Deviant behavior variety scale: Development and validation with a sample of portuguese adolescents

This study presents the development and analysis of the psychometric properties of the Deviant Behavior Variety Scale (DBVS). Participants were 861 Portuguese adolescents (54 % female), aged between 12 and 19 years old. Two alternative models were tested using Confirmatory Factor Analysis. Although both models showed good fit indexes, the two-factor model didn’t presented discriminant validity. Further results provided evidence for the factorial and the convergent validity of the single-factor structure of the DVBS, which has also shown good internal consistency. Criterion validity was evaluated through the association with related variables, such as age and school failure, as well as the scale’s ability to capture group differences, namely between genders and school retentions, and finally by comparing a sub-group of convicted adolescents with a group of non-convicted ones regarding their engagement in delinquent activities. Overall, the scale presented good psychometric properties, with results supporting that the DBVS is a valid and reliable self-reported measure to evaluate adolescents’ involvement in deviance.

Intrusion Detection Systems in SDN-based Self-Healing PMU Networks

Nowadays, Power grids are critical infrastructures on which everything else relies, and their correct behavior is of the highest priority. New smart devices are being deployed to be able to manage and control power grids more efficiently and avoid instability. However, the deployment of such smart devices like Phasor Measurement Units (PMU) and Phasor Data Concentrators (PDC), open new opportunities for cyber attackers to exploit network vulnerabilities. If a PDC is compromised, all data coming from PMUs to that PDC is lost, reducing network observability. Our approach to solve this problem is to develop an Intrusion detection System (IDS) in a Software-defined network (SDN). allowing the IDS system to detect compromised devices and use that information as an input for a self-healing SDN controller, which redirects the data of the PMUs to a new, uncompromised PDC, maintaining the maximum possible network observability at every moment. During this research, we have successfully implemented Self-healing in an example network with an SDN controller based on Ryu controller. We have also assessed intrinsic vulnerabilities of Wide Area Management Systems (WAMS) and SCADA networks, and developed some rules for the Intrusion Detection system which specifically protect vulnerabilities of these networks. The integration of the IDS and the SDN controller was also successful. \\To achieve this goal, the first steps will be to implement an existing Self-healing SDN controller and assess intrinsic vulnerabilities of Wide Area Measurement Systems (WAMS) and SCADA networks. After that, we will integrate the Ryu controller with Snort, and create the Snort rules that are specific for SCADA or WAMS systems and protocols.

Cognitive control as a moderator of temperamental motivations toward adolescent risk-taking behavior

Few studies have directly examined whether cognitive control can moderate the influence of temperamental positive and negative affective traits on adolescent risk-taking behavior. Using a combined multimethod, latent variable approach to the assessment of adolescent risk-taking behavior and cognitive control, this study examined whether cognitive control moderates the influence of temperamental surgency and frustration on risk-taking behavior in a sample of 177 adolescents (Mage = 16.12 years, SD = 0.69). As predicted, there was a significant interaction between cognitive control and frustration, but not between cognitive control and surgency, in predicting risk-taking behavior. These findings have important implications and suggest that the determinants of adolescent risk taking depend on the valence of the affective motivation for risk-taking behavior.

Measuring the accuracy of self-reported height and weight in a community-based sample of young people

BACKGROUND: Self-reported anthropometric data are commonly used to estimate prevalence of obesity in population and community-based studies. We aim to: 1) Determine whether survey participants are able and willing to self-report height and weight; 2) Assess the accuracy of self-reported compared to measured anthropometric data in a community-based sample of young people.

METHODS: Participants (16-29 years) of a behaviour survey, recruited at a Melbourne music festival (January 2011), were asked to self-report height and weight; researchers independently weighed and measured a sub-sample. Body Mass Index was calculated and overweight/obesity classified as ≥25 kg/m². Differences between measured and self-reported values were assessed using paired t-test/Wilcoxon signed ranks test. Accurate report of height and weight were defined as <2 cm and <2 kg difference between self-report and measured values, respectively. Agreement between classification of overweight/obesity by self-report and measured values was assessed using McNemar's test.

RESULTS: Of 1405 survey participants, 82% of males and 72% of females self-reported their height and weight. Among 67 participants who were also independently measured, self-reported height and weight were significantly less than measured height (p=0.01) and weight (p<0.01) among females, but no differences were detected among males. Overall, 52% accurately self-reported height, 30% under-reported, and 18% over-reported; 34% accurately self-reported weight, 52% under-reported and 13% over-reported. More females (70%) than males (35%) under-reported weight (p=0.01). Prevalence of overweight/obesity was 33% based on self-report data and 39% based on measured data (p=0.16).

CONCLUSIONS: Self-reported measurements may underestimate weight but accurately identified overweight/obesity in the majority of this sample of young people.

Text message and internet support for coronary heart disease self-management: results from the text4heart randomized controlled trial

BACKGROUND: Mobile technology has the potential to deliver behavior change interventions (mHealth) to reduce coronary heart disease (CHD) at modest cost. Previous studies have focused on single behaviors; however, cardiac rehabilitation (CR), a component of CHD self-management, needs to address multiple risk factors. OBJECTIVE: The aim was to investigate the effectiveness of a mHealth-delivered comprehensive CR program (Text4Heart) to improve adherence to recommended lifestyle behaviors (smoking cessation, physical activity, healthy diet, and nonharmful alcohol use) in addition to usual care (traditional CR). METHODS: A 2-arm, parallel, randomized controlled trial was conducted in New Zealand adults diagnosed with CHD. Participants were recruited in-hospital and were encouraged to attend center-based CR (usual care control). In addition, the intervention group received a personalized 24-week mHealth program, framed in social cognitive theory, sent by fully automated daily short message service (SMS) text messages and a supporting website. The primary outcome was adherence to healthy lifestyle behaviors measured using a self-reported composite health behavior score (≥3) at 3 and 6 months. Secondary outcomes included clinical outcomes, medication adherence score, self-efficacy, illness perceptions, and anxiety and/or depression at 6 months. Baseline and 6-month follow-up assessments (unblinded) were conducted in person. RESULTS: Eligible patients (N=123) recruited from 2 large metropolitan hospitals were randomized to the intervention (n=61) or the control (n=62) group. Participants were predominantly male (100/123, 81.3%), New Zealand European (73/123, 59.3%), with a mean age of 59.5 (SD 11.1) years. A significant treatment effect in favor of the intervention was observed for the primary outcome at 3 months (AOR 2.55, 95% CI 1.12-5.84; P=.03), but not at 6 months (AOR 1.93, 95% CI 0.83-4.53; P=.13). The intervention group reported significantly greater medication adherence score (mean difference: 0.58, 95% CI 0.19-0.97; P=.004). The majority of intervention participants reported reading all their text messages (52/61, 85%). The number of visits to the website per person ranged from zero to 100 (median 3) over the 6-month intervention period. CONCLUSIONS: A mHealth CR intervention plus usual care showed a positive effect on adherence to multiple lifestyle behavior changes at 3 months in New Zealand adults with CHD compared to usual care alone. The effect was not sustained to the end of the 6-month intervention. A larger study is needed to determine the size of the effect in the longer term and whether the change in behavior reduces adverse cardiovascular events. TRIAL REGISTRATION: ACTRN 12613000901707; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364758&isReview=true (Archived by WebCite at http://www.webcitation.org/6c4qhcHKt).

Improving coronary heart disease self-management using mobile technologies (Text4Heart): a randomised controlled trial protocol

BACKGROUND: Cardiac rehabilitation (CR) is a secondary prevention program that offers education and support to assist patients with coronary heart disease (CHD) make lifestyle changes. Despite the benefits of CR, attendance at centre-based sessions remains low. Mobile technology (mHealth) has potential to reach more patients by delivering CR directly to mobile phones, thus providing an alternative to centre-based CR. The aim of this trial is to evaluate if a mHealth comprehensive CR program can improve adherence to healthy lifestyle behaviours (for example, physically active, fruit and vegetable intake, not smoking, low alcohol consumption) over and above usual CR services in New Zealand adults diagnosed with CHD.

METHODS/DESIGN: A two-arm, parallel, randomised controlled trial will be conducted at two Auckland hospitals in New Zealand. One hundred twenty participants will be randomised to receive a 24-week evidence- and theory-based personalised text message program and access to a supporting website in addition to usual CR care or usual CR care alone (control). The primary outcome is the proportion of participants adhering to healthy behaviours at 6 months, measured using a composite health behaviour score. Secondary outcomes include overall cardiovascular disease risk, body composition, illness perceptions, self-efficacy, hospital anxiety/depression and medication adherence.

