Insular giant leporid matured later than predicted by scaling.

The island syndrome describes morphological, behavioral, and life history traits that evolve in parallel in endemic insular organisms. A basic axiom of the island syndrome is that insular endemics slow down their pace of life. Although this is already confirmed for insular dwarfs, a slow life history in giants may not be adaptive, but merely a consequence of increasing body size. We tested this question in the fossil insular giant leporid Nuralagus rex. Using bone histology, we constructed both a continental extant taxon model derived from experimentally fluorochrome-labeled Lepus europaeus to calibrate life history events, and a growth model for the insular taxon. N. rex grew extremely slowly and delayed maturity well beyond predictions from continental phylogenetically corrected scaling models. Our results support the life history axiom of the island syndrome as generality for insular mammals, regardless of whether they have evolved into dwarfs or giants.

Palaeohistology reveals a slow pace of life for the dwarfed Sicilian elephant.

The 1-m-tall dwarf elephant Palaeoloxodon falconeri from the Pleistocene of Sicily (Italy) is an extreme example of insular dwarfism and epitomizes the Island Rule. Based on scaling of life-history (LH) traits with body mass, P. falconeri is widely considered to be 'r-selected' by truncation of the growth period, associated with an early onset of reproduction and an abbreviated lifespan. These conjectures are, however, at odds with predictions from LH models for adaptive shifts in body size on islands. To settle the LH strategy of P. falconeri, we used bone, molar, and tusk histology to infer growth rates, age at first reproduction, and longevity. Our results from all approaches are congruent and provide evidence that the insular dwarf elephant grew at very slow rates over an extended period; attained maturity at the age of 15 years; and had a minimum lifespan of 68 years. This surpasses not only the values predicted from body mass but even those of both its giant sister taxon (P. antiquus) and its large mainland cousin (L. africana). The suite of LH traits of P. falconeri is consistent with the LH data hitherto inferred for other dwarfed insular mammals. P. falconeri, thus, not only epitomizes the Island Rule but it can also be viewed as a paradigm of evolutionary change towards a slow LH that accompanies the process of dwarfing in insular mammals.

Publisher Correction: Bone histology provides insights into the life history mechanisms underlying dwarfing in hipparionins.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

The Role of Religion and Religiosity in Alcohol Consumption in Adolescents in Spain.

This study explored the relationship between religion, religiosity and alcohol consumption in a sample of 2.890 adolescents (ages 12-18) in Madrid, Spain. Results showed that non-believers were the group that consume and abuse alcohol the most, as opposed to Catholics. Besides, religiosity was related to a lower alcohol use. Therefore, religion and religiosity in Spanish adolescents appear to be related to a low alcohol use. This contribution may help to clarify the risk and protection factors for alcohol consumption by adolescents and contribute to strengthening the preventive actions.

Bone histology provides insights into the life history mechanisms underlying dwarfing in hipparionins.

Size shifts may be a by-product of alterations in life history traits driven by natural selection. Although this approach has been proposed for islands, it has not yet been explored in continental faunas. The trends towards size decrease experienced by some hipparionins constitute a good case study for the application of a life history framework to understand the size shifts on the continent. Here, we analysed bone microstructure to reconstruct the growth of some different-sized hipparionins from Greece and Spain. The two dwarfed lineages studied show different growth strategies. The Greek hipparions ceased growth early at a small size thus advancing maturity, whilst the slower-growing Spanish hipparion matured later at a small size. Based on predictive life history models, we suggest that high adult mortality was the likely selective force behind early maturity and associated size decrease in the Greek lineage. Conversely, we infer that resource limitation accompanied by high juvenile mortality triggered decrease in growth rate and a relative late maturity in the Spanish lineage. Our results provide evidence that different selective pressures can precipitate different changes in life history that lead to similar size shifts.

Limb bone histology records birth in mammals.

