WorldWideScience

Sample records for wing feather taxis

  1. Hovering hummingbird wing aerodynamics during the annual cycle. II. Implications of wing feather moult

    Science.gov (United States)

    Sapir, Nir; Elimelech, Yossef

    2018-01-01

    Birds usually moult their feathers in a particular sequence which may incur aerodynamic, physiological and behavioural implications. Among birds, hummingbirds are unique species in their sustained hovering flight. Because hummingbirds frequently hover-feed, they must maintain sufficiently high flight capacities even when moulting their flight feathers. A hummingbird wing consists of 10 primary flight feathers whose absence during moult may strongly affect wing performance. Using dynamic similarity rules, we compared time-accurate aerodynamic loads and flow field measurements over several wing geometries that follow the natural feather moult sequence of Calypte anna, a common hummingbird species in western North America. Our results suggest a drop of more than 20% in lift production during the early stages of the moult sequence in which mid-wing flight feathers are moulted. We also found that the wing's ability to generate lift strongly depended on the morphological integrity of the outer primaries and leading-edge. These findings may explain the evolution of wing morphology and moult attributes. Specifically, the high overlap between adjacent wing feathers, especially at the wing tip, and the slow sequential replacement of the wing feathers result in a relatively small reduction in wing surface area during moult with limited aerodynamic implications. We present power and efficiency analyses for hover flight during moult under several plausible scenarios, suggesting that body mass reduction could be a compensatory mechanism that preserves the energetic costs of hover flight. PMID:29515884

  2. Artificial Bird Feathers: An Adaptive Wing with High Lift Capability.

    Science.gov (United States)

    Hage, W.; Meyer, R.; Bechert, D. W.

    1997-11-01

    In Wind tunnel experiments, the operation of the covering feathers of bird wings has been investigated. At incipient flow separation, local flow reversal lifts the feathers and inhibits the spreading of the separation regime towards the leading edge. This mechanism can be utilized by movable flaps on airfoils. The operation of quasi-steady and of vibrating movable flaps is outlined. These devices are self-actuated, require no energy and do not produce parasitic drag. They are compatible with laminar and turbulent airfoils as well as with various conventional flaps on aircraft wings. Laboratory and flight experiments are shown. Ref: AIAA-Paper 97-1960.

  3. Aerodynamics and Ecomorphology of Flexible Feathers and Morphing Bird Wings

    Science.gov (United States)

    Klaassen van Oorschot, Brett

    Birds are talented fliers capable of vertical take-off and landing, navigating turbulent air, and flying thousands of miles without rest. How is this possible? What allows birds to exploit the aerial environment with such ease? In part, it may be because bird wings are unlike any engineered wing. They are flexible, strong, lightweight, and dynamically capable of changes in shape on a nearly instantaneous basis (Rayner, 1988; Tobalske, 2007). Moreover, much of this change is passive, modulated only by changes in airflow angle and velocity. Birds actively morph their wings and their feathers morph passively in response to airflow to meet aerodynamic demands. Wings are highly adapted to myriad aeroecological factors and aerodynamic conditions (e.g. Lockwood et al., 1998; Bowlin and Winkler, 2004). This dissertation contains the results of my research on the complexities of morphing avian wings and feathers. I chose to study three related-but-discrete aspects of the avian wing: 1) the aerodynamics of morphing wings during take-off and gliding flight, 2) the presence and significance of wing tip slots across the avian clade, and 3) the aerodynamic role of the emarginate primary feathers that form these wing tip slots. These experiments ask fundamental questions that have intrigued me since childhood: Why do birds have different wing shapes? And why do some birds have slotted wing tips? It's fair to say that you will not find definitive answers here--rather, you will find the methodical, incremental addition of new hypotheses and empirical evidence which will serve future researchers in their own pursuits of these questions. The first chapter explores active wing morphing in two disparate aerodynamic regimes: low-advance ratio flapping (such as during takeoff) and high-advance ratio gliding. This chapter was published in the Journal of Experimental Biology (Klaassen van Oorschot et al., 2016) with the help of an undergraduate researcher, Emily Mistick. We found that wing

  4. Reassessment of the wing feathers of Archaeopteryx lithographica suggests no robust evidence for the presence of elongated dorsal wing coverts.

    Directory of Open Access Journals (Sweden)

    Robert L Nudds

    Full Text Available Recently it was proposed that the primary feathers of Archaeopteryx lithographica (HMN1880 were overlaid by long covert feathers, and that a multilayered feathered wing was a feature of early fossils with feathered forelimbs. The proposed long covert feathers of Archaeopteryx were previously interpreted as dorsally displaced remiges or a second set of impressions made by the wing. The following study shows that the qualitative arguments forwarded in support of the elongated covert hypothesis are neither robust nor supported quantitatively. The idea that the extant bird wing with its single layer of overlapping primaries evolved from an earlier multilayered heavily coveted feathered forelimb as seen in Anchiornis huxleyi is reasonable. At this juncture, however, it is premature to conclude unequivocally that the wing of Archaeopteryx consisted of primary feathers overlaid with elongated coverts.

  5. Flight feather attachment in rock pigeons (Columba livia): covert feathers and smooth muscle coordinate a morphing wing.

    Science.gov (United States)

    Hieronymus, Tobin L

    2016-11-01

    Mechanisms for passively coordinating forelimb movements and flight feather abduction and adduction have been described separately from both in vivo and ex vivo studies. Skeletal coordination has been identified as a way for birds to simplify the neuromotor task of controlling flight stroke, but an understanding of the relationship between skeletal coordination and the coordination of the aerodynamic control surface (the flight feathers) has been slow to materialize. This break between the biomechanical and aerodynamic approaches - between skeletal kinematics and airfoil shape - has hindered the study of dynamic flight behaviors. Here I use dissection and histology to identify previously overlooked interconnections between musculoskeletal elements and flight feathers. Many of these structures are well-placed to directly link elements of the passive musculoskeletal coordination system with flight feather movements. Small bundles of smooth muscle form prominent connections between upper forearm coverts (deck feathers) and the ulna, as well as the majority of interconnections between major flight feathers of the hand. Abundant smooth muscle may play a role in efficient maintenance of folded wing posture, and may also provide an autonomically regulated means of tuning wing shape and aeroelastic behavior in flight. The pattern of muscular and ligamentous linkages of flight feathers to underlying muscle and bone may provide predictable passive guidance for the shape of the airfoil during flight stroke. The structures described here provide an anatomical touchstone for in vivo experimental tests of wing surface coordination in an extensively researched avian model species. © 2016 Anatomical Society.

  6. The presence of quill mites (Gabucinia bicaudata and lice (Struthiolipeurus struthionis in ostrich wing feathers

    Directory of Open Access Journals (Sweden)

    R.G. Cooper

    2006-06-01

    Full Text Available Quill mites (Gabucinia bicaudata and lice (Struthiolipeurus struthionis may infest ostrich feathers, resulting in skin damage, pruritis and excessive feather preening and loss. Four different feather types (prime white, femina extra wide, femina class 1, and femina short; n = 10 were collected. The quill mites and lice were removed with fine forceps, studied using a photographic optical microscope and counted microscopically at ×100 magnification following collection by sedimentation. They were placed in separate Petri dishes containing lactophenol solution and examined (×40 magnification. Anatomical features are described. The density of quill mites in all feather types of both wings was higher than that of the lice. There was no significant difference between the counts of both arthropods on the left wing and the right wing, respectively, except for the femina class 1 quill mites (P = 0.01. The femina extra wide feathers were a preferred habitat in both wings. Large standard deviations (quill mites left wing: 73 + 8; quill mites right wing: 69 + 7 suggested variations in the degree of migration between feather shafts or as a response to escape preening. It is recommended that ostriches be treated with an oral preparation of Ivermectin administered per os at a dosage rate of 0.2 mg / kg at 30-day intervals for quill mites, and with a 1-5 % Malathion dust at 14-day intervals for lice.

  7. Feathered non-avian dinosaurs from North America provide insight into wing origins.

    Science.gov (United States)

    Zelenitsky, Darla K; Therrien, François; Erickson, Gregory M; DeBuhr, Christopher L; Kobayashi, Yoshitsugu; Eberth, David A; Hadfield, Frank

    2012-10-26

    Previously described feathered dinosaurs reveal a fascinating record of feather evolution, although substantial phylogenetic gaps remain. Here we report the occurrence of feathers in ornithomimosaurs, a clade of non-maniraptoran theropods for which fossilized feathers were previously unknown. The Ornithomimus specimens, recovered from Upper Cretaceous deposits of Alberta, Canada, provide new insights into dinosaur plumage and the origin of the avian wing. Individuals from different growth stages reveal the presence of a filamentous feather covering throughout life and winglike structures on the forelimbs of adults. The appearance of winglike structures in older animals indicates that they may have evolved in association with reproductive behaviors. These specimens show that primordial wings originated earlier than previously thought, among non-maniraptoran theropods.

  8. Development of Bird-like Micro Aerial Vehicle with Flapping and Feathering Wing Motions

    Science.gov (United States)

    Maglasang, Jonathan; Goto, Norihiro; Isogai, Koji

    To investigate the feasibility of a highly efficient flapping system capable of avian maneuvers, such as rapid takeoff, hover and gliding, a full scale bird-like (ornithopter) flapping-wing micro aerial vehicle (MAV) shaped and patterned after a typical pigeon (Columba livia) has been designed and constructed. Both numerical and experimental methods have been used in the development of this vehicle. This flapping-wing micro aerial vehicle utilizes both the flapping and feathering motions of an avian wing by employing a novel flapping-feathering mechanism, which has been synthesized and constructed so as to best describe the properly coordinated flapping and feathering wing motions at phase angle difference of 90° in a horizontal steady level flight condition. This design allows high flapping and feathering amplitudes and is configurable for asymmetric wing motions which are desirable in high-speed flapping flight and maneuvering. The preliminary results indicate its viability as a practical and an efficient flapping-wing micro aerial vehicle.

  9. The primary feather lengths of early birds with respect to avian wing shape evolution.

    Science.gov (United States)

    Wang, X; Nudds, R L; Dyke, G J

    2011-06-01

    We examine the relationships between primary feather length (f(prim)) and total arm length (ta) (sum of humerus, ulna and manus lengths) in Mesozoic fossil birds to address one aspect of avian wing shape evolution. Analyses show that there are significant differences in the composition of the wing between the known lineages of basal birds and that mean f(prim) (relative to ta length) is significantly shorter in Archaeopteryx and enantiornithines than it is in Confuciusornithidae and in living birds. Based on outgroup comparisons with nonavian theropods that preserve forelimb primary feathers, we show that the possession of a relatively shorter f(prim) (relative to ta length) must be the primitive condition for Aves. There is also a clear phylogenetic trend in relative primary feather length throughout bird evolution: our analyses demonstrate that the f(prim)/ta ratio increases among successive lineages of Mesozoic birds towards the crown of the tree ('modern birds'; Neornithes). Variance in this ratio also coincides with the enormous evolutionary radiation at the base of Neornithes. Because the f(prim)/ta ratio is linked to flight mode and performance in living birds, further comparisons of wing proportions among Mesozoic avians will prove informative and certainly imply that the aerial locomotion of the Early Cretaceous Confuciusornis was very different to other extinct and living birds. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  10. Distribution of the characteristics of barbs and barbules on barn owl wing feathers.

    Science.gov (United States)

    Weger, Matthias; Wagner, Hermann

    2017-05-01

    Owls are known for the development of a silent flight. One conspicuous specialization of owl wings that has been implied in noise reduction and that has been demonstrated to change the aerodynamic behavior of the wing is a soft dorsal wing surface. The soft surface is a result of changes in the shape of feather barbs and barbules in owls compared with other bird species. We hypothesized that as the aerodynamic characteristics of a wing change along its chordwise and spanwise direction, so may the shape of the barbs and barbules. Therefore, we examined in detail the shapes of the barbs and barbules in chordwise and spanwise directions. The results showed changes in the shapes of barbs and barbules at the anterior and distal parts of the wing, but not at more posterior parts. The increased density of hook radiates at the distalmost wing position could serve to stiffen that vane part that is subject to the highest forces. The change of pennulum length in the anterior part of the wing and the uniformity further back could mean that a soft surface may be especially important in regions where flow separation may occur. © 2017 Anatomical Society.

  11. Sexual Dimorphism and Population Differences in Structural Properties of Barn Swallow (Hirundo rustica Wing and Tail Feathers.

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    Péter L Pap

    Full Text Available Sexual selection and aerodynamic forces affecting structural properties of the flight feathers of birds are poorly understood. Here, we compared the structural features of the innermost primary wing feather (P1 and the sexually dimorphic outermost (Ta6 and monomorphic second outermost (Ta5 tail feathers of barn swallows (Hirundo rustica from a Romanian population to investigate how sexual selection and resistance to aerodynamic forces affect structural differences among these feathers. Furthermore, we compared structural properties of Ta6 of barn swallows from six European populations. Finally, we determined the relationship between feather growth bars width (GBW and the structural properties of tail feathers. The structure of P1 indicates strong resistance against aerodynamic forces, while the narrow rachis, low vane density and low bending stiffness of tail feathers suggest reduced resistance against airflow. The highly elongated Ta6 is characterized by structural modifications such as large rachis width and increased barbule density in relation to the less elongated Ta5, which can be explained by increased length and/or high aerodynamic forces acting at the leading tail edge. However, these changes in Ta6 structure do not allow for full compensation of elongation, as reflected by the reduced bending stiffness of Ta6. Ta6 elongation in males resulted in feathers with reduced resistance, as shown by the low barb density and reduced bending stiffness compared to females. The inconsistency in sexual dimorphism and in change in quality traits of Ta6 among six European populations shows that multiple factors may contribute to shaping population differences. In general, the difference in quality traits between tail feathers cannot be explained by the GBW of feathers. Our results show that the material and structural properties of wing and tail feathers of barn swallows change as a result of aerodynamic forces and sexual selection, although the

  12. Morphometric characterisation of wing feathers of the barn owl Tyto alba pratincola and the pigeon Columba livia

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    Klaas Michael

    2007-11-01

    Full Text Available Abstract Background Owls are known for their silent flight. Even though there is some information available on the mechanisms that lead to a reduction of noise emission, neither the morphological basis, nor the biological mechanisms of the owl's silent flight are known. Therefore, we have initiated a systematic analysis of wing morphology in both a specialist, the barn owl, and a generalist, the pigeon. This report presents a comparison between the feathers of the barn owl and the pigeon and emphasise the specific characteristics of the owl's feathers on macroscopic and microscopic level. An understanding of the features and mechanisms underlying this silent flight might eventually be employed for aerodynamic purposes and lead to a new wing design in modern aircrafts. Results A variety of different feathers (six remiges and six coverts, taken from several specimen in either species, were investigated. Quantitative analysis of digital images and scanning electron microscopy were used for a morphometric characterisation. Although both species have comparable body weights, barn owl feathers were in general larger than pigeon feathers. For both species, the depth and the area of the outer vanes of the remiges were typically smaller than those of the inner vanes. This difference was more pronounced in the barn owl than in the pigeon. Owl feathers also had lesser radiates, longer pennula, and were more translucent than pigeon feathers. The two species achieved smooth edges and regular surfaces of the vanes by different construction principles: while the angles of attachment to the rachis and the length of the barbs was nearly constant for the barn owl, these parameters varied in the pigeon. We also present a quantitative description of several characteristic features of barn owl feathers, e.g., the serrations at the leading edge of the wing, the fringes at the edges of each feather, and the velvet-like dorsal surface. Conclusion The quantitative

  13. The extent of the preserved feathers on the four-winged dinosaur Microraptor gui under ultraviolet light.

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    David W E Hone

    Full Text Available BACKGROUND: The holotype of the theropod non-avian dinosaur Microraptor gui from the Early Cretaceous of China shows extensive preservation of feathers in a halo around the body and with flight feathers associated with both the fore and hindlimbs. It has been questioned as to whether or not the feathers did extend into the halo to reach the body, or had disassociated and moved before preservation. This taxon has important implications for the origin of flight in birds and the possibility of a four-winged gliding phase. METHODOLOGY/PRINCIPAL FINDINGS: Examination of the specimen under ultraviolet light reveals that these feathers actually reach the body of the animal and were not disassociated from the bones. Instead they may have been chemically altered by the body tissues of the animal meaning that they did not carbonise close into the animal or more likely were covered by other decaying tissue, though evidence of their presence remains. CONCLUSIONS/SIGNIFICANCE: These UV images show that the feathers preserved on the slab are genuinely associated with the skeleton and that their arrangement and orientation is likely correct. The methods used here to reveal hidden features of the specimen may be applicable to other specimens from the fossil beds of Liaoning that produced Microraptor.

  14. The presence of quill mites (Gabucinia bicaudata) and lice (Struthiolipeurus struthionis) in ostrich wing feathers

    OpenAIRE

    R.G. Cooper; H.A.A. El Doumani

    2006-01-01

    Quill mites (Gabucinia bicaudata) and lice (Struthiolipeurus struthionis) may infest ostrich feathers, resulting in skin damage, pruritis and excessive feather preening and loss. Four different feather types (prime white, femina extra wide, femina class 1, and femina short; n = 10) were collected. The quill mites and lice were removed with fine forceps, studied using a photographic optical microscope and counted microscopically at ×100 magnification following collection by sedimentation. The...

  15. Hind wings in Basal birds and the evolution of leg feathers.

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    Zheng, Xiaoting; Zhou, Zhonghe; Wang, Xiaoli; Zhang, Fucheng; Zhang, Xiaomei; Wang, Yan; Wei, Guangjin; Wang, Shuo; Xu, Xing

    2013-03-15

    Recent discoveries of large leg feathers in some theropods have implications for our understanding of the evolution of integumentary features on the avialan leg, and particularly of their relevance for the origin of avialan flight. Here we report 11 basal avialan specimens that will greatly improve our knowledge of leg integumentary features among early birds. In particular, they provide solid evidence for the existence of enlarged leg feathers on a variety of basal birds, suggest that extensively scaled feet might have appeared secondarily at an early stage in ornithuromorph evolution, and demonstrate a distal-to-proximal reduction pattern for leg feathers in avialan evolution.

  16. The development of a closed-loop flight controller with panel method integration for gust alleviation using biomimetic feathers on aircraft wings

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    Blower, Christopher J.; Lee, Woody; Wickenheiser, Adam M.

    2012-04-01

    This paper presents the development of a biomimetic closed-loop flight controller that integrates gust alleviation and flight control into a single distributed system. Modern flight controllers predominantly rely on and respond to perturbations in the global states, resulting in rotation or displacement of the entire aircraft prior to the response. This bio-inspired gust alleviation system (GAS) employs active deflection of electromechanical feathers that react to changes in the airflow, i.e. the local states. The GAS design is a skeletal wing structure with a network of featherlike panels installed on the wing's surfaces, creating the airfoil profile and replacing the trailing-edge flaps. In this study, a dynamic model of the GAS-integrated wing is simulated to compute gust-induced disturbances. The system implements continuous adjustment to flap orientation to perform corrective responses to inbound gusts. MATLAB simulations, using a closed-loop LQR integrated with a 2D adaptive panel method, allow analysis of the morphing structure's aerodynamic data. Non-linear and linear dynamic models of the GAS are compared to a traditional single control surface baseline wing. The feedback loops synthesized rely on inertial changes in the global states; however, variations in number and location of feather actuation are compared. The bio-inspired system's distributed control effort allows the flight controller to interchange between the single and dual trailing edge flap profiles, thereby offering an improved efficiency to gust response in comparison to the traditional wing configuration. The introduction of aero-braking during continuous gusting flows offers a 25% reduction in x-velocity deviation; other flight parameters can be reduced in magnitude and deviation through control weighting optimization. Consequently, the GAS demonstrates enhancements to maneuverability and stability in turbulent intensive environments.

  17. Modeling taxi demand with GPS data from taxis and transit.

    Science.gov (United States)

    2014-07-01

    Identifying factors that influence taxi demand is very important for understanding where and when people use taxis and how taxi demand relates to the availability and quality of transit service. This study used a large set of global positioning syste...

  18. Taxi 'sugar daddies' and taxi queens: Male taxi driver attitudes ...

    African Journals Online (AJOL)

    Cheryl Potgieter, Anna Strebel, Tamara Shefer, and Claire Wagner

    2012-12-14

    Dec 14, 2012 ... have sex with the drivers in exchange for gifts and money. The extent to which such relationships might facilitate unsafe sexual practices and increased risks for both the men and the young women, often referred to as taxi queens, remains an important question in the light of the current challenges of ...

  19. Taxi 'sugar daddies' and taxi queens: Male taxi driver attitudes ...

    African Journals Online (AJOL)

    Media reports are emerging on the phenomenon of young girls who travel with older mini-bus taxi drivers, and who are thought to have sex with the drivers in exchange for gifts and money. The extent to which such relationships might facilitate unsafe sexual practices and increased risks for both the men and the young ...

  20. 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.

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

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    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.

  2. Avian Feathers: An Examination of Lightweight Resilience and Bioinspired Designs

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    Sullivan, Tarah Naoe

    In bird flight, the majority of the wing surface consists of highly refined and hierarchically organized beta-keratinous feathers. Thus, flight feathers contain ingenious combinations of components that optimize lift, stiffness, aerodynamics, and damage resistance. Their design involves two main parts: a central shaft which prescribes stiffness and lateral vanes that allow for the capture of air. Within the feather vane, barbs branch from the shaft and barbules branch from barbs, forming a flat surface and ensuring lift. Microhooks at the end of barbules hold barbs tightly together, providing a close-knit, unified structure and enabling repair of the vane through the reattachment of un-hooked junctions. In this dissertation, unique aspects of feather architecture are explored to uncover principles translatable to the design of modern aerospace materials and structures. Specifically, understudied aspects of the feather's lightweight yet resilient properties are investigated. This research has revealed several novel characteristics of the feather. Allometric scaling relationships are developed linking the geometry of a bird's wing components to its flight characteristics and total mass. Barbule spacing within the feather vane is found to be 8-16 microm for birds ranging from 0.02-11 kg. Additionally, it is discovered that strength is recovered with the shape recovery property of feathers, and a mechanism for this phenomenon is proposed. Barbule adhesion within the vane is found to prevent barbs from twisting in flexure, maintaining the vane's stiffness, and the extent to which unzipping these connections affects the feather's ability to capture air is related to barb shape. Directional permeability of the feather vane is experimentally confirmed and related to the intricate microstructure of barbules. Lastly, the exceptional architecture of the feather motivated the design of novel bioinspired structures with tailored and unique properties. The avian feather serves

  3. Effect of outer wing separation on lift and thrust generation in a flapping wing system

    International Nuclear Information System (INIS)

    Mahardika, Nanang; Viet, Nguyen Quoc; Park, Hoon Cheol

    2011-01-01

    We explore the implementation of wing feather separation and lead-lagging motion to a flapping wing. A biomimetic flapping wing system with separated outer wings is designed and demonstrated. The artificial wing feather separation is implemented in the biomimetic wing by dividing the wing into inner and outer wings. The features of flapping, lead-lagging, and outer wing separation of the flapping wing system are captured by a high-speed camera for evaluation. The performance of the flapping wing system with separated outer wings is compared to that of a flapping wing system with closed outer wings in terms of forward force and downward force production. For a low flapping frequency ranging from 2.47 to 3.90 Hz, the proposed biomimetic flapping wing system shows a higher thrust and lift generation capability as demonstrated by a series of experiments. For 1.6 V application (lower frequency operation), the flapping wing system with separated wings could generate about 56% higher forward force and about 61% less downward force compared to that with closed wings, which is enough to demonstrate larger thrust and lift production capability of the separated outer wings. The experiments show that the outer parts of the separated wings are able to deform, resulting in a smaller amount of drag production during the upstroke, while still producing relatively greater lift and thrust during the downstroke.

  4. 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.

  5. AERODYNAMICS OF WING TIP SAILS

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    MUSHTAK AL-ATABI

    2006-06-01

    Full Text Available Observers have always been fascinated by soaring birds. An interesting feature of these birds is the existence of few feathers extending from the tip of the wing. In this paper, small lifting surfaces were fitted to the tip of a NACA0012 wing in a fashion similar to that of wing tip feathers. Experimental measurements of induced drag, longitudinal static stability and trailing vortex structure were obtained.The tests showed that adding wing tip surfaces (sails decreased the induced drag factor and increased the longitudinal static stability. Results identified two discrete appositely rotated tip vortices and showed the ability of wing tip surfaces to break them down and to diffuse them.

  6. 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 ...

  7. Yellow taxis have fewer accidents than blue taxis because yellow is more visible than blue

    OpenAIRE

    Ho, Teck-Hua; Chong, Juin Kuan; Xia, Xiaoyu

    2017-01-01

    Is there a link between the color of a taxi and how many accidents it has? An analysis of 36 mo of detailed taxi, driver, and accident data (comprising millions of data points) from the largest taxi company in Singapore suggests that there is an explicit link. Yellow taxis had 6.1 fewer accidents per 1,000 taxis per month than blue taxis, a 9% reduction in accident probability. We rule out driver difference as an explanatory variable and empirically show that because yellow taxis are more not...

  8. 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.

  9. Taxi 'sugar daddies' and taxi queens: male taxi driver attitudes regarding transactional relationships in the Western Cape, South Africa.

    Science.gov (United States)

    Potgieter, Cheryl; Strebel, Anna; Shefer, Tamara; Wagner, Claire

    2012-11-01

    Media reports are emerging on the phenomenon of young girls who travel with older mini-bus taxi drivers, and who are thought to have sex with the drivers in exchange for gifts and money. The extent to which such relationships might facilitate unsafe sexual practices and increased risks for both the men and the young women, often referred to as taxi queens, remains an important question in the light of the current challenges of HIV/AIDS in sub-Saharan Africa. However, very little research has been undertaken on this issue, especially regarding the perceptions and experiences of taxi drivers. Thus this paper aims to provide some preliminary findings on taxi drivers' attitudes and beliefs about taxi queens and their relationships with taxi drivers. A 22-item questionnaire was administered to 223 male taxi drivers in two regions in the Western Cape Province, South Africa. Taxi drivers in this study largely saw the relationship between taxi drivers and the young girls who ride with them as providing status for both the girls and drivers, and there seemed to be recognition of the transactional nature of the relationship between taxi drivers and taxi queens. The stigmatisation of young girls who ride with taxi drivers was evident. Drivers had knowledge and awareness of the risks of unsafe sex and supported condom use, although there appeared to be some uncertainty and confusion about the likelihood of HIV infection between drivers and girls. While taxi drivers recognised the role of alcohol in relationships with young girls, they seemed to deny that the abuse of drugs was common. The study highlights a number of key areas that need to be explored with men in the taxi industry, in order to address risk behaviours for both taxi drivers and the girls who ride with them.

  10. 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 ...

  11. Yellow taxis have fewer accidents than blue taxis because yellow is more visible than blue.

    Science.gov (United States)

    Ho, Teck-Hua; Chong, Juin Kuan; Xia, Xiaoyu

    2017-03-21

    Is there a link between the color of a taxi and how many accidents it has? An analysis of 36 mo of detailed taxi, driver, and accident data (comprising millions of data points) from the largest taxi company in Singapore suggests that there is an explicit link. Yellow taxis had 6.1 fewer accidents per 1,000 taxis per month than blue taxis, a 9% reduction in accident probability. We rule out driver difference as an explanatory variable and empirically show that because yellow taxis are more noticeable than blue taxis-especially when in front of another vehicle, and in street lighting-other drivers can better avoid hitting them, directly reducing the accident rate. This finding can play a significant role when choosing colors for public transportation and may save lives as well as millions of dollars.

  12. Quantification of feather structure, wettability and resistance to liquid penetration

    Science.gov (United States)

    Srinivasan, Siddarth; Chhatre, Shreerang S.; Guardado, Jesus O.; Park, Kyoo-Chul; Parker, Andrew R.; Rubner, Michael F.; McKinley, Gareth H.; Cohen, Robert E.

    2014-01-01

    Birds in the cormorant (Phalacrocoracidae) family dive tens of metres into water to prey on fish while entraining a thin layer of air (a plastron film) within the microstructures of their feathers. In addition, many species within the family spread their wings for long periods of time upon emerging from water. To investigate whether wetting and wing-spreading are related to feather structure, microscopy and photographic studies have previously been used to extract structural parameters for barbs and barbules. In this work, we describe a systematic methodology to characterize the quasi-hierarchical topography of bird feathers that is based on contact angle measurements using a set of polar and non-polar probing liquids. Contact angle measurements on dip-coated feathers of six aquatic bird species (including three from the Phalacrocoracidae family) are used to extract two distinguishing structural parameters, a dimensionless spacing ratio of the barbule (D*) and a characteristic length scale corresponding to the spacing of defect sites. The dimensionless spacing parameter can be used in conjunction with a model for the surface topography to enable us to predict a priori the apparent contact angles of water droplets on feathers as well as the water breakthrough pressure required for the disruption of the plastron on the feather barbules. The predicted values of breakthrough depths in water (1–4 m) are towards the lower end of typical diving depths for the aquatic bird species examined here, and therefore a representative feather is expected to be fully wetted in a typical deep dive. However, thermodynamic surface energy analysis based on a simple one-dimensional cylindrical model of the feathers using parameters extracted from the goniometric analysis reveals that for water droplets on feathers of all six species under consideration, the non-wetting ‘Cassie–Baxter’ composite state represents the global energy minimum of the system. By contrast, for other

  13. Comparative Analysis of Uninhibited and Constrained Avian Wing Aerodynamics

    Science.gov (United States)

    Cox, Jordan A.

    The flight of birds has intrigued and motivated man for many years. Bird flight served as the primary inspiration of flying machines developed by Leonardo Da Vinci, Otto Lilienthal, and even the Wright brothers. Avian flight has once again drawn the attention of the scientific community as unmanned aerial vehicles (UAV) are not only becoming more popular, but smaller. Birds are once again influencing the designs of aircraft. Small UAVs operating within flight conditions and low Reynolds numbers common to birds are not yet capable of the high levels of control and agility that birds display with ease. Many researchers believe the potential to improve small UAV performance can be obtained by applying features common to birds such as feathers and flapping flight to small UAVs. Although the effects of feathers on a wing have received some attention, the effects of localized transient feather motion and surface geometry on the flight performance of a wing have been largely overlooked. In this research, the effects of freely moving feathers on a preserved red tailed hawk wing were studied. A series of experiments were conducted to measure the aerodynamic forces on a hawk wing with varying levels of feather movement permitted. Angle of attack and air speed were varied within the natural flight envelope of the hawk. Subsequent identical tests were performed with the feather motion constrained through the use of externally-applied surface treatments. Additional tests involved the study of an absolutely fixed geometry mold-and-cast wing model of the original bird wing. Final tests were also performed after applying surface coatings to the cast wing. High speed videos taken during tests revealed the extent of the feather movement between wing models. Images of the microscopic surface structure of each wing model were analyzed to establish variations in surface geometry between models. Recorded aerodynamic forces were then compared to the known feather motion and surface

  14. Feather loss and feather destructive behavior in pet birds.

    Science.gov (United States)

    Rubinstein, Jonathan; Lightfoot, Teresa

    2014-01-01

    Feather loss in psittacine birds is a common and frustrating clinical presentation. Causes include medical and nonmedical causes of feather loss with and without overt feather destructive behavior. Underlying causes include inappropriate husbandry and housing; parasitic, viral and bacterial infections; metabolic and allergic diseases; and behavioral disorders. Prior to a diagnosis of a behavioral disorder, medical causes of feather loss must be excluded through a complete medical work-up including history, physical examination, and diagnostic testing. This article focuses on common medical and nonmedical causes of feather loss and feather destructive behavior and approaches to diagnosis and treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2003-01-01

    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

  16. Body feathers as a potential new biomonitoring tool in raptors: a study on organohalogenated contaminants in different feather types and preen oil of West Greenland white-tailed eagles (Haliaeetus albicilla).

    Science.gov (United States)

    Jaspers, Veerle L B; Rodriguez, Francisco Soler; Boertmann, David; Sonne, Christian; Dietz, Rune; Rasmussen, Lars Maltha; Eens, Marcel; Covaci, Adrian

    2011-11-01

    We investigated the variation in concentrations and profiles of various classes of organohalogenated compounds (OHCs) in different feather types, muscle tissue and preen oil from 15 white-tailed eagle (Haliaeetus albicilla) carcasses from Greenland. The influence of moult patterns and potential external contamination onto the feather surface was examined, while the present study is also the first to investigate the use of body feathers for OHC monitoring. Concentrations of sum polychlorinated biphenyls (PCBs) in feathers from white tailed eagles ranged from 2.3 ng/g in a primary wing feather to 4200 ng/g in body feathers. Using 300 mg of body feathers, almost 50 different OHCs could be quantified and median concentrations in body feathers were 10 fold higher than concentrations in tail feathers (rectrices) or primary wing feathers. Body feathers could be very useful for biomonitoring taking into account their easy sampling, short preparation time and high levels of OHCs. In addition, the effects of confounding variables such as feather size, moult and age are also minimised using body feathers. Correlations with concentrations in muscle tissue and preen oil were high and significant for all feather types (r ranging from 0.81 to 0.87 for sum PCBs). Significant differences in concentrations and profiles of OHCs were found between different primary feathers, indicating that the accumulation of OHCs in feathers varies over the moulting period (maximum three years). Washing of feathers with an organic solvent (acetone) resulted in a significant decrease in the measured concentrations of OHCs in feathers. However, our results indicated that preen oil is probably not the only contributor to the external contamination that can be removed by washing with acetone. Possibly dust and other particles may be of importance and may be sticking to the preened feathers. Rectrices washed only with water showed high and significant correlations with concentrations in muscle and preen

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

    Science.gov (United States)

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

    2003-01-01

    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.

  18. 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.

  19. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Exploring Urban Taxi Drivers’ Activity Distribution Based on GPS Data

    Directory of Open Access Journals (Sweden)

    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.

  2. 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

  3. 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.

  4. 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.

  5. Exploring Urban Taxi Drivers’ Activity Distribution Based on GPS Data

    OpenAIRE

    Hu, Xiaowei; An, Shi; Wang, Jian

    2014-01-01

    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 l...

  6. 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

  7. 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 ...

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

    Science.gov (United States)

    Zhang, Sihai; Wang, Zhiyang

    2016-01-01

    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 data analysis in

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

    Directory of Open Access Journals (Sweden)

    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

  10. Tracking Seasonal Habitats Using Carbon and Nitrogen Stable Isotopes of Osprey Primary Flight Feathers

    Science.gov (United States)

    Velinsky, D.; Zelanko, P.; Rice, N.

