation works. Obtained results were encouraging because it was found that both procedures were characterized by satisfactory levels of accuracy and precision

Behavioral and Neurophysiological Effects of Transdermal Rotigotine in Atypical Parkinsonism

Effective therapies for the so-called atypical parkinsonian syndrome (APS) such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal syndrome (CBS) are not available. Dopamine agonists (DA) are not often used in APS because of inefficacy and in a minority of case, their side effects, like dyskinesias, impairment of extrapyramidal symptoms or the appearance of psychosis, and REM sleep behavioral disorders (RBD). Transdermal rotigotine (RTG) is a non-ergot dopamine agonist indicated for use in early and advanced Parkinson’s disease with a good tolerability and safety. Moreover, its action on a wide range of dopamine receptors, D1, D2, D3, unlike other DA, could make it a good option in APS, where a massive dopamine cell loss is documented. In this pilot, observational open-label study we evaluate the efficacy and tolerability of RTG in patients affected by APS. Thirty-two subjects with diagnosis of APS were treated with transdermal RTG. APS diagnosis was: MSA parkinsonian type (MSA-P), MSA cerebellar type (MSA-C), PSP, and CBS. Patients were evaluated by UPDRS-III, neuropsychiatric inventory, mini mental state examination at baseline, and after 6, 12, and 18 months. The titration schedule was maintained very flexible, searching the major clinical effect and the minor possible adverse events (AEs) at each visit. AEs were recorded. APS patients treated with RTG show an overall decrease of UPDRS-III scores without increasing behavioral disturbances. Only three patients were dropped out of the study. Main AEs were hypotension, nausea, vomiting, drowsiness, and tachycardia. The electroencephalographic recording power spectra analysis shows a decrease of theta and an increase of low alpha power. In conclusion, transdermal RTG seems to be effective and well tolerated in APS patients

Comparison of the effects of transdermal and oral rivastigmine on cognitive function and EEG markers in patients with Alzheimer’s disease

Background: Alzheimer's disease (AD) is the most common cause of dementia in older patients. Rivastigmine (RV, Exelon®, Novartis), a reversible cholinesterase inhibitor, improves clinical manifestations of AD and may enhance ACh-modulated electroencephalogram (EEG) alpha frequency. This pilot study aimed to determine the effects of two formulations of RV (transdermal patch [TV-RDP] and oral capsules [TV-CP]) on alpha frequency, in particular the posterior dominant rhythm, and cognitive function (assessed by the Mini-Mental State Examination [MMSE]) in patients with AD.Methods: Subjects with AD were assigned to receive either RV-TDP 10 cm2 or RV-CP 12 mg/day. All patients underwent EEG recordings at the beginning and end of the 18-month study period using P3, P4, O1 and O2 electrodes, each at high (10.5–13.0 Hz) and low (8.0–10.5 Hz) frequency. MMSE scores were determined at the start of the study (T0) and at three successive 6-month intervals (T1, T2 and T3).Results: RV-TDP administration (n=10) maintained cognitive function as evidenced by stable MMSE scores from baseline to 18 months (21.07 ± 2.4 to 21.2 ± 3.1) compared with a decrease in MMSE score with RV-CP (n=10) over 18 months (18.3 ± 3.6 to 13.6 ± 5.06 [adjusted for covariates p=0.006]). MMSE scores were significantly different between treatment groups from 6 months (p=0.04). RV-TDP also increased the spectral power of alpha waves in the posterior region measured with electrode P3 in a significantly great percentage of patients than TV-CP from baseline to 18 months; 80% versus 30%, respectively (p=0.025 [χ2 test]).Conclusion: RV-TDP was associated with a greater proportion of patients with increased posterior region alpha wave spectral power and significantly higher cognitive function at 18 months, compared with RV-CP treatment. Our findings suggest that RV-TDP provides an effective long-term management option in patients with AD compared with oral RV-CP. This study is a pilot, open-label study with

Anatomical Substrate and Scalp EEG Markers are Correlated in Subjects with Cognitive Impairment and Alzheimer's Disease

