356 research outputs found
STABILIZATION OF EXTENDED DIFFUSE OPTICAL SPECTROSCOPY MEASUREMENTS ON IN VIVO HUMAN SKELETAL MUSCLE DURING DYNAMIC EXERCISE
This research investigates various applications of diffuse correlation spectroscopy (DCS) on in-vivo human muscle tissue, both at rest and during dynamic exercise. Previously suspected muscle tissue relative blood flow (rBF) baseline shift during extended measurement with DCS and DCS-Near infrared spectroscopy (NIRS) hybrid optical systems are verified, quantified, and resolved by redesign of optical probe and alteration in optical probe attachment methodology during 40 minute supine bed rest baseline measurements. We then translate previously developed occlusion techniques, whereby rBF and relative oxygen consumption rV̇O2 are calibrated to initial resting absolute values by use of a venous occlusion (VO) and arterial occlusion (AO) protocol, respectively, to the lower leg (gastrocnemius) and these blood flows are cross validated at rest by strain gauge venous plethysmography (SGVP). Methods used to continuously observe 0.5Hz, 30% maximum voluntary isometric contraction (MVIC) plantar flexion exercise via dynamometer are adapted for our hybrid DCS-Imagent diffuse optical flow-oximeter in the medial gastrocnemius. We obtain healthy control muscle tissue hemodynamic profiles for key parameters BF, V̇O2, oxygen saturation (StO2), deoxyhemoglobin, oxyhemoglobin, and total hemoglobin concentrations ([Hb], [HbO2], and THC respectively), as well as systemic mean arterial pressure (MAP) and pulse rate (PR), at rest, during VO/AO, during dynamic exercise and during 15 minute recovery periods. Next, we began investigation of muscle tissue hemodynamic disease states by performing a feasibility pilot study using limited numbers of controls and peripheral arterial disease (PAD) patients using the translated methods/techniques to determine the ability of our technology to assess differences in these populations
The strength of party brands means that fighting for marginal districts is now much more expensive for candidates
Concern about party polarization in Congress is by no means new, but using new research, Henry A. Kim and Brad L. LeVeck argue that it can also lead to more expensive campaigns for incumbents in marginal districts. They maintain that while strong party branding makes it much easier for candidates to communicate their ideology in districts that like the party, in competitive races, incumbent candidates must work hard, and spend more, to present more information to show that they are closer to their district’s preferences than those of their party
Variables in the Southern Polar Region Evryscope 2016 Dataset
The regions around the celestial poles offer the ability to find and
characterize long-term variables from ground-based observatories. We used
multi-year Evryscope data to search for high-amplitude (~5% or greater)
variable objects among 160,000 bright stars (Mv < 14.5) near the South
Celestial Pole. We developed a machine learning based spectral classifier to
identify eclipse and transit candidates with M-dwarf or K-dwarf host stars -
and potential low-mass secondary stars or gas giant planets. The large
amplitude transit signals from low-mass companions of smaller dwarf host stars
lessens the photometric precision and systematics removal requirements
necessary for detection, and increases the discoveries from long-term
observations with modest light curve precision. The Evryscope is a robotic
telescope array that observes the Southern sky continuously at 2-minute
cadence, searching for stellar variability, transients, transits around exotic
stars and other observationally challenging astrophysical variables. In this
study, covering all stars 9 < Mv < 14.5, in declinations -75 to -90 deg, we
recover 346 known variables and discover 303 new variables, including 168
eclipsing binaries. We characterize the discoveries and provide the amplitudes,
periods, and variability type. A 1.7 Jupiter radius planet candidate with a
late K-dwarf primary was found and the transit signal was verified with the
PROMPT telescope network. Further followup revealed this object to be a likely
grazing eclipsing binary system with nearly identical primary and secondary K5
stars. Radial velocity measurements from the Goodman Spectrograph on the 4.1
meter SOAR telescope of the likely-lowest-mass targets reveal that six of the
eclipsing binary discoveries are low-mass (.06 - .37 solar mass) secondaries
with K-dwarf primaries, strong candidates for precision mass-radius
measurements.Comment: 32 pages, 17 figures, accepted to PAS
Pesticide application technology in the 21st century
Since 1996, glyphosate has been the predominant herbicide used postemergence for weed control in corn, soybean and cotton in the United States. Because of that, glyphosate-resistant weeds have become increasingly more prevalent in glyphosate-resistant crops which have forced many growers to use other herbicides. Herbicide programs that relied primarily on glyphosate for weed control often used rates as low as 5 gallon/acre (GPA). The other herbicides being used in row crops often require a higher carrier volume according to the label when compared to glyphosate which can be burdensome to the applicator, requiring the transport of more water, more refills and more potential of mixing errors. Additionally, there is growing concern about off-target movement of pesticides and what can be done to mitigate pesticide drift. Both drift and efficacy can be affected by spray quality and application decisions such as nozzle selection, operating pressure and components of the spray solution
Effects of Varying Levels of Silage Inclusion and Brown Midrib Corn Silage on Finishing Performance of Steers
A 2 × 3 factorial finishing study evaluated traditional or brown midrib corn silage fed at three inclusions in finishing diets. Silage inclusion was 15%, 45%, or 75% inclusion (DM basis) for 70 days followed by 15% inclusion for the remainder of the finishing phase. Cattle were ultrasounded twice to calculate backfat deposition rate for a target backfat of 0.55 inches, as cattle were fed longer if silage inclusion was 45 or 75/15%. Cattle fed 45% or 75/15% silage inclusion had greater final body weight (BW) and days on feed, but higher feed:gain (F:G) than cattle fed 15% silage. Daily gain was greatest for cattle fed 15% silage, but not different between cattle fed 45% and 75/15% treatments. Cattle fed 45% and 75/15% silage had greater final hot carcass weight (HCW) and longissimus muscle (LM) area than 15% but fed for 28 additional days. Dry matter intake was greater for cattle fed brown midrib (bm3) silage but gain or F:G were not affected. Backgrounding cattle on a low energy diet followed by a high energy diet resulted in similar growth performance and carcass endpoint as cattle fed a consistent inclusion of silage throughout the entirety of the feeding period. Feeding cattle 45% or 75/15% silage resulted in larger carcass weights and more days on feed (DOF) than cattle fed 15% silage for the finishing period. This resulted in greater returns for cattle fed 45% and 75/15% silage diet as compared to cattle fed a high energy 15% silage diet throughout the feeding period
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