Un estudio empírico de los honorarios del auditor

ResumenLa reciente normativa que requiere desde 2002 la revelación de los honorarios facturados por las firmas de auditoría a sus clientes, indicando los correspondientes a cada servicio prestado, nos ha brindado la oportunidad de abordar un análisis empírico del nivel y composición de los honorarios para el caso español. La cuestión es relevante porque se aportan nuevas evidencias acerca del mercado de servicios profesionales y del grado de competitividad existente. Así, analizamos sus factores explicativos y la posible determinación conjunta de los honorarios por servicios de auditoría y consultoría, y documentamos cómo el conocimiento adquirido en unas actividades es aprovechado en otras (knowledge spillovers), sin que sea posible conocer en qué modo las economías de alcance obtenidas se distribuyen entre auditor (en forma de mayores beneficios) y cliente (en forma de menores precios), lo que dependerá del grado de competencia de este mercado. Adicionalmente, no hemos obtenido evidencia de precios introductorios iniciales de choque (lowballing). Finalmente, los honorarios facturados por servicios de consultoría no son diferentes entre las grandes firmas, pero los devengados por trabajos de auditoría son significativamente menores en las pequeñas, no existiendo en este caso estrategias de precios distintas entre las cuatro grandes. Nuestros resultados son robustos y se mantienen con el empleo de diferentes modelos y especificaciones alternativas.AbstractThe new regulation requiring the disclosure of audit fees split by type of services since 2002, has allowed us to undertake an empirical analysis of the level and composition of the fees in the Spanish market. Our analysis provides new relevant evidence on the market for professional services and the existing level of competition. We analyze their determinants as well as the possible joint assessment of the fees for audit and consulting services. Our results show that knowledge creation in certain activities is applied to create value via the provision of other services (knowledge spillovers). However, it does not seem possible to characterize the ways in which economies of scope are shared between the auditor (in terms of higher revenues) and the client (in terms of lower prices), as this appears to depend on the extent of competition in the market. Furthermore, we could not obtain evidence documenting the existence of lowballing. Finally, we found that the fees charged for consulting services do not differ significantly across big audit firms (who seem to have similar price strategies), but audit fees are significantly lower in the case of small firms. Our results are robust in the presence of different models and alternative specification

Investigation of acceptor levels and hole scattering mechanisms in p-gallium selenide by means of transport measurements under pressure

The effect of pressure on acceptor levels and hole scattering mechanisms in p-GaSe is investigated through Hall effect and resistivity measurements under quasi-hydrostatic conditions up to 4 GPa. The pressure dependence of the hole concentration is interpreted through a carrier statistics equation with a single (nitrogen) or double (tin) acceptor whose ionization energies decrease under pressure due to the dielectric constant increase. The pressure effect on the hole mobility is also accounted for by considering the pressure dependencies of both the phonon frequencies and the hole-phonon coupling constants involved in the scattering rates.Comment: 13 pages, Latex, 4 ps figures. to appear in High Pressure Research 69 (1997

DISEÑO DE UNA COLUMNA DE ABSORCIÓN EMPACADA CONSIDERANDO CUATRO TIPOS DE EMPAQUE Y APLICANDO MATLAB

In the present work, a packed bed absorption column is designed to recover certain amounts of ethanol contained in a gaseous stream. Four packing types (50-mm metal Hiflow® rings, 50-mm ceramic Pall® rings, 50-mm metal Top Pak® rings and 25-mm metal VSP® rings) are considered in order to select the most appropriate one in terms of column dimensions, pressure drop and mass-transfer results. Several design parameters were determined including column diameter (D), packing height (Z), overall mass-transfer coefficient (Km) and gas pressure drop (P/Z), as well as the overall number of gas-phase transfer units (NtOG), overall height of a gas-phase transfer unit (HtOG) and the effective surface area of packing (ah). The most adequate packing to use for this absorption system constitutes the 25-mm metal VSP® rings, since it provided the greatest values of Km (0.325 kmol/m3.s), and ah (169.57 m-1), as well as the lowest values of both Z (0.6 m) and HtOG (0.145 m), meaning that it will supply the higher mass-transfer conditions with the lowest column dimensions. The influence of both gas mixture (QG) and solvent (mL) feed flowrates on D, Z, Km, P/Z, NtOG and HtOG was also evaluated for the four packing considered. The design methodology was solved using computing software MATLAB® version 7.8.0.347 (R2009a) (Math Works, 2009), and also Microsoft Excel®.DEn el presente trabajo se diseña una columna de absorción empacada para recuperar ciertas cantidades de etanol contenido en una corriente gaseosa. Se consideran 4 tipos de empaques (anillos Hiflow® metálicos de 50 mm, anillos Pall® cerámicos de 50 mm, anillos Top Pak® metálicos de 50 mm, y anillos VSP® metálicos de 25 mm) con el fin de seleccionar el más apropiado en términos de dimensiones de la columna, caída de presión y resultados de transferencia de masa. Se determinaron varios parámetros de diseño incluyendo diámetro de la columna (D), altura del empaque (Z), coeficiente global de transferencia de masa (Km) y caída de presión gaseosa (P/Z), así como también el número total de unidades de transferencia den fase gaseosa (NtOG), altura total de unidades de transferencia en fase gaseosa (HtOG) y el área superficial efectiva del empaque (ah). El empaque más adecuado de usar en este sistema de absorción constituye los anillos VSP® metálicos de 25 mm, ya que suministra los mayores valores de Km (0.325 kmol/m3.s), y ah (169.57 m-1), así como también los menores valores de tanto Z (0.6 m) y HtOG (0.145 m), significando que suministrará las condiciones más altas de transferencia de masa con las menores dimensiones dela columna. La influencia de los caudales de alimentación de tanto la mezcla gaseosa (QG) y el solvente (mL) sobre D, Z, Km, DP/Z, NtOG y HtOG fue también evaluada para los cuatro tipos de empaques considerados. La metodología de diseño fue resuelta empleando el software MATLAB® versión 7.8.0.347 (R2009a) (Math Works, 2009), y también Microsoft Excel®

DISEÑO DE UNA COLUMNA DE ABSORCIÓN EMPACADA CONSIDERANDO CUATRO TIPOS DE EMPAQUE Y APLICANDO MATLAB

In the present work, a packed bed absorption column is designed to recover certain amounts of ethanol contained in a gaseous stream. Four packing types (50-mm metal Hiflow® rings, 50-mm ceramic Pall® rings, 50-mm metal Top Pak® rings and 25-mm metal VSP® rings) are considered in order to select the most appropriate one in terms of column dimensions, pressure drop and mass-transfer results. Several design parameters were determined including column diameter (D), packing height (Z), overall mass-transfer coefficient (Km) and gas pressure drop (P/Z), as well as the overall number of gas-phase transfer units (NtOG), overall height of a gas-phase transfer unit (HtOG) and the effective surface area of packing (ah). The most adequate packing to use for this absorption system constitutes the 25-mm metal VSP® rings, since it provided the greatest values of Km (0.325 kmol/m3.s), and ah (169.57 m-1), as well as the lowest values of both Z (0.6 m) and HtOG (0.145 m), meaning that it will supply the higher mass-transfer conditions with the lowest column dimensions. The influence of both gas mixture (QG) and solvent (mL) feed flowrates on D, Z, Km, P/Z, NtOG and HtOG was also evaluated for the four packing considered. The design methodology was solved using computing software MATLAB® version 7.8.0.347 (R2009a) (Math Works, 2009), and also Microsoft Excel®.DEn el presente trabajo se diseña una columna de absorción empacada para recuperar ciertas cantidades de etanol contenido en una corriente gaseosa. Se consideran 4 tipos de empaques (anillos Hiflow® metálicos de 50 mm, anillos Pall® cerámicos de 50 mm, anillos Top Pak® metálicos de 50 mm, y anillos VSP® metálicos de 25 mm) con el fin de seleccionar el más apropiado en términos de dimensiones de la columna, caída de presión y resultados de transferencia de masa. Se determinaron varios parámetros de diseño incluyendo diámetro de la columna (D), altura del empaque (Z), coeficiente global de transferencia de masa (Km) y caída de presión gaseosa (P/Z), así como también el número total de unidades de transferencia den fase gaseosa (NtOG), altura total de unidades de transferencia en fase gaseosa (HtOG) y el área superficial efectiva del empaque (ah). El empaque más adecuado de usar en este sistema de absorción constituye los anillos VSP® metálicos de 25 mm, ya que suministra los mayores valores de Km (0.325 kmol/m3.s), y ah (169.57 m-1), así como también los menores valores de tanto Z (0.6 m) y HtOG (0.145 m), significando que suministrará las condiciones más altas de transferencia de masa con las menores dimensiones dela columna. La influencia de los caudales de alimentación de tanto la mezcla gaseosa (QG) y el solvente (mL) sobre D, Z, Km, DP/Z, NtOG y HtOG fue también evaluada para los cuatro tipos de empaques considerados. La metodología de diseño fue resuelta empleando el software MATLAB® versión 7.8.0.347 (R2009a) (Math Works, 2009), y también Microsoft Excel®

