VictorJuiz/thesis huggingface dataset:
Insect metapopulation dynamics
Keywords: population dynamics
dispersal
population modelling
metapopulation
spatial ecology
Bruchid
landscape

Metapopulation ecology has developed to explain the population dynamics that occur in spatially structured landscapes. In this study, I combined an empirical laboratory approach, using metapopulation microcosms of Callosobruchus maculatus and its endospecific parasitoid Anisopteromalus calandrae, with mathematical population models in order to investigate several fundamental metapopulation processes.
Population dynamics in these systems can be studied at two scales; the local patch-wise scale and the regional metapopulation scale. Here I demonstrate that in both homogeneous and heterogeneous landscapes knowledge of local scale demographic processes is necessary in order to understand regional metapopulation dynamics. The differences in the rate and net direction of dispersal between patches as a result of the permeability of the matrix in homogeneous systems and density-dependent dispersal in heterogeneous systems were also explored.
Metapopulation dynamics rely on a balance between local extinctions and recolonisations. Therefore, increasing local mortality rates is likely to be detrimental to the persistence of the system. Here, the impact of several common harvesting strategies on the persistence of a host-parasitoid metapopulation was examined. Contrary to expectation I discovered that harvesting in these systems increased both local and regional population sizes. The increased population size as a result of increased mortality was explained in terms of a hydra effect, where harvesting relaxed density-dependence acting on local host populations.
The results presented in this thesis are relevant for the monitoring, management and conservation of natural metapopulations and the development of sustainable harvesting strategies in structured landscapes.
Age at menarche and menopause: their correlates and association with selected cardiovascular disease risk factors among 300 000 Chinese women in the China Kadoorie Biobank
Keywords: cardiovascular disease
Kadoorie Biobank
China
menopause
menarche

Background: Age-standardised mortality rates for cardiovascular disease (CVD) are generally higher among men than women, prompting suggestions that reproductive factors may be partly responsible. Moreover, there have been major changes in women’s reproductive patterns and CVD rates in China over the last few decades, but the association between them is still poorly understood.
Objectives: To start addressing these issues, this thesis examines the secular trends and correlates of age at menarche and menopause (the major physiological events defining a woman’s reproductive window), as well as their association with blood pressure and anthropometry in 302 180 women born in 1930-74 from 10 areas across China using cross-sectional demographic, behavioural, physical and reproductive data from the China Kadoorie Biobank.
Results: Mean age at menarche decreased by 2 years over a 44-year period (1930-1974), with the exception of an increase of about 1 year for women exposed to the Great Chinese Famine in early adolescence. No other factor showed as large an effect on age at menarche. Among women aged >57 years at the baseline, mean age at menopause increased by 1.4 years over a 21-year period (1930-1951) and was significantly associated with several reproductive and behavioural factors, notably gravidity (2 years later menopause) and smoking (6 months earlier menopause). Blood pressure and anthropometry were weakly inversely associated with age at menarche (0.2mmHg and 0.2kg/m² lower per year later menarche) and even more weakly positively associated with age at menopause (0.06mmHg and 0.04kg/m² higher per year later menopause). These trends and associations all varied to some extent by area and socioeconomic status. (All p-values <0.0001)
Conclusion: This study adds new information on the secular trends and correlates of age at menarche and menopause in a large Chinese population born around the mid-20th century and provides a basis for further prospective work on the association of reproductive history with the incidence of CVD in China.
On large gaps between consecutive zeros, on the critical line, of some zeta-functions
Keywords: Zeta and L-functions
analytic theory

In this thesis we extend a method of Hall
[
30
,
34
]
which he used to show the existence of large gaps between consecutive zeros, on the critical line, of the Riemann zeta-function
z
e
t
a
(
s
)
. Our modification involves introducing an "amplifier" and enables us to show the existence of gaps between consecutive zeros, on the critical line at height
T
,
of
z
e
t
a
(
s
)
of length at least
2.766
x
(
2
p
i
/
l
o
g
T
)
. To handle some integral-calculations, we use the article
[
44
]
by Hughes and Young.
Also, we show that Hall's strategy can be applied not only to
z
e
t
a
(
s
)
,
but also to Dirichlet
L
-functions
L
(
s
,
c
h
i
)
,
where
c
h
i
is a primitive Dirichlet character. This also enables us to use stronger integral-results, the article
[
14
]
by Conrey, Iwaniec and Soundararajan is used. An unconditional result here about large gaps between consecutive zeros, on the critical line, of some Dirichlet
L
-functions
L
(
s
,
c
h
i
)
,
with
c
h
i
being an even primitive Dirichlet character, is found. However, we will need to use the Generalised Riemann Hypothesis to make sense of the average gap-length between such zeros. Then the gaps, whose existence we show, have a length of at least
3.54
times the average.
Coarse-grained modelling of nucleic acids
Keywords: DNA
Coarse-grained modelling
Nanotechnology
RNA

This thesis considers coarse-grained models of DNA and RNA, developed in particular to study nanotechnological applications as well as some important biophysical processes. We first introduce sequence-dependent thermodynamics into a previously developed coarse-grained rigid base-pair model of DNA. This model is then used to study sequence-dependent effects in multiple DNA systems including: the heterogeneous stacking transition of single strands, the fraying of a duplex, the effects of stacking strength in the loop on the melting temperature of hairpins, the force-extension curve of single strands, and the structure of a kissing-loop complex. We further apply the DNA model to study in detail the properties of an autonomous unidirectionally propagating DNA nanotechnological device, called the burnt bridges motor''. We then apply the coarse-graining methods developed for the DNA model to construct a new sequence-dependent coarse-grained model of RNA, which aims to capture basic thermodynamic, structural and mechanical properties of RNA molecules. We test the model by studying its thermodynamics for a variety of secondary structure motifs and also consider the force-extension properties of an RNA duplex. This RNA model allows for efficient simulations of a variety of RNA systems up to hundreds or even thousands of base-pairs. Its versatility is further demonstrated by studying the thermodynamics of a pseudoknot folding, the formation of a kissing loop complex, the structure of a hexagonal RNA nanoring, and the unzipping of a hairpin.
The clustering of dusty star-forming galaxies: Connecting CMB cosmology and galaxy evolution
Keywords: Cosmology
Galaxies
Cosmic Microwave Background
Astrophysics

In this thesis I construct various models to interpret measurements of the clustering of dusty star-forming galaxies through the angular power spectrum statistic. The goals of this work are, firstly, to facilitate the separation of the dusty galaxy contribution from the cosmic microwave background background (CMB) power spectrum, and, secondly, to improve our understanding of the physical properties of these galaxies. I present analysis of the first cross-correlation of millimeter and submillimeter sky maps, using data from the Atacama Cosmology Telescope (ACT) and the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST), which revealed that the dusty galaxies that dominate the submillimeter sky are, to a significant extent, those same sources that are a nuisance contaminant for CMB cosmology. I then perform a joint fit to the ACT and BLAST power spectra as well as early results from the Planck Surveyor to construct a simple phenomenological template for the frequency and angular scale dependence of the contribution from clustered dusty galaxies to the total power spectrum. This template may be used to assist in extracting the CMB signal from future ACT and other data sets. The correlation between dusty galaxies and the thermal Sunyaev Zel'dovich effect leads to an additional contribution to the measured angular power spectrum that further hampers constraining quantities of cosmological interest. I present the first physically-motivated model for this correlation, and make predictions for its frequency and scale dependence as a CMB foreground. Finally, I combine angular power spectrum measurements from ACT, Planck and other instruments with deep far-infrared and submillimeter source number counts and constrain a model for the emission properties of these dusty galaxies. I demonstrate that the power spectrum carries significant constraining power and can improve our understanding of dust emission and star formation from unresolved objects at high redshift.
An intra-pulse fast feedback system for a future linear collider
Keywords: hep
nlc
fast
ilc
ipfb
feedback
accelerators
font

An intra-pulse Interaction Point fast feedback system (IPFB) has been designed for the Next Linear Collider (NLC), to correct relative beam-beam misalignments at the Interaction Point (IP). This system will utilise the large beam-beam kick that results from the beam-beam interaction and apply a rapid correction to the beam misalignment at the IP within a single bunch train. A detailed examination of the IPFB system is given, including a discussion of the necessary electronics, and the results of extensive simulations based on the IPFB concept for fast beam correction are presented. A recovery of the nominal luminosity of the NLC is predicted well within the NLC bunch train of 266 ns.
The FONT experiment - Feedback On Nanosecond Timescales - was proposed as a direct test of the IPFB concept and was realised at the NLC Test Accelerator at SLAC. As part of FONT, a novel X-band BPM was designed and tested at the NLCTA. The results of these tests with the NLCTA short and long-pulse beam are presented, demonstrating a linear response to the position of the 180 ns long-pulse beam: measurements show a time constant of ~1.5 ns and a precision of better than 20 microns. A novel BPM processor for use at X-band, making use of the difference-over-sum processing technique, is also presented in detail, with results given for both short and long-pulse beams.
The FONT design concepts and modification of the IPFB system for use at the NLCTA are described. The design of a fast charge normalisation circuit, to process the difference and sum signals produced by the BPM processor, forming part of the FONT feedback circuit, is detailed extensively. Bench tests of the feedback electronics demonstrate the effectiveness of the normalisation and feedback stages, for which a signal latency of 11 ns was measured. These bench tests also show the correct operation of the normalisation and feedback principles. Finally, the results of a full beam test of the FONT system are presented, during which a system latency of 70 ns was measured. These rigorous tests establish the soundness of the IPFB scheme and show correction of a mis-steered bunch train within the full NLCTA pulse length of 180 ns.
Responsibilities for the global health crisis
Keywords: Global Justice
Access to Medicine
Rights and Responsibilities
Right to Health
Pharmaceutical Transnational Corporations

This thesis aims to provide a framework for analyzing the moral responsibilities of global agents in what I call the Global Health Crisis (GHC), with special attention devoted to the moral responsibilities of pharmaceutical companies. The main contribution of this thesis is to provide a general account of the moral responsibilities of different global players, mapping the different kinds of duties they have, their content and force, and their relation to the responsibilities of other relevant actors in the GHC. I also apply this account to current debates surrounding the need for reforms to the international legal rules addressing the GHC, notably the TRIPs regime. In doing so, this thesis will discuss the allocation of responsibilities for the GHC among different global players, such as state and non-state actors, the latter including pharmaceutical companies. In order to investigate the allocation of duties, I will first analyze the object of such allocation which constitutes the object of the current GHC (Part A); then the agents responsible for addressing this crisis (Part B); and finally, existing institutional alternatives to reform the international legal rules addressing the GHC, such as the TRIPs regime (Part C).
Muslim Chaplaincy on campus: case studies of two American universities
Keywords: Islam
higher education
Muslim Chaplain

This thesis investigates the emergence and development of Muslim Chaplaincy at Princeton and Rutgers universities. It seeks to answer three questions: (1) How did university-based Muslim Chaplaincy develop? (2) What roles did Muslim Chaplains play? and (3) Why did university administrators hire and sanction Muslim Chaplains? The thesis explores these questions by examining the decision making processes of administrators through in-depth case studies based on observations, document analysis, and 64 interviews with current and former Muslim Chaplains, University Chaplains, Muslim student leaders, faculty members, alumni, and other administrators. The case studies are prefaced by a description of the national context for campus Muslim Chaplaincy based on 36 interviews with religious life professionals at 21 other colleges.
My research suggests that Muslim Chaplaincy at Princeton emerged through the advocacy of Christian University Chaplains; in contrast, at Rutgers the role was created by a local community organisation and sanctioned by student affairs professionals. Campus Muslim Chaplains played a variety of roles. For Muslim students, they provided religious, pastoral, advisory, educational, programmatic, and liaisonal support. They also served other university constituents and local community members. Administrators at both institutions had multiple rationales for hiring and sanctioning Muslim Chaplains: to advance social justice for Muslim students, to provide an educational benefit to non-Muslim students, to remain competitive with peer institutions, to overcome histories of exclusion, and to avoid potential crisis situations.
The goal of this study is to make two contributions to knowledge. In terms of its subject, this thesis provides the first empirical case studies of Muslim Chaplaincy in American higher education and frames these cases within the national context. In terms of theory, this study aims to develop an understanding of the administrative rationales behind the creation of Muslim Chaplaincies. It does this through the application of the political, cultural, and adaptive sociological models of the university. In particular, it draws on the concepts of institutional isomorphism and risk mitigation/management as explanations for the emergence of Muslim Chaplaincy.
Bede's temple: an image and its interpretation
Keywords: medieval theology
Bede
Jewish temple
Anglo-Saxon
biblical Interpretation

