Incorporating intra-annual variability in fisheries abundance data to better capture population dynamics

To reduce the risk of overexploitation and the ensuing conservation and socio-economic consequences, fisheries management relies on receiving accurate scientific advice from stock assessments. Biomass dynamics models used in stock assessment tend to rely primarily on indices of abundance and commercial landings data. Standard practice for calculating the indices used in these models typically involves taking averages of survey tow data over large, diverse spatial domains. There is a lot of variability in the choice of methodologies used to propagate index uncertainty into the assessment model, many of which require specifying it through expert knowledge or prior distributions. Here we propose an alternative approach that treats each individual survey tow as an independent estimate of the true underlying biomass in the stock assessment model itself. This reduces information loss and propagates uncertainties into the model directly. A simulation study demonstrates that this approach accurately captures underlying population dynamics and reliably estimates variance parameters. We further demonstrate its utility with data from the Inshore Scallop Fishery of south-west Nova Scotia. Results show significant improvements in parameter estimation over previous models while providing similar predictions of biomass with less uncertainty. This reduced uncertainty can improve the resulting scientific advice and lead to improved decision-making by fisheries managers.publishedVersio

The Perception of Farmers on Climate Change and Variability Patterns in the Nzoia River Basin, Kenya

Global research experts have indicated that there is a growing trend in climate change and variability. Climate change has been altering the exposure of countries to weather related hazards, often exacerbating already existing vulnerabilities over the recent decades. Increasingly, the weather experienced then in terms of amounts of rainfall and temperature is no longer the same as it has always been over centuries based on previous records and scientific findings.   This paper sought to establish the perception of farmers on climate variability and patterns in the Nzoia River Basin, Kenya. The study adopted descriptive, and correlative research design. Data was collected using questionnaires, interview schedules and documented resource materials. The collected data was analyzed using Statistical Package for Social Scientists (SPSS) whereas climatic data of rainfall and temperature from Kenya Meteorological Service (KMS) and hectarage, and yield from the Ministry of Agriculture was analyzed using Microsoft excel. Results were presented in form of tables, charts and graphs. The study indicated that farmers had perceived an increase in temperature a decrease in rainfall, delay in onset of the rains, erratic and poor distribution of rainfall over the study period. The farmer’s perceptions on climate risk as a result of climate change and variability taking place in the basin has greatly influenced the cropping calendar, on-farm investments and decision-making in agricultural management and production negatively affecting yield of maize in the region.  The study recommends that the Government could help  to counteract the impact of climate change on agriculture by investing in research, soil conservation measures, technology, irrigation and water harvesting development, establishing local meteorology stations that will  give farmers relevant meteorological advice that will help them make informed farming options in each farming season. Keywords: Climate change, Climate variability, Perception, Weather

The role of decision confidence in advice-taking and trust formation

In a world where ideas flow freely between people across multiple platforms, we often find ourselves relying on others' information without an objective standard to judge whether those opinions are accurate. The present study tests an agreement-in-confidence hypothesis of advice perception, which holds that internal metacognitive evaluations of decision confidence play an important functional role in the perception and use of social information, such as peers' advice. We propose that confidence can be used, computationally, to estimate advisors' trustworthiness and advice reliability. Specifically, these processes are hypothesized to be particularly important in situations where objective feedback is absent or difficult to acquire. Here, we use a judge-advisor system paradigm to precisely manipulate the profiles of virtual advisors whose opinions are provided to participants performing a perceptual decision making task. We find that when advisors' and participants' judgments are independent, people are able to discriminate subtle advice features, like confidence calibration, whether or not objective feedback is available. However, when observers' judgments (and judgment errors) are correlated - as is the case in many social contexts - predictable distortions can be observed between feedback and feedback-free scenarios. A simple model of advice reliability estimation, endowed with metacognitive insight, is able to explain key patterns of results observed in the human data. We use agent-based modeling to explore implications of these individual-level decision strategies for network-level patterns of trust and belief formation

Performance trials on different rates and ratios of N and P fertilisation in Ethiopia to inform field-specific Maize-Nutrient-Management advisory

