45 research outputs found
Choices in an Interdependent Economic Environment: Inequity Aversion and Bargaining Games
Experimental economics has revealed an underlying tension between preferences for fairness and the purely self-interested behavior assumed throughout economic theory. Though many models attempt to explain observed behavior that is inconsistent with theory, the motivations behind such deviations from theoretic equilibrium are still largely unknown.
This paper investigates preferences for fairness in a controlled laboratory setting using an ultimatum game variant. Payoffs to participants are altered over several treatments to examine if subjects exhibit behavior that is consistent with a preference model which incorporates envy and guilt into an individual’s utility function. The results indicate evidence of both guilt and envy in participant behavior, and shed further light on the tension between fairness preferences and self-interest in the ultimatum bargaining game
The distance-time relationship and its use in endurance training and performance
The aims of this thesis were to develop a time efficient field test of the distance-time relationship, assess its validity, reliability and sensitivity and utilise the test to monitor and prescribe endurance training in distance runners. Laboratory-based tests of the distance-time relationship often use lengthy recovery periods between trials, resulting in multiple visits and limiting their practical application. A field-based test, completed in a single visit, could improve the utility of the distance-time relationship.
A novel single visit field test comprising of 3 constant-distance trials, separated by a 30-minute recovery, was designed. This test estimates the highest sustainable rate of aerobic metabolism, or critical speed (CS), and the modelled maximum distance performed above CS (D’). When compared to a traditional multi-visit laboratory protocol, field test CS was highly correlated (r=0.89, P0.05) and high typical error (334-1709 s). Non-linear modelling of recovery did not improve the accuracy. A high variability in D’ may in part explain the low predictive ability of the models.
The conclusion from this thesis is that the single visit field test is a valid, reliable and sensitive test for CS, which provides a favourable alternative to multi-visit laboratory-based testing
Acute Ingestion of a Commercially Available Pre-workout Supplement Improves Anaerobic Power Output and Reduces Muscular Fatigue
International Journal of Exercise Science 15(6): 455-472, 2022. The effect of a pre-workout supplement on anaerobic power output and muscular fatigue was examined. 18 participants took part in this double-blinded crossover study, reporting for testing on 3 occasions. Participants completed a 6x6 second repeated sprint test, with 20s recovery between sprints. Anaerobic power output was recorded as the highest power achieved during sprint test. Muscular fatigue was reported as a fatigue index across the six sprints ((maximum power – minimum power) ÷ total sprint time). During a baseline visit, participants consumed 250ml of water 30 minutes prior to testing, whilst in subsequent visits a taste-matched placebo (250ml water mixed with sugar-free juice) or a pre-workout supplement (250ml water mixed with one serving of ‘THE PRE’ myprotein.com). Anaerobic power output increased following pre-workout ingestion (pre-workout supplement, 885.8 ± 216.9W; Placebo, 853.6 ± 206.5W; Baseline, 839.3 ± 192.6W). Baseline vs pre-workout supplement (p = 0.01, g = 0.30); Placebo vs pre-workout supplement (p = 0.01, g = 0.20); Baseline vs Placebo (p = 0.59 g = 0.09). Muscular fatigue was reduced following pre-workout ingestion (Baseline, 4.92 ± 1.83W.s; Placebo, 4.39 ± 1.93W.s; pre-workout supplement, 3.31 ± 1.34W.s). Baseline vs pre-workout supplement (p = \u3c 0.01 g = 0.98); Placebo vs pre-workout supplement (p = 0.01, g = 0.63); Baseline vs Placebo (p = 0.20, g = 0.28). Acute ingestion of a pre-workout supplement significantly improves anaerobic power output and attenuates muscular fatigue during repeated sprint cycling
Integration of acoustic emission systems within Integri-Tech™ analysis system for structural health monitoring of pressurised engineering plant
The aim of this Acoustic Emission (AE) based Structural Health Monitoring project is to enable accurate location of AE sources in pressurised engineering plant and to use AE source location data to establish defect locations for use within Integri-Tech™; a finite element based analysis, monitoring and fitness for service assessment system. Integri-Tech™ is a windows based system which carries out combined analysis and assessment providing fatigue life and remnant life calculations and inspection priorities presenting the results in an accessible web portal format. The software uses finite element stress models created in the companion software Model Wizard. The AE monitoring system that has been developed can be used with an array of up to four AE broad band sensor channels with associated signal processing. Using a flexible approach in MATLAB, the authors have developed algorithms which were used for analysing the received AE signals to extract information about the nature and location of the source. The ability to carry out source location and possibly perform real time monitoring (detecting cracking as it occurs) is attractive feature of the AE system developed for this project. The time of arrival (TOA) data was used by Integri-Tech™ software to calculate source location using its own built-in algorithm, and this was verified independently using a MATLAB approach
Mesozoic–Tertiary exhumation history of the Altai Mountains, northern Xinjiang, China: New constraints from apatite fission track data
This study uses apatite fission track (FT) analysis to constrain the exhumation history of bedrock samples collected from the Altai Mountains in northern Xinjiang, China. Samples were collected as transects across the main structures related to Palaeozoic crustal accretion events. FT results and modeling identify three stages in sample cooling history spanning the Mesozoic and Tertiary. Stage one records rapid cooling to the low temperature part of the fission track partial annealing zone circa 70 ± 10 °C. Stage two, records a period of relative stability with little if any cooling taking place between 75 and 25–20 Ma suggesting the Altai region had been reduced to an area of low relief. Support for this can be found in the adjacent Junngar Basin that received little if any sediment during this interval. Final stage cooling took place in the Miocene at an accelerated rate bringing the sampled rocks to the Earth's surface. This last stage, linked to the far field effects of the Himalayan collision, most likely generated the surface uplift and relief that define the present-day Altai Mountains
Profiling the physiological parameters of boxers in The Parachute Regiment. 'Every man an Emperor'
This study aimed to collect and identify the physiological parameters that are required to produce winning performances in an army boxing competition. Army boxing competitions are sanctioned and governed by ‘England Boxing’ and consist of three rounds of two minutes with one-minute restorative periods. The Parachute Regiment are an elite infantry fighting force within the British military, with a continued success in the inter-army boxing championships. 22 male participants were recruited (mean ± SD age 28 ± 2 years, stature 178 ± 8.1cm, body mass 79 ± 7.1 kg, BMI 24.9 ±2.5).Body fat %. V̇O₂max, lower limb power, and 1RM max strength test protocols for back squat and bench press were performed. Additionally, impact punch power measured from rear hand cross strikes, and punching velocities were measured using a linear positional transducer. Countermovement (CMJ) and repetitive (n=10) jump data were collected using a jump mat. The physiological parameters in mean scores; body composition showed body fat 11.8±8.1%: CMJ height 35.5±5cm: Repetitive jump 28.5±5.6cm: Wingate peak power (body mass to power ratio) 11.5±1.6W/kg: Wingate average power, 8.1±1.4W/kg: V̇O₂max 53±4.8 ml.kg⁻¹.min⁻¹: Back squat (body mass to weight lifted ratio) 1.95±0.2kg: Bench press 1.1±0.1kg/BW: Rear cross strike velocity 8.47±0.8m/s: Impact power 15227±2250W. Significant relationships were observed between anthropometric data and power, strike velocity and V̇O₂max in addition to relationships being evident between some strength and power variables. by the participants in this study. Although punch impact power is an essential performance indicator in boxing, other physiological factors, such as lower limb power and strength have been demonstrated to attribute to the continued winning performances by 3PARA boxing team
How well do global ocean biogeochemistry models simulate dissolved iron distributions?
Numerical models of ocean biogeochemistry are relied upon to make projections about the impact of climate change on marine resources and test hypotheses regarding the drivers of past changes in climate and ecosystems. In large areas of the ocean, iron availability regulates the functioning of marine ecosystems and hence the ocean carbon cycle. Accordingly, our ability to quantify the drivers and impacts of fluctuations in ocean ecosystems and carbon cycling in space and time relies on first achieving an appropriate representation of the modern marine iron cycle in models. When the iron distributions from 13 global ocean biogeochemistry models are compared against the latest oceanic sections from the GEOTRACES program, we find that all models struggle to reproduce many aspects of the observed spatial patterns. Models that reflect the emerging evidence for multiple iron sources or subtleties of its internal cycling perform much better in capturing observed features than their simpler contemporaries, particularly in the ocean interior. We show that the substantial uncertainty in the input fluxes of iron results in a very wide range of residence times across models, which has implications for the response of ecosystems and global carbon cycling to perturbations. Given this large uncertainty, iron fertilization experiments based on any single current generation model should be interpreted with caution. Improvements to how such models represent iron scavenging and also biological cycling are needed to raise confidence in their projections of global biogeochemical change in the ocean
How well do global ocean biogeochemistry models simulate dissolved iron distributions?
Consistent patterns of common species across tropical tree communities
Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe