Base de dados : MEDLINE
Pesquisa : F01.145.113.055.400 [Categoria DeCS]
Referências encontradas : 1507 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 151 ir para página                         

  1 / 1507 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29311648
[Au] Autor:Thiagavel J; Cechetto C; Santana SE; Jakobsen L; Warrant EJ; Ratcliffe JM
[Ad] Endereço:Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada.
[Ti] Título:Auditory opportunity and visual constraint enabled the evolution of echolocation in bats.
[So] Source:Nat Commun;9(1):98, 2018 01 08.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Substantial evidence now supports the hypothesis that the common ancestor of bats was nocturnal and capable of both powered flight and laryngeal echolocation. This scenario entails a parallel sensory and biomechanical transition from a nonvolant, vision-reliant mammal to one capable of sonar and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation. Further, we find that among extant predatory bats (all of which use laryngeal echolocation), those with putatively less sophisticated biosonar have relatively larger eyes than do more sophisticated echolocators. We contend that signs of ancient trade-offs between vision and echolocation persist today, and that non-echolocating, phytophagous pteropodid bats may retain some of the necessary foundations for biosonar.
[Mh] Termos MeSH primário: Percepção Auditiva/fisiologia
Quirópteros/fisiologia
Ecolocação/fisiologia
Percepção Visual/fisiologia
[Mh] Termos MeSH secundário: Animais
Evolução Biológica
Encéfalo/anatomia & histologia
Encéfalo/fisiologia
Quirópteros/anatomia & histologia
Quirópteros/classificação
Olho/anatomia & histologia
Voo Animal/fisiologia
Fenômenos Fisiológicos Oculares
Visão Ocular/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180110
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02532-x


  2 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28452520
[Au] Autor:Müller R; Gupta AK; Zhu H; Pannala M; Gillani US; Fu Y; Caspers P; Buck JR
[Ad] Endereço:Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
[Ti] Título:Dynamic Substrate for the Physical Encoding of Sensory Information in Bat Biosonar.
[So] Source:Phys Rev Lett;118(15):158102, 2017 Apr 14.
[Is] ISSN:1079-7114
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Horseshoe bats have dynamic biosonar systems with interfaces for ultrasonic emission (reception) that change shape while diffracting the outgoing (incoming) sound waves. An information-theoretic analysis based on numerical and physical prototypes shows that these shape changes add sensory information (mutual information between distant shape conformations <20%), increase the number of resolvable directions of sound incidence, and improve the accuracy of direction finding. These results demonstrate that horseshoe bats have a highly effective substrate for dynamic encoding of sensory information.
[Mh] Termos MeSH primário: Quirópteros
Ecolocação
Ultrassom
[Mh] Termos MeSH secundário: Animais
Modelos Biológicos
Localização de Som
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180209
[Lr] Data última revisão:
180209
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1103/PhysRevLett.118.158102


  3 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29240840
[Au] Autor:Ming C; Zhu H; Müller R
[Ad] Endereço:Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia, United States of America.
[Ti] Título:A simplified model of biosonar echoes from foliage and the properties of natural foliages.
[So] Source:PLoS One;12(12):e0189824, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Foliage echoes could play an important role in the sensory ecology of echolocating bats, but many aspects of their sensory information content remain to be explored. A realistic numerical model for these echoes could support the development of hypotheses for the relationship between foliage properties and echo parameters. In prior work by the authors, a simple foliage model based on circular disks distributed uniformly in space has been developed. In the current work, three key simplifications used in this model have been examined: (i) representing leaves as circular disks, (ii) neglecting shading effects between leaves, and (iii) the uniform spatial distribution of the leaves. The target strengths of individual leaves and shading between them have been examined in physical experiments, whereas the impact of the spatial leaf distribution has been studied by modifying the numerical model to include leaf distributions according to a biomimetic model for natural branching patterns (L-systems). Leaf samples from a single species (leatherleaf arrowwood) were found to match the relationship between size and target strength of the disk model fairly well, albeit with a large variability part of which could be due to unaccounted geometrical features of the leaves. Shading between leaf-sized disks did occur for distances below 50 cm and could hence impact the echoes. Echoes generated with L-system models in two distinct tree species (ginkgo and pine) showed consistently more temporal inhomogeneity in the envelope amplitudes than a reference with uniform distribution. However, these differences were small compared to effects found in response to changes in the relative orientation of simulated sonar beam and foliage. These findings support the utility of the uniform leaf distribution model and suggest that bats could use temporal inhomogeneities in the echoes to make inferences regarding the relative positioning of their sonar and a foliage.
[Mh] Termos MeSH primário: Quirópteros/fisiologia
Ecolocação/fisiologia
Modelos Teóricos
Folhas de Planta/fisiologia
[Mh] Termos MeSH secundário: Animais
Árvores
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171229
[Lr] Data última revisão:
171229
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171215
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0189824


