The impact of smallholder commercialisation of organic crops on food consumption patterns, dietary diversity and consumption elasticities

The impact of smallholder commercialisation on food consumption patterns in a rural community of South Africa was investigated. The dietary diversity, nutrient intakes and consumption patterns of certified, partially certified and non-members of an organic farmers’ organisation were compared. Engagement in certified commercial organic farming promoted comparatively greater dietary diversity and improved nutrient intakes. While smallholder agriculture commercialisation has the potential to improve food consumption patterns and food quality through increased income and labour opportunities, caution should be exercised before claiming that such commercialisation can alleviate food insecurity and solve hunger in rural South Africa.agriculture, growth, smallholder, consumption, nutrition, Food Security and Poverty,

The Impact of Small Holder Commercialisation of Organic Crops on Food Consumption Patterns in KwaZulu-Natal, South Africa

The impact of smallholder commercialisation on food consumption patterns in a rural community of South Africa was investigated. The consumption patterns, dietary diversity and nutrient intakes of certified and partially certified members of an organic farmers' organisation were compared to data from a random sample of non-member households. Two consecutive survey rounds (n = 200) conducted in November 2004 and March 2005 enabled comparison of dietary diversity, nutrient adequacy (in terms of per household adult female equivalents for energy, iron, and vitamin A) and expenditure elasticities between seasons. Households with members engaged in certified comm ercial organic farming enjoyed greater dietary diversity, improved nutrient intakes com pared to households with members in conversion to organic production and households not engaged in commercial organic farming. Farm and non-farm income strongly and positively influenced nutritional adequacy for households of partially certified and certified members of the organisation. Marked differences in expenditure elasticities were found between the three groups. The results suggested that commercialisation of small holder agriculture has potential to improve food consumption patterns and food quality directly through income generated and indirectly through increased labour opportunities that result in wages and inkind food transfers. While commerciali sation of small holder agriculture shows potential for improving nutrition, caution should be exercised before claiming that such commercialisation can alleviate food insecurity and solve hunger in South Africa.food consumption, nutrition, farm households, small holder, Food Consumption/Nutrition/Food Safety, D1, Q12,

Quantification of carboxyl groups in carbodiimide cross-linked collagen sponges

Glutaraldehyde (GA) fixation of bioprosthetic tissue is a well adapted technique, with commercial products on the market for almost 40 years. Amine groups present in tissue react with GA to form different types of cross-links. An estimation of the degree of cross-linking of the tissue can be obtained by measuring the concentration of residual amine groups, which is frequently carried out with the 2,4,6 trinitrobenzene sulphonic acid (TNBS) assay. Cross-linked tissue and collagen matrices are usually further characterized by determining their physical properties (such as the shrinkage temperature), biological properties (such as resistance to enzymatic degradation), and mechanical properties before in vivo evaluation takes place. In an effort to improve the properties of cross-linked tissue and collagen, alternative cross-linking methods have been developed. One of these methods is based on the use of water soluble carbodiimides (CDI). It is generally accepted that this cross-linking method leads only to the formation of amide linkages between tissue carboxyl and amine groups. Therefore, until recently the TNBS assay was also used to determine the degree of cross-linking of CDI cross-linked tissue and collagen. However, it cannot be excluded that after activation of carboxyl groups of tissue and collagen by CDI, these groups can react with other nucleophiles (like hydroxyl groups) present in the matrix. To obtain a better insight in the degree of cross-linking of CDI cross-linked matrices a reliable assay for quantification of residual carboxyl groups is required. Up to now such an assay was not available. In this study a new assay to determine residual carboxyl groups in CDI cross-linked collagen matrices is presented. Reconstituted dermal bovine collagen matrices (RDBC) were cross-linked with a water soluble CDI and N-hydroxysuccinimide (NHS) and residual carboxyl groups were labeled using 5-bromomethyl fluorescein. Subsequently, the fluorescent label was released by mild hydrolysis and quantified with capillary zone electrophoresis. A calibration curve relating the concentration of carboxyl groups with peak intensities was obtained using SephadexTM standards with known concentrations of carboxyl groups. The concentration of carboxyl groups in unprocessed RDBC as determined with this new technique was equal to the concentration of carboxyl groups measured by amino acid analysis. On the basis of the concentration of residual carboxyl groups determined for CDI/NHS cross-linked RDBC and RDBC, in which the amine groups were blocked with propionaldehyde before CDI/NHS cross-linking, it was concluded that activated carboxyl groups can also react with other groups (such as hydroxyl groups) present in the matrix. This implies that the crosslink density of RDBC matrices after treatment with CDI/NHS is higher than expected on the basis of amide bond formation only, as determined by the TNBS assay

Three-dimensional morphology and gene expression in the Drosophila blastoderm at cellular resolution II: dynamics.

