57 research outputs found
Asymmetry During Maximal Sprint Performance in 11- to 16-Year-Old Boys
Purpose:
The aim of this study was to examine the influence of age and maturation upon magnitude of asymmetry in the force, stiffness and the spatiotemporal determinants of maximal sprint speed in a large cohort of boys.
Methods:
344 boys between the ages of 11 and 16 years completed an anthropometric assessment and a 35 m sprint test, during which sprint performance was recorded via a ground-level optical measurement system. Maximal sprint velocity, as well as asymmetry in spatiotemporal variables, modeled force and stiffness data were established for each participant. For analysis, participants were grouped into chronological age, maturation and percentile groups.
Results:
The range of mean asymmetry across age groups and variables was 2.3â12.6%. The magnitude of asymmetry in all the sprint variables was not significantly different across age and maturation groups (p > .05), except relative leg stiffness (p < .05). No strong relationships between asymmetry in sprint variables and maximal sprint velocity were evident (rs < .39).
Conclusion:
These results provide a novel benchmark for the expected magnitude of asymmetry in a large cohort of uninjured boys during maximal sprint performance. Asymmetry in sprint performance is largely unaffected by age or maturation and no strong relationships exist between the magnitude of asymmetry and maximal sprint velocity
Maximal sprint speed in boys of increasing maturity
The purpose of this study was to examine the natural development of the mechanical features of sprint performance in relation to maturation within a large cohort of boys. Three hundred and thirty-six boys (11â15 years) were analyzed for sprint performance and maturation. Maximal speed, stride length (SL), stride frequency (SF), flight time (FT) and contact time (CT) were assessed during a 30m sprint. Five maturation groups (G1â5) were established based on age from peak height velocity (PHV) where G1=>2.5years pre-PHV, G2 = 2.49â1.5years pre-PHV, G3 = 1.49â0.5years pre-PHV, G4 = 0.49years pre- to 0.5years post-PHV and G5 = 0.51â1.5years post-PHV. There was no difference in maximal speed between G1, G2 and G3 but those in G4 and G5 were significantly faster (p .05). SF decreased while CT increased (both p .05) were observed for either variable between G3, G4 and G5. While G1â3 increased their SL, concomitant decreases in SF and increases in CT prevented them from improving maximal speed. Maximal sprint speed appears to develop around and post-PHV as SF and CT begin to stabilize, with increases in maximal sprint speed in maturing boys being underpinned by increasing SL
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https://openspace.dmacc.edu/banner_news/1382/thumbnail.jp
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https://openspace.dmacc.edu/banner_news/1383/thumbnail.jp
Effects of combining physical activity with psychotherapy on mental health and well-being: A systematic review
Objective
: Despite a vast evidence-base advocating the psychological benefits of physical activity, relatively little is understood about how combining physical activity with psychological therapies may influence these positive effects. The aim of this paper is to systematically analyse evidence from studies adopting a combined approach, and identify potential mechanisms of action on clinical outcomes.
Methods
: The Embase, PsycINFO and Medline (PubMed and OVID) databases were searched for applicable trials published up to December 2018. Relevant data was extracted from eligible studies, and the Effective Public Health Practice Project (EPHPP) tool was utilised to objectively assess the quality of each study.
Results
: Twenty-two studies met the inclusion criteria, seven of which were rated as methodologically `strong'. Combining physical activity with psychological therapy consistently engendered positive effects on outcomes compared with treatment as usual. Similar improvements in psychological outcomes were observed in most (7/8) groups receiving physical activity alone. Increased levels of physical activity were observed in psychologically-informed interventions, however this effect was unrelated to changes in psychological outcomes.
Limitations
: Clinical and methodological heterogeneity precluded meta-analyses of results, while risk of bias detected in the studies may compromise overall validity of the findings.
Conclusions
: Physical activity interventions may be a viable alternative to psychological therapies, provided psychological approaches are incorporated into the implementation design (i.e. behavioural activation). Improved psychological outcomes may be observed regardless of `dose' received, however further research is required to ascertain whether psychosocial mechanisms of change mediate positive effects
Force steps during viral DNA packaging ?
Biophysicists and structural biologists increasingly acknowledge the role
played by the mechanical properties of macromolecules as a critical element in
many biological processes. This change has been brought about, in part, by the
advent of single molecule biophysics techniques that have made it possible to
exert piconewton forces on key macromolecules and observe their deformations at
nanometer length scales, as well as to observe the mechanical action of
macromolecules such as molecular motors. This has opened up immense
possibilities for a new generation of mechanical investigations that will
respond to such measurements in an attempt to develop a coherent theory for the
mechanical behavior of macromolecules under conditions where thermal and
chemical effects are on an equal footing with deterministic forces. This paper
presents an application of the principles of mechanics to the problem of DNA
packaging, one of the key events in the life cycle of bacterial viruses with
special reference to the nature of the internal forces that are built up during
the DNA packaging process.Comment: 18 pages, 7 figures, To appear in the Journal of Mechanics and
Physics of Solid
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Crop Updates 2005 - Farming Systems
This session covers forty four papers from different authors:
PLENARY
1. 2005 Outlook, David Stephens and Nicola Telcik, Department of Agriculture
FERTILITY AND NUTRITION
2. The effect of higher nitrogen fertiliser prices on rotation and fertiliser strategies in cropping systems, Ross Kingwell, Department of Agriculture and University of Western Australia
3. Stubble management: The short and long term implications for crop nutrition and soil fertility, Wayne Pluske, Nutrient Management Systems and Bill Bowden, Department of Agriculture
4. Stubble management: The pros and cons of different methods, Bill Bowden, Department of Agriculture, Western Australia and Mike Collins, WANTFA
5. Effect of stubble burning and seasonality on microbial processes and nutrient recycling, Frances Hoyle, The University of Western Australia
6. Soil biology and crop production in Western Australian farming systems, D.V. Murphy, N. Milton, M. Osman, F.C. Hoyle, L.K Abbott, W.R. Cookson and S. Darmawanto, The University of Western Australia
7. Urea is as effective as CAN when no rain for 10 days, Bill Crabtree, Crabtree Agricultural Consulting
8. Fertiliser (N,P,S,K) and lime requirements for wheat production in the Merredin district, Geoff Anderson, Department of Agriculture and Darren Kidson, Summit Fertilizers
9. Trace element applications: Up-front verses foliar? Bill Bowden and Ross Brennan, Department of Agriculture
10. FertcareÂź, Environmental Product Stewardship and Advisor Standards for thee Fertiliser Industry, Nick Drew, Fertilizer Industry Federation of Australia (FIFA)
SOIL AND LAND MANAGEMENT
11. Species response to row spacing, density and nutrition, Bill Bowden, Craig Scanlan, Lisa Sherriff, Bob French and Reg Lunt, Department of Agriculture
12. Investigation into the influence of row orientation in lupin crops, Jeff Russell, Department of Agriculture and Angie Roe, Farm Focus Consultants
13. Deriving variable rate management zones for crops, Ian Maling, Silverfox Solutions and Matthew Adams, DLI
14. In a world of Precision Agriculture, weigh trailers are not passé, Jeff Russell, Department of Agriculture
15. Cover crop management to combat ryegrass resistance and improve yields, Jeff Russell, Department of Agriculture and Angie Roe, Farm Focus Consultants
16. ARGT home page, the place to find information on annual ryegrass toxicity on the web, Dr George Yan, BART Pty Ltd
17. Shallow leading tine (SLT) ripper significantly reduces draft force, improves soil tilth and allows even distribution of subsoil ameliorants, Mohammad Hamza, Glen Riethmuller and Wal Anderson, Department of Agriculture
PASTURE ANS SUMMER CROP SYSTEMS
