Modeling and Parameter Estimation of an Actuator for Prosthetic Joints

A mathematical model was developed for a linear actuator to be used in a powered leg prosthesis. The model consists of a differential equation relating motor voltage, external force and velocity. All model parameters were known from manufacturer\u27s data, except inertia and friction. A numerical simulation was prepared to estimate these parameters from experimental data. Experiments were conducted and a numerical search was performed to arrive at parameter values that closely fit the data. The mathematical model will be used in subsequent control development work.https://engagedscholarship.csuohio.edu/u_poster_2014/1005/thumbnail.jp

The Diterpenoid 7-Keto-Sempervirol, Derived from Lycium chinense, Displays Anthelmintic Activity against both Schistosoma mansoni and Fasciola hepatica

BACKGROUND:Two platyhelminths of biomedical and commercial significance are Schistosoma mansoni (blood fluke) and Fasciola hepatica (liver fluke). These related trematodes are responsible for the chronic neglected tropical diseases schistosomiasis and fascioliasis, respectively. As no vaccine is currently available for anti-flukicidal immunoprophylaxis, current treatment is mediated by mono-chemical chemotherapy in the form of mass drug administration (MDA) (praziquantel for schistosomiasis) or drenching (triclabendazole for fascioliasis) programmes. This overreliance on single chemotherapeutic classes has dramatically limited the number of novel chemical entities entering anthelmintic drug discovery pipelines, raising significant concerns for the future of sustainable blood and liver fluke control. METHODOLOGY/ PRINCIPLE FINDINGS:Here we demonstrate that 7-keto-sempervirol, a diterpenoid isolated from Lycium chinense, has dual anthelmintic activity against related S. mansoni and F. hepatica trematodes. Using a microtiter plate-based helminth fluorescent bioassay (HFB), this activity is specific (Therapeutic index = 4.2, when compared to HepG2 cell lines) and moderately potent (LD50 = 19.1 μM) against S. mansoni schistosomula cultured in vitro. This anti-schistosomula effect translates into activity against both adult male and female schistosomes cultured in vitro where 7-keto-sempervirol negatively affects motility/behaviour, surface architecture (inducing tegumental holes, tubercle swelling and spine loss/shortening), oviposition rates and egg morphology. As assessed by the HFB and microscopic phenotypic scoring matrices, 7-keto-sempervirol also effectively kills in vitro cultured F. hepatica newly excysted juveniles (NEJs, LD50 = 17.7 μM). Scanning electron microscopy (SEM) evaluation of adult F. hepatica liver flukes co-cultured in vitro with 7-keto-sempervirol additionally demonstrates phenotypic abnormalities including breaches in tegumental integrity and spine loss. CONCLUSIONS/ SIGNIFICANCE:7-keto-sempervirol negatively affects the viability and phenotype of two related pathogenic trematodes responsible for significant human and animal infectious diseases. This plant-derived, natural product is also active against both larval and adult developmental forms. As such, the data collectively indicate that 7-keto-sempervirol is an important starting point for anthelmintic drug development. Medicinal chemistry optimisation of more potent 7-keto-sempervirol analogues could lead to the identification of novel chemical entities useful for future combinatorial or replacement anthelmintic control

A neural basis for contagious yawning

Contagious yawning, in which yawning is triggered involuntarily when we observe another person yawn, is a common form of echophenomena—the automatic imitation of another’s words (echolalia) or actions (echopraxia) [1]. The neural basis for echophenomena is unknown; however, it has been proposed that it is linked to disinhibition of the human mirror-neuron system [1–4 ] and hyper-excitability of cortical motor areas [ 1 ]. We investigated the neural basis for contagious yawning using transcranial magnetic stimulation (TMS). Thirty-six adults viewed video clips that showed another individual yawning and, in separate blocks, were instructed to either resist yawning or allow themselves to yawn. Participants were videoed throughout and their yawns or stifled yawns were counted. We used TMS to quantify motor cortical excitability and physiological inhibition for each participant, and these measures were then used to predict the propensity for contagious yawning across participants. We demonstrate that instructions to resist yawning increase the urge to yawn and alter how yawns are expressed (i.e., full versus stifled yawns) but do not alter the individual propensity for contagious yawning. By contrast, TMS measures of cortical excitability and physiological inhibition were significant predictors of contagious yawning and accounted for approximately 50% of the variability in contagious yawning. These data demonstrate that individual variability in the propensity for contagious yawning is determined by cortical excitability and physiological inhibition in the primary motor cortex

Chiral symmetry breaking in dimensionally regularized nonperturbative quenched QED

In this paper we study dynamical chiral symmetry breaking in dimensionally regularized quenched QED within the context of Dyson-Schwinger equations. In D < 4 dimensions the theory has solutions which exhibit chiral symmetry breaking for all values of the coupling. To begin with, we study this phenomenon both numerically and, with some approximations, analytically within the rainbow approximation in the Landau gauge. In particular, we discuss how to extract the critical coupling alpha_c = pi/3 relevant in four dimensions from the D dimensional theory. We further present analytic results for the chirally symmetric solution obtained with the Curtis-Pennington vertex as well as numerical results for solutions exhibiting chiral symmetry breaking. For these we demonstrate that, using dimensional regularization, the extraction of the critical coupling relevant for this vertex is feasible. Initial results for this critical coupling are in agreement with cut-off based work within the currently achievable numerical precision.Comment: 24 pages, including 5 figures; submitted to Phys. Rev.

