1,321 research outputs found

    Robotic ecology: Tracking small dynamic animals with an autonomous aerial vehicle

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    Copyright © 2018 The Authors, some rights reserved. Understanding animal movements that underpin ecosystem processes is fundamental to ecology. Recent advances in animal tags have increased the ability to remotely locate larger species; however, this technology is not suitable for up to 70% of the world’s bird and mammal species. The most widespread technique for tracking small animals is to manually locate low-power radio transmitters from the ground with handheld equipment. Despite this labor-intensive technique being used for decades, efforts to reduce or automate this process have had limited success. Here, we present an approach for tracking small radio-tagged animals by using an autonomous and lightweight aerial robot. We present experimental results where we used the robot to locate critically endangered swift parrots (Lathamus discolor) within their winter range. The system combines a miniaturized sensor with newly developed estimation algorithms to yield unambiguous bearing- and range-based measurements with associated measures of uncertainty. We incorporated these measurements into Bayesian data fusion and information-based planning algorithms to control the position of the robot as it collected data. We report estimated positions that lie within about 50 meters of the true positions of the birds on average, which are sufficiently accurate for recapture or observation. Further, in comparison with experienced human trackers from locations where the signal was detectable, the robot produced a correct estimate as fast or faster than the human. These results provide validation of robotic systems for wildlife radio telemetry and suggest a way for widespread use as human-assistive or autonomous devices

    Online localization of radio-tagged wildlife with an autonomous aerial robot system

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    © 2015, MIT Press Journals. All rights reserved. The application of autonomous robots to efficiently locate small wildlife species has the potential to provide significant ecological insights not previously possible using traditional land-based survey techniques, and a basis for improved conservation policy and management. We present an approach for autonomously localizing radio-tagged wildlife using a small aerial robot. We present a novel two-point phased array antenna system that yields unambiguous bearing measurements and an associated uncertainty measure. Our estimation and information-based planning algorithms incorporate this bearing uncertainty to choose observation points that improve confidence in the location estimate. These algorithms run online in real time and we report experimental results that show successful autonomous localization of stationary radio tags and live radio-tagged birds

    Settlement and Swift Parrots — historic and ongoing habitat loss for a critically endangered species (1788–2016)

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    The Swift Parrot, Lathamus discolor White, 1790, was among the first of Australia’s birds to be scientifically described and illustrated following European settlement in 1788. Within 60 years of settlement, key habitat throughout the species’ range was being lost. A unique compilation of historical and recent information on Swift Parrot habitat loss demonstrates how past events have rendered this species Critically Endangered. A crucial aspect of the loss of habitat is the speed and spatial extent over which it occurred. The most extensive loss happened during colonial times however, losses continue to this day due to various government land management policies and practices. Consequently, the Swift Parrot remains the subject of an ongoing national recovery program and its future is far from secure

    Screening and assessment tools for gaming disorder: A comprehensive systematic review

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    The inclusion of gaming disorder (GD) as an official diagnosis in the ICD-11 was a significant milestone for the field. However, the optimal measurement approaches for GD are currently unclear. This comprehensive systematic review aimed to identify and evaluate all available English-language GD tools and their corresponding evidence. A search of PsychINFO, PsychArticles, ScienceDirect, Scopus, Web of Science, and Google Scholar identified 32 tools employed in 320 studies (N = 462,249 participants). The evaluation framework examined tools in relation to: (1) conceptual and practical considerations; (2) alignment with DSM-5 and ICD-11 criteria; (3) type and quantity of studies and samples; and (4) psychometric properties. The evaluation showed that GD instrumentation has proliferated, with 2.5 tools, on average, published annually since 2013. Coverage of DSM-5 and ICD-11 criteria was inconsistent, especially for the criterion of continued use despite harm. Tools converge on the importance of screening for impaired control over gaming and functional impairment. Overall, no single tool was found to be clearly superior, but the AICA-Sgaming, GAS-7, IGDT-10, IGDS9-SF, and Lemmens IGD-9 scales had greater evidential support for their psychometric properties. The GD field would benefit from a standard international tool to identify gaming-related harms across the spectrum of maladaptive gaming behaviors.Peer reviewedFinal Accepted Versio

