VictorJuiz/thesis huggingface dataset:
The dynamics of social assistance benefit receipt
Keywords: Benefit Dynamics
Minimum-Income Benefits
Welfare Benefits
State Dependence
Social Assistance Benefits

This dissertation consists of three articles on social assistance benefit receipt dynamics in European countries.
The first article presents an analysis of state dependence in benefit receipt in Germany based on annual survey data from the German Socio-Economic Panel. The observation period extends from 1995 to 2011, thus covering the 2005 'Hartz reforms'. I estimate a series of dynamic random-effects probit models to control for observed and unobserved heterogeneity and the endogeneity of initial conditions. The high observed state dependence has a substantial structural component, with benefit receipt one year ago being associated with an increase in the likelihood of receipt today by 13 percentage points. There is only little evidence for time-variation in state dependence.
The second article presents evidence on spell durations and the frequency of repeat spells using monthly administrative data from Luxembourg, the Netherlands, Norway and Sweden. In the two Nordic countries, short-term benefit receipt is the norm, with only around 6% and 11% of spells in Norway and Sweden lasting longer than 12 months. Most recipients however have multiple spells. In Luxembourg and the Netherlands, long-term benefit receipt is frequent, with median spell durations of 14 and 9 months, respectively, and one-third and one-quarter of all spells lasting 24 months or longer. The total duration of benefit receipt across spells is much higher in the Netherlands and Luxembourg than in Norway and Sweden.
The third article tests the validity of one of the central assumptions of dynamic discrete-choice models of benefit dynamics, the conditional Markov property. Using monthly administrative data from Norway, the article shows that the Markov property is violated as estimated state dependence is affected by the chosen time unit of analysis. The standard model can be improved by permitting for different entry and persistence equations and duration and occurrence dependence in benefit receipt.
The complexity of graph polynomials
Keywords: Tutte polynomial
Vassiliev invariant
knot polynomial
simplicial complex
polymatroid
computational complexity
knot graphs
graph polynomial
graphs of bounded tree-width
delta-wye graphs

This thesis examines graph polynomials and particularly their complexity. We give short proofs of two results from Gessel and Sagan (1996) which present new evaluations of the Tutte polynomial concerning orientations. A theorem of Massey et al (1997) gives an expression concerning the average size of a forest in a graph. We generalise this result to any simplicial complex. We answer a question posed by Kleinschmidt and Onn (1995) by showing that the language of partitionable simplicial complexes is in NP.
We prove the following result concerning the complexity of the Tutte polynomial:
Theorem 1. For any fixed k, there exists a polynomial time algorithm A, which will input any graph G, with tree-width at most k, and rational numbers x and y, and evaluate the Tutte polynomial, T(G;x,y).
The rank generating function S of a graphic 2-polymatroid was introduced by Oxley and Whittle (1993). It has many similarities to the Tutte polynomial and we prove the following results.
Theorem 2. Evaluating S at a fixed point (u,v) is #P-hard unless uv=1 when there is a polynomial time algorithm.
Theorem 3. For any fixed k, there exists a polynomial time algorithm A, which will input any graph G, with tree-width at most k, and rational numbers u and v, and evaluate S(G;u,v).
We consider a class of graphs S
, which are those graphs which are obtainable from a graph with no edges using the unsigned version of Reidemeister moves. We examine the relationship between this class and other similarly defined classes such as the delta-wye graphs. There remain many open questions such as whether S contains every graph. However we have an invariant of the moves, based on the Tutte polynomial, which allows us to determine from which graph with no edges, if any, a particular graph can be obtained.
Finally we consider a new polynomial on weighted graphs which is motivated by the study of weight systems on chord diagrams. We give three states model and a recipe theorem. An unweighted version of this polynomial is shown to contain as specialisations, a wide range of graph invariants, such as the Tutte polynomial, the polymatroid polynomial of Oxley and Whittle (1993) and the symmetric function generalisation of the chromatic polynomial introduced by Stanley (1995). We close with a discussion of complexity issues proving hardness results for very restricted classes of graphs.
Electromagnetically induced transparency and light storage in optically dense atomic vapour
Keywords: Rubidium
EIT
Electromagnetically induced transparency
Slow light
Light storage

