scholarly journals Multimodal neuroimaging and suicidality in a US population-based sample of school-aged children

2019 ◽  
Author(s):  
Pablo Vidal-Ribas ◽  
Delfina Janiri ◽  
Gaelle E. Doucet ◽  
Narun Pornpattananangkul ◽  
Dylan M. Nielson ◽  
...  
Keyword(s):  
Large Scale ◽  
Population Based ◽  
Reward Processing ◽  
Left Bank ◽  
Multimodal Neuroimaging ◽  
Available N ◽  
Predictive Values ◽  
School Aged Children ◽  
Wide Range ◽  
And Task

AbstractImportanceSuicide deaths and suicidality are considered a public health emergency, yet their brain underpinnings remain elusive.ObjectiveTo examine individual, environmental, and clinical characteristics, as well as multimodal brain imaging correlates of suicidality in a US population-based sample of school-aged children.DesignCross-sectional analysis of the first wave of data from the Adolescent Brain Cognitive Development studySettingMulticenter population-based studyParticipantsChildren aged 9-10 years from unreferred, community samples with suicidality data available (n=7,994). Following quality control, we examined structural magnetic resonance imaging (sMRI) (n=6,238), resting state functional MRI (rs-fMRI) (n=4,134), and task-based fMRI (range n=4,075 to 4,608).ExposureLifetime suicidality, defined as suicidal ideation, plans and attempts reported by children or/and caregivers.Main Outcomes and MeasuresMultimodal neuroimaging analyses examined differences with Welch’s t-test and Equivalence Tests, with observed effect sizes (ES, Cohen’s d) and their 90% confidence interval (CI) < |0.15|. Predictive values were examined using the area under precision-recall curves (AUPRC). Measures included, cortical volume and thickness, large-scale network connectivity and task-based MRI of reward processing, inhibitory control and working memory.ResultsAmong the 7,994 unrelated children (3,757 females [47.0%]), those will lifetime suicidality based on children (n=684 [8.6%]; 276 females [40.4%]), caregiver (n=654 [8.2%]; 233 females [35.6%]) or concordant reports (n=198 [2.5%]; 67 females [33.8%]), presented higher levels of social adversity and psychopathology on themselves and their caregivers compared to never-suicidal children (n=6,854 [85.7%]; 3,315 females [48.3%]). A wide range of brain areas was associated with suicidality, but only one test (0.06%) survived statistical correction: children with caregiver-reported suicidality had a thinner left bank of the superior temporal sulcus compared to never-suicidal children (ES=-0.17, 95%CI -0.26, -0.08, pFDR=0.019). Based on the prespecified bounds of |0.15|, ∼48% of the group mean differences for child-reported suicidality comparisons and a ∼22% for parent-reported suicidality comparisons were considered equivalent. All observed ES were relatively small (d≤|0.20|) and with low predictive value (AUPRC≤0.10).Conclusion and RelevanceUsing commonly-applied neuroimaging measures, we were unable to find a discrete brain signature related to suicidality in youth. There is a great need for improved approaches to the neurobiology of suicide.

scholarly journals Use of Antiplatelet Agents Decreases the Positive Predictive Value of Fecal Immunochemical Tests for Colorectal Cancer but Does Not Affect Their Sensitivity

2021 ◽  
Vol 11 (6) ◽  
pp. 497
Author(s):  
Yoonsuk Jung ◽  
Eui Im ◽  
Jinhee Lee ◽  
Hyeah Lee ◽  
Changmo Moon
Keyword(s):  
Colorectal Cancer ◽  
Large Scale ◽  
Screening Program ◽  
Antiplatelet Agents ◽  
Population Based ◽  
Small Sample ◽  
Antithrombotic Agents ◽  
Predictive Values ◽  
Prescription Rates ◽  
Small Sample Sizes

Previous studies have evaluated the effects of antithrombotic agents on the performance of fecal immunochemical tests (FITs) for the detection of colorectal cancer (CRC), but the results were inconsistent and based on small sample sizes. We studied this topic using a large-scale population-based database. Using the Korean National Cancer Screening Program Database, we compared the performance of FITs for CRC detection between users and non-users of antiplatelet agents and warfarin. Non-users were matched according to age and sex. Among 5,426,469 eligible participants, 768,733 used antiplatelet agents (mono/dual/triple therapy, n = 701,683/63,211/3839), and 19,569 used warfarin, while 4,638,167 were non-users. Among antiplatelet agents, aspirin, clopidogrel, and cilostazol ranked first, second, and third, respectively, in terms of prescription rates. Users of antiplatelet agents (3.62% vs. 4.45%; relative risk (RR): 0.83; 95% confidence interval (CI): 0.78–0.88), aspirin (3.66% vs. 4.13%; RR: 0.90; 95% CI: 0.83–0.97), and clopidogrel (3.48% vs. 4.88%; RR: 0.72; 95% CI: 0.61–0.86) had lower positive predictive values (PPVs) for CRC detection than non-users. However, there were no significant differences in PPV between cilostazol vs. non-users and warfarin users vs. non-users. For PPV, the RR (users vs. non-users) for antiplatelet monotherapy was 0.86, while the RRs for dual and triple antiplatelet therapies (excluding cilostazol) were 0.67 and 0.22, respectively. For all antithrombotic agents, the sensitivity for CRC detection was not different between users and non-users. Use of antiplatelet agents, except cilostazol, may increase the false positives without improving the sensitivity of FITs for CRC detection.

