1,959 research outputs found
Research Diary Visual Mapping : a reflective methodological tool for process and strategy-as-practice studies
Balogun, Huff and Johnson (2003) highlight the growing paradox for researchers who must focus on context and details while favouring general lines of research. These authors focus their reflection around the collection of qualitative data, particularly those of discussion groups, collaborative research and of research journal redaction techniques. We propose, in the context of collaborative research, a new utilisation of the personal diary, fuelled by our doctoral experiences in collaborative research. While the personal diary in its usual form increases the level of reflectivity on an intervening process, it is nevertheless difficult to exploit for the work of interpreting and legitimizing research. We therefore propose personal diary mapping. In addition to the advantages of personal diary mapping as a methodological tool for viewing the phenomenon, it allows a process to be described by highlighting specifics that are not obvious in reading a text. Moreover, the process of personal diary mapping provides a contribution to the epistemic work in a constructivist reference because it helps make the relationship between knowledge and empirical information explicit (Martinet 2007). After a summary bringing process studies closer to SaP and a review of the modalities of action research and their implications in terms of ethics and researcher responsibility, we present the origins, principles and benefits of visual mapping as regards the researcher's responsibility. In a second step, we illustrate the normative elements of this approach through a case study on strategic competence development based on personal diary mapping.Research Diary ; Visual Mapping ; methodological tool ; process ; strategy-as-practice
Utilizing osteocyte derived factors to enhance cell viability and osteogenic matrix deposition within IPN hydrogels
Many bone defects arising due to traumatic injury, disease, or surgery are unable to regenerate, requiring intervention. More than four million graft procedures are performed each year to treat these defects making bone the second most commonly transplanted tissue worldwide. However, these types of graft suffer from a limited supply, a second surgical site, donor site morbidity, and pain. Due to the unmet clinical need for new materials to promote skeletal repair, this study aimed to produce novel biomimetic materials to enhance stem/stromal cell osteogenesis and bone repair by recapitulating aspects of the biophysical and biochemical cues found within the bone microenvironment. Utilizing a collagen type I-alginate interpenetrating polymer network we fabricated a material which mirrors the mechanical and structural properties of unmineralized bone, consisting of a porous fibrous matrix with a young's modulus of 64 kPa, both of which have been shown to enhance mesenchymal stromal/stem cell (MSC) osteogenesis. Moreover, by combining this material with biochemical paracrine factors released by statically cultured and mechanically stimulated osteocytes, we further mirrored the biochemical environment of the bone niche, enhancing stromal/stem cell viability, differentiation, and matrix deposition. Therefore, this biomimetic material represents a novel approach to promote skeletal repair
The star cluster survivability after gas expulsion is independent of the impact of the Galactic tidal field
We study the impact of the tidal field on the survivability of star clusters
following instantaneous gas expulsion. Our model clusters are formed with a
centrally-peaked star-formation efficiency profile as a result of
star-formation taking place with a constant efficiency per free-fall time. We
define the impact of the tidal field as the ratio of the cluster half-mass
radius to its Jacobi radius immediately after gas expulsion, . We vary by varying either the Galactocentric distance,
or the size (hence volume density) of star clusters.
We propose a new method to measure the violent relaxation duration, in which
we compare the total mass-loss rate of star clusters with their stellar
evolutionary mass-loss rate. That way, we can robustly estimate the bound mass
fraction of our model clusters at the end of violent relaxation. The duration
of violent relaxation correlates linearly with the Jacobi radius, when
considering identical clusters at different Galactocentric distances. In
contrast, it is nearly constant for the solar neighbourhood clusters, slightly
decreasing with . The violent relaxation does not last longer than 50
Myr in our simulations.
Identical model clusters placed at different Galactocentric distances have
the same final bound fraction, despite experiencing different impacts of the
tidal field. The solar neighbourhood clusters with different densities
experience only limited variations of their final bound fraction.
In general, we conclude that the cluster survivability after instantaneous
gas expulsion, as measured by their bound mass fraction at the end of violent
relaxation, , is independent of the impact of the tidal field,
.Comment: accepted for publication in MNRAS, 8 pages, 5 figures,3 table
The Old Halo metallicity gradient: the trace of a self-enrichment process
Based on a model of globular cluster self-enrichment published in a previous
paper, we present an explanation for the metallicity gradient observed
throughout the galactic Old Halo. Our self-enrichment model is based on the
ability of globular cluster progenitor clouds to retain the ejecta of a first
generation of Type II Supernovae. The key point is that this ability depends on
the pressure exerted on the progenitor cloud by the surrounding protogalactic
medium and therefore on the location of the cloud in the protoGalaxy. Since
there is no significant (if any) metallicity gradient in the whole halo, we
also present a review in favour of a galactic halo partly build via accretions
and mergers of satellite systems. Some of them bear their own globular clusters
and therefore ``contaminate'' the system of globular clusters formed ``in
situ'', namely within the original potential well of the Galaxy. Therefore, the
comparison between our self-enrichment model and the observational data should
be limited to the genuine galactic globular clusters, the so-called Old Halo
group.Comment: 11 pages, 4 figures, accepted for publication in Astronomy and
Astrophysic
Impact phenomena as factors in the evolution of the Earth
It is estimated that 30 to 200 large impact basins could have been formed on the early Earth. These large impacts may have resulted in extensive volcanism and enhanced endogenic geologic activity over large areas. Initial modelling of the thermal and subsidence history of large terrestrial basins indicates that they created geologic and thermal anomalies which lasted for geologically significant times. The role of large-scale impact in the biological evolution of the Earth has been highlighted by the discovery of siderophile anomalies at the Cretaceous-Tertiary boundary and associated with North American microtektites. Although in neither case has an associated crater been identified, the observations are consistent with the deposition of projectile-contaminated high-speed ejecta from major impact events. Consideration of impact processes reveals a number of mechanisms by which large-scale impact may induce extinctions
The self-enrichment of galactic halo globular clusters : a clue to their formation ?
We present a model of globular cluster self-enrichment. In the protogalaxy,
cold and dense clouds embedded in the hot protogalactic medium are assumed to
be the progenitors of galactic halo globular clusters. The massive stars of a
first generation of metal-free stars, born in the central areas of the
proto-globular cluster clouds, explode as Type II supernovae. The associated
blast waves trigger the expansion of a supershell, sweeping all the material of
the cloud, and the heavy elements released by these massive stars enrich the
supershell. A second generation of stars is born in these compressed and
enriched layers of gas. These stars can recollapse and form a globular cluster.
This work aims at revising the most often encountered argument against
self-enrichment, namely the presumed ability of a small number of supernovae to
disrupt a proto-globular cluster cloud. We describe a model of the dynamics of
the supershell and of its progressive chemical enrichment. We show that the
minimal mass of the primordial cluster cloud required to avoid disruption by
several tens of Type II supernovae is compatible with the masses usually
assumed for proto-globular cluster clouds. Furthermore, the corresponding
self-enrichment level is in agreement with halo globular cluster metallicities.Comment: 12 pages, 7 figures. Accepted for publication in Astronomy and
Astrophysic
Cartographie du journal personnel : Un outil méthodologique réflectif pour la recherche-intervention
Nous proposons ici un outil méthodologique de condensation du matériau empirique à partir du journal personnel dans le cadre d'études longitudinales. En effet, le journal personnel permet d'accéder à une densité et une richesse d'information sur un phénomène, mais son utilisation n'est pas aisément mobilisable en dehors d'une méthode ethnographique. Par ailleurs la proposition d'outils de condensation des données facilitant l'étude des éléments empiriques est un axe nécessaire au développement de nos disciplines. La cartographie du journal personnel émerge de ces constats. Cette méthode de cartographie du journal personnel, inscrite dans la lignée du travail de Langley (1999), permet une meilleure visualisation des événements concomitants dans une étude longitudinale mais aussi une perception globale du phénomène étudié. Cet outil est intéressant à plusieurs titres. D'une manière générale il valorise la responsabilité sociale du chercheur dans la construction et le déroulement de sa recherche. Tout d'abord car son élaboration constitue ainsi une phase d'examen à part entière puisqu'elle nécessite de choisir le référentiel, de trier et d'organiser les événements structurants à la base de la création de la cartographie du journal personnel. Cette phase d'élaboration fait aussi apparaître les dynamiques à l'œuvre, sources d'une compréhension articulée du phénomène. Par ailleurs il peut être utilisé comme outil de visualisation central dans une méthodologie utilisant d'autres sources d'information. Cette contribution propose une illustration de la construction de l'outil par une succession d'étapes. Un exemple précis est donné par la présentation détaillée d'un cas d'étude de construction d'une capacité organisationnelle stratégique. Cette recherche intervention est menée dans une entreprise de biotechnologie ; elle étudie la mise en place de la capacité d'homologation internationaleMéthodologie ; Ethique ; Capacité organisationnelle ; Recherche ; intervention
Finding a reflexive voice : -- researching the problems of implementing new learning practices within a New Zealand manufacturing organisation : a 100pt thesis presented in partial fulfilment of the requirements for the degree of Master of Management in Human Resources Management at Massey University
This study explored the social forces mediating manager's participation in a new reflexive participative learning practice designed to improve profitability within a New Zealand manufacturing organisation. Despite a large theoretical and managerial body of literature on organisational learning there has been little empirical investigation of how people experience and engage their reflexivity towards challenging the status-quo to create high level learning and new knowledge. Power was identified as a potential moderator of the reflexive learning experience and the variable relations of power and learning were constructed from a review of literature and these relationships were explored and investigated within the case study. Two prevailing discourses were identified as powerful moderators of public reflexivity, the traditionalist discourse which constructed managers actions and conversations towards insularism and survivalist concerns and the productionist discourse in which institutionalised production practices encircled and mediated managers actions and what constituted legitimacy in conversations. This study used a critical action research method to place the reflexive experience of managers and the researcher at the centre of the study and provide data representative of the social discourses that constructed variable freedoms and constraints upon the reflexive voice
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