37 resultados para curvilinear


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This study investigates the role of Type A personality in the effort-reward imbalance (ERI) model (n=899 operational police). Moderated multiple regression analyses, including tests for curvilinear effects, revealed that the model significantly predicted self-reported angina. Two interactions between Type A subscales and the effort-reward imbalance variables were significant. The findings support recent arguments that the pathogenic component of Type A is hostility, and suggest that both overt and covert hostility can have differential effects on employee perceptions of effort-reward imbalance.

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Differences in cashmere production and fleece attributes associated with farm of origin, age and sex were quantified for commercial Australian cashmere goat enterprises. From 11 farms in four states, 1147 does and 97 wethers were monitored, representing 1- to 13-year-old goats. Individual clean cashmere production ranged from 21 to 389 g, with a mean ± standard deviation value of 134 ± 62 g. The mean cashmere production of 2-year-old does from different farms varied from 69 to 225 g and averaged 141 g. Mean ± s.d. greasy fleece weight was 394 ± 123 g, clean washing yield was 90.8 ± 4.1%, clean cashmere yield 33.4 ± 9.4%, cashmere fibre diameter 16.4 ± 1.6 µm, fibre curvature 48 ± 8.7 degrees/mm and staple length 8.7 ± 2.1 cm. There were large, commercially significant differences between farms for clean cashmere weight, mean fibre diameter and other attributes of cashmere. These were much larger than the effects of age and sex. Farm and age accounted for 42 to 67% of the variation in clean cashmere production, mean fibre diameter, fibre curvature, staple length and clean washing yield. Farm of origin affected clean cashmere yield, accounting for 24% of the variation. Sex of the goats had only a minor effect on the staple length of cashmere. The responses to age of clean cashmere weight, mean fibre diameter and the inverse of fibre curvature are very similar. Generally, cashmere production and mean fibre diameter increased with age. For the majority of farms, cashmere fibre curvature declined in a curvilinear manner with increases in age of goat. There were large differences in cashmere staple length from different farms, with means ranging from 7 to 12 cm. Between 1 and 2 years of age, the staple length of cashmere demonstrated a constant proportional increase. At ages older than 2 years, staple length either declined or increased by less than 1 cm with age, depending on the farm of origin. This study demonstrates that there are large gains in productivity that can be achieved from Australian cashmere goats. A better understanding of on-farm factors that influence cashmere production would enable all producers to optimise their production systems.

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Applying a grounded-theory approach to analyzing the Global Entrepreneurship Monitor (GEM) data, we attempt to explain why New Zealand exhibits only a moderate level of economic development despite its high level of entrepreneurship. By statistically analyzing why 34 other countries in the 2005 GEM dataset exhibit small deviations from the classical quadratic curvilinear relationship between entrepreneurship and economic development, we develop a better understanding of the entrepreneurial framework conditions underlying New Zealand’s large deviation from this trend line. Based on our findings from the GEM data we make policy recommendations that could aid in moving New Zealand (and other countries) closer toward the trend line and thus promote economic development.

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The present study was conducted to evaluate the effect of different dietary lipid sources, age and sex on the SFA and MUFA metabolism in broiler chickens using a whole body fatty acid balance method. Four dietary lipid sources (palm fat, Palm; soyabean oil, Soya; linseed oil, Lin; and fish oil, Fish) were added at 3% to a basal diet containing 5% Palm. Diets were fed to female and male chickens from day 1 to either day 21 or day 42 of age. The accumulation (percentage of net intake and ex novo production) of SFA and MUFA was significantly lower in broilers fed on Palm than in broilers fed on the other diets (85·7 v. 97·4 %). Conversely, β-oxidation was significantly higher in Palm-fed birds than the average of the other dietary treatments (14·3 v. 2·6 %). On average, 33·1% of total SFA and MUFA accumulated in the body were elongated, and 13·8% were Δ-9 desaturated to longer chain or more unsaturated metabolites, with lower proportions being elongated and desaturated for the Palm and Fish diets than for the Soya and Lin diets. Total in vivo apparent elongase activity decreased exponentially in relation to the net intake of SFA and MUFA, while it increased with age. Total in vivo apparent Δ-9 desaturase activity was not significantly affected by dietary treatment or age. Total ex novo production and β-oxidation of SFA and MUFA showed a negative and positive curvilinear relationship with net intake of SFA and MUFA, respectively. Sex had no effect on SFA and MUFA metabolism.

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1. Harem polygyny can have fitness benefits and costs on females. In bark beetles of the genus Ips the latter may include within-harem competition between larvae. However, earlier competition between females for male care and mating opportunities may also influence oviposition behaviour. There has been relatively little investigation into the relationship between harem size and initial egg output. The present study investigated this relationship in the bark beetle Ips grandicollis.
2. The measure of egg output used was the number of eggs in the gallery with the most eggs in each harem. Mean ( ± SE) harem size of 242 observed harems was 3.25 ± 0.10. A curvilinear relationship was found between egg output and harem size, with females in smaller harems (one to four females) laying more eggs with increased harem size. However, females in larger harems (five to seven females) laid fewer eggs as harem size increased. The optimal harem size (in terms of number of eggs laid) was close to four females.
3. We found no evidence from a behavioural assay that females could preferentially choose unmated males over mated males with harems of two females. Additionally, the distribution of harem sizes suggests that females distribute themselves among males randomly.
4. The results suggest that harem size has effects on female reproduction that extend beyond larval competition and influence patterns of oviposition. The mechanism that determines why egg laying is greatest at intermediate levels is unknown. There is no evidence that smaller harems belong to lower quality males, but females may adjust egglaying behaviour in large harems as a result of reduced male attendance or anticipated larval competition.

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The overall purpose of this investigation was to examine the relationship between stress-related working conditions and three forms of employee performance behaviours: in-role behaviours, citizenship behaviours directed at other individuals and citizenship behaviours directed at the organization. The potentially stressful working conditions were based on the job strain model (incorporating job demands, job control and social support) as well as organizational justice theory. A sample of Australian-based police officers (n = 640) took part in this study and the data were collected via a mail-out survey. Multiple regression analyses were undertaken to assess both the strength and the nature of the relationships between the working conditions and employee performance and these analyses included tests for additive, interactional and curvilinear effects. The overall results indicated that a significant proportion of the explained variance in all three outcome measures was attributed to the additive effects of demand, control and support. The level of variance associated with the organizational justice dimensions was relatively small, although there were signs that specific dimensions of justice may provide unique insights into the relationship between job stressors and employee performance. The implications of these and other notable findings are discussed.

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The study examined if and how prominent stress-related working conditions were longitudinally associated with multiple employee performance behaviours. The findings revealed the positive influence of workload demands and the positive curvilinear effects attributed to relationship-based resources (support from colleagues, fair interpersonal treatments and fair information sharing) on performance long-term.

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In January 2009 The Times reported that the Historic Chapels Trust (HCT) was undertaking the preservation and conservation of the Chantry Chapel of Thorndon Hall, near Brentwood, Essex, England, once the seat of the Petre family, one of England’s oldest Catholic families. The chapel has lain severely neglected for many years with missing and loose tiles, blocked gutters, and heavily eroded stonework. In spite of its desperate need of repair, inside, glimpses of the richly carved and lavishly decorated interior remain, witness to exquisite craftsmanship. Because of its quality Nikolas Pevsner had attributed the building to A W N Pugin. More recent research has established that in fact William Wardell was the architect.

By 1854, when Lord Petre commissioned this mausoleum for his estate, Wardell would have been especially known for his London curvilinear decorated churches at Greenwich, Clapham and Hammersmith. Wardell produced three complete sets of drawings for the Chantry Chapel. Drawings for all three designs are extant, and give valuable insights into Wardell's design methods and the evolution of his design thinking. They raise questions about Early Victorian and High Victorian Gothic sensibilities and establish Wardell’s architectural and design credentials beyond a doubt. This paper explores Wardell’s debt to Pugin, posits the Chantry Chapel as a rival to Pugin’s St Giles Church, Cheadle, and considers the question of patronage.

Now acknowledged to be ‘of outstanding architectural and historic interest ‘ by HCT and English Heritage, the Chantry chapel - a crumbling fabulation - is the subject of major heritage considerations. Questions about authenticity in rebuilding and reconstruction are currently overridden by the urgent need to secure the structure from collapse.

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Softness of apparel textiles is a major attribute sought by consumers. There is surprisingly little objective information on the softness properties of rare animal fibres, particularly cashmere, alpaca and mohair. Samples of these and other rare animal fibres from different origins of production and processors were objectively measured for fibre diameter, fibre curvature (FC, crimp) and resistance to compression (softness). While there were curvilinear responses of resistance to compression to FC and to mean fibre diameter, FC accounted for much more of the variance in resistance to compression. Fibre type was an important determinant of resistance to compression. The softest fibres were alpaca, mohair and cashgora and all of the fibres measured were softer than most Merino wool. Quivet, llama, camel, guanaco, vicuña, yak wool, bison wool, dehaired cow down and Angora rabbit were also differentiated from alpaca, mohair and cashmere. There were important differences in the softness and FC of cashmere from different origins with cashmere from newer origins of production (Australia, New Zealand and USA) having lower resistance to compression than cashmere from traditional sources of China and Iran. Cashmere from different origins was differentiated on the basis of resistance to compression, FC and fibre diameter. Cashgora was differentiated from cashmere by having a lower FC and lower resistance to compression. There were minority effects of colour and fibre diameter variation on resistance to compression of cashmere. The implications of these findings for the identification and use of softer raw materials are discussed.

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Introduction: A systematic approach to managing the training of elite athletes is supported by accurate training load measurement. However, quantifying the training of elite Australian rowers is complex due to unique challenges: 1) the multi-centre, multi-state structure of the national program; 2) the variety of training undertaken, incorporating rowing-specific and non-specific modalities, with continuous and interval efforts that span the full intensity spectrum; and 3) the limitations of existing quantification methods for capturing total training loads undertaken from varied training. These challenges highlighted a need to create a consistent, location-independent framework for prescribing training in elite rowing, with a capacity to account for varied training. Methods: An in-house proprietary measure (the T2minute method) was developed at the National Rowing Centre of Excellence (NRCE), as a collaborative project between sport scientists and national squad coaches. The design phase was informed by assessments of the existing training measures, and built upon standardised intensity zones established at the Australian Institute of Sport. A common measurement unit was chosen: one T2minute equates to one minute of on-water single scull rowing at T2 intensity (∼60–72% VO2max). Each intensity zone was assigned a weighting factor according to the curvilinear relationship between power output, intensity, and blood lactate response. Each training mode was assigned a weighting factor based on whether coaches perceived it to be “harder” or “easier” than onwater rowing. With coaches’ feedback, the method was refined over a period of five months. The T2minute method was implemented as the core framework for prescribing training for elite Australian rowers throughout the 2009–2012 Olympic cycle. Results: The implementation of the T2minute method successfully established consistency with training prescription and monitoring practices within the NRCE high performance program. The national roll out this method has influenced rowing training methodology at elite and sub-elite levels in Australia. Since implementation, the method has undergone scientific validation. Further research is underway, utilising the method to explore complex relationships between rowers’ training and performance outcomes. Conclusion: The T2minute method is a novel approach that allows rowing coaches and sport scientists to utilise one consistent system to quantify load from varied training. Its implementation represents a considerable achievement in establishing a common framework for managing the training process within a complex organisational structure. This collaborative approach used to develop the T2minute method provides unique insight into the important considerations and practical challenges of applying training science to enhance elite sport performance.

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Background
Bioelectrical impedance (BIA) represents a simple, inexpensive and non-invasive method that is often used to assess fat-mass (FM) and fat-free mass (FFM) in large population-based cohorts.

Objective

The aim of this study was to describe the reference ranges and examine the influence of age and gender on FM, FFM and skeletal muscle mass (SMM) as well as height-adjusted estimates of FM [fat mass index (FMI)], FFM [fat-free mass index (FFMI)] and SMM [SMM index (SMI)] in a national, population-based cohort of Australian adults.

Design and Participants

The analytical sample included a total of 8,582 adults aged 25–91 years of Europid origin with complete data involved in the cross-sectional 1999–2000 Australian, Diabetes, Obesity and Lifestyle (AusDiab) Study.

Measurements

Bioelectrical impedance analysis was used to examine components of body composition. Demographic information was derived from a household interview.

Results

For both genders, FFM, SMM and SMI decreased linearly from the age of 25 years, with the exception that in men SMI was not related to age and FFM peaked at age 38 years before declining thereafter. The relative loss from peak values to ≥75 years in FFM (6–8%) and SMM (11–15%) was similar between men and women. For FM and FMI, there was a curvilinear relationship with age in both genders, but peak values were detected 6–7 years later in women with a similar relative loss thereafter. For FFMI there was no change with age in men and a modest increase in women.

Conclusion

In Australian adults there is heterogeneity in the age of onset, pattern and magnitude of changes in the different measures of muscle and fat mass derived from BIA, but overall the agerelated losses were similar between men and women.

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Climate change modelers predict increasingly frequent “extreme events,” so it is critical to quantify whether organismal responses (such as reproductive output) measured over the range of usual climatic conditions can predict responses under more extreme conditions. In a 20-year field study on water pythons (Liasis fuscus), we quantified the effects of climatically driven annual variation in food supply on demographic traits of female pythons (feeding rate, body size, body mass, and reproductive output). Reaction norms linking food supply to feeding rates and residual body mass were broadly linear, whereas norms linking food supply to female body size became curvilinear when a dramatic (flooding-induced) famine reduced the mean body size at sexual maturity. Thus, the reaction norms recorded over 16 years of “normal” (albeit highly variable) climatic conditions gave little insight into the population's response to a more extreme nutritional crisis.

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Development and implementation of a novel measure for quantifying training loads in rowing: The T2minute method. J Strength Cond Res 28(4): 1172–1180, 2014—The systematic management of training requires accurate training load measurement. However, quantifying the training of elite Australian rowers is challenging because of (a) the multicenter, multistate structure of the national program; (b) the variety of training undertaken; and (c) the limitations of existing methods for quantifying the loads accumulated from varied training formats. Therefore, the purpose of this project was to develop a new measure for quantifying training loads in rowing (the T2minute method). Sport scientists and senior coaches at the National Rowing Center of Excellence collaborated to develop the measure, which incorporates training duration, intensity, and mode to quantify a single index of training load. To account for training at different intensities, the method uses standardized intensity zones (T zones) established at the Australian Institute of Sport. Each zone was assigned a weighting factor according to the curvilinear relationship between power output and blood lactate response. Each training mode was assigned a weighting factor based on whether coaches perceived it to be “harder” or “easier” than on-water rowing. A common measurement unit, the T2minute, was defined to normalize sessions in different modes to a single index of load; one T2minute is equivalent to 1 minute of on-water single scull rowing at T2 intensity (approximately 60–72% V[Combining Dot Above]O2max). The T2minute method was successfully implemented to support national training strategies in Australian high performance rowing. By incorporating duration, intensity, and mode, the T2minute method extends the concepts that underpin current load measures, providing 1 consistent system to quantify loads from varied training formats.

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BACKGROUND: Physical activity (PA) has been consistently implicated in the etiology of obesity, whereas recent evidence on the importance of sedentary time remains inconsistent. Understanding of dose-response associations of PA and sedentary time with overweight and obesity in adults can be improved with large-scale studies using objective measures of PA and sedentary time. The purpose of this study was to examine the strength, direction and shape of dose-response associations of accelerometer-based PA and sedentary time with body mass index (BMI) and weight status in 10 countries, and the moderating effects of study site and gender. METHODS: Data from the International Physical activity and the Environment Network (IPEN) Adult study were used. IPEN Adult is an observational multi-country cross-sectional study, and 12 sites in 10 countries are included. Participants wore an accelerometer for seven consecutive days, completed a socio-demographic questionnaire and reported height and weight. In total, 5712 adults (18-65 years) were included in the analyses. Generalized additive mixed models, conducted in R, were used to estimate the strength and shape of the associations. RESULTS: A curvilinear relationship of accelerometer-based moderate-to-vigorous PA and total counts per minute with BMI and the probability of being overweight/obese was identified. The associations were negative, but weakened at higher levels of moderate-to-vigorous PA (>50 min per day) and higher counts per minute. No associations between sedentary time and weight outcomes were found. Complex site- and gender-specific findings were revealed for BMI, but not for weight status. CONCLUSIONS: On the basis of these results, the current Institute of Medicine recommendation of 60 min per day of moderate-to-vigorous PA to prevent weight gain in normal-weight adults was supported. No relationship between sedentary time and the weight outcomes was present, calling for further examination. If moderator findings are confirmed, the relationship between PA and BMI may be country- and gender-dependent, which could have important implications for country-specific health guidelines. © 2015 Macmillan Publishers Limited All rights reserved.

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Food marketing is facing increasing challenges in using portion size (e.g., “supersizing”) as a marketing tool.Marketers have used portion size to attract customers and encourage purchase, but social agencies areexpressing concern that larger portion sizes encourage greater consumption, which can cause excessiveconsumption and obesity. This article addresses two questions that are central to this debate: (1) How much effectdoes portion size have on consumption? and (2) Are there limits to this effect? A meta-analytic review reveals that,for a doubling of portion size, consumption increases by 35% on average. However, the effect has limits. Anextended analysis shows that the effect of portion size is curvilinear: as portions become increasingly larger, theeffect diminishes. In addition, although the portion-size effect is widespread and robust across a range of individualand environmental factors, the analysis shows that it is weaker among children, women, and overweightindividuals, as well as for nonsnack food items and in contexts in which more attention is given to the food beingeaten.