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PubMed2026

Precision targeting of teacher burnout using network-informed ecological momentary interventions.

Teacher well-being affects classroom functioning and workforce stability, yet generic digital programs rarely use person-specific affect dynamics to select support. This cluster-randomised trial evaluated whether micro-interventions selected from high expected influence (EI) nodes in teachers' contemporaneous affect networks produced larger changes in burnout-related EI and everyday happiness than content-matched random allocation. The objectives were to estimate allocation effects on changes in estimated network summaries and happiness, evaluate network change as a statistical mediator, examine personality moderation, and benchmark simpler allocation rules. A two-arm cluster randomised platform trial was conducted in 84 public schools across four urban districts in H Province. After a 14 day baseline of ecological momentary assessment (EMA), person specific partial correlation networks were estimated for happiness, exhaustion, detachment, efficacy and rumination. An optimisation engine prioritised three brief micro-intervention types per teacher according to baseline EI, while the active control received the same library without network information. EMA continued for 8 weeks; Bayesian multilevel models, permutation-based mediation, and benchmarking analyses were applied. EI-based targeting produced larger reductions in the composite EI-change index than active control (mean difference 0.11, 95% credible interval 0.08 to 0.14) and higher week 7 EMA happiness (4.4 points on a 0 to 100 scale, 95% credible interval 2.7 to 6.0), with a positive arm by week slope difference of 0.62 points per week (95% credible interval 0.39 to 0.85). Model-based mediation estimates were consistent with approximately one half of the happiness difference being statistically associated with change in the composite EI-change index (average conditional mediation estimate 3.5 points, 95% credible interval 2.0 to 5.2). Benchmarking showed smaller gains under severity, threshold, or group-level centrality rules. Effects were stronger among teachers higher in conscientiousness. The findings indicate that integrating EMA, network modelling, and EI-driven optimisation yields measurable gains beyond content-matched exposure, providing a proof of concept for district-scale precision mental health that requires prospective implementation testing. Replication in additional regions, expanded node sets, and longer follow up are warranted to assess durability and generalisability.

Female↗
PubMed2006

Exploring candidate genes for human brain diseases from a brain-specific gene network.

It is believed that large numbers of genes are involved in common human brain diseases. Here, we propose a novel computational strategy for simultaneously identifying multiple candidate genes for genetic human brain diseases from a brain-specific gene network-level perspective. By integrating diverse genomic and proteomic datasets based on Bayesian statistical model, we built a large-scale human brain-specific gene network. Based on this network and minor prior knowledge of a specific brain disease, we can effectively identify multiple candidate genes for this disease. When four known Alzheimer's disease genes were used as the prior knowledge, among the top 46 high-scoring genes that we have found, 37 were previously reported to be associated with Alzheimer's disease. And the higher score a gene has, the more likely this gene is a disease-related one. The results suggest that the proposed method is effective, convenient, and applicable in the future genetic studies.

Alzheimer Disease↗
PubMed2005

A probabilistic approach to the joint evaluation of firearm evidence and gunshot residues.

The present paper addresses issues that affect both the separate as well as the joint evaluation of firearm evidence (i.e., marks) and gunshot residues (GSR). Mark evidence will be used as a basis to discriminate among barrels through which a bullet in question might have been shot whereas GSR will be used to draw inferences about the distance of firing. Particular attention is drawn to the coherent handling of uncertainties associated with the various parameters considered within each item of evidence. The proposed analysis relies on a probabilistic viewpoint that uses graphical models (i.e., Bayesian networks) as an aid to cope with the complexity induced by the number of variables considered. The paper discusses how an approach based on a probabilistic network environment can be used for the formal analysis and construction of arguments. Emphasis is made on the gain of insight into structural dependencies that may be uncovered when the evaluative process is extended beyond single items of scientific evidence.

Bayes Theorem↗
PubMed2005

Risk factors and spatial patterns of hookworm infection among schoolchildren in a rural area of western Côte d'Ivoire.

