No abstract

Use of enzyme-linked immunosorbent assay (ELISA) is recommended for control of Johne's disease (JD) in the cattle industry. A recent report showed that prevalence of JD in dairy farms could be reduced by applying an ELISA-based control strategy, even though the sensitivity of the current ELISA has been reported to be lower than 30%. We previously developed a more sensitive ELISA test (EVELISA; Ethanol Vortex ELISA) for diagnosis of JD and, in this report, aimed to evaluate cost-effectiveness of the EVELISA in JD control compared to that of a current ELISA test. For simulation of population dynamics, we developed a deterministic, discrete-time mathematical model incorporating contact structure, possibility of adult infection and the concept of order of events. In our model, the number of animals infected with the causative agent of JD, Mycobacterium avium subsp. paratuberculosis (MAP), increases in a 10-year simulation if no JD control measure is applied. When test results of ELISA or EVELISA are used for JD control, the increase in MAP-infected animals is less significant. According to our model, EVELISA-based control measures increase the annual per capita revenue of US dairy farms when compared to no JD control and ELISA-based JD control, respectively.

Abstract:Small, open developing economies in general, and small island developing states (SIDS) in particular, have specific macroeconomic characteristics due both to their openness and their small size. Small size means they can never have fully independent capital-intensive domestic economies, so to raise incomes they must become thoroughly integrated into the global economy. The export sector thus becomes the engine of growth; it provides domestic income, which is spent on domestic goods and imports, driving overall economic output through a multiplier effect. Building on work within the Caribbean structuralist tradition, this paper presents a demand-driven model that includes capital accumulation and external debt. Given the limited data available for many small island states, the model explicitly represents the external macroeconomic balance. An aggregate representation of the national economy is derived formally from a two-sector model, following models of a petroleum exporting country developed Seers and Bruce and Girvan. The model's performance was evaluated against the historical performance of the Caribbean countries of Barbados, Jamaica and Trinidad and Tobago.

Purpose The use of socio-economic scenarios in small island developing states (SIDS) when assessing, and planning for, the impacts of global changes on national socioeconomic and environmental systems is still in its infancy. The research conducts a cross-scale foresight scenario exercise to produce regional scenarios and national storylines for Caribbean islands that are of “partial” consistency to the shared socioeconomic pathways (SSPs) and representative concentration pathways (RCPs) and shows how future socioeconomic and climatic changes can be applied to inform natural resource management decisions. Design/methodology/approach To develop the scenarios, the study uses a three-staged linking process using mixed methods to “triangulate” each technique to compensate for weaknesses of one method by introducing a complementary method at each stage. A participatory-expert stepwise approach with feedback loops is used and complemented with a climate sensitive tourism water demand model. Findings Four regional exploratory socio-economic scenarios were constructed that are partially consistent with global scenarios. In addition, national storylines for four island states were developed based on the regional scenarios. Using RCP 4.5 hotel water demand in Barbados is estimated under three of the regional scenarios based on compatibility. The results indicate there is a 17% difference between the highest and lowest estimated water demand, indicating the effect of varying socio-economic conditions on water demand. Originality/value The paper contributes to the literature by presenting regional socio-economic scenarios, specifically for SIDS, that are partially consistent with both global climatic RCPs and SSPs using a cross-scale approach. The scenarios are then used to demonstrate how future socio-economic pathways impact on freshwater demand.