This thesis set out to investigate light storage based on dynamic electromagnetically induced transparency (EIT) in a room-temperature atomic ensemble of rubidium as a means to provide a quantum memory for single-photons created by a single rubidium atom coupled to a high-finesse optical resonator.
Setting up the light storage medium presented a new addition to the research group's portfolio of experimental techniques and led to investigations of EIT, slow light and stored light in warm rubidium-87 vapour. Lambda level schemes connecting Zeeman or hyperfine substates on the D1 and D2 lines were addressed in rubidium vapour cells containing different buffer gases and different isotopic fractions of rubidium-87 and rubidium-85.
Single beam spectroscopy with a weak probe was used to characterise the vapour cells. A numerical method to fit the D line spectrum to a theoretical model to include isotopic fractions and collisional broadening of a buffer gas has been implemented. Temperature and isotopic fractions could be reliably extracted from the fit parameters.
For an offset-stabilisation of two lasers to address a lambda level scheme connecting the two different hyperfine groundstates in rubidium a phase locked loop including a frequency divider has been designed and implemented.
Light storage and retrieval has been demonstrated using a Zeeman scheme on the D1 line. Two microsecond long classical light pulses containing one million photons on average were stored and retrieved with an efficiency of 15% after a delay of one microsecond.
Several methods of attenuating the strong co-propagating control laser beam to allow for lowering the signal pulse intensity in future experiments are discussed.
Atomistic modelling of iron with magnetic analytic Bond-Order Potentials
Keywords: iron
interatomic potentials
magnetism
non-collinear magnetism
density functional theory
electronic structure
materials modelling
bond-order potentials
tight-binding

The development of interatomic potentials for magnetic transition metals, and particularly for iron, is difficult, yet it is also necessary for large-scale atomistic simulations of industrially important iron and steel alloys. The magnetism of iron is especially important as it is responsible for many of the element's unique physical properties -- its bcc ground state structure, its high-temperature phase transitions, and the mobility of its self-interstitial atom (SIA) defects. Yet an accurate description of itinerant magnetism within a real-space formalism is particularly challenging and existing interatomic potentials based on the Embedded Atom Method are suited only for studies of near-equilibrium ferritic iron, due to their restricted functional forms.
For this work, the magnetic analytic Bond-Order Potential (BOP) method has been implemented in full to test the convergence properties in both collinear and non-collinear magnetic iron. The known problems with negative densities of states (DOS) are addressed by assessing various possible definitions for the bandwidth and by including the damping factors adapted from the Kernel Polynomial Method. A 9-moment approximation is found to be sufficient to reproduce the major structural energy differences observed in Density Functional Theory (DFT) and Tight Binding (TB) reference calculations, as well as the volume dependence of the atomic magnetic moments. The Bain path connecting bcc and fcc structures and the formation energy of mono- and divacancies are also described well at this level of approximation. Other quantities such as the high-spin/low-spin transition in fcc iron, the bcc elastic constants and the SIA formation energies converge more slowly towards the TB reference data. The theory of non-collinear magnetism within analytic BOP is extended as required for a practical implementation. The spin-rotational behaviour of the energy is shown to converge more slowly than the collinear bulk energy differences, and there are specific problems at low angles of rotation where the magnitude of the magnetic moment depends sensitively on the detailed structure of the local DOS. Issues of charge transfer in relation to magnetic defects are discussed, as well as inadequacies in the underlying d-electron TB model.
Sharī‘a under the English legal system in British India: Awqāf (endowments) in the making of Anglo-Muhammadan law
Keywords: waqf (endowment)
English law
Islamic law
colonial India
Anglo-Muhammadan law

This study analyses the treatment of Islamic law (Fiqh) under the English legal system by looking into the developments in waqf law in British India. It has the dual objective of analysing the impact of the English legal system upon Islamic law, and determining the role of various actors in this process. It argues that waqf law was transformed in order to fit into the state structure. The colonial state used the techniques of translation, adjudication, legislation and teaching in order to transform Islamic law. Adjudication was preferred over legislative codification as a mode of governance and rule making because of its flexibility. The translation of classical Islamic legal texts, the Hidāya and certain parts of the Fatāwā al-‘Ālamgīriyya, relieved English judges of the need for a reliance on local legal advisors. However, Muslim lawyers, judges, legal commentators, and some religious scholars (‘ulamā’) simultaneously collaborated and negotiated with, and resisted colonial administrators in the process of legal transformation. As adjudication was a preferred mode of transformation, legal commentaries played a crucial role in legal developments. A majority of legal commentators were Muslims, such as Ameer Ali, Abdur Rahim and Faiz Tyabji. They used their legal treatises to resist any colonial intervention in Islamic law.
Although English educated Muslims replaced ‘ulamā’ as cultural intermediaries between the state and society, this did not eliminate the role of ‘ulamā’ as the custodians of Islamic law. They established closer links with society and issued fatāwā (legal opinions) on legal issues. Fatāwā were sought regarding every important aspect of waqf law, from the validity of family awqāf to the management of awqāf and the permissibility of awqāf of movables such as shares of companies. ‘Ulamā’ also lobbied for the enforcement of Islamic law in order to promote women’s rights of inheritance and to get a divorce. This study finds that Anglo-Muhammadan law was a product of interaction between various sections of Muslim society and colonial administrators. It reflected the socio-political context of colonial India and the process of negotiations between divergent interest holders. Despite replacing the traditional institutional structure, the overall legal system became more inclusive. It could interact with various stakeholders and represent them in the process of law making in order to respond to social change.
A search for massive top quark resonances with the ATLAS detector at the Large Hadron Collider
Keywords: top resonances
jet algorithms
top physics
beyond standard model
exotic physics
t(bar over t) resonances

