Una prospettiva storico-filosofica sull'evoluzione del curricolo di fisica nella scuola: problemi e innovazioni pedagogiche

Negli ultimi vent’anni sono state proposte al livello internazionale alcune analisi dei problemi per le scienze nella scuola e diverse strategie per l’innovazione didattica. Molte ricerche hanno fatto riferimento a una nuova nozione di literacy scientifica, quale sapere fondamentale dell’educazione, indipendente dalle scelte professionali successive alla scuola. L’ipotesi di partenza di questa ricerca sostiene che alcune di queste analisi e l’idea di una nuova literacy scientifica di tipo non-vocazionale mostrino notevoli limiti quando rapportate al contesto italiano. Le specificità di quest’ultimo sono state affrontate, innanzitutto, da un punto di vista comparativo, discutendo alcuni documenti internazionali sull’insegnamento delle scienze. Questo confronto ha messo in luce la difficoltà di ottenere un insieme di evidenze chiare e definitive sui problemi dell’educazione scientifica discussi da questi documenti, in particolare per quanto riguarda i dati sulla crisi delle vocazioni scientifiche e sull’attitudine degli studenti verso le scienze. Le raccomandazioni educative e alcuni progetti curricolari internazionali trovano degli ostacoli decisivi nella scuola superiore italiana anche a causa di specificità istituzionali, come particolari principi di selezione e l’articolazione dei vari indirizzi formativi. Il presente lavoro si è basato soprattutto su una ricostruzione storico-pedagogica del curricolo di fisica, attraverso l’analisi delle linee guida nazionali, dei programmi di studio e di alcuni rappresentativi manuali degli ultimi decenni. Questo esame del curricolo “programmato” ha messo in luce, primo, il carattere accademico della fisica liceale e la sua debole rielaborazione culturale e didattica, secondo, l’impatto di temi e problemi internazionali sui materiali didattici. Tale impatto ha prodotto dei cambiamenti sul piano delle finalità educative e degli strumenti di apprendimento incorporati nei manuali. Nonostante l’evoluzione di queste caratteristiche del curricolo, tuttavia, l’analisi delle conoscenze storico-filosofiche utilizzate dai manuali ha messo in luce la scarsa contestualizzazione culturale della fisica quale uno degli ostacoli principali per l’insegnamento di una scienza più rilevante e formativa.

Reconceptualising professional development in early childhood education. A study on teachers' professionalism carried out in Bologna province.

The research undertaken for this doctoral thesis explores the issue of teachers professionalism within pre-school institutions. The issue of early childhood professionalism has become increasingly important in the academic debate over the last decade as it is documented by a growing body of research published on the topic both nationally (Contini & Manini, 2007; Bondioli & Ferrari, 2004) and internationally (Peeters, 2008; Urban & Dalli, 2008; Urban, 2010). The study presented in this thesis aims at investigating teachers’ conceptualisations of professionalism by focusing on their understandings of educational work. The idea standing at the core of this research is that exploring the concept of professionalism from a ground-up perspective could lead to important reflections for a re-conceptualisation of professional development as a space for change directed from within institutions. The study is framed within a broadly sociological concern that inform the data analysis by contextualising the issue of early childhood professionalism in the contemporary socio-political arena. The research involves sixty teachers operating in state, municipal and private pre-school institutions located in Bologna province that took part to focus groups and interviews. The empirical materials, consisting of oral and written statements, are interpreted through phenomenographical analysis that gives account of how features of professionalism vary across the different institutional settings in which they are played out. This thesis, written in English and informed by an European research background, offers a contribution to the furthering of systemic approaches to the investigation of early childhood education professionalism in the context of the national and international academic debate.

Analysis of charge-transport properties in GST materials for next generation phase-change memory devices

The quest for universal memory is driving the rapid development of memories with superior all-round capabilities in non-volatility, high speed, high endurance and low power. The memory subsystem accounts for a significant cost and power budget of a computer system. Current DRAM-based main memory systems are starting to hit the power and cost limit. To resolve this issue the industry is improving existing technologies such as Flash and exploring new ones. Among those new technologies is the Phase Change Memory (PCM), which overcomes some of the shortcomings of the Flash such as durability and scalability. This alternative non-volatile memory technology, which uses resistance contrast in phase-change materials, offers more density relative to DRAM, and can help to increase main memory capacity of future systems while remaining within the cost and power constraints. Chalcogenide materials can suitably be exploited for manufacturing phase-change memory devices. Charge transport in amorphous chalcogenide-GST used for memory devices is modeled using two contributions: hopping of trapped electrons and motion of band electrons in extended states. Crystalline GST exhibits an almost Ohmic I(V) curve. In contrast amorphous GST shows a high resistance at low biases while, above a threshold voltage, a transition takes place from a highly resistive to a conductive state, characterized by a negative differential-resistance behavior. A clear and complete understanding of the threshold behavior of the amorphous phase is fundamental for exploiting such materials in the fabrication of innovative nonvolatile memories. The type of feedback that produces the snapback phenomenon is described as a filamentation in energy that is controlled by electron–electron interactions between trapped electrons and band electrons. The model thus derived is implemented within a state-of-the-art simulator. An analytical version of the model is also derived and is useful for discussing the snapback behavior and the scaling properties of the device.

