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The use of standardized anthropomorphic test devices and test conditions prevent current vehicle development and safety assessments from capturing the breadth of variability inherent in real-world occupant responses. This study introduces a methodology that overcomes these limitations by enabling the assessment of occupant response while accounting for sources of human- and non-human-related variability. Although the methodology is generic in nature, this study explores the methodology in its application to human response in far-side motor vehicle crashes as an example. A total of 405 human body model simulations were conducted in a mid-sized sedan vehicle environment to iteratively train two neural networks to predict occupant head excursion and thoracic injury as a function of occupant anthropometry, impact direction and restraint configuration. The neural networks were utilized in Monte Carlo simulations to calculate the probability of head-to-intruding-door impacts and thoracic AIS 3+ as a function of the restraint configuration. This analysis indicated that the vehicle used in this study would lead to a range of 667 to 2,448 head-to-intruding-door impacts and a range of 3,041 to 3,857 cases of thoracic AIS 3+ in the real world, depending on the seatbelt load limiter. These real-world results were later successfully validated using United States field data. This far-side assessment illustrates how the methodology incorporates the human and non-human variability, generates response surfaces that characterize the effects of the variability, and ultimately permits vehicle design considerations and injury predictions appropriate for real-world field conditions.

Ergonomists measure height loss in relation to loads imposed on the spine. It is difficult to interpret whether height loss responses recorded on different days are accurate due to natural daily fluctuations in height loss and measurement variability. The objective of this research was to investigate whether the variability of height loss in the sitting position is affected by time of day and to analyse day-to-day variability in asymptomatic participants. Fifty asymptomatic participants attended two sessions (morning and afternoon) of stadiometry testing on four separate days. The results showed that a variability of height loss response changes in excess of 0.886 mm in morning and 1.128 mm in afternoon between days indicates that an intervention itself has influenced height loss. Future investigations on height loss in sitting should take theseresults into consideration to confidently state that an intervention has influenced height lossresponse at each time of day. Refereed/Peer-reviewed

Clopidogrel is widely prescribed in patients with cardiovascular disease. Most research has focused on the role of hepatic CYP450 metabolism as the primary source of response variability despite 85-90% of clopidogrel being hydrolyzed by human carboxylesterase-1 (CES1).The purpose of this study is to determine the effects of the known CES1 inhibitor alcohol on clopidogrel metabolism: (1)

This study examined relations between multiple measures of maternal iron status assessed 3 months post-partum, and infant processing speed (longest look during visual habituation), memory (novelty preference), attention (heart rate changes), and neural response variability (in auditory event-related potentials) at 3 and 9 months. Plasma iron was associated with 9-month novelty preference and longest look, and developmental changes in longest look. Hemoglobin predicted sustained attention, and both plasma iron and soluble transferrin receptors predicted neural response variability at 9 months. Improved maternal iron appears to have a positive impact on infant cognitive development even in a well-nourished, low-risk sample.

Operant response classes are customarily defined in terms of the function of the responses. The function is the effect on the environment which constitutes the contingencies of reinforcement that i...

The purpose of this study was to analyse the students’ evaluations of the course and instructor for all statistics courses offered during fall semester 2009 at a large university in the southern United States. Data were collected and analysed for course evaluations administered both online and on paper to students in both undergraduate and graduate courses. Unlike most previous studies on this subject, class section rather than student was treated as the unit of analysis. It was of specific interest to verify prior research findings that evaluation surveys administered online would not result in lower course and instructor ratings and lower response rates. The results showed that there is not sufficient evidence within the collected data to conclude that either course and instructor ratings or response rates are lower for evaluations administered online (online evaluations) than they are for evaluations administered on paper (paper evaluations). Of secondary interest was whether class ratings would be ass...

