Nuclear Fragmentation Cross Section Modeling for Space Radiation Applications

One of the most significant challenges to overcome on the journey to Mars is understanding the biological risk associated with the space radiation environment. Radiation transport codes are one of the tools necessary to quantify this risk. Due to the nature of the space radiation environment, it is of great importance that these transport codes are able to describe the breakup of heavy ions into smaller fragments|light ions in particular. For this, event generators within radiation transport codes rely on nuclear fragmentation codes to predict the products of high energy nuclear collisions. This manuscript documents the development of a nuclear fragmentation code: the Relativistic Abrasion-Ablation and Deexcitation Fragmentation Model (RAADFRG). RAADFRG is the product of a collaboration between the University of Tennessee and NASA\u27s Langley Research Center (LaRC), and is being developed for space radiation applications. Currently, total isotopic yield is of primary concern; however, future versions of the model must predict double differential isotopic yields. The collision model is a framework of smaller physics packages, each meant to describe a specific physical phenomenon within the abrasion-ablation heavy ion collision theory. The coalescence model, along with the collision framework architecture and development, are my primary original contributions

Precise Detections of Solar Particle Events and a New View of the Moon

We have invented a new method for detecting solar particle events using data from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO). Using a simple function of the total particle detection rates from four of CRaTER’s six detectors, we can precisely identify solar energetic particle event periods in the CRaTER data archive. During solar quiet periods we map the distribution of a mare‐associated mixture of elements in the lunar regolith using this new method. The new map of the moon probably reflects an as‐yet unknown combination of lunar albedo protons, neutrons, and gamma rays, and most closely resembles Lunar Prospector maps of gamma rays characteristic of thorium and iron. This result will lead to multiple follow‐up studies of lunar albedo particles and may also contribute to the study of diurnally varying hydrogenation of the lunar regolith.Key PointsThe CRaTER instrument on LRO can detect and quantify small solar particle events with a simple new analysis techniqueOur new lunar map of albedo radiation resembles gamma ray maps from Lunar ProspectorFollow‐up studies will investigate contributions from neutrons, protons, and gamma rays, and signatures of hydrogen in lunar regolithPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152796/1/grl60033_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152796/2/grl60033.pd

Clinical characteristics of women captured by extending the definition of severe postpartum haemorrhage with 'refractoriness to treatment': a cohort study

Background: The absence of a uniform and clinically relevant definition of severe postpartum haemorrhage hampers comparative studies and optimization of clinical management. The concept of persistent postpartum haemorrhage, based on refractoriness to initial first-line treatment, was proposed as an alternative to common definitions that are either based on estimations of blood loss or transfused units of packed red blood cells (RBC). We compared characteristics and outcomes of women with severe postpartum haemorrhage captured by these three types of definitions. Methods: In this large retrospective cohort study in 61 hospitals in the Netherlands we included 1391 consecutive women with postpartum haemorrhage who received either ≥4 units of RBC or a multicomponent transfusion. Clinical characteristics and outcomes of women with severe postpartum haemorrhage defined as persistent postpartum haemorrhage were compared to definitions based on estimated blood loss or transfused units of RBC within 24 h following birth. Adverse maternal outcome was a composite of maternal mortality, hysterectomy, arterial embolisation and intensive care unit admission. Results: One thousand two hundred sixty out of 1391 women (90.6%) with postpartum haemorrhage fulfilled the definition of persistent postpartum haemorrhage. The majority, 820/1260 (65.1%), fulfilled this definition within 1 h following birth, compared to 819/1391 (58.7%) applying the definition of ≥1 L blood loss and 37/845 (4.4%) applying the definition of ≥4 units of RBC. The definition persistent postpartum haemorrhage captured 430/471 adverse maternal outcomes (91.3%), compared to 471/471 (100%) for ≥1 L blood loss and 383/471 (81.3%) for ≥4 units of RBC. Persistent postpartum haemorrhage did not capture all adverse outcomes because of missing data on timing of initial, first-line treatment. Conclusion: The definition persistent postpartum haemo

On the analysis of refinable functions with respect to mask factorisation, regularity and corresponding subdivision convergence

Thesis (PhD (Mathematical Sciences))--University of Stellenbosch, 2007.We study refinable functions where the dilation factor is not always assumed to be 2. In our investigation, the role of convolutions and refinable step functions is emphasized as a framework for understanding various previously published results. Of particular importance is a class of polynomial factors, which was first introduced for dilation factor 2 by Berg and Plonka and which we generalise to general integer dilation factors. We obtain results on the existence of refinable functions corresponding to certain reduced masks which generalise similar results for dilation factor 2, where our proofs do not rely on Fourier methods as those in the existing literature do. We also consider subdivision for general integer dilation factors. In this regard, we extend previous results of De Villiers on refinable function existence and subdivision convergence in the case of positive masks from dilation factor 2 to general integer dilation factors. We also obtain results on the preservation of subdivision convergence, as well as on the convergence rate of the subdivision algorithm, when generalised Berg-Plonka polynomial factors are added to the mask symbol. We obtain sufficient conditions for the occurrence of polynomial sections in refinable functions and construct families of related refinable functions. We also obtain results on the regularity of a refinable function in terms of the mask symbol factorisation. In this regard, we obtain much more general sufficient conditions than those previously published, while for dilation factor 2, we obtain a characterisation of refinable functions with a given number of continuous derivatives. We also study the phenomenon of subsequence convergence in subdivision, which explains some of the behaviour that we observed in non-convergent subdivision processes during numerical experimentation. Here we are able to establish different sets of sufficient conditions for this to occur, with some results similar to standard subdivision convergence, e.g. that the limit function is refinable. These results provide generalisations of the corresponding results for subdivision, since subsequence convergence is a generalisation of subdivision convergence. The nature of this phenomenon is such that the standard subdivision algorithm can be extended in a trivial manner to allow it to work in instances where it previously failed. Lastly, we show how, for masks of length 3, explicit formulas for refinable functions can be used to calculate the exact values of the refinable function at rational points. Various examples with accompanying figures are given throughout the text to illustrate our results

Knowledge, attitude and perception of private practitioners based in Gauteng, South Africa, regarding evidence-based practice

Background Evidence-based medicine (EBM) involves the care of patients using the best available evidence from the results of good quality clinical research to guide clinical decision making 1 – 3. By incorporating the principles of Evidence-based Medicine (EBM), the family practitioner would be able to treat a patient according to the best clinical research available. This principle is implemented widely in the USA, Canada, the United Kingdom and Europe. In South Africa, however, EBM is not yet as widely incorporated into family practice. This is so despite the plethora of websites available to practitioners and the relative ease with which applicable research evidence can be found. Very few published studies are available regarding EBM or Evidence–based Practice (EBP) in the South African context. The findings of this study would thus highlight reasons and/ or barriers preventing family practitioners from implementing EBM in their respective practices. This could also lead to further research into possible methods of implementation of EBM into South African family practices. Aim: The aim of the study was to describe the perceptions, knowledge and attitudes of private practitioners regarding evidence based practice and to identify the barriers encountered in evidence based practice. Methods A questionnaire survey of general practitioners in Gauteng, South Africa, was conducted. Questionnaires were distributed to a random sample of practitioners in the Gauteng region. Two hundred and twenty one (221) practitioners participated in the survey and responded to questionnaires mailed to them. The questionnaire was mailed, faxed or e-mailed to the practitioners, which they then completed and returned for statistical analysis. Study design The study design is that of quantitative, statistical analysis (descriptive cross-sectional survey). Setting General practitioners were randomly selected from a list of practitioners in the Gauteng Province. Doing a nationwide survey would have been a mammoth undertaking. It was therefore decided to limit the research to one province and therefore it was only concentrated on practitioners practicing in the Gauteng area. Results It is interesting to note that of the two hundred and twenty one participants in this study; only 10% of the practitioners were against using EBM in their practices. This, however, stands in stark contrast to the 56% of practitioners who do not implement EBM in their practices or make use of the EBM principle at all. The major barriers preventing practitioners from implementing EBM is depicted in the following graph: Lack of time and the training in aspects of Evidence-based medicine were the main barriers preventing the full scale implementation of EBM in family practices in Gauteng. Conclusion Participating Gauteng doctors were in principle, very positive towards the implementation of EBM in their respective practices. Most of the participants agreed that EBM would benefit their patients’ care and treatment. Very few of the participants, however, make use of EBM in practice. A lack of training and time constraints were the main barriers with regards to the implementation of EBM. Proper training of medical students at undergraduate level at faculties of health sciences, would go a long way assisting prospective doctors in mastering the concept of EBM and increasing their overall awareness of EBM. Further definitive research would assist in establishing whether such awareness would be associated with improved implementation of evidence in the form of evidence based guidelines in practice.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaa

Tendense en tematologie in populêre werke oor Suid- Afrikaanse rugby, 1948-1995 : ’n historiografiese studie

Thesis (MA)-- Stellenbosch University, 2013.ENGLISH ABSTRACT: This is a historiographical study of popular rugby history covering the years 1948 to 1995. The aim of this study is to show how this sport is portrayed in popular history writing. This research will focus on the two forms of popular history during this time, namely general rugby history books and biographical works. In order to fulfil its goals, this thesis will identify tendencies and thematology in popular rugby history, as well as explore its development over the years. This work lies on the edge between a study of history and that of literature. By studying the content and literary aspects of the popular works, light will be shed on its ever changing tendencies and thematology. Throughout this thesis, there will be constant use of quotations in order to explain the development of popular rugby historiography over time. By exploring the aforementioned complexities, this study aims to make a contribution to the developing domain of South African sports history.AFRIKAANSE OPSOMMING: Hierdie studie is ’n historiografiese studie van populêre rugby geskiedskrywing, en dek die jare 1948 tot 1995. Die doel is om te dui op hoe dié sport in populêre skrywes uitgebeeld is. Die fokus gaan val op die twee vorme van populêre geskiedskrywing in hierdie tydperk, naamlik algemene rugbygeskiedenisboeke en biografiese werke. Die manier hoe hierdie verhandeling te werk gaan, is om tendense en tematologie in hierdie werke te identifiseer en die verandering daarvan oor die jare, na te volg. Hierdie werk lê op die breekvlak tussen ’n studie van die geskiedenis en die letterkunde. Deur die gewilde rugby skrywes inhoudelik en letterkundig in fyn detail te bestudeer, gaan lig op die veranderende tendense en tematologie gewerp word. Aanhalings word deurgans ingesluit en bespreek om die ontwikkeling van die populêre rugby geskiedskrywing oor die jare te verduidelik. Deur op hierdie kompleksiteite klem te lê, poog die studie om ’n bydrae te lewer tot die steeds ontwikkelende veld van Suid- Afrikaanse sportgeskiedenis

Knowledge, attitude and perception of private practitioners based in Gauteng, South Africa, regarding evidence-based practice

Thesis (MMed)--Stellenbosch University, 2010.BibliographyBackground: Evidence-based medicine (EBM) involves the care of patients using the best available evidence from the results of good quality clinical research to guide clinical decision making 1 – 3. By incorporating the principles of Evidence-based Medicine (EBM), the family practitioner would be able to treat a patient according to the best clinical research available. This principle is implemented widely in the USA, Canada, the United Kingdom and Europe. In South Africa, however, EBM is not yet as widely incorporated into family practice. This is so despite the plethora of websites available to practitioners and the relative ease with which applicable research evidence can be found. Very few published studies are available regarding EBM or Evidence–based Practice (EBP) in the South African context. The findings of this study would thus highlight reasons and/ or barriers preventing family practitioners from implementing EBM in their respective practices. This could also lead to further research into possible methods of implementation of EBM into South African family practices. Aim: The aim of the study was to describe the perceptions, knowledge and attitudes of private practitioners regarding evidence based practice and to identify the barriers encountered in evidence based practice. Methods A questionnaire survey of general practitioners in Gauteng, South Africa, was conducted. Questionnaires were distributed to a random sample of practitioners in the Gauteng region. Two hundred and twenty one (221) practitioners participated in the survey and responded to questionnaires mailed to them. The questionnaire was mailed, faxed or e-mailed to the practitioners, which they then completed and returned for statistical analysis. Study design The study design is that of quantitative, statistical analysis (descriptive cross-sectional survey). Setting General practitioners were randomly selected from a list of practitioners in the Gauteng Province. Doing a nationwide survey would have been a mammoth undertaking. It was therefore decided to limit the research to one province and therefore it was only concentrated on practitioners practicing in the Gauteng area. Results It is interesting to note that of the two hundred and twenty one participants in this study; only 10% of the practitioners were against using EBM in their practices. This, however, stands in stark contrast to the 56% of practitioners who do not implement EBM in their practices or make use of the EBM principle at all. The major barriers preventing practitioners from implementing EBM is depicted in the following graph: Lack of time and the training in aspects of Evidence-based medicine were the main barriers preventing the full scale implementation of EBM in family practices in Gauteng. Conclusion Participating Gauteng doctors were in principle, very positive towards the implementation of EBM in their respective practices. Most of the participants agreed that EBM would benefit their patients’ care and treatment. Very few of the participants, however, make use of EBM in practice. A lack of training and time constraints were the main barriers with regards to the implementation of EBM. Proper training of medical students at undergraduate level at faculties of health sciences, would go a long way assisting prospective doctors in mastering the concept of EBM and increasing their overall awareness of EBM. Further definitive research would assist in establishing whether such awareness would be associated with improved implementation of evidence in the form of evidence based guidelines in practice

