Geometric latches enable tuning of ultrafast, spring-propelled movements.

The smallest, fastest, repeated-use movements are propelled by power-dense elastic mechanisms, yet the key to their energetic control may be found in the latch-like mechanisms that mediate transformation from elastic potential energy to kinetic energy. Here, we tested how geometric latches enable consistent or variable outputs in ultrafast, spring-propelled systems. We constructed a reduced-order mathematical model of a spring-propelled system that uses a torque reversal (over-center) geometric latch. The model was parameterized to match the scales and mechanisms of ultrafast systems, specifically snapping shrimp. We simulated geometric and energetic configurations that enabled or reduced variation of strike durations and dactyl rotations given variation of stored elastic energy and latch mediation. Then, we collected an experimental dataset of the energy storage mechanism and ultrafast snaps of live snapping shrimp (Alpheus heterochaelis) and compared our simulations with their configuration. We discovered that snapping shrimp deform the propodus exoskeleton prior to the strike, which may contribute to elastic energy storage. Regardless of the amount of variation in spring loading duration, strike durations were far less variable than spring loading durations. When we simulated this species' morphological configuration in our mathematical model, we found that the low variability of strike duration is consistent with their torque reversal geometry. Even so, our simulations indicate that torque reversal systems can achieve either variable or invariant outputs through small adjustments to geometry. Our combined experiments and mathematical simulations reveal the capacity of geometric latches to enable, reduce or enhance variation of ultrafast movements in biological and synthetic systems.

Dual spring force couples yield multifunctionality and ultrafast, precision rotation in tiny biomechanical systems.

Small organisms use propulsive springs rather than muscles to repeatedly actuate high acceleration movements, even when constrained to tiny displacements and limited by inertial forces. Through integration of a large kinematic dataset, measurements of elastic recoil, energetic math modeling and dynamic math modeling, we tested how trap-jaw ants (Odontomachus brunneus) utilize multiple elastic structures to develop ultrafast and precise mandible rotations at small scales. We found that O. brunneus develops torque on each mandible using an intriguing configuration of two springs: their elastic head capsule recoils to push and the recoiling muscle-apodeme unit tugs on each mandible. Mandibles achieved precise, planar, circular trajectories up to 49,100 rad s-1 (470,000 rpm) when powered by spring propulsion. Once spring propulsion ended, the mandibles moved with unconstrained and oscillatory rotation. We term this mechanism a 'dual spring force couple', meaning that two springs deliver energy at two locations to develop torque. Dynamic modeling revealed that dual spring force couples reduce the need for joint constraints and thereby reduce dissipative joint losses, which is essential to the repeated use of ultrafast, small systems. Dual spring force couples enable multifunctionality: trap-jaw ants use the same mechanical system to produce ultrafast, planar strikes driven by propulsive springs and for generating slow, multi-degrees of freedom mandible manipulations using muscles, rather than springs, to directly actuate the movement. Dual spring force couples are found in other systems and are likely widespread in biology. These principles can be incorporated into microrobotics to improve multifunctionality, precision and longevity of ultrafast systems.

African American Adolescent Mothers' Childbirth Support From Fathers, Grandmothers, Nurses, Doctors, and Doulas.

The morning after giving birth in a large urban hospital, 121 African American adolescents participating in a community doula program identified the people who had been with them during labor and birth and narrated their birth stories. Besides medical providers, the people most likely to be present for the birth were the infants' fathers (n = 73, 60%), the mothers' mothers (n = 70, 58%), and their doulas (n = 100, 83%). Birth stories were coded to identify types of support provided by different people. Mothers' mothers, infants' fathers, and doulas were more likely to be mentioned in the stories as providers of emotional and instrumental support than were medical providers. Doulas were more likely to be mentioned as providers of information than were family members or medical providers.

Plasticity of the gastrocnemius elastic system in response to decreased work and power demand during growth.

Elastic energy storage and release can enhance performance that would otherwise be limited by the force-velocity constraints of muscle. Although functional influence of a biological spring depends on tuning between components of an elastic system (the muscle, spring-driven mass and lever system), we do not know whether elastic systems systematically adapt to functional demand. To test whether altering work and power generation during maturation alters the morphology of an elastic system, we prevented growing guinea fowl (Numida meleagris) from jumping. We compared the jump performance of our treatment group at maturity with that of controls and measured the morphology of the gastrocnemius elastic system. We found that restricted birds jumped with lower jump power and work, yet there were no significant between-group differences in the components of the elastic system. Further, subject-specific models revealed no difference in energy storage capacity between groups, though energy storage was most sensitive to variations in muscle properties (most significantly operating length and least dependent on tendon stiffness). We conclude that the gastrocnemius elastic system in the guinea fowl displays little to no plastic response to decreased demand during growth and hypothesize that neural plasticity may explain performance variation.

The national landscape of culminating experiences in master's programs in health and biomedical informatics.

Health and biomedical informatics graduate-level degree programs have proliferated across the United States in the last 10 years. To help inform programs on practices in teaching and learning, a survey of master's programs in health and biomedical informatics in the United States was conducted to determine the national landscape of culminating experiences including capstone projects, research theses, internships, and practicums. Almost all respondents reported that their programs required a culminating experience (97%). A paper (not a formal thesis), an oral presentation, a formal course, and an internship were required by ≥50% programs. The most commonly reported purposes for the culminating experience were to help students extend and apply the learning and as a bridge to the workplace. The biggest challenges were students' maturity, difficulty in synthesizing information into a coherent paper, and ability to generate research ideas. The results provide students and program leaders with a summary of pedagogical methods across programs.

Making meaning of motherhood: Self and life transitions among African American adolescent mothers.

Although adolescent childbearing is widely viewed as a major social problem, and research suggests that young mothers and their children are at risk for poor economic and academic outcomes, these ideas may be in need of revision. Recent scholarship has pointed out that young mothers have been unfairly blamed and stigmatized for problems that should be attributed to social and economic inequality, racism, and poverty. The present study extends that research by listening to the voices of young mothers. In total, 179 urban African American women were asked at 4, 12, and 24 months after giving birth to describe how their lives had changed since becoming a mother. A team of coders content coded themes with rigorous checks for intercoder reliability. Positive themes were far more prevalent than negative themes. Motherhood was often described as a positive developmental change, providing the young women with a sense of maturity, responsibility, motivation, and commitment to placing the baby's needs ahead of their own. Motherhood was sometimes described as a life-turning point whereby young women turned away from undesirable activities and became focused on school, work, and their family's future. Challenges reflected common stresses of parenting for people of all ages, such as lack of sleep and burden of caregiving, but also limited time to socialize with friends. Findings suggest that although policymakers and professionals view adolescent parenthood as a social ill to be eradicated, for the mothers themselves, the experience is more complex, meaningful, and positive. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Altering the Mechanical Load Environment During Growth Does Not Affect Adult Achilles Tendon Properties in an Avian Bipedal Model.

Tendon mechanical properties respond to altered load in adults, but how load history during growth affects adult tendon properties remains unclear. To address this question, we adopted an avian model in which we altered the mechanical load environment across the growth span. Animals were divided at 2 weeks of age into three groups: (1) an exercise control group given the opportunity to perform high-acceleration movements (EXE, n = 8); (2) a sedentary group restricted from high-intensity exercise (RES, n = 8); and (3) a sedentary group also restricted from high-intensity exercise and in which the gastrocnemius muscles were partially paralyzed using repeated bouts of botulinum toxin-A injections (RES-BTX, n = 8). Video analysis of bird movement confirmed the restrictions eliminated high-intensity exercise and did not alter time spent walking and sitting between groups. At skeletal maturity (33-35 weeks) animals were sacrificed for analysis, consisting of high-field MRI and material load testing, of both the entire free Achilles tendon and the tendon at the bone-tendon junction. Free tendon stiffness, modulus, and hysteresis were unaffected by variation in load environment. Further, the bone-tendon junction cross-sectional area, stress, and strain were also unaffected by variations in load environment. These results suggest that: (a) a baseline level of low-intensity activity (standing and walking) may be sufficient to maintain tendon growth; and (b) if this lower threshold of tendon load is met, non-mechanical mediated tendon growth may override the load-induced mechanotransduction signal attributed to tendon remodeling in adults of the same species. These results are important for understanding of musculoskeletal function and tendon health in growing individuals.

