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Metabolomica: un nuovo approccio per lo studio della predittività di farmacoresistenza e di complicanze cardiovascolari in epilessia
Get PDFAbout 30% of epileptic subjects is “drug resistant” (DR) to mono and multiple treatments. The risk of sudden unexpected death (SUDEP) is more than 20 times higher in epileptic patients than that in the general population; SUDEP represents the main cause of death in patients with refractory epilepsy. Several mechanisms probably exist, but most research has focused on seizure related cardiac arrhythmia. No evidence-based intervention to prevent SUDEP exists. Biological basis of DR are still unclear and applying innovative diagnostic techniques for prediction of outcome in the pharmacotherapy of epilepsy is a mission with important social and economical aspects. Genomic
and proteomic are not able to depict the holistic approach that is fundamental for a complete description of phenotiping in human physiology. Metabolomic responses, as integration of genomic and proteomic expressions with the environmental solicitations, can give us the possibility to
investigate about complex interactions in the metabolic networks induced by pathologies or by drugs. Data presented in this paper are 1H-NMR spectroscopy measurements performed by our team in our Clinical Metabolomic Labs, University of Cagliari, on blood samples of epileptic
patients, previously classified by us as drug-responders or not. Using supervised models we are extracting a metabolic characterization, higher in specificity and sensibility with increasing of number of patient, to realize a profile of drug resistance in epilepsy. In this study we present a
PLS_DA model. This is a preliminary model of metabolic alterations in our cohort of DR patients, which could represent a new and non-invasive method for early detection of epileptic patients at risk of sudden death and simultaneously help to clarify the pathophysiological mechanisms of DR and SUDEP
Specificità dei test cardio-polmonari nel nuoto: comparazione tra il nuoto trattenuto e test aspecifici di laboratorio
Get PDFThe purpose of this study is to compare maximal oxygen uptake (VO 2max), maximal heart rate (HRmax), and anaerobic threshold (AT) obtained by a swimming test (SW) and three other testing procedures: cycling (CY), running (RU), and arm cranking (AC). On separate day and randomly assigned, 12 male swimmers (age 19.2 ± 0.8 years, weight 68.9 ± 1.6 kg, and height 177.3 ± 1.7 cm), completed SW, CY, RU, and AC incremental tests to exhaustion. VO2max, HRmax, and AT were measured by a portable gas analyzer. To permit expired gases collection during SW testing, the device was connected to a modified snorkel system. During the SW the athletes showed a higher VO2max compared to the CY and the AC tests. There was no significant difference in VO2max
between the SW and the RU test. The AT occurred at higher workloads during SW in comparison to the other tests. Moreover, the SW test induced a lower HR response with respect to the other tests. These results do not support the use of any unspecific testing procedures to estimate VO2max, HRmax, and AT for swimming. Thus, swimmers should be evaluated in their specific activity since prediction of physiological parameters for swimming from other kinds of efforts can be misleading. The most specific parameter appears to be AT, which showed the most relevant difference between the SW and the other tests
String-brane scattering at high energy
Get PDFThe main purpose of this Thesis is to provide an analysis for tree-level amplitudes involving massive string
states in a D-brane background. String-brane interactions provide an ideal framework to study the dynamics
of the massive states of the string spectrum in a non-trivial background. The infinite tower of massive modes
in the string spectrum is essential for the perturbative finiteness of the string amplitudes. The high-energy limit of string theory is a promising regime to study the relation between string amplitudes and gravitational phenomena. We present here an analysis of tree-level amplitudes for processes in which an NS-NS string state from the leading Regge trajectory scatters from a D-brane into another state from the leading Regge trajectory, in general of a different mass, at high energies and small scattering angles. This is done by using world-sheet OPE methods and effective vertex operators.We find that this class of processes has a universal dependence on the energy of the projectile and that the tree-level amplitudes are in agreement with the eikonal operator form of the string S-matrix
JPEG XR scalable coding for remote image browsing applications
Get PDFThe growing popularity of the Internet has opened the road to multimedia and interactivity, emphasizing the importance of visual communication. In this context, digital images have taken a lead role and have an increasing number of applications. Consider, for example, the spread that
digital cameras and mobile devices such as mobile phones have become in recent years. Thus, it arises the need for a flexible system that can handle images from different sources and are able to adapt to a different view. The importance of this issue lies in the application scenario: today there are datastores with a large number of images saved in JPEG format and systems for rendering digital images are various and with very different characteristics with each other. The ISO/IEC committee has recently issued a new format, called JPEG-XR, created explicitly for the modern digital cameras. The new coding algorithm JPEG-XR, can overcome various limitations of the first JPEG algorithm and provides viable alternatives to the JPEG2000
