Powered fight in birds is reliant on feathers forming an aerodynamic surface that resists air pressures.Many basic aspects of feather functionality are unknown,which hampers our understanding of wing function in birds...Powered fight in birds is reliant on feathers forming an aerodynamic surface that resists air pressures.Many basic aspects of feather functionality are unknown,which hampers our understanding of wing function in birds.This study measured the dimensions of primary and secondaryfight feathers of 19 species of parrots.The maximum force the feathers could withstand from below was also measured to mimic the pressuresexperienced during a downstroke.The analysis tested whether:(1)feather dimensions differed along the wing and among secondary and primary remiges;(2)the force that feathers could withstand varied among the remiges;and(3)there would be isometric relationships with bodymass for feather characteristics.The results show that body mass signifcantly affected vane width,rachis thickness,maximum force,and ultimate bending moment,but the relationship for feather length only approached signifcance.Many of the proximal secondary feathers showedsignifcantly lower values relative to the frst primary,whereas for distal primaries the values were greater.There were isometric relationships forforce measurements of primary and secondary feathers with body mass,but there was positive allometry for feather lengths and vane widths.The forces feathers can withstand vary along the wing may be a proxy for the aerodynamic properties of the feathers in situ.Broader taxonomicstudies that explore these topics are required for other species representing a range of different orders.A better understanding of the functionality of feathers will improve our understanding of how avian fight works particularly considering the variety in fight style and wing shape in birds.展开更多
Nests are important structures for birds to raise their offspring and for signaling.Many birds incorporate feathers into the nest,since feathers were traditionally thought to serve the function of insulation.Hypothese...Nests are important structures for birds to raise their offspring and for signaling.Many birds incorporate feathers into the nest,since feathers were traditionally thought to serve the function of insulation.Hypotheses in recent years have considered that some birds place feathers in conspicuous locations in the nest for decoration to trigger a fear response in the competitors.In this study,we investigated whether decorative feathers could deter nest usurpation by Crested Mynas(Acridotheres cristatellus)by manipulating nest box contents.The results revealed that Crested Mynas preferred black feathers to white feathers as decorations and occupied nest boxes decorated with black feathers significantly less than those decorated with white feathers,suggesting that black decorative feathers in the nest could be more effective in preventing nest usurpation by Crested Mynas and that white decorative feathers may have other functions.The black feathers in the nest are prominently placed at the edge of the nest to convey the message that“this nest is occupied”or“the owner of this nest has been preyed upon”to visitor Crested Mynas,thus effectively preventing them from usurping the nest at a later stage.展开更多
Background: Feathers are a defining feature of birds with multiple functions such as flight, insulation, protection against predation and signaling. Feathers are lost during the annual molt while the rate of such loss...Background: Feathers are a defining feature of birds with multiple functions such as flight, insulation, protection against predation and signaling. Feathers are lost during the annual molt while the rate of such loss at other times of the year and its fitness consequences remain poorly known.Methods: I used information on the number and the mass of feathers for 160 individuals belonging to 85 species of birds in general linear mixed models to analyze allometry of feathers and to investigate possible factors explaining variation in the number of feathers. A phylogenetic effect was assessed by quantifying the random effect of genus.Results: The total mass of feathers increased isometrically with body mass, while the total number of feathers and the mean mass of feathers showed negative allometry. Negative allometry implied that small-sized species had relatively many small feathers. There was a negative association between the number of feathers and migration distance. The total number of feathers initially increased during fall and winter, consistent with individuals growing more feathers later during the year or with individuals with fewer feathers selectively disappearing from the population. In contrast, the number of feathers decreased from winter through spring and summer.Conclusions: These findings suggest that thermoregulation has affected the evolution of the number and the size of feathers, there is selection against feather loss, and that the number of feathers varies across seasons.展开更多
A new human infection with an animal flu virus has touched a raw nerve among the public and posed a challenge to China＇s disease control system, which is quickly responding to a possible outbreak by drawing on their ...A new human infection with an animal flu virus has touched a raw nerve among the public and posed a challenge to China＇s disease control system, which is quickly responding to a possible outbreak by drawing on their experiences with previous epidemics.展开更多
Because of the constant challenge to preserve the environment and the search for new materials, a comparative study was carried out using keratin fiber, a fibrous protein, found in the chicken feathers. Five different...Because of the constant challenge to preserve the environment and the search for new materials, a comparative study was carried out using keratin fiber, a fibrous protein, found in the chicken feathers. Five different samples of the feather were analyzed by Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD). First in their natural form Keratin Fiber (KF);the second treated with sodium hydroxide (KFNaOH);the third and fourth samples were semi carbonized at 220℃ in an oven without atmospheric control for 24 hours (samples obtained: Clear brown (SCFC) and Dark brown (SCFD));and the fifth sample was carbonized by pyrolysis Carbonized Feathers (CF). The SEM result shows that the KF has a hollow structure, with knots and hooks. The KFNaOH structure presented rougher than that of the KF, but lost their hooks. The SCFC and SCFD presented brittle structures, but preserved the hollow structure of KF;however, it was only noticeable to a magnification of 3000 times. On the other hand, the CF, was shiny, black, and showed a higher amount of porosity with open micro-pores and micro-tubes, preserved the hollow structure of KF than any other samples studied, and also presented well-defined closed micro-tubes. From the XRD analysis of the KF, CF, KFNaOH, SCFC and SCFD, presented semi-crystalline structures, with the following indices of crystallinity, 20.09%, 18.93%, 17.97%, 15.02% and 14.31%, respectively. The CF presented smaller size crystallites, in between the micro- particulates, around 27 nm and the KFNaOH with larger size around 74 nm. From this study it was concluded that micro-porous carbon material from chicken feathers (KF) could be efficiently obtained through pyrolysis.展开更多
