Studio e progetto di un sistema di controllo per sospensioni adattive di un motoveicolo

Studio e progetto di un sistema di controllo per sospensioni adattive di un motoveicolo Sommario In questa tesi viene presentato il progetto di un sistema di controllo per le sospensioni adattive di un motoveicolo. Il sistema distingue quattro tipologie di strada e in base a queste adatta il coefficiente di smorzamento della sospensione posteriore per migliorare il VTV(Vibration Total Value) . È costituito da un nodo di una rete CAN e da una semplice rete per l’acquisizione del segnale di ingresso. La descrizione del nodo è stata eseguita sia a livello hardware che firmware. È stato infine utilizzato un semplice modello Simulink per effettuare una stima dei miglioramenti ottenibili in termini di VTV

Structural investigation of gp36-MPER in membrane mimicking systems

2017 - 2018FIV is a lentivirus that resembles the Human Immunodeficiency Virus (HIV). The lentiviral envelope glycoproteins (gp41 in HIV and gp36 in FIV) mediate virus entry by interacting with specific receptors present at the cell surface. Increasing evidences suggest a common structural framework for these glycoproteins, corresponding to similar roles in virus cell fusion. During the virus entry a conformational transition occurs in the glycoproteins to form a stable six-helical bundle. In this conformational arrangement, the correct assembly with the membrane of a tryptophan (Trp) rich region named membrane proximal external region (MPER) leads to the fusion of virus envelope and host cell membrane. The design of molecules inhibiting the correct positioning of MPER on the membrane is currently a strategy for the design of virus entry inhibitors. C8, a Trp-rich fragment of gp36-MPER, was identified as an antiviral compound inhibiting the entry of FIV into the host cell. C8 showed remarkable membrane binding property, inducing alteration of the phospholipid bilayer and membrane fusion. In this context, part of my PhD thesis is focused on the study of C8/lipid membrane interaction employing a multiscale approach based on spectroscopic experiments, molecular dynamics simulations and confocal microscopy imaging. Our results show that the peptide is active on zwitterionic lipid environment in which it induces a structural reorganization of the phospholipid bilayer that finally leads to the formation of membrane tubules. The presence and the position of Trp residues in C8 are important for antiviral activity: the C8 derivative C6a, obtained by truncating the N-terminal 770Trp-Glu771 residues, exhibits conserved antiviral activity, while the C8 derivative C6b, derived from the truncation of the C-terminal 776Trp-Ile777, is nearly inactive. To elucidate the structural factors that induce the different activity profiles of C6a and C6b, in spite of their similarity, in the second part of my PhD thesis I performed the study of structural behaviour of the two peptides in membrane mimicking environments using an analytical approach very similar to that employed for C8 peptide. I analysed C6a and C6b using CD and NMR spectroscopy, and confocal microscopy imaging. These data provide evidence that common antiviral activity profiles correspond to similar membrane binding properties: actually C6a, similarly to C8, has the ability to destabilize membrane vesicles, producing complex network of membrane tubes. Eventually, I analyzed structural behavior of the full gp36-CHR-MPER in a set of membrane models characterized by increased complexity: micelles, multilamellar vesicles and cellular vesicles. Analyses with paramagnetic probes and confocal microscopy indicate that gp36-CHR-MPER and its derivatives are active on each of the mentioned bio-membrane systems, thus indicating that their impact on the size and shape is not a biophysical artefact, but an effect of biological relevance. [edited by Author]XXXI cicl

Vettori virali influenzali contenenti determinanti antigenici di HIV-1 inducono immunità protettiva nei topi dopo singola immunizzazione per via mucosale

Lo sviluppo di un vaccino efficace contro il virus dell’HIV-1 è una delle più importanti sfide che la Sanità pubblica sta affrontando in questi ultimi 20 anni. Una conoscenza ancora incompleta dei correlati di protezione e la variabilità genetica del virus HIV pone sostanziali impedimenti al raggiungimento di questo obiettivo. L’infezione dal virus HIV-1 si acquisisce prevalentemente attraverso la mucosa del tratto genito-rettale, pertanto, l’induzione di un’immunità mucosale rappresenta uno degli obiettivi primari nelle strategie che mirano a definire un efficace vaccino per il virus HIV-1. In particolare, un’immunizzazione in grado di attivare una risposta sia cellulare che umorale nelle mucose coinvolte nei processi di acquisizione del virus o dei linfonodi regionali può rappresentare una strategia efficace di prevenzione o controllo della replicazione e diffusione del virus dal sito di ingresso, ai tessuti linfoidi e al sangue. Numerose osservazioni suggeriscono il ruolo importante che i linfociti T CD8+ svolgono nel contenimento dell’infezione con il virus HIV-1, tra queste l’evidenza dell’associazione temporale tra la comparsa di una risposta mediata dai linfociti T HIV-specifici in seguito all’infezione acuta e la riduzione della replicazione virale ad un livello stabile (set-point), l’associazione significativa di particolari alleli MHC I con la protezione dalla progressione della malattia, e l’aumento della replicazione virale in seguito alla deplezione dei linfociti T CD8+ in modelli di studio macachi/HIV-1. Diverse strategie vaccinali nei confronti del virus HIV-1 si basano sull’impiego di protocolli di “prime-boost” in grado di indurre un aumento selettivo di linfociti T della memoria specifici per antigeni del virus HIV trasportati da vettori. Tra i diversi sistemi di trasporto e rilascio di antigeni, i vettori virali vivi ricombinanti sono ampiamente considerati, poiché hanno la capacità di attivare una forte risposta cellulare ed anticorpale nei confronti degli antigeni che esprimono. Il virus influenzale ricombinante, che esprime antigeni estranei provenienti dal virus HIV-1, è uno strumento promettente in tal senso. Alla luce di tali premesse abbiamo ritenuto interessante valutare la capacità di un virus influenzale di tipo A che esprime un poliepitopo HIV fuso all’estremità N-terminale della emagglutinina (HA) matura, di indurre una risposta immunitaria cellulare e umorale in seguito all’infezione di topi BALB/c per via vaginale e di conferire protezione nei confronti di un’infezione secondaria con i virus Vaccinia ricombinanti che esprimono gli stessi antigeni. In particolare abbiamo generato un virus influenzale ricombinante dal fenotipo attenuato (WSN/CKG), che esprime il peptide cluster PCLUS3, derivato dalla glicoproteina gp120 di HIV-1, il peptide P18IIIB, epitopo per i linfociti T citotossici (CTL) derivato dal loop V3 della gp120 di HIV-1 IIIB, e un secondo epitopo CTL derivato dalla proteina Gag di HIV-1, nella regione N-terminale del virus A/WSN/CKG. Mediante saggi ELISPOT, abbiamo osservato che una singola somministrazione per via vaginale con il virus WSN/CKG, induce nei topi una risposta immune a lungo termine mediata da linfociti T CD8+ antigene-specifici, nei linfonodi iliaci (ILN) drenanti la mucosa genito-rettale, e nella milza dei topi infettati, con un picco intorno al settimo giorno dopo l’infezione, che viene rapidamente richiamata nella milza in seguito ad un’infezione secondaria con il virus Vaccinia esprimente la proteina Env (vPE16) o Gag (vDK1). Tali risultati sono analoghi se i topi vengono immunizzati per via intranasale. Abbiamo poi analizzato mediante saggi ELISA la produzione di anticorpi antigene-specifici nel siero di topi ad un mese dall’infezione con il virus WSN/CKG e abbiamo osservato elevati livelli di IgG P18IIIB-specifiche nei topi che sono stati infettati sia per via intranasale che vaginale. L’immunità indotta attraverso l’infezione con il virus WSN/CKG è, inoltre, in grado di conferire protezione ai topi contro un’infezione secondaria con il virus Vaccinia ricombinante vPE16. I dati che abbiamo ottenuto complessivamente dal nostro studio indicano che un’immunizzazione mucosale, ed in particolare, un’immunizzazione per via vaginale, con un virus influenzale ricombinante che esprime un poliepitopo derivante dal virus HIV-1 può indurre nei topi una risposta immunitaria antigene-specifica, protettiva e a lungo termine.The development of an efficacious HIV vaccine is one of the world’s greatest public-health challenges. The poor understanding of immune correlates of protection and the widespread genetic diversity of the virus pose substantial scientific hurdles. HIV infection is a mucosal acquired disease. Therefore, mucosal immune responses might function as a first line of defense against viral infection, and the development of vaccines against HIV-1 able to elicit mucosal immunity is a high priority. In particular, immunization targeting local mucosal surfaces or the regional lymph nodes to elicit both humoral and cellular specific immune responses may present a strategy for preventing or controlling HIV-1 replication. A number of clinical and experimental observations suggest that CD8+ T cells play an important role in the containment of HIV-1 infection. These include evidence of the temporal association between the appearance of HIV-specific CD8+ T cell responses following acute infection and the reduction in viral replication to set-point, the significant association of particular MHC class I alleles with protection from HIV-1 disease progression, and the increase in viral replication following depletion of CD8+ cells in the macaque model of AIDS virus infection. Several vaccine strategies depend on prime-boost protocols that produce a selective increase of memory T cells specific for the HIV antigen carried by vectors. Among the different antigen delivery systems, live recombinant viral vectors have the capacity of inducing strong cellular immune responses and can also prime antibody responses against expressed foreign antigens. In particular, recombinant influenza viruses engineered to express HIV-1 antigens represent promising tools to elicit both mucosal and systemic immune responses against HIV-1. Therefore, we generated a recombinant Influenza A virus (WSN/CKG) expressing the peptide cluster PCLUS3, derived from the gp120 of HIV-1, the P18IIIB cytotoxic T-lymphocyte (CTL) epitope derived from the V3 loop of HIV-1 IIIB gp120, and a second CTL epitope derived from Gag of HIV-1, fused to the N-terminal end of mature HA of A/WSN/33 virus. Then, we determined the capacity of WSN/CKG virus to induce antigen-specific mucosal and systemic immune responses upon intranasal or vaginal infection of progesterone-treated mice, and to provide protection against challenge with recombinant Vaccinia viruses, expressing Env (vPE16) or Gag (vDK1) proteins from HIV-1. We observed that a single vaginal inoculation of mice with WSN/CKG virus elicited antigen-specific CD8+ T cells, in the spleen and iliac lymph nodes (ILNs) draining the genitorectal mucosa, that peaked around day 7 postinfection, and that were rapidly recalled in the spleen upon intraperitoneal challenge with the recombinant Vaccinia viruses vPE16 and vDK1. These results were similar to those observed in mice primed intranasally with WSN/CKG virus. We therefore measured V3 loop-specific antibodies in serum samples of mice at 1 month post single immunization with WSN/CKG virus, and we observed significant levels of P18IIIB-specific IgG in mice receiving virus either by vaginal or intranasal route. Finally, we provide evidence that immune responses induced by WSN/CKG virus in the mucosal and systemic lymphoid compartments result in protection against systemic vPE16 virus challenge. Overall, these results indicate that mucosal immunization and, in particular, local vaginal immunization with recombinant Influenza viruses can provide protective and durable specific immune responses in mice

mid term surgical results of proximal ulnar and radial fracture dislocations classified and treated with a new comprehensive classification system

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Environmental and economic assessment of sustainability in Mediterranean wheat production

ArticleThis study proposes the application of the Life Cycle Assessment (LCA) and economic evaluations conducted on different cereal production systems in semi-arid environments. Two different crop management systems of durum wheat were analysed by distinguishing Continuous Cropping (CC) and Crop Rotation (CR) with vetch, that are conducted through two different levels of crop intensification (in terms of tillage and fertilization strategies): Conventional (Conv) and Conservative (Cons). The resulting four scenarios were examined using LCA methodology to assess the environmental impacts, and the Production Cost (PC) analysis to estimate the economic results. Overall, the findings of this research provide an opportunity to identify sustainable crops management strategies

A systematic and critical review of life cycle approaches to assess circular economy pathways in the agri-food sector

This study provides a literature review of life cycle approaches used to assess circular economy (CE) pathways in the agri-food sector. The scope of this review is to understand how and how much the LC-based analysis is useful to evaluate if CE strategies are more sustainable than linear/traditional economic models in agri-food production systems. To carry out the systematic and critical literature review the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol was employed. The literature search was performed employing scientific databases (Scopus and Web of Science). The results highlight that 52 case studies out of 84 (62% of the total) use stand-alone life cycle assessment (LCA) to evaluate the benefits/impacts of circular economy strategies. Only eight studies (9.5%) deal with the life cycle costing (LCC) approach combined with other analyses, while no paper deals with the social life cycle assessment (S-LCA) methodology. We argue that experts in life cycle methodologies must strive to adopt some key elements to ensure that the results obtained fit perfectly with the measurements of circularity and that these can even be largely based on a common basis

The assessment of hazelnut mechanical harvesting productivity

ArticleHazelnut cultivation represents a new opportunity for Calabrian mountainous and sloping areas (Southern Italy), where no alternative fruit crops, except forestry, could be settled. In this Region, hazelnut production doubled during the last fifty years, inciting the farmers to introduce mechanization in cropping practices such as harvesting in order to increase productivity and decrease production costs. Indeed, harvesting is currently one of the most expensive processes of the productive cycle, moreover to be time consuming if carried out manually. Mechanization degree depends significantly on the terrain topography: in sloping areas, rakes are often associated to aspirating machines to harvest the fallen fruit, while the employment of harvesting machines from the ground prevails in flat areas. In this context, the present paper aims to assess technical and economic aspects of harvesting operation, using a harvester from the ground model ‘Jolly 2800’ (GF s.r.l., Italy). Particularly, for technical purposes data about operational working time as well as working productivity were collected according to CIOSTA requirements, in two harvesting sites, whereas, for mechanical harvesting economic evaluation, an estimation model was applied to calculate machinery cost per hour. Moreover, the cost per kg of hazelnut in shell and the average cost per hectare were estimated also. The obtained results show a working productivity of 0.065 ha h-1 op-1 in the first harvesting site, while it was equal to 0.022 ha h -1 op-1 in the second one. Concerning the average cost per hectare, the second harvesting site showed the worst economic performances, with 550.76 € ha-1 against 182.54 € ha-1 obtained in the first one