28 research outputs found

    Vocal Learning and Auditory-Vocal Feedback

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    Vocal learning is usually studied in songbirds and humans, species that can form auditory templates by listening to acoustic models and then learn to vocalize to match the template. Most other species are thought to develop vocalizations without auditory feedback. However, auditory input influences the acoustic structure of vocalizations in a broad distribution of birds and mammals. Vocalizations are dened here as sounds generated by forcing air past vibrating membranes. A vocal motor program may generate vocalizations such as crying or laughter, but auditory feedback may be required for matching precise acoustic features of vocalizations. This chapter discriminates limited vocal learning, which uses auditory input to fine-tune acoustic features of an inherited auditory template, from complex vocal learning, in which novel sounds are learned by matching a learned auditory template. Two or three songbird taxa and four or ve mammalian taxa are known for complex vocal learning. A broader range of mammals converge in the acoustic structure of vocalizations when in socially interacting groups, which qualifies as limited vocal learning. All birds and mammals tested use auditory-vocal feedback to adjust their vocalizations to compensate for the effects of noise, and many species modulate their signals as the costs and benefits of communicating vary. This chapter asks whether some auditory-vocal feedback may have provided neural substrates for the evolution of vocal learning. Progress will require more precise definitions of different forms of vocal learning, broad comparative review of their presence and absence, and behavioral and neurobiological investigations into the mechanisms underlying the skills.PostprintPeer reviewe

    Branching fraction measurements of B+->rho(+)gamma, B-0 ->rho(0)gamma, and B-0 ->omega gamma

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    We present a study of the decays B+->rho(+)gamma, B-0 ->rho(0)gamma, and B-0 ->omega gamma. The analysis is based on data containing 347x10(6) B (B) over bar events recorded with the BABAR detector at the PEP-II asymmetric B factory. We measure the branching fractions B(B+->rho(+)gamma)=(1.10(-0.33)(+0.37)+/- 0.09)x10(-6) and B(B-0 ->rho(0)gamma)=(0.79(-0.20)(+0.22)+/- 0.06)x10(-6), and set a 90% C.L. upper limit B(B-0 ->omega gamma)(rho/omega)gamma)=(1.25(-0.24)(+0.25)+/- 0.09)x10(-6), from which we determine vertical bar V-td/V-ts vertical bar=0.200(-0.020)(+0.021)+/- 0.015, where the first uncertainty is experimental and the second is theoretical

    Measurements of CP-violating asymmetries in B-0 -> a(1)(+/-)(1260)pi(-/+) decays

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    We present measurements of CP-violating asymmetries in the decay B-0 -> a(1)(+/-)(1260)pi(-/+) with a(1)(+/-)(1260)->pi(-/+)pi(+/-)pi(+/-). The data sample corresponds to 384x10(6) B(b) over bar pairs collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. We measure the CP-violating asymmetry A(CP)(a1 pi)=-0.07 +/- 0.07 +/- 0.02, the mixing-induced CP violation parameter S-a1 pi=0.37 +/- 0.21 +/- 0.07, the direct CP violation parameter C-a1 pi=-0.10 +/- 0.15 +/- 0.09, and the parameters Delta C-a1 pi=0.26 +/- 0.15 +/- 0.07 and Delta S-a1 pi=-0.14 +/- 0.21 +/- 0.06. From these measured quantities we determine the angle alpha(eff)=78.6 degrees +/- 7.3 degrees

    Communities and change in the anthropocene: understanding social-ecological vulnerability and planning adaptations to multiple interacting exposures

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    The majority of vulnerability and adaptation scholarship, policies and programs focus exclusively on climate change or global environmental change. Yet, individuals, communities and sectors experience a broad array of multi-scalar and multi-temporal, social, political, economic and environmental changes to which they are vulnerable and must adapt. While extensive theoretical-and increasingly empirical-work suggests the need to explore multiple exposures, a clear conceptual framework which would facilitate analysis of vulnerability and adaptation to multiple interacting socioeconomic and biophysical changes is lacking. This review and synthesis paper aims to fill this gap through presenting a conceptual framework for integrating multiple exposures into vulnerability analysis and adaptation planning. To support applications of the framework and facilitate assessments and comparative analyses of community vulnerability, we develop a comprehensive typology of drivers and exposures experienced by coastal communities. Our results reveal essential elements of a pragmatic approach for local-scale vulnerability analysis and for planning appropriate adaptations within the context of multiple interacting exposures. We also identify methodologies for characterizing exposures and impacts, exploring interactions and identifying and prioritizing responses. This review focuses on coastal communities; however, we believe the framework, typology and approach will be useful for understanding vulnerability and planning adaptation to multiple exposures in various social-ecological contexts

    Communities and change in the anthropocene: understanding social-ecological vulnerability and planning adaptations to multiple interacting exposures

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