Search

A peloid’s liquid phase can be mineral, sea or salt-lake water. This study examines the interactions among three materials, two special clays (bentonite and sepiolite) and one common clay, and three chemically different mineral-medicinal waters. In all clay–water mixtures, the hardness and adhesiveness decreased with the amount of water in the mixture. For a given hardness or adhesiveness, sepiolite retained more water than the other clays, especially in the presence of sulphate-rich mineral-medicinal water (73%). In contrast, the common clay retained the least amount of water (26%), and the bentonite samples returned an intermediate value for the amount of retained water (52–53%). These differences had a strong influence on the thermal behaviour of the mixtures and, hence, should be taken into account for their use in thermotherapy applications. There were no significant differences in the instrumental texture of the clay pastes according to the predominant anion in the mineral-medicinal waters., Depto. de Radiología, Rehabilitación y Fisioterapia, Fac. de Medicina, TRUE, pub

La población infantil representa uno de los colectivos de riesgo con mayor vulnerabilidad frente a los factores ambientales propios del entorno en el que vive, debido a la inmadurez fisiológica y al carácter crítico de su desarrollo físico y mental. La incidencia de patologías respiratorias entre la población pediátrica ha aumentado significativamente en los últimos años, apuntándose la deficiente calidad del aire que se respira en los núcleos urbanos como una de las principales causas de dicho incremento. El presente trabajo es un estudio epidemiológico restrospectivo de series temporales, que se ha llevado a cabo para comprobar los efectos que los diferentes factores ambientales atmosféricos tienen sobre la salud infantil, en particular patologías de tipo respiratorio, en una gran ciudad como el municipio de Alcalá de Henares (Madrid), durante el año 2010. Para ello, se evaluó la posible influencia de parámetros de tipo meteorológico (temperatura, humedad relativa, viento), de contaminación química (SO2, CO, NOx, PM10 y O3) y contaminación biológica (pólenes y esporas) sobre patologías de tipo respiratorio, empleando la variable clínica Nº. Visitas a los Servicios de Urgencias del Hospital Universitario Príncipe de Asturias. Se trata de una iniciativa singular, ya que la mayoría de las referencias bibliográficas encontradas hacen hincapié en partes concretas de la problemática, pero adolecen de una visión conjunta como la que se plantea en el presente estudio..., Child population is considered a high-risk group in terms of vulnerability against the specific environmental factors of the ecosystem where they live, physiological immaturity and critical nature of its physical and psychical growth representing the key issues of such particular behaviour. The incidence of respiratory diseases and conditions has been shown to follow an increasing trend during recent decades as a consequence, among others, of the lessened air quality indicators measured in the atmosphere of many urban agglomerations. Based on a retrospective approach, this epidemiological study aims to assess the potential effects of several atmospheric environmental factors on childhood health, with particular emphasis on respiratory diseases and conditions, in a large urban core like Alcalá de Henares during year 2010. Thereby, the effect and potential influence of meteorological (temperature, relative humidity, wind) as well as chemical (SO2, CO, NOx, PM10 and O3) and biotic pollution (pollen and spores) variables on childhood respiratory conditions (0-14 years of age) in the city of Alcalá de Henares were evaluated. Number of visits to hospital emergency services of Hospital Principe de Asturias was used as indicator of clinical response. Many references of similar approaches have been previously reported in the literature, but few examples encompassed such comprehensive and integral approach as in present study...

La población infantil representa uno de los colectivos de riesgo con mayor vulnerabilidad frente a los factores ambientales propios del entorno en el que vive, debido a la inmadurez fisiológica y al carácter crítico de su desarrollo físico y mental. La incidencia de patologías respiratorias entre la población pediátrica ha aumentado significativamente en los últimos años, apuntándose la deficiente calidad del aire que se respira en los núcleos urbanos como una de las principales causas de dicho incremento. El presente trabajo es un estudio epidemiológico restrospectivo de series temporales, que se ha llevado a cabo para comprobar los efectos que los diferentes factores ambientales atmosféricos tienen sobre la salud infantil, en particular patologías de tipo respiratorio, en una gran ciudad como el municipio de Alcalá de Henares (Madrid), durante el año 2010. Para ello, se evaluó la posible influencia de parámetros de tipo meteorológico (temperatura, humedad relativa, viento), de contaminación química (SO2, CO, NOx, PM10 y O3) y contaminación biológica (pólenes y esporas) sobre patologías de tipo respiratorio, empleando la variable clínica Nº. Visitas a los Servicios de Urgencias del Hospital Universitario Príncipe de Asturias. Se trata de una iniciativa singular, ya que la mayoría de las referencias bibliográficas encontradas hacen hincapié en partes concretas de la problemática, pero adolecen de una visión conjunta como la que se plantea en el presente estudio...

