Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 92
Filtrar
1.
Acta Ortop Mex ; 38(2): 82-87, 2024.
Artículo en Español | MEDLINE | ID: mdl-38782472

RESUMEN

INTRODUCTION: ligamentous injuries of the distal tibiofibular syndesmosis resulting in its opening are common occurrences in traumatology; however, their diagnosis poses a challenge for orthopedic surgeons. The tibioastragaloid mortise radiograph view is the most commonly used method for diagnosing this type of injury, but its reliability is compromised due to variations in ankle positioning during the study, which often depend on the operator. OBJECTIVE: to demonstrate that the designed device achieves a correct and consistent radiographic image of the distal tibiofibular syndesmosis in the mortise view. MATERIAL AND METHODS: we present a prospective, longitudinal, observational study. We designed a polypropylene device that maintains the ankle at 90 degrees of dorsiflexion and 15 degrees of internal rotation. The device was used to take mortise view radiographs of healthy ankles, and corresponding measurements were taken to assess the syndesmosis. RESULTS: we evaluated a total of 46 radiographs of healthy ankles, with a predominance of left ankles. The obtained measurements were as follows: anterior tibiofibular distance (ATFD) ranged from 3 to 6 mm, posterior tibiofibular distance (PTFD) ranged from 1 to 3 mm, tibiofibular clear space (TFCS) ranged from 2 to 3 mm, and a Merle D'Aubigne ratio of 2:1 was observed in all ankles. When comparing the measurements obtained with those established by Harper and Keller, no statistically significant difference was found (2 < 5). CONCLUSION: with the use of the designed device, we achieved a correct and consistent radiographic image of the mortise and the distal tibiofibular syndesmosis.


INTRODUCCIÓN: las lesiones ligamentarias de la sindesmosis tibioperonea distal que ocasionan apertura de la misma son muy frecuentes en traumatología; sin embargo, su diagnóstico es un reto para el cirujano ortopedista. La radiografía de la mortaja tibioastragalina es el método más utilizado para el diagnóstico de este tipo de lesiones, pero es poco confiable ya que la posición del tobillo durante el estudio suele variar dependiendo del operador. OBJETIVO: demostrar que con el uso del dispositivo diseñado se logra una imagen radiográfica correcta y constante de la sindesmosis tibioperonea distal en la proyección de la mortaja. MATERIAL Y MÉTODOS: estudio prospectivo, longitudinal y observacional. Diseñamos un dispositivo de polipropileno que mantiene el tobillo a 90 grados de dorsiflexión y rotación interna de 15 grados. Aplicamos el dispositivo para tomar radiografías de la mortaja en tobillos sanos y les realizamos las mediciones correspondientes para valorar la sindesmosis. RESULTADOS: valoramos un total de 46 radiografías de tobillos sanos, con un predominio de tobillos izquierdos. Las mediciones conseguidas fueron las siguientes: espacio tibioperoneo (ETP) de 3 a 6 mm, la superposición tibioperonea (STP) de 1 a 3 mm, espacio astrágalo-tibial medial (EATM) de 2 a 3 mm y una relación de Merle D'Aubigne de 2:1 en todos los tobillos. Al comparar las mediciones obtenidas con las establecidas por Harper y Keller, no se encontró una diferencia estadísticamente significativa (2 < 5). CONCLUSIÓN: con el uso del dispositivo diseñado, obtuvimos una correcta y constante imagen radiográfica de la mortaja y la sindesmosis tibioperonea distal.


Asunto(s)
Articulación del Tobillo , Diseño de Equipo , Radiografía , Humanos , Estudios Prospectivos , Radiografía/métodos , Masculino , Articulación del Tobillo/diagnóstico por imagen , Femenino , Adulto , Tibia/diagnóstico por imagen , Estudios Longitudinales , Peroné/diagnóstico por imagen , Peroné/lesiones , Astrágalo/diagnóstico por imagen , Astrágalo/lesiones , Adulto Joven , Traumatismos del Tobillo/diagnóstico por imagen , Polipropilenos , Persona de Mediana Edad
2.
Rev Sci Instrum ; 93(10): 103517, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-36319330

