26 resultados para post-structural theory

em BORIS: Bern Open Repository and Information System - Berna - Suiça


Relevância:

80.00% 80.00%

Publicador:

Resumo:

There has been increasing interest in the discursive aspects of strategy over the last two decades. In this editorial we review the existing literature, focusing on six major bodies of discursive scholarship: post-structural, critical discourse analysis, narrative, rhetoric, conversation analysis and metaphor. Our review reveals the significant contributions of research on strategy and discourse, but also the potential to advance research in this area by bringing together research on discursive practices and research on other practices we know to be important in strategy work. We explore the potential of discursive scholarship in integrating between significant theoretical domains (sensemaking, power and sociomateriality), and realms of analysis (institutional, organizational and the episodic), relevant to strategy scholarship. This allows us to place the papers published in the special issue Strategy as Discourse: Its Significance, Challenges and Future Directions among the body of knowledge accumulated thus far, and to suggest a way forward for future scholarship.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

This investigation attempts to answer the question why more and more parents have chosen the Gymnasium for their children's secondary school education in post‐war West Germany. Based on the theory of subjective expected utility, the crucial mechanisms of parental educational decisions have been emphasized. From this perspective it is assumed that increasing educational motivation coupled with changes in the subjective evaluation of the cost–benefit of education were important conditions for an increasing participation in upper secondary schools. These were, however, in turn, the result of educational expansion. The empirical analyses for three time‐periods in the 1960s, 1970s, and 1980s confirm these assumptions to a large degree. Additionally, empirical evidence was found to suggest that in addition to the intentions of parents and the educational career of their children, structural moments of educational expansion and their own inertia played an important role in the pupils' transition from one educational level to the next. Finally, evidence was found that persistent class‐specific educational inequality stems from a constant balance in the relative cost–benefit advantages between social classes as well as from an increasing difference of primary origin effect between social classes in the realization of their educational choice.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Human auditory nerve afferents consist of two separate systems; one is represented by the large type I cells innervating the inner hair cells and the other one by the small type II cells innervating the outer hair cells. Type I spiral ganglion neurons (SGNs) constitute 96% of the afferent nerve population and, in contrast to other mammals, their soma and pre- and post-somatic segments are unmyelinated. Type II nerve soma and fibers are unmyelinated. Histopathology and clinical experience imply that human SGNs can persist electrically excitable without dendrites, thus lacking connection to the organ of Corti. The biological background to this phenomenon remains elusive. We analyzed the pre- and post-somatic segments of the type I human SGNs using immunohistochemistry and transmission electron microscopy (TEM) in normal and pathological conditions. These segments were found surrounded by non-myelinated Schwann cells (NMSCs) showing strong intracellular expression of laminin-β2/collagen IV. These cells also bordered the perikaryal entry zone and disclosed surface rugosities outlined by a folded basement membrane (BM) expressing laminin-β2 and collagen IV. It is presumed that human large SGNs are demarcated by three cell categories: (a) myelinated Schwann cells, (b) NMSCs and (c) satellite glial cells (SGCs). Their BMs express laminin-β2/collagen IV and reaches the BM of the sensory epithelium at the habenula perforata. We speculate that the NMSCs protect SGNs from further degeneration following dendrite loss. It may give further explanation why SGNs can persist as electrically excitable monopolar cells even after long-time deafness, a blessing for the deaf treated with cochlear implantation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The synthesis of a novel bicyclo-thymidine nucleoside bearing an ester functionality at C(6') (bc(alpha-alk)-nucleosides) is reported. This nucleoside was incorporated into oligodeoxynucleotides via solid phase phosphoramidite chemistry, and the ester moiety was post-synthetically converted to an amide or a carboxy group, or was left unchanged. Thermal melting data (T-m) with complementary DNA and RNA were collected and compared to natural DNA and to bc- and bc(ox)-DNA. It was found that single incorporations of bc(alpha-alk)-nucleosides in DNA duplexes were destabilizing by 0.5 to 2.5 degrees C/mod, whereas two consecutive bc(alpha-alk)-residues were less destabilizing, and in some cases even stabilizing by 0.5 degrees C/mod. In duplexes with complementary RNA, isolated bc(alpha-alk)-residues destabilized the duplex by -1.0 to -4.0 degrees C/mod, depending on the chemical nature of the substituent, whereas two consecutive modifications were only destabilizing by 0.3-1.0 degrees C/mod. The pairing selectivity was similar to that of unmodified or bc-DNA.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dynamic core-shell nanoparticles have received increasing attention in recent years. This paper presents a detailed study of Au-Hg nanoalloys, whose composing elements show a large difference in cohesive energy. A simple method to prepare Au@Hg particles with precise control over the composition up to 15 atom% mercury is introduced, based on reacting a citrate stabilized gold sol with elemental mercury. Transmission electron microscopy shows an increase of particle size with increasing mercury content and, together with X-ray powder diffraction, points towards the presence of a core-shell structure with a gold core surrounded by an Au-Hg solid solution layer. The amalgamation process is described by pseudo-zero-order reaction kinetics, which indicates slow dissolution of mercury in water as the rate determining step, followed by fast scavenging by nanoparticles in solution. Once adsorbed at the surface, slow diffusion of Hg into the particle lattice occurs, to a depth of ca. 3 nm, independent of Hg concentration. Discrete dipole approximation calculations relate the UV-vis spectra to the microscopic details of the nanoalloy structure. Segregation energies and metal distribution in the nanoalloys were modeled by density functional theory calculations. The results indicate slow metal interdiffusion at the nanoscale, which has important implications for synthetic methods aimed at core-shell particles.