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1.
Am Nat ; 203(1): 92-108, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38207138

RESUMO

AbstractIn chorusing species, conspecific interference exerts strong selection on signal form and timing to maximize conspicuousness and attractiveness within the signaling milieu. We investigated how túngara frog calling strategies were influenced by varied social environments and male phenotypes and how calling interactions influenced female preferences. When chorusing, túngara frog calls consist of a whine typically followed by one to three chucks. In experimental choruses we saw that as chorus size increased, calls increasingly had their chucks overlapped by the high-amplitude beginning section of other callers' whines. Playback experiments revealed that such overlap reduced the attractiveness of calls to females but that appending additional chucks mitigated this effect. Thus, more elaborate calls were preferred when calls suffered overlap, although they were not preferred when overlap was absent. In response to increasing risk of overlap in larger choruses, males increased call elaboration. However, males overwhelmingly produced two-chuck calls in even the largest choruses, despite our results suggesting that additional chucks would more effectively safeguard calls. Furthermore, aspects of male phenotypes predicted to limit call elaboration had negligible or uncertain effects, suggesting that other constraints are operating. These results highlight how complex interrelations among signal form, signaling interactions, and the social environment shape the evolution of communication in social species.


Assuntos
Comportamento Sexual Animal , Vocalização Animal , Animais , Feminino , Masculino , Vocalização Animal/fisiologia , Comportamento Sexual Animal/fisiologia , Anuros/fisiologia
2.
N Engl J Med ; 385(2): 179-186, 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34161052

RESUMO

Viral variants of concern may emerge with dangerous resistance to the immunity generated by the current vaccines to prevent coronavirus disease 2019 (Covid-19). Moreover, if some variants of concern have increased transmissibility or virulence, the importance of efficient public health measures and vaccination programs will increase. The global response must be both timely and science based.


Assuntos
Vacinas contra COVID-19 , COVID-19/prevenção & controle , SARS-CoV-2 , COVID-19/transmissão , Vacinas contra COVID-19/imunologia , Humanos , Imunogenicidade da Vacina , Mutação , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/genética , Virulência
3.
Clin Exp Rheumatol ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38634375

RESUMO

OBJECTIVES: No article on serum lipids in ankylosing spondylitis (AS) and control subjects has been reported from USA. The primary aim of this study was to determine if any difference occurred in serum lipid levels in AS and control rheumatic disorders in two time periods, 1978-98 and 2000-10. The secondary aim was to investigate variables associated with lipid levels and if a difference was found between AS and control disorders. METHODS: The AS patients were compared to non-inflammatory rheumatic disorders (NIRDs) in 1978-98 and 2000-10 surveys and to rheumatoid arthritis (RA) in the 2000-10 survey. Patients were matched within 5 years of age, sex, and clinic or hospital source. RESULTS: In the 1978-98 survey, entry mean (SEM) serum cholesterol level [mg/dL] was highly (p<0.001) significantly lower in 69 AS [179.0 (4.8)] than 69 matched NIRD controls [208.0 (5.6)]. In 29 pairs of AS and NIRD subjects having manual labour occupations, mean (SEM) cholesterol level was additionally lower in AS [156.7 (5.9)] and higher in 29 NIRD controls [213.3 (8.6)] (p<0.001). In manual labour workers, mean (SEM) serum triglyceride was significantly lower (p=0.004) in 15 AS [110.3 (14.1)] than 14 NIRD controls [185.2 (19.3)]. In the 2000-10 survey, no lipid difference was found between AS vs. NIRD control patients. CONCLUSIONS: In the 1978-98 survey, AS had significantly lower mean serum cholesterol and triglyceride levels than NIRD control patients. Associated manual labour occupations may have significantly contributed to results, possibly related to increased energy expenditures from physical activity in the pre-2000 era.