RESUMEN

The C-2W experimental device at TAE Technologies utilizes neutral beam injection and edge biasing to sustain long-lived, stable field reversed configuration (FRC) plasma. An ongoing effort is under way to optimize the electrode biasing system, which provides boundary control to stabilize the FRC. To this end, tomography offers a powerful and non-invasive technique as tomographic reconstruction of the FRC emission profile provides an important assessment of global stability. Recently, a new signal acquisition system was implemented on a bolometer array dedicated to tomography on C-2W, significantly enhancing the signal-to-noise of the collected data. The array consists of 300 simultaneously digitized photodiode channels that respond to a broad range of wavelengths, from soft x-ray to near-infrared, as well as energetic particles, yielding 180 unique lines of sight that intersect a toroidal plane of the FRC near the mid-plane. Utilizing the collected photo-signals from a set of plasma discharges in which the electrode biasing was intentionally terminated mid-shot, time-resolved reconstruction of the plasma emissivity is achieved via pixel-based 1D and 2D tomographic algorithms, revealing sharply annular profiles with a clear magnetohydrodynamic (MHD) mode structure. In addition, reconstruction of the plasma center-of-emission trajectories via a centroid algorithm applied to the same set of discharges demonstrates a cyclical plasma wobble. Crucially, both the tomography reconstruction and centroid reconstruction indicate an n = 1 toroidal mode that reverses from the electron diamagnetic direction to the ion diamagnetic direction and grows in amplitude after bias termination, qualitatively consistent with the expected stabilizing effect of electrodes.

3.
Int J Biol Macromol ; 109: 1239-1245, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29175525

RESUMEN

The inhibition of electrons-holes recombination and enhancement of visible light photocatalytic activity were accomplished by the synthesized TiO2/CS nanocomposites system. In this present work, the different weight ratio of TiO2 and chitosan (75:25, 50:50 and 25:75) nanocomposites were synthesized via two-step method. After that, the existing functional groups, size and structure of the nanocomposites system were characterized via FT-IR, TEM and XRD measurements. The band gap of the prepared materials and its excitation and emission spectra were elevated through UV-vis and PL analyses. Moreover, the MO and MB degradation capability of the synthesized TiO2/CS nanocomposites was optimized, and the outcomes are described in detail.


Asunto(s)
Quitosano/química , Luz , Nanocompuestos/química , Procesos Fotoquímicos , Titanio/química , Catálisis , Nanopartículas del Metal/química , Nanocompuestos/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
4.
Med Hypotheses ; 85(1): 94-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25913541

RESUMEN

Schëuermanns kyphosis is usually observed with a mild idiopathic scoliosis, and there is parity between these two diseases. The aim of this work is to establish a hypothesis about the existence of a biomechanical causal relationship between Schëuermann's kyphosis and scoliosis. To achieve this, a literature review was conducted. A simple mechanical model of the passive thoracolumbar subsystem was created to support part of the discussion. This mechanical model describes the passive thoracolumbar subsystem under ideal conditions of equilibrium. After giving consideration to the system under these conditions, some of the geometrical changes that may be found in Schëuermanns kyphosis are considered. Next, this work discusses the evolution of the spine, taking into account its relationship with stable equilibrium, which the passive subsystem tends toward. We hypothesized about the postural response of the body to compensate for possible situations of imbalance. In conclusion, it can be found that a change in the alignment of the spine may occur due to the postural adaptation of the body to an inadequate mechanical situation that may lead to scoliotic deformity of the spine.


Asunto(s)
Enfermedad de Scheuermann/fisiopatología , Escoliosis/fisiopatología , Fenómenos Biomecánicos , Humanos , Enfermedad de Scheuermann/etiología , Escoliosis/etiología
5.
Mol Psychiatry ; 19(10): 1095-105, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24732670

RESUMEN

Circulating triglycerides (TGs) normally increase after a meal but are altered in pathophysiological conditions, such as obesity. Although TG metabolism in the brain remains poorly understood, several brain structures express enzymes that process TG-enriched particles, including mesolimbic structures. For this reason, and because consumption of high-fat diet alters dopamine signaling, we tested the hypothesis that TG might directly target mesolimbic reward circuits to control reward-seeking behaviors. We found that the delivery of small amounts of TG to the brain through the carotid artery rapidly reduced both spontaneous and amphetamine-induced locomotion, abolished preference for palatable food and reduced the motivation to engage in food-seeking behavior. Conversely, targeted disruption of the TG-hydrolyzing enzyme lipoprotein lipase specifically in the nucleus accumbens increased palatable food preference and food-seeking behavior. Finally, prolonged TG perfusion resulted in a return to normal palatable food preference despite continued locomotor suppression, suggesting that adaptive mechanisms occur. These findings reveal new mechanisms by which dietary fat may alter mesolimbic circuit function and reward seeking.


