Prevalence of methylphenidate prescription among school-aged children in a Swiss population: increase in the number of prescriptions in the Swiss Canton of Vaud, from 2002 to 2005, and changes in patient demographics.

OBJECTIVE: Methylphenidate is prescribed for children and adolescents to treat ADHD. As in many Western countries, the increase in methylphenidate consumption is a public concern in Switzerland. The article discusses the authors' assessment of prescription prevalence in 2002 and 2005 for school-aged children in the canton of Vaud. METHOD: Pharmacy prescription information is available from the regional public health authority. Descriptive analyses are conducted on an anonymized database of the years 2002 and 2005. Data for each year are compared to assess trends in methylphenidate prescription prevalence. RESULTS: The findings show an increase from 0.74% to 1.02% in the number of prescriptions for 5- to 14-year-old children, particularly in prescriptions for girls. Data also show important geographical differences in prescription. CONCLUSION: The prevalence of methylphenidate prescription is lower in Switzerland than other Western countries, particularly the United States. However, some aspects of prevalence are similar, including the increase per year, demographics, and geographic characteristics.

The behaviour of mosquitoes in relation to humans under holed bednets: the evidence from experimental huts

The physical integrity of bednets is a concern of national malaria control programs, as it is a key factor in determining the rate of replacement of bednets. It is largely assumed that increased numbers of holes will result in a loss of protection of sleepers from potentially infective bites. Experimental hut studies are valuable in understanding mosquito behaviour indoors, particularly as it relates to blood feeding and mortality. This review summarises findings from experimental hut studies, focusing on two issues: (i) the effect of different numbers or sizes of holes in bednets and (ii) feeding behaviour and mortality with holed nets as compared with unholed nets. As might be expected, increasing numbers and area of holes resulted in increased blood feeding by mosquitoes on sleepers. However, the presence of holes did not generally have a large effect on the mortality of mosquitoes. Successfully entering a holed mosquito net does not necessarily mean that mosquitoes spend less time in contact with the net, which could explain the lack in differences in mortality. Further behavioural studies are necessary to understand mosquito behaviour around nets and the importance of holed nets on malaria transmission.

Frequency and effects of meeting health behaviour guidelines among adolescents.

Background: To assess the relationship between overweight status and the concomitant adherence to physical activity, daily screen time and nutritional guidelines. Methods: Data were derived from the Swiss Health Behaviour in School-aged Children Survey 2006. Participants (n = 8130, 48.7% girls) were divided into two groups: normal weight (n = 7215, 44.8% girls) and overweight (n = 915, 34.8% girls), using self-reported height and weight. Groups were compared on adherence to physical activity, screen time and nutritional guidelines. Bivariate analyses were carried out followed by multivariate analyses using normal-weight individuals as the reference category. Results: Regardless of gender, overweight individuals reported more screen time, less physical activity and less concomitant adherence to guidelines. For boys, the multivariate analysis showed that any amount exceeding screen time recommendations was associated with increased odds of being overweight [>2-4 h: adjusted odds ratio (AOR) = 1.40; >4-6 h: AOR = 1.48; >6 h: AOR = 1.83]. A similar relation was found for any amount below physical activity recommendations (4-6 times a week: AOR = 1.67; 2-3 times a week: AOR = 1.87; once a week or less: AOR = 2.1). For girls, not meeting nutritional guidelines was less likely among overweight individuals (0-2 recommendations: AOR = 0.54). Regardless of weight status, more than half of the adolescents did not comply with any guideline and <2% met all three at the same time. Conclusions: Meeting current nutritional, physical activity and screen time guidelines should be encouraged with respect to overweight. However, as extremely low rates of concomitant adherence were found regardless of weight status, their achievability is questionable (especially for nutrition), which warrants further research to better adapt them to adolescents.