algorithm. This research has primarily focused on issues concerning the scalability of the new format of digital images.Additional scalability levels are fundamental for image browsing applications, because enable the system to ensure a correct and efficient functioning even when there is a sharp increase in the number of resources and users.Scalability is mostly required when dealing with large image database on the Web in order to reduce the transferred data, especially when it comes to large images. The interactive browsing also requires the ability to access to arbitrary parts of the image. The starting point is the use of a client-server architecture, in which the server stores a database of JPEG XR images and analyzes requests from a client. Client and server communicate via HTTP and use an exchange protocol. In order to minimize the transferred information, the JPEG XR coded file format should make use of the frequency mode order and partitioning of images into optimized tiles. The main goal is transmitting only some subset of the available sub-band coefficients. This is necessary to allow access an interactive access to portion of images, that are downloaded and displayed, minimizing the amount of data transferred and maintaining an acceptable image quality.The proposed architecture has of course prompted a study of errors in transmission on unreliable channel, such as the wireless one, and the definition of possible optimizations/variants of the codec in order to overcome its own limitations. Image data compressed with JPEG XR when transmitted over error-prone channels is severely
distorted. In fact, due to the adaptive coding strategies used by the codec, even a single bit error causes a
mismatch in the alignment of the reading position from the bit-stream, leading to completely different images at the decoder side. An extension to the JPEG XR algorithm is proposed, consisting in an error recovery process enabling the decoder to realign itself to the right bit-stream position and to correctly decode the most part of the image.
Several experiments have been performed using different encoder parameter and different error probabilities while image distortion is measured by PSNR objective metric.
The simplicity of the proposed algorithm adds very little computational overhead and seems very promising as confirmed by objective image quality results in experimental tests
Processi di desolforazione mediante l'utilizzo di adsorbenti e catalizzatori solidi
Get PDFThe sulfur content in fuels is an environmental concern because upon combustion sulfur is converted to SOx, which not only contributes to acid rain, with have a negative effect on human health and in the environment, but also poisons catalytic converters for the treatment of exhaust emissions, which are very expensive due to are based on noble metals Adsorption of organo-sulfur compounds present in liquid fuels on metal–organic framework (MOF) compounds is an efficient alternative to the conventional hydrodesulfurization process. Metal Organic Frameworks (MOFs) are hybrid organic/inorganic crystalline porous materials with unique characteristics with respect to other porous materials (i.e. carbons, silica and zeolites), such as the possibility of tuning the structure during the synthesis, very large surface areas, porosity and a fully accessible internal volume. The void space within these stable network structures can be available to fix guest molecules, being the number of possible MOF/guest combinations practically infinite. A huge variety of applications as “materials for energy” are currently being explored for different types of MOFs. Among these, some MOFs have shown attractive properties as adsorbent materials for organosulfur compounds present in liquid fuels. In this work, it is presented some results on the 4,6-DMDBT adsorption capacity exhibited by the Copper (II) benzene-1,3,5-tricarboxylate MOF (Cu-BTC) obtained through a ball-milling synthesis. Two different methods, called Neat Grinding (NG) and Liquid Assisted Grinding (LAG), were used to prepare NG-MOF and LAG-MOF-compounds, respectively. The chemical–physical features of both samples were analysed by X-ray powder diffraction, thermal analyses and N2 adsorption at 77K. Preliminary results on 4,6-DMDBT liquid-phase adsorption at ambient temperature have shown a higher adsorption capacity, for our ball-milled MOFs in comparison to other previously tested adsorbents. In particular, the LAG-MOF exhibits an adsorbing capacity of the S-compound about two times higher with respect to the analog commercial Basolite-C300 by BASF. It is also presented a study on Ni-Mo and Co-Mo sulphides supported on siliceous materials for the catalytic HDS reaction using thiophene as a model compound is presented here. Pure SBA-15 and silicas, as well as Al-modified SBA-15 and MAS-5, were used as supports, due to the well known structural and textural stability of such mesoporous materials under the HDS reaction conditions. Transition metal oxides were added by wetness impregnation method and alternative impregnation by two solvents techinques, using ammonium molybdate, cobalt nitrate, and nickel nitrate as precursors
Gestures and cooperation: considering non verbal communication in the design of interactive spaces
