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1.
Proc Biol Sci ; 291(2029): 20241060, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39196274

RESUMEN

Sexual signals such as colour ornamentation and birdsong evolve independently of each other in some clades, and in others they evolve positively or negatively correlated. We rarely know why correlated evolution does or does not occur. Here, we show positively correlated evolution between plumage colour and song motor performance among canaries, goldfinches and allies, associated with species differences in body size. When controlling for body size, the pattern of correlated evolution between song performance and colour disappeared. Syllable diversity was not as strongly associated with size, and did not evolve in a correlated manner with colour. We argue that correlated evolution between song and colour was mediated by large size limiting song motor performance, likely due to constraints on the speed of moving heavier bills, and by larger species having less saturated plumage colour, possibly due to life-history traits of larger birds (e.g. longevity, stable pairs) contributing to weaker sexual selection. Results are consistent with the hypothesis that correlated evolution between sexual signals is influenced by how, in a clade, selective pressures and constraints affecting each type of signal happen to be co-distributed across species. Such contingency helps explain the diversity in clade-specific patterns of correlated evolution between sexual signals.


Asunto(s)
Evolución Biológica , Tamaño Corporal , Pinzones , Vocalización Animal , Animales , Pinzones/fisiología , Pinzones/anatomía & histología , Canarios/fisiología , Canarios/anatomía & histología , Pigmentación , Plumas/anatomía & histología , Plumas/fisiología , Color , Masculino , Femenino , Pájaros Cantores/fisiología
2.
Proc Biol Sci ; 290(2000): 20230206, 2023 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-37312555

RESUMEN

Bullying consists of preferentially attacking individuals lowest in the dominance hierarchy, and its functions are unclear because the most subordinate individuals do not pose social challenges to the aggressor. Instead, conflict is expected mostly between individuals of similar dominance rank or socially distant (i.e. weakly associated), among whom dominance relationships may not be well established. A possible function of bullying is that it may be used as a low-risk strategy of showing-off dominance to relevant third parties. To study this hypothesis, we monitored aggressions during feeding, the composition of audiences, dominance hierarchy and social network of common waxbills (Estrilda astrild) in an open-air mesocosm, and tested (i) whether their aggressions show a pattern of bullying, and (ii) whether audience effects influence aggressiveness. Waxbills showed bullying, most often attacking the lowest ranking individuals rather than socially distant individuals or those of similar dominance rank, and aggressions increased when the audience included socially distant individuals, indicating a signalling function of bullying. Showing-off dominance in the presence of socially distant individuals may be a strategy to manage dominance hierarchies, avoiding direct fights with potentially dangerous opponents in the audience. We suggest that bullying is a safe manner of managing dominance hierarchies, by signalling dominance status to potential opponents.


Asunto(s)
Publicidad , Acoso Escolar , Humanos , Agresión , Transducción de Señal , Predominio Social
3.
Physiol Behav ; 267: 114226, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37150430

RESUMEN

The oxytocin family of neuropeptides is implicated in the regulation of sociality across vertebrates. Non-mammalian homologs of oxytocin, such as isotocin in fish and mesotocin in amphibians, reptiles and birds, all play crucial roles modulating social and reproductive behavior. In this study, we exogenously manipulated the mesotocinergic system in a highly social bird, the common waxbill Estrild astrild, and tested the effects on affiliative and aggressive behavior by performing tests of competition over food. Birds treated with mesotocin decreased almost all the behaviors we studied (movement, feeding, allopreening), while birds treated with an oxytocin antagonist showed a reduction only in social behaviors (aggressions and allopreening). We also found two sex-specific effects: mesotocin reduced allopreening more in males than females, and the oxytocin antagonist reduced aggressiveness only in females. Our results suggest sex-specific effects in the modulation of affiliative and aggressive behaviors via mesotocinergic pathways.


