Extended one-generation reproductive toxicity study of food-grade titanium dioxide E171 with emphasis on reproductive and endocrine endpoints.

Food-grade titanium dioxide E171 was administered in feed to Sprague Dawley rats in an extended one-generation reproductive toxicity (EOGRT) study (OECD Test 443). The dosed diet (0, 100, 300, or 1000mg/kg body weight/day) started 10 weeks before mating and continued throughout the study. After weaning, pups were allocated to Cohorts 1A/1B (to assess reproductive toxicity), 2A/2B (to assess developmental neurotoxicity), and 3 (to assess developmental immunotoxicity); in addition, Cohort 1B was mated to produce an F2 generation and satellite F0 animals were evaluated for colonic aberrant crypt foci (ACF). In F0 animals, there were no systemic toxicity or reproductive effects, no treatment-related histopathological changes, and no ACF in the colon. Serum estradiol or testosterone concentrations were not changed in F0 or F1 animals. No pre-/postnatal developmental changes related to treatment were noted in F1 animals, and the reproductive performance of F1 Cohort 1B animals was unaffected. F2 pups showed no abnormalities in pre- or postnatal development (postnatal days 4-8). No treatment-related developmental neurotoxicity was observed in Cohorts 2A/2B. Although no treatment-related immunotoxicity was observed in Cohort 3, the positive control did not induce the expected response; this segment of the study will be repeated. Analyses of blood and urine showed negligible systemic absorption of E171 from the gastrointestinal tract upon dietary ingestion. The no observed adverse effect level (NOAEL) for parental systemic toxicity, reproductive toxicity, offspring toxicity, and developmental neurotoxicity was considered 1000mg/kg body weight/day. For developmental immunotoxicity, a NOAEL was not determined owing to insufficient T-cell-dependent antibody response in the positive control. Our study provides robust data on the reproductive toxicity and preneoplastic potential of E171.

Supercritical CO2 and Subcritical H2O Analysis Instrument: Automated Lipid Analysis for In Situ Planetary Life Detection.

The search for extraterrestrial extant or extinct life in our Solar System will require highly capable instrumentation and methods for detecting low concentrations of biosignatures. This paper introduces the Supercritical CO2 and Subcritical H2O Analysis (SCHAN) instrument, a portable and automated system that integrates supercritical fluid extraction (SFE), supercritical fluid chromatography (SFC), and subcritical water extraction coupled with liquid chromatography. The instrument is compact and weighs 6.3 kg, making it suitable for spaceflight missions to planetary bodies. Traditional techniques, such as gas chromatography-mass spectrometry (MS), face challenges with involatile and thermally labile analytes, necessitating derivatization. The SCHAN instrument, however, eliminates the need for derivatization and cosolvents by utilizing neat supercritical CO2 with water as an additive. This SFE-SFC-MS method gives efficient lipid biosignature separations with median detection limits of 10 pg/g (ppt) for fatty acids and 50 pg/g (ppt) for sterols. Several free fatty acids and cholesterol were among the detected peaks in biologically lean samples from the Atacama Desert, demonstrating the instrument's potential for in situ life detection missions. The SCHAN instrument addresses the challenges of conventional systems, offering a compact, portable, and spaceflight-compatible tool for the analysis of organics for future astrobiology-focused missions.

Exploring Sibling Relationship Quality among Latinx Siblings: A Systematic Review.

This systematic review addresses the gap in the literature regarding sibling relationship quality among Latinx families, a topic that has not been comprehensively examined to date. This study aimed to synthesize current research on sibling relationship quality in Latinx families, focusing on the influence of cultural factors, identifying key variables associated with sibling relationship quality, and evaluating the methodological approaches used. This paper is a systematic review based on a recently published evidence and gap map (EGM) that identified and visually presented all published studies investigating sibling relationship quality. Additional inclusion criteria were applied to select articles that specifically examined sibling relationship quality in the United States samples with at least 50% Latinx participants. The review included 12 articles representing 6 distinct studies, revealing significant findings on the roles of familism, simpatía, and gender in shaping sibling dynamics. Results indicated that cultural values such as familism and simpatía positively influence sibling intimacy and warmth, while gender dynamics further moderate these relationships. Methodologically, the articles employed longitudinal and cross-sectional designs, utilizing various quantitative measures. The findings underscore the importance of culturally sensitive approaches in studying sibling relationships and highlight the need for further research to explore these dynamics in diverse Latinx subgroups.

