The Sport League's Dilemma: Competitive Balance versus Incentives to Win

We analyze a dynamic model of strategic interaction between a professional sport league that organizes a tournament, the teams competing to win it, and the broadcasters paying for the rights to televise it.Teams and broadcasters maximize expected profits, while the league's objective may be either to maximize the demand for the sport or to maximize the teams'joint profits.Demand depends positively on symmetry among teams (competitive balance) and how aggressively teams try to win (incentives to win).Revenue sharing increases competitive balance but decreases incentives to win.Under demand maximization, a performance-based reward scheme (used by European sport leagues) may be optimal. Under joint profit maximization, full revenue sharing (used by many US leagues) is always optimal.These results reflect institutional differences among European and American sports leagues.sport;competition;incentives;broadcasting industry;revenue sharing

Skill, Strategy and Passion: An Empirical Analysis of Soccer

zero sum games;motivation;rationality;natural experiments;sports;soccer

Tin Oxides: New anodes for Li-Ion cells

La reacción entre el litio y óxidos o aleaciones de estaño es reversible cuando se realiza por métodos electroquímicos y a bajos potenciales con respecto al electrodo de litio. Esta propiedad permite el uso de estos materiales como electrodos negativos en el diseño y construcción de baterías tipo ion-litio. En el caso de óxidos de estaño la reacción de inserción de litio en la matriz conduce a la formación de aleaciones Li-Sn. La presencia de agregados grandes de átomos de estaño, formados durante la inserción de litio, origina la fragmentación y el desmoronamiento del material anódico. Este efecto provoca la pérdida del contacto eléctrico entre partículas, con el consiguiente deterioro de la batería. La optimización del rendimiento electroquímico de estos materiales se puede lograr mediante el control del crecimiento y tamaño de los agregados de estaño.The electrochemical reaction between Li and tin-based compounds, is reversible and takes place at low potentials measured against the Li electrode. This feature allows the use of these materials as negative electrodes in the manufacturing of Li-ion batteries. The lithium insertion in the tin oxides leads to the formation of Li-Sn alloys. The presence of large tin clusters, formed during the reaction, causes the cracking and crumblimg of the anodic material and the electronic contact between the particles is lost. The electrochemical performance of these materials can be optimized by controlling the growing and size of tin aggregate

Folding of the nascent polypeptide chain of a histidine phosphocarrier protein in vitro

The phosphotransferase system (PTS), a metabolic pathway formed by five proteins, modulates the use of sugars in bacteria. The second protein in the chain is the histidine phosphocarrier, HPr, with the binding site at His15. The HPr kinase/phosphorylase (HPrK/P), involved in the bacterial use of carbon sources, phosphorylates HPr at Ser46, and it binds at its binding site. The regulator of sigma D protein (Rsd) also binds to HPr at His15. We have designed fragments of HPr, growing from its N-terminus and containing the His15. In this work, we obtained three fragments, HPr38, HPr58 and HPr70, comprising the first thirty-eight, fifty-eight and seventy residues of HPr, respectively. All fragments were mainly disordered, with evidence of a weak native-like, helical population around the binding site, as shown by fluorescence, far-ultraviolet circular dichroism, size exclusion chromatography and nuclear magnetic resonance. Although HPr38, HPr58 and HPr70 were disordered, they could bind to: (i) the N-terminal domain of first protein of the PTS, EIN; (ii) Rsd; and, (iii) HPrK/P, as shown by fluorescence and biolayer interferometry (BLI). The association constants for each protein to any of the fragments were in the low micromolar range, within the same range than those measured in the binding of HPr to each protein. Then, although acquisition of stable, native-like secondary and tertiary structures occurred at the last residues of the polypeptide, the ability to bind protein partners happened much earlier in the growing chain. Binding was related to the presence of the native-like structure around His15

Preferencias de hábitat, densidad y diversidad de las comunidades de aves en Tenerife (Islas Canarias)

