400 research outputs found
The uses of Giddens' structuration theory
'Giddens hat sich fĂŒr die Verwendbarkeit der Strukturierungstheorie eingesetzt. Dabei stellte er die Strukturierungstheorie als einen Beitrag zur postempirischen Rekonstruktion der von Theorie und ihre Anwendung in den Sozialwissenschaften dar und, in logischer Folge, als eine Rechtfertigung einer Konzeption von empirischer Forschung, die sich von jenen in Ă€lteren traditionellen Theoriebildungen favorisierten unterscheidet. Giddens hat es dabei jedoch unterlassen, die Anwendung der Strukturierungstheorie an eigenen empirischen Untersuchungen aufzuzeigen oder stichhaltige Analysen innerhalb besonderer Forschungsgebiete explizit auf diese aufzubauen. Es ist allerdings nicht nötig, darauf zu warten, daĂ Giddens selbst seine Theorie an Beispielen veranschaulicht. Die Strukturierungstheorie hat es nĂ€mlich möglich gemacht, daĂ sozialwissenschaftliche Kollegen und Kolleginnen grundlegende disziplinĂ€re MĂ€ngel und Spezialgebiete, die im Augenblick zu beobachten sind, benennen können. Dabei hat sie fĂŒr eine Vielzahl von empirischen Forschungsprojekten bereits zur GĂ€nze oder teilweise den theoretischen Rahmen und das konzeptionelle Vokabular geschaffen. Der vorliegende Beitrag bietet eine Typologie der Anwendung mit Beispielen aus der Buchhaltung, der ArchĂ€ologie, Betriebswirtschaft und Managementwissenschaft, Humangeographie, Informatik, Organisationsstudien, der Politikwissenschaft, Religionswissenschaft und Soziologie. Die vorgenommene Typologie richtet sich nach den folgenden Untergliederungen: Rekonstituierung einer Disziplin, Rekonstituierung eines Spezialgebiets, Rekonstituierung eines interdisziplinĂ€ren Feldes, Neufassung vorangegangener Literatur und Forschung, Erleichterung empirischer Forschung und Neukonzipierung der Moderne. Es wird argumentiert, daĂ die auĂergewöhnliche Inanspruchnahme von Giddens damit verbunden ist, daĂ er eine benutzerInnenfreundliche 'Zwischentheorie' zur VerfĂŒgung stellt.' (Autorenreferat)'Anthony Giddens has made claims for the utility of structuration theory. These claims present structuration theory as a contributant to the post-empiricist reconstruction of theory and application in social science, and, consequently, as a justification for a different conception of empirical research from that favoured in the old theory-building tradition. What Giddens has not done is exemplify its use in empirical inquiries of his own or employ it explicitly in analyses of particular substantive areas. There is, however, no need to wait for Giddens himself to show us how to use his theory. Structuration theory has enabled colleagues across the social sciences to address what they perceive to be fundamental deficiencies in their disciplines and specialties as presently constituted, and it has provided all or part of the theoretical framework and conceptual vocabulary for an already large number of empirical projects. This article offers a typology of uses with examples from accountancy, archaeology, business and management studies, human geography, informatics, organisation studies, political science, religious studies and sociology. The subheadings are as follows: reconstituting a discipline, reconstituting a specialty, reconstituting an interdisciplinary field, reworking literature and past research, facilitating empirical research and reconsidering modernity. It is argued that the extraordinary take-up of Giddens is connected to his provision of user-friendly 'intermediate theory'.' (author's abstract)
Using relative sea-level data to constrain the deglacial and Holocene history of southern Greenland
This paper presents new Holocene relative sea-level (RSL) data collected from isolation basins close to the town of Paamiut in south west Greenland. The data shows a rapid fall from a marine limit of c. 52 m asl at c. 10.9 cal. ka BP to close to present by c. 9.5 cal. ka BP, at rates of up to c. 32 mm/yr, falling below present for the majority of the Holocene before rising to present in the last 2000 years. The elevation of the RSL lowstand is not well constrained, but was at least below â3 m. This pattern of rapid RSL fall during the early Holocene matches the pattern seen at other southern Greenland locations suggesting rapid, largely simultaneous ice retreat from the area surrounding the Qassimiut Lobe at the start of the Holocene, occurring c. 2000 years after the initial deglaciation of the extreme southern tip of Greenland. The RSL histories from this and other southern Greenland locations are distinct to those recorded