VictorJuiz/thesis huggingface dataset:
Social bonding among children in joint physically active play
Keywords: Physical Activity
Touch
Play
Social bonding

Children’s free play is often characterised by moderate-to-vigorous physical activity (MVPA), touch, joint action, and enjoyment. Each of these features has been associated with interpersonal affiliation in either human or non-human primates. However, no research has examined how children’s joint physically active play is linked with social bonding (i.e., positive emotional states and behaviours that help create, maintain, and characterise affiliation and attachment among individuals). This thesis comprises three novel studies that were designed to explore this question. A naturalistic observation study (N = 50) was first conducted to assess links among physical activity (PA), smiling/laughing, touch, and prosociality in children’s play behaviour during school breaks. PA levels were also measured indirectly via heart rate monitors (HRM). We found that observed-PA was associated with frequency of smiling/laughing between pairs. PA (observed and HRM) was also associated with frequency of touch. A second study (N = 84) experimentally tested the effect of touch on helping behaviour in the context of physically-active play. In pairs, children ran to collect felt shapes, which they placed either onto each other (touch condition) or onto a board (no-touch condition). Subsequent helping behaviour was assessed in a separate task. There was a non-significant trend towards more helping in the touch condition. The final study (N = 252) tested the effect of physical exertion on children’s social bonding and behavioural inhibition. In pairs, children either ran (MVPA condition) or walked (light PA condition) around an area laid out with mats. One child could choose to stand either on the same mat as the other child and do actions together or stand on separate mats and do the actions separately. This was followed by a pictorial measure of social closeness, followed by a behavioural inhibition task in which one child was instructed to place their hand inside a box containing unknown stimuli. No significant differences were detected between the two conditions. The thesis contributes to filling in gaps within the literature on play, social bonding, and physical activity, spanning evolutionary anthropology, developmental psychology, and health, and highlights the need for more controlled experimental studies among diverse populations.
Atom probe tomography of crystallographic defects in silicon
Keywords: Atom Probe Tomography
Silicon
Grain Boundaries
Correlative Microscopy
Hydrogen

High performance multicrystalline silicon (HPMC-Si) is the dominant material used in photovoltaic (PV) devices. This material however contains a large number of defects, such as grain boundaries and dislocations. The decoration of such defects by transition metals and other impurities causes deep levels in the band gap, significantly affecting the performance and efficiency of PV devices. In the photovoltaic industry, processing techniques, such as hydrogen passivation and gettering, are used to increase the minority carrier lifetime, reducing the recombination activity of crystallographic defects. However, these techniques are not always effective and the reasons for this are currently not always well understood.
In this thesis, a correlative microscopy approach is developed, incorporating electron beam induced current (EBIC), electron back scatter diffraction (EBSD) and atom probe tomography (APT). This approach combines the characterisation of recombination activity, crystallographic information, and chemical composition of individual defects after various stages of processing. These methods were employed to determine the cause of contamination from room temperature colloidal silica polishing and also investigate the evolution of grain boundaries at various stages of gettering and hydrogenation. In addition, this approach was also applied to alternative PV materials of Red Zone HPMC-Si and n-type HMPC-Si, demonstrating wide-scale applicability.
Nitrogen was observed to correlate with an increase in recombination activity at certain grain boundaries. In addition, the light elements carbon and oxygen were also observed to decorate grain boundaries. No transition metals, except copper, were detected. This may be due to the detection limit of APT, which was calculated to be as high as 1015 cm-3 for Fe.
Furthermore, applying this new multiscale correlative microscopical approach to the analysis of deuterium (2H) passivated wafers, hydrogen has been directly observed to decorate crystallographic defects in silicon and the extent of segregation quantified. These new insights have the potential to directly address the question as to why some grain boundaries respond positively to hydrogenation, whereas others do not.
The politics of the Italian budgetary process
Keywords: Italy
politics
budgetary
budget
Italian

The thesis presents a descriptive analysis of Italian budgetary politics during the 1980s and 1990s. This work explores the institutional and political contexts of budgeting, and updates the literature on the Italian budgetary process. The dissertation identifies three periods of budgeting. The first period, from 1979 to 1992, was characterized by immobilism in budgetary politics. In this era, successive Italian governments failed to realize deficit containment policies. The 1992-94 period was marked by a transition in budgetary politics. In the sphere of budgeting, there were important changes to budget behaviour and budget outcomes. At the political level, a crisis in Italy’s political system gradually gave rise to a more adversarial party system. The post-1994 period witnessed more stable executive governance in budgetary politics.
During these years, Italian governments more successfully realized public finance objectives than did governments during the era of immobilism. This descriptive analysis of Italian budgeting highlights a number of key developments that took place over the course of the transition from immobilism to executive governance. These include growing treasury primacy in budget policy coordination, and the changing institutional and procedural circumstances governing parliamentary budgeting. Furthermore, the work presents two case studies to highlight these trends in Italian budgeting. The first is an examination of the politics of pension reform, and the second is a study of the politics of taxation.
Some models from mathematical population genetics with fluctuations in the environment
Keywords: Spatial Lambda Fleming-Viot model
stochastic growth model
Fluctuating selection
lookdown construction
Tracer dynamics
SuperBrownian motion
scaling limits

We are interested in populations in which the fitness of different genetic types fluctuates in time and space, driven by temporal and spatial fluctuations in the environment. For simplicity, our population is assumed to be composed of just two genetic types. Short bursts of selection acting in opposing directions drive to maintain both types at intermediate frequencies, while the fluctuations due to ‘genetic drift’ work to eliminate variation in the population. We consider first a population with no spatial structure, modelled by an adaptation of the Lambda (or generalised) Fleming-Viot process, and derive a stochastic differential equation as a scaling limit. This amounts to a limit result for a Lambda-Fleming-Viot process in a rapidly fluctuating random environment. We then extend to a population that is distributed across a spatial continuum, which we model through a modification of the spatial Lambda-Fleming-Viot process with selection. In this setting we show that the scaling limit is a stochastic partial differential equation. As is usual with spatially distributed populations, in dimensions greater than one, the ’genetic drift’ disappears in the scaling limit, but here we retain some stochasticity due to the fluctuations in the environment, resulting in a stochastic partial differential equation driven by a noise that is white in time but coloured in space. We discuss the (rather limited) situations under which there is a duality with a system of branching and annihilating particles. We also write down a system of equations that captures the frequency of descendants of particular subsets of the population and use this same idea of ‘tracers’, which we learned from Hallatschek and Nelson (2008) and Durrett and Fan (2016), in numerical experiments with a closely related model based on the classical Moran model. We also investigate the behaviour of an establishing mutation which is subject to rapidly fluctuating selection under the Lambda-Fleming-Viot model and show that under a suitable scaling it converges to the Feller diffusion in a random environment. We then extend to a population that is distributed across a spatial continuum. In this setting the scaling limit is the SuperBrownian motion in a random environment. The scaling results for the behaviour of the rare allele are achieved via particle representations which belong to the family of ‘lookdown constructions’.
The growth, regulation and environmental impact of green electricity tariffs
Keywords: green tariffs
green electricity tariffs
ethical consumption
retail electricity markets
sustainable consumption
green power
electricity market regulation

