Some calculations on the ground and lowest-triplet state of the helium isoelectronic sequence with the nucleus in motion

The method described in the preceding paper for the solution of two-electron atoms, which was used to calculate the 1 1S and 2 3S states of helium and heliumlike atoms within the fixed-nucleus approximation, has been applied to the case where all three particles are in relative motion. The solutions in the present case automatically include the effects of the mass polarization term and are compared with the results obtained for the term by using first-order perturbation theory with the fixed-nucleus wave functions. The input data for a particular atom consist of the atomic number, as before, but now the corresponding mass of the nucleus must be given also. Nonrelativistic energies with the nuclear mass included in the calculation have been obtained for the 1 1S and 2 3S states for Z ranging from 1 to 10. The energy with the nucleus in motion can be expressed only to eight significant figures (SF's) given the accuracy with which the relevant physical constants are known at present. All the results given here are computed as if these constants were known to ten SF's so that errors not incurred due to rounding. Convergence of the energies to ten SF's for both the singlet and triplet state was reached with a matrix of size 444 for Z values from 2 to 10. Convergence for the H- ion was a little slower

Understanding Shoplifting of Fast-Moving Consumer Goods: An Application of the CRAVED Model

This study examines the variation in theft of shoplifted fast-moving consumer goods. Typically, shoplifting is estimated using shrinkage—a composite of several causes of lost retail merchandise. This study, however, benefits from access to a retailer’s database, in which extraordinary steps are taken to identify and record losses due to shoplifting only. This study is unique because of the more valid measure of shoplifting. A 1-year cross-sectional sample of 7468 products, sold in 204 U.S. chain supermarkets, was drawn from the retailer’s specialized database. Using Clarke’s (Hot products: understanding, anticipating, and reducing demand for stolen goods. Policing and Reducing Crime Unit, Paper 112, Home Office, London, 1999) CRAVED model of theft, products’ theft rates were correlated to the attributes consistent with the most vulnerable targets of theft. The results show that theft rates of products were significantly correlated to the measures for CRAVED. Regression analysis indicated that the measures for CRAVED were significant predictors of theft. Specifically, products were stolen more often when they were more Concealable, less Available, more Valuable, Enjoyable, and more Disposable. The most frequently stolen types of products were several types of cosmetics—primarily small but expensive products (e.g., eye, nail, lip products). Additionally, electronics, toys, and games had high theft rates. Implications for retailers, manufacturers, and governments are discussed. Suggestions for further research are also considered

Activity-dependent plasticity of transmitter release from nerve terminals in rat fast and slow muscles

Available under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported license.Peer reviewedPublisher PD

Kelley Carrera and Brian T. Smith in a Joint Junior Recital

This is the program for the joint junior recital of pianist Kelley Carrera and baritone Brian T. Smith. Pianist Jay B. Crowder assisted Smith\u27s performance. The recital took place on March 11, 1988, in the Mabee Fine Arts Center Recital Hall

Diffuse Interstellar Bands in z < 0.6 CaII Absorbers

The diffuse interstellar bands (DIBs) probably arise from complex organic molecules whose strength in local galaxies correlates with neutral hydrogen column density, N(HI), and dust reddening, E(B-V). Since CaII absorbers in quasar (QSO) spectra are posited to have high N(HI) and significant E(B-V), they represent promising sites for the detection of DIBs at cosmological distances. Here we present the results from the first search for DIBs in 9 CaII-selected absorbers at 0.07 < z_abs < 0.55. We detect the 5780Ang DIB in one line of sight at z_abs = 0.1556; this is only the second QSO absorber in which a DIB has been detected. Unlike the majority of local DIB sight-lines, both QSO absorbers with detected DIBs show weak 6284Ang absorption compared with the 5780Ang band. This may be indicative of different physical conditions in intermediate redshift QSO absorbers compared with local galaxies. Assuming that local relations between the 5780Ang DIB strength and N(HI) and E(B-V) apply in QSO absorbers, DIB detections and limits can be used to derive N(HI) and E(B-V). For the one absorber in this study with a detected DIB, we derive E(B-V) = 0.23mag and log[N(HI)] >= 20.9, consistent with previous conclusions that CaII systems have high HI column densities and significant reddening. For the remaining 8 CaII-selected absorbers with 5780Ang DIB non-detections, we derive E(B-V) upper limits of 0.1-0.3mag.Comment: 5 pages, 2 figures. Accepted to MNRAS Letter

Discovery of a Metal-Line Absorber Associated with a Local Dwarf Starburst Galaxy

We present optical and near-infrared images, H I 21 cm emission maps, optical spectroscopy, and Hubble Space Telescope/Space Telescope Imaging Spectrograph ultraviolet spectroscopy of the QSO/galaxy pair SBS 1122+594/IC 691. The QSO sight line lies at a position angle of 27 degrees from the minor axis of the nearby dwarf starburst galaxy IC 691 (cz_gal = 1204+-3 km/s, L_B ~ 0.09 L*, current star formation rate = 0.08-0.24 solar masses per year) and 33 kpc (6.6 arcmin) from its nucleus. We find that IC 691 has an H I mass of M_HI = (3.6+-0.1) x 10^8 solar masses and a dynamical mass of M_dyn = (3.1+-0.5) x 10^10 solar masses. The UV spectrum of SBS 1122+594 shows a metal-line (Ly-alpha + C IV) absorber near the redshift of IC 691 at cz_abs = 1110+-30 km/s. Since IC 691 is a dwarf starburst and the SBS 1122+594 sight line lies in the expected location for an outflowing wind, we propose that the best model for producing this metal-line absorber is a starburst wind from IC 691. We place consistent metallicity limits on IC 691 ([Z/Zsun] ~ -0.7) and the metal-line absorber ([Z/Zsun] < -0.3). We also find that the galaxy's escape velocity at the absorber location is v_esc = 80+-10 km/s and derive a wind velocity of v_w = 160+-50 km/s. Thus, the evidence suggests that IC 691 produces an unbound starburst wind that escapes from its gravitational potential to transport metals and energy to the surrounding intergalactic medium.Comment: 31 pages, 8 figures; AJ in press; a version with high resolution figures can be downloaded from http://casa.colorado.edu/~keeney/research/papers/IC691.pd

Molecular evolution and historical biogeography of new world birds

Deciphering the patterns of how biodiversity has evolved across time and space has remained a fundamental objective for biologists for the last 200 years. Researchers are faced with the challenge of interpreting the complexity of evolutionary patterns that have been generated over the deep history of the Earth. The advancement of DNA sequencing technology has yielded a new and powerful genetic toolkit that has allowed biologists to address novel evolutionary questions. For my dissertation research, I used molecular genetics and a statistical framework to study the evolution and historical biogeography of birds distributed in North and South America. My dissertation encompasses three separate research projects that examined the relationship between changes in the Earth\u27s climate and geology and the evolution of avian taxa. I examined evolutionary processes that operate on three different biological scales: within populations, among populations, and species\u27 assemblages. For my first research project, I used a bird species as a model to determine the processes responsible for generating genetic diversity and structure in populations (Chapter 2). I showed that genetic diversity is not just affected by processes that operate over long evolutionary periods, but additionally genetic diversity is impacted by on-going processes. In my second research project, I evaluated the relationship between population size and the rate at which populations evolve (Chapter 3). For this project, I developed a new analytical framework using population genetic theory to show that small populations evolve faster than large populations. For my final research project, I showed how the formation of a land bridge between North and South America was critical for birds to disperse between continents (Chapter 4). Overall, my dissertation provides new insight into avian evolution by identifying processes across time and space linked to the genetic patterns observable in the birds of North and South America

A Netaware Development, Support, and Maintenance Environment For DOE Numerical Libraries.

A study was performed to identify tools needed to support the maintenance of DOE scientific software and libraries destined to operate over a computational grid. The study quickly identified the need for a harness, called the Test Harness, that could evaluate the numeric results obtained from the same software over a variety of computational platforms. The test harness is installed in the application software or library procedures and monitors the results obtained from porting the application software to new platforms or enhancing the software for whatever reason (fo

Computational fluid dynamic analysis of bioprinted self-supporting perfused tissue models

Natural tissues are incorporated with vasculature, which is further integrated with a cardiovascular system responsible for driving perfusion of nutrient‐rich oxygenated blood through the vasculature to support cell metabolism within most cell‐dense tissues. Since scaffold‐free biofabricated tissues being developed into clinical implants, research models, and pharmaceutical testing platforms should similarly exhibit perfused tissue‐like structures, we generated a generalizable biofabrication method resulting in self‐supporting perfused (SSuPer) tissue constructs incorporated with perfusible microchannels and integrated with the modular FABRICA perfusion bioreactor. As proof of concept, we perfused an MLO‐A5 osteoblast‐based SSuPer tissue in the FABRICA. Although our resulting SSuPer tissue replicated vascularization and perfusion observed in situ, supported its own weight, and stained positively for mineral using Von Kossa staining, our in vitro results indicated that computational fluid dynamics (CFD) should be used to drive future construct design and flow application before further tissue biofabrication and perfusion. We built a CFD model of the SSuPer tissue integrated in the FABRICA and analyzed flow characteristics (net force, pressure distribution, shear stress, and oxygen distribution) through five SSuPer tissue microchannel patterns in two flow directions and at increasing flow rates. Important flow parameters include flow direction, fully developed flow, and tissue microchannel diameters matched and aligned with bioreactor flow channels. We observed that the SSuPer tissue platform is capable of providing direct perfusion to tissue constructs and proper culture conditions (oxygenation, with controllable shear and flow rates), indicating that our approach can be used to biofabricate tissue representing primary tissues and that we can model the system in silico