Singular patterns of skull shape and brain size change in the domestication of South American camelids

Patterns of selection in South American camelids (Lamini) and their unique demographic history establish the llama and alpaca as remarkable cases of domestication among large herd animals. Skull shape is implicated in many changes reported between wild and domestic taxa. We apply 3D geometric morphometric methods to describe skull shape, form, and size, differences among the four species of Lamini. In so doing, we test if domesticated Lamini exhibit changes similar to those in other domesticated groups: not only in the skull, but also in brain and body size. In contrast to other domesticated artiodactyls, very little change has occurred in domestic alpacas and llamas compared to their wild counterparts. Nevertheless, their differences are statistically significant and include a flatter cranium, inclined palate and increased airorhynchy in the domestics. Selection pressures that contrast with those on other herd animals, as well as recent population bottlenecks, likely have influenced the morphological patterns we note in Lamini. High-resolution 3D morphospace allows skull size, shape, and form (shape + size), to discriminate all four species, with form providing the greatest separation. These results help differentiate morphologically the Lamini, which in nature are distinguished mainly by body size, and provide an additional tool to archaeologists for distinction of wild and domestic remains. Most of our shape analyses suggest a marginally closer relationship between the alpaca and vicuña, to the exclusion of the guanaco, supporting the genetic relationships for this group. The expected brain size change between wild and domestic populations is lower than previously thought, with a 15.4% reduction in llama, and 6.8% reduction in alpaca. This is the lowest reduction in brain size thus far reported among domesticated Artiodactyla

CCD Photometry of Trapezia Stars I

We present photometric CCD observations of stars in four stellar trapezia ADS 15184, ADS 4728, ADS 2843, and ADS 16795. This study is performed on images obtained at the Observatorio Astron\'omico Nacional at San Pedro M\'artir (OAN), Baja California, M\'exico. In this work we utilise aperture photometry to measure the $U$, $B$, $V$, $R$ and $I$ magnitudes of some of the stars in these dynamically unstable stellar clusters (trapezia). Using the $Q=(U-B)-0.72(B-V)$ parameter we obtained the spectral type of the studied stars as well as their distance to the Sun and their reddening. Slight differences between the $Q$-derived Spectral types and those listed in SIMBAD might be due to a different value, from $0.72$, for the slope of the reddening line on the two-colour diagram.Comment: 34 pages, 12 figures, 31 tables, accepted for publication in RevMexAA, vol. 60, num. 1, April 2