Bird feathers sustain bending and vibrations during flight.Such unwanted vibrations could potentially cause noise and flight instabilities.Damping could alter the system response,resulting in improving quiet flight,st...Bird feathers sustain bending and vibrations during flight.Such unwanted vibrations could potentially cause noise and flight instabilities.Damping could alter the system response,resulting in improving quiet flight,stability,and controllability.Vanes of feathers are known to be indispensable for supporting the aerodynamic function of the wings.The relationship between the hierarchical structures of vanes and the mechanical properties of the feather has been previously studied.However,still little is known about their relationship with feathers’damping properties.Here,the role of vanes in feathers’damping properties was quantified.The vibrations of the feathers with vanes and the bare shaft without vanes after step deflections in the plane of the vanes and perpendicular to it were measured using high-speed video recording.The presence of several main natural vibration modes was observed in the feathers with vanes.After trimming vanes,more vibration modes were observed,the fundamental frequencies increased by 51-70%,and the damping ratio decreased by 38-60%.Therefore,we suggest that vanes largely increase feather damping properties.Damping mechanisms based on the morphology of feather vanes are discussed.The aerodynamic damping is connected with the planar vane surface,the structural damping is related to the interlocking between barbules and barbs,and the material damping is caused by the foamy medulla inside barbs.展开更多
Two growth experiments with fast growing meat type chickens (Ross 308) were conducted to assess the growth of feathers and feather-free body dependent on age and gender (male:female ratio = 1:1). Birds were reared und...Two growth experiments with fast growing meat type chickens (Ross 308) were conducted to assess the growth of feathers and feather-free body dependent on age and gender (male:female ratio = 1:1). Birds were reared under uniform management and feeding conditions (floor pens;15 pens per gender;5 birds per pen) during the starter (day 1 to 22) and grower period (day 22 to 36). Diets were based on corn, wheat, soybean meal, soybean protein concentrate and balanced with feed amino acids to ensure an equal feed protein quality close to the ideal amino acid ratio by a constant mixture of the feed proteins. At start of the experiment and further on weekly up to the end of the 5th week, 15 birds per gender (each 3 pens of 5 birds) were selected and 24 h fasted before quantitative de-feathering. Both feather and feather free body fractions were significantly increased with increasing age of the birds (p < 0.001). Feather percentage as related to the empty body weight increased non-linearly from approximately 2% at the end of the first week to about 4% at the end of the experiment. Feather percentage and dry matter content of the feather-free body was significantly higher in female birds (p < 0.001) as compared to males. Further investigations will show how this varying proportions impact on nutrient deposition of modern meat-type chickens dependent on age and gender, respectively.展开更多
Valorizing chicken feather agro-wastes nowadays is imperative, if these wastes are disposed of without treatment, they could contribute to environmental problems. Conventional methods of processing chicken feathers su...Valorizing chicken feather agro-wastes nowadays is imperative, if these wastes are disposed of without treatment, they could contribute to environmental problems. Conventional methods of processing chicken feathers such as landfilling, chemical treatment and burning are costly, non-time consumable and are toxic to the environment. Microbial hydrolysis, on the contrary, is now considered the main environmental-friendly recycling alternative. Hence, the aim of this study is to isolate keratinolytic bacteria with efficient feather hydrolysis, to optimize some of the physical parameters that could affect both bacterial growth and consequently its degrading ability. Results demonstrated an efficient feather degrading ability of newly identified <i>Bacillus</i> sp. D4 strain isolated from chicken feathers under optimal mesophilic temperature 37°C, pH 8.0 and 10<sup>6</sup> CFU/mL cell size inoculum, interpreted by highest keratin activity (55.0 ± 1.35 U/mL) and (54.3 ± 1.5 U/mL) respectively and higher total protein content in the cell free supernatant of 0.65 mg/mL. Beyond these parameters values, a moderate enzyme activity was observed at 40°C (35.1 ± 2 U/mL), 25°C (30.1 ± 2 U/mL), similarly at the initial pH 7.5 (52.3 ± 2 U/mL), pH 9.0 (49.0 ± 1.2 U/mL) and pH 10.0 (38.2 ± 1.35 U/mL). <i>Bacillus</i> sp. D4, on the other hand, was not able to tolerate high alkaline pH value 11.0 nor acidic pH 4.0 and 5.0 and high temperature of 55°C, correspondingly low enzyme activity was noted (19.0 ± 1 U/mL).展开更多
The purpose was to test the feasibility of preparing cast films directly from an aqueous suspension of alkaline pretreated and fine milled chicken feathers, and to evaluate the impact of different additives on film fo...The purpose was to test the feasibility of preparing cast films directly from an aqueous suspension of alkaline pretreated and fine milled chicken feathers, and to evaluate the impact of different additives on film formation and the tensile properties of the resulting films. The feather suspension consisted of stiff and sharp-pointed fibers together with more round-shaped fines. Films cast from this suspension were opaque and porous. While films without additives were fragile with drying-induced defects, film formation was improved with additives, especially with ethanolamine and maleic acid at 20% and 30% concentrations. A synergistic plasticizing effect was observed with ethanolamine and formamide, and strength of the films was improved with sodium alginate. However, the overall impact of additives on the tensile properties in general and strain at break in specific was limited. This was likely due to the dominating role of the porous film structure and the stiff fibers with a limited reactivity towards the additives.展开更多
Feathers are critical for the flight of birds.A feather comprises a rachis and two rows of barbs on each side of the rachis[1,2].Each side of the barbs features a row of barbules.In extant flying birds,the ventral sid...Feathers are critical for the flight of birds.A feather comprises a rachis and two rows of barbs on each side of the rachis[1,2].Each side of the barbs features a row of barbules.In extant flying birds,the ventral side of the distal half of the distal barbule bears several hook-like structures called hooklets,while the dorsal side of the proximal barbule curves into a narrow groove,creating a specialized interlocking hook-and-groove mechanism that resists tearing force from the air during flight[[2],[3],[4]].展开更多
Over the last 20 years, compression fossils of feathers surrounding dinosaurs have greatly expanded our understanding of the origin and evolution of feathers. One of the most peculiar feather morphotypes discovered to...Over the last 20 years, compression fossils of feathers surrounding dinosaurs have greatly expanded our understanding of the origin and evolution of feathers. One of the most peculiar feather morphotypes discovered to date are rachis dominated feathers(RDFs), which have also been referred to as proximally ribbon-like pennaceous feathers(PRPFs). These elongate feathers are only found in the tail plumage, typically occurring in pairs with both streamer(not proximally ribbon-like) and racket-plume morphologies recognized. Here we describe a large sample set of isolated and paired RDFs from Upper Cretaceous Burmese amber(～ 99 Ma). Amber preserves the finest details of these fragile structures in three dimensions, demonstrating that RDFs form a distinct feather morphotype with a ventrally open rachis, and with significant variability in pigmentation, microstructure, and symmetry.展开更多
Hair and feathers are composed of keratin and are indigestible, inalimental and unpalatable for carnivores. However, carnivores often ingest hair and feathers during feeding or when grooming. We hypothesized tha...Hair and feathers are composed of keratin and are indigestible, inalimental and unpalatable for carnivores. However, carnivores often ingest hair and feathers during feeding or when grooming. We hypothesized that ingestion of hair and feathers changes species diversity and relative abundance of bacteria in the gut of carnivores. To test this hypothesis, we added disinfected poultry down feathers to the normal diet of captive Arctic foxes (Alopex lagopus). We then used fluorescently labeled terminal restriction fragments (T-RFs) to examine changes in fecal bacterial diversity and abundance. The results showed that the number of bacterial species increased significantly after feather ingestion, but that total abundance was unchanged. This demonstrated that addition of disinfected feathers to the diet stimulated increased production among less abundant bacteria, resulting in a balancing of relative abundance of different bacterial species, or that some newly-ingested microbial species would colonize the gut because a suitable microhabitat had become available. This implies that the overall production of bacterial metabolites would be made up of a greater range of substances after feather ingestion. On one hand, the host’s immune response would be more diverse, increasing the capacity of the immune system to regulate gut microflora. On the other hand, the animal’s physiological performance would also be affected. For wild animals, such altered physiological traits would be subjected to natural selection, and, hence, persistent geographic differences in the character of ingested feathers or fur would drive speciation.展开更多
Taking a widely contaminated yet abundant waste,such as poultry feathers,and extracting keratin from this struc-ture appears to be a real challenge whenever the preservation of the secondary structure of the protein i...Taking a widely contaminated yet abundant waste,such as poultry feathers,and extracting keratin from this struc-ture appears to be a real challenge whenever the preservation of the secondary structure of the protein is desired.This process would allow exploiting it in ways(e.g.,in the biomedicalfield)that are inspired by a structure that is primarily designed forflight,therefore capable specifically of withstandingflexure and lateral buckling,also with very low thicknesses.The preservation of the structure is based on disulfide crosslinks,and it is offered with pre-ference by some chemical treatments,mainly those based on ionic liquid and on a reduction process.However,the degree of preservation cannot always be precisely assessed;however,beyond chemical characterization,the forma-tion of homogeneous gels can also suggest that the process was successful in this sense.An extraction respectful of nature’s intentions,considering that the secondary structure builds up according to the very function of the feath-ers in the animal,can be deemed to be biomimetic.In particular,biomimetic extractions comply with the very characteristics the protein was designed for to serve in the specific environmental and mechanical situation in which it is inserted.This review tries to elucidate in which cases this aim is achieved and for which specific appli-cations a chicken feather keratin that has preserved its secondary structure can be suited.展开更多
Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are kn...Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.展开更多
The number of secondary feathers varies among orders of birds with some orders exhibiting a positive relationship with ulna length,whereas in other orders secondary number is invariant.This difference has implications...The number of secondary feathers varies among orders of birds with some orders exhibiting a positive relationship with ulna length,whereas in other orders secondary number is invariant.This difference has implications for scaling of the width of the feather vane within orders.In those species where the number of secondary remiges is invariant with ulna length,vane width should scale isometrically with ulna size to maintain an aerodynamic flight surface.Where feather count increases with increasing ulna length then vane width should exhibit negative allometry.Vane length should also correlate with ulna length,irrespective of the number of feathers.Data were compiled from an online library of images for the vane length and the width of the vane at 50%of the vane length for the fifth secondary feather for 209 bird species from 24 different orders.The results supported the hypotheses that vane width is a function of ulna size,and the number of secondary feathers as associated with different orders.Vane length was unaffected by the number of secondaries but varied between orders.The results suggest that birds have solved the problem of maintaining the aerodynamic surface of the proximal wing in two ways.Hence as ulna length increases the first solution involves more feathers that exhibit negative allometry for vane width,or in the second where feather count doesn't change,the vane width simply scales isometrically.The implications for the mechanical properties of the vane,and how it affects wing function,have not yet been explored in a range of birds.展开更多
Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-cano...Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-canopy lichen(Cladonia spp.)woodlands have been observed in boreal forests of eastern Canada.It has been hypothesized that high severity of fires would be the cause of this change,but this is difficult to validate a posteriori on mature forest stands.Because charcoal properties are affected by fire severity,we have put forward the hypothesis that the amount and physicochemical properties of charcoal(C,N,H,O,ash,surface area)would be different and indicative of a greater fire severity for open-canopy forests compared to closed canopy ones.Our hypothesis was partly validated in that the amount of charcoal found on the ground of closed-canopy forests was greater than that of open-canopy forests.However,the physicochemical properties were not different,albeit a greater variability of charcoal properties for open canopy stands.These results do not allow us to fully validate or reject our hypothesis on the role of fire severity in the shift between open and closed canopy stands.However,they suggest that the variability in fire conditions as well as the amounts of charcoal produced are different between the two ecosystem types.Furthermore,considering the role that biochar may play in improving soil conditions and promoting vegetation restoration,our results suggest that charcoal may play a role in maintaining these two stable alternative ecosystem states.展开更多
