Dataset Information

Toward the quantification of a conceptual framework for movement ecology using circular statistical modeling.

ABSTRACT: To analyze an animal's movement trajectory, a basic model is required that satisfies the following conditions: the model must have an ecological basis and the parameters used in the model must have ecological interpretations, a broad range of movement patterns can be explained by that model, and equations and probability distributions in the model should be mathematically tractable. Random walk models used in previous studies do not necessarily satisfy these requirements, partly because movement trajectories are often more oriented or tortuous than expected from the models. By improving the modeling for turning angles, this study aims to propose a basic movement model. On the basis of the recently developed circular auto-regressive model, we introduced a new movement model and extended its applicability to capture the asymmetric effects of external factors such as wind. The model was applied to GPS trajectories of a seabird (Calonectris leucomelas) to demonstrate its applicability to various movement patterns and to explain how the model parameters are ecologically interpreted under a general conceptual framework for movement ecology. Although it is based on a simple extension of a generalized linear model to circular variables, the proposed model enables us to evaluate the effects of external factors on movement separately from the animal's internal state. For example, maximum likelihood estimates and model selection suggested that in one homing flight section, the seabird intended to fly toward the island, but misjudged its navigation and was driven off-course by strong winds, while in the subsequent flight section, the seabird reset the focal direction, navigated the flight under strong wind conditions, and succeeded in approaching the island.

SUBMITTER: Shimatani IK

PROVIDER: S-EPMC3511459 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

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Toward the quantification of a conceptual framework for movement ecology using circular statistical modeling.

Shimatani Ichiro Ken IK Yoda Ken K Katsumata Nobuhiro N Sato Katsufumi K

PloS one 20121130 11

To analyze an animal's movement trajectory, a basic model is required that satisfies the following conditions: the model must have an ecological basis and the parameters used in the model must have ecological interpretations, a broad range of movement patterns can be explained by that model, and equations and probability distributions in the model should be mathematically tractable. Random walk models used in previous studies do not necessarily satisfy these requirements, partly because movement ...[more]

PMID: 23226261

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Project description:IntroductionCountries are working hard to improve access to healthcare through Universal Healthcare Coverage. To genuinely address the problems of healthcare access, we need to recognize all the dimensions and complexities of healthcare access. Levesque's Conceptual Framework of Access to Health introduced in 2013 provides an interesting and comprehensive perspective through the five dimensions of access and the five abilities of the population to access healthcare. The objectives of this paper are to identify and analyze all empirical studies that applied Levesque's conceptual framework for access to healthcare and to explore the experiences and challenges of researchers who used this framework in developing tools for assessing access.MethodsA scoping review was conducted by searching through four databases, for studies citing Levesque et al. 2013 to select all empirical studies focusing on healthcare access that applied the framework. An initial 1838 documents underwent title screening, followed by abstract screening, and finally full text screening by two independent reviewers. Authors of studies identified from the scoping review were also interviewed.ResultsThere were 31 studies identified on healthcare access using the Levesque framework either a priori, to develop assessment tool/s (11 studies), or a posteriori, to organize and analyze collected data (20 studies). From the tools used, 147 unique questions on healthcare access were collected, 91 of these explored dimensions of access while 56 were about abilities to access. Those that were designed from the patient's perspective were 73%, while 20% were for health providers, and 7% were addressed to both. Interviews from seven out of the 26 authors, showed that while there were some challenges such as instances of categorization difficulty and unequal representation of dimensions and abilities, the overall experience was positive.ConclusionLevesque's framework has been successfully used in research that explored, assessed, and measured access in various healthcare services and settings. The framework allowed researchers to comprehensively assess the complex and dynamic process of access both in the health systems and the population contexts. There is still potential room for improvement of the framework, particularly the incorporation of time-related elements of access.

Dataset Information

Toward the quantification of a conceptual framework for movement ecology using circular statistical modeling.

Publications

Toward the quantification of a conceptual framework for movement ecology using circular statistical modeling.

Similar Datasets

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