Linear Effects Models Research Articles

Fracture Analysis of Concrete Structures: Prediction Based on Boundary Effect Model

A simple design model, able to link test results of small concrete samples to failures of large structures, is desirable for fracture analysis of concrete structures, particularly if the model has no special requirements on small samples, e.g., size, notched or un-notched. The linear Boundary Effect Model (BEM, which has evolved over the past 20 years, is able to provide the link between small samples and large structures with fairly reliable predictions and a built-in function of statistical analysis. BEM enables researchers and engineers to model the quasi-brittle fracture behavior of concrete and the associated size effects by focusing on the fracture process zone (FPZ) at the notch tip or at the specimen boundary (for an un-notched case). FPZ and quasi-brittle fracture of concrete are directly influenced by the average aggregate size (dav), but few models mathematically show such critical aggregate influence, except BEM. The aggregate size used in BEM can be accurately estimated separately before fracture experiments. A comprehensive dataset of concrete fracture results from the existing literature, along with a new experimental dataset from three-point bending (3-P-B) tests, involving 138 specimens with varying notch depths (un-notched, 1 mm shallow-notched, and 6 mm deep-notched) was analyzed. The specimens, which present inconsistent dimensions (160 mm span, approximately 40 mm thickness, and 38 mm width/height), were used to estimate FPZ at peak fracture loads and investigate their interactions with structural boundaries. Statistical analyses were integrated into BEM, allowing the model to account for the experimental scatter, thus improving its reliability as a predictive tool for maximum fracture loads of concrete structures. This study confirmed again that the linear BEM is easy to use and provides fairly accurate predictions across concrete specimens and structures of various sizes.

Identifying Total Causal Effects in Linear Models under Partial Homoscedasticity

Identifying Total Causal Effects in Linear Models under Partial Homoscedasticity

Change in D3Cr muscle mass in oldest old men and its association with changes in grip strength and walking speed.

The use of lean soft tissue (LST) mass as a surrogate measurement of skeletal muscle mass (SMM) has led to the conclusion that muscle loss is poorly related to functional decline. We hypothesized that when using a more accurate measure of SMM determined by D3-creatine dilution (D3Cr), longitudinal changes in SMM will be similar in magnitude to changes in strength and physical performance and that skeletal muscle mass will partially mediate the relationship of age with these outcomes. We measured change in D3Cr muscle mass (kg), handgrip strength (kg), and 6m walk speed (m/s) in 208 men from the Osteoporotic Fractures in Men Study (85.2 ± 4.3 years) over an average of 6.1 years follow-up. Mixed linear effects models adjusted for potential confounders were used to examine the relationship of changes in D3Cr muscle mass with changes in grip strength and walking speed. Annual losses of D3Cr muscle mass, grip strength, and walking speed were 2.1%, 2.2%, and 2.6%, respectively (p < 0.001). Each additional kg loss in D3Cr muscle mass was associated with a 0.55 kg loss in grip strength and a 0.01 m/s loss in walking speed independent of changes in age (p < 0.001). 41.3% and 22.4% of the relationship between age and loss of grip strength and walking speed, respectively, was attributed to loss of D3Cr muscle mass (p < 0.001). Skeletal muscle mass may have a more important role than previously considered and should not be overlooked as a potentially modifiable determinant in the loss of strength and performance in older age.

Acute Cervical Vagus Nerve Stimulation Modulates Gastric Slow Waves in the Distal Rat Stomach.

Gastric motility is coordinated by bioelectrical events, named slow waves, which propagate across the stomach. Gastric dysrhythmias are associated with disorders of gut-brain interaction. Electrical cervical vagus nerve stimulation (cVNS) affects gastric contractions, but associated changes in gastric slow waves have not been quantified. Three cVNS protocols (low: 0.30 ms, 0.25 mA, 1 Hz; medium: 0.50 ms, 0.50 mA, 5 Hz; high: 1.00 ms, 1.00 mA, 10 Hz) were administered to six rats. Gastric slow waves were concurrently recorded from the serosa of the antrum and distal corpus using flexible electrode arrays. Slow wave amplitude and frequency (mean ± standard deviation) were analyzed with a mixed linear effects model. cVNS had no effect on mean slow wave amplitude (p ≥ 0.2208). Slow wave frequency decreased during the high stimulation protocol compared to sham (3.93 ± 0.90 cpm to 3.49 ± 0.54 cpm, p = 0.0374, antrum; 3.94 ± 1.04 cpm to 3.15 ± 0.53 cpm, p < 0.0001, distal corpus) but returned to sham levels after a recovery period (p = 0.9190, antrum; p = 0.9995, distal corpus). Ectopic activation of gastric slow waves occurred during cVNS, resulting in a transient effect on gastric slow wave frequency and propagation but not amplitude. Slow wave activity was modified by acute medium and high cVNS stimulation protocols with changes in propagation patterns and mean frequency. Therefore, modified slow wave activity could affect gastric motility function during acute cVNS.

Photon-counting CT yields superior abdominopelvic image quality at lower radiation and iodinated contrast doses.

Photon-counting detector (PCD) computed tomography (CT) has been shown to provide better image quality at lower radiation and intravenous contrast doses than energy-integrating detector (EID) CT in adult patients. There is limited data on these benefits for the pediatric population especially for abdominopelvic CT examinations. This study examines a reduced weight-based iodinated contrast dosing strategy in pediatric abdominopelvic CT on a PCD-CT system compared to standard dosing protocols on EID-CT using 1 mL/kg and 2 mL/kg, respectively. Image quality is assessed using both quantitative and qualitative measures. We also compare the radiation dose profile between the two PCD-CT and EID-CT cohorts. This HIPAA-compliant, IRB-approved, retrospective study included pediatric patients (≤18 years of age) who underwent contrast-enhanced CT examinations of the abdomen and pelvis for routine clinical care (01/2022 - 01/2023) in the portal-venous phase on a PCD-CT (NAEOTOM Alpha; Siemens Healthineers). Inclusion criteria included a similar prior examination within 12-months on a dual-source EID-CT scanner from the same vendor. All PCD-CT and EID-CT scans were acquired using weight-based dosing for intravenous contrast media, 1 mL/kg and 2 mL/kg, respectively, based on institutional protocols. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured in the aorta, portal vein, liver parenchyma, and skeletal muscle. Three pediatric radiologists qualitatively evaluated each scan for overall image quality, noise, and contrast on a scale of 0-100. Confidence in small structure detection (common bile duct) was also rated on a scale of 0-3. Radiation doses (size-specific dose estimate (SSDE)) were calculated. Statistical analysis included paired t-tests and a mixed linear effects model to account for patient age, sex, and X-ray tube voltage. A P<0.05 indicated statistical significance. A total of 49 patients were included (24 female; mean [SD] age 9.9 [6.3] years, range 0.6-18 years). Compared to EID-CT, PCD-CT had a higher mean SNR in the portal vein (23.4 [SD=9.3] vs 17.2 [SD=7.4], P<0.001), aorta (23.4 [SD=11.6] vs 17.7 [10.1], P=0.017), hepatic parenchyma (15.2 [SD=5.6] vs 13.2 [5.1], P=0.016), and skeletal muscle (5.7 [SD=3.1] vs 4.5 [SD=3.1], P=0.01). Compared to EID-CT, PCD-CT also had a higher mean CNR in the portal vein (27.5 [SD=9.6] vs 22.1 [SD=21.1], P=0.003), aorta (27.3 [SD=9.6] vs 22.3 [SD=11.8], P=0.004), hepatic parenchyma (20 [SD=6.9] vs 16.9 [SD=8.5], P=0.013), and skeletal muscle (14.6 [4.9] vs 12.1 [5.6], P=0.008). Overall image quality, image noise, and small structure detection confidence scores were higher on PCD-CT than EID-CT (P=0.037, P<0.001, and P=0.006, respectively). Mean SSDE for PCD-CT was lower than EID-CT (9.1 mGy [SD=4.3] vs 11 mGy [5.9], P=0.012). Compared with EID-CT, contrast-enhanced pediatric abdominopelvic CT offers improved subjective and objective image quality, even at lower radiation doses and reduced intravenous contrast medium volumes.

Investigating Cognitive Load and Autonomic Arousal During Voice Production and Vocal Auditory-Motor Adaptation.

Cognitive load and autonomic arousal are hypothesized to affect voice production, yet the nature of these relationships is unclear. The purpose of this study was to assess how cognitive load and autonomic arousal differentially affect voice production and vocal motor control. Physiological measures of autonomic arousal were recorded from 30 adults under different cognitive loads elicited by a Stroop task. In Experiment 1, voice acoustic measures were measured during speech production. In Experiment 2, fundamental frequency (fo) responses to predictably altered auditory feedback (sensorimotor adaptation) were measured. Mixed linear-effects models assessed relationships between variables. Changes between cognitive loads were compared among the two experiments. In Experiment 1, increased cognitive load was associated with increases in sound pressure level, whereas increases in autonomic arousal measures (i.e., decreases in skin conductance rise time, pulse amplitude, and period) were related to decreases in cepstral peak prominence. Increased autonomic arousal (i.e., decreased pulse amplitude) was related to increased adaptation in Experiment 2. Participants who responded to increased cognitive load by decreasing fo during Experiment 1 showed more adaptation in Experiment 2. Differential effects of cognitive load and autonomic arousal emphasize the importance of individual physiological variability when assessing how stress affects the voice.

Regulation of cerebrovascular resistance below the lower limit of cerebral autoregulation during induced hypotension: an observational study.

Regulation of cerebrovascular resistance below the lower limit of cerebral autoregulation during induced hypotension: an observational study.

Potential of photon-counting detector CT technology for contrast medium reduction in portal venous phase thoracoabdominal CT.

To compare image quality and iodine attenuation intra-individually in portal venous phase photon-counting detector CT (PCD-CT) scans using protocols with different contrast medium (CM) volume. A prospectively acquired patient cohort between 04/2021 and 11/2023 was retrospectively screened if patients had the following combination of portal venous phase thoracoabdominal CT scans: (a) PCD-CT with 120 mL CM volume (PCD-CT120 mL), (b) PCD-CT with 100 mL CM volume (PCD-CT100 mL), and (c) prior energy-integrating detector CT (EID-CT) with 120 mL CM volume. On PCD-CT, virtual monoenergetic image (VMI) reconstructions at 70 keV were applied for both groups as well as additional VMI at 60 keV for PCD‑CT100 mL. Quantitative analyses including signal-to-noise (SNR) and contrast-to-noise ratios (CNR) and qualitative analyses were performed using a mixed linear effects model. The final study cohort comprised 49 patients (mean age 67 [31-86] years, 12 female). Comparison to EID-CT was available in 33 patients. In standard 70 keV VMI reconstructions, PCD-CT100 mL was non-inferior to PCD-CT120 mL as well as to EID-CT120 mL for CNR in abdominal organs (all p > 0.050). The mixed linear effects model revealed significant differences between contrast volume groups for both contrast enhancement and image quality ratings. PCD-CT100 mL/70 keV demonstrated the smallest deviation from optimal contrast enhancement (-0.306, p < 0.001). In portal venous phase thoracoabdominal PCD-CT, a nearly 17% reduction in CM was achievable while maintaining subjective and objective image quality compared to prior higher CM volume PCD-CT scans within the same patients and still surpassing image quality of previous exams on an EID-CT system. Question How do image quality and iodine attenuation intra-individually compare in portal venous phase photon-counting detector CT (PCD-CT) scans using protocols with different contrast medium volume. Findings PCD-CT scans exhibit superior quantitative and qualitative image quality compared to energy-integrating detector-CT acquisitions and are not negatively affected by contrast volume reductions up to 17%. Clinical relevance This study provides further evidence that PCD-CT enables a considerable reduction in iodine dose for portal venous phase acquisition, benefiting both patients and healthcare system costs.

Sociobehavioral determinants of non-retention among adolescents and young adults living with HIV.

This study aimed to identify age-specific cofactors of nonretention among adolescents and young adults living with HIV (AYLHIV) ages 10-24. This analysis used data from the Data-Informed Stepped Care study (DiSC; NCT05007717), a cluster randomized clinical trial in 24 health facilities in Western Kenya. During 12-month follow-up, youth-reported cofactors of missed visits and loss-to-follow-up (LTFU; did not return to clinic within study period) were assessed using generalized linear and mixed effect models and stratified by gender and age. Among 1904 AYLHIV, median age was 17 years (interquartile range 14-19), and 57.9% were female. A higher proportion of missed visits was observed in older ages (10-14: 6.0%; 15-19: 7.9%; 20-24: 12.5%). Overall, higher resilience (PR = 0.93) and satisfaction with clinic (PR = 0.81) were associated with lower risk of missed visits. Among males, satisfaction with clinic was associated with lower risk (PR = 0.61) while higher stigma was associated with increased risk (PR = 1.31). Among females, resilience was associated with lower risk (PR = 0.93). Having no living parents was associated with higher LTFU risk (PR = 2.24). Among males, horizontal transmission was associated with higher risk (PR = 2.98) and resilience with lower risk (PR = 0.76). Females who came to clinic alone had lower risk of LTFU (PR = 0.27). Age-stratified analyses did not identify additional cofactors. In this large multisite cohort, older AYLHIV had the most retention challenges. Resilience, satisfaction with clinical care, and stigma exerted an influential role, but cofactors differed between age and gender strata, underscoring the heterogeneity of AYLHIV and suggesting need for tailored approaches.

An Established Plant Invader May Still Benefit From Increasing Genetic Diversity-Insights From Artificial Populations in a Common Garden Experiment.

Genetic diversity and competitive ability, though extensively studied in the context of biological invasions, are still poorly understood in their relative importance, especially when shifting the perspective from an individual plant's phenotype to overall population performance. Most approaches addressing the role of genetic diversity involve the comparison of standing genetic variation in field populations combined with experimental treatments on individual plants. Composing predefined mixtures of populations to manipulate genetic diversity would be an experimental approach to test for direct effects on population performance. We determined pairwise genetic distances among 16 invasive and 22 native populations of Jacobaea vulgaris GAERTN. using single nucleotide polymorphisms (SNP). Based on this information, we created each 15 de-novo populations with different levels of genetic diversity for both origins. These de-novo populations were subjected to three levels of decreasing microsite availability by using a matrix of either 0, 5, or 10 individuals of Festuca rubra. We monitored population performance continuously throughout two growing seasons to study effects of interactions between origin, microsite availability, and genetic diversity with (generalized) linear effects models. This allowed us to uncover whether the relative importance of those factors varies with the life-stage of this biennial species. We found no ambiguous patterns on the hypothesized beneficial effect of genetic diversity for J. vulgaris populations. Native populations tended to respond negatively to increasing genetic diversity, especially under more favorable site conditions, but this was not a persistent pattern and was only evident through continuous monitoring. Invasive populations could benefit from increasing genetic diversity during early establishment, but not in interaction with restricted microsite availability. Our results do suggest that genetic variation supports population establishment and performance under certain environmental conditions. Therefore, for recommendations in nature conservation, efforts should still aim at limiting propagule addition in already invaded areas, even in well-established invasive species.

Updated Adjustment of the HCAHPS Survey for New Modes of Survey Administration and Patient Mix.

Web-first multimode survey protocols increase HCAHPS survey response rates and representativeness but may result in different HCAHPS scores because of survey mode effects and selective email address availability. A variable absent from many patient-mix adjustment models that may result in more positive patient experiences is whether the hospital admission was planned; adjustment for planned stays may better measure hospital performance. Develop adjustments for new Web-first survey protocols and planned admissions to facilitate comparisons across hospitals. Using 2021 survey mode experiment data, we estimate survey protocol effects in linear models predicting HCAHPS top-box outcomes from protocol indicators (which incorporate email availability for Web-first protocols), patient-mix adjustors, and hospital intercepts. We evaluate the unique effect on scores of whether a stay was planned. Phone-only and Web-Phone without email produce more positive responses than Mail-only, requiring negative adjustments. All other survey protocol effects and adjustments are mixed in direction and generally small. Planned stays are associated with more positive experiences for otherwise similar patients and make a unique contribution beyond other current patient-mix adjustment variables. It is important to adjust HCAHPS scores for survey protocol effects to ensure fair comparisons across hospitals and to enable hospitals to choose the survey protocol that best represents their patients. Incomplete email address availability necessitates that HCAHPS survey protocol adjustment control for email address availability when a Web-first protocol is used. Accounting for differences associated with planned stays may improve patient-mix adjustment.

Normal variations of myocardial T1, T2 and T2* values at 1.5 T cardiac MRI in sex-matched healthy volunteers.

Normal variations of myocardial T1, T2 and T2* values at 1.5 T cardiac MRI in sex-matched healthy volunteers.

Association of small vessel disease progression with longitudinal cognitive decline across mild cognitive impairment.

Cerebral small vessel disease (SVD) is the leading cause of vascular dementia. However, it is unclear whether the individual SVD or global SVD progression correlates with cognitive decline across mild cognitive impairment (MCI) subjects. To investigate the association of small vessel disease progression with longitudinal cognitive decline across MCI. We included 432 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, with 151 participants in the cognitively normal (CN) group and 281 participants in the MCI group. We evaluated magnetic resonance imaging-based SVD markers in both CN and MCI groups and explored their associations with 12-and 24-month cognitive decline using linear mixing effect (LME) models. In the CN group, cerebral microbleed (CMB) progression was associated with the decline in language function (p < 0.05), and deep white matter hyperintensity (WMH) progression was associated with a decline in memory function (p < 0.05). In the MCI group, CMB progression was associated with a decline in memory function (p < 0.05) and lacunes progression was associated with executive function (p < 0.05), whereas the progression of global SVD score was not related to longitudinal cognitive function. The progression of CMB and WMH had an impact on cognitive decline in both CN and MCI groups, and lacunes progression only had an association with cognitive decline in the MCI group. Our study suggested that individual SVD markers may have a higher predictive value in longitudinal cognition compared with global SVD burden.

Neuroanatomical prediction of individual anxiety problems level using machine learning models: A population-based cohort study of young adults.

Neuroanatomical prediction of individual anxiety problems level using machine learning models: A population-based cohort study of young adults.

Establishment of an Integrated Population Pharmacokinetic/ Pharmacodynamics Model of Apixaban in Chinese Healthy Population Adjusting for Key Genetic Variants.

To improve the understanding of pharmacokinetic/pharmacodynamic (PK/PD) profiles of apixaban, supporting personalised drug prescriptions for future patients. Genetic as well as nongenetic factors can affect the predictable PK and PD characteristics of apixaban. Establish a integrated popPK/PD model that adjusts for critical genetic variant. The integrated PK/PD models was characterized on the basis of PK (apixaban blood concentration) and PD (prothrombin time (PT), activated partial thromboplastin time (APTT), and anti-FXa activity) data from 181 healthy Chinese volunteers. Other investigated covariate variables included: Meaningful intrinsic and extraneous determinants, correlated genetic factors (ABCG2, F13A1, C3, etc.). A total of 2877 PK concentration observations were included in the modeling dataset. The PK model of apixaban is adopted by single compartment model with first-order oral absorption. The estimated values of total clearance rate (CL/F), apparent distribution volume (V/F), and absorption rate constant (KA) in the final model are 3.37 L/h, 28.2 L, and 0.781 1/h, respectively. The PK model includes significance covariates such as FOOD, RBC, WT, and gene (ABCG2). The PD model of apixaban is adopted by a linear direct effect model with additive error, which was used to describe the relationship between markers such as APTT, PT, anti-FXa, versus plasma concentration. PK simulation within the modelled dose range is similar to clinical real date, while PD simulation results also show that the simulated exposure parameters is within the range of the literature. We established a comprehensive PK/PD model and used it to simulate markers level such as APTT, PT, and anti-FXa of apixaban. Individual predictive values with a dose of 2.5 mg are basically within the expected recommended range.

Effects of Integrating Stair Climbing-Based Exercise Snacks Into the Campus on Feasibility, Perceived Efficacy, and Participation Perspectives in Inactive Young Adults: ARandomized Mixed-Methods Pilot Study.

This 6-week pilot study aimed to investigate the feasibility, perceived efficacy, and participation perspectives of a university campus stair climbing-based exercise snack (ES) intervention and to compare it to moderate-intensity continuous training (MICT). Healthy, young, inactive adults (age: 21.6 ± 2.3 years, BMI: 22.5 ± 3.6 kg/m2) were randomly assigned to three groups (ES, MICT, and Control [CON]). ES (n = 14, 6 females) and MICT (n = 13, 9 females) groups performed three sessions per week over 6 weeks, while the control group (n = 15, 9 females) maintained their habitual lifestyle. ES involved 3 × ~30 s 'all-out' stair-climbing (6 flights, total 126 steps and 18.9 m elevation) bouts separated by > 1 h rest, and MICT involved 40 min stationary cycling at 60%-70% HRmax. Mixed linear effect models were used to explore within and between-group differences, and the change in magnitude was determined using mean difference (MD), 95% confidence interval (CI), and Cohen's d effect size. Fourteen participants also completed post-intervention semi-structured interviews. Retention rates of 93% (ES, 14/15), 93% (MICT, 13/14), and 100% (CON, 15/15) were achieved from baseline to post-assessments, with compliance (participants' attendance to scheduled ES sessions) of 97% (733/756 sessions) and 93% (217/234 sessions) in ES and MICT, respectively. No significant differences were found between ES and MICT for future intentions (4.8 ± 1.4 and 5.0 ± 0.9), enjoyment (PACES, 89.0 ± 16.4 and 94.5 ± 11.9), and satisfaction. A significant group × time interaction was found in the quality of life and perceived stress. ES and MICT significantly increased the quality of life by 8% (MD = 5.5 [95% CI = 0.3, 10.7], Cohen's d = 0.64) and 6% (MD = 4.6 [95% CI = 0.9, 8.2], Cohen's d = 0.88) compared to baseline, whereas CON experienced a significant decrease (MD = -7.9 [95% CI = -14.4, -1.6], Cohen's d = 0.56). ES significantly decreased perceived stress by 7% (MD = -4.6 [95% CI = -8.9, -0.3], Cohen's d = 0.58), while MICT (MD = 2.0 [95% CI = -0.1, 4.1], Cohen's d = 0.28) and CON (MD = -2.4 [95% CI = -6.1, 1.3], Cohen's d = 0.22) had no significant effects. The majority (12/14) of participants generally demonstrated positive attitudes toward participation in ES and found it easier than expected while highlighting enablers, barriers, and future recommendations. Stair climbing-based ES could be integrated into the campus setting, appeared feasible, and was similar to MICT regarding future intentions, enjoyment, and satisfaction. Both ES and MICT might induce relevant positive effects on the quality of life, and ES demonstrated greater benefits compared to MICT or CON for reducing perceived stress. Interviews provided positive insights into fostering adherence to ES among university students.

Perches used as environmental enrichment influence fast-growth broilers' biomechanics and locomotor morphometry at the age of 42 days.

Currently available conventional breeding methods for broilers often result in impaired biomechanics and skeletal growth for the animals. The addition of environmental enrichment is an alternative which can help alleviate these effects. This study examines the effects of environmental enrichment on biomechanics, morphometry, and bone mass of broilers across various age groups. In total, 112 Cobb 500 chicks (50% male and 50% female) were used in a completely randomized design experiment, with 56 broilers per treatment (T1 and T2), carried out in subdivided plots. Each plot was subjected to a different treatment, as follows: all plots were subjected to the treatments (T1 = environmental enrichment and T2 = no environment enrichment) and the sub-plots held the broilers' age groups (1, 7, 14, 21, 28, 35 and 42 days old). Eight broilers were euthanized on a weekly basis for two production cycles in order to perform morphometric (diameter and length) and biomechanical analysis of the response variables. These measurements were performed on the femur and tibia. Birds were subjected to classical linear fixed effects model and compared through Tukey's mean test. Significant interactions between environmental enrichment and broiler age were noticed, particularly at 42 days, which displayed bone development for all variables under study. Except for the length of the femur of broiler chickens (p = 0.4638). Therefore, simple effects will not be evaluated. Environmental enrichment had a notable impact on tibia length (p = 0.0035), femur weight (p = 0.0014), and tibia weight (p<0.0001) at 42 days, indicating a favorable effect on skeletal growth in broilers. Enrichment resulted in a 1% increase in femur inertia, a 2% rise in tibia inertia, and a 1% enhancement in ultimate bending stress for both bones, displaying improved structural integrity and durability. Beneficial changes in bone morphology and biomechanics were observed at 42 days after enrichment.

