29 research outputs found
Beyond âyesterdayâs tomorrowâ: future-focused mobile interaction design by and for emergent users
Mobile and ubiquitous computing researchers have long envisioned future worlds for users in developed regions. Steered by such visions, they have innovated devices and services exploring the value of alternative propositions with and for individuals, groups and communities. Meanwhile, such radical and long-term explorations are uncommon for what have been termed emergent users; users, that is, for whom advanced technologies are just within grasp. Rather, a driving assumption is that todayâs high-end mobile technologies will âtrickle downâ to these user groups in due course. In this paper, we open the debate about what mobile technologies might be like if emergent users were directly involved in creating their visions for the future 5â10 years from now. To do this, we report on a set of envisioning workshops in India, South Africa and Kenya that provide a roadmap for valued, effective devices and services for these regions in the next decade. © 2016, The Author(s)
Variable water input controls evolution of the Lesser Antilles volcanic arc
Oceanic lithosphere carries volatiles, notably water, into the mantle through subduction at convergent plate boundaries. This subducted water exercises control on the production of magma, earthquakes, formation of continental crust and mineral resources. Identifying different potential fluid sources (sediments, crust and mantle lithosphere) and tracing fluids from their release to the surface has proved challenging1. Atlantic subduction zones are a valuable endmember when studying this deep water cycle because hydration in Atlantic lithosphere, produced by slow spreading, is expected to be highly non-uniform2. Here, as part of a multi-disciplinary project in the Lesser Antilles volcanic arc3, we studied boron trace element and isotopic fingerprints of melt inclusions. These reveal that serpentineâthat is, hydrated mantle rather than crust or sedimentsâis a dominant supplier of subducted water to the central arc. This serpentine is most likely to reside in a set of major fracture zones subducted beneath the central arc over approximately the past ten million years. The current dehydration of these fracture zones coincides with the current locations of the highest rates of earthquakes and prominent low shear velocities, whereas the preceding history of dehydration is consistent with the locations of higher volcanic productivity and thicker arc crust. These combined geochemical and geophysical data indicate that the structure and hydration of the subducted plate are directly connected to the evolution of the arc and its associated seismic and volcanic hazards
The relative importance of COVIDâ19 pandemic impacts on biodiversity conservation globally
Abstract: The COVIDâ19 pandemic has had an enormous impact on almost all aspects of human society and endeavor; the natural world and its conservation have not been spared. Through a process of expert consultation, we identified and categorized, into 19 themes and 70 subthemes, the ways in which biodiversity and its conservation have been or could be affected by the pandemic globally. Nearly 60% of the effects have been broadly negative. Subsequently, we created a compendium of all themes and subthemes, each with explanatory text, and in August 2020 a diverse group of experienced conservationists with expertise from across sectors and geographies assessed each subtheme for its likely impact on biodiversity conservation globally. The 9 subthemes ranked highest all have a negative impact. These were, in rank order, governments sidelining the environment during their economic recovery, reduced wildlifeâbased tourism income, increased habitat destruction, reduced government funding, increased plastic and other solid waste pollution, weakening of natureâfriendly regulations and their enforcement, increased illegal harvest of wild animals, reduced philanthropy, and threats to survival of conservation organizations. In combination, these impacts present a worrying future of increased threats to biodiversity conservation but reduced capacity to counter them. The highest ranking positive impact, at 10, was the beneficial impact of wildlifeâtrade restrictions. More optimistically, among impacts ranked 11â20, 6 were positive and 4 were negative. We hope our assessment will draw attention to the impacts of the pandemic and, thus, improve the conservation community's ability to respond to such threats in the future
A toxic diet:transfer of contaminants to offspring through a parental care mechanism
The transfer of maternal contaminants to offspring during oogenesis and gestation is documented in many animals, and in mammals, contaminants may pass from mother to offspring during lactation. Although other non-mammalian vertebrates provide parental care in the form of nutritive secretions for offspring to feed from, the potential for toxicant transfer during non-mammalian parental care is rarely considered. The discus fish, Symphysodon spp., employs an unusual parental care strategy where fry feed on parental epidermal mucus for several weeks after hatching. This strategy has the potential to act as a method of contaminant transfer. In discus adults, both waterborne and dietary toxicants are sequestered and secreted into their epidermal mucus, the food on which fry depend. To determine whether parents could channel these contaminants directly to offspring, we exposed parents to aqueous cadmium (Cd) and recorded the subsequent feeding behaviour and Cd content of fry. Fry continued to feed normally from contaminated mucus and accumulated significant tissue concentrations of Cd. In conclusion, this parental care mechanism of the discus fish can expose offspring to harmful contaminants during the sensitive early stages of life and highlights that parent to offspring contaminant transfer after birth may be more widespread than previously thought
Accumulation of dietary and aqueous cadmium into the epidermal mucus of the discus fish Symphysodon sp.
