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Find video protocols related to scientific articles indexed in Pubmed.
Efficacy of an internet and SMS-based integrated smoking cessation and alcohol intervention for smoking cessation in young people: study protocol of a two-arm cluster randomised controlled trial.
BMC Public Health
PUBLISHED: 10-22-2014
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Tobacco smoking prevalence continues to be high, particularly among adolescents and young adults with lower educational levels, and is therefore a serious public health problem. Tobacco smoking and problem drinking often co-occur and relapses after successful smoking cessation are often associated with alcohol use. This study aims at testing the efficacy of an integrated smoking cessation and alcohol intervention by comparing it to a smoking cessation only intervention for young people, delivered via the Internet and mobile phone.
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Revealing cell assemblies at multiple levels of granularity.
J. Neurosci. Methods
PUBLISHED: 08-26-2014
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Current neuronal monitoring techniques, such as calcium imaging and multi-electrode arrays, enable recordings of spiking activity from hundreds of neurons simultaneously. Of primary importance in systems neuroscience is the identification of cell assemblies: groups of neurons that cooperate in some form within the recorded population.
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Efficacy of a web- and text messaging-based intervention to reduce problem drinking in young people: study protocol of a cluster-randomised controlled trial.
BMC Public Health
PUBLISHED: 07-10-2014
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Problem drinking, particularly risky single-occasion drinking is widespread among adolescents and young adults in most Western countries. Mobile phone text messaging allows a proactive and cost-effective delivery of short messages at any time and place and allows the delivery of individualised information at times when young people typically drink alcohol. The main objective of the planned study is to test the efficacy of a combined web- and text messaging-based intervention to reduce problem drinking in young people with heterogeneous educational level.
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Queer quit: a pilot study of a smoking cessation programme tailored to gay men.
BMC Public Health
PUBLISHED: 02-04-2014
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The prevalence of cigarette smoking among adult gay males is higher than that of heterosexuals. There is a need for interventions adapted to gay culture. We conducted a pilot study using a modified version of a British smoking intervention programme tailored to gay men in Switzerland. As the main outcome, we assessed point prevalence smoking abstinence six months following programme attendance.
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Predictors of adolescent smoking cessation and smoking reduction.
Patient Educ Couns
PUBLISHED: 01-30-2014
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To investigate the processes of change, demographic, health- and smoking-related predictors of both smoking cessation and smoking reduction in adolescents.
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Multidimensional family therapy decreases the rate of externalising behavioural disorder symptoms in cannabis abusing adolescents: outcomes of the INCANT trial.
BMC Psychiatry
PUBLISHED: 01-30-2014
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US-based trials have shown that Multidimensional Family Therapy (MDFT) not only reduces substance abuse among adolescents, but also decreases mental and behavioural disorder symptoms, most notably externalising symptoms. In the INCANT trial, MDFT decreased the rate of cannabis dependence among Western European youth. We now focus on other INCANT outcomes, i.e., lessening of co-morbidity symptoms and improvement of family functioning.
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Immigrants are attracted by local pre-breeders and recruits in a seabird colony.
J Anim Ecol
PUBLISHED: 01-20-2014
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Immigration is a major demographic factor shaping population dynamics. However, due to methodological difficulties, the extent of immigration and factors affecting immigration are insufficiently studied. This is also true for seabird colonies. We estimated annual immigration based on a long-term study of a colony of common terns Sterna hirundo marked with transponders, using a Bayesian integrated population model that links colony size and productivity with individual life histories. Strong annual fluctuations in the number of immigrants were found. To identify whether colony-specific covariates influenced immigration, we related the number of immigrants to various proxy variables for breeding site quality, specifically colony size, productivity, number of local subadults and local recruits. Numbers of local recruits and local subadults showed strong positive correlations with number of immigrants. We found that variation in immigration rate had strongly contributed to variation in colony growth rate, more so than variation in local recruitment or adult survival. Collectively, results suggest that immigration strongly affects colony growth rate, that the driving force behind immigration is natal dispersal and that immigrants were attracted by local recruits.
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Territory occupancy and parental quality as proxies for spatial prioritization of conservation areas.
PLoS ONE
PUBLISHED: 01-01-2014
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In order to maximize their fitness, individuals aim at choosing territories offering the most appropriate combination of resources. As population size fluctuates in time, the frequency of breeding territory occupancy reflects territory quality. We investigated the relationships between the frequency of territory occupancy (2002-2009) vs. habitat characteristics, prey abundance, reproductive success and parental traits in hoopoes Upupa epops L., with the objective to define proxies for the delineation of conservation priority areas. We predicted that the distribution of phenotypes is despotic and sought for phenotypic characteristics expressing dominance. Our findings support the hypothesis of a despotic distribution. Territory selection was non-random: frequently occupied territories were settled earlier in the season and yielded higher annual reproductive success, but the frequency of territory occupancy could not be related to any habitat characteristics. Males found in frequently occupied territories showed traits expressing dominance (i.e. larger body size and mass, and older age). In contrast, morphological traits of females were not related to the frequency of territory occupancy, suggesting that territory selection and maintenance were essentially a male's task. Settlement time in spring, reproductive success achieved in a given territory, as well as phenotypic traits and age of male territory holders reflected territory quality, providing good proxies for assessing priority areas for conservation management.
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Seasonal survival probabilities suggest low migration mortality in migrating bats.
PLoS ONE
PUBLISHED: 01-01-2014
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Migration is adaptive if survival benefits are larger than costs of residency. Many aspects of bat migration ecology such as migratory costs, stopover site use and fidelity are largely unknown. Since many migrating bats are endangered, such information is urgently needed to promote conservation. We selected the migrating Leisler's bat (Nyctalus leisleri) as model species and collected capture-recapture data in southern Switzerland year round during 6 years. We estimated seasonal survival and site fidelity with Cormack-Jolly-Seber models that accounted for the presence of transients fitted with Bayesian methods and assessed differences between sexes and seasons. Activity peaked in autumn and spring, whereas very few individuals were caught during summer. We hypothesize that the study site is a migratory stopover site used during fall and spring migration for most individuals, but there is also evidence for wintering. Additionally, we found strong clues for mating during fall. Summer survival that included two major migratory journeys was identical to winter survival in males and slightly higher in females, suggesting that the migratory journeys did not bear significant costs in terms of survival. Transience probability was in both seasons higher in males than in females. Our results suggest that, similarly to birds, Leisler's bat also use stopover sites during migration with high site fidelity. In contrast to most birds, the stopover site was also used for mating and migratory costs in terms of survival seemed to be low. Transients' analyses highlighted strong individual variation in site use which makes particularly challenging the study and modelling of their populations as well as their conservation.
