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Parasite-host relationships in the biological control of insects: strategies of immunoevasion/immunosuppression and interference of temperature on the lethality of entomoparasites.
Full text linkIn this PhD project were considered two aspects of the relationship between bio-insecticide and insect hosts: the first has been the study the mechanisms carried out by EPNs complexes (Steinernema carpocapsae - Xenorhabdus nematophila) to overcome or neutralize the immune system of the insect host. The success of the EPNs results mainly from immunological disabling induced by nematode and its symbionts by immunoevasion/immunosuppression process when released inside the host hemocoel. The functions of structures and molecular components of the surface of both nematodes and bacteria play a key role and we assessed the role of protein pools isolated against Galleria mellonella (Lepidoptera).
The eluted compounds from live nematode possessed a slight cytotoxicity on the haemocytes, whereas those from live bacteria markedly affected the host cells’ viability. Bacterial proteins can inhibit the phagocytic activity, despite they strongly trigger the host prophenoloxidase-phenoloxidase system.
The second part of the project is aimed to acquire useful information on host-parasite relations in the context of climate change and, we reconsidered the physical conditions (such as temperature) in which bioinsecticides are highly effective. We evaluated the effectiveness of different commercial bio-insecticides (Steinernema feltiae, Steinernema carpocapsae, Heterorhabditis bacteriophora and Bacillus thuringiensis) assessing the mortality rate induced in two insect models, Galleria mellonella (Lepidoptera) and Sarcophaga africa (Diptera) after conditioning at various temperatures (10, 20 and 30 °C); moreover, we investigated the effects of temperature on the basal humoral immunity (phenoloxidase and lysozyme activity)
La riforma della disciplina del voto nelle Primavere Arabe: tra cedimento e consolidamento del sistema
Full text linkThe aim of this dissertation is to provide an in-depth analysis of the electoral legislation reforms occurred in Morocco, Egypt and Tunisia during the 2011 uprisings. The main reason behind this choice is to estimates the right to vote regulation impact on the respective constitutional transitions. The author considers the electoral legislation lato sensu to be crucial in understanding the fall or persistence of both ante and post 2011 regimes.
This work can be dived in a theoretical and empirical part, consisting of three chapters each. The first gives an overview of democratization theory from both a constitutional and political scientific perspective. The second provides an analysis of the vote-democracy binomial, only then to deal with electoral system stricto sensu technicalities. The third addresses the issue of the Islamic movements’ nature and more generally the relationship between Islamic traditional institutions, such as the ijma and the Khilafah, and democratic principles. The fourth analyses the Moroccan “prevented” transition, where King Muhammad VI political acumen had been a key factor for preserving the status quo. The fifth covers the Egyptian miscarried transition, culminated with the re-establishment of an authoritarian regime. The sixth offers an overview of the only successful democratization of the Arab spring: Tunisia. The dissertation concludes giving some final considerations
La “buona morte”: analisi del profilo storico e ruolo delle cure palliative nell’accompagnamento di fine vita
No full textThis research focuses on the link between the concept of “good death” and the notion of euthanasia, words connected to each other from an etymological point of view but which differ in meaning and historical evolution. The analysis of the sources relating to “good death” has shown three main research macro-groups: one relating to the concept of “good death” in the ancient world from the classical antiquity to the late imperial age; one relative to the link between “good death” and palliative care and, lastly, the role that consolation plays in the accompaniment of the terminally ill. These reference passages have been chosen on the basis of three useful tools in the setting of Greek-Latin Philology and of ancient Christian Literature: the Thesaurus Linguae Graecae, the Thesaurus Linguae Latinae and the Bibleworks. The analysis of these passages has revealed that the notion of euthanasia in classical Greek and Latin conveyed a concept very different from the modern one. Two fundamental concepts were observed: that of “good death” and that of suicide. In Antiquity the three concepts of euthanasia, “good death” and suicide do not appear any different to today, on the contrary, the notions of euthanasia and “good death” permeate each other and euthanasia, as well as suicide often appear in the sources analyzed as “good death”. The point of view held by the professionals operating in the sector, which has been investigated in the second chapter in the form of an interview, reveals the importance of palliative care in accompanying the suffering person in the final stage of life. The third and final chapter, investigates the role of consolation both in Christian literature (The Bible; Greek and Latin Church Fathers) as well as in the concrete reality of care giving today through the analysis of the results of a survey carried out on caregivers of ten Italian hospices
Adolescent Δ9-tetrahydrocannabinol exposure differently affects histone modifications in the brain of female and male rats
Full text linkDespite the increasing evidence of a possible interaction between adolescent Cannabis abuse and the subsequent development of psychiatric disorders, Cannabis remains the illicit drug most abused by adolescents.
We have previously demonstrated that female rats chronically treated during adolescence with increasing doses of delta-9-tetrahydrocannabinol (THC), the main psychoactive ingredient of cannabis, develop a depressive/psychotic-like phenotype in adulthood. Interestingly, only chronic adolescent exposure to THC, but not adult exposure, led to this complex phenotype, suggesting that adolescence may represent a more vulnerable period for the adverse effect of THC. However, the neurobiology of this vulnerability is not still clear.
Considering the important role assumed by epigenetics in the etiopathogenesis of psychiatric disorders, the main goal of this thesis is to extend our knowledge on the impact of adolescent THC exposure on histone modifications occurring in other brain areas involved in the different aspects of the depressive/psychotic-like phenotype described in our animals. Specifically, we considered the Hippocampus for its involvement in cognition, the Nucleus Accumbens for its role in the reward circuit, and the Amygdala for its relevance in the emotional behaviour. To investigate the existence of age-specificity of THC effects, we performed the same analysis also after adult THC treatment. To investigate sex-dependency of THC response, we also checked THC response in adolescent male animals.
First of all, adolescent (PND 35-45) and adult (PND 75-85) female Sprague-Dawley rats were treated twice a day with increasing intraperitoneal (ip) doses of THC: 2.5 mg/kg, 5 mg/kg, and 10 mg/kg or with its vehicle. Two, 24 and 48 hours after the end of the treatment, the brain areas of interest were collected and. Histone modifications associated with both transcriptional repression (H3K9 di- and tri-methylation, H3K27 trimethylation) and activation (H3K9 and H3K14 acetylation) were evaluated.
Chronic THC exposure affected histone modifications in the brain of female rats in a region- and age-specific manner. Indeed, THC acted on different targets depending on the considered brain areas and, remarkably, the adolescent brain was generally more sensitive to THC exposure compared to the adult one. Specifically, in the Hippocampus of adolescent rats, THC induced a reduction of H3K14ac levels 2 hours after the end of the treatment. This was followed by a significant increase in di- and tri-methylation of H3K9 at 24 hours. Regarding the Nucleus Accumbens, H3K9me3 was significantly increased 2 hours after the end of the treatment. This enhancement was maintained 24 hours later, and it was paralleled by a significant increase in H3K9me2 and H3K14ac levels. On the contrary, at 48h, H3K9me3 levels, as well as H3K9me2 and H3K14ac levels were significantly reduced. In the Amygdala, THC administration induced a significant increase in H3K9me2 levels 2 hours after the end of the treatment. Twenty-four hours later, while this alteration returned to control values, H3K9me3 levels were significantly enhanced.
Adult female rats exposed to chronic THC showed a different pattern of histone alterations. In the Hippocampus and Nucleus Accumbens, H3K14 acetylation levels were significantly increased, respectively, 2 and 24 hours after the end of the treatment. Intriguingly, a more complex picture is present in the adult Amygdala, in which a significant decrease in H3K9me2 and H3K27me3 were induced immediately after the cease of the treatment. Twenty-four hours later H3K9ac was significantly reduced, and at 48 hours, H3K14ac levels were significantly decreased.
As a whole, the investigation performed in female rats suggests that in the adolescent brain THC induced a primary effect represented by changes leading to transcriptional repression, whereas the primary effect induced by adult THC exposure led to transcriptional activation. Interestingly, only in the adolescent brain, the primary effect was followed by a homeostatic response to counterbalance the THC-induced repressive effect, except in the amygdala. The presence of a more complex response in the adolescent brain may be part of the mechanisms that make the adolescent brain vulnerable to THC adverse effects.
