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Optimization of Through-Time Radial Grappa with Coil Compression and Weight Sharing
No full textPurpose: This work proposes principal component analysis (PCA) coil compression and weight sharing to reduce acquisition and reconstruction time of through-time radial GRAPPA. Methods: Through-time radial GRAPPA enables ungated free-breathing motion-resolved cardiac imaging but requires a long calibration acquisition and GRAPPA weight calculation time. PCA coil compression reduces calibration data requirements and associated acquisition time, and weight sharing reduces the number of unique GRAPPA weight sets and associated weight computation time. In vivo cardiac data reconstructed with coil compression and weight sharing are compared to a gold standard to demonstrate improvement in calibration acquisition and reconstruction performance with minimal loss of image quality. Results: Coil compression from 30 physical to 12 virtual coils (90% of signal variance) decreases requisite calibration data by 60%, reducing calibration acquisition time to 6.7 s/slice from 31.5 s/slice reported in original through-time radial GRAPPA work. Resulting images have small increase in RMS error (RMSE). Reconstruction with a weight sharing factor of 8 results in eight-fold reduction in GRAPPA weight calculation time with a comparable RMSE to reconstructions with no weight sharing. Optimized parameters for coil compression and weight sharing applied to reconstructions enables images to be collected with a temporal resolution of 66 ms/frame and spatial resolution of 2.34 × 2.34 mm while reducing calibration acquisition time from 34 to 6.7 s, weight calculation time from 200 to 3 s, and weight application time 18 to 5 s. Conclusion: Coil compression and weight sharing applied to through-time radial GRAPPA enables fast free-breathing ungated cardiac cine without compromising image quality
A Mixed-Methods, Cross-Sectional Study of Perceived Stigma Among Ugandans with Epilepsy
No full textBackground: Epilepsy is associated with stigma and negatively impacts the lives of people living with epilepsy (PLWE) and their immediate families. More understanding of the stigma and discrimination experienced by PLWE in sub-Saharan Africa is needed. Methods: In a cross-sectional, mixed methods study, forty- eight PLWE who met the study inclusion criteria were enrolled. In depth interviews and focus group discussions were conducted and were audiotaped and transcribed verbatim. Analysis was conducted using a thematic, constant comparative approach with an emphasis on dominant themes. Perceived stigma was measured using the Kilifi epilepsy stigma score. Associations between socio-demographic factors and Kilifi epilepsy stigma score were assessed. Results: The median age of the study participants was 25 years, with median age (IQR) of epilepsy onset of 12 (6-18) years. The prevalence of high-perceived stigma was 31.9% (15/48). Seizure frequency was associated with high levels of perceived stigma (p-value of 0.038). Psychological abuse, rejections at home, places of employment and schools, poor relationships and intimacy and unmet engagements in social activities were cited as the perceived stigmatizing aspects among PLWE. Conclusion: In this Ugandan sample perceived stigma remains unacceptably high and interventions to address it are urgently needed in our settings
An Interventional Pilot of Customized Adherence Enhancement Combined with Long-Acting Injectable Antipsychotic Medication (CAE-L) for Poorly Adherent Patients With Chronic Psychotic Disorder in Tanzania
No full textBackground: Chronic psychotic disorders (CPD) impose a particularly significant burden in resource-limited settings. Combining long-acting antipsychotic medication (LAI) with a customized adherence enhancement intervention (CAE-L) has potential to advance care. Methods: Nineteen adults ≥ age 18 with CPD who self-reported missing ≥20% of antipsychotic medication within the last month were stabilized on oral haloperidol prior to transitioning to monthly haloperidol decanote for 25 weeks. Outcome evaluations were conducted at baseline and Week 25. Primary outcomes were oral medication adherence assessed via the Tablet Routines Questionnaire (TRQ) and LAI injection frequency. Secondary outcomes included CPD symptoms measured by the Brief Psychiatric Rating Scale and Clinical Global Impressions, functioning evaluated using the Social and Occupational Functioning Scale, and medication attitudes assessed with the Drug Attitudes Inventory. Results: Mean sample age was 38.79 (SD = 9.31) with 18 individuals completing the study. There was one serious adverse event, a relapse into substance use, not deemed study-related. Mean endpoint LAI dosage was 65.79 mg (SD = 22.38). TRQ mean scores were 21.84 (SD =13.83) and 12.94 (SD = 11.93) at screen and baseline respectively. For only two individuals who were on concomitant oral medication at 25 weeks, TRQ change was not calculated. LAI injection frequency was 100%. Medication attitudes scores significantly improved from 7.89 (SD = 2.72) to 9.83 (SD = 0.52) (p =.001.) Changes in CPD symptoms and functioning were non-significant. Conclusions: CAE-L appears to be preliminarily feasible and acceptable in Tanzanians with CPD. Trial registration: The study was registered on ClinicalTrials.gov (NCT04327843) on March 31, 2020
