Foot pedal operated fluid type exercising device

A foot pedal operated exercising device is reported that contains a dynamometer formed of a pair of cylinders each containing a piston. The pistons are linked to each other. The upper portions of the two cylinders are joined together by a common opening to provide a common fluid reservoir and each piston is provided with a one way check valve to maintain an adequate supply of working fluid. Fluid from the driven cylinder is transmitted to the other cylinder through separate constant force spring biased valves each valve takes the predominant portion of the pressure drop thereby providing a constant force hydraulic dynamometer. A device is provided to determine the amount of movement of piston travel

Nonlinear bubble dynamics

The standard approach to the analysis of the pulsations of a driven gas bubble is to assume that the pressure within the bubble follows a polytropic relation of the form p=p0(R0/R)3?, where p is the pressure within the bubble, R is the radius, ? is the polytropic exponent, and the subscript zero indicates equilibrium values. For nonlinear oscillations of the gas bubble, however, this approximation has several limitations and needs to be reconsidered. A new formulation of the dynamics of bubble oscillations is presented in which the internal pressure is obtained numerically and the polytropic approximation is no longer required. Several comparisons are given of the two formulations, which describe in some detail the limitations of the polytropic approximation

A Total-System View of Environmental Management

Man, vastly increasing in number and continuing to exploit his natural resources, has altered the quality of his environment until it is in danger of becoming unfit for human life. The reversal of this trend must begin with the formulation of a management system that encompasses the total cycle of man\u27s environmental manipulation — from the extraction of raw materials and the production of goods to the eventual disposal of those goods. This paper describes how environmental quality can be managed on a large scale and outlines the methods for implementing this management through the total-system approach

Motor Carrier Scheduling Practices and Their Influence on Driver Fatigue

The primary objective of this report is to develop a better understanding of how the scheduling practices of motor carrier firms affect driver fatigue. The basis of this empirical research is a commercial driver fatigue model that includes driving environment (i.e., regularity of time, trip control, and quality of rest), economic pressures exerted on drivers (from customers, carriers, and the drivers themselves) and company safety practices as key factors in explaining driver fatigue. The model utilizes two measures of fatigue: frequency of close calls due to fatigue and driver perceptions of fatigue as a problem. Crash involvement is used to evaluate general safety performance. Three separate studies were conducted. First, the influence of driving environments alone on fatigue among over-the-road truck drivers was tested through a survey of 502 drivers at five geographically dispersed truck stops. A typology of driving environments was developed and the percent of drivers in each category was determined. It was found that a large number of drivers are in the “high fatigue risk” categories. Regression analysis identified starting the work week tired and longer than expected loading and unloading time as significantly related to both measures of fatigue. Regularity of time, regularity of route, and hours of uninterrupted sleep were each statistically significant factors for one fatigue measure. Next, the complete model was tested on a random sample of 279 drivers at 116 trucking companies and 122 drivers at 66 motor coach companies, which was then stratified on the basis of safety performance (i.e., SAFESTAT ratings). Data for these two studies were generated from surveys of drivers, safety directors, dispatchers, and top management at the sample firms. In the truck company study, starting the workweek tired was the single most significant factor related to fatigue. Other significant fatigue-influencing factors were difficulty in finding a place to rest and shippers’ and receivers’ scheduling requirements (including loading and unloading). Company safety practices that mitigated driver fatigue were carrier assistance with loading and unloading, carrier efforts to minimize nighttime driving, and driver voluntary attendance at corporate safety and training meetings. In the motor coach company study, the most significant factors related to driver fatigue were starting the work week tired, driving tired to make a good income, and pressure on drivers to accept trips. Two safety measures – drivers’ perceptions of their company’s safe drivingculture and policies, or attempts to minimize nighttime driving – mitigated some of the factors that adversely affect driver fatigue

Adaptive Appraisals of Anxiety Moderate the Association between Cortisol Reactivity and Performance in Salary Negotiations

Prior research suggests that stress can be harmful in high-stakes contexts such as negotiations. However, few studies actually measure stress physiologically during negotiations, nor do studies offer interventions to combat the potential negative effects of heightened physiological responses in negotiation contexts. In the current research, we offer evidence that the negative effects of cortisol increases on negotiation performance can be reduced through a reappraisal of anxiety manipulation. We experimentally induced adaptive appraisals by randomly assigning 97 male and female participants to receive either instructions to appraise their anxiety as beneficial to the negotiation or no specific instructions on how to appraise the situation. We also measured participants’ cortisol responses prior to and following the negotiation. Results revealed that cortisol increases were positively related to negotiation performance for participants who were told to view anxiety as beneficial, and not detrimental, for negotiation performance (appraisal condition). In contrast, cortisol increases were negatively related to negotiation performance for participants given no instructions on appraising their anxiety (control condition). These findings offer a means through which to combat the potentially deleterious effects of heightened cortisol reactivity on negotiation outcomes

Semantic Interference Deficits and the Detection of Mild Alzheimer’s Disease and Mild Cognitive Impairment Without Dementia

Impairment in delayed recall has traditionally been considered a hallmark feature of Alzheimer’s disease (AD). However, vulnerability to semantic interference may reflect early manifestations of the disorder. In this study, 26 mildly demented AD patients (mild AD), 53 patients with mild cognitive impairment without dementia (MCI), and 53 normal community-dwelling elders were first presented 10 common objects that were recalled over 3 learning trials. Subjects were then presented 10 new semantically related objects followed by recall for the original targets. After controlling for the degree of overall memory impairment, mild AD patients demonstrated greater proactive but equivalent retroactive interference relative to MCI patients. Normal elderly subjects exhibited the least amount of proactive and retroactive interference effects. Recall for targets susceptible to proactive interference correctly classified 81.3% of MCI patients and 81.3% of normal elderly subjects, outperforming measures of delayed recall and rate of forgetting. Adding recognition memory scores to the model enhanced both sensitivity (84.6%) and specificity (88.5%). A combination of proactive and retroactive interference measures yielded sensitivity of 84.6% and specificity of 96.2% in differentiating mild AD patients from normal older adults. Susceptibility to proactive semantic interference may be an early cognitive feature of MCI and AD patients presenting for clinical evaluation. (JINS, 2004, 10, 91–100.

The Growth of Chickens as Effected by the Sunlight Transmitted through Glass Substitutes

Three weeks\u27 old chicks which had been deprived of direct sunlight and fed on a rachitic diet, were placed behind common glass and glass substitutes for four weeks. Those behind glass made an average gain of 180 per cent, while the groups behind the substitutes made gains of 300 per cent and 250 per cent. All outward appearances of rickets had disappeared among those behind the glass substitutes, while the disease was in evidence in the case of those behind glass