395 research outputs found
Effects of transport on fecal glucocorticoid levels in captive-bred cotton-top tamarins (Saguinus oedipus)
The relocation of animals can induce stress when animals are placed in novel environmental conditions. The movement of captive animals among facilities is common, especially for non-human primates used in research. The stress response begins with the activation of the hypothalamic-pituitary-adrenal (HPA) axis which results in the release of glucocorticoid hormones (GC), which at chronic levels could lead to deleterious physiological effects. There is a substantial body of data concerning GC levels affecting reproduction, and rank and aggression in primates. However, the effect of transport has received much less attention. Fecal samples from eight (four male and four female) captive-bred cotton-top tamarins (Saguinus oedipus) were collected at four different time points (two pre-transport and two post-transport). The fecal samples were analyzed using an immunoassay to determine GC levels. A repeated measures analysis of variance (ANOVA) demonstrated that GC levels differed among transport times (p = 0.009), but not between sexes (p = 0.963). Five of the eight tamarins exhibited an increase in GC levels after transport. Seven of the eight tamarins exhibited a decrease in GC levels from three to six days post-transport to three weeks post-transport. Most values returned to pre-transport levels after three weeks. The results indicate that these tamarins experienced elevated GC levels following transport, but these increases were of short duration. This outcome would suggest that the negative effects of elevated GC levels were also of short duration
Skeletal Muscle Sorbitol Levels in Diabetic Rats with and without Insulin Therapy and Endurance Exercise Training
Sorbitol accumulation
is postulated to play a role in skeletal muscle
dysfunction associated with diabetes. The
purpose of this study was to determine the
effects of insulin and of endurance exercise on
skeletal muscle sorbitol levels in
streptozotocin-induced diabetic rats. Rats were
assigned to one experimental group (control
sedentary, control exercise, diabetic sedentary,
diabetic exercise, diabetic sedentary
no-insulin). Diabetic rats received daily
subcutaneous insulin. The exercise-trained rats
ran on a treadmill (1 hour, 5X/wk, for
12 weeks). Skeletal muscle sorbitol levels
were the highest in the diabetic sedentary
no-insulin group. Diabetic sedentary rats
receiving insulin had similar sorbitol levels to
control sedentary rats. Endurance exercise did
not significantly affect sorbitol levels. These
results indicate that insulin treatment lowers
sorbitol in skeletal muscle; therefore sorbitol
accumulation is probably not related to muscle
dysfunction in insulin-treated diabetic
individuals. Endurance exercise did not
influence intramuscular sorbitol values as
strongly as insulin
Validation of Phonon Physics in the CDMS Detector Monte Carlo
The SuperCDMS collaboration is a dark matter search effort aimed at detecting
the scattering of WIMP dark matter from nuclei in cryogenic germanium targets.
The CDMS Detector Monte Carlo (CDMS-DMC) is a simulation tool aimed at
achieving a deeper understanding of the performance of the SuperCDMS detectors
and aiding the dark matter search analysis. We present results from validation
of the phonon physics described in the CDMS-DMC and outline work towards
utilizing it in future WIMP search analyses.Comment: 6 Pages, 5 Figures, Proceedings of Low Temperature Detectors 14
Conferenc
Analysis of the low-energy electron-recoil spectrum of the CDMS experiment
We report on the analysis of the low-energy electron-recoil spectrum from the
CDMS II experiment using data with an exposure of 443.2 kg-days. The analysis
provides details on the observed counting rate and possible background sources
in the energy range of 2 - 8.5 keV. We find no significant excess in the
counting rate above background, and compare this observation to the recent DAMA
results. In the framework of a conversion of a dark matter particle into
electromagnetic energy, our 90% confidence level upper limit of 0.246
events/kg/day at 3.15 keV is lower than the total rate above background
observed by DAMA by 8.9. In absence of any specific particle physics
model to provide the scaling in cross section between NaI and Ge, we assume a
Z^2 scaling. With this assumption the observed rate in DAMA differs from the
upper limit in CDMS by 6.8. Under the conservative assumption that the
modulation amplitude is 6% of the total rate we obtain upper limits on the
modulation amplitude a factor of ~2 less than observed by DAMA, constraining
some possible interpretations of this modulation.Comment: 4 pages, 3 figure
Search for inelastic dark matter with the CDMS II experiment
Results are presented from a reanalysis of the entire five-tower data set
acquired with the Cryogenic Dark Matter Search (CDMS II) experiment at the
Soudan Underground Laboratory, with an exposure of 969 kg-days. The analysis
window was extended to a recoil energy of 150 keV, and an improved
surface-event background-rejection cut was defined to increase the sensitivity
of the experiment to the inelastic dark matter (iDM) model. Three dark matter
candidates were found between 25 keV and 150 keV. The probability to observe
three or more background events in this energy range is 11%. Because of the
occurrence of these events the constraints on the iDM parameter space are
slightly less stringent than those from our previous analysis, which used an
energy window of 10-100 keV.Comment: 10 pages, 10 figures, minor changes to match published version,
conclusion unchange
The level-1 trigger for the SuperCDMS experiment at SNOLAB
The SuperCDMS SNOLAB dark matter search experiment aims to be sensitive to energy depositions down to Script O(1 eV). This imposes requirements on the resolution, signal efficiency, and noise rejection of the trigger system. To accomplish this, the SuperCDMS level-1 trigger system is implemented in an FPGA on a custom PCB. A time-domain optimal filter algorithm realized as a finite impulse response filter provides a baseline resolution of 0.38 times the standard deviation of the noise, , and a 99.9% trigger efficiency for signal amplitudes of 1.1 in typical noise conditions. Embedded in a modular architecture, flexible trigger logic enables reliable triggering and vetoing in a dead-time-free manner for a variety of purposes and run conditions. The trigger architecture and performance are detailed in this article
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