9,624 research outputs found
The economic geography of football success: empirical evidence from european cities
Introduction. â 1. The geography of successful football teams: an analytical framework â 2. Empirical analysis â 2.1. Data, model estimation and results â 2.2. Cities and teams: some remarks about market size and teamsâ performance â 3. Conclusions â 4. Annex
The production process in basketball: Empirical evidence from Spanish league
The main objective of this paper is to provide an empirical assessment of the production process in a basketball team. We estimate a logit model in which the output produced by a team is the game outcome (win or loss) and the inputs are those play characteristics that impact on that outcome. From the results obtained it is clear that, on average, there is a substantial difference between the impact of each play characteristic on a basketball teamâs winning probability and that probability varies as the quality/quantity of the inputs used changes, albeit not proportionally.sports economics, team sport, professional basketball, productive process, logit model
Elastic, dielectric and electromechanical properties of (Bi0.5Na0.5)TiO3-BaTiO3 piezoceramics at the morphotropic phase boundary region
A systematic study of the functional properties of the (1-x)(Bi0.5Na0.5)TiO3âxBaTiO3 (BNT-xBT) piezoceramic system for 0.05 = x = 0.07 is performed. The samples are obtained through the conventional solid-state route. The expected microstructure for these compounds, with no significant dependence on the composition, is verified by field-emission scanning electron microscopy. The morphotropic phase boundary (MPB) is detected for x = 0.06â0.07 by means of the Rietveld analysis of X-ray diffraction data. The dielectric spectra show a frequency-independent, completely diffuse phase transition with a composition-dependent diffusivity coefficient. The depolarization temperature is effectively evaluated from pyroelectric measurements, the value being strongly dependent on the composition. A significant contribution of the extrinsic effect to elastic, dielectric and electromechanical properties is revealed for MPB BNT-xBT. The Bi3+ substitution by Ba2+ leads to the formation of A-site vacancies, which give rise to the enhancement of domain wall motion, as occurs in other perovskite-type piezoelectrics. Good functional properties are achieved for x = 0.07 (d33 = 180 pC/N), which are similar or even better than those obtained by complex synthesis routes. This system exhibits a remarkable stability in the permittivity that has hitherto not been reported. This fact may open the way for BNT-BT compositions to be used in specific applications in which lead-free piezoceramics have previously been employed with little success, e.g. in high power devices.Postprint (author's final draft
Are beryllium abundances anomalous in stars with giant planets?
In this paper we present beryllium (Be) abundances in a large sample of 41
extra-solar planet host stars, and for 29 stars without any known
planetary-mass companion, spanning a large range of effective temperatures. The
Be abundances were derived through spectral synthesis done in standard Local
Thermodynamic Equilibrium, using spectra obtained with various instruments. The
results seem to confirm that overall, planet-host stars have ``normal'' Be
abundances, although a small, but not significant, difference might be present.
This result is discussed, and we show that this difference is probably not due
to any stellar ``pollution'' events. In other words, our results support the
idea that the high-metal content of planet-host stars has, overall, a
``primordial'' origin. However, we also find a small subset of planet-host
late-F and early-G dwarfs that might have higher than average Be abundances.
The reason for the offset is not clear, and might be related either to the
engulfment of planetary material, to galactic chemical evolution effects, or to
stellar-mass differences for stars of similar temperature.Comment: 15 pages, 9 figures, accepted for publication in Astronomy &
Astrophysic
Requirement of a Plasmid-Encoded Catalase for Survival of \u3cem\u3eRhizobium etli\u3c/em\u3e CFN42 in a Polyphenol-Rich Environment
Nitrogen-ïŹxing bacteria collectively called rhizobia are adapted to live in polyphenol-rich environments. The mechanisms that allow these bacteria to overcome toxic concentrations of plant polyphenols have not been clearly elucidated. We used a crude extract of polyphenols released from the seed coat of the black bean to simulate a polyphenol-rich environment and analyze the response of the bean-nodulating strain Rhizobium etli CFN42. Our results showed that the viability of the wild type as well as that of derivative strains cured of plasmids p42a, p42b, p42c, and p42d or lacking 200 kb of plasmid p42e was not affected in this environment. In contrast, survival of the mutant lacking plasmid p42f was severely diminished. Complementation analysis revealed that the katG gene located on this plasmid, encoding the only catalase present in this bacterium, restored full resistance to testa polyphenols. Our results indicate that oxidation of polyphenols due to interaction with bacterial cells results in the production of a high quantity of H2O2, whose removal by the katG-encoded catalase plays a key role for cell survival in a polyphenol-rich environment
Probabilistic prediction of raw and BMA calibrated AEMET-SREPS: the 24 of January 2009 extreme wind event in Catalunya
At 00:00 UTC of 24 January 2009 (24Jan09) an explosive cyclogenesis placed at
the Gulf of Vizcaya, reached its maximum intensity with observed surface
pressures below 970 hPa on its center. During its path through the south of
France there were strong westerly and north-westerly winds over Iberian
Peninsula (above 150 km/h). These extreme winds leaved 8 casualties in
Catalunya, the north-east region of Spain.
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The aim of this work is validating the skill of the Spanish Meteorological
Agency (AEMET) Short Range Ensemble Prediction System (SREPS) in forecasting
this event. Two probabilistic forecasts of wind are compared, a
non-calibrated (or raw) and a calibrated one using the Bayesian Model
Averaging (BMA).
