232 research outputs found
Réseau de bibliothÚques Renouvaud: typologies d'usagers, leurs comportements et leurs stratégies de recherches : analyse et recommandations
Depuis lâĂ©tĂ© 2016, le rĂ©seau Renouvaud a Ă©tĂ© mis en place pour gĂ©rer plus de 120 bibliothĂšques du canton de Vaud. Afin dâoffrir lâoutil le plus adaptĂ© possible aux usagers, il a Ă©tĂ© dĂ©cidĂ© de rĂ©aliser une enquĂȘte sur les comportements de recherches de ces derniers. AprĂšs une analyse du rĂ©seau, de ses fonctionnalitĂ©s et particularitĂ©s, un questionnaire et des entretiens ont Ă©tĂ© rĂ©alisĂ©s. Renouvaud se compose de deux institutions diffĂ©rentes, « Sciences et patrimoines » et « Ecoles et lecture publique », regroupant des types de bibliothĂšques diffĂ©rents et des ressources diffĂ©rentes. Pour « Sciences et patrimoines », des entretiens ont Ă©tĂ© menĂ©s auprĂšs dâenseignants, de chercheurs et dâĂ©tudiants. Pour « Ecoles et lecture publique », un questionnaire a Ă©tĂ© transmis Ă des usagers de lecture publique. Des personas ont Ă©tĂ© crĂ©Ă©s pour reprĂ©senter les quatre types dâusagers interrogĂ©s durant lâenquĂȘte : usager de lecture publique, enseignant, chercheur et Ă©tudiant. Chaque persona est le rĂ©sultat des enquĂȘtes menĂ©es durant le travail. Lâanalyse de lâenquĂȘte rĂ©alisĂ©e a permis de mieux apprĂ©hender les stratĂ©gies de recherche des usagers et leur utilisation de Renouvaud. Si les rĂ©sultats du questionnaire ont principalement fournis des donnĂ©es quantitatives sur Renouvaud, les entretiens ont permis dâobtenir des informations qualitatives aussi bien sur les recherches gĂ©nĂ©rales que sur les recherches dans Renouvaud. Nous remarquons ainsi que les usagers de lecture publique utilisent peu lâoutil de dĂ©couverte et prĂ©fĂšrent sâadresser aux bibliothĂ©caires. Nous notons Ă©galement des diffĂ©rences dâutilisation entre les enseignants, les chercheurs et les Ă©tudiants. Ces derniers ont des difficultĂ©s avec les articles en ligne et sont des adeptes de Google et Google Scholar, tandis que les chercheurs apprĂ©cient davantage les bases de donnĂ©es. Avec les commentaires des participants et les rĂ©sultats de lâenquĂȘte, plusieurs recommandations sont proposĂ©es pour la coordination Renouvaud. ClassĂ©es par ordre dâimportance, elles offrent des pistes de rĂ©flexion sur les amĂ©liorations possibles pour lâoutil de dĂ©couverte et le rĂ©seau Renouvaud en gĂ©nĂ©ral. Enfin, une discussion sur le travail effectuĂ© clĂŽture le document pour Ă©valuer les difficultĂ©s et proposer une continuitĂ© Ă ce projet
A novel bioinformatics pipeline to discover genes related to arbuscular mycorrhizal symbiosis based on their evolutionary conservation pattern among higher plants
Genes involved in arbuscular mycorrhizal (AM) symbiosis have been identified primarily by mutant screens, followed by identification of the mutated genes (forward genetics). In addition, a number of AM-related genes has been identified by their AM-related expression patterns, and their function has subsequently been elucidated by knock-down or knock-out approaches (reverse genetics). However, genes that are members of functionally redundant gene families, or genes that have a vital function and therefore result in lethal mutant phenotypes, are difficult to identify. If such genes are constitutively expressed and therefore escape differential expression analyses, they remain elusive. The goal of this study was to systematically search for AM-related genes with a bioinformatics strategy that is insensitive to these problems. The central element of our approach is based on the fact that many AM-related genes are conserved only among AM-competent species.Results: Our approach involves genome-wide comparisons at the proteome level of AM-competent host species with non-mycorrhizal species. Using a clustering method we first established orthologous/paralogous relationships and subsequently identified protein clusters that contain members only of the AM-competent species. Proteins of these clusters were then analyzed in an extended set of 16 plant species and ranked based on their relatedness among AM-competent monocot and dicot species, relative to non-mycorrhizal species. In addition, we combined the information on the protein-coding sequence with gene expression data and with promoter analysis. As a result we present a list of yet uncharacterized proteins that show a strongly AM-related pattern of sequence conservation, indicating that the respective genes may have been under selection for a function in AM. Among the top candidates are three genes that encode a small family of similar receptor-like kinases that are related to the S-locus receptor kinases involved in sporophytic self-incompatibility.Conclusions: We present a new systematic strategy of gene discovery based on conservation of the protein-coding sequence that complements classical forward and reverse genetics. This strategy can be applied to diverse other biological phenomena if species with established genome sequences fall into distinguished groups that differ in a defined functional trait of interest