Asunto(s)
Encéfalo/metabolismo , Conducta Alimentaria/fisiología , Motivación/fisiología , Recompensa , Triglicéridos/sangre , Anfetamina/farmacología , Animales , Arterias Carótidas/metabolismo , Estimulantes del Sistema Nervioso Central/farmacología , Lipoproteína Lipasa/metabolismo , Masculino , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiología
6.
Oecologia ; 173(1): 83-93, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23386048

RESUMEN

Animals often announce their unprofitability to predators through conspicuous coloured signals. Here we tested whether the apparently conspicuous colour designs of the four European Coraciiformes and Upupiformes species may have evolved as aposematic signals, or whether instead they imply a cost in terms of predation risk. Because previous studies suggested that these species are unpalatable, we hypothesized that predators could avoid targeting them based on their colours. An experiment was performed where two artificial models of each bird species were exposed simultaneously to raptor predators, one painted so as to resemble the real colour design of these birds, and the other one painted using cryptic colours. Additionally, we used field data on the black kite's diet to compare the selection of these four species to that of other avian prey. Conspicuous models were attacked in equal or higher proportions than their cryptic counterparts, and the attack rate on the four species increased with their respective degree of contrast against natural backgrounds. The analysis of the predator's diet revealed that the two least attacked species were negatively selected in nature despite their abundance. Both conspicuous and cryptic models of one of the studied species (the hoopoe) received fewer attacks than cryptic models of the other three species, suggesting that predators may avoid this species for characteristics other than colour. Globally, our results suggest that the colour of coraciiforms and upupiforms does not function as an aposematic signal that advises predators of their unprofitability, but also that conspicuous colours may increase predation risk in some species, supporting thus the handicap hypothesis.


Asunto(s)
Comunicación Animal , Aves/anatomía & histología , Color , Conducta Predatoria , Rapaces/fisiología , Animales , Señales (Psicología) , Dieta , Factores de Riesgo
7.
Oecologia ; 173(2): 399-408, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23443357

RESUMEN

Chromatic signals of offspring quality have been shown to play a role in parent-offspring communication in diurnal birds, but are assumed to be useless in dim light conditions because colour-based discrimination probably requires more light. A major ecological and evolutionary conundrum in this scenario is why the nestlings of some nocturnal owls display colourful beaks. Here, we test the hypothesis that yellow bill coloration of owlets of the nocturnal little owl Athene noctua may function as a chromatic signal revealing to parents aspects of quality of their offspring. In a first step, we examined physical variation in bill coloration and its covariation with owlet quality. Secondly, we studied parental provisioning in relation to an experimental manipulation of bill coloration of owlets. Bills of owlets showed higher within-nest variation in yellow-red chroma than in brightness. Plasma carotenoid concentration and nestling immunological status were not associated with chromatic or achromatic features of the bill. Interestingly, however, heavier owlets displayed more yellow bills than lighter ones. The effect of bill coloration on parental favouritism changed with brood size. Parents holding large broods preferentially fed owlets with enhanced over reduced yellow bill coloration, whereas those with small broods did not significantly bias feeding in relation to owlet bill coloration. Our results, based on integration of objective spectrophotometric assessment of colour and experimental procedures, confirm that parent little owls use bill coloration to reveal information on owlet body mass to adjust their feeding strategies, thus highlighting the importance of considering potential chromatic signals for a full comprehension of parent-offspring communication processes in nocturnal bird species.