Brief Counseling Intervention (BCI) and Medical advice (MA) are psychotherapeutic approaches used for the treatment of binge drinkers in Primary Care. Although binge drinking is a common pattern of alcohol misuse in Europe and in the US, no studies have evaluated those subjects who do not respond to Brief Counseling Interventions or Medical Advice. Objective. To determine the clinical and demographic characteristics of binge drinkers in whom BCI or MA are not effective in reducing harmful alcohol use. Methods. This is a secondary analysis of data from a randomized alcohol brief intervention trial with a 12-month follow-up period. A total of 674 subjects (89%) participated right through to the end of the study. The primary outcome measure was change in harmful alcohol use from baseline to 12 months. Results. The strongest baseline predictors of harmful alcohol use during follow-up were educational status, young adults, and high number of cigarettes smoked, present family history of alcoholism, treatment condition and number of drinks per episode of binge drinking. Conclusions. Binge drinkers are a heterogeneous group that responds to brief intervention or MA but in a subgroup of them these interventions fail to prevent harmful alcohol use. Other interventions should be implemented for these subjects., Depto. de Estadística e Investigación Operativa, Depto. de Medicina Legal, Psiquiatría y Patología, Fac. de Ciencias Matemáticas, Fac. de Medicina, TRUE, pub

The geographic and demographic dimensions of Spain, in terms of surface and number of inhabitants, and its heterogeneous socioeconomic development offer an adequate opportunity to study the provincial differences in birth weight from 1996 to 2010, focusing on possible factors determining the relative frequency of low birth weight. The study analysed geographic differences with regard to biological, demographic and socioeconomic factors that interfere with the female reproductive pattern. The variables considered here were: birth order, proportion of premature deliveries, mother's age, multiparity, mother's country of origin and professional qualifications. Two periods (1996–2000 and 2006–2010) were compared by means of principal components analysis. An increase in the relative frequency of deliveries weighing less than 2500 g occurred in most of the 52 geographic units studied, differences being significant in 42. Only in five cases was there a non-significant reduction in the proportion of low weight births. The first component after principal component analysis indicated that low birth weight was positively related to maternal age and to multiple deliveries, and negatively to the mother's low professional qualification. The second component related positively to the incidence of premature deliveries and to non-Spanish status and negatively in the case of primiparous mothers. The progressive increase in low birth weight incidence observed in Spain from 1996 onwards has occurred with considerable variation in each province. In part, this diversity can be attributed to the unequal reproductive patterns of immigrant mothers., e Spanish Ministry of Science and Innovation, Depto. de Biodiversidad, Ecología y Evolución, Sección Deptal. de Sistemas Informáticos y Computación, Fac. de Ciencias Biológicas, Fac. de Ciencias Matemáticas, TRUE, pub

Background: This analysis focuses on determining differences in the risk of stillbirth in Spain by comparing native and foreign mothers with regard to bio-demographic factors. Methods: The study is based on micro-data, one record per delivery for 2,869,329 births occurring from 2007 to 2012. Results: For a total of 2,287,819 single deliveries the average stillbirth rate for Spanish mothers (S) was 2.51 per 1000; for non-Spanish mothers (NS) it was 3.99 per 1000. Two multivariate Poisson regression models were applied to obtain adjusted stillbirth risk ratios (RR), one for S and another for NS mothers. For both groups the following variables were included in the model: Caesarean, mother’s age, birth weight, duration of gestation, and maternal education. Parity, however, was incorporated only for Spanish mothers, while for the non-Spanish the relationship status and the father’s nationality were included. The increase in RR is similar for certain variables, such as in cases where no Caesarean was performed (S: 3.356; NS: 3.439); while for other variables differences are observed with regard to maternal origin, for example weight at birth <1500g in relation to ≥ 2500g (S: 4.154; NS: 21.367). Conclusions: Immigration, together with differential reproductive maternal characteristics, had an influence on RR. Maternal education, as an indicator of socioeconomic conditions, is one of the most important socio-cultural variables in this respect. Certain reproductive and socio-cultural maternal variables affected RR differently in Spanish and foreign women, suggesting the benefit of implementing policies to achieve a decrease in the risk of stillbirths in the NS group., Spanish Ministry of Science and Innovation, Depto. de Biodiversidad, Ecología y Evolución, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Biológicas, Fac. de Ciencias Matemáticas, TRUE, pub

Adolescent fertility displays a trend that does not follow—and even runs contrary to—the general temporal fertility pattern. Multiple factors determine this trend, including socioeconomic conditions and cultural patterns at both immigrants’ place of origin of and their destination. This article analyzes adolescent fertility in Spain with regard to country of maternal origin using records of deliveries (1980–2008) and information from countries with high immigration rates to Spain. After 1980, deliveries to adolescents diminished; after 1996, only Spanish-born adolescents continued this downward trend, but not immigrants. The factors responsible for these differences are diverse and related to the characteristics of the immigrants themselves, in addition to the situation of immigrants in the Spanish context., Depto. de Biodiversidad, Ecología y Evolución, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Biológicas, Fac. de Ciencias Matemáticas, TRUE, pub

The present analysis compares the distribution of surnames by means of spatial autocorrelation analysis in the Spain–Portugal border region. The Spanish National Institute of Statistics provides a database of surnames of residents in the western Spanish provinces of Zamora, Salamanca, Cáceres, Badajoz and Huelva. The Spanish and Portuguese patterns of surname distribution were established according to various geographic axes. The results obtained show a low diversity of surnames in this region – especially in the centre – which can be explained by the absence of any major geographic barriers, with the exception of the mountain ranges between hydrographic basins, and by the presence of traditional roads that have existed since Roman times. The latter have resulted in a constant migratory flow over short–median distances, which, as can be deduced from the surnames, fits two north/south territorial axes running parallel to the border between Spain and Portugal. The distribution patterns of Portuguese and Spanish surnames differ with regard to their frequencies in the five provinces studied, which can be attributed to their respective historical, economic and social conditions. It is concluded that the border delimiting these two countries has affected the migratory flow, thereby conditioning the demographic and genetic structure of the western Spanish regions., Depto. de Biodiversidad, Ecología y Evolución, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Biológicas, Fac. de Ciencias Matemáticas, TRUE, pub

New diagnostic criteria for Alzheimer's disease (AD) stress the role of in vivo biomarkers. Neurophysiological markers are usually not considered as such criteria, although theoretical and practical reasons would justify them. In order to assess the value of neurophysiology as an AD biomarker, whole-head magnetoencephalographic (MEG) resting state recordings were obtained from 35 AD patients, 23 mild cognitive impairment (MCI) patients, and 24 healthy controls. The AD group was further split into two groups differing in severity according to the GDS/FAST criteria. A Minimum Norm Estimation procedure was utilized to estimate the cortical origin of slow brain oscillatory activity in the delta band (2–4 Hz). Eight regions of interest (ROIs) discriminated between AD patients and controls. Delta current density (DCD) in all ROIs showed a significant negative correlation with cognitive status (p < 0.001). DCD values in posterior parietal, occipital, prerolandic, and precuneus cortices distinguished reliably between MCI patients, AD patients with different severity scores, and controls. Importantly, an increase of DCD in right parietal cortex and precuneus indexed the transition from MCI to mild dementia and from mild to more severe dementia. MEG delta mapping might be a serious candidate for a “neural degeneration” marker of AD reflecting dysfunctional synaptic transmission. More importantly, the localization of DCD values is in line with functional imaging markers of AD. However, MEG delta mapping is a totally non-invasive technique that directly measures neural activity. We propose that individuals with enhanced DCD in posterior parietal and precuneus cortices are at risk of progression to full dementia., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Background: Low weight and premature deliveries arouse clinical interest concerning the survival of newborns. The determinants of birth weight among Spanish natives and immigrants may differ. Research which considers maternal origin and associated factors such as age and parity is important. Aim: This study analyses and models the influence of the rapid and intense arrival of immigrants in Spain on birth weight variation. Method: Data on deliveries from the Spanish National Institute for Statistics (n = 9 443 882) are analysed regarding low birth weight, premature births and other variables. The inter-relation among these variables was interpreted by means of logistic regression models. Results and conclusions: The birth weight has decreased since 1980 in Spain, but has slightly recovered in recent years. Meanwhile the percentage of foreign maternities increased to 17.3% in 2010. Logistic regression models assess the different influence of variables known to determine low birth weight (weeks of gestation, sex, etc.) and other maternal characteristics (age at delivery, professional activity, etc.). The progressively greater contribution of foreign women to total births in Spain and their differential numerical input to the various risk groups have slowed the pattern of reduction in the mean weight of newborns in this country., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Magnetoencephalography (MEG) allows the real-time recording of neural activity and oscillatory activity in distributed neural networks. We applied a non-linear complexity analysis to resting-state neural activity as measured using whole-head MEG. Recordings were obtained from 20 unmedicated patients with major depressive disorder and 19 matched healthy controls. Subsequently, after 6 months of pharmacological treatment with the antidepressant mirtazapine 30 mg/day, patients received a second MEG scan. A measure of the complexity of neural signals, the Lempel–Ziv Complexity (LZC), was derived from the MEG time series. We found that depressed patients showed higher pre-treatment complexity values compared with controls, and that complexity values decreased after 6 months of effective pharmacological treatment, although this effect was statistically significant only in younger patients. The main treatment effect was to recover the tendency observed in controls of a positive correlation between age and complexity values. Importantly, the reduction of complexity with treatment correlated with the degree of clinical symptom remission. We suggest that LZC, a formal measure of neural activity complexity, is sensitive to the dynamic physiological changes observed in depression and may potentially offer an objective marker of depression and its remission after treatment., Organon S.A. Spain, Depto. de Medicina Legal, Psiquiatría y Patología, Depto. de Estadística e Investigación Operativa, Fac. de Medicina, Fac. de Ciencias Matemáticas, TRUE, pub