Disparities in HPV Vaccination Among Adolescents by Health Care Facility Type.

Importance: Approximately 31 000 cases of human papillomavirus (HPV)-associated cancers are diagnosed annually in the US. The HPV vaccine can prevent more than 90% of these cancers, yet national uptake remains lower than the Healthy People 2030 target of 80% completion. To devise targeted interventions to increase the uptake of HPV vaccines, it is crucial to understand the vaccination rates across various health care settings. Objective: To examine the association between health care facility type and adolescent HPV vaccine uptake and clinician recommendation for the vaccine in the US. Design, Setting, and Participants: This cross-sectional study uses a complex sampling design of data from the 2020 National Immunization Survey-Teen. The study included adolescents aged 13 to 17 years. The data analysis was completed between March 1 and May 31, 2022. Exposure: Health care facility type classified as public, hospital-based, private, mixed (more than 1 type), and other facilities (eg, military health care facility; Women, Infants, and Children clinic; school-based health center; pharmacy). Main Outcomes and Measures: Initiation of HPV vaccination was defined as the receipt of at least 1 dose of the HPV vaccine and completion as receipt of at least 2 or 3 doses, depending on age of initiation. Parent or guardian self-reported clinician recommendation was categorized as yes or no. Weighted, multivariable logistic regression models were used to estimate the odds of initiating and completing the HPV vaccine series and receiving clinician recommendation by health care facility type adjusted for adolescent and maternal characteristics. Results: A total of 20 162 adolescents (mean [SD] age, 14.9 [1.4] years; 51.0% male) were included. Clinician recommendation for the HPV vaccine was received by 81.4% of adolescents, and 75.1% initiated and 58.6% completed the HPV vaccine series. In the adjusted analyses, adolescents who received recommended vaccinations at public facilities had lower odds of initiating (adjusted odds ratio [AOR], 0.71; 95% CI, 0.58-0.88) and completing (AOR, 0.62; 95% CI, 0.51-0.76) HPV vaccination compared with those who received recommended vaccinations at private facilities. Similarly, adolescents who received recommended vaccinations at public facilities (AOR, 0.62; 95% CI, 0.51-0.77) had lower odds of receiving a clinician recommendation for the HPV vaccine compared with those who received recommended vaccinations at private facilities. Conclusions and Relevance: These findings reveal health disparities in HPV vaccination among adolescent populations served by public health care facilities, suggesting that a greater focus is needed on vaccine recommendations and uptake in public facilities.

The Effects of Structured Mentorship and Onboarding of Novice Nursing Faculty.

BACKGROUND: The United States currently is experiencing a nursing faculty shortage that greatly affects the number of nurses entering professional practice. Nurse faculty transitioning from clinical practice to academia face challenges that may have negative effects on job satisfaction and feelings of competence. Despite barriers, quality nursing faculty are needed. METHOD: This quality improvement project evaluated the effects of an 8-week structured onboarding mentorship on novice nursing faculty's job satisfaction and feelings of competence. Novice faculty were paired with a mentor and completed weekly meetings and an online on-boarding curriculum based on National League for Nursing Nurse Educator Core Competencies. A pretest-posttest design assessed feelings of competence and job satisfaction before and after the 8-week intervention. RESULTS: Findings indicated increased feelings of competence and no change in job satisfaction. CONCLUSION: Outcomes demonstrate how mentorship and structured orientation can positively benefit novice faculty's experiences and competence during their transition into academia. [J Nurs Educ. 2024;63(6):405-408.].

Phasing millions of samples achieves near perfect accuracy, enabling parent-of-origin classification of variants.

