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Buffaetal2013
No full textThe database comprises the data of a cross-sectional sample of 1590 adult individuals (836 men and 754 women, 21-49 years old) derived from the National Health and Nutrition Examination Survey, 2003-2004 (NHANES:
http://www.cdc.gov/nchs/**nhanes/nhanes2003-2004/**nhanes03_04.htm
Risk analysis and mitigation of seawater intrusion for the Gaza strip coastal aquifer under climate induced changes
Get PDFCoastal aquifers are in hydraulic contact with the sea; prolonged overpumping of groundwater can lead to inland encroachment and/or vertical up-coning of the interface (transition or mixing zone) between these regimes, causing salt contamination of freshwater aquifers. In the Mediterranean area, seawater intrusion (SWI) has sometimes become a major threat to coastal area freshwater resources, mainly due to lack of appropriate groundwater resources management. Current projections of future potential climatic scenarios further complicate the overview, because the worst considered possibilities provide critical predictions about the decline of the average amount of water available (in terms of both inflows and outflows); furthermore, the projected sea-level rise (SLR) could significantly alter the position and morphology of coastline. A proper analysis and risk assessment of areas subject to SWI, and the evaluation of the coastal basins hydrological response to climate variability, appear to be essential for the design of water management measures that are necessary to mitigate environmental and socio-economic impacts. The key objectives of the study are: 1) development of a methodology of SWI risk analysis in coastal aquifers; 2) application of the methodology to a real case-study (Gaza Strip coastal aquifer, Palestinian Territories) to assess the risk of saltwater ingression and 3) analysis of the effectiveness of mitigation strategies on SWI Risk to support the planning of future spatial and territorial organization. The aquifer system is studied with a simulation code to assess the feasibility of risk mitigation measures under climate induced changes, by the means of simulation/optimization methods, which can provide the quantitative information needed for the management of groundwater resources, with respect to assigned objectives and constraints. Results show that (i) SWI risk assessment can be addressed by means of groundwater simulation models, calibrated against field measures, as a tool to evaluate future contamination in response to projected climate scenarios and exploitation plans, and that (ii) mitigation measures can be developed, according to some predefined criteria, and expected benefits can be quantified.
The research is carried out within the CLIMB project, funded by the 7th Framework Programme of the European Commission
Nanostructures for protection and vehiculation of bioactive molecules
Get PDFAdvances in nanostructured materials and nanotechnologies play a crucial role in engineering innovative systems useful in nanomedicine applications. For example, the most promising drug delivery systems belong to the colloidal domain and, particularly, to the soft matter. Indeed, a growing effort in the discovery of innovative therapies has led to an increasing demand for drug delivery vehicles whose capability should go far beyond the task for which they were originally designed for, that is the simple transport and indiscriminate release of the drug. In principle, every newly formulated nanocarrier should be able to selectively release the drug. Mainly, overcoming the biological barriers that prevent the drug to reach the pathologic site represents the strictest requirement. Thus, a major objective of formulation chemistry is to improve bioavailability, stability, and, last but not least, convenience to the patient. Lipids, along with proteins and nucleic acids, are essential biomolecules for the structure and function of living matter. Most lipids are fats and waxes, but many others have unique structural features due to their amphiphilic character. The choice of polar lipid based systems to build nanostructured architectures to entrap, protect, and release therapeutic agents with hydrophilic, lipophilic, or amphiphilic nature, appears a good strategy since polar lipids such as phospholipids or monoglycerides are generally friendly toward biological membranes and favor bioadhesion.
