title: Degradation as a result of UV radiation of bloodmeal-based thermoplastics

authors: Verbeek, Casparus Johan R.

subjects: bloodmeal

abstract: Polymers are known for their susceptibility to degradation as a result of ultra-violet (UV) radiation. In this study, the UV stability of bloodmeal-based thermoplastics (BMT) was evaluated over a period of 12 weeks. Formulations with and without plasticiser were tested and moisture was excluded during accelerated weathering to isolate the effect of UV because of the material’s known sensitivity to moisture. It was found that embrittlement due to loss of water overshadowed the effect of UV degradation. Embrittlement caused the material’s toughness to be reduced by an order of magnitude after only two weeks of exposure, for either plasticised or unplasticised samples. An initial increase in tensile strength was observed after two weeks followed by a steady decline in strength. The elastic modulus reached a plateau after about two weeks of exposure. FTIR did not confirm any chemical changes after 12 weeks exposure and TGA suggested that low molecular mass species were quickly lost during the course of the test. The absence of chemical changes does not suggest resistance to environmental degradation, although the dark pigmentation of bloodmeal may have contributed to the lack of UV degradation. Embrittlement remains a greater concern and requires further attention.

text: Degradation as a result of UV radiation of bloodmeal-based thermoplastics Polymers are known for their susceptibility to degradation as a result of ultra-violet (UV) radiation. In this study, the UV stability of bloodmeal-based thermoplastics (BMT) was evaluated over a period of 12 weeks. Formulations with and without plasticiser were tested and moisture was excluded during accelerated weathering to isolate the effect of UV because of the material’s known sensitivity to moisture. It was found that embrittlement due to loss of water overshadowed the effect of UV degradation. Embrittlement caused the material’s toughness to be reduced by an order of magnitude after only two weeks of exposure, for either plasticised or unplasticised samples. An initial increase in tensile strength was observed after two weeks followed by a steady decline in strength. The elastic modulus reached a plateau after about two weeks of exposure. FTIR did not confirm any chemical changes after 12 weeks exposure and TGA suggested that low molecular mass species were quickly lost during the course of the test. The absence of chemical changes does not suggest resistance to environmental degradation, although the dark pigmentation of bloodmeal may have contributed to the lack of UV degradation. Embrittlement remains a greater concern and requires further attention.

year: 2011

title: Red Sea fish market assessments indicate high species diversity and potential overexploitation

authors: Shellem, Claire T.

subjects: artisanal fishery

abstract: In many parts of the world, particularly remote and underdeveloped regions, reports of fisheries catch, effort, and landing data are limited. In order to implement effective fishing regulations to protect natural stocks, understanding fishing pressure, key target species, catch composition, and value of each species is vital. In regions where published data is limited, and the sampling of numerous small boats and landing sites is not feasible, fish market surveys represent an opportunity to obtain key fisheries data. This study therefore aims to obtain species-specific prices and market composition for fish landed in the central Red Sea by surveying local fish markets. We conducted 11 surveys at two major Red Sea fish markets to ascertain key fisheries metrics using market data as a proxy for catch data. Results indicate that a high proportion of the market composition is generated by 46 species from six family-level groups, Serranidae, Labridae, scarine labrids, Carangidae, Lethrinidae, and Lutjanidae, contributing to 87 % of the total market biomass. Species-specific values ranged from 4.50 USD/kg to 26.44 USD/kg, with market surveys highlighting the economic value of three local serranid species: Plectropomus pessuliferus marisrubri, Plectropomus areolatus and Variola louti, all valued at more than 25 USD/kg, and a labrid: Cheilinus undulatus, valued at 26.44 USD/kg. The Serranidae family represents 47 % of the total biomass and 55 % of the potential revenue in the market, while also indicating potentially overfished reefs due to the high occurrence of smaller species and undersized individuals of higher priced serranid species. Many of the high-valued serranids were below the size at sexual maturity. Target species exhibited small body size and decreasing abundance, potentially indicating a “shrinking baseline” scenario occurring in the Saudi Arabian artisanal coral reef fishery. These results indicate that introducing effective fisheries legislation and management is necessary for the longevity and sustainability of the reef-based fishery in the Saudi Arabian Red Sea. Implementing catch quotas, size limits, and seasonal restrictions are potential mechanisms that could be used to facilitate positive change within this vulnerable fishery.

text: Red Sea fish market assessments indicate high species diversity and potential overexploitation In many parts of the world, particularly remote and underdeveloped regions, reports of fisheries catch, effort, and landing data are limited. In order to implement effective fishing regulations to protect natural stocks, understanding fishing pressure, key target species, catch composition, and value of each species is vital. In regions where published data is limited, and the sampling of numerous small boats and landing sites is not feasible, fish market surveys represent an opportunity to obtain key fisheries data. This study therefore aims to obtain species-specific prices and market composition for fish landed in the central Red Sea by surveying local fish markets. We conducted 11 surveys at two major Red Sea fish markets to ascertain key fisheries metrics using market data as a proxy for catch data. Results indicate that a high proportion of the market composition is generated by 46 species from six family-level groups, Serranidae, Labridae, scarine labrids, Carangidae, Lethrinidae, and Lutjanidae, contributing to 87 % of the total market biomass. Species-specific values ranged from 4.50 USD/kg to 26.44 USD/kg, with market surveys highlighting the economic value of three local serranid species: Plectropomus pessuliferus marisrubri, Plectropomus areolatus and Variola louti, all valued at more than 25 USD/kg, and a labrid: Cheilinus undulatus, valued at 26.44 USD/kg. The Serranidae family represents 47 % of the total biomass and 55 % of the potential revenue in the market, while also indicating potentially overfished reefs due to the high occurrence of smaller species and undersized individuals of higher priced serranid species. Many of the high-valued serranids were below the size at sexual maturity. Target species exhibited small body size and decreasing abundance, potentially indicating a “shrinking baseline” scenario occurring in the Saudi Arabian artisanal coral reef fishery. These results indicate that introducing effective fisheries legislation and management is necessary for the longevity and sustainability of the reef-based fishery in the Saudi Arabian Red Sea. Implementing catch quotas, size limits, and seasonal restrictions are potential mechanisms that could be used to facilitate positive change within this vulnerable fishery.

year: 2021

title: AI: a new (r)evolution or the new colonizer for Indigenous peoples?

authors: Whaanga, Hēmi

abstract: We are often told that there is one constant in life and that is change; it is inevitable, inescapable. When the forces of power begin to blow and conditions are right, change will happen. As the planet undergoes a period of transformation brought about by the advances of data science and the convergence of technologies, the Internet of All Things and AI, the potential of AI to be change agent for Indigenous peoples is a thought-provoking, and to a certain degree, daunting proposition. The rapid progress of technology and innovation, in terms of its volume, complexity, and exponential growth in computing power, have drastically changed how we socialize, communicate, access, share, distribute and view knowledge and information. Is AI inevitable, inescapable, a fait accompli for Indigenous peoples?

text: AI: a new (r)evolution or the new colonizer for Indigenous peoples? We are often told that there is one constant in life and that is change; it is inevitable, inescapable. When the forces of power begin to blow and conditions are right, change will happen. As the planet undergoes a period of transformation brought about by the advances of data science and the convergence of technologies, the Internet of All Things and AI, the potential of AI to be change agent for Indigenous peoples is a thought-provoking, and to a certain degree, daunting proposition. The rapid progress of technology and innovation, in terms of its volume, complexity, and exponential growth in computing power, have drastically changed how we socialize, communicate, access, share, distribute and view knowledge and information. Is AI inevitable, inescapable, a fait accompli for Indigenous peoples?

year: 2020