WorldWideScience

Sample records for extinct passenger pigeon

  1. Drastic population fluctuations explain the rapid extinction of the passenger pigeon.

    Science.gov (United States)

    Hung, Chih-Ming; Shaner, Pei-Jen L; Zink, Robert M; Liu, Wei-Chung; Chu, Te-Chin; Huang, Wen-San; Li, Shou-Hsien

    2014-07-22

    To assess the role of human disturbances in species' extinction requires an understanding of the species population history before human impact. The passenger pigeon was once the most abundant bird in the world, with a population size estimated at 3-5 billion in the 1800s; its abrupt extinction in 1914 raises the question of how such an abundant bird could have been driven to extinction in mere decades. Although human exploitation is often blamed, the role of natural population dynamics in the passenger pigeon's extinction remains unexplored. Applying high-throughput sequencing technologies to obtain sequences from most of the genome, we calculated that the passenger pigeon's effective population size throughout the last million years was persistently about 1/10,000 of the 1800's estimated number of individuals, a ratio 1,000-times lower than typically found. This result suggests that the passenger pigeon was not always super abundant but experienced dramatic population fluctuations, resembling those of an "outbreak" species. Ecological niche models supported inference of drastic changes in the extent of its breeding range over the last glacial-interglacial cycle. An estimate of acorn-based carrying capacity during the past 21,000 y showed great year-to-year variations. Based on our results, we hypothesize that ecological conditions that dramatically reduced population size under natural conditions could have interacted with human exploitation in causing the passenger pigeon's rapid demise. Our study illustrates that even species as abundant as the passenger pigeon can be vulnerable to human threats if they are subject to dramatic population fluctuations, and provides a new perspective on the greatest human-caused extinction in recorded history.

  2. Experimental Investigation of the Dietary Ecology of the Extinct Passenger Pigeon, Ectopistes migratorius

    Directory of Open Access Journals (Sweden)

    Ben J. Novak

    2018-03-01

    Full Text Available For tens of thousands of years, passenger pigeons (Ectopistes migratorius were a dominant member of eastern North American forest communities, with megaflocks comprising up to several billion individuals. The extinction of passenger pigeons in the early twentieth century undoubtedly influenced associated species and ecosystems as interactions stemming from the pigeons disappeared suddenly. Here, we strive to better understand what was probably one of the most significant of these interactions—that between passenger pigeons and seed bearing trees. Using the band-tailed pigeon (Patagioenas fasciata and the rock dove (Columba livia as physical and ecological proxies, we evaluated passenger pigeon dietary range and potential to disperse seeds. Our findings suggest that the passenger pigeon's dietary range, observed historically to be taxonomically broad, was constrained to certain seed sizes due to bill gape size. In addition, we conclude that the digestive process invariably destroyed consumed seeds but the potential for a nutrition/dispersal mutualism might still have existed via regurgitation and post-mortem release of crop contents. Our results highlight the range of ecological interactions that can be lost with species' extinction and the inherent challenge of understanding the consequences of those interactions.

  3. The flight of the Passenger Pigeon: phylogenetics and biogeographic history of an extinct species.

    Science.gov (United States)

    Johnson, Kevin P; Clayton, Dale H; Dumbacher, John P; Fleischer, Robert C

    2010-10-01

    The human-caused extinction of the Passenger Pigeon (Ectopistes migratorius) is one of the best known and documented of any bird. This event was particularly alarming because the Passenger Pigeon went from being one of the most numerous avian species in the world to extinct in a period of decades, when the last individual died in captivity in a Cincinnati Zoo in 1914. While a great deal of information exists on the likely direct and indirect causes of its demise, as well as information on life-history, the phylogenetic relationships of this species have been subject to considerable speculation. Here we use DNA sequences obtained from museum specimens to resolve the phylogenetic position of this species with respect to other pigeons and doves (Columbiformes). We show that the Passenger Pigeon is not related to the New World mourning doves (Zenaida) as many authors have suggested, but is the sister taxon of all other New World pigeons (Patagioenas). Biogeographic analysis suggests the Passenger Pigeon lineage may have colonized North America from Asia, and subsequently dispersed into South America, leading to a more extensive radiation of New World pigeons. Copyright 2010. Published by Elsevier Inc.

  4. Natural selection shaped the rise and fall of passenger pigeon genomic diversity.

    Science.gov (United States)

    Murray, Gemma G R; Soares, André E R; Novak, Ben J; Schaefer, Nathan K; Cahill, James A; Baker, Allan J; Demboski, John R; Doll, Andrew; Da Fonseca, Rute R; Fulton, Tara L; Gilbert, M Thomas P; Heintzman, Peter D; Letts, Brandon; McIntosh, George; O'Connell, Brendan L; Peck, Mark; Pipes, Marie-Lorraine; Rice, Edward S; Santos, Kathryn M; Sohrweide, A Gregory; Vohr, Samuel H; Corbett-Detig, Russell B; Green, Richard E; Shapiro, Beth

    2017-11-17

    The extinct passenger pigeon was once the most abundant bird in North America, and possibly the world. Although theory predicts that large populations will be more genetically diverse, passenger pigeon genetic diversity was surprisingly low. To investigate this disconnect, we analyzed 41 mitochondrial and 4 nuclear genomes from passenger pigeons and 2 genomes from band-tailed pigeons, which are passenger pigeons' closest living relatives. Passenger pigeons' large population size appears to have allowed for faster adaptive evolution and removal of harmful mutations, driving a huge loss in their neutral genetic diversity. These results demonstrate the effect that selection can have on a vertebrate genome and contradict results that suggested that population instability contributed to this species's surprisingly rapid extinction. Copyright © 2017, American Association for the Advancement of Science.

  5. The de novo assembly of mitochondrial genomes of the extinct passenger pigeon (Ectopistes migratorius with next generation sequencing.

    Directory of Open Access Journals (Sweden)

    Chih-Ming Hung

    Full Text Available The information from ancient DNA (aDNA provides an unparalleled opportunity to infer phylogenetic relationships and population history of extinct species and to investigate genetic evolution directly. However, the degraded and fragmented nature of aDNA has posed technical challenges for studies based on conventional PCR amplification. In this study, we present an approach based on next generation sequencing to efficiently sequence the complete mitochondrial genome (mitogenome of two extinct passenger pigeons (Ectopistes migratorius using de novo assembly of massive short (90 bp, paired-end or single-end reads. Although varying levels of human contamination and low levels of postmortem nucleotide lesion were observed, they did not impact sequencing accuracy. Our results demonstrated that the de novo assembly of shotgun sequence reads could be a potent approach to sequence mitogenomes, and offered an efficient way to infer evolutionary history of extinct species.

  6. The De Novo Assembly of Mitochondrial Genomes of the Extinct Passenger Pigeon (Ectopistes migratorius) with Next Generation Sequencing

    Science.gov (United States)

    Hung, Chih-Ming; Lin, Rong-Chien; Chu, Jui-Hua; Yeh, Chia-Fen; Yao, Chiou-Ju; Li, Shou-Hsien

    2013-01-01

    The information from ancient DNA (aDNA) provides an unparalleled opportunity to infer phylogenetic relationships and population history of extinct species and to investigate genetic evolution directly. However, the degraded and fragmented nature of aDNA has posed technical challenges for studies based on conventional PCR amplification. In this study, we present an approach based on next generation sequencing to efficiently sequence the complete mitochondrial genome (mitogenome) of two extinct passenger pigeons (Ectopistes migratorius) using de novo assembly of massive short (90 bp), paired-end or single-end reads. Although varying levels of human contamination and low levels of postmortem nucleotide lesion were observed, they did not impact sequencing accuracy. Our results demonstrated that the de novo assembly of shotgun sequence reads could be a potent approach to sequence mitogenomes, and offered an efficient way to infer evolutionary history of extinct species. PMID:23437111

  7. Using Digital 3D Scanning to Create “Artifictions” of the Passenger Pigeon and Harelip Sucker, Two Extinct Species in Eastern North America: The Future Examines the Past

    Directory of Open Access Journals (Sweden)

    Bruce L. Manzano

    2015-12-01

    Full Text Available The Virtual Curation Laboratory at Virginia Commonwealth University created 3D representations of digital morphological models, termed “artifictions,” of several bone elements from two extinct animals, the passenger pigeon (Ectopistes migratorius Linnaeus Columbidae and the harelip sucker (Moxostoma lacerum Jordan and Brayton Catostomidae. Procuring recent comparative reference skeletons these species is extremely difficult. The creation of artifictions, 3D printed replicas of skeletal remains, aims to help researchers become familiar with the bones of harelip sucker and passenger pigeon to facilitate morphological identification of remains of these species within archaeological assemblages. Here, we discuss the two species, the techniques used to create digital topological models of individual skeletal elements, and the obstacles encountered regarding 3D printed artifictions in zooarchaeology.

  8. Complete mitochondrial genomes of living and extinct pigeons revise the timing of the columbiform radiation.

    Science.gov (United States)

    Soares, André E R; Novak, Ben J; Haile, James; Heupink, Tim H; Fjeldså, Jon; Gilbert, M Thomas P; Poinar, Hendrik; Church, George M; Shapiro, Beth

    2016-10-26

    Pigeons and doves (Columbiformes) are one of the oldest and most diverse extant lineages of birds. However, the nature and timing of the group's evolutionary radiation remains poorly resolved, despite recent advances in DNA sequencing and assembly and the growing database of pigeon mitochondrial genomes. One challenge has been to generate comparative data from the large number of extinct pigeon lineages, some of which are morphologically unique and therefore difficult to place in a phylogenetic context. We used ancient DNA and next generation sequencing approaches to assemble complete mitochondrial genomes for eleven pigeons, including the extinct Ryukyu wood pigeon (Columba jouyi), the thick-billed ground dove (Alopecoenas salamonis), the spotted green pigeon (Caloenas maculata), the Rodrigues solitaire (Pezophaps solitaria), and the dodo (Raphus cucullatus). We used a Bayesian approach to infer the evolutionary relationships among 24 species of living and extinct pigeons and doves. Our analyses indicate that the earliest radiation of the Columbidae crown group most likely occurred during the Oligocene, with continued divergence of major clades into the Miocene, suggesting that diversification within the Columbidae occurred more recently than has been reported previously.

  9. Are Humans too Numerous to Become Extinct?

    OpenAIRE

    Cairns, John

    2009-01-01

    Some claim that humans are too numerous to become extinct. However, passenger pigeon, once the most numerous birds on the planet, are now extinct. For years, humankind has been damaging its habitat, discharging toxic chemicals into the environment, and having harmful effects on agricultural productivity due to climate change. Humankind s extinction depends on the continuation of various human activities including economic growth, addiction to fossil fuel, over consumption, overpopulation, oc...

  10. From dinosaurs to dodos: who could and should we de-extinct?

    OpenAIRE

    Jones, Kate Elizabeth

    2014-01-01

    Reviving extinct species with new synthetic biology tools is as exciting an idea as it is controversial. Genomic manipulation of extinct species’ close relatives and/or cloning suitably preserved cells are the two main ways synthetic biology could be used to revive species. Discussions of where to target initial revival efforts have focused on species’ charisma (e.g. Woolly mammoth, Passenger pigeon) with less emphasis on feasibility or the ecological, ethical and legal considerations. Here I...

  11. Husbandry protocols for the Band-tailed pigeon, Patagioenas fasciata albilinea, at the WCS, Bronx Zoo for future conservation management programs.

    Science.gov (United States)

    Oehler, David A; Novak, Ben J; Schmid, Susan C; Huth, Ken J; Totha, Aniko I; Audhya, Tapan

    2018-01-01

    From 2015 to 2016 we determined the husbandry protocols involved in the captive rearing of the Band-tailed Pigeon (BTPI), Patagioenas fascinate albilinea, for use as a tool in the future management of like extant and extinct avian taxa. Current and historical ex-situ conservation management of BTPIs and the closely related Passenger Pigeon, Ectopistes migratorius, is limited in scope and required further examination. Focus on the BTPI within zoos and private aviculture facilities is currently lacking. New pressures on the wild populations and future examination of the parameters involved in the possible restoration of the Passenger Pigeon may rely on a complete understanding of these conservation management techniques. Here we report on the establishment of a colony of BTPIs, at the Wildlife Conservation Society (WCS), and detail the progress attained. A confiscated group of BTPIs was presented to WCS and allowed us to set up the colony, document the husbandry involved, and monitor neonatal development and the factors that influence that development. The information has provided a better understanding of the BTPI and has implications for the future conservation management of this and like species. © 2017 Wiley Periodicals, Inc.

  12. A good time to leave?: the sunk time effect in pigeons.

    Science.gov (United States)

    Magalhães, Paula; White, K Geoffrey

    2014-06-01

    Persistence in a losing course of action due to prior investments of time, known as the sunk time effect, has seldom been studied in nonhuman animals. On every trial in the present study, pigeons were required to choose between two response keys. Responses on one key produced food after a short fixed interval (FI) of time on some trials, or on other trials, no food (Extinction) after a longer time. FI and Extinction trials were not differently signaled, were equiprobable, and alternated randomly. Responses on a second Escape key allowed the pigeon to terminate the current trial and start a new one. The optimal behavior was for pigeons to peck the escape key once the duration equivalent to the short FI had elapsed without reward. Durations of the short FI and the longer Extinction schedules were varied over conditions. In some conditions, the pigeons suboptimally responded through the Extinction interval, thus committing the sunk time effect. The absolute duration of the short FI had no effect on the choice between persisting and escaping. Instead, the ratio of FI and Extinction durations determined the likelihood of persistence during extinction. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. From dinosaurs to dodos: who could and should we de-extinct?

    Directory of Open Access Journals (Sweden)

    Kate Elizabeth Jones

    2014-03-01

    Full Text Available Reviving extinct species with new synthetic biology tools is as exciting an idea as it is controversial. Genomic manipulation of extinct species’ close relatives and/or cloning suitably preserved cells are the two main ways synthetic biology could be used to revive species. Discussions of where to target initial revival efforts have focused on species’ charisma (e.g. Woolly mammoth, Passenger pigeon with less emphasis on feasibility or the ecological, ethical and legal considerations. Here I discuss who we could and should de-extinct, focussing on these latter criteria. Given the current devastating anthropogenic pressures on biodiversity, I suggest that a better use of de-extinction technologies would be to focus them on preventing species extinctions by restoring populations of critically endangered species. For example, this could be through increasing population numbers through cloning or genomic manipulation to better enable susceptible species to adapt to global change or by restoring genetic diversity by reviving extinct sub-species (e.g. Quagga, Barbary lion. This idea circumvents many of the criticisms of de-extinction from conservationists, whilst retaining public interest in de-extinction.

  14. The mysterious Spotted Green Pigeon and its relation to the Dodo and its kindred.

    Science.gov (United States)

    Heupink, Tim H; van Grouw, Hein; Lambert, David M

    2014-07-16

    The closely related and extinct Dodo (Raphus cucullatus) and Rodrigues Solitaire (Pezophaps solitaria), both in the subfamily Raphinae, are members of a clade of morphologically very diverse pigeons. Genetic analyses have revealed that the Nicobar Pigeon (Caloenas nicobarica) is the closest living relative of these birds, thereby highlighting their ancestors' remarkable migration and morphological evolution. The Spotted Green Pigeon (Caloenas maculata) was described in 1783 and showed some similarities to the Nicobar Pigeon. Soon however the taxon fell into obscurity, as it was regarded as simply an abnormal form of the Nicobar Pigeon. The relationship between both taxa has occasionally been questioned, leading some ornithologists to suggest that the two may in fact be different taxa. Today only one of the original two specimens survives and nothing is known about the origin of the taxon. Due to its potential close relationship, the Spotted Green Pigeon may hold clues to the historical migration, isolation and morphological evolution of the Dodo and its kindred. We use ancient DNA methodologies to investigate the phylogeny and authenticity of the Spotted Green Pigeon. A novel extraction method with the ability to retain and purify heavily fragmented DNA is used to investigate two feathers from the sole surviving specimen. Maximum Likelihood phylogenetic analyses reveal that the Spotted Green Pigeon is a unique lineage and together with the Nicobar Pigeon, is basal to the Dodo and Rodrigues Solitaire. The distance observed for the Spotted Green Pigeon and Nicobar Pigeon is larger than that observed within other Pigeon species, indicating that the Spotted Green pigeon is a unique taxon, thereby also indicating it is a genuine addition to the list of extinct species. The phylogenetic placement of the Spotted Green Pigeon indicates that the ancestors of both Caloenas and therefore Raphinae displayed and shared the following traits: ability of flight, semi

  15. Co-occurrence of Mycoplasma Species and Pigeon Herpesvirus-1 Infection in Racing Pigeons ( Columba livia).

    Science.gov (United States)

    Hellebuyck, Tom; Göbel, Stephan; Pasmans, Frank; Adriaensen, Connie; Martel, An

    2017-12-01

    Oropharyngeal swab samples were collected from 438 live racing pigeons ( Columba livia), with and without signs of respiratory disease, that were housed in 220 lofts in 3 provinces in the western part of the Netherlands. Polymerase chain reaction (PCR) was used to identify Mycoplasma species and pigeon herpesvirus-1 (PHV-1) from the samples. In 8.6% of the pigeon lofts tested, signs of respiratory disease were present in pigeons at sampling, and in 30.9% of the sampled pigeon lofts, respiratory signs were observed in pigeons during the 6-month period immediately before sampling. A total of 39.8% of tested pigeons (54.5% of tested lofts) were positive for Mycoplasma species, and 30.6% of tested pigeons (48.6% of tested lofts) were positive for PHV-1. In 15.8% of the tested pigeons (26.8% of tested pigeon lofts), coinfection by Mycoplasma species and PHV-1 was identified. The number of pigeon lofts having pigeons coinfected by Mycoplasma species and PHV-1 was higher than that where only one of the infections was identified. Neither the presence of Mycoplasma species, PHV-1, nor the co-occurrence of both infections was significantly associated with signs of respiratory disease.

  16. Resistance to extinction, generalization decrement, and conditioned reinforcement.

    Science.gov (United States)

    Dulaney, Alana E; Bell, Matthew C

    2008-06-01

    This study investigated generalization decrement during an extinction resistance-to-change test for pigeon key pecking using a two-component multiple schedule with equal variable-interval 3-min schedules and different reinforcer amounts (one component presented 2-s access to reinforcement and the other 8s). After establishing baseline responding, subjects were assigned to one of the two extinction conditions: hopper stimuli (hopper and hopper light were activated but no food was available) or Control (inactive hopper and hopper light). Responding in the 8-s component was more resistant to extinction than responding in the 2-s component, the hopper stimuli group was more resistant to extinction compared to the Control group, and an interaction between amount of reinforcement, extinction condition, and session block was present. This finding supports generalization decrement as a factor that influences resistance to extinction. Hopper-time data (the amount of time subjects spent with their heads in the hopper) were compared to resistance-to-change data in an investigation of the role of conditioned reinforcement on resistance to change.

  17. Hungry pigeons make suboptimal choices, less hungry pigeons do not.

    Science.gov (United States)

    Laude, Jennifer R; Pattison, Kristina F; Zentall, Thomas R

    2012-10-01

    Hungry animals will often choose suboptimally by being attracted to reliable signals for food that occur infrequently (they gamble) over less reliable signals for food that occur more often. That is, pigeons prefer an option that 50 % of the time provides them with a reliable signal for the appearance of food but 50 % of the time provides them with a reliable signal for the absence of food (overall 50 % reinforcement) over an alternative that always provides them with a signal for the appearance of food 75 % of the time (overall 75 % reinforcement). The pigeons appear to choose impulsively for the possibility of obtaining the reliable signal for reinforcement. There is evidence that greater hunger is associated with greater impulsivity. We tested the hypothesis that if the pigeons were less hungry, they would be less impulsive and, thus, would choose more optimally (i.e., on the basis of the overall probability of reinforcement). We found that hungry pigeons choose the 50 % reinforcement alternative suboptimally but less hungry pigeons prefer the more optimal 75 % reinforcement. Paradoxically, pigeons that needed the food more received less of it. These findings have implications for how level of motivation may also affect human suboptimal choice (e.g., purchase of lottery tickets and playing slot machines).

  18. Human infestation by pigeon fleas (Ceratophyllus columbae) from feral pigeons.

    Science.gov (United States)

    Haag-Wackernagel, Daniel; Spiewak, Radosław

    2004-01-01

    The report concerns a married couple who were repeatedly invaded by pigeon fleas (Ceratophyllus columbae) over a period of 2 months. The source of the fleas was a pair of breeding feral pigeons (Columba livia). The birds' nest was located in the attic immediately above the couple's apartment, and the fleas found their way along an unsealed heating pipe. The people encountered up to 40 bites per night. With invasions repeated almost every night, the man gradually developed an allergic urticarial reaction. The most traumatic experience for the couple, however, was to learn that they were invaded by fleas (initially, they had presumed they were bothered by mosquitoes). This information resulted in severe psychological distress with phobic reactions and insomnia. Despite the successful removal of the fleas and the pigeons that were source of the pest, parasitophobia of the man persisted over the following 4 months. This case is discussed from the broader aspect of health risks related to feral pigeons and animal fleas. Also summarised are previous observations on people invaded by pigeon fleas.

  19. Pigeon tick bite

    DEFF Research Database (Denmark)

    Rolla, G; Heffler, E; Boita, M

    2018-01-01

    Anaphylaxis is a serious systemic allergic reaction with rapid onset and potentially life-threatening. We report in detail a case of severe nocturnal anaphylaxis due to pigeon tick bite showing the diagnostic value of the extract and the recombinant allergen in the diagnostic procedures (basophil...... reagents. Because of the growing number of pigeons in Middle and Southern Europe cities, some cases of idiopathic anaphylaxis could potentially be caused by A. reflexus in those countries. The identification of pigeon ticks as a trigger of anaphylaxis would greatly improve medical care and advice...

  20. Human infestation by pigeon fleas (Ceratophyllus columbae) from feral pigeons.

    NARCIS (Netherlands)

    Haag-Wackernagel, D; Spiewak, R.W.

    2004-01-01

    The report concerns a married couple who were repeatedly invaded by pigeon fleas (Ceratophyllus columbae) over a period of 2 months. The source of the fleas was a pair of breeding feral pigeons (Columba livia). The birds' nest was located in the attic immediately above the couple's apartment, and

  1. Experience with dynamic reinforcement rates decreases resistance to extinction.

    Science.gov (United States)

    Craig, Andrew R; Shahan, Timothy A

    2016-03-01

    The ability of organisms to detect reinforcer-rate changes in choice preparations is positively related to two factors: the magnitude of the change in rate and the frequency with which rates change. Gallistel (2012) suggested similar rate-detection processes are responsible for decreases in responding during operant extinction. Although effects of magnitude of change in reinforcer rate on resistance to extinction are well known (e.g., the partial-reinforcement-extinction effect), effects of frequency of changes in rate prior to extinction are unknown. Thus, the present experiments examined whether frequency of changes in baseline reinforcer rates impacts resistance to extinction. Pigeons pecked keys for variable-interval food under conditions where reinforcer rates were stable and where they changed within and between sessions. Overall reinforcer rates between conditions were controlled. In Experiment 1, resistance to extinction was lower following exposure to dynamic reinforcement schedules than to static schedules. Experiment 2 showed that resistance to presession feeding, a disruptor that should not involve change-detection processes, was unaffected by baseline-schedule dynamics. These findings are consistent with the suggestion that change detection contributes to extinction. We discuss implications of change-detection processes for extinction of simple and discriminated operant behavior and relate these processes to the behavioral-momentum based approach to understanding extinction. © 2016 Society for the Experimental Analysis of Behavior.

  2. [Pigeon sport and animal rights].

    Science.gov (United States)

    Warzecha, M

    2007-03-01

    To begin, a short overview of the organization and the realization of the racing pigeon sport. Some physiological facts, relevant to racing pigeons, will be touched on. Lastly, a focus on the flights, their completion and the problems involved with the, in some cases, high number of lost pigeons. The German Club of Pigeon Breeders, has made improvements but, it is certainly not enough. The topic of "City Pigeons" will be briefed. The final part deals with pertinent animal rights issues, causes of mishaps, and some rectifying possibilities, which are available to the government veterinarian. Special emphasis will be placed on the international uniformity of this issue. The lecture should prove that there is a need for every government veterinarian to become actively involved, because the described problematic has a major effect on a very large number of animals.

  3. Bird Lice (Mallophaga, Philopteridae, Menoponidae of Domestic Pigeons on Specialized Pigeon Breeding Farms in Poltava

    Directory of Open Access Journals (Sweden)

    Kolomak I. O.

    2017-12-01

    Full Text Available The species composition of pigeon lice parasitic on pigeons of ornamental breeds on the specialized closed-type farm (Poltava was studied. Five species of these ectoparasites were registered: Columbicola columbae Linnaeus, 1758, Campanulotes compar Burmeister, 1838, (Philopteridae, Ischnocera, Bonomiella columbae Emerson, 1957, Hohorstiella lata Piaget, 1880 and Neocolpocephalus turbinatum (Denny, 1842 (Menoponidae, Amblycera. For each species, the data on infection prevalence, intensity and abundance were obtained. High prevalence of infection was registered for all pigeon lice species, while the intensity and, especially, the abundance were considerably different. C. columbae turned out to be the most abundant. B. columbae was rather common. The peculiarities of pigeon lice species localization on the host body were investigated. During the intensive infection of pigeons with lice, the complex of clinical signs is manifested, which testifies about considerable effect of these parasites on the host. The highest pathogenicity is characteristic for H. lata, which usually feeds on blood and lymph.

  4. Identification of a novel aviadenovirus, designated pigeon adenovirus 2 in domestic pigeons (Columba livia).

    Science.gov (United States)

    Teske, L; Rubbenstroth, D; Meixner, M; Liere, K; Bartels, H; Rautenschlein, S

    2017-01-02

    The young pigeon disease syndrome (YPDS) affects mainly young pigeons of less than one year of age and leads to crop stasis, vomitus, diarrhea, anorexia and occasionally death. This disease is internationally a major health problem because of its seasonal appearance during competitions such as homing pigeon races or exhibitions of ornamental birds. While the etiology of YPDS is still unclear, adenoviruses are frequently discussed as potential causative agents. Electron microscopy of feces from a YPDS outbreak revealed massive shedding of adenovirus-like particles. Whole genome sequencing of this sample identified a novel adenovirus tentatively named pigeon adenovirus 2 (PiAdV-2). Phylogenetic and comparative genome analysis suggest PiAdV-2 to belong to a new species within the genus Aviadenovirus, for which we propose the name Pigeon aviadenovirus B. The PiAdV-2 genome shares 54.9% nucleotide sequence identity with pigeon adenovirus 1 (PiAdV-1). In a screening of further YPDS-affected flocks two variants of PiAdV-2 (variant A and B) were detected which shared 97.6% nucleotide identity of partial polymerase sequences, but only 79.7% nucleotide identity of partial hexon sequences. The distribution of both PiAdV-2 variants was further investigated in fecal samples collected between 2008 and 2015 from healthy or YPDS-affected racing pigeons of different lofts. Independent of their health status, approximately 20% of young and 13% of adult pigeon flocks harbored PiAdV-2 variants. Birds were free of PiAdV-1 or other aviadenoviruses as determined by PCRs targeting the aviadenovirus polymerase or the PiAdV-1 fiber gene, respectively. In conclusion, there is no indication of a correlation between YPDS outbreaks and the presence of PiAdV-2 or other aviadenoviruses, arguing against an causative role in this disease complex. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Human infestation by pigeon fleas (Ceratophyllus columbae) from feral pigeons.

    OpenAIRE

    Haag-Wackernagel, D; Spiewak, R.W.

    2004-01-01

    The report concerns a married couple who were repeatedly invaded by pigeon fleas (Ceratophyllus columbae) over a period of 2 months. The source of the fleas was a pair of breeding feral pigeons (Columba livia). The birds' nest was located in the attic immediately above the couple's apartment, and the fleas found their way along an unsealed heating pipe. The people encountered up to 40 bites per night. With invasions repeated almost every night, the man gradually developed an allergic urticari...

  6. Small-scale spatial cognition in pigeons.

    Science.gov (United States)

    Cheng, Ken; Spetch, Marcia L; Kelly, Debbie M; Bingman, Verner P

    2006-05-01

    Roberts and Van Veldhuizen's [Roberts, W.A., Van Veldhuizen, N., 1985. Spatial memory in pigeons on the radial maze. J. Exp. Psychol.: Anim. Behav. Proc. 11, 241-260] study on pigeons in the radial maze sparked research on landmark use by pigeons in lab-based tasks as well as variants of the radial-maze task. Pigeons perform well on open-field versions of the radial maze, with feeders scattered on the laboratory floor. Pigeons can also be trained to search precisely for buried food. The search can be based on multiple landmarks, but is sometimes controlled by just one or two landmarks, with the preferred landmarks varying across individuals. Findings are similar in landmark-based searching on a computer monitor and on a lab floor, despite many differences between the two kinds of tasks. A number of general learning principles are found in landmark-based searching, such as cue competition, generalization and peak shift, and selective attention. Pigeons also learn the geometry of the environment in which they are searching. Neurophysiological studies have implicated the hippocampal formation (HF) in avian spatial cognition, with the right hippocampus hypothesized to play a more important role in the spatial recognition of goal locations. Most recently, single-cell recording from the pigeon's hippocampal formation has revealed cells with different properties from the classic 'place' cells of rats, as well as differences in the two sides of the hippocampus.

  7. Autoshaping and paleostriatal lesions in the pigeon.

    Science.gov (United States)

    Mitchell, J A

    1983-07-01

    Three experiments were conducted with the pigeon (Columbia livia) to investigate the effects of bilateral electrolytic lesions of the paleostriatum on classical conditioning paradigms. In Experiment 1 naive subjects were given autoshaping training to a white centre key light and it was found that paleostriatal pigeons showed higher peck rates than unoperated controls. A further group of naive paleostriatal pigeons showed higher rates of autoshaped responding but did not differ from controls on a successive autoshaping discrimination with colour (Experiment 2A) or striped (Experiment 2B) stimuli. In Experiment 3 paleostriatal pigeons performed better than controls on a go, no-go alternation. The higher response rates shown by paleostriatal pigeons during autoshaping could not readily be explained in terms of a (non-associative) motor disturbance such as a tremor which could have caused multiple key pecks to be emitted in view of the demonstrations of unimpaired discrimination (Experiment 2) and better alternation (Experiment 3). Instead, the results suggest that paleostriatal pigeons may show potentiated classical conditioning.

  8. ( Voandze subterranean ) and pigeon pea

    African Journals Online (AJOL)

    Formulation and evaluation of complementary food based on bambara nut ( Voandze subterranean ) and pigeon pea ( Cajanus cajan ) ... Nigerian Journal of Nutritional Sciences ... Objectives: The study formulated and evaluated complementary food made from composites of maize, bambara nut and pigeon pea. Materials ...

  9. Variation in extinction risk among birds: chance or evolutionary predisposition?

    Science.gov (United States)

    Bennett, P. M.; Owens, I. P. F.

    1997-01-01

    Collar et al. (1994) estimate that of the 9,672 extant species of bird, 1,111 are threatened by extinction. Here, we test whether these threatened species are simply a random sample of birds, or whether there is something about their biology that predisposes them to extinction. We ask three specific questions. First, is extinction risk randomly distributed among families? Second, which families, if any, contain more, or less, threatened species than would be expected by chance? Third, is variation between taxa in extinction risk associated with variation in either body size or fecundity? Extinction risk is not randomly distributed among families. The families which contain significantly more threatened species than expected are the parrots (Psittacidae), pheasants and allies (Phasianidae), albatrosses and allies (Procellariidae), rails (Rallidae), cranes (Gruidae), cracids (Cracidae), megapodes (Megapodidae) and pigeons (Columbidae). The only family which contains significantly fewer threatened species than expected is the woodpeckers (Picidae). Extinction risk is also not distributed randomly with respect to fecundity or body size. Once phylogeny has been controlled for, increases in extinction risk are independently associated with increases in body size and decreases in fecundity. We suggest that this is because low rates of fecundity, which evolved many tens of millions of years ago, predisposed certain lineages to extinction. Low-fecundity populations take longer to recover if they are reduced to small sizes and are, therefore, more likely to go extinct if an external force causes an increase in the rate of mortality, thereby perturbing the natural balance between fecundity and mortality.

  10. Scene-Based Contextual Cueing in Pigeons

    Science.gov (United States)

    Wasserman, Edward A.; Teng, Yuejia; Brooks, Daniel I.

    2014-01-01

    Repeated pairings of a particular visual context with a specific location of a target stimulus facilitate target search in humans. We explored an animal model of such contextual cueing. Pigeons had to peck a target which could appear in one of four locations on color photographs of real-world scenes. On half of the trials, each of four scenes was consistently paired with one of four possible target locations; on the other half of the trials, each of four different scenes was randomly paired with the same four possible target locations. In Experiments 1 and 2, pigeons exhibited robust contextual cueing when the context preceded the target by 1 s to 8 s, with reaction times to the target being shorter on predictive-scene trials than on random-scene trials. Pigeons also responded more frequently during the delay on predictive-scene trials than on random-scene trials; indeed, during the delay on predictive-scene trials, pigeons predominately pecked toward the location of the upcoming target, suggesting that attentional guidance contributes to contextual cueing. In Experiment 3, involving left-right and top-bottom scene reversals, pigeons exhibited stronger control by global than by local scene cues. These results attest to the robustness and associative basis of contextual cueing in pigeons. PMID:25546098

  11. Pigeons home faster through polluted air

    OpenAIRE

    Zhongqiu Li; Franck Courchamp; Daniel T. Blumstein

    2016-01-01

    Air pollution, especially haze pollution, is creating health issues for both humans and other animals. However, remarkably little is known about how animals behaviourally respond to air pollution. We used multiple linear regression to analyse 415 pigeon races in the North China Plain, an area with considerable air pollution, and found that while the proportion of pigeons successfully homed was not influenced by air pollution, pigeons homed faster when the air was especially polluted. Our resu...

  12. Geochemistry and hydrology of perched groundwater springs: assessing elevated uranium concentrations at Pigeon Spring relative to nearby Pigeon Mine, Arizona (USA)

    Science.gov (United States)

    Beisner, Kimberly R.; Paretti, Nicholas; Tillman, Fred; Naftz, David L.; Bills, Donald; Walton-Day, Katie; Gallegos, Tanya J.

    2017-01-01

    The processes that affect water chemistry as the water flows from recharge areas through breccia-pipe uranium deposits in the Grand Canyon region of the southwestern United States are not well understood. Pigeon Spring had elevated uranium in 1982 (44 μg/L), compared to other perched springs (2.7–18 μg/L), prior to mining operations at the nearby Pigeon Mine. Perched groundwater springs in an area around the Pigeon Mine were sampled between 2009 and 2015 and compared with material from the Pigeon Mine to better understand the geochemistry and hydrology of the area. Two general groups of perched groundwater springs were identified from this study; one group is characterized by calcium sulfate type water, low uranium activity ratio 234U/238U (UAR) values, and a mixture of water with some component of modern water, and the other group by calcium-magnesium sulfate type water, higher UAR values, and radiocarbon ages indicating recharge on the order of several thousand years ago. Multivariate statistical principal components analysis of Pigeon Mine and spring samples indicate Cu, Pb, As, Mn, and Cd concentrations distinguished mining-related leachates from perched groundwater springs. The groundwater potentiometric surface indicates that perched groundwater at Pigeon Mine would likely flow toward the northwest away from Pigeon Spring. The geochemical analysis of the water, sediment and rock samples collected from the Snake Gulch area indicate that the elevated uranium at Pigeon Spring is likely related to a natural source of uranium upgradient from the spring and not likely related to the Pigeon Mine.

