Background: Iron deficiency (ID) is the most prevalent nutritional deficiency in the world. In children, both inadequate iron and fatty acid (FA) status have been found to have an effect on cognitive and behavioural function, including physical activity behaviour and attention deficit hyperactivity disorder (ADHD)–related behaviour. Aim: To investigate the effects of supplementation with iron and omega–3 fatty acids (n–3 FAs), alone and in combination, on spontaneous motor activity and ADHD–related behaviour in iron deficient primary school children in KwaZulu–Natal. An additional aim was to evaluate the use of the Actical accelerometer as a tool to assess physical activity behaviour. Methods: The study design was a 2x2 factorial, randomized, double–blind and placebo–controlled trial. Iron deficient school children aged six to ten years with or without mild anaemia were included in the study (n = 321). Subjects were randomly assigned to receive one of the following supplement combinations: (1) 420mg docosahexaenoic acid (DHA)/80 mg eicosapentaenoic acid (EPA) + 50mg of iron as ferrous sulphate (Fe); (2) 420mg DHA/80mg EPA + placebo; (3) 50mg of Fe + placebo; (4) placebo + placebo. Supplements were provided four times a week for a duration of 8.5 months (excluding school holidays). Physical activity of a subgroup of subjects (n=98) was recorded on four random school days at baseline, midpoint and endpoint (12 days in total) during three different time periods namely class time 1 (08h00-10h30), break time (10h30–11h00) and class time 2 (11h00–12h00). Classroom behaviour of study subjects was assessed by teachers at baseline and endpoint using the Conners’ Teacher Rating Scale–Revised: Short Forms (CTRS). Iron status indicators and red blood cell (RBC) FA composition were measured at baseline and endpoint. Treatment effects were assessed for activity and CTRS scores. Furthermore, the relationship between activity, CTRS scores and iron/FA status indicators was determined using bivariate correlation and multivariate linear regression analysis. Results: Overall activity of all subjects varied over time from baseline and midpoint to endpoint. A significant cycle x age interaction (P = 0.005) as well as a significant cycle x time period x gender interaction (P = 0.036) was observed on overall activity. There were no significant interactions of cycle or time period with treatment. However, there was a significant main effect of DHA/EPA supplementation for lower class time 1 activity at endpoint (P = 0.014). Biological markers indicating better or poorer iron status were positively and negatively associated with activity at break time, respectively. Subjects in the group receiving both iron and DHA/EPA supplements showed a significant improvement from baseline to endpoint on the cognitive problems/inattention subscale (P = 0.005) of the CTRS. Hyperactivity scores increased iv significantly from baseline to endpoint in all groups (P = 0.006). DHA (r = –.203; P = 0.040) and EPA (r = –.199; P = 0.044) content of RBC were negatively associated with activity at class time 1. No significant associations were observed between activity and CTRS scores at baseline. At endpoint, class time 1 activity was positively associated with all CTRS subscale scores except for the cognitive problems subscale, which only bordered significance (correlation, P = 0.051; regression, P = 0.073). Conclusions: These findings suggest that n–3 FA supplementation may have an influence on ADHD–related behaviour during class time. During school break time when subjects were allowed to move around freely, iron status was positively associated with spontaneous motor activity. Furthermore, the accelerometer might be a useful complimentary tool for assessing both classroom and break time activity behaviour in school children. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2012.

