Community-based fish culture in seasonal floodplains

During the rainy season in extensive river floodplains and deltaic lowlands, floods render the land unavailable for crop production for several months each year. These waters are considerably underutilized in terms of managed aquatic productivity. This raises the opportunity to enclose parts of these floodwater areas to produce a crop of specifically stocked aquatic organisms aside from the naturally occurring ‘wild’ species that are traditionally fished and are not affected by the culture activity, resulting in more high-quality, nutrient-dense food production and enhanced farm income for all stakeholders, notably the poor. The WorldFish Center and its national partners recently tested the concurrent rice-fish culture in the shallower flooded areas and the alternating rice-fish culture in the deep-flooded areas of Bangladesh and Viet Nam through a community-based management system. Results indicate that community-based fish culture in rice fields can increase fish production by about 600 kg/ha/year in shallow flooded areas and up to 1.5 t/ha/year in deep-flooded areas, without a reduction in the rice yield or wild fish catch

Multivariate methods in aquaculture research: case studies of tilapias in experimental and commercial systems

This volume documents the usefulness of multivariate methods û notably multiple regression, path analysis and canonical correlation û in the context of aquaculture, which has to date tended to neglect such methods, and hence to underutilize available data. All examples used here stem from experimental and/or commercial tilapia culture systems, and hence this book also represents an advance in the understanding of such systems.Aquaculture, Tilapia culture, Growth, Multivariate analysis Oreochromis

Employee engagement: a key to organisations’ competitive advantage and success

Employee Engagement: A key to organisations’ competitive advantage and success This work project is a literature review, covering studies that have been conducted up until now on the topic of Employee Engagement, and discusses some antecedents and consequences of its use in organisations. Moreover, several recommendations to increase Employee Engagement are presented. We conclude that organisations across the industries are not yet realizing the strong influence Employee Engagement has on their success, and that they should start implementing and giving a great deal of importance to Human Resources practices that foster engagement, such as training, if they want to keep their employees engaged in an uncertain world of work

Impact pathway analysis for research planning: the case of aquatic resources research in the WorldFish Center

In line with its mandate of poverty reduction and sustainable development, the WorldFish Center is orienting its research towards high impact scientific activity. Identifying such activities is the task of prospective impact assessment, in turn based on impact pathway analysis. The paper describes a framework for analyzing benefits from aquatic resources research, the relevant research categories, pathways to impact by category, and indicators along each pathway that can be estimated in order to quantify probable research impact

Using Monte-Carlo-algorithms for the estimation of ß-error: alternative inference strategies for multidimensional contingency tables

Small samples and sparse cell frequencies cause major problems for statistical modelling with categorical data: Sampling zeros or small expected frequencies can lead to situations where asymptotic approximations of test statistics will be inadequate. In such cases one resorts to the use of exact tests or Monte-Carlo-simulations. But also in this ease, inference can yield problematie results, as the power of tests is often extremely low and will therefore lead to the rejection of theoretically plausible hypotheses on the base of poor empirical material. In this paper an alternative modeHing strategy for small samples using Monte-Carlo-algorithms is presented. This strategy is extending the asymptotic power approximations presented by Cohen (1977) or Agresti (1990)

The Impact of Bailouts on Political Turnover and Sovereign Default Risk

This paper develops a stochastic dynamic politico-economic model of sovereign debt to analyze the impact of bailouts on political turnover and sovereign default risk. We consider a small open economy in which the government has access to official loans conditional on the implementation of austerity policies. There is a two-party system in which both parties care about the population's welfare but differ in an exogenous utility cost of default. Political turnover is the endogenous outcome of the individual voting behavior. In a quantitative application to the Greek economy, we find that bailouts amplify political turnover risk, which, in turn, elevates sovereign interest spreads. While stricter conditionality fosters the probability of political turnover and sovereign default in the short run, it may mitigate political turnover and default risk in the long run. The frequency of political turnover is U-shaped in the strength of conditionality. (C) 2021 Elsevier B.V. All rights reserved.Peer reviewe

Effect of Varying Material Properties on the Available Rotation Capacity of a One-Way Slab

The influence of reinforcing steel properties on the behavior of a one-way slab is investigated. A number of European and American reinforcing steels are evaluated at different effective reinforcing ratios and their influence on the rotation capacity of the slab is determined. The effect of high strength concrete in a slab with large effective reinforcing ratios also is addressed. Analytical work is performed using a nonlinear finite element approach in a three-dimensional model. To simulate the behavior of concrete in tension, the smeared crack approach is used, while compression softening is approximated with the Willam-W arnke model. The stressstrain behavior of the reinforcing steel is incorporated using a multilinear elastic strain-hardening model and a model for bond-slip is adapted to take the structural response at the steel-concrete interface into account. During preliminary studies different models for compression softening and concrete behavior under tension were investigated. Also, the effects of the mesh, convergence tolerances and load step size were studied. Analyses are performed for three point bending and the load is applied by imposing displacements on the system. To calibrate the finite element model, the results are compared to experimental data. Load-displacement curves are generated to measure the response of the system and the maximum amounts of carrying capacity obtained from the finite element analysis are compared to predictions using ACI 318-95 (1995) design equations. The results of this study suggest that the influence of the ductility characteristics of the reinforcing steel on the rotation capacity of the structure depend on the effective reinforcing ratio of the specimen. At low reinforcing levels, the structural behavior is governed by the ductility characteristics of the steel, thus, the amount of deflection at failure depends on the ultimate elongation capability of the steel. By increasing the amounts of steel in the structure, the overall behavior is shifted from a ductile to a brittle failure mode. Therefore, in structures with moderate amounts of reinforcement the choice of reinforcing steel determines whether the structural behavior is governed by the steel characteristics or the concrete behavior. At high reinforcing levels, the concrete characteristics completely determine the structural behavior and generally all specimens with high effective reinforcing ratios exhibit a failure of the compression strut in the concrete - a brittle failure mode while the steel does not reach its yield capacity. The carrying capacity for all analysis cases with large amounts of reinforcement was found significantly under the capacities calculated with the ACI equations. Finally, all analyzed cases exhibited insensitivity to the effects of bond-slip

Wastewater use in aquaculture: research in Peru

Use of wastewater is an issue gaining importance throughout the (developing) world, as water sources become scarcer and competition for them increases. In Peru, research has shown the technical, economic and social feasibility of growing fish in wastewater. Such fish farms could recover 100% of the wastewater treatment costs

Aquaculture potential of seahorses and pipefishes

The characteristics, food and feeding, reproduction and breeding of sea horse and pipefishes (Synanthidae) are presented together with the aspects of syngnathid culture