Junior Recital: Mitchell Frey, trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Frey studies trombone with Tom Gibson.https://digitalcommons.kennesaw.edu/musicprograms/1458/thumbnail.jp

Species-specific effects of polyploidisation and plant traits of Centaurea maculosa and Senecio inaequidens on rhizosphere microorganisms

Invasive plant species represent a threat to terrestrial ecosystems, but their effects on the soil biota and the mechanisms involved are not yet well understood. Many invasive species have undergone polyploidisation, leading to the coexistence of various cytotypes in the native range, whereas, in most cases, only one cytotype is present in the introduced range. Since genetic variation within a species can modify soil rhizosphere communities, we studied the effects of different cytotypes and ranges (native diploid, native tetraploid and introduced tetraploid) of Centaurea maculosa and Senecio inaequidens on microbial biomass carbon, rhizosphere total DNA content and bacterial communities of a standard soil in relation to plant functional traits. There was no overall significant difference in microbial biomass between cytotypes. The variation of rhizosphere total DNA content and bacterial community structure according to cytotype was species specific. The rhizosphere DNA content of S. inaequidens decreased with polyploidisation in the native range but did not vary for C. maculosa. In contrast, the bacterial community structure of C. maculosa was affected by polyploidisation and its diversity increased, whereas there was no significant change for S. inaequidens. Traits of S. inaequidens were correlated to the rhizosphere biota. Bacterial diversity and total DNA content were positively correlated with resource allocation to belowground growth and late flowering, whereas microbial biomass carbon was negatively correlated to investment in reproduction. There were no correlations between traits of the cytotypes of C. maculosa and corresponding rhizosphere soil biota. This study shows that polyploidisation may affect rhizosphere bacterial community composition, but that effects vary among plant species. Such changes may contribute to the success of invasive polyploid genotypes in the introduced rang

Junior Recital: Joseph Poole, bass trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Poole studies bass trombone with Brian Hecht.https://digitalcommons.kennesaw.edu/musicprograms/1522/thumbnail.jp

Senior Recital: Mitchell Frey, trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Frey studies trombone with Tom Gibson.https://digitalcommons.kennesaw.edu/musicprograms/1519/thumbnail.jp

Senior Recital: David Lennertz, trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Lennertz studies trombone with Tom Gibson.https://digitalcommons.kennesaw.edu/musicprograms/1486/thumbnail.jp

Senior Recital: Tim Settineri, bass trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Music Education. Mr. Settineri studies bass trombone with Tom Gibson.https://digitalcommons.kennesaw.edu/musicprograms/1324/thumbnail.jp

Zero field muon spin lattice relaxation rate in a Heisenberg ferromagnet at low temperature

We provide a theoretical framework to compute the zero field muon spin relaxation rate of a Heisenberg ferromagnet at low temperature. We use the linear spin wave approximation. The rate, which is a measure of the spin lattice relaxation induced by the magnetic fluctuations along the easy axis, allows one to estimate the magnon stiffness constant.Comment: REVTeX 3.0 manuscript, 5 pages, no figure. Published in Phys. Rev. B 52, 9155 (1995

Senior Recital: Joseph Poole, bass trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Poole studies bass trombone with Brian Hecht.https://digitalcommons.kennesaw.edu/musicprograms/1245/thumbnail.jp

Senior Recital: Katie Riess, trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Ms. Riess studies trombone with Wes Funderburk.https://digitalcommons.kennesaw.edu/musicprograms/1194/thumbnail.jp

The remarkable vocal anatomy of the koala (Phascolarctos cinereus): insights into low-frequency sound production in a marsupial species

Koalas are characterised by a highly unusual vocal anatomy, with a descended larynx and velar vocal folds, allowing them to produce calls with disproportionately low frequencies. Here we use advanced imaging techniques, histological data, classical macroscopic dissection and behavioural observations to provide the first detailed description and interpretation of male and female koala vocal anatomy. We show that both males and females have an elongated pharynx and soft palate, resulting in a permanently descended larynx. In addition, the hyoid apparatus has a human-like configuration in which paired dorsal, resilient ligaments suspend the hyoid apparatus from the skull, while the ventral parts tightly connect to the descended larynx. We also show that koalas can retract the larynx down into the thoracic inlet, facilitated by a dramatic evolutionary transformation of the ventral neck muscles. First, the usual retractors of the larynx and the hyoid have their origins deep in the thorax. Second, three hyoid muscles have lost their connection to the hyoid skeleton. Third, the genioglossus and geniohyoid muscles have greatly increased in length. Finally, the digastric, omohyoid and sternohyoid muscles, connected by a common tendinous intersection, form a guiding channel for the dynamic down-and-up movements of the ventral hyoid parts and the larynx. We suggest that these features evolved to accommodate the low resting position of the larynx and assist in its retraction during call production. We also confirm that the edges of the intra-pharyngeal ostium have specialised to form the novel, extra-laryngeal velar vocal folds, which are much larger than the true, intra-laryngeal vocal folds in both sexes, but more developed and specialised for low frequency sound production in males than in females. Our findings illustrate that strong selection pressures on acoustic signalling not only lead to the specialisation of existing vocal organs, but can also result in the evolution of novel vocal structures in both sexes