135 research outputs found

    Statistical aspects of carbon fiber risk assessment modeling

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    The probabilistic and statistical aspects of the carbon fiber risk assessment modeling of fire accidents involving commercial aircraft are examined. Three major sources of uncertainty in the modeling effort are identified. These are: (1) imprecise knowledge in establishing the model; (2) parameter estimation; and (3)Monte Carlo sampling error. All three sources of uncertainty are treated and statistical procedures are utilized and/or developed to control them wherever possible

    Empirical comparison of microsatellite and SNP markers to estimate introgression in Apis mellifera mellifera

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    The genetic identity of the dark European honey bee, Apis mellifera mellifera is currently under pressure throughout most of its native range due to large scale commercial trade and replacement with honey bees of mainly Eastern European ancestry (C-lineage: Apis mellifera carnica and Apis mellifera ligustica). To counteract this process, numerous conservation efforts for the protection of native honey bees are sprouting across Europe. For the management of such protected areas and conservation breeding purposes, honey bee subspecies have been routinely identified through wing morphology and through DNA-hybrid tests using microsatellite markers. Currently, new methods are evolving including rapid innovations in single-nucleotide polymorphism (SNP) array technology and high-throughput sequencing. Here, we aim to quantify potential marker-specific biases of hybrid tests and give recommendations for applications in honey bee conservation management. Using an empirical dataset, we first assessed the accuracy of a recently developed reduced SNP panel to estimate C-lineage introgression in A. m. mellifera compared to whole-genome sequence (WGS) data. Using another independent data set, we estimated the differences in admixture proportions between the currently applied hybrid test based on microsatellites and the novel SNP test. We demonstrate that the SNP-based test which contains highly ancestry-informative markers is very efficient to estimate genome-wide ancestry. Furthermore, we report discrepancies between microsatellite and SNP-based admixture proportions. For conservation management, we, therefore, recommend the implementation of SNP-based hybrid tests to maintain high genetic variation within the breeding population, while minimizing influence of introduced honey bees.This work was supported by the Swiss Federal Office for Agriculture FOAG, the Fondation Sur-la-Croix, Basel, and by the 2013–2014 BiodivERsA/FACCE-JPI joint call for research proposals, with the national funders “Fundacžão para a CiĂȘncia e Tecnologia” (Portugal), “Agence Nationale de la Recherche” (France), and “Ministerio de EconomĂ­a y Competividad” (Spain).info:eu-repo/semantics/publishedVersio

    Genetic integrity of the Dark European honey bee (Apis mellifera mellifera) from protected populations: a genome-wide assessment using SNPs and mtDNA sequence data

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    The recognition that the Dark European honey bee, Apis mellifera mellifera, is increasingly threatened in its native range has led to the establishment of conservation programmes and protected areas throughout western Europe. Previous molecular surveys showed that, despite management strategies to preserve the genetic integrity of A. m. mellifera, protected populations had a measurable component of their gene pool derived from commercial C-lineage honey bees. Here we used both sequence data from the tRNAleu-cox2 intergenic mtDNA region and a genome-wide scan, with over 1183 single nucleotide polymorphisms (SNPs), to assess genetic diversity and introgression levels in several protected populations of A. m. mellifera, which were then compared with samples collected from unprotected populations. MtDNA analysis of the protected populations revealed a single colony bearing a foreign haplotype, whereas SNPs showed varying levels of introgression ranging from virtually zero in Norway to about 14% in Denmark. Introgression overall was higher in unprotected (30%) than in protected populations (8%), and is reflected in larger SNP diversity levels of the former, although opposite diversity levels were observed for mtDNA. These results suggest that, despite controlled breeding, some protected populations still require adjustments to the management strategies to further purge foreign alleles, which can be identified by SNPs.Pint

    Investigation of free-living honey bee colonies in Ireland

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    Apis mellifera mellifera (Linnaeus), the Western European honey bee, is considered extinct in the wild over most of its range due largely to hybridisation and replacement by other subspecies, parasitism by Varroa destructor, habitat loss, and effects from agricultural pesticides. The purity of the subspecies within the managed cohort is also at risk over much of its range. Here, we investigated if honey bee colonies inhabited locations outside of the apiaries. In those we located, we explored how long the colony persisted and we investigated the genotypes of the bees using multiple markers. We show here that unmanaged free-living honey bee colonies are present and widespread in Ireland, inhabiting a mixture of nesting habitats with some colonies persisting naturally and unaided over multiple years. Molecular data including mitochondrial, microsatellite, and SNPs evidence indicate that the free-living population sampled is largely comprised of pure A. m. mellifera. Finally, we discuss the implications of conserving free-living A. m. mellifera in Ireland and its possible role in improving the fitness of the managed population both in Ireland and the rest of its European range.We particularly thank the custodians of the free-living honey bee colonies and the Native Irish Honey Bee Society (NIHBS) for their assistance. KAB is a recipient of an Irish Research Council postgraduate fellowship (GOIPG/2015/2767) and a Tony Ryan Postgraduate fellowship. Additional funding was gratefully received from the Department of Agriculture, Food and the Marine [grant number GRGAS 16/GR/09], the Federation of Irish Beekeeping Associations, the Eva Crane Trust [grant number ECTA20160303] and The Native Irish Honey Bee Society. Financial support for DH was provided through the program COMPETE 2020 – POCI (Programa Operacional para a Competividade e Internacionalizac¾~ao) and by Portuguese funds through FCT (Fundac¾~ao para a Ci^encia e a Tecnologia) in the framework of the project BeeHappy (POCI-01-0145-FEDER-029871).info:eu-repo/semantics/publishedVersio