Asunto(s)
Oxitocina , Conducta Social , Animales , Masculino , Femenino , Oxitocina/farmacología , Oxitocina/metabolismo , Agresión , Peces , Aves
4.
Proc Biol Sci ; 289(1984): 20221677, 2022 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-36476006

RESUMEN

Carotenoid-based colour signals can be costly to produce and maintain, and trade-offs between signalling and other fitness traits are expected. In mutually ornamented species, trade-offs with reproduction may be stronger for females than males, because females often dedicate more resources to offspring production, which may lead to plastic investment in colour signals and plastic sexual dichromatism. Oestradiol is a candidate mediator of this trade-off because it regulates reproductive physiology and may also influence the expression of coloration. We tested this hypothesis by giving female common waxbills (Estrilda astrild) either oestradiol (17ß-oestradiol) or empty implants during the early breeding season and measured spectral reflectance of carotenoid-based bill coloration weekly for two months. Using a model of avian vision, we found that bill colour in oestradiol-implanted females became less saturated, less red in hue and brighter, compared with control females and with unimplanted males. This resulted in a change in bill sexual dichromatism from imperceptible to perceptible. Results support the hypothesis that female reproductive physiology influences investment in coloration through changes in oestradiol and show a form of female-driven plastic sexual dichromatism. Greater sensitivity of female colour to physiological and/or environmental conditions helps explain why differences in sexual dichromatism among species differing in ecology often evolve owing to changes in female rather than male phenotype.


Asunto(s)
Ecología , Estradiol , Femenino , Masculino , Animales
5.
Am Nat ; 200(6): E237-E247, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36409985

RESUMEN

AbstractSexual ornamentation is often assumed to be costly, allowing honest signaling of individual quality, and carotenoid-based colors have been proposed to bear significant costs. If carotenoid-based colors are costly to produce, sexually selected signals should use more concentrated carotenoid pigments and have more saturated color than nonsexual signals, where honesty-guaranteeing costs are not required. We tested this prediction comparing carotenoid-based colors across canaries, goldfinches, and allies because many of these species use yellow plumage as sexual ornamentation but also have yellow rumps that appear to be nonsexual flash marks. Only in the breast, but not the rump, was there an asymmetric codistribution of male and female color saturation, with males similarly or more saturated than females, indicating evolution of breast color by sexual selection. Yellow was not consistently more saturated in the breast than in the rump, and the codistribution of rump and breast color saturation indicated that saturated rumps can persist irrespective of breast color. This challenges the assumption that carotenoid-based colors bear significant costs. The use of carotenoid coloration as sexual signals in this clade may instead be due to social costs, cost-free index mechanisms for signaling quality, and/or socially monogamous species evolving low-cost signals to mostly discriminate against the lowest-quality mates.


Asunto(s)
Brassicaceae , Pinzones , Pigmentación , Animales , Femenino , Masculino , Carotenoides
6.
J Evol Biol ; 35(3): 439-450, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35147264

RESUMEN

Morphology, habitat and various selective pressures (e.g. social and sexual selection) can influence the evolution of acoustic signals, but the relative importance of their effects is not well understood. The order Psittaciformes (parrots, sensu lato) is a large clade of very vocal and often gregarious species for which large-scale comparative studies of vocalizations are lacking. We measured acoustic traits (duration, sound frequency, frequency bandwidth and sound entropy) of the predominant call type for >200 parrot species to test: (1) for associations with body size; (2) the acoustic adaptation hypothesis (AAH) (predicting differences between forest and open-habitat species); (3) the social complexity hypothesis (predicting more complex calls in gregarious species) and (4) influences of sexual selection (predicting correlated evolution with colour ornamentation). Larger species had on average longer calls, lower sound frequency and wider frequency bandwidth. These associations with body size are all predicted by physical principles of sound production. We found no evidence for the acoustic adaptation and social complexity hypotheses, but perhaps social complexity is associated with vocal traits not studied here, such as call repertoire sizes. More sexually dichromatic species had on average simpler calls (shorter, with lower entropy and narrower frequency bandwidth) indicating an influence of sexual selection, namely an evolutionary negative correlation between colour ornamentation and elaborate acoustic signals, as predicted by the transference hypothesis. Our study is the first large-scale attempt at understanding acoustic diversity across the Psittaciformes, and indicates that body size and sexual selection influenced the evolution of species differences in vocal signals.


