3,560 research outputs found
Ecomorphological Variation in Three Species of Cybotoid Anoles
© 2018 by The Herpetologists' League, Inc. Caribbean Anolis lizards exhibit a complex suite of ecological, morphological, and behavioral traits that allow their specialization to particular microhabitats. These microhabitat specialists, called ecomorphs, have independently evolved on the four islands of the Greater Antilles, and diversification among anole ecomorphs has been the focus of many studies. Yet, habitat specialization has also occurred among species within the same ecomorph group. Here, we examined ecological, morphological, and behavioral divergence in three Hispaniolan trunk-ground species, the cybotoid anoles: Anolis cybotes, A. marcanoi, and A. longitibialis. We found differences in limb morphology, locomotor behavior, and perch use among the three cybotoid species that mirror differences across the ecomorphs. Among these species of cybotoids, those that have longer limbs tend to move less frequently, occupy broader perches, and have smaller fourth toes with fewer lamellae. We also observed that the species with greater male-biased size dimorphism had larger heads, smaller dewlaps, and smaller testes. These results are consistent with the predictions of sexual selection theory, in that species with large male body size may have larger heads because of increased male-male combat, and smaller testes potentially attributable to a trade-off between pre- and postcopulatory selection. Overall, our study suggests that a combination of local adaptation to different structural habitats and sexual selection might produce ecomorphological diversification within cybotoid anoles of the same ecomorph group
Slaves, Soldiers, Citizens: African American Artifacts of the Civil War Era
Based on the exhibit Slaves, Soldiers, Citizens: African American Artifacts of the Civil War Era, this book provides the full experience of the exhibit, which was on display in Special Collections at Musselman Library November 2012- December 2013. It also includes several student essays based on specific artifacts that were part of the exhibit.
Table of Contents:
Introduction Angelo Scarlato, Lauren Roedner ’13 & Scott Hancock
Slave Collars & Runaways: Punishment for Rebellious Slaves Jordan Cinderich ’14
Chancery Sale Poster & Auctioneer’s Coin: The Lucrative Business of Slavery Tricia Runzel ’13
Isaac J. Winters: An African American Soldier from Pennsylvania Who Fought at Petersburg Avery Lentz ’14
Basil Biggs: A Prominent African American in Gettysburg after the Battle Lauren Roedner ’13
Linton Ingram: A Former Slave Who Became a Notable African American Educator in Georgia Brian Johnson & Lincoln Fitch ’14
Uncle Tom’s Cabin Theatre Poster: Racism in Post-Emancipation Entertainment Michelle Seabrook ’13
Essay Bibliographies
Grand Army of the Republic
Exhibit Inventory
Acknowledgmentshttps://cupola.gettysburg.edu/libexhibits/1001/thumbnail.jp
Sunflower Treated with Avipel (Anthraquinone) Bird Repellent
Maturing sunflower (Helianthus annuus L.) is susceptible to damage by birds, especially blackbirds (Agelaius phoeniceus and Quiscalus quiscula). The National Sunflower Association (NSA) identified Blackbird damage as a major issue in the production of sunflower throughout the US. In 2007 bird damage was identified as the number one yield limiting factor in 9% of surveyed fields in North Dakota (Graph 1)
Sunflower Treated with Avipel (Anthraquinone) Bird Repellent
Maturing sunflower (Helianthus annuus L.) is susceptible to damage by birds, especially blackbirds (Agelaius phoeniceus and Quiscalus quiscula). The National Sunflower Association (NSA) identified Blackbird damage as a major issue in the production of sunflower throughout the US. In 2007 bird damage was identified as the number one yield limiting factor in 9% of surveyed fields in North Dakota (Graph 1)
Gauge invariant grid discretization of Schr\"odinger equation
Using the Wilson formulation of lattice gauge theories, a gauge invariant
grid discretization of a one-particle Hamiltonian in the presence of an
external electromagnetic field is proposed. This Hamiltonian is compared both
with that obtained by a straightforward discretization of the continuous
Hamiltonian by means of balanced difference methods, and with a tight-binding
Hamiltonian. The proposed Hamiltonian and the balanced difference one are used
to compute the energy spectrum of a charged particle in a two-dimensional
parabolic potential in the presence of a perpendicular, constant magnetic
field. With this example we point out how a "naive" discretization gives rise
to an explicit breaking of the gauge invariance and to large errors in the
computed eigenvalues and corresponding probability densities; in particular,
the error on the eigenfunctions may lead to very poor estimates of the mean
values of some relevant physical quantities on the corresponding states. On the
contrary, the proposed discretized Hamiltonian allows a reliable computation of
both the energy spectrum and the probability densities.Comment: 7 pages, 4 figures, discussion about tight-binding Hamiltonians adde
Impact of Intercollegiate Athletics on Undergraduate Enrollment at a Small, Faith-Based Institution