    How the co-benefits of addressing climate change can motivate action across the world

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    It is traditionally thought that the public must be convinced of the reality and importance of anthropogenic climate change in order to take personal and political action. However, convincing the broad public involves overcoming powerful ideological obstacles1-4, and in many places climate change is slipping in public importance5,6. Here we examined whether beliefs about the “co-benefits” of mitigating climate change7 can avoid these obstacles by motivating behavior in both those who accept climate change and those who are unconvinced or unconcerned. We describe an integrative framework for assessing co-benefits8, distinguishing sociological dimensions (e.g., pollution, disease, economic development), and community character (e.g., benevolence, competence). Data from all inhabited continents (24 countries; N=6059), showed that two types of co-benefits, Development (economic and scientific advancement) and Benevolence (a more moral and caring community), rivalled climate change importance in the strength of their relationships with motivations to act. These co-benefits showed effects independent of climate change importance beliefs, and showed similar effects for both climate change believers and skeptics. Communicating these co-benefits of addressing climate change can help motivate action on climate change where traditional approaches have stalled

    Plectin as a prognostic marker in non-metastatic oral squamous cell carcinoma

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    Background: Oral squamous cell carcinoma (OSCC) is associated with a poor 5-year survival rate. In general, patients diagnosed with small tumors have a fairly good prognosis, but some small tumors have an aggressive behavior leading to early death. There are at present no reliable prognostic biomarkers for oral cancers. Thus, to optimize treatment for the individual patient, there is a need for biomarkers that can predict tumor behavior. Method: In the present study the potential prognostic value of plectin was evaluated by a tissue microarray (TMA) based immunohistochemical analysis of primary tumor tissue obtained from a North Norwegian cohort of 115 patients diagnosed with OSCC. The expression of plectin was compared with clinicopathological variables and 5 year survival. Results: The statistical analysis revealed that low expression of plectin in the tumor cells predicted a favorable outcome for patients with non-metastatic disease (p = 0.008). Furthermore, the expression of plectin was found to correlate (p = 0.01) with the expression of uPAR, which we have previously found to be a potential prognostic marker for T1N0 tumors. Conclusions: Our results indicate that low expression of plectin predicts a favorable outcome for patients with non-metastatic OSCC and the expression level of plectin may therefore be used in the treatment stratification for patients with early stage disease

    High sample throughput genotyping for estimating C-lineage introgression in the dark honeybee: an accurate and cost-effective SNP-based tool

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    The natural distribution of the honeybee (Apis mellifera L.) has been changed by humans in recent decades to such an extent that the formerly widest-spread European subspecies, Apis mellifera mellifera, is threatened by extinction through introgression from highly divergent commercial strains in large tracts of its range. Conservation efforts for A. m. mellifera are underway in multiple European countries requiring reliable and cost-efficient molecular tools to identify purebred colonies. Here, we developed four ancestry-informative SNP assays for high sample throughput genotyping using the iPLEX Mass Array system. Our customized assays were tested on DNA from individual and pooled, haploid and diploid honeybee samples extracted from different tissues using a diverse range of protocols. The assays had a high genotyping success rate and yielded accurate genotypes. Performance assessed against whole-genome data showed that individual assays behaved well, although the most accurate introgression estimates were obtained for the four assays combined (117 SNPs). The best compromise between accuracy and genotyping costs was achieved when combining two assays (62 SNPs). We provide a ready-to-use cost-effective tool for accurate molecular identification and estimation oinfo:eu-repo/semantics/publishedVersio

    Co-benefits of addressing climate change can motivate action around the world

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    Personal and political action on climate change is traditionally thought to be motivated by people accepting its reality and importance. However, convincing the public that climate change is real faces powerful ideological obstacles1, 2, 3, 4, and climate change is slipping in public importance in many countries5, 6. Here we investigate a different approach, identifying whether potential co-benefits of addressing climate change7 could motivate pro-environmental behaviour around the world for both those convinced and unconvinced that climate change is real. We describe an integrated framework for assessing beliefs about co-benefits8, distinguishing social conditions (for example, economic development, reduced pollution or disease) and community character (for example, benevolence, competence). Data from all inhabited continents (24 countries; 6,196 participants) showed that two co-benefit types, Development (economic and scientific advancement) and Benevolence (a more moral and caring community), motivated public, private and financial actions to address climate change to a similar degree as believing climate change is important. Critically, relationships were similar for both convinced and unconvinced participants, showing that co-benefits can motivate action across ideological divides. These relationships were also independent of perceived climate change importance, and could not be explained by political ideology, age, or gender. Communicating co-benefits could motivate action on climate change where traditional approaches have stalled
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