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AEMET runs a daily experimental SREPS twice a day (00:00 and
12:00 UTC). This system consists on 25 members that are constructed by
integrating five different Limited Area Models (LAMs) at 0.25 degrees of
horizontal resolution. Each model uses five different initial and boundary
conditions from five Global Models (GMs). Thus it is obtained a probabilistic
forecast that takes into account initial, contour and model uncertainties.
<br><br>
BMA is a statistical tool for combining predictive Probability Distribution
Functions (PDFs) from different sources. BMA predictive PDF is a weighted
average of PDFs centered on the individual bias-corrected forecasts. Each
weight is a measure of the corresponding forecast skill. Here BMA is applied
to calibrate probabilistic forecasts of wind speed.
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In this work two time forecast ranges (H+60 and H+36) of 10-m wind
speed over Catalonia are verified subjectively at 12:00 UTC of 24Jan09 valid
time. We focus on the location and intensity of 10-m wind speed maximum
values. Observations at 29 automatic ground stations of AEMET are used for
the verification.
<br><br>
On one hand results indicate that raw AEMET-SREPS is able to forecast 60 h
ahead mean winds higher than 36 and 54 km/h and that it correctly
locates them in three different areas. On the other hand, predicted
probability loses its skill after BMA calibration of the ensemble. This is
due to the fact that BMA bias correction underestimates the intensity of
wind
Identifying past social-ecological thresholds to understand long-term temporal dynamics in Spain
A thorough understanding of long-term temporal social-ecological dynamics at the national scale helps to explain the current condition of a countryâs ecosystems and to support environmental policies to tackle future sustainability challenges. We aimed to develop a methodological approach to understand past long-term (1960-2010) social-ecological dynamics in Spain. First, we developed a methodical framework that allowed us to explore complex social-ecological dynamics among biodiversity, ecosystem services, human well-being, drivers of change, and institutional responses. Second, we compiled 21 long-term, national-scale indicators and analyzed their temporal relationships through a redundancy analysis. Third, we used a Bayesian change point analysis to detect evidence of past social-ecological thresholds and historical time periods. Our results revealed that Spain has passed through four socialecological thresholds that define five different time periods of nature and society relationships. Finally, we discussed how the proposed methodological approach helps to reinterpret national-level ecosystem indicators through a new conceptual lens to develop a more systems-based way of understanding long-term social-ecological patterns and dynamicsThis work was supported by the Biodiversity Foundation (http://www.fundacion-biodiversidad.es/) of the Spanish Ministry of Agriculture, Food and Environment. Partial
financial support was also provided by the Ministry of Economy and Competitiveness of Spain (project CGL2014-53782-P: ECOGRADIENTES). The Spanish National Institute for
Agriculture and Food Research and Technology (INIA) funded Marina GarcĂa-Llorente as part of the European Social Fund. Blanca GonzĂĄlez GarcĂa-Mon participated in this article as a âla
Caixaâ Banking Foundation scholar. The funders had no role in the study design, data collection and analysis, preparation of the report, or the decision to submit the study for publicatio
Nitrogen abundances in Planet-harbouring stars
We present a detailed spectroscopic analysis of nitrogen abundances in 91
solar-type stars, 66 with and 25 without known planetary mass companions. All
comparison sample stars and 28 planet hosts were analysed by spectral synthesis
of the near-UV NH band at 3360 \AA observed at high resolution with the
VLT/UVES,while the near-IR NI 7468 \AA was measured in 31 objects. These two
abundance indicators are in good agreement. We found that nitrogen abundance
scales with that of iron in the metallicity range -0.6 <[Fe/H]< +0.4 with the
slope 1.08 \pm 0.05. Our results show that the bulk of nitrogen production at
high metallicities was coupled with iron. We found that the nitrogen abundance
distribution in stars with exoplanets is the high [Fe/H] extension of the curve
traced by the comparison sample of stars with no known planets. A comparison of
our nitrogen abundances with those available in the literature shows a good
agreement.Comment: 15 pages, 7 figures, Accepted for publication in A&
Climatic vulnerabilities and ecological preferences of soil invertebrates across biomes.
Unlike plants and vertebrates, the ecological preferences, and potential vulnerabilities of soil invertebrates to environmental change, remain poorly understood in terrestrial ecosystems globally. We conducted a cross-biome survey including 83 locations across six continents to advance our understanding of the ecological preferences and vulnerabilities of the diversity of dominant and functionally important soil invertebrate taxa, including nematodes, arachnids and rotifers. The diversity of invertebrates was analyzed through amplicon sequencing. Vegetation and climate drove the diversity and dominant taxa of soil invertebrates. Our results suggest that declines in forest cover and plant diversity, and reductions in plant production associated with increases in aridity, can result in reductions of the diversity of soil invertebrates in a drier and more managed world. We further developed global atlases of the diversity of these important soil invertebrates, which were cross-validated using an independent database. Our study advances the current knowledge of the ecological preferences and vulnerabilities of the diversity and presence of functionally important soil invertebrates in soils from across the globe. This information is fundamental for improving and prioritizing conservation efforts of soil genetic resources and management policies
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