Assessing the visual aspect of rotating virtual rose bushes by a labeled sorting task
Aesthetics is one of the major parameters for consumers when buying a rose bush. Therefore, managing this quality is important for agronomists. Tools are needed to assess visual characteristics and to find links with architectural plant parameters. Sensory analyses were developed using real plants and photographs as stimuli. With technology and modeling improvements, using virtual plants could presents numerous advantages. This study demonstrated the feasibility of using rotating virtual rose bush videos as stimuli for a labeled sorting task. The virtual rose bush reflected a natural within-crop variability of one cultivar based on bud breaks location and axes length. Two panels of subjects closely linked to the horticulture sector sorted and described 40 rotating virtual rose bush videos. Non-metric Multidimensional Scaling (MDS) results for both panels were similar and allowed us to highlight five groups of virtual rose bushes with their specific sensory characteristics and their own most representative products using a combination of the paragons and the most typical products. This approach revealed that subjects detected high visual differences between products, and that by using rotation, they were able to integrate 3D properties about variations around plant facets. Finally, a labeled sorting task is a powerful method for preliminary exploration of the visual aspect of virtual plants
Identification of a GTP-bound Rho specific scFv molecular sensor by phage display selection
<p>Abstract</p> <p>Background</p> <p>The Rho GTPases A, B and C proteins, members of the Rho family whose activity is regulated by GDP/GTP cycling, function in many cellular pathways controlling proliferation and have recently been implicated in tumorigenesis. Although overexpression of Rho GTPases has been correlated with tumorigenesis, only their GTP-bound forms are able to activate the signalling pathways implicated in tumorigenesis. Thus, the focus of much recent research has been to identify biological tools capable of quantifying the level of cellular GTP-bound Rho, or determining the subcellular location of activation. However useful, these tools used to study the mechanism of Rho activation still have limitations. The aim of the present work was to employ phage display to identify a conformationally-specific single chain fragment variable (scFv) that recognizes the active, GTP-bound, form of Rho GTPases and is able to discriminate it from the inactive, GDP-bound, Rho in endogenous settings.</p> <p>Results</p> <p>After five rounds of phage selection using a constitutively activated mutant of RhoB (RhoBQ63L), three scFvs (A8, C1 and D11) were selected for subsequent analysis. Further biochemical characterization was pursued for the single clone, C1, exhibiting an scFv structure. C1 was selective for the GTP-bound form of RhoA, RhoB, as well as RhoC, and failed to recognize GTP-loaded Rac1 or Cdc42, two other members of the Rho family. To enhance its production, soluble C1 was expressed in fusion with the N-terminal domain of phage protein pIII (scFv C1-N1N2), it appeared specifically associated with GTP-loaded recombinant RhoA and RhoB via immunoprecipitation, and endogenous activated Rho in HeLa cells as determined by immunofluorescence.</p> <p>Conclusion</p> <p>We identified an antibody, C1-N1N2, specific for the GTP-bound form of RhoB from a phage library, and confirmed its specificity towards GTP-bound RhoA and RhoC, as well as RhoB. The success of C1-N1N2 in discriminating activated Rho in immunofluorescence studies implies that this new tool, in collaboration with currently used RhoA and B antibodies, has the potential to analyze Rho activation in cell function and tumor development.</p
Detection of label-free cancer biomarkers using nickel nanoislands and quartz crystal microbalance
We present a technique for the label-free detection and recognition of cancer biomarkers using metal nanoislands intended to be integrated in a novel type of nanobiosensor. His-tagged (scFv)-F7N1N2 is the antibody fragment which is directly immobilized, by coordinative bonds, onto ~5 nm nickel islands, then deposited on the surface of a quartz crystal of a quartz crystal microbalance (QCM) to validate the technique. Biomarker GTPase RhoA was investigated because it has been found to be overexpressed in various tumors and because we have recently isolated and characterized a new conformational scFv which selectively recognizes the active form of RhoA. We implemented a surface chemistry involving an antibiofouling coating of polyethylene glycol silane (PEG-silane) (<2 nm thick) and Ni nanoislands to reach a label-free detection of the active antigen conformation of RhoA, at various concentrations. The methodology proposed here proves the viability of the concept by using Ni nanoislands as an anchoring surface layer enabling the detection of a specific conformation of a protein, identified as a potential cancer biomarker. Hence, this novel methodology can be transferred to a nanobiosensor to detect, at lower time consumption and with high sensitivity, specific biomolecules
