Critical behavior of confined supramolecular soft materials on a microscopic scale

The formation of fiber networks and the resulting rheological properties of supramolecular soft materials are dramatically influenced when the volume of the system is reduced to a threshold. Unlike un-confined systems, the formation of fiber networks under volume confinement is independent of temperature and solute concentration.

Mechanical behavior of irregular fibers part III : the flexural buckling behavior

Fiber buckling behavior is associated with fabric-evoked prickle, which affects clothing comfort and aesthetics. In this paper, the flexural buckling behavior of irregular or nonuniform fibers is studied using the finite element method (FEM). Fiber dimensional irregularities are simulated with sine waves of different magnitude, frequency, and initial phase. The critical buckling loads of the simulated fibers are then calculated from the FE model. The results indicate that increasing the level of irregularity will decrease the critical buckling load of fibers, but the effect of the frequency and initial phase of irregularity on fiber buckling behavior is complicated and is affected by fiber diameter and effective length.

Behavioral versus demographic predictors of early adoption : a critical analysis and comparative test

Predicting which consumers will be amongst the first to adopt an innovative product is a difficult task but is valuable in allowing effective and efficient use of marketing resources. This paper examines the accuracy of predictions made about likely first adopters based on the most widely accepted theory and compares them to predictions made by examining the relevant past behavior of consumers. A survey of over 1000 consumers examined adoption of an innovative technology: compact fluorescent lightglobes. The results show that variables which were derived from a utility and awareness perspective were a more accurate and managerially useful predictor than the demographic variables derived from the widely accepted theory based on the work of Rogers. It is suggested that these alternative variables could be utilized more readily by marketing managers in many circumstances.

Sport consumer typologies : a critical review

The desire to understand the behavior of sport consumers has been a long-standing goal for sport marketers. This paper critically examines models of sport consumption by undertaking a comparative analysis of the major works completed to the present time. It is suggested that while past works have identified important motivational and behavioral differences, they frequently provide only partial explanations of sport consumer behavior. They are often constrained by an overemphasis on social-psychological traits, and give only limited attention to the cultural and economic context in which behaviors take place. Moreover, they rarely explain how fans might move between different segments, or how relationships with sport teams are formed in the first place. Sport consumer research will be enhanced by a more holistic analysis of values and beliefs that illuminates some of the more shadowy aspects of sport consumer formation, commitment, identity, and game attendance patterns.

The application of the transtheoretical model to offender populations : some critical issues

Purpose : Over the past two decades, the transtheoretical model (TTM) of change has become perhaps the most widely used model of behaviour change in the treatment of addictive and/or problem behaviours. More recently, the stages of change component of the TTM has been adopted for use in forensic settings. This paper aims to review the application of the TTM model to offender populations.

Arguments : The application of the TTM to offenders raises a number of issues regarding the process of behaviour change for offenders attending treatment programmes. It is argued that while the TTM has been designed to account for high frequency behaviour (e.g. smoking, alcohol misuse), offending behaviour may be less frequent and the process of change less cyclical. Moreover, it is suggested that the most important issue in a treatment context is the proper integration of the TTM constructs. There have been few empirical tests of this aspect of the model.

Conclusion : While the TTM may have some value in explaining how rehabilitation programmes help offenders to change their behaviour, the stages of change construct is, by itself, unlikely to adequately explain the process by which offenders desist from offending.

Control over the hydrophobic behavior of polystyrene surface by annealing temperature based on capillary template wetting method

The wetting behavior of water droplets was studied on tunable nanostructured polystyrene (PS) surfaces fabricated by temperature-induced capillary template wetting. The surface morphology of PS varied with the annealing temperature. Contact angle (CA) measurements showed that the wettability of polystyrene surfaces could be tuned from hydrophobic (CA = 104°) to superhydrophobic (CA = 161°) by rendering different morphologies, which could be explained by two distinct wetting modes, i.e., the Wenzel and Cassie–Baxter wetting state. Meanwhile, the critical annealing temperature inducing wetting transition between the Wenzel state and Cassie–Baxter state was obtained. This approach could be easily extended to produce superhydrophobic surfaces on other thermoplastic polymers.

A critical role for the short intracellular C terminus in receptor activity-modifying protein function

Receptor activity-modifying proteins (RAMPs) interact with and modify the behavior of the calcitonin receptor (CTR) and calcitonin receptor-like receptor (CLR). We have examined the contribution of the short intracellular C terminus, using constructs that delete the last eight amino acids of each RAMP. C-Terminal deletion of individual RAMPs had little effect on the signaling profile induced when complexed with CLR in COS-7 or human embryonic kidney (HEK)293 cells. Likewise, confocal microscopy revealed each of the mutant RAMPs translocated hemagglutinin-tagged CLR to the cell surface. In contrast, a pronounced effect of RAMP C-terminal truncation was seen for RAMP/CTRa complexes, studied in COS-7 cells, with significant attenuation of amylin receptor phenotype induction that was stronger for RAMP1 and -2 than RAMP3. The loss of amylin binding upon C-terminal deletion could be partially recovered with overexpression of Gαs, suggesting an impact of the RAMP C terminus on coupling of G proteins to the receptor complex. In HEK293 cells the c-Myc-RAMP1 C-terminal deletion mutant showed high receptor-independent cell surface expression; however, this construct showed low cell surface expression when expressed alone in COS-7 cells, indicating interaction of RAMPs with other cellular components via the C terminus. This mutant also had reduced cell surface expression when coexpressed with CTR. Thus, this study reveals important functionality of the RAMP C-terminal domain and identifies key differences in the role of the RAMP C terminus for CTR versus CLR-based receptors.

Self-assembly behavior of colistin and its prodrug colistin methanesulfonate : implications for solution stability and solubilization

Colistin is an amphiphilic antibiotic that has re-emerged into clinical use due to the increasing prevalence of difficult-to-treat Gram-negative infections. The existence of self-assembling colloids in solutions of colistin and its derivative prodrug, colistin methanesulfonate (CMS), was investigated. Colistin and CMS reduced the air−water interfacial tension, and dynamic light scattering (DLS) studies showed the existence of 2.07 ± 0.3 nm aggregates above 1.5 mM for colistin and of 1.98 ± 0.36 nm aggregates for CMS above 3.5 mM (mean ± SD). Above the respective critical micelle concentrations (CMC) the solubility of azithromycin, a hydrophobic antibiotic, increased approximately linearly with increasing surfactant concentration (5:1 mol ratio colistin:azithromycin), suggestive of hydrophobic domains within the micellar cores. Rapid conversion of CMS to colistin occurred below the CMC (60% over 48 h), while conversion above the CMC was less than 1%. The formation of colistin and CMS micelles demonstrated in this study is the proposed mechanism for solubilization of azithromycin and the concentration-dependent stability of CMS.

A cluster-randomized controlled trial to reduce sedentary behavior and promote physical activity and health of 8-9 year olds : the transform-us! study

Background: Physical activity (PA) is associated with positive cardio-metabolic health and emerging evidence suggests sedentary behavior (SB) may be detrimental to children’s health independent of PA. The primary aim of the Transform-Us! study is to determine whether an 18-month, behavioral and environmental intervention in the school and family settings results in higher levels of PA and lower rates of SB among 8-9 year old children compared with usual practice (post-intervention and 12-months follow-up). The secondary aims are to determine the independent and combined effects of PA and SB on children’s cardio-metabolic health risk factors; identify the factors that mediate the success of the intervention; and determine whether the intervention is cost-effective.
Methods/design: A four-arm cluster-randomized controlled trial (RCT) with a 2 × 2 factorial design, with schools as the unit of randomization. Twenty schools will be allocated to one of four intervention groups, sedentary behavior (SB-I), physical activity (PA-I), combined SB and PA (SB+PA-I) or current practice control (C), which will be evaluated among approximately 600 children aged 8-9 years in school year 3 living in Melbourne, Australia. All children in year 3 at intervention schools in 2010 (8-9 years) will receive the intervention over an 18-month period with a maintenance ‘booster’ delivered in 2012 and children at all schools will be invited to participate in the evaluation assessments. To maximize the sample and to capture new students arriving at intervention and control schools, recruitment will be on-going up to the post-intervention time point. Primary outcomes are time spent sitting and in PA assessed via accelerometers and inclinometers and survey.
Discussion: To our knowledge, Transform-Us! is the first RCT to examine the effectiveness of intervention strategies for reducing children’s overall sedentary time, promoting PA and optimizing health outcomes. The integration of consistent strategies and messages to children from teachers and parents in both school and family settings is a critical component of this study, and if shown to be effective, may have a significant impact on educational policies as well as on pedagogical and parenting practices.

A Response to Critique of the Refreeze Step in Lewin’s Model of Organizational Change from the Viewpoint of Organizational Behavior

Problem Statement
This paper responds to criticism of Kurt Lewin’s three step model of organizational change in increasingly turbulent environments. It explores whether the refreeze step of Kurt Lewin’s notable three step model is still applicable to organizational change processes in the age of globalisation and digitalisation.

Method
Literature review and critical analysis of applied examples are used to provide an overview of Kurt Lewin’s three-step change model. Authors’ observations and reflections are integrated in the discussion. The changing contemporary environment and the implications for the refreeze step of Lewin’s model are accordingly discussed.

Conclusions
The paper concludes that a balance of stability and movement; of discrete and emergent change; is the reality for today’s organizations, and forms the touchstone for Lewin’s formulation of change theories. Alignment is observed between notions of desired equilibrium in Lewin’s model and the contemporary underpinnings of sustainability. Technology and the modern pace of organizational change are also factors to consider. There has hence been an adaptation of his theoretical heritage that is current and sufficiently robust to withstand the criticisms of the refreeze stage.

Preference mining techniques for customer behavior analysis

The thesis has studied a number of critical problems in data mining for customer behavior analysis and has proposed novel techniques for better modeling of the customers’ decision making process, more efficient analysis of their travel behavior, and more effective identification of their emerging preference.

Thermal behavior of copper processed by ECAP with and without back pressure

Samples of electrolytic tough pitch (ETP) pure copper were subjected to 12 passes of Equal-Channel Angular Pressing (ECAP) at room temperature with and without back pressure. Subsequent annealing was performed to evaluate the influence of back pressure during ECAP on the thermal behavior of ultrafine-grained copper. The microstructural and hardness changes caused by annealing were characterized by orientation imaging microscopy (OIM) and microhardness measurements. The application of back pressure resulted in an earlier drop in hardness upon annealing, which is believed to be associated with a lower critical temperature for the initiation of recrystallization and a rapid coarsening of microstructure. Regardless of whether back pressure was applied or not, structure coarsening during short-time annealing of ECAP-processed copper was governed by discontinuous static recrystallization. This is seen as a result of microstructure heterogeneity. Analysis of recrystallization kinetics was carried out based on observations of the microstructure after annealing in terms of the Avrami equation. The magnitude of the apparent activation energies for recrystallization in the absence of back pressure and in the case of back pressure of 100 MPa was estimated to be ~99 kJ/mol and ~91 kJ/mol, respectively. The reasons for reduced activation energy in the case of processing with back pressure are discussed.