4,164 research outputs found

    Chorusing, synchrony, and the evolutionary functions of rhythm

    No full text
    A central goal of biomusicology is to understand the biological basis of human musicality. One approach to this problem has been to compare core components of human musicality (relative pitch perception, entrainment, etc.) with similar capacities in other animal species. Here we extend and clarify this comparative approach with respect to rhythm. First, whereas most comparisons between human music and animal acoustic behavior have focused on spectral properties (melody and harmony), we argue for the central importance of temporal properties, and propose that this domain is ripe for further comparative research. Second, whereas most rhythm research in non-human animals has examined animal timing in isolation, we consider how chorusing dynamics can shape individual timing, as in human music and dance, arguing that group behavior is key to understanding the adaptive functions of rhythm. To illustrate the interdependence between individual and chorusing dynamics, we present a computational model of chorusing agents relating individual call timing with synchronous group behavior. Third, we distinguish and clarify mechanistic and functional explanations of rhythmic phenomena, often conflated in the literature, arguing that this distinction is key for understanding the evolution of musicality. Fourth, we expand biomusicological discussions beyond the species typically considered, providing an overview of chorusing and rhythmic behavior across a broad range of taxa (orthopterans, fireflies, frogs, birds, and primates). Finally, we propose an “Evolving Signal Timing” hypothesis, suggesting that similarities between timing abilities in biological species will be based on comparable chorusing behaviors. We conclude that the comparative study of chorusing species can provide important insights into the adaptive function(s) of rhythmic behavior in our “proto-musical” primate ancestors, and thus inform our understanding of the biology and evolution of rhythm in human music and language

    Concentration, temperature, and density in a hydrogen-air flame by excimer-induced Raman scattering

    Get PDF
    Single-pulse, vibrational Raman scattering (VRS) is an attractive laser diagnostic for the study of supersonic hydrogen-air combustion. The VRS technique gives a complete thermodynamic description of the gas mixture at a point in the reacting flow. Single-pulse, vibrational Raman scattering can simultaneously provide independent measurements of density, temperature, and concentration of each major species (H2, H2O, O2 and N2) in a hydrogen/air turbulent combustor. Also the pressure can be calculated using the ideal gas law. However, single-pulse VRS systems in current use for measurement of turbulent combustion have a number of shortcomings when applied to supersonic flows: (1) slow repetition rate (1 to 5 Hz), (2) poor spatial resolution (0.5x0.3x0.3 cu mm), and (3) marginal time resolution. Most of these shortcomings are due to the use of visible wavelength flash-lamp pumped dye lasers. The advent of UV excimer laser allows the possibility of dramatic improvements in the single-pulse, vibrational Raman scattering. The excimer based VRS probe will greatly improve repetition rate (100 to 500 Hz), spatial resolution (0.1x0.1x0.1 cu mm) and time resolution (30ns). These improvements result from the lower divergence of the UV excimer, higher repetition rate, and the increased Raman cross-sections (15 to 20 times higher) at ultra-violet (UV) wavelengths. With this increased capability, single-pulse vibrational Raman scattering promises to be an ideal non-intrusive probe for the study of hypersonic propulsion flows

    Dual Credit in Southeast Kentucky: Accelerating Appalachian Success or a Mode to Regress

    Get PDF
    This dissertation is a qualitative study about high school student participation in dual credit programming in the rural Appalachian setting of Southeastern Kentucky. The research region is comprised of resource extraction based communities and the coal markets have plummeted. Void the once robust coal industry, Southeast Kentucky will have to reconstruct a new economy. Today’s students in this region can no longer be prepared to enter an established workforce, they must be able to acclimate to and/or forge new jobs. Sustainability requires a refocusing on education. This dissertation provides a qualitative research contribution to the statistical literature available on Kentucky’s rural Appalachian dual credit programming. This study examined levels of student engagement in the regional service area of Southeast Kentucky Community and Technical Colleges’ current Dual Credit programming, the benefits associated with enrolling in dual credit courses, and exploration of barriers that prevent student dual credit enrollment or impair their performance. This study identifies five key components of dual credit that have an impact on student participation and performance. Also, triangulation methods were incorporated to evaluate research validly and establish areas of interest for further study. Finally, this dissertation describes how a local college and high school collaboration is becoming a powerful influence in encouraging youth to challenge themselves and achieve

    What Early Career Teachersí Evaluations of Video-≠-based Cases of Reading Lessons Reveal about Analytic Expertise.