Individuals in the Workplatform. Exploring Implications for Work Identity and Algorithmic Reputation Management

In the new world of work, workers not only change jobs more frequently, but also perform independent work on online labor markets. As they accomplish smaller and shorter jobs at the boundaries of organizations, employment relationships become unstable and career trajectories less linear. These new working conditions question the validity of existing management theories and call for more studies explaining gig workers’ behavior. Aim of this dissertation is contributing to this emerging body of knowledge by (I) exploring how gig workers shape their work identity on online platforms, and (II) investigating how algorithmic reputation changes dynamics of quality signaling and affects gig workers’ behavior. Chapter 1 introduces the debate on gig work, detailing why existing theories and definitions cannot be applied to this emergent workforce. Chapter 2 provides a systematic review of studies on individual work in online labor markets and identifies areas for future research. Chapter 3 describes the exploratory, qualitative methodology applied to collect and analyze data. Chapter 4 presents the first empirical paper investigating how the process of work identity construction unfolds for gig workers. It explores how digital platforms, intended both as providers of technological features and online environments, affect this process. Findings reveal the online environment constrains the action of workers who are pushed to take advantage of platform’s technological features to succeed. This interplay leads workers to develop an entrepreneurial orientation. Drawing on signaling theory, Chapter 5 understands how gig workers interpret algorithmic calculated reputation and with what consequences for their experience. Results show that, after complying to platform’s rules in the first period, freelancers respond to algorithmic management through different strategies – i.e. manipulation, nurturing relationships, and living with it. Although reputation scores standardize information on freelancers’ quality, and, apparently, freelancers’ work, this study shows instead responses to algorithmic control can be diverse.

Exploring novel targeted therapeutic strategies against Acute Myeloid Leukemia cells based on inhibition of bromodomain proteins and CDC20 activity

Acute myeloid leukemia (AML) is a haematological malignancies arising from the accumulation of undifferentiated myeloid progenitors with an uncontrolled proliferation. The genomic landscape of AML revealed that the disease is characterized by high level of heterogeneity and is subjected to clonal evolution driven by selective pressure of chemotherapy. In this study, we investigated the therapeutic effects of the inhibition of BRD4 and CDC20 in vitro and ex vivo. We demonstrated that inhibition of BRD4 with GSK1215101A in AML cell lines was effective under hypoxia. It induced the activation of antioxidant response both, at transcriptomic and metabolomic levels, driven by enrichment of NRF2 pathway under normoxic and hypoxic condition. Moreover, the combined treatment with Omaveloxolone, a drug inducing NRF2 activation and NF-κB inhibition, potentiated the effects on apoptosis and colony forming capacity of stem progenitor cells. Lastly, gene expression profiling data revealed that combination treatment induced major changes in genes related to cell cycle, together with enrichment of cell differentiation pathways and negative regulation of WNT, in normoxia and hypoxia. Regarding CDC20, we observed its up-regulation in AML patients. Treatment with two different inhibitors, Apcin and proTAME, was effective in primary AML cells and in AML cell lines, through induction of apoptosis and mitotic arrest. The lack of correlation between proliferation markers and CDC20 levels in AML cell subpopulations supports the idea of alternative CDC20 functions, independent from its essential role during mitosis. CDC20-KD experiments conducted in AML cell lines revealed a mild effect on apoptosis induction, but no significant change in cell cycle progression. In summary, these results allowed the identification of a new strategy combination to improve the effects of BRD4 inhibition on LSC residing in the BM hypoxic niche, and provide some new evidence regarding the potential role of CDC20 as a new target for AML treatment.

A study on the macroeconomics of climate change

This work aims at exploring the relationship between business cycles, having frequencies rooted in the short run, and climatic phenomena, which span longer time horizons. The ultimate goal is to provide a theoretical framework to address these questions: How could very long run considerations affect short run economic decisions? How short run and transitory decisions could exert a long lasting effect on climate? This is achieved by means of an off-the-shelf real business cycle (RBC) model augmented so as to include a climatic block. The economy is perturbed by a technology shock and an energy-price shock. In general, the model performs relatively well in reproducing the cyclical characteristics of the economic variables; however, it is not as successful in capturing the cyclical behavior of climatic variables. Finally, it proposes a set of policy experiments, all taking the form of an energy tax directly or indirectly linked to the climatic status. As a matter of fact the effect of any tax responsive to the business cycle shows positive aspects: when a technology shock hits the economy, it mitigates global warming with minor costs in terms of potential output losses. It also protects the economy from an increase in energy prices, sustaining a certain level of output despite the fall in fossil energy use.

Relationship between phenotype and environment in marine calcifying organisms: exploring growth and shell properties of different mollusks species in past and modern scenario

Coastal ecosystems represent an inestimable source of biodiversity, being among the most productive areas on the planet. Despite the great ecological and economic value of those environments, many threats endanger the species living in this ecosystem, like the rapid warming and the sea acidification, among many other. Benthic calcifying organisms (e.g. mollusks, corals and echinoderms) in particular, are among the most exposed to those hazards. These organisms use calcium carbonate as a structural and protective material through the biomineralization process, biologically controlled by the organism, but nevertheless, strongly influenced by the environmental surroundings. Evaluating how a changing environment can influence the process of biomineralization is critical to understand how those species of great ecological and economic importance will face the ongoing climate change. This thesis investigates the mechanism of biomineralization in different mollusks’ species of the Adriatic Sea, providing detailed descriptions of shells skeletal, biometric and growth parameters. Applying a multidisciplinary and multi-scale research approach, the influence of external environmental factors on the process of shell formation has been investigated. To achieve this purpose analysis were conducted both on current populations and on fossil remain, which allows to investigate ecological responses to past climate transitions. Mollusks’ shells in fact are one of the best tools to understand climate change in the past, present and future, since they record the environmental conditions prevailed during their life, reflected on the geochemical properties, microstructure and growth of the shell. This approach allowed to overcome the time scale limit imposed by field and laboratory survey, and better understand species long term adaptive response to changing environment, a crucial issue to define proper conservation and management strategies. Furthermore, the investigation of fossil record of mollusks assemblages offered the opportunity to evaluate the long-term biotic response to anthropogenic stressors in the north Adriatic Sea.