This study is aimed at investigating the risk factors for hookworm infection among schoolchildren in a rural area of western Côte d'Ivoire and predicting and mapping the spatial distribution of infection. We used demographic and socio-economic data from a cross-sectional survey of 6-16-year-old schoolchildren from 56 schools. Infection with hookworm was determined by microscopic examination of stool samples employing the Kato-Katz technique and an ether-concentration method. Environmental data were derived from satellite images and digitised maps. Bayesian variogram models were applied to investigate the variation of hookworm infection in relation to demographic, socio-economic and environmental factors. The overall hookworm infection prevalence, based on the pooled microscopic diagnoses, was 43.3% and ranged from 5.4 to 79.1% in the schools surveyed. Bivariate analyses showed that sex, age, socio-economic status, elevation, rainfall and land cover were significantly associated with the spatial distribution of hookworm infection. The final multivariate spatial model consisted of the covariates age, sex, socio-economic status, elevation and land cover. When assuming non-stationary underlying spatial dependency, the results of the model suggested that spatial correlation depended on the location only marginally. We conclude that, at the current resolution, it seems more reasonable to target interventions based on well-established epidemiologic risk factors, rather than on spatial factors.

Adolescent↗
PubMed2006

Bayesian estimation of community prevalences of Schistosoma japonicum infection in China.

A Bayesian approach to overcome the imperfections of an immunological test (an antibody-based ELISA) and a parasitological test (Kato-Katz) in the detection of Schistosoma japonicum infection, was used to estimate community prevalences of S. japonicum infection in China. At the same time, the similarity between the prevalence estimates based on data from ELISA alone and those using data from both ELISA and Kato-Katz tests was explored. The database from the third nationwide sampling survey of schistosomiasis in China, 2004, was used for analysis, in which a total of 239 endemic villages were sampled from seven endemic provinces through a stratified cluster sampling technique and 250,987 residents aged from 6 to 65 years, were examined by ELISA followed by a Kato-Katz test applied to the seropositives. Bayesian hierarchical models incorporating random effects to reflect the nested data structure and uncertainty about test properties were employed to analyse the data. Our analysis suggested that using data from ELISA alone or both ELISA and Kato-Katz tests resulted in similar prevalence estimates, probably owing to the lack of sensitivity of Kato-Katz and the fact that Kato-Katz was only applied to the seropositives. We conclude that it is feasible to employ only ELISA, instead of combined ELISA and Kato-Katz tests, to estimate prevalence of S. japonicum infection in large-scale epidemiological settings. This study confirmed heterogeneity in the prevalence of S. japonicum infection in space by the fact that the estimated prevalences of S. japonicum infection in the sampled villages ranged from 0.02% to about 56% (posterior median). It is indicated that the disease remains a threat in some areas along the Yangtze River, although great achievements have been made in the control programme of schistosomiasis in China.

Adolescent↗
PubMed2004

Investigation of new complete denture quality and patients' satisfaction with and use of dentures after two years.

OBJECTIVES: To investigate if clinical quality of new complete dentures predicts patient satisfaction with and usage of those dentures two years after insertion in the same way that it did initially and three months after insertion. METHODS: Four hundred and seventeen patients recruited to a denture outcome study two years previously were surveyed. In each case aspects of denture quality had previously been rated according to a validated method at the first post-insertion visit and patients had completed a postal questionnaire three months after denture insertion. When the dentures were two years old, patients were sent another postal questionnaire to assess denture usage and satisfaction with the dentures. RESULTS: The response rate to the postal survey was 87%. Data were analysed using structural equation modelling and Bayesian belief networks. No significant associations were found between aspects of new denture quality and patient satisfaction with and use of complete dentures after two years. These results contrast with the three month returns from the same patients that demonstrated significant associations between new denture quality and satisfaction with and use of new complete dentures. CONCLUSIONS: The authors conclude that initial clinical quality of new complete dentures is not a significant factor in determining patients' satisfaction with and use of these complete dentures two years after insertion.

Aged↗
PubMed2006

Bayesian analysis of population structure based on linked molecular information.

The Bayesian model-based approach to inferring hidden genetic population structures using multilocus molecular markers has become a popular tool within certain branches of biology. In particular, it has been shown that heterogeneous data arising from genetically dissimilar latent groups of individuals can be effectively modelled using an unsupervised classification formulation. However, most currently employed models ignore potential linkage within the employed molecular information, and can therefore lead to biased inferences under certain circumstances. Utilizing the general theory of graphical models, we develop a framework that accounts for dependences both within linked molecular marker loci and DNA sequence data. Due to a high level of sequence conservation among eukaryotic species, the latter aspect is particularly relevant for analyzing rapidly evolving microbial species. The advantages of incorporating the dependence due to linkage in the classification models are illustrated by analyses of both simulated data and real samples of Bacillus cereus.

Bacillus cereus↗
PubMed2006

A genetically diverse but distinct North American population of Sarcocystis neurona includes an overrepresented clone described by 12 microsatellite alleles.

The population genetics and systematics of most coccidians remain poorly defined despite their impact on human and veterinary health. Non-recombinant parasite clones characterized by distinct transmission and pathogenesis traits persist in the coccidian Toxoplasma gondii despite opportunities for sexual recombination. In order to determine whether this may be generally true for tissue-cyst forming coccidia, and to address evolutionary and taxonomic problems within the genus Sarcocystis, we characterized polymorphic microsatellite markers in Sarcocystis neurona, the major causative agent of equine protozoal myeloencephalitis (EPM). Bayesian statistical modeling, phylogenetic reconstruction based on genotypic chord distances, and analyses of linkage disequilibrium were employed to examine the population structure within S. neurona and closely related Sarcocystis falcatula isolates from North and South America. North American S. neurona were clearly differentiated from those of South America and also from isolates of S. falcatula. Although S. neurona is characterized by substantial allelic and genotypic diversity typical of interbreeding populations, one genotype occurs with significantly excessive frequency; thus, some degree of asexual propagation of S. neurona clones may naturally occur. Finally, S. neurona isolated from disparate North American localities and diverse hosts (opossums, a Southern sea otter, and horses) comprise a single genetic population. Isolates associated with clinical neurological disease bear no obvious distinction as measured by these presumably neutral genetic markers.

Animals↗
PubMed2005

Area-level risks for BSE in British cattle before and after the July 1988 meat and bone meal feed ban.

In this paper we investigate area-level risk factors for BSE for the cattle population present in Great Britain between 1986 and 1997. By dividing this population into two birth cohorts, those born before the July 1988 ban on feeding ruminant-derived meat and bone meal to ruminants and those born after, second-order regional influences are distinguished from the strong first-order south-to-north gradient of area-level BSE risk using Bayesian hierarchical models that account for structured (spatially correlated) and unstructured heterogeneity in the data. For both cohorts area-level risk of BSE was increased by a more southerly location and greater numbers of dairy cattle, relative to non-dairy cattle. For the cohort of cattle born after the July 1988 ban on feeding ruminant-derived meat and bone meal area-level BSE risk was additionally associated with greater numbers of pigs, relative to cattle. These findings support the role of low level cross-contamination of cattle feed by pig feed as an influence on BSE incidence risk as the epidemic evolved. Prior to the 1988 meat and bone meal ban unexplained BSE risk was relatively uniformly distributed across the country whereas after the ban there were spatially aggregated areas of unexplained risk in the northern and eastern regions of England suggesting that local influences allowed BSE control measures to be less-successfully applied in these areas, compared with the rest of the country. We conclude that spatially localised influences were operating in divergent ways during the two phases of the epidemic.