4.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33593899

RESUMO

One hundred fifty years ago Darwin published The Descent of Man, and Selection in Relation to Sex, in which he presented his theory of sexual selection with its emphasis on sexual beauty. However, it was not until 50 y ago that there was a renewed interest in Darwin's theory in general, and specifically the potency of mate choice. Darwin suggested that in many cases female preferences for elaborately ornamented males derived from a female's taste for the beautiful, the notion that females were attracted to sexual beauty for its own sake. Initially, female mate choice attracted the interest of behavioral ecologists focusing on the fitness advantages accrued through mate choice. Subsequent studies focused on sensory ecology and signal design, often showing how sensory end organs influenced the types of traits females found attractive. Eventually, investigations of neural circuits, neurogenetics, and neurochemistry uncovered a more complete scaffolding underlying sexual attraction. More recently, research inspired by human studies in psychophysics, behavioral economics, and neuroaesthetics have provided some notion of its higher-order mechanisms. In this paper, I review progress in our understanding of Darwin's conjecture of "a taste for the beautiful" by considering research from these diverse fields that have conspired to provide unparalleled insight into the chooser's mate choices.


Assuntos
Evolução Biológica , Encéfalo/fisiologia , Aptidão Genética , Preferência de Acasalamento Animal/fisiologia , Seleção Genética , Seleção Sexual , Animais , Corte , Feminino , Masculino , Fenótipo
5.
Clin Sci (Lond) ; 137(7): 537-542, 2023 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-37051741

RESUMO

Clinical Science was originally established as the journal Heart in 1909 by Sir Thomas Lewis and Sir James Mackenzie. Heart was an influential journal publishing cardiovascular research and was renamed Clinical Science in 1933 to attract broader research interests. Nevertheless, cardiovascular research contributions remain a foundational part of the journal to this day. This editorial provides historical perspective on the journal's cardiovascular origins and includes data related to cardiovascular publications from the past decade. Clinical Science is committed to publishing leading cardiovascular research from the field and looks forward to receiving your submission.


Assuntos
Pesquisa Biomédica , Sistema Cardiovascular , Publicações Periódicas como Assunto , Editoração , Editoração/história
6.
Clin Sci (Lond) ; 137(10): 843-846, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37255249

RESUMO

Acute kidney injury (AKI) remains a significant clinical problem with a high mortality rate. Thus, the need for early recognition and treatment of AKI is an important goal. Clinical Science has a history of publishing high impact work across a breadth of scientific disciplines to improve understanding of disease mechanisms, including nephrology. This commentary spotlights a paper from more recent history that is highly cited. The work focuses on the mechanistic role of circular RNA in the pathobiology of AKI using approaches that include both in vivo experimental models and human cell culture experiments to delineate a potentially novel cellular pathway.


Assuntos
Injúria Renal Aguda , Nefrologia , Humanos , RNA Circular/genética , Injúria Renal Aguda/genética
7.
J Arthroplasty ; 38(10): 1998-2003.e1, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-35271974

RESUMO

BACKGROUND: The surgical management of complications after total hip arthroplasty (THA) necessitates accurate identification of the femoral implant manufacturer and model. Automated image processing using deep learning has been previously developed and internally validated; however, external validation is necessary prior to responsible application of artificial intelligence (AI)-based technologies. METHODS: We trained, validated, and externally tested a deep learning system to classify femoral-sided THA implants as one of the 8 models from 2 manufacturers derived from 2,954 original, deidentified, retrospectively collected anteroposterior plain radiographs across 3 academic referral centers and 13 surgeons. From these radiographs, 2,117 were used for training, 249 for validation, and 588 for external testing. Augmentation was applied to the training set (n = 2,117,000) to increase model robustness. Performance was evaluated by area under the receiver operating characteristic curve, sensitivity, specificity, and accuracy. Implant identification processing speed was calculated. RESULTS: The training and testing sets were drawn from statistically different populations of implants (P < .001). After 1,000 training epochs by the deep learning system, the system discriminated 8 implant models with a mean area under the receiver operating characteristic curve of 0.991, accuracy of 97.9%, sensitivity of 88.6%, and specificity of 98.9% in the external testing dataset of 588 anteroposterior radiographs. The software classified implants at a mean speed of 0.02 seconds per image. CONCLUSION: An AI-based software demonstrated excellent internal and external validation. Although continued surveillance is necessary with implant library expansion, this software represents responsible and meaningful clinical application of AI with immediate potential to globally scale and assist in preoperative planning prior to revision THA.


