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Il nucleo rostromediale del tegmento: caratterizzazione elettrofisiologica e ruolo nella neurobiologia delle sostanze d'abuso
Get PDFRecent findings have underlined that the rostromedial tegmental nucleus (RMTg), a structure located just posterior to the ventral tegmental area, is an important site involved in aversion processes (Jhou et al., 2009a;2009b). RMTg contains GABAergic neurons responding to noxious stimuli, that are densely innervated by the lateral habenula (LHb) and provide a major inhibitory projection to reward-encoding dopamine (DA) midbrain neurons (Jhou et al., 2009a, 2009b). Perseverance of drug seeking in spite of negative and unpleasant consequences is one of the key features of drug addiction, possibly mediated by response suppression within neural pathways mediating aversion.
Here, utilizing single unit extracellular recordings in anesthetized rats, we first investigated whether addicting drugs (morphine, the cannabinoid agonist WIN55212-2, cocaine and nicotine) affect RMTg neuron activity. We discovered that 73.2% of putative RMTg GABAergic neurons were excited by aversive stimuli (paw pinch). Moreover, LHb electrical stimulation activated 46.3% of RMTg neurons at short latency (5.5±0.3 ms). When addictive compounds were injected, only cells responding both to LHb activation and paw pinch were selected. Morphine, WIN55212-2 (WIN) and cocaine inhibited RMTg neuron firing rate in vivo. In contrast, nicotine strongly excited RMTg firing rate.
In the follow-up study we investigated whether the previous drugs of abuse affect RMTg-evoked inhibition of DA neurons. To this aim, we studied acute effects of morphine, WIN, cocaine, and nicotine on the inhibitory effects induced on DA cells by RMTg stimulation. The electrical stimulation of the RMTg induced a complete suppression of spontaneous activity in 53.3% of the DA neurons examined, lasting on average 82.5±6.1 ms. The duration of inhibition was inversely correlated (r= -0.71, p<0.0001) to the discharge rate of DA neurons, highlighting that inhibitory inputs from the RMTg strongly control spontaneous activity of DA neurons. Both morphine and WIN depressed this RMTg-induced inhibition of DA neurons in vivo. Conversely, neither cocaine nor nicotine modulated DA neuron responses to RMTg stimulation. Our results suggest that drugs of abuse profoundly influence both RMTg neuron activity and synaptic responses of DA neurons evoked by RMTg activation. These newly characterized neurons, as important inhibitory afferents to midbrain DA cells, might take place in the complex interplay between the neural circuits mediating aversion and reward.
1.Jhou TC et al. (2009a). The rostromedial tegmental nucleus (RMTg), a GABAergic afferent to midbrain dopamine neurons, encodes aversive stimuli and inhibits motor responses. Neuron 61: 786-800.
2.Jhou TC et al. (2009b). The mesopontine rostromedial tegmental nucleus: A structure targeted by the lateral habenula that projects to the ventral tegmental area of Tsai and substantia nigra compacta. J Comp Neurol 513: 566-596
Il recupero dei vuoti: creare nuovi scenari urbani
Get PDFA detailed urban road study cannot prescind from the theme of recovery of its role as heart of urban life. This premise implies a sub version of the common trend to consider the road as a non- place designed for the mere
car transit. This presumed car hegemony is the main cause of degradation in urban areas . The increase in vehicular flow and there lated harmful phenomena ( accidents ,
harmful emissions , noise , landconsumption) cause the disappereance of “ relational spaces ” , therefore a n et decrease i n volume and content of activities of which the road is the scenario. On the contrary, the road has to be a scenari of or a wide range of high social context and calibre events ; these presuppose that the road is also a stage for awide range of voluntary and social activities . These activities pretend highst an dards of t h er m al , acoustic and visual comfort areas wi t h accessibility,
safety and aesthet ic value necessary to persuade people to a more fruitful use of the road. It is fundamental , in the recovery of a road systems trip , to provide a holistic approach , and at avoiding the use of standard solutions , taking each area as a unique and distinctive
La Citè (post) Industrielle. Efficienza energetica urbana
Get PDFMain studies in energy saving in construction have demonstrated the restriction on benefits achievable
with efforts mon buildings and the necessity of a “change of scale” moving from a single residential unit
to the whole urban system. In fact, results attainable with energy saving policies applied on individual buildings tend to level off, requiring necessarily works on an ‘upper’ scale (urban or land scale) in relation to the city size and shape. In a time when energy world situation is asking for a transition toward new alternative sources, interesting research have already confirmed the deep relationship between energy consumptions and urban morphology through the study of some macro-classes of ‘physical’ parameters like: urban density, h/w ratio, settlement’s shape and size, microclimate, ecc. The re-reading of the city hystory from an energy viewpoint, shows the one-to-one relation that exists between spatial configurations, determined by urban design, and the corresponding energy balance. This relationship has
been reasserted also by the foremost international organization (ONU, European Commission, etc.) which
have indicated the urban design as one of the favoured tools to build the future ‘sustainable city’. Although today the actions on this topics are rapidly growing, settlements which can be defined in this way are really few. Difficulties found in this changeover can be ascribed also to the hidden meaning of ‘sustainaiblity’, whose comprehension entails overcoming an urban design ‘by parts’ in favour of an holistic approach which acts on the City seen as an ecosystem interrelated to its environment. This
interdependence is chiefly revealed by input and output processes which govern urban metabolism. Even if the use of new local and renewable sources is a necessary condition to label a city like ‘sustainalbe’, it is insufficient unless accompanied with an appropriate consumption’s containment policy. The designer’s scant attention to the local weather and environmental conditions has been counterbalanced in the
course of time by use of technologies with heavy consequences on global energy consumptions. The rude
awakening from faulty belief on hydrocarbon’s limitless availability forces us to rethink the urban design
process in function of ‘physical’ and environmental parameters which affected city energy behavior. In
fact, the urban energy balance is deeply affected by spatial configurations resulting from typo-morphological initial choices among which the H/W ratio is gaining in importance. The significance that takes the correct urban design on subsequent energy behavior ascribed great responsibility to spatial solutions delineated during the early stage of the project, re-introducing again weather and
environmental data among the basic information used by designers for the correct composition of their works
-Novel indole-1-carbinols and 1,3'- Diindolylalkanes: synthesis and preliminary evaluation of their cytotoxicity in hepatocarcinoma cells: preparation of tris-oxazoles building blocks for the total synthesis of telomestatin
Get PDFThe first chapter of this thesis work describes an efficient and ecofriendly synthetic methodology of the known 1,3’-diindolylalkanes, which were recently brought to the forefront for their anti-carcinogenic properties.
With a similar procedure, novel indole-1-carbinols and 1,3’-diindolylalkanes were synthesized and then subjected to preliminary cytotoxic evaluation on hepatocarcinoma
cells, showing to be great potential anticancer drugs. The second chapter explores possible solutions to the unresolved issue presented by the oxidation of a dihydro precursor of the potent telomerase inhibitor, telomestatin. The assembly of key polyoxazole building blocks for that natural product is discussed
IEEE 1588 synchronization in distributed measurement systems for electric power networks
Get PDFModern electric power systems can be considered as the consequence of the continuous technological evolution, often pushed by economical, political and social requirements. As an example, the main transformations in electric distribution systems arise from the diffusion of
“Distributed Generation” (DG), i.e. small production plants, often supplied through renewable energy sources, whose presence has significant implications on both energy management (since “active networks” are needed to take into account bidirectional energy flows by means of innovative devices) and protection systems (since adaptive protections can be used to automatically reconfigure the network in the case of fault occurrence). In general, in both transmission and distribution networks, monitoring, control and protection tasks are usually performed by Intelligent Electronic Devices (IEDs), which can be, by their nature,
connected to each other by suitable communication links. A famous example of this approach is represented by the series of Standard IEC 61850 (Communication Networks and Systems in Substations). These standards are related to networks and communication systems within the substation, but are used as a reference in all those circumstances in which an electrical system is managed through the use of IEDs communicating with each other (as in the case of active
distribution networks). In this way, control and protection schemes practically become algorithms, whose correct
behavior is determined firstly by the availability of data measured in strategic points of the network. The critical role of the above mentioned applications, which clearly emerges from their implications on safety, as well as from economical considerations, makes it of fundamental importance the evaluation of correctness and trustworthiness of the information on which such actions are based. Many of these applications implemented for control and protection purposes in electric power
networks require the acquisition of information by Wide Area Monitoring System (WAMS) from strategic points of the system and need that the acquired data have an extremely accurate common time reference. Generally, amplitudes and phases of the positive sequence voltages are the
quantities to be estimated in the network nodes. Because of the extension of power networks, suitable measurement devices should be used to ensure proper synchronization between the collected data. Thus, the key components of WAMSs are represented by Phasor Measurement Units
(PMUs) designed to measure synchronized phasors (synchrophasors). Typical synchronization specifications for synchrophasors measurement are in the order of
few microseconds. Such a tight synchronization requirements lead to the need of highly accurate clock settings, such as the ones bases on satellite systems. Currently, the Global Positioning System (GPS) is the only system to provide a time reference with sufficient availability and accuracy for
most distributed monitoring and control applications in power systems. As an alternative, in situations where many devices are located in a geographically limited sub-area (e.g. a substation) of the system and are connected to each other by suitable communication networks (as described by the series of standard IEC 61850), it could be advantageous to distribute the time reference of a high accuracy clock to the devices through suitable network synchronization protocols. Between them, the PTP (Precision Time Protocol)
defined in the Standard IEEE 1588 offers the best accuracy performance. It is worth mentioning that the Standard IEC 61850-9-2 practically indicates Ethernet as a preferred communication solution, thus offering an optimal support to implement 1588 synchronization in electric power plants. In this context, it should be recalled that the IEEE 1588
profile for power system applications (project PC37.238) is being developed under IEEE Power System Relaying Committee (PSRC) and Power System Substation Committee (PSSC). The scope covers all power system applications, including Synchrophasors. The group works in close coordination with TC57 WG10, which plans to adopt the PTP profile in the next revision of IEC 61850. In the first part of this thesis, the state of the art regarding power system evolution, IEEE
Standard on synchrophasor measurements and synchronization system is presented. In particular, the problems related to the evolution of the power system along with some possible advantages due to the implementation of Phasor Measurement Units in Wide Area Monitoring Systems are introduced. After a general description of the architecture of a distributed measurement system based on PMUs, the new synchrophasors standard is analysed, highlighting the differences with
previous versions, the requirements for the measurement of synchrophasors and the definition of synchrophasor under steady-state and dynamic conditions. Moreover, a summary of the possible synchronization solutions is introduced. For each solution, advantages and disadvantages are highlighted. In particular, satellite system and network based protocol are analysed in detail. In the second part of the thesis, a synchronization solution able to exploit the worldwide availability of the GPS and the possibility to disseminate the synchronization signal with high
accuracy by means of the network synchronization protocol IEEE 1588 is proposed. This solution is used for the synchronization of PMUs. The objective of this work is to analyse the possibility to synchronize PMUs via PTP and to study the impact that such a synchronization solution has on the performance of measurement systems under both steady-state and anomalous operating conditions,
as well as its effects on the applications that make use of their data. Two different versions of the PTP are used: the first one uses hardware-assisted time-stamp mechanism whereas the second one uses software-only time-stamp mechanism. Two experimental systems are characterized in detail with an accurate description of all the used hardware and software components, and their synchronization performances under different operative conditions are analysed. Finally, among all the sources which may contribute to the uncertainty introduced by PMUs, the last part of this thesis analyses the impact of the phasor estimation models on the accuracy of these devices, with particular attention to algorithms proposed in literature for the estimation of dynamic phasors and studies their performances under several different conditions
Inkjet printing of organic transistor devices
Get PDFIn the last two decades inkjet printing passed from the field of graphic art and newspaper industry to that of organic and flexible electronics, as a manufacturing tool,
becoming a major topic in scientific research. The appeal of this kind of technology is mainly due to its low cost, non-contact and additive approach, which makes it surely
the most promising technique over the other technologies of Printed Electronics. The focus of this thesis is the optimization of the printing process, employing a piezo-
electric Drop-on-Demand inkjet printer, for the realization of organic transistors on highly flexible plastic substrates, and their development in more complex systems for sensing applications. Indeed, all the devices realized have been investigated by means of electrical measures and spectroscopic techniques, in order to assess their performances and, consequently, to evaluate the reliability of inkjet printing as fabrication technique for such devices. In the first chapter a general introduction to the field of Printed Electronics, with particular focus on inkjet printing technique, is given. The second chapter provides informations concerning the fabrication characterization procedure followed, including a detailed description of the inkjet printing technology used, a report about the main physical and chemical properties of the materials employed, the explanation of the inkjet printing procedure for each material used in this
thesis (as the printing parameters optimization and the approach for the resolution of some technical issues); finally also a brief description of the experimental techniques employed in order to characterize the devices is given. The third chapter is fully dedicated to the results concerning the fabrication and the characterization of all-Organic ElectroChemical Transistors (OECTs), while in
the fourth chapter the results about inkjet printed Organic Field Effect Transistors (OFETs) are discussed. Finally, a brief chapter reports a summary of the main results achieved
Observation and control of PDE with disturbances
Get PDFIn this Thesis, the problem of controlling and Observing some classes of distributed parameter systems is addressed. The particularity of this work is to consider partial differential equations (PDE) under the effect of external unknown disturbances. We consider generalized forms of two popular parabolic and hyperbolic infinite dimensional dynamics, the heat and wave equations. Sliding-mode control is used to achieve the control goals, exploiting the robustness properties of this robust control technique against persistent disturbances and parameter uncertainties
Nuove funzioni dell'affitto di azienda: le regole e l'esperienza
Get PDFThis study, about techniques used in commercial leasing contracts in companies that practice economic development, is influenced by a specific working hypothesis.
