Changes In Mechanical Behavior Research Articles

The Recyclability of Fire-Retarded Biobased Polyamide 11 (PA11) Composites Reinforced with Basalt Fibers (BFs): The Influence of Reprocessing on Structure, Properties, and Fire Behavior.

The growing requirements regarding the safety of using polymers and their composites are related to the emergence of more effective, sustainable, and hazardous-limited fire retardants (FRs). Significant amounts of FRs are usually required to effectively affect a polymer's burning behavior, while the knowledge of their recycling potential is still insufficient. At the same time, concerns are related not only to the reduced effectiveness of flame retardancy but also, above all, to the potential deterioration of mechanical properties caused by the degradation of temperature-affected additives under processing conditions. This study describes the impact of the four-time reprocessing of bio-based polyamide 11 (PA11) modified with an intumescent flame-retardant (IFR) system composed of ammonium polyphosphate (APP), melamine cyanurate (MC), and pentaerythritol (PER) and its composites containing additional short basalt fibers (BFs). Composites manufactured via twin-screw extrusion were subjected to four reprocessing cycles using injection molding. A comprehensive analysis of their structural, mechanical, and fire behavior changes in each cycle was conducted. The obtained results confirmed the safety of using the proposed fire-retarded polyamide and its composites while reprocessing under the recommended process parameters without the risk of significant changes in the structure. The partial increase in flammability of reprocessed PA-based materials caused mainly by polymer degradation has been described.

Efficacy of polygenic risk scores and digital technologies for INNOvative personalized cardiovascular disease PREVention in high-risk adults: protocol of a randomized controlled trial

Efficacy of polygenic risk scores and digital technologies for INNOvative personalized cardiovascular disease PREVention in high-risk adults: protocol of a randomized controlled trial

Comprehending Health Behavior Change and Maintenance: A Systematic Review and Meta-Synthesis of Behavior Theories

ABSTRACT Background Health behaviors exhibit diverse characteristics and types, leading to health behavior theories with varied focuses. However, an integrated framework elucidating the intrinsic mechanisms of different behavior types is notably absent. Purpose This study aimed to establish such a framework offering a comprehensive basis for explanations and behavior interventions. Methods A systematic review and meta-synthesis of qualitative research concerning health behavior change and maintenance were conducted. Results A total of 556 records were identified and screened, with 170 meeting the inclusion criteria. Thematic synthesis, a form of meta-synthesis, generated 23 themes, with the qualitative relationships between them presented in a conceptual model, forming an integrated framework. Discussion This framework provides a dynamic and hierarchical platform that enables the interpretation and analysis of various health behaviors within a unified structure. Furthermore, the recognition of the dynamicity of constructs and the multiplicity of behavior routes offers certain implications for intervention design, including behavior setting guidance, immediate benefits provision, and behavior interactions utilization. Translation to Health Education Practice The study provides an integrated framework for health educators/promoters. It offers a comprehensive view of health behavior change mechanisms from multiple perspectives and provides insights for the design, implementation and evaluation of behavior intervention practices.

Mechanisms of Behavior Change for Functional Improvements in Cannabis Use Disorder Treatments: Current Science and Future Outlook

Mechanisms of Behavior Change for Functional Improvements in Cannabis Use Disorder Treatments: Current Science and Future Outlook

Evaluating and Enhancing an Educational Intervention to Reduce Smallholder Farmers' Exposure to Pesticides in Uganda Through a Digital, Systematic Approach to Behavior Change: Protocol for a Cluster-Randomized Controlled Trial.

