Food Science Commons^™

Hiv And Nutrition: Pregnant And Lactating Women, Peggy Papathakis, Nigel Rollins

Food Science and Nutrition

No abstract provided.

Learning To Teach, Teaching To Learn, Lisa Nicholson, Susan Algert, Rachael Willey

Food Science and Nutrition

Community Based Learning (CBL) successfully enhances didactic objectives in a nutrition curriculum while serving the community. University students actively solved problems in a 'real world' situation and benefited non-profit locations. Emotionally, learners profited on personal levels through successfully overcoming barriers. Content analysis was used to demonstrate that using CBL in a 'Nutrition Education and Communication' class met didactic learning objectives, enhanced students' personal confidence in teaching, and strengthened awareness of interpersonal skills. 71 students, in pairs, developed and taught nutrition lessons in diverse community locations. Students kept a reflective journal throughout the five weeks of the experience.

Are Who/Unaids/Unicef-Recommended Replacement Milks For Infants Of Hiv-Infected Mothers Appropriate In The South African Context?, Peggy Papathakis, Nigel Rollins

Food Science and Nutrition

ObjectiveLittle is known about the nutritional adequacy and feasibility of breastmilk replacement options recommended by WHO/ UNAIDS/UNICEF. The study aim was to explore suitability of the 2001 feeding recommendations for infants of HIV-infected mothers for a rural region in KwaZulu Natal, South Africa specifically with respect to adequacy of micronutrients and essential fatty acids, cost, and preparation times of replacement milks.

Methods Nutritional adequacy, cost, and preparation time of home-prepared replacement milks containing powdered full cream milk (PM) and fresh full cream milk (FM) and different micronutrient supplements (2 g UNICEF micronutrient sachet, government supplement routinely available in district …

Micronesia: Steps In The Right Direction, Aydin Nazmi

Food Science and Nutrition

As I watch the hazy orange sun sink into the still blue sea overlooking Chuuk lagoon, I marked the end of another seemingly ordinary day in the Federated States of Micronesia. But this October day was special—it marked the beginning of a promising new era in Chuuk’s fight against HIV and AIDS. For the past few months, several proceedings had set into motion a cascade of events that would ultimately (hopefully) benefit and educate the people of Chuuk state.

Interaction Of Blood Pressure And Ldl Cholesterol In Early Atherosclerosis. The Los Angeles Atherosclerosis Study, Ping Sun, Kathleen M. Dwyer, Noel Bairey Merz, Wei Sun, Lisa M. Nicholson, Cheryl Nordstrom, James H. Dwyer

Food Science and Nutrition

Background. The response to injury model of atherosclerosis has been investigated in animal models but not in epidemiologic studies. Relations between LDL cholesterol and carotid intima-media thickness (IMT) within levels of SBP provide a test of this model. Methods. Data are from a longitudinal study of 573 randomly sampled asymptomatic employees of a large company aged 40-60 years. IMT and change in IMT over 18 months (8IMT) were determined sonographically in the common carotid artery. 497 subjects were available for cross-sectional analysis. To investigate interactive effects of SBP and serum LDL on IMT, linear slopes (j±SE in mm/mmol/L) of IMT …

Forms Of Cadmium In Sandy Soils After Amendment With Soils Of Higher Fixing Capacity, S. S. Mann, G. S. P. Ritchie

Food Science and Nutrition

Most of the Cd applied through phosphatic fertilizers in sandy soils tends to stay in mobile forms (soluble or exchangeable) and hence the risk of it leaching to underground water or its uptake by plants is higher. A sequential extraction procedure was used to assess the efficacy of amending materials (soils containing inorganic or organic adsorption components) on the re-distribution of forms of Cd in a sandy soil. Amendment of the sandy soil with each of the three soils (yellow earth, lateritic podzolic and peaty sand) was generally effective in altering the more mobile or available forms of Cd to …

Effect Of Gypsum Application Rate And Leaching Regime On Wheat Growth In A Highly Acidic Subsoil, C. D.A. Mclay, G. S. P. Ritchie

