702 research outputs found
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The allocation of risk in the public-private partnership (PPP) between public contracts and concessions.
Full text linkNell’elaborato sono delineati i passaggi che hanno portato all’emersione del PPP a livello europeo in veste di strumento politico di gestione della complessità (v. TEN) e, di riflesso, nell’ordinamento nazionale (seppur con qualche perplessità).
L’intento è quello di far chiarezza sull’annosa distinzione fra appalti e concessioni (tradizionalmente considerati agli antipodi del public procurement), distinzione che si fonda sulla diversa allocazione del rischio.
Così come non esiste una definizione precisa di cosa sia il rischio, non esiste neppure una metodologia unica e risolutiva per farvi fronte: la golden rule vuole solamente che il rischio sia posto in capo alla parte che meglio sappia gestirlo in virtù della propria competenza ed esperienza, nonché della propria attitudine verso il rischio.
Il public procurement in generale ed il PPP in particolare dovrebbero perseguire le cd. “3E” (economicità, efficienza, efficacia) avendo sempre ben presente l’interesse collettivo.
In this study are highlighted the steps which have lead to the emersion of the PPPs as a political tool to manage complexity at European level and, as a result, into national law (even though some perplexities remain).
The intent is to shed light on the distinction between public contracts and concessions (traditionally considered as the antipodes of the public procurement), a distinction that is based on the different risk allocation.
Likewise there is no precise definition of what constitutes risk, there is not a unique and resolving methodology for dealing with it: the golden rule just wishes that the risk is placed in the hands of the parties who know how to handle it better by virtue of their expertise and experience, as well as of their own attitude toward the risk.
The public procurement, in general, and the PPPs, in particular, should pursue the “3Es” (economy, efficiency, effectiveness) always bearing in mind the public interest.
Since the risks depend on the performances included in the contract and on the interests, even superindividual, to be pursued, they both do enrich the content of operating risk.
To reach solutions cd. “triple win”, that is to say shared by public administration, businesses and communities, it is necessary to adopt a method of public procurement which does ensure the highest social welfare.
I rischi dipendono infatti dalle prestazioni incluse nel contratto e dagli interessi, anche superindividuali, tutelati, talché entrambi arricchiscono di contenuto il rischio operativo.
Per addivenire a soluzioni cd. “triple win”, vale a dire condivise da p.a., imprese e collettività, è necessario adottare una metodologia di approvvigionamento pubblico che garantisca il maggior benessere sociale
Edge manipulation techniques for complex networks with applications to communicability and triadic closure.
Full text linkComplex networks are ubiquitous in our everyday life and can be used to model a wide variety of phenomena. For this reason, they have captured the interest of researchers from a wide variety of fields. In this work, we describe how to tackle two problems that have their focus on the edges of networks.
Our first goal is to develop mathematically inferred, efficient methods based on some newly introduced edge centrality measures for the manipulation of links in a network. We want to make a small number of changes to the edges in order to tune its overall ability to exchange information according to certain goals. Specifically, we consider the problem of adding a few links in order to increase as much as possible this ability and that of selecting a given number of connections to be removed from the graph in order to penalize it as little as possible. Techniques to tackle these problems are developed for both undirected and directed networks. Concerning the directed case, we further discuss how to approximate certain quantities that are used to measure the importance of edges.
Secondly, we consider the problem of understanding the mechanism underlying triadic closure in networks and we describe how communicability distance functions play a role in this process.
Extensive numerical tests are presented to validate our approaches
Evaluation by optical and soil sensors of forest seedlings grown in controlled conditions under low-energy lighting (LED)
Full text linkIntroduction
LED lights have a lower environmental impact than traditional lights due to a series of factors such as their wavelength specificity and narrow bandwidth, high energy-conversion efficiency, small volume, longer life, low thermal energy output. Concerning plant growth, the uses of LED lights provide specific wavelength as well as the possibility to adjust light intensity/quality. The increasingly need to reduce energy consumption worldwide, raised the necessity to improve LED lights use. The present study aims to 1) examine the effect of different LED light spectra on forest seedlings growth of different species, in order to define a species-specific cultivation protocols under optimal plant growth spectrum to enhance plant growth performance 2) compare direct measurements with indirect method by optical sensors system for automatic plant phenotyping 3) develop soil sensors system for automatic measurements of optimal soil water content. The plant species analysed, widely used in protective and productive planted forests, were: Scots pine Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L.), Beech (Fagus sylvatica L.), Holm oak (Quercus ilex L.), Pomegranate (Punica granatum L.), Strawberry-tree (Arbutus unedo L.), Firetree (Morella faya (Ait.) Wilbur), Sanguinho (Frangula azorica Tutin) and Azores laurel cherry Prunus azorica (Hort. ex Mouillef.).
