74 research outputs found
Vocal Learning and Auditory-Vocal Feedback
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
Passerine Birds Breeding under Chronic Noise Experience Reduced Fitness
Background
Fitness in birds has been shown to be negatively associated with anthropogenic noise, but the underlying mechanisms remain obscure. It is however crucial to understand the mechanisms of how urban noise impinges on fitness to obtain a better understanding of the role of chronic noise in urban ecology. Here, we examine three hypotheses on how noise might reduce reproductive output in passerine birds: (H1) by impairing mate choice, (H2) by reducing territory quality and (H3) by impeding chick development.
Methodology/Principal Findings
We used long-term data from an island population of house sparrows, Passer domesticus, in which we can precisely estimate fitness. We found that nests in an area affected by the noise from large generators produced fewer young, of lower body mass, and fewer recruits, even when we corrected statistically for parental genetic quality using a cross-fostering set-up, supporting H3. Also, individual females provided their young with food less often when they bred in the noisy area compared to breeding attempts by the same females elsewhere. Furthermore, we show that females reacted flexibly to increased noise levels by adjusting their provisioning rate in the short term, which suggests that noise may be a causal factor that reduces reproductive output. We rejected H1 and H2 because nestbox occupancy, parental body mass, age and reproductive investment did not differ significantly between noisy and quiet areas.
Conclusions/Significance
Our results suggest a previously undescribed mechanism to explain how environmental noise can reduce fitness in passerine birds: by acoustically masking parent–offspring communication. More importantly, using a cross-fostering set-up, our results demonstrate that birds breeding in a noisy environment experience significant fitness costs. Chronic noise is omnipresent around human habitation and may produces similar fitness consequences in a wide range of urban bird species
Local diversity in settlement, demography and subsistence across the southern Indian Neolithic-Iron Age transition: site growth and abandonment at Sanganakallu-Kupgal
The Southern Indian Neolithic-Iron Age transition demonstrates considerable regional variability in settlement location, density, and size. While researchers have shown that the region around the Tungabhadra and Krishna River basins displays significant subsistence and demographic continuity, and intensification, from the Neolithic into the Iron Age ca. 1200 cal. BC, archaeological and chronometric records in the Sanganakallu region point to hilltop village expansion during the Late Neolithic and ‘Megalithic’ transition period (ca. 1400–1200 cal. BC) prior to apparent abandonment ca. 1200 cal. BC, with little evidence for the introduction of iron technology into the region. We suggest that the difference in these settlement histories is a result of differential access to stable water resources during a period of weakening and fluctuating monsoon across a generally arid landscape. Here, we describe well-dated, integrated chronological, archaeobotanical, archaeozoological and archaeological survey datasets from the Sanganakallu-Kupgal site complex that together demonstrate an intensification of settlement, subsistence and craft production on local hilltops prior to almost complete abandonment ca. 1200 cal. BC. Although the southern Deccan region as a whole may have witnessed demographic increase, as well as subsistence and cultural continuity, at this time, this broader pattern of continuity and resilience is punctuated by local examples of abandonment and mobility driven by an increasing practical and political concern with water
Contacts in the last 90,000 years over the Strait of Gibraltar evidenced by genetic analysis of wild boar (Sus scrofa)
[EN] Contacts across the Strait of Gibraltar in the Pleistocene have been studied in different research papers, which have demonstrated that this apparent barrier has been permeable to human and fauna movements in both directions. Our study, based on the genetic analysis of wild boar (Sus scrofa), suggests that there has been contact between Africa and Europe through the Strait of Gibraltar in the Late Pleistocene (at least in the last 90,000 years), as shown by the partial analysis of mitochondrial DNA. Cytochrome b and the control region from North African wild boar indicate a close relationship with European wild boar, and even some specimens belong to a common haplotype in Europe. The analyses suggest the transformation of the wild boar phylogeography in North Africa by the emergence of a natural communication route in times when sea levels fell due to climatic changes, and possibly through human action, since contacts coincide with both the Last Glacial period and the increasing human dispersion via the strait.This study was supported by The Emirates Centre for Wildlife Propagation (Morocco). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Soria-Boix, C.; Donat-Torres, MP.; Urios, V. (2017). Contacts in the last 90,000 years over the Strait of Gibraltar evidenced by genetic analysis of wild boar (Sus scrofa). PLoS ONE. 12(7). doi:10.1371/journal.pone.0181929S12
Multimodal Communication in a Noisy Environment: A Case Study of the Bornean Rock Frog Staurois parvus
High background noise is an impediment to signal detection and perception. We report the use of multiple solutions to improve signal perception in the acoustic and visual modality by the Bornean rock frog, Staurois parvus. We discovered that vocal communication was not impaired by continuous abiotic background noise characterised by fast-flowing water. Males modified amplitude, pitch, repetition rate and duration of notes within their advertisement call. The difference in sound pressure between advertisement calls and background noise at the call dominant frequency of 5578 Hz was 8 dB, a difference sufficient for receiver detection. In addition, males used several visual signals to communicate with conspecifics with foot flagging and foot flashing being the most common and conspicuous visual displays, followed by arm waving, upright posture, crouching, and an open-mouth display. We used acoustic playback experiments to test the efficacy-based alerting signal hypothesis of multimodal communication. In support of the alerting hypothesis, we found that acoustic signals and foot flagging are functionally linked with advertisement calling preceding foot flagging. We conclude that S. parvus has solved the problem of continuous broadband low-frequency noise by both modifying its advertisement call in multiple ways and by using numerous visual signals. This is the first example of a frog using multiple acoustic and visual solutions to communicate in an environment characterised by continuous noise
Achieving the "triple aim" for inborn errors of metabolism: a review of challenges to outcomes research and presentation of a new practice-based evidence framework
Across all areas of health care, decision makers are in pursuit of what
Berwick and colleagues have called the “triple aim”: improving patient
experiences with care, improving health outcomes, and managing
health system impacts. This is challenging in a rare disease context, as
exemplified by inborn errors of metabolism. There is a need for evaluative
outcomes research to support effective and appropriate care for
inborn errors of metabolism. We suggest that such research should
consider interventions at both the level of the health system (e.g., early
detection through newborn screening, programs to provide access to
treatments) and the level of individual patient care (e.g., orphan drugs,
medical foods). We have developed a practice-
based evidence framework
to guide outcomes research for inborn errors of metabolism.
Focusing on outcomes across the triple aim, this framework integrates
three priority themes: tailoring care in the context of clinical heterogeneity;
a shift from “urgent care” to “opportunity for improvement”;
and the need to evaluate the comparative effectiveness of emerging
and established therapies. Guided by the framework, a new Canadian
research network has been established to generate knowledge that will
inform the design and delivery of health services for patients with
inborn errors of metabolism and other rare diseases.This work was supported by a CIHR Emerging Team Grant (“Emerging
team in rare diseases: acheiving the ‘triple aim’ for inborn errors
of metabolism,” B.K. Potter, P. Chakraborty, and colleagues, 2012–
2017, grant no. TR3–119195). Current investigators and collaborators
in the Canadian Inherited Metabolic Diseases Research Network
are: B.K. Potter, P. Chakraborty, J. Kronick, D. Coyle, K. Wilson, M.
Brownell, R. Casey, A. Chan, S. Dyack, L. Dodds, A. Feigenbaum, D.
Fell, M. Geraghty, C. Greenberg, S. Grosse, A. Guttmann, A. Khan,
J. Little, B. Maranda, J. MacKenzie, A. Mhanni, F. Miller, G. Mitchell,
J. Mitchell, M. Nakhla, M. Potter, C. Prasad, K. Siriwardena, K.N.
Speechley, S. Stocker, L. Turner, H. Vallance, and B.J. Wilson. Members
of our external advisory board are D. Bidulka, T. Caulfield, J.T.R.
Clarke, C. Doiron, K. El Emam, J. Evans, A. Kemper, W. McCormack,
and A. Stephenson Julian. J. Little is supported by a Canada Research
Chair in Human Genome Epidemiology. K. Wilson is supported by a
Canada Research Chair in Public Health Policy
Synthesis, characterization, and bonding properties of polymeric fullerides AC70·nNH3 (A = Ca, Sr, Ba, Eu, Yb)
Reduction of C-70 with alkaline earth and rare earth metals
dissolved in liquid ammonia results in metal fulleride solvates
AC(70).nNH(3) (A = Ca, Sr, Ba, Eu, Yb) containing linear
polymeric, anionic chains (1)(infinity)[C-70(2-)] The compounds
were characterised by means of Raman spectroscopy and single-
crystal structure determination. The accurate crystal structure
of [Sr(NH3)(8)]C-70.3NH(3), determined with atomic resolution,
allowed for a comparison with results of quantum chemical
calculations. The nature of the C-C bonds in the fulleride is
analysed in detail leading to a model explaining the unexpected
polymerisation of C-70(2-)
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