The rising number of the population that present with major depressive disorder has intensified the need to identify and elucidate new biological markers for the diagnosis and treatment of depression. Depression presents with evidence of changes in the nitric oxide (NO) pathway. In this study, levels of various endogenous markers of the NO cascade, viz. nitrite (NO2–), asymmetrical dimethylarginine (ADMA) and arginase II activity, were investigated in the Flinders Sensitive Line (FSL) rat, a genetic animal model of depression. The aim of the current study was to determine if there are differences between these markers in the plasma of the FSL rat compared to its healthy control, the (Flinders Resistant Line) FRL rat, with the possibility of considering their use as biomarkers of depression. Nitrite was chosen as metabolite over nitrate (NO3–) because the dietary intake of nitrite and/or nitrate does not significantly affect nitrite (NO2–) levels in plasma. Although this is of no significance if applied to rats, it is an important factor to be considered when doing clinical studies. For neurochemical determination of nitrite a sensitive fluorometric reversed phase high–performance liquid chromatographic (HPLC) assay was developed to analyze nitrite in human and rat plasma. Derivatization of sample nitrite was performed with 2,3–diaminonaphthalene (DAN) followed by the quantification of the stable and highly fluorescent product, 2,3–naphthotriazole (NAT). Determination of arginase II activity was performed by measuring L–arginine and L–ornithine concentrations in the plasma, while ADMA was measured simultaneously with L–arginine and L–ornithine using liquid chromatography/tandem mass spectrometry, or LC/MS/MS. Plasma nitrite levels of FSL rats were significantly decreased compared to plasma nitrite levels in the FRL rat, but neither the levels of ADMA nor arginase II activity showed a significant difference between the FSL and FRL rat groups. From these results it is concluded that in accordance with previous studies, the NO pathway plays an important role in the pathophysiology of depression, as depicted in the differences found between plasma nitrite levels in the FSL rat compared to its healthy control. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

Background: Iron deficiency (ID) is the most prevalent nutritional deficiency in the world. In children, both inadequate iron and fatty acid (FA) status have been found to have an effect on cognitive and behavioural function, including physical activity behaviour and attention deficit hyperactivity disorder (ADHD)–related behaviour. Aim: To investigate the effects of supplementation with iron and omega–3 fatty acids (n–3 FAs), alone and in combination, on spontaneous motor activity and ADHD–related behaviour in iron deficient primary school children in KwaZulu–Natal. An additional aim was to evaluate the use of the Actical accelerometer as a tool to assess physical activity behaviour. Methods: The study design was a 2x2 factorial, randomized, double–blind and placebo–controlled trial. Iron deficient school children aged six to ten years with or without mild anaemia were included in the study (n = 321). Subjects were randomly assigned to receive one of the following supplement combinations: (1) 420mg docosahexaenoic acid (DHA)/80 mg eicosapentaenoic acid (EPA) + 50mg of iron as ferrous sulphate (Fe); (2) 420mg DHA/80mg EPA + placebo; (3) 50mg of Fe + placebo; (4) placebo + placebo. Supplements were provided four times a week for a duration of 8.5 months (excluding school holidays). Physical activity of a subgroup of subjects (n=98) was recorded on four random school days at baseline, midpoint and endpoint (12 days in total) during three different time periods namely class time 1 (08h00-10h30), break time (10h30–11h00) and class time 2 (11h00–12h00). Classroom behaviour of study subjects was assessed by teachers at baseline and endpoint using the Conners’ Teacher Rating Scale–Revised: Short Forms (CTRS). Iron status indicators and red blood cell (RBC) FA composition were measured at baseline and endpoint. Treatment effects were assessed for activity and CTRS scores. Furthermore, the relationship between activity, CTRS scores and iron/FA status indicators was determined using bivariate correlation and multivariate linear regression analysis. Results: Overall activity of all subjects varied over time from baseline and midpoint to endpoint. A significant cycle x age interaction (P = 0.005) as well as a significant cycle x time period x gender interaction (P = 0.036) was observed on overall activity. There were no significant interactions of cycle or time period with treatment. However, there was a significant main effect of DHA/EPA supplementation for lower class time 1 activity at endpoint (P = 0.014). Biological markers indicating better or poorer iron status were positively and negatively associated with activity at break time, respectively. Subjects in the group receiving both iron and DHA/EPA supplements showed a significant improvement from baseline to endpoint on the cognitive problems/inattention subscale (P = 0.005) of the CTRS. Hyperactivity scores increased iv significantly from baseline to endpoint in all groups (P = 0.006). DHA (r = –.203; P = 0.040) and EPA (r = –.199; P = 0.044) content of RBC were negatively associated with activity at class time 1. No significant associations were observed between activity and CTRS scores at baseline. At endpoint, class time 1 activity was positively associated with all CTRS subscale scores except for the cognitive problems subscale, which only bordered significance (correlation, P = 0.051; regression, P = 0.073). Conclusions: These findings suggest that n–3 FA supplementation may have an influence on ADHD–related behaviour during class time. During school break time when subjects were allowed to move around freely, iron status was positively associated with spontaneous motor activity. Furthermore, the accelerometer might be a useful complimentary tool for assessing both classroom and break time activity behaviour in school children. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2012.

The primary aim of this study was to evaluate the influence of an eight-week fundamental motor skills program on the physical and cognitive development of Grade 1 learners. The Basic Motor Ability Test was used in the evaluation of the 39 learners that formed the experimental group as well as for the 29 learners in the control group. Two additional subtests were included, namely the 400m endurance run and a dynamic balance test. After the initial testing the experimental group participated in an eight-week skills program for 30 minutes a day, four days a week. The program included stability, locomotor and manipulation activities. Hereafter a retest was done. The control group only completes the test and retest and not the skills program. The data of the variables tested were coded in computer format and statistically evaluated. In the processing of the data, the raw datum (performance) was converted to percentile norms. In order to determine if a child had improved in a certain physiological parameter percentile norms are used. The t-test was used to determine if the skills program had a positive influence on the variables tested. Two different t-test were used: the t-test for independent groups and the t-test for paired groups. The experimental research revealed that the skills program did not have a significant influence on most of the tested variables. In some instances the experimental and control groups were not on the same level at the start of the research, which made it more difficult to compare the two groups. For some variables both the experimental and control groups improved which is an indication that the improvement cannot be ascribed to the skills program alone. The following two variables, sit-and-reach and co-ordination (hand-eye) did improve notably and it may be due to the influence of the skills program. In both instances the average performance of the experimental group improved while this improvement was not evident in the control group. The cognitive variables were assessed by a questionnaire administered by each learner’s teacher after the conclusion of the skills program. Only the experimental group was involved. The questionnaire consisted of six questions comprising both categorical and open responses. The cognitive variables that were assessed were the following: 1. venturesome ness; 2. attention and concentration; 3. self esteem; 4. socialization and ability to work in a group; 5. ability to plan; and 6. ability to finish his/her given task. The results indicated that more than half of the learners improved in all the cognitive variables. Socialization and the ability to work in a group improved in most of the learners. / Thesis (DPhil (Human Movement Science))--University of Pretoria, 2005. / Biokinetics, Sport and Leisure Sciences / unrestricted

This research project examined the psychometric properties of the adult learner self-directedness scale (ALSDS). The study assessed the construct validity and reliability of the scale as a measure of adult learner self-directedness for diverse groups of adult learners in the South African open, distance and e-learning higher education (ODeLHE) context. The study also assessed whether the factorial structure of the ALSDS was equivalent for adult learners across gender, race and age groups. Furthermore, the study assessed whether the various socio-demographic groups differed significantly on the sub-scale dimensions of the ALSDS; and explored whether a range of socio-biographical factors predicted adult learner self-directedness. This doctoral study has extended the student’s initial exploratory master’s study on the development and factorial structure of the ALSDS that involved a stratified random