The effect of adiponectin and leptin on the proliferation of the human microvascular endothelial cell line (HMEC-1) was studied in the absence or presence of fetal bovine serum (FBS). The participation of extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase/Akt (PI-3K/Akt) pathways in this effect were evaluated. We studied the effect of both adipokines on the motility, mitosis, proliferation and cell death processes of HMEC-1 cells using live-cell imaging techniques. Adiponectin but not leptin further increased the proliferative effect induced by FBS on HMEC-1. This effect seems to be the consequence of an increase in the mitotic index in adiponectin-treated cells when compared to untreated ones. The presence of either the mitogen-activated protein kinase (MAPK) inhibitor (PD98059), or PI-3K inhibitor (LY294002), reduced the effect of adiponectin in a dose-dependent manner. Neither adipokine was able to affect HMEC-1 proliferation in FBS-free conditions. Duration of mitosis, cell motility and the cell death process were similar in all conditions. These data suggest that adiponectin and leptin exert different effects on endothelial cell function. Adiponectin was able to potentiate proliferation of HMEC-1. This effect involves the activation of both PI3-K/Akt and ERK/MAPK pathways. However, it seems to exert minimal effects on HMEC-1 function in the case of leptin, Fondo de Investigaciones Sanitarias, Mutua Madrileña, Red Cardiovascular del FIS, Depto. de Estadística e Investigación Operativa, Depto. de Inmunología, Oftalmología y ORL, Fac. de Ciencias Matemáticas, Fac. de Medicina, TRUE, pub

Objective Considering the increasing use of complexity estimates in neuropsychiatric populations, a normative study is critical to define the ‘normal’ behaviour of brain oscillatory complexity across the life span. Method This study examines changes in resting-state magnetoencephalogram (MEG) complexity – quantified with the Lempel–Ziv complexity (LZC) algorithm – due to age and gender in a large sample of 222 (100 males/122 females) healthy participants with ages ranging from 7 to 84 years. Results A significant quadratic (curvilinear) relationship (p < 0.05) between age and complexity was found, with LZC maxima being reached by the sixth decade of life. Once that peak was crossed, complexity values slowly decreased until late senescence. Females exhibited higher LZC values than males, with significant differences in the anterior, central and posterior regions (p < 0.05). Conclusions These results suggest that the evolution of brain oscillatory complexity across the life span might be considered a new illustration of a ‘normal’ physiological rhythm. Significance Previous and forthcoming clinical studies using complexity estimates might be interpreted from a more complete and dynamical perspective. Pathologies not only cause an ‘abnormal’ increase or decrease of complexity values but they actually ‘break’ the ‘normal’ pattern of oscillatory complexity evolution as a function of age.

Temporal variations in the frequency of multiple maternities in many Western European countries have been described. However, within a single country, regional differences are observed. Urban industrialized regions and rural agricultural areas have experienced in recent decades a distinct decline in multiple deliveries, which in cases have been related to maternal age and parity changes. Research on multiple deliveries in Spain is scarce and none of the studies go back to the beginning of the 20th century or consider regional variation over an extended period of time. The present paper is a yearly study on multiple deliveries in Spain since 1900 including a geographical analysis. Rather than dealing with recent changes in multi-parity, this paper is concerned with Spain's long-term national variation (between 1900 and 2006). The changing pattern of double and triple deliveries was analyzed using data from the Spanish National Statistics Institute (INE). Twinning rates in Spain are low in comparison to those of equivalent periods in other countries, and the minimum rates correspond to the 1980s decade. Results were interpreted by taking into account the influence of age at maternity and reproductive variation up to 1990. A good fit between observed and predicted rates was obtained after the application of models, which besides maternal age and parity, include their interaction. Regarding territorial variability, the values corresponding to southern, northern and insular Spanish provinces are consistent with an earlier reduction of the crude birth rate in the northeast regions and latter in the southern regions and the Canary Islands., e Spanish Ministry of Science and Innovation, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