Asunto(s)
Color , Comportamiento de Nidificación , Pigmentación , Estrigiformes/fisiología , Animales , Carotenoides/sangre , Cromatografía Líquida de Alta Presión , Fenotipo , España , Análisis Espectral , Percepción Visual
10.
Actas Dermosifiliogr ; 103(1): 44-50, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22464597

RESUMEN

BACKGROUND: The melanocortin-1 receptor (MC1R) is an important risk factor for melanoma due to its role in the production of melanin in response to sun exposure. OBJECTIVES: To analyze the phenotypic and histologic characteristics of cutaneous melanoma in patients carrying mutations in MC1R and assess the influence of sun exposure on the occurrence of melanoma. MATERIAL AND METHODS: A total of 224 patients with a diagnosis of melanoma seen in the Department of Dermatology at Hospital General Universitario Gregorio Marañón in Madrid, Spain between September 2004 and December 2009 were included in the study. The genomic sequence of MC1R was analyzed by polymerase chain reaction. RESULTS: At least one of the following MC1R variants was present in 58% of the patients: V60L, V92M, I155T, R160W, D294H, and R163Q. Carriers of those variants had a history of sunburn (P=.018) and melanomas located on areas with intermittent sun exposure (P=.019), and the majority had a diagnosis of superficial spreading melanoma. These associations were especially significant in patients with the R160W and D294H variants. Carriers of R160W also had melanomas associated with melanocytic nevi (P=.028). CONCLUSIONS: The results of our study suggest that there may be a relationship between the expression of certain MC1R variants and sun exposure, history of sunburn, and skin type. They also indicate a higher frequency of superficial spreading melanomas and melanomas associated with melanocytic nevi in patients carrying certain mutations in MC1R.


Asunto(s)
Melanoma/genética , Proteínas de Neoplasias/genética , Neoplasias Inducidas por Radiación/genética , Polimorfismo de Nucleótido Simple , Receptor de Melanocortina Tipo 1/genética , Neoplasias Cutáneas/genética , Luz Solar/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Análisis Mutacional de ADN , ADN de Neoplasias/genética , Femenino , Humanos , Masculino , Melanoma/epidemiología , Melanoma/etiología , Melanoma/patología , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/epidemiología , Neoplasias Inducidas por Radiación/patología , Nevo Pigmentado/epidemiología , Nevo Pigmentado/genética , Fenotipo , Receptor de Melanocortina Tipo 1/fisiología , Análisis de Secuencia de ADN , Neoplasias Cutáneas/epidemiología , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/patología , España/epidemiología , Quemadura Solar/epidemiología , Adulto Joven
11.
Biol Lett ; 8(4): 502-4, 2012 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-22399785

RESUMEN

Many animals react to danger by producing chemical cues that can be smelled by others, which is called the smell of fear. Some bird species produce chemical compounds when threatened, such as nestlings of the Eurasian roller Coracias garrulus that vomit an odorous orange liquid when scared in their nests. Here, we experimentally explore the possibility that parents were informed about recent predation attempts at their nests through the olfaction of this vomit. Parents of nests treated with nestling vomit delayed their entrance to nests and decreased their provisioning rate in comparison with parents of nests treated with an odorous control. These results demonstrate that adult rollers are able to smell the fear of offspring and show for the first time in birds that a scent produced during an interspecific challenge has a role in an intraspecific communication scenario.


Asunto(s)
Conducta Animal/fisiología , Aves/fisiología , Miedo/psicología , Comportamiento de Nidificación/fisiología , Olfato/fisiología , Animales , Señales (Psicología) , Odorantes , Especificidad de la Especie
12.
Actas Dermosifiliogr ; 103(1): 44-50, 2012.
Artículo en Español | MEDLINE | ID: mdl-21737053

RESUMEN

BACKGROUND: The melanocortin-1 receptor (MC1R) is an important risk factor for melanoma due to its role in the production of melanin in response to sun exposure. OBJECTIVES: To analyze the phenotypic and histologic characteristics of cutaneous melanoma in patients carrying mutations in MC1R and assess the influence of sun exposure on the occurrence of melanoma. MATERIAL AND METHODS: A total of 224 patients with a diagnosis of melanoma seen in the Department of Dermatology at Hospital General Universitario Gregorio Marañón in Madrid, Spain between September 2004 and December 2009 were included in the study. The genomic sequence of MC1R was analyzed by polymerase chain reaction. RESULTS: At least one of the following MC1R variants was present in 58% of the patients: V60L, V92M, I155T, R160W, D294H, and R163Q. Carriers of those variants had a history of sunburn (P=.018) and melanomas located on areas with intermittent sun exposure (P=.019), and the majority had a diagnosis of superficial spreading melanoma. These associations were especially significant in patients with the R160W and D294H variants. Carriers of R160W also had melanomas associated with melanocytic nevi (P=.028). CONCLUSIONS: The results of our study suggest that there may be a relationship between the expression of certain MC1R variants and sun exposure, history of sunburn, and skin type. They also indicate a higher frequency of superficial spreading melanomas and melanomas associated with melanocytic nevi in patients carrying certain mutations in MC1R.