âInto and out ofâ the QinghaiâTibet plateau and the Himalayas: centers of origin and diversification across five clades of Eurasian montane and alpine passerine birds
Encompassing some of the major hotspots of biodiversity on Earth, large mountain systems have long held the attention of evolutionary biologists. The region of the QinghaiâTibet Plateau (QTP) is considered a biogeographic source for multiple colonization events into adjacent areas including the northern Palearctic. The faunal exchange between the QTP and adjacent regions could thus represent a oneâway street (âout ofâ the QTP). However, immigration into the QTP region has so far received only little attention, despite its potential to shape faunal and floral communities of the QTP. In this study, we investigated centers of origin and dispersal routes between the QTP, its forested margins and adjacent regions for five clades of alpine and montane birds of the passerine superfamily Passeroidea. We performed an ancestral area reconstruction using BioGeoBEARS and inferred a timeâcalibrated backbone phylogeny for 279 taxa of Passeroidea. The oldest endemic species of the QTP was dated to the early Miocene (ca. 20 Ma). Several additional QTP endemics evolved in the mid to late Miocene (12â7 Ma). The inferred centers of origin and diversification for some of our target clades matched the âout of Tibet hypothesisâ or the âout of Himalayas hypothesisâ for others they matched the âinto Tibet hypothesis.â Three radiations included multiple independent Pleistocene colonization events to regions as distant as the Western Palearctic and the Nearctic. We conclude that faunal exchange between the QTP and adjacent regions was bidirectional through time, and the QTP region has thus harbored both centers of diversification and centers of immigration
The Leadership Processes of Pacific Public Servants in Aotearoa, New Zealand
This dissertation presents research focused on leadership processes among Pacific public servants at multiple levels in the New Zealand Public Service. The current study was guided by this research question: What are the leadership processes currently employed by Pacific public servants in the New Zealand Public Service? This study also explored participants' views on the effect of Pacific cultural backgrounds and organisational contexts on their current experience of leadership processes. The exploration of the topic was developed within a post-positivist research paradigm, using phenomenological methodology to examine the leadership processes of Pacific public servants. It employs qualitative case studies of two New Zealand Public Service organisations in the Wellington region. I employed two data collection tools in these case studies. The first was the use of in-depth interviews, and the second was an analysis of relevant organisational documents. A total of sixteen Pacific public servants participated in my study, eight from each case organisation. The findings indicated that the Pacific participants understood leadership as a social process of collective influence within a context. Participants perceived participating, networking and relationship building, learning about leadership from cultural contexts, and practising the Pacific value of va as important leadership processes for their performance in the organisations in which they were working. This study also found that the organisations' key roles and leadership values, which are embedded in Pacific cultures, shaped participants' experiences of the leadership processes. The findings also highlight some factors that contribute to and constrain the Pacific public servants' leadership processes. This emphasises the need for diverse policies to encompass leadership development. This study also highlights the need for leadership support for Pacific public servants at all levels in their New Zealand organisations. Practical and future research recommendations gained from the findings are discussed. The study contributes to the field of leadership research on Pacific public servants in New Zealand, and provides a different perspective on leadership processes in general leadership theory
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