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Sexually dimorphic plumage coloration is widespread in birds in which the male plumage is brighter than the female. This phenomenon is related to the environmental constraints on sexual selection or intraspecific competition between males and females in birds. The physiological factors and genetic regulation mechanism affecting the color of sexual dimorphism plumages in birds have always attracted significant attention in research. Understanding the diversity of sexually dimorphic traits provides insights into the mating strategies of the sexes and their behavior, ecology, and evolution. Interestingly, the ASIP, MC1R, TYRP1, and BCO2 genes have been identified to play a potential role in the coloration of melanin and carotenoids in bird sexual dimorphism plumages, either by controlling the rate and type of melanin or carotene synthesis or degradation by exerting an effect on the pigment biosynthetic pathway. In this review, we systematically summarize the biological significance, the direct causes (chemical and physical color), and the influence of sex hormones in sexually dimorphic plumage coloration. We also investigate the molecular mechanism underlying the roles of some genes on sexual dimorphism coloration, thereby providing a reference for in-depth understanding on the formation mechanism(s) of sexual dimorphic coloration in birds.鸟类羽毛颜色普遍存在性别二态性,即雄性羽色相对于雌性更鲜艳,这种现象的产生可能与环境对性别的选择效应或性别间的种内竞争有关。鸟类羽毛颜色性别二态性的生理因素及遗传调控机制一直备受关注。了解两性二态性特征的形成机制,有助于深入了解两性的交配策略及种群的行为和进化过程。研究表明,ASIP、MC1R、TYRP1和BCO2等基因能调控鸟类羽色性别二态性的形成,主要通过控制黑色素或胡萝卜素产生或降解的速率和类型,或通过调控色素生物合成途径。本文综述了影响鸟类羽色性别二态性的生物学意义、直接原因(化学性颜色、物理性颜色)、性激素对鸟类羽色性别二态性的影响,以及部分关键基因调控鸟类羽色性别二态性形成的分子机制,以期为深入理解鸟类羽色性别二态性的形成机制研究提供参考。.

In poultry, feed restriction is common feeding management to limit poultry nutrients intake so that poultry only intake the essential energy, meeting the basic need of growth and development. Our study investigated whether feeding restriction affects the diversity of the intestinal microbiota of growing breeding ducks. In this research, the 60-120-day-old ducks were raised in restricted and free-feeding groups. After slaughtering, the carcass traits and the cecal contents were collected for 16S rRNA sequencing analysis. After feeding restriction, the growth rate of ducks was limited, the weight and rate of abdominal fat decreased, and the rate of chest and leg muscles increased. In addition, feeding restriction can also change the diversity of intestinal microorganisms in breeding ducks, such as the increase of Firmicutes abundance and the decrease of Bacteroidetes abundance. After analyzing of correlation, significant correlations between gut microbiota and carcass phenotypes were found. The results indicated that gut microbiota might be involved in the life activities associated with phenotypic changes. This study proved the effect of feeding methods on the intestinal microbiota of ducks, providing a theoretical basis of the microbial angle for raising ducks in a feeding-restricted period.

The composition of microorganisms in the gastrointestinal tract is closely related to the intestinal microenvironments and the exterior growth environments of host. In this study, 16S rDNA sequencing technology was adopted to investigate the influence of fermentation bed on the cecum microorganisms of ducks. Two feeding density treatment groups were set up, including group A (n = 4brids/m

