Validation of Maximal Heart Rate Prediction Equations based on Sex and Physical Activity Status

International Journal of Exercise Science 8(4): 318-330, 2015. The purpose of the study was to determine if measured maximal heart rate (HRmax) was affected by sex or aerobic training status, and to determine the accuracy of three common clinical age-prediction maximal heart rate regression equations used to predict HRmax: HRmax = 220 – age, HRmax = 226 – age, and HRmax = 208 – (0.7 ∙ age). Fifty-two participants in total, 30 of which were in the active group (15 M, 15 F) and 22 subjects in the sedentary group (9 M, 13 F), within the age range of 18-25 years and with a normal BMI (18.5-24.9 kg∙m-2) underwent a Bruce maximal treadmill exercise protocol. The effect of sex and training status on HRmax was analyzed through a two-way ANOVA, and the effect of sex, aerobic training status, and regression equation on accuracy of the HRmax prediction was assessed with a three-way ANOVA (α=0.05). Overall, males had a higher HRmax than females (198.3 v. 190.4 beats • min-1 , p\u3c.001) and sedentary individuals had higher measured HRmax than active individuals (197.3 v. 191.4 beats • min-1, p=.002). Furthermore, HRmax = 208 – (0.7 ∙ age)(equation 3) calculated the smallest signed and unsigned residuals from the difference between observed HRmax and predicted HRmax values for the significant main effects of equation (3), equation x sex (females x 3), and equation x activity level (active x 3). Therefore, based on our results, we conclude that HRmax = 208 – (0.7 ∙ age) has greater accuracy than the other two equations studied for predicting observed values of HRmax in 18-25 year olds

General Guidelines for the Use of Colour on Electronic Charts

An Electronic Chart Testbed has been developed by the Canadian Hydrographic Service for the purposes of investigating design and safety aspects of using electronic charts as a navigational aid for mariners. The proper selection and specification of colour is a fundamental aspect of effective display design. This report outlines the issues involved in the use of colour on displays as they relate to the Electronic Chart Display and Information System (ECDIS). Topics include luminance, high and low ambient illumination, brigthness, display background, colour selection, information clutter, colour coding convention, stimulus size, image location, visual effects, and user characteristics. Since ECDIS is relatively young in its development, the purpose of the review is to provide some general guidelines for selecting and using colours on electronic charts

Incorporating Environmentally Compliant Manure Nutrient Disposal Costs into Least-Cost Livestock Ration Formulation

Livestock rations are formulated to minimize feed cost subject to nutritional requirements for a target performance level, which ignores the potentially substantial cost of disposing of nutrients fed in excess of nutritional requirements. We incorporate nutrient disposal costs into a modified least-cost ration formulation model to arrive at a joint least-cost decision that minimizes the sum of feed and net nutrient disposal costs. The method is demonstrated with phosphorus disposal costs on a representative dairy farm. Herd size, land availability and proximity, crop rotation, and initial soil phosphorus content are shown to be important in determining phosphorus disposal costs.environmental compliance, linear programming, livestock rations, manure disposal, Agribusiness, Environmental Economics and Policy, Livestock Production/Industries, C61, Q12, Q52,

Influence of Age and Gender on Indoor Rowing Performance

Physiological functional capacity is important in determining one’s ability to perform functional tasks and can be determined by studying peak exercise performance. Rowing is a unique sport requiring substantial muscle strength as well as high endurance capacity. Since it is a non-weight bearing activity, a number of older adults in general and older women in particular engage in this activity as they age. PURPOSE: To examine the relationship between aging, gender, and exercise task duration using indoor rowing performance records. METHODS: World records from indoor rowing events were analyzed and plotted against age (17-99 years of age) in both men and women. Rowing events included time trials in distance (e.g., 2000m race) and in time (e.g., 4 minutes race). To standardize these events, all of the performance data were converted to race speed prior to the data analyses. RESULTS: In both men and women, rowing performance declined linearly in all the duration events. The magnitudes of the age-related declines are mild to modest compared with other sporting events previously reported (e.g., running, weight lifting). For women, peak performance was observed in the 19-29 age group for 12 out of the 13 rowing events examined. For men, peak performance was recorded in the 30-39 age group for 8 out of 13 of the events, and in the remaining 5 events, the difference in performance times between the 19-29 and 30-39 age groups was less than 2%. When the data were expressed as a 50-yr decline in rowing performance from the 19-29 age group to the 70-79 age group, women had a greater decrease in performance in shorter sprinting events; however, as the events increased in distance requiring more endurance, the percent decline in performance were similar between men and women. CONCLUSION: The findings in this cross-sectional study indicate that physiological functional capacity as assessed by rowing performance declined linearly but mildly with advancing age, and the rate of age-associated decline is influenced greatly by gender and exercise task duration

Land Value Increments as a Measure of the Net Benefits of Urban Water Supply Projects in Developing Countries: Theory and Measurement

The subject of this paper is the extent to which the benefits of urban water supply projects are capitalized into land values. Its focus will be the theoretical conditions necessary for such capitalization in a developing country context. In a later section of the paper, we present a brief anatomy of the kind of empirical approach which seems appropriate to test this model

Genetic algorithm based design optimisation for permanent magnet synchronous motors

This research work presents a new and efficient design methodology for the specification, development and manufacture of permanent magnet synchronous motors (PMSMs). In this paper a genetic algorithm based design optimisation technique for PMSMs is presented in which the multicriteria considered in the optimisation are the electromagnetic performance, the thermal performance and the material cost. Models have been developed for each criterion in order to calculate the objective vector. A software tool called PMSM Analyser was developed to assist the motor design methodology. The optimisation algorithms and the electromagnetic, thermal and cost models were integrated and interfaced using this software. The programme is demonstrated for the design of a 12 slot 10 pole PMSM. The design parameter vector contains stator bore diameter, stator tooth thickness and stator back iron thickness. For the base design the outer diameter of the stator is 180mm and the stack length of the motor is 90mm. The base design refers to the design before optimisation and the optimal design refers to the design with optimised dimensions. The optimisation programme predicts significant improvements over the baseline design and experimental results are presented which indicate good agreement with the predictions of the programme. The new approach has been used successfully in the development and design of a PMSM with a stall torque of 125Nm, rated torque of 75Nm at 1500r/min and output power of 12kW. The strengths of the design methodology are summarised with the genetic algorithm optimisation, innovative multi-objective handling and design models for the various disciplines of PMSM development

Task Structure and the Propensity to Collaborate vs. Cooperate

Researchers have long studied the group dynamics of teams with the goal of making teams more effective. This study looks at the task structure to determine if groups are more likely to collaborate or cooperate to successfully complete a project. Initial findings indicate that the higher the structure of a project the more likely teams will gravitate to cooperation while the less structured the project the more likely teams are to work collaboratively. Initial findings indicate that the determination of the “structuredness” of a project is a subjective rather than objective assessment