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Temporary teams learning and performance: the case of 3D printing technology in orthopaedic surgery
Get PDFThis dissertation contributes to the scholarly debate on temporary teams by exploring team interactions and boundaries.The fundamental challenge in temporary teams originates from temporary participation in the teams. First, as participants join the team for a short period of time, there is not enough time to build trust, share understanding, and have effective interactions. Consequently, team outputs and practices built on team interactions become vulnerable. Secondly, as team participants move on and off the teams, teams’ boundaries become blurred over time. It leads to uncertainty among team participants and leaders about who is/is not identified as a team member causing collective disagreement within the team.
Focusing on the above mentioned challenges, we conducted this research in healthcare organisations since the use of temporary teams in healthcare and hospital setting is prevalent. In particular, we focused on orthopaedic teams that provide personalised treatments for patients using 3D printing technology. Qualitative and quantitative data were collected using interviews, observations, questionnaires and archival data at Rizzoli Orthopaedic Institute, Bologna, Italy.
This study provides the following research outputs. The first is a conceptual study that explores temporary teams’ literature using bibliometric analysis and systematic literature review to highlight research gaps. The second paper qualitatively studies temporary relationships within the teams by collecting data using group interviews and observations. The results highlighted the role of short-term dyadic relationships as a ground to share and transfer knowledge at the team level. Moreover, hierarchical structure of the teams facilitates knowledge sharing by supporting dyadic relationships within and beyond the team meetings. The third paper investigates impact of blurred boundaries on temporary teams’ performance. Using quantitative data collected through questionnaires and archival data, we concluded that boundary blurring in terms of fluidity, overlap and dispersion differently impacts team performance at high and low levels of task complexity
The Hitchin map for one-nodal base curves of compact type
Get PDFStudying moduli spaces of semistable Higgs bundles (E, \phi) of rank n on a smooth curve C, a key role is played by the spectral curve X (Hitchin), because an important result by Beauville-Narasimhan-Ramanan allows us to study isomorphism classes of such Higgs bundles in terms of isomorphism classes of rank-1 torsion-free sheaves on X. This way, the generic fibre of the Hitchin map, which associates to any semistable Higgs bundle the coefficients of the characteristic polynomial of \phi, is isomorphic to the Jacobian of X. Focusing on rank-2 Higgs data, this construction was extended by Barik to the case in which the curve C is reducible, one-nodal, having two smooth components. Such curve is called of compact type because its Picard group is compact.
In this work, we describe and clarify the main points of the construction by Barik and we give examples, especially concerning generic fibres of the Hitchin map. Referring to Hausel-Pauly, we consider the case of SL(2,C)-Higgs bundles on a smooth base curve, which are such that the generic fibre of the Hitchin map is a subvariety of the Jacobian of X, the Prym variety. We recall the description of special loci, called endoscopic loci, such that the associated Prym variety is not connected. Then, letting G be an affine reductive group having underlying Lie algebra so(4,C), we consider G-Higgs bundles on a smooth base curve. Starting from the construction by Bradlow-Schaposnik, we discuss the associated endoscopic loci.
By adapting these studies to a one-nodal base curve of compact type, we describe the fibre of the SL(2,C)-Hitchin map and of the G-Hitchin map, together with endoscopic loci.
In the Appendix, we give an interpretation of generic spectral curves in terms of families of double covers
Propagation modelling and resource allocation in mobile radio communications
Get PDFOver the past years, ray tracing (RT) models popularity has been increasing. From
the nineties, RT has been used for field prediction in environment such as indoor
and urban environments. Nevertheless, with the advent of new technologies, the
channel model has become decidedly more dynamic and to perform RT simulations
at each discrete time instant become computationally expensive. In this thesis, a new
dynamic ray tracing (DRT) approach is presented in which from a single ray tracing
simulation at an initial time t0, through analytical formulas we are able to track
the motion of the interaction points. The benefits that this approach bring are that
Doppler frequencies and channel prediction can be derived at every time instant,
without recurring to multiple RT runs and therefore shortening the computation
time. DRT performance was studied on two case studies and the results shows the
accuracy and the computational gain that derives from this approach.
Another issue that has been addressed in this thesis is the licensed band exhaustion of some frequency bands. To deal with this problem, a novel unselfish
spectrum leasing scheme in cognitive radio networks (CRNs) is proposed that offers
an energy-efficient solution minimizing the environmental impact of the network. In
addition, a network management architecture is introduced and resource allocation
is proposed as a constrained sum energy efficiency maximization problem. System
simulations demonstrate an increment in the energy efficiency of the primary users’
network compared with previously proposed algorithms
Development and food security in africa from the 1960s to 2010s: the case of Ethiopia
Get PDFPersistent food insecurity and famines have continued to significantly shape the development policies of Ethiopia for decades. Over the decades, frequent famines caused not only the death of hundreds of thousands of victims but also significantly contributed to two revolutions that swept away the Haile Selassie and Derg regimes, as well as significantly taxing the legitimacy of the incumbent regime. As a result, agriculture and food security have become increasingly the top policy priorities for all political regimes in Ethiopia. However, the development policies of the ruling elites of Ethiopia have consistently failed to transform backward agriculture and ensure food security. The failures of the development policies of the Ethiopian governments over the years were attributed to several factors. Ethiopian authoritarian politics, centralized rule with a lack of transparency and accountability; the isolation of peasants from the development and governance process, and the lack of coherent agricultural development strategies that invest in peasant agriculture and create synergy among sectors are identified as key issues that have contributed to the persistence of food insecurity in the country. The literature on the failure of Ethiopia's political regimes to address food insecurity and famine has two major gaps that this study aims to fill. First, the cumulative and path-dependent food security and agricultural development policy environment were not adequately considered. Second, the strategy of extraversion by subsequent political regimes to use external support as a relief to prevent the famine-induced political crisis. This study used a mixed approach to collect data and present the evolution of the interplays of development policies and food security in three regimes within the context of international food security discourses. This study found out how the historical patterns of approaches of Ethiopia’s regimes to development and governance led to frequent famines and persistent food insecurity
Investigation of innovative combustion systems for reduced fuel consumption and increased specific power production
Get PDFThis work resumes a wide variety of research activities carried out with the main objective of increasing the efficiency and reducing the fuel consumption of Gasoline Direct Injection engines, especially under high loads. For this purpose, two main innovative technologies have been studied, Water Injection and Low-Pressure Exhaust Gas Recirculation, which help to reduce the temperature of the gases inside the combustion chamber and thus mitigate knock, being this one of the main limiting factors for the efficiency of modern downsized engines that operate at high specific power.
A prototypal Port Water Injection system was developed and extensive experimental work has been carried out, initially to identify the benefits and limitations of this technology. This led to the subsequent development and testing of a combustion controller, which has been implemented on a Rapid Control Prototyping environment, capable of managing water injection to achieve knock mitigation and a more efficient combustion phase.
Regarding Low-Pressure Exhaust Gas Recirculation, a commercial engine that was already equipped with this technology was used to carry out experimental work in a similar fashion to that of water injection. Another prototypal water injection system has been mounted to this second engine, to be able to test both technologies, at first separately to compare them on equal conditions, and secondly together in the search of a possible synergy.
Additionally, based on experimental data from several engines that have been tested during this study, including both GDI and GCI engines, a real-time model (or virtual sensor) for the estimation of the maximum in-cylinder pressure has been developed and validated. This parameter is of vital importance to determine the speed at which damage occurs on the engine components, and therefore to extract the maximum performance without inducing permanent damages
Microenvironment and prognostic factors in bone tumors: IDH mutations in chondrosarcoma
Get PDFMicroenvironment in bone tumors is a dynamic entity composed of cells from different origins (immune cells, stromal cells, mesenchymal stem cells, endothelial cells, pericytes) and vascular structures surrounded by a matrix of different nature (bone, cartilage, myxoid).
Interactions between cancer cells and tumor microenvironment (TME) are complex and can change as tumor progress, but are also crucial in determining response to cancer therapies.
Chondrosarcoma is the second most frequent bone cancer in adult age, but its treatment still represents a challenge, for the intrinsic resistance to conventional chemotherapy and radiation therapy. This resistance is mainly due to pathological features, as dense matrix, scarce mitoses and poor vascularization, sustained by biological mechanisms only partially delucidated.
Somatic mutation in the Krebs cycle enzyme isocytrate dehydrogenase (IDH) have been described in gliomas, acute myeloid leukemia, cholangiocarcinoma, melanoma, colorectal, prostate cancer, thyroid carcinoma and other cancers. In mesenchymal tumors IDH mutations are present in about 50% of central chondrosarcoma. IDH mutations are an early event in chondrosarcoma-genesis, and contribute to the acquisition of malignancy through the block of cellular differentiation, hypoxia induction through HIF stabilization, DNA methylation and alteration of cellular red-ox balance.
While in gliomas IDH mutations confers a good prognosis, in chondrosarcoma IDH prognostic role is controversial in different reported series.
First aim of this project is to define the prevalence and the prognostic role of IDH mutation in high grade central conventional chondrosarcoma patients treated at Istituto Ortopedico Rizzoli.
Second aim is the critical revision of scientific literature to understand better how a genomic event in cancer cell can trigger alteration in the TME, through immune infiltrate reshaping, angiogenesis induction, metabolic and methylation rewiring.
Third aim is to screen other sarcoma histotypes for the presence of IDH mutation
Cytotoxic effect of immunotoxins in 2D and 3D models of sarcoma
Get PDFSarcomas are one of the most common types of cancer in children and comprise more than 50 heterogeneous histotypes. The standard therapeutic regimen, which includes surgery, chemotherapy and radiotherapy, does not often prove to be decisive. To improve patient outcome, alternative therapeutic strategies are being evaluated. Among these, RIP-containing immunotoxins (ITs) represent an innovative approach because of their high tumor specificity and cytotoxicity. Recently, in order to evaluate the efficacy of new drugs and develop personalized therapeutic protocols, three-dimensional models (i.e. spheroids and organoids) are emerging as valid tools in cancer research. My PhD project aimed to evaluate the cytotoxic effect of specific ITs, Tf-SO6, αEGFR1-Ocy and αHer2-Ocy, directed against TfR1, EGFR1 and Her2, in 2D (adherent cells) and 3D models (spheroids and organoids) of sarcoma. The results obtained showed that TfR1, EGFR1 and Her2 are highly expressed in our sarcoma models, and could be a possible target for immunotherapy. All tested ITs showed high specific cytotoxicity in 2D and 3D models, with IC50 values in nM range. Caspase 3/7 are highly activated after IT treatments in all cell models, but with different timing
Comparison of paper conservation methods between Italy and China: scientific investigations and restoration techniques for paper material
Get PDFI metodi di conservazione per i materiali cartacei in Italia e in Cina sono nati in diversi contesti storici. L’idea di questo studio nasce dalla necessità di sviluppare analisi specifiche sul metodo di restauro cartaceo cinese, per introdurre metodi e tecnologie efficaci ed innovative.The conservation methods for paper materials in Italy and China were born in different historical contexts. The idea of this study stems from the need to develop specific analyzes on the Chinese paper restoration method, to introduce effective and innovative methods and technologies
Surveys as a tool to investigate attitudes towards health services and COVID-19 pandemic.
Get PDFLe indagini campionarie sono diventate una componente essenziale nella ricerca sanitaria e sono particolarmente utili quando si valutano costrutti che richiedono un’autovalutazione individuale su conoscenze, opinioni, atteggiamenti e comportamenti. Hanno un’ampia accessibilità alla popolazione target, soprattutto quando questa è rappresentata dalla popolazione generale, permettono di raggiungere un’ampia dimensione campionaria e di raccogliere grandi quantità di informazioni in tempi relativamente brevi. Tuttavia condurre un’indagine di buona qualità è più complesso di quanto sembri. I metodi utilizzati possono infatti influenzare significativamente l'affidabilità e la generalizzabilità dei risultati. Questa tesi descrive l’impiego delle indagini campionarie in tre studi volti ad indagare: 1) le conoscenze degli studenti di medicina in materia di misure di prevenzione, la percezione del rischio di contagio e la correlazione con la formazione ricevuta, inclusa l’attività di volontariato svolta durante la pandemia da COVID-19; 2) l’atteggiamento dei cittadini emiliano-romagnoli nei confronti della vaccinazione contro COVID-19 e i fattori associati all’esitazione; 3) la fiducia nel sistema sanitario, la qualità percepita e l’utilizzo dei servizi sanitari, e come questi aspetti siano legati tra loro ed alle caratteristiche della popolazione italiana. Nel capitolo finale le tre indagini sono messe a confronto dal punto di vista metodologico, al fine di trarre insegnamenti utili per un’applicazione più appropriata alla ricerca in sanità pubblica. Da tale confronto si evince che la pianificazione e la conduzione delle indagini presuppongono una serie di scelte metodologiche che devono tener conto dell’obiettivo conoscitivo ma anche delle tempistiche e delle risorse disponibili. La letteratura come punto di partenza e il coinvolgimento di un team multidisciplinare sono fondamentali per lo sviluppo di indagini che rispondano efficacemente al quesito di ricerca generando evidenze affidabili. Le stime prodotte dalle indagini campionarie possono essere utilizzate per monitorare i progressi verso il raggiungimento degli obiettivi di salute ed individuare gli aspetti su cui indirizzare gli sforzi.Surveys have become an essential component in health research and are particularly useful when evaluating constructs that require individual self-assessment of knowledge, opinions, attitudes and behaviors. They have a wide accessibility to the target population, especially when this is represented by the general population, they can potentially reach a large sample size and collect large amounts of information in a relatively short time. However, conducting a good quality survey is more complex than it seems. Indeed, the methods used can significantly affect the reliability and generalizability of the results. This dissertation describes the use of survey in three studies aimed at investigating: 1) knowledge of prevention measures, perception of contagion risk and the correlation with training received, including volunteering during the COVID-19 pandemic, among medical students; 2) the attitude of Emilia-Romagna citizens towards vaccination against COVID-19 and the factors associated with hesitation; 3) trust in the healthcare system, perceived quality and use of health services, and how these aspects are linked to each other and to the Italian population’s characteristics. In the final chapter, the three surveys are compared from a methodological point of view, in order to draw useful lessons for a more appropriate application to research in public health. This comparison highlights how survey planning and conduction imply several methodological choices that must consider the research objective as well as timing and available resources. A literature review and the involvement of a multidisciplinary team are key ingredients for planning effective surveys, answering the research question and producing reliable evidence. The estimates provided by the surveys can be used to monitor progresses towards the achievement of health objectives and to identify aspects towards which efforts should be directed
The maternal government of the democratic movement. Women and family in Tocqueville and Beaumont.