18. New annual pasture legumes for Mediteranean farming systems, Angelo Loi, Phil Nichols, Clinton Revell and David Ferris, Department of Agriculture
19. How sustainable are phase rotations with Lucerne? Phil Ward, CSIRO Plant Industry
20. Management practicalities of summer cropping, Andrea Hills and Sally-Anne Penny, Department of Agriculture
21. Rainfall zone determines the effect of summer crops on winter yields, Andrea Hills, Sally-Anne Penny and David Hall, Department of Agriculture
22. Summer crops and water use, Andrea Hills, Sally-Anne Penny and David Hall, Department of Agriculture, and Michael Robertson and Don Gaydon, CSIRO Brisbane
23. Risk analysis of sorgum cropping, Andrea Hills and Sally-Anne Penny, Department of Agriculture, and Dr Michael Robertson and Don Gaydon, CSIRO Brisbane
FARMER DECISION SUPPORT AND ADOPTION
24. Variety release and End Point Royalties â a new system? Tress Walmsley, Department of Agriculture
25. Farming system analaysis using the STEP Tool, Caroline Peek and Megan Abrahams, Department of Agriculture
26. The Leakage Calculator: A simple tool for groundwater recharge assessment, Paul Raper, Department of Agriculture
27. The cost of Salinity Calculator â your tool to assessing the profitability of salinity management options, Richard OâDonnell and Trevor Lacey, Department of Agriculture
28. Climate decision support tools, Meredith Fairbanks and David Tennant, Department of Agriculture
29. Horses for courses â using the best tools to manage climate risk, Cameron Weeks, Mingenew-Irwin Group/Planfarm and Richard Quinlan, Planfarm Agronomy
30. Use of seasonal outlook for making N decisions in Merredin, Meredith Fairbanks and Alexandra Edward, Department of Agriculture
31. Forecasts and profits, Benefits or bulldust? Chris Carter and Doug Hamilton, Department of Agriculture
32. A tool to estimate fixed and variable header and tractor depreciation costs, Peter Tozer, Department of Agriculture
33. Partners in grain: âPutting new faces in new placesâ, Renaye Horne, Department of Agriculture
34. Results from the Grower group Alliance, Tracey Gianatti, Grower Group Alliance
35. Local Farmer Group Network â farming systems research opportunities through local groups, Paul Carmody, Local Farmer Group Network
GREENHOUSE GAS AND CLIMATE CHANGE
36. Changing rainfall patterns in the grainbelt, Ian Foster, Department of Agriculture
37. Vulnerability of broadscale agriculture to the impacts of climate change, Michele John, CSIRO (formerly Department of Agriculture) and Ross George, Department of Agriculture
38. Impacts of climate change on wheat yield at Merredin, Imma Farré and Ian Foster, Department of Agriculture
39. Climate change, land use suitability and water security, Ian Kininmonth, Dennis van Gool and Neil Coles, Department of Agriculture
40. Nitrous oxide emissions from cropping systems, Bill Porter, Department of Agriculture, Louise Barton, University of Western Australia
41. The potential of greenhouse sinks to underwrite improved land management in Western Australia, Richard Harper and Peter Ritson, CRC for Greenhouse Accounting and Forest Products Commission, Tony Beck, Tony Beck Consulting Services, Chris Mitchell and Michael Hill, CRC for Greenhouse Accounting
42. Removing uncertainty from greenhouse emissions, Fiona Barker-Reid, Will Gates, Ken Wilson and Rob Baigent, Department of Primary Industries - Victoria and CRC for Greenhouse Accounting (CRCGA), and Ian Galbally, Mick Meyer and Ian Weeks, CSIRO Atmospheric Research and CRCGA
43. Greenhouse in Agriculture Program (GIA), Traci Griffin, CRC for Greenhouse Accounting
44. Grains Greenhouse Accounting framework, D. Rodriguez, M. Probust, M. Meyers, D. Chen, A. Bennett, W. Strong, R. Nussey, I. Galbally and M. Howden
CONTACT DETAILS FOR PRINCIPAL AUTHOR
2018 Research & Innovation Day Program
A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1005/thumbnail.jp
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