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The aim of this study has been to investigate the potential of the graphical calculator for mediating students' learning of functions in mathematics at GCE Advanced level. In carrying out this investigation, the study has been primarily concerned with three inter-related themes: How does the way in which individual students behave affect the shared construction of meaning in a graphical calculator environment? How does the visual imagery provided by the graphical calculator mediate students' understanding of functions? What are the implications for the role of the teacher in graphical calculator environments? In order to address these issues, the study has involved the development of materials and approaches that were subsequently trialled with Lower Sixth form students in a school and a college in the Local Education Authority of Sheffield. An ethnographic approach towards data collection and analysis was adopted, which entailed carrying out detailed studies of singularities in three key phases. The first phase consisted of the exploratory study and considered the learning experiences of novice graphical calculator users. The second phase involved experienced graphical calculator users and was concerned with identifying how knowledge construction might differ as a result of the longer-standing status of the graphical calculator as a tool for supporting mathematics learning. The third and final phase concentrated on the introduction of key function concepts to beginning Advanced level mathematics students and focused on the personal and social factors involved. The findings of this study have served to illustrate both the complexity and interdependence of the individual, social and affective factors involved in students' acquisition of meaning with the graphical calculator. Evidence from the research suggests that the social context has direct bearing on the functioning of the graphical calculator as a cognitive reorganiser. The graphical calculator was found to mediate the development of the visual capabilities of individual students via more intensive interaction between the students themselves and with the teacher. In this respect, the pairing of visualisers and non-visualisers amongst the students was found to be especially conducive to successful collaborative learning with the technology. In this study the graphical calculator acted as both a medium for communication and also as a new authority in the classroom, which empowered students to act as autonomous and independent learners. The potential of the technology for inspiring confidence, even in instances where it is not the main source of answers was also highlighted. An important part of successfully introducing new function concepts to students was found to lie in the creation of local communities of practice in the classroom, where the graphical calculator was seen as a means of drawing students into these practices. In this way, some of the more reluctant participants were encouraged to act as peer tutors. The importance of the role of the teacher in scaffolding the students' learning was also continually emphasised throughout, especially in relation to the interpretation of unexpected results and instances of dependency on the technology, which were linked to individual work. In illuminating all of these factors, the study has demonstrated the strength and relevance of a Vygotskian socio-cultural perspective for exploring students' learning with graphical calculators.

Prussian blue (PB) nanoparticles were synthesized from FeCl3.6H2O, K4[Fe(CN)6].3H2O, and from Fe(NO3)3.9H2O and K4[Fe(CN)6].3H2O, and then characterized by Fourier transform infrared (FT-IR), Ultraviolet-visible spectroscopy, X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS), Scanning electron microscopy (SEM), Raman spectroscopy and thermogravimetric analysis. Graphene oxide and carbon nanotubes were also synthesized and characterized. PB nanoparticles, carbon nanotubes (CNT), graphene oxide (GO) and cetyltrimethylammonium bromide (CTAB) were sequentially deposited onto glassy carbon electrode surface to form chemically modified electrode for the detection of hydrogen peroxide (H2O2) and dopamine. The following electrodes were fabricated, GC-PB, GC-MWCNT, GCGO, GC-CTAB, GC-MWCNT-PB, GC-GO-PB and GC-CTAB-PB. Cyclic and Square wave voltammetric techniques were used to measure the hydrogen peroxide detectability of the electrodes at pH ranges of (3 - 7.4) in 0.1M phosphate buffer solution, in the absence or presence of 25 μL of H2O2. The GC-CNT-PB, GC-GO-PB,GC-CTAB-PB electrodes showed a good response for the detection of hydrogen peroxide in both acidic and neutral media while the GCPB electrode only showed good response in acidic media.

Since culturally diverse people need to collaborate in the 21st century, Higher Education adopted global citizenship education (GCE) to promote a cosmopolitan mindset. Learners in the digital era can use various modes of communication, exerting individual agency so that learners can construct global minds through their communication experiences. Blended learning based on learner-centered knowledge construction may provide extended spaces where learners can shape a personally trusted and collectively consensual vision of the global mind. A qualitative evaluation case study explored learners' perception shifts regarding autonomous identity formations and confidence-trust-building in a blended course under GCE. Due to the Covid-19 pandemic, semi-structured in-depth online interviews and document analyses on the archive data were adopted to triangulate learners' perceptions and instructors' observations. Findings showed that individuals could shape their global citizen identities through a performative loop of reflection and interaction provided via a blended format. The participants' comfort zone levels influenced different identity formation paths. However, their goals, in the end, were aligned under the idea of engaging in local community activities through lifelong commitment. Intrapersonal and interactional forms of communication solidified self-confidence and collective trust through synergically linked blended learning activities. Overall, global citizen identities have gradually evolved while self-confidence and trust in others have gradually increased through different communication steps. The significance of the study lies in reinforcing the results of prior research about performativity-oriented GCE through a community of people practicing in blended learning environments. Members' hands-on activities while building self-confidence and collective trust through communication helped them shape their collective identity. In these processes, individuals' intrapersonal communication seemed to play an insightful role in effectively connecting reflective and interactive activities. Enhanced credibility by replicating this GCE model in future studies will ensure various organizations and institutions adopt it to shape their members' global visions and build group cohesion.

