Psychometric behaviour of the strengths and difficulties questionnaire (SDQ) in the Spanish national health survey 2006

Background: The Strengths and Difficulties Questionnaire (SDQ) is a tool to measure the risk for mental disorders in children. The aim of this study is to describe the diagnostic efficiency and internal structure of the SDQ in the sample of children studied in the Spanish National Health Survey 2006. Methods: A representative sample of 6,773 children aged 4 to 15 years was studied. The data were obtained using the Minors Questionnaire in the Spanish National Health Survey 2006. The ROC curve was constructed and calculations made of the area under the curve, sensitivity, specificity and the Youden J indices. The factorial structure was studied using models of exploratory factorial analysis (EFA) and confirmatory factorial analysis (CFA). Results: The prevalence of behavioural disorders varied between 0.47% and 1.18% according to the requisites of the diagnostic definition. The area under the ROC curve varied from 0.84 to 0.91 according to the diagnosis. Factor models were cross-validated by means of two different random subsamples for EFA and CFA. An EFA suggested a three correlated factor model. CFA confirmed this model. A five-factor model according to EFA and the theoretical five-factor model described in the bibliography were also confirmed. The reliabilities of the factors of the different models were acceptable (>0.70, except for one factor with reliability 0.62). Conclusions: The diagnostic behaviour of the SDQ in the Spanish population is within the working limits described in other countries. According to the results obtained in this study, the diagnostic efficiency of the questionnaire is adequate to identify probable cases of psychiatric disorders in low prevalence populations. Regarding the factorial structure we found that both the five and the three factor models fit the data with acceptable goodness of fit indexes, the latter including an externalization and internalization dimension and perhaps a meaningful positive social dimension. Accordingly, we recommend studying whether these differences depend on sociocultural factors or are, in fact, due to methodological questions.

Facebook in teaching: strengths and weaknesses

Purpose – The use of online social networks has experienced a vertiginous increase in the last few years, and young people appear as the key players in this trend. Immersed, educated and raised in the middle of technology, the new student generation is one of digital natives. Instead, lecturers are digital immigrants, but the authors have the responsibility to turn a technology which can be a distraction into a teaching tool. Facebook is an example of Web 2.0 technology that owns a huge potential in the field of education. The purpose of this paper is to show the teaching experience with the Facebook social network in human resource management degree subjects, for the purpose of highlighting its strengths and weaknesses. Design/methodology/approach – A survey was carried out among university students in order to reach the goal. A total of 191 students were asked to give their opinion about the use of Facebook in teaching, achieving 125 valid answers. Findings – Facebook can positively impact on the performance of students, who are satisfied with the experience and think that the information obtained in Facebook can improve their training. More negative attitudes towards Facebook appeared among those students who had not used it. Originality/value – The paper summarises the strengths and weaknesses of Facebook through a literature review and assesses them via a survey.

Etude comparative de l’anatomie racinaire de deux taxons Lygeum spartum L. et Ammophila arenaria (L.) Link. (Oranie – Algérie)

Cette approche histométrique traite la description des tissus constituants les êtres vivants de deux espèces végétales vivaces (Lygeum spartum et Ammophila arenaria). Elle permettra d’aider à comprendre certainement le comportement tant morphologique que physiologique de l’espèce vivante dans un biotope naturel. Présentant des racines adaptatives à l’absorption de l’eau et des sels minéraux du sol, ces deux espèces montrent une fixation de la plante au substrat et à l’accumulation des réserves. Elles sont sous la dépendance de corrélations com plexes (trophiques, hormonales) qui s’établissent entre l’appareil souterrain et l’appareil aérien. L’étude histométrique du Lygeum spartum et d’Ammophila arenaria nous a permis de déterminer une nette différence entre les tissus des deux espèces. Pour Ammophila arenaria, il existe de très bonnes corrélations pour la majorité des tissus, expliquant ainsi une croissance cellulaire qui existe entre ces différents tissus.Le coefficient de corrélation est faible entre les différents tissus du Lygeum spartum. Le développment des tissus de celle-ci n’est pas synchrone, il montre toute même une certaine hétérogéneité au niveau du développement tissulaire des racines.

Missing Rings in Pinus halepensis – The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events

Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees to adverse environmental conditions. The demonstrated relationship of MR formation to ECE across this dendrochronological network in the Mediterranean basin shows the potential of MR analysis to reconstruct the history of past climatic extremes and to predict future forest dynamics in a changing climate.