Pigment-based coloration is prevalent in animals, but its expression greatly varies across species, populations, and even among individuals in the same populations. Some animals are highly pigmented and thus have conspicuous coloration, whereas others are modestly pigmented and thus have drab coloration. A possible explanation for the variety in pigmentation is a resource-based tradeoff, in which resources invested in pigmentation are unavailable for other functional traits, and thus animals that need to invest in the latter have limited resources to invest in pigmentation.
View Article and Find Full Text PDFDifferential migration strategies favour different sets of characteristics, including sexually selected ornamentation. Such phenotypic variation is particularly evident in a population with partial migration, where migrants and nonmigrants co-exist. Partial migration provides insights into the link among migration, local environment, and ornamentation, although empirical studies remain scarce.
View Article and Find Full Text PDFWhile numerous studies have confirmed sexual selection for ornamental traits in animals, it remains unclear about how animals exaggerate ornamentation across traits. I found that some Asian barn swallows possessed "pseudo-tail spots" on their undertail coverts adjacent to a well-known sexual signal, the white tail spots. A close inspection showed their remarkable resemblance, and, as a consequence, pseudo-tail spots appear to add white spots to the uniformly black central tail feathers, increasing the total number and area of white spots when spread tails are viewed from below.
View Article and Find Full Text PDFHigh-grade fetal lung adenocarcinoma (H-FLAC) is a rare type of tumor. There have been no reports demonstrating the degree of metastatic susceptibility of this tumor type. In this report, we describe a case in which 15% of the adenocarcinoma components were H-FLAC diagnosed as the cause of lymph node metastasis.
View Article and Find Full Text PDFThe cost of ornamentation is often measured experimentally to study the relative importance of sexual and viability selection for ornamentation, but these experiments can lead to a misleading conclusion when compensatory trait is ignored. For example, a classic experiment on the outermost tail feathers in the barn swallow explains that the concave (or U-shaped) aerodynamic performance cost of the outermost tail feathers would be the evolutionary outcome through viability selection for optimal tail length, but this conclusion depends on the assumption that compensatory traits do not cause reduced performance. Using a simple "toy model" experiment, I demonstrated that ornamentation evolved purely though sexual selection can produce a concave cost function under the presence of compensatory traits, which was further reinforced by a simple mathematical model.
View Article and Find Full Text PDFSexual selection can in theory lead to positive and negative effect on population-level fitness and hence population increase/decline in our changing world, but the empirical evidence is scarce. Using a phylogenetic comparative approach, we examined whether and how different sexually selected ornaments affect recent population trends and extinction risk in swallows (Aves: Hirundininae). We found that population trends decreased with increasing depth of male tails, that is a well-known sexually selected trait, and increased with increasing score of reddish plumage coloration, another sexually selected ornament.
View Article and Find Full Text PDFWhether sexual or viability selection drives the evolution of ornamental traits is often unclear because current function does not clarify evolutionary history, particularly when the ornamentation is a modified version of the functional traits. Here, using a phylogenetic comparative approach, we studied how deeply forked tails-a classic example of sexually selected traits that might also be a mechanical device for enhancing aerodynamic ability-evolved in two groups of aerial foragers, swallows (family: Hirundinidae) and swifts (family: Apodidae). Although apparent fork depth, the target of sexual selection, increases with increasing outermost tail feather length, fork depth can also increase with decreasing central tail feather length, which impairs the lift generated by the tail.
View Article and Find Full Text PDFEnviron Health Prev Med
December 2019
Background: Promotion of oral health in children is recognized as one of the components of health-promoting schools (HPSs). However, few studies have addressed supportive school environments for children's oral health. This study aimed to evaluate the status of dental caries in school children at HPSs, with the objective of examining the impact of a supportive school environment for oral health, considering the lifestyles of individual children and the socioeconomic characteristics of their communities.
View Article and Find Full Text PDFSperm competition can theoretically affect sperm morphology; however, it remains unclear whether and how sperm morphology tracks the intensity of sperm competition in each population. The barn swallow is a model species used in the study of sexual selection, and exhibits considerable variation in extra-pair paternity (percentage extra-pair young, ca. 3-30%) among populations.
View Article and Find Full Text PDFPigment-based plumage coloration and its physiological properties have attracted many researchers to explain the evolution of such ornamental traits. These studies, however, assume the functional importance of the predominant pigment while ignoring that of other minor pigments, and few studies have focused on the composition of these pigments. Using the pheomelanin-based plumage in two swallow species, we studied the allocation of two pigments (the predominant pigment, pheomelanin, and the minor pigment, eumelanin) in relation to physiological properties and viability in populations under a natural and sexual selection.
View Article and Find Full Text PDFPheomelanin-based plumage pigmentation has been suggested to be an honest signal of individual quality to conspecifics. It has been hypothesized that oxidative stress is an important agent linking pheomelanic pigmentation to individual quality. Using the Asian barn swallow Hirundo rustica gutturalis, a wild passerine, we tested whether the pheomelanin pigmentation in the red throat patch of adult males, a sexually selected trait, is associated with the ratio between reduced and oxidized glutathione (RGSH/GSSG) as an indicator of current oxidative balance during the early breeding season.
