7 research outputs found

    Understanding morphological variation in the extant koala as a framework for identification of species boundaries in extinct koalas (Phascolarctidae; Marsupialia)

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    We document morphological variation (both geographical and sexual) in the dentition of the extant koala, Phascolarctos cinereus, in order to facilitate discrimination of species boundaries in extinct phascolarctids. Considerable variation is evident in dental structures previously used to diagnose several phascolarctid fossil species. Consistent patterns of morphological variation are not evident between sexes or geographic regions, with variation as great between samples as within them. Metric variation is evident between the sexes in upper molar dimensions with Victorian (southern) males significantly larger than Victorian females, although this is not reflected in lower molar dimensions or in the Queensland (northern) sample. Male koalas from southern populations generally display significantly larger molars than their northern counterparts; however this trend is not evident in female upper molar dimensions. In both males and females, some, but not all, lower molar dimensions are larger in southern populations than northern. In light of these results, a systematic revision of species of Litokoala suggests L. dicktedfordi' is a junior synonym of L. kutjamarpensis, and the poorly known L. thurmerae is regarded to be a nomen dubium. Further, we describe a partial cranium of a new species of koala from Early Miocene sediments in the Riversleigh World Heritage Area, northern Australia. Litokoala dicksmithi sp. nov. is the fifth koala species recorded from the diverse rainforest assemblages of Riversleigh and the third species referred to the Oligo-Miocene genus Litokoala. Aspects of cranial morphology, including a shortened robust rostrum and broad, irregular nasal aperture, confirm placement of Litokoala as sister taxon to the modern genus Phascolarctos. Relatively large orbits and small body size suggest the possibility that L. dicksmithi was nocturnal, had enhanced visual acuity, and was a more agile arboreal species than the relatively sedentary extant koala

    Evaluating the potential of the forthcoming commercial US high-resolution satellite sensor imagery at the Ordnance Survey

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    As the National Mapping Agency of Great Britain, the Ordinance Survey® (OS) is driven by a need to reduce costs and commercialize operations, and as such has been investigating photogrammetric methods to improve existing products, streamline existing production, and increase the current portfolio of products. Over the last 18 months, the OS has been involved in a major research project to tackle these issues through an evaluation of the forthcoming commercial U.S. high spatial resolution satellite sensors which are offering 1-m panchromatic and 4-m multispectral spatial resolutions. Work has focused on improving the existing National Height Dataset (NHD), reducing the cost of photogrammetric survey, automatic topographic feature change detection, production of DEMs; three-dimensional (3D) urban models, and land-use classification. Results from the project using simulated imagery indicate that it would have potential within the OS in all areas evaluated. The work now needs to be followed up when real high spatial resolution satellite imagery becomes commercially available

    Sex pheromones of rice moth,Corcyra cephalonica Stainton

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    International audienceBehavioral observations of the rice moth (Corcyra cephalonica, Pyralidae, Galleriinae) in the laboratory have shown that a male wing-gland pheromone induces attraction of female moths. This pheromone was identified as a blend of (E,E) and (Z,E)-farnesal. Wing-gland extracts or synthetic compounds were shown to be attractive to females by inducing walking

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical science. © The Author(s) 2019. Published by Oxford University Press
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