Idiographic Ising and Divide and Color Models: Encompassing Networks for Heterogeneous Binary Data.

The Ising model is a graphical model that has played an essential role in network psychometrics. It has been used as a theoretical model to conceptualize psychological concepts and as a statistical model to analyze psychological data. Using graphical models such as the Ising model to analyze psychological data has been heavily critiqued since these data often come from cross-sectional applications. An often voiced concern is the inability of the Ising model to express heterogeneity in the population. The idiographic approach has been posed as an alternative and aims to infer individual network structures. While idiographic networks overcome population heterogeneity, it is unclear how they aggregate into established cross-sectional phenomena. This paper establishes a formal bridge between idiographic and cross-sectional network approaches of the Ising model. We ascertain unique topological structures that characterize individuals and aggregate into an Ising model cross-sectionally. This new formulation supports population heterogeneity while being consistent with cross-sectional phenomena. The proposed theory also establishes a new statistical framework for analyzing populations of idiographic networks for binary variables. The Ising model and the divide and color model are special cases of this new framework. We introduce a Gibbs sampling algorithm to estimate models from this new framework.

Performance of the VITEK®2 advanced expert system™ for the validation of antimicrobial susceptibility testing results.

Time to reporting antimicrobial susceptibility testing (AST) results to physicians plays an essential role in antibiotic stewardship programs. Expert software has been developed for facilitating the microbiologists' AST review process. The reliability of the VITEK®2 Advanced Expert™ software to effectively alert the microbiologist in detection of atypical and inconsistent AST results was assessed at the Labor Berlin-Charité Vivantes services. The results demonstrated a confidence rate of 99.3% in reporting fully consistent AST results to physicians.

Assessment of practical tasks in the Phantom course of Conservative Dentistry by pre-defined criteria: a comparison between self-assessment by students and assessment by instructors.

INTRODUCTION: Assessment of practical skills in undergraduate dental education has difficulties, including a lack of transparency/objectivity in student evaluations. This prospective study investigated whether agreement between student- and faculty-based assessments increased when students were trained to use the assessment criteria. MATERIALS AND METHODS: Assessment criteria were available for 6 tasks in the Phantom course of Conservative Dentistry: Class II cavity preparation, composite restoration, gold and ceramic partial crown preparation, trepanation and access cavity preparation, and root canal filling. Forty-two students were allocated to three different assessment training groups. Students' self-assessments of practical tests were compared with instructors' assessments, depending on training intensity and task type (Pearson's rho, ANOVA, Tukey's post hoc test, Kruskal-Wallis test). Students/instructors were questioned regarding benefits/drawbacks of the criteria. RESULTS: Student self-assessments showed either consent (24.2%), overestimation (31%) or underestimation (44.8%). Gender differences were negligible. Regarding passing/failing grades, more intensive training yielded significantly increased agreement only for preparation of gold partial crowns (rho = +0.313, P = 0.044). Ratings exhibited significant differences amongst tasks (P = 0.002), for example, trepanation assessment had significantly lower differences than gold or ceramic preparation assessments. These discrepancies decreased with increased training. Students consistently reported benefitting most from learning the criteria for gold preparations, followed by composite and ceramic preparations. They also reported that learning the criteria was beneficial for knowledge transfer/feedback. Instructors rated the criteria as helpful for task evaluation and feedback efficiency. CONCLUSIONS: Pre-defined assessment criteria may increase consistency between student self-assessment and instructor assessment depending on the task, improving transparency and feedback in dental education.

Exploring the mechanisms underlying increased risk of depressive disorder in ethnic minority populations in Europe: A causal loop diagram.

BACKGROUND: Multiple ethnic minority populations in Europe show high risk of major depressive disorder (MDD), with ethnic discrimination and low socioeconomic position (SEP) as established risk factors. How this risk is shaped by the interactions between these, and other social factors, remains to be elucidated. We aimed to develop a causal-loop diagram (CLD) to gain a better understanding of how factors at the intersection of ethnic discrimination and SEP dynamically interact to drive MDD risk. METHODS: We iteratively mapped the interactions and feedback loops between factors at the intersection of ethnic discrimination and SEP, drawing input from (i) a series of two interviews with a range of MDD domain experts, (ii) an existing CLD mapping the onset of MDD across psychological, biological, and social dimensions at the level of the individual, and (iii) other relevant literature. RESULTS: Through tracing the feedback loops in the resulting CLD, we identified ten driving mechanisms for MDD onset in ethnic minorities (two related to ethnic discrimination, SEP, social network and support, and acculturation, as well as one relating to the living environment and self-stigma towards MDD); and four factors that modulate these mechanisms (recent migration, religious affiliation, neighborhood social environment, and public stigma towards MDD). The intersecting nature of ethnic discrimination and SEP, combined with the reinforcing dynamics of the identified driving mechanisms across time- and spatial scales, underscores the excess exposure to circumstances that increase MDD risk in ethnic minorities. CONCLUSIONS: While this CLD requires validation through future studies, the intersecting and reinforcing nature of the identified driving mechanisms highlights that tackling the high risk of MDD in ethnic minorities may require intervening at multiple targets, from the individual (e.g., psychological interventions targeting negative beliefs or reducing stress) to the societal level (e.g., addressing labor market discrimination).

Objective Bayesian Edge Screening and Structure Selection for Ising Networks.

The Ising model is one of the most widely analyzed graphical models in network psychometrics. However, popular approaches to parameter estimation and structure selection for the Ising model cannot naturally express uncertainty about the estimated parameters or selected structures. To address this issue, this paper offers an objective Bayesian approach to parameter estimation and structure selection for the Ising model. Our methods build on a continuous spike-and-slab approach. We show that our methods consistently select the correct structure and provide a new objective method to set the spike-and-slab hyperparameters. To circumvent the exploration of the complete structure space, which is too large in practical situations, we propose a novel approach that first screens for promising edges and then only explore the space instantiated by these edges. We apply our proposed methods to estimate the network of depression and alcohol use disorder symptoms from symptom scores of over 26,000 subjects.

Modeling alcohol use disorder as a set of interconnected symptoms - Assessing differences between clinical and population samples and across external factors.

Alcohol use disorder is argued to be a highly complex disorder influenced by a multitude of factors on different levels. Common research approaches fail to capture this breadth of interconnecting symptoms. To address this gap in theoretical assumptions and methodological approaches, we used a network analysis to assess the interplay of alcohol use disorder symptoms. We applied the exploratory analysis to two US-datasets, a population sample with 23,591 individuals and a clinical sample with 483 individuals seeking treatment for alcohol use disorder. Using a Bayesian framework, we first investigated differences between the clinical and population sample looking at the symptom interactions and underlying structure space. In the population sample the time spent drinking alcohol was most strongly connected, whereas in the clinical sample loss of control showed most connections. Furthermore, the clinical sample demonstrated less connections, however, estimates were too unstable to conclude the sparsity of the network. Second, for the population sample we assessed whether the network was measurement invariant across external factors like age, gender, ethnicity and income. The network differed across all factors, especially for age subgroups, indicating that subgroup specific networks should be considered when deriving implications for theory building or intervention planning. Our findings corroborate known theories of alcohol use disorder stating loss of control as a central symptom in alcohol dependent individuals.

A Note on the Structural Change Test in Highly Parameterized Psychometric Models.

Equal parameter estimates across subgroups is a substantial requirement of statistical tests. Ignoring subgroup differences poses a threat to study replicability, model specification, and theory development. Structural change tests are a powerful statistical technique to assess parameter invariance. A core element of those tests is the empirical fluctuation process. In the case of parameter invariance, the fluctuation process asymptotically follows a Brownian bridge. This asymptotic assumption further provides the basis for inference. However, the empirical fluctuation process does not follow a Brownian bridge in small samples, and this situation is amplified in large psychometric models. Therefore, common methods of obtaining the sampling distribution are invalid and the structural change test becomes conservative. We discuss an alternative solution to obtaining the sampling distribution-permutation approaches. Permutation approaches estimate the sampling distribution through resampling of the dataset, avoiding distributional assumptions. Hereby, the tests power are improved. We conclude that the permutation alternative is superior to standard asymptotic approximations of the sampling distribution.

Effectiveness of ozone against endodontopathogenic microorganisms in a root canal biofilm model.

AIM: To assess the antimicrobial efficacy of aqueous (1.25-20 microg mL(-1)) and gaseous ozone (1-53 g m(-3)) as an alternative antiseptic against endodontic pathogens in suspension and a biofilm model. METHODOLOGY: Enterococcus faecalis, Candida albicans, Peptostreptococcus micros and Pseudomonas aeruginosa were grown in planctonic culture or in mono-species biofilms in root canals for 3 weeks. Cultures were exposed to ozone, sodium hypochlorite (NaOCl; 5.25%, 2.25%), chlorhexidine digluconate (CHX; 2%), hydrogen peroxide (H(2)O(2); 3%) and phosphate buffered saline (control) for 1 min and the remaining colony forming units counted. Ozone gas was applied to the biofilms in two experimental settings, resembling canal areas either difficult (setting 1) or easy (setting 2) to reach. Time-course experiments up to 10 min were included. To compare the tested samples, data were analysed by one-way anova. RESULTS: Concentrations of gaseous ozone down to 1 g m(-3) almost and aqueous ozone down to 5 microg mL(-1) completely eliminated the suspended microorganisms as did NaOCl and CHX. Hydrogen peroxide and lower aqueous ozone concentrations were less effective. Aqueous and gaseous ozone were dose- and strain-dependently effective against the biofilm microorganisms. Total elimination was achieved by high-concentrated ozone gas (setting 2) and by NaOCl after 1 min or a lower gas concentration (4 g m(-3)) after at least 2.5 min. High-concentrated aqueous ozone (20 microg mL(-1)) and CHX almost completely eliminated the biofilm cells, whilst H(2)O(2) was less effective. CONCLUSION: High-concentrated gaseous and aqueous ozone was dose-, strain- and time-dependently effective against the tested microorganisms in suspension and the biofilm test model.

Clinical performance of a new laser fluorescence device for detection of occlusal caries lesions in permanent molars.

OBJECTIVES: To determine the clinical performance of a laser fluorescence device (DIAGNOdent pen, KaVo) to discriminate between different occlusal caries depths (D(0)-D(1-4); D(0-2)-D(3,4)) in permanent molars. METHODS: In this prospective, randomized two-centre-study 120 sound/uncavitated carious sites in 120 patients were measured after visual and radiographic caries assessment. In cases of operative intervention (n=86), the lesion depths after caries removal were recorded (reference). In cases of preventive intervention (n=34), the sites were reassessed visually/radiographically after 12 months to verify the status assessed before (reference). The discrimination performance was determined statistically (Mann-Whitney test, Spearman's rho coefficient, and areas under the receiver operating characteristic curves (AUCs)). Sensitivities (SE) and specificities (SP) were plotted as a function of the measured values and cut-off values for the mentioned thresholds suggested. RESULTS: Sound sites (n=13) had significantly minor fluorescence values than carious sites (n=107) (P<0.0001) as had sites with no/enamel caries (n=63) compared to dentinal caries (n=57). The AUCs for the same discriminations were 0.92 and 0.78 (P<0.001). For the D(0)-D(1-4) threshold, a cut-off at a value of 12 (SE: 0.88, SP: 0.85) and for the D(0-2)-D(3,4) threshold at 25 (SE: 0.67, SP: 0.79) can be suggested. A moderate positive correlation between the measurements and the caries depths was calculated (rho=+0.57, P=0.01). CONCLUSION: Within this study, the device's discrimination performance for different caries depths was moderate to very good and it may be recommended as adjunct tool in the diagnosis of occlusal caries.

Effect of aqueous ozone on the NF-kappaB system.

Ozone has been proposed as an alternative oral antiseptic in dentistry, due to its antimicrobial power reported for gaseous and aqueous forms, the latter showing a high biocompatibility with mammalian cells. New therapeutic strategies for the treatment of periodontal disease and apical periodontitis should consider not only antibacterial effects, but also their influence on the host immune response. Therefore, our aim was to investigate the effect of aqueous ozone on the NF-kappaB system, a paradigm for inflammation-associated signaling/transcription. We showed that NF-kappaB activity in oral cells stimulated with TNF, and in periodontal ligament tissue from root surfaces of periodontally damaged teeth, was inhibited following incubation with ozonized medium. Under this treatment, IkappaBalpha proteolysis, cytokine expression, and kappaB-dependent transcription were prevented. Specific ozonized amino acids were shown to represent major inhibitory components of ozonized medium. In summary, our study establishes a condition under which aqueous ozone exerts inhibitory effects on the NF-kappaB system, suggesting that it has an anti-inflammatory capacity.

Efficacy of intraoral topical anesthetics in children.

OBJECTIVES: The literature reports mixed results regarding the efficacy of intraoral topical anesthetics. Only a few studies have been performed in children. Some non-placebo controlled studies have been carried out to compare the efficacy in reducing children's injection pain between different topical anesthetics METHODS: In a randomized, double blind, placebo controlled study with split-mouth design 104 children were enrolled to evaluate the efficacy of four topical anesthetics (Gingicain Spray, Gingicaine Topical Anesthetic, Legecain-Solution, EMLA Crème) when used prior to buccal injections within the conservative treatment of carious upper primary molars. The heart rate change and a Face Pain Scale were used as primary variables. The Visual Analog Scale, the modified Children's Hospital Pain Scale and the Sound-Eyes-Motor Scale were also evaluated. RESULTS: There was no significant difference between the placebo and any corresponding topical anesthetic with regard to the primary variables (HRC and FPS). A significant difference was found in favour of Gingicain Spray and Gingicaine Topical Anesthetic according to secondary variables (VAS, S(E)MS). CONCLUSION: While the secondary variables point to a benefit of the topical anesthetics Gingicain Spray and Gingicaine Topical Anesthetic compared to placebo, the results of the primary variables showed no differences in effectiveness of topical anesthetics and their corresponding placebos.

Effectiveness of 4 pulpotomy techniques--randomized controlled trial.

Pulpotomy is the accepted therapy for the management of cariously exposed pulps in symptom-free primary molars; however, evidence is lacking about the most appropriate technique. The aim of this study was to compare the relative effectiveness of the Er:YAG laser, calcium hydroxide, and ferric sulfate techniques with that of dilute formocresol in retaining such molars symptom-free. Two hundred primary molars in 107 healthy children were included and randomly allocated to one of the techniques. The treated teeth were blindly re-evaluated after 6, 12, 18, and 24 months. Descriptive data analysis and logistic regression analysis, accounting for each patient's effect by a generalized estimating equation (GEE), were used. After 24 months, the following total and clinical success rates were determined (%): formocresol 85 (96), laser 78 (93), calcium hydroxide 53 (87), and ferric sulfate 86 (100). Only calcium hydroxide performed significantly worse than formocresol (p = 0.001, odds ratio = 5.6, 95% confidence interval 2.0-15.5). In conclusion, calcium hydroxide is less appropriate for pulpotomies than is formocresol.

Inefficiency of cynarin as therapeutic regimen in familial type II hyperlipoproteinaemia.

Seventeen ambulant outpatients with familial Type IIa or Type IIb hyperlipoproteinaemia were treated with Cynarin, the 1,5-dicaffeyl ester of quinic acid, the constituent of the artichoke (Cynara scolymus). The dose tested was 250 mg and 750 mg daily. The mean serum cholesterol and triglyceride concentrations were not significantly changed within 3 months. Cynarin, administered per os, has no hypolipidaemic effect in familial Type II hyperlipoproteinaemia.

Etofibrate treatment alters low density lipoprotein susceptibility to lipid peroxidation.

The effect of the lipid lowering drug etofibrate was investigated on lipid peroxidation as well as on cholesterol level. Rabbits were given a 0.1% cholesterol containing diet. Total cholesterol, LDL-cholesterol, triglycerides and lipid peroxidation, expressed as thiobarbituric acid reactive products, were determined. Treatment with etofibrate led to a marked decrease in total cholesterol and LDL-cholesterol. Furthermore, Cu(2+)-induced lipid peroxide formation was reduced in etofibrate treated rabbits. These results could be confirmed in a human study when patients with moderate hypercholesterolaemia were treated with etofibrate (2 x 500 mg/day) for a period of eight weeks. It could be shown that the onset of lipid peroxidation was remarkably increased, an effect which was completely reversible. Thus, etofibrate is effective not only in lowering plasma cholesterol but also in rendering LDL less susceptible to oxidation.

Interdisciplinary rehabilitation and prevention in a case with early and extensive loss of primary teeth.

The oral rehabilitation of a five-and-a-half year old boy is presented, who had an almost complete dental loss due to caries at the age of three years. Partial and complete dentures were provided to restore function and aesthetics, to prevent psychological and speech disorders and to reduce the severity of malocclusion and loss of space in the permanent dentition. The long-term treatment planning objectives are discussed in relation to orthodontic considerations, the establishment of the permanent dentition and the expectations for future growth. This case demonstrates the requirement for interdisciplinary involvement in the treatment planning for children with extensive tooth loss.

In vivo performance of a laser fluorescence device for the approximal detection of caries in permanent molars.

OBJECTIVES: The aim of this randomised clinical trial was to investigate if a laser fluorescence device is able to discriminate between sound and carious approximal sites and between enamel and dentinal lesions, as well as to find appropriate cut-off values. METHODS: One hundred and seventeen sound or uncavitated carious sites in permanent molars were visually and radiographically examined, then either opened or not, after which their laser fluorescence was measured. Forty-three lesions were opened, the caries removed and the clinically identified caries depths were registered in addition to the radiographical scoring. Seventy-four sites were radiographically deemed sound or had enamel caries and were not opened. Here, the radiographical scorings were registered. RESULTS: Taking the radiographic scoring as gold standard for all investigated approximal sites, sound sites (D(0), n=40) showed significantly lower laser fluorescence measurements than carious sites (D(1-4), n=77) (Mann-Whitney test, P<0.025) suggesting a cut-off at 7 (sensitivity=0.68, specificity=0.7). Comparing measurements of D(0-2) (n=74) and D(3,4) (n=43), the results were also different by a statistically significant amount (P<0.025) and the cut-off calculated to be 16 (sensitivity=0.6, specificity=0.84). A fair positive correlation between laser fluorescence values and radiographical scoring was found (rho=+0.47, P<0.01). Analysing the 43 opened lesions with their clinically found lesion depths as gold standard, there was a fair positive correlation to the laser fluorescence values (rho=+0.34, P=0.03) and a moderately strong correlation to the radiographic scoring (rho=+0.67, P<0.01). CONCLUSION: The device may be an adjunct tool in the approximal detection of caries along with established procedures.