Trophic Relationships Among Caribou Calf Predators in Newfoundland

Using specially trained scat detection dogs we located fecal samples from black bear (Ursus americanus) and coyote (Canis latrans) throughout three study areas in Newfoundland, Canada, to describe these predators diet. Our sampling efforts were designed around seasons which were important to woodland caribou (Rangifer tarandus caribou) calving and resource use. We identified hairs microscopically to prey species and grouped other remains to facilitate our analysis. Bear exhibited an omnivorous diet throughout the study areas, ecological seasons and inside and outside the caribou calving grounds while coyote were limited to caribou, moose and snowshoe hare

Development and Applicability of a Mathematical Model for the High Speed Melt Spinning of Crystallizable Polymers

A mathematical model was developed to describe the high speed melt spinning behavior of crystallizable polymers. This model included the effects of acceleration, gravity and friction on the kinematics of the process, temperature and molecular orientation on the crystallization kinetics of the polymer and temperature, molecular weight and crystallinity on the elongational viscosity of the material. Experimental online diameter, birefringence and temperature profiles were obtained for a 12000 Mn nylon-66 at 2.5 gm/min spun at take-up speeds ranging from 2800 to 6600 meters/minute. These profiles were qualitatively and reasonably quantitatively in agreement with the predicted profiles. They indicated that orientation induced crystallization occurs at spinning speeds greater than 4000 meters/minute. The experimental diameter and birefringence profiles were compare to those predicted by the model using Avrami indices of 3, 2 and 1. There was a small increase in the crystalline index at the lover speeds with decreasing index. The effect of the strain hardening was more significant at the higher speeds, this being shown by decreasing the exponent in the relationship for the crystallinity on the elongational viscosity. The model was also applied to two polypropylenes of different molecular weight. There was very good agreement between the predicted and experimental diameter and birefringence profiles for both molecular weights. There was some differences in the temperature profile comparisons, but there was good agreement between the predicted and experimental temperatures and positions where the crystallization is first observed. The position and duration of the temperature plateaus were qualitatively in good agreement with those predicted. The model developed in this study indicates that high spinning speeds provide a high stress environment which increases the molecular orientation within the fiber. It is this higher molecular orientation which is the driving force for rapid crystallization on the spinline. This rapid crystallization causes a strain hardening preventing any further drawdown in the fiber diameter and an abrupt rise in the birefringence. This behavior closely corresponds to the observed spinline profiles

Assessment of multi‐criteria optimization (MCO) for volumetric modulated arc therapy (VMAT) in hippocampal avoidance whole brain radiation therapy (HA‐WBRT)

Abstract This study compared the dosimetric performance of (a) volumetric modulated arc therapy (VMAT) with standard optimization (STD) and (b) multi‐criteria optimization (MCO) to (c) intensity modulated radiation therapy (IMRT) with MCO for hippocampal avoidance whole brain radiation therapy (HA‐WBRT) in RayStation treatment planning system (TPS). Ten HA‐WBRT patients previously treated with MCO‐IMRT or MCO‐VMAT on an Elekta Infinity accelerator with Agility multileaf collimators (5‐mm leaves) were re‐planned for the other two modalities. All patients received 30 Gy in 15 fractions to the planning target volume (PTV), namely, PTV30 expanded with a 2‐mm margin from the whole brain excluding hippocampus with margin. The patients all had metastatic lesions (up to 12) of variable sizes and proximity to the hippocampus, treated with an additional 7.5 Gy from a simultaneous integrated boost (SIB) to PTV37.5. The IMRT plans used eight to eleven non‐coplanar fields, whereas the VMAT plans used two coplanar full arcs and a vertex half arc. The averaged target coverage, dose to organs‐at‐risk (OARs) and monitor unit provided by the three modalities were compared, and a Wilcoxon signed‐rank test was performed. MCO‐VMAT provided statistically significant reduction of D100 of hippocampus compared to STD‐VMAT, and Dmax of cochleas compared to MCO‐IMRT. With statistical significance, MCO‐VMAT improved V30 of PTV30 by 14.2% and 4.8%, respectively, compared to MCO‐IMRT and STD‐VMAT. It also raised D95 of PTV37.5 by 0.4 Gy compared to both MCO‐IMRT and STD‐VMAT. Improved plan quality parameters such as a decrease in overall plan Dmax and total monitor units (MU) were also observed for MCO‐VMAT. MCO‐VMAT is found to be the optimal modality for HA‐WBRT in terms of PTV coverage, OAR sparing and delivery efficiency, compared to MCO‐IMRT or STD‐VMAT

The Layer 0 Inner Silicon Detector of the D0 Experiment

This paper describes the design, fabrication, installation and performance of the new inner layer called Layer 0 (L0) that was inserted in the existing Run IIa Silicon Micro-Strip Tracker (SMT) of the D0 experiment at the Fermilab Tevatron collider. L0 provides tracking information from two layers of sensors, which are mounted with center lines at a radial distance of 16.1 mm and 17.6 mm respectively from the beam axis. The sensors and readout electronics are mounted on a specially designed and fabricated carbon fiber structure that includes cooling for sensor and readout electronics. The structure has a thin polyimide circuit bonded to it so that the circuit couples electrically to the carbon fiber allowing the support structure to be used both for detector grounding and a low impedance connection between the remotely mounted hybrids and the sensors.Comment: 28 pages, 9 figure

B Physics at the Tevatron: Run II and Beyond

This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.Comment: 583 pages. Further information on the workshops, including transparencies, can be found at the workshop's homepage: http://www-theory.lbl.gov/Brun2/. The report is also available in 2-up http://www-theory.lbl.gov/Brun2/report/report2.ps.gz or chapter-by-chapter http://www-theory.lbl.gov/Brun2/report