Haplotype phasing, the process of determining which genetic variants are physically located on the same chromosome, is crucial for various genetic analyses. In this study, we first benchmark SHAPEIT and Beagle, two state-of-the-art phasing methods, on two large datasets: > 8 million diverse, research-consented 23andMe, Inc. customers and the UK Biobank (UKB). We find that both perform exceptionally well. Beagle's median switch error rate (SER) (after excluding single SNP switches) in white British trios from UKB is 0.026% compared to 0.00% for European ancestry 23andMe research participants; 55.6% of European ancestry 23andMe research participants have zero non-single SNP switches, compared to 42.4% of white British trios. South Asian ancestry 23andMe research participants have the highest median SER amongst the 23andMe populations, but it is still remarkably low at 0.46%. We also investigate the relationship between identity-by-descent (IBD) and SER, finding that switch errors tend to occur in regions of little or no IBD segment coverage. SHAPEIT and Beagle excel at 'intra-chromosomal' phasing, but lack the ability to phase across chromosomes, motivating us to develop an inter-chromosomal phasing method, called HAPTIC ( HAP lotype TI ling and C lustering), that assigns paternal and maternal variants discretely genome-wide. Our approach uses identity-by-descent (IBD) segments to phase blocks of variants on different chromosomes. HAPTIC represents the segments a focal individual shares with their relatives as nodes in a signed graph and performs bipartite clustering on the signed graph using spectral clustering. We test HAPTIC on 1022 UKB trios, yielding a median phase error of 0.08% in regions covered by IBD segments (33.5% of sites). We also ran HAPTIC in the 23andMe database and found a median phase error rate (the rate of mismatching alleles between the inferred and true phase) of 0.92% in Europeans (93.8% of sites) and 0.09% in admixed Africans (92.7% of sites). HAPTIC's precision depends heavily on data from relatives, so will increase as datasets grow larger and more diverse. HAPTIC enables analyses that require the parent-of-origin of variants, such as association studies and ancestry inference of untyped parents.

Reconstructing parent genomes using siblings and other relatives.

Reconstructing the DNA of ancestors from their descendants has the potential to empower phenotypic analyses (including association and genetic nurture studies), improve pedigree reconstruction, and shed light on the ancestral population and phenotypes of ancestors. We developed HAPI-RECAP, a method that reconstructs the DNA of parents from full siblings and their relatives. This tool leverages HAPI2's output, a new phasing approach that applies to siblings (and optionally one or both parents) and reliably infers parent haplotypes but does not link the ungenotyped parents' DNA across chromosomes or between segments flanking ambiguities. By combining IBD between the reconstructed parents and the relatives, HAPI-RECAP resolves the source parent of these segments. Moreover, the method exploits crossovers the children inherited and sex-specific genetic maps to infer the reconstructed parents' sexes. We validated these methods on research participants from both 23andMe, Inc. and the San Antonio Mexican American Family Studies. Given data for one parent, HAPI2 reconstructs large fractions of the missing parent's DNA, between 77.6% and 99.97% among all families, and 90.3% on average in three- and four-child families. When reconstructing both parents, HAPI-RECAP inferred between 33.2% and 96.6% of the parents' genotypes, averaging 70.6% in four-child families. Reconstructed genotypes have average error rates < 10-3, or comparable to those from direct genotyping. HAPI-RECAP inferred the parent sexes 100% correctly given IBD-linked segments and can also reconstruct parents without any IBD. As datasets grow in size, more families will be implicitly collected; HAPI-RECAP holds promise to enable high quality parent genotype reconstruction.

Examining adverse childhood experiences and Black youth's engagement in a hospital-based violence intervention program using administrative data.

BACKGROUND: Stemming from poverty and systemic racism, Black youth are disproportionately represented in hospital-based violence intervention programs (HVIPs) due to greater violence exposure. HVIPs are a critical intervention that have been shown to reduce rates of reinjury in urban hospitals and trauma centers across the United States; however, they are plagued by low enrollment and engagement rates. Few studies have examined factors related to engagement, particularly among Black youth. METHODS: Guided by Trauma Theory and Critical Race Theory, this study uses a retrospective cohort design. Between-group differences of adverse childhood experiences (ACEs) among engaged youth compared to nonengaged youth who were violently injured and recruited for a HVIP were examined using chi-square and logistic regression. ACEs were approximated using a novel approach with administrative data. RESULTS: Results indicated that the total ACE score was not significantly associated with engagement status. Individual ACEs were tested across age groups. CONCLUSIONS: This study highlights a novel approach to understanding ACEs among a hard-to-reach population and illuminates the significant level of ACEs faced by violence-exposed Black youth at young ages. Considering theory, Black families may be more reluctant to engage due to fear and past harms in social service systems stemming from systemic racism. Though ACEs did not predict engagement in this study, considering the high rates of ACEs experienced by Black youth and their families in the context of systemic racism suggests that HVIPs should acknowledge historical harms and foster trauma-informed and healing-centered interactions during recruitment and later stages of engagement.

Decisional Regret Surrounding Dialysis Initiation: A Comparative Analysis.