The annual cyclicality of cortical bone growth marks (BGMs) allows reconstruction of some important life history traits, such as longevity, growth rate or age at maturity. Little attention has been paid, however, to non-cyclical BGMs, though some record key life history events such as hatching (egg-laying vertebrates), metamorphosis (amphibians), or weaning (suggested for Microcebus and the hedgehog). Here, we investigate the relationship between non-cyclical BGMs and a stressful biological event in mammals: the moment of birth. In the present study, we histologically examine ontogenetic series of femora, tibiae and metapodia in several extant representatives of the genus Equus (E. hemionus, E. quagga and E. grevyi). Our analysis reveals the presence of a non-cyclical growth mark that is deposited around the moment of birth, analogous to the neonatal line described for teeth. We therefore refer to it as neonatal line. The presence of this feature within the bone cross-section agrees with a period of growth arrest in newborn foals regulated by the endocrine system. The neonatal line is accompanied by modifications in bone tissue type and vascularization, and has been identified in all bones studied and at different ontogenetic ages. Our discovery of a non-cyclical BGM related to the moment of birth in mammals is an important step towards the histological reconstruction of life histories in extant and fossil equids.

Reconstructing molar growth from enamel histology in extant and extinct Equus.

The way teeth grow is recorded in dental enamel as incremental marks. Detailed analysis of tooth growth is known to provide valuable insights into the growth and the pace of life of vertebrates. Here, we study the growth pattern of the first lower molar in several extant and extinct species of Equus and explore its relationship with life history events. Our histological analysis shows that enamel extends beyond the molar's cervix in these mammals. We identified three different crown developmental stages (CDS) in the first lower molars of equids characterised by different growth rates and likely to be related to structural and ontogenetic modifications of the tooth. Enamel extension rate, which ranges from ≈400 µm/d at the beginning of crown development to rates of ≈30 µm/d near the root, and daily secretion rate (≈17 µm/d) have been shown to be very conservative within the genus. From our results, we also inferred data of molar wear rate for these equids that suggest higher wear rates at early ontogenetic stages (13 mm/y) than commonly assumed. The results obtained here provide a basis for future studies of equid dentition in different scientific areas, involving isotope, demographic and dietary studies.

Histological variability in the limb bones of the Asiatic wild ass and its significance for life history inferences.

The study of bone growth marks (BGMs) and other histological traits of bone tissue provides insights into the life history of present and past organisms. Important life history traits like longevity or age at maturity, which could be inferred from the analysis of these features, form the basis for estimations of demographic parameters that are essential in ecological and evolutionary studies of vertebrates. Here, we study the intraskeletal histological variability in an ontogenetic series of Asiatic wild ass (Equus hemionus) in order to assess the suitability of several skeletal elements to reconstruct the life history strategy of the species. Bone tissue types, vascular canal orientation and BGMs have been analyzed in 35 cross-sections of femur, tibia and metapodial bones of 9 individuals of different sexes, ages and habitats. Our results show that the number of BGMs recorded by the different limb bones varies within the same specimen. Our study supports that the femur is the most reliable bone for skeletochronology, as already suggested. Our findings also challenge traditional beliefs with regard to the meaning of deposition of the external fundamental system (EFS). In the Asiatic wild ass, this bone tissue is deposited some time after skeletal maturity and, in the case of the femora, coinciding with the reproductive maturity of the species. The results obtained from this research are not only relevant for future studies in fossil Equus, but could also contribute to improve the conservation strategies of threatened equid species.

Multidisciplinary characterization of the long-bone cortex growth patterns through sheep's ontogeny.

Bone researches have studied extant and extinct taxa extensively trying to disclose a complete view of the complex structural and chemical transformations that model and remodel the macro and microstructure of bone during growth. However, to approach bone growth variations is not an easy task, and many aspects related with histological transformations during ontogeny remain unresolved. In the present study, we conduct a holistic approach using different techniques (polarized microscopy, Raman spectroscopy and X-ray diffraction) to examine the histomorphological and histochemical variations in the cortical bone of sheep specimens from intrauterine to adult stages, using environmentally controlled specimens from the same species. Our results suggest that during sheep bone development, the most important morphological (shape and size) and chemical transformations in the cortical bone occur during the first weeks of life; synchronized but dissimilar variations are established in the forelimb and hind limb cortical bone; and the patterns of bone tissue maturation in both extremities are differentiated in the adult stage. All of these results indicate that standardized histological models are useful not only for evaluating many aspects of normal bone growth but also to understand other important influences on the bones, such as pathologies that remain unknown.

An approach to the histomorphological and histochemical variations of the humerus cortical bone through human ontogeny.