Assuntos
Artroplastia de Quadril , Inteligência Artificial , Humanos , Estudos Retrospectivos , Curva ROC , Reoperação
8.
Am J Physiol Regul Integr Comp Physiol ; 323(5): R763-R775, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36189990

RESUMO

Migration of monocytes-macrophages plays an important role in phagocytosis of pathogens and cellular debris in a variety of pathophysiological conditions. Although epithelial Na+ channels (ENaCs) are required for normal migratory responses in other cell types, their role in macrophage migration signaling is unknown. To address this possibility, we determined whether ENaC message is present in several peripheral blood monocyte cell populations and tissue-resident macrophages in healthy humans using the Human Protein Atlas database (www.proteinatlas.org) and the mouse monocyte cell line RAW 264.7 using RT-PCR. We then determined that selective ENaC inhibition with amiloride inhibited chemotactic migration (∼50%), but not phagocytosis, of the mouse monocyte-macrophage cell line RAW 264.7. Furthermore, we generated a cell line stably expressing an NH2-terminal truncated αENaC to interrupt normal channel trafficking and found it suppressed migration. Prolonged exposure (48 h) of RAW 264.7 cells to proinflammatory cytokines interferon γ (IFNγ) and/or tumor necrosis factor α (TNFα) inhibited RAW 264.7 migration and abolished the amiloride (1 µM)-sensitive component of migration, a finding consistent with ENaC downregulation. To determine if proinflammatory cytokines regulate αENaC protein expression, cells were exposed to proinflammatory cytokines IFNγ (10 ng/mL, last 48 h) and TNFα (10 ng/mL, last 24 h). By Western blot analysis, we found whole cell αENaC protein is reduced ≥50%. Immunofluorescence demonstrated heterogeneous αENaC inhibition. Finally, we found that overnight exposure to amiloride stimulated morphological changes and increased polarization marker expression. Our findings suggest that ENaC may be a critical molecule in macrophage migration and polarization.


Assuntos
Canais Epiteliais de Sódio , Fator de Necrose Tumoral alfa , Camundongos , Animais , Humanos , Canais Epiteliais de Sódio/genética , Canais Epiteliais de Sódio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Amilorida/farmacologia , Interferon gama/farmacologia , Interferon gama/metabolismo , Citocinas/metabolismo , Macrófagos/metabolismo
9.
Clin Sci (Lond) ; 136(22): 1657-1659, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36409043

RESUMO

The precise control of whole-body calcium is essential for the maintenance of normal physiological function. Disruptions in calcium homeostasis can lead to pathology including osteoporosis, kidney stone formation, and cardiac arrythmias. During the 1960s and early 1970s, a full understanding of calcium metabolism was still emerging. This commentary spotlights a seminal Clinical Science paper published in 1972 that significantly advanced the field and contributed to the eventual approval of bisphosphonate drugs commonly used to treat postmenopausal osteoporosis, cancer metastases, and other calcium disorders.


Assuntos
Conservadores da Densidade Óssea , Cálculos Renais , Osteoporose , Humanos , Cálcio , Conservadores da Densidade Óssea/uso terapêutico , Osteoporose/tratamento farmacológico , Difosfonatos/uso terapêutico
10.
Eur Radiol ; 32(1): 533-541, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34268596