  13. Effectiveness of Gel Repellents on Feral Pigeons

    Directory of Open Access Journals (Sweden)

    Birte Stock

    2013-12-01

    Full Text Available Millions of feral pigeons (Columba livia live in close association with the human population in our cities. They pose serious health risks to humans and lead to high economic loss due to damage caused to buildings. Consequently, house owners and city authorities are not willing to allow pigeons on their buildings. While various avian repellents are regularly introduced onto the market, scientific proof of efficacy is lacking. This study aimed at testing the effectiveness of two avian gel repellents and additionally examined their application from animal welfare standpoint. The gels used an alleged tactile or visual aversion of the birds, reinforced by additional sensory cues. We mounted experimental shelves with the installed repellents in a pigeon loft and observed the behavior of free-living feral pigeons towards the systems. Both gels showed a restricted, transient repellent effect, but failed to prove the claimed complete effectiveness. Additionally, the gels’ adhesive effect remains doubtful in view of animal welfare because gluing of plumage presents a risk to feral pigeons and also to other non-target birds. This study infers that both gels lack the promised complete efficacy, conflict with animal welfare concerns and are therefore not suitable for feral pigeon management in urban areas.

  14. Evidence for discrete landmark use by pigeons during homing.

    Science.gov (United States)

    Mora, Cordula V; Ross, Jeremy D; Gorsevski, Peter V; Chowdhury, Budhaditya; Bingman, Verner P

    2012-10-01

    Considerable efforts have been made to investigate how homing pigeons (Columba livia f. domestica) are able to return to their loft from distant, unfamiliar sites while the mechanisms underlying navigation in familiar territory have received less attention. With the recent advent of global positioning system (GPS) data loggers small enough to be carried by pigeons, the role of visual environmental features in guiding navigation over familiar areas is beginning to be understood, yet, surprisingly, we still know very little about whether homing pigeons can rely on discrete, visual landmarks to guide navigation. To assess a possible role of discrete, visual landmarks in navigation, homing pigeons were first trained to home from a site with four wind turbines as salient landmarks as well as from a control site without any distinctive, discrete landmark features. The GPS-recorded flight paths of the pigeons on the last training release were straighter and more similar among birds from the turbine site compared with those from the control site. The pigeons were then released from both sites following a clock-shift manipulation. Vanishing bearings from the turbine site continued to be homeward oriented as 13 of 14 pigeons returned home. By contrast, at the control site the vanishing bearings were deflected in the expected clock-shift direction and only 5 of 13 pigeons returned home. Taken together, our results offer the first strong evidence that discrete, visual landmarks are one source of spatial information homing pigeons can utilize to navigate when flying over a familiar area.

  15. Atherosclerosis in familial lines of pigeons fed exogenous cholesterol.

    Science.gov (United States)

    Patton, N M; Brown, R V; Middleton, C C

    1975-01-01

    Exogenous cholesterol was fed to F1 pigeons of high and low serum cholesterol differentiated lines of White Carneau and Racing Homer pigeons that had previously been developed by selection and positive assortive mating. The serum cholesterol response of the various high and low lines was dependent upon the breed and the amount of cholesterol in the diet. Racing Homer pigeons were found to be more resistant to aortic atherosclerosis and more susceptible to coronary atherosclerosis than White Carneau pigeons. Data from necropsy examinations showed significant differences in both aortic and coronary atherosclerosis between lines within the White Carneau breed, but no differences between lines of the Racing Homer breed. Mean organ weights for the 4 lines of pigeons were reported.

  16. Pigeons can discriminate "good" and "bad" paintings by children.

    Science.gov (United States)

    Watanabe, Shigeru

    2010-01-01

    Humans have the unique ability to create art, but non-human animals may be able to discriminate "good" art from "bad" art. In this study, I investigated whether pigeons could be trained to discriminate between paintings that had been judged by humans as either "bad" or "good". To do this, adult human observers first classified several children's paintings as either "good" (beautiful) or "bad" (ugly). Using operant conditioning procedures, pigeons were then reinforced for pecking at "good" paintings. After the pigeons learned the discrimination task, they were presented with novel pictures of both "good" and "bad" children's paintings to test whether they had successfully learned to discriminate between these two stimulus categories. The results showed that pigeons could discriminate novel "good" and "bad" paintings. Then, to determine which cues the subjects used for the discrimination, I conducted tests of the stimuli when the paintings were of reduced size or grayscale. In addition, I tested their ability to discriminate when the painting stimuli were mosaic and partial occluded. The pigeons maintained discrimination performance when the paintings were reduced in size. However, discrimination performance decreased when stimuli were presented as grayscale images or when a mosaic effect was applied to the original stimuli in order to disrupt spatial frequency. Thus, the pigeons used both color and pattern cues for their discrimination. The partial occlusion did not disrupt the discriminative behavior suggesting that the pigeons did not attend to particular parts, namely upper, lower, left or right half, of the paintings. These results suggest that the pigeons are capable of learning the concept of a stimulus class that humans name "good" pictures. The second experiment showed that pigeons learned to discriminate watercolor paintings from pastel paintings. The subjects showed generalization to novel paintings. Then, as the first experiment, size reduction test

  17. Visual performance of pigeons following hippocampal lesions.

    Science.gov (United States)

    Bingman, V P; Hodos, W

    1992-11-15

    The effect of hippocampal lesions on performance in two psychophysical measures of spatial vision (acuity and size-difference threshold) was examined in 7 pigeons. No difference between the preoperative and postoperative thresholds of the experimental birds was found. The visual performance of pigeons in the psychophysical tasks failed to reveal a role of the hippocampal formation in vision. The results argue strongly that the behavioral deficits found in pigeons with hippocampal lesions when tested in a variety of memory-related spatial tasks is not based on a defect in spatial vision but impaired spatial cognition.

  18. Coordinated Behaviour in Pigeon Flocks.

    Directory of Open Access Journals (Sweden)

    Makoto Yomosa

    Full Text Available We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii during circling motion, pigeons use a mixture of two idealised and fundamentally different turning strategies, namely, parallel-path and equal-radius type turning. While pigeons tend to maintain their relative position within the flock on average, as in the parallel-path approximation, those who turn later also get behind as in the equal-radius case. Equal-radius type turning also tends to be expressed more during smaller radius turns.

  19. Food choice in the laboratory pigeon.

    Science.gov (United States)

    Biedermann, Traci; Garlick, Dennis; Blaisdell, Aaron P

    2012-09-01

    Although food reward plays a large role in learning and behavioral experiments, there have been few studies examining the most motivating food reward for pigeons. Brown (1969) found that pigeons had a tendency to prefer peas, while Killeen et al. (1993) found pigeons to prefer peas and popcorn in Experiment 1A. We looked to further explore these options as well as expand upon the types of foods examined beyond mainly grains and seeds. Pigeons were presented with six novel foods (granulated peanuts, popping corn, freeze-dried mealworms, bread crumbs, split peas, and sunflower hearts) allocated into two sets of three food items. Once the most consumed food from each food set was determined, they were pooled together with sorghum seeds (a familiar food) to form a third set. Sunflower hearts were the most consumed of all the food items, followed by corn and granulated peanuts. We discuss the potential factors mediating consumption choice, including nutritional profile and food particle size. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Pigeons' Discrimination of Michotte's Launching Effect

    Science.gov (United States)

    Young, Michael E.; Beckmann, Joshua S.; Wasserman, Edward A.

    2006-01-01

    We trained four pigeons to discriminate a Michotte launching animation from three other animations using a go/no-go task. The pigeons received food for pecking at one of the animations, but not for pecking at the others. The four animations featured two types of interactions among objects: causal (direct launching) and noncausal (delayed, distal,…

  1. The Carrier Rate of Newcastle Disease Virus in Pigeons in Owerri ...

    African Journals Online (AJOL)

    Two positive results were recorded for white pigeons, while only one black pigeon showed evidence of NDV. From this study, the carrier rate of NDV in pigeons in Owerri area of Imo State is estimated at 5% Keywords: Carrier Rate, Newcastle Disease Virus, Pigeons. Journal of Medical Laboratory Sciences Vol. 14 (1) 2005: ...

  2. Why Pigeons?

    Science.gov (United States)

    Nevin, John A.

    1993-01-01

    Explains the use of pigeons in behavioral psychology research for modeling human behavior and discusses instructional objectives for humans. Topics addressed include the relationship between response rate and reinforcer rate; resistance to alternative reinforcement; choice and matching; and persistence and reinforcement. (Contains 11 references.)…

  3. Pigeons and peritonitis?

    Science.gov (United States)

    Greaves, I; Kane, K; Richards, N T; Elliott, T S; Adu, D; Michael, J

    1992-01-01

    We report an outbreak of fungal peritonitis due to Candida parapsilosis in 12 patients undergoing chronic ambulatory peritoneal dialysis (CAPD). All 12 patients were treated by removal of the CAPD catheter together with systemic antifungal therapy. There were no peritonitis-related deaths. Four patients were successfully returned to CAPD at a later date. Microbiological investigation during the outbreak demonstrated colonization of various areas of the CAPD Unit and medical ward with the organism. C. parapsilosis was also isolated from pigeon guano obtained from window-sills. The number of cases of peritonitis due to this organism decreased markedly after bird-proof netting was installed. We believe that this is the first report of an outbreak of CAPD peritonitis due to faecal carriage of C. parapsilosis by pigeons.

  4. Further investigations at the Naigani Lapita site (VL 21/5), Fiji : excavation, radiocarbon dating and palaeofaunal extinction

    International Nuclear Information System (INIS)

    Irwin, G.; Worthy, T.H.; Best, S.; Hawkins, S.; Carpenter, J.; Matararaba, S.

    2011-01-01

    This paper brings up-to-date a report by S. Best of initial excavations at Naigani in 1981. The results of subsequent fieldwork in 2000 include the excavation and dating of Lapita-age ovens associated with early settlement and extinct palaeofauna. These include the giant megapode (Megavitiornis altirostris), a species of Ducula pigeon, the giant iguana (Lapitiguana impensa), and probably the endemic crocodile (Volia athollandersoni). The Lapita site of VL 21/5 dates from 900 BC and represents an initial colonising settlement within the Fiji Islands. The period of occupation ended around 750 BC. The significance of Naigani is considered in terms of chronology, ceramic history, economy, extinctions, origins and interactions. (author). 33 refs., 10 figs., 2 tabs.

  5. Do pigeons prefer alternatives that include near-hit outcomes?

    Science.gov (United States)

    Stagner, Jessica P; Case, Jacob P; Sticklen, Mary F; Duncan, Amanda K; Zentall, Thomas R

    2015-07-01

    Pigeons show suboptimal choice on a gambling-like task similar to that shown by humans. Humans also show a preference for gambles in which there are near hits (losses that come close to winning). In the present research, we asked if pigeons would show a preference for alternatives with near-hit-like trials. In Experiment 1, we included an alternative that presented a near hit, in which a stimulus associated with reinforcement (a presumed conditioned reinforcer) changed to a stimulus associated with the absence of reinforcement (a presumed conditioned inhibitor). The pigeons tended to avoid this alternative. In Experiment 2, we varied the duration of the presumed conditioned reinforcer (2 vs. 8 s) that changed to a presumed conditioned inhibitor (8 vs. 2 s) and found that the longer the conditioned reinforcer was presented, the more the pigeons avoided it. In Experiment 3, the near-hit alternative involved an ambiguous stimulus for 8 s that changed to a presumed conditioned reinforcer (or a presumed conditioned inhibitor) for 2 s, but the pigeons still avoided it. In Experiment 4, we controlled for the duration of the conditioned reinforcer by presenting it first for 2 s followed by the ambiguous stimulus for 8 s. Once again, the pigeons avoided the alternative with the near-hit trials. In all 4 experiments, the pigeons tended to avoid alternatives that provided near-hit-like trials. We concluded that humans may be attracted to near-hit trials because near-hit trials give them the illusion of control, whereas this does not appear to be a factor for pigeons. (c) 2015 APA, all rights reserved).

  6. Ectoparasites and intestinal helminths of speckled pigeon ...

    African Journals Online (AJOL)

    Ectoparasites and intestinal helminths of speckled pigeon ( Columba guinea Hartlaub and Finsch 1870) in Zaria, Nigeria. ... Science World Journal ... A total of 30 (20 males and 10 females) Speckled Pigeons trapped from the wild in Zaria and its environs, Nigeria, were examined for ectoparasites and intestinal helminths, ...

  7. Lomba Merpati: Place-making and Communal Signalling within Javanese Pigeon Racing.

    Directory of Open Access Journals (Sweden)

    Leyla Stevens

    2016-02-01

    Full Text Available The project, Lomba Merpati, is a series of photographs and video works documenting pigeon racing in Yogyakarta, Indonesia. Associated as a lower socio-economic class sport and tied up with expressions of Javanese masculinity, pigeon racing occupies a central position within much of the daily social activity of Javanese villages.  The project explores the significance of pigeon training grounds as communal gathering points for young men in Yogyakarta. Comprising short video and photographic portraits, the series focuses on the performative gestures enacted by pigeon fanciers as they train their pigeons for short distance sprinting.

  8. Ethnobotanic importance of plants used in pigeon-breeding in Eastern Spain

    OpenAIRE

    Belda, Antonio; Cort?s, Carolina; Peir?, Victoriano

    2013-01-01

    Background: The importance that birds of the Columbidae family have had throughout history is visible on the Mediterranean coast. Pigeon fancying is the art of breeding and training carrier pigeons and currently, several breeds exist. The sport of racing pigeons consists in covering a distance at maximum possible speed. However, pigeon breeding has another modality called “sport pigeon”, where several males follow a female. This study focusses on ethnobotanical knowledge of native and exotic ...

  9. Pigeon visual short-term memory directly compared to primates.

    Science.gov (United States)

    Wright, Anthony A; Elmore, L Caitlin

    2016-02-01

    Three pigeons were trained to remember arrays of 2-6 colored squares and detect which of two squares had changed color to test their visual short-term memory. Procedures (e.g., stimuli, displays, viewing times, delays) were similar to those used to test monkeys and humans. Following extensive training, pigeons performed slightly better than similarly trained monkeys, but both animal species were considerably less accurate than humans with the same array sizes (2, 4 and 6 items). Pigeons and monkeys showed calculated memory capacities of one item or less, whereas humans showed a memory capacity of 2.5 items. Despite the differences in calculated memory capacities, the pigeons' memory results, like those from monkeys and humans, were all well characterized by an inverse power-law function fit to d' values for the five display sizes. This characterization provides a simple, straightforward summary of the fundamental processing of visual short-term memory (how visual short-term memory declines with memory load) that emphasizes species similarities based upon similar functional relationships. By closely matching pigeon testing parameters to those of monkeys and humans, these similar functional relationships suggest similar underlying processes of visual short-term memory in pigeons, monkeys and humans. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Recording single neurons' action potentials from freely moving pigeons across three stages of learning.

    Science.gov (United States)

    Starosta, Sarah; Stüttgen, Maik C; Güntürkün, Onur

    2014-06-02

    While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed single-neuron activity while animals are acquiring an operantly conditioned response, or when that response is extinguished. But even in these cases, observation periods usually encompass only a single stage of learning, i.e. acquisition or extinction, but not both (exceptions include protocols employing reversal learning; see Bingman et al.(1) for an example). However, acquisition and extinction entail different learning mechanisms and are therefore expected to be accompanied by different types and/or loci of neural plasticity. Accordingly, we developed a behavioral paradigm which institutes three stages of learning in a single behavioral session and which is well suited for the simultaneous recording of single neurons' action potentials. Animals are trained on a single-interval forced choice task which requires mapping each of two possible choice responses to the presentation of different novel visual stimuli (acquisition). After having reached a predefined performance criterion, one of the two choice responses is no longer reinforced (extinction). Following a certain decrement in performance level, correct responses are reinforced again (reacquisition). By using a new set of stimuli in every session, animals can undergo the acquisition-extinction-reacquisition process repeatedly. Because all three stages of learning occur in a single behavioral session, the paradigm is ideal for the simultaneous observation of the spiking output of multiple single neurons. We use pigeons as model systems, but the task can easily be adapted to any other species capable of conditioned discrimination learning.

  11. Prevalence of Haemoproteus spp. in Tumbler Pigeons (Columba livia domestica) in Kirikkale Province, Turkey.

    Science.gov (United States)

    Sürsal, Neslihan; Atan, Perçem; Gökpınar, Sami; Duru, Özkan; Çakmak, Ayşe; Yıldız, Kader

    2017-06-01

    Haemoproteus spp. are common blood parasites of pigeons. They have been reported in pigeons in many regions worldwide, including Turkey. Pigeon breeding is a popular hobby in Kirikkale province, and there is no information about the prevalence of Haemoproteus spp. The present study aimed to determine the prevalence of Haemoproteus spp. in tumbler pigeons in Kirikkale province (Kırıkkale and Yahsihan district). Blood samples were taken from the wing vein of pigeons (n: 173) through microcapillary (with/heparin) tubes between February and March 2016. Blood smears were stained with 5% Giemsa solution. Ectoparasites of the pigeons were collected in separate sealed boxes. Epidemiological data of the sampled pigeons (age and sex) were obtained from the breeders. In total, 23 (%13.2) of 173 pigeons were infected with Haemoproteus spp. Parasite was detected in 73.9% of pigeons over 1 year old and 26.1% of pigeon under 1 year age. Haemoproteus spp. was observed in 56.2% of females (13/23) and 43.4% of males (10/23), Sex-related differences were not observed (p = 0.821). Ectoparasites of the pigeons were identified as Columbicola spp. To the best of our knowledge, this is the first study in Kirikkale province that reported the prevalence of Haemoproteus spp. in pigeons.

  12. Endpoint distinctiveness facilitates analogical mapping in pigeons.

    Science.gov (United States)

    Hagmann, Carl Erick; Cook, Robert G

    2015-03-01

    Analogical thinking necessitates mapping shared relations across two separate domains. We investigated whether pigeons could learn faster with ordinal mapping of relations across two physical dimensions (circle size & choice spatial position) relative to random mapping of these relations. Pigeons were trained to relate six circular samples of different sizes to horizontally positioned choice locations in a six alternative matching-to-sample task. Three pigeons were trained in a mapped condition in which circle size mapped directly onto choice spatial position. Three other pigeons were trained in a random condition in which the relations between size and choice position were arbitrarily assigned. The mapped group showed an advantage over the random group in acquiring this task. In a subsequent second phase, relations between the dimensions were ordinally reversed for the mapped group and re-randomized for the random group. There was no difference in how quickly matching accuracy re-emerged in the two groups, although the mapped group eventually performed more accurately. Analyses suggested this mapped advantage was likely due to endpoint distinctiveness and the benefits of proximity errors during choice responding rather than a conceptual or relational advantage attributable to the common or ordinal mapping of the two dimensions. This potential difficulty in mapping relations across dimensions may limit the pigeons' capacity for more advanced types of analogical reasoning. This article is part of a Special Issue entitled: Tribute to Tom Zentall. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Paramyxovirus-1 in feral pigeons (Columba livia) in Ontario

    Science.gov (United States)

    Johnston, Kathleen M.; Key, Douglas W.

    1992-01-01

    Paramyxovirus-1 (PMV-1) infection was diagnosed in racing pigeons in Ontario during 1985, but it was not until January 1989, that the virus was isolated from feral pigeons (Columba livia) in this province. During an 18 month period beginning January 1988, a total of 43 feral pigeons was submitted to the Wildlife Diseases Laboratory, Pathology Department, Ontario Veterinary College. A history of neurological signs accompanied most of the birds. Tissues from 29 birds were submitted for PMV-1 isolation. Allantoic inoculation of embryonated chicken eggs yielded PMV-1 in 10 of the pigeons submitted. On the basis of histological criteria, we believe that 12 other birds were also infected with PMV-1. Gross pathological changes were unremarkable. Lymphplasmacytic interstitial nephritis was observed histologically in all birds from which PMV-1 was isolated. Other lesions seen, in decreasing frequency of occurrence, were lymphoplasmacytic interstitial hepatitis and multifocal hepatic necrosis, lymphoplasmacytic interstitial pancreatitis, nonsuppurative encephalitis and myelitis. The existence of PMV-1 in feral pigeons poses a potential threat to the poultry population since there is ample opportunity for mingling with poultry under open housing management. There is also a concern that pigeons may harbor the virus, perhaps in the kidney, and become chronic carriers and potential long-term disseminators of the disease. ImagesFigure 1.Figure 2. PMID:17424132

  14. Self-recognition in pigeons revisited.

    Science.gov (United States)

    Uchino, Emiko; Watanabe, Shigeru

    2014-11-01

    Recognition of a self-image in a mirror is investigated using the mark test during which a mark is placed onto a point on the body that is not directly visible, and the presence or absence of self-directed behaviors is evaluated for the mirror-observing subjects. Great apes, dolphins, possibly elephants, and magpies have all passed the mark test, that is, displayed self-directed behaviors, whereas monkeys, crows, and other animals have failed the test even though they were able to use a mirror to find a not-directly-visible object. Self-directed behavior and mirror use are prerequisites of a successful mark test, and the absence of these behaviors may lead to false negative results. Epstein, Lanza, and Skinner (1981) reported self-directed behavior of pigeons in front of a mirror after explicit training of self-directed pecking and of pecking an object with the aid of a mirror, but certain other researchers could not confirm the results. The aim of the present study was to conduct the mark test with two pigeons that had received extensive training of the prerequisite behaviors. Crucial points of the training were identical topography (pecking) and the same reinforcement (food) in the prerequisite behaviors as well as sufficient training of these behaviors. After training for the prerequisite behaviors, both pigeons spontaneously integrated the learned self-directed and mirror-use behavior and displayed self-directed behavior in a mark test. This indicates that pigeons display mirror self-recognition after training of suitable ontogenetic contingency. © Society for the Experimental Analysis of Behavior.

  15. Ethnobotanic importance of plants used in pigeon-breeding in Eastern Spain.

    Science.gov (United States)

    Belda, Antonio; Cortés, Carolina; Peiró, Victoriano

    2013-05-20

    The importance that birds of the Columbidae family have had throughout history is visible on the Mediterranean coast. Pigeon fancying is the art of breeding and training carrier pigeons and currently, several breeds exist. The sport of racing pigeons consists in covering a distance at maximum possible speed. However, pigeon breeding has another modality called "sport pigeon", where several males follow a female. This study focusses on ethnobotanical knowledge of native and exotic plant species that are used for diet, breeding, stimulation, healing illnesses and staining the plumage of pigeons bred in captivity. Using semi-structured interviews, we gathered information about the different plant species traditionally used for pigeon-breeding in the region of Valencia. Background material on remedies for bird illnesses was gathered from folk botanical references, local books and journals.The plant species were collected in the study area, then identified in the laboratory using dichotomous keys and vouchered in the ABH (Herbarium of Alicante University). We used Excel (®) 2003 to perform a simple statistical analysis of the data collected. We collected 56 species of plants (and one variety) that included 29 botanical families. The total number of species was made up of 35 cultivated and 21 wild plants. The most common were Gramineae (14 species), Leguminosae (6 species), and Compositae (4 species). Pigeon breeding is an immensely popular activity in Eastern Spain, and ethnobiological knowledge about breeding pigeons and caring for them is considerable. The names and traditional uses of plants depend on their geographical location, vernacular names serve as an intangible heritage. Feeding, environmental features, and genetic makeup of individuals are relevant aspects in the maintenance of avian health.

  16. Mortality associated with fenbendazole administration in pigeons (Columba livia).

    Science.gov (United States)

    Gozalo, Alfonso S; Schwiebert, Rebecca S; Lawson, Gregory W

    2006-11-01

    A group of 12 domestic pigeons (Columba livia domestica) was treated for capillariasis by use of fenbendazole at 30 mg/kg orally once daily for 5 d. After treatment, 8 of the 12 pigeons exhibited signs of anorexia, lethargy, and dehydration; these birds died within 2 d after the onset of clinical signs. A total of 6 birds were necropsied, and all had unremarkable gross findings. Microscopic examination of tissues revealed acute hemorrhagic enteritis, diffuse lymphoplasmacytic enteritis, small intestinal crypt necrosis, periportal lymphoplasmacytic hepatitis, bile duct hyperplasia, and renal tubular necrosis. Erythrocytes in blood samples collected from surviving birds demonstrated polychromasia compatible with a regenerative anemia. The clinical and histopathologic findings in these pigeons were consistent with recent reports of fenbendazole toxicity in domestic pigeons and other columbiform birds.

  17. Perception of angle in visual categorization by pigeons (Columba livia.

    Directory of Open Access Journals (Sweden)

    Walter T. Herbranson

    2017-08-01

    Full Text Available Pigeons are capable of learning to categorize stimuli based on visual features, and often reach levels of accuracy comparable with humans. Nevertheless, recent research has suggested that the cognitive processes behind categorization in pigeons and humans may not always be the same. Pigeons learned a categorization task in which they categorized either Shepard circles varying in size and orientation of a radial line (stimuli that are frequently used in research on human categorization, or moving dots varying in speed and direction of travel (stimuli that have been successfully used to study pigeon categorization. Even though categories were balanced so that the angles of orientation of Shepard circles matched the directions of travel for moving dots, birds failed to learn categories based on the former but not the latter. Results suggest that information about angle as a direction of travel may be more important for pigeons than information about angle of orientation.

  18. Endoscopic Vasectomy of Male Feral Pigeons (Columba livia) as a Possible Method of Population Control.

    Science.gov (United States)

    Heiderich, Elisabeth; Schildger, Bernd; Lierz, Michael

    2015-03-01

    To evaluate whether single-entry endoscopic vasectomy of male feral pigeons (Columba livia) significantly reduced fertility and would potentially be valuable for control of feral pigeon populations, 252 male feral pigeons were caught in the city of Berne and endoscopically vasectomized. In this procedure, approximately 1 cm of the deferent duct was removed bilaterally. Rapid, uneventful recoveries occurred in 94% (237/252) of the pigeons, whereas 6% (15/252) died because of complications associated with the procedure, consisting of perforation of the ureter (9/15), major hemorrhage (5/15), and respiratory arrest (1/15). Mean anesthesia time was 23±6 minutes. The vasectomized males were habituated to 2 pigeon houses together with fertile females. Another pigeon house with fertile pairs acted as control. All eggs laid were candled weekly to assess fertility. In the 2 pigeon houses with vasectomized males, the mean fertilization rate was 0.9% (5/563), while in the control pigeon house, the rate was 100% (39/39). The results indicate that endoscopic vasectomy of male feral pigeons may be a promising tool for field control of feral pigeon populations, especially in combination with other methods such as pigeon houses.

  19. NMDA receptors in the avian amygdala and the premotor arcopallium mediate distinct aspects of appetitive extinction learning.

    Science.gov (United States)

    Gao, Meng; Lengersdorf, Daniel; Stüttgen, Maik C; Güntürkün, Onur

    2018-05-02

    Extinction learning is an essential mechanism that enables constant adaptation to ever-changing environmental conditions. The underlying neural circuit is mostly studied with rodent models using auditory cued fear conditioning. In order to uncover the variant and the invariant neural properties of extinction learning, we adopted pigeons as an animal model in an appetitive sign-tracking paradigm. The animals firstly learned to respond to two conditioned stimuli in two different contexts (CS-1 in context A and CS-2 in context B), before conditioned responses to the stimuli were extinguished in the opposite contexts (CS-1 in context B and CS-2 in context A). Subsequently, responding to both stimuli was tested in both contexts. Prior to extinction training, we locally injected the N-methyl-d-aspartate receptor (NMDAR) antagonist 2-Amino-5-phosphonovaleric acid (APV) in either the amygdala or the (pre)motor arcopallium to investigate their involvement in extinction learning. Our findings suggest that the encoding of extinction memory required the activation of amygdala, as visible by an impairment of extinction acquisition by concurrent inactivation of local NMDARs. In contrast, consolidation and subsequent retrieval of extinction memory recruited the (pre)motor arcopallium. Also, the inactivation of arcopallial NMDARs induced a general motoric slowing during extinction training. Thus, our results reveal a double dissociation between arcopallium and amygdala with respect to acquisition and consolidation of extinction, respectively. Our study therefore provides new insights on the two key components of the avian extinction network and their resemblance to the data obtained from mammals, possibly indicating a shared neural mechanism underlying extinction learning shaped by evolution. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. "Good Passengers and Not Good Passengers:" Adolescent Drivers' Perceptions About Inattention and Peer Passengers.

    Science.gov (United States)

    McDonald, Catherine C; Sommers, Marilyn S

    The purpose of this qualitative focus group elicitation research study was to explore teen driver perceptions of peer passengers and driver inattention. We utilized focus groups for data collection and content analysis to analyze the data, both of which were guided by the theory of planned behavior. We conducted 7 focus groups with 30 teens, ages 16-18, licensed for ≤1year to examine attitudes, perceived behavioral control, and norms related to driving inattention and peer passengers. The sample was 50% male, mean age 17.39 (SD 0.52) with mean length of licensure 173.7days (SD 109.2). Three themes emerged: 1) "Good and not good" passengers; 2) Passengers and technology as harmful and helpful; and 3) The driver is in charge. While passengers can be a source of distraction, our participants also identified passenger behaviors that reduced risk, such as assistance with technology and guidance for directions. An understanding of teens' perceptions of peer passengers can contribute to the development of effective interventions targeting teen driver inattention. Nurses are well-positioned to contribute to these teen crash prevention efforts. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Switching hierarchical leadership mechanism in homing flight of pigeon flocks

    Science.gov (United States)

    Chen, Duxin; Vicsek, Tamás; Liu, Xiaolu; Zhou, Tao; Zhang, Hai-Tao

    2016-06-01

    To explore the fascinating inter-individual interaction mechanism governing the abundant biological grouping behaviors, more and more efforts have been devoted to collective motion investigation in recent years. Therein, bird flocking is one of the most intensively studied behaviors. A previous study (Nagy M. et al., Nature, 464 (2010) 890.) claims the existence of a well-defined hierarchical structure in pigeon flocks, which implies that a multi-layer leadership network leads to the occurrence of highly coordinated pigeon flock movements. However, in this study, by using high-resolution GPS data of homing flight of pigeon flocks, we reveal an explicit switching hierarchical mechanism underlying the group motions of pigeons. That is, a pigeon flock has a long-term leader for smooth moving trajectories, whereas the leading tenure passes to a temporary one upon sudden turns or zigzags. Therefore, the present observation helps explore more deeply into the principle of a huge volume of bird flocking dynamics. Meanwhile, from the engineering point of view, it may shed some light onto industrial multi-robot coordination and unmanned air vehicle formation control.

  2. Functional properties of processed pigeon pea ( Cajanus cajan ) flour

    African Journals Online (AJOL)

    Germination increased water absorption capacity, bulk density, oil absorption capacity, foaming capacity, foaming stability, emulsion activity, nitrogen solubility and decreased gelatin and wetability of the pigeon pea flour. Germinated pigeon pea flour has great potentials in food prperations that require hydration to improve ...

  3. Pre-crastination in the pigeon.

    Science.gov (United States)

    Wasserman, Edward A; Brzykcy, Stephen J

    2015-08-01

    Procrastination is the tendency to delay initiating or completing tasks. Rosenbaum et al. (Psychological Science, May 8, 2014) recently documented the opposite of procrastination: pre-crastination, the tendency to begin or to finish tasks as soon as possible. We devised a simple two-alternative forced-choice task, in which pigeons could choose to switch response location either sooner or later in a sequence of actions eventuating in food reward. Even though there was no economic advantage for doing so, pigeons chose to switch response location sooner rather than later in the sequence, showing pre-crastination to be quite general. Pre-crastination thus joins other anticipatory learning phenomena in challenging rational or optimal accounts of behavioral adaptation.

  4. Change detection by rhesus monkeys (Macaca mulatta) and pigeons (Columba livia).

    Science.gov (United States)

    Elmore, L Caitlin; Magnotti, John F; Katz, Jeffrey S; Wright, Anthony A

    2012-08-01

    Two monkeys (Macaca mulatta) learned a color change-detection task where two colored circles (selected from a 4-color set) were presented on a 4 × 4 invisible matrix. Following a delay, the correct response was to touch the changed colored circle. The monkeys' learning, color transfer, and delay transfer were compared to a similar experiment with pigeons. Monkeys, like pigeons (Columba livia), showed full transfer to four novel colors, and to delays as long as 6.4 s, suggesting they remembered the colors as opposed to perceptual based attentional capture process that may work at very short delays. The monkeys and pigeons were further tested to compare transfer with other dimensions. Monkeys transferred to shape and location changes, unlike the pigeons, but neither species transferred to size changes. Thus, monkeys were less restricted in their domain to detect change than pigeons, but both species learned the basic task and appear suitable for comparative studies of visual short-term memory. 2012 APA, all rights reserved

  5. Coding in pigeons: Multiple-coding versus single-code/default strategies.

    Science.gov (United States)

    Pinto, Carlos; Machado, Armando

    2015-05-01

    To investigate the coding strategies that pigeons may use in a temporal discrimination tasks, pigeons were trained on a matching-to-sample procedure with three sample durations (2s, 6s and 18s) and two comparisons (red and green hues). One comparison was correct following 2-s samples and the other was correct following both 6-s and 18-s samples. Tests were then run to contrast the predictions of two hypotheses concerning the pigeons' coding strategies, the multiple-coding and the single-code/default. According to the multiple-coding hypothesis, three response rules are acquired, one for each sample. According to the single-code/default hypothesis, only two response rules are acquired, one for the 2-s sample and a "default" rule for any other duration. In retention interval tests, pigeons preferred the "default" key, a result predicted by the single-code/default hypothesis. In no-sample tests, pigeons preferred the key associated with the 2-s sample, a result predicted by multiple-coding. Finally, in generalization tests, when the sample duration equaled 3.5s, the geometric mean of 2s and 6s, pigeons preferred the key associated with the 6-s and 18-s samples, a result predicted by the single-code/default hypothesis. The pattern of results suggests the need for models that take into account multiple sources of stimulus control. © Society for the Experimental Analysis of Behavior.

  6. Endpoint Distinctiveness Facilitates Analogical Mapping in Pigeons

    Science.gov (United States)

    Hagmann, Carl Erick; Cook, Robert G.

    2015-01-01

    Analogical thinking necessitates mapping shared relations across two separate domains. We investigated whether pigeons could learn faster with ordinal mapping of relations across two physical dimensions (circle size & choice spatial position) relative to random mapping of these relations. Pigeons were trained to relate six circular samples of different sizes to horizontally positioned choice locations in a six alternative matching-to-sample task. Three pigeons were trained in a mapped condition in which circle size mapped directly onto choice spatial position. Three other pigeons were trained in a random condition in which the relations between size and choice position were arbitrarily assigned. The mapped group showed an advantage over the random group in acquiring this task. In a subsequent second phase, reassignment, relations between the dimensions were ordinally reversed for the mapped group and re-randomized for the random group. There was no difference in how quickly matching accuracy re-emerged in the two groups, although the mapped group eventually performed more accurately. Analyses suggested this mapped advantage was likely due endpoint distinctiveness and the benefits of proximity errors during choice responding rather than a conceptual or relational advantage attributable to the common or ordinal map of the two dimensions. This potential difficulty in mapping relations across dimensions may limit the pigeons’ capacity for more advanced types of analogical reasoning. PMID:25447511

  7. Effect of Haemoproteus columbae infection on the hemogram of the Pigeons (Columba livia domestica).

    Science.gov (United States)

    Samani, Amir Dehghani; Kheirabadi, Khodadad Pirali; Mohebbi, Abdonnaser

    2016-12-01

    It has been reported that parasites affect the health and productivity of birds, initiate excessive preening which interrupts feeding, as the birds spend much time preening rather than being involved in other essential life activities. Haemoproteus columbae occurs in pigeons widely in tropical and subtropical regions. The present investigation was concentrated on the effect of H. columbae infection on the hemogram and changes in the number of white blood cells in infected pigeons. Blood samples taked from 100 pigeons in Shahrekord. Blood smears stained and observed for H. columbae infection. Packed cell volume (PCV) and total white blood cells (WBC) count and differential WBC count determinate for every smears. This study show that PCV increased in infected pigeons by H. columbae than non infected pigeons. There were increasing in the number of total WBC in the infected pigeons by H. columbae than non infected pigeons. Also there were significant differences between the number of lymphocytes and eosinophils in the infected pigeons by H. columbae than non infected pigeons. This study and same studies show the part of the effects of blood parasites on the hemogram, but there were many questions about the effects of blood parasites such as H. columbae on the other parameters of host's blood, so we advise to focus on the other hematological parameters in the future studies.