Nitrogen (N) fertilization has become a common practice in corn and wheat crops in the Argentine Pampas during the past decade. In this region, great environmental variability determines erratic responses to fertilization. The quantity of data necessary for defining yield response models to N has not been investigated, and the relative yield transformation, combined with the total nutrient approach, has been widespread when analyzing fertilizer response results. The objectives were to determine the minimum data set necessary for fitting average yield functions suitable for fertilizer recommendation at regional scale and to investigate the consequences of using relative yield on N response functions when the total nutrient approach is used. Published results from two extensive fertilization networks, one with corn and the other with wheat, were used. Data were aggregated at different levels, because one single experiment to the entire network results, and yield response functions to N were fitted. Yield models tended to stability when a set of around 100 or more data points, generated in experiments performed across different sites and years, were used for fitting models with both crops. This amount of data was generated by performing 20 experiments in the corn network and 35 in the wheat network. Relative yield transformation allowed us to obtain models with lower dispersion than yield, but in the case of corn a biased model was generated that leads to underestimating fertilizer requirements. In wheat, similar fertilizer recommendations were produced from yield or relative yield functions. Response variability to fertilization must be addressed in the experimental area by increasing the amount of data used, rather than by applying the relative yield transformation. Fil: Alvarez, Roberto. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina

The depth of focus (DOF) was measured and compared objectively in free space and subjectively in Badal optical space in 10 young adults. The mean total objective DOF was ±0.59 ±0.10 D, with a range from ±0.46 D to ±0.75 D. The mean total subjective DOF was ±0.63 ±0.22 D, with a range from ±0.37 D to ±0.96 D. The objective and subjective DOF values were not significantly different. However, response variability was greater [∼2×] in the subjective test mode. Similarity between the objective and subjective results suggests that blur plays a dominant role in this process, which is in agreement with earlier experiments and model predictions under normal closed-loop viewing conditions.

Toxicities of ten organophosphorus (OP) insecticides were measured against midge larvae (Chironomus riparius) under varying temperature (11, 18, and 25°C) and pH (6, 7, and 8) conditions and with and without sediment. Toxicity usually increased with increasing temperature and was greater in the absence of sediment. No trend was found with varying pH. A series of unidimensional parameters and multidimensional models were used to describe the changes in toxicity. Log K ow was able to explain about 40–60% of the variability in response data for aqueous exposures while molecular volume and aqueous solubility were less predictive. Likewise, the linear solvation energy relationship (LSER) model only explained 40–70% of the response variability, suggesting that factors other than solubility were most important for producing the observed response. Molecular connectivity was the most useful for describing the variability in the response. In the absence of sediment, 1χ v and 3κ were best able to describe t...

Timed ELISA is a protocol that enables quantitative ELISA without the aid of sophisticated laboratory equipment. It is likely be used outside of a temperature‐controlled environment and the response of this system to temperature is therefore significant. A model of Timed ELISA, based on the expected performance of its individual reactions, was able to predict the performance of the whole system between 15 and 25°C. Both the model and experimental results confirmed that Timed ELISA possessed an element of temperature compensation, although antigen standards were still required for accuracy. Interrogating the model with regards to a more thermostable conjugate and increased specific activity predicted that the latter would be most suited to extending the temperature range of this system.

A clinical group of children with attention deficit disorders with hyperactivity (ADD/H) was compared to a control group, each divided into high and low variability (HV and LV) on reaction time (RT) and movement time (MT) measures. The effects of tactile-somatosensory experience on performance was also investigated. Analyses of the HV and LV groups based on RT variability found improvement on MT in both HV groups (ADD/H and control) following a tactile-somatosensory task. Both HV groups based on MT variability also showed improvement in MT following the TPT administration. No LV group (based on either RT or MT) showed improvement in MT or RT. The results in this study indicated that HV (either RT or MT) predicted improved speed and accuracy following a tactile somatosensory task. Several neuroanatomical models for the study of response variability and the role of tactile somatosensory training programmes in paediatric rehabilitation are discussed.

(2003). Short CommunicationA new method of representing drug-induced platelet inhibition: better description of time course, response variability, non-response, and heightened reactivity. Platelets: Vol. 14, No. 7-8, pp. 481-483.