For many years, clinical and non-clinical investigations have investigated cortical bone structure in an attempt to address questions related to normal bone development, mineralisation, pathologies and even evolutionary trends in our lineage (adaptations). Research in the fields of medicine, materials science, physical anthropology, palaeontology, and even archaeobiology has contributed interesting data. However, many questions remain regarding the histomorphological and histochemical variations in human cortical bone during different stages of life. In the present work, we describe a study of long bone cortex transformations during ontogeny. We analysed cross-sections of 15 human humeri histomorphologically and histochemically from perinatal to adult age, marking and quantifying the spatial distribution of bone tissue types using GIS software and analysing the mineral composition and crystallinity of the mineralised cortex using Raman spectroscopy and X-ray diffraction. Our results allowed us to propose that human cortical bone undergoes three main 'events' through ontogeny that critically change the proportions and structure of the cortex. In early development, bone is not well mineralised and proportionally presents a wide cortex that narrows through the end of childhood. Before reaching complete maturity, the bone mineral area increases, allowing the bone to nearly reach the adult size. The medullary cavity is reduced, and the mineral areas have a highly ordered crystalline structure. The last event occurs in adulthood, when the 'oldest' individuals present a reduced mineralised area, with increasing non-mineralised cavities (including the medullary cavity) and reduced crystalline organisation.

¿Es necesaria una intervención diferencial de género en la prevención universal y selectiva del consumo de drogas en adolescentes? / Is a gender differential intervention necessary in the prevention of adolescent drug use?

Objetivos. Explorar los significados diferenciales en el consumo de drogas, tabaco y alcohol entre chicos y chicas, y plantear la posible necesidad de diseñar e implementar los programas de prevención desde una perspectiva de género. Métodos. Estudio cualitativo mediante 8 grupos de discusión con adolescentes de 14-18 años (n = 56) y 6 entrevistas semiestructuradas a expertos y profesionales de prevención de drogas en la Comunidad de Madrid. Análisis interpretativo categórico. Resultados. Los adolescentes y profesionales de prevención señalaban diferencias entre chicos y chicas en los consumos de tabaco y alcohol. Los significados, motivos asociados al consumo y las pautas de consumo eran percibidos de forma diferente en cada sexo. Adelgazar, calmar los nervios o una imagen de rebeldía era relacionada al fumar de las chicas mientras que el menor consumo de tabaco en los chicos se asociaba con su participación en el deporte. La percepción de cierta precocidad en los consumos de drogas se asociaba al paso del colegio al instituto. Constataban la buena imagen social asociada a fumar entre sus grupos. Los adolescentes manifestaron la ineficacia de las campañas y mensajes de prevención que recibían, la incoherencia de los adultos entres sus mensajes y acciones, y la atracción de todas las conductas que les eran prohibidas. Los profesionales observaban la necesidad de incluir la perspectiva de género en los programas de prevención, pero desconocían cómo concretarlo, ya que principalmente lo traducían en actividades diferentes para cada sexo. Conclusiones. Los diferentes significados asociados al consumo que otorgan chicos y chicas nos llevan a diseñar y realizar programas preventivos que incorporen la perspectiva de género, pues es quizá desde esta estrategia desde donde se pueda reducir el consumo de tabaco y alcohol entre las chicas (AU)

Objectives. To examine the significant differences in smoking, drug and alcohol use between adolescent boys and girls, and to raise the possible need to design and implement prevention programs from a gender perspective. Method. A qualitative study using eight discussion groups of adolescents aged 14-18 years (n = 56) and 6 semi-structured interviews with experts and professionals in drug prevention in the Community of Madrid. Categorical interpretive analysis was performed. Results. The adolescents and prevention professional indicated differences between boys and girls in drug and alcohol use. The significances, reasons associated with the consumption and the patterns of consumption were perceived differently by each sex. To lose weight, calm down or an image of rebelliousness was related to girls who smoked, while boys smoked less because they did more sports. The perception of certain precocity of drug consumption was associated with the step from school to Higher Education Institutions. They found smoking associated with a good social image among their groups. Adolescents showed the ineffectiveness of the campaigns and prevention messages they received, incoherence of adults between messages and actions, and the attraction of all behaviours that are banned. Professionals observed the need to include a gender perspective in prevention programs, but did not know how to achieve it, mainly because it has been translated into different activities for each sex until now. Conclusions. The significant differences associated with smoking, drug and alcohol use observed in the adolescents should lead us to design and implement prevention programs that incorporate a gender perspective. It is perhaps from this strategy where drug and alcohol use among girls can be reduced (AU)

Is a gender differential intervention necessary in the prevention of adolescent drug use?