  8. The complete mitochondrial genome of the Fancy Pigeon, Columba livia (Columbiformes: Columbidae).

    Science.gov (United States)

    Zhang, Rui-Hua; Xu, Ming-Ju; Wang, Cun-Lian; Xu, Tong; Wei, Dong; Liu, Bao-Jian; Wang, Guo-Hua

    2015-02-01

    The fancy pigeons are domesticated varieties of the rock pigeon developed over many years of selective breeding. In the present work, we report the complete mitochondrial genome sequence of fancy pigeon for the first time. The total length of the mitogenome was 17,233 bp with the base composition of 30.1% for A, 24.0% for T, 31.9% for C, and 14.0% for G and an A-T (54.2 %)-rich feature was detected. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region (D-loop region). The arrangement of all genes was identical to the typical mitochondrial genomes of pigeon. The complete mitochondrial genome sequence of fancy pigeon would serve as an important data set of the germplasm resources for further study.

  9. The complete mitochondrial genome of the ice pigeon (Columba livia breed ice).

    Science.gov (United States)

    Zhang, Rui-Hua; He, Wen-Xiao

    2015-02-01

    The ice pigeon is a breed of fancy pigeon developed over many years of selective breeding. In the present work, we report the complete mitochondrial genome sequence of ice pigeon for the first time. The total length of the mitogenome was 17,236 bp with the base composition of 30.2% for A, 24.0% for T, 31.9% for C, and 13.9% for G and an A-T (54.2 %)-rich feature was detected. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region (D-loop region). The arrangement of all genes was identical to the typical mitochondrial genomes of pigeon. The complete mitochondrial genome sequence of ice pigeon would serve as an important data set of the germplasm resources for further study.

  10. Physicochemical and sensory characteristics of soy sauce substituted with pigeon pea (Cajanus cajan (Linn.))

    Science.gov (United States)

    Retnaningsih, C.; Sumardi; Meiliana; Surya, A.

    2018-01-01

    The objective of this study wasto investigate the physicochemical and sensory properties of the soy sauce substituted with pigeon pea. Soybean was substituted by 20%, 50%, 75%, and 100% of pigeon pea. The observation included viscosity, total solids, protein levels, antioxidant activity, and sensory characteristics. The results showed that the more substitution of pigeon pea, the less the protein content of soy sauce and the more the antioxidant activity as well as total solids. The most favored group was 25% pigeon pea substitution. It is suggested that soy sauce could be prepared using 25% to 75% pigeon pea substitution.

  11. CLINICO-PATHOLOGICAL OBSERVATIONS OF PIGEONS (COLUMBA LIVIA SUFFERING FROM NEWCASTLE DISEASE

    Directory of Open Access Journals (Sweden)

    S. Shaheen, A. D. Anjum and F. Rizvi

    2005-01-01

    Full Text Available A survey was conducted to study clinical signs, gross and histopathological lesions in pigeons with naturally occurring Newcastle disease. For this purpose, 30 pigeon lofts were visited. Among these, 14 lofts showed clinical signs of Newcastle disease, including mainly greenish white mucoid diarrhoea and nervous signs with high morbidity and mortality. Postmortem examination of affected birds showed lesions mainly in brain, liver, kidneys and spleen. Amongst various organs, kidneys were more frequently involved. Histopathological changes were also observed in lungs, liver, kidneys, brain and spleen. The results showed that the Newcastle disease virus was widespread in pigeons locally and caused heavy mortality. No preventive measures or vaccination is being adopted by pigeon fanciers to control the disease.

  12. Mycoplasma columbinum Isolated From a Racing Pigeon ( Columba livia ) With Arthritis.

    Science.gov (United States)

    Hellebuyck, Tom; Garmyn, An; De Cooman, Lien; Boyen, Filip; Pasmans, Frank; Martel, An

    2014-09-01

    A juvenile racing pigeon ( Columba livia ) was presented with drooping of the wing and inability to fly. On physical examination, the right shoulder joint was swollen. The pigeon was euthanatized and submitted for necropsy. An excessive amount of fibrin was present in the canalis triosseus with severe arthritis of the affected shoulder joint. A pure growth of Mycoplasma-like colonies was obtained on microbiological culture of the shoulder joint. A 16S ribosomal RNA gene-specific polymerase chain reaction assay was performed on the isolate and revealed 100% similarity with Mycoplasma columbinum . Although infectious arthritis in homing pigeons is primarily associated with paratyphoid and Streptococcus gallolyticus infection, clinical practitioners should consider the potential role of Mycoplasma columbinum in arthritis in pigeons.

  13. Effect of Hygromycin-B on pigeons (Columba livia) with and without Trichomonas gallinae

    Science.gov (United States)

    Kocan, R.M.

    1972-01-01

    Hygromycin-B was administered in varied quantities to pigeons harboring nonvirulent Trichomonas gallinae and to pigeons free of T. gallinae. Both groups responded identically with large yellow caseous lesions in the upper digestive tract which superficially resembled canker (trichomoniasis). No mycotic association with the lesions could be established in either .group from sections stained with periodic acid-Schiff. The lesions observed in Hygromycin-B-treated pigeons were concluded to be the direct result of the drug on the mucosa of the pigeon's upper digestive tract.

  14. Petrographic Analysis and Geochemical Source Correlation of Pigeon Peak, Sutter Buttes, CA

    Science.gov (United States)

    Novotny, N. M.; Hausback, B. P.

    2013-12-01

    The Sutter Buttes are a volcanic complex located in the center of the Great Valley north of Sacramento. They are comprised of numerous inter-intruding andesite and rhyolite lava domes of varying compositions surrounded by a shallow rampart of associated tephras. The Pigeon Peak block-and-ash flow sequence is located in the rampart and made up of a porphyritic Biotite bearing Hornblende Andesite. The andesite blocks demonstrate a high degree of propylization in hornblende crystals, highly zoned plagioclase, trace olivine, and display a red to gray color gradation. DAR is an andesite dome located less than one mile from Pigeon Peak. Of the 15 to 25 andesite lava domes within four miles from Pigeon Peak, only DAR displays trace olivine, red to grey color stratification, low biotite content, and propylitized hornblende. These characteristic similarities suggest that DAR may be the source for Pigeon Peak. My investigation used microprobe analysis of the DAR and Pigeon Peak feldspar crystals to identify the magmatic history of the magma body before emplacement. Correlation of the anorthite zoning within the feldspars from both locations support my hypothesis that DAR is the source of the Pigeon Peak block-and-ash flow.

  15. Species-specific response-topography of chickens' and pigeons' water-induced autoshaped responding.

    Science.gov (United States)

    Ploog, Bertram O

    2014-07-01

    Four pigeons and eight chickens received autoshaping training where a keylight (conditioned stimulus) signaled response-independent deliveries of water (unconditioned stimulus). Pigeons drink while keeping their beaks submerged in water and moving their beaks to create suction ("mumbling"), whereas chickens drink by trapping a small amount of water in their mouths and then lifting their heads so the water trickles down. This experiment tested whether these and other species-specific differences in drinking and related behaviors of pigeons and chickens would be reflected in the form of conditioned (autoshaped) responding. Touchscreens and videotapes were used for data recording. Results showed that chickens moved their heads more than pigeons when drinking (unconditioned response). The birds also differed in conditioned responding in the presence of the keylight: Pigeons produced more keyswitch closures and mumbled at the keylight more than chickens whereas chickens scratched more than pigeons. In conclusion, with this unique comparative method that employed identical contingencies and comparable deprivation levels, species-specific differences in unconditioned responses and, more importantly, differences in their corresponding conditioned responses were observed. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Acute prurigo simplex in humans caused by pigeon lice.

    Science.gov (United States)

    Stolf, Hamilton Ometto; Reis, Rejane d'Ávila; Espósito, Ana Cláudia Cavalcante; Haddad Júnior, Vidal

    2018-03-01

    Pigeon lice are insects that feed on feathers of these birds; their life cycle includes egg, nymph and adult and they may cause dermatoses in humans. Four persons of the same family, living in an urban area, presented with widespread intensely pruritic erythematous papules. A great number of lice were seen in their house, which moved from a nest of pigeons located on the condenser of the air-conditioning to the dormitory of one of the patients. Even in urban environments, dermatitis caused by parasites of birds is a possibility in cases of acute prurigo simplex. Pigeon lice are possible etiological agents of this kind of skin eruption, although they are often neglected, even by dermatologists.

  17. “Good passengers and not good passengers:” Adolescent drivers’ perceptions about inattention and peer passengers

    Science.gov (United States)

    Sommers, Marilyn S.

    2016-01-01

    Purpose The purpose of this qualitative focus group elicitation research study was to explore teen driver perceptions of peer passengers and driver inattention. Design & Methods We utilized focus groups for data collection and content analysis to analyze the data, both of which were guided by the Theory of Planned Behavior. We conducted 7 focus groups with 30 teens, ages 16–18, licensed for ≤1 year to examine attitudes, perceived behavioral control, and norms related to driving inattention and peer passengers. Results The sample was 50% male, mean age 17.39 (sd 0.52) with mean length of licensure 173.7 days (sd 109.2). Three themes emerged: 1) “Good and not good” passengers; 2) Passengers and technology as harmful and helpful; and 3) The driver is in charge. Conclusions While passengers can be a source of distraction, our participants also identified passenger behaviors that reduced risk, such as assistance with technology and guidance for directions. Practical Implications An understanding of teens’ perceptions of peer passengers can contribute to the development of effective interventions targeting teen driver inattention. Nurses are well-positioned to contribute to these teen crash prevention efforts. PMID:27496828

  18. Germinated Pigeon Pea (Cajanus cajan): a novel diet for lowering oxidative stress and hyperglycemia.

    Science.gov (United States)

    Uchegbu, Nneka N; Ishiwu, Charles N

    2016-09-01

    This work studied the antioxidant activity of extract of germinated pigeon pea (Cajanus cajan) in alloxan-induced diabetic rats. Germination was carried out in a dark chamber under room temperature (28°C). The total phenolic, 1,1,diphenyl-2-picrylhy-drazyl free radical (DPPH) scavenging, the inhibition of α-amylase and α-glucosidase were done in vitro and blood glucose levels of the animal were investigated. Lipid peroxidation (LPO) and reduced glutathione (GSH) were analyzed spectrophotometrically. The total phenolic and DPPH scavenging activity increased by 30% and 63%, respectively, after germinating pigeon pea. Also after germination there was an increase in the inhibitory potential of pigeon pea extract against α-glucosidase compared with the nongerminated pigeon pea extract. There was a significant increase (P pigeon pea extract gave rise to a reduced fasting blood glucose level in diabetic rats. On administration of germinated pigeon pea extract, LPO reduced drastically but there was an increase in the level of GSH. This study concluded that intake of germinated pigeon pea is a good dietary supplement for controlling hyperglycemia and LPO.

  19. An evaluation of the impact of aloe vera and licorice extracts on the course of experimental pigeon paramyxovirus type 1 infection in pigeons.

    Science.gov (United States)

    Dziewulska, D; Stenzel, T; Smialek, M; Tykalowski, B; Koncicki, A

    2018-02-01

    The progressive decrease in the efficiency of synthetic drugs has prompted research into phytogenic feed additives with potentially immunomodulatory and anti-infective properties. Complex diseases with a mixed etiology, including viral, pose a growing problem in domestic pigeons. The aim of this study was to determine the effectiveness of various doses of aloe vera and licorice extracts on the course of experimental PPMV-1 infection in pigeons. The experiment was performed on pigeons divided into 5 groups, including one control group and 4 experimental groups, which were orally administered aloe vera or licorice extracts at 300 or 500 mg/kg BW for 7 d after experimental inoculation with PPMV-1. On d 4, 7, and 14 after inoculation, cloacal swabs and samples of organs were collected from 4 birds in each group. The samples were analyzed to determine the copy number of PPMV-1 RNA by TaqMan qPCR. The results indicate that licorice and aloe vera extracts inhibited PPMV-1 replication by decreasing viral RNA copy numbers in the examined organs. The most inhibitory effect was observed in pigeons receiving aloe vera extract at 300 mg/kg BW, for which PPMV-1 RNA copy numbers were approximately 7-fold lower (brain), 9-fold lower (kidneys), and 14-fold lower (liver) than in the control group. The results of this study point to the potentially antiviral effects of aloe vera and licorice extracts in pigeons infected with PPMV-1. To the best of our knowledge, this is the first study to investigate the antiviral properties of aloe vera and licorice extracts in domestic pigeons. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.

  20. Altered orientation and flight paths of pigeons reared on gravity anomalies: a GPS tracking study.

    Directory of Open Access Journals (Sweden)

    Nicole Blaser

    Full Text Available The mechanisms of pigeon homing are still not understood, in particular how they determine their position at unfamiliar locations. The "gravity vector" theory holds that pigeons memorize the gravity vector at their home loft and deduct home direction and distance from the angular difference between memorized and actual gravity vector. However, the gravity vector is tilted by different densities in the earth crust leading to gravity anomalies. We predicted that pigeons reared on different gravity anomalies would show different initial orientation and also show changes in their flight path when crossing a gravity anomaly. We reared one group of pigeons in a strong gravity anomaly with a north-to-south gravity gradient, and the other group of pigeons in a normal area but on a spot with a strong local anomaly with a west-to-east gravity gradient. After training over shorter distances, pigeons were released from a gravitationally and geomagnetically normal site 50 km north in the same direction for both home lofts. As expected by the theory, the two groups of pigeons showed divergent initial orientation. In addition, some of the GPS-tracked pigeons also showed changes in their flight paths when crossing gravity anomalies. We conclude that even small local gravity anomalies at the birth place of pigeons may have the potential to bias the map sense of pigeons, while reactivity to gravity gradients during flight was variable and appeared to depend on individual navigational strategies and frequency of position updates.

  1. Scale-dependent associations of Band-tailed Pigeon counts at mineral sites

    Science.gov (United States)

    Overton, Cory T.; Casazza, Michael L.; Coates, Peter S.

    2010-01-01

    The abundance of Band-tailed Pigeons (Patagioenas fasciata monilis) has declined substantially from historic numbers along the Pacific Coast. Identification of patterns and causative factors of this decline are hampered because habitat use data are limited, and temporal and spatial variability patterns associated with population indices are not known. Furthermore, counts are influenced not only by pigeon abundance but also by rate of visitation to mineral sites, which may not be consistent. To address these issues, we conducted mineral site counts during 2001 and 2002 at 20 locations from 4 regions in the Pacific Northwest, including central Oregon and western Washington, USA, and British Columbia, Canada. We developed inference models that consisted of environmental factors and spatial characteristics at multiple spatial scales. Based on information theory, we compared models within a final set that included variables measured at 3 spatial scales (0.03 ha, 3.14 ha, and 7850 ha). Pigeon counts increased from central Oregon through northern Oregon and decreased into British Columbia. After accounting for this spatial pattern, we found that pigeon counts increased 12% ± 2.7 with a 10% increase in the amount of deciduous forested area within 100 m from a mineral site. Also, distance from the mineral site of interest to the nearest known mineral site was positively related to pigeon counts. These findings provide direction for future research focusing on understanding the relationships between indices of relative abundance and complete counts (censuses) of pigeon populations by identifying habitat characteristics that might influence visitation rates. Furthermore, our results suggest that spatial arrangement of mineral sites influences Band-tailed Pigeon counts and the populations which those counts represent.

  2. Coccidiosis of domestic pigeons (Columba livia domestica Gmelin, 1789) in Kano State, Nigeria

    Science.gov (United States)

    Mohammed, Balarabe R; Simon, Malang K; Agbede, Rowland IS; Arzai, Auwalu H

    Pigeon coccidiosis is caused by Eimeria spp., a protozoan parasite which limits productivity by causing severe illness. Although numerous studies have been conducted on the coccidiosis of pigeons in some parts of Nigeria, there is no published data from Kano State. The intestinal contents of 144 pigeons (72 females and 72 males) were analysed for Eimeria oocysts in 2007 from 12 Local Government Areas of Kano State over the period of six months including the dry (February–April) and wet (June–August) seasons. The pigeons were divided into three groups according to age: squabs (0–4 weeks), squeakers (5–8 weeks) and youngsters (9+ weeks); each group including 48 pigeons. The results of these studies revealed an overall prevalence of 19.44%. The prevalence was higher in females (20.83%) than males (18.06%) (p<0.05). Furthermore, squabs had the highest prevalence (27.08%) followed by squeakers (20.83%), and youngsters (10.42%) (p<0.05). Infection with Eimeria spp. oocysts was higher during the wet season (8.96%) than dry season (5.98%) (p<0.05). This study provides basic information on the first detection of coccidiosis of pigeons in Kano State, Nigeria which has an implication on the sustainable pigeon production for human protein reguirement.

  3. Prevalence of virulence factors in Staphylococcus intermedius isolates from dogs and pigeons

    Directory of Open Access Journals (Sweden)

    Fukuyasu Tsuguaki

    2006-01-01

    Full Text Available Abstract Background Staphylococcus intermedius has been isolated from healthy dogs and pigeons as well as diseased dogs. Similar to Staphylococcus aureus, S. intermedius is known to carry many virulence factors but most of these factors remain to be studied. In this study, we examined 106 S. intermedius isolates (44 dog isolates and 62 pigeon isolates for their hemolytic activity, biofilm formation, protease activity, and clumping factor and protein A production. Results Forty-three dog isolates (97.7% and all pigeon isolates were hemolytic on sheep RBCs with a mean hemolytic titer of 336.7 and 47.32, respectively, whereas 43 dog isolates (97.7% and 11 pigeon isolates (17.7% exhibited a significant difference in their hemolytic activity on rabbit RBCs with a mean hemolytic titer of 11.04 and 3.76, respectively (p Conclusion S. intermedius strains carrying the virulence factors examined in this study were more prevalent in dogs than pigeons.

  4. Dietary habits of urban pigeons (Columba livia and implications of excreta pH – a review

    Directory of Open Access Journals (Sweden)

    Spennemann Dirk H. R.

    2017-03-01

    Full Text Available Pigeons are considered to be urban pests, causing untold damage to buildings and potentially impacting the health of humans who come into contact with them or their faeces. Pigeon faecal matter has been implicated in both health impacts and building damage, with the acidity of the excreta playing an important role. Purpose of the Review. This paper is a wide-ranging review of the chemical processes of excreta in the pigeon to aid our understanding of the potential problems of pigeons to buildings and human amenity in the urban space. The natural pH of pigeons is shown to vary based on the bird’s and age as well as reproductive stage. Key findings of the review. The influences of the altered diet between the rock dove (the wild progenitor of the feral pigeon and the feral pigeon are detailed, indicating that the human-based diet of urban pigeons most likely causes the feral pigeon excreta to be more acidic than the rock dove excreta. This higher acidity is due in part to diet, but also to potential increases in faecal and/or uric acid volumes due to the low quality of human-based diets. Again, this area of interest is highly data deficient due to the few number of studies and unspecified dietary intake before pH measurement. Implications of the review. Humans are increasingly concerned about pigeon populations (and presumably their accumulated faeces in the urban space, and control comprises a large part of the interaction between humans and feral pigeons. This review provides a greater understanding of feral pigeons and the true effects of their excreta.

  5. Substitution Value of toasted Pigeon pea ( Cajanus cajan ) seed ...

    African Journals Online (AJOL)

    One hundred and eighty 7-day old broilers were used in a 28-day feeding trial to determine the substitution value of toasted pigeon pea seeds meal (TPSM) for soybean meal and maize in boiler starter diet. The brown coat coloured pigeon pea seeds were toasted at 100oC for 15minutes and milled. The inclusion levels of ...

  6. The Impact of Deoxynivalenol on Pigeon Health: Occurrence in Feed, Toxicokinetics and Interaction with Salmonellosis.

    Science.gov (United States)

    Antonissen, Gunther; Haesendonck, Roel; Devreese, Mathias; Broekaert, Nathan; Verbrugghe, Elin; De Saeger, Sarah; Audenaert, Kris; Haesebrouck, Freddy; Pasmans, Frank; Ducatelle, Richard; Croubels, Siska; Martel, An

    2016-01-01

    Seed-based pigeon diets could be expected to result in exposure of pigeons to mycotoxins such as deoxynivalenol (DON). Ingestion of low to moderate contamination levels of DON may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host-pathogen interactions and thus different outcome of infections. Here we demonstrate that DON was one of the most frequently detected mycotoxins in seed-based racing pigeons feed, contaminating 5 out of 10 samples (range 177-1,466 μg/kg). Subsequently, a toxicokinetic analysis revealed a low absolute oral bioavailability (F) of DON in pigeons (30.4%), which is comparable to other avian species. Furthermore, semi-quantitative analysis using high-resolution mass spectrometry revealed that DON-3α-sulphate is the major metabolite of DON in pigeons after intravenous as well as oral administration. Following ingestion of DON contaminated feed, the intestinal epithelial cells are exposed to significant DON concentrations which eventually may affect intestinal translocation and colonization of bacteria. Feeding pigeons a DON contaminated diet resulted in an increased percentage of pigeons shedding Salmonella compared to birds fed control diet, 87 ± 17% versus 74 ± 13%, respectively. However, no impact of DON was observed on the Salmonella induced disease signs, organ lesions, faecal and organ Salmonella counts. The presented risk assessment indicates that pigeons are frequently exposed to mycotoxins such as DON, which can affect the outcome of a Salmonella infection. The increasing number of pigeons shedding Salmonella suggests that DON can promote the spread of the bacterium within pigeon populations.

  7. The Impact of Deoxynivalenol on Pigeon Health: Occurrence in Feed, Toxicokinetics and Interaction with Salmonellosis.

    Directory of Open Access Journals (Sweden)

    Gunther Antonissen

    Full Text Available Seed-based pigeon diets could be expected to result in exposure of pigeons to mycotoxins such as deoxynivalenol (DON. Ingestion of low to moderate contamination levels of DON may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host-pathogen interactions and thus different outcome of infections. Here we demonstrate that DON was one of the most frequently detected mycotoxins in seed-based racing pigeons feed, contaminating 5 out of 10 samples (range 177-1,466 μg/kg. Subsequently, a toxicokinetic analysis revealed a low absolute oral bioavailability (F of DON in pigeons (30.4%, which is comparable to other avian species. Furthermore, semi-quantitative analysis using high-resolution mass spectrometry revealed that DON-3α-sulphate is the major metabolite of DON in pigeons after intravenous as well as oral administration. Following ingestion of DON contaminated feed, the intestinal epithelial cells are exposed to significant DON concentrations which eventually may affect intestinal translocation and colonization of bacteria. Feeding pigeons a DON contaminated diet resulted in an increased percentage of pigeons shedding Salmonella compared to birds fed control diet, 87 ± 17% versus 74 ± 13%, respectively. However, no impact of DON was observed on the Salmonella induced disease signs, organ lesions, faecal and organ Salmonella counts. The presented risk assessment indicates that pigeons are frequently exposed to mycotoxins such as DON, which can affect the outcome of a Salmonella infection. The increasing number of pigeons shedding Salmonella suggests that DON can promote the spread of the bacterium within pigeon populations.

  8. First description of Cryptosporidium parvum in carrier pigeons (Columba livia).

    Science.gov (United States)

    Oliveira, Bruno César Miranda; Ferrari, Elis Domingos; da Cruz Panegossi, Mariele Fernanda; Nakamura, Alex Akira; Corbucci, Flávio Sader; Nagata, Walter Bertequini; Dos Santos, Bianca Martins; Gomes, Jancarlo Ferreira; Meireles, Marcelo Vasconcelos; Widmer, Giovanni; Bresciani, Katia Denise Saraiva

    2017-08-30

    The carrier pigeon and the domestic pigeon are different breeds of the species Columba livia. Carrier pigeons are used for recreational activities such as bird contests and exhibitions. Due to the close contact with humans, these birds may potentially represent a public health risk, since they can host and disseminate zoonotic parasites, such as those belonging to the genus Cryptosporidium (phylum Apicomplexa). The purpose of this work was the detection by microscopic and molecular techniques of Cryptosporidium spp. oocysts in fecal samples of carrier pigeons, and subsequently to sequence the 18S ribosomal RNA marker of positive samples to identify the species. A total of 100 fecal samples were collected individually in two pigeon breeding facilities from Formiga and Araçatuba, cities located in Minas Gerais state and São Paulo state, Brazil, respectively. The age of the birds ranged from one to 12 years; 56 were females and 44 males. Fecal smears were stained with negative malachite green, whereas the molecular characterization was based on the sequence of a ∼800bp fragment of the 18S rRNA gene. Microscopic examination of fecal smears revealed 4% (4/100) oocyst positivity. On the other hand, 7% (7/100) of positivity were found using nested PCR. Three samples were 99% to 100% similar to Cryptosporidium parvum 18S rDNA type A (Genbank AH006572) and the other three samples had 99% to 100% similarity to C. parvum 18S rDNA type B (Genbank AF308600). To our knowledge, this is the first report of C. parvum oocysts in carrier pigeons. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Echoic memory in pigeons

    NARCIS (Netherlands)

    Kretzschmar, C.; Kalenscher, T.; Güntürkün, O.; Kaernbach, C.

    2008-01-01

    It is unknown whether birds are able to retain the memory of purely sensory auditory information such as white noise over an extended period of time. In a Pavlovian heart rate conditioning paradigm, four pigeons were trained to associate a mild electric shock with periodic random waveforms, and no

  10. Putative adult neurogenesis in two domestic pigeon breeds (Columba livia domestica): racing homer versus utility carneau pigeons.

    Science.gov (United States)

    Mazengenya, Pedzisai; Bhagwandin, Adhil; Nkomozepi, Pilani; Manger, Paul R; Ihunwo, Amadi O

    2017-07-01

    Generation of neurons in the brains of adult birds has been studied extensively in the telencephalon of song birds and few studies are reported on the distribution of PCNA and DCX in the telencephalon of adult non-song learning birds. We report here on adult neurogenesis throughout the brains of two breeds of adult domestic pigeons (Columba livia domestica), the racing homer and utility carneau using endogenous immunohistochemical markers proliferating cell nuclear antigen (PCNA) for proliferating cells and doublecortin (DCX) for immature and migrating neurons. The distribution of PCNA and DCX immunoreactivity was very similar in both pigeon breeds with only a few minor differences. In both pigeons, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, walls of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and cerebellum. Generally, the olfactory bulbs and telencephalon had more PCNA and DCX cells than other regions. Two proliferative hotspots were evident in the dorsal and ventral poles of the lateral ventricles. PCNA- and DCX-immunoreactive cells migrated radially from the walls of the lateral ventricle into the parenchyma. In most telencephalic regions, the density of PCNA- and DCX-immunoreactive cells increased from rostral to caudal, except in the mesopallium where the density decreased from rostral to middle levels and then increased caudally. DCX immunoreactivity was more intense in fibres than in cell bodies and DCX-immunoreactive cells included small granular cells, fusiform bipolar cells, large round and or polygonal multipolar cells. The similarity in the distribution of proliferating cells and new neurons in the telencephalon of the two breeds of pigeons may suggest that adult neurogenesis is a conserved trait as an ecological adaptation irrespective of body size.

  11. Putative adult neurogenesis in two domestic pigeon breeds (Columba livia domestica: racing homer versus utility carneau pigeons

    Directory of Open Access Journals (Sweden)

    Pedzisai Mazengenya

    2017-01-01

    Full Text Available Generation of neurons in the brains of adult birds has been studied extensively in the telencephalon of song birds and few studies are reported on the distribution of PCNA and DCX in the telencephalon of adult non-song learning birds. We report here on adult neurogenesis throughout the brains of two breeds of adult domestic pigeons (Columba livia domestica, the racing homer and utility carneau using endogenous immunohistochemical markers proliferating cell nuclear antigen (PCNA for proliferating cells and doublecortin (DCX for immature and migrating neurons. The distribution of PCNA and DCX immunoreactivity was very similar in both pigeon breeds with only a few minor differences. In both pigeons, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, walls of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and cerebellum. Generally, the olfactory bulbs and telencephalon had more PCNA and DCX cells than other regions. Two proliferative hotspots were evident in the dorsal and ventral poles of the lateral ventricles. PCNA- and DCX-immunoreactive cells migrated radially from the walls of the lateral ventricle into the parenchyma. In most telencephalic regions, the density of PCNA- and DCX-immunoreactive cells increased from rostral to caudal, except in the mesopallium where the density decreased from rostral to middle levels and then increased caudally. DCX immunoreactivity was more intense in fibres than in cell bodies and DCX-immunoreactive cells included small granular cells, fusiform bipolar cells, large round and or polygonal multipolar cells. The similarity in the distribution of proliferating cells and new neurons in the telencephalon of the two breeds of pigeons may suggest that adult neurogenesis is a conserved trait as an ecological adaptation irrespective of body size.

  12. Pigeon interaction mode switch-based UAV distributed flocking control under obstacle environments.

    Science.gov (United States)

    Qiu, Huaxin; Duan, Haibin

    2017-11-01

    Unmanned aerial vehicle (UAV) flocking control is a serious and challenging problem due to local interactions and changing environments. In this paper, a pigeon flocking model and a pigeon coordinated obstacle-avoiding model are proposed based on a behavior that pigeon flocks will switch between hierarchical and egalitarian interaction mode at different flight phases. Owning to the similarity between bird flocks and UAV swarms in essence, a distributed flocking control algorithm based on the proposed pigeon flocking and coordinated obstacle-avoiding models is designed to coordinate a heterogeneous UAV swarm to fly though obstacle environments with few informed individuals. The comparative simulation results are elaborated to show the feasibility, validity and superiority of our proposed algorithm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Metal concentrations in homing pigeon lung tissue as a biomonitor of atmospheric pollution.

    Science.gov (United States)

    Cui, Jia; Halbrook, Richard S; Zang, Shuying; Han, Shuang; Li, Xinyu

    2018-03-01

    Atmospheric pollution in urban areas is a major worldwide concern with potential adverse impacts on wildlife and humans. Biomonitoring can provide direct evidence of the bioavailability and bioaccumulation of toxic metals in the environment that is not available with mechanical air monitoring. The current study continues our evaluation of the usefulness of homing pigeon lung tissue as a biomonitor of atmospheric pollution. Homing pigeons (1-2, 5-6, and 9-10+ year old (yo)) collected from Guangzhou during 2015 were necropsied and concentrations of cadmium (Cd), lead (Pb), and mercury (Hg) were measured in lung tissue. Lung Cd and Pb concentrations were significantly greater in 9-10+-year-old pigeons compared with those in other age groups, indicating their bioavailability and bioaccumulation. Lung Pb and Cd concentrations measured in 5-yo pigeons collected from Guangzhou during 2015 were significantly lower than concentrations reported in 5-yo homing pigeons collected from Guangzhou during 2011 and correlated with concentrations measured using mechanical air monitoring. In addition to temporal differences, spatial differences in concentrations of Cd, Pb, and Hg reported in ambient air samples and in pigeon lung tissues collected from Beijing and Guangzhou are discussed.

  14. Pigeons (Columba livia) show change blindness in a color-change detection task.

    Science.gov (United States)

    Herbranson, Walter T; Jeffers, Jacob S

    2017-07-01

    Change blindness is a phenomenon whereby changes to a stimulus are more likely go unnoticed under certain circumstances. Pigeons learned a change detection task, in which they observed sequential stimulus displays consisting of individual colors back-projected onto three response keys. The color of one response key changed during each sequence and pecks to the key that displayed the change were reinforced. Pigeons showed a change blindness effect, in that change detection accuracy was worse when there was an inter-stimulus interval interrupting the transition between consecutive stimulus displays. Birds successfully transferred to stimulus displays involving novel colors, indicating that pigeons learned a general change detection rule. Furthermore, analysis of responses to specific color combinations showed that pigeons could detect changes involving both spectral and non-spectral colors and that accuracy was better for changes involving greater differences in wavelength. These results build upon previous investigations of change blindness in both humans and pigeons and suggest that change blindness may be a general consequence of selective visual attention relevant to multiple species and stimulus dimensions.

  15. Effective management of pigeon pea ( Cajanus cajan ) in a crop ...

    African Journals Online (AJOL)

    Effective management of pigeon pea ( Cajanus cajan ) in a crop/livestock integrated farming system in northern Ghana. ... Ghana Journal of Agricultural Science ... Pigeon pea plots with row lengths averaging 11 m and a planting geometry of 80 cm W 50 cm, were either pruned at 60 or 100 cm above ground level or not ...

  16. A pigeon crop sac radioreceptor assay for prolactin

    International Nuclear Information System (INIS)

    Forsyth, I.A.; Buntin, J.D.; Nicoll, C.S.

    1978-01-01

    Ovine prolactin, labelled with 125 I by either lactoperoxidase or a mild chloramine T method, was bound to receptors from the pigeon crop sac mucosa cells of prolactin-injected pigeons. Binding was demonstrated in a crude homogenate of mucosal cells removed from the crop by scraping and in a subcellular fraction in which 5'- nucleotidase activity was enhanced two- to three-fold. The binding was specific, dependent on time, temperature and the concentration of receptors and had a dissociation constant of 7 x 10 -10 mol/l. The binding capacity of the crop tissue was 71 fmol/mg membrane protein. Nine purified preparations of prolactin from four species were assayed by local pigeon crop sac bioassay and by radioreceptor assay. The two methods were highly correlated (r = 0.934). The regression equation was radioreceptor assay = 1.22 bioassay - 0.18 indicating a 1:1 correspondence between the two methods for prolactin purified from sheep, rat, horse and pig anterior pituitary glands. (author)

  17. Staff perceptions on pigeon control strategies on the University of South Africa’s Muckleneuk campus

    Directory of Open Access Journals (Sweden)

    Emma Harris

    2017-04-01

    Full Text Available Pigeons are often considered a nuisance in urban environments, leading to the attempted control or eradication of their populations. This study explored the perceptions of 246 staff members employed on the University of South Africa’s Muckleneuk campus to ascertain the extent and nature of the perceived pigeon problem, suggested control methodologies and their anticipated results. The study found that the majority of staff do not consider the pigeons to pose a problem on the campus and that, should control be imposed, humane, non-lethal measures were preferred over eradication. The isolated pigeon-related complaints revealed that the management’s negative perceptions of the pigeons were not representative of staff members in general. The study concludes that a comprehensive public participation process is a necessary and integral part of the development and implementation of a sustainable and efficient pigeon control plan.

  18. Helminth-bacteria interaction in the gut of domestic pigeon Columba livia domestica.

    Science.gov (United States)

    Biswal, Debraj; Nandi, Anadi Prasad; Chatterjee, Soumendranath

    2016-03-01

    The present paper is an attempt to study the interaction between the helminth parasite and bacteria residing in the gut of domestic pigeon, Columba livia domestica. Biochemical and molecular characterization of the gut bacterial isolate were done and the isolate was identified as Staphylococcus sp. DB1 (JX442510). The interaction of Staphylococcus sp. with Cotugnia cuneata, an intestinal helminth parasite of domestic pigeon was studied on the basis of the difference between 'mean worm burden' of antibiotic treated infected pigeons and infected pigeons without any antibiotic treatment. The ANOVA and Tukey tests of the data obtained showed that antibiotic treatment reduced the mean worm burden significantly. The biochemical properties of Staphylococcus sp. DB1 (JX442510) also showed a mutualistic relationship with the physiology of C. cuneata.

