Primary and Secondary Variants of Callous-Unemotional Traits in Children with Conduct Problems: A Longitudinal Follow-up During Adolescence

Recent empirical work has suggested that youths with conduct problems and presenting high levels of callous-unemotional (CU) traits can be divided in two variants (i.e., primary, secondary) presenting specific characteristics and needs, but studies examining outcomes associated longitudinally with variants memberships remain scarce. Building on a previous investigation in which we identified variants of CU traits among children with conduct problems, we examined differences between groups on a wide range of behavioral/psychological, relational/social, and educational outcomes assessed during adolescence (n = 309, mean age = 17.4, SD = 0.96). When compared to those from the primary variant, youths from the secondary variant reported higher levels of conduct, opposition, attention deficit/hyperactivity and anxiety problems, had lower teacher-reported academic performance, experienced more conflictual relationships with their teachers, and were at higher risk of being victimized by their intimate partner. These results shed light on the specific clinical characteristics of children from the secondary variant that are likely to persist until adolescence. Providing these children with intensive preventive interventions targeting these long-term consequences could be particularly beneficial.

Associations between externalizing behavior problems and risky sexual behaviors in adolescence: Attachment as a mediator

INTRODUCTION

Risky sexual behaviors in adolescence are associated with negative health and psychological functioning outcomes. Although the association between behavior problems and risky sexual behaviors is well established, addressing these problems requires understanding the mechanisms that help explain this association. Adolescent attachment, while related to risky sexual behavior, has not been extensively explored as an outcome of childhood externalizing problems. The two objectives of this study were to explore the links between parental and peer attachment and risky sexual behaviors and to examine the mediating effect of attachment on the links between behavior problems and risky sexual behaviors.

METHODS

Five hundred and ninety-eight French-Canadian adolescents (46.2% girls), Mage at T1 = 13.23; Mage at T2 = 14.28; Mage at T3 = 17.35) participated in this longitudinal study.

RESULTS

The quality of parental attachment at T2 was significantly and negatively associated with risky sexual behaviors 3 years later, at T3. More specifically, a lower quality parental attachment relationship was associated with having nonexclusive partners as well as with inconsistent condom use. Finally, parental attachment (T2) was a significant mediator between behavior problems (T1) and risky sexual behaviors (T3), but only for younger adolescents.

CONCLUSIONS

Findings suggest that in addition to behavior problems in adolescence, the quality of parental attachment relationships may help in understanding risky sexual behaviors in adolescence.

[An innovative process for sustaining and scaling up a school-based mental health promotion and anxiety prevention programs: The example of the HORS-PISTE program]

Context Anxiety disorders are among the most prevalent psychopathologies for children and adolescents in Quebec. The prevalence of anxiety disorders is very high and has been affecting a growing number of young people for the past 10 years. It is possible to observe an increased number of anxiety prevention programs for young people around the world. However, some authors point out that they are rarely faithfully implemented, sustained, and scaled up in several schools. Based on implementation science, this HORS-PISTE program was developed to address these important issues by preventing anxiety in Quebec high school students. Implemented in more than 100 schools, the program is now part of Action 4.3 (Promote the deployment of the HORS-PISTE program) of the new interdepartmental Action Plan on Mental Health of the Government of Quebec (2022). Purpose This article aims to describe how the Knowledge-to-Action (KTA) framework, derived of implementation science, was used to design, implement, sustain, evaluate, and scale up the HORS-PISTE program. This framework proposes a cyclical process in seven phases. Method A multi-method and multi-stakeholder approach was conducted with a grant from the Public Health Agency of Canada's Mental Health Promotion Innovation Fund, which has been supporting 20 innovative projects across Canada since 2019. It includes a pre-post evaluation protocol consisting of validated questionnaires, surveys (administered to students, parents, and teachers), semi-structured logbooks completed by program facilitators and implementation review meetings in each school. The different cycles of the program development, implementation and evaluation are discussed through the KTA framework phases. Results From 2017 to 2021, this methodology made it possible to evaluate and readjust the program each year to promote its adaptation and prepare its scaling up. This article highlights the data collected and analyzed in relation to the seven phases of the KTA framework. Conclusion This article demonstrates how implementation science can support designers of anxiety prevention programs who are concerned by scaling up and sustaining their programs. Issues in combining the scientific rigor of evaluation with the reality of the field are also raised.

Density graded polyethylene foams: Effect of processing conditions on mechanical properties

Uniform foams (UF) and density graded foams (DGF) were produced by using similar or different temperatures on both sides of a compression molding system. The samples were produced using linear low density polyethylene as the matrix and activated azodicarbonamide as the chemical blowing agent. Morphological properties of the produced samples were analyzed via scanning electron microscopy to relate them to their mechanical properties. In particular, flexural and impact properties are reported for samples produced under a range of temperatures (140–200°C) and blowing agent concentration (0.7–1.0 wt%). The experimental results showed that a significant difference can be obtained in flexural modulus (up to 17%) and impact strength (up to 48%) depending on the side the stress is applied on. In all cases, the DGF showed better mechanical responses than UF of similar relative density for the range of conditions tested.

Click chemistry stereolithography for soft robots that self-heal

Although soft robotics promises a new generation of robust, versatile machines capable of complex functions and seamless integration with biology, the fabrication of such soft, three dimensional (3D) hierarchical structures remains a significant challenge. Stereolithography (SLA) is an additive manufacturing technique that can rapidly fabricate the complex device architectures required for the next generation of these systems. Current SLA materials and processes are prohibitively expensive, display little elastic deformation at room temperature, or exhibit Young's moduli exceeding most natural tissues, all of which limit use in soft robotics. Herein, we report a low-cost build window substrate that enables the rapid fabrication of high resolution (∼50 μm) silicone (polydimethylsiloxane) based elastomeric devices using an open source SLA printer. Our thiol-ene click chemistry permits photopolymerization using low energy (H_e < 20 mJ cm^-2) optical wavelengths (405 nm < λ < 1 mm) available on many low-cost SLA machines. This chemistry is easily tuned to achieve storage moduli, 6 < E < 283 kPa at engineering strains, γ = 0.02; similarly, a large range of ultimate strains, 0.5 < γ_ult < 4 is achievable through appropriate selection of the two primary chemical constituents (mercaptosiloxane, M.S., and vinylsiloxane, V.S.). Using this chemo-mechanical system, we directly fabricated compliant machines, including an antagonistic pair of fluidic elastomer actuators (a primary component in most soft robots). During printing, we retained unreacted pockets of M.S. and V.S. that permit autonomic self-healing, via sunlight, upon puncture of the elastomeric membranes of the soft actuators.

Three-dimensional printing of freeform helical microstructures: a review

Three-dimensional (3D) printing is a fabrication method that enables creation of structures from digital models. Among the different structures fabricated by 3D printing methods, helical microstructures attracted the attention of the researchers due to their potential in different fields such as MEMS, lab-on-a-chip systems, microelectronics and telecommunications. Here we review different types of 3D printing methods capable of fabricating 3D freeform helical microstructures. The techniques including two more common microfabrication methods (i.e., focused ion beam chemical vapour deposition and microstereolithography) and also five methods based on computer-controlled robotic direct deposition of ink filament (i.e., fused deposition modeling, meniscus-confined electrodeposition, conformal printing on a rotating mandrel, UV-assisted and solvent-cast 3D printings) and their advantages and disadvantages regarding their utilization for the fabrication of helical microstructures are discussed. Focused ion beam chemical vapour deposition and microstereolithography techniques enable the fabrication of very precise shapes with a resolution down to ∼100 nm. However, these techniques may have material constraints (e.g., low viscosity) and/or may need special process conditions (e.g., vacuum chamber) and expensive equipment. The five other techniques based on robotic extrusion of materials through a nozzle are relatively cost-effective, however show lower resolution and less precise features. The popular fused deposition modeling method offers a wide variety of printable materials but the helical microstructures manufactured featured a less precise geometry compared to the other printing methods discussed in this review. The UV-assisted and the solvent-cast 3D printing methods both demonstrated high performance for the printing of 3D freeform structures such as the helix shape. However, the compatible materials used in these methods were limited to UV-curable polymers and polylactic acid (PLA), respectively. Meniscus-confined electrodeposition is a flexible, low cost technique that is capable of fabricating 3D structures both in nano- and microscales including freeform helical microstructures (down to few microns) under room conditions using metals. However, the metals suitable for this technique are limited to those that can be electrochemically deposited with the use of an electrolyte solution. The highest precision on the helix geometry was achieved using the conformal printing on a rotating mandrel. This method offers the lowest shape deformation after printing but requires more tools (e.g., mandrel, motor) and the printed structure must be separated from the mandrel. Helical microstructures made of multifunctional materials (e.g., carbon nanotube nanocomposites, metallic coated polymer template) were used in different technological applications such as strain/load sensors, cell separators and micro-antennas. These innovative 3D microsystems exploiting the unique helix shape demonstrated their potential for better performance and more compact microsystems.

Electrical transport properties of single wall carbon nanotube/polyurethane composite based field effect transistors fabricated by UV-assisted direct-writing technology

We report on the fabrication and transport properties of single-walled carbon nanotube (SWCNT)/polyurethane (PU) nanocomposite microfiber-based field effect transistors (FETs). UV-assisted direct-writing technology was used, and microfibers consisting of cylindrical micro-rods, having different diameters and various SWCNT loads, were fabricated directly onto SiO₂/Si substrates in a FET scheme. The room temperature dc electrical conductivities of these microfibers were shown to increase with respect to the SWCNT concentrations in the nanocomposite, and were about ten orders of magnitude higher than that of the pure polyurethane, when the SWCNT load ranged from 0.1 to 2.5 wt% only. Our results show that for SWCNT loads ≤ 1.5 wt%, all the microfibers behave as a FET with p-type transport. The resulting FET exhibited excellent performance, with an I(on)/I(off) ratio of 10⁵ and a maximum on-state current (I(on)) exceeding 70 µA. Correlations between the FET performance, SWCNTs concentration, and the microfiber diameters are also discussed.