RESUMO

OBJECTIVES: To compare the diagnostic accuracy of generalist radiologists working in a community setting against abdominal radiologists working in an academic setting for the interpretation of MR when diagnosing acute appendicitis among emergency department patients. METHODS: This observational study examined MR image interpretation (non-contrast MR with diffusion-weighted imaging and intravenous contrast-enhanced MR) from a prospectively enrolled cohort at an academic hospital over 18 months. Eligible patients had an abdominopelvic CT ordered to evaluate for appendicitis and were > 11 years old. The reference standard was a combination of surgery and pathology results, phone follow-up, and chart review. Six radiologists blinded to clinical information, three each from community and academic practices, independently interpreted MR and CT images in random order. We calculated test characteristics for both individual and group (consensus) diagnostic accuracy then performed Chi-square tests to identify any differences between the subgroups. RESULTS: Analysis included 198 patients (114 women) with a mean age of 31.6 years and an appendicitis prevalence of 32.3%. For generalist radiologists, the sensitivity and specificity (95% confidence interval) were 93.8% (84.6-98.0%) and 88.8% (82.2-93.2%) for MR and 96.9% (88.7-99.8%) and 91.8% (85.8-95.5%) for CT. For fellowship-trained radiologists, the sensitivity and specificity were 96.9% (88.2-99.5%) and 89.6% (82.8-94%) for MR and 98.4% (90.5-99.9%) and 93.3% (87.3-96.7%) for CT. No statistically significant differences were detected between radiologist groups (p = 1.0, p = 0.53, respectively) or when comparing MR to CT (p = 0.21, p = 0.17, respectively). CONCLUSIONS: MR is a reliable, radiation-free imaging alternative to CT for the evaluation of appendicitis in community-based generalist radiology practices. KEY POINTS: • There was no significant difference in MR image interpretation accuracy between generalist and abdominal fellowship-trained radiologists when evaluating sensitivity (p = 1.0) and specificity (p = 0.53). • There was no significant difference in accuracy comparing MR to CT imaging for diagnosing appendicitis for either sensitivity (p = 0.21) or specificity (p = 0.17). • With experience, generalist radiologists enhanced their MR interpretation accuracy as demonstrated by improved interpretation sensitivity (OR 2.89 CI 1.44-5.77, p = 0.003) and decreased mean interpretation time (5 to 3.89 min).


Assuntos
Apendicite , Adulto , Apendicite/diagnóstico por imagem , Criança , Bolsas de Estudo , Feminino , Humanos , Radiologistas , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
11.
Biol Lett ; 18(6): 20220098, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35765810

RESUMO

Stimulation in one sensory modality can affect perception in a separate modality, resulting in diverse effects including illusions in humans. This can also result in cross-modal facilitation, a process where sensory performance in one modality is improved by stimulation in another modality. For instance, a simple sound can improve performance in a visual task in both humans and cats. However, the range of contexts and underlying mechanisms that evoke such facilitation effects remain poorly understood. Here, we demonstrated cross-modal stimulation in wild-caught túngara frogs, a species with well-studied acoustic preferences in females. We first identified that a combined visual and seismic cue (vocal sac movement and water ripple) was behaviourally relevant for females choosing between two courtship calls in a phonotaxis assay. We then found that this combined cross-modal stimulus rescued a species-typical acoustic preference in the presence of background noise that otherwise abolished the preference. These results highlight how cross-modal stimulation can prime attention in receivers to improve performance during decision-making. With this, we provide the foundation for future work uncovering the processes and conditions that promote cross-modal facilitation effects.


Assuntos
Percepção Auditiva , Percepção Visual , Estimulação Acústica/métodos , Animais , Anuros , Atenção , Percepção Auditiva/fisiologia , Discriminação Psicológica , Feminino , Percepção Visual/fisiologia
12.
Brain Behav Evol ; 97(3-4): 140-150, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34864726

RESUMO

As species change through evolutionary time, the neurological and morphological structures that underlie behavioral systems typically remain coordinated. This is especially important for communication systems, in which these structures must remain coordinated both within and between senders and receivers for successful information transfer. The acoustic communication of anurans ("frogs") offers an excellent system to ask when and how such coordination is maintained, and to allow researchers to dissociate allometric effects from independent correlated evolution. Anurans constitute one of the most speciose groups of vocalizing vertebrates, and females typically rely on vocalizations to localize males for reproduction. Here, we compile and compare data on various aspects of auditory morphology, hearing sensitivity, and call-dominant frequency across 81 species of anurans. We find robust, phylogenetically independent scaling effects of body size for all features measured. Furthermore, after accounting for body size, we find preliminary evidence that morphological evolution beyond allometry can correlate with hearing sensitivity and dominant frequency. These data provide foundational results regarding constraints imposed by body size on communication systems and motivate further data collection and analysis using comparative approaches across the numerous anuran species.


Assuntos
Anuros , Audição , Animais , Anuros/anatomia & histologia , Evolução Biológica , Tamanho Corporal , Feminino , Masculino , Reprodução
13.
Am J Physiol Heart Circ Physiol ; 320(2): H535-H548, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33275518

RESUMO

Preeclampsia is characterized by increases in blood pressure and proteinuria in late pregnancy, and neurological symptoms can appear in the form of headaches, blurred vision, cerebral edema, and, in the most severe cases, seizures (eclampsia). The causes for these cerebral manifestations remain unknown, so the use of animal models that mimic preeclampsia is essential to understanding its pathogenesis. The Dahl salt-sensitive (Dahl SS/jr) rat model develops spontaneous preeclampsia superimposed on chronic hypertension; therefore, we hypothesized that the Dahl SS/jr rat would display cerebrovascular features similar to those seen in human preeclampsia. Furthermore, we predicted that this model would allow for the identification of mechanisms underlying these changes. The pregnant Dahl SS/jr rat displayed increased cerebral edema and blood-brain barrier disruption despite tighter control of cerebral blood flow autoregulation and vascular smooth muscle myogenic tone. Analysis of cerebral endothelial cell morphology revealed increased opening of tight junctions, basement membrane dissolution, and vesicle formation. RNAseq analysis identified that genes related to endothelial cell tight junctions and blood-brain barrier integrity were differentially expressed in cerebral vessels from pregnant Dahl SS/jr compared with healthy pregnant Sprague Dawley rats. Overall, our data reveal new insights into mechanisms involved in the cerebrovascular dysfunction of preeclampsia.NEW & NOTEWORTHY This study uses the Dahl SS/jr rat as a preclinical model of spontaneous superimposed preeclampsia to demonstrate uncoupling of cerebral vascular permeability and blood-brain barrier disruption from cerebral blood flow autoregulatory dysfunction and myogenic tone. Additionally, the data presented in this study lay the foundational framework on which future experiments assessing specific transcellular transport components such as individual transporter protein expression and components of the vesicular transport system (caveolae) can be built to help reveal a potential direct mechanistic insight into the causes of cerebrovascular complications during preeclamptic pregnancies.


Assuntos
Barreira Hematoencefálica/metabolismo , Edema Encefálico/patologia , Permeabilidade Capilar , Células Endoteliais/ultraestrutura , Pré-Eclâmpsia/patologia , Animais , Membrana Basal/ultraestrutura , Barreira Hematoencefálica/ultraestrutura , Edema Encefálico/metabolismo , Vesículas Citoplasmáticas/ultraestrutura , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/ultraestrutura , Feminino , Pré-Eclâmpsia/metabolismo , Gravidez , Ratos , Ratos Endogâmicos Dahl , Ratos Sprague-Dawley , Junções Íntimas/ultraestrutura
14.
Am J Physiol Regul Integr Comp Physiol ; 321(2): R125-R138, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34105357

RESUMO

The pregnant Dahl salt-sensitive (S) rat is an established preclinical model of superimposed spontaneous preeclampsia characterized by exacerbated hypertension, increased urinary protein excretion, and increased fetal demise. Because of the underlying immune system dysfunction present in preeclamptic pregnancies in humans, we hypothesized that the pregnant Dahl S rat would also have an altered immune status. Immune system activation was assessed during late pregnancy in the Dahl S model and compared with healthy pregnant Sprague-Dawley (SD) rats subjected to either a sham procedure or a procedure to reduce uterine perfusion pressure (RUPP). Circulating immunoglobulin and cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA) and Milliplex bead assay, respectively, and percentages of circulating, splenic, and placental immune cells were determined using flow cytometry. The pregnant Dahl S rat exhibited an increase in CD4+ T cells, and specifically TNFα+CD4+ T cells, in the spleen compared with virgin Dahl S rats. The Dahl also had increased neutrophils and decreased B cells in the peripheral blood as compared with Dahl virgin rats. SD rats that received the RUPP procedure had increases in circulating monocytes and increased IFN-É£+CD4+ splenic T cells. Together these findings suggest that dysregulated T cell activity is an important factor in both the pregnant Dahl S rats and SD rats after the RUPP procedure.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Citocinas/sangue , Imunoglobulinas/sangue , Placenta/imunologia , Pré-Eclâmpsia/imunologia , Baço/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Modelos Animais de Doenças , Feminino , Idade Gestacional , Neutrófilos/imunologia , Neutrófilos/metabolismo , Fenótipo , Placenta/metabolismo , Pré-Eclâmpsia/sangue , Gravidez , Ratos Endogâmicos Dahl , Ratos Sprague-Dawley , Baço/metabolismo
15.
Clin Sci (Lond) ; 135(1): 101-103, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33404049