Animal Feed↗
PubMed1996

Choroid plexus cysts and trisomy 18: risk modification based on maternal age and multiple-marker screening.

Choroid plexus cysts are more common in fetuses with chromosomal aneuploidies, particularly trisomy 18. Although it is accepted that the risk of karyotypic abnormality justifies amniocentesis when associated abnormalities are present, disagreement continues as to the risk of trisomy 18 in a fetus with an isolated choroid plexus cyst. We propose consideration of maternal age and multiple-marker screening for chromosomal aneuploidy in the assessment of risk. Bayesian statistical modeling was used to calculate the risk of trisomy 18 from age-related risk figures for trisomy 18 and the incidence of isolated choroid plexus cysts in fetuses with trisomy 18. The risk was further modified on the basis of the ability of multiple-marker screening to detect fetuses with trisomy 18. From risk estimates calculated across maternal ages 20 to 45 years, the risk of trisomy 18 does not approach that of amniocentesis until a maternal age of > or = 37 years. Therefore in the presence of an isolated choroid plexus cyst and normal multiple-marker screen results amniocentesis is justified only in the patient with advanced maternal age.

Adult↗
PubMed1996

The CYP2D6 genotype predicts the oral clearance of the neuroleptic agents perphenazine and zuclopenthixol.

BACKGROUND: Most antidepressant and neuroleptic agents are metabolized by the polymorphic cytochrome P450 enzyme CYP2D6. This study evaluates the importance of the CYP2D6 genotype for the disposition of the neuroleptic agents perphenazine and zuclopenthixol. METHODS: Patients treated with neuroleptic agents (n = 36) were studied prospectively with regard to CYP2D6 genotype and neuroleptic plasma concentration during oral treatment. Because no patient provided enough samples for individual kinetic modeling, a bayesian approach was used for determination of the clearance. Population kinetic parameters for this procedure were collected from retrospective therapeutic drug monitoring data (n = 113) by use of a nonparametric approach. RESULTS: The CYP2D6 genotype significantly predicted the oral clearance of perphenazine and zuclopenthixol (p < 0.01 by multiple regression). The difference in clearance between homozygous extensive metabolizers and poor metabolizers was threefold for perphenazine and twofold for zuclopenthixol. CONCLUSION: The results show that the genotype for CYP2D6 is closely related to the oral clearances of perphenazine and zuclopenthixol. If this finding can be confirmed in a larger population, genotyping may become an important tool for the dosing of these two neuroleptic agents.

Administration, Oral↗
PubMed2001

Predicting secondary progression in relapsing-remitting multiple sclerosis: a Bayesian analysis.

With the aid of a Bayesian statistical model of the natural course of relapsing remitting Multiple Sclerosis (MS), we identify short-term clinical predictors of long-term evolution of the disease, with particular focus on predicting onset of secondary progressive course (failure event) on the basis of patient information available at an early stage of disease. The model specifies the full joint probability distribution for a set of variables including early indicator variables (observed during the early stage of disease), intermediate indicator variables (observed throughout the course of disease, prefailure) and the time to failure. Our model treats the intermediate indicators as a surrogate response event, so that in right-censored patients, these indicators provide supplementary information pointing towards the unobserved failure times. Moreover, the full probability modelling approach allows the considerable uncertainty which affects certain early indicators, such as the early relapse rates, to be incorporated in the analysis. With such a model, the ability of early indicators to predict failure can be assessed more accurately and reliably, and explained in terms of the relationship between early and intermediate indicators. Moreover, a model with the aforementioned features allows us to characterize the pattern of disease course in high-risk patients, and to identify short-term manifestations which are strongly related to long-term evolution of disease, as potential surrogate responses in clinical trials. Our analysis is based on longitudinal data from 186 MS patients with a relapsing-remitting initial course. The following important early predictors of the time to progression emerged: age; number of neurological functional systems (FSs) involved; sphincter, or motor, or motor-sensory symptoms; presence of sequelae after onset. During the first 3 years of follow up, to reach EDSS> or =4 outside relapse, to have sphincter or motor relapses and to reach moderate pyramidal involvement were also found to be unfavourable prognostic factors.