View Article and Find Full Text PDFThe effect of sexual selection on extinction risk remains unclear. In theory, sexual selection can lead to both increase and decrease extinction probability depending on the ecology of the study system. Thus, combining different groups might obscure patterns that can be found in groups that share similar ecological features.
View Article and Find Full Text PDFMalignant mesothelioma (MM) with rhabdoid features is an MM variant. Fifteen cases have been reported previously, all of which were combined with other types of MM. Herein, we report an autopsy case of pleural MM with monomorphic rhabdoid features.
View Article and Find Full Text PDFRecent experimental studies involving the manipulation of sexual traits have demonstrated that sexual trait expression feeds back to testosterone levels, perhaps via social interactions, reinforcing the linkage between sexual trait expression and testosterone levels during the mating period. However, information on this reinforcement under the natural variation of sexual traits remains limited. Using Japanese barn swallows, Hirundo rustica gutturalis, in which extra-pair paternity is quite rare (< 3%), we studied the relationship between plasma testosterone level and a male sexual trait, throat patch size, during the mating and incubation periods.
View Article and Find Full Text PDFA classic example of a sexually selected trait, the deep fork tail of the barn swallow Hirundo rustica is now claimed to have evolved and be maintained mainly via aerodynamic advantage rather than sexually selected advantage. However, this aerodynamic advantage hypothesis does not clarify which flight habits select for/against deep fork tails, causing diversity of tail fork depth in hirundines. Here, by focusing on the genus Hirundo, we investigated whether the large variation in tail fork depth could be explained by the differential flight habits.
View Article and Find Full Text PDFThe number of children with Metabolic Syndrome (MetS) has recently been increasing in Japan. Few studies have investigated the relationship between MetS and oral health. The aim of this study was to investigate the association between MetS, lifestyle, and oral health status in school children.
View Article and Find Full Text PDFBackground And Objective: The reliability of CT assessment of regional bronchodilation is not universally accepted. In this study, using our proprietary 3D-CT software, we first examined airway inner luminal area (Ai) before and after inhalation of SFC in a group of COPD patients and then evaluated the same parameters for two sets of CT data obtained from clinically stable subjects with no intervention.
Methods: We conducted CT at deep inspiration and pulmonary function tests before and one week after inhalation of SFC in 23 COPD patients.
Introduction: Urbanization can considerably impact animal ecology, evolution, and behavior. Among the new conditions that animals experience in cities is anthropogenic noise, which can limit the sound space available for animals to communicate using acoustic signals. Some urban bird species increase their song frequencies so that they can be heard above low-frequency background city noise.
View Article and Find Full Text PDFBackground: Although airway luminal area (Ai) is affected by lung volume (LV), how is not precisely understood. We hypothesized that the effect of LV on Ai would differ by airway generation, lung lobe, and chronic obstructive pulmonary disease (COPD) severity.
Methods: Sixty-seven subjects (15 at risk, 18, 20, and 14 for COPD stages 1, 2, and 3) underwent pulmonary function tests and computed tomography scans at full inspiration and expiration (at functional residual capacity).
Intersexual selection results from several processes, such as differential allocation and differential access, in addition to mating skews by mate choice. These processes can contribute to the evolution, maintenance, and geographic differentiation of male ornamentation, although the importance of these processes in male ornamentation remains poorly understood. The Asian barn swallow Hirundo rustica gutturalis is a socially monogamous songbird that exhibits biparental care and has red throat patches twice as large as those of the nominate H.
View Article and Find Full Text PDFRationale: Although the rate of annual decline in FEV1 is one of the most important outcome measures in chronic obstructive pulmonary disease (COPD), little is known about intersubject variability based on clinical phenotypes.
Objectives: To examine the intersubject variability in a 5-year observational cohort study, particularly focusing on emphysema severity.
Methods: A total of 279 eligible patients with COPD (stages I-IV: 26, 45, 24, and 5%) participated.
Background: Previous studies have shown that polymorphisms in the β2-adrenergic receptor gene (ADRB2) may influence bronchodilator response (BDR) to both β2-agonists and anticholinergics, possibly by intracellular cross-talk, but in opposite ways, in the Japanese population. We hypothesized that the preferential response to either class of bronchodilators might be determined by ADRB2 polymorphisms in patients with chronic obstructive pulmonary disease (COPD).
Objective: To examine the association of ADRB2 polymorphisms and preferential BDR to β2-agonists and anticholinergics in patients with COPD.
Background: Few studies have directly compared airway remodelling assessed by computed tomography (CT) between asthma and chronic obstructive pulmonary disease (COPD). The present study was conducted to determine whether there are any differences between the two diseases with similar levels of airflow limitation under clinically stable conditions.
Methods: Subjects included older male asthmatic patients (n = 19) showing FEV(1)/FVC <70% with smoking history less than 5-pack/year.
Background: Computed tomography (CT) has been used for non-invasive quantitative assessment of airway dimensions, potentially showing airway remodeling, in asthma. However, most studies have examined either only one airway or only airways in anatomically unidentified cross-sections. Using software capable of precisely identifying the generation of airways and measuring airway dimensions perpendicular to the long axis of airways, we examined, in older patients with stable asthma, how inter-subject variation in airway dimensions correlated among the 3rd to 6th generation of airways, and then examined relationships between airway dimensions of each generation and indices of airflow limitation.
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