RESUMO

Most scientific investigators conduct well-designed and controlled preclinical experiments generating data that are difficult to explain, contrast with existing scientific dogma, or represent a perceived negative result. It is common for these findings to remain hidden away in a drawer from the greater scientific community. However, these unseen results can lead to publication bias, have the potential to significantly advance scientific disciplines if they are published, and can help investigators avoid repeating experiments that have already been done, thus saving money and time. Moreover, these unexpected data may actually have significance if re-interpreted leading to new hypotheses. This editorial commentary highlights a novel user-friendly tool developed by Bernard and colleagues (REF) to help investigators determine appropriate options for disseminating unpublished data in order to make them available to the broader scientific community. In addition, this commentary serves as an announcement for an upcoming special call for papers on meta-research to be published in Clinical Science. Meta-research is the evaluation and study of existing scientific literature and data. It is an evolving field dedicated to improving rigor and reproducibility in science, an endeavor to which Clinical Science and Portland Press are committed.


Assuntos
Reprodutibilidade dos Testes , Humanos , Viés de Publicação
16.
Horm Behav ; 128: 104891, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33197465

RESUMO

Arginine vasotocin (AVT) and its homolog arginine vasopressin (AVP) modulate social behavior, including social communication. In anuran amphibians, male-male competition and female mate choice rely heavily on acoustic signaling. Behavioral experiments show that AVT influences motivation to call and vocal production. It may also influence how males process and respond to socially relevant auditory stimuli, but few studies have explored this possibility in this taxon. Túngara frogs produce a "whine" that is used for species recognition; in competition with other males they append one or more attractive "chucks" to the whine. Frequency modulation in the whine is an important cue for recognizing conspecifics, and gating of conspecific signals begins in the auditory midbrain. We used dynamic playback experiments to investigate the effects of exogenous AVT on males' responses to stimuli with species-typical and altered frequency modulation. We used avoidance of call overlap as evidence that a male recognizes a stimulus as salient and the production of attractive chucks as evidence of his competitive response to a proximate rival. We used call rate, whine duration, and whine frequency as measures of motivation and motor production. Males responded selectively to a stimulus with species-typical frequency modulation. Following treatment with AVT, they increased call rate and altered whines and chucks in a way that suggests increased air flow during the whine. We did not, however, find evidence that treatment with AVT alters the salience of frequency modulation in recognizing and responding to acoustic signals, at least for the stimuli used in this study.


Assuntos
Vasotocina , Vocalização Animal , Acústica , Animais , Anuros , Feminino , Masculino , Comportamento Sexual Animal , Comportamento Social , Vasotocina/farmacologia
17.
J Exp Biol ; 224(12)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34142696

RESUMO

Communication systems often include a variety of components, including those that span modalities, which may facilitate detection and decision-making. For example, female túngara frogs and fringe-lipped bats generally rely on acoustic mating signals to find male túngara frogs in a mating or foraging context, respectively. However, two additional cues (vocal sac inflation and water ripples) can enhance detection and choice behavior. To date, we do not know the natural variation and covariation of these three components. To address this, we made detailed recordings of calling males, including call amplitude, vocal sac volume and water ripple height, in 54 frogs (2430 calls). We found that all three measures correlated, with the strongest association between the vocal sac volume and call amplitude. We also found that multimodal models predicted the mass of calling males better than unimodal models. These results demonstrate how multimodal components of a communication system relate to each other and provide an important foundation for future studies on how receivers integrate and compare complex displays.


