148 research outputs found

    Impact perceptuel d'une mise à zéro des segments plosifs de parole

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    En traitement du signal audio, les plosives sont des sons de parole très importants au regard de l’intelligibilité et de la qualité. Les plosives sont cependant difficiles à modéliser à l’aide des techniques usuelles (prédiction linéaire et codage par transformée), à cause de leur dynamique propre importante et à cause de leur nature non prédictible. Cette étude présente un exemple de système complet capable de détecter, segmenter, et altérer les plosives dans un flux de parole. Ce système est utilisé afin de vérifier la validité de l’hypothèse suivante : La phase d’éclatement (de burst) des plosives peut être mise à zéro, de façon perceptuellement équivalente. L’impact sur la qualité subjective de cette transformation est évalué sur une banque de phrases enregistrées. Les résultats de cette altération hautement destructive des signaux tendent à montrer que l’impact perceptuel est mineur. Les implications de ces résultats pour le codage de la parole sont abordées

    The Conserved Candida albicans CA3427 Gene Product Defines a New Family of Proteins Exhibiting the Generic Periplasmic Binding Protein Structural Fold

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    Nosocomial diseases due to Candida albicans infections are in constant rise in hospitals, where they cause serious complications to already fragile intensive care patients. Antifungal drug resistance is fast becoming a serious issue due to the emergence of strains resistant to currently available antifungal agents. Thus the urgency to identify new potential protein targets, the function and structure of which may guide the development of new antifungal drugs. In this context, we initiated a comparative genomics study in search of promising protein coding genes among the most conserved ones in reference fungal genomes. The CA3427 gene was selected on the basis of its presence among pathogenic fungi contrasting with its absence in the non pathogenic Saccharomyces cerevisiae. We report the crystal 3D-structure of the Candida albicans CA3427 protein at 2.1 Å resolution. The combined analysis of its sequence and structure reveals a structural fold originally associated with periplasmic binding proteins. The CA3427 structure highlights a binding site located between the two protein domains, corresponding to a sequence segment conserved among fungi. Two crystal forms of CA3427 were found, suggesting that the presence or absence of a ligand at the proposed binding site might trigger a “Venus flytrap” motion, coupled to the previously described activity of bacterial periplasmic binding proteins. The conserved binding site defines a new subfamily of periplasmic binding proteins also found in many bacteria of the bacteroidetes division, in a choanoflagellate (a free-living unicellular and colonial flagellate eukaryote) and in a placozoan (the closest multicellular relative of animals). A phylogenetic analysis suggests that this gene family originated in bacteria before its horizontal transfer to an ancestral eukaryote prior to the radiation of fungi. It was then lost by the Saccharomycetales which include Saccharomyces cerevisiae

    The compensatory potential of increased immigration following intensive American mink population control is diluted by male-biased dispersal

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    Attempts to mitigate the impact of invasive species on native ecosystems increasingly target large land masses where control, rather than eradication, is the management objective. Depressing numbers of invasive species to a level where their impact on native biodiversity is tolerable requires overcoming the impact of compensatory immigration from non-controlled portions of the landscape. Because of the expected scale-dependency of dispersal, the overall size of invasive species management areas relative to the dispersal ability of the controlled species will determine the size of any effectively conserved core area unaffected by immigration from surrounding areas. However, when dispersal is male-biased, as in many mammalian invasive carnivores, males may be overrepresented amongst immigrants, reducing the potential growth rate of invasive species populations in re-invaded areas. Using data collected from a project that gradually imposed spatially comprehensive control on invasive American mink (Neovison vison) over a 10,000 km2 area of NE Scotland, we show that mink captures were reduced to almost zero in 3 years, whilst there was a threefold increase in the proportion of male immigrants. Dispersal was often long distance and linking adjacent river catchments, asymptoting at 38 and 31 km for males and females respectively. Breeding and dispersal were spatially heterogeneous, with 40 % of river sections accounting for most captures of juvenile (85 %), adult female (65 %) and immigrant (57 %) mink. Concentrating control effort on such areas, so as to turn them into “attractive dispersal sinks” could make a disproportionate contribution to the management of recurrent re-invasion of mainland invasive species management areas

    Cryptic Diversity in Indo-Pacific Coral-Reef Fishes Revealed by DNA-Barcoding Provides New Support to the Centre-of-Overlap Hypothesis

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    Diversity in coral reef fishes is not evenly distributed and tends to accumulate in the Indo-Malay-Philippines Archipelago (IMPA). The comprehension of the mechanisms that initiated this pattern is in its infancy despite its importance for the conservation of coral reefs. Considering the IMPA either as an area of overlap or a cradle of marine biodiversity, the hypotheses proposed to account for this pattern rely on extant knowledge about taxonomy and species range distribution. The recent large-scale use of standard molecular data (DNA barcoding), however, has revealed the importance of taking into account cryptic diversity when assessing tropical biodiversity. We DNA barcoded 2276 specimens belonging to 668 coral reef fish species through a collaborative effort conducted concomitantly in both Indian and Pacific oceans to appraise the importance of cryptic diversity in species with an Indo-Pacific distribution range. Of the 141 species sampled on each side of the IMPA, 62 presented no spatial structure whereas 67 exhibited divergent lineages on each side of the IMPA with K2P distances ranging between 1% and 12%, and 12 presented several lineages with K2P distances ranging between 3% and 22%. Thus, from this initial pool of 141 nominal species with Indo-Pacific distribution, 79 dissolved into 165 biological units among which 162 were found in a single ocean. This result is consistent with the view that the IMPA accumulates diversity as a consequence of its geological history, its location on the junction between the two main tropical oceans and the presence of a land bridge during glacial times in the IMPA that fostered allopatric divergence and secondary contacts between the Indian and Pacific oceans

    Prediction of survival with second-line therapy in biliary tract cancer: Actualisation of the AGEO CT2BIL cohort and European multicentre validations

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    BACKGROUND: The benefit of second-line chemotherapy (L2) over standard first-line (L1) gemcitabine plus cisplatin (GEMCIS) or oxaliplatin (GEMOX) chemotherapy in advanced biliary tract cancer (aBTC) is unclear. Our aim was to identify and validate prognostic factors for overall survival (OS) with L2 in aBTC to guide clinical decisions in this setting. METHODS: We performed a retrospective analysis of four prospective patient cohorts: a development cohort (28 French centres) and three validation cohorts from Italy, UK and France. All consecutive patients with aBTC receiving L2 after GEMCIS/GEMOX L1 between 2003 and 2016 were included. The association of clinicobiological data with OS was investigated in univariate and multivariate Cox analyses. A simple score was derived from the multivariate model. RESULTS: The development cohort included 405 patients treated with L1 GEMOX (91%) or GEMCIS. Of them, 55.3% were men, and median age was 64.8 years. Prior surgical resection was observed in 26.7%, and 94.8% had metastatic disease. Performance status (PS) was 0, 1 and 2 in 17.8%, 52.4% and 29.7%, respectively. Among 22 clinical parameters, eight were associated with OS in univariate analysis. In multivariate analysis, four were independent prognostic factors (p < 0.05): PS, reason for L1 discontinuation, prior resection of primary tumour and peritoneal carcinomatosis. The model had the Harrell's concordance index of 0.655, a good calibration and was validated in the three external cohorts (N = 392). CONCLUSION: We validated previously reported predictive factors of OS with L2 and identified peritoneal carcinomatosis as a new pejorative factor in nearly 800 patients. Our model and score may be useful in daily practice and for future clinical trial design

    Multiple Invasions into Freshwater by Pufferfishes (Teleostei: Tetraodontidae): A Mitogenomic Perspective

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    Pufferfishes of the Family Tetraodontidae are the most speciose group in the Order Tetraodontiformes and mainly inhabit coastal waters along continents. Although no members of other tetraodontiform families have fully discarded their marine lives, approximately 30 tetraodontid species spend their entire lives in freshwaters in disjunct tropical regions of South America, Central Africa, and Southeast Asia. To investigate the interrelationships of tetraodontid pufferfishes and thereby elucidate the evolutionary origins of their freshwater habitats, we performed phylogenetic analysis based on whole mitochondrial genome sequences from 50 tetraodontid species and closely related species (including 31 newly determined sequences). The resulting phylogenies reveal that the family is composed of four major lineages and that freshwater species from the different continents are independently nested in two of the four lineages. A monophyletic origin of the use of freshwater habitats was statistically rejected, and ancestral habitat reconstruction on the resulting tree demonstrates that tetraodontids independently entered freshwater habitats in different continents at least three times. Relaxed molecular-clock Bayesian divergence time estimation suggests that the timing of these invasions differs between continents, occurring at 0–10 million years ago (MA) in South America, 17–38 MA in Central Africa, and 48–78 MA in Southeast Asia. These timings are congruent with geological events that could facilitate adaptation to freshwater habitats in each continent

    Molecular approaches to the diagnosis and monitoring of production diseases in pigs

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    Production disease in pigs is caused by a variety of different pathogens, mainly enteric and respiratory and can result in significant economic loss. Other factors such as stress, poor husbandry and nutrition can also contribute to an animal's susceptibility to disease. Molecular biomarkers of production disease could be of immense value by improving diagnosis and risk analysis to determine best practice with an impact on increased economic output and animal welfare. In addition to the use of multiplex PCR or microarrays to detect individual or mixed pathogens during infection, these technologies can also be used to monitor the host response to infection via gene expression. The patterns of gene expression associated with cellular damage or initiation of the early immune response may indicate the type of pathology and, by extension the types of pathogen involved. Molecular methods can therefore be used to monitor both the presence of a pathogen and the host response to it during production disease. The field of biomarker discovery and implementation is expanding as technologies such as microarrays and next generation sequencing become more common. Whilst a large number of studies have been carried out in human medicine, further work is needed to identify molecular biomarkers in veterinary medicine and in particular those associated with production disease in the pig industry. The pig transcriptome is highly complex and still not fully understood. Further gene expression studies are needed to identify molecular biomarkers which may have predictive value in identifying the environmental, nutritional and other risk factors which are associated with production diseases in pigs

    Future Experiences: Sustainable Development and the Global South

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    The Sustainable Development and the Global South project was jointly conceived by the Innovation School at Glasgow School of Art in partnership with the Sustainable Futures in Africa Network (SFA), and the University of Glasgow. Graduating final year BDes Product Design students from the Innovation School were presented with a challenge-based project to produce a vision of the future based on current trends that relate to Sustainable Development work and the Global South. This project involved working closely with researchers, academics and professionals specialising in human geography, education, health, environment, engineering, cultural practice and community engagement who are part of the Sustainable Futures in Africa Network which includes a Scottish hub, led from the University of Glasgow. Included in the network was a representative from an NGO that builds schools in Malawi, an entrepreneur who runs an ethical clothing company that partners with producers in the Global South, a senior governance officer from the UK Government’s Department for International Development (DFID), a research network administrator, and international graduate students from Africa based at Scottish institutions. In addition to the SFA, external experts from design studio AndThen and GOODD design consultancy were engaged. The objective of this project was to investigate, in both analytical and speculative ways, future forms and functions of Sustainable Development work in relation to the Global South in ten years from now, to develop future scenarios and design the artefacts, services and the experiences associated with these future visions. On completion of the project and learning experience it was intended that the students would be able to recognise and articulate the impact and sustainability of their design propositions, consider the life-cycle of their proposals and the values these might create for the intended users, communities and contexts. The project was completed in January 2020, as the Covid-19 pandemic was just beginning its spread around the world. This unprecedented catastrophe reinforced the importance of supporting those most in need – the citizens of developing regions in the Global South. In April 2020, the heads of all the UN’s major agencies issued an open letter warning of the risks the virus posed to the world’s most vulnerable countries. It called on wealthier nations to increase funding and help to tackle issues such as the cessation of aid as a result of cancelled flights and disrupted supply routes. These and many other concerns highlighted during the crisis are among the topics explored in this project, which feels even more relevant and urgent than when it was initiated in the summer of 2019. One of the most significant societal shifts currently taking place within the field of sustainable development work is its transformation from being understood as a process of growth or, at its most benign, poverty alleviation, to one of community empowerment and civic participation. The public’s role is developing beyond once-passive community members and recipients of aid, into stakeholders valued for their local knowledge, lived experiences, participation in development projects, and contribution towards policy-making and decision-making. This new dynamic is changing the traditional North-South relationship and holds the potential to challenge the geopolitical hegemony of International Development. The impetus for this shift is a decolonial, collaborative approach to development, research and practice; increased local empowerment, and sustainable solutions to problems that are co-created in context with those affected by and affecting the issue in question. This project asked students to consider what happens in this global landscape ten years from now where Sustainable Development has evolved to the extent that new forms of work and communities of practice transform how people engage, learn and interact with each other, with stakeholders and with the global community around them. The brief gave students the opportunity to explore the underlying complexities regarding sustainable futures, the post-colonial dynamic between ‘norths’ and ‘souths’, post-capitalism and human agency, to envision a future world context, develop it as an experiential exhibit, and produce the designed products, services and experiences for the people who might live and work within it. The project was divided into two sections: The first was a collaborative stage where groups of students were assigned a specific domain to collectively research one aspect of the project challenge, these domains included; Health, Energy, Mobility, Economies, Education, Societal Structures and Environment. Each of these domains were examined through the lenses of Social, Technological, Economic, Ethical, Educational, Values, Political, Legal and Ecological (STEEEVPLE) and were tailored in use, as appropriate per domain. The groups focused on researching and exploring their specific domain and gathering as much information and understanding while working with the external experts to further their knowledge. This group stage culminated in a series of Future World exhibits which tangibly manifest the cohort’s collective knowledge and collaborative understanding of what the future could look like in 10 years from now, after exploring the possible consequences of current actions. The second stage saw students explore their individual response to the Future World that had been created in the first stage. Each student developed their own response to the research by iteratively creating a design outcome that was appropriate to the subject matter. This culminated in each student producing a designed product, service or system and a visual communication of the future experience which they had created. A visual summary of the journey and stages (Project Journey Map) is included within the repository and outlines the collaborative process of designing and the innovative nature of the project’s pedagogical model. The project aims to reveal and address the emerging possibilities collaboratively created by Sustainable Development professionals and designers interacting and learning from each other, to present preferable futures which reveal socio-ecological innovations in development work with the Global South in the near future. The deposited materials are arranged as follows: Readme files - two readme files relate to stage one and stage two of the project as outlined above. Project Journey Map - gives a visual overview of the pedagogical structure and timeline of the project. Data folders - the data folders for stage one of the project are named by the domains through which each group explored possible futures. The data folders for stage two of the project are named for the individual students who conducted the work

    Phylotranscriptomic insights into the diversification of endothermic Thunnus tunas

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    Birds, mammals, and certain fishes, including tunas, opahs and lamnid sharks, are endothermic, conserving internally generated, metabolic heat to maintain body or tissue temperatures above that of the environment. Bluefin tunas are commercially important fishes worldwide, and some populations are threatened. They are renowned for their endothermy, maintaining elevated temperatures of the oxidative locomotor muscle, viscera, brain and eyes, and occupying cold, productive high-latitude waters. Less cold-tolerant tunas, such as yellowfin tuna, by contrast, remain in warm-temperate to tropical waters year-round, reproducing more rapidly than most temperate bluefin tuna populations, providing resiliency in the face of large-scale industrial fisheries. Despite the importance of these traits to not only fisheries but also habitat utilization and responses to climate change, little is known of the genetic processes underlying the diversification of tunas. In collecting and analyzing sequence data across 29,556 genes, we found that parallel selection on standing genetic variation is associated with the evolution of endothermy in bluefin tunas. This includes two shared substitutions in genes encoding glycerol-3 phosphate dehydrogenase, an enzyme that contributes to thermogenesis in bumblebees and mammals, as well as four genes involved in the Krebs cycle, oxidative phosphorylation, β-oxidation, and superoxide removal. Using phylogenetic techniques, we further illustrate that the eight Thunnus species are genetically distinct, but found evidence of mitochondrial genome introgression across two species. Phylogeny-based metrics highlight conservation needs for some of these species
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