Trait anxiety and unplanned delivery mode enhance the risk for childbirth-related post-traumatic stress disorder symptoms in women with and without risk of preterm birth: A multi sample path analysis

Childbirth-related post-traumatic stress disorder (CB-PTSD) occurs in 3–7% of all pregnancies and about 35% of women after preterm birth (PTB) meet the criteria for acute stress reaction. Known risk factors are trait anxiety and pain intensity, whereas planned delivery mode, medical support, and positive childbirth experience are protective factors. It has not yet been investigated whether the effects of anxiety and delivery mode are mediated by other factors, and whether a PTB-risk alters these relationships. 284 women were investigated antepartum and six weeks postpartum (risk-group with preterm birth (RG-PB) N = 95, risk-group with term birth (RG-TB) N = 99, and control group (CG) N = 90). CB-PTSD symptoms and anxiety were measured using standardized psychological questionnaires. Pain intensity, medical support, and childbirth experience were assessed by single items. Delivery modes were subdivided into planned vs. unplanned delivery modes. Group differences were examined using MANOVA. To examine direct and indirect effects on CB-PTSD symptoms, a multi-sample path analysis was performed. Rates of PTS were highest in the RG-PB = 11.58% (RG-TB = 7.01%, CG = 1.1%). MANOVA revealed higher values of CB-PTSD symptoms and pain intensity in RG-PB compared to RG-TB and CG. Women with planned delivery mode reported a more positive birth experience. Path modeling revealed a good model fit. Explained variance was highest in RG-PB (R2 = 44.7%). Direct enhancing effects of trait anxiety and indirect reducing effects of planned delivery mode on CB-PTSD symptoms were observed in all groups. In both risk groups, CB-PTSD symptoms were indirectly reduced via support by medical staff and positive childbirth experience, while trait anxiety indirectly enhanced CB-PTSD symptoms via pain intensity in the CG. Especially in the RG-PB, a positive birth experience serves as protective factor against CB-PTSD symptoms. Therefore, our data highlights the importance of involving patients in the decision process even under stressful birth conditions and the need for psychological support antepartum, mainly in patients with PTB-risk and anxious traits. Trial registration number: NCT01974531 (ClinicalTrials.gov identifier).

Testing Campus-Class-Technology Theory in Student Engagement: A Large Sample Path Analysis

Student engagement refers to the quality and quantity of students’ psychological, cognitive, emotional and behavioral reactions to in-class and out-of-class academic and social activities to achieve successful learning outcomes. In literature, the Campus-Class-Technology (CCT) theory in student engagement was developed and tested with some models, which had certain limitations. Thus, the present study aimed to test the CCT theory with a new and more advanced model. The study was carried out using the quantitative research design and conducted with 3967 students, and the models were tested using path analysis. The research data were collected using the research instruments regarding student engagement, technology integration and campus climate. Four CCT models were developed and tested. The results revealed that all the models were confirmed. In general, what the models explained in the study was that technology integration and benefiting from campus facilities increased student engagement and student success.

PENGARUH FIRM SIZE DAN GROWTH OPPORTUNITY TERHADAP CASH HOLDING DAN FIRM VALUE

This research aims to determine the effect of firm size and growth opportunity to cash holding and firm value. Manufacturing companies that listed in Indonesian Stock Exchange are used as population. Annual ?nancial data of 38 ?rms from manufacturing companies listed on Indonesian Stock Exchange from 2013 to 2016 examined as sample. Path analysis technique used to analysis hypothesis of the research by SPSS software. The results showed that: firm size and growth opportunity had positive and significant impact on firm value. Firm size had negative and significant impact on cash holding. Growth opportunity had positive and significant impact on cash holding. Cash holding had positive and significant impact on firm value. Cash holding mediated the effect of growth opportunity on firm value significantly.

Stochastic impulse control of exchange rates with Freidlin–Wentzell perturbations

This paper pioneers a Freidlin–Wentzell approach to stochastic impulse control of exchange rates when the central bank desires to maintain a target zone. Pressure to stimulate the economy forces the bank to implement diffusion monetary policy involving Freidlin–Wentzell perturbations indexed by a parameter ε∈ [0,1]. If ε=0, the policy keeps exchange rates in the target zone for all times t≥0. When ε>0, exchange rates continually exit the target zone almost surely, triggering central bank interventions which force currencies back into the zone or abandonment of all targets. Interventions and target zone deviations are costly, motivating the bank to minimize these joint costs for any ε∈ [0,1]. We prove convergence of the value functions as ε→0 achieving a value function approximation for small ε. Via sample path analysis and cost function bounds, intervention followed by target zone abandonment emerges as the optimal policy.

Asymptotic Time Averages and Frequency Distributions

Consider an arbitrary nonnegative deterministic process (in a stochastic setting {X(t), t≥0} is a fixed realization, i.e., sample-path of the underlying stochastic process) with state space S=(-∞,∞). Using a sample-path approach, we give necessary and sufficient conditions for the long-run time average of a measurable function of process to be equal to the expectation taken with respect to the same measurable function of its long-run frequency distribution. The results are further extended to allow unrestricted parameter (time) space. Examples are provided to show that our condition is not superfluous and that it is weaker than uniform integrability. The case of discrete-time processes is also considered. The relationship to previously known sufficient conditions, usually given in stochastic settings, will also be discussed. Our approach is applied to regenerative processes and an extension of a well-known result is given. For researchers interested in sample-path analysis, our results will give them the choice to work with the time average of a process or its frequency distribution function and go back and forth between the two under a mild condition.

Sample-Path Analysis of Single-Server Queue with Multiple Vacations

We a give deterministic (sample path) proof of a result that extends the Pollaczek-Khintchine formula for a multiple vacation single-server queueing model. We also give a conservation law for the same system with multiple classes. Our results are completely rigorous and hold under weaker assumptions than those given in the literature. We do not make stochastic assumptions, so the results hold almost surely on every sample path of the stochastic process that describes the system evolution. The article is self contained in that it gives a brief review of necessary background material.