Materials and methods
Seeds of almost all investigated species were pre-treated to removal dormancy before sowing in mini-plug container. Trays were placed in growth chambers (12-14-16 h photoperiod, 110 ±10 μmol m-2 s-1 PAR, temperature 20-30°C, humidity 55-80%). Seedlings were left to grow for 4-8 weeks under G2, AP67, AP67-3L, NS1, AP67tube LED light (Valoya) and Fluorescent light (FL). The LED lamps used in this study emitted a continuous spectrum thanks to a mixture of blue, green, red and far-red LEDs. Direct measurements of plant height, root length, shoot and root biomass were carried. In order to estimate total root length, roots were scanned and analyzed by WinRHIZO Pro V. 2007d. Non-destructive analysis was carried by measuring Greenness (percentage of shoot cover projected on tray ground) and Plant height by optical sensors. Greenness data were obtained by a series of images acquired by specific developed Optical sensors system (ACREO) and analysed by uEyeDualcam software. After that HeightMap software recalculate greenness using uEyeDualCam settings output and create a plant height map (cm) of the tray conferring a value to the pixel of the selected images.
Plant height data, manually taken during the growth period, were used to find a relationship with plant biomass and with data from images analysed by uEyeDualcam HeightMap software (ACREO). Electronic soil sensors tested in the trays with and without seedlings helding watering for two weeks in order to evaluate the soil water content measurements efficiency of the soil. Soil water content measurement obtained by the software “Zephyr logger” (Acreo) was compared with the SWC calculated by gravimetric measurements.
Results and discussion
The best results recorded for all studied species were under AP67, AP67-3L and G2 LED light type for all morphological parameters analysed. The lowest values among all LED light type were obtained under NS1 LED type for almost all morphological parameters. Results showed a linear increment of seedling height in time for six species (Pinus sylvestris, Picea abies, Quercus ilex, Fagus sylvatica and Punica granatum) and for all different light types. P. sylvestris, P. abies and A. unedo showed interesting results in root length mainly under G2 LED type. A. unedo showed slightly higher biomass values for seedlings growth under G2 LED light type, in particular for root and leaves biomass. The lowest values among all LED light type were obtained under NS1 LED type for almost all studied morphological parameters. The low seeds germination of Morella faya species was detected under all different LED light types. In particular, Morella faya seeds did not show any germination under AP67-3L LED light type. Analysis of the total dry mass increment (g; shoot + root) showed the highest values for seedlings growth under AP67 light type (bar) among all LED light types and control light. The lowest values of total dry mass increment were measured for seedlings growth under AP67 tube. A high heterogeneity in seed germination and plant growth was observed. Concerning the optical analysis results, relation between greenness and seedling biomass showed good correlation for all species until the tray was fully covered. Instead, the relation between seedling height and biomass showed good results with the two broad-leaved species but no relation was found for the two needle-leaved species. Indeed, the constant height of P. abies (L.) and P. sylvestris (L.) because internodes elongation did not occur during the consecutive emissions of new leaves, did not relate to the continuous increment of seedling biomass. This is probably due to the specie-specific characteristic. Thus, the best regression model to explain the relationship between direct biomass data and indirect measurements was based on parameters such as plant height, for broad-leaved species, and plant greenness for needle-leaved species. The main result of our study is that the relevance of relations between non-destructive parameters and forest seedlings growth is species specific.
Conclusion
- Plant growth performance with LED light is specie-specific.
- LED lights represent an efficient and valid alternative to the fluorescent light.
- The best performance for all studied species are observed with AP67, AP67-3L and G2 LED light type whereas NS1 LED type seems to not be suitable for this use.
- G2 gave some good results but due to its higher percentage of far-red/red, it can cause operators’ eyes fatigue and could interfere with optical measurements such as greenness.
- Finally, AP67 and AP67-3L LED type could represent the best option for a standard cultivation protocol.
Data collected confirm that optical system (sensors and software) could represent a robust method to measure plant phenotype as alternative to the traditionally used destructive methods.
Protocol of seed germination developed during the present study and applied to Morella faya seeds, showed good results for the ex-situ plant species conservation objective.
Electronic soil sensors represent a good system to monitor the water content in the soil and when they are used in combination with LED light, and optical sensors the result is a complex system characterized by high level of cost-effectiveness coupled with a good possibility to save energy consumption and reduce pollutio
Human induced pluripotent stem cells as a source of insulin-producing cells for cell therapy of diabetes
Full text linkBACKGROUND
New sources of insulin-secreting cells are strongly required for the cure of diabetes.
Recent successes in differentiating embryonic stem cells, in combination with the discovery that it is possible to derive human induced pluripotent stem cells (iPSC) from somatic cells, have raised the possibility that patient-specific β cells might be derived from patients through cell reprogramming and differentiation.
AIMS
In this study, we aimed to obtain insulin-producing cells from human iPSC and test their ability to secrete insulin in vivo.
METHODS:
Human iPSC, derived from both fetal and adult fibroblasts, were differentiated in vitro into pancreas-committed cells and their ability to secrete insulin was measured. iPSCderived cells at two different stages of differentiation (posterior foregut and endocrine cells) were transplanted into immunodeficient mice to test their ability to engraft, differentiate and secrete insulin.
RESULTS:
IPSC were shown to differentiate into insulin-producing cells in vitro, following the stages of pancreatic organogenesis. At the end of the differentiation, the production of INSULIN mRNA was highly increased and up to 14% of the cell population became insulin-positive. Terminally differentiated cells also produced C-peptide in vitro in both basal and stimulated conditions. In vivo, mice transplanted with pancreatic cells secreted human C-peptide in response to glucose stimulus, but transplanted cells were observed to lose insulin secretion capacity during the time. At histological evaluation, the grafts were composed of a mixed population of cells containing mature pancreatic cells, but also pluripotent cells and rare neuronal cells.
CONCLUSION:
These data overall suggest that human iPSC have the potential to generate insulinproducing cells and that these differentiated cells can engraft and secrete insulin in vivo
Integrità nella ricerca: il dibattito etico sulla pubblicazione dei dati.
Full text linkQuesto lavoro è il risultato di una ricerca, svolta seguendo il Progetto di Dottorato da me presentato, riguardo il tema della pubblicazione dei risultati delle sperimentazioni cliniche.
Essa si è svolta presso le strutture di pertinenza dell’Azienda Ospedaliera S. Antonio Abate di Gallarate, ossia l’Ospedale “S. Antonio Abate” di Gallarate, l’Ospedale “Carlo Ondoli” di Angera e l’Ospedale “Angelo Bellini” di Somma Lombardo, ed è stata ideata, elaborata e periodicamente verificata in collaborazione con il Prof. Mario Picozzi ed il Prof. Marco Cosentino dell’Università degli Studi dell’Insubria, e con le Dott. sse Giovanna Monina, Maristella Ghiringhelli e Raissa Mariani dell’Unità Operativa di Farmacia dell’Azienda Ospedaliera.
Lo studio, svolto grazie ai dati forniti dal Comitato Etico di Gallarate, vuole rappresentare uno spunto per valutare e successivamente discutere alcuni aspetti fondamentali dell’argomento scelto, quali l’authorship e l’accesso ai risultati da parte degli sperimentatori, partendo dalle interviste che sono state loro proposte, e di individuare ed analizzare altri lavori recentemente pubblicati.
L’indagine rappresenta però anche uno spunto per affrontare gli elementi di un dibattito etico molto acceso sorto intorno ad alcune pratiche di pubblicazione, fiorite negli ultimi decenni, che sono ricomprese nella misconduct, e delle quali varie iniziative, specialmente di carattere normativo, cercano di arginare la diffusione, tramite la produzione di nuove regolamentazioni, che finora hanno prodotto risultati incerti
I limiti delle risorse e le aspettative dei cittadini in sanità: un equilibrio possibile attraverso l'ascolto?
Full text linkmissin
Diffusion equations and inverse problems regularization.
Full text linkThe present thesis can be split into two dfferent parts:
The first part mainly deals with the porous and fast diffusion equations.
Chapter 2 presents these equations in the Euclidean setting highlighting the technical issues that arise when trying to extend results in a Riemannian setting. Chapter 3 is devoted to the construction of exhaustion and cut-o_ functions with controlled gradient and Laplacian, on manifolds with Ricci curvature bounded from below by a (possibly unbounded) nonpositive function of the distance from a fixed reference point, and without any assumptions on the topology or the injectivity radius. The cut-offs are then applied to the study of the fast and porous media diffusion, of Lq-properties of the gradient and of the selfadjointness of Schrödinger-type operators.
The second part is concerned with inverse problems regularization applied to image deblurring. In Chapter 5 new variants of the Tikhonov filter method, called fractional and weighted Tikhonov, are presented alongside their saturation properties and converse results on their convergence rates. New iterated fractional Tikhonov regularization methods are then introduced. In Chapter 6 the modified linearized Bregman algorithm is investigated. It is showed that the standard approach based on the block circulant circulant block preconditioner may provide low quality restored images and different preconditioning strategies are then proposed, which improve the quality of the restoration
Tumour Infiltrating (TINK) and Tumour Associated (TANK) Natural Killer cells: role in colorectal cancer (CRC) progression and angiogenesis.
Full text linkTumor infiltrating immune cells often show a skewed phenotype that reflects attenuation of anti- tumor activity and enhancement of pro-tumor and pro-angiogenic activities. We previously reported that NKs from Non Small Cell Lung Cancer patients are able to acquire the decidual-like CD56+CD16-VEGFhighPlGFhighIL- 8+IFNlow phenotype and promote angiogenesis in vitro. Here, we extended our findings to colorectal cancer (CRC) to verify whether the TINK/TANK polarization may represent a crucial hallmark of solid tumours. We found that CD56+CD16- NK cells predominate in CRC adjacent and tumor tissues, show decreased NKG2D surface expression and impaired cytotoxicity. Further, TINK/TANKs from CRC patients express the decidual NK markers CD9 and CD49a. Secretomic and flow cytometry on CRC peripheral blood NK cells revealed the up-regulation of several pro-angiogenic factors. Molecularly, the STAT-3 and STAT-5 pathway activation was observed in TANKs, suggesting the potential involvement of these signaling pathways in the angiogenic switch. CM by FACS sorted NKs from CRC patients were able to induce HUVEC proliferation, migration, adhesion and the formation of capillary like structures. These functional alterations are related with molecular changes in HUVECs, that include the phosphorylation of AMPKα, GSK-3, P70 S6 Kinase and S6 ribosomal protein. Our data demonstrate that TINK/TANKS from CRC patients are switched toward a proangiogenic/ pro-tumor phenotype and function. We propose that TINK/TANKs could represent a relevant biomarker for CRC progression
Secure execution of collaborative processes
No full textSo far the number of users on the social network sites has been increasing year-on-year. In the meanwhile, the price of mobile devices drops vertically. Both events push up vigorously the quantity of social users who use mobile devices. This results in a need for collaboration among mobile social users to attain the common goals. The fact that the huge number of users goes online lifts forcefully up the number of services over the Internet. The user requirements for services then get more complex. As a consequence, responding such a complex service request needs a composition of several single services.
However, the collaboration among several participants can make the personal data disclosed to the other sides during the collaborative process. Despite the fact that all participants comply with the common protocol and agree on contributing their personal data, they do not trust adequately in each other. This leads to the requirement of preserving user privacy and securing the user data against the other sides.
In this dissertation, we investigate different collaboration and participant types. More specifically, they are centralized and decentralized models among users/services. We also concern the communication environment, e.g., mobile network, Internet, or mobile ad-hoc network. The protocols that are enforced in a mobile network environment have more rigorous constraints due to limited physical and performance resources. For preserving user privacy and data security, we study and select different rational and effective cryptography algorithms then apply them into the collaborative protocols. For more understanding, we propose several collaboration scenarios and present them in detail in the upcoming chapters. Each scenario describes a combination of different collaborative type, participant type and network environment. For each scenario, we address issues on privacy preserving and data security and propose selective solutions. In addition, we propose methods for improving network performance. The experimental results show that our proposals are efficient and effective
