Three experiments, each with 24 pregnant female rats as subjects, were conducted. Four experimental diets contained either 7.5 mg tryptophan or 500 mg tryptophan/100 g and either 7.5 ppm or 50 ppm zinc. Dams on the low zinc diets throughout gestation consumed less food and gained less weight than those on the high zinc diets. Reproductive success was less on the low zinc diet. The incidences of maternal mortality, fetal mortality, and reabsorptions were higher in the dams fed a low zinc diet. There were no significant differences in water intake, urine volume, fetal weight, or fetal nitrogen content which were dependent upon dietary treatment. Dams on the low zinc diets had acute renal nephrosis which was most severe when dietary tryptophan levels were high. Fetal zinc content was higher in fetuses from dams fed the high zinc diets. Although the dams on the low zinc diet did exhibit signs of zinc deficiency, the deficiency was not severe enough to affect fetal weight. Diets containing between 6 and 9 ppm were not sufficient for normal parturition. / M. S.

Thesis (MTech (Agriculture))--Cape Peninsula University of Technology, 2018. / Zinc deficiency on various soil types have been reported in arable soils of sub Saharan Africa (SSA) including South Africa. A pot trial was conducted at the Cape Peninsula University of Technology, Wellington campus to investigate the interaction of different application rates of Zn at various soil pH on the grain yield and quality of spring wheat in a completely randomized factorial design replicated three times. The four soil pH tested were: pHA: 5.1, pHB: 5.6, pHC: 6.1, pHD: 6.6 which correspond to lime application at 0, 0.5, 1 and 1.5 t/ha. Five Zn rates (Zn1: 3.5; Zn2: 4.5; Zn3: 5.5 Zn4: 6.5, and Zn5: 7.5 mg /kg soil which correspond to Zn1: 7; Zn2: 9; Zn3: 11; Zn4: 13 and Zn5: 15 kg /ha) were applied at two (planting and flowering) growth stages. Yield and yield component data collected were analyzed using SAS version 9.2 and means were separated by Duncun’s Multiple Range Test (DMRT). The results showed that grain yield and yield components were significantly affected by lime application pHC (6.1): 1t/ha at planting. Zn application at planting had no significant effect on the grain yield and yield components. However, at flowering, the simultaneous increase of Zn along with increase in lime positively affected grain yield and yield components. Plant analysis showed that at both stages (planting and flowering), Zn application, especially at pH 6.6, significantly increased P, K, Ca, Na, Mg Fe, Cu and B concentrations in wheat grain, but the concentrations of N, Mn, Zn and protein remained unaffected. Zn application had no effect on most nutrients due to the presence of lime. While the absence of lime, Zn4: 6.5mg/kg (corresponding to 13kg/ha) significantly increased the nutrients. In addition, Zn3: 5.5mg/kg (corresponding to 11kg/ha) promoted Zn absorption by grain in all treatments.

To assess the prevalence of anemia, we surveyed 10 to 14 month old infants of families with heterogeneous socio-economic backgrounds from four regions of inner-city Montreal. Capillary blood was drawn to measure hemoglobin (Hb), mean corpuscular volume (MCV), and serum ferritin (SF). A home-visit questionnaire assessed infant feeding practices and potential confounding variables. In the overall sample, the prevalence was 14.3% for anemia (Hb≥110 g/L), 9.4% for iron deficiency (SF≤10 mug/L), and 4.3% for iron deficiency anemia (SF≤10 mug/L and Hb≤110 g/L or MCV≤72 fL). There were no significant differences in iron status indices between socio-economic subgroups. Protectors of anemia determined through logistic regression analysis were introduction of cow's milk at or following 9 months of age (OR 0.17 [95% CI 0.056 to 0.540]) and breastfeeding for 6 months or less (OR 0.23 [95% CI 0.086 to 0.637]). Our results suggest that important health inequalities relating to anemia do not currently exist among infants residing in Montreal.

Soybeans (Glycine max L. Merr.) are a symbiont of two beneficial associations: biological nitrogen fixation (BNF) with Bradyrhizobium japonicum, and arbuscular mycorrhizal fungi (AMF). Within the Northern Great Plains of the USA, iron deficiency chlorosis (IDC) of soybean is a yield-limiting factor. The effects of IDC on BNF and AMF are not well defined. This study was conducted to determine the effects of IDC on BNF and AMF. A laboratory study was performed to compare three methods of measuring ureide-N, a product of BNF in soybeans. Field studies in soybean were performed at three locations at eastern N011h Dakota. The experimental design was a factorial combination of three cultivars and three treatments. The three cultivars, in order of decreasing chlorosis susceptibility, were NuTech NT-0886, Roughrider Genetics RG 607, and Syngenta S01-C9 RR. The three treatments were control, Sorghum bicolor L. companion crop planted with the soybean seed, and FeEDDHA applied with the soybean seed. Chlorosis severity was the greatest and least for the NuTech and Syngenta cultivars, respectively. The FeEDDHA treatment decreased chlorosis severity. Ureide levels were abnormally high in plants severely stunted by JDC. The excess accumulation of ureides in IDC-stunted plants suggests that plant growth was reduced more than the rate of nitrogen fixation. The AMF population \vas at an adequate level at all locations and not affected by cultivar or treatment, in general. In the laboratory study, the Patterson et al. method had greater ureide concentrations due to the non-specific measuring of ammonium compounds compared to the Vogels and Van der Drift and Goos methods. / North Dakota Soybean Council

No description available.

Leung, Yeung Yeung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 134-154). / Abstracts in English and Chinese. / CONTENTS --- p.i / ACKNOWLEDGEMENTS --- p.iv / ABSTRACT --- p.v / 論文摘要 --- p.viii / LIST OF FIGURES --- p.x / LIST OF TABLES --- p.xiv / LIST OF ABBREVIATIONS --- p.xv / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Brain iron function and diseases --- p.1 / Chapter 1.1.1 --- Function of iron in the brain --- p.1 / Chapter 1.1.2 --- Iron involved oxidative damage --- p.2 / Chapter 1.1.3 --- Role of iron in neurodegenerative diseases --- p.6 / Chapter 1.1.4 --- Role of iron in Alzheimer's disease --- p.7 / Chapter 1.1.5 --- Deleterious effects of iron in memory function --- p.9 / Chapter 1.2 --- Iron regulation in the brain --- p.10 / Chapter 1.2.1 --- Transport and storage of brain iron --- p.10 / Chapter 1.2.2 --- Iron homeostasis in the brain --- p.14 / Chapter 1.2.3 --- Transport of iron in axon and synapse --- p.17 / Chapter 1.3 --- The hippocampus --- p.19 / Chapter 1.3.1 --- Hippocampus and memory function --- p.19 / Chapter 1.3.2 --- Structure of the hippocampus --- p.20 / Chapter 1.3.3 --- Cell composition in the hippocampus --- p.26 / Chapter 1.3.4 --- Wiring in the hippocampus --- p.28 / Chapter 1.4 --- Synaptic plasticity and long term potentiation --- p.30 / Chapter 1.4.1 --- Basic theory of synaptic plasticity --- p.30 / Chapter 1.4.2 --- Types of synaptic plasticity --- p.30 / Chapter 1.4.3 --- The discovery of long term potentiation --- p.31 / Chapter 1.4.4 --- Long term potentiation --- p.32 / Chapter 1.4.5 --- Cellular mechanism of long term potentiation --- p.33 / Chapter 1.4.6 --- Role of reactive oxygen species in long term potentiation --- p.36 / Chapter 1.5 --- Aim of the study --- p.38 / Chapter 2. --- MATERIALS AND METHODS --- p.39 / Chapter 2.1 --- Rat model of iron overload --- p.39 / Chapter 2.2 --- Multi-electrode field potential measurement --- p.40 / Chapter 2.2.1 --- Acute preparation of hippocampal slices --- p.40 / Chapter 2.2.2 --- Multi-electrode array recording system --- p.41 / Chapter 2.2.3 --- Recording of field excitatory postsynaptic potentials --- p.42 / Chapter 2.2.4 --- Induction of LTP --- p.47 / Chapter 2.2.5 --- Recording of paired-pulse ratio --- p.48 / Chapter 2.3 --- Whole cell patch-clamp recordings --- p.50 / Chapter 2.4 --- Biochemical assays --- p.57 / Chapter 2.4.1 --- Preparation of brain homogenate --- p.57 / Chapter 2.4.2 --- Total iron measurement --- p.57 / Chapter 2.4.3 --- Protein carbonyl measurement --- p.58 / Chapter 2.4.4 --- Determination of reactive oxygen species --- p.60 / Chapter 2.5 --- Drugs and data analysis --- p.61 / Chapter 3. --- RESULTS --- p.62 / Chapter 3.1 --- The acute effects of extracellular iron on synaptic transmission and long-term synaptic plasticity in the hippocampus in vitro --- p.63 / Chapter 3.1.1 --- Effects of ferric ion on basal synaptic transmission --- p.63 / Chapter 3.1.1.1 --- Effect of FAC on basal fEPSPs --- p.63 / Chapter 3.1.1.2 --- Comparison with the effect of AC on basal fEPSPs --- p.69 / Chapter 3.1.2 --- Effects of ferric ion on long-term synaptic plasticity --- p.72 / Chapter 3.1.2.1 --- Effect of acute FAC treatment on LTP --- p.72 / Chapter 3.1.2.2 --- Comparison with the effect of AC on LTP --- p.75 / Chapter 3.1.3 --- Effects of ferric chloride --- p.78 / Chapter 3.1.4 --- Effects of ascorbic acid on the action of FAC --- p.81 / Chapter 3.2 --- "The acute, in vitro effect of extracellular iron on the membrane properties and excitability of hippocampal CA1 neurons" --- p.86 / Chapter 3.2.1 --- Membrane input resistance --- p.86 / Chapter 3.2.2 --- Voltage-Current relationship --- p.88 / Chapter 3.2.3 --- Membrane excitability --- p.90 / Chapter 3.2.3.1 --- Threshold current --- p.90 / Chapter 3.2.3.2 --- Action potential firing frequency --- p.92 / Chapter 3.2.4 --- Action potential characteristics --- p.95 / Chapter 3.2.4.1 --- "Action potential amplitude, area and width" --- p.95 / Chapter 3.2.4.2 --- Rise and decay kinetics of action potential --- p.98 / Chapter 3.3 --- The chronic effects of iron-loading in the brain on hippocampal long-term synaptic plasticity --- p.100 / Chapter 3.3.1 --- Validation of the iron-overload model --- p.100 / Chapter 3.3.1.1 --- Short-term (1 week) treatment --- p.100 / Chapter 3.3.1.2 --- Long-term (4 weeks) treatment --- p.103 / Chapter 3.3.2 --- Effects of chornic iron-overloading on LTP --- p.105 / Chapter 3.3.2.1 --- Short term iron treatment --- p.105 / Chapter 3.3.2.2 --- Long term iron treatment --- p.108 / Chapter 3.3.3 --- Oxidative stress measurement --- p.111 / Chapter 3.3.3.1 --- Protein oxidation --- p.111 / Chapter 3.3.3.2 --- Reactive oxidative species level --- p.116 / Chapter 4. --- DISCUSSION --- p.120 / Chapter 4.1 --- "Acute, in vitro effects" --- p.121 / Chapter 4.2 --- "Chronic, in vivo effects" --- p.125 / Chapter 5. --- REFERENCES --- p.134

The aim of this study was to assess the performance of the children in the study on some psychometric tests and to find out whether iron deficiency had any effect on cognitive skills as measured by the selected psychometric tests. The study also wanted to find out if there would be any gender differences on the psychometric tests. A sample of 810 children was selected from eleven schools from the rural Southern part of KwaZulu-Natal. The children were of ages eight to ten years old, were all Zulu speaking and in standard one. Blood samples were taken from all the children to determine iron levels. Psychometric tests viz., the Symbol Digit Modalities Test, Raven's Coloured Progressive Matrices, Rey's Auditory Verbal Learning Test and Young's Group Mathematics Test, were all administered to measure cognitive performance. The results showed no significant iron level effects on most of the measured cognitive skills. There were some significant gender effects on all the psychometric tests except for the Maths test. There was general low performance on all the psychometric tests. Therefore, the results highlighted the importance of designing more tests that can be standardized and thus be applicable to Zulu speaking children and other children with similar backgrounds. The tests should also be able to tap into the cognitive skills that may be affected by iron levels. There is also a great need for studies looking at the lower end of iron deficiency. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

A sustainable primary prevention strategy for infant iron deficiency anemia (IDA) was implemented and evaluated in a community with at-risk infants in northern Quebec, Canada. Communication strategies were used to promote iron-rich complementary food rather than iron-fortified formula, which can interfere with breastfeeding practice. This food-based approach has been successfully implemented in developing countries, but has not been applied in an industrialized country setting. / Mass media (i.e., radio dialogues, key messages, print material, point-of-purchase grocery store display) and interpersonal (i.e., homemade baby food cooking activity) communication strategies were developed in collaboration with community members and implemented in partnership with an existing community program. Reach and exposure of the strategies were measured using a questionnaire administered to a post-intervention sample (n = 45). Sales of promoted iron-rich infant food were examined pre- and post-intervention period. A repeat cross-sectional design was used for the impact evaluation. Two groups of mothers with infants, aged 7-10 months at Time 1 (n = 32) and Time 2 (n = 22) were interviewed. Outcome variables were infants' total iron and complementary food iron intakes measured by two 24-hour recalls. Secular trends in infants' hemoglobin values and milk type consumption were examined in the study community and two comparison communities. / Multiple communication channels increased awareness of IDA and influenced self-reported use of iron-rich infant food. Iron-rich infant food sales increased from pre- to post-intervention (p < 0.05). Complementary food intake iron increased between Time 1 (3.2 +/- 0.8 mg) and Time 2 (4.4 +/- 1.1 mg) (p < 0.05). The proportion of infants with anemia (hemoglobin < 110 g/L) significantly decreased from the period before (37.2%) to during (14.3%) the intervention (p < 0.05). No significant difference was found for this variable within the comparison communities. The proportion of infants receiving iron-fortified formula in the study community did not differ between Time 1 and Time 2, but increased from Time 1 (55%) to Time 2 (73%) (p < 0.05) in the comparison communities, indicating an erosion of breastfeeding practice. / These results suggest the effectiveness of communication strategies to improve infant iron nutrition in a community with good access to iron-rich infant food. The potential for this strategy in other communities warrants further investigation.

The objectives of this research were to determine the prevalence of anemia, and identify risk factors for anemia, in 9-month-old Cree infants living in northern Quebec. The prevalence of anemia (hemoglobin <110 g/L) was 25--32%, depending on the study sample. Iron deficiency was present in 28.2% of infants who could be classified and 14.4% had iron deficiency anemia. Fewer than 2% of infants had low birth weight (<2500 g) so most infants should have been born with adequate iron stores. One cause of anemia that was identified was a diet that was low in iron. Only 15.1% of infants were reported by guardians to eat meat daily and 28.5% were reported to never eat meat. Infants who were breastfed or cow's milk fed did not obtain sufficient iron for effective erythropoiesis. Compared with formula that was predominantly iron fortified, the odds ratio (OR) for anemia was 7.9 (95% CI 3.4--18.2) for breast milk and 5.0 (95% CI 2.0--12.7) for cow's milk. When milk type was controlled for, weight gain since birth was significantly associated with microcytic erythrocytes (OR comparing the highest tertile of weight gain to the lowest tertile 2.9, 95% CI 1.2--6.6). This indicates that fast-growing infants were not meeting their iron needs for growth. Another risk factor for anemia that was identified was common childhood infections. The prevalence of anemia among infants reported as recently unwell with an infection was higher than among infants reported as recently well (31.1% vs. 19.0%, chi2 = 4.27, p = 0.039). The prevalence of elevated blood lead was 2.7% and is not a major public health problem. No evidence for vitamin A deficiency was found. Serum retinol was positively associated with all iron status indicators. Cree infants who were given supplements containing vitamin A had a lower prevalence of anemia (hemoglobin <105 g/L) (10.8% vs 23.2%, chi2 = 5.97, p = 0.015). These results suggest a role for vitamin A in iron metabolism. To prevent anemia in aboriginal i

Zinc and manganese have long been considered as essential micronutrients to plant growth, yet the interactions of the two nutrients on growth and development of plants have not been elucidated in their entirety. Silicon is not classed as an essential element, but has been found to improve growth of a number of crops, particularly of the Poaceae family. A simple water culture hydroponic system was developed to monitor the growth and development of a fruit crop (Cucumber – Cucumis sativus) under deficient, adequate and excessive applications of zinc and manganese. Plant growth parameters were monitored including leaf growth, plant height, plant fresh and dry mass, yield, fruit size and fruit mass. Nutrient uptake was also measured using inductively coupled plasma emission spectroscopy, whilst chlorophyll was determined spectrophotometrically. Plant nutrient analyses were also conducted using inductively coupled plasma emission spectroscopy. Silicon was found to have a beneficial effect on the growth of cucumbers and was incorporated as a treatment for this crop along with zinc and manganese since foliar silicon sprays were able to correct the occurrence of mineral deficiency symptoms. Along with plant growth measurements, nutrient uptake, plant nutrient analysis and chlorophyll determination, plant tissue was also analysed using transmission electron microscopy to establish the impact of silicon applications on the cell ultra-structure of cucumbers. Electron micrographs showed an increased presence of plasmodesmata in treatments excluding silicon. Such increased plasmodesmata connections under silicon deficient conditions could increase translocation of cell solutes due to reduced cell longevity. Results also confirmed the essentiality of zinc and manganese on plant growth and development as typical deficiency symptoms were observed. Typical toxicity symptoms were also recorded. Rates of uptake of nutrients corresponded with leaf growth and enlargement as well as yield. The chlorophyll concentration was not a clear indicator of nutrient application level. Typically, manganese and zinc interacted with iron, magnesium, calcium and potassium, affecting their uptake into the plant dependent on the level of manganese and zinc applied. Although non-essential, silicon improved plant growth, but had neither a relationship with the other nutrients evaluated nor affected the physical growth and development of the plants. Manganese and zinc, as essential to plant growth and development, affect the visual appearance of the plant as well as affect the plant biochemically due to their involvement in many growth and development processes. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.