3,624 research outputs found
Electron impact promoted fragmentation of alkyl-N-(1-Phenylethyl)-carbamates of primary, secondary and tertiary alcohols
Mass spectra of alkyl carbamates derived from primary, secondary, and teriary alcohols by use of deuterium labeling and high resolution mass spectroscop
The development of fatigue during match-play tennis
Data describing the activity profile and physiological characteristics of tennis match-play are extensive. However, these data have generally provided descriptive accounts of the one-off match-play of amateur or lowly ranked professional players lasting 5 h. Furthermore, there is a distinct lack of evidencebased insight regarding the manifestation of fatigue within and between tennis matches, notwithstanding that skeletal muscle function has been reported to reduce following prolonged match-play. Moreover, it is evident that match-play evokes pronounced and prolonged physiological, neuromuscular and psychological perturbations that may be exacerbated with consecutive days of match-play. Separate to these internal load responses, a collection of non-uniform movement and technical performance changes are reported, though rarely from match-play data. Consequently, direct or causal links between altered physiological or muscle contractile function and subsequent match-play outcomes are lacking. Indeed, emerging evidence seems to infer that players adjust their game strategy, and the resultant execution of stroke play, to accommodate any such deterioration in physiological function. The purpose of this review was to discuss the available literature in terms of the physiological, mechanical and psychological responses that occur during prolonged match-play in the context of their likely effect on match-play performance
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Grouping Individual Investment Preferences in Retirement Savings: A Cluster Analysis of a USS Members Risk Attitude Survey
Cluster analysis is used to identify homogeneous groups of members of USS in terms of risk attitudes. There are two distinct clusters of members in their 40s and 50s. One had previously ‘engaged’ with USS by making additional voluntary contributions. It typically had higher pay, longer tenure, less interest in ethical investing, lower risk capacity, a higher percentage of males, and a higher percentage of academics than members of the ‘disengaged’ cluster. Conditioning only on the attitude to risk responses, there are 18 clusters, with similar but not identical membership, depending on which clustering method is used. The differences in risk aversion across the 18 clusters could be explained largely by differences in the percentage of females and the percentage of couples. Risk aversion increases as the percentage of females in the cluster increases, while it reduces as the percentage of couples increases because of greater risk sharing within the household. Characteristics that other studies have found important determinants of risk attitudes, such as age, income and (pension) wealth, do not turn out to be as significant for USS members. Further, despite being on average more highly educated than the general population, USS members are marginally more risk averse than the general population, controlling for salary, although the difference is not significant
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One size fits all: How many default funds does a pension scheme need?
In this paper, we analyse the number of default investment funds appropriate for an occupational defined contribution pension scheme. Using a unique dataset of member risk attitudes and characteristics from a survey of a large UK pension scheme, we apply cluster analysis to identify two distinct groups of members in their 40s and 50s. Further analysis indicated that the risk attitudes of the two groups were not significantly different, allowing us to conclude that a single lifestyle default fund is appropriate
Factors in the practice environment of nurses working in inpatient mental health: A partial least squares path modeling approach
Background: Developing a therapeutic relationship with consumers is considered as the central aspect of nursing work in mental health. The importance of this relationship stems from its association with enhanced patient care and improved patient outcomes. Factors within the practice environment may influence the nurse's ability to engage effectively in this relationship. Objective: This study explored a model that added characteristics of the individual and practice environment to a central framework incorporating therapeutic commitment: a nurse's ability and willingness to engage in a therapeutic relationship. Setting and participants: Data were collected at six mental health nursing units in five public general acute hospitals in New South Wales, Australia for 14 days per unit, between 2005 and 2006. All nurses in participating wards were invited to partake in the study. Seventy-six (51%) responses were analyzed. Method: The data were collected using a Nurse Survey inclusive of the Practice Environment Scale of the Nursing Work Index (NWI-PES), and the Mental Health Problems Perception Questionnaire (MHPPQ). A Unit Profile form was used concurrently to collect staffing, skill mix and patient turnover data. Partial least squares path modeling (PLS-PM) was chosen as the analytical method to test the model and identify the most influential factors. Results: Experienced nurses who perceived themselves to be competent and supported were more likely to express a willingness to engage therapeutically with patients. Environmental factors associated with these perceptions included foundations of quality nursing care, opportunities to participate in hospital affairs and clinical supervision. Not all elements in the proposed model were supported. Conclusion: Positive hospital practice environments can improve the capacity of nurses working in mental health to engage therapeutically with patients. Specific approaches may include access to preceptorship, continued education and career development opportunities, together with clinical supervision, improved continuity of care, and the involvement of mental health nurses in the governance of the hospital. © 2011 Elsevier Ltd
The effects of compression garments on performance of prolonged manual-labour exercise and recovery
© 2016, National Research Council of Canada. All rights reserved. This study investigated the effects of wearing compression garments during and 24 h following a 4-h exercise protocol simulating manual-labour tasks. Ten physically trained male participants, familiar with labouring activities, undertook 4 h of work tasks characteristic of industrial workplaces. Participants completed 2 testing sessions, separated by at least 1 week. In the experimental condition, participants wore a full-length compression top and compression shorts during the exercise protocol and overnight recovery, with normal work clothes worn in the control condition. Testing for serum creatine kinase and C-reactive protein, handgrip strength, knee flexion and extension torque, muscle stiffness, perceived muscle soreness and fatigue as well as heart rate and rating of perceived exertion (RPE) responses to 4-min cycling were performed before, following, and 24 h after exercise. Creatine kinase, muscle soreness, and rating of perceived fatigue increased following the exercise protocol (p 0.05). Knee extension torque was significantly higher in the control condition at 24 h postexercise (3.1% ± 5.4% change; compression: 2.2% ± 11.1% change), although no other variables were different between conditions at any time. However, compression demonstrated a moderate-large effect (d > 0.60) to reduce perceived muscle soreness, fatigue, and RPE from standardised warm-up at 24 h postexercise. The current findings suggest that compression may assist in perceptual recovery from manual-labour exercise with implications for the ability to perform subsequent work bouts
Comparison of athlete-coach perceptions of internal and external load markers for elite junior tennis training
Purpose: To investigate the discrepancy between coach and athlete perceptions of internal load and notational analysis of external load in elite junior tennis. Methods: Fourteen elite junior tennis players and 6 international coaches were recruited. Ratings of perceived exertion (RPEs) were recorded for individual drills and whole sessions, along with a rating of mental exertion, coach rating of intended session exertion, and athlete heart rate (HR). Furthermore, total stroke count and unforced-error count were notated using video coding after each session, alongside coach and athlete estimations of shots and errors made. Finally, regression analyses explained the variance in the criterion variables of athlete and coach RPE. Results: Repeated-measures analyses of variance and interclass correlation coefficients revealed that coaches significantly (P < .01) underestimated athlete session RPE, with only moderate correlation (r = .59) demonstrated between coach and athlete. However, athlete drill RPE (P = .14; r = .71) and mental exertion (P = .44; r = .68) were comparable and substantially correlated. No significant differences in estimated stroke count were evident between athlete and coach (P = .21), athlete notational analysis (P = .06), or coach notational analysis (P = .49). Coaches estimated significantly greater unforced errors than either athletes or notational analysis (P < .01). Regression analyses found that 54.5% of variance in coach RPE was explained by intended session exertion and coach drill RPE, while drill RPE and peak HR explained 45.3% of the variance in athlete session RPE. Conclusion: Coaches misinterpreted session RPE but not drill RPE, while inaccurately monitoring error counts. Improved understanding of external- and internal-load monitoring may help coach-athlete relationships in individual sports like tennis avoid maladaptive training. © 2014 Human Kinetics, Inc
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