Fossil evidence for evolution of the shape and color of penguin feathers.

Science.gov (United States)

Clarke, Julia A; Ksepka, Daniel T; Salas-Gismondi, Rodolfo; Altamirano, Ali J; Shawkey, Matthew D; D'Alba, Liliana; Vinther, Jakob; DeVries, Thomas J; Baby, Patrice

2010-11-12

Penguin feathers are highly modified in form and function, but there have been no fossils to inform their evolution. A giant penguin with feathers was recovered from the late Eocene (~36 million years ago) of Peru. The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage. Analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray and reddish-brown. In contrast, the dark black-brown color of extant penguin feathers is generated by large, ellipsoidal melanosomes previously unknown for birds. The nanostructure of penguin feathers was thus modified after earlier macrostructural modifications of feather shape linked to aquatic flight.

Temporal overlap and repeatability of feather corticosterone levels: practical considerations for use as a biomarker.

Science.gov (United States)

Harris, Christopher M; Madliger, Christine L; Love, Oliver P

2016-01-01

The measurement of corticosterone (CORT) levels in feathers has recently become an appealing tool for the conservation toolbox, potentially providing a non-invasive, integrated measure of stress activity throughout the time of feather growth. However, because the mechanism of CORT deposition, storage and stability in feathers is not fully understood, it is unclear how reliable this measure may be, especially when there is an extended interval between growth and feather collection. We compared CORT levels of naturally grown feathers from tree swallows ( Tachycineta bicolor ) that were moulted and regrown concurrently and therefore expected to have similar CORT levels. Specifically, we compared the same feather from the left and right wing (moulted symmetrically) and different types of feathers (wing, back and tail) expected to have been moulted within the same time period. We found that larger, heavier feathers held more CORT per unit length. In addition, we found a lack of concordance in CORT levels both within the same feather type and between different feather types, even after taking into account differences in feather density. Our results indicate that naturally grown feathers may not consistently provide an indication of stress status. Additionally, conflict in results may arise depending on the feather assayed, and total feather volume may be an important consideration when interpreting feather CORT levels. Future work is necessary to determine explicitly the mechanisms of CORT deposition, the effects of environmental exposure and feather wear on the permanence of the feather CORT signal, and the influence of responses to wild stressors on feather CORT levels, before feather CORT can be implemented effectively as a tool for ecological and conservation applications.

Comparison of Taxi Time Prediction Performance Using Different Taxi Speed Decision Trees

Science.gov (United States)

Lee, Hanbong

2017-01-01

In the STBO modeler and tactical surface scheduler for ATD-2 project, taxi speed decision trees are used to calculate the unimpeded taxi times of flights taxiing on the airport surface. The initial taxi speed values in these decision trees did not show good prediction accuracy of taxi times. Using the more recent, reliable surveillance data, new taxi speed values in ramp area and movement area were computed. Before integrating these values into the STBO system, we performed test runs using live data from Charlotte airport, with different taxi speed settings: 1) initial taxi speed values and 2) new ones. Taxi time prediction performance was evaluated by comparing various metrics. The results show that the new taxi speed decision trees can calculate the unimpeded taxi-out times more accurately.

Feathers at nests are potential female signals in the spotless starling.

Science.gov (United States)

Veiga, José P; Polo, Vicente

2005-09-22

Although the presence of feathers in the nest is widespread among birds, it has not been previously suggested that feathers can be used as sexual signals. Females of the spotless starling (Sturnus unicolor) regularly carry feathers to their nest, mostly during laying and incubation. We show that the arrangement of these feathers was non-random with respect to the side (obverse or reverse) placed upwards (which can be viewed from the nest entrance). Feathers of the wood pigeon (Columba palumbus) and the spotless starling, which exhibit higher ultraviolet and visible reflectance on their reverse side, were predominantly placed with this side upwards. On the contrary, feathers of the jay (Garrulus glandarius) were predominantly found exhibiting the obverse side, which possesses higher reflectance in this species. Feathers of the azure-winged magpie (Cyanopica cyana), with similar reflectance values on either side, were placed indiscriminately in obverse and reverse positions. The results suggest that feathers are arranged to maximize their conspicuousness within the nest and hence that they might be potentially used as intraspecific signals.

Quantifying the dynamic wing morphing of hovering hummingbird.

Science.gov (United States)

Maeda, Masateru; Nakata, Toshiyuki; Kitamura, Ikuo; Tanaka, Hiroto; Liu, Hao

2017-09-01

Animal wings are lightweight and flexible; hence, during flapping flight their shapes change. It has been known that such dynamic wing morphing reduces aerodynamic cost in insects, but the consequences in vertebrate flyers, particularly birds, are not well understood. We have developed a method to reconstruct a three-dimensional wing model of a bird from the wing outline and the feather shafts (rachides). The morphological and kinematic parameters can be obtained using the wing model, and the numerical or mechanical simulations may also be carried out. To test the effectiveness of the method, we recorded the hovering flight of a hummingbird ( Amazilia amazilia ) using high-speed cameras and reconstructed the right wing. The wing shape varied substantially within a stroke cycle. Specifically, the maximum and minimum wing areas differed by 18%, presumably due to feather sliding; the wing was bent near the wrist joint, towards the upward direction and opposite to the stroke direction; positive upward camber and the 'washout' twist (monotonic decrease in the angle of incidence from the proximal to distal wing) were observed during both half-strokes; the spanwise distribution of the twist was uniform during downstroke, but an abrupt increase near the wrist joint was found during upstroke.

Flight performance and feather quality: paying the price of overlapping moult and breeding in a tropical highland bird.

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Maria Angela Echeverry-Galvis

Full Text Available A temporal separation of energetically costly life history events like reproduction and maintenance of the integumentary system is thought to be promoted by selection to avoid trade-offs and maximize fitness. It has therefore remained somewhat of a paradox that certain vertebrate species can undergo both events simultaneously. Identifying potential costs of overlapping two demanding life history stages will further our understanding of the selection pressures that shape the temporal regulation of life history events in vertebrates. We studied free-living tropical Slaty brush-finches (Atlapetes schistaceus, in which individuals spontaneously overlap reproduction and moult or undergo both events in separation. To assess possible costs of such an overlap we quantified feather quality and flight performance of individuals in different states. We determined individual's life history state by measuring gonad size and scoring moult stage, and collected a newly grown 7(th primary wing feather for later analysis of feather quality. Finally, we quantified flight performance for each individual in the wild. Overlapping individuals produced lighter and shorter wing feathers than individuals just moulting, with females decreasing feather quality more strongly during the overlap than males. Moreover, overlapping individuals had a reduced flight speed during escape flights, while their foraging flight speed was unaffected. Despite overlappers being larger and having a smaller wing area, their lower body mass resulted in a similar wing load as in breeders or moulters. Individuals measured repeatedly in different states also showed significant decreases in feather quality and escape flight speed during the overlap. Reduced escape flight speed may represent a major consequence of the overlap by increasing predation risk. Our data document costs to undergoing two life history stages simultaneously, which likely arise from energetic trade-offs. Impairments in

Modelling growth curves of Nigerian indigenous normal feather ...

African Journals Online (AJOL)

This study was conducted to predict the growth curve parameters using Bayesian Gompertz and logistic models and also to compare the two growth function in describing the body weight changes across age in Nigerian indigenous normal feather chicken. Each chick was wing-tagged at day old and body weights were ...

Gliding Swifts Attain Laminar Flow over Rough Wings

NARCIS (Netherlands)

Lentink, D.; Kat, de R.

2014-01-01

Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1–2% of chord length on the upper surface—10,000 times rougher than sailplane

Taxis and crowd-taxis: sharing as a private activity and public concern

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Merethe Dotterud Leiren

2016-06-01

Full Text Available The sharing economy has generated interest among economists for its customer focus and potential to enhance competition. However, it has also caused uproar in industries which have felt competitive pressure, for example among the established stakeholders in the taxi industry. While regulations currently impose considerable costs on the taxi industry, they do not cover virtual transport innovations such as Uber. The lack of a level playing field between taxis and such ‘crowd-taxis’ has generated media attention and conflict. Taxi owners worry about decreasing revenues and taxi drivers about poor working conditions. Other concerns are related to poor transport preparedness, accessibility issues, quality assurance and tax evasion. Despite considerable media attention, there has so far been a lack of scholarly literature addressing the consequences of the sharing economy in the transport sector. Focusing on the Norwegian taxi market, we argue that crowd-taxis will likely produce a range of unanticipated effects, necessitating regulation. For example, crowd-taxis may contribute to a loss of transport preparedness in rural areas. The findings are based on first and secondary data and 19 interviews.

Inferring Passenger Denial Behavior of Taxi Drivers from Large-Scale Taxi Traces.

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Sihai Zhang

Full Text Available How to understand individual human actions is a fundamental question to modern science, which drives and incurs many social, technological, racial, religious and economic phenomena. Human dynamics tries to reveal the temporal pattern and internal mechanism of human actions in letter or electronic communications, from the perspective of continuous interactions among friends or acquaintances. For interactions between stranger to stranger, taxi industry provide fruitful phenomina and evidence to investigate the action decisions. In fact, one striking disturbing events commonly reported in taxi industry is passenger refusing or denial, whose reasons vary, including skin color, blind passenger, being a foreigner or too close destination, religion reasons and anti specific nationality, so that complaints about taxi passenger refusing have to be concerned and processed carefully by local governments. But more universal factors for this phenomena are of great significance, which might be fulfilled by big data research to obtain novel insights in this question. In this paper, we demonstrate the big data analytics application in revealing novel insights from massive taxi trace data, which, for the first time, validates the passengers denial in taxi industry and estimates the denial ratio in Beijing city. We first quantify the income differentiation facts among taxi drivers. Then we find out that choosing the drop-off places also contributes to the high income for taxi drivers, compared to the previous explanation of mobility intelligence. Moreover, we propose the pick-up, drop-off and grid diversity concepts and related diversity analysis suggest that, high income taxi drivers will deny passengers in some situations, so as to choose the passengers' destination they prefer. Finally we design an estimation method for denial ratio and infer that high income taxi drivers will deny passengers with 8.52% likelihood in Beijing. Our work exhibits the power of big

Toronto hybrid taxi pilot

International Nuclear Information System (INIS)

Stevens, M.; Marans, B.

2009-10-01

This paper provided details of a hybrid taxi pilot program conducted to compare the on-road performance of Toyota Camry hybrid vehicles against conventional vehicles over a 1-year period in order to determine the business case and air emission reductions associated with the use of hybrid taxi cabs. Over 750,000 km worth of fuel consumption was captured from 10 Toyota Camry hybrids, a Toyota Prius, and 5 non-hybrid Camry vehicles over an 18-month period. The average real world fuel consumption for the taxis demonstrated that the Toyota Prius has the lowest cost of ownership, while the non-hybrid Camry has the highest cost of ownership. Carbon dioxide (CO 2 ) reductions associated with the 10 Camry hybrid taxis were calculated at 236 tonnes over a 7-year taxi service life. Results suggested that the conversion of Toronto's 5680 taxis would yield annual CO 2 emission reductions of over 19,000 tonnes. All hybrid purchasers identified themselves as highly likely to purchase a hybrid again. 5 tabs., 9 figs.

Toronto hybrid taxi pilot

Energy Technology Data Exchange (ETDEWEB)

Stevens, M. [CrossChasm Technologies, Cambridge, ON (Canada); Marans, B. [Toronto Atmospheric Fund, ON (Canada)

2009-10-15

This paper provided details of a hybrid taxi pilot program conducted to compare the on-road performance of Toyota Camry hybrid vehicles against conventional vehicles over a 1-year period in order to determine the business case and air emission reductions associated with the use of hybrid taxi cabs. Over 750,000 km worth of fuel consumption was captured from 10 Toyota Camry hybrids, a Toyota Prius, and 5 non-hybrid Camry vehicles over an 18-month period. The average real world fuel consumption for the taxis demonstrated that the Toyota Prius has the lowest cost of ownership, while the non-hybrid Camry has the highest cost of ownership. Carbon dioxide (CO{sub 2}) reductions associated with the 10 Camry hybrid taxis were calculated at 236 tonnes over a 7-year taxi service life. Results suggested that the conversion of Toronto's 5680 taxis would yield annual CO{sub 2} emission reductions of over 19,000 tonnes. All hybrid purchasers identified themselves as highly likely to purchase a hybrid again. 5 tabs., 9 figs.

Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing.

Science.gov (United States)

Achache, Yonathan; Sapir, Nir; Elimelech, Yossef

2017-08-01

The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle-especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna's hummingbird ( Calypte anna ). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing's leading-edge differs from the attached vorticity structure that was typically found over insects' wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies.

Variation of heavy metals within and among feathers of birds of prey: effects of molt and external contamination

Energy Technology Data Exchange (ETDEWEB)

Dauwe, T.; Bervoets, L.; Pinxten, R.; Blust, R.; Eens, M

2003-08-01

Concentrations of many heavy metals in feathers, except Hg, did not reflect the molting sequence, suggesting external contamination. - In this study we examined the effect of external contamination on the heavy metal (Ag, Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn) concentration in feathers. We compared the heavy metal content among the 10 primary wing feathers of sparrowhawks (Accipiter nisus), little owls (Athene nocta) and barn owls (Tyto alba) and the variation within the outermost tail feather of sparrowhawks and tawny owls (Strix aluco). The concentration of Hg was significantly higher in feathers molted first, suggesting that levels in feathers reflect levels in the blood during formation. For some other elements (Al, Co, Ni, Pb, Zn) on the other hand, there are strong indications that external contamination may have an important impact on the levels detected in the feathers. This should be taken into account in future monitoring studies.

Amino acid neurotoxins in feathers of the Lesser Flamingo, Phoeniconaias minor.

Science.gov (United States)

Metcalf, J S; Banack, S A; Kotut, K; Krienitz, L; Codd, G A

2013-01-01

The Lesser Flamingo (Phoeniconaias minor) is known to use cyanobacteria (primarily Arthrospira) as a major food source in the East African Rift Valley lakes. Periodically, mass mortalities have occurred, associated with the cyanobacterial toxins (cyanotoxins), microcystins and anatoxin-a. Deposition of these cyanotoxins into P. minor feathers has been shown to occur, consistent with the presence of cyanotoxins in the livers, stomach and faecal contents after dietary intake. As cyanobacteria have been shown to also produce the neurotoxins β-N-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB), stored wing feathers, previously recovered from flamingos which had been exposed to microcystins and anatoxin-a and had subsequently died, were analysed for these neurotoxic amino acids. Trace amounts of BMAA were detected in extracts from Lake Nakuru flamingo feathers, with DAB also present at concentrations between 3.5 and 8.5 μg g(-1) dry weight in feathers from both lakes. Toxin recovery by solid-phase extraction of feather digests was tested with spiked deuterated BMAA and showed good recovery when analysed by LC-MS/MS (80-94%). This is the first report of these neurotoxic amino acids in birds. We discuss the origin and significance of DAB, alongside other cyanotoxins of dietary origin, in the feathers of the Lesser Flamingo. Copyright © 2012 Elsevier Ltd. All rights reserved.

Qualitative skeletal correlates of wing shape in extant birds (Aves: Neoaves).

Science.gov (United States)

Hieronymus, Tobin L

2015-02-27

Among living fliers (birds, bats, and insects), birds display relatively high aspect ratios, a dimensionless shape variable that distinguishes long and narrow vs. short and broad wings. Increasing aspect ratio results in a functional tradeoff between low induced drag (efficient cruise) and increased wing inertia (difficult takeoff). Given the wide scope of its functional effects, the pattern of aspect ratio evolution is an important factor that contributes to the substantial ecological and phylogenetic diversity of living birds. However, because the feathers that define the wingtip (and hence wingspan and aspect ratio) often do not fossilize, resolution in the pattern of avian wing shape evolution is obscured by missing information. Here I use a comparative approach to investigate the relationship between skeletal proxies of flight feather attachment and wing shape. An accessory lobe of the internal index process of digit II-1, a bony correlate of distal primary attachment, shows weak but statistically significant relationships to aspect ratio and mass independent of other skeletal morphology. The dorsal phalangeal fossae of digit II-1, which house distal primaries VIII and IX, also show a trend of increased prominence with higher aspect ratio. Quill knobs on the ulna are examined concurrently, but do not show consistent signal with respect to wing shape. Although quill knobs are cited as skeletal correlates of flight performance in birds, their relationship to wing shape is inconsistent among extant taxa, and may reflect diverging selection pressures acting on a conserved architecture. In contrast, correlates of distal primary feather attachment on the major digit show convergent responses to increasing aspect ratio. In light of the diversity of musculoskeletal and integumentary mophology that underlies wing shape in different avian clades, it is unlikely that a single skeletal feature will show consistent predictive power across Neoaves. Confident inference of

Relative feather mass indices: are feather masses needed to ...

African Journals Online (AJOL)

Relative feather mass indices: are feather masses needed to estimate the percentage of new feather mass grown for moult regression models? ... As an alternative, it is here tested if feather mass indices may be sufficient replacements for species-specific feather masses. Thirty-five species of birds with known primary ...

Soft-tissue and dermal arrangement in the wing of an Early Cretaceous bird: Implications for the evolution of avian flight

Science.gov (United States)

Navalón, Guillermo; Marugán-Lobón, Jesús; Chiappe, Luis M.; Luis Sanz, José; Buscalioni, Ángela D.

2015-01-01

Despite a wealth of fossils of Mesozoic birds revealing evidence of plumage and other soft-tissue structures, the epidermal and dermal anatomy of their wing’s patagia remain largely unknown. We describe a distal forelimb of an enantiornithine bird from the Lower Cretaceous limestones of Las Hoyas, Spain, which reveals the overall morphology of the integument of the wing and other connective structures associated with the insertion of flight feathers. The integumentary anatomy, and myological and arthrological organization of the new fossil is remarkably similar to that of modern birds, in which a system of small muscles, tendons and ligaments attaches to the follicles of the remigial feathers and maintains the functional integrity of the wing during flight. The new fossil documents the oldest known occurrence of connective tissues in association with the flight feathers of birds. Furthermore, the presence of an essentially modern connective arrangement in the wing of enantiornithines supports the interpretation of these primitive birds as competent fliers. PMID:26440221

Methods for determining unimpeded aircraft taxiing time and evaluating airport taxiing performance

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Yu Zhang

2017-04-01

Full Text Available The objective of this study is to improve the methods of determining unimpeded (nominal taxiing time, which is the reference time used for estimating taxiing delay, a widely accepted performance indicator of airport surface movement. After reviewing existing methods used widely by different air navigation service providers (ANSP, new methods relying on computer software and statistical tools, and econometrics regression models are proposed. Regression models are highly recommended because they require less detailed data and can serve the needs of general performance analysis of airport surface operations. The proposed econometrics model outperforms existing ones by introducing more explanatory variables, especially taking aircraft passing and over-passing into the considering of queue length calculation and including runway configuration, ground delay program, and weather factors. The length of the aircraft queue in the taxiway system and the interaction between queues are major contributors to long taxi-out times. The proposed method provides a consistent and more accurate method of calculating taxiing delay and it can be used for ATM-related performance analysis and international comparison.

Performance and Heterosis of Indigenous Chicken Crossbreed (Naked Neck x Frizzled Feather In The Humid Tropics

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Jeremiah Monday Nwenya

2017-12-01

Full Text Available Forty-four (44 birds (about 50 weeks old male and female inbred naked necked and frizzle feathered chickens were crossed to generate F1 crossbred chicken that were used to evaluate the performance and heterosis effects. Data taken on 180 chicks (97 NN and 83 FF day-old chick weight (BWT0, body weight (BWT, daily average feed intake (AFI, feed conversion ratio (FCR, brooding and rearing mortalities, linear body measurements (LBM: body length, wing length, keel length, shank length and breast width were used to estimate heterosis and performance of F1 progenies. Results of the experiment showed positive heterosis with significant differences among the F1 progenies over their parents in body weight, average feed intake and feed conversion ratio. The reciprocal cross (i.e. frizzle feather rooster x naked neck hen showed a significant improvement in their performances genetically, explaining that better results are achieved through crossbreeding of these indigenous breeds. With reference to their body linear parameters, the reciprocal cross of naked neck and frizzle feathered chickens developed higher body length, whereas the main crosses performed better in their wing length, keel length, shank length and body width respectively, mainly after 8 weeks suggesting that earlier performance was attributable to maternal influences.

Haste makes waste but condition matters: molt rate-feather quality trade-off in a sedentary songbird.

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Csongor I Vágási

Full Text Available The trade-off between current and residual reproductive values is central to life history theory, although the possible mechanisms underlying this trade-off are largely unknown. The 'molt constraint' hypothesis suggests that molt and plumage functionality are compromised by the preceding breeding event, yet this candidate mechanism remains insufficiently explored.The seasonal change in photoperiod was manipulated to accelerate the molt rate. This treatment simulates the case of naturally late-breeding birds. House sparrows Passer domesticus experiencing accelerated molt developed shorter flight feathers with more fault bars and body feathers with supposedly lower insulation capacity (i.e. shorter, smaller, with a higher barbule density and fewer plumulaceous barbs. However, the wing, tail and primary feather lengths were shorter in fast-molting birds if they had an inferior body condition, which has been largely overlooked in previous studies. The rachis width of flight feathers was not affected by the treatment, but it was still condition-dependent.This study shows that sedentary birds might face evolutionary costs because of the molt rate-feather quality conflict. This is the first study to experimentally demonstrate that (1 molt rate affects several aspects of body feathers as well as flight feathers and (2 the costly effects of rapid molt are condition-specific. We conclude that molt rate and its association with feather quality might be a major mediator of life history trade-offs. Our findings also suggest a novel advantage of early breeding, i.e. the facilitation of slower molt and the condition-dependent regulation of feather growth.

Haste Makes Waste but Condition Matters: Molt Rate–Feather Quality Trade-Off in a Sedentary Songbird

Science.gov (United States)

Vágási, Csongor I.; Pap, Péter L.; Vincze, Orsolya; Benkő, Zoltán; Marton, Attila; Barta, Zoltán

2012-01-01

Background The trade-off between current and residual reproductive values is central to life history theory, although the possible mechanisms underlying this trade-off are largely unknown. The ‘molt constraint’ hypothesis suggests that molt and plumage functionality are compromised by the preceding breeding event, yet this candidate mechanism remains insufficiently explored. Methodology/Principal Findings The seasonal change in photoperiod was manipulated to accelerate the molt rate. This treatment simulates the case of naturally late-breeding birds. House sparrows Passer domesticus experiencing accelerated molt developed shorter flight feathers with more fault bars and body feathers with supposedly lower insulation capacity (i.e. shorter, smaller, with a higher barbule density and fewer plumulaceous barbs). However, the wing, tail and primary feather lengths were shorter in fast-molting birds if they had an inferior body condition, which has been largely overlooked in previous studies. The rachis width of flight feathers was not affected by the treatment, but it was still condition-dependent. Conclusions/Significance This study shows that sedentary birds might face evolutionary costs because of the molt rate–feather quality conflict. This is the first study to experimentally demonstrate that (1) molt rate affects several aspects of body feathers as well as flight feathers and (2) the costly effects of rapid molt are condition-specific. We conclude that molt rate and its association with feather quality might be a major mediator of life history trade-offs. Our findings also suggest a novel advantage of early breeding, i.e. the facilitation of slower molt and the condition-dependent regulation of feather growth. PMID:22808221

Progress of primary feather molt of adult mourning doves in Missouri

Science.gov (United States)

Sadler, K.C.; Tomlinson, R.E.; Wight, H.M.

1970-01-01

The examination of 7,892 adult doves in Missouri between 1953 and 1965 showed that less than 2.5% of adult doves completed their molt before October 1. Adult doves of both sexes began molting their primary feathers during early June in Missouri and lost the last (tenth) primary during the latter half of October. Approximately 140-150 days were required to complete the molt. Thus, early-hatched immatures, which begin their primary molt 25-30 days after hatching, contributed the bulk of the wings with completed molts in September. By correctly classifying September samples of dove wings with a completed molt as young-of-the-year a more accurate young:adult ratio is obtained.

Complex coevolution of wing, tail, and vocal sounds of courting male bee hummingbirds.

Science.gov (United States)

Clark, Christopher J; McGuire, Jimmy A; Bonaccorso, Elisa; Berv, Jacob S; Prum, Richard O

2018-03-01

Phenotypic characters with a complex physical basis may have a correspondingly complex evolutionary history. Males in the "bee" hummingbird clade court females with sound from tail-feathers, which flutter during display dives. On a phylogeny of 35 species, flutter sound frequency evolves as a gradual, continuous character on most branches. But on at least six internal branches fall two types of major, saltational changes: mode of flutter changes, or the feather that is the sound source changes, causing frequency to jump from one discrete value to another. In addition to their tail "instruments," males also court females with sound from their syrinx and wing feathers, and may transfer or switch instruments over evolutionary time. In support of this, we found a negative phylogenetic correlation between presence of wing trills and singing. We hypothesize this transference occurs because wing trills and vocal songs serve similar functions and are thus redundant. There are also three independent origins of self-convergence of multiple signals, in which the same species produces both a vocal (sung) frequency sweep, and a highly similar nonvocal sound. Moreover, production of vocal, learned song has been lost repeatedly. Male bee hummingbirds court females with a diverse, coevolving array of acoustic traits. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

Automation of Taxiing

Directory of Open Access Journals (Sweden)

Jaroslav Bursík

2017-01-01

Full Text Available The article focuses on the possibility of automation of taxiing, which is the part of a flight, which, under adverse weather conditions, greatly reduces the operational usability of an airport, and is the only part of a flight that has not been affected by automation, yet. Taxiing is currently handled manually by the pilot, who controls the airplane based on information from visual perception. The article primarily deals with possible ways of obtaining navigational information, and its automatic transfer to the controls. Analyzed wand assessed were currently available technologies such as computer vision, Light Detection and Ranging and Global Navigation Satellite System, which are useful for navigation and their general implementation into an airplane was designed. Obstacles to the implementation were identified, too. The result is a proposed combination of systems along with their installation into airplane’s systems so that it is possible to use the automated taxiing.

The application of algorithm in taxi security system

Science.gov (United States)

Luo, Chengyu

2017-08-01

With the booming of the society and economy today, Taxis and private cars have gradually become one of the most popular tools in transportation for their low price and convenience. However, because of the breakdown in the security system, a few accidents occurred due to the illegal taxi. The unreliable security management has attributed to the lack of trust in taxi companies and relevant regulatory authorities, which considered to be the reason why people are worried about it. Accordingly, we put forward a design for a taxi security system, making use of modern technology such as NFC, iBeacon, GPS combined with algorithms, automatically recognize the taxi we take, and reflecting basic information of taxi and driver on our mobile phone.

Modeling taxi driver anticipatory behavior

NARCIS (Netherlands)

Zheng, Zhong; Rasouli, S.; Timmermans, H.J.P.

2018-01-01

As part of a wider behavioral agent-based model that simulates taxi drivers’ dynamic passenger-finding behavior under uncertainty, we present a model of strategic behavior of taxi drivers in anticipation of substantial time varying demand at locations such as airports and major train stations. The

A Study on Optimal Resource Allocation of Taxis

Directory of Open Access Journals (Sweden)

Lv Xiao Peng

2016-01-01

Full Text Available As taxis play an increasingly important role in urban traffic system, the research on the supply and demand of taxis and the design of an optimal model of taxis supply has an importantly practical significance. In this paper, we used the traffic bureau data of Guangzhou, and determined the rate of empty driving as the index to establish the model. Nonlinear programming method was uesd to establish the optimal model of taxis quantity to meet the maximum income and maximum passenger satisfaction. Finally we got the optimal number of taxis was 37537.59

The morphogenesis of feathers.

Science.gov (United States)

Yu, Mingke; Wu, Ping; Widelitz, Randall B; Chuong, Cheng-Ming

2002-11-21

Feathers are highly ordered, hierarchical branched structures that confer birds with the ability of flight. Discoveries of fossilized dinosaurs in China bearing 'feather-like' structures have prompted interest in the origin and evolution of feathers. However, there is uncertainty about whether the irregularly branched integumentary fibres on dinosaurs such as Sinornithosaurus are truly feathers, and whether an integumentary appendage with a major central shaft and notched edges is a non-avian feather or a proto-feather. Here, we use a developmental approach to analyse molecular mechanisms in feather-branching morphogenesis. We have used the replication-competent avian sarcoma retrovirus to deliver exogenous genes to regenerating flight feather follicles of chickens. We show that the antagonistic balance between noggin and bone morphogenetic protein 4 (BMP4) has a critical role in feather branching, with BMP4 promoting rachis formation and barb fusion, and noggin enhancing rachis and barb branching. Furthermore, we show that sonic hedgehog (Shh) is essential for inducing apoptosis of the marginal plate epithelia, which results in spaces between barbs. Our analyses identify the molecular pathways underlying the topological transformation of feathers from cylindrical epithelia to the hierarchical branched structures, and provide insights on the possible developmental mechanisms in the evolution of feather forms.

Soluble proteins from fowl feather keratin. II. Isolation of some proteins from barbs.

Science.gov (United States)

Murayama, K; Akahane, K; Murozono, S

1977-01-01

Four fractions, GF-1, 2, 3, and 4, which had been separated from S-carboxymethylated (SCM-) proteins of fowl feathers by gel filtration, were each chromatographed on a DEAE-cellulose column in 0.05 M Tris-HCl buffer (pH 8.5) containing 8 M urea. The major fraction, GF-3, was further separated into seven peaks; the first four were shown to be single components by polyacrylamide disc gel electrophoresis. Chromatograms of GF-1 and 2 showed broad peaks which appeared at nearly the same volume as in GF-3. The components from GF-3 had very similar amino acid compositions except that the SCM-cysteine content showed a tendency to increase in the order of elution from the column. SCM-extract prepared from barbs of the wing feathers of a fowl was more heterogeneous than that taken from the body feathers. A combination of gel filtration on Sephadex G-75 and chromatography on DEAE-cellulose was found to be more effective for the isolation of soluble SCM-proteins.

Unzipping bird feathers.

Science.gov (United States)

Kovalev, Alexander; Filippov, Alexander E; Gorb, Stanislav N

2014-03-06

The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understanding mechanics of the entire feather structure. This study was undertaken to estimate the separation force of single hooklets and their arrays using force measurement of an unzipping feather vane. The hooklets usually separate in some number synchronously (20 on average) with the highest observed separation force of 1.74 mN (average force 0.27 mN), whereas the single hooklet separation force was 14 μN. A simple numerical model was suggested for a better understanding of zipping and unzipping behaviour in feathers. The model demonstrates features similar to those observed in experiments.

Using an alternate light source to detect electrically singed feathers and hair in a forensic setting.

Science.gov (United States)

Viner, Tabitha C; Kagan, Rebecca A; Johnson, Jennifer L

2014-01-01

Mortality due to electrical injury in wildlife may occur in the form of lightning strike or power line contact. Evidence of electrical contact may be grossly obvious, with extensive singeing, curling, and blackening of feathers, fur, or skin. Occasionally, changes may be subtle, owing to lower current or reduced conductivity, making a definitive diagnosis of electrocution more difficult. We describe the use of an alternate light source in the examination of cases of lightning strike and power line contact in wildlife, and the enhanced detection of changes due to electrical currents in the hair and feathers of affected animals. Subtle changes in the wing feathers of 12 snow geese and 1 wolf that were struck by separate lightning events were made obvious by the use of an alternate light source. Similarly, this technique can be used to strengthen the evidence for power line exposure in birds. Published by Elsevier Ireland Ltd.

Energy Taxis Is the Dominant Behavior in Azospirillum brasilense

Science.gov (United States)

Alexandre, Gladys; Greer, Suzanne E.; Zhulin, Igor B.

2000-01-01

Energy taxis encompasses aerotaxis, phototaxis, redox taxis, taxis to alternative electron acceptors, and chemotaxis to oxidizable substrates. The signal for this type of behavior is originated within the electron transport system. Energy taxis was demonstrated, as a part of an overall behavior, in several microbial species, but it did not appear as the dominant determinant in any of them. In this study, we show that most behavioral responses proceed through this mechanism in the alpha-proteobacterium Azospirillum brasilense. First, chemotaxis to most chemoeffectors typical of the azospirilla habitat was found to be metabolism dependent and required a functional electron transport system. Second, other energy-related responses, such as aerotaxis, redox taxis, and taxis to alternative electron acceptors, were found in A. brasilense. Finally, a mutant lacking a cytochrome c oxidase of the cbb3 type was affected in chemotaxis, redox taxis, and aerotaxis. Altogether, the results indicate that behavioral responses to most stimuli in A. brasilense are triggered by changes in the electron transport system. PMID:11029423

Impact of feathers and feather follicles on broiler carcass bacteria.

Science.gov (United States)

Cason, J A; Hinton, A; Buhr, R J

2004-08-01

Genetically featherless and feathered broiler siblings were used to test the contribution of feathers and feather follicles to the numbers of aerobic bacteria, Escherichia coli, and Campylobacter in whole-carcass rinse samples taken immediately after carcasses were defeathered for 30 or 60 s. Numbers of spoilage bacteria were counted after the same fully processed carcasses were stored for 1 wk at 2 degrees C. In each of 3 replications, twenty-eight 11-wk-old, mixed-sex, genetically featherless or feathered broilers were processed in a laboratory processing facility. Immediately after individual defeathering in a mechanical picker, carcasses were sampled using a carcass rinse technique. Carcasses were eviscerated, immersion chilled at 2 degrees C for 30 min, individually bagged, and stored for 1 wk at 2 degrees C, after which all carcasses were rinsed again, and spoilage bacteria in the rinsate were enumerated. There were no significant differences (P defeathering and no differences between carcasses picked for 30 or 60 s. There were no differences in numbers of spoilage bacteria after 1 wk of refrigeration for any of the feather presence-picking length combinations. Although the defeathering step in poultry processing has been identified as an opportunity for bacterial contamination from the intestinal tract and cross-contamination between carcasses, the presence of feathers and feather follicles does not make a significant difference in carcass bacterial contamination immediately after defeathering or in spoilage bacteria after 1 wk of refrigeration.

Validating the use of intrinsic markers in body feathers to identify inter-individual differences in non-breeding areas of northern fulmars.

Science.gov (United States)

Quinn, Lucy R; Meharg, Andrew A; van Franeker, Jan A; Graham, Isla M; Thompson, Paul M

Many wildlife studies use chemical analyses to explore spatio-temporal variation in diet, migratory patterns and contaminant exposure. Intrinsic markers are particularly valuable for studying non-breeding marine predators, when direct methods of investigation are rarely feasible. However, any inferences regarding foraging ecology are dependent upon the time scale over which tissues such as feathers are formed. In this study, we validate the use of body feathers for studying non-breeding foraging patterns in a pelagic seabird, the northern fulmar. Analysis of carcasses of successfully breeding adult fulmars indicated that body feathers moulted between September and March, whereas analyses of carcasses and activity patterns suggested that wing feather and tail feather moult occurred during more restricted periods (September to October and September to January, respectively). By randomly sampling relevant body feathers, average values for individual birds were shown to be consistent. We also integrated chemical analyses of body feather with geolocation tracking data to demonstrate that analyses of δ 13 C and δ 15 N values successfully assigned 88 % of birds to one of two broad wintering regions used by breeding adult fulmars from a Scottish study colony. These data provide strong support for the use of body feathers as a tool for exploring non-breeding foraging patterns and diet in wide-ranging, pelagic seabirds.

Exploring Urban Taxi Drivers’ Activity Distribution Based on GPS Data

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Xiaowei Hu

2014-01-01

Full Text Available With the rapid development of information communication technology and data mining technology, we can obtain taxi vehicle’s real time operation status through the large-scale taxi GPS trajectories data and explore the drivers’ activity distribution characteristics. Based on the 204 continuous hours of 3198 taxi vehicles’ operation data of Shenzhen, China, this paper analyzed the urban taxi driver’s activity distribution characteristics from different temporal and spatial levels. In the time level, we identified the difference with taxi daily operation pattern (weekday versus weekends, continuous time in one day, passengers in vehicle time, and taxi drivers’ operation frequency; in the space level, we explored the taxi driver’s searching pattern, including searching activity space distribution and the relationship between the pick-up locations and the drop-off locations. This research can be helpful for urban taxi drivers’ operation and behavior pattern identification, as well as the contribution to the geographical activity space analysis.

Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes).

Science.gov (United States)

Ksepka, Daniel T; Clarke, Julia A; Nesbitt, Sterling J; Kulp, Felicia B; Grande, Lance

2013-06-22

A feathered specimen of a new species of Eocypselus from the Early Eocene Green River Formation of Wyoming provides insight into the wing morphology and ecology in an early part of the lineage leading to extant swifts and hummingbirds. Combined phylogenetic analysis of morphological and molecular data supports placement of Eocypselus outside the crown radiation of Apodiformes. The new specimen is the first described fossil of Pan-Apodiformes from the pre-Pleistocene of North America and the only reported stem taxon with informative feather preservation. Wing morphology of Eocypselus rowei sp. nov. is intermediate between the short wings of hummingbirds and the hyper-elongated wings of extant swifts, and shows neither modifications for the continuous gliding used by swifts nor modifications for the hovering flight style used by hummingbirds. Elongate hindlimb elements, particularly the pedal phalanges, also support stronger perching capabilities than are present in Apodiformes. The new species is the smallest bird yet described from the Green River Formation, and supports the hypothesis that a decrease in body size preceded flight specializations in Pan-Apodiformes. The specimen also provides the first instance of melanosome morphology preserved in association with skeletal remains from the Green River Formation.

Agent-Based Modeling of Taxi Behavior Simulation with Probe Vehicle Data

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Saurav Ranjit

2018-05-01

Full Text Available Taxi behavior is a spatial–temporal dynamic process involving discrete time dependent events, such as customer pick-up, customer drop-off, cruising, and parking. Simulation models, which are a simplification of a real-world system, can help understand the effects of change of such dynamic behavior. In this paper, agent-based modeling and simulation is proposed, that describes the dynamic action of an agent, i.e., taxi, governed by behavior rules and properties, which emulate the taxi behavior. Taxi behavior simulations are fundamentally done for optimizing the service level for both taxi drivers as well as passengers. Moreover, simulation techniques, as such, could be applied to another field of application as well, where obtaining real raw data are somewhat difficult due to privacy issues, such as human mobility data or call detail record data. This paper describes the development of an agent-based simulation model which is based on multiple input parameters (taxi stay point cluster; trip information (origin and destination; taxi demand information; free taxi movement; and network travel time that were derived from taxi probe GPS data. As such, agent’s parameters were mapped into grid network, and the road network, for which the grid network was used as a base for query/search/retrieval of taxi agent’s parameters, while the actual movement of taxi agents was on the road network with routing and interpolation. The results obtained from the simulated taxi agent data and real taxi data showed a significant level of similarity of different taxi behavior, such as trip generation; trip time; trip distance as well as trip occupancy, based on its distribution. As for efficient data handling, a distributed computing platform for large-scale data was used for extracting taxi agent parameter from the probe data by utilizing both spatial and non-spatial indexing technique.

Applying chemical stimuli on feathers to reduce feather pecking in laying hens

NARCIS (Netherlands)

Harlander Matauschek, A.; Rodenburg, T.B.

2011-01-01

Recent studies have shown that spraying a distasteful substance (quinine) on a bird's feather cover reduced short-term feather pecking. The present experiment evaluated if other substances offer similar or better protection against feather pecking. One hundred and twenty birds were divided into 12

A COMMUNITY STUDY OF TAXI VIOLENCE AND DISTRESS ...

African Journals Online (AJOL)

Setting & Subjects: Five hundred and four Xhosa speaking youth aged 9-20 years, from 5 primary schools in Khayelitsha; 396 attending 4 schools in close proximity to ... Those who had been in a taxi that was shot at, those who had been at a taxi rank when people were shot, and those who had seen taxi men shooting, had ...

Comparison of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers in bald eagle (Haliaeetus leucocephalus), and comparison with common eider (Somateria mollissima), glaucous-winged gull (Larus glaucescens), pigeon guillemot (Cepphus columba), and tufted puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska

Science.gov (United States)

Burger, Joanna; Gochfeld, Michael

2014-01-01

There is an abundance of field data for levels of metals from a range of places, but relatively few from the North Pacific Ocean and Bering Sea. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens), pigeon guillemots (Cepphus columba), tufted puffins (Fratercula cirrhata) and bald eagles (Haliaeetus leucocephalus) from the Aleutian Chain of Alaska. Our primary objective was to test the hypothesis that there are no trophic levels relationships for arsenic, cadmium, chromium, lead, manganese, mercury and selenium among these five species of birds breeding in the marine environment of the Aleutians. There were significant interspecific differences in all metal levels. As predicted bald eagles had the highest levels of arsenic, chromium, lead, and manganese, but puffins had the highest levels of selenium, and pigeon guillemot had higher levels of mercury than eagles (although the differences were not significant). Common eiders, at the lowest trophic level had the lowest levels of some metals (chromium, mercury and selenium). However, eiders had higher levels than all other species (except eagles) for arsenic, cadmium, lead, and manganese. Levels of lead were higher in breast than in wing feathers of bald eagles. Except for lead, there were no significant differences in metal levels in feathers of bald eagles nesting on Adak and Amchitka Island; lead was higher on Adak than Amchitka. Eagle chicks tended to have lower levels of manganese than older eagles. PMID:18521716

Taxi and limousine industry in Canada

International Nuclear Information System (INIS)

Monteiro, J.; Civettini, S.

2007-01-01

Taxi and limousine service plays an important role in the movement of people within a city. In 2004, the total revenue in this industry in Canada was $1.305 billion, and an estimated 35,339 carriers served the industry. In Canada, economic and safety regulations of taxi supply were imposed in most cities during the 1930s and 1940s and continue to this date. Although the industry is regulated, the competition law also applies. The appropriateness of these regulations continues to be challenged and regulatory reforms in the major cities in Canada have concentrated their efforts on increasing the rate of services, improving the quality of vehicles and enhancing the training of taxi drivers. Indicators for the 1999-2004 period reveal that the taxi and limousine industry in Canada did not perform very well. Revenue increased by only 1.7 per cent per year and margins deteriorated by -1.78 per cent together with the operating ratio. The purpose of this paper was to examine the taxi and limousine industry in Canada. First, the structure of the industry in Canada was examined followed by a review of the economic regulation of the industry. Recent regulatory developments in Canada and in other countries were then reviewed with arguments for or against deregulation. 28 refs., 2 tabs

Gliding swifts attain laminar flow over rough wings.

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David Lentink

Full Text Available Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1-2% of chord length on the upper surface--10,000 times rougher than sailplane wings. Sailplanes depend on extreme wing smoothness to increase the area of laminar flow on the wing surface and minimize drag for extended glides. To understand why the swift does not rely on smooth wings, we used a stethoscope to map laminar flow over preserved wings in a low-turbulence wind tunnel. By combining laminar area, lift, and drag measurements, we show that average area of laminar flow on swift wings is 69% (n = 3; std 13% of their total area during glides that maximize flight distance and duration--similar to high-performance sailplanes. Our aerodynamic analysis indicates that swifts attain laminar flow over their rough wings because their wing size is comparable to the distance the air travels (after a roughness-induced perturbation before it transitions from laminar to turbulent. To interpret the function of swift wing roughness, we simulated its effect on smooth model wings using physical models. This manipulation shows that laminar flow is reduced and drag increased at high speeds. At the speeds at which swifts cruise, however, swift-like roughness prolongs laminar flow and reduces drag. This feature gives small birds with rudimentary wings an edge during the evolution of glide performance.

among Taxi Drivers in Addis Ababa, Ethiopia

African Journals Online (AJOL)

user

Long years of driving [AOR =4.6 (95%CI, 1.6-12.9)], involvement in a similar activity prior to becoming taxi driver .... full time taxi driver; produce a valid driving license; .... Self-employee .... professional car drivers in Dhaka city, Bangladesh.

On the Morphogenesis of Feathers

Science.gov (United States)

Yu, Mingke; Wu, Ping; Widelitz, Randall B.; Chuong, Cheng-Ming

2015-01-01

The most unique character of the feather is its highly ordered hierarchical branched structure1, 2. This evolutionary novelty confers flight function to birds3–5. Recent discoveries of fossils in China have prompted keen interest in the origin and evolution of feathers6–14. However, controversy arises whether the irregularly branched integumentary fibers on dinosaurs such as Sinornithosaurus are truly feathers6, 11, and whether an integumentary appendage with a major central shaft and notched edges is a non-avian feather or a proto-feather8–10. Here we take a developmental approach to analyze molecular mechanisms in feather branching morphogenesis. We have used the replication competent avian sarcoma (RCAS) retrovirus15 to efficiently deliver exogenous genes to regenerating chicken flight feather follicles. We show that the antagonistic balance between noggin and bone morphogenetic protein 4 (BMP4) plays a critical role in feather branching, with BMP4 promoting rachis formation and barb fusion, and noggin enhancing rachis and barb branching. Furthermore we show that sonic hedgehog (SHH) is essential for apoptosis of the marginal plate epithelia to become spaces between barbs. Our analyses show the molecular pathways underlying the topological transformation of feathers from cylindrical epithelia to the hierarchical branched structures, and provide first clues on the possible developmental mechanisms in the evolution of feather forms. PMID:12442169

Research on taxi software policy based on big data

Directory of Open Access Journals (Sweden)

Feng Daoming

2017-01-01

Full Text Available Through big data analysis, statistical analysis of a large number of factors affect the establishment of the rally car index set, By establishing a mathematical model to analyze the different space-time taxi resource “to match supply and demand” degree, combined with intelligent deployment to solve the “taxi difficult” this hot social issues. This article takes Shanghai as an example, the central park, Lu Xun park, century park three areas as the object of study. From the “sky drops fast travel intelligence platform” big data, Extracted passenger demand and the number of taxi Kongshi data. Then demand and supply of taxis to establish indicators matrix, get the degree of matching supply needs of the region. Then through the big data relevant policies of each taxi company. Using the method of cluster analysis, to find the decisive role of the three aspects of the factors, using principal component analysis, compare the advantages and disadvantages of the existing company’s programs. Finally, according to the above research to develop a reasonable taxi software related policies.

Morphological properties of the last primaries, the tail feathers, and the alulae of Accipiter nisus, Columba livia, Falco peregrinus, and Falco tinnunculus.

Science.gov (United States)

Schmitz, Anke; Ponitz, Benjamin; Brücker, Christoph; Schmitz, Helmut; Herweg, Jan; Bleckmann, Horst

2015-01-01

We investigated the mechanical properties (Young's modulus, bending stiffness, barb separation forces) of the tenth primary of the wings, of the alulae and of the middle tail feathers of Falco peregrinus. For comparison, we also investigated the corresponding feathers in pigeons (Columba livia), kestrels (Falco tinnunculus), and sparrowhawks (Accipiter nisus). In all four species, the Young's moduli of the feathers ranged from 5.9 to 8.4 GPa. The feather shafts of F. peregrinus had the largest cross-sections and the highest specific bending stiffness. When normalized with respect to body mass, the specific bending stiffness of primary number 10 was highest in F. tinnunculus, while that of the alula was highest in A. nisus. In comparison, the specific bending stiffness, measured at the base of the tail feathers and in dorso-ventral bending direction, was much higher in F. peregrinus than in the other three species. This seems to correlate with the flight styles of the birds: F. tinnunculus hovers and its primaries might therefore withstand large mechanical forces. A. nisus has often to change its flight directions during hunting and perhaps needs its alulae for this maneuvers, and in F. peregrinus, the base of the tail feathers might need a high stiffness during breaking after diving. © 2014 Wiley Periodicals, Inc.

Fuel cell hybrid taxi life cycle analysis

Energy Technology Data Exchange (ETDEWEB)

Baptista, Patricia, E-mail: patricia.baptista@ist.utl.pt [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ribau, Joao; Bravo, Joao; Silva, Carla [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Adcock, Paul; Kells, Ashley [Intelligent Energy, Charnwood Building, HolywellPark, Ashby Road, Loughborough, LE11 3GR (United Kingdom)

2011-09-15

A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO{sub 2} emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO{sub 2} emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: > A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. > The hydrogen powered vehicles have the lowest energy consumption and CO{sub 2} emissions results. > A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

Fuel cell hybrid taxi life cycle analysis

International Nuclear Information System (INIS)

Baptista, Patricia; Ribau, Joao; Bravo, Joao; Silva, Carla; Adcock, Paul; Kells, Ashley

2011-01-01

A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO 2 emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO 2 emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: → A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. → The hydrogen powered vehicles have the lowest energy consumption and CO 2 emissions results. → A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

Bioinspired morphing wings for extended flight envelope and roll control of small drones.

Science.gov (United States)

Di Luca, M; Mintchev, S; Heitz, G; Noca, F; Floreano, D

2017-02-06

Small-winged drones can face highly varied aerodynamic requirements, such as high manoeuvrability for flight among obstacles and high wind resistance for constant ground speed against strong headwinds that cannot all be optimally addressed by a single aerodynamic profile. Several bird species solve this problem by changing the shape of their wings to adapt to the different aerodynamic requirements. Here, we describe a novel morphing wing design composed of artificial feathers that can rapidly modify its geometry to fulfil different aerodynamic requirements. We show that a fully deployed configuration enhances manoeuvrability while a folded configuration offers low drag at high speeds and is beneficial in strong headwinds. We also show that asymmetric folding of the wings can be used for roll control of the drone. The aerodynamic performance of the morphing wing is characterized in simulations, in wind tunnel measurements and validated in outdoor flights with a small drone.

Effectiveness of clean taxi priority incentive at Amsterdam Central Station

NARCIS (Netherlands)

van der Flier, A.S.; Dam, J.; van den Hoed, R.

2017-01-01

The municipality of Amsterdam wants to have an emission free taxi sector by 2025. In order to reach that goal, the city has taken a number of measures which favour clean taxis above conventional taxis. One of these measures is an innovative priority privilege scheme at the Amsterdam Central Station

Applicative Research on Psychological Demand of Audience and the TAXI for People

Directory of Open Access Journals (Sweden)

Zhang Caixia

2015-01-01

Full Text Available Whether TAXI for People from Beijing traffic channel, the only special program customized for taxi driver in Beijing, knows about the psychological feature of the certain taxi group is an important factor that affects the development of program. Based on demand theory of psychology, this article uses the questionnaire method to find out the psychological feature and lifestyle of audience, and discusses the degree to the TAXI for People which meets the psychological demand of taxi driver audience by analysis on the program content. It is said from the research that the TAXI for People basically meets the psychological demand from taxi drivers. However, this program shall focus more on their basic needs and provide the opportunity for the audience to participate in the program and activity.

A WEB-BASED PLATFORM FOR VISUALIZING SPATIOTEMPORAL DYNAMICS OF BIG TAXI DATA

Directory of Open Access Journals (Sweden)

H. Xiong

2017-09-01

Full Text Available With more and more vehicles equipped with Global Positioning System (GPS, access to large-scale taxi trajectory data has become increasingly easy. Taxis are valuable sensors and information associated with taxi trajectory can provide unprecedented insight into many aspects of city life. But analysing these data presents many challenges. Visualization of taxi data is an efficient way to represent its distributions and structures and reveal hidden patterns in the data. However, Most of the existing visualization systems have some shortcomings. On the one hand, the passenger loading status and speed information cannot be expressed. On the other hand, mono-visualization form limits the information presentation. In view of these problems, this paper designs and implements a visualization system in which we use colour and shape to indicate passenger loading status and speed information and integrate various forms of taxi visualization. The main work as follows: 1. Pre-processing and storing the taxi data into MongoDB database. 2. Visualization of hotspots for taxi pickup points. Through DBSCAN clustering algorithm, we cluster the extracted taxi passenger’s pickup locations to produce passenger hotspots. 3. Visualizing the dynamic of taxi moving trajectory using interactive animation. We use a thinning algorithm to reduce the amount of data and design a preloading strategyto load the data smoothly. Colour and shape are used to visualize the taxi trajectory data.

a Web-Based Platform for Visualizing Spatiotemporal Dynamics of Big Taxi Data

Science.gov (United States)

Xiong, H.; Chen, L.; Gui, Z.

2017-09-01

With more and more vehicles equipped with Global Positioning System (GPS), access to large-scale taxi trajectory data has become increasingly easy. Taxis are valuable sensors and information associated with taxi trajectory can provide unprecedented insight into many aspects of city life. But analysing these data presents many challenges. Visualization of taxi data is an efficient way to represent its distributions and structures and reveal hidden patterns in the data. However, Most of the existing visualization systems have some shortcomings. On the one hand, the passenger loading status and speed information cannot be expressed. On the other hand, mono-visualization form limits the information presentation. In view of these problems, this paper designs and implements a visualization system in which we use colour and shape to indicate passenger loading status and speed information and integrate various forms of taxi visualization. The main work as follows: 1. Pre-processing and storing the taxi data into MongoDB database. 2. Visualization of hotspots for taxi pickup points. Through DBSCAN clustering algorithm, we cluster the extracted taxi passenger's pickup locations to produce passenger hotspots. 3. Visualizing the dynamic of taxi moving trajectory using interactive animation. We use a thinning algorithm to reduce the amount of data and design a preloading strategyto load the data smoothly. Colour and shape are used to visualize the taxi trajectory data.

Aerostructural Level Set Topology Optimization for a Common Research Model Wing

Science.gov (United States)

Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia

2014-01-01

The purpose of this work is to use level set topology optimization to improve the design of a representative wing box structure for the NASA common research model. The objective is to minimize the total compliance of the structure under aerodynamic and body force loading, where the aerodynamic loading is coupled to the structural deformation. A taxi bump case was also considered, where only body force loads were applied. The trim condition that aerodynamic lift must balance the total weight of the aircraft is enforced by allowing the root angle of attack to change. The level set optimization method is implemented on an unstructured three-dimensional grid, so that the method can optimize a wing box with arbitrary geometry. Fast matching and upwind schemes are developed for an unstructured grid, which make the level set method robust and efficient. The adjoint method is used to obtain the coupled shape sensitivities required to perform aerostructural optimization of the wing box structure.

System dynamics model of taxi management in metropolises: Economic and environmental implications for Beijing.

Science.gov (United States)

Wang, Hao; Zhang, Kai; Chen, Junhua; Wang, Zhifeng; Li, Guijun; Yang, Yuqi

2018-05-01

Taxis are an important component of urban passenger transport. Research on the daily dispatching of taxis and the utility of governmental management is important for the improvement of passenger travel, taxi driver income and environmental impacts. However, urban taxi management is a complex and dynamic system that is affected by many factors, and positive/negative feedback relationships and nonlinear interactions exist between each subsystem and variable. Therefore, conventional research methods can hardly depict its characteristics comprehensively. To bridge this gap, this paper develops a system dynamics model of urban taxi management, in which the empty-loaded rate and total demand are selected as key factors affecting taxi dispatching, and the impacts of taxi fares on driver income and travel demand are taken into account. After the validation of the model, taxi operations data derived from a prior analysis of origin-destination data of Beijing taxis are used as input for the model to simulate the taxi market in Beijing. Finally, economic and environmental implications are provided for the government to optimise policies on taxi management. Copyright © 2018 Elsevier Ltd. All rights reserved.

Premature feather loss among common tern chicks in Ontario: the return of an enigmatic developmental anomaly

Directory of Open Access Journals (Sweden)

Jennifer M. Arnold

2016-05-01

Full Text Available In July 2014, we observed premature feather loss (PFL among non-sibling, common tern Sterna hirundo chicks between two and four weeks of age at Gull Island in northern Lake Ontario, Canada. Rarely observed in wild birds, to our knowledge PFL has not been recorded in terns since 1974, despite the subsequent banding of hundreds of thousands of tern chicks across North America alone. The prevalence, 5% of chicks (9/167, and extent of feather loss we report is more extreme than in previous reports for common terns but was not accompanied by other aberrant developmental or physical deformities. Complete feather loss from all body areas (wing, tail, head and body occurred over a period of a few days but all affected chicks appeared vigorous and quickly began to grow replacement feathers. All but one chick (recovered dead and submitted for post-mortem most likely fledged 10–20 days after normal fledging age. We found no evidence of feather dystrophy or concurrent developmental abnormalities unusual among affected chicks. Thus, the PFL we observed among common terns in 2014 was largely of unknown origin. There was striking temporal association between the onset of PFL and persistent strong southwesterly winds that caused extensive mixing of near-shore surface water with cool, deep lake waters. One hypothesis is that PFL may have been caused by unidentified pathogens or toxins welling up from these deep waters along the shoreline but current data are insufficient to test this. PFL was not observed among common terns at Gull Island in 2015, although we did observe similar feather loss in a herring gull Larus argentatus chick in that year. Comparison with sporadic records of PFL in other seabirds suggests that PFL may be a rare, but non-specific, response to a range of potential stressors. PFL is now known for gulls, penguins and terns.