Bird distribution and abundance are described and analyzed in Teneriffe (Canary Islands). Inter–habitat differences in density, diversity and species richness are shown in table 1. Figure 2 shows the main determinants of bird species richness in Teneriffe, and tables 2 and 3 and figure 3 show the species–specific patterns of spatial variation abundance (more detailed for Anthus berthelotii, Fringilla coelebs canariensis, Fringilla teydea, Parus caeruleus teneriffae, Phylloscopus canariensis, Regulus teneriffae, Serinus canarius and Turdus merula cabrerae). Deeply transformed environments due to human impact (urban habitats, agricultural mosaics, banana plantations) have high bird densities and species richness, even higher than those measured in native, unmodified habitats such as laurel forests or mature pinewoods. Urban environments in Teneriffe are very permeable to native bird fauna, as they have been occupied by many widespread endemic species/subspecies. Many of the endemic, well defined species or subspecies of island birds have high population densities within native, untransformed habitats. Density compensation and niche expansion is not a common phenomenon in the avifauna of Teneriffe. Nevertheless, all species/subspecies broadening the inter–habitat or altitudinal distribution are endemic of the Canary Islands.Mediante el empleo de transectos lineales, se describen las preferencias de hábitat, la distribución altitudinal y la abundancia de la avifauna reproductora de Tenerife (Islas Canarias). Los hábitats profundamente transformados debido a la acción humana (e.g., áreas urbanas, mosaicos agrícolas, plantaciones de plátanos) tienen elevadas densidades y riquezas de especies, que llegan a ser tan altas o mayores que las observadas en medios autóctonos no transformados como laurisilvas y pinares maduros. Muchas especies/subespecies taxonómicamente bien diferenciadas de las poblaciones continentales están distribuidas mayoritaria o exclusivamente en hábitats autóctonos poco degradados. Las hipótesis de la compensación de densidades y la expansión de nicho en poblaciones insulares no parecen cumplirse de modo generalizado en Tenerife. No obstante, todas las especies o subespecies que muestran una mayor amplitud de distribución en Tenerife son endémicas del archipiélago canario

Sesgos en la obtención de estimas de densidad obtenidas por medio de transectos lineales en ambientes estepáricos de las Islas Canarias

We studied bias in density estimations derived from strip transects in dry open–country in the Canary Islands. We also present some critical remarks on García–del–Rey’s (2005) paper regarding strip transects and the validity of comparisons based on population densities of birds in scrublands on Tenerife island using two different methods: territory mapping and strip transect sampling. Although strip transects with census belts of 25 m do not account for detectability, this method only slightly undervalues true density estimates, and allowed to detect more than 85% of birds present in poorly vegetated environments in the Canary Islands. Previously published works on distribution and abundance of terrestrial birds in the Canary Islands using the strip transect sampling with belts of 25 m on both sides of the observer, thus provide reliable information that only slightly underestimates true densities. Key words: Birds, Canary Islands, Census methods, Strip transects, Open–country environments, Population density, Territory mapping.We studied bias in density estimations derived from strip transects in dry open–country in the Canary Islands. We also present some critical remarks on García–del–Rey’s (2005) paper regarding strip transects and the validity of comparisons based on population densities of birds in scrublands on Tenerife island using two different methods: territory mapping and strip transect sampling. Although strip transects with census belts of 25 m do not account for detectability, this method only slightly undervalues true density estimates, and allowed to detect more than 85% of birds present in poorly vegetated environments in the Canary Islands. Previously published works on distribution and abundance of terrestrial birds in the Canary Islands using the strip transect sampling with belts of 25 m on both sides of the observer, thus provide reliable information that only slightly underestimates true densities. Key words: Birds, Canary Islands, Census methods, Strip transects, Open–country environments, Population density, Territory mapping.Se estudian los sesgos derivados del empleo del método del taxiado (transectos lineales con bandas de 25 m a cada lado del observador) para obtener densidades en ambientes estepáricos de las Islas Canarias. También se presentan algunos comentarios críticos al trabajo de García–del–Rey (2005) que compara estimas de densidad obtenidas en Tenerife utilizando dos métodos diferentes: mapeo de territorios y transecto lineal. Aunque el método del taxiado estima densidades relativas no corregidas por la detectabilidad de las especies, este método proporciona valores de densidad muy parecidos a los reales, ya que permite detectar en ambientes con poca cobertura vegetal a más del 85% de los individuos dentro de bandas de 25 m a cada lado del observador. Por tanto, los trabajos previamente publicados sobre densidades de aves en Canarias proporcionan estimas fiables sólo ligeramente infravaloradas. Palabras clave: Aves, Islas Canarias, Métodos de censo, Transecto lineal, Ambientes estepáricos, Densidad de población, Mapeo de territorios

Nuevos materiales compuestos Si/carbono grafitizado como electrodos negativos de alta energía para baterías de litio-ión

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC