Frequency-dependent polarizabilities of alkali atoms from ultraviolet through infrared spectral regions

We present results of first-principles calculations of the frequency-dependent polarizabilities of all alkali atoms for light in the wavelength range 300-1600 nm, with particular attention to wavelengths of common infrared lasers. We parameterize our results so that they can be extended accurately to arbitrary wavelengths above 800 nm. This work is motivated by recent experiments involving simultaneous optical trapping of two different alkali species. Our data can be used to predict the oscillation frequencies of optically-trapped atoms, and particularly the ratios of frequencies of different species held in the same trap. We identify wavelengths at which two different alkali atoms have the same oscillation frequency.Comment: 6 pages, 2 figure

Elephant Training and Ride Operations, Part I: Animal Health, Cost/Benefit and Philosophy

Results from a survey, conducted by the authors as employees of the Burnet Park Zoo, show that very few captive elephants in zoos (18 in the USA) are trained for ride operations. Trained elephants are easily accessable for treatment, are less bored , and overall are healthier than non-trained elephants, which may be manifested in a longer life span. The benefits derived from a well planned elephant training and ride operation clearly outweigh the costs incurred

State-insensitive bichromatic optical trapping

We propose a scheme for state-insensitive trapping of neutral atoms by using light with two independent wavelengths. In particular, we describe the use of trapping and control lasers to minimize the variance of the potential experienced by a trapped Rb atom in ground and excited states. We present calculated values of wavelength pairs for which the 5s and 5p_{3/2} levels have the same ac Stark shifts in the presence of two laser fields.Comment: 5 pages, 4 figure

Valuation of Transferable Delivery Rights for Marketing Cooperatives

Delivery rights to a cooperative\u27s marketing pool can take on a value independent of the members\u27 equity share under certain conditions. Based on anecdotal information, transferable delivery rights become valuable when the pool is fixed in size (closed), members are protected from exploitation of quasi economic rents, and have an assured home for their production. The greater the potential buyers\u27 aversion to risk, the higher the value of the delivery right. The right has additional value if the cooperative generates a premium per unit return due to product differentiation and market power. Cooperatives competing with investor-owned firms in less than purely competitive markets must be able to pay equal net returns to members if they are to survive

Accurate determination of electric-dipole matrix elements in K and Rb from Stark shift measurements

Stark shifts of potassium and rubidium D1 lines have been measured with high precision by Miller et al [1]. In this work, we combine these measurements with our all-order calculations to determine the values of the electric-dipole matrix elements for the 4p_j-3d_j' transitions in K and for the 5p_j-4d_j' transitions in Rb to high precision. The 4p_1/2-3d_3/2 and 5p_1/2-4d_3/2 transitions contribute on the order of 90% to the respective polarizabilities of the np_1/2 states in K and Rb, and the remaining 10% can be accurately calculated using the relativistic all-order method. Therefore, the combination of the experimental data and theoretical calculations allows us to determine the np-(n-1)d matrix elements and their uncertainties. We compare these values with our all-order calculations of the np-(n-1)d matrix elements in K and Rb for a benchmark test of the accuracy of the all-order method for transitions involving nd states. Such matrix elements are of special interest for many applications, such as determination of magic wavelengths in alkali-metal atoms for state-insensitive cooling and trapping and determination of blackbody radiation shifts in optical frequency standards with ions.Comment: 5 page

Alfalfa Yields from Mixtures of Dormant and Non-dormant Varieties

During the establishment year, alfalfa seedings typically yield only 40-60% of fully established stands. All alfalfa varieties grown in Iowa are classified as dormant or moderately dormant, a characteristic that is important for winter survival. However, as plants become dormant in late summer, their yield declines. Alfalfa varieties from the southwestern United States are non-dormant and continue to grow until the autumn freeze, but tend to die over winter. The objective of this experiment was to determine if including a proportion of non-dormant seed at planting could improve establishment year yield without affecting successive year yields or forage quality. The rationale for this experiment is that more plants are present in the first year of a stand than in successive years when individual plants grow larger as their crowns expand. Because of normal plant loss, we reasoned that death of non-dormant plants after the first winter might not adversely affect the yields of the remaining stand

Pastoral Leaders’ Perception of Obesity and Their Role Within Faith-Based Organizations

The purpose of this study was to explore the perspectives of pastoral leaders regarding obesity and health within faith-based organizations (FBOs). In this study, the authors focused on gaining additional insight regarding how pastoral leaders conceptualize and make sense of their roles in terms of health promotion within FBOs. Utilizing a qualitative research methodological approach, specifically Qualitative Description, authors administered a qualitative survey to 12 participants which yielded three emerging themes: (1) perceived scope, (2) understanding and use of resources, and (3) defining obesity through pastoral leaders’ perspectives. In the study, investigators discuss clinical implications and provide recommendations