849 research outputs found

    Developing a Rhythmic Vocabulary: Exercises Derived from the West African Influence on Jazz

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    Rhythm is largely noted as a defining characteristic of jazz, yet as jazz education has gained a more prominent role in higher education, course time and materials dedicated to rhythmic training remain scarce. As previous research has demonstrated, there is an abundance of resources and methods that emphasize harmonic elements, focusing largely on chord/scale relationships; this prevalence of materials dedicated to harmony only serves to highlight the paucity of resources related to rhythm. This study seeks to develop exercises that can supplement harmonic exercises and concepts to aid educators and performers in gaining a broader understanding of rhythm, while bolstering a performer’s rhythmic vocabulary. This is accomplished by analyzing rhythmic characteristics of West African ensemble music, the influence this music had on the development of jazz, and how the rhythmic characteristics have been manifested in modern jazz. West African ensemble music was selected because of its noted correlation on the development of jazz, as well as for the practicality the characteristics have on applying to jazz and improvised music. From this analysis, exercises were developed that can be included in classroom or applied instruction

    The Ubiquitin Proteasome System Acutely Regulates Presynaptic Protein Turnover and Synaptic Efficacy

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    AbstractBackground: The ubiquitin proteasome system (UPS) mediates regulated protein degradation and provides a mechanism for closely controling protein abundance in spatially restricted domains within cells. We hypothesized that the UPS may acutely determine the local concentration of key regulatory proteins at neuronal synapses as a means for locally modulating synaptic efficacy and the strength of neurotransmission communication.Results: We investigated this hypothesis at the Drosophila neuromuscular synapse by using an array of genetic and pharmacological tools. This study demonstrates that UPS components are present in presynaptic boutons and that the UPS functions locally in the presynaptic compartment to rapidly eliminate a conditional transgenic reporter of proteasome activity. We assayed a panel of synaptic proteins to determine whether the UPS acutely regulates the local abundance of native synaptic targets. Both acute pharmacological inhibition of the proteasome (<1 hr) and targeted genetic perturbation of proteasome function in the presynaptic neuron cause the specific accumulation of the essential synaptic vesicle-priming protein DUNC-13. Most importantly, acute pharmacological inhibition of the proteasome (<1 hr) causes a rapid strengthening of neurotransmission (an approximately 50% increase in evoked amplitude) because of increased presynaptic efficacy. The proteasome-dependent regulation of presynaptic protein abundance, both of the exogenous reporter and native DUNC-13, and the modulation of presynaptic neurotransmitter release occur on an intermediate, rapid (tens of minutes) timescale.Conclusions: Taken together, these studies demonstrate that the UPS functions locally within synaptic boutons to acutely control levels of presynaptic protein and that the rate of UPS-dependent protein degradation is a primary determinant of neurotransmission strength

    Downmodulation of CCR7 by HIV-1 Vpu Results in Impaired Migration and Chemotactic Signaling within CD4+ T Cells

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    SummaryThe chemokine receptor CCR7 plays a crucial role in the homing of central memory and naive T cells to peripheral lymphoid organs. Here, we show that the HIV-1 accessory protein Vpu downregulates CCR7 on the surface of CD4+ T cells. Vpu and CCR7 were found to specifically interact and colocalize within the trans-Golgi network, where CCR7 is retained. Downmodulation of CCR7 did not involve degradation or endocytosis and was strictly dependent on Vpu expression. Stimulation of HIV-1-infected primary CD4+ T cells with the CCR7 ligand CCL19 resulted in reduced mobilization of Ca2+, reduced phosphorylation of Erk1/2, and impaired migration toward CCL19. Specific amino acid residues within the transmembrane domain of Vpu that were previously shown to be critical for BST-2 downmodulation (A14, A18, and W22) were also necessary for CCR7 downregulation. These results suggest that BST-2 and CCR7 may be downregulated via similar mechanisms
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