In many retail electricity markets consumers are able to choose to purchase a green tariff, where the kWh consumed are matched by their retailer with electricity generated from renewable sources. These tariffs are sold to consumers as a way to reduce their own carbon footprints and as a way to help fight climate change. This thesis asks "what is the role of green electricity tariffs in reducing carbon emissions?" The question is answered by exploring the growth, regulation and environmental impact of markets for voluntary green electricity tariffs through four related areas:
•Chapter four undertakes an international comparison of markets for green electricity tariffs. Variation in enrolment levels is measured, which is then explained in reference to macro level variables including the regulatory environment, market competition and the types of supplier operating.
•Chapter five looks at one mechanism to increase consumer engagement with retail electricity markets, digital third-party intermediaries, and explores potential tradeoffs with the ability for consumers to discover and switch to green electricity tariffs.
•Chapter six uses a consumer survey to explore attitudes towards the environmental benefit of green electricity products. A census of the ‘additionality’ contributions made by retailers is undertaken to analyse whether the products available on the market meet consumers’ expectations.
•Chapter seven outlines the causal mechanisms whereby consumer demand for green tariffs translates into lowered carbon emissions, using a mixed methods approach.
The research highlights the importance of understanding the retail market context of green electricity tariffs, as enrolment is found to be affected by levels of competition in the market. It is also possible that increased use of intermediaries may present a challenge for the future green tariff market growth. An assessment of the environmental benefit finds that the green tariffs available in the UK have a negligible impact on lowering carbon emissions, with consumer research also suggesting that the tariffs currently on the market are not meeting customers’ expectations.
Directing structure through chirality
Keywords: DNA nanotechnology
Cholesteric phases
Molecular modelling
Chirality
Self-assembly

Chirality - or the absence of mirror symmetry - is a fundamental physical property that permeates geometrical structures in nature, from the double-helical shape of DNA to the macroscopic anatomy of entire organisms. However, the specific mechanisms underpinning the propagation of chirality across such wide differences in length-scales often remain poorly understood. In this thesis, we explore the quantitative link between molecular and supramolecular chirality in liquid crystal phases of elongated polymers, which are ubiquitously observed in both biological and artificial colloidal solutions. We investigate the self-assembling behaviour of such systems through the combination of detailed numerical simulations and classical density functional theory in the Onsager formalism. The quantitative accuracy of the latter and of its various extensions is thoroughly assessed in the case of both rigid and flexible particle models, and rigorous first-principle derivations of its underlying mathematical framework are systematically provided. An original virial integration scheme based on hierarchical bounding volumes is also introduced to accelerate non-bonded interaction energy computations by several orders of magnitude for complex, highly-anisotropic molecular systems. These developments allow us to tackle the cholesteric assembly of DNA origamis using a structurally- and mechanically-realistic representation of the particles, and enable us to provide theoretical evidence of a novel mechanism of chirality amplification in liquid crystals, whereby phase chirality is governed by fluctuation-stabilised helical deformations in the conformations of their constituent molecules. Our results compare favourably to recent experimental measurements and demonstrate the influence of intra-molecular mechanics on chiral supramolecular order, with potential implications for a broad class of experimentally-relevant colloidal systems.
Reading the Qur’an in light of the Manār
Keywords: Rashīd Riḍā

Muḥammad ῾Abduh (d. 1905) and Muḥammad Rashīd Riḍā’s (d. 1935) Tafsīr al-Manār is widely considered a turning point in Qur’anic exegesis for its presumed departure from traditional Sunni Arabic commentaries on the Qur’an, both methodologically and intellectually. This thesis investigates this assumption by taking a closer look at the text of the Manār commentary itself. With a primary focus on the Tafsīr al-Manār’s exegesis of Sūrat al-Mā’ida—authorship of which should, along with most other parts of the commentary, be ascribed to Rashīd Riḍā—I argue that, although certain traditional exegetical techniques and features remain in this commentary, their presence and function appear to be superficial in many ways. Specifically, Rashīd Riḍā breaks with some of the conventions followed by classical mufassirūn not only by introducing a number of novel ideas, some of which stand in opposition to classical Sunni doctrine, but also by demonstrating a much more pronounced interest in the social and political realities of his day. In this context, the author often seems to use tradition in a way that serves the purpose of advancing his own agenda as a social reformer, although he does so in an arguably subtle and nuanced fashion. On the one hand, abiding by certain traditional exegetical rules allows him to showcase his own scholarly credentials to participate in the long-standing tafsīr genre. On the other hand, his proximity to and engagement with tradition seems to help him justify some of his more blatant departures in a manner that signals to the reader that his views are, in fact, not far-fetched at all, but intrinsically Islamic.
The chemistry of ynamides and yndiamides
Keywords: Ynamides
Nitrogen
Alkynes
Yndiamides
Copper Catalysis
Heterocycles

