5 research outputs found
Breast support garments are ineffective at reducing breast motion during an aqua aerobics jumping exercise
The buoyant forces of water during aquatic exercise may provide a form of ‘natural’ breast support and help to minimise breast motion and alleviate exercise induced breast pain. Six larger-breasted females performed standing vertical land and water-based jumps, whilst wearing three breast support conditions. Underwater video cameras recorded the motion of the trunk and right breast. Trunk and relative breast kinematics were calculated as well as exercised induced breast pain scores. Key results showed that the swimsuit and sports bra were able to significantly reduce the superioinferior breast range of motion by 0.04 and 0.05 m, respectively, and peak velocity by 0.23 and 0.33 m/s, respectively, during land-based jumping when compared to the bare-breasted condition, but were ineffective at reducing breast kinematics during water-based jumping. Furthermore, the magnitude of the swimsuit superioinferior breast range of motion during water-based jumping was significantly greater than land-based jumping (0.13 m and 0.06 m), yet there were no significant differences in exercise induced breast pain, thus contradicting previously published relationships between these parameters on land. Furthermore, the addition of an external breast support garment was able to reduce breast kinematics on land but not in water, suggesting the swimsuit and sports bras were ineffective and improvements in swimwear breast support garments may help to reduce excessive breast motion during aqua aerobic jumping exercises
Long-term history and synchrony of mountain pine beetle outbreaks in lodgepole pine forests
Aim: A subcontinental-scale outbreak of mountain pine beetle (MPB; Dendroctonus ponderosae) has affected millions of hectares of forest in the western USA and Canada over the past 15 years. Little research has examined the long-term and broad-scale history of MPB outbreaks, which is necessary to provide a baseline for comparing current and future outbreak extents. We examine the long-term history of MPB outbreaks in western Colorado, and analyse the synchrony of previous outbreaks across western North America. Location: Western Colorado for tree-ring analysis; western North America for comparative analysis. Methods: We used dendroecological methods to reconstruct the history of MPB outbreaks since the 1700s in lodgepole pine (Pinus contorta) forests in Colorado. We then combined these new records with previously published data on MPB outbreaks to examine the historical synchrony of outbreaks across western North America. Results: The tree-ring record indicated that multiple cross-site MPB outbreaks occurred in Colorado lodgepole pine forests, initiating c. 1760s, 1780s, 1820s-1830s, 1860s, 1910s, 1960s and 1980s. Comparative analysis indicated that these outbreak dates coincide with documented and reconstructed MPB outbreaks in British Columbia, Colorado, Idaho, Montana, Wyoming and Utah. Main conclusions: Several subcontinental-scale MPB outbreaks have occurred in lodgepole pine forests over the past three centuries. Although the current study does not address the intensity of past outbreaks, it does indicate that previous outbreaks appear to have been highly synchronous across western North America. The subcontinental, rather than purely local, nature of these outbreaks is important for putting recent and future outbreaks of MPB into a broader ecological context. This study presents the longest tree-ring reconstruction of MPB outbreaks in the southern Rocky Mountains available to date, as well as the first subcontinental long-term comparative analysis of MPB outbreaks in western North America
Incorporating Carbon Storage into the Optimal Management of Forest Insect Pests: A Case Study of the Southern Pine Beetle (Dendroctonus Frontalis Zimmerman) in the New Jersey Pinelands
Forest insect pest disturbance is increasing in certain areas of North America as many insect species, such as the southern pine beetle, expand their range due to a warming climate. Because insect pests are beginning to occupy forests that are managed for multiple uses and have not been managed for pests before, it is becoming increasingly important to determine how forests should be managed for pests when non-timber ecosystem services are considered in addition to traditional costs and revenues. One example of a service that is increasingly considered in forest management and that may affect forest pest management is carbon sequestration. This manuscript seeks to understand whether the incorporation of forest carbon sequestration into cost-benefit analysis of different forest pest management strategies affects the financially optimal strategy. We examine this question through a case study of the southern pine beetle (SPB) in a new area of SPB expansion, the New Jersey Pinelands National Reserve (NJPR). We utilize a forest ecology and economics model and include field data from the NJPR as well as outbreak probability statistics from previous years. We find under the majority of scenarios, incorporating forest carbon sequestration shifts the financially optimal SPB management strategy from preventative thinning toward no management or reactionary management in forest stands in New Jersey. These results contradict the current recommended treatment strategy for SPB and signify that the inclusion of multiple ecosystem services into a cost-benefit analysis may drastically alter which pest management strategy is economically optimal