The mating pattern in a population determines the next generation gene pool and therefore its genetic structure. Besides socio-cultural and geographic factors, political barriers may influence the formation of couples. The present paper studies how the change of national border affected the mating pattern of Olivenza in Badajoz Province (Spain), which experienced a change of domain from Portugal to Spain in 1801. For the period analysed (17501850), 954 Catholic marriage records were transcribed. Data were sorted by decades in order to make a temporal study possible and analysed by means of diversity and repeated-pairs of surnames. Following the change of border the mating pattern modified. Coinciding with a larger number of mixed marriages with Spaniards, there was a progressive rise in the diversity of surnames. From 1811 to 1820 the analysis of repeated-pairs of surnames indicates the existence of preferential matings within Spanish and Portuguese lineages. After 1821 the above pattern became less clear due to the disappearance of the SpanishPortuguese restrictions on choice of mate., Ministerio de Educación y Ciencia, Depto. de Biodiversidad, Ecología y Evolución, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Biológicas, Fac. de Ciencias Matemáticas, TRUE, pub

Published online in Wiley InterScience (www.interscience.wiley.com), The transport of peptides to the endoplasmic reticulum by the transporter associated with antigen processing (TAP) is a necessary step towards determining CD8 T cell epitopes. In this work, we have studied the predictive performance of support vector machine models trained on single residue positions and residue combinations drawn from a large dataset consisting of 613 nonamer peptides of known affinity to TAP. Predictive performance of these TAP affinity models was evaluated under 10-fold cross-validation experiments and measured using Pearson's correlation coefficients (R(p)). Our results show that every peptide position (P1-P9) contributes to TAP binding (minimum R(p) of 0.26 +/- 0.11 was achieved by a model trained on the P6 residue), although the largest contributions to binding correspond to the C-terminal end (R(p) = 0.68 +/- 0.06) and the P1 (R(p) = 0.51 +/- 0.09) and P2 (0.57 +/- 0.08) residues of the peptide. Training the models on additional peptide residues generally improved their predictive performance and a maximum correlation (R(p) = 0.89 +/- 0.03) was achieved by a model trained on the full-length sequences or a residue selection consisting of the first 5 N- and last 3 C-terminal residues of the peptides included in the training set. A system for predicting the binding affinity of peptides to TAP using the methods described here is readily available for free public use at http://imed.med.ucm.es/Tools/tapreg/., Ministerio de Ciencia e Innovación (MICINN), Universidad Complutense de Madrid, Depto. de Inmunología, Oftalmología y ORL, Fac. de Medicina, TRUE, pub

Background: Attention-deficit/hyperactivity disorder (ADHD) is defined as the most common neurobehavioral disorder of childhood, but an objective diagnostic test is not available yet to date. Neurophychological, neuroimaging, and neurophysiological research offer ample evidence of brain and behavioral dysfunctions in ADHD, but these findings have not been useful as a diagnostic test. Methods: Whole-head magnetoencephalographic recordings were obtained from 14 diagnosed ADHD patients and 14 healthy children during resting conditions. Lempel-Ziv complexity (LZC) values were obtained for each channel and child and averaged in five sensor groups: anterior, central, left lateral, right lateral, and posterior. Results: Lempel-Ziv complexity scores were significantly higher in control subjects, with the maximum value in anterior region. Combining age and anterior complexity values allowed the correct classification of ADHD patients and control subjects with a 93% sensitivity and 79% specificity. Control subjects showed an age-related monotonic increase of LZC scores in all sensor groups, while children with ADHD exhibited a nonsignificant tendency toward decreased LZC scores. The age-related divergence resulted in a 100% specificity in children older than 9 years. Conclusions: Results support the role of a frontal hypoactivity in the diagnosis of ADHD. Moreover, the age-related divergence of complexity scores between ADHD patients and control subjects might reflect distinctive developmental trajectories. This interpretation of our results is in agreement with recent investigations reporting a delay of cortical maturation in the prefrontal cortex, Depto. de Estadística e Investigación Operativa, Depto. de Medicina Legal, Psiquiatría y Patología, Fac. de Ciencias Matemáticas, Fac. de Medicina, TRUE, pub

Aged mammals frequently exhibit a bilateral, progressive, and symmetric deafness related to the degeneration of auditory receptor. However, little is still known about aging effects on synapses in this receptor. Synaptophysin (Syp) is a 38 kDa Ca2+ binding glycoprotein widely found in presynaptic membrane and vesicles. The Syp has been found in presynaptic buttons of efferent auditory fibers, within the developing and adult auditory receptor. The detection of Syp in aged cochleae could provide relevant information about synaptic changes and receptor degeneration process observed in old animals. This paper focuses on aging linked changes related to the presence of Syp in cochleae of C57BL/6J mice (from 1 to 24 months old). Results showed that during the first months of age, no significant changes were observed in the Syp distribution under the basal pole of inner (IHCs) neither the outer (OHCs) hair cells. At six months of age, a significant decrease of Syp immunocytochemical detection appeared in fibers under the most external row of OHCs, but restricted to the cochlear basal coil. Only a very scarce reduction of Syp was noted under the IHC and the other OHC rows, also at the basal coil. From mice 9 months old on, a progressive decrease of the presence of Syp was found under IHC and all OHC rows starting at the basal coil and reaching the apical coil in the oldest mice. All these data could indicate that the cochlea aging process early affects to presynaptic membrane proteins of efferent endings fibers. This early alteration of cochleae efferent synapses could be involved in the whole degeneration of the Corti's organ., Depto. de Estadística e Investigación Operativa, Depto. de Inmunología, Oftalmología y ORL, Fac. de Ciencias Matemáticas, Fac. de Medicina, TRUE, pub

The increased incidence of multiple deliveries in Spain, in addition to changes in age at maternity and parity, is attributed to assisted reproductive treatments, but the relative contribution of the latter to this rise remains uncertain, due to the scarce information provided by clinics practicing those treatments. Population based data (1984-2004), including information on mother's age, nationality, marital status, date of delivery, and the characteristics of each (parity, single or multiple), and sex of newborns were provided by the Spanish Institute of Statistics. Twinning and triplet deliveries relate to maternal age, parity, and nationality. For younger ages (≤ 19, 20-24, 25-29) rates remained constant over time, but for older women (30-34, 35-39, ≥ 40) rates increased after 1994. From 1984 to 2004 the percentage of twins of opposite sex increased from 24.31 to 36.58 per cent. Since 1997, Spanish and non-Spanish mothers differentiate with respect to multiple maternity at ages over 30. In addition to unmarried Spanish women, immigrants constitute a reliable reference group that determines the convenience of segregating information on multiple deliveries respecting origin. The proportion of twins and triplets of opposite sex, maternal age, and parity patterns observed are concordant with a differential access to reproductive treatments depending on the woman's age. The present norm regulating the maximum number of fertilizations per cycle and the demand for these treatments explain the high incidence of multiple deliveries in Spain. A modified logistic curve predicts a stabilization of multiple deliveries, which will probably continue to be high in Spain., Depto. de Biodiversidad, Ecología y Evolución, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Biológicas, Fac. de Ciencias Matemáticas, TRUE, pub

Recently, some papers have been appearing that have noticed some mistakes in the calculations in the statistical software in simple and classical tests (Wilcoxon-Mann-Whitney and Log-Rank). This article examines the variance formulas for the Kendall test, the Jonckheere test, and the Terpstra test. We show in this article that these variances (in spite of what is said in the literature and in the statistical software), in the presence of ties and r3 groups, are only equal approximately and are exactly equal for two groups and ties as we prove in the Appendix., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Introduction: Very low birth weight (VLBW) infants, with a birth weight below 1500 g and a structurally immature lung, are at high risk for developing bronchopulmonary dysplasia. This risk is even higher if respiratory distress syndrome is present. Other acute lung diseases, such as air leak and pulmonary hemorrhage, can also be present. The aim of this study was to analyze the statistical relevance of several neonatal factors in the development of pulmonary complications in a sample of VLBW infants with respiratory distress syndrome. Patients and methods: A total of 209 VLBW infants with respiratory distress syndrome were studied. The variables analyzed were delivery date, respiratory distress syndrome grade, sex, birth weight, gestational age, referral (from within the hospital or elsewhere), prenatal corticosteroid administration, type of gestation, type of delivery, amniorrhexis time, Apgar test at 1 and 5 minutes, surfactant administration, hours of life at which the first dose of surfactant was administered, and early sepsis. A multiple logistic regression analysis was developed using Hosmer-Lemeshow methodology. Results: In the multivariate analysis, air leak was related to respiratory distress syndrome grade and surfactant administration. Pulmonary hemorrhage was related to lower birth weight and absence of prenatal corticosteroid administration. Bronchopulmonary dysplasia was related to single pregnancies, absence of prenatal corticosteroid administration, lower birth weight, lower Apgar score at 1 minute, and higher respiratory distress syndrome grade. Conclusions: Respiratory morbidity in VLBW infants with respiratory distress syndrome could be influenced by several interrelated intrinsic and extrinsic variables, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Objective: To test the hypothesis that there is increased low-frequency activity located predominantly in the frontal lobe in patients with major depressive disorder using magnetoencephalography. Methods: We carried out an unmatched or separate sampling case-control study of 31 medication-free patients who met the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), criteria for major depressive disorder and were outpatients of the Hospital Central de la Defensa, Madrid, and 22 healthy control subjects with no history of mental illness. A logistic regression analysis was employed to examine the predictive value of magnetoencephalography dipole density scores in the diagnosis of depression. We attempted to locate generators of focal magnetic slow waves by employing a single moving dipole model and by calculating dipole densities in prefrontal, frontal, parietal, temporal and occipital areas. The study lasted from February 2001 to January 2003. Results: Only 2 dipole density scores, right occipital delta and left temporal delta, were significantly related to depression. According to the comparison of univariate and multivariate models and odds ratios, the right occipital delta dipole density is the factor with the greatest predictive power for depression, and the only one to show a significant correlation with severity of depression. Conclusions: We did not find any frontal lobe functional alteration. Our study provides, to the best of our knowledge, the first evidence of abnormal focal magnetic low-frequency activity in the occipital lobe of untreated patients with depression. Increased occipital lobe delta dipole density seems to be a reliable risk factor for depression, which correlates with disease severity according to the Hamilton Rating Scale for Depression., Depto. de Estadística e Investigación Operativa, Depto. de Medicina Legal, Psiquiatría y Patología, Fac. de Ciencias Matemáticas, Fac. de Medicina, TRUE, pub

