3,563 research outputs found
Direct measurement of penetration length in ultra-thin and/or mesoscopic superconducting structures
We describe a method for direct measurement of the magnetic penetration
length in thin (10 - 100 nm) superconducting structures having overall
dimensions in the range 1 to 100 micrometers. The method is applicable for
broadband magnetic fields from dc to MHz frequencies.Comment: Accepted by Journal of Applied P:hysics (Jun 2006).5 pages, 5 figure
Degenerate ground state and anomalous flux hysteresis in an YBa2Cu3O7 grain boundary r.f. SQUID
We report measurements of the flux hysteresis curves and trapped flux
distribution in an YBa2Cu3O7 r.f. SQUID containing two closely spaced grain
boundary Josephson junctions in parallel. Broadening of the flux distribution
from T = 15 K to 30 K is followed by a bifurcation at T = 35 K which
corresponds to a degenerate ground state. Above T ~ 40 K the bifurcation
disappears, the flux distribution narrows significantly and small secondary
loops appear in the hysteresis curves. This behaviour can be modelled
qualitatively if we assume a temperature dependent second harmonic term in the
current-phase relationship of the junctions.Comment: 10 pages, 7 figure
A Randomized Depression Prevention Trial Comparing Interpersonal Psychotherapy—Adolescent Skills Training To Group Counseling In Schools
Given the rise in depression disorders in adolescence, it is important to develop and study depression prevention programs for this age group. The current study examined the efficacy of Interpersonal Psychotherapy-Adolescent Skills Training (IPT-AST), a group prevention program for adolescent depression, in comparison to group programs that are typically delivered in school settings. In this indicated prevention trial, 186 adolescents with elevated depression symptoms were randomized to receive IPT-AST delivered by research staff or group counseling (GC) delivered by school counselors. Hierarchical linear modeling examined differences in rates of change in depressive symptoms and overall functioning from baseline to the 6-month follow-up assessment. Cox regression compared rates of depression diagnoses. Adolescents in IPT-AST showed significantly greater improvements in self-reported depressive symptoms and evaluator-rated overall functioning than GC adolescents from baseline to the 6-month follow-up. However, there were no significant differences between the two conditions in onset of depression diagnoses. Although both intervention conditions demonstrated significant improvements in depressive symptoms and overall functioning, results indicate that IPT-AST has modest benefits over groups run by school counselors which were matched on frequency and duration of sessions. In particular, IPT-AST outperformed GC in reduction of depressive symptoms and improvements in overall functioning. These findings point to the clinical utility of this depression prevention program, at least in the short-term. Additional follow-up is needed to determine the long-term effects of IPT-AST, relative to GC, particularly in preventing depression onset
An automated and versatile ultra-low temperature SQUID magnetometer
We present the design and construction of a SQUID-based magnetometer for
operation down to temperatures T = 10 mK, while retaining the compatibility
with the sample holders typically used in commercial SQUID magnetometers. The
system is based on a dc-SQUID coupled to a second-order gradiometer. The sample
is placed inside the plastic mixing chamber of a dilution refrigerator and is
thermalized directly by the 3He flow. The movement though the pickup coils is
obtained by lifting the whole dilution refrigerator insert. A home-developed
software provides full automation and an easy user interface.Comment: RevTex, 10 pages, 10 eps figures. High-resolution figures available
upon reques
Effects of transcranial direct current stimulation in children and young people with psychiatric disorders: a systematic review.
Transcranial direct current stimulation (tDCS) has demonstrated benefits in adults with various psychiatric disorders, but its clinical utility in children and young people (CYP) remains unclear. This PRISMA systematic review used published and ongoing studies to examine the effects of tDCS on disorder-specific symptoms, mood and neurocognition in CYP with psychiatric disorders. We searched Medline via PubMed, Embase, PsychINFO via OVID, and Clinicaltrials.gov up to December 2022. Eligible studies involved multiple session (i.e., treatment) tDCS in CYP (≤ 25 years old) with psychiatric disorders. Two independent raters assessed the eligibility of studies and extracted data using a custom-built form. Of 33 eligible studies (participant N = 517), the majority (n = 27) reported an improvement in at least one outcome measure of disorder-specific symptoms. Few studies (n = 13) examined tDCS effects on mood and/or neurocognition, but findings were mainly positive. Overall, tDCS was well tolerated with minimal side effects. Of 11 eligible ongoing studies, many are sham-controlled RCTs (n = 9) with better blinding techniques and a larger estimated participant enrolment (M = 79.7; range 15-172) than published studies. Although encouraging, the evidence to date is insufficient to firmly conclude that tDCS can improve clinical symptoms, mood, or cognition in CYP with psychiatric disorders. Ongoing studies appear of improved methodological quality; however, future studies should broaden outcome measures to more comprehensively assess the effects of tDCS and develop dosage guidance (i.e., treatment regimens). [Abstract copyright: © 2023. The Author(s).