It is the study of an entrepreneurial organization that succeeded in the space of a few short years to create an economic initiative capable of promoting the development of a flourishing commercial district in the Cagliari area. This example can give insight into a beneficial use of
linked contracts systems for the creation of big economic operations and the development of productive activities during times where resources are scarce and the economy is contracting. Commercial leasing has always been thought of (and this is also the case with Policentro Domus de Janas corporation) as an excellent contractual technique for developing economic initiative. Even if one only considers how it gives the property owner an income from giving
the right to use all or part of a productive activity, and how the tenant (who generally does not have the capital to risk investing in the beginning) tests the market by starting its own professional activity. With this objective in mind, this paper will develop in the space of three chapters.
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The first chapter will frame commercial leasing in the context of the circulatory phenomena of productive apparatuses. The second will concentrate on analyzing the types of contracts used. In this way, the evolution of commercial leasing contracts will be retraced. Evolution that has affected applicable regulations of the
business branch and the importance of the starting plan for the purposes of presenting negotiations in doctrine and in jurisprudence. The implications that this kind of contract has on a procedural level should not be omitted. With the inclusion of this figure by the legislator on the list of matters to be decided according to article 447 bis c.p.c. on
one side, and subject to the condition of admissibility pronounced by the legislative decree no. 28/2010 on the other. The body of this treatise will consist of analysis in the third chapter of the kind of contracts used by the Policentro Domus de Janas Corporation for the development of its commercial structures. It will also examine the linked contracts system prepared for the economic
operation, the marketing of the areas. This sequence, which would eventually get underway with the signing of a preliminary leasing contract and then evolve into a sale of
the same areas leased, makes it clear that they are specific in nature with regard to the so called organizational and promotional contract and the veritable business leasing contract. In the first of the two negotiations, the parties intend to base the
economic operation and regulate all aspects about the start up and entrance of an entrepreneur in an integrated commercial structure. With the second, the strategy involved in deciding to give to that entrepreneur the right to use the areas through a kind of branch business leasing contract instead of a business lease or a rental of
commercial space.
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In conclusion, the final objective is to understand the peculiarities and limits of application of the model created by the Policentro and the eventual exportability to other kinds of commercial development projects. It is clear that negotiating tools such as commercial leasing allow for
mobilizing capital and getting past restrictions on economic initiatives, restrictions due to the unwillingness of property owners to risk entrepreneurially during economic recession and to scarce creditfrom banking institutions
Trattamento di stabilizzazione-solidificazione mediante leganti idraulici e additivi applicato agli sterili mineralurgici: il caso di Masua
Get PDFEnvironmental issues related to abandoned mining sites are an emergency that finds many examples around the world, with serious adverse effects, both on the people living in those territories, either as impact on the surrounding environment, with serious damage to natural resources. Sardinia is among the Italian regions where mining work had a key role in economic development, and was one of the most important site in Western Europe for high productivity. Nowadays, the legacy left by the mining activity is a valuable historical and cultural heritage that needs to be valorized through the recovery and redevelopment of disused
mining areas. However, it is known that mining activity produce a serious environmental impact, sometimes altering permanently the ecosystem, the morphology of the territory, the hydrological and hydrogeological structures of large areas. Furthermore, among the long period effects, there are problems related to instability of the cultivation sites and of the tailing dams(e.g. landfills, settling ponds).The biggest impact is certainly represented by the dispersion of highly toxic contaminants, such as heavy metals, that are concentrated especially in mine tailings. These constitute an important source of environmental pollution, which can have serious impact on soil and water resources of vast land areas, so as to constitute, in some cases, a risk to human health. In the context mentioned above , fits this research work, that while studying a particular case, constitutes a representative model of specific problems associated with abandoned mining areas. The object is the mining site of Masua, located in South-West of Sardinia (Sulcis-Iglesiente): This area has an elevate natural value and a great tourist potential.