Based on previous research, it is apparent many National Collegiate Athletic Association (NCAA) Division I institutions benefit from the existence of and success in intercollegiate athletics. However, few studies have researched the impact of intercollegiate athletics at National Association of Intercollegiate Athletics (NAIA) institutions. Therefore, the purpose of this study was to investigate the effect of intercollegiate athletics at a small, faith-based institution affiliated with the NAIA. More specifically, does success in or the existence of intercollegiate athletics have an effect on students’ decisions to enroll at this institution? Findings indicate the majority of freshmen student participants, including many intercollegiate athletes, were not considerably influenced by the existence of intercollegiate athletics or the existence of successful intercollegiate athletics when deciding to attend the institution. These findings indicate the need for similar institutions to reevaluate the importance placed on and benefits derived from intercollegiate athletics
Convergent Evolution of Brain Morphology and Communication Modalities in Lizards
Animals communicate information within their environments via visual, chemical, auditory, and/or tactile modalities. The use of each modality is generally linked to particular brain regions, but it is not yet known whether the cellular morphology of neurons in these regions has evolved in association with the relative use of a modality. We investigated relationships between the behavioral use of communication modalities and neural morphologies in six lizard species. Two of these species (Anolis carolinensis and Leiocephalus carinatus) primarily use visual signals to communicate with conspecifics and detect potential prey, and two (Aspidoscelis gularis and Scincella lateralis) communicate and forage primarily using chemical signals. Two other species (Hemidactylus turcicus and Sceloporus olivaceus) use both visual and chemical signals. For each species, we performed behavioral observations and quantified rates of visual and chemical behaviors. We then cryosectioned brain tissues from 9-10 males of each species and measured the soma size and density of neurons in two brain regions associated with visual behaviors (the lateral geniculate nucleus and the nucleus rotundus) and one region associated with chemical behaviors (the nucleus sphericus). With analyses conducted in a phylogenetic context, we found that species that performed higher rates of visual displays had a denser lateral geniculate nucleus, and species that used a higher proportion of chemical displays had larger somas in the nucleus sphericus. These relationships suggest that neural morphologies in the brain have evolved convergently in species with similar communication behaviors
Effects of Human Land Use on Prey Availability and Body Condition in the Green Anole Lizard, \u3cem\u3eAnolis carolinensis\u3c/em\u3e
Lizards frequently occur in disturbed habitats, yet the impacts of human activity on lizard biology remain understudied. Here, we examined the effects of land use on the body condition of Green Anole lizards (Anolis carolinensis) and the availability of their arthropod prey. Because human activity generally alters abiotic and biotic habitat features, we predicted that areas modified by humans would differ from areas with natural, intact vegetation in arthropod abundance and biomass. In addition, because biological communities in high use areas are often relatively homogenized, we predicted that higher human land use would result in lower prey diversity. Regardless of land use, we also predicted that areas with greater prey availability and diversity would support lizards with higher body condition. We studied anoles in six plots with varying levels of human modification in Palmetto State Park in Gonzales County, Texas. We quantified arthropod abundance, biomass, and diversity in each plot via transects and insect traps. We also determined lizard body condition using mass:length ratios and residuals, fat pad mass, and liver lipid content. We found that, although arthropod abundance did not differ across plots, arthropod biomass was higher in natural than in disturbed plots. Diversity indices showed that the plots varied in their arthropod community diversity, but not in relation to disturbance. Female (but not male) lizard body condition differed across plots, with body condition higher in natural plots than disturbed plots. Together, these results suggest that land use is associated with lizard body condition, but not through a direct relationship with prey availability
A Pilot Intervention to Increase Parent-Child Communication About Alcohol Avoidance
Enhancing parent-child communication regarding alcohol use through educational print correspondence is a potentially cost-effective tool in health promotion. The purpose of this pilot study was to examine whether a series of postcards addressing specific alcohol risk and protective factors, sent to the parents/guardians of preadolescents in two different school settings, influenced parent-child communication regarding alcohol use. Subjects for this study included parents of participating 6th grade students attending one neighborhood (N=262) and one magnet (bused) (N=388) inner-city school. Participating students were randomly assigned to the intervention or control group. Baseline data were collected from students, enabling the intervention to be tailored to students\u27 individual needs. Parents of students assigned to the intervention were mailed up to 10 prevention postcards over five weeks. Parents completed a 10-item telephone survey eight weeks after implementation of the prevention postcards. The overall parent response rate was 74% (N=478). Results of this pilot intervention found that postcards increased parent-child communication regarding alcohol use, but that these efects difered by school setting and race. Although significant efects were found for the intervention group, further analysis revealed that efects were found only for White parents at the magnet school. Discussion of these differences and implications for research and educational programming are provided
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