Get PDFThis dissertation explores the role of gestures in computer supported collaboration. People make extensive use of non-verbal forms of communication when they interact with each other in everyday life: of these, gestures are relatively easy to observe and quantify. However, the role of gestures in human computer interaction so far has been focused mainly on using conventional signs like visible commands, rather than on exploiting all nuances of such natural human skill. We propose a perspective on natural interaction that builds on recent advances in tangible interaction, embodiment and computer supported collaborative work. We consider the social and cognitive aspects of gestures and manipulations to support our claim of a primacy of tangible and multi-touch interfaces, and describe our experiences focused on assessing the suitability of such interface paradigms to traditional application scenarios. We describe our design and prototype of an interactive space for group-work, in which natural interfaces, such as tangible user interfaces and multi-touch screens, are deployed so as to foster and encourage collaboration. We show that these interfaces can lead to an improvement in performances and that such improvements appear related to an increase of the gestures performed by the users. We also describe the progress on the state of the art that have been necessary to implement such tools on commodity hardware and deploy them in a relatively uncontrolled environment. Finally, we discuss our findings and frame them in the broader context of embodied interaction, drawing useful implications for interactions design, with emphasis on how to enhance the activity of people in their workplace, home, school, etc. supported in their individual and collaborative tasks by natural interfaces
New building materials in structural engineering: “Structural concretes made with Coarse and Fine recycled aggregates”
Get PDFWith more than three tons per head, per year, concrete is the most important and widespread material used in construction worldwide. The Italian code allows the use of waste produced by construction and demolition (C&D) operations to produce recycled aggregates. The great interest, both technical-economic and environmental aroused by this subject has in recent years and all over the world led to a noteworthy increase in experimental and theoretical studies on recycled materials resulting from the construction sector and, in particular, on recycled aggregates. The possibility of utilizing recycled aggregate is a very good solution to the problem of C&D waste
and at the same time it reduces quarrying operations and limits the use of natural aggregates. The Italian ministerial decree of 14 January 2008 containing technical regulations for construction works, together with UNI EN 12620 and UNI 8520-2 standards concerning structural materials now allows a limited replacement percentage of only coarse recycled aggregates (sizes above 4 mm), to
produce structural recycled concrete. In this scenario, the research activities described herein were developed with the final purposes of:
Characterizing “real” coarse and fine recycled aggregates derived from construction and demolition waste by only concrete, randomly taken from an authorised class A storage site. This characterization was performed to determine their performance, compliance with the Italian code and the best experimental practice for the production and use in structural concrete. Furthermore the characterization of recycled aggregates by means of their shape, sizes, density, structure, strength, permeability and resistance to freezing and thawing cycles, directly leads to CE+2 certification, which is not present in Sardinia at the moment. Analysing different concrete mixtures made with different replacement percentages of fine and coarse and only coarse recycled aggregates in place of the natural ones to create a product having good properties during production, transport and implementation, with good
compatibility with all devices and machines employed in concrete plants. The intention is to use recycled aggregates produced exclusively by concrete, coming from authorized class A storage sites, immediately after their release from the crusher and to optimize the mix design
of the recycled concrete and the relative packaging procedure. Determining the mechanical properties of recycled concrete made with different replacement percentages of coarse and fine and only coarse recycled aggregates and comparing them with ordinary concrete to measure the gap in performance and evaluating
their use in structural concrete. Reviewing and examining the scientific scenario in the determination of mechanical
properties of the transition zone (ITZ). The results obtained from characterization of fine and coarse recycled aggregates, show a variability in line with what usually occurs in the characterization of natural aggregates, especially for coarse aggregates. The CE marking of recycled aggregates from concrete only, now completely absent in Sardinia, appears to be a feasible goal. However, a complete reorganization of demolition companies with
selective demolition and separation of C&D waste is essential, together with a reorganization of authorized storage sites. Experimental results show a generally good behaviour of fresh and hardened recycled concrete. In
concrete made with only coarse recycled aggregates, for very high replacement percentages of 50% and 80%, the differences with the strength properties of ordinary concrete are minimal, and sometimes irrelevant. In concrete made with fine and coarse recycled aggregates a reduction in
strength was found, but was contained for replacement percentages up to 50%. Fine recycled aggregates present more problems compared to coarse recycled aggregates, especially as regards water absorption and particle size distribution. Their use in practice is possible if the
dosage of water, cement and additives to be included in the mix is studied in advance. The study of the mix in producing concrete, and in particular for recycled concretes, plays a role of fundamental importance.
The excellent results obtained in this experimental work, in terms of workability and strength are probably for the most part to be attributed to the choices made in this stage, mostly as concerns the choice of the additive and the amount of compensating water added to the mixtures.