BackgroundTo accurately describe gene expression and computationally model animal transcriptional networks, it is essential to determine the changing locations of cells in developing embryos.ResultsUsing automated image analysis methods, we provide the first quantitative description of temporal changes in morphology and gene expression at cellular resolution in whole embryos, using the Drosophila blastoderm as a model. Analyses based on both fixed and live embryos reveal complex, previously undetected three-dimensional changes in nuclear density patterns caused by nuclear movements prior to gastrulation. Gene expression patterns move, in part, with these changes in morphology, but additional spatial shifts in expression patterns are also seen, supporting a previously proposed model of pattern dynamics based on the induction and inhibition of gene expression. We show that mutations that disrupt either the anterior/posterior (a/p) or the dorsal/ventral (d/v) transcriptional cascades alter morphology and gene expression along both the a/p and d/v axes in a way suggesting that these two patterning systems interact via both transcriptional and morphological mechanisms.ConclusionOur work establishes a new strategy for measuring temporal changes in the locations of cells and gene expression patterns that uses fixed cell material and computational modeling. It also provides a coordinate framework for the blastoderm embryo that will allow increasingly accurate spatio-temporal modeling of both the transcriptional control network and morphogenesis

Constraints and Affordances of Online Engagement With Scientific Information—A Literature Review

Many urgent problems that societies currently face—from climate change to a global pandemic—require citizens to engage with scientific information as members of democratic societies as well as to solve problems in their personal lives. Most often, to solve their epistemic aims (aims directed at achieving knowledge and understanding) regarding such socio-scientific issues, individuals search for information online, where there exists a multitude of possibly relevant and highly interconnected sources of different perspectives, sometimes providing conflicting information. The paper provides a review of the literature aimed at identifying (a) constraints and affordances that scientific knowledge and the online information environment entail and (b) individuals\u27 cognitive and motivational processes that have been found to hinder, or conversely, support practices of engagement (such as critical information evaluation or two-sided dialogue). Doing this, a conceptual framework for understanding and fostering what we call online engagement with scientific information is introduced, which is conceived as consisting of individual engagement (engaging on one\u27s own in the search, selection, evaluation, and integration of information) and dialogic engagement (engaging in discourse with others to interpret, articulate and critically examine scientific information). In turn, this paper identifies individual and contextual conditions for individuals\u27 goal-directed and effortful online engagement with scientific information

Do food quality and food quantity talk the same? Lesson from household food security study in Embo, South Africa

OBJECTIVES :Relating food diversity, quality, and intake is one of the key aspects in understanding household food security. This paper aimed at marying food intake and quality, both being measurement for food security. METHODS : A household food consumption survey (n = 200) exploring food diversity, quality of foods, and their relation to food intake in Embo, a poor farming community in rural KwaZulu-Natal was carried out in November 2004 (period of insufficiency) and repeated in March 2005 (period of plenty). Household food intake strata were developed using matrices obtained from the Household Food Intake Index and nutritional adequacy ratios. Food quality was measured using food count and later using 5 food groups, namely, starches, vegetables and fruits,animal sourced foods, fats, and legumes. RESULTS: Single food count showed dietary diversity to be significantly different across households with different food intake during the period of plenty (P ≤ 0.000). During the period of plenty, vegetable and fruits contributed significantly different proportions of energy (P ≤ 0.000), protein (P ≤ 0.006), iron (P ≤ 0.020), and vitamin E (P ≤ 0.006) to household food intake strata. Intake of vitamin A was more elastic as its intake variation from legumes, fats, and animal sourced foods was (P ≤ 0.000), from starches (P ≤ 0.008) and from vegetable and fruits (P ≤ 0.064) during the second round. Starches are the most important food group to the community, whereas fats and animal sourced food groups are less important. CONCLUSIONS : The current study has been able to include food quality in food security studies. Seasonality accounts for variation in food quality. The South African food-based dietary guidelines are relevant to the Embo community.The South African National Research Foundation (project no. TTK2007052000011) and Ford Foundation, South Africa (Grant no. 1035-1796).http://www.tandfonline.com/loi/uacn20hb201