  4 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29186147
[Au] Autor:Jacobs DS; Catto S; Mutumi GL; Finger N; Webala PW
[Ad] Endereço:University of Cape Town, Department of Biological Sciences, Rondebosch, Cape Town, South Africa.
[Ti] Título:Testing the Sensory Drive Hypothesis: Geographic variation in echolocation frequencies of Geoffroy's horseshoe bat (Rhinolophidae: Rhinolophus clivosus).
[So] Source:PLoS One;12(11):e0187769, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Geographic variation in sensory traits is usually influenced by adaptive processes because these traits are involved in crucial life-history aspects including orientation, communication, lineage recognition and mate choice. Studying this variation can therefore provide insights into lineage diversification. According to the Sensory Drive Hypothesis, lineage diversification may be driven by adaptation of sensory systems to local environments. It predicts that acoustic signals vary in association with local climatic conditions so that atmospheric attenuation is minimized and transmission of the signals maximized. To test this prediction, we investigated the influence of climatic factors (specifically relative humidity and temperature) on geographic variation in the resting frequencies of the echolocation pulses of Geoffroy's horseshoe bat, Rhinolophus clivosus. If the evolution of phenotypic variation in this lineage tracks climate variation, human induced climate change may lead to decreases in detection volumes and a reduction in foraging efficiency. A complex non-linear interaction between relative humidity and temperature affects atmospheric attenuation of sound and principal components composed of these correlated variables were, therefore, used in a linear mixed effects model to assess their contribution to observed variation in resting frequencies. A principal component composed predominantly of mean annual temperature (factor loading of -0.8455) significantly explained a proportion of the variation in resting frequency across sites (P < 0.05). Specifically, at higher relative humidity (around 60%) prevalent across the distribution of R. clivosus, increasing temperature had a strong negative effect on resting frequency. Climatic factors thus strongly influence acoustic signal divergence in this lineage, supporting the prediction of the Sensory Drive Hypothesis. The predicted future increase in temperature due to climate change is likely to decrease the detection volume in echolocating bats and adversely impact their foraging efficiency.
[Mh] Termos MeSH primário: Quirópteros/fisiologia
Ecolocação
Geografia
[Mh] Termos MeSH secundário: Animais
Mudança Climática
Feminino
Masculino
Comportamento Sexual Animal
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171226
[Lr] Data última revisão:
171226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171130
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0187769


  5 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29216184
[Au] Autor:Frasier KE; Roch MA; Soldevilla MS; Wiggins SM; Garrison LP; Hildebrand JA
[Ad] Endereço:Scripps Institution of Oceanography, La Jolla, California, United States of America.
[Ti] Título:Automated classification of dolphin echolocation click types from the Gulf of Mexico.
[So] Source:PLoS Comput Biol;13(12):e1005823, 2017 Dec.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Delphinids produce large numbers of short duration, broadband echolocation clicks which may be useful for species classification in passive acoustic monitoring efforts. A challenge in echolocation click classification is to overcome the many sources of variability to recognize underlying patterns across many detections. An automated unsupervised network-based classification method was developed to simulate the approach a human analyst uses when categorizing click types: Clusters of similar clicks were identified by incorporating multiple click characteristics (spectral shape and inter-click interval distributions) to distinguish within-type from between-type variation, and identify distinct, persistent click types. Once click types were established, an algorithm for classifying novel detections using existing clusters was tested. The automated classification method was applied to a dataset of 52 million clicks detected across five monitoring sites over two years in the Gulf of Mexico (GOM). Seven distinct click types were identified, one of which is known to be associated with an acoustically identifiable delphinid (Risso's dolphin) and six of which are not yet identified. All types occurred at multiple monitoring locations, but the relative occurrence of types varied, particularly between continental shelf and slope locations. Automatically-identified click types from autonomous seafloor recorders without verifiable species identification were compared with clicks detected on sea-surface towed hydrophone arrays in the presence of visually identified delphinid species. These comparisons suggest potential species identities for the animals producing some echolocation click types. The network-based classification method presented here is effective for rapid, unsupervised delphinid click classification across large datasets in which the click types may not be known a priori.
[Mh] Termos MeSH primário: Biologia Computacional/métodos
Golfinhos/fisiologia
Ecolocação/classificação
Reconhecimento Automatizado de Padrão/métodos
Processamento de Sinais Assistido por Computador
Vocalização Animal/classificação
[Mh] Termos MeSH secundário: Algoritmos
Animais
Golfo do México
Espectrografia do Som
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171220
[Lr] Data última revisão:
171220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171208
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1005823


  6 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28883063
[Au] Autor:Stilz P
[Ad] Endereço:Department of Animal Physiology, Institute for Neurobiology, University of Tübingen, Germany. peter.stilz@uni-tuebingen.de.
[Ti] Título:How glass fronts deceive bats.
[So] Source:Science;357(6355):977-978, 2017 09 08.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Mh] Termos MeSH primário: Quirópteros
Ecolocação
Vidro
[Mh] Termos MeSH secundário: Animais
[Pt] Tipo de publicação:JOURNAL ARTICLE; COMMENT
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171026
[Lr] Data última revisão:
171026
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170909
[St] Status:MEDLINE
[do] DOI:10.1126/science.aao2989


  7 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28863144
[Au] Autor:Peng K; Peng YJ; Wang J; Yang MJ; Fu ZY; Tang J; Chen QC
[Ad] Endereço:School of Life Sciences and Hubei Key Lab of Genetic Regulation & Integrative Biology, Central China Normal University, Wuhan, China.
[Ti] Título:Latency modulation of collicular neurons induced by electric stimulation of the auditory cortex in Hipposideros pratti: In vivo intracellular recording.
[So] Source:PLoS One;12(9):e0184097, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In the auditory pathway, the inferior colliculus (IC) receives and integrates excitatory and inhibitory inputs from the lower auditory nuclei, contralateral IC, and auditory cortex (AC), and then uploads these inputs to the thalamus and cortex. Meanwhile, the AC modulates the sound signal processing of IC neurons, including their latency (i.e., first-spike latency). Excitatory and inhibitory corticofugal projections to the IC may shorten and prolong the latency of IC neurons, respectively. However, the synaptic mechanisms underlying the corticofugal latency modulation of IC neurons remain unclear. Thus, this study probed these mechanisms via in vivo intracellular recording and acoustic and focal electric stimulation. The AC latency modulation of IC neurons is possibly mediated by pre-spike depolarization duration, pre-spike hyperpolarization duration, and spike onset time. This study suggests an effective strategy for the timing sequence determination of auditory information uploaded to the thalamus and cortex.
[Mh] Termos MeSH primário: Córtex Auditivo/fisiologia
Vias Auditivas/fisiologia
Quirópteros/fisiologia
Estimulação Elétrica
Colículos Inferiores/fisiologia
Neurônios/fisiologia
[Mh] Termos MeSH secundário: Estimulação Acústica
Acústica
Animais
Percepção Auditiva/fisiologia
Peso Corporal
Córtex Cerebral/fisiologia
Ecolocação
Feminino
Masculino
Som
Tálamo/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171023
[Lr] Data última revisão:
171023
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170902
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0184097


  8 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28859082
[Au] Autor:Thaler L; Reich GM; Zhang X; Wang D; Smith GE; Tao Z; Abdullah RSABR; Cherniakov M; Baker CJ; Kish D; Antoniou M
[Ad] Endereço:Department of Psychology, Durham University, Science Site, Durham, United Kingdom.
[Ti] Título:Mouth-clicks used by blind expert human echolocators - signal description and model based signal synthesis.
[So] Source:PLoS Comput Biol;13(8):e1005670, 2017 Aug.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Echolocation is the ability to use sound-echoes to infer spatial information about the environment. Some blind people have developed extraordinary proficiency in echolocation using mouth-clicks. The first step of human biosonar is the transmission (mouth click) and subsequent reception of the resultant sound through the ear. Existing head-related transfer function (HRTF) data bases provide descriptions of reception of the resultant sound. For the current report, we collected a large database of click emissions with three blind people expertly trained in echolocation, which allowed us to perform unprecedented analyses. Specifically, the current report provides the first ever description of the spatial distribution (i.e. beam pattern) of human expert echolocation transmissions, as well as spectro-temporal descriptions at a level of detail not available before. Our data show that transmission levels are fairly constant within a 60° cone emanating from the mouth, but levels drop gradually at further angles, more than for speech. In terms of spectro-temporal features, our data show that emissions are consistently very brief (~3ms duration) with peak frequencies 2-4kHz, but with energy also at 10kHz. This differs from previous reports of durations 3-15ms and peak frequencies 2-8kHz, which were based on less detailed measurements. Based on our measurements we propose to model transmissions as sum of monotones modulated by a decaying exponential, with angular attenuation by a modified cardioid. We provide model parameters for each echolocator. These results are a step towards developing computational models of human biosonar. For example, in bats, spatial and spectro-temporal features of emissions have been used to derive and test model based hypotheses about behaviour. The data we present here suggest similar research opportunities within the context of human echolocation. Relatedly, the data are a basis to develop synthetic models of human echolocation that could be virtual (i.e. simulated) or real (i.e. loudspeaker, microphones), and which will help understanding the link between physical principles and human behaviour.
[Mh] Termos MeSH primário: Cegueira/reabilitação
Ecolocação/fisiologia
Modelos Biológicos
Localização de Som/fisiologia
[Mh] Termos MeSH secundário: Adulto
Animais
Bases de Dados Factuais
Seres Humanos
Masculino
Meia-Idade
Boca/fisiologia
Processamento de Sinais Assistido por Computador
Espectrografia do Som
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170917
[Lr] Data última revisão:
170917
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170901
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1005670


