Broker Positions in Task-Specific Knowledge Networks

In this paper we empirically investigate various benefits and costs associated with broker characteristics of individuals who operate in the account management system of financial service providers. We narrow our focus to broker positions in two specific task-specific knowledge networks that facilitate account management. We study the effect of broker positions on the contribution of individuals to organizational performance. We measure such a contribution by measuring the perceptions of others concerning a particular individual. We also explore how certain personal costs are associated with these task-specific broker positions. More specifically, we explore how these positions affect role ambiguity and role conflict, as self-perceived by that particular individual. To test the hypothesized effects we collect data for a network consisting of 55 individuals. We conclude with stating that service specification broker positions benefit organizations, but service delivery broker positions are detrimental to an organization and that they also invoke personal costs.social networks;account management;role stress;task-specific broker positions

Charge transfer via a two-strand superexchange bridge in DNA

Charge transfer in a DNA duplex chain is studied by constructing a system with virtual electrodes connected at the ends of each DNA strand. The systeym is described by the tight-binding model and its transport is analyzed by the transfer matrix method. The very weak distance dependence in long (G:C)(T:A)_M(G:C)_3 DNA chain observed in experiment [B. Giese, et al., Nature 412, 318 (2001)] is explained by a unistep two-strand superexchange bridge without the need for the multi-step thermally-induced hopping mechanism or the dephasing effect. The crossover number M_c of (T:A) base pairs, where crossover between strong and weak distance dependence occurs, reflects the ratio of intra- and inter-strand neighboring base-base couplings.Comment: accepted for publication in Phys. Rev. Let

Marine Protected Areas and commercial fisheries: the existing fishery in potential protected areas, and a modelling study of the impact of protected areas on North Sea Plaice

Dit rapport presenteert resultaten van onderzoek, dat in 2005/2006 is uitgevoerd. In het kader van de Europese Vogel en Habitat Richtlijnen dienen lidstaten te beschermen gebieden op zee aan te wijzen, wat mogelijk zou leiden tot beperkingen van visserijactiviteiten in deze gebieden. De vraag was, welke invloed dit zou hebben op de vis en visserij. In dit onderzoek is enerzijds een statische beschrijving opgesteld van de visserijinspanning en de vangsten in de voorgestelde gebieden, en is anderzijds een eerste analyse (simulatie-model) opgezet van het lange-termijn effect op migrerende vis (schol). Dit onderzoek werd eind 2006 afgerond met een concept-rapport

Elastic constants of nematic liquid crystalline Schiff’s bases

The three elastic constants of a number of structurally related nematic liquid crystalline Schiff’s bases have been measured as a function of temperature. The results are new in the sense that they exhibit a clear distinction in behavior between compounds with a rigid molecular structure and compounds with a molecular structure consisting of a rigid core and a flexible alkyl chain. In particular, it has been found that the ratio of the bend and splay elastic constants K3/K1 increases for compounds with a rigid molecular structure with increasing length to width ratio. This trend is the reverse of that observed wihin homologous series, for which K3/K1 has been found to decrease with increasing length of the alkyl chain. New is the experimental finding that the twist elastic constant K2 of the homologs studied is independent of the length of the alkyl chain. Finally, the experiments show that the average elastic constant K̄1+K2+K3)/3 is proportional to the smectic–isotropic transition temperature. The results can only be partly understood within the framework of existing theoretical models

Self Phase Modulation and Stimulated Raman Scattering due to High Power Femtosecond Pulse Propagation in Silicon-on-Insulator Waveguides.

Self Phase Modulation (SPM) and Stimulated Raman Scattering (SRS) in silicon waveguides have been observed and will be discussed theoretically using a modified Nonlinear Schrödinger Equation. The high optical peak powers needed for the experiments were obtained by coupling sub-picosecond (200fs) transform limited pulses with a spectral width of 12nm into a single mode silicon waveguide. Spectral broadening up to 50nm has been observed due to Self Phase Modulation. An intensity increase of the idler spectrum around 1650nm at the expense of the 1550nm pump signal has been observed as function of pump power, indicating the presence of Stimulated Raman Scattering

Simultaneous Optimization of Block Replacement and Spare Part Ordering TIME for a Multi Component System with Separate Spare Part Ordering for Block and Failure Replacements

A block replacement schedule can be optimized simultaneously with a spare parts ordering schedule, since all items are replaced at a constant interval. The solution of joint optimization for spare parts ordering time and block replacement gives lower costs compared to separate optimization of ordering time and replacement time. The spare parts for replacement can be classified as stochastic demand for failure replacement and deterministic demand for block replacement. In this paper, we propose a simulation model for a separate spare parts ordering schedule. The solution was compared to the solution for a model with common spare parts for both failure and block replacement. The system has N identical components, each with a Weibull lifetime distribution. The costs of failure and block replacements, and also the costs of ordering, holding and shortage of spare parts are given. The proposed model was shown to perform better than the common order model. Also, compared to the age replacement model, the solution of the proposed model is relatively similar, yet the economies of scale would be an advantage for the block replacement over age replacement

Extra care : viable for couples living with dementia?

Purpose: The perspectives of people with dementia and their care partners regarding ‘extra care’ housing are currently unknown. This paper will report findings of a consultation study exploring the perceived barriers and facilitators of a relocation to extra care housing, from the perspective of people living with dementia, and their care partners. Design/methodology/approach: Fieldwork consisted of paired or 1-1 interviews and small focus groups with potential users of an alternative model of extra care support for people living with dementia in the South of England. The consultation took place between June and August 2013. The interviews and focus groups were audio recorded, transcribed verbatim. The transcripts were analysed thematically. Findings: Benefits of extra care were identified as the opportunity for couples to remain living together for longer, creating a supportive, dementia-friendly community, and a reduction in the strain experienced by the care partners. Barriers centred on a sense of loss, stress and uncertainty. Living and caring at home was perceived as preferable to shared care. Research limitations/implications: The findings presented here have limited generalizability for two reasons. First the shared care approach consulted on was very specific. Second our participants form a purposive sample and as such are not representative of a wider population. Despite best intentions the voice of people with dementia are under reported in this consultation. Only one person with early on-set dementia was interviewed and the remaining two people with dementia were interviewed alongside their care partner. Practical implications: The findings cast doubt on the viability of extra care facilities, designed for couples living with dementia, if extra care continues to be conceptualised and marketed as a preventative lifestyle choice. The findings indicate the value of consulting with people with dementia, and their care partners, when designing new forms of housing with care specifically for people living with dementia. Originality/value: This paper contributes to the body of literature, exploring the feasibility of new and innovative alternative care and housing options, for people with dementia. This paper is one of the first to explore extra care as a housing and social care option for couples with dementia

Self-organization of hydrophobic soil and granular surfaces

Soil can become extremely water repellent following forest fires or oil spillages, thus preventing penetration of water and increasing runoff and soil erosion. Here the authors show that evaporation of a droplet from the surface of a hydrophobic granular material can be an active process, lifting, self-coating, and selectively concentrating small solid grains. Droplet evaporation leads to the formation of temporary liquid marbles and, as droplet volume reduces, particles of different wettabilities compete for water-air interfacial surface area. This can result in a sorting effect with self-organization of a mixed hydrophobic-hydrophilic aggregate into a hydrophobic shell surrounding a hydrophilic core