Rationale & Objective: Dialysis comes with a substantial treatment burden, so patients must select care plans that align with their preferences. We aimed to deepen the understanding of decisional regret with dialysis choices. Study Design: This study had a mixed-methods explanatory sequential design. Setting & Participants: All patients from a single academic medical center prescribed maintenance in-center hemodialysis or presenting for home hemodialysis or peritoneal dialysis check-up during 3 weeks were approached for survey. A total of 78 patients agreed to participate. Patients with the highest (15 patients) and lowest decisional regret (20 patients) were invited to semistructured interviews. Predictors: Decisional regret scale and illness intrusiveness scale were used in this study. Analytical Approach: Quantitatively, we examined correlations between the decision regret scale and illness intrusiveness scale and sorted patients into the highest and lowest decision regret scale quartiles for further interviews; then, we compared patient characteristics between those that consented to interview in high and low decisional regret. Qualitatively, we used an adapted grounded theory approach to examine differences between interviewed patients with high and low decisional regret. Results: Of patients invited to participate in the interviews, 21 patients (8 high regret, 13 low regret) agreed. We observed that patients with high decisional regret displayed resignation toward dialysis, disruption of their sense of self and social roles, and self-blame, whereas patients with low decisional regret demonstrated positivity, integration of dialysis into their identity, and self-compassion. Limitations: Patients with the highest levels of decisional regret may have already withdrawn from dialysis. Patients could complete interviews in any location (eg, home, dialysis unit, and clinical office), which may have influenced patient disclosure. Conclusions: Although all patients experienced disruption after dialysis initiation, patients' approach to adversity differs between patients experiencing high versus low regret. This study identifies emotional responses to dialysis that may be modifiable through patient-support interventions.

As part of a quality improvement initiative in our dialysis practice, a patient stated, "I wish I never started dialysis." This quote served as the catalyst for embarking on a research project with the aim to understand why patients living with end-stage kidney disease have regret about starting and continuing dialysis, a lifesaving but time-intensive measure. We surveyed and interviewed patients on the topic and learned that patients experiencing regret had a disrupted sense of self and blamed themselves for their need of dialysis. Patients with little to no regret demonstrated positivity and self-compassion. These findings will help health care professionals as they work with patients considering dialysis or having newly started dialysis.

Examination of protective factors that promote prosocial skill development among children exposed to intimate partner violence.

This retrospective cohort study examined prosocial skills development in child welfare-involved children, how intimate partner violence (IPV) exposure explained heterogeneity in children's trajectories of prosocial skill development, and the degree to which protective factors across children's ecologies promoted prosocial skill development. Data were from 1,678 children from the National Survey of Child and Adolescent Well-being I, collected between 1999 and 2007. Cohort-sequential growth mixture models were estimated to identify patterns of prosocial skill development between the ages of 3 to 10 years. Four diverse pathways were identified, including two groups that started high (high subtle-decreasing; high decreasing-to-increasing) and two groups that started low (low stable; low increasing-to-decreasing). Children with prior history of child welfare involvement, preschool-age IPV exposure, school-age IPV exposure, or family income below the federal poverty level had higher odds of being in the high decreasing-to-increasing group compared with the high subtle-decreasing group. Children with a mother with greater than high school education or higher maternal responsiveness had higher odds of being in the low increasing-to-decreasing group compared with the low stable group. The importance of maternal responsiveness in fostering prosocial skill development underlines the need for further assessment and intervention. Recommendations for clinical assessment and parenting programs are provided.

Microvascular surgery using surgical loupes versus operating microscope-A single head and neck reconstructive surgeon's experience.

BACKGROUND: This prospective randomized study evaluates surgical outcomes of head and neck free tissue transfer surgery performed by a single head and neck reconstructive surgeon comparing the use of surgical loupes and the operating microscope. METHODS: Cases using surgical loupes were performed under ×3.5 magnification, whereas cases using the microscope were done using the standard operating microscope. Patient demographics, comorbidities, operative details, surgical outcomes, and flap failure were assessed. RESULTS: Eighty-five free tissue transfer surgeries were included. Of these, 51.8% (n = 44) free tissue transfers were performed using loupe magnification and 48.2% (n = 41) were performed using the operating microscope. Total cases requiring intraoperative microvascular anastomosis revision was 12 (15.4%)-of these, 41.7% (n = 5) were originally performed with surgical loupes and 58.3% (n = 7) were with microscope (p = 0.24). CONCLUSION: The current study provides novel, prospective data regarding a single head and neck reconstructive surgeon's experience at a single academic institution. From this, surgical loupes or the operating microscope can be used to perform head and neck microvascular reconstruction with no significant difference in rates of free tissue transfer failure or perioperative complications or outcomes.

A similar injury profile observed in franchise men's and women's cricket in England and Wales: injury surveillance analysis from the first three 'The Hundred' competitions.

Objectives: To describe the injury profile of a novel format cricket competition ('The Hundred') and compare injury incidence and prevalence between the men's and women's competitions. Methods: Medical staff prospectively collected injury data from the eight men's and women's teams during the 2021-2023 competitions. Injury definitions and incidence calculations followed the international consensus statement. Results: In the men's competition, 164 injuries were recorded, compared with 127 in the women's competition. Tournament injury incidence was 36.6 (95% CI 31.4 to 42.7) and 32.5 (95% CI 27.3 to 38.7)/100 players/tournament in the men's and women's competition, respectively. Non-time-loss incidence (men's 26.6 (95% CI 22.2 to 31.8), women's 24.6 (95% CI 20.1 to 30.0)/100 players/tournament) was higher than time-loss incidence (men's 10.0 (95% CI 7.5 to 13.5), women's 7.9 (95% CI 5.6 to 11.3)/100 players/tournament). Injury prevalence was 2.9% and 3.6% in the men's and women's competitions, respectively. Match fielding was the most common activity at injury in both competitions. The thigh and hand were the most common body location time-loss injury in the men's and women's competitions, respectively. Conclusion: A similar injury profile was observed between the men's and women's competition. Preventative strategies targeting thigh injuries in the men's competition and hand injuries in the women's competition would be beneficial. Compared with published injury rates, 'The Hundred' men's presents a greater risk of injury than Twenty20 (T20), but similar to one-day cricket, with 'The Hundred' women's presenting a similar injury risk to T20 and one-day cricket. Additional years of data are required to confirm these findings.

Quantifying Global Origin-Diagnostic Features and Patterns in Biotic and Abiotic Acyclic Lipids for Life Detection.

Lipids are a geologically robust class of organics ubiquitous to life as we know it. Lipid-like soluble organics are synthesized abiotically and have been identified in carbonaceous meteorites and on Mars. Ascertaining the origin of lipids on Mars would be a profound astrobiological achievement. We enumerate origin-diagnostic features and patterns in two acyclic lipid classes, fatty acids (i.e., carboxylic acids) and acyclic hydrocarbons, by collecting and analyzing molecular data reported in over 1500 samples from previously published studies of terrestrial and meteoritic organics. We identify 27 combined (15 for fatty acids, 12 for acyclic hydrocarbons) molecular patterns and structural features that can aid in distinguishing biotic from abiotic synthesis. Principal component analysis (PCA) demonstrates that multivariate analyses of molecular features (16 for fatty acids, 14 for acyclic hydrocarbons) can potentially indicate sample origin. Terrestrial lipids are dominated by longer straight-chain molecules (C4-C34 fatty acids, C14-C46 acyclic hydrocarbons), with predominance for specific branched and unsaturated isomers. Lipid-like meteoritic soluble organics are shorter, with random configurations. Organic solvent-extraction techniques are most commonly reported, motivating the design of our novel instrument, the Extractor for Chemical Analysis of Lipid Biomarkers in Regolith (ExCALiBR), which extracts lipids while preserving origin-diagnostic features that can indicate biogenicity.

Mechanism underlying a brief cognitive behavioral treatment for head and neck cancer survivors with body image distress.

PURPOSE: Body image distress (BID) among head and neck cancer (HNC) survivors is a debilitating toxicity associated with depression, anxiety, stigma, and poor quality of life. BRIGHT (Building a Renewed ImaGe after Head & neck cancer Treatment) is a brief cognitive behavioral therapy (CBT) that reduces BID for these patients. This study examines the mechanism underlying BRIGHT. METHODS: In this randomized clinical trial, HNC survivors with clinically significant BID were randomized to receive five weekly psychologist-led video tele-CBT sessions (BRIGHT) or dose-and delivery matched survivorship education (attention control [AC]). Body image coping strategies, the hypothesized mediators, were assessed using the Body Image Coping Skills Inventory (BICSI). HNC-related BID was measured with the Inventory to Measure and Assess imaGe disturbancE-Head and Neck (IMAGE-HN). Causal mediation analyses were used to estimate the mediated effects of changes in BICSI scores on changes in IMAGE-HN scores. RESULTS: Among 44 HNC survivors with BID allocated to BRIGHT (n = 20) or AC (n = 24), mediation analyses showed that BRIGHT decreased avoidant body image coping (mean change in BICSI-Avoidance scale score) from baseline to 1-month post-intervention relative to AC (p = 0.039). Decreases in BICSI-Avoidance scores from baseline to 1-month resulted in decreases in IMAGE-HN scores from baseline to 3 months (p = 0.009). The effect of BRIGHT on IMAGE-HN scores at 3 months was partially mediated by a decrease in BICSI-Avoidance scores (p = 0.039). CONCLUSIONS: This randomized trial provides preliminary evidence that BRIGHT reduces BID among HNC survivors by decreasing avoidant body image coping. Further research is necessary to confirm these results and enhance the development of interventions targeting relevant pathways to reduce BID among HNC survivors. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03831100 .

Phase-free local ancestry inference mitigates the impact of switch errors on phase-based methods.

Local ancestry inference (LAI) is an indispensable component of a variety of analyses in medical and population genetics, from admixture mapping to characterizing demographic history. However, the accuracy of LAI depends on a number of factors such as phase quality (for phase-based LAI methods), time since admixture of the population under study, and other factors. Here we present an empirical analysis of four LAI methods using simulated individuals of mixed African and European ancestry, examining the impact of variable phase quality and a range of demographic scenarios. We found that regardless of phasing options, calls from LAI methods that operate on unphased genotypes (phase-free LAI) have 2.6-4.6% higher Pearson correlation with the ground truth than methods that operate on phased genotypes (phase-based LAI). Applying the TRACTOR phase-correction algorithm led to modest improvements in phase-based LAI, but despite this, the Pearson correlation of phase-free LAI remained 2.4-3.8% higher than phase-corrected phase-based approaches (considering the best performing methods in each category). Phase-free and phase-based LAI accuracy differences can dramatically impact downstream analyses: estimates of the time since admixture using phase-based LAI tracts are upwardly biased by ≈10 generations using our highest quality phased data but have virtually no bias using phase-free LAI calls. Our study underscores the strong dependence of phase-based LAI accuracy on phase quality and highlights the merits of LAI approaches that analyze unphased genetic data.

Development and Design Needs of Mobile Health (mHealth) Apps for Adolescents.

Context: Adolescent obesity remains a significant public health issue within the United States. Application (app) technology growth and popularity offer new opportunities for research and health improvement. The development of a consolidated mobile health application (mHealth app) for adolescents on these platforms has the potential to improve health outcomes. Most mHealth apps for adolescents, particularly those in the commercial arena, are scaled-down from an adult-targeted app and lack relevant stakeholder feedback. Objectives: To identify adolescent expectations when using an mHealth application and understand visual user-interface needs, and to develop an intuitive and engaging user-interface, we aim to describe the design and functional user requirements for mHealth app. We aim to inform future researchers and app developers about adolescent needs and preferences, as identified by adolescent stakeholders. Study Design: In this mixed method study, we used surveys and interviews/task analysis of adolescents to understand their user requirements and design preferences during the development of a healthy lifestyle app (CommitFit). The survey included the user design industry-standard System Usability Scale (SUS) paired with supplemental questionnaire on the specific features and functionalities of the CommitFit mHealth app. Population Studied: Adolescents ranged from the ages of 13 to 15 years of age, with an average age of 13.6 years old. Results: Ten adolescents were interviewed and surveyed (adapted SUS and supplemental questionnaire) to explore adolescent preferences with visual app design and functionality. Our qualitative results showed that adolescents preferred colorful, user-friendly interfaces paired with gamification to use an mHealth app. Our analysis of SUS survey data validated our user-centered and human-system design and adolescents confirmed their design, feature, and functionality preferences. Adolescent users found CommitFit to be easy to use and provided guidance for visual design needs and preferences. Outcomes: Adolescent stakeholder feedback is crucial in the successful development of an adolescent-targeted mHealth app. Adolescents prefer vibrant colors, modern, easy-to-use interface, gamification and rewards, customizable and personalized, simple, and mature graphics. Adolescents were especially motivated by gamification techniques in maintaining their interest in the application and their health behavior goals.