In the past, the site was the most important in Europe for the production of lead and zinc. Inside are two big
settling ponds of tailings, arising from the processes of flotation of minerals mined in the surrounding areas.
The volume of wastes amounts to about 2.5 Mm3 and the occupied surface is 12 hectares. The aim of research is the treatment of the tailings of Masua, by the application of stabilization-solidification techniques, using hydraulic binders and different additives, which, mixed with the waste, allow to minimize the mobility of contaminants. The material is characterized by high concentration of cadmium,
lead and zinc. The leachate reports high content of lead, above the limits of Italian Law concerning inert
wastes. Among the possible reuses of the treated material there is the backfill of mining voids. These are characterized by stability problems, processes of superficial subsidence and collapse of the cultivation halls. Stabilization/solidification techniques using hydraulic binders are an ideal operational strategy to achieve the twin objectives: make the waste less hazardous and reuse of the treated material in operations of mine
backfilling. Binders, like cement, lime and fly ash, give a solid structure and the physical properties required for the
operations of backfilling. Moreover, the solidification process reduces the mobility of metal contaminants through different processes, such as precipitation, adsorption, physical encapsulation, that take place between the pollutants and constituents of the solid matrix. An important aspect is that the reclamation should be economically sustainable. The hydraulic binder, generally, constitutes about 75% of the cost of the entire operation of backfilling. Therefore, it is essential minimize the proportion of this component in the constitution of the mixtures, without, however, reducing physical-mechanical properties, nor the efficiencies of inertization. Low contents of Portland cement, between 3% and 5% by weight, such as those tested in the present study, allow the development of a sufficient cohesive strength and give to the filling mass the self-supporting capacity. However, low
percentages of binders, may not be enough to ensure the appropriate efficiencies of stabilization of the waste.
To solve this problem, It was used a small percentage of certain additives, which, according to their properties, reduce the mobility of contaminants. In particular, have been employed two types of clays (bentonite and a montmorillonite clay). It 'well known that such minerals have high adsorption capacity towards heavy metals. Moreover, in strongly alcaline conditions, such as those that are established during the hydration of Portland cement, they release silicate and alumina compounds, improving the formation of calcium silicate hydrate (CSH) and calcium aluminate hydrate (CAH). These are the main components of the solid matrix, and compounds involved in the fundamental mechanisms of immobilization of heavy metals. Some chemicals additives were used as Bauxsol, potassium dihydrogen phosphate and ferric chloride
hexahydrate. The first is a product resulting from the treatment of residues of the bauxite processing, with high adsorption capacity towards the metal contaminants. The combined use of potassium phosphate and ferric chloride, in small quantities, can convert lead in highly stable forms with low solubility, such as the pyromorphite. The research analyzes the interactions between the treated material and the various components of the tested mixtures. Some key factors that characterize the process of stabilization and solidification have been identified, and some possible solutions to the problems that arise with the use of the adopted techniques have been highlighted . The study focuses solely on the investigation of the chemical characteristics of the inert waste, without, however, analyze the physical and mechanical properties of the same.
Although these aspects are important for the possible reuse of the material, they are subordinate to the legislative constraints, which, as a first , provide for the preservation and protection of environmental from
contaminants that may be released from the treated wastes, when they are deposited in the storage site
L’energia nella definizione del progetto di architettura e paesaggio:le potenzialità delle FER
Get PDFThe topic of this research is the landscape and its transformations due to changes in the use of energy sources and the crisis connected to this. The landscape is formed of the signs and trails left by populations and nature on the area. The signs remain in the long run and influence the growth processes strongly so as to become the “rules” of the physical environment. Energy has a primary role of importance as it has always structured an environment through various uses and technologies. The infrastructures of energy sources are a vital support for the development of populations in economic and social terms. Over the past years the excessive development of cities and the irrational use of the environment has drawn attention to the necessity to consider renewable energy sources (RES) for various reasons: to resolve the climate problem due to the disastrous effects of greenhouse gas emissions in the atmosphere caused by the use of fossil fuels as a main source of supply and the fear of the depletion of those very fossil fuels (non renewable resources). Energy production technologies have been seen as marginal in the great changes in urban landscapes and are considered an accessory in the architecture of a city and landscapes rather than the skeleton of the system. For this reason the research carries out a study of the morphological structure of the landscape, to make it possible to process the structural knowledge for a contemporary project. The project and the transformations have an explorative purpose necessary for understanding and involving, by working on the physical forms, in order to re-establish them in relation to the uses and the meanings they have for the population involved