54,231 research outputs found
Why are people afraid of the dentist?:Observations and explanations
Objective: The aim of this review was to explore the peer-reviewed literature to answer the question: 'Why are people afraid of the dentist?' Method: Relevant literature was identified by searching the following on-line databases: PubMed, PsycInfo, the Cochrane Library and Google Scholar. Publications were extracted if they explored the causes and consequences of dental fear, dental anxiety or dental phobia. Results: The research evidence suggests that the causes of dental fear, dental anxiety or dental phobia are related to exogenous factors such as direct learning from traumatic experiences, vicarious learning through significant others and the media, and endogenous factors such as inheritance and personality traits. Each individual aetiological factor is supported by the evidence provided. Conclusions: The evidence suggests that the aetiology of dental fear, anxiety or phobia is complex and multifactorial. The findings show that there are clear practical implications indicated by the existing research in this area: a better understanding of dental fear, anxiety and phobia may prevent treatment avoidance. © 2013 S. Karger AG, Basel.</p
Computerized polar plots by a cathode ray tube/grid overlay method
Overlay is aligned with four calibration dots so it is not affected by CRT drift or changes in vertical or horizontal gain when producing Nyquist /frequency-response phase/amplitude/ plots. Method produces over 50 plots per hour
The relationship between habitual dietary protein intake and dual task performance in sedentary, recreationally active, and masters athlete older adults
As the body ages, physical and cognitive declines can result in balance and mobility deficits, but research has shown that proper nutrition and exercise can help maintain physical and mental capacity. The purpose of this study was to analyze the relationship between habitual dietary protein intake and dual task performance in sedentary (SED), recreationally active (RA), and masters athletes (MA). To measure physical activity levels, the Rapid Physical Activity Questionnaire (RAPA) was completed by all participants. The participants were placed into a high or low protein group using the ASA-24 hour dietary recall. If the participant consumed less than 0.8 g/kg of protein per day, they were placed in the low protein group; if the participant consumed more than 0.8 g/kg of protein per day, they were placed in the high protein group. Participants completed four different walking tasks: habitual speed, maximal speed, dual-task habitual speed, and dual-task maximal speed. Gait speed was measured over a distance of 10 meters. SED, RA, and MA consumed a mean of 0.84, 1.13, and 1.57 grams of protein per kilogram body weight per day, respectively. MA consumed significantly more protein than SED or RA participants (α \u3c .05). The low protein group consumed 0.84 g/kg of protein ± 0.39 while the high protein group consumed 1.30 g/kg of protein ± 0.50. There was no significant correlation between amount of protein consumed and dual task performance. While the results were for dual task performance not statistically significant, they may have clinical significance; when comparing the high and low protein groups for the dual task habitual trial, the high protein group covered the 10-m distance 0.73 seconds faster than the low protein group. Clinically, the higher protein group may be able to perform activities of daily living more efficiently
The Two Faces of Unionism
Our research demonstrates that the view of unions as organizations whose chief function is to raise wages is seriously misleading. For in addition to raising wages, unions have significant non-wage effects which influence diverse aspects of modern industrial life. By providing workers with a voice both at the workplace and in the political arena, unions can and do affect positively the functioning of the economic and social systems. Although our research on the non-wage effects of trade unions is by no means complete and some results will surely change as more evidence becomes available, enough work has been done to yield the broad outlines of a new view of unionism.
A computer model of solar panel-plasma interactions
High power solar arrays for satellite power systems are presently being planned with dimensions of kilometers, and with tens of kilovolts distributed over their surface. Such systems face many plasma interaction problems, such as power leakage to the plasma, particle focusing, and anomalous arcing. These effects cannot be adequately modeled without detailed knowledge of the plasma sheath structure and space charge effects. Laboratory studies of 1 by 10 meter solar array in a simulated low Earth orbit plasma are discussed. The plasma screening process is discussed, program theory is outlined, and a series of calibration models is presented. These models are designed to demonstrate that PANEL is capable of accurate self consistant space charge calculations. Such models include PANEL predictions for the Child-Langmuir diode problem
The Impact of Collective Bargaining: Illusion or Reality?
This paper reviews a significant body of evidence regarding the impact of trade unionism on economic performance and seeks to evaluate antithetical views regarding whether estimated differences between union and nonunion workers and firms represent: illusions created by poor experiments, real effects explicable solely in price-theoretic terms, or real effects which reflect the non wage-related dimensions of trade unions. The review yields conclusions on both the substantive questions at hand and the methodologies which have been used to address their validity. With respect to the illusion/reality debate, the preponderance of extant evidence indicates that union effects on a wide variety of economic variables estimated with cross-sectional data are real. Moreover, since the effects of unions on nonwage outcomes generally come from models which hold fixed the level of wages and variables affected by wages, the evidence supports the view that unions do much more than simply raise wages as an economic monopolist. While, in this study, we do not examine interpretations of these nonwage effects, the effects represent an empirical foundation for the "institutional" view of unionism, which is described in Section I. With respect to methods for evaluating the quality of standard cross-sectional experiments, some techniques appear more useful than others. In particular, we find that sensitivity analyses of single-equation results and longitudinal experiments provide valuable checks on cross-sectional findings while multiple-equations approaches produce results which are much too unstable to help resolve the questions of concern.
Parallel projected variable metric algorithms for unconstrained optimization
The parallel variable metric optimization algorithms of Straeter (1973) and van Laarhoven (1985) are reviewed, and the possible drawbacks of the algorithms are noted. By including Davidon (1975) projections in the variable metric updating, researchers can generalize Straeter's algorithm to a family of parallel projected variable metric algorithms which do not suffer the above drawbacks and which retain quadratic termination. Finally researchers consider the numerical performance of one member of the family on several standard example problems and illustrate how the choice of the displacement vectors affects the performance of the algorithm
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