Dietary Comparisons of Red-Winged Blackbirds, Brown-Headed Cowbirds, and European Starlings in North-Central Ohio

Author Institution: Department of Biological Sciences, Bowling Green State University ; Environmental Studies Center, Bowling Green State UniversityStomach contents from 99 red-winged blackbirds, 97 brown-headed cowbirds, and 69 European starlings collected along the southern edge of Lake Erie in north-central Ohio were compared using aggregate volume measurments. Agricultural products comprised 73.9%, 54.8%, and 28.1% of the redwing, cowbird, and starling diets, respectively. Corn accounted for 70.8%, 26.2%, and 3.3% of the diets, respectively. Animal material represented 7.6%, 3.4%, and 30.3% of the diets, respectively. Injurious insects comprised 13-5% of the starling diet but were relatively unimportant in the diets of redwings and cowbirds. Beneficial arthropods were relatively unimportant in all the diets

An Investigation of the Binding Properties of Limestone Dust

A proper quantity of dust particles of various sizes has long been recognized as important in the construction of stone bases and pavements. Screenings for water bound macadam bases are required to contain not less than a specified amount of dust sizes, and dense-graded limestone bases have controlling limits for the dust fraction. It is generally assumed that these particles serve a dual purpose: (1) in filling void spaces created by larger particles, thus enhancing the gross structure of the aggregate, and (2) in acting as a binder material in the presence of water. Furthermore, it has been demonstrated that the addition of small amounts of certain chemicals may improve the strength characteristics of lime stone dusts. Former studies have been concerned primarily with the overall strength properties of aggregate mixtures containing dust, rather than with the properties of the dust itself. However, in cases where binding properties are of primary concern, a more fundamental approach would be to investigate the dust and fine aggregate fractions before studying the mixture as a whole. The purpose of this project was to study the binding properties of several different limestone dusts. The stones selected showed considerable differences in composition, and undoubtedly the scope of these differences encompassed the majority of limestones in Kentucky. In addition, an attempt was made to detect variations (if any) in the response of these stones to the effects induced by admixtures of calcium chloride - directly or indirectly

Computers and Learning

The important questions for instructors to address concern what skills the student is to learn and how the student is to be motivated to acquire those skills. Questions about simulations, graphics tools, and the like are unimportant until the first two questions have been answered adequately. We discuss the role of explanation by students and describe a mechanism for motivating students to learn

Time-Series Analyses of Supergranule Characteristics Compared Between SDO/HMI, SOHO/MDI and Simulated Datasets

Supergranulation is a well-observed solar phenomenon despite its underlying mechanisms remaining a mystery. Originally considered to arise due to convective motions, alternative mechanisms have been suggested such as the cumulative downdrafts of granules as well as displaying wave-like properties. Supergranule characteristics are well documented, however. Supergranule cells are approximately 35 Mm across, have lifetimes on the order of a day and have divergent horizontal velocities of around 300 mis, a factor of 10 higher than their central radial components. While they have been observed using Doppler methods for more than half a century, their existence is also observed in other datasets such as magneto grams and Ca II K images. These datasets clearly show the influence of supergranulation on solar magnetism and how the local field is organized by the flows of supergranule cells. The Heliospheric and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO) continues to produce Doppler images enabling the continuation of supergranulation studies made with SOHO/MDI, but with superior temporal and spatial resolution. The size-distribution of divergent cellular flows observed on the photosphere now reaches down to granular scales, allowing contemporaneous comparisons between the two flow components. SOHO/MDI Doppler observations made during the minima of cycles 22/23 and 23/24 exhibit fluctuations of supergranule characteristics (global averages of the supergranule size, size-range and horizontal velocity) with periods of 3-5 days. Similar fluctuations have been observed in SDO/HMI Dopplergrams and the high correlation between co-temporal HMI & MOl suggest a solar origin. Their nature has been probed by invoking data simulations that produce realistic Dopplergrams based on MOl data

Women On Boards Of Directors: Effects On Firm Social Performance In The Basic Materials And Financial Services Sectors

This study examined relationships between the number of female board members, board tenure, and board size on the number of 10K investigations that were instigated against  firms in the basic materials and financial services sectors of the economy.  After controlling for the effects of firm size, we found evidence of an interaction effect between the number of female directors and average board tenure for firms in the financial services sector, such that a higher number of women on boards coupled with longer average board tenure results in higher firm social performance (i.e., the fewer the number of 10K investigations brought against the firm).  No link was found between female directors and average board tenure for the basic materials firms.  Further, no interactive patterns were observed between female directors and board size in either sector.  Our findings suggest that future board research may benefit from a “contingency approach,” as this study has provided some evidence that the relationships between board characteristics and firm performance may not be generalizable from one sector to another.  Future research should carefully consider how the sector or industry may affect the impact of board characteristics on firm performance

Pulsed Triple Frequency Modulation for Frequency Stabilization and Control of Two Lasers to an Optical Cavity

We present a method to stabilize two lasers to an optical cavity using pulsed triple frequency modulation. The setup allows simultaneous Pound–Drever–Hall stabilization, as well as independent frequency control, while removing interference terms that limit the frequency scan range and allowing for smaller modulation depths. A review of single, dual, and triple frequency modulation is also presented in addition to a discussion of how to effectively turn pulsed triple frequency modulation into independent dual frequency modulation for each laser. This method would increase the scan range to half the free spectral range

Absolute Frequency Measurement of the lLevel of Neutral Using Two-Photon Spectroscopy

We report absolute frequency measurements on the level of neutral using sub-Doppler two-photon spectroscopy. The absolute center-of-gravity energy for the level is determined to be , a factor of 170 times improvement over the previous measurement from 1964 of . This measurement also corrects a discrepancy with the previously measured value. The hyperfine coefficients were found to be and , which are consistent with previous results