Color characterization of roofing slates from the Iberian Peninsula for restoration purposes

Substitution of slate roofing tiles is a conventional operation during building restoration, since tiles are very difficult to restore or clean because of the high degree of alteration they suffer. Criteria for replacement of historical building stones must be based on geological, geotechnical and esthetic parameters, among which color is of great importance. In this sense, this paper constitutes a comprehensive and useful colorimetric study of roofing slates from the Iberian Peninsula, for the purposes of restoration. The color of 50 commercial varieties of roofing slate mined in quarries from the 12 mining districts in the Iberian Peninsula was analyzed with a spectrophotometer device, by considering the CIELAB color space. The results of the study were used to develop a protocol for characterizing the color of roofing slate and to define the color range of roofing slate from the Iberian Peninsula. In addition, the similarities and differences in the color and microstructure of the different commercial varieties of Iberian roofing slate were established and the limit of acceptability of replacement of one type of slate by another was determined. Parameter h_ab was found to be the most important CIELAB color coordinate as regards the formation of homogeneous color groups, and the specular component excluded (SCE) mode was most sensitive as regards detecting color differences between two samples.     

Languages,Minorities and Education in Spain: The case of Catalonia

The intent of the article is to provide an analysis of Catalan language use in the school classroom from a historical, political and socio-linguistic perspective. In so doing, this article seeks to explain Catalan's remarkable revival in Catalonia over the past twenty years, particularly in the area of education. Catalan language policy in the schools mirrors language policies pursued in other sectors of Catalan society, and is consistent with Catalan's increasing social and institutional use. The article steadily narrows the focus of its analysis, beginning first with a discussion at the national level, then at the regional level, and finally at the school level. Subsequent to this analysis, the article then sets out what it considers to be the principal challenges facing Catalan in the schools today and in the years ahead, and possible solutions to them.     

The Effect of Sampling-Time Variation on Latent Growth Curve Models

Longitudinal data are often collected in waves in which a participant’s data can be collected at different times within each wave, resulting in sampling-time variation that is unaccounted for when waves are treated as single time points. Little research has been reported on the effects of this temporal imprecision on longitudinal growth-curve modeling. This article describes the results of a simulation study into the effect of sampling-time variation on parameter estimation, model fit, and model comparison with an empirical validation of the model fit and comparison results.     

Antioxidant response and oxidative damage induced by a swimming session: influence of gender

In this study, we examined oxidative stress after a swimming session, the responses of the antioxidant defences, and the influence of gender on these responses. Fifteen boys and eight girls participated voluntarily in the study. Plasma concentrations of 17-beta-estradiol, vitamin E, retinol, carotenes, ascorbate, malondialdehyde, and the carbonyl index were determined. Creatine kinase, gamma glutamyl transpeptidase, and lactate dehydrogenase activities, as well as glucose, urea, urate, cholesterol, and triglycerides, were determined in serum. Plasma concentrations of 17-beta-estradiol were higher in girls than in boys. Exercise increased plasma ascorbate both in boys and in girls. Malondialdehyde increased in boys but was maintained in girls after exercise. Creatine kinase values corrected for lean body mass were similar in boys and girls at baseline, but the post-exercise values in boys were higher than in girls. A positive correlation was observed in boys, but not in girls, between plasma malondialdehyde and creatine kinase corrected concentrations. Furthermore, a negative correlation was observed between the increase in circulating neutrophils and in creatine kinase activity in girls but not in boys. In conclusion, a swimming session induced higher muscular and oxidative damage in boys than in girls.     

Do Parents Foster Self‐Esteem? Testing the Prospective Impact of Parent Closeness on Adolescent Self‐Esteem

Close parent–child relationships are viewed as important for the development of global self‐esteem. Cross‐sectional research supports this hypothesis, but longitudinal studies provide inconsistent prospective effects. The current study uses data from Germany (N = 982) and the United States (N = 451) to test longitudinal relations between parent–child closeness and adolescent self‐esteem. The authors used self‐, parent‐, and observer‐reported parent–child closeness and self‐reported self‐esteem from ages 12 to 16. Results replicated concurrent correlations found in the literature, but six longitudinal models failed to show prospective relations. Thus, the longitudinal effect of parent–child closeness and self‐esteem is difficult to detect with adolescent samples. These findings suggest the need for additional theorizing about influences on adolescent self‐esteem development and longitudinal research with younger samples.     

Do researchers collaborate in a similar way to publish and to develop projects?

The aim of this paper is to establish the similarities and differences between the way of collaboration and the production of researchers when dealing with publications or with the development of projects and whether the collaboration patterns change across disciplines.We have studied the networks of researchers formed through the collaborations in papers or in projects in a research institution (the University of Zaragoza) and we have analyzed a series of individual and global magnitudes. As a general result, we have observed that the laws governing the individual productivity are similar for the cases of publications and projects but, however, the behavior is different when analyzing more complex magnitudes such as the collaborations or other structural variables. We consider also the subnetworks defined by the researchers of the different disciplines and characterize their topologies and compare the corresponding collaboration patterns.Because of the general approach, we expect most of the conclusions to be applicable to other universities or research centers.