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Group hypnosis vs. relaxation for smoking cessation in adults: a cluster-randomised controlled trial.
BMC Public Health
PUBLISHED: 09-26-2013
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Despite the popularity of hypnotherapy for smoking cessation, the efficacy of this method is unclear. We aimed to investigate the efficacy of a single-session of group hypnotherapy for smoking cessation compared to relaxation in Swiss adult smokers.
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Strong contribution of immigration to local population regulation: evidence from a migratory passerine.
Ecology
PUBLISHED: 09-11-2013
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A mechanistic understanding of the dynamics of populations requires knowledge about the variation of the underlying demographic rates and about the reasons for their variability. In geographically open populations, immigration is often necessary to prevent declines, but little is known about whether immigration can contribute to its regulation. We studied the dynamics of a Red-backed Shrike population (Lanius collurio) over 36 years in Germany with a Bayesian integrated population model. We estimated mean and temporal variability of population sizes, productivity, apparent survival, and immigration. We assessed how strongly the demographic rates were correlated with population growth to understand the demographic reasons of population change and how strongly the demographic rates were correlated with population size to identify possible density-dependent mechanisms. The shrike population varied between 35 and 74 breeding pairs but did not show a significant trend in population size over time (growth rate 1.002 +/- 0.001 [mean +/- SD]). Apparent survival of females (juveniles 0.06 +/- 0.01; adults 0.37 +/- 0.03) was lower than that of males (juveniles 0.10 +/- 0.01; adults 0.44 +/- 0.02). Immigration rates were substantial and higher in females (0.56 +/- 0.02) than in males (0.43 +/- 0.02), and average productivity was 2.76 +/- 0.14. Without immigration, the Red-backed Shrike population would have declined strongly. Immigration was the strongest driver for the number of females while local recruitment was the most important driver for the number of males. Immigration of both sexes and productivity, but not local recruitment and survival, were subject to density dependence. Density-dependent productivity was not effectively regulating the local population but may have contributed to regulate shrike populations at larger spatial scales. These findings suggest that immigration is not only an important component to prevent a geographically open population from decline, but that it can also contribute to its regulation.
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[Moderators of outcome in a text messaging (SMS)--based smoking cessation intervention for young people].
Psychiatr Prax
PUBLISHED: 09-05-2013
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The results of a cluster randomised trial testing the efficacy of a text messaging (SMS)-based program for smoking cessation in vocational school students showed no short-term effects on smoking cessation; however the program resulted in lower cigarette consumption. Furthermore, occasional smokers of the intervention group made more attempts to quit smoking than occasional smokers in the control group.
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Can reduce - the effects of chat-counseling and web-based self-help, Web-based self-help alone and a waiting list control program on cannabis use in problematic cannabis users: a randomized controlled trial.
BMC Psychiatry
PUBLISHED: 08-15-2013
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In European countries, including Switzerland, as well as in many states worldwide, cannabis is the most widely used psychoactive substance after alcohol and tobacco. Although approximately one in ten users develop serious problems of dependency, only a minority attends outpatient addiction counseling centers. The offer of a combined web-based self-help and chat counseling treatment could potentially also reach those users who hesitate to approach such treatment centers and help them to reduce their cannabis use.Methods/design: This paper presents the protocol for a three-armed randomized controlled trial that will test the effectiveness of a web-based self-help intervention in combination with, or independent of, tailored chat counseling compared to a waiting list in reducing or enabling the abstention from cannabis use in problematic users. The primary outcome will be the weekly quantity of cannabis used. Secondary outcome measures will include the number of days per week on which cannabis is used, the severity of cannabis use disorder, the severity of cannabis dependence, cannabis withdrawal symptoms, cannabis craving, the use of alcohol, tobacco, and other non-cannabis illicit drugs, changes in mental health symptoms, and treatment retention. The self-help intervention will consist of 8 modules designed to reduce cannabis use based on the principles of motivational interviewing, self-control practices, and methods of cognitive behavioral therapy. The two additional individual chat-counseling sessions in the additional chat condition will be based on the same therapy approaches and tailored to participants self-help information data and personal problems. The predictive validity of participants baseline characteristics on treatment retention and outcomes will be explored.
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A pre-post study on the appropriateness and effectiveness of a Web- and text messaging-based intervention to reduce problem drinking in emerging adults.
J. Med. Internet Res.
PUBLISHED: 06-07-2013
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Problem drinking, particularly risky single-occasion drinking (RSOD), also called "binge drinking", is widespread among adolescents and young adults in most Western countries. Few studies have tested the effectiveness of interventions to reduce RSOD in young people with heterogeneous and particularly lower educational background.
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Efficacy of a text message-based smoking cessation intervention for young people: a cluster randomized controlled trial.
J. Med. Internet Res.
PUBLISHED: 03-27-2013
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Smoking prevalence remains high, particularly among adolescents and young adults with lower educational levels, posing a serious public health problem. There is limited evidence of effective smoking cessation interventions in this population.
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Development of an integrative cessation program for co-smokers of cigarettes and cannabis: demand analysis, program description, and acceptability.
Subst Abuse Treat Prev Policy
PUBLISHED: 03-12-2013
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Tobacco and cannabis use are strongly interrelated, but current national and international cessation programs typically focus on one substance, and address the other substance either only marginally or not at all. This study aimed to identify the demand for, and describe the development and content of, the first integrative group cessation program for co-smokers of cigarettes and cannabis.
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Building a European consensus on minimum quality standards for drug treatment, rehabilitation and harm reduction.
Eur Addict Res
PUBLISHED: 03-11-2013
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The Study on the Development of an EU Framework for Minimum Quality Standards and Benchmarks in Drug Demand Reduction (EQUS) has set up an inventory of quality standards and initiated a consensus-building process, aiming at establishing a set of European minimum quality standards (MQS) for treatment/rehabilitation and harm reduction in the field of drug abuse and dependence.