Smallholder farmers receive educational interventions on safe pesticide handling by governmental agencies, industries, or nongovernmental organizations to reduce exposure risks. However, existing educational interventions have limited effects on changing behaviors. Targeting psychosocial determinants of behavior change in educational interventions through theory- and evidence-based approaches may enhance their effectiveness. We aim at describing the intervention development and study design of a 3-arm cluster-randomized controlled trial to assess the effects in improving safe pesticide handling and reducing pesticide exposure of (1) an existing educational intervention and (2) a newly developed SMS text messaging intervention based on the Risks, Attitudes, Norms, Abilities, and Self-regulation (RANAS) behavior change approach. We enrolled 539 Ugandan smallholder farmers in 12 clusters (subcounties). The clusters, each with 45 farmers, were randomly allocated to one of the three arms: (1) educational intervention, (2) educational intervention+RANAS-based SMS text messages, or (3) control group. The educational intervention comprised a 2-day workshop that targeted multiple aspects of safe pesticide handling, whereas the SMS text messages targeted the use of personal protective equipment (PPE) and were based on the RANAS approach. For intervention development in this study, this approach includes identifying psychosocial determinants of PPE use at baseline and selecting behavior change techniques to target them in SMS text messages. The primary outcomes of the study are (1) pesticide knowledge, attitude, and practice scores indicating performance throughout the educational intervention; and (2) frequency of PPE use. Secondary outcomes are the RANAS-based behavioral determinants of PPE use, the frequency of glove use, algorithm-based pesticide exposure intensity scores, and signs and symptoms of pesticide poisoning. The outcomes were assessed in structured interviews before the intervention (baseline) and at the 12-month follow-up. The effect of the interventions among the arms will be analyzed using the intervention arms and baseline measures as predictors and the follow-up measures as outcomes in linear multivariable mixed models including the clusters as random effects. The mediating psychosocial determinants of the interventions will be assessed in multiple mediation models. The study was conducted from 2020 to 2021-baseline interviews were conducted in October 2020, and the educational intervention was delivered in November 2020. The RANAS-based SMS text messages were developed based on the baseline data for relevant behavioral determinants of PPE use and sent between February 2021 and September 2021. Follow-up interviews were conducted in October 2021. Overall, 539 farmers were enrolled in the study at baseline; 8.3% (45/539) were lost to follow-up by the end of the study. This study will contribute to a better understanding of the effectiveness and behavior change mechanisms of educational interventions by using an experimental, cluster-randomized study design to improve pesticide handling among smallholder farmers. International Standard Randomised Controlled Trial Number (ISRCTN) 18237656; https://doi.org/10.1186/ISRCTN18237656. DERR1-10.2196/55238.

Selective Timing of Maternal Immune Activation Alters Developmental Milestones, Behavior, and Blood-Brain Barrier Integrity

Background and Hypothesis: Maternal immune activation (MIA) has been associated with increased risk for neuropsychiatric disease. Fetal exposure to maternal infection activates different toll-like receptors (TLRs) to initiate innate inflammatory responses in mother and fetus. The goal of the current study is to determine sex-dependent aspects of MIA during mid-gestation on neurodevelopment. Methods: Timed-pregnant female mice were administered RQ (TLR7 agonist) or vehicle saline on embryonic day (E) 12.5. Maternal and fetal cytokines were measured to ensure infection of pregnant dam (E15). Offspring were assessed postnatally for developmental milestones and behavior. Adult offspring were perfused with fluorescein isothiocyanate (FITC; 100mg/mL) to visualize blood vessel integrity (FITC leakage; Frahm & Tobet, 2015). To determine neural molecular mechanisms for behavioral changes, sections through the paraventricular nucleus of the hypothalamus (PVN) of offspring were immunolabeled for Glial Fibrillary Acidic Protein (GFAP; astrocytic end feet), Desmin (pericytes) and IBA-1 (microglia). Results: Maternal cytokines IL-6 (p<0.05) and IL-10 (p<0.01) were higher while TNFα (p<0.01) and IL-17 were lower 3 days after RQ-exposure. In fetuses (E15), IL-6 (p<0.05) and IL-17 (p<0.0001) were greater, while IL-10 was higher only in males (p<0.001) exposed to maternal infection. RQ-exposed males also had reduced TNFα (p<0.05). Additionally, RQ-exposed offspring had lower body weights at birth and delayed eye openings. Females exposed to maternal RQ exhibited slower onset of puberty with delayed vaginal openings. On the behavioral side, juvenile and adult offspring of RQ injected moms exhibited less social-like behavior (p<0.001 for all groups) with lower hedonic-like behavior selectively in females (p<0.001). RQ-offspring further showed greater leakage in the PVN indicated by more FITC in the extravascular space (males p<0.001, females p<0.01). GFAP + (astrocytic end feet) coverage of FITC-labeled vessels was higher in the PVN selectively in RQ males (p<0.001). Desmin+ (pericyte) coverage was greater in the PVN of RQ males (p<0.01) and females (p<0.001). Finally, there was greater number of IBA-1+ cells in the adult offspring PVN of both sexes (p<0.01) after maternal injection of RQ. Conclusions: This study provides support for sex-dependent influences of fetal antecedents for altered brain development and behavioral outputs that could be indicative of increased susceptibility for adult disorders through immune mechanisms. Future studies will examine how timing of infection during gestation (mid vs. late) changes neurodevelopmental outputs in offspring. Supported by ORWH-NIMH U54 SCORE-MH118919. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A Systematic Review and Narrative Synthesis of Single-Case Group Contingency Interventions Targeting Prosocial and Antisocial Behavior in School Children

Group contingencies are well established as methods for reducing disruptive classroom behaviors and increasing academic behaviors. However, their role in increasing prosocial behaviors has not yet been explored to the same extent. We conducted a systematic review of the single-case literature to synthesize the types of prosocial and antisocial behaviors targeted in school settings, the short-term and long-term behavioral contingencies used to target these behaviors, and the quality of the literature. We searched five databases for studies exploring the use of group contingencies to increase prosocial behaviors or decrease antisocial behaviors in children. Our narrative synthesis of the twenty-two included studies noted contingencies employed in these interventions consisted of either positive reinforcement or a combination of positive reinforcement and positive punishment. Of the 22 studies included for review, none met the What Works Clearinghouse Design Standards without reservations. Interobserver agreement and demonstration of effects over time were the most commonly unmet design standards. Future research should seek to encourage greater focus on both prosocial behavior and positive behavior change mechanisms. PROSPERO ID: CRD42022337025.

Changes in natural rubber mechanical behavior during oxidation: Relationship with oxygen consumption

This paper deals with the oxidation of rubber and more specifically with the possibility of setting up relationships between chemical degradation and its impact on mechanical properties for the lifetime prediction of polymers when the degradation process does not follow a single linear Arrhenian behavior. In this study, oxidation of unfilled natural rubber is first characterized at the molecular scale using oxygen consumption measurements for temperatures ranging from 115 °C to 21 °C. The results clearly show that oxidation does not follow a single linear Arrhenian behavior. Oxidation is then characterized at two other scales: the macromolecular scale using swelling measurements, and the macroscopic scale using tensile tests. Based on these findings, the relationship between the amount of oxygen consumed by the rubber and its crosslink density is first proposed within the temperature range of 115 °C to 85 °C. Finally, the relationships between the mechanical properties (Young modulus, elongation, and stress at break) and crosslink density of rubber are discussed.

Tensile behavior of angle ply carbon reinforced PPS laminates under severe thermal aggressions: Homogeneous and heterogeneous temperature conditions

AbstractThis study explores the effects of critical temperature conditions on carbon fiber‐reinforced Poly Phenylene Sulfide (PPS) laminates, focusing on the coupling between thermal and mechanical behaviors. The thermo‐mechanical behavior of angle‐ply laminates is examined under both homogeneous (thermal decomposition and deformation/damage) and heterogeneous (fire) conditions following three primary objectives: (i) Investigate the impact of temperature distribution on the formation of porosities within the composite, considering their significance in thermal transfer and stress concentration—(ii) Evaluate the changes in residual mechanical behavior and properties under tension due to thermally‐induced damage—(iii) Improve the understanding of the interactions between severe thermal exposures and the mechanical behavior. X‐ray tomographic analyses and tensile tests were conducted to achieve these goals. Porosities resulting from thermal damage are identified as a key factor affecting the structural integrity of C/PPS laminates for high‐temperature applications. Mechanical testing reveals that the porosity content significantly reduces the tensile properties (axial stiffness and strength). Under homogeneous temperature conditions, the decrease in the tensile properties is significant up to Tonset (465°C) from which both the axial strength and stiffness dramatically decrease by −75 and −50%, respectively. As exposed to a kerosene flame during 60 s, corresponding to an aggression of 115 kW/m2 on one face of the laminates, the retention of the residual tensile properties remains good (−12% and −22% in stiffness and strength respectively), despite the dramatic decomposition of the polymer matrix. This can be explained from the stress redistribution from the exposed to the back face, and from the role of thermal insulator played by porosities.Highlights Carbon fibers/PPS laminates were subjected to severe thermal aggressions The formation of thermally‐induced porosities is studied A homogeneous aggression significantly decrease the tensile properties (−75%) Once the PPS matrix is severely decomposed, the load transfer is not possible After a 60 s flame exposure, the retention of tensile properties is good (−20%)

Thermo-mechanical aging of carbon-black reinforced styrene-butadiene rubber under cyclic-loading

PurposeThe research aims to investigate the impact of thermo-mechanical aging on SBR under cyclic-loading. By conducting experimental analyses and developing a 3D finite element analysis (FEA) model, it seeks to understand chemical and physical changes during aging processes. This research provides insights into nonlinear mechanical behavior, stress softening and microstructural alterations in SBR compounds, improving material performance and guiding future strategies.Design/methodology/approachThis study combines experimental analyses, including cyclic tensile loading, attenuated total reflection (ATR), spectroscopy and energy-dispersive X-ray spectroscopy (EDS) line scans, to investigate the effects of thermo-mechanical aging (TMA) on carbon-black (CB) reinforced styrene-butadiene rubber (SBR). It employs a 3D FEA model using the Abaqus/Implicit code to comprehend the nonlinear behavior and stress softening response, offering a holistic understanding of aging processes and mechanical behavior under cyclic-loading.FindingsThis study reveals significant insights into SBR behavior during thermo-mechanical aging. Findings include surface roughness variations, chemical alterations and microstructural changes. Notably, a partial recovery of stiffness was observed as a function of CB volume fraction. The developed 3D FEA model accurately depicts nonlinear behavior, stress softening and strain fields around CB particles in unstressed states, predicting hysteresis and energy dissipation in aged SBRs.Originality/valueThis research offers novel insights by comprehensively investigating the impact of thermo-mechanical aging on CB-reinforced-SBR. The fusion of experimental techniques with FEA simulations reveals time-dependent mechanical behavior and microstructural changes in SBR materials. The model serves as a valuable tool for predicting material responses under various conditions, advancing the design and engineering of SBR-based products across industries.

Neurocognitive and neurobehavioral mechanisms of change following psychological treatment for alcohol use disorder

BackgroundAlthough modestly effective treatments exist for alcohol use disorder (AUD), many individuals return to heavy drinking after treatment, suggesting the need for better understanding of factors that contribute to maintaining abstinence or drinking reductions. Whereas past studies identified what treatments work for AUD, recent studies focus more on why particular treatments work, and the mechanisms by which treatment leads to change. This focus on mechanisms of behavior change (MOBC) may inform the process by which treatment leads to better outcomes, and also may lead to new treatments or modifications of existing treatments that target empirically supported mechanisms known to lead to change. There is a paucity of studies examining MOBC from a neurocognitive perspective. MethodTo address this gap in knowledge, the study described here is examining emotional reactivity, alcohol cue reactivity, and cognitive control as potential MOBC at three levels of analysis - self-report, behavior, and neural. ResultsOne hundred ten treatment-seeking individuals with an AUD are being randomized to receive 8 sessions of either Cognitive Behavioral Treatment (CBT) or Mindfulness Based Treatment (MBT) after up to 4 sessions of a platform treatment focused on enhancing motivation to change. To establish the temporal relationship between changes in drinking and changes in MOBC, patients are assessed at baseline, during and immediately after treatment, and 9- and 15-months post-baseline. Relationships between changes in drinking and changes in the proposed MOBC will be examined using advanced mixed modeling techniques. ConclusionsResults should advance AUD treatment by targeting treatments to neurocognitive MOBC.

“I know now that it's something that you can do something about”: Deductive thematic analysis of experiences at an arts-based dementia risk reduction exhibit

Dementia is one of the leading global health crises. Despite the devastating impacts of the illness, general population knowledge pertaining to risk reduction is still limited. Previous research on the impact of dementia risk reduction campaigns has largely focused on awareness rather than behaviour change. Our research introduced an arts-based exhibit to address dementia modifiability, aiming to enhance effectiveness by providing an immersive experience for altering adults’ perceptions of risk reduction and lifestyle behaviours. Interviews were conducted with adults (n = 38 [13 male, 25 female]) who attended an interactive dementia awareness and risk reduction exhibit. Data was analysed using deductive thematic analysis within the Health Belief Model framework to determine key mechanisms of behaviour change. Four key themes encompassing exhibit significance and factors underlying behaviour change were identified. Participants recounted positive experiences, particularly being engaged by the artistic aspects of the exhibit, and recorded heightened engagement in behaviours supporting dementia risk reduction post-exhibit. Areas for improvement included the need for a take-home summary and variation in formats. Participants described prior encounters with dementia and their age as factors which influenced their engagement with dementia risk reduction behaviour, with younger participants reporting lesser engagement with risk reduction information. Our research found that arts-based educational initiatives have the potential to advance public understanding and promote behavioural changes for dementia risk reduction. Our study recommends enhancing the impact of future interventions by employing innovative formats and tailoring them to varied audiences, with a specific emphasis on engaging younger individuals.

Establishment of strain rate‐dependent intrinsic models for short‐cut carbon fiber/nitrile composites in different pyrolysis states

AbstractFlexible nozzle extension technology has been extensively researched throughout the world, but traditional materials cannot meet the growing demands in harsh environments. Short‐cut carbon fiber‐reinforced nitrile rubber (CF/NBR) composites, which are similar to the phenolic impregnated carbon ablator, are currently a hot research topic in this field. The mechanical properties of CF/NBR composites were experimentally tested to study the change in the mechanical behavior of a rocket engine's flexible nozzle extension section under thermal coupling. As indicated by the results, existing models cannot accurately predict changes in materials' mechanical behavior. The theoretical foundation of the nonlinear viscoelastic intrinsic model of rubber is utilized. The uniaxial tensile intrinsic model of CF/NBR composites has been improved by introducing physical parameters, such as fiber reinforcement, strain rate‐dependent correction and temperature‐dependent correction coefficients, and fiber volume fraction. Results show that the intrinsic model developed in this article provides a guide to the uniaxial tensile mechanical behavior of randomly distributed short‐cut CF/NBR composites with known mass‐part formulations and fiber volume fractions at room temperature and under different pyrolysis conditions.

Barriers to Adopting a Plant-Based Diet in High-Income Countries: A Systematic Review.

Adopting a plant-based diet (PBD) has been shown to reduce the risk of developing certain diseases and is linked to environmental benefits. This review synthesises the evidence on the barriers adults aged 18 to 65 living in high-income countries (HIC) may experience when adopting a PBD. A systematic literature review was conducted using four search databases: Medline, Embase, Global Health, and Web of Science. Barriers were mapped to behaviour change strategies using the COM-B model. Ten studies were included in the final review, including 1740 participants. Five were qualitative, four were cross-sectional, and one was a pre- and-post-intervention study. In total, 40 barriers were identified and synthesised into 11 themes: financial, lack of knowledge, emotional, health, convenience, social, enjoyment of meat, environmental, accessibility, personal ability, and media. Of the 40 barriers, nutritional intake/requirements (categorised into the "health" theme) had the most evidence. This barrier encompassed concerns around being able to meet nutritional needs if an individual were to adopt a PBD. Habits (in the "personal ability" theme), which included established eating habits and habitual behaviours relating to animal-source foods, had the second most evidence alongside the barrier of not knowing what to eat as part of a PBD (in the "lack of knowledge" theme). Education interventions and communication/marketing policies were the behaviour change mechanisms mapped onto these barriers. Future interventions should focus on informing individuals about what to consume as part of a nutritionally balanced PBD and facilitating habitual dietary change.

Characterization of FeCoNiCr high-entropy alloys manufactured by powder metallurgy technique

This study explores the phase constitution, thermal behavior, magnetic characteristics, and mechanical properties of FeCoNiCrCux high-entropy alloys (HEAs) produced via powder metallurgy, focusing on varying copper ratios (0–20%). The investigation seeks to understand how the introduction of copper influences the phase composition and properties of FeCoNiCr HEAs, particularly regarding changes in phase structure and mechanical behavior. The phase constitution was analyzed using field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD). Thermal expansion and differential scanning calorimetry (DSC) were employed to study thermal behavior, while vibrating sample magnetometers (VSM) were utilized to assess magnetic properties. Mechanical properties were evaluated through hardness testing. The analysis reveals a shift in phase composition from a single-phase FCC structure to a dual-phase configuration comprising FCC and copper-rich FCC phases as copper content increases. Thermal and magnetic properties were characterized, demonstrating the alloy's behavior under varying conditions. Mechanical tests showed a decrease in hardness with increasing copper content. This study contributes to the understanding of how copper addition affects the phase constitution, thermal behavior, magnetic properties, and mechanical strength of FeCoNiCr HEAs. The observed changes in phase composition and mechanical properties offer insights for tailoring the properties of HEAs for specific applications.

Analysis of the mechanical characteristics of mild steel using different heat treatment

The specimen used in this study to test various mechanical properties is mild steel. Analyzed are the effects of heat treatment (annealing, hardening, and tempering) on a particular specimen's mechanical characteristics. The most significant heat treatment procedures frequently employed to alter the mechanical properties of engineering materials are annealing, hardening, and tempering. Heat treatment is used to examine the mechanical characteristics of iron, which are typically ductility, hardness, yield strength, tensile strength, and impact resistance. Heat treatment increases mechanical qualities like tensile strength, yield strength, ductility, corrosion resistance, and creep rupture in addition to developing hardness and softness. These procedures also increase the effectiveness of the machining and increase their adaptability. Utilizing universal tensile testing equipment for the tensile test, a compression test, and a Rockwell hardness tester for the hardness test, the mechanical behavior of the samples is examined. Heat treating makes it simple to alter the mechanical properties to meet a specific design objective. To examine the impact of various tempering temperatures on the mechanical properties of mild steel, selected samples are heated to various temperatures above the austenitic area, quenched, and then tempered. Tensile strength variations are used to describe the changes in mechanical behavior compared to unquenched samples. Mild steel is used to create tensile test specimens, which are then heated through a variety of processes, including annealing, hardening, and tempering. The results demonstrated that different heat treatments for a specific application can alter and enhance the mechanical properties of mild steel.

Differential Mechanisms of Behavior Change in Cannabis Use Disorder Treatments: Functional Improvements and Clinical Implications

Differential Mechanisms of Behavior Change in Cannabis Use Disorder Treatments: Functional Improvements and Clinical Implications

A continuum scale chemo-mechanical model for multi-trap hydrogen transport in deformed polycrystalline metals

This study presents a coupled multi-trap hydrogen diffusion and crystal plasticity model within a thermodynamically consistent framework. The developed modeling scheme incorporates the hydrogen-enhanced localized plasticity (HELP) and hydrogen-enhanced strain-induced plasticity (HESIV) based on thermodynamic considerations. The theoretical formulations are implemented in the finite element method, which considers the concentration- and chemical potential-based balance equations. The validity of the coupled model is established through preliminary single element simulations under isothermal conditions, showcasing the predictability of evolution of hydrogen concentration and occupancies in the deformed microstructure of polycrystalline metal. Then, the developed computational approach is applied to two materials exhibiting hydrogen-induced hardening and softening behaviors in accordance with the HELP mechanism and vacancy-hydrogen complex (VaH) formation under isothermal condition. The model successfully reproduces the change of mechanical behavior induced by hydrogen in both materials. The effects of hydrogen diffusivity and the binding energy of defects on hydrogen transport are also investigated. Furthermore, the sensitivity of hydrogen diffusion to different trapping mechanisms, local equilibrium trapping and kinetics trapping, is examined. The proposed modeling framework can be applied to new material design strategies for developing metals resistant to hydrogen embrittlement.