Asunto(s)
Loros , Selección Sexual , Acústica , Animales , Tamaño Corporal , Vocalización Animal
7.
J Exp Biol ; 225(6)2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35202471

RESUMEN

The dopaminergic (DAergic) system has well-known influences on behavioral and cognitive functions. Previous work with common waxbills (Estrilda astrild) reported context-specific DAergic effects that could have been due to social environment. Manipulating the dopamine D2-like receptor family (D2R) pathways had opposing effects on behavior depending on whether waxbills were tested alone or in a small cage with a mirror as a social stimulus. As waxbills are highly gregarious, it was hypothesized that being alone or perceiving that they have a companion might explain this context dependence. To test context-dependent DAergic effects, we compared behavioral effects of D2R manipulation in waxbills in the same familiar environment, but either alone or with a familiar, same-sex companion. We found that D2R agonism decreased movement and feeding, similar to previous results when testing waxbills alone. However, contrary to the hypothesis of dependence on social context, we found that the behavioral effects of the D2R agonist were unchanged when waxbills were tested with a companion. The context dependence reported earlier might thus be due to other factors, such as the stress of being in a novel environment (small cage) or with an unfamiliar social stimulus (mirror image). In tests with a companion, we also found a sex-specific social effect of D2R manipulation: D2R blocking tended to decrease aggression in males but to increase it in females. Together with past work, our results suggest that DAergic effects on behavior involve different types of context or sex dependence.


Asunto(s)
Aves , Dopamina , Agresión , Animales , Cognición , Dopamina/farmacología , Dopaminérgicos , Femenino , Masculino
8.
Sci Rep ; 11(1): 14970, 2021 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-34294752

RESUMEN

Sex differences in ornamentation are common and, in species with conventional sex roles, are generally thought of as stable, due to stronger sexual selection on males. Yet, especially in gregarious species, ornaments can also have non-sexual social functions, raising the possibility that observed sex differences in ornamentation are plastic. For example, females may invest in costly ornamentation more plastically, to protect body and reproductive ability in more adverse ecological conditions. We tested this hypothesis with experimental work on the mutually-ornamented common waxbill (Estrilda astrild), supplementing their diets either with pigmentary (lutein, a carotenoid) or non-pigmentary (vitamin E) antioxidants, or alleviating winter cold temperature. We found that both lutein and vitamin E supplementation increased red bill colour saturation in females, reaching the same mean saturation as males, which supports the hypothesis that female bill colour is more sensitive to environmental or physiological conditions. The effect of vitamin E, a non-pigment antioxidant, suggests that carotenoids were released from their antioxidant functions. Alleviating winter cold did not increase bill colour saturation in either sex, but increased the stability of female bill colour over time, suggesting that female investment in bill colour is sensitive to cold-mediated stress. Together, results show that waxbill bill sexual dichromatism is not stable. Instead, sexual dichromatism can be modulated, and even disappear completely, due to ecology-mediated plastic adjustments in female bill colour.


Asunto(s)
Alimentación Animal/análisis , Pigmentación/fisiología , Pájaros Cantores/fisiología , Adaptación Fisiológica , Animales , Color , Fenómenos Ecológicos y Ambientales , Femenino , Masculino , Caracteres Sexuales
9.
Rev Bras Ginecol Obstet ; 43(5): 395-402, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34077990

RESUMEN

In a healthy athlete, the caloric intake is sufficient for sports energy needs and body physiological functions, allowing a balance between energy availability, bone metabolism, and menstrual cycle. On the other hand, an imbalance caused by low energy availability due to a restrictive diet, eating disorders or long periods of energy expenditure leads to multisystemic deregulation favoring the essential functions of the body. This phenomenon, described as the female athlete triad, occurs in a considerable percentage of high-performance athletes, with harmful consequences for their future. The present review was carried out based on a critical analysis of the most recent publications available and aims to provide a global perception of the topic relative energy deficit in sport (RED-S). The objective is to promote the acquisition of more consolidated knowledge on an undervalued theme, enabling the acquisition of preventive strategies, early diagnosis and/or appropriate treatment.


