Biocontrol strain Pseudomonas fluorescens CHA0 and its genetically modified derivative with enhanced biocontrol capability exert comparable effects on the structure of a Sinorhizobium meliloti population in a gnotobiotic system

The impact of biocontrol strain Pseudomonas fluorescens CHA0 and of its genetically modified, antibiotic-overproducing derivative CHA0/pME3424 on a reconstructed population of the plant-beneficial Sinorhizobium meliloti bacteria was assessed in gnotobiotic systems. In sterile soil, the final density of the reconstructed S. meliloti population decreased by more than one order of magnitude in the presence of either of the Pseudomonas strains when compared to a control without addition of P. fluorescens. Moreover, there was a change in the proportion of each individual S. meliloti strain within the population. Plant tests also revealed changes in the nodulating S. meliloti population in the presence of strains CHA0 or CHA0/pME3424. In both treatments one S. meliloti strain, f43, was significantly reduced in its root nodule occupancy. Analysis of alfalfa yields showed a slight but statistically significant increase in shoot dry weight when strain CHA0 was added to the reconstructed S. meliloti population whereas no such effect was observed with CHA0/pME3424.

Patterns of sex work contact among men in the general population of Switzerland, 1987-2000

OBJECTIVES: To analyse the prevalence of lifetime recourse to prostitution (LRP) among men in the general population of Switzerland from a trend and cohort perspective. METHODS: Using nine repeated representative cross-sectional surveys from 1987 to 2000, age-specific estimates of LRP were computed. Trends and period effect were analysed as the evolution of cross-sectional population estimates within age groups and overall. Cohort analysis relied on cohorts constructed from the 1989 survey and followed in subsequent waves. Age and cohort effects were modelled using logistic regression and non-parametric monotone regression. RESULTS: Whereas prevalence for the younger groups was found to be logically lower, there was no consistent increasing or decreasing trend over the years; there was no significant period effect. For the 17-30 year age group, the mean estimate over 1987-2000 was 11.5% (range 8.3 to 12.7%); for the 31-45 year group, the mean was 21.5% (range over 1989-2000 20.3 to 23.0%). Regarding cohort analysis, the prevalence of LRP was found to increase steeply in the youngest ages before reaching a plateau near the age of 40 years. At the age of 43 years, the prevalence was estimated to be 22.6% (95% CI 21.1% to 24.1%). CONCLUSIONS: The steep increase in the cohort-wise prevalence of LRP in younger ages calls for a concentration of prevention activities in young people. If the plateauing at approximately 40 years of age is not followed by a further increase later in life, which is not known, then consumers of paid sex would be repeat buyers only, a fact that should be taken into account by prevention.

Paper 3: EUROCAT data quality indicators for population-based registries of congenital anomalies.

The European Surveillance of Congenital Anomalies (EUROCAT) network of population-based congenital anomaly registries is an important source of epidemiologic information on congenital anomalies in Europe covering live births, fetal deaths from 20 weeks gestation, and terminations of pregnancy for fetal anomaly. EUROCAT's policy is to strive for high-quality data, while ensuring consistency and transparency across all member registries. A set of 30 data quality indicators (DQIs) was developed to assess five key elements of data quality: completeness of case ascertainment, accuracy of diagnosis, completeness of information on EUROCAT variables, timeliness of data transmission, and availability of population denominator information. This article describes each of the individual DQIs and presents the output for each registry as well as the EUROCAT (unweighted) average, for 29 full member registries for 2004-2008. This information is also available on the EUROCAT website for previous years. The EUROCAT DQIs allow registries to evaluate their performance in relation to other registries and allows appropriate interpretations to be made of the data collected. The DQIs provide direction for improving data collection and ascertainment, and they allow annual assessment for monitoring continuous improvement. The DQI are constantly reviewed and refined to best document registry procedures and processes regarding data collection, to ensure appropriateness of DQI, and to ensure transparency so that the data collected can make a substantial and useful contribution to epidemiologic research on congenital anomalies.

Anti-basal ganglia antibodies and Tourette's syndrome: a voxel-based morphometry and diffusion tensor imaging study in an adult population.

Anti-basal ganglia antibodies (ABGAs) have been suggested to be a hallmark of autoimmunity in Gilles de la Tourette's syndrome (GTS), possibly related to prior exposure to streptococcal infection. In order to detect whether the presence of ABGAs was associated with subtle structural changes in GTS, whole-brain analysis using independent sets of T(1) and diffusion tensor imaging MRI-based methods were performed on 22 adults with GTS with (n = 9) and without (n = 13) detectable ABGAs in the serum. Voxel-based morphometry analysis failed to detect any significant difference in grey matter density between ABGA-positive and ABGA-negative groups in caudate nuclei, putamina, thalami and frontal lobes. These results suggest that ABGA synthesis is not related to structural changes in grey and white matter (detectable with these methods) within frontostriatal circuits.

Prospective evaluation of risk of vertebral fractures using quantitative ultrasound measurements and bone mineral density in a population-based sample of postmenopausal women: results of the Basel Osteoporosis Study.

OBJECTIVE: Prospective studies have shown that quantitative ultrasound (QUS) techniques predict the risk of fracture of the proximal femur with similar standardised risk ratios to dual-energy x-ray absorptiometry (DXA). Few studies have investigated these devices for the prediction of vertebral fractures. The Basel Osteoporosis Study (BOS) is a population-based prospective study to assess the performance of QUS devices and DXA in predicting incident vertebral fractures. METHODS: 432 women aged 60-80 years were followed-up for 3 years. Incident vertebral fractures were assessed radiologically. Bone measurements using DXA (spine and hip) and QUS measurements (calcaneus and proximal phalanges) were performed. Measurements were assessed for their value in predicting incident vertebral fractures using logistic regression. RESULTS: QUS measurements at the calcaneus and DXA measurements discriminated between women with and without incident vertebral fracture, (20% height reduction). The relative risks (RRs) for vertebral fracture, adjusted for age, were 2.3 for the Stiffness Index (SI) and 2.8 for the Quantitative Ultrasound Index (QUI) at the calcaneus and 2.0 for bone mineral density at the lumbar spine. The predictive value (AUC (95% CI)) of QUS measurements at the calcaneus remained highly significant (0.70 for SI, 0.72 for the QUI, and 0.67 for DXA at the lumbar spine) even after adjustment for other confounding variables. CONCLUSIONS: QUS of the calcaneus and bone mineral density measurements were shown to be significant predictors of incident vertebral fracture. The RRs for QUS measurements at the calcaneus are of similar magnitude as for DXA measurements.

Obésité en Suisse: percentiles d'indice de masse corporelle (IMC) d'une population d'enfants et d'adolescents nés en 1980 à Lausanne et écart avec les normes suisses (1955)

OBJECTIVES: The objective of this study is to calculate the percentiles of BMI of a cohort of 1,203 children and adolescents, representing the 95% of the pupils of the school, born in 1980 followed longitudinally between 5 and 16 years. We compare these percentiles with those of the first swiss study, calculated on a cohort born in 1954-1956. METHODS: The percentiles were calculated with the method of Cole, on the basis of weight and height measured during the controls by the school health service, at a non-periodic mean interval of 14 months. RESULTS: The gap between the BMI percentiles of the two cohorts is near zero for the third percentiles, weak but progressively growing with age up to two units of BMI for the 50th percentiles. For the percentiles 97 the difference, straight away present at five years, grows regularly up to 11 years, and remains thereafter for the girls at 4.3 units of BMI, while growing more up to 6.8 units of BMI at 15 years for the boys. The percentages of children and adolescents of the present study with overweight, in accordance with the thresholds of Cole, constant for the girls at 14%, increase for the five to 11.5 years old boys from 13.4% to 17.6% for the 11.5 to 16 years old. The percentage of obesity is 2.7% for the girls, and increase for the same categories for the boys from a percentage of 1.7% to 2.3% for the boys. CONCLUSIONS: The changes during this quarter of century are important, especially for the boys. We can postulate thereafter a very early change in the energy balance. A chronic increase of the food supply, linked or not with a decrease of the physical activity, would be an explanation.

Identification of an expanded population of activated CD4(+) CD25(+) T cells expressing CD45RO and IL-7R in kidney transplant recipients

Recent studies have shown that CD4+ CD25+ T cells belong to two functionally different T lymphocytes, i.e. regulatory T cells (Treg) or activated T cells (Tact), which can be distinguished based on the expression of CD45RO and IL-7R: Treg (FoxP3+) are CD45RO+ IL-7R- , whereas Tact (FoxP3- ) are CD45RO+ IL- 7R+. In order to determine if a CD4+ CD25+ CD45RO+ IL-7R+ activated T cell population might be identified in kidney transplant recipients, we studied 27 healthy subjects (HS) and 23 kidney recipients, of whom 17 had stable graft function under standard immunosuppression (IS), 5 had biopsy-proven chronic humoral rejection (CHR), and one was a stable "tolerant" patient who had discontinued IS for more than 2 years. Phenotypical analysis by flow cytometry and functional assays by MLR were performed. Overall, the Tact population was found to be significantly increased in 87% of the transplant recipients (mean: 18.8±10.1% of CD4+ CD25+ T cells) compared to HS (mean: 4.5±2.0%; P<0.0001). In the 5 patients with CHR, this Tact population was highly expanded (31.3±9.3%; P<0.0001), whereas it was comparable to HS in the "tolerant" recipient (4.7%). Intermediate levels (16.0±6.9%; P<0.0001) were found in the 17 stable recipients. In CHR, the proliferative capacity of the Tact population was found to be 5-fold higher when stimulated by irradiated donor PBMC as compared to a stimulation by irradiated 3rd party PBMC. After kidney transplantation, an expanded circulating CD4+ CD25+ T cell population characterized by the expression of CD45RO and IL-7R was found in most recipients, particularly in those with CHR. In a patient with long-term operational tolerance, this Tact population was similar to HS. Measuring circulating Tact may become a useful monitoring tool after transplantation.

Hyperhomocysteinemia is independently associed with albuminuria in the population-based CoLaus study

L'homocystéine est un molécule potentiellement atherogénique et est considéré comme facteur de risque indépendant pour les maladies cardiovasculaires. Pour les patients avec une maladie rénale chronique ou en général avec une fonction rénale diminuée le taux d'homocystéine dans le sérum est élevé. L'acide urique est associé avec un risque augmenté de développer une maladie rénale et prédit la mortalité pour les patients avec une maladie rénale chronique. Le but de cette étude était d'évaluer l'association entre des taux sériques d'homocystéine élevés est la présence d'une fonction rénale diminuée, exprimé par une filtration glomérulaire diminuée ou une albuminurie dans une sélection de la population de Lausanne. Nous avons aussi investigué l'effet de l'acide urique sur cette relation. Pour évaluer si l'association entre l'homocystéine est l'albuminurie pourra être causal, nous avons en même temps investigué l'association entra l'albuminurie est le polymorphisme du gène de la methylènetetrafolate réductase (MTHFR) fortement corrélé avec les taux sériques de l'homocystéine. L'étude CoLaus est transversale et basée sur la population. Elle représente une sélection aléatoire, non stratifié de la population générale de la ville de Lausanne, Suisse, âgée 35-75 ans (n=56.694). 5913 personnes étaient incluses dans l'analyse. La prévalence de l'albuminurie augmente dans les catégories de taux sériques croissants d'homocystéine. L'acide urique est associé avec la concentration sérique de l'homocystéine. Hyperhomocystéinémie et des taux sérique d'acide urique augmentés sont associés avec l'albuminurie, indépendant de l'hypertonie et du diabète. Dans cette étude basée sur une large population, l'association entre des taux sérique elevés d'homocystéine et la prévalence augmentée de l'albuminurie est indépendante de la fonction glomérulaire, indiquant que cette association n'est pas simplement la conséquence de la fonction rénale réduite. Hyperhomocystéinémie est associé avec un risque doublé pour une albuminurie, ce qu'est similaire au risque associé à l'hypertonie ou au diabète type 2. Cette association est indépendante de l'acide urique. Ce résultat suggère que l'hyperhomocystéinémie est un marqueur indépendant des la dysfonction rénale. Individus avec le polymorphisme du MTHFR associé avec des concentrations sériques élevées d'homocystéine sont associé avec un risque augmenté pour une albuminurie. Tous ces résultats supportent l'hypothèse que l'homocystéine cause des dommages rénaux.

Compliance with dietary recommendations in the population of Geneva, Switzerland: a ten-year trend study (1999-2009)

Introduction: There is little information regarding compliance with dietary recommendations in Switzerland. Objectives: To assess the trends in compliance with dietary recommendations in the Geneva population for period 1999 - 2009. Methods: Ten cross-sectional, population-based surveys (Bus Santé study). Dietary intake was assessed using a self-administered, validated semi quantitative Food Frequency Questionnaire. Compliance with the Swiss Society for Nutrition recommendations for nutrient intake was assessed. In all 9320 participants aged 35 to 75 years (50% women) were included. Trends were assessed by logistic regression adjusting for age, smoking stats, education and nationality, using survey year as the independent variable. Results: After excluding participants with extreme intakes, the percentage of participants with a cholesterol consumption< 300 mg/day increased from 40.8% in 1999 to 43.6% in 2009 for men (multivariate-adjusted p for trend = 0.04) and from 57.8% to 61.4% in women (multivariate-adjusted p for trend = 0.06). Calcium intake > 1 g/day decreased from 53.3% to 46.0% in men and from 47.6% to 40.7% in women (multivariate-adjusted p for trend< 0.001). Adequate iron intake decreased from 68.3%to 65.3% in men and from 13.3% to 8.4% in women (multivariate-adjusted p for trend< 0.001). Conversely, no significant changes were observed for carbohydrates, protein, total fat (including saturated, monounsaturated and polyunsaturated fatty acids), fibre, vitamins D and A. Conclusion: Fewimprovements were noted in adherence to dietary recommendations in the Geneva population between 1999 and 2009. The low and decreasing prevalence of adequate calcium and iron intake are of concern.

Comparison of the clientele of an anonymous HIV test centre and persons tested in the general population.

This study compares the clientele of a Swiss anonymous test centre with the general population tested. Information was obtained through similar questionnaires submitted to two samples of HIV-tested people aged from 17 to 45 years: the first administered in the context of a general population telephone survey (n = 245) and the second completed during face-to-face interviews of the clientele of an anonymous test centre (n = 250). The test centre sample has higher proportions of younger and single people. Attenders for anonymous testing were more likely to have acquired a new regular partner during the year preceding the interview (48.0% versus 14.4%). These differences remain when controlling for age and gender. Decision to test comes mostly from the respondent's own initiative, but suggestion from a doctor is more frequent in the general population (23.8% versus 0.8%), whereas suggestion from partner or friends is more frequent in the anonymous centre (44.4% versus 3.0%). The anonymous test centre clientele is not different from the general population tested except for the relational situation and origin of decision for testing. The test centre has become a place where the general population finds a response to a situation-specific need for HIV testing.

Combining probabilistic land-use change and tree population dynamics modelling to simulate responses in mountain forests

Altitudinal tree lines are mainly constrained by temperature, but can also be influenced by factors such as human activity, particularly in the European Alps, where centuries of agricultural use have affected the tree-line. Over the last decades this trend has been reversed due to changing agricultural practices and land-abandonment. We aimed to combine a statistical land-abandonment model with a forest dynamics model, to take into account the combined effects of climate and human land-use on the Alpine tree-line in Switzerland. Land-abandonment probability was expressed by a logistic regression function of degree-day sum, distance from forest edge, soil stoniness, slope, proportion of employees in the secondary and tertiary sectors, proportion of commuters and proportion of full-time farms. This was implemented in the TreeMig spatio-temporal forest model. Distance from forest edge and degree-day sum vary through feed-back from the dynamics part of TreeMig and climate change scenarios, while the other variables remain constant for each grid cell over time. The new model, TreeMig-LAb, was tested on theoretical landscapes, where the variables in the land-abandonment model were varied one by one. This confirmed the strong influence of distance from forest and slope on the abandonment probability. Degree-day sum has a more complex role, with opposite influences on land-abandonment and forest growth. TreeMig-LAb was also applied to a case study area in the Upper Engadine (Swiss Alps), along with a model where abandonment probability was a constant. Two scenarios were used: natural succession only (100% probability) and a probability of abandonment based on past transition proportions in that area (2.1% per decade). The former showed new forest growing in all but the highest-altitude locations. The latter was more realistic as to numbers of newly forested cells, but their location was random and the resulting landscape heterogeneous. Using the logistic regression model gave results consistent with observed patterns of land-abandonment: existing forests expanded and gaps closed, leading to an increasingly homogeneous landscape.

Substitution rates at neutral genes depend on population size under fluctuating demography and overlapping generations.

It is widely accepted that the rate of evolution (substitution rate) at neutral genes is unaffected by population size fluctuations. This result has implications for the analysis of genetic data in population genetics and phylogenetics, and provides, in particular, a justification for the concept of the molecular clock. Here, we show that the substitution rate at neutral genes does depend on population size fluctuations in the presence of overlapping generations. As both population size fluctuations and overlapping generations are expected to be the norm rather than the exception in natural populations, this observation may be relevant for understanding variation in substitution rates within and between lineages.

Comparative population genomics in animals uncovers the determinants of genetic diversity.

Genetic diversity is the amount of variation observed between DNA sequences from distinct individuals of a given species. This pivotal concept of population genetics has implications for species health, domestication, management and conservation. Levels of genetic diversity seem to vary greatly in natural populations and species, but the determinants of this variation, and particularly the relative influences of species biology and ecology versus population history, are still largely mysterious. Here we show that the diversity of a species is predictable, and is determined in the first place by its ecological strategy. We investigated the genome-wide diversity of 76 non-model animal species by sequencing the transcriptome of two to ten individuals in each species. The distribution of genetic diversity between species revealed no detectable influence of geographic range or invasive status but was accurately predicted by key species traits related to parental investment: long-lived or low-fecundity species with brooding ability were genetically less diverse than short-lived or highly fecund ones. Our analysis demonstrates the influence of long-term life-history strategies on species response to short-term environmental perturbations, a result with immediate implications for conservation policies.