Protocol for a hybrid type 3 effectiveness-implementation trial of a pragmatic individual-level implementation strategy for supporting school-based prevention programming

BackgroundFor approximately one in five children who have social, emotional, and behavioral (SEB) challenges, accessible evidence-based prevention practices (EBPPs) are critical. In the USA, schools are the primary setting for children’s SEB service delivery. Still, EBPPs are rarely adopted and implemented by front-line educators (e.g., teachers) with sufficient fidelity to see effects. Given that individual behavior change is ultimately required for successful implementation, focusing on individual-level processes holds promise as a parsimonious approach to enhance impact. Beliefs and Attitudes for Successful Implementation in Schools for Teachers (BASIS-T) is a pragmatic, multifaceted pre-implementation strategy targeting volitional and motivational mechanisms of educators’ behavior change to enhance implementation and student SEB outcomes. This study protocol describes a hybrid type 3 effectiveness-implementation trial designed to evaluate the main effects, mediators, and moderators of the BASIS-T implementation strategy as applied to Positive Greetings at the Door, a universal school-based EBPP previously demonstrated to reduce student disruptive behavior and increase academic engagement.MethodsThis project uses a blocked randomized cohort design with an active comparison control (ACC) condition. We will recruit and include approximately 276 teachers from 46 schools randomly assigned to BASIS-T or ACC conditions. Aim 1 will evaluate the main effects of BASIS-T on proximal implementation mechanisms (attitudes, subjective norms, self-efficacy, intentions to implement, and maintenance self-efficacy), implementation outcomes (adoption, reach, fidelity, and sustainment), and child outcomes (SEB, attendance, discipline, achievement). Aim 2 will examine how, for whom, under what conditions, and how efficiently BASIS-T works, specifically by testing whether the effects of BASIS-T on child outcomes are (a) mediated via its putative mechanisms of behavior change, (b) moderated by teacher factors or school contextual factors, and (c) cost-effective.DiscussionThis study will provide a rigorous test of BASIS-T—a pragmatic, theory-driven, and generalizable implementation strategy designed to target theoretically-derived motivational mechanisms—to increase the yield of standard EBPP training and support strategies.Trial registrationClinicalTrials.gov ID: NCT05989568. Registered on May 30, 2023.

Developing the Healthy Actions and Lifestyles to Avoid Dementia or Hispanos y el ALTo a la Demencia program.

With Alzheimer's disease and related dementias (ADRD) representing an enormous public health challenge, there is a need to support individuals in learning about and addressing their modifiable risk factors (e.g., diet, sleep, and physical activity) to prevent or delay dementia onset. However, there is limited availability for evidence-informed tools that deliver both quality education and support for positive behavior change such as by increasing self-efficacy and personalizing goal setting. Tools that address the needs of Latino/a, at higher risk for ADRD, are even more scarce. We established a multidisciplinary team to develop the Healthy Actions and Lifestyles to Avoid Dementia or Hispanos y el ALTo a la Demencia (HALT-AD) program, a bilingual online personalized platform to educate and motivate participants to modify their risk factors for dementia. Grounded in social cognitive theory and following a cultural adaptation framework with guidance from a community advisory board, we developed HALT-AD iteratively through several cycles of rapid prototype development, user-centered evaluation through pilot testing and community feedback, and refinement. Using this iterative approach allowed for more than 100 improvements in the content, features, and design of HALT-AD to improve the program's usability and alignment with the interests and educational/behavior change support needs of its target audience. Illustrative examples of how pilot data and community feedback informed improvements are provided. Developing HALT-AD iteratively required learning through trial and error and flexibility in workflows, contrary to traditional program development methods that rely on rigid, pre-set requirements. In addition to efficacy trials, studies are needed to identify mechanisms for effective behavior change, which might be culturally specific. Flexible and personalized educational offerings are likely to be important in modifying risk trajectories in ADRD.