Using big data in pediatric oncology: Current applications and future directions.

Pediatric cancer is a rare disease with a low annual incidence, which presents a significant challenge in being able to collect enough data to fuel clinical discoveries. Big data registry trials hold promise to advance the study of pediatric cancers by allowing for the combination of traditional randomized controlled trials with the power of larger cohort sizes. The emergence of big data resources and data-sharing initiatives are becoming transformative for pediatric cancer diagnosis and treatment. This review discusses the uses of big data in pediatric cancer, existing pediatric cancer registry initiatives and research, the challenges in harmonizing these data to improve accessibility for study, and building pediatric data commons and other important future endeavors.

The integration of sensory feedback in the modulation of anuran landing preparation.

Controlled landing requires preparation. Mammals and bipedal birds vary how they prepare for landing by predicting the timing and magnitude of impact from the integration of visual and non-visual information. Here, we explore how the cane toad Rhinella marina - an animal that moves primarily through hopping - integrates sensory information to modulate landing preparation. Earlier work suggests that toads may modulate landing preparation using predictions of impact timing and/or magnitude based on non-visual sensory feedback during takeoff rather than visual cues about the landing itself. We disentangled takeoff and landing conditions by hopping toads off platforms of different heights while measuring electromyographic (EMG) activity of an elbow extensor (m. anconeus) and capturing high-speed images to quantify whole body and forelimb kinematics. This enabled us to test how toads integrate visual and non-visual information in landing preparation. We asked two questions: (1) when they conflict, do toads correlate landing preparation with takeoff or landing conditions? And (2) for hops with the same takeoff conditions, does visual information alter the timing of landing preparation? We found that takeoff conditions are a better predictor of the onset of landing preparation than landing conditions, but that visual information is not ignored. When hopping off higher platforms, toads start to prepare for landing later when takeoff conditions are invariant. This suggests that, unlike mammals, toads prioritize non-visual sensory feedback about takeoff conditions to coordinate landing, but that they do integrate visual information to fine-tune landing preparation.

Eliminating high-intensity activity during growth reduces mechanical power capacity but not submaximal metabolic cost in a bipedal animal model.

Decreases in activity levels in children worldwide are feared to have long-term health repercussions. Yet, because of the difficulty of performing controlled long-term studies in humans, we do not yet understand how decreases in childhood activity influence adult functional capacity. Here, in an avian bipedal model, we evaluated the elimination of all high-intensity activity during growth on adult performance. We evaluated three alternative hypotheses: Elimination of high-intensity activity 1) does not influence adult function, 2) results in task-specific deficits in adulthood, or 3) results in deficits that generalize across locomotor tasks. We found that animals restricted from jumping and sprinting during growth showed detriments as adults in maximal jump performance in comparison to controls, but did not require more metabolic energy during steady-state running or standing. From this, we conclude that functional deficits from elimination of high-intensity exercise are task specific and do not generalize across all locomotor functions.NEW & NOTEWORTHY Decreasing childhood activity levels are feared to have long-term health repercussions, but testing this hypothesis is hampered by restrictions of human experimentation. Here, in a bipedal animal model, we examine how the elimination of high-intensity activity during all of maturation influences adult locomotor capacity. We found restricted activity during growth reduced mechanical power capacity but not submaximal metabolic cost. This suggests that reduced childhood activity may result in task-specific, rather than generalized locomotor deficits.

The principles of cascading power limits in small, fast biological and engineered systems.

Mechanical power limitations emerge from the physical trade-off between force and velocity. Many biological systems incorporate power-enhancing mechanisms enabling extraordinary accelerations at small sizes. We establish how power enhancement emerges through the dynamic coupling of motors, springs, and latches and reveal how each displays its own force-velocity behavior. We mathematically demonstrate a tunable performance space for spring-actuated movement that is applicable to biological and synthetic systems. Incorporating nonideal spring behavior and parameterizing latch dynamics allows the identification of critical transitions in mass and trade-offs in spring scaling, both of which offer explanations for long-observed scaling patterns in biological systems. This analysis defines the cascading challenges of power enhancement, explores their emergent effects in biological and engineered systems, and charts a pathway for higher-level analysis and synthesis of power-amplified systems.