Directly Observed Weekly Fluoxetine for Major Depressive Disorder Among Hemodialysis Patients: A Single-Arm Feasibility Trial
No full textRationale & Objective: Major depressive disorder (MDD) is common among hemodialysis patients, but treatment can add to their pill burden and may be limited by nonadherence. We sought to investigate the value of directly observed, once-weekly fluoxetine dosing in MDD. Study Design: Feasibility trial of adult hemodialysis patients with untreated MDD. The diagnosis of MDD was determined using the Mini International Neuropsychiatric Interview. Setting & Participants: 16 patients at 15 hemodialysis facilities in Northeast Ohio. Intervention: Patients were initially prescribed 20 mg of fluoxetine once daily for 2 weeks to assess their tolerance. The patients took this daily fluoxetine unobserved at home. They were then transitioned to 90 mg of fluoxetine once weekly for 10 weeks. The patients took this weekly fluoxetine during hemodialysis treatment and were observed by the study staff. The dose was increased to 180 mg once weekly among patients with an inadequate response based on the judgment of the prescribing clinician. Outcomes: Mini International Neuropsychiatric Interview diagnosis of MDD at the end of the trial and changes in the Patient Health Questionnaire (PHQ-9) scores over 12 weeks. Results: One patient withdrew from active treatment after 2 daily doses of 20 mg of fluoxetine because of side effects of stomach cramping, vomiting, dizziness, and lightheadedness but completed the baseline and final assessments. The remaining 15 patients received all scheduled weekly fluoxetine doses during the trial. At 12 weeks, 14 of 16 patients (87.5%) no longer met the criteria for MDD (P \u3c 0.001). Among all participants, the mean PHQ-9 scores decreased from 11.3 to 6.6 (P = 0.002). Limitations: Small sample size, modestly elevated baseline PHQ-9 scores, no comparison group, and short treatment duration. Conclusions: Directly observed, once-weekly fluoxetine may be an effective and well-tolerated treatment option for hemodialysis patients. Future research should investigate longer-term health outcomes of weekly fluoxetine in this population and explore the feasibility of implementing this depression treatment model in routine clinical practice. Trial Registration: This trial was registered at clinicaltrials.gov as NCT03390933
The Effect of Objectively Collected Medication Adherence Information on Bipolar I and Major Depressive Disorder Treatment Decisions: A Randomized Case Vignette Study of Psychiatric Clinicians
No full textBackground: Adherence to antipsychotic medications is critical for treatment and relapse prevention in serious mental illness. Accurate assessment of medication adherence can be difficult, clinicians frequently overestimate patient adherence, and new accurate methods assessing medication adherence are needed. This study estimated the influence of antipsychotic medication adherence information on clinician treatment decisions among patients with bipolar I (BD) and major depressive (MDD) disorders. Methods: This study was a cross-sectional, random assignment survey of psychiatric clinicians who prescribe medication for the treatment of BD and/or MDD. Clinicians (N = 180) were recruited using national association lists and were presented with either BD or MDD case vignettes that described symptoms, level of functioning, and self-reported medication adherence. Cases were randomly assigned to vignettes that presented subjective (self-report) or objective adherence (from refill rates and MEMS caps data) information. Respondents were asked to recommend adjustments in medication regimen. Results: A total of 180 clinicians participated. In the BD arm (N = 90), participants were primarily female (55.5%), and specialized in psychiatry (97.8%). In the MDD arm (N = 90), participants were primarily female (64.4%) and specialized in psychiatry (98.9%). The BD arm was more likely to modify antipsychotic treatment as opposed to mood stabilizers and the MDD arm was more likely to modify antidepressant treatment as opposed to antipsychotic prescriptions. Among vignettes indicating non-adherence, cases that reviewed objective adherence data were more likely to adopt medication adherence enhancing interventions including long-acting injectable antipsychotics. As expected, the rate of LAI choice overall was greater for cases reviewing BD compared to those reviewing MDD vignettes. Limitations: This study utilized a convenience sample and synthetic vignettes. The survey response arrays do not cover the full array of treatment options available to all clinicians. Conclusions: These data suggest the presence of objective adherence data may help clinicians distinguish between medication nonresponse and medication nonadherence as illustrated by the relationship between the presence of objective adherence information and selection of treatment modifications
Mediating Role of Leadership-led Change in Adoption of Waste-to-Energy in Nigeria
