75 research outputs found

    A decade of movement ecology

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    Movement is fundamental to life, shaping population dynamics, biodiversity patterns, and ecosystem structure. Recent advances in tracking technology have enabled fundamental questions about movement to be tackled, leading to the development of the movement ecology framework (MEF), considered a milestone in the field [1]. The MEF introduced an integrative theory of organismal movement, linking internal state, motion capacity and navigation capacity to external factors. Here, a decade later, we investigated the current state of research in the field. Using a text mining approach on >8000 peer-reviewed papers in movement ecology, we explored the main research topics, evaluated the impact of the MEF, and assessed changes in the use of technological devices, software and statistical methods. The number of publications has increased considerably and there have been major technological changes in the past decade (i.e.~increased use of GPS devices, accelerometers and video cameras, and a convergence towards R), yet we found that research focuses on the same questions, specifically, on the effect of environmental factors on movement and behavior. In practice, it appears that movement ecology research does not reflect the MEF. We call on researchers to transform the field from technology-driven to embrace interdisciplinary collaboration, in order to reveal key processes underlying movement (e.g.~navigation), as well as evolutionary, physiological and life-history consequences of particular strategies

    Analysis of Movement Recursions to Detect Reproductive Events and Estimate Their Fate in Central Place Foragers

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    Background Recursive movement patterns have been used to detect behavioral structure within individual movement trajectories in the context of foraging ecology, home-ranging behavior, and predator avoidance. Some animals exhibit movement recursions to locations that are tied to reproductive functions, including nests and dens; while existing literature recognizes that, no method is currently available to explicitly target different types of revisited locations. Moreover, the temporal persistence of recursive movements to a breeding location can carry information regarding the fate of breeding attempts, but it has never been used as a metric to quantify recursive movement patterns. Here, we introduce a method to locate breeding attempts and estimate their fate from GPS-tracking data of central place foragers. We tested the performance of our method in three bird species differing in breeding ecology (wood stork (Mycteria americana), lesser kestrel (Falco naumanni), Mediterranean gull (Ichthyaetus melanocephalus)) and implemented it in the R package ‘nestR’. Methods We identified breeding sites based on the analysis of recursive movements within individual tracks. Using trajectories with known breeding attempts, we estimated a set of species-specific criteria for the identification of nest sites, which we further validated using non-reproductive individuals as controls. We then estimated individual nest survival as a binary measure of reproductive fate (success, corresponding to fledging of at least one chick, or failure) from nest-site revisitation histories during breeding attempts, using a Bayesian hierarchical modeling approach that accounted for temporally variable revisitation patterns, probability of visit detection, and missing data. Results Across the three species, positive predictive value of the nest-site detection algorithm varied between 87 and 100% and sensitivity between 88 and 92%, and we correctly estimated the fate of 86–100% breeding attempts. Conclusions By providing a method to formally distinguish among revisited locations that serve different ecological functions and introducing a probabilistic framework to quantify temporal persistence of movement recursions, we demonstrated how the analysis of recursive movement patterns can be applied to estimate reproduction in central place foragers. Beyond avian species, the principles of our method can be applied to other central place foraging breeders such as denning mammals. Our method estimates a component of individual fitness from movement data and will help bridge the gap between movement behavior, environmental factors, and their fitness consequences

    Navigating through the r packages for movement

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    Case No. 900052-CA Category No. 14b APPEAL FROM AN ORDER OF SUMMARY JUDGMENT AND DISMISSAL OF COMPLAINT WITH PREJUDICE OF THE SECOND JUDICIAL DISTRICT COURT FOR DAVIS COUNTY, STATE OF UTAH JUDGE DOUGLAS L. CORNABY REPLY BRIEF OF APPELLANT

    Complementary and alternative medicine use in glioma patients in France

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    PURPOSE Complementary and alternative medicine (CAM) use increases in cancer patients, including adult patients with diffuse gliomas. METHODS Questionnaires addressing CAM use were distributed to adult patients with gliomas of WHO grades II-IV and ECOG performance score of 0-2 during hospital visits and filled in anonymously. The study was conducted in nine centers in France from May 2017 to May 2018. Descriptive cohort analyses and comparative analyses according to gender, age, WHO grade, and recurrent versus newly diagnosed disease were conducted. RESULTS Two hundred twenty-seven questionnaires were collected; 135 patients (59%) were male. Median age was 48 years, 105 patients (46%) declared having glioblastoma, 99 patients (43%) declared having recurrent disease. Hundred-three patients (45%) had modified their alimentary habits after the glioma diagnosis. At the time of the questionnaire, 100 patients (44%) were on complementary treatment, mainly vitamins and food supplements, and 73 patients (32%) used alternative medicine approaches, mainly magnetism and acupuncture. In total, 154 patients (68%) declared using at least one of these approaches. Expenditures exceeding 100 € per month were reported by users in 14% for modification of alimentary habits, in 25% for complementary treatment, and in 18% for alternative medicines. All approaches were commonly considered as improving quality of life and experienced as efficient, notably those associated with more expenditures. CONCLUSIONS CAM are frequently used by glioma patients in France. Underlying needs and expectations, as well as potential interactions with tumor-specific treatments, and financial and quality of life burden, should be discussed with patients and caregivers

    Recent trends in movement ecology of animals and human mobility

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    Movement is fundamental to life, shaping population dynamics, biodiversity patterns, and ecosystem structure. In 2008, the movement ecology framework (MEF Nathan et al. in PNAS 105(49):19052–19059, 2008) introduced an integrative theory of organismal movement—linking internal state, motion capacity, and navigation capacity to external factors—which has been recognized as a milestone in the field. Since then, the study of movement experienced a technological boom, which provided massive quantities of tracking data of both animal and human movement globally and at ever finer spatio-temporal resolutions. In this work, we provide a quantitative assessment of the state of research within the MEF, focusing on animal movement, including humans and invertebrates, and excluding movement of plants and microorganisms. Using a text mining approach, we digitally scanned the contents of [Formula: see text] papers from 2009 to 2018 available online, identified tools and methods used, and assessed linkages between all components of the MEF. Over the past decade, the publication rate has increased considerably, along with major technological changes, such as an increased use of GPS devices and accelerometers and a majority of studies now using the R software environment for statistical computing. However, animal movement research still largely focuses on the effect of environmental factors on movement, with motion and navigation continuing to receive little attention. A search of topics based on words featured in abstracts revealed a clustering of papers among marine and terrestrial realms, as well as applications and methods across taxa. We discuss the potential for technological and methodological advances in the field to lead to more integrated and interdisciplinary research and an increased exploration of key movement processes such as navigation, as well as the evolutionary, physiological, and life-history consequences of movement

    Examining sources of land tenure (in)security. A focus on authority relations, state politics, social dynamics and belonging

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    This article reviews the current state of literature on the notion of security of tenure of land. This examination is topical as tenure security has become a key objective for land policies and development interventions. While tenure security is widely defined by people’s perceptions, land policies tend to address it through the registration and administration of land rights. The article argues that these practices ignore the complexity of the sources of tenure (in)security. Building on critical development literature of political ecology, social anthropology and political science, these sources are identified as stemming from the politics of land and linked to authority relations, state politics, social dynamics and belonging. The article concludes that their consideration enables us to contextualise perceptions of tenure security and to conceive practices for securing tenure

    Evaluating the data quality of iNaturalist termite records.

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    Citizen science (CS) contributes to the knowledge about species distributions, which is a critical foundation in the studies of invasive species, biological conservation, and response to climatic change. In this study, we assessed the value of CS for termites worldwide. First, we compared the abundance and species diversity of geo-tagged termite records in iNaturalist to that of the University of Florida termite collection (UFTC) and the Global Biodiversity Information Facility (GBIF). Second, we quantified how the combination of these data sources affected the number of genera that satisfy data requirements for ecological niche modeling. Third, we assessed the taxonomic correctness of iNaturalist termite records in the Americas at the genus and family level through expert review based on photo identification. Results showed that iNaturalist records were less abundant than those in the UFTC and in GBIF, although they complemented the latter two in selected world regions. A combination of GBIF and the UFTC led to a significant increase in the number of termite genera satisfying the abundance criterion for niche modeling compared to either of those two sources alone, whereas adding iNaturalist observations as a third source only had a moderate effect on the number of termite genera satisfying that criterion. Although research grade observations in iNaturalist require a community-supported and agreed upon identification (ID) below the family taxonomic rank, our results indicated that iNaturalist data do not exhibit a higher taxonomic classification accuracy when they are designated research grade. This means that non-research grade observations can be used to more completely map the presence of termite locations in certain geographic locations without significantly jeopardizing data quality. We concluded that CS termite observation records can, to some extent, complement expert termite collections in terms of geographic coverage and species diversity. Based on recent data contribution patterns in CS data, the role of CS termite contributions is expected to grow significantly in the near future

    Sustained Response of a Clivus Chordoma to Erlotinib after Imatinib Failure

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    Chordoma is a rare malignant axial tumour that develops from embryonic remnants of the notochord. Surgery and irradiation are the standard initial treatment. However, local recurrence is frequent and cytotoxic chemotherapy is inefficient. Transient activity of imatinib, a platelet-derived growth factor receptor inhibitor, was described in a phase II study. Activity of epidermal growth factor receptor (EGFR) inhibitors (erlotinib, gefitinib) has also been shown in a few recent case reports. We describe a 68-year-old female in whom clivus chordoma recurred after surgery and radiotherapy. The tumour progressed despite imatinib treatment. A partial and sustained response (28+ months) was obtained using erlotinib, an EGFR inhibitor. Erlotinib should be evaluated in a prospective trial investigating new potential therapies against recurrent chordoma
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