Background Poor feather growth not only affects the appearance of the organism but also decreases the feed efficiency.Methionine(Met)is an essential amino acid required for feather follicle development;yet the exact m...Background Poor feather growth not only affects the appearance of the organism but also decreases the feed efficiency.Methionine(Met)is an essential amino acid required for feather follicle development;yet the exact mechanism involved remains insufficiently understood.Methods A total of 1801-day-old broilers were selected and randomly divided into 3 treatments:control group(0.45%Met),Met-deficiency group(0.25%Met),and Met-rescue group(0.45%Met in the pre-trial period and 0.25%Met in the post-trial period).The experimental period lasted for 56 d,with a pre-trial period of 1–28 d and a post-trial period of 29–56 d.In addition,Met-deficiency and Met-rescue models were constructed in feather follicle epidermal stem cell by controlling the supply of Met in the culture medium.Results Dietary Met-deficiency significantly(P<0.05)reduced the ADG,ADFI and F/G,and inhibited feather follicle development.Met supplementation significantly(P<0.05)improved growth performance and the feather growth in broilers.Met-rescue may promote feather growth in broilers by activating the Wnt/β-catenin signaling pathway(GSK-3β,CK1,Axin1,β-catenin,Activeβ-catenin,TCF4,and Cyclin D1).Compared with Met-deficiency group,Met-rescue significantly(P<0.05)increased the activity of feather follicle epidermal stem cell and mitochondrial membrane potential,activated Wnt/β-catenin signaling pathway,and decreased the content of reactive oxygen species(P<0.05).CO-IP confirmed that mitochondrial protein PGAM5 interacted with Axin1,the scaffold protein of the disruption complex of the Wnt/β-catenin signaling pathway,and directly mediated Met regulation of Wnt/β-catenin signaling pathway and feather follicle development.Conclusions PGAM5 binding to Axin1 mediates the regulation of Wnt/β-catenin signaling pathway,and promotes feather follicle development and feather growth of broiler chickens through Met supplementation.These results provide theoretical support for the improvement of economic value and production efficiency of broiler chickens.展开更多
A duxianqin musician needs only a single string stretched across an elongated(细长的)soundboard and a feather⁃shaped rod to deliver a diverse repertoire,whether pop or classical,Chinese or Western.In his Zen⁃style stu...A duxianqin musician needs only a single string stretched across an elongated(细长的)soundboard and a feather⁃shaped rod to deliver a diverse repertoire,whether pop or classical,Chinese or Western.In his Zen⁃style studio adorned with folding screens,Wei Qingbing,39,sits on a bamboo mat and plucks(弹拨)the string of his duxianqin with his right hand,while his left hand slides across the rod to adjust the pitch and add vibrato.展开更多
Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH...Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH transcription factor 1(Sim1)gene,postulated to act as a cis-regulatory element governing flight feather morphogenesis.To investigate its functional significance,genome-edited(GE)primordial germ cell(PGC)lines carrying targeted ASHCE deletions were generated using CRISPR/Cas9-mediated editing,with germline chimeric males subsequently mated with wild-type(WT)hens to obtain GE progeny.The resulting GE chickens harbored 257-260 bp deletions,excising approximately half of the Sim1-ASHCE sequence.Reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR)analysis showed an average 0.32-fold reduction in Sim1 expression in the forelimbs of GE embryos at day 8(E8)compared to WT counterparts.Despite this,GE chickens developed structurally normal flight and tail feathers.In situ hybridization localized Sim1 expression to the posterior mesenchyme surrounding flight feather buds in E8 WT embryos,but not within the buds themselves.These results suggest that partial deletion of Sim1-ASHCE,despite diminishing Sim1 expression,does not disrupt flight feather formation.The excised region appears to possess enhancer activity toward Sim1 but is dispensable for flight feather development.Complete ablation of the ASHCE will be necessary to fully resolve the regulatory role of Sim1 in avian feather morphogenesis.展开更多
[Objective]This study aimed to explore the inheritance pattem of feather color in hybrid offspring of Texan pigeon and American Silver King pigeon, so as to provide a theoretical basis for the breeding of feather colo...[Objective]This study aimed to explore the inheritance pattem of feather color in hybrid offspring of Texan pigeon and American Silver King pigeon, so as to provide a theoretical basis for the breeding of feather color auto-sexing strains. [Method]The segregation situation of feather color in the male and female offspring of Texan pigeon （♂）×American Silver King pigeon （♀）（TKYW） and American Silver King pigeon （♂） ×Texan pigeon （♀） （YWTK） was analyzed. [Result]The feather color of TKYW offspring was all slate gray. Among the offspring of YWTK, the feather color of the males was all slate gray, while the feather color of the females was all silver gray; and the ratio between different colors was 1：1 （P 〉 0.05）. The F1 generation of YWTK was subjected to selfing, and the feather color of the male and female F2 generation was analyzed. It was found that the ratio of silver gray （male） to slate gray （male） to silver gray （female） to slate gray （female） was 1：1：1：1 （P 〉 0.05）. On the basis of the above results, it could be preliminarily predicated that the feather color control genes of Texan pigeon are Z^BZB and Z^BW and those of American Silver King pigeon are Z^bZ^b and Z^bW. There is a cumulative effect on B which is dominant for b. [Conclusion] This study will better solve the problem of male and female identification of pigeon in the early period.展开更多
文摘Powered fight in birds is reliant on feathers forming an aerodynamic surface that resists air pressures.Many basic aspects of feather functionality are unknown,which hampers our understanding of wing function in birds.This study measured the dimensions of primary and secondaryfight feathers of 19 species of parrots.The maximum force the feathers could withstand from below was also measured to mimic the pressuresexperienced during a downstroke.The analysis tested whether:(1)feather dimensions differed along the wing and among secondary and primary remiges;(2)the force that feathers could withstand varied among the remiges;and(3)there would be isometric relationships with bodymass for feather characteristics.The results show that body mass signifcantly affected vane width,rachis thickness,maximum force,and ultimate bending moment,but the relationship for feather length only approached signifcance.Many of the proximal secondary feathers showedsignifcantly lower values relative to the frst primary,whereas for distal primaries the values were greater.There were isometric relationships forforce measurements of primary and secondary feathers with body mass,but there was positive allometry for feather lengths and vane widths.The forces feathers can withstand vary along the wing may be a proxy for the aerodynamic properties of the feathers in situ.Broader taxonomicstudies that explore these topics are required for other species representing a range of different orders.A better understanding of the functionality of feathers will improve our understanding of how avian fight works particularly considering the variety in fight style and wing shape in birds.
