Étude préliminaire sur l'incorporation de liants dans un aliment composé pour poisson d'élevage en Côte d'Ivoire

Artificial feeding constitutes a very important aspect for intensive fish culture. Then, the physical properties, particularly water stability of feed, wider influence the fish production. By trying to find some answers to these problems, a preliminary study on water stability has been conducted at the LAYO aquaculture research station. This work consisted in incorporating different types of binders available in tropical countries in fish pellets of 3.5 mm and 6.0 mm diameters in order to identify an efficient binder allowing the improvement of the water stability of feed. From this experiment, it comes out that the use of wheat flour (A1) gives excellent quality pellets followed by cassava flour residue (A3). Moreover, this study shows that it exists an influence of the diameter on the crumbling of the pellets

Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 4- Thermal biology of embryos and larvae

The knowledge of how fish survive and grow at different temperatures, and how these traits vary between life stages, is essential to evaluate the effects of climate change on wild fish and implement effective strategies in aquaculture. These issues are addressed in this study through a series of experiments that evaluate the effect of temperature (23-34 degrees C) on the embryos and larvae of clown loach, Chromobotia macracanthus. This species is endemic to the rivers of Sumatra and Borneo, highly praised on the ornamental fish market, and has been reproduced in captivity recently. No embryo survived a 24-h exposure to 34 degrees C until the age of 3 days after hatching (dah); mortality was high at 32 degrees C at 2 and 3 dah, whereas it was low and similar from 1 to 4 dah at 23-29 degrees C (<10%). Yolk absorption was proportional to water temperature (Q(10 degrees C) of 1.69 in the 23-32 degrees C range), but fish reared at cold temperatures were larger than others at the start of exogenous feeding (5.7 vs. 5.5 mm TL, at 23 and 32 degrees C, respectively). The survival of larvae fed Artemia nauplii ad libitum was high at 23-32 degrees C (80-100%), but almost null at 34 degrees C. Growth models at different temperatures were produced from weekly measurements in two experiments, and tested by comparing their predictions with the results of a third experiment. Throughout the larval stage, the optimal temperature for growth (T. opt) was close to 29 degrees C, and departures from T. opt resulted in substantial growth penalties (-30% SGR for -5.1 degrees C and +3.1 degrees C). High survival, fast growth (0.7 mm day(-1)) and limited size dispersal at T. opt are encouraging perspectives for the aquaculture of clown loach. From an ecological perspective, the species has an atypical thermal biology, as it is less thermophilic than other tropical fishes, but more stenothermal than temperate fishes exhibiting similar values of T. opt, both traits being of particular concern in the context of global warming

Handheld pose tracking using vision-inertial sensors with occlusion handling

Tracking of a handheld device’s three-dimensional (3-D) position and orientation is fundamental to various application domains, including augmented reality (AR), virtual reality, and interaction in smart spaces. Existing systems still offer limited performance in terms of accuracy, robustness, computational cost, and ease of deployment. We present a low-cost, accurate, and robust system for handheld pose tracking using fused vision and inertial data. The integration of measurements from embedded accelerometers reduces the number of unknown parameters in the six-degree-of-freedom pose calculation. The proposed system requires two light-emitting diode (LED) markers to be attached to the device, which are tracked by external cameras through a robust algorithm against illumination changes. Three data fusion methods have been proposed, including the triangulation-based stereo-vision system, constraint-based stereo-vision system with occlusion handling, and triangulation-based multivision system. Real-time demonstrations of the proposed system applied to AR and 3-D gaming are also included. The accuracy assessment of the proposed system is carried out by comparing with the data generated by the state-of-the-art commercial motion tracking system OptiTrack. Experimental results show that the proposed system has achieved high accuracy of few centimeters in position estimation and few degrees in orientation estimation

Not a drop to drink: Emerging meanings in local newspaper reporting of the 1995 water crisis in Yorkshire

This article takes data from the Huddersfield Examiner (HE) and the Yorkshire Evening Post (YEP) and critically analyzes discourse features of the November 1995 drought as reported in these papers. It suggests that this kind of discourse generates new linguistic categories, which exist between the generalized patterns of language (langue) and the differentiated experience of language in context (parole). Whilst the langue-parole distinction is no longer seen as absolute, if it is seen as a gradable concept it could capture the tension between stability and change characterizing actual linguistic experience of discourse participants. The value of textual analysis is discussed and the article asks how far texts can be described as (re)producing ideologies in a particular context. The research reported here is based on a small, discrete corpus of news texts and concludes that the data in question produce a meaning for the word water that differs from its meaning over larger bodies of data, and yet which maps closely onto the meaning of the word commodity. The general ideological outlook encompassing this view of water as productlike and passive, rather than a natural resource with its own agency, is considered as an ‘explanatory’ mechanism linking this news ‘story’ with a dominant capitalist ideology

