Information Transmission around Block Trades on the Spanish Stock Market.

This study investigates the informational effects of large transactions, or Block Trades (BT), in the Spanish Stock Exchange (SSE). In the open market period, this topic was not facilitated in the SSE as it was in other markets until 1998. The SSE thus provides a special environment for analysing the information transmission of these specific transactions. It is assumed that information can be better reflected by changes in true asset value, proxied by the midpoint of bid-ask best quotes. Therefore, we will look at changing true asset value orders instead of trades. Three different effects are studied around BTs: price, liquidity and information transmission. To capture them, three different endogenous variables are considered: true asset returns, relative spreads and adverse selection spread component. With this approach, no clear effects of BTs are found. The main result of the study is that there seems to be an increase in information asymmetries when one looks at the adverse selection spread component in some of the different subsample classifications (buyer, seller and sweeping BT), but there is no significant permanent effect on returns. This result could be related to insiders trading in the market. In sharp contrast with adverse selection evidence, a temporary decrease in bid/ask spread around BTs is also observed. These changes reflect temporary liquidity effects related to other spread components (order processing costs and inventory costs).

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Overconstrained dynamics in galaxy redshift surveys

The least-action principle (LAP) method is used on four galaxy redshift surveys to measure the density parameter Omega_m and the matter and galaxy-galaxy power spectra. The datasets are PSCz, ORS, Mark III and SFI. The LAP method is applied on the surveys simultaneously, resulting in an overconstrained dynamical system that describes the cosmic overdensities and velocity flows. The system is solved by relaxing the constraint that each survey imposes upon the cosmic fields. A least-squares optimization of the errors that arise in the process yields the cosmic fields and the value of Omega_m that is the best fit to the ensemble of datasets. The analysis has been carried out with a high-resolution Gaussian smoothing of 500 km/s and over a spherical selected volume of radius 9,000 km/s. We have assigned a weight to each survey, depending on their density of sampling, and this parameter determines their relative influence in limiting the domain of the overall solution. The influence of each survey on the final value of Omega_m, the cosmographical features of the cosmic fields and the power spectra largely depends on the distribution function of the errors in the relaxation of the constraints. We find that PSCz and Mark III are closer to the final solution than ORS and SFI. The likelihood analysis yields Omega_m= 0.37\pm 0.01 to 1sigma level. PSCz and SFI are the closest to this value, whereas ORS and Mark III predict a somewhat lower Omega_m. The model of bias employed is a scale-dependent one, and we retain up to 42 bias coefficients b_{rl} in the spherical harmonics formalism. The predicted power spectra are estimated in the range of wavenumbers 0.02-0.49h Mpc^{-1}, and we compare these results with measurements recently reported in the literature.Comment: 10 pages, no figure

On the tailoring of CAST-32A certification guidance to real COTS multicore architectures

The use of Commercial Off-The-Shelf (COTS) multicores in real-time industry is on the rise due to multicores' potential performance increase and energy reduction. Yet, the unpredictable impact on timing of contention in shared hardware resources challenges certification. Furthermore, most safety certification standards target single-core architectures and do not provide explicit guidance for multicore processors. Recently, however, CAST-32A has been presented providing guidance for software planning, development and verification in multicores. In this paper, from a theoretical level, we provide a detailed review of CAST-32A objectives and the difficulty of reaching them under current COTS multicore design trends; at experimental level, we assess the difficulties of the application of CAST-32A to a real multicore processor, the NXP P4080.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under grant TIN2015-65316-P and the HiPEAC Network of Excellence. Jaume Abella has been partially supported by the MINECO under Ramon y Cajal grant RYC-2013-14717.Peer ReviewedPostprint (author's final draft

Entanglement, fractional magnetization and long-range interactions

Based on the theory of Matrix Product States, we give precise statements and complete analytical proofs of the following claim: a large fractionalization in the magnetization or the need of long-range interactions imply large entanglement in the state of a quantum spin chain.Comment: 11 pages, 1 figur

Folklore/Cinema: Popular Film as Vernacular Culture

Interest in the conjunctions of film and folklore is stronger and more diverse than ever. Documentaries on folk life and expression remain a vital genre, but scholars such as Sharon Sherman and Mikel Koven also are exploring how folklore elements appear in, and merge with, popular cinema. They look at how movies, a popular culture medium, can as well be both a medium and type of folklore, playing cultural roles and conveying meanings customarily found in other folkloric forms. They thus use the methodology of folklore studies to analyze films made for commercial distribution. The contributors to this book look at film and folklore convergences, showing how cinema conveys vernacular culture in traditional and popular venues. Folklore/Cinema will be of interest to scholars from many fields---folklore, film studies, popular culture, American studies, history, anthropology, and literature among them---and will help introduce students in various courses to intersections of film and culture.https://digitalcommons.usu.edu/usupress_pubs/1033/thumbnail.jp

Fractures of allografts used in limb preserving operations

One hundred and thirty-seven allografts used since 1986 in limb preserving operations for malignant bone tumours were reviewed. The follow up was longer than two years. There were fourteen fractures (10.2%) in twelve patients at a mean time of 22 months from the operation. Most of them were in the metaphyseal area and were related to perforations of the allograft made for stabilisation with plates, for tendon and ligament reattachment, or any other hole in the allograft. Fractures occurred always after the allograft-host junction was united. Healing was achieved in 7 cases by internal fixation with autologous bone grafting in a mean of 5 months. In cases of multiple fractures of the allograft, the graft was exchanged. We recommend using intramedullary fixation in order to reduce the incidence of allograft fracture, and the use of internal fixation, with intramedullary whenever possible, and autologous bone grafting to achieve consolidation of the fractures

Natural variation in snow depth and snow melt timing in the High Arctic have implications for soil and plant nutrient status and vegetation composition

Snow cover is a key component in Arctic ecosystems and will likely be affected by changes in winter precipitation. Increased snow depth and consequent later snowmelt leads to greater microbial mineralization in winter, improving soil and vegetation nutrient status. We studied areas with naturally differing snow depths and date of snowmelt in Adventdalen, Svalbard. Soil properties, plant leaf nutrient status, and species composition along with the normalized difference vegetation index (NDVI) were compared for three snowmelt regimes (Early, Mid, and Late). We showed that (1) Late regimes (snow beds) had wetter soils, higher pH, and leaves of Bistorta vivipara (L.) Delarbre and Salix polaris Wahlenb. had higher concentration of nutrients (nitrogen and δ15N). Little to no difference was found in soil nutrient concentrations between snowmelt regimes. (2) Late regimes had highest NDVI values, whereas those of Early and Mid regimes were similar. (3) Vegetation composition differed between Early and Late regimes, with Dryas octopetala L. and Luzula arcuata subsp. confusa (Lange) characterizing the former and Equisetum arvense L. and Eriophorum scheuchzeri Hoppe the latter. (4) Trends for plant nutrient contents were similar to those found in a nearby snow manipulation experiment. Snow distribution and time of snowmelt played an important role in determining regional environmental heterogeneity, patchiness in plant community distribution, their species composition, and plant phenology