CHANDRA Observations of X-ray Jet Structure on kpc to Mpc Scales

With its exquisite spatial resolution of better than 0.5 arcsecond, the Chandra observatory is uniquely capable of resolving and studying the spatial structure of extragalactic X-ray jets on scales of a few to a few hundred kilo-parsec. Our analyses of four recent Chandra images of quasar jets interpret the X-ray emission as inverse Compton scattering of high energy electrons on the cosmic microwave background. We infer that these jets are in bulk relativistic motion, carrying kinetic powers upwards of 10^46 ergs/s to distances of hundreds of kpc, with very high efficiency.Comment: 4 pages, 3 figures, to be published in the proceedings of the Bologna jet workshop, "The Physics of Relativistic Jets in the CHANDRA and XMM Era.

Guest Editors’ Introduction On Understanding Ethical Behavior and Decision Making

Behavioral ethics is an emerging field that takes an empirical, social scientific approach to the study of business ethics. In this special issue, we include six articles that fall within the domain of behavioral ethics and that focus on three themes—moral awareness, ethical decision making, and reactions to unethical behavior. Each of the articles sheds additional light on the specific issues addressed. However, we hope this special issue will have an impact beyond that of the new insights offered in these articles, by stimulating evenmore research in this burgeoning field

National Beef Cattle Genetic Evaluation

Use of artificial insemination permits some bulls to have offspring evaluated in more than one herd. Such bulls serve as benchmarks for comparison or links between herds. For some breeds, sufficient links exist between herds that current technology may provide valid genetic comparisons between cattle from different herds, as well as within-herd comparisons. The current industry standard expression for reporting relative genetic merit of beef cattle in national evaluations is expected progeny difference (EPD). The EPD for a sire represents the expected difference in performance of a sire’s offspring when compared t o the average offspring performance of all sires evaluated. A corresponding accuracy value, reflecting the amount of information (pedigree performance, individual performance, offspring performance, etc.) on which the EPD value is based, is generally reported with each EPD value. Expected progeny difference values can be calculated not only for bulls listed in sire summaries, but also for cows, young bulls and even planned matings. EPDs for nonparents generally have low accuracy values compared to EPDs for parents. generally have low accuracy values compared t o EPDs for parents

Interpreting Experimental Results

A typical experimental format involves evaluating the response caused by application of different treatments to experimental subjects (animals, carcasses pens, pastures, etc.). The effect of a given treatment might be evaluated by comparison t o a control group or to one or more other treatment groups. However, a problem with animal research (and other types as well) is that variation not due to treatments often exists among experimental subjects

Incorporation of Density Matrix Wavefunctions in Monte Carlo Simulations: Application to the Frustrated Heisenberg Model

We combine the Density Matrix Technique (DMRG) with Green Function Monte Carlo (GFMC) simulations. The DMRG is most successful in 1-dimensional systems and can only be extended to 2-dimensional systems for strips of limited width. GFMC is not restricted to low dimensions but is limited by the efficiency of the sampling. This limitation is crucial when the system exhibits a so-called sign problem, which on the other hand is not a particular obstacle for the DMRG. We show how to combine the virtues of both methods by using a DMRG wavefunction as guiding wave function for the GFMC. This requires a special representation of the DMRG wavefunction to make the simulations possible within reasonable computational time. As a test case we apply the method to the 2-dimensional frustrated Heisenberg antiferromagnet. By supplementing the branching in GFMC with Stochastic Reconfiguration (SR) we get a stable simulation with a small variance also in the region where the fluctuations due to minus sign problem are maximal. The sensitivity of the results to the choice of the guiding wavefunction is extensively investigated. We analyse the model as a function of the ratio of the next-nearest to nearest neighbor coupling strength. We observe in the frustrated regime a pattern of the spin correlations which is in-between dimerlike and plaquette type ordering, states that have recently been suggested. It is a state with strong dimerization in one direction and weaker dimerization in the perpendicular direction.Comment: slightly revised version with added reference

Interrelationships of Heifer Milk Production and Other Biological Traits with Production Efficiency to Weaning

Interrelationships among milk production, cow-calf feed efficiency and other biological traits were evaluated on first-calf females and their calves. Production efficiency was defined as cumulative feed metabolizable energy consumed by the dam-calf pair during the year divided by calf weaning weight. Results indicated that increased levels of milk production were associated with improved production efficiency to weaning as long as calves have the genetic potential to convert the extra milk into body weight gains. However, the incremental improvement in efficiency per unit of increased milk was less for each additional unit of milk

Relationship of Sire Expected Progeny Differences to Maternal Performance of First-Calf Daughters in a Commercial Herd

Maternal performance for first calf production was evaluated in retrospect for daughters whose sires had expected progeny differences (EPDs) available from 1988 beef breed association national genetic evaluation summaries. When grouped into high EPD and low EPD groups, sire EPD group averages for actual daughter milk production and weaning weights of daughters\u27 off spring consistently ranked the same as sire group average EPDs for milk and maternal weaning weight, although differences between groups were not statistically significant

Sign Rules for Anisotropic Quantum Spin Systems

We present new and exact ``sign rules'' for various spin-s anisotropic spin-lattice models. It is shown that, after a simple transformation which utilizes these sign rules, the ground-state wave function of the transformed Hamiltonian is positive-definite. Using these results exact statements for various expectation values of off-diagonal operators are presented, and transitions in the behavior of these expectation values are observed at particular values of the anisotropy. Furthermore, the effects of sign rules in variational calculations and quantum Monte Carlo calculations are considered. They are illustrated by a simple variational treatment of a one-dimensional anisotropic spin model.Comment: 4 pages, 1 ps-figur