The management of professional roles during boundary work in child welfare

This article examines the ways in which child welfare professionals negotiate their roles and those of other professionals in home visits with clients, in this case the parents of young children. The concept of boundary work is developed within the context of the professional–client encounter. Drawing on Goffman's concept of ‘footing’, the analysis examines how professionals attend to ways of constructing family problems in terms of appropriate professional interventions – both from themselves and others. It is argued that the careful consideration of how problems merit interventions displays an adherence to the development of the supportive relations which move beyond strict professional remits. The article adds to the research evidence, which sees inter-professional coordination as a complex matter, located in everyday practice rather than as advocating more tightly monitored procedure

Traditional pharmacopeia in small scale freshwater fish farms in West Java, Indonesia : an ethnoveterinary approach

The use of plants for herbal medicine in the Indonesian aquaculture is still poorly known. The present study aimed to provide an inventory of the plants used by fish farmers, establishing their respective ethnobotanic importance and identifying the variables that determine the use and the choice of these plants in fish health management. A survey based on a semi-directive questionnaire was conducted using a representative sample of fish farmers (n = 504 from 176 villages) from the province of West Java. Of these fish farmers, 46% [41%, 50%; CI95%] of them use plants in their farms and 79 species of plants belonging to 36 families have been identified. Most of these plants were common plants used also traditionally in human pharmacopeia. Four categories of plant use were identified namely: improvement of water quality; reduction of fish stress; increase of fish resistance to pathogens; and treatment of fish diseases (when an outbreak occurred). In order to appraise the significance of plant usage, the following ethnobotanic parameters were determined: the Use Value (UV), the Fidelity Level (FL) and the Informant Consensus Factor (ICF). The Use Value (UV) was generally low for plants except for Carica papaya which reached the highest UV scores. The majority of the plants were used according to personal experience of the fish farmers and the knowledge related to herbal therapy appeared variable among fish farmers. Only 26 species of plants had a UV > 0.025. The highest Fidelity Level (FL) value was obtained for C. papaya. The Informant Consensus Factor (ICF) of each plant usage was relatively high for all four categories of use - ranging from 0.78 to 0.88 - but the same plant may have several therapeutic indications. The use of plants, as well as their variety and number, depended not only on fish species, production systems and production areas but also on social characteristics such as the professional experience of fish farmers and their ethnic origin. To our knowledge, this is the first ethnobotanic survey specifically applied to aquaculture. It was able to identify the species of plants used in the West Java Province, and how they are used. It also highlighted the significance of traditional Indonesian herbal therapy in aquaculture. The use of several plants in aquaculture is reported for the first time in this study

Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 3- Ontogeny, ecological and aquacultural implications

International audienceHatchlings of clown loach (3.8 mm in total length, TL) are pelagic. When reared at 26-28 degrees C, they become benthic 3 days after hatching (dah), when their swim bladder is inflated. The fin development sequence (pectorals 20% WM in fish >7 mm TL. Gut evacuation rate (R-g) increases with increasing meal size and fish size, as a result of gut coiling (from 8 to 15 mm TL), and is highest at 11 mm TL (about 10% WM h(-1) in fish feeding maximally). The allometric increase of FI and R-g during the early larval stages is accompanied by increasing capacities for growth, so early sizes differences amplify rapidly during the ontogeny. Nevertheless, growth remains slow (mean of 0.4 mm TL day(-1) from 4 to 29 dah; 0.9 mm TL day(-1) for top growers). By contrast, unfed fish display long resistance to starvation (until 14-15 dah). The combination of slow growth and long resistance to starvation is discussed in respect to the reproductive phenology of the species, as the capacity of making metabolic economies prevails over fast growth for seasonal strategists spawning mainly at the start of the rainy season

Discourses on Well-Being

In the current South African socio-political framework children have been afforded the highest priority within government, via affirmation of their rights. Not only have the rights and needs of children been entrenched in the development strategies of the government, but children themselves have been guaranteed socio-economic rights and protection from abuse, exploitation, and neglect. Subsequently, knowledge and information on the well-being of children have become important pursuits. It has also become increasingly important to obtain an understanding of what children regard as essential to their well-being. The current study explores children's subjective perceptions of well-being, with a specific focus on elucidating the discourses that children use to assign meaning to well-being. A qualitative study was conducted using a series of focus group discussions with 56 children between the ages of 13 and 15 from rural and urban geographical locations. A discourse analysis reveals a complex interplay between the social environment and the children's sense of well-being. Three key thematic domains were identified, namely, personal safety, infrastructural deficiencies, and psycho-social functioning. Central discourses to emerge from these thematic domains were closely interrelated and mutually influencing and focussed on, personal safety, the social environment and a stable self as 'non-negotiables' of well-being, helplessness and vulnerability, desensitisation, marginalisation, (non)acknowledgement and (dis)respect. A notable finding emerging from the study was the extent to which the participants' discursive constructions of well-being were ideologically configured. The findings raise important considerations for educational and intervention programmes and policies aimed at children and youth