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Predictors of hazardous drinking, tobacco smoking and physical inactivity in vocational school students.
BMC Public Health
PUBLISHED: 01-14-2013
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Tobacco smoking, hazardous drinking and physical inactivity during adolescence are risk factors that are associated with poorer health in adulthood. The identification of subgroups of young people with a high prevalence of one or more of these risk factors allows an optimised allocation of preventive measures. This study aimed at investigating hazardous drinking, tobacco smoking and physical inactivity as well as their associations and demographic predictors in vocational school students.
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Modulation of the adrenocortical response to acute stress with respect to brood value, reproductive success and survival in the Eurasian hoopoe.
Oecologia
PUBLISHED: 01-14-2013
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Reproducing parents face the difficult challenge of trading-off investment in current reproduction against presumed future survival and reproduction. Glucocorticoids are supposed to mediate this trade-off because the adrenocortical response to stress disrupts normal reproductive behaviour in favour of self-maintenance and own survival. According to the brood-value hypothesis, individuals with a low survival probability until the next reproductive season have to invest in current reproduction, a process driven by a down-regulation of their adrenocortical response. If the adrenocortical response to stress effectively mediates the trade-off between current reproduction versus future survival and reproduction, we expect a negative relationship with reproductive success and a positive correlation of the adrenocortical stress response with survival. We studied the relationship between corticosterone secretion in parents and their current brood value, reproductive success and survival in a short-lived multi-brooded bird, the Eurasian hoopoe Upupa epops. The adrenocortical response to acute handling stress was correlated with the brood value within the individual (first and second broods of the year) and between individuals. Birds breeding late in the season mounted a lower total corticosterone response to acute stress than birds breeding earlier, while females showed lower levels than males. We observed a negative relationship between the adrenocortical stress response and rearing success or fledging success in females, as predicted by the brood-value hypothesis. However, we could not evidence a clear link between the adrenocortical stress response and survival. Future research testing the brood-value hypothesis and trade-offs between current reproduction and future survival should also measure free corticosterone and carefully differentiate between cross-sectional (i.e. between-individual) and individual-based experimental studies.
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To Dope or Not to Dope: Neuroenhancement with Prescription Drugs and Drugs of Abuse among Swiss University Students.
PLoS ONE
PUBLISHED: 01-01-2013
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Neuroenhancement is the use of substances by healthy subjects to enhance mood or cognitive function. The prevalence of neuroenhancement among Swiss university students is unknown. Investigating the prevalence of neuroenhancement among students is important to monitor problematic use and evaluate the necessity of prevention programs.
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The demographic drivers of local population dynamics in two rare migratory birds.
Oecologia
PUBLISHED: 06-28-2011
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The exchange of individuals among populations can have strong effects on the dynamics and persistence of a given population. Yet, estimation of immigration rates remains one of the greatest challenges for animal demographers. Little empirical knowledge exists about the effects of immigration on population dynamics. New integrated population models fitted using Bayesian methods enable simultaneous estimation of fecundity, survival and immigration, as well as the growth rate of a population of interest. We applied this novel analytical framework to the demography of two populations of long-distance migratory birds, hoopoe Upupa epops and wryneck Jynx torquilla, in a study area in south-western Switzerland. During 2002-2010, the hoopoe population increased annually by 11%, while the wryneck population remained fairly stable. Apparent juvenile and adult survival probability was nearly identical in both species, but fecundity and immigration were slightly higher in the hoopoe. Hoopoe population growth rate was strongly correlated with juvenile survival, fecundity and immigration, while that of wrynecks strongly correlated only with immigration. This indicates that demographic components impacting the arrival of new individuals into the populations were more important for their dynamics than demographic components affecting the loss of individuals. The finding that immigration plays a crucial role in the population growth rates of these two rare species emphasizes the need for a broad rather than local perspective for population studies, and the development of wide-scale conservation actions.
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Snow control - an RCT protocol for a web-based self-help therapy to reduce cocaine consumption in problematic cocaine users.
BMC Psychiatry
PUBLISHED: 06-02-2011
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Cocaine use has increased in most European countries, including Switzerland, and many states worldwide. The international literature has described treatment models that target the general population. In addition to supplying informative measures at the level of primary and secondary prevention, the literature also offers web-based self-help tools for problematic substance users, which is in line with tertiary prevention. Such programs, however, have been primarily tested on individuals with problematic alcohol and cannabis consumption, but not on cocaine-dependent individuals.
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The Ising decoder: reading out the activity of large neural ensembles.
J Comput Neurosci
PUBLISHED: 05-22-2011
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The Ising model has recently received much attention for the statistical description of neural spike train data. In this paper, we propose and demonstrate its use for building decoders capable of predicting, on a millisecond timescale, the stimulus represented by a pattern of neural activity. After fitting to a training dataset, the Ising decoder can be applied "online" for instantaneous decoding of test data. While such models can be fit exactly using Boltzmann learning, this approach rapidly becomes computationally intractable as neural ensemble size increases. We show that several approaches, including the Thouless-Anderson-Palmer (TAP) mean field approach from statistical physics, and the recently developed Minimum Probability Flow Learning (MPFL) algorithm, can be used for rapid inference of model parameters in large-scale neural ensembles. Use of the Ising model for decoding, unlike other problems such as functional connectivity estimation, requires estimation of the partition function. As this involves summation over all possible responses, this step can be limiting. Mean field approaches avoid this problem by providing an analytical expression for the partition function. We demonstrate these decoding techniques by applying them to simulated neural ensemble responses from a mouse visual cortex model, finding an improvement in decoder performance for a model with heterogeneous as opposed to homogeneous neural tuning and response properties. Our results demonstrate the practicality of using the Ising model to read out, or decode, spatial patterns of activity comprised of many hundreds of neurons.
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Demographic response to environmental variation in breeding, stopover and non-breeding areas in a migratory passerine.
Oecologia
PUBLISHED: 04-05-2011
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Demographic rates of migratory species passing through several areas during their annual cycle may be affected by environmental conditions at each of these areas. Recent studies provide evidence that their impact is not necessarily immediate, but can be delayed. We studied survival, reproductive success and arrival date at the breeding grounds of red-backed shrikes Lanius collurio, a trans-Saharan migrant, in relation to weather and vegetation on the breeding grounds, the stopover sites during migration and in the wintering areas. These environmental factors are used as proxy of the shrikes food supply. We analysed detailed demographic data of some 4,600 individuals from 25 years with multistate capture-recapture and mixed models. Survival probabilities of juveniles and breeders of both sexes varied in parallel across time, suggesting that all cohorts were sensitive to similar causes of mortality. Reproductive performance increased with temperature and decreased with rainfall on the breeding area. Moreover, it increased with vegetation cover in the Sahelian stopover area used on autumn migration suggesting a carry-over effect. Arrival date was negatively affected by spring temperatures in the breeding area. Hence, demographic rates were affected by environmental factors on the breeding grounds, but also outside and elsewhere. This suggests that the shrikes population dynamics are driven by environmental factors operating at various scales of space and time. However, only a small amount of the temporal variation in demographic rates is explained by the environmental factors considered, suggesting that additional factors, such as those operating during migration, might be important.
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Predictors of retention in the voluntary and quasi-compulsory treatment of substance dependence in europe.
Eur Addict Res
PUBLISHED: 01-13-2011
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Policies and practices related to the quasi-compulsory treatment (QCT) of substance-dependent offenders are currently implemented in many countries, despite the absence of reliable knowledge about significant predictors of treatment retention. This study aimed to identify such predictors in QCT and voluntary treatment.
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Drug Checking: A prevention measure for a heterogeneous group with high consumption frequency and polydrug use - evaluation of zurichs drug checking services.
Harm Reduct J
PUBLISHED: 01-05-2011
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The increasing party culture in Zurich presents new challenges, especially regarding the consumption of alcohol and so-called party drugs. Streetwork, the youth advisory service of the city of Zurich, has provided onsite and stationary Drug Checking facilities since 2001 and 2006, respectively. Drug Checking always involves filling out an anonymous questionnaire, which allows the collection of important information about a largely unknown group of users and their consumption patterns.
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Developing a smoking cessation program for Turkish-speaking migrants in Switzerland: novel findings and promising effects.
Nicotine Tob. Res.
PUBLISHED: 12-24-2010
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Recent studies show that smoking prevalence in the Turkish-speaking migrant population in Switzerland is substantially higher than in the general population. A specific group treatment for Turkish-speaking migrants was developed and tested in order to provide the migrant population with equal access to smoking cessation programs and to improve the migration-sensitive quality of such programs by sociocultural targeting.
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Impact of density and environmental factors on population fluctuations in a migratory passerine.
J Anim Ecol
PUBLISHED: 10-07-2010
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1. Populations of plants and animals typically fluctuate because of the combined effects of density-dependent and density-independent processes. The study of these processes is complicated by the fact that population sizes are typically not known exactly, because population counts are subject to sampling variance. Although the existence of sampling variance is broadly acknowledged, relatively few studies on time-series data have accounted for it, which can result in wrong inferences about population processes. 2. To increase our understanding of population dynamics, we analysed time series from six Central European populations of the migratory red-backed shrike Lanius collurio by simultaneously assessing the strength of density dependence, process and sampling variance. In addition, we evaluated hypotheses predicting effects of factors presumed to operate on the breeding grounds, at stopover sites in eastern Africa during fall and spring migration and in the wintering grounds in southern Africa. We used both simple and state-space formulations of the Gompertz equation to model population size. 3. Across populations and modelling approaches, we found consistent evidence for negative density-dependent population regulation. Further, process variance contributed substantially to variation in population size, while sampling variance did not. Environmental conditions in eastern and southern Africa appear to influence breeding population size, as rainfall in the Sahel during fall migration and in the south African wintering areas were positively related to population size in the following spring in four of six populations. In contrast, environmental conditions in the breeding grounds were not related to population size. 4. Our findings suggest negative density-dependent regulation of red-backed shrike breeding populations and are consistent with the long-standing hypothesis that conditions in the African staging and wintering areas influence population numbers of species breeding in Europe. 5. This study highlights the importance of jointly investigating density-dependent and density-independent processes to improve our understanding of factors influencing population fluctuations in space and time.
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Assessing whether mortality is additive using marked animals: a Bayesian state-space modeling approach.
Ecology
PUBLISHED: 08-19-2010
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Whether different sources of mortality are additive, compensatory, or depensatory is a key question in population biology. A way to test for additivity is to calculate the correlation between cause-specific mortality rates obtained from marked animals. However, existing methods to estimate this correlation raise several methodological issues. One difficulty is the existence of an intrinsic bias in the correlation parameter. Although this bias can be formally expressed, it requires knowledge about natural survival without any competing mortality source, which is difficult to assess in most cases. Another difficulty lies in estimating the true process correlation while properly accounting for sampling variation. Using a Bayesian approach, we developed a state-space model to assess the correlation between two competing sources of mortality. By distinguishing the mortality process from its observation through dead recoveries and live recaptures, we estimated the process correlation. To correct for the intrinsic bias, we incorporated experts opinions on natural survival. We illustrated our approach using data on a hunted population of wild boars. Mortalities were not additive and natural mortality increased with hunting mortality likely as a consequence of non-controlled mortality by crippling loss. Our method opens perspectives for wildlife management and for the conservation of endangered species.
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Leisure time activities that predict initiation, progression and reduction of cannabis use: a prospective, population-based panel survey.
Drug Alcohol Rev
PUBLISHED: 07-20-2010
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Frequent cannabis consumption can lead to severe physical and mental harm. As cannabis is often consumed in leisure time, this study aimed at identifying differences in leisure time activities that predicted the severity of cannabis use.
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Patches of bare ground as a staple commodity for declining ground-foraging insectivorous farmland birds.
PLoS ONE
PUBLISHED: 06-22-2010
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Conceived to combat widescale biodiversity erosion in farmland, agri-environment schemes have largely failed to deliver their promises despite massive financial support. While several common species have shown to react positively to existing measures, rare species have continued to decline in most European countries. Of particular concern is the status of insectivorous farmland birds that forage on the ground. We modelled the foraging habitat preferences of four declining insectivorous bird species (hoopoe, wryneck, woodlark, common redstart) inhabiting fruit tree plantations, orchards and vineyards. All species preferred foraging in habitat mosaics consisting of patches of grass and bare ground, with an optimal, species-specific bare ground coverage of 30-70% at the foraging patch scale. In the study areas, birds thrived in intensively cultivated farmland where such ground vegetation mosaics existed. Not promoted by conventional agri-environment schemes until now, patches of bare ground should be implemented throughout grassland in order to prevent further decline of insectivorous farmland birds.
