13,834 research outputs found
The dose-response relationship between training load and aerobic fitness in academy rugby union players
© 2018 Human Kinetics, Inc. Purpose: To identify the dose-response relationship between measures of training load (TL) and changes in aerobic fitness in academy rugby union players. Method: Training data from 10 academy rugby union players were collected during a 6-wk in-season period. Participants completed a lactate-threshold test that was used to assess VO 2 max, velocity at VO 2 max, velocity at 2 mmol/L (lactate threshold), and velocity at 4 mmol/L (onset of lactate accumulation; vOBLA) as measures of aerobic fitness. Internal-TL measures calculated were Banister training impulse (bTRIMP), Edwards TRIMP, Lucia TRIMP, individualized TRIMP (iTRIMP), and session RPE (sRPE). External-TL measures calculated were total distance, PlayerLoad™, high-speed distance > 15 km/h, very-high-speed distance > 18 km/h, and individualized high-speed distance based on each player’s vOBLA. Results: A second-order-regression (quadratic) analysis found that bTRIMP (R 2 = .78, P = .005) explained 78% of the variance and iTRIMP (R 2 = .55, P = .063) explained 55% of the variance in changes in VO 2 max. All other HR-based internal-TL measures and sRPE explained less than 40% of variance with fitness changes. External TL explained less than 42% of variance with fitness changes. Conclusions: In rugby players, bTRIMP and iTRIMP display a curvilinear dose-response relationship with changes in maximal aerobic fitness
Monitoring, Motivation and Management: The Determinants of Opportunistic Behavior in a Field Experiment
Economic models of incentives in employment relationships are based on a specific theory of motivation. Employees are 'rational cheaters,' who anticipate the consequences of their actions and shirk when the perceived marginal benefit exceeds the marginal cost. Managers respond to this decision calculus by implementing monitoring and incentive pay practices that lessen the attraction of shirking. This 'rational cheater model' is not the only model of opportunistic behavior, and indeed is viewed skeptically by human resource practitioners and by many non-economists who study employment relationships. We investigate the 'rational cheater model' using data from a double-blind field experiment that allows us to observe the effect of experimentally-induced variations in monitoring on employee opportunism. The experiment is unique in that it occurs in the context of an ongoing employment relationship, i.e., with the firm's employees producing output as usual under the supervision of their front-line managers. The results indicate that a significant fraction of employees behave roughly in ccordance with the 'rational cheater model.' We also find, however, that a substantial proportion of employees do not respond to manipulations in the monitoring rate. This heterogeneity is related to employee assessments about their general treatment by the emp loyer.
Karlee Sanders and Clara Taylor in a Joint Senior Voice Recital
This is the senior voice recital of Karlee Sanders and Clara Taylor held on October 22, 2021 in the McBeth Recital Hall in Mabee Fine Arts Center
Are children 'normal'?
In his classic work on the economics of fertility, Becker (1960) suggests that children are likely “normal.” We examine this contention. Our first step is documenting an empirical regularity about the cross section of white married couples in the U.S.: when we restrict comparisons to households living in broadly similar locations (e.g., in expensive urban areas, or in rural areas), completed fertility is positively correlated with the husband’s income. Two alternative models rationalize the data—one in which children are “normal” and a second in which the observed pattern emerges solely as a consequence of rational sorting by households. In an effort to sort out causal effects, we undertake a rather specialized empirical exercise to analyze the localized impact on fertility of the mid-1970s increase in world energy prices—an exogenous shock that substantially increased men’s incomes in the Appalachian coal-mining region. We find that children are indeed “normal.”Demography
The role of location in evaluating racial wage disparity
A standard object of empirical analysis in labor economics is a modified Mincer wage function in which an individual's log wage is specified to be a function of education, experience, and an indicator variable identifying race. Researchers hope that estimates from this exercise can be informative about the impact of minority status on labor market success. Here we set out a theoretical justification for this regression in a context in which individuals live and work in different locations. Our model leads to the traditional approach, but with the important caveat that the regression should include location-specific fixed effects. Given this insight, we reevaluate evidence about the black-white wage disparity in the United States.Income distribution ; Wages ; Discrimination in employment
Are Children "Normal"?
We examine Becker's (1960) contention that children are "normal." For the cross section of non-Hispanic white married couples in the U.S., we show that when we restrict comparisons to similarly-educated women living in similarly-expensive locations, completed fertility is positively correlated with the husband's income. The empirical evidence is consistent with children being "normal." In an effort to show causal effects, we analyze the localized impact on fertility of the mid-1970s increase in world energy prices – an exogenous shock that substantially increased men's incomes in the Appalachian coal-mining region. Empirical evidence for that population indicates that fertility increases in men's income.economics of fertility, location choice, Appalachian fertility
Sound waves in the intracluster medium of the Centaurus cluster
We report the discovery of ripple-like X-ray surface brightness oscillations
in the core of the Centaurus cluster of galaxies, found with 200 ks of Chandra
observations. The features are between 3 to 5 per cent variations in surface
brightness with a wavelength of around 9 kpc. If, as has been conjectured for
the Perseus cluster, these are sound waves generated by the repetitive
inflation of central radio bubbles, they represent around 5x10^42 erg/s of
spherical sound-wave power at a radius of 30 kpc. The period of the waves would
be 10^7 yr. If their power is dissipated in the core of the cluster, it would
balance much of the radiative cooling by X-ray emission, which is around
1.3x10^43 erg/s within the inner 30 kpc. The power of the sound waves would be
a factor of four smaller that the heating power of the central radio bubbles,
which means that energy is converted into sound waves efficiently.Comment: 5 page letter, 5 figures, accepted by MNRA
AGN feedback and iron enrichment in the powerful radio galaxy, 4C+55.16
We present a detailed X-ray analysis of 4C+55.16, an unusual and interesting
radio galaxy, located at the centre of a cool core cluster of galaxies.
4C+55.16 is X-ray bright (L(cluster)~10^45 erg/s), radio powerful, and shows
clear signs of interaction with the surrounding intracluster medium. By
combining deep Chandra (100 ks) with 1.4 GHz VLA observations, we find evidence
of multiple outbursts from the central AGN, providing enough energy to offset
cooling of the ICM (P_bubbles=6.7x10^44 erg/s). Furthermore, 4C+55.16 has an
unusual intracluster iron distribution showing a plume-like feature rich in Fe
L emission that runs along one of the X-ray cavities. The excess of iron
associated with the plume is around 10^7M_sol. The metal abundances are
consistent with being Solar-like, indicating that both SNIa and SNII contribute
to the enrichment. The plume and southern cavity form a region of cool
metal-rich gas, and at the edge of this region, there is a clear discontinuity
in temperature (from kT~2.5 keV to kT~5.0 keV), metallicity (from ~0.4 solar to
0.8 solar), and surface brightness distribution, consistent with it being
caused by a cold front. However, we also suggest that this discontinuity could
be caused by cool metal-rich gas being uplifted from the central AGN along one
of its X-ray cavities.Comment: 12 pages, 11 figures, 1 table, Accepted to MNRAS (minor revision
Participation and representation in ATSIC elections: a ten-year perspective
This paper examines participation and representation in Aboriginal and Torres Strait Islander Commission (ATSIC) elections over the ten-year period since its inception in 1990. It attempts to identify patterns of participation that seem to be emerging and what these might suggest about ATSIC's operation. By examining numbers of nominees compared to positions available, the paper suggests that ATSIC elected office has fairly keenly and consistently sought and competed for by Indigenous people, though there may have been some slight initial reticence in the 1990 elections. By examining voter numbers and voter turnout, the paper suggests that voter participation nation-wide rose slightly from 1990 to 1996 and then largely stabilised in 1999. It also suggests that there have been significant variations from this national pattern at State and Territory levels and it explores some reasons for this, such as change in postal voting procedures. The paper also examines voter numbers and voter turnout at the ATSIC regional level since 1993 and finds that there has been a much higher voter turnout in the sparsely settled regions of northern Australia and much lower voter turnout in the southern and urban areas. This is explained in terms of ATSIC program and expenditure priorities and in terms of polling place access. The final two sections of the paper examine the representation of women and Torres Strait Islanders among ATSIC elected representatives. Both are seen as significant issues, which should be of some ongoing concern within ATSIC, alongside the issue of the southern/northern difference in voter participation
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