Visualizing Spacetime Curvature via Frame-Drag Vortexes and Tidal Tendexes II. Stationary Black Holes

When one splits spacetime into space plus time, the Weyl curvature tensor (which equals the Riemann tensor in vacuum) splits into two spatial, symmetric, traceless tensors: the tidal field $E$, which produces tidal forces, and the frame-drag field $B$, which produces differential frame dragging. In recent papers, we and colleagues have introduced ways to visualize these two fields: tidal tendex lines (integral curves of the three eigenvector fields of $E$) and their tendicities (eigenvalues of these eigenvector fields); and the corresponding entities for the frame-drag field: frame-drag vortex lines and their vorticities. These entities fully characterize the vacuum Riemann tensor. In this paper, we compute and depict the tendex and vortex lines, and their tendicities and vorticities, outside the horizons of stationary (Schwarzschild and Kerr) black holes; and we introduce and depict the black holes' horizon tendicity and vorticity (the normal-normal components of $E$ and $B$ on the horizon). For Schwarzschild and Kerr black holes, the horizon tendicity is proportional to the horizon's intrinsic scalar curvature, and the horizon vorticity is proportional to an extrinsic scalar curvature. We show that, for horizon-penetrating time slices, all these entities ($E$, $B$, the tendex lines and vortex lines, the lines' tendicities and vorticities, and the horizon tendicities and vorticities) are affected only weakly by changes of slicing and changes of spatial coordinates, within those slicing and coordinate choices that are commonly used for black holes. [Abstract is abbreviated.]Comment: 19 pages, 7 figures, v2: Changed to reflect published version (changes made to color scales in Figs 5, 6, and 7 for consistent conventions). v3: Fixed Ref

Effects of various fat sources on growth performance of finishing pigs

One hundred and twenty-eight finishing pigs averaging 124 lb were utilized to evaluate the effects of different fat sources on growth performance. Pigs were fed one of four diets containing either no added fat (control) or 4% added fat from soybean oil, coconut oil, or choice white grease. The control diet was formulated to contain 14.5 % crude protein and .66 % lysine. All fat-added diets were formulated with the same calorie:lysine ratio as the control diet. There were no differences in average daily gain between pigs fed either the control diet or diets containing added fat. Daily feed intake was reduced for pigs fed added fat from 4 to 7% compared to pigs fed no added fat, with pigs fed choice white grease having the lowest feed intake. This resulted in pigs fed choice white grease having 11% better feed efficiency compared to pigs fed no added fat. Pigs fed soybean oil exhibited a 4% improvement in feed efficiency, and those fed coconut oil were intermediate, with an 8% improvement in feed efficiency. These results indicate that 4% added fat reduces feed intake and improves feed efficiency of finishing pigs. In addition, it appears that choice white grease may be a superior fat source in finishing pig diets.; Swine Day, Manhattan, KS, November 16, 198

Covariance of Kinetic Parameter Estimators Based on Time Activity Curve Reconstructions: Preliminary Study on 1D Dynamic Imaging

We provide approximate expressions for the covariance matrix of kinetic parameter estimators based on time activity curve (TAC) reconstructions when TACs are modeled as a linear combination of temporal basis functions such as B-splines. The approximations are useful tools for assessing and optimizing the basis functions for TACs and the temporal bins for data in terms of computation and efficiency. In this paper we analyze a 1D temporal problem for simplicity, and we consider a scenario where TACs are reconstructed by penalized-likelihood (PL) estimation incorporating temporal regularization, and kinetic parameters are obtained by maximum likelihood (ML) estimation. We derive approximate formulas for the covariance of the kinetic parameter estimators using 1) the mean and variance approximations for PL estimators in (Fessler, 1996) and 2) Cramer-Rao bounds. The approximations apply to list-mode data as well as bin-mode data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85981/1/Fessler193.pd

Frame-Dragging Vortexes and Tidal Tendexes Attached to Colliding Black Holes: Visualizing the Curvature of Spacetime

When one splits spacetime into space plus time, the spacetime curvature (Weyl tensor) gets split into an "electric" part E_{jk} that describes tidal gravity and a "magnetic" part B_{jk} that describes differential dragging of inertial frames. We introduce tools for visualizing B_{jk} (frame-drag vortex lines, their vorticity, and vortexes) and E_{jk} (tidal tendex lines, their tendicity, and tendexes), and also visualizations of a black-hole horizon's (scalar) vorticity and tendicity. We use these tools to elucidate the nonlinear dynamics of curved spacetime in merging black-hole binaries.Comment: 4 pages, 5 figure

Geodatabase Development to Support Hyperspectral Imagery Exploitation

Geodatabase development for coastal studies conducted by the Naval Research Laboratory (NRL) is essential to support the exploitation of hyperspectral imagery (HSI). NRL has found that the remote sensing and mapping science community benefits from coastal classifications that group coastal types based on similar features. Selected features in project geodatabases relate to significant biological and physical forces that shape the coast. The project geodatabases help researchers understand factors that are necessary for imagery post processing, especially those features having a high degree of temporal and spatial variability. NRL project geodatabases include a hierarchy of environmental factors that extend from shallow water bottom types and beach composition to inland soil and vegetation characteristics. These geodatabases developed by NRL allow researchers to compare features among coast types. The project geodatabases may also be used to enhance littoral data archives that are sparse. This paper highlights geodatabase development for recent remote sensing experiments in barrier island, coral, and mangrove coast types

The Impact of Dormancy Breakers on Hormone Profiles, Fruit Growth and Quality in Sweet Cherry

Chemical dormancy breakers are often used to manipulate floral bud break in sweet cherry production, and their use is increasing due to unpredictable climate effects. The role of plant hormones in regulating the critical transition of floral buds from dormant to opening in deciduous trees is now emerging. By monitoring changes in endogenous hormone levels within floral buds that are undergoing the transition from dormant to the growing state in response to various cues (environmental and/or chemical inducers), we can begin to distinguish the plant hormones that are the drivers of this process. This study sought to identify key hormonal regulators of floral bud break using sweet cherry as a model and modifying timing of bud break through the application of two chemical dormancy breakers, hydrogen cyanamide (HC, Dormex®) and emulsified vegetable oil compound (EVOC, Waiken®), and to determine the effect of these chemicals on fruit growth and quality. Treatments were applied at label rates 35–40 days before estimated bud break. We found that HC-treated tree buds broke earlier, and this was associated with a significant early elevation of the cytokinins dihydrozeatin and dihydrozeatin riboside compared to the control and EVOC-treated tree buds. In contrast, changes in auxin and abscisic acid content did not appear to explain the hastened bud burst induced by hydrogen cyanamide. While HC-treated trees resulted in larger fruit, there was a higher incidence of cracked fruit and the pack-out of A-grade fruit was reduced. The increase in fruit size was attributed to the earlier flowering and hence longer growing period. Harvest assessment of fruit quality showed no treatment effect on most quality parameters, including fruit dry matter content, total soluble solids or malic acid content, but a reduction in fruit compression firmness and stem pull force in EVOC-treated trees was observed. However, all fruit still met the Australian industry fruit quality export market standards. This study offers important insights into bud hormonal activities underpinning the action of these chemical regulators; understanding bud responses is critically important to ensuring consistent and sustainable fruit tree production systems into the future. It also demonstrates that the dormancy-breaking agents HC and EVOC have no detrimental impact on fruit quality at harvest or following storage, however growers need to be aware of the potential for increased fruit cracking when earlier bud break results in a longer growing season which has the potential to increase fruit size. Further studies are required to determine the role of gibberellin in hastening bud break by dormancy breaker

Visualizing Spacetime Curvature via Frame-Drag Vortexes and Tidal Tendexes III. Quasinormal Pulsations of Schwarzschild and Kerr Black Holes

In recent papers, we and colleagues have introduced a way to visualize the full vacuum Riemann curvature tensor using frame-drag vortex lines and their vorticities, and tidal tendex lines and their tendicities. We have also introduced the concepts of horizon vortexes and tendexes and 3-D vortexes and tendexes (regions where vorticities or tendicities are large). Using these concepts, we discover a number of previously unknown features of quasinormal modes of Schwarzschild and Kerr black holes. These modes can be classified by mode indexes (n,l,m), and parity, which can be electric [(-1)^l] or magnetic [(-1)^(l+1)]. Among our discoveries are these: (i) There is a near duality between modes of the same (n,l,m): a duality in which the tendex and vortex structures of electric-parity modes are interchanged with the vortex and tendex structures (respectively) of magnetic-parity modes. (ii) This near duality is perfect for the modes' complex eigenfrequencies (which are well known to be identical) and perfect on the horizon; it is slightly broken in the equatorial plane of a non-spinning hole, and the breaking becomes greater out of the equatorial plane, and greater as the hole is spun up; but even out of the plane for fast-spinning holes, the duality is surprisingly good. (iii) Electric-parity modes can be regarded as generated by 3-D tendexes that stick radially out of the horizon. As these "longitudinal," near-zone tendexes rotate or oscillate, they generate longitudinal-transverse near-zone vortexes and tendexes, and outgoing and ingoing gravitational waves. The ingoing waves act back on the longitudinal tendexes, driving them to slide off the horizon, which results in decay of the mode's strength. (iv) By duality, magnetic-parity modes are driven in this same manner by longitudinal, near-zone vortexes that stick out of the horizon. [Abstract abridged.]Comment: 53 pages with an overview of major results in the first 11 pages, 26 figures. v2: Very minor changes to reflect published version. v3: Fixed Ref