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An assessment of integrated population models: bias, accuracy, and violation of the assumption of independence.
Ecology
PUBLISHED: 04-13-2010
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Understanding population dynamics requires accurate estimates of demographic rates. Integrated population models combine demographic and survey data into a single, comprehensive analysis and provide more coherent estimates of vital rates. Integrated population models rely on the assumption that different data sets are independent, which is frequently violated in practice. Moreover, the precision that can be gained using integrated modeling compared to conventional modeling is only known from empirical studies. The present study used simulation methods to assess how the violation of the assumption of independence affects the statistical properties of the parameter estimators. Further, the gains in precision and accuracy from the model were explored under varying sample sizes. For capture-recapture, population survey, and reproductive success, we generated independent and dependent data that were analyzed with integrated and conventional models. We found only a minimal impact of the violation of the assumption of independence on the parameter estimates. Furthermore, we observed an overall gain in precision and accuracy when all three data sets were analyzed simultaneously. This was particularly pronounced when the sample size was small. These findings contribute to clearing the way for the application of integrated population models in practice.
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Do patients think cannabis causes schizophrenia? - A qualitative study on the causal beliefs of cannabis using patients with schizophrenia.
Harm Reduct J
PUBLISHED: 04-07-2010
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There has been a considerable amount of debate among the research community whether cannabis use may cause schizophrenia and whether cannabis use of patients with schizophrenia is associated with earlier and more frequent relapses. Considering that studies exploring patients view on controversial topics have contributed to our understanding of important clinical issues, it is surprising how little these views have been explored to add to our understanding of the link between cannabis and psychosis. The present study was designed to elucidate whether patients with schizophrenia who use cannabis believe that its use has caused their schizophrenia and to explore these patients other beliefs and perceptions about the effects of the drug.
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Site-occupancy distribution modeling to correct population-trend estimates derived from opportunistic observations.
Conserv. Biol.
PUBLISHED: 03-27-2010
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Species assessments must frequently be derived from opportunistic observations made by volunteers (i.e., citizen scientists). Interpretation of the resulting data to estimate population trends is plagued with problems, including teasing apart genuine population trends from variations in observation effort. We devised a way to correct for annual variation in effort when estimating trends in occupancy (species distribution) from faunal or floral databases of opportunistic observations. First, for all surveyed sites, detection histories (i.e., strings of detection-nondetection records) are generated. Within-season replicate surveys provide information on the detectability of an occupied site. Detectability directly represents observation effort; hence, estimating detectability means correcting for observation effort. Second, site-occupancy models are applied directly to the detection-history data set (i.e., without aggregation by site and year) to estimate detectability and species distribution (occupancy, i.e., the true proportion of sites where a species occurs). Site-occupancy models also provide unbiased estimators of components of distributional change (i.e., colonization and extinction rates). We illustrate our method with data from a large citizen-science project in Switzerland in which field ornithologists record opportunistic observations. We analyzed data collected on four species: the widespread Kingfisher (Alcedo atthis) and Sparrowhawk (Accipiter nisus) and the scarce Rock Thrush (Monticola saxatilis) and Wallcreeper (Tichodroma muraria). Our method requires that all observed species are recorded. Detectability was <1 and varied over the years. Simulations suggested some robustness, but we advocate recording complete species lists (checklists), rather than recording individual records of single species. The representation of observation effort with its effect on detectability provides a solution to the problem of differences in effort encountered when extracting trend information from haphazard observations. We expect our method is widely applicable for global biodiversity monitoring and modeling of species distributions.
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Sex-dependent selection on an autosomal melanic female ornament promotes the evolution of sex ratio bias.
Ecol. Lett.
PUBLISHED: 03-19-2010
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Sex-dependent selection often leads to spectacularly different phenotypes in males and females. In species in which sexual dimorphism is not complete, it is unclear which benefits females and males derive from displaying a trait that is typical of the other sex. In barn owls (Tyto alba), females exhibit on average larger black eumelanic spots than males but members of the two sexes display this trait in the same range of possible values. In a 12-year study, we show that selection exerted on spot size directly or on genetically correlated traits strongly favoured females with large spots and weakly favoured males with small spots. Intense directional selection on females caused an increase in spot diameter in the population over the study period. This increase is due to a change in the autosomal genes underlying the expression of eumelanic spots but not of sex-linked genes. Female-like males produced more daughters than sons, while male-like females produced more sons than daughters when mated to a small-spotted male. These sex ratio biases appear adaptive because sons of male-like females and daughters of female-like males had above-average survival. This demonstrates that selection exerted against individuals displaying a trait that is typical of the other sex promoted the evolution of specific life history strategies that enhance their fitness. This may explain why in many organisms sexual dimorphism is often not complete.
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Year-round tracking of small trans-Saharan migrants using light-level geolocators.
PLoS ONE
PUBLISHED: 02-16-2010
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Since 1899 ringing (or banding) remained the most important source of information about migration routes, stopover sites and wintering grounds for birds that are too small to carry satellite-based tracking systems. Despite the large quantity of migrating birds ringed in their breeding areas in Europe, the number of ring recoveries from sub-Saharan Africa is very low and therefore the whereabouts of most small bird species outside the breeding season remain a mystery. With new miniaturized light-level geolocators it is now possible to look beyond the limits of ring recovery data. Here we show for the first time year round tracks of a near passerine trans-Saharan migrant, the European Hoopoe (Upupa epops epops). Three birds wintered in the Sahel zone of Western Africa where they remained stationary for most of the time. One bird chose a south-easterly route following the Italian peninsula. Birds from the same breeding population used different migration routes and wintering sites, suggesting a low level of migratory connectivity between breeding and wintering areas. Our tracking of a near passerine bird, the European Hoopoe, with light-level geolocators opens a new chapter in the research of Palaearctic-African bird migration as this new tool revolutionizes our ability to discover migration routes, stopover sites and wintering grounds of small birds.
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[Prognostic factors from a long-term follow-up of heroin-assisted treatment in Switzerland 1994-2007].
Psychiatr Prax
PUBLISHED: 02-10-2010
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To identify prognostic factors for a positive or negative termination of heroin-assisted treatment (HAT) in Switzerland.
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Spatial variation in abiotic and biotic factors in a floodplain determine anuran body size and growth rate at metamorphosis.
Oecologia
PUBLISHED: 02-04-2010
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Body size at metamorphosis is a critical trait in the life history of amphibians. Despite the wide-spread use of amphibians as experimental model organisms, there is a limited understanding of how multiple abiotic and biotic factors affect the variation in metamorphic traits under natural conditions. The aim of our study was to quantify the effects of abiotic and biotic factors on spatial variation in the body size of tadpoles and size at metamorphosis of the European common toad (Bufo b. spinosus). Our study population was distributed over the riverbed (active tract) and the fringing riparian forest of a natural floodplain. The riverbed had warm ponds with variable hydroperiod and few predators, whereas the forest had ponds with the opposite characteristics. Spatial variation in body size at metamorphosis was governed by the interactive effects of abiotic and biotic factors. The particular form of the interaction between water temperature and intraspecific tadpole density suggests that abiotic factors laid the foundation for biotic factors: intraspecific density decreased growth only at high temperature. Predation and intraspecific density jointly reduced metamorphic size. Interspecific density had a negligible affect on body size at metamorphosis, suggesting weak inter-anuran interactions in the larval stage. Population density at metamorphosis was about one to two orders of magnitudes higher in the riverbed ponds than in the forest ponds, mainly because of lower tadpole mortality. Based on our results, we conclude that ponds in the riverbed appear to play a pivotal role for the population because tadpole growth and survival is best in this habitat.
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Comparing outcomes of voluntary and quasi-compulsory treatment of substance dependence in Europe.
Eur Addict Res
PUBLISHED: 12-15-2009
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This study evaluates quasi-compulsory drug treatment (QCT) arrangements for substance-dependent offenders receiving treatment instead of imprisonment in comparison to voluntary treatment within five European countries.
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Differential resource selection within shared habitat types across spatial scales in sympatric toads.
Ecology
PUBLISHED: 12-08-2009
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Differential habitat selection is a central component in the evolution of species, but it has been quantified rarely for sympatric species in relation to the multiple impacts of resources at the spatial scales at which animals operate. Our main goal was to quantify the selection of terrestrial summer habitats in a natural floodplain in Italy by two sympatric amphibians (Bufo bufo spinosus and B. viridis) as a function of habitat type, prey density, and temperature. We applied a Bayesian resource selection model at three spatial scales: (1) home range placement within the floodplain, (2) space use within 95% home ranges, and (3) space use within 50% core areas. Using these data we explored whether processes acting at large scales lead to space use patterns at small scales and whether the two species use the same habitat types in a way that would facilitate coexistence. Habitat selection was determined by habitat type, prey density, and temperature at all spatial scales, resulting in slightly higher prey density and significantly lower temperature within than outside home ranges. We conclude that amphibians perceive the distribution of habitat types as well as gradients in prey density and temperature at all spatial scales. The effects of habitat type dominated home range placement while prey density and temperature most strongly affected space use within home ranges. Our results suggest that home range placement relies on broad habitat features that indicate resource availability at small spatial scales. At the smallest spatial scale, the selection of prey and refugia is most probably facilitated due to the accumulation of environmental information as animals may sample the entire area. Both species largely preferred the same habitat types, but used them differently in relation to resources across the three spatial scales. For example, while one species used the same habitat type for foraging, the other used it for resting or both resting and foraging. Niche differentiation through differential resource selection within shared habitat types at all spatial scales may therefore facilitate the coexistence of the two species in terrestrial summer habitats.
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Comparison of bulk sediment and sediment elutriate toxicity testing methods.
Arch. Environ. Contam. Toxicol.
PUBLISHED: 08-28-2009
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Numerous methods exist for assessing the potential toxicity of sediments in aquatic systems. In this study, the results from 10-day bulk sediment toxicity test methods using Hyalella azteca and Chironomus tentans were compared to results from 96-h Pimephales promelas and Ceriodaphnia dubia renewed acute toxicity tests conducted using elutriate samples prepared from the same sediments. The goal of the study was to determine if the results from the elutriate tests were comparable to those obtained from the bulk sediment tests. Of the 25 samples analyzed, 16 were found to be toxic to at least one of the species tested, in either elutriate or bulk sediment tests. The C. tentans 10-day bulk sediment test was the most sensitive, with 12 sediment samples exhibiting toxicity to this species, whereas the H. azteca bulk sediment test and C. dubia 96-h elutriate test were the least sensitive, exhibiting toxicity in only 7 of the 25 sediments tested. The P. promelas elutriate test found 8 of the 25 sediments to be toxic. Based on the total number of sites found to show toxicity, results from testing indicate 96-h elutriate tests show a level of sensitivity comparable to 10-day bulk sediment tests in assessing toxicity quantitatively. However, the methods did not always find toxicity at the same sites, suggesting that the ability of elutriate tests to predict toxicity (quantitatively) is not statistically correlated with bulk sediment methods. This would indicate that a suite of toxicity test methods would provide the most complete measure of site condition; however, in circumstances where bulk sediment testing is not feasible, elutriate tests can provide a practical and credible alternative for toxicity assessment.
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Effect of current reproduction on apparent survival, breeding dispersal, and future reproduction in barn swallows assessed by multistate capture-recapture models.
J Anim Ecol
PUBLISHED: 07-25-2009
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1. Theoretical models predict a negative effect of current reproduction on breeding dispersal, survival and future reproduction, and many studies confirm these predictions. Yet, results of most previous studies may be difficult to interpret because the fate of the affected individuals cannot always be observed. Detection is almost always imperfect and some individuals emigrate from the study area, resulting in biased estimates of both survival and dispersal. 2. Most studies bypass these problems with strong assumptions. We use a multistate capture-recapture model that does not require these assumptions. States are defined based on classes of reproductive success and on observed dispersal events within the study area. By accounting for imperfect detection within the study area, the model allows estimation of the effect of reproductive success on apparent survival, dispersal probabilities within the study area and the annual transition probabilities among classes of reproductive success. Based on an assumption about the estimate of real survival, the model allows the estimation of total dispersal that is not specific to a fixed study area. 3. We applied this model to capture-recapture data of 2262 adult barn swallows (Hirundo rustica) sampled from 1997-2004 in eight local populations in Switzerland. 4. We found that dispersal within the study area decreased with increasing reproductive success in both sexes, that reproductive success was not affected by preceding dispersal and that apparent survival of females but not of males increased with increasing reproductive success. Apparent survival of females with high reproductive success was identical to apparent survival of males suggesting that this estimate of apparent survival (0.48) was close to true survival. Total breeding dispersal was generally higher in females and it increased with decreasing reproductive success in both sexes. Current reproductive success depended on reproductive success in the preceding year suggesting that individual differences were of importance. 5. Our study highlights that reproductive success was an important factor affecting breeding dispersal and population turnover. While unsuccessful males mainly remained in the local populations, many unsuccessful females left them. Population turnover of adult swallows was mainly due to unsuccessful females.
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Feasibility of buprenorphine and methadone maintenance programmes among users of home made opioids in Ukraine.
Int. J. Drug Policy
PUBLISHED: 07-24-2009
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Opioid substitution therapy (OST) in the Ukraine was not provided until 2004. Methadone maintenance therapy only became available in May 2008. Injecting drug users in Ukraine are predominantly injecting self-made opioid solution (Shirka). A feasibility study on buprenorphine and methadone maintenance treatment was conducted in 2008.
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Variation of adult survival drives population dynamics in a migrating forest bat.
J Anim Ecol
PUBLISHED: 06-22-2009
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1. Variation of survival across time, between sex and ages strongly affect the population dynamics of long-lived species. Bats are extremely long-lived, but the variation of their survival probabilities is poorly studied with reliable methods. 2. We studied annual local survival probabilities of the migratory Leislers bats Nyctalus leisleri based on capture-recapture data from 1119 individuals sampled in bat boxes over 20 years in eastern Germany. We assessed variation in survival between sex and age classes, estimated the temporal variance of survival and tested whether survival was affected by weather during hibernation or pregnancy. 3. Among females, our analyses revealed two groups of individuals present with different roosting occupancy, survival and/or dispersal. Local survival of locally born females increased with age [first year: 0.45 +/- 0.04 (SE); later: 0.76 +/- 0.04] and the high recapture probabilities indicate regular presence in the roosts. Recapture probabilities and local survival of foreign adult females were significantly lower, indicating less frequent presence in the roosts and stronger dispersal from the study area. 4. In adult males, locally born and foreign individuals were nearly identical regarding survival and recapture, indicating a more homogenous group. Local survival was very low in the first year (0.04 +/- 0.08), most likely caused by strong natal dispersal. It further increased with age (second year: 0.55 +/- 0.20, later: 0.69 +/- 0.07). 5. Survival probabilities of all females varied significantly and in parallel across time, suggesting that a common environmental factor was operating which affected all individuals similarly. Spring temperature and winter North Atlantic Oscillation explained maximally 9% each of the variation in first year and adult female survival. In contrast to our expectations, the temporal variance of first-year survival was lower than that of adult survival. 6. We found evidence of a complicated social population structure of female Leislers bats. Our analyses suggest that their population dynamics are driven to a large amount by variation of survival, in particular by adult survival. The reason for the major temporal variations remains to be identified.
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Feasibility of buprenorphine maintenance therapy programs in the Ukraine: first promising treatment outcomes.
Eur Addict Res
PUBLISHED: 05-07-2009
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Opiate substitution therapy (OST) in the Ukraine was not provided until 2004. As part of the introduction of OST, the first feasibility study was conducted in 2007. Six clinics in 6 cities were involved in providing OST and collecting data.
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Web-based cognitive behavioral self-help intervention to reduce cocaine consumption in problematic cocaine users: randomized controlled trial.
J. Med. Internet Res.
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Web-based self-help programs that reduce problematic substance use are able to reach hidden consumer groups in the general population. These programs are characterized by their low treatment threshold and nonrestrictive intervention settings. They are also cost effective, making them of interest to both low-income and high-income industrialized countries with ever-increasing health costs.
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Multidimensional family therapy lowers the rate of cannabis dependence in adolescents: a randomised controlled trial in Western European outpatient settings.
Drug Alcohol Depend
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Noticing a lack of evidence-based programmes for treating adolescents heavily using cannabis in Europe, government representatives from Belgium, France, Germany, The Netherlands, and Switzerland decided to have U.S.-developed multidimensional family therapy (MDFT) tested in their countries in a trans-national trial, called the International Need for Cannabis Treatment (INCANT) study.
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Conservation through connectivity: can isotopic gradients in Africa reveal winter quarters of a migratory bird?
Oecologia
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Conservation of migratory wildlife requires knowledge of migratory connectivity between breeding and non-breeding locations. Stable isotopes in combination with geographical isotopic patterns (isoscapes) can provide inferences about migratory connectivity. This study examines whether such an approach can be used to infer wintering areas in sub-Saharan Africa, where we lack such knowledge for many species, but where this method has not been used widely. We measured ? (2)H, ? (13)C and ? (15)N in winter-grown feathers of a breeding Swiss and Spanish population of European hoopoe Upupa epops--a typical Palaearctic-Afrotropical migrant. ? (2)H values predicted that ~70 % of the hoopoes spent the non-breeding season in the western portion of their potential winter range. This was corroborated by a shallow east-west gradient in feather-? (2)H values of museum specimens from known African origin across the potential winter range and by the recovery of Swiss hoopoes marked with geolocators. Hoopoes categorized as from eastern versus western regions of the wintering range were further delineated spatially using feather ? (13)C and ? (15)N. ? (15)N showed no trend, whereas adults were more enriched in (13)C in the western portion of the range, with eastern adults being in addition more depleted in (13)C than eastern juveniles. This suggests that eastern juveniles may have occupied more xeric habitats than sympatric adults. We demonstrated that stable isotopes, especially ? (2)H, could only very roughly delineate the winter distribution of a trans-Saharan Palaearctic migrant restricted primarily to the Sahelian and savanna belt south of the Sahara. Further refinements of precipitation isoscapes for Africa as well the development of isoscapes for ? (13)C and ? (15)N may improve assignment of this and other migrants.
