1,137 research outputs found
Entomogenic Climate Change
Rapidly expanding insect populations, deforestation, and global climate
change threaten to destabilize key planetary carbon pools, especially the
Earth's forests which link the micro-ecology of insect infestation to climate.
To the extent mean temperature increases, insect populations accelerate
deforestation. This alters climate via the loss of active carbon sequestration
by live trees and increased carbon release from decomposing dead trees. A
positive feedback loop can emerge that is self-sustaining--no longer requiring
independent climate-change drivers. Current research regimes and insect control
strategies are insufficient at present to cope with the present regional scale
of insect-caused deforestation, let alone its likely future global scale.
Extensive field recordings demonstrate that bioacoustic communication plays a
role in infestation dynamics and is likely to be a critical link in the
feedback loop. These results open the way to novel detection and monitoring
strategies and nontoxic control interventions.Comment: 7 pages, 1 figure; http://cse.ucdavis.edu/~chaos/chaos/pubs/ecc.ht
Insects, Trees, and Climate: The Bioacoustic Ecology of Deforestation and Entomogenic Climate Change
Accumulating observational evidence suggests an intimate connection between
rapidly expanding insect populations, deforestation, and global climate change.
We review the evidence, emphasizing the vulnerability of key planetary carbon
pools, especially the Earth's forests that link the micro-ecology of insect
infestation to climate. We survey current research regimes and insect control
strategies, concluding that at present they are insufficient to cope with the
problem's present regional scale and its likely future global scale. We propose
novel bioacoustic interactions between insects and trees as key drivers of
infestation population dynamics and the resulting wide-scale deforestation. The
bioacoustic mechanisms suggest new, nontoxic control interventions and
detection strategies
Wearing electronic performance and tracking system devices in Association Football: Potential injury scenarios and associated impact energies
In competitive association football, wearing electronic performance and tracking system (EPTS) devices was approved in 2015. Safety concerns regarding their use have been raised; however, research and understanding is limited. Recently, FIFA has taken steps to assess possible injury mechanisms associated with wearing EPTS devices. This study identifies potential injury scenarios in football and associated impact energies. EPTS device use was first surveyed by questionnaire and semi-structured interviews. Unexpected, backward falls were highlighted as potential injury scenarios. An anthropomorphic test device (ATD), wearing a mock-EPTS device, was dropped onto 3G turf. Impact energy was 142.4 ± 42.1 and 5.8 ± 4.0 J whilst wearing and not wearing mock-EPTS devices respectively. Results indicate that wearing EPTS devices markedly increased impact energy experienced at the upper-back during falls. Further investigation into possible injury mechanisms (e.g., EPTS device shape and/or contact-area) of skin laceration and/or contusion risk, is warranted
Kinetic and kinematic analysis of stamping impacts during simulated rucking in rugby union
Laceration injuries account for up to 23% of injuries in rugby union. They are frequently caused by studded footwear as a result of a player stamping onto another player during the ruck. Little is known about the kinetics and kinematics of rugby stamping impacts; current test methods assessing laceration injury risk of stud designs therefore lack informed test parameters. In this study, twelve participants stamped on an anthropomorphic test device in a one-on-one simulated ruck setting. Velocity and inclination angle of the foot prior to impact was determined from high-speed video footage. Total stamping force and individual stud force were measured using pressure sensors. Mean foot inbound velocity was 4.3 m ∙ s-1 (range 2.1 - 6.3 m ∙ s-1). Mean peak total force was 1246 N and mean peak stud force was 214 N. The total mean effective mass during stamping was 6.6 kg (range: 1.6 - 13.5 kg) and stud effective mass was 1.2 kg (range: 0.5 - 2.9 kg). These results provide representative test parameters for mechanical test devices designed to assess laceration injury risk of studded footwear for rugby union
Thermal profiles within the channel of planar gunn diodes using micro-particle sensors
The paper describes the use of a novel microparticle sensor (~3 μm diameter) and infra-red (IR) microscopy to measure the temperature profile within the active channel (typically 3 μm length and 120 μm width) of planar Gunn diodes. The method has enabled detailed temperature measurements showing an asymmetrical temperature profile along the active width of these devices. The asymmetrical temperature profile suggests a similar behaviour in the channel current density, which may contribute to the lower than expected RF output power
Flowdown of the TMT astrometry error budget(s) to the IRIS design
TMT has defined the accuracy to be achieved for both absolute and
differential astrometry in its top-level requirements documents. Because of the
complexities of different types of astrometric observations, these requirements
cannot be used to specify system design parameters directly. The TMT astrometry
working group therefore developed detailed astrometry error budgets for a
variety of science cases. These error budgets detail how astrometric errors
propagate through the calibration, observing and data reduction processes. The
budgets need to be condensed into sets of specific requirements that can be
used by each subsystem team for design purposes. We show how this flowdown from
error budgets to design requirements is achieved for the case of TMT's
first-light Infrared Imaging Spectrometer (IRIS) instrument.Comment: 8 pages, 4 figures. Proceeding of SPIE, Astronomical Telescopes and
Instrumentation 201
Identifying representative test parameters to assess skin laceration injury risk for individual studs
Skin injuries account for ∼6% of all injuries in rugby union. Skin lacerations resulting from stud–skin interactions in rugby union are frequently caused by stamping in the ruck (Oudshoorn, Driscoll, Dunn, & James, 2016 Oudshoorn, B. Y., Driscoll, H. F., Dunn, M., & James, D. (2016). Procedia Engineering, 147, 496–500.
[CrossRef], [Google Scholar]
). Stud design is regulated by World Rugby's Regulation 12, but no supporting evidence currently exists for the selected test parameters used in these standards. Ideally, mechanical tests that assess injury risk should replicate conditions observed during play (Ura & Carré, 2016 Ura, D., & Carré, M. (2016). Procedia Engineering, 147, 550–555.
[CrossRef], [Google Scholar]
). Relevant mechanical test parameters, such as foot inbound velocity, stud impact energy, inclination angle and effective mass, can be derived through biomechanical analysis of rugby stamping. However, due to human movement variability, the measured kinetics and kinematics of stamping impacts can have a large range and replicating all possible parameters within a mechanical test device is unfeasible. Identifying different stamp techniques by clustering provides an economical solution
- …