An important result of the experiments performed concerns the possibility of producing structural concrete using real coarse and fine recycled aggregates coming exclusively from the waste crushed concrete, immediately as it comes out of the crusher, without the need to optimise the grain size
curve. However, an optimal mix design must be arrived at, especially as concerns the W/C ratio and the quality and quantity of additive used
Il patrimonio industriale della Sardegna: il parco geominerario come strumento per lo sviluppo del territorio
Get PDFDuring the 50’s the industrial and mining exploitation process of the Sardinia territory reached its peak, leading this region to the occupation of a strategic position and determining a mono - sectorial flourishing economy. However, once the exploitation c ycle was exhausted, this process left an inheritance difficult to handle. The social, economic and cultural transformations occurred changed the landscape, merging new values to it, and the ruins represent the minor problem: the subsequent economical crisis, the depopulation and the migration of young people are rather the main question. In the past the dismissed industrial sites were considered a source of environmental pollution, however at the end of the XIX century, they were revalued as historical heritage of cultural and touristic interest, which needed to be preserved. The institution of the Geominerary Historic and Environmental Park of Sardinia, acknowledge by Unesco
in 2000, represents the first step towards the preservation of this heritage. However, in order to approach the issues related to local and regional development, it is necessary to discuss also about the loss of identity of this territory, the deterioration of the landscape and the decline its economy, as a consequence of the marginalization of this region in comparison to a global context. The contemporary approach on landscape and territory management refuses the opposition complete
paralysis/ arbitrary manipulation. It is based on the assumption that it is necessary to recognize a nd
valorize the identity of every landscape according to a unique and overall view, which regards both
natural and economical aspects. This thesis, starting from a cognitive approach of the industrial heritage of Sardinia, through the analysis and comparison of high quality case studies, is aimed at defining the theoretical basis for a more complex strategy for the requalification of this heritage. In this sense, the territory is not intended as an homogeneous system, in which the mining operation i s simply replaced by the touristic exploitation. A new development strategy should emerge instead from the local specificities and from the valorization of the architectural and landscape resources of this territory, in order to include them into the production and urban processes of their context
Electronic bidirectional interfaces to the peripheral nervous system for prosthetic applications
Get PDFThe research presented in this thesis concerns the field of bioelectronics, in particular the work has been focused on the development of special electronic devices for neural signal acquisition and Peripheral Nervous System (PNS) stimulation. The final aim of the project in which this work is involved is in fact the realization of a prosthetic hand controlled using neural signals. The commercially available prosthesis are based on Electromyographic (EMG) signals, their use implies unnatural movements for the patient that needs a special training to develop the control capabilities over the mechanical limb. The proposed approach offers a number of advantages compared to the traditional prosthesis, first because the signals used are the same used to control the biologic limb, allowing a more
comfortable solution for the patient that gets closer to feel the robotic hand as a natural extension of
his/her body. Secondly, placing temperature and pressure sensors on the limb surface, it is possible to
trasduce such information in an electrical current that, injected into the PNS, can restore the sensory
feedback in amputees. The final goal of this research is the development of a fully implantable device able to perform a bidirectional communication between the robotic hand and the patient. Due to small area, low noise and
low power constraints, the only possible way to reach this aim is the design of a full custom Integrated Circuit (IC). However a preliminary evaluation of the key design features, such as neural signal amplitudes and frequencies as well as stimulation shape parameters, is necessary in order to define clearly and precisely the design specifications. A low-cost and short implementation time device is then needed for this aim, the Components Off The Shelf (COTS) approach seems to be the best solution for this purpose. A Printed Circuit Board (PCB) with discrete components has been designed, developed and tested, the
information extracted by the test results have been used to guide the IC design. The generation of electrical signals in biological cells, such as neural spikes, is possible thanks to ions that move across the cell membrane. In many applications it is important, not only to record the spikes, but also to measure these small currents in order to understand which electro-chemical processes are involved in the signal generation and to have a direct measurement of the ion channels involved in the reaction. Ion currents, in fact, play a key role in several physiological processes, in neural signal generation, but also in the maintenance of heartbeat and in muscle contraction. For this purpose, a system level implementation of a Read out circuit for ion channel current detection has been developed
Unknown Input Estimation Techniques in Networks and Applications to Open Channel Hydraulic Systems
Get PDFThis thesis is divided in two fundamental parts, namely, the Part I, in which the theoretical background of the UIO, Consensus Algorithms and Decentralized Systems is discussed; after a collection of algorithms is presented. In the Part II, some important applicative problems are
addressed and solved by means of the proposed approaches.
More specifically, as for the Part I, in Chapter 1 the fundamentals regarding the matrix and graph theory are recalled. In the subsequent Chapter 2 the attention is focused on the strong observability approach, and its main features are described. Chapter 3 refers to the presentation
of the Consensus algorithm, while in Chapter 4 an estimation algorithm is recalled, which allows the estimation of the state in an “overlapped” system also in presence of Unknown Inputs (in Chapter 5), which are estimated as well. In the Part II the estimation problems of flow ad infiltration, in open channel hydraulic sys-
tem are solved, using a UIO approach(in Chapters 6). In Chapters 7, considering open channel hydraulic system, the UIO approach is used to solve a problem of fault detection and compensation