Program Improvement and Practice: In-Service and Pre-Service Student Teaching Reflections

A qualitative study was conducted with graduates (in-service teachers) and pre-service teacher candidates from a traditional elementary education program to explore perceptions of the student teaching process and its impact on teaching philosophy and practices. The program graduates and pre-service teachers described their experience as valuable, but believed their knowledge of pedagogy and classroom management to be deficient. The value of the internship process and implications for program improvement are discussed. Theory without practice is dead, and practice without theory is blind. — Ano

The Design and Synthesis of Ghrelin Analogues as Non‐Invasive GHS‐R1a Imaging Probes

The field of molecular imaging is constantly growing and evolving in order to provide the best possible healthcare for patients in various stages of disease and therapy. Molecular imaging aims to locate specific markers of disease by selectively targeting the markers of interest with high selectivity and visualizing the accumulation using external detection. The growth hormone secretagogue receptor-1a (GHS-R1a) has been shown to be involved in various important biological functions such as energy homeostasis and cardiac contractility. GHS-R1a has shown involvement in proliferation, migration and cell invasion of specific cancer subtypes. Therefore, targeting GHS-R1a is an important marker of different disease states and would be advantageous to selectively target for diagnostic and therapeutic purposes. This thesis will document the development of peptide-based molecular imaging agents capable of targeting GHS-R1a with high affinity designed off the structure of ghrelin, the endogenous ligand for GHS-R1a. Chapter 2 discusses the synthesis and evaluation of gallium-69/71 and gallium-68 labelled ghrelin(1-19) analogues. The first generation of ghrelin analogues was designed to detect GHS-R1a by positron emission tomography (PET). Chelation of gallium had a positive effect on binding affinity to GHS-R1a resulting in an IC50 comparable to natural ghrelin(1-28). Preclinical evaluation of HT1080/GHSR-1a xenografts showed higher SUVR values than the HT1080 xenograft with no GHS-R1a. Chapter 3 discusses the second generation of ghrelin analogues that were further truncated to eight amino acids. A structural activity study investigated residues 1, 3, 4, and 8 to determine whether amino acid substitutions produce the best binding affinity GHS-R1a. The optimized ghrelin analogue has 12-fold higher binding affinity to GHS-R1a than natural ghrelin. New radiochemical syntheses were reported for a 6-[ 18F]-fluoro-2-pentafluorophenylnaphthoate prosthetic group. The lead peptide analogue was radiolabelled in a 3% radiochemical yield and resulted in the first fluorine-18 labelled ghrelin(1-8) analogue with greater affinity to GHS-R1a. ii The final chapter describes the effects of targeting GHS-R1a with a dimerized ghrelin(1-8) peptide. Dimerizing other peptide targeting entities has increased binding affinity to the target however, this is not the case found with ghrelin. The in vitro kinetics were evaluated using fluorescence microscopy in GHS-R1a expressing cells. All three chapters discuss the systematic modification of an endogenous peptide ligand into a high affinity, PET imaging agent through classical methods of peptide modification and radiochemistry

East salt sparingly - sprinkle, don\u27t shake!