OBJECTIVES: To examine the significant differences in smoking, drug and alcohol use between adolescent boys and girls, and to raise the possible need to design and implement prevention programs from a gender perspective. METHOD: A qualitative study using eight discussion groups of adolescents aged 14-18 years (n=56) and 6 semi-structured interviews with experts and professionals in drug prevention in the Community of Madrid. Categorical interpretive analysis was performed. RESULTS: The adolescents and prevention professional indicated differences between boys and girls in drug and alcohol use. The significances, reasons associated with the consumption and the patterns of consumption were perceived differently by each sex. To lose weight, calm down or an image of rebelliousness was related to girls who smoked, while boys smoked less because they did more sports. The perception of certain precocity of drug consumption was associated with the step from school to Higher Education Institutions. They found smoking associated with a good social image among their groups. Adolescents showed the ineffectiveness of the campaigns and prevention messages they received, incoherence of adults between messages and actions, and the attraction of all behaviours that are banned. Professionals observed the need to include a gender perspective in prevention programs, but did not know how to achieve it, mainly because it has been translated into different activities for each sex until now. CONCLUSIONS: The significant differences associated with smoking, drug and alcohol use observed in the adolescents should lead us to design and implement prevention programs that incorporate a gender perspective. It is perhaps from this strategy where drug and alcohol use among girls can be reduced.

Diferencias de género en el consumo diario de tabaco e intensivo de alcohol en adolescentes latinoamericanos en tres áreas españolas (Andalucía, Madrid y País Vasco) / Gender differences to daily smoking and binge drinking in the Latinoamerican Adolescents in three Spanish areas

El consumo diario de tabaco e intensivo de alcohol en la adolescencia puede configurarse como hábitos persistentes para la vida adulta. En este trabajo se pretende explorar las diferencias entre chicos y chicas adolescentes de origen latino con consumos intensivos de tabaco y alcohol, dado que son escasos los trabajos en España que introducen la variable cultural o étnica. Se trata de un estudio trasversal mediante encuesta escolar, a 1126 adolescentes de origen latino, escolarizados en la Educación Secundaria en tres zonas españolas, de 12 a 19 años. Entre los resultados destacamos que el 9,4% de los chicos y el 5,6% de las chicas latinas fumaban diariamente y el 24,2% de los chicos y el 19% de las chicas bebió cinco o más bebidas alcohólicas en el último evento. Fumar diariamente se asoció con ser chico, fumar el padre, fumar la pareja, actuando como factor de protección hacer deporte. Ser chico, emborracharse y haber ido de botellón aumenta la probabilidad de consumir alcohol de forma intensiva. Para concluir destacamos que existen diferencias de género en los consumos de tabaco y alcohol en el tipo de consumo intensivo pero no se aprecia cuando se trata del uso de estas sustancias. Se plantea la necesidad de tener en cuenta la variable de origen cultural en las intervenciones educativas sociosanitarias (AU)

The daily smoking and binge drinking in adolescence may produce persistent habit for adulthood. The objective of this research is to explore the differences between Latinoamerican girls and boys adolescents in the tobacco and alcohol consumes. The researches with cultural variable are scant in Spain. This study is transversal via a school survey comprising 1126 Latinoamerican adolescents, in Secondary Education in three areas and ranging from 12 to 19 years of age. The results are the 9,4% of the boys and the 5,6% of the girls smoke daily, and the 24,2% of the boys and the 19% of the girls for binge drinking the last event. The probability of daily smoking was associated to be a boy, to have a smoking father, to have a smoking couple and as protection factor was to do sport. So, to be a boy, to get drunk and have gone to Botellon increase the probability to binge drinking. The most important conclusion is that there were differences of gender in tobacco and alcohol abuse but not in the use. It is necessary to introduce the cultural variable in educative, health and social prevention (AU)

Mapping human long bone compartmentalisation during ontogeny: a new methodological approach.

Throughout ontogeny, human bones undergo differentiation in terms of shape, size and tissue type; this is a complex scenario in which the variations in the tissue compartmentalisation of the cortical bone are still poorly understood. Currently, compartmentalisation is studied using methodologies that oversimplify the bone tissue complexity. Here, we present a new methodological approach that integrates a histological description and a mineral content analysis to study the compartmentalisation of the whole mineralised and non-mineralised tissues (i.e., spatial distribution in long bone sections). This new methodology, based on Geographical Information System (GIS) software, allows us to draw areas of interest (i.e., tracing vectorial shapes which are quantifiable) in raw images that are extracted from microscope and compared them spatially in a semi-automatic and quantitative fashion. As an example of our methodology, we have studied the tibiae from individuals with different age at death (infant, juvenile and adult). The tibia's cortical bone presents a well-formed fibrolamellar bone, in which remodelling is clearly evidenced from early ontogeny, and we discuss the existence of "lines of arrested growth". Concurrent with the histological variation, Raman and FT-IR spectroscopy analyses corroborate that the mineral content in the cortical bone changes differentially. The anterior portion of the tibia remains highly pierced and is less crystalline than the rest of the cortex during growth, which is evidence of more active and continuous remodelling. Finally, while porosity and other "non-mineralised cavities" are largely modified, the mineralised portion and the marrow cavity size persist proportionally during ontogeny.

Factores motivacionales en una muestra de hombres españoles que pagan por servicios sexuales / Motivational factors in a sample of Spanish men who pay for sexual services

Los motivos para pagar por sexo fueron estudiados en una muestra de 138 clientes españoles mediante un cuestionario autoadministrado. Desde el análisis factorial se han identificado seis factores como razones para pagar servicios sexuales, que aglutinan el 80,4% de la varianza y que han sido etiquetados como Compañía, Necesidad, Distracción, Riesgo, Dominar y Rapidez. Cuatro de estos factores son significativos y explican, a través de un análisis de regresión, el número de veces que pagan por sexo: Compañía, Rapidez, Riesgo y Dominar. Algunas características de los clientes se relacionan con estos factores: la edad, edad del primer pago de servicios sexuales, la orientación sexual y el tipo de pareja en los últimos seis meses. Solo una de las prácticas sexuales, sexo anal insertito y receptivo, se relaciona con los factores motivacionales, en concreto con los factores Necesidad, Riesgo y Dominar (AU)

The reasons for paying for sex were studied in a sample of 138 Spanish clients by means of a self-administered questionnaire. Factor analysis made it possible to identify six factors as reasons for paying for sexual services. These factors account for 80.4% of variance and have been labeled Company, Need, Fun, Risk, Domination and Speed. Four of them are significant and explain, through a regression analysis, the number of times they pay for sex: these factors are Company Speed, Risk and Domination. Some of the characteristics of the clients are associated with these factors: current age, age at time of first encounter with a prostitute, sexual orientation and relationship history over the last six months. Only one of the sexual practices, insertive anal intercourse, is associated with the motivational factors, specifically with the factors Need, Risk and Domination (AU)

Mujeres y psicofármacos: la investigación en atención primaria / Women and psychotropics: the researching in the field of primary care

En este artículo se revisan algunos resultados obtenidos en investigaciones nacionales e internacionales realizadas sobre el uso de psicofármacos, especialmente de aquellos estudios sobre la prescripción y uso por las mujeres. Los resultados muestran que una parte importante de la producción científica se centra en el estudio de la detección de los trastornos en Atención Primaria o Especializada y en la morbilidad psiquiátrica de manera comparada entre los sexos. La mayor parte de las investigaciones realizadas en este ámbito tiene un carácter clínico y epidemiológico. Constituyen una excepción investigaciones realizadas en Estados Unidos o en el norte de Europa que buscan explicar los motivos y razones para un consumo y prescripción diferencial de psicofármacos, siendo las mujeres las principales afectadas. Se han analizado investigaciones que aportan información para poder responder a la pregunta: ¿Por qué las mujeres reciben los dos tercios de las prescripciones con psicofármacos? Vemos que las mujeres tienen mayor probabilidad que los varones de que les prescriban psicofármacos (AU)

This paper presents some of the results arising from an analysis of the researching performed -at both domestic and international levels- on the usage of psychotropic drugs, specially on their prescription and use by women. These results come to show that a significant part of the scientific production in this area focuses on studies about the detection of disorders in Primary or Specialized Care and about psychiatric morbidity, applying a comparative methodology between sexes. Much of the researching performed in this field has a clinical and epidemiologic nature. An exception to this trend come from some surveys performed in the USA and the North of Europe intended to clarify the causes and reasons that may explain the persisting differences in both prescription and use of such drugs, a situation that adversely impacts women. The surveys analyzed on this paper offer some information that may help us to find an answer to the question: Why are two thirds of the prescriptions involving psychotropics aimed to women? It is clear that women are more prone than men to be prescribed with such drugs (AU)