Optimizing Cruising Routes for Taxi Drivers Using a Spatio-Temporal Trajectory Model

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Liang Wu

2017-11-01

Full Text Available Much of the taxi route-planning literature has focused on driver strategies for finding passengers and determining the hot spot pick-up locations using historical global positioning system (GPS trajectories of taxis based on driver experience, distance from the passenger drop-off location to the next passenger pick-up location and the waiting times at recommended locations for the next passenger. The present work, however, considers the average taxi travel speed mined from historical taxi GPS trajectory data and the allocation of cruising routes to more than one taxi driver in a small-scale region to neighboring pick-up locations. A spatio-temporal trajectory model with load balancing allocations is presented to not only explore pick-up/drop-off information but also provide taxi drivers with cruising routes to the recommended pick-up locations. In simulation experiments, our study shows that taxi drivers using cruising routes recommended by our spatio-temporal trajectory model can significantly reduce the average waiting time and travel less distance to quickly find their next passengers, and the load balancing strategy significantly alleviates road loads. These objective measures can help us better understand spatio-temporal traffic patterns and guide taxi navigation.

Identification of a feather β-keratin gene exclusively expressed in pennaceous barbule cells of contour feathers in chicken.

Science.gov (United States)

Kowata, Kinue; Nakaoka, Minori; Nishio, Kaori; Fukao, Ayaka; Satoh, Akira; Ogoshi, Maho; Takahashi, Sumio; Tsudzuki, Masaoki; Takeuchi, Sakae

2014-05-25

Feathers are elaborate skin appendages shared by birds and theropod dinosaurs that have hierarchical branching of the rachis, barbs, and barbules. Feather filaments consist of β-keratins encoded by multiple genes, most of which are located in tandem arrays on chromosomes 2, 25, and 27 in chicken. The expansion of the genes is thought to have contributed to feather evolution; however, it is unclear how the individual genes are involved in feather formation. The aim of the present study was to identify feather keratin genes involved in the formation of barbules. Using a combination of microarray analysis, reverse-transcription polymerase chain reaction, and in situ hybridization, we found an uncharacterized keratin gene on chromosome 7 that was expressed specifically in barbule cells in regenerating chicken feathers. We have named the gene barbule specific keratin 1 (BlSK1). The BlSK1 gene structure was similar to the gene structure of previously characterized feather keratin genes, and consisted of a non-coding leader exon, an intron, and an exon with an open reading frame (ORF). The ORF was predicted to encode a 98 aa long protein, which shared 59% identity with feather keratin B. Orthologs of BlSK1 were found in the genomes of other avian species, including turkey, duck, zebra finch, and flycatcher, in regions that shared synteny with chromosome 7 of chicken. Interestingly, BlSK1 was expressed in feather follicles that generated pennaceous barbules but not in follicles that generated plumulaceous barbules. These results suggested that the composition of feather keratins probably varies depending on the structure of the feather filaments and, that individual feather keratin genes may be involved in building different portions and/or types of feathers in chicken. Copyright © 2014 Elsevier B.V. All rights reserved.

Feather eating and its associations with plumage damage and feathers on the floor in commercial farms of laying hens

DEFF Research Database (Denmark)

Riber, Anja Brinch; Hinrichsen, Lena Karina

2016-01-01

Feather eating has been associated with feather pecking, which continues to pose economic and welfare problems in egg production. Knowledge on feather eating is limited and studies of feather eating in commercial flocks of laying hens have not been performed previously. Therefore, the main...... objective was to investigate feather eating and its association with plumage damage and floor feather characteristics in commercial flocks of layers in barn and organic production systems. The study was performed in 13 flocks of barn layers and 17 flocks of organic layers. Each flock was visited at around.......3% in organic; P=0.99). Our hypothesis about a positive correlation between feather eating and plumage damage was not supported as no correlation was found between the prevalence of poor plumage condition and the prevalence of droppings with feather content. However, the prevalence of pecking damaged floor...

Exploring Spatiotemporal Patterns of Long-Distance Taxi Rides in Shanghai

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Hangbin Wu

2017-11-01

Full Text Available Floating Car Data (FCD has been analyzed for various purposes in past years. However, limited research about the behaviors of taking long-distance taxi rides has been made available. In this paper, we used data from over 12,000 taxis during a six-month period in Shanghai to analyze the spatiotemporal patterns of long-distance taxi trips. We investigated these spatiotemporal patterns by comparing them with metro usage in Shanghai, in order to determine the extent and how the suburban trains divert the passenger flow from taxis. The results identified 12 pick-up and six drop-off hotspots in Shanghai. Overall, the pick-up locations were relatively more concentrated than the drop-off locations. Temporal patterns were also revealed. Passengers on long-distance taxi rides were observed to avoid the rush hours on the street as their first priority and tried to avoid the inconvenience of interchanges on the metro lines as their second priority.

What makes a feather shine? A nanostructural basis for glossy black colours in feathers.

Science.gov (United States)

Maia, Rafael; D'Alba, Liliana; Shawkey, Matthew D

2011-07-07

Colours in feathers are produced by pigments or by nanostructurally organized tissues that interact with light. One of the simplest nanostructures is a single layer of keratin overlying a linearly organized layer of melanosomes that create iridescent colours of feather barbules through thin-film interference. Recently, it has been hypothesized that glossy (i.e. high specular reflectance) black feathers may be evolutionarily intermediate between matte black and iridescent feathers, and thus have a smooth keratin layer that produces gloss, but not the layered organization of melanosomes needed for iridescence. However, the morphological bases of glossiness remain unknown. Here, we use a theoretical approach to generate predictions about morphological differences between matte and glossy feathers that we then empirically test. Thin-film models predicted that glossy spectra would result from a keratin layer 110-180 nm thick and a melanin layer greater than 115 nm thick. Transmission electron microscopy data show that nanostructure of glossy barbules falls well within that range, but that of matte barbules does not. Further, glossy barbules had a thinner and more regular keratin cortex, as well as a more continuous underlying melanin layer, than matte barbules. Thus, their quasi-ordered nanostructures are morphologically intermediate between matte black and iridescent feathers, and perceived gloss may be a form of weakly chromatic iridescence.

Feather eating and its associations with plumage damage and feathers on the floor in commercial farms of laying hens

DEFF Research Database (Denmark)

Riber, Anja Brinch; Hinrichsen, Lena Karina

2016-01-01

Feather eating has been associated with feather pecking, which continues to pose economic and welfare problems in egg production. Knowledge on feather eating is limited and studies of feather eating in commercial flocks of laying hens have not been performed previously. Therefore, the main object...

Transcendence, Taxis, Trust: Richard Kearney and Jacques Derrida

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Ulrich Schmiedel

2017-03-01

Full Text Available Whatever else it takes to drive a taxi, it takes trust. Day after day, the driver has to decide whether the other is or is not trustworthy. I take the taxi as a test case to analyze and assess Richard Kearney’s diacritical hermeneutics of the other. I argue that Kearney functionalizes the concept of transcendence in order to connect the transcendence of the finite other to the transcendence of the infinite other. However, in his central critique of the deconstructionists following Jacques Derrida, Kearney counters his connection. While Kearney’s critique of Derrida’s account of absolute alterity is correct and compelling, I argue that Derrida’s critique of a distinction between the trustworthy other and the non-trustworthy other might be more crucial than Kearney contends. Insisting on openness to the other’s otherness, Derrida provokes any hermeneutic of the other to trust in transcendence. The taxi is taken as a test to illustrate the implications which diacritical and deconstructive drivers might have for evaluating the entanglement of ethics and eschatology—inside and outside the taxi.

Social optimal shifts and fares of taxi services

Energy Technology Data Exchange (ETDEWEB)

Salanova Grau, J.M.; Estrada Romeu, M.

2016-07-01

This paper presents a mathematical model for supporting the decision and policy making related to the optimal determination of shifts and fares of taxi services in a major city. The model is based on the system’s generalized cost function and uses continuous approximations and geometric probabilities for estimating the key performance indicators of the taxi market, which are waiting and access time for the customers (in-vehicle travel time does not depend on the offer side) and benefits for the drivers. The model is based on an econometric model with the inclusion of an elastic demand, which allows the estimation of the optimal values for the two decision variables of the problem: fare structure and the taxi fleet size. The model also accounts for a full-day time period instead of the one-hour time frame models used in most of the taxi models, which allows for providing insights on the daily duration and distribution of the shifts that should be defined by the policy makers. (Author)

Feather corticosterone reveals developmental stress in seabirds.

Science.gov (United States)

Will, Alexis P; Suzuki, Yuya; Elliott, Kyle H; Hatch, Scott A; Watanuki, Yutaka; Kitaysky, Alexander S

2014-07-01

In nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (CORT). Recent studies indicate that CORT is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. The current hypothesis predicts that, assuming a constant rate of feather growth, elevated CORT circulating in the blood corresponds to higher levels of CORT in feather tissue, but experimental evidence for nutritionally stressed chicks is lacking. Here, we examined how food limitation affects feather CORT content in the rhinoceros auklet (Cerorhinca moncerata). We (i) used captive chicks reared on control versus restricted diets, and (ii) applied this technique to free-living chicks with unknown nutritional histories that fledged at three separate colonies. We found that (i) feather growth was not affected by experimentally induced nutritional stress; (ii) captive chicks raised on a restricted diet had higher levels of CORT in their primary feathers; (iii) feather CORT deposition is a sensitive method of detecting nutritional stress; and (iv) free-living fledglings from the colony with poor reproductive performance had higher CORT in their primary feathers. We conclude that feather CORT is a sensitive integrated measure revealing the temporal dynamics of food limitations experienced by rhinoceros auklet nestlings. The use of feather CORT may be a powerful endocrine tool in ecological and evolutionary studies of bird species with similar preferential allocation of limited resources to feather development. © 2014. Published by The Company of Biologists Ltd.

The wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents

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T. Alexander Dececchi

2016-07-01

Full Text Available Background: Powered flight is implicated as a major driver for the success of birds. Here we examine the effectiveness of three hypothesized pathways for the evolution of the flight stroke, the forelimb motion that powers aerial locomotion, in a terrestrial setting across a range of stem and basal avians: flap running, Wing Assisted Incline Running (WAIR, and wing-assisted leaping. Methods: Using biomechanical mathematical models based on known aerodynamic principals and in vivo experiments and ground truthed using extant avians we seek to test if an incipient flight stroke may have contributed sufficient force to permit flap running, WAIR, or leaping takeoff along the phylogenetic lineage from Coelurosauria to birds. Results: None of these behaviours were found to meet the biomechanical threshold requirements before Paraves. Neither was there a continuous trend of refinement for any of these biomechanical performances across phylogeny nor a signal of universal applicability near the origin of birds. None of these flap-based locomotory models appear to have been a major influence on pre-flight character acquisition such as pennaceous feathers, suggesting non-locomotory behaviours, and less stringent locomotory behaviours such as balancing and braking, played a role in the evolution of the maniraptoran wing and nascent flight stroke. We find no support for widespread prevalence of WAIR in non-avian theropods, but can’t reject its presence in large winged, small-bodied taxa like Microraptor and Archaeopteryx. Discussion: Using our first principles approach we find that “near flight” locomotor behaviors are most sensitive to wing area, and that non-locomotory related selection regimes likely expanded wing area well before WAIR and other such behaviors were possible in derived avians. These results suggest that investigations of the drivers for wing expansion and feather elongation in theropods need not be intrinsically linked to locomotory

Fuel cell drive for a taxi; Brennstoffzellen-Antrieb fuer ein Elektro-Taxi

Energy Technology Data Exchange (ETDEWEB)

Barker, Phil; Rosario, Leon; Sharp, Jon; Pouzet, Axel [Lotus Engineering, Norfolk (United Kingdom)

2011-11-15

Together with some partners Lotus Engineering has developed a fuel cell drive for a taxi. The prototype uses a Lithium Polymer battery pack as the peak power source and is analysed as an alternative for diesel drives in urban areas with stringent emission regulations. (orig.)

Uncovering urban human mobility from large scale taxi GPS data

Science.gov (United States)

Tang, Jinjun; Liu, Fang; Wang, Yinhai; Wang, Hua

2015-11-01

Taxi GPS trajectories data contain massive spatial and temporal information of urban human activity and mobility. Taking taxi as mobile sensors, the information derived from taxi trips benefits the city and transportation planning. The original data used in study are collected from more than 1100 taxi drivers in Harbin city. We firstly divide the city area into 400 different transportation districts and analyze the origin and destination distribution in urban area on weekday and weekend. The Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm is used to cluster pick-up and drop-off locations. Furthermore, four spatial interaction models are calibrated and compared based on trajectories in shopping center of Harbin city to study the pick-up location searching behavior. By extracting taxi trips from GPS data, travel distance, time and average speed in occupied and non-occupied status are then used to investigate human mobility. Finally, we use observed OD matrix of center area in Harbin city to model the traffic distribution patterns based on entropy-maximizing method, and the estimation performance verify its effectiveness in case study.

Evaluating the accuracy of GPS-based taxi trajectory records

NARCIS (Netherlands)

Zheng, Zhong; Rasouli, Soora; Timmermans, Harry

2014-01-01

Taxi data are an underused source of travel information. A handful of research has been concerned with the processing of raw taxi GPS data to minimize random error. The study of methods that systematically detect erroneous data has, however, received less attention. Generally, an origin and a

Butterfly wing coloration studied with a novel imaging scatterometer

Science.gov (United States)

Stavenga, Doekele

2010-03-01

Animal coloration functions for display or camouflage. Notably insects provide numerous examples of a rich variety of the applied optical mechanisms. For instance, many butterflies feature a distinct dichromatism, that is, the wing coloration of the male and the female differ substantially. The male Brimstone, Gonepteryx rhamni, has yellow wings that are strongly UV iridescent, but the female has white wings with low reflectance in the UV and a high reflectance in the visible wavelength range. In the Small White cabbage butterfly, Pieris rapae crucivora, the wing reflectance of the male is low in the UV and high at visible wavelengths, whereas the wing reflectance of the female is higher in the UV and lower in the visible. Pierid butterflies apply nanosized, strongly scattering beads to achieve their bright coloration. The male Pipevine Swallowtail butterfly, Battus philenor, has dorsal wings with scales functioning as thin film gratings that exhibit polarized iridescence; the dorsal wings of the female are matte black. The polarized iridescence probably functions in intraspecific, sexual signaling, as has been demonstrated in Heliconius butterflies. An example of camouflage is the Green Hairstreak butterfly, Callophrys rubi, where photonic crystal domains exist in the ventral wing scales, resulting in a matte green color that well matches the color of plant leaves. The spectral reflection and polarization characteristics of biological tissues can be rapidly and with unprecedented detail assessed with a novel imaging scatterometer-spectrophotometer, built around an elliptical mirror [1]. Examples of butterfly and damselfly wings, bird feathers, and beetle cuticle will be presented. [4pt] [1] D.G. Stavenga, H.L. Leertouwer, P. Pirih, M.F. Wehling, Optics Express 17, 193-202 (2009)

REQUIREMENTS FOR DESIGN, EQUIPMENT AND OPERATION MODE OF TAXI VEHICLES

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Norayr Oganesovich Bludyan

2015-09-01

Full Text Available The analysis of international experience in application of requirements for the taxi vehicles design and equipment. The approaches to improvement of cabbing have been defined by determination of requirements for taxi vehicles.

Primary feather molt of adult mourning doves in North and South Carolina

Science.gov (United States)

Haas, G.H.; Amend, S.R.

1979-01-01

Examination of 8,141 adult mourning doves (Zenaida macroura) in North and South Carolina revealed that substantial numbers complete primary feather molt in September. Adult mourning doves shed primaries at the rate of 1 per 14 days. No difference was found in this rate between sexes or among years, 1969-74. The initiation of molt differed from year to year, and female molt always preceded male molt. Available data show that southern doves complete primary molt a month earlier than northern doves. Therefore, age based on primary molt can be biased upward if all molt-complete wings from southern hunting samples are considered immature.

Alternative fish feed production from waste chicken feathers

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Sri Jumini

2017-08-01

Full Text Available In this This devotion has been done to provide education and training of the utilization of waste chicken manure, making flour chicken feathers as a fish feed alternative, that can overcome some of the problems that waste chicken feathers from the center cutting broiler chickens in the village Krasak enough, it causes pollution, and not used optimally; Low public awareness of awareness of environmental pollution; the lack of public knowledge about the utilization of waste chicken feathers, and processing technology, as well as to address the needs of fish feed more expensive, need alternative feed ingredients. This service program has provided insight to the public about waste chicken feathers so that it can be used as a new entrepreneurial startups. To achieve these objectives have been done of activity as follows: 1 Provide counseling and understanding of the community will be a negative impact on the environment of waste chicken feathers. 2 Provide counseling utilization of waste chicken feathers for people in nearby farms. 3 Make a chicken feather meal of chicken feather waste as an alternative fish feed to improve digestibility of chicken feathers. 3 The formation of the group for increasing the economic income of the family. This service activities program runs quite well with demonstrated some activity, namely: 1 Change Behavior Society (knowledge transfer; 2 Chicken Feather Extension Waste Utilization; 3 Making Unit Waste Chicken Feathers; 4 Establishment of New Business of Diversified Waste Chicken Feathers.

Structural coloration in a fossil feather.

Science.gov (United States)

Vinther, Jakob; Briggs, Derek E G; Clarke, Julia; Mayr, Gerald; Prum, Richard O

2010-02-23

Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs.

Fossilized skin reveals coevolution with feathers and metabolism in feathered dinosaurs and early birds.

Science.gov (United States)

McNamara, Maria E; Zhang, Fucheng; Kearns, Stuart L; Orr, Patrick J; Toulouse, André; Foley, Tara; Hone, David W E; Rogers, Chris S; Benton, Michael J; Johnson, Diane; Xu, Xing; Zhou, Zhonghe

2018-05-25

Feathers are remarkable evolutionary innovations that are associated with complex adaptations of the skin in modern birds. Fossilised feathers in non-avian dinosaurs and basal birds provide insights into feather evolution, but how associated integumentary adaptations evolved is unclear. Here we report the discovery of fossil skin, preserved with remarkable nanoscale fidelity, in three non-avian maniraptoran dinosaurs and a basal bird from the Cretaceous Jehol biota (China). The skin comprises patches of desquamating epidermal corneocytes that preserve a cytoskeletal array of helically coiled α-keratin tonofibrils. This structure confirms that basal birds and non-avian dinosaurs shed small epidermal flakes as in modern mammals and birds, but structural differences imply that these Cretaceous taxa had lower body heat production than modern birds. Feathered epidermis acquired many, but not all, anatomically modern attributes close to the base of the Maniraptora by the Middle Jurassic.

Optimization of the revenue of the New York city taxi service using Markov Decision Processes

NARCIS (Netherlands)

Li, P.; Bhulai, Sandjai; van Essen, J.T.; Bhulai, Sandjai; Kardaras, Dimitris

2017-01-01

Taxis are an essential component of the transportation system in most urban centers. The ability to optimize the efficiency of routing represents an opportunity to increase revenues for taxi drivers. The vacant taxis cruising on the roads are not only wasting fuel consumption, the time of a taxi

Health assessment of taxi drivers in the city of Tshwane

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Tendani S. Ramukumba

2016-11-01

Conclusion: The findings implicate that the health status of taxi operators in Tshwane was a serious concern and urgent concerted effort is needed to engage in lifestyle modification of taxi drivers. The need for health promotion and formalised occupational health services was recommended.

Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand

OpenAIRE

ISHIMARU, Tomohiro; ARPHORN, Sara; JIRAPONGSUWAN, Ann

2016-01-01

In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from par...

Birds of a feather: Neanderthal exploitation of raptors and corvids.

Science.gov (United States)

Finlayson, Clive; Brown, Kimberly; Blasco, Ruth; Rosell, Jordi; Negro, Juan José; Bortolotti, Gary R; Finlayson, Geraldine; Sánchez Marco, Antonio; Giles Pacheco, Francisco; Rodríguez Vidal, Joaquín; Carrión, José S; Fa, Darren A; Rodríguez Llanes, José M

2012-01-01

The hypothesis that Neanderthals exploited birds for the use of their feathers or claws as personal ornaments in symbolic behaviour is revolutionary as it assigns unprecedented cognitive abilities to these hominins. This inference, however, is based on modest faunal samples and thus may not represent a regular or systematic behaviour. Here we address this issue by looking for evidence of such behaviour across a large temporal and geographical framework. Our analyses try to answer four main questions: 1) does a Neanderthal to raptor-corvid connection exist at a large scale, thus avoiding associations that might be regarded as local in space or time?; 2) did Middle (associated with Neanderthals) and Upper Palaeolithic (associated with modern humans) sites contain a greater range of these species than Late Pleistocene paleontological sites?; 3) is there a taphonomic association between Neanderthals and corvids-raptors at Middle Palaeolithic sites on Gibraltar, specifically Gorham's, Vanguard and Ibex Caves? and; 4) was the extraction of wing feathers a local phenomenon exclusive to the Neanderthals at these sites or was it a geographically wider phenomenon?. We compiled a database of 1699 Pleistocene Palearctic sites based on fossil bird sites. We also compiled a taphonomical database from the Middle Palaeolithic assemblages of Gibraltar. We establish a clear, previously unknown and widespread, association between Neanderthals, raptors and corvids. We show that the association involved the direct intervention of Neanderthals on the bones of these birds, which we interpret as evidence of extraction of large flight feathers. The large number of bones, the variety of species processed and the different temporal periods when the behaviour is observed, indicate that this was a systematic, geographically and temporally broad, activity that the Neanderthals undertook. Our results, providing clear evidence that Neanderthal cognitive capacities were comparable to those of

Dansk Taxi Råd har brug for et sprogkursus

DEFF Research Database (Denmark)

Riis, Helle Bach

2011-01-01

16.10. afviser formanden for Dansk Taxi Råd, John Lindbom, at det nyindførte pointsystem har til hensigt at holde indvandrere fra at blive vognmænd. I stedet siger han, at det handler om at højne fagets status og serviceniveau. Dansk Taxi Råd kan komme langt ved at forbedre sin interkulturelle...

On the uniqueness of color patterns in raptor feathers

Science.gov (United States)

Ellis, D.H.

2009-01-01

For this study, I compared sequentially molted feathers for a few captive raptors from year to year and symmetrically matched feathers (left/right pairs) for many raptors to see if color patterns of sequential feather pairs were identical or if symmetrical pairs were mirror-image identical. Feather pairs were found to be identical only when without color pattern (e.g., the all-white rectrices of Bald Eagles [Haliaeetus leucocephalus]). Complex patterns were not closely matched, but some simple patterns were sometimes closely matched, although not identical. Previous claims that complex color patterns in feather pairs are fingerprint-identical (and therefore that molted feathers from wild raptors can be used to identify breeding adults from year to year with certainty) were found to be untrue: each feather is unique. Although it is unwise to be certain of bird of origin using normal feathers, abnormal feathers can often be so used. ?? 2009 The Raptor Research Foundation, Inc.

Hubungan Upah dan Penawaran Tenaga Kerja Supir Taxi di Surabaya

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Achmad Solihin

2014-05-01

Full Text Available Utilizing 50 (fifty of taxi drivers, who has been observing around 100 (one hundred working days, this study exploring whether the prediction of Neoclassical theory or the Reference Dependence Point (RDP about income targetting are followed by the taxi drivers in Surabaya city. Neoclassical theory assume that workers will respond positively with the transitory wage change, while the Reference Dependence Point, especially income targetting predict there is negative relationship between labor supply and positive wage income transitory. RDP theory predict that workers will decide reducing their working hours or stopping to work when their wage income has exceed their targetted income. Most of the previous studies evaluate the RDP hiphotesis on taxi drivers. In this study we find that among 50 (fifty taxi drivers being observed in Surabaya following the prediction of RDP theory. The point elasticity of labor supply in respond to positive wage changing has been found on the range of -0.004 % to -0.0012%.

Value-added products from chicken feather fiber and protein

Science.gov (United States)

Fan, Xiuling

Worldwide poultry consumption has generated a huge amount of feather "waste" annually. Currently, the feather has a low value-being used for animal feed in the world. The quality of fibrous air filters depend on their main component, fibers. The main physical structure of chicken feathers is barbs which can be used directly as fibers. They have small diameter, which makes them a good choice for air filtration. The main chemical structure of chicken feathers is structural fibrous protein, keratin. Therefore, chicken feathers could potentially be used for protein fiber production. To obtain chicken feather fibers, barbs were stripped from the quills by a stripping device and separated with a blender. Some feather fibers were entangled with polyester staple fibers, and needlepunched to form a nonwoven fabric. Some feather fibers were blended with CelBond(TM) bi-component polyester as binder fibers, and pressed between two hot plates to produce thermobonded nonwovens. Whole chicken feathers were ground into powder and their keratin was reduced in water. The reduced keratin was salt precipitated, dried and dissolved in ionic liquid with/without bleach cotton. The reduced chicken feather keratin ionic liquid solutions were spun into regenerated fibers through dry-jet wet spinning. The needlepunched and thermobonded nonwovens were tested for filtration and other properties. With an increase of areal density and feather fiber composition, the air permeability of the needlepunched nonwovens decreased, and their filtration efficiency and pressure drop both increased. The case can be made that feather fibers gave fabrics better filtration at the same fabric weight, but at the expense of air permeability and pressure drop. The scrim and needlepunching process improved the filtration efficiency. Their strength depended on scrim. The hot-press process was very simple. The thermobonded nonwovens had very high air permeability. In them, there was also an inverse relation between

Prevalence of Psychoactive Drug Use by Taxi Drivers in Nigeria ...

African Journals Online (AJOL)

Aim: To ascertain the prevalence and nature of psychoactive drug use amongst taxi drivers in Nigeria. Materials and Method: A total of 192 taxi drivers in Enugu, South East Nigeria was studied using a questionnaire. Information obtained from the questionnaire included socio-demographic characteristics of the drivers, ...

Utilising excess minibus-taxi capacity for South African townships tours

NARCIS (Netherlands)

Rietjens, S.J.H.; Makoriwa, Collins; de Boer, S.J.

2006-01-01

This paper proposes an option for the utilisation of excess off-peak capacity of minibus-taxis in South Africa for township tours. The minibus-taxi system typically faces steep peak loads during rush hours with excess vehicle and person capacity available during off-hours. The advantages of the

Light diffraction through a feather

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Pérez García, Hugo;

2012-01-01

Full Text Available We have used a feather to study light diffraction, in a qualitative as well as in a quantitative manner. Experimental measurement of the separation between the bright spots obtained with a laser pointer allowed the determination of the space between feather's barbs and barbules. The results we have obtained agree satisfactorily with those corresponding to a typical feather. Due to the kind of materials, the related concepts and the experimental results, this activity becomes an excellent didactic resource suitable for studying diffraction, both in introductory undergraduate as well as in secondary school physics courses.

Taxi-Out Time Prediction for Departures at Charlotte Airport Using Machine Learning Techniques

Science.gov (United States)

Lee, Hanbong; Malik, Waqar; Jung, Yoon C.

2016-01-01

Predicting the taxi-out times of departures accurately is important for improving airport efficiency and takeoff time predictability. In this paper, we attempt to apply machine learning techniques to actual traffic data at Charlotte Douglas International Airport for taxi-out time prediction. To find the key factors affecting aircraft taxi times, surface surveillance data is first analyzed. From this data analysis, several variables, including terminal concourse, spot, runway, departure fix and weight class, are selected for taxi time prediction. Then, various machine learning methods such as linear regression, support vector machines, k-nearest neighbors, random forest, and neural networks model are applied to actual flight data. Different traffic flow and weather conditions at Charlotte airport are also taken into account for more accurate prediction. The taxi-out time prediction results show that linear regression and random forest techniques can provide the most accurate prediction in terms of root-mean-square errors. We also discuss the operational complexity and uncertainties that make it difficult to predict the taxi times accurately.

Autonomous vehicles are cost-effective when used as taxis.

Science.gov (United States)

Freedman, Isaac G; Kim, Ellen; Muennig, Peter A

2018-06-04

Autonomous vehicles (AVs) will radically re-shape the health and well-being of people in the United States in good ways and bad. We set out to estimate a reasonable time-to-adoption using cost-effectivenessmodels to estimate the point at which AVs become reasonably safe and affordable for widespread adoption. We used Waymo data (previously, Google Self-Driving Car Project) and a microsimulation model to explore projected costs and safety issues today and five years from today to get a sense of the speed of consumer adoption were AVs brought to the market. The adoption of AVs for private use was associated with an ICER of 1,396,110/QALY gained today, a figure that would decline to 173,890/QALY gained 5-years in the future. However, AV taxis are both less expensive and potentially already safer than human-piloted taxis. While AVs are not unlikely to be used a family vehicles any time soon, it would make economic sense to adopt them as taxis today. Legislation enhancing the benefits while mitigating the potential harmful health impacts of AV taxis is needed with some urgency.

Assessing and reducing fine and ultrafine particles inside Los Angeles taxis

Science.gov (United States)

Yu, Nu; Shu, Shi; Lin, Yan; Zhu, Yifang

2018-05-01

Taxi drivers and passengers are exposed to high levels of traffic-related air pollutants, but their exposures to fine (PM2.5) and ultrafine particles (UFPs) and related mitigation strategies are rarely explored. In this study, UFP and PM2.5 concentrations were monitored concurrently inside and outside of 22 taxis under different ventilation and mitigation conditions. Under realistic working conditions (no mitigation; NM), the average UFP and PM2.5 levels inside taxis were 1.46 × 104 particles/cm3 and 26 μg/m3, respectively. When the taxi ventilation was set to outside air mode and the windows kept closed, in-cabin UFP and PM2.5 concentrations are significantly associated with on-road concentrations, driving speed, and cabin air filter usage. The average in-cabin to on-roadway (I/O) ratios for UFP and PM2.5 were reduced from 0.60 to 0.75 under NM, to 0.47 and 0.52 under the most stringent mitigation strategy of keeping the windows closed and operating a high efficiency cabin air filter (WC + HECA). Among all tested taxi models, Toyota Prius exhibited the lowest UFP and PM2.5 I/O ratios under WC + HECA. Switching cabin air filters from the originally equipped manufacturer filter (OEM) to a HECA filter reduced the UFP and PM2.5 I/O ratios most effectively in Toyota Prius taxis as well.

Exploring Intracity Taxi Mobility during the Holidays for Location-Based Marketing

Directory of Open Access Journals (Sweden)

Wen-jun Wang

2017-01-01

Full Text Available Taxi mobility information can be considered as an important source of mobile location-based information for making marketing decisions. So, studying the behavioral patterns of taxis in a Chinese city during the holidays using the global positioning system (GPS can yield remarkable insights into people’s holiday travel patterns, as well as the odd-even day vehicle prohibition system. This paper studies the behavioral patterns of taxis during specific holidays in terms of pick-up and drop-off locations, travel distance, mobile step length, travel direction, and radius of gyration on the basis of GPS data. Our results support the idea of a polycentric city. It is concluded from the reporting results that there are no significant changes in the distribution of pick-up and drop-off locations, travel distance, or travel direction during holidays in comparison to work days. The results suggest that human travel by taxi has a stable regularity. However, the radius of gyration of movement by most of the taxis becomes significantly larger during holidays that indicate more long-distance travels. The current study will be helpful for location-based marketing during the holidays.

DISPAQ: Distributed Profitable-Area Query from Big Taxi Trip Data.

Science.gov (United States)

Putri, Fadhilah Kurnia; Song, Giltae; Kwon, Joonho; Rao, Praveen

2017-09-25

One of the crucial problems for taxi drivers is to efficiently locate passengers in order to increase profits. The rapid advancement and ubiquitous penetration of Internet of Things (IoT) technology into transportation industries enables us to provide taxi drivers with locations that have more potential passengers (more profitable areas) by analyzing and querying taxi trip data. In this paper, we propose a query processing system, called Distributed Profitable-Area Query ( DISPAQ ) which efficiently identifies profitable areas by exploiting the Apache Software Foundation's Spark framework and a MongoDB database. DISPAQ first maintains a profitable-area query index (PQ-index) by extracting area summaries and route summaries from raw taxi trip data. It then identifies candidate profitable areas by searching the PQ-index during query processing. Then, it exploits a Z-Skyline algorithm, which is an extension of skyline processing with a Z-order space filling curve, to quickly refine the candidate profitable areas. To improve the performance of distributed query processing, we also propose local Z-Skyline optimization, which reduces the number of dominant tests by distributing killer profitable areas to each cluster node. Through extensive evaluation with real datasets, we demonstrate that our DISPAQ system provides a scalable and efficient solution for processing profitable-area queries from huge amounts of big taxi trip data.

Analysis of the characteristics of taxi services as a prerequisite for their improvement

Directory of Open Access Journals (Sweden)

Vujić Nenad

2014-01-01

Full Text Available The expansion of services sector is the characteristics of modern and developed societies that influence national economy. Therefore, the analysis of services, as a concept and part of marketing is very significant. In this sense, the paper researches a particular service - the taxi services in the capital of Serbia. Through this research, the authors try to define the groups of customer of taxi services and their preference and attitudes. The research was performed in period May to July 2014, by direct contact with customer of taxi services. The results of research have confirmed the initial hypothesis and provide possibilities for further insight into the way of using taxi services and general circumstances that characterize them in mentioned region. On this basis, it is provided proposals for improvement of taxi services and easier outreach of target groups.

Hybrid Taxis Give Fuel Economy a Lift -Clean Cities Fleet Experiences -

Energy Technology Data Exchange (ETDEWEB)

None

2009-04-01

The hybrid taxis are able to achieve about twice the gas mileage of a conventional taxi while helping cut gasoline use and fuel costs. Tax credits and other incentives are helping both company owners and drivers make the switch to hybrids.

Valorisation of chicken feathers: Characterisation of chemical properties.

Science.gov (United States)

Tesfaye, Tamrat; Sithole, Bruce; Ramjugernath, Deresh; Chunilall, Viren

2017-10-01

The characterisation of the chemical properties of the whole chicken feather and its fractions (barb and rachis), was undertaken to identify opportunities for valorizing this waste product. The authors have described the physical, morphological, mechanical, electrical and thermal properties of the chicken feathers and related them to potential valorisation routes of the waste. However, identification of their chemical properties is necessary to complete a comprehensive description of chicken feather fractions. Hence, the chicken feathers were thoroughly characterised by proximate and ultimate analyses, elemental composition, spectroscopic analyses, durability in different solvents, burning test, and hydrophobicity. The proximate analysis of chicken feathers revealed the following compositions: crude lipid (0.83%), crude fibre (2.15%), crude protein (82.36%), ash (1.49%), NFE (1.02%) and moisture content (12.33%) whereas the ultimate analyses showed: carbon (64.47%), nitrogen (10.41%), oxygen (22.34%), and sulphur (2.64%). FTIR analysis revealed that the chicken feather fractions contain amide and carboxylic groups indicative of proteinious functional groups; XRD showed a crystallinity index of 22. Durability and burning tests confirmed that feathers behaved similarly to animal fibre. This reveals that chicken feather can be a valuable raw material in textile, plastic, cosmetics, pharmaceuticals, biomedical and bioenergy industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Global associations between birds and vane-dwelling feather mites.

Science.gov (United States)

Doña, Jorge; Proctor, Heather; Mironov, Sergey; Serrano, David; Jovani, Roger

2016-11-01

Understanding host-symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo- and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird-feather-mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12 036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used. © 2016 by the Ecological Society of America.

Flights of fear: a mechanical wing whistle sounds the alarm in a flocking bird.

Science.gov (United States)

Hingee, Mae; Magrath, Robert D

2009-12-07

Animals often form groups to increase collective vigilance and allow early detection of predators, but this benefit of sociality relies on rapid transfer of information. Among birds, alarm calls are not present in all species, while other proposed mechanisms of information transfer are inefficient. We tested whether wing sounds can encode reliable information on danger. Individuals taking off in alarm fly more quickly or ascend more steeply, so may produce different sounds in alarmed than in routine flight, which then act as reliable cues of alarm, or honest 'index' signals in which a signal's meaning is associated with its method of production. We show that crested pigeons, Ocyphaps lophotes, which have modified flight feathers, produce distinct wing 'whistles' in alarmed flight, and that individuals take off in alarm only after playback of alarmed whistles. Furthermore, amplitude-manipulated playbacks showed that response depends on whistle structure, such as tempo, not simply amplitude. We believe this is the first demonstration that flight noise can send information about alarm, and suggest that take-off noise could provide a cue of alarm in many flocking species, with feather modification evolving specifically to signal alarm in some. Similar reliable cues or index signals could occur in other animals.

Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand

Science.gov (United States)

ISHIMARU, Tomohiro; ARPHORN, Sara; JIRAPONGSUWAN, Ann

2016-01-01

In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from participant health check-up files. Self-administered questionnaires assessed demographics, driving mileage, working hours, and lifestyle. Statistical associations were analyzed using stepwise linear regression. Our results showed that obesity (p=0.007), daily alcohol drinking (p=0.003), and current or past smoking (p=0.016) were associated with higher HCT levels. While working hours were not directly associated with HCT levels in the current study, the effect on overworking is statistically arguable because most participants worked substantially longer hours. Our findings suggest that taxi drivers’ CVD risk may be increased by their unhealthy work styles. Initiatives to improve general working conditions for taxi drivers should take into account health promotion and CVD prevention. The policy of providing periodic health check-ups is important to make workers in the informal sector aware of their health status. PMID:27151439

Examining the Interaction of Taxi and Subway Ridership for Sustainable Urbanization

Directory of Open Access Journals (Sweden)

Miaoyi Li

2017-02-01

Full Text Available A transit ridership study is an essential part of sustainability, and can provide a deep understanding of people’s travel patterns for efficient transportation development and urbanization. However, there is a lack of empirical studies comparing subway and taxi services, and their interactions within a city, that is to say, the interdependent transportation networks. Incorporating new data, this study aims to examine the spatial variation of urban taxi ridership due to the impacts of a new subway line operation opened in 2014 in Wuxi, China. We examine the spatial patterns and interactions of ridership in Wuxi by integrating taxi trajectory from GPS data and subway data from continuously collected fare transactions. The results indicated that the demand for taxi and subway usage is quite elastic with respect to both location and time, and the new subway’s opening had more influence on areas adjacent to subway stations and urban center-suburban travel. Furthermore, increases in travel time and distance would increase the demand for subway, while taxi trips largely represented movements for those locations that the subway could not reach. This paper betters the understanding of travel patterns through large volumes of transportation data for sustainable urbanization policy design.

Development of the skeleton and feathers of dusky parrots (Pionus fuscus) in relation to their behaviour.

Science.gov (United States)

Harcourt-Brown, N

2004-01-10

A clutch of five dusky parrots (Pionus fuscus) was observed from hatching to fully grown. They were examined radiographically from 16 to 45 days of age, a few days before the cessation of bone growth, and the development of their feathers and their behaviour were also studied. It was observed that when growing birds were removed from the nest and placed singly on a flat surface they would stand up and walk about until restrained; normally these birds would move very little and lie in an intertwined huddle that supported their relatively weak growing skeletons. At 50 days old they would climb to the nest entrance, retreating if scared. From day 51 the parrots flapped their wings vigorously inside the nest box, and they emerged at 53 days old when nearly all their large feathers had finished growing. These findings may help to explain the high rate of juvenile osteodystrophy in hand-reared parrots; premature exercise could lead to pathological deformity of the long bones, especially the major weight-bearing bone, the tibiotarsus.

Age-class separation of blue-winged ducks

Science.gov (United States)

Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.

1995-01-01

Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual

Preliminary study on chicken feather protein-based wood adhesives

Science.gov (United States)

Zehui Jiang; Daochun Qin; Chung-Yun Hse; Monlin Kuo; Zhaohui Luo; Ge Wang; Yan Yu

2008-01-01

The objective of this preliminary study was to partially replace phenol in the synthesis of phenol-formaldehyde resin with feather protein. Feather protein–based resins, which contained one part feather protein and two parts phenol, were formulated under the conditions of two feather protein hydrolysis methods (with and without presence of phenol during...

A 'feather-trap' for collecting DNA samples from birds.

Science.gov (United States)

Maurer, Golo; Beck, Nadeena; Double, Michael C

2010-01-01

Genetic analyses of birds are usually based on DNA extracted from a blood sample. For some species, however, obtaining blood samples is difficult because they are sensitive to handling, pose a conservation or animal welfare concern, or evade capture. In such cases, feathers obtained from live birds in the wild can provide an alternative source of DNA. Here, we provide the first description and evaluation of a 'feather-trap', consisting of small strips of double-sided adhesive tape placed close to a nest with chicks, as a simple, inexpensive and minimally invasive method to collect feathers. The feather-trap was tested in tropical conditions on the Australian pheasant coucal (Centropus phasianinus). None of the 12 pairs of coucals on which the feather-trap was used abandoned the nest, and feeding rates did not differ from those of birds not exposed to a feather-trap. On average, 4.2 feathers were collected per trap over 2-5 days and, despite exposure to monsoonal rain, DNA was extracted from 71.4% of samples, albeit at low concentrations. The amount of genomic DNA extracted from each feather was sufficient to reliably genotype individuals at up to five microsatellite loci for parentage analysis. We show that a feather-trap can provide a reliable alternative for obtaining DNA in species where taking blood is difficult. It may also prove useful for collecting feather samples for other purposes, e.g. stable-isotope analysis. © 2009 Blackwell Publishing Ltd.

Considering the effects of ambient particulate matter on the lung function of motorcycle taxi drivers in Bangkok, Thailand.

Science.gov (United States)

Arphorn, Sara; Ishimaru, Tomohiro; Hara, Kunio; Mahasandana, Suwisa

2018-02-01

The motorcycle taxi drivers of Bangkok have been heavily exposed to high concentrations of PM 10 (particulate matter with an aerodynamic diameter ≤10 μm), and the impact of this on their lungs has been neither documented nor studied. This study examines the association between exposure to PM 10 and lung function decline among motorcycle taxi drivers. A cross-sectional study was conducted in Bangkok between two groups: a subject group of motorcycle taxi drivers and control group of enclosed vehicle taxi drivers. The findings of the Thailand Pollution Control Department were used to estimate the annual ambient PM 10 concentration levels in the metropolis. Pulmonary functions of motorcycle taxi drivers and enclosed vehicle taxi drivers were measured and compared using the Mann-Whitney test. Multiple linear regression analysis was applied to estimate the effects of PM 10 exposure on the lung function of motorcycle taxi drivers. A total of 1283 motorcycle taxi drivers and 600 taxi drivers were investigated. The mean forced expiratory volume in 1 sec/forced vital capacity (FEV 1 /FVC) of the motorcycle taxi drivers was significantly lower than that of the taxi drivers (P Organization (WHO) vehicular emission standards should be recognized and eventually enforced.

Research on Taxi Driver Strategy Game Evolution with Carpooling Detour

Directory of Open Access Journals (Sweden)

Wei Zhang

2018-01-01

Full Text Available For the problem of taxi carpooling detour, this paper studies driver strategy choice with carpooling detour. The model of taxi driver strategy evolution with carpooling detour is built based on prospect theory and evolution game theory. Driver stable strategies are analyzed under the conditions of complaint mechanism and absence of mechanism, respectively. The results show that passenger’s complaint mechanism can effectively decrease the phenomenon of driver refusing passengers with carpooling detour. When probability of passenger complaint reaches a certain level, the stable strategy of driver is to take carpooling detour passengers. Meanwhile, limiting detour distance and easing traffic congestion can decrease the possibility of refusing passengers. These conclusions have a certain guiding significance to formulating taxi policy.

Spatiotemporal Patterns of Carbon Emissions and Taxi Travel Using GPS Data in Beijing

Directory of Open Access Journals (Sweden)

Jinlei Zhang

2018-02-01

Full Text Available Taxis are significant contributors to carbon dioxide emissions due to their frequent usage, yet current research into taxi carbon emissions is insufficient. Emerging data sources and big data–mining techniques enable analysis of carbon emissions, which contributes to their reduction and the promotion of low-carbon societies. This study uses taxi GPS data to reconstruct taxi trajectories in Beijing. We then use the carbon emission calculation model based on a taxi fuel consumption algorithm and the carbon dioxide emission factor to calculate emissions and apply a visualization method called kernel density analysis to obtain the dynamic spatiotemporal distribution of carbon emissions. Total carbon emissions show substantial temporal variations during the day, with maximum values from 10:00–11:00 (57.53 t, which is seven times the minimum value of 7.43 t (from 03:00–04:00. Carbon emissions per kilometer at the network level are steady throughout the day (0.2 kg/km. The Airport Expressway, Ring Roads, and large intersections within the 5th Ring Road maintain higher carbon emissions than other areas. Spatiotemporal carbon emissions and travel patterns differ between weekdays and weekends, especially during morning rush hours. This research provides critical insights for taxi companies, authorities, and future studies.

Isolation and characterization of feather degrading bacteria from ...

African Journals Online (AJOL)

This study is aimed at isolating and characterizing new culturable feather degrading bacteria from soils of the University of Mauritius Farm. Bacteria that were isolated were tested for their capability to grow on feather meal agar (FMA). Proteolytic bacteria were tested for feather degradation and were further identified ...

Driving fatigue in professional drivers: a survey of truck and taxi drivers.

Science.gov (United States)

Meng, Fanxing; Li, Shuling; Cao, Lingzhi; Li, Musen; Peng, Qijia; Wang, Chunhui; Zhang, Wei

2015-01-01

Fatigue among truck drivers has been studied extensively; however, less is known regarding the fatigue experience of taxi drivers in heavily populated metropolitan areas. This study aimed to compare the differences and similarities between truck and taxi driver fatigue to provide implications for the fatigue management and education of professional drivers. A sample of 274 truck drivers and 286 taxi drivers in Beijing was surveyed via a questionnaire, which included items regarding work characteristics, fatigue experience, accident information, attitude toward fatigue, and methods of counteracting fatigue. Driver fatigue was prevalent among professional drivers, and it was even more serious for taxi drivers. Taxi drivers reported more frequent fatigue experiences and were involved in more accidents. Among the contributing factors to fatigue, prolonged driving time was the most important factor identified by both driver groups. Importantly, the reason for the engagement in prolonged driving was neither due to the lack of awareness concerning the serious outcome of fatigue driving nor because of their poor detection of fatigue. The most probable reason was the optimism bias, as a result of which these professional drivers thought that fatigue was more serious for other drivers than for themselves, and they thought that they were effective in counteracting the effect of fatigue on their driving performance. Moreover, truck drivers tended to employ methods that require stopping to counteract fatigue, whereas taxi drivers preferred methods that were simultaneous with driving. Although both driver groups considered taking a nap as one of the most effective means to address fatigue, this method was not commonly used. Interestingly, these drivers were aware that the methods they frequently used were not the most effective means to counteract fatigue. This study provides knowledge on truck and taxi drivers' characteristics in fatigue experience, fatigue attitude, and

Methodological considerations for measuring glucocorticoid metabolites in feathers

Science.gov (United States)

Berk, Sara A.; McGettrick, Julie R.; Hansen, Warren K.; Breuner, Creagh W.

2016-01-01

In recent years, researchers have begun to use corticosteroid metabolites in feathers (fCORT) as a metric of stress physiology in birds. However, there remain substantial questions about how to measure fCORT most accurately. Notably, small samples contain artificially high amounts of fCORT per millimetre of feather (the small sample artefact). Furthermore, it appears that fCORT is correlated with circulating plasma corticosterone only when levels are artificially elevated by the use of corticosterone implants. Here, we used several approaches to address current methodological issues with the measurement of fCORT. First, we verified that the small sample artefact exists across species and feather types. Second, we attempted to correct for this effect by increasing the amount of methanol relative to the amount of feather during extraction. We consistently detected more fCORT per millimetre or per milligram of feather in small samples than in large samples even when we adjusted methanol:feather concentrations. We also used high-performance liquid chromatography to identify hormone metabolites present in feathers and measured the reactivity of these metabolites against the most commonly used antibody for measuring fCORT. We verified that our antibody is mainly identifying corticosterone (CORT) in feathers, but other metabolites have significant cross-reactivity. Lastly, we measured faecal glucocorticoid metabolites in house sparrows and correlated these measurements with corticosteroid metabolites deposited in concurrently grown feathers; we found no correlation between faecal glucocorticoid metabolites and fCORT. We suggest that researchers should be cautious in their interpretation of fCORT in wild birds and should seek alternative validation methods to examine species-specific relationships between environmental challenges and fCORT. PMID:27335650

Hybrid Taxis Give Fuel Economy a Lift, Clean Cities, Fleet Experiences, April 2009 (Fact Sheet)

Energy Technology Data Exchange (ETDEWEB)

2009-04-01

Clean Cities helped Boston, San Antonio, and Cambridge create hybrid taxi programs. The hybrid taxis are able to achieve about twice the gas mileage of a conventional taxi while helping cut gasoline use and fuel costs. Tax credits and other incentives are helping both company owners and drivers make the switch to hybrids. Program leaders have learned some important lessons other cities can benefit from including learning a city's taxi structure, relaying benefits to drivers, and understanding the needs of owners.

Cost Reduction of Taxi Enterprises at the Expense of Automobile Fleet Optimization

Directory of Open Access Journals (Sweden)

Novytskyi А.V.

2016-05-01

Full Text Available Results of taxi service operation using techniques of queuing system theory have been demonstrated. It has been shown that probability of service denial is the key quality criterion of transport services for taxi services. It is expedient to use total expenditures of queuing system as target function to estimate the efficiency of taxi service. It has been determined that application of queuing theory techniques makes it possible to identify optimum value of the number of operating motor vehicles for specific environment. The value is optimum according to minimum-cost criterion.

DISPAQ: Distributed Profitable-Area Query from Big Taxi Trip Data †

Science.gov (United States)

Putri, Fadhilah Kurnia; Song, Giltae; Rao, Praveen

2017-01-01

One of the crucial problems for taxi drivers is to efficiently locate passengers in order to increase profits. The rapid advancement and ubiquitous penetration of Internet of Things (IoT) technology into transportation industries enables us to provide taxi drivers with locations that have more potential passengers (more profitable areas) by analyzing and querying taxi trip data. In this paper, we propose a query processing system, called Distributed Profitable-Area Query (DISPAQ) which efficiently identifies profitable areas by exploiting the Apache Software Foundation’s Spark framework and a MongoDB database. DISPAQ first maintains a profitable-area query index (PQ-index) by extracting area summaries and route summaries from raw taxi trip data. It then identifies candidate profitable areas by searching the PQ-index during query processing. Then, it exploits a Z-Skyline algorithm, which is an extension of skyline processing with a Z-order space filling curve, to quickly refine the candidate profitable areas. To improve the performance of distributed query processing, we also propose local Z-Skyline optimization, which reduces the number of dominant tests by distributing killer profitable areas to each cluster node. Through extensive evaluation with real datasets, we demonstrate that our DISPAQ system provides a scalable and efficient solution for processing profitable-area queries from huge amounts of big taxi trip data. PMID:28946679

The fearful feather pecker : applying the principles to practice to prevent feather pecking in laying hens

NARCIS (Netherlands)

Haas, de E.N.

2014-01-01

Billions of laying hens are kept worldwide. Severe feather pecking (SFP) is a behaviour which occurs with a high prevalence on commercial farms. SFP, the pecking and plucking of feathers of another bird, induces pain and stress and can ultimately lead to cannibalism. Moreover, SFP can occur if a

Taxi Time Prediction at Charlotte Airport Using Fast-Time Simulation and Machine Learning Techniques

Science.gov (United States)

Lee, Hanbong

2016-01-01

Accurate taxi time prediction is required for enabling efficient runway scheduling that can increase runway throughput and reduce taxi times and fuel consumptions on the airport surface. Currently NASA and American Airlines are jointly developing a decision-support tool called Spot and Runway Departure Advisor (SARDA) that assists airport ramp controllers to make gate pushback decisions and improve the overall efficiency of airport surface traffic. In this presentation, we propose to use Linear Optimized Sequencing (LINOS), a discrete-event fast-time simulation tool, to predict taxi times and provide the estimates to the runway scheduler in real-time airport operations. To assess its prediction accuracy, we also introduce a data-driven analytical method using machine learning techniques. These two taxi time prediction methods are evaluated with actual taxi time data obtained from the SARDA human-in-the-loop (HITL) simulation for Charlotte Douglas International Airport (CLT) using various performance measurement metrics. Based on the taxi time prediction results, we also discuss how the prediction accuracy can be affected by the operational complexity at this airport and how we can improve the fast time simulation model before implementing it with an airport scheduling algorithm in a real-time environment.

Greening London's black cabs: a study of driver's preferences for fuel cell taxis

International Nuclear Information System (INIS)

Mourato, Susana; Saynor, Bob; Hart, David

2004-01-01

Road transport accounts for about a quarter of all carbon emissions in the UK, highlighting the need for low carbon alternatives to current fuels and vehicles. Running on hydrogen and virtually emissions-free, fuel cell vehicles are considered to be one of the most promising ways of reducing transport-related emissions. Understanding the user benefits of fuel cell vehicles and the determinants of demand is essential for their successful penetration. This contingent valuation study investigates the preferences of London taxi drivers for driving emissions-free hydrogen fuel cell taxis, both in the short term as part of a pilot project, and in the longer term if production line fuel cell taxis become available. The results show that willingness to pay to participate in a pilot project seems to be driven mostly by drivers' expectation of personal financial gains. In contrast, however, environmental considerations are found to affect taxi drivers' longer-term vehicle purchasing decisions. The results also reveal that driving hydrogen-fuelled vehicles does not seem to raise safety concerns amongst taxi drivers

Kingfisher feathers - colouration by pigments, spongy nanostructures and thin films

NARCIS (Netherlands)

Stavenga, Doekele G.; Tinbergen, Jan; Leertouwer, Hein L.; Wilts, Bodo D.

2011-01-01

The colours of the common kingfisher, Alcedo atthis, reside in the barbs of the three main types of feather: the orange breast feathers, the cyan back feathers and the blue tail feathers. Scanning electron microscopy showed that the orange barbs contain small pigment granules. The cyan and blue

Biological treatment of chicken feather waste for improved biogas production

Institute of Scientific and Technical Information of China (English)

Gergely Forgács; Saeid Alinezhad; Amir Mirabdollah; Elisabeth Feuk-Lagerstedt; Ilona Sárvári Horwáth

2011-01-01

A two-stage system was developed which combines the biological degradation of keratin-rich waste with the production of biogas.Chicken feather waste was treated biologically with a recombinant Bacillus megaterium strain showing keratinase activity prior to biogas production.Chopped,autoclaved chicken feathers (4%,W/V) were completely degraded,resulting in a yellowish fermentation broth with a level of 0.51 mg/mL soluble proteins after 8 days of cultivation of the recombinant strain.During the subsequent anaerobic batch digestion experiments,methane production of 0.35 Nm3/kg dry feathers (i.e.,0.4 Nm3/kg volatile solids of feathers),corresponding to 80% of the theoretical value on proteins,was achieved from the feather hydrolyzates,independently of the prehydrolysis time period of 1,2 or 8 days.Cultivation with a native keratinase producing strain,Bacillus licheniformis resulted in only 0.25 mg/mL soluble proteins in the feather hydrolyzate,which then was digested achieving a maximum accumulated methane production of 0.31 Nm3/kg dry feathers.Feather hydrolyzates treated with the wild type B.megaterium produced 0.21 Nm3 CH4/kg dry feathers as maximum yield.

Investigation of in-cabin volatile organic compounds (VOCs) in taxis; influence of vehicle's age, model, fuel, and refueling.

Science.gov (United States)

Bakhtiari, Reza; Hadei, Mostafa; Hopke, Philip K; Shahsavani, Abbas; Rastkari, Noushin; Kermani, Majid; Yarahmadi, Maryam; Ghaderpoori, Afshin

2018-06-01

The air pollutant species and concentrations in taxis' cabins can present significant health impacts on health. This study measured the concentrations of benzene, toluene, ethylbenzene, xylene (BTEX), formaldehyde, and acetaldehyde in the cabins of four different taxi models. The effects of taxi's age, fuel type, and refueling were investigated. Four taxi models in 3 age groups were fueled with 3 different fuels (gas, compressed natural gas (CNG), and liquefied petroleum gas (LPG)), and the concentrations of 6 air pollutants were measured in the taxi cabins before and after refueling. BTEX, formaldehyde, and acetaldehyde sampling were actively sampled using NIOSH methods 1501, 2541, and 2538, respectively. The average BTEX concentrations for all taxi models were below guideline values. The average concentrations (±SD) of formaldehyde in Model 1 to Model 4 taxis were 889 (±356), 806 (±323), 1144 (±240), and 934 (±167) ppbv, respectively. Acetaldehyde average concentrations (±SD) in Model 1 to Model 4 taxis were 410 (±223), 441 (±241), 443 (±210), and 482 (±91) ppbv, respectively. Refueling increased the in-vehicle concentrations of pollutants primarily the CNG and LPG fuels. BTEX concentrations in all taxi models were significantly higher for gasoline. Taxi age inversely affected formaldehyde and acetaldehyde. In conclusion, it seems that refueling process and substitution of gasoline with CNG and LPG can be considered as solutions to improve in-vehicle air concentrations for taxis. Copyright © 2018. Published by Elsevier Ltd.