scholarly journals HyP-ABC: A Novel Automated Hyper-Parameter Tuning Algorithm Using Evolutionary Optimization

2021 ◽  
Author(s):  
Leila Zahedi ◽  
Farid Ghareh Mohammadi ◽  
M. Hadi Amini
Keyword(s):  
Real World ◽  
Large Scale ◽  
Convergence Rates ◽  
Parameter Tuning ◽  
Population Based ◽  
Machine Learning Techniques ◽  
Gradient Boosting ◽  
Support Vector ◽  
Wide Range ◽  
Extreme Gradient Boosting

<p>Machine learning techniques lend themselves as promising decision-making and analytic tools in a wide range of applications. Different ML algorithms have various hyper-parameters. In order to tailor an ML model towards a specific application working at its best, its hyper-parameters should be tuned. Tuning the hyper-parameters directly affects the performance. However, for large-scale search spaces, efficiently exploring the ample number of combinations of hyper-parameters is computationally expensive. Many of the automated hyper-parameter tuning techniques suffer from low convergence rates and high experimental time complexities. In this paper, we propose HyP-ABC, an automatic innovative hybrid hyper-parameter optimization algorithm using the modified artificial bee colony approach, to measure the classification accuracy of three ML algorithms: random forest, extreme gradient boosting, and support vector machine. In order to ensure the robustness of the proposed method, the algorithm takes a wide range of feasible hyper-parameter values and is tested using a real-world educational dataset. Experimental results show that HyP-ABC is competitive with state-of-the-art techniques. Also, it has fewer hyper-parameters to be tuned than other population-based algorithms, making it worthwhile for real-world HPO problems.</p>

scholarly journals Validation of Coding Algorithms for the Identification of Patients with Primary Biliary Cirrhosis Using Administrative Data

2010 ◽  
Vol 24 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Robert P Myers ◽  
Abdel Aziz M Shaheen ◽  
Andrew Fong ◽  
Alex F Wan ◽  
Mark G Swain ◽  
...  
Keyword(s):  
Primary Biliary Cirrhosis ◽  
Administrative Data ◽  
Large Scale ◽  
Optimal Algorithm ◽  
Epidemiological Studies ◽  
Population Based ◽  
Sensitivity Analyses ◽  
Administrative Databases ◽  
Biliary Cirrhosis ◽  
Predictive Values

BACKGROUND: Large-scale epidemiological studies of primary biliary cirrhosis (PBC) have been hindered by difficulties in case ascertainment.OBJECTIVE: To develop coding algorithms for identifying PBC patients using administrative data – a widely available data source.METHODS: Population-based administrative databases were used to identify patients with a diagnosis code for PBC from 1994 to 2002. Coding algorithms for confirmed PBC (two or more of antimitochondrial antibody positivity, cholestatic liver biochemistry and/or compatible liver histology) were derived using chart abstraction data as the reference. Patients with a recorded PBC diagnosis but insufficient confirmatory data were classified as ‘suspected PBC’.RESULTS: Of 189 potential PBC cases, 119 (60%) had confirmed PBC and 28 (14%) had suspected PBC. The optimal algorithm including two or more uses of a PBC code had a sensitivity of 94% (95% CI 71% to 100%) and positive predictive values of 73% (95% CI 61% to 75%) for confirmed PBC, and 89% (95% CI 82% to 94%) for confirmed or suspected PBC. Sensitivity analyses revealed greater accuracy among women, and with the use of multiple data sources and one or more years of data. Inclusion of diagnosis codes for conditions frequently misclassified as PBC did not improve algorithm performance.CONCLUSIONS: Administrative databases can reliably identify patients with PBC and may facilitate epidemiological investigations of this condition.

scholarly journals GPU-Based Parallel Particle Swarm Optimization Methods for Graph Drawing