Use of Wearable, Mobile, and Sensor Technology in Cancer Clinical Trials.

As the availability and sophistication of mobile health (mHealth) technology (wearables, mobile technology, and sensors) continues to increase, there is great promise that these tools will be transformative for clinical trials and drug development. This review provides an overview of the current landscape of potential measurement options, including the various types of data collected, methods/tools for collecting them, and a crosswalk of available options. The opportunities and potential drawbacks of mHealth in cancer clinical trials are discussed. Specific concerns related to data accuracy, provenance, and regulatory issues are highlighted, with suggestions for how to address these in future research. Next steps for establishing mHealth methods and tools as legitimate and accepted measures in oncology clinical trials include continuation of regulatory definition by the FDA; establishment of security standards and protocols; refinement and implementation of methods to establish and document data accuracy; and finally, creation of feedback loops wherein regulators receive updates from researchers with better and more timely data, which should decrease trial times and lessen drug development costs. Implementing mHealth technologies into cancer clinical trials has the potential to transform and propel oncology drug development and precision medicine to keep pace with the rapidly increasing developments in genomics and immunology.

Data Commons to Support Pediatric Cancer Research.

The falling costs and increasing fidelity of high-throughput biomedical research data have led to a renaissance in cancer surveillance and treatment. Yet, the amount, velocity, and complexity of these data have overcome the capacity of the increasing number of researchers collecting and analyzing this information. By centralizing the data, processing power, and tools, there is a valuable opportunity to share resources and thus increase the efficiency, power, and impact of research. Herein, we describe current data commons and how they operate in the oncology landscape, including an overview of the International Neuroblastoma Risk Group data commons as a paradigm case. We outline the practical steps and considerations in building data commons. Finally, we discuss the unique opportunities and benefits of creating a data commons within the context of pediatric cancer research, highlighting the particular advantages for clinical oncology and suggested next steps.

A comprehensive peer network intervention to improve social communication of children with autism spectrum disorders: a randomized trial in kindergarten and first grade.

The purpose of this randomized control group study was to examine the effects of a peer network intervention that included peer mediation and direct instruction for Kindergarten and First-grade children with autism spectrum disorders. Trained school staff members provided direct instruction for 56 children in the intervention group, and 39 children participated in a comparison group. Results showed children in the intervention group displayed significantly more initiations to peers than did the comparison group during non-treatment social probes and generalization probes. Treatment session data showed significant growth for total communications over baseline levels. Children in treatment also showed more growth in language and adaptive communication. Finally, teachers' ratings of prosocial skills revealed significantly greater improvements for the intervention group.

Indirect evidence for elastic energy playing a role in limb recovery during toad hopping.

Elastic energy is critical for amplifying muscle power during the propulsive phase of anuran jumping. In this study, we use toads (Bufo marinus) to address whether elastic recoil is also involved after take-off to help flex the limbs before landing. The potential for such spring-like behaviour stems from the unusually flexed configuration of a toad's hindlimbs in a relaxed state. Manual extension of the knee beyond approximately 90° leads to the rapid development of passive tension in the limb as underlying elastic tissues become stretched. We hypothesized that during take-off, the knee regularly extends beyond this, allowing passive recoil to help drive limb flexion in mid-air. To test this, we used high-speed video and electromyography to record hindlimb kinematics and electrical activity in a hindlimb extensor (semimembranosus) and flexor (iliofibularis). We predicted that hops in which the knees extended further during take-off would require less knee flexor recruitment during recovery. Knees extended beyond 90° in over 80% of hops, and longer hops involved greater degrees of knee extension during take-off and more intense semimembranosus activity. However, knee flexion velocities during recovery were maintained despite a significant decrease in iliofibularis intensity in longer hops, results consistent with elastic recoil playing a role.

Peer Mediation to Increase Communication and Interaction at Recess for Students with Autism Spectrum Disorders.

Recess plays an integral role in the social and emotional development of children given the time provided to engage in interactions with others and practice important social skills. Students with ASD, however, typically fail to achieve even minimal benefit from recess due to social and communication impairments as well as a tendency to withdraw. Implementation of evidence-based interventions such as peer-mediated social skills groups, are necessary to ensure recess is an advantageous learning environment for students with ASD. A multiple-baseline design across participants was used to determine if a functional relationship exists between a social skills instructional program combined with peer networks with school staff as implementers and increases in level of communicative acts for participants with ASD at recess. Results indicate all participants demonstrated an immediate increase in the number of communicative acts with the introduction of the intervention. Implications for practice are discussed.

The delivery of heavy menstrual bleeding services in England and Wales after publication of national guidelines: a survey of hospitals.

BACKGROUND: In 2007-2008, two UK-based organisations, the National Institute for Health and Clinical Excellence and the Royal College of Obstetricians and Gynaecologists, published guidelines for the management of care and organisation of outpatient services for women with heavy menstrual bleeding (HMB). In 2010, this study was conducted to provide an update on guideline-related services provided in England and Wales, and whether they are consistent with national clinical guidelines two to three years after publication. METHODS: An organisational survey of outpatient gynaecology clinics was conducted of 221 hospitals in 154 acute National Health Service (NHS) trusts in England and Wales. A questionnaire was distributed to all hospitals to examine provision of diagnostic and therapeutic services in outpatient settings. Descriptive statistics were used to summarize results. RESULTS: The response rate was 100%. For diagnosis, 80% of hospitals had ultrasound, 87% had hysteroscopy, and 98% had endometrial biopsy available. Overall, 76% of hospitals provided an information leaflet, 8% referred patients to a website for information, and 20% did not provide any written information. A dedicated menstrual bleeding clinic was present in 38% of hospitals. Only 30% of hospitals reported that they have a local written protocol regarding the care and management of women with HMB. CONCLUSION: The majority of hospitals offer appropriate diagnostic and surgical services for women with HMB. However, local protocol development may not reflect the local services. It may be that hospitals are finding it difficult to summon resources to provide clinics for women with menstrual disorders.

A case of dysphoric milk ejection reflex (D-MER).

Dysphoric milk ejection reflex (D-MER) results in waves of negative emotions that last from shortly before initial milk ejection until baby starts to feed vigorously Symptoms may decrease by 3 months or they may continue throughout the breastfeeding period. This report is a case study of an Australian mother who experienced D-MER with her fourth child.

Parent relationship quality and infant-mother attachment.

This project examined interrelations between father-mother conflict, father support of mother, maternal behavior, and infant-mother attachment within a sample of 79 African American families living in a highly stressed urban community. Father support of mother was not related to maternal parenting behavior or infant attachment. Conflicted mother-father relationships were associated with problematic maternal behavior, low maternal sensitivity, infant attachment insecurity, and infant attachment disorganization. The associations between parental conflict and both infant attachment disorganization and insecurity were buffered in families in which fathers co-resided with the mother. Consistent with theory and prior research, links were also observed between maternal sensitive-responsiveness and infant attachment security and between problematic maternal parenting and infant attachment disorganization. However, maternal parenting behavior did not mediate the relation between parental conflict and infant attachment. Results are discussed with respect to whether and under what circumstances child exposure to parent conflict can have a direct effect on infant-mother attachment that is not mediated through dyadic infant-mother interaction.

Reliability of a preventability model in maternal death and morbidity.

OBJECTIVE: The purpose of this study was to measure the reliability of a model that defines preventability in maternal morbidity and death. STUDY DESIGN: One hundred cases of serious morbidity and death among peripartum women were reviewed by 2 independent groups of medical experts to identify potentially preventable provider or system events that may have led to the progression of illness. RESULTS: Seventy-seven percent of the cases had concordant findings in both groups regarding the identification of any preventable events. Interrater agreement, which was measured by Cohen's Kappa, was 0.49, which suggests moderate to good reliability. Cases with multiple comorbidities, poor documentation, or preventable patient factors tended to have higher levels of disagreement. CONCLUSION: There was high agreement between the 2 groups regarding the identification of preventable events that impact maternal morbidity and death. The reliability of this model for the assessment of preventability is an important step for improvement in obstetric and medical care.