    Does clinical management improve outcomes following self-Harm? Results from the multicentre study of self-harm in England

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    Background Evidence to guide clinical management of self-harm is sparse, trials have recruited selected samples, and psychological treatments that are suggested in guidelines may not be available in routine practice. Aims To examine how the management that patients receive in hospital relates to subsequent outcome. Methods We identified episodes of self-harm presenting to three UK centres (Derby, Manchester, Oxford) over a 10 year period (2000 to 2009). We used established data collection systems to investigate the relationship between four aspects of management (psychosocial assessment, medical admission, psychiatric admission, referral for specialist mental health follow up) and repetition of self-harm within 12 months, adjusted for differences in baseline demographic and clinical characteristics. Results 35,938 individuals presented with self-harm during the study period. In two of the three centres, receiving a psychosocial assessment was associated with a 40% lower risk of repetition, Hazard Ratios (95% CIs): Centre A 0.99 (0.90–1.09); Centre B 0.59 (0.48–0.74); Centre C 0.59 (0.52–0.68). There was little indication that the apparent protective effects were mediated through referral and follow up arrangements. The association between psychosocial assessment and a reduced risk of repetition appeared to be least evident in those from the most deprived areas. Conclusion These findings add to the growing body of evidence that thorough assessment is central to the management of self-harm, but further work is needed to elucidate the possible mechanisms and explore the effects in different clinical subgroups

    Virtual Northern Analysis of the Human Genome

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    BACKGROUND: We applied the Virtual Northern technique to human brain mRNA to systematically measure human mRNA transcript lengths on a genome-wide scale. METHODOLOGY/PRINCIPAL FINDINGS: We used separation by gel electrophoresis followed by hybridization to cDNA microarrays to measure 8,774 mRNA transcript lengths representing at least 6,238 genes at high (>90%) confidence. By comparing these transcript lengths to the Refseq and H-Invitational full-length cDNA databases, we found that nearly half of our measurements appeared to represent novel transcript variants. Comparison of length measurements determined by hybridization to different cDNAs derived from the same gene identified clones that potentially correspond to alternative transcript variants. We observed a close linear relationship between ORF and mRNA lengths in human mRNAs, identical in form to the relationship we had previously identified in yeast. Some functional classes of protein are encoded by mRNAs whose untranslated regions (UTRs) tend to be longer or shorter than average; these functional classes were similar in both human and yeast. CONCLUSIONS/SIGNIFICANCE: Human transcript diversity is extensive and largely unannotated. Our length dataset can be used as a new criterion for judging the completeness of cDNAs and annotating mRNA sequences. Similar relationships between the lengths of the UTRs in human and yeast mRNAs and the functions of the proteins they encode suggest that UTR sequences serve an important regulatory role among eukaryotes

    Nautilus at Risk – Estimating Population Size and Demography of Nautilus pompilius

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    The low fecundity, late maturity, long gestation and long life span of Nautilus suggest that this species is vulnerable to over-exploitation. Demand from the ornamental shell trade has contributed to their rapid decline in localized populations. More data from wild populations are needed to design management plans which ensure Nautilus persistence. We used a variety of techniques including capture-mark-recapture, baited remote underwater video systems, ultrasonic telemetry and remotely operated vehicles to estimate population size, growth rates, distribution and demographic characteristics of an unexploited Nautilus pompilius population at Osprey Reef (Coral Sea, Australia). We estimated a small and dispersed population of between 844 and 4467 individuals (14.6–77.4 km−2) dominated by males (83∶17 male∶female) and comprised of few juveniles (<10%).These results provide the first Nautilid population and density estimates which are essential elements for long-term management of populations via sustainable catch models. Results from baited remote underwater video systems provide confidence for their more widespread use to assess efficiently the size and density of exploited and unexploited Nautilus populations worldwide

    Annotation of two large contiguous regions from the Haemonchus contortus genome using RNA-seq and comparative analysis with Caenorhabditis elegans

