327 research outputs found

    Social experiments and intrumental variables with duration outcomes

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    This paper examines the empirical analysis of treatment effects on duration outcomes from data that contain instrumental variation. We focus on social experiments in which an intention to treat is randomized and compliance may be imperfect. We distinguish between cases where the treatment starts at the moment of randomization and cases where it starts at a later point in time. We derive exclusion restrictions under various informational and behavioral assumptions and we analyze identifiability under these restrictions. It turns out that randomization (and by implication, instrumental variation) by itself is often insufficient for inference on interesting effects, and needs to be augmented by a semi-parametric structure. We develop corresponding non- and semi-parametric tests and estimation methods.Event-history analysis; intention to treat; non-compliance; policy evaluation; selection

    Dynamically assigned treatments: duration models, binary treatment models, and panel data models

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    Often, the moment of a treatment and the moment at which the outcome of interest occurs are realizations of stochastic processes with dependent unobserved determinants. Notably, both treatment and outcome are characterized by the moment they occur. We compare different methods of inference of the treatment effect, and we argue that the timing of the treatment relative to the outcome conveys useful information on the treatment effect, which is discarded in binary treatment frameworksProgram evaluation; treatment effects; bivariate duration analysis; selection bias; hazard rate; unobserved heterogeneity; fixed effects; random effects

    A simple procedure for the evaluation of treatment effects on duration variables

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    Often, a treatment and the outcome of interest are characterized by the moment they occur, and these moments are realizations of stochastic processes with dependent unobserved determinants. We develop a simple and intuitive method for inference on the treatment effect. The method can be implemented as a graphical procedure or as a straightforward parameter test in an auxiliary univariate single-spell duration model. The method exploits information on the timing of the treatment relative to the outcome that is discarded in binary treatment analyses.Duration analysis; hazard rate; selectivity bias; treatment effect; unobserved heterogeneity

    Cognitive control deficits in pediatric frontal lobe epilepsy

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    Executive dysfunction and behavioral problems are common in children with epilepsy. Inhibition and shifting, both aspects of cognitive control, seem related to behavior problems and are thought to be driven mainly by the frontal lobes. We investigated if inhibition and shifting deficits are present in children with frontal lobe epilepsy (FLE). Secondly, we studied the relationship between these deficits and behavior problems. Thirty-one children were administered the Stroop Color Word Test and a digital version of the Wisconsin Card Sorting Test (WCST). Parents completed the Behavioral Rating Inventory for Executive Function (BRIEF) and the Achenbach scale (Child Behavior Checklist (CBCL)). About 20% of the children displayed significant low results on the Stroop Effect. About 60% showed shifting problems on the WCST. Parents reported cognitive control and behavioral deficits in about a third of the children. Also, behavioral problems and deficits in inhibition and shifting in daily life (BRIEF) seem to be related. There were no correlations between questionnaires and the Stroop and the WCST. Only in the group of children with many perseverative errors there were especially high correlations between Inhibit of the BRIEF

    Bellcore attack in practice

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    In this paper we analyze practical aspects of the differential fault attack on RSA published by Boneh, Demillo and Lipton from Bellcore. We focus on the CRT variant, which requires only one faulty signature to be entirely broken provided that no DFA countermeasures are in use. Usually the easiest approach for the attacker is to introduce a fault in one of the two RSA-CRT exponentiations. These are time-consuming and often clearly visible in the power profiles. However, protection of the exponentiations against faults does not always circumvent the Bellcore attack. Our goal is to investigate and classify other possible targets of the attack

    Web-based guided self-help cognitive behavioral therapy–enhanced versus treatment as usual for binge-eating disorder: a randomized controlled trial protocol

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    Binge-eating disorder (BED) is a psychiatric disorder characterized by recurrent episodes of eating a large amount of food in a discrete period of time while experiencing a loss of control. Cognitive behavioral therapy-enhanced (CBT-E) is a recommended treatment for binge-eating disorder and is typically offered through 20 sessions. Although binge-eating disorder is highly responsive to CBT-E, the cost of treating these patients is high. Therefore, it is crucial to evaluate the efficacy of low-intensity and low-cost treatments for binge-eating disorder that can be offered as a first line of treatment and be widely disseminated. The proposed noninferiority randomized controlled trial aims to determine the efficacy of web-based guided self-help CBT-E compared to treatment-as-usual CBT-E. Guided self-help will be based on a self-help program to stop binge eating, will be shorter in duration and lower intensity, and will require fewer therapist hours. Patients with binge-eating disorder (N = 180) will be randomly assigned to receive guided self-help or treatment-as-usual. Assessments will take place at baseline, mid-treatment, at the end of treatment, and at 20- and 40-weeks post-treatment. Treatment efficacy will be measured by examining the reduction in binge-eating days in the previous 28 days between baseline and the end of treatment between groups, with a noninferiority margin (Δ) of 1 binge-eating day. Secondary outcomes will include full remission, body shape dissatisfaction, therapeutic alliance, clinical impairment, health-related quality of life, attrition, and an economic evaluation to assess cost-effectiveness and cost-utility. The moderators examined will be baseline scores, demographic variables, and body mass index. It is expected that guided self-help is noninferior in efficacy compared to treatment-as-usual. The proposed study will be the first to directly compare the efficacy and economically evaluate a low-intensity and low-cost binge-eating disorder treatment compared to treatment-as-usual. If guided self-help is noninferior to treatment-as-usual in efficacy, it can be widely disseminated and used as a first line of treatment for patients with binge-eating disorder. The Dutch trial register number is R21.016. The study has been approved by the Medical Research Ethics Committees United on May 25th, 2021, case number NL76368.100.21

    Analysis of plasma enhanced pulsed laser deposition of transition metal oxide thin films using medium energy ion scattering

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    In this study, plasma-enhanced pulsed laser deposition (PE-PLD), which is a novel variant of pulsed laser deposition that combines laser ablation of metal targets with an electrically-produced oxygen plasma background, has been used for the fabrication of ZnO and Cu2O thin films. Samples prepared using the PE-PLD process, with the aim of generating desirable properties for a range of electrical and optical applications, have been analysed using medium energy ion scattering. Using a 100 keV He+ ion beam, high resolution depth profiling of the films was performed with an analysis of the stoichiometry and interface abruptness of these novel materials. It was found that the PE-PLD process can create stoichiometric thin films, the uniformity of which can be controlled by varying the power of the inductively coupled plasma. This technique showed a high deposition rate of ∼0.1 nm s−1
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