Asunto(s)
Melanoma/genética , Melanoma/patología , Mutación , Polimorfismo Genético , Receptor de Melanocortina Tipo 1/genética , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Adulto Joven
13.
Actas Dermosifiliogr ; 102(8): 623-6, 2011 Oct.
Artículo en Español | MEDLINE | ID: mdl-21349475

RESUMEN

The diagnosis of pigmented actinic keratosis can be complicated in clinical practice. The differential diagnosis with lentigo maligna melanoma can be difficult due to common clinical and dermoscopic characteristics. We present 5 cases of pigmented actinic keratosis in 4 patients. The most common dermoscopic finding was a grayish-brown granulation with a perifollicular distribution, present in all lesions, followed by rhomboidal structures in 4 cases, and an annular-granular pattern in 3. In no case were asymmetrical pigmented follicular openings observed. We draw attention to key findings that aid preoperative diagnosis of pigmented actinic keratosis.


Asunto(s)
Dermoscopía , Dermatosis Facial/diagnóstico , Queratosis Actínica/diagnóstico , Nariz/patología , Pigmentación de la Piel , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Epidermis/química , Epidermis/patología , Dermatosis Facial/patología , Dermatosis Facial/cirugía , Femenino , Humanos , Peca Melanótica de Hutchinson/diagnóstico , Queratinocitos/ultraestructura , Queratosis Actínica/patología , Queratosis Actínica/cirugía , Masculino , Melaninas/análisis , Persona de Mediana Edad
15.
J Evol Biol ; 24(2): 314-25, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21054625

RESUMEN

The obligate avian brood parasitic common cuckoo Cuculus canorus comprises different strains of females that specialize on particular host species by laying eggs of a constant type that often mimics those of the host. Whether cuckoos are locally adapted for mimicking populations of the hosts on which they are specialized has never been investigated. In this study, we first explored the possibility of local adaptation in cuckoo egg mimicry over a geographical mosaic of selection exerted by one of its main European hosts, the reed warbler Acrocephalus scirpaceus. Secondly, we investigated whether cuckoos inhabiting reed warbler populations with a broad number of alternative suitable hosts at hand were less locally adapted. Cuckoo eggs showed different degrees of mimicry to different reed warbler populations. However, cuckoo eggs did not match the egg phenotypes of their local host population better than eggs of other host populations, indicating that cuckoos were not locally adapted for mimicry on reed warblers. Interestingly, cuckoos exploiting reed warblers in populations with a relatively larger number of co-occurring cuckoo gentes showed lower than average levels of local adaptation in egg volume. Our results suggest that cuckoo local adaptation might be prevented when different cuckoo populations exploit more or fewer different host species, with gene flow or frequent host switches breaking down local adaptation where many host races co-occur.


Asunto(s)
Adaptación Fisiológica/genética , Adaptación Fisiológica/fisiología , Evolución Biológica , Aves/genética , Aves/fisiología , Comportamiento de Nidificación , Animales , Demografía , Europa (Continente) , Femenino , Variación Genética , Óvulo
16.
J Evol Biol ; 23(1): 226-30, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19895653