There have been significant developments in both the synthesis and applications of nitrogen-substituted alkynes since the turn of the millennium, but there is still much that remains unexplored. In continuing these developments, two projects have been completed:
(i) A general copper-catalysed synthesis of ynamides from 1,2-dichloroenamides was achieved with broad substrate scope. This includes the use of acyclic secondary amides, acyclic ureas and sterically hindered enamide partners.
(ii) The first known synthesis of yndiamides was developed, which involves the copper-catalysed coupling of 1,1-dibromoenamides with sulfonamides and phosphoramidates. A preliminary study of yndiamide reactivity in transition metal- and Brønsted acid-catalysed processes was also performed.
Combined with the aid of crystallographic, spectroscopic and computational analyses, more fundamental aspects of these compounds have been uncovered during these studies, including conformational preferences. Questions were also raised as to how these preferences can affect the reactivity and stability of ynamides and yndiamides.
Elucidating the structures of cationic metal-nitrous oxide complexes using infrared action spectroscopy
Keywords: Quantum Chemical Calculations
Photodissociation
Cluster Chemistry
Nitrous Oxide
Physical Chemistry
Infrared Spectroscopy
Metal-Ligand Complex

Gas-phase metal ion-molecule complexes provide model environments within which to study fundamental molecular interactions involved in ligand activation and metal ion solvation. These complexes also represent entrance-channel species for catalytic reactions. The ligand of interest in this thesis is nitrous oxide, which accounts for 5% of anthropogenic emissions and is a potent greenhouse gas with a warming potential 300 times greater than carbon dioxide. Thus, there is considerable interest in reducing N2O emissions particularly via metal-catalysed N2O reduction. M+/0/-(N2O)n complexes represent entrance-channel species for such reactions and yet, little attention has been given to the structures of M+/0/-(N2O)n complexes. This thesis presents the first experimental investigation on M+$(N2O)n and M+n(N2O) complexes studied via infrared action spectroscopy. The infrared spectra are further interpreted and assigned from simulated spectra based on density functional theory (DFT). A range of M+(N2O)n complexes (M = group 11, group 9, and Li, Al) have been studied in an attempt to draw comparisons between the different M+ electron configurations d10, d8, and closed s-shell, respectively). Spectroscopic signatures for N- and O-bound N2O ligands are observed in all cases however the importance of low-lying electronic states is revealed for the group 9 cations, and insertion complexes inferred for the Li+ ion.
Infrared multi-photon dissociation (IRMPD) studies on M+n(N2O) complexes (M = Au, Co) also present N- and O-bound spectroscopic signatures. However, as the metal cluster size increases, N2O binds preferentially via the terminal N-atom. Larger clusters represent a more effective energy "bath" facilitating annealing to the lowest energy structure.
Learning the structure of object categories from incomplete supervision
Keywords: ai
feature learning
machine learning
3d reconstruction
Computer vision

