Nicholls State University

About: Nicholls State University is a education organization based out in Thibodaux, Louisiana, United States. It is known for research contribution in the topics: Population & The Internet. The organization has 456 authors who have published 795 publications receiving 20031 citations.

The role of water ventilation and sediment ingestion in the uptake of benzo[A]pyrene in gizzard shad (dorosoma cepedianum)

Abstract: The objective of this study was to determine whether sediment ingestion or water ventilation was the primary route of uptake for benzo[a]pyrene (BaP) in the gizzard shad (Dorosoma cepedianum), a detritivorous fish. Two experiments were conducted in which fish were exposed to sediments spiked with 1 {micro}g/g BaP. In the first experiment, fish were prevented from feeding by esophagus ligation. In the second experiment, 20 nonligated fish and 30 ligated fish were added to the aquarium. The nonligated fish roiled the water as they fed. Fish were collected 4, 8, 15, and 22 d after the experiments began. Gizzard shad metabolize BaP; therefore, the concentrations of BaP equivalents (parent BaP plus metabolite) were determined. Concentrations of BaP equivalents were significantly greater in the ligated fish in experiment 2 relative to those in experiment 1. In contrast, the concentration of BaP equivalents in the ligated fish in experiment 2 was not significantly different than that in the nonligated fish. The results suggest that ventilation of turbid water may be a significant source of BaP for gizzard shad. Sediment ingestion, however, does not appear to significantly influence the total body concentration of BaP equivalents in gizzard shad.

Detailed Mechanism for Photoinduced Cytosine Dimerization: A Semiclassical Dynamics Simulation

Abstract: Semiclassical dynamics simulation is used to study dimerization of two stacked cytosine molecules following excitation by ultrashort laser pulses (25 fs fwhm, Gaussian, 4.1 eV photon energy). The i...

Short-Term Demographic Responses of a Coastal Waterbird Community After Two Major Hurricanes

Abstract: . Response of breeding waterbird communities to the effects of hurricanes remains poorly understood. The impact of two 2008 hurricanes on the breeding waterbird community was investigated at the Isles Dernieres Barrier Island Refuge in southern Louisiana using pre- and post-hurricane survey data. After the 2008 hurricanes, the breeding community was reduced from 44,042 breeding pairs in 2008 to 27,977 pairs in 2009 and to 23,544 pairs in 2010. Populations of the five most abundant species, Brown Pelican (Pelecanus occidentalis), Laughing Gull (Leucophaeus atricilla), Royal Tern (Thallasseus maximus), Sandwich Tern (Thallasseus sandvincensis), and Black Skimmer (Rynchops niger), decreased from 2008 to 2010. In contrast, populations of Roseate Spoonbill (Platalea ajaja), Sooty Tern (Onychoprion fuscatus), and Gull-billed Tern (Gelochelidon nilotica) increased from 2008 to 2009 but declined in 2010. The dramatic decline of total breeding pairs in the year following hurricanes demonstrates the vulnera...