Sturgeon Chub Distributional Patterns and Habitat Use and Benthic Fish Assemblage Structure in Missouri River Tributaries of South Dakota

Native species of the Missouri River drainage inhabiting benthic habitats dominate state and federal lists of species at risk. Sicklefin Chub Macrhybopsis meeki and Sturgeon Chub Macrhybopsis gelida are two native Missouri River benthic minnows that are currently under review for federal listing under the Endangered Species Act (ESA) due to extensive population declines and local extirpations within their native range. Substantial alterations to the Missouri River threaten Macrhybopsis spp. and other benthic fishes; however, large, less impacted tributaries in South Dakota may act as refugia for native species. The extent of Sicklefin Chub and Sturgeon Chub populations is largely unknown in the state and recent assessments documenting Missouri River benthic fish assemblages are lacking. The goal of this project was to update the distribution and abundance of benthic fishes of the Missouri River and its major tributaries with an emphasis on Sicklefin Chub and Sturgeon Chub in South Dakota. Our objectives were to: 1) evaluate abiotic and biotic influences on distributional patterns of Sicklefin Chub and Sturgeon Chub and characterize their habitat use, and 2) describe and compare patterns of benthic fish assemblage structure within rivers and for the region. Information presented herein pertains to the tributaries, due to zero catch of Macrhybopsis spp. in the mainstem Missouri River. Sturgeon Chub were captured in the Cheyenne, White, and Little White rivers but were absent from the Little Missouri and Grand rivers. Relative abundances of both age-0 and age-1+ Sturgeon Chub were highest in the White River. Distributions of Sturgeon Chubs were limited to lower areas of all rivers where stream width, turbidity, discharge, and observed habitat complexity were highest and Flathead Chub Platygobio gracilis and Hybognathus spp. (Plains Minnow H. placitus and Western Silvery Minnow H. argyritis) were more abundant. Sturgeon Chub primarily used main or secondary flowing channels and were predominantly found in or near the thalweg. Velocity, depth, and percent gravel predicted Sturgeon Chub presence on smaller scales. Predominantly native fish assemblages were observed in all rivers. Total species richness was lowest in the White River, where extreme environmental conditions likely limit species diversity and nonnative species establishment. Longitudinal patterns of assemblage structure were observed in the White, Cheyenne, and Little White rivers due to natural and anthropogenic changes in habitat conditions. Species additions occurred as rivers gradually increased in size and habitat complexity, but native species were replaced in response to abrupt habitat changes, such as those created by impoundments. High abundances of native, benthic fishes in Missouri River tributaries of South Dakota that are experiencing overall population declines highlights the importance of large, relatively unaltered tributaries to the conservation of freshwater biodiversity in North America. Advisor: Mark A. Peg

Intergenerational Networks, Unemployment, and Persistent Inequality in

Abstract This paper examines the role of parents as network members in helping children secure employment in South Africa, where unemployment is high enough that employment is a key indicator of economic status. This possibility has long been suggested by the intergenerational correlations literature, but has received limited empirical scrutiny due to difficulties inherent in separating networks from correlated fixed effects such as preferences, genetic and wealth endowments, and neighborhood sorting. Unlike previous empirical network papers, this paper examines the covariance of childrens' outcomes with individual network nodes' (i.e. parents) usefulness in job search, as proxied by employment in the parents' industries. A new panel data set in South Africa allows the removal of individual-specific heterogeneity correlated with these parents' industries; while the institutional structure of South Africa allows the creation of control groups who should be impacted by wealth effects correlated with growth in the parents' industry but not networks. This paper finds that fathers serve as useful network connections to their sons when able, but that mothers do not seem to be useful network connections for any of their children. The possibilities of specific human capital, correlated networks, and multinomial choice are examined and do not interfere with the father-son network effect. These results suggest that a decline in economic mobility in 1 South Africa may be attributable to the expansion of small-scale networks, and that caution must be taken in drawing welfare implications from network studies which do not observe the relevant scale of networks

Optical properties of multicomponent cadmium-silver nanocluster composites formed in silica by sequential ion implantation

Formation and optical properties of nanometer dimension metal colloid composites formed by sequential implantation of Cd then Ag and by single element implantations of Cd and Ag in silica were characterized by TEM and optical spectroscopy. A nominal dose of 6x10{sup 16} ions/cm{sup 2} as determined by current integration was used for both ion species. Doses used for the sequential implantations were a 1 to 1 ratio of Cd to Ag. Sequential implantations of Cd and Ag led to formation of both multi-component metal nanoclusters and elemental nanoclusters. Electron diffraction indicated that the polycrystalline particles of Ag{sub 5}Cd{sub 8} and elemental Ag were formed. The optical response was consistent with results expected from effective medium theory

