The critical density for star formation in HII galaxies

The star formation rate (SFR) in galaxies is believed to obey a power law relation with local gas density, first proposed by Schmidt (1959). Kennicutt (1989) has shown that there is a threshold density above which star formation occurs, and for densities at or near the threshold density, the DFR is highly non-linear, leading to bursts of star formation. Skillman (1987) empirically determined this threshold for dwarf galaxies to be approximately 1 x 10(exp 21) cm(exp -2), at a linear resolution of 500pc. During the course of our survey for HI companion clouds to HII galaxies, we obtained high resolution HI observations of five nearby HII galaxies. HII galaxies are low surface brightness, rich in HI, and contain one or a few high surface brightness knots whose optical spectra resemble those of HII regions. These knots are currently experiencing a burst of star formation. After Kennicutt (1989) we determine the critical density for star formation in the galaxies, and compare the predictions with radio and optical data

Energy Dependence of Scattering Ground State Polar Molecules

We explore the total cross section of ground state polar molecules in an electric field at various energies, focusing on RbCs and RbK. An external electric field polarizes the molecules and induces strong dipolar interactions leading to non-zero partial waves contributing to the scattering even as the collision energy goes to zero. This results in the need to compute scattering problems with many different values of total M to converge the total cross section. An accurate and efficient approximate total cross section is introduced and used to study the low field temperature dependence. To understand the scattering of the polar molecules we compare a semi-classical cross section with quantum unitarity limit. This comparison leads to the ability to characterize the scattering based on the value of the electric field and the collision energy.Comment: Accepted PRA, 10 pages, 5 figure

Loyalty Program in the Alcohol Beverage Industry: A Preliminary Look

In the United States the alcoholic beverage industry has created one of the largest markets in the world. Alcohol is a taxed and well-regulated product most profitable for large chain retailers who continuously dominate the industry. This research paper reports the story of loyalty programs throughout the beverage industries. Additionally, by analyzing a database of 107 top alcohol beverage retailers, this research paper provides a profile of the market trends for alcohol beverage retailers in the United States. Secondly, this research aims to shed light on how loyalty programs form a part of the current market trends in the alcohol beverage industry

A Relationship of Wine Ratings and Wholesale Pricing, Vintage, Variety, and Region

Wine reviews, such as those from Wine Spectator and other consumer publications, help drive wine sales. The researchers in this study utilized standardized wholesale “line pricing” from a major wholesale distributor in the Southwest to compare pricing to the ratings published by Wine Spectator and to determine whether there were any correlations among other key attributes of the wine. The study produced interesting results, including that the wholesale price and vintage of a wine are significant in the prediction of the wine’s rating

An Estimation of Benefits Associated with the Wyoming State Snowmobile Trails Program

Resource /Energy Economics and Policy,

Long range scattering resonances in strong-field seeking states of polar molecules

We present first steps toward understanding the ultracold scattering properties of polar molecules in strong electric field-seeking states. We have found that the elastic cross section displays a quasi-regular set of potential resonances as a function of the electric field, which potentially offers intimate details about the inter-molecular interaction. We illustrate these resonances in a ``toy'' model composed of pure dipoles, and in more physically realistic systems. To analyze these resonances, we use a simple WKB approximation to the eigenphase, which proves both reasonably accurate and meaningful. A general treatment of the Stark effect and dipolar interactions is also presented

Sher 25: pulsating but apparently alone

The blue supergiant Sher25 is surrounded by an asymmetric, hourglass-shaped circumstellar nebula, which shows similarities to the triple-ring structure seen around SN1987A. From optical spectroscopy over six consecutive nights, we detect periodic radial velocity variations in the stellar spectrum of Sher25 with a peak-to-peak amplitude of ~12 km/s on a timescale of about 6 days, confirming the tentative detec-tion of similar variations by Hendry et al. From consideration of the amplitude and timescale of the signal, coupled with observed line profile variations, we propose that the physical origin of these variations is related to pulsations in the stellar atmosphere, rejecting the previous hypothesis of a massive, short-period binary companion. The radial velocities of two other blue supergiants with similar bipolar nebulae, SBW1 and HD 168625, were also monitored over the course of six nights, but these did not display any significant radial velocity variations.Comment: 9 pages, 7 figures. Accepted for publication in MNRA

Performance Implications of Strategic Performance Measurement in Financial Services Firms

This study examines the relation between measurement system satisfaction, economic performance, and two general approaches to strategic performance measurement: greater measurement diversity and improved alignment with firm strategy and value drivers. We find consistent evidence that firms making more extensive use of a broad set of financial and (particularly) non-financial measures than firms with similar strategies or value drivers have higher measurement system satisfaction and stock market returns. However, we find little support for the alignment hypothesis that more or less extensive measurement than predicted by the firm\u27s strategy or value drivers adversely affect performance. Instead, our results indicate that greater measurement emphasis and diversity than predicted by our benchmark model is associated with higher satisfaction and stock market performance. Our results also suggest that greater measurement diversity relative to firms with similar value drivers has a stronger relationship with stock market performance than greater measurement on an absolute scale. Finally, the balanced scorecard process, economic value measurement, and causal business modeling are associated with higher measurement system satisfaction, but exhibit almost no association with economic performance

The Effect of an Acidified-Gypsum Mixture on Broiler Litter Urease-Producing Bacteria and Nitrogen Mineralization

Broiler chicken (Gallus gallus domesticus) production is one of the largest agricultural sectors in the state of Georgia. Broiler litter produced by broiler facilities is rich in organic nitrogen (N), specifically urea, which can be mineralized by poultry litter urease-producing bacteria (PLUP) forming ammoniacal-N (NH3/NH4+). A large portion of NH3/NH4+ can be lost as ammonia (NH3) gas, which negatively impacts bird health and profitability. The release of NH3 from litter is strongly influenced by the pH of the litter. Flue-gas desulfurization gypsum (FGDG) has been suggested as a potential amendment to reduce NH3 volatilization from broiler litter due to the pH buffering capacity of calcium carbonate (CaCO3) precipitation. However, its effect on litter pH is not as pronounced as acidifying agents, such as aluminum sulfate (alum). The main objective of the present study was to develop an acidified-FGDG amendment that has a more pronounced effect on litter pH and NH3 volatilization than FGDG alone. We conducted a 33-d incubation in which litter pH, NH3 volatilization, PLUP-ureC gene abundance, and CaCO3 precipitation were measured. Treatments in the study included: broiler litter (control) (BL), broiler litter + 20% FGDG (BL+FGDG), broiler litter + FGDG-alum mixture (BL+FGDG+A6), broiler litter + 6% alum (BL+A6), and broiler litter + 10% alum (BL+A10). Our results indicated that ammending broiler litter with the FGDG+alum decreased litter pH (0.68 pH units) and PLUP-ureC gene abundance (\u3e 1 log) compared to FGDG alone and the control (p \u3c 0.05). This led to a 25% decrease in cumulative NH3 loss after 33 d. The addition of FGDG alone did not have an effect on litter pH (p = 0.36) or cumulative NH3 loss (p = 0.29) due to a lack of significant CaCO3 precipitation. Alum 6% and 10% were the most effective amendment for reducing cumulative NH3

Designing and Operating Safe and Secure Transit Systems: Assessing Current Practices in the United States and Abroad, MTI Report 04-05

Public transit systems around the world have for decades served as a principal venue for terrorist acts. Today, transit security is widely viewed as an important public policy issue and is a high priority at most large transit systems and at smaller systems operating in large metropolitan areas. Research on transit security in the United States has mushroomed since 9/11; this study is part of that new wave of research. This study contributes to our understanding of transit security by (1) reviewing and synthesizing nearly all previously published research on transit terrorism; (2) conducting detailed case studies of transit systems in London, Madrid, New York, Paris, Tokyo, and Washington, D.C.; (3) interviewing federal officials here in the United States responsible for overseeing transit security and transit industry representatives both here and abroad to learn about efforts to coordinate and finance transit security planning; and (4) surveying 113 of the largest transit operators in the United States. Our major findings include: (1) the threat of transit terrorism is probably not universal—most major attacks in the developed world have been on the largest systems in the largest cities; (2) this asymmetry of risk does not square with fiscal politics that seek to spread security funding among many jurisdictions; (3) transit managers are struggling to balance the costs and (uncertain) benefits of increased security against the costs and (certain) benefits of attracting passengers; (4) coordination and cooperation between security and transit agencies is improving, but far from complete; (5) enlisting passengers in surveillance has benefits, but fearful passengers may stop using public transit; (6) the role of crime prevention through environmental design in security planning is waxing; and (7) given the uncertain effectiveness of antitransit terrorism efforts, the most tangible benefits of increased attention to and spending on transit security may be a reduction in transit-related person and property crimes