Respiratory symptoms and lung function in garage workers and taxi drivers.

Science.gov (United States)

Bener, A; Galadari, I; al-Mutawa, J K; al-Maskari, F; Das, M; Abuzeid, M S

1998-12-01

The aim of this study was to determine the prevalence of some respiratory symptoms and possible diseases among occupationally-exposed garage workers and taxi drivers. This study involved 158 garage workers and 165 taxi drivers, matched for age, sex, nationality and duration of employment. The mean age of 158 Indian subcontinent garage workers was 34.4 +/- 10.4 years; their mean height and weight were 167.7 +/- 6.6 cm and 72.0 +/- 12.3 kg respectively, and the mean duration of employment garage workers was 8.8 +/- 7.6 years. The mean age of 165 Indian subcontinent male taxi drivers was 34.5 +/- 7.7 years; their mean height and weight were 168.7 +/- 6.1 cm and 71.3 +/- 12.6 kg respectively; and the mean duration of employment was 7.5 +/- 5.4 years. The data on chronic respiratory symptoms showed that garage workers had higher prevalence of symptoms than taxi drivers being significantly greater for chronic phlegm, (p UAE), may be associated with the development of chronic respiratory symptoms and have effects on their daily life and health.

Safety Risk of Mobile Phone Use while Driving in Sample of Taxi Drivers

OpenAIRE

Murat Darçın; Murat Alkan

2015-01-01

Previous research has shown that mobile phone use while driving increases the risk of being involved in an accident. This paper investigates the reported frequency of taxi drivers' mobile phone use and its effects on traffic safety. A representative sample of taxi drivers was included in an interview-based survey by trained interviewers. It was found that 81% of the taxi drivers reported talking by using hand-held phone while driving. There is a relationship between the phoning while driving ...

Do spotless starlings place feathers at their nests by ultraviolet color?

Science.gov (United States)

Avilés, Jesús M.; Parejo, Deseada; Pérez-Contreras, Tomás; Navarro, Carlos; Soler, Juan J.

2010-02-01

A considerable number of bird species carry feathers to their nests. Feathers’ presence in the nests has traditionally been explained by their insulating properties. Recently, however, it has been suggested that feathers carried to the nests by females of the spotted starling ( Sturnus unicolor L.) could have an ornamental function based on their ultraviolet (300-400 nm) and human-visible longer wavelength (400-700 nm) coloration. In our population, 95.7% of feathers found inside next-boxes occupied by nesting starlings were rock dove fly feathers. Of these feathers, 82.7% were naturally positioned with their reverse side oriented toward the entrance hole and 42.4% of all found feathers were situated within the nest-cup. Here we experimentally assess the signaling function of ultraviolet coloration of feathers in nests of spotless starlings by providing nests with a number of pigeon flight feathers that were respectively treated on their obverse, reverse, both, or neither side with a UV blocker. Starlings placed 42.5% of the experimental feathers in the nest-cup irrespective of the UV block treatment. Orientation of feathers toward the entrance hole was not related with their ultraviolet radiation. However, feathers placed within the nest-cup were more likely found with their reverse side oriented toward the entrance hole confirming our correlative findings. These results suggest a minor role of ultraviolet coloration on feather location by spotless starlings.

Calidad del servicio de taxis del municipio Maracaibo

Directory of Open Access Journals (Sweden)

Joheni A. Urdaneta G.

2011-05-01

Full Text Available El presente trabajo tiene como objetivo describir la calidad del servicio de los taxis en el municipio Maracaibo, ya que los mismos forman parte del sistema de transporte urbano de la ciudad, y es un servicio público fundamental para la convivencia de la sociedad; para lograr este objetivo se realizó una adaptación del modelo SERVPERF, diseñando un instrumento tipo cuestionario, con 32 ítems en 6 dimensiones, adecuado a las características propias del servicio de taxi, con la finalidad de confirmar que los ítems de los instrumentos se correspondían con las dimensiones adaptadas se aplicó la técnica de análisis factorial resultando un nuevo instrumento con 24 ítems en 3 dimensiones. Se utilizó la escala de Likert con tres (3 alternativas de respuesta. La investigación es de tipo descriptiva y aplicada, bajo diseño no experimental de tipo transeccional descriptiva y de campo. La población quedó conformada por los usuarios de las líneas de taxis del municipio Maracaibo. Se aplicó muestreo aleatorio por conglomerado. La confiabilidad del instrumento se midió a través del coeficiente alfa de Cronbach resultando de 0,82 lo cual se considera aceptable. Los resultados revelan que la calidad del servicio de taxis del municipio Maracaibo es mediana por lo tanto este servicio es susceptible a mejoras, las cuales son necesarias para elevar la calidad de vida de los marabinos. Este resultado se obtuvo con el instrumento originalmente adaptado de 32 ítems y con el cuestionario resultante del análisis factorial, de 24 ítems; esto confirma lo apropiado de esta técnica, ya que se redujo el número de ítems y de las dimensiones originalmente adaptadas y no se encontraron diferencias significativas en los resultados con ambos instrumentos; de esta manera se puede medir la calidad del servicio de taxis en el municipio Maracaibo a través de las dimensiones: confiabilidad del servicio, socialización y responsabilidad.

Ultrastructure of the feather follicle in relation to the formation of the rachis in pennaceous feathers.

Science.gov (United States)

Alibardi, Lorenzo

2010-06-01

The present ultrastructural study on follicle of regenerating feathers of four different avian species focuses on the formation and cytology of the rachis. Epithelial cells within the bottom part of the follicle (the collar) are contacted from mesenchymal cells of the dermal papilla. The most basal part of the collar is formed by a circular epithelium containing germinal cells, while in the upper ramogenic part of the collar barb ridges are generated. Epithelial cells rest upon a basement membrane that is stretched in actively forming barb ridges among which anchored mesenchymal cells send thin elongation. This observation suggests that an intense exchange of molecules with the epithelium occurs. The process of formation of the rachis occurs by fusion of barb ridges with the nonsegmented, dorsal or anterior part of the collar. The latter becomes the rachidial ridge, the upper part of the collar where barbs form the branches of the pennaceous feather. The rachis grows and matures into an external cortical part, containing compact corneous material (feather keratin, as confirmed by immunocytochemistry), and a vacuolated medulla with a process similar to that occurring in rami of single barbs. The extension of the medulla and cortex varies along the rachis in different species. In general a thin cortex is formed in those sections of the rachis where barbs are absent, and the feather keratin positive layer increases in the basal part of the feather, the calamus.

Structural resonance and mode of flutter of hummingbird tail feathers.

Science.gov (United States)

Clark, Christopher J; Elias, Damian O; Girard, Madeline B; Prum, Richard O

2013-09-15

Feathers can produce sound by fluttering in airflow. This flutter is hypothesized to be aeroelastic, arising from the coupling of aerodynamic forces to one or more of the feather's intrinsic structural resonance frequencies. We investigated how mode of flutter varied among a sample of hummingbird tail feathers tested in a wind tunnel. Feather vibration was measured directly at ~100 points across the surface of the feather with a scanning laser Doppler vibrometer (SLDV), as a function of airspeed, Uair. Most feathers exhibited multiple discrete modes of flutter, which we classified into types including tip, trailing vane and torsional modes. Vibratory behavior within a given mode was usually stable, but changes in independent variables such as airspeed or orientation sometimes caused feathers to abruptly 'jump' from one mode to another. We measured structural resonance frequencies and mode shapes directly by measuring the free response of 64 feathers stimulated with a shaker and recorded with the SLDV. As predicted by the aeroelastic flutter hypothesis, the mode shape (spatial distribution) of flutter corresponded to a bending or torsional structural resonance frequency of the feather. However, the match between structural resonance mode and flutter mode was better for tip or torsional mode shapes, and poorer for trailing vane modes. Often, the 3rd bending structural harmonic matched the expressed mode of flutter, rather than the fundamental. We conclude that flutter occurs when airflow excites one or more structural resonance frequencies of a feather, most akin to a vibrating violin string.

[Occupational risk factors and perceptions of air pollution by motorcycle taxi drivers in Cotonou, Benin].

Science.gov (United States)

Lawin, Hervé; Ayi Fanou, Lucie; Hinson, Vikkey; Tollo, Brice; Fayomi, Benjamin; Ouendo, Edgard-Marius

Motorcycle taxis occupy a major place in urban transport. Motorcycle taxi drivers are exposed to occupational risk factors (ORF) including air pollution. The objective of this study was to evaluate these ORF among motorcycle taxi drivers and their perceptions of air pollution. This mixed study was conducted on motorcycle taxi drivers in Cotonou. The qualitative study was based on focus groups concerning 16 items from the Participatory Occupational Risk Screening Guide (DEPARIS) until saturation and after triangulation of data. The quantitative study consisted of administering a questionnaire addressing socioeconomic and demographic characteristics, cardiopulmonary diseases, and perception of air -pollution risk factors among 397 Cotonou motorcycle taxi drivers. Drivers perceived poor road conditions, effort and handling, and lack of social security as unsatisfactory ORF. Their mean age was 40.95 ± 8.75 years and 45.84% had primary -education. They had been working as motorcycle taxi drivers for an average of 134.95 ± 101.53 months with an average income of FCFA 3138 ± 1238. These occupational factors were significantly associated with cardiopulmonary disorders, observed in 63.2% of drivers. Less than 1/3 of drivers felt that air pollution affected their personal health. Motorcycle taxi drivers have a poor perception of ORF and the severity of exposure to air pollution in this occupation. There is a need to take action to promote the health of this population.

Age determination of blue-winged teal

Science.gov (United States)

Dane, C.W.

1968-01-01

Primary feather length, markings on the greater secondary coverts, and the degree of bill spotting were evaluated as characters for use in the spring to distinguish first-year, blue-winged teal (Anas discors) females from older ones. The length of the 10th primary feather did not prove suitable to separate different aged females. Extreme primary lengths might be used to determine the age of some males. In females that have been through a postnuptial molt the greater secondary coverts have a more symmetrical, and more acutely angled, white, inverted 'V'-marking. Any female with a 'V' subjectively classified as good has gone through at least one postnuptial molt, and a female with no sign of a 'V' on the coverts is a juvenile or yearling before her first postnuptial molt. By measuring the longest bill spot on the upper mandible of each known-age female, it was possible to determine the age of some female teal. Because the spots fade during the breeding season, no lower size limit could be set to delineate first-year females at that time of year, but any nest-trapped hen with a spot longer than 10 mm was considered to be older than 1 year. Upper and lower limits were also established to distinguish some yearlings and 2-year-olds in the fall.

Molecular Biology of Feather Morphogenesis: A Testable Model for Evo-Devo Research

Science.gov (United States)

WIDELITZ, RANDALL B.; JIANG, TING XIN; YU, MINGKE; SHEN, TED; SHEN, JEN-YEE; WU, PING; YU, ZHICAO; CHUONG, CHENG-MING

2015-01-01

Darwin’s theory describes the principles that are responsible for evolutionary change of organisms and their attributes. The actual mechanisms, however, need to be studied for each species and each organ separately. Here we have investigated the mechanisms underlying these principles in the avian feather. Feathers comprise one of the most complex and diverse epidermal organs as demonstrated by their shape, size, patterned arrangement and pigmentation. Variations can occur at several steps along each level of organization, leading to highly diverse forms and functions. Feathers develop gradually during ontogeny through a series of steps that may correspond to the evolutionary steps that were taken during the phylogeny from a reptilian ancestor to birds. These developmental steps include 1) the formation of feather tract fields on the skin surfaces; 2) periodic patterning of the individual feather primordia within the feather tract fields; 3) feather bud morphogenesis establishing anterio - posterior (along the cranio - caudal axis) and proximo - distal axes; 4) branching morphogenesis to create the rachis, barbs and barbules within a feather bud; and 5) gradual modulations of these basic morphological parameters within a single feather or across a feather tract. Thus, possibilities for variation in form and function of feathers occur at every developmental step. In this paper, principles guiding feather tract formation, distributions of individual feathers within the tracts and variations in feather forms are discussed at a cellular and molecular level. PMID:12949772

Decreased hydrophobicity of iridescent feathers: a potential cost of shiny plumage.

Science.gov (United States)

Eliason, Chad M; Shawkey, Matthew D

2011-07-01

Honest advertisement models posit that sexually selected traits are costly to produce, maintain or otherwise bear. Brightly coloured feathers are thought to be classic examples of these models, but evidence for a cost in feathers not coloured by carotenoid pigments is scarce. Unlike pigment-based colours, iridescent feather colours are produced by light scattering in modified feather barbules that are characteristically flattened and twisted towards the feather surface. These modifications increase light reflectance, but also expose more surface area for water adhesion, suggesting a potential trade-off between colour and hydrophobicity. Using light microscopy, spectrometry, contact angle goniometry and self-cleaning experiments, we show that iridescent feathers of mallards, Anas platyrhynchos, are less hydrophobic than adjacent non-iridescent feathers, and that this is primarily caused by differences in barbule microstructure. Furthermore, as a result of this decreased hydrophobicity, iridescent feathers are less efficient at self-cleaning than non-iridescent feathers. Together, these results suggest a previously unforeseen cost of iridescent plumage traits that may help to explain the evolution and distribution of iridescence in birds.

Switching from motorcycle taxi to walking: A case study of transit station access in Bangkok, Thailand

Directory of Open Access Journals (Sweden)

Pornraht Pongprasert

2017-12-01

Full Text Available This study aims to find the factors affecting residents near transit stations within 1000 m, who are referred to as transit-oriented development (TOD residents, to reduce motorcycle taxi use and encourage walking to stations. These two modes of commuting are the most popular among over 85% of residents. However, motorcycle taxis are the main pedestrian barriers that hinder easy access and walkability in TODs of Bangkok, because they ride, stop, and provide services on sidewalks. From 2013 to 2015, these problems substantially increased the number of motorcycle taxis that are not willing and able to follow the rules. The increasing number of pedestrian accidents on sidewalks is related to the increase in the number of motorcycle taxis. According to a survey on pedestrian safety with 249 respondents, over 25% of walkers feel unsafe to walk, while 40% of motorcycle-taxi users riding to stations do not walk because they are afraid of accidents. In modal split, the share of walking reduces from 76% for areas < 500 m, to 25% for areas between 500 and 1000 m from transit stations, respectively. Hence, the number of motorcycle taxis in the 500–1000 m range is twice as high compared to that within the 500 m area. If motorcycle taxi users would accept a longer walking distance to station by 36 m or would be willing to walk to the station within 9.15 min, 54% of them may switch to walking to stations. Moreover, based on the estimation results of the logistic regression models, middle-adult aged residents, office employees, residents owning a car, and people living far from stations are less likely to walk. Average income households and commuters during non-peak hours tend to use motorcycle taxis more. On the other hand, residents living far from stations tend to use motorcycle taxis less, because most of the motorcycle taxi services are located near transit stations. Keywords: Transit accessibility, Pedestrian, Walkability

Multi-Isotopic (δ2H, δ13C, δ15N Tracing of Molt Origin for Red-Winged Blackbirds Associated with Agro-Ecosystems.

Directory of Open Access Journals (Sweden)

Scott J Werner

Full Text Available We analyzed stable-hydrogen (δ2H, carbon (δ13C and nitrogen (δ 15N isotope ratios in feathers to better understand the molt origin and food habits of Red-winged Blackbirds (Agelaius phoeniceus near sunflower production in the Upper Midwest and rice production in the Mid-South of the United States. Outer primary feathers were used from 661 after-second-year (ASY male blackbirds collected in Minnesota, Montana, North Dakota and South Dakota (spring collection, and Arkansas, Louisiana, Mississippi, Missouri and Texas (winter collection. The best-fit model indicated that the combination of feather δ2H, δ13C and δ15N best predicted the state of sample collections and thus supported the use of this approach for tracing molt origins in Red-winged Blackbirds. When considering only birds collected in spring, 56% of birds were classified to their collection state on the basis of δ2H and δ13C alone. We then developed feather isoscapes for δ13C based upon these data and for δ2H based upon continental patterns of δ2H in precipitation. We used 81 birds collected at the ten independent sites for model validation. The spatially-explicit assignment of these 81 birds to the δ2H isoscape resulted in relatively high rates (~77% of accurate assignment to collection states. We also modeled the spatial extent of C3 (e.g. rice, sunflower and C4 (corn, millet, sorghum agricultural crops grown throughout the Upper Midwest and Mid-South United States to predict the relative use of C3- versus C4-based foodwebs among sampled blackbirds. Estimates of C3 inputs to diet ranged from 50% in Arkansas to 27% in Minnesota. As a novel contribution to blackbird conservation and management, we demonstrate how such feather isoscapes can be used to predict the molt origin and interstate movements of migratory blackbirds for subsequent investigations of breeding biology (e.g. sex-specific philopatry, agricultural depredation, feeding ecology, physiology of migration and

Multi-Isotopic (δ2H, δ13C, δ15N) Tracing of Molt Origin for Red-Winged Blackbirds Associated with Agro-Ecosystems.

Science.gov (United States)

Werner, Scott J; Hobson, Keith A; Van Wilgenburg, Steven L; Fischer, Justin W

2016-01-01

We analyzed stable-hydrogen (δ2H), carbon (δ13C) and nitrogen (δ 15N) isotope ratios in feathers to better understand the molt origin and food habits of Red-winged Blackbirds (Agelaius phoeniceus) near sunflower production in the Upper Midwest and rice production in the Mid-South of the United States. Outer primary feathers were used from 661 after-second-year (ASY) male blackbirds collected in Minnesota, Montana, North Dakota and South Dakota (spring collection), and Arkansas, Louisiana, Mississippi, Missouri and Texas (winter collection). The best-fit model indicated that the combination of feather δ2H, δ13C and δ15N best predicted the state of sample collections and thus supported the use of this approach for tracing molt origins in Red-winged Blackbirds. When considering only birds collected in spring, 56% of birds were classified to their collection state on the basis of δ2H and δ13C alone. We then developed feather isoscapes for δ13C based upon these data and for δ2H based upon continental patterns of δ2H in precipitation. We used 81 birds collected at the ten independent sites for model validation. The spatially-explicit assignment of these 81 birds to the δ2H isoscape resulted in relatively high rates (~77%) of accurate assignment to collection states. We also modeled the spatial extent of C3 (e.g. rice, sunflower) and C4 (corn, millet, sorghum) agricultural crops grown throughout the Upper Midwest and Mid-South United States to predict the relative use of C3- versus C4-based foodwebs among sampled blackbirds. Estimates of C3 inputs to diet ranged from 50% in Arkansas to 27% in Minnesota. As a novel contribution to blackbird conservation and management, we demonstrate how such feather isoscapes can be used to predict the molt origin and interstate movements of migratory blackbirds for subsequent investigations of breeding biology (e.g. sex-specific philopatry), agricultural depredation, feeding ecology, physiology of migration and sensitivity to

Feather growth influences blood mercury level of young songbirds.

Science.gov (United States)

Condon, Anne M; Cristol, Daniel A

2009-02-01

Dynamics of mercury in feathers and blood of free-living songbirds is poorly understood. Nestling eastern bluebirds (Sialia sialis) living along the mercury-contaminated South River (Virginia, USA) had blood mercury levels an order of magnitude lower than their parents (nestling: 0.09 +/- 0.06 mg/kg [mean +/- standard deviation], n = 156; adult: 1.21 +/- 0.57 mg/kg, n = 86). To test whether this low blood mercury was the result of mercury sequestration in rapidly growing feathers, we repeatedly sampled free-living juveniles throughout the period of feather growth and molt. Mean blood mercury concentrations increased to 0.52 +/- 0.36 mg/kg (n = 44) after the completion of feather growth. Some individuals had reached adult blood mercury levels within three months of leaving the nest, but levels dropped to 0.20 +/- 0.09 mg/kg (n = 11) once the autumn molt had begun. Most studies of mercury contamination in juvenile birds have focused on recently hatched young with thousands of rapidly growing feathers. However, the highest risk period for mercury intoxication in young birds may be during the vulnerable period after fledging, when feathers no longer serve as a buffer against dietary mercury. We found that nestling blood mercury levels were not indicative of the extent of contamination because a large portion of the ingested mercury ended up in feathers. The present study demonstrates unequivocally that in songbirds blood mercury level is influenced strongly by the growth and molt of feathers.

Assessment of exposure to whole body vibration in Yazd city taxi drivers

Directory of Open Access Journals (Sweden)

F Samoori sakhvidi

2016-11-01

Full Text Available Assessment of exposure to whole body vibration in Yazd city taxi drivers Samoori-Sakhvidi F (MSc* Barkhordari A (PhD** Dehghani A (PhD*** Tavakoli-Manesh S (MSc**** *Corresponding Author: MSc Student in Department of Occupational Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran ** Professor, Department of Occupational Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran *** Professor, Department of Statistics and Epidemiology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran **** MSc Student in Department of Occupational Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Abstract Introduction: One of the most common sources of whole body vibration are vehicles in which the driver is exposed to vibration caused by the vehicle and the road. Including the people who continuously exposure to whole-body vibration can be noted to taxi drivers. Taxi drivers during their work shift Encountered with numerous deleterious effects such as noise, vibration, air pollution, and psychological stress and long work shifts. Long-term exposure to whole body vibration in the taxi drivers can communicate with adverse effects such as reduce perception, annoyance, disturbance of vision and fine motor tasks, spinal cord injury, damage to the digestive and reproductive systems. The purpose of this study was cross - sectional study of whole body vibration exposure in Yazd city taxi drivers. Methods: This study was designed to evaluate exposure to whole body vibration in taxi drivers, vibration measurement Was carried out in 80 taxi from 3 vehicle (Samand-Peugeot 405 and Pridein 3 mileage groups, with 63 male drivers and 17 female drivers. parameters Including the vibration Weighing the acceleration frequency (rms, Equivalent acceleration (Aeq and vibration doseVDV in 3-axis was recorded. The results obtained were compared with the values recommended by the standard (ISO 2631-1. Results: The mean (rms acceleration

Theory of the development of curved barbs and their effects on feather morphology.

Science.gov (United States)

Feo, Teresa J; Simon, Emma; Prum, Richard O

2016-08-01

Feathers exhibit an extraordinary diversity of shapes, which are used by birds to accomplish a diverse set of functions. Pennaceous feathers have a double branched morphology that develops from a tube of epidermis, and variation in branch geometry determines feather shape. Feather development is both complex (i.e., a simple developmental modification can have multiple effects on mature feather shape), and redundant (i.e., different developmental modifications can create the same shape). Due to this, it is not readily apparent how different feather shapes develop. In many feathers, barbs are not straight, but instead curve in toward, or away, from the feather tip. Barb curvature can affect the shape of mature feathers but the development of curved barbs is unknown. Previous research has hypothesized that barb curvature could develop either during the helical growth of barb ridges in the tubular feather germ, or during barb angle expansion as the feather unfurls from the sheath. To better understand the development of curved barbs and their effects on mature feathers we present a theoretical model of curved barb development and test the model with empirical investigations of feathers. We find that curved barbs affect many aspects of feather morphology including vane width, barb length, and barb spacing. In real feathers, curved barbs can develop both during helical barb ridge growth and during barb angle expansion, with most of the observed curvature due to barb angle expansion. Our results demonstrate that barb angle expansion as a feather unfurls from the sheath is a complex and dynamic process that plays an important role in determining the shape and structure of mature feathers. Curved barbs create heterogeneity in barb geometry within the feather vane, which could have important implications for aerodynamic function and the development of within feather pigmentation patterns. J. Morphol. 277:995-1013, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley

Mutual ornamentation, sexual selection, and social dominance in the black swan

NARCIS (Netherlands)

Kraaijeveld, K; Gregurke, J; Hall, C; Komdeur, J; Mulder, RA

We investigated the adaptive significance of a sexually monomorphic ornament in the black swan Cygnus atratus. Both sexes grow curled feathers on their wings (range 7-22 curled feathers per wing), which are displayed prominently in a range of social interactions. The number of curled feathers

Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

Science.gov (United States)

Viegas, Carla; Monteiro, Ana; Dos Santos, Mateus; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Quintal Gomes, Anita; Marchand, Geneviève; Lacombe, Nancy; Viegas, Susana

2018-07-01

Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m 2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1-31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting. Copyright © 2018 Elsevier Inc. All rights reserved.

Kingfisher feathers - colouration by pigments, spongy nanostructures and thin films

OpenAIRE

Stavenga, Doekele G.; Tinbergen, Jan; Leertouwer, Hein L.; Wilts, Bodo D.

2011-01-01

The colours of the common kingfisher, Alcedo atthis, reside in the barbs of the three main types of feather: the orange breast feathers, the cyan back feathers and the blue tail feathers. Scanning electron microscopy showed that the orange barbs contain small pigment granules. The cyan and blue barbs contain spongy nanostructures with slightly different dimensions, causing different reflectance spectra. Imaging scatterometry showed that the pigmented barbs create a diffuse orange scattering a...

Prevalence and factors associated with road traffic crash among taxi drivers in Hanoi, Vietnam.

Science.gov (United States)

La, Quang Ngoc; Lee, Andy H; Meuleners, Lynn B; Van Duong, Dat

2013-01-01

Injury due to road traffic crash is a major cause of ill health and premature deaths in developing countries. Taxis provide a main mode of public transport in Vietnam but there has been little research on the risk of crash for taxi drivers. This retrospective study collected information on taxi crashes for the period 2006-2009 by interviewing drivers from five taxi companies in Hanoi, Vietnam, using a structured questionnaire. Of the total 1214 participants recruited, 276 drivers reported at least one crash, giving an overall crash prevalence of 22.7%. Among the crashed group, 50 drivers (18.1%) were involved in two to four crashes. Logistic regression analysis further identified age of driver, type of driving licence, employment status, perceived sufficiency of income, seat-belt usage, and traffic infringement history to be significantly associated with the crash risk. Further prospective and qualitative studies are recommended to provide detailed crash characteristics as well as behaviour and perception of taxi drivers, so that an effective intervention can be developed to improve road safety and to prevent injury of these commercial drivers. Copyright © 2012 Elsevier Ltd. All rights reserved.

Developing a Decision-Support-Tool for an Air Taxi Service in Western Europe

NARCIS (Netherlands)

Van Wee, G.P.; Van Nes, R.; Van Duin, J.H.R.; Sengers, P.; Ghijs, S.S.A.

2008-01-01

This paper is a research proposal to develop a tool to analyze logistic concepts of the air taxi service of Aeolus Aviation in different scenarios. Based on this analysis recommendations can be done for a suitable logistic concept for Aeolus. Based on background analysis of the air taxi service

Three-wheeled scooter taxi: A safety analysis

Indian Academy of Sciences (India)

Three-wheel scooter taxis (TSR) form an essential part of public transport for the urban ... These low cost vehicles will remain a major mode of travel in the South Asian region ... commercial codes can be avoided for computational efficiency.

The morphology of neoptile feathers: ancestral state reconstruction and its phylogenetic implications.

Science.gov (United States)

Foth, Christian

2011-04-01

Avian neoptile feathers are defined as the first feather generation, which covers the chick after hatching, and usually described as simple structures consisting of numerous downy barbs which are radially symmetrically arranged and come together in a short calamus. In contrast, in some birds (e.g., Anas platyrhynchos, Dromaius novaehollandiae) the neoptile feathers have a prominent rhachis, and therefore display clear bilateral symmetry. Because the symmetrical variety found in neoptile feathers is poorly understood, their morphology was studied in a more comprehensive and phylogenetic approach. Neoptile body feathers from over 22 bird species were investigated using light microscopy, SEM, and MicroCT. Characters such as an anterior-posterior axis, a central rhachis, medullary cells, and structure of the calamus wall were defined and mapped onto recent phylogenetic hypotheses for extant birds. It can be shown that bilaterally symmetric neoptile feathers (with a solid calamus wall) were already present in the stem lineage of crown-group birds (Neornithes). In contrast, simple radially symmetric neoptile feathers (with a fragile calamus wall) are an apomorphic character complex for the clade Neoaves. The simple morphology of this feather type may be the result of a reduced period of development during embryogenesis. To date, embryogenesis of neoptile feathers from only a few bird species was used as a model to reconstruct feather evolution. Because this study shows that the morphology of neoptile feathers is more diverse and even shows a clear phylogenetic signal, it is necessary to expand the spectrum of "model organisms" to species with bilaterally symmetric neoptile feathers and compare differences in the frequency of feather development from a phylogenetic point of view. Copyright © 2011 Wiley-Liss, Inc.

Both feather peckers and victims are more asymmetrical than control hens

DEFF Research Database (Denmark)

Machado Tahamtani, Fernanda; Forkman, Björn; Hinrichsen, Lena Karina

2017-01-01

Feather pecking is the major welfare issue facing the egg farming industry worldwide. Previous research has found a relationship between cannibalistic behaviour, fluctuating asymmetry of bilateral traits (FA) and body weight in laying hens. As cannibalism is linked to severe feather pecking......, it could be suggested that a relationship between feather pecking, FA and body weight also exists. The purpose of this study was to analyse the association between feather pecking behaviour and a) FA, b) body weight and c) comb size in laying hens. Sixty-four laying hens were categorised as feather peckers...

Fearfulness and feather damage in laying hens divergently selected for high and low feather pecking

DEFF Research Database (Denmark)

Rodenburg, T Bas; de Haas, Elske N; Nielsen, Birte Lindstrøm

2010-01-01

Feather pecking (FP) remains a major welfare and economic problem in laying hens. FP has been found to be related to other behavioural characteristics, such as fearfulness. There are indications that fearful birds are more likely to develop FP. Furthermore, FP can lead to increased fearfulness...... in the victims. To investigate further the relationship between FP and fearfulness, feather damage and behavioural fear responses were recorded in three White Leghorn lines of laying hens: a line selected for high FP (HFP line), a line selected for low FP (LFP line) and an unselected control line (10th...... in fear responses between the HFP and LFP lines were not found, neither in the TI-test, nor in the HA or NO test. As expected, birds from the HFP line had considerably more feather damage than birds from the LFP line and birds from the unselected control line were intermediate. Cages that withdrew from...

Safety Risk of Mobile Phone Use while Driving in Sample of Taxi Drivers

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Murat Darçın

2015-08-01

Full Text Available Previous research has shown that mobile phone use while driving increases the risk of being involved in an accident. This paper investigates the reported frequency of taxi drivers' mobile phone use and its effects on traffic safety. A representative sample of taxi drivers was included in an interview-based survey by trained interviewers. It was found that 81% of the taxi drivers reported talking by using hand-held phone while driving. There is a relationship between the phoning while driving and drivers' self-reported involvement in a dangerous situation. It is clear that the use of mobile phone while driving is an important traffic safety issue.

Holding tight on feathers - structural specializations and attachment properties of the avian ectoparasite Crataerina pallida (Diptera, Hippoboscidae).

Science.gov (United States)

Petersen, Dennis S; Kreuter, Nils; Heepe, Lars; Büsse, Sebastian; Wellbrock, Arndt H J; Witte, Klaudia; Gorb, Stanislav N

2018-04-30

The louse fly Crataerina pallida is an obligate blood-sucking ecto-parasite of the common swift Apus apus Due to reduction of the wings, C. pallida is unable to fly, thus an effective and reliable attachment to their host's plumage is of outmost importance. Its attachment system shows several modifications in comparison to other calyptrate flies. The most prominent ones are the large tridentate claws and the dichotomously shaped setae located on the pulvilli. Based on data from morphological analysis, confocal laser scanning microscopy, cryo-scanning electron microscopy and traction force experiments, performed on native (feathers) as well as artificial substrates (glass, epoxy-resin and silicone rubber), we showed that the entire attachment system is highly adapted to the fly's lifestyle as an ectoparasite. The claws in particular are the main contributor to strong attachment to the host. Resulting attachment forces on feathers make it impossible to detach C. pallida without damage of feathers or legs of the fly itself. Well-developed pulvilli are responsible for the attachment to smooth surfaces. Both dichotomously shaped setae and high setal density explain high safety factors observed on smooth substrates. For the first time, we demonstrated a material gradient within the setae with soft, resilin dominated apical tips and stiff, more sclerotized bases in Diptera. The empodium seems not to be directly involved in the attachment process, but it might operate as a cleaning device and may be essential to maintain the functionality of the entire attachment system. © 2018. Published by The Company of Biologists Ltd.

76 FR 33639 - Safety Zone; New York Water Taxi 10th Anniversary Fireworks

Science.gov (United States)

2011-06-09

...-AA00 Safety Zone; New York Water Taxi 10th Anniversary Fireworks, Upper New York Bay, Red Hook, NY... New York Water Taxi. The fireworks will commence at 9 p.m. on June 21, 2011 and will last... CFR Part 165 Harbors, Marine safety, Navigation (water), Reporting and recordkeeping requirements...

Eggshell bacterial load is related to antimicrobial properties of feathers lining barn swallow nests.

Science.gov (United States)

Peralta-Sánchez, Juan Manuel; Soler, Juan José; Martín-Platero, Antonio Manuel; Knight, Rob; Martínez-Bueno, Manuel; Møller, Anders Pape

2014-02-01

The use of feathers to line bird's nests has traditionally been interpreted as having a thermoregulatory function. Feather-degrading bacteria growing on feathers lining nests may have antimicrobial properties, which may provide an additional benefit to lining nests with feathers. We test the hypothesis that the production of antimicrobial substances by feather bacteria affects the microbiological environment of the nest, and therefore the bacterial density on eggshells and, indirectly, hatching success. These effects would be expected to differ between nests lined with pigmented and white feathers, because bacteria grow differently on feathers of different colors. We experimentally manipulated the composition of pigmented and unpigmented feathers in nests of the barn swallow (Hirundo rustica) and studied the antimicrobial properties against the keratin-degrading bacterium Bacillus licheniformis of bacteria isolated from feathers of each color. Analyzed feathers were collected at the end of the incubation period, and antimicrobial activity was defined as the proportion of bacteria from the feathers that produce antibacterial substances effective against B. licheniformis. Our experimental manipulation affected antimicrobial activity, which was higher in nests with only white feathers at the beginning of incubation. Moreover, white feathers showed higher antimicrobial activity than black ones. Interestingly, antimicrobial activity in feathers of one of the colors correlated negatively with bacterial density on feather of the opposite color. Finally, antimicrobial activity of white feathers was negatively related to eggshell bacterial load. These results suggest that antimicrobial properties of feathers in general and of white feathers in particular affect the bacterial environment in nests. This environment in turn affects the bacterial load on eggshells, which may affect hatching success.

On-road emission characteristics of CNG-fueled bi-fuel taxis

Science.gov (United States)

Yao, Zhiliang; Cao, Xinyue; Shen, Xianbao; Zhang, Yingzhi; Wang, Xintong; He, Kebin

2014-09-01

To alleviate air pollution and lessen the petroleum demand from the motor vehicle sector in China, natural gas vehicles (NGVs) have been rapidly developed over the last several years. However, the understanding of the real-world emissions of NGVs is very limited. In this study, the emissions from 20 compressed-natural-gas-fueled bi-fuel taxis were measured using a portable emission measurement system (PEMS) under actual driving conditions in Yichang, China. The emission characteristics of the tested vehicles were analyzed, revealing that the average CO2, CO, HC and NOx emissions from the tested compressed-natural-gas (CNG) taxis under urban driving conditions were 1.6, 4.0, 2.0 and 0.98 times those under highway road conditions, respectively. The CO, HC and NOx emissions from Euro 3 CNG vehicles were approximately 40%, 55% and 44% lower than those from Euro 2 vehicles, respectively. Compared with the values for light-duty gasoline vehicles reported in the literature, the CO2 and CO emissions from the tested CNG taxis were clearly lower; however, significant increases in the HC and NOx emissions were observed. Finally, we normalized the emissions under the actual driving cycles of the entire test route to the New European Driving Cycle (NEDC)-based emissions using a VSP modes method developed by North Carolina State University. The simulated NEDC-based CO emissions from the tested CNG taxis were better than the corresponding emissions standards, whereas the simulated NEDC-based HC and NOx emissions greatly exceeded the standards. Thus, more attention should be paid to the emissions from CNG vehicles. As for the CNG-fueled bi-fuel taxis currently in use, the department of environmental protection should strengthen their inspection and supervision to reduce the emissions from these vehicles. The results of this study will be helpful in understanding and controlling emissions from CNG-fueled bi-fuel vehicles in China.

Isolation and characterization of feather degrading bacteria from ...

African Journals Online (AJOL)

puchooa

2012-09-04

Sep 4, 2012 ... In Mauritius, the annual production of poultry meat is about 50,000 tonnes ... processing of feathers for the production of feather meal, instead of chemical ..... digestibility by bacterial keratinase as a feed additive. FASEB J.

Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles

Directory of Open Access Journals (Sweden)

Sutthiphong Srigrarom

2015-05-01

resonance phenomenon of a two-degree of freedom elastic system, that is, the wing is supported by the springs for flapping and feathering motions. Being oscillated close to the resonance frequency of the system, only by the torque in flapping motion, the amplitude gained is a few times higher than that of normal case. The first prototype was made from acrylic using a laser cutting machine. The wings were made up of carbon rods and kite material Ripstop. First test showed that the wings were too heavy for the mechanism to work. The third prototype was a smaller single gear crank design which was fabricated using a 3D printer. Initial test proved that the second prototype could withstand the high frequency flapping and near resonance amplitude as designed. With remote control, the third prototype was able to take off, climb, cruise and land in flapping mode successfully.

Short barb: a feather structure mutation in Japanese quail.

Science.gov (United States)

Fulton, J E; Roberts, C W; Nichols, C R; Cheng, K M

1982-12-01

A type of feather structure abnormality in Japanese quail resulting in shortened barbs on contour feathers was found to be controlled by a single autosomal recessive gene, sh (short barb). The mutation was first identified in a full-sib family from the University of British Columbia wild type line. Unlike other feather structure mutations in Japanese quail reported previously in literature, the short barb mutation is not associated with poor reproduction.

Detecting Traffic Anomalies in Urban Areas Using Taxi GPS Data

Directory of Open Access Journals (Sweden)

Weiming Kuang

2015-01-01

Full Text Available Large-scale GPS data contain hidden information and provide us with the opportunity to discover knowledge that may be useful for transportation systems using advanced data mining techniques. In major metropolitan cities, many taxicabs are equipped with GPS devices. Because taxies operate continuously for nearly 24 hours per day, they can be used as reliable sensors for the perceived traffic state. In this paper, the entire city was divided into subregions by roads, and taxi GPS data were transformed into traffic flow data to build a traffic flow matrix. In addition, a highly efficient anomaly detection method was proposed based on wavelet transform and PCA (principal component analysis for detecting anomalous traffic events in urban regions. The traffic anomaly is considered to occur in a subregion when the values of the corresponding indicators deviate significantly from the expected values. This method was evaluated using a GPS dataset that was generated by more than 15,000 taxies over a period of half a year in Harbin, China. The results show that this detection method is effective and efficient.

Taxi ! méthode de français : niveau 3

CERN Document Server

Johnson, Anne-Marie

2004-01-01

Taxi ! 3 est une méthode interactive, qui développe non seulement les connaissances, mais aussi les savoir-faire et les savoir-être de l'apprenant, à l'écrit comme à l'oral. La méthode est très simple à utiliser : une leçon = une double page. Taxi ! 3 couvre le niveau Bl du Cadre européen commun de référence pour l'apprentissage, l'enseignement et l'évaluation des langues. La méthode permet de se préparer aux épreuves A3 et A4 du DELF 1er degré. Une progression et des contenus fonctionnels et langagiers solides permettent à l'apprenant d'atteindre rapidement une autonomie en français dans des situations de la vie courante. Taxi ! 3 permet de mieux connaître la France d'aujourd'hui et les comportements des Français à travers une grande variété de documents authentiques (écrit et audio).

Characterizing urban structure using taxi GPS data

NARCIS (Netherlands)

Zheng, Zhong; Zhou, Suhong; Rasouli, S.; Timmermans, H.J.P.

2014-01-01

Scholars have explored urban structure from many perspectives. Developments in ICT have made it possible to discover spatial patterns in activities using big data. The identified patterns allow us to better understand urban structure. This chapter reports the collection of taxi GPS records for a

Ovarian hemangiosarcoma in an orange-winged Amazon parrot (Amazona amazonica).

Science.gov (United States)

Mickley, Kimberly; Buote, Melanie; Kiupel, Matti; Graham, Jennifer; Orcutt, Connie

2009-03-01

A 25-year-old intact female orange-winged Amazon parrot (Amazona amazonica) presented for a 2-week history of straining to defecate, lethargy, open-beak breathing, decreased vocalization, and ruffled feathers. On physical examination, the parrot had a heart murmur, increased air sac and lung sounds, open-beak breathing, increased respiratory rate and effort, and coelomic distension. An ultrasound revealed intracoelomic fluid, and hemorrhagic fluid was aspirated from the coelom. Cytologic analysis indicated hemocoelom. Pericardial effusion was observed during the sonogram, and pericardiocentesis was performed. The bird was euthanatized upon the owner's request because of a poor prognosis. At necropsy, several masses that involved the ovary and oviduct were observed, as well as a thickened pericardium and a thickened, fibrinous epicardium. Results of a histopathologic examination of the masses that involved the reproductive tract revealed ovarian hemangiosarcoma, which was confirmed by immunohistochemical staining. To our knowledge, ovarian hemangiosarcoma has not been reported in a psittacine species, nor has immunohistochemistry confirmed ovarian hemangiosarcoma in avian species, specifically in an orange-winged Amazon parrot.

[Association between psychosocial aspects of work and quality of life among motorcycle taxi drivers].

Science.gov (United States)

Teixeira, Jules Ramon Brito; Boery, Eduardo Nagib; Casotti, Cezar Augusto; Araújo, Tânia Maria de; Pereira, Rafael; Ribeiro, Ícaro José Santos; Rios, Marcela Andrade; Amorim, Camila Rego; Moreira, Ramon Missias; Boery, Rita Narriman Silva de Oliveira; Sales, Zenilda Nogueira

2015-01-01

This study aimed to evaluate the quality of life of motorcycle taxi drivers and the association with psychosocial characteristics of their work. This was a cross-sectional epidemiological study with a sample of 400 motorcycle taxi drivers in Jequié, Bahia State, Brazil. The study used a form containing demographic and socioeconomic data, WHO Quality of Life-Bref Questionnaire (WHOQOL-Bref), and the Job Content Questionnaire (JCQ). Motorcycle taxi drivers with greater decision-making control over their work showed better self-rated quality of life in the psychological domain; those with high psychological demands presented better self-rated quality of life in the social relations and environmental domains; those with high strain and active work showed better self-rated quality of life in the social and environmental domains. The psychosocial work environment and especially decision-making autonomy were thus important determinants of self-rated quality of life in this group of motorcycle taxi drivers.

Linking the molecular evolution of avian beta (β) keratins to the evolution of feathers.

Science.gov (United States)

Greenwold, Matthew J; Sawyer, Roger H

2011-12-15

Feathers of today's birds are constructed of beta (β)-keratins, structural proteins of the epidermis that are found solely in reptiles and birds. Discoveries of "feathered dinosaurs" continue to stimulate interest in the evolutionary origin of feathers, but few studies have attempted to link the molecular evolution of their major structural proteins (β-keratins) to the appearance of feathers in the fossil record. Using molecular dating methods, we show that before the appearance of Anchiornis (∼155 Million years ago (Ma)) the basal β-keratins of birds began diverging from their archosaurian ancestor ∼216 Ma. However, the subfamily of feather β-keratins, as found in living birds, did not begin diverging until ∼143 Ma. Thus, the pennaceous feathers on Anchiornis, while being constructed of avian β-keratins, most likely did not contain the feather β-keratins found in the feathers of modern birds. Our results demonstrate that the evolutionary origin of feathers does not coincide with the molecular evolution of the feather β-keratins found in modern birds. More likely, during the Late Jurassic, the epidermal structures that appeared on organisms in the lineage leading to birds, including early forms of feathers, were constructed of avian β-keratins other than those found in the feathers of modern birds. Recent biophysical studies of the β-keratins in feathers support the view that the appearance of the subfamily of feather β-keratins altered the biophysical nature of the feather establishing its role in powered flight. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

Melanin-based color of plumage: role of condition and of feathers' microstructure

Science.gov (United States)

D'Alba, Liliana; Van Hemert, Caroline R.; Spencer, Karen A.; Heidinger, Britt J.; Gill, Lisa; Evans, Neil P.; Monaghan, Pat; Handel, Colleen M.; Shawkey, Matthew D.

2014-01-01

Whether melanin-based colors honestly signal a bird's condition during the growth of feathers is controversial, and it is unclear if or how the physiological processes underlying melanogenesis or color-imparting structural feather microstructure may be adversely affected by condition. Here we report results from two experiments designed to measure the effect of condition on expression of eumelanic and pheomelanic coloration in black-capped chickadees (Poecile atricapillus) and zebra finches (Taeniopygia guttata), respectively. In chickadees, we compared feathers of birds affected and unaffected by avian keratin disorder, while in zebra finches we compared feathers of controls with feathers of those subjected to an unpredictable food supply during development. In both cases we found that control birds had brighter feathers (higher total reflectance) and more barbules, but similar densities of melanosomes. In addition, the microstructure of the feathers explained variation in color more strongly than did melanosome density. Together, these results suggest that melanin-based coloration may in part be condition-dependent, but that this may be driven by changes in keratin and feather development, rather than melanogenesis itself. Researchers should be cautious when assigning variation in melanin-based color to melanin alone and microstructure of the feather should be taken into account.

A lightweight, biological structure with tailored stiffness: The feather vane.

Science.gov (United States)

Sullivan, Tarah N; Pissarenko, Andreï; Herrera, Steven A; Kisailus, David; Lubarda, Vlado A; Meyers, Marc A

2016-09-01

The flying feathers of birds are keratinous appendages designed for maximum performance with a minimum weight penalty. Thus, their design contains ingenious combinations of components that optimize lift, stiffness, aerodynamics, and damage resistance. This design involves two main parts: a central shaft that prescribes stiffness and lateral vanes which allows for the capture of air. Within the feather vane, barbs branch from the shaft and barbules branch from barbs, forming a flat surface which ensures lift. Microhooks at the end of barbules hold barbs tightly together, providing the close-knit, unified structure of the feather vane and enabling a repair of the structure through the reattachment of un-hooked junctions. Both the shaft and barbs are lightweight biological structures constructed of keratin using the common motif of a solid shell and cellular interior. The cellular core increases the resistance to buckling with little added weight. Here we analyze the detailed structure of the feather barb and, for the first time, explain its flexural stiffness in terms of the mechanics of asymmetric foam-filled beams subjected to bending. The results are correlated and validated with finite element modeling. We compare the flexure of single barbs as well as arrays of barbs and find that the interlocking adherence of barbs to one another enables a more robust structure due to minimized barb rotation during deflection. Thus, the flexure behavior of the feather vane can be tailored by the adhesive hooking between barbs, creating a system that mitigates damage. A simplified three-dimensional physical model for this interlocking mechanism is constructed by additive manufacturing. The exceptional architecture of the feather vane will motivate the design of bioinspired structures with tailored and unique properties ranging from adhesives to aerospace materials. Despite its importance to bird flight, literature characterizing the feather vane is extremely limited. The feather

Institutional statism: an overview of the formulation of the taxi recapitalisation policy

Directory of Open Access Journals (Sweden)

D. van Schalkwyk

2008-07-01

Full Text Available This article provides an overview of the government’s formulation of the taxi recapitalisation policy which is aimed at regulating the minibus taxi industry. Coupled with a brief social and politico-historical context of the policy, the aim is to highlight the government’s statist conduct in the formulation of the recapitalisation policy. The minibus taxi industry started to fulfil a prominent role in the 1970s as a result of a loophole in the legislation of the former apartheid government. It is currently the most accessible mode of public transport and conveys 65 per cent of the country’s commuters daily. Consequently, the Industry is an imperative force to be considered by the government in its formulation of transport policies. However, the industry is characterised by numerous problems, including a high rate of minibus taxis involved in accidents, unroadworthy vehicles and violence. It is in this context that the government formulated both the original and revised versions of the recapitalisation policy. However, the formulation of the policy has been problematic. The government followed a statist approach during the formulation process when it directed the course of the process according to its interests and without adequate consultation with relevant role players.

Research on Strategy Control of Taxi Carpooling Detour Route under Uncertain Environment

Directory of Open Access Journals (Sweden)

Wei Zhang

2016-01-01

Full Text Available For the problem of route choice in taxi carpooling detour, considering the uncertainty of traffic and the characteristic of passengers’ noncomplete rationality, an evolutionary game model of taxi carpooling detour route is built, in which prospect theory is introduced and revenue of strategy is replaced by prospect value. The model reflects more really decision-making psychology of passengers. Then the stable strategies of the model are studied, and the influences of detour distance and traffic congestion on detour carpooling success are analyzed, respectively. The results show that when at least one route of which prospect values for two passenger sides are both positive exists, carpooling route can reach an agreement. The route is stable strategy of evolutionary game, and the passengers requiring short travel time tend to select the nondetour route. With the increase of detour distance and traffic congestion rate, the possibility of reaching an agreement decreases gradually; that is, possibility of carpooling failure increases. So taxi carpooling detour is possible under the certain condition, but some measures must be carried out such as constraints of detour distance and mitigation of traffic congestion to improve carpooling success probability. These conclusions have a certain guiding significance to the formulation of taxi carpooling policy.

Terminal area automatic navigation, guidance, and control 1: Automatic rollout, turnoff, and taxis

Science.gov (United States)

Pines, S.

1981-01-01

A study developed for the TCV B-737, designed to apply existing navigation aids plus magnetic leader cable signals and develop breaking and reverse thrust guidance laws to provide for rapid automated rollout, turnoff, and taxi to reduce runway occupation time for a wide variety of landing conditions for conventional commercial-type aircraft, is described. Closed loop guidance laws for braking and reverse thrust are derived for rollout, turnoff, and taxi, as functions of the landing speed, the desired taxi speed and the distance to go. Brake limitations for wet runway conditions and reverse thrust limitations are taken into account to provide decision rules to avoid tire skid and to choose an alternate turnoff point, farther down the runway, to accommodate extreme landing conditions.

Het CBb en 'Der digitale Taxi-Krieg'

NARCIS (Netherlands)

Westerveld, M.

2015-01-01

UberPOP, the taxi service company that claims to be based on the concept of shared economy, offering a positive effect on mobility, environment and usage of energy, in reality confronts us with the question whether we are able to protect 'on demand' workers against exploitation and underpayment. The

Chemical regulation of body feather microbiota in a wild bird.

Science.gov (United States)

Jacob, Staffan; Sallé, Louis; Zinger, Lucie; Chaine, Alexis S; Ducamp, Christine; Boutault, Léa; Russell, Andrew F; Heeb, Philipp

2018-04-01

The microbiota has a broad range of impacts on host physiology and behaviour, pointing out the need to improve our comprehension of the drivers of host-microbiota composition. Of particular interest is whether the microbiota is acquired passively, or whether and to what extent hosts themselves shape the acquisition and maintenance of their microbiota. In birds, the uropygial gland produces oily secretions used to coat feathers that have been suggested to act as an antimicrobial defence mechanism regulating body feather microbiota. However, our comprehension of this process is still limited. In this study, we for the first time coupled high-throughput sequencing of the microbiota of both body feathers and the direct environment (i.e., the nest) in great tits with chemical analyses of the composition of uropygial gland secretions to examine whether host chemicals have either specific effects on some bacteria or nonspecific broad-spectrum effects on the body feather microbiota. Using a network approach investigating the patterns of co-occurrence or co-exclusions between chemicals and bacteria within the body feather microbiota, we found no evidence for specific promicrobial or antimicrobial effects of uropygial gland chemicals. However, we found that one group of chemicals was negatively correlated to bacterial richness on body feathers, and a higher production of these chemicals was associated with a poorer body feather bacterial richness compared to the nest microbiota. Our study provides evidence that chemicals produced by the host might function as a nonspecific broad-spectrum antimicrobial defence mechanism limiting colonization and/or maintenance of bacteria on body feathers, providing new insight about the drivers of the host's microbiota composition in wild organisms. © 2018 John Wiley & Sons Ltd.

The relation between working conditions, aberrant driving behaviour and crash propensity among taxi drivers in China.

Science.gov (United States)

Wang, Yonggang; Li, Linchao; Prato, Carlo G

2018-04-03

Although the taxi industry is playing an important role in Chinese everyday life, little attention has been posed towards occupational health issues concerning the taxi drivers' working conditions, driving behaviour and road safety. A cross-sectional survey was administered to 1021 taxi drivers from 21 companies in four Chinese cities and collected information about (i) sociodemographic characteristics, (ii) working conditions, (iii) frequency of daily aberrant driving behaviour, and (iv) involvement in property-damage-only (PDO) and personal injury (PI) crashes over the past two years. A hybrid bivariate model of crash involvement was specified: (i) the hybrid part concerned a latent variable model capturing unobserved traits of the taxi drivers; (ii) the bivariate part modelled jointly both types of crashes while capturing unobserved correlation between error terms. The survey answers paint a gloomy picture in terms of workload, as taxi drivers reported averages of 9.4 working hours per day and 6.7 working days per week that amount on average to about 63.0 working hours per week. Moreover, the estimates of the hybrid bivariate model reveal that increasing levels of fatigue, reckless behaviour and aggressive behaviour are positively related to a higher propensity of crash involvement. Lastly, the heavy workload is also positively correlated with the higher propensity of crashing, not only directly as a predictor of crash involvement, but also indirectly as a covariate of fatigue and aberrant driving behaviour. The findings from this study provide insights into potential strategies for preventive education and taxi industry management to improve the working conditions and hence reduce fatigue and road risk for the taxi drivers. Copyright © 2018 Elsevier Ltd. All rights reserved.

Lead, mercury, cadmium, chromium, and arsenic levels in eggs, feathers, and tissues of Canada geese of the New Jersey Meadowlands

International Nuclear Information System (INIS)

Tsipoura, Nellie; Burger, Joanna; Newhouse, Michael; Jeitner, Christian; Gochfeld, Michael; Mizrahi, David

2011-01-01

The New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury. These metals were analyzed in eggs, feathers, muscle, and liver of Canada geese (Branta canadensis) breeding in four wetland sites. We sampled geese collected during control culling (n=26) and collected eggs from goose nests (n=34). Levels of arsenic were below the minimum quantification level (MQL) in most samples, and cadmium and mercury were low in all tissues sampled. Chromium levels were high in feather samples. Mercury levels in eggs of Canada geese, an almost exclusively herbivorous species, were lower (mean ±SE 4.29±0.30 μg/g wet weight) than in eggs of omnivorous mallards (Anas platyrhynchos), and insectivorous red-winged blackbirds (Agelaius phoeniceus) and marsh wrens (Cistothorus palustris) from the Meadowlands, consistent with trophic level differences. However, lead levels were higher in the goose eggs (161±36.7 ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910±386 ng/g) than those seen in Meadowlands passerines. By contrast, muscle and liver lead levels were within the range reported in waterfowl elsewhere, possibly a reflection of metal sequestration in eggs and feathers. Elevated lead levels may be the result of sediment ingestion or ingestion of lead shot and sinkers. Finally, lead levels in goose liver (249±44.7 ng/g) and eggs (161±36.7 ng/g) may pose a risk if consumed

Economic Analysis on Value Chain of Taxi Fleet with Battery-Swapping Mode Using Multiobjective Genetic Algorithm

OpenAIRE

Ning, Guobao; Zhen, Zijian; Wang, Peng; Li, Yang; Yin, Huaixian

2012-01-01

This paper presents an economic analysis model on value chain of taxi fleet with battery-swapping mode in a pilot city. In the model, economic benefits of charging-swapping station group, taxi company, and taxi driver in the region have been taken into consideration. Thus, the model is a multiobjective function and multiobjective genetic algorithm is used to solve this problem. According to the real data collected from the pilot city, the multiobjective genetic algorithm is tested as an effec...

Interpopulation Variation in Contour Feather Structure Is Environmentally Determined in Great Tits

Science.gov (United States)

Broggi, Juli; Gamero, Anna; Hohtola, Esa; Orell, Markku; Nilsson, Jan-Åke

2011-01-01

Background The plumage of birds is important for flying, insulation and social communication. Contour feathers cover most of the avian body and among other functions they provide a critical insulation layer against heat loss. Feather structure and composition are known to vary among individuals, which in turn determines variation in the insulation properties of the feather. However, the extent and the proximate mechanisms underlying this variation remain unexplored. Methodology/Principal Findings We analyzed contour feather structure from two different great tit populations adapted to different winter regimes, one northern population in Oulu (Finland) and one southern population in Lund (Sweden). Great tits from the two populations differed significantly in feather structure. Birds from the northern population had a denser plumage but consisting of shorter feathers with a smaller proportion containing plumulaceous barbs, compared with conspecifics from the southern population. However, differences disappeared when birds originating from the two populations were raised and moulted in identical conditions in a common-garden experiment located in Oulu, under ad libitum nutritional conditions. All birds raised in the aviaries, including adult foster parents moulting in the same captive conditions, developed a similar feather structure. These feathers were different from that of wild birds in Oulu but similar to wild birds in Lund, the latter moulting in more benign conditions than those of Oulu. Conclusions/Significance Wild populations exposed to different conditions develop contour feather differences either due to plastic responses or constraints. Environmental conditions, such as nutrient availability during feather growth play a crucial role in determining such differences in plumage structure among populations. PMID:21949798

Interpopulation variation in contour feather structure is environmentally determined in great tits.

