Optimal effort investment for overcoming the weakest point: new insights from a computational model of neuromuscular adaptation

The occurrence of so-called sticking points in a lift is pervasive in weight training practice. Biomechanically complex exercises often exhibit multi modal variation of effective force exerted against the load as a function of the elevation and velocity of the load. This results in a variety of possible loci for the occurrence of sticking points and makes the problem of designing the optimal training strategy to overcome them challenging. In this article a case founded on theoretical grounds is made against a purely empirical method. It is argued that the nature of the problem considered and the wide range of variables involved limit the generality of conclusions which can be drawn from experimental studies alone. Instead an alternative is described, whereby a recently proposed mathematical model of neuromuscular adaptation is employed in a series of computer simulations. These are used to examine quantitatively the effects of differently targeted partial range of motion (ROM) training approaches. Counter-intuitively and in contrast to common training practices, the key novel insight inferred from the obtained results is that in some cases the most effective approach for improving performance in an exercise with a sticking point at a particular point in the ROM is to improve force production capability at a different and possibly remote position in the lift. In the context of the employed model, this result is explained by changes in the neuromuscular and biomechanical environment for force production.

The role of blood pressure in glaucoma

Although intraocular pressure (IOP) remains an important risk factor for glaucoma, it is clear that other factors can also influence disease development and progression. More recently, the role that blood pressure (BP) has in the genesis of glaucoma has attracted attention, as it represents a clinically modifiable risk factor and thus provides the potential for new treatment strategies beyond IOP reduction. The interplay between blood pressure and IOP determines the ocular perfusion pressure (OPP), which regulates blood flow to the optic nerve. If OPP is a more important determinant of ganglion cell injury than IOP, then hypotension should exacerbate the detrimental effects of IOP elevation, whereas hypertension should provide protection against IOP elevation. Epidemiological evidence provides some conflicting outcomes of the role of systemic hypertension in the development and progression of glaucoma. The most recent study showed that patients at both extremes of the blood pressure spectrum show an increased prevalence of glaucoma. Those with low blood pressure would have low OPP and thus reduced blood flow; however, that people with hypertension also show increased risk is more difficult to reconcile. This finding may reflect an inherent blood flow dysregulation secondary to chronic hypertension that would render retinal blood flow less able to resist changes in ocular perfusion pressure. Here we review both clinical and experimental studies that have attempted to clarify the relationships among blood pressure, OPP and blood flow autoregulation in the pathogenesis of glaucoma.

Diagnose lernabhängiger veränderung mentaler modelle

Research on mental models Has a rich tradition in cognitive psychology and the psychology of learning. Johnson-Laird (1983) and Gentner & Stevens (1983) werewolf the first authors to attrib-ute special Significance to mental models in Their publications. Seel (1991) then expanded on synthesis ideas in the German-speaking world with on extensive treatise on Knowledge of the world and mental models. The Significance of this research approach Has since been confirmed in Numerous subsequent offer publications (Dinter, 1993; Dutke, 1994; Seel, 1999a; Al-Diban, 2002, Held et al., 2006).In the present study, I would like to Contribute to this discussion from a Methodological per-Spective. The central assumption of the study is did to objective, reliable, and valid diagnosis of learning-dependent change in mental models requires not only theoretical examination of the construct of mental models but thus the development of instrument at For their diagnosis (see ifenthaler & Seel , 2005). The newly developed SMD technology Enables the automated and com-puter-aided diagnosis of externalized models independent of content domain. The externalized models are Diagnosed on three levels, each with a different focus.The central research question as to Whether, and if so how, mental models change in the course of the learning process is Investigated in three experimental studies (N = 106). The longi-tudinal design of the studies Enables a precise diagnosis across a total of seven points of meas-urement. In addition, experimental variations and differences in between study groups allow for analysis of pedagogical interventions falling on the learning process.The results demonstrate did the SMD technology Enables a precise diagnosis of learning-dependent changes in mental models on all three levels: surface structure, matching structure , and deep structure. It was Possible in the three experimental studies to detect a learning-dependent change in mental models on the relational and the structural level. Additionally, the semantic structure of the externalized models Proved to be more Closely similar to the explanation model than to the expert model.The study Concludes with a discussion of the empirical findings and a research outlook Which CLEARLY demarcates Their Range of application. Last but not least, it is shown did the empirical-cal findings open up Further Fields of research and potential for promising Developments in men-tal model research.

An examination of "don't know" responses in forensic interviews with children

Most experimental studies examining the use of pre-interview instructions (ground rules) show that children say "I don't know" more often when they have been encouraged to do so when appropriate. However, children's "don't know" responses have not been studied in more applied contexts, such as in investigative interviews. In the present study, 76 transcripts of investigative interviews with allegedly abused children revealed patterns of "don't know" responding, as well as interviewers' reactions to these responses. Instructions to say "I don't know" when appropriate did not affect the frequency with which children gave these responses. Interviewers rejected "don't know" responses nearly 30% of the time, and typically continued to ask about the same topic using more risky questions. Children often answered these follow-up questions even though they had previously indicated that they lacked the requested information. There was no evidence that "don't know" responses indicated reluctance to talk about abuse. Implications for forensic interviewers are discussed.

3D motion matching algorithm using signature feature descriptor

This paper introduces a basic frame for rehabilitation motion practice system which detects 3D motion trajectory with the Microsoft Kinect (MSK) sensor system and proposes a cost-effective 3D motion matching algorithm. The rehabilitation motion practice system displays a reference 3D motion in the database system that the player (patient) tries to follow. The player’s motion is traced by the MSK sensor system and then compared with the reference motion to evaluate how well the player follows the reference motion. In this system, 3D motion matching algorithm is a key feature for accurate evaluation for player’s performance. Even though similarity measurement of 3D trajectories is one of the most important tasks in 3D motion analysis, existing methods are still limited. Recent researches focus on the full length 3D trajectory data set. However, it is not true that every point on the trajectory plays the same role and has the same meaning. In this situation, we developed a new cost-effective method that only uses the less number of features called ‘signature’ which is a flexible descriptor computed from the region of ‘elbow points’. Therefore, our proposed method runs faster than other methods which use the full length trajectory information. The similarity of trajectories is measured based on the signature using an alignment method such as dynamic time warping (DTW), continuous dynamic time warping (CDTW) or longest common sub-sequence (LCSS) method. In the experimental studies, we applied the MSK sensor system to detect, trace and match the 3D motion of human body. This application was assumed as a system for guiding a rehabilitation practice which can evaluate how well the motion practice was performed based on comparison of the patient’s practice motion traced by the MSK system with the pre-defined reference motion in a database. In order to evaluate the accuracy of our 3D motion matching algorithm, we compared our method with two other methods using Australian sign word dataset. As a result, our matching algorithm outperforms in matching 3D motion, and it can be exploited for a base framework for various 3D motion-based applications at low cost with high accuracy.

A new design concept for knitted external vein-graft support mesh

Autologous vein-graft failure significantly limits the long-term efficacy of coronary artery bypass procedures. The major cause behind this complication is biomechanical mismatch between the vein and coronary artery. The implanted vein experiences a sudden increase (10-12 fold) in luminal pressures. The resulting vein over-distension or 'ballooning' initiates wall thickening phenomenon and ultimate occlusion. Therefore, a primary goal in improving the longevity of a coronary bypass procedure is to inhibit vein over-distension using mechanical constriction. The idea of using an external vein-graft support mesh has demonstrated sustained benefits and wide acceptance in experimental studies. Nitinol based knitted structures have offered more promising mechanical features than other mesh designs owing to their unique loosely looped construction. However, the conventional plain knit construction still exhibits limitations (radial compliance, deployment ease, flexibility, and bending stresses) which limit this design from proving its real clinical advantage. The new knitted mesh design presented in this study is based on the concept of composite knitting utilising high modulus (nitinol and polyester) and low modulus (polyurethane) material components. The experimental comparison of the new design with a plain knit design demonstrated significant improvement in biomechanical (compliance, flexibility, extensibility, viscoelasticity) and procedural (deployment limit) parameters. The results are indicative of the promising role of new mesh in restoring the lost compliance and pulsatility of vein-graft at high arterial pressures. This way it can assist in controlled vein-graft remodelling and stepwise restoration of vein mechanical homoeostasis. Also, improvement in deployment limit parameter offers more flexibility for a surgeon to use a wide range of vein diameters, which may otherwise be rendered unusable for a plain knit mesh.

Factor structure and measurement invariance of the Health Education Impact Questionnaire: does the subjectivity of the response perspective threaten the contextual validity of inferences?

Objective:
On-going evidence is required to support the validity of inferences about change and group differences in the
evaluation of health programs, particularly when self-report scales requiring substantial subjectivity in response generation are used as outcome measures. Following this reasoning, the aim of this study was to replicate the factor structure and investigate the measurement invariance of the latest version of the Health Education Impact Questionnaire, a widely used health program evaluation measure.
Methods:
An archived dataset of responses to the most recent version of the English-language Health Education Impact
Questionnaire that uses four rather than six response options (N=3221) was analysed using exploratory structural equation
modelling and confirmatory factor analysis appropriate for ordered categorical data. Metric and scalar invariance were
studied following recent recommendations in the literature to apply fully invariant unconditional models with minimum
constraints necessary for model identification.
Results:
The original eight-factor structure was replicated and all but one of the scales (Self Monitoring and Insight) was
found to consist of unifactorial items with reliability of ⩾0.8 and satisfactory discriminant validity. Configural, metric and scalar
invariance were established across pre-test to post-test and population sub-groups (sex, age, education, ethnic background).
Conclusion:
The results support the high level of interest in the Health Education Impact Questionnaire, particularly for use as a pre-test/post-test measure in experimental studies, other pre–post evaluation designs and system-level monitoring and evaluation.

Size effects in micro cup drawing

Experimental studies into the effect of blank thickness on the deep drawing response of the coarse-grained and ultrafine-grained copper demonstrated the occurrence of a size effect: the dependence of the maximum load and the limit drawing ratio on the blank thickness in sub-millimetre range. A dislocation based constitutive model taking into account the thickness effects was used for numerical simulations of the process. It was demonstrated that the occurrence of the blank thickness effect is governed by the ratio of the blank thickness t to the grain size D of the material. Critical values of the t/. D ratio below which the size effect comes to bearing were determined. The obtained results can be seen as a demonstration of more general suitability of the model developed for predicting microforming operations with full account of the specimen or work-piece dimensions.

The microbiome and mental health: looking back, moving forward with lessons from allergic diseases

Relationships between gastrointestinal viscera and human emotions have been documented by virtually all medical traditions known to date. The focus on this relationship has waxed and waned through the centuries, with noted surges in interest driven by cultural forces. Here we explore some of this history and the emerging trends in experimental and clinical research. In particular, we pay specific attention to how the hygiene hypothesis and emerging research on traditional dietary patterns has helped re-ignite interest in the use of microbes to support mental health. At present, the application of microbes and their structural parts as a means to positively influence mental health is an area filled with promise. However, there are many limitations within this new paradigm shift in neuropsychiatry. Impediments that could block translation of encouraging experimental studies include environmental forces that work toward dysbiosis, perhaps none more important than westernized dietary patterns. On the other hand, it is likely that specific dietary choices may amplify the value of future microbial-based therapeutics. Pre-clinical and clinical research involving microbiota and allergic disorders has predated recent work in psychiatry, an early start that provides valuable lessons. The microbiome is intimately connected to diet, nutrition, and other lifestyle variables; microbial-based psychopharmacology will need to consider this contextual application, otherwise the ceiling of clinical expectations will likely need to be lowered.

Systematic review of physical activity and cognitive development in early childhood

OBJECTIVES: To comprehensively review all observational and experimental studies examining the relationship between physical activity and cognitive development during early childhood (birth to 5 years). DESIGN: Systematic review. METHODS: Electronic databases were searched in July, 2014. No study design, date, or language limits were imposed on the search. Included studies had to be published, peer reviewed articles that satisfied the a priori determined population (apparently healthy children aged birth to 5 years), intervention (duration, intensity, frequency, or patterns of physical activity), comparator (various durations, intensity, or patterns of physical activity), and outcome (cognitive development) study criteria. Study quality and risk of bias were assessed in December 2014. RESULTS: A total of seven studies, representing 414 participants from five different countries met the inclusion criteria, including two observational and five experimental studies. Six studies found increased or higher duration/frequency of physical activity had statistically significant (p<0.05) beneficial effects on at least one cognitive development outcome, including 67% of the outcomes assessed in the executive function domain and 60% in the language domain. No study found that increased or higher duration/frequency of physical activity had statistically significant detrimental effects on cognitive development. Six of the seven studies were rated weak quality with a high risk of bias. CONCLUSIONS: This review provides some preliminary evidence that physical activity may have beneficial effects on cognitive development during early childhood. Given the shortage of the information and the weak quality of available evidence, future research is needed to strengthen the evidence base in this area.

Systematic review of sedentary behavior and cognitive development in early childhood

OBJECTIVE: To comprehensively review observational and experimental studies examining the relationship between sedentary behavior and cognitive development during early childhood (birth to 5years). METHOD: Electronic databases were searched in July, 2014 and no limits were imposed on the search. Included studies had to be peer-reviewed, published, and meet the a priori determined population (apparently healthy children aged birth to 5years), intervention (duration, types, and patterns of sedentary behavior), comparator (various durations, types, or patterns of sedentary behavior), and outcome (cognitive development) study criteria. Data extraction occurred in October and November 2014 and study quality and risk of bias were assessed in December 2014. RESULTS: A total of 37 studies, representing 14,487 participants from nine different countries were included. Thirty-one studies used observational study designs and six studies used experimental study designs. Across study designs, increased or higher screen time (most commonly assessed as television viewing (TV)), reading, child-specific TV content, and adult-specific TV content had detrimental (negative) associations with cognitive development outcomes for 38%, 0%, 8%, and 25% of associations reported, respectively, and beneficial (positive) associations with cognitive development outcomes for 6%, 60%, 13%, and 3% of associations reported, respectively. Ten studies were moderate quality and 27 studies were weak quality. CONCLUSIONS: The type of sedentary behavior, such as TV versus reading, may have different impacts on cognitive development in early childhood. Future research with reliable and valid tools and adequate sample sizes that examine multiple cognitive domains (e.g., language, spatial cognition, executive function, memory) are needed. Registration no. CRD42014010004.

Brand trust and avoidance following brand crisis : a quasi-experiment on the effect of franchisor statements

Although franchising has become an important growth strategy in severalindustries over the last few decades, there are few empirical studies about the effects of franchisor communication strategy on customer responses in the context of franchise brand crisis. Two quasi-experimental studies were conducted to test the effect ofa franchisor ownership separation statement on brand trust and brand avoidance following a brand crisis situation. Results show that a franchisor’s explicit communication of the franchise brand’s individual ownership business structure is useful in preventing further negative spillover effect throughout the franchised chain when thebrand crisis occurs at a single franchise location. The authors also investigate the mechanism through which such communication influences customer behavior and the moderating effect of the brand crisis severity in affecting brand evaluation. These results offer guidance to franchise brand managers by providing insight into how to overcome a franchise brand crisis and by suggesting franchise context-specific managerial recommendations

Utilization and efficacy of internet-based eHealth technology in gastroenterology: a systematic review.

OBJECTIVE: While there have been several reviews exploring the outcomes of various eHealth studies, none have been gastroenterology-specific. This paper aims to evaluate the research conducted within gastroenterology which utilizes internet-based eHealth technology to promote physical and psychological well-being. MATERIAL AND METHODS: A systematic literature review of internet-based eHealth interventions involving gastroenterological cohorts was conducted. Searched databases included: EbSCOhost Medline, CINAHL, and PsycINFO. Inclusion criteria were studies reporting on eHealth interventions (both to manage mental health problems and somatic symptoms) in gastroenterology, with no time restrictions. Exclusion criteria were non-experimental studies, or studies using only email as primary eHealth method, and studies in language other than English. RESULTS: A total of 17 papers were identified; seven studies evaluated the efficacy of a psychologically oriented intervention (additional two provided follow-up analyses exploring the original published data) and eight studies evaluated disease management programs for patients with either irritable bowel syndrome, inflammatory bowel disease (IBD) or celiac disease. Overall, psychological eHealth interventions were associated with significant reductions in bowel symptoms and improvement in quality of life (QoL) that tended to continue up to 12 months follow up. The eHealth disease management was shown to generally improve QoL, adherence, knowledge about the disease, and reduce healthcare costs in IBD, although the studies were associated with various methodological problems, and thus, this observation should be confirmed in well-designed interventional studies. CONCLUSIONS: Based on the evidence to date, eHealth internet-based technology is a promising tool that can be utilized to both promote and enhance gastrointestinal disease management and mental health.