DISCUSSION: This study is one of the first to examine an mHealth-delivered comprehensive CR program. Strengths of the trial include quality research design and in-depth description of the intervention to aid replication. If effective, the trial has potential to augment standard CR practices and to be used as a model for other disease prevention or self-management programs.

The HEART mobile phone trial: the partial mediating effects of self-efficacy on physical activity among cardiac patients

BACKGROUND: The ubiquitous use of mobile phones provides an ideal opportunity to deliver interventions to increase physical activity levels. Understanding potential mediators of such interventions is needed to increase their effectiveness. A recent randomized controlled trial of a mobile phone and Internet (mHealth) intervention was conducted in New Zealand to determine the effectiveness on exercise capacity and physical activity levels in addition to current cardiac rehabilitation (CR) services for people (n = 171) with ischemic heart disease. Significant intervention effect was observed for self-reported leisure-time physical activity and walking, but not peak oxygen uptake at 24 weeks. There was also significant improvement in self-efficacy.

OBJECTIVE: To evaluate the mediating effect of self-efficacy on physical activity levels in an mHealth delivered exercise CR program.

METHODS: Treatment evaluations were performed on the principle of intention to treat. Adjusted regression analyses were conducted to evaluate the main treatment effect on leisure-time physical activity and walking at 24 weeks, with and without change in self-efficacy as the mediator of interest.

RESULTS: Change in self-efficacy at 24 weeks significantly mediated the treatment effect on leisure-time physical activity by 13%, but only partially mediated the effect on walking by 4% at 24 weeks.

CONCLUSION: An mHealth intervention involving text messaging and Internet support had a positive treatment effect on leisure-time physical activity and walking at 24 weeks, and this effect was likely mediated through changes in self-efficacy. Future trials should examine other potential mediators related to this type of intervention.

Self-report use-of-time tools for the assessment of physical activity and sedentary behaviour in young people: systematic review

UNLABELLED: Regular physical activity and limiting extended periods of sitting are two behaviours critical for the prevention of obesity in young people. The purpose of the systematic review was to synthesize the psychometric evidence for self-report use-of-time tools that assess these behaviours. Articles were retrieved that reported reliability and/or validity for use-of-time tools in participants aged 18 years or under. Outcome variables were physical activity, sedentary behaviour and energy expenditure. Study quality was appraised, and the results summarized narratively. Sixteen studies and six different tools were identified. The tools were the Previous Day Physical Activity Recall, the Three-Day Physical Activity Recall, the Physical Activity Interview, the Computerized Activity Recall, the Activitygram, and the Multimedia Activity Recall for Children and Adolescents. Overall, tools indicated moderate validity compared with objective and criterion comparison methods. Generally, validity correlation coefficients were in the range of 0.30-0.40. Correlation coefficients for test-retest reliability ranged widely from 0.24 to 0.98. CONCLUSION: Use-of-time tools have indicated moderate reliability and validity for the assessment of physical activity and energy expenditure. Future research should focus on using criterion methods and on validating specifically for sedentary behaviour outcomes. Implementation of these tools for population surveillance should be considered.

Predicting physical activity intention and behavior in school-age children

Two studies were conducted to predict physical activity in school-aged children. Study 1 tested the utility of an integrated model in predicting physical activity (PA) intention and behavior-the theory of planned behavior (TPB) and self-efficacy theory. Six hundred and forty-five New Zealand children (aged 11-13 years) completed measures corresponding to the integrated model and a self-reported measure of PA one week later. Perceived behavioral control (PBC) and subjective norm were the two strongest predictors of intentions. Task efficacy and barrier efficacy were the two strongest predictors of PA. A second study (Study 2) was conducted to determine whether the self-efficacy measures could discriminate objectively measured PA levels. Sixty-seven Canadian children (aged 11-13 years) completed task and barrier self-efficacy measures. The following week, children classified as 'high' (n = 11) and 'lower' (n = 7) for both task and barrier efficacy wore an Actical® monitor for seven consecutive days to provide activity-related energy expenditure (AEE) data. Results showed that children with high efficacy expended significantly greater AEE than their lower efficacious counterparts. Findings from these two studies provide support for the use of self-efficacy interventions as a potentially useful means of increasing PA levels among school-aged children.