This thesis aims at learning and predicting the fine-grained structure of visual object categories given input image data. Alleviating the common requirement of collecting an ample amount of manual annotations, we propose several approaches that learn given an incomplete supervisory signal.
Specifically, we begin with an analysis of the amount of supervision needed to learn all visual variations of an object part. Motivated by the gathered observations, a detector of semantic (i.e. nameable) parts supervised with inexpensive web image search data is then proposed. The main challenge of handling a significant amount of annotation noise is addressed with a novel geometry-appearance embedding.
Moving away from semantic part detection, learning generic mid-level elements for understanding the geometry of object categories is brought into focus. A novel architecture that outputs a visual representation suitable for establishing image-to-image semantic correspondences is proposed. The main contribution consists of a new discriminability diversity objective that facilitates learning of sparse image features sensitive to the changes of the geometry of the input.
A similar feature learning machine leveraging the equivariance constraint is later introduced. Differently from existing alternatives, we adapt the method for the noisy settings of the training dataset by means of a novel probabilistic introspection framework. This allows for a selective representation of image pixels that have the potential to result in a correct match.
Inspired by the ability of deep networks to decompose an object into a constellation of pixel-perfect landmarks, an opposite problem of grouping image pixels belonging to an object is addressed. More specifically, we deal with the instance segmentation problem using a deep convolutional architecture that "colors" image pixels with their instance labels. Identifying the convolutional coloring dilemma, a drawback of standard position-agnostic networks that prevents them from solving this task, we propose a correction comprising a novel position-sensitive semi-convolutional operator.
The last tackled task is learning 3D shapes of object categories. Inspired by the human visual system, a deep network that learns by observing an object category in a sequence of videos is described.
Our final contribution is a probabilistic learning scheme that increases robustness of network training and enables test-time confidence predictions. This is achieved by explicitly modeling the distribution of training errors caused by the insufficiencies of the model or by the noise in ground truth annotations.
Frequency metrology at the 10^−18 level with an ytterbium ion optical clock
Keywords: optical clock
atomic clock
frequency
time
metrology
atomic physics
ytterbium

Atomic clocks, the most accurate instruments in existence, are reaching new levels of precision. These devices now find novel uses—from the exploration of relativity [1] to the detection of dark matter [2, 3]—all from same principle: measurement of the frequency of the light that excites a reference atomic transition. The 2S1/2 (F 0) → 2F7/2 (F 3) electric octupole (E3) transition in 171Yb+, with its Δν ≈ 1 nHz [4] linewidth and low sensitivity to external electromagnetic fields, lends itself to this usage [5].
We probe this transition in a single 171Yb+ ion held in a newly-designed endcap RF trap [6]. This design achieves a low temperature rise of 0.14(14)K. Excess micromotion in the trap is automatically compensated, resulting in a fractional frequency uncertainty of the combined RF-Stark and 2nd order Doppler shifts of 3.6 × 10−19. Anomalous phonon heating rates in the radial plane were measured as (−4.9 ± 5.2) s−1 and (−1.3 ± 3.6) s−1 for secular frequencies of 446 kHz and 470 kHz.
The ion’s differential polarisability at λ = 7 μm has been measured, suggesting a reduction in the BBR-related systematic error of the electric quadrupole (E2) transition by a factor of 5 and confirming the results of a previous measurement for the E3, performed using a different method [7]. However, a limitation prevented full confidence in our uncertainty levels.
To pre-stabilize the frequency of our laser a 28 cm long, ultra-stable Fabry-Pérot cavity was constructed and used to drive the E3 atomic resonance with a linewidth of 1.64(2) Hz. Its finesse was measured as 458 000 and, in an atomic lock, a clock stability of 1.9 × 10−15 (τ/1 s)−1/2 was observed. The laser’s frequency was measured and its stability transferred to other wavelengths via a femtosecond optical frequency comb.
An international clock comparison campaign was carried out via satellite-mediated microwave links: the first of its scale, involving 4 National Measurement Institutes (NMIs) and 5 optical atomic clocks. A new technique was developed to analyse the resulting data and to characterize its uncertainty. The lowest fractional uncertainty in the comparison between any pair of clocks was 2.8 × 10−16.
Finally, an absolute measurement of the E3 transition has been carried out through a link to International Atomic Time (TAI), without a local primary standard. The transition frequency was measured to be 642 121 496 772 645.17(22) Hz: the best measurement of this transition to date [8, 9].