As compared with providing extrinsic feedback on each of a set of practice trials, reducing the feedback frequency in various ways facilitates long-term retention. One explanation is that frequent feedback operates proactively on the subsequent trial, inducing excessive variability that degrades learning. We tested this view by giving or not giving feedback "reminders," where the postresponse feedback was given again just before the next attempt at a task. The reminder manipulation was examined in both blocked and randomized practice sequences during the learning of three limb-patterning tasks. Reminder feedback increased response variability during practice in both random and blocked practice. As measured in retention tests, though, feedback reminders degraded learning in random practice, but not in blocked practice. This implies that the frequently found learning advantages of random, as compared with blocked, practice might be due to feedback's facilitation of retrieval operations in blocked practice (as well as in random practice with feedback reminders); such overfacilitation of retrieval operations has been shown to degrade learning. Additional analyses revealed that random, as compared with blocked, practice enhanced the learning of the fundamental pattern of action (generalized motor program) but had little effect on the ability to scale the pattern in amplitude or time (parameterization).

The comparison of primary interest in a 2 × 2 crossover trial typically concerns the effect of the treatments, say A and B, on the mean response level. This article deals with another important aspect, namely the within-subject response variability under A and B. Differences in drug formulation and/or administration may lead to considerable differences in within-subject variability, whatever the difference in terms of mean level. Consideration of both these aspects may, therefore, be of considerable importance for the judgement of the treatments. It is shown that although there are no within-subject treatment replications, it is possible to make various exact inferences about the A/B ratio of within-subject variances and about the (A – B)-difference in mean level, simultaneously and marginally. These inferences are semiparametric in that no distributional assumption is made about the between-subject variability, whereas a normality assumption is used for the within-subject variability. The infere...

Soil test interpretation, the process of developing fertilizer application recommendations from soil test levels and other soil, crop and climatic conditions, is a commonly used but poorly understood procedure. This paper discusses the shapes of curves that represent yield response to applied nutrients and investigates the perception that the most common shape is curvilinear. A common set of data is used to compare the fertilizer recommendations made using the Mitscherlich‐Bray, yield response and plateau yield point methods of soil test interpretation.

Older females consistently demonstrate larger PREP amplitudes than males and there is some consensus that CNS dimorphism does not explain the magnitude of this gender difference. Comparison of gender differences for visually evoked responses to patterned and nonpatterned stimuli suggest that females may have enhanced visual system responsivity to increases in spatial frequencies. PREP amplitude may also be influenced by single trial response variability. Potential contributions of this factor to PREP gender differences have not been investigated. This study evaluated the contributions of check size and single trial response variability to gender differences in PREP amplitudes. For 21 males and 21 females aged 61–75 years, no gender differences in visual acuity, critical flicker fusion threshold, or PREP component latency were observed. Females had larger amplitude PREPs than males, and had a larger differential response to small (15') and large (30') check sizes. Single trial response variability...

Dispersion main effects and two-factor interactions are first defined and then estimated in replicated factorial experiments. A method based on Union-Intersection rules, using dispersion main effects and two factor interactions is proposed for finding the level combinations of control factors so that the response variability due to noise is minimum. Illustrative examples are also given.

Measurements of 8-hr time-weighted average (TWA) exposures are subject to environmental variability and collection and analytical error. Environmental variability can be represented by the geometric standard deviation (GSD) of the lognormally distributed 8-hr TWAs; analytical variability can be represented by the coefficient of variation (CV) of the normally distributed collection and analytical errors. A mathematical expression is derived for the variance of the measured 8-hr TWAs as a function of the GSD of the true daily average exposures and the total CV of the industrial hygiene method used in monitoring. For typical values of the GSD and CV, environmental variability is far more important than analytical variability in determining the variance of the measured 8-hr TWAs. A resulting policy implication is that the Occupational Safety and Health Administration inappropriately focuses on analytical variability when determining compliance with its permissible exposure limits.

