Search results for "Maxim"
showing 10 items of 1236 documents
Bordón : revista de pedagogía
2013
Si hay algún elemento que ha destacado sobre otros en la historia de la educación infantil contemporánea, este ha sido, sin lugar a dudas, el juego. Es imposible desligar la actividad lúdica de la vida cotidiana de las primeras edades y, aunque el juego no se reduce únicamente a la infancia, podemos afirmar que el discurso pedagógico al respecto se ha centrado mayoritariamente en este periodo educativo. El presente artículo trata de esbozar algunos de los rasgos formativos del juego infantil, recurriendo para ello a la historia de la educación mediante el análisis de algunos de los discursos, prácticas y testimonios de destacados educadores y educadoras del siglo pasado, interesados todos e…
Integrating species distribution models (SDMs) and phylogeography for two species of AlpinePrimula
2012
The major intention of the present study was to investigate whether an approach combining the use of niche-based palaeodistribution modeling and phylo-geography would support or modify hypotheses about the Quaternary distributional history derived from phylogeographic methods alone. Our study system comprised two closely related species of Alpine Primula. We used species distribution models based on the extant distribution of the species and last glacial maximum (LGM) climate models to predict the distribution of the two species during the LGM. Phylogeographic data were generated using amplified fragment length polymorphisms (AFLPs). In Primula hirsuta, models of past distribution and phylo…
A geographical pattern ofAntirrhinum(Scrophulariaceae) speciation since the Pliocene based on plastid and nuclear DNA polymorphisms
2009
Aim To infer phylogenetic relationships among Antirrhinum species and to reconstruct the historical distribution of observed sequence polymorphism through estimates of haplotype clades and lineage divergence. Location Antirrhinum is distributed primarily throughout the western Mediterranean, with 22 of 25 species in the Iberian Peninsula. Methods Plastid (83 trnS-trnG and 83 trnK-matK) and nuclear (87 ITS) sequences were obtained from 96 individuals representing 24 of the 25 Antirrhinum species. Sequences were analysed using maximum parsimony, Bayesian inference and statistical parsimony networking. Molecular clock estimates were obtained for plastid trnK-matK sequences using the penalized …
BOD7 production function of the Finnish pulp and paper industry
2001
Traditional neoclassical production theory analyzes the relationship in a production process between inputs and outputs which have a positive market value for the producer. The externalities of production, which have nonpositive market values, are discarded or included as the cost in a cost function. This paper studies the relationship between biological oxygen demand (BOD) emissions, an output of nonpositive value, and traditional factors of production, that is, investments, labor, output, and raw materials. An emissions production function is theoretically presented and empirically estimated with data from the Finnish pulp and paper industry. The approach is based on the observation that …
Effects of the European Monetary Union on High-Technology Exports
2021
AbstractOur study estimates the effects of the European Monetary Union (EMU) on high-technology (HT) export and assesses the potential knowledge spillovers of such trade. Irrespective of the importance of the HT trade channel, none of the previous studies in the literature focus on the effects of a common currency on HT trade. Increasing trade in the HT sector may lead to more efficient use of resources and help countries to move towards a knowledge-based economy. Moreover, it may lead to higher overall growth. After considering multilateral resistances, pair fixed effects and bias correction in the preferred (three-way bias-corrected) model, EMU membership becomes negative and statisticall…
A numerical model of the cloud-topped planetary boundary-layer: influence of the physico-chemical properties of aerosol particles on the effective ra…
2000
The present investigation deals with the impact of different aeorosol types on the value of the effective radius of stratiform clouds. In several numerical sensitivity studies with the microphysical stratus model MISTRA, the aerosol composition was linearly changed from pure maritime to pure rural aerosol particles. Numerical results show that in environments with pure maritime aerosols, the effective radius is usually much larger than in continental regions. Values of the effective radius are also time-dependent with minima and maxima during day and night, respectively. In precipitating clouds, the effective radius might achieve values larger than 30 μm. In continental regions, the effecti…
Comparing conventional and organic citrus grower efficiency in Spain
2014
This paper compares the organic and conventional citriculture systems in Spain from the perspective of their technical efficiency. The primary objective of the research is to compare the relative efficiency of these two systems in relation to a metafrontier that envelops both technologies. In addition, the article analyses how efficient each growing system is at using its own technology, that is, when farms’ efficiency is benchmarked in relation to the best practices in their group. Contrary to conventional practice, farms’ performance is analyzed in terms of specific growing tasks: soil and plant cover management, pruning, fertilization and phytosanitary treatments. The results obtained hi…
An entropy-based machine learning algorithm for combining macroeconomic forecasts
2019
This paper applies a Machine Learning approach with the aim of providing a single aggregated prediction from a set of individual predictions. Departing from the well-known maximum-entropy inference methodology, a new factor capturing the distance between the true and the estimated aggregated predictions presents a new problem. Algorithms such as ridge, lasso or elastic net help in finding a new methodology to tackle this issue. We carry out a simulation study to evaluate the performance of such a procedure and apply it in order to forecast and measure predictive ability using a dataset of predictions on Spanish gross domestic product.
Optimal Operating Point Calculation for Medium Voltage Distribution Systems
2007
The paper deals with the calculation of the optimal working point of a distribution system, equipped with several distributed generators, able to operate also autonomously, i.e. disconnected from the main grid. When connected to the main grid, it appears in general convenient to assign the slack bus role to the bus that represents such a connection. The problem becomes more complex when maximum power transfer constraints through the connection must be taken into account. The adequate slack bus treatment is even more important when the optimal operating condition must refer to the condition subsequent to an intentional or unintentional disconnection from the main grid. The paper presents an …
Near-intrinsic energy resolution for 30-662 keV gamma rays in a high pressure xenon electroluminescent TPC
2013
We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time projection chamber (TPC) that was built at the Lawrence Berkeley National Laboratory. It is a prototype of the planned NEXT-100 Xe-136 neutrino-less double beta decay (0 nu beta beta) experiment with the main objectives of demonstrating near-intrinsic energy resolution at energies up to 662 keV and of optimizing the NEXT-100 detector design and operating parameters. Energy resolutions of similar to 1% FWHM for 662 keV gamma rays were obtained at 10 and 15 atm and similar to 5% FWHM for 30 keV fluorescence xenon X-…