The second aim of this thesis was to extend our knowledge on the impact of adolescent THC exposure on histone modifications occurring in different brain areas of male rats. To this aim, adolescent (PND 35-45) male Sprague-Dawley rats were treated with the same protocol previously described for females and we conducted the same analysis in the Prefrontal Cortex, Hippocampus and Nucleus Accumbens.
Chronic THC exposure affected histone modifications in the brain of male rats in a region- specific manner. Surprisingly, in the Prefrontal cortex and Hippocampus, we did not found any histone alterations at any intervals of time, and only in the Nucleus Accumbens we found significant alterations in H3K9me3 levels. Specifically, H3K9me3 was decreased immediately after the end of the treatment and then increased 24h later.
Further studies are needed to clarify the epigenetic landscape in the brain of male rats and how it could account for the development of the psychotic-like phenotype described in these animals.
However, it is possible to conclude that Cannabis abuse during adolescence could impair the brain network functionality acting through a mechanism involving histone modifications that is characterized by sex-specificity
Il pensiero filosofico e politico di Vito D'Ondes Reggio
Full text linkMy thesis focuses on the philosophical and political thought of Baron Vito D’Ondes Reggio (Palermo, 1811 - Florence, 1885). The first chapter is about the baron's life, with special emphasis on his intellectual formation, the sources of his thought, and his specific contribution to the pivotal events in Italian history of the 19th century in which he took part: from the Sicilian Revolution of 1848 to his work as a deputy of the Kingdom of Italy; from his parliamentary resignation after the "capture of Rome" (20 September 1870) to the foundation of the "Work of the Congress" (1874). The second chapter analyses his philosophical thought concerning the relationship between the individual, society, and the State. Finally, the third and last chapter introduces D’Ondes Reggio’s theories concerning the “natural” origin of property and his arguments against the “convenitionalist” position
Molecular and functional characterization of the human RNASET2 oncosuppressor gene.
No full textThe RNASET2 gene maps to human chromosome 6q27, a region that has been consistently found rearranged in many solid and hematological tumors. This gene encodes for the only human secreted acid ribonuclease of the T2 family.
Our research group’s studies have demonstrated a remarkable RNASET2-mediated tumor suppressive activity. Indeed, we recently reported that the oncosuppressive activity of RNASET2 in vivo involves the recruitment toward the tumor mass of cancer-suppressive innate immune cells belonging to the monocyte/macrophage lineage, particularly M1 macrophages, which are known to carry out a cancer antagonizing role.
Given these premises, the aim of my PhD thesis work was to further characterize this gene from a functional point of view.
Firstly, we analyzed the effect of RNASET2 protein in the recruitment and polarization pattern of macrophages in in vitro systems.
Furthermore, since all previous in vivo experiments were performed using nude mice, we started developing a syngeneic mouse model in order to study the role of this gene in an immunocompetent model.
Finally, we recently demonstrated that RNASET2 also behaves as a stress response gene and strongly affects the actin cytoskeleton. To shed more lights on its pleiotropic functions, we also started to investigate the role of this gene in the context of mammary tumorigenesis and morphogenesis
Robust optimization in data envelopment analysis: extended theory and applications.
Full text linkPerformance evaluation of decision-making units (DMUs) via the data envelopment analysis (DEA) is confronted with multi-conflicting objectives, complex alternatives and significant uncertainties. Visualizing the risk of uncertainties in the data used in the evaluation process is crucial to understanding the need for cutting edge solution techniques to organizational decisions. A greater management concern is to have techniques and practical models that can evaluate their operations and make decisions that are not only optimal but also consistent with the changing environment. Motivated by the myriad need to mitigate the risk of uncertainties in performance evaluations, this thesis focuses on finding robust and flexible evaluation strategies to the ranking and classification of DMUs. It studies performance measurement with the DEA tool and addresses the uncertainties in data via the robust optimization technique.