Behavioural alterations are independent of sickness behaviour in chronic experimental Chagas disease

The existence of the nervous form of Chagas disease is a matter of discussion since Carlos Chagas described neurological disorders, learning and behavioural alterations in Trypanosoma cruzi-infected individuals. In most patients, the clinical manifestations of the acute phase, including neurological abnormalities, resolve spontaneously without apparent consequence in the chronic phase of infection. However, chronic Chagas disease patients have behavioural changes such as psychomotor alterations, attention and memory deficits, and depression. In the present study, we tested whether or not behavioural alterations are reproducible in experimental models. We show that C57BL/6 mice chronically infected with the Colombian strain of T. cruzi (150 days post-infection) exhibit behavioural changes as (i) depression in the tail suspension and forced swim tests, (ii) anxiety analysed by elevated plus maze and open field test sand and (iii) motor coordination in the rotarod test. These alterations are neither associated with neuromuscular disorders assessed by the grip strength test nor with sickness behaviour analysed by temperature variation sand weight loss. Therefore, chronically T. cruzi-infected mice replicate behavioural alterations (depression and anxiety) detected in Chagas disease patients opening an opportunity to study the interconnection and the physiopathology of these two biological processes in an infectious scenario.

Implications of the serpentine phase transition on the behaviour of beryllium and lithium-boron of subducted ultramafic rocks

The Totalp-Platta-Malenco ophiolites in the Eastern Central Alps offer a unique opportunity to study the behaviour of Li, Be and B in ultramafic rocks in response to serpentinization and to progressive Alpine metamorphism. These units represent the remnants of a former ocean-continent transition that was intensely serpentinized during exposure on the Jurassic seafloor of the Ligurian Tethys. From north to the south, three isograd reactions (lizardite double right arrow antigorite + brucite; lizardite + talc double right arrow antigorite; lizardite + tremolite double right arrow antigorite + diopside) have been used to quantify the evolution of the light element content of metamorphic minerals. We determined the Li, Be and B concentrations in major silicate minerals from the ultramafic bodies of Totalp, Platta and Malenco by secondary ion mass spectrometry. Mantle minerals have Be concentrations (e.g. <0.001-0.009 mu g/g in olivine) similar to the metamorphic minerals that replace them (e.g. <0.001-0.016 mu g/g in serpentine). The mantle signature of Be is thus neither erased during seafloor alteration nor by progressive metamorphism from prehnite-pumpellyite to epidote-amphibolite facies. In contrast, the Li and B inventories of metamorphic minerals are related to the lizardite-to-antigorite transition. Both elements display higher concentrations in the low-temperature serpentine polymorph lizardite (max. 156 mu/g Li, max. 318 mu g/g B) than in antigorite (max. 0.11 mu g/g Li, max. 12 mu g/g B). Calculated average B/Li ratios for lizardite (similar to 1395) and antigorite (similar to 115) indicate that Li fractionates from B during the lizardite-to-antigorite transition during prograde metamorphism in ultramafic rocks. In subduction zones, this signature is likely to be recorded in the B-rich nature of forearc fluids. Relative to oceanic mantle the Be content of mantle clinopyroxene is much higher, but similar to Be values from mantle xenoliths and subduction-related peridotite massifs. These data support previous hypothesis that the mantle rocks from the Eastern Central Alps have a subcontinental origin. We conclude that Be behaves conservatively during subduction metamorphism of ultramafic rocks, at least at low-temperature, and thus retains the fingerprint of ancient subduction-related igneous events in mantle peridotites. (C) 2010 Elsevier Ltd. All rights reserved.

Gac/Rsm signal transduction pathway of gamma-proteobacteria: from RNA recognition to regulation of social behaviour.

In many gamma-proteobacteria, the conserved GacS/GacA (BarA/UvrY) two-component system positively controls the expression of one to five genes specifying small RNAs (sRNAs) that are characterized by repeated unpaired GGA motifs but otherwise appear to belong to several independent families. The GGA motifs are essential for binding small, dimeric RNA-binding proteins of a single conserved family designated RsmA (CsrA). These proteins, which also occur in bacterial species outside the gamma-proteobacteria, act as translational repressors of certain mRNAs when these contain an RsmA/CsrA binding site at or near the Shine-Dalgarno sequence plus additional binding sites located in the 5' untranslated leader mRNA. Recent structural data have established that the RsmA-like protein RsmE of Pseudomonas fluorescens makes specific contacts with an RNA consensus sequence 5'-(A)/(U)CANGGANG(U)/(A)-3' (where N is any nucleotide). Interaction with an RsmA/CsrA protein promotes the formation of a short stem supporting an ANGGAN loop. This conformation hinders access of 30S ribosomal subunits and hence translation initiation. The output of the Gac/Rsm cascade varies widely in different bacterial species and typically involves management of carbon storage and expression of virulence or biocontrol factors. Unidentified signal molecules co-ordinate the activity of the Gac/Rsm cascade in a cell population density-dependent manner.