Directory of Open Access Journals (Sweden)

Juli Broggi

Full Text Available The plumage of birds is important for flying, insulation and social communication. Contour feathers cover most of the avian body and among other functions they provide a critical insulation layer against heat loss. Feather structure and composition are known to vary among individuals, which in turn determines variation in the insulation properties of the feather. However, the extent and the proximate mechanisms underlying this variation remain unexplored.We analyzed contour feather structure from two different great tit populations adapted to different winter regimes, one northern population in Oulu (Finland and one southern population in Lund (Sweden. Great tits from the two populations differed significantly in feather structure. Birds from the northern population had a denser plumage but consisting of shorter feathers with a smaller proportion containing plumulaceous barbs, compared with conspecifics from the southern population. However, differences disappeared when birds originating from the two populations were raised and moulted in identical conditions in a common-garden experiment located in Oulu, under ad libitum nutritional conditions. All birds raised in the aviaries, including adult foster parents moulting in the same captive conditions, developed a similar feather structure. These feathers were different from that of wild birds in Oulu but similar to wild birds in Lund, the latter moulting in more benign conditions than those of Oulu.Wild populations exposed to different conditions develop contour feather differences either due to plastic responses or constraints. Environmental conditions, such as nutrient availability during feather growth play a crucial role in determining such differences in plumage structure among populations.

The development and causation of feather pecking in the domestic fowl

NARCIS (Netherlands)

Blokhuis, H.J.

1989-01-01

Feather pecking in poultry consists of pecking directed at the feathers of other birds, sometimes pulling out and eating these feathers. It may result in severe damage of the integument of the birds, including wounds of the skin. Finally wounded birds may be pecked to death (cannibalism).

Purification and characterization of a keratinase from the feather ...

African Journals Online (AJOL)

Yomi

2012-01-31

Jan 31, 2012 ... ... a keratinase from the feather-degrading cultures of Aspergillus flavipes ..... fumigatus (Santos et al., 1996) and A. oryzae (Bressollier et al., 1999). ..... composition and nitrogen characteristics of feather meal. Anim. Feed. Sci.

Trace element contamination in feather and tissue samples from Anna’s hummingbirds

Science.gov (United States)

Mikoni, Nicole A.; Poppenga, Robert H.; Ackerman, Joshua T.; Foley, Janet E.; Hazlehurst, Jenny; Purdin, Güthrum; Aston, Linda; Hargrave, Sabine; Jelks, Karen; Tell, Lisa A.

2017-01-01

Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The

Large-scale deployment of electric taxis in Beijing: A real-world analysis

International Nuclear Information System (INIS)

Zou, Yuan; Wei, Shouyang; Sun, Fengchun; Hu, Xiaosong; Shiao, Yaojung

2016-01-01

The national and municipal government of China enacted a series of regulations and policies to stimulate/promote the development of new energy vehicles, in order to mitigate the increasingly serious carbon emissions, environmental pollution, and energy shortage. As a large metropolitan and populated city subject to the notorious air pollution, Beijing has been making a remarkable progress in the large-scale demonstration of new energy vehicles in recent years, which could result in a significant impact on both transport and electricity sectors. As a result, there is an urgent necessity to study the characteristics of the large-scale new energy vehicles adoption for a deep understanding of operational status (e.g., energy consumption and battery charging patterns) and benefits, as well as charging facilities. Based on the operational data collected from realistic electric-taxi demonstration in Beijing, the driver behavior and charging characteristics are examined in this paper. The energy consumption and efficiency of two representative electric-taxi platforms are compared, and the influence of the driving schedules is discussed. The results show that the average driving distance per day of these electric taxes is 117.98 km, and 92% of drivers recharge their cars twice per day. Further study shows that the drivers make two trips per day, and the two peaks in the distribution of departure and arrival times coincide with the rush hour in the morning and evening. The taxi recharge duration is largely influenced by the charging power. Generally, the associated battery SOC (state of charge) swing is between 40% and 100%. By evaluating the energy consumption of 282 trips recorded in 2013 and 2014, we find that the two platforms have similar energy efficiency. The micro-trips method is utilized to probe the correlation of energy consumption and average speed. - Highlights: • Electric taxis' driver behavior and charging characteristics is analyzed based on operation data

Early and late feathering in Turkey and chicken

NARCIS (Netherlands)

Derks, Martijn F.L.; Herrero-Medrano, Juan M.; Crooijmans, Richard P.M.A.; Vereijken, Addie; Long, Julie A.; Megens, Hendrik Jan; Groenen, Martien A.M.

2018-01-01

Background: Sex-linked slow (SF) and fast (FF) feathering rates at hatch have been widely used in poultry breeding for autosexing at hatch. In chicken, the sex-linked K (SF) and k+ (FF) alleles are responsible for the feathering rate phenotype. Allele K is dominant and a partial duplication of the

Identification of shed or plucked origin of Indian peafowl (Pavo cristatus) tail feathers: preliminary findings.

Science.gov (United States)

Sahajpal, Vivek; Goyal, S P

2008-06-01

Indian Peafowl (Pavo cristatus) tail covert feathers were studied to investigate the difference between shed and plucked feathers in the context of wildlife offence cases involving the killing of the Indian national bird for the purpose of plucking feathers. Plucked feathers were distinguished from shed feathers by examining their roots under low magnification of a stereoscopic microscope. A chemical test to show the presence of blood on the roots of plucked feathers was used to corroborate the plucked origin of feathers.

Inconvenient and Unnecessary? Regulations in the U.S. Taxi Industry

Directory of Open Access Journals (Sweden)

Johnson Colton

2017-12-01

Full Text Available A Certificate of Public Convenience and Necessity (CPCN is a common requirement for a new business owner in services such as utilities, communications, healthcare, and transportation. However, studies have called into question the effectiveness and purpose of these laws when applied in certain industries. This study chronicles the development of and justifications provided for the enactment of CPCN laws. It then empirically tests the effectiveness of these laws in the taxi industry. This paper finds no evidence that the CPCN laws in the taxi industry are meeting their objectives. Some evidence suggests that CPCN laws achieve the opposite of their intention.

Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

Science.gov (United States)

Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

2013-12-01

Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.

Association of Some Environmental Factors with Breath Carbon Monoxide Levels of Some Taxi Drivers in Ankara

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Oguz Baran

2010-12-01

Full Text Available AIM: Taxi drivers are among the occupational groups with the highest smoking prevalence and exposure to carbon monoxide (CO. This study aimed to measure breath CO levels of some taxi drivers working in Ankara and to find out some associated factors (if any. METHOD: The descriptive study was carried out with 173 taxi drivers from 14 different taxi stations in the center of Ankara. Data was collected by face to face interviews with a standart questionnaire, while breath CO was measured by a Pi-CO Smokerlyser. Descriptive statistics were used to summarize data, whereas chi-square, independant samples t-test and One-Way ANOVA were used to compare groups by SPSS 15.0 statistical package programme. RESULTS: In the study, all of the taxi drivers (n=173 were male with a mean age of 39.2±9.6 years. Of the drivers, 58.4% were current smokers, whereas 75.1% were exposed to enviromental tobacco smoke. The frequency of indoor smoking in the taxi stations, taxis and drivers’ homes were 48.0%, 45.1%, and 59.0%, respectively. The mean breath CO level of the drivers was 16.9±12.8 ppm. CO level was positively associated with the current smoking status, total years of smoking, number of cigarettes smoked per day and passive exposure to tobacco smoke, whereas the association was negative with the elapsed time from the last cigarette smoked (p0.05. CONCLUSION: Results of the study provide evidence in support of the previous literature that smoking is one of the most important sources of carbonmonoxide. Interventions such as awareness raising trainings, referral of smokers willing to quit smoking to smoking cessation centers and screening programmes for smoking related diseases are needed to be implemented in collaboration with the relevant drivers’ associations. [TAF Prev Med Bull 2010; 9(6.000: 591-596

[Dynamics of infection of Fringilla coelebs chaffinch nestlings with feather mites (Acari: Analgoidea)].

Science.gov (United States)

Mironov, S V; Malyshev, L L

2002-01-01

surface of the big upper coverts of primary flight feathers. This species appears on the chaffinch nestlings in a significant number on 7th day. The mites occupy the basal parts of primary flight feathers represented in that moment by the rods only. They sit on practically open and smooth surface of this microhabitat, which is uncommon for them, because the vanes of the big upper coverts are not yet open and also represented by thin rods. During the period of the last 5 days (from 7 to 11th day) the mean number of mites per one nestling increases from 2.3 +/- 0.5 to 17.1 +/- 1.8 mites. Just before the day, when the nestling leave the nest, the tritonymphs absolutely predominate (82.4%) in the micropopulation of P. striatus. Analges passerinus (Analgidae) is specialised to live in the friable layer formed by numerous not-engaged thread barbles of the down feathers and basal parts of the body covert feathers. Mites have special hooks on legs used for hard attaching to the barbles and for fast moving in the friable layer of feathers. On the chaffinch nestlings, these mites appear usually on 8th day, when the rod-like body covert feathers begin to open on apices and form short brushes; however some individuals occur on the skin of nestlings even on 6th day. The mean number of mites per nestling on the 11th day reaches 16.5 +/- 1.4 individuals. The micropopulation of A. passerinus is represented on the nestlings mainly by the females (45.5%), tritonymphs (23.6%) and males (11.5%). Monojobertia microphylla (Proctophyllodidae) is a typical dweller of feathers with large vanes. Mites of this species commonly occupy the ventral surface of primary and secondary flight feathers and also respective big upper covert feathers of wings. M. microphylla appears on the nestlings in a significant number (7.1 +/- 1.2 mites) on 9th day, only when the primary flight feathers already have short vanes about 10 mm in length. In next three days the number of mites increases very fast and reaches

Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

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Seyyed Mohammad Javad Golhosseini

2015-06-01

Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOC are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC.

Minibus taxi drivers’ sexual beliefs and practices associated with HIV infection and AIDS in KwaZulu- Natal, South Africa

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Busisiwe Ncama

2013-01-01

Full Text Available Risky sexual behaviours in South Africa are a major contributing factor to the spread of HIV infection and AIDS. HIV infection amongst minibus taxi drivers is a concern, because these people belong to an occupational group that exhibits risky behaviours due to the demands of their work. Given the high vulnerability of minibus taxi drivers, exploring the sexual beliefs and health-related sexual practices of this group will assist in planning targeted interventions.The objectives of this study were to assess the level of knowledge, beliefs and practices regarding HIV infection and AIDS amongst minibus taxi drivers. An exploratory descriptive study was conducted using a pre-tested questionnaire to explore and describe sexual beliefs and practices associated with HIV infection and AIDS in a convenience sample of 175 minibus taxi drivers. Permission to undertake the study was obtained from the KwaZulu-Natal Taxi Alliance and individuals who participated in the study. Data analysis were analysed using the Statistical Package for Social Sciences 13.0. The study revealed that minibus taxi drivers are one of the high- risk groups in the spread of HIV infection and AIDS; they lack necessary education and need attention in relation to control and prevention of the spread of HIV and AIDS. Multiple sexual partners are relatively common amongst the minibus taxi drivers. Violence against women and even forceful sexual intercourse in the belief that women should tolerate it to keep the family together was reported. There is a need for intervention programmes with a focus on minibus taxi drivers and similar high-risk groups. Prevention activities should incorporate the distribution of condoms amongst this group and HIV prevention educational programmes, as well as creating mechanisms for accessing circumcision by the minibus taxi drivers.

Morphology of primary feathers in two falcon species

Science.gov (United States)

Honisch, B.; Bleckmann, H.; Schmitz, H.; Schmitz, A.

2012-04-01

Primary feathers allow birds to fly; however, morphology and material properties of theses feathers vary in different bird species. We therefore analysed both morphology and material properties of primary feathers in two raptor species, the peregrine falcon (Falco peregrinus) which is the fastest vertical flyer known, and the kestrel (Falco tinnunculus), using scanning electron microscopy (SEM) and nanoindentation. The program AutoCAD was used for the computation of the moments of inertia. The reduced E-modulus of the cortex of the rachis of the first, fifth, and tenth primary were measured at proximal (10% of total rachis length), central (50%) and distal (75%) cross-sections. In all cross sections the kestrel showed higher E-moduli than the peregrine falcon (values varied between 6.7 and 9.1 GPa). In the primaries, values increased from proximal to central but decreased distally. Looking at the hardness, the kestrel had higher values than the peregrine falcon yet again. The main differences occurred in the first primary. Values ranged between 0.17 and 0.4 GPa. SEM studies revealed that the tenth primary was more stable in the peregrine falcon, featuring more hamuli than the kestrel at all analysed positions and longer hamuli at the distal positions. The higher moments of inertia found in the peregrine falcon caused a much higher bending stiffness in this species. Values were 4.4 to 9.1 times larger in the peregrine falcon than in the kestrel. Because the given structures are responsible for the stability of the feather face it seems that the feathers of F. peregrinus are more robust than those of F. tinnunculus. Even when considering the higher body mass of the peregrine falcon compared to the kestrel (3.4 times), the determined stability of the feather compensates for this problem.

Improved keratinase production for feather degradation by Bacillus ...

African Journals Online (AJOL)

Optimal medium was used to improve the production of keratinase by Bacillus licheniformis ZJUEL31410, which has a promising application in the transformation of feather into soluble protein. The results of single factor design revealed that the concentration of feather at 20 g/l and the initial pH at value 8 was the best for ...

Theoretical morphology and development of flight feather vane asymmetry with experimental tests in parrots.

Science.gov (United States)

Feo, Teresa J; Prum, Richard O

2014-06-01

Asymmetry in flight feather vane width is a major functional innovation associated with the evolution of flight in the ancestors of birds. However, the developmental and morphological basis of feather shape is not simple, and the developmental processes involved in vane width asymmetry are poorly understood. We present a theoretical model of feather morphology and development that describes the possible ways to modify feather development and produce vane asymmetry. Our model finds that the theoretical morphospace of feather shape is redundant, and that many different combinations of parameters could be responsible for vane asymmetry in a given feather. Next, we empirically measured morphological and developmental model parameters in asymmetric and symmetric feathers from two species of parrots to identify which combinations of parameters create vane asymmetry in real feathers. We found that both longer barbs, and larger barb angles in the relatively wider trailing vane drove asymmetry in tail feathers. Developmentally, longer barbs were the result of an offset of the radial position of the new barb locus, whereas larger barb angles were produced by differential expansion of barbs as the feather unfurls from the tubular feather germ. In contrast, the helical angle of barb ridge development did not contribute to vane asymmetry and could be indicative of a constraint. This research provides the first comprehensive description of both the morphological and developmental modifications responsible for vane asymmetry within real feathers, and identifies key steps that must have occurred during the evolution of vane asymmetry. © 2014 Wiley Periodicals, Inc.

Talent in the taxi: a model system for exploring expertise.

Science.gov (United States)

Woollett, Katherine; Spiers, Hugo J; Maguire, Eleanor A

2009-05-27

While there is widespread interest in and admiration of individuals with exceptional talents, surprisingly little is known about the cognitive and neural mechanisms underpinning talent, and indeed how talent relates to expertise. Because many talents are first identified and nurtured in childhood, it can be difficult to determine whether talent is innate, can be acquired through extensive practice or can only be acquired in the presence of the developing brain. We sought to address some of these issues by studying healthy adults who acquired expertise in adulthood. We focused on the domain of memory and used licensed London taxi drivers as a model system. Taxi drivers have to learn the layout of 25,000 streets in London and the locations of thousands of places of interest, and pass stringent examinations in order to obtain an operating licence. Using neuropsychological assessment and structural and functional magnetic resonance imaging, we addressed a range of key questions: in the context of a fully developed brain and an average IQ, can people acquire expertise to an exceptional level; what are the neural signatures, both structural and functional, associated with the use of expertise; does expertise change the brain compared with unskilled control participants; does it confer any cognitive advantages, and similarly, does it come at a cost to other functions? By studying retired taxi drivers, we also consider what happens to their brains and behaviour when experts stop using their skill. Finally, we discuss how the expertise of taxi drivers might relate to the issue of talent and innate abilities. We suggest that exploring talent and expertise in this manner could have implications for education, rehabilitation of patients with cognitive impairments, understanding individual differences and possibly conditions such as autism where exceptional abilities can be a feature.

Minibus taxi drivers’ sexual beliefs and practices associated with HIV infection and AIDS in KwaZulu- Natal, South Africa

Directory of Open Access Journals (Sweden)

Busisiwe Ncama

2013-01-01

The objectives of this study were to assess the level of knowledge, beliefs and practices regarding HIV infection and AIDS amongst minibus taxi drivers. An exploratory descriptive study was conducted using a pre-tested questionnaire to explore and describe sexual beliefs and practices associated with HIV infection and AIDS in a convenience sample of 175 minibus taxi drivers. Permission to undertake the study was obtained from the KwaZulu-Natal Taxi Alliance and individuals who participated in the study. Data analysis were analysed using the Statistical Package for Social Sciences 13.0. The study revealed that minibus taxi drivers are one of the high- risk groups in the spread of HIV infection and AIDS; they lack necessary education and need attention in relation to control and prevention of the spread of HIV and AIDS. Multiple sexual partners are relatively common amongst the minibus taxi drivers. Violence against women and even forceful sexual intercourse in the belief that women should tolerate it to keep the family together was reported. There is a need for intervention programmes with a focus on minibus taxi drivers and similar high-risk groups. Prevention activities should incorporate the distribution of condoms amongst this group and HIV prevention educational programmes, as well as creating mechanisms for accessing circumcision by the minibus taxi drivers.

Les aspects matériels de la taxis byzantine The material aspects of the Byzantine taxis

Directory of Open Access Journals (Sweden)

Marie‑France Auzépy

2008-06-01

Full Text Available La taxis grecque – correspondant exact de l’ordo latin – est un aspect essentiel de la civilisation byzantine : elle organise cette société de manière à ce que celle-ci soit un reflet aussi exact que possible de la société céleste, décrite en particulier par Denys l’Aréopagite. La taxis est donc à la fois précise et contraignante et nous a été transmise dans des livres décrivant le protocole : le De Cerimoniis au Xe siècle, le Traité du pseudo-Kodinos au XIVe siècle. Au cours de cérémonies où tous les aspects matériels – l’habit, la couronne, le trône, les acclamations à la gloire de l’empereur, l’orgue qui les accompagne, les gestes accomplis par l’empereur comme par ceux qui l’entourent – ont un sens, l’Empire byzantin affirme ainsi son équilibre et sa qualité de peuple élu. Jusqu’en 1204, les autres nations ont jalousé la qualité que s’était octroyée l’Empire romain d’Orient : celle d’image de la cour céleste, qui est figurée dans le cérémonial. Cette jalousie a pris d’autres formes après 1453, et l’on s’intéressera aux souverains européens qui, tel Louis XIV, ont voulu faire figure d’héritiers de l’empire défunt et relever ses cérémonies.The Greek taxis(order– the exact equivalent of the Latin ordo – is an essential aspect of Byzantine civilization: it organized society in such a way that it would reflect the celestial society as closely as possible, as has been described by Dionysius the Areopagite. The taxis is therefore both precise and restrictive and has been passed down to us through writings describing the protocol: the De Cerimoniis in the tenth century and the treatise of Pseudo-Kodinos in the fourteenth century. Through ceremonies in which all the material aspects have a meaning – the dress, the crown, the throne, the proclaiming of the glory of the emperor, the accompanying organ, the gestures of the emperor and of those around

Vibrational spectroscopic analyses of unique yellow feather pigments (spheniscins) in penguins.

Science.gov (United States)

Thomas, Daniel B; McGoverin, Cushla M; McGraw, Kevin J; James, Helen F; Madden, Odile

2013-06-06

Many animals extract, synthesize and refine chemicals for colour display, where a range of compounds and structures can produce a diverse colour palette. Feather colours, for example, span the visible spectrum and mostly result from pigments in five chemical classes (carotenoids, melanins, porphyrins, psittacofulvins and metal oxides). However, the pigment that generates the yellow colour of penguin feathers appears to represent a sixth, poorly characterized class of feather pigments. This pigment class, here termed 'spheniscin', is displayed by half of the living penguin genera; the larger and richer colour displays of the pigment are highly attractive. Using Raman and mid-infrared spectroscopies, we analysed yellow feathers from two penguin species (king penguin, Aptenodytes patagonicus; macaroni penguin, Eudyptes chrysolophus) to further characterize spheniscin pigments. The Raman spectrum of spheniscin is distinct from spectra of other feather pigments and exhibits 17 distinctive spectral bands between 300 and 1700 cm(-1). Spectral bands from the yellow pigment are assigned to aromatically bound carbon atoms, and to skeletal modes in an aromatic, heterocyclic ring. It has been suggested that the penguin pigment is a pterin compound; Raman spectra from yellow penguin feathers are broadly consistent with previously reported pterin spectra, although we have not matched it to any known compound. Raman spectroscopy can provide a rapid and non-destructive method for surveying the distribution of different classes of feather pigments in the avian family tree, and for correlating the chemistry of spheniscin with compounds analysed elsewhere. We suggest that the sixth class of feather pigments may have evolved in a stem-lineage penguin and endowed modern penguins with a costly plumage trait that appears to be chemically unique among birds.

Mechanical and Morphology Properties of Feather Fiber Composite for Dental Post Application

International Nuclear Information System (INIS)

Siti Maizatul Farhain Salehuddin; Mohammed Rafiq Abdul Kadir; Eshamsul Sulaiman; Noor Hayaty Abu Kasim

2014-01-01

Feather/plastic composite material was fabricated from polymethyl methacrylate (PMMA), feather fiber (FF) and montmorillonite (MMT) using brabender internal mixer. PMMA based composites were produced with 1, 3, 5, 7 and 10 phr composite of mass feather fiber with and without 4 % of montmorillonite (MMT). Alkali treatment was used to improve the interfacial adhesion among the feather fiber (FF) and the PMMA. Flexural properties of FF/ PMMA and FF/ PMMA/ MMT composites were investigated. Composites were analyzed by Scanning Electron (SEM) and Fourier Transform Infra Red (FTIR) spectroscopy techniques. The result showed that, the addition of FF significantly increased the flexural strength of the composites. The hydrophobic nature of feather fiber displayed an excellent compatibility among fibers and PMMA matrix. (author)

Estimation of occupational and nonoccupational nitrogen dioxide exposure for Korean taxi drivers using a microenvironmental model

International Nuclear Information System (INIS)

Son, Busoon; Yang, Wonho; Breysse, Patrick; Chung, Taewoong; Lee, Youngshin

2004-01-01

Occupational and nonoccupational personal nitrogen dioxide (NO 2 ) exposures were measured using passive samplers for 31 taxi drivers in Asan and Chunan, Korea. Exposures were also estimated using a microenvironmental time-weighted average model based on indoor, outdoor and inside the taxi area measurements. Mean NO 2 indoor and outdoor concentrations inside and outside the taxi drivers' houses were 24.7±10.7 and 23.3±8.3 ppb, respectively, with a mean indoor to outdoor NO 2 ratio of 1.1. Mean personal NO 2 exposure of taxi drivers was 30.3±9.7 ppb. Personal NO 2 exposures for drivers were more strongly correlated with interior vehicle NO 2 levels (r=0.89) rather than indoor residential NO 2 levels (r=0.74) or outdoor NO 2 levels (r=0.71). The main source of NO 2 exposure for taxi drivers was considered to be occupational driving. Interestingly, the NO 2 exposures for drivers' using LPG-fueled vehicles (26.3±1.3 ppb) were significantly lower than those (38.1±1.3 ppb) using diesel-fueled vehicle (P 2 exposure with indoor and outdoor NO 2 levels of the residence, and interior vehicle NO 2 levels (P 2 levels because they drive diesel-using vehicles outdoors in Korea

Ontogeny of lift and drag production in ground birds.

Science.gov (United States)

Heers, Ashley M; Tobalske, Bret W; Dial, Kenneth P

2011-03-01

The juvenile period is often a crucial interval for selective pressure on locomotor ability. Although flight is central to avian biology, little is known about factors that limit flight performance during development. To improve understanding of flight ontogeny, we used a propeller (revolving wing) model to test how wing shape and feather structure influence aerodynamic performance during development in the precocial chukar partridge (Alectoris chukar, 4 to >100 days post hatching). We spun wings in mid-downstroke posture and measured lift (L) and drag (D) using a force plate upon which the propeller assembly was mounted. Our findings demonstrate a clear relationship between feather morphology and aerodynamic performance. Independent of size and velocity, older wings with stiffer and more asymmetrical feathers, high numbers of barbicels and a high degree of overlap between barbules generate greater L and L:D ratios than younger wings with flexible, relatively symmetrical and less cohesive feathers. The gradual transition from immature feathers and drag-based performance to more mature feathers and lift-based performance appears to coincide with ontogenetic transitions in locomotor capacity. Younger birds engage in behaviors that require little aerodynamic force and that allow D to contribute to weight support, whereas older birds may expand their behavioral repertoire by flapping with higher tip velocities and generating greater L. Incipient wings are, therefore, uniquely but immediately functional and provide flight-incapable juveniles with access to three-dimensional environments and refugia. Such access may have conferred selective advantages to theropods with protowings during the evolution of avian flight.

Feather pecking and monoamines - a behavioral and neurobiological approach

NARCIS (Netherlands)

Kops, M.S.|info:eu-repo/dai/nl/341590649

2014-01-01

Severe feather pecking (SFP) remains one of the major welfare issues in laying hens. SFP is the pecking at and pulling out of feathers, inflicting damage to the plumage and skin of the recipient. The neurobiological profile determining the vulnerability of individual hens to develop into a severe

Ecomorphology of parasite attachment: experiments with feather lice.

Science.gov (United States)

Bush, Sarah E; Sohn, Edward; Clayton, Dale H

2006-02-01

The host specificity of some parasites can be reinforced by morphological specialization for attachment to mobile hosts. For example, ectoparasites with adaptations for attaching to hosts of a particular size might not be able to remain attached to larger or smaller hosts. This hypothesis is suggested by the positive correlation documented between the body sizes of many parasites and their hosts. We adopted an ecomorphological approach to test the attachment hypothesis. We tested the ability of host-specific feather lice (Phthiraptera: Ischnocera) to attach to 6 novel species of pigeons and doves that vary in size by nearly 2 orders of magnitude. Surprisingly, Rock Pigeon lice (Columbicola columbae) remained attached equally well to all 6 novel host species. We tested the relative importance of 3 factors that could facilitate louse attachment: whole-body insertion, tarsal claw use, and mandible use. Insertion, per se, was not necessary for attachment. However, insertion on coarse feathers of large hosts allowed lice to access feather barbules with their mandibles. Mandible use was a key component of attachment regardless of feather size. Attachment constraints do not appear to reinforce host specificity in this system.

Biomechanics of the Peacock's Display: How Feather Structure and Resonance Influence Multimodal Signaling.

Science.gov (United States)

Dakin, Roslyn; McCrossan, Owen; Hare, James F; Montgomerie, Robert; Amador Kane, Suzanne

2016-01-01

Courtship displays may serve as signals of the quality of motor performance, but little is known about the underlying biomechanics that determines both their signal content and costs. Peacocks (Pavo cristatus) perform a complex, multimodal "train-rattling" display in which they court females by vibrating the iridescent feathers in their elaborate train ornament. Here we study how feather biomechanics influences the performance of this display using a combination of field recordings and laboratory experiments. Using high-speed video, we find that train-rattling peacocks stridulate their tail feathers against the train at 25.6 Hz, on average, generating a broadband, pulsating mechanical sound at that frequency. Laboratory measurements demonstrate that arrays of peacock tail and train feathers have a broad resonant peak in their vibrational spectra at the range of frequencies used for train-rattling during the display, and the motion of feathers is just as expected for feathers shaking near resonance. This indicates that peacocks are able to drive feather vibrations energetically efficiently over a relatively broad range of frequencies, enabling them to modulate the feather vibration frequency of their displays. Using our field data, we show that peacocks with longer trains use slightly higher vibration frequencies on average, even though longer train feathers are heavier and have lower resonant frequencies. Based on these results, we propose hypotheses for future studies of the function and energetics of this display that ask why its dynamic elements might attract and maintain female attention. Finally, we demonstrate how the mechanical structure of the train feathers affects the peacock's visual display by allowing the colorful iridescent eyespots-which strongly influence female mate choice-to remain nearly stationary against a dynamic iridescent background.

Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

Energy Technology Data Exchange (ETDEWEB)

Malik, Riffat Naseem, E-mail: r_n_malik2000@yahoo.co.uk [Environmental Biology Laboratory, Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PO 45320 (Pakistan); Moeckel, Claudia [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Jones, Kevin C.; Hughes, David [Centre for Chemicals Management, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ (United Kingdom)

2011-10-15

Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of {Sigma}PBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher {Sigma}hexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured {Sigma}PBDEs pose no risk to egret population. - Highlights: > Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. > PBDE-47 and -100 frequent in feathers of fish eating egrets. > BDE-99 dominant in feathers of egrets feed in terrestrial habitats. > Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. > Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

International Nuclear Information System (INIS)

Malik, Riffat Naseem; Moeckel, Claudia; Jones, Kevin C.; Hughes, David

2011-01-01

Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of ΣPBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher Σhexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured ΣPBDEs pose no risk to egret population. - Highlights: → Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. → PBDE-47 and -100 frequent in feathers of fish eating egrets. → BDE-99 dominant in feathers of egrets feed in terrestrial habitats. → Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. → Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

An open-data approach for quantifying the potential of taxi ridesharing

DEFF Research Database (Denmark)

Barann, Benjamin; Beverungen, Daniel; Müller, Oliver

2017-01-01

greenhouse gas emissions. We develop a one-to-one TRS approach that matches rides with similar start and end points. We evaluate our approach by analyzing an open dataset of > 5 million taxi trajectories in New York City. Our empirical analysis reveals that the proposed approach matches up to 48.34% of all...... taxi rides, saving 2,892,036 km of travel distance, 231,362.89 l of gas, and 532,134.64 kg of CO2 emissions per week. Compared to many-to-many TRS approaches, our approach is competitive, simpler to implement and operate, and poses less rigid assumptions on data availability and customer acceptance....

Hummingbird with modern feathering: an exceptionally well-preserved Oligocene fossil from southern France

Science.gov (United States)

Louchart, Antoine; Tourment, Nicolas; Carrier, Julie; Roux, Thierry; Mourer-Chauviré, Cécile

2008-02-01

Hummingbirds (Trochilidae) today have an exclusively New World distribution, but their pre-Pleistocene fossil record comes from Europe only. In this study, we describe an exceptionally preserved fossil hummingbird from the early Oligocene of southeastern France. The specimen is articulated, with a completely preserved beak and feathering. Osteological characters allow to identify it as Eurotrochilus sp. This genus is a stem group representative of Trochilidae and was recently described from the early Oligocene of southern Germany. The new fossil reveals that these European Trochilidae were remarkably modern in size, skeletal proportions and the shape of the wing, tail and beak and hyoid bones. These features confirm the early acquisition of the abilities of hovering and nectarivory in hummingbirds, probably before the Oligocene. In several morphological characteristics, they resemble members of the ‘true hummingbirds’ (subfamily Trochilinae) and differ from hermits (Phaethornithinae). These features, which include a short and square tail and a moderately long, almost straight beak, appear to be primitive within the family Trochilidae.

Microstructural tissue-engineering in the rachis and barbs of bird feathers.

Science.gov (United States)

Lingham-Soliar, Theagarten

2017-03-27

Feathers do not have to be especially strong but they do need to be stiff and at the same time resilient and to have a high work of fracture. Syncitial barbule fibres are the highest size-class of continuous filaments in the cortex of the rachis of the feather. However, the rachis can be treated as a generalized cone of rapidly diminishing volume. This means that hundreds of syncitial barbule fibres of the rachis may have to be terminated before reaching the tip - creating potentially thousands of inherently fatal crack-like defects. Here I report a new microstructural architecture of the feather cortex in which most syncitial barbule fibres deviate to the right and left edges of the feather rachis from far within its borders and extend into the barbs, side branches of the rachis, as continuous filaments. This novel morphology adds significantly to knowledge of β-keratin self-assembly in the feather and helps solve the potential problem of fatal crack-like defects in the rachidial cortex. Furthermore, this new complexity, consistent with biology's robust multi-functionality, solves two biomechanical problems at a stroke. Feather barbs deeply 'rooted' within the rachis are also able to better withstand the aerodynamic forces to which they are subjected.

The influence of fixed-route taxi on road accidents and air pollution

Directory of Open Access Journals (Sweden)

V. Fedotov

2006-03-01

Full Text Available The development of market economy in Russia expands the need for movement of groups of people of large mega cities on time to a place at simultaneous reduction of the number of groups with identical purposes. Therefore for many cities a wide use of fixed-route taxis the service of passengers at a constant increase of the numbers of routes and the numbers of transport units was characteristic. At the certain intensity of the movement of fixed-route taxis on separate sites of city highways the transport stream and the changing quality of environment raises the risk of road accident and becomes ecologically unsafe. The results of the estimation of the negative influence of fixed-route taxis in comparison with other categories of vehicles are presented. The research was made on city highways running through the zones with a greater number of cultural and community places, shopping centers and administrative establishments. Perspective ways of the increase of traffic safety and the decrease of concentration of harmful emissions are offered.

Health Status, Intention to Seek Health Examination, and Participation in Health Education Among Taxi Drivers in Jinan, China

Science.gov (United States)

Yang, Yan; Fan, Xiao-sheng; Tian, Cui-huan; Zhang, Wei; Li, Jie; Li, Shu-qing

2014-01-01

Background: Taxi drivers are exposed to various risk factors such as work overload, stress, an irregular diet, and a sedentary lifestyle, which make these individuals vulnerable to many diseases. This study was designed to assess the health status of this occupational group. Objectives: The objective was to explore the health status, the intention to seek health examination, and participation in health education among taxi drivers in Jinan, China. Patients and Methods: The sample-size was determined scientifically. The systematic sampling procedure was used for selecting the sample. Four hundred taxi drivers were randomly selected from several taxi companies in Jinan. In total, 396 valid questionnaires (from 370 males and 26 females) were returned. Health status, intention to seek health examination, and participation in health education were assessed by a self-designed questionnaire. Other personal information including sex, age, ethnicity, marital status, years of employment as a taxi driver, education level, and habits were also collected. Results: This survey revealed that 54.8% of taxi drivers reported illness in the last two weeks and 44.7% of participants reported chronic diseases. The prevalence rates of hypertension, diabetes mellitus, gastroenteritis, arthritis, and heart disease were 18.2%, 8.8%, 26%, 18.4%, and 4.8% of questioned taxi drivers, respectively. Significant self-reported symptoms included fatigue, waist and back pain, headache, dyspepsia, and dry throat affecting 49.7%, 26.2%, 23.5%, 26%, and 27% of participants, respectively. In total, 90.1% of subjects thought that it was necessary to receive a regular health examination. Only 17.9% of subjects had been given information about health education, and significantly, more than 87% of subjects who had been given information about health education reported that the information had been helpful. Conclusions: Taxi drivers’ health was poor in our survey. Thus, using health education interventions

Biomechanics of the Peacock's Display: How Feather Structure and Resonance Influence Multimodal Signaling.

Directory of Open Access Journals (Sweden)

Roslyn Dakin

Full Text Available Courtship displays may serve as signals of the quality of motor performance, but little is known about the underlying biomechanics that determines both their signal content and costs. Peacocks (Pavo cristatus perform a complex, multimodal "train-rattling" display in which they court females by vibrating the iridescent feathers in their elaborate train ornament. Here we study how feather biomechanics influences the performance of this display using a combination of field recordings and laboratory experiments. Using high-speed video, we find that train-rattling peacocks stridulate their tail feathers against the train at 25.6 Hz, on average, generating a broadband, pulsating mechanical sound at that frequency. Laboratory measurements demonstrate that arrays of peacock tail and train feathers have a broad resonant peak in their vibrational spectra at the range of frequencies used for train-rattling during the display, and the motion of feathers is just as expected for feathers shaking near resonance. This indicates that peacocks are able to drive feather vibrations energetically efficiently over a relatively broad range of frequencies, enabling them to modulate the feather vibration frequency of their displays. Using our field data, we show that peacocks with longer trains use slightly higher vibration frequencies on average, even though longer train feathers are heavier and have lower resonant frequencies. Based on these results, we propose hypotheses for future studies of the function and energetics of this display that ask why its dynamic elements might attract and maintain female attention. Finally, we demonstrate how the mechanical structure of the train feathers affects the peacock's visual display by allowing the colorful iridescent eyespots-which strongly influence female mate choice-to remain nearly stationary against a dynamic iridescent background.

Spectral tuning of Amazon parrot feather coloration by psittacofulvin pigments and spongy structures.

Science.gov (United States)

Tinbergen, Jan; Wilts, Bodo D; Stavenga, Doekele G

2013-12-01

The feathers of Amazon parrots are brightly coloured. They contain a unique class of pigments, the psittacofulvins, deposited in both barbs and barbules, causing yellow or red coloured feathers. In specific feather areas, spongy nanostructured barb cells exist, reflecting either in the blue or blue-green wavelength range. The blue-green spongy structures are partly enveloped by a blue-absorbing, yellow-colouring pigment acting as a spectral filter, thus yielding a green coloured barb. Applying reflection and transmission spectroscopy, we characterized the Amazons' pigments and spongy structures, and investigated how they contribute to the feather coloration. The reflectance spectra of Amazon feathers are presumably tuned to the sensitivity spectra of the visual photoreceptors.

Taxi trips distribution modeling based on Entropy-Maximizing theory: A case study in Harbin city-China

Science.gov (United States)

Tang, Jinjun; Zhang, Shen; Chen, Xinqiang; Liu, Fang; Zou, Yajie

2018-03-01

Understanding Origin-Destination distribution of taxi trips is very important for improving effects of transportation planning and enhancing quality of taxi services. This study proposes a new method based on Entropy-Maximizing theory to model OD distribution in Harbin city using large-scale taxi GPS trajectories. Firstly, a K-means clustering method is utilized to partition raw pick-up and drop-off location into different zones, and trips are assumed to start from and end at zone centers. A generalized cost function is further defined by considering travel distance, time and fee between each OD pair. GPS data collected from more than 1000 taxis at an interval of 30 s during one month are divided into two parts: data from first twenty days is treated as training dataset and last ten days is taken as testing dataset. The training dataset is used to calibrate model while testing dataset is used to validate model. Furthermore, three indicators, mean absolute error (MAE), root mean square error (RMSE) and mean percentage absolute error (MPAE), are applied to evaluate training and testing performance of Entropy-Maximizing model versus Gravity model. The results demonstrate Entropy-Maximizing model is superior to Gravity model. Findings of the study are used to validate the feasibility of OD distribution from taxi GPS data in urban system.

Microorganisms associated with feathers of barn swallows in radioactively contaminated areas around chernobyl.

Science.gov (United States)

Czirják, Gábor Arpád; Møller, Anders Pape; Mousseau, Timothy A; Heeb, Philipp

2010-08-01

The Chernobyl catastrophe provides a rare opportunity to study the ecological and evolutionary consequences of low-level, environmental radiation on living organisms. Despite some recent studies about negative effects of environmental radiation on macroorganisms, there is little knowledge about the effect of radioactive contamination on diversity and abundance of microorganisms. We examined abundance patterns of total cultivable bacteria and fungi and the abundance of feather-degrading bacterial subset present on feathers of barn swallows (Hirundo rustica), a colonial migratory passerine, around Chernobyl in relation to levels of ground level environmental radiation. After controlling for confounding variables, total cultivable bacterial loads were negatively correlated with environmental radioactivity, whereas abundance of fungi and feather-degrading bacteria was not significantly related to contamination levels. Abundance of both total and feather-degrading bacteria increased with barn swallow colony size, showing a potential cost of sociality. Males had lower abundance of feather-degrading bacteria than females. Our results show the detrimental effects of low-level environmental radiation on total cultivable bacterial assemblage on feathers, while the abundance of other microorganism groups living on barn swallow feathers, such as feather-degrading bacteria, are shaped by other factors like host sociality or host sex. These data lead us to conclude that the ecological effects of Chernobyl may be more general than previously assumed and may have long-term implications for host-microbe interactions and overall ecosystem functioning.

Replacement Value of Feather Meal for Fishmeal on the ...

African Journals Online (AJOL)

Replacement Value of Feather Meal for Fishmeal on the Performance of Starter Cockerels. ... ratio and feed cost/kg weights gain. Considering the results of final live weight and daily weight gain, it appeared that the 7.5% level of FEM could be the optimal inclusion level feather meal in the diets of growing cockerels.

Genetic analysis of feather pecking behavior in laying hens

NARCIS (Netherlands)

Buitenhuis, A.J.

2003-01-01

This thesis describes the genetic analysis of feather pecking behavior in laying hens. Feather pecking (FP) is a major welfare problem in laying hens.In the European

The preference for high-fiber feed in laying hens divergently selected on feather pecking.

Science.gov (United States)

Kalmendal, R; Bessei, W

2012-08-01

Earlier studies in laying hens have demonstrated a negative correlation between feather pecking and the dietary fiber content of the feed. However, the factors underlying this relationship are not fully understood. In the present experiment, we hypothesized that birds prone to feather pecking would prefer a diet supplemented with dietary fiber. Thus, the aim was to investigate the voluntary consumption of a wheat-soy control diet (CON) and a diet supplemented with 8% spelt hulls (FIB) on the expense of wheat in 20 individually caged hens selected for high feather pecking (HFP) behavior and 20 individually caged hens selected for low feather pecking (LFP) behavior. The proportional intake of FIB was 0.39 and significantly different from 0.50 (Phens (0.36; Phens had inferior plumage condition (Pfeed intake (Phens plucked more feathers from a simple inanimate feather-pecking model, but the number of feathers being pulled out did not correlate with the proportional intake of FIB. It was concluded that the preference for feed supplemented with spelt hulls was different between hens displaying different feather-pecking behavior. The underlying reason for such a difference needs further investigation.

Motorcycle safety among motorcycle taxi drivers and nonoccupational motorcyclists in developing countries: A case study of Maoming, South China.

Science.gov (United States)

Wu, Connor Y H; Loo, Becky P Y

2016-01-01

An increasing number of motorcycle taxis have been involved in traffic crashes in many developing countries. This study examines the characteristics of both motorcycle taxi drivers and nonoccupational motorcyclists, investigates the risks they pose to road safety, and provides recommendations to minimize their risks. Based on the data collected from a questionnaire survey of 867 motorcycle taxi drivers and 2,029 nonoccupational motorcyclists in Maoming, South China, comparisons were made to analyze differences of personal attributes, attitudes toward road safety, and self-reported behavior of the 2 groups. Results of the chi-square tests show that not only motorcycle taxi drivers but also nonoccupational motorcyclists in Maoming held poor attitudes toward road safety and both groups reported unsafe driving behavior. There is much room for improving local road safety education among all motorcyclists in Maoming. Yet, motorcycle taxi drivers were more likely to pose road safety risks than nonoccupational motorcyclists under some circumstances, such as speeding late at night or early in the morning, not requiring passengers to wear helmets, and running a red light. The results of the binary logistic regression model show that possessing a vehicle license for a motorcycle or not was the common significant predictor for unsafe driving behavior of motorcycle taxi drivers and nonoccupational motorcyclists. Therefore, enforcement against all motorcyclists not showing vehicle licenses for their motorcycles should be stepped up. Motorcycle safety is largely poor in Maoming. Therefore, efforts to improve motorcycle safety should be strengthened by targeting not only motorcycle taxi drivers but also nonoccupational motorcyclists.

Variation in immune function, body condition, and feather corticosterone in nestling Tree Swallows (Tachycineta bicolor) on reclaimed wetlands in the Athabasca oil sands, Alberta, Canada

International Nuclear Information System (INIS)

Jane Harms, N.; Fairhurst, Graham D.; Bortolotti, Gary R.; Smits, Judit E.G.

2010-01-01

In the Athabasca oil sands region of northern Alberta, mining companies are evaluating reclamation using constructed wetlands for integration of tailings. From May to July 2008, reproductive performance of 40 breeding pairs of tree swallows (Tachycineta bicolor), plus growth and survival of nestlings, was measured on three reclaimed wetlands on two oil sands leases. A subset of nestlings was examined for i) feather corticosterone levels, ii) delayed-type hypersensitivity response, and iii) innate immune function. Nestlings on one of two wetlands created with oil sands process affected material (OSPM) were heavier and had greater wing-lengths, and mounted a stronger delayed-type hypersensitivity response compared those on the reference wetland. Corticosterone was significantly higher in male nestlings on one of two OSPM-containing wetland compared to the reference wetland. Body condition of 12-day-old female nestlings was inversely related to feather corticosterone. Under ideal weather conditions, reclaimed wetlands can support healthy populations of aerially-insectivorous birds. - Under ideal weather conditions, tree swallow nestlings on reclaimed OSPM-affected wetlands are in good body condition and mount strong cell-mediated immune responses.

A trade-off between reproduction and feather growth in the barn swallow (Hirundo rustica.

Directory of Open Access Journals (Sweden)

Nicola Saino

Full Text Available Physiological trade-offs mediated by limiting energy, resources or time constrain the simultaneous expression of major functions and can lead to the evolution of temporal separation between demanding activities. In birds, plumage renewal is a demanding activity, which accomplishes fundamental functions, such as allowing thermal insulation, aerodynamics and socio-sexual signaling. Feather renewal is a very expensive and disabling process, and molt is often partitioned from breeding and migration. However, trade-offs between feather renewal and breeding have been only sparsely studied. In barn swallows (Hirundo rustica breeding in Italy and undergoing molt during wintering in sub-Saharan Africa, we studied this trade-off by removing a tail feather from a large sample of individuals and analyzing growth bar width, reflecting feather growth rate, and length of the growing replacement feather in relation to the stage in the breeding cycle at removal and clutch size. Growth bar width of females and length of the growing replacement feather of both sexes were smaller when the original feather had been removed after clutch initiation. Importantly, in females both growth bar width and replacement feather length were negatively predicted by clutch size, and more strongly so for large clutches and when feather removal occurred immediately after clutch completion. Hence, we found strong, coherent evidence for a trade-off between reproduction, and laying effort in particular, and the ability to generate new feathers. These results support the hypothesis that the derived condition of molting during wintering in long-distance migrants is maintained by the costs of overlapping breeding and molt.

Comparison between internal combustion engines and simulated electrical propulsion of taxis; Vergleich zwischen verbrennungsmotorischem und simuliertem elektrischen Antrieb von Taxis

Energy Technology Data Exchange (ETDEWEB)

Wallner, Stefan [Stefan Wallner Energietechnik, Unterhaching (Germany); Thym, Jochen

2011-03-15

The term 'triumphal procession of electromobility' produces an enormous expectation at the end users side, but intensive development work has still to be done. The transition from today's vehicles towards electric propulsion is not to be expected to take place overnight but will start with slot applications. Energietechnik Wallner has analysed the potential of taxis. (orig.)

Effects of oil and oil burn residues on seabird feathers

DEFF Research Database (Denmark)

Fritt-Rasmussen, Janne; Linnebjerg, Jannie Fries; Sørensen, Martin X.

2016-01-01

It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified....... To protect seabirds, a rapid removal of oil is crucial and in situ burning could be an efficient method. In the present work exposure effects of oil and burn residue in different doses was studied on seabird feathers from legally hunted Common eider (Somateria mollissima) by examining changes in total weight...... of the feather and damages on the microstructure (Amalgamation Index) of the feathers before and after exposure. The results of the experiments indicate that burn residues from in situ burning of an oil spill have similar or larger fouling and damaging effects on seabird feathers, as compared to fresh oil....

Feather development genes and associated regulatory innovation predate the origin of Dinosauria.

Science.gov (United States)

Lowe, Craig B; Clarke, Julia A; Baker, Allan J; Haussler, David; Edwards, Scott V

2015-01-01

The evolution of avian feathers has recently been illuminated by fossils and the identification of genes involved in feather patterning and morphogenesis. However, molecular studies have focused mainly on protein-coding genes. Using comparative genomics and more than 600,000 conserved regulatory elements, we show that patterns of genome evolution in the vicinity of feather genes are consistent with a major role for regulatory innovation in the evolution of feathers. Rates of innovation at feather regulatory elements exhibit an extended period of innovation with peaks in the ancestors of amniotes and archosaurs. We estimate that 86% of such regulatory elements and 100% of the nonkeratin feather gene set were present prior to the origin of Dinosauria. On the branch leading to modern birds, we detect a strong signal of regulatory innovation near insulin-like growth factor binding protein (IGFBP) 2 and IGFBP5, which have roles in body size reduction, and may represent a genomic signature for the miniaturization of dinosaurian body size preceding the origin of flight. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

INFLUENCE OF SERVICE QUALITY AND FARE TOWARD CUSTOMER SATISFACTION AND ITS IMPACT ON CUSTOMER LOYALTY OF EXPRESS TAXI IN JAKARTA

Directory of Open Access Journals (Sweden)

Mohammad Rizan

2015-09-01

Full Text Available The purpose of this study was to: to examine empirically the effect of service quality to customer satisfaction on Express taxi, to examine empirically the effect of fare to customer satisfaction on Express taxi, to examine empirically the effect of customer satisfaction to customer loyalty on Express taxi, to examine empirically the effect of service quality to customer loyalty on Express taxi, and to examine empirically the effect of fare to customer loyalty on Express taxi. Data collection using survey methods. Sample of this study are 200 respondents who have using services of Express taxi more than two times in last three months. Data analysis using SPSS version 23 and SEM (Structural Equation Modeling LISREL version 8.7. Results of hypothesis testing showed: service quality have positive and significant effect on customer satisfaction, fare have positive and significant effect on customer satisfaction, customer satisfaction have positive and significant effect on customer loyalty, service quality have positive and not significant effect to on customer loyalty. fare have positive and significant effect to on customer loyalty. Rated fit model with value of RMSEA 0.043, value of RMR 0.043, value of CMIN/DF 1.88, value of NFI 0.96, value of NNFI 0.98, and value of CFI 0.98. The results of this research beneficial to transportation company, especially Express taxi in Jakarta, to create better strategy in improving customer loyalty.

Research on the Coordinated Design of Bus and Taxi Station

Directory of Open Access Journals (Sweden)

Jiangfeng Xi

2015-01-01

Full Text Available Rises in the number of transit buses, bus routes, and overall traffic volume in China’s cities, coupled with interference from other transport modes, such as taxis loading and unloading passengers nearby, have led to increasing traffic delays at bus stops, which is considered one of the factors degrading service levels and traffic operations on urban roadways. This paper studies traffic characteristics at bus stops, investigates variations in delay from different types or designs of bus stops, and analyzes the impact of it on traffic capacity, the purpose of which is to propose a solution to predicting the feasibility of an integrated design of bus stops and taxi stands with the help of mathematical models and based on the objectives of optimal traffic operations and passenger transfer.

THE ROUTE DETERMINATION OF FILING A TAXI TO THE CUSTOMER IN TERMS OF FUNCTIONING OF THE AUTOMATED CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

Yu. O. Davidich

2008-03-01

Full Text Available The issues of overall performance increase of taxi transport due to improvement of automated system of dispatching management by its technological processes are considered. The route of taxi submission to a customer is offered to be determined by a criterion of minimum time. To solve the given task the taxi submission route determination technique is developed. It will promote the reduction of passengers’ waiting time and the decrease in operational expenses of a carrier.

Automation of orders in taxi service

OpenAIRE

Simčič, Matej

2012-01-01

Automation is rapidly growing in the last years. The advantages it brings are cost reduction, faster and better performance of tasks that would be otherwise done by humas. It began in the manufacturing industry and later expanded to other sectors. Today's technology allows the implementation of automation in a wide range of areas. The thesis deals with the implementation of a system that allows automated ordering of a taxi. The system consists of four components. They are two mobile app...

Does feather corticosterone reflect individual quality or external stress in arctic-nesting migratory birds?

Science.gov (United States)

Legagneux, Pierre; Harms, N Jane; Gauthier, Gilles; Chastel, Olivier; Gilchrist, H Grant; Bortolotti, Gary; Bêty, Joël; Soos, Catherine

2013-01-01

The effects of environmental perturbations or stressors on individual states can be carried over to subsequent life stages and ultimately affect survival and reproduction. The concentration of corticosterone (CORT) in feathers is an integrated measure of hypothalamic-pituitary-adrenal activity during the molting period, providing information on the total baseline and stress-induced CORT secreted during the period of feather growth. Common eiders and greater snow geese replace all flight feathers once a year during the pre-basic molt, which occurs following breeding. Thus, CORT contained in feathers of pre-breeding individuals sampled in spring reflects the total CORT secreted during the previous molting event, which may provide insight into the magnitude or extent of stress experienced during this time period. We used data from multiple recaptures to disentangle the contribution of individual quality vs. external factors (i.e., breeding investment or environmental conditions) on feather CORT in arctic-nesting waterfowl. Our results revealed no repeatability of feather CORT within individuals of either species. In common eiders, feather CORT was not affected by prior reproductive investment, nor by pre-breeding (spring) body condition prior to the molting period. Individual feather CORT greatly varied according to the year, and August-September temperatures explained most of the annual variation in feather CORT. Understanding mechanisms that affect energetic costs and stress responses during molting will require further studies either using long-term data or experiments. Although our study period encompassed only five years, it nonetheless provides evidence that CORT measured in feathers likely reflects responses to environmental conditions experienced by birds during molt, and could be used as a metric to study carry-over effects.

Does feather corticosterone reflect individual quality or external stress in arctic-nesting migratory birds?

Directory of Open Access Journals (Sweden)

Pierre Legagneux

Full Text Available The effects of environmental perturbations or stressors on individual states can be carried over to subsequent life stages and ultimately affect survival and reproduction. The concentration of corticosterone (CORT in feathers is an integrated measure of hypothalamic-pituitary-adrenal activity during the molting period, providing information on the total baseline and stress-induced CORT secreted during the period of feather growth. Common eiders and greater snow geese replace all flight feathers once a year during the pre-basic molt, which occurs following breeding. Thus, CORT contained in feathers of pre-breeding individuals sampled in spring reflects the total CORT secreted during the previous molting event, which may provide insight into the magnitude or extent of stress experienced during this time period. We used data from multiple recaptures to disentangle the contribution of individual quality vs. external factors (i.e., breeding investment or environmental conditions on feather CORT in arctic-nesting waterfowl. Our results revealed no repeatability of feather CORT within individuals of either species. In common eiders, feather CORT was not affected by prior reproductive investment, nor by pre-breeding (spring body condition prior to the molting period. Individual feather CORT greatly varied according to the year, and August-September temperatures explained most of the annual variation in feather CORT. Understanding mechanisms that affect energetic costs and stress responses during molting will require further studies either using long-term data or experiments. Although our study period encompassed only five years, it nonetheless provides evidence that CORT measured in feathers likely reflects responses to environmental conditions experienced by birds during molt, and could be used as a metric to study carry-over effects.

Kingfisher feathers--colouration by pigments, spongy nanostructures and thin films.

Science.gov (United States)

Stavenga, Doekele G; Tinbergen, Jan; Leertouwer, Hein L; Wilts, Bodo D

2011-12-01

The colours of the common kingfisher, Alcedo atthis, reside in the barbs of the three main types of feather: the orange breast feathers, the cyan back feathers and the blue tail feathers. Scanning electron microscopy showed that the orange barbs contain small pigment granules. The cyan and blue barbs contain spongy nanostructures with slightly different dimensions, causing different reflectance spectra. Imaging scatterometry showed that the pigmented barbs create a diffuse orange scattering and the spongy barb structures create iridescence. The extent of the angle-dependent light scattering increases with decreasing wavelength. All barbs have a cortical envelope with a thickness of a few micrometres. The reflectance spectra of the cortex of the barbs show oscillations when measured from small areas, but when measured from larger areas the spectra become wavelength independent. This can be directly understood with thin film modelling, assuming a somewhat variable cortex thickness. The cortex reflectance appears to be small but not negligible with respect to the pigmentary and structural barb reflectance.

76 FR 65769 - Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority

Science.gov (United States)

2011-10-24

... DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority AGENCY: Department of Transportation. ACTION: Notice of Order to... issued to Friendship Airways, Inc. d/b/a Yellow Air Taxi and deny its application to resume commuter...