Age of Onset↗
PubMed1998

Reducing the incidence of epileptic seizures in the Belgian Tervuren through selection.

There is growing evidence that idiopathic epilepsy in the Belgium Tervuren has a genetic foundation. Reducing the incidence of this disorder, which may afflict as much as 17% of the breed, will rely upon the wise selection of parents. Seizure data on 997 dogs from the American Belgian Tervuren Club were collected through questionnaires in which animals were classified into one of four mutually exclusive categories: 1) no seizures observed, 2) one seizure observed, 3) two to five seizures, and 4) more than five seizures. The analysis of this ordered data made use of a threshold model of Bayesian inference. Integration of posterior densities was accomplished through Gibbs sampling. Through this analysis we are able to predict that the offspring of the mating of two non-epileptic dogs has a probability of 0.99 of never suffering from a seizure. The offspring of the mating of two dogs who have each had 1 seizure has a predicted probability 0.58 of never suffering from a seizure. Prevention of this disease is best prescribed through the selection of non-epileptic dogs as parents of future generations.

Animals↗
PubMedDate not supplied

[Space-time distribution of suicide in Galicia, Spain [1976-1998]].

OBJECTIVE: To study the space-time distribution of suicide in Galicia from 1976 to 1998, taking into account gender, age, season and method of suicide. METHODS: For each sex crude and age-adjusted rates per province and age-specific rates per period (1978-84, 1985-91, 1992-98) were calculated. To estimate mortality risk and time trends in the municipalities, a Bayesian hierarchical model was used. RESULTS: In the last few years mortality from suicide has increase considerably. Age-adjusted rates of 6 per 105 at the beginning of the study rose to 10 per 105 at the end. The increase was greatest among men. The higher rates were observed in the elderly, although in terms of time trends the highest increase occurred among adolescents and young adults. In both sexes the main method of suicide was hanging. Less common methods were jumping from a height and shooting. The greatest number of suicides took place during the spring and summer months. In terms of spatial distribution, a high number of suicides were committed in the province of Lugo; in the municipalities, mortality risk decreased from North to South and an inverse temporal trend was observed in both sexes. This differed from the space-time patterns of suicides committed using methods other than hanging. CONCLUSIONS: Suicide is an important health problem in Galicia not only because to its magnitude but also because of the increasing rates, especially among young people. Geographical and temporal analysis can identify priority areas where preventive policies should be implemented.

Adolescent↗
PubMed1993

[Computer-assisted intravenous anesthesia: value, method and use].

Total intravenous anaesthesia (TIVA) is becoming increasingly popular among anaesthetists. It has several advantages, namely each component of the anaesthetic protocol can be independently controlled, and the operating room remains unpolluted with nitrous oxide or volatile anaesthetic agents. TIVA aims to maintain a constant blood concentration of each anaesthetic agent. This means that infusion rates need to be repeatedly altered. A computer calculates theoretical blood concentrations of agent according to a pharmacokinetic model, and drives an infusion device. Only a few programmes have been developed by research teams. No commercial device is available as yet. However, there are several syringe pumps and volumetric pumps which are accurate enough for use in TIVA and which may be controlled by computer. Clinical studies have shown the benefits of TIVA: greater haemodynamic stability, decreased drug consumption, more rapid recovery, and a lesser need for postoperative ventilatory support. The most appropriate agents are propofol and etomidate as hypnotics, alfentanil and sufentanil for opioids, vecuronium and atracurium as muscle relaxants. Etomidate is not recommended for prolonged infusions, because of the risk of adrenocortical suppression. TIVA seems to be attractive for neurosurgery, thoracic surgery, day case surgery, endoscopic procedures, and anaesthesia in remote locations. Unfortunately, it is an expensive technique. Moreover, there is considerable interpatient variability of the drug concentration required for a same clinical effect. Two methods are proposed to decrease this variability: population pharmacokinetic models and Bayesian forecasting. Closed loop systems are still research tools. It is concluded that computer-driven anaesthesia is the equivalent to the vaporizer for volatile agents. However, further clinical studies are needed to determine whether the advantages of this technique outweigh its disadvantages.