基金supported by the National Natural Science Foundation of China(No.31970427 and 32270526 granted to W.L.).
文摘Nests are important structures for birds to raise their offspring and for signaling.Many birds incorporate feathers into the nest,since feathers were traditionally thought to serve the function of insulation.Hypotheses in recent years have considered that some birds place feathers in conspicuous locations in the nest for decoration to trigger a fear response in the competitors.In this study,we investigated whether decorative feathers could deter nest usurpation by Crested Mynas(Acridotheres cristatellus)by manipulating nest box contents.The results revealed that Crested Mynas preferred black feathers to white feathers as decorations and occupied nest boxes decorated with black feathers significantly less than those decorated with white feathers,suggesting that black decorative feathers in the nest could be more effective in preventing nest usurpation by Crested Mynas and that white decorative feathers may have other functions.The black feathers in the nest are prominently placed at the edge of the nest to convey the message that“this nest is occupied”or“the owner of this nest has been preyed upon”to visitor Crested Mynas,thus effectively preventing them from usurping the nest at a later stage.
文摘Background: Feathers are a defining feature of birds with multiple functions such as flight, insulation, protection against predation and signaling. Feathers are lost during the annual molt while the rate of such loss at other times of the year and its fitness consequences remain poorly known.Methods: I used information on the number and the mass of feathers for 160 individuals belonging to 85 species of birds in general linear mixed models to analyze allometry of feathers and to investigate possible factors explaining variation in the number of feathers. A phylogenetic effect was assessed by quantifying the random effect of genus.Results: The total mass of feathers increased isometrically with body mass, while the total number of feathers and the mean mass of feathers showed negative allometry. Negative allometry implied that small-sized species had relatively many small feathers. There was a negative association between the number of feathers and migration distance. The total number of feathers initially increased during fall and winter, consistent with individuals growing more feathers later during the year or with individuals with fewer feathers selectively disappearing from the population. In contrast, the number of feathers decreased from winter through spring and summer.Conclusions: These findings suggest that thermoregulation has affected the evolution of the number and the size of feathers, there is selection against feather loss, and that the number of feathers varies across seasons.
文摘A new human infection with an animal flu virus has touched a raw nerve among the public and posed a challenge to China＇s disease control system, which is quickly responding to a possible outbreak by drawing on their experiences with previous epidemics.
文摘Because of the constant challenge to preserve the environment and the search for new materials, a comparative study was carried out using keratin fiber, a fibrous protein, found in the chicken feathers. Five different samples of the feather were analyzed by Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD). First in their natural form Keratin Fiber (KF);the second treated with sodium hydroxide (KFNaOH);the third and fourth samples were semi carbonized at 220℃ in an oven without atmospheric control for 24 hours (samples obtained: Clear brown (SCFC) and Dark brown (SCFD));and the fifth sample was carbonized by pyrolysis Carbonized Feathers (CF). The SEM result shows that the KF has a hollow structure, with knots and hooks. The KFNaOH structure presented rougher than that of the KF, but lost their hooks. The SCFC and SCFD presented brittle structures, but preserved the hollow structure of KF;however, it was only noticeable to a magnification of 3000 times. On the other hand, the CF, was shiny, black, and showed a higher amount of porosity with open micro-pores and micro-tubes, preserved the hollow structure of KF than any other samples studied, and also presented well-defined closed micro-tubes. From the XRD analysis of the KF, CF, KFNaOH, SCFC and SCFD, presented semi-crystalline structures, with the following indices of crystallinity, 20.09%, 18.93%, 17.97%, 15.02% and 14.31%, respectively. The CF presented smaller size crystallites, in between the micro- particulates, around 27 nm and the KFNaOH with larger size around 74 nm. From this study it was concluded that micro-porous carbon material from chicken feathers (KF) could be efficiently obtained through pyrolysis.
基金financially supported by Sino-German Center for Research Promotion (Grant no.GZ1154).
文摘Bird feathers sustain bending and vibrations during flight.Such unwanted vibrations could potentially cause noise and flight instabilities.Damping could alter the system response,resulting in improving quiet flight,stability,and controllability.Vanes of feathers are known to be indispensable for supporting the aerodynamic function of the wings.The relationship between the hierarchical structures of vanes and the mechanical properties of the feather has been previously studied.However,still little is known about their relationship with feathers’damping properties.Here,the role of vanes in feathers’damping properties was quantified.The vibrations of the feathers with vanes and the bare shaft without vanes after step deflections in the plane of the vanes and perpendicular to it were measured using high-speed video recording.The presence of several main natural vibration modes was observed in the feathers with vanes.After trimming vanes,more vibration modes were observed,the fundamental frequencies increased by 51-70%,and the damping ratio decreased by 38-60%.Therefore,we suggest that vanes largely increase feather damping properties.Damping mechanisms based on the morphology of feather vanes are discussed.The aerodynamic damping is connected with the planar vane surface,the structural damping is related to the interlocking between barbules and barbs,and the material damping is caused by the foamy medulla inside barbs.
文摘Two growth experiments with fast growing meat type chickens (Ross 308) were conducted to assess the growth of feathers and feather-free body dependent on age and gender (male:female ratio = 1:1). Birds were reared under uniform management and feeding conditions (floor pens;15 pens per gender;5 birds per pen) during the starter (day 1 to 22) and grower period (day 22 to 36). Diets were based on corn, wheat, soybean meal, soybean protein concentrate and balanced with feed amino acids to ensure an equal feed protein quality close to the ideal amino acid ratio by a constant mixture of the feed proteins. At start of the experiment and further on weekly up to the end of the 5th week, 15 birds per gender (each 3 pens of 5 birds) were selected and 24 h fasted before quantitative de-feathering. Both feather and feather free body fractions were significantly increased with increasing age of the birds (p < 0.001). Feather percentage as related to the empty body weight increased non-linearly from approximately 2% at the end of the first week to about 4% at the end of the experiment. Feather percentage and dry matter content of the feather-free body was significantly higher in female birds (p < 0.001) as compared to males. Further investigations will show how this varying proportions impact on nutrient deposition of modern meat-type chickens dependent on age and gender, respectively.
文摘Valorizing chicken feather agro-wastes nowadays is imperative, if these wastes are disposed of without treatment, they could contribute to environmental problems. Conventional methods of processing chicken feathers such as landfilling, chemical treatment and burning are costly, non-time consumable and are toxic to the environment. Microbial hydrolysis, on the contrary, is now considered the main environmental-friendly recycling alternative. Hence, the aim of this study is to isolate keratinolytic bacteria with efficient feather hydrolysis, to optimize some of the physical parameters that could affect both bacterial growth and consequently its degrading ability. Results demonstrated an efficient feather degrading ability of newly identified <i>Bacillus</i> sp. D4 strain isolated from chicken feathers under optimal mesophilic temperature 37°C, pH 8.0 and 10<sup>6</sup> CFU/mL cell size inoculum, interpreted by highest keratin activity (55.0 ± 1.35 U/mL) and (54.3 ± 1.5 U/mL) respectively and higher total protein content in the cell free supernatant of 0.65 mg/mL. Beyond these parameters values, a moderate enzyme activity was observed at 40°C (35.1 ± 2 U/mL), 25°C (30.1 ± 2 U/mL), similarly at the initial pH 7.5 (52.3 ± 2 U/mL), pH 9.0 (49.0 ± 1.2 U/mL) and pH 10.0 (38.2 ± 1.35 U/mL). <i>Bacillus</i> sp. D4, on the other hand, was not able to tolerate high alkaline pH value 11.0 nor acidic pH 4.0 and 5.0 and high temperature of 55°C, correspondingly low enzyme activity was noted (19.0 ± 1 U/mL).
基金supported by KaRMA2020 projectthe European Union’s Horizon 2020 Research and Innovation program under Grant Agreement n°723268.
文摘The purpose was to test the feasibility of preparing cast films directly from an aqueous suspension of alkaline pretreated and fine milled chicken feathers, and to evaluate the impact of different additives on film formation and the tensile properties of the resulting films. The feather suspension consisted of stiff and sharp-pointed fibers together with more round-shaped fines. Films cast from this suspension were opaque and porous. While films without additives were fragile with drying-induced defects, film formation was improved with additives, especially with ethanolamine and maleic acid at 20% and 30% concentrations. A synergistic plasticizing effect was observed with ethanolamine and formamide, and strength of the films was improved with sodium alginate. However, the overall impact of additives on the tensile properties in general and strain at break in specific was limited. This was likely due to the dominating role of the porous film structure and the stiff fibers with a limited reactivity towards the additives.
基金supported by the National Natural Science Foundation of China(32400364,42202025,42288201,42072030,and 42302020)the China Postdoctoral Science Foundation(E41ZJ51135)+7 种基金the BJAST Young Scholar Programs(24CE-YS-01)the special financial support of the Beijing Governmentthe National Key R&D Program of China(2022YFC2601200)the Fundamental Research Funds for the Liaoning Universities(LJ202410166028)the National Science&Technology Fundamental Resources Investigation Program of China(2022FY100500 and 2023FY100301)the Institute of Zoology,Chinese Academy of Sciences(2023IOZ0104)the State Key Laboratory of Animal Biodiversity Conservation and Integrated Pest Management(SKLA2502)the Survey of Wildlife Resources in Key Areas of Xizang(ZL202203601).
文摘Feathers are critical for the flight of birds.A feather comprises a rachis and two rows of barbs on each side of the rachis[1,2].Each side of the barbs features a row of barbules.In extant flying birds,the ventral side of the distal half of the distal barbule bears several hook-like structures called hooklets,while the dorsal side of the proximal barbule curves into a narrow groove,creating a specialized interlocking hook-and-groove mechanism that resists tearing force from the air during flight[[2],[3],[4]].
基金National Natural Science Foundation of China(41772008)Fundamental Research Funds for the Central Universities(2652017215)+2 种基金National Geographic Society,U.S.A.(EC0768-15)Natural Sciences and Engineering Research Council,Canada(2015-00681)RSM and Paul Riegert scholarships(to P.C.)for support
文摘Over the last 20 years, compression fossils of feathers surrounding dinosaurs have greatly expanded our understanding of the origin and evolution of feathers. One of the most peculiar feather morphotypes discovered to date are rachis dominated feathers(RDFs), which have also been referred to as proximally ribbon-like pennaceous feathers(PRPFs). These elongate feathers are only found in the tail plumage, typically occurring in pairs with both streamer(not proximally ribbon-like) and racket-plume morphologies recognized. Here we describe a large sample set of isolated and paired RDFs from Upper Cretaceous Burmese amber(～ 99 Ma). Amber preserves the finest details of these fragile structures in three dimensions, demonstrating that RDFs form a distinct feather morphotype with a ventrally open rachis, and with significant variability in pigmentation, microstructure, and symmetry.
文摘Hair and feathers are composed of keratin and are indigestible, inalimental and unpalatable for carnivores. However, carnivores often ingest hair and feathers during feeding or when grooming. We hypothesized that ingestion of hair and feathers changes species diversity and relative abundance of bacteria in the gut of carnivores. To test this hypothesis, we added disinfected poultry down feathers to the normal diet of captive Arctic foxes (Alopex lagopus). We then used fluorescently labeled terminal restriction fragments (T-RFs) to examine changes in fecal bacterial diversity and abundance. The results showed that the number of bacterial species increased significantly after feather ingestion, but that total abundance was unchanged. This demonstrated that addition of disinfected feathers to the diet stimulated increased production among less abundant bacteria, resulting in a balancing of relative abundance of different bacterial species, or that some newly-ingested microbial species would colonize the gut because a suitable microhabitat had become available. This implies that the overall production of bacterial metabolites would be made up of a greater range of substances after feather ingestion. On one hand, the host’s immune response would be more diverse, increasing the capacity of the immune system to regulate gut microflora. On the other hand, the animal’s physiological performance would also be affected. For wild animals, such altered physiological traits would be subjected to natural selection, and, hence, persistent geographic differences in the character of ingested feathers or fur would drive speciation.
文摘Taking a widely contaminated yet abundant waste,such as poultry feathers,and extracting keratin from this struc-ture appears to be a real challenge whenever the preservation of the secondary structure of the protein is desired.This process would allow exploiting it in ways(e.g.,in the biomedicalfield)that are inspired by a structure that is primarily designed forflight,therefore capable specifically of withstandingflexure and lateral buckling,also with very low thicknesses.The preservation of the structure is based on disulfide crosslinks,and it is offered with pre-ference by some chemical treatments,mainly those based on ionic liquid and on a reduction process.However,the degree of preservation cannot always be precisely assessed;however,beyond chemical characterization,the forma-tion of homogeneous gels can also suggest that the process was successful in this sense.An extraction respectful of nature’s intentions,considering that the secondary structure builds up according to the very function of the feath-ers in the animal,can be deemed to be biomimetic.In particular,biomimetic extractions comply with the very characteristics the protein was designed for to serve in the specific environmental and mechanical situation in which it is inserted.This review tries to elucidate in which cases this aim is achieved and for which specific appli-cations a chicken feather keratin that has preserved its secondary structure can be suited.
基金supported by the Science and Technology Development Program of Jilin Province(No.20240101122JC)and(No.20240101143JC)the Key Scientific and Technological Research and Development Projects of Jilin Provincial Science and Technology Department(Grant Number 20230201108GX)。
文摘Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.
文摘The number of secondary feathers varies among orders of birds with some orders exhibiting a positive relationship with ulna length,whereas in other orders secondary number is invariant.This difference has implications for scaling of the width of the feather vane within orders.In those species where the number of secondary remiges is invariant with ulna length,vane width should scale isometrically with ulna size to maintain an aerodynamic flight surface.Where feather count increases with increasing ulna length then vane width should exhibit negative allometry.Vane length should also correlate with ulna length,irrespective of the number of feathers.Data were compiled from an online library of images for the vane length and the width of the vane at 50%of the vane length for the fifth secondary feather for 209 bird species from 24 different orders.The results supported the hypotheses that vane width is a function of ulna size,and the number of secondary feathers as associated with different orders.Vane length was unaffected by the number of secondaries but varied between orders.The results suggest that birds have solved the problem of maintaining the aerodynamic surface of the proximal wing in two ways.Hence as ulna length increases the first solution involves more feathers that exhibit negative allometry for vane width,or in the second where feather count doesn't change,the vane width simply scales isometrically.The implications for the mechanical properties of the vane,and how it affects wing function,have not yet been explored in a range of birds.
基金supported by the MITACS Accelerate grant with Greenfirst,industry partner in La Sarre,QC,Canada.
文摘Fire disturbances are increasing under global climate change and ecological transformations of forests are occurring.Specifically,shifts from productive closed-canopy feather moss forests to low-productivity open-canopy lichen(Cladonia spp.)woodlands have been observed in boreal forests of eastern Canada.It has been hypothesized that high severity of fires would be the cause of this change,but this is difficult to validate a posteriori on mature forest stands.Because charcoal properties are affected by fire severity,we have put forward the hypothesis that the amount and physicochemical properties of charcoal(C,N,H,O,ash,surface area)would be different and indicative of a greater fire severity for open-canopy forests compared to closed canopy ones.Our hypothesis was partly validated in that the amount of charcoal found on the ground of closed-canopy forests was greater than that of open-canopy forests.However,the physicochemical properties were not different,albeit a greater variability of charcoal properties for open canopy stands.These results do not allow us to fully validate or reject our hypothesis on the role of fire severity in the shift between open and closed canopy stands.However,they suggest that the variability in fire conditions as well as the amounts of charcoal produced are different between the two ecosystem types.Furthermore,considering the role that biochar may play in improving soil conditions and promoting vegetation restoration,our results suggest that charcoal may play a role in maintaining these two stable alternative ecosystem states.