    Full text link
    Supporting the development of expertise for teachers of reading, especially beginning teachers, is a significant need in our educational system (Snow, Griffin, Burns, 2005). Analytic expertise is one dimension of teaching expertise, involving the ability to 1) assess whether students achieve specified learning goals, and 2) identify how and why instruction did or did not affect this achievement (Hiebert, Morris, Berk, & Jansen, 2007). Systematic and guided lesson analysis is a promising approach to helping beginning teachers develop their analytic expertise (Ball & Cohen, 1999; Bransford, Derry, Berliner, Hammerness, & Beckett, 2005; Hiebert et al., 2007). However, little is known about beginning teachers’ analytic expertise in the context of reading instruction or how it develops through lesson analysis. Therefore, the aim of this study is to investigate beginning teachers’ analytic expertise in the context of lesson analysis. This dissertation study presents the analysis of four elementary teachers’ evaluations of their own early reading instruction and other teachers’ instruction using a lesson analysis tool, Cases Studies of Reading Lessons (CSRL). CSRL offers a set of tools designed to draw teachers’ attention to effective aspects of early reading instruction. Participants viewed and evaluated the effectiveness of lessons presented in CSRL. Before and after engaging with the CSRL cases, participants evaluated video-taped lessons of their own teaching, noting effective features and features that need improvement. Utilizing indices of analytic expertise established by prior expert/novice studies, evaluations of instruction were coded to investigate participants’ analyses. Most participants began the study exhibiting indices of less-developed analytic expertise. However, all four participants experienced shifts in indices of analytic expertise over the course of the study. For example participants (a) discussed more significant and relevant features of instruction, (b) discussed fewer features of instruction, and (c) provided more principles of teaching and learning. However, the least experienced participant’s analytic expertise shifted more than the other participants. The results of this study shed light on the nature of beginning teachers’ analytic expertise and on the role of analysis tools, such as CSRL, in supporting the development of this expertise.PhDEducational StudiesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113519/1/emihocko_1.pd

    River Discharge, in State of the Climate in 2008

    Get PDF
    The global mean temperature in 2008 was slightly cooler than that in 2007; however, it still ranks within the 10 warmest years on record. Annual mean temperatures were generally well above average in South America, northern and southern Africa, Iceland, Europe, Russia, South Asia, and Australia. In contrast, an exceptional cold outbreak occurred during January across Eurasia and over southern European Russia and southern western Siberia. There has been a general increase in land-surface temperatures and in permafrost temperatures during the last several decades throughout the Arctic region, including increases of 1° to 2°C in the last 30 to 35 years in Russia. Record setting warm summer (JJA) air temperatures were observed throughout Greenland

    U.S. River Discharge for 2008 in State of the Climate in 2008

    Get PDF
    The global mean temperature in 2008 was slightly cooler than that in 2007; however, it still ranks within the 10 warmest years on record. Annual mean temperatures were generally well above average in South America, northern and southern Africa, Iceland, Europe, Russia, South Asia, and Australia. In contrast, an exceptional cold outbreak occurred during January across Eurasia and over southern European Russia and southern western Siberia. There has been a general increase in land-surface temperatures and in permafrost temperatures during the last several decades throughout the Arctic region, including increases of 1° to 2°C in the last 30 to 35 years in Russia. Record setting warm summer (JJA) air temperatures were observed throughout Greenland

    Towards robust teams with many agents

    Get PDF
    • …
    corecore