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A Sensitivity Analysis of the Application of Integrated Species Distribution Models to Mobile Species: A Case Study with the Endangered Baird’s Tapir
- Cody J Schank, Michael V Cove, Marcella J Kelly, Clayton K Nielsen, Georgina O’Farrill, Ninon Meyer, Christopher A Jordan, Jose F González-Maya, Diego J Lizcano, Ricardo Moreno, Michael Dobbins, Victor Montalvo, Juan Carlos Cruz Díaz, Gilberto Pozo Montuy, J Antonio de la Torre, Esteban Brenes-Mora, Margot A Wood, Jessica Gilbert, Walter Jetz, Jennifer A Miller
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- Journal:
- Environmental Conservation / Volume 46 / Issue 3 / September 2019
- Published online by Cambridge University Press:
- 12 June 2019, pp. 184-192
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Species distribution models (SDMs) are statistical tools used to develop continuous predictions of species occurrence. ‘Integrated SDMs’ (ISDMs) are an elaboration of this approach with potential advantages that allow for the dual use of opportunistically collected presence-only data and site-occupancy data from planned surveys. These models also account for survey bias and imperfect detection through the use of a hierarchical modelling framework that separately estimates the species–environment response and detection process. This is particularly helpful for conservation applications and predictions for rare species, where data are often limited and prediction errors may have significant management consequences. Despite this potential importance, ISDMs remain largely untested under a variety of scenarios. We performed an exploration of key modelling decisions and assumptions on an ISDM using the endangered Baird’s tapir (Tapirus bairdii) as a test species. We found that site area had the strongest effect on the magnitude of population estimates and underlying intensity surface and was driven by estimates of model intercepts. Selecting a site area that accounted for the individual movements of the species within an average home range led to population estimates that coincided with expert estimates. ISDMs that do not account for the individual movements of species will likely lead to less accurate estimates of species intensity (number of individuals per unit area) and thus overall population estimates. This bias could be severe and highly detrimental to conservation actions if uninformed ISDMs are used to estimate global populations of threatened and data-deficient species, particularly those that lack natural history and movement information. However, the ISDM was consistently the most accurate model compared to other approaches, which demonstrates the importance of this new modelling framework and the ability to combine opportunistic data with systematic survey data. Thus, we recommend researchers use ISDMs with conservative movement information when estimating population sizes of rare and data-deficient species. ISDMs could be improved by using a similar parameterization to spatial capture–recapture models that explicitly incorporate animal movement as a model parameter, which would further remove the need for spatial subsampling prior to implementation.
Validation of the Bipolar Spectrum Diagnostic Scale in Mexican Psychiatric Patients
- Juan Pablo Sánchez de la Cruz, Ana Fresán, Diana Laura González Moralez, María Lilia López-Narváez, Carlos Alfonso Tovilla-Zarate, Sherezada Pool-García, Isela Juárez-Rojop, Yazmín Hernández-Díaz, Thelma Beatriz González-Castro, María de Lourdes Vera-Campos, Patricia Velázquez-Sánchez
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- Journal:
- The Spanish Journal of Psychology / Volume 21 / 2018
- Published online by Cambridge University Press:
- 27 November 2018, E60
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The Bipolar Spectrum Diagnostic Scale (BSDS) is widely validated and used as a screening tool for bipolar disorder. However, there is no BSDS validated version for its use in Mexican population. The aim of the present study was to examine the BSDS diagnostic capacity, and to evaluate its criterion validity and internal consistency for its use in Mexican psychiatric patients. We recruited 200 patients who attended the psychiatric outpatient service of a Mental Health Specialized Hospital and were screened for bipolar disorder using BSDS. To determine the cut-off point, sensitivity and specificity, we used the SCID–I diagnosis as the gold standard in 100 participants with bipolar disorder and 100 with major depression. Internal consistency according to Cronbach’s coefficient alpha was .81. The area under ROC curve for the overall discriminability of BSDS against the criterion of SCID–I for bipolar disorder was .90. Finally, a cut-off value of 12 reached the most stable sensitivity and specificity, with predictive powers higher than .80. In conclusion, the properties of the scale including internal consistency, sensitivity and specificity, make of BSDS a valuable instrument for screening bipolar disorder in Mexican psychiatric population.