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Biological systems have acquired effective adaptive strategies to cope with physiological challenges and to maximize biochemical processes under imposed constraints. Striated muscle tissue demonstrates a remarkable malleability and can adjust its metabolic and contractile makeup in response to alterations in functional demands. Activity-dependent muscle plasticity therefore represents a unique model to investigate the regulatory machinery underlying phenotypic adaptations in a fully differentiated tissue. Adjustments in form and function of mammalian muscle have so far been characterized at a descriptive level, and several major themes have evolved. These imply that mechanical, metabolic and neuronal perturbations in recruited muscle groups relay to the specific processes being activated by the complex physiological stimulus of exercise. The important relationship between the phenotypic stimuli and consequent muscular modifications is reflected by coordinated differences at the transcript level that match structural and functional adjustments in the new training steady state. Permanent alterations of gene expression thus represent a major strategy for the integration of phenotypic stimuli into remodeling of muscle makeup. A unifying theory on the molecular mechanism that connects the single exercise stimulus to the multi-faceted adjustments made after the repeated impact of the muscular stress remains elusive. Recently, master switches have been recognized that sense and transduce the individual physical and chemical perturbations induced by physiological challenges via signaling cascades to downstream gene expression events. Molecular observations on signaling systems also extend the long-known evidence for desensitization of the muscle response to endurance exercise after the repeated impact of the stimulus that occurs with training. Integrative approaches involving the manipulation of single factors and the systematic monitoring of downstream effects at multiple levels would appear to be the ultimate method for pinpointing the mechanism of muscle remodeling. The identification of the basic relationships underlying the malleability of muscle tissue is likely to be of relevance for our understanding of compensatory processes in other tissues, species and organisms.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This book will serve as a foundation for a variety of useful applications of graph theory to computer vision, pattern recognition, and related areas. It covers a representative set of novel graph-theoretic methods for complex computer vision and pattern recognition tasks. The first part of the book presents the application of graph theory to low-level processing of digital images such as a new method for partitioning a given image into a hierarchy of homogeneous areas using graph pyramids, or a study of the relationship between graph theory and digital topology. Part II presents graph-theoretic learning algorithms for high-level computer vision and pattern recognition applications, including a survey of graph based methodologies for pattern recognition and computer vision, a presentation of a series of computationally efficient algorithms for testing graph isomorphism and related graph matching tasks in pattern recognition and a new graph distance measure to be used for solving graph matching problems. Finally, Part III provides detailed descriptions of several applications of graph-based methods to real-world pattern recognition tasks. It includes a critical review of the main graph-based and structural methods for fingerprint classification, a new method to visualize time series of graphs, and potential applications in computer network monitoring and abnormal event detection.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Die vorliegende Untersuchung ist ein Beitrag, die Frage zu klären, warum in der westdeutschen Nachkriegszeit immer mehr Schulpflichtige nach Abschluss der Grundschule das Gymnasium besuchen. Ausgehend von einem entscheidungstheoretischen Modell der subjektiven Werterwartung werden Mechanismen der elterlichen Bildungsentscheidung aufgezeigt. Dabei wird davon ausgegangen, dass sowohl zunehmende Bildungsmotivationen als auch Veränderungen in der subjektiven Bewertung von Kosten und Nutzen für eine höhere Bildung wichtige Voraussetzungen für die zunehmende Bildungsbeteiligung, aber auch Folgen der Bildungsexpansion waren. Die empirischen Analysen für drei Zeitpunkte in den 60er, 70er und 80er Jahren bestätigen diese Annahmen weitgehend. Ebenso wurde empirisch belegt, welch wichtige Rolle neben den Bildungsintentionen von Eltern und dem vorhergehenden Bildungsverlauf ihrer Kinder auch strukturelle Momente der Bildungsexpansion und ihre Eigendynamik beim tatsächlichen Bildungsübergang spielen. Schließlich gibt es Hinweise dafür, dass die Persistenz klassenspezifischer Bildungsungleichheiten auf einer konstanten Balance von Nutzen und Kosten zwischen den sozialen Klassen basiert.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In 1999, all student teachers at secondary I level at the University of Bern who had to undertake an internship were asked to participate in a study on learning processes during practicum: 150 students and their mentors in three types of practicum participated—introductory practicum (after the first half‐year of studies), intermediate practicum (after two years of studies) and final practicum (after three years of studies). At the end of the practicum, student teachers and mentors completed questionnaires on preparing, teaching and post‐processing lessons. All student teachers, additionally, rated their professional skills and aspects of personality (attitudes towards pupils, self‐assuredness and well‐being) before and after the practicum. Forty‐six student teachers wrote daily semi‐structured diaries about essential learning situations during their practicum. Results indicate that in each practicum students improved significantly in preparing, conducting and post‐processing lessons. The mentors rated these changes as being greater than did the student teachers. From the perspective of the student teachers their general teaching skills also improved, and their attitudes toward pupils became more open. Furthermore, during practicum their self‐esteem and subjective well‐being increased. Diary data confirmed that there are no differences between different levels of practicum in terms of learning outcomes, but give some first insight into different ways of learning during internship.