This thesis presents a search for resonant production of top-antitop quark pairs in final states containing at least one electron or muon. A number of beyond the standard model (BSM) theories incorporate a specific role for the top quark, resulting in resonances that preferentially decay to t(bar over t) pairs. The data sample analysed corresponds to an integrated luminosity of 2.05 fb-1 recorded during 2011 using the ATLAS detector at the Large Hadron Collider. The proton-proton centre-of-mass energy was 7 TeV.
The search is tailored towards heavy resonances at the TeV-scale which therefore decay to top quarks with high transverse momentum. Large hadronic jets are used to reconstruct the energy carried by the hadrons and the substructure of these jets is studied in order to identify hadronically decaying top quarks. The reconstruction can therefore proceed even if the decay products of the top quark are highly collimated. This study represents the first use of jet substructure techniques in a search for t(bar over t) resonances using hadron-hadron collision data.
The invariant mass of the reconstructed t(bar over t) pair is used to test compatibility of the data with the standard model prediction. No evidence for t(bar over t) resonances is found. Upper limits are derived on the production cross-section times branching ratio for narrow and wide resonant states, at the 95 % credibility level. An upper limit of 0.61 (0.65) pb is set for a narrow (wide) resonance with a mass of 1 TeV. Two specific BSM models are excluded within certain mass ranges: the narrow leptophobic Z' boson with mass 600 - 1150 GeV and the wide Kaluza-Klein gluon with a mass below 1.5 TeV. These results represent a significant improvement on those of previous searches performed at the ATLAS experiment, which did not use jet substructure techniques.
In addition, the possibility of using jets which decrease in size as their transverse momentum increases is investigated using simulated data. The yield of events due to resonant t(bar over t) production increases by approximately 20 % compared to when using jets of fixed size. Furthermore, the resolution of the invariant mass of the reconstructed t(bar over t) pair is found to improve by almost one fifth. It is recommended that a calibration scheme be developed for these variable-sized jets, so that their potential to improve the sensitivity to t(bar over t) resonances can be investigated further.
Federalism, the state and the city: explaining urban policy institutions in the United States and in the European Union
Keywords: European Union
state theory
urban policy
comparative federalism
historical institutionalism
United States
urban regeneration

This thesis contributes to the growing EU-US literature by comparing and explaining the evolution of urban policy in these two federal systems. The thesis begins with a puzzle: after introducing two similar and equally short-lived regeneration schemes—Model Cities (MC) (1967) and URBAN (1994)—the US and the EU followed different paths: the former replaced MC with the durable Community Development Block Grant (CDBG) in 1974, while the latter ended urban policy by ‘mainstreaming’ URBAN in its regional policy in 2006. To solve the puzzle I formulate a two-part argument: first, I explain the similarities between MC and URBAN as resulting from three factors: a favourable political context, holistic urban policy ideas, and centre-periphery mistrust. I then explain subsequent trajectories by looking at the interplay of policy and politico-constitutional institutions. While both MC and URBAN were unable to ‘stick’ because of their inherent weaknesses, the result of their demise depended on the existence of a federal ‘city welfare’ state. In the US, the Housing and Urban Development Department (HUD) embodied this state, and channelled Nixon’s attacks on MC into the creation of the structurally stronger CDBG. In the EU, conversely, DG Regio could not provide a comparable anchor for urban policy: when URBAN was attacked by regions and cities, the DG just reverted to its ‘business as usual’ by mainstreaming the programme.
I test my argument with a macro-historical comparison of the two cases and four in-depth city studies—Arlington, VA and Baltimore, MD on the US side, and Bristol, UK and Pescara, Italy on the EU side—aimed at analysing micro-level institutional dynamics. In both parts of the study I use a wide range of sources: secondary and grey literature, statistical sources and, especially, archival material and elite interviews. At both levels of analysis the test confirms my argument.
The structural, metamorphic and magmatic evolution of the Greater Himalayan Sequence and Main Central Thrust, Eastern Nepal Himalaya
Keywords: geochronology
Main Central Thrust
himalaya
tectonics
Greater Himalayan Sequence

Field observations of the Greater Himalayan Sequence in Eastern Nepal demonstrate a ductile, highly strained package of metamorphic rocks that show extensive evidence of crustal anatexis throughout. These can be distinguished from the Lesser Himalayan sequence below by a distinct reduction in metamorphic grade, an inverted metamorphic sequence and a high strain zone corresponding to the Main Central Thrust. Metamorphic studies are combined with geochronology to demonstrate a protracted period of crustal melting followed by rapid decompression from 18.7 Ma to 15.6 Ma. A metamorphic decompression rate is quantified at c.2mm/yr during this period. This is interpreted to represent exhumation of the Greater Himalayan Sequence by a process of ductile, channelised flow from the mid-crust beneath Tibet. Below a prominent band of kyanite gneiss, previously used to locate the Main Central Thrust, but here mapped within the Greater Himalayan Sequence, partial melting is still exhibited. Here monazites are dated at 10.6 Ma. In the Lesser Himalaya below, allanites record a similar 10.1 Ma event. This implies that following channel flow during the mid-Miocene, the channel widened in the lower-Miocene to incorporate a greater structural thickness. Following these two periods of exhumation and ductile extrusion, separated in time and space, Fission Track studies indicate that much slower, erosion driven exhumation proceeded, at <1 mm/yr. This rate increases slightly in the Pliocene, most likely in response to Northern Hemisphere glaciation; no difference in exhumation is seen across the Greater Himalayan Sequence with respect to the different, earlier, phases of ductile channel flow related exhumation. These results demonstrate the episodic nature of channel flow in the Himalaya and reconcile arguments about the position of the MCT in Eastern Nepal.
An analysis of the S. cerevisiae RMI1 gene
Keywords: Rmi1

The Saccharomyces cerevisiae Rmi1 protein is a component of the highly conserved Sgs1-Top3-Rmi1 complex, which is required for the maintenance of genome stability. The rmi1Δ deletion mutant has proven difficult to study because it exhibits very poor growth, and rapidly accumulates second site suppressor mutations. Furthermore, deletion of the putative HJ resolvase genes, MUS81-MUS81 or SLX1-SLX4 in rmi1Δ mutants causes synthetic lethality. In order to study phenotypes caused by loss of functional Rmi1, and to explore the genetic interactions between RMI1 and the MUS81, MUS81, SLX1 and SLX4 genes, a temperature sensitive mutant of RMI1 was isolated, named rmi1-1. Similar to rmi1Δ deletion mutants, rmi1-1 cells are highly sensitive to the DNA damaging agent, MMS and the replication inhibitor, HU. In addition, rmi1-1 mutants accumulate replication-associated branched DNA structures, and arrest in G2/M after a transient exposure to MMS. These cells are proficient in DNA damage checkpoint activation. Deletion of SLX1, SLX4, MUS81 or MUS81 in the rmi1-1 strain causes synthetic lethality, which is associated with cell cycle defects. Following a transient exposure to MMS, rmi1-1 mutants accumulate homologous recombination intermediates. These intermediates are slowly resolved at the restrictive temperature, revealing a redundant resolution activity in the absence of functional Rmi1. This resolution depends upon Mus81-Mms4, but not on Slx1-Slx4 or Yen1. I propose that while the Sgs1-Top3-Rmi1 complex constitutes the main pathway for removal of homologous recombination intermediates following a perturbed S-phase, Mus81-Mms4 can act as a back up for resolution of these intermediates, which most likely represent double Holliday junctions. In this study, I also present screens for high copy suppressors of rmi1-1 phenotypes, and for novel Rmi1 interaction partners.
Firing of Hippocampal Neurogliaform cells induces suppression of synaptic inhibition
Keywords: Interneuron
Electrophysiology
Hippocampus

The hippocampus contains more than 21 types of inhibitory interneurons that express different proteins and innervate different sub-domains of pyramidal cells to regulate the spatiotemporal integration of excitatory postsynaptic potentials (EPSPs) and to define temporal windows for spiking. Neurogliaform cells (NGFCs), form synapses on the distal tufts of pyramidal cell apical dendrites alongside excitatory inputs from the entorhinal cortex. NGFCs express neuronal nitric oxide synthase (nNOS), are often synaptically coupled, and fire rhythmically during theta oscillations in vivo.
In this thesis, I describe a novel form of synaptic communication between these interneuron types, hereafter referred to as the firing induced suppression of inhibition (FSI). Specifically, I found that when a theta-associated activity patterns were evoked in NGFCs from rodent hippocampal slices, the cells exhibited a transient reduction in unitary IPSP amplitude. My data suggest that FSI requires the backpropagation of action potentials, calcium influx through L-type calcium channels, nNOS activity within the dendrites of interneurons, and the activation of NO-sensitive guanylyl cyclase (NOsGC) receptors that are present on presynaptic terminals. My results also demonstrate the physiological impact of this phenomenon by showing that when FSI occurs, the strength of incoming excitatory postsynaptic potentials onto NGFCs are transiently sharpened. Specifically, FSI indirectly increased the amplitude of EPSPs. Thus FSI may enhance spatial and temporal summation of excitatory inputs to NGFCs and regulate their inhibition of pyramidal cells.