Stratifications with respect to actions of real reductive groups

We study the action of a real reductive group G on a real submanifold X of a K"ahler manifold Z. We suppose that the action of G extends holomorphically to an action of a complex reductive group and is Hamiltonian with respect to a compatible maximal compact subgroup of the complex reductive group. There is a corresponding gradient map obtained from a Cartan decomposition of G. We obtain a Morse like function on X. Associated to its critical points are various sets of semistable points which we study in great detail. In particular, we have G-stable submanifolds of X which are called pre-strata. In case that the gradient map is proper, the pre-strata form a decomposition of X and in case that X is compact they are the strata of a Morse type stratification of X. Our results are generalizations of results of Kirwan obtained in the case that X=Z is compact and the group itself is complex reductive.Comment: 29 pages, minor errors corrected, referee suggestions implemente

Challenges and Dilemmas in Open Innovation: Ambidexterity as Management Approach

What are the relevant management challenges for open innovation, and how do companies tackle these challenges? This study adds to the research of open innovation management by investigating different management dimensions and their inherent dilemmas. By applying the concept of organizational ambidexterity as an approach to pursue apparently conflicting objectives, we extend previous research in two key aspects: First, in contrast to most studies we do not focus on a single management dimension but consider a wider set of dimensions which we found evidence to be relevant for open innovation. Second, unlike previous studies which consider ambidexterity for managing open innovation, we do not limit our discussion to ambidexterity as a whole but consider different modes of ambidexterity. Our findings support this approach: We find structural ambidexterity for the degree of innovation, organizational configuration, intellectual property management and motivation. We also find temporal and contextual ambidexterity in two additional dimensions

Making the Transition to Virtual Methods in the Literacy Classroom: Reframing Teacher Education Practices

In response to the COVID 19 pandemic universities and colleges abruptly closed and teacher educators had little time to move instruction from face-to-face classrooms to digital learning environments. This sudden shift created a myriad of obstacles as instructors worked to retain pedagogically sound and effective instruction digitally—while also preparing novice teachers to teach online themselves. Adding another layer of complexity was prospective teachers’ lack of knowledge and hesitation regarding technology tools, as well as how to meaningfully integrate the tools into their teaching. Facing these challenges, we as literacy teacher educators drew upon effective methods of teacher education, literacy practices and digital literacy to rethink the way we design lessons and assignments for our literacy methods courses. The framework we created for restructuring the integration of technology into courses can be duplicated across disciplines and guide instructors to reconceptualize their use of tech tools to re-envision face-to-face and digital instruction to expand learning outcomes

Spherical gradient manifolds

We study the action of a real-reductive group G=K\exp(\lie{p}) on real-analytic submanifold $X$ of a K\"ahler manifold $Z$. We suppose that the action of $G$ extends holomorphically to an action of the complexified group G^\mbb{C} such that the action of a maximal Hamiltonian subgroup is Hamiltonian. The moment map $\mu$ induces a gradient map \mu_\lie{p}\colon X\to\lie{p}. We show that \mu_\lie{p} almost separates the $K$--orbits if and only if a minimal parabolic subgroup of $G$ has an open orbit. This generalizes Brion's characterization of spherical K\"ahler manifolds with moment maps.Comment: 18 page

Key Differentiators of Open Innovation Platforms – A Market-oriented Perspective

Within the open innovation debate, significant attention has beenpaid to the fact that customers can be a useful source for bringingnew ideas and concepts into a company. In this context, onlineplatforms have become a widely used instrument to facilitateinteraction between companies and customers. While priorliterature discusses various aspects of open innovation platforms,a market-oriented analysis covering all types of platforms for ideacreation and concept development seems to be still missing. Byevaluating a total of 44 different innovation platforms, we identifythe degree of interrelation between five major platform attributesand develop two key differentiating dimensions: The platformoperator (company vs. third party) and the platform purpose (findsolutions vs. understand customers). The resulting classificationmatrix highlights a newly emerging category of online openinnovation platforms, opening the field for deeper investigation infuture research

L’identification et l’impact de différents types de réseaux sociaux dans les trajectoires de vie de personnes assistées sociales

Ce mémoire traite du rôle des réseaux sociaux dans les trajectoires de vie des personnes qui vivent de l’aide sociale au Québec. La discrimination et la stigmatisation sont des processus émanant de rapports sociaux dans lesquels peuvent être inscrites ces personnes du fait de leurs conditions de vie précaires. L’analyse des réseaux sociaux pourrait nous permettre de découvrir certaines dynamiques, propres à ces rapports sociaux, en portant sur leur caractère qualitatif et temporel. Nous avons eu recours aux récits de vie afin d’identifier certains réseaux sociaux émergeant du discours et d’élaborer un modèle d’analyse qualitative des réseaux sociaux dans une perspective de trajectoire de vie. Cette étape a permis de percevoir l’existence d’un lien entre certains événements importants du récit et les transformations des relations. Nous avons également relevé dans le discours des indicateurs de la qualité des contacts selon leur contribution « positive », « négative » ou « neutre » dans la trajectoire. La comparaison des trajectoires des personnes sélectionnées a permis d’identifier des morphologies de réseaux similaires et de dresser une typologie. Les types ont pu être identifiés en fonction des trois catégories dominantes de contacts évoquées par les répondants : la famille, les connaissances, et les organismes. La mention de l’aide sociale, de contacts en psychiatrie ou même le passage sous silence par le répondant d’une de ces catégories a permis de nuancer la typologie et de recenser onze types de réseaux. Afin d’évaluer l’intérêt de ce modèle d’analyse, nous avons tenté une opérationnalisation exploratoire de la typologie.This thesis examines the role of social networks in life trajectories of individuals living on social security benefits in Quebec. The precarious living conditions of these individuals can be situated in social relations from which discrimination and stigmatization arise. Analysis of social networks can allow us to discover certain dynamics, particularly with regard to their qualitative and temporal character. Life story narratives were used in order to identify certain social networks in discourse and in elaborating a qualitative analysis model of social networks within a life trajectory perspective. This step allowed to identify a link between certain important narrative events and transformation of relations. Also revealed in discourse were quality indicators of contacts in relation to either a “positive”, “negative” or “neutral” contribution in the trajectory. The comparison of trajectories of the individuals selected allowed to identify similar network morphologies and to produce a typology. The different categories are identified in function of three dominant categories of contacts evoked by participants: family, knowledge and organisms. The mention of social security, psychiatric contact or even the respondent’s lapse into silence concerning one of the categories allowed to nuance the typology and to identify eleven types of networks. In order to assess the pertinence of this analytical model, an exploratory demonstration of the typology was effectuated

Multi-taxa neo-taphonomic analysis of bone remains from barn owl pellets and cross-validation of observations: a case study from Dominica (Lesser Antilles)

Paleo- and neo-taphonomic analyses of bone assemblages rarely consider all the occurring taxa in a single study and works concerning birds of prey as accumulators of microvertebrate bone remains mostly focus on small mammals such as rodents and soricomorphs. However, raptors often hunt and consume a large range of taxa, including vertebrates such as small mammals, fishes, amphibians, squamates and birds. Bone remains of all these taxonomic groups are numerous in many paleontological and archaeological records, especially in cave deposits. To better characterize the predators at the origin of fossil and sub-fossil microvertebrate accumulations and the taphonomic history of the deposit, it is thus mandatory to conduct global and multi-taxa taphonomic approaches. The aim of this study is to provide an example of such a global approach through the investigation of a modern bone assemblage from a sample of pellets produced by the Lesser Antillean Barn Owl (Tyto insularis) in the island of Dominica. We propose a new methodology that allows us to compare different taxa (rodents, bats, squamates and birds) and to experiment with a cross-validation process using two observers for each taxonomic group to test the reliability of the taphonomic observations.1. Introduction 2. Materials and Methods 2.1. Owl Pellets Sampling 2.2. Prey Identification 2.3. Taphonomic Analysis 2.3.1. Anatomical Representation 2.3.2. Fragmentation 2.3.3. Surface Modifications 2.3.4. Size/Weight Classes of Preys 2.4. Cross-Validation of Observations 3. Results 3.1. Faunal Spectrum 3.2. Anatomical Representation 3.3. Fragmentation 3.4. Modifications of Bone Surface 4. Discussion 4.1. Diet of Tyto Insularis in Dominica 4.2. Taphonomic Impact of Tyto Insularis on Small Vertebrate Bone Assemblage 4.2.1. Remarks on the Size/Weight Classes of Preys 4.2.2. Anatomical Representation 4.2.3. Fragmentation 4.2.4. Digestion 4.3. Degree of Inter-Observer Differences and Potential Outcomes 4.4. Towards an “Inter-Taxa Calibration” 5. Conclusion

The use of paleoclimatic simulations to refine the environmental and chronological context of archaeological/paleontological sites

To reconstruct the paleoenvironmental and chronological context of archaeological/paleontological sites is a key step to understand the evolutionary history of past organisms. Commonly used method to infer paleoenvironments rely on varied proxies such as faunal assemblages and isotopes. However, those proxies often show some inconsistencies. Regarding estimated ages of stratigraphic layers, they can vary depending on the dating method used. In this paper, we tested the potential of paleoclimate simulations to address this issue and contribute to the description of the environmental and chronological context of archaeological/paleontological sites. We produced a set of paleoclimate simulations corresponding to the stratigraphy of a Late-Pleistocene Holocene site, El Harhoura 2 (Morocco), and compared the climatic sequence described by these simulations to environmental inferences made from isotopes and faunal assemblages. Our results showed that in the studied site combined US-ESR ages were much more congruent with paleoenvironmental inferences than OSL ages. In addition, climatic variations were found to be more consistent with isotopic studies than faunal assemblages, allowing us to discuss unresolved discrepancies to date. This study illustrates the strong potential of our approach to refine the paleoenvironmental and chronological context of archaeological and paleontological sites.1 Introduction 2 Material and methods 2.1 El Harhoura 2 cave 2.2 Paleoclimate simulations 2.2.1 Pre-existing ensemble of simulations 2.2.2 Model 2.2.3 Sea-surface boundary conditions 2.3 Climate variations through EH2 sequence 3 Results 3.1 Paleoclimate simulations 3.2 Climate variations through EH2 sequence 4 Discussion 5 Conclusio