Rotura del ligamento deltoideo del tobillo: evaluación clínico-quirúrgica

No existe un criterio uniforme sobre la conduct a a seguir en el tratamient o de la rotur a del ligamento deltoideo del tobillo. Se ha n revisado 36 paciente s diagnosticados y tra - tado s quirúrgicament e de rotur a de dicho ligamento, la mayorí a de la s veces est a lesión iba acompañad a de fractur a del maleolo peroneo. Se ha valorado la etiología, el mecanismo lesional y los resultados siguiendo la clasificación de Cedell, considerándos e estos últimos como buenos en la práctic a totalidad de los casos. En cuatro de los paciente s (11%), se presentó como únic a secuela la limitación de la movilidad en los últimos grados de flexo-extensiónUniform criteria about the actions to be taken in the tearing of the ankle deltoid ligament d o no t exist. Thirt y si x patients diagnose d an d surgicall y treate d becaus e o f th e tearin g o f th e abov e mentione d ligamen t hav e bee n reviewed . Most o f th e times, this lesio n wa s accompanie d b y a fractur e o f th e peronea l maleolus. Etiology , injur y mechanism s an d results followin g Cedell's clasificatio n hav e bee n evaluate d an d th e results hav e bee n considere d goo d i n practicall y all cases. I n fou r patients, th e onl y secuel a wa s a limitatio n o f th e most extrem e grade s o f flexo-extension

Time-dependent ejection velocity model for the outflow of Hen 3--1475

We present 2D axisymmetric and 3D numerical simulations of the proto-planetary nebula Hen 3-1475, which is characterized by a remarkably highly collimated optical jet, formed by a string of shock-excited knots along the axis of the nebula. It has recently been suggested that the kinematical and morphological properties of the Hen 3-1475 jet could be the result of an ejection variability of the central source (Riera et al. 2003). The observations suggest a periodic variability of the ejection velocity superimposed on a smoothly increasing ejection velocity ramp. From our numerical simulations, we have obtained intensity maps (for different optical emission lines) and position-velocity diagrams, in order to make a direct comparison with the HST observations of this object. Our numerical study allows us to conclude that a model of a precessing jet with a time-dependent ejection velocity, which is propagating into an ISM previously perturbed by an AGB wind, can succesfully explain both the morphological and the kinematical characteristics of this proto-planetary nebula.Comment: Astronomy and Astrophysics (accepted) (8 figures

LA GESTIÓN DE PROYECTOS DENTRO DEL PROCESO DE DESARROLLO SOFTWARE

ResumenEste artículo contiene los resultados del estudio de algunos elementos de la ingeniería del software(un componente conceptual, base de la ingeniería, entre los cuales están los estándares, las buenas practicas, metodologías, técnicas y herramientas), desde el punto de vista de la gestión de proyectos. Los elementos de estudio seleccionados incluyen estándares sobre el proceso de desarrollo (IEEE Std 1074, IEEE/EIA 12207), prácticas de ingeniería del software (CMM) y metodologías de desarrollo software (Proceso Unificado, METRICA V3 y Programación Extrema). Los factores de la gestión de proyectos incluidos en el análisis son: la estimación, planificación, seguimiento y control del proyecto, gestión de configuración, gestión de calidad y gestión de personal.Palabras ClaveGestión de proyectos, Ingeniería del software, Proceso dedesarrollo softwar

Hybrid Biomass-Wind Power Plant For Reliable Energy Generation

[EN] Massive implementation of renewable energy resources is a key element to reduce CO2 emissions associated to electricity generation. Wind resources can provide an important alternative to conventional electricity generation mainly based on fossil fuels. However, wind generators are greatly affected by the restrictive operating rules of electricity markets because, as wind is naturally variable, wind generators may have serious difficulties on submitting accurate generation schedules on a day ahead basis, and on complying with scheduled obligations in real-time operation. In this paper, an innovative system combining a biomass gasification power plant, a gas storage system and stand-by generators to stabilize a generic 40 MW wind park is proposed and evaluated with real data. The wind park power production model is based on real data about power production of a Spanish wind park and a probabilistic approach to quantify fluctuations and so, power compensation needs. The hybrid wind-biomass system is analysed to obtain main hybrid system design parameters. This hybrid system can mitigate wind prediction errors and so provide a predictable source of electricity. An entire year cycle of hourly power compensations needs has been simulated deducing storage capacity, extra power needs of the biomass power plant and stand-by generation capacity to assure power compensation during critical peak hours with acceptable reliability.Pérez-Navarro, A.; Alfonso-Solar, D.; Álvarez, C.; Ibáñez, F.; Sánchez-Diaz, C.; Segura Heras, I. (2010). Hybrid Biomass-Wind Power Plant For Reliable Energy Generation. Renewable Energy. 35(7):1436-1443. https://doi.org/10.1016/j.renene.2009.12.0181436144335