Wild Bee Conservation within Urban Gardens and Nurseries: Effects of Local and Landscape Management

Across urban environments, vegetated habitats provide refuge for biodiversity. Gardens (designed for food crop production) and nurseries (designed for ornamental plant production) are both urban agricultural habitats characterized by high plant species richness but may vary in their ability to support wild pollinators, particularly bees. In gardens, pollinators are valued for crop production. In nurseries, ornamental plants rarely require pollination; thus, the potential of nurseries to support pollinators has not been examined. We asked how these habitats vary in their ability to support wild bees, and what habitat features relate to this variability. In 19 gardens and 11 nurseries in California, USA, we compared how local habitat and landscape features affected wild bee species abundance and richness. To assess local features, we estimated floral richness and measured ground cover as proxies for food and nesting resources, respectively. To assess landscape features, we measured impervious land cover surrounding each site. Our analyses showed that differences in floral richness, local habitat size, and the amount of urban land cover impacted garden wild bee species richness. In nurseries, floral richness and the proportion of native plant species impacted wild bee abundance and richness. We suggest management guidelines for supporting wild pollinators in both habitats.DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

Diffuse interface models of locally inextensible vesicles in a viscous fluid

We present a new diffuse interface model for the dynamics of inextensible vesicles in a viscous fluid. A new feature of this work is the implementation of the local inextensibility condition in the diffuse interface context. Local inextensibility is enforced by using a local Lagrange multiplier, which provides the necessary tension force at the interface. To solve for the local Lagrange multiplier, we introduce a new equation whose solution essentially provides a harmonic extension of the local Lagrange multiplier off the interface while maintaining the local inextensibility constraint near the interface. To make the method more robust, we develop a local relaxation scheme that dynamically corrects local stretching/compression errors thereby preventing their accumulation. Asymptotic analysis is presented that shows that our new system converges to a relaxed version of the inextensible sharp interface model. This is also verified numerically. Although the model does not depend on dimension, we present numerical simulations only in 2D. To solve the 2D equations numerically, we develop an efficient algorithm combining an operator splitting approach with adaptive finite elements where the Navier-Stokes equations are implicitly coupled to the diffuse interface inextensibility equation. Numerical simulations of a single vesicle in a shear flow at different Reynolds numbers demonstrate that errors in enforcing local inextensibility may accumulate and lead to large differences in the dynamics in the tumbling regime and differences in the inclination angle of vesicles in the tank-treading regime. The local relaxation algorithm is shown to effectively prevent this accumulation by driving the system back to its equilibrium state when errors in local inextensibility arise.Comment: 25 page

Regulated Expansion of Electricity Transmission Networks: The Effects of Fluctuating Demand and Wind Generation

We study the performance of different regulatory approaches for the expansion of electricity transmission networks in the light of realistic demand patterns and fluctuating wind power. In particular, we are interested in the relative performance of a combined merchant-regulatory mechanism compared to a cost-based and a merchant-like approach. In contrast to earlier research, we explicitly include both an hourly time resolution and fluctuating wind power, which allows representing demand in a very realistic way. This substantially increases the real-world applicability of results compared to previous analyses, which were based on simplifying assumptions. We show that a combined merchant-regulatory regulation, which draws on a cap over the two-part tariff of the Transco, leads to welfare outcomes far superior to the modeled alternatives. This result proves to be robust over a range of different cases and sensitivity analyses. We also find that the intertemporal rebalancing of the two-part tariff carried out by the Transco so as to expand the network is such that the fixed tariff part turns out to be relatively large compared to extension costs.Electricity, Regulation, Transmission Expansion, Wind Power

