Price regulation of pluralistic markets subject to provider collusion

We analyse incentives for collusive behaviour when heterogeneous providers are faced with regulated prices under two forms of yardstick competition, namely discriminatory and uniform schemes. Providers are heterogeneous in the degree to which their interests correspond to those of the regulator, with close correspondence labelled altruism. Deviation of interests may arise as a result of de-nationalisation or when private providers enter predominantly public markets. We assess how provider strategies and incentives to collude relate to provider characteristics and across different market structures. We differentiate between “pure” markets with either only self-interested providers or with only altruistic providers and “pluralistic” markets with a mix of provider type. We find that the incentive for collusion under a discriminatory scheme increases in the degree to which markets are self-interested whereas under a uniform scheme the likelihood increases in the degree of provider homogeneity. Providers’ choice of cost also depends on the yardstick scheme and market structure. In general, costs are higher under the uniform scheme, reflecting its weaker incentives. In a pluralistic market under the discriminatory scheme each provider’s choice of cost is decreasing in the degree of the other provider’s altruism, so a self-interested provider will operate at a lower cost than an altruistic provider. Under the uniform scheme providers always choose to operate at the same cost. The prospect of defection serves to moderate the chosen level of operating cost.

DAMEWARE - Data Mining & Exploration Web Application Resource

Astronomy is undergoing through a methodological revolution triggered by an unprecedented wealth of complex and accurate data. DAMEWARE (DAta Mining & Exploration Web Application and REsource) is a general purpose, Web-based, Virtual Observatory compliant, distributed data mining framework specialized in massive data sets exploration with machine learning methods. We present the DAMEWARE (DAta Mining & Exploration Web Application REsource) which allows the scientific community to perform data mining and exploratory experiments on massive data sets, by using a simple web browser. DAMEWARE offers several tools which can be seen as working environments where to choose data analysis functionalities such as clustering, classification, regression, feature extraction etc., together with models and algorithms.Comment: User Manual of the DAMEWARE Web Application, 51 page

Mechanism of photoluminescence in intrinsically disordered CaZrO3 crystals: First principles modeling of the excited electronic states

CaZrO3 (CZO) powders obtained by the polymeric precursor method at 400 °C, and then, the samples were annealed at different temperatures (400, 600, 800, and 1000 °C) and characterized by X-ray diffraction, Raman and ultraviolet–visible spectroscopic methods, along with photoluminescence (PL) emissions. First principle calculations based on the density functional theory (DFT), using a periodic cell models, provide a theoretical framework for understanding the PL spectra based on the localization and characterization of the ground and electronic excited states. Fundamental (singlet, s) and excited (singlet, s*, and triplet, t*) electronic states were localized and characterized using the ideal and distorted structures of CZO. Their corresponding geometries, electronic structures, and vibrational frequencies were obtained. A relationship between the different morphologies and structural behavior has also been established. Polarized structures were identified by the redistribution of the 4dz2, 4dyz, and 4dxy (Zr) orbitals at the conduction band and the 2pz (O) orbital in the valence band for s, s* and t*. Analysis of the vibrational eigenvector modes of these electronic states reveals a relationship between them via asymmetric bending and stretching modes that arise from Zr atom displacements due to polyhedral [ZrO6] distortion. Furthermore, the results provided an insight into the PL emissions of the as-synthesized CaZrO3 and led to the conclusion that the presence of electronically excited states is strongly related to the structural order-disorder effects (polyhedral distortion) at short range for both [ZrO6] and [CaO8] clusters

An Ab Initio Analysis of Structural and Electronic Properties of Cubic SrSnO3

This article reports a theoretical study on structural and electronic properties of the cubic strontium stannate (SrSnO3) using periodic quantum-mechanics calculations within the Density Functional Theory method combined with B3LYP exchange-correlation functional, as implemented in the CRYSTAL14 code. The results were analyzed using the energy level diagram, atomic orbital distributions, and electron density maps. The structural analysis confirmed the SrSnO3 cubic symmetry, and the electronic properties were associated with [SrO12] and [SnO6] clusters with distinct bonding character. Furthermore, our structural and electronic calculations are in good agreement with the available experimental data showing a mean percentage error close to 2.2% for the structural parameter and paving the avenue towards the complete understanding of the overall properties of perovskite materials. DOI: http://dx.doi.org/10.17807/orbital.v13i3.160

First principle investigation of the exposed surfaces and morphology of β-ZnMoO4

Crystal shape is a critical determinant of the physical and chemical properties of crystalline materials; hence, it is the challenge of controlling the crystal morphology in a wide range of scientific and technological applications. The morphology is related to the geometry of their exposed surfaces, which can be described by their surface energies. The surface properties of β-ZnMoO4 have not yet been well explored, either experimentally or theoretically. Thus, the first-principle calculation at the density functional theory level was carried out for different low-index surfaces of β-ZnMoO4, specifically (001), (010), (110), (011), (101), and (111), and the surface energy values (Esurf) were reported. The surface stability was found to be controlled by the undercoordinated [MoOn…yVxO] and [ZnOn…yVxO] (n = 4 and 5; y = 1 and 2) clusters, i.e., their local coordination of Mo and Zn cations at the exposed surfaces, respectively, with the (111) surface being the most stable. A complete map of investigated β-ZnMoO4 morphologies was obtained using the Wulff construction and changing the values of the calculated energy surfaces. The final geometries from this map were compared with field emission-scanning electron microscopy images showing excellent agreement, prevising rectangular and hexagonal plates. Our findings will promote the use of facet engineering and might provide strategies to produce β-ZnMoO4-based materials for achieving morphology-dependent technological applications