  9 / 1507 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28817631
[Au] Autor:Ming C; Gupta AK; Lu R; Zhu H; Müller R
[Ad] Endereço:Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia, United States of America.
[Ti] Título:A computational model for biosonar echoes from foliage.
[So] Source:PLoS One;12(8):e0182824, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Since many bat species thrive in densely vegetated habitats, echoes from foliage are likely to be of prime importance to the animals' sensory ecology, be it as clutter that masks prey echoes or as sources of information about the environment. To better understand the characteristics of foliage echoes, a new model for the process that generates these signals has been developed. This model takes leaf size and orientation into account by representing the leaves as circular disks of varying diameter. The two added leaf parameters are of potential importance to the sensory ecology of bats, e.g., with respect to landmark recognition and flight guidance along vegetation contours. The full model is specified by a total of three parameters: leaf density, average leaf size, and average leaf orientation. It assumes that all leaf parameters are independently and identically distributed. Leaf positions were drawn from a uniform probability density function, sizes and orientations each from a Gaussian probability function. The model was found to reproduce the first-order amplitude statistics of measured example echoes and showed time-variant echo properties that depended on foliage parameters. Parameter estimation experiments using lasso regression have demonstrated that a single foliage parameter can be estimated with high accuracy if the other two parameters are known a priori. If only one parameter is known a priori, the other two can still be estimated, but with a reduced accuracy. Lasso regression did not support simultaneous estimation of all three parameters. Nevertheless, these results demonstrate that foliage echoes contain accessible information on foliage type and orientation that could play a role in supporting sensory tasks such as landmark identification and contour following in echolocating bats.
[Mh] Termos MeSH primário: Quirópteros/fisiologia
Ecolocação
Modelos Teóricos
Folhas de Planta/fisiologia
[Mh] Termos MeSH secundário: Animais
Som
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171016
[Lr] Data última revisão:
171016
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170818
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0182824


  10 / 1507 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28813464
[Au] Autor:Greiter W; Firzlaff U
[Ad] Endereço:Chair of Zoology, Department of Animal Sciences, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.
[Ti] Título:Representation of three-dimensional space in the auditory cortex of the echolocating bat P. discolor.
[So] Source:PLoS One;12(8):e0182461, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The auditory cortex is an essential center for sound localization. In echolocating bats, combination sensitive neurons tuned to specific delays between call emission and echo perception represent target distance. In many bats, these neurons are organized as a chronotopically organized map of echo delay. However, it is still unclear to what extend these neurons can process directional information and thereby form a three-dimensional representation of space. We investigated the representation of three-dimensional space in the auditory cortex of Phyllostomus discolor. Specifically, we hypothesized that combination sensitive neurons encoding target distance in the AC can also process directional information. We used typical echolocation pulses of P. discolor combined with simulated echoes from different positions in virtual 3D-space and measured the evoked neuronal responses in the AC of the anesthetized bats. Our results demonstrate that combination sensitive neurons in the AC responded selectively to specific positions in 3-D space. While these neurons were sharply tuned to echo delay and formed a precise target distance map, the neurons' specificity in azimuth and elevation depended on the presented sound pressure level. Our data further reveal a topographic distribution of best elevation of the combination sensitive neurons along the rostro-caudal axis i.e., neurons in the rostral part of the target distance map representing short delays prefer elevations below the horizon. Due to their spatial directionality and selectivity to specific echo delays representing target distance, combination sensitive cortical neurons are suited to encode three-dimensional spatial information.
[Mh] Termos MeSH primário: Córtex Auditivo/fisiologia
Quirópteros/fisiologia
Ecolocação
[Mh] Termos MeSH secundário: Animais
Fenômenos Eletrofisiológicos
Masculino
Neurônios/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171018
[Lr] Data última revisão:
171018
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170817
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0182461



página 1 de 151 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde