Flow, Just Flow: Variations on a Theme

Flow, Just Flow: Variations on a Theme Joel and Lila Harnett Museum of Art University of Richmond Museums, VA January 29 to June 28, 2013 Psychologist Mihaly Csikszentmihalyi first used the term “flow” in 1975 to describe “being completely involved in an activity for its own sake. The ego falls away. Time flies. Every action, movement, and thought follows inevitably from the previous one, like playing jazz.” Accordingly, this experience of single-minded immersion in an activity that is continuously challenging and rewarding is the secret to a vigorous and satisfying life. Also referred to as “being in the zone,” this state of flow is the launching point for this exhibition and online catalogue, which present a variety of media involving kinetic forms, non-static content generation, visitor interaction, and collective states of being. Twenty-four works of art by twenty-one artists of national and international origin explore a range of definitions and applications of the word “flow,” from dynamism and movement to ideas and communication. The exhibition is organized by University of Richmond Museums and curated by N. Elizabeth Schlatter, Deputy Director and Curator of Exhibitions, University Museums. The exhibition and programs are made possible in part by the University’s Cultural Affairs Committee, and funds from the Louis S. Booth Arts Fund. Additional support has been provided by grants from the Swiss Arts Council Pro Helvetia and the Austrian Cultural Forum, Washington, DC.https://scholarship.richmond.edu/exhibition-catalogs/1000/thumbnail.jp

Diurnal Fish Density in Relation to Seagrass and Drift Algae Cover in Tampa Bay, Florida

To assess the relationship between fish density and seagrass and drift algae cover on a small geographic scale, we collected quantitative data on fish and vegetation communities during daylight hours near the mouth of the Little Manatee River, Tampa Bay, Florida. In 1991, fish were collected with two types of sampling gear, a 120-m long-haul seine and 1-m2 roving dropnets. Seagrass and drift algae cover in each sampled area was categorized as none, sparse, moderate, or dense. Despite evident gear bias, sampling with both types of gear produced similar overall fish densities. Anchoa mitchilli, Lagodon rhomboides, and Syngnathus scovelli were the most abundant or frequently collected species, regardless of gear type. Densities of 12 of the 20 most abundant species were significantly related to either seagrass or drift algae cover or both. When fish density-vegetation cover relationships were significant, the greatest fish densities always occurred in either dense or moderate covers of seagrass or drift algae. Densities of L. rhomboides and Orthopristis chrysoptera were positively related to the level of seagrass and drift algae cover in samples collected with both types of gear, but significant relationships between the densities of other species and the level of vegetation cover generally varied by vegetation or gear type (or both). Density of Eucinostomus gula peaked in moderate seagrass and declined at higher and lower levels of cover. Total fish density was similar at sites dominated by either drift algae or seagrass but was significantly reduced at sites with little cover from either vegetation type. We conclude that both seagrass and drift algae are essential habitats for juvenile and small adult fish in Tampa Bay and that fish density on a small geographic scale is strongly related to vegetation cover. Drift algae may form an important alternate habitat for fish during winter months, when levels of seagrass cover are lowest and those of drift algae are highest

A simulation study of sample size for multilevel logistic regression models

<p>Abstract</p> <p>Background</p> <p>Many studies conducted in health and social sciences collect individual level data as outcome measures. Usually, such data have a hierarchical structure, with patients clustered within physicians, and physicians clustered within practices. Large survey data, including national surveys, have a hierarchical or clustered structure; respondents are naturally clustered in geographical units (e.g., health regions) and may be grouped into smaller units. Outcomes of interest in many fields not only reflect continuous measures, but also binary outcomes such as depression, presence or absence of a disease, and self-reported general health. In the framework of multilevel studies an important problem is calculating an adequate sample size that generates unbiased and accurate estimates.</p> <p>Methods</p> <p>In this paper simulation studies are used to assess the effect of varying sample size at both the individual and group level on the accuracy of the estimates of the parameters and variance components of multilevel logistic regression models. In addition, the influence of prevalence of the outcome and the intra-class correlation coefficient (ICC) is examined.</p> <p>Results</p> <p>The results show that the estimates of the fixed effect parameters are unbiased for 100 groups with group size of 50 or higher. The estimates of the variance covariance components are slightly biased even with 100 groups and group size of 50. The biases for both fixed and random effects are severe for group size of 5. The standard errors for fixed effect parameters are unbiased while for variance covariance components are underestimated. Results suggest that low prevalent events require larger sample sizes with at least a minimum of 100 groups and 50 individuals per group.</p> <p>Conclusion</p> <p>We recommend using a minimum group size of 50 with at least 50 groups to produce valid estimates for multi-level logistic regression models. Group size should be adjusted under conditions where the prevalence of events is low such that the expected number of events in each group should be greater than one.</p

SweetSpot: Near-Infrared Observations of Thirteen Type Ia Supernovae from a New NOAO Survey Probing the Nearby Smooth Hubble Flow

We present 13 Type Ia supernovae (SNe Ia) observed in the restframe near-infrared (NIR) from 0.02 < z < 0.09 with the WIYN High-resolution Infrared Camera (WHIRC) on the WIYN 3.5-m telescope. With only 1-3 points per light curve and a prior on the time of maximum from the spectrum used to type the object we measure an H-band dispersion of spectroscopically normal SNe Ia of 0.164 mag. These observations continue to demonstrate the improved standard brightness of SNe Ia in H-band even with limited data. Our sample includes two SNe Ia at z ~ 0.09, which represent the most distant restframe NIR H-band observations published to date. This modest sample of 13 NIR SNe Ia represent the pilot sample for "SweetSpot" - a three-year NOAO Survey program that will observe 144 SNe Ia in the smooth Hubble flow. By the end of the survey we will have measured the relative distance to a redshift of z ~ 0.05 to 1%. Nearby Type Ia supernova (SN Ia) observations such as these will test the standard nature of SNe Ia in the restframe NIR, allow insight into the nature of dust, and provide a critical anchor for future cosmological SN Ia surveys at higher redshift.Comment: 36 pages, 8 figures, Submitted to Ap

Bulk Density of Some Oklahoma Soils and Their Mineralogical Composition

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The Threespine Bass, Synagrops trispinosus (Perciformes; Acropomatidae), an Addition to the Fish Fauna of the Gulf of Mexico

We present the first documented record of Synagrops trispinosus in the Gulf of Mexico. This record represents a moderate extension to the known southern Caribbean distribution; it is nevertheless a new addition to the ichthyofauna of U.S. coastal waters