Linear and Nonlinear Optical Properties of Metal Nanocluster-Silica Composites Formed by Sequential Implantation of Ag and Cu

Nanometer dimension metal colloids were formed in silica by sequential implantation of Ag and Cu ions. The Ag and Cu were implanted with relative ratios of Ag to Cu of 9:3, 6:6, and 3:9. The total nominal dose was 12 {times} 10{sup 16} ions/cm{sup 2}. TEM techniques were used to examine colloid size and size distributions. The linear optical response was measured from 200 to 900 nm. The nonlinear optical properties were measured using the z-scan technique at a wavelength of 570 nm. The linear and nonlinear optical properties were found to be dependent upon the relative ratio of sequentially implanted Ag to Cu. The results are consistent with effective medium theory

Association of Over-The-Counter Pharmaceutical Sales with Influenza-Like-Illnesses to Patient Volume in an Urgent Care Setting

We studied the association between OTC pharmaceutical sales and volume of patients with influenza-like-illnesses (ILI) at an urgent care center over one year. OTC pharmaceutical sales explain 36% of the variance in the patient volume, and each standard deviation increase is associated with 4.7 more patient visits to the urgent care center (p<0.0001). Cross-correlation function analysis demonstrated that OTC pharmaceutical sales are significantly associated with patient volume during non-flu season (p<0.0001), but only the sales of cough and cold (p<0.0001) and thermometer (p<0.0001) categories were significant during flu season with a lag of two and one days, respectively. Our study is the first study to demonstrate and measure the relationship between OTC pharmaceutical sales and urgent care center patient volume, and presents strong evidence that OTC sales predict urgent care center patient volume year round. © 2013 Liu et al

Complications and Healthcare Cost of Total Hip Arthroplasty in Patients with Depressive Disorder

PURPOSE: The purpose of this study was to determine whether the rates of (1) in-hospital lengths of stay (LOS), (2) readmissions, (3) medical complications, and (4) costs of care are higher for patients with depressive disorder (DD) undergoing primary total hip arthroplasty (THA) for treatment of femoral neck fractures (FNFs). MATERIALS AND METHODS: A retrospective query of a national administrative claims database for patients undergoing primary THA from 2006 to 2014 was conducted. Patients with DD undergoing THA for treatment of FNF were 1:5 ratio propensity score matched to a cohort (DD=6,758, controls=33,708). Primary endpoints included LOS, 90-day medical complications, 90-day readmissions, and healthcare reimbursements. A RESULTS: Longer LOS were observed for patients with DD compared to those without DD (5.6 days vs. 5.4 days, CONCLUSION: Our findings showed longer LOS, higher odds of 90-day medical complications, and higher healthcare expenditures within the 90-day episode of care following a primary THA for treatment of FNF for patients with DD compared to the matched cohort. Thus, accordingly, patients with DD should receive counseling prior to undergoing surgery

Perturbation Theory with a Variational Basis: the Generalized Gaussian Effective Potential

The perturbation theory with a variational basis is constructed and analyzed.The generalized Gaussian effective potential is introduced and evaluated up to the second order for selfinteracting scalar fields in one and two spatial dimensions. The problem of the renormalization of the mass is discussed in details. Thermal corrections are incorporated. The comparison between the finite temperature generalized Gaussian effective potential and the finite temperature effective potential is critically analyzed. The phenomenon of the restoration at high temperature of the symmetry broken at zero temperature is discussed.Comment: RevTex, 49 pages, 16 eps figure

Fabrication and modification of metal nanocluster composites using ion and laser beams

Metal nanocluster composites have attractive properties for applications in nonlinear optics. However, traditional fabrication techniques -- using melt-glass substrates -- are severely constrained by equilibrium thermodynamics and kinetics. This paper describes the fabrication of metal nanoclusters in both crystalline and glassy hosts by ion implantation and pulsed laser deposition. The size and size distribution of the metal nanoclusters can be modified by controlling substrate temperature during implantation, by subsequent thermal annealing, or by laser irradiation. The authors have characterized the optical response of the composites by absorption and third-order nonlinear-optical spectroscopies; electron and scanning-probe microscopies have been used to benchmark the physical characteristics of the composites. The outlook for controlling the structure and nonlinear optical response properties of these nanophase materials appears increasingly promising