Distinguishing models of reionization using future radio observations of 21-cm 1-point statistics

We explore the impact of reionization topology on 21-cm statistics. Four reionization models are presented which emulate large ionized bubbles around over-dense regions (21CMFAST/ global-inside- out), small ionized bubbles in over-dense regions (local-inside-out), large ionized bubbles around under-dense regions (global-outside-in) and small ionized bubbles around under-dense regions (local-outside-in). We show that first-generation instruments might struggle to distinguish global models using the shape of the power spectrum alone. All instruments considered are capable of breaking this degeneracy with the variance, which is higher in outside-in models. Global models can also be distinguished at small scales from a boost in the power spectrum from a positive correlation between the density and neutral-fraction fields in outside-in models. Negative skewness is found to be unique to inside-out models and we find that pre-SKA instruments could detect this feature in maps smoothed to reduce noise errors. The early, mid and late phases of reionization imprint signatures in the brightness-temperature moments, we examine their model dependence and find pre-SKA instruments capable of exploiting these timing constraints in smoothed maps. The dimensional skewness is introduced and is shown to have stronger signatures of the early and mid-phase timing if the inside-out scenario is correct.Comment: 18 pages, 13 figures, updated to agree with published versio

The impact of spin temperature fluctuations on the 21-cm moments

This paper considers the impact of Lyman-alpha coupling and X-ray heating on the 21-cm brightness-temperature one-point statistics (as predicted by semi-numerical simulations). The X-ray production efficiency is varied over four orders of magnitude and the hardness of the X-ray spectrum is varied from that predicted for high-mass X-ray binaries, to the softer spectrum expected from the hot inter-stellar medium. We find peaks in the redshift evolution of both the variance and skewness associated with the efficiency of X-ray production. The amplitude of the variance is also sensitive to the hardness of the X-ray SED. We find that the relative timing of the coupling and heating phases can be inferred from the redshift extent of a plateau that connects a peak in the variance's evolution associated with Lyman-alpha coupling to the heating peak. Importantly, we find that late X-ray heating would seriously hamper our ability to constrain reionization with the variance. Late X-ray heating also qualitatively alters the evolution of the skewness, providing a clean way to constrain such models. If foregrounds can be removed, we find that LOFAR, MWA and PAPER could constrain reionization and late X-ray heating models with the variance. We find that HERA and SKA (phase 1) will be able to constrain both reionization and heating by measuring the variance using foreground-avoidance techniques. If foregrounds can be removed they will also be able to constrain the nature of Lyman-alpha coupling.Comment: 16 pages, 13 figure, 1 table. Accepted for publication in MNRA

Down Elk: A Collection of Poems.

This creative thesis is a collection of poems which represent a necessary journey to reconcile my relationship with the people, places, and values of Southern Appalachia, my home that is both stifling and liberating. Growing up in the Appalachian Mountains has influenced my character and my writing in ways that are far-reaching and constantly evolving. At different points in my life I have been equally enamored with the red dirt of my childhood and determined to dig my way out of its clutches. I have spread my wings in large cities and invariably found that I longed to get back to my roots. My experiences of mothering and of being someone’s wife, someone’s daughter, as well as my own self are all bound in my ongoing effort to reconcile my past with my present and to flesh out who I want to be among all I am expected to be. Within this juxtaposition I situate Down Elk: A collection of Poems – poems born not only of a childhood steeped in the love of family and secured in the tradition of growing up in the Appalachian South, but also of a life marked with great loss – too much, too soon – and finally, the ways in which all these experiences continue to shape how I now live and raise children in these mountains. The critical introduction explores not only the personal investment I have in these poems, but also considers poets who have been influential to my perspective, like Mary Karr and Linda Parsons Marion, as well as those with whom I share a common subject matter. This introduction also serves as a means of reflecting on my individual craft

International elementary schools and interrupted students : a study of curriculum, pedagogically-engaged time and reading development

Includes bibliographical references (p. 130-142).This dissertation is concerned with the question of how reading development is influenced by the increase of pedagogically-engaged time amongst interrupted students within a particular curriculum. The study arose from observations that students of an interrupted educational background seemed to be achieving at a lower reading level than uninterrupted students - and thus, the study sought to establish the possible reasons and remedies for this problem. This study was primarily located at the American International School of Cape Town (AISCT), Cape Town, South Africa; and secondarily located at the Washington International School, Washington, D.C., United States of America

Other: Poems

This creative thesis is a collection of original poems entitled Other. The poems in Other reflect my study of the aesthetics of poetry as well as that of how women are represented as poets and as the subject of poems. Some of these poems are the product of my particular interest in the use of persona. Most reflect my desire to achieve self-reflection, to write from my experiences and perception, while still maintaining the universality that is an essential element of successful poems. The critical introduction situates my poems within the framework of the poetic mode Personal Classicism—poetry that is emotionally based but relies on formal techniques and controlled elements in order to maintain distance. My primary goal in the critical introduction is to link my poems to the Personal Classicist lineage, which includes H.D., Elizabeth Bishop, and Louise Gluck – to whom I will pay particular attention

Identification and treatment of tobacco dependence among young people in residential homes during the statutory annual health assessment: a retrospective case-note review