Are adolescents with high self-esteem protected from psychosomatic symptomatology?

This study investigated the role of self-esteem, social (need to belong, loneliness, competitiveness, and shyness), and health (smoking, drinking) behaviors in Hungarian adolescents' psychosomatic symptoms. Our sample of 490 students (ages 14-19 years) from Debrecen (Hungary) completed the questionnaires. Besides descriptive statistics, correlation and multiple regression analyses were applied to test interrelationships. Frequency analysis revealed that fatigue was the most commonly experienced psychosomatic symptom in this sample, followed by sleeping problems and (lower) back pain. Girls reported experiencing more symptoms. Multiple regression analyses suggested that (1) need to belong, shyness, and competitiveness may serve as social behavioral risk factors for adolescents' psychosomatic symptomatology, whereas (2) self-esteem may play a protective role. The role of social and health behaviors was modified when analyzed by gender: the psychosomatic index score was positively related to smoking and shyness among girls, and need to belong among boys. Self-esteem provided protection for both sexes. CONCLUSION: We conclude that problems with social relationships (namely, unmet need to belong, competitiveness, and shyness) may lead to psychosomatic health complaints, whereas self-esteem may serve as a protection. Findings suggest that social skills training and strengthening self-esteem should be an important part of children's health promotion programs in schools to improve their psychosomatic health and well-being.

Hydrogen bonding interactions in poly(ε-caprolactone-dimethyl siloxane-ε-caprolactone)/poly(hydroxyether of bisphenol A) triblock copolymer/homopolymer blends and the effect on crystallization, microphase separation and self-assembly

This study investigated the self-assembled microphase separated morphologies that are obtained in bulk, by the complexation of a semicrystalline poly(ε-caprolactone-dimethyl siloxane-ε-caprolactone) (PCL-PDMS-PCL) triblock copolymer and a homopolymer, poly(hydroxyether of bisphenol A) (PH) in tetrahydrofuran (THF). In these blends, microphase separation takes place due to the disparity in intermolecular interactions; specifically, the homopolymer interacts with PCL blocks through hydrogen bonding interactions. The crystallization, microphase separation and crystalline structures of a triblock copolymer/homopolymer blends were investigated. The phase behavior of the complexes was investigated using small-angle X-ray scattering and transmission electron microscopy. At low PH concentrations, PCL interacts relatively weakly with PH, whereas in complexes containing more than 50 wt% PH, the PCL block interacts significantly with PH, leading to the formation of composition-dependent nanostructures. SAXS and TEM results indicate that the lamellar morphology of neat PCL-PDMS-PCL triblock copolymer changes into disordered structures at 40-60 wt% PH. Spherical microdomains were obtained in the order of 40-50 nm in complexes with 80 wt% PH. At this concentration, the complexes show a completely homogenous phase of PH/PCL, with phase-separated spherical PDMS domains. The formation of these nanostructures and changes in morphology depends on the strength of hydrogen bonding between PH/PCL blocks and also the phase separated PDMS blocks.

Enhancement of ‘dry’ proton conductivity by self-assembled nanochannels in all-solid polyelectrolytes

Proton transport has been recognized as an essential process in many biological systems, as well as electrochemical devices including fuel cells and redox flow batteries. In the present study, we address the pressing need for solvent-free proton conducting polymer electrolytes for high-temperature PEM fuel cell applications by developing a novel all-solid polyelectrolyte membrane with a self-assembled proton-channel structure. We show that this self-assembled nanostructure endows the material with exciting ‘dry’ proton conductivity at elevated temperatures, as high as 0.3 mS cm−1 at 120 °C, making it an attractive candidate for high-temperature PEM fuel cell applications. Based on the combined investigation of solid-state NMR, FTIR and conductivity measurements, we propose that both molecular design and nano-scale structures are essential for obtaining highly conductive anhydrous proton conductors.

