On the GKP Vacuum in Gauge/Gravity Correspondences

Within the framework of the AdS5/CFT4 correspondence, the GKP string living on a AdS5 x S5 background finds a counterpart in the anti-ferromagnetic vacuum state for the spin chain, fruitfully employed to investigate the dual N=4 SYM superconformal gauge theory. The thesis mainly deals with the excitations over such a vacuum: dispersion relations and scattering matrices are computed, moreover a set of Asymptotic Bethe Ansatz equations is formulated. Furthermore, the survey of the GKP vacuum within the AdS4/CFT3 duality between a string theory on AdS4 x CP 3 and N=6 Chern-Simons reveals intriguing connections relating the latter to N=4 SYM, in a peculiar high spin limit.

Impact of anthropogenic stressors on the microbial communities in marine holobionts and ecosystems

Free-living or host-associated marine microbiomes play a determinant role in supporting the functioning and biodiversity of marine ecosystems, providing essential ecological services, and promoting the health of the entire biosphere. Currently, the fast and restless increase of World’s human population strongly impacts life on Earth in the forms of ocean pollution, coastal zone destruction, overexploitation of marine resources, and climate change. Thanks to their phylogenetic, metabolic, and functional diversity, marine microbiomes represent the Earth’s biggest reservoir of solutions against the major threats that are now impacting marine ecosystems, possibly providing valuable insights for biotechnological applications to preserve the health of the ocean ecosystems. Microbial-based mitigation strategies heavily rely on the available knowledge on the specific role and composition of holobionts associated microbial communities, thus highlighting the importance of pioneer studies on microbial-mediated adaptive mechanisms in the marine habitats. In this context, we propose different models representing ecologically important, widely distributed, and habitat-forming organisms, to further investigate the ability of marine holobionts to dynamically adapt to natural environmental variations, as well as to anthropogenic stress factors. In this PhD thesis, we were able to supply the characterization of the microbial community associated with the model anthozoan cnidaria Corynactis viridis throughout a seasonal gradient, to provide critical insights into microbiome-host interactions in a biomonitoring perspective. We also dissected in details the microbial-derived mitigation strategies implemented by the benthonic anthozoan Anemonia viridis and the gastropod Patella caerulea as models of adaptation to anthropogenic stressors, in the context of bioremediation of human-impacted habitats and for the monitoring and preservation of coastal marine ecosystems, respectively. Finally, we provided a functional model of adaptation to future ocean acidification conditions by characterizing the microbial community associated with the temperate coral Balanophyllia europaea naturally living at low pH conditions, to implement microbial based actions to mitigate climate change.

Studies on the dual in Mycenaean, in the Homeric poetry and in the Attic Theatre of the 5th century — morphological, dialectal and stylistical variations

The present dissertation focuses on the dual number in Ancient Greek in a diachronical lapse stretching from the Mycenaean age to the Attic Drama and Comedy of the 5th century BC. In the first chapter morphological issues are addressed, chiefly in a comparative perspective. The Indo European evidence on the dual is hence gathered in order to sketch patterns of grammaticalisation and paradigmatisation of specific grams, growing increasingly functional within the Greek domain. In the second chapter syntactical problems are tackled. After a survey of scholarly literature on the Greek dual, we engage in a functional and typological approach, in order to disentangle some biased assessments on the dual, namely its alleged lack of regularity and intermittent agreement. Some recent frameworks in General Linguistics provide useful grounds for casting new light on the subject. Internal Reconstruction, for instance, supports the facultativity of the dual in each and every stage of its development; Typology and the Animacy Hierarcy add precious cross linguistical insight on the behaviour of the dual toward agreement. Glaring differences also arise as to the adoption — or avoidance — of the dual by different authors. Idiolectal varieties prove in fact conditioned by stylistical and register necessity. By means of a comparison among Epics, Tragedy and Comedy it is possible to enhance differences in the evaluation of the dual, which led sometimes to forms of ‘censure’ — thus triggering the onset of competing strategies to express duality. The last two chapters delve into the tantalising variety of the Homeric evidence, first of all in an account of the notorious issue of the Embassy of Iliad IX, and last in a commentary of all significant Homeric duals — mostly represented by archaisms, formulae, and ad hoc coinages.

Advanced studies on two animal models, murine and fish. RadKI21A626T mouse model: new insights into molecular mechanisms of enteric neuro-epithelial pathology. European sea bass: study of the effects of essential oils in different diets on the gastric system.

My PhD research period was focused on the anatomical, physiological and functional study of the gastrointestinal system on two different animal models. In two different contexts, the purpose of these two lines of research was contribute to understand how a specific genetic mutation or the adoption of a particular dietary supplement can affect gastrointestinal function. Functional gastrointestinal disorders are chronic conditions characterized by symptoms for which no organic cause can be found. Although symptoms are generally mild, a small subset of cases shows severe manifestations. This subset of patients may also have recurrent intestinal sub-occlusive episodes, but in absence of mechanical causes. This condition is referred to as chronic intestinal pseudo-obstruction, a rare, intractable chronic disease. Some mutations have been associated with CIPO. A novel causative RAD21 missense mutation was identified in a large consanguineous family, segregating a recessive form of CIPO. The present thesis was aimed to elucidate the mechanisms leading to neuropathy underlying CIPO via a recently developed conditional KI mouse carrying the RAD21 mutation. The experimental studies are based on the characterization and functional analysis of the conditional KI Rad21A626T mouse model. On the other hand aquaculture is increasing the global supply of foods. The species selected and feeds used affects the nutrients available from aquaculture, with a need to improve feed efficiency, both for economic and environmental reasons, but this will require novel innovative approaches. Nutritional strategies focused on the use of botanicals have attracted interest in animal production. Previous research indicates the positive results of using essential oils (EOs) as natural feed additives for several farmed animals. Therefore, the present study was designed to compare the effects of feed EO supplementation in two different forms (natural and composed of active ingredients obtained by synthesis) on the gastric mucosa in European sea bass.