A technique for assessment of torso kinesiology

A technique is described for monitoring and analysis of the angular displacement of the human torso. The technique is based on the use of miniature electromechanical inclinometers and video recording. The system was developed for continuous measurement of the angular displacement of spinal segments in the sagittal plane during all stages of lifting. Angular displacements of the cervical, thoracic and lumbar regions were obtained from a dynamic lifting case study using a digital processing system. The geometrical changes of the torso during five prescribed stages were measured. The system revealed good accuracy with high correlation coefficient scores for a wide range of lifting tasks in a comparative laboratory study. This paper describes the monitoring technique; the system's advantages, disadvantages and measuring accuracy are discussed.     

Cyanobacterial blooms in the central basin of Lake Erie: Potentials for cyanotoxins and environmental drivers

Lake Erie western basin (WB) cyanobacterial blooms are a yearly summer occurrence; however, blooms have also been reported in the offshore waters of the central basin (CB), and very little is known about what drives these blooms or their potential for cyanobacterial toxins. Cyanobacteria Index was quantified using MODIS and MERIS data for the CB between 2003 and 2017, and water samples were collected between 2013 and 2017. The goals were to 1) quantify cyanobacteria, 2) determine environmental drivers of CB blooms, and 3) determine the potential for cyanobacterial toxins in the CB. Dolichospermum (Anabaena) occurred in the CB during July before the onset of the WB bloom, and then in August and September, the cyanobacteria community shifted towards Microcystis. The largest Dolichospermum blooms (2003, 2012, 2013, and 2015) were associated with reduced water clarity (Secchi disk depth?<?4?m), whereas large CB Microcystis blooms (2011 and 2015) were associated with large WB blooms. Dolichospermum blooms occurred in high nitrate concentrations (>20?μmol/L) and high nitrogen-to?phosphorus ratios (>100), which indicate nutrient concentrations or ratios did not select for Dolichospermum. Additionally, the sxtA gene, but not mcyE or microcystins, were detected in the CB during July 2016 and 2017. The mcyE gene and microcystins were detected in the CB during August 2016 and 2017. The results indicate the CB's potential for cyanotoxins shifts from saxitoxins to microcystins throughout the summer. Continued monitoring of cyanobacteria and multiple cyanobacterial toxins is recommended to ensure safe drinking water for CB coastal communities.     

A three-dimensional dynamic posture prediction model for simulating in-vehicle seated reaching movements: development and validation

A three-dimensional dynamic posture prediction model for simulating in-vehicle seated reaching movements is presented. The model employs a four-segment 7-degrees-of-freedom linkage structure to represent the torso, clavicle and right upper extremity. It relies on an optimization-based differential inverse kinematics approach to estimate a set of four weighting parameters that quantify a time-constant, inter-segment motion apportionment strategy. In the development phase, 100 seated reaching movements performed by 10 subjects towards five typical in-vehicle targets were modelled, resulting in 100 sets of weighting parameters. Statistical analysis was then conducted to relate these parameters to target and individual attributes. In the validation phase, the generalized model, with parameter values statistically synthesized, was applied to novel data sets containing 700 different reaching movements (towards different targets and/or by different subjects). The results demonstrated the model's ability to generate close representations in prediction: the overall mean time-averaged error in joint angle was 5.2 degrees, and the median was 4.7 degrees, excluding reaches towards two extreme targets (for which modelling errors were excessive). The model's general success in prediction and its unique characteristics led to implications with regard to the performance and underlying control strategies of human reaching movements.     

A Biomechanical Evaluation of Two Methods of Manual Load Lifting

Since the middle 1930's it has been advocated that all lifting should be carried out with the back near vertical and with the knees bent. The basis for this recommendation has been that it shifts the stresses on the body from the low-back to the legs. Under certain conditions this recommendation is invalid. In this paper Chaffin and Baker's biomechanical lifting model is extended by considering the erector spinae muscles and by considering load accelerations. Mathematical modeling shows that forces on the erector spinae muscles and the lumbosacral disc can be as much as 50% higher when using the recommended “straight back, bent knees” method when compared to the common “stooped back” method. The straight back method is recommended only for lifts when the object is initially close to the spine.     