sample (N = 1 102) of ODeLHE adult learners. The secondary data set involved a random subsample of n = 747 of the original master’s sample data set. Exploratory structural equation modelling (ESEM), exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) revealed a three-factor solution for the ALSDS, with 15 items loading onto the three factors. The results provided evidence of the construct (convergent and discriminant) validity and internal consistency reliability of the three-factor ALSDS, including the construct equivalence of the scale’s factorial structure across the gender, race and age groups. Significant differences between age, race and gender groups were observed regarding the scale sub-dimensions. The study advances theory on adult learner self-directedness in ODeLHE contexts and contributed evidence of the validity and reliability of a shortened version of the ALSDS as a useful measure of adult learner self-directedness. Psychometric shortcomings to be addressed in future research were also directedness. Psychometric shortcomings to be addressed in future research were also highlighted. Practically, the study highlighted assessing adult learners’ success orientation in ODeLHE, active academic activity and strategic utilisation of resources as aspects of enhancing their self-directedness. Support practices should be considered for especially females, black Africans and younger learner cohorts. ODeLHE practices should also consider learners’ mark for English, gender, access to library, number of modules and who students support financially as factors influencing learners’ level of self-directedness. / Abstract/summary in English, Afrikaans and isiZulu / Die navorsingsprojek het die psigometriese eienskappe van die selfgerigtheidskaal vir die volwasse leerder (ALSDS) ondersoek. Die studie het die konstruk-geldigheid en -betroubaarheid van die skaal geassesseer as 'n maatstaf van selfgerigtheid by volwasse leerders vir diverse groepe van volwasse leerders in die Suid-Afrikaanse ope, afstands- en e-leer-hoëronderwyskonteks (ODeLHE). Die studie het ook geassesseer of die fakulteitstruktuur van die ALSDS gelykstaande was vir volwasse leerders oor geslags-, rasse- en ouderdomsgroepe heen. Verder het die studie geassesseer of die verskeie sosiodemografiese groepe beduidend verskil het op die subskaal-dimensies van die ALSDS en ondersoek of 'n reeks sosiobiografiese faktore selfgerigtheid by volwasse leerders voorspel het. Hierdie doktorale studie het uitgebrei op die student se aanvanklike verkennende meesterstudie oor die ontwikkeling en fakulteitstruktuur van die ALSDS wat 'n gestratifiseerde ewekansige steekproef van ODeLHE-volwasse leerders behels het (N = 1 102). Die sekondêre datastel het 'n ewekansige substeekproef behels van n = 747 van die oorspronklike meestersteekproef-datastel. Verkennende strukturele vergelykingsmodellering, verkennende faktorontleding en bekragtigende faktorontleding het 'n driefaktor-oplossing vir die ALSDS onthul, met 15 items wat op die drie faktore gelaai is. Die resultate verskaf bewyse van die konstruk (konvergerende en diskriminerende) geldigheid en interne konsekwentheid en betroubaarheid van die driefaktor-ALSDS, insluitende die konstruk-ekwivalensie van die skaal se fakulteitstruktuur oor die geslags, rasse- en ouderdomsgroepe heen. Beduidende verskille tussen ouderdoms-, rasse- en geslagsgroepe is waargeneem rakende die skaalsubdimensies. Die studie bevorder teorie oor selfgerigtheid by volwasse leerders in ODeLHE-kontekste en dra bewyse van die geldigheid en betroubaarheid van 'n verkorte weergawe van die ALSDS as 'n nuttige maatstaf van selfgerigtheid by volwasse leerders. Psigometriese tekortkomings wat in toekomstige navorsing hanteer kan word, is ook beklemtoon. Prakties gesproke beklemtoon die studie die assessering van volwasse leerders se sukses-oriëntering in ODeLHE, aktiewe akademiese aktiwiteit en strategiese gebruik van hulpbronne as aspekte om hul selfgerigtheid te bevorder. Ondersteuningspraktyke moet oorweeg word vir veral vroue, swart Afrikaners en jonger leerderkohorte. ODeLHE-praktyke moet ook leerders se punt vir Engels, geslag, toegang tot 'n biblioteek, aantal modules en wie studente finansieel ondersteun, oorweeg as faktore wat leerders se vlak van selfgerigtheid beïnvloed. / Le projekthi yocwaningo, ihlola ama-psychometric properties of the adult learner self-directedness scale (ALSDS). Ucwaningo luhlola i-construct validity nokuthembeka kwe-scale njengendlela yokukala i-adult self-directedness kumaqembu ehlukene abafundi abadala kwisimo semfundo evulekile lapho abantu abafunda bekude esibizwa nge-South African open, distance and e-learning higher education (ODeLHE). Ucwaningo lubuye lwahlola nokuthi ngabe isimo ngamaqiniso e-ALSDS siyalingana yini kubafundi abadala kumaqembu obubili, bezinhlanga ezehlukene ngokwebala kanye nabantu beminyaka ehlukene. Kanti futhi okunye, ucwaningo, luhlola ukuthi ngabe amaqembu emikhakha ehlukene ngokwe-sociodemographic ehlukene kakhulu maqondana nama-dimention e-ALSDS acutshungulwayo ukuthi ngabe ama-range emibandela yama-sociodemographic abonelela noma aqagela inqubo ye-adult leaner self-directedness. Lolu cwaningo lweziqu ze-doctoral study lubheke nocwaningo lokuqala lwabafundi be-masters ngentuthuko yesakhiwo se-factoral structure ye-ALSDS ebandakanye amasampuli akhethwe nje ngaphandle kokukhetha noma ukubeka imibandela ethize, okwaziwa nge-stratified random sample ye (N = 1 102) yabafundi abadala be-ODeLHE. Isethi ye-data yesekondari yona ibandakanya i-random subsample of n = 747 yesethi ye-data yabafundi bokuqala be-masters. I-Exploratory structural equation modelling, i-exploratory factor analysis kanye ne-confirmatory factor analysis eziveze izixazululo ezintathu ngama-ALSDS kuma-ayithemu angu 15 afakelwe kuma-factor amathathu. Imiphumela iveza ubufakazi be-construct (i-convergent and discriminant) validity kanye ne-internal consistency reliability yama-factor amathathu e-ALSDS abandakanya i- ix construct equivalence ye-scale's factorial structure, ukunqamuleza kumaqembu ngobulili, izinhlanga ezehlukene ngokwebala kanye neminyaka yobudala ehlukene. Umehluko osemqoka phakathi kweminyaka yobudala, izinhlanga ezehlukene ngokwebala kanye namaqembu eminyaka ehlukene uye wabonakaka maqondana ne-scale sub-dimensions. Ucwaningo luqhubela phambili ithiyori kwizimo zabafundi zokuziqhuba ngokufunda ezibizwa i-adult learner self-directedness kwi-ODeLHE, kanti futhi ithela esivivaneni kwi-reliability ye-version efinyeziwe ye-ALSDS njengesikali esiwusizo kwi-adult learner self-directedness. Okuyizihibe nge-psychometric okufanele kubhekwane nakho ngocwaningo lwangekusasa, kuye kwavezwa kwagqanyiswa. Ngokubonakala ngendlela ebambekayo, ucwaningo lugqamise ukuhlolwa kwempumelelo yabafundi abadala kwi-ODeLHE, umsebenzi omatasatasa we-akhademiki kanye nokusetshenziswa ngendlela yamasu abambekayo kwemithombo njengengxenye yokuthuthukisa i-self-directedness. Izinkambiso zokusekela kumele zibonelelwe, ikakhulukazi kwabesimame, abamnyama bama-Afrika kanye nabafundi abasebasha. Izinkambiso ze-ODeLHE kumele zibonelele namamaki abafundi olimi lwesiNgisi (i-English), ubulili, ukufinyelela emalayibhrari, inani lama-module kanye nokuthi ngabe abafundi bondla obani ngokwezimali njengemibandela enomthelela kwinqubo yokuthi abafundi bakwazi ukuziqhubela phambili ngokwenqubo ye-self-directedness. / Business Management / D.Com. (Business Management)