965 research outputs found
MARX AND WEBER: A THEORY OF HISTORICAL CHANGE
Though historical sequences of Western civilization are capable of being described by a simple, unilinear, evolutionary theory of history, attempts to generalize unilinear theories beyond Western cultural areas have failed. Thus the attempts of modem "Marxists" to generalize Marx and Engels' "theory of history" beyond its scope of application, Western civilization, have met with the expected results. Their sequence of stages of history simply do not fit other cultural areas. The Marx-Engels theory of history was explicitly designed for a single case and has little or no application outside that case.The theory therefore has no explanatory power and may be viewed as simply a tool for describing a single case. Extension of the theory beyond that case would require modification, specifically conceptual elaboration, such that it becomes more than simply descriptive.http://web.ku.edu/~starjrn
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Microencapsulated diets to improve the productivity of bivalve shellfish aquaculture for global food security
Food is the single strongest lever to optimise human health and environmental sustainability on earth. However, food production and consumption patterns today threaten both people and planet. We face a double-burden of malnutrition and overconsumption, with two billion people micronutrient deficient and over two billion people overweight or obese, and the global food system is now the single largest greenhouse-gas-emitting sector. Bivalve shellfish – including mussels, clams, and oysters – could be an invaluable component of our global food solution. Bivalves are nutrient rich, production has a lower environmental footprint than that of all other animal foods, and developing just 1% of the coastline suitable for bivalves worldwide would provide over one billion people with all their protein needs. To realise global potential there is an urgent need for innovation to enable increased bivalve production and consumption. This thesis aimed to test whether new innovations in microencapsulated feeding technology could be used to overcome major bivalve industry bottlenecks and help drive a step change in our global food system.
The initial research focus was to assess the potential of microencapsulated feeds as a problem-solving tool in bivalve aquaculture and test viability via laboratory experiments. I performed a critical review to assess key industry challenges and identify where microencapsulation technology could most effectively be applied. Experimental tests then allowed me to demonstrate that microencapsulated feeds could be ingested by a commercially farmed bivalve, the blue mussel (Mytilus edulis), providing a foundation for research on specific industry challenges.
The second phase of the thesis assessed the effectiveness of microencapsulated feeds to tackle major bivalve hatchery bottlenecks in juvenile growth and broodstock conditioning. I undertook research both in the laboratory and at a commercial hatchery to reveal that microencapsulated feeds could increase the growth and survivorship of European oyster (Ostrea edulis) juveniles relative to conventional live algal diets. I then demonstrated that the feeds could facilitate improved sexual development in O. edulis broodstock and enable this stage of bivalve production to become an order of magnitude more sustainable and economically efficient.
The final phase of the thesis aimed to use both experimental and literature analyses to explore how microencapsulated diets and bivalve aquaculture could help tackle broader nutritional problems and contribute towards food security goals. I identified an optimal dosing strategy to fortify Pacific oysters (Crassostrea gigas) with vitamin A and D, and outlined how tailoring the micronutrients encapsulated and bivalve species reared could provide a low cost mechanism to tackle regional nutritional deficiencies directly through the food supply. I then built on this global perspective and reviewed how expansion of bivalve aquaculture could help tackle food security challenges in the developing world. Key components of the value chain requiring further research, industry investment and policy changes were identified, alongside the importance of a multifaceted strategy to stimulate increased consumer demand.
To summarise, my work in this thesis has demonstrated how applying new innovations in microencapsulation technology to bivalve aquaculture can provide powerful solutions to a range of industry challenges. Scale up and further application of the research breakthroughs I have made can contribute towards a global revolution in food production with widespread benefit to human and planetary health.BBSRC Doctoral Training Program (UKRI
Microencapsulated diets to improve bivalve shellfish aquaculture.
Aquaculture is the fastest growing food sector and feeds over 3 billion people. Bivalve shellfish aquaculture makes up 25% of global aquaculture production and is worth annually US$19 billion, but continued growth is currently limited by suboptimal diets and limited tools for disease control. New advances in microencapsulation technology could provide an effective way to overcome these biological limitations. This study demonstrated that a new formulation of microencapsulated diet known as BioBullets could be ingested by a commercially farmed bivalve; the blue mussel Mytilus edulis. Microparticles could be captured by mussels with similar efficiency to natural foods. Microparticles too large for ingestion were rejected in pseudofaeces. Microparticles were successfully ingested and broken down by the gut. Further work is needed to assess the impact of BioBullets diets on bivalve growth. There is now an exciting opportunity to tailor the composition of microencapsulated diets for specific applications to improve production output and efficiency in the commercial bivalve shellfish industry
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Microencapsulated diets to improve growth and survivorship in juvenile European flat oysters (Ostrea edulis).
Sustainable expansion of aquaculture is critical to global food security, and bivalve shellfish aquaculture represents a sustainable method to provide people with affordable nutritious food. Oysters represent 54% of the global bivalve market by value, with propagation of juveniles within hatcheries critical to allow the industry to grow. Growth and survival of juvenile oysters in hatchery systems is constrained by suboptimal feed. The live algal feed currently used is expensive, of variable quality, contamination prone, and the high level of skill and equipment required limits where hatcheries can be located. We demonstrate how a novel microencapsulated diet can increase the growth and survivorship of Ostrea edulis (European flat oyster) juveniles in both the laboratory and hatchery setting. The microcapsules are easily produced in large quantities, stable for long term storage, and can be customised to have exceptionally high levels of nutrients key for oyster growth. O. edulis larvae fed a combined diet of microcapsules and algae for 8 days had a 46% greater increase in maximum size, 171% greater increase in minimum size, and 5% higher survival than larvae fed algae alone. O. edulis spat of 4 mm fed the combined diet for 7 weeks also had significantly greater survivorship (16% greater in hatchery, 58% greater in laboratory) and growth comparable (hatchery) or better (laboratory experiments) than algae alone. Further tailoring of the nutritional composition of microcapsules to specific bivalve species or growth stages could allow microcapsules to replace a greater proportion of or even completely replace algal diets. There is potential for these diets to revolutionise bivalve shellfish farming globally
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Organic food: what we know (and do not know) about consumers
This paper reports on the latest contributions to over 20 years of research on organic food consumers. There is a general consensus in the literature on the reasons why people buy organic food. However, there is also a gap between consumers’ generally positive attitude toward organic food and their relatively low level of actual purchases. Product differentiation based on intangible features, such as credence attributes such as organic, in fast-moving consumer goods categories is enjoying rapid growth. However, there are many difficulties with research in this area, including the errors inherent in research that relies on consumer self-reporting methodologies. Further, in relation to organic food, there is a divergence between consumers’ perception of its superior health features and scientific evidence. Fresh fruits and vegetables are of vital importance to the organic sector as they are the entry point for many customers and account for one-third of sales. Further, although there is a small proportion of dedicated organic food buyers, most sales come from the majority of buyers who switch between conventional and organic food purchases. This paper identifies the practical implications for generic organic food marketing campaigns, as well as for increasing sales of specific products. It concludes with suggested priorities for further research
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Vitamin Bullets. Microencapsulated Feeds to Fortify Shellfish and Tackle Human Nutrient Deficiencies
Over two billion people worldwide are micronutrient deficient, with regionally specific deficiencies. Fortification of food with micronutrients has become an industry standard for enhancing public health. Bivalve shellfish (e.g., oysters, clams, and mussels) provide the most sustainable source of animal protein on the planet, and the market is rapidly growing—with production in China increasing 1,000-fold since 1980 to an annual 36 kg capita−1 consumption level. Bivalves are also unique in that micronutrients consumed at their end-life stage will be digested by humans, as humans consume the entire organism including the gut. We have developed a novel microencapsulated vehicle for delivering micronutrients to bivalves, tailored for optimal size, shape, buoyancy, and palatability, demonstrating the potential of fortified bivalves to tackle human nutrient deficiencies. Oysters fed vitamin A and D microcapsules at a 3% initial dosage for just 8 h had elevated tissue vitamin content. A serving of just two such bivalves provides enough vitamin A and D to meet human dietary RDAs. Scale-up of this technology and application to other bivalve species including clams and mussels could provide a low-cost and highly sustainable mechanism to contribute toward tackling nutrient deficiencies globally
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