Experimental and theoretical study of the energetic, morphological, and photoluminescence properties of CaZrO3:Eu3+

In this study, we present a combined experimental and theoretical study of the geometry, electronic structure, morphology, and photoluminescence properties of CaZrO3:Eu3+ materials. The polymeric precursor method was employed to synthesize CaZrO3:Eu3+ crystals, while density functional theory calculations were performed to determine the geometrical and electronic properties of CaZrO3:Eu3+ in its ground and excited electronic states (singlet and triplet). The results were combined with X-ray diffraction (XRD) measurements to elucidate the local structural changes induced by the introduction of Eu3+ in the crystal lattice. This process results in the formation of intermediate levels in the band-gap (Egap) region, narrowing its width. The PL emissions were rationalized by characterizing the electronic structure of the excited singlet and triplet electronic states, which provided deep insight into the main structural and electronic fingerprints associated with [CaO8], [EuO8], and [ZrO6] clusters. In addition, the Wulff construction, obtained from the first-principles calculations, was used to clarify the experimental morphologies. These results extend our fundamental understanding of the atomic processes that underpin the Eu doping of CaZrO3

Computational Chemistry Meets Experiments for Explaining the Geometry, Electronic Structure, and Optical Properties of Ca10V6O25

In this paper, we present a combined experimental and theoretical study to disclose, for the first time, the structural, electronic, and optical properties of Ca10V6O25 crystals. The microwave-assisted hydrothermal (MAH) method has been employed to synthesize these crystals with different morphologies, within a short reaction time at 120 °C. First-principle quantum mechanical calculations have been performed at the density functional theory level to obtain the geometry and electronic properties of Ca10V6O25 crystal in the fundamental and excited electronic states (singlet and triplet). These results, combined with the measurements of X-ray diffraction (XRD) and Rietveld refinements, confirm that the building blocks lattice of the Ca10V6O25 crystals consist of three types of distorted 6-fold coordination [CaO6] clusters: octahedral, prism and pentagonal pyramidal, and distorted tetrahedral [VO4] clusters. Theoretical and experimental results on the structure and vibrational frequencies are in agreement. Thus, it was possible to assign the Raman modes for the Ca10V6O25 superstructure, which will allow us to show the structure of the unit cell of the material, as well as the coordination of the Ca and V atoms. This also allowed us to understand the charge transfer process that happens in the singlet state (s) and the excited states, singlet (s*) and triplet (t*), generating the photoluminescence emissions of the Ca10V6O25 crystals

Radiation Macular Edema after Ru-106 Plaque Brachytherapy for Choroidal Melanoma Resolved by an Intravitreal Dexamethasone 0.7-mg Implant

Purpose: To report the effective treatment of radiation macular edema following ruthenium-106 plaque brachytherapy for a choroidal melanoma with a dexamethasone 0.7-mg (Ozurdex®) intravitreal implant. Methods: An interventional case report with optical coherence tomography (OCT) scans. Results: A 65-year-old Caucasian woman was suffering from radiation macular edema following ruthenium-106 plaque brachytherapy for a choroidal melanoma on her left eye. She had undergone one intravitreal injection of 0.5 mg bevacizumab (Avastin®, Genentech/Roche) in the following months without functional or anatomical improvement. Seven months after the development of radiation macular edema, she received a single intravitreal injection of dexamethasone 0.7 mg (Ozurdex). Four weeks following the injection, her best-corrected visual acuity improved from 0.3 to 0.5. Radiation macular edema resolved with a reduction of central retinal thickness from 498 µm before Ozurdex injection to 224 µm after Ozurdex injection, as measured by OCT scan. Conclusion: Dexamethasone 0.7 mg (Ozurdex) has proven to be an effective treatment option in retinal vein occlusion and noninfectious uveitis. It can also be considered as off-label treatment in radiation macular edema following ruthenium-106 plaque brachytherapy for a choroidal melanoma

Persistent collapse of biomass in Amazonian forest edges following deforestation leads to unaccounted carbon losses

Deforestation is the primary driver of carbon losses in tropical forests, but it does not operate alone. Forest fragmentation, a resulting feature of the deforestation process, promotes indirect carbon losses induced by edge effect. This process is not implicitly considered by policies for reducing carbon emissions in the tropics. Here, we used a remote sensing approach to estimate carbon losses driven by edge effect in Amazonia over the 2001 to 2015 period. We found that carbon losses associated with edge effect (947 Tg C) corresponded to one-third of losses from deforestation (2592 Tg C). Despite a notable negative trend of 7 Tg C year(-1) in carbon losses from deforestation, the carbon losses from edge effect remained unchanged, with an average of 63 +/- 8 Tg C year(-1). Carbon losses caused by edge effect is thus an additional unquantified flux that can counteract carbon emissions avoided by reducing deforestation, compromising the Paris Agreement's bold targets.Peer reviewe