Six sunflower (Helianthus annuus L.) lines were grown in nutrient solution to characterize their sensitivity to bicarbonate‐induced Fe chlorosis. Sensitivity was evaluated by chlorosis score and growth reduction relative to the control without added bicarbonate. Chlorosis score was inversely correlated to chlorophyll and Fe concentrations in the uppermost leaves. This technique seems valuable for determining genotypic differences in sensitivity to Fe‐induced chlorosis in sunflower. Bicarbonate treatment resulted in an increase in the Ca, Mg, K and Mn and in a decrease in the Fe and P concentrations in leaves. In roots, bicarbonate treatment resulted in a decrease in the Fe and Mn concentrations. Some of the effects of bicarbonate on these elemental compositions were related to the degree of chlorosis.

The purpose of the present study was to compare the power of three subject variables as predictors of performance in a skin temperature biofeedback task. Data from three related experiments (N = 52) designed to train digital skin temperature increases in four sessions were pooled. Three measures (mean skin temperature, standard deviation and standard error of estimate), derived from a prefeedback instructional control session, were correlated with three criteria derived from training sessions (temperature change in the first, last and mean of training sessions). There were significant correlations with standard error of estimate, the largest with the mean change measure, accounting for 14% of temperature variance. The findings are consistent with an operant conditioning model of biofeedback learning, and have implications for more optimal training methods and experimental designs based on assessment of the standard error of estimate.

Changing the nature of a motor response can produce a reliable change in choice reaction time, while the corresponding effect for simple reaction time is unreliable, and disappears with appropriate instructions and practice. The reliable effect for choice reactions was attributed to a component of the reaction time in which the response is programmed. This programming can be done in advance of the simple reaction-time interval thereby eliminating this component from the measured simple reaction time, although S may not necessarily take advantage of this possibility. According to this analysis, the Henry and Rogers "memory drum theory(") applies to choice reactions but not necessarily to the simple reactions which have been the primary basis for previous demonstrations.

Data were collected on 60 subjects using a two-treatment, repeated measure design for a blind tracing task and analyzed using various statistical models. The results indicated that appropriate models for estimating the intraindividual response variability included the standard deviation of all trials for each subject, the average of each individual's standard deviation, the adjacent trials correlation coefficient model for repeated trials, and the intraclass reliability for obtained scores model for ANOVA designs. The latter model provides a single score estimate of variability which may be used in interstudy comparisons.

The measurement of flows in the American labor market has challenged researchers for years. Several problems, including response variability, rotation group bias, and matching errors, hinder accurate measurement of the flows. The Bureau of the Census and the Bureau of Labor Statistics jointly sponsored a conference to examine these problems, present current research on solutions to the problems, and submit recommendations for improving the data. Recommendations include procedural changes in the Current Population Survey as well as new estimation techniques.

Phytohemagglutinin (PHA)-induced lymphocyte blastogenesls was used as an in vitro test for the immunocompetence of circulating thymus-dependent (T) lymphocytes. The data accumulated from a pool of normal individuals showed a wide range of responses and are presented here. The response variability is a function of time-dependent variations within individuals at high PHA concentrations. At low PHA concentrations, there is large variability of response within individuals as a function of time as well as large variability in mean responses between individuals. A non-Gaussian frequency distribution of responses is also obtained at low PHA concentration. The frequency distribution of responses observed does not appear to be strongly dependent upon the age distribution of the normals.

(1989). Identifying the Random Responder. The Journal of Psychology: Vol. 123, No. 1, pp. 101-103.

Summary The stability of TAT ambiguity values, based either on interjudge, or intrajudge response variability, was investigated. Interjudge variability was estimated from dispersion of the first response emitted to each stimulus; intrajudge variability utilized multiple associations by Ss. Multiple association yielded highly stable values in comparisons over time, and neither method resulted in stability across S samples. It was concluded that the definition of ambiguity must include intrajudge variability in order to achieve a reliable ordering of stimuli for a given respondent.