The salt-blood pressure hypothesis states that an excessive salt intake leads to an increase in blood pressure in genetically susceptible persons and, if high intake is maintained long term, ultimately leads to sustained hypertension. It is estimated that about 3.3 million South Africans (12.6% and 16.3% of adult men and women, respectively) are hypertensive. However, not all subjects within a particular population respond equally to exposure to high-salt diets. Methods to identify those who are \u27salt sensitive\u27 remain in the research domain; therefore a population approach to the restriction of dietary salt intake is warranted. The message to \u27eat salt sparingly\u27 will not interfere with the current nutritional and legal requirements regarding iodation of table salt. A salt intake as low as 5 g per day would provide an adequate amount of iodine, provided the salt is sufficiently iodated. Dietary factors other than sodium which have been shown to influence blood pressure include potassium, magnesium, calcium and alcohol. The \u27Dietary Approaches to Stop Hypertension\u27 (DASH) randomised controlled trial found that subjects fed a diet rich in fruit and vegetables for 8 weeks significantly reduced both systolic and diastolic blood pressure, compared with subjects on a typical American control diet. A \u27combination\u27 diet, rich in fruit, vegetables and low-fat dairy products, and with a reduced saturated and total fat intake, resulted in an even greater reduction in blood pressure. Translated into a practical diet, this information suggests a daily diet that includes large amounts of fruit and vegetables, a moderate intake of low-fat dairy products, lean meat and chicken, and a prudent alcohol intake. Salt should be used sparingly, if at all, at the table and in the preparation of meals, and the intake of processed foods high in salt should be limited. This would result in a reduction in intake from an average of around 9 g salt to about 6 g salt per day, which is the current USA recommendation. These blood pressure-related recommendations incorporate many of the various foodbased dietary guidelines, emphasising that the recommendations are congruent and mutually substantiative

Performance of three-photon PET imaging: Monte Carlo simulations

We have recently introduced the idea of making use of three-photon positron annihilations in positron emission tomography. In this paper the basic characteristics of the three-gamma imaging in PET are studied by means of Monte Carlo simulations and analytical computations. Two typical configurations of human and small animal scanners are considered. Three-photon imaging requires high energy resolution detectors. Parameters currently attainable by CdZnTe semiconductor detectors, the technology of choice for the future development of radiation imaging, are assumed. Spatial resolution is calculated as a function of detector energy resolution and size, position in the field of view, scanner size, and the energies of the three gamma annihilation photons. Possible ways to improve the spatial resolution obtained for nominal parameters: 1.5 cm and 3.2 mm FWHM for human and small animal scanners, respectively, are indicated. Counting rates of true and random three-photon events for typical human and small animal scanning configurations are assessed. A simple formula for minimum size of lesions detectable in the three-gamma based images is derived. Depending on the contrast and total number of registered counts, lesions of a few mm size for human and sub mm for small animal scanners can be detected

Do red deer stags (Cervus elaphus) use roar fundamental frequency (F0) to assess rivals?

It is well established that in humans, male voices are disproportionately lower pitched than female voices, and recent studies suggest that this dimorphism in fundamental frequency (F0) results from both intrasexual (male competition) and intersexual (female mate choice) selection for lower pitched voices in men. However, comparative investigations indicate that sexual dimorphism in F0 is not universal in terrestrial mammals. In the highly polygynous and sexually dimorphic Scottish red deer Cervus elaphus scoticus, more successful males give sexually-selected calls (roars) with higher minimum F0s, suggesting that high, rather than low F0s advertise quality in this subspecies. While playback experiments demonstrated that oestrous females prefer higher pitched roars, the potential role of roar F0 in male competition remains untested. Here we examined the response of rutting red deer stags to playbacks of re-synthesized male roars with different median F0s. Our results show that stags’ responses (latencies and durations of attention, vocal and approach responses) were not affected by the F0 of the roar. This suggests that intrasexual selection is unlikely to strongly influence the evolution of roar F0 in Scottish red deer stags, and illustrates how the F0 of terrestrial mammal vocal sexual signals may be subject to different selection pressures across species. Further investigations on species characterized by different F0 profiles are needed to provide a comparative background for evolutionary interpretations of sex differences in mammalian vocalizations

Aging with Elevated Autistic Traits: Cognitive Functioning Among Older Adults with the Broad Autism Phenotype