This thesis studies, for the first time, Bede’s use of the image of the Jewish temple across all his writings. Not only analysing how Bede developed earlier Christian interpretations of the temple, it also uses the temple-image to shine light on under-explored aspects of his theological thought. Throughout, I argue that the communal understanding of the temple-image in Bede’s monastery helped shape his exegesis; we should think of Bede, not as an individual scholar, but as a monk engaged in an active discourse concerning the Bible.
Chapter 1 introduces the thesis, providing the historiographical and historical context. Bede’s exegesis existed within a long tradition of Christian interpretation of the temple, as Chapter 2 shows; one image could be interpreted in diverse ways by Bede and therefore this thesis follows a thematic approach. Chapter 3 studies Bede’s engagement with the cosmic interpretation of the temple, in particular his use of the image to emphasise the Anglo-Saxons’ participation in the universal Church. Analysing Bede’s interpretation of the Jewish priesthood, Chapter 4 argues that he championed an élite of ordained clerics in the role of reforming the temple-Church. This Church clashed with the Body of Satan, symbolised by the Tower of Babel, concerning which the contemporary Northumbrian situation shaped Bede’s understanding. For Bede, the temple-image stressed Christ’s humanity and his sacrificial priesthood, as Chapter 5 shows. Bede urged the faithful to shape themselves as pure temples in imitation of Christ, directing them towards union with God. A diachronic overview of Bede’s writings on the temple in Chapter 6 highlights the importance of the years immediately prior to 716, the period in which the Codex Amiatinus was created at his monastery of Wearmouth-Jarrow, in the development of Bede’s interpretation of the temple. We should consider the possibility that Bede’s temple-commentaries drew upon interpretations formed in this communal, monastic, context.
Numerical modelling of environmental dose rate and its application to trapped-charge dating
Keywords: trapped-charge luminescence dating
beta
gamma
MCNP
doserate
PENELOPE
Monte Carlo
dose
alpha
radiation

Accurate estimation of environmental dose rate is essential for high-resolution trapped-charge dating. Beta and gamma emissions from simulated sediments containing radioactive uranium, thorium and potassium are modelled in contexts that are spatially heterogeneous. Dose rate was modelled using Monte Carlo radiation transport codes MCNP and PENELOPE. A number of key issues that affect dose rate evaluation are examined and updated corrections are calculated.
Granular structures used for geometrical input into the models were simulated using randomly packed ellipsoids. The pair correlation function and chord length distributions were derived. The effects of water content on dose rate were modelled and compared with cavity theory. Apart from activity dilution, the variation of grain size or water content was shown to be significant for gamma radiations due to the transition from charged particle equilibrium. The standard correction for beta dose rate due to grain size was found to be satisfactory although sensitivity to grain shape and material should be taken into account.
Dose rate modeling was applied to three dating studies of early human fossils: Skhul V, Israel skull; Hofmeyr, South Africa skull and the Forbes’ Quarry, Gibraltar skull. The spatial modelling was implemented using computerised tomographic (CT) images and dose rate found to be modified significantly by the presence of the skull in the sediment. Time evolution of the dose rate was examined for the latter two skulls and dates of 36±3ka (Hofmeyr) and 55-95ka (Forbes’ Quarry) were calculated.
Altered hippocampal fast oscillations and GABAergic circuits in neuregulin 1 over-expressing mice
Keywords: interneurons
hippocampus
schizophrenia
network oscillations
parvalbumin

Neuregulin 1 (NRG1) is a growth factor implicated in neurodevelopment and postnatal maintenance of synaptic circuits. Its gene has been associated with schizophrenia, and the expression of the type I isoform (NRG1tyI) is increased in patients’ brains. Earlier behavioural phenotyping of mice over-expressing NRG1tyI revealed impairment in hippocampus-dependent spatial working memory. This present work investigates the effects of increased NRG1tyI expression on hippocampal network functioning in these mice.
Fast network oscillations, specifically at gamma frequencies, were studied in CA3 hippocampal slices in a carbachol model using cellular and extracellular microelectrode recording techniques. The peak frequency of field potential oscillations was significantly reduced in slices from NRG1tyI mice compared to wild-type littermates. In addition, NRG1tyI mouse slices were more prone to develop epileptiform activity. During rhythmic activity, the balance of phasic excitation and inhibition was significantly altered in principal cells of NRG1tyI mice. Inhibitory synaptic input was more sustained, while excitatory synaptic currents were kinetically unchanged but larger and more variable in amplitude. Together, these data suggest altered functioning of the GABAergic inhibitory circuits that generate and maintain gamma oscillations. Because parvalbumin-expressing (PV+) interneurons are a major target of NRG1 signalling, the inhibition from PV+ interneurons to pyramidal cells was examined next. Channelrhodopsin-2-mediated photostimulation of PV+ cell axons failed to show changes in GABAergic inhibition of CA3 pyramidal cells in NRG1tyI mice. However, synaptic miniature glutamatergic neurotransmission was reduced in identified PV+ basket cells (BCs) and axo-axonic cells (AACs) but not in pyramidal cells. The change was expressed postsynaptically, affecting NMDA receptor- but not AMPA receptor-mediated currents.
The data suggest that NRG1tyI over-expression results in alterations in PV+ interneuron types, particularly at the glutamatergic synapses that excite these cells. These changes and the altered gamma oscillations are already evident in late adolescence — before the age at which cognitive deficits are detectable.