Accessing local support online: Mothers' experiences of local Breastfeeding Support Facebook groups

The importance of support to breastfeeding success is well established, as are the difficulties many mothers face in accessing the support they need. With the majority of UK mothers now accessing social media for support, Breastfeeding Support Facebook (BSF) groups have increased exponentially. BSF groups vary in type (local or national/international) and in moderation—overseen by breastfeeding mothers and by midwives or trained lactation specialists. Some groups aimed at supporting mothers in a specific geographical area also have associated face-to-face groups, facilitated as either professional or peer support. Little is currently known about these specific local groups, their prevalence, impact or value to mothers. This paper examines mothers' experiences of using local BSF groups and why they value them as part of a larger study exploring the impact of midwife moderation on these groups. An online survey consisting of open and closed questions was completed by 2028 mothers. Findings identified that local BSF groups are widely used and highly valued for their connection with local face-to-face services and other mothers. They offer access to expertise and shared experience in a format mothers find convenient and timely, improving confidence and self-efficacy. Local BSF groups enable the formation of support networks and development of breastfeeding knowledge that mothers credit with increased well-being, motivation and breastfeeding duration. As such, they have the potential to add value to local face-to-face services and improve breastfeeding experiences and knowledge in communities. The findings have important implications to support the development of integrated online interventions to improve public health

The Composition of Planetesimal 5145 Pholus

We present a new spectrum of 5145 Pholus between 1.15 and 2.4 microns. We model this, and the previously published (0.4-1.0 microns) spectrum, using Hapke scattering theory. The 2.04 micron band of H2O ice is seen in absorption, as well as a strong band at 2.27 Am, interpreted as frozen methanol and/or the methanol photo product hexamethylenetetramine (HMT). The presence of small molecules is indicative of a chemically primitive surface, since heating removes the light hydrocarbons in favor of macromolecular carbon typically found in carbonaceous meteorites. The unusually red slope of Pholus' spectrum is matched by fine grains of Titan tholin, as found previously. Object 1993 HA2, which has an orbit similar to that of 5145 Pholus, is similarly red, but there are as yet no observations of absorption bands in its spectrum. We present a model for the composite spectrum of all spectroscopic and photometric data available for 5145 Pholus and conclude that this is a primitive object which has yet to be substantially processed by solar heat

Measuring psychological need states in sport: Theoretical considerations and a new measure

© 2019 Elsevier Ltd Objectives: Research guided by Self-determination Theory (Deci & Ryan, 1985; Ryan & Deci, 2017) has repeatedly demonstrated the importance of focusing on both the bright (satisfaction) and dark (frustration) sides of the three basic psychological needs. Recently, researchers have also argued for the utility of assessing a third need state, that of “unfulfillment”. In this paper, we outline an effort to develop and provide initial validity evidence for scores of a new multidimensional and sport-specific measure, the Psychological Need States in Sport-Scale (PNSS-S), to assess the satisfaction, frustration, and unfulfillment of all three needs. Method: In Study 1, we developed 46 candidate items, and tested evidence for the factorial structure of the responses to the newly developed items, internal consistency and discriminant validity of the subscale scores. Following refinement, the replication of the favored model was tested using an independent sample of athletes in Study 2. Evidence for the nomological network of the subscales of the new measure was also demonstrated in Study 2. Results: Factor models incorporating all three need states showed poor fit with the data. However, following post-hoc modifications, a six-factor model assessing the need states of satisfaction and frustration, separately for autonomy, competence, and relatedness, was found to have good fit to the data. After refinement, the 29-item six-factor model was found to demonstrate good fit, good standardized factor loadings, factor correlations in the expected directions, and acceptable estimates of internal consistency in Study 2. Tests of nomological networks showed that the six need states were significantly predicted by contextual autonomy, competence, and relatedness support/thwarts as expected. Autonomy and competence need satisfaction were significantly associated with engagement; and competence and relatedness need satisfaction were significantly associated with positive affect. In addition, autonomy and competence need frustration were significantly associated with exhaustion and all three need frustration states significantly predicted negative affect. Conclusions: A tripartite conceptualization of the need states was not empirically supported. Nevertheless, the PNSS-S makes a unique contribution to the sport literature, as it represents the first sport-specific measure of six distinct, yet, correlated states of the satisfaction and frustration of autonomy, competence, and relatedness needs

Identifying change processes in group-based health behaviour-change interventions: development of the mechanisms of action in group-based interventions (MAGI) framework

Group-based interventions are widely used to promote health-related behaviour change. While processes operating in groups have been extensively described, it remains unclear how behaviour change is generated in group-based health-related behaviour-change interventions. Understanding how such interventions facilitate change is important to guide intervention design and process evaluations. We employed a mixed-methods approach to identify, map and define change processes operating in group-based behaviour-change interventions. We reviewed multidisciplinary literature on group dynamics, taxonomies of change technique categories, and measures of group processes. Using weight-loss groups as an exemplar, we also reviewed qualitative studies of participants' experiences and coded transcripts of 38 group sessions from three weight-loss interventions. Finally, we consulted group participants, facilitators and researchers about our developing synthesis of findings. The resulting 'Mechanisms of Action in Group-based Interventions' (MAGI) framework comprises six overarching categories: (1) group intervention design features, (2) facilitation techniques, (3) group dynamic and development processes, (4) inter-personal change processes, (5) selective intra-personal change processes operating in groups, and (6) contextual influences. The framework provides theoretical explanations of how change occurs in group-based behaviour-change interventions and can be applied to optimise their design and delivery, and to guide evaluation, facilitator training and further research

The Future Proofing Study: Design, methods and baseline characteristics of a prospective cohort study of the mental health of Australian adolescents

Objectives: The Future Proofing Study (FPS) was established to examine factors associated with the onset and course of mental health conditions during adolescence. This paper describes the design, methods, and baseline characteristics of the FPS cohort. Methods: The FPS is an Australian school-based prospective cohort study with an embedded cluster-randomized controlled trial examining the effects of digital prevention programs on mental health. Data sources include self-report questionnaires, cognitive functioning, linkage to health and education records, and smartphone sensor data. Participants are assessed annually for 5 years. Results: The baseline cohort (N = 6388, M = 13.9 years) is broadly representative of the Australian adolescent population. The clinical profile of participants is comparable to other population estimates. Overall, 15.1% of the cohort met the clinical threshold for depression, 18.6% for anxiety, 31.6% for psychological distress, and 4.9% for suicidal ideation. These rates were significantly higher in adolescents who identified as female, gender diverse, sexuality diverse, or Aboriginal and/or Torres Strait Islander (all ps < 0.05). Conclusions: This paper provides current and comprehensive data about the status of adolescent mental health in Australia. The FPS cohort is expected to provide significant insights into the risk, protective, and mediating factors associated with development of mental health conditions during adolescence

Intervention mapping for development of a participatory return-to-work intervention for temporary agency workers and unemployed workers sick-listed due to musculoskeletal disorders

BACKGROUND: In the past decade in activities aiming at return-to-work (RTW), there has been a growing awareness to change the focus from sickness and work disability to recovery and work ability. To date, this process in occupational health care (OHC) has mainly been directed towards employees. However, within the working population there are two vulnerable groups: temporary agency workers and unemployed workers, since they have no workplace/employer to return to, when sick-listed. For this group there is a need for tailored RTW strategies and interventions. Therefore, this paper aims to describe the structured and stepwise process of development, implementation and evaluation of a theory- and practise-based participatory RTW program for temporary agency workers and unemployed workers, sick-listed due to musculoskeletal disorders (MSD). This program is based on the already developed and cost-effective RTW program for employees, sick-listed due to low back pain. METHODS: The Intervention Mapping (IM) protocol was used to develop a tailor-made RTW program for temporary agency workers and unemployed workers, sick-listed due to MSD. The Attitude-Social influence-self-Efficacy (ASE) model was used as a theoretical framework for determinants of behaviour regarding RTW of the sick-listed worker and development of the intervention. To ensure participation and facilitate successful adoption and implementation, important stakeholders were involved in all steps of program development and implementation. Results of semi-structured interviews and 'fine-tuning' meetings were used to design the final participatory RTW program. RESULTS: A structured stepwise RTW program was developed, aimed at making a consensus-based RTW implementation plan. The new program starts with identifying obstacles for RTW, followed by a brainstorm session in which the sick-listed worker and the labour expert of the Social Security Agency (SSA) formulate solutions/possibilities for suitable (therapeutic) work. This process is guided by an independent RTW coordinator to achieve consensus. Based on the resulting RTW implementation plan, to create an actual RTW perspective, a vocational rehabilitation agency is assigned to find a matching (therapeutic) workplace. The cost-effectiveness of this participatory RTW program will be evaluated in a randomised controlled trial. CONCLUSION: IM is a promising tool for the development of tailor-made OHC interventions for the vulnerable working populatio