Development and Evaluation of a Pragmatic Measure of Adherence to Dialectical Behavior Therapy: The DBT Adherence Checklist for Individual Therapy
This paper presents two studies conducted to develop and evaluate a new pragmatic measure of therapist adherence to Dialectical Behavior Therapy (DBT): the DBT Adherence Checklist for Individual Therapy (DBT AC-I). Study 1 used item response analysis to select items from the gold standard DBT Adherence Coding Scale (DBT ACS) using archival data from 1271 DBT sessions. Items were then iteratively refined based on feedback from 33 target end-users to ensure relevance, usability, and understandability. Study 2 examined the psychometric properties of the DBT AC-I as a therapist self-report and observer-rated measure in 100 sessions from 50 therapist-client dyads, while also evaluating predictors of therapist accuracy in self-rated adherence. When used as a therapist self-report measure, concordance between therapist and observer ratings was at least moderate (AC1≥0.41) for all DBT AC-I items but overall concordance (ICC=0.09) as well as convergent (r=0.05) and criterion validity (AUC=0.54) with the DBT ACS were poor. Higher therapist accuracy was predicted by greater DBT knowledge and adherence as well as more severe client suicidal ideation. When used by trained observers, the DBT AC-I had excellent interrater reliability (ICC=0.93), convergent validity (r=0.90), and criterion validity (AUC=0.94). While therapists’ self-rated adherence on the DBT AC-I should not be assumed to reflect their actual adherence, some therapists may self-rate accurately. The DBT AC-I offers an effective and relatively efficient method of evaluating adherence to DBT when used by trained observers
Association of the Sweet-Liking Phenotype and Craving for Alcohol With the Response to Naltrexone Treatment in Alcohol Dependence: A Randomized Clinical Trial
Identification of moderators of the response to naltrexone hydrochloride treatment for alcohol dependence could improve clinical care for patients with alcohol use disorders. To investigate the preliminary finding that the sweet-liking (SL) phenotype interacts with a high level of craving for alcohol and is associated with an improved response to naltrexone in alcohol dependence. This 12-week double-blind, randomized, placebo-controlled clinical trial was conducted from February 1, 2010, to April 30, 2012, in an academic outpatient medical center. Eighty actively drinking patients were randomized by the SL (n = 22) or the sweet-disliking (SDL) (n = 58) phenotype and by pretreatment high (n = 40) or low (n = 40) craving for alcohol, with high craving defined as greater than the median. Patients and staff were blinded to categorization. Patients were excluded for unstable medical or psychiatric illness, including dependence on drugs other than nicotine. Four patients (2 in the placebo arm and 2 in the naltrexone arm) stopped medication therapy because of adverse effects. Data were analyzed from January 15, 2013, to May 15, 2016, based on intention to treat. Oral naltrexone hydrochloride, 50 mg/d, or daily placebo with weekly to biweekly brief counseling. The a priori hypothesis tested SL/SDL phenotype, pretreatment craving, and their interaction as moderators of frequency of abstinent and heavy drinking days during treatment, assessed with the timeline follow-back method. Eighty patients were randomized (57 men [71%]; 23 women [29%]; mean [SD] age, 47.0 [8.6] years). A nonsignificant effect of naltrexone on heavy drinking was noted (4.8 fewer heavy drinking days; Cohen d = 0.45; 95% CI, -0.01 to 0.90; F1,67 = 3.52; P = .07). The SL phenotype moderated the effect of naltrexone on heavy drinking (6.1 fewer heavy drinking days; Cohen d = 0.58; 95% CI, 0.12-1.03; F1,67 = 5.65; P = .02) and abstinence (10.0 more abstinent days; Cohen d = 0.57; 95% CI, 0.11-1.02; F1,67 = 5.36; P = .02), and high craving moderated heavy drinking (7.1 fewer heavy drinking days; Cohen d = 0.66; 95% CI, 0.20-1.11; F1,67 = 7.37; P = .008). The combination of the SL phenotype and high craving was associated with a strong response to naltrexone, with 17.1 fewer heavy drinking days (Cohen d = 1.07; 95% CI, 0.58-1.54; F1,67 = 19.33; P < .001) and 28.8 more abstinent days (Cohen d = 0.72; 95% CI, 0.25-1.17; F1,67 = 8.73; P = .004) compared with placebo. The SL phenotype and a high craving for alcohol independently and particularly in combination are associated with a positive response to naltrexone. The SL/SDL phenotype and a high craving for alcohol merit further investigation as factors to identify patients with alcohol dependence who are responsive to naltrexone. clinicaltrials.gov Identifier: NCT01296646
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