Background Rates of tobacco smoking are substantially higher among young people accommodated in residential homes than in the general youth population. Public health guidance from the National Institute for Health and Care Excellence (NICE) recommends that all smokers should be identified, advised to quit, and offered treatment for tobacco dependence during health-care consultations. Opportunities to address tobacco dependence are available for young people in residential care through the annual statutory health review assessment (HRA). However, little is known about the extent to which HRA is used to address tobacco dependence among this population. We aimed to assess smoking-related recording and clinical practice during the HRA. Methods A retrospective review of the statutory health assessment forms of all young people accommodated in residential homes by an English local authority in the East Midlands between June 1, 2013, and May 31, 2014, was conducted. Practice was assessed with standards developed from statutory and NICE guidance relating the recording of smoking-related information during annual health assessments. Descriptive statistics were used to summarise the characteristics of the young people and the level of smoking-related recording. Associations between categorical variables were analysed with χ2 tests, and one-way ANOVA was used to assess continuous data. Ethics approval was provided by the Families, Young People & Children Clinical Audit, Standards, Effectiveness and Research Group of Leicestershire Partnership NHS Foundation Trust, and data were accessed under Section 251 of the NHS Act. Findings 31 young people were included in the review, of whom 30 (97%) had completed a statutory HRA. Inquiries about smoking were made in 23 (77%) instances. 12 (52%) of those who had participated in the HRA and who were asked about smoking were identified as smokers. Nine (75%) of these smokers engaged in discussions about their smoking and were offered treatment for tobacco dependence: two (22%) accepted a referral for treatment. The reasons for declining support for smoking cessation were documented in two (17%) cases. Interpretation Opportunities to address tobacco dependence among young people in residential homes are being missed during the HRA. Further research should explore clinician practice and attitudes to addressing tobacco dependence during the HRA and the perceptions of these young people in relation to receiving smoking cessation advice and the treatment offered. Funding This study was funded by a UK Centre for Tobacco and Alcohol Studies PhD studentship

Do Raw Milk Sales Help or Harm Local Dairy Economies: The Case of Vermont H.125

This paper concludes that the main impact of H125 will be increased raw milk sales which will result in increased consumer exposure to raw milk, and an increased risk for food borne illness

Quantifying the non-Gaussianity in the EoR 21-cm signal through bispectrum

The epoch of reionization (EoR) 21-cm signal is expected to be highly non-Gaussian in nature and this non-Gaussianity is also expected to evolve with the progressing state of reionization. Therefore the signal will be correlated between different Fourier modes ($k$). The power spectrum will not be able capture this correlation in the signal. We use a higher-order estimator -- the bispectrum -- to quantify this evolving non-Gaussianity. We study the bispectrum using an ensemble of simulated 21-cm signal and with a large variety of $k$ triangles. We observe two competing sources driving the non-Gaussianity in the signal: fluctuations in the neutral fraction ($x_{\rm HI}$) field and fluctuations in the matter density field. We find that the non-Gaussian contribution from these two sources vary, depending on the stage of reionization and on which $k$ modes are being studied. We show that the sign of the bispectrum works as a unique marker to identify which among these two components is driving the non-Gaussianity. We propose that the sign change in the bispectrum, when plotted as a function of triangle configuration $\cos{\theta}$ and at a certain stage of the EoR can be used as a confirmative test for the detection of the 21-cm signal. We also propose a new consolidated way to visualize the signal evolution (with evolving $\overline{x}_{\rm HI}$ or redshift), through the trajectories of the signal in a power spectrum and equilateral bispectrum i.e. $P(k)-B(k, k, k)$ space.Comment: 18 pages, 11 figures. Accepted for publication in MNRAS. Replaced to match the accepted versio

Courage and co-creation: Cultural transformation in an academic library

University libraries are transforming to be vibrant and distinctive online and physical spaces that, at their heart, continue to foster the connection of people to ideas. Rapid and continuously changing expectations of clients in the range of services that are delivered by libraries, combined with increasingly demanding resourcing environments are challenges for all library leaders. A library staff culture that is energised, focused and resilient is essential to ensure that service expectations are met or exceeded and that the library retains its valued position in the university. The University Librarian at Curtin University in Australia has initiated and led a library staff culture transformation program over an 18-month period. The program has adopted an empowerment mindset to increase commitment, involvement and optimism amongst library staff. The need for such a transformative program was identified following a particularly difficult period of staff disruption. The ‘Appreciative Inquiry’ dialogic method was used to facilitate a whole of library engagement and activity program that commenced with a two day ‘Library Challenge’ event. The event brought together library staff, students and academics to identify the desired culture along with a roadmap to meet that goal. The Your Voice Satisfaction Survey (Your Voice), a research validated employee satisfaction and engagement survey, was used to evaluate the Curtin University Library culture program with the survey being run before, and during the program’s implementation. Results show significant shifts in staff engagement as the culture program has been rolled out, particularly in the areas of commitment, involvement and positive outlook. This paper will outline the staff culture transformation program at Curtin University Library with an emphasis on the skills and attitudes required by library leaders to ensure success in this critical area of leadership

Smoking and looked-after children: a mixed-methods study of policy, practice, and perceptions relating to tobacco use in residential units

Despite the implementation of smoke-free policies by local authorities and a statutory requirement to promote the health and well-being of looked-after children and young people in England, rates of tobacco use by this population are substantially higher than in the general youth population. A mixed-methods study, comprising a survey of residential care officers in 15 local authority-operated residential units and semi-structured, face-to-face interviews with residential carers in three local authority-operated residential units, was conducted in the East Midlands. Survey data were descriptively analysed; and interview data were transcribed and analysed using thematic framework analysis. Forty-two care officers (18% response rate) completed the survey, and 14 participated in the interviews. Despite reporting substantial awareness of smoke-free policies, a lack of adherence and enforcement became apparent, and levels of reported training in relation to smoking and smoking cessation were low (21%). Potential problems relating to wider tobacco-related harms, such as exploitative relationships; a reliance on tacit knowledge; and pessimistic attitudes towards LAC quitting smoking, were indicated. The findings highlight the need for the development of comprehensive strategies to promote adherence to and enforcement of local smoke-free policy within residential units for looked-after children and young people, and to ensure appropriate support pathways are in place for this population