Countable Short Recursively Saturated Models of Arithmetic

Short recursively saturated models of arithmetic are exactly the elementary initial segments of recursively saturated models of arithmetic. Since any countable recursively saturated model of arithmetic has continuum many elementary initial segments which are already recursively saturated, we turn our attention to the (countably many) initial segments which are not recursively saturated. We first look at properties of countable short recursively saturated models of arithmetic and show that although these models cannot be cofinally resplendent (an expandability property slightly weaker than resplendency), these models have non-definable expansions which are still short recursively saturated

The vertigo of the beast: thinking animals in literature

This thesis begins with the claim that the most productive and stimulating manner of addressing the question of the animal is through an engagement with the writings of Jacques Derrida. In particular, it picks up on his comment in The Animal that Therefore I Am that “thinking concerning the animal, if there is such a thing, derives from poetry.” As such, the thesis explores the specific ways in which the resources of literature can be used in order to address what is possibly the most pressing ethical task of modern humanity. One of the central questions of the thesis concerns how what Derrida calls carnophallogocentrism can be confronted by literature. Through readings of Herman Melville’s Moby-Dick and the poetry and short stories of D.H. Lawrence, I explore how literature is uniquely placed to offer a sense of the radical otherness of nonhuman animals. In perhaps a contradictory manner, I also examine how literary resources can be used to evoke a sense of pity for nonhumans. There are two further important, and connected, areas of enquiry. The first relates to the position of man who is constructed in opposition to nonhuman animals and is given the right to put nonhumans to death. As such, I study how a variety of texts, chiefly J.M. Coetzee’s Foe and Philip Roth’s American Pastoral, reveal the fragility of some of the chief notions of humanism and give way to what has been theorised as posthumanism. The second engages with what Derrida calls “eating well.” This is a question which receives its most thorough investigation through a reading of Margaret Atwood’s dystopian Maddaddam trilogy

Sleep Timing in Late Autumn and Late Spring Associates With Light Exposure Rather Than Sun Time in College Students

Timing of the human sleep-wake cycle is determined by social constraints, biological processes (sleep homeostasis and circadian rhythmicity) and environmental factors, particularly natural and electrical light exposure. To what extent seasonal changes in the light-dark cycle affect sleep timing and how this varies between weekdays and weekends has not been firmly established. We examined sleep and activity patterns during weekdays and weekends in late autumn (standard time, ST) and late spring (daylight saving time, DST), and expressed their timing in relation to three environmental reference points: clock-time, solar noon (SN) which occurs one clock hour later during DST than ST, and the midpoint of accumulated light exposure (50% LE). Observed sleep timing data were compared to simulated data from a mathematical model for the effects of light on the circadian and homeostatic regulation of sleep. A total of 715 days of sleep timing and light exposure were recorded in 19 undergraduates in a repeated-measures observational study. During each three-week assessment, light and activity were monitored, and self-reported bed and wake times were collected. Light exposure was higher in spring than in autumn. 50% LE did not vary across season, but occurred later on weekends compared to weekdays. Relative to clock-time, bedtime, wake-time, mid-sleep, and midpoint of activity were later on weekends but did not differ across seasons. Relative to SN, sleep and activity measures were earlier in spring than in autumn. Relative to 50% LE, only wake-time and mid-sleep were later on weekends, with no seasonal differences. Individual differences in mid-sleep did not correlate with SN but correlated with 50% LE. Individuals with different habitual bedtimes responded similarly to seasonal changes. Model simulations showed that light exposure patterns are sufficient to explain sleep timing in spring but less so in autumn. The findings indicate that during autumn and spring, the timing of sleep associates with actual light exposure rather than sun time as indexed by SN

Urban sloths : public knowledge, opinions, and interactions

Free-range sloths living in an urban environment are rare. In this study, the opinions, attitudes, and interactions with a population of Bradypus variegatus were investigated through short, structured interviews of people in the pubic square where the sloths live, in addition to informal, opportunistic observations of human-sloth interactions. A questionnaire was applied to people in the square where the sloths reside, and informal, opportunistic observations of human-sloth interactions were made. 95% of respondents knew of the sloths’ existence in the square and 87.8% liked their presence. Opinions about population size differed greatly and younger people were concerned as to whether the square was an appropriate place for them. Some human-sloth interactions showed the consequences of a lack of biological knowledge. People initiated all sloth-human interactions. The fact that sloths are strictly folivorous has avoided interactions with humans and, consequently, mitigated any negative impacts of the human-animal interaction on their wellbeing. These results demonstrate that, while there is a harmonious relationship between people and sloths, actions in environmental education of the square’s public could be beneficial for the sloths

Oil and women's political participation: a sub-national assessment of the role of protests and NGOs in Nigeria

The resource curse literature, which links natural resource abundance with negative political and economic outcomes, is largely based on large-N cross-national studies. This thesis examines the effects of oil production on women’s political participation at the sub-national level, comparing the 36 states in the Nigerian federation, of which some are oil-producing. Shedding new light on the negative effects of oil production at the local and community level, and exploring the gender-related dimensions of the resource curse, I argue that the effect of oil varies across different forms of political activity: while oil production may have a negative impact on women’s legislative participation, it can also have a positive impact on non-formal types of political participation, specifically protest and NGO activity. I further suggest that the underlying trigger for both of these effects is oil’s impact on women’s work, which is manifested differently at national and local levels. The analysis is based on a mixed-methods approach that combines quantitative and qualitative tools, including original datasets on oil production and legislative participation, women’s protests, and women-led NGOs across Nigeria’s states. The combination of evidence offers a wide-ranging repertoire of the impact of oil on women. Drawing on historical evidence and women’s testimonies, this thesis suggests that oil production has negatively affected women’s labour force participation in Nigeria, while women’s work in oil-producing states has been further diminished due to environmental degradation and regional militarisation. The extremely low levels of female legislative participation in Nigeria at both the national and state levels are linked with the negative impact of oil on women’s work. Analysing a dataset of press reports and a directory of Nigerian NGOs to compare oil and non-oil producing states in the Nigerian federation, this thesis finds strong evidence for the impact of oil on women’s non-formal political participation at the local level, in oil-producing states. Thus, evidence from Nigeria suggests that oil production may have a dual effect on women’s political participation – undermining formal participation while increasing non-formal participation,a finding that adds to our understanding of the resource curse, women’s political participation, and the link between the two

Spectroscopic characterization of reaction centers of the (M)Y210W mutant of the photosynthetic bacterium Rhodobacter sphaeroides

The tyrosine-(M)210 of the reaction center of Rhodobacter sphaeroides 2.4.1 has been changed to a tryptophan using site-directed mutagenesis. The reaction center of this mutant has been characterized by low-temperature absorption and fluorescence spectroscopy, time-resolved sub-picosecond spectroscopy, and magnetic resonance spectroscopy. The charge separation process showed bi-exponential kinetics at room temperature, with a main time constant of 36 ps and an additional fast time constant of 5.1 ps. Temperature dependent fluorescence measurements predict that the lifetime of P* becomes 4–5 times slower at cryogenic temperatures. From EPR and absorbance-detected magnetic resonance (ADMR, LD-ADMR) we conclude that the dimeric structure of P is not significantly changed upon mutation. In contrast, the interaction of the accessory bacteriochlorophyll BA with its environment appears to be altered, possibly because of a change in its position

Identification of Cellular Targets of MicroRNA-181a in HepG2 Cells: A New Approach for Functional Analysis of MicroRNAs

<div><p>MicroRNAs (miRNAs) are known to play a part in regulating important cellular processes. They generally perform their regulatory function through their binding with mRNAs, ultimately leading to a repression of target protein expression levels. However, their roles in cellular processes are poorly understood due to the limited understanding of their specific cellular targets. Aberrant levels of miRNAs have been found in hepatocellular carcinoma (HCC) including miR-181a. Using bioinformatics analysis, cyclin-dependent kinase inhibitor 1B (CDKN1β) and transcriptional factor E2F7 were identified as potential targets of miR-181a. Validation analysis using surface plasmon resonance (SPR) showed a positive binding between miR-181a and the 3’UTRs of these two potential mRNA targets. <i>In vivo</i> luciferase assay further confirmed the positive miR-181a:mRNA bindings, where a significant decrease in luciferase activity was detected when HepG2 cells were co-transfected with the 3’UTR-containing reporter plasmids and miR-181a. The potential impact of miR-181a binding to its specific targets on the general cellular behavior was further investigated. Results showed that miR-181a significantly activated the MAPK/JNK pathway which regulates cell proliferation, supporting our recently reported findings. Inhibition of miR-181a, on the other hand, abolished the observed activation. Our findings open up a new approach in designing targeted functional analysis of miRNAs in cellular processes, through the identification of their cellular targets.</p></div