2,759 research outputs found
Blood lactate clearance during active recovery after an intense running bout depends on the intensity of the active recovery
High-intensity exercise training contributes to the production and accumulation of blood lactate, which is cleared by active recovery. However, there is no commonly agreed intensity or mode for clearing accumulated blood lactate. We studied clearance of accumulated blood lactate during recovery at various exercise intensities at or below the lactate threshold after high-intensity interval runs that prompted lactate accumulation. Ten males repeated 5-min running bouts at 90% of maximal oxygen uptake ([Vdot]O2max), which increased blood lactate concentration from 1.0 ± 0.1 to 3.9 ± 0.3 mmol · l-1. This was followed by recovery exercises ranging from 0 to 100% of lactate threshold. Repeated blood lactate measurements showed faster clearance of lactate during active versus passive recovery, and that the decrease in lactate was more rapid during higher (60-100% of lactate threshold) than lower (0-40% of lactate threshold) (P < 0.05) intensities. The more detailed curve and rate analyses showed that active recovery at 80-100% of lactate threshold had shorter time constants for 67% lactate clearance and higher peak clearance rates than 40% of lactate threshold or passive recovery (P < 0.05). Finally, examination of self-regulated intensities showed enhanced lactate clearance during higher versus lower intensities, further validating the intensity dependence of clearance of accumulated blood lactate. Therefore, active recovery after strenuous exercise clears accumulated blood lactate faster than passive recovery in an intensity-dependent manner. Maximum clearance occurred at active recovery close to the lactate threshold
OT 060420: A Seemingly Optical Transient Recorded by All-Sky Cameras
We report on a ~5th magnitude flash detected for approximately 10 minutes by
two CONCAM all-sky cameras located in Cerro Pachon - Chile and La Palma -
Spain. A third all-sky camera, located in Cerro Paranal - Chile did not detect
the flash, and therefore the authors of this paper suggest that the flash was a
series of cosmic-ray hits, meteors, or satellite glints. Another proposed
hypothesis is that the flash was an astronomical transient with variable
luminosity. In this paper we discuss bright optical transient detection using
fish-eye all-sky monitors, analyze the apparently false-positive optical
transient, and propose possible causes to false optical transient detection in
all-sky cameras.Comment: 7 figures, 3 tables, accepted PAS
Opportunities for Improving Livestock Production with e-Management Systems
There is increased interest in hardware and software that can support e-Management for grassland-based livestock industries. Managers of grazing livestock were early adopters of radio frequency identification (RFID) technologies automatically monitoring individual animal performance. Recent developments of remote sensing, automated individual recording and management, location based systems, improved data transfer and technologies that can be used in more extensive grazing systems are providing new opportunities for the development of e-Management systems. There is a need for better data integration and systems that can provide the best available information to enable better decision-making. For greater industry adoption of more integrated e-Management systems, there needs to be a clear economic value. With increased on farm monitoring and the expansion of digital data sources, grazing livestock production systems have the opportunity to expand production efficiency through the implementation of e-Management
Spitzer Space Telescope spectral observations of AGB stars in the Fornax dwarf spheroidal galaxy
We have observed five carbon-rich AGB stars in the Fornax dwarf spheroidal
(dSph) galaxy, using the Infrared Spectrometer on board the Spitzer Space
Telescope. The stars were selected from a near-infrared survey of Fornax and
include the three reddest stars, with presumably the highest mass-loss rates,
in that galaxy. Such carbon stars probably belong to the intermediate-age
population (2-8 Gyr old and metallicity of [Fe/H] -1) of Fornax. The primary
aim of this paper is to investigate mass-loss rate, as a function of luminosity
and metallicity, by comparing AGB stars in several galaxies with different
metallicities. The spectra of three stars are fitted with a radiative transfer
model. We find that mass-loss rates of these three stars are 4-7x10^-6 Msun
yr-1. The other two stars have mass-loss rates below 1.3x10^-6 Msun yr-1. We
find no evidence that these rates depend on metallicity, although we do suggest
that the gas-to-dust ratio could be higher than at solar metallicity, in the
range 240 to 800. The C2H2 bands are stronger at lower metallicity because of
the higher C/O ratio. In contrast, the SiC fraction is reduced at low
metallicity, due to low silicon abundance. The total mass-loss rate from all
known carbon-rich AGB stars into the interstellar medium of this galaxy is of
the order of 2x10^-5 Msun yr-1. This is much lower than that of the dwarf
irregular galaxy WLM, which has a similar visual luminosity and metallicity.
The difference is attributed to the younger stellar population of WLM. The
suppressed gas-return rate to the ISM accentuates the difference between the
relatively gas-rich dwarf irregular and the gas-poor dwarf spheroidal galaxies.
Our study will be useful to constrain gas and dust recycling processes in low
metallicity galaxies.Comment: MNRAS accepte
Cost-Effectiveness of Skin Surveillance Through a Specialized Clinic for Patients at High Risk of Melanoma
Purpose
Clinical guidelines recommend that people at high risk of melanoma receive regular surveillance to
improve survival through early detection. A specialized High Risk Clinic in Sydney, Australia was
found to be effective for this purpose; however, wider implementation of this clinical service requires evidence of cost-effectiveness and data addressing potential overtreatment of suspicious
skin lesions.
Patients and Methods
A decision-analytic model was built to compare the costs and benefits of specialized surveillance
compared with standard care over a 10-year period, from a health system perspective. A high-risk
standard care cohort was obtained using linked population data, comprising the Sax Institute’s 45
and Up cohort study, linked to Medicare Benefits Schedule claims data, the cancer registry, and
hospital admissions data. Benefits were measured in quality-adjusted life-years gained. Sensitivity
analyses were undertaken for all model parameters.
Results
Specialized surveillance through the High Risk Clinic was both less expensive and more effective
than standard care. The mean saving was A5,564 to $8,092) per patient, and the
mean quality-adjusted life-year gain was 0.31 (95% CI, 0.27 to 0.35). The main drivers of the differences were detection of melanoma at an earlier stage resulting in less extensive treatment and
a lower annual mean excision rate for suspicious lesions in specialized surveillance (0.81; 95% CI,
0.72 to 0.91) compared with standard care (2.55; 95% CI, 2.34 to 2.76). The results were robust
when tested in sensitivity analyses.
Conclusion
Specialized surveillance was a cost-effective strategy for the management of individuals at high risk
of melanoma. There were also fewer invasive procedures in specialized surveillance compared with
standard care in the community
The significance of heat transport by shallow fluid flow at an active plate boundary: the Southern Alps, New Zealand
Fluid flow can influence fault behavior. Here we quantify the role of groundwater heat advection in establishing the thermal structure of the Alpine Fault, a major tectonic boundary in southern New Zealand that accommodates most of the motion between the Australian and Pacific Plates. Convergence on the Alpine Fault has rapidly uplifted the Southern Alps, resulting in high geothermal gradients and a thin seismogenic zone. A new equilibrium temperature profile from the 818-m-deep Deep Fault Drilling Project 2B borehole has been interrogated using one-dimensional analytical models of fluid and rock advection. Models indicate a total heat flux of 720-mW m2 results from groundwater flow with Darcy velocities approximating to 7.8 × 1010 m s1. Groundwaters advect significantly more heat than rock advection in the shallow orogen (<6-km depth) and are the major control on the subsurface temperature field
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