Safety, the Preface Paradox and Possible Worlds Semantics

This paper contains an argument to the effect that possible worlds semantics renders semantic knowledge impossible, no matter what ontological interpretation is given to possible worlds. The essential contention made is that possible worlds semantic knowledge is unsafe and this is shown by a parallel with the preface paradox

Rotor blade dynamic design

The rotor dynamic design considerations are essentially limitations on the vibratory response of the blades which in turn limit the dynamic excitation of the fuselage by forces and moments transmitted to the hub. Quantities which are associated with the blade response and which are subject to design constraints are discussed. These include blade frequencies, vertical and inplane hub shear, rolling and pitching moments, and aeroelastic stability margin

Senstitivty analysis and optimization of nodal point placement for vibration reduction

A method is developed for sensitivity analysis and optimization of nodal point locations in connection with vibration reduction. A straightforward derivation of the expression for the derivative of nodal locations is given, and the role of the derivative in assessing design trends is demonstrated. An optimization process is developed which uses added lumped masses on the structure as design variables to move the node to a preselected location - for example, where low response amplitude is required or to a point which makes the mode shape nearly orthogonal to the force distribution, thereby minimizing the generalized force. The optimization formulation leads to values for added masses that adjust a nodal location while minimizing the total amount of added mass required to do so. As an example, the node of the second mode of a cantilever box beam is relocated to coincide with the centroid of a prescribed force distribution, thereby reducing the generalized force substantially without adding excessive mass. A comparison with an optimization formulation that directly minimizes the generalized force indicates that nodal placement gives essentially a minimum generalized force when the node is appropriately placed

Hybrid Atom--Photon Quantum Gate in a Superconducting Microwave Resonator

We propose a novel hybrid quantum gate between an atom and a microwave photon in a superconducting coplanar waveguide cavity by exploiting the strong resonant microwave coupling between adjacent Rydberg states. Using experimentally achievable parameters gate fidelities $> 0.99$ are possible on sub-$\mu$s timescales for waveguide temperatures below 40 mK. This provides a mechanism for generating entanglement between two disparate quantum systems and represents an important step in the creation of a hybrid quantum interface applicable for both quantum simulation and quantum information processing.Comment: 4 pages, 4 figure

Effect of Corn Processing and Reconstitution in High Grain Diets on Feedlot Performance and Carcass Characteristics of Steers and Heifers

A 167-day feedlot trial was conducted to examine the effects of corn processing and reconstitution on growth performance and carcass characteristics of feedlot cattle. Initial weights of the continental cross steers (n = 95) and heifers (n =63) were 690 and 680 Ib, respectively. Diets were 84.5% corn, 7.0% ground grass hay, 4.9% soybean meal, and 3.6% liquid supplement. The grain component of the diet was either dry whole corn (WC), dry rolled corn (RC), corn reconstituted at least 12 h before rolling (RRC), or corn reconstituted with a commercial surfactant3 at least 12 hours before rolling (CRC). Monensin and tylosin were included at 26.9 and 11 .O g/ton, respectively. Dry matter content of the WC, RC, RRC, and CRC diets were 85.62, 85.03, 80.98, and 80.96%, respectively. Dietary treatment had no effect on the feedlot performance of the steers or heifers. Yield grade (YG) was lower (P= .05) for CRC than for RRC cattle (2.96 vs 3.27). Kidney pelvic and heart fat (KPH) was lower (Pc.05) for RC (2.30%) and CRC (2.29%) than for WC (2.48%) and RRC (2.56%) cattle. KPH and YG were the only measured variable affected by dietary treatment indicating little advantage to any of the corn processing methods tested

Effect of Corn Processing and Reconstitution on the Digestibility of High Grain Diets