Food Science and Nutrition

A glasshouse experiment "was conducted to investigate gypsum application and leaching on the amelioration of" an aluminium (Al) toxic subsoil for wheat growth. Treatments included different rates of gypsum application and amount of leaching prior to wheat being grown. Wheat shoot growth increased when gypsum was applied in both the presence and absence of leaching, but growth was higher with leaching. Gypsum application led to a decrease in toxic Al as a result of a higher ionic strength and activity of AlSO₄⁺ion pairs in the soil solution, and increased Al leached from the soil. Root growth may …

Soluble Aluminium In Acidic Soils: Principles And Practicalities, G. S.P. Ritchie

Food Science and Nutrition

Our ability to predict toxic quantities of aluminium (Al) in acidic soils is limited by our understanding of the interactions between different solid forms of Al in solution and our lack of knowledge of which form control soluble Al. This review briefly considers each type of solid form of Al, particularly from a kinetic point of view and discusses models that have been developed to predict release of Al from individual forms. More comprehensive models (i.e. more than one source or sink of Al) are then discussed as well as the interactions between different solid sources of Al.

Amelioration Of Subsurface Acidity In Sandy Soils In Low Rainfall Regions. I. Responses Of Wheat And Lupins To Surface-Applied Gypsum And Lime, C. D. A. Mclay, G. S.P. Ritchie, W. M. Porter

Food Science and Nutrition

Amelioration of subsoil acidity using gypsum (CaSO₄·2H₂O) or lime (CaCO₃) was studied on sandy textured soils with low water holding capacity in a low rainfall environment. Field trials were established in 1989 at two sites on yellow sandplain soils to investigate whether different rates, sources and combinations of gypsum and lime application could be used to increase wheat and lupin yields. Gypsum increased wheat yields by up to 45% in the first two growing seasons whereas lime increased wheat yields by up to only 15% in the second season. The highest yields were generally …

Role Of Dissolution And Precipitation Of Minerals In Controlling Soluble Aluminum In Acidic Soils, G. S. P. Ritchie

Food Science and Nutrition

No abstract provided.

Nutrient Uptake And Organic Acid Anion Metabolism In Lupins And Peas Supplied With Nitrate, S. P. Loss, A. D. Robson, G. S.P. Ritchie

Food Science and Nutrition

Unlike many plants reported in the literature, lupins do not excrete OH− in amounts equivalent to the net excess of inorganic anion uptake over inorganic cation uptake. To investigate the mechanisms involved in the maintenance of charge balance, nutrient uptake and organic anion accumulation of lupins and peas supplied with a range of NO3− concentrations, were compared. Lupins absorbed less NO3− than peas on a dry weight basis, which largely ACCOUNTED for the smaller excess of anion uptake over cation uptake in lupins than in peas at the same NO3− supply. When anion uptake exceeded cation uptake, peas excreted an …

Changes In The Forms Of Cadmium With Time In Some Western Australian Soils, S. S. Mann, G. S.P. Ritchie

Food Science and Nutrition

Changes in the forms of Cd with time could affect its uptake by plants and hence potential toxicity to animals and humans. The effect of time on the forms of native and added Cd was studied in four West Australian soils which differed in their clay, hydrous oxide and organic matter content. Sequential extraction of soluble (KCl), exchangeable (BaCl₂), bound to organic matter (NaOCl), bound to oxides/clays (ammonium oxalate) and residual (concentrated acids) forms of Cd was carried out at different time intervals after the addition of Cd.
The Cd that was added to the soils transformed with …

Phosphorus Leaching In Soils Amended With Piggery Effluent Or Lime Residues From Effluent Treatment, D. M. Weaver, G. S.P. Ritchie

Food Science and Nutrition

Phosphorus (P) in wastes from piggeries may contribute to the eutrophication of waterways if not disposed of appropriately. Phosphorus leaching, from three soils with different P sorption characteristics (two with low P retention and one with moderate P retention) when treated with piggery effluent (with or without struvite), was investigated using batch and leaching experiments. The leaching of P retained in soil from the application of struvite effluent was determined. In addition, P leaching from lime residues (resulting from the treatment of piggery effluent with lime to remove P) was determined in comparison to superphosphate when applied to the same …

Phosphorus Removal From Piggery Effluents Of Varying Quality Using Lime And Physico-Chemical Treatment Methods., D. M. Weaver, G. S. P. Ritchie

Food Science and Nutrition

The choice of management practices for the treatment of piggery effluent prior to its disposal to waterways or land is governed by the desire to simultaneously minimise the cost of treatment whilst minimising pollution of the environment. Laboratory experiments were conducted to compare the removal of total and total filterable phosphorus (P) (μm) from ortho-phosphate solutions or piggery effluent by hydrated lime or lime kiln dust alone, or from recycled piggery effluent by lime and physico-chemical treatment methods. In addition, the ability of lime to remove P from recycled piggery effluent at an intensive piggery was assessed.