基金supported by the National Natural Science Foundation of China(32372902)Guangdong Special Support Program for Young Talents(NYQN2024007)。
文摘Background Poor feather growth not only affects the appearance of the organism but also decreases the feed efficiency.Methionine(Met)is an essential amino acid required for feather follicle development;yet the exact mechanism involved remains insufficiently understood.Methods A total of 1801-day-old broilers were selected and randomly divided into 3 treatments:control group(0.45%Met),Met-deficiency group(0.25%Met),and Met-rescue group(0.45%Met in the pre-trial period and 0.25%Met in the post-trial period).The experimental period lasted for 56 d,with a pre-trial period of 1–28 d and a post-trial period of 29–56 d.In addition,Met-deficiency and Met-rescue models were constructed in feather follicle epidermal stem cell by controlling the supply of Met in the culture medium.Results Dietary Met-deficiency significantly(P<0.05)reduced the ADG,ADFI and F/G,and inhibited feather follicle development.Met supplementation significantly(P<0.05)improved growth performance and the feather growth in broilers.Met-rescue may promote feather growth in broilers by activating the Wnt/β-catenin signaling pathway(GSK-3β,CK1,Axin1,β-catenin,Activeβ-catenin,TCF4,and Cyclin D1).Compared with Met-deficiency group,Met-rescue significantly(P<0.05)increased the activity of feather follicle epidermal stem cell and mitochondrial membrane potential,activated Wnt/β-catenin signaling pathway,and decreased the content of reactive oxygen species(P<0.05).CO-IP confirmed that mitochondrial protein PGAM5 interacted with Axin1,the scaffold protein of the disruption complex of the Wnt/β-catenin signaling pathway,and directly mediated Met regulation of Wnt/β-catenin signaling pathway and feather follicle development.Conclusions PGAM5 binding to Axin1 mediates the regulation of Wnt/β-catenin signaling pathway,and promotes feather follicle development and feather growth of broiler chickens through Met supplementation.These results provide theoretical support for the improvement of economic value and production efficiency of broiler chickens.
文摘A duxianqin musician needs only a single string stretched across an elongated(细长的)soundboard and a feather⁃shaped rod to deliver a diverse repertoire,whether pop or classical,Chinese or Western.In his Zen⁃style studio adorned with folding screens,Wei Qingbing,39,sits on a bamboo mat and plucks(弹拨)the string of his duxianqin with his right hand,while his left hand slides across the rod to adjust the pitch and add vibrato.
基金supported by the Ministry of Agriculture and Rural Affairs of the People's Republic of China(125A0607)Department of Science and Technology of Yunnan Province(XDYC-KJLJ-2022-0004)。
文摘Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH transcription factor 1(Sim1)gene,postulated to act as a cis-regulatory element governing flight feather morphogenesis.To investigate its functional significance,genome-edited(GE)primordial germ cell(PGC)lines carrying targeted ASHCE deletions were generated using CRISPR/Cas9-mediated editing,with germline chimeric males subsequently mated with wild-type(WT)hens to obtain GE progeny.The resulting GE chickens harbored 257-260 bp deletions,excising approximately half of the Sim1-ASHCE sequence.Reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR)analysis showed an average 0.32-fold reduction in Sim1 expression in the forelimbs of GE embryos at day 8(E8)compared to WT counterparts.Despite this,GE chickens developed structurally normal flight and tail feathers.In situ hybridization localized Sim1 expression to the posterior mesenchyme surrounding flight feather buds in E8 WT embryos,but not within the buds themselves.These results suggest that partial deletion of Sim1-ASHCE,despite diminishing Sim1 expression,does not disrupt flight feather formation.The excised region appears to possess enhancer activity toward Sim1 but is dispensable for flight feather development.Complete ablation of the ASHCE will be necessary to fully resolve the regulatory role of Sim1 in avian feather morphogenesis.
基金Supported by Key Research and Development Program of Jiangsu Province(Modern Agriculture)(BE2017348)~~
文摘[Objective]This study aimed to explore the inheritance pattem of feather color in hybrid offspring of Texan pigeon and American Silver King pigeon, so as to provide a theoretical basis for the breeding of feather color auto-sexing strains. [Method]The segregation situation of feather color in the male and female offspring of Texan pigeon （♂）×American Silver King pigeon （♀）（TKYW） and American Silver King pigeon （♂） ×Texan pigeon （♀） （YWTK） was analyzed. [Result]The feather color of TKYW offspring was all slate gray. Among the offspring of YWTK, the feather color of the males was all slate gray, while the feather color of the females was all silver gray; and the ratio between different colors was 1：1 （P 〉 0.05）. The F1 generation of YWTK was subjected to selfing, and the feather color of the male and female F2 generation was analyzed. It was found that the ratio of silver gray （male） to slate gray （male） to silver gray （female） to slate gray （female） was 1：1：1：1 （P 〉 0.05）. On the basis of the above results, it could be preliminarily predicated that the feather color control genes of Texan pigeon are Z^BZB and Z^BW and those of American Silver King pigeon are Z^bZ^b and Z^bW. There is a cumulative effect on B which is dominant for b. [Conclusion] This study will better solve the problem of male and female identification of pigeon in the early period.
