657 research outputs found
The internationalisation of Spanish SMEs : main developments and their determinants
ArtĂculo de revist
Socio-emotional intervention in attention deficit hyperactive disorder
Attention-deficit-hyperactivity disorder (ADHD) is a common neuro-behavioural disorder with onset in childhood. These children have impaired emotional self-control, self- regulation of drive and motivation. Numerous studies have reported cognitive disabilities in memory, executive functions, spatial abilities and language skills. The main objective of this work is to determine whether a socio-emotional intervention programme could improve execu- tive functions in children with Attention Deficit Hyperactivity Disorder. The sample of this study consisted of 25 children (8 female and 17 male) aged between 8 and 12 years, diagnosed with ADHD and who were not taking any psychopharmacological treatment at the time of the study, and had not taken medication previously. Executive functioning was assessed through the Zoo Map test and Tower of Hanoi puzzle in pre-/post-test design. A socio-emotional intervention programme was implemented. The training consisted of 8 one-hour weekly sessions, on an indi- vidual basis. Results indicate that such a programme does lead to improved performance in the execution of tasks that evaluate executive functions. After the intervention, the children took less time to resolve the Zoo Map test. Results for the Hanoi Tower puzzle were also improved after intervention. The children needed a lower number of movements to complete the task
Firm heterogeneity and aggregate business services exports : micro evidence from Belgium, France, Germany and Spain
En este trabajo se emplean microdatos de exportaciones de servicios desagregados por empresa-destino-tipo de servicio con la finalidad de analizar cĂłmo afectan las caracterĂsticas de las empresas a las exportaciones agregadas de servicios en BĂ©lgica, Francia, Alemania y España para el perĂodo 2003-2007. El nivel y el crecimiento de las exportaciones agregadas se descomponen en diferentes mĂĄrgenes, prestando una atenciĂłn especial a la heterogeneidad empresarial dentro de cada paĂs. Los resultados corroboran que el dĂ©bil crecimiento de las exportaciones en Francia refleja, al menos parcialmente, el dĂ©bil dinamismo de los pequeños exportadores. En contraste, este grupo de empresas es el mĂĄs dinĂĄmico en el resto de los paĂses de la muestra. Nuestros resultados subrayan la relevancia de la heterogeneidad empresarial para explicar la evoluciĂłn de las exportaciones agregadasThis paper uses detailed micro data on service exports at the firm-destination-service level to analyse the role of firm heterogeneity in shaping aggregate service exports in Belgium, France, Germany and Spain from 2003 to 2007. We decompose the level and the growth of aggregate service exports into different trade margins paying special attention to firm heterogeneity within countries. We find that the weak export growth of France is at least partly due to poor performance by small exporters. By contrast, small exporters are the most dynamic contributors to the aggregate exports of Belgium, Germany and Spain. Our results highlight the importance of firm heterogeneity in understanding aggregate export growt
Vitrification of Donkey Sperm: Is It Better Using Permeable Cryoprotectants?
