Electricity markets: Designing auctions where suppliers have uncertain costs

We analyse how the market design influences the bidding behaviour in multi-unit auctions, such as wholesale electricity markets. It is shown that competition improves for increased market transparency and we identify circumstances where the auctioneer prefers uniform to discriminatory pricing. We note that political risks could significantly worsen competition in hydro-dominated markets. It would be beneficial for such markets to have clearly defined contingency plans for extreme market situations.market transparenc

Equivariant quantization of orbifolds

Equivariant quantization is a new theory that highlights the role of symmetries in the relationship between classical and quantum dynamical systems. These symmetries are also one of the reasons for the recent interest in quantization of singular spaces, orbifolds, stratified spaces... In this work, we prove existence of an equivariant quantization for orbifolds. Our construction combines an appropriate desingularization of any Riemannian orbifold by a foliated smooth manifold, with the foliated equivariant quantization that we built in \cite{PoRaWo}. Further, we suggest definitions of the common geometric objects on orbifolds, which capture the nature of these spaces and guarantee, together with the properties of the mentioned foliated resolution, the needed correspondences between singular objects of the orbifold and the respective foliated objects of its desingularization.Comment: 13 page

Quantifying inbreeding avoidance through extra-pair reproduction

© 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.Peer reviewedPublisher PD

Is the Screening Test of the French Version of the Dementia Quality of Life Questionnaire Indispensable?

The aim of this study was to evaluate the usefulness of the screening questions in the French version of the Dementia Quality of Life (DQoL) questionnaire. To assess the psychometric properties of the French DQoL, 155 patients with mild-to-moderate dementia were recruited. Here, we compared the psychometric properties of the instrument between patients who passed the screening test (n = 109) and the whole study population (n = 155). The French DQoL version showed a good test-retest reliability at a 2-week interval (0.95 ≤ intraclass correlation coefficients ≤ 1.0), and an average internal consistency (0.58 ≤ Cronbach's α ≤ 0.87) for the 2 study groups. Significant differences were observed in the 2 groups for 4 dimensions of the DQoL regarding dementia severity (Cornell scale), and for 3 dimensions evaluating depression (MMSE). Convergent validity with the Duke Health Profile revealed many significant correlations between dimensions not only in the 109 patients, but also in the whole study population. Our study demonstrated that patients who failed the screening procedure nonetheless seemed to be able to answer the DQoL questionnaire, the whole study group showing acceptable psychometric properties

New evidence for Dicke's superradiance in the 6.7 GHz methanol spectral line in the interstellar medium

We present new evidence for superradiance (SR) in the methanol 6.7 GHz spectral line for three different star-forming regions: S255IR-NIRS3, G24.329+0.144, and Cepheus A. Our analysis shows that some of the flux–density flares exhibiting fast rise times and asymmetric light curves reported in these sources can naturally be explained within the context of SR. When a threshold for the inverted population column density is exceeded in a maser-hosting region, the radiation mode switches from one regulated by stimulated emission (maser) to SR. Superradiance, as a more efficient energy release mechanism, manifests itself through strong bursts of radiation emanating from spatially compact regions. Elevated inverted population densities and the initiation of SR can be due to a change in radiative pumping. Here, we show that an increase in the pump rate and the inverted population density of only a factor of a few results in a significant increase in radiation. While the changes in the pump rate can take place over a few hundred days, the rise in radiation flux density when SR is initiated is drastic and happens over a much shorter time-scale

Sex-specific additive genetic variances and correlations for fitness in a song sparrow (Melospiza melodia) population subject to natural immigration and inbreeding

ACKNOWLEDGMENTS We thank the Tsawout and Tseycum First Nation bands for access to Mandarte and everyone who contributed to the long-term data collection. We thank the European Research Council for funding and the University of Aberdeen for generous access to the Maxwell High Performance Computing cluster. Pierre de Villemereuil, Michael B. Morrissey, and Jarrod D. Hadfield provided enlightening discussions during manuscript preparation. Joel McGlothlin and two anonymous reviewers provided further helpful comments. DATA ARCHIVING Data have been archived in the Dryad Digital Repository: https://doi.org/10.5061/dryad.p7p1jb3 (Wolak et al. 2018).Peer reviewedPostprintPostprintPublisher PD

A NARRATIVE IN RELIEF The Historiography of English Modern Painting (1910-1915), from the 1910s to the 1950s

The groups of painters in England who experimented with new visual expressions of modernity between 1910 and 1915 are the subject of this historiographical research. More precisely, the accounts of Vorticism, Bloomsbury post-Impressionism and the modern art of painters associated with Sickert, (principally the Camden Town Group), have been critically examined over a forty year period in order to trace the narrative of their place in contemporary art criticism and their entry into histories of what soon became the recent past. This textually-based methodology has produced an insight into the forces acting upon the critical reception of a particular period subsequently seen by historians as a discrete phase in the evolution of British art. The readings of texts are organised chronologically so as to illustrate the formation of a historical narrative and its variants, and to show how immediate responses and retrospective evaluations connect discursively. The findings of the research have four aspects. Firstly, it has been fruitful to isolate the narrative of the years 1910-15 over forty years so as to test whether it is possible, using this longitudinal methodology, to comment productively on the integrity of this historical episode, and to establish how the narrative became a critical orthodoxy governed by a limited range of analytical perspectives. Secondly, estimations as to the quality of the art produced in these years developed a distinct, often negative, patterning in journalism and art historical writing and this is also traced in some detail over time. Dominant tropes in the critical language have been identified over this forty year period which became the default positions of historical analysis and which, I argue, impeded sophisticated or revisionist thinking. With a few notable exceptions, the analysis of early English modern art is poorly served by its commentators in this period and this weakened discursive health. Thirdly, this thesis also considers the nature and influence of, periodicals, newspapers, 'little magazines' and the genres of art-writing that were extant between 1910 and 1956 and relates this to the distinctions and similarities between art criticism and art history at this time. A fourth analytic strand concerns outside influences on the production of critical and historical texts. lt explores the impact of promotional art writing, and exposes the professional pressures on, and rivalries between, writers and considers some of the wider political circumstances through which this particular debate on recent art was refracted

Molten Salt Thermal Energy Storage Systems

The feasibility of storing thermal energy at temperatures of 450 C to 535 C in the form of latent heat of fusion was examined for over 30 inorganic salts and salt mixtures. Alkali carbonate mixtures were chosen as phase-change storage materials in this temperature range because of their relatively high storage capacity and thermal conductivity, moderate cost, low volumetric expansion upon melting, low corrosivity, and good chemical stability. Means of improving heat conduction through the solid salt were explored

Pair formation and collapse in imbalanced Fermion populations with unequal masses

We present an exact Quantum Monte Carlo study of the effect of unequal masses on pair formation in Fermionic systems with population imbalance loaded into optical lattices. We have considered three forms of the attractive interaction and find in all cases that the system is unstable and collapses as the mass difference increases and that the ground state becomes an inhomogeneous collapsed state. We also address the question of canonical vs grand canonical ensemble and its role, if any, in stabilizing certain phases

Immigration counter-acts local micro-evolution of a major fitness component : migration-selection balance in free-living song sparrows

Acknowledgements: We thank the Tsawout and Tseycum First Nations Bands for allowing access to Mandarte, everyone who contributed to long-term data collection, NSERC (Canada), the Swiss National Science Foundation (recently P400PB-180870), the Research Council of Norway (SFF-III, project 223257) and NTNU for funding. The authors declare no conflicts of interest.Peer reviewedPublisher PD