further north along the west coast, and are in broad agreement with a pattern of vertical land motion and RSL predicted by the Huy2 model (Simpson et al., 2009), which predicts an 80 m drop in the contribution of vertical land motion to RSL at 10 cal. ka BP between Sisimiut and Paamiut on the west coast. Despite this broad-scale spatial agreement between the RSL data and the Huy2 model, it fails to satisfactorily predict the Holocene RSL histories at Paamiut and other southern Greenland locations. Sensitivity tests indicate that the data-model misfits are most likely due to an over-estimate of the forcing during the Holocene Thermal Maximum (or the response to this forcing) in southern Greenland and error in the North American ice sheets component of the background deglaciation model. Our new data suggests that much of the southern part of the ice sheet acted differently to the area further north. However RSL changes at Paamiut are also largely impacted by regional and larger-scale processes including a bulls-eye of uplift centred on the west, the impact of the Holocene Thermal Maximum and the influence of the collapse of the North American ice sheets
Spin and energy transfer in nanocrystals without transport of charge
We describe a mechanism of spin transfer between individual quantum dots that
does not require tunneling. Incident circularly-polarized photons create
inter-band excitons with non-zero electron spin in the first quantum dot. When
the quantum-dot pair is properly designed, this excitation can be transferred
to the neighboring dot via the Coulomb interaction with either {\it
conservation} or {\it flipping} of the electron spin. The second dot can
radiate circularly-polarized photons at lower energy. Selection rules for spin
transfer are determined by the resonant conditions and by the strong spin-orbit
interaction in the valence band of nanocrystals. Coulomb-induced energy and
spin transfer in pairs and chains of dots can become very efficient under
resonant conditions. The electron can preserve its spin orientation even in
randomly-oriented nanocrystals.Comment: 13 pages, 3 figure
Spin interactions and switching in vertically tunnel-coupled quantum dots
We determine the spin exchange coupling J between two electrons located in
two vertically tunnel-coupled quantum dots, and its variation when magnetic (B)
and electric (E) fields (both in-plane and perpendicular) are applied. We
predict a strong decrease of J as the in-plane B field is increased, mainly due
to orbital compression. Combined with the Zeeman splitting, this leads to a
singlet-triplet crossing, which can be observed as a pronounced jump in the
magnetization at in-plane fields of a few Tesla, and perpendicular fields of
the order of 10 Tesla for typical self-assembled dots. We use harmonic
potentials to model the confining of electrons, and calculate the exchange J
using the Heitler-London and Hund-Mulliken technique, including the long-range
Coulomb interaction. With our results we provide experimental criteria for the
distinction of singlet and triplet states and therefore for microscopic spin
measurements. In the case where dots of different sizes are coupled, we present
a simple method to switch on and off the spin coupling with exponential
sensitivity using an in-plane electric field. Switching the spin coupling is
essential for quantum computation using electronic spins as qubits.Comment: 13 pages, 9 figure
A self-interaction corrected pseudopotential scheme for magnetic and strongly-correlated systems
Local-spin-density functional calculations may be affected by severe errors
when applied to the study of magnetic and strongly-correlated materials. Some
of these faults can be traced back to the presence of the spurious
self-interaction in the density functional. Since the application of a fully
self-consistent self-interaction correction is highly demanding even for
moderately large systems, we pursue a strategy of approximating the
self-interaction corrected potential with a non-local, pseudopotential-like
projector, first generated within the isolated atom and then updated during the
self-consistent cycle in the crystal. This scheme, whose implementation is
totally uncomplicated and particularly suited for the pseudopotental formalism,
dramatically improves the LSDA results for a variety of compounds with a
minimal increase of computing cost.Comment: 18 pages, 14 figure
The Behavioral Roots of Information Systems Security:Exploring Key Factors Related to Unethical IT Use
Unethical information technology (IT) use, related to activities such as hacking, software piracy, phishing, and spoofing, has become a major security concern for individuals, organizations, and society in terms of the threat to information systems (IS) security. While there is a growing body of work on this phenomenon, we notice several gaps, limitations, and inconsistencies in the literature. In order to further understand this complex phenomenon and reconcile past findings, we conduct an exploratory study to uncover the nomological network of key constructs salient to this phenomenon, and the nature of their interrelationships. Using a scenario-based study of young adult participants, and both linear and nonlinear analyses, we uncover key nuances of this phenomenon of unethical IT use. We find that unethical IT use is a complex phenomenon, often characterized by nonlinear and idiosyncratic relationships between the constructs that capture it. Overall, ethical beliefs held by the individuals, along with economic, social, and technological considerations are found to be relevant to this phenomenon. In terms of practical implications, these results suggest that multiple interventions at various levels may be required to combat this growing threat to IS security
The delivery of personalised, precision medicines via synthetic proteins
Introduction:
The design of advanced drug delivery systems based on synthetic and su-pramolecular chemistry has been very successful. Liposomal doxorubicin (CaelyxÂź), and liposomal daunorubicin (DaunoXomeÂź), estradiol topical emulsion (EstrasorbTM) as well as soluble or erodible polymer systems such as pegaspargase (OncasparÂź) or goserelin acetate (ZoladexÂź) represent considerable achievements.
The Problem:
As deliverables have evolved from low molecular weight drugs to biologics (currently representing approximately 30% of the market), so too have the demands made of advanced drug delivery technology. In parallel, the field of membrane trafficking (and endocytosis) has also matured. The trafficking of specific receptors i.e. material to be recycled or destroyed, as well as the trafficking of protein toxins has been well characterized. This, in conjunction with an ability to engineer synthetic, recombinant proteins provides several possibilities.
The Solution:
The first is using recombinant proteins as drugs i.e. denileukin diftitox (OntakÂź) or agalsidase beta (FabrazymeÂź). The second is the opportunity to use protein toxin architecture to reach targets that are not normally accessible. This may be achieved by grafting regulatory domains from multiple species to form synthetic proteins, engineered to do multiple jobs. Examples include access to the nucleocytosolic compartment. Herein the use of synthetic proteins for drug delivery has been reviewed
Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology
notes: As the primary author, OâMalley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. âMacrobeâ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes â the dominant life form on the planet, both now and throughout evolutionary history â will transform some of the philosophy of biologyâs standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology â including biofilm formation, chemotaxis, quorum sensing and gene transfer â that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations
Search for oscillations using inclusive lepton events
A search for Bs oscillations is performed using a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to previous inclusive lepton analyses, the prop er time resolution and b-flavour mistag rate are significantly improved. Additional sensitivity to Bs mixing is obtained by identifying subsamples of events having a Bs purity which is higher than the average for the whole data sample. Unbinned maximum likelihood amplitude fits are performed to derive a lower limit of Dms>9.5 ps-1 at 95% CL. Combining with the ALEPH Ds based analyses yields Dms>9.6 ps-1 at 95% CL.A search for B0s oscillations is performed using a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to previous inclusive lepton analyses, the proper time resolution and b-flavour mistag rate are significantly improved. Additional sensitivity to B0s mixing is obtained by identifying subsamples of events having a B0s purity which is higher than the average for the whole data sample. Unbinned maximum likelihood amplitude fits are performed to derive a lower limit of Deltam_s>9.5ps^-1 at 95% CL. Combining with the ALEPH D-s based analyses yields Deltam_s>9.6ps^-1 at 95% CL
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