    2011-12-01

    The majority of bird migration studies use the latitudinal precipitation effect of hydrogen and oxygen stable isotopes of feathers to determine wintering and breeding grounds. Few studies have considered carbon and nitrogen stable isotopes to accomplish the same goal; exploiting the variation in dietary constitutes throughout yearly migration cycles. Also, there is no standard procedure of feather sampling; some use body, while others use wing feathers. This sampling discrepancy is not an issue for most migratory species since the majority of birds molt completely in one location, i.e. wintering verse breeding ground. Large birds of prey however, have a continuous molt that may last years, growing feathers on their breeding and wintering grounds. Therefore, a stable isotopic study of Osprey could not randomly sample feathers because it is impossible to know where individual feathers were grown. Here we present an in depth study of carbon and nitrogen stable isotopes from Mid-Atlantic Osprey primary flight feathers. Not only did we observe three signatures indicating the breeding ground and two distinct wintering grounds, we recorded dietary seasonality shifts within 2 to 3 year olds that remain on the wintering grounds for multiple years.

  11. Aeroelastic flutter of feathers, flight and the evolution of non-vocal communication in birds.

    Science.gov (United States)

    Clark, Christopher J; Prum, Richard O

    2015-11-01

    Tonal, non-vocal sounds are widespread in both ordinary bird flight and communication displays. We hypothesized these sounds are attributable to an aerodynamic mechanism intrinsic to flight feathers: aeroelastic flutter. Individual wing and tail feathers from 35 taxa (from 13 families) that produce tonal flight sounds were tested in a wind tunnel. In the wind tunnel, all of these feathers could flutter and generate tonal sound, suggesting that the capacity to flutter is intrinsic to flight feathers. This result implies that the aerodynamic mechanism of aeroelastic flutter is potentially widespread in flight of birds. However, the sounds these feathers produced in the wind tunnel replicated the actual flight sounds of only 15 of the 35 taxa. Of the 20 negative results, we hypothesize that 10 are false negatives, as the acoustic form of the flight sound suggests flutter is a likely acoustic mechanism. For the 10 other taxa, we propose our negative wind tunnel results are correct, and these species do not make sounds via flutter. These sounds appear to constitute one or more mechanism(s) we call 'wing whirring', the physical acoustics of which remain unknown. Our results document that the production of non-vocal communication sounds by aeroelastic flutter of flight feathers is widespread in birds. Across all birds, most evolutionary origins of wing- and tail-generated communication sounds are attributable to three mechanisms: flutter, percussion and wing whirring. Other mechanisms of sound production, such as turbulence-induced whooshes, have evolved into communication sounds only rarely, despite their intrinsic ubiquity in ordinary flight. © 2015. Published by The Company of Biologists Ltd.

  12. Development, regeneration, and evolution of feathers.

    Science.gov (United States)

    Chen, Chih-Feng; Foley, John; Tang, Pin-Chi; Li, Ang; Jiang, Ting Xin; Wu, Ping; Widelitz, Randall B; Chuong, Cheng Ming

    2015-01-01

    The feather is a complex ectodermal organ with hierarchical branching patterns. It provides functions in endothermy, communication, and flight. Studies of feather growth, cycling, and health are of fundamental importance to avian biology and poultry science. In addition, feathers are an excellent model for morphogenesis studies because of their accessibility, and their distinct patterns can be used to assay the roles of specific molecular pathways. Here we review the progress in aspects of development, regeneration, and evolution during the past three decades. We cover the development of feather buds in chicken embryos, regenerative cycling of feather follicle stem cells, formation of barb branching patterns, emergence of intrafeather pigmentation patterns, interplay of hormones and feather growth, and the genetic identification of several feather variants. The discovery of feathered dinosaurs redefines the relationship between feathers and birds. Inspiration from biomaterials and flight research further fuels biomimetic potential of feathers as a multidisciplinary research focal point.

  13. Light diffraction through a feather

    Directory of Open Access Journals (Sweden)

    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.

  14. Math on the Job. Taxi Driver.

    Science.gov (United States)

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This booklet is intended to help mainstreamed mentally retarded, emotionally disturbed, or learning disabled high school students acquire a basic understanding of the responsibilities and working conditions of taxi drivers and to practice basic math skills necessary in the occupation. The first section provides a brief introduction to the…

  15. Cardiovascular Risk Factors of Taxi Drivers.

    Science.gov (United States)

    Elshatarat, Rami Azmi; Burgel, Barbara J

    2016-06-01

    In the United States (U.S.), cardiovascular disease (CVD) is a major leading cause of death. Despite the high mortality rate related to CVD, little is known about CVD risk factors among urban taxi drivers in the U.S. A cross-sectional design was used to identify the predictors of high cardiovascular risk factors among taxi drivers. Convenience sampling method was used to recruit 130 taxi drivers. A structured questionnaire was used to obtain the data. The sample was male (94 %), age mean (45 ± 10.75) years, married (54 %), born outside of the USA (55 %), had some college or below (61.5 %), night drivers (50.8 %), and driving on average 9.7 years and 41 h/week. About 79 % of them were eligible for CVD prevention, and 35.4 % had high CVD risk factors (4-9 risk factors). A CVD high-risk profile had a significant relationship with the subjects who were ≥55 years old; had hypertension, diabetes, or hyperlipidemia; were drinking alcohol ≥2 times/week; and had insufficient physical activity. Subjects who worked as a taxi driver for more than 10 years (OR 4.37; 95 % CI 1.82, 10.50) and had mental exertion from cab driving >5 out of 10 (OR 2.63; 95 % CI 1.05, 6.57) were more likely to have a CVD high-risk profile. As a conclusion, system-level or worksite interventions include offering healthy food at taxi dispatching locations, creating a work culture of frequent walking breaks, and interventions focusing on smoking, physical activity, and weight management. Improving health insurance coverage for this group of workers is recommended.

  16. 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.

  17. Individual consistency of feather pecking behavior in laying hens: once a feather pecker always a feather pecker?

    Directory of Open Access Journals (Sweden)

    Courtney L Daigle

    2015-04-01

    Full Text Available TThe pecking behavior (severe feather, gentle feather, and aggressive pecks of individual White Shaver non-cage laying hens (n = 300 was examined at 21, 24, 27, 32, and 37 wk. Hens were housed in 30 groups of 10 hens each and on 3cm litter with access to a feeder, perch, and two nest boxes. The number of severe feather pecks given and received was used to categorize hens as feather peckers (P, victims (V, neutrals (N, or feather pecker-victims (PV at each age. Hens categorized as PV exhibited pecking behaviors similar to P and received pecks similar to V. Severe feather pecks (SFP given were correlated with aggressive pecks given, but not with gentle feather pecks given throughout the study. State transition plot maps illustrated that 22.5% of P remained P, while 44% of PV remained PV throughout the duration of the study. Lifetime behavioral categories identified hens as a consistent feather pecker (5%, consistent neutral (3.9%, consistent victim (7.9%, consistent feather pecker-victim (29.4%, or inconsistent (53.8% in their behavioral patterns throughout their life. Consistent feather peckers performed more SFP than hens of other categories, and consistent neutral hens received fewer gentle feather pecks than consistent feather pecker-victims. No differences in corticosterone or whole blood serotonin levels were observed among the categories. Approximately half of the population was classified as a feather pecker at least once during the study, while the remainder was never categorized as a feather pecker. Therefore, even if the development and cause of feather pecking may be multi-factorial, once the behavior has been developed, some hens may persist in feather pecking. However, as some hens were observed to never receive or perform severe feather pecks, emphasis should be made to select for these hens in future breeding practices.

  18. 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.

  19. Taxi driver seat belt wearing in Nanjing, China.

    Science.gov (United States)

    Routley, Virginia; Ozanne-Smith, Joan; Qin, Yu; Wu, Ming

    2009-01-01

    To determine and validate patterns of seat belt use and attitudes of taxi drivers on wearing a seat belt following national and provincial seat belt legislation in 2004-2005. Roadside daylight seat belt observation and interview survey methods were used, as well as observations from inside taxis during routine trips and a taxi driver focus group. The setting was Nanjing, Jiangsu Province, PR China in April of 2006 and 2007. Prevalence of seat belt use and attitudes to wearing a seat belt were determined, as were vehicle and driver characteristics, and comparisons with other motor-vehicle driver's seat belt use and attitudes. Taxi drivers interviewed were predominantly male and aged 30-39 years. They spent more hours per week in their vehicles and had more driving experience than other drivers. Over half (56.2%) of taxi drivers interviewed reported that they always wore seat belts, while observation of taxi drivers showed lower wearing rates (i.e., roadside observation was 43.8%, and observation from inside taxis was 36.2%). Belt tampering was a practice of 12-15% of taxi drivers. "Fine avoidance, safety, high speed and long trips" were given as important reasons for wearing and "feeling trapped and uncomfortable" for not wearing. Seat belt reminder signs in taxis were common (82.6% of taxis), but did not appear to impact on driver seat belt use. The four research methods found taxi drivers to have consistently low "correct wearing" rates. As in several other countries, taxi drivers are particularly resistant to seat belt use. Innovative strategies, including occupational health and safety approaches, may be required to achieve increased levels of seat belt use.

  20. Bioplastics from feather quill.

    Science.gov (United States)

    Ullah, Aman; Vasanthan, Thavaratnam; Bressler, David; Elias, Anastasia L; Wu, Jianping

    2011-10-10

    Poultry feather quills have been extruded in a twin screw extruder with sodium sulfite treatment as a reducing agent. The effect of four different plasticizers (ethylene glycol, propylene glycol, glycerol, and diethyl tartrate) on the thermoplastic properties was then investigated. Conformational changes and plasticizer-protein interactions in the extruded resins were assessed by Fourier transform infrared spectroscopy (FTIR), while viscoelastic behavior of the quill keratin plasticized with different plasticizers was investigated by dynamic mechanical analysis (DMA). Differential scanning calorimetry (DSC) was used to determine the effect of different plasticizers on protein denaturation. Thermal degradation patterns of the extrudates were studied by thermogravimetric analysis (TGA). The effect of plasticizers on the mechanical properties of resins was also assessed by tensile strength measurements. Results indicated that ethylene glycol was able to interact more effectively with quill keratin at the molecular level, exhibiting only one sharp glass transition, better mechanical properties, and higher transparency compared to other plasticized resins. The two phases found in glycerol plasticized material were attributed to glycerol-rich and protein-rich zones. Propylene glycol and diethyl tartrate exhibited lower H-bonding interactions and showed wide transition regions in DMA profiles during heating, suggesting weak and heterogeneous interactions between quill keratin and these plasticizers.

  1. Gliding swifts attain laminar flow over rough wings.

    Directory of Open Access Journals (Sweden)

    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.

  2. Collaborative Outbound Taxi Metering for Environmental Benefits, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the concept of Collaborative Outbound Taxi Metering (COTM), which provides environmental benefits without sacrificing throughput. In current...

  3. Feather quill knobs in the dinosaur Velociraptor.

    Science.gov (United States)

    Turner, Alan H; Makovicky, Peter J; Norell, Mark A

    2007-09-21

    Some nonavian theropod dinosaurs were at least partially covered in feathers or filamentous protofeathers. However, a complete understanding of feather distribution among theropod dinosaurs is limited because feathers are typically preserved only in lagerstätten like that of Solnhofen, Germany or Liaoning, China. Such deposits possess clear taphonomic biases toward small-bodied animals, limiting our knowledge regarding feather presence in larger members of feathered clades. We present direct evidence of feathers in Velociraptor mongoliensis based on the presence of quill knobs on the posterior forearm. This report of secondaries in a larger-bodied, derived, and clearly flightless member of a nonavian theropod clade represented by feathered relatives is a substantial contribution to our knowledge of the evolution of feathers.

  4. The impact of rainfall on the temporal and spatial distribution of taxi passengers

    OpenAIRE

    Chen, Dandan; Zhang, Yong; Gao, Liangpeng; Geng, Nana; Li, Xuefeng

    2017-01-01

    This paper focuses on the impact of rainfall on the temporal and spatial distribution of taxi passengers. The main objective is to provide guidance for taxi scheduling on rainy days. To this end, we take the occupied and empty states of taxis as units of analysis. By matching a taxi's GPS data to its taximeter data, we can obtain the taxi's operational time and the taxi driver's income from every unit of analysis. The ratio of taxi operation time to taxi drivers' income is used to measure the...

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

    OpenAIRE

    di Luca, Matteo; Mintchev, Stefano; Heitz, Grégoire Hilaire Marie; Noca, Flavio; Floreano, Dario

    2017-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Health assessment of taxi drivers in the city of Tshwane

    Directory of Open Access Journals (Sweden)

    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.

  9. 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, ...

  10. [Taxi driver--film portrait of the insomniac].

    Science.gov (United States)

    Skårderud, Finn

    2009-09-10

    Martin Scorsese's film "Taxi Driver" from 1976 is a cinematic masterpiece. The main character cannot sleep. His condition is caused by inner restlessness and external commotion. The film shows us New York City's brutal nightlife through the distorted mind of a taxi driver.

  11. Three-wheeled scooter taxi: A safety analysis

    Indian Academy of Sciences (India)

    -wheel diesel-powered taxis (the so-called 'baby-taxis') account for more than one-third of the total number of kilometers traveled by all vehicles. In Bangkok 7,400 three-wheelers (the so-called. 'tuk-tuks') powered by LPG were on the roads.

  12. [The clinical analysis of 51 taxi drivers with peptic ulcer].

    Science.gov (United States)

    Luo, Wen-wen; Zhao, Jie; Fu, Yun-xian; Ma, A-huo

    2012-02-01

    To explore the main pathogenic factor causing the peptic ulcer of taxi drivers, which provide the basis for its prevention. 98 taxi drivers were inspected by electronic endoscopy, according to the inspection all cases were divided into ulcers group and normal group. Then various factors were statuses by the logistic regression analysis according to the results of questionnaire. The prevalence of peptic ulcer of taxi drivers was 52.0%, and logistic regression analysis showed that dining time, taste spicy, meals temperature, smoking,alcohol, mental stress, HP infection and stomach health knowledge were statistically significant (P taxi drivers. By emphasis on diet and lifestyle adjustments, stress regulation on the basis of eradication of HP infection will help the prevention and treatment of peptic ulcer of the taxi driver.

  13. Eagle Feathers, the Highest Honor.

    Science.gov (United States)

    Beaverhead, Pete

    Following his own advice that elders of the tribe share their knowledge so that "the way of the Indians would come back to the children of today," Pete Beaverhead (1899-1975) tells of the traditions of respect and honor surrounding the eagle feather in a booklet illustrated with black and white drawings. The eagle is an Indian symbol of…

  14. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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

  17. 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.

  18. 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

  19. Multi-features taxi destination prediction with frequency domain processing.

    Science.gov (United States)

    Zhang, Lei; Zhang, Guoxing; Liang, Zhizheng; Ozioko, Ekene Frank

    2018-01-01

    The traditional taxi prediction methods model the taxi trajectory as a sequence of spatial points. It cannot represent two-dimensional spatial relationships between trajectory points. Therefore, many methods transform the taxi GPS trajectory into a two-dimensional image, and express the spatial correlations by trajectory image. However, the trajectory image may have noise and sparsity according to trajectory data characteristics. So, we import image frequency domain processing to taxi destination prediction to reduce noise and sparsity, then propose multi-features taxi destination prediction with frequency domain processing (MTDP-FD) method. Firstly, we transform the spatial domain trajectory image into frequency-domain representation by fast Fourier transform and reduce the noise of the trajectory images. Convolutional Neural Network (CNN) is adapted to extract the deep features from the processed trajectory image as CNN has a significant learning ability to images. Recurrent Neural Network (RNN) is adapted to predict the taxi destination as multiple hidden layers of RNN can store dependencies between input data to achieve better prediction. The deep features of the trajectory images are combined with trajectory metadata, trajectory data to act as the input to RNN. The experiments based on the taxi trajectory dataset of Porto show that the average distance error of MTDP-FD is reduced by 0.14km compared with the existing methods, and the GTOHL is the best combination of data and features to improve the prediction accuracy.

  20. Taxi Driver’s Operation Behavior and Passengers’ Demand Analysis Based on GPS Data

    OpenAIRE

    Hu, Xiaowei; An, Shi; Wang, Jian

    2018-01-01

    The existing research outputs paid less attention to the relationship between land use and passenger demand, while the taxi drivers’ searching behavior for different lengths of observation period has not been explored. This paper is based on taxi GPS trajectories data from Shenzhen to explore taxi driver’s operation behavior and passengers’ demand. The taxi GPS trajectories data covers 204 hours in Shenzhen, China, which includes the taxi license number, time, longitude, latitude, speed, and ...

  1. 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

  2. Optical tweezers for studying taxis in parasites

    International Nuclear Information System (INIS)

    De Thomaz, A A; Pozzo, L Y; Almeida, D B; Cesar, C L; Fontes, A; Farias, P M A; Stahl, C V; Santos-Mallet, J; Gomes, S A O; Ayres, D C; Giorgio, S; Santos, B S; Feder, D

    2011-01-01

    In this work we present a methodology to measure force strengths and directions of living parasites with an optical tweezers setup. These measurements were used to study the parasites chemotaxis in real time. We observed behavior and measured the force of: (i) Leishmania amazonensis in the presence of two glucose gradients; (ii) Trypanosoma cruzi in the vicinity of the digestive system walls, and (iii) Trypanosoma rangeli in the vicinity of salivary glands as a function of distance. Our results clearly show a chemotactic behavior in every case. This methodology can be used to study any type of taxis, such as chemotaxis, osmotaxis, thermotaxis, phototaxis, of any kind of living microorganisms. These studies can help us to understand the microorganism sensory systems and their response function to these gradients

  3. Taxis toward hydrogen gas by Methanococcus maripaludis.

    Science.gov (United States)

    Brileya, Kristen A; Connolly, James M; Downey, Carey; Gerlach, Robin; Fields, Matthew W

    2013-11-05

    Knowledge of taxis (directed swimming) in the Archaea is currently expanding through identification of novel receptors, effectors, and proteins involved in signal transduction to the flagellar motor. Although the ability for biological cells to sense and swim toward hydrogen gas has been hypothesized for many years, this capacity has yet to be observed and demonstrated. Here we show that the average swimming velocity increases in the direction of a source of hydrogen gas for the methanogen, Methanococcus maripaludis using a capillary assay with anoxic gas-phase control and time-lapse microscopy. The results indicate that a methanogen couples motility to hydrogen concentration sensing and is the first direct observation of hydrogenotaxis in any domain of life. Hydrogenotaxis represents a strategy that would impart a competitive advantage to motile microorganisms that compete for hydrogen gas and would impact the C, S and N cycles.

  4. Health and safety strategies of urban taxi drivers.

    Science.gov (United States)

    Burgel, Barbara Jean; Gillen, Marion; White, Mary Castle

    2012-08-01

    This study describes health and safety concerns and self-care strategies of San Francisco taxi drivers. Focus groups and a written cross-sectional survey were done in a convenience sample of taxi drivers working in San Francisco. Sessions were audiotaped, transcribed in English, and independently coded to identify major health and safety themes, using thematic content analysis. Strategies to manage health and safety issues are the focus of this analysis. Five focus groups were held in 2009 with 36 participants. Major health and safety themes included stress, body pain, danger, vulnerable employment status, and concerns related to unhealthy working conditions. Self-care strategies included diffusion/decompression to manage stress, maintaining a positive attitude, maintaining power and control, and practicing proactive self-care. Creative self-care strategies were described by taxi drivers to keep healthy and safe at work. These data will inform future self-care interventions to reduce health and safety risks of taxi driving.

  5. Hubungan Upah dan Penawaran Tenaga Kerja Supir Taxi di Surabaya

    Directory of Open Access Journals (Sweden)

    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%.

  6. Challenges of Developing a Taxonomic Information System (Taxis ...

    African Journals Online (AJOL)

    TAXIS). Information was collected about the taxonomy, important uses and dangers associated with use/misuse of 118 medicinal plant species indigenous to South Western Nigeria. Photographs of 21 out of the 118 species were also collected ...

  7. Individual consistency of feather pecking behavior in laying hens: once a feather pecker always a feather pecker?

    NARCIS (Netherlands)

    Daigle, C.L.; Rodenburg, T.B.; Bolhuis, J.E.; Swanson, J.C.; Siegford, J.M.

    2015-01-01

    The pecking behavior [severe feather, gentle feather, and aggressive pecks (AP)] of individual White Shaver non-cage laying hens (n = 300) was examined at 21, 24, 27, 32, and 37 weeks. Hens were housed in 30 groups of 10 hens each and on 3 cm litter with access to a feeder, perch, and two nest

  8. Research on Taxi Driver Strategy Game Evolution with Carpooling Detour

    OpenAIRE

    Zhang, Wei; He, Ruichun; Ma, Changxi; Gao, Mingxia

    2018-01-01

    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 carpoolin...

  9. 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

  10. 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.

  11. Analyzing Impact Factors of Airport Taxiing Delay Based on Ads-B Data

    Science.gov (United States)

    Li, J.; Wang, X.; Xu, Y.; Li, Q.; He, C.; Li, Y.

    2017-09-01

    Identifying the factors that cause taxiing delay on airports is a prerequisite for optimizing aircraft taxiing schemes, and helps improve the efficiency of taxiing system. Few of current studies had quantified the potential influencing factors and further investigated their intrinsic relationship. In view of these problems, this paper uses ADS-B data to calculate taxiing delay time by restoring taxiing route and identifying key status points, and further analyzes the impact factors of airport taxiing delay by investigating the relationship between delay time and environmental data such as weather, wind, visibility etc. The case study in Guangzhou Baiyun Airport validates the effectiveness of the proposed method.

  12. Repeated adaptive divergence of microhabitat specialization in avian feather lice

    Directory of Open Access Journals (Sweden)

    Johnson Kevin P

    2012-06-01

    Full Text Available Abstract Background Repeated adaptive radiations are evident when phenotypic divergence occurs within lineages, but this divergence into different forms is convergent when compared across lineages. Classic examples of such repeated adaptive divergence occur in island (for example, Caribbean Anolis lizards and lake systems (for example, African cichlids. Host-parasite systems in many respects are analogous to island systems, where host species represent isolated islands for parasites whose life cycle is highly tied to that of their hosts. Thus, host-parasite systems might exhibit interesting cases of repeated adaptive divergence as seen in island and lake systems. The feather lice of birds spend their entire life cycle on the body of the host and occupy distinct microhabitats on the host: head, wing, body and generalist. These microhabitat specialists show pronounced morphological differences corresponding to how they escape from host preening. We tested whether these different microhabitat specialists were a case of repeated adaptive divergence by constructing both morphological and molecular phylogenies for a diversity of avian feather lice, including many examples of head, wing, body and generalist forms. Results Morphological and molecular based phylogenies were highly incongruent, which could be explained by rampant convergence in morphology related to microhabitat specialization on the host. In many cases lice from different microhabitat specializations, but from the same group of birds, were sister taxa. Conclusions This pattern indicates a process of repeated adaptive divergence of these parasites within host group, but convergence when comparing parasites across host groups. These results suggest that host-parasite systems might be another case in which repeated adaptive radiations could be relatively common, but potentially overlooked, because morphological convergence can obscure evolutionary relationships.

  13. Taxi Cab Syndrome: A Review of the Extensive Genitourinary Pathology Experienced by Taxi Cab Drivers and What We Can Do to Help

    Science.gov (United States)

    Mass, Alon Y; Goldfarb, David S; Shah, Ojas

    2014-01-01

    This review consolidates knowledge regarding the extensive genitourinary pathology experienced by taxi cab drivers. Taxi cab, livery, truck, and other drivers all objectively and subjectively may have more voiding dysfunction, infertility, urolithiasis, bladder cancer, and urinary infections as compared with nonprofessional drivers; this is called taxi cab syndrome. Together with governmental and medical assistance, simple interventions—such as education, the addition of taxi relief stations, and possibly the use of sanitary urinary collection devices—to curb the progression of genitourinary disease in taxi drivers should be prospectively studied. It is postulated that many of these interventions may also benefit other groups of occupationally related infrequent voiders. PMID:25337038

  14. Effects of small increases in corticosterone levels on morphology, immune function, and feather development.

    Science.gov (United States)

    Butler, Michael W; Leppert, Lynda L; Dufty, Alfred M

    2010-01-01

    Stressors encountered during avian development may affect an individual's phenotype, including immunocompetence, growth, and feather quality. We examined effects of simulated chronic low-level stress on American kestrel (Falco sparverius) nestlings. Continuous release of corticosterone, a hormone involved in the stress response, can model chronic stress in birds. We implanted 13-d-old males with either corticosterone-filled implants or shams and measured their growth, immune function, and feather coloration. We found no significant differences between groups at the end of the weeklong exposure period in morphometrics (mass, tarsus, wing length, and asymmetry), immunocompetence (cutaneous immunity, heterophil/lymphocyte ratio, and humoral immunity), or feather coloration. One week subsequent to implant removal, however, differences were detected. Sham-implanted birds had significantly longer wings and a reduced level of cutaneous immune function compared with those of birds given corticosterone-filled implants. Therefore, increases of only 2 ng/mL in basal corticosterone titer can have small but measurable effects on subsequent avian development.

  15. A new Jurassic theropod from China documents a transitional step in the macrostructure of feathers

    Science.gov (United States)

    Lefèvre, Ulysse; Cau, Andrea; Cincotta, Aude; Hu, Dongyu; Chinsamy, Anusuya; Escuillié, François; Godefroit, Pascal

    2017-10-01

    Genuine fossils with exquisitely preserved plumage from the Late Jurassic and Early Cretaceous of northeastern China have recently revealed that bird-like theropod dinosaurs had long pennaceous feathers along their hindlimbs and may have used their four wings to glide or fly. Thus, it has been postulated that early bird flight might initially have involved four wings (Xu et al. Nature 421:335-340, 2003; Hu et al. Nature 461:640-643, 2009; Han et al. Nat Commun 5:4382, 2014). Here, we describe Serikornis sungei gen. et sp. nov., a new feathered theropod from the Tiaojishan Fm (Late Jurassic) of Liaoning Province, China. Its skeletal morphology suggests a ground-dwelling ecology with no flying adaptations. Our phylogenetic analysis places Serikornis, together with other Late Jurassic paravians from China, as a basal paravians, outside the Eumaniraptora clade. The tail of Serikornis is covered proximally by filaments and distally by slender rectrices. Thin symmetrical remiges lacking barbules are attached along its forelimbs and elongate hindlimb feathers extend up to its toes, suggesting that hindlimb remiges evolved in ground-dwelling maniraptorans before being co-opted to an arboreal lifestyle or flight.

  16. Effects of stocking density on feather pecking and aggressive behavior in Thai crossbred chickens

    Directory of Open Access Journals (Sweden)

    Xin Huo

    2016-09-01

    Full Text Available The influence of stocking density on feather pecking and aggressive behavior of Thai crossbred chickens was investigated from age 4–12 wk. In total, 900 day-old mixed sex Thai crossbred chickens were assigned to three replicates of 100 birds per pen, at stocking densities of 8 birds/m2, 12 birds/m2 and 16 birds/m2, respectively. The frequency of feather pecking, the number of pecks per bout, pecking intensity and the frequency of aggressive behavior were recorded once a week by scanning all the birds in the pen. It was found that the stocking density had no effect on the frequencies of feather pecking on body areas except on the wings area (p < 0.05. The stocking density had no effect on the occurrence of 1–4 pecks per bout or 5–9 pecks per bout. The stocking density had no significant influence on the pecking, pinching or plucking intensity, except on the intensity of pulling. The different types of aggressive behavior such as stand-off, fight, threat, leap, chase, avoidance and peck were not affected by the stocking density. In conclusion, stocking density did not affect the feather pecking activities and aggressive behavior of Thai crossbred chickens. However, further work is suggested with a larger number of replications to establish that there is no effect of stocking density, as the power of this study was low.

  17. 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

  18. 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...

  19. 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.

  20. A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings.

    Science.gov (United States)

    Xu, Xing; Zheng, Xiaoting; Sullivan, Corwin; Wang, Xiaoli; Xing, Lida; Wang, Yan; Zhang, Xiaomei; O'Connor, Jingmai K; Zhang, Fucheng; Pan, Yanhong

    2015-05-07

    The wings of birds and their closest theropod relatives share a uniform fundamental architecture, with pinnate flight feathers as the key component. Here we report a new scansoriopterygid theropod, Yi qi gen. et sp. nov., based on a new specimen from the Middle-Upper Jurassic period Tiaojishan Formation of Hebei Province, China. Yi is nested phylogenetically among winged theropods but has large stiff filamentous feathers of an unusual type on both the forelimb and hindlimb. However, the filamentous feathers of Yi resemble pinnate feathers in bearing morphologically diverse melanosomes. Most surprisingly, Yi has a long rod-like bone extending from each wrist, and patches of membranous tissue preserved between the rod-like bones and the manual digits. Analogous features are unknown in any dinosaur but occur in various flying and gliding tetrapods, suggesting the intriguing possibility that Yi had membranous aerodynamic surfaces totally different from the archetypal feathered wings of birds and their closest relatives. Documentation of the unique forelimbs of Yi greatly increases the morphological disparity known to exist among dinosaurs, and highlights the extraordinary breadth and richness of the evolutionary experimentation that took place close to the origin of birds.

  1. pH-Taxis of Biohybrid Microsystems

    Science.gov (United States)

    Zhuang, Jiang; Wright Carlsen, Rika; Sitti, Metin

    2015-06-01

    The last decade has seen an increasing number of studies developing bacteria and other cell-integrated biohybrid microsystems. However, the highly stochastic motion of these microsystems severely limits their potential use. Here, we present a method that exploits the pH sensing of flagellated bacteria to realize robust drift control of multi-bacteria propelled microrobots. Under three specifically configured pH gradients, we demonstrate that the microrobots exhibit both unidirectional and bidirectional pH-tactic behaviors, which are also observed in free-swimming bacteria. From trajectory analysis, we find that the swimming direction and speed biases are two major factors that contribute to their tactic drift motion. The motion analysis of microrobots also sheds light on the propulsion dynamics of the flagellated bacteria as bioactuators. It is expected that similar driving mechanisms are shared among pH-taxis, chemotaxis, and thermotaxis. By identifying the mechanism that drives the tactic behavior of bacteria-propelled microsystems, this study opens up an avenue towards improving the control of biohybrid microsystems. Furthermore, assuming that it is possible to tune the preferred pH of bioactuators by genetic engineering, these biohybrid microsystems could potentially be applied to sense the pH gradient induced by cancerous cells in stagnant fluids inside human body and realize targeted drug delivery.

  2. 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...

  3. Kwazulu-Natal minibus taxi drivers' perceptions on HIV and AIDS ...

    African Journals Online (AJOL)

    Gugu Mchunu, Busisiwe Ncama, Joanne Rachel Naidoo, Sisana Majeke, Thandazile Myeza, Thandiwe Ndebele, and Padmini Pillay

    prevention strategies, existing support strategies and effects of HIV and AIDS on the taxi industry. ... industry. Keywords: HIV and AIDS, mini bus taxi drivers. Résumé. En Afrique du Sud, les chauffeurs de taxi-minibus sont en train de devenir en grande partie une autre ... workers, truck drivers and pregnant women (Morisky,.

  4. Semen profiles of young men involved as bicycle taxi cyclists in ...

    African Journals Online (AJOL)

    Aim The purpose of this study was to evaluate the semen profiles of bicycle taxi cyclists and healthy controls in Mangochi district, Malawi. Methods Semen samples were collected from young bicycle taxi cyclists after two to three days of sexual abstinence. A control group, comprising young men who were not bicycle taxi ...

  5. 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.

  6. Disability and motorcycle taxi drivers in Cartagena, Colombia

    Directory of Open Access Journals (Sweden)

    Yaneth Herazo B

    2011-11-01

    Full Text Available Objective: to estimate the functional dependency as a measure of disability in a group of motorcycle taxi drivers from Cartagena, Colombia. Methods: a retrospective descriptive study in which researchers reviewed 1123 files of motorcycle taxi drivers involved in traffic accidents in Cartagena during 2006. The level of functional dependence regarding performance of some basic activities of daily life was determined for 262 subjects using the Barthel scale. Furthermore, data analysis was carried out using the EpiInfo 3.5.1 database, and variables are presented in absolute and relative frequencies. Results: it was found that 53.4% of subjects had mild functional dependence and 15.6% had moderate dependence. 76% of the participants said they were unemployed. Conclusions: functional dependence as a measure of disability is a highly probable result of traffic accidents among motorcycle taxi drivers.

  7. Pilot Age and Error in Air-Taxi Crashes

    Science.gov (United States)

    Rebok, George W.; Qiang, Yandong; Baker, Susan P.; Li, Guohua

    2010-01-01

    Introduction The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air-taxi crashes. Methods Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Results Of the 1751 air-taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air-taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. Conclusions Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air-taxi crashes. Lack of age-related differences in pilot error may be attributable to the “safe worker effect.” PMID:19601508

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 77 FR 20789 - Work Group on Measuring Systems for Taxis

    Science.gov (United States)

    2012-04-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Institute of Standards and Technology Work Group on Measuring Systems for Taxis AGENCY: National... Standards and Technology (NIST) is forming a Work Group (WG) to develop proposals to revise the current...

  13. Exploring anterograde associative memory in London taxi drivers

    Science.gov (United States)

    Woollett, Katherine; Maguire, Eleanor A.

    2013-01-01

    London taxi drivers are renowned for their navigation ability, spending a number of years acquiring ‘The Knowledge’ of London’s complex layout and having to pass stringent examinations to obtain an operating licence. In several studies, this navigation skill has been associated with increased posterior but also decreased anterior hippocampal grey matter volume. Neuropsychologically, gain and loss has also been documented in taxi drivers; while very skilled at navigation in London, they are significantly poorer than controls at learning and recalling new object-location associations. Here we tested a group of London taxi drivers and matched control participants on this object-location associations task, while also submitting them to a battery of challenging anterograde associative memory tests involving verbal, visual and auditory material both within and across modalities. Our aim was to assess whether their difficulty in previous studies reflected a general problem with associative memory, or was restricted to the spatial domain. We replicated previous findings of poor learning and memory of object-location associations. By contrast, their performance on the other anterograde associative memory tasks was comparable to controls. This resolves an outstanding question in the memory profile of London taxi drivers following hippocampal plasticity, and underlines the close relationship between space and the hippocampus. PMID:22955143

  14. Transcendence, Taxis, Trust: Richard Kearney and Jacques Derrida

    Directory of Open Access Journals (Sweden)

    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.

  15. Three-wheeled scooter taxi: A safety analysis

    Indian Academy of Sciences (India)

    1Transportation Research and Injury Prevention Programme, Indian Institute of. Technology, Hauz Khas, New Delhi 110 016. 2TVS Motors Ltd, Hosur, Bangalore 635 109 e-mail: sudipto@me.iitd.ernet.in. Abstract. The rollover propensity of a three-wheeled scooter taxi used extensively on SE Asian roads is analysed in this ...

  16. 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)

  17. Hematological changes among Beninese motor-bike taxi drivers ...

    African Journals Online (AJOL)

    user

    monitoring of low level benzene exposure. Larger studies are however required to validate this new approach of health survey in workers exposed to benzene. Key words: Benzene, motor-bike-taxi drivers, specific immune responses, peripheral blood cell count. INTRODUCTION. Urban air pollution is a major health hazard ...

  18. (LBP) among Taxi Drivers in Addis Ababa, Ethiopia

    African Journals Online (AJOL)

    user

    Original article. Prevalence and risk factors for low back pain (LBP) among. Taxi Drivers in Addis Ababa, Ethiopia: A community based cross-sectional study. Melaku Erjabo Wanamo, Samson ... cultural contribute (1). Lower back which is also ... burden on individuals' families, communities, industries and countries (6, 7).

  19. 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

  20. Occupational health risks and intervention strategies for US taxi drivers.

    Science.gov (United States)

    Murray, Kate E; Buul, Abdimalik; Aden, Rasheed; Cavanaugh, Alyson M; Kidane, Luwam; Hussein, Mikaiil; Eastman, Amelia; Checkoway, Harvey

    2017-12-02

    Research has shown that taxi drivers are at risk for numerous health concerns, such as low back and leg pain, linked to their highly sedentary occupation, long work hours and stressors related to the job (e.g. low income, safety threats). The goal of this study was to explore occupational health risks and opportunities for health interventions with taxi drivers using community-based participatory research (CBPR) methods. A mixed methods approach included first a convenience sample of 19 East African taxi drivers participating in focus group discussions. Second, a convenience sample of 75 current taxi drivers (M age = 45.7 years) and 25 non-driver comparison participants (M age = 40.3 years) were recruited to complete a structured self-reported questionnaire and objective measures of health. Health education was provided alongside the research to address common health concerns and to ensure mutual benefit and an action orientation. The focus groups described numerous health concerns that drivers attributed to their occupation, including chronic pain, sleep deprivation, cardiovascular disease, diabetes, kidney disease and eye problems, as the most common. Participants offered ideas for health interventions that include workplace reform and driver education. Quantitative data indicate that 44% of drivers reported their health as 'fair' or 'poor'. Drivers were more likely to report musculoskeletal pain, less sleep, more fatigue and less physical activity as compared to non-drivers. The majority of drivers reported financial and job dissatisfaction. The research provides data to inform targeted health interventions that support the health and safety of taxi drivers. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. 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...

  2. Dexamethasone inhibits corticosterone deposition in feathers of greenfinches.

    Science.gov (United States)

    Hõrak, Peeter; Männiste, Marju; Meitern, Richard; Sild, Elin; Saks, Lauri; Sepp, Tuul

    2013-09-15

    Corticosterone (CORT) content of feathers is a potent source of information about activation of hypothalamus-pituitary-adrenal (HPA) axis during feather growth, which is used for assessment of well-being and stress history of individuals and populations in avian studies. However, little is known about factors affecting deposition of CORT into feathers and how feather CORT covaries with other markers of stress imposed upon individuals during feather growth. We addressed these questions by measuring CORT levels in feathers of wild-caught greenfinches (Carduelis chloris) brought into captivity. One tail feather was removed from all the birds upon arrival to the laboratory and the CORT levels of replacement feathers, grown in captivity were recorded. The birds were subjected to treatments of immune activation (by injection of phytohaemagglutinin) and synthetic glucocorticoid (dexamethasone, DEX) administration. Only DEX injection affected feather CORT levels. DEX-injected birds deposited on average 37% less of CORT in their feathers than saline-injected birds. Despite significant effects of DEX and immune activation treatments on differential leukocyte counts, we did not find any correlations between CORT and leukocyte hemoconcentrations or heterophil/lymphocyte ratios (a haematological index of stress), measured at three stages of feather growth. Our findings provide novel evidence that feather CORT levels are sensitive to manipulation of hormonal balance of birds, thereby supporting the diagnostic value of feather CORT measurements. However, we did not find any evidence about covariation between feather CORT and other markers of stress perceived during the period of feather growth. This calls for further research on information content of feather CORT, preferably in experiments manipulating more diverse array of psychological, immunological and abiotic stressors. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. 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.

  4. Characteristics of coronary heart disease in Japanese taxi drivers as determined by coronary angiographic analyses.

    Science.gov (United States)

    Kurosaka, K; Daida, H; Muto, T; Watanabe, Y; Kawai, S; Yamaguchi, H

    2000-01-01

    Several epidemiological studies have shown that the prevalence of ischemic heart disease is higher in occupational drivers than in people with other occupations. Although occupation categories can be surrogate measures for coronary risk factors, the relationships between taxi driving and severity of coronary heart disease (CHD) has not been investigated. Even more important, the contribution of risk factors to the severity of CHD in taxi drivers remains unclear. Our study tested the hypothesis that taxi driving could be associated with the severity of CHD. We also examined the relation between this occupation and risk factors and social lifestyle. We analyzed the coronary angiograms of 57 consecutive male taxi driver patients and compared them with those of 215 age-adjusted male non-taxi-driver patients. The number of diseased vessels and risk factors were compared between two groups. The prevalence of myocardial infarction and multi-vessel disease was higher in the taxi-driver patients than in the non-taxi-driver patients. The taxi-driver patients had higher prevalence of body mass index (BMI), diabetes, and smoking, higher levels of low-density lipoprotein cholesterol (LDL-C), and lower levels of apolipoprotein AI (ApoAI). Multiple logistic regression analysis showed that multi-vessel disease was associated with BMI and diabetes mellitus in taxi-driver patients. The taxi-driver patients were characterized by more extensive coronary atherosclerosis associated with higher prevalence of diabetes mellitus and obesity. These characteristics may be explained by in part their working environment.

  5. 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

  6. 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.

  7. 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...

  8. Stabilization of solutions of feather keratins by sodium dodecyl sulphate

    NARCIS (Netherlands)

    Schrooyen, P.M.M.; Dijkstra, Pieter J.; Oberthür, Radulf C.; Bantjes, A.; Bantjes, Adriaan; Feijen, Jan

    2001-01-01

    Feather keratins were extracted from chicken feathers with aqueous solutions of urea and 2-mercaptoethanol. After filtration of the insoluble residue, a feather keratin solution was obtained. Removal of 2-mercaptoethanol and urea by dialysis resulted in aggregation of the keratin polypeptide chains

  9. 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 ...

  10. Alternative fish feed production from waste chicken feathers

    Directory of Open Access Journals (Sweden)

    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.

  11. Wing bone geometry reveals active flight in Archaeopteryx.

    Science.gov (United States)

    Voeten, Dennis F A E; Cubo, Jorge; de Margerie, Emmanuel; Röper, Martin; Beyrand, Vincent; Bureš, Stanislav; Tafforeau, Paul; Sanchez, Sophie

    2018-03-13

    Archaeopteryx is an iconic fossil taxon with feathered wings from the Late Jurassic of Germany that occupies a crucial position for understanding the early evolution of avian flight. After over 150 years of study, its mosaic anatomy unifying characters of both non-flying dinosaurs and flying birds has remained challenging to interpret in a locomotory context. Here, we compare new data from three Archaeopteryx specimens obtained through phase-contrast synchrotron microtomography to a representative sample of archosaurs employing a diverse array of locomotory strategies. Our analyses reveal that the architecture of Archaeopteryx's wing bones consistently exhibits a combination of cross-sectional geometric properties uniquely shared with volant birds, particularly those occasionally utilising short-distance flapping. We therefore interpret that Archaeopteryx actively employed wing flapping to take to the air through a more anterodorsally posteroventrally oriented flight stroke than used by modern birds. This unexpected outcome implies that avian powered flight must have originated before the latest Jurassic.

  12. Occupant-level injury severity analyses for taxis in Hong Kong: A Bayesian space-time logistic model.

    Science.gov (United States)

    Meng, Fanyu; Xu, Pengpeng; Wong, S C; Huang, Helai; Li, Y C

    2017-11-01

    This study aimed to identify the factors affecting the crash-related severity level of injuries in taxis and quantify the associations between these factors and taxi occupant injury severity. Casualties resulting from taxi crashes from 2004 to 2013 in Hong Kong were divided into four categories: taxi drivers, taxi passengers, private car drivers and private car passengers. To avoid any biased interpretation caused by unobserved spatial and temporal effects, a Bayesian hierarchical logistic modeling approach with conditional autoregressive priors was applied, and four different model forms were tested. For taxi drivers and passengers, the model with space-time interaction was proven to most properly address the unobserved heterogeneity effects. The results indicated that time of week, number of vehicles involved, weather, point of impact and driver age were closely associated with taxi drivers' injury severity level in a crash. For taxi passengers' injury severity an additional factor, taxi service area, was influential. To investigate the differences between taxis and other traffic, similar models were established for private car drivers and passengers. The results revealed that although location in the network and driver gender significantly influenced private car drivers' injury severity, they did not influence taxi drivers' injury severity. Compared with taxi passengers, the injury severity of private car passengers was more sensitive to average speed and whether seat belts were worn. Older drivers, urban taxis and fatigued driving were identified as factors that increased taxi occupant injury severity in Hong Kong. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. A bio-inspired study on tidal energy extraction with flexible flapping wings.

    Science.gov (United States)

    Liu, Wendi; Xiao, Qing; Cheng, Fai

    2013-09-01

    Previous research on the flexible structure of flapping wings has shown an improved propulsion performance in comparison to rigid wings. However, not much is known about this function in terms of power efficiency modification for flapping wing energy devices. In order to study the role of the flexible wing deformation in the hydrodynamics of flapping wing energy devices, we computationally model the two-dimensional flexible single and twin flapping wings in operation under the energy extraction conditions with a large Reynolds number of 106. The flexible motion for the present study is predetermined based on a priori structural result which is different from a passive flexibility solution. Four different models are investigated with additional potential local distortions near the leading and trailing edges. Our simulation results show that the flexible structure of a wing is beneficial to enhance power efficiency by increasing the peaks of lift force over a flapping cycle, and tuning the phase shift between force and velocity to a favourable trend. Moreover, the impact of wing flexibility on efficiency is more profound at a low nominal effective angle of attack (AoA). At a typical flapping frequency f * = 0.15 and nominal effective AoA of 10°, a flexible integrated wing generates 7.68% higher efficiency than a rigid wing. An even higher increase, around six times that of a rigid wing, is achievable if the nominal effective AoA is reduced to zero degrees at feathering condition. This is very attractive for a semi-actuated flapping energy system, where energy input is needed to activate the pitching motion. The results from our dual-wing study found that a parallel twin-wing device can produce more power compared to a single wing due to the strong flow interaction between the two wings.

  14. Light oiling of feathers increases flight energy expenditure in a migratory shorebird.

    Science.gov (United States)

    Maggini, Ivan; Kennedy, Lisa V; Macmillan, Alexander; Elliott, Kyle H; Dean, Karen; Guglielmo, Christopher G

    2017-07-01

    Flying birds depend on their feathers to undertake most activities, and maintain them in peak condition through periodic molt and frequent preening. Even small exposures to crude oil reduce the integrity of feathers, and could impair flight performance. We trained wild western sandpipers ( Calidris mauri ) to perform endurance flights in a wind tunnel, and used magnetic resonance body composition analysis to measure energy expenditure after birds were exposed to weathered MC252 crude oil from the Deepwater Horizon oil spill. The cost of transport was 0.26±0.04 kJ km -1 in controls, and increased by 22% when the trailing edges of the wing and tail were oiled (flight control, and only half of moderately oiled birds completed the flight test. We then flew birds at a range of speeds to estimate basic kinematic parameters. At low speeds, light and moderately oiled birds had larger wingbeat amplitudes than controls, while moderately oiled birds showed greater wingbeat frequencies across all speeds, and a shift in optimal flight speed towards higher wind speeds. We suggest these changes reflect poorer lift production and increased drag on the wings and body. Oiling will increase the difficulty and energy costs of locomotion for daily and seasonal activities such as foraging, predator evasion, territory defense, courtship, chick provisioning, commuting and long-distance migration. These sub-lethal effects must be considered in oil spill impact assessments. © 2017. Published by The Company of Biologists Ltd.

  15. Aerodynamic Characteristics of a Feathered Dinosaur Measured Using Physical Models. Effects of Form on Static Stability and Control Effectiveness

    Science.gov (United States)

    Evangelista, Dennis; Cardona, Griselda; Guenther-Gleason, Eric; Huynh, Tony; Kwong, Austin; Marks, Dylan; Ray, Neil; Tisbe, Adrian; Tse, Kyle; Koehl, Mimi

    2014-01-01

    We report the effects of posture and morphology on the static aerodynamic stability and control effectiveness of physical models based on the feathered dinosaur, Microraptor gui, from the Cretaceous of China. Postures had similar lift and drag coefficients and were broadly similar when simplified metrics of gliding were considered, but they exhibited different stability characteristics depending on the position of the legs and the presence of feathers on the legs and the tail. Both stability and the function of appendages in generating maneuvering forces and torques changed as the glide angle or angle of attack were changed. These are significant because they represent an aerial environment that may have shifted during the evolution of directed aerial descent and other aerial behaviors. Certain movements were particularly effective (symmetric movements of the wings and tail in pitch, asymmetric wing movements, some tail movements). Other appendages altered their function from creating yaws at high angle of attack to rolls at low angle of attack, or reversed their function entirely. While M. gui lived after Archaeopteryx and likely represents a side experiment with feathered morphology, the general patterns of stability and control effectiveness suggested from the manipulations of forelimb, hindlimb and tail morphology here may help understand the evolution of flight control aerodynamics in vertebrates. Though these results rest on a single specimen, as further fossils with different morphologies are tested, the findings here could be applied in a phylogenetic context to reveal biomechanical constraints on extinct flyers arising from the need to maneuver. PMID:24454820

  16. 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.

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

    Science.gov (United States)

    Heitz, G.; Noca, F.; Floreano, D.

    2017-01-01

    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. PMID:28163882

  18. 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.

  19. 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.

  20. 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.

  1. The scaling of human mobility by taxis is exponential

    Science.gov (United States)

    Liang, Xiao; Zheng, Xudong; Lv, Weifeng; Zhu, Tongyu; Xu, Ke

    2012-03-01

    As a significant factor in urban planning, traffic forecasting and prediction of epidemics, modeling patterns of human mobility draws intensive attention from researchers for decades. Power-law distribution and its variations are observed from quite a few real-world human mobility datasets such as the movements of banking notes, trackings of cell phone users' locations and trajectories of vehicles. In this paper, we build models for 20 million trajectories with fine granularity collected from more than 10 thousand taxis in Beijing. In contrast to most models observed in human mobility data, the taxis' traveling displacements in urban areas tend to follow an exponential distribution instead of a power-law. Similarly, the elapsed time can also be well approximated by an exponential distribution. Worth mentioning, analysis of the interevent time indicates the bursty nature of human mobility, similar to many other human activities.

  2. 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.

  3. 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.

  4. 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...... not differ in their fear responses. Divergent selection on feather pecking may have altered pecking motivation rather than fearfulness....

  5. High feather corticosterone indicates better coccidian infection resistance in greenfinches.

    Science.gov (United States)

    Sild, Elin; Meitern, Richard; Männiste, Marju; Karu, Ulvi; Hõrak, Peeter

    2014-08-01

    Differential exposure or sensitivity to stressors can have substantial effects on the variation in immune responsiveness of animals. However, the questions about the causes and consequences of these processes have remained largely unclear, particularly as regards wild animals and their natural pathogens. Here we ask how a potential marker of stress responses, the feather corticosterone (CORT) content, reflects the resistance to an experimental infection with natural coccidian parasites in wild-caught captive greenfinches (Carduelis chloris). CORT content of tail feathers grown in captivity correlated positively with a behavioural measure of captivity-intolerance, i.e., the amount of damage accrued to tail feathers in captivity that results from flapping against cage bars. This finding is consistent with an idea that feather CORT reflects the amount of stress experienced during feather growth. Experimental infection with heterologous coccidian strains increased feather CORT levels. Birds with highest feather CORT levels appeared most resistant to new infection, assessed on the basis of parasite oocyst shedding at the peak phase of infection. Birds with highest feather CORT levels also cleared the infection faster than the birds with lower feather CORT levels. These findings provide the first evidence about positive covariation between feather CORT and resistance to a natural pathogen in a wild bird species. Assuming that feather CORT levels reflect circulating hormone titres, these findings suggest that parasite-mediated selection may contribute to maintenance of phenotypes with high corticosterone responsiveness to stress, despite potential negative behavioural consequences. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. 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.

  7. 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.

  8. Salmonella uses energy taxis to benefit from intestinal inflammation.

    Science.gov (United States)

    Rivera-Chávez, Fabian; Winter, Sebastian E; Lopez, Christopher A; Xavier, Mariana N; Winter, Maria G; Nuccio, Sean-Paul; Russell, Joseph M; Laughlin, Richard C; Lawhon, Sara D; Sterzenbach, Torsten; Bevins, Charles L; Tsolis, Renée M; Harshey, Rasika; Adams, L Garry; Bäumler, Andreas J

    2013-01-01

    Chemotaxis enhances the fitness of Salmonella enterica serotype Typhimurium (S. Typhimurium) during colitis. However, the chemotaxis receptors conferring this fitness advantage and their cognate signals generated during inflammation remain unknown. Here we identify respiratory electron acceptors that are generated in the intestinal lumen as by-products of the host inflammatory response as in vivo signals for methyl-accepting chemotaxis proteins (MCPs). Three MCPs, including Trg, Tsr and Aer, enhanced the fitness of S. Typhimurium in a mouse colitis model. Aer mediated chemotaxis towards electron acceptors (energy taxis) in vitro and required tetrathionate respiration to confer a fitness advantage in vivo. Tsr mediated energy taxis towards nitrate but not towards tetrathionate in vitro and required nitrate respiration to confer a fitness advantage in vivo. These data suggest that the energy taxis receptors Tsr and Aer respond to distinct in vivo signals to confer a fitness advantage upon S. Typhimurium during inflammation by enabling this facultative anaerobic pathogen to seek out favorable spatial niches containing host-derived electron acceptors that boost its luminal growth.

  9. 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.

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

    DEFF Research Database (Denmark)

    Barann, Benjamin; Beverungen, Daniel; Müller, Oliver

    2017-01-01

    Taxi ridesharing (TRS) is an advanced form of urban transportation that matches separate ride requests with similar spatio-temporal characteristics to a jointly used taxi. As collaborative consumption, TRS saves customers money, enables taxi companies to economize use of their resources, and lowers...... 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....

  11. Taxi Driver’s Operation Behavior and Passengers’ Demand Analysis Based on GPS Data

    Directory of Open Access Journals (Sweden)

    Xiaowei Hu

    2018-01-01

    Full Text Available The existing research outputs paid less attention to the relationship between land use and passenger demand, while the taxi drivers’ searching behavior for different lengths of observation period has not been explored. This paper is based on taxi GPS trajectories data from Shenzhen to explore taxi driver’s operation behavior and passengers’ demand. The taxi GPS trajectories data covers 204 hours in Shenzhen, China, which includes the taxi license number, time, longitude, latitude, speed, and whether passengers are in the taxi vehicle, to track the passenger’s pick-up and drop-off information. This paper focuses on these important topics: exploring the taxi driver operation behavior by the measurements of activity space and the connection between different activity spaces for different time duration; mainly focusing on eight traffic analysis zones (TAZs of Shenzhen and exploring the customer’s real-time origin and destination demands on a spatial-temporal distribution on weekdays and weekends; taxi station optimization based on the passenger demand and expected customer waiting time distribution. This research can be helpful for taxi drivers to search for a new passenger and passengers to more easily find a taxi’s location.

  12. Measuring and modeling air exchange rates inside taxi cabs in Los Angeles, California

    Science.gov (United States)

    Shu, Shi; Yu, Nu; Wang, Yueyan; Zhu, Yifang

    2015-12-01

    Air exchange rates (AERs) have a direct impact on traffic-related air pollutant (TRAP) levels inside vehicles. Taxi drivers are occupationally exposed to TRAP on a daily basis, yet there is limited measurement of AERs in taxi cabs. To fill this gap, AERs were quantified in 22 representative Los Angeles taxi cabs including 10 Prius, 5 Crown Victoria, 3 Camry, 3 Caravan, and 1 Uplander under realistic driving (RD) conditions. To further study the impacts of window position and ventilation settings on taxi AERs, additional tests were conducted on 14 taxis with windows closed (WC) and on the other 8 taxis with not only windows closed but also medium fan speed (WC-MFS) under outdoor air mode. Under RD conditions, the AERs in all 22 cabs had a mean of 63 h-1 with a median of 38 h-1. Similar AERs were observed under WC condition when compared to those measured under RD condition. Under WC-MFS condition, AERs were significantly increased in all taxi cabs, when compared with those measured under RD condition. A General Estimating Equation (GEE) model was developed and the modeling results showed that vehicle model was a significant factor in determining the AERs in taxi cabs under RD condition. Driving speed and car age were positively associated with AERs but not statistically significant. Overall, AERs measured in taxi cabs were much higher than typical AERs people usually encounter in indoor environments such as homes, offices, and even regular passenger vehicles.

  13. A Mixed Integer Linear Program for Solving a Multiple Route Taxi Scheduling Problem

    Science.gov (United States)

    Montoya, Justin Vincent; Wood, Zachary Paul; Rathinam, Sivakumar; Malik, Waqar Ahmad

    2010-01-01

    Aircraft movements on taxiways at busy airports often create bottlenecks. This paper introduces a mixed integer linear program to solve a Multiple Route Aircraft Taxi Scheduling Problem. The outputs of the model are in the form of optimal taxi schedules, which include routing decisions for taxiing aircraft. The model extends an existing single route formulation to include routing decisions. An efficient comparison framework compares the multi-route formulation and the single route formulation. The multi-route model is exercised for east side airport surface traffic at Dallas/Fort Worth International Airport to determine if any arrival taxi time savings can be achieved by allowing arrivals to have two taxi routes: a route that crosses an active departure runway and a perimeter route that avoids the crossing. Results indicate that the multi-route formulation yields reduced arrival taxi times over the single route formulation only when a perimeter taxiway is used. In conditions where the departure aircraft are given an optimal and fixed takeoff sequence, accumulative arrival taxi time savings in the multi-route formulation can be as high as 3.6 hours more than the single route formulation. If the departure sequence is not optimal, the multi-route formulation results in less taxi time savings made over the single route formulation, but the average arrival taxi time is significantly decreased.

  14. Taxis of Pseudomonas putida F1 toward Phenylacetic Acid Is Mediated by the Energy Taxis Receptor Aer2

    Science.gov (United States)

    Luu, Rita A.; Schneider, Benjamin J.; Ho, Christie C.; Nesteryuk, Vasyl; Ngwesse, Stacy E.; Liu, Xianxian; Parales, Juanito V.; Ditty, Jayna L.

    2013-01-01

    The phenylacetic acid (PAA) degradation pathway is a widely distributed funneling pathway for the catabolism of aromatic compounds, including the environmental pollutants styrene and ethylbenzene. However, bacterial chemotaxis to PAA has not been studied. The chemotactic strain Pseudomonas putida F1 has the ability to utilize PAA as a sole carbon and energy source. We identified a putative PAA degradation gene cluster (paa) in P. putida F1 and demonstrated that PAA serves as a chemoattractant. The chemotactic response was induced during growth with PAA and was dependent on PAA metabolism. A functional cheA gene was required for the response, indicating that PAA is sensed through the conserved chemotaxis signal transduction system. A P. putida F1 mutant lacking the energy taxis receptor Aer2 was deficient in PAA taxis, indicating that Aer2 is responsible for mediating the response to PAA. The requirement for metabolism and the role of Aer2 in the response indicate that P. putida F1 uses energy taxis to detect PAA. We also revealed that PAA is an attractant for Escherichia coli; however, a mutant lacking a functional Aer energy receptor had a wild-type response to PAA in swim plate assays, suggesting that PAA is detected through a different mechanism in E. coli. The role of Aer2 as an energy taxis receptor provides the potential to sense a broad range of aromatic growth substrates as chemoattractants. Since chemotaxis has been shown to enhance the biodegradation of toxic pollutants, the ability to sense PAA gradients may have implications for the bioremediation of aromatic hydrocarbons that are degraded via the PAA pathway. PMID:23377939

  15. 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.

  16. Clinical beak and feather disease virus infection in wild juvenile eastern rosellas of New Zealand; biosecurity implications for wildlife care facilities.

    Science.gov (United States)

    Jackson, B; Harvey, C; Galbraith, J; Robertson, M; Warren, K; Holyoake, C; Julian, L; Varsani, A

    2014-09-01

    Four juvenile eastern rosellas (Platycercus eximius) were admitted to two separate wildlife care facilities in the Auckland region by members of the public. They had missing or dystrophic wing and tail feathers that rendered them flightless, suggestive of beak and feather disease virus (BFDV) infection. Two were subject to euthanasia after failing to re-grow their feathers, with samples taken for histopathology and PCR analysis. Blood samples were obtained from the other two birds at the time of examination, however these individuals were lost to follow up. Basophilic inclusion bodies were observed in histological sections of the feather bulb, typical of BFDV infection, from the two euthanised individuals. Blood from all four birds tested positive by PCR for BFDV, and analysis of the recovered full BFDV genomes identified them as belonging to the BFDV-A strain. Beak and feather disease virus infection. This report highlights the clinical impacts of BFDV in juvenile eastern rosellas that may result in their admission to wildlife care facilities, creating a biosecurity risk in institutions that may host other native parrots intended for release. The environmental stability of BFDV and resistance to disinfection requires strict quarantine procedures to prevent contamination and spread within a facility. It is recommended that high-risk species such as wild eastern rosella be excluded from facilities that may also house native parrots.

  17. 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

  18. 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

  19. 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.

  20. 14 CFR 298.52 - Air taxi operations by commuter air carriers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Air taxi operations by commuter air carriers. 298.52 Section 298.52 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52...

  1. 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...

  2. Attractive methods for tracking minibus taxis for public transport regulatory purposes

    CSIR Research Space (South Africa)

    Van Zyl, JE

    2008-07-01

    Full Text Available an extra income for the taxi owner. This generation of revenue for the owner should outweigh the negative aversion the owner has to being monitored by authorities. The attractiveness of applications such as electronic advertising and SMS 'taxi calling...

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Kwazulu-Natal minibus taxi drivers' perceptions on HIV and AIDS ...

    African Journals Online (AJOL)

    In South Africa, the minibus taxi drivers are largely becoming another high-risk category in the HIV and AIDS epidemic. Although previous studies have shown that knowledge of HIV and AIDS is relatively high among the taxi drivers it is still not clear how this sub-population perceive the support rendered to them with regard ...

  5. 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.

  6. 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.

  7. Driving to Better Health: Cancer and Cardiovascular Risk Assessment among Taxi Cab Operators in Chicago

    Science.gov (United States)

    Apantaku-Onayemi, Funmi; Baldyga, William; Amuwo, Shaffdeen; Adefuye, Adedeji; Mason, Terry; Mitchell, Robin; Blumenthal, Daniel S.

    2014-01-01

    While a number of investigations of the health of taxi cab drivers have been conducted in Europe, Asia, and Africa, virtually none have been conducted in the United States. We undertook a survey of taxi cab operators in the Chicago area to understand better their health status and health promotion practices. The survey was completed by a convenience sample of 751 Chicago taxi drivers. Taxi drivers had low rates of insurance coverage, fruit and vegetable consumption, and physical activity compared with the general Chicago population. Participation in cancer screening tests was also lower for this group. A high proportion of taxi drivers are immigrants. They tend to be highly educated and report a readiness to engage in more health-promoting behaviors. Further research is needed to develop a targeted intervention for this population. PMID:22643623

  8. Navigation-related structural change in the hippocampi of taxi drivers.

    Science.gov (United States)

    Maguire, E A; Gadian, D G; Johnsrude, I S; Good, C D; Ashburner, J; Frackowiak, R S; Frith, C D

    2000-04-11

    Structural MRIs of the brains of humans with extensive navigation experience, licensed London taxi drivers, were analyzed and compared with those of control subjects who did not drive taxis. The posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects. A more anterior hippocampal region was larger in control subjects than in taxi drivers. Hippocampal volume correlated with the amount of time spent as a taxi driver (positively in the posterior and negatively in the anterior hippocampus). These data are in accordance with the idea that the posterior hippocampus stores a spatial representation of the environment and can expand regionally to accommodate elaboration of this representation in people with a high dependence on navigational skills. It seems that there is a capacity for local plastic change in the structure of the healthy adult human brain in response to environmental demands.

  9. 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.

  10. Ecological correlates of feather mite prevalence in passerines

    OpenAIRE

    Figuerola, Jordi

    2000-01-01

    The relationship between host ecology and feather mite prevalence was analysed in birds. Feather mites are small arthropods (fam. Pterolichoidea and Analgoidea) commonly found on birds, although the nature of their interactions with the host (commensalism, mutualism or parasitism), still remains unclear. Host body mass and migratory behaviour were unrelated to feather mite prevalence. Contrary to expecta- tion, there was no differences in mite prevalence between colonial and so...

  11. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tsipoura, Nellie [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States); Burger, Joanna, E-mail: burger@biology.rutgers.edu [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States); Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Newhouse, Michael [NJ Meadowlands Commission, One DeKorte Park Plaza, Lyndhurst, NJ 07071 (United States); Jeitner, Christian [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States); Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Gochfeld, Michael [Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Environmental and Occupational Medicine. Robert Wood Johnson Medical School, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Mizrahi, David [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States)

    2011-08-15

    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 {mu}g/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

  13. 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.

  14. From feathers to syngas - technologies and devices.

    Science.gov (United States)

    Dudyński, Marek; Kwiatkowski, Kamil; Bajer, Konrad

    2012-04-01

    The poultry waste produced by industrial slaughterhouses typically contains not only feathers, but also a mixture of animal entrails, nails, blood, beaks and whole carcasses. Economical utilisation of this mixture, varying strongly in composition and moisture content, is, in general, difficult. We demonstrate that this awkward material can be successfully used for gasification in a simple, fixed-bed gasifier. The method of gasification, which we developed, enables control of the gasification process and ensures its stability in the operational regime of a working poultry processing plant. The installation, which has been working in Poland for 2 years, utilises 2 tons of feathers per hour and produces syngas of stable composition and fairly high quality. The syngas is burnt in the combustion chamber adjacent to the gasifier. Heat is recuperated in a boiler producing 3.5 tons per hour of technological steam continuously used for the operation of the slaughterhouse. The whole process complies with the stringent emission standards. In the paper we present the end-use device for feather utilisation and describe the underlying gasification and syngas combustion processes. Key elements of the whole installation are briefly discussed. The environmental impacts of the installation are summarized. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Spatial welfare effects of shared taxi operating policies for first mile airport access

    Directory of Open Access Journals (Sweden)

    Ziyi Ma

    2017-12-01

    Full Text Available With increasing availability of alternative mobility options for first/last mile, it is necessary to better understand how shared taxis are impacting airport access demand and consumer surplus. However, no study has been conducted to evaluate the welfare effects of the range of shared taxi matching and fare allocation policies for airport access. Using several data sources primarily from Port Authority of NY and NJ and The Taxi and Limousine Commission, a mode choice model is estimated for access to John F. Kennedy International Airport in New York City. The baseline model and data show that passengers have a value of time of $101 per hour, consistent with Harvey’s study from 1986. Airport taxi travelers are also elastic to cost in a similar manner to public transit. The model is used to evaluate two policies: a first (we call this wait-share policy where taxis can offer shared rides for two passengers from the same zip code, incorporating an endogenous expected wait time variable; and a second (we call this space-share policy where taxis match randomly arriving passengers from any zip codes in the city. These two policies reflect extreme ends of a spectrum of policies between waiting and detouring. Findings suggest that having a shared taxi option benefit passengers in NYC going to JFK airport by at least 10% increase in consumer surplus. However, the increase in taxi ridership comes at a cost to transit ridership. Furthermore, the population in NYC that benefits most is highly dependent on the type of shared taxi policy. A wait-share policy benefits passengers from the dense parts of Manhattan most, while a space-share policy distributes the benefits more to other boroughs. These insights can help policymakers set regulations in providing first/last mile ride-sharing taxi options in different cities around the world.

  16. 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.

  17. 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

    . 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....

  18. 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...... individuals specialised in pecking at other specific birds, at specific areas of the body or at birds engaged in specific activities. 5. Growers (3 groups, experiment 2) that had just feather pecked engaged in more feather pecking during a subsequent 2-min focal observation than control birds that had...

  19. [Comparative life cycle environmental assessment between electric taxi and gasoline taxi in Beijing].

    Science.gov (United States)

    Shi, Xiao-Qing; Sun, Zhao-Xin; Li, Xiao-Nuo; Li, Jin-Xiang; Yang, Jian-Xin

    2015-03-01

    Tailpipe emission of internal combustion engine vehicle (ICEV) is one of the main sources leading to atmospheric environmental problems such as haze. Substituting electric vehicles for conventional gasoline vehicles is an important solution for reducing urban air pollution. In 2011, as a pilot city of electric vehicle, Beijing launched a promotion plan of electric vehicle. In order to compare the environmental impacts between Midi electric vehicle (Midi EV) and Hyundai gasoline taxi (ICEV), this study created an inventory with local data and well-reasoned assumptions, and contributed a life cycle assessment (LCA) model with GaBi4.4 software and comparative life cycle environmental assessment by Life cycle impact analysis models of CML2001(Problem oriented) and EI99 (Damage oriented), which included the environmental impacts of full life cycle, manufacture phase, use phase and end of life. The sensitivity analysis of lifetime mileage and power structure was also provided. The results indicated that the full life cycle environmental impact of Midi EV was smaller than Hyundai ICEV, which was mainly due to the lower fossil fuel consumption. On the contrary, Midi EV exhibited the potential of increasing the environmental impacts of ecosystem quality influence and Human health influence. By CML2001 model, the results indicated that Midi EV might decrease the impact of Abiotic Depletion Potential, Global Warming Potential, Ozone Layer Depletion Potential and so on. However, in the production phase, the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Ozone Layer Depletion Potential, Marine Aquatic Ecotoxicity Potential, Terrestric Ecotoxicity Potential, Human Toxicity Potential of Midi EV were increased relative to Hyundai ICEV because of emissions impacts from its power system especially the battery production. Besides, in the use phase, electricity production was

  20. 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.

  1. Motor vehicle accidents, fatigue and optimism bias in taxi drivers.

    Science.gov (United States)

    Dalziel, J R; Job, R F

    1997-07-01

    Fatigue-related variables and their relationship with accident involvement were examined in a group of 42 Sydney metropolitan taxi drivers across a 2-year period. Advantages associated with the study of this group of road users include their important role in public transport, long hours spent on the road, job-related controls of exposure through shift patterns and the ability to verify accidents with company insurance records. Number and length of breaks, employment type, falling asleep at the wheel and a variety of other job-related and attitudinal variables were surveyed. Results provide basic data on fatigue-related aspects of the job of taxi driving. Driver time-on-the-road is often considerable: 67% of those surveyed drove at least 50 hours per week, yet time off in long shifts (up to 12 hours) was often short (as low as 3 minutes, with an average of 37 minutes). Self report of accidents proved reliable against insurance company records. A significant negative correlation between total average break time and accident rate was observed. Optimism bias was present for a variety of driving-related questions, including the ability to drive safely while fatigued.

  2. 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.

  3. [A study on work and daily life factors affecting the health of taxi drivers].

    Science.gov (United States)

    Ueda, T; Hashimoto, M; Kosaka, M; Higashida, T; Hara, I; Kurimoto, T

    1992-01-01

    In order to elucidate factors affecting taxi drivers health, a questionnaire survey was performed on 5523 taxi drivers and health examinations were conducted on 311 taxi drivers from among them. Analysis by a method of multivariate analysis called Quantification II was performed with dependent variables being blood pressure, the number of subjective symptoms and fatigue on rising, and independent variables being work and daily life conditions. The major results of this survey were as follows: 1) A tendency for hypertension risk to increase with degree of obesity, and both employment as a taxi driver for 1-4 years and over twenty years of taxi driving were positively associated with increase in risk for hypertension. 2) Common factors to all types of work shifts which were related to an increase in the number of subjective symptoms were irregularity of meals, insufficient rest on off days, large number of years engagement at taxi driving, frequent frightening experiences while driving and comparatively short driving distance in one shift. 3) Common factors to all types of work shifts that were connected with fatigue at the time of rising were insufficient rest on off days and long years engagement in taxi driving.

  4. 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

  5. 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.

  6. Experimental maturation of feathers: implications for reconstructions of fossil feather colour.

    Science.gov (United States)

    McNamara, Maria E; Briggs, Derek E G; Orr, Patrick J; Field, Daniel J; Wang, Zhengrong

    2013-06-23

    Fossil feathers often preserve evidence of melanosomes-micrometre-scale melanin-bearing organelles that have been used to infer original colours and patterns of the plumage of dinosaurs. Such reconstructions acknowledge that evidence from other colour-producing mechanisms is presently elusive and assume that melanosome geometry is not altered during fossilization. Here, we provide the first test of this assumption, using high pressure-high temperature autoclave experiments on modern feathers to simulate the effects of burial on feather colour. Our experiments show that melanosomes are retained despite loss of visual evidence of colour and complete degradation of other colour-producing structures (e.g. quasi-ordered arrays in barbs and the keratin cortex in barbules). Significantly, however, melanosome geometry and spatial distribution are altered by the effects of pressure and temperature. These results demonstrate that reconstructions of original plumage coloration in fossils where preserved features of melanosomes are affected by diagenesis should be treated with caution. Reconstructions of fossil feather colour require assessment of the extent of preservation of various colour-producing mechanisms, and, critically, the extent of alteration of melanosome geometry.

  7. 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.

  8. Isolation and characterization of feather degrading bacteria from ...

    African Journals Online (AJOL)

    puchooa

    2012-09-04

    Sep 4, 2012 ... wastes from the poultry industry and the nutritional upgrading of feather ... primary screening, skimmed milk agar was used comprising of 5.0 g/l peptone, 3.0 g/L ... production. Different feather concentrations were tested for their effects on the keratinase secretion from the bacteria. 250 ml conical flasks with ...

  9. Bioprocess enhancement of feather degradation using alkaliphilic microbial mixture.

    Science.gov (United States)

    Osman, Y; Elsayed, A; Mowafy, A M; Abdelrazak, A; Fawzy, M

    2017-06-01

    1. The main aim of this work is to develop a robust method to generate a microbial mixture which can successfully degrade poultry feathers to overcome environmental problems. 2. Four different alkaliphilic microbes were isolated and shown to degrade poultry feathers. 3. Two of the isolates were phylogenetically identified as Lysinibacillus and the others were identified as Nocardiopsis and Micrococcus. 4. The best microbial co-culture for white and black feather degradation was optimised for pH, temperature and relative population of the isolates to achieve almost 96% of degradation compared with a maximum of 31% when applying each isolate individually. 5. The maximum activity of keratinase was estimated to be 1.5 U/ml after 3 d for white feathers and 0.6 U/ml after 4 d for black feathers in a basal medium containing feather as the main carbon source. Additionally, non-denaturing polyacrylamide gel electrophoresis showed 4 and 3 protease activity bands for white and black feather, respectively. 6. This study provides a robust method to develop potential new mixtures of microorganisms that are able to degrade both white and black feathers by applying a Central Composite Design.

  10. 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 ...

  11. 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

  12. Feather pecking and monoamines - a behavioral and neurobiological approach

    NARCIS (Netherlands)

    Kops, M.S.

    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

  13. A safety monitoring system for taxi based on CMOS imager

    Science.gov (United States)

    Liu, Zhi

    2005-01-01

    CMOS image sensors now become increasingly competitive with respect to their CCD counterparts, while adding advantages such as no blooming, simpler driving requirements and the potential of on-chip integration of sensor, analogue circuitry, and digital processing functions. A safety monitoring system for taxi based on cmos imager that can record field situation when unusual circumstance happened is described in this paper. The monitoring system is based on a CMOS imager (OV7120), which can output digital image data through parallel pixel data port. The system consists of a CMOS image sensor, a large capacity NAND FLASH ROM, a USB interface chip and a micro controller (AT90S8515). The structure of whole system and the test data is discussed and analyzed in detail.

  14. Suppression of radiated emission in fiscal taxi meter

    Science.gov (United States)

    He, Hong; Yang, Pei-pei; Su, Xing; Zhang, Da-jian; Wang, Ke-xi; Hou, Ming-feng

    2011-12-01

    This paper is based upon National Standards for EMC. For the problem that the intensity of electromagnetic radiation in the meter with the THG at 36MHz is seriously more than National Standards, by studying the theory of radiation emission and analyzing the formation mechanism of electromagnetic radiation interference, it proposes three restrain measures: 1.the improvement of the Crystal oscillator's grounding measure; 2.adding a RC filter circuit to the Crystal oscillator circuit; 3.the improvement of the tax's communication cable, solving the problem that radiation harassment the taxi meter seriously exceeds. The experimental result demonstrates that the radiation intensity of tax meter improved with the general measures meet the requirements of the national standard, making more than 32000 taxes in Tianjin install this green meter, protecting the safety of staff and normal operation of the surrounding equipment.

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

    Directory of Open Access Journals (Sweden)

    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

  16. Aerodynamic characteristics of a feathered dinosaur measured using physical models. Effects of form on static stability and control effectiveness.

    Directory of Open Access Journals (Sweden)

    Dennis Evangelista

    Full Text Available We report the effects of posture and morphology on the static aerodynamic stability and control effectiveness of physical models based on the feathered dinosaur, [Formula: see text]Microraptor gui, from the Cretaceous of China. Postures had similar lift and drag coefficients and were broadly similar when simplified metrics of gliding were considered, but they exhibited different stability characteristics depending on the position of the legs and the presence of feathers on the legs and the tail. Both stability and the function of appendages in generating maneuvering forces and torques changed as the glide angle or angle of attack were changed. These are significant because they represent an aerial environment that may have shifted during the evolution of directed aerial descent and other aerial behaviors. Certain movements were particularly effective (symmetric movements of the wings and tail in pitch, asymmetric wing movements, some tail movements. Other appendages altered their function from creating yaws at high angle of attack to rolls at low angle of attack, or reversed their function entirely. While [Formula: see text]M. gui lived after [Formula: see text]Archaeopteryx and likely represents a side experiment with feathered morphology, the general patterns of stability and control effectiveness suggested from the manipulations of forelimb, hindlimb and tail morphology here may help understand the evolution of flight control aerodynamics in vertebrates. Though these results rest on a single specimen, as further fossils with different morphologies are tested, the findings here could be applied in a phylogenetic context to reveal biomechanical constraints on extinct flyers arising from the need to maneuver.

  17. Can short-term frustration facilitate feather pecking in laying hens?

    NARCIS (Netherlands)

    Rodenburg, T.B.; Koene, P.; Bokkers, E.A.M.; Bos, M.E.H.; Uitdehaag, K.A.; Spruijt, B.M.

    2005-01-01

    Feather pecking is a major problem in laying hens. Frustration, i.e. the omission of expected reward, may play a role in the development of feather pecking. In two experiments, we studied if feather pecking could be facilitated by short-term frustration in birds with a high feather pecking phenotype

  18. An improved extraction method to increase DNA yield from molted feathers

    Science.gov (United States)

    Shelley Bayard De Volo; Richard T. Reynolds; Marlis R. Douglas; Michael F. Antolin

    2008-01-01

    To assess the value of molted feathers as a noninvasive source of DNA for genetic studies of Northern Goshawks (Accipiter gentilis), we isolated and quantified DNA from molted feathers and compared yields across five feather types. We also compared PCR success across the same five feather types using five microsatellite genetic markers of varying...

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

    National Research Council Canada - National Science Library

    Granetto, Paul

    1999-01-01

    .... The Defense Supply Center, Columbus, Office of Installation Services operates the motor pool with a staff of 12 full-time civilian employees, including 9 drivers who perform the taxi and shuttle bus service...

  20. Increasing influenza vaccination in New York City taxi drivers: A community driven approach.

    Science.gov (United States)

    Gany, Francesca; Rau-Murthy, Rohini; Mujawar, Imran

    2015-05-21

    The Healthy People 2020 influenza immunization goal is 80% for non-institutionalized adults 18-64. However, vaccination rates remain stubbornly low. Culturally tailored approaches to communities with poor vaccine uptake are necessary. Taxi drivers are at risk for influenza and its complications, could serve as vectors for influenza infection, and could be an effective vaccination target to enhance herd immunity of the urban population. To the best of our knowledge, this is the first study related to influenza vaccination among taxi drivers. The NYC Taxi Network surveyed a convenience sample of 53 taxi drivers to understand vaccination barriers. Only 17% had been vaccinated. Results informed a pilot tailored workplace intervention, which resulted in vaccinations for 44% of unvaccinated drivers. The study revealed that older drivers were more likely to be vaccinated than younger drivers, while the most common barrier to immunization was that drivers thought vaccination was 'not necessary'. Copyright © 2015. Published by Elsevier Ltd.

  1. 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...

  2. 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

  3. Prevention of taxi accidents in Xi'an, China: what matters most?

    Science.gov (United States)

    Wang, Yonggang; Li, Ming; Du, Jianhua; Mao, Chengyuan

    2015-03-01

    Since the city of Xi'an has been extremely concerned with the serious problem of taxi involved crashes, injuries and fatalities, the primary purpose of this study is to identify the risk factors associated with the magnitude and nature of the problem and provide possible measures for enhancing the overall safety performance of taxi industry. Using 726 crash samples from the original of 7,183 observations in Xi'an over the period from 2006 to 2012, comparative statistics and systematic analysis were employed to describe the distribution of taxi crashes by driver characteristics, roadway contributors and environmental factors and then determine the significant factors contributing to crash injuries and fatalities. The trend and pattern of taxi involved crashes vary significantly. Middle aged (77.27%) male (91.60%) drivers with limited education (68.59%) and less driving (31.27%) and job (82.50%) experience were much more likely to be involved in such a crash. Additionally, it is found that a large majority of taxi crashes occurred with the most frequent type of rear end collisions (30.72%), on six-lane segments without median (16.94%) or four legged intersections (15.29%), under adverse weather conditions (31.82%), at weekends (34.99%), and during winter days (34.72%), but fatal and serious crashes were more likely to happen at night (30.72%) or under wet road surface conditions (16.94%), due to driver's overspeeding, unbelted, disregarding signs or signals, or other types of risk driving behaviour. The risk of taxi related crashes varies by drivers, roadways and environment. To reduce the risk of potential crashes for taxi drivers, we recommend the targeted legislation and enforcement, stronger night and trip restrictions, awareness of risk behaviour, and periodical training requirement. Such proposals and measures are expected to help mitigate taxi crashes and promote road safety in China.

  4. Evaluation of strategies for reducing taxi-out emissions at airports

    OpenAIRE

    Deonandan, Indira; Balakrishnan, Hamsa

    2010-01-01

    Aircraft taxiing on the surface contribute significantly to the fuel burn and emissions at airports. This paper is aimed at estimating the baseline fuel burn and emissions from taxi-out processes at airports, evaluating the potential benefits of strategies proposed to reduce them, and assessing the critical implementation barriers that need to be overcome prior to the adoption of these approaches at airports. This study evaluates the effects of two different strategies, namely, single engine ...

  5. 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

  6. 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.

  7. 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.

  8. Charging Guidance of Electric Taxis Based on Adaptive Particle Swarm Optimization

    Science.gov (United States)

    Niu, Liyong; Zhang, Di

    2015-01-01

    Electric taxis are playing an important role in the application of electric vehicles. The actual operational data of electric taxis in Shenzhen, China, is analyzed, and, in allusion to the unbalanced time availability of the charging station equipment, the electric taxis charging guidance system is proposed basing on the charging station information and vehicle information. An electric taxis charging guidance model is established and guides the charging based on the positions of taxis and charging stations with adaptive mutation particle swarm optimization. The simulation is based on the actual data of Shenzhen charging stations, and the results show that electric taxis can be evenly distributed to the appropriate charging stations according to the charging pile numbers in charging stations after the charging guidance. The even distribution among the charging stations in the area will be achieved and the utilization of charging equipment will be improved, so the proposed charging guidance method is verified to be feasible. The improved utilization of charging equipment can save public charging infrastructure resources greatly. PMID:26236770

  9. SOUND ABSORPTION PROPERTIES OF COMPOSITES MADE OF DISCARDED DUCK FEATHERS

    OpenAIRE

    BI, Jihong; YU, Xiang; WANG, Xiao; WEI, Chunyan; CUI, Yongzhu; LV, Lihua

    2016-01-01

    A novel composite with good sound absorption properties was prepared by discarded duck feathers and Ethylene vinyl acetate copolymer (EVA) non-woven fabrics by using lay-up and hot-pressing method. The effects of discarded duck feather concentration, composite density, composite thickness and air cavity depth on sound absorption performance were studied. When the composites with proportion (w/w) of the discarded duck feathers to EVA non-woven fabrics of 300/100, density of 1400g/m2, thickness...

  10. 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

  11. Mechanochromic response of the barbules in peacock tail feather

    Science.gov (United States)

    Jiang, Yonggang; Wang, Rui; Feng, Lin; Zhang, Deyuan

    2018-01-01

    Peacock tail feathers exhibit diverse striking brilliancy, as the cortex in different colored barbules of the feathers contains a 2-D photonic-crystal structure. The mechanochromic response of the 2-D photonic structure in peacock feather barbules is measured for the first time, by combining an in-situ stretching device and a reflectivity measurement system. The reflectance spectra of the barbule specimen blueshifts own to stretching along its longitudinal direction. A high strain sensitivity of 5.3 nm/% is obtained for green barbules. It could be of great help in bionic design of strain sensors using 2D photonic crystal structures.

  12. 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.

  13. Aerodynamics of wing-assisted incline running in birds.

    Science.gov (United States)

    Tobalske, Bret W; Dial, Kenneth P

    2007-05-01

    Wing-assisted incline running (WAIR) is a form of locomotion in which a bird flaps its wings to aid its hindlimbs in climbing a slope. WAIR is used for escape in ground birds, and the ontogeny of this behavior in precocial birds has been suggested to represent a model analogous to transitional adaptive states during the evolution of powered avian flight. To begin to reveal the aerodynamics of flap-running, we used digital particle image velocimetry (DPIV) and measured air velocity, vorticity, circulation and added mass in the wake of chukar partridge Alectoris chukar as they engaged in WAIR (incline 65-85 degrees; N=7 birds) and ascending flight (85 degrees, N=2). To estimate lift and impulse, we coupled our DPIV data with three-dimensional wing kinematics from a companion study. The ontogeny of lift production was evaluated using three age classes: baby birds incapable of flight [6-8 days post hatching (d.p.h.)] and volant juveniles (25-28 days) and adults (45+ days). All three age classes of birds, including baby birds with partially emerged, symmetrical wing feathers, generated circulation with their wings and exhibited a wake structure that consisted of discrete vortex rings shed once per downstroke. Impulse of the vortex rings during WAIR was directed 45+/-5 degrees relative to horizontal and 21+/-4 degrees relative to the substrate. Absolute values of circulation in vortex cores and induced velocity increased with increasing age. Normalized circulation was similar among all ages in WAIR but 67% greater in adults during flight compared with flap-running. Estimated lift during WAIR was 6.6% of body weight in babies and between 63 and 86% of body weight in juveniles and adults. During flight, average lift was 110% of body weight. Our results reveal for the first time that lift from the wings, rather than wing inertia or profile drag, is primarily responsible for accelerating the body toward the substrate during WAIR, and that partially developed wings, not yet

  14. 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

  15. 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

  16. Effects of feather pecking phenotype (severe feather peckers, victims and non-peckers) on serotonergic and dopaminergic activity in four brain areas of laying hens (Gallus gallus domesticus)

    NARCIS (Netherlands)

    Kops, M.S.; Haas, de E.N.; Rodenburg, T.B.; Ellen, E.D.; Korte-Bouws, G.A.H.; Olivier, B.; Güntürkün, O.; Bolhuis, J.E.; Korte, S.M.

    2013-01-01

    Severe feather pecking (SFP) in laying hens is a detrimental behavior causing loss of feathers, skin damage and cannibalism. Previously, we have associated changes in frontal brain serotonin (5-HT) turnover and dopamine (DA) turnover with alterations in feather pecking behavior in young pullets

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

    Directory of Open Access Journals (Sweden)

    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

  18. 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

  19. Low back pain among taxi drivers: a cross-sectional study.

    Science.gov (United States)

    Wang, M; Yu, J; Liu, N; Liu, Z; Wei, X; Yan, F; Yu, S

    2017-06-01

    Low back pain (LBP) is a common occupational problem for drivers all over the world. However, few epidemiological studies have investigated LBP among taxi drivers. To investigate the prevalence of LBP and associated work-related factors among Chinese taxi drivers. A cross-sectional survey was administered to all participants. Using cluster sampling, questionnaires were collected from taxi drivers of three major taxi companies in Jinan, China. Univariate and multivariate logistic regressions were used to estimate the odd ratios (ORs) and 95% confidence intervals (CIs) among participants. A total of 800 taxi drivers were invited to take part, with a participation rate of 90%. The 1-year period prevalence of LBP was 54%. Multivariate logistic regression analysis revealed that longer daily driving duration (OR 3.3, 95% CI 1.9-5.9), night shifts (OR 1.9, 95% CI 1.2-3.1) and increasing work years as a taxi driver (OR 1.7, 95% CI 1.2-2.5) were associated with increased risk of reporting LBP; while increased rest days per month (OR 0.8, 95% CI 0.7-0.9), longer sleep duration (OR 0.7, 95% CI 0.5-0.9) and more physical activity (OR 0.5, 95% CI 0.3-0.8) were significantly associated with decreased risk of reporting LBP. The prevalence of LBP among professional taxi drivers in China was associated with a number of occupational features. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  20. 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

  1. STUDY OF DIFFERENT TREATMENT METHODS ON CHICKEN FEATHER BIOMASS

    Directory of Open Access Journals (Sweden)

    Swati Sharma

    2017-12-01

    Full Text Available The chicken feathers (CFs  consist of up to 10 % of total chicken dry mass and they have many potential industrial applications. CFs contains protein fibers named as keratin, which is an insoluble protein. Primary sanitization phases are complex because of the presence of lots of blood born microbes, pathogens and parasites in raw biomass. The extraction process of keratins from the unprocessed feathers is also a challenging task. Prior to the extraction cleaning/sanitization of feathers is a very necessary step. Thus, the present work was conducted to optimize  an efficient surfactant  for the cleaning process of the  CFs by using ionic and non-ionic surfactants. The experiment was conducted by the washing of feathers with double distilled water (ddH2O, detergents, ether and lastly with boiling water. The washed feathers treated with surfactants and the effect of each surfactant was analyzed by a microbiological test which tells about the extent of  the presence of different bacteria on the treated feathers. SEM, EDX, FTIR were used to study the morphology and composition of  untreated and treated CFs. SEM showed there was no detectable fiber damage after treatment. Cetrimonium bromide (CTAB (t3 was one of the best surfactant for the treatment of CFs among all the surfactant used. The present study described the best treatment method  for the CFs.

  2. 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.

  3. Collective human mobility pattern from taxi trips in urban area

    KAUST Repository

    Peng, Chengbin

    2012-04-18

    We analyze the passengers\\' traffic pattern for 1.58 million taxi trips of Shanghai, China. By employing the non-negative matrix factorization and optimization methods, we find that, people travel on workdays mainly for three purposes: commuting between home and workplace, traveling from workplace to workplace, and others such as leisure activities. Therefore, traffic flow in one area or between any pair of locations can be approximated by a linear combination of three basis flows, corresponding to the three purposes respectively. We name the coefficients in the linear combination as traffic powers, each of which indicates the strength of each basis flow. The traffic powers on different days are typically different even for the same location, due to the uncertainty of the human motion. Therefore, we provide a probability distribution function for the relative deviation of the traffic power. This distribution function is in terms of a series of functions for normalized binomial distributions. It can be well explained by statistical theories and is verified by empirical data. These findings are applicable in predicting the road traffic, tracing the traffic pattern and diagnosing the traffic related abnormal events. These results can also be used to infer land uses of urban area quite parsimoniously. 2012 Peng et al.

  4. Study the epidemiological profile of taxi drivers in the background of occupational environment, stress and personality characteristics

    Science.gov (United States)

    Bawa, Mukesh Suresh; Srivastav, Manissha

    2013-01-01

    Background: Work hazards have been a major cause of concern in driving industry especially in taxi drivers. This study integrates the various factors that influence physical and emotional well-being of taxi drivers into the theoretical model that shows that the work environment, stress and personality characteristics directly influence taxi drivers’ health. Objective: The aim of the following study is to study the relative and combined influence of work environment, personality characteristics and stress on the health of taxi drivers. Meterials and Methods: The present study is cross-sectional (descriptive) study taxi drivers in Mumbai. They are selected using multistage random sampling method. Calculated sample size is 508. Data produced after the survey is analyzed using IBM SPSS 16.0 software. Results: Nearly 65% of taxi drivers belonged to middle-age group of 21-40 years of age. Majority (59%) of taxi drivers belonged to the lower upper socio-economic class. 70% of taxi drivers worked for more than 8 h daily. 63% gave the history of one or more addictions. 52% taxi drivers had type B1 personality, only 6% had stress prone and aggressive type A1 personality. Traffic congestion (67.1%) was reported as the leading stressor followed by narrow bottle neck roads (43%), too many speed breakers (41%), rude gestures and behavior by other drivers (42%) and bad weather (36%). Nearly 86% taxi drivers had one or more symptoms of morbidities. Gastrointestinal symptoms predominated followed by musculoskeletal symptoms and depression. Conclusion: Socio-demographic attributes, work environment, stress and personality significantly influence physical and psychological morbidities in taxi drivers. PMID:24872669

  5. [Risk factors for low back pain among taxi drivers in Japan].

    Science.gov (United States)

    Funakoshi, Mitsuhiko; Tamura, Akihiko; Taoda, Kazushi; Tsujimura, Hiroji; Nishiyama, Katsuo

    2003-11-01

    We conducted a questionnaire study on low back pain (LBP) and working conditions among male taxi drivers employed in the company in Fukuoka city in order to investigate the occurrence of LBP and occupational factors related to LBP among taxi drivers. The study was undertaken through two questionnaires, the first conducted in 1999 (n = 280, first cross-sectional study), the second conducted in 2001 (n = 284, second cross-sectional study). The questionnaire results were used to conduct two analyses: 1) the one-year prevalence of LBP and the relationship between LBP and occupational factors in the second cross-sectional study, and 2) the incidence of LBP and the relationship between LBP and occupational factors from the first to the second cross-sectional study in the longitudinal study. The incidence cases were defined as subjects who met the following conditions: those who had never experienced LBP at the time of the first study but had experienced LBP during the previous year at the time of the 2nd study. The one-year prevalence (45.8%) of LBP among taxi drivers was comparable to rates reported for other occupational drivers in which LBP occurs frequently. This result indicates that LBP is an important health problem for taxi drivers, and an urgent occupational safety and health management issue. The two-year incidence of LBP among the taxi drivers was estimated at 25.9%. LBP was significantly related with the suitability of the driver's seat pan, total mileage on the taxi (total mileage), the level of uncomfortable vibrations on the road, job stress and time employed as a taxi driver. Importantly, the prevalence of LBP increased with increasing total mileage, a finding which had not previously been reported. The findings of this study also suggest that ergonomic problems with the driver's seat pan, whole-body vibration (WBV) and job stress may contribute to LBP among taxi drivers. Further study is needed to confirm how total mileage contributes to LBP. Furthermore

  6. 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.

  7. 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

  8. 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.

  9. Discrimination and Health Among Taxi Drivers in New York and Toronto.

    Science.gov (United States)

    Mirpuri, Sheena; Gill, Pavan; Ocampo, Alex; Roberts, Nicole; Narang, Bharat; Hwang, Stephen W; Gany, Francesca

    2018-01-24

    Immigrant taxi drivers in metropolitan cities are exposed to experiences of discrimination and occupation-based health risks. Given the structural differences in health care systems in the United States and Canada, we investigated the differences in reports of discrimination, health conditions and concern about health conditions between taxi drivers in New York City and Toronto, Ontario. Participants were recruited for a taxi driver Needs Assessment Survey as part of a Taxi Network needs assessment project using a street side convenience sampling technique in New York City and Toronto. The matched sample contained 33 drivers from Toronto and 33 drivers from NYC. All Toronto drivers in our sample reported having health insurance while over a quarter of NYC drivers did not have health insurance. Toronto drivers reported greater everyday and workplace discrimination. Drivers in both cities experienced higher rates than average, and reported concern about, major health conditions. We also found preliminary evidence suggesting a relationship between experiencing discrimination and reporting chronic pain. Our findings suggest the need for future research to more closely examine the associations between discrimination and health among the taxi driver population.

  10. 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

  11. Detecting Anomalous Trajectories and Behavior Patterns Using Hierarchical Clustering from Taxi GPS Data

    Directory of Open Access Journals (Sweden)

    Yulong Wang

    2018-01-01

    Full Text Available Anomalous taxi trajectories are those chosen by a small number of drivers that are different from the regular choices of other drivers. These anomalous driving trajectories provide us an opportunity to extract driver or passenger behaviors and monitor adverse urban traffic events. Because various trajectory clustering methods have previously proven to be an effective means to analyze similarities and anomalies within taxi GPS trajectory data, we focus on the problem of detecting anomalous taxi trajectories, and we develop our trajectory clustering method based on the edit distance and hierarchical clustering. To achieve this objective, first, we obtain all the taxi trajectories crossing the same source–destination pairs from taxi trajectories and take these trajectories as clustering objects. Second, an edit distance algorithm is modified to measure the similarity of the trajectories. Then, we distinguish regular trajectories and anomalous trajectories by applying adaptive hierarchical clustering based on an optimal number of clusters. Moreover, we further analyze these anomalous trajectories and discover four anomalous behavior patterns to speculate on the cause of an anomaly based on statistical indicators of time and length. The experimental results show that the proposed method can effectively detect anomalous trajectories and can be used to infer clearly fraudulent driving routes and the occurrence of adverse traffic events.

  12. 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...

  13. Understanding the Impact of Human Mobility Patterns on Taxi Drivers’ Profitability Using Clustering Techniques: A Case Study in Wuhan, China

    Directory of Open Access Journals (Sweden)

    Hasan A. H. Naji

    2017-06-01

    Full Text Available Taxi trajectories reflect human mobility over the urban roads’ network. Although taxi drivers cruise the same city streets, there is an observed variation in their daily profit. To reveal the reasons behind this issue, this study introduces a novel approach for investigating and understanding the impact of human mobility patterns (taxi drivers’ behavior on daily drivers’ profit. Firstly, a K-means clustering method is adopted to group taxi drivers into three profitability groups according to their driving duration, driving distance and income. Secondly, the cruising trips and stopping spots for each profitability group are extracted. Thirdly, a comparison among the profitability groups in terms of spatial and temporal patterns on cruising trips and stopping spots is carried out. The comparison applied various methods including the mash map matching method and DBSCAN clustering method. Finally, an overall analysis of the results is discussed in detail. The results show that there is a significant relationship between human mobility patterns and taxi drivers’ profitability. High profitability drivers based on their experience earn more compared to other driver groups, as they know which places are more active to cruise and to stop and at what times. This study provides suggestions and insights for taxi companies and taxi drivers in order to increase their daily income and to enhance the efficiency of the taxi industry.

  14. WINGS Data Release

    DEFF Research Database (Denmark)

    Moretti, A.; Poggianti, B. M.; Fasano, G.

    2014-01-01

    Context. To effectively investigate galaxy formation and evolution, it is of paramount importance to exploit homogeneous data for large samples of galaxies in different environments. Aims. The WIde-field Nearby Galaxy-cluster Survey (WINGS) project aim is to evaluate physical properties of galaxies...... in a complete sample of low redshift clusters to be used as reference sample for evolutionary studies. The WINGS survey is still ongoing and the original dataset will be enlarged with new observations. This paper presents the entire collection of WINGS measurements obtained so far. Methods. We decided to make......, and on the cluster redshift, reaching on average 90% at V ≲ 21.7. Near-infrared photometric catalogs for 26 (in K) and 19 (in J) clusters are part of the database and the number of sources is 962 344 in K and 628 813 in J. Here again the completeness depends on the data quality, but it is on average higher than 90...

  15. [A questionnaire study on health of taxi drivers--relations to work conditions and daily life].

    Science.gov (United States)

    Ueda, T; Hashimoto, M; Yasui, I; Sunaga, M; Higashida, T; Hara, I

    1989-05-01

    A questionnaire survey was conducted on 5,523 taxi drivers in Osaka Prefecture to investigate their working conditions and daily life as well as characteristics of their health condition and various effects on health, especially on their cardiovascular system. The major results of this survey were as follows: 1) The rate of subjective symptoms, morbidity rate and rate of poor physical condition over the past year in the taxi drivers were higher than those of the control group. Among the subjective symptoms, the rate of gastrointestinal disorders, fatigue, musculoskeletal system disorders, sensory system disorders, hemorrhoids, etc. was especially high. 2) Work shift, density of work, years of experience in taxi-driving, frequency of fright while driving, pattern of taking meals, way of recuperation on rest days or holidays, obesity, smoking, and intake of coffee and alcohol were found to be factors affecting the health of taxi drivers. 3) Nearly half of the respondents said that they would like to quit or change their job with as much as 62% giving "condition of health" as reason. On the other hand, the rate of heart-related symptoms such as palpitation, and breathlessness did not differ from that of the control group. The possible reason for this deduced from the foregoing results, is that there were some who had changed or quit the job at an early stage for health reasons such as heart trouble and severe physical and mental burden resulting from taxi driving. 4) Many taxi driver are obese and the rate of those with heart-related symptoms was considerably high among those classified as obese. In addition, the results showed that those with longer driving experience tended to be obese.

  16. 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.

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

    OpenAIRE

    Kotaro Sakurai; Junko Yamamoto; Tsugiko Kurita; Youji Takeda; Ichiro Kusumi

    2014-01-01

    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 ...

  18. k0-INAA for determining chemical elements in bird feathers

    Science.gov (United States)

    França, Elvis J.; Fernandes, Elisabete A. N.; Fonseca, Felipe Y.; Antunes, Alexsander Z.; Bardini Junior, Claudiney; Bacchi, Márcio A.; Rodrigues, Vanessa S.; Cavalca, Isabel P. O.

    2010-10-01

    The k0-method instrumental neutron activation analysis ( k0-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, São 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 k0-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 -1), Co (max=0.47 mg kg -1), Cr (max=68 mg kg -1), Hg (max=2.79 mg kg -1), Sb (max=0.20 mg kg -1), Se (max=1.3 mg kg -1) and Zn (max=192 mg kg -1) in bird feathers, probably associated with the degree of pollution of the areas evaluated. In order to corroborate the use of k0-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.

  19. Seeking carotenoid pigments in amber-preserved fossil feathers

    Science.gov (United States)

    Thomas, Daniel B.; Nascimbene, Paul C.; Dove, Carla J.; Grimaldi, David A.; James, Helen F.

    2014-06-01

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

  20. Seeking carotenoid pigments in amber-preserved fossil feathers.

    Science.gov (United States)

    Thomas, Daniel B; Nascimbene, Paul C; Dove, Carla J; Grimaldi, David A; James, Helen F

    2014-06-09

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

  1. Nutritional stress affects corticosterone deposition in feathers of Caspian tern chicks

    Science.gov (United States)

    Patterson, Allison G. L.; Kitaysky, Alexander S.; Lyons, Donald E.; Roby, Daniel D.

    2015-01-01

    Stressful environmental conditions affect the adrenocortical function of developing animals, which can have consequences for their fitness. Discovery of the avian stress hormone corticosterone (CORT) in feathers has the potential to broaden the application of endocrine research in ecological and evolutionary studies of wild birds by providing a long-term measure of CORT secretion. Mechanisms of CORT deposition in feathers are not well known and few studies have related feather CORT to circulating plasma CORT during feather growth. Our objective was to experimentally test the validity of using feather CORT as a measure of CORT secretion in developing birds experiencing nutritional stress. Caspian tern Hydroprogne caspia chicks were fed ad libitum or restricted (35% less than ad libitum) diets for four weeks. We measured CORT in feathers from these chicks to examine the relationship between feather CORT concentrations and nutritional limitation, circulating plasma CORT, and feather development. We found that feather CORT was higher in controls fed ad libitum than in restricted individuals, despite higher levels of plasma CORT in restricted chicks compared to controls. Feather mass and growth rates were strongly and positively related to feather CORT concentrations in both treatments. This is the first experimental study to show that feather CORT concentrations can be lower in response to nutritional stress, even when plasma CORT concentrations are elevated. Our results indicate that CORT deposition in feathers may be confounded when feather mass and growth rates are compromised by nutritional stress. We conclude that feather CORT can be used for assessing nutritional stress in growing birds, but the direction of response depends on how strongly stress affects feather development.

  2. 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.

  3. 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...

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

    NARCIS (Netherlands)

    Zeeland, van Y.R.A.; Spruit, B.M.; Rodenburg, T.B.; Riedstra, B.; Hierden, van Y.M.; Buitenhuis, A.J.; Korte, S.M.; Lumeij, J.T.

    2009-01-01

    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, to date

  5. 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.

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

    NARCIS (Netherlands)

    van Zeeland, Yvonne R. A.; Spruit, Berry M.; Rodenburg, T. Bas; Riedstra, Bernd; van Hierden, Yvonne M.; Buitenhuis, Bart; Korte, S. Mechiel; Lumeij, Johannes T.

    2009-01-01

    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, to date

  7. 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.

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

    NARCIS (Netherlands)

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

    2013-01-01

    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

  9. WHEN COMPASSION GROWS WINGS

    African Journals Online (AJOL)

    Nicky

    antiretroviral roll-out in full swing, the. WHEN COMPASSION GROWS WINGS. The free time and expertise given by its deeply committed core of professional volunteers. (including pilots) is the lifeblood of the operation. Red Cross Air Mercy Service volunteer, German national Dr Florian Funk, at the AMS Durban base.

  10. Twisted Winged Endoparasitoids

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 10. Twisted Winged Endoparasitoids - An Enigma for Entomologists. Alpana Mazumdar. General Article Volume 9 Issue 10 October 2004 pp 19-24. Fulltext. Click here to view fulltext PDF. Permanent link:

  11. 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.

  12. 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).

  13. 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)

  14. Melanin concentration gradients in modern and fossil feathers.

    Directory of Open Access Journals (Sweden)

    Daniel J Field

    Full Text Available In birds and feathered non-avian dinosaurs, within-feather pigmentation patterns range from discrete spots and stripes to more subtle patterns, but the latter remain largely unstudied. A ∼55 million year old fossil contour feather with a dark distal tip grading into a lighter base was recovered from the Fur Formation in Denmark. SEM and synchrotron-based trace metal mapping confirmed that this gradient was caused by differential concentration of melanin. To assess the potential ecological and phylogenetic prevalence of this pattern, we evaluated 321 modern samples from 18 orders within Aves. We observed that the pattern was found most frequently in distantly related groups that share aquatic ecologies (e.g. waterfowl Anseriformes, penguins Sphenisciformes, suggesting a potential adaptive function with ancient origins.

  15. The financial help given by the French government to LPG-fueled taxis; L'aide financiere de l'etat aux taxis GPL

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-02-01

    In the framework of its 'clean vehicle' air pollution abatement program, the French government has set up a financial help managed by the French agency of environment and energy mastery (Ademe) and devoted to taxi fleets which use LPG fuels. This brochure gives a general presentation of LPG-fueled vehicles (equipment, cost, service stations..) and explains the conditions of allocation of the help. (J.S.)

  16. 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.

  17. 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.

  18. 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.

  19. 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...... of mixture in the distribution of the observed FP and by studying the evolution of the proportion of very high FP along the sequence of 8 generations. This hypothesis is further supported by the fact that the gene transcription profile of the birds performing high FP differs from the profile of the other...

  20. Design Reference Missions (DRM): Integrated ODM 'Air-Taxi' Mission Features

    Science.gov (United States)

    Kloesel, Kurt; Starr, Ginn; Saltzman, John A.

    2017-01-01

    Design Reference Missions (DRM): Integrated ODM Air-Taxi Mission Features, Hybrid Electric Integrated System Testbed (HEIST) flight control. Structural Health, Energy Storage, Electric Components, Loss of Control, Degraded Systems, System Health, Real-Time IO Operator Geo-Fencing, Regional Noise Abatement and Trusted Autonomy Inter-operability.

  1. Sitting on the runway : current aircraft taxi times now exceed pre-9/11 experience

    Science.gov (United States)

    2008-05-01

    Several high profile incidents have focused attention on tarmac delays that resulted in air travelers spending long periods of time aboard aircraft waiting to either take off or move to a gate after landing. Taxi-time data collected by the Bure...

  2. 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 ...

  3. Late-Night Shared-Ride Taxi Transit in Ann Arbor, MI

    Science.gov (United States)

    1984-10-01

    The Ann Arbor Transportation Authority introduced Night Ride, a late-night shared-ride taxi transit service, in mid-March 1982. The service was provided through a contract with a local taxicab company and funded through a demonstration grant from the...

  4. 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.

  5. 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 ...

  6. Physical activity overcomes the effects of cumulative work time on hypertension prevalence among Brazilian taxi drivers.

    Science.gov (United States)

    Vieira, Marcelo C; Sperandei, Sandro; Reis, Arianne C

    2016-05-01

    The aim of this study was to assess the physical activity profile of taxi drivers and its relationship with hypertension prevalence in this group of workers. Cross sectional exploratory study. Between November 2008 and April 2009, 491 taxi drivers from Rio de Janeiro, Brazil, answered a questionnaire focusing on previous hypertension diagnosis, occupational characteristics and physical activity habits. Two logistic models were developed to determine risk factors related to hypertension and to find variables associated with a higher probability of sedentarism. Hypertension prevalence was 22.6%. The workload of the group investigated was high. Results indicate that 'age', 'Body Mass Index', 'physical activity', and 'years as a taxi driver' are related to the probability of hypertension. Physical activity was shown to be a protection factor for hypertension, even considering the deleterious effect of time as a taxi driver. Our results also determined that the practice of physical activity is influenced by age, level of education and workload. It is recommended that programs to combat sedentary lifestyles as well as measures to reduce workloads be developed as strategies to prevent hypertension.

  7. Portraits of the Postmodern Person in "Taxi Driver,""Raging Bull," and "The King of Comedy."

    Science.gov (United States)

    Mortimer, Barbara

    1997-01-01

    Argues that a postmodern theory of identity (i.e., the subject as coherent, integrated, discoverable self is a fiction of modernity) links Martin Scorsese's major films. Examines "Taxi Driver,""Raging Bull," and "King of Comedy." Concludes that these films articulate a major cultural shift and chronicle a…

  8. [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.

  9. [Morphogenesis and histogenesis of genetically based twin feathers in domestic pigeons (columba livia dom. L.)].

    Science.gov (United States)

    Hoffmann, Hans-Jürgen

    1969-06-01

    1. "Twin feathers" described for various domestic breeds of pigeons have been found in Oriental Rollers in 12 per cent of the sides of the tails during each of the breeding periods. 2. Each studied twin feather originates in a single follicle. It shows either one sheath ("split feather") or two sheaths ("double feather"). 72 per cent of the feathers have been found in the middles of the tails, 23 per cent in the middle of one side of the rows of rectrices. 3. Twin feathers grow either out of one papilla and one blastema having the ability for forming two shafts (split feathers) or from two separated papillae and blastemas lying in a single follicle cavity (double feathers). 4. The degree of splitting of split feathers is correlated to the position of the shaft primordia in the collars. Feathers of a degree of splitting exceeding 85 per cent have been found growing from collars with a pair of shaft primordia in an approximately diametrical and lateral position and a consequently large ramogenous zone between them, otherwise the two rhachis fuse during their development so that the follicle gives rise to a feather of a smaller degree of splitting. 5. The individual formation of a twin feather in a definite follicle will not vary in the succession of the feather generations, except for the rare non-reappearance of one twin of double feathers. Especially the degree of splitting has been observed to be invariable. 6. Generally the material of a twin feather is augmented compared to the symmetrically situated feather of the opposite side of the tail. The weight and area of a double feather is doubled, the weights of split feathers are significantly increased, the areas only of feathers with a degree of splitting exceeding 85 per cent. 7. Similar principles may be stated for twin downs of nestlings, but a great number of twin downs with mutual filaments has been observed. In the first generation of contour feathers, the twin downs are generally followed by twin feathers

  10. 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

    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.

  11. 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...

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

    Science.gov (United States)

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

    2011-08-01

    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±0.30μg/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±36.7ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910±386ng/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±44.7ng/g) and eggs (161±36.7ng/g) may pose a risk if consumed

  13. Clinical correlation of nonalcoholic fatty liver disease in a Chinese taxi drivers population in Taiwan: Experience at a teaching hospital

    Science.gov (United States)

    2011-01-01

    Background To explore any gender-related differences in the prevalence of conditions-associated with non-alcoholic fatty liver disease (NAFLD) among Taiwanese taxi drivers in Taipei, Taiwan. Methods We studied 1635 healthy taxi drivers (1541 males and 94 females) who volunteered for physical check-ups in 2006. Blood samples and ultrasound fatty liver sonography results were collected. Results The prevalence of NAFLD was 66.4% and revealed no statistically significant decrease with increasing age (p = 0.58). Males exhibited a greater prevalence of NAFLD than did females (67.5% vs 47.9%, p taxi drivers. PMID:21878129

  14. 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.

  15. The prevalence of fatigue and associated health and safety risk factors among taxi drivers in Singapore.

    Science.gov (United States)

    Lim, See Ming; Chia, Sin Eng

    2015-02-01

    Driver fatigue is one of the biggest health and safety concerns within the road transport sector. This study aimed to find out the prevalence of fatigue among taxi drivers in Singapore, to better understand the general working and health conditions of this group of people and to determine the risk factors associated with fatigued driving. A total of 340 taxi drivers were randomly selected for participation in this self-administered questionnaire survey, with height and weight measurements. The response rate was 68.2%. The survey consisted of four main categories: personal particulars; social habits; work patterns and sleep profile; and Epworth Sleepiness Scale, which was used to estimate the level of daytime sleepiness and fatigue. Multiple logistic regression analysis was used to estimate the adjusted odd ratios and 95% confidence intervals associated with the risk factors related to fatigue among the taxi drivers. A high proportion of the taxi drivers were obese and had self-reported hypertension, diabetes mellitus and high cholesterol. Driver fatigue was associated with very poor/poor self-rating of the quality of sleep, having an additional part-time job, drinking three or more caffeinated drinks daily, and driving more than 10 hours a day. We hope that the findings of the present study will improve the awareness regarding the work and health conditions of taxi drivers, and contribute toward the effort to achieve a healthier workforce. A lower prevalence of fatigued driving will lead to lower risks of road traffic accidents, decreased economic loss, increased productivity, and safer roads for all.

  16. An investigation of behavioural adaptation to airbags and antilock brakes among taxi drivers.

    Science.gov (United States)

    Sagberg, F; Fosser, S; Saetermo, I A

    1997-05-01

    Previous research has indicated that safety measures may lead to behavioural adaptation (also termed risk compensation) among road users, partly or completely offsetting the intended safety effects. There is, however, limited knowledge about characteristics of safety measures possibly determining the occurrence of behavioural adaptation. The present study addresses the relationship of driving behaviour to two different kinds of in-car safety equipment, airbags and antilock braking systems (ABS). It is hypothesized that accident-reducing measures like ABS are compensated for to a larger extent than injury-reducing measures like an airbag. On-road unobtrusive measurements of speed, headway, lane occupancy, lane changes, and variability of lateral position were performed on 213 taxis, on the basis of video recordings of traffic travelling to Oslo airport. The behavioural data were matched to questionnaire information collected when the taxis arrived at the airport. In addition to information regarding ABS and airbags, the drivers reported personal background information and answered questions about driving behaviour. Taxis with ABS had significantly shorter time headways than taxis without ABS. There were no relationships with speed, possibly because dense traffic during the observation period may have prevented the drivers from driving at their preferred speed. Simple comparisons also showed fewer lane changes and a lower rate of seat-belt use among drivers of taxis with ABS. However, multiple regression analyses indicated that the latter effects might be explained by driver background factors or by car characteristics other than ABS or airbag. The headway results support the hypothesis of larger compensation for accident-reducing than for injury-reducing measures.

  17. Energetics and optimum motion of oscillating lifting surfaces. [energy losses of rigid wings

    Science.gov (United States)

    Ahmadi, A. R.; Widnall, S. E.

    1983-01-01

    Low-frequency, unsteady, lifting-line theory is used to characterize the energetics and optimum motion of an unswept rigid wing oscillating harmonically in an inviscid, incompressible flow. The energetics calculations account for the leading edge suction force, the power absorbed in the wing oscillations, and the energy loss rate produced by vortex shedding. Optimization is achieved by minimizing the average energy loss rate in relation to a given thrust, and a unique solution is found in the three dimensional case for low, reduced frequencies. The two-dimensional solution is nonunique, a condition which is examined in terms of the normal modes of the energy loss rate matrix. An invisible mode with a hydrodynamic efficiency of 100 pct is obtained in the two-dimensional case, causing the nonuniqueness of the solution by yielding no fixed positive thrust through perfect unsteady feathering.

  18. Perseus B Taxi Tests in Preparation for a New Series of Flight Tests

    Science.gov (United States)

    1998-01-01

    The Perseus B remotely piloted aircraft taxis on the runway at Edwards Air Force Base, California, before a series of development flights at NASA's Dryden flight Research Center. The Perseus B is the latest of three versions of the Perseus design developed by Aurora Flight Sciences under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus

  19. Towards a quantitative indicator of feather disruption following the cleansing of oiled birds.

    Science.gov (United States)

    Bigger, Stephen W; Ngeh, Lawrence N; Dann, Peter; Orbell, John D

    2017-07-15

    A computer-based imaging method for determining feather microstructure coherency following a cleansing treatment, was developed, calibrated and trialled on Mallard Duck (Anas platyrhyhchos) feathers. The feathers were initially contaminated with a light crude oil and then cleansed by either detergent (Deacon 90) treatment or, alternatively, by magnetic particle technology (MPT) using iron powder. The imaging method provides a single quantitative parameter for the coherence of feather microstructure and the results confirm that MPT treatment imparts less disruption to the feather microstructure than detergent treatment. It is proposed that this imaging method can be developed and implemented for the assessment of feather disruption and possibly damage, either for the trialling of different treatment protocols, or as a tool during the rehabilitation process, along with other such indicators, to give a more comprehensive assessment of feather condition than is currently available. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Melanosomes or Microbes: Testing an Alternative Hypothesis for the Origin of Microbodies in Fossil Feathers

    Science.gov (United States)

    Moyer, Alison E.; Zheng, Wenxia; Johnson, Elizabeth A.; Lamanna, Matthew C.; Li, Da-Qing; Lacovara, Kenneth J.; Schweitzer, Mary H.

    2014-03-01

    Microbodies associated with fossil feathers, originally attributed to microbial biofilm, have been reinterpreted as melanosomes: pigment-containing, eukaryotic organelles. This interpretation generated hypotheses regarding coloration in non-avian and avian dinosaurs. Because melanosomes and microbes overlap in size, distribution and morphology, we re-evaluate both hypotheses. We compare melanosomes within feathers of extant chickens with patterns induced by microbial overgrowth on the same feathers, using scanning (SEM), field emission (FESEM) and transmission (TEM) electron microscopy. Melanosomes are always internal, embedded in a morphologically distinct keratinous matrix. Conversely, microbes grow across the surface of feathers in continuous layers, more consistent with published images from fossil feathers. We compare our results to both published literature and new data from a fossil feather ascribed to Gansus yumenensis (ANSP 23403). `Mouldic impressions' were observed in association with both the feather and sediment grains, supporting a microbial origin. We propose criteria for distinguishing between these two microbodies.

  1. 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.

  2. Design optimization of deployable wings

    Science.gov (United States)

    Gaddam, Pradeep

    Morphing technology is an important aspect of UAV design, particularly in regards to deployable systems. The design of such system has an important impact on the vehicle's performance. The primary focus of the present research work was to determine the most optimum deployable wing design from 3 competing designs and develop one of the deployable wing designs to test in the research facility. A Matlab code was developed to optimize 3 deployable wing concepts inflatable, inflatable telescopic and rigid-folding wings based on a sequential optimization strategy. The constraints that were part of the code include the packaging constraints during its stowed state, fixed length of the deployed section and the minimum L/D constraint. This code resulted in determining the optimum weight of all the 3 designs, the most optimum weight design is the inflatable wing design. This is a result of the flexible skin material and also due to no rigid parts in the deployed wing section. Another goal of the research involved developing an inflatable telescopic wing. The prototype was tested in a wind tunnel, while the actual wing was tested in the altitude chamber to determine the deployment speed, input pressure, analyze and predict the deployment sequence and behavior of the wing at such high wind speeds and altitudes ranging from 60,000 ft to 90,000 ft. Results from these tests allowed us to conclude the deployment sequence of the telescopic wing followed from the root to the tip section. The results were used to analyze the deployment time of the wing. As expected the deployment time decreased with an increase in input pressure. The results also show us that as the altitude increases, the deployment speed of the wing also increased. This was demonstrated when the wing was tested at a maximum altitude pressure of 90,000ft, well above the design altitude of 60,000ft.

  3. Low Aspect-Ratio Wings for Wing-Ships

    DEFF Research Database (Denmark)

    Filippone, Antonino; Selig, M.

    1998-01-01

    Flying on ground poses technical and aerodynamical challenges. The requirements for compactness, efficiency, manouverability, off-design operation,open new areas of investigations in the fieldof aerodynamic analysis and design. A review ofthe characteristics of low-aspect ratio wings, in- and out...... of ground, is presented. It is shownthat the performance of such wings is generally inferior to that of slender wings, although in ground placement can yield substantial improvements in the aerodynamic efficiency....

  4. The disposition of oxytetracycline to feathers after poultry treatment

    NARCIS (Netherlands)

    Berendsen, B.J.A.; Bor, G.; Gerritsen, H.W.; Jansen, L.J.M.; Zuidema, T.

    2013-01-01

    In the combat against bacterial resistance, there is a clear need to check the use of antibiotics in animal husbandry, including poultry breeding. The use of chicken feathers as a tool for the detection of use of antibiotics was investigated. An extraction method for the analysis of oxytetracycline

  5. Repeatability of feather mite prevalence and intensity in passerine birds.

    Directory of Open Access Journals (Sweden)

    Javier Diaz-Real

    Full Text Available Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and approaches were made to estimate R and adjusted repeatability (R(adj after controlling for potential confounding factors (breeding period, weather, habitat, spatial autocorrelation and researcher identity. The prevalence of feather mites was moderately repeatable (R = 0.26-0.53; R(adj = 0.32-0.57; smaller values were found for intensity (R = 0.19-0.30; R(adj = 0.18-0.30. These moderate repeatabilities show that prevalence and intensity of feather mites differ among species, but also that the high variation within species leads to considerable overlap among bird species. Differences in the prevalence and intensity of feather mites within bird species were small among habitats, suggesting that local factors are playing a secondary role. However, effects of local climatic conditions were partially observed for intensity.

  6. rights reserved Determination of the Viability of Chicken Feather as ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Attribution License (CCL), which permits unrestricted use, distribution, and reproduction in any medium, provided the .... Belarmino et al, 2012). Feather barbs show honeycomb hollow shaped hollow cells in the cross- section direction, the presence of a honeycomb structure will provide for the accumulations of liquids.

  7. Mercury bioaccumulation in Southern Appalachian birds, assessed through feather concentrations

    Science.gov (United States)

    Rebecca Hylton Keller; Lingtian Xie; David B. Buchwalter; Kathleen E. Franzreb; Theodore R Simons

    2014-01-01

    Mercury contamination in wildlife has rarely been studied in the Southern Appalachians despite high deposition rates in the region. From 2006 to 2008 we sampled feathers from 458 birds representing 32 species in the Southern Appalachians for total mercury and stable isotope ä 15N. Mercury concentrations (mean ± SE) averaged 0.46...

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

    African Journals Online (AJOL)

    Yomi

    2012-01-31

    Jan 31, 2012 ... proteases enzymes, release the free amino acids from keratinous proteins. Keratin is an insoluble, high stable protein found mostly in feathers, wool, nails and hairs of vertebrates (Shih, 1993). Keratin is resistant to the common proteolytic enzymes, papain, pepsin and trypsin. (Papadopoulos et al., 1986).

  9. 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.

  10. Applying FEATHERS for Travel Demand Analysis: Model Considerations

    Directory of Open Access Journals (Sweden)

    Qiong Bao

    2018-01-01

    Full Text Available Activity-based models of travel demand have received considerable attention in transportation planning and forecasting over the last few decades. FEATHERS (The Forecasting Evolutionary Activity-Travel of Households and their Environmental Repercussions, developed by the Transportation Research Institute of Hasselt University, Belgium, is a micro-simulation framework developed to facilitate the implementation of activity-based models for transport demand forecasting. In this paper, we focus on several model considerations when applying this framework. First, the way to apply FEATHERS on a more disaggregated geographical level is investigated, with the purpose of obtaining more detailed travel demand information. Next, to reduce the computation time when applying FEATHERS on a more detailed geographical level, an iteration approach is proposed to identify the minimum size of the study area needed. In addition, the effect of stochastic errors inherently included in the FEATHERS framework is investigated, and the concept of confidence intervals is applied to determine the minimum number of model runs needed to minimize this effect. In the application, the FEATHERS framework is used to investigate the potential impact of light rail initiatives on travel demand at a local network in Flanders, Belgium. In doing so, all the aforementioned model considerations are taken into account. The results indicate that by integrating a light rail network into the current public transport network, there would be a relatively positive impact on public transport-related trips, but a relatively negative impact on the non-motorized-mode trips in this area. However, no significant change is found for car-related trips.

  11. 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

  12. 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

  13. Piscivory in the feathered dinosaur Microraptor.

    Science.gov (United States)

    Xing, Lida; Persons, W Scott; Bell, Phil R; Xu, Xing; Zhang, Jianping; Miyashita, Tetsuto; Wang, Fengping; Currie, Philip J

    2013-08-01

    The largest specimen of the four-winged dromaeosaurid dinosaur Microraptor gui includes preserved gut contents. Previous reports of gut contents and considerations of functional morphology have indicated that Microraptor hunted in an arboreal environment. The new specimen demonstrates that this was not strictly the case, and offers unique insights into the ecology of nonavian dinosaurs early in the evolution of flight. The preserved gut contents are composed of teleost fish remains. Several morphological adaptations of Microraptor are identified as consistent with a partially piscivorous diet, including dentition with reduced serrations and forward projecting teeth on the anterior of the dentary. The feeding habits of Microraptor can now be understood better than that of any other carnivorous nonavian dinosaur, and Microraptor appears to have been an opportunistic and generalist feeder, able to exploit the most common prey in both the arboreal and aquatic microhabitats of the Early Cretaceous Jehol ecosystem. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  14. 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

    2014-04-01

    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. 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. 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. 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. Taxi drivers' health was poor in our survey. Thus, using health education interventions to improve knowledge and change in behaviors are necessary and

  15. 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....

  16. 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.

  17. 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.

  18. Keratinolytic activity of Bacillus megaterium F7-1, a feather-degrading mesophilic bacterium.

    Science.gov (United States)

    Park, Geun-Tae; Son, Hong-Joo

    2009-01-01

    The aim of this study was to investigate environmental conditions affecting chicken feather degradation and keratinolytic enzyme production by Bacillus megaterium F7-1, a feather-degrading mesophilic bacterium. B. megaterium F7-1 degraded whole chicken feather completely within 7 days. The bacterium grew with an optimum at pH 7.0-11.0 and 25-40 degrees C, where maximum keratinolytic activity was also observed. The production of keratinolytic enzyme by B. megaterium F7-1 was inducible with feather. Keratinolytic enzyme production by B. megaterium F7-1 at 0.6% (w/v) skim milk was 468U/ml, which was about 9.4-fold higher than that without skim milk. The amount of keratinolytic enzyme production depended on feather concentrations. The degradation rate of autoclaved chicken feathers by cell-free culture supernatant was 26% after 24h of incubation, but the degradation of untreated chicken feathers was unsuccessful. B. megaterium F7-1 effectively degraded feather meal, duck feather and human nail, whereas human hair and sheep wool showed relatively low degradation rates. B. megaterium F7-1 presented high keratinolytic activity and was very effective in feather degradation, providing potential use for biotechnological processes of keratin hydrolysis.

  19. 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

    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.

  20. 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.

  1. The development of feather pecking behaviour and targeting of pecking in chicks from a high and low feather pecking line of laying hens

    NARCIS (Netherlands)

    Hierden, van Y.M.; Korte, S.M.; Ruesink, E.W.; Reenen, van C.G.; Engel, B.; Koolhaas, J.M.; Blokhuis, H.J.

    2002-01-01

    Large individual differences between adult laying hens in their propensity for feather pecking are known to exist. However, not much research has been carried out into the individual differences concerning the development of feather pecking behaviour. The purpose of this study was to investigate

  2. 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.

  3. 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.

  4. 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.

  5. 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.

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

    Science.gov (United States)

    Sakurai, Kotaro; Yamamoto, Junko; Kurita, Tsugiko; Takeda, Youji; Kusumi, Ichiro

    2014-01-01

    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.

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

    Science.gov (United States)

    Sakurai, Kotaro; Yamamoto, Junko; Kurita, Tsugiko; Takeda, Youji; Kusumi, Ichiro

    2014-01-01

    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. PMID:25667862

  8. Stiffness of desiccating insect wings

    Energy Technology Data Exchange (ETDEWEB)

    Mengesha, T E; Vallance, R R [Department of Mechanical Engineering, The George Washington University, 738 Phillips Hall, 801 22nd St NW, Washington, DC 20052 (United States); Mittal, R, E-mail: vallance@gwu.edu [Department of Mechanical Engineering, Johns Hopkins University, 126 Latrobe Hall, 3400 N Charles Street, Baltimore, MD 21218 (United States)

    2011-03-15

    The stiffness of insect wings is typically determined through experimental measurements. Such experiments are performed on wings removed from insects. However, the wings are subject to desiccation which typically leads to an increase in their stiffness. Although this effect of desiccation is well known, a comprehensive study of the rate of change in stiffness of desiccating insect wings would be a significant aid in planning experiments as well as interpreting data from such experiments. This communication presents a comprehensive experimental analysis of the change in mass and stiffness of gradually desiccating forewings of Painted Lady butterflies (Vanessa cardui). Mass and stiffness of the forewings of five butterflies were simultaneously measured every 10 min over a 24 h period. The averaged results show that wing mass declined exponentially by 21.1% over this time period with a time constant of 9.8 h, while wing stiffness increased linearly by 46.2% at a rate of 23.4 {mu}N mm{sup -1} h{sup -1}. For the forewings of a single butterfly, the experiment was performed over a period of 1 week, and the results show that wing mass declined exponentially by 52.2% with a time constant of 30.2 h until it reached a steady-state level of 2.00 mg, while wing stiffness increased exponentially by 90.7% until it reached a steady-state level of 1.70 mN mm{sup -1}. (communication)

  9. Clinical symptoms and related factors of obstructive sleep apnea among overweight and obese taxi drivers

    Directory of Open Access Journals (Sweden)

    Agus D. Susanto

    2015-12-01

    Full Text Available Background: Obstructive sleep apnea (OSA is common condition in commercial drivers while overweight and obesity as the most important risk factors. This study aimed to know the clinical symptoms and risk factors of OSA in overweight and obese taxi drivers in Jakarta, Indonesia. Methods: A cross-sectional study was done in 103 taxi drivers in Jakarta from November 2011–September 2013, by systematic random sampling from 10 taxi stations. Inclusion criteria were taxi drivers with body mass index (BMI which 23–29.9 and mild or moderate OSA. Portable polysomnography (PSG test was used to diagnose OSA. Parametric and nonparametric test were used in bivariate analysis. Logistic regression multivariable was used to final evaluate risk factors of OSA.Results: There were 54 (52.4% of 103 drivers with OSA and 49 (47.6% without OSA. Clinical symptoms found significantly (p<0.05 were snoring, unrefreshing sleep, occasional sleep while driving, and headache or nausea on waking up in the morning. Risk factors for OSA were increased BMI (OR=0.60, 95% CI=0.45–0.79, p=0.001, snoring history in the family (OR=4.92, 95% CI=1.82–13.31, p=0.002 and sleep duration <7 hours within 24 hours (OR=5.14, 95% CI=1.37–19.23, p=0.015.Conclusion: Clinical symptoms of OSA were snoring, unrefreshing sleep, occasional sleep while driving and headache or nausea on waking up in the morning. Risk factors of OSA were increased BMI, snoring history in the family and sleep duration <7 hours within 24 hours.

  10. 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......, victims or control hens based on weekly performance of feather pecking behaviour from age 0–23 weeks and plumage condition at age 23 weeks. After culling at 23 weeks of age, the lengths of ulna, tarsus and middle toe as well as the widths of tarsus and hock were measured twice in each side. Each trait...

  11. A biotechnological process for treatment and recycling poultry feathers as a feed ingredient.

    Science.gov (United States)

    Bertsch, A; Coello, N

    2005-10-01

    A strain of Kocuria rosea with keratinolytic capacity was cultured aerobically on submerged feathers to obtain a fermented feather meal (FFM). This FFM enriched with cells of K. rosea mainly contains crude protein (71%). The pepsin digestibility of the fermented product (88%) was similar to the value of the commercial feather meal and more than 70% greater that untreated feathers. The bacterial biomass improved the content of amino acids lysine (3.46%), histidine (0.94%) and methionine (0.69%). Additionally, the amino acid availability tested by in vivo assay was greater than commercial feather meal. The microbial cells also supplied carotenoid pigments to FFM (68 ppm). These results suggest that feather meal enriched with K. rosea may be useful in animal feeding as protein and pigment source.

  12. Coordinated Charging Strategy for Electric Taxis in Temporal and Spatial Scale

    Directory of Open Access Journals (Sweden)

    Yuqing Yang

    2015-02-01

    Full Text Available Currently, electric taxis have been deployed in many cities of China. However, the charging unbalance in both temporal and spatial scale has become a rising problem, which leads to low charging efficiency or charging congestion in different stations or time periods. This paper presents a multi-objective coordinated charging strategy for electric taxis in the temporal and spatial scale. That is, the objectives are maximizing the utilization efficiency of charging facilities, minimizing the load unbalance of the regional power system and minimizing the customers’ cost. Besides, the basic configuration of a charging station and operation rules of electric taxis would be the constraints. To tackle this multi-objective optimizing problems, a fuzzy mathematical method has been utilized to transfer the multi-objective optimization to a single optimization issue, and furthermore, the Improved Particle Swarm Optimization (IPSO Algorithm has been used to solve the optimization problem. Moreover, simulation cases are carried out, Case 1 is the original charging procedure, and Cases 2 and 3 are the temporal and spatial scale optimized separately, followed with Case 4, the combined coordinated charging. The simulation shows the significant improvement in charging facilities efficiency and users’ benefits, as well as the better dispatching of electric taxis’ charging loads.

  13. 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).

  14. 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.

  15. Predicting health risks of exposure to whole body vibration in the urban taxi drivers

    Directory of Open Access Journals (Sweden)

    Keykaous Azrah

    2016-09-01

    Full Text Available Introduction: Limited studies have been done to evaluate the whole-body vibration (WBV exposure experienced by Taxi drivers. Therefore, the aim of this study was to evaluate the exposure to whole body vibration and repeated shocks in urban taxi drivers and also to compare different methods of evaluation in this job environment. Material and Method: Measurement and evaluation process were conducted in accordance with procedure of the ISO 2631-1 and ISO 2631-5 standards. The measurements were done by SVAN 958 Sound and Vibration Analyzer and using tri-axial accelerometer centered on the contact surface between the seat and the driver in 9 taxis.   Result: The measurements done according to ISO 2631-1 method showed greater risk compared to Daily Equivalent Static Compression Dose, Sed, presented in ISO 2631-5. Calculated daily exposure durations for exposure action level in root-mean square, vibration dose value, and daily equivalent static compressive stress methods were 4.55, 3.54 and 31.70 hours, respectively. Conclusion: The large differences in estimated exposure durations of action limits and permissible limits resulted by different methods reflect the inconsistency of the selected evaluation methods. Therefore, future research is necessary to amend the limits presented in the standard.

  16. Navigation around London by a taxi driver with bilateral hippocampal lesions.

    Science.gov (United States)

    Maguire, Eleanor A; Nannery, Rory; Spiers, Hugo J

    2006-11-01

    The time-scale of hippocampal involvement in supporting episodic memory remains a keenly debated topic, with disagreement over whether its role is temporary or permanent. Recently, there has been interest in how navigation by hippocampally-compromised patients in environments learned long ago speaks to this issue. However, identifying patients with damage that is primarily hippocampal, control subjects matched for navigation experience, and testing their in situ navigation, present substantial problems. We met these challenges by using a highly accurate and interactive virtual reality simulation of central London (UK) to assess the navigation ability of a licensed London taxi driver who had sustained bilateral hippocampal damage. In this test, patient TT and matched control taxi drivers drove a virtual London taxi along the streets they had first learned 40 years before. We found that the hippocampus is not required for general orientation in the city either in first person or survey perspectives, detailed topographical knowledge of landmarks and their spatial relationships, or even for active navigation along some routes. However, in his navigation TT was very reliant on main artery or 'A' roads, and became lost when navigation depended instead on non-A roads. We conclude that the hippocampus in humans is necessary for facilitating navigation in places learned long ago, particularly where complex large-scale spaces are concerned, and successful navigation requires access to detailed spatial representations.

  17. Exploring knowledge and attitudes of taxi drivers with regard to obstructive sleep apnoea syndrome.

    Science.gov (United States)

    Firestone, Ridvan T; Gander, Philippa H

    2010-08-27

    To examine the attitudes of taxi drivers towards symptoms of obstructive sleep apnoea syndrome (OSAS), and to determine whether these attitudes could influence their health and safety as a professional driver. Qualitative research based on three focus groups conducted in Wellington, New Zealand. Participants were 27 taxi drivers who had a high pre-test risk for obstructive sleep apnoea. Assignment to focus groups was based on self-identification as being Maori and Pacific peoples, New Zealand European, or non-Maori and non-Pacific. Participants described avoidance of health issues and dissatisfaction with their general practitioners. These attitudes were attributable to: (i) lack of knowledge, (ii) deliberate avoidance, and (iii) fear of loss of employment and income. The attitudes and level of knowledge of the focus group participants lead us to make the following recommendations. Drivers need systematic education about the effects of insufficient sleep and of OSAS on driving skills and safety. Taxi managers and drivers should cooperate to develop and implement safe driving policies to manage driver fatigue. Clear guidelines are need for drivers, managers, and healthcare professionals on the diagnosis and treatment of sleep disorders among drivers, and their potential consequences for driver licensing.

  18. New York City taxi drivers’ knowledge and perceptions of the Affordable Care Act

    Science.gov (United States)

    Gany, Francesca; Flores, Cristina; Winkel, Gary; Alam, Ishtiaq; Genoff, Margaux

    2015-01-01

    Objectives This study was conducted to assess New York City taxi drivers’ knowledge and perceptions of the Affordable Care Act (ACA). Methods A cross-sectional street-intercept study design was used to assess drivers’ knowledge about the ACA. A 146-item questionnaire was administered from September 12 to December 6, 2013 to 175 yellow taxi and for-hire vehicle drivers. Results 91% of drivers were foreign-born; 50% were uninsured. Mean knowledge about the ACA was quite low; 78% of the sample either knew nothing or only a little bit about the ACA. 77% wanted more information about the ACA. Greater English proficiency, more years driving a taxi, and knowledge of having or not having a pre-existing health condition (versus not knowing) were related to higher ACA knowledge levels. Knowledge of a pre-existing condition (whether they had one or not) compared to those who lacked such knowledge was also an important predictor of the perception of whether the ACA would have a positive impact. Conclusions To facilitate enrollment, efforts should focus on occupationally-focused initiatives that educate drivers at their places of work and leisure, to raise the overall knowledge levels and enrollment of the community. PMID:25976215

  19. Occupational and Personal Determinants of Musculoskeletal Disorders among Urban Taxi Drivers in Ghana

    Science.gov (United States)

    Abledu, J. K.; Offei, E. B.; Abledu, G. K.

    2014-01-01

    Background. There is a lack of epidemiological data on musculoskeletal disorders (MSDs) among occupational drivers in Ghana. The present study seeks to estimate the prevalence, body distribution, and occupational and personal determinants of MSDs in a sample of taxi drivers in the Accra Metropolis of Ghana. Methods. A total of 210 participants were enrolled in this cross-sectional study. All the participants were evaluated by using a semistructured questionnaire and the standardized Nordic Musculoskeletal Disorder Questionnaire. Results. The estimated prevalence of MSDs was 70.5%. The prevalence of the various MSD domains was as follows: lower back pain (34.3%), upper back pain (16.7%), neck pain (15.2%), shoulder pain (11.0%), knee pain (10.0%), hip/thigh pain (2.9%), elbow pain (4.8%), ankle/feet pain (2.4%), and wrist/hand pain (1.9%). Multiple logistic regression analysis of the data showed that participants who were employee drivers, drove taxi more than 12 hours per day or at least 5 days per week, perceived their job as stressful, and were dissatisfied with their job were at a greater risk of developing MSDs. Conclusions. These findings call for preventive strategies and safety guidelines in order to reduce the incidence of MSDs among urban taxi drivers in Ghana. PMID:27379297

  20. Blood lead and erythrocyte delta-aminolevulinic acid dehydratase levels in Manchester taxi drivers.

    Science.gov (United States)

    Flindt, M L; King, E; Walsh, D B

    1976-05-01

    Among 40 Manchester taxi drivers the mean blood lead was 1.10 mumol/1 (22.8 mug per 100 ml). The mean erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity among 34 of them was 30.1 units. No significant association was found between the blood lead levels and erythrocyte ALAD activity in these 34 men. No significant association was found between either blood lead elvels or erythrocyte ALAD activity and duration of service or weekly mileage as a taxi driver or with drinking or smoking habits, or age. The mean blood lead of those with homes in the north east quadrant of the city was higher than of those living elsewhere but the difference was not statistically significant. Although there was no correlation between blood lead levels and the source of domestic water, the mean blood lead of those with lead domestic plumbing was appreciably higher than the level of those with copper plumbing. There was no indication that, by virtue of their occupation, the taxi drivers were liable to greater lead absorption than their fellow-citizens.

  1. Taxi Drivers: A Target Population for the Prevention of Transmissible Disease?

    Science.gov (United States)

    Limper, Heather M; Burns, Jennifer L; Alexander, Kenneth A

    2016-04-01

    We set out to assess the feasibility and uptake of an on-site influenza vaccination campaign targeting taxi drivers in airport taxicab lots in Chicago, Illinois. Influenza vaccine was provided by the Chicago Department of Public Health as this event aligned with ongoing efforts to provide influenza vaccinations throughout the city. Clinicians and clinic support staff were volunteers recruited from the University of Chicago Medicine and incorporated nursing staff, physicians, physician residents, and administrative support. Together, this allowed for a cost-effective approach to provide free influenza vaccines to the primarily uninsured taxi driver population. During these events, 545 taxi drivers received influenza vaccine in 2012 while 354 drivers were immunized in 2013. Nearly all drivers reported uninsured or under-insured status. The ability to use volunteers and healthcare organization's desires to meet the needs of the community, in collaboration with often under-staffed but highly dedicated local health departments have the potential to offer valuable public health services to underserved members of the community. Educational initiatives targeting vaccine hesitancy and misinformation may be necessary to improve immunization coverage among this population.

  2. Step On It! - Workplace cardiovascular risk assessment of New York City yellow taxi drivers

    Science.gov (United States)

    Gany, Francesca; Bari, Sehrish; Gill, Pavan; Ramirez, Julia; Ayash, Claudia; Loeb, Rebecca; Aragones, Abraham; Leng, Jennifer

    2015-01-01

    Background Multiple factors associated with taxi driving can increase the risk of cardiovascular disease (CVD) in taxi drivers. Methods This paper describes the results of Step On It!, which assessed CVD risk factors among New York City taxi drivers at John F. Kennedy International Airport. Drivers completed an intake questionnaire and free screenings for blood pressure, glucose and body mass index (BMI). Results 466 drivers participated. 9% had random plasma glucose values >200 mg/dl. 77% had elevated BMIs. Immigrants who lived in the U.S. for >10 years had 2.5 times the odds (CI: 1.1–5.9) of having high blood pressure compared to newer immigrants. Discussion Abnormalities documented in this study were significant, especially for immigrants with greater duration of residence in the U.S., and underscore the potential for elevated CVD risk in this vulnerable population, and the need to address this risk through frameworks that utilize multiple levels of intervention. PMID:25680879

  3. Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Javad Golhosseini*

    2015-06-01

    Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOCs 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.

  4. Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  6. 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.

  7. 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...

  8. Poultry feather wastes recycling possibility as soil nutrient

    Directory of Open Access Journals (Sweden)

    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

  9. Repeatability of Feather Mite Prevalence and Intensity in Passerine Birds

    OpenAIRE

    Diaz-Real, Javier; Serrano, David; Pérez-Tris, Javier; Fernández-González, Sofía; Bermejo, Ana; Calleja, Juan A.; De la Puente, Javier; De Palacio, Diana; Martínez, José L.; Moreno-Opo, Rubén; Ponce, Carlos; Frías, Óscar; Tella, José L.; Møller, Anders P.; Figuerola, Jordi

    2014-01-01

    Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R) of the intensity and the prevalence of feather mites to partition within- and among-host species variance compo...

  10. Sulfitolytic and keratinolytic potential of Chryseobacterium sp. RBT revealed hydrolysis of melanin containing feathers

    OpenAIRE

    Gurav, Ranjit G.; Tang, Jingchun; Jadhav, Jyoti P.

    2016-01-01

    In black feathers, melanin is embedded in keratin matrix that makes feather more resistance to the microbial degradation. Chryseobacterium sp. RBT previously isolated from the poultry waste disposable site revealed strong sulfitolytic and keratinolytic activities. Maximum keratinase activity was observed at 48?h (89.12?U?ml?1) showed 83?% of native black feather degradation. The concentration of free sulfhydryl groups released during degradation was 0.648???10?4?M?(12?h), 2.144???10?4?M?(96?h...

  11. 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.

  12. 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.

  13. Archaeopteryx feathers and bone chemistry fully revealed via synchrotron imaging.

    Science.gov (United States)

    Bergmann, U; Morton, R W; Manning, P L; Sellers, W I; Farrar, S; Huntley, K G; Wogelius, R A; Larson, P

    2010-05-18

    Evolution of flight in maniraptoran dinosaurs is marked by the acquisition of distinct avian characters, such as feathers, as seen in Archaeopteryx from the Solnhofen limestone. These rare fossils were pivotal in confirming the dinosauria-avian lineage. One of the key derived avian characters is the possession of feathers, details of which were remarkably preserved in the Lagerstätte environment. These structures were previously simply assumed to be impressions; however, a detailed chemical analysis has, until now, never been completed on any Archaeopteryx specimen. Here we present chemical imaging via synchrotron rapid scanning X-ray fluorescence (SRS-XRF) of the Thermopolis Archaeopteryx, which shows that portions of the feathers are not impressions but are in fact remnant body fossil structures, maintaining elemental compositions that are completely different from the embedding geological matrix. Our results indicate phosphorous and sulfur retention in soft tissue as well as trace metal (Zn and Cu) retention in bone. Other previously unknown chemical details of Archaeopteryx are also revealed in this study including: bone chemistry, taphonomy (fossilization process), and curation artifacts. SRS-XRF represents a major advancement in the study of the life chemistry and fossilization processes of Archaeopteryx and other extinct organisms because it is now practical to image the chemistry of large specimens rapidly at concentration levels of parts per million. This technique has wider application to the archaeological, forensic, and biological sciences, enabling the mapping of "unseen" compounds critical to understanding biological structures, modes of preservation, and environmental context.

  14. 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.

  15. 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.

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

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    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.

  17. Lifestyle risk factors for cardiovascular disease and diabetic risk in a sedentary occupational group: the Galway taxi driver study.

    Science.gov (United States)

    Martin, W P; Sharif, F; Flaherty, G

    2016-05-01

    Taxi drivers are at increased risk of cardiovascular disease (CVD), something which persists after correcting for the overrepresentation of traditional risk factors for CVD in this cohort. The contribution of lifestyle risk factors to this residually elevated CVD risk remains under-evaluated. We aimed to determine the prevalence of lifestyle risk factors for CVD, self-reported medical risk factors for CVD, and future risk of type 2 diabetes amongst Irish taxi drivers. Male taxi drivers with no history of CVD and type 2 diabetes and working in Galway city in the west of Ireland were invited to participate. Physical activity levels, dietary patterns, anthropometry, smoking, hypertension, hypercholesterolaemia, and Finnish Diabetes Risk Score (FINDRISC) values were recorded in a cross-sectional manner. 41 taxi drivers (mean age 56.7 ± 9.8 years) participated. 37 % were insufficiently active based on self-report, although only 8 % objectively achieved 10, 000 steps per day. Mean modified Mediterranean diet score (mMDS) was 4.6 ± 2.2, and only 13 % of participants had a normal body mass index (BMI) or waist circumference (WC). Those who worked for taxi companies tended to have a higher BMI (p = .07) and WC (p = .04) by multivariable regression. 22 % were current smokers, although a quit rate of 72 % was observed amongst the 78 % of taxi drivers who had ever smoked. 25 % were at high or very high risk of future type 2 diabetes. Lifestyle risk factors for CVD and dysglycaemia are prevalent amongst Irish taxi drivers.

  18. 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.

  19. Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds

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    David J. Bottjer

    2012-09-01

    Full Text Available At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern equivalent. The early stepwise evolution of apparently modern feathers occurred within Maniraptora, basal to the avian transition, with asymmetrical pennaceous feathers suited for flight present in the most basal recognized avian, Archaeopteryx lithographica. The number of extinct primitive feather morphotypes recognized among non-avian dinosaurs continues to increase with new discoveries; some of these resemble feathers present in basal birds. As a result, feathers between phylogenetically widely separated taxa have been described as homologous. Here we examine the extinct feather morphotypes recognized within Aves and compare these structures with those found in non-avian dinosaurs. We conclude that the “rachis dominated” tail feathers of Confuciusornis sanctus and some enantiornithines are not equivalent to the “proximally ribbon-like” pennaceous feathers of the juvenile oviraptorosaur Similicaudipteryx yixianensis. Close morphological analysis of these unusual rectrices in basal birds supports the interpretation that they are modified pennaceous feathers. Because this feather morphotype is not seen in living birds, we build on current understanding of modern feather molecular morphogenesis to suggest a hypothetical molecular developmental model for the formation of the rachis dominated feathers of extinct basal birds.

  20. 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

  1. Flapping Wing Micro Air Vehicle Wing Manufacture and Force Testing

    Science.gov (United States)

    2011-03-03

    manufacturing techniques have been developed by various universities for research on Flapping Wing Micro Air Vehicles. Minimal attention though is given...collected at 2kHz (www.polytec.com/psv3d). A 0.25V band-limited white noise input signal is input to a Bogen HTA -125 High Performance Amplifier, which...manufacturing techniques have been developed by various universities for research on Flapping Wing Micro Air Vehicles. Minimal attention though is given

  2. Signal balancing by the CetABC and CetZ chemoreceptors controls energy taxis in Campylobacter jejuni.

    Directory of Open Access Journals (Sweden)

    Mark Reuter

    Full Text Available The coupling of environmental sensing to flagella-mediated directed motility allows bacteria to move to optimum environments for growth and survival, either by sensing external stimuli (chemotaxis or monitoring internal metabolic status (energy taxis. Sensing is mediated by transducer-like proteins (Tlp, either located in the membrane or in the cytoplasm, which commonly influence motility via the CheA-CheY chemotaxis pathway. In this study we have investigated the role of PAS-domain-containing intracellular Tlp-sensors in energy taxis of the food-borne pathogen Campylobacter jejuni, using plate- and tube-based assays utilising the conversion of the redox indicator dyes triphenyl tetrazolium chloride (TTC and resazurin. Inactivation of the genes encoding the Campylobacter Energy Taxis system (CetA (Tlp9 and CetB (Aer2 in C. jejuni strain NCTC 11168 resulted in reduced taxis. Inactivation of the cj1191c gene, encoding the CetB homolog CetC (Aer1, did not affect taxis per se, but the cetC gene complemented a cetB mutant in trans, indicating that CetC can form a functional signal transduction complex with CetA in the absence of CetB. Inactivation of both CetB and CetC resulted in greatly reduced taxis confirming the role of CetC in energy taxis. Inactivation of the cj1110c gene, encoding Tlp8 (CetZ, a cytoplasmic sensor with two PAS-domains, resulted in increased taxis, a phenotype opposite to that of CetAB. Inactivation of the cheA gene resulted in the same overall phenotype as the cetAB mutant in both wild-type and cetZ backgrounds, suggesting that both systems use the CheA system for signal transduction. Absence of both CetAB and CetZ resulted in the cetAB taxis phenotype, suggesting that CetZ is subordinate to CetAB. In conclusion, we present evidence that C. jejuni balances the input from two counteracting PAS-domain-containing sensory systems to position itself for optimal usage of energy resources.

  3. Protease production by the keratinolytic Bacillus sp. CL18 through feather bioprocessing.

    Science.gov (United States)

    Sobucki, Lisiane; Ramos, Rodrigo Ferraz; Daroit, Daniel Joner

    2017-10-01

    Bacillus sp. CL18 was investigated to propose a bioprocess for protease production using feathers as organic substrate. In feather broth (FB), containing feathers as sole organic substrate (1-100 g l -1 ), maximal protease production was observed at 30 g l -1 (FB30) after 6 days of cultivation, whereas increased feather concentrations negatively affected protease production and feather degradation. Protease production peaks were always observed earlier during cultivations than maximal feather degradation. In FB30, 80% of initial feathers mass were degraded after 7 days. Addition of glucose, sucrose, starch, yeast extract (2 g l -1 ), CaCl 2 , or MgCl 2 (10 mmol l -1 ) to FB30 decreased protease production and feather degradation. FB30 supplementation with NH 4 Cl (1 g l -1 ) resulted in less apparent negative effects on protease production, whereas peptone (2 g l -1 ) increased protease yields earlier during cultivations (3 days). Through a central composite design employed to investigate the effects of peptone and NH 4 Cl (0.5-4.5 g l -1 ) on protease production and feather degradation, FB30 supplementation with peptone and NH 4 Cl (0.5-1.1 g l -1 ) increased protease production within a shorter cultivation time (5 days) and hastened complete feather degradation (6 days). Feather bioconversion concurs with sustainable production of value-added products.

  4. Assessment of the effect of housing on feather damage in laying hens using IR thermography.

    Science.gov (United States)

    Pichová, K; Bilčík, B; Košt'ál, L'

    2017-04-01

    Plumage damage represents one of the animal-based measures of laying hens welfare. Damage occurs predominantly due to age, environment and damaging pecking. IR thermography, due to its non-invasiveness, objectivity and repeatability is a promising alternative to feather damage scoring systems such as the system included in the Welfare Quality ® assessment protocol for poultry. The aim of this study was to apply IR thermography for the assessment of feather damage in laying hens kept in two housing systems and to compare the results with feather scoring. At the start of the experiment, 16-week-old laying hens (n=30) were divided into two treatments such as deep litter pen and enriched cage. During 4 months, feather damage was assessed regularly in 2-week intervals. One more single assessment was done nine and a half months after the start of the experiment. The feather damage on four body regions was assessed by scoring and IR thermography: head and neck, back and rump, belly, and underneck and breast. Two variables obtained by IR thermography were used: the difference between the body surface temperature and ambient temperature (ΔTB) and the proportion of featherless areas, which were defined as areas with a temperature >33.5°C. Data were analyzed using a GLM model. The effects of housing, time, region and their interactions on feather damage, measured by the feather scoring and by both IR thermography measures, were all significant (PIR thermography assessment of the feather damage revealed differences between hens kept in different housing systems in agreement with the feather scoring. In conclusion, it was demonstrated that the IR thermography is a useful tool for the assessment of poultry feather cover quality that is not biased by the subjective component and provides higher precision than feather damage scoring.

  5. 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.

  6. Commuting and communication: An investigation of taxi drivers’ experiences, attitudes and beliefs about passengers with communication disorders

    Science.gov (United States)

    Green, Sianne; Khoza-Shangase, Katijah

    2015-01-01

    Background One of the most popular means of public transport within South Africa is mini-bus taxis. Objectives As South Africa is made up of diverse cultures, religions and beliefs, the aim of this study was to explore Johannesburg based taxi drivers’ experiences of beliefs about, and attitudes towards passengers who have a communication disability. Method Semi-structured interviews were conducted with 10 mini-bus taxi drivers. Results Interviews revealed that almost all the taxi drivers had encountered passengers with a communication disability, and had an awareness of passengers with a hearing disability as opposed to a speech disability. Furthermore mini-bus taxi drivers generally held a positive view of their passengers with a communication disability. Conclusion Study findings contribute to existing literature within the fields of speech pathology and audiology, advocacy groups and policy makers, particularly research studies on participation experiences of persons with communication disabilities related to transportation access. The results of the study should also provide a foundation for disability policy development initiatives with the aim of increasing levels of public awareness. PMID:28730016

  7. Research of Morphing Wing Efficiency

    National Research Council Canada - National Science Library

    Komarov, Valery

    2004-01-01

    This report results from a contract tasking Samara State Aerospace University (SSAU) as follows: The contractor will develop and investigate aerodynamic and structural weight theories associated with morphing wing technology...

  8. 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.

  9. 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

    Energy Technology Data Exchange (ETDEWEB)

    Jane Harms, N., E-mail: naomi.harms@usask.c [University of Saskatchewan, Western College of Veterinary Medicine, Department of Veterinary Pathology, 52 Campus Drive, Saskatoon, SK, S7N 5B4 (Canada); Fairhurst, Graham D., E-mail: graham.fairhurst@usask.c [University of Saskatchewan, Department of Biology, 112 Science Place, Saskatoon, SK, S7N 5E2 (Canada); Bortolotti, Gary R., E-mail: gary.bortolotti@usask.c [University of Saskatchewan, Department of Biology, 112 Science Place, Saskatoon, SK, S7N 5E2 (Canada); Smits, Judit E.G., E-mail: judit.smits@usask.c [University of Saskatchewan, Western College of Veterinary Medicine, Department of Veterinary Pathology, 52 Campus Drive, Saskatoon, SK, S7N 5B4 (Canada)

    2010-03-15

    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.

  10. 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.

  11. 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 poin...

  12. 41 CFR 301-10.306 - What will I be reimbursed if authorized to use a POV instead of a taxi between my residence and...

    Science.gov (United States)

    2010-07-01

    ... reimbursed if authorized to use a POV instead of a taxi between my residence and office to a common carrier terminal, or from my residence directly to a common carrier terminal on travel requiring an overnight stay... taxi between my residence and office to a common carrier terminal, or from my residence directly to a...

  13. 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...

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. 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

  19. Metals in albatross feathers from Midway Atoll: Influence of species, age, and nest location

    Energy Technology Data Exchange (ETDEWEB)

    Burger, J.; Gochfeld, M.

    2000-03-01

    In this paper the authors examine the concentrations of metals (heavy metals, mercury, lead, cadmium, chromium, manganese, tin; and metalloids, arsenic and selenium), in the down and contour (body) feathers of half-grown young albatrosses, and contour feathers of one of their parents. They collected feathers from Laysan Diomedea immutabilis and black-footed Diomedea nigripes albatrosses from Midway Atoll in the central Pacific Ocean. The authors test the null hypotheses that there is no difference in metal levels as a function of species, age, feather type, and location on the island. Using linear regression they found significant models accounting for the variation in the concentrations of mercury, lead, cadmium, selenium, chromium, and manganese (but not arsenic or tin) as a function of feather type (all metals), collection location (all metals but lead), species (selenium only), and interactions between these factors. Most metals (except mercury, arsenic, and tin) were significantly higher in down than in the contour feathers of either chicks or adults. Comparing the two species, black-footed albatross chicks had higher levels of most elements (except arsenic) in their feathers and/or down. Black-footed adults had significantly higher levels of mercury and selenium. They also collected down and feathers from Laysan albatross chicks whose nests were close to buildings, including buildings with flaking lead paint and those that had been lead-abated.

  20. 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

  1. 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.

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

    African Journals Online (AJOL)

    Prices ranged from 5 soles for a small body feather to 160 soles for a main primary and we found handicrafts for sale at prices of up to 650 soles (featuring 6 feathers). We were offered a whole condor for sale at a market in Cusco for ... We also make recommendations for a strategy for controlling this illegal. September 2011.

  3. 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 ...

  4. 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.

  5. Predicting feather damage in laying hens during the laying period. Is it the past or is it the present?

    NARCIS (Netherlands)

    Haas, de E.N.; Bolhuis, J.E.; Jong, de I.C.; Kemp, B.; Janczak, A.M.; Rodenburg, T.B.

    2014-01-01

    Feather damage due to severe feather pecking (SFP) in laying hens is most severe during the laying period. However, SFP can develop at an early age and is influenced by early rearing conditions. In this study we assessed the risk factors during the rearing and laying period for feather damage at 40

  6. 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.

  7. 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

  8. Keratin based bioplastic film from chicken feathers and its characterization.

    Science.gov (United States)

    Ramakrishnan, Navina; Sharma, Swati; Gupta, Arun; Alashwal, Basma Yahya

    2018-01-07

    Plastics have been one of the highly valued materials and it plays an significant role in human's life such as in food packaging and biomedical applications. Bioplastic materials can gradually work as a substitute for various materials based on fossil oil. The issue like sustainability and environmental challenges which occur due to manufacturing and disposal of synthetic plastics can be conquering by bio-based plastics. Feathers are among the most inexpensive abundant, and renewable protein sources. Feathers disposal to the landfills leads to environmental pollutions and it results into wastage of 90% of protein raw material. Keratin is non-burning hydrophilic, and biodegradable due to which it can be applicable in various ways via chemical processing. Main objective of this research is to synthesis bioplastic using keratin from chicken feathers. Extracted keratin solution mixed with different concentration of glycerol (2 to 10%) to produce plastic films. The mixture was stirred under constant magnetic stirring at 60 °C for 5 h. The mixtures are then poured into aluminum weighing boat and dried in an oven at 60 °C for 24 h. The mechanical properties of the samples were tested and the physic-chemical properties of the bioplastic were studied. According to the results, Scanning Electron Microscopy test showed good compatible morphologies without holes, cavity and edge. The difference in chemical composition was analyzed using Fourier transform infrared spectroscopy (FTIR). The samples were also characterized by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-Ray diffraction (XRD) to check the thermal and crystallinity properties. Other than that, bioplastic made up from keratin with 2% of glycerol has the best mechanical and thermal properties. According to biodegradability test, all bioplastic produced are proven biodegradable. Therefore, the results showed possible application of the film as an alternative to fossil oil

  9. 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.

  10. Personal exposures to airborne metals in London taxi drivers and office workers in 1995 and 1996.

    Science.gov (United States)

    Pfeifer, G D; Harrison, R M; Lynam, D R

    1999-09-01

    In 1995, a petroleum marketer introduced a diesel fuel additive in the UK containing Mn as MMT (methylcyclopentadienyl manganese tricarbonyl). A small study of personal exposures to airborne Mn in London was conducted before and after introduction of the additive to identify any major impact of the additive on exposures. In 1995, personal exposures to Mn were measured in two groups, taxi drivers and office workers (10 subjects per group) for two consecutive 7-day periods. A similar study was carried out in 1996 to determine if exposures had changed. Samples were also analyzed for Ca, Al, Mg and Pb. In 1996, exposures to aerosol mass as total suspended particulates (TSP) and PM2.5 were measured in addition to the metals. Manganese exposures in this cohort did not increase as a result of introduction of the additive. However, a significant source of Mn exposure was discovered during the conduct of these tests. The mean exposure to Mn was higher among the office workers in both years than that of the taxi drivers. This was due to the fact that approximately half of the office workers commuted via the underground railway system where airborne dust and metal concentrations are significantly elevated over those in the general environment. Similar results have been noted in other cities having underground rail systems. Exposure to Mn, Pb, Ca, and Mg were not significantly different between the 2 years. Taxi drivers had higher exposures than office workers to Mg and Pb in both years. Commuting via the underground also had a significant impact on exposures to TSP, PM2.5, Al, and Ca, but had little effect on exposures to Mg. The aerosol in the underground was particularly enriched in Mn, approximately 10-fold, when compared to the aerosol in the general environment. There are several possible sources for this Mn, including mechanical wear of the steel wheels on the steel rais, vaporization of metal from sparking of the third rail, or brake wear.

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yuyang; Chen Xianqiong; Xin, J H [Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hong Kong (China)], E-mail: liuxx751@umn.edu

    2008-12-01

    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.

  12. 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.

  13. 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)

  14. Factors associated with drug use among male motorbike taxi drivers in urban Vietnam.

    Science.gov (United States)

    Nguyen, Huy Van; Vu, Thinh Toan; Pham, Ha Nguyen

    2014-08-01

    A cross-sectional study was conducted on a sample of 291 male motorbike taxi drivers (MMTDs) recruited through social mapping technique in Hanoi, Vietnam, for face-to-face interviews to examine factors associated with drug use among MMTDs using Information-Motivation-Behavioral skills (IMB) model. Among 291 MMTDs, 17.18% reported drug use sometime in their lives, 96% of whom were drug injectors. Being depressed, being originally borne in urban cities, currently residing in rural areas, having a longer time living apart from their wives/lovers, using alcohol, following Buddhism, and reporting lower motivation of HIV prevention predict significantly higher odds of uptaking drugs.

  15. An Electric taxi fleet charging system using second life electric car batteries simulation and economical approach

    OpenAIRE

    Canals Casals, Lluc; Amante García, Beatriz

    2013-01-01

    The industrial car manufacturers see in the high battery price an im-portant obstacle for an electric vehicle mass selling, thus mass production. There-fore, in order to find some cost relieves and better selling opportunities, they look and push forward to find profitable second battery uses. This study presents a sim-ulation and an economical approach for an electric taxi fleet charging system, us-ing these “old” electric car batteries, implemented in the city of Barcelona. The simulation w...

  16. Accesibilidad en el transporte público en Valladolid ferrocarril, autobús y taxi

    OpenAIRE

    Díez Peña, Mª Begoña; Herrero Rodríguez, Sonia

    2015-01-01

    El objetivo de este trabajo es conocer la medida en la que se cumple la normativa de accesibilidad al transporte público en la ciudad de Valladolid, en concreto ferrocarril, autobús y taxi, no sólo en el sentido estricto de la normativa sino también desde el punto de vista de la autonomía de una persona con discapacidad física. Departamento de Organización de Empresas y Comercialización e Investigación de Mercados Máster en Logística

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. Pseudomonas putida F1 uses energy taxis to sense hydroxycinnamic acids.

    Science.gov (United States)

    Hughes, Jonathan G; Zhang, Xiangsheng; Parales, Juanito V; Ditty, Jayna L; Parales, Rebecca E

    2017-10-01

    Soil bacteria such as pseudomonads are widely studied due to their diverse metabolic capabilities, particularly the ability to degrade both naturally occurring and xenobiotic aromatic compounds. Chemotaxis, the directed movement of cells in response to chemical gradients, is common in motile soil bacteria and the wide range of chemicals detected often mirrors the metabolic diversity observed. Pseudomonas putida F1 is a soil isolate capable of chemotaxis toward, and degradation of, numerous aromatic compounds. We showed that P. putida F1 is capable of degrading members of a class of naturally occurring aromatic compounds known as hydroxycinnamic acids, which are components of lignin and are ubiquitous in the soil environment. We also demonstrated the ability of P. putida F1 to sense three hydroxycinnamic acids: p-coumaric, caffeic and ferulic acids. The chemotaxis response to hydroxycinnamic acids was induced during growth in the presence of hydroxycinnamic acids and was negatively regulated by HcaR, the repressor of the hydroxycinnamic acid catabolic genes. Chemotaxis to the three hydroxycinnamic acids was dependent on catabolism, as a mutant lacking the gene encoding feruloyl-CoA synthetase (Fcs), which catalyzes the first step in hydroxycinnamic acid degradation, was unable to respond chemotactically toward p-coumaric, caffeic, or ferulic acids. We tested whether an energy taxis mutant could detect hydroxycinnamic acids and determined that hydroxycinnamic acid sensing is mediated by the energy taxis receptor Aer2.

  5. Influence of Tire Characteristics of Interurban Taxis on Exposure Level to Drivers Whole-Body Vibrations

    Directory of Open Access Journals (Sweden)

    Milad Derakhshanjazari

    2016-03-01

    Full Text Available Introduction: Taxi drivers’ exposure to repeat whole-body vibrations can cause back pain and digestive disorders. Since this type of vibration depends on the car components, this study was carried out to determine the influence of tire characteristics on the amount of whole-body vibrations transmitted to the Peugeot 405 taxi drivers. Methods: In this experimental study, vibration characteristics were measured according to the ISO2631-1 with each of the statuses: tubeless tires fixed and fluid in it (normal air or nitrogen and also the fluid in the tires fixed with tubes or tubeless on asphalt-paved road. Other variables including tire pressure, engine speed, road gradient, number of passengers, springs, and shock absorbers were kept constant. Then the effect of changes was analyzed using an appropriate statistical test. Results: After changing nitrogen to normal air and tubeless tires to tube, the average of RMS in Z-axis, eight-hour equivalent acceleration A(8 and crest factor were reduced (P 0.9 m/s2 to caution zone (0.45-0.9 m/s2 with a value of 0.8 m/s2. Conclusions: The amount of vibration transmitted to the whole body is sensitive to existence of tubes and tires inflation so that we can reduce the amount of whole-body vibration to lower than the upper limit of the health risk by changing the characteristics of the tire

  6. Elevated serum liver enzymes and fatty liver changes associated with long driving among taxi drivers.

    Science.gov (United States)

    Lippmann, Steven J; Richardson, David B; Chen, Jiu-Chiuan

    2011-08-01

    Previous studies suggested increased morbidities and mortalities of liver diseases in drivers. To examine whether driving (monthly driving distance; tenure) is associated with elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), or chronic fatty liver (FL) changes, we performed a cross-sectional, secondary analysis of the Taxi Drivers' Health Study (n = 1,355), adjusting for clinical, demographic, and lifestyle factors. Prevalence of elevated ALT, elevated AST, and fatty liver changes were 22.0%, 5.1%, and 9.3%, respectively. Driving distance had a positive association with elevated ALT with a prevalence ratio of 1.35 (95% CI: 0.98, 1.89) comparing the highest versus lowest driving quartile. This association differed by alcohol use, with a corresponding prevalence ratio of 2.08 (95% CI: 1.30, 3.33) among "past/current" drinkers but no association among "never" drinkers. Similar patterns were found for AST, but estimates were less stable. We found a curvilinear response pattern for fatty liver changes; prevalence first increased with years as a taxi driver and then receded in the highest ranges of driving tenure, regardless of the alcohol history. Our results provide evidence that long driving is associated with both short-term and chronic liver insults, although alcohol use appears to modify this putative effect. Copyright © 2011 Wiley-Liss, Inc.

  7. Perception and reality of particulate matter exposure in New York City taxi drivers.

    Science.gov (United States)

    Gany, Francesca; Bari, Sehrish; Prasad, Lakshmi; Leng, Jennifer; Lee, Trevor; Thurston, George D; Gordon, Terry; Acharya, Sudha; Zelikoff, Judith T

    2017-03-01

    Exposure to fine particulate matter (PM 2.5 ) and black carbon (BC) have been linked to negative health risks, but exposure among professional taxi drivers is understudied. This pilot study measured drivers' knowledge, attitudes, and beliefs (KAB) about air pollution compared with direct measures of exposures. Roadside and in-vehicle levels of PM 2.5 and BC were continuously measured over a single shift on each subject, and exposures compared with central site monitoring. One hundred drivers completed an air pollution KAB questionnaire, and seven taxicabs participated in preliminary in-cab air sampling. Taxicab PM 2.5 and BC concentrations were elevated compared with nearby central monitoring. Average PM 2.5 concentrations per 15-min interval were 4-49 μg/m 3 . BC levels were also elevated; reaching>10 μg/m 3 . Fifty-six of the 100 drivers surveyed believed they were more exposed than non-drivers; 81 believed air pollution causes health problems. Air pollution exposures recorded suggest that driver exposures would likely exceed EPA recommendations if experienced for 24 h. Surveys indicated that driver awareness of this was limited. Future studies should focus on reducing exposures and increasing awareness among taxi drivers.

  8. Injuries and absenteeism among motorcycle taxi drivers who are victims of traffic accidents.

    Science.gov (United States)

    Barbosa, Kevan G N; Lucas-Neto, Alfredo; Gama, Bruno D; Lima-Neto, Jose C; Lucas, Rilva Suely C C; d'Ávila, Sérgio

    2014-08-01

    Facial injuries frequently occur in traffic accidents involving motorcycles. The purpose of this study was to determine the prevalence of facial injuries among motorcycle drivers who perform motorcycle taxi service. The study design was cross-sectional. A total of 210 participants who served as motorcycle taxi drivers in a city in northeastern Brazil completed a survey concerning their experience of accidents involving facial injuries and consequent hospitalization and absenteeism from work. The motorcycle drivers included in the study were randomly selected from a list provided by the city. Out of the respondents, 165 (78.6%) who were involved in traffic accidents in the last 12 months, 15 (9.1%) reported facial injuries. The types of facial injury most frequently reported involved soft tissues (n = 8; 53.3%), followed by simple fracture (n = 4; 26.7%) and dentoalveolar fracture (n = 3; 20%). We found an association between facial injuries and absenteeism, as well as an association between the presence of facial injury and the need for hospitalization for a period of 2 days or more. Respondents reported that they had accidents, but due to the use of full face motorcycle helmet the number of facial injuries was low. For most of them, absenteeism was observed for a period of one month or more. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  9. 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.

  10. An investigation into the feasibility and potential benefits of shared taxi services to commuter stations

    Directory of Open Access Journals (Sweden)

    Steve Wright

    2014-01-01

    Full Text Available Parking is a serious problem at many rail stations where large numbers of commuters ‘park and ride’ mainly on a single occupancy basis. In many cases, these stations are not designed for mass parking, resulting in on-street parking conflicts with residents and local commercial businesses. Furthermore, congestion around stations is a growing problem, compounded by rail passengers being picked up by friends or relatives resulting in queues of waiting cars at station entrances. These ‘kiss and ride’ trips require double the fuel (home to station to home again and impinge on the time of the driver providing the lift. In this paper, it is anticipated that the introduction of shared taxis to rail stations has the potential to relieve these parking and congestion problems while also providing an affordable extra service to the rail station for those without access to a car or other suitable public transport service. A model for shared taxi operation is presented and the potential viability and benefits of such a service is illustrated using data from two varied case study sites: (1 a station in South East England providing rail access to London and (2 a smaller station in Central Scotland providing rail access to Edinburgh.

  11. Internal Traits of Eggs and Their Relationship to Shank Feathering in Chicken Using Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Shaker AS

    2017-06-01

    Full Text Available Chicken eggs represent an important source of protein to the growing human population and also supply repositories of unique genes that could be used worldwide. The inheritance of shank feathering trait is dominant upon non-feathering shank trait in chicken which is based on two factors: pti-1L and pti-1B that are located on Chromosomes 13, 15, and 24. Using 185 fertile eggs collected from two genetic lines (shank feathering and non-feathering shank of White Kurdish chicken, we found that egg weight highly (P < 0.01 correlated with yolk weight (r2=0.520, 0.704, respectively, albumen weight (r2=0.918, 0.835, and shell weight (r2=0.626, 0.225. The first two principal components explained the greatest variance in both the White with shank feathering (85.6% of total variance and non-feathering shank (76.5%. Therefore, differences in the component traits of the eggs between the two genetic lines may be influenced by the same gene actions as shank feathering trait. According to these results, the two genetic lines of Kurdish chicken yield significant differences in the internal traits of eggs.

  12. 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.

  13. 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.

  14. Cadmium, lead, and mercury levels in feathers of small passerine birds: noninvasive sampling strategy.

    Science.gov (United States)

    Bianchi, Nicola; Ancora, Stefania; di Fazio, Noemi; Leonzio, Claudio

    2008-10-01

    Bird feathers have been widely used as a nondestructive biological material for monitoring heavy metals. Sources of metals taken up by feathers include diet (metals are incorporated during feather formation), preening, and direct contact with metals in water, air, dust, and plants. In the literature, data regarding the origin of trace elements in feathers are not univocal. Only in the vast literature concerning mercury (as methyl mercury) has endogenous origin been determined. In the present study, we investigate cadmium, lead, and mercury levels in feathers of prey of Falco eleonorae in relation to the ecological characteristics (molt, habitat, and contamination by soil) of the different species. Cluster analysis identified two main groups of species. Differences and correlations within and between groups identified by cluster analysis were then checked by nonparametric statistical analysis. The results showed that mercury levels had a pattern significantly different from those of cadmium and lead, which in turn showed a significant positive correlation, suggesting different origins. Nests of F. eleonorae proved to be a good source for feathers of small trans-Saharan passerines collected by a noninvasive method. They provided abundant feathers of the various species in a relatively small area--in this case, the falcon colony on the Isle of San Pietro, Sardinia, Italy.

  15. The allometric pattern of sexually size dimorphic feather ornaments and factors affecting allometry.

    Science.gov (United States)

    Cuervo, José J; Møller, A P

    2009-07-01

    The static allometry of secondary sexual characters is currently subject to debate. While some studies suggest an almost universal positive allometry for such traits, but isometry or negative allometry for nonornamental traits, other studies maintain that any kind of allometric pattern is possible. Therefore, we investigated the allometry of sexually size dimorphic feather ornaments in 67 species of birds. We also studied the allometry of female feathers homologous to male ornaments (female ornaments in the following) and ordinary nonsexual traits. Allometries were estimated as reduced major axis slopes of trait length on tarsus length. Ornamental feathers showed positive allometric slopes in both sexes, although that was not a peculiarity for ornamental feathers, because nonsexual tail feathers also showed positive allometry. Migration distance (in males) and relative size of the tail ornament (in females) tended to be negatively related to the allometric slope of tail feather ornaments, although these results were not conclusive. Finally, we found an association between mating system and allometry of tail feather ornaments, with species with more intense sexual selection showing a smaller degree of allometry of tail ornaments. This study is consistent with theoretical models that predict no specific kind of allometric pattern for sexual and nonsexual characters.

  16. Feathers as a Tool to Assess Mercury Contamination in Gentoo Penguins: Variations at the Individual Level.

    Science.gov (United States)

    Pedro, Sara; Xavier, José C; Tavares, Sílvia; Trathan, Phil N; Ratcliffe, Norman; Paiva, Vitor H; Medeiros, Renata; Pereira, Eduarda; Pardal, Miguel A

    2015-01-01

    Feathers have been widely used to assess mercury contamination in birds as they reflect metal concentrations accumulated between successive moult periods: they are also easy to sample and have minimum impact on the study birds. Moult is considered the major pathway for mercury excretion in seabirds. Penguins are widely believed to undergo a complete, annual moult during which they do not feed. As penguins lose all their feathers, they are expected to have a low individual-variability in feather mercury concentration as all feathers are formed simultaneously from the same somatic reserves. This assumption is central to penguin studies that use feathers to examine the annual or among-individual variation in mercury concentrations in penguins. To test this assumption, we measured the mercury concentrations in 3-5 body feathers of 52 gentoo penguins (Pygoscelis papua) breeding at Bird Island, South Georgia (54°S 38°W). Twenty-five percent of the penguins studied showed substantial within-individual variation in the amount of mercury in their feathers (Coefficient of Variation: 34.7-96.7%). This variation may be caused by differences in moult patterns among individuals within the population leading to different interpretations in the overall population. Further investigation is now needed to fully understand individual variation in penguins' moult.

  17. Feathers as a Tool to Assess Mercury Contamination in Gentoo Penguins: Variations at the Individual Level.

    Directory of Open Access Journals (Sweden)

    Sara Pedro

    Full Text Available Feathers have been widely used to assess mercury contamination in birds as they reflect metal concentrations accumulated between successive moult periods: they are also easy to sample and have minimum impact on the study birds. Moult is considered the major pathway for mercury excretion in seabirds. Penguins are widely believed to undergo a complete, annual moult during which they do not feed. As penguins lose all their feathers, they are expected to have a low individual-variability in feather mercury concentration as all feathers are formed simultaneously from the same somatic reserves. This assumption is central to penguin studies that use feathers to examine the annual or among-individual variation in mercury concentrations in penguins. To test this assumption, we measured the mercury concentrations in 3-5 body feathers of 52 gentoo penguins (Pygoscelis papua breeding at Bird Island, South Georgia (54°S 38°W. Twenty-five percent of the penguins studied showed substantial within-individual variation in the amount of mercury in their feathers (Coefficient of Variation: 34.7-96.7%. This variation may be caused by differences in moult patterns among individuals within the population leading to different interpretations in the overall population. Further investigation is now needed to fully understand individual variation in penguins' moult.

  18. Conceptual Study of Rotary-Wing Microrobotics

    National Research Council Canada - National Science Library

    Chabak, Kelson D

    2008-01-01

    This thesis presents a novel rotary-wing micro-electro-mechanical systems (MEMS) robot design. Two MEMS wing designs were designed, fabricated and tested including one that possesses features conducive to insect level aerodynamics...

  19. Aerodynamic control with passively pitching wings

    Science.gov (United States)

    Gravish, Nick; Wood, Robert

    Flapping wings may pitch passively under aerodynamic and inertial loads. Such passive pitching is observed in flapping wing insect and robot flight. The effect of passive wing pitch on the control dynamics of flapping wing flight are unexplored. Here we demonstrate in simulation and experiment the critical role wing pitching plays in yaw control of a flapping wing robot. We study yaw torque generation by a flapping wing allowed to passively rotate in the pitch axis through a rotational spring. Yaw torque is generated through alternating fast and slow upstroke and and downstroke. Yaw torque sensitively depends on both the rotational spring force law and spring stiffness, and at a critical spring stiffness a bifurcation in the yaw torque control relationship occurs. Simulation and experiment reveal the dynamics of this bifurcation and demonstrate that anomalous yaw torque from passively pitching wings is the result of aerodynamic and inertial coupling between the pitching and stroke-plane dynamics.

  20. 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

  1. Discrepancy analysis of driving performance of taxi drivers and non-professional drivers for red-light running violation and crash avoidance at intersections.

    Science.gov (United States)

    Wu, Jiawei; Yan, Xuedong; Radwan, Essam

    2016-06-01

    Due to comfort, convenience, and flexibility, taxis have become increasingly more prevalent in China, especially in large cities. However, many violations and road crashes that occurred frequently were related to taxi drivers. This study aimed to investigate differences in driving performance between taxi drivers and non-professional drivers from the perspectives of red-light running violation and potential crash involvement based on a driving simulation experiment. Two typical scenarios were established in a driving simulator, which includes the red-light running violation scenario and the crash avoidance scenario. There were 49 participants, including 23 taxi drivers (14 males and 9 females) and 26 non-professional drivers (13 males and 13 females) recruited for this experiment. The driving simulation experiment results indicated that non-professional drivers paid more attention to red-light running violations in comparison to taxi drivers who had a higher probability of red-light running violation. Furthermore, it was found that taxi drivers were more inclined to turn the steering wheel in an attempt to avoid a potential collision and non-professional drivers had more abrupt deceleration behaviors when facing a potential crash. Moreover, the experiment results showed that taxi drivers had a smaller crash rate compared to non-professional drivers and had a better performance in terms of crash avoidance at the intersection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 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.

  3. Waving Wing Aerodynamics at Low Reynolds Numbers

    Science.gov (United States)

    2010-07-01

    wing. An attached leading edge vortex has been observed by multiple research groups on both mechanical wing flappers (8; 22; 21; 4) and revolving wing...observed by Ellington et al. (8) in their earlier experiments on the mechanical hawkmoth flapper at Re ≈ 10,000. In these experiments the spanwise flow...on mechanical wing flappers at similar Reynolds numbers, Re ≈ 1,000 and 1,400 respectively. Both sets of experiments revealed a stable attached

  4. 41 CFR 301-10.420 - When may I use a taxi, shuttle service or other courtesy transportation?

    Science.gov (United States)

    2010-07-01

    ..., shuttle service or other courtesy transportation? 301-10.420 Section 301-10.420 Public Contracts and... Courtesy Transportation § 301-10.420 When may I use a taxi, shuttle service or other courtesy... other courtesy transportation (if charges result), in the following manner: (1) At your official station...

  5. “Sharing economy” versus “informal sector”: Jakarta’s motorbike taxi industry in turmoil

    Directory of Open Access Journals (Sweden)

    Mechthild von Vacano

    2017-12-01

    Full Text Available Comparing conventional motor bike taxi services in Jakarta (ojek to their recent online-based competitors (GoJek, this paper contrasts a prime example of the classic “informal sector” with newly emerging forms of the “sharing economy”. It challenges the notion of “informal economy” as an umbrella concept for such two different business models.

  6. 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.

  7. 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...

  8. Wing area, wing growth and wing loading of common sandpipers Actitis hypoleucos

    OpenAIRE

    Yalden, Derek; Yalden, D. W.

    2012-01-01

    This study investigates the changes in wing length, area and loading in Common Sandpipers as chicks grow, and as adults add extra mass (during egg-laying or before migration). Common Sandpiper chicks weigh about 17 g and have "hands" that are about 35 mm long at one week old, when the primaries are just emerging from their sheaths. They grow steadily to reach about 40 g, with hands about 85 mm long, at 19 days, when they are just about fledging. Their wings have roughly adult chord width at t...

  9. How Do Wings Generate Lift?

    Indian Academy of Sciences (India)

    Newton's second law of motion. Hence if a wing can generate lift equal to its weight (total weight of the vehicle) it can balance the gravitational pull and can maintain level flight. The equations for fluid flow that are equivalent to the second law are the well- known Navier–Stokes (N–S) equations [1]. These equations have.

  10. Werner helicase wings DNA binding

    OpenAIRE

    Hoadley, Kelly A.; Keck, James L.

    2010-01-01

    In this issue of Structure, Kitano et al. describe the structure of the DNA-bound winged-helix domain from the Werner helicase. This structure of a RecQ/DNA complex offers insights into the DNA unwinding mechanisms of RecQ family helicases.

  11. On Wings: Aerodynamics of Eagles.

    Science.gov (United States)

    Millson, David

    2000-01-01

    The Aerodynamics Wing Curriculum is a high school program that combines basic physics, aerodynamics, pre-engineering, 3D visualization, computer-assisted drafting, computer-assisted manufacturing, production, reengineering, and success in a 15-hour, 3-week classroom module. (JOW)

  12. Structural Color of Rock Dove’s Neck Feather

    Science.gov (United States)

    Nakamura, Eri; Yoshioka, Shinya; Kinoshita, Shuichi

    2008-12-01

    It is well known that some kinds of animal have surprisingly brilliant colors showing beautiful iridescence. These colors are called structural colors, and are thought to originate from optical interference caused by periodic microstructures that have sizes comparable with the wavelength of light. However, much larger structural modifications can also play an important role in the coloration mechanism. In this paper, we show through careful optical and structural investigations that the structural color of the neck feather of rock dove, Columba livia, has a very comprehensive mechanism: the thin-layer optical interference phenomenon fundamentally produces the iridescence, while the layer structure is accompanied by various kinds of larger-size structural modifications that control the angular range of the reflection. Further, it is found that the granules containing melanin pigment exist in a localized manner to effectively enhance the contrast of the color caused by optical interference.

  13. 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.

  14. New occurrences of fossilized feathers: systematics and taphonomy of the Santana Formation of the Araripe Basin (Cretaceous, NE, Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo M.E.M. Prado

    2016-07-01

    Full Text Available Here we describe three fossil feathers from the Early Cretaceous Santana Formation of the Araripe Basin, Brazil. Feathers are the most complex multiform vertebrate integuments; they perform different functions, occurring in both avian and non-avian dinosaurs. Despite their rarity, fossil feathers have been found across the world. Most of the Brazilian feather fossil record comes from the Santana Formation. This formation is composed of two members: Crato (lake and Romualdo (lagoon; both of which are predominantly reduced deposits, precluding bottom dwelling organisms, resulting in exceptional preservation of the fossils. Despite arid and hot conditions during the Cretaceous, life teemed in the adjacency of this paleolake. Feathered non-avian dinosaurs have not yet been described from the Crato Member, even though there are suggestions of their presence in nearby basins. Our description of the three feathers from the Crato laminated limestone reveals that, despite the small sample size, they can be referred to coelurosaurian theropods. Moreover, based on comparisons with extant feather morphotypes they can be identified as one contour feather and two downy feathers. Despite their rareness and low taxonomic potential, fossilized feathers can offer insights about the paleobiology of its owners and the paleoecology of the Araripe Basin.

  15. The use of feathers of birds of prey as indicators of metal pollution.

    Science.gov (United States)

    Lodenius, Martin; Solonen, Tapio

    2013-11-01

    Published results concerning metal levels in feathers of birds of prey were listed and evaluated. Mercury concentrations have been studied most and the background values normally vary between 0.1 and 5 mg/kg dry weight the highest concentrations being in birds from aquatic food chains. Pollution causes elevated levels of mercury in feathers. The concentrations of cadmium, copper, lead and zinc show reasonable variation between species, areas and time periods. Feathers of birds of prey have proved to be good indicators of the status of environmental heavy metal pollution. Special attention should be paid to clean sampling and preparation of samples. Interpretation of the results requires knowledge on food habit, molting and migration patterns of the species. Several species representing different food chains should be included in comprehensive monitoring surveys. Chick feathers reflect most reliably local conditions.

  16. Drm/Gremlin, a BMP antagonist, defines the interbud region during feather development.

    Science.gov (United States)

    Bardot, Boris; Lecoin, Laure; Fliniaux, Ingrid; Huillard, Emmanuelle; Marx, Maria; Viallet, Jean P

    2004-01-01

    The pattern of feather buds in a tract is thought to result from the relative ratios between activator and inhibitor signals through a lateral inhibition process. We analyse the role of Drm/Gremlin, a BMPs antagonist expressed during feather pattern formation, in the dermal precursor, the dense dermis, the interbud dermis and in the posterior dermal condensation. We have altered the activity of Drm in embryonic chick skin using retroviral vectors expressing drm/ gremlin and bmps. We show that expression of endogenous drm is under the control of a feedback loop induced by the BMP pathway, and that overexpression of drm results in fusion between adjacent feather buds. We propose that endogenous BMP proteins induce drm expression in the interbud dermis. In turn, the Drm/Gremlin protein limits the inhibitory effect of BMPs, allowing the adjacent row of feathers to form. Thus, the balance between BMPs and its antagonist Drm would regulate the size and spacing of the buds.

  17. 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.

  18. Demand pattern analysis of taxi trip data for anomalies detection and explanation

    DEFF Research Database (Denmark)

    Markou, Ioulia; Rodrigues, Filipe; Pereira, Francisco Camara

    2017-01-01

    Due to environmental and economic stress, strong investment exists now towards adaptive transport systems that can efficiently utilize capacity, minimizing costs and environmental impacts. The common vision is a system that dynamically changes itself (the supply) to anticipate traveler needs (the...... demand). In some occasions, unexpected and unwanted demand patterns are noticed in the traffic network that lead to system failures and cost implications. Significantly low speeds or excessively low flows at an unforeseeable time are only some of the phenomena that are often noticed and need...... congestion is happening as well as why there are demand fluctuations in days were there are no apparent reasons for the occurrence of such phenomena. We evaluated our system using Google’s NYC taxi trips public dataset. We defined initially the “normality” baseline and thereunder we studied individual days...

  19. Knee Pain and Driving Duration: A Secondary Analysis of the Taxi Drivers’ Health Study

    Science.gov (United States)

    Chen, Jiu-Chiaun; Dennerlein, Jack T.; Shih, Tung-Sheng; Chen, Chiou-Jong; Cheng, Yawen; Chang, Wushou P.; Ryan, Louise M.; Christiani, David C.

    2004-01-01

    Objectives. We explored a postulated association between daily driving time and knee pain. Methods. We used data from the Taxi Drivers’ Health Study to estimate 1-year prevalence of knee pain as assessed by the Nordic musculoskeletal questionnaire. Results. Among 1242 drivers, the prevalence of knee pain, stratified by duration of daily driving (≤ 6, > 6 through 8, > 8 through 10, and > 10 hours), was 11%, 17%, 19%, and 22%, respectively. Compared with driving 6 or fewer hours per day, the odds ratio of knee pain prevalence for driving more than 6 hours per day was 2.52 (95% confidence interval = 1.36, 4.65) after we adjusted for socioeconomic, work-related, and personal factors in the multiple logistic regression. Conclusions. The dose-related association between driving duration and knee pain raises concerns about work-related knee joint disorders among professional drivers. PMID:15054008

  20. 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...

  1. Per- and polyfluoroalkyl substances in plasma and feathers of nestling birds of prey from northern Norway.

    Science.gov (United States)

    Gómez-Ramírez, P; Bustnes, J O; Eulaers, I; Herzke, D; Johnsen, T V; Lepoint, G; Pérez-García, J M; García-Fernández, A J; Jaspers, V L B

    2017-10-01

    Plasma samples from nestlings of two top predators, White-tailed eagle (Haliaeetus albicilla) and Northern goshawk (Accipiter gentilis) from northern Norway were analysed for a wide range of per- and polyfluoroalkyl substances (PFASs). Body feathers from the White-tailed eagles were also analysed and significant associations between specific PFASs in blood plasma and body feathers were found (0.36 birds of prey are not established. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. 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...

  3. 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

  4. 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

    Feather pecking (FP) is a major welfare problem in laying hens, influenced by multiple factors. FP is thought to be redirected foraging behaviour, however fearful birds are also known to be more sensitive to develop FP. The relationship between fear-responses, foraging and FP is not well understo...... preference for eating feathers, this study supports earlier findings that HFP birds have a stronger pecking motivation than LFP birds...

  5. Sociodemographic factors associated with aggressive driving behaviors of 3-wheeler taxi drivers in Sri Lanka.

    Science.gov (United States)

    Akalanka, Ediriweera Chintana; Fujiwara, Takeo; Desapriya, Ediriweera; Peiris, Dinithi C; Scime, Giulia

    2012-01-01

    Little is known about the nature and scope of aggressive driving in developing countries. The objective of this study is to specifically examine the sociodemographic factors associated with aggressive driving behavior among 3-wheeler taxi drivers in Sri Lanka. Convenience samples of 3-wheeler taxi drivers from Rathnapura, Ahaliyagoda, Sri Lanka were surveyed from June to August 2006. Analyses included bivariate and multivariate logistic regression. Drivers with less than high school education were 3.5 times more likely to drive aggressively (odds ratio [OR] = 3.46; 95% confidence interval [CI] = 1.08, 11.1). Single drivers were 9 times more likely to run red lights (OR = 8.74; 95% CI = 2.18, 35.0), and being single was a major risk factor for drunk driving (OR = 4.80; 95% CI = 1.23, 18.7). Furthermore, high school completers were 4 times more likely to bribe a policeman (OR = 4.27; 95% CI = 1.23, 14.9) when caught violating the road rules. Aggressive driving and risk-taking behavior are amenable to policy initiatives, and preventive programs targeted at key groups could be used to improve road safety in Sri Lanka. This study demonstrates that aggressive driving behavior is associated with sociodemographic factors, including the level of education, marital status, and other socioeconomic factors. Hence, economic factors should be addressed to find solutions to traffic-related issues. It will be the government's and policy makers' responsibility to try and understand the economic factors behind risky road behavior and bribe-taking behavior prior to legislating or enforcing new laws.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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.

  9. Selection of tawny owl (Strix aluco) flight feather shaft for biomonitoring As, Cd and Pb pollution.

    Science.gov (United States)

    Seoane, Rita García; Río, Zulema Varela; Ocaña, Alejo Carballeira; Escribano, José Ángel Fernández; Viñas, Jesús Ramón Aboal

    2018-04-07

    In this study, we determined the concentrations of As, Cd and Pb in the shaft of all primary flight feathers from ten tawny owl (Strix aluco) specimens, with the aim of selecting which shaft of the corresponding primary feather should be used in biomonitoring surveys to enable inter-individual comparisons of the levels of these metals. The birds had died between 2006 and 2013 and their bodies were stored in the various Wildlife Recovery Centres in Galicia (NW Spain). The analyses revealed a high degree of inter-shaft variability, mainly in the concentrations of As and Cd. However, it was possible to identify the most representative samples in each case: for As, the shaft of primary flight feather number 5 (S5) (which represented 11% of the total As excreted in all of the primary flight feathers); for Cd, the shaft of primary flight feather number 2 (S2) (11% of the total excreted); and for Pb, the shaft of primary flight feather number 8 (S8) (14% of the total excreted). However, the difficulties associated with the analytical determination of these pollutants in the shaft should be taken into account when this technique is applied in biomonitoring studies.

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

    Science.gov (United States)

    Rodrigues, Pedro; Mironov, Sergey; Sychra, Oldrich; Resendes, Roberto; Literak, Ivan

    2015-01-01

    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. © P. Rodrigues et al., published by EDP Sciences, 2015.

  11. Environmental-induced acquisition of nuptial plumage expression: a role of denaturation of feather carotenoproteins?

    Science.gov (United States)

    Blanco, Guillermo; Frías, Oscar; Garrido-Fernández, Juan; Hornero-Méndez, Dámaso

    2005-01-01

    Several avian species show a bright carotenoid-based coloration during spring and following a period of duller coloration during the previous winter, despite carotenoids presumably being fully deposited in feathers during the autumn moult. Carotenoid-based breast feathers of male linnets (Carduelis cannabina) increased in hue (redness), saturation and brightness after exposing them to outdoor conditions from winter to spring. This represents the first experimental evidence showing that carotenoid-based plumage coloration may increase towards a colourful expression due to biotic or abiotic environmental factors acting directly on full-grown feathers when carotenoids may be fully functional. Sunlight ultraviolet (UV) irradiation was hypothesized to denature keratin and other proteins that might protect pigments from degradation by this and other environmental factors, suggesting that sunlight UV irradiation is a major factor in the colour increase from winter to spring. Feather proteins and other binding molecules, if existing in the follicles, may be linked to carotenoids since their deposition into feathers to protect colourful features of associated carotenoids during the non-breeding season when its main signalling function may be relaxed. Progress towards uncovering the significance of concealment and subsequent display of colour expression should consider the potential binding and protecting nature of feather proteins associated with carotenoids. PMID:16191594

  12. Effect of an Educational Program Based on the Health Belief Model to Reduce Cell Phone Usage During Driving in Taxi drivers

    OpenAIRE

    Babak Moeini; Forouzan Rezapur-Shahkolai; Javad Faradmal; Mokhtar Soheylizad

    2014-01-01

    Introduction: Cell phone usage during driving has become a threat to traffic safety. This study aimed to determine the effectiveness of an educational program based on the health belief model to reduce cell phone usage during driving in taxi drivers of Tuyserkan. Materials and Methods: In this quasi-experimental study, 110 taxi drivers younger than 35 years were randomly divided into two experimental and control groups in Tuyserkan, Iran. Data was collected using a questionnaire including...

  13. Taxi driver speeding: Who, when, where and how? A comparative study between Shanghai and New York City.

    Science.gov (United States)

    Huang, Yizhe; Sun, Daniel Jian; Tang, Juanyu

    2018-04-03

    The 3 objectives of this study are to (1) identify the driving style characteristics of taxi drivers in Shanghai and New York City (NYC) using taxi Global Positioning System (GPS) data and make a comparative analysis; (2) explore the influence of different driving style characteristics on the frequency of speeding (who and how?) and (3) explore the influence of driving style characteristics, road attributes, and environmental factors on the speeding rate (when, where, and how?) Methods: This study proposes a driver-road-environment identification (DREI) method to investigate the determinant factors of taxi speeding violations. Driving style characteristics, together with road and environment variables, were obtained based on the GPS data and auxiliary spatiotemporal data in Shanghai and NYC. The daily working hours of taxi drivers in Shanghai (18.6 h) was far more than in NYC (8.5 h). The average occupancy speed of taxi drivers in Shanghai (21.3 km/h) was similar to that of NYC (20.3 km/h). Speeders in both cities had shorter working hours and longer daily driving distance than other taxi drivers, though their daily income was similar. Speeding drivers routinely took long-distance trips (>10 km) and preferred relatively faster routes. Length of segments (1.0-1.5 km) and good traffic condition were associated with high speeding rates, whereas central business district area and secondary road were associated with low speeding rates. Moreover, many speeding violations were identified between 4:00 a.m. and 7:00 a.m. in both Shanghai and NYC and the worst period was between 5:00 a.m. and 6:00 a.m. in both cities. Characteristics of drivers, road attributes, and environment variables should be considered together when studying driver speeding behavior. Findings of this study may assist in stipulating relevant laws and regulations such as stricter offense monitoring in the early morning, long segment supervision, shift rule regulation, and working hour restriction to

  14. Ambulatory heart rate of professional taxi drivers while driving without their typical psychosocial work stressors: a pilot study.

    Science.gov (United States)

    Choi, BongKyoo; Choi, SangJun; Jeong, JeeYeon; Lee, JiWon; Shu, Shi; Yu, Nu; Ko, SangBaek; Zhu, Yifang

    2016-01-01

    Few studies have examined ambulatory cardiovascular physiological parameters of taxi drivers while driving in relation to their occupational hazards. This study aims to investigate and quantify the impact of worksite physical hazards as a whole on ambulatory heart rate of professional taxi drivers while driving without their typical worksite psychosocial stressors. Ambulatory heart rate (HR driving ) of 13 non-smoking male taxi drivers (24 to 67 years old) while driving was continuously assessed on their 6-hour experimental on-road driving in Los Angeles. Percent maximum HR range (PMHR driving ) of the drivers while driving was estimated based on the individual HR driving values and US adult population resting HR (HR rest ) reference data. For analyses, the HR driving and PMHR driving data were split and averaged into 5-min segments. Five physical hazards inside taxi cabs were also monitored while driving. Work stress and work hours on typical work days were self-reported. The means of the ambulatory 5-min HR driving and PMHR driving values of the 13 drivers were 80.5 bpm (11.2 bpm higher than their mean HR rest ) and 10.7 % (range, 5.7 to 19.9 %), respectively. The means were lower than the upper limits of ambulatory HR and PMHR for a sustainable 8-hour work (35 bpm above HR rest and 30 % PMHR), although 15-27 % of the 5-min HR driving and PMHR driving values of one driver were higher than the limits. The levels of the five physical hazards among the drivers were modest: temperature (26.4 ± 3.0 °C), relative humidity (40.7 ± 10.4 %), PM 2.5 (21.5 ± 7.9  μg /m 3 ), CO 2 (1,267.1 ± 580.0 ppm) and noise (69.7 ± 3.0 dBA). The drivers worked, on average, 72 h per week and more than half of them reported that their job were often stressful. The impact of physical worksite hazards alone on ambulatory HR of professional taxi drivers in Los Angeles generally appeared to be minor. Future ambulatory heart rate studies including both

  15. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  16. Aerodynamic effects of flexibility in flapping wings

    Science.gov (United States)

    Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P.

    2010-01-01

    Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re ≈ 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small robotic

  17. Aerodynamic effects of flexibility in flapping wings.

    Science.gov (United States)

    Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P

    2010-03-06

    Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re approximately 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small

  18. 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.

  19. Influence of the applied pressure of processing upon bioactive components of diets made of feathers

    Directory of Open Access Journals (Sweden)

    Kormanjoš Šandor M.

    2013-01-01

    Full Text Available The feathers gained by slaughtering fattening chickens can be processed into protein meal for feeding certain animals, as indicated by its chemical characteristics. However, raw feather proteins (keratin are faintly digestible (cca. 19%, even inert in digestive tract. Digestion of feather proteins could be improved by hydrolysis (alkaline, enzymatic, microbiological or hydrothermal. Practically, hydrothermal processing of raw feathers is mostly applied. The influence of hydrothermal processing under the pressures of 3.0, 3.5 or 4.0 bar on the nutritive value of the resulting meal is presented in this paper. For the hydrolysis of raw feathers, semi continuous procedure was applied. Semi continuous procedure of feathers processing comprise hydrolysis of raw wet feathers followed by partial drying of hydrolyzed mass that has to be done in a hydrolyser with indirect heating. Continuous tubular dryer with recycled air was used during the final process of drying. Protein nitrogen decreased by 3.46% and 4.80% in comparison with total protein nitrogen content in raw feathers under the pressure of 3.0 and 3.5 bar, respectively. The highest applied hydrolysis pressure caused the greatest loss of protein nitrogen up to 9.52%. Hydrothermal hydrolysis under pressure has increased in vitro protein digestibility significantly. Under pressure of 3.0, 3.5 and 4.0 bar digestibility of proteins increasing from 19.01 to 76.39, 81.71 and 87.03%, respectively. Under pressure of 3.0, 3.5 and 4.0 bar cysteine content decreased from 6.44 to 4.17% (loss 35.25%, 3.94 (loss 38.825% and to 3.75% (loss 41.77%, respectively. These decreases are statistically significant. It can be concluded that the hydrolysis carried out under the pressure of 3.5 bar, during the period of 25 minutes, and with the content of water in raw feathers of cca. 61% is the optimal technological process for converting raw feathers into diets for certain animal diets.

  20. 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.

  1. The costae presenting in high-temperature-induced vestigial wings ...

    Indian Academy of Sciences (India)

    Most of the wings have defects in the wing blade and partially formed wing margin, which are the result of autonomous cell death in the ... [Yang D. 2007 The costae presenting in high-temperature-induced vestigial wings of Drosophila: implications for anterior wing margin formation. J. Genet. .... The relevant gene(s) may be.

  2. 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

  3. 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

  4. Use of the renewable wind and photovoltaic sources, for the recharge of a fleet of electric taxis in Havana, Cuba

    International Nuclear Information System (INIS)

    Sánchez Torres, Yamir

    2017-01-01

    Electrification of the transportation sector seems to be one of the alternatives in terms of restriction of pollutant from that sector. However, it is necessary to study the GHG (Green House Gas) emissions from Generation Power Plants (EGPP) because could be more or less the same of that from the vehicles. Furthermore, Centralized GPP supply would result in distribution losses, bigger fuel consumption and more pollution. Thus, EVs development should be considered as a sustainable solution if powered by electricity systems with considerable share of Renewable Energy Sources (RES). In this paper, the study of the recharge of an EV taxi fleet during night, using photovoltaic and wind mills RES in Havana, Cuba, is analyzed. This work is aiming to find a feasible operational synergy between cited intermittent RES electricity generation and EVs taxi fleet recharge. (author)

  5. Role of wing morphing in thrust generation

    Directory of Open Access Journals (Sweden)

    Mehdi Ghommem

    2014-01-01

    Full Text Available In this paper, we investigate the role of morphing on flight dynamics of two birds by simulating the flow over rigid and morphing wings that have the characteristics of two different birds, namely the Giant Petrel and Dove Prion. The simulation of a flapping rigid wing shows that the root of the wing should be placed at a specific angle of attack in order to generate enough lift to balance the weight of the bird. However, in this case the generated thrust is either very small, or even negative, depending on the wing shape. Further, results show that morphing of the wing enables a significant increase in the thrust and propulsive efficiency. This indicates that the birds actually utilize some sort of active wing twisting and bending to produce enough thrust. This study should facilitate better guidance for the design of flapping air vehicles.

  6. 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.

  7. "Where to?" remote memory for spatial relations and landmark identity in former taxi drivers with Alzheimer's disease and encephalitis.

    Science.gov (United States)

    Rosenbaum, R Shayna; Gao, Fuqiang; Richards, Brian; Black, Sandra E; Moscovitch, Morris

    2005-03-01

    Recent research suggests that the hippocampus is not needed for the maintenance and recovery of extensively used environments learned long ago. Instead, a network of neocortical regions differentially supports memory for locationnavigation knowledge and visual appearance of well-known places. In this study, we present a patient, S. B., who was diagnosed with probable Alzheimer's disease long after retiring from his 40 years as a taxi driver in downtown Toronto, a place that he has visited rarely, if ever, in the last decade. His performance was compared to that of two other retired taxi drivers, L. R., who developed encephalitis after retirement, and I. L., who is without neurological illness, and a group of eight healthy control participants who were never taxi drivers but all of whom worked or lived in downtown Toronto until at least 10 years ago. Despite S. B.'s widespread atrophy, which has affected mainly his hippocampus and part of his occipitotemporal cortex, he performed at least as well as all other participants on remote memory tests of spatial location and mental navigation between well-known Toronto landmarks. Unlike the comparison populations, however, he was unable to discriminate between the appearances of landmarks that he had visited frequently in his many years as a taxi driver from unknown buildings. This profound deficit extended to famous world landmarks but not to famous faces and does not appear to be semantic in nature. These findings add further support to the claim that the hippocampus is not necessary for mental navigation of old environments and suggest that expertise is not sufficient to protect against landmark agnosia.

  8. Comparison Of Taxis And Logical Semantic Systems In Indonesian And Malaysian Newspapers About Airasia Qz8501 Accident

    OpenAIRE

    Syahputra, Yudha

    2016-01-01

    This study seeks to describe the comparative portion of taxis and logical semantic systems between Malaysian and Indonesian newspapers’ articles about AirAsia QZ8501 accident. The data are clause complexes in Indonesia naval captain says may have located missing plane tail’s section’s New Straits Times (Text A) and AirAsia tail section located, blackbox still missing’s The Jakarta Post (Text B) articles. This study uses qualitative-descriptive method. As the result, both par...

  9. Compliance and enforcement of a partial smoking ban in Lisbon taxis: an exploratory cross-sectional study

    Directory of Open Access Journals (Sweden)

    Ravara Sofia B

    2013-02-01

    Full Text Available Abstract Background Research evaluating enforcement and compliance with smoking partial bans is rather scarce, especially in countries with relative weak tobacco control policies, such as Portugal. There is also scarce evidence on specific high risk groups such as vehicle workers. In January 2008, Portugal implemented a partial ban, followed by poor enforcement. The purpose of this study was to explore the effectiveness of a partial smoking ban in a pro-smoking environment, specifically transportation by taxi in the city of Lisbon. Ban effectiveness was generally defined by ban awareness and support, compliance and enforcement. Methods Exploratory cross-sectional study; purposive sampling in selected Lisbon streets. Structured interviews were conducted by trained researchers while using taxi services (January 2009-December 2010. Participants: 250 taxi drivers (98.8% participation rate. Chi-square, McNemar, Man Whitney tests and multiple logistic regression were performed. Results Of the participants, 249 were male; median age was 53.0 years; 43.6% were current smokers. Most participants (82.8% approved comprehensive bans; 84.8% reported that clients still asked to smoke in their taxis; 16.8% allowed clients to smoke. Prior to the ban this value was 76.9% (p  Conclusions Despite the strong ban support observed, high smoking prevalence and poor enforcement contribute to low compliance. The findings also suggest low compliance among night-shift and vehicle workers. This study clearly demonstrates that a partial and poorly-enforced ban is vulnerable to breaches, and highlights the need for clear and strong policies.

  10. Sphingomonas taxi, Isolated from Cucurbita pepo, Proves to Be a DDE-Degrading and Plant Growth-Promoting Strain

    Science.gov (United States)

    Eevers, Nele; Van Hamme, Jonathan D.; Bottos, Eric M.; Weyens, Nele

    2015-01-01

    The draft genome of Sphingomonas taxi, a strain of the Sphingomonadaceae isolated from Cucurbita pepo root tissue, is presented. This Gram-negative bacterium shows 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE)-degrading potential and plant growth-promoting capacities. An analysis of its 3.9-Mb draft genome will enhance the understanding of DDE-degradation pathways and phytoremediation applications for DDE-contaminated soils. PMID:25977415

  11. 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.

  12. 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.

  13. [Investigation on physical activity and serum lipid level among male taxi drivers of a city in China].

    Science.gov (United States)

    Liu, F; Zhang, R; Li, T T; Wang, H Y

    2017-12-20

    Objective: To investigate the relationship between physical activity (PA) and serum lipid level among male taxi drivers of a city in china. Methods: A total of 360 male taxi drivers were collected by two-stage random sampling method from september to november in 2016, the questionnaires were used to survey the status of PA and serum total cholesterol (TC) , triglyceride (TG) , low-density lipoprotein cholesterol (LDL-C) , high-density lipoprotein cholesterol (HDL-C) , according to the recommended standards of the intenational consensus group on physical activity measurement (ICGPAM) , the participants were divided into 3 groups: high PA level group, moderate PA level group and low PA level group. Results: The percentages of individuals with high, moderate and low PA levels were 60.7%, 22.1%and 17.2% respectively, the levels of TG, LDL-C had a declining trend along with the PA level increase, and the level of HDL-C had a increasing trend, the difference was statistically significant ( P taxi drivers in this city is relatively low, and high PA can reduce the risk of dyslipidemia.

  14. Impulsivity and risky decision making among taxi drivers in Hong Kong: An event-related potential study.

    Science.gov (United States)

    Cheng, Andy S K; Ting, K H; Liu, Karen P Y; Ba, Yutao

    2016-10-01

    Taxi drivers play an important role in providing safe and professional public transport services. However, they tend to be more involved than other professional driver groups in accidents caused by deliberate recklessness. This study used an event-related potential (ERP) experiment to examine risk-taking behavior arising from impulsivity by comparing the underlying neural processes of taxi drivers with and without traffic offence records in Hong Kong. A sample of 15 traffic offenders and 15 nonoffenders, matched by sociodemographic characteristics, was recruited. The results show that the offender group demonstrated significantly less negative-going (less negative) feedback-related negativity but more positive-going (more positive) feedback-related P300 when than with their nonoffending counterparts. These findings show that taxi drivers with traffic offence records were less sensitive to the consequences of behavior and more attuned to the magnitude of potential reward. In addition, behavioral data revealed that they were more willing to make risky decisions. All these characteristics pertain to impulsive personality traits. Based on these findings, we can conclude that the offenders in this sample were more impulsive than their nonoffending counterparts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Analysis of bat wings for morphing

    Science.gov (United States)

    Leylek, Emily A.; Manzo, Justin E.; Garcia, Ephrahim

    2008-03-01

    The morphing of wings from three different bat species is studied using an extension of the Weissinger method. To understand how camber affects performance factors such as lift and lift to drag ratio, XFOIL is used to study thin (3% thickness to chord ratio) airfoils at a low Reynolds number of 100,000. The maximum camber of 9% yielded the largest lift coefficient, and a mid-range camber of 7% yielded the largest lift to drag ratio. Correlations between bat wing morphology and flight characteristics are covered, and the three bat wing planforms chosen represent various combinations of morphological components and different flight modes. The wings are studied using the extended Weissinger method in an "unmorphed" configuration using a thin, symmetric airfoil across the span of the wing through angles of attack of 0°-15°. The wings are then run in the Weissinger method at angles of attack of -2° to 12° in a "morphed" configuration modeled after bat wings seen in flight, where the camber of the airfoils comprising the wings is varied along the span and a twist distribution along the span is introduced. The morphed wing configurations increase the lift coefficient over 1000% from the unmorphed configuration and increase the lift to drag ratio over 175%. The results of the three different species correlate well with their flight in nature.

  16. Veins improve fracture toughness of insect wings.

    Directory of Open Access Journals (Sweden)

    Jan-Henning Dirks

    Full Text Available During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect's flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material's resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m. However, the cross veins increase the wing's toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm. This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically 'optimal' solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial 'venous' wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

  17. Hydrological response to climate warming: The Upper Feather River Watershed

    Science.gov (United States)

    Huang, Guobiao; Kadir, Tariq; Chung, Francis

    2012-03-01

    SummaryThe hydrological response and sensitivity to climate warming of a snow-dominated watershed, the Upper Feather River Basin (UFRB) in Northern California, were evaluated and quantified using observed changes, detrending, and specified temperature-based sensitivity simulations. The non-stationarity in historical data was detected with trend analysis and the warming trends in historical forcing data were removed by detrending. The physically-based and spatially-distributed Precipitation-Runoff Modeling System (PRMS) model was used to force uniform climate warming (+1 °C to +4 °C) to investigate hydrologic sensitivity to temperature increase. Six Global Climate Models (GCMs) with two IPCC Special Report on Emissions Scenarios (SRES), A2 and B1, were selected to represent a range of climate change projections. These projected changes were then applied to the detrended historical forcing data to simulate climate change effects in a detrended, quasi-stationary setting. The results indicate that: (1) historical annual precipitation and streamflow have no trends, but air temperature and seasonal streamflow have statistically significant trends. (2) By detrending temperature, the strong trends in seasonal streamflow are virtually eliminated. (3) Hydrologic Sensitivity to climate warming includes small changes in annual streamflow and actual evapotranspiration, significant changes in streamflow timing and increased frequency and magnitude in extreme flows. (4) All GCM projections lead to negative impact on water supply.

  18. 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

  19. 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).

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Silva, H M; Hernandes, F A; Pichorim, M

    2015-08-01

    The 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.

  3. Reflectance Spectra of Peacock Feathers and the Turning Angles of Melanin Rods in Barbules.

    Science.gov (United States)

    Okazaki, Toshio

    2018-02-01

    I analyzed the association between the reflectance spectra and melanin rod arrangement in barbules of the eyespot of peacock feathers. The reflectance spectra from the yellow-green feather of the eyespot indicated double peaks of 430 and 540 nm. The maximum reflectance spectrum of the blue feather was 480 nm, and that of the dark blue feather was 420 nm. The reflectance spectra from brown feathers indicated double peaks of 490 and 610 nm. Transmission electron microscopic analysis confirmed that melanin rods were arranged fanwise in the outer layer toward the barbule tips. In addition, using polarized light microscope, I attempted to determine whether the turning angles of melanin rods in the barbules reflected different colors. The turning angle of the polarizing axis of the barbules was supported by that of the melanin rods, observed using transmission electron microscopic images. To compare the turning angle of melanin rods in the respective barbules, I calculated the opening width of the fanwise melanin rods by dividing the width of the barbules by the turning angle of the polarizing axis of barbules and obtained a positive correlation between the reflectance spectra and opening width of the fanwise melanin rods. Moreover, the widely spreading reflection from the barbules may occur because of the fanwise melanin rod arrangement.

  4. Adaptive wing : Investigations of passive wing technologies for loads reduction in the cleansky smart fixed wing aircraft (SFWA) project

    NARCIS (Netherlands)

    Kruger, W.R.; Dillinger, J; De Breuker, R.; Reyes, M.; Haydn, K.

    2016-01-01

    In the work package “Adaptive Wing” in the Clean-Sky “Smart Fixed Wing Aircraft” (SFWA) project, design processes and solutions for aircraft wings have been created, giving optimal response with respect to loads, comfort and performance by the introduction of passive and active concepts. Central

  5. 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.

  6. 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...

  7. Phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata) and White-winged Scoters (Melanitta fusca) on the Pacific coast of North America

    Science.gov (United States)

    Dickson, Rian D.; Esler, Daniel; Hupp, Jerry W.; Anderson, E.M.; Evenson, J.R.; Barrett, J.

    2012-01-01

    By quantifying phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata (L., 1758)) and White-winged Scoters (Melanitta fusca (L., 1758)), we tested whether timing of moult is dictated by temporal optima or constraints. Scoters (n = 3481) were captured during moult in Alaska, British Columbia, and Washington, and remigial emergence dates were determined. We provide evidence for a pre-emergence interval of 7.3 days that occurs after old primaries are shed and before new ones become visible. All age and sex classes of both scoter species exhibited a wide range of emergence dates (Surf Scoters: 26 June to 22 September; White-winged Scoters: 6 July to 21 September) suggestive of a lack of strong temporal optima for remigial moult. For both species, timing of moult was influenced by site, year, age, and sex. Relative to other waterfowl species, scoters have typical remigial growth rates (Surf Scoters: 3.9 mm·day–1; White-winged Scoters: 4.3 mm·day–1) but a long flightless period (34–49 days), in part because their relatively high wing-loading requires a greater proportion of feather regrowth to regain flight. Our data suggest that moulting scoters are not under strong selective pressure to complete moult quickly.

  8. 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

  9. Prevalence of Psittacine Beak and Feather Disease Virus and Avian Polyomavirus in Captivity Psittacines from Costa Rica

    DEFF Research Database (Denmark)

    Dolz, Gaby; Sheleby-Elías, Jessica; Romero-Zuñiga, Juan J.

    2013-01-01

    Psittacine beak and feather disease virus (PBFDV) and avian polyomavirus (APV) are the most common viral diseases in psittacine birds, both affecting feathers and physical appearance of birds. Between 2005 and 2009, a total of 269 samples were collected from birds presented at veterinary clinics...

  10. Metabolism of Chicken Feathers and Concomitant Electricity Generation by Pseudomonas aeruginosa by Employing Microbial Fuel Cell (MFC

    Directory of Open Access Journals (Sweden)

    Venkatesh Chaturvedi

    2014-01-01

    Full Text Available Keratinolytic potential of Pseudomonas aeruginosa strain SDS3 has been evaluated for the metabolism of chicken feathers. Results indicated that strain SDS3 showed complete metabolism of 0.1 and 0.5% (w/v chicken feathers in minimal medium. Feathers were metabolized up to 80% at 1% (w/v concentration. Maximum soluble protein (480.8±17.1 μg/mL and keratinase (15.4±0.25 U/mL were observed in the presence of 1% chicken feathers after five days of incubation. The effect of carbon and nitrogen sources showed that feather degradation was stimulated by complex carbon/nitrogen sources such as starch, malt extract, tryptone, and beef extract and was inhibited by simple carbon and nitrogen sources. Electricity production by employing chicken feathers as a substrate in microbial fuel cell (MFC was evaluated. It was observed that maximum voltage corresponding to 141 mV was observed after 14 days of incubation. Maximum power density of 1206.78 mW/m2 and maximum current density of 8.6 mA/m2 were observed. The results clearly indicate that chicken feathers can be successfully employed as a cheap substrate for electricity production in MFC. This is the first report showing employment of chicken feathers as substrate in MFC.

  11. Comparison of individual and social feather pecking tests in two lines of laying hens at ten different ages

    NARCIS (Netherlands)

    Rodenburg, T.B.; Koene, P.

    2003-01-01

    The aim of this experiment was to select a suitable test to measure feather pecking in laying hens. Pecking behaviour in individual and social feather pecking tests was compared with pecking behaviour in the homepen. Two lines of laying hens were used that differ in their propensity to display

  12. 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

  13. The impact of uropygial gland secretions on mechanically induced wearing of barn owl and pigeon body feathers

    Science.gov (United States)

    Ott, Benjamin; Müsse, Annika; Wagner, Hermann

    2016-04-01

    Bird feathers are remarkable structures light but yet durable providing insulation and the ability of flight. Owls are highly specialized birds of prey, widely known for their ability to y silently which is enabled by (micro-) structural specializations of the feathers. The barn owl replaces feathers less frequently in comparison to other same sized birds like pigeons, indicating a much better resistance against material fatigue of these delicate microstructures. We used axisymmetric drop shape analysis (ADSA) of water drop contact angles as a non-destructive method of characterizing wearing processes in feathers. We hypothesized that feathers become more wettable when worn. We also investigated the impact of ethanol treatment in order to remove fatty residues of the uropygial gland secretions, barn owls and pigeons use for preening, on ageing processes. Ethanol treatment resulted in a slight, but significant increase of water repellency in barn owl but not in pigeon flight feathers. Our preliminary data also suggest that the uropygial gland secretions decelerate the wearing process of the feather keratin. We observed this effect in both species, however, it was more distinct for barn owl uropygial gland secretions. The results of this study, obtained by contact angle measurements used as a non-destructive evaluation method of material fatigue, yield insights into the material fatigue of feathers and the decelerating effect of uropygial gland secretions on wear on the other hand.

  14. 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

  15. 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...

  16. Feather mite abundance varies but symbiotic nature of mite-host relationship does not differ between two ecologically dissimilar warblers

    Science.gov (United States)

    Alix E. Matthews; Jeffery L. Larkin; Douglas W. Raybuck; Morgan C. Slevin; Scott H. Stoleson; Than J. Boves

    2017-01-01

    Feather mites are obligatory ectosymbionts of birds that primarily feed on the oily secretions from the uropygial gland. Feather mite abundance varies within and among host species and has various effects on host condition and fitness, but there is little consensus on factors that drive variation of this symbiotic system. We tested hypotheses regarding how within-...

  17. 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...

  18. Effects of genetic background and social environment on feather pecking and related behavioural characteristics in laying hens

    NARCIS (Netherlands)

    Uitdehaag, K.A.

    2008-01-01

    Woldwide, but especially in Europe, poultry husbandry will undergo significant changes due to the prohibition of
    both battery cage systems and beak-trimming. In laying hens, these changes will increase the risk of feather
    pecking. Feather pecking is defined as the non-aggressive pecking

  19. 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.

  20. 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

  1. The Detection of Transport Land-Use Data Using Crowdsourcing Taxi Trajectory

    Science.gov (United States)

    Ai, T.; Yang, W.

    2016-06-01

    This study tries to explore the question of transport land-use change detection by large volume of vehicle trajectory data, presenting a method based on Deluanay triangulation. The whole method includes three steps. The first one is to pre-process the vehicle trajectory data including the point anomaly removing and the conversion of trajectory point to track line. Secondly, construct Deluanay triangulation within the vehicle trajectory line to detect neighborhood relation. Considering the case that some of the trajectory segments are too long, we use a interpolation measure to add more points for the improved triangulation. Thirdly, extract the transport road by cutting short triangle edge and organizing the polygon topology. We have conducted the experiment of transport land-use change discovery using the data of taxi track in Beijing City. We extract not only the transport land-use area but also the semantic information such as the transformation speed, the traffic jam distribution, the main vehicle movement direction and others. Compared with the existed transport network data, such as OpenStreet Map, our method is proved to be quick and accurate.

  2. THE DETECTION OF TRANSPORT LAND-USE DATA USING CROWDSOURCING TAXI TRAJECTORY

    Directory of Open Access Journals (Sweden)

    T. Ai

    2016-06-01

    Full Text Available This study tries to explore the question of transport land-use change detection by large volume of vehicle trajectory data, presenting a method based on Deluanay triangulation. The whole method includes three steps. The first one is to pre-process the vehicle trajectory data including the point anomaly removing and the conversion of trajectory point to track line. Secondly, construct Deluanay triangulation within the vehicle trajectory line to detect neighborhood relation. Considering the case that some of the trajectory segments are too long, we use a interpolation measure to add more points for the improved triangulation. Thirdly, extract the transport road by cutting short triangle edge and organizing the polygon topology. We have conducted the experiment of transport land-use change discovery using the data of taxi track in Beijing City. We extract not only the transport land-use area but also the semantic information such as the transformation speed, the traffic jam distribution, the main vehicle movement direction and others. Compared with the existed transport network data, such as OpenStreet Map, our method is proved to be quick and accurate.

  3. Taxi driver training in Madagascar: the first step in developing a functioning prehospital emergency care system.

    Science.gov (United States)

    Geduld, Heike; Wallis, Lee

    2011-09-01

    Prehospital care in developing countries is severely lacking. Few countries can afford the relatively expensive formalised Western model of a prehospital emergency medical system. The WHO has highlighted the development of layperson first responder programmes as the most basic step in the development of a functioning prehospital system. To describe the first training programme of its kind, run in Mahajanga, Madagascar. The faculty was invited by Mahajanga Medical School. Local input was taken into account in developing the curriculum. 26 taxi drivers were invited to attend in cooperation with the local municipality. The faculty consisted of five instructors from the Division of Emergency Medicine and EMSSA, plus local doctors from University Hospital Mahajanga. The 1-day course included workshops on prehospital scene management, bleeding and broken bones, immobilisation and patient movement, and labour and delivery. The workshops made use of commonly available items only including packets, string and towels; French and Malagasy translators were available throughout. Both faculty and candidates deemed the course a success and plans for formal evaluation of knowledge and skill retention are underway. Future plans are to continue the training using local instructors and in rural districts.

  4. Autonomous taxis could greatly reduce greenhouse-gas emissions of US light-duty vehicles

    Science.gov (United States)

    Greenblatt, Jeffery B.; Saxena, Samveg

    2015-09-01

    Autonomous vehicles (AVs) are conveyances to move passengers or freight without human intervention. AVs are potentially disruptive both technologically and socially, with claimed benefits including increased safety, road utilization, driver productivity and energy savings. Here we estimate 2014 and 2030 greenhouse-gas (GHG) emissions and costs of autonomous taxis (ATs), a class of fully autonomous shared AVs likely to gain rapid early market share, through three synergistic effects: (1) future decreases in electricity GHG emissions intensity, (2) smaller vehicle sizes resulting from trip-specific AT deployment, and (3) higher annual vehicle-miles travelled (VMT), increasing high-efficiency (especially battery-electric) vehicle cost-effectiveness. Combined, these factors could result in decreased US per-mile GHG emissions in 2030 per AT deployed of 87-94% below current conventionally driven vehicles (CDVs), and 63-82% below projected 2030 hybrid vehicles, without including other energy-saving benefits of AVs. With these substantial GHG savings, ATs could enable GHG reductions even if total VMT, average speed and vehicle size increased substantially. Oil consumption would also be reduced by nearly 100%.

  5. The Realization and Study of Optical Wings

    Science.gov (United States)

    Artusio-Glimpse, Alexandra Brae

    Consider the airfoil: a carefully designed structure capable of stable lift in a uniform air flow. It so happens that air pressure and radiation (light) pressure are similar phenomena because each transfer momentum to flow-disturbing objects. This, then, begs the question: does an optical analogue to the airfoil exist? Though an exceedingly small effect, scientists harness radiation pressure in a wide gamut of applications from micromanipulation of single biological particles to the propulsion of large spacecrafts called solar sails. We introduce a cambered, refractive rod that is subjected to optical forces analogous to those seen in aerodynamics, and I call this analogue the optical wing. Flight characteristics of optical wings are determined by wing shape and material in a uniform radiation field. Theory predicts the lift force and axial torque are functions of the wing's angle of attack with stable and unstable orientations. These structures can operate as intensity-dependent, parametrically driven oscillators. In two-dimensions, the wings exhibit bistability when analyzed in an accelerating frame. In three-dimensions, the motion of axially symmetric spinning hemispherical wings is analogous to a spinning top. Experiments on semi-buoyant wings in water found semicylindrically shaped, refractive microparticles traversed a laser beam and rotated to an illumination-dependent stable orientation. Preliminary tests aid in the development of a calibrated force measurement experiment to directly evaluate the optical forces and torque on these samples. A foundational study of the optical wing, this work contributes to future advancements of flight-by-light.

  6. The Crest Wing Wave Energy Device

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Antonishen, Michael Patrick

    This report presents the results of a continuation of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC), in the following referred to as ‘Phase 2'. The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave...

  7. Veins Improve Fracture Toughness of Insect Wings

    Science.gov (United States)

    Dirks, Jan-Henning; Taylor, David

    2012-01-01

    During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect’s flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material’s resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m). However, the cross veins increase the wing’s toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm). This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically ‘optimal’ solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial ‘venous’ wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species. PMID:22927966

  8. Effect of leading edge roundness on a delta wing in wing-rock motion

    Science.gov (United States)

    Ng, T. Terry; Malcolm, Gerald N.

    1990-01-01

    The effect of wing leading-edge roundness on wing rock was investigated using flow visualization in a water tunnel. Eighty degree delta wing models were tested on free-to-roll and forced oscillation rigs. The onset of wing rock was delayed by increasing the roundness of the leading edges. The wing rock amplitude and frequency results suggested that damping was increased at lower angles of attack but reduced at higher angles of attack. Vortex lift-off and vortex breakdown, especially during dynamic situations, were strongly affected by the leading edge roundness. Different forms of wing rock motion could be sustained by combinations of vortex breakdown and vortex lift-off. Behaviors of the wing and vortex motions were explained by the influence of leading edge roundness on the separation location, vortex trajectory, and vortex breakdown.

  9. Pyrolyzed feather fibers for adsorbent and high temperature applications

    Science.gov (United States)

    Senoz, Erman

    Chicken feather fibers (CFF) are problematic and costly for the poultry industry in terms of managing maintenance and disposal. Considering their great availability, low cost, and unique protein structure, CFF can be an environmentally friendly and bio-renewable candidate to replace petroleum products. CFF's low degradation and melting temperature render them useless at high temperatures. Pyrolysis methods were developed for CFF by using two temperature steps to convert them into high temperature resistant and adsorbent fibers while retaining their original physical appearance and affine dimensions. An intermolecular crosslinking mechanism in the first step of pyrolysis at 215 ºC for 24 h provided an intact fibrous structure with no subsequent melting. The evidence obtained from the thermal, bulk, and surface analysis techniques was indication of the simultaneous side chain degradation, polypeptide backbone scission, disulfide bond cleavage, and isopeptide crosslinking. The variation in the reaction kinetics of disulfide bond cleavage and isopeptide crosslinking played an important role in the melting transition. Consequently, long-lasting heat treatments below the melting point provided sufficient crosslinks in the protein matrix to keep the fibrous structure intact. Water-insoluble and crosslinked CFF reinforced the triglyceride-fatty acid based composites by providing a 15 fold increase in storage and tensile modulus at room temperature. These thermally stable fibers can be used instead of CFF in composites which may require high temperature compounding and molding processes. The second step of pyrolysis at 400--450 ºC for 1 h resulted in microporous fibers with a micropore volume of ˜0.18 cm3/g STP and with a narrower pore size distribution than commercial activated carbons through thermal degradation. Nearly all accessible pores in the microporous pyrolyzed chicken feather fibers (PCFF) had diameters less than 1 nm and therefore, showed a potential to be

  10. Biodegradability of injection molded bioplastic pots containing polylactic acid and poultry feather fiber.

    Science.gov (United States)

    Ahn, H K; Huda, M S; Smith, M C; Mulbry, W; Schmidt, W F; Reeves, J B

    2011-04-01

    The biodegradability of three types of bioplastic pots was evaluated by measuring carbon dioxide produced from lab-scale compost reactors containing mixtures of pot fragments and compost inoculum held at 58 °C for 60 days. Biodegradability of pot type A (composed of 100% polylactic acid (PLA)) was very low (13 ± 3%) compared to literature values for other PLA materials. Near infrared spectroscopy (NIRS) results suggest that the PLA undergoes chemical structural changes during polymer extrusion and injection molding. These changes may be the basis of the low biodegradability value. Biodegradability of pot types B (containing 5% poultry feather, 80% PLA, 15% starch), and C (containing 50% poultry feather, 25% urea, 25% glycerol), were 53 ± 2% and 39 ± 3%, respectively. More than 85% of the total biodegradation of these bioplastics occurred within 38 days. NIRS results revealed that poultry feather was not degraded during composting. Published by Elsevier Ltd.

  11. 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.

  12. 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

  13. Feather microstructure of the black-billed magpie (Pica pica sericea) and jungle crow (Corvus macrorhynchos).

    Science.gov (United States)

    Lee, Eunok; Lee, Hang; Kimura, Junpei; Sugita, Shoei

    2010-08-01

    The jungle crow (Corvus macrorhynchos) distribution stretches from eastern Eurasia continent to southeastern Asia. The distribution of the black-billed magpie (Pica pica sericea) stretches from Korea and China to the Kyushu area in Japan. They are both in the Family, Corvidae, and have iridescent feather colors, but the iridescent feather color of the black-billed magpie is more remarkable than that of the jungle crow. We observed the feather microstructure of these birds using electron microscope. On the barbules surface, the barbules twist and prong between the jungle crow and black-billed magpie were not similar. In the barbules cross section, the black-billed magpie showed a complex structure of melanin granules, the jungle crow showed a simple structure of melanin granules.

  14. A continued role for signaling functions in the early evolution of feathers.

    Science.gov (United States)

    Ruxton, Graeme D; Persons Iv, W Scott; Currie, Philip J

    2017-03-01

    Persons and Currie (2015) argued against either flight, thermoregulation, or signaling as a functional benefit driving the earliest evolution of feathers; rather, they favored simple feathers having an initial tactile sensory function, which changed to a thermoregulatory function as density increased. Here, we explore the relative merits of early simple feathers that may have originated as tactile sensors progressing instead toward a signaling, rather than (or in addition to) a thermoregulatory function. We suggest that signaling could act in concert with a sensory function more naturally than could thermoregulation. As such, the dismissal of a possible signaling function and the presumption that an initial sensory function led directly to a thermoregulatory function (implicit in the title "bristles before down") are premature. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  15. 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.

  16. 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.

  17. Structural color change following hydration and dehydration of iridescent mourning dove (Zenaida macroura) feathers.

    Science.gov (United States)

    Shawkey, Matthew D; D'Alba, Liliana; Wozny, Joel; Eliason, Chad; Koop, Jennifer A H; Jia, Li

    2011-04-01

    Dynamic changes in integumentary color occur in cases as diverse as the neurologically controlled iridiphores of cephalopod skin and the humidity-responsive cuticles of longhorn beetles. By contrast, feather colors are generally assumed to be relatively static, changing by small amounts only over periods of months. However, this assumption has rarely been tested even though structural colors of feathers are produced by ordered nanostructures that are analogous to those in the aforementioned dynamic systems. Feathers are neither innervated nor vascularized and therefore any color change must be caused by external stimuli. Thus, we here explore how feathers of iridescent mourning doves Zenaida macroura respond to a simple stimulus: addition and evaporation of water. After three rounds of experimental wetting and subsequent evaporation, iridescent feather color changed hue, became more chromatic and increased in overall reflectance by almost 50%. To understand the mechanistic basis of this change, we used electron microscopy to examine macro- and nanostructures before and after treatment. Transmission electron microscopy and transfer matrix thin-film models revealed that color is produced by thin-film interference from a single (∼ 35 nm layer of keratin around the edge of feather barbules, beneath which lies a layer of air and melanosomes. After treatment, the most striking morphological difference was a twisting of colored barbules that exposed more of their surface area for reflection, explaining the observed increase in brightness. These results suggest that some plumage colors may be more malleable than previously thought, leading to new avenues for research on dynamic plumage color. Published by Elsevier GmbH.

  18. 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

  19. Effects of immune activation and glucocorticoid administration on feather growth in greenfinches.

    Science.gov (United States)

    Männiste, Marju; Hõrak, Peeter

    2011-11-01

    Elevation of glucocorticoid (GC) hormone levels is an integral part of stress response (as well as its termination) and immunomodulation. These hormones are also responsible for mobilizing energy stores by stimulation of gluconeogenesis and inhibition of protein synthesis. Elevation of GCs is thus incompatible with other protein-demanding processes, such as moult. Previous studies have shown that chronic elevation of GC hormones suppresses feather growth. Here, we asked whether similar effect would also occur in the case of acute GC elevation and induction of an inflammatory response by foreign antigen. We performed an experiment on captive wild-caught greenfinches (Carduelis chloris) injecting birds with phytohaemagglutinin (PHA) and dexamethasone (DEX) in a factorial design. To assess the possible somatic impacts of these manipulations, we removed one of the outermost tail feathers before the experiment and measured mass and rachis diameter and length of the replacement feathers grown in captivity. Immunostimulation by PHA reduced rachis length, but did not affect feather mass or rachis diameter. Single injection of a synthetic GC hormone DEX significantly reduced all three parameters of feather size. Altogether, these findings demonstrate the sensitivity of feather growth to manipulation of immune and adrenal functions. Our results corroborate the somatic costs of immune activation and suggest that even a short-term elevation of GC hormones may induce long-term somatic costs with a potential impact on fitness. Our findings also imply that a single injection of DEX, frequently used as a diagnostic tool, can have lasting effects and researchers must consider this when designing experiments. © 2011 Wiley Periodicals, Inc.

  20. [Fracture toughness of zirconia ceramic crowns made by feather-edge tooth preparation design].

    Science.gov (United States)

    Mirković, Nemanja; Gostović, Aleksandra Spadijer; Lazić, Zoran; Trifković, Branka

    2012-07-01

    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. 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 mmn 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. 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 2000 N, what was double beyond a recommended value. The mean value of fracture toughness in the feather-edge group was 2090 N, and in shoulder group it was 2214 N. 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 gingival inflammatory response.