Level 4 seizure monitoring unit admissions are associated with reduced long-term health care costs.

This study was undertaken to determine whether admission to dedicated seizure monitoring units (SMUs) result in reduced health care use (HCU). This was a retrospective open cohort study covering the years 2010-2018 of patients residing in Alberta, Canada, who were referred to the Calgary Comprehensive Epilepsy Program and admitted to a level 4 SMU. Patients were required to have ≥3 years pre- and postadmission follow-up. The outcome was the change in trajectory of composite HCU (primary care, specialist outpatient visits, emergency department visits, and hospitalizations) for the 3 years prior to and 3 years following SMU admission using the point of admission as the "index date." Secondary outcomes were HCU limited to specific settings. We excluded the first 30 days following the point of admission to mitigate the confounding admission would have on the postadmission HCU trajectory. We used adjusted restricted maximum likelihood linear and nonlinear effects models to determine trajectories expressed as Canadian dollars. A total of 315 of 600 (53%) patients met eligibility criteria. Mean age was 40 years (SD = 17.4), 176 (56%) were female, 220 (70%) had focal epilepsy, and 60 (19%) had functional seizures or physiologic seizure mimics without epilepsy as adjudicated by the attending physician at the point of discharge. Mean per person health care costs increased by CAD$341.28 (95% confidence interval [CI] = -25.17 to 707.74) for each successive 6-month interval prior to SMU admission (p = .07). Following admission, mean per person costs decreased by CAD$802.34 (95% CI = 699.62-905.06, p < .001) for each successive 6-month interval up to 3 years postdischarge. Similar trends were noted for primary and specialist care, emergency department, admitted care, and when nonlinear models were applied. Admission to an SMU is associated with significant and enduring declines in HCU. Each 6-months following discharge overall HCU declined by a mean of CAD$802.34 and acute inpatient, emergency department, and outpatient physician interactions declined by 25%, 26%, and 18% respectively. Comprehensive epilepsy care not only reduces morbidity and mortality but also reduces cost.

Associations between blood nickel and lung function in young Chinese: An observational study combining epidemiology and metabolomics

Associations between blood nickel and lung function in young Chinese: An observational study combining epidemiology and metabolomics

Prefrontal cortex activation under stress as a function of borderline personality disorder in female adolescents engaging in non-suicidal self-injury.

Neuroimaging studies suggest alterations in prefrontal cortex (PFC) activity in healthy adults under stress. Adolescents with non-suicidal self-injury (NSSI) report difficulties in stress and emotion regulation, which may be dependent on their level of borderline personality disorder (BPD). The aim was to examine alterations in the PFC in adolescents with NSSI during stress. Adolescents (13-17 years) engaging in non-suicidal self-injury (n = 30) and matched healthy controls (n = 29) performed a task with low cognitive demand and the Trier Social Stress Test (TSST). Mean PFC oxygenation across the PFC was measured with an eight-channel near-infrared spectroscopy system. Alongside self-reports on affect, dissociation and stress, BPD pathology was assessed via clinical interviews. Mixed linear-effect models revealed a significant effect of time on PFC oxygenation and a significant time×group interaction, indicating increased PFC activity in patients engaging in NSSI at the beginning of the TSST compared with healthy controls. Greater BPD symptoms overall were associated with an increase in PFC oxygenation during stress. In exploratory analyses, mixed models addressing changes in PFC connectivity over time as a function of BPD symptoms were significant only for the left PFC. Results indicate differences in the neural stress response in adolescents with NSSI in line with classic neuroimaging findings in adults with BPD. The link between PFC oxygenation and measures of BPD symptoms emphasises the need to further investigate adolescent risk-taking and self-harm across the spectrum of BPD, and maybe overall personality pathology, and could aid in the development of tailored therapeutic interventions.