Em uma atleta saudável, o aporte calórico é suficiente para a necessidade energética esportiva e para as funções fisiológicas corporais, permitindo um equilíbrio entre disponibilidade energética (DE), metabolismo ósseo e função menstrual. Por outro lado, um desequilíbrio devido à baixa disponibilidade energética (BDE) por dieta restritiva, perturbações alimentares ou grandes períodos de gasto energético conduz a uma desregulação multissistêmica priorizando as funções essenciais do corpo. Este fenômeno, descrito inicialmente como tríade da mulher atleta e, atualmente, como défice energético relativo no esporte (RED-S, na sigla em inglês) tem como pilares a BDE, disfunção menstrual e alterações na densidade mineral óssea (DMO), estando presente em uma percentagem considerável de atletas de alta competição, com consequências nefastas para o seu futuro a curto, médio e longo prazo. A presente revisão foi realizada a partir da análise crítica das publicações mais recentes disponíveis e pretende proporcionar uma percepção global do tema RED-S. O objetivo é promover a aquisição de um conhecimento mais consolidado sobre uma temática subvalorizada, possibilitando a aquisição de estratégias preventivas, diagnóstico precoce e/ou tratamento adequado.


Asunto(s)
Rendimiento Atlético , Ingestión de Energía/fisiología , Síndrome de la Tríada de la Atleta Femenina , Deficiencia Relativa de Energía en el Deporte , Amenorrea , Atletas , Metabolismo Energético/fisiología , Trastornos de Alimentación y de la Ingestión de Alimentos/complicaciones , Femenino , Síndrome de la Tríada de la Atleta Femenina/diagnóstico , Síndrome de la Tríada de la Atleta Femenina/prevención & control , Humanos , Trastornos de la Menstruación/complicaciones
10.
Sci Rep ; 11(1): 11600, 2021 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-34078943

RESUMEN

Sexual signals are archetypes of contingent evolution: hyper-diverse across species, often evolving fast and in unpredictable directions. It is unclear to which extent their evolutionary unpredictability weakens deterministic evolution, or takes place bounded by deterministic patterns of trait evolution. We compared the evolution of sound frequency in sexual signals (advertisement songs) and non-sexual social signals (calls) across > 500 genera of the crown songbird families. Contrary to the acoustic adaptation hypothesis, we found no evidence that forest species used lower sound frequencies in songs or calls. Consistent with contingent evolution in song, we found lower phylogenetic signal for the sound frequency of songs than calls, which suggests faster and less predictable evolution, and found unpredictable direction of evolution in lineages with longer songs, which presumably experience stronger sexual selection on song. Nonetheless, the most important deterministic pattern of sound frequency evolution-its negative association with body size-was stronger in songs than calls. This can be explained by songs being longer-range signals than most calls, and thus using sound frequencies that animals of a given size produce best at high amplitude. Results indicate that sexual selection can increase aspects of evolutionary contingency while strengthening, rather than weakening, deterministic patterns of evolution.


Asunto(s)
Adaptación Fisiológica , Evolución Biológica , Pájaros Cantores/fisiología , Vocalización Animal/fisiología , Acústica/instrumentación , Animales , Tamaño Corporal , Femenino , Masculino , Filogenia , Pájaros Cantores/clasificación , Sonido
11.
Rev. bras. ginecol. obstet ; 43(5): 395-402, May 2021. graf
Artículo en Inglés | LILACS | ID: biblio-1288555

RESUMEN

Abstract In a healthy athlete, the caloric intake is sufficient for sports energy needs and body physiological functions, allowing a balance between energy availability, bone metabolism, andmenstrual cycle.Onthe other hand, an imbalance causedby low energy availability dueto a restrictive diet, eating disorders or long periods of energy expenditure leads to multisystemic deregulation favoring the essential functions of the body. This phenomenon, described as the female athlete triad, occurs in a considerable percentage of high-performance athletes, with harmful consequences for their future. The present review was carried out based on a critical analysis of themost recent publications available and aims to provide a global perception of the topic relative energy deficit in sport (RED-S). The objective is to promote theacquisition ofmore consolidated knowledgeon an undervaluedtheme, enabling the acquisition of preventive strategies, early diagnosis and/or appropriate treatment.