Background Photoplethysmographic imaging (PPGi) that is based on camera allows acquiring photoplethysmogram and measuring physiological parameters such as pulse rate, respiration rate and perfusion level. It has also shown potential for estimation of arterial oxygen saturation (SaO2). However, there are some technical limitations such as optical shunting, different camera sensitivity to different light spectra, different AC-to-DC ratios (the peak-to-peak amplitude to baseline ratio) of the PPGi signal for different portions of the sensor surface area, the low sampling rate and the inconsistency of contact force between the fingertip and camera lens. Methods In this paper, we take full account of the above-mentioned design challenges and present an accurate SaO2 estimation method based on two cameras. The hardware system we used consisted of an FPGA development board (XC6SLX150T-3FGG676 from Xilinx), with connected to it two commercial cameras and an SD card. The two cameras were placed back to back, one camera acquired PPGi signal from the right index fingertip under 660 nm light illumination while the other camera acquired PPGi signal from the thumb fingertip using an 800 nm light illumination. The both PPGi signals were captured simultaneously, recorded in a text file on the SD card and processed offline using MATLAB®. The calculation of SaO2 was based on the principle of pulse oximetry. The AC-to-DC ratio was acquired by the ratio of powers of AC and DC components of the PPGi signal in the time–frequency domain using the smoothed pseudo Wigner–Ville distribution. The calibration curve required for SaO2 measurement was obtained by linear regression analysis. Results The results of our estimation method from 12 subjects showed a high correlation and accuracy with those of conventional pulse oximetry for the range from 90 to 100%. Conclusions Our method is suitable for mobile applications implemented in smartphones, which could allow SaO2 measurement in a pervasive environment.

The development of the follicular wall and apoptosis of corresponding cells are dependent upon the stage of follicle growth and levels of endogenous hormones. However, the development and apoptosis of prehierarchical follicles in geese is insufficiently known. In order to obtain an understanding about the microstructure, development and apoptosis of prehierarchical follicles in geese, firstly, a histological method was used to investigate the morphological structure of prehierarchical follicles. Results showed that the thickness of granulosa cell layers of the follicular wall increased first, then decreased to the lowest when follicles grew to 9-10 mm in diameter, and the theca layers also thinned to the lowest thickness at the same stage. Moreover, the expression of follicle-stimulating hormone receptor (FSHR) mRNA and the enzyme activity of caspase-3 were analyzed and the results showed that the expression of FSHR was highest when follicles grew to 8-9 mm in diameter (p < 0.05); the enzyme activity of caspae-3 was the highest when follicles grew to 6-8 mm in diameter (p < 0.05). These collective findings suggested that follicles 6-10 mm in diameter were especially significant, and perhaps represent a turning point from growing follicles to dominant follicles to be selected into a hierarchical sequence or to other follicles to be degenerated during prehierarchical follicle development.

The confocal micro X-ray fluorescence (XRF) based on polycapillary X-ray lens and conventional X-ray source was used to carry out the scanning analysis of the distribution of the elements in a single hair. The elemental distribution in the single hair was obtained. In the confocal micro XRF technology, the output focal spot of the polycapillary focusing X-ray lens and the input focal spot of the polycapillary parallel X-ray lens were adjusted confocally. The detector could only detect the X-rays from the overlapping foci. This confocal structure decreased the effects of the background on the X-ray spectra, and was accordingly helpful for improving the accuracy of this XRF technology. A polycapillary focusing X-ray lens with a high gain in power density was used to decrease the requirement of power of the X-ray source used in this confocal technology, and made it possible to perform such confocal micro XRF analysis by using the conventional X-ray source with low cost. Experimental results indicated that the confocal micro X-ray fluorescence based on polycapillary X-ray lens had potential applications in analyzing the elemental distribution of individual hairs.

A confocal micro X-ray fluorescence thickness gauge based on a polycapillary focusing X-ray lens, a polycapillary parallel X-ray lens and a laboratory X-ray source was designed in order to analyze nondestructively the thickness of thin film and cladding material. The performances of this confocal thickness gauge were studied. Two Ni films with a thickness of about 25 and 15 microm respectively were measured. The relative errors corresponding to them were 3.5% and 7.1%, respectively. The thickness uniformity of a Ni films with a thickness of about 10 microm was analyzed. This confocal technology for measuring the thickness was both spatially resolved and elemental sensitive, and therefore, it could be used to measure the thickness of the multilayer sample and analyze the thickness uniformity of the sample. This confocal thickness gauge had potential applications in analyzing the thickness of sample.