A hybrid life cycle and multi-criteria decision analysis approach for identifying sustainable development strategies of Beijing's taxi fleet

International Nuclear Information System (INIS)

Cai, Yanpeng; Applegate, Scott; Yue, Wencong; Cai, Jianying; Wang, Xuan; Liu, Gengyuan; Li, Chunhui

2017-01-01

To identify and evaluate sustainable strategies of taxi fleet in Beijing in terms of economic, policy, and environmental implications, a hybrid approach was developed through incorporating multi-criteria decision analysis (MCDA) methods within a general life-cycle analysis (LCA) framework. The approach can (a) help comprehensive evaluate environmental impacts of multiple types of vehicles, (b) facilitate analysis of environmental, economic and policy features of such vehicles, and (c) identify desirable taxi fleet development strategies for the city. The developed approach represented an improvement of the decision-making capability for taxi implementation based on multiple available technologies and their performance that can be specifically tailored to Beijing. The results demonstrated that the proposed approach could comprehensively reflect multiple implications of strategies for the taxi fleet in Beijing to reduce air pollution in the city. The results also indicated that the electric vehicle powered with the year 2020 electricity projections would be the ideal solution, outranking the other alternatives. The conventional vehicle ranked the lowest among the alternatives. The plug-in hybrid vehicle powered by 2020 electricity projects ranked the third, followed by the plug-in hybrid vehicle ranking the fourth, and the hybrid vehicle ranking the fifth. - Highlights: • An hybrid approach was proposed for evaluating sustainable strategies of Beijing's taxi fleet. • This approach was based on the combination of multi-criteria decision analysis methods and life-cycle assessment. • Environmental, economic and policy performances of multiple strategies were compared. • Detailed responses of taxi drivers and local residents were interviewed. • The electric vehicle would be the ideal solution for Beijing Taxi fleet.

Selection on feather pecking affects response to novelty and foraging behaviour in laying hens

DEFF Research Database (Denmark)

de Haas, Elske N; Nielsen, Birte L; Buitenhuis, A J (Bart)

2010-01-01

in the maze for 10 min during which they could choose to eat from all available food-items. When exposed for the first time in the maze HFP birds walked a longer distance, vocalized sooner and had more exploratory pecks compared to LFP birds who showed more wing-movements and defecations. When given a choice......' fear-responses to a novel barren environment. Hereafter, birds were trained three times in the maze with four different food-items that were offered in one of the four arms (i.e. regular food-pellets, feathers, grass, and mealworms hidden in wood-shavings). On the fifth day, birds were tested...... of food inside the maze both lines preferred eating worms, but HFP birds had more worm-eating bouts and ate faster than LFP birds. The results of this study indicate that HFP birds respond actively to fear-eliciting situations, which may originate from a proactive coping style. Instead of a clear...

Forward flight of swallowtail butterfly with simple flapping motion

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Hiroto [School of Engineering and Applied Sciences, Harvard University, 60 Oxford Street, Cambridge, MA 02138 (United States); Shimoyama, Isao, E-mail: isao@i.u-tokyo.ac.j [Department of Mechano-Informatics, Graduate School of Information Science and Technology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan)

2010-06-15

Unlike other flying insects, the wing motion of swallowtail butterflies is basically limited to flapping because their fore wings partly overlap their hind wings, structurally restricting the feathering needed for active control of aerodynamic force. Hence, it can be hypothesized that the flight of swallowtail butterflies is realized with simple flapping, requiring little feedback control of the feathering angle. To verify this hypothesis, we fabricated an artificial butterfly mimicking the wing motion and wing shape of a swallowtail butterfly and analyzed its flights using images taken with a high-speed video camera. The results demonstrated that stable forward flight could be realized without active feathering or feedback control of the wing motion. During the flights, the artificial butterfly's body moved up and down passively in synchronization with the flapping, and the artificial butterfly followed an undulating flight trajectory like an actual swallowtail butterfly. Without feedback control of the wing motion, the body movement is directly affected by change of aerodynamic force due to the wing deformation; the degree of deformation was determined by the wing venation. Unlike a veinless wing, a mimic wing with veins generated a much higher lift coefficient during the flapping flight than in a steady flow due to the large body motion.

Forward flight of swallowtail butterfly with simple flapping motion

International Nuclear Information System (INIS)

Tanaka, Hiroto; Shimoyama, Isao

2010-01-01

Unlike other flying insects, the wing motion of swallowtail butterflies is basically limited to flapping because their fore wings partly overlap their hind wings, structurally restricting the feathering needed for active control of aerodynamic force. Hence, it can be hypothesized that the flight of swallowtail butterflies is realized with simple flapping, requiring little feedback control of the feathering angle. To verify this hypothesis, we fabricated an artificial butterfly mimicking the wing motion and wing shape of a swallowtail butterfly and analyzed its flights using images taken with a high-speed video camera. The results demonstrated that stable forward flight could be realized without active feathering or feedback control of the wing motion. During the flights, the artificial butterfly's body moved up and down passively in synchronization with the flapping, and the artificial butterfly followed an undulating flight trajectory like an actual swallowtail butterfly. Without feedback control of the wing motion, the body movement is directly affected by change of aerodynamic force due to the wing deformation; the degree of deformation was determined by the wing venation. Unlike a veinless wing, a mimic wing with veins generated a much higher lift coefficient during the flapping flight than in a steady flow due to the large body motion.

Predicting Taxi-Out Time at Congested Airports with Optimization-Based Support Vector Regression Methods

Directory of Open Access Journals (Sweden)

Guan Lian

2018-01-01

Full Text Available Accurate prediction of taxi-out time is significant precondition for improving the operationality of the departure process at an airport, as well as reducing the long taxi-out time, congestion, and excessive emission of greenhouse gases. Unfortunately, several of the traditional methods of predicting taxi-out time perform unsatisfactorily at congested airports. This paper describes and tests three of those conventional methods which include Generalized Linear Model, Softmax Regression Model, and Artificial Neural Network method and two improved Support Vector Regression (SVR approaches based on swarm intelligence algorithm optimization, which include Particle Swarm Optimization (PSO and Firefly Algorithm. In order to improve the global searching ability of Firefly Algorithm, adaptive step factor and Lévy flight are implemented simultaneously when updating the location function. Six factors are analysed, of which delay is identified as one significant factor in congested airports. Through a series of specific dynamic analyses, a case study of Beijing International Airport (PEK is tested with historical data. The performance measures show that the proposed two SVR approaches, especially the Improved Firefly Algorithm (IFA optimization-based SVR method, not only perform as the best modelling measures and accuracy rate compared with the representative forecast models, but also can achieve a better predictive performance when dealing with abnormal taxi-out time states.

Integration of electric vehiclesin cooper atives taxi ambato. Ecuador

Directory of Open Access Journals (Sweden)

Mery Esperanza Ruiz Guajala

2015-11-01

Full Text Available The transition from combustion vehicles towards a new electrical system friendly to the environment, is a decision to be taken by carrier based on cost-benefit analysis which generates buying it, and contribute to society not only for the service they provide, but to prevent air pollution we breathe, and if we add the future energy supply, since the Ecuadorian State in 2016 will provide the whole country of this important resource. The study focuses on two parts: the first on surveys of taxi owners to describe their perception of the integration of electric vehicles, and the second in determining the economic and financial feasibility of acquiring the vehicle Nissan Leaf by the member of the cooperative taxi. The most important conclusion is that the carriers are willing to buy an electric vehicle to mitigate the emission of toxic gases, and that its decision would save 50% in annual operating costs of your vehicle.

The Effect of Working Conditions to the Health Status in Taxi and Bus Drivers in Canakkale, Turkey; Community Based Study

Directory of Open Access Journals (Sweden)

Aysegul Uludag

2016-04-01

Full Text Available Aim: The growing taxi and bus driver workforce is at risk for poor health status, obesity, hypertension, metabolic syndrome and with increased risk for cardiovascular disease. We aimed to determine the relationship between working conditions and health status in taxi and bus drivers. Material and Method: This study is a descriptive study. The population of the study was taxi and bus drivers in central of Canakkale. There were total 250 taxi and bus drivers who registered in The Chamber of Canakkale Drivers and Vehicle. We reached the 70 taxi drivers and 93 bus drivers. The participants were visited at their workplace. We performed the questionnaire that include the socio-demografic features, habits, the working conditions. We evaluated the blood pressure, waist-hip measurements and capillary blood glucose at any time. Results: Total of the 163 men drivers were enrolled the study. Nine (12.9% taxi drivers and 6 (6.5% bus drivers were hipertensive, and 1 taxi driver and 2 bus drivers with random capillary blood glucose levels higher than 200 mg. The prevalence of hypertension was 9.2%, diabetes mellitus was 1.8, obesity was 49.4%. Discussion: Drivers have many risk factors for CVD like stress and immobility. In our study, the socio-demografic and working conditions are limited for explaining the risk for hipertension, diabetes mellitus and obesity in drivers in Canakkale. These study have to be done in metropolitan cities. In this aspect, the drivers can be evaluated in their own living spaces and working conditions.

Biomechanics of the Peacock’s Display: How Feather Structure and Resonance Influence Multimodal Signaling

Science.gov (United States)

Dakin, Roslyn; McCrossan, Owen; Hare, James F.; Montgomerie, Robert; Amador Kane, Suzanne

2016-01-01

Courtship displays may serve as signals of the quality of motor performance, but little is known about the underlying biomechanics that determines both their signal content and costs. Peacocks (Pavo cristatus) perform a complex, multimodal “train-rattling” display in which they court females by vibrating the iridescent feathers in their elaborate train ornament. Here we study how feather biomechanics influences the performance of this display using a combination of field recordings and laboratory experiments. Using high-speed video, we find that train-rattling peacocks stridulate their tail feathers against the train at 25.6 Hz, on average, generating a broadband, pulsating mechanical sound at that frequency. Laboratory measurements demonstrate that arrays of peacock tail and train feathers have a broad resonant peak in their vibrational spectra at the range of frequencies used for train-rattling during the display, and the motion of feathers is just as expected for feathers shaking near resonance. This indicates that peacocks are able to drive feather vibrations energetically efficiently over a relatively broad range of frequencies, enabling them to modulate the feather vibration frequency of their displays. Using our field data, we show that peacocks with longer trains use slightly higher vibration frequencies on average, even though longer train feathers are heavier and have lower resonant frequencies. Based on these results, we propose hypotheses for future studies of the function and energetics of this display that ask why its dynamic elements might attract and maintain female attention. Finally, we demonstrate how the mechanical structure of the train feathers affects the peacock’s visual display by allowing the colorful iridescent eyespots–which strongly influence female mate choice–to remain nearly stationary against a dynamic iridescent background. PMID:27119380

Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution.

Science.gov (United States)

Bell, Phil R; Campione, Nicolás E; Persons, W Scott; Currie, Philip J; Larson, Peter L; Tanke, Darren H; Bakker, Robert T

2017-06-01

Recent evidence for feathers in theropods has led to speculations that the largest tyrannosaurids, including Tyrannosaurus rex , were extensively feathered. We describe fossil integument from Tyrannosaurus and other tyrannosaurids ( Albertosaurus, Daspletosaurus, Gorgosaurus and Tarbosaurus ), confirming that these large-bodied forms possessed scaly, reptilian-like skin. Body size evolution in tyrannosauroids reveals two independent occurrences of gigantism; specifically, the large sizes in Yutyrannus and tyrannosaurids were independently derived. These new findings demonstrate that extensive feather coverings observed in some early tyrannosauroids were lost by the Albian, basal to Tyrannosauridae. This loss is unrelated to palaeoclimate but possibly tied to the evolution of gigantism, although other mechanisms exist. © 2017 The Author(s).

The Aircraft Electric Taxi System: A Qualitative Multi Case Study

Science.gov (United States)

Johnson, Thomas Frank

The problem this research addresses is the airline industry, and the seemingly unwillingness attitude towards adopting ways to taxi aircraft without utilizing thrust from the main engines. The purpose of the study was to get a better understanding of the decision-making process of airline executives, in respect to investing in cost saving technology. A qualitative research method is used from personal interviews with 24 airline executives from two major U.S. airlines, related industry journal articles, and aircraft performance data. The following three research questions are addressed. RQ1. Does the cost of jet fuel influence airline executives' decision of adopting the aircraft electric taxi system technology? RQ2 Does the measurable payback period for a return on investment influence airline executives' decision of adopting ETS technology? RQ3. Does the amount of government assistance influence airline executives' decision of adopting ETS technology? A multi case research study design is used with a triangulation technique. The participant perceptions indicate the need to reduce operating costs, they have concerns about investment risk, and they are in favor of future government sponsored performance improvement projects. Based on the framework, findings and implications of this study, a future research paper could focus on the positive environmental effects of the ETS application. A study could be conducted on current airport area air quality and the effects that aircraft main engine thrust taxiing has on the surrounding air quality.

Using an innovative price model to leverage the business model – The case of price model innovation in the largest Swedish taxi company

Directory of Open Access Journals (Sweden)

Carl-Johan Petri

2014-08-01

Full Text Available Purpose: The purpose of the paper is to describe how the biggest Swedish taxi company (Taxi Kurir developed an innovative price model to leverage the business model. Design/methodology/approach : The empirical data in the article describe Taxi Kurir’s development of a new price model. Data about the Swedish taxi market and about Taxi Kurir has been compiled though interviews and document studies. Detailed information about the background, development and implementation of Taxi Kurir’s new price model has been captured through interviews with representatives from Taxi Kurir. Findings : Based on both the empirical example, and other investigations, we have found that a company can create substantial changes in their price model, by just changing some of its basic characteristics. A well designed price model can contribute to leveraging the intentions of the business model. Practical implications : Most academic and practical texts about business models consider pricing to be an important component. However, they typically do not refer to the specifics of the price- or revenue models. According to the literature review in this paper, and the empirical findings, the configuration of a company’s price model should be aligned with its business model. This will contribute to leveraging the business model. Originality/value: The Swedish taxi market is one of the most deregulated in the world. Differently from most other countries, any individual or company can start and operate a taxi business. This case offers a unique description on how the biggest company in the market responded to the competition by introducing a fundamentally new price model, by making a small change in one of the dimensions in their existing price model.

Modeling of the service taxi

Directory of Open Access Journals (Sweden)

R. M. Bezborodnikova

2016-01-01

Full Text Available Modeling and optimization business processes are ongoing challenges of modernity. Based on the study of business processes to anticipate and avoid many problems in the work of companies linked primarily with an increased level of costs, the low quality of the performed works and manufactured products, excessive run time functions. Application of simulation tool for business processes allows at the stage of planning to assess various indicators of the effectiveness of processes to identify the best sequence of functions, determine resource costs to calculate personnel workload, thereby facilitating timely adoption of the correct administrative decisions. The article deals with the modeling of the business process “Order processing” taxi service Heat the city of Orenburg. Based on the methodology of modeling Business Process Model and Notation (BPMN built functional diagram of the business process (with freely distributed software product Bizagi Modeler, given the resources used, the costs of their use, built calendar schedules. Next, the operation was carried out simulations with different process input data: the number of incoming applications, the number of controllers and advertising budget. It is shown that the efficiency of the business process will contribute to the increase in the total number of dispatchers up to 6 people, as well as increasing advertising costs doubled. As a result of the decisions taken is expected to increase the net income of the company to 76 794 RUR and the average salary of the staff (in particular taxi drivers to 42 281 RUR, dispatchers and 22 799 RUR, as well as reducing the duration of processing a single order up to 31 minutes.

The xylanase inhibitor TAXI-III counteracts the necrotic activity of a Fusarium graminearum xylanase in vitro and in durum wheat transgenic plants.

Science.gov (United States)

Moscetti, Ilaria; Faoro, Franco; Moro, Stefano; Sabbadin, Davide; Sella, Luca; Favaron, Francesco; D'Ovidio, Renato

2015-08-01

The xylanase inhibitor TAXI-III has been proven to delay Fusarium head blight (FHB) symptoms caused by Fusarium graminearum in transgenic durum wheat plants. To elucidate the molecular mechanism underlying the capacity of the TAXI-III transgenic plants to limit FHB symptoms, we treated wheat tissues with the xylanase FGSG_03624, hitherto shown to induce cell death and hydrogen peroxide accumulation. Experiments performed on lemmas of flowering wheat spikes and wheat cell suspension cultures demonstrated that pre-incubation of xylanase FGSG_03624 with TAXI-III significantly decreased cell death. Most interestingly, a reduced cell death relative to control non-transgenic plants was also obtained by treating, with the same xylanase, lemmas of TAXI-III transgenic plants. Molecular modelling studies predicted an interaction between the TAXI-III residue H395 and residues E122 and E214 belonging to the active site of xylanase FGSG_03624. These results provide, for the first time, clear indications in vitro and in planta that a xylanase inhibitor can prevent the necrotic activity of a xylanase, and suggest that the reduced FHB symptoms on transgenic TAXI-III plants may be a result not only of the direct inhibition of xylanase activity secreted by the pathogen, but also of the capacity of TAXI-III to avoid host cell death. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Outsourcing of Defense Supply Center, Columbus, Bus and Taxi Service Operations

National Research Council Canada - National Science Library

Granetto, Paul

1999-01-01

Introduction. We performed the audit in response to allegations to the Defense Hotline that the Defense Supply Center, Columbus, outsourcing study for bus and taxi service operations was based on incorrect methodology...

Hydrophobic duck feathers and their simulation on textile substrates for water repellent treatment

International Nuclear Information System (INIS)

Liu Yuyang; Chen Xianqiong; Xin, J H

2008-01-01

Inspired by the non-wetting phenomena of duck feathers, the water repellent property of duck feathers was studied at the nanoscale. The microstructures of the duck feather were investigated by a scanning electron microscope (SEM) imaging method through a step-by-step magnifying procedure. The SEM results show that duck feathers have a multi-scale structure and that this multi-scale structure as well as the preening oil are responsible for their super hydrophobic behavior. The microstructures of the duck feather were simulated on textile substrates using the biopolymer chitosan as building blocks through a novel surface solution precipitation (SSP) method, and then the textile substrates were further modified with a silicone compound to achieve low surface energy. The resultant textiles exhibit super water repellent properties, thus providing a simple bionic way to create super hydrophobic surfaces on soft substrates using flexible material as building blocks

Keratin Production by Decomposing Feather Waste Using Some Local Bacillus spp. Isolated from Poultry Soil

Directory of Open Access Journals (Sweden)

Mojtaba Salouti

2016-12-01

Full Text Available Background: Feather waste is generated in large amounts as a by-product of commercial poultry processing. The main component of feather is keratin. The main purpose of this study was to identify Bacillus spp. (the keratinolytic bacteria that are able to degrade the feather for producing keratin. Methods: Bacillus spp. Were isolated from the waste of poultries located in Miyaneh city. The bacteria were grown on basal medium containing 1% hen feather as the sole source of carbon ,nitrogen, sulfur and energy at 27ºC for 7 days. Then,the isolates capable of feather degrading were identified. The Bradford method was used to assay the production of keratin in the feather samples. Different pH and temperatures were studied to determine the best conditions for production of keratinase enzyme. Results: Seven Bacillus spp. including: B. pumilis, B. subtilis, B. firmus, B. macerance, B. popilliae, B. lentimorbus and B. larvae were found to be able to degrade the feather with different abilities. Conclusion: B. subtilis was found to be most productive isolate for keratinase enzyme production.

Feather pecking in growers: a study with individually marked birds

DEFF Research Database (Denmark)

Wechsler, B; Huber-Eicher, B; Nash, David Richard

1998-01-01

1. The aim of the present study was to investigate whether individual birds specialise in feather pecking. Growers were individually marked and reared in groups of 30 or 31 in pens with a slatted floor. At an age of 4 to 6 weeks feather pecking was frequent in all pens. 2. On average 83% of all g...

Fifty shades of white: how white feather brightness differs among species

Science.gov (United States)

Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D.

2018-04-01

White colouration is a common and important component of animal visual signalling and camouflage, but how and why it varies across species is poorly understood. White is produced by wavelength-independent and diffuse scattering of light by the internal structures of materials, where the degree of brightness is related to the amount of light scattered. Here, we investigated the morphological basis of brightness differences among unpigmented pennaceous regions of white body feathers across 61 bird species. Using phylogenetically controlled comparisons of reflectance and morphometric measurements, we show that brighter white feathers had larger and internally more complex barbs than duller white feathers. Higher brightness was also associated with more closely packed barbs and barbules, thicker and longer barbules, and rounder and less hollow barbs. Larger species tended to have brighter white feathers than smaller species because they had thicker and more complex barbs, but aquatic species were not significantly brighter than terrestrial species. As similar light scattering principals affect the brightness of chromatic signals, not just white colours, these findings help broaden our general understanding of the mechanisms that affect plumage brightness. Future studies should examine how feather layering on a bird's body contributes to differences between brightness of white plumage patches within and across species.

Study of chemisrty and hydrolysates drying parameters of feather-downy raw material

OpenAIRE

LISITSYN A.B.; KRIGER O.V.; MITROKHIN P.V.

2016-01-01

The article describes chemical and amino acid composition of feather-downy raw material. It determines the mass fraction of crude protein, crude fiber, ash, calcium, phosphorus, sodium in the samples of feather-downy raw material. It is stated that the waste from poultry processing obtained from hens of all the studied species are characterized by a high content of crude protein and low in crude fiber and ash. The most valuable feather-downy raw material regarding protein is waste containing ...

Anaerobic digestion of chicken feather with swine manure or slaughterhouse sludge for biogas production.

Science.gov (United States)

Xia, Yun; Massé, Daniel I; McAllister, Tim A; Beaulieu, Carole; Ungerfeld, Emilio

2012-03-01

Biogas production from anaerobic digestion of chicken feathers with swine manure or slaughterhouse sludge was assessed in two separate experiments. Ground feathers without any pre-treatment were added to 42-L digesters inoculated with swine manure or slaughterhouse sludge, representing 37% and 23% of total solids, respectively and incubated at 25°C in batch mode. Compared to the control without feather addition, total CH(4) production increased by 130% (Pswine manure and the slaughterhouse sludge digesters, respectively. Mixed liquor NH(4)N concentration increased (Pdigestion to 6.9 and 3.5 g/L at the end of digestion in the swine manure and the slaughterhouse sludge digesters, respectively. The fraction of proteolytic microorganisms increased (Pdigestion from 12.5% to 14.5% and 11.3% to 13.0% in the swine manure and the slaughterhouse sludge digesters with feather addition, respectively, but decreased in the controls. These results are reflective of feather digestion. Feather addition did not affect CH(4) yields of the swine manure digesters (P=0.082) and the slaughterhouse sludge digesters (P=0.21), indicating that feathers can be digested together with swine manure or slaughterhouse sludge without negatively affecting the digestion of swine manure and slaughterhouse sludge. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Factor Analysis of Passenger Cars Using as a Taxi

Directory of Open Access Journals (Sweden)

Deriugin O.V.

2016-05-01

Full Text Available A procedure to select passenger cars has been proposed. The procedure helps substantiate choice of effective transportation means in accordance with taxi class to meet consumption requirements of those taking part in transportation process from the viewpoint of comfort, safety, and minimum expenditures in the context of such transportation type.

Spatio-temporal pattern formation in predator-prey systems with fitness taxis

DEFF Research Database (Denmark)

Heilmann, Irene T.; Thygesen, Uffe Høgsbro; Sørensen, Mads Peter

2018-01-01

We pose a spatial predator–prey model in which the movement of animals is not purely diffusive, but also contains a drift term in the direction of higher specific growth rates. We refer to this as fitness taxis. We conduct a linear stability analysis of the resulting coupled reaction–advection–di......We pose a spatial predator–prey model in which the movement of animals is not purely diffusive, but also contains a drift term in the direction of higher specific growth rates. We refer to this as fitness taxis. We conduct a linear stability analysis of the resulting coupled reaction...... of diffusive motion, is ecologically plausible, and provides an alternative mechanism for formation of patterns in spatially explicit ecosystem models, with emphasis on non-stationary spatio-temporal dynamics....

Development of ATC Tower Systems: Electronic Flight Strip System at LKPR and the Implementation of TAXI Milestone to SUM

Directory of Open Access Journals (Sweden)

Pavel Černý

2016-10-01

Full Text Available This article describes the Electronic Flight Strip System used at Václav Havel Airport Prague and presents the results of an analysis of the clearance input from ATCOs. The outcomes indicate that various clearances are frequently issued together in a common time frame, usually depending on the traffic flow structure. The focus then moves towards the implementation of the TAXI milestone into the Start-Up Manager. The used statistic methods indicate that the amount of TTOT recalculations after AOBT decreases, but not significantly. However, the accuracy of TTOT after TAXI clearance is considerably better. The mean and most common deviation of ATOT from TTOT after the implementation of TAXI milestone is -1 minute. The results are challenged and confirmed by a further analysis of the TTOT-ATOT difference regarding individual stand/RWY pairs. The results may be used to adjust the assumed taxi times.

Feather damaging behaviour in parrots: A review with consideration of comparative aspects

DEFF Research Database (Denmark)

Van Zeeland, Yvonne R A; Spruit, Berry M; Rodenburg, T Bas

2009-01-01

similarities with behavioural disorders present in other bird species. Feather pecking (FP) in poultry is of particular interest in this case. Because of the major impacts on welfare and economy, the disorder has been thoroughly investigated. It has been shown that genetic, socio-environmental...... and neurobiological factors all play a role in FP. Several theories have been postulated about the different motivational systems that affect the behaviour, of which (redirected) foraging appears to be the most generally accepted. FDB may result from similar motivations and underlying mechanisms, but has also been......Feather damaging behaviour (also referred to as feather picking or feather plucking) is a behavioural disorder that is frequently encountered in captive parrots. This disorder has many characteristics that are similar to trichotillomania, an impulse control disorder in humans. Unfortunately...

Labeling Residential Community Characteristics from Collective Activity Patterns Using Taxi Trip Data

Science.gov (United States)

Zhou, Y.; Fang, Z.

2017-09-01

There existing a significant social and spatial differentiation in the residential communities in urban city. People live in different places have different socioeconomic background, resulting in various geographically activity patterns. This paper aims to label the characteristics of residential communities in a city using collective activity patterns derived from taxi trip data. Specifically, we first present a method to allocate the O/D (Origin/Destination) points of taxi trips to the land use parcels where the activities taken place in. Then several indices are employed to describe the collective activity patterns, including both activity intensity, travel distance, travel time, and activity space of residents by taking account of the geographical distribution of all O/Ds of the taxi trip related to that residential community. Followed by that, an agglomerative hierarchical clustering algorithm is introduced to cluster the residential communities with similar activity patterns. In the case study of Wuhan, the residential communities are clearly divided into eight clusters, which could be labelled as ordinary communities, privileged communities, old isolated communities, suburban communities, and so on. In this paper, we provide a new perspective to label the land use under same type from people's mobility patterns with the support of big trajectory data.

Fuel Consumption and Emissions from Airport Taxi Operations

Science.gov (United States)

Jung, Yoon

2010-01-01

Developed a method to calculate fuel consumption and emissions of phases of taxi operations. Results at DFW showed that up to 18% of fuel can be saved by eliminating stop-and-go situations. Developed an energy efficient and environmentally friendly surface concept: Spot and Runway Departure Advisory (SARDA) tool. The SARDA tool has been identified as a potential candidate for a technology transfer to the FAA.

Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling.

Science.gov (United States)

Wilts, Bodo D; Michielsen, Kristel; De Raedt, Hans; Stavenga, Doekele G

2014-03-25

Birds-of-paradise are nature's prime examples of the evolution of color by sexual selection. Their brilliant, structurally colored feathers play a principal role in mating displays. The structural coloration of both the occipital and breast feathers of the bird-of-paradise Lawes' parotia is produced by melanin rodlets arranged in layers, together acting as interference reflectors. Light reflection by the silvery colored occipital feathers is unidirectional as in a classical multilayer, but the reflection by the richly colored breast feathers is three-directional and extraordinarily complex. Here we show that the reflection properties of both feather types can be quantitatively explained by finite-difference time-domain modeling using realistic feather anatomies and experimentally determined refractive index dispersion values of keratin and melanin. The results elucidate the interplay between avian coloration and vision and indicate tuning of the mating displays to the spectral properties of the avian visual system.

Evaluating cleansing effects on trace elements and stable isotope values in feathers of oiled birds.

Science.gov (United States)

Valladares, Sonia; Moreno, Roćio; Jover, Lluis; Sanpera, Carola

2010-01-01

Feathers of seabirds are widely used as a nondestructive tissue for pollution monitoring of trace elements, as well as convenient samples for trophic ecology studies by means of stable isotope analysis (SIA). Nevertheless, feathers can be occasionally impregnated with oil from deliberate ship discharges and from massive oil spill accidents. The feather structure makes them effective traps for particles and are subject to external contamination. It is unknown to what extent the oil adhered to feathers can change trace element concentrations or stable isotope signatures. This study has two primary objectives: (1) to assess if there are differences between trace element concentrations and stable isotope signatures of oiled and clean feathers, and (2) to determine if the cleansing of oiled feathers using commonly applied techniques such as sodium hydroxide (NaOH) washes in combination with an organic solvent (hexane) is more effective than using NaOH alone. In order to do this, we analysed trace elements (Se, Hg, Pb, Cu and Zn) and stable isotopes (delta(13)C and delta(15)N) of individual feathers of yellow-legged gulls (Larus michahellis) which were affected by the 2002 Prestige oil spill in Galicia (NW Spain). Two sets of feathers were analysed, one group were oil-free (Control group) and the other had oil adhered to its surface (Oiled group). We expected to find differences between control and oiled feathers when cleaning exclusively with NaOH and no differences when using hexane. Our results did not show significant differences between Control and Oiled groups as a consequence of the cleansing method used. Unexpectedly, the additional cleansing with hexane resulted in decreasing selenium concentrations and increasing zinc and delta(15)N values in all groups of feathers.

The dinosaurian origin of feathers: perspectives from dolphin (Cetacea) collagen fibers.

Science.gov (United States)

Lingham-Soliar, Theagarten

2003-12-01

The early origin of birds is a hotly disputed debate and may be broadly framed as a conflict between paleontologists and ornithologists. The paleontological emphasis has shifted from Archaeopteryx and its origins to recent finds of Cretaceous birds and "feathered" dinosaurs from China. The identification of alleged feathers has, however, relied principally on the visual image. Some workers have interpreted these integumentary structures as collagen fibers. To test the latter hypothesis, using light microscopy, collagen from the hypodermis (blubber) and subdermal connective tissue sheath was examined from a dolphin that had been buried for a year as part of an experiment. Within the blubber, toward the central thicker parts of the material, the collagen fibers had compacted and the three-dimensional latticework of normal blubber had more or less collapsed. Chromatographic analysis of the blubber revealed pronounced oxidation of the unsaturated lipids, probably accounting for the collapse of the latticework. Fibers normally bound together in bundles became separated into individual fibers or smaller bundles by degradation of the glue-like substance binding them together. These degraded collagen fibers show, in many instances, feather-like patterns, strikingly reminiscent of many of those identified as either "protofeathers" or "modern" feathers in dromaeosaurid dinosaurs. The findings throw serious doubt on the virtually complete reliance on visual image by supporters of the feathered dinosaur thesis and emphasize the need for more rigorous methods of identification using modern feathers as a frame of reference. Since collagen is the main fiber type found in most supporting tissues, the results have wide implications regarding the degradation and fossilization of vertebrate integument, such as that of the ichthyosaurs, dinosaurs and birds.

Viscoelastic Characterization of Long-Eared Owl Flight Feather Shaft and the Damping Ability Analysis

Directory of Open Access Journals (Sweden)

Jia-li Gao

2014-01-01

Full Text Available Flight feather shaft of long-eared owl is characterized by a three-parameter model for linear viscoelastic solids to reveal its damping ability. Uniaxial tensile tests of the long-eared owl, pigeon, and golden eagle flight feather shaft specimens were carried out based on Instron 3345 single column material testing system, respectively, and viscoelastic response of their stress and strain was described by the standard linear solid model. Parameter fitting result obtained from the tensile tests shows that there is no significant difference in instantaneous elastic modulus for the three birds’ feather shafts, but the owl shaft has the highest viscosity, implying more obvious viscoelastic performance. Dynamic mechanical property was characterized based on the tensile testing results. Loss factor (tanδ of the owl flight feather shaft was calculated to be 1.609 ± 0.238, far greater than those of the pigeon (0.896 ± 0.082 and golden eagle (1.087 ± 0.074. It is concluded that the long-eared owl flight feather has more outstanding damping ability compared to the pigeon and golden eagle flight feather shaft. Consequently, the long-eared owl flight feathers can dissipate the vibration energy more effectively during the flying process based on the principle of damping mechanism, for the purpose of vibration attenuation and structure radiated noise reduction.

Preparation and characterization of sponge film made from feathers

Energy Technology Data Exchange (ETDEWEB)

Zhuang, Yuan; Wu, Xiaoqian [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China); Cao, Zhangjun [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Zhao, Xiaoxiang; Zhou, Meihua [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China); Gao, Pin, E-mail: gaopin@mail.dhu.edu.cn [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China)

2013-12-01

Feather wastes generated from poultry farms will pose a problem for disposal, but they are sustainable resources of keratin. Reduction is one of the commonly used methods to obtain soluble keratin from feather. However, the residues generated during feather reduction reaction were rarely investigated. In this study, the residues were transformed into a porous and flexible sponge film by freeze-drying without pretreatment or addition of cross-linking agents. Glycerol was used to alter the physical and chemical characteristics of the sponge film. The film was characterized with a fiber strong stretch instrument, a Fourier transform infrared spectrophotometer, scanning electron microscopy, an elemental analyzer, a differential scanning calorimeter and an automatic air permeability apparatus. Tensile strength and melting point of the sponge film with the optimum glycerol content were 6.2 MPa and 170 °C respectively. Due to air permeability of 368 mm/s, the film can potentially be used in medicine, biology, textile, environmental technology, and so on. It is ecologically friendly and will produce additional benefits from the renewable materials. The film was utilized as adsorbents to remove Cr(VI) from aqueous solutions and as a filtering material for air pollution. Its maximum Cr(VI) uptake capacity was about 148.8 mg/g and the removal rate of PM{sub 10} was 98.3%. - Graphical abstract: The reduction residues were made into a smooth, elastic, porous and flexible sponge film through freeze drying, no pretreatment and no cross-linking agent added. - Highlights: • The residue from feather waste reduction was turned into a sponge film. • A glycerol content of 5% produced a sponge with the optimum characteristics. • The sponge was uniform, stable up to 160 °C, and had an air permeability of 368 mm/s. • Feather-derived sponge film has potential applications in medicine and technology.

Preparation and characterization of sponge film made from feathers

International Nuclear Information System (INIS)

Zhuang, Yuan; Wu, Xiaoqian; Cao, Zhangjun; Zhao, Xiaoxiang; Zhou, Meihua; Gao, Pin

2013-01-01

Feather wastes generated from poultry farms will pose a problem for disposal, but they are sustainable resources of keratin. Reduction is one of the commonly used methods to obtain soluble keratin from feather. However, the residues generated during feather reduction reaction were rarely investigated. In this study, the residues were transformed into a porous and flexible sponge film by freeze-drying without pretreatment or addition of cross-linking agents. Glycerol was used to alter the physical and chemical characteristics of the sponge film. The film was characterized with a fiber strong stretch instrument, a Fourier transform infrared spectrophotometer, scanning electron microscopy, an elemental analyzer, a differential scanning calorimeter and an automatic air permeability apparatus. Tensile strength and melting point of the sponge film with the optimum glycerol content were 6.2 MPa and 170 °C respectively. Due to air permeability of 368 mm/s, the film can potentially be used in medicine, biology, textile, environmental technology, and so on. It is ecologically friendly and will produce additional benefits from the renewable materials. The film was utilized as adsorbents to remove Cr(VI) from aqueous solutions and as a filtering material for air pollution. Its maximum Cr(VI) uptake capacity was about 148.8 mg/g and the removal rate of PM 10 was 98.3%. - Graphical abstract: The reduction residues were made into a smooth, elastic, porous and flexible sponge film through freeze drying, no pretreatment and no cross-linking agent added. - Highlights: • The residue from feather waste reduction was turned into a sponge film. • A glycerol content of 5% produced a sponge with the optimum characteristics. • The sponge was uniform, stable up to 160 °C, and had an air permeability of 368 mm/s. • Feather-derived sponge film has potential applications in medicine and technology

The share-a-ride problem : people and parcels sharing taxis

NARCIS (Netherlands)

Li, B.; Krushynskyi, D.; Reijers, H.A.; van Woensel, T.

2014-01-01

New city logistics approaches are needed to ensure efficient urban mobility for both people and goods. Usually, these are handled independently in dedicated networks. This paper considers conceptual and mathematical models in which people and parcels are handled in an integrated way by the same taxi

Module-based complexity formation: periodic patterning in feathers and hairs.

Science.gov (United States)

Chuong, Cheng-Ming; Yeh, Chao-Yuan; Jiang, Ting-Xin; Widelitz, Randall

2013-01-01

Patterns describe order which emerges from homogeneity. Complex patterns on the integument are striking because of their visibility throughout an organism’s lifespan. Periodic patterning is an effective design because the ensemble of hair or feather follicles (modules) allows the generation of complexity, including regional variations and cyclic regeneration, giving the skin appendages a new lease on life. Spatial patterns include the arrangements of feathers and hairs in specific number, size, and spacing.We explorehowa field of equivalent progenitor cells can generate periodically arranged modules based on genetic information, physical–chemical rules and developmental timing. Reconstitution experiments suggest a competitive equilibrium regulated by activators/inhibitors involving Turing reaction-diffusion. Temporal patterns result from oscillating stem cell activities within each module (microenvironment regulation), reflected as growth (anagen) and resting (telogen) phases during the cycling of feather and hair follicles. Stimulating modules with activators initiates the spread of regenerative hair waves, while global inhibitors outside each module (macroenvironment) prevent this. Different wave patterns can be simulated by cellular automata principles. Hormonal status and seasonal changes can modulate appendage phenotypes, leading to ‘organ metamorphosis’, with multiple ectodermal organ phenotypes generated from the same precursors. We discuss potential novel evolutionary steps using this module-based complexity in several amniote integument organs, exemplified by the spectacular peacock feather pattern. We thus explore the application of the acquired knowledge of patterning in tissue engineering. New hair follicles can be generated after wounding. Hairs and feathers can be reconstituted through self-organization of dissociated progenitor cells. © 2012 Wiley Periodicals, Inc.

Exposure of bus and taxi drivers to urban air pollutants as measured by DNA and protein adducts

DEFF Research Database (Denmark)

Hemminki, K.; Zhang, L.F.; Krüger, J.

1994-01-01

Urinary 1-hydroxypyrene, lymphocyte DNA adducts, serum protein-bound PAH and hemoglobin-bound alkene adducts were analysed from 4 groups of non-smoking men: urban and suburban bus drivers, taxi drivers and suburban controls. The only differences between the groups were in DNA adducts between...... suburban bus drivers and controls, and in DNA adduct and plasma protein PAH-adducts between taxi drivers and controls....

A comparison of mercury levels in feathers and eggs of osprey (Pandion haliaetus) in the North American Great Lakes.

Science.gov (United States)

Hughes, K D; Ewins, P J; Clark, K E

1997-11-01

Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three "naturally formed" lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991-1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28-35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects.

The performance of broiler finisher birds fed varying levels of feather ...

African Journals Online (AJOL)

The performance of broiler finisher birds fed varying levels of feather meal as replacement for soya bean meal. ... meal increased, feed cost/ kg weight gain increased and both differed significantly (P<0.05) between treatment means, while the birds tolerated feather meal up to 7.5% inclusion level, 2.5% was the optimal.

Modeling with Robotran the autonomous electrical taxi and pushback operations of an Airbus A320

OpenAIRE

Quinet, Stéphane

2017-01-01

Nowadays, commercial flights are very close to a full automation while several means of transport already made the move. Civilian transport airplanes offer the possibility to fly in a fully automated mode from a few seconds after take-off to the exit of the runway - down to 60 knots- after landing. However, three flight sequences are not covered yet by an automated solution : the take-off, the taxi and the pushback. This work is a global approach of an autonomous taxi and pushback system impl...

Spatially modulated structural colour in bird feathers

Science.gov (United States)

Parnell, Andrew J.; Washington, Adam L.; Mykhaylyk, Oleksandr O.; Hill, Christopher J.; Bianco, Antonino; Burg, Stephanie L.; Dennison, Andrew J. C.; Snape, Mary; Cadby, Ashley J.; Smith, Andrew; Prevost, Sylvain; Whittaker, David M.; Jones, Richard A. L.; Fairclough, J. Patrick. A.; Parker, Andrew R.

2015-12-01

Eurasian Jay (Garrulus glandarius) feathers display periodic variations in the reflected colour from white through light blue, dark blue and black. We find the structures responsible for the colour are continuous in their size and spatially controlled by the degree of spinodal phase separation in the corresponding region of the feather barb. Blue structures have a well-defined broadband ultra-violet (UV) to blue wavelength distribution; the corresponding nanostructure has characteristic spinodal morphology with a lengthscale of order 150 nm. White regions have a larger 200 nm nanostructure, consistent with a spinodal process that has coarsened further, yielding broader wavelength white reflectance. Our analysis shows that nanostructure in single bird feather barbs can be varied continuously by controlling the time the keratin network is allowed to phase separate before mobility in the system is arrested. Dynamic scaling analysis of the single barb scattering data implies that the phase separation arrest mechanism is rapid and also distinct from the spinodal phase separation mechanism i.e. it is not gelation or intermolecular re-association. Any growing lengthscale using this spinodal phase separation approach must first traverse the UV and blue wavelength regions, growing the structure by coarsening, resulting in a broad distribution of domain sizes.

Spatially modulated structural colour in bird feathers.

Science.gov (United States)

Parnell, Andrew J; Washington, Adam L; Mykhaylyk, Oleksandr O; Hill, Christopher J; Bianco, Antonino; Burg, Stephanie L; Dennison, Andrew J C; Snape, Mary; Cadby, Ashley J; Smith, Andrew; Prevost, Sylvain; Whittaker, David M; Jones, Richard A L; Fairclough, J Patrick A; Parker, Andrew R

2015-12-21

Eurasian Jay (Garrulus glandarius) feathers display periodic variations in the reflected colour from white through light blue, dark blue and black. We find the structures responsible for the colour are continuous in their size and spatially controlled by the degree of spinodal phase separation in the corresponding region of the feather barb. Blue structures have a well-defined broadband ultra-violet (UV) to blue wavelength distribution; the corresponding nanostructure has characteristic spinodal morphology with a lengthscale of order 150 nm. White regions have a larger 200 nm nanostructure, consistent with a spinodal process that has coarsened further, yielding broader wavelength white reflectance. Our analysis shows that nanostructure in single bird feather barbs can be varied continuously by controlling the time the keratin network is allowed to phase separate before mobility in the system is arrested. Dynamic scaling analysis of the single barb scattering data implies that the phase separation arrest mechanism is rapid and also distinct from the spinodal phase separation mechanism i.e. it is not gelation or intermolecular re-association. Any growing lengthscale using this spinodal phase separation approach must first traverse the UV and blue wavelength regions, growing the structure by coarsening, resulting in a broad distribution of domain sizes.

77 FR 12493 - Revisions to the California State Implementation Plan, Feather River Air Quality Management District

Science.gov (United States)

2012-03-01

... the California State Implementation Plan, Feather River Air Quality Management District AGENCY... limited disapproval of revisions to the Feather River Air Quality Management District (FRAQMD) portion of.... * * * * * (c) * * * (378) * * * (i) * * * (E) Feather River Air Quality Management District. (1) Rule 3.22...

Trade in Andean Condor Vulture gryphus feathers and body parts in ...

African Journals Online (AJOL)

body parts in the city of Cusco and the Sacred Valley,. Cusco region, Peru. Robert S. R. ... The sale of Andean Condor feathers and body parts is undertaken openly in the tourist markets of Cusco and the Sacred .... and shops. Prices in local currency – Nuevo Sol and US Dollar equivalent given in parentheses). Feather.

Turing-Hopf bifurcations in a predator-prey model with herd behavior, quadratic mortality and prey-taxis

Science.gov (United States)

Liu, Xia; Zhang, Tonghua; Meng, Xinzhu; Zhang, Tongqian

2018-04-01

In this paper, we propose a predator-prey model with herd behavior and prey-taxis. Then, we analyze the stability and bifurcation of the positive equilibrium of the model subject to the homogeneous Neumann boundary condition. By using an abstract bifurcation theory and taking prey-tactic sensitivity coefficient as the bifurcation parameter, we obtain a branch of stable nonconstant solutions bifurcating from the positive equilibrium. Our results show that prey-taxis can yield the occurrence of spatial patterns.

Economic Analysis on Value Chain of Taxi Fleet with Battery-Swapping Mode Using Multiobjective Genetic Algorithm

Directory of Open Access Journals (Sweden)

Guobao Ning

2012-01-01

Full Text Available This paper presents an economic analysis model on value chain of taxi fleet with battery-swapping mode in a pilot city. In the model, economic benefits of charging-swapping station group, taxi company, and taxi driver in the region have been taken into consideration. Thus, the model is a multiobjective function and multiobjective genetic algorithm is used to solve this problem. According to the real data collected from the pilot city, the multiobjective genetic algorithm is tested as an effective method to solve this problem. Furthermore, the effects of price of electricity, price of battery package, life cycle of battery package, cost of battery-swapping devices and infrastructure, and driving mileage per day on the benefits of value holders are analyzed, which provide theoretical and practical reference for the deployment of electric vehicles, for the national subsidy criteria adjusment, technological innovation instruction, commercial mode selection, and infrastructure construction.

parasitised feathered dinosaurs as revealed by Cretaceous amber assemblages.

Science.gov (United States)

Peñalver, Enrique; Arillo, Antonio; Delclòs, Xavier; Peris, David; Grimaldi, David A; Anderson, Scott R; Nascimbene, Paul C; Pérez-de la Fuente, Ricardo

2017-12-12

Ticks are currently among the most prevalent blood-feeding ectoparasites, but their feeding habits and hosts in deep time have long remained speculative. Here, we report direct and indirect evidence in 99 million-year-old Cretaceous amber showing that hard ticks and ticks of the extinct new family Deinocrotonidae fed on blood from feathered dinosaurs, non-avialan or avialan excluding crown-group birds. A †Cornupalpatum burmanicum hard tick is entangled in a pennaceous feather. Two deinocrotonids described as †Deinocroton draculi gen. et sp. nov. have specialised setae from dermestid beetle larvae (hastisetae) attached to their bodies, likely indicating cohabitation in a feathered dinosaur nest. A third conspecific specimen is blood-engorged, its anatomical features suggesting that deinocrotonids fed rapidly to engorgement and had multiple gonotrophic cycles. These findings provide insight into early tick evolution and ecology, and shed light on poorly known arthropod-vertebrate interactions and potential disease transmission during the Mesozoic.

Visual exploration of big spatio-temporal urban data: a study of New York City taxi trips.

Science.gov (United States)

Ferreira, Nivan; Poco, Jorge; Vo, Huy T; Freire, Juliana; Silva, Cláudio T

2013-12-01

As increasing volumes of urban data are captured and become available, new opportunities arise for data-driven analysis that can lead to improvements in the lives of citizens through evidence-based decision making and policies. In this paper, we focus on a particularly important urban data set: taxi trips. Taxis are valuable sensors and information associated with taxi trips can provide unprecedented insight into many different aspects of city life, from economic activity and human behavior to mobility patterns. But analyzing these data presents many challenges. The data are complex, containing geographical and temporal components in addition to multiple variables associated with each trip. Consequently, it is hard to specify exploratory queries and to perform comparative analyses (e.g., compare different regions over time). This problem is compounded due to the size of the data-there are on average 500,000 taxi trips each day in NYC. We propose a new model that allows users to visually query taxi trips. Besides standard analytics queries, the model supports origin-destination queries that enable the study of mobility across the city. We show that this model is able to express a wide range of spatio-temporal queries, and it is also flexible in that not only can queries be composed but also different aggregations and visual representations can be applied, allowing users to explore and compare results. We have built a scalable system that implements this model which supports interactive response times; makes use of an adaptive level-of-detail rendering strategy to generate clutter-free visualization for large results; and shows hidden details to the users in a summary through the use of overlay heat maps. We present a series of case studies motivated by traffic engineers and economists that show how our model and system enable domain experts to perform tasks that were previously unattainable for them.

THE ENERGETIC COST OF FEATHER SYNTHESIS IS PROPORTIONAL TO BASAL METABOLIC-RATE

NARCIS (Netherlands)

VISSER, GH; DAAN, S

1993-01-01

The cost of feather production, C(f) (kJ . [g dry feathers]-1), differs substantially between species. We studied the molt cost in one insectivorous songbird (bluethroat, Luscinia s. svecica) and one granivorous songbird (common redpoll, Carduelis f. flammea), We wanted to test whether differences

A Geo-Aware Taxi Carrying Management System by Using Location Based Services and Zone Queuing Techniques on Internet of Things

Directory of Open Access Journals (Sweden)

Chyi-Ren Dow

2016-01-01

Full Text Available Taxi plays a crucial role in the transportation system because of the characteristic that can be hailed conveniently. Most of the taxi drivers obtain passengers by hunting on the road or waiting in a fixed taxi queuing point; however these methods have poor performance, high vacancy rate, and several critical problems such as air pollution and foul up traffic. This study proposed a taxi carrying management system by using location based services and zone queuing techniques on Internet of things. The proposed system allows drivers to both hunt on the road and wait in a queuing zone. A queuing table is used in the control center and neighbor tables are used in RSUs for zone queuing establishment. Joining and leaving mechanisms are developed for zone queuing management. To enhance service efficiency and quality, we present a scheme to prevent the ping-pong effect which is based on the location based services, a hunting rate calculation scheme, and a path planning service for taxi drivers according to the history carrying record. PRISM is used to simulate the proposed system, and the results indicated that our scheme outperforms the waiting and hunting models in terms of number of customers, vacancy rate, and profit.

Video event data recording of a taxi driver used for diagnosis of epilepsy

Directory of Open Access Journals (Sweden)

Kotaro Sakurai

2014-01-01

Full Text Available A video event data recorder (VEDR in a motor vehicle records images before and after a traffic accident. This report describes a taxi driver whose seizures were recorded by VEDR, which was extremely useful for the diagnosis of epilepsy. The patient was a 63-year-old right-handed Japanese male taxi driver. He collided with a streetlight. Two years prior to this incident, he raced an engine for a long time while parked. The VEDR enabled confirmation that the accidents depended on an epileptic seizure and he was diagnosed with symptomatic localization-related epilepsy. The VEDR is useful not only for traffic accident evidence; it might also contribute to a driver's health care and road safety.

The chicken frizzle feather is due to an α-keratin (KRT75 mutation that causes a defective rachis.

Directory of Open Access Journals (Sweden)

Chen Siang Ng

Full Text Available Feathers have complex forms and are an excellent model to study the development and evolution of morphologies. Existing chicken feather mutants are especially useful for identifying genetic determinants of feather formation. This study focused on the gene F, underlying the frizzle feather trait that has a characteristic curled feather rachis and barbs in domestic chickens. Our developmental biology studies identified defects in feather medulla formation, and physical studies revealed that the frizzle feather curls in a stepwise manner. The frizzle gene is transmitted in an autosomal incomplete dominant mode. A whole-genome linkage scan of five pedigrees with 2678 SNPs revealed association of the frizzle locus with a keratin gene-enriched region within the linkage group E22C19W28_E50C23. Sequence analyses of the keratin gene cluster identified a 69 bp in-frame deletion in a conserved region of KRT75, an α-keratin gene. Retroviral-mediated expression of the mutated F cDNA in the wild-type rectrix qualitatively changed the bending of the rachis with some features of frizzle feathers including irregular kinks, severe bending near their distal ends, and substantially higher variations among samples in comparison to normal feathers. These results confirmed KRT75 as the F gene. This study demonstrates the potential of our approach for identifying genetic determinants of feather forms.

k{sub 0}-INAA for determining chemical elements in bird feathers

Energy Technology Data Exchange (ETDEWEB)

Franca, Elvis J., E-mail: ejfranca@usp.b [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil); Fernandes, Elisabete A.N.; Fonseca, Felipe Y. [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil); Antunes, Alexsander Z. [IF, Instituto Florestal do Estado de Sao Paulo, Rua do Horto 931, Horto Florestal 02377-000, Sao Paulo, SP (Brazil); Bardini Junior, Claudiney; Bacchi, Marcio A.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O. [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil)

2010-10-11

The k{sub 0}-method instrumental neutron activation analysis (k{sub 0}-INAA) was employed for determining chemical elements in bird feathers. A collection was obtained taking into account several bird species from wet ecosystems in diverse regions of Brazil. For comparison reason, feathers were actively sampled in a riparian forest from the Marins Stream, Piracicaba, Sao Paulo State, using mist nets specific for capturing birds. Biological certified reference materials were used for assessing the quality of analytical procedure. Quantification of chemical elements was performed using the k{sub 0}-INAA Quantu Software. Sixteen chemical elements, including macro and micronutrients, and trace elements, have been quantified in feathers, in which analytical uncertainties varied from 2% to 40% depending on the chemical element mass fraction. Results indicated high mass fractions of Br (max=7.9 mg kg{sup -1}), Co (max=0.47 mg kg{sup -1}), Cr (max=68 mg kg{sup -1}), Hg (max=2.79 mg kg{sup -1}), Sb (max=0.20 mg kg{sup -1}), Se (max=1.3 mg kg{sup -1}) and Zn (max=192 mg kg{sup -1}) in bird feathers, probably associated with the degree of pollution of the areas evaluated. In order to corroborate the use of k{sub 0}-INAA results in biomonitoring studies using avian community, different factor analysis methods were used to check chemical element source apportionment and locality clustering based on feather chemical composition.

Health status, job stress and work-related injury among Los Angeles taxi drivers.

Science.gov (United States)

Wang, Pin-Chieh; Delp, Linda

2014-01-01

Taxi drivers work long hours for low wages and report hypertension, weight gain, and musculoskeletal pain associated with the sedentary nature of their job, stressful working conditions, and poor dietary habits. They also experience a high work-related fatality rate. The objective of this study is to examine the association of taxi drivers' health status and level of job stress with work-related injury and determine if a potential interaction exists. A survey of 309 Los Angeles taxi drivers provides basic data on health status, job stress, and work-related injuries. We further analyzed the data using a Modified Poisson regression approach with a robust error variance to estimate the relative risk (RR) and the 95% confidence intervals (CI) of work-related injuries. Focus group results supplemented and helped interpret the quantitative data. The joint effect of good health and low job stress was associated with a large reduction in the incidence of injuries, consistent with the hypothesis that health status and stress levels modify each other on the risk of work-related injury. These results suggest that the combination of stress reduction and health management programs together with changes in the stressful conditions of the job may provide targeted avenues to prevent injuries.

A two-dimensional iterative panel method and boundary layer model for bio-inspired multi-body wings

Science.gov (United States)

Blower, Christopher J.; Dhruv, Akash; Wickenheiser, Adam M.

2014-03-01

The increased use of Unmanned Aerial Vehicles (UAVs) has created a continuous demand for improved flight capabilities and range of use. During the last decade, engineers have turned to bio-inspiration for new and innovative flow control methods for gust alleviation, maneuverability, and stability improvement using morphing aircraft wings. The bio-inspired wing design considered in this study mimics the flow manipulation techniques performed by birds to extend the operating envelope of UAVs through the installation of an array of feather-like panels across the airfoil's upper and lower surfaces while replacing the trailing edge flap. Each flap has the ability to deflect into both the airfoil and the inbound airflow using hinge points with a single degree-of-freedom, situated at 20%, 40%, 60% and 80% of the chord. The installation of the surface flaps offers configurations that enable advantageous maneuvers while alleviating gust disturbances. Due to the number of possible permutations available for the flap configurations, an iterative constant-strength doublet/source panel method has been developed with an integrated boundary layer model to calculate the pressure distribution and viscous drag over the wing's surface. As a result, the lift, drag and moment coefficients for each airfoil configuration can be calculated. The flight coefficients of this numerical method are validated using experimental data from a low speed suction wind tunnel operating at a Reynolds Number 300,000. This method enables the aerodynamic assessment of a morphing wing profile to be performed accurately and efficiently in comparison to Computational Fluid Dynamics methods and experiments as discussed herein.

Determination of Cr and Cd concentration adsorbed by chicken feathers

International Nuclear Information System (INIS)

Lopez M, A.; Cuapio O, L.A.; Cardenas P, S.; Balcazar, M.; Jauregui, V.; Bonilla P, A.