  19. The complete mitochondrial genome of the Jacobin pigeon (Columba livia breed Jacobin).

    Science.gov (United States)

    He, Wen-Xiao; Jia, Jin-Feng

    2015-06-01

    The Jacobin is a breed of fancy pigeon developed over many years of selective breeding that originated in Asia. In the present work, we report the complete mitochondrial genome sequence of Jacobin pigeon for the first time. The total length of the mitogenome was 17,245 bp with the base composition of 30.18% for A, 23.98% for T, 31.88% for C, and 13.96% for G and an A-T (54.17 %)-rich feature was detected. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region. The arrangement of all genes was identical to the typical mitochondrial genomes of pigeon. The complete mitochondrial genome sequence of Jacobin pigeon would serve as an important data set of the germplasm resources for further study.

  20. The Occurrence of Heamoproteuscolumbae in Pigeons ...

    African Journals Online (AJOL)

    The Occurrence of Heamoproteuscolumbae in Pigeons ( Columbidaelivia ) Based on Microscopy and PCR Based Method Analysis and Identification of New Lineage in the MalAvi Data Base in Kano State, Nigeria.

  1. Rail passengers rights

    Directory of Open Access Journals (Sweden)

    Đurđev Dušanka J.

    2016-01-01

    Full Text Available The legal framework of rail passengers rights is set out in a combination of international and European law: an international measure, the rather unwieldy Uniform Rules concerning the Contract for International Carriage of Passengers and Luggage by Rail, forming part of the Convention concerning International Carriage by Rail of 9 May 1980 (as amended by the Vilnius Protocol of 3 June 1999 ['CIV'], lays down a basic framework which is then fleshed out by more recent EU legislation, Regulation (EC No 1371/2007 on Rail Passengers ' Rights and Obligations. Regulation 1371/2007/EC on rail passenger rights and obligations sets out minimum quality standards that have to be guaranteed to all passengers on all lines. .

  2. Chlamydial infections in feral pigeons in Europe: Review of data and focus on public health implications.

    Science.gov (United States)

    Magnino, S; Haag-Wackernagel, D; Geigenfeind, I; Helmecke, S; Dovc, A; Prukner-Radovcić, E; Residbegović, E; Ilieski, V; Laroucau, K; Donati, M; Martinov, S; Kaleta, E F

    2009-03-16

    Feral pigeons (Columba livia domestica), which thrive in most European towns and cities, are commonly infected with the zoonotic bacterium Chlamydophila psittaci, the agent of psittacosis (also known as ornithosis) in humans. A number of surveys carried out over the last thirty years across Europe have detected high seropositivity values and high percentages of infection in feral pigeon populations. Overall, when considering data from 11 European countries, seropositivity values to C. psittaci in the sampled populations ranged from 19.4% to 95.6%. In most surveys, the complement fixation test was used, and antibodies were detected in 19.4-66.3% of the samples, with a median of 46.1%. Indirect immunofluorescence and ELISA tests were employed less frequently, but led to the detection of higher percentages of seropositivity (23.7-67.7% and 35.9-95.6%, respectively). Attempts to grow C. psittaci in cell culture or embryonated chicken eggs were successful in 2-42.3% and 0-57.1% of samples, respectively, antigen detection methods were positive in 2.3-40% of samples, while conventional PCR and real-time PCR using different genomic targets detected the organism in 3.4-50% of samples. Twenty-five C. psittaci isolates from pigeons were typed as ompA genotype B (n=14), E (n=10) and E/B (n=1). The huge increase of feral pigeon populations in Europe is a major cause of concern for the detrimental effect of pigeon droppings on environmental hygiene, in addition to the extensive damage due to the fouling of buildings and monuments. The most important pathogenic organism transmissible from feral pigeons to humans is C. psittaci, with 101 cases of disease reported in the literature. Exposure to C. psittaci-contaminated dust, direct contact with pigeons through handling and, to a lesser extent, through pigeon feeding have been identified as hazardous exposures in more than half of the human cases, while loose or transient contacts with feral pigeons have been mentioned in about 40

  3. Characterization of the complete mitochondrial genome of the king pigeon (Columba livia breed king).

    Science.gov (United States)

    Zhang, Rui-Hua; He, Wen-Xiao; Xu, Tong

    2015-06-01

    The king pigeon is a breed of pigeon developed over many years of selective breeding primarily as a utility breed. In the present work, we report the complete mitochondrial genome sequence of king pigeon for the first time. The total length of the mitogenome was 17,221 bp with the base composition of 30.14% for A, 24.05% for T, 31.82% for C, and 13.99% for G and an A-T (54.22 %)-rich feature was detected. It harbored 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and one non-coding control region (D-loop region). The arrangement of all genes was identical to the typical mitochondrial genomes of pigeon. The complete mitochondrial genome sequence of king pigeon would serve as an important data set of the germplasm resources for further study.

  4. Narrowing down the conditions for extinction of Pavlovian feature-positive discriminations in humans.

    Science.gov (United States)

    van Vooren, Priya R; Franssen, Mathijs; Beckers, Tom; Hermans, Dirk; Baeyens, Frank

    2012-12-01

    The aim of this study was to delineate the minimal conditions for extinction of Pavlovian modulation in humans. Previous experiments at our lab showed that, after X-- A+/A- acquisition training, X- trials did not extinguish differential X-- A+/A- responding, while X-- A- trials did. Additionally, X-- A- extinction training seemed only to extinguish differential X-- A+/A- responding, while leaving differential responding on a concurrently trained Y [Symbol: see text] B+/B- discrimination intact. It thus seemed that the X-- A+/A- discrimination can only be extinguished by X-- A- extinction trials. (Rescorla, Journal of Experimental Psychology: Animal Behavior Processes 12, 16-24, 1986), on the other hand, found that the minimal conditions for extinction were broader in pigeons: Namely, he found that an acquired X-- A+/A- discrimination could be extinguished by presenting the original feature X in combination with a different target (B) that was minimally trained as an exciter. We thus wanted to examine whether this was also the case in humans. We found that nonreinforced X-- B- presentations did not abolish discriminative X-- A/A responding when target B was a nonreinforced stimulus. Nonreinforced X-- B- trials did extinguish the X-- A+/A- discrimination when target B had previously been trained as a target for modulation (X-- B+/B- or Y [Symbol: see text] B+/B- training) or as a reinforced exciter (B+). Our results thusf parallel and extend those in nonhuman animals (Rescorla, Journal of Experimental Psychology: Animal Behavior Processes 12, 16-24, 1986).

  5. Complete Genome Sequence of Genotype VI Newcastle Disease Viruses Isolated from Pigeons in Pakistan

    OpenAIRE

    Wajid, Abdul; Rehmani, Shafqat Fatima; Sharma, Poonam; Goraichuk, Iryna V.; Dimitrov, Kiril M.; Afonso, Claudio L.

    2016-01-01

    Two complete genome sequences of Newcastle disease virus (NDV) are described here. Virulent isolates pigeon/Pakistan/Lahore/21A/2015 and pigeon/Pakistan/Lahore/25A/2015 were obtained from racing pigeons sampled in the Pakistani province of Punjab during 2015. Phylogenetic analysis of the fusion protein genes and complete genomes classified the isolates as members of NDV class II, genotype VI.

  6. Haemoproteus, a blood parasite, in domestic pigeons and mourning doves in Maryland

    Science.gov (United States)

    Knisley, J.O.; Herman, C.M.

    1967-01-01

    The occurrence of Haemoproteus in pigeons throughout the world and in mourning doves in the United States is reviewed. Haemoproteus has previously been reported only once from pigeons in Maryland. During this study it was found in all of 18 pigeons from one area but in none of 12 from an adjacent area. No infections were found in 90 Maryland mourning doves. All of the 10 mourning doves from Florida were infected whereas 60 nestlings from Texas and Mississippi had no parasites. None was found in 358 nestling white-winged doves from Texas.

  7. Associative Symmetry, Antisymmetry, and a Theory of Pigeons' Equivalence-Class Formation

    Science.gov (United States)

    Urcuioli, Peter J.

    2008-01-01

    Five experiments assessed associative symmetry in pigeons. In Experiments 1A, 1B and 2, pigeons learned two-alternative symbolic matching with identical sample- and comparison-response requirements and with matching stimuli appearing in all possible locations. Despite controlling for the nature of the functional stimuli and insuring all requisite…

  8. Use of Cowpea and Pigeon pea as Nutritional Ingredients in Culture ...

    African Journals Online (AJOL)

    Use of Cowpea and Pigeon pea as Nutritional Ingredients in Culture Media. ... Sudan Journal of Medical Sciences ... Cheap, locally available plant seeds such as cowpea (Vigna unguiculata) and pigeon pea (Cajanus cajan) could be used in the design and formulation of microbial culture media in order to reduce the cost.

  9. Avian metapneumovirus subtype B experimental infection and tissue distribution in chickens, sparrows, and pigeons.

    Science.gov (United States)

    Gharaibeh, S; Shamoun, M

    2012-07-01

    Avian metapneumovirus (aMPV) is a respiratory virus that infects a range of avian hosts, including chickens and turkeys. Migratory and local wild birds are implicated in aMPV spread among farms, countries, and seasonal outbreaks of the disease. A subtype B aMPV isolate from commercial chicken flocks suffering from respiratory disease was experimentally inoculated oculonasally into 7-week old chickens, young pigeons, and sparrows. Chickens showed minimal tracheal rales, whereas pigeons and sparrows were asymptomatic. Shedding of aMPV was detected by reverse transcription polymerase chain reaction on homogenates from nasal turbinates. At 5 days postinfection, 5 of 5 chickens, 2 of 5 pigeons, and 1 of 5 sparrows were positive; at 10 or 15 days, none were positive. At 2 and 5 days, aMPV antigens were localized at the ciliated boarder of respiratory epithelium in nasal cavity and trachea of chickens, as well as to the conjunctival epithelium. Pigeons had detectable viral antigens in only the trachea at 2 and 5 days; sparrow tissues did not show any positive staining. At the end of the experiment, at 21 days postinfection, 14 of 15 inoculated chickens seroconverted against aMPV, but none of the inoculated pigeons or sparrows did. The authors believe that pigeons and sparrows have the ability to transmit the virus between chicken farms, although they do not consider pigeons and sparrows as natural hosts for aMPV, given that they failed to seroconvert. In conclusion, pigeons and sparrows are partially susceptible to aMPV infection, probably acting more as mechanical vectors because infection is only temporary and short-lived.

  10. Genomic diversity and evolution of the head crest in the rock pigeon

    DEFF Research Database (Denmark)

    Shapiro, Michael D.; Kronenberg, Zev; Li, Cai

    2013-01-01

    The geographic origins of breeds and the genetic basis of variation within the widely distributed and phenotypically diverse domestic rock pigeon (Columba livia) remain largely unknown. We generated a rock pigeon reference genome and additional genome sequences representing domestic and feral...

  11. Generalization of free-operant avoidance behavior in pigeons1

    Science.gov (United States)

    Klein, Marty; Rilling, Mark

    1974-01-01

    Three groups of four pigeons, trained to press a treadle on a free-operant avoidance schedule, were given auditory discrimination training. Alternating 2-min components of avoidance and no shock were paired with either a tone or white noise. The pigeons were subsequently given two types of generalization tests, with and without avoidable shocks scheduled. Two of the groups, trained interdimensionally, produced excitatory and inhibitory generalization gradients along the tone frequency dimension. A predicted post-discrimination gradient was computed from the algebraic summation of these gradients of excitation and inhibition. The predicted gradient was compared with the actual post-discrimination gradient obtained from the third group of pigeons that had been given intradimensional discrimination training on the tone frequency dimension. The predicted postdiscrimination gradient agreed in shape with the empirical postdiscrimination gradient. The results in general support Spence's (1937) gradient interaction theory. PMID:16811735

  12. NPS Transit System Passenger Boardings Study: Converting Ticket Sales to Passenger Boardings.

    Science.gov (United States)

    2016-01-01

    This report examines the reporting of passenger boardings (unlinked passenger trips) by NPS transit systems that use a ticket sales conversion methodology. By studying and validating the park units' passenger boarding methodology from converting tick...

  13. Complete Genome Sequence of Genotype VI Newcastle Disease Viruses Isolated from Pigeons in Pakistan

    Science.gov (United States)

    Wajid, Abdul; Rehmani, Shafqat Fatima; Sharma, Poonam; Goraichuk, Iryna V.; Dimitrov, Kiril M.

    2016-01-01

    Two complete genome sequences of Newcastle disease virus (NDV) are described here. Virulent isolates pigeon/Pakistan/Lahore/21A/2015 and pigeon/Pakistan/Lahore/25A/2015 were obtained from racing pigeons sampled in the Pakistani province of Punjab during 2015. Phylogenetic analysis of the fusion protein genes and complete genomes classified the isolates as members of NDV class II, genotype VI. PMID:27540069

  14. Intra-annual patterns in adult band-tailed pigeon survival estimates

    Science.gov (United States)

    Casazza, Michael L.; Coates, Peter S.; Overton, Cory T.; Howe, Kristy H.

    2015-01-01

    Context: The band-tailed pigeon (Patagioenas fasciata) is a migratory species occurring in western North America with low recruitment potential and populations that have declined an average of 2.4% per year since the 1960s. Investigations into band-tailed pigeon demographic rates date back to the early 1900s, and existing annual survival rate estimates were derived in the 1970s using band return data.

  15. Functional similarities between pigeon 'milk' and mammalian milk: induction of immune gene expression and modification of the microbiota.

    Directory of Open Access Journals (Sweden)

    Meagan J Gillespie

    Full Text Available Pigeon 'milk' and mammalian milk have functional similarities in terms of nutritional benefit and delivery of immunoglobulins to the young. Mammalian milk has been clearly shown to aid in the development of the immune system and microbiota of the young, but similar effects have not yet been attributed to pigeon 'milk'. Therefore, using a chicken model, we investigated the effect of pigeon 'milk' on immune gene expression in the Gut Associated Lymphoid Tissue (GALT and on the composition of the caecal microbiota. Chickens fed pigeon 'milk' had a faster rate of growth and a better feed conversion ratio than control chickens. There was significantly enhanced expression of immune-related gene pathways and interferon-stimulated genes in the GALT of pigeon 'milk'-fed chickens. These pathways include the innate immune response, regulation of cytokine production and regulation of B cell activation and proliferation. The caecal microbiota of pigeon 'milk'-fed chickens was significantly more diverse than control chickens, and appears to be affected by prebiotics in pigeon 'milk', as well as being directly seeded by bacteria present in pigeon 'milk'. Our results demonstrate that pigeon 'milk' has further modes of action which make it functionally similar to mammalian milk. We hypothesise that pigeon 'lactation' and mammalian lactation evolved independently but resulted in similarly functional products.

  16. Introducing cultivated trees into the wild: Wood pigeons as dispersers of domestic olive seeds

    Science.gov (United States)

    Perea, Ramón; Gutiérrez-Galán, Alejandro

    2016-02-01

    Animals may disperse cultivated trees outside the agricultural land, favoring the naturalization or, even, the invasiveness of domestic plants. However, the ecological and conservation implications of new or unexplored mutualisms between cultivated trees and wild animals are still far from clear. Here, we examine the possible role of an expanding and, locally, overabundant pigeon species (Columba palumbus) as an effective disperser of domestic olive trees (Olea europaea), a widespread cultivated tree, considered a naturalized and invasive species in many areas of the world. By analyzing crop and gizzard content we found that olive fruits were an important food item for pigeons in late winter and spring. A proportion of 40.3% pigeons consumed olive seeds, with an average consumption of 7.8 seeds per pigeon and day. Additionally, most seed sizes (up to 0.7 g) passed undamaged through the gut and were dispersed from cultivated olive orchards to areas covered by protected Mediterranean vegetation, recording minimal dispersal distances of 1.8-7.4 km. Greenhouse experiments showed that seeds dispersed by pigeons significantly favored the germination and establishment in comparison to non-ingested seeds. The ability of pigeons to effectively disperse domestic olive seeds may facilitate the introduction of cultivated olive trees into natural systems, including highly-protected wild olive woodlands. We recommend harvesting ornamental olive trees to reduce both pigeon overpopulation and the spread of artificially selected trees into the natural environment.

  17. Orientation of pigeons exposed to constant light and released from familiar sites.

    Science.gov (United States)

    Dall'Antonia, P; Luschi, P

    1993-12-01

    It has been proposed that homing pigeons may use pilotage to orient home when released from familiar sites. To test this possibility, a group of pigeons was released from familiar locations after being exposed to a constant bright light. This treatment produced the loss of the circadian rhythmicity of general activity of the birds and thus presumably impaired their time-compensating sun compass mechanism. Experimental birds, both anosmic and olfactorily unimpaired, did not show any tendency to orient home, their bearing distributions being generally not different from random. Their homing performances were also affected. These results show that initial orientation of pigeons released from familiar sites entails the use of the sun compass even when the birds are released after a treatment that makes them arrhythmic in their activity. The possibility that pilotage may play a role in the first part of the homing flight of pigeons remains to be demonstrated.

  18. Discrimination of complex human behavior by pigeons (Columba livia and humans.

    Directory of Open Access Journals (Sweden)

    Muhammad A J Qadri

    Full Text Available The cognitive and neural mechanisms for recognizing and categorizing behavior are not well understood in non-human animals. In the current experiments, pigeons and humans learned to categorize two non-repeating, complex human behaviors ("martial arts" vs. "Indian dance". Using multiple video exemplars of a digital human model, pigeons discriminated these behaviors in a go/no-go task and humans in a choice task. Experiment 1 found that pigeons already experienced with discriminating the locomotive actions of digital animals acquired the discrimination more rapidly when action information was available than when only pose information was available. Experiments 2 and 3 found this same dynamic superiority effect with naïve pigeons and human participants. Both species used the same combination of immediately available static pose information and more slowly perceived dynamic action cues to discriminate the behavioral categories. Theories based on generalized visual mechanisms, as opposed to embodied, species-specific action networks, offer a parsimonious account of how these different animals recognize behavior across and within species.

  19. Antioxidation, angiotensin converting enzyme inhibition activity, nattokinase, and antihypertension of Bacillus subtilis (natto)-fermented pigeon pea.

    Science.gov (United States)

    Lee, Bao-Hong; Lai, Yi-Syuan; Wu, She-Ching

    2015-12-01

    Because of the high incidence of cardiovascular diseases in Asian countries, traditional fermented foods from Asia have been increasingly investigated for antiatherosclerotic effects. This study investigated the production of nattokinase, a serine fibrinolytic enzyme, in pigeon pea by Bacillus subtilis fermentation. B. subtilis 14714, B. subtilis 14715, B. subtilis 14716, and B. subtilis 14718 were employed to produce nattokinase. The highest nattokinase activity in pigeon pea was obtained using B. subtilis 14715 fermentation for 32 hours. In addition, the levels of antioxidants (phenolics and flavonoids) and angiotensin converting enzyme inhibitory activity were increased in B. subtilis 14715-fermented pigeon pea, compared with those in nonfermented pigeon pea. In an animal model, we found that both water extracts of pigeon pea (100 mg/kg body weight) and water extracts of B. subtilis-fermented pigeon pea (100 mg/kg body weight) significantly improved systolic blood pressure (21 mmHg) and diastolic blood pressure (30 mmHg) in spontaneously hypertensive rats. These results suggest that Bacillus-fermented pigeon pea has benefits for cardiovascular health and can be developed as a new dietary supplement or functional food that prevents hypertension. Copyright © 2015. Published by Elsevier B.V.

  20. Antioxidation, angiotensin converting enzyme inhibition activity, nattokinase, and antihypertension of Bacillus subtilis (natto-fermented pigeon pea

    Directory of Open Access Journals (Sweden)

    Bao-Hong Lee

    2015-12-01

    Full Text Available Because of the high incidence of cardiovascular diseases in Asian countries, traditional fermented foods from Asia have been increasingly investigated for antiatherosclerotic effects. This study investigated the production of nattokinase, a serine fibrinolytic enzyme, in pigeon pea by Bacillus subtilis fermentation. B. subtilis 14714, B. subtilis 14715, B. subtilis 14716, and B. subtilis 14718 were employed to produce nattokinase. The highest nattokinase activity in pigeon pea was obtained using B. subtilis 14715 fermentation for 32 hours. In addition, the levels of antioxidants (phenolics and flavonoids and angiotensin converting enzyme inhibitory activity were increased in B. subtilis 14715-fermented pigeon pea, compared with those in nonfermented pigeon pea. In an animal model, we found that both water extracts of pigeon pea (100 mg/kg body weight and water extracts of B. subtilis-fermented pigeon pea (100 mg/kg body weight significantly improved systolic blood pressure (21 mmHg and diastolic blood pressure (30 mmHg in spontaneously hypertensive rats. These results suggest that Bacillus-fermented pigeon pea has benefits for cardiovascular health and can be developed as a new dietary supplement or functional food that prevents hypertension.

  1. Effect of isolation techniques on the characteristics of pigeon pea (Cajanus cajan) protein isolates

    OpenAIRE

    Adenekan, Monilola K.; Fadimu, Gbemisola J.; Odunmbaku, Lukumon A.; Oke, Emmanuel K.

    2017-01-01

    Abstract In this study, the effect of different isolation techniques on the isolated proteins from pigeon pea was investigated. Water, methanol, ammonium sulfate, and acetone were used for the precipitation of proteins from pigeon pea. Proximate composition, and antinutritional and functional properties of the pigeon pea flour and the isolated proteins were measured. Data generated were statistically analyzed. The proximate composition of the water‐extracted protein isolate was moisture 8.30%...

  2. Mitochondrial genome sequence of Egyptian swift Rock Pigeon (Columba livia breed Egyptian swift).

    Science.gov (United States)

    Li, Chun-Hong; Shi, Wei; Shi, Wan-Yu

    2015-06-01

    The Egyptian swift Rock Pigeon is a breed of fancy pigeon developed over many years of selective breeding. In this work, we report the complete mitochondrial genome sequence of Egyptian swift Rock Pigeon. The total length of the mitogenome was 17,239 bp and its overall base composition was estimated to be 30.2% for A, 24.0% for T, 31.9% for C and 13.9% for G, indicating an A-T (54.2%)-rich feature in the mitogenome. It contained the typical structure of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a non-coding control region (D-loop region). The complete mitochondrial genome sequence of Egyptian swift Rock Pigeon would serve as an important data set of the germplasm resources for further study.

  3. Screening for several potential pathogens in feral pigeons (Columba livia in Madrid

    Directory of Open Access Journals (Sweden)

    Ballesteros Carlos

    2010-06-01

    Full Text Available Abstract Background Pathogens with the zoonotic potential to infect humans, such as Campylobacter jejuni, Campylobacter coli and Chlamydophila psittaci, can be found in feral pigeons (Columba livia. Given the high density of these birds in the public parks and gardens of most cities, they may pose a direct threat to public health. Methods A total of 118 pigeons were captured in three samplings carried out in 2006-2007 in public parks and gardens in Madrid, Spain. Standard haematological and morphological analyses were carried out on the pigeons. PCR was used to screen for the presence of Campylobacter jejuni, C. coli and Chlamydophila psittaci. Positive samples were confirmed by DNA sequencing. Results The analyses demonstrated a high prevalence of Chlamydophila psittaci (52.6% and Campylobacter jejuni (69.1% among the birds captured. In contrast, Campylobacter coli was rarely detected (1.1%. Conclusions Pigeons in Madrid can carry Chlamydophila psittaci and Campylobacter jejuni. They may be asymptomatic or subclinical carriers of both pathogens.

  4. Screening for several potential pathogens in feral pigeons (Columba livia) in Madrid

    Science.gov (United States)

    2010-01-01

    Background Pathogens with the zoonotic potential to infect humans, such as Campylobacter jejuni, Campylobacter coli and Chlamydophila psittaci, can be found in feral pigeons (Columba livia). Given the high density of these birds in the public parks and gardens of most cities, they may pose a direct threat to public health. Methods A total of 118 pigeons were captured in three samplings carried out in 2006-2007 in public parks and gardens in Madrid, Spain. Standard haematological and morphological analyses were carried out on the pigeons. PCR was used to screen for the presence of Campylobacter jejuni, C. coli and Chlamydophila psittaci. Positive samples were confirmed by DNA sequencing. Results The analyses demonstrated a high prevalence of Chlamydophila psittaci (52.6%) and Campylobacter jejuni (69.1%) among the birds captured. In contrast, Campylobacter coli was rarely detected (1.1%). Conclusions Pigeons in Madrid can carry Chlamydophila psittaci and Campylobacter jejuni. They may be asymptomatic or subclinical carriers of both pathogens. PMID:20569487

  5. Attributional and relational processing in pigeons

    Directory of Open Access Journals (Sweden)

    Dennis eGarlick

    2011-02-01

    Full Text Available Six pigeons were trained using a matching-to-sample procedure where sample and rewarded comparisons matched on both attributional (color and relational (horizontal or vertical orientation dimensions. Probes then evaluated the pigeons’ preference to comparisons that varied in these dimensions. A strong preference was found for the attribute of color. The discrimination was not found to transfer to novel colors, however, suggesting that a general color rule had not been learned. Further, when color could not be used to guide responding, some influence of other attributional cues such as shape, but not relational cues, was found. We conclude that pigeons based their performance on attributional properties of but not on relational properties between elements in our matching-to-sample procedure.. Future studies should look at examining other attributes to compare attributional versus relational processing.

  6. Evaluation of gastroscopy and biopsy of the proventriculus and ventriculus in pigeons (Columba livia).

    Science.gov (United States)

    Sladakovic, Izidora; Ellis, Angela E; Divers, Stephen J

    2017-01-01

    OBJECTIVE To evaluate the efficacy and safety of gastroscopy and biopsy of the proventriculus and ventriculus in pigeons (Columba livia). ANIMALS 15 adult pigeons. PROCEDURES Each pigeon was anesthetized, and the upper gastrointestinal tract (from the cervical portion of the esophagus to the ventriculus) was endoscopically evaluated by use of a rigid endoscope inserted orally. Saline (0.9% NaCl) solution was orally infused to achieve lumen dilation and visibility. Two mucosal biopsy specimens were collected from each of the proventriculus and ventriculus, histologically evaluated, and graded for crush artifacts and depth. Pigeons were monitored for adverse effects for 3 to 6 days after the procedure, after which they were euthanized for necropsy. RESULTS Gastroscopy via the oral approach provided excellent visibility of the lumen and mucosal surfaces of the proventriculus and cranial portion of the ventriculus and was safe provided that appropriate precautions were taken. Two intraoperative deaths occurred at the beginning of the study; following procedure refinement, no additional deaths occurred. No major adverse effects of the procedure were detected in the remaining 13 pigeons during the postoperative monitoring period or at necropsy. Diagnostic quality of proventriculus specimens was adequate for 10 of 13 pigeons. Eight of 13 ventriculus specimens were of inadequate quality, and only 3 were of adequate quality. CONCLUSIONS AND CLINICAL RELEVANCE Gastroscopy was useful for evaluating the lumen and mucosal surface of the proventriculus and ventriculus in pigeons, and biopsy of those organs was safely performed with the appropriate technique. Further evaluation of these techniques is needed in birds with clinical disease and birds of other species.

  7. Molecular survey on zoonotic tick-borne bacteria and chlamydiae in feral pigeons (Columba livia domestica).

    Science.gov (United States)

    Ebani, Valentina Virginia; Bertelloni, Fabrizio; Mani, Paolo

    2016-04-01

    To determine the presence of zoonotic tick-borne bacteria in feral pigeons (Columba livia domestica) from urban areas. Spleen samples from 84 feral pigeons, found dead with traumatic injuries in urban areas, were examined by PCR to detect DNA of Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato, Coxiella burnetii, Rickettsia spp., and Chlamydophila spp. Twenty (23.8%) pigeons were infected by tick-borne agents, in particular 2 (2.38%) animals resulted positive for Bartonella spp., 5 (5.95%) for C. burnetii, 5 (5.95%) for Rickettsia spp., 13 (15.47%) for B. burgdorferi sensu lato. All birds scored negative for A. phagocytophilum. Moreover, 17 (20.23%) pigeons were positive for Chlamydophila spp. and among them 10 (11.9%) for Chlamydophila psittaci. Mixed infections by two or three agents were detected in 8 (9.52%) animals. Feral pigeons living in urban and periurban areas are a hazard for the human health as source of several pathogens. The obtained results confirm pigeons as reservoirs of chlamydial agents and suggest that they may be involved in the epidemiology of zoonotic tick-borne infections too. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  8. Effect of gamma irradiation on pollen and seed fertility in pigeon pea

    International Nuclear Information System (INIS)

    Ahmed John, S.

    1997-01-01

    A study was undertaken in pigeon pea parents and their F 1 hybrid to analyse the pollen and seed fertility following gamma irradiation. It is found that the reduction of pollen and seed fertility in pigeon pea was lesser over those of black gram and cowpea. 5 refs., 1 tab

  9. Autoshaping of key pecking in pigeons with negative reinforcement.

    Science.gov (United States)

    Rachlin, H

    1969-07-01

    Pigeons exposed to gradually increasing intensities of pulsing electric shock pecked a key and thereby reduced the intensity of shock to zero for 2 min. Acquisition of key pecking was brought about through an autoshaping process in which periodic brief keylight presentations immediately preceded automatic reduction of the shock. On the occasions of such automatic reduction of shock preceding the first measured key peck, little or no orientation to the key was observed. Observations of pigeons with autoshaping of positive reinforcement also revealed little evidence of orientation toward the key.

  10. Associative symmetry in the pigeon after successive matching-to-sample training.

    Science.gov (United States)

    Frank, Andrea J; Wasserman, Edward A

    2005-09-01

    If an organism is explicitly taught an A-->B association, then might it also spontaneously learn the symmetrical B-->A association? Little evidence attests to such "associative symmetry" in nonhuman animals. We report for the first time a clear case of associative symmetry in the pigeon. Experiment 1 used a successive go/no go matching-to-sample procedure, which showed all of the training and testing stimuli in one location and intermixed arbitrary and identity matching trials. We found symmetrical responding that was as robust during testing (B-->A) as during training (A-->B). In Experiment 2, we trained different pigeons using only arbitrary matching trials before symmetry testing. No symmetrical responding was found. In Experiment 3, we trained other pigeons with only arbitrary matching trials and then tested for symmetry. When these pigeons, too, did not exhibit symmetrical responding, we retrained them with intermixed identity and arbitrary matching trials. Less robust symmetrical responding was obtained here than in Experiment 1. Collectively, these results suggest that identity matching may have to be learned concurrently with arbitrary matching from the outset of training for symmetry to emerge.

  11. The Other Shoe: An Early Operant Conditioning Chamber for Pigeons

    OpenAIRE

    Sakagami, Takayuki; Lattal, Kennon A.

    2016-01-01

    We describe an early operant conditioning chamber fabricated by Harvard University instrument maker Ralph Gerbrands and shipped to Japan in 1952 in response to a request of Professor B. F. Skinner by Japanese psychologists. It is a rare example, perhaps the earliest still physically existing, of such a chamber for use with pigeons. Although the overall structure and many of the components are similar to contemporary pigeon chambers, several differences are noted and contrasted to evolutionary...

  12. Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour.

    Science.gov (United States)

    Bamidele, Oluwaseun P; Akanbi, Charles T

    2013-09-01

    The effect of gamma irradiation at various doses (5, 10, 15, 20 kGy) was observed on pigeon pea flour stored for 3 months on proximate composition, functional properties, and peroxide value. Sensory evaluation was also carried out on bean cake (moinmoin) made from nonirradiated and irradiated pigeon pea flour. The results showed that stored gamma-irradiated samples had significantly lower (P flours showed slight increase in water absorption capacity, swelling capacity and bulk density. The peroxide value of crude oil increased significantly with dose increases for the period of storage. The sensory evaluation of moinmoin samples prepared from irradiated pigeon pea flour showed no significant difference from the moinmoin sample prepared from nonirradiated flour. It can be concluded that gamma irradiation can extend the shelf life of pigeon pea flour.

  13. A robo-pigeon based on an innovative multi-mode telestimulation system.

    Science.gov (United States)

    Yang, Junqing; Huai, Ruituo; Wang, Hui; Lv, Changzhi; Su, Xuecheng

    2015-01-01

    In this paper, we describe a new multi-mode telestimulation system for brain-microstimulation for the navigation of a robo-pigeon, a new type of bio-robot based on Brain-Computer Interface (BCI) techniques. The multi-mode telestimulation system overcomes neuron adaptation that was a key shortcoming of the previous single-mode stimulation by the use of non-steady TTL biphasic pulses accomplished by randomly alternating pulse modes. To improve efficiency, a new behavior model ("virtual fear") is proposed and applied to the robo-pigeon. Unlike the previous "virtual reward" model, the "virtual fear" behavior model does not require special training. The performance and effectiveness of the system to alleviate the adaptation of neurons was verified by a robo-pigeon navigation test, simultaneously confirming the practicality of the "virtual fear" behavioral model.

  14. Dissociation of Procedural and Working Memory in Pigeons (Columba livia

    Directory of Open Access Journals (Sweden)

    Walter T. Herbranson

    2016-07-01

    Full Text Available A new method was developed to concurrently investigate procedural memory and working memory in pigeons. Pigeons performed a sequence of keypecks across 3 response keys in a serial response task, with periodic choice probes for the location of a recently produced response. Procedural memory was operationally defined as decreasing response times to predictable cues in the sequence. Working memory was reflected by accurate responses to the choice probes. Changing the sequence of required keypecks to a random sequence interfered with procedural memory in the form of slowed response times, but did not prevent pigeons from effectively using working memory to remember specific cue locations. Conversely, changing exposure duration of to a cue location influenced working memory but had no effect on procedural memory. Double dissociations such as this have supported the multiple systems approach to the study of memory in cognitive psychology and neuroscience, and they encourage a similar approach in comparative psychology.

  15. Figure-ground assignment in pigeons: evidence for a figural benefit.

    Science.gov (United States)

    Lazareva, Olga E; Castro, Leyre; Vecera, Shaun P; Wasserman, Edward A

    2006-07-01

    Four pigeons discriminated whether a target spot appeared on a colored figural shape or on a differently colored background by first pecking the target and then reporting its location: on the figure or the background. We recorded three dependent variables: target detection time, choice response time, and choice accuracy. The birds were faster to detect the target, to report its location, and to learn the correct response on figure trials than on background trials. Later tests suggested that the pigeons might have attended to the figural region as a whole rather than using local properties in performing the figure-background discrimination. The location of the figural region did not affect figure-ground assignment. Finally, when 4 other pigeons had to detect and peck the target without making a choice report, no figural advantage emerged in target detection time, suggesting that the birds' attention may not have been automatically summoned to the figural region.

  16. Newcastle disease B1 vaccine strain in wild rock pigeons in Atlanta, Georgia

    Science.gov (United States)

    From June to October of 2012, samples were collected from wild Rock Pigeons (Columba livia) in urban neighborhoods of Atlanta, Georgia to ascertain the prevalence of pigeon paramyxovirus serotype-1 (PPMV-1). PPMV-1 strains are a subset of avian paramyxovirus serotype-1 (APMV-1) commonly isolated fro...

