48 research outputs found
Birth Intervals and Reproductive Intentions in Eastern Africa: Insights from Urban Fertility Transitions
No full textThis thesis examines the dynamics of fertility in Eastern Africa with a particular focus on urban women. Urbanisation has long been closely associated with demographic transition and the reproductive behaviour of urban women is thought to provide insights about the future fertility transition at the national level. A mixed methods approach is used to explore birth intervals, family building strategies and women‟s fertility intentions. The quantitative analysis uses Demographic and Health Survey data from Ethiopia, Kenya, Tanzania and Zimbabwe, while the qualitative analysis uses data from focus group discussions that I conducted in two informal settlements of Nairobi, Kenya.
The analysis of birth intervals uses survival analysis to calculate interval-duration-specific fertility rates, median birth intervals and parity progression ratios. These are used to make inferences about fertility decision-making at the population level. Birth intervals are long and lengthening in all four countries, particularly among women who have used contraception and women with higher levels of education. Large differences exist in birth interval lengths between rural and urban women, even when the results are disaggregated by contraceptive use and educational status. Generally, lengthening birth intervals are being driven by increasing birth postponement and birth spacing, with postponement dominating among women with very long birth intervals. In Ethiopia, there is some evidence of parity-specific family size limitation.
The focus group discussions were analysed using a thematic approach. Urban living, particularly in the informal settlements, is characterised by high levels of social uncertainty, especially among new immigrants from rural areas. This is an important influence on women‟s relationships, which are found to be highly unstable. Fertility intentions are found to be fluid and contingent upon a variety of different factors in women‟s lives. As a result, women‟s decisions about birth spacing and family size are less distinct than demographic theory often assumes.
In sum, this thesis contributes to the body of research suggesting that long birth intervals and postponement are both important features of the fertility transition in Sub-Saharan Africa. These phenomenon are related to each other: social uncertainty leads to fluid fertility intentions, which, in turn cause the widespread postponement of births and lengthening birth intervals
Organocatalytic Asymmetric Synthesis of SynVesT-1, a PET Imaging Agent of the SV2A Receptor
No full text[18F]SynVesT-1 is a potent and selective positron emission tomography imaging agent for synaptic vesicle glycoprotein 2 (SV2A).1 SV2A is an integral transmembrane glycoprotein widely expressed in the brain. Although the exact role of SV2A has not been confirmed, it is known that SV2A participates in key vesicular processes. Furthermore, SV2A is a validated target for epilepsy and a biomarker of synaptic density.2 The established synthetic strategy to obtain [18F]SynVesT-1 involves the multistep synthesis of a racemic intermediate, requiring late-stage separation of the two enantiomers via chiral HPLC.3 Our aim was to develop an asymmetric synthetic route to access [18F]SynVesT-1.
In this work, we optimised a seven-step route to an organotin precursor of [18F]SynVesT-1 starting with a Wittig reaction of 3-bromo-5-fluorobenzaldehyde.4 This was followed by the asymmetric conjugate addition of nitromethane to the resulting cinnamaldehyde utilising the Hayashi-Jørgensen organocatalyst (Scheme 1). Subsequently, a number of standard transformations facilitated the synthesis of the organotin precursor which was then subjected to automated copper(II)-mediated fluoro-destannylation for the preparation of [18F]SynVesT-1. This work will be discussed, along with a second-generation route detailing the synthesis of a boronic ester-derived precursor to [18F]SynVesT-1.
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Synthesis and Photophysical Properties of Benzotriazole-Derived Unnatural α‑Amino Acids
No full textThe
synthesis of a new class of benzotriazole-derived α-amino
acid is described using a highly efficient nucleophilic aromatic substitution
of ortho-fluoronitrobenzenes with l-3-aminoalanine
and a polymer-supported nitrite reagent-mediated diazotization and
cyclization of the subsequent 1,2-aryldiamines as the key steps. Further
functionalization of the benzotriazole unit by preparation of halogenated
analogues and Suzuki–Miyaura cross-coupling with aryl boronic
acids allowed the synthesis of α-amino acids with conjugated
side chains. Analysis of the photophysical properties of these α-amino
acids revealed that incorporation of electron-rich substituents results
in charge-transfer-based, fluorescent compounds with MegaStokes shifts
Organocatalytic asymmetric synthesis of SynVesT-1, A synaptic density positron emission tomography imaging agent
No full textHeterocyclic nonacetamide ligands are used as positron emission tomography (PET) imaging agents of the synaptic vesicle glycoprotein 2A (SV2A), with potential applications in the diagnosis of various neuropsychiatric diseases. To date, the main synthetic strategy to access these optically active compounds has involved the racemic synthesis of a late-stage intermediate followed by the separation of the enantiomers. Here, we describe the use of iminium organocatalysis for the asymmetric synthesis of SynVesT-1, an important PET imaging agent of SV2A. The key step involved the conjugate addition of nitromethane with a cinnamaldehyde in the presence of the Jørgensen–Hayashi catalyst using the Merck dual acid cocatalyst system. Pinnick-type oxidation and esterification of the adduct was then followed by chemoselective nitro group reduction and cyclization using nickel borate. N-Alkylation of the resulting lactam then completed the seven-step synthesis of SynVesT-1. This approach was amenable for the synthesis of an organotin analogue, which following copper(II)-mediated fluoro-destannylation allowed rapid access to [18F]SynVesT-1
Bland-Altman plots assessing agreement between 2T model and Logan graphical analysis in all tissues with different input functions methods.
No full textGroup 1 (Logan) and Group 1 (2T) (a); Group 1 (Logan) and Group 2 (Logan) (b); and Group 1 (Logan) and Group 3 (Logan) (c). This was also carried out using only brain regions for Group 1 (Logan) and Group 1 (2T) (d); Group 1 (Logan) and Group 2 (Logan) (e); and Group 1 (Logan) and Group 3 (Logan) (f).</p
The Beginning and Before: Interpreting Creation in Paul and Philo
No full textGod’s creative activity in the beginning is important to Paul. Yet Paul’s care for and interpretation of it is often unrecognized, occasionally denied, typically left underdeveloped, and sometimes interpreted wrongly. This thesis approaches Paul as an interpreter of his sacred scriptural texts concerning creation. It compares his reading of creation in 1 and 2 Corinthians and Romans with those more detailed treatments of the same texts by Philo of Alexandria in his commentary on Genesis 1-2, De Opificio Mundi. The central thesis is this: Paul’s interpretation of creation, like Philo’s in his commentary, contains three interwoven aspects: the beginning of the world, the beginning of humanity, and God’s intentions before the beginning. Chapter 1, “Before the Beginning?,” explores Philo’s view that God’s pre-creational plan involves an architectural blueprint of the universe which enables goodness and beauty and Paul’s view that it involves a crucified Christ and a glory to which God-lovers are redeemed through conformity with this Christ’s image. There we will demonstrate that for Paul, as for Philo, the Before both affects and is affected by his reading of Genesis’ creation texts. Chapter 2, “The Beginning of the World,” establishes how Philo and Paul consider the ontological nature of heaven, earth, and their inhabitants to be beautiful and glorious due to perfect accord with God’s word, intentions, and desires—i.e., an implicit Before. Chapter 3, “The Beginning of Humanity,” investigates how Philo and Paul set the more particular creation of humanity within the larger context of the creation of the world, and how recognizing this aids in our own interpretation of some often misunderstood aspects of their views of Adam. God’s pre-creational “purpose” and “desire” is also an integral aspect of both interpreters’ treatments of the creation of humanity. Paul, like Philo, displays three tightly woven strands within his interpretation of the Beginning
[18F]LW223 has low non-displaceable binding in murine brain, enabling high sensitivity TSPO PET imaging
No full textNeuroinflammation is associated with a number of brain diseases, making it a common feature of cerebral pathology. Among the best-known biomarkers for neuroinflammation in Positron Emission Tomography (PET) research is the 18 kDa translocator protein (TSPO). This study aims to investigate the binding kinetics of a novel TSPO PET radiotracer, [18F]LW223, in mice and specifically assess its volume of non-displaceable binding (VND) in brain as well as investigate the use of simplified analysis approaches for quantification of [18F]LW223 PET data. Adult male mice were injected with [18F]LW223 and varying concentrations of LW223 (0.003–0.55 mg/kg) to estimate VND of [18F]LW223. Dynamic PET imaging with arterial input function studies and radiometabolite studies were conducted. Simplified quantification methods, standard uptake values (SUV) and apparent volume of distribution (VTapp), were investigated. [18F]LW223 had low VND in the brain (<10% of total binding) and low radiometabolism (∼15–20%). The 2-tissue compartment model provided the best fit for [18F]LW223 PET data, although its correlation with SUV90–120min or VTapp allowed for [18F]LW223 brain PET data quantification in healthy animals while using simpler experimental and analytical approaches. [18F]LW223 has the required properties to become a successful TSPO PET radiotracer
'Beyond, both the Old World, and the New': Authority and Knowledge in the works of Francis Bacon, with special reference to the New Atlantis
No full textPhDThis study investigates the role of authority in the works of Francis Bacon,
arguing that the issue of authority provides not only an interpretation of New
Atlantis, but an important structural component of his body of works. From
the first manifestation of his philosophical project to his last works of natural
history, authority is an all-pervasive issue - the authority of nature, of
scripture, of the named author, and how authority functions in the
dissemination of natural knowledge. Chapter one argues that the publication
of New Atlantis alongside Sylva sylvarum in 1626/7 was more the result of
William Rawley's need to assert his own authority as the protector and
disseminator of Bacon's textual legacy than an appreciation of the work's own
qualities. Chapter two considers Bacon's views of history and time,
suggesting that Bacon not only conceived of a new, progressive mode of
historical time which would allow for the assertion of a textual authority based
on the records of a civilisation unbroken by the vicissitudes of time, but that
he figured these theories in New Atlantis. Chapter three argues that Bacon
used theology both as defence and imperative to his intellectual programme,
while his attempt to move beyond the deterministic, Calvinist world-view to
allow for multiple possible futures, or `chance': Bacon could then present
experiment as the way of eliminating chance, in order to accelerate the rate of
new discovery. Chapter four investigates Bacon's manipulations of textual
authority, from the early rehearsals of the Instauratio magna to the
performance of reliability in print in Sylva sylvarum. Finally, the afterword
seeks to suggest that the New Atlantis hinges on the issues of authority with
which Bacon engaged throughout his career and writings: in the issue of
authority, Francis Bacon found the beginning and the end of his philosophy
Image and glory of God, glory of man : Evangelicals and Paul's hermeneutics of gender in 1 Corinthians 11:2-16
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