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jianhua Qu ◽  
Xiyu Liu ◽  
Minghe Sun ◽  
Feng Qi
Keyword(s):  
Particle Swarm Optimization ◽  
Large Scale ◽  
Graph Drawing ◽  
Optimization Problems ◽  
Particle Swarm ◽  
Optimization Methods ◽  
Population Based ◽  
Pictorial Representation ◽  
Swarm Optimization ◽  
Wide Range

Particle Swarm Optimization (PSO) is a population-based stochastic search technique for solving optimization problems, which has been proven to be effective in a wide range of applications. However, the computational efficiency on large-scale problems is still unsatisfactory. A graph drawing is a pictorial representation of the vertices and edges of a graph. Two PSO heuristic procedures, one serial and the other parallel, are developed for undirected graph drawing. Each particle corresponds to a different layout of the graph. The particle fitness is defined based on the concept of the energy in the force-directed method. The serial PSO procedure is executed on a CPU and the parallel PSO procedure is executed on a GPU. Two PSO procedures have different data structures and strategies. The performance of the proposed methods is evaluated through several different graphs. The experimental results show that the two PSO procedures are both as effective as the force-directed method, and the parallel procedure is more advantageous than the serial procedure for larger graphs.

scholarly journals Digital and traditional communication with kin: Displacement or reinforcement?

2021 ◽  
Author(s):  
Mirkka Danielsbacka ◽  
Kristiina Tammisalo ◽  
Antti O Tanskanen
Keyword(s):  
Older Adults ◽  
Large Scale ◽  
Digital Communication ◽  
Population Based ◽  
Confounding Factors ◽  
Middle Aged ◽  
Face To Face ◽  
Digital Era ◽  
Wide Range ◽  
Parent Child

A salient question in the digital era is whether new forms of digital communication (e.g., instant messages, video calls, e-mails) have displaced or reinforced more traditional forms of communication (e.g., meeting face-to-face, contact by phone, sending letters/postcards). These opposing hypotheses, i.e., digital communication as a reinforcer versus a displacer, have attracted abundant attention among scholars; however, studies have scarcely explored these hypotheses in the context of communication among kin. Using large-scale and population-based data of 1,945 young to middle-aged (18–55 year-olds) and 2,663 older (68–73 year-olds) Finns, we tested the predictions derived from the displacement and reinforcement hypotheses in several kin dyads (parent-child, grandparent-grandchild, siblings, and aunt/uncle-niece/nephew). The results strongly supported the reinforcement hypothesis in all kin dyads, and in both younger and older adults. Associations were positive even after controlling for a wide range of potentially confounding factors. Hence, it can be concluded that digital means may reinforce rather than displace traditional forms of contact.

scholarly journals Multimodal Neuroimaging and Suicidality in a U.S. Population-Based Sample of School-Aged Children

2020 ◽  
Vol 87 (9) ◽  
pp. S310
Author(s):  
Pablo Vidal-Ribas Belil ◽  
Delfina Janiri ◽  
Gaelle E. Doucet ◽  
Narun Pornpattananangkul ◽  
Dylan M. Nielson ◽  
...  
Keyword(s):  
Population Based ◽  
Multimodal Neuroimaging ◽  
School Aged Children

scholarly journals Association between schizophrenia and an autoimmune bullous skin disease-pemphigus: a population-based large-scale study

2017 ◽  
Vol 28 (2) ◽  
pp. 191-198 ◽  
Author(s):  
K. Kridin ◽  
S. Zelber-Sagi ◽  
D. Comaneshter ◽  
A. D. Cohen
Keyword(s):  
Multivariate Analysis ◽  
Large Scale ◽  
Matched Control ◽  
Univariate Analysis ◽  
Real Life ◽  
Population Based ◽  
Cross Sectional Study ◽  
Control Group ◽  
Cross Sectional ◽  
Wide Range

Aims.Immunological hypotheses have become increasingly prominent suggesting that autoimmunity may be involved in the pathogenesis of schizophrenia. Schizophrenia was found to be associated with a wide range of autoimmune diseases. However, the association between pemphigus and schizophrenia has not been established yet. We aimed to estimate the association between pemphigus and schizophrenia using a large-scale real-life computerised database.Methods.This study was conducted as a cross-sectional study utilising the database of Clalit Health Services. The proportion of schizophrenia was compared between patients diagnosed with pemphigus and age-, gender- and ethnicity-matched control subjects. Univariate analysis was performed usingχ2and Student'st-test and a multivariate analysis was performed using a logistic regression model.Results.A total of 1985 pemphigus patients and 9874 controls were included in the study. The prevalence of schizophrenia was greater in patients with pemphigus as compared to the control group (2.0%v. 1.3%, respectively;p= 0.019). In a multivariate analysis, pemphigus was significantly associated with schizophrenia (OR, 1.5; 95% CI, 1.1–2.2). The association was more prominent among females, patients older than 60 years, and Jews.Conclusions.Pemphigus is significantly associated with schizophrenia. Physicians treating patients with pemphigus should be aware of this possible association. Patients with pemphigus should be carefully assessed for comorbid schizophrenia and be treated appropriately.

scholarly journals Analysis of causes of failures in 10 kV electrical power distribution networks (on the example of the Southern electrical networks of the city of Irkutsk)

2019 ◽  
Vol 11 (4) ◽  
pp. 299-304
Author(s):  
I. V. Naumov ◽  
E. V. Karpova
Keyword(s):  
Power Supply ◽  
Power Distribution ◽  
Large Scale ◽  
Electrical Power ◽  
Electric Energy ◽  
Distribution Networks ◽  
Economic Damage ◽  
Left Bank ◽  
Electrical Networks ◽  
Wide Range

Disconnection of power consumers from power grids is quite a common event, with a wide range of consequences. Power supply interruptions can be caused by both casual events, and planned shutdowns. Disruptions in systems of power supply of consumers lead to a variety of adverse events (under-delivery of products, large-scale product rejection, failure of production equipment, etc.), which inflicts a significant economic damage. The retrospective analysis of the failure rate of electrical networks of the Right Bank and Left Bank districts of Irkutsk over 2013–2017 has been carried out. The analysis was based on the data from dispatching logs of observations on events of failures caused by emergency damage to the Southern electrical networks. It is established that the greatest number of failures occurs for such reasons as damage at substations, damage to consumer electrical networks, wire breakage in air and cable power lines as well as damage of switching equipment. Failures related to wind load, damage at packaged transformer substations, insulators and surge arresters are also analysed. The percentage rate of failures of electrical power networks caused by specific reasons from the total number of failures is presented. Besides, the analysis is performed of the duration of interruptions of power supply owing to damage of individual elements of power network equipment as well as the amount of electric energy undelivered for these reasons, and financial losses caused by these failures due to under-delivery of electric energy, with the average wholesale electricity prices taken into account.

scholarly journals Higher BMI, but not obesity-related genetic polymorphisms, correlates with lower structural connectivity of the reward network in a population-based study

2020 ◽  
Author(s):  
Frauke Beyer ◽  
Rui Zhang ◽  
Markus Scholz ◽  
Kerstin Wirkner ◽  
Markus Loeffler ◽  
...  
Keyword(s):  
Genetic Polymorphisms ◽  
Genetic Variants ◽  
Structural Connectivity ◽  
Population Based ◽  
Reward Processing ◽  
Clustering Coefficient ◽  
Graph Metrics ◽  
Wide Range ◽  
Reward Network ◽  
Connectivity Strength

Abstract Background Obesity is of complex origin, involving genetic and neurobehavioral factors. Genetic polymorphisms may increase the risk for developing obesity by modulating dopamine-dependent behaviors, such as reward processing. Yet, few studies have investigated the association of obesity, related genetic variants, and structural connectivity of the dopaminergic reward network. Methods We analyzed 347 participants (age range: 20–59 years, BMI range: 17–38 kg/m2) of the LIFE-Adult Study. Genotyping for the single nucleotid polymorphisms rs1558902 (FTO) and rs1800497 (near dopamine D2 receptor) was performed on a microarray. Structural connectivity of the reward network was derived from diffusion-weighted magnetic resonance imaging at 3 T using deterministic tractography of Freesurfer-derived regions of interest. Using graph metrics, we extracted summary measures of clustering coefficient and connectivity strength between frontal and striatal brain regions. We used linear models to test the association of BMI, risk alleles of both variants, and reward network connectivity. Results Higher BMI was significantly associated with lower connectivity strength for number of streamlines (β = −0.0025, 95%—C.I.: [−0.004, −0.0008], p = 0.0042), and, to lesser degree, fractional anisotropy (β = −0.0009, 95%—C.I. [−0.0016, −0.00008], p = 0.031), but not clustering coefficient. Strongest associations were found for left putamen, right accumbens, and right lateral orbitofrontal cortex. As expected, the polymorphism rs1558902 in FTO was associated with higher BMI (F = 6.9, p < 0.001). None of the genetic variants was associated with reward network structural connectivity. Conclusions Here, we provide evidence that higher BMI correlates with lower reward network structural connectivity. This result is in line with previous findings of obesity-related decline in white matter microstructure. We did not observe an association of variants in FTO or near DRD2 receptor with reward network structural connectivity in this population-based cohort with a wide range of BMI and age. Future research should further investigate the link between genetics, obesity and fronto-striatal structural connectivity.

Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1362-1363
Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Hexagonal Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Tin Films ◽  
Wide Range ◽  
Fcc Phase ◽  
Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

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