Introducción: La expectativa de vivir de los recién nacidos de muy bajo peso (RNMBP) ha mejorado en los últimos años. Cuando estos pacientes presentan, además, enfermedad de membrana hialina (EMH), es difícil conocer con seguridad cuáles son los factores que más influyen en su mortalidad. Este trabajo tiene el objetivo de averiguar, dentro de un conjunto de variables, las más influyentes en la mortalidad desde una perspectiva multifactorial. Pacientes y métodos: Se tomó una muestra de 209 RNMBP con EMH nacidos en un período amplio, 15 años y 7 meses. Se consideraron las variables: "fecha de parto", "grado de enfermedad de membrana hialina", "sexo", "peso al nacimiento", "semanas de gestación", "procedencia", "administración de corticoides prenatales", "tipo de gestación", "tipo de parto", "momento de la amniorrexis", "puntuación del test de Apgar al minuto y a los 5 min", "administración de surfactante", "horas de vida en la administración de la primera dosis de surfactante" y "sepsis precoz". Siguiendo la metodología de selección de variables de Hosmer-Lemeshow se realizó un análisis de regresión logística múltiple. Resultados: Resultaron significativas las variables peso al nacimiento; test de Apgar, 5; corticoides prenatales, grado de membrana hialina y tratamiento con agente tensioactivo, quedando la importancia del resto de las variables diluida en ellas. Conclusiones: El incremento de peso y el test de Apgar a los 5 min, la administración de agente tensioactivo y corticoides, así como un grado bajo de membrana hialina hacen que la mortalidad disminuya. El modelo de regresión logística encontrado cuantifica cómo actúan estos factores y permite estimar la probabilidad de fallecer para un nuevo RNMBP con EMH., Introduction: In the last few years the life expectancy of very low birth weight (VLBW) infants has improved. When these patients have respiratory distress syndrome, it is difficult to know with any certainty which factors have the greatest influence on mortality. The aim of this study was to determine which variables, among a series, have the greatest influence on mortality from a multivariate perspective. Patients and methods: A sample of 209 VLBW infants born over a long period (15 years and 7 months) was studied. The following variables were analyzed: date of birth, degree of respiratory distress syndrome, sex, birth weight, weeks of gestation, born within or elsewhere, prenatal corticoid administration, type of gestation, type of delivery, amniorrhexis time, Apgar test at 1 and 5 minutes, surfactant administration, hours of life at which the first dose of surfactant was administered, and early sepsis. A multiple logistic regression analysis was developed using Hosmer-Lemeshow methodology. Results: The following variables were identified as significant: birth weight, Apgar test at 5 minutes, prenatal corticoids, degree of respiratory distress syndrome, and surfactant administration. The remaining variables were less important in the multivariate analysis. Conclusions: Higher birth weight and Apgar score at 5 minutes, prenatal corticoid and surfactant administration, and a lower degree of respiratory distress syndrome reduce mortality. The logistic regression model used quantifies how these factors behave and allows the probability of mortality in VLBW infants with respiratory distress syndrome to be estimated., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

In this paper we will give the relationships of several Score tests and Weighted tests for right censoring data with other classical tests. Special care will be taken with the case of ties and with the kind of estimation of the variance used. After the description of ten tests, a comparative study will be made among them. Finally, an application with a real example will be included., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Objective. To design intrauterine growth curves and charts for twins, according to sex and weeks of gestation, and examine the perinatal aspects of these pregnancies. Material and methods. A cross-sectional, descriptive approach was employed to analyze the anthropometric data at birth (weight, length and head circumference) of 1116 pairs of healthy twins born of event-free pregnancies at Hospital San Carlos in Madrid, Spain. Results. The growth curves and charts of a total of 1056 twin boys and 1084 twin girls are presented according to means and standard deviations (+2SD, +1SD, -2SD, -1SD). Conclusion. Each population group should have their own fetal growth curves to enable the classification of newborns as preterm, full-term or post-term and as large, normal and small in size with regard to the gestational age., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Conventional visual analysis and dipole density analysis of magnetoencephalographic data for both spike and low-frequency magnetic activity were compared for presurgical evaluation in temporal lobe epilepsy (TLE) in a sample of 26 drug-resistant operated TLE patients. A series of logistic regression analyses were performed. Dipole density sensitivity was superior to visual localization analysis. Three separated logistic models were calculated for interictal spikes, low-frequency magnetic activity, and the combination of both measures. A combined interictal spike/low-frequency magnetic activity model predicted correctly the operated temporal lobe in all patients. Clear-cut criteria for the probability model are proposed that are valid for 92.3% of cases in the sample. The quantitative approach proposed by this study is an evidence-based model for presurgical evaluation of temporal lobe epilepsy, which improves previous magnetoencephalographic investigations and establishes working clinical criteria for patient evaluation in TLE., Depto. de Estadística e Investigación Operativa, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Ciencias Matemáticas, Fac. de Psicología, TRUE, pub