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Encoding dynamics for multiscale community detection: Markov time sweeping for the map equation.
Phys Rev E Stat Nonlin Soft Matter Phys
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The detection of community structure in networks is intimately related to finding a concise description of the network in terms of its modules. This notion has been recently exploited by the map equation formalism [Rosvall and Bergstrom, Proc. Natl. Acad. Sci. USA 105, 1118 (2008)] through an information-theoretic description of the process of coding inter- and intracommunity transitions of a random walker in the network at stationarity. However, a thorough study of the relationship between the full Markov dynamics and the coding mechanism is still lacking. We show here that the original map coding scheme, which is both block-averaged and one-step, neglects the internal structure of the communities and introduces an upper scale, the "field-of-view" limit, in the communities it can detect. As a consequence, map is well tuned to detect clique-like communities but can lead to undesirable overpartitioning when communities are far from clique-like. We show that a signature of this behavior is a large compression gap: The map description length is far from its ideal limit. To address this issue, we propose a simple dynamic approach that introduces time explicitly into the map coding through the analysis of the weighted adjacency matrix of the time-dependent multistep transition matrix of the Markov process. The resulting Markov time sweeping induces a dynamical zooming across scales that can reveal (potentially multiscale) community structure above the field-of-view limit, with the relevant partitions indicated by a small compression gap.
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From metamorphosis to maturity in complex life cycles: equal performance of different juvenile life history pathways.
Ecology
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Performance in one stage of a complex life cycle may affect performance in the subsequent stage. Animals that start a new stage at a smaller size than conspecifics may either always remain smaller or they may be able to "catch up" through plasticity, usually elevated growth rates. We study how size at and date of metamorphosis affected subsequent performance in the terrestrial juvenile stage and lifetime fitness of spadefoot toads (Pelobates fuscus). We analyzed capture-recapture data of > 3000 individuals sampled during nine years with mark-recapture models to estimate first-year juvenile survival probabilities and age-specific first-time breeding probabilities of toads, followed by model selection to assess whether these probabilities were correlated with size at and date of metamorphosis. Males attained maturity after two years, whereas females reached maturity 2-4 years after metamorphosis. Age at maturity was weakly correlated with metamorphic traits. In both sexes, first-year juvenile survival depended positively on date of metamorphosis and, in males, also negatively on size at metamorphosis. In males, toads that metamorphosed early at a small size had the highest probability to reach maturity. However, because very few toadlets metamorphosed early, the vast majority of male metamorphs had a very similar probability to reach maturity. A matrix projection model constructed for females showed that different juvenile life history pathways resulted in similar lifetime fitness. We found that the effects of date of and size at metamorphosis on different juvenile traits cancelled each other out such that toads that were small or large at metamorphosis had equal performance. Because the costs and benefits of juvenile life history pathways may also depend on population fluctuations, ample phenotypic variation in life history traits may be maintained.
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Group hypnotherapy versus group relaxation for smoking cessation: an RCT study protocol.
BMC Public Health
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A significant number of smokers would like to stop smoking. Despite the demonstrated efficacy of pharmacological smoking cessation treatments, many smokers are unwilling to use them; however, they are inclined to try alternative methods. Hypnosis has a long-standing reputation in smoking cessation therapy, but its efficacy has not been scientifically proven. We designed this randomised controlled trial to evaluate the effects of group hypnosis as a method for smoking cessation, and we will compare the results of group hypnosis with group relaxation.
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Markov dynamics as a zooming lens for multiscale community detection: non clique-like communities and the field-of-view limit.
PLoS ONE
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In recent years, there has been a surge of interest in community detection algorithms for complex networks. A variety of computational heuristics, some with a long history, have been proposed for the identification of communities or, alternatively, of good graph partitions. In most cases, the algorithms maximize a particular objective function, thereby finding the right split into communities. Although a thorough comparison of algorithms is still lacking, there has been an effort to design benchmarks, i.e., random graph models with known community structure against which algorithms can be evaluated. However, popular community detection methods and benchmarks normally assume an implicit notion of community based on clique-like subgraphs, a form of community structure that is not always characteristic of real networks. Specifically, networks that emerge from geometric constraints can have natural non clique-like substructures with large effective diameters, which can be interpreted as long-range communities. In this work, we show that long-range communities escape detection by popular methods, which are blinded by a restricted field-of-view limit, an intrinsic upper scale on the communities they can detect. The field-of-view limit means that long-range communities tend to be overpartitioned. We show how by adopting a dynamical perspective towards community detection [1], [2], in which the evolution of a Markov process on the graph is used as a zooming lens over the structure of the network at all scales, one can detect both clique- or non clique-like communities without imposing an upper scale to the detection. Consequently, the performance of algorithms on inherently low-diameter, clique-like benchmarks may not always be indicative of equally good results in real networks with local, sparser connectivity. We illustrate our ideas with constructive examples and through the analysis of real-world networks from imaging, protein structures and the power grid, where a multiscale structure of non clique-like communities is revealed.
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An interlaboratory comparison of sediment elutriate preparation and toxicity test methods.
Environ Monit Assess
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Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-h Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conducted independently by two laboratories using elutriate samples prepared from the same sediment. The goal of the study was to determine if the results from the elutriate tests were comparable between two U.S. Environmental Protection Agency (USEPA) laboratories when different elutriate preparation procedures were employed by each lab. Complete agreement in site characterization was attained in 22 of the 25 samples for both bioassays amongst each lab. Of the 25 samples analyzed, 10 were found to be toxic to at least one of the species tested by either laboratory. The C. dubia elutriate tests conducted by the National Exposure Research Laboratory (NERL) indicated that 7 of the 25 sediment samples were toxic, while 8 sediment samples were characterized as such in testing conducted by USEPA Region 6 (Region 6). The P. promelas elutriate tests conducted by NERL determined 8 samples as toxic, while Region 6 tests displayed toxicity in 5 of the samples. McNemars test of symmetry for C. dubia (S?=?0.33, p?=?0.5637) and P. promelas (S?=?3.0, p?=?0.0833) tests indicated no significant differences in designating a site toxic between NERL and Region 6 laboratories. Likewise, Cohens kappa test revealed significant agreement between NERL and Region 6 C. dubia (K?=?0.7148, p?
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.