The Golgin GMAP-210

The protein GMAP-210 (Golgi Microtubule Associated Protein of 210 kDa) is a long coiled-coil protein, which localises to the Golgi apparatus. It is part of the loosely defined protein group of the golgins, which are involved in establishing the Golgi morphology and in vesicular trafficking around the Golgi. By using biochemical, cell biological and molecular biological methods GMAP-210 was examined in regards to its Golgi targeting capability, its interaction partners and its function in establishing Golgi morphology and positioning. In vitro and in vivo experiments showed that GMAP-210 targets to the Golgi via its C-terminal GRAB domain. Its proposed interaction with Arf1, however, could not be definitely determined, although there is strong evidence for it. Arf1 binding to the GRAB domain was hindered in the full-length protein, but not with short C-terminal fragments containing the minimal GRAB domain. This implies that additional factors are needed for GMAP-210 Golgi binding. A yeast 2-hybrid screen of the entire family of small Rab GTPases identified the Golgi and ER localised Rab1 as a novel interaction partner of GMAP-210. GMAP-210 also labels vesicular tubular structures in the cell, which partially overlap with COPII and ERGIC53, components of the early secretory pathway. This gives additional evidence that GMAP- 210 is involved in ER to Golgi transport. Trafficking of a model substrate, the vesicular stomatitis virus G-protein (VSV-G), however, was not impaired in the absence of GMAP- 210. This indicates that GMAP-210 functions only in specialised transport pathways. Knockdown of GMAP-210 in HeLa L cells by siRNA changed the Golgi morphology and the Golgi fragmented into a cluster of vesicles. Its overexpression caused the Golgi to grow long tubular structures. Both effects on morphology could only be observed in HeLa L cells, not in hTERT-RPE1 cells. As direct interaction with microtubules or γ-tubulin could not be detected, and GMAP-210 is therefore unlikely to affect Golgi morphology by directly perturbing microtubule function. GMAP-210 knockdown by siRNA also showed its interaction with the intraflagellar transport protein IFT20. This protein lost its Golgi localisation when GMAP-210 was depleted. Both proteins interacted directly. GMAP-210, however, was not involved in primary cilium formation in hTERT-RPE1 cells and loss of IFT20 from the Golgi did not impair formation of the cilium, proposing that the Golgi pool of IFT20 had a function apart from intraflagellar transport and formation of the primary cilium. These results set GMAP-210 apart from the archetypal golgins GM130 and p115 and indicate that GMAP-210 is involved in a highly specialised transport pathway, which could nevertheless influence the morphology of the Golgi apparatus in certain cell types

Capital markets, financial intermediaries, and corporate governance : an empirical assessment of the top ten voucher funds in the Czech Republic

Voucher privatization was expected to result in widely dispersed ownership with little effect on firms'governance. But in the first wave of privatization, more than 70 percent of Czech vouchers went to investment funds and the 10 largest Czech and Slovak investment funds (surveyed for this study) acquired roughly half of all voucher points. And the large funds can influence corporate governance. Also, a fund's actual role depends on the sponsoring institution's or individual's incentives structure. Banks and investment funds lack the skills and incentives to initiate corporate restructuring, but funds with significant stakes can readily compare managers'performance and remove underperforming executives and can counterbalance the control of management and employees. Funds can also effectively monitor firms on behalf of groups of small investors. After privatization, most Czech assets are now owned by funds affiliated with banks. In market economies, a close relationship between banks and enterprises can be seen as a conflict of interest. In transition economies, banks and funds have spontaneously developed a relationship as a way for banks to get information about firm performance. Bank-sponsored funds reduce banks'information and monitoring costs and hence lending risk and costs. They also facilitate the informal workout of problem loans.International Terrorism&Counterterrorism,Payment Systems&Infrastructure,Economic Theory&Research,Economic Adjustment and Lending,Banks&Banking Reform,International Terrorism&Counterterrorism,Economic Theory&Research,Banks&Banking Reform,Payment Systems&Infrastructure,Economic Adjustment and Lending

Clarifying researchers’ subjectivity in qualitative addiction research

Aim: In addiction research, non-constructionist traditions often question the validity and reliability of qualitative efforts. This study presents techniques that are helpful for qualitative researchers in dissecting and clarifying their subjective interpretations. Methods: We discuss three courses of action for inspecting researchers’ interpretations when analysing focus-group interviews: (i) adapted summative content analysis, (ii) quantification of researchers’ expectations; and, (iii) speaker positions. While well-known methodological techniques in their own rights, we demonstrate how they can be used to complement one another. Results: Quantifications are easy and expeditious verification techniques, but they demand additional investigation of speaker positions. A combination of these techniques can strengthen validity and reliability without compromising the nature of constructionist and inductive enquiries. Conclusions: The three techniques offer valuable support for the communication of qualitative work in addiction research. It allows researchers to assess and understand their own initial impressions during data collection and raw analysis. In addition, they also serve in making researchers’ subjectivity more transparent. All of this, without abandoning subjectivity, but rather making sense of it.Peer reviewe