The physico-chemical characterization of structure and stability of three different lipid based formulations intended for drug delivery is the central issue in this thesis. The main contents here discussed are outlined as follows. General features of amphiphiles and their behavior in aqueous solutions will be presented in Chapter 1. Chapter 2 is a theoretical review that describes the main techniques used throughout this study. Chapter 3 reports on two different formulations where monoolein, a natural monoglyceride, and lauroylcholine chloride are the main components. Finally, Chapter 4 presents a third formulation: a water-in-oil emulsion stabilized by a liquid crystalline lamellar phase consisting of a technical grade soy lecithin (LCT), triolein (GTO) and water (W). The first system investigated is a novel cationic liposome nanocarrier, having interesting performance in topical drug delivery. Both monoolein and lauroylcholine chloride, due to their high biocompatibility, can be regarded as strong penetration enhancers. They are combined to rapidly formulate (15 min) a cationic liposome nanostructure endowed of excellent stability ( > 6 months) and skin penetration ability, along with low short-term cytotoxicity, as evaluated via the MTT test. Cytotoxicity tests and lipid droplet analysis give a strong indication that monoolein and lauroylcholine synergistically endanger long-term cells viability. The physicochemical features, investigated through SAXS, DLS, and cryo-TEM techniques, reveal that the nanostructure is retained after loading with diclofenac in its acid (hydrophobic) form. The drug release performances are studied using intact newborn pig skin. Analysis of the different skin strata proves that the drug mainly accumulates into the viable epidermis with almost no deposition into the derma. Indeed, the flux of the drug across the skin is exceptionally low, with only 1% release after 24 h. These results validate the use of this novel formulation for topical drug release when the delivery to the systemic circulation should be avoided.
The second formulation is strictly related to the first one, since it concerns an innovative vesicle-based gel essentially obtained by concentrating the system previously described. A number of vesicular formulations were prepared, in the range of 4–14 wt% of the dispersed phase, to investigate the system evolution from the dilute unilamellar vesicle dispersion (the first formulation) to a vesicle lipid gel. Morphology, thermal stability up to 55 °C, and viscoelastic properties, along with the effect of acid diclofenac inclusion within the formulation, were evaluated by cryo-TEM, SAXS, and rheological measurements. Moreover, the nanostructure of the vesicle dispersion obtained upon gel dilution in water was assessed by cryo-TEM and SAXS, while DLS was used to monitor the formulation stability (size and -potential). All the collected results lead to the conclusion that this new vesicle-based gel displays all the requirements needed for application in the pharmaceutical and cosmetic fields. The LCT/GTO/W partial phase diagram was investigated by visual inspection and optical microscopy in polarized light, SAXS, and 2H NMR spectroscopy to define the type of phases and characterize their structural parameters. Ternary LCT/GTO/W mixtures prepared with 85/15 and 90/10 constant mass ratio and increasing amounts of water were investigated. Particularly, it was found that the dominant hexagonal liquid crystalline phase identified at low water content evolves toward an emulsion region stabilized by a lamellar liquid crystalline phase for water content greater than 15% wt/wt. The emulsion having composition LCT/GTO/W = 58/11/31 was chosen to encapsulate the bioactive molecules lysozyme (LSZ) and caffeine. The thermal stability was assessed by means of SAXS in the temperature range 4-55 °C. The drug release performances were studied using Franz cell apparatus and a synthetic membrane made by cellulose acetate. After 24 h, the percentage of protein detected in the release media was equal to 10% of the nominal content of the formulation, while in the case of caffeine 80% of the initial content was released after 15 hours. In both cases, due to the use of a liquid crystalline phase as dispersing medium, burst release of the biomolecules from the formulations is prevented. Evaluation of the residual activity of the released protein was also carried out using the Micrococcus lysodeikticus assay. Approximately 30% of the released LSZ retains its enzymatic activity. The full biocompatibility of the formulation ingredients along with the absence of burst release for the investigated cases allow suggesting this formulation as a promising topical drug carrier for sustained release. Indeed, this formulation presents other advantages over conventional creams and ointments such as higher storage stability, good production feasibility, higher kinetic stability and, in particular, the absence of organic solvents in the preparation
Sintesi e caratterizzazione di nanocompositi aerogel altamente porosi per applicazioni catalitiche
Get PDFThis thesis has focused on the synthesis, characterization and catalytic applications of nanocomposite aerogels, made out of an active nanophase dispersed in a highly porous
amorphous silica matrix. These nanocomposites have unique properties which mainly depend on the composition, size and distribution of the nanoparticles and on the morphology and porosity of the matrix. Highly porous MFe2O4-SiO2 (M = Co, Ni, Mn, Zn), NiCo2O4-SiO2, Fe/Mo-SiO2, CuO-SiO2, Cu2O-SiO2 e
Cu-SiO2 nanocomposite aerogels, with variable amounts of dispersed phase, were prepared by a sol-gel procedure followed by supercritical drying and thermal treatments. This method is based on the co-hydrolysis and co-gelation of the precursors of the matrix and the dispersed phase
through the pre-hydrolysis of the TEOS (tetraethoxysilane) under acid conditions followed by gelation under basic conditions, using urea as gelling agent. The detailed characterization of nanocomposite aerogels was carried out using a multitechnique approach involving conventional techniques, such as X-ray diffraction (XRD), nitrogen
physisorption at 77 K and transmission electron microscopy (TEM), associated with more advanced techniques such as X-ray absorption spectroscopy (XAS), Mössbauer spectroscopy and SQUID magnetometry. These nanocomposites, thanks to their high porosity, low density and high area surface, were
tested as catalysts in important industrial processes such as the synthesis of Carbon Nanotubes via Catalytic Chemical Vapour Deposition (CCVD) and the Water Gas Shift Reaction (WGSR), which plays an important role in the technology of fuel cells (FC), showing interesting catalytic activities.
The tests for multiwall carbon nanotubes (MWCNT) production and for WGSR were performed in collaboration with the Applied and Environmental Chemistry Department of Szeged University (Hungary), the Chemistry Department of Rome University “La Sapienza” and the Chemical and Earth Science Department of Cagliari University
Modello di calcolo multifisico per la progettazione dei requisiti acustici, energetici ed illuminazione naturale degli edifici
Get PDFMulti physical calculation model for the design of acoustic requirements, energy and natural lighting of buildings interfaced with three-dimensional CAD architectural. The model calculates with single procedure the physical performance of buildings by taking the geometric information from the three-dimensional model generated in CAD
La Tavola Ritonda tra intrattenimento ed enciclopedismo
Get PDFThis thesis analyses the role of the Tavola Ritonda, a Tuscan rewriting (beginning of the 14th century) of the Prose Tristan, a 13th century French compilation, in the outline of the Italian medieval literature.
The Prose Tristan achieved for the first time the merging of the Arthurian world with the legend of Tristan and Iseult and it quickly became a very successful work. This is the reason why, by the end of the 13th century, the Prose Tristan crossed the boundaries of France and reached Italy, where it was translated by anonimous compilers and brought up to date to adapt the legend to a different literary aesthetics.
The first chapter points out the various approaches of the Italian interpreters to the Tristanian matter through the analysis of the prologues and of the epilogues of the Italian translations: the Tristano Riccardiano, even if mutilated, is the first attempt of a bourgeois interpretation of the legend; the Tristano Panciatichiano makes an anthological choice by juxtaposing several Arthurian romances, while the Tristano Veneto is the most faithful and complete Italian translation.
Among the Italian Tristan romances, the Tavola Ritonda is the most original rewriting, capable of combining the bent to the entertainment typical of this cultural production too summarily labelled as Trivialliteratur and an evident disposition to encyclopaedism. Chivalry is presented at the same time as a game, a literary amusement, and as a duty, a concrete possibility to promote the civil commitment. In the Tavola Ritonda the chivalric past is recovered not only because it feeds a mythology that influences the collective immagination as much for aristocracy as bourgeois, but also because it represents the cultural scenery on which to pin new literary materials. The Tavola Ritonda is actually subjected to a project of strong moralization and rationalization of the Tristanian legend: the merveilleux is marginalized and reinterpreted in scientific terms; a new dialogue is established with the contemporaneity, clearly recognizable over the patterns of reasoning, the large number of proverbs, a different use of toponymy influenced by the Italian geography. The countless hints to the medieval lyric poetry and to the philosophical, scientific and religious production are as many ways to transform the myth of Tristan and Iseult in a sort of encyclopaedia, capable of creating an original dialectic between different literary and light non-literary genres
Applicazione di tecniche diagnostiche non distruttive per la caratterizzazione dei materiali costruttivi di natura carbonatica
Get PDFThe geological district of Cagliari and the Maltese archipelago are composed mainly of limestones, the most important of which are the Oligo-Miocenic Limestone of Cagliari and the Globigerina Limestone, which are widely used in construction.
The Oligo-Miocenic limestone of Cagliari is commonly known to exist as three main types: “Pietra Forte”, “Tramezzario” and “Pietra Cantone”.
The Globigerina Limestone is commonly known to exist as two main types: "Franka" and "Soll", which terms derive from the terminology used by quarry and construction workers.
Currently many buildings of Cagliari and Maltese buildings are still being built using limestone; in addition all the important historical buildings in Cagliari and in Malta are also constructed in this material, among these the most important Maltese monuments belong to UNESCO World Heritage.
The Oligo-Miocenic limestone of Cagliari and the Globigerina Limestone (as the type "Soll" of Globigerina Limestone), manifest problems of durability and weathering resistance, especially due to the presence of soluble salts. Thus the ability to distinguish the types of limestone before extraction from the quarry and its use in construction and restoration is of prime importance.
As regards the Globigerina Limestone, for hundreds of years in Malta the selection of this limestone has been entrusted to quarry and construction workers, who with their experience and using primarily visual and tactile criteria, can usually identify a suitable material for construction and distinguish between types, something which is impossible for a person not experienced in this field. The current work provides an example of how it is possible to distinguish between the different types of Oligo-Miocenic limestone of Cagliari and Globigerina Limestone, at least those at the "extremes" of the range of types, and their water absorption characteristics (fundamental when durability is being considered), using non-destructive analytical methods - ultrasonic and thermographic methods - in a novel way for this specific material.
These methods should offer an additional option to the macroscopic identification of these materials and conventional laboratory tests.
It is also useful to distinguish the type and quality of the limestone used in an existing construction in order to perform a diagnosis of the state of conservation of the work and to be able to perform, more consciously, an eventual intervention of restoration. In this perspective, in this work, taking into account the interesting results obtained in the experiments carried out in laboratory, are also presented the results of in situ experiments, carried out on monumental and modern structures. The on-site analysis were performed using the same techniques used for laboratory measurements -ultrasonic and infrared measures-, these non-destructive techniques are used to perform speditive and reliable analysis and allow to operate without causing damage to the structures
Studio della contaminazione da IPA del riccio di mare Paracentrotus Lividus in Sardegna
Get PDFThe goal of this work of thesis is to building a pratical method to be used for testing and monitoring the chemical pollution of restricted marine areas. The sea urchin
Paracentrotus Lividus (Lamarck - 1816) was the biomarker adopted for this study. This echinoderm, usually present in the shallow coastal water of the Mediterranean sea, is
basically herbivorous but can feed on many other organisms like plankton and all marine food falling down in the bentonic area of the coastal sea. Unlike mussels wich filter water it feeds mainly on micro and macroalgae and is not influenced by the sea tide, so it is a reliable instrument to performing analytical checks about local pollutions of coastal areas. To extract from the matrix and analyze the sea urchin’s roes, or better is to say male and
female “gonads”, was built a modified “QuEChERS” method (Quick, Easy, Cheap, Rugged and Safe), based on dSPE (dispersive Solid Phase Extraction) instead of SPE (Solid
Phase Extraction) as usually performed earlier. The extraction was performed by using only two centrifuge tubes with a little quantity of solvent, avoiding previous separation of fat acids from matrix and isolation phases of the pollutant compounds by gel packed columns and with consumption of a big quantity of solvents. Were investigated to this purpose 17 polycyclic haromatic hydrocarbons in gonads of Paracentrotus Lividus sea
urchin. Was performed a validation of the method determining instrument limit of detection (LOD) and quantification (LOQ), recovery, precision and linearity. Were determinated good parameters with LOD under 1,5 μg/kg and LOQ under 5 μg/kg for all PAH, in agreement
with quality criteria of Commission Regulation (EC) n° 333/2007. The recovery ranges were from 72 to 119 %, with RSD ranging from 3 to 17 % in the worst case. Precision and
linearity were in accordance with EC SANCO/10684/2009 values. Lipophilic Polycyclic aromatic Carbons were investigated from two Sardinian areas: “Capo Pecora” in west
Sardinian coast with low agricultural, industrial and antropic density area, and “Capitana”, with high antropic density.The sea urchins were from rocky sea bottom and from meadows of “Posidonia Oceanica”, a marine sea grass most frequently present in the Mediterranean sea. Many of these pollutants were determined in the gonads of the two areas showing a general ubiquity beginning from the PAH’s with a low number of rings to more heavy pollutants. It’s not hazardous affirm that this work of thesis has been an important step to performing analysis of the PAH’s in sea urchin’s gonads and to use this marine animals as
reliable biomarkers on detecting and monitoring the contamination of restricted areas of coastal regions
Misura della connettività e della dispersione dell’aragosta rossa Palinurus elephas (Fabricius, 1787) in Sardegna con l’uso di marcatori genetici STRs e mitocondriali
Get PDFMeasures of connectivity and dispersion of the spiny lobster Palinurus elephas (Fabricius, 1787) in Sardinia through the use of STRs and mitochondrial genetic markers
The spiny lobster Palinurus elephas is an important alieutic resource for all the Mediterranean Sea and especially Sardinia. For this reason, recently, in order to protect the intensively exploited stocks of the species, several no-take areas have been created in Sardinia seas. Apart from the first area (Su Pallosu), established in 1998, 14 new no-take areas have been created in 2009, after the encouraging results of the first experimentation.
On the basis of this new important project, for the first time a genetic survey was established, through the development of this thesis, in order to achieve several important objectives. In fact, the present work permitted to: i) evaluate the genetic effects of the first pilot project established in Su Pallosu in 1998, comparing the molecular data of individuals sampled at the time of the institution and after twelve years; ii) provide the first genetic data and characterize the populations living in the new no-take areas, which will serve as a future baseline for comparison in assessing the effectiveness of new project; iii) estimate the extent of the gene flow and thus the connectivity and genetic structuring among populations of Palinurus elephas in Sardinia; iv) assess the health status of the stock, through the measurement of genetic variability and any demographic changes over time; v) verify the efficiency and the differences of two genetic markers here implemented.
The study was accomplished through the use two different molecular markers: 10 different microsatellite loci, of nuclear origin, and a portion of the mitochondrial control region. The two types of markers have substantial differences in terms of measuring the spatial and temporal variability, thus can be considered complementary in the study.
In order to achieve all the objectives, 305 individuals of spiny lobsters were sampled, representing 7 of the 15 no-take areas, and genetically characterised for all microsatellite loci and mitochondrial control region.
Results evidenced a positive increment in genetic variability in the first experimental area Su Pallosu from 1998. This results enforces the success of the repopulation action. Moreover, mitochondrial marker did not reveal any significant structure among sampling sites, whereas the individuals seem to belong to the same unique population. From a demographic point of view, Su Pallosu sample seems to be stable, mainly because of the release in the area of tagged spiny lobster during the restocking project, while all other samples are most probably expanding at the moment. Once again, all efforts towards the establishment of an active repopulation seems to be positive.
Microsatellite loci, on the other side, seem to reveal a fable population structure, also because of the higher resolution degree of the marker, nevertheless this structure is not to be considered as consequence of a reduced gene flow. This weak structure could be the result of two important opposite forces driving the gene flow: a very dispersive larval phase versus a more sedentary adult lifestyle.
In conclusion, the results here shown demonstrate the efficacy of a more aware and conscious policy towards such an important ecological and economic resource. All efforts to repopulate and make recover the Sardinian spiny lobsters population seem to be effective and should be maintained and improved whenever and wherever possible. The results obtained today, originating in 1998, give strong support for locally defined management and conservation plans strategies that have been demonstrated to be effective
A theory of agreements and protection
Get PDFIn this thesis we propose a theory of contracts. Contracts are modelled as interacting processes with an explicit association of obligations and objectives. Obligations are
specified using event structures. In this model we formalise two fundamental notions of contracts, namely agreement and protection. These notions arise naturally by interpreting contracts as multi-player concurrent
games. A participant agrees on a contract if she has a strategy to reach her objectives (or to make another participant sanctionable for a violation), whatever the moves of her counterparts. A participant is protected by a contract when she has a strategy to defend herself in all possible contexts, even in those where she has not reached
an agreement. When obligations are represented using classical event structures, we show that agreement and protection mutually exclude each other for a wide class of contracts. To reconcile agreement with protection we propose a novel formalism for modelling contractual obligations: event structures with circular causality.
We study this model from a foundational perspective, and we relate it with classical event structures. Using this model, we show how to construct contracts which guarantee both agreement and protection. We relate our contract model with Propositional Contract Logic, by establishing
a correspondence between provability in the logic and the notions of agreement and strategies.
This is a first step towards reducing the gap between two main paradigms for modelling contracts, that is the one which interprets them as interactive systems, and the one based on logic