Toward memory-based human motion simulation: development and validation of a motion modification algorithm

Computer simulation of human motions helps test hypotheses on human motion planning and fosters timely and high-quality human-machine/environment interaction design. The current study introduces a novel simulation approach termed memory-based motion simulation (MBMS), and presents its key element "motion modification" (MoM) algorithm. The proposed approach implements a computational model inspired by the generalized motor program (GMP) theory. Operationally, when a novel motion scenario is submitted to the MBMS system, its motion database is searched to find relevant existing motions. The selected motions, referred to as "root motions", most likely do not meet exactly the novel motion scenario, and therefore, they need to be modified by the MoM algorithm. This algorithm derives a parametric representation of possible variants of a root motion in a GMP-like manner, and adjusts the parameter values such that the new modified motion satisfies the novel motion scenario, while retaining the root motion's overall angular movement pattern and inter-joint coordination. An evaluation of the prediction capability of the algorithm, using both seated upper body reaching and whole-body load-transfer motions, indicated that the algorithm can accurately predict various human motions with errors comparable to the inherent variability in human motions when repeated under identical task conditions.     

Randomized controlled trial of effects of Escherichia coli antiserum on serum immunoglobulin G concentrations and morbidity and mortality rates in foals

OBJECTIVE: To determine whether administration of commercially available Escherichia coli antiserum to neonatal foals would affect serum IgG concentration or morbidity and mortality rates during the first 60 days of life. DESIGN: Randomized controlled trial. ANIMALS: 271 neonatal foals on 4 well-managed farms. PROCEDURE: Foals were randomly assigned to a treatment or control group. All foals were allowed to suckle colostrum normally. In addition, treatment-group foals were given E coli antiserum (10 micromilligrams) orally between 0 and 8 hours after birth. Serum samples were obtained between 18 and 36 hours after birth, and serum IgG concentration was determined. Foals were monitored for the first 60 days after birth, and causes of disease or death were recorded. RESULTS: Groups did not differ significantly in regard to breed, sex, month of birth, season of birth, age of dams, parity of dams, duration of gestation, or specific gravity of colostrum before suckling. In addition, groups did not differ significantly in regard to mean serum IgG concentration, prevalence of complete or partial failure of passive transfer of immunity, frequency or causes of disease, or frequency of death from infectious causes. CLINICAL IMPLICATIONS: In this group of foals on well-managed farms, administration of E coli antiserum did not alter serum IgG concentrations or morbidity and mortality rates during the first 60 days of life.     

THE EFFECT OF ASPHALT COMPOSITION ON THE FORMATION OF ASPHALTENES AND THEIR CONTRIBUTION TO ASPHALT VISCOSITY

Interactions among asphalt components have significant effects on the performance of asphalt binder. To understand those interactions, four asphalts, SHRP AAA-I, AAD-I, AAF-I, and AAG-I, were fractionated into three generic fractions according to Corbett's procedure and reblended into asphaltenes/aromatics/saturates ternary mixtures in various ratios. Mixtures were oxidatively aged with atmospheric air at temperatures of 87.7, 93.3, and 98.8°C for 5 to 33 days. The changes in chemical composition and physical properties were monitored using fourier transform infrared spectroscopy (FT-IR) and dynamic mechanical rheometry

The formation of asphaltenes is a major factor in the hardening of asphalt with aging. The data collected in this study indicate that the saturate content in the maltene phase has a profound impact on the contribution that asphaltenes have on the viscosity of aged asphalt. The data also suggest that the aromatics fraction is solely responsible for the formation of asphaltenes as an asphalt oxidizes.     

Effect of handle height on lower-back loading in cart pushing and pulling

This paper presents results of a study conducted to estimate lower back loadings in cart pushing and pulling. Experiments were conducted in the laboratory using a cart. Six subjects with different weights (ranging from 50 to 80 kg) were tested for three different pushing and pulling forces (98, 196 and 294 newtons), three different heights of exertion (660, 1090 and 1520 mm high) and two different moving speeds (1.8 and 3.6 km/h). It was found that, in general, pushing a cart results in lesser lower-back loading than pulling. Subject body weight affected the lower-back loadings more significantly in pulling (50% increase as body weight increased from 50 kg to 80 kg) than in pushing (25% increase). Handle height of 1090 mm was found to be better than other handle heights in pushing while 1520 mm handle height was better for pulling in reducing lower-back loadings.