Sensitivity Analysis of the No-Omitted Confounder Assumption in Latent Growth Curve Mediation Models

Latent growth curve mediation models are increasingly used to assess mechanisms of behavior change. For latent growth mediation model, like any another mediation model, even with random treatment assignment, a critical but untestable assumption for valid and unbiased estimates of the indirect effects is that there should be no omitted variable that confounds indirect effects. One way to address this untestable assumption is to conduct sensitivity analysis to assess whether the inference about an indirect effect would change under varying degrees of confounding bias. We developed a sensitivity analysis technique for a latent growth curve mediation model. We compute the biasing effect of confounding on point and confidence interval estimates of the indirect effects in a structural equation modeling framework. We illustrate sensitivity plots to visualize the effects of confounding on each indirect effect and present an empirical example to illustrate the application of the sensitivity analysis.     

The Structure of Peers: The Impact of Peer Networks on Academic Achievement

Research in Higher Education - Peer effects are an important contributing factor in the learning process. Most of the prior literature on peer effects focuses on the characteristics of peers rather...     

An Organizational Consultation Framework for School-Based Prevention of Commercial Sexual Exploitation of Children

ABSTRACT

The commercial sexual exploitation of children (CSEC) is a form of childhood sexual abuse involving the sexual exploitation of youth for economic gain. School-based CSEC prevention efforts have increased in recent years. While these efforts represent important progress in school-based efforts to prevent CSEC, the literature indicates that they need to be strengthened. This article presents a school-based organizational consultation framework that may help schools and support personnel to enhance existing school-based CSEC prevention efforts.     

Smooth new world: Agency and Utopia

The New World Embassy was created by Dutch artist and activist Jonas Staal and Tuareg activist Moussa Ag Assarid in 2014 as an art installation to represent the recently established state of Azawad. This new state, currently unrecognised, seceded from Mali in 2012 after a brief armed struggle. An analysis of the spatialities of the New World Embassy, and of the region it represents, enables its interpretation as a critical utopia, a heterotopia, and as an example of smooth space. Such an analysis furthermore clarifies the underlying sociopolitical dynamic in the region, and in its newly established Embassy, as the contestation, by the other, of the oppressive geopolitical practices and institutions of the same. Lastly, the spatialities of the Embassy exemplifies a particular mode of agentic worldmaking.     

Identifying Indicators of Behavior Change: Insights From Wildfire Education Programs

Environmental educators are challenged to document behavior changes, because change rarely depends solely on outcomes of education programs, but on many factors. An analysis of 15 communities in the United States that have increased their preparedness for wildfire allowed us to explore how education programs encouraged individual and community change. Agency-sponsored adult educational programs helped communities change their philosophy about firefighting, pass ordinances that restrict individual property rights, and empower residents to reduce their wildfire risk. This article explores several outcomes of these programs and offers suggested indicators of change that might be useful for education program evaluation.     

Information management as an enabler of knowledge management maturity: A South African perspective

This paper explores the much ignored but critically important subject of the perceived relationship between information and communications technology (ICT), information management (IM) and knowledge management (KM). Defining the border between ICT, IM and KM, and especially the maturity remains a highly debatable topic. These issues could be concisely summarized as being diverse and problematic and located across the spectrum of views. Prior studies suggest that even though KM is strongly entrenched and rests on the foundation of ICT and IM, very little is reported in the literature on ICT and IM as enablers to KM. From a large urban South African University engaged in numerous collaboration programs with industry, the authors gained insight into growth of KM maturity in industry groupings over a 5-year period. The authors applied an inventory developed by Kruger and Snyman [Kruger, C. J., & Snyman, M. M. M. (2007). A guideline for assessing the knowledge management maturity of organizations. South African Journal of Information Management,9(3). Electronic Journal [Online]. Available www.sajim.co.za. Accessed 15 October 2007] to a set of 86 organizations distributed over nine economic sectors in South Africa. In total 434 employees were interviewed over three group levels (operational, middle and senior management). This was achieved by having 178 senior practitioners to each interview three subjects (one in each group level).     

A preliminary investigation of special needs students' global and mathematics self-concepts

We investigated students' self-concepts within a multidimensional and hierarchical model. Participants were 95 special needs students in grades 3 through 12 who received mathematics instruction in special education classes. Partial support was found for the hierarchical model in special needs students: The relationship between scores on the Piers-Harris self-Concept Scale and Mathematics Achievement (Iowa Tests of Basic Skills) was significantly stronger for elementary students (r =.53) than for secondary students (r =.04). Percent of the school day spent in special education had a negative relationship (p <.05) to scores on Piers-Harris self-Concept Scale and a positive relationship (p <.05) to an investigator-developed mathematics self-concept instrument. The results suggest that special education has a complex relationship to self-concept. Possible implications for practice and future research are discussed.     

Exploring the challenges in obtaining physical activity data from women using hip-worn accelerometers

Quality objective physical activity data are required to inform physical activity-based health improvement initiatives, however, various challenges undermine acquisition of such data. We examined the efficacy and challenges of a hip-worn accelerometry protocol in women. Specific objectives included determining accelerometer-wear-compliance rates and understanding the barriers and acceptability of wearing accelerometers. Healthy New Zealand women (n?=?406) of three ethnicities (Māori (indigenous New Zealander), Pacific, European) aged 16–45 years (30.9?±?8.7 y) wore hip-mounted Actigraph wGT3X+ accelerometers for 7 consecutive days under a 24-h wear protocol. Post hoc, a sub-sample (n?=?45; age: 29.4?±?9.0 y) was interviewed to investigate comfort/convenience and burdens of accelerometer-wear. Wear-compliance (≥10?h/day, ≥4 day) was 86%. European women returned more valid data (92.7%, p?<?.04) than Pacific (73.0%) or Māori women (82.1%). Twenty-two participants (5.4%) had completely missing data; 13 due to lost accelerometers. Burden of accelerometer-wear was greatest during sleeping (66.7%) due to discomfort. Embarrassment of accelerometer visibility through clothing and consequent restricted clothing choices caused high burden in social settings (45.2%). Discomfort during sleeping, embarrassment due to perceived appearance in social settings and ethnicity are key factors affecting the efficacy of collecting physical activity data from women using hip-worn accelerometers. Refining accelerometer design to reduce size and subsequently participant burden should improve acceptability and wear-compliance. Increasing overall participant compliance by reducing burden and ensuring appropriate understanding of study aims and relevance should reduce attrition and improve wear-compliance and data quality when collecting accelerometry data from women of different ethnicities.     

High-volume resistance training reduces postprandial lipaemia in postmenopausal women

The aim of this study was to compare the effects of 11 weeks of low-volume resistance training (LVRT) and high-volume resistance training (HVRT) on muscle strength, muscle thickness (MT), and postprandial lipaemia (PPL) in postmenopausal women. Thirty-six healthy and untrained postmenopausal women (age, 58.9 ± 5.8 years; 68.6 ± 10.3 kg; and BMI, 26.9 ± 4.8 kg · m^?2) participated in resistance training 3× per week for 11 weeks (HVRT = 12; LVRT = 13; and control group = 11). Biochemical variables, both pretraining and post-training, were evaluated 16 h after the administration of an oral fat tolerance test (OFTT) and metabolic variable during [energy expenditure (EE)] and after training session [excess postexercise oxygen consumption (EPOC)]. Muscle strength (1 RM) and MT were also calculated, and no significant differences were observed between the groups for PPL (mmol · L^?1 per 5 h) as measured by glucose, high-density lipoprotein, low-density lipoprotein, and total cholesterol. EE total (EE + EPOC; 6.12 ± 1.21 MJ vs. 2.26 ± 0.85 MJ), resting fat oxidation (5.52 ± 1.69 g · h^?1 vs. 4.11 ± 1.12 g · h^?1); MT (vastus medialis, 21.4 ± 1.8 mm vs. 18.4 ± 1.2 mm and vastus lateralis 22.3 ± 1.2 mm vs. 20.8 ± 1.3 mm); triacylglycerol (TAG) 0, 1, 2, 4; and 5 h after OFTT, TAG area under the curve (AUC) (5.79 ± 0.42 vs. 7.78 ± 0.68), and incremental AUC (?46.21 ± 14.42% vs. 7.78 ± 4.68%) were all significantly different post-training for HVRT versus LVRT, respectively (P < 0.05). The results of this investigation suggest that HVRT reduces PPL in postmenopausal women.