Critical studies in the Epistle to the Hebrews

Thesis (M.A.)--Boston Universit

The effect of timing noise on targeted and narrow-band coherent searches for continuous gravitational waves from pulsars

Most searches for continuous gravitational-waves from pulsars use Taylor expansions in the phase to model the spin-down of neutron stars. Studies of pulsars demonstrate that their electromagnetic (EM) emissions suffer from \emph{timing noise}, small deviations in the phase from Taylor expansion models. How the mechanism producing EM emission is related to any continuous gravitational-wave (CW) emission is unknown; if they either interact or are locked in phase then the CW will also experience timing noise. Any disparity between the signal and the search template used in matched filtering methods will result in a loss of signal-to-noise ratio (SNR), referred to as `mismatch'. In this work we assume the CW suffers a similar level of timing noise to its EM counterpart. We inject and recover fake CW signals, which include timing noise generated from observational data on the Crab pulsar. Measuring the mismatch over durations of order $\sim 10$ months, the effect is for the most part found to be small. This suggests recent so-called `narrow-band' searches which placed upper limits on the signals from the Crab and Vela pulsars will not be significantly affected. At a fixed observation time, we find the mismatch depends upon the observation epoch. Considering the averaged mismatch as a function of observation time, we find that it increases as a power law with time, and so may become relevant in long baseline searches.Comment: 9 pages, 5 figure

Comparing models of the periodic variations in spin-down and beam-width for PSR B1828-11

We build a framework using tools from Bayesian data analysis to evaluate models explaining the periodic variations in spin-down and beam-width of PSR B1828-11. The available data consists of the time averaged spin-down rate, which displays a distinctive double-peaked modulation, and measurements of the beam-width. Two concepts exist in the literature that are capable of explaining these variations; we formulate predictive models from these and quantitatively compare them. The first concept is phenomenological and stipulates that the magnetosphere undergoes periodic switching between two meta-stable states as first suggested by Lyne et al. The second concept, precession, was first considered as a candidate for the modulation of B1828-11 by Stairs et al.. We quantitatively compare models built from these concepts using a Bayesian odds-ratio. Because the phenomenological switching model itself was informed by this data in the first place, it is difficult to specify appropriate parameter-space priors that can be trusted for an unbiased model comparison. Therefore we first perform a parameter estimation using the spin-down data, and then use the resulting posterior distributions as priors for model comparison on the beam-width data. We find that a precession model with a simple circular Gaussian beam geometry fails to appropriately describe the data, while allowing for a more general beam geometry provides a good fit to the data. The resulting odds between the precession model (with a general beam geometry) and the switching model are estimated as $10^{2.7 \pm 0.5}$ in favour of the precession model.Comment: 20 pages, 15 figures; removed incorrect factor of (2\pi) from equation (15), allowed for arbitrary braking index, and revised prior ranges; overall conclusions unchange

The Effects of Hormonal Contraceptive Use on Perceptions of Social Stress in Women

Hormonal contraceptives are widely used due to their efficiency in preventing pregnancy. Although women are often informed of the physical effects of hormonal contraceptives, there is little emphasis on mental effects, such as increased rates of depression and changes in social perception. The current study examined perceptions of social stress among women before beginning hormonal contraceptives, and two months after using hormonal contraceptives. I hypothesized that women would experience increased social stress after beginning hormonal contraceptives, compared to a control group of women who were also assessed twice. Results did not support this hypothesis; there was no difference in interpersonal stress scores between Time 1 and Time 2 in either group of women. Notably, the sample size was very small and further research is needed to examine the mental effects of hormonal contraceptives to help women become better informed about their reproductive decisions

The Effects of Hormonal Contraceptive Use on Perceptions of Social Stress in Women

Hormonal contraceptives are widely used due to their efficiency in preventing pregnancy. Although women are often informed of the physical effects of hormonal contraceptives, there is little emphasis on mental effects, such as increased rates of depression and changes in social perception. The current study examined perceptions of social stress among women before beginning hormonal contraceptives, and two months after using hormonal contraceptives. I hypothesized that women would experience increased social stress after beginning hormonal contraceptives, compared to a control group of women who were also assessed twice. Results did not support this hypothesis; there was no difference in interpersonal stress scores between Time 1 and Time 2 in either group of women. Notably, the sample size was very small and further research is needed to examine the mental effects of hormonal contraceptives to help women become better informed about their reproductive decisions

I Hear You: The Everyday Struggle Living with Misophonia

The term misophonia is derivated from the Greek words misos, (hate), and phónè, (voice); it translates as hatred of sound. It is the term used to describe people who are irregularly affected by everyday noises. The first scientific observations by Pawel J. Jastreboff regarding misophonia indicate “individuals with misophonia are sensitive to a specific set of trigger sounds, which are usually recognized since childhood.” These types of sounds tend to be trivial noises, such as chewing or crunching, sniffing, breathing, clicking, lip smacking, and tapping. The noises can trigger an onslaught of negative emotions and violent reactions. This documentary film focuses on exposing the public to a disorder with few comprehensive studies. Interviews conducted with both medical professionals and sufferers of misophonia work together to create a depiction of how the disorder affects all people and why others should be considerate of those impacted by the disorder. The documentary delves into the stressful, emotional, human aspect of misophonia in a way that a scientific journal cannot provide. The intention of this study is to form a connection between the subject and the viewer the a will invoke a stronger desire to understand why this disorder is so difficult to live with

The reliability of using a laser device to assess deceleration ability

An important component of change of direction speed is the ability to decelerate. Objective methods to examine this quality have been rarely reported in the literature. The aim of this study was to investigate the within and between session reliability [intra-class correlation coefficients (ICC), co-efficient of variation (CV), standard error of measurement (SEM) and smallest detectable difference (SDD)] of using a laser-Doppler device (LAVEG) to quantify deceleration ability in 20 amateur rugby union players. Each player performed one familiarisation and two experimental sessions (7 days apart) consisting of three maximal 15 m sprints from a standing start, with an immediate deceleration to a complete stop upon hearing an audible cue at the 15 m mark. Deceleration was evaluated by determining the distance required to decelerate to 75%, 50%, 25% and 0% (‘stopping distance’) of the velocity achieved at 15 m of the maximal sprint. Within-session relative reliability were moderate to good (ICC = 0.64-0.83) with borderline acceptable variation (CV’s = 10.51-16.71%) across all variables. Between-session reliability reported good to excellent relative reliability (ICC = 0.79-0.93) with acceptable absolute reliability, particularly for stopping distance (SEM: 6.54%; SDD 9.11%). The assessment shows promise as a method to quantify deceleration ability in athletes