RESUMEN

We have recently published support to the hypothesis that visual systems of parents could affect nestling detectability and, consequently, influences the evolution of nestling colour designs in altricial birds. We provided comparative evidence of an adjustment of nestling colour designs to the visual system of parents that we have found in a comparative study on 22 altricial bird species. In this issue, however, Renoult et al. (J. Evol. Biol., 2009) question some of the assumptions and statistical approaches in our study. Their argumentation relied on two major points: (1) an incorrect assignment of vision system to four out of 22 sampled species in our study; and (2) the use of an incorrect approach for phylogenetic correction of the predicted associations. Here, we discuss in detail re-assignation of vision systems in that study and propose alternative interpretation for current knowledge on spectrophotometric data of avian pigments. We reanalysed the data by using phylogenetic generalized least squares analyses that account for the alluded limitations of phylogenetically independent contrasts and, in accordance with the hypothesis, confirmed a significant influence of parental visual system on gape coloration. Our results proved to be robust to the assumptions on visual system evolution for Laniidae and nocturnal owls that Renoult et al. (J. Evol. Biol., 2009) study suggested may have flawed our early findings. Thus, the hypothesis that selection has resulted in increased detectability of nestling by adjusting gape coloration to parental visual systems is currently supported by our comparative data.


Asunto(s)
Percepción de Color , Visión de Colores , Passeriformes/fisiología , Estrigiformes/fisiología , Animales , Color , Passeriformes/anatomía & histología , Passeriformes/clasificación , Filogenia , Estrigiformes/anatomía & histología , Estrigiformes/clasificación
17.
J Evol Biol ; 23(2): 293-301, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20002251

RESUMEN

Hosts of cuckoos have evolved defences allowing them to discriminate and reject parasite eggs. Mechanisms of discrimination are mostly visually mediated, and have been studied using approaches that do not account for what the receiver (i.e. host) actually can discriminate. Here, for the first time we apply a perceptual model of colour discrimination to study behavioural responses to natural variation in parasite egg appearance in chaffinches Fringilla coelebs. Discrimination of parasite eggs gradually increased with increasing differences in chromatic contrasts as perceived by birds between parasite and host eggs. These results confirm that colour differences of the eggs as perceived by birds are important integral parts of a matching signal used by chaffinch hosts.


Asunto(s)
Percepción de Color , Comportamiento de Nidificación , Pájaros Cantores , Animales , Femenino , Interacciones Huésped-Parásitos , Óvulo
18.
Nutr Hosp ; 24(2): 138-43, 2009.
Artículo en Español | MEDLINE | ID: mdl-19593482

RESUMEN

Obesity is considered a chronic and epidemic illness, hece difficult to treat. As conservative treatment has a high rate of failure, and considering morbimortality and sequels of surgery, less invasive techniques appeared to contribute to the treatment of this illness. The most implanted technique nowadays is the Intragastric Balloon, considered more efficient as conservative treatments and with less risks tan surgery, but having today a lack of consensus on indications and few information on his limitations, while its apparition in medias promote an important expansion in the 4 last years. In this publication, we do a critical revision, and describe limitations of this treatment, based on the evidences given by literature. We conclude this revision with some recommendations concerning the technique and indications, material and human requiring, need of a Multidisciplinary Team, as well as an adequate control and following.


Asunto(s)
Balón Gástrico , Obesidad/terapia , Humanos , Guías de Práctica Clínica como Asunto
20.
J Evol Biol ; 22(2): 376-86, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19196385

RESUMEN

Hitherto, most of the investigation on the perceptual efficacy of begging signals has dwelled on how patterns of nestling colouration adjust to predominant nest luminosity. However, visual sensitivity of birds varies across species, which raises the question of whether colouration of traits involved in begging displays is adjusted to parent visual capacities. Here, by comparing nestling colouration and visual sensitivity across 22 altricial bird species, we provide a first test of this hypothesis. Firstly, we assessed differences in performance of typical UV-tuned and violet-tuned bird eyes when looking at the nestling traits under the light regimes prevailing at their nests. Secondly, while controlling for common ancestry in a comparative approach, we explored variation in colouration of nestlings in relation to parent visual system. The colour discrimination model indicated a general higher performance of the ultraviolet over the violet eye at detecting gape and body skin traits in either open- or hole-nest light conditions. Gape colouration was associated with parental visual system as the nestlings of UVS species displayed more yellow and less pure ultraviolet mouths than the nestlings of VS species. Thus, our results agree with an adaptive parent-offspring communication scenario where the nestlings' colours tuned the perception capacities of their parents.


Asunto(s)
Aves/fisiología , Pigmentación/fisiología , Visión Ocular/fisiología , Animales , Tamaño de la Nidada , Femenino , Modelos Lineales , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...