998 research outputs found

    Selected Economic Implications and Policy Aspects of Agricultural Biotechnology

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    The paper provides an overview of the types of economic costs, benefits, and risks involved with agricultural biotechnology at the farm level, at the market level, and for the farm and food system as a whole. Both advantages and disadvantages of agricultural biotechnology are discussed. Among the drivers of the US domestic and international consumer demand for transgenic crop products discussed in the paper are environmental and food safety concerns. A comparison is made between a \u27science-based\u27 regulatory framework and a policy based on the precautionary principle. The authors argue that open dialogue is needed for achieving improved public understanding of agricultural biotechnology, and that analyses need to go beyond discussing the scientific merits of biotechnology, to include social scientists, as well as the public at large

    Side effects by oral application of atmospheric pressure plasma on the mucosa in mice

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    Cold atmospheric pressure plasma (CAP) has been investigated with promising results for peri-implant diseases treatment. However, prior to in-vivo applications of CAP sources in humans, short-term harmful mucosal damage or other unwanted side effects have to be reviewed. 180 male mice (B6C3F1) were divided into twelve treatment groups (n = 15). The right buccal cheek mucosa was treated with CAP. The first and second group each received continuous 10 sec irradiation with 2 different plasma sources (kINPen09, PS-MWM). The third group was treated with the kINPen09 for one minute. Control groups were treated with a corresponding dose of ultraviolet light for 8 seconds or 48 seconds and the other one was left untreated. The animals were weighed before and after treatment. The animals were sacrificed one day or one week after exposure. Stained tissue samples were histologically examined for tissue damage independently by two experienced pathologists. One day after CAP treatment histological analysis showed focal mucosal erosion with superficial ulceration and necrosis accompanied by a mild inflammatory reaction. One week after CAP treatment, the mucosal defects were completely re-epithelialized, associated with remnants of granulation tissue in the stroma irrespective of treatment duration. Furthermore, no cytological atypia was found and no severe weight loss occurred. The control groups did not show any alterations at all. CAP treatment led to a superficial mucosal damage that healed within few days. Nonetheless, further long-term experiments are necessary to exclude undesirable side effects after longer observation time. Particularly, potential carcinogenic effects must be ruled out prior to the application of CAP treatment in daily dental practice

    Exploring park–people conflicts in Colombia through a social lens

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    Natural resource-related conflicts between local communities and nation states can be extremely destructive. Worldwide, interest is growing in gaining a better understanding of why and how these conflicts originate, particularly in protected areas inhabited by local communities. The literature on local attitudes towards and perceptions of park conservation and park-people conflicts is quite extensive. Studies have examined the socioeconomic and geographical determinants of attitudes to protected areas. However, the role of such determinants in the experience of park-people conflicts has received considerably less attention. Drawing on 601 interviews with people living in or near 15 Colombian national protected areas (NPAs), we examine the socioeconomic and geographical variables that are most influential in people's experience of conflict related to restricted access to natural resources. We find that the experience of this type of conflict is largely explained by the NPA where a person resides, pursuit of productive activities within the NPA, previous employment in NPA administration, gender and ethnicity. We recommend implementing socially inclusive conservation strategies for conflict prevention and resolution in Colombia's NPAs, whereby both women and men from different ethnic groups are engaged in design and implementation

    Key factors determining biochar sorption capacity for metal contaminants: a literature synthesis

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    The sorption capacity and affinity of biochar for metals are both important attributes that determine biochar’s suitability as a soil amendment for contaminant mitigation, yet few analyses have considered both characteristics simultaneously. We present a systematic review of literature published between 2010 and 2018 to test the hypothesis that sorption capacity and affinity are affected by biochar properties, attributes of the metal contaminant, and experimental conditions, in that order. We used random forest (RF) and multi-objective optimization to analyze data of 559 individual Langmuir adsorption isotherms extracted from 133 studies covering the sorption capacity (Cmax) and affinity (KL) of biochar for 17 different metals, elaborated from six different feedstock classes, three different types of feedstock pretreatment, and five types of post-pyrolysis treatment. Highest sorption values were obtained for Pb(II), Cr(IV), and Cd(II). The feedstock used was the key determinant influencing biochar’s capacity and affinity to sorb metal contaminants (first and fourth most important variable in RF models for Cmax and KL, respectively) with best results obtained for biochar elaborated from nutrient-dense feedstocks (animal biowaste, sludge, and manure). Biochars that had both high sorption capacity and affinity were the result of a longer duration of pyrolysis; they had lower C and higher N and O content, as well as lower C/N and higher O/C and H/C ratios, higher pore volumes and higher pH. Applying some form of pretreatment was better than none, whereas chemical modification was the best of the post-treatment methods analyzed. This review demonstrates clearly that multiple parameters during the preparation process influence the effectiveness of biochar to immobilize metal contaminants. Future research that focuses on mechanisms and the underlying factors for the correlations observed should allow the development of biochar formulations that are even more effective at immobilizing metal contaminants in soils and sediments

    Local working collections as the foundation for an integrative conservation of Theobroma cacao L. in Latin America

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    The intraspecific diversity of cacao has traditionally been preserved in genebanks. However, these establishments face various challenges, notably insufficient funding, accession redundancy, misidentification and lack of wild cacao population samples. In natural environments, it is expected that unknown varieties of cacao may still be found, but wild populations of cacao are increasingly threatened by climate change, deforestation, habitat loss, land use changes and poor knowledge. Farmers also retain diversity, but on-farm conservation is affected by geopolitical, economic, management and cultural issues, that are influenced at multiple scales, from the household to the international market. Taking separately, ex situ, in situ and on-farm conservation have not achieved adequate conservation fostering the inclusion of all stakeholders and the broad use of cacao diversity. We analyze the use of the traditional conservation strategies (ex situ, in situ and on-farm) and propose an integrated approach based on local working collections to secure cacao diversity in the long term. We argue that national conservation networks should be implemented in countries of origin to simultaneously maximize alpha (diversity held in any given working collection), beta (the change in diversity between working collections in different regions) and gamma diversity (overall diversity in a country)

    Present spatial diversity patterns of Theobroma cacao L. in the neotropics reflect genetic differentiation in Pleistocene refugia followed by human-influenced dispersal

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    Cacao (Theobroma cacao L.) is indigenous to the Amazon basin, but is generally believed to have been domesticated in Mesoamerica for the production of chocolate beverage. However, cacao's distribution of genetic diversity in South America is also likely to reflect pre-Columbian human influences that were superimposed on natural processes of genetic differentiation. Here we present the results of a spatial analysis of the intra-specific diversity of cacao in Latin America, drawing on a dataset of 939 cacao trees genotypically characterized by means of 96 SSR markers. To assess continental diversity patterns we performed grid-based calculations of allelic richness, Shannon diversity and Nei gene diversity, and distinguished different spatially coherent genetic groups by means of cluster analysis. The highest levels of genetic diversity were observed in the Upper Amazon areas from southern Peru to the Ecuadorian Amazon and the border areas between Colombia, Peru and Brazil. On the assumption that the last glaciation (22,000-13,000 BP) had the greatest pre-human impact on the current distribution and diversity of cacao, we modeled the species' Pleistocene niche suitability and overlaid this with present-day diversity maps. The results suggest that cacao was already widely distributed in the Western Amazon before the onset of glaciation. During glaciations, cacao populations were likely to have been restricted to several refugia where they probably underwent genetic differentiation, resulting in a number of genetic clusters which are representative for, or closest related to, the original wild cacao populations. The analyses also suggested that genetic differentiation and geographical distribution of a number of other clusters seem to have been significantly affected by processes of human management and accompanying genetic bottlenecks. We discuss the implications of these results for future germplasm collection and in situ, on farm and ex situ conservation of cacao

    Effects of the EU food safety regulation on cadmium on the cacao value chains of Colombia, Ecuador, and Peru

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    This briefing note combines information from three country reports conducted between 2021 and 2022, as well as relevant findings from the available literature to examine the current state of knowledge of the spatial distribution of Cd content in cacao farms in the three countries, how the EU regulation has affected different stakeholders, and how they are managing the problem. With the information presented in this document, we also improve and update literature available to date. The effects of the EU food safety regulations on cadmium in cacao (EU 488/2014 – EU 2021/1323 of 10 of August 2021) vary markedly between and within countries due to differences in markets and value chain structures. The regulation has caused severe localized impacts in specific cacao growing areas, nevertheless in general the impacts have been minor. Exporting companies and cooperatives are facing operational cost increases of up to 20%, related to Cd mapping, blending of cacao beans, increased traceability demands, marketing efforts, and additional laboratory testing. They also experience substantially lower prices and foregone incomes from changes in their clients. This has been critical for specialized cooperatives and producers in areas with high bean Cd. Changes in export destination for cacao during the last 4 years cannot solely be attributed to the regulation, but these represent foregone incomes in 2020 of nearly USD 3.4 million in Peru and USD 1.6 million in Colombia, equivalent to 2.4% and 6% of the countries’ cacao export value respectively. Adoption of similar food safety regulations by other importing countries may further limit the adaptation capacity of exporters and cooperatives
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