Induced magnetosphere of Venus

Solar wind and ionospheric conductivity studied for role in inducing Venus or Mars magnetosphere

Assessing the role of dispersed floralresources for managed bees in providingsupporting ecosystem services for croppollination

Most pollination ecosystem services studies have focussed on wild pollinators and their dependence on natural floral resources adjacent to crop fields. However, managed pollinators depend on a mixture of floral resources that are spatially separated from the crop field. Here, we consider the supporting role these resources play as an ecosystem services provider to quantify the use and availability of floral resources, and to estimate their relative contribution to support pollination services of managed honeybees. Beekeepers supplying pollination services to the Western Cape deciduous fruit industry were interviewed to obtain information on their use of floral resources. For 120 apiary sites, we also analysed floral resources within a two km radius of each site based on geographic data. The relative availability of floral resources at sites was compared to regional availability. The relative contribution of floral resources-types to sustain managed honeybees was estimated. Beekeepers showed a strong preference for eucalypts and canola. Beekeepers selectively placed more hives at sites with eucalypt and canola and less with natural vegetation. However, at the landscape-scale, eucalypt was the least available resource, whereas natural vegetation was most common. Based on analysis of apiary sites, we estimated that 700,818 ha of natural vegetation, 73,910 ha of canola fields, and 10,485 ha of eucalypt are used to support the managed honeybee industry in the Western Cape. Whereas the Cape managed honeybee system uses a bee native to the region, alien plant species appear disproportionately important among the floral resources being exploited. We suggest that an integrated approach, including evidence from interview and landscape data, and fine-scale biological data is needed to study floral resources supporting managed honeybees

The child psychotherapists' role in consultation work with the professional network around looked after children

Consultation with the network around a child is a core aspect of a child psychotherapist’s role; however, little has been written about this aspect of their work with looked after children. Aims: To gain an understanding of child psychotherapists’ work with the network around looked after children, and what they see as specific to the psychoanalytic approach. Methods: Nine participants with expertise in working with foster carers and looked after children’s professionals, participated in in-depth interviews. Results: Thematic analysis identified three themes concerned with the tensions child psychotherapists hold within themselves whilst consulting to the network around looked after children. The first theme encapsulates participants’ sense of dilemma between what they felt was demanded of them versus what they could offer. The second theme describes participants’ sense of tensions around the way the system is organised versus what they felt is in the best interests of the child and network. The third theme captures participants’ views about whether their consultant role fits a generic model of reflective practice similar to that offered by professionals from other disciplines, or whether the psychoanalytic approach brings something distinctive to this model of consultation. Links to existing theory and practice implications are discussed

Spectral Analysis of a Four Mode Cluster State

We theoretically evaluate the squeezed joint operators produced in a single optical parametric oscillator which generates quadripartite entangled outputs, as demonstrated experimentally by Pysher et al. \cite{pysher}[Phys. Rev. Lett. 107, 030505 (2011)]. Using a linearized fluctuation analysis we calculate the squeezing of the joint quadrature operators below threshold for a range of local oscillator phases and frequencies. These results add to the existing theoretical understanding of this potentially important system.Comment: 4 pages, 6 figure

The influence of organizational structure on international purchasing success

International purchasing is one of the most important strategic topics for managers and attracts more and more interest among researchers. Yet, research often lacks strong theoretical and systematic insights on the intricacies of purchasing success and does not make enough use of advanced empirical methods. We apply a structural equation modeling technique to better research into the intricacies of higher or lower purchasing performance owing to different organizational design choices. We build our model on the resource-based view and on transaction cost economics and make use of survey data of purchasers engaging in international sourcing activities. We find four important drivers of purchasing performance, namely specialization, configuration, standardization and centralization. The importance of these drivers seems to be contingent on the sourcing environments, namely on the characteristics attributed to high cost and low cost countries

Exploring the significance of land-cover change in South Africa

Changing land cover is a phenomenon that is growing in magnitude and significance, both globally1 and in South Africa2 . Changes in land cover include the conversion of natural vegetation to agricultural crops and forest plantations, changes to natural vegetation through bush encroachment and overgrazing, soil erosion, invasion by alien plant species, and accelerating urbanisation. Land-cover changes increasingly relate to climate and atmospheric changes in ways that are currently poorly understood but potentially significant, especially in terms of compromising or enhancing the delivery of vital ecosystem services from rangelands, agricultural croplands, water catchments and conservation areas. Land-cover change is being studied in different ways, and at different scales, by ecologists, plant physiologists, applied biologists and social scientists. A core group of scientists has recently formed the Land Cover Change Consortium (LCCC), which aims to begin integrating the results of the varied approaches to studying land-cover change, and to guide future research directions, with a view to building a better science base for informing policy and management decision-making in conservation, agriculture and environmental management. The group has developed a simple conceptual outline that links field experiments, observation and monitoring, modelling and prediction of land-cover change (Figure 1), and is currently developing a funding base to support collaboration in addressing fundamental questions about how ecosystems might change in the coming decades, in training new graduates, and in communicating effectively with policymakers. The LCCC hopes to provide a theoretical and practical multidisciplinary platform for scientific collaboration on global change issues that also includes different stakeholder groups and contributes to policy and decision-making. Multidisciplinary collaboration is notoriously challenging, but holds great promise for novel insights

Quadripartite continuous-variable entanglement via quadruply concurrent downconversion

We investigate an intra-cavity coupled down-conversion scheme to generate quadripartite entanglement using concurrently resonant nonlinearities. We verify that quadripartite entanglement is present in this system by calculating the output fluctuation spectra and then considering violations of optimized inequalities of the van Loock-Furusawa type. The entanglement characteristics both above and below the oscillation threshold are considered. We also present analytic solutions for the quadrature operators and the van Loock-Furusawa correlations in the undepleted pump approximation.Comment: 9 pages, 5 figure

Ecological aspects of the substrate and water relations of deciduous and evergreen plant forms in the western Karoo

The principle aim of this work was to ascertain the relative importance of water and nutrient supply in determining the success of deciduous and evergreen plant forms on two main substrate types in the Worcester-Robertson valley, situated in the Succulent Karoo Biome. The substrate types selected for study represent soils of zoogenic soil mounds (locally termed "heuweltjies", and often referred to in the literature as "Mirna-like" mounds), and soils immediately adjacent to and surrounding the soil mounds. The distribution of deciduous and evergreen plant forms in the Worcester-Robertson valley was analys~d relative to the selected substrate types. Foliar elemental concentrations of four selected species growing on both substrates at five separate sites within the valley were determined. Also, the patterns of seasonal water stress exhibited by three deciduous and five evergreen non-succulent woody perennials growing in both substrates were investigated on high radiation (equator-facing) and low radiation (pole-facing) slopes at one intensive study site, the Worcester Veld Reserve

Formative versus reflective measurement models: Two applications of formative measurement

This paper presents a framework that helps researchers to design and validate both formative and reflective measurement models. The framework draws from the existing literature and includes both theoretical and empirical considerations. Two important examples, one from international business and one from marketing, illustrate the use of the framework. Both examples concern constructs that are fundamental to theory-building in these disciplines, and constructs that most scholars measure reflectively. In contrast, applying the framework suggests that a formative measurement model may be more appropriate. These results reinforce the need for all researchers to justify, both theoretically and empirically, their choice of measurement model. Use of an incorrect measurement model undermines the content validity of constructs, misrepresents the structural relationships between them, and ultimately lowers the usefulness of management theories for business researchers and practitioners. The main contribution of this paper is to question the unthinking assumption of reflective measurement seen in much of the business literature