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Thesis advisor: Abhishek Chatterjee / The study of protein structure and function has advanced significantly with the development of genetic code expansion (GCE) technology for the incorporation of noncanonical amino acids (ncAAs), revolutionizing synthetic biology by enabling the introduction of novel functionalities into proteins. Within eukaryotic systems, these advancements have paved the way for deeper investigations into complex protein functions critical to human biology and have spurred the development of innovative biotherapeutic solutions.The work described within this dissertation has aimed to further advance various applications of mammalian GCE. This includes the construction of next-generation homogenous antibody-drug conjugates (ADCs) both using a genetically encoded photocaged cysteine and with a dual incorporation system for the construction of a dual-drug conjugate. Multiple new platforms were developed for the incorporation of two or even three ncAAs within a single protein, utilizing a novel aaRS/tRNA pair and evolved hyper-efficient tRNAs. GCE-enabled precise protein modification was also utilized to spectroscopically study the conformational dynamics of dimeric EGFR. Additionally, platforms were established for the precise installation of post-translational modification (PTM) mimics within mammalian proteins, allowing for their programmed activation. Finally, an innovative strategy for the study of protein-protein interactions using genetically encoded photocrosslinkers was developed. Collectively, these efforts have contributed to the development of novel tools for studying protein function in mammalian cells and advancing the creation of new biotherapeutics through GCE technology. / Thesis (PhD) — Boston College, 2024. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

<p>This dissertation examines the impact of the expansion of renewable technology at both national and local level, through distinct essays. At the national level, the first paper analyzes the effects of economic and distributional impacts of climate mitigation policy, in the context of a developing country, to understand the interactions between the energy system and the macroeconomic environment. In the case of the local level, the second paper uses synthetic control method, to estimate the effect at the county level of utility scale wind in the development indicators for two counties in the U.S. </p> <p>The first paper assesses the economic and distributional impacts of Nicaragua’s commitments to limit future greenhouse gas emissions in the context of the Paris Agreement, known as the Nationally Determined Contributions (NDCs). The analysis relies on two distinct models. The first is a top-down approach based on a single-country computable general equilibrium (CGE) model, known as the Mitigation, Adaptation and New Technologies Applied General Equilibrium (MANAGE) Model. The second is a bottom-up approach based on the Open-Source energy Modeling System (OSeMOSYS), which is technology rich energy model. The combined model is calibrated to an updated social accounting matrix for Nicaragua, which disaggregates households into 20 representative types: 10 rural and 10 urban households. For the household disaggregation we have used information from the 2014 Living Standards Measurement Study (LSMS) for Nicaragua. Our analysis focuses on the distributional impacts of meeting the NDCs as well as additional scenarios—in a dynamic framework as the MANAGE model is a (recursive) dynamic model. The results show that a carbon tax has greatest potential for reduction in emissions, with modest impact in macro variables. An expansion of the renewable sources in the electricity matrix also leads to significant reduction in emissions. Only a carbon tax achieves a reduction in emissions consistent with keeping global warming below 2°C. Nicaragua’s NDC alone would not achieve the target and mitigation instruments are needed. An expansion of generation from renewable sources, does not lead to a scenario consistent with a 2°C pathway. </p> <p>The second paper measures the impact of wind generation on county level outcomes through the use of the Synthetic Control Method (SCM). SCM avoids the pitfalls of other methods such as input-output models and project level case studies that do not provide county level estimates. We find that the local per capita income effect of utility wind scale is 6 percent (translate into an increase of $1,511 in per capita income for 2019) for Benton County and 8 percent for White county in Indiana (an increase of $2,100 in per capita income for 2019). The per capita income effect measures the average impact, which includes the gains in rents from capital, land, and labor from wind power in these counties. Moreover, we find that most of the rents from wind power accrue to the owners of capital and labor. Even assuming the lowest projections of electricity prices and the highest reasonable cost we still find a 10 percent minimum rate of return to capital for both Benton and White counties’ wind power generators. Furthermore, we find that there are excess rents that could be taxed and redistributed at the county, state, or federal level without disincentivizing investment in wind power.</p>

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