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    The genomes of numerous parasitic nematodes are currently being sequenced, but their complexity and size, together with high levels of intra-specific sequence variation and a lack of reference genomes, makes their assembly and annotation a challenging task. Haemonchus contortus is an economically significant parasite of livestock that is widely used for basic research as well as for vaccine development and drug discovery. It is one of many medically and economically important parasites within the strongylid nematode group. This group of parasites has the closest phylogenetic relationship with the model organism Caenorhabditis elegans, making comparative analysis a potentially powerful tool for genome annotation and functional studies. To investigate this hypothesis, we sequenced two contiguous fragments from the H. contortus genome and undertook detailed annotation and comparative analysis with C. elegans. The adult H. contortus transcriptome was sequenced using an Illumina platform and RNA-seq was used to annotate a 409 kb overlapping BAC tiling path relating to the X chromosome and a 181 kb BAC insert relating to chromosome I. In total, 40 genes and 12 putative transposable elements were identified. 97.5% of the annotated genes had detectable homologues in C. elegans of which 60% had putative orthologues, significantly higher than previous analyses based on EST analysis. Gene density appears to be less in H. contortus than in C. elegans, with annotated H. contortus genes being an average of two-to-three times larger than their putative C. elegans orthologues due to a greater intron number and size. Synteny appears high but gene order is generally poorly conserved, although areas of conserved microsynteny are apparent. C. elegans operons appear to be partially conserved in H. contortus. Our findings suggest that a combination of RNA-seq and comparative analysis with C. elegans is a powerful approach for the annotation and analysis of strongylid nematode genomes

    Assessing the conservation value of waterbodies: the example of the Loire floodplain (France)

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    In recent decades, two of the main management tools used to stem biodiversity erosion have been biodiversity monitoring and the conservation of natural areas. However, socio-economic pressure means that it is not usually possible to preserve the entire landscape, and so the rational prioritisation of sites has become a crucial issue. In this context, and because floodplains are one of the most threatened ecosystems, we propose a statistical strategy for evaluating conservation value, and used it to prioritise 46 waterbodies in the Loire floodplain (France). We began by determining a synthetic conservation index of fish communities (Q) for each waterbody. This synthetic index includes a conservation status index, an origin index, a rarity index and a richness index. We divided the waterbodies into 6 clusters with distinct structures of the basic indices. One of these clusters, with high Q median value, indicated that 4 waterbodies are important for fish biodiversity conservation. Conversely, two clusters with low Q median values included 11 waterbodies where restoration is called for. The results picked out high connectivity levels and low abundance of aquatic vegetation as the two main environmental characteristics of waterbodies with high conservation value. In addition, assessing the biodiversity and conservation value of territories using our multi-index approach plus an a posteriori hierarchical classification methodology reveals two major interests: (i) a possible geographical extension and (ii) a multi-taxa adaptation

    Prioritization of fish communities with a view to conservation and restoration on a large scale European basin, the Loire (France)

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    The hierarchical organization of important sites for the conservation or the restoration of fish communities is a great challenge for managers, especially because of financial or time constraints. In this perspective, we developed a methodology, which is easy to implement in different locations. Based on the fish assemblage characteristics of the Loire basin (France), we created a synthetic conservation value index including the rarity, the conservation status and the species origin. The relationship between this new synthetic index and the Fish-Based Index allowed us to establish a classification protocol of the sites along the Loire including fish assemblages to be restored or conserved. Sites presenting disturbed fish assemblages, a low rarity index, few threatened species, and a high proportion of non-native species were considered as important for the restoration of fish biodiversity. These sites were found mainly in areas where the assemblages are typical of the bream zone, e.g. with a higher number of eurytopic and limnophilic species. On the contrary, important sites for conservation were defined as having an important conservation potential (high RI, a lot of threatened species, and few nonnatives fish species) and an undisturbed fish assemblage similar to the expected community if habitats are undisturbed. Important sites for conservation were found in the Loire basin’s medium reaches which host assemblages typical for the grayling and the barbell zones, e.g. with a higher number of rheophilic species. The synthetic conservation value index could be adapted and completed with other criteria according to management priorities and capacities
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