Die invloed van die vaderfiguur op die geloofsontwikkeling van die seun

Verhandeling (B. Th.) -- Universiteit van Stellenbosch, 1994.Full text to be digitised and attached to bibliographic record

'n Pastorale groeimodel vir die ontwikkeling van spiritualiteit tydens rousmart

Thesis (MTh) -- Stellenbosch University, 1996.ENGLISH ABSTRACT: Grief pastorate often has the shortcoming where the ministry strategy focuses more on short term involvement than a long term accompaniment. The minister's involvement necessarily focuses on the crisis around the initial shock phase. The duration of the grief process is hardly predictable. The pastor must therefore follow a long term approach. This long term approach must set about in earnest with the interdependence of the grief process on the one hand and on the other hand a growth process. Such an approach can be characterised as a pastoral growth model where Clinebell's growth model is used as the basis. The aim of this pastoral growth model is the development of spirituality. Spirituality is understood as the total human life in communion with God and that includes the following aspects: Identity, intimacy, sinfulness, lordship, mortality, holiness and commitment. Through the holistic character of spirituality the mourner is addressed in totality- in his or her total humanness. This eliminates the danger where the pastorate is guilty, on the one hand of emphasis of the spiritual aspect, on the other hand the human aspect of man. A pastoral growth model for the development of spirituality during grief is a comprehensive, well-grounded pastoral model which could be made use of successfully during grief pastorate.AFRIKAANSE OPSOMMING: Rousmartpastoraat het dikwels die tekortkoming dat die bedieningstrategie meer op korttemyn betrokkenheid ingestel is as op 'n langtermyn begeleidingsproses. Die predikant se betrokkenheid fokus hoofsaaklik op die krisis random die aanvanklike skokfase. Die duur van die rouproses is moeilik voorspelbaar. Die pastor moet daarom 'n langtermyn benadering volg. Hierdie langtermyn benadering moet erns maak met die interafhanklikheid van enersyds die rouproses en andersyds 'n groeiproses. So 'n benadering kan tipeer word as 'n pastorale groeimodel waar Clinebell se groeimodel as basis gebruik word. Die doelstelling van hierdie pastorale groeimodel is die ontwikkeling van spiritualiteit. Spiritualiteit word verstaan as die totale menslike lewe in gemeenskap met God en dit sluit die volgende aspekte in: ldentiteit, intimiteit, sondigheid, heerskappy, sterflikheid, heiligheid en verbondenheid. Vanweë die holistiese karakter van spiritualiteit word die treurende in geheel aangespreek- in sy of haar totale menswees. Dit skakel die gevaar uit dat die pastoraat skuldig kan wees aan ‘n beklemtoning van enersyds die geestelike aspek of andersyds die menslike aspek van die mens. 'n Pastorale groeimodel vir die ontwikkeling van spiritualiteit tydens rousmart is 'n omvattende, begronde pastorale model wat met groot vrug gebruik kan word tydens rousmartpastoraat