Non-medical prescription drug and illicit street drug use among young Swiss men and associated mental health issues.

Non-medical use of prescription drugs (NMUPD) is increasing among the general population, particularly among teenagers and young adults. Although prescription drugs are considered safer than illicit street drugs, NMUPD can lead to detrimental consequences. The aim of the present study was to investigate the relationship between drug use (NMUPD on the one side, illicit street drugs on the other side) with mental health issues and then compare these associations. A representative sample of 5719 young Swiss men aged around 20 years filled in a questionnaire as part of the ongoing baseline Cohort Study on Substance Use Risk Factors (C-SURF). Drug use (16 illicit street drugs and 5 NMUPDs, including sleeping pills, sedatives, pain killers, antidepressants, stimulants) and mental health issues (depression, SF12) were assessed. Simple and multiple linear regressions were employed. In simple regressions, all illicit and prescription drugs were associated with poorer mental health. In multiple regressions, most of the NMUPDs, except for stimulants, were significantly associated with poorer mental health and with depression. On the contrary, the only associations that remained significant between illicit street drugs and mental health involved cannabis. NMUPD is of growing concern not only because of its increasing occurrence, but also because of its association with depression and mental health problems, which is stronger than the association observed between these problems and illicit street drug use, excepted for cannabis. Therefore, NMUPD must be considered in screening for substance use prevention purposes.

A model for physical activity, bahaviour and energy expenditure assessment in real-life condition

RésuméL'origine de l'obésité, qui atteint des proportions épidémiques, est complexe. Elle est liée au mode de vie et au comportement des individus par rapport à l'activité physique, expression des choix individuels et de l'interaction avec l'environnement. Les mesures du comportement au niveau de l'activité physique des individus face à leur environnement, la répartition des types d'activité physique, la durée, la fréquence, l'intensité, et la dépense énergétique sont d'une grande importance. Aujourd'hui, il y a un manque de méthodes permettant une évaluation précise et objective de l'activité physique et du comportement des individus. Afin de compléter les recherches relatives à l'activité physique, à l'obésité et à certaines maladies, le premier objectif du travail de thèse était de développer un modèle pour l'identification objective des types d'activité physique dans des conditions de vie réelles et l'estimation de la dépense énergétique basée sur une combinaison de 2 accéléromètres et 1 GPS. Le modèle prend en compte qu'une activité donnée peut être accomplie de différentes façons dans la vie réelle. Les activités quotidiennes ont pu être classées en 8 catégories, de sédentaires à actives, avec une précision de 1 min. La dépense énergétique a pu peut être prédite avec précision par le modèle. Après validation du modèle, le comportement des individus de l'activité physique a été évalué dans une seconde étude. Nous avons émis l'hypothèse que, dans un environnement caractérisé par les pentes, les personnes obèses sont tentées d'éviter les pentes raides et de diminuer la vitesse de marche au cours d'une activité physique spontanée, ainsi que pendant les exercices prescrits et structurés. Nous avons donc caractérisé, par moyen du modèle développé, le comportement des individus obèses dans un environnement vallonné urbain. La façon dont on aborde un environnement valloné dans les déplacements quotidiens devrait également être considérée lors de la prescription de marche supplémentaire afin d'augmenter l'activité physique.SummaryOrigin of obesity, that reached epidemic proportion, is complex and may be linked to different lifestyle and physical activity behaviour. Measurement of physical activity behaviour of individuals towards their environment, the distribution of physical activity in terms of physical activity type, volume, duration, frequency, intensity, and energy expenditure is of great importance. Nowadays, there is a lack of methods for accurate and objective assessment of physical activity and of individuals' physical activity behaviour. In order to complement the research relating physical activity to obesity and related diseases, the first aim of the thesis work was to develop a model for objective identification of physical activity types in real-life condition and energy expenditure based on a combination of 2 accelerometers and 1 GPS device. The model takes into account that a given activity can be achieved in many different ways in real life condition. Daily activities could be classified in 8 categories, as sedentary to active physical activity, within 1 min accuracy, and physical activity patterns determined. The energy expenditure could be predicted accurately with an accuracy below 10%. Furthermore, individuals' physical activity behaviour is expression of individual choices and their interaction with the neighbourhood environment. In a second study, we hypothesized that, in an environment characterized by inclines, obese individuals are tempted to avoid steep positive slopes and to decrease walking speed during spontaneous outdoor physical activity, as well as during prescribed structured bouts of exercise. Finally, we characterized, by mean of the developed model, the physical activity behaviour of obese individuals in a hilly urban environment. Quantifying how one tackles hilly environment or avoids slope in their everyday displacements should be also considered while prescribing extra walking in free-living conditions in order to increase physical activity.

Massive nest-box supplementation boosts fecundity, survival and even immigration without altering mating and reproductive behaviour in a rapidly recovered bird population.

Habitat restoration measures may result in artificially high breeding density, for instance when nest-boxes saturate the environment, which can negatively impact species' demography. Potential risks include changes in mating and reproductive behaviour such as increased extra-pair paternity, conspecific brood parasitism, and polygyny. Under particular cicumstances, these mechanisms may disrupt reproduction, with populations dragged into an extinction vortex. With the use of nuclear microsatellite markers, we investigated the occurrence of these potentially negative effects in a recovered population of a rare secondary cavity-nesting farmland bird of Central Europe, the hoopoe (Upupa epops). High intensity farming in the study area has resulted in a total eradication of cavity trees, depriving hoopoes from breeding sites. An intensive nest-box campaign rectified this problem, resulting in a spectacular population recovery within a few years only. There was some concern, however, that the new, high artificially-induced breeding density might alter hoopoe mating and reproductive behaviour. As the species underwent a serious demographic bottleneck in the 1970-1990s, we also used the microsatellite markers to reconstitute the demo-genetic history of the population, looking in particular for signs of genetic erosion. We found i) a low occurrence of extra-pair paternity, polygyny and conspecific brood parasitism, ii) a high level of neutral genetic diversity (mean number of alleles and expected heterozygosity per locus: 13.8 and 83%, respectively) and, iii) evidence for genetic connectivity through recent immigration of individuals from well differentiated populations. The recent increase in breeding density did thus not induce so far any noticeable detrimental changes in mating and reproductive behaviour. The demographic bottleneck undergone by the population in the 1970s-1990s was furthermore not accompanied by any significant drop in neutral genetic diversity. Finally, genetic data converged with a concomitant demographic study to evidence that immigration strongly contributed to local population recovery.

Participation in a population-based physical activity programme as an aid for smoking cessation: a randomised trial.

OBJECTIVES: Exercise combined with nicotine therapy may help smoking cessation and minimise weight gain after quitting. Low participation in vigorous-intensity physical activity programmes precludes their population-wide applicability. In a randomised controlled trial, we tested whether a population-based moderate-intensity physical activity programme increases quit rates among sedentary smokers receiving nicotine therapy. METHODS: Participants (n=481; 57% male; mean age, 42.2 years (SD 10.1); mean cigarette consumption, 27 (SD 10.2) per day) were offered a nine-week smoking cessation programme consisting of a weekly 15-minute counselling session and the prescription of nicotine replacement therapy. In addition, participants in the physical activity group (n=229) also took part in a programme of moderate-intensity physical activity implemented at the national level, and offering nine weekly 60-minute sessions of physical activity. To ensure equal contact conditions, participants in the control group (n=252) attended weekly 60-minute health behaviour education sessions unrelated to physical activity. The primary outcome was continuous CO-verified smoking abstinence rates at 1-year follow-up. RESULTS: Continuous smoking abstinence rates were high and similar in the physical activity group and the control group at the end of the intervention (47% versus 46%, p=0.81) and at 1-year follow-up (27% versus 29%, p=0.71). The mean weight gain after one year was 4.4 kg and 6.2 kg among sustained quitters of the physical activity and control groups, respectively (p=0.06). CONCLUSION: Participation in a population-based moderate-intensity physical activity programme for 9 weeks in addition to a comprehensive smoking cessation programme did not significantly increase smoking cessation rates. A non-significant reduction in weight gain was observed among participants who quit smoking in the physical activity group. TRIAL REGISTRATION: ClinicalTrials.gov; US National Institutes for Health (available online at http://clinicaltrials.gov/; CLINICAL TRIAL REGISTRATION NUMBER: NCT00521391).