Background: Little is known about the impact of aging with autism spectrum disorder (ASD) on cognition. As a first step in addressing this gap in our knowledge, the current study examined cognitive functioning among older adults with elevated, but subclinical levels of autistic traits (i.e., the Broad Autism Phenotype; BAP) compared to older adults without the BAP. Method: Forty older adults (aged 60-91, M=73 years) were recruited and classified as meeting criteria for the BAP (n=20) or not (control older adults, COA; n=20). Different components of executive function as well as episodic memory were measured using standardized performance-based neuropsychological assessments in addition to a self-report questionnaire of executive function difficulties. Results: Despite no differences in age, sex ratio, educational history or IQ, the BAP group demonstrated poorer performance on measures of executive function and episodic memory compared to the COA group. The BAP group also self-reported more executive function difficulties in everyday settings. Moreover, differences in working memory and attentional shifting were maintained after accounting for the influences of IQ and both depression and anxiety symptoms. Conclusions: These findings suggest that aging with the BAP confers additional risk to cognitive function for older adults. As the BAP forms a bridge in the continuum from typical to atypical levels of autistic traits, these findings suggest that individuals with ASD might also incur cognitive costs as they age into older adulthood

Knowledge of iodine nutrition in the South African adult population

OBJECTIVES: To determine the level of knowledge regarding iodine nutrition and its relationship with socio-economic status in the South African population. DESIGN: A cross-sectional population survey collecting questionnaire information on knowledge of iodine nutrition and sociodemographic variables in a multistage, stratified, cluster study sample, representative of the adult South African population. SETTING: Home visits and personal interviews in the language of the respondent. SUBJECTS: Data were collected from one adult in each of the selected 2164 households, and the participation rate was 98%. RESULTS: Only 15.4% of respondents correctly identified iodised salt as the primary dietary source of iodine, 16.2% knew the thyroid gland needs iodine for its functioning, and a mere 3.9% considered brain damage, and 0.8% considered cretinism, as the most important health consequence of iodine deficiency. Compared with respondents from high socio-economic households, respondents from low socio-economic households were considerably less informed about aspects of iodine nutrition covered in this study. CONCLUSIONS: The knowledge level of iodine nutrition is low among South Africans, particularly among the low socio-economic groups. These data suggest that the international emphasis on brain damage resulting from iodine deficiency has not been conveyed successfully to the consumer level in this country

Social Support and Links to Quality of Life Among Middle and Older Age Autistic Adults

Social support has a positive impact on quality of life (QoL) in neurotypical older adults and young autistic adults, but the association for older autistic adults is unclear. Autistic adults (n=388; mean age=40-83 years) were recruited via Simons Powering Autism Research for Knowledge research match. Participants completed questionnaires online querying demographic information, depression and anxiety symptomatology, QoL (Physical, Psychological, Social, Environmental, Autism-specific) and social support (instrumental, subjective and social interactions). Regression analyses examined whether different aspects of social support explained the variance in each domain of QoL. A significant proportion of the variance (36-58%) in QoL was explained. Subjective social support significantly contributed to the models for all aspects of QoL; Physical and Psychological QoL were also explained by social interactions, whereas Social, Environmental and Autism-specific QoL were additionally explained by instrumental support. Social support is an important contributor to the QoL of middle-aged and older autistic adults, after accounting for demographic factors and depression. Further studies are required to understand whether age-related changes in social support and QoL are the same for autistic as non-autistic older adults in order to identify and implement appropriate support

Zero range potential for particles interacting via Coulomb potential: application to electron positron annihilation

The zero range potential is constructed for a system of two particles interacting via the Coulomb potential. The singular part of the asymptote of the wave function at the origin which is caused by the common effect of the zero range potential singularity and of the Coulomb potential is explicitly calculated by using the Lippmann-Schwinger type integral equation. The singular pseudo potential is constructed from the requirement that it enforces the solution to the Coulomb Schr\"odinger equation to possess the calculated asymptotic behavior at the origin. This pseudo potential is then used for constructing a model of the imaginary absorbing potential which allows to treat the annihilation process in positron electron collisions on the basis of the non relativistic Schr\"odinger equation. The functional form of the pseudo potential constructed in this paper is analogous to the well known Fermi-Breit-Huang pseudo potential. The generalization of the optical theorem on the case of the imaginary absorbing potential in presence of the Coulomb force is given in terms of the partial wave series