The thesis develops new models in robust data envelopment analysis with applications to management science, which are pursued in four research thrust. In the first thrust, a robust counterpart optimization with nonnegative decision variables is proposed which is then used to formulate new budget of uncertainty-based robust DEA models. The proposed model is shown to save the computational cost for robust optimization solutions to operations research problems involving only positive decision variables. The second research thrust studies the duality relations of models within the worst-case and best-case approach in the input – output orientation framework. A key contribution is the design of a classification scheme that utilizes the conservativeness and the risk preference of the decision maker. In the third thrust, a new robust DEA model based on ellipsoidal uncertainty sets is proposed which is further extended to the additive model and compared with imprecise additive models. The final thrust study the modelling techniques including goal programming, robust optimization and data envelopment to a transportation problem where the concern is on the efficiency of the transport network, uncertainties in the demand and supply of goods and a compromising solution to multiple conflicting objectives of the decision maker.
Several numerical examples and real-world applications are made to explore and demonstrate the applicability of the developed models and their essence to management decisions. Applications such as the robust evaluation of banking efficiency in Europe and in particular Germany and Italy are made. Considering the proposed models and their applications, efficiency analysis explored in this research will correspond to the practical framework of industrial and organizational decision making and will further advance the course of robust management decisions
Role of saliva, gingival crevicular fluid and oral microbiota in gastrointestinal diseases
Full text linkThe aim of this dissertation was the evaluation of the role of saliva, gingival crevicular fluid and oral microbiota in two gastrointestinal conditions: colorectal cancer and Helicobacter pylori gastritis.
In the first study two specific sub-gingival bacteria, Fusobacterium nucleatum and Porphyromonas gingivalis, pathogens typical of periodontal disease, were analysed in order to detect possible correlations with the tumoral changes leading to colorectal cancer development.
In particular, Fusobacterium nucleatum load was found different on the intestinal mucosa of patients with a diagnosis of colorectal cancer and adenoma, compared to the healty control group; on the other hand Phorpyromonas gingivalis, although non directly related with carcinogenesis, might promote the development of the first bacterium.
In the second study the relatioship between the presence of Helicobacter pylori in the stomach and in the oral cavity of patients with and without gastric infection was evaluated. Data suggested that periodontal pockets could represent a favourable enviroment where the microrganism is able to replicate, slipping away from human immune system surveillance, and spread within saliva, reaching the stomach during swallowing and possibly contributing to gastric disease recrudescence.
In the end, a total number of 212 patients were recruited in this experimental work and each study contributed to better understand the relevant role of oral microbiota in gastrointestinal diseases and the importance of a proper oral hygene mantainance in order to reduce the risk of developing dangerous extra-oral illnesses
Diketopiperazines as scaffold for the synthesis of new compounds modulating protein-protein interactions and functions
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Development of nanostructured supported photocatalysts for hydrogen production and inorganic pollutants removal
Full text linkSemiconductor photocatalysis has emerged as one of the most promising approach to exploit a renewable energy source (i.e. sunlight irradiation) for several environmental purposes such as the production of clean energy (e.g. photocatalytic H2 evolution), the removal of organic and inorganic pollutants in natural water, purification of air and antibacterial activity.
In view of these recent trends, the focus of this thesis was directed towards the study of different supported photo(electro)catalytic materials for topical environmental applications:
i) Photocatalytic hydrogen gas evolution from aqueous solutions under UV light irradiation (365 nm) over highly ordered TiO2 nanotubes decorated through a sputtering/dewetting approach with a well-defined stacked co-catalyst (a WO3 layer decorated with Pt NPs);
ii) Photocatalytic hydrogen gas evolution from aqueous solutions under UV light irradiation (365 nm) over highly ordered TiO2 nanotubes decorated through a sputtering/dewetting approach with dewetted-alloyed NiCu nanoparticles;
iii) Photocatalytic reduction/scavenging of inorganic mercury (Hg(II)) from water under solar light irradiation over templated-dewetted Au on TiO2 nanotubes;
iv) Photoelectrocatalytic oxidation/abatement of inorganic arsenic (As(III)) over hematite-based photoanodes under solar light irradiation.
After a general introduction about photocatalytic processes and materials, each chapter of this dissertation contains the outcomes of the above listed studies