  17. Pigeon RIG-I Function in Innate Immunity against H9N2 IAV and IBDV

    Directory of Open Access Journals (Sweden)

    Wenping Xu

    2015-07-01

    Full Text Available Retinoic acid-inducible gene I (RIG-I, a cytosolic pattern recognition receptor (PRR, can sense various RNA viruses, including the avian influenza virus (AIV and infectious bursal disease virus (IBDV, and trigger the innate immune response. Previous studies have shown that mammalian RIG-I (human and mice and waterfowl RIG-I (ducks and geese are essential for type I interferon (IFN synthesis during AIV infection. Like ducks, pigeons are also susceptible to infection but are ineffective propagators and disseminators of AIVs, i.e., “dead end” hosts for AIVs and even highly pathogenic avian influenza (HPAI. Consequently, we sought to identify pigeon RIG-I and investigate its roles in the detection of A/Chicken/Shandong/ZB/2007 (H9N2 (ZB07, Gansu/Tianshui (IBDV TS and Beijing/CJ/1980 (IBDV CJ-801 strains in chicken DF-1 fibroblasts or human 293T cells. Pigeon mRNA encoding the putative pigeon RIG-I analogs was identified. The exogenous expression of enhanced green fluorescence protein (EGFP-tagged pigeon RIG-I and caspase activation and recruitment domains (CARDs, strongly induced antiviral gene (IFN-β, Mx, and PKR mRNA synthesis, decreased viral gene (M gene and VP2 mRNA expression, and reduced the viral titers of ZB07 and IBDV TS/CJ-801 virus strains in chicken DF-1 cells, but not in 293T cells. We also compared the antiviral abilities of RIG-I proteins from waterfowl (duck and goose and pigeon. Our data indicated that waterfowl RIG-I are more effective in the induction of antiviral genes and the repression of ZB07 and IBDV TS/CJ-801 strain replication than pigeon RIG-I. Furthermore, chicken melanoma differentiation associated gene 5(MDA5/ mitochondrial antiviral signaling (MAVS silencing combined with RIG-I transfection suggested that pigeon RIG-I can restore the antiviral response in MDA5-silenced DF-1 cells but not in MAVS-silenced DF-1 cells. In conclusion, these results demonstrated that pigeon RIG-I and CARDs have a strong antiviral

  18. Clinical and serological tests for arboviruses in free-living domestic pigeons (Columba livia).

    Science.gov (United States)

    Ramos, Bruna Alves; Chiang, Jannifer Oliveira; Martins, Lívia Carício; Chagas, Liliane Leal das; Silva, Franko de Arruda E; Ferreira, Milene Silveira; Freitas, Maria Nazaré Oliveira; Alcantara, Bianca Nascimento de; Silva, Sandro Patroca da; Miranda, Stefânia Araújo; Sepulvreda, Barbara Alves; Corrêa, Layna Thayssa Guimarães; Negrão, Andréa Maria Góes; Vasconcelos, Pedro Fernando da Costa; Casseb, Alexandre do Rosário

    2017-08-01

    In this study, we evaluated the role of free-living domestic pigeons (Columba livia) as a reservoir of arboviruses in the city of Belém, state of Pará, Brazil. We investigated the presence of antibodies against the most prevalent arboviruses. This study was aimed at evaluating some clinical and physical parameters of domestic pigeons, including the presence of antibodies to Amazon-endemic arboviruses. Eighty-five healthy pigeons were captured in Mangal das Garças Park, in Belém, and were bled. Upon capture, the birds were subjected to a clinical examination in search of alterations that could indicate the presence of arboviruses. Blood samples were converted to serum and tested using the haemagglutination inhibition (HI) technique with a panel of 19 antigens of arboviruses circulating in the Amazon. The confirmation assay for the positive reactions to the viral species tested by HI was a neutralisation test in new-born Swiss albino mice (Mus musculus) [mouse neutralisation test (MNT)]. A total of 10 (11.8%) serum samples tested positive for antiflavivirus antibodies by HI. All the samples positive for the HI test were subjected to MNT for detection of viruses and yielded negative results (logarithmic neutralisation index < 1.7). The results represent the first serological detection of antiarbovirus antibodies in domestic pigeons as potential hosts of arboviruses in Brazil. The detection of haemagglutination-inhibiting antibodies against genus Flavivirus indicated that there was recent contact between the analysed domestic pigeons and these arboviruses. Further studies are needed to evaluate the role of free-living pigeons in the maintenance cycle and spread of arboviruses in the Amazon.

  19. The impact of deoxynivalenol on pigeon health : occurrence in feed, toxicokinetics and interaction with salmonellosis

    OpenAIRE

    Antonissen, Gunther; Haesendonck, Roel; Devreese, Mathias; Broekaert, Nathan; Verbrugghe, Elin; De Saeger, Sarah; Audenaert, Kris; Haesebrouck, Freddy; Pasmans, Frank; Ducatelle, Richard; Croubels, Siska; Martel, An

    2016-01-01

    Seed-based pigeon diets could be expected to result in exposure of pigeons to mycotoxins such as deoxynivalenol (DON). Ingestion of low to moderate contamination levels of DON may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host-pathogen interactions and thus different outcome of infections. Here we demonstrate that DON was one of the most frequently detected mycotoxins in seed-based racing pigeons feed, contaminating 5 out of 10 samples (range 177-...

  20. The Influence of Social Parameters on the Homing Behavior of Pigeons.

    Directory of Open Access Journals (Sweden)

    Julia Mehlhorn

    Full Text Available Homing pigeons develop preferred routes when released alone several times from the same site, but they sometimes diverge from their preferred route when subsequently released with another pigeon. Additionally, group flights show a better homing performance than solo flights. But this knowledge is based on studies involving both sexes and lacks analyses of social parameters such as mating or breeding status, even though it is known that such parameters have an influence on behavior and on motivation for specific behavioral patterns. GPS trackers were used to track 24 homing pigeons (9 breeding pairs and 6 unmated females as they performed a familiar 10km route in various pair and group combinations. Comparisons of efficiency indices (quotient between straight-line distance and pigeon's track reveal that unmated females show the best efficiency in single flights. Generally, group flights show the best efficiency followed by pair flights with a social partner of the opposite sex. Pair flights with the mated partner exhibit the poorest performance. Additionally, just before squabs hatching, females show a higher efficiency index when released at 8 am, compared to releases at 2 pm. Our results indicate that homing flight efficiency can provide insight into individual motivation and that social parameters have an influence on homing performance on a familiar route.

  1. Isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings.

    Science.gov (United States)

    Soltani, Maryam; Bayat, Mansour; Hashemi, Seyed J; Zia, Mohammadali; Pestechian, Nader

    2013-01-01

    Invasive fungal infections cause considerable morbidity and mortality in immunocompromised hosts. Pigeon droppings could especially be a potential carrier in the spread of pathogenic yeasts and mold fungi into the environment. The objective of this study was to isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings. One hundred twenty samples of pigeon droppings were suspended 1:10 in saline solution and then cultured. Identification of C. neoformans was performed on bird seed agar, presence of a capsule on India ink preparation, urease production on urea agar medium and RapID yeast plus system. The identification of candida species was based on micro-morphological analysis on corn meal-Tween 80 agar, RapID yeast plus system and growth in CHROMagar candida. The identification of other fungi was based on macromorphologic, microscopic, biochemical and physiological characteristics. The highest frequency of yeasts and mold fungi were observed in Candida albicans 6.6% and Penicillium spp. 25%. The frequency rate of C. neoformans isolation was 2.5%. Several types of fungi are present in pigeon droppings that can spread in environment and transmit to children and elderly as well as immunocompromised patients who are at increased risk of contracting opportunistic diseases.

  2. Isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings

    Directory of Open Access Journals (Sweden)

    Maryam Soltani

    2013-01-01

    Full Text Available Background: Invasive fungal infections cause considerable morbidity and mortality in immunocompromised hosts. Pigeon droppings could especially be a potential carrier in the spread of pathogenic yeasts and mold fungi into the environment. The objective of this study was to isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings. Materials and Methods: One hundred twenty samples of pigeon droppings were suspended 1:10 in saline solution and then cultured. Identification of C. neoformans was performed on bird seed agar, presence of a capsule on India ink preparation, urease production on urea agar medium and RapID yeast plus system. The identification of candida species was based on micro-morphological analysis on corn meal-Tween 80 agar, RapID yeast plus system and growth in CHROMagar candida. The identification of other fungi was based on macromorphologic, microscopic, biochemical and physiological characteristics. Results: The highest frequency of yeasts and mold fungi were observed in Candida albicans 6.6% and Penicillium spp. 25%. The frequency rate of C. neoformans isolation was 2.5%. Conclusion: Several types of fungi are present in pigeon droppings that can spread in environment and transmit to children and elderly as well as immunocompromised patients who are at increased risk of contracting opportunistic diseases.

  3. Cavity Attenuated Phase Shift (CAPS) Method for Airborne Aerosol Light Extinction Measurement: Instrument Validation and First Results from Field Deployment

    Science.gov (United States)

    Petzold, A.; Perim de Faria, J.; Berg, M.; Bundke, U.; Freedman, A.

    2015-12-01

    Monitoring the direct impact of aerosol particles on climate requires the continuous measurement of aerosol optical parameters like the aerosol extinction coefficient on a regular basis. Remote sensing and ground-based networks are well in place (e.g., AERONET, ACTRIS), whereas the regular in situ measurement of vertical profiles of atmospheric aerosol optical properties remains still an important challenge in quantifying climate change. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System; www.iagos.org) responds to the increasing requests for long-term, routine in situ observational data by using commercial passenger aircraft as measurement platform. However, scientific instrumentation for the measurement of atmospheric constituents requires major modifications before being deployable aboard in-service passenger aircraft. Recently, a compact and robust family of optical instruments based on the cavity attenuated phase shift (CAPS) technique has become available for measuring aerosol light extinction. While this technique was successfully deployed for ground-based atmospheric measurements under various conditions, its suitability for operation aboard aircraft in the free and upper free troposphere still has to be demonstrated. In this work, the modifications of a CAPS PMex instrument for measuring aerosol light extinction on aircraft, the results from subsequent laboratory tests for evaluating the modified instrument prototype, and first results from a field deployment aboard a research aircraft will be covered. In laboratory studies, the instrument showed excellent agreement (deviation CAPS PMex instrument response within 10% deviation. During the field deployment, aerosol extinction coefficients and associated aerosol size distributions have been measured and will be presented as comparison studies between measured and calculated data.

  4. Isolation and characterization of a herpesvirus from feral pigeons in China.

    Science.gov (United States)

    Zhao, Panpan; Ma, Jian; Guo, Ying; Tian, Li; Guo, Guangyang; Zhang, Kexin; Xing, Mingwei

    2015-12-01

    A herpesvirus was isolated during a diagnostic investigation of severe cases of conjunctivitis in feral pigeons (Columba livia f. domestica). Isolates of the virus were recovered from throat swabs of the pigeons followed by inoculation of the swab samples in chicken embryo fibroblasts. Pigeons inoculated with the isolated virus had similar clinical signs to those observed in naturally infected birds. Transmission electron microscopy revealed viral structures with typical herpesvirus morphology. Polymerase chain reaction amplification, using herpesvirus-identifying primers resulted in an amplicon of the expected size for herpesvirus. Sequencing of these amplicons and database comparisons identified the herpesvirus UL30 homologue. Phylogenetic reconstructions suggested that the isolated herpesvirus belongs to the Mardivirus genus of Alphaherpesvirinae. Using the current herpesvirus nomenclature conventions, the authors propose that the herpesvirus be named Columbid herpesvirus-1 Heilongjiang. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Modeling and Optimization of Collaborative Passenger Control in Urban Rail Stations under Mass Passenger Flow

    Directory of Open Access Journals (Sweden)

    Lili Wang

    2015-01-01

    Full Text Available With the rapid development of urban rail transit, the phenomenon of outburst passenger flows flocking to stations is occurring much more frequently. Passenger flow control is one of the main methods used to ensure passengers’ safety. While most previous studies have only focused on control measures inside the target station, ignoring the collaboration between stops, this paper puts emphasis on joint passenger control methods during the occurrence of large passenger flows. To provide a theoretic description for the problem under consideration, an integer programming model is built, based on the analysis of passenger delay and the processes by which passengers alight and board. Taking average passenger delay as the objective, the proposed model aims to disperse the pressure of oversaturated stations into others, achieving the optimal state for the entire line. The model is verified using a case study and the results show that restricted access measures taken collaboratively by stations produce less delay and faster evacuation. Finally, a sensitivity analysis is conducted, from which we find that the departure interval and maximum conveying capacity of the train affect passenger delay markedly in the process of passenger control and infer that control measures should be taken at stations near to the one experiencing an emergency.

  6. Qualitative similarities in the visual short-term memory of pigeons and people.

    Science.gov (United States)

    Gibson, Brett; Wasserman, Edward; Luck, Steven J

    2011-10-01

    Visual short-term memory plays a key role in guiding behavior, and individual differences in visual short-term memory capacity are strongly predictive of higher cognitive abilities. To provide a broader evolutionary context for understanding this memory system, we directly compared the behavior of pigeons and humans on a change detection task. Although pigeons had a lower storage capacity and a higher lapse rate than humans, both species stored multiple items in short-term memory and conformed to the same basic performance model. Thus, despite their very different evolutionary histories and neural architectures, pigeons and humans have functionally similar visual short-term memory systems, suggesting that the functional properties of visual short-term memory are subject to similar selective pressures across these distant species.

  7. The watershed years of 1958-1962 in the Harvard Pigeon Lab.

    OpenAIRE

    Catania, A Charles

    2002-01-01

    During the years 1958-1962, the final years of support by the National Science Foundation for B. F. Skinner's Pigeon Lab in Memorial Hall at Harvard University, 20 or so pigeon experiments (plus some with other organisms) ran concurrently 7 days a week. The research style emphasized experimental analyses, exploratory procedures, and the parametric exploration of variables. This reminiscence describes some features of the laboratory, the context within which it operated, and the activities of ...

  8. The Emergence of Symmetry in a Conditional Discrimination Task Using Different Responses as Propioceptive Samples in Pigeons

    Science.gov (United States)

    Garcia, Andres; Benjumea, Santiago

    2006-01-01

    In Experiment 1, 10 pigeons were exposed to a successive symbolic matching-to-sample procedure in which the sample was generated by the pigeons' own behavior. Each trial began with both response keys illuminated white, one being the "correct" key and the other the "incorrect" key. The pigeons had no way of discriminating which key was correct and…

  9. Invasion of Flukes of the Echinostomatidae Family in Racing Pigeon ( Columba livia var. domestica) Lofts.

    Science.gov (United States)

    Ledwoń, Aleksandra; Dolka, Beata; Piasecki, Tomasz; Dolka, Izabella; Szeleszczuk, Piotr

    2016-06-01

    Over 4 years, only two known cases of fluke invasions were diagnosed in racing pigeons ( Columba livia ) originating from different regions of Poland. In both cases, the invasion was characterized by a very high mortality (approximately 70%), and the source of the infestation was snails of the Lymnaeidae family eaten by pigeons. Fluke invasions in pigeons are extremely rare and to date have not been described in Poland. Therefore, the occurrence of the symptoms of hemorrhagic diarrhea and sudden deaths of either adult pigeons or nestlings were suspected to be associated with poisoning. Autopsy revealed an invasion of flukes causing hemorrhagic enteritis. Renal failure and spleen atrophy were also found in the birds. Using molecular biology techniques, infestation with the fluke Echinostoma revolutum was determined in the second case.

  10. Clinicopathologic, gross necropsy, and histologic findings after intramuscular injection of carprofen in a pigeon (Columba livia) model.

    Science.gov (United States)

    Zollinger, Tawina J; Hoover, John P; Payton, Mark E; Schiller, Chris A

    2011-09-01

    To evaluate the pathologic effects of carprofen in a pigeon model (Columba livia), 52 young adult pigeons were used in a randomized control study design. Sixteen pigeons were randomly assigned to 1 of 3 treatment groups and received carprofen by intramuscular injection at dosages of either 2, 5, or 10 mg/kg once daily for 7 days. Four pigeons served as saline-injected controls. Four pigeons from each group and 1 control pigeon were randomly selected on days 2, 4, 6, and 8 to obtain blood samples and then were euthanatized and submitted for necropsy. Histologic lesions in pectoral muscle, liver, kidney, and digestive tract tissue samples were ranked in severity as 0, normal/not present; 1, minimal; 2, mild; 3, mild to moderate; 4, moderate; 5, moderate to marked; and 6, marked pathologic changes. Two-way analysis of variance (day x dose) and pairwise t tests revealed significant (P carprofen treatments. Gross lesions in carprofen-treated pigeons were pale injection sites (23/48 [47.9%]), mottled yellow livers (9/48 [18.8%]), and congestion of small intestines (7/48 [14.6%]). Liver, kidney, and muscle injection sites had significantly increased (P carprofen is associated with increased aspartate aminotransferase and alanine aminotransferase enzyme concentrations, gross lesions in muscle injection sites and liver, and histologic lesions in liver and muscle.

  11. Substitution effects in a generalized token economy with pigeons.

    Science.gov (United States)

    Andrade, Leonardo F; Hackenberg, Timothy D

    2017-01-01

    Pigeons made repeated choices between earning and exchanging reinforcer-specific tokens (green tokens exchangeable for food, red tokens exchangeable for water) and reinforcer-general tokens (white tokens exchangeable for food or water) in a closed token economy. Food and green food tokens could be earned on one panel; water and red water tokens could be earned on a second panel; white generalized tokens could be earned on either panel. Responses on one key produced tokens according to a fixed-ratio schedule, whereas responses on a second key produced exchange periods, during which all previously earned tokens could be exchanged for the appropriate commodity. Most conditions were conducted in a closed economy, and pigeons distributed their token allocation in ways that permitted food and water consumption. When the price of all tokens was equal and low, most pigeons preferred the generalized tokens. When token-production prices were manipulated, pigeons reduced production of the tokens that increased in price while increasing production of the generalized tokens that remained at a fixed price. The latter is consistent with a substitution effect: Generalized tokens increased and were exchanged for the more expensive reinforcer. When food and water were made freely available outside the session, token production and exchange was sharply reduced but was not eliminated, even in conditions when it no longer produced tokens. The results join with other recent data in showing sustained generalized functions of token reinforcers, and demonstrate the utility of token-economic methods for assessing demand for and substitution among multiple commodities in a laboratory context. © 2016 Society for the Experimental Analysis of Behavior.

  12. 50 CFR 20.103 - Seasons, limits, and shooting hours for mourning and white-winged doves and wild pigeons.

    Science.gov (United States)

    2010-10-01

    ... mourning and white-winged doves and wild pigeons. 20.103 Section 20.103 Wildlife and Fisheries UNITED... shooting hours for mourning and white-winged doves and wild pigeons. This section provides for the annual hunting of certain doves and pigeons in the 48 contiguous United States. The mourning dove hunting...

  13. Ontogeny and localization of γ-crystallin antigen in the developing pigeon (Columba livia) lens

    NARCIS (Netherlands)

    Brahma, S.K.; Rabaey, M.; Doorenmaalen, W.J. van

    Ontogeny and localization of the lens γ-crystallin antigen were investigated in the embryonic and post-embryonic pigeon lenses by the indirect immunofluorescence with antiserum from rabbit immunized with isolated pigeon lens γ-crystallin. The results show that γ-crystallin appears for the first time

  14. The associative relation underlying autoshaping in the pigeon1

    Science.gov (United States)

    Woodruff, Guy; Williams, D. R.

    1976-01-01

    Fifteen pigeons were exposed to either response-independent or response-dependent schedules of water reinforcement, whereby water was injected directly into the unrestrained pigeons' mandibles. Key-contact responses were released by a lighted key correlated with water, but not by a lighted key uncorrelated with water. A negative response-reinforcer contingency suppressed autoshaped key-contact responses, resulting in responding directed away from the lighted key. In all pigeons, water injected directly into the mandibles elicited a consummatory fixed-action pattern of “mumbling” and swallowing. The lighted key correlated with water released a broader set of both appetitive and consummatory responses: approach to the lighted key, “bowing”, “rooting”, “mumbling”, and swallowing. Key-contact responses were “rooting” and “mumbling” motions of the beak on the surface of the key. Views of autoshaping based on stimulus substitution or stimulus surrogation do not fully explain the origin of autoshaped responses not previously elicited by the reinforcer. The present findings are consonant with views of conditioning that emphasize the large degree of biological pre-organization in conditioned response patterns, and the importance of associative factors in the control of such patterns. PMID:16811924

  15. Host cytokine responses of pigeons infected with highly pathogenic Thai avian influenza viruses of subtype H5N1 isolated from wild birds.

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Hayashi

    Full Text Available Highly pathogenic avian influenza virus (HPAIV of the H5N1 subtype has been reported to infect pigeons asymptomatically or induce mild symptoms. However, host immune responses of pigeons inoculated with HPAIVs have not been well documented. To assess host responses of pigeons against HPAIV infection, we compared lethality, viral distribution and mRNA expression of immune related genes of pigeons infected with two HPAIVs (A/Pigeon/Thailand/VSMU-7-NPT/2004; Pigeon04 and A/Tree sparrow/Ratchaburi/VSMU-16-RBR/2005; T.sparrow05 isolated from wild birds in Thailand. The survival experiment showed that 25% of pigeons died within 2 weeks after the inoculation of two HPAIVs or medium only, suggesting that these viruses did not cause lethal infection in pigeons. Pigeon04 replicated in the lungs more efficiently than T.sparrow05 and spread to multiple extrapulmonary organs such as the brain, spleen, liver, kidney and rectum on days 2, 5 and 9 post infection. No severe lesion was observed in the lungs infected with Pigeon04 as well as T.sparrow05 throughout the collection periods. Encephalitis was occasionally observed in Pigeon04- or T.sparrow05-infected brain, the severity, however was mostly mild. To analyze the expression of immune-related genes in the infected pigeons, we established a quantitative real-time PCR analysis for 14 genes of pigeons. On day 2 post infection, Pigeon04 induced mRNA expression of Mx1, PKR and OAS to a greater extent than T.sparrow05 in the lungs, however their expressions were not up-regulated concomitantly on day 5 post infection when the peak viral replication was observed. Expressions of TLR3, IFNα, IL6, IL8 and CCL5 in the lungs following infection with the two HPAIVs were low. In sum, Pigeon04 exhibited efficient replication in the lungs compared to T.sparrow05, but did not induce excessive host cytokine expressions. Our study has provided the first insight into host immune responses of pigeons against HPAIV infection.

  16. Prevalence of Toxoplasma gondii antibodies in domestic (Columba livia domestica) and wild (Columba livia livia) pigeons in Niğde region, Turkey.

    Science.gov (United States)

    Karatepe, Mustafa; Kılıç, Selçuk; Karatepe, Bilge; Babür, Cahit

    2011-01-01

    The present study was conducted to investigate the prevalence of Toxoplasma gondii specific antibodies in domestic (Columba livia domestica) and wild (Columba livia livia) pigeons between October 2003-June 2004. Blood samples were collected from 216 pigeons, consisting of 105 (55 female, 50 male) domestic pigeons and 111 (53 female, 58 male) wild pigeons. The sera were tested for T. gondii antibodies using the Sabin Feldman Dye Test (SFDT). One of the 105 (0.95%) domestic pigeon and one of the 111 (0.90%) wild pigeon were found to be seropositive for T. gondii antibodies at the titer of 1:16. This is the first serological study on toxoplasmosis in the domestic and wild pigeon in the Niğde region of Turkey.

  17. Nutritional composition and antinutritional properties of maize ogi cofermented with pigeon pea.

    Science.gov (United States)

    Okafor, Uchechukwu I; Omemu, Adebunkola M; Obadina, Adewale O; Bankole, Mobolaji O; Adeyeye, Samuel A O

    2018-03-01

    Maize was cofermented with pigeon pea for ogi production and evaluated for nutritional (proximate composition, minerals, vitamins, and amino acid profile analyses) and antinutritional (phytate, tannin, and trypsin inhibitor activity analyses) qualities. White maize and pigeon pea were mixed at ratios of 90:10, 80:20, 70:30, 60:40, and 50:50, respectively, with 100:0 serving as the control. Mixtures were cofermented for 96 hr at 27°C ± 2°C and nutritional, mineral, and antinutritional qualities were analyzed using analysis of variance. Results of proximate analysis showed that the values were significantly difference at p  ≤   .05. Maize cofermented with pigeon pea at a ratio of 60:40 had the highest protein (22.79 mg/100 g), fat (19.27 mg/100 g), ash (2.98 mg/100 g), crude fiber (0.73 mg/100 g), and lowest moisture (1.98 mg/100 g) content, and was significantly ( p  ≤   .05) different from the other ratios. Of all the mixtures analyzed, 60:40 was significantly ( p  ≤   .05) different and had the highest Vitamin B 1 , B 2 , and B 3 contents. Amino acid profile results showed that maize cofermented with pigeon pea at a ratio of 60:40 showed the highest contents of lysine (93.95 mg/g), tryptophan (20.38 mg/g), isoleucine (54.78 mg/g), phenylalanine (86.23 mg/g), leucine (109.55 mg/g), and valine (68.29 mg/g), respectively, and was significantly ( p  ≤   .05) different from the other ratios. Results of antinutritional analysis showed low phytate, tannin, and trypsin inhibitor values in maize cofermented with pigeon pea at a ratio of 60:40 when compared with other ratios. The cofermented maize-pigeon pea product 60:40 had high amino acid profile than the others.

  18. Isolation, histopathology and antibiogram of Escherichia coli from pigeons (Columba livia

    Directory of Open Access Journals (Sweden)

    Pankaj Dutta

    2013-04-01

    Full Text Available Aim: To know the prevalence of antibiotic resistant Escherichia coli among dead and/or diarrhoic pigeons in and around greater Guwahati. Materials and Methods: Samples were cultured from dead and/or diarrhoic pigeons and identification was done by standard methods. The sensitivity of the isolated E.coli strains to 15 antibiotics of human and veterinary use was also determined. Organs from those dead birds from which E.coli were recovered were processed according to the routine procedure for histopathological studies. Results: Out of 150 pigeons subjected to microbiological investigation, 91(60.67 % samples were found positive for E. coli.The most frequently occurring serotypes were O157 (9.89%, followed by O68, O121 (7.69%, O9, O75, O131 (5.49%, O2, O13, O22 (3.30%. Antibiogram investigation of the isolates revealed that 91isolates (100% exhibited resistance against Ampicillin followed by Nitro-furantoin (73.62%, Tetracycline (65.93 %, Oxytetracycline (62.63 % and Streptomycin (61.54. Gross changes of some birds showed fibrinous pericarditis and perihepatitis and coligranuloma in different organs like liver and serosal surface of intestine. Microscopically, severe congestion and haemorrhages in different organs such as liver, kidney, lung and intestine. In some cases thick layer of fibrinous exudates with large number of heterophills over the surface of liver and heart with early degenerative changes as well as focal necrosis. Conclusion: The result of this study suggests that antimicrobial-resistant pathogenic E.coli is present in pigeons in and around greater Guwahati. Surveillance programs may be introduced to monitor antimicrobial resistance of pathogenic E.coli in pigeons in and around greater guwahati. [Vet World 2013; 6(2.000: 91-94

  19. Prevalence and Pathology of Trichomoniasis in Free AND#8211; Living Urban Pigeons in the City of Mosul, Iraq

    Directory of Open Access Journals (Sweden)

    Hafidh I. Al- Sadi and Aws Z. Hamodi

    2011-02-01

    Full Text Available The present study was undertaken to determine the prevalence of trichomoniasis and its pathology in pigeons. A total of 100 free living urban pigeons were collected during the months August and September 2007. The overall prevalence was 16%. In infected pigeons, yellowish – white masses of caseous necrotic material were seen grossly in the oral cavity, esophagus, crop, and proventiculus. Pale to yellow necrotic areas were noted in the liver. Multiple foci of caseous necrosis were seen microscopically in the oral mucosa together with heavy infiltration of inflammatory cells (mainly heterophils. Foci of necrotic inflammation were seen in the liver and there was thickening of the lining mucosa of the esophagus due to extensive infiltration of heterophils. Collections of necrotic material were seen in the mucosa and submucosa of the esophagus. Infection occurred more frequently in young than in adult pigeons. A higher prevalence of the infection was noted in male than in female pigeons. In all of the infected pigeons, trichomoniasis occured in the absence of apparent secondary disease. It was concluded that trichomonad infection is fairly common in free living urban pigeons in the city of Mosul, Iraq. [Veterinary World 2011; 4(1.000: 12-14

  20. Captive and free-living urban pigeons (Columba livia) from Brazil as carriers of multidrug-resistant pathogenic Escherichia coli.

    Science.gov (United States)

    Borges, Clarissa A; Maluta, Renato P; Beraldo, Lívia G; Cardozo, Marita V; Guastalli, Elisabete A L; Kariyawasam, Subhashinie; DebRoy, Chitrita; Ávila, Fernando A

    2017-01-01

    Thirty Escherichia coli isolates from captive and free-living pigeons in Brazil were characterised. Virulence-associated genes identified in pigeons included those which occur relatively frequently in avian pathogenic E. coli (APEC) from commercial poultry worldwide. Eleven of 30 E. coli isolates from pigeons, belonging mainly to B1 and B2 phylogenetic groups, had high or intermediate pathogenicity for 1-day-old chicks. The frequency of multi-drug resistant (MDR) E. coli in captive pigeons was relatively high and included one isolate positive for the extended-spectrum β-lactamase (ESBL) gene bla CTX-M-8 . Pulsed field gel electrophoresis (PFGE) showed high heterogeneity among isolates. There is potential for pigeons to transmit antibiotic resistant pathogenic E. coli to other species through environmental contamination or direct contact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Analysis of bus passenger comfort perception based on passenger load factor and in-vehicle time.

    Science.gov (United States)

    Shen, Xianghao; Feng, Shumin; Li, Zhenning; Hu, Baoyu

    2016-01-01

    Although bus comfort is a crucial indicator of service quality, existing studies tend to focus on passenger load and ignore in-vehicle time, which can also affect passengers' comfort perception. Therefore, by conducting surveys, this study examines passengers' comfort perception while accounting for both factors. Then, using the survey data, it performs a two-way analysis of variance and shows that both in-vehicle time and passenger load significantly affect passenger comfort. Then, a bus comfort model is proposed to evaluate comfort level, followed by a sensitivity analysis. The method introduced in this study has theoretical implications for bus operators attempting to improve bus service quality.

  2. Molecular identification of Cryptosporidium spp. in seagulls, pigeons, dogs, and cats in Thailand.

    Science.gov (United States)

    Koompapong, Khuanchai; Mori, Hirotake; Thammasonthijarern, Nipa; Prasertbun, Rapeepun; Pintong, Ai-rada; Popruk, Supaluk; Rojekittikhun, Wichit; Chaisiri, Kittipong; Sukthana, Yaowalark; Mahittikorn, Aongart

    2014-01-01

    Zoonotic Cryptosporidium spp., particularly C. meleagridis, C. canis, and C. felis, are enteric protozoa responsible for major public health concerns around the world. To determine the spread of this parasite in Thailand, we conducted molecular identification of Cryptosporidium spp. from animal samples around the country, by collecting and investigating the feces of seagulls (Chroicocephalus brunnicephalus and Chroicocephalus ridibundus), domestic pigeons (Columba livia domestica), dogs, and cats. Seagull and pigeon samples were collected at the seaside and on the riverside to evaluate their potential for waterborne transmission. Ten pigeon samples were combined into one set, and a total of seven sets were collected. Seventy seagull samples were combined into one set, and a total of 13 sets were collected. In addition, 111 dog samples were collected from cattle farms, and 95 dog and 80 cat samples were collected from a temple. We identified C. meleagridis in pigeons, Cryptosporidium avian genotype III in seagulls, C. canis in dogs, and C. felis in cats. In the temple, the prevalence was 2.1% (2/95) for dogs and 2.5% (2/80) for cats. No Cryptosporidium was found in dog samples from cattle farms. These are the first findings of C. meleagridis in domestic pigeons, and Cryptosporidium avian genotype III in seagulls. Our study invites further molecular epidemiological investigations of Cryptosporidium in these animals and their environment to evaluate the public health risk in Thailand. K. Koompapong et al., published by EDP Sciences, 2014

  3. Molecular identification of Cryptosporidium spp. in seagulls, pigeons, dogs, and cats in Thailand

    Directory of Open Access Journals (Sweden)

    Koompapong Khuanchai

    2014-01-01

    Full Text Available Zoonotic Cryptosporidium spp., particularly C. meleagridis, C. canis, and C. felis, are enteric protozoa responsible for major public health concerns around the world. To determine the spread of this parasite in Thailand, we conducted molecular identification of Cryptosporidium spp. from animal samples around the country, by collecting and investigating the feces of seagulls (Chroicocephalus brunnicephalus and Chroicocephalus ridibundus, domestic pigeons (Columba livia domestica, dogs, and cats. Seagull and pigeon samples were collected at the seaside and on the riverside to evaluate their potential for waterborne transmission. Ten pigeon samples were combined into one set, and a total of seven sets were collected. Seventy seagull samples were combined into one set, and a total of 13 sets were collected. In addition, 111 dog samples were collected from cattle farms, and 95 dog and 80 cat samples were collected from a temple. We identified C. meleagridis in pigeons, Cryptosporidium avian genotype III in seagulls, C. canis in dogs, and C. felis in cats. In the temple, the prevalence was 2.1% (2/95 for dogs and 2.5% (2/80 for cats. No Cryptosporidium was found in dog samples from cattle farms. These are the first findings of C. meleagridis in domestic pigeons, and Cryptosporidium avian genotype III in seagulls. Our study invites further molecular epidemiological investigations of Cryptosporidium in these animals and their environment to evaluate the public health risk in Thailand.

  4. Sneaking a peek: pigeons use peripheral vision (not mirrors) to find hidden food.

    Science.gov (United States)

    Ünver, Emre; Garland, Alexis; Tabrik, Sepideh; Güntürkün, Onur

    2017-07-01

    A small number of species are capable of recognizing themselves in the mirror when tested with the mark-and-mirror test. This ability is often seen as evidence of self-recognition and possibly even self-awareness. Strangely, a number of species, for example monkeys, pigs and dogs, are unable to pass the mark test but can locate rewarding objects by using the reflective properties of a mirror. Thus, these species seem to understand how a visual reflection functions but cannot apply it to their own image. We tested this discrepancy in pigeons-a species that does not spontaneously pass the mark test. Indeed, we discovered that pigeons can successfully find a hidden food reward using only the reflection, suggesting that pigeons can also use and potentially understand the reflective properties of mirrors, even in the absence of self-recognition. However, tested under monocular conditions, the pigeons approached and attempted to walk through the mirror rather than approach the physical food, displaying similar behavior to patients with mirror agnosia. These findings clearly show that pigeons do not use the reflection of mirrors to locate reward, but actually see the food peripherally with their near-panoramic vision. A re-evaluation of our current understanding of mirror-mediated behavior might be necessary-especially taking more fully into account species differences in visual field. This study suggests that use of reflections in a mirrored surface as a tool may be less widespread than currently thought.

  5. Ovotestes and Sexual Reversal in Racing Pigeons

    OpenAIRE

    Chalmers, G. A.

    1986-01-01

    The occurrence of ovotestes associated with male behavioral characteristics in two mature female racing pigeons (Columba livia) is recorded. An ovotestis developed in the area of the vestigial right gonad of one bird and within the functional left ovary of the second bird.

  6. Intermodal Passenger Connectivity Database -

    Data.gov (United States)

    Department of Transportation — The Intermodal Passenger Connectivity Database (IPCD) is a nationwide data table of passenger transportation terminals, with data on the availability of connections...

  7. Quality evaluation of stiff porridges prepared from Irish potato (Solanum tuberosum) and pigeon pea (Cajanus cajan) starch blends.

    Science.gov (United States)

    Abu, Joseph Oneh; Enyinnaya, Chinma Chiemela; James, Samaila; Okeleke, Ezinne

    2012-06-01

    Quality attributes of stiff porridges prepared from Irish potato and pigeon pea starch blends were studied. Starches were extracted from Irish potato and pigeon pea using a wet extraction method. Various ratios of the starches were mixed and analyzed for chemical, functional and pasting properties. The starch blends were then prepared into stiff porridges for sensory evaluation using a 20-man sensory panel. Substitution of Irish potato starch with pigeon pea starch led to increases in protein (0.15 to 1.2%), fat (0.26 to 0.56%) and ash (0.30 to 0.69%) while the amylose content of the starch blends decreased (from 23.8 to 18.4%) respectively. Functional properties such as bulk density (0.75 to 0.60 g/cm(3)), water absorption capacity (3.1 to 2.6 g water/ g sample) and dispersibility (58.6 to 42.7%) decreased significantly (P pigeon pea starch respectively. Pasting properties such as peak, breakdown, final and setback viscosities increased with increasing levels of pigeon pea starch while peak time and pasting temperature decreased. The sensory attributes of stiff porridges were not adversely affected by pigeon pea starch inclusion. Therefore it should be possible to incorporate up to 50% of low digestible pigeon pea starch into Irish potato starch from legumes such as pigeon pea as alternatives to cassava starch in the preparation of stiff porridges. Such porridges made from Irish potato and legume starches could provide additional incentive for individuals requiring decreased and or slow starch digestibility such as diabetics.

  8. Functions of innate and acquired immune system are reduced in domestic pigeons (Columba livia domestica) given a low protein diet

    Science.gov (United States)

    Mabuchi, Yuko; Frankel, Theresa L.

    2016-01-01

    Racing pigeons are exposed to and act as carriers of diseases. Dietary protein requirement for their maintenance has not been determined experimentally despite their being domesticated for over 7000 years. A maintenance nitrogen (protein) requirement (MNR) for pigeons was determined in a balance study using diets containing 6, 10 and 14% crude protein (CP). Then, the effects of feeding the diets were investigated to determine whether they were adequate to sustain innate and acquired immune functions. Nitrogen intake from the 6% CP diet was sufficient to maintain nitrogen balance and body weight in pigeons. However, the immune functions of phagocytosis, oxidative burst and lymphocyte proliferation in pigeons fed this diet were reduced compared with those fed 10 and 14% CP diets. Pigeons given the 6 and 10% CP diets had lower antibody titres following inoculation against Newcastle disease (ND) than those on the 14% CP diet. A confounding factor found on autopsy was the presence of intestinal parasites in some of the pigeons given the 6 and 10% CP diets; however, none of the pigeons used to measure MNR or acquired immunity to ND were infested with parasites. In conclusion, neither the 6 nor 10% CP diets adequately sustained acquired immune function of pigeons. PMID:27069640

  9. 14 CFR 91.517 - Passenger information.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Passenger information. 91.517 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.517 Passenger information. (a) Except as... belts and when smoking is prohibited. (c) If passenger information signs are installed, no passenger or...

  10. Eulimdana clava (Nematoda: Filarioidea) infection in domestic pigeons (Columba livia domestica): Molecular characterization and pathological changes.

    Science.gov (United States)

    Šupić, Jovana; Alić, Alma Šeho; Hasanić, Melida; Goletić, Šejla; Duscher, Georg G; Hodžić, Adnan; Alić, Amer

    2018-02-15

    Filarial nematodes of the Eulimdana genus inhabit subcutaneous tissue of various avian species, mostly Charadriiforme birds. In domestic pigeons, E. clava is the only species recorded in the subcutaneous tissue in a number of isolated cases. In the present study, we discuss the morphology and histopathology of filarial nematodes recovered from subcutaneous tissue of domestic pigeons in Bosnia and Herzegovina. In total 110 pigeons were submitted to necropsy at the Department of Pathology of the Faculty of Veterinary Medicine in Sarajevo. At necropsy, in four pigeons (3.6%) numerous thread-like 0.9-2.1 cm long nematode parasites were observed in the subcutaneous tissue, peritracheal and periesophageal connective tissue. In one pigeon, the parasites were also found free in the body cavity around the heart and lungs. In addition, several 80-90 μm long microfilariae were noted in the tissue cross-sections. No significant lesions were observed associated with adult parasites or microfilariae. Based on morphology, host species and localization detected parasites were identified as E. clava. Molecular analyses of the cox1 and 12S rRNA nucleotide sequences herein generated revealed the close genetic relationship to other filarioid nematodes. The importance of the nematodes in pigeons and the lack of sequences in genetic databases for comparison of avian filarial parasites are emphasized. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. 75 FR 26839 - Metrics and Standards for Intercity Passenger Rail Service under Section 207 of the Passenger...

    Science.gov (United States)

    2010-05-12

    ... and Standards for Intercity Passenger Rail Service under Section 207 of the Passenger Rail Investment... performance and service quality of intercity passenger train operations. In compliance with the statute, the... Intercity Passenger Rail Service,'' on the FRA's Web site. Simultaneously, the FRA published a notice in the...

  12. Chemical composition, cholesterol content, and fatty acid profile of pigeon meat as influenced by meat-type breeds.

    Science.gov (United States)

    Pomianowski, J F; Mikulski, D; Pudyszak, K; Cooper, R G; Angowski, M; Józwik, A; Horbanczuk, J O

    2009-06-01

    Two muscles, breast and thigh, were excised from 3 pigeon meat-type breeds (Europigeon, Wrocławski, King) and were analyzed for proximate analysis, cholesterol content, and fatty acid (FA) profile. Among the breeds considered, the lowest protein content of breast muscle was found in Kings (21.73%), whereas the highest fat (7.07%) and ash (1.11%) content of breast muscle (P pigeons. The cholesterol content of both muscles was lowest in Europigeon (23.6 to 25.2 mg/100 g of tissue) as compared with the King and Wrocławski pigeons (30.2 to 44.4 mg/100 g of tissue). The total content of polyunsaturated FA was lower in thigh than in breast muscles (by 4.5 to 12%, depending on the breed). As far as FA composition is concerned, pigeon meat resembles meat types of poultry species. However, due to low cholesterol and a fairly high protein content, pigeon meat can be used as a valuable inclusive component of the human diet.

  13. The viruses of wild pigeon droppings.

    Directory of Open Access Journals (Sweden)

    Tung Gia Phan

    Full Text Available Birds are frequent sources of emerging human infectious diseases. Viral particles were enriched from the feces of 51 wild urban pigeons (Columba livia from Hong Kong and Hungary, their nucleic acids randomly amplified and then sequenced. We identified sequences from known and novel species from the viral families Circoviridae, Parvoviridae, Picornaviridae, Reoviridae, Adenovirus, Astroviridae, and Caliciviridae (listed in decreasing number of reads, as well as plant and insect viruses likely originating from consumed food. The near full genome of a new species of a proposed parvovirus genus provisionally called Aviparvovirus contained an unusually long middle ORF showing weak similarity to an ORF of unknown function from a fowl adenovirus. Picornaviruses found in both Asia and Europe that are distantly related to the turkey megrivirus and contained a highly divergent 2A1 region were named mesiviruses. All eleven segments of a novel rotavirus subgroup related to a chicken rotavirus in group G were sequenced and phylogenetically analyzed. This study provides an initial assessment of the enteric virome in the droppings of pigeons, a feral urban species with frequent human contact.

  14. Capture efficiency and injury rates of band-tailed pigeons using whoosh nets

    Science.gov (United States)

    Coxen, Christopher L.; Collins, Daniel P.; Carleton, Scott A.

    2018-01-01

    Catching ground feeding birds has typically been accomplished through small, walk-in funnel-style traps. This approach is limited because it requires a bird to find its way into the trap, is biased toward less wary birds, and does not allow targeted trapping of individual birds. As part of a large study on Band-tailed Pigeons (Patagioenas fasciata) in New Mexico, we needed a trapping method that would allow more control over the number of birds we could trap at one time, when a trap was deployed, and target trapping of specific individuals. We adopted a relatively novel trapping technique used primarily for shorebirds, whoosh nets, to trap Band-tailed Pigeons at 3 different sites where birds were being fed by local landowners. During 2013–2015, whoosh nets were used to trap 702 Band-tailed Pigeons at 3 different locations in New Mexico. We captured 12.54 ± 8.19 pigeons per shot over 56 capture events across 3 locations (range: 2–39). Some superficial injuries occurred using this technique and typically involved damage to the primary and secondary wing coverts. In 2013, 24% of captured birds had an injury of this nature, but after modifying the net speed, injury rates in 2014 and 2015 dropped to 8% and 7%, respectively. Recaptured previously injured birds showed new feather growth within 2 weeks and showed no signs of injury after 4 weeks. Whoosh nets proved to be a highly effective solution for trapping large numbers of pigeons at baited sites. These systems are easily transported, quickly deployed, and easily adapted to a variety of site conditions. 

  15. Parasite distribution and early-stage encephalitis in Sarcocystis calchasi infections in domestic pigeons (Columba livia f. domestica).

    Science.gov (United States)

    Maier, Kristina; Olias, Philipp; Enderlein, Dirk; Klopfleisch, Robert; Mayr, Sylvia L; Gruber, Achim D; Lierz, Michael

    2015-01-01

    Pigeon protozoal encephalitis is a biphasic, neurologic disease of domestic pigeons (Columba livia f. domestica) caused by the apicomplexan parasite Sarcocystis calchasi. Despite severe inflammatory lesions of the brain, associated parasitic stages have only rarely been identified and the cause of the lesions is still unclear. The aim of this study was therefore to characterize the tissue distribution of S. calchasi within pigeons between the two clinical phases and during the occurrence of neurological signs. For this purpose, a semi-quantitative real-time polymerase chain reaction (PCR) was developed. Forty-five domestic pigeons were infected orally (via a cannula into the crop) with 200 S. calchasi sporocysts and euthanized in groups of three pigeons at intervals of 2 to 10 days over a period of 61 days. Tissue samples including brain and skeletal muscle were examined by histology, immunohistochemistry, and PCR. Schizonts were detected in the liver of one pigeon at day 10 post infection. A mild encephalitis was detected at day 20 post infection, around 4 weeks before the onset of neurological signs. At the same time, immature sarcocysts were present in the skeletal muscle. In seven pigeons a few sarcocysts were identified in the brain, but not associated with any lesion. These results suggest that the encephalitis is induced at a very early stage of the S. calchasi lifecycle rather than in the chronic phase of pigeon protozoal encephalitis. Despite the increasing severity of lesions in the central nervous system, the amount of sarcocysts did not increase. This supports the hypothesis of a delayed-type hypersensitivity response as the cause of the encephalitis. The study also demonstrated that S. calchasi DNA is detectable in tissues negative by histological methods, indicating a higher sensitivity of the real-time PCR.

  16. Defensive behaviors and prosencephalic neurogenesis in pigeons (Columba livia) are affected by environmental enrichment in adulthood.

    Science.gov (United States)

    Melleu, F F; Pinheiro, M V; Lino-de-Oliveira, C; Marino-Neto, J

    2016-05-01

    Neurogenesis in the adult brain appears to be phylogenetically conserved across the animal kingdom. In pigeons and other adult non-oscine birds, immature neurons are observed in several prosencephalic areas, suggesting that neurogenesis may participate in the control of different behaviors. The mechanisms controlling neurogenesis and its relevance to defensive behaviors in non-oscine birds remain elusive. Herein, the contribution of the environment to behavior and neurogenesis of pigeons was investigated. Adult pigeons (Columba livia, n = 6/group), housed in standard (SE) or enriched environment (EE) for 42 days, were exposed to an unfamiliar environment (UE) followed by presentation to a novel object (NO). Video recordings of UE+NO tests were analyzed and scored for latency, duration and frequency of angular head movements, peeping, grooming, immobility and locomotion. Twenty-four hours later, pigeons were submitted to the tonic immobility test (TI) and number of trials for TI and TI duration were scored, followed by euthanasia 2 h later. Brains were immunohistochemically processed to reveal doublecortin (DCX), a marker for newborn neurons. Compared to those housed in SE, the pigeons housed in EE responded to a NO with more immobility. In addition, the pigeons housed in EE presented longer TI, more DCX-immunoreactive (DCX-ir) cells in the hippocampus and fewer DCX-ir cells in the lateral striatum than those housed in SE. There was no correlation between the number of DCX-ir cells and the scores of immobility in behavioral tests. Together, these data suggest that enrichment favored behavioral inhibition and neurogenesis in the adult pigeons through different, parallel mechanisms.

  17. Autoshaping of key pecking in pigeons with negative reinforcement1

    Science.gov (United States)

    Rachlin, Howard

    1969-01-01

    Pigeons exposed to gradually increasing intensities of pulsing electric shock pecked a key and thereby reduced the intensity of shock to zero for 2 min. Acquisition of key pecking was brought about through an autoshaping process in which periodic brief keylight presentations immediately preceded automatic reduction of the shock. On the occasions of such automatic reduction of shock preceding the first measured key peck, little or no orientation to the key was observed. Observations of pigeons with autoshaping of positive reinforcement also revealed little evidence of orientation toward the key. ImagesFig. 3.Fig. 4. PMID:16811371

  18. The Other Shoe: An Early Operant Conditioning Chamber for Pigeons.

    Science.gov (United States)

    Sakagami, Takayuki; Lattal, Kennon A

    2016-05-01

    We describe an early operant conditioning chamber fabricated by Harvard University instrument maker Ralph Gerbrands and shipped to Japan in 1952 in response to a request of Professor B. F. Skinner by Japanese psychologists. It is a rare example, perhaps the earliest still physically existing, of such a chamber for use with pigeons. Although the overall structure and many of the components are similar to contemporary pigeon chambers, several differences are noted and contrasted to evolutionary changes in this most important laboratory tool in the experimental analysis of behavior. The chamber also is testimony to the early internationalization of behavior analysis.

  19. Age-dependent accumulation of heavy metals in liver, kidney and lung tissues of homing pigeons in Beijing, China.

    Science.gov (United States)

    Cui, Jia; Wu, Bin; Halbrook, Richard S; Zang, Shuying

    2013-12-01

    Biomonitoring provides direct evidence of the bioavailability and accumulation of toxic elements in the environment. In the current study, 1-2, 5-6, and 9-10+ year old homing pigeons collected from the Haidian District of Beijing during 2011 were necropsied and concentrations of cadmium, lead, and mercury were measured in liver, lung, and kidney tissue. At necropsy, gray/black discoloration of the margins of the lungs was observed in 98 % of the pigeons. There were no significant differences in metal concentrations as a function of gender. Cadmium concentrations in all tissues and Pb concentrations in the lung tissues were significantly greater in 9-10+ year old pigeons compared to other age groups indicating that Cd and Pb were bioavailable. Mercury concentrations were not significantly different among age groups. Cadmium concentrations in kidney and lung tissues of 9-10+ year old pigeons were similar to or exceeded concentrations of Cd reported in pigeons from another high traffic urban area and most wild avian species from Korea suggesting that Cd in this region of Beijing may be of concern. Homing pigeons provide valuable exposure and bioaccumulation data not readily available from air monitoring alone, thus providing information regarding potential health effects in wildlife and humans in urban areas. As environmental quality standards are implemented in China, homing pigeons will serve as a valuable bio-monitor of the efficacy of these actions.

  20. The complete mitochondrial genome of the Feral Rock Pigeon (Columba livia breed feral).

    Science.gov (United States)

    Li, Chun-Hong; Liu, Fang; Wang, Li

    2014-10-01

    Abstract In the present work, we report the complete mitochondrial genome sequence of feral rock pigeon for the first time. The total length of the mitogenome was 17,239 bp with the base composition of 30.3% for A, 24.0% for T, 31.9% for C, and 13.8% for G and an A-T (54.3 %)-rich feature was detected. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region (D-loop region). The arrangement of all genes was identical to the typical mitochondrial genomes of pigeon. The complete mitochondrial genome sequence of feral rock pigeon would serve as an important data set of the germplasm resources for further study.

  1. Pigeons (Columba livia) know when they will need hints: prospective metacognition for reference memory?

    Science.gov (United States)

    Iwasaki, Sumie; Watanabe, Sota; Fujita, Kazuo

    2018-03-01

    Despite their impressive cognitive abilities, avian species have shown less evidence for metacognition than mammals. We suspect that commonly used tasks such as matching to sample might be too demanding to allow metacognitive processing within birds' working memory. Here, we examined whether pigeons could control their behavior as a function of knowledge levels on a three-item sequence learning task, a reference memory task supposedly requiring fewer working memory resources. The experiment used two types of lists differing in familiarity. One was familiar to the pigeons through repeated exposure, whereas the other was novel in every new session. In test sessions, pigeons could choose between a trial with a hint specifying the next item to peck and one with no hint. However, successful responses in trials with a hint resulted in lowered rates of primary reinforcement: .60 in the first test and .75 in the second. Results showed that two of four pigeons chose the trial with a hint significantly more often before receiving a novel list than the familiar list in the four sessions of the first test, and three did so in the second test. Impressively, one bird showed robust evidence in the very first sessions in both tests. These results suggest that pigeons may monitor their long-term knowledge states and thereby control their environment before starting to solve a task.

  2. Peripheral neuropathy of dietary riboflavin deficiency in racing pigeons.

    Science.gov (United States)

    Wada, Y; Kondo, H; Itakura, C

    1996-02-01

    An occurrence of peripheral neuropathy in nine 14- to 55-day-old racing pigeons was documented. The predominant clinical signs were diarrhea, and leg and wing paralysis. Grossly, there was discoloration and swelling of all the peripheral nerve trunks. Microscopic lesions comprising swelling, fragmentation and demyelination of myelin sheaths, and proliferation of Schwann cells, were seen in the peripheral nerves of all birds examined. These changes were associated with moderate to severe swelling, fragmentation, atrophy and loss of axons. The peripheral nerve lesions in these cases were similar to those of dietary riboflavin deficiency in chickens. An analysis of the diet given to the pigeons indicated that the riboflavin concentration was only 0.9 mg/kg feed.

  3. Differential effects of visual context on pattern discrimination by pigeons (Columba livia) and humans (Homo sapiens).

    Science.gov (United States)

    Kelly, Debbie M; Cook, Robert G

    2003-06-01

    Three experiment examined the role of contextual information during line orientation and line position discriminations by pigeons (Columba livia) and humans (Homo sapiens). Experiment 1 tested pigeons' performance with these stimuli in a target localization task using texture displays. Experiments 2 and 3 tested pigeons and humans, respectively, with small and large variations of these stimuli in a same-different task. Humans showed a configural superiority effect when tested with displays constructed from large elements but not when tested with the smaller, more densely packed texture displays. The pigeons, in contrast, exhibited a configural inferiority effect when required to discriminate line orientation, regardless of stimulus size. These contrasting results suggest a species difference in the perceptionand use of features and contextual information in the discrimination of line information.

  4. Chlamydia psittaci genotype B in a pigeon (Columba livia inhabiting a public place in San José, Costa Rica

    Directory of Open Access Journals (Sweden)

    G. Dolz

    2013-12-01

    Full Text Available Human chlamydiosis is a zoonotic disease of avian origin caused by Chlamydia psittaci. The highest infection rates have been detected in parrots (Psittacidae and pigeons (Columbiformes, the latter most frequently carry the genotypes B and E. These genotypes have been shown to also infect humans. Because pigeons (Columba livia cohabit with humans in urban areas, C. psittaci present in the dust from dry feces of infected pigeons may be transmitted by inhalation and represent a significant public health problem. Between 2012 and 2013 a total of 120 fecal samples were collected from pigeons at four public places (Plaza de la Cultura, Parque Morazán, Parque Central de Guadalupe, Plaza de las Garantías Sociales in San José, Costa Rica. A nested polymerase chain reaction (PCR was used to amplify a region of the outer membrane protein A gene of C. psittaci. Only one sample was positive in PCR and the positive sample was further subjected to sequencing and genotyping. Sequencing identified this sample as C. psittaci genotype B. This study is the first report to show the presence of this organism in pigeons of Costa Rica, and shows that the infected pigeons may represent a significant risk for humans who visit public places that are inhabited by pigeons.

  5. Chlamydia psittaci genotype B in a pigeon (Columba livia) inhabiting a public place in San José, Costa Rica

    Science.gov (United States)

    Dolz, G.; Solórzano-Morales, Á.; Angelova, L.; Tien, C.; Fonseca, L.; Bonilla, M.C.

    2013-01-01

    Human chlamydiosis is a zoonotic disease of avian origin caused by Chlamydia psittaci. The highest infection rates have been detected in parrots (Psittacidae) and pigeons (Columbiformes), the latter most frequently carry the genotypes B and E. These genotypes have been shown to also infect humans. Because pigeons (Columba livia) cohabit with humans in urban areas, C. psittaci present in the dust from dry feces of infected pigeons may be transmitted by inhalation and represent a significant public health problem. Between 2012 and 2013 a total of 120 fecal samples were collected from pigeons at four public places (Plaza de la Cultura, Parque Morazán, Parque Central de Guadalupe, Plaza de las Garantías Sociales) in San José, Costa Rica. A nested polymerase chain reaction (PCR) was used to amplify a region of the outer membrane protein A gene of C. psittaci. Only one sample was positive in PCR and the positive sample was further subjected to sequencing and genotyping. Sequencing identified this sample as C. psittaci genotype B. This study is the first report to show the presence of this organism in pigeons of Costa Rica, and shows that the infected pigeons may represent a significant risk for humans who visit public places that are inhabited by pigeons. PMID:26623327

  6. Chlamydia psittaci genotype B in a pigeon (Columba livia) inhabiting a public place in San José, Costa Rica.

    Science.gov (United States)

    Dolz, G; Solórzano-Morales, Á; Angelova, L; Tien, C; Fonseca, L; Bonilla, M C

    2013-01-01

    Human chlamydiosis is a zoonotic disease of avian origin caused by Chlamydia psittaci. The highest infection rates have been detected in parrots (Psittacidae) and pigeons (Columbiformes), the latter most frequently carry the genotypes B and E. These genotypes have been shown to also infect humans. Because pigeons (Columba livia) cohabit with humans in urban areas, C. psittaci present in the dust from dry feces of infected pigeons may be transmitted by inhalation and represent a significant public health problem. Between 2012 and 2013 a total of 120 fecal samples were collected from pigeons at four public places (Plaza de la Cultura, Parque Morazán, Parque Central de Guadalupe, Plaza de las Garantías Sociales) in San José, Costa Rica. A nested polymerase chain reaction (PCR) was used to amplify a region of the outer membrane protein A gene of C. psittaci. Only one sample was positive in PCR and the positive sample was further subjected to sequencing and genotyping. Sequencing identified this sample as C. psittaci genotype B. This study is the first report to show the presence of this organism in pigeons of Costa Rica, and shows that the infected pigeons may represent a significant risk for humans who visit public places that are inhabited by pigeons.

  7. Factors reducing the expected deflection in initial orientation in clock-shifted homing pigeons.

    Science.gov (United States)

    Gagliardo, Anna; Odetti, Francesca; Ioalè, Paolo

    2005-02-01

    To orient from familiar sites, homing pigeons can rely on both an olfactory map and visual familiar landmarks. The latter can in principle be used in two different ways: either within a topographical map exploited for piloting or in a so-called mosaic map associated with a compass bearing. One way to investigate the matter is to put the compass and the topographical information in conflict by releasing clock-shifted pigeons from familiar locations. Although the compass orientation is in general dominant over a piloting strategy, a stronger or weaker tendency to correct towards the home direction by clock-shifted pigeons released from very familiar sites has often been observed. To investigate which factors are involved in the reduction of the deviation due to clock-shift, we performed a series of releases with intact and anosmic pigeons from familiar sites in unshifted and clock-shifted conditions and a series of releases from the same sites with naive clock-shifted birds. Our data suggest that the following factors have a role in reducing deviation due to the clock-shift: familiarity with the release site, the lack of olfactory information and some unknown site-dependent features.

  8. The effectiveness of chemical carcinogens to induce atherosclerosis in the white carneau pigeon

    International Nuclear Information System (INIS)

    Revis, N.W.; Bull, R.; Laurie, D.; Schiller, C.A.

    1984-01-01

    The frequency of atherosclerotic lesions of the abdominal aorta has been reported to increase significantly in chickens exposed to benzo(a)pyrene and 7,12-dimethylbenz(a,h)anthracene. The present studies were performed to determine in another experimental model frequently used in atherosclerotic studies (i.e. White Carneau Pigeons) whether these and other chemical carcinogens enhance atherosclerosis. The induction and enhancement of atherosclerotic lesions were observed in pigeons treated with 7,12-dimethylbenz(a,h)anthracene, benzo(a)pyrene and 3-methylcholanthrene. The number and size of plaques in the aorta were frequently greater in pigeons treated with the higher concentrations (i.e. 100 mg/kg) of these 3 polycyclic aromatic hydrocarbons. Benzo(e)pyrene and 2,4,6-trichlorophenol were ineffective in the induction or enhancement of atherosclerosis in the pigeons. The results of the present and previous studies suggest that the polycyclic aromatic hydrocarbons (excluding benzo(e)pyrene) may be the only potential atherogens in avian atherosclerosis. This relationship may be associated with how these hydrocarbons are transported in the plasma (i.e. by lipoproteins) as demonstrated by the present distribution studies (author)

  9. 19 CFR 4.50 - Passenger lists.

    Science.gov (United States)

    2010-04-01

    ... VESSELS IN FOREIGN AND DOMESTIC TRADES Passengers on Vessels § 4.50 Passenger lists. (a) The master of... passenger and crew lists, as required by § 4.7(a) of this part. If the vessel is arriving from noncontiguous... 19 Customs Duties 1 2010-04-01 2010-04-01 false Passenger lists. 4.50 Section 4.50 Customs Duties...

  10. A real-time PCR assay for the detection of atypical strains of Chlamydiaceae from pigeons.

    Directory of Open Access Journals (Sweden)

    Aleksandar Zocevic

    Full Text Available Recent evidence of the occurrence of atypical Chlamydiaceae strains in pigeons, different from the established Chlamydiaceae, requires the development of a specific and rapid detection tool to investigate their prevalence and significance. Here is described a new real-time PCR assay that allows specific detection of atypical Chlamydiaceae from pigeons. The assay has been used to assess the dissemination of these strains in field samples collected from Parisian pigeon populations in 2009. The results suggest a limited dissemination compared to the usually higher prevalence of Chlamydia psittaci that is the main species associated with avian chlamydiosis.

  11. Olfactory lateralization in homing pigeons: a GPS study on birds released with unilateral olfactory inputs.

    Science.gov (United States)

    Gagliardo, Anna; Filannino, Caterina; Ioalè, Paolo; Pecchia, Tommaso; Wikelski, Martin; Vallortigara, Giorgio

    2011-02-15

    A large body of evidence has shown that pigeons rely on an olfactory-based navigational map when homing from unfamiliar locations. Previous studies on pigeons released with one nostril occluded highlighted an asymmetry in favour of the right nostril, particularly concerning the initial orientation performance of naïve birds. Nevertheless, all pigeons experiencing only unilateral olfactory input showed impaired homing, regardless of the side of the occluded nostril. So far this phenomenon has been documented only by observing the birds' vanishing bearings. In the present work we recorded the flight tracks of pigeons with previous homing experience equipped with a GPS data logger and released from an unfamiliar location with the right or the left nostril occluded. The analysis of the tracks revealed that the flight path of the birds with the right nostril occluded was more tortuous than that of unmanipulated controls. Moreover, the pigeons smelling with the left nostril interrupted their journey significantly more frequently and displayed more exploratory activity than the control birds, e.g. during flights around a stopover site. These data suggest a more important involvement of the right olfactory system in processing the olfactory information needed for the operation of the navigational map.

  12. Attributable risk of Capillaria species in domestic pigeons (Columba livia domestica

    Directory of Open Access Journals (Sweden)

    M.F. Qamar

    Full Text Available ABSTRACT Fecal samples were collected from 120 domestic pigeons to determine the Attributable risk of Capillaria spp. The Capillaria spp. was observed in 64 out of 120 (51% pigeons (70 males and 50 females under this study. A total of 64 (39 males and 25 females were found naturally infected with Capillaria spp. with infection percentage of 51% and 50% in males and females respectively. Qualitative examinations include the direct microscopy and faecal floatation while quantitative examination includes McMaster technique (worms load was calculated per gram of the faeces. Month wise Attributable risk showed that eggs of the worms were found to be abundant in the month of July during the present study (60% to 73% because of high humidity. Very high and very low temperature is not suitable for the proper development of the eggs. Qualitative and quantitative examination revealed that Capillaria spp. was more prevalent in males (51% than females (50% but overall there was no significant difference (P>0.05 in the male and female because both individuals invest equal amount of energy in search of food and incubating the eggs. Different breeds of pigeons gave different Attributable risk in different months during the study. Groups of pigeons from different locations showed different variable Attributable risk. Areas with high humidity were more suitable for the development of eggs, which is the reason why higher Attributable risk was observed in Shahdara (75% area of Lahore, Pakistan.

  13. A Kinect-based system for automatic recording of some pigeon behaviors.

    Science.gov (United States)

    Lyons, Damian M; MacDonall, James S; Cunningham, Kelly M

    2015-12-01

    Contact switches and touch screens are the state of the art for recording pigeons' pecking behavior. Recording other behavior, however, requires a different sensor for each behavior, and some behaviors cannot easily be recorded. We present a flexible and inexpensive image-based approach to detecting and counting pigeon behaviors that is based on the Kinect sensor from Microsoft. Although the system is as easy to set up and use as the standard approaches, it is more flexible because it can record behaviors in addition to key pecking. In this article, we show how both the fast, fine motion of key pecking and the gross body activity of feeding can be measured. Five pigeons were trained to peck at a lighted contact switch, a pigeon key, to obtain food reward. The timing of the pecks and the food reward signals were recorded in a log file using standard equipment. The Kinect-based system, called BehaviorWatch, also measured the pecking and feeding behavior and generated a different log file. For key pecking, BehaviorWatch had an average sensitivity of 95% and a precision of 91%, which were very similar to the pecking measurements from the standard equipment. For detecting feeding activity, BehaviorWatch had a sensitivity of 95% and a precision of 97%. These results allow us to demonstrate that an advantage of the Kinect-based approach is that it can also be reliably used to measure activity other than key pecking.

  14. Photocurrents in retinal rods of pigeons (Columba livia): kinetics and spectral sensitivity.

    Science.gov (United States)

    Palacios, A G; Goldsmith, T H

    1993-01-01

    1. Membrane photocurrents were recorded from outer segments of isolated retinal rods of pigeons (Columba livia), the first such measurements on the photoreceptors of a bird. The amplitude of the response to 20 ms flashes of narrow wavelength bands of light increases linearly with intensity at low photon fluxes and saturates at higher intensities. The maximum (saturating) photocurrent observed in forty-nine rod cells was 50 pA. Larger responses with less variability in the intensity for half-maximal responses were observed when the physiological saline contained 20 mM bicarbonate (in addition to Hepes buffer). 2. The dependence of peak amplitude on intensity is well fitted by an exponential function; it is usually less well fitted by the Michaelis-Menten (Naka-Rushton) equation. 3. In the presence of bicarbonate, the average sensitivity of pigeon rods to dim flashes was 0.56 pA photon-1 microns -2. The effective collecting area per photon was 1.8 microns 2. About 83 +/- 26 (mean +/- S.D.) photoisomerizations were required for a half-saturating response. 4. The response kinetics of rods to dim flashes can be reasonably well described by a series of four to five either Poisson or independent filters. The time to peak, measured from the mid-point of a 20 ms flash, was 319 +/- 83 ms (mean +/- S.D.). The integration time of the response was 851 +/- 86 ms (mean +/- S.D.) with bicarbonate present and 572 +/- 126 ms in the absence of bicarbonate. The responses of pigeon rods appear to be slower than those of mammals at the same temperature. The fraction of current suppressed by a single photoisomerization is smaller in pigeon than in mammalian rods by a factor of at least two. 5. The spectral sensitivity function was measured between 680 and 330 nm. The maximum at about 505 nm (range 497-508 nm) corresponds to the alpha-band of a vertebrate rhodopsin and agrees with previous behavioural measurements of scotopic sensitivity of pigeons as well as the absorption spectrum of

  15. Contrasting levels of heavy metals in the feathers of urban pigeons from close habitats suggest limited movements at a restricted scale

    International Nuclear Information System (INIS)

    Frantz, Adrien; Pottier, Marie-Anne; Karimi, Battle; Corbel, Hélène; Aubry, Emmanuel; Haussy, Claudy; Gasparini, Julien; Castrec-Rouelle, Maryse

    2012-01-01

    Despite restrictions in emissions, heavy metals may remain a major environmental issue due to their numerous sources and their persistence. Here, we assessed current levels of 4 metals (Copper, Cadmium, Lead, Zinc) in the feathers of 91 feral pigeons (Columba livia) from 7 sites in the urbanized region of Paris. Elements were detected in all pigeons, indicating that metals persist in urbanized areas. The ratio between metal concentrations in the feathers vs. in the environment calculated using data from other studies was 2–90 times higher for cadmium than for other metals, underlying its ecological importance. Concentrations in the feathers depended on locality, suggesting that pigeons remain in local habitats at this restricted scale, as expected from previous observations. Overall, our study suggests that urban feral pigeons may represent a good model system for metal biomonitoring. Highlights: ► We measured the concentrations of 4 heavy metals in pigeon feathers through Paris. ► Cadmium, Copper, Lead and Zinc were present in pigeons from all 7 sites. ► Metals thus still persist in the city though their emissions have been reduced. ► Metal concentrations in the feathers depended on the local origin of the pigeons. ► These differences suggest limited pigeon movements at a very restricted scale. - Concentrations of metals in the feathers of Parisian feral pigeons (Columba livia) strongly differ at a restricted spatial scale, suggesting limited movements in urban areas.

  16. Qualitative similarities in the visual short-term memory of pigeons and people

    OpenAIRE

    Gibson, Brett; Wasserman, Edward; Luck, Steven J.

    2011-01-01

    Visual short-term memory plays a key role in guiding behavior, and individual differences in visual short-term memory capacity are strongly predictive of higher cognitive abilities. To provide a broader evolutionary context for understanding this memory system, we directly compared the behavior of pigeons and humans on a change detection task. Although pigeons had a lower storage capacity and a higher lapse rate than humans, both species stored multiple items in short-term memory and conforme...

  17. Coordinated Behaviour in Pigeon Flocks

    OpenAIRE

    Yomosa, Makoto; Mizuguchi, Tsuyoshi; V?s?rhelyi, G?bor; Nagy, M?t?

    2015-01-01

    We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i) the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii) during ...

  18. Estimating the surface area of birds: using the homing pigeon (Columba livia as a model

    Directory of Open Access Journals (Sweden)

    Cristina R. Perez

    2014-05-01

    Full Text Available Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird.

  19. Estimating the surface area of birds: using the homing pigeon (Columba livia) as a model.

    Science.gov (United States)

    Perez, Cristina R; Moye, John K; Pritsos, Chris A

    2014-05-08

    Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird. © 2014. Published by The Company of Biologists Ltd | Biology Open.

  20. Radiographic and ultrasonographic characteristics of ventral abdominal hernia in pigeons (Columba livia).

    Science.gov (United States)

    Amer, Mohammed S; Hassan, Elham A; Torad, Faisal A

    2018-02-20

    Five female egg-laying pigeons presented with painless, reducible, ventral abdominal swellings located between the keel and the pubis, or close to the cloaca. Based on clinical, radiographic, and ultrasonographic examination, these pigeons were diagnosed with ventral abdominal hernia requiring surgical interference. Reduction was successfully performed under general anesthesia. Radiographic and ultrasonographic examinations were beneficial for confirming the diagnosis and visualizing the hernial content for surgical planning. Lateral radiographs were more helpful than ventrodorsal radiographs for identification of the hernial content and its continuation with the abdominal muscles. Ultrasonographic examination offered a non-invasive diagnostic tool that allowed for the differentiation of hernia from other abdominal swellings. In addition, it played a beneficial role in identification of the hernial content and follow up after surgical interference. In conclusion, radiographic and ultrasonographic examinations were beneficial in the diagnosis, surgical planning, and follow up after surgical interference of ventral abdominal hernia in pigeons.

  1. Avian poxvirus in a free-range juvenile speckled (rock) pigeon (Columba guinea).

    Science.gov (United States)

    Bwala, Dauda G; Fasina, Folorunso O; Duncan, Neil M

    2015-04-30

    A flightless wild juvenile rock pigeon (Columba guinea) with pox-like lesions was picked up on the premises of the Faculty of Veterinary Science, University of Pretoria, Onderstepoort. The pigeon was housed overnight for possible treatment the following day but died before any other intervention could be instituted. At necropsy, coalescing masses of yellowish nodular cutaneous tumour-like lesions principally on the featherless areas were noticed on the dead pigeon's head as well as the beak. Histological examination of the sampled skin lesions revealed multifocal areas of hypertrophic and hyperplastic epidermal epithelial cells with eosinophilic intracytoplasmic inclusion bodies (Bollinger bodies). Extract from the lesion was processed and inoculated on the chorioallantoic membranes (CAM) of 11-day-old embryonated chicken eggs and this produced pocks on one of the CAM at day 7 post-inoculation. Electron microscopy confirmed the presence of poxvirus in the CAM with the pock lesions.

  2. A case of tripody in a pigeon

    International Nuclear Information System (INIS)

    Luethgen, W.; Krautwald-Junghanns, M.E.

    1994-01-01

    In a pigeon of the breed ''Thuringian White Bib'' a stunted third leg was found, which was attached to the left of the ventral cloacal aspect. A disturbance of the embryonic development at the third to fourth day of incubation was thought to be the cause of this anomaly

  3. Summation and subtraction using a modified autoshaping procedure in pigeons.

    Science.gov (United States)

    Ploog, Bertram O

    2008-06-01

    A modified autoshaping paradigm (significantly different from those previously reported in the summation literature) was employed to allow for the simultaneous assessment of stimulus summation and subtraction in pigeons. The response requirements and the probability of food delivery were adjusted such that towards the end of training 12 of 48 trials ended in food delivery, the same proportion as under testing. Stimuli (outlines of squares of three sizes and colors: A, B, and C) were used that could be presented separately or in any combination of two or three stimuli. Twelve of the pigeons (summation groups) were trained with either A, B, and C or with AB, BC, and CA, and tested with ABC. The remaining 12 pigeons (subtraction groups) received training with ABC but were tested with A, B, and C or with AB, BC, and CA. These groups were further subdivided according to whether stimulus elements were presented either in a concentric or dispersed manner. Summation did not occur; subtraction occurred in the two concentric groups. For interpretation of the results, configural theory, the Rescorla-Wagner model, and the composite-stimulus control model were considered. The results suggest different mechanisms responsible for summation and subtraction.

  4. Three-dimensional reconstruction of the pigeon inner ear

    NARCIS (Netherlands)

    Hofman, R.; Segenhout, J. M.; Wit, H. P.

    2009-01-01

    Three-dimensional reconstructions of the inner ear of the pigeon (Columba livia domestica), from two-dimensional images, obtained with (conventional) light microscopy or orthogonal-plane fluorescence optical sectioning (OPFOS), are presented. The results are compared with available information on

  5. Passengers, Information, and Disruptions

    NARCIS (Netherlands)

    E. van der Hurk (Evelien)

    2015-01-01

    markdownabstract__Abstract__ Passengers traveling in public transport generate a detailed digital track record of their journey through using automated fare collection systems and carrying mobile devices. This information on passenger behavior has only recently become available to public

  6. Multiple UV reflectance peaks in the iridescent neck feathers of pigeons

    Science.gov (United States)

    McGraw, Kevin J.

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

  7. Generalization of the disruptive effects of alternative stimuli when combined with target stimuli in extinction.

    Science.gov (United States)

    Podlesnik, Christopher A; Miranda-Dukoski, Ludmila; Jonas Chan, C K; Bland, Vikki J; Bai, John Y H

    2017-09-01

    Differential-reinforcement treatments reduce target problem behavior in the short term but at the expense of making it more persistent long term. Basic and translational research based on behavioral momentum theory suggests that combining features of stimuli governing an alternative response with the stimuli governing target responding could make target responding less persistent. However, changes to the alternative stimulus context when combining alternative and target stimuli could diminish the effectiveness of the alternative stimulus in reducing target responding. In an animal model with pigeons, the present study reinforced responding in the presence of target and alternative stimuli. When combining the alternative and target stimuli during extinction, we altered the alternative stimulus through changes in line orientation. We found that (1) combining alternative and target stimuli in extinction more effectively decreased target responding than presenting the target stimulus on its own; (2) combining these stimuli was more effective in decreasing target responding trained with lower reinforcement rates; and (3) changing the alternative stimulus reduced its effectiveness when it was combined with the target stimulus. Therefore, changing alternative stimuli (e.g., therapist, clinical setting) during behavioral treatments that combine alternative and target stimuli could reduce the effectiveness of those treatments in disrupting problem behavior. © 2017 Society for the Experimental Analysis of Behavior.

  8. Perceptual strategies of pigeons to detect a rotational centre--a hint for star compass learning?

    Directory of Open Access Journals (Sweden)

    Bianca Alert

    Full Text Available Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy.

  9. Visual sensation during pecking in pigeons.

    Science.gov (United States)

    Ostheim, J

    1997-10-01

    During the final down-thrust of a pigeon's head, the eyes are closed gradually, a response that was thought to block visual input. This phase of pecking was therefore assumed to be under feed-forward control exclusively. Analysis of high resolution video-recordings showed that visual information collected during the down-thrust of the head could be used for 'on-line' modulations of pecks in progress. We thus concluded that the final down-thrust of the head is not exclusively controlled by feed-forward mechanisms but also by visual feedback components. We could further establish that as a rule the eyes are never closed completely but instead the eyelids form a slit which leaves a part of the pupil uncovered. The width of the slit between the pigeon' eyelids is highly sensitive to both, ambient luminance and the visual background against which seeds are offered. It was concluded that eyelid slits increase the focal depth of retinal images at extreme near-field viewing-conditions. Applying pharmacological methods we could confirm that pupil size and eyelid slit width are controlled through conjoint neuronal mechanisms. This shared neuronal network is particularly sensitive to drugs that affect dopamine receptors.

  10. An age-related deficit in spatial-feature reference memory in homing pigeons (Columba livia).

    Science.gov (United States)

    Coppola, Vincent J; Flaim, Mary E; Carney, Samantha N; Bingman, Verner P

    2015-03-01

    Age-related memory decline in mammals has been well documented. By contrast, very little is known about memory decline in birds as they age. In the current study we trained younger and older homing pigeons on a reference memory task in which a goal location could be encoded by spatial and feature cues. Consistent with a previous working memory study, the results revealed impaired acquisition of combined spatial-feature reference memory in older compared to younger pigeons. Following memory acquisition, we used cue-conflict probe trials to provide an initial assessment of possible age-related differences in cue preference. Both younger and older pigeons displayed a similarly modest preference for feature over spatial cues. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. When One Hemisphere Takes Control: Metacontrol in Pigeons (Columba livia)

    Science.gov (United States)

    Adam, Ruth; Güntürkün, Onur

    2009-01-01

    Background Vertebrate brains are composed of two hemispheres that receive input, compute, and interact to form a unified response. How the partially different processes of both hemispheres are integrated to create a single output is largely unknown. In some cases one hemisphere takes charge of the response selection – a process known as metacontrol. Thus far, this phenomenon has only been shown in a handful of studies with primates, mostly conducted in humans. Metacontrol, however, is even more relevant for animals like birds with laterally placed eyes and complete chiasmatic decussation since visual input to the hemispheres is largely different. Methodology/Principal Findings Homing pigeons (Columba livia) were trained with a color discrimination task. Each hemisphere was trained with a different color pair and therefore had a different experience. Subsequently, the pigeons were binocularly examined with two additional stimuli that combined the positive color of one hemisphere with a negative color that had been shown to the other, omitting the availability of a coherent solution and confronting the pigeons with a conflicting situation. Some of the pigeons responded to both stimuli, indicating that none of the hemispheres dominated the overall preference. Some birds, however, responded primarily to one of the conflicting stimuli, showing that they based their choice on the left- or right-monocularly learned color pair, indicating hemispheric metacontrol. Conclusions/Significance We could demonstrate for the first time that metacontrol is a widespread phenomenon that also exists in birds, and thus in principle requires no corpus callosum. Our results are closely similar to those in humans: monocular performance was higher than binocular one and animals displayed different modes of hemispheric dominance. Thus, metacontrol is a dynamic and widely distributed process that possibly constitutes a requirement for all animals with a bipartite brain to confront the

  12. When one hemisphere takes control: metacontrol in pigeons (Columba livia.

    Directory of Open Access Journals (Sweden)

    Ruth Adam

    Full Text Available Vertebrate brains are composed of two hemispheres that receive input, compute, and interact to form a unified response. How the partially different processes of both hemispheres are integrated to create a single output is largely unknown. In some cases one hemisphere takes charge of the response selection--a process known as metacontrol. Thus far, this phenomenon has only been shown in a handful of studies with primates, mostly conducted in humans. Metacontrol, however, is even more relevant for animals like birds with laterally placed eyes and complete chiasmatic decussation since visual input to the hemispheres is largely different.Homing pigeons (Columba livia were trained with a color discrimination task. Each hemisphere was trained with a different color pair and therefore had a different experience. Subsequently, the pigeons were binocularly examined with two additional stimuli that combined the positive color of one hemisphere with a negative color that had been shown to the other, omitting the availability of a coherent solution and confronting the pigeons with a conflicting situation. Some of the pigeons responded to both stimuli, indicating that none of the hemispheres dominated the overall preference. Some birds, however, responded primarily to one of the conflicting stimuli, showing that they based their choice on the left- or right-monocularly learned color pair, indicating hemispheric metacontrol.We could demonstrate for the first time that metacontrol is a widespread phenomenon that also exists in birds, and thus in principle requires no corpus callosum. Our results are closely similar to those in humans: monocular performance was higher than binocular one and animals displayed different modes of hemispheric dominance. Thus, metacontrol is a dynamic and widely distributed process that possibly constitutes a requirement for all animals with a bipartite brain to confront the problem of choosing between two hemisphere

  13. Esophagitis and enteritis caused by herpesvirus in pigeons.

    Directory of Open Access Journals (Sweden)

    Egobol, L.

    2002-01-01

    Full Text Available The pigeon squabs, aged 5-26 day-old, showed clinical signs of dullness, anorexia, indigestion, reten-tion of feed in crop, progressive emaciation then died. The morbidity rate and mortality rate were 7.14% (50/700. The adult pigeons did not show any signs of disease. From pathological finding, pharyngitis, esophagitis were found with diphtheritic membrane covering necrotic ulcers on the mucosa of pharynx, esophagus and crop. From histopathological findings, esophagitis with epithelial hyperplasia and sloughed, lamina propria mucosa edema with lymphoid cells infiltration were found in duodenum and jejunum. The intranuclear inclusion body, Cowdry type A, was found in epithelial mucosa of esophagus, enterocyte of jejunum and lymphoid cells in spleen. FA test to duck virus enteritis and inoculation to ducklings showed negative results. Electron microscopic study revealed electron dense core sized 146-167 nm., which was identified as herpesvirus.

  14. Radiation-induced alterations in succinate dehydrogenase activity in the muscle of pigeon

    International Nuclear Information System (INIS)

    Gadhia, P.K.; Shah, V.C.

    1983-01-01

    The histochemical changes in succinate dehydrogenase were investigated in pectoralis major muscle of pigeon exposed to sub-lethal dose (400 rad) of γ-irradiation. Biochemical study was also carried out after 200, 300 and 400 rad of irradiation. In the present study the overall decrease in enzyme activity could be due to the structural and/or functional damage to mitochondria after treatment of pigeon to different sub-lethal doses of γ-irradiation. The significance of these results has been discussed with special reference to oxidative metabolism. (author)

  15. Isolation and characterization of Ornithobacterium rhinotracheale in the commercial turkey, quail flocks and domestic pigeons by bacteriological and molecular methods

    Directory of Open Access Journals (Sweden)

    Banani, M.

    2011-12-01

    Full Text Available Ornithobacterium rhinotracheale (ORT is a respiratory pathogen which has been isolated throughout the world from numerous bird species. The present study was designed to isolate and characterize the ORT from domestic turkeys, quails and pigeons. For this purpose, 250 samples from each bird species (turkey, quail and pigeon with or without respiratory signs were tested by taking of tracheal swabs. In addition, respiratory tissue samples (tracheal and lung, from 250 slaughtered turkeys, 50 slaughtered quails and 100dead pigeons were also subjected to culture for ORT as tracheal swabs. Respiratory tissues were also tested for bacterial DNA by using polymerase chain reaction (PCR. In general, 30 isolates including 4 isolates from turkeys, 3 isolates from quails and 23 isolates from pigeons were identified as ORT by bacteriologicalmethod and then confirmed by PCR. Bacterial DNA was detected in 20%, 50% and 35% of respiratory tissues in turkeys, quails and pigeons respectively. Five ORT isolates from pigeon and all four isolates from turkey showed smaller colony size, while other isolates had larger colonies when cultured in blood agar. Fifty percent of the isolates with larger colony but none of the isolates with small colony size could agglutinate red blood cells (RBCs. All of the isolates were sensitive to danofloxacin and chloramphenicolwhile more than 90% of pigeon isolates were resistant to ampicillin. All of turkey and quail and 30% of pigeon isolates were resistant to tetracycline. Our ORT isolates showed high identity (98%- 100% insequence of 16S rRNA gene to related data in GeneBank.

  16. Detection of CHLAMYDIA PSITTACI in feral pigeons ( COLUMBA LIVIA DOMESTICA in Slovakia and their characterisation

    Directory of Open Access Journals (Sweden)

    Lenka Čechová

    2015-12-01

    Full Text Available [b]Introduction and objectives.[/b] [i]Chlamydia psittaci[/i], an obligate intracellular bacterium, which is the etiologic agent of avian chlamydiosis in birds and ornithosis/psittacosis in humans, has been reported to be one of the most common pathogens found in feral pigeons worldwide, and thus constitutes a zoonotic risk. The aim of the study was to investigate pigeons in Slovakia living in areas in close proximity to humans for the presence of C. psittaci, using pharyngeal and cloacal swabs. [b]Material and methods. [/b]122 clinically healthy pigeons from different geographical regions of Slovakia were examined for the presence of [i]C. psittaci[/i]. The adult pigeons of both genders were captured during the summer period in the urban centres of Slovakian towns. Each sample was examined by molecular method PCR, and in the case of positive result the identity of the obtained sequence was examined by a BLAST search. [b]Results.[/b] Of the total number of 244 examined samples, 14 (5.7% showed positivity for [i]C. psittaci[/i] infection, 5 of which were from pharyngeal swabs (4.1% and 9 from cloacal swabs (7.4%. A positive result was detected in 13 pigeons (10.7%. Phylogenetic analysis showed that all the positive samples are genetically very close to genotypes B and genotype E. [b]Conclusion.[/b] Phylogenetic examination of the 14 isolates of [i]C. psittaci[/i] identified in the presented study, based on 23S rRNA gene sequence, revealed their close relationship with [i]C. psittaci[/i] genotypes B and E. Both genotypes are predominantly prevalent in pigeons and both can be transmitted to humans. Therefore, it is necessary to perform screening examinations of animals and analyse the epidemiological factors affecting the way of transmission and circulation of pathogen.

  17. Effect of naloxone on food competition aggression in food-restricted high and low aggression pigeons (Columba livia

    Directory of Open Access Journals (Sweden)

    Fachinelli C.

    2004-01-01

    Full Text Available We determined the effect of the opiate receptor antagonist naloxone on aggression, emotion, feeder control, and eating behavior in high and low aggression female pigeons maintained at 80% of their normal weight and exposed to food competition interactions. Pigeons were divided into pairs by previously ranked high aggression (total time spent in offensive aggression exceeding 60 s/5 min; N = 6 pairs and low aggression females (time spent in offensive aggression less than 10 s/5 min; N = 6 pairs. A pigeon in each pair received an sc dose of naloxone (1 mg kg-1 ml saline-1 and the other animal received the vehicle. Trials (10 min were performed 30 min after the naloxone/vehicle administration. The naloxone group of high aggression pigeons showed lower scores of total time spent in offensive aggression (control: 98.6 ± 12.0; naloxone: 46.8 ± 6.6 s; P < 0.05 and higher scores of time spent in emotional responses (control: 3.5 ± 0.6; naloxone: 10.8 ± 2.4 s; P < 0.05 than controls. The other behaviors scored, feeder control and eating behavior, were not affected in this group. The naloxone group of low aggression pigeons, however, showed higher scores of offensive aggression than their controls (5.3 ± 1.3; naloxone: 28.7 ± 8.0 s; P < 0.05. The present results suggest that opiate receptor mechanisms are implicated in offensive aggression responses in high and low aggression pigeons. However, as reported for brain 5-hydroxytryptamine manipulation and GABA-A-benzodiazepine receptor manipulation, the effect of the opiate receptor antagonist on food competition aggression in pigeons was related to their pretreatment level of aggression.

  18. Monitoring for Pb and Cd pollution using feral pigeons in rural, urban, and industrial environments of Korea

    International Nuclear Information System (INIS)

    Nam, Dong-Ha; Lee, Doo-Pyo

    2006-01-01

    This study was aimed at evaluating the lead (Pb) and cadmium (Cd) contamination status using resident pigeons from rural (island), central urban (Seoul), and four industrial complex areas in Korea with varying traffic density as well as atmospheric metal pollution records. We also discussed the results with respect to metal exposure trends in urban area after introduction of lead-free gasoline in Korea. Mean concentrations of Pb and Cd in bone and kidney of pigeons from Seoul were comparable to those from industrial complex areas and were about 15-20 times those at the reference site. This suggests that exposure to metals in the urban environment is as high as in the industrial areas. Lead and Cd concentrations in lungs of pigeons from Seoul were significantly higher by more than three times in 2000 than in 1991 (p < 0.01), whereas the residues in liver, kidney, and bone remained at a similar level, despite the introduction of unleaded gasoline in 1993. The Pb and Cd concentrations in tissues of pigeons did not decrease as atmospheric metal levels decreased. Ingestion may be more important than inhalation in exposing pigeons to Pb and Cd in this study

  19. Monitoring for Pb and Cd pollution using feral pigeons in rural, urban, and industrial environments of Korea

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Dong-Ha [Laboratory for Animal Ecology, School of Environment and Applied Chemistry, Kyunghee University (Korea, Republic of); Lee, Doo-Pyo [Science of Biology, Department of Biological Science, Honam University (Korea, Republic of)]. E-mail: dplee@honam.ac.kr

    2006-03-15

    This study was aimed at evaluating the lead (Pb) and cadmium (Cd) contamination status using resident pigeons from rural (island), central urban (Seoul), and four industrial complex areas in Korea with varying traffic density as well as atmospheric metal pollution records. We also discussed the results with respect to metal exposure trends in urban area after introduction of lead-free gasoline in Korea. Mean concentrations of Pb and Cd in bone and kidney of pigeons from Seoul were comparable to those from industrial complex areas and were about 15-20 times those at the reference site. This suggests that exposure to metals in the urban environment is as high as in the industrial areas. Lead and Cd concentrations in lungs of pigeons from Seoul were significantly higher by more than three times in 2000 than in 1991 (p < 0.01), whereas the residues in liver, kidney, and bone remained at a similar level, despite the introduction of unleaded gasoline in 1993. The Pb and Cd concentrations in tissues of pigeons did not decrease as atmospheric metal levels decreased. Ingestion may be more important than inhalation in exposing pigeons to Pb and Cd in this study.

  20. Isolation and molecular characterization of Cryptococcus species isolated from pigeon nests and Eucalyptus trees.

    Science.gov (United States)

    Kamari, A; Sepahvand, A; Mohammadi, R

    2017-06-01

    Cryptococcus species are pathogenic and non-pathogenic basidiomycete yeasts that are found widely in the environment. Based on phenotypic methods, this genus has many species; however, its taxonomy is presently being re-evaluated by modern techniques. The Cryptococcus species complex includes two sibling taxa of Cryptococcus neoformans and Cryptococcus gattii . We aimed to investigate the possible distribution of Cryptococcus species in pigeon nests and Eucalyptus trees in Ilam, Iran, using molecular techniques. Two hundred and seventy-four specimens were collected from pigeon nests and Eucalyptus trees during 2016-2017. All the specimens were sub-cultured on Sabouraud Glucose Agar with chloramphenicol and bird seed agar. For molecular identification, the ITS15.8SITS2 rDNA region was amplified using the first and fourth internal transcribed spacer (ITS1 and ITS4, respectively) primers. The purified products were applied for cycle sequencing reactions in forward direction with ITS1 primer. The obtained results were analyzed with Chromas 2.3. Thirty-three out of 186 cultures (17.7%) and 11 out of 88 cultures (12.5%) were positive among pigeon nest and Eucalyptus tree specimens, respectively. Cryptococcus albidus (17.2%), C. albidus var. kuetzingii (3.4%), C. adeliensis (3.4%), C. uzbekistanensis (3.4%), and C. neoformans var. grubii (3.4%) were isolated from pigeon nests, and Cryptococcus adeliensis (25%) was the only Cryptococcus species isolated from Eucalyptus trees. The presence of pigeons and Eucalyptus trees in the vicinity of some particular places such as rest homes and hospitals should be considered as a risk factor for the immunocompromised population.

  1. Associative symmetry and stimulus-class formation by pigeons: the role of non-reinforced baseline relations.

    Science.gov (United States)

    Urcuioli, Peter J

    2010-10-01

    Two experiments tested the assumption of Urcuioli's (2008) theory of pigeons' equivalence-class formation that consistent non-reinforcement of certain stimulus combinations in successive matching juxtaposed with consistent reinforcement of other combinations generates stimulus classes containing the elements of the reinforced combinations. In Experiment 1, pigeons were concurrently trained on symbolic (AB) and two identity (AA and BB) successive tasks in which half of all identity trials ended in non-reinforcement but all AB trials were reinforced, contingent upon either responding or not responding to the comparisons. Subsequent symmetry (BA) probe trials showed evidence of symmetry in one of four pigeons. In Experiment 2, pigeons learned three pair-comparison tasks in which left versus right spatial choices were reinforced after the various sample-comparison combinations comprising AB, AA, and BB conditional discriminations. Non-differentially reinforced BA probe trials following acquisition showed some indication of symmetrical choice responding. The overall results contradict the theoretical predictions derived from Urcuioli (2008) and those from Experiment 2 challenge other stimulus-class analyses as well. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. PIGEON PEA (Cajanus cajan AN ALTERNATIVE IN THE FOOD INDUSTRY

    Directory of Open Access Journals (Sweden)

    Carmen Lucia Navarro V

    2014-12-01

    Full Text Available Due to the current situation of inadequate nutrition in the population of many countries, including Colombia. Search sources rich in proteins and low-cost alternatives. The pigeon pea (Cajanus cajan is an important legume that contain a mo derate amount of protein, calories, vitamins and minerals, its use in foods is limited by the presence of anti-nutritional factors, which can be reduced or eliminated through the use of treatments. The proteins have functional properties that can be take advantage in meat, dairy and bakery products. The purpose of this review is to present an overview of the skills nutritional and functional properties of pigeon pea application opportunities in various applications in the food industry.

  3. The effect of total-body γ-irradiation on pigeons

    International Nuclear Information System (INIS)

    Gadhia, P.K.; Shah, V.C.; Desai, R.

    1979-01-01

    A study of the effects of total-body 60 Coγ radiation (200 to 2000 rad) on the common pigeon (Columba livia) has indicated a LD 50/30 of 950 +- 50 rad. There were no deaths before 6 days and the peak frequency in average deaths occurred 9 days after irradiation. Most of the birds showed small changes in activity or behaviour in the first five days. A histopathological study was made of femoral bone marrow from irradiated (1000 rad) pigeons sacrificed 1 to 18 days post-irradiation. Slight aplasia was observed on the first day after irradiation, moderately marked on the third day and extensive on the fourth and fifth days. At the end of the second week regeneration was observed as the primitive lymphocyte-like cells were differentiating into granulocytes and erythrocytes. (UK)

  4. Post-precipitation bias in band-tailed pigeon surveys conducted at mineral sites

    Science.gov (United States)

    Overton, C.T.; Schmitz, R.A.; Casazza, Michael L.

    2005-01-01

    Many animal surveys to estimate populations or index trends include protocol prohibiting counts during rain but fail to address effects of rainfall preceding the count. Prior research on Pacific Coast band-tailed pigeons (Patagioenas fasciata monilis) documented declines in use of mineral sites during rainfall. We hypothesized that prior precipitation was associated with a short-term increase in use of mineral sites following rain. We conducted weekly counts of band-tailed pigeons at 19 Pacific Northwest mineral sites in 2001 and 20 sites in 2002. Results from regression analysis indicated higher counts ???2 days after rain (11.31??5.00% [x????SE]) compared to ???3 days. Individual index counts conducted ???2 days after rain were biased high, resulting in reduced ability to accurately estimate population trends. Models of band-tailed pigeon visitation rates throughout the summer showed increased mineral-site counts during both June and August migration periods, relative to the July breeding period. Our research supported previous studies recommending that mineral-site counts used to index the band-tailed pigeon population be conducted during July. We further recommend conducting counts >3 days after rain to avoid weather-related bias in index estimation. The design of other population sampling strategies that rely on annual counts should consider the influence of aberrant weather not only coincident with but also preceding surveys if weather patterns are thought to influence behavior or detection probability of target species.

  5. Pigeons Exhibit Contextual Cueing to Both Simple and Complex Backgrounds

    Science.gov (United States)

    Wasserman, Edward A.; Teng, Yuejia; Castro, Leyre

    2014-01-01

    Repeated pairings of a particular visual context with a specific location of a target stimulus facilitate target search in humans. We explored an animal model of this contextual cueing effect using a novel Cueing-Miscueing design. Pigeons had to peck a target which could appear in one of four possible locations on four possible color backgrounds or four possible color photographs of real-world scenes. On 80% of the trials, each of the contexts was uniquely paired with one of the target locations; on the other 20% of the trials, each of the contexts was randomly paired with the remaining target locations. Pigeons came to exhibit robust contextual cueing when the context preceded the target by 2 s, with reaction times to the target being shorter on correctly-cued trials than on incorrectly-cued trials. Contextual cueing proved to be more robust with photographic backgrounds than with uniformly colored backgrounds. In addition, during the context-target delay, pigeons predominately pecked toward the location of the upcoming target, suggesting that attentional guidance contributes to contextual cueing. These findings confirm the effectiveness of animal models of contextual cueing and underscore the important part played by associative learning in producing the effect. PMID:24491468

  6. Purification, crystallization and preliminary X-ray analysis of urease from pigeon pea (Cajanus cajan)

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, Anuradha; Ponnuraj, Karthe, E-mail: pkarthe@hotmail.com [Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2008-07-01

    Urease from pigeon pea was purified and crystallized and X-ray diffraction data were collected at 2.5 Å resolution. Urease is a seed protein that is common to most Leguminosae. It also occurs in many bacteria, fungi and several species of yeast. Urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide, thus allowing organisms to use exogenous and internally generated urea as a nitrogen source. Urease from pigeon pea seeds has been purified to electrophoretic homogeneity using a series of steps involving ammonium sulfate fractionation, acid precipitation, ion-exchange and size-exclusion chromatography techniques. The pigeon pea urease was crystallized and the resulting crystals diffracted to 2.5 Å resolution. The crystals belong to the rhombohedral space group R32, with unit-cell parameters a = b = 176.29, c = 346.44 Å.

  7. Purification, crystallization and preliminary X-ray analysis of urease from pigeon pea (Cajanus cajan)

    International Nuclear Information System (INIS)

    Balasubramanian, Anuradha; Ponnuraj, Karthe

    2008-01-01

    Urease from pigeon pea was purified and crystallized and X-ray diffraction data were collected at 2.5 Å resolution. Urease is a seed protein that is common to most Leguminosae. It also occurs in many bacteria, fungi and several species of yeast. Urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide, thus allowing organisms to use exogenous and internally generated urea as a nitrogen source. Urease from pigeon pea seeds has been purified to electrophoretic homogeneity using a series of steps involving ammonium sulfate fractionation, acid precipitation, ion-exchange and size-exclusion chromatography techniques. The pigeon pea urease was crystallized and the resulting crystals diffracted to 2.5 Å resolution. The crystals belong to the rhombohedral space group R32, with unit-cell parameters a = b = 176.29, c = 346.44 Å

  8. Determinants of injuries in passenger vessel accidents.

    Science.gov (United States)

    Yip, Tsz Leung; Jin, Di; Talley, Wayne K

    2015-09-01

    This paper investigates determinants of crew and passenger injuries in passenger vessel accidents. Crew and passenger injury equations are estimated for ferry, ocean cruise, and river cruise vessel accidents, utilizing detailed data of individual vessel accidents that were investigated by the U.S. Coast Guard during the time period 2001-2008. The estimation results provide empirical evidence (for the first time in the literature) that crew injuries are determinants of passenger injuries in passenger vessel accidents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Rapid direct identification of Cryptococcus neoformans from pigeon droppings by nested PCR using CNLAC1 gene.

    Science.gov (United States)

    Chae, H S; Park, G N; Kim, S H; Jo, H J; Kim, J T; Jeoung, H Y; An, D J; Kim, N H; Shin, B W; Kang, Y I; Chang, K S

    2012-08-01

    Isolation and identification of Cryptococcus neoformans and pathogenic yeast-like fungi from pigeon droppings has been taken for a long time and requires various nutrients for its growth. In this study, we attempted to establish a rapid direct identification method of Cr. neoformans from pigeon dropping samples by nested-PCR using internal transcribed spacer (ITS) CAP64 and CNLAC1 genes, polysaccharide capsule gene and laccase-associated gene to produce melanin pigment, respectively, which are common genes of yeasts. The ITS and CAP64 genes were amplified in all pathogenic yeasts, but CNLAC1 was amplified only in Cr. neoformans. The ITS gene was useful for yeast genotyping depending on nucleotide sequence. Homology of CAP64 genes among the yeasts were very high. The specificity of PCR using CNLAC1 was demonstrated in Cr. neoformans environmental strains but not in other yeast-like fungi. The CNLAC1 gene was detected in 5 serotypes of Cr. neoformans. The nested-PCR amplified up to 10(-11) μg of the genomic DNA and showed high sensitivity. All pigeon droppings among 31 Cr. neoformans-positive samples were positive and all pigeon droppings among 348 Cr. neoformans-negative samples were negative by the direct nested-PCR. In addition, after primary enrichment of pigeon droppings in Sabouraud dextrose broth, all Cr. neoformans-negative samples were negative by the nested-PCR, which showed high specificity. The nested-PCR showed high sensitivity without culture of pigeon droppings. Nested-PCR using CNLAC1 provides a rapid and reliable molecular diagnostic method to overcome weak points such as long culture time of many conventional methods.

  10. Detection of Chlamydophila psittaci from feral pigeons in environmental samples: problems with currently available techniques.

    Science.gov (United States)

    Geigenfeind, Ila; Haag-Wackernagel, Daniel

    2010-03-01

    Chlamydophila psittaci (Lillie, 1930) Everett et al., 1999, the pathogenic agent of human ornithosis, is widespread in feral pigeon populations and many cases of transmission from feral pigeons to humans have been reported. The aim of the present study was to detect C. psittaci in environmental samples to find out more about possible transmission routes and, therefore, to assess the zoonotic risk for humans. Fecal samples were collected from nest boxes in a feral pigeon loft. Additionally, samples were taken from the feather dust film covering the water surface of public fountains where pigeons regularly bathe. The samples were tested for the presence of chlamydial antigen using an antigen enzyme-linked immunosorbent assay to prove shedding of C. psittaci by feral pigeons. This test detects a genus specific lipopolysaccharide in the outer membrane of the chlamydial bacteria. Samples were tested using the IDEIA PCE Chlamydia Test kit (DakoCytomation) and positive results were verified with IDEIA Chlamydia Blocking Reagents (DakoCytomation). The IDEIA PCE Chlamydia Test yields a high proportion of positive results. However, when IDEIA Chlamydia Blocking was performed, most of the positive results turned out to be negative or could not be interpreted. We conclude that antigen-enzyme-linked immunosorbent assay tests are not suitable for detecting C. psittaci in environmental samples. Previous publications where no blocking test was used should be reconsidered critically. © 2010 ISZS, Blackwell Publishing and IOZ/CAS.

  11. International Passenger and Freight Report

    Data.gov (United States)

    Department of Transportation — The International Passenger and Freight report is a summarization of all passengers and all freight transported between the U.S. and foreign countries combined, with...

  12. An Analysis of an Autoclitic Analogue in Pigeons

    Science.gov (United States)

    Kuroda, Toshikazu; Lattal, Kennon A.; García-Penagos, Andrés

    2014-01-01

    Using a conditional discrimination procedure, pigeons were exposed to a nonverbal analogue of qualifying autoclitics such as "definitely" and "maybe." It has been suggested that these autoclitics are similar to tacts except that they are under the control of private discriminative stimuli. Instead of the conventional assumption…

  13. Telemedical Advice to Long Distance Passenger Ferries

    DEFF Research Database (Denmark)

    Jensen, Olaf Chresten; Bøggild, Niels Bo; Kristensen, Søren

    consultations with passenger ferries to identify areas for possible improvements. Methods: Data from the journals for one year from Radio Medical Denmark consultations with the medical Data from the journals for one year from Radio Medical Denmark consultations with the medical responsible officers on passenger...... ferries was analysed retrospectively. Results: Two hundred and fourteen RM records, 73% among passenger and 27% among crewmember Two hundred and fourteen RM records, 73% among passenger and 27% among crewmember patients were analysed. Passenger patients were generally older and more serious ill than...

  14. The orientation of homing pigeons (Columba livia f.d. with and without navigational experience in a two-dimensional environment.

    Directory of Open Access Journals (Sweden)

    Julia Mehlhorn

    Full Text Available Homing pigeons are known for their excellent homing ability, and their brains seem to be functionally adapted to homing. It is known that pigeons with navigational experience show a larger hippocampus and also a more lateralised brain than pigeons without navigational experience. So we hypothesized that experience may have an influence also on orientation ability. We examined two groups of pigeons (11 with navigational experience and 17 without in a standard operant chamber with a touch screen monitor showing a 2-D schematic of a rectangular environment (as "geometric" information and one uniquely shaped and colored feature in each corner (as "landmark" information. Pigeons were trained first for pecking on one of these features and then we examined their ability to encode geometric and landmark information in four tests by modifying the rectangular environment. All tests were done under binocular and monocular viewing to test hemispheric dominance. The number of pecks was counted for analysis. Results show that generally both groups orientate on the basis of landmarks and the geometry of environment, but landmark information was preferred. Pigeons with navigational experience did not perform better on the tests but showed a better conjunction of the different kinds of information. Significant differences between monocular and binocular viewing were detected particularly in pigeons without navigational experience on two tests with reduced information. Our data suggest that the conjunction of geometric and landmark information might be integrated after processing separately in each hemisphere and that this process is influenced by experience.

  15. The orientation of homing pigeons (Columba livia f.d.) with and without navigational experience in a two-dimensional environment.

