As with other types of corporate social software, companies adopting enterprise microblogging find it hard to make sense of the new service. This comprises both integrating it into their work processes and shaping the implementation and adoption process so that envisioned usage practices evolve. In this paper we are investigating the use of microblogging at a large insurance company by means of genre analysis. We compare and contrast our findings with three similar studies we have conducted prior. We find a significant relationship between the organizational contexts and the related technologies-in-practice that have evolved in the different cases. It becomes clear that management cannot prescribe usage practices for open tools like enterprise microblogging. But management can shape the organizational context in which it is adopted. Thus, we discuss the concept of "cultivation" as a potential management approach for implementing enterprise microblogging successfully.

We present a detailed study of a phonon-assisted incoherent excitation mechanism of single quantum dots. A spectrally detuned continuous-wave laser couples to a quantum dot transition by mediation of acoustic phonons, whereby excitation efficiencies up to 20$%$ with respect to strictly resonant excitation can be achieved at $T=9$ K. Laser-frequency-dependent analysis of the quantum dot intensity distinctly maps the underlying acoustic phonon bath and shows good agreement with our polaron master equation theory. An analytical solution for the steady-state exciton density (which is proportional to the photoluminescence) is introduced which predicts a broadband incoherent coupling process mediated by electron-phonon scattering. Moreover, we investigate the coherence properties of the emitted light with respect to strictly resonant versus phonon-assisted excitation, revealing the importance of narrow band triggered emitter-state initialization for possible applications of a quantum dot exciton system as a qubit.

We report on the epitaxial growth of vertically stacked InP and In(Ga)As quantum dot (QD) layers to realize a triple dot quantum gate structure consisting of an asymmetric control double dot and a single target dot suitable for a CNOT gate structure. Structural analysis as well as studies on the optical properties are presented. For studies on control dot structures we analyze the growth of InP islands in a GaInP barrier on (100) GaAs substrates. By stacking InP QD layers with intentional asymmetric design in QD size of each layer and adjustment of the barrier width between the double dots, coupling and control of the coupling via barrier layer width‐design can be demonstrated. For defined gate action single dot spectra of aligned dots are indispensable. Therefore QD density reduction is studied. We study two possibilities to affect the QD density and control the dot site by manipulating the surface potential of InP island nucleation. (i) Growth of InP islands on top of a low density In(Ga)As QD seed layer (ii) Growth of InP islands on patterned (100) GaAs substrates. We present microsphere photolithography in combination with wet chemical etching as a fast and low‐cost method to produce regular hole arrays in a GaAs surface, which are suitable for controlled nucleation of self‐assembled InP islands.

An overview of the literature on Internet social networking (ISN) is presented. The authors identify four dominant streams of research and review the key contributions to the field. The review reveals that the research field is fragmented and does not yet facilitate a general understanding of the phenomenon. In particular research is very much skewed towards certain user groups (e. g., students) and platforms (in particular Facebook). Further, implications for a corporate context are discussed. In doing so, three contexts of application are differentiated: Social network sites (SNSs) for 1) recruiting and professional career development, 2) relationship facilitation in distributed work contexts, and 3) interactions with end customers. The authors discuss SNS potentials, implications of existing ISN research and future research opportunities. In summary, they seek to contribute to a better understanding of the phenomenon of ISN and to making available the current state of ISN research for the wider Enterprise 2.0 community.

Virtual organisation of work is not unproblematic. An extensive body of research exists on topics like virtual teams in enterprise contexts. Similarly, in a scientific context many studies analyse collaboration among scholars. However, most studies here focus on the macro level (e.g. policy issues and the organisation of research projects). The role of the individual scholar in this is vastly ignored. I present observations from a qualitative study investigating research collaboration in taking the perspective of individual scholars in the IS discipline. I explore the different contexts of interaction in which scholars execute collaboration, and also the emergence of scholars’ individual social networks. Further I analyse tool usage, specifically focusing on Social Software, which, comparable to enterprise contexts, is gaining increasing attention in the academic context. Based on my observations I present two sets of propositions aiming at the emergence of a scholar’s professional social network and an adequate usage of tools for supporting collaboration.