2008-01-01

In this work the results of the samples analysis of chicken feathers are presented, used as adsorber of the heavy metals Cd and Cr present in water solutions with well-known concentrations of these metals. It was used the Neutron Activation Analysis technique (AAN), using the TRIGA Mark-III reactor of the Nuclear Center of Mexico. The obtained results they show the advantages of having a versatile installation for the analysis of this type of samples. By means of the analysis of the results, it was determined the feasibility of using chicken feathers like adsorber of these metals present in polluted waters, additionally, it was detected the presence of others polluting elements in the inputs to prepare the reference solutions as well as in the processes, so much of preparation of the feathers like of the metals adsorption. (Author)

Fully Biodegradable Biocomposites with High Chicken Feather Content

Directory of Open Access Journals (Sweden)

Ibon Aranberri

2017-11-01

Full Text Available The aim of this work was to develop new biodegradable polymeric materials with high loadings of chicken feather (CF. In this study, the effect of CF concentration and the type of biodegradable matrix on the physical, mechanical and thermal properties of the biocomposites was investigated. The selected biopolymers were polylactic acid (PLA, polybutyrate adipate terephthalate (PBAT and a PLA/thermoplastic copolyester blend. The studied biocomposites were manufactured with a torque rheometer having a CF content of 50 and 60 wt %. Due to the low tensile strength of CFs, the resulting materials were penalized in terms of mechanical properties. However, high-loading CF biocomposites resulted in lightweight and thermal-insulating materials when compared with neat bioplastics. Additionally, the adhesion between CFs and the PLA matrix was also investigated and a significant improvement of the wettability of the feathers was obtained with the alkali treatment of the CFs and the addition of a plasticizer like polyethylene glycol (PEG. Considering all the properties, these 100% fully biodegradable biocomposites could be adequate for panel components, flooring or building materials as an alternative to wood–plastic composites, contributing to the valorisation of chicken feather waste as a renewable material.

Advanced slab polyurethane foam with feather touch; Soft feather urethane foam no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Yamada, Y; Ono, H [Toyota Motor Corp., Aichi (Japan); Mori, A; Yamaguchi, N; Nakamura, T [Bridgestone Corp., Tokyo (Japan)

1997-10-01

Automotive seat plays an important part, which are not only retention of sitting position, but also comfort and high-class feeling. Wadding, which is a part of the seat, is a key component for the sitting comfortableness. This paper is concerned with advanced slab polyurethane foam with feather touch feeling. The compounding of formation, foaming process and reliability of mass production is studied. 2 refs., 10 figs., 3 tabs.

A lightweight neighbor-info-based routing protocol for no-base-station taxi-call system.

Science.gov (United States)

Zhu, Xudong; Wang, Jinhang; Chen, Yunchao

2014-01-01

Since the quick topology change and short connection duration, the VANET has had unstable routing and wireless signal quality. This paper proposes a kind of lightweight routing protocol-LNIB for call system without base station, which is applicable to the urban taxis. LNIB maintains and predicts neighbor information dynamically, thus finding the reliable path between the source and the target. This paper describes the protocol in detail and evaluates the performance of this protocol by simulating under different nodes density and speed. The result of evaluation shows that the performance of LNIB is better than AODV which is a classic protocol in taxi-call scene.

Pronounced variation in tarsal and foot feathering in the upland buzzard (Buteo hemilasius) in Mongolia

Science.gov (United States)

Ellis, D.H.; Woffinden, N.; Whitlock, P.L.; Tsengeg, Pu

1999-01-01

During 1994, 1995, 1997, and 1998 expeditions across Mongolia, we located over 250 upland buzzard (Buteo hemilasius) nests. At these, we noted considerable morphological variation in plumage coloration and in leg pterylosis. In 1997 and 1998, we examined 131 nests scattered across eastern and central Mongolia and report here the tarsal condition of 119 nestlings from 59 broods where young were at least 2 weeks of age. Of 119 birds carefully examined, 50 (42%) had less than fully feathered tarsi and 4 of the 69 with fully feathered tarsi had scattered feathers on their toes. Thus, 54 of 119 birds (45%) in some way deviated from the feathered tarsibare toes condition. This extraordinary degree of variability in feather patterns may be best explained as the result of extensive and relatively recent hybridization between the longlegged (Buteo rufinus) and roughlegged (B. lagopus) buzzards and/or between long-legged and upland buzzards.

Determination of the viability of chicken feather as oil spill clean-up ...

African Journals Online (AJOL)

In this study a comparative assessment was conducted between chicken feather and a conventional synthetic sorbent mat used in the oil industry to clean-up oil spill. The result of the study shows that chicken feather has higher oil sorption capacity and sorbed oil recoverability than the standard (synthetic sorbent mat), and ...

Aircrafts' taxi noise. Sound power level and directivity frequency band results

NARCIS (Netherlands)

Asensio, C.; Pavón, I.; Ruiz, M.; Pagan Munoz, Raul; Recuero, M.

2009-01-01

When noise mapping airports, the main noise sources are take offs and landings. But aircrafts' taxi noise can also be important, and should be considered, for instance when there are residential buildings near the airport's terminal. Main prediction tools, like Integrated Noise Model (INM), do not

Fault bars in bird feathers: mechanisms, and ecological and evolutionary causes and consequences.

Science.gov (United States)

Jovani, Roger; Rohwer, Sievert

2017-05-01

Fault bars are narrow malformations in feathers oriented almost perpendicular to the rachis where the feather vein and even the rachis may break. Breaks in the barbs and barbules result in small pieces of the feather vein being lost, while breaks in the rachis result in loss of the distal portion of the feather. Here, we provide a comprehensive review of 74 papers on fault bar formation in hopes of providing a clearer approach to their study. First, we review the evidence that the propensity to develop fault bars is modified by natural selection. Given that fault bars persist in the face of survival costs, we conclude that they must be an unfortunate consequence of some alternative adaptation that outweighs the fitness costs of fault bars. Second, we summarize evidence that the development of fault bars is triggered by psychological stress such as that of handling or predation attempts, and that they persist because the sudden contractions of the muscles in the feather follicle that control fright moults also causes the development of fault bars in growing feathers. Third, we review external and physiological (e.g. corticosterone) agents that may affect the likelihood that an acute stress will result in a growing feather exhibiting a fault bar. These modifying factors have often been treated as fundamental causes in the earlier literature on fault bars. Fourth, we then use this classification to propose a tentative model where fault bars of different severity (from light to severe) are the outcome of the interaction between the propensity to produce fault bars (which differs between species, individuals and feather follicles within individuals) and the intensity of the perturbation. This model helps to explain contradictory results in the literature, to identify gaps in our knowledge, and to suggest further studies. Lastly, we discuss ways in which better understanding of fault bars can inform us about other aspects of avian evolutionary ecology, such as the

Metals and trace elements in feathers: A geochemical approach to avoid misinterpretation of analytical responses.

Science.gov (United States)

Borghesi, Fabrizio; Migani, Francesca; Andreotti, Alessandro; Baccetti, Nicola; Bianchi, Nicola; Birke, Manfred; Dinelli, Enrico

2016-02-15

Assessing trace metal pollution using feathers has long attracted the attention of ecotoxicologists as a cost-effective and non-invasive biomonitoring method. In order to interpret the concentrations in feathers considering the external contamination due to lithic residue particles, we adopted a novel geochemical approach. We analysed 58 element concentrations in feathers of wild Eurasian Greater Flamingo Phoenicopterus roseus fledglings, from 4 colonies in Western Europe (Spain, France, Sardinia, and North-eastern Italy) and one group of adults from zoo. In addition, 53 elements were assessed in soil collected close to the nesting islets. This enabled to compare a wide selection of metals among the colonies, highlighting environmental anomalies and tackling possible causes of misinterpretation of feather results. Most trace elements in feathers (Al, Ce, Co, Cs, Fe, Ga, Li, Mn, Nb, Pb, Rb, Ti, V, Zr, and REEs) were of external origin. Some elements could be constitutive (Cu, Zn) or significantly bioaccumulated (Hg, Se) in flamingos. For As, Cr, and to a lesser extent Pb, it seems that bioaccumulation potentially could be revealed by highly exposed birds, provided feathers are well cleaned. This comprehensive study provides a new dataset and confirms that Hg has been accumulated in feathers in all sites to some extent, with particular concern for the Sardinian colony, which should be studied further including Cr. The Spanish colony appears critical for As pollution and should be urgently investigated in depth. Feathers collected from North-eastern Italy were the hardest to clean, but our methods allowed biological interpretation of Cr and Pb. Our study highlights the importance of external contamination when analysing trace elements in feathers and advances methodological recommendations in order to reduce the presence of residual particles carrying elements of external origin. Geochemical data, when available, can represent a valuable tool for a correct

Isotopic characterization of flight feathers in two pelagic seabirds: Sampling strategies for ecological studies

Science.gov (United States)

Wiley, Anne E.; Ostrom, Peggy H.; Stricker, Craig A.; James, Helen F.; Gandhi, Hasand

2010-01-01

We wish to use stable-isotope analysis of flight feathers to understand the feeding behavior of pelagic seabirds, such as the Hawaiian Petrel (Pterodroma sandwichensis) and Newell’s Shearwater (Puffinus auricularis newelli). Analysis of remiges is particularly informative because the sequence and timing of remex molt are often known. The initial step, reported here, is to obtain accurate isotope values from whole remiges by means of a minimally invasive protocol appropriate for live birds or museum specimens. The high variability observed in D13C and D15N values within a feather precludes the use of a small section of vane. We found the average range within 42 Hawaiian Petrel remiges to be 1.3‰ for both D13C and D15N and that within 10 Newell’s Shearwater remiges to be 1.3‰ and 0.7‰ for D13C and D15N, respectively. The D13C of all 52 feathers increased from tip to base, and the majority of Hawaiian Petrel feathers showed an analogous trend in D15N. Although the average range of DD in 21 Hawaiian Petrel remiges was 11‰, we found no longitudinal trend. We discuss influences of trophic level, foraging location, metabolism, and pigmentation on isotope values and compare three methods of obtaining isotope averages of whole feathers. Our novel barb-sampling protocol requires only 1.0 mg of feather and minimal preparation time. Because it leaves the feather nearly intact, this protocol will likely facilitate obtaining isotope values from remiges of live birds and museum specimens. As a consequence, it will help expand the understanding of historical trends in foraging behavior

Avian Wings

Science.gov (United States)

Liu, Tianshu; Kuykendoll, K.; Rhew, R.; Jones, S.

2004-01-01

This paper describes the avian wing geometry (Seagull, Merganser, Teal and Owl) extracted from non-contact surface measurements using a three-dimensional laser scanner. The geometric quantities, including the camber line and thickness distribution of airfoil, wing planform, chord distribution, and twist distribution, are given in convenient analytical expressions. Thus, the avian wing surfaces can be generated and the wing kinematics can be simulated. The aerodynamic characteristics of avian airfoils in steady inviscid flows are briefly discussed. The avian wing kinematics is recovered from videos of three level-flying birds (Crane, Seagull and Goose) based on a two-jointed arm model. A flapping seagull wing in the 3D physical space is re-constructed from the extracted wing geometry and kinematics.

Harmonic hopping, and both punctuated and gradual evolution of acoustic characters in Selasphorus hummingbird tail-feathers.

Directory of Open Access Journals (Sweden)

Christopher James Clark

Full Text Available Models of character evolution often assume a single mode of evolutionary change, such as continuous, or discrete. Here I provide an example in which a character exhibits both types of change. Hummingbirds in the genus Selasphorus produce sound with fluttering tail-feathers during courtship. The ancestral character state within Selasphorus is production of sound with an inner tail-feather, R2, in which the sound usually evolves gradually. Calliope and Allen's Hummingbirds have evolved autapomorphic acoustic mechanisms that involve feather-feather interactions. I develop a source-filter model of these interactions. The 'source' comprises feather(s that are both necessary and sufficient for sound production, and are aerodynamically coupled to neighboring feathers, which act as filters. Filters are unnecessary or insufficient for sound production, but may evolve to become sources. Allen's Hummingbird has evolved to produce sound with two sources, one with feather R3, another frequency-modulated sound with R4, and their interaction frequencies. Allen's R2 retains the ancestral character state, a ∼1 kHz "ghost" fundamental frequency masked by R3, which is revealed when R3 is experimentally removed. In the ancestor to Allen's Hummingbird, the dominant frequency has 'hopped' to the second harmonic without passing through intermediate frequencies. This demonstrates that although the fundamental frequency of a communication sound may usually evolve gradually, occasional jumps from one character state to another can occur in a discrete fashion. Accordingly, mapping acoustic characters on a phylogeny may produce misleading results if the physical mechanism of production is not known.

Proteomic analysis of enzyme production by Bacillus licheniformis using different feather wastes as the sole fermentation media.

Science.gov (United States)

Parrado, J; Rodriguez-Morgado, B; Tejada, M; Hernandez, T; Garcia, C

2014-04-10

This study evaluates the use of different types of feathers as fermentation media for enzyme production. Bacillus licheniformis was grown on the feathers, which lead to total biodegradation due to bacterial enzymatic hydrolytic excretion. B. licheniformis excretes protease and lipase activity, with feather concentration being the main parameter controlling their generation. Using a proteomic approach, the proteins excreted during fermentation were identified, and the influence of the chemical composition of the feathers on protein secretion was tested. The identified proteins are hydrolytic enzymes such as keratinase, gamma-glutamyltranspeptidase, chitosanases, and glicosidases. The diversity of proteins is related to the chemical complexity of the feathers. Understanding the composition of a hydrolytic system, when B. licheniformis is cultured on different feathers, may assist in utilizing such a system for producing different hydrolytic enzymes. The data indicate that proteomics can be a valuable tool for describing the physiological state of B. licheniformis cell populations growing on different wastes. Copyright © 2014 Elsevier Inc. All rights reserved.

Are melanized feather barbs stronger?

Science.gov (United States)

Butler, Michael; Johnson, Amy S

2004-01-01

Melanin has been associated with increased resistance to abrasion, decreased wear and lowered barb breakage in feathers. But, this association was inferred without considering barb position along the rachis as a potentially confounding variable. We examined the cross-sectional area, breaking force, breaking stress, breaking strain and toughness of melanized and unmelanized barbs along the entire rachis of a primary feather from an osprey (Pandion haliaetus). Although breaking force was higher for melanized barbs, breaking stress (force divided by cross-sectional area) was greater for unmelanized barbs. But when position was considered, all mechanical differences between melanized and unmelanized barbs disappeared. Barb breaking stress, breaking strain and toughness decreased, and breaking stiffness increased, distally along the rachis. These proximal-distal material property changes are small and seem unlikely to affect flight performance of barbs. Our observations of barb bending, breaking and morphology, however, lead us to propose a design principle for barbs. We propose that, by being thicker-walled dorso-ventrally, the barb's flexural stiffness is increased during flight; but, by allowing for twisting when loaded with dangerously high forces, barbs firstly avoid failure by bending and secondly avoid complete failure by buckling rather than rupturing.

Response of sheep fed on concentrate containing feather meal and supplemented with mineral Chromium

Directory of Open Access Journals (Sweden)

Yulistiani D

2013-03-01

Full Text Available A study was conducted to evaluate the effect of substitution of protein concentrate with feather meal supplemented with organic chromium mineral on performance of lambs. Twenty five male lambs were fed basal feed of fresh chopped king grass ad libitum and were allotted to either one of five different supplements (five dietary treatments: Control (C; 10% of protein in concentrate was substituted by feather meal (FM; 10% of protein in concentrate was substituted by feather meal supplemented with Cr yeast at 1.5 mg (FMCrOrg; 10% of protein in concentrate was substituted by feather meal supplemented with Cr inorganic which equal to the amount of Cr bound in yeast (FMCr; Concentrate control supplemented with 1.5 mg Cr yeast (CCrOrg. Cr-organic was synthesized by incorporating CrCl3 in fermented rice flour by Rhizopus sp. The mineral is mixed with feather meal as a mineral carrier. Sheep in all treatments received iso protein concentrate. Parameters observed were body weight change, feed consumption and nutrient digestibility. Results shows that there was no significant effect of diet treatments on average daily gain (ADG, dry matter consumption and feed conversion, with the average value of 75.4 gr/day; 74.9 g/BW0.75 and 9.9 respectively, However diet treatment of organic chromium and protein substitution with feather meal (FMCrOrg showed tendency of having higher ADG (83.57 g/h/d. Average nutrient digestibility of dry matter, organic matter and NDF were 68.7; 69.6 and 60.9%, respectively. However NDF digestibility of FMCrOrg tended to be higher than other treatment (67.0%. It is concluded that partial substitution of protein concentrate by feather meal and 1.5 mg Cr-organic supplementation did not affect sheep performance.

Adrenocortical reactivity and central serotonin and dopamine turnover in young chicks from a high and low feather-pecking line of laying hens

NARCIS (Netherlands)

van Hierden, YM; Korte, SM; Ruesink, EW; van Reenen, CG; Engel, B; Korte-Bouws, GAH; Koolhaas, JM; Blokhuis, HJ

2002-01-01

Feather pecking in domestic fowl is a behavioral abnormality that consists of mild or injurious pecking at feathers of conspecifics. Previously, it was shown that chicks from a high feather-pecking (HFP) and low feather-pecking (LFP) line of laying hens already differ in their propensity to feather

Keratin homogeneity in the tail feathers of Pavo cristatus and Pavo cristatus mut. alba

OpenAIRE

Pabisch, S.; Puchegger, S.; Kirchner, H.O.K.; Weiss, I.M.; Peterlik, H.

2010-01-01

The keratin structure in the cortex of peacocks? feathers is studied by X-ray diffraction along the feather, from the calamus to the tip. It changes considerably over the first 5?cm close to the calamus and remains constant for about 1?m along the length of the feather. Close to the tip, the structure loses its high degree of order. We attribute the X-ray patterns to a shrinkage of a cylindrical arrangement of ?-sheets, which is not fully formed initially. In the final structure, the crystall...

Reduction of particle emissions from light duty vehicles and from taxies; Reduktion af partikelelemissioner fra varebiler og taxier

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Johan; Henriques, M.; Weibel, T.G. [TetraPlan A/S (Denmark)

2006-11-03

This project, 'Reduction of particle emissions from light duty vehicles and from taxies', analyses different strategies to reduce the particle emission, their effect for particle emissions, and the resulting cost for the society and for the companies. The project describes the EU regulation of emissions, the possibilities of reducing the emissions via special requirements in environmental zones and the Danish taxation of light duty vehicles. Further, the project includes interviews with owners of light duty vehicles and taxies and also with Danish producers of particle filters. The strategies analysed in the scenarios include: 1) Promotion of particle filters; 2) Shift from diesel to gasoline and; 3) Downsizing. The effects for particle emissions and for mortality are described. Further, the costs and benefits for the society and the cost for the companies are evaluated. The effects of the scenarios are analysed, both for initiatives implemented at a national level and for implementation in an environmental zone in the municipality of Copenhagen. The main results are that the socioeconomic benefits in the year 2012 are greater than the costs, if taxis and light duty vehicles have filters installed and if they are driving in the Copenhagen area. For light duty vehicles it is only profitable, if the prices of the filters fall to the price level that is expected in the future in the study. Further, the analysis shows that for light duty vehicles and taxies driving all over the country, the socioeconomic benefits achieved by installing particle filters are too small to cover the costs. The analysis shows that it is also profitable socio-economically to change from diesel to petrol for light duty vehicles and for taxies (except taxies driving nationally). The analysis is based on the producer prices including the general net tax level, while the specific taxes are not included. From the point of view of the companies it is not profitable to change to petrol

Lead accumulation in feathers of nestling black-crowned night-herons (Nycticorax nycticorax) experimentally treated in the field

Science.gov (United States)

Golden, N.H.; Rattner, B.A.; Cohen, J.B.; Hoffman, D.J.; Russek-Cohen, E.; Ottinger, M.A.

2003-01-01

Although lead can attain high concentrations in feathers, interpretation of the biological significance of this phenomenon is difficult. As part of an effort to develop and validate non-invasive methods to monitor contaminant exposure in free-ranging birds, lead uptake by feathers of nestling black-crowned night-herons (Nycticorax nycticorax) was evaluated in a controlled exposure study. Four to six day-old heron nestlings (one/nest) at Chincoteague Bay, Virginia, received a single intraperitoneal injection of dosing vehicle (control; n=7) or a dose of lead nitrate in water (0.01, 0.05, or 0.25 mg Pb/g body weight of nestling; n=6 or 7/dose) chosen to yield feather lead concentrations found at low to moderately polluted sites. Nestlings were euthanized at 15 days of age. Lead accumulation in feathers was associated with concentrations in bone, kidney, and liver (r = 0.32 - 0.74, p feather lead concentration. Culmen growth rate was depressed in nestlings treated with the highest dose of lead, but not correlated with feather lead concentration. These findings provide evidence that feathers of nestling herons are a sensitive indicator of lead exposure and have potential application for the extrapolation of lead concentrations in other tissues and the estimation of environmental lead exposure in birds.

Lead accumulation in feathers of nestling black-crowned night herons (Nycticorax nycticorax) experimentally treated in the field.

Science.gov (United States)

Golden, Nancy H; Rattner, Barnett A; Cohen, Jonathan B; Hoffman, David J; Russek-Cohen, Estelle; Ottinger, Mary Ann

2003-07-01

Although lead can attain high concentrations in feathers, interpretation of the biological significance of this phenomenon is difficult. As part of an effort to develop and validate noninvasive methods to monitor contaminant exposure in free-ranging birds, lead uptake by feathers of nestling black-crowned night herons (Nycticorax nycticorax) was evaluated in a controlled exposure study. Four- to 6-d-old heron nestlings (one/nest) at Chincoteague Bay, Virginia (USA), received a single intraperitoneal injection of dosing vehicle (control, n = 7) or a dose of lead nitrate in water (0.01, 0.05, or 0.25 mg Pb/g body wt of nestling; n = 6 or 7/dose) chosen to yield feather lead concentrations found at low- to moderately polluted sites. Nestlings were euthanized at 15 d of age. Lead accumulation in feathers was associated with concentrations in bone, kidney, and liver (r = 0.32-0.74, p feather lead concentration. Culmen growth rate was depressed in nestlings treated with the highest dose of lead but not correlated with feather lead concentration. These findings provide evidence that feathers of nestling herons are a sensitive indicator of lead exposure and have potential application for the extrapolation of lead concentrations in other tissues and the estimation of environmental lead exposure in birds.

Effects of wing locations on wing rock induced by forebody vortices

Directory of Open Access Journals (Sweden)

Ma Baofeng

2016-10-01

Full Text Available Previous studies have shown that asymmetric vortex wakes over slender bodies exhibit a multi-vortex structure with an alternate arrangement along a body axis at high angle of attack. In this investigation, the effects of wing locations along a body axis on wing rock induced by forebody vortices was studied experimentally at a subcritical Reynolds number based on a body diameter. An artificial perturbation was added onto the nose tip to fix the orientations of forebody vortices. Particle image velocimetry was used to identify flow patterns of forebody vortices in static situations, and time histories of wing rock were obtained using a free-to-roll rig. The results show that the wing locations can affect significantly the motion patterns of wing rock owing to the variation of multi-vortex patterns of forebody vortices. As the wing locations make the forebody vortices a two-vortex pattern, the wing body exhibits regularly divergence and fixed-point motion with azimuthal variations of the tip perturbation. If a three-vortex pattern exists over the wing, however, the wing-rock patterns depend on the impact of the highest vortex and newborn vortex. As the three vortices together influence the wing flow, wing-rock patterns exhibit regularly fixed-points and limit-cycled oscillations. With the wing moving backwards, the newborn vortex becomes stronger, and wing-rock patterns become fixed-points, chaotic oscillations, and limit-cycled oscillations. With further backward movement of wings, the vortices are far away from the upper surface of wings, and the motions exhibit divergence, limit-cycled oscillations and fixed-points. For the rearmost location of the wing, the wing body exhibits stochastic oscillations and fixed-points.

Adrenocortical reactivity and central serotonin and dopamine turnover in young chicks from a high and low feather-pecking line of laying hens

OpenAIRE

van Hierden, YM; Korte, SM; Ruesink, EW; van Reenen, CG; Engel, B; Korte-Bouws, GAH; Koolhaas, JM; Blokhuis, HJ

2002-01-01

Feather pecking in domestic fowl is a behavioral abnormality that consists of mild or injurious pecking at feathers of conspecifics. Previously, it was shown that chicks from a high feather-pecking (HFP) and low feather-pecking (LFP) line of laying hens already differ in their propensity to feather peck at 14 and 28 days of age. As a first step in investigating a possible relationship between the development of feather pecking and physiological and neurobiological characteristics of laying he...

Biogas Production from Citrus Wastes and Chicken Feather: Pretreatment and Codigestion

Energy Technology Data Exchange (ETDEWEB)

Forgacs, Gergely

2012-07-01

Anaerobic digestion is a sustainable and economically feasible waste management technology, which lowers the emission of greenhouse gases (GHGs), decreases the soil and water pollution, and reduces the dependence on fossil fuels. The present thesis investigates the anaerobic digestion of waste from food-processing industries, including citrus wastes (CWs) from juice processing and chicken feather from poultry slaughterhouses. Juice processing industries generate 15-25 million tons of citrus wastes every year. Utilization of CWs is not yet resolved, since drying or incineration processes are costly, due to the high moisture content; and biological processes are hindered by its peel oil content, primarily the D-limonene. Anaerobic digestion of untreated CWs consequently results in process failure because of the inhibiting effect of the produced and accumulated VFAs. The current thesis involves the development of a steam explosion pretreatment step. The methane yield increased by 426 % to 0.537 Nm{sup 3}/kg VS by employing the steam explosion treatment at 150 deg C for 20 min, which opened up the compact structure of the CWs and removed 94 % of the D-limonene. The developed process enables a production of 104 m{sup 3} methane and 8.4 L limonene from one ton of fresh CWs. Poultry slaughterhouses generate a significant amount of feather every year. Feathers are basically composed of keratin, an extremely strong and resistible structural protein. Methane yield from feather is low, around 0.18 Nm{sup 3}/kg VS, which corresponds to only one third of the theoretical yield. In the present study, chemical, enzymatic and biological pretreatment methods were investigated to improve the biogas yield of feather waste. Chemical pretreatment with Ca(OH){sub 2} under relatively mild conditions (0.1 g Ca(OH){sub 2}/g TS{sub feather}, 100 deg C, 30 min) improved the methane yield to 0.40 Nm{sup 3}/kg VS, corresponding to 80 % of the theoretical yield. However, prior to digestion, the

Integrating toxicity risk in bird eggs and chicks: using chick down feathers to estimate mercury concentrations in eggs.

Science.gov (United States)

Ackerman, Joshua T; Eagles-Smith, Collin A

2009-03-15

The concentration of mercury (Hg) in eggs that causes reduced hatching success is regarded as a critical end point for Hg toxicity in birds. However, incorporating effects of in ovo mercury exposure on chick health and survival could improve risk assessment. We developed equations to predict Hg in eggs using Hg in chick down feathers, and vice versa, by assessing the relationship between Hg in feathers (0.5-32.4 microg g(-1) fw) and eggs (0.04-2.79 microg g(-1) fww) for three waterbird species in San Francisco Bay, CA. Feather Hg sampled from embryos of pipping eggs was highly correlated with fresh whole-egg Hg (n=94, r2 = 0.96). Additionally, using an egg microsampling technique, albumen Hg was correlated with feather Hg sampled from chicks in the same nest (n=28, r2 = 0.79). Down feather Hg in recaptured chicks (feather Hg at hatching (feathers of chicks < or =10 days of age to nonlethally predict Hg in eggs and thus provide the ability to develop exposure thresholds for eggs that incorporate in ovo Hg's effects on both egg hatchability and subsequent chick mortality.

VARIANCE COMPONENTS AND SELECTION FOR FEATHER PECKING BEHAVIOR IN LAYING HENS

OpenAIRE

Su, Guosheng; Kjaer, Jørgen B.; Sørensen, Poul

2005-01-01

Variance components and selection response for feather pecking behaviour were studied by analysing the data from a divergent selection experiment. An investigation show that a Box-Cox transformation with power =-0.2 made the data be approximately normally distributed and fit best by the given model. Variance components and selection response were estimated using Bayesian analysis with Gibbs sampling technique. The total variation was rather large for the two traits in both low feather peckin...

Variance components and selection response for feather-pecking behavior in laying hens.

Science.gov (United States)

Su, G; Kjaer, J B; Sørensen, P

2005-01-01

Variance components and selection response for feather pecking behavior were studied by analyzing the data from a divergent selection experiment. An investigation indicated that a Box-Cox transformation with power lambda = -0.2 made the data approximately normally distributed and gave the best fit for the model. Variance components and selection response were estimated using Bayesian analysis with Gibbs sampling technique. The total variation was rather large for the investigated traits in both the low feather-pecking line (LP) and the high feather-pecking line (HP). Based on the mean of marginal posterior distribution, in the Box-Cox transformed scale, heritability for number of feather pecking bouts (FP bouts) was 0.174 in line LP and 0.139 in line HP. For number of feather-pecking pecks (FP pecks), heritability was 0.139 in line LP and 0.105 in line HP. No full-sib group effect and observation pen effect were found in the 2 traits. After 4 generations of selection, the total response for number of FP bouts in the transformed scale was 58 and 74% of the mean of the first generation in line LP and line HP, respectively. The total response for number of FP pecks was 47 and 46% of the mean of the first generation in line LP and line HP, respectively. The variance components and the realized selection response together suggest that genetic selection can be effective in minimizing FP behavior. This would be expected to reduce one of the major welfare problems in laying hens.

Feather bedding and childhood asthma associated with house dust mite sensitisation: a randomised controlled trial.

Science.gov (United States)

Glasgow, Nicholas J; Ponsonby, Anne-Louise; Kemp, Andrew; Tovey, Euan; van Asperen, Peter; McKay, Karen; Forbes, Samantha

2011-06-01

Observational studies report inverse associations between the use of feather upper bedding (pillow and/or quilt) and asthma symptoms but there is no randomised controlled trial (RCT) evidence assessing the role of feather upper bedding as a secondary prevention measure. To determine whether, among children not using feather upper bedding, a new feather pillow and feather quilt reduces asthma severity among house dust mite (HDM) sensitised children with asthma over a 1-year period compared with standard dust mite avoidance advice, and giving children a new mite-occlusive mattress cover. RCT. The Calvary Hospital in the Australian Capital Territory and the Children's Hospital at Westmead, Sydney, New South Wales. 197 children with HDM sensitisation and moderate to severe asthma. Intervention New upper bedding duck feather pillow and quilt and a mite-occlusive mattress cover (feather) versus standard care and a mite-occlusive mattress cover (standard). The proportion of children reporting four or more episodes of wheeze in the past year; an episode of speech-limiting wheeze; or one or more episodes of sleep disturbance caused by wheezing; and spirometry with challenge testing. Statistical analysis included multiple logistic and linear regression. No differences between groups were found for primary end points--frequent wheeze (OR 1.51, 95% CI 0.83 to 2.76, p=0.17), speech-limiting wheeze (OR 0.70, 95% CI 0.32 to 1.48, p=0.35), sleep disturbed because of wheezing (OR 1.17, 95% CI 0.64 to 2.13, p=0.61) or for any secondary end points. Secondary analyses indicated the intervention reduced the risk of sleep being disturbed because of wheezing and severe wheeze to a greater extent for children who slept supine. No differences in respiratory symptoms or lung function were observed 1 year after children with moderate-severe asthma and HDM sensitisation were given a mite-occlusive mattress cover and then received either feather upper bedding (pillow and quilt) or standard

Hide depilation and feather disintegration studies with keratinolytic serine protease from a novel Bacillus subtilis isolate.

Science.gov (United States)

Pillai, Priya; Archana, G

2008-03-01

Keratinases play an important role in biotechnological applications such as improvement of feather meal, enzymatic dehairing and production of amino acids or peptides from high molecular weight substrates. Bacillus subtilis P13, isolated from Vajreshwari hot spring (45-50 degrees C) near Mumbai, India, produces a neutral serine protease and has an optimum temperature of 65 degrees C. This enzyme preparation was keratinolytic in nature and could disintegrate whole chicken feathers, except for the remnants of shafts. The enzyme preparation also exhibited depilation of goat hides with the recovery of intact animal hair. The enzyme preparation could release peptides from ground feathers and bring about their weight reduction; however, similar action on hair was relatively weak. A single major PMSF-sensitive protease band could be detected upon zymogram analysis, indicating that a single enzyme may be responsible for feather degradation and hide depilation. The importance of these findings in the biotechnological application for feather and leather industries is discussed.

Development of colour-producing β-keratin nanostructures in avian feather barbs

Science.gov (United States)

Prum, Richard O.; Dufresne, Eric R.; Quinn, Tim; Waters, Karla

2009-01-01

The non-iridescent structural colours of avian feather barbs are produced by coherent light scattering from amorphous (i.e. quasi-ordered) nanostructures of β-keratin and air in the medullary cells of feather barb rami. Known barb nanostructures belong to two distinct morphological classes. ‘Channel’ nanostructures consist of β-keratin bars and air channels of elongate, tortuous and twisting forms. ‘Spherical’ nanostructures consist of highly spherical air cavities that are surrounded by thin β-keratin bars and sometimes interconnected by tiny passages. Using transmission electron microscopy, we observe that the colour-producing channel-type nanostructures of medullary β-keratin in feathers of the blue-and-yellow macaw (Ara ararauna, Psittacidae) develop by intracellular self-assembly; the process proceeds in the absence of any biological prepattern created by the cell membrane, endoplasmic reticulum or cellular intermediate filaments. We examine the hypothesis that the shape and size of these self-assembled, intracellular nanostructures are determined by phase separation of β-keratin protein from the cytoplasm of the cell. The shapes of a broad sample of colour-producing channel-type nanostructures from nine avian species are very similar to those self-assembled during the phase separation of an unstable mixture, a process called spinodal decomposition (SD). In contrast, the shapes of a sample of spherical-type nanostructures from feather barbs of six species show a poor match to SD. However, spherical nanostructures show a strong morphological similarity to morphologies produced by phase separation of a metastable mixture, called nucleation and growth. We propose that colour-producing, intracellular, spongy medullary β-keratin nanostructures develop their characteristic sizes and shapes by phase separation during protein polymerization. We discuss the possible role of capillary flow through drying of medullary cells in the development of the hollow

Development of colour-producing beta-keratin nanostructures in avian feather barbs.

Science.gov (United States)

Prum, Richard O; Dufresne, Eric R; Quinn, Tim; Waters, Karla

2009-04-06

The non-iridescent structural colours of avian feather barbs are produced by coherent light scattering from amorphous (i.e. quasi-ordered) nanostructures of beta-keratin and air in the medullary cells of feather barb rami. Known barb nanostructures belong to two distinct morphological classes. 'Channel' nanostructures consist of beta-keratin bars and air channels of elongate, tortuous and twisting forms. 'Spherical' nanostructures consist of highly spherical air cavities that are surrounded by thin beta-keratin bars and sometimes interconnected by tiny passages. Using transmission electron microscopy, we observe that the colour-producing channel-type nanostructures of medullary beta-keratin in feathers of the blue-and-yellow macaw (Ara ararauna, Psittacidae) develop by intracellular self-assembly; the process proceeds in the absence of any biological prepattern created by the cell membrane, endoplasmic reticulum or cellular intermediate filaments. We examine the hypothesis that the shape and size of these self-assembled, intracellular nanostructures are determined by phase separation of beta-keratin protein from the cytoplasm of the cell. The shapes of a broad sample of colour-producing channel-type nanostructures from nine avian species are very similar to those self-assembled during the phase separation of an unstable mixture, a process called spinodal decomposition (SD). In contrast, the shapes of a sample of spherical-type nanostructures from feather barbs of six species show a poor match to SD. However, spherical nanostructures show a strong morphological similarity to morphologies produced by phase separation of a metastable mixture, called nucleation and growth. We propose that colour-producing, intracellular, spongy medullary beta-keratin nanostructures develop their characteristic sizes and shapes by phase separation during protein polymerization. We discuss the possible role of capillary flow through drying of medullary cells in the development of the

Feather pecking in chickens is genetically related to behavioural and developmental traits.

Science.gov (United States)

Jensen, P; Keeling, L; Schütz, K; Andersson, L; Mormède, P; Brändström, H; Forkman, B; Kerje, S; Fredriksson, R; Ohlsson, C; Larsson, S; Mallmin, H; Kindmark, A

2005-09-15

Feather pecking (FP) is a detrimental behaviour in chickens, which is performed by only some individuals in a flock. FP was studied in 54 red junglefowl (ancestor of domestic chickens), 36 White Leghorn laying hens, and 762 birds from an F(2)-intercross between these two lines. From all F(2)-birds, growth and feed consumption were measured. Age at sexual maturity and egg production in females, and corticosterone levels in males were also measured. From 333 F(2)-birds of both sexes, and 20 parental birds, body composition with respect to bone mineral content, muscle and fat was obtained by post-mortem examinations using Dual X-Ray Absorptiometry (DXA). In femurs of the same birds, the bone density and structure were analysed using DXA and Peripheral Quantitative Computerized Tomography (pQCT), and a biomechanical analysis of bone strength was performed. Furthermore, plumage condition was determined in all birds as a measure of being exposed to feather pecking. Using 105 DNA-markers in all F(2)-birds, a genome-wide scan for Quantitative Trait Loci (QTL), associated with the behaviour in the F(2)-generation was performed. FP was at least as frequent in the red junglefowl as in the White Leghorn strain studied here, and significantly more common among females both in the parental strains and in the F(2)-generation. In the F(2)-birds, FP was phenotypically linked to early sexual maturation, fast growth, weak bones, and, in males, also high fat accumulation, indicating that feather peckers have a different resource allocation pattern. Behaviourally, F(2) feather peckers were more active in an open field test, in a novel food/novel object test, and in a restraint test, indicating that feather pecking might be genetically linked to a proactive coping strategy. Only one suggestive QTL with a low explanatory value was found on chromosome 3, showing that many genes, each with a small effect, are probably involved in the causation of feather pecking. There were significant

Comparison of four feed proteases for improvement of nutritive value of poultry feather meal

DEFF Research Database (Denmark)

Pedersen, Mads Brøgger; Yu, S; Plumstead, P

2012-01-01

in the production of cost-effective feather by-products for use as feed and fertilizers. The current study examined 4 commercial feed proteases from Bacillus subtilis, Bacillus licheniformis PWD-1, Aspergillus niger, and Serratia proteamaculans HY-3 used to hydrolyze chicken feather under different conditions...

Diverse uses of feathers with emphasis on diagnosis of avian viral infections and vaccine virus monitoring

Directory of Open Access Journals (Sweden)

I Davidson

2009-09-01

Full Text Available The large amounts of feathers produced by the poultry industry, that is considered as a waste was explored for possible uses in various industries, such as meals for animals, biofuels, biodegradable plastic materials, combating water pollution and more. That review mentions these uses, but concentrate on the utilization of feathers for the diagnosis of viral infections and for monitoring vaccine viruses in chickens after vaccination. The viral diseases in which diagnosis using nucleic acids extracted from the feather shafts was described are, Marek's disease virus, circoviruses, chicken anemia virus, fowlpox virus, avian retroviruses, avian influenza virus and infectious laryngotracheitis virus. In two cases, of Marek's disease virus and of infectious laryngotracheitis virus, the differentiation of vaccine and wild-type viruses from feather shafts was made possible, thus allowing for monitoring the vaccination efficacy. The present review demonstrates also the stability of DNA viruses in feather shafts, and the possible evaluation of environmental dissemination of pathogens. When viruses are transmitted vertically, like in the cases of the retrovirus REV, a teratogenic effect on the development of feathers of the day-old newly hatched chick might occur in the case of avian influenza and the chicken anemia virus, which might indicate on a viral infection.

Poultry feather wastes recycling possibility as soil nutrient

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Lili Mézes

2015-10-01

Full Text Available Poultry feathers are produced in large amounts as a waste in poultry slaughterhouses. Only 60-70% of the poultry slaughterhouse products are edible for human being. This means more million tons annually worldwide (Papadopoulus et al., 1986; Williams et al., 1991; Hegedűs et al., 1998. The keratin-content of feather can be difficulty digested, so physical, chemical and/or biological pre-treatment are needed in practice, which have to be set according to the utilization method. Feather was enzymatic degraded, and then fermented in separated bioreactors. The anaerobic bioreactor system (4 digesters with 6 litre volume was controlled by ACE SCADA software running on Linux platforms. Pot scale seed germination tests were established to suggest the quantity of digested slurry to be utilized. The chosen test plants were lettuce (Lactuca sativa. In case of reproduction test Student’s t-test was applied to examine significant differences between the root lengths of the control and the treated plant species. In case of pot seed germination variance analysis with Tukey B’s and Duncan test was applied to examine significant differences between the root lengths of plants, grown on different treatments. The effect of treatments on germination ability of the plant species was expressed in the percentage of the controls. According to Student’s t-test significant difference was found between root lengths of different treatments. Based on variance analysis with Tukey B’s and Duncan tests could be detected a significant difference between the treatments. Utilization of the fermented material reduces the use of fertilizers and because of its large moisture content it reduces the watering costs. Recycle of the slaughterhouse feather and different agricultural wastes and by-products can solve three main problems: disposal of harmful materials, producing of renewable energy and soil nutrient, measuring reflectance at the certain spectral range, which can

Butterfly wing colours : scale beads make white pierid wings brighter

NARCIS (Netherlands)

Stavenga, DG; Stowe, S; Siebke, K; Zeil, J; Arikawa, K

2004-01-01

The wing-scale morphologies of the pierid butterflies Pieris rapae (small white) and Delias nigrina (common jezabel), and the heliconine Heliconius melpomene are compared and related to the wing-reflectance spectra. Light scattering at the wing scales determines the wing reflectance, but when the

Keratin subsidies promote feather decomposition via an increase in keratin-consuming arthropods and microorganisms in bird breeding colonies.

Science.gov (United States)

Sugiura, Shinji; Masuya, Hayato

2015-06-01

Resource subsidies are well known to increase population densities of consumers. The decomposition process of these subsidised resources can be influenced by increasing consumer abundance. However, few studies have assessed whether resource subsidies can promote resource decomposition via a population increase in consumers. Here, we examined the effects of keratin subsidies on feather decomposition in egret and heron breeding colonies. Egrets and herons (Ardeidae) frequently breed in inland forests and provide large amounts of keratin materials to the forest floor in the form of feathers of chicks (that die). We compared the decrease in the weights of egret and heron feathers (experimentally placed on the forest floor) over a 12-month period among egret/heron breeding colonies (five sites) and areas outside of colonies (five sites) in central Japan. Of the feathers placed experimentally on forest floors, 92-97 % and 99-100 % in colonies and 47-50 % and 71-90 % in non-colony areas were decomposed after 4 and 12 months, respectively. Then, decomposition rates of feathers were faster in colonies than in areas outside of colonies, suggesting that keratin subsidies can promote feather decomposition in colonies. Field observations and laboratory experiments indicated that keratin-feeding arthropods and keratinophilic fungi played important roles in feather decomposition. Therefore, scavenging arthropods and keratinophilic fungi, which dramatically increased in egret and heron breeding colonies, could accelerate the decomposition of feathers supplied to the forest floor of colonies.

Manakins can produce iridescent and bright feather colours without melanosomes.

Science.gov (United States)

Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

2016-06-15

Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments. © 2016. Published by The Company of Biologists Ltd.

41 CFR 301-10.421 - How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy...

Science.gov (United States)

2010-07-01

... reimburse me for a tip to a taxi, shuttle service, or courtesy transportation driver? 301-10.421 Section 301..., Shuttle Services, Or Other Courtesy Transportation § 301-10.421 How much will my agency reimburse me for a tip to a taxi, shuttle service, or courtesy transportation driver? An amount which your agency...

Feather mites (Acari, Astigmata associated with birds in an Atlantic Forest fragment in Northeastern Brazil

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HM Silva

Full Text Available AbstractThe present study reports associations between feather mites (Astigmata and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fifteen feather mite taxa could be identified to the species level, sixteen to the genus level and three to the subfamily level, distributed into the families Analgidae, Proctophyllodidae, Psoroptoididae, Pteronyssidae, Xolalgidae, Trouessartiidae, Falculiferidae and Gabuciniidae. Hitherto unknown associations between feather mites and birds were recorded for eleven taxa identified to the species level, and nine taxa were recorded for the first time in Brazil. The number of new geographic records, as well as the hitherto unknown mite-host associations, supports the high estimates of diversity for feather mites of Brazil and show the need for research to increase knowledge of plumicole mites in the Neotropical region.

Analysis of severe feather pecking behavior in a high feather pecking selection line

DEFF Research Database (Denmark)

Labouriau, R; Kjaer, J B; Abreu, G C G

2009-01-01

Even though feather pecking (FP) in laying hens has been extensively studied, a good solution to prevent chickens from this behavior under commercial circumstances has not been found. Selection against FP behavior is possible, but for a more effective selection across different populations......, it is necessary to characterize the genetic mechanism associated with this behavior. In this study, we use a high FP selection line, which has been selected for 8 generations. We present evidence of the presence of a major dominant allele affecting the FP behavior by using an argument based on the presence...

The leading-edge vortex of swift wing-shaped delta wings.

Science.gov (United States)

Muir, Rowan Eveline; Arredondo-Galeana, Abel; Viola, Ignazio Maria

2017-08-01

Recent investigations on the aerodynamics of natural fliers have illuminated the significance of the leading-edge vortex (LEV) for lift generation in a variety of flight conditions. A well-documented example of an LEV is that generated by aircraft with highly swept, delta-shaped wings. While the wing aerodynamics of a manoeuvring aircraft, a bird gliding and a bird in flapping flight vary significantly, it is believed that this existing knowledge can serve to add understanding to the complex aerodynamics of natural fliers. In this investigation, a model non-slender delta-shaped wing with a sharp leading edge is tested at low Reynolds number, along with a delta wing of the same design, but with a modified trailing edge inspired by the wing of a common swift Apus apus . The effect of the tapering swift wing on LEV development and stability is compared with the flow structure over the unmodified delta wing model through particle image velocimetry. For the first time, a leading-edge vortex system consisting of a dual or triple LEV is recorded on a swift wing-shaped delta wing, where such a system is found across all tested conditions. It is shown that the spanwise location of LEV breakdown is governed by the local chord rather than Reynolds number or angle of attack. These findings suggest that the trailing-edge geometry of the swift wing alone does not prevent the common swift from generating an LEV system comparable with that of a delta-shaped wing.

Development of a micro-hybrid system for a three-wheeled motor taxi

NARCIS (Netherlands)

Hofman, T.; Tas, van der S.G.; Ooms, W.; Van Meijl, E. W P; Laugeman, B. M.

2009-01-01

In large cities in Asia and Africa millions of auto-rickshaws offer their taxi-services. At the same time these three-wheelers cause severe air-pollution and produce large amounts of green house gasses (carbon dioxide). The goal of the research presented in this paper is to develop a compact, robust

Relation between workplace accidents and the levels of carboxyhemoglobin in motorcycle taxi drivers.

Science.gov (United States)

da Silva, Luiz Almeida; Robazzi, Maria Lúcia do Carmo Cruz; Terra, Fábio de Souza

2013-01-01

To investigate the relation between workplace accidents and the levels of carboxyhemoglobin found in motorcycle taxi drivers. Correlational, quantitative study involving 111 workers and data obtained in July 2012 through a questionnaire to characterize the participants and blood collection to measure carboxyhemoglobin levels. 28.8% had suffered workplace accidents; 27.6% had fractured the lower limbs and significant symptoms of carbon monoxide exposure were verified in smokers. The carboxyhemoglobin levels were higher among smokers and victims of workplace accidents. Motorcycle taxi drivers had increased levels of carboxyhemoglobin, possibly due to the exposure to carbon monoxide; these levels are also increased among smokers and victims of workplace accidents. The study provides advances in the knowledge about occupational health and environmental science, and also shows that carboxyhemoglobin can be an indicator of exposure to environmental pollutants for those working outdoors, which can be related to workplace accidents.

Feather mites (Acari, Astigmata from Azorean passerines (Aves, Passeriformes: lower species richness compared to European mainland

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Rodrigues Pedro

2015-01-01

Full Text Available Ten passerine species were examined on three islands of the Azores (North Atlantic during 2013 and 2014 in order to identify their feather mite assemblages. We recorded 19 feather mite species belonging to four families of the superfamily Analgoidea (Analgidae, Proctophyllodidae, Psoroptoididae and Trouessartiidae. A high prevalence of feather mite species was recorded on the majority of the examined host species. Only three passerine species (Sylvia atricapilla, Regulus regulus and Serinus canaria presented the same full complex of mite species as commonly occurs in the plumage of their closest relatives in continental Europe. Passer domesticus presented the same limited fauna of feather mites living in the plumage as do its co-specifics in continental Europe. Carduelis carduelis bears the same feather mite species as do most of its continental populations in Europe, but it lacks one mite species occurring on this host in Egypt. Turdus merula, Pyrrhula murina and Fringilla coelebs are missing several mite species common to their continental relatives. This diminution could be explained by the founder effect, whereby a limited number of colonizing individuals did not transport the full set of feather mite species, or by the extinction of some mite species after initially having reached the Azores. The only individual of Motacilla cinerea sampled in this study presented a new host record for the mite species Trouessartia jedliczkai.

Prediction of safe driving Behaviours based on health belief model: the case of taxi drivers in Bandar Abbas, Iran.

Science.gov (United States)

Razmara, Asghar; Aghamolaei, Teamur; Madani, Abdoulhossain; Hosseini, Zahra; Zare, Shahram

2018-03-20

Road accidents are among the main causes of mortality. As safe and secure driving is a key strategy to reduce car injuries and offenses, the present research aimed to explore safe driving behaviours among taxi drivers based on the Health Belief Model (HBM). This study was conducted on 184 taxi drivers in Bandar Abbas who were selected based on a multiple stratified sampling method. Data were collected by a questionnaire comprised of a demographic information section along with the constructs of the HBM. Data were analysed by SPSS ver19 via a Pearson's correlation coefficient and multiple regressions. The mean age of the participants was 45.1 years (SD = 11.1). They all had, on average, 10.3 (SD = 7/5) years of taxi driving experience. Among the HBM components, cues to action and perceived benefits were shown to be positively correlated with safe driving behaviours, while perceived barriers were negatively correlated. Cues to action, perceived barriers and perceived benefits were shown to be the strongest predictors of a safe drivers' behaviour. Based on the results of this study in designing health promotion programmes to improve safe driving behaviours among taxi drivers, cues to action, perceived benefits and perceived barriers are important. Therefore, advertising, the design of information campaigns, emphasis on the benefits of safe driving behaviours and modification barriers are recommended.

Feather barbs as a good source of mtDNA for bird species identification in forensic wildlife investigations.

Science.gov (United States)

Speller, Camilla F; Nicholas, George P; Yang, Dongya Y

2011-07-28

The ability to accurately identify bird species is crucial for wildlife law enforcement and bird-strike investigations. However, such identifications may be challenging when only partial or damaged feathers are available for analysis. By applying vigorous contamination controls and sensitive PCR amplification protocols, we found that it was feasible to obtain accurate mitochondrial (mt)DNA-based species identification with as few as two feather barbs. This minimally destructive DNA approach was successfully used and tested on a variety of bird species, including North American wild turkey (Meleagris gallopavo), Canada goose (Branta canadensis), blue heron (Ardea herodias) and pygmy owl (Glaucidium californicum). The mtDNA was successfully obtained from 'fresh' feathers, historic museum specimens and archaeological samples, demonstrating the sensitivity and versatility of this technique. By applying appropriate contamination controls, sufficient quantities of mtDNA can be reliably recovered and analyzed from feather barbs. This previously overlooked substrate provides new opportunities for accurate DNA species identification when minimal feather samples are available for forensic analysis.

Feather bedding and childhood asthma associated with house dust mite sensitisation : a randomised controlled trial

NARCIS (Netherlands)

Glasgow, Nicholas J.; Ponsonby, Anne-Louise; Kemp, Andrew; Tovey, Euan; van Asperen, Peter; McKay, Karen; Forbes, Samantha

Introduction Observational studies report inverse associations between the use of feather upper bedding (pillow and/or quilt) and asthma symptoms but there is no randomised controlled trial (RCT) evidence assessing the role of feather upper bedding as a secondary prevention measure. Objective To

Sexual dimorphism in melanin pigmentation, feather coloration and its heritability in the barn swallow (Hirundo rustica.

Directory of Open Access Journals (Sweden)

Nicola Saino

Full Text Available Melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin in pigmented tissues exists among populations and individuals. Melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. However, with few notable exceptions, little detailed information is available on inter-individual and inter-population variation in melanin pigmentation and on its environmental, genetic and ontogenetic components. Here, we investigate melanin-based coloration in an Italian population of a passerine bird, the barn swallow (Hirundo rustica rustica, its sex- and age-related variation, and heritability. The concentrations of eu- and pheomelanin in the throat (brown and belly (white-to-brownish feathers differed between sexes but not according to age. The relative concentration of either melanin (Pheo:Eu differed between sexes in throat but not in belly feathers, and the concentrations in males compared to females were larger in belly than in throat feathers. There were weak correlations between the concentrations of melanins within as well as among plumage regions. Coloration of belly feathers was predicted by the concentration of both melanins whereas coloration of throat feathers was only predicted by pheomelanin in females. In addition, Pheo:Eu predicted coloration of throat feathers in females and that of belly feathers in males. Finally, we found high heritability of color of throat feathers. Melanization was found to differ from that recorded in Hirundo rustica rustica from Scotland or from H. r. erythrogaster from North America. Hence, present results show that pigmentation strategies vary in a complex manner according to sex and plumage region, and also among geographical populations

Effect of Sex-linked Feathering Genes on Body Weight, Age At Sexual Maturity, Feed Intake and Subsequent Laying Performance of Baladi Chickens

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A. AI-Sobayel

1997-01-01

Full Text Available A total of 320 twenty week-old slow and rapid feathering Saudi Arabian Baladi pullers were used to assess the effect of sex-linked feathering genes on body weight, age at sexual maturity, feed intake and subsequent laying performance. Similar numbers of rapid feathering Leghorns pullets were included in the study for the purpose of comparison. The experimental birds of each genotypic group were randomly divided into four replicates and subjected to standard management practices. Slow feathering Baladi pullers had higher (P<0.05 adult body weight, rate of mortality, and feed intake and a similar age at sexual maturity but showed lower (P< 0.05 hen-day, and hen-housed egg production and feed conversion compared with rapid feathering Baladi pullets. Rapid feathering Leghorns had higher (P<0.05 adult body weight. age at sexual maturity, hen-day egg production, rate of mortality and feed intake and lower feed intake/kg eggs than rapid and slow feathering Baladi. However, rapid feathering Baladi and Leghorns had similar hen-housed egg production and feed intake per dozen eggs and had better (l’<0.05' performance than slow feathering Baladi.

Pattern of seat belt use and its associated factors among taxi drivers ...

African Journals Online (AJOL)

Objective: Road traffic injuries constitute a major public health concern that demands effective interventions. Use of car seat belts is recommended as an effective intervention to reduce serious and fatal road traffic injuries. The study intended to investigate the pattern of seat belt use and its correlates among taxi drivers in ...

Divergent primary moult-A rare moult sequence among Western Palaearctic passerines.

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Yosef Kiat

Full Text Available Wing morphology strongly affects flight performance which may consequently decline during feather moult due to the creation of feather gaps in the wing. Hence, the size and shape of moult-related wing gap may directly affect flight capacity. Here I examined the rare divergent primary moult sequence compared to the more common descendant moult sequence. In the divergent moult, the focus of primary moult is shifted from P1 (primary feather numbered descendantly to another primary between P2 and P5, and then primaries are moulted in two concurrent waves, one descendant and the other ascendant. The result of this rare moult sequence is the splitting of the wing gap to two smaller gaps. Using a large moult database including 6,763 individuals of 32 Western Palaearctic passerine species, I found evidence of divergent moult only among 27 individuals of 12 species. I examined the speed of wing-feather moult for each individual that moulted divergently compared to a control group of individuals at the same moult stage which moulted following the common descending sequence. The results indicate that the sequence of primary moult and moult speed are correlated. Individuals which moulted divergently moulted their primaries with higher moult speed than descendant moulters. The applicability of this study is weakened by the dearth of moult data, thus making it difficult to draw conclusions for a large range of species. Ornithologists and bird ringers are therefore encouraged to collect more basic moult data during their field study.

Effect of an early bitter taste experience on subsequent feather-pecking behaviour in laying hens

NARCIS (Netherlands)

Harlander, A.; Beck, P.S.A.; Rodenburg, T.B.

2010-01-01

Recent studies showed that laying hens learn not to peck at bitter-tasting feathers from conspecifics. In the present experiment, feathers of newly hatched chicks were made distasteful by spraying them with a bitter-tasting substance (quinine). It was hypothesized that chicks could detect quinine

Fracture toughness of zirconia ceramic crowns made by feather-edge tooth preparation design

Directory of Open Access Journals (Sweden)

Mirković Nemanja

2012-01-01

Full Text Available Background/Aim. Fracture toughness determines functional crown strenght and prevents damages on ceramics during mastication. There is a lack of relevant literature data about fracture toughness of crowns made by feather-edge preparation. Mechanical testing of ceramic samples is supposed to show if feather-edge tooth preparation is a successful method for making ceramic crowns without any risk of reduction of their mechanical properties. This research was done to establish effects of feather-edge tooth preparation on fracture toughness of single zirconia ceramic crowns. Methods. The research was performed as an experimental study. Sixty (60 ceramic crowns were made on non-carious extracted human premolars. Thirty (30 crowns were made on the basis of feather-edge preparation (experimental group I. The group II included 30 crowns made on 1 mm rounded shoulder. Crowns fabrication was executed on a copy mill production system “Zirkonzahn” (Zirkonzahn GMBH, Gais, Germany. The spherical compression test was used to determine fracture toughness, using 6 mm diameter ceramic ball. Fracture load for damaging ceramic crown was recorded on a universal testing machine - Zwick, type 1464, with the speed of 0.05 mm/min. Results. The results of this research introduced significant differences between fracture toughness of ceramic samples in every examined group. However, fracture toughness of crowns from both group was above 2 000 N, what was double beyond a recommended value. The mean value of fracture toughness in the feather-edge group was 2 090 N, and in shoulder group it was 2 214 N. Conclusion. This research showed a high fracture toughness of zirconia crowns made on feather-edge preparation. The examined crowns showed a fracture resistance at a sufficient distance in relation to the minimum values of functional loads. Further research of functional loads of these crown is necessary, as well as research of marginal adaptation of cemented crowns and

Directional reflectance and milli-scale feather morphology of the African Emerald Cuckoo, Chrysococcyx cupreus.

Science.gov (United States)

Harvey, Todd Alan; Bostwick, Kimberly S; Marschner, Steve

2013-09-06

Diverse plumages have evolved among birds through complex morphological modifications. We investigate how the interplay of light with surface and subsurface feather morphology determines the direction of light propagation, an understudied aspect of avian visual signalling. We hypothesize that milli-scale modifications of feathers produce anisotropic reflectance, the direction of which may be predicted by the orientation of the milli-scale structure. The subject of this study is the African Emerald Cuckoo, Chrysococcyx cupreus, noted for its shimmering green iridescent appearance. Using a spherical gantry, we measured the change in the directional reflectance across the feather surface and over a hemisphere of incident lighting directions. Using a microCT scanner, we also studied the morphology of the structural branches of the barb. We tracked the changes in the directional reflectance to the orientation of the structural branches as observed in the CT data. We conclude that (i) the far-field signal of the feather consists of multiple specular components, each associated with a different structural branch and (ii) the direction of each specular component is correlated to the orientation of the corresponding structure.

The leading-edge vortex of swift-wing shaped delta wings

Science.gov (United States)

Muir, Rowan; Arredondo-Galeana, Abel; Viola, Ignazio Maria

2017-11-01

Recent investigations on the aerodynamics of natural fliers have illuminated the significance of the Leading-Edge Vortex (LEV) for lift generation in a variety of flight conditions. In this investigation, a model non-slender delta shaped wing with a sharp leading-edge is tested at low Reynolds Number, along with a delta wing of the same design, but with a modified trailing edge inspired by the wing of a common swift Apus apus. The effect of the tapering swift wing on LEV development and stability is compared with the flow structure over the un-modified delta wing model through particle image velocimetry. For the first time, a leading-edge vortex system consisting of a dual or triple LEV is recorded on a swift-wing shaped delta wing, where such a system is found across all tested conditions. It is shown that the spanwise location of LEV breakdown is governed by the local chord rather than Reynolds Number or angle of attack. These findings suggest that the trailing-edge geometry of the swift wing alone does not prevent the common swift from generating an LEV system comparable with that of a delta shaped wing. This work received funding from the Engineering and Physical Sciences Research Council [EP/M506515/1] and the Consejo Nacional de Ciencia y Tecnología (CONACYT).

Amorphous diamond-structured photonic crystal in the feather barbs of the scarlet macaw.

Science.gov (United States)

Yin, Haiwei; Dong, Biqin; Liu, Xiaohan; Zhan, Tianrong; Shi, Lei; Zi, Jian; Yablonovitch, Eli

2012-07-03

Noniridescent coloration by the spongy keratin in parrot feather barbs has fascinated scientists. Nonetheless, its ultimate origin remains as yet unanswered, and a quantitative structural and optical description is still lacking. Here we report on structural and optical characterizations and numerical simulations of the blue feather barbs of the scarlet macaw. We found that the sponge in the feather barbs is an amorphous diamond-structured photonic crystal with only short-range order. It possesses an isotropic photonic pseudogap that is ultimately responsible for the brilliant noniridescent coloration. We further unravel an ingenious structural optimization for attaining maximum coloration apparently resulting from natural evolution. Upon increasing the material refractive index above the level provided by nature, there is an interesting transition from a photonic pseudogap to a complete bandgap.

Amorphous diamond-structured photonic crystal in the feather barbs of the scarlet macaw

Science.gov (United States)

Yin, Haiwei; Dong, Biqin; Liu, Xiaohan; Zhan, Tianrong; Shi, Lei; Zi, Jian; Yablonovitch, Eli

2012-01-01

Noniridescent coloration by the spongy keratin in parrot feather barbs has fascinated scientists. Nonetheless, its ultimate origin remains as yet unanswered, and a quantitative structural and optical description is still lacking. Here we report on structural and optical characterizations and numerical simulations of the blue feather barbs of the scarlet macaw. We found that the sponge in the feather barbs is an amorphous diamond-structured photonic crystal with only short-range order. It possesses an isotropic photonic pseudogap that is ultimately responsible for the brilliant noniridescent coloration. We further unravel an ingenious structural optimization for attaining maximum coloration apparently resulting from natural evolution. Upon increasing the material refractive index above the level provided by nature, there is an interesting transition from a photonic pseudogap to a complete bandgap. PMID:22615350

Dinosaur evolution. A Jurassic ornithischian dinosaur from Siberia with both feathers and scales.

Science.gov (United States)

Godefroit, Pascal; Sinitsa, Sofia M; Dhouailly, Danielle; Bolotsky, Yuri L; Sizov, Alexander V; McNamara, Maria E; Benton, Michael J; Spagna, Paul

2014-07-25

Middle Jurassic to Early Cretaceous deposits from northeastern China have yielded varied theropod dinosaurs bearing feathers. Filamentous integumentary structures have also been described in ornithischian dinosaurs, but whether these filaments can be regarded as part of the evolutionary lineage toward feathers remains controversial. Here we describe a new basal neornithischian dinosaur from the Jurassic of Siberia with small scales around the distal hindlimb, larger imbricated scales around the tail, monofilaments around the head and the thorax, and more complex featherlike structures around the humerus, the femur, and the tibia. The discovery of these branched integumentary structures outside theropods suggests that featherlike structures coexisted with scales and were potentially widespread among the entire dinosaur clade; feathers may thus have been present in the earliest dinosaurs. Copyright © 2014, American Association for the Advancement of Science.

A Comparative Study of Back Pain among Taxi and Truck Drivers in ...

African Journals Online (AJOL)

Data was analyzed using SSPSS version 20. Descriptive and analytical statistics to analyze and present data. The prevalence of back pain in Port Harcourt for taxi drivers was 70.4% and 71.4% for truck drivers. The prevalence among truck drivers was due to age ,sitting position and shock absorbers. However variables like ...

Artificial insect wings of diverse morphology for flapping-wing micro air vehicles

International Nuclear Information System (INIS)

Shang, J K; Finio, B M; Wood, R J; Combes, S A

2009-01-01

The development of flapping-wing micro air vehicles (MAVs) demands a systematic exploration of the available design space to identify ways in which the unsteady mechanisms governing flapping-wing flight can best be utilized for producing optimal thrust or maneuverability. Mimicking the wing kinematics of biological flight requires examining the potential effects of wing morphology on flight performance, as wings may be specially adapted for flapping flight. For example, insect wings passively deform during flight, leading to instantaneous and potentially unpredictable changes in aerodynamic behavior. Previous studies have postulated various explanations for insect wing complexity, but there lacks a systematic approach for experimentally examining the functional significance of components of wing morphology, and for determining whether or not natural design principles can or should be used for MAVs. In this work, a novel fabrication process to create centimeter-scale wings of great complexity is introduced; via this process, a wing can be fabricated with a large range of desired mechanical and geometric characteristics. We demonstrate the versatility of the process through the creation of planar, insect-like wings with biomimetic venation patterns that approximate the mechanical properties of their natural counterparts under static loads. This process will provide a platform for studies investigating the effects of wing morphology on flight dynamics, which may lead to the design of highly maneuverable and efficient MAVs and insight into the functional morphology of natural wings.

Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling

NARCIS (Netherlands)

Wilts, Bodo D; Michielsen, Kristel; De Raedt, Hans; Stavenga, Doekele G

2014-01-01

Birds-of-paradise are nature's prime examples of the evolution of color by sexual selection. Their brilliant, structurally colored feathers play a principal role in mating displays. The structural coloration of both the occipital and breast feathers of the bird-of-paradise Lawes' parotia is produced

Relation between workplace accidents and the levels of carboxyhemoglobin in motorcycle taxi drivers

Directory of Open Access Journals (Sweden)

Luiz Almeida da Silva

2013-09-01

Full Text Available OBJECTIVE: to investigate the relation between workplace accidents and the levels of carboxyhemoglobin found in motorcycle taxi drivers. METHOD: correlational, quantitative study involving 111 workers and data obtained in July 2012 through a questionnaire to characterize the participants and blood collection to measure carboxyhemoglobin levels. RESULT: 28.8% had suffered workplace accidents; 27.6% had fractured the lower limbs and significant symptoms of carbon monoxide exposure were verified in smokers. The carboxyhemoglobin levels were higher among smokers and victims of workplace accidents. CONCLUSION: motorcycle taxi drivers had increased levels of carboxyhemoglobin, possibly due to the exposure to carbon monoxide; these levels are also increased among smokers and victims of workplace accidents. The study provides advances in the knowledge about occupational health and environmental science, and also shows that carboxyhemoglobin can be an indicator of exposure to environmental pollutants for those working outdoors, which can be related to workplace accidents.

An analytical hierarchical model explaining the robustness and flaw-tolerance of the interlocking barb-barbule structure of bird feathers

Science.gov (United States)

Chen, Qiang; Gorb, Stanislav; Kovalev, Alexander; Li, Zhiyong; Pugno, Nicola

2016-10-01

Feathers can fulfill their aerodynamic function only if the pennaceous vane forms an airfoil stabilized by robust interlocking between barbules. Thus, revealing the robustness of the interlocking mechanical behavior of the barbules is very important to understand the function and long-term resilience of bird feathers. This paper, basing on the small- and large-beam deflection solutions, presents a hierarchical mechanical model for deriving the critical delamination conditions of the interlocking barbules between two adjacent barbs in bird feathers. The results indicate a high robustness and flaw-tolerant design of the structure. This work contributes to the understanding of the mechanical behavior of the robust interlocking barb-barbule structure of the bird feather, and provides a basis for design of feather-inspired materials with robust interlocking mechanism, such as advanced bio-inspired micro-zipping devices.

Kelp gulls Larus dominicanus nest in Antarctica, at subantarctic ...

African Journals Online (AJOL)

spamer

mainly with fledging feathers, but with small amounts of down feathers, taken on 27 January 1993 at Ichaboe. Island, Namibia (26°17′S, 14°56′E). The chicks had dark feathers, with buff fringes on the scapulars, wing coverts and tail, and brown under- parts. That half of the bill nearest the tip was black, the iris dark brown ...

Hidden keys to survival: the type, density, pattern and functional role of emperor penguin body feathers.

Science.gov (United States)

Williams, Cassondra L; Hagelin, Julie C; Kooyman, Gerald L

2015-10-22

Antarctic penguins survive some of the harshest conditions on the planet. Emperor penguins breed on the sea ice where temperatures drop below -40°C and forage in -1.8°C waters. Their ability to maintain 38°C body temperature in these conditions is due in large part to their feathered coat. Penguins have been reported to have the highest contour feather density of any bird, and both filoplumes and plumules (downy feathers) are reported absent in penguins. In studies modelling the heat transfer properties and the potential biomimetic applications of penguin plumage design, the insulative properties of penguin plumage have been attributed to the single afterfeather attached to contour feathers. This attribution of the afterfeather as the sole insulation component has been repeated in subsequent studies. Our results demonstrate the presence of both plumules and filoplumes in the penguin body plumage. The downy plumules are four times denser than afterfeathers and play a key, previously overlooked role in penguin survival. Our study also does not support the report that emperor penguins have the highest contour feather density. © 2015 The Author(s).

Multiple UV reflectance peaks in the iridescent neck feathers of pigeons

Science.gov (United States)

McGraw, Kevin J.

Recent studies of colorful plumage signals in birds have been aided by the finding that birds can see ultraviolet (UV) light and thus may communicate using colors invisible to humans. Some of the pioneering and more pivotal work on avian color vision was performed with domestic pigeons (Columba livia), yet surprisingly there have been few detailed reports of the UV-reflecting properties of pigeon feathers. Here, I use UV-VIS fiber-optic spectrometry to document the full-spectrum reflectance characteristics of iridescent purple and green neck plumage in pigeons. Neck feathers that appear purple to the human eye exhibit four reflectance peaks-two in the UV and one in the blue and red regions-and thus exhibit a UV-purple hue. Neck feathers that appear green to the human eye are characterized by five spectral peaks: two in the UV (UVA and UVB), a predominant green peak, and secondary violet and red peaks, conferring a UV-purple-green color. Such elaborate UV coloration suggests that birds may use an even more complex and `hidden' UV signaling system than previously thought.

Preparation and characterization of sponge film made from feathers.

Science.gov (United States)

Zhuang, Yuan; Wu, Xiaoqian; Cao, Zhangjun; Zhao, Xiaoxiang; Zhou, Meihua; Gao, Pin

2013-12-01

Feather wastes generated from poultry farms will pose a problem for disposal, but they are sustainable resources of keratin. Reduction is one of the commonly used methods to obtain soluble keratin from feather. However, the residues generated during feather reduction reaction were rarely investigated. In this study, the residues were transformed into a porous and flexible sponge film by freeze-drying without pretreatment or addition of cross-linking agents. Glycerol was used to alter the physical and chemical characteristics of the sponge film. The film was characterized with a fiber strong stretch instrument, a Fourier transform infrared spectrophotometer, scanning electron microscopy, an elemental analyzer, a differential scanning calorimeter and an automatic air permeability apparatus. Tensile strength and melting point of the sponge film with the optimum glycerol content were 6.2 MPa and 170°C respectively. Due to air permeability of 368 mm/s, the film can potentially be used in medicine, biology, textile, environmental technology, and so on. It is ecologically friendly and will produce additional benefits from the renewable materials. The film was utilized as adsorbents to remove Cr(VI) from aqueous solutions and as a filtering material for air pollution. Its maximum Cr(VI) uptake capacity was about 148.8 mg/g and the removal rate of PM10 was 98.3%. © 2013.

Viscous-Inviscid Methods in Unsteady Aerodynamic Analysis of Bio-Inspired Morphing Wings

Science.gov (United States)

Dhruv, Akash V.

Flight has been one of the greatest realizations of human imagination, revolutionizing communication and transportation over the years. This has greatly influenced the growth of technology itself, enabling researchers to communicate and share their ideas more effectively, extending the human potential to create more sophisticated systems. While the end product of a sophisticated technology makes our lives easier, its development process presents an array of challenges in itself. In last decade, scientists and engineers have turned towards bio-inspiration to design more efficient and robust aerodynamic systems to enhance the ability of Unmanned Aerial Vehicles (UAVs) to be operated in cluttered environments, where tight maneuverability and controllability are necessary. Effective use of UAVs in domestic airspace will mark the beginning of a new age in communication and transportation. The design of such complex systems necessitates the need for faster and more effective tools to perform preliminary investigations in design, thereby streamlining the design process. This thesis explores the implementation of numerical panel methods for aerodynamic analysis of bio-inspired morphing wings. Numerical panel methods have been one of the earliest forms of computational methods for aerodynamic analysis to be developed. Although the early editions of this method performed only inviscid analysis, the algorithm has matured over the years as a result of contributions made by prominent aerodynamicists. The method discussed in this thesis is influenced by recent advancements in panel methods and incorporates both viscous and inviscid analysis of multi-flap wings. The surface calculation of aerodynamic coefficients makes this method less computationally expensive than traditional Computational Fluid Dynamics (CFD) solvers available, and thus is effective when both speed and accuracy are desired. The morphing wing design, which consists of sequential feather-like flaps installed

Plumas como enfeites da moda Feathers in fashion

Directory of Open Access Journals (Sweden)

Helmut Schindler

2001-01-01

Full Text Available O texto aborda a presença da plumária na moda feminina do século XIX. No Brasil, houve produção de enfeites com penas, que não provinha dos índios. Havia manufaturas que forneciam mercadorias para as lojas da capital. Com base nos relatos de viajantes que passaram pelo Brasil no século XIX, e no material depositado no Museu Estatal de Etnologia de Munique, o autor enfatiza as manufaturas existentes no Brasil e a captura indiscriminada de determinadas espécies de aves para atender a demanda da sociedade da época. Desde o século passado, as aves de penas mais bonitas passam a rarear, o que começa a ser acompanhado pela preocupação com o controle da caça.The article focus on the presence of plumage in the 19th century fashion. In Brazil, the feathers for the production of feather pieces were not necessarily supplied by Indians. There were manufacturers that supplied the stores in the country's capital with these pieces. Based on travelers' reports on nineteenth-century Brazil as well as on material from the State Museum of Ethnology in Munich, the author emphasizes the indiscriminate capture of some species of birds in order to face the demand of society at the time. In the 19th century, the most beautifully-feathered birds progressively began to become rare, which naturally brought forth the concern with uncontrolled bird capture.

The liver taxis of receptor mediated lactosaminated human growth hormone

International Nuclear Information System (INIS)

Chen Zelian; Shi Lin; Li Tongling; Pang Qijie; He Juying; Guan Changtian

2002-01-01

Radiography imaging is used to assess liver taxis mechanism of anti-dwarfism drug lactosaminated human growth hormone (L-rhGH). Both L-rhGH and rhGH labelled with 131 I are used to study their biodistribution in animals (including rabbits, cocks and rats). The results show that L-rhGH is of specific hepatic targeting property, and the maximum hepatic concentration rate is 76.8%, which is two times of rhGH. Its hepatic binding is receptor mediated

Bacterial recovery from breast skin of genetically feathered and featherless broiler carcasses immediately following scalding and picking.

Science.gov (United States)

Buhr, R J; Berrang, M E; Cason, J A

2003-10-01

Genetically feathered and featherless sibling broilers selected for matched BW were killed, scalded, and defeathered to determine the consequences of feathers and empty feather follicles on the recovery of bacteria from carcass breast skin. In trial 1, the vents of all carcasses were plugged and sutured before scalding to prevent the expulsion of cloacal contents during picking. In trial 2, half of the carcasses had their vents plugged and sutured. Immediately after defeathering, breast skin was aseptically removed, and bacteria associated with it were enumerated. In trial 1, the levels of bacteria recovered did not differ between feathered and featherless carcasses: Campylobacter log10 1.4 cfu/mL of rinse, coliform log10 1.8, Escherichia coli log10 1.6, and total aerobic bacteria log10 3.1. In trial 2, the carcasses that had vents plugged and sutured had lower levels of all four types of bacteria (differences of Campylobacter log10 0.7 cfu/mL, coliform log10 1.8, E. coli log10 1.7, and total aerobic bacteria log10 0.5) than those carcasses with open vents. The lower levels of bacteria recovered from carcasses with the vents plugged and sutured during picking enabled detection of small but significant differences between feathered and featherless carcasses. The level of coliform and E. coli recovered was slightly higher by log10 0.7 cfu for feathered carcasses, but featherless carcasses had marginally higher levels of total aerobic bacteria by log10 0.4 cfu. Feathered and featherless carcasses with open vents during picking did not differ in the levels of recovery of coliform, E. coli, and total aerobic bacteria from breast skin.

76 FR 76115 - Revisions to the California State Implementation Plan, Feather River Air Quality Management District

Science.gov (United States)

2011-12-06

... the California State Implementation Plan, Feather River Air Quality Management District AGENCY... limited disapproval of revisions to the Feather River Air Quality Management District (FRAQMD) portion of..., Regulatory Planning and Review The Office of Management and Budget (OMB) has exempted this regulatory action...

Purification and characterization of a keratinase from the feather ...

African Journals Online (AJOL)

Yomi

2012-01-31

Jan 31, 2012 ... Keratinase was purified and characterized from the solid cultures of ... Feather from the poultry processing plant is the common source ... keratinous wastes by proteolytic enzymes is a potent ... After treatment with keratinase,.

Heritability of feather pecking and open-field response of laying hens at two different ages

NARCIS (Netherlands)

Rodenburg, T.B.; Buitenhuis, A.J.; Ask, B.; Uitdehaag, K.A.; Koene, P.; Poel, van der J.J.; Bovenhuis, H.

2003-01-01

The objective of the current study was to estimate heritabilities. (h(2)) of feather pecking and open-field response of laying hens at two different ages. An F-2 cross, originating from a high and a low feather pecking line of laying hens, was used for the experiment. Each of the 630 birds of the

Using Pb-Al ratios to discriminate between internal and external deposition of Pb in feathers.

Science.gov (United States)

Cardiel, Iris E; Taggart, Mark A; Mateo, Rafael

2011-05-01

Feathers provide a potentially useful biomonitoring option in studies regarding pollution exposure in avian species. However, they must be used with care because the complex, fine structure is highly prone to accumulating surface contamination. This may therefore give a misleading indication of pollutant intake in the animal. Here, data are presented for 4 large scavenging raptor species collected in Spain, and analyses are undertaken on feather barbs and rachis for both Pb and Al concentrations. Aluminium levels are used as a marker of surface contamination by inorganic particulate material. Despite using a thorough washing technique, feather barbs showed significantly higher levels of Pb than did the rachis for all 4 species studied. We also observed a significant correlation (r=0.782, pbarbs, whilst rachis Al levels were below our detection limit in all samples analysed. Results indicate that the rachis would provide more representative data as regards Pb (or other heavy metal) uptake and tissue deposition within bird tissues during the period of feather growth. As such, data would be more toxicologically relevant. Copyright © 2011 Elsevier Inc. All rights reserved.

Taking actions to quit chewing betel nuts and starting a new life: taxi drivers' successful experiences of quitting betel nut chewing.

Science.gov (United States)

Yang, Tsui-Yun; Lin, Hung-Ru

2017-04-01

To understand taxi drivers' successful experiences of quitting betel nut chewing. Previous studies verified that betel nut chewing significantly increases the risk of oral cancer. In Taiwan, taxi drivers work for approximately 10-13 hours per day, and 31·7-80% of them choose to chew betel nuts for their invigorating qualities, which enable them to work more hours and receive more income. A qualitative research design was used. This study used the grounded theory method with purposive sampling to perform in-depth interviews with male taxi drivers who had successfully quit betel nut chewing for more than six months. The interviewed participants were 25 taxi drivers aged 45-67 who had chewed betel nuts for an average of 30·9 years. A constant comparative analysis of the 25 interviews revealed six categories, namely the first experience of chewing betel nuts, a part of work and life, perceiving the impact of betel nuts, trying to change, acting to quit betel nut chewing and starting a new life. During the cessation process, taxi drivers tended to be affected by their addiction to chewing betel nuts and the temptation of friends' invitations to chew betel nuts. However, their recognition of the physical effects of betel nut chewing and their sense of responsibility and commitment to family were the critical factors affecting their determination to quit betel nut chewing. Their willpower to not to chew betel nuts and the source of their motivation to exercise self-control also contributed to their success. Healthcare personnel should understand the experiences and perceptions of betel nut chewers, strengthen their understanding of the effects of betel nut chewing on physical health during the cessation period and support their self-efficacy and quitting behaviours with the assistance of significant others. © 2016 John Wiley & Sons Ltd.

A cross-sectional study with an improved methodology to assess occupational air pollution exposure and respiratory health in motorcycle taxi driving

International Nuclear Information System (INIS)

Lawin, Herve; Agodokpessi, Gildas; Ayelo, Paul; Kagima, Jacqueline; Sonoukon, Rodrigue; Mbatchou Ngahane, Bertrand H.; Awopeju, Olayemi; Vollmer, William M.; Nemery, Benoit; Burney, Peter; Fayomi, Benjamin

2016-01-01

Introduction: Motorcycle taxi driving is common in many African cities. This study tested whether this occupation is associated with more respiratory disorders in a context of widespread urban air pollution with an improved methodology. Methods: In a cross sectional study we compared 85 male motorcycle taxi drivers in the capital city of the Republic of Benin (Cotonou) with an age and neighborhood matched control group. All participants carried a portable carbon monoxide data logger for 8 hours per day to assess exposure to air pollution. Respiratory symptoms were obtained using a standardized questionnaire and pulmonary function was assessed by spirometry. Results: The two groups did not differ significantly (p > 0.10) in their age, height, educational level, and exposures to smoke from biomass fuels and tobacco products. The taxi drivers were exposed to higher mean (SD) levels of carbon monoxide (7.6 ± 4.9 ppmvs. 5.4 ± 3.8 ppm p = 0.001). They reported more phlegm and tended to have slightly lower levels of lung function, although these differences were not statistically significant. Conclusion: In this cross sectional study of young motorcycle taxi drivers with substantial exposure to urban traffic and a matched control group, we found no evidence for respiratory impairment. A follow-up of such study population with other pollution exposure surrogate and other clinical endpoint may provide a more robust conclusion regarding the exposure response in this professional group. - Highlights: • Need of improved study method to assess air pollution effect in exposed workers • This study compared motorcycle taxi drivers and a matched control group • Personal carbon monoxide exposure and respiratory disorders were collected • No evidence of more respiratory disorders even though pollutant exposure was higher

A cross-sectional study with an improved methodology to assess occupational air pollution exposure and respiratory health in motorcycle taxi driving

Energy Technology Data Exchange (ETDEWEB)

Lawin, Herve, E-mail: hervelawin@yahoo.fr [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin); Agodokpessi, Gildas [Centre National Hospitalier et Universitaire de Pneumo-Phtisiologie, Cotonou (Benin); Ayelo, Paul [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin); Kagima, Jacqueline [Department of internal medicine, Egerton University (Kenya); Sonoukon, Rodrigue [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin); Mbatchou Ngahane, Bertrand H. [Department of Internal Medicine, Douala General Hospital, Cameroon Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala (Cameroon); Awopeju, Olayemi [Department of Medicine, Obafemi Awolowo University, Ile Ife (Nigeria); Vollmer, William M. [Center for Health Research, Kaiser Permanente Northwest, Portland (United States); Nemery, Benoit [Dept. of Public Health, Occupational and Environmental Insurance Medicine, KU Leuven, Leuven (Belgium); Burney, Peter [National Heart & Lung Institute, Imperial College, London (United Kingdom); Fayomi, Benjamin [Unit of Teaching and Research in Occupational and Environmental Health, Department of Public Health, Faculty of Health Sciences, University of Abomey-Calavi (Benin)

2016-04-15

Introduction: Motorcycle taxi driving is common in many African cities. This study tested whether this occupation is associated with more respiratory disorders in a context of widespread urban air pollution with an improved methodology. Methods: In a cross sectional study we compared 85 male motorcycle taxi drivers in the capital city of the Republic of Benin (Cotonou) with an age and neighborhood matched control group. All participants carried a portable carbon monoxide data logger for 8 hours per day to assess exposure to air pollution. Respiratory symptoms were obtained using a standardized questionnaire and pulmonary function was assessed by spirometry. Results: The two groups did not differ significantly (p > 0.10) in their age, height, educational level, and exposures to smoke from biomass fuels and tobacco products. The taxi drivers were exposed to higher mean (SD) levels of carbon monoxide (7.6 ± 4.9 ppmvs. 5.4 ± 3.8 ppm p = 0.001). They reported more phlegm and tended to have slightly lower levels of lung function, although these differences were not statistically significant. Conclusion: In this cross sectional study of young motorcycle taxi drivers with substantial exposure to urban traffic and a matched control group, we found no evidence for respiratory impairment. A follow-up of such study population with other pollution exposure surrogate and other clinical endpoint may provide a more robust conclusion regarding the exposure response in this professional group. - Highlights: • Need of improved study method to assess air pollution effect in exposed workers • This study compared motorcycle taxi drivers and a matched control group • Personal carbon monoxide exposure and respiratory disorders were collected • No evidence of more respiratory disorders even though pollutant exposure was higher.

Keratin homogeneity in the tail feathers of Pavo cristatus and Pavo cristatus mut. alba.

Science.gov (United States)

Pabisch, S; Puchegger, S; Kirchner, H O K; Weiss, I M; Peterlik, H

2010-12-01

The keratin structure in the cortex of peacocks' feathers is studied by X-ray diffraction along the feather, from the calamus to the tip. It changes considerably over the first 5 cm close to the calamus and remains constant for about 1m along the length of the feather. Close to the tip, the structure loses its high degree of order. We attribute the X-ray patterns to a shrinkage of a cylindrical arrangement of β-sheets, which is not fully formed initially. In the final structure, the crystalline beta-cores are fixed by the rest of the keratin molecule. The hydrophobic residues of the beta-core are locked into a zip-like arrangement. Structurally there is no difference between the blue and the white bird. Copyright © 2010 Elsevier Inc. All rights reserved.

A Feasibility Test on Adopting Electric Vehicles to Serve as Taxis in Daejeon Metropolitan City of South Korea

Directory of Open Access Journals (Sweden)

Seoin Baek

2016-09-01

Full Text Available For realizing sustainable development, EV (Electric Vehicle is currently considered as one of the most promising alternative due to its cleanness and inexhaustibility. However, the development and dissemination of EV has stagnated because it faces major constraints such as battery performance and an excessively long charging time. Thus, this study examined the feasibility of using EVs as taxis by analyzing real data from a pilot project in Daejeon, a metropolitan city in South Korea for proposing the effective way to adopt EV. To reflect reality and improve accuracy, we adopted scenarios and assumptions based on in-depth interviews with groups of experts. The resulting initial benefit-to-cost (B/C ratio for EV taxis is approximately 0.4, which is quite low compared to 0.7 for traditional taxis. However, after incorporating some further assumptions into the calculation, the B/C ratio shifts to approximately 0.7, which is more appropriate for EV adoption. For this improvement to be achieved, the dissemination of a charging infrastructure, improvement of the business model and policy support is strongly needed. Limitations to this work and potential areas for future study are also fully discussed.

Colour-producing [beta]-keratin nanofibres in blue penguin (Eudyptula minor) feathers

Energy Technology Data Exchange (ETDEWEB)

D; Alba, Liliana; Saranathan, Vinodkumar; Clarke, Julia A.; Vinther, Jakob A.; Prum, Richard O.; Shawkey, Matthew D. (Yale); (Akron); (Texas)

2012-03-26

The colours of living organisms are produced by the differential absorption of light by pigments (e.g. carotenoids, melanins) and/or by the physical interactions of light with biological nanostructures, referred to as structural colours. Only two fundamental morphologies of non-iridescent nanostructures are known in feathers, and recent work has proposed that they self-assemble by intracellular phase separation processes. Here, we report a new biophotonic nanostructure in the non-iridescent blue feather barbs of blue penguins (Eudyptula minor) composed of parallel {beta}-keratin nanofibres organized into densely packed bundles. Synchrotron small angle X-ray scattering and two-dimensional Fourier analysis of electron micrographs of the barb nanostructure revealed short-range order in the organization of fibres at the appropriate size scale needed to produce the observed colour by coherent scattering. These two-dimensional quasi-ordered penguin nanostructures are convergent with similar arrays of parallel collagen fibres in avian and mammalian skin, but constitute a novel morphology for feathers. The identification of a new class of {beta}-keratin nanostructures adds significantly to the known mechanisms of colour production in birds and suggests additional complexity in their self-assembly.

Colour-producing β-keratin nanofibres in blue penguin (Eudyptula minor) feathers

Science.gov (United States)

D'Alba, Liliana; Saranathan, Vinodkumar; Clarke, Julia A.; Vinther, Jakob A.; Prum, Richard O.; Shawkey, Matthew D.

2011-01-01

The colours of living organisms are produced by the differential absorption of light by pigments (e.g. carotenoids, melanins) and/or by the physical interactions of light with biological nanostructures, referred to as structural colours. Only two fundamental morphologies of non-iridescent nanostructures are known in feathers, and recent work has proposed that they self-assemble by intracellular phase separation processes. Here, we report a new biophotonic nanostructure in the non-iridescent blue feather barbs of blue penguins (Eudyptula minor) composed of parallel β-keratin nanofibres organized into densely packed bundles. Synchrotron small angle X-ray scattering and two-dimensional Fourier analysis of electron micrographs of the barb nanostructure revealed short-range order in the organization of fibres at the appropriate size scale needed to produce the observed colour by coherent scattering. These two-dimensional quasi-ordered penguin nanostructures are convergent with similar arrays of parallel collagen fibres in avian and mammalian skin, but constitute a novel morphology for feathers. The identification of a new class of β-keratin nanostructures adds significantly to the known mechanisms of colour production in birds and suggests additional complexity in their self-assembly. PMID:21307042

Kinetics and substrate selectivity of a Triticum aestivum xylanase inhibitor (TAXI) resistant D11F/R122D variant of Bacillus subtilis XynA xylanase

DEFF Research Database (Denmark)

Rasmussen, Louise Enggaard; Sørensen, Jens F.; Meyer, Anne S.

2010-01-01

This study examined the kinetics and substrate selectivity of a GH11 Bacillus subtilis XynA xylanase (BsX) sensitive to inhibition by TAXI and an engineered variant, which is much less inhibited by TAXI (BsX(mut)). The main purpose of the work was to elucidate any influence of the structural point...

Operations of electric taxis to serve advance reservations by trip chaining: Sensitivity analysis on network size, customer demand and number of charging stations

Directory of Open Access Journals (Sweden)

Hao Wang

2016-10-01

Full Text Available This research investigated the performance of an Electric Taxi (ET fleet that catered solely for customers with advance reservations. In a previously related research, a customized Paired Pickup and Delivery Problem with Time Window and Charging Station (PPDPTWCS had been formulated to solve for the minimum number of taxis that would serve a fixed set of customer demand. The concept behind this fleet optimization was to chain multiple customer trips and trips to Charging Stations (CSs to form a route and assigned to a taxi driver. In this paper the sensitivity of the ET fleet’s operations with respect to network sizes, customer demand densities and number of CSs have been investigated. It also analyzed the market shares of the CSs and the occupancy of a CS over time. The results showed that, (1 the expansion of network size or the increase in customer demand density led to increase in fleet size, number of trips to the CSs and maximum occupancies at the CSs but these performance measures grew at different rates; (2 when the network size and number of CSs were fixed, an increase in customer demand density led to a better utilization of taxis in terms of more customers served per taxi and higher average revenue per taxi; (3 given the same network size and demand density, the ET fleet’s performance was relatively insensitive to the number of CSs; and (4 the usage of individual CS was affected by the number of CS and their locations; and (5 when all the ETs were fully charged at the beginning of the same shift hour, they visited the CSs in bunches when their batteries were about to run out. These findings contribute to a better understanding of the operations of the ET fleet and the CSs. They could be used for making better decisions in the planning of ET operations.

Novel four-wing and eight-wing attractors using coupled chaotic Lorenz systems

International Nuclear Information System (INIS)

Grassi, Giuseppe

2008-01-01

This paper presents the problem of generating four-wing (eight-wing) chaotic attractors. The adopted method consists in suitably coupling two (three) identical Lorenz systems. In analogy with the original Lorenz system, where the two wings of the butterfly attractor are located around the two equilibria with the unstable pair of complex-conjugate eigenvalues, this paper shows that the four wings (eight wings) of these novel attractors are located around the four (eight) equilibria with two (three) pairs of unstable complex-conjugate eigenvalues. (general)

50 CFR 20.91 - Commercial use of feathers.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Commercial use of feathers. 20.91 Section 20.91 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR.... Any person may possess, purchase, sell, barter, or transport for the making of fishing flies, bed...

Decomposition of intact chicken feathers by a thermophile in combination with an acidulocomposting garbage-treatment process.

Science.gov (United States)

Shigeri, Yasushi; Matsui, Tatsunobu; Watanabe, Kunihiko

2009-11-01

In order to develop a practical method for the decomposition of intact chicken feathers, a moderate thermophile strain, Meiothermus ruber H328, having strong keratinolytic activity, was used in a bio-type garbage-treatment machine working with an acidulocomposting process. The addition of strain H328 cells (15 g) combined with acidulocomposting in the garbage machine resulted in 70% degradation of intact chicken feathers (30 g) within 14 d. This degradation efficiency is comparable to a previous result employing the strain as a single bacterium in flask culture, and it indicates that strain H328 can promote intact feather degradation activity in a garbage machine currently on the market.

PENINGKATAN HASIL BELAJAR PERPAJAKAN MELALUI MEDIA TAXI SNADERS PADA SISWA XI B SMK PL TARCISIUS 2

Directory of Open Access Journals (Sweden)

Cornelius Hery Setyawan

2016-01-01

Full Text Available Vocational School (SMK is an educational institution to transfer knowledge about the tax. Unluckily, teaching learning process in delivering this material was monotonous, so it needed a medium called TAXI SNADERS. The objective of the study was to increase interest and learning outcomes taxation on Value Added Tax (VAT and Sales of Luxury through a medium called TAXI SNADERS. The result of the study showed that there was improvement toward students’ interest for 14.5%. On the 1st cycle, students’ interest was only 67.25%, then it increased up to 81.75% on the 2nd cycle. Moreover, students’ learning outcomes also increased for 20% in post test. It was 67% on the 1st cycle and rose to 87% on the 2nd cycle. 

Hair and feathers as indicator of internal contamination of 210Po and 210Pb

Energy Technology Data Exchange (ETDEWEB)

Holm, E. (ed.); Gwynn, J.; Zaborska, A.; Gaefvert, T. (Norwegian Radiation Protection Authority (Norway)); Roos, P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Henricsson, F. (Lund Univ., Lund (Sweden))

2010-03-15

The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210Po. Human hair from people of different sex and age was analysed for 210Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210Po and 210Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

Hair and feathers as indicator of internal contamination of 210Po and 210Pb

International Nuclear Information System (INIS)

Holm, E.; Roos, P.; Henricsson, F.

2010-03-01

The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210 Po. Human hair from people of different sex and age was analysed for 210 Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210 Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210 Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210 Po and 210 Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

Shrimp pond wastewater treatment using pyrolyzed chicken feather as adsorbent

Science.gov (United States)

Moon, Wei Chek; Jbara, Mohamad Hasan; Palaniandy, Puganeshwary; Yusoff, Mohd Suffian

2017-10-01

In this study, chicken feather fiber was used as a raw material to prepare a non-expensive adsorbent by pyrolysis without chemical activation. The main pollutants treated in this study were chemical oxygen demand (COD) and ammoniacal nitrogen (NH3-N) from shrimp pond wastewater containing high concentrations of nutrients, which caused the eutrophication phenomenon in adjacent water. Batch adsorption studies were performed to investigate the effect of pH (5-8), mass of adsorbent (0.5-3 g), and shaking time (0.5-2 h) on the removal efficiency of COD and NH3- N. Experimental results showed that the optimum conditions were as follows: pH 5, 0.5 g of adsorbent, and 0.5 h of shaking. Under these conditions, 34.01% and 40.47% of COD and NH3-N were removed, respectively, from shrimp pond wastewater. The adsorption processes were best described by the Langmuir isotherm model for COD and NH3-N removal, with maximum monolayer adsorption capacity of 36.9 and 7.24 mg/g for COD and NH3-N, respectively. The results proved that chicken feather could remove COD and NH3-N from shrimp pond wastewater. However, further studies on thermal treatment should be carried out to increase the removal efficiency of pyrolyzed chicken feather fiber.

Quad-thopter: Tailless Flapping Wing Robot with 4 Pairs of Wings

NARCIS (Netherlands)

de Wagter, C.; Karasek, M.; de Croon, G.C.H.E.; J.-M. Moschetta G. Hattenberger, H. de Plinval

2017-01-01

We present a novel design of a tailless flapping wing Micro Air Vehicle (MAV), which uses four independently driven pairs of flapping wings in order to fly and perform agile maneuvers. The wing pairs are arranged such that differential thrust generates the desired roll and pitch moments, similar to

Cell structure of developing barbs and barbules in downfeathers of the chick: Central role of barb ridge morphogenesis for the evolution of feathers.

Science.gov (United States)

Alibardi, L

2005-04-01

The present ultrastructural study shows how cells organize to form the complex structure of downfeathers in chick embryos. The embryonic epidermis of the apical part of feather filaments folds inward forming barb ridges which extend toward the base of the feather. The stratification of epidermal cells in barb ridges is maintained but the basal layer loses most of the germinal activity. New cells for the growth of feather filaments are mainly produced in its basal part. In barb ridges only the original four epidermal layers of the embryonic epidermis remain to form feathers: 1) the external periderm, 2) three-five layers of the feather sheath and barb vane ridge cells, 3) subperiderm cells, and 4) basal or cylindrical cells. Periderm, sheath, barb vane ridge and cylindrical cells synthesize only alpha-keratin. Instead, cells of the subperiderm layer synthesize a small type of beta-keratin: feather beta-keratin. At hatching, the subperiderm layer is lost in most areas of the skin of the chick (apteric and scaled), and is replaced by cells containing alpha-keratin (interfollicular-apteric epidermis), scale beta-keratin (scales), beak beta-keratin (beak), and claw beta-keratin (claws). Only in feathers, cells of the original subperiderm layer remain and give origin to barb and barbule cells. The formation of separated chains of barb and barbule cells is allowed by the presence of barb vane ridge cells that function as spacers between merging cells of barb and barbule cells. Subperiderm cells elongate and merge into a syncitium to form barbules and barbs. While barbule and barb cells accumulate feather-keratin, barb vane and cylindrical cells accumulate lipids, vesicles and little alpha-keratin. These cells eventually degenerate by necrosis leaving empty spaces and lipids between barbules and barbs. No apoptosis is necessary to explain the process of carving out of barb and barbules in feathers after dissolution of the external sheath. In fact, the retraction of blood

Feather conditions and clinical scores as indicators of broilers welfare at the slaughterhouse.

Science.gov (United States)

Saraiva, S; Saraiva, C; Stilwell, G

2016-08-01

The objective of this study was to evaluate the welfare of 64 different broiler farms on the basis of feather conditions and clinical scores measures collected at the slaughterhouse. A 3-point scale (0, 1 or 2) was used to classify dirty feathers, footpad dermatitis and hock burns measures, and a 2-point scale (present or absent) was used to classify breast burns, breast blisters and breast ulcer measures. Flocks were allocated into three body weight (BW) classes (A, B, C): class A (light) ≥1.43 and ≤1.68kg, class B (medium) ≥1.69 and ≤1.93kg; class C (heavy) ≥1.94 and ≤2.41kg. The absence of hock burns was more common in class A, while mild hock burns was more common in class B flocks. Breast ulcer was observed in class C flocks. The association observed for mild hock burns, breast burns and severe footpad dermatitis can indicate a simultaneous occurrence of these painful lesions. Very dirty feathers and severe footpad dermatitis relationship suggest litter humidity to be the common underlying cause. In conclusion, it was shown that clinical indicators can be used at the slaughterhouse to identify welfare problems. In the studied flocks, footpad dermatitis, feather conditions and hock burns were the main restrictions for good welfare and should be considered significant welfare indicators of the on-farm rearing conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

TrajGraph: A Graph-Based Visual Analytics Approach to Studying Urban Network Centralities Using Taxi Trajectory Data.

Science.gov (United States)

Huang, Xiaoke; Zhao, Ye; Yang, Jing; Zhang, Chong; Ma, Chao; Ye, Xinyue

2016-01-01

We propose TrajGraph, a new visual analytics method, for studying urban mobility patterns by integrating graph modeling and visual analysis with taxi trajectory data. A special graph is created to store and manifest real traffic information recorded by taxi trajectories over city streets. It conveys urban transportation dynamics which can be discovered by applying graph analysis algorithms. To support interactive, multiscale visual analytics, a graph partitioning algorithm is applied to create region-level graphs which have smaller size than the original street-level graph. Graph centralities, including Pagerank and betweenness, are computed to characterize the time-varying importance of different urban regions. The centralities are visualized by three coordinated views including a node-link graph view, a map view and a temporal information view. Users can interactively examine the importance of streets to discover and assess city traffic patterns. We have implemented a fully working prototype of this approach and evaluated it using massive taxi trajectories of Shenzhen, China. TrajGraph's capability in revealing the importance of city streets was evaluated by comparing the calculated centralities with the subjective evaluations from a group of drivers in Shenzhen. Feedback from a domain expert was collected. The effectiveness of the visual interface was evaluated through a formal user study. We also present several examples and a case study to demonstrate the usefulness of TrajGraph in urban transportation analysis.

Taxi drivers' views on risky driving behavior in Tehran: a qualitative study using a social marketing approach.

Science.gov (United States)

Shams, Mohsen; Shojaeizadeh, Davoud; Majdzadeh, Reza; Rashidian, Arash; Montazeri, Ali

2011-05-01

The use of the social marketing approach for public health issues is increasing. This approach uses marketing concepts borrowed from the principles of commercial marketing to promote beneficial health behaviors. In this qualitative study, four focus groups involving 42 participants were used in consumer research to explore taxi drivers' views on the driving situation and the determinants of risky driving behaviors in Tehran, as well as to gather their ideas for developing a social marketing program to reduce risky driving behaviors among taxi drivers in Tehran, Iran. Participants were asked to respond to questions that would guide the development of a marketing mix, or four Ps (product, price, place and promotion). The discussions determined that the program product should involve avoiding risky driving behaviors through increased attention to driving. They pointed out that developing and communicating with a well-designed persuasive message meant to draw their attention to driving could affect their driving behaviors. In addition, participants identified price, place and promotion strategies. They offered suggestions for marketing nonrisky driving to the target audience. The focus group discussions generated important insights into the values and the motivations that affect consumers' decisions to adopt the product. The focus group guided the development of a social marketing program to reduce risky driving behaviors in taxi drivers in Tehran, Iran. Copyright © 2010 Elsevier Ltd. All rights reserved.

Digital collaborative consumption and social issues: The clash of taxi and Uber driver in Surabaya and Taipei

Directory of Open Access Journals (Sweden)

Kholifatus Saadah

2017-12-01

Full Text Available Since the occurrence of application-based taxi, phenomenon and resistance have emerged in metropolitan cities around the world. One of the main issues highlighted is digital collaborative consumption which emerges as the consequences of globalization. As an interpretive case study research, this paper aims to analyze the use of Uber as an alternative to public transportation in Taipei and Surabaya. Authors discuss the issue by comparing the reaction toward the occurrence of Uber and Taipei and Surabaya. Authors apply the theory from Hegre, Gissinger, & Gledtisch (2002 about globalization and social conflict to explain social issues as the consequences of digital collaborative consumption as the new consumption model. According to the theory, globalization creates a deprivation which makes the struggle to access source of capital become more intense. Poverty is the main generator of radical action and violence. Analyzing the phenomena of Uber usage and the resistance from traditional taxi businessmen in Taipei and Surabaya, the authors argue that globalization reflected on digital collaborative consumption could lead to social unrest for parties who cannot adapt to the changes in economic practice. As shown by many cases of app-based rejection taxi in public places such as airport, train station and bus station; the traditionalists show resistance towards globalization and the economic shift of public transportation business model.

Aspergillus prevalence in air conditioning filters from vehicles: taxis for patient transportation, forklifts, and personal vehicles.

Science.gov (United States)

Viegas, Carla; Moreira, Ricardo; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Gomes, Anita Quintal; Viegas, Susana

2018-05-04

The frequency and importance of Aspergillus infections is increasing worldwide. This study aimed to assess the occupational exposure of forklifts and taxi drivers to Aspergillus spp. Nineteen filters from air conditioning system of taxis, 17 from forklifts and 37 from personal vehicles were assessed. Filters extract were streaked onto MEA, DG18 and in azole-supplemented media. Real-time quantitative PCR amplification of selected Aspergillus species-complex was also performed. Forklifts filter samples presented higher median values. Aspergillus section Nigri was the most observed in forklifts filters in MEA (28.2%) and in azole-supplemented media. DNA from Aspergillus sections Fumigati and Versicolores was successfully amplified by qPCR. This study enlightens the added value of using filters from the air conditioning system to assess Aspergillus spp. occupational exposure. Aspergillus azole resistance screening should be included in future occupational exposure assessments.

Reply to: “A response to some unwarranted criticisms of single-grain dating” by J.K. Feathers

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, Andrew Sean; Buylaert, Jan-Pieter

2017-01-01

In the note “A response to some unwarranted criticisms of single-grain dating” Feathers raises many issues with both the approach and the conclusions of Thomsen et al. (2016). After careful consideration, we find we disagree with Feather's analysis and conclusions, and stand by the original concl...

Prevalence and factors associated with road traffic crash among taxi drivers in Mekelle town, northern Ethiopia, 2014: a cross sectional study.

Directory of Open Access Journals (Sweden)

Nigus Gebremedhin Asefa

Full Text Available The 2013 World Health Organization Status Report on Road Safety estimated that approximately 1.24 million deaths occur annually due to road traffic crashes with most of the burden falling on low- and middle-income countries. The objective of this research is to study the prevalence of road traffic crashes in Mekelle, Tigray, Northern Ethiopia and to identify risk factors with the ultimate goal of informing prevention activities and policies.This study used a cross-sectional design to measure the prevalence and factors associated with road traffic crashes among 4-wheeled minibus (n = 130 and 3-wheeled Bajaj (n = 582 taxi drivers in Mekelle, Ethiopia. Bivariate and multivariate logistic regression were used to evaluate the association between risk factors and drivers' involvement in a road traffic crash within the 3 years prior to the survey.Among the 712 taxi drivers, 26.4% (n = 188 of them reported involvement in a road traffic crash within the past 3 years. Drivers who listened to mass media had decreased likelihood of road traffic crash involvement (AOR = 0.51, 0.33-0.78, while speedy driving (AOR = 4.57, 3.05-7.44, receipt of a prior traffic punishment (AOR = 4.57, 2.67-7.85, and driving a mechanically faulty taxi (AOR = 4.91, 2.81-8.61 were strongly associated with road traffic crash involvement. Receiving mobile phone calls while driving (AOR = 1.91, 1.24-2.92 and history of alcohol use (AOR = 1.51, 1.00-2.28 were also associated with higher odds of road traffic crash involvement.The results of this study show that taxi drivers in Mekelle habitually place themselves at increased risk of road traffic crashes by violating traffic laws, especially related to speedy driving, mobile phone use, and taxi maintenance. This research can be used to support re-evaluation of the type, severity, and enforcement of traffic violation penalties.

An alternate and reversible method for flight restraint of cranes.

Science.gov (United States)

Zhang, Sen Lin; Yang, Shu Hui; Li, Bing; Xu, Yan Chun; Ma, Jian Hua; Xu, Jian Feng; Zhang, Xian Guang

2011-01-01

Flight restraint is important for zoos, safaris, and breeding centers for large birds. Currently used techniques for flight restraint include both surgical and non-surgical approaches. Surgical approaches usually cause permanent change to or removal of tendon, patagial membrane, or wing bones, and can cause pain and inflammation. Non-surgical approaches such as clipping or trimming feathers often alter the bird's appearance, and can damage growing blood feathers in fledglings or cause joint stiffness. We observed microstructure of primary feathers of the red-crowned crane (Grus japonensis) and found that the width of barbs is a determinative factor influencing vane stiffness and geometric parameters. We hypothesized that partial longitudinal excision of barbs on the ventral surface of the primary feathers would reduce the stiffness of the vane and render the feathers unable to support the crane's body weight during flight. Furthermore, we hypothesized that this modification of barbs would also change the aerodynamic performance of feathers such that they could not generate sufficient lift and thrust during flapping to enable the bird to fly. We tested this hypothesis on a red-crowned crane that had normal flight capability by excising the ventral margin of barbs on all 10 primaries on the left wing. The bird was unable to take off until the modified feathers were replaced by new ones. Removal of barbs proved to be a simple, non-invasive, low-cost and reversible method for flight restraint. It is potentially applicable to other large birds with similar structural characteristics of primary feathers. © 2010 Wiley-Liss, Inc.

Feather wastes digestion by new isolated strains Bacillus sp. in ...

African Journals Online (AJOL)

Feather wastes digestion by new isolated strains Bacillus sp. in Morocco. ... The most efficient isolated strain selected was compared with Bacillus subtilis ATCC 6633. Results showed ... African Journal of Biotechnology Vol.3(1) 2004: 67-70 ...

Mining Open Datasets for Transparency in Taxi Transport in Metropolitan Environments

OpenAIRE

Noulas, Anastasios; Salnikov, Vsevolod; Lambiotte, Renaud; Mascolo, Cecilia

2015-01-01

Uber has recently been introducing novel practices in urban taxi transport. Journey prices can change dynamically in almost real time and also vary geographically from one area to another in a city, a strategy known as surge pricing. In this paper, we explore the power of the new generation of open datasets towards understanding the impact of the new disruption technologies that emerge in the area of public transport. With our primary goal being a more transparent economic landscape for urban...

Melanosome evolution indicates a key physiological shift within feathered dinosaurs.

Science.gov (United States)

Li, Quanguo; Clarke, Julia A; Gao, Ke-Qin; Zhou, Chang-Fu; Meng, Qingjin; Li, Daliang; D'Alba, Liliana; Shawkey, Matthew D

2014-03-20

Inference of colour patterning in extinct dinosaurs has been based on the relationship between the morphology of melanin-containing organelles (melanosomes) and colour in extant bird feathers. When this relationship evolved relative to the origin of feathers and other novel integumentary structures, such as hair and filamentous body covering in extinct archosaurs, has not been evaluated. Here we sample melanosomes from the integument of 181 extant amniote taxa and 13 lizard, turtle, dinosaur and pterosaur fossils from the Upper-Jurassic and Lower-Cretaceous of China. We find that in the lineage leading to birds, the observed increase in the diversity of melanosome morphologies appears abruptly, near the origin of pinnate feathers in maniraptoran dinosaurs. Similarly, mammals show an increased diversity of melanosome form compared to all ectothermic amniotes. In these two clades, mammals and maniraptoran dinosaurs including birds, melanosome form and colour are linked and colour reconstruction may be possible. By contrast, melanosomes in lizard, turtle and crocodilian skin, as well as the archosaurian filamentous body coverings (dinosaur 'protofeathers' and pterosaur 'pycnofibres'), show a limited diversity of form that is uncorrelated with colour in extant taxa. These patterns may be explained by convergent changes in the key melanocortin system of mammals and birds, which is known to affect pleiotropically both melanin-based colouration and energetic processes such as metabolic rate in vertebrates, and may therefore support a significant physiological shift in maniraptoran dinosaurs.

Feather-picking psittacines: histopathology and species trends.

Science.gov (United States)

Garner, M M; Clubb, S L; Mitchell, M A; Brown, L

2008-05-01

Histologic findings are described for 408 feather-picking or self-mutilating psittacines with the use of biopsies from clinically affected and unaffected skin. Inflammatory skin disease was diagnosed in 210 birds, and traumatic skin disease was diagnosed in 198 birds. Criteria used for the diagnosis of inflammatory skin disease included the presence of perivascular inflammation in the superficial or deep dermis of clinically affected and unaffected sites. The primary histologic criteria for the diagnosis of traumatic skin disease were superficial dermal scarring with or without inflammation in the affected sites and an absence of inflammation in the unaffected sites. The inflammatory cells associated with the lesions were typically lymphocytes and occasionally plasma cells, histiocytes, and granulocytes. A preponderance of inflammatory skin disease was seen in macaws (Ara spp.) and Amazon parrots (Amazona spp.). A preponderance of traumatic skin disease was seen in cockatoos (Cacatua spp.) and African grey parrots (Psittacus erithacus). The prevalence of each was approximately equal in several other species, including conures (Aratinga and Pyrrhura spp.), eclectus parrots (Eclectus roratus), quaker parrots (Myiopsitta monachus), cockatiels (Nymphicus hollandicus), parakeets (Cyanorhamphus and Psittacula spp.), and caiques (Pionites spp.). No geographic or gender-based trends were identified. These findings could be helpful for identifying and treating birds with feather-picking disorders.