    Science.gov (United States)

    Mehlhorn, Julia; Rehkaemper, Gerd

    2017-01-01

    Homing pigeons are known for their excellent homing ability, and their brains seem to be functionally adapted to homing. It is known that pigeons with navigational experience show a larger hippocampus and also a more lateralised brain than pigeons without navigational experience. So we hypothesized that experience may have an influence also on orientation ability. We examined two groups of pigeons (11 with navigational experience and 17 without) in a standard operant chamber with a touch screen monitor showing a 2-D schematic of a rectangular environment (as "geometric" information) and one uniquely shaped and colored feature in each corner (as "landmark" information). Pigeons were trained first for pecking on one of these features and then we examined their ability to encode geometric and landmark information in four tests by modifying the rectangular environment. All tests were done under binocular and monocular viewing to test hemispheric dominance. The number of pecks was counted for analysis. Results show that generally both groups orientate on the basis of landmarks and the geometry of environment, but landmark information was preferred. Pigeons with navigational experience did not perform better on the tests but showed a better conjunction of the different kinds of information. Significant differences between monocular and binocular viewing were detected particularly in pigeons without navigational experience on two tests with reduced information. Our data suggest that the conjunction of geometric and landmark information might be integrated after processing separately in each hemisphere and that this process is influenced by experience.

  16. Parents as passengers during pediatric transport.

    Science.gov (United States)

    Lewis, M M; Holditch-Davis, D; Brunssen, S

    1997-01-01

    The transport environment presents a unique setting in which the feasibility, advantages, and disadvantages of passengers accompanying a patient must be assessed carefully. The purpose of this study was to describe the current practice of including parents as passengers during pediatric interfacility transport. One-hundred-eighty-eight critical care transport programs in the United States responded to a voluntary mail survey, providing information about current policies, practices, and crew perceptions of the advantages and disadvantages of carrying parents as passengers. Extra seating for passengers was available in 96% of ambulances, 86% of fixed-wing aircraft, and 54% of helicopters used for pediatric transport. Parents traveled as passengers in all types of vehicles; most frequently in ambulances and fixed-wing aircraft. Twenty percent of helicopter programs allowed parent passengers on more than half of their pediatric transports in this vehicle. Advantages of parent passengers included emotional benefit for the parent and child, availability of parents for history and consent, good public relations, and having the parent present if the child dies. Disadvantages included potential parent anxiety, crew distraction, and space limitations. This study reflects the widely diverse policies, practices, and opinions relevant to this topic and confirms a need for further study.

  17. Improved Genome Assembly and Annotation for the Rock Pigeon (Columba livia).

    Science.gov (United States)

    Holt, Carson; Campbell, Michael; Keays, David A; Edelman, Nathaniel; Kapusta, Aurélie; Maclary, Emily; T Domyan, Eric; Suh, Alexander; Warren, Wesley C; Yandell, Mark; Gilbert, M Thomas P; Shapiro, Michael D

    2018-05-04

    The domestic rock pigeon ( Columba livia ) is among the most widely distributed and phenotypically diverse avian species. C. livia is broadly studied in ecology, genetics, physiology, behavior, and evolutionary biology, and has recently emerged as a model for understanding the molecular basis of anatomical diversity, the magnetic sense, and other key aspects of avian biology. Here we report an update to the C. livia genome reference assembly and gene annotation dataset. Greatly increased scaffold lengths in the updated reference assembly, along with an updated annotation set, provide improved tools for evolutionary and functional genetic studies of the pigeon, and for comparative avian genomics in general. Copyright © 2018 Holt et al.

  18. The effect of endoscopic sterilization on reproductive behavior and pair bond maintenance of feral pigeons (Columba livia).

    Science.gov (United States)

    Heiderich, E; Failing, K; Lierz, M; Schildger, B

    2016-01-01

    Problems related to feral pigeons (Columba livia) in cities mainly result from their large numbers due to uncontrolled population growth. The aim of this study was to evaluate whether endoscopic guided sterilization affects the reproductive behavior of feral pigeons under experimental conditions, with the intention of assessing this technique as a potential method for feral pigeon population control. Five groups of four pairs of feral pigeons each were studied from 8 weeks before, to 7 weeks after sterilization. Both the male and female of the first pair of each group were sterilized, in the second pair only the female and in the third pair only the male was sterilized. The fourth pair acted as a control. All eggs laid were candled to assess fertility. Surgical sterilization had minimal effects on behavior and therefore seems not to have impact on possible field application for population control. All pairs maintained their pair bonds and continued to defend their nesting sites against other pigeons. Only one female copulated with a foreign fertile male while her primary partner was debilitated due to surgery, but returned to him as soon as he recovered. All eggs laid more than 5 days after male sterilization were infertile, whereas all control pairs had fertile eggs. Only one fertile clutch was produced, 5 days after the male's sterilization. Therefore it is assumed that males remain fertile for a limited period of time. Endoscopic sterilization seems to be a promising method for field control of feral pigeon populations and sterilization of the male only seems sufficient.

  19. Dynamic Passenger Assignment during Disruptions in Railway Systems

    NARCIS (Netherlands)

    Zhu, Y.; Goverde, R.M.P.

    2017-01-01

    Passenger-oriented rescheduling problems receive increasing attention. However, the passenger assignment models used for evaluating the rescheduling solutions are usually simplified by many assumptions. To estimate passenger inconvenience more accurately, this paper establishes a dynamic passenger

  20. Faunal extinction and human habitation in New Caledonia : initial results and implications of new research at the Pindai Caves

    International Nuclear Information System (INIS)

    Anderson, A.; Sand, C.; Petchey, F.; Worthy, T.H.

    2010-01-01

    Archaeological and palaeontological investigations occurred in 2003 at the Pindai Caves in New Caledonia, where remains of prehistoric settlement exist in conjunction with the richest fossil deposits found to date on Grand Terre. Among more than 45 bird taxa in our excavations at least 20 that are locally or globally extinct are represented at levels immediately below or within the era of human occupation. These include the giant megapode, Sylviornis sp., the flightless swamphen, Porphyrio kukuwiedei, and other rails, a kagu, pigeons, a large snipe, Coenocorypha sp., several taxa of owls, a nightjar, and an owlet-nightjar. Unresolved problems in dating and taphonomy, however, make it difficult to specify the strength of cultural associations and thus the extent to which human activities were responsible for extinctions or extirpations. We present the first radiocarbon dates upon Sylviornis bone, showing that, at least, the species survived into the late Holocene. Relatively frequent occurrence of Sylviornis bone in the cultural levels, coupled with a radiocarbon date on a bone sample of about 3000 calBP make a case for human contact. (author). Refs., 8 figs., 6 tabs.

  1. Access improvement to aircraft passengers' hand luggage.

    Science.gov (United States)

    Alberda, W; Kampinga, O; Kassels, R; van Kester, R; Noriega, J; Vink, P

    2015-01-01

    Efficient use of space and passenger comfort in aircraft interiors are major issues. There is not much research available about the flying experience regarding passengers' personal belongings. The objective of this study is to explore concepts within the current aircraft seats which improve the passenger experience related to their personal belongings like wallets, mobile phones and laptops. Through on-site observations, interviews and online questionnaires, data regarding the number of personal belongings taken into the airplane and opinions about access to hand luggage were gathered. These data were used to develop different concepts to optimize the aircraft interior, which were evaluated by passengers. Almost every passenger carries a phone (88%), wallet (94%), travel documents (98%) and keys (76%) with them and they like to have these stored close by. Passengers rate the concept that provides integrated storage in the tray table of the aircraft seat the best. Extra storage possibility in the table-tray seems a promising solution according to the passengers.

  2. An outbreak of toxoplasmosis in an aviary collection of Nicobar pigeons (Caloenas nicobaria : clinical communication

    Directory of Open Access Journals (Sweden)

    R.D. Last

    2008-05-01

    Full Text Available Three out of 10 Nicobar pigeons (Caloenas nicobaria in an aviary collection in South Africa were found dead with no presenting clinical symptoms. Histological examination of formalin-fixed tissues from all these birds revealed necrotic foci in various visceral organs (liver, spleen, heart, kidney and lungs, plus diffuse pulmonary congestion and oedema with vasculitis. Numerous protozoal tachyzoites were present in all organs and there was strong positive immunohistochemical (IHC labelling of these organisms for Toxoplasma gondii. Pathology was consistent with acute systemic toxoplasmosis as a consequence of oocyst ingestion. Feral cats were known to be a problem at the facility. Clinical toxoplasmosis is rarely reported in pigeons and this is believed to be the 1st report of toxoplasmosis in Nicobar pigeons.

  3. When good pigeons make bad decisions: Choice with probabilistic delays and outcomes.

    Science.gov (United States)

    Pisklak, Jeffrey M; McDevitt, Margaret A; Dunn, Roger M; Spetch, Marcia L

    2015-11-01

    Pigeons chose between an (optimal) alternative that sometimes provided food after a 10-s delay and other times after a 40-s delay and another (suboptimal) alternative that sometimes provided food after 10 s but other times no food after 40 s. When outcomes were not signaled during the delays, pigeons strongly preferred the optimal alternative. When outcomes were signaled, choices of the suboptimal alternative increased and most pigeons preferred the alternative that provided no food after the long delay despite the cost in terms of obtained food. The pattern of results was similar whether the short delays occurred on 25% or 50% of the trials. Shortening the 40-s delay to food sharply reduced suboptimal choices, but shortening the delay to no food had little effect. The results suggest that a signaled delay to no food does not punish responding in probabilistic choice procedures. The findings are discussed in terms of conditioned reinforcement by signals for good news. © Society for the Experimental Analysis of Behavior.

  4. The pigeon's discrimination of visual entropy: a logarithmic function.

    Science.gov (United States)

    Young, Michael E; Wasserman, Edward A

    2002-11-01

    We taught 8 pigeons to discriminate 16-icon arrays that differed in their visual variability or "entropy" to see whether the relationship between entropy and discriminative behavior is linear (in which equivalent differences in entropy should produce equivalent changes in behavior) or logarithmic (in which higher entropy values should be less discriminable from one another than lower entropy values). Pigeons received a go/no-go task in which the lower entropy arrays were reinforced for one group and the higher entropy arrays were reinforced for a second group. The superior discrimination of the second group was predicted by a theoretical analysis in which excitatory and inhibitory stimulus generalization gradients fall along a logarithmic, but not a linear scale. Reanalysis of previously published data also yielded results consistent with a logarithmic relationship between entropy and discriminative behavior.

  5. Prospective and retrospective timing by pigeons.

    Science.gov (United States)

    Fetterman, J Gregor; Killeen, P Richard

    2010-05-01

    Pigeons discriminated between two pairs of durations: a short set (2.5 and 5 sec) and a long set (5 and 10 sec). The pairs were intermixed within sessions and identified by the colors on the signal and choice keys. Once the task was learned, the pigeons experienced the following three conditions seriatim: (1) The signal key was made ambiguous about the test change, but the choice keys were informative (retrospective); (2) the signal key identified the test range, but the choice keys did not (prospective); (3) probe trials were introduced in which the color of the center key signaled one test range, but the color of the choice keys signaled the other test range (inconsistent). Accuracy of choice decreased in the retrospective condition and, returned to baseline levels, was higher under the prospective condition than under the retrospective condition. In a final condition, referred to as conflict trials, the center-key color signified one test range and the choice-key colors the other range. The results from these conflict-inconsistent tests indicate that choice behavior was largely controlled by the signal-key color and not by the choice-key color. We relate these findings to different approaches to timing in animals.

  6. Network structure of subway passenger flows

    Science.gov (United States)

    Xu, Q.; Mao, B. H.; Bai, Y.

    2016-03-01

    The results of transportation infrastructure network analyses have been used to analyze complex networks in a topological context. However, most modeling approaches, including those based on complex network theory, do not fully account for real-life traffic patterns and may provide an incomplete view of network functions. This study utilizes trip data obtained from the Beijing Subway System to characterize individual passenger movement patterns. A directed weighted passenger flow network was constructed from the subway infrastructure network topology by incorporating trip data. The passenger flow networks exhibit several properties that can be characterized by power-law distributions based on flow size, and log-logistic distributions based on the fraction of boarding and departing passengers. The study also characterizes the temporal patterns of in-transit and waiting passengers and provides a hierarchical clustering structure for passenger flows. This hierarchical flow organization varies in the spatial domain. Ten cluster groups were identified, indicating a hierarchical urban polycentric structure composed of large concentrated flows at urban activity centers. These empirical findings provide insights regarding urban human mobility patterns within a large subway network.

  7. Chlamydia psittaci and C. avium in feral pigeon (Columba livia domestica) droppings in two cities in the Netherlands.

    Science.gov (United States)

    Burt, Sara A; Röring, Romy E; Heijne, Marloes

    2018-06-05

    Feral pigeons (Columba livia domestica) live and breed in many city centres and contact with their droppings can be a hazard for human health if the birds carry Chlamydia psittaci. The aim of this study was to establish whether pigeon droppings in two Dutch cities (Utrecht and Haarlem) contain C. psittaci and/or C. avium, which could be a potential hazard for transmission to humans. In May 2017 seven feral pigeon 'hot spots' with between 5 and 40+ pigeons present were identified in two cities by visual observations over two days. During the following ten days fresh droppings were collected at these hot spots and the samples were pooled per three droppings to achieve 40-41 samples per city. Samples were analysed for Chlamydia DNA with a broad range 23S Chlamydiaceae Real-Time PCR and positive samples were tested with a specific C. psittaci and C. avium Real-Time PCR. Positive C. psittaci samples were genotyped. C. psittaci and C. avium were detected in both cities. For C. psittaci the prevalences in Utrecht and Haarlem were 2.4% and 7.5%, respectively; for C. avium 36.6% and 20.0%, respectively. One sample contained both species. All C. psittaci samples belonged to genotype B. C. psittaci and C. avium are present in feral pigeon droppings in Utrecht and Haarlem. Human contact with droppings from infected pigeons or inhalation of dust from dried droppings represent a potential hazard to public health.

  8. Teen Drivers' Perceptions of Their Peer Passengers: Qualitative Study.

    Science.gov (United States)

    Ehsani, Johnathon P; Haynie, Denise L; Luthers, Christina; Perlus, Jessamyn; Gerber, Eli; Ouimet, Marie Claude; Klauer, Sheila G; Simons-Morton, Bruce

    The presence of peer passengers increases teenage drivers' fatal crash risk. Distraction and social influence are the two main factors that have been associated with increased risk. Teen drivers' perceptions of their peer passengers on these factors could inform our understanding of the conditions under which peer passengers increase crash risk or promote safer driving. The purpose of this study was to examine teen drivers' perceptions of their peer passengers on distraction and social influence. A convenience sample of male and female drivers participated in a semi-structured interview that included questions on their perceptions of the effects of peer passengers on driving on distraction and social influence. The analysis of the interviews was guided by a grounded theory approach. Teenage drivers were aware of the risk that peer passengers posed. Some described having passengers in the vehicle as distracting, and recognized that the level of distraction increased with the number of passengers in the vehicle. Drivers that felt responsible for the safety of their peer passengers described strategies they used to control the in-vehicle environment. Drivers described driving with passengers as a performance, and articulated direct and indirect sources of pressure, gender norms, and unspoken expectations of their passengers as influencing their driving behavior. The influence of passengers is situation specific and dependent on whom the passenger(s) may be. Passenger influence may be either protective or harmful, depending on the circumstances. Some passengers exert direct influence, but often their influence appears more indirect and subtle.

  9. A First Report of Infestation by Pseudolynchia canariensis in a Herd of Pigeons in Shahrekord (Southwest of Iran)

    Science.gov (United States)

    Pirali-Kheirabadi, Khodadad; Dehghani-Samani, Amir; Ahmadi-Baberi, Nader; Najafzadeh, Vida

    2016-01-01

    Background: Pigeons (Columba livia) have been kept as pet and reared for food in several countries including Iran. Ectoparasites are regarded as the basic causes of retardation in growth, lowered vitality and poor conditions of the birds. Pseudolynchia canariensis a hippoboscidae fly is one of the important ectoparasites of pigeons and is responsible for the transmission of pathogens to birds and humans same as pathogenic protozoan Haemoproteus columbae. Methods: A herd of domestic pigeons contained 50 pigeons in Shahrekord, southwest Iran was evaluated clinically infested by ectoparasites. Ectoparasites were removed. The samples were collected and then referred to the Laboratory of Parasitology of Shahrekord University, Shahrekord, Iran. Results: Usin diagnostic key for diptera fly, these flies were find P. canariensis. This is a rare report of infestation of pigeons herd by P. canariensis in Iran. The infestation rate was 40% that rate of infestation in pipers was more than females and in females was more than males. Conclusion: The rate of infested pipers was more than adults that maybe the less potential of pipers in removing of ectoparasites is reason of this higher rate. PMID:27308301

  10. A First Report of Infestation by Pseudolynchia canariensis in a Herd of Pigeons in Shahrekord (Southwest of Iran

    Directory of Open Access Journals (Sweden)

    Khodadad Pirali-Kheirabadi

    2016-01-01

    Full Text Available Background: Pigeons (Columba livia have been kept as pet and reared for food in several countries including Iran. Ectoparasites are regarded as the basic causes of retardation in growth, lowered vitality and poor conditions of the birds. Pseudolynchia canariensis a hippoboscidae fly is one of the important ectoparasites of pigeons and is respon­sible for the transmission of pathogens to birds and humans same as pathogenic protozoan Haemoproteus columbae.Methods: A herd of domestic pigeons contained 50 pigeons in Shahrekord, southwest Iran was evaluated clinically infested by ectoparasites. Ectoparasites were removed. The samples were collected and then referred to the Laboratory of Parasitology of Shahrekord University, Shahrekord, Iran.Results: Usin diagnostic key for diptera fly, these flies were find P. canariensis. This is a rare report of infestation of pigeons herd by P. canariensis in Iran. The infestation rate was 40% that rate of infestation in pipers was more than females and in females was more than males.Conclusion: The rate of infested pipers was more than adults that maybe the less potential of pipers in removing of ectoparasites is reason of this higher rate.

  11. An Adaptive Agent-Based Model of Homing Pigeons: A Genetic Algorithm Approach

    Directory of Open Access Journals (Sweden)

    Francis Oloo

    2017-01-01

    Full Text Available Conventionally, agent-based modelling approaches start from a conceptual model capturing the theoretical understanding of the systems of interest. Simulation outcomes are then used “at the end” to validate the conceptual understanding. In today’s data rich era, there are suggestions that models should be data-driven. Data-driven workflows are common in mathematical models. However, their application to agent-based models is still in its infancy. Integration of real-time sensor data into modelling workflows opens up the possibility of comparing simulations against real data during the model run. Calibration and validation procedures thus become automated processes that are iteratively executed during the simulation. We hypothesize that incorporation of real-time sensor data into agent-based models improves the predictive ability of such models. In particular, that such integration results in increasingly well calibrated model parameters and rule sets. In this contribution, we explore this question by implementing a flocking model that evolves in real-time. Specifically, we use genetic algorithms approach to simulate representative parameters to describe flight routes of homing pigeons. The navigation parameters of pigeons are simulated and dynamically evaluated against emulated GPS sensor data streams and optimised based on the fitness of candidate parameters. As a result, the model was able to accurately simulate the relative-turn angles and step-distance of homing pigeons. Further, the optimised parameters could replicate loops, which are common patterns in flight tracks of homing pigeons. Finally, the use of genetic algorithms in this study allowed for a simultaneous data-driven optimization and sensitivity analysis.

  12. Zoonotic Agents in Feral Pigeons (Columba livia) from Costa Rica: Possible Improvements to Diminish Contagion Risks.

    Science.gov (United States)

    Torres-Mejía, Ana María; Blanco-Peña, Kinndle; Rodríguez, César; Duarte, Francisco; Jiménez-Soto, Mauricio; Esperón, Fernando

    2018-01-01

    Most studies on zoonotic agents in pigeons have been conducted in the Palearctic region, but the scarcity of data is notorious in the Neotropical region, where these birds can breed all year around and are in close contact with humans. In this study, we used a combination of culture-dependent and culture-independent methods to identify infectious agents in 141 fecal samples from pigeons collected at four urban parks from Costa Rica. Of these we identified 34 positive samples for Salmonella enterica subsp. enterica serovar Braenderup (24.1%), 13 for Chlamydophila psittaci (9.2%), 9 for enteropathogenic Escherichia coli (6.4% eaeA, 0% stx-1 and 0% stx-2), and 2 for Campylobacter jejuni (1.4%). These populations of pigeons pose low risk for healthy adult humans, however, they may pose a health risk to immunocompromised patients or children. This study provides scientific data, which can be incorporated into educational programs aiming to reverse the public attitude toward pigeon feeding and to rationally justify population control efforts.

  13. Temporal Dynamics of Recovery from Extinction Shortly after Extinction Acquisition

    Science.gov (United States)

    Archbold, Georgina E.; Dobbek, Nick; Nader, Karim

    2013-01-01

    Evidence suggests that extinction is new learning. Memory acquisition involves both short-term memory (STM) and long-term memory (LTM) components; however, few studies have examined early phases of extinction retention. Retention of auditory fear extinction was examined at various time points. Shortly (1-4 h) after extinction acquisition…

  14. Mathematical modeling of an urban pigeon population subject to local management strategies.

    Science.gov (United States)

    Haidar, I; Alvarez, I; Prévot, A C

    2017-06-01

    This paper addresses the issue of managing urban pigeon population using some possible actions that make it reach a density target with respect to socio-ecological constraints. A mathematical model describing the dynamic of this population is introduced. This model incorporates the effect of some regulatory actions on the dynamic of this population. We use mathematical viability theory, which provides a framework to study compatibility between dynamics and state constraints. The viability study shows when and how it is possible to regulate the pigeon population with respect to the constraints. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Metabolic products in pigeon tissues after feeding glucose

    NARCIS (Netherlands)

    Reinking, A.; Steyn-Parvé, Elizabeth P.

    1964-01-01

    [14C6]Glucose was given orally to pigeons. After 3 h, the state—other than glycogen or fatty acids—in which radioactive carbon was present in the tissues was investigated. Nearly all the radioactive material could be extracted with 5% trichloroacetic acid. Most of the label thus extracted was

  16. Effects of pigeon pea and plantain starches on the compressional, mechanical, and disintegration properties of paracetamol tablets.

    Science.gov (United States)

    Dare, Kunle; Akin-Ajani, Dorothy O; Odeku, Oluwatoyin A; Itiola, Oludele A; Odusote, Omotunde M

    2006-03-01

    A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T--a measure of bond strength) and brittle fracture index (BFI--a measure of lamination tendency). The ranking for the mean yield pressure, P(y), for the formulations containing the different starches was generally corn plasticity, was pigeon pea plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.

  17. DEVELOPMENT OF PIGEON PEA INOCULATED WITH RHIZOBIUM ISOLATED FROM COWPEA TRAP HOST PLANTS

    Directory of Open Access Journals (Sweden)

    SALOMÃO LIMA GUIMARÃES

    2016-01-01

    Full Text Available Pigeon pea is an important protein source grown in several tropical and sub - tropical countries, and is considered a multi - purpose plant that is resistant to the conditions of the Brazilian Cerrado. Among the possible uses for cowpea, its use as a green manure, increasing soil nitrogen content through the association with diazotrophic bacteria, generically known as rhizobia, is noteworthy. The present work aimed to evaluate the efficiency of Rhizobium strains isolated from cowpea plants in the development of pigeon peas cultured in Red Latosol. The experiment was conducted in a greenhouse, using a completely randomized design with seven treatments and four replications. Treatments consisted of inoculation with four Rhizobium strains (MT8, MT15, MT16, and MT23 and one commercial inoculant comprising Bradyrhizobium spp. strains BR 2801 and BR 2003. There were two controls, one absolute (without inoculation or nitrogen fertilization and the other with nitrogen fertilization. Each experimental plot consisted of an 8 - dm 3 vase containing three plants. Analyzed variables included plant height, SPAD index, number and dry weight of nodules, and shoot and root dry masses. Pigeon peas responded significantly to inoculation treatment, since all the plants inoculated with Rhizobium strains isolated from cowpea strains showed results similar to plants in the nitrogen control and commercial inoculant treatments. This demonstrates a favorable plant – bacteria interaction, which can be utilized as an alternative nitrogen source for pigeon peas.

  18. 46 CFR 115.910 - Passenger Ship Safety Certificate.

    Science.gov (United States)

    2010-10-01

    ...) The route specified on the Certificate of Inspection and the SOLAS Passenger Ship Safety Certificate... 46 Shipping 4 2010-10-01 2010-10-01 false Passenger Ship Safety Certificate. 115.910 Section 115... MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS INSPECTION AND...

  19. Effect of isolation techniques on the characteristics of pigeon pea (Cajanus cajan) protein isolates.

    Science.gov (United States)

    Adenekan, Monilola K; Fadimu, Gbemisola J; Odunmbaku, Lukumon A; Oke, Emmanuel K

    2018-01-01

    In this study, the effect of different isolation techniques on the isolated proteins from pigeon pea was investigated. Water, methanol, ammonium sulfate, and acetone were used for the precipitation of proteins from pigeon pea. Proximate composition, and antinutritional and functional properties of the pigeon pea flour and the isolated proteins were measured. Data generated were statistically analyzed. The proximate composition of the water-extracted protein isolate was moisture 8.30%, protein 91.83%, fat 0.25%, ash 0.05%, and crude fiber 0.05%. The methanol-extracted protein isolate composition was moisture 7.87%, protein 91.83%, fat 0.17%, and ash 0.13%, while crude fiber and carbohydrates were not detected. The composition of the ammonium sulfate-extracted protein isolate was moisture 7.73%, protein 91.73%, fat 0.36, ash 0.13%, and crude fiber 0.67%. The acetone-extracted protein isolate composition was moisture 8.03%, protein 91.50%, ash 0.67%, and fat 0.30%, but crude fiber and carbohydrates were not detected. The isolate precipitated with ammonium sulfate displayed the highest foaming capacity (37.63%) and foaming stability (55.75%). Isolates precipitated with methanol and acetone had the highest water absorption capacity (160%). Pigeon pea protein isolates extracted with methanol and ammonium sulfate had the highest oil absorption capacity of 145%. Protein isolates recovered through acetone and methanol had the highest emulsifying capacity of 2.23% and emulsifying stability of 91.47%, respectively. The proximate composition of the recovered protein isolates were of high purity. This shows the efficiency of the extraction techniques. The isolates had desirable solubility index. All the isolation techniques brought significant impact on the characteristics of the isolated pigeon pea protein.

  20. Evaluation of Pigeon Pea Lines for Biological Soil Decompaction

    Directory of Open Access Journals (Sweden)

    Rodolfo Godoy

    2009-01-01

    Full Text Available Soil decompaction is generally achieved through mechanical cultivation practices; however biological processes can significantly add to this process through root growth, development, and later senescence. This study was carried out in Piracicaba, SP, Brazil and had the purpose of selecting, among forty one pure pigeon pea lines, the most efficient genotypes that promote soil decompaction by roots penetrating compacted soil layers. Utilizing artificially compacted 30 mm high soil blocks, in a series of experiments, these lines were compared to the cultivar Fava Larga taken as a standard. Three lines were preliminarily selected out of the initial group, and afterwards, in more detailed screenings by monitoring soil resistance to penetration and also evaluating the behavior of Tanzania grass plants seeded after pigeon pea, two of them, g5-94 and g8-95, were selected as possessing the most fit root system to penetrate compacted soil layers.

  1. Rethinking Extinction

    Science.gov (United States)

    Dunsmoor, Joseph E.; Niv, Yael; Daw, Nathaniel; Phelps, Elizabeth A.

    2015-01-01

    Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavioral technique, and consider whether traditional understandings warrant a re-examination. We discuss the neurobiology, cognitive factors, and major computational theories, and revisit the predominant view that extinction results in new learning that interferes with expression of the original memory. Additionally, we reconsider the limitations of extinction as a technique to prevent the relapse of maladaptive behavior, and discuss novel approaches, informed by contemporary theoretical advances, that augment traditional extinction methods to target and potentially alter maladaptive memories. PMID:26447572

  2. Effect of Pigeon Pea Hedgerow Alley Management on the Growth ...

    African Journals Online (AJOL)

    year (2010 and 2011 cropping seasons) field investigation conducted at the National Root Crops Research Institute, Umudike, South Eastern Nigeria. Treatments comprised three pigeon pea hedgerow alley populations of 20,000, 33,333 and ...

  3. Procrastination in the pigeon: Can conditioned reinforcement increase the likelihood of human procrastination?

    Science.gov (United States)

    Zentall, Thomas R; Case, Jacob P; Andrews, Danielle M

    2017-11-29

    Procrastination is the tendency to put off initiation or completion of a task. Although people are typically known to procrastinate, recent research suggests that they sometimes "pre-crastinate" by initiating a task sooner than they need to (Rosenbaum et al. in Psychological Science, 25(7), 1487-1496, 2014). A similar finding of precrastination was reported by Wasserman and Brzykcy (Psychonomic Bulletin & Review, 22, 1130-1134, 2015) with pigeons using a somewhat different procedure. In the present experiment, we used a procedure with pigeons that was more similar to the procedure used by Rosenbaum et al. Pigeons were given a choice between two sequences of events (concurrent chains). Choice of the procrastination chain resulted in color A, which 15-s later would change to color B and 5-s later resulted in reinforcement. Choice of the precrastination chain resulted in color C, which 5-s later would change to color D and 15-s later resulted in reinforcement. Thus, both chains led to reinforcement after 20 s. Results indicated that the pigeons procrastinated. That is, they preferred the 15-5 chain over the 5-15 chain. The results are consistent with Fantino's (Journal of the Experimental Analysis of Behavior, 12, 723-730, 1969) delay reduction theory, which posits that stimuli that signal a reduction in the delay to reinforcement, such as the 5-s stimulus that occurred immediately prior to reinforcement, serve as strong conditioned reinforcers and should be preferred. In support of this theory, the pigeons pecked most at the 5-s stimulus that led immediately to reinforcement, indicating that it had become a strong conditioned reinforcer. The results suggest that delay reduction theory, a theory that emphasizes the attraction to stimuli that predict reinforcement with a short delay, also may contribute to human procrastination behavior because when task completion comes just before the deadline, it may become a stronger conditioned reinforcer than if task completion

  4. Seasonal atmospheric extinction

    International Nuclear Information System (INIS)

    Mikhail, J.S.

    1979-01-01

    Mean monochromatic extinction coefficients at various wavelengths at the Kottamia Observatory site have shown the existence of a seasonal variation of atmospheric extinction. The extinction of aerosol compontnts with wavelengths at winter represent exceedingly good conditions. Spring gives the highest extinction due to aerosol. (orig.)

  5. Autoshaping as a psychophysical paradigm: Absolute visual sensitivity in the pigeon

    Science.gov (United States)

    Passe, Dennis H.

    1981-01-01

    A classical conditioning procedure (autoshaping) was used to determine absolute visual threshold in the pigeon. This method provides the basis for a standardized visual psychophysical paradigm. PMID:16812228

  6. Development and small-scale validation of a novel pigeon-associated mitochondrial DNA source tracking marker for the detection of fecal contamination in harvested rainwater.

    Science.gov (United States)

    Waso, M; Khan, S; Khan, W

    2018-02-15

    The current study was aimed at designing and validating (on a small-scale) a novel pigeon mitochondrial DNA (mtDNA) microbial source tracking (MST) marker for the detection of pigeon fecal matter in harvested rainwater. The pigeon mtDNA MST marker was designed to target the mtDNA Cytochrome b gene by employing mismatch amplification mutation assay kinetics. The pigeon marker was validated by screening 69 non-pigeon and 9 pigeon fecal samples. The host-sensitivity of the assay was determined as 1.00 while the host-specificity of the assay was 0.96. Harvested rainwater samples (n=60) were screened for the prevalence of the marker with the mtDNA Cytochrome b marker detected in 78% of the samples. Bayes' theorem was applied to calculate the conditional probability of the marker detecting true pigeon contamination and the marker subsequently displayed a 99% probability of detecting true pigeon contamination in the harvested rainwater samples. In addition, the mtDNA Cytochrome b marker displayed high concurrence frequencies versus heterotrophic bacteria (78.3%), E. coli (73.3%), total coliforms (71.1%) and fecal coliforms (66.7%). This study thus validates that targeting mtDNA for the design of source tracking markers may be a valuable tool to detect avian fecal contamination in environmental waters. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. PASSENGER FLOWS PREDICTION IN MAJOR TRANSPORTATION HUBS

    Directory of Open Access Journals (Sweden)

    O. O. Ozerova

    2013-11-01

    Full Text Available Purpose. An effective organization of passenger traffic, due to the reliability prediction of traffic flow in passenger transport hubs. In order to determine the parameters of prospective passenger transport areas it is essential to analyze the impact of various factors and determine the most influential ones. Methodology. The article presents the method of paired linear correlation for a more influential factors on passengers in intercity and commuter and possible use in predicting the linear regression equations. Passenger transport vessel areas and branches of industry are interconnected and are in the ratio of passengers and production. Findings. It is found that the coefficient of correlation is in complex dependence on the duration of the period of retrospective analysis. Evaluation of reliability correlation coefficients and coefficients of predictive models led to the conclusion that the population gives the most accurate prediction of passenger flows, providing account of changes in Ukraine during the period of transformation. Originality. Equations of dependence on the impact of macroeconomic indicators were obtained and the evaluation of the reliability results was received. Practical value. The results of analysis and calculations will make short-term forecasting of traffic flow.

  8. Nutritional characteristics of two pigeon pea hybrids – Liming and phosphated fertilization

    Directory of Open Access Journals (Sweden)

    Marcia Atauri Cardelli de Lucena

    2012-12-01

    Full Text Available The use of legumes in animal production systems can be a sustainable alternative as a protein source in rotational grazing system and/or as a protein bank. Pigeon pea (Cajanus cajan (L. Millsp. figure as an example of success of this use on animal nutrition. The development of this species can be limited by the high acidity and low soil phosphorus content. There is a lack of scientific information on the effects of liming and phosphorus fertilization on some nutritional variables of two pigeon pea new hybrids. This study was conducted in pots containing 5 kg of soil in a greenhouse at the Instituto de Zootecnia, Nova Odessa, São Paulo State. There were studied two pigeon pea hybrids, H1 and H2, and the treatments involved agronomic practices: 1 No liming and without phosphorus (control, 2 Liming (L, 3 Phosphorus fertilization (P and 4 Liming plus phosphorus. Liming was proposed to increase soil base saturation to 50%, it was used dolomite lime PRNT = 90%, in an amount corresponding to 4.5 t/ha. Phosphorus fertilization (as superphosphate rate was 60 kg/ha of PO25. The experimental units were allocated according to a complete randomised block design, with five replications. We analyzed the levels of crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF, in pigeon pea shoot at 45 days of age. Statistical analyzes were performed using the software SISVAR, averages were compared using test for multiple comparisons Student Newman-Keuls - SNK test (P < 0.05. The H1 hybrid had the highest content of CP, by applying P, lime plus P and the control treatment compared to H2 hybrid. The association lime plus P resulted in higher content of CP mainly due to the increased availability of P for plants. Smaller values were observed for NDF in H2 with P application. Lower values of ADF were observed in H1 in both control treatment and P application. The ADF values were lower for the hybrid H2 only for the treatment lime plus P. The two

  9. Who are the real bird brains? Qualitative differences in behavioral flexibility between dogs (Canis familiaris) and pigeons (Columba livia).

    Science.gov (United States)

    Laude, Jennifer R; Pattison, Kristina F; Rayburn-Reeves, Rebecca M; Michler, Daniel M; Zentall, Thomas R

    2016-01-01

    Pigeons given a simultaneous spatial discrimination reversal, in which a single reversal occurs at the midpoint of each session, consistently show anticipation prior to the reversal as well as perseveration after the reversal, suggesting that they use a less effective cue (time or trial number into the session) than what would