The discus fish Symphysodon sp. is an Amazonian cichlid with a unusual form of parental care where fry obligately feed from parental mucus for the first few weeks of life. Here, we investigated the possible impact of environmental cadmium on this species, particularly with respect to mucus contamination. We exposed groups of fish to cadmium either through their food (400mgkg-1) or through the water (3Όgl-1) for 4weeks, and measured tissue concentrations and ATPase activities at weekly intervals. Cadmium significantly accumulated in all tissues (except for muscle) after 7days, and tissue concentrations increased until the end of the experiment. Significant alterations in ATPase activities of intestine and kidney were observed at day 7 and 14, but no alterations in gill ATPase activities occurred. The epidermal mucus showed a high accumulation of cadmium from both exposures, but particularly from the diet, indicating that dietary cadmium can be transferred from gut to mucus. Combining this data with approximations of fry bite volumes and bite frequencies, we constructed daily estimates of the cadmium that could potentially be consumed by newly hatched fry feeding on this mucus. These calculations suggest that feeding fry might consume up to 11Όgg-1day-1, and hence indicate that this species' dependency on parental mucus feeding of fry could make them particularly susceptible to cadmium contamination of their native habitat. © 2011 Elsevier B.V
Cadmium uptake in the mucus of discus fish, Symphysodon; potential consequences for reproduction
Combination of decisions from a multiple neural network classifier system
In this paper, a study of the effectiveness of a multiple classifier system (MCS) in a medical diagnostic task is described. A hybrid network, based on the integration of a fuzzy ARTMAP and the probabilistic neural network, is employed as the basis of the MCS. Outputs from multiple networks are combined using some decision combination method to reach a final prediction. By using a real medical database, a set of experiments has been conducted to evaluate the performance of the MSC with different network configurations. The experimental results reveal the potential of the MCS as a useful decision support tool in the medical field.<br /
Impaired reproduction in three-spined sticklebacks exposed to ethinyl estradiol as juveniles
To investigate the population-level effects of exposure to environmental endocrine disrupters, a mesocosm-scale study was carried out in which the reproductive performance of groups of free-spawning three-spined sticklebacks, Gasterosteus aculeatus, exposed as juveniles to a model estrogen, was assessed. Juvenile sticklebacks were exposed to ethinyl estradiol (EE2) at measured concentrations of (mean ± SEM) 1.75 ± 0.37 ng Lâ1 and 27.7 ± 1.08 ng Lâ1 for 4 wk posthatch and then reared thereafter in pristine lake water until they reached adulthood. Exposure to the higher EE2 concentration resulted in the occurrence of ovotestis among males, whereas no gonadal abnormalities were evident among males exposed to the lower concentration of EE2. In addition, when spawning was allowed in the mesocosm environment, fewer nests were built per male, and fewer eggs were deposited per nest, in the group exposed to 27.7 ng Lâ1. Males from this group also exhibited a less intense nuptial coloration than control males. In the group exposed to 1.75 ng Lâ1 EE2 posthatch, significantly fewer nests were built than in the control group. These results demonstrate that the timing of exposure to estrogenic contaminants, in developmental terms, is critically important. Short-term exposure to estrogens as juveniles can clearly influence reproductive performance as adults, despite all growth and development subsequent to the exposure period taking place in an estrogen-free environment. In addition, these results suggest that reproductive dysfunction can occur even in fish with no gross abnormalities in gonadal structure. This suggests that the absence of gonadal intersex is not a reliable indicator of the reproductive potential, or estrogen-exposure history, of fish populations or the only important factor involved in compromising the reproduction of estrogen-exposed fish