A facile method to fabricate carbon nanostructures via the self-assembly of polyacrylonitrile/poly (methyl methacrylate-b-polyacrylonitrile) AB/B' type block copolymer/homopolymer blends

The self-assembly and high temperature behavior of AB/B′ type block copolymer/homopolymer blends containing polyacrylonitrile (PAN) polymers were studied for the first time. Here, microphase separated nanostructures were formed in the poly(methyl methacrylate-b-polyacrylonitrile) (PMMAN) block copolymer and their blends with homopolymer PAN at various blend ratios. Additionally, these nanostructures were transformed into porous carbon nanostructures by sacrificing PMMA blocks via pyrolysis. Spherical and worm like morphologies were observed in both TEM and AFM images at different compositions. The thermal and phase behavior examinations showed good compatibility between the blend components in all studied compositions. The PAN homopolymer (B′) with a comparatively higher molecular weight than the corresponding block (B) of the block copolymer is expected to exhibit ‘dry brush’ behavior in this AB/B′ type system. This study provides a basic understanding of the miscibility and phase separation in the PMMAN/PAN system, which is important in the nanostructure formation of bulk PAN based materials with the help of block copolymers to develop advanced functional materials.

Synthesis and self-assembly behaviour of poly(Nα-Boc-l-tryptophan)-block-poly(ethylene glycol)-block-poly(Nα-Boc-l-tryptophan)

We report for the first time the use of Nα-Boc-l-tryptophan for the synthesis of amphiphilic BAB triblock copolymers for potential drug delivery applications. A library of poly(Nα-Boc-l-tryptophan)-block-poly(ethylene glycol)-block-poly(Nα-Boc-l-tryptophan) (PBoclTrp-b-PEG-b-PBoclTrp) amphiphilic copolymers were synthesized through the ring opening polymerization of Nα-Boc-l-tryptophan Nα-carboxy anhydride as initiated by diamino-terminated PEG of fixed molecular weight (Mn 3350). The influence of the hydrophobic block length over self-assembly was investigated for 4 of the BAB copolymers of molecular weights varying between Mn 5000 and Mn 17000. It was found that an increase in hydrophobic block length led to an increase in hydrodynamic size of aggregates in solution, as well as a decrease in critical micelle concentration. TEM analysis showed the formation of spherical micelles with the largest of the copolymers forming interconnected networks of spherical micelles. The influence of hydrophobic block length over the formation of secondary structure was analyzed using circular dichroism and infrared spectroscopy. Collectively we found that the presence of t-Boc protected l-tryptophan leads to the preferential formation of α-helix secondary structure through hydrogen bonding, which, in a drug delivery vehicle context, could help in controlling drug release. Also, it is believed that the use of novel Nα-Boc-l-tryptophan could improve drug stabilization in the hydrophobic core via π-π interactions between indole rings.

Correlates of agreement between accelerometry and self-reported physical activity

PURPOSE: Understanding factors that influence accurate assessment of physical activity (PA) and sedentary behavior (SB) is important to measurement development, epidemiologic studies, and interventions. This study examined agreement between self-reported (International Physical Activity Questionnaire-Long Form [IPAQ-LF]) and accelerometry-based estimates of PA and SB across six countries and identified correlates of between-method agreement. METHODS: Self-report and objective (accelerometry-based) PA and SB data were collected in 2002-2011 from 3865 adult participants in eight cities from six countries (Belgium, Czech Republic, Denmark, Spain, United Kingdom, and United States). Between-method relative agreement (correlation) and absolute disagreement (mean difference between conceptually and intensity-matched IPAQ-LF and accelerometry-based PA and SB variables) were estimated. Also, sociodemographic characteristics and PA patterns were examined as correlates of between-method agreement. RESULTS: Observed relative agreement (relationships of IPAQ-LF with accelerometry-based PA and SB variables) was small to moderate (r = 0.05-0.37) and was moderated by sociodemographic (age, sex, weight status, and education) and behavioral (PA-type) factors. The absolute disagreement was large, with participants self-reporting higher PA intensity and total time in moderate-to-vigorous-intensity PA than accelerometry. Also, self-reported sitting time was lower than accelerometry-based sedentary behavior. After adjusting for sociodemographic and behavioral factors, the absolute disagreement between pairs of IPAQ-LF and accelerometry-based PA variables remained significantly different across cities/countries. CONCLUSIONS: Present findings suggest systematic cultural and/or linguistic and sociodemographic differences in absolute agreement between the IPAQ-LF and the accelerometry-based PA and SB variables. These results have implications for the interpretation of international PA and SB data and correlate/determinant studies. They call for further efforts to improve such measures.