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Rose EM, Prior NH, Ball GF. The singing question: re-conceptualizing birdsong. Biol Rev Camb Philos Soc 2021; 97:326-342. [PMID: 34609054 DOI: 10.1111/brv.12800] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/31/2023]
Abstract
Birdsong has been the subject of broad research from a variety of sub-disciplines and has taught us much about the evolution, function, and mechanisms driving animal communication and cognition. Typically, birdsong refers to the specialized vocalizations produced by oscines. Historically, much of the research on birdsong was conducted in north temperate regions (specifically in Europe and North America) leading to multiple biases. Due to these historic biases these vocalizations are generally considered to be highly sexually dimorphic, heavily shaped by sexual selection and essential for courtship and territoriality. Song is also typically defined as a learned trait shaped by cultural evolution. Together, this framework focuses research specifically on males, particularly during the north temperate breeding season - reflecting and thereby reinforcing this framework. The physiological underpinnings of song often emphasize the role of the hypothalamic-pituitary-gonadal axis (associated with breeding changes) and the song control system (underlying vocal learning). Over the years there has been great debate over which features of song are essential to the definition of birdsong, which features apply broadly to contexts outside males in the north temperate region, and over the importance of having a definition at all. Importantly, the definitions we use can both guide and limit the progress of research. Here, we describe the history of these definitions, and how these definitions have directed and restricted research to focus on male song in sexually selected contexts. Additionally, we highlight the gaps in our scientific knowledge, especially with respect to the function and physiological mechanisms underlying song in females and in winter, as well as in non-seasonally breeding species. Furthermore, we highlight the problems with using complexity and learning as dichotomous variables to categorize songs and calls. Across species, no one characteristic of song - sexual dimorphism, seasonality, complexity, sexual selection, learning - consistently delineates song from other songbird vocal communication. We provide recommendations for next steps to build an inclusive information framework that will allow researchers to explore nuances in animal communication and promote comparative research. Specifically, we recommend that researchers should operationalize the axis of variation most relevant to their study/species by identifying their specific question and the variable(s) of focus (e.g. seasonality). Researchers should also identify the axis (axes) of variation (e.g. degree of control by testosterone) most relevant to their study and use language consistent with the question and axis (axes) of variation (e.g. control by testosterone in the seasonal vocal production of birds).
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Affiliation(s)
- Evangeline M Rose
- Department of Psychology, University of Maryland, College Park, 4094 Campus Dr., College Park, MD, 20742, U.S.A.,Program in Neuroscience and Cognitive Science, University of Maryland, College Park, 0219 Cole Student Activities Building, 4090 Union Drive, College Park, MD, 20742, U.S.A
| | - Nora H Prior
- Department of Psychology, University of Maryland, College Park, 4094 Campus Dr., College Park, MD, 20742, U.S.A.,Program in Neuroscience and Cognitive Science, University of Maryland, College Park, 0219 Cole Student Activities Building, 4090 Union Drive, College Park, MD, 20742, U.S.A
| | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park, 4094 Campus Dr., College Park, MD, 20742, U.S.A.,Program in Neuroscience and Cognitive Science, University of Maryland, College Park, 0219 Cole Student Activities Building, 4090 Union Drive, College Park, MD, 20742, U.S.A
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Jalabert C, Ma C, Soma KK. Profiling of systemic and brain steroids in male songbirds: Seasonal changes in neurosteroids. J Neuroendocrinol 2021; 33:e12922. [PMID: 33314446 DOI: 10.1111/jne.12922] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 11/13/2020] [Accepted: 11/14/2020] [Indexed: 12/11/2022]
Abstract
Steroids are secreted by the gonads and adrenal glands into the blood to modulate neurophysiology and behaviour. In addition, the brain can metabolise circulating steroids and synthesise steroids de novo. Songbirds show high levels of neurosteroid synthesis. In the present study, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the measurement of 10 steroids in whole blood, plasma and microdissected brain tissue (1-2 mg) of song sparrows. Our assay is highly accurate, precise, specific and sensitive. Moreover, the liquid-liquid extraction is fast, simple and effective. We quantified steroids in the blood and brain of wild male song sparrows in both breeding and non-breeding seasons. As expected, systemic androgen levels were higher in the breeding season than in the non-breeding season. Brain androgens were detectable only in the breeding season; androstenedione and 5α-dihydrotestosterone levels were up to 20-fold higher in specific brain regions than in blood. Oestrogens were not detectable in blood in both seasons. Oestrone and 17β-oestradiol were detectable in brain in the breeding season only (up to 1.4 ng g-1 combined). Progesterone levels in several regions were higher in the non-breeding season than the breeding season, despite the lack of seasonal changes in systemic progesterone. Corticosterone levels in the blood were higher in the breeding season than in the non-breeding season but showed few seasonal differences in the brain. In general, the steroid levels presented here are lower than those in previous reports using immunoassays, because of the higher specificity of mass spectrometry. We conclude that (i) brain steroid levels can differ greatly from circulating steroid levels and (ii) brain steroid levels show region-specific seasonal patterns that are not a simple reflection of circulating steroid levels. This approach using ultrasensitive LC-MS/MS is broadly applicable to other species and allows steroid profiling in microdissected brain regions.
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Affiliation(s)
- Cecilia Jalabert
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Chunqi Ma
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada
| | - Kiran K Soma
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada
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Prior NH, Fernandez MSA, Soula HA, Vignal C. Water restriction influences intra-pair vocal behavior and the acoustic structure of vocalisations in the opportunistically breeding zebra finch (Taeniopygia guttata). Behav Processes 2019; 162:147-156. [PMID: 30825505 DOI: 10.1016/j.beproc.2019.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 02/12/2019] [Accepted: 02/26/2019] [Indexed: 12/27/2022]
Abstract
Seasonally-breeding species experience significant and predictable shifts in vocal behaviour; however, it is unclear to what extent this is true for species that breed opportunistically. The Australian zebra finch is an opportunistically breeding species, which means individuals must time breeding bouts based on many environmental factors. Here we tested the effect of experimental water restriction, which suppresses reproductive readiness in zebra finches, on vocal behaviour of males and females. More specifically, we quantified the effect of water restriction on three parameters of vocal behaviour in pair-bonded zebra finches: vocal activity, patterns of vocal exchanges, and the acoustic structure of vocalisations (calls and male song). We found that water restriction caused a decrease in vocal output (both song and call rate). Additionally, water restriction affected the composition of male songs. However, there was no effect of water restriction on the patterns of calling exchanges for monogamous partners (temporal coordination and turn taking). Finally, water restriction had vocalisation- and sex-specific effects on the acoustic structure of song syllables and calls. Because the direction of these effects were vocalisation- and sex- specific, there may be different mechanisms underlying the effects of water restriction on acoustic structure depending on context. These results contribute to the growing body of research highlighting the rich communicative potential of bird calls. Our current results raise the hypothesis that zebra finches may use changes in vocal behaviour and/or the structure of vocalisations of their conspecifics when making breeding decisions.
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Affiliation(s)
- Nora H Prior
- Univ Lyon, UJM-Saint-Etienne, CNRS, Neuro-PSI/ENES UMR 9197, F-42023, SAINT-ETIENNE, France; Biology/ Psychology Departments, University of Maryland, College Park, USA.
| | - Marie S A Fernandez
- Univ Lyon, UJM-Saint-Etienne, CNRS, Neuro-PSI/ENES UMR 9197, F-42023, SAINT-ETIENNE, France; Univ Lyon, INRIA, Beagle, F-69100, Villeurbanne, France
| | - Hédi A Soula
- Univ Lyon, INRIA, Beagle, F-69100, Villeurbanne, France; Sorbonne Université, Inserm UMRS 1138, F-75006, Paris, France
| | - Clémentine Vignal
- Sorbonne Université, CNRS, Institute of Ecology and Environmental Sciences UMR 7618, F-75005 Paris, France
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Pradhan DS, Ma C, Schlinger BA, Soma KK, Ramenofsky M. Preparing to migrate: expression of androgen signaling molecules and insulin-like growth factor-1 in skeletal muscles of Gambel's white-crowned sparrows. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:113-123. [PMID: 30535830 DOI: 10.1007/s00359-018-1308-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 10/24/2018] [Accepted: 11/28/2018] [Indexed: 12/13/2022]
Abstract
Migratory birds, including Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii), exhibit profound modifications of skeletal muscles prior to migration, notably hypertrophy of the pectoralis muscle required for powered flight. Muscle growth may be influenced by anabolic effects of androgens; however, prior to spring departure, circulating androgens are low in sparrows. A seasonal increase in local androgen signaling may occur within muscle to promote remodeling. We measured morphological parameters, plasma and tissue levels of testosterone, as well as mRNA expression levels of androgen receptor, 5α-reductase (converts testosterone to 5α-dihydrotestosterone), and the androgen-dependent myotrophic factor insulin-like growth factor-1. We studied the pectoralis muscle as well as the gastrocnemius (leg) muscle of male sparrows across three stages on the wintering grounds: winter (February), pre-nuptial molt (March), and pre-departure (April). Testosterone levels were low, but detectable, in plasma and muscles at all three stages. Androgen receptor mRNA and 5α-reductase Type 1 mRNA increased at pre-departure, but did so in both muscles. Notably, mRNA levels of insulin-like growth factor-1, an androgen-dependent gene critical for muscle remodeling, increased at pre-departure in the pectoralis but decreased in the gastrocnemius. Taken together, these data suggest a site-specific molecular basis for muscle remodeling that may serve to enable long-distance flight.
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Affiliation(s)
- Devaleena S Pradhan
- Department of Integrative Biology and Physiology, University of California, Los Angeles, USA.
- Laboratory for Neuroendocrinology, University of California, Los Angeles, USA.
- Department of Biological Sciences, Idaho State University, Pocatello, ID, 83209-8007, USA.
| | - Chunqi Ma
- Department of Psychology, University of British Columbia, Vancouver, Canada
| | - Barney A Schlinger
- Department of Integrative Biology and Physiology, University of California, Los Angeles, USA
- Laboratory for Neuroendocrinology, University of California, Los Angeles, USA
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, USA
| | - Kiran K Soma
- Department of Psychology, University of British Columbia, Vancouver, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Marilyn Ramenofsky
- Department of Neurobiology Physiology Behavior, University of California, Davis, USA
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The function of ultrasonic vocalizations during territorial defence by pair-bonded male and female California mice. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2017.11.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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York JE, Radford AN, de Vries B, Groothuis TG, Young AJ. Dominance-related seasonal song production is unrelated to circulating testosterone in a subtropical songbird. Gen Comp Endocrinol 2016; 233:43-52. [PMID: 27179883 PMCID: PMC4920672 DOI: 10.1016/j.ygcen.2016.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 04/30/2016] [Accepted: 05/10/2016] [Indexed: 02/07/2023]
Abstract
Circulating testosterone (T) is widely considered to play a key role in the production of sexual displays by male vertebrates. While numerous studies support a role for circulating T in promoting the production of song in male birds, this understanding is based primarily on evidence from seasonally breeding northern temperate species, leaving it unclear whether this mechanism generalizes to other regions of the world. Here we investigate whether variation in circulating levels of T can explain the marked within- and among-individual variation in male song performance observed in a subtropical population of the year-round territorial white-browed sparrow weaver (Plocepasser mahali mahali). Our findings reveal that both circulating T and male song production peaked at a similar time point, halfway through the population-level breeding season. However, while dominant males were more likely to sing and sang for longer than subordinate males, within-group paired comparisons revealed no dominance-related differences in circulating T. Moreover, comparisons both among and within individual dominant males revealed that song duration, syllable rate and proportion of time spent singing were all unrelated to circulating T. Together, our findings suggest that natural variation in male song production, at least in this population of white-browed sparrow weavers, is achieved principally through mechanisms other than variation in circulating T concentration. More widely, our results are in line with the view that male song production is not exclusively regulated by gonadally synthesized steroids.
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Affiliation(s)
- Jenny E York
- Centre for Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9EZ, UK; School of Biological Sciences, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.
| | - Andrew N Radford
- School of Biological Sciences, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Bonnie de Vries
- Behavioural Biology, The Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands
| | - Ton G Groothuis
- Behavioural Biology, The Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands
| | - Andrew J Young
- Centre for Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9EZ, UK
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Rendon NM, Keesom SM, Amadi C, Hurley LM, Demas GE. Vocalizations convey sex, seasonal phenotype, and aggression in a seasonal mammal. Physiol Behav 2015; 152:143-50. [PMID: 26386405 DOI: 10.1016/j.physbeh.2015.09.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/30/2015] [Accepted: 09/14/2015] [Indexed: 01/22/2023]
Abstract
Seasonal variation in social behavior is often accompanied by seasonal variation in communication. In mammals, how seasonal environmental cues influence aggressive vocalizations remains underexplored. Photoperiod is the primary cue coordinating seasonal responses in most temperate zone animals, including Siberian hamsters (Phodopus sungorus), a species that undergoes reproductive inhibition and increased aggression in winter. During same-sex aggressive encounters, hamsters emit both broadband calls (BBCs) and ultrasonic vocalizations (USVs) that indicate aggression and the vocalizer's sex, respectively; however, it is not known whether these rodents adjust specific elements of their vocal repertoire to reflect their photoperiod-induced seasonal phenotypes. To address this, we recorded vocalizations emitted during dyadic interactions between male or female pairs of hamsters housed in long or short photoperiods and measured serum testosterone levels. USV emission rate remained stable across photoperiods, but proportional use of USV subtypes varied in novel ways: 'jump' USVs were sensitive to seasonal phenotype, but not the vocalizer's sex, whereas 'plain' USVs were sensitive only to the sex of the vocalizer. BBC emission rate varied with seasonal phenotype; short-day non-reproductive hamsters produced more BBCs and demonstrated increased aggression compared with reproductive hamsters. Testosterone, however, was not related to vocalization rates. Collectively, these findings demonstrate that changes in the vocal repertoire of Siberian hamsters reflect sex, aggression, and seasonal phenotype, suggesting that both BBCs and USVs are important signals used during same-sex social encounters.
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Affiliation(s)
- Nikki M Rendon
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA.
| | - Sarah M Keesom
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| | - Chima Amadi
- Department of Animal Sciences, Cornell University, Ithaca, NY 14850, USA
| | - Laura M Hurley
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| | - Gregory E Demas
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
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Akçay Ç, Anderson RC, Nowicki S, Beecher MD, Searcy WA. Quiet threats: soft song as an aggressive signal in birds. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.03.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Desprat JL, Lengagne T, Dumet A, Desouhant E, Mondy N. Immunocompetence handicap hypothesis in tree frog: trade-off between sexual signals and immunity? Behav Ecol 2015. [DOI: 10.1093/beheco/arv057] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Keesom SM, Rendon NM, Demas GE, Hurley LM. Vocal behaviour during aggressive encounters between Siberian hamsters, Phodopus sungorus. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.01.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Soma KK, Rendon NM, Boonstra R, Albers HE, Demas GE. DHEA effects on brain and behavior: insights from comparative studies of aggression. J Steroid Biochem Mol Biol 2015; 145:261-72. [PMID: 24928552 DOI: 10.1016/j.jsbmb.2014.05.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/09/2014] [Accepted: 05/15/2014] [Indexed: 12/24/2022]
Abstract
Historically, research on the neuroendocrinology of aggression has been dominated by the paradigm that the brain receives sex steroid hormones, such as testosterone (T), from the gonads, and then these gonadal hormones modulate behaviorally relevant neural circuits. While this paradigm has been extremely useful for advancing the field, recent studies reveal important alternatives. For example, most vertebrate species are seasonal breeders, and many species show aggression outside of the breeding season, when the gonads are regressed and circulating levels of gonadal steroids are relatively low. Studies in diverse avian and mammalian species suggest that adrenal dehydroepiandrosterone (DHEA), an androgen precursor and prohormone, is important for the expression of aggression when gonadal T synthesis is low. Circulating DHEA can be converted into active sex steroids within the brain. In addition, the brain can synthesize sex steroids de novo from cholesterol, thereby uncoupling brain steroid levels from circulating steroid levels. These alternative mechanisms to provide sex steroids to specific neural circuits may have evolved to avoid the costs of high circulating T levels during the non-breeding season. Physiological indicators of season (e.g., melatonin) may allow animals to switch from one neuroendocrine mechanism to another across the year. DHEA and neurosteroids are likely to be important for the control of multiple behaviors in many species, including humans. These studies yield fundamental insights into the regulation of DHEA secretion, the mechanisms by which DHEA affects behavior, and the brain regions and neural processes that are modulated by DHEA. It is clear that the brain is an important site of DHEA synthesis and action. This article is part of a Special Issue entitled 'Essential role of DHEA'.
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Affiliation(s)
- Kiran K Soma
- Departments of Psychology and Zoology, Graduate Program in Neuroscience, and the Brain Research Centre, University of British Columbia, Vancouver, BC, Canada V6T 1Z4.
| | - Nikki M Rendon
- Department of Biology, Program in Neuroscience, and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - Rudy Boonstra
- Centre for Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada M1C 1A4
| | - H Elliott Albers
- Neuroscience Institute, and Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30303, USA
| | - Gregory E Demas
- Department of Biology, Program in Neuroscience, and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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Wilson DR, Bitton PP, Podos J, Mennill DJ. Uneven Sampling and the Analysis of Vocal Performance Constraints. Am Nat 2014; 183:214-28. [DOI: 10.1086/674379] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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