Methadone maintenance treatment in the Swiss Canton of Vaud: demographic and clinical data on 1,782 ambulatory patients.

Using data from the Public Health Service, we studied the demographic and clinical characteristics of 1,782 patients enrolled in methadone maintenance treatment (MMT) during 2001 in the Swiss Canton of Vaud, comparing our findings with the results of a previous study from 1976 to 1986. In 2001, most patients (76.9%) were treated in general practice. Mortality is low in this MMT population (1%/year). While patient age and sex profiles were similar to those found in the earlier study, we did observe a substantial increase in the number of patients and the number of practitioners treating MMT patients, probably reflecting the low-threshold governmental policies and the creation of specialized centers. In conclusion, easier access to MMT enhances the number of patients, but new concerns about the quality of management emerge: benzodiazepine as a concomitant prescription; low rates of screening for hepatitis B, C and HIV, and social and psychiatric preoccupations.

Compliance with medication among outpatients with uncontrolled hypertension in the Seychelles.

Owing to increasing rates of hypertension and cardiovascular-related diseases in developing countries, compliance with antihypertensive medication is major public health importance. Few studies have reported on compliance in developing countries. We determined the compliance of 187 patients with uncontrolled hypertension in the Seychelles (Indian Ocean), by assessing the presence of a biologic marker (riboflavin) in the urine. The urine tested positive in 56% of the cases. Compliance varied from one physician to another (highest 72% versus lowest 33%, P = 0.003), improved with the level of literacy (62% versus 45%, P = 0.024), and depended on the presence absence of diuretics in the medication (respectively, 45% versus 66%, P = 0.005). The ability of patients to report correctly the number of antihypertensive pills to be taken daily was a predictor of compliance (62% of the patients who gave appropriate answers had positive urine for the marker versus 31% for those giving inappropriate answers).

Demogenetics in metapopulations

SUMMARY : Human-induced habitat fragmentation constitutes a major threat to biodiversity. Small and isolated populations suffer from increased stochasticity and from limited rescue effects. These two factors may be sufficient to cause local extinctions but fragmentation induces some genetic consequences that can also contribute significantly to extinction risks. Increased genetic drift reduces the effectiveness of selection against deleterious mutations, leading to their progressive accumulation. Drift also decreases both the standing genetic variation and the rate of fixation of beneficial mutations, limiting the evolutionary potential of isolated populations. Demography and genetics further interact and feed back on each other, progressively driving fragmented populations into "extinction vortices". The aim of the thesis was to better understand the processes occurring in fragmented populations. For this, I combined simulation studies and empirical data from three species that live in structured habitats. Chapter 1 and 2 investigate the demography of two shrew species in fragmented habitats. I showed that connectivity and habitat quality strongly affect the demography of the greater white-tooted shrew, although demographic stochasticity was extremely high. I also demonstrated that habitat fragmentation is one of the leading factors allowing the local coexistence of two competing shrew species. Chapter 3 and 4 focus on measuring connectivity in fragmented populations based on genetic data. In particular, I showed that genetic data can be used to detect the landscape elements impeding dispersal. In Chapter 5 that deals with the accumulation of deleterious mutations in fragmented populations, I demonstrated that mutation accumulation, as well a time to extinction, can be predicted from simple demographic and genetic measures. In the last two chapters, I monitored individual reproductive success in an isolated tree frogs population. These data allowed quantifying the effective population size, a measure closely linked to population evolutionary potential. To conclude, this thesis brings some new insights into the processes occurring in fragmented populations, and I hope it will contribute to the improvement of the management and conservation of fragmented populations.

How a haemosporidian parasite of bats gets around: the genetic structure of a parasite, vector and host compared.

Parasite population structure is often thought to be largely shaped by that of its host. In the case of a parasite with a complex life cycle, two host species, each with their own patterns of demography and migration, spread the parasite. However, the population structure of the parasite is predicted to resemble only that of the most vagile host species. In this study, we tested this prediction in the context of a vector-transmitted parasite. We sampled the haemosporidian parasite Polychromophilus melanipherus across its European range, together with its bat fly vector Nycteribia schmidlii and its host, the bent-winged bat Miniopterus schreibersii. Based on microsatellite analyses, the wingless vector, and not the bat host, was identified as the least structured population and should therefore be considered the most vagile host. Genetic distance matrices were compared for all three species based on a mitochondrial DNA fragment. Both host and vector populations followed an isolation-by-distance pattern across the Mediterranean, but not the parasite. Mantel tests found no correlation between the parasite and either the host or vector populations. We therefore found no support for our hypothesis; the parasite population structure matched neither vector nor host. Instead, we propose a model where the parasite's gene flow is represented by the added effects of host and vector dispersal patterns.

Linking landscape- and population ecology for large population management modelling: the case of Ibex (capra ibex) in Switzerland

La biologie de la conservation est communément associée à la protection de petites populations menacées d?extinction. Pourtant, il peut également être nécessaire de soumettre à gestion des populations surabondantes ou susceptibles d?une trop grande expansion, dans le but de prévenir les effets néfastes de la surpopulation. Du fait des différences tant quantitatives que qualitatives entre protection des petites populations et contrôle des grandes, il est nécessaire de disposer de modèles et de méthodes distinctes. L?objectif de ce travail a été de développer des modèles prédictifs de la dynamique des grandes populations, ainsi que des logiciels permettant de calculer les paramètres de ces modèles et de tester des scénarios de gestion. Le cas du Bouquetin des Alpes (Capra ibex ibex) - en forte expansion en Suisse depuis sa réintroduction au début du XXème siècle - servit d?exemple. Cette tâche fut accomplie en trois étapes : En premier lieu, un modèle de dynamique locale, spécifique au Bouquetin, fut développé : le modèle sous-jacent - structuré en classes d?âge et de sexe - est basé sur une matrice de Leslie à laquelle ont été ajoutées la densité-dépendance, la stochasticité environnementale et la chasse de régulation. Ce modèle fut implémenté dans un logiciel d?aide à la gestion - nommé SIM-Ibex - permettant la maintenance de données de recensements, l?estimation automatisée des paramètres, ainsi que l?ajustement et la simulation de stratégies de régulation. Mais la dynamique d?une population est influencée non seulement par des facteurs démographiques, mais aussi par la dispersion et la colonisation de nouveaux espaces. Il est donc nécessaire de pouvoir modéliser tant la qualité de l?habitat que les obstacles à la dispersion. Une collection de logiciels - nommée Biomapper - fut donc développée. Son module central est basé sur l?Analyse Factorielle de la Niche Ecologique (ENFA) dont le principe est de calculer des facteurs de marginalité et de spécialisation de la niche écologique à partir de prédicteurs environnementaux et de données d?observation de l?espèce. Tous les modules de Biomapper sont liés aux Systèmes d?Information Géographiques (SIG) ; ils couvrent toutes les opérations d?importation des données, préparation des prédicteurs, ENFA et calcul de la carte de qualité d?habitat, validation et traitement des résultats ; un module permet également de cartographier les barrières et les corridors de dispersion. Le domaine d?application de l?ENFA fut exploré par le biais d?une distribution d?espèce virtuelle. La comparaison à une méthode couramment utilisée pour construire des cartes de qualité d?habitat, le Modèle Linéaire Généralisé (GLM), montra qu?elle était particulièrement adaptée pour les espèces cryptiques ou en cours d?expansion. Les informations sur la démographie et le paysage furent finalement fusionnées en un modèle global. Une approche basée sur un automate cellulaire fut choisie, tant pour satisfaire aux contraintes du réalisme de la modélisation du paysage qu?à celles imposées par les grandes populations : la zone d?étude est modélisée par un pavage de cellules hexagonales, chacune caractérisée par des propriétés - une capacité de soutien et six taux d?imperméabilité quantifiant les échanges entre cellules adjacentes - et une variable, la densité de la population. Cette dernière varie en fonction de la reproduction et de la survie locale, ainsi que de la dispersion, sous l?influence de la densité-dépendance et de la stochasticité. Un logiciel - nommé HexaSpace - fut développé pour accomplir deux fonctions : 1° Calibrer l?automate sur la base de modèles de dynamique (par ex. calculés par SIM-Ibex) et d?une carte de qualité d?habitat (par ex. calculée par Biomapper). 2° Faire tourner des simulations. Il permet d?étudier l?expansion d?une espèce envahisseuse dans un paysage complexe composé de zones de qualité diverses et comportant des obstacles à la dispersion. Ce modèle fut appliqué à l?histoire de la réintroduction du Bouquetin dans les Alpes bernoises (Suisse). SIM-Ibex est actuellement utilisé par les gestionnaires de la faune et par les inspecteurs du gouvernement pour préparer et contrôler les plans de tir. Biomapper a été appliqué à plusieurs espèces (tant végétales qu?animales) à travers le Monde. De même, même si HexaSpace fut initialement conçu pour des espèces animales terrestres, il pourrait aisément être étndu à la propagation de plantes ou à la dispersion d?animaux volants. Ces logiciels étant conçus pour, à partir de données brutes, construire un modèle réaliste complexe, et du fait qu?ils sont dotés d?une interface d?utilisation intuitive, ils sont susceptibles de nombreuses applications en biologie de la conservation. En outre, ces approches peuvent également s?appliquer à des questions théoriques dans les domaines de l?écologie des populations et du paysage.<br/><br/>Conservation biology is commonly associated to small and endangered population protection. Nevertheless, large or potentially large populations may also need human management to prevent negative effects of overpopulation. As there are both qualitative and quantitative differences between small population protection and large population controlling, distinct methods and models are needed. The aim of this work was to develop theoretical models to predict large population dynamics, as well as computer tools to assess the parameters of these models and to test management scenarios. The alpine Ibex (Capra ibex ibex) - which experienced a spectacular increase since its reintroduction in Switzerland at the beginning of the 20th century - was used as paradigm species. This task was achieved in three steps: A local population dynamics model was first developed specifically for Ibex: the underlying age- and sex-structured model is based on a Leslie matrix approach with addition of density-dependence, environmental stochasticity and culling. This model was implemented into a management-support software - named SIM-Ibex - allowing census data maintenance, parameter automated assessment and culling strategies tuning and simulating. However population dynamics is driven not only by demographic factors, but also by dispersal and colonisation of new areas. Habitat suitability and obstacles modelling had therefore to be addressed. Thus, a software package - named Biomapper - was developed. Its central module is based on the Ecological Niche Factor Analysis (ENFA) whose principle is to compute niche marginality and specialisation factors from a set of environmental predictors and species presence data. All Biomapper modules are linked to Geographic Information Systems (GIS); they cover all operations of data importation, predictor preparation, ENFA and habitat suitability map computation, results validation and further processing; a module also allows mapping of dispersal barriers and corridors. ENFA application domain was then explored by means of a simulated species distribution. It was compared to a common habitat suitability assessing method, the Generalised Linear Model (GLM), and was proven better suited for spreading or cryptic species. Demography and landscape informations were finally merged into a global model. To cope with landscape realism and technical constraints of large population modelling, a cellular automaton approach was chosen: the study area is modelled by a lattice of hexagonal cells, each one characterised by a few fixed properties - a carrying capacity and six impermeability rates quantifying exchanges between adjacent cells - and one variable, population density. The later varies according to local reproduction/survival and dispersal dynamics, modified by density-dependence and stochasticity. A software - named HexaSpace - was developed, which achieves two functions: 1° Calibrating the automaton on the base of local population dynamics models (e.g., computed by SIM-Ibex) and a habitat suitability map (e.g. computed by Biomapper). 2° Running simulations. It allows studying the spreading of an invading species across a complex landscape made of variously suitable areas and dispersal barriers. This model was applied to the history of Ibex reintroduction in Bernese Alps (Switzerland). SIM-Ibex is now used by governmental wildlife managers to prepare and verify culling plans. Biomapper has been applied to several species (both plants and animals) all around the World. In the same way, whilst HexaSpace was originally designed for terrestrial animal species, it could be easily extended to model plant propagation or flying animals dispersal. As these softwares were designed to proceed from low-level data to build a complex realistic model and as they benefit from an intuitive user-interface, they may have many conservation applications. Moreover, theoretical questions in the fields of population and landscape ecology might also be addressed by these approaches.