Resumo Emumaatleta saudável, oaporte calórico é suficientepara anecessidade energética esportiva e para as funções fisiológicas corporais, permitindo um equilíbrio entre disponibilidade energética (DE), metabolismo ósseo e função menstrual. Por outro lado, um desequilíbrio devido à baixa disponibilidade energética (BDE) por dieta restritiva, perturbações alimentares ou grandes períodos de gasto energético conduz a uma desregulação multissistêmica priorizando as funções essenciais do corpo. Este fenômeno, descrito inicialmente como tríade da mulher atleta e, atualmente, comodéfice energético relativo no esporte (RED-S, nasigla eminglês) tem como pilares a BDE, disfunção menstrual e alterações na densidade mineral óssea (DMO), estando presente em uma percentagem considerável de atletas de alta competição, com consequências nefastas para o seu futuro a curto, médio e longo prazo. A presente revisão foi realizada a partir da análise crítica das publicações mais recentes disponíveis e pretende proporcionar uma percepção global do tema RED-S. O objetivo é promover a aquisição de um conhecimento mais consolidado sobre uma temática subvalorizada, possibilitando a aquisição de estratégias preventivas, diagnóstico precoce e/ou tratamento adequado.


Asunto(s)
Humanos , Femenino , Ingestión de Energía/fisiología , Síndrome de la Tríada de la Atleta Femenina/diagnóstico , Síndrome de la Tríada de la Atleta Femenina/prevención & control , Rendimiento Atlético , Deficiencia Relativa de Energía en el Deporte , Trastornos de Alimentación y de la Ingestión de Alimentos/complicaciones , Metabolismo Energético/fisiología , Atletas , Amenorrea , Trastornos de la Menstruación/complicaciones
12.
Am Nat ; 197(5): 607-614, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33908826

RESUMEN

AbstractTheory predicts that allometric constraints on sound production should be stronger for the lower frequencies of vocalizations than for the higher frequencies, which could originate from an allometry for sound frequency bandwidth. Using song recordings of approximately 1,000 passerine species (from >75% passerine genera), we show a significantly steeper allometry for the lower song frequencies than for the higher song frequencies, resulting in a positive allometry of frequency bandwidth: larger species can use wider bandwidths than smaller species. The bandwidth allometry exists in songbirds (oscines) but not in nonoscine passerines, indicating that it emerges from a combination of constraints to sound frequency production or transmission and the evolved behavior of oscines: unlike the narrow bandwidths of most nonoscine songs, the learned songs of oscines often use wide bandwidths that can be limited by both lower and upper constraints to sound frequency. This bandwidth allometry has implications for several research topics in acoustic communication.


Asunto(s)
Pájaros Cantores , Vocalización Animal , Animales , Aprendizaje , Pájaros Cantores/fisiología , Sonido , Vocalización Animal/fisiología
13.
Rev Port Cardiol (Engl Ed) ; 40(1): 25-30, 2021 Jan.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-33303300

