190 research outputs found
Retired athletes : when the spotlight dims : a thesis presented in partial fulfilment of the requirements for the degree of Master of Sport and Exercise, Massey University, Albany, New Zealand
The purpose of this study was to; (1) examine the experiences of elite New Zealand athletes
during the retirement transition and, (2) determine whether current retirement-related
assistance in New Zealand is perceived by elite athletes to enhance adjustment to retirement
from elite-level sport. An extensive literature review underlies the study by introducing
theories and models related to athletic retirement and examining what is currently known
about the experiences of elite athletes during the transition. Semi-structured interviews were
used to gather descriptive data from 16 former elite New Zealand athletes who retired within
seven years of commencement of the study. Data was analysed using NVivo software and
Taylor and Ogilvieâs (1994) conceptual model of adaptation to retirement was used in a
thematic analysis of data. This study provided clearer understanding of the experiences of
elite New Zealand athletes regarding the retirement transition, and helped to identify whether
current athlete retirement-related interventions are sufficient. As well, participants made
suggestions for future retirement interventions and/or changes to interventions currently
offered. New findings revealed that career/education interventions were available to and
highly used by 12 participants who were carded and had access to these interventions.
Availability and usage of psychological/emotional interventions was found to be limited or
non-existent. Findings that were aligned with or contested previous literature included multicausal
reasons led to all participantsâ retirements. Participants experienced high athletic
identity, high perceived control over their retirement, and retirements that, to varying degrees,
were both voluntary and involuntary. Pre-planning was the most prominent resource used and
enhanced participantsâ career prospects. Furthermore, it was found that most participants had
both positive and negative retirement experiences during the transition. Future research could
include longitudinal designs, which might provide a more accurate account of athletesâ
experiences and perceptions of the retirement transition as they occur, in particular the
variables (e.g. athletic identity, social support) encountered
Signatures consistent with multi-frequency tipping in the Atlantic meridional overturning circulation
The early detection of tipping points, which describe a rapid departure from
a stable state, is an important theoretical and practical challenge. Tipping
points are most commonly associated with the disappearance of steady state or
periodic solutions at fold bifurcations and are often associated with
hysteresis loops. We discuss here multi-frequency tipping (M-tipping), which is
tipping due to the disappearance of an attracting torus. M-tipping is a generic
phenomenon in systems with at least two intrinsic or external frequencies that
can interact and, hence, relevant to a wide variety of systems of interest. We
show that the more complicated sequence of bifurcations involved in M-tipping
provides a possible consistent explanation for as yet unexplained behaviour
observed near tipping in climate models for the Atlantic meridional overturning
circulation. More generally, this work provides a path towards identifying
possible early-warning signs of tipping in multiple-frequency systems.Comment: 14 pages, 4 figure
MoreFusion: Multi-object Reasoning for 6D Pose Estimation from Volumetric Fusion
Robots and other smart devices need efficient object-based scene
representations from their on-board vision systems to reason about contact,
physics and occlusion. Recognized precise object models will play an important
role alongside non-parametric reconstructions of unrecognized structures. We
present a system which can estimate the accurate poses of multiple known
objects in contact and occlusion from real-time, embodied multi-view vision.
Our approach makes 3D object pose proposals from single RGB-D views,
accumulates pose estimates and non-parametric occupancy information from
multiple views as the camera moves, and performs joint optimization to estimate
consistent, non-intersecting poses for multiple objects in contact.
We verify the accuracy and robustness of our approach experimentally on 2
object datasets: YCB-Video, and our own challenging Cluttered YCB-Video. We
demonstrate a real-time robotics application where a robot arm precisely and
orderly disassembles complicated piles of objects, using only on-board RGB-D
vision.Comment: 10 pages, 10 figures, IEEE Conference on Computer Vision and Pattern
Recognition (CVPR) 202
How Will Earth Respond to Plans for Carbon Dioxide Removal?
First Workshop of the Carbon Dioxide Removal Model Intercomparison Project; Potsdam, Germany, 20â22 September 201
Daisyworld: a review
Daisyworld is a simple planetary model designed to show the long-term effects of coupling between life and its environment. Its original form was introduced by James Lovelock as a defense against criticism that his Gaia theory of the Earth as a self-regulating homeostatic system requires teleological control rather than being an emergent property. The central premise, that living organisms can have major effects on the climate system, is no longer controversial. The Daisyworld model has attracted considerable interest from the scientific community and has now established itself as a model independent of, but still related to, the Gaia theory. Used widely as both a teaching tool and as a basis for more complex studies of feedback systems, it has also become an important paradigm for the understanding of the role of biotic components when modeling the Earth system. This paper collects the accumulated knowledge from the study of Daisyworld and provides the reader with a concise account of its important properties. We emphasize the increasing amount of exact analytic work on Daisyworld and are able to bring together and summarize these results from different systems for the first time. We conclude by suggesting what a more general model of life-environment interaction should be based on
Early warnings and missed alarms for abrupt monsoon transitions
Journal ArticlePalaeo-records from China demonstrate that the East Asian Summer Monsoon (EASM) is dominated by abrupt and large magnitude monsoon shifts on millennial timescales, switching between periods of high and weak monsoon rains. It has been hypothesized that over these timescales, the EASM exhibits two stable states with bifurcation-Type tipping points between them. Here we test this hypothesis by looking for early warning signals of past bifurcations in speleothem δ18O records from Sanbao Cave and Hulu Cave, China, spanning the penultimate glacial cycle. We find that although there are increases in both autocorrelation and variance preceding some of the monsoon transitions during this period, it is only immediately prior to the abrupt monsoon shift at the penultimate deglaciation (Termination II) that statistically significant increases are detected. To supplement our data analysis, we produce and analyse multiple model simulations that we derive from these data. We find hysteresis behaviour in our model simulations with transitions directly forced by solar insolation. However, signals of critical slowing down, which occur on the approach to a bifurcation, are only detectable in the model simulations when the change in system stability is sufficiently slow to be detected by the sampling resolution of the data set. This raises the possibility that the early warning "alarms" were missed in the speleothem data over the period 224-150 kyr and it was only at the monsoon termination that the change in the system stability was sufficiently slow to detect early warning signals
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Major Tipping Points in the Earthâs Climate System and Consequences for the Insurance Sector
A 2°C rise in temperature from pre-industrial levels has been widely regarded as a tipping point for planet earth. Major Tipping Points in Earth's Climate System and Consequences for the Insurance Sector argues instead that sudden volatile transformations in earth's climate will occur long before this 2°C threshold is reached
Impact of the GeoMIP G1 sunshade geoengineering experiment on the Atlantic meridional overturning circulation
We analyze the multi-earth system model responses of ocean temperatures and the Atlantic Meridional Overturning Circulation (AMOC) under an idealized solar radiation management scenario (G1) from the Geoengineering Model Intercomparison Project. All models simulate warming of the northern North Atlantic relative to no geoengineering, despite geoengineering substantially offsetting the increases in mean global ocean temperatures. Increases in the temperature of the North Atlantic Ocean at the surface (~0.25 K) and at a depth of 500 m (~0.10 K) are mainly due to a 10 Wmâ2 reduction of total heat flux from ocean to atmosphere. Although the AMOC is slightly reduced under the solar dimming scenario, G1, relative to piControl, it is about 37% stronger than under abrupt4 Ă CO2 . The reduction of the AMOC under G1 is mainly a response to the heat flux change at the northern North Atlantic rather than to changes in the water flux and the wind stress. The AMOC transfers heat from tropics to high latitudes, helping to warm the high latitudes, and its strength is maintained under solar dimming rather than weakened by greenhouse gas forcing acting alone. Hence the relative reduction in high latitude ocean temperatures provided by solar radiation geoengineering, would tend to be counteracted by the correspondingly active AMOC circulation which furthermore transports warm surface waters towards the Greenland ice sheet, warming Arctic sea ice and permafrost
Impacts of ocean waveâdependent momentum flux on global ocean climate
Accurate knowledge of airâsea fluxes of momentum, heat, and carbon are central to fully understanding the evolution of the climate system. The role of ocean surface waves has been largely overlooked in global climate models despite the growing body of work elucidating the influence of ocean wave state on airâsea fluxes. Here we account for the impact of ocean surface waves on global ocean climate using a global ocean model through implementation of waveâdependent momentum fluxes. Waveâdependent momentum fluxes improve the simulation of observed ocean heat content (OHC) through increasing the trend in OHC over the last three decades. Specifically, the larger increase in OHC is attributable to increased net heat flux in the Southern Hemisphere (SH). These results highlight the important role of accounting for waveâdependent momentum transfer in terms of both simulating future climate and understanding changes over the recent historical period
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