Interviewer and Respondent Survey Quality Effects in a CATI Panel

Especially in panel surveys, respondent attrition, respondent learning, and interviewer experience effects play a crucial role with respect to data quality. We examine three interview survey quality indicators in the same survey in a cross sectional as well as in a longitudinal way. In the cross sectional analysis we compare data quality in the mature original sample with that in a refreshment sample, surveyed in the same wave. Because in the same wave an interviewer survey was conducted, collecting attitudes on their socio demography, survey attitudes and burden measures, we are able to consider interviewer fixed effects as well. The longitudinal analysis gives more insight in the respondent learning effects with respect to the quality indicators considered by considering the very same respondents across waves. The Swiss Household Panel, a CATI survey representative of the Swiss residential population, forms an ideal modelling database: the interviewer - respondent assignment is random, both within and across waves. This design avoids possible confusion with other effects stemming from a non-random assignment of interviewers, e.g. area effects or effects from assigning the best interviewers to the hard cases. In order to separate interviewer, respondent and wave effects, we build cross-classified multilevel models.

Cambios y permanencias en las dinámicas sociodemográficas de los Pirineos españoles. El papel de los movimientos migratorios

En este trabajo pretendemos ofrecer una visión de conjunto de la demografía de los municipios y comarcas que conforman el espacio que convencionalmente definimos como los Pirineos. Un territorio que, con mayor o menor intensidad según las coyunturas, ha vislumbrado cómo sus efectivos poblacionales han ido disminuyendo dramáticamente a lo largo de todo el siglo XX. Sin embargo, en la última década y en estos primeros años de la nueva centuria, se están detectando cambios en sus negativas dinámicas demográficas, que reflejan a su vez modificaciones de las funciones socioeconómicas que una parte de los municipios pirenaicos desempeñan en la sociedad española. Los motores que vehiculan estas nuevas tendencias son, principalmente, la combinación de las funciones turística y residencial que ahora van a desarrollar una parte de estos municipios.

The effects of unemployment benefits on migration in lagging regions

[spa] En este trabajo se analizan los efectos sobre la movilidad geográfica de una política pública (SIPTEA) que aumenta la protección por desempleo en Extremadura y Andalucía. Utilizando la discontinuidad geográfica en la política estudiada y datos de los Censos de Población de 1981 y 1991 a nivel municipal, se estima el efecto de SIPTEA en el crecimiento de la población y en las probabilidades de emigrar e inmigrar en áreas rurales que experimentan elevadas tasas de paro y de emigración. Los resultados del trabajo indican que la política mitigó estas pérdidas de población aunque los efectos son cuantitativamente moderados. También se exploran los efectos de dicha política en el ámbito laboral, encontrándose un incremento de la tasa del desempleo asociado a la implementación de la política de entre 10 y 13 puntos porcentuales.

The effects of unemployment benefits on migration in lagging regions

[spa] En este trabajo se analizan los efectos sobre la movilidad geográfica de una política pública (SIPTEA) que aumenta la protección por desempleo en Extremadura y Andalucía. Utilizando la discontinuidad geográfica en la política estudiada y datos de los Censos de Población de 1981 y 1991 a nivel municipal, se estima el efecto de SIPTEA en el crecimiento de la población y en las probabilidades de emigrar e inmigrar en áreas rurales que experimentan elevadas tasas de paro y de emigración. Los resultados del trabajo indican que la política mitigó estas pérdidas de población aunque los efectos son cuantitativamente moderados. También se exploran los efectos de dicha política en el ámbito laboral, encontrándose un incremento de la tasa del desempleo asociado a la implementación de la política de entre 10 y 13 puntos porcentuales.