Dementia is a syndromic diagnosis, encompassing various stage of severity and different anatomo-physiological substrates. The hippocampus is one of the first and most affected brain regions affected by both Alzheimer's disease (AD) and mild cognitive impairment (MCI). Moreover, chronic cerebrovascular disease (CVD) is one of the major risk factor for developing dementia. Recent studies have demonstrated different relationship between the anatomical substrate and scalp electroencephalography (EEG) markers. Indeed, modifications of EEG rhythmicity is not proportional to the hippocampal atrophy, whereas changes in EEG activity are directly proportional to the load of subcortical CVD. The computation of the EEG spectral power and the analysis of the functional coupling of brain areas, through linear coherence, are two of the most known processing methods in EEG research. Two specific EEG markers, theta/gamma and alpha3/alpha2 frequency ratio have been reliable associated to the atrophy of amygdalo–hippocampal complex. Moreover, theta/gamma ratio has been related to MCI conversion in dementia and alpha3/alpha2 ratio has been specifically related to MCI conversion in AD. The functional coupling of brain areas is also modulated by hippocampal atrophy. In the MCI subjects, hippocampal atrophy is linked to an increase of interhemispheric coherence seen on frontal and temporal regions whereas subcortical CVD is linked to a decrease of coherence in fronto-parietal regions. In the present study the most significant results of recent studies on correlation between scalp EEG, cognitive decline, and anatomical substrate have been reviewed, with particular attention to the relationships between EEG changes and hippocampal atrophy. The following review is not intended to provide a comprehensive summary of the literature. Rather it identifies and discusses selected studies that are designed to find the specific correlation between scalp EEG markers and anatomo-pathological substrate. The principal aim is to propose a plausible neurophysiological theoretical model of the cognitive decline as mirrored by both structural and functional tools of research

Chromitite petrogenesis in the mantle section of the Ballantrae Ophiolite Complex (Scotland)

5siPodiform chromitites from the Ballantrae Ophiolite Complex (BOC), NW Scotland, are examined to investigate their petrogenesis and elucidate the nature of melt percolation in the supra-subduction zone oceanic mantle more generally. The mantle portion of the BOC comprises two petrologically distinct serpentinite belts, whose differences have previously been attributed to contrasting degrees of melt extraction. Chromitite occurs in each of the northern and southern serpentinite belts, at Pinbain Bridge and Poundland Burn, respectively. Field relationships suggest that chromitites were formed by melt-rock reaction in channel-like conduits in the upper mantle. Chromitite Cr-spinel compositions from the two localities show marked differences to one another, with the Pinbain Bridge chromitite Cr-spinels being characterised by relatively high Cr# [Cr/(Cr+Al); 0.62-0.65] and lower abundances of certain trace elements (e.g., Ti, Ga, V), whereas the Poundland Burn chromitite Cr-spinels exhibit relatively low Cr# (0.44-0.46) and higher concentrations of these trace elements. The contrasting Cr-spinel compositions are used to estimate parental magma compositions for the chromitites; the Pinbain Bridge chromitites crystallised from magmas resembling arc tholeiites whereas MORB-like magmas were involved in formation of the Poundland Burn chromitites. While it is possible that this dichotomy points to early derivation of the BOC at a MORB spreading centre, with subsequent processing in a supra-subduction zone, we suggest that the differences reflect melt extraction from different parts of an evolving subduction zone, such that the MORB-like magmas were generated in a back-arc setting. This interpretation finds support in the Ti/Fe3# versus Ga/Fe3# systematics of peridotite-hosted accessory Cr-spinel that we present here, as well as previously published trace element data and geochronological constraints on the basalt lava sequences associated with the BOC, which collectively favour formation of the Poundland Burn chromitites in subduction zone mantle.partially_openembargoed_20210616Derbyshire, EJ, O’Driscoll, B, Lenaz, D, Zanetti, A, Gertisser, RDerbyshire, Ej; O’Driscoll, B; Lenaz, D; Zanetti, A; Gertisser,