Reproductive Biology of the Frecklebelly Darter, Percina stictogaster (Teleostei: Percidae)

The reproductive biology of the Frecklebelly Darter, Percina stictogaster, was studied in the Red River, Menifee-Powell counties, Kentucky, from 2009-2012. Males and females mature at Age II. Spawning occurs from late February to early April in water temperatures of 7-16° C in areas with strong current (0.16-0.88 m/sec) and fine gravel substrates. A 52 mm SL female collected in early March had 100 mature ova. Aquarium observations confirm this species buries its eggs in a manner similar to other Percina darters. Fertilized eggs were about 2.5 mm in diameter, clear, demersal, and slightly adhesive. At 10° C eggs hatched in 18-25 days (100% survival) into larvae 7-8 mm TL. Larvae were initially benthic, but became pelagic 2- 3 days later. By about 11 mm TL, the yolk sac was absorbed, and the young returned to the bottom. In early June, young (about 2 months old) were 16-25 mm SL and had acquired diagnostic pigmentation. They occupied areas with Justicia sp. or coarse woody debris in low-velocity habitats, adjacent to riffles

Community College Faculty Perceptions of Climate for Instructional Improvement

The purpose of this study was to examine the perceptions of faculty in Washington State regarding climate for instructional improvement. The Survey of Climate for Instructional Improvement (SCII) was administered to faculty at a community college in Washington State. Through exploratory factor analysis, four factors emerged which aligned with four antecedents of change-oriented organizational citizenship behavior (OCB) proposed by López-Domínguez et al. Responses were compared using t-tests, analysis of variance (ANOVA), and multivariate analysis of variance (MANOVA) for faculty status (full-time and part-time), academic division, gender identity, race/ethnicity, and years of teaching experience. The primary finding of this study was the theoretical alignment of the four factors with the four antecedents of change-oriented OCB: Developmental Leadership, Support for Innovation, Resource Availability, and Supportive Leadership. This study also found that full-time faculty reported a lower perception of Resource Availability than part-time faculty. Additionally, faculty with 8-20 years of teaching experience reported lower perceptions of climate for instructional improvement than faculty with 0-7 and 21 or more years of experience. Finally, the mean perceptions of climate for instructional improvement were consistently higher for non-white faculty than white faculty. This study’s findings have implications for policy and practice, including the importance of support for department-level leadership and the possibility of using the four factors to improve climate for instructional improvement through evaluation, assessment, and program review

Conservation Status of the Longhead Darter, Percina macrocephala, in Kinnicock Creek, Kentucky

Percina macrocephala, the Longhead Darter, is rare throughout its range and endangered in Kentucky. One population in Kentucky occurs in Kinniconick Creek, Lewis County, and prior to this study was known from only a few specimens, mostly collected in 1981. In summer and early fall of 2007 and 2008, 55 reaches, spanning 54 stream km of Kinniconick Creek, were surveyed by snorkeling, electrofishing, or seining for P. macrocephala. We encountered 104 individuals of P. macrocephala in a 50 stream km segment from just below the town of Kinniconick to the town of Garrison. Fifteen of the 55 sampled reaches contained P. macrocephala. Most individuals were encountered in a middle section between the confluences of Laurel Fork and Town Branch; this area also contained many young-of-the-year, indicating successful reproduction and recruitment. Although we judge this species to be rare to uncommon in most of Kinniconick Creek, it is locally common in the middle section, and the population seems to be stable and perhaps the most robust in the state. We conservatively estimate a total population of 2000-5000 in the stream. Because this population appears to be migratory, and exhibits source-sink dynamics, it is susceptible to anthropogenic barriers (e.g., culvert crossings) that prevent movements

Introduction to Paleontology Research through the Boudreaux Bend Project

https://scholarworks.moreheadstate.edu/student_scholarship_posters/1058/thumbnail.jp

Size-selective concentration of chondrules and other small particles in protoplanetary nebula turbulence

Size-selective concentration of particles in a weakly turbulent protoplanetary nebula may be responsible for the initial collection of chondrules and other constituents into primitive body precursors. This paper presents the main elements of this process of turbulent concentration. In the terrestrial planet region, both the characteristic size and size distribution of chondrules are explained. "Fluffier" particles would be concentrated in nebula regions which were at a lower gas density and/or more intensely turbulent. The spatial distribution of concentrated particle density obeys multifractal scaling}, suggesting a close tie to the turbulent cascade process. This scaling behavior allows predictions of the probability distributions for concentration in the protoplanetary nebula to be made. Large concentration factors (>10^5) are readily obtained, implying that numerous zones of particle density significantly exceeding the gas density could exist. If most of the available solids were actually in chondrule sized particles, the ensuing particle mass density would become so large that the feedback effects on gas turbulence due to mass loading could no longer be neglected. This paper describes the process, presenting its basic elements and some implications, without including the effects of mass loading.Comment: 34 pages, 7 figures; in press for Astrophys. J; expected Jan 01 2001 issu

Reproductive Biology of the Frecklebelly Darter, Percina stictogaster (Teleostei: Percidae)

The reproductive biology of the Frecklebelly Darter, Percina stictogaster, was studied in the Red River, Menifee-Powell counties, Kentucky, from 2009-2012. Males and females mature at Age II. Spawning occurs from late February to early April in water temperatures of 7-16° C in areas with strong current (0.16-0.88 m/sec) and fine gravel substrates. A 52 mm SL female collected in early March had 100 mature ova. Aquarium observations confirm this species buries its eggs in a manner similar to other Percina darters. Fertilized eggs were about 2.5 mm in diameter, clear, demersal, and slightly adhesive. At 10° C eggs hatched in 18-25 days (100% survival) into larvae 7-8 mm TL. Larvae were initially benthic, but became pelagic 2- 3 days later. By about 11 mm TL, the yolk sac was absorbed, and the young returned to the bottom. In early June, young (about 2 months old) were 16-25 mm SL and had acquired diagnostic pigmentation. They occupied areas with Justicia sp. or coarse woody debris in low-velocity habitats, adjacent to riffles

Interactions Between Tachykinins And Diverse Human Nicotinic Acetylcholine Receptor Subtypes

Nicotinic acetylcholine receptors (nAChR) are diverse members of the ligand-gated ion channel superfamily of neurotransmitter receptors and play critical roles in chemical signaling throughout the nervous system. Reports of effects of substance P (SP) on nAChR function prompted us to investigate interactions between several tachykinins and human nAChR subtypes using clonal cell lines as simple experimental models. Acute exposure to SP inhibits carbamylcholine- or nicotine-stimulated function measured using 86Rb + efflux assays of human ganglionic (α3β4) nAChR expressed in SH- SY5Y neuroblastoma cells (IC 50 ~ 2.3 μM) or of human muscle-type (α1β1γδ) nAChR expressed in TE671/RD clonal cells (IC 50 ~ 21 μM). SP also acutely blocks function of rat ganglionic nAChR expressed in PC12 pheochromocytoma cells (IC 50 ~ 2.1 μM). Neurokinin A and eledoisin inhibit function (extrapolated IC 50 values between 60 and 160 μM) of human muscle-type or ganglionic nAChR, but neurokinin B does not, and neither human nAChR is as sensitive as PC12 cell α3β4-nAChR to eledoisin or neurokinin A inhibition. At concentrations that produce blockade of nAChR function, SP fails to affect binding of [ 3H]acetylcholine to human muscle-type or ganglionic nAChR. SP-mediated blockade of rat or human ganglionic nAChR function is insurmountable by increasing agonist concentrations. Collectively, these results indicate that tachykinins act noncompetitively to inhibit human nAChR function with potencies that vary across tachykinins and nAChR subtypes. They also indicate that tachykinin actions at nAChR could further contribute to complex cross-talk between nicotinic cholinergic and tachykinin signals in regulation of nervous system activity

Conservation Status of the Longhead Darter, Percina macrocephala, in Kinnicock Creek, Kentucky

Percina macrocephala, the Longhead Darter, is rare throughout its range and endangered in Kentucky. One population in Kentucky occurs in Kinniconick Creek, Lewis County, and prior to this study was known from only a few specimens, mostly collected in 1981. In summer and early fall of 2007 and 2008, 55 reaches, spanning 54 stream km of Kinniconick Creek, were surveyed by snorkeling, electrofishing, or seining for P. macrocephala. We encountered 104 individuals of P. macrocephala in a 50 stream km segment from just below the town of Kinniconick to the town of Garrison. Fifteen of the 55 sampled reaches contained P. macrocephala. Most individuals were encountered in a middle section between the confluences of Laurel Fork and Town Branch; this area also contained many young-of-the-year, indicating successful reproduction and recruitment. Although we judge this species to be rare to uncommon in most of Kinniconick Creek, it is locally common in the middle section, and the population seems to be stable and perhaps the most robust in the state. We conservatively estimate a total population of 2000-5000 in the stream. Because this population appears to be migratory, and exhibits source-sink dynamics, it is susceptible to anthropogenic barriers (e.g., culvert crossings) that prevent movements