Reconstruction of the Regional GDP of Portugal, 1890 – 1980

[cat] Aquest article metodològic ofereix estimacions del PIB per càpita regional de les regions portugueses, entre 1890 i 1980. Aquestes estimacions s’han obtingut seguint la metodologia proposada per (Geary and Stark, 2002) per a la industria, i considerant estimacions de producció directa per la resta de sectors.

Reconstruction of the Regional GDP of Portugal, 1890 – 1980

[cat] Aquest article metodològic ofereix estimacions del PIB per càpita regional de les regions portugueses, entre 1890 i 1980. Aquestes estimacions s’han obtingut seguint la metodologia proposada per (Geary and Stark, 2002) per a la industria, i considerant estimacions de producció directa per la resta de sectors.

Nuevas series anuales de población de América Latina desde el siglo XIX hasta el 2000

El estudio de la población en América Latina es un tema central en la historiografía de la región, sin embargo, las distintas estimaciones existentes muestran importantes discrepancias para los siglos XIX y XX. A partir del contraste de distintas bases de datos, la principal contribución del artículo consiste en ofrecer nuevas series de población homogéneas para el conjunto de países de América Latina, junto a una detallada explicación de la obtención de los datos, así como un análisis de las discrepancias que las distintas fuentes muestran. Los países que aborda este trabajo son Argentina, Brasil, Bolivia, Chile, Colombia, Costa Rica, Cuba, Guatemala, Ecuador, Haití, Honduras, México, Nicaragua, Panamá, Paraguay, Perú, República Dominicana, Uruguay y Venezuela; a lo que se agrega la suma de todos ellos para obtener la población latinoamericana. Estas nuevas series pueden resultar de gran utilidad para reinterpretar la historia económica de América Latina en el largo plazo. The analysis of population levels in Latin America plays an important role in the regional historiography. The estimated series appeared until now offers huge discrepancies, therefore, we believe essential to provide homogeneous series for the 19th and the 20th centuries. In our work we shed new light on this issue, from an exhaustive study of the existing Latin American historical sources for the region. Along with a detailed explanation of the data collection, we also provide an analysis of the discrepancies and the accuracy of sources. The study offers data from 21 countries in Latin America: Argentina, Brazil, Bolivia, Chile, Colombia, Costa Rica, Cuba, Guatemala, Ecuador, Haiti, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Dominican Republic, Uruguay and Venezuela. This new evidence can be a crucial information to revisit Latin American Economic History in the long run.

L'increment demogrà fic afecte la salut genètica

Un estudi publicat a 'Science' demostra que l'augment exponencial de la població del planeta també té conseqüències mèdiques, ja que fa créixer el risc de patir malalties rares

Landscape Systems and Human Land-Use Interactions in Mediterranean Highlands and Littoral Plains during the Late Holocene: Integrated Analysis from the InterAmbAr Project (North-Eastern Catalonia).

The main goal of the InterAmbAr reseach project is to analyze the relationships between landscape systems and human land-use strategies on mountains and littoral plains from a long-term perspective. The study adopts a high resolution analysis of small-scale study areas located in the Mediterranean region of north-eastern Catalonia. The study areas are distributed along an altitudinal transect from the high mountain (above 2000m a.s.l.) to the littoral plain of Empordà (Fig. 1). High resolution interdisciplinary research has been carried out from 2010, based on the integration of palaeoenvironmental and archaeological data. The micro-scale approach is used to understand human-environmental relationships. It allows better understanding of the local-regional nature of environmental changes and the synergies between catchment-based systems, hydro-sedimentary regimes, human mobility, land-uses, human environments, demography, etc.