This report of the Scaling Readiness of Nutrient Management decision Support Tools project focuses on agronomic trials that serve to inform the development of scalable, field-specific advisory for maize farmers in Ethiopia. These trials were conducted to generate additional information required to make a mobile phone-based nutrient decision support tool – Maize-Nutrient-Manager – more scalable in the context of institutional limitations in fertilizer availability and distribution in Ethiopia. The focus of the trials is on establishing proper N:P ratio’s for different fertilization rates with the fertilizers available to farmers in West-Shewa and Jimma (two major maize belts in Ethiopia). The trials were conducted with additional funding from the TAMASA project and in collaboration with EIAR. As the latter institute is involved in conducting fertilizer trials and the development of recommendations, this collaboration also aimed at forming an appropriate entry point for institutionalization of the decision support tool that is being developed

Traveller Behaviour: Decision making in an unpredictable world

This paper discusses the nature and consequences of uncertainty in transport systems. Drawing on work from a number of fields, it addresses travellers’ abilities to predict variable phenomena, their perception of uncertainty, their attitude to risk and the various strategies they might adopt in response to uncertainty. It is argued that despite the increased interest in the representation of uncertainty in transport systems, most models treat uncertainty as a purely statistical issue and ignore the psychological aspects of response to uncertainty. The principle theories and models currently used to predict travellers’ response to uncertainty are presented and number of alternative modelling approaches are outlined. It is argued that the current generation of predictive models do not provide an adequate basis for forecasting response to changes in the degree of uncertainty or for predicting the likely effect of providing additional information. A number of alternative modelling approaches are identified to deal with travellers’ acquisition of information, the definition of their choice set and their choice between the available options. The use of heuristic approaches is recommended as an alternative to more conventional probabilistic methods

Relativistic financial decisions : context effects on retirement saving and investment risk preferences

We report a study of the effects the choice set on financial decision making related to retirement savings and risky investment. The participants were presented with either a full range of choice options or a limited subset of the feasible options. The choices of saving and risk are affected by the position of each option in the range of presented options. This result demonstrated that the range of the options offered as possible saving rates and levels of investment risk influences decisions about saving and risk. The study was conducted on a sample of working people, and we controlled whether the participants can financially afford in their real life the decisions taken in the test. In addition, various measures of risk aversion did not account for the risk taken in each condition. Surprisingly, only the simplest and most direct risk preference measure was a significant predictor of the responses within a particular choice set context, although the actual choices were still very much influenced by the range. Thus, the results reported here suggest that financial judgments and choices are relative, which corroborates, in an important practical domain, previous related work with abstract gambles and hypothetical risky investments

Doping in sport: a review of medical practitioners' knowledge, attitudes and beliefs.

BACKGROUND: Central to the work of many medical practitioners is the provision of pharmaceutical support for patients. Patients can include athletes who are subject to anti-doping rules and regulations which prohibit the use of certain substances in and out of competition. This paper examines the evidence on medical practitioners' knowledge, attitudes and beliefs towards doping in sport. METHODS: A systematic search strategy was followed. Research questions and relevance criteria were developed a priori. Potentially relevant studies were located through electronic and hand searches limited to English language articles published between 1990 and 2010. Articles were assessed for relevance by two independent assessors and the results of selected studies were abstracted and synthesised. Outcomes of interest were knowledge, attitudes and beliefs in relation to doping in sport. RESULTS: Six studies met the inclusion criteria and were examined in detail. Samples reflected a range of medical practitioners drawn from the UK, France (2), Greece, Italy and Ireland. The investigations varied with respect to outcome focus and quality of evidence presented. CONCLUSION: Whilst the extant empirical research posits a negative attitude towards illegal performance enhancement combined with a positive inclination towards doping prevention, it also exposes a limited knowledge of anti-doping rules and regulations. Insufficient education, leading to a lack of awareness and understanding, could render this professional group at risk of doping offences considering Article 2.8 of the World Anti-Doping Agency Code (WADC). Moreover, in light of the incongruence between professional medical codes and WADC Article 2.8, medical professionals may face doping dilemmas and therefore further discourse is required. At present, the current evidence-base makes it difficult to plan developmentally appropriate education to span the exposure spectrum. Addressing this situation appears warranted

Individual Investment Behaviour: A Brief Review Of Research

This brief review of research was carried out to inform whether the Personal Accounts Delivery Authority (PADA) should be making decisions for its members with regard to pension fund choices. The findings are based on a review of around 80 items, mostly involving research carried out in the US and UK. The body of evidence mainly comes from the discipline of economics and the field of behavioural economics in particular. Survey data was the most common type of evidence, but the review included qualitative research as well