Twelve steers (body weight 955 Ib + 37) were allotted to a 4 x 4 Latin square design digestion trial to examine the effects of corn processing on feed utilization. The grain component of the diet was either dry whole corn (WC), dry rolled corn (RC), corn reconstituted 12 hours before rolling (RRC), or corn reconstituted with a commercial surfactant3 12 hours before rolling (CRC). Dry matter content of the WC, RC, RRC, and CRC diets were 87.91, 87.30, 82.1 9, and 82.14%, respectively. Treatment had no effect on the digestibilities of dry matter (71.00% ± 1.57), organic matter (72.22% ± 1.531, crude protein (57.54% ± 1.66), neutral detergent fiber (52.68% ± 3.071, or starch (85.67% + .98). Neutral detergent fiber digestion was affected by period, but this was not related to bulk density of the corn which ranged from 43 to 56 Ib/bu over periods. Processing did not affect dry matter intake (21.76 Ib/day ± .41), although reconstitution depressed (P \u3c .01) dry matter intake as a percentage of body weight (2.19, 2.24, 2.1 1, and 2.1496, respectively). To quantify differences in particle size, processed grain samples were separated with #5, 7, 10, and 18 mesh sieves. Mean percentages retained on a #5 mesh sieve were 85.26, 58.74, 84.27, and 83.57% for WC, RC, RRC, and CRC, respectively. Subsequent separated fractions of WC and the reconstituted treatments were similar

Grain Sources and Roughage Levels for Limited Feeding Backgrounding Programs

The effects of grain source and roughage level in limited intake feeding programs were evaluated in 622-lb steer calves. Supplemented diets were based on high moisture ear corn (HMEC), whole shelled corn (WSC) + hay to provide similar NDF to the HMEC diet, HMEC diet containing 10% hay and the WSC + hay diet formulated to contain NDF similar to HMEC + hay. Steer calves were blocked by weight and fed to achieve 2.2 Ib ADG for a 52-day period. Steers fed HMEC had higher (P\u3c.01) ADG and lower (P\u3c.01) feed/gain than WSC fed steers. Low crude protein in the hay source caused lower (P\u3c.01) crude protein in WSC diets. Lower crude protein intake could have limited steer growth. NE utilization appeared more efficient (P\u3c.05) for heavy weight block steers, reflecting NRC equation low sensitivity to modest differences in frame size. Roughage level did not affect performance and did not interact with grain source

Substitution of Rolled Barley for Whole Shelled Corn in Finishing Diets for Steers

Rolled barley was substituted for 0, 25, 50, 75 or 100% of the whole shelled corn in finishing diets fed to steers for 84 days. Increasing barley substitution resulted in a linear (P=.12) decrease in ADG and a quadratic (P\u3c.05) decrease in DM1 with no effect on feed conversion. At the termination of the study, barley substitution caused a linear reduction in carcass weight (P\u3c.01) and dressing percent (P\u3c.01). The 100% substitution of barley for corn reduced (Pc.05) the percentage of carcasses grading choice. Dietary net energy values calculated from steer weights, gain and feed intake increased linearly (P\u3c.10) as barley content of the diets increased, possibly reflecting positive associative effects. Published energy values for barley may not be suitable for least cost pricing in all feeding situations

Directional genetic differentiation and asymmetric migration

Understanding the population structure and patterns of gene flow within species is of fundamental importance to the study of evolution. In the fields of population and evolutionary genetics, measures of genetic differentiation are commonly used to gather this information. One potential caveat is that these measures assume gene flow to be symmetric. However, asymmetric gene flow is common in nature, especially in systems driven by physical processes such as wind or water currents. Since information about levels of asymmetric gene flow among populations is essential for the correct interpretation of the distribution of contemporary genetic diversity within species, this should not be overlooked. To obtain information on asymmetric migration patterns from genetic data, complex models based on maximum likelihood or Bayesian approaches generally need to be employed, often at great computational cost. Here, a new simpler and more efficient approach for understanding gene flow patterns is presented. This approach allows the estimation of directional components of genetic divergence between pairs of populations at low computational effort, using any of the classical or modern measures of genetic differentiation. These directional measures of genetic differentiation can further be used to calculate directional relative migration and to detect asymmetries in gene flow patterns. This can be done in a user-friendly web application called divMigrate-online introduced in this paper. Using simulated data sets with known gene flow regimes, we demonstrate that the method is capable of resolving complex migration patterns under a range of study designs.Comment: 25 pages, 8 (+3) figures, 1 tabl