Analgesics, Opioid↗
PubMed2005

Spatial risk prediction and mapping of Schistosoma mansoni infections among schoolchildren living in western Côte d'Ivoire.

The objectives of this study were (1) to examine risk factors for Schistosoma mansoni infection among schoolchildren living in western Côte d'Ivoire, and (2) to carry forward spatial risk prediction and mapping at non-sampled locations. First, demographic and socio-economic data were obtained from 3818 children, aged 6-16 years, from 55 schools. Second, a single stool sample was examined from each child by the Kato-Katz technique to assess infection status of S. mansoni and its intensity. Third, remotely sensed environmental data were derived from satellite imagery and digitized ground maps. With these databases a comprehensive geographical information system was established. Bayesian variogram models were applied for spatial risk modelling and prediction. The infection prevalence of S. mansoni was 38.9%, ranging from 0% to 89.3% among schools. Results showed that age, sex, the richest wealth quintile, elevation and rainfall explained the geographical variation of the school prevalences of S. mansoni infection. The goodness of fit of different spatial models revealed that age, sex and socio-economic status had a stronger influence on infection prevalence than environmental covariates. The generated risk map can be used by decision-makers for the design and implementation of schistosomiasis control in this setting. If successfully validated elsewhere, this approach can guide control programmes quite generally.

Adolescent↗
PubMed2006

Bayesian geostatistical prediction of the intensity of infection with Schistosoma mansoni in East Africa.

A Bayesian geostatistical model was developed to predict the intensity of infection with Schistosoma mansoni in East Africa. Epidemiological data from purpose-designed and standardized surveys were available for 31,458 schoolchildren (90% aged between 6 and 16 years) from 459 locations across the region and used in combination with remote sensing environmental data to identify factors associated with spatial variation in infection patterns. The geostatistical model explicitly takes into account the highly aggregated distribution of parasite distributions by fitting a negative binomial distribution to the data and accounts for spatial correlation. Results identify the role of environmental risk factors in explaining geographical heterogeneity in infection intensity and show how these factors can be used to develop a predictive map. Such a map has important implications for schisosomiasis control programmes in the region.

Adolescent↗
PubMed2004

A phylogenetic study of the Lecanora rupicola group (Lecanoraceae, Ascomycota).

A molecular phylogeny of the Lecanora rupicola group is presented, based on ITS sequence analyses. The study includes saxicolous and corticolous members of the Lecanora rupicola group as well as other Lecanora species with pruinose apothecia. A phylogenetic hypothesis for species in Lecanora s. lat. and various other genera in Lecanoraceae, based on an alignment-free distance estimation technique, shows that the Lecanora rupicola group forms a monophyletic clade within Lecanoraceae. Affinities to the core group of Lecanora are not well supported, likewise the monophyly of Lecanora s. str. with other species groups in Lecanora, such as the lobate taxa (and Rhizoplaca) is not supported. A more detailed analysis involving Lecanora species with pruinose apothecial discs was carried out with model-based Bayesian Markov chain Monte Carlo (B/MCMC) tree sampling. The results suggest the monophyly of the Lecanora species that are characterized by the presence of chromones. Corticolous as well as saxicolous species are included. Lepraria flavescens is closely related to the Lecanora swartzii subgroup, and the new name Lecanora rouxii nom. nov. is introduced for that species. Other Lecanora species with pruinose discs are not closely related to the Lecanora rupicola group.

Ascomycota↗