Constraining cosmological models with cluster power spectra

Using extensive N-body simulations we estimate redshift space power spectra of clusters of galaxies for different cosmological models (SCDM, TCDM, CHDM, Lambda-CDM, OCDM, BSI, tau-CDM) and compare the results with observational data for Abell-ACO clusters. Our mock samples of galaxy clusters have the same geometry and selection functions as the observational sample which contains 417 clusters of galaxies in a double cone of galactic latitude |b| > 30 degrees up to a depth of 240 Mpc/h. The power spectrum has been estimated for wave numbers k in the range 0.03 < k k_max ~ 0.05 h/Mpc the power spectrum of the Abell-ACO clusters has a power-law shape, P(k)\propto k^n, with n ~ -1.9, while it changes sharply to a positive slope at k < k_max. By comparison with the mock catalogues SCDM, TCDM (n=0.9), and also OCDM with Omega_0 = 0.35 are rejected. Better agreement with observation can be found for the Lambda-CDM model with Omega_0 = 0.35 and h = 0.7 and the CHDM model with two degenerate neutrinos and Omega_HDM = 0.2 as well as for a CDM model with broken scale invariance (BSI) and the tau-CDM model. As for the peak in the Abell-ACO cluster power spectrum, we find that it does not represent a very unusual finding within the set of mock samples extracted from our simulations.Comment: LaTeX, 27 pages, 8 figures (EPS). Revised version (title changed, CHDM model added, discussion expanded). Accepted by New

Achieving maximum unit Mission capability: an impact study of system availability, proficiency, cost, and OPTEMPO

MBA Professional ReportThe highest level of Unit Mission Capability is the ultimate goal of any unit commander. Members of the user community, especially unit commanders, must be aware of the factors that influence their war fighting capability. Understanding these factors and their relationships, coupled with the implementation of specific strategies, can facilitate maximizing Unit Mission Capability. This is the primary focus of this project. This report will provide aviation unit commanders and user representatives with a clear explanation and demonstration of the variables that influence a commanderb2ss ability to improve Unit Mission Capability. The tool demonstrated in this report is the Availability, Proficiency, Cost, and Operational Tempo (OPTEMPO) model for assessing and maximizing Unit Mission Capability. The user community must understand how competing funding requirements influences their ability to train and maintain a strong fighting force. Current DOD funding levels will decline in the near future. It will become more and more difficult to achieve the desired state of Unit Mission Capability. Users must implement strategic cost saving initiatives to preserve our war fighting capability. .http://archive.org/details/achievingmaximum1094510000US Army (USA) author.Approved for public release; distribution is unlimited

Large-scale structure formation for power spectra with broken scale invariance

We have simulated the formation of large-scale structure arising from COBE-normalized spectra computed by convolving a primordial double-inflation perturbation spectrum with the CDM transfer function. Due to the broken scale invariance ('BSI') characterizing the primordial perturbation spectrum, this model has less small-scale power than the (COBE-normalized) standard CDM model. The particle-mesh code (with $512^3$ cells and $256^3$ particles) includes a model for thermodynamic evolution of baryons in addition to the usual gravitational dynamics of dark matter. It provides an estimate of the local gas temperature. In particular, our galaxy-finding procedure seeks peaks in the distribution of gas that has cooled. It exploits the fact that ``cold" particles trace visible matter better than average and thus provides a natural biasing mechanism. The basic picture of large-scale structure formation in the BSI model is the familiar hierarchical clustering scenario. We obtain particle in cell statistics, the galaxy correlation function, the cluster abundance and the cluster-cluster correlation function and statistics for large and small scale velocity fields. We also report here on a semi-quantitative study of the distribution of gas in different temperature ranges. Based on confrontation with observations and comparison with standard CDM, we conclude that the BSI scenario could represent a promising modification of the CDM picture capable of describing many details of large-scale structure formation.Comment: 15 pages, Latex using mn.sty, uuencoded compressed ps-file with 15 figures by anonymous ftp to ftp://ftp.aip.de/incoming/mueller/bsi.u

Bilingual, digital, audio-visual training modules improve technical knowledge of feedlot and dairy workers

Two studies were conducted to determine the effectiveness of digital multimedia modules as training tools for animal care workers. Employees at a commercial feedlot (n = 17) and a commercial dairy (n = 10) were asked to independently complete a 10-question quiz prior to and following viewing of training modules. Module topics in the feedlot were proper handling of non-ambulatory animals and humane methods of euthanasia; modules were administered to the workers, as a group, in either English (n = 7) or Spanish (N = 10), depending on previously indicated worker preference. Modules addressing dairy cattle health practices and dairy cattle handling were presented to the dairy care workers who had a preference for learning in either English (n = 7) or Spanish (n = 3). For feedlot workers, post-test scores were improved by 28% after viewing the modules compared to pre-test scores (74% vs. 58%; P 0.30) between language, topic, and between-test variation, indicating that the modules were equally effective at information delivery to both audiences in both languages. For the dairy workers, test scores improved by 27% from pre-viewing to post-viewing (73% vs. 92%; P < 0.01); there was an interaction between the effect of module and language preference (P < 0.01) indicating that although scores increased for both of the topic areas for the English-speaking workers, only the score for the animal health topic increased for the Spanish-speaking workers. Regardless of nationality, level of formal education, topic, or preferred language, digital media are effective at improving knowledge transfer to animal care professionals