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Youth as an asset fordairy development : What have we learned from youth-led dairy initiatives in East Africa?
No full textOver the last decade, several initiatives have focused on supporting youth employment in the African dairy sector. Some with success, some without. What can we learn from these initiatives? What were the challenges encountered? What have been successful strategies to increase youth involvement in the dairy sector? Work-ing with youth groups, mainstreaming entrepreneurial skills, digitisation and establishing strong links with cooperatives have shown to be effective to engage youth in this prospective sector
Heterogeneous anion exchange membranes with nitrate selectivity and low electrical resistance
No full textSelective transport of specific ions across ion-exchange membranes can be enhanced by controlling membrane properties such as hydrophobicity. Previous studies have shown that hydrophobic membranes enhance transport of ions with low hydration energy, although such membranes often have increased electrical resistance. In the present work, we study the separation of monovalent ions, specifically nitrate and chloride, using newly-designed heterogeneous anion-exchange membranes. These membranes show high selectivity for nitrate over chloride and have low electrical resistance. We use a functionalized polymeric binder (ionomer) and three ion-exchange resins with different hydrophobic groups, i.e., resins with quaternary ammonium groups and methyl, ethyl, and propyl substituents, respectively. We find that in electrolyte solutions with nitrate and chloride, nitrate over chloride selectivity in our membranes increases with increasing length of the alkyl groups. The membrane with propyl groups, i.e., which has the highest selectivity for nitrate, was further tested in electrolyte solutions containing nitrate, chloride, sulfate, and nitrate, chloride, iodate. The transport of sulfate and iodate ions across the membrane with propyl groups was 6% and 2% of the total counterions transport, respectively. For monovalent ions with similar hydrated size it is possible to report selectivity trends based on the ion hydration energy. We find that the chemical structure of the membrane can either promote or hinder the transport of ionic species.</p
Screening for electrical conductivity in anaerobic granular sludge from full-scale wastewater treatment reactors
No full textGranulation in bioreactors for the treatment of industrial wastewater is a common phenomenon. Anaerobic granular sludge grown on brewery wastewater is known to manifest electrical conductivity, a characteristic that previously has been related to direct interspecies electron transfer. To assess if this characteristic is more widespread, we determined the electrical conductivity of 28 anaerobic granular sludges grown on a wide variety of industrial wastewaters in full-scale reactors. This revealed that it is a highly variable characteristic: one sludge had a conductivity of 171 μS cm-1 which is 4 times higher than the maximum reported for industrial anaerobic granules, 5 sludges had moderate conductivity ranging from 9.6 to 39 μS cm-1, while the conductivity of the remaining 22 sludges was below 4.5 μS cm-1. Additionally, we studied the possible relation between electrical conductivity and biological, chemical and physical properties of the granules. No clear relationship was found between electrical conductivity and microbial composition, while a positive correlation was found with both the iron and sulfur content. Other correlations were not found. Results suggest that electrical conductivity is a fairly rare characteristic of anaerobic granular sludge. The factors triggering its occurrence, as well as its significance, are not well understood yet.</p
CRISPR/Cas9 Gene Editing of Gluten in Wheat to Reduce Gluten Content and Exposure—Reviewing Methods to Screen for Coeliac Safety
No full textIngestion of gluten proteins (gliadins and glutenins) from wheat, barley and rye can cause coeliac disease (CD) in genetically predisposed individuals. The only remedy is a strict and lifelong gluten-free diet. There is a growing desire for coeliac-safe, whole-grain wheat-based products, as consumption of whole-grain foods reduces the risk of chronic diseases. However, due to the large number of gluten genes and the complexity of the wheat genome, wheat that is coeliac-safe but retains baking quality cannot be produced by conventional breeding alone. CD is triggered by immunogenic epitopes, notably those present in α-, γ-, and ω-gliadins. RNA interference (RNAi) silencing has been used to down-regulate gliadin families. Recently, targeted gene editing using CRISPR/Cas9 has been applied to gliadins. These methods produce offspring with silenced, deleted, and/or edited gliadins, that overall may reduce the exposure of patients to CD epitopes. Here we review methods to efficiently screen and select the lines from gliadin gene editing programs for CD epitopes at the DNA and protein level, for baking quality, and ultimately in clinical trials. The application of gene editing for the production of coeliac-safe wheat is further considered within the context of food production and in view of current national and international regulatory frameworks
Chemical vegetable safety in China: “supermarketisation” and its limits
No full textPurposeThe purpose of this paper is to analyze the process of supermarketization in the vegetable retail sector in China and its impact on food safety. Design/methodology/approachData from food safety reports by the Chinese Food and Drug Administration (CFDA) are used to investigate the degree of vegetable safety in different value chain types. To assess the predictors of the degree of vegetable safety, a logistic regression model is applied. FindingsSupermarketization has led to the reorganization of the vegetables provision system, through closer coordination along the supply chain and the use of secured production bases. We identify four types of vegetable value chains in China based on their form of coordination. Supermarkets improve vegetable safety even when they rely on external suppliers, but also wet markets perform significantly better than other small-scale retailers in terms of vegetable safety. Originality/valueThe study has expanded the knowledge of the supermarketization in urban China by collecting data from CFDA. Furthermore, the study used the theory of food value chain to understand determinant factors in securing food safety. Moreover, this study reveals that wet markets also have prospects in solving vegetable safety problems in China, especially in underdeveloped areas.<br/
Aanpak bestrijdingsmiddelen in het grondwater van het Maasstroomgebied : Oorzakenanalyse en verkenning van maatregelen
No full textIn het grondwater in het Maasstroomgebied zijn twintig stoffen gevonden in meer dan 2% van de monsters. Negen zijn relevant voor een oorzakenanalyse en een discussie over maatregelen. Voor een aantal meetpunten zijn er aanwijzingen dat het grondwater wordt beïnvloed door infiltrerend Maaswater. Voor de onderzochte stoffen zijn de aannemelijkste oorzaken van het aantreffen in grondwater het gebruik in de aardappelteelt, maisteelt en suikerbietenteelt. Voor regionale partijen zijn activiteiten op het gebied van kennisoverdracht en begeleiding van gebruikers belangrijke maatregelen die kunnen bijdragen aan het verminderen van de emissie. Het verdient aanbeveling om deze projecten te monitoren op het effect
Entropy estimates of a hard sphere system by data compression of Monte Carlo simulation data
No full textData compression algorithms remove redundant information from a file. The extent to which a file size is reduced is a measure of the entropy. Recently, it has been suggested to use this technique to find the entropy from a simulation of a physical system. Here, we apply this technique to estimate the entropy from Monte Carlo simulations of the hard sphere system. Numerical results compare well with the limited available entropy estimates from the laborious thermodynamic integration method, while this new algorithm is much faster. Our results show the phase transition by calculation of the entropy for a large number of densities. A common tangent method is used to find the coexistence densities for the fluid-solid phase transition. The upper density deviates from the established density from the literature, while the lower density compares very well.</p