RESUMEN

INTRODUCTION: Coronary artery calcium (CAC) scoring is used for both cardiovascular risk reclassification and as a gatekeeper for coronary computed tomography angiography (CCTA). The aims of this study were to assess to what extent CAC score results can reclassify the cardiovascular risk of patients without obstructive coronary artery disease (CAD) on CCTA, and to measure the proportion of these patients whose primary prevention medication is changed after the exam. METHODS: In a retrospective analysis of a multicenter registry of individuals who underwent CCTA for suspected CAD during a two-year period, the Systematic COronary Risk Evaluation (SCORE) and Multi-Ethnic Study of Atherosclerosis (MESA) risk scores were calculated for each individual. In a subset of 184 patients, we also assessed the prescription of statins and antiplatelet agents before and after the test. RESULTS: A total of 467 patients (248 women, mean age 60±9.10 years) were included. Median CAC score was 0 (interquartile range 0-40). Overall, 249 patients (53%) and 159 (34%) were classified as being of moderate/intermediate risk according to the SCORE and MESA risk scores, respectively. Among these, 29 (12%) and 30 (19%) patients had CAC score >100 AU, making them eligible for statin therapy. The inclusion of CAC scoring in the MESA score resulted in the reclassification of 215 patients (46%). The proportion of patients who were prescribed statins or antiplatelet agents did not change significantly after the test. CONCLUSION: CAC scoring can reclassify cardiovascular risk in a significant proportion of patients undergoing CCTA. Despite this, little change was seen in the prescription of statins and antiplatelet agents.


Asunto(s)
Calcio , Enfermedades Cardiovasculares , Anciano , Angiografía por Tomografía Computarizada , Angiografía Coronaria , Vasos Coronarios/diagnóstico por imagen , Femenino , Factores de Riesgo de Enfermedad Cardiaca , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo
14.
Anim Behav ; 170: 33-41, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33208979

RESUMEN

Environmental changes caused by urbanization and noise pollution can have profound effects on acoustic communication. Many organisms use higher sound frequencies in urban environments with low-frequency noise, but the developmental and evolutionary mechanisms underlying these shifts are generally unknown. We used a common garden experiment to ask whether changes in minimum song frequency observed 30 years after a songbird colonized an urban environment are a consequence of behavioural flexibility. We captured male juvenile dark-eyed juncos, Junco hyemalis thurberi, from two populations (urban and mountain) soon after they reached independence (aged 25-40 days), raised them in identical indoor aviaries and studied their songs at an age of 3 years. We found that the large population difference in minimum frequency observed in the field persisted undiminished in the common garden despite the absence of noise. We also found some song sharing between the common garden and natal field populations, indicating that early song memorization before capture could contribute to the persistent song differences in adulthood. These results are the first to show that frequency shifts in urban birdsong are maintained in the absence of noise by genetic evolution and/or early life experiences.

15.
Behav Processes ; 181: 104246, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32946953

RESUMEN

While vivid colours in sexual signals can provide information on individual quality, vivid colours in interspecific signals have been interpreted mostly as indicating species identity and maximizing signal detection. Here we investigate if colour differences in an interspecific signal could also indicate relevant aspects of individual quality because, similarly to sexual signalling, in interspecific communication it could sometimes be advantageous to assess individual quality. For example when interacting with cleaner species, clients should benefit from assessing which individual cleaners provide better service. Since oxidative stress commonly influence condition-dependent colour signals, we oxidized the diet of cleaner wrasses (Labroides dimidiatus) in laboratory conditions to test if this affects their vivid blue skin colour and the quality of their cleaning service. Compared to controls, experimental cleaners decreased blue colour saturation after the oxidized diet treatment, decreased the quality of their cleaning service by performing less tactile stimulation and, although clients in the laboratory were de-parasitized, also tended to decrease the touching the client with the mouth. We used visual modelling, based on the spectral sensitivity of vision in various client species, to show that some client species can perceive these changes in cleaner blue colour saturation, while other client species not. We suggest that, similarly to sexual signals, some vivid colours used in interspecific communication may convey information on aspects of individual quality that are relevant to heterospecifics.


Asunto(s)
Perciformes , Animales , Color , Tacto
16.
Evolution ; 74(6): 1170-1185, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32352570

RESUMEN

The diversity and the motor performance of birdsongs can both be sexually selected. In wood warblers, most species with high motor performance sing a greater proportion of trills, presumably to advertise performance, and thus have lower syllable diversity. We tested if this trade-off between motor performance and syllable diversity extends to canaries, goldfinches and allies, a clade with much longer and more varied songs. We assembled a molecular phylogeny and inferred song motor performance based on the speed of frequency modulation either in trills or in within-song intervals. The two metrics of performance were positively, but only mildly, related across species. While performance evaluated in intervals had high phylogenetic signal, performance evaluated in trills changed independently of phylogeny and was constrained by body size. Species in densely vegetated habitats sang fewer trills, but did not differ in motor performance. Contrary to wood warblers, song motor performance did not predict the proportion of trilled syllables nor within-song syllable diversity, perhaps because large differences in the song duration of canaries, goldfinches and allies prevent trills from severely compromising syllable diversity. Opposed results in wood warblers and in these finches indicate the existence of clade-specific trade-offs in the evolution of birdsong.


Asunto(s)
Evolución Biológica , Canarios/genética , Desempeño Psicomotor , Vocalización Animal , Animales
17.
Proc Biol Sci ; 287(1926): 20200525, 2020 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-32345155

RESUMEN

Environmental instability (i.e. environments changing often) can select fixed phenotypes because of the lag time of plastically adapting to environmental changes, known as the lag-time constraint. Because behaviour can change rapidly (e.g. switching between foraging strategies), the lag-time constraint is not considered important for behavioural plasticity. Instead, it is often argued that responsive behaviour (i.e. behaviour that changes according to the environment) evolves to cope with unstable environments. But proficiently performing certain behaviours may require time for learning, for practising or, in social animals, for the group to adjust to one's behaviour. Conversely, not using certain behaviours for a period of time can reduce their level of performance. Here, using individual-based evolutionary simulations, we show that environmental instability selects for fixed behaviour when the ratio between the rates of increase and reduction in behavioural performance is below a certain threshold; only above this threshold does responsive behaviour evolve in unstable environments. Thus, the lag-time constraint can apply to behaviours that attain high performance either slowly or rapidly, depending on the relative rate with which their performance decreases when not used. We discuss these results in the context of the evolution of reduced behavioural plasticity, as seen in fixed personality differences.


Asunto(s)
Adaptación Psicológica , Conducta Animal , Animales , Fenotipo
18.
J Exp Biol ; 223(Pt 3)2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-31953366

RESUMEN

There is increasing interest in the genetic and physiological bases of behavioural differences among individuals, namely animal personality. One particular dopamine (DA) receptor gene (the dopamine receptor D4 gene) has been used as candidate gene to explain personality differences, but with mixed results. Here, we used an alternative approach, exogenously manipulating the dopaminergic system and testing for effects on personality assays in a social bird species, the common waxbill (Estrilda astrild). We treated birds with agonists and antagonists for DA receptors of both D1 and D2 receptor pathways (the latter includes the D4 receptor) and found that short-term manipulation of DA signalling had an immediate effect on personality-related behaviours. In an assay of social responses (mirror test), manipulation of D2 receptor pathways reduced time spent looking at the social stimulus (mirror image). Blocking D2 receptors reduced motor activity in this social assay, while treatment with a D2 receptor agonist augmented activity in this social assay but reduced activity in a non-social behavioural assay. Also, in the non-social assay, treatment with the D1 receptor antagonist markedly increased time spent at the feeder. These results show distinct and context-specific effects of the dopaminergic pathways on waxbill personality traits. Our results also suggest that experimental manipulation of DA signalling can disrupt a behavioural correlation (more active individuals being less attentive to mirror image) that is habitually observed as part of a behavioural syndrome in waxbills. We discuss our results in the context of animal personality, and the role of the DA system in reward and social behaviour.


Asunto(s)
Agonistas de Dopamina/farmacología , Antagonistas de Dopamina/farmacología , Dopamina/metabolismo , Personalidad , Pájaros Cantores/fisiología , Animales , Proteínas Aviares/genética , Proteínas Aviares/metabolismo , Femenino , Masculino , Receptores de Dopamina D1/genética , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo
19.
Clin Rev Allergy Immunol ; 59(3): 287-294, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31444781

RESUMEN

Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease associated with major obstetrical complications such as gestational loss, preterm delivery, fetal growth restriction (FGR) and preeclampsia. Published literature is not consensual regarding the main risk factors for each of these outcomes. Our goal with this study was to determine the most important predictors for each of the main adverse pregnancy outcomes in this population. We conducted a retrospective cohort study of unifetal pregnancies of women with the diagnosis of SLE followed in our unit between January 1994 and December 2016. We excluded elective terminations of pregnancy and cases lost to follow-up and we analyzed 157 pregnancies (128 women). Multiple logistic regression models for the outcomes gestational loss, preterm delivery, fetal growth restriction, and preeclampsia were built. Two-sided p-values of < 0.05 were used to determine statistical significance, and two-sided confidence intervals of 95% are reported. In our cohort, the main risk factors for gestational loss were maternal age and the presence of antiphospholipid antibodies. Lupic nephritis was predictive of a preterm delivery and preeclampsia. Renal involvement and lupus flares during pregnancy were risk factors for FGR. Overall, the main risk factor for an adverse pregnancy outcome were lupus flares during pregnancy. Despite optimal pregnancy monitoring, women with SLE are still at risk for adverse pregnancy outcomes. Risk stratification for each of these outcomes is crucial for an effective counselling and tailored monitoring.


Asunto(s)
Lupus Eritematoso Sistémico/epidemiología , Complicaciones del Embarazo/epidemiología , Resultado del Embarazo/epidemiología , Adulto , Anticuerpos Antifosfolípidos/sangre , Anticuerpos Antifosfolípidos/inmunología , Autoinmunidad , Biomarcadores , Ensayo de Inmunoadsorción Enzimática , Femenino , Retardo del Crecimiento Fetal/diagnóstico , Retardo del Crecimiento Fetal/etiología , Humanos , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/inmunología , Persona de Mediana Edad , Preeclampsia/diagnóstico , Preeclampsia/etiología , Embarazo , Complicaciones del Embarazo/diagnóstico , Estudios Retrospectivos , Adulto Joven
20.
Sci Rep ; 9(1): 19942, 2019 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-31882777

RESUMEN

Coronary CT angiography (CTA) is currently considered a reliable method to exclude obstructive coronary artery disease (CAD) before valvular heart surgery in patients with low pretest probability. However, its role in excluding obstructive CAD before transcatheter aortic valve implantation (TAVI) is less well established. Single-center retrospective study where patients with severe symptomatic aortic stenosis underwent both CTA and invasive coronary angiography (ICA) as part of TAVI planning. CTA exams were conducted on a 64-slice dual source scanner, with a median interval of 45 days to ICA (IQR 25-75 [13-82]). In both tests, obstructive CAD was defined as a ≥50% stenosis in an epicardial vessel ≥2 mm diameter. Per-patient, per-vessel and per-proximal segment analyses were conducted, excluding and including non-evaluable segments. The study included 200 patients (120 women, mean age 83 ± 6 years). The prevalence of obstructive CAD on ICA was 35.5% (n = 71). On a per-patient analysis (assuming non-evaluable segments as stenotic), CTA showed sensitivity of 100% (95% CI, 95-100%), specificity of 42% (95% CI, 33-51%), and positive and negative predictive values of 48% (95% CI, 44-51%) and 100% (95% CI, 92-100%), respectively. CTA was able to exclude obstructive CAD in 54 patients (27%), in whom ICA could have been safely withheld. Despite the high rate of inconclusive tests, pre-procedural CTA is able to safely exclude obstructive CAD in a significant proportion of patients undergoing TAVI, possibly avoiding the need for ICA in roughly one quarter of the cases.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Anciano , Anciano de 80 o más Años , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico , Estenosis Coronaria/fisiopatología , Femenino , Humanos , Masculino , Tomografía Computarizada Multidetector/métodos , Imagen de Perfusión Miocárdica/métodos , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Sensibilidad y Especificidad
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