Get PDFAttraverso un’analisi storico-concettuale, questa ricerca indaga la funzione sociale e politica attribuita alle donne e alle famiglie da Alexis de Tocqueville e Gustave de Beaumont. Esaminando la costruzione di ideali di femminilità specifici nelle opere dei due autori, si mette a tema la subordinazione della donna come fondamento del governo della democrazia liberale, per far emergere il fulcro patriarcale delle logiche del potere politico e sociale moderno nel quadro della rivoluzione del mercato. Guardando alla circolazione atlantica e coloniale dei concetti moderni e focalizzandosi sulla centralità degli Stati Uniti, dell’Algeria e dei Caraibi francesi nella definizione di un ordine all’altezza delle sfide poste dal processo rivoluzionario in Francia e dal capitalismo industriale, si mostra la necessità del riferimento alla donna come paradigma della moderazione, fondato sulla definizione sessuata delle virtù, e come strumento di contenimento del conflitto sociale. L’indagine su questo tema mostra la rilevanza della riflessione di Gustave de Beaumont, il cui romanzo-saggio Marie funge da contraltare delle riflessioni proposte da Tocqueville ne La democrazia in America, mentre L’Irlande e i contributi sull’Algeria e sul 1848 suggeriscono la necessità di pensare congiuntamente ordine familiare e ordine sociale. Ricostruendo la contesa - di cui i due autori sono parte - sulla differenza sessuale e sull’uguaglianza, emerge il suo legame con la necessità di una scienza politica che incida sull’inarrestabile rivoluzione democratica, e quindi sul futuro della civilizzazione. In un orizzonte articolato da molteplici temporalità rivoluzionarie, che mettono in tensione i concetti di eguaglianza, libertà, proprietà e fratellanza, la donna democratica funge da stabilizzatrice delle società e da garante tanto del rapporto politico tra individui e Stato, quanto delle esigenze del mercato globale, a fronte della crisi, già in atto, della figura di individuo proprietario e lavoratore.Through a historical-conceptual analysis, this research investigates the social and political function ascribed to women and families by Alexis de Tocqueville and Gustave de Beaumont. By examining the construction of specific ideals of womanhood in the writings of the two authors, this work thematizes the subordination of women as a cornerstone of the government of liberal democracy, to bring out the patriarchal fulcrum of the logics of modern political and social power in the context of the market revolution. Looking at the Atlantic and colonial circulation of modern concepts as central to the definition of an order at the height of the challenges posed by the revolutionary process in France and by industrial capitalism, the research shows that woman is understood as a paradigm of moderation, based on the gendered definition of virtues, and as a tool for the containment of social conflict. The investigation of this theme shows the relevance of the reflection of Gustave de Beaumont, whose novel-essay Marie serves as a counterbalance to the reflections proposed by Tocqueville in Democracy in America; L'Irlande and the contributions on Algeria and on the 1848 Revolution suggest the need to think jointly about family order and social order. By reconstructing the dispute over sexual difference and equality, it emerges its connection to the need for a political science to deal with the unstoppable democratic revolution, and thus with the future of civilization. In a horizon articulated by multiple revolutionary temporalities, which challenge the concepts of equality, freedom, property and brotherhood, the democratic woman operates as a stabilizer of societies and as a protector both of the political relationship between individuals and the state, and of the needs of the global market, facing the crisis, already underway, of the figure of the individual owner and worker