optimum germination temperatures
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CitationYoung, J. A., Clements, C. D., & Jones, T. A. (2003). Germination of seeds of robust needlegrass. Journal of Range Management, 56(3), 247-250.
PublisherSociety for Range Management
JournalJournal of Range Management
AbstractRobust needlegrass (Achnatherum robustum [Vasey] Barkw.) is a native perennial that has great promise for use in erosion control, restoration, and ornamental plantings. Seed dormancy can be a problem in developing new native grass cultivars, especially in species of Achnatherum and related genera. Germination response to a wide range of constant and alternating incubation temperatures is also a key parameter in interpreting seedbed ecology of potential planting material. Our purpose was to investigate the germination of robust needlegrass at 55 constant or alternating incubation temperatures from 0 through 40 degrees C. Seeds of robust needlegrass germinate over a wide range of incubation temperatures with maximum observed germination over 75%. In terms of restoration ecology, this means that in contrast to many related grass species, severe seed dormancy is not a limiting factor in seeding technology. Optimum germination occurred with 15 to 20 degrees C warm periods alternating with 0 to 20 degrees C cool periods. The only constant temperature to produce optimum germination was 20 degrees C. The highest germination occurred at what we consider moderate seedbed temperatures, but some germination occurred at 76 to 89% of the temperature regimes tested.
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Estimation of three-dimensional temperature fields from a limited number of transient temperature measurements during hyperthermia.Roemer, R. B.; Clegg, Scott Tom.; Vincent, T. J.; Pearlstein, A. J. (The University of Arizona., 1988)In this dissertation, a new reconstruction algorithm to estimate the complete temperature field during hyperthermia is developed which relies upon a limited amount of transient measured temperature data. The predictive capabilities of this new algorithm are then systematically studied; first using one-dimensional simulated treatments, then using three-dimensional simulated treatments, and finally applying it to hyperthermia treatments of normal canine thighs. It was found that this new algorithm predicts the complete temperature fields more accurately and robustly than the steady-state approach. In particular, it can better predict the complete temperature fields in situations where the number of unknown blood perfusion parameters are greater than the number of available temperature sensors. It was also found that the steady-state temperature field could be estimated to within 1°C if there was no measurement noise, no model mismatch, and as few as three measurement locations for seven perfusion zones. The addition of measurement noise degraded the performance of this estimation algorithm especially when the number of measurement locations was small. It was found that use of Tikhonov regularization of order zero significantly improved the performance of the algorithm and that there was an optimal choice for the regularization parameter. For the animal experiments, normal canine thighs were instrumented with one-hundred twelve thermocouples and heated to steady-state using a 6 cm planar ultrasound transducer operating at 0.5 MHz: then the power was turned off and the transient cool down temperature data was stored for later use by the reconstruction algorithm. Only a subset of the one-hundred twelve measurements was used as input to the reconstruction algorithm. The remaining measurements were used to compare the results of the reconstruction algorithm with the true temperatures. The results showed that in general the predicted perfusion and reconstructed temperature field did not change significantly as sensors were removed. However, the error was quite large for some of the situations studied particularly when only twenty-seven piecewise constant regions of perfusion were used. Increasing the number of perfusion regions reduced this error suggesting that model mismatch had contributed significantly to the error.
Esophageal Temperature Probes in Targeted Temperature ManagementDeBoe, Joseph C.; Cannon, Chelsea; Trinidad, David R.; Przybyl, Heather (The University of Arizona., 2021)Purpose: This DNP quality improvement project aimed to increase intent to change practice among nurses in the medical intensive care unit regarding temperature monitoring in patients undergoing targeted temperature management (TTM) after a cardiac arrest.Background: Although many different methods of core temperature have been used to monitor temperature in patients undergoing TTM, esophageal is most closely related to pulmonary artery catheter. Pulmonary artery catheters most accurately represent temperatures in the brain. Cooling a patient after a cardiac arrest decreases metabolic needs of the brain, stops further cell death in the brain after lack of oxygen, and decreases inflammation in the brain. Methods Design: An email was sent to nurses in the Medical Intensive Care Unit (MICU) with a link to educational material and a post-learning survey. Optional in-person rounding was provided twice on the day shift and twice on the night shift. Setting: Banner University Medical Center-Phoenix, a 746-bed not-for-profit hospital in Phoenix, Arizona, Banner Health’s flagship hospital. The project’s focus was in the 54-bed medical intensive care unit (MICU). Participants: Participants included core staff nurses in the MICU, and participation was voluntary. The link was sent out to approximately100 nurses, with sixteen nurses responding. Measurements: Six knowledge retention questions were included in the survey. Four questions used the Likert scale on how they felt about the education and their intent to change practice. One question was regarding the length of time as a nurse, and one question was if they had their Critical Care Registered Nurse (CCRN) certification. There was also one open-ended question regarding barriers to implementation. Results: The results showed that nurses agreed and strongly agreed that the education was beneficial, and they had an increase in intent to change practice. The results also showed no statistically significant difference incorrect answers when comparing CCRN nurses to non-CCRN nurses, no statistically significant difference in years of nursing, and correct answers. Conclusions: Although the sample size was small, education on esophageal temperature probes increased the intent to change practice among nurses in the MICU.