Most P …

Amelioration Of Subsurface Acidity In Sandy Soils In Low Rainfall Regions. Ii. Changes To Soil Solution Composition Following The Surface Application Of Gypsum And Lime, C. D. A. Mclay, G. S.P. Ritchie, W. M. Porter, A. Cruse

Food Science and Nutrition

Two field trials were sampled to investigate the changes to soil solution chemical properties of a yellow sand plain soil with an acidic subsoil following the application of gypsum and lime to the soil surface in 1989. The soils were sandy textured and located in a region of low annual rainfall (300-350 mm). Soil was sampled annually to a depth of 1 m and changes in soil solution composition were estimated by extraction of the soil with 0.005 M KCl.
Gypsum leaching caused calcium (Ca), sulfate (SO₄) and the ionic strength to increase substantially in both topsoil and …

Temporal Variation In Potassium Chloride Extractable Aluminum, Sodium, And Soil Ph, And The Effects On Interpretation Of Subsoil Aluminum Toxicity In Yellow Earths, S. J. Carr, G. S.P. Ritchie

Food Science and Nutrition

Temporal variation in two soil tests ([Al] and the ratio [Al]:[Na] in 1:5 0.005M KCl extract) and pH were evaluated on six occasions during a twelve month study of eleven yellow earths in the Merredin region (31°5, 118°E) of Western Australia. The [Al] and ratio [Al]:[Na] in 1:5 0.005M KCl extracts are useful soil tests capable of distinguishing between productive and non-productive (Al toxic) yellow earths in Western Australia. The aim of the study was to determine the most appropriate time to sample yellow earths, in order to predict accurately which soils contained concentrations of Al in the 15-25 cm …

Zinc Adsorption By Sterilized And Non-Sterilized Soil In The Presence Of Citrate And Catechol, P. Chairidchai, G. S.P. Ritchie

Food Science and Nutrition

The effect of organic ligands on zinc (Zn) adsorption in the rhizosphere may be influenced by microbial activity depleting the concentration of the ligand over time. Zinc adsorption by sterile and non-sterile lateritic soil was measured by shaking the soils with Zn solutions at a soil-liquid ratio of 1: 5 for five periods of time ranging from 17-480 h. The concentrations of Zn and the ligands were determined after the selected times. The speciation of Zn was then estimated. Changes in Zn adsorption with time in the presence of organic ligands were due to changes in pH and Zn complexation …

Effect Of Lupins And Pasture On Soil Acidification And Fertility In Western Australia, S. P. Loss, G. S.P. Ritchie, A. D. Robson

Food Science and Nutrition

An 'across the fence' comparison of farmer paddocks with nearby virgin bush sites was made at 3 locations, to measure the effects of lupins and subterranean clover based pastures on the chemical properties of the soil. Estimated rates of acidification in the 0-60 cm depth were 0.29-0.55 kmol H+/ha.year for wheat-lupin paddocks and 0.16-0.2 1 kmol H+/ha .year for pasture paddocks. A significant proportion of this acidification occurred below 20 cm, particularly in the lupin paddocks (up to 70% of the total). Severe water repellency had developed at 1 location that had produced 30 lupin crops with the occasional wheat …

The Effect Of Citrate And Ph On Zinc Uptake By Wheat, P. Chairidchai, G. S. P. Ritchie

Food Science and Nutrition

Zinc uptake by plants may be influenced by its reaction with organic ligands in the rhizosphere. Therefore, four experiments were conducted to examine the effects of an organic ligand (citrate) and pH on the uptake of Zn by wheat (Triticum aestivum L. emend. Thell). Plants were grown for 21 to 28 d in a nutrient solution (containing 0-0.05 µmol L^-1 Zn) in a temperature controlled tank, either in the absence or presence of citrate and at constant or variable pH (3.7-7.1). Dry matter weights of plant parts and Zn content in the shoots were determined. The activities of Zn …

Effect Of Gypsum And Lime On Wheat Growth In Pots Containing An Acidic Subsoil, C. D.A. Mclay, G. S. P. Ritchie

Food Science and Nutrition

A pot experiment was conducted to establish whether gypsum or lime could increase wheat growth in an acid subsoil. Wheat (Triticum aestivum c. v. Gutha) was grown in 3 kg of soil which had been mixed with basal nutrients and different rates of gypsum and lime. Wheat in the treatment which received no gypsum or lime showed the most severe nutrient deficiency symptoms and had the lowest shoot and root dry weights. Lime treatments increased shoot and root growth 2 to 3 fold and decreased the concentration of total Al and the calculated activities of all Al species. Gypsum increased …

The Influence Of Ph On The Forms Of Cadmium In Four West Australian Soils, S. S. Mann, G. S.P. Ritchie

Food Science and Nutrition

The forms of cadmium in soils affect its uptake by plants and hence its potential toxicity to animals and humans. We studied the effect of pH on the forms of native and added Cd in four West Australian soils which differed in their clay, hydrous oxide and organic matter content. The forms of Cd were extracted sequentially by KCl, BaCl₂, NaOCl, ammonium oxalate and concentrated acids.
The majority of Cd applied to a sandy soil was found in the soluble (KCl) and the exchangeable (BaCl₂) forms at all pH values. In the siliceous sand, the proportion …

Phosphorus Retention And Release From Sandy Soils Of The Peel-Harvey Catchment, G. S.P. Ritchie, D. M. Weaver

Food Science and Nutrition

In order to manage phosphorus (P) losses from soils to waterbodies, knowledge of the mechanisms through which P is retained or released from the soil is essential. Sandy soils of the Peel-Harvey catchment (Western Australia) were subjected to a range of environmental and management factors in the laboratory and field in order to gain an understanding of the mechanisms that affect the magnitude of P losses. Sandy soils accumulated P, despite having little sorption capacity, and this accumulation could be monitored by measuring an acid-extractable fraction. The potential, short-term P loss could be estimated by determination of water-soluble soil solution …

Al Toxicity Of Wheat Grown In Acidic Subsoils In Relation To Soil Solution Properties And Exchangeable Cations, S. J. Carr, G. S.P. Ritchie

Food Science and Nutrition

Toxic concentrations of soluble A1 in the subsoil decrease the yield of wheat grown on many yellow earths in the eastern wheatbelt of Western Australia. In our previous research (Carr et al. 1991), we observed variable plant response to high concentrations of soluble Al in subsoils of yellow earths in different regions of the wheatbelt. Environmental conditions (e.g. water supply) and/or an unidentified soil mitigating factor may have contributed to the variable plant response to soluble Al in some of the regions studied.
We collected ten soils from four regions of the eastern wheatbelt of Western Australia. In a glasshouse …

The Long-Term Fate Of Copper Fertilizer Applied To A Lateritic Sandy Soil In Western Australia, R. G. Mclaren, G. S.P. Ritchie

Food Science and Nutrition

A soil copper fractionation was carried out on soils sampled from plots in a long-term copper fertilizer trial on a lateritic sandy soil in Western Australia. At copper application rates up to 8.25 kg copper sulphate ha^-1, a high proportion of the applied copper was initially associated with the soil organic matter. During the course of the trial (20 years), a substantial proportion of this copper became redistributed to a residual soil fraction, i.e. the residue remaining after extractions to remove organic matter and iron oxides. However, significant redistribution of copper with time was not detected in plots …

H+/Oh- Excretion And Nutrient Uptake In Upper And Lower Parts Of Lupin (Lupinus Angustifolius L.) Root Systems, S. P. Loss, A. D. Robson, G. S.P. Ritchie

Food Science and Nutrition

The cultivation of narrow-leafed lupins (Lupinus angustifolius L.) increase rates of subsoil acidification, and this is thought to be partly related to their pattern of nutrient uptake and H⁺/OH^- excretion. The main hypothesis of this study was that H⁺ and OH^- excretion is not distributed evenly over the entire length of the root system but is limited to zones where excess cation or anion uptake occur. Seedlings of nodulated lupins were grown in solution culture using vertically split pots that allowed the upper and lower zones of the root system to be supplied with …

Phosphorus Sorption By Gravels In Lateritic Soils, D. M. Weaver, G. S.P. Ritchie, R. J. Gilkes

Food Science and Nutrition

The effect of sesquioxidic gravels (>2 mm size fraction) on phosphorus sorption by two gravelly lateritic soils was investigated by phosphorus sorption experiments, X-ray diffraction, autoradiography and electron microscopy.In one soil the abundance and size of gravels decreased downslope. As the gravel content of both soils increased (13-61%), the proportion of large (>8 mm) gravels increased (0-70%). Phosphorus sorption increased in the order: (>2 mm fraction) < (whole soils) < (2 mm) decreased with increasing gravel size and increased with increasing time. Phosphorus sorption by whole soils decreased with increasing gravel content. Phosphorus sorption by the >2 mm fraction was principally by the external surfaces of the gravels. The estimation of phosphorus application rates for lateritic soils depended on the amount of phosphorus required by the plant …

Soil Tests For Aluminum Toxicity In The Presence Of Organic Matter: Laboratory Development And Assessment, M. G. Whitten, G. S.P. Ritchie

Food Science and Nutrition

Al toxicity in plants is related to the activity of Al³⁺ and Al-hydroxy monomers in the soil solution, whereas Al complexed with ligands such as fluoride (F), sulphate (SO₄^2-), and oxalate is not toxic. Estimation of toxic Al relies on measurement of “labile”; Al after short contact times with colorimetric reagents or cation-exchange resins. However, shifts in equilibrium may result in non-toxic forms of Al reacting with the complexing agent or resin.

A series of laboratory experiments tested the degree to which labile Al is related to Al³⁺ in simplified media and compared methods of …

Calcium Chloride Extractable Cadmium As An Estimate Of Cadmium Uptake By Subterranean Clover, M. G. Whitten, G. S.P. Ritchie

Food Science and Nutrition

Cadmium (Cd) may accumulate in soils which have been regularly fertilized with phosphate fertilizers which contain Cd originating in rock phosphate. Soil was taken from three sites in the wheatbelt of Western Australia which were estimated to have received different amounts of phosphate fertilizer over the past decade. The pH was adjusted with dilute HCl or CaCO₃. No Cd was added experimentally. The concentration of Cd in the whole tops of Trifolium subterraneum cv Mt Barker grown in a glasshouse pot experiment increased from 0.2-0.8 µg g^-1 dry wt at pH 6.6-6.9 (1:5 0.01 M CaCl …

A Comparison Of Soil Tests To Predict The Growth And Nodulation Of Subterranean Clover In Aluminium-Toxic Topsoils, M. G. Whitten, G. S.P. Ritchie

Food Science and Nutrition

Total Al concentration or pH in 1∶5 10 mM CaCl₂ extracts and exchangeable Al in 100 mM BaCl₂ extracts cannot always distinguish between Al-toxic and Al-nontoxic topsoils. Our objectives were to compare the abilities of different measures of Al and pH in various extracts to predict the effects of acidity on growth and nodulation of subterranean clover. In a glasshouse experiment, Trifolium subterraneum L. cv. Mt Barker was grown in acidic soils from 3 sites in the Western Australian wheatbelt with different histories of phosphate fertilizer application. The pH was adjusted to give a range of …

A Soil Test For Aluminium Toxicity In Acidic Subsoils Of Yellow Earths In Western Australia, S. J. Carr, G. S.P. Ritchie, W. M. Porter

Food Science and Nutrition

Many of the yellow earths in the Western Australian wheatbelt have naturally acidic subsoils which can reduce the yield of wheat grown on them. Current methods of assessing soil acidity cannot identify which soils have subsoil acidity severe enough to restrict wheat yields.

We conducted 53 field experiments at 34 sites in 5 regions over 3 years to determine the relationship between yield of wheat and several different indices for identifying subsoils with toxic concentrations of aluminium, Al. Initially, we identified that the concentration of aluminium, [Al], in the soil solution and in 1 : 5 0.005 M KCl extracts …