Get PDFThe use of renewable energy has increased in the past several years. Innovative forms of sustainable alternative energy production, such as solar and wind, are well-recognized energy sources. This paper reviews waste-to-energy (WtE), an innovative and evolving form of renewable energy, and its possible adoption in Nigeria to address this nation’s energy crisis and pollution problem. The theoretical framework of this paper draws from the theory of reasoned action (TRA) and the leadership-led change framework to consider the role of leaders and their influence to adopt WtE. Four factors act as antecedents to the formation of attitudes and subjective norms about WtE, which then affect intentions to adopt WtE. Intentions then become a predictor of behavior for adopting WtE. Through this framework, we examine the predicted potential for WtE as a solution for energy and pollution issues in Nigeria. We modeled leadership-led change as a mediator in the relationship between attitude and intention to adopt WtE in Nigeria. Our results show that leadership-led change partially mediates the attitude–intention relationship in the adoption of WtE. This paper makes two contributions: First, we offer an empirical account of Nigerian leaders’ intention to adopt WtE as a solution for its energy and environmental problems; and second, we offer an extended TRA model that incorporates a leadership-led change framework
Seroprevalence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-Cov-2) Among Healthcare Providers Prior to the Vaccine Era in an Integrated Midwestern Healthcare System
Get PDFWe performed severe acute respiratory coronavirus virus 2 (SARS-CoV-2) antinucleocapsid IgG testing on 5,557 healthcare providers and found a seroprevalence of 3.9%. African Americans were more likely to test positive than Whites, and HCWs with household exposure and those working on COVID-19 cohorting units were more likely to test positive than their peers
Low Voltage-Guided Ablation of Posterior Wall Improves 5-Year Arrhythmia-Free Survival in Persistent Atrial Fibrillation
Get PDFIntroduction: The posterior wall (PW) has been proposed as a standard target for ablation beyond pulmonary vein antral isolation (PVI) in patients with persistent atrial fibrillation (AF). However, studies have shown inconsistent outcomes with the addition of PW ablation. The presence or absence of low voltage on the PW may explain these inconsistencies. We evaluated whether PW ablation based on the presence or absence of low voltage improves long-term arrhythmia-free outcomes. Methods: We retrospectively reviewed 5-year follow-up in 152 consecutive patients who received either standard ablation (SA) with PVI alone or PVI + PW ablation (PWA) based on physician discretion (n = 77) or voltage-guided ablation (VGA) with PVI and addition of PWA only if low voltage was present on the PW (n = 75). Results: The two groups were well matched for baseline characteristics. At 5-year follow-up, 64% of patients receiving VGA were atrial tachyarrhythmia (AT)/AF free compared to 34% receiving SA (HR 0.358 p \u3c .005). PWA had similar AF recurrence in SA and VGA groups (0.30 vs. 0.27 p = .96) but higher AT recurrence when comparing SA and VGA groups (0.39 vs. 0.15 p = .03). In multivariate analysis, both VGA and PWA predicted AF arrhythmia-free survival (HR 0.33, p = .001 and HR 0.20, p = .008, respectively). For AT, VGA predicted arrhythmia-free survival (HR 0.22, p = .028), while PWA predicted AT recurrence (HR 4.704, p = .0219). Conclusion: VGA of the posterior wall ablation beyond PVI in persistent AF significantly improves long-term arrhythmia-free survival when compared with non-voltage-guided ablation. PW ablation without voltage-guidance reduced AF recurrence but at the cost of a higher incidence of AT
Stellar Mass-to-light Ratios: Composite Bulge+Disk Models and the Baryonic Tully-Fisher Relation
Get PDFWe present stellar population models to calculate the mass-to-light ratio (Γ∗) based on galaxies\u27 colors ranging from GALEX far-UV to Spitzer IRAC1 at 3.6 μm. We present a new composite bulge+disk Γ∗ model that considers the varying contribution from bulges and disks based on their optical and near-IR colors. Using these colors, we build plausible star formation histories and chemical enrichment scenarios based on the star formation rate-stellar mass and mass-metallicity correlations for star-forming galaxies. The most accurate prescription is to use the actual colors for the bulge and disk components to constrain Γ∗; however, a reasonable bulge+disk model plus total color only introduces 5% more uncertainty. Full bulge+disk Γ∗ prescriptions applied to the baryonic Tully-Fisher relation improve the linearity of the correlation, increase the slope, and reduce the total scatter by 4%
Chirality in Light–Matter Interaction
No full textThe scientific effort to control the interaction between light and matter has grown exponentially in the last 2 decades. This growth has been aided by the development of scientific and technological tools enabling the manipulation of light at deeply sub-wavelength scales, unlocking a large variety of novel phenomena spanning traditionally distant research areas. Here, the role of chirality in light–matter interactions is reviewed by providing a broad overview of its properties, materials, and applications. A perspective on future developments is highlighted, including the growing role of machine learning in designing advanced chiroptical materials to enhance and control light–matter interactions across several scales
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