Objective: To compare fetal growth averaged rythm of single pregnancies with those of pregnancies of twins, according to sex and gestational duration time; and comparing twin male and female newborns. Material and method: Comparisons are taken from the averaged weekly growth of 1.056 male twins and 1.084 twin female newborns, against 19.982 single males and 18.636 single female newborns, respectively. These comparisons are also taken from the 1.056 male twins and the 1.084 female twins. Results: The significant differences between single newborns and twins according to weight averaged growth, seize and cranium perimeter start from the thirty-fourth gestational week. Once male and female twins are compared, significant differences appear in weight and in averaged seize since the thirty-fourth gestational week. However, when cranium perimeters are compared, significant differences don't exist. Conclusion: Each country must have their own fetal growth curves for clasifying newborns accurately., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

Objective: to elaborate twin intrauterine growth curves and standard graphics according to sex and gestational age and perinatology facts of these gestations. Material and methods: to study anthropometry at birth (weight, height and head circumference) of 1116 couples of twins born at Hospital Clínico San Carlos de Madrid. A transversal descriptive analysis has been used. Results: growth curves and graphics of 1056 healthy male twins and 1086 healthy female twins coming from non patology pregnancies with percentiled (3,10,25,50,75,90,97) are shown. Conclusions: each population group must have their own fetal growth curves so we can clasify newborns in preterm, in term and post-term and in big, normal and small acording to gestational age., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

In this paper we give the generalization of the score tests covering the case of ties and we give examples where the expressions in matrix form are completely specified for the weighted tests and the score tests for the case of r groups. It is worth mentioning that although the score tests are not generally included in the commercial software, these tests should be used if it can be assumed that the censoring mechanism is equal in the r groups or if there is no censoring (Lawless, 1982). We establish the equivalence between "numerators" of these families of tests. As result of this equivalence we define four new tests that complete the classification of score and weighted tests. The Kruskal-Wallis test (1952) appears as a particular case of the score tests for the case of non-censoring. A simulation study has been done in order to compare the performance of the tests described in this paper. An example is included to make the understanding of the paper easier., Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

The performance of students in speech intelligibility tests is influenced by individual characteristics such as sex and age, personality factors such as neuroticism (N), extraversion, attention and sensitivity to noise, and environmental conditions such as the location of the scholars in the classroom (LI), the location of the classroom itself with regard to extraneous noise (LO) and background noise (BN). The first aim of this study was to analyse the role of these factors in predicting performance. From a mathematical point of view the problem was to establish a model to reflect accurately the relationship between the expected proportion of successes and a set of covariates. We used a logistic regression model mainly because of its high mathematical flexibility. A further aim was to study in depth methodological questions such as the choice and assessment of the model, including its extension to a random-effects model. One hundred and seventy students participated in the study. The results indicate that only four of the factors studied had any significant bearing upon their performance: N, LI, BN and LO, and that the effect of the classroom on performance was a random one. The covariate pattern corresponding to the best performance is given by the following levels : (N) high, (LI) front row, (LO) playground and (BN) normal. For this pattern the estimated proportion of successes is 0.66, Depto. de Estadística e Investigación Operativa, Fac. de Ciencias Matemáticas, TRUE, pub

En el presente proyecto hemos preparado material docente y propuesto una actividad para los alumnos, ambos en formato vídeo. Tras ello, a través de una encuesta a los estudiantes participantes, hemos analizado su idoneidad como estrategias para el aprendizaje de la Genética en Medicina, identificando sus puntos fuertes y débiles.

En el presente proyecto hemos preparado material docente y propuesto una actividad para los alumnos, ambos en formato vídeo. Tras ello, a través de una encuesta a los estudiantes participantes, hemos analizado su idoneidad como estrategias para el aprendizaje de la Genética en Medicina, identificando sus puntos fuertes y débiles., In this project we have prepared didactic material and proposed an activity for the students, both in video. Subsequently, through a survey of the participating students, we have analyzed their suitability as strategies for learning Medical Genetics, identifying their strengths and weaknesses.