Aerodynamic comparison of a butterfly-like flapping wing-body model and a revolving-wing model

Science.gov (United States)

Suzuki, Kosuke; Yoshino, Masato

2017-06-01

The aerodynamic performance of flapping- and revolving-wing models is investigated by numerical simulations based on an immersed boundary-lattice Boltzmann method. As wing models, we use (i) a butterfly-like model with a body and flapping-rectangular wings and (ii) a revolving-wing model with the same wings as the flapping case. Firstly, we calculate aerodynamic performance factors such as the lift force, the power, and the power loading of the two models for Reynolds numbers in the range of 50-1000. For the flapping-wing model, the power loading is maximal for the maximum angle of attack of 90°, a flapping amplitude of roughly 45°, and a phase shift between the flapping angle and the angle of attack of roughly 90°. For the revolving-wing model, the power loading peaks for an angle of attack of roughly 45°. In addition, we examine the ground effect on the aerodynamic performance of the revolving-wing model. Secondly, we compare the aerodynamic performance of the flapping- and revolving-wing models at their respective maximal power loadings. It is found that the revolving-wing model is more efficient than the flapping-wing model both when the body of the latter is fixed and where it can move freely. Finally, we discuss the relative agilities of the flapping- and revolving-wing models.

Molecular evidence of keratin and melanosomes in feathers of the Early Cretaceous bird Eoconfuciusornis.

Science.gov (United States)

Pan, Yanhong; Zheng, Wenxia; Moyer, Alison E; O'Connor, Jingmai K; Wang, Min; Zheng, Xiaoting; Wang, Xiaoli; Schroeter, Elena R; Zhou, Zhonghe; Schweitzer, Mary H

2016-12-06

Microbodies associated with feathers of both nonavian dinosaurs and early birds were first identified as bacteria but have been reinterpreted as melanosomes. Whereas melanosomes in modern feathers are always surrounded by and embedded in keratin, melanosomes embedded in keratin in fossils has not been demonstrated. Here we provide multiple independent molecular analyses of both microbodies and the associated matrix recovered from feathers of a new specimen of the basal bird Eoconfuciusornis from the Early Cretaceous Jehol Biota of China. Our work represents the oldest ultrastructural and immunological recognition of avian beta-keratin from an Early Cretaceous (∼130-Ma) bird. We apply immunogold to identify protein epitopes at high resolution, by localizing antibody-antigen complexes to specific fossil ultrastructures. Retention of original keratinous proteins in the matrix surrounding electron-opaque microbodies supports their assignment as melanosomes and adds to the criteria employable to distinguish melanosomes from microbial bodies. Our work sheds new light on molecular preservation within normally labile tissues preserved in fossils.

Temporal trends (1989–2011) in levels of mercury and other heavy metals in feathers of fledgling great egrets nesting in Barnegat Bay, NJ

International Nuclear Information System (INIS)

Burger, Joanna

2013-01-01

There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey) did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2669 ppb to 329 ppb)). Although mercury levels decreased from 2003–2008 (6430 ppb to 1042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6430 ppb) are in the range associated with adverse effects (5000 ppb for feathers). -- Highlights: ► Metals were monitored in feathers of great egrets from Barnegat Bay, New Jersey. ► Levels of cadmium and lead decreased significantly from 1989–2011. ► Mercury levels in feathers from great egrets did not decline from 1989–2011. ► Metal levels were generally higher in great egrets and black-crowned night heron feathers than in snowy egrets

Field dispersal ability and taxis to sex pheromone of irradiated F-1 male Asian corn borer

International Nuclear Information System (INIS)

Wang Huasong; Liu Qiongru; Lu Daguang; Wang Endong; Kang Wen; Li Yongjun; He Qiulan; Hu Jianguo

1998-01-01

The dispersal ability of F-1 male Asian corn borer, Ostrinia furnacalis (Guenee), irradiated with 100, 150 and 200 Gy Separately in parental generation were tested by marking (with Calco oil red or Sudan blue internally)-releasing-recapturing (with synthesized sex pheromone) method in the field where the farthest distance from release point to pheromone trap was 550 m. The results showed that, as compared with the normal male moths, despite of the fact that a part of the irradiated F-1 males had lost dispersal ability or taxis to sex pheromone, there was no significant difference between the captured rates of irradiated F-1 males and normal males in the trap 550 m from release point, indicated that the dispersal ability or taxis to sex pheromone of irradiated F-1 males arrived at 550 m from release point are still well matched with the normal ones

Optimal Fare, Vacancy Rate, and Subsidies under Log-Linear Demand with the Consideration of Externalities for a Cruising Taxi Market

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Chun-Hsiao Chu

2017-01-01

Full Text Available Externality is an important issue for formulating the regulation policy of a taxi market. However, this issue is rarely taken into account in the current policy-making process, and it has not been adequately explored in prior research. This study extends the model proposed by Chang and Chu in 2009 with the aim of exploring the effect of externality on the optimization of the regulation policy of a cruising taxi market. A closed-form solution for optimizing the fare, vacancy rate, and subsidy of the market is derived. The results show that when the externality of taxi trips is taken into consideration, the optimal vacancy rate should be lower and the subsidy should be higher than they are under current conditions where externality is not considered. The results of the sensitivity analysis on the occupied and vacant distance indicate that the relation of the vacant distance to the marginal external cost is more sensitive than the occupied distance. The result of the sensitivity analysis on the subsidy shows the existence of a negative relationship between the marginal external cost and the optimal subsidy.

Concentrations of metals in blood and feathers of nestling ospreys (Pandion haliaetus) in Chesapeake and Delaware Bays

Science.gov (United States)

Rattner, B.A.; Golden, N.H.; Toschik, P.C.; McGowan, P.C.; Custer, T.W.

2008-01-01

In 2000, 2001, and 2002, blood and feather samples were collected from 40-45-day-old nestling ospreys (Pandion haliaetus) from Chesapeake Bay and Delaware Bay and River. Concentrations of 18 metals, metalloids, and other elements were determined in these samples by inductively coupled plasma-mass spectroscopy, and Hg concentrations were measured by cold vapor atomic absorption spectroscopy. When compared to concurrent reference areas (South, West, and Rhode Rivers), mean As and Hg concentrations in blood were greater (p nestlings from the highly industrialized Elizabeth River compared to the rural reference area. When compared to the concurrent reference area, mean Al, Ba, Hg, Mn, and Pb concentrations in feathers were substantially greater (p nestlings from northern Delaware Bay and River had greater concentrations (p nestling feathers from Delaware were frequently greater than in the Chesapeake. The present findings and those of related reproductive studies suggest that concentrations of several heavy metals (e.g., Cd, Hg, Pb) in nestling blood and feathers from Chesapeake and Delaware Bays were below toxicity thresholds and do not seem to be affecting chick survival during the nestling period.

Mercury concentrations in breast feathers of three upper trophic level marine predators from the western Aleutian Islands, Alaska

Science.gov (United States)

Kaler, Robb S.A.; Kenney, Leah A.; Bond, Alexander L.; Eagles-Smith, Collin A.

2014-01-01

Mercury (Hg) is a toxic element distributed globally through atmospheric transport. Agattu Island, located in the western Aleutian Islands, Alaska, has no history of point-sources of Hg contamination. We provide baseline levels of total mercury (THg) concentrations in breast feathers of three birds that breed on the island. Geometric mean THg concentrations in feathers of fork-tailed storm-petrels (Oceanodroma furcata; 6703 ± 1635, ng/g fresh weight [fw]) were higher than all other species, including snowy owl (Bubo scandiacus; 2105 ± 1631, ng/g fw), a raptor with a diet composed largely of storm-petrels at Agattu Island. There were no significant differences in mean THg concentrations of breast feathers among adult Kittlitz’s murrelet (Brachyramphus brevirostris; 1658 ± 1276, ng/g fw) and chicks (1475 ± 671, ng/g fw) and snowy owls. The observed THg concentrations in fork-tailed storm-petrel feathers emphasizes the need for further study of Hg pollution in the western Aleutian Islands.

In vitro gas production tests on irradiated-chicken feathers to estimate its nutritive value as feed for ruminants

International Nuclear Information System (INIS)

Deocaris, Custer C.; De Vera, Azucena C.; Asaad, Celia O.; Ellana, Marivic M.

2003-01-01

Chicken feathers are a highly abundant agro-waste product containing high amount of protein from keratin. However, these are not practically utilized as animal feeds since they provide little, if any nutritional value due to low digestibility in its natural state. Using an in vitro fermentation approach, the ruminant feed potential of chicken feathers treated with gamma-radiation was estimated. Gas production within an incubation period of 96 hours was monitored and values were fitted in the rumen degradability model by McDonald and Orskov (1981). Radiation treatment which could induce depolymerization of chicken feather keratin allowed for the improvement in the nutritive value for ruminants by liberating an additional 7.2% in metabolizable energy (ME) (P<0.005) for ruminant livestock. However, increasing the absorbed dose to 50 kGy resulted in significantly lower energy value for the feather substrate possibility accrued from the induced protein-protein cross-linking phenomenon. (Authors)

Mercury concentrations in breast feathers of three upper trophic level marine predators from the western Aleutian Islands, Alaska.

Science.gov (United States)

Kaler, Robb S A; Kenney, Leah A; Bond, Alexander L; Eagles-Smith, Collin A

2014-05-15

Mercury (Hg) is a toxic element distributed globally through atmospheric transport. Agattu Island, located in the western Aleutian Islands, Alaska, has no history of point-sources of Hg contamination. We provide baseline levels of total mercury (THg) concentrations in breast feathers of three birds that breed on the island. Geometric mean THg concentrations in feathers of fork-tailed storm-petrels (Oceanodroma furcata; 6703 ± 1635, ng/g fresh weight [fw]) were higher than all other species, including snowy owl (Bubo scandiacus; 2105 ± 1631, ng/g fw), a raptor with a diet composed largely of storm-petrels at Agattu Island. There were no significant differences in mean THg concentrations of breast feathers among adult Kittlitz's murrelet (Brachyramphus brevirostris; 1658 ± 1276, ng/g fw) and chicks (1475 ± 671, ng/g fw) and snowy owls. The observed THg concentrations in fork-tailed storm-petrel feathers emphasizes the need for further study of Hg pollution in the western Aleutian Islands. Published by Elsevier Ltd.

Formulation of economical microbial feed using degraded chicken feathers by a novel Streptomyces sp: mitigation of environmental pollution

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Jayapradha Ramakrishnan

2011-09-01

Full Text Available A new Streptomyces sp. IF 5 was isolated from the feather dumped soil and found to have a tremendous keratinase activity. The strain enabled the degradation of the chicken feathers very effectively in 60 h. The 16S rRNA sequence of 1474 bp long was submitted to the National centre for Biotechnological information. The keratinolytic activity in the culture medium was 1181 U/ml. The release and analyses of sulphydryl groups in the culture medium evident the degradation activity by the Streptomyces sp. IF 5. The idea of the present study was to use the degraded chicken feathers as the substrate for the growth and cultivation of microorganisms. We have designed a very economical culture medium that includes the usage of some basal salts alone and degraded chicken feathers (10 g/l. The results of the specific growth rate of the tested microbes confirm the usage of the new designed medium for microbial culturing.

Traceability of poultry viscera meal by stable isotopes in broiler feathers

International Nuclear Information System (INIS)

Araujo, Priscila Cavalca de; Sartori, Jose Roberto; Pezzato, Antonio Celso; Stradiotti, Ana Cristina; Pelicia, Vanessa Cristina; Ducatti, Carlos

2011-01-01

The objective of this work was to evaluate the presence of poultry viscera meal (VM) in the diet of broiler chickens, through the feather analyses by stable isotopes of carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) and mass spectrophotometry. Seven hundred and twenty Cobb male broiler chicks were subjected to the following treatments: vegetable diet based on corn and soybean meal, from 1 to 42 days of age; diet with 8% poultry viscera meal, from 1 to 42 days of age; vegetable diet from 1 to 21 days, and diet with VM from 22 to 42 days; vegetable diet from 1 to 35 days, and diet with VM from 36 to 42 days; diet with VM from 1 to 21 days and, and vegetable diet from 22 to 42 days; diet with VM from 1 to 35 days, and vegetable diet from 36 to 42 days. Feather samples were collected from four birds per treatment at 7, 14, 21, 28, 35 and 42 days of age, which were subjected to isotopic analysis for carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) by mass spectrometry. The use of the stable C and N isotope technique in feathers allow the VM detection in broiler chicken diet after 21 days of VM inclusion. (author)

The Correlation between Duration of Employment, Body Posture and Smoking Habit on Low Back Pain Incidence An Analytic Observational Study Among Taxi Driver in Semarang Municipality

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Syifa Dian Firmanita

2015-06-01

Full Text Available Introduction: Low back pain ((LBP ranks as number two of neurological disease’s highest prevalence after cephalgia and migraine in Indonesia. Objective: This study aim to determine the relationship between duration of employment, body posture and smoking habit on the incidence of low back pain on taxi driver. Method: This research is an observational analytic cross sectional design. Seventyfour taxi drivers in Semarang municipality was screened with Beck’s Depression Inventory Scale to meet the inclusion and exclusion criteria. Respondents were then given Risk Factor of LBP questionnaire. Data were analyzed with a bivariate correlation test contingency coefficient to see the relationship between duration of employment, body posture, smoking habit and low back pain.Result: the taxi driver with duration of employment >10 years were moderate smokers and having astenis body posture. The analysis of correlation coefficients contingency test showed a significance relationship between duration of employment (p = 0,000, body posture (p = 0,000, and moderate smokers (p=0.010 with the incidence of LBP. Conclusion: the taxi driver with duration of employment >10 years with astenis body posture, and moderate smokers were posstively correlated with LBP.

Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

Energy Technology Data Exchange (ETDEWEB)

Jerez, Silvia [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Motas, Miguel, E-mail: motas@um.es [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Palacios, Maria Jose; Valera, Francisco [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Cuervo, Jose Javier; Barbosa, Andres [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, C/Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

2011-10-15

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 {mu}g g{sup -1} dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 {mu}g g{sup -1} dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: > We study levels of trace elements in feathers of Antarctic penguins. > Eight different rookeries throughout the Antarctic Peninsula were sampled. > Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. > Relatively high metal levels were found in areas with major human presence. > Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.

Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

International Nuclear Information System (INIS)

Jerez, Silvia; Motas, Miguel; Palacios, Maria Jose; Valera, Francisco; Cuervo, Jose Javier; Barbosa, Andres

2011-01-01

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 μg g -1 dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 μg g -1 dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: → We study levels of trace elements in feathers of Antarctic penguins. → Eight different rookeries throughout the Antarctic Peninsula were sampled. → Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. → Relatively high metal levels were found in areas with major human presence. → Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.

Mercury in feathers of Swedish gyrfalcons, Falco rusticolus, in relation to diet

International Nuclear Information System (INIS)

Lindberg, P.

1984-01-01

The gyrfalcon (Falco rusticolus) is mainly a resident bird breeding in mountain areas in Fennoscandia. The population (estimated to 300-500 pairs) probably fluctuates according to the presence of willow grouse (Lagopus lagopus) and ptarmigan (Lagopus mutus). Little is known about pollutant levels in Fennoscandian gyrfalcons. Previous studies found low levels of DDE, PCB and mercury in organs from six Norwegian gyrfalcons. In this paper the author has included additional information on mercury levels, based on feather analyses from a few nests in northern Sweden. The use of feathers is a simple method to monitor mercury levels without sacrificing the birds. Food habits were checked by analyzing food remains at and near the nests

Feather mites (Acari, Astigmata) associated with birds in an Atlantic Forest fragment in Northeastern Brazil

OpenAIRE

Silva, HM; Hernandes, FA; Pichorim, M

2015-01-01

AbstractThe present study reports associations between feather mites (Astigmata) and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fiftee...

The peacock's train (Pavo cristatus and Pavo cristatus mut. alba) II. The molecular parameters of feather keratin plasticity.

Science.gov (United States)

Weiss, Ingrid M; Schmitt, Karl P; Kirchner, Helmut O K

2011-06-01

Thermal activation analysis of plastic deformation of peacock tail feathers, by temperature changes and stress relaxation, gave for the keratin cortex an activation enthalpy of 1.78 ± 0.89 eV and an activation volume of 0.83 ± 0.13 nm³, for both the blue and the white subspecies. These values suggest that breaking of electrostatic bonds is responsible for plasticity in feather keratin. These might be bonds between keratin and nonkeratinous matrix or keratin-keratin cross-links. The mechanical properties of the rachis cortex are surprisingly uniform along the length of the feathers. Copyright © 2011 Wiley-Liss, Inc., A Wiley Company.

Study on elements concentrations on seabird feathers by instrumental neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Theophilo, Carolina Y.S.; Moreira, Edson G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), São Paulo, SP (Brazil); Figueira, Rubens C.L.; Colabuono, Fernanda I., E-mail: carolina.theophilo@gmail.com, E-mail: emoreira@ipen.br, E-mail: rfigueira@usp.br, E-mail: ficolabuono@gmail.com [Universidade de São Paulo (USP), São Paulo, SP (Brazil). Instituto Oceanográfico

2017-07-01

Seabirds are very sensitive to environmental changes and because of their large longevity they are also sensitive to cumulative impacts. These birds usually occupy the higher trophic levels. White-chinned petrel (Procellaria aequinoctialis) and black-browed albatross (Thalassarche melanophris) are Procellariiformes, which is a seabird order, composed of 4 families. In the last years, researches are being done and actions are being taken to reduce the mortality of albatrosses and petrels caused by human activities. Due to the great ecological importance of these birds and the developed work with Procellariiformes, this study purpose is to quantify the Br, Cl, Cu, K, Mg, Mn, Na and V elements in white-chinned petrel and black-browed albatross feathers. Bird specimens were killed accidentally by pelagic longline fisheries operating off southern Brazil. Feathers were cleaned with acetone and then milled in a cryogenic mill. Instrumental Neutron Activation Analysis (INAA) was used for quantification of the element concentrations and measurements of induced activities were performed in a HPGe detector for gamma ray spectrometry. The obtained results on feathers showed that concentrations in these birds are not higher than others studies with the same species and, with exception of Br, there are no significant differences between elements mean concentrations in the two seabirds. (author)

Study on elements concentrations on seabird feathers by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Theophilo, Carolina Y.S.; Moreira, Edson G.; Figueira, Rubens C.L.; Colabuono, Fernanda I.

2017-01-01

Seabirds are very sensitive to environmental changes and because of their large longevity they are also sensitive to cumulative impacts. These birds usually occupy the higher trophic levels. White-chinned petrel (Procellaria aequinoctialis) and black-browed albatross (Thalassarche melanophris) are Procellariiformes, which is a seabird order, composed of 4 families. In the last years, researches are being done and actions are being taken to reduce the mortality of albatrosses and petrels caused by human activities. Due to the great ecological importance of these birds and the developed work with Procellariiformes, this study purpose is to quantify the Br, Cl, Cu, K, Mg, Mn, Na and V elements in white-chinned petrel and black-browed albatross feathers. Bird specimens were killed accidentally by pelagic longline fisheries operating off southern Brazil. Feathers were cleaned with acetone and then milled in a cryogenic mill. Instrumental Neutron Activation Analysis (INAA) was used for quantification of the element concentrations and measurements of induced activities were performed in a HPGe detector for gamma ray spectrometry. The obtained results on feathers showed that concentrations in these birds are not higher than others studies with the same species and, with exception of Br, there are no significant differences between elements mean concentrations in the two seabirds. (author)

Aeroelastic Wing Shaping Using Distributed Propulsion

Science.gov (United States)

Nguyen, Nhan T. (Inventor); Reynolds, Kevin Wayne (Inventor); Ting, Eric B. (Inventor)

2017-01-01

An aircraft has wings configured to twist during flight. Inboard and outboard propulsion devices, such as turbofans or other propulsors, are connected to each wing, and are spaced along the wing span. A flight controller independently controls thrust of the inboard and outboard propulsion devices to significantly change flight dynamics, including changing thrust of outboard propulsion devices to twist the wing, and to differentially apply thrust on each wing to change yaw and other aspects of the aircraft during various stages of a flight mission. One or more generators can be positioned upon the wing to provide power for propulsion devices on the same wing, and on an opposite wing.

Do the Golden-winged Warbler and Blue-winged Warbler Exhibit Species-specific Differences in their Breeding Habitat Use?

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Laura L. Patton

2010-12-01

Full Text Available We compared habitat features of Golden-winged Warbler (Vermivora chrysoptera territories in the presence and absence of the Blue-winged Warbler (V. cyanoptera on reclaimed coal mines in southeastern Kentucky, USA. Our objective was to determine whether there are species specific differences in habitat that can be manipulated to encourage population persistence of the Golden-winged Warbler. When compared with Blue-winged Warblers, Golden-winged Warblers established territories at higher elevations and with greater percentages of grass and canopy cover. Mean territory size (minimum convex polygon was 1.3 ha (se = 0.1 for Golden-winged Warbler in absence of Blue-winged Warbler, 1.7 ha (se = 0.3 for Golden-winged Warbler coexisting with Blue-winged Warbler, and 2.1 ha (se = 0.3 for Blue-winged Warbler. Territory overlap occurred within and between species (18 of n = 73 territories, 24.7%. All Golden-winged and Blue-winged Warblers established territories that included an edge between reclaimed mine land and mature forest, as opposed to establishing territories in open grassland/shrubland habitat. The mean distance territories extended from a forest edge was 28.0 m (se = 3.8 for Golden-winged Warbler in absence of Blue-winged Warbler, 44.7 m (se = 5.7 for Golden-winged Warbler coexisting with Blue-winged Warbler, and 33.1 m (se = 6.1 for Blue-winged Warbler. Neither territory size nor distances to forest edges differed significantly between Golden-winged Warbler in presence or absence of Blue-winged Warbler. According to Monte Carlo analyses, orchardgrass (Dactylis glomerata, green ash (Fraxinus pennsylvanica seedlings and saplings, and black locust (Robinia pseudoacacia saplings were indicative of sites with only Golden-winged Warblers. Sericea lespedeza, goldenrod (Solidago spp., clematis vine (Clematis spp., and blackberry (Rubus spp. were indicative of sites where both species occurred. Our findings complement recent genetic studies and add

Experimental and numerical analysis of the wing rock characteristics of a 'wing-body-tail' configuration

Science.gov (United States)

Suarez, Carlos J.; Smith, Brooke C.; Malcolm, Gerald N.

1993-01-01

Free-to-roll wind tunnel tests were conducted and a computer simulation exercise was performed in an effort to investigate in detail the mechanism of wing rock on a configuration that consisted of a highly-slender forebody and a 78 deg swept delta wing. In the wind tunnel test, the roll angle and wing surface pressures were measured during the wing rock motion. A limit cycle oscillation was observed for angles of attack between 22 deg and 30 deg. In general, the wind tunnel test confirmed that the main flow phenomena responsible for the wing-body-tail wing rock are the interactions between the forebody and the wing vortices. The variation of roll acceleration (determined from the second derivative of the roll angle time history) with roll angle clearly showed the energy balance necessary to sustain the limit cycle oscillation. Pressure measurements on the wing revealed the hysteresis of the wing rock process. First, second and nth order models for the aerodynamic damping were developed and examined with a one degree of freedom computer simulation. Very good agreement with the observed behavior from the wind tunnel was obtained.

Cost, Energy, and Environmental Impact of Automated Electric Taxi Fleets in Manhattan.

Science.gov (United States)

Bauer, Gordon S; Greenblatt, Jeffery B; Gerke, Brian F

2018-04-17

Shared automated electric vehicles (SAEVs) hold great promise for improving transportation access in urban centers while drastically reducing transportation-related energy consumption and air pollution. Using taxi-trip data from New York City, we develop an agent-based model to predict the battery range and charging infrastructure requirements of a fleet of SAEVs operating on Manhattan Island. We also develop a model to estimate the cost and environmental impact of providing service and perform extensive sensitivity analysis to test the robustness of our predictions. We estimate that costs will be lowest with a battery range of 50-90 mi, with either 66 chargers per square mile, rated at 11 kW or 44 chargers per square mile, rated at 22 kW. We estimate that the cost of service provided by such an SAEV fleet will be $0.29-$0.61 per revenue mile, an order of magnitude lower than the cost of service of present-day Manhattan taxis and $0.05-$0.08/mi lower than that of an automated fleet composed of any currently available hybrid or internal combustion engine vehicle (ICEV). We estimate that such an SAEV fleet drawing power from the current NYC power grid would reduce GHG emissions by 73% and energy consumption by 58% compared to an automated fleet of ICEVs.

Wedge cells during regeneration of juvenile and adult feathers and their role in carving out the branching pattern of barbs.

Science.gov (United States)

Alibardi, Lorenzo

2007-01-01

The present ultrastructural study on regenerating feathers emphasizes the role of supportive cells in determining the branching pattern of barbs. Supportive cells are localized among developing barb and barbule cells, in marginal plates, and underneath the feather sheath, and their differentiative fate, in general, is a form of lipid degeneration. The Latter process determines the carving out of barb branching in both downfeathers and pennaceous feathers. In the latter feathers, some supportive cells (barb vane cells and cylindrical cells of marginal plates) degenerate within each barb ridge leaving separate barbules. Other supportive cells, here termed wedge cells, form columns of cornified material that merge into elongated corneous scaffolds localized among barbs and the rachis. This previously undescribed form of cornification of supportive cells derives from the aggregation of periderm and dense granules present in wedge cells. The latter cells give origin to a corneous material different from feather keratin that may initially sustain the early and soft barbules. After barbules are cornified the supportive cells scaffolds are eventually sloughed as the sheath breaks allowing the new feather to open up and form a planar vane. The corneous material of wedge cells may also contribute to molding of the overlapped nodes of barbule cells that form lateral spines or hooklets in mature barbules. Eventually, the disappearance of wedge cell scaffolding determines the regular spacing of barbs attached to the rachis in order to form a close vane.

Determination of Oxytetracycline and 4-Epi-Oxytetracycline Residues in Feathers and Edible Tissues of Broiler Chickens Using Liquid Chromatography Coupled with Tandem Mass Spectrometry.

Science.gov (United States)

Cornejo, Javiera; Pokrant, Ekaterina; Krogh, Magdalena; Briceño, Cristóbal; Hidalgo, Héctor; Maddaleno, Aldo; Araya-Jordán, Carolina; Martín, Betty San

2017-04-01

Antibiotics have been widely used in poultry production for the treatment of bacterial diseases. However, drug residues can remain in products derived from animals after the cessation of the drug therapies. Feathers, in particular, have shown an affinity for antibiotics such as tetracycline, suggesting the persistence of these drugs in nonedible tissue. After the birds are slaughtered, feathers are ground into feather meals, which are used as organic fertilizer or an ingredient in animal diets, thereby entering into the food chain and becoming a potential risk for public health. To evaluate the depletion of oxytetracycline (OTC) and its metabolite 4-epi-oxytetracycline (4-epi-OTC) in the muscles, liver, and feathers, 64 broiler chickens, bred under controlled conditions, were treated orally with a commercial formulation of 10% OTC for 7 days. The analytes were quantified using liquid chromatography-tandem mass spectrometry. OTC and 4-epi-OTC were found in the feathers for 46 days, whereas they were found in the muscle and liver for only 12 and 6 days, respectively. These results prove that the analytes remain in feathers in higher concentrations than they do in edible tissues after treatment with tetracyclines. Thus, feather meals represent a potential source of antimicrobial residue contamination in the food chain.

Flexible wings in flapping flight

Science.gov (United States)

Moret, Lionel; Thiria, Benjamin; Zhang, Jun

2007-11-01

We study the effect of passive pitching and flexible deflection of wings on the forward flapping flight. The wings are flapped vertically in water and are allowed to move freely horizontally. The forward speed is chosen by the flapping wing itself by balance of drag and thrust. We show, that by allowing the wing to passively pitch or by adding a flexible extension at its trailing edge, the forward speed is significantly increased. Detailed measurements of wing deflection and passive pitching, together with flow visualization, are used to explain our observations. The advantage of having a wing with finite rigidity/flexibility is discussed as we compare the current results with our biological inspirations such as birds and fish.

Feather retention force in broilers ante-, peri-, and post-mortem as influenced by electrical and carbon dioxide stunning.

Science.gov (United States)

Buhr, R J; Cason, J A; Rowland, G N

1997-11-01

Stunning and slaughter trials were conducted to evaluate the influence of stunning method (electrical 50 V alternating current, CO2 gas: 0 to 40% for 90 s or 40 to 60% for 30 s) on feather retention force (FRF) in commercial broilers. Feathers from the pectoral, sternal, and femoral feather tracts were sampled with a force gauge before stunning (ante-mortem) and contralaterally either after stunning (peri-mortem from 0.5 to 4 min) or after stunning and bleeding (post-mortem from 2 to 6 min). Prior to stunning, ante-mortem FRF values varied among assigned stunning methods only for the pectoral (7%) feather tract. After stunning, peri-mortem FRF values were higher only for the sternal tract (11% for 40 to 60% CO2 for 30 s); whereas after stunning and bleeding, post-mortem FRF values were lower than ante- or peri-mortem only for the sternal tract (10% lower for 40 to 60% CO2 for 30 s). Peri- and post-mortem FRF values did not differ among stunning methods for the pectoral and femoral feather tracts. Small changes in FRF values occurred from ante-mortem to peri-mortem (-1 to +12%), and from ante-mortem to post-mortem (-2 to +8%) across stunning methods. A significant increase was determined for only the pectoral tract (7%) from ante- to peri-mortem across stunning methods. Electrically stunned broilers that were not bled gained weight in excess of the 36 feathers removed (0.16%), apparently due to body surface water pickup during the brine-stunning process, whereas CO2-stunned broilers lost weight due to excretion of cloacal contents (-0.31 to -0.98%). The change in body weight among stunning methods was significant (P defeathering efficiency may not differ after scalding.

Wing Torsional Stiffness Tests of the Active Aeroelastic Wing F/A-18 Airplane

Science.gov (United States)

Lokos, William A.; Olney, Candida D.; Crawford, Natalie D.; Stauf, Rick; Reichenbach, Eric Y.

2002-01-01

The left wing of the Active Aeroelastic Wing (AAW) F/A-18 airplane has been ground-load-tested to quantify its torsional stiffness. The test has been performed at the NASA Dryden Flight Research Center in November 1996, and again in April 2001 after a wing skin modification was performed. The primary objectives of these tests were to characterize the wing behavior before the first flight, and provide a before-and-after measurement of the torsional stiffness. Two streamwise load couples have been applied. The wing skin modification is shown to have more torsional flexibility than the original configuration has. Additionally, structural hysteresis is shown to be reduced by the skin modification. Data comparisons show good repeatability between the tests.

Review Results on Wing-Body Interference

Directory of Open Access Journals (Sweden)

Frolov Vladimir

2016-01-01

Full Text Available The paper presents an overview of results for wing-body interference, obtained by the author for varied wing-body combinations. The lift-curve slopes of the wing-body combinations are considered. In this paper a discrete vortices method (DVM and 2D potential model for cross-flow around fuselage are used. The circular and elliptical cross-sections of the fuselage and flat wings of various forms are considered. Calculations showed that the value of the lift-curve slopes of the wing-body combinations may exceed the same value for an isolated wing. This result confirms an experimental data obtained by other authors earlier. Within a framework of the used mathematical models the investigations to optimize the wing-body combination were carried. The present results of the optimization problem for the wing-body combination allowed to select the optimal geometric characteristics for configuration to maximize the values of the lift-curve slopes of the wing-body combination. It was revealed that maximums of the lift-curve slopes for the optimal mid-wing configuration with elliptical cross-section body had a sufficiently large relative width of the body (more than 30% of the span wing.

A genome-wide association study in a large F2-cross of laying hens reveals novel genomic regions associated with feather pecking and aggressive pecking behavior

OpenAIRE

Lutz, Vanessa; Stratz, Patrick; Preu?, Siegfried; Tetens, Jens; Grashorn, Michael A.; Bessei, Werner; Bennewitz, J?rn

2017-01-01

Background Feather pecking and aggressive pecking in laying hens are serious economic and welfare issues. In spite of extensive research on feather pecking during the last decades, the motivation for this behavior is still not clear. A small to moderate heritability has frequently been reported for these traits. Recently, we identified several single-nucleotide polymorphisms (SNPs) associated with feather pecking by mapping selection signatures in two divergent feather pecking lines. Here, we...

Morphing Wing: Experimental Boundary Layer Transition Determination and Wing Vibrations Measurements and Analysis =

Science.gov (United States)

Tondji Chendjou, Yvan Wilfried

This Master's thesis is written within the framework of the multidisciplinary international research project CRIAQ MDO-505. This global project consists of the design, manufacture and testing of a morphing wing box capable of changing the shape of the flexible upper skin of a wing using an actuator system installed inside the wing. This changing of the shape generates a delay in the occurrence of the laminar to turbulent transition area, which results in an improvement of the aerodynamic performances of the morphed wing. This thesis is focused on the technologies used to gather the pressure data during the wind tunnel tests, as well as on the post processing methodologies used to characterize the wing airflow. The vibration measurements of the wing and their real-time graphical representation are also presented. The vibration data acquisition system is detailed, and the vibration data analysis confirms the predictions of the flutter analysis performed on the wing prior to wind tunnel testing at the IAR-NRC. The pressure data was collected using 32 highly-sensitive piezoelectric sensors for sensing the pressure fluctuations up to 10 KHz. These sensors were installed along two wing chords, and were further connected to a National Instrument PXI real-time acquisition system. The acquired pressure data was high-pass filtered, analyzed and visualized using Fast Fourier Transform (FFT) and Standard Deviation (SD) approaches to quantify the pressure fluctuations in the wing airflow, as these allow the detection of the laminar to turbulent transition area. Around 30% of the cases tested in the IAR-NRC wind tunnel were optimized for drag reduction by the morphing wing procedure. The obtained pressure measurements results were compared with results obtained by infrared thermography visualization, and were used to validate the numerical simulations. Two analog accelerometers able to sense dynamic accelerations up to +/-16g were installed in both the wing and the aileron boxes

Complexities’ day-to-day dynamic evolution analysis and prediction for a Didi taxi trip network based on complex network theory

Science.gov (United States)

Zhang, Lin; Lu, Jian; Zhou, Jialin; Zhu, Jinqing; Li, Yunxuan; Wan, Qian

2018-03-01

Didi Dache is the most popular taxi order mobile app in China, which provides online taxi-hailing service. The obtained big database from this app could be used to analyze the complexities’ day-to-day dynamic evolution of Didi taxi trip network (DTTN) from the level of complex network dynamics. First, this paper proposes the data cleaning and modeling methods for expressing Nanjing’s DTTN as a complex network. Second, the three consecutive weeks’ data are cleaned to establish 21 DTTNs based on the proposed big data processing technology. Then, multiple topology measures that characterize the complexities’ day-to-day dynamic evolution of these networks are provided. Third, these measures of 21 DTTNs are calculated and subsequently explained with actual implications. They are used as a training set for modeling the BP neural network which is designed for predicting DTTN complexities evolution. Finally, the reliability of the designed BP neural network is verified by comparing with the actual data and the results obtained from ARIMA method simultaneously. Because network complexities are the basis for modeling cascading failures and conducting link prediction in complex system, this proposed research framework not only provides a novel perspective for analyzing DTTN from the level of system aggregated behavior, but can also be used to improve the DTTN management level.

No effects of a feather mite on body condition, survivorship, or grooming behavior in the Seychelles warbler, Acrocephalus sechellensis

NARCIS (Netherlands)

Dowling, DK; Richardson, DS; Komdeur, J; Dowling, Damian K.; Richardson, David S.; Czeschlik, T.

A common assumption of studies examining host-symbiont interactions is that all symbiotic organisms are parasitic. Feather mites are widespread symbionts of birds that do not appear to deplete the host of any vital resources. Instead they feed on the oily secretions that cover the feathers and the

Fully Biodegradable Biocomposites with High Chicken Feather Content

OpenAIRE

Aranberri, Ibon; Montes, Sarah; Azcune, Itxaso; Rekondo, Alaitz; Grande, Hans-Jürgen

2017-01-01

The aim of this work was to develop new biodegradable polymeric materials with high loadings of chicken feather (CF). In this study, the effect of CF concentration and the type of biodegradable matrix on the physical, mechanical and thermal properties of the biocomposites was investigated. The selected biopolymers were polylactic acid (PLA), polybutyrate adipate terephthalate (PBAT) and a PLA/thermoplastic copolyester blend. The studied biocomposites were manufactured with a to...

Automatic feathering of split fields for step-and-shoot intensity modulated radiation therapy

International Nuclear Information System (INIS)

Dogan, Nesrin; Leybovich, Leonid B; Sethi, Anil; Emami, Bahman

2003-01-01

Due to leaf travel range limitations of the Varian Dynamic Multileaf Collimator (DMLC) system, an IMRT field width exceeding 14.5 cm is split into two or more adjacent abutting sub-fields. The abutting sub-fields are then delivered as separate treatment fields. The accuracy of the delivery is very sensitive to multileaf positioning accuracy. The uncertainties in leaf and carriage positions cause errors in the delivered dose (e.g., hot or cold spots) along the match line of abutting sub-fields. The dose errors are proportional to the penumbra slope at the edge of each sub-field. To alleviate this problem, we developed techniques that feather the split line of IMRT fields. Feathering of the split line was achieved by dividing IMRT fields into several sub-groups with different split line positions. A Varian 21EX accelerator with an 80-leaf DLMC was used for IMRT delivery. Cylindrical targets with varying widths (>14.5 cm) were created to study the split line positions. Seven coplanar 6 MV fields were selected for planning using the NOMOS-CORVUS TM system. The isocentre of the fields was positioned at the centre of the target volume. Verification was done in a 30 x 30 x 30 cm 3 polystyrene phantom using film dosimetry. We investigated two techniques to move the split line from its original position or cause feathering of them: (1) varying the isocentre position along the target width and (2) introduction of a 'pseudo target' outside of the patient (phantom). The position of the 'pseudo target' was determined by analysing the divergence of IMRT fields. For target widths of 14-28 cm, IMRT fields were automatically split into two sub-fields, and the split line was positioned along the centre of the target by CORVUS. Measured dose distributions demonstrated that the dose to the critical structure was 10% higher than planned when the split line crossed through the centre of the target. Both methods of modifying the split line positions resulted in maximum shifts of ∼1 cm

Genetic and phenotypic correlations between feather pecking and open-field reponse in laying hens at two different ages

NARCIS (Netherlands)

Rodenburg, T.B.; Buitenhuis, A.J.; Ask, B.; Uitdehaag, K.A.; Koene, P.; Poel, van der J.J.; Arendonk, van J.A.M.; Bovenhuis, H.

2004-01-01

The object of this research was to study the relationship between feather pecking and open-field activity in laying hens at two different ages. A population of 550 birds of a laying hen cross was subjected to an open-field test at 5 and 29 weeks of age and to a social feather pecking test at 6 and

Genomic organization and molecular phylogenies of the beta (β keratin multigene family in the chicken (Gallus gallus and zebra finch (Taeniopygia guttata: implications for feather evolution

Directory of Open Access Journals (Sweden)

Sawyer Roger H

2010-05-01

Full Text Available Abstract Background The epidermal appendages of reptiles and birds are constructed of beta (β keratins. The molecular phylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian β-keratin genes are closely related to those of birds, the published genomes of the chicken and zebra finch provide an opportunity not only to compare the genomic organization of their β-keratins, but to study their molecular evolution in archosaurians. Results The subfamilies (claw, feather, feather-like, and scale of β-keratin genes are clustered in the same 5' to 3' order on microchromosome 25 in chicken and zebra finch, although the number of claw and feather genes differs between the species. Molecular phylogenies show that the monophyletic scale genes are the basal group within birds and that the monophyletic avian claw genes form the basal group to all feather and feather-like genes. Both species have a number of feather clades on microchromosome 27 that form monophyletic groups. An additional monophyletic cluster of feather genes exist on macrochromosome 2 for each species. Expression sequence tag analysis for the chicken demonstrates that all feather β-keratin clades are expressed. Conclusions Similarity in the overall genomic organization of β-keratins in Galliformes and Passeriformes suggests similar organization in all Neognathae birds, and perhaps in the ancestral lineages leading to modern birds, such as the paravian Anchiornis huxleyi. Phylogenetic analyses demonstrate that evolution of archosaurian epidermal appendages in the lineage leading to birds was accompanied by duplication and divergence of an ancestral β-keratin gene cluster. As morphological diversification of epidermal appendages occurred and the β-keratin multigene family expanded, novel β-keratin genes were selected for novel functions within appendages such as feathers.

Mechanisms of Wing Beat Sound in Flapping Wings of Beetles

Science.gov (United States)

Allen, John

2017-11-01

While the aerodynamic aspects of insect flight have received recent attention, the mechanisms of sound production by flapping wings is not well understood. Though the harmonic structure of wing beat frequency modulation has been reported with respect to biological implications, few studies have rigorously quantified it with respect directionality, phase coupling and vortex tip scattering. Moreover, the acoustic detection and classification of invasive species is both of practical as well scientific interest. In this study, the acoustics of the tethered flight of the Coconut Rhinoceros Beetle (Oryctes rhinoceros) is investigated with four element microphone array in conjunction with complementary optical sensors and high speed video. The different experimental methods for wing beat determination are compared in both the time and frequency domain. Flow visualization is used to examine the vortex and sound generation due to the torsional mode of the wing rotation. Results are compared with related experimental studies of the Oriental Flower Beetle. USDA, State of Hawaii.

Drag Performance of Twist Morphing MAV Wing

Directory of Open Access Journals (Sweden)

Ismail N.I.

2016-01-01

Full Text Available Morphing wing is one of latest evolution found on MAV wing. However, due to few design problems such as limited MAV wing size and complicated morphing mechanism, the understanding of its aerodynamic behaviour was not fully explored. In fact, the basic drag distribution induced by a morphing MAV wing is still remained unknown. Thus, present work is carried out to compare the drag performance between a twist morphing wing with membrane and rigid MAV wing design. A quasi-static aeroelastic analysis by using the Ansys-Fluid Structure Interaction (FSI method is utilized in current works to predict the drag performance a twist morphing MAV wing design. Based on the drag pattern study, the results exhibits that the morphing wing has a partial similarities in overall drag pattern with the baseline (membrane and rigid wing. However, based CD analysis, it shows that TM wing induced higher CD magnitude (between 25% to 82% higher than to the baseline wing. In fact, TM wing also induced the largest CD increment (about 20% to 27% among the wings. The visualization on vortex structure revealed that TM wing also produce larger tip vortex structure (compared to baseline wings which presume to promote higher induce drag component and subsequently induce its higher CD performance.

Variation in carbon and nitrogen stable isotope ratios in flight feathers of a moulting White-bellied Sunbird Cinnyris talatala

CSIR Research Space (South Africa)

Symes, CT

2011-11-01

Full Text Available The authors measured d13C and d15N isotope signatures in flight feathers of a White-bellied Sunbird to assess the value of using stable isotopes of feathers in avian dietary studies. Significant variation in d13C and d15N isotope values of flight...

Contrasting levels of heavy metals in the feathers of urban pigeons from close habitats suggest limited movements at a restricted scale

International Nuclear Information System (INIS)

Frantz, Adrien; Pottier, Marie-Anne; Karimi, Battle; Corbel, Hélène; Aubry, Emmanuel; Haussy, Claudy; Gasparini, Julien; Castrec-Rouelle, Maryse

2012-01-01

Despite restrictions in emissions, heavy metals may remain a major environmental issue due to their numerous sources and their persistence. Here, we assessed current levels of 4 metals (Copper, Cadmium, Lead, Zinc) in the feathers of 91 feral pigeons (Columba livia) from 7 sites in the urbanized region of Paris. Elements were detected in all pigeons, indicating that metals persist in urbanized areas. The ratio between metal concentrations in the feathers vs. in the environment calculated using data from other studies was 2–90 times higher for cadmium than for other metals, underlying its ecological importance. Concentrations in the feathers depended on locality, suggesting that pigeons remain in local habitats at this restricted scale, as expected from previous observations. Overall, our study suggests that urban feral pigeons may represent a good model system for metal biomonitoring. Highlights: ► We measured the concentrations of 4 heavy metals in pigeon feathers through Paris. ► Cadmium, Copper, Lead and Zinc were present in pigeons from all 7 sites. ► Metals thus still persist in the city though their emissions have been reduced. ► Metal concentrations in the feathers depended on the local origin of the pigeons. ► These differences suggest limited pigeon movements at a very restricted scale. - Concentrations of metals in the feathers of Parisian feral pigeons (Columba livia) strongly differ at a restricted spatial scale, suggesting limited movements in urban areas.

The use of feathers in monitoring bioaccumulation of metals and metalloids in the South African endangered African grass-owl (Tyto capensis).

Science.gov (United States)

Ansara-Ross, T M; Ross, M J; Wepener, V

2013-08-01

Few studies have quantified metals in South African species and no published data on residues specifically in South African owl feathers exist. Tyto capensis is listed as vulnerable within South Africa, making it preferable to use a non-invasive technique to determine metal bioaccumulation for this species. Comparisons are made with the cosmopolitan T. alba to determine whether this species could be used as a surrogate. Concentrations of various metals were thus determined in feathers of the two species and compared with liver and muscle samples. Samples were taken from 119 owls collected as road kill along a national road. A comparison of concentrations in feathers revealed similarly higher concentrations of aluminium, antimony, lead, nickel, and strontium, whereas concentrations of chromium, copper, iron, manganese, selenium, titanium and zinc were similarly higher in internal tissues for both species. Metal concentrations of owls were comparable to those reported in literature and below toxic levels, suggesting that these metals were not likely to impact the owls. Further regressions between feathers and corresponding livers were examined to determine if feathers were indicative of internal metal burdens. Significant positive relationships were found for aluminium, copper, lead, nickel and vanadium in T. alba and nickel, manganese and vanadium in T. capensis. Preliminary results support the feasibility of using feathers as non-destructive indicators of environmental contamination in T. capensis although caution needs to be taken when interpreting the results.

Chicken feather fiber as an additive in MDF composites

Science.gov (United States)

Jerrold E. Winandy; James H. Muehl; Jessie A. Glaeser; Walter Schmidt

2007-01-01

Medium density fiberboard (MDF) panels were made with aspen fiber and 0-95% chicken feather fiber (CFF) in 2.5%, 5%, or 25% increments, using 5% phenol formaldehyde resin as the adhesive. Panels were tested for mechanical and physical properties as well as decay. The addition of CFF decreased strength and stiffness of MDF-CFF composites compared with that of all-wood...

German taxi drivers' experiences and expressions of driving anger: Are the driving anger scale and the driving anger expression inventory valid measures?

Science.gov (United States)

Brandenburg, Stefan; Oehl, Michael; Seigies, Kristin

2017-11-17

The objective of this article was 2-fold: firstly, we wanted to examine whether the original Driving Anger Scale (DAS) and the original Driving Anger Expression Inventory (DAX) apply to German professional taxi drivers because these scales have previously been given to professional and particularly to nonprofessional drivers in different countries. Secondly, we wanted to examine possible differences in driving anger experience and expression between professional German taxi drivers and nonprofessional German drivers. We applied German versions of the DAS, the DAX, and the State-Trait Anger Expression Inventory (STAXI) to a sample of 138 professional German taxi drivers. We then compared their ratings to the ratings of a sample of 1,136 nonprofessional German drivers (Oehl and Brandenburg n.d. ). Regarding our first objective, confirmatory factor analysis shows that the model fit of the DAS is better for nonprofessional drivers than for professional drivers. The DAX applies neither to professional nor to nonprofessional German drivers properly. Consequently, we suggest modified shorter versions of both scales for professional drivers. The STAXI applies to both professional and nonprofessional drivers. With respect to our second objective, we show that professional drivers experience significantly less driving anger than nonprofessional drivers, but they express more driving anger. We conclude that the STAXI can be applied to professional German taxi drivers. In contrast, for the DAS and the DAX we found particular shorter versions for professional taxi drivers. Especially for the DAX, most statements were too strong for German drivers to agree to. They do not show behaviors related to driving anger expression as they are described in the DAX. These problems with the original American DAX items are in line with several other studies in different countries. Future investigations should examine whether (professional) drivers from further countries express their anger

Estimation of directivity and sound power levels emitted by aircrafts during taxiing, for outdoor noise prediction purpose

NARCIS (Netherlands)

Asensio, C.; Pavón, I.; Ruiz, M.; Pagan Munoz, Raul; Recuero, M.

2007-01-01

Integrated noise model (INM) is the most internationally used software to calculate noise levels near airports. Take off, landing or pass by operations can be modeled by INM, but it does not consider aircrafts taxiing, which, in some cases, can be important to accurately evaluate and reduce

[Determination of 10 elements in the feather of brown-eared pheasant by ICP and AAS].

Science.gov (United States)

Wu, Yu-Zhen; Zhang, Feng; Wang, Meng-Ben; Zhao, Gen-Gui

2008-03-01

Crossoptilon mantchuricum (brown-eared pheasant) is an endemic to northern China and one of the state first-protection animals, which is now confined to scattered localities in Guandi Mountains, Guancen Mountains, Luliang Ranges of western Shanxi, and the mountains of north-western Hebei, western Beijing and central Shaanxi. Its range is fragmented by habitat loss because of human activity and other intervention, and isolated populations are resulting in facing the extinction risk from further forest destroyed and other pressures. The trace elements are very important to the growth and development of brown-eared pheasant, and these elements in the feather are closely correlated to the contents in the organs of the bird. By research on the elements contents in the feather, the authors are able to get more information about the growth, development, reproduction, immunity and metabolism function for this bird. The aim of this study is to try providing scientific basis for further enhancing the protection and the artificial breeding. Ten elements including Mo, Zn, Ni, Fe, Mn, Cr, Cu, K, Pb and Cd were determined in the feather of brown-eared pheasant by ICP and AAS, respectively. For the analysis two samples were from Luya Mountain Natural Reserve and Pangquangou Natural Reserve, and one was from Taiyuan Zoo, Shanxi. The contents of the elements in the feather of wild and captive brown-eared pheasants were compared each other. The results showed that the contents of the eight elements the feather from the Zoo were lower than those from Luya Mountain Natural Reserve and Pangquangou Natural Reserve. Moreover, Fe is the highest among those ten elements, Cd was not found, and Mo and Cr were much lower than the others. It is suggested that varying habitats have obvious effects on the elements contents of wild bird body, and wild habitant is more beneficial to the bird growth and development. Applying the results to wild animal management would be favorable to the protection

Chicken feather hydrolysate as an inexpensive complex nitrogen source for PHA production by Cupriavidus necator on waste frying oils.

Science.gov (United States)

Benesova, P; Kucera, D; Marova, I; Obruca, S

2017-08-01

The chicken feather hydrolysate (FH) has been tested as a potential complex nitrogen source for the production of polyhydroxyalkanoates by Cupriavidus necator H16 when waste frying oil was used as a carbon source. The addition of FH into the mineral salt media with decreased inorganic nitrogen source concentration improved the yields of biomass and polyhydrohyalkanoates. The highest yields were achieved when 10 vol.% of FH prepared by microwave-assisted alkaline hydrolysis of 60 g l -1 feather was added. In this case, the poly(3-hydroxybutyrate) (PHB) yields were improved by more than about 50% as compared with control cultivation. A positive impact of FH was also observed for accumulation of copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) when sodium propionate was used as a precursor. The copolymer has superior processing and mechanical properties in comparison with PHB homopolymer. The application of FH eliminated the inhibitory effect of propionate and resulted in altered content of 3-hydroxyvalerate (3HV) in copolymer. Therefore, the hydrolysed feather can serve as an excellent complex source of nitrogen for the polyhydroxyalkanoates (PHA) production. Moreover, by the combination of two inexpensive types of waste, such as waste frying oil and feather hydrolysate, it is possible to produce PHA with substantially improved efficiency and sustainability. Millions of tons of feathers, important waste product of poultry-processing industry, are disposed off annually without any further benefits. Thus, there is an inevitable need for new technologies that enable ecologically and economically sensible processing of this waste. Herein, we report that alkali-hydrolysed feathers can be used as a complex nitrogen source considerably improving polyhydroxyalkanoates production on waste frying oil employing Cupriavidus necator. © 2017 The Society for Applied Microbiology.

Structural Analysis of a Dragonfly Wing

NARCIS (Netherlands)

Jongerius, S.R.; Lentink, D.

2010-01-01

Dragonfly wings are highly corrugated, which increases the stiffness and strength of the wing significantly, and results in a lightweight structure with good aerodynamic performance. How insect wings carry aerodynamic and inertial loads, and how the resonant frequency of the flapping wings is tuned

Butterflies regulate wing temperatures using radiative cooling

Science.gov (United States)

Tsai, Cheng-Chia; Shi, Norman Nan; Ren, Crystal; Pelaez, Julianne; Bernard, Gary D.; Yu, Nanfang; Pierce, Naomi

2017-09-01

Butterfly wings are live organs embedded with multiple sensory neurons and, in some species, with pheromoneproducing cells. The proper function of butterfly wings demands a suitable temperature range, but the wings can overheat quickly in the sun due to their small thermal capacity. We developed an infrared technique to map butterfly wing temperatures and discovered that despite the wings' diverse visible colors, regions of wings that contain live cells are the coolest, resulting from the thickness of the wings and scale nanostructures. We also demonstrated that butterflies use behavioral traits to prevent overheating of their wings.

Keratinase production and biodegradation of polluted secondary chicken feather wastes by a newly isolated multi heavy metal tolerant bacterium-Alcaligenes sp. AQ05-001.

Science.gov (United States)

Yusuf, Ibrahim; Ahmad, Siti Aqlima; Phang, Lai Yee; Syed, Mohd Arif; Shamaan, Nor Aripin; Abdul Khalil, Khalilah; Dahalan, Farrah Aini; Shukor, Mohd Yunus

2016-12-01

Biodegradation of agricultural wastes, generated annually from poultry farms and slaughterhouses, can solve the pollution problem and at the same time yield valuable degradation products. But these wastes also constitute environmental nuisance, especially in Malaysia where their illegal disposal on heavy metal contaminated soils poses a serious biodegradation issue as feather tends to accumulate heavy metals from the surrounding environment. Further, continuous use of feather wastes as cheap biosorbent material for the removal of heavy metals from effluents has contributed to the rising amount of polluted feathers, which has necessitated the search for heavy metal-tolerant feather degrading strains. Isolation, characterization and application of a novel heavy metal-tolerant feather-degrading bacterium, identified by 16S RNA sequencing as Alcaligenes sp. AQ05-001 in degradation of heavy metal polluted recalcitrant agricultural wastes, have been reported. Physico-cultural conditions influencing its activities were studied using one-factor-at-a-time and a statistical optimisation approach. Complete degradation of 5 g/L feather was achieved with pH 8, 2% inoculum at 27 °C and incubation period of 36 h. The medium optimisation after the response surface methodology (RSM) resulted in a 10-fold increase in keratinase production (88.4 U/mL) over the initial 8.85 U/mL when supplemented with 0.5% (w/v) sucrose, 0.15% (w/v) ammonium bicarbonate, 0.3% (w/v) skim milk, and 0.01% (w/v) urea. Under optimum conditions, the bacterium was able to degrade heavy metal polluted feathers completely and produced valuable keratinase and protein-rich hydrolysates. About 83% of the feathers polluted with a mixture of highly toxic metals were degraded with high keratinase activities. The heavy metal tolerance ability of this bacterium can be harnessed not only in keratinase production but also in the bioremediation of heavy metal-polluted feather wastes. Copyright © 2016. Published by

Metal and Isotope Analysis of Bird Feathers in a Contaminated Estuary Reveals Bioaccumulation, Biomagnification, and Potential Toxic Effects.

Science.gov (United States)

Einoder, L D; MacLeod, C K; Coughanowr, C

2018-07-01

The Derwent estuary, in south east Tasmania, is highly contaminated with heavy metals, mainly due to past industrial pollution. This study sought to determine the extent of contamination, bioaccumulation, and biomagnification in the resident bird community and therefore to infer the potential for adverse effects in birds. Thirteen metals were measured from breast feathers (n = 51 individuals) of eight sympatric species of aquatic bird. Stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes were used to identify dietary sources of contaminants, trophic level, and potential biomagnification through food chains. Generalised linear models revealed that metal burdens were often poorly correlated with δ 13 C, indicating their uptake from a range of freshwater, brackish, and marine carbon sources-not surprising due to widespread contamination across the tidal estuary. Feather mercury increased significantly with trophic level (inferred from δ 15 N). White-bellied Sea-eagle Haliaeetus leucogaster samples contained 240 times more mercury than feral Goose Anser cygnoides. Feather arsenic and copper concentrations were significantly higher in birds feeding lower in the food chain. For several piscivorous species, both chick and adults were sampled revealing significantly higher feather mercury, zinc, and selenium in adults. Feathers from birds found dead along the banks of the estuary had significantly higher lead loads than from live birds, and numerous individuals had levels of mercury, zinc, and lead above toxic thresholds reported in other studies. These results highlight the need to include biota from higher trophic levels in contaminant monitoring programs to understand fully the fate and broader implications of contaminants in the environment.

Seabird feathers as monitors of the levels and persistence of heavy metal pollution after the Prestige oil spill