Assuntos
Quirópteros , Corte , Animais , Anuros , Feminino , Masculino , Comportamento Sexual Animal , Vocalização Animal
18.
J Exp Biol ; 224(Pt 1)2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33188061

RESUMO

Noise is a common problem in animal communication. We know little, however, about how animals communicate in the presence of noise using multimodal signals. Multimodal signals are hypothesised to be favoured by evolution because they increase the efficacy of detection and discrimination in noisy environments. We tested the hypothesis that female túngara frogs' responses to attractive male advertisement calls are improved in noise when a visual signal component is added to the available choices. We tested this at two levels of decision complexity (two and three choices). In a two-choice test, the presence of noise did not reduce female preferences for attractive calls. The visual component of a calling male, associated with an unattractive call, also did not reduce preference for attractive calls in the absence of noise. In the presence of noise, however, females were more likely to choose an unattractive call coupled with the visual component. In three-choice tests, the presence of noise alone reduced female responses to attractive calls and this was not strongly affected by the presence or absence of visual components. The responses in these experiments fail to support the multimodal signal efficacy hypothesis. Instead, the data suggest that audio-visual perception and cognitive processing, related to mate choice decisions, are dependent on the complexity of the sensory scene.


Assuntos
Anuros , Comportamento Sexual Animal , Comunicação Animal , Animais , Feminino , Masculino , Ruído , Percepção Visual , Vocalização Animal
19.
J Anim Ecol ; 90(6): 1455-1465, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33666233

RESUMO

Animal choruses, such as those found in insects and frogs, are often intermittent. Thus, females sampling males in the chorus might have to remember the location of the potential mates' calls during periods of silence. Although a number of studies have shown that frogs use and prefer multimodal mating signals, usually acoustic plus visual, it is not clear why they do so. Here we tested the hypothesis that preference for multimodal signals over unimodal signals might be due to multimodal signals instantiating longer memories than unimodal signals, particularly during the inter-chorus intervals. We tested this hypothesis in serrate-legged small treefrogs Kurixalus odontotarsus whose males produce advertisement calls accompanied by conspicuous vocal sac inflation. Females were tested with acoustic and acoustic + visual (video of inflating-deflating vocal sac) mating calls. We found that females prefer multimodal calls over unimodal, audio-only calls. Furthermore, multimodal calls are still preferred after a silent period of up to 30 s, a time that spans the average silent period of the chorus. This was not true of unimodal calls. Our results demonstrate that a multimodal signal can engage longer working memory than a unimodal signal, and thus female memory might favour the evolution of multimodal signals in males through sexual selection. Selection might also favour female preference for multimodal signals if longer memory facilitates mate searching and assessment. Our study does not allow us to elucidate the sequence of evolution of this trait and preference.


Assuntos
Preferência de Acasalamento Animal , Vocalização Animal , Animais , Anuros , Feminino , Masculino , Memória de Curto Prazo , Comportamento Sexual Animal
20.
Sensors (Basel) ; 21(13)2021 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-34199026

RESUMO

Near infrared (NIR) remote sensing has applications in vegetation analysis as well as geological investigations. For extra-terrestrial applications, this is particularly relevant to Moon, Mars and asteroid exploration, where minerals exhibiting spectral phenomenology between 600 and 800 nm have been identified. Recent progress in the availability of processors and sensors has created the possibility of development of low-cost instruments able to return useful scientific results. In this work, two Raspberry Pi camera types and a panchromatic astronomy camera were trialed within a pushbroom sensor to determine their utility in measuring and processing the spectrum in reflectance. Algorithmic classification of all 15 test materials exhibiting spectral phenomenology between 600 and 800 nm was easily performed. Calibration against a spectrometer considers the effects of the sensor, inherent image processing pipeline and compression. It was found that even the color Raspberry Pi cameras that are popular with STEM applications were able to record and distinguish between most minerals and, contrary to expectations, exploited the infra-red secondary transmissions in the Bayer filter to gain a wider spectral range. Such a camera without a Bayer filter can markedly improve spectral sensitivity but may not be necessary.


Assuntos
Geologia , Minerais , Minerais/análise
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