Vitrification by direct exposure of sperm to liquid nitrogen is increasing in popularity as an alternative to conventional freezing. In this study, the effect of permeable cryoprotectant agents for donkey sperm vitrification was compared to an extender containing non-permeable cryoprotectants. First, three different concentrations of sucrose (0.1, 0.2, and 0.3 molar, M) and bovine serum albumin, BSA (1, 5, and 10%) were compared. Secondly, the concentration of non-permeable agents producing the most desirable results was compared to an extender containing glycerol as permeable agent. Vitrification was performed by dropping 30 ΌL of sperm suspension directly into LN2 and warming at 42 °C. Sperm motility (total, TM; and progressive, PM) and plasma membrane integrity, PMI (mean ± SEM) were statistically compared between treatments. Sucrose 0.1 M showed a significantly higher percentage of total sperm motility (21.67 ± 9.22%) than sucrose 0.2 M (14.16 ± 4.50%) and 0.3 M (8.58 ± 6.22%); and no differences were found in comparison to the control (19.71 ± 10.16%). Vitrification with sucrose 0.1 M or BSA 5% obtained similar results for TM (21.67 ± 9.22% vs. 19.93 ± 9.93%), PM (13.42 ± 6.85% vs. 12.54 ± 6.37%) and PMI (40.90 ± 13.51% vs. 37.09 ± 14.28); but both showed higher percentages than glycerol (TM = 9.71 ± 4.19%; PM = 5.47 ± 3.17%; PMI = 28.48 ± 15.55%). In conclusion, donkey sperm vitrification in spheres using non-permeable cryoprotectants exhibited better sperm motility and viability parameters after warming than sperm vitrification using extenders containing permeable cryoprotectants
On weighted L_p-spaces of vector-valued entire analytic functions
[EN] The weighted L p -spaces of entire analytic functions are generalized to the vector-valued setting. In particular, it is shown that the dual of the space LKp,Âż(E) is isomorphic to LÂżKpÂż,¿¿1(EÂż) when the function Âż K is an L p,Âż (E)-Fourier multiplier. This result allows us to give some new characterizations of the so-called UMD-property and to represent several ultradistribution spaces by means of spaces of vector sequences.Motos Izquierdo, J.; Planells Gilabert, MJ.; Talavera Usano, CF. (2008). On weighted L_p-spaces of vector-valued entire analytic functions. Mathematische Zeitschrift. 260(2):451-472. doi:10.1007/s00209-007-0283-4S4514722602Aldous D.J. (1979). Unconditional bases and martingales in L p (F). Math. Proc. Camb. Phil. Soc. 85: 117â123Amann H. (1997). Operator-valued Fourier multipliers, vector-valued Besov spaces and applications. Math. Nachr. 186: 5â56Björck G. (1966). Linear partial differential operators and generalized distributions. Ark. Mat. 6: 351â407Bourgain J. (1984). Some remarks on Banach spaces in which martingale difference sequences are unconditional. Ark. Mat. 22: 163â168Burkholder, D.L.: A geometrical condition that implies the existence of certain singular integrals of Banach-space-valued functions. In: Proceedings of conference on Harmonic analysis in Honour of Antoni Zygmund, Chicago 1981 (Belmont Cal., Wadsworth), pp. 270â286 (1983)Capon M. (1983). PrimaritĂ© de L p (X). Trans. Am. Math. Soc. 276: 431â487Coifman R.R. and Fefferman C. (1974). Weighted norm inequalities for maximal functions and singular integrals. Stud. Math. 51: 241â250Defant M. (1989). On the vector-valued Hilbert transform. Math. Nachr. 141: 251â265Diestel, J., Uhl, J.J.:Vector measures, Mathematical Surveys, no. 15, Am. Math. Soc., Providence (1977)Dinculeanu N. (1967). Vector Measures, International Series of Monographs in Pure and Applied Mathematics, no. 95. Pergamon, New YorkFefferman C. (1971). The multiplier problem for the ball. Ann. Math. 94: 330â336Frazier M., Jawerth B., Weiss G. (1991) LittlewoodâPaley theory and the study of function spaces. In: CBMS Regional Conference on Series Mathematics, no. 79. AMS, ProvidenceGarcĂa-Cuerva, J., Rubio de Francia, J.L.: Weighted norm inequalities and related topics, North Holland Mathematical Studies, vol. 116, Amsterdam (1985)Grothendieck, A.: Produits tensoriels topologiques et espaces nuclĂ©aires. Mem. Am. Math. Soc., no. 16, AMS, Providence (1955)Grudzinski O. (1979). Temperierte Beurling-distributionen. Math. Nachr. 91: 297â320Holub J.R. (1971). Hilbertian operators and reflexive tensor products. Pacific J. Math. 36: 185â194Hörmander L. (1960). Estimates for translation invariant operators on L p spaces. Acta Math. 104: 93â139Hörmander L. (1983). The Analysis of Linear Partial Differential Operators II, Grundlehren, no. 257. Springer, BerlinKomatsu H. (1973). Ultradistributions I. Structure theorems and a characterization. J. Fac. Sci. Univ. Tokyo. Sect. IA Math. 20: 25â105Komatsu H. (1982). Ultradistributions III. Vector-valued ultradistributions and the theory of kernels. J. Fac. Sci. Univ. Tokyo. Sect. IA Math. 29: 653â718Lindenstrauss J. and PeĆczyĆski A. (1968) Absolutely summing operators in spaces and their applications. Stud. Math. 29: 275â326Lindenstrauss J. and Tzafriri L. (1977). Classical Banach spaces I. Springer, HeidelbergLöfstrom J. (1982) Interpolation of weighted spaces of differentiable functions on . Ann. Math. Pura Appl. 132: 189â214Mitiagin B.S. (1972). On idempotent multipliers in symmetric functional spaces. Funkcional Anal. i PriloĆŸen 6: 81â82Motos, J., Planells, M.J., Talavera, C.F.: On some iterated weighted spaces. J. Math. Anal. Appl. 338, 162â174 (2008) doi: 10.1016/j.jmaa.2007.05.009Muckenhoupt B. (1972). Weighted norm inequalities for the Hardy maximal function. Trans. Am. Math. Soc. 165: 207â226Nikolâskij S.M. (1975). 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Tax fraud detection through neural networks: An application using a sample of personal income taxpayers
The goal of the present research is to contribute to the detection of tax fraud concerning
personal income tax returns (IRPF, in Spanish) filed in Spain, through the use of Machine Learning
advanced predictive tools, by applying Multilayer Perceptron neural network (MLP) models.
The possibilities springing from these techniques have been applied to a broad range of personal
income return data supplied by the Institute of Fiscal Studies (IEF). The use of the neural networks
enabled taxpayer segmentation as well as calculation of the probability concerning an individual
taxpayerâs propensity to attempt to evade taxes. The results showed that the selected model has an
efficiency rate of 84.3%, implying an improvement in relation to other models utilized in tax fraud
detection. The proposal can be generalized to quantify an individualâs propensity to commit fraud
with regards to other kinds of taxes. These models will support tax offices to help them arrive at the best decisions regarding action plans to combat tax frau
Is Open Science the Same as Open Source Science?
How open source hardware and software can help to level up open science into open research when used for both methods and tools in the research activities
Open source hardware based sensor platform suitable for human gait identification
Most initiatives about embedded sensing capabilities in computational systems lead to de-
vise an ad hoc sensor platform, usually poorly reusable, as a first stage to prepare a data
corpus or production prototype. In this paper, an open source hardware platform for sensing is described. This platform was intended to be used in data acquisition for gait identification, and is designed in a way general enough so many other projects could reuse the design to accelerate prototyping. The platform is based on popular open source hardware and software like Arduino and Raspberry Pi using well known languages and libraries. Some experimental results about the throughput of the overall system are reported showing the feasibility of acquiring data from up to 6 sensors with a sampling frequency no less than 118 Hz
Factor analysis of organizational justice : the case of Ecuador
Purpose: Organizational Justice (JO) is an important predictor of different attitudes and organizational behavior. ΀he Colquitt organizational scale of justice was developed to assess the perceptions of Justice in employees (for this case university professors) and it has four dimensions: distributive, procedural, interpersonal and informational justice. For this work we extend the analysis to the Ecuadorian context using a model that was applied in Spain. Design/Methodology/Approach: The Cronbach alpha obtained for each dimension varied between .98 and .99 with a measure of sampling adequacy KMO of .9663. The corresponding factor analysis, includes items on 3 factors that account for 98% of the variance, so it is confirmed that it is an instrument that has the adequate psychometric properties for its use in the ecuadorian context.
Findings: The institutions of public higher education of Ecuador, go through a significant stage of change and transformation from the political to the academic in which short-term changes are proposed regarding the normative and that is where it is necessary to study the processes of organizational change, and achieve greater assimilation through the management of elements such as the perceptions of justice that can lead to these being assimilated in a better way. Practical Implications: From the four dimensions identified by Colquitt, the one showing a higher percentage of acceptance was the interpersonal with a rate of 86.1%. Originality/Value: The objective of this study is to assess the scale of organizational Justice of Colquitt and to determine the perception of teachers in public universities in Ecuador. In addition, five questions that refer to the use of ICT in the different dimensions in a sample of 500 professors were included.peer-reviewe
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