An overview of the literature on Internet social networking (ISN) is presented. The authors identify four dominant streams of research and review the key contributions to the field. The review reveals that the research field is fragmented and does not yet facilitate a general understanding of the phenomenon. In particular research is very much skewed towards certain user groups (e.g., students) and platforms (in particular Facebook). Further, implications for a corporate context are discussed. In doing so, three contexts of application are differentiated: Social network sites (SNSs) for 1) recruiting and professional career development, 2) relationship facilitation in distributed work contexts, and 3) interactions with end customers. The authors discuss SNS potentials, implications of existing ISN research and future research opportunities. In summary, they seek to contribute to a better understanding of the phenomenon of ISN and to making available the current state of ISN research for the wider Enterprise 2.0 community.

Zusammenfassung  Der Stand der Forschung zum Internet Social Networking (ISN) auf Basis von Social Network Sites (SNS) wird detailliert analysiert. Es werden vier maßgebliche Forschungsfelder identifiziert und die jeweils wichtigsten Erkenntnisse bisheriger Arbeiten diskutiert. Insgesamt ist die bisherige Forschung stark fragmentiert und beschränkt sich auf bestimmte Plattformen (insbes. Facebook) und Nutzergruppen (insbes. Studierende). Ein umfassendes Verständnis des Phänomens „Internet Social Networking“ liegt bisher nicht vor. Insbesondere die Frage der Gestaltung und Nutzung von SNSs als Teil des betrieblichen Informationssystems ist bisher kaum untersucht worden. Basierend auf dem aktuellen Forschungsstand werden beispielhaft Potenziale für den Einsatz von SNSs in Unternehmen abgeleitet. Hierbei wird zwischen drei Anwendungskontexten differenziert: 1) Mitarbeiterrekrutierung und Karriereförderung, 2) Unterstützung virtueller Arbeitskontexte sowie 3) Interaktion mit (End-)Kunden. Teilweise können relevante Fragen in den Anwendungskontexten auf Basis bisheriger Ergebnisse der ISN-Forschung erklärt werden. Im Wesentlichen zeigt sich aber spezifischer Forschungsbedarf, der durch die Studie charakterisiert werden kann. Der Beitrag zielt auf die Entwicklung einer Forschungsagenda für das Forschungsfeld ISN und macht die bisherigen Erkenntnisse für den Bereich des Enterprise 2.0 zugänglich.

Virtual Teams in enterprise contexts have been well researched. However when concerned with scientific research studies often focus on a macro level ignoring the individual perspective of scholars. I report in this paper on observations made in two case studies on research collaboration, one concentrated on a large research network and one on the situated context of IS scholars involved in collaboration. I find that the characteristics of virtual work in enterprise and academic contexts differ notably. Whereas literature on virtual teams in enterprise contexts proclaim a strong need for the support of relational and cognitive Social Capital, in academic contexts rather structural Social Capital seems to be missing. I further propose to consider Social Network Sites as a tool to support research collaboration, as this IT-artefact seems to positively affect the emergence and maintenance of structural Social Capital.

We present a method to reduce the intrinsically high InP quantum dot density embedded in a Ga0.51In0.49P barrier by introducing an InGaAs quantum dot seed layer. The additional strain reduces the total InP quantum dot density by around one order of magnitude from 2×1010 to 3×109 cm−2 but only ∼1% of the InP nanostructures seem to be optically active (107 cm−2). Therefore, microphotoluminescence measurements could be accomplished without masks. We found resolution-limited photoluminescence linewidths (ΔE<100 μeV), good signal-to-noise ratios (∼65), single-photon emission behavior [g(2)(τ=0)=0.3], and excitonic decay times of typically between 1 and 2 ns. Furthermore the structural quantum dot properties were investigated.

The title compound, C12H13ClN6, was prepared by reaction of 4,5-dichloro-7H-pyrrolo[2,3-d]pyrimidine with 2-(1H-imidazol-4-yl)-N-methylethanamine, and the X-ray study confirmed that chloro-substituent in six-membered ring was replaced in the reaction. The exocyclic N atom environment is approximately coplanar with the pyrrolo[2,3-d]pyrimidine [corresponding dihedral angle is 5.5 (1)°], whereas the mean plane of the N—C—C—C link connecting with the imidazolyl ring is almost exactly orthogonal to the plane of the bicyclic system [dihedral angle = 91.6 (2)°]. The imidazolyl plane itself, however, forms a relatively small dihedral angle of 20.8 (1)° with the pyrrolo[2,3-d]pyrimidine plane. There are two independent N—H⋯N hydrogen bonds in the structure, which link molecules into layers parallel to (03).

To achieve a low densitiy of optically active InP-quantum dots we used InGaAs islands embedded in GaAs as a seed layer. First, the structural InGaAs quantum dot properties and the influence of the annealing technique was investigated by atomic force microscope measurements. High-resolution micro-photoluminescence spectra reveal narrow photoluminescence lines, with linewidths down to 11 μeV and fine structure splittings of 25 μeV. Furthermore, using these InGaAs quantum dots as seed layer reduces the InP quantum dot density of optically active quantum dots drastically. InP quantum dot excitonic photoluminescence emission with a linewidth of 140 μeV has been observed.

Low density (∼107 cm − 2), small sized InGaAs quantum dots were grown on a GaAs substrate by metal–organic vapor-phase epitaxy and a special annealing technique. The structural quantum dot properties and the influence of the annealing technique was investigated by atomic force microscope measurements. High-resolution micro-photoluminescence spectra reveal narrow photoluminescence lines, with linewidths down to 11 µeV and fine structure splittings of 25 µeV. High signal to noise ratios (∼140) and a nearly background free autocorrelation measurement indicate an excellent optical quality and single photon emission behavior. Furthermore, time resolved measurements reveal excitonic decay times typically in the range between 800 and 2300 ps and biexcitonic decay times around 300 ps.

Social Network Sites (SNSs) are a success story by example. User counts as well as page visits have rocketed in recent years. In this paper we propose to utilize Transaction Cost Theory (TCT) and Social Capital Theory (SCT) to make sense of what kind of social interaction is executed on SNSs and why. In doing so we will show how TCT can be applied to SNSs by proposing to include in the theory the construct of social transactions. We will describe the characteristics of social transactions on SNSs as being concerned with the management of Social Capital. We will then determine which social transactions are attracted by SNSs. Finally, wwe discuss how research in the field of Internet Social Networking can benefit from this conceptualisation of social transactions and spell out practical implications.

Purpose:  Activation of ionotropic γ‐aminobutyric acid type A (GABAA) receptors induces in immature neocortical neurons a membrane depolarization that may contribute to the higher epilepsy susceptibility in newborns. To elucidate whether depolarizing GABAergic responses enhance or attenuate epileptiform activity in the immature neocortex, we investigated the effect of agonists, antagonists, and positive modulators of GABAA receptors on epileptiform activity.

Social Networking Sites (SNS) are one of the most popular business models on the Internet at the moment. At the same time, Social Networking is increasingly interesting as a topic of research in Information Systems. Drawing on existing research in the field, in this paper we propose to distinguish ISN (Internet Social Networking) as a phenomenon from its concrete manifestations in the various SNSs in the marketplace. On the basis of this distinction we take to the classification of SNSs grounded in real-life marketplace variety. In doing so, we identify seven different classes of SNSs. We argue that a typology of SNSs is useful for shaping our understanding of the diverse nature of ISN as existing in concrete manifestations. Most importantly, our classification makes accessible existing research for conceptually sound meta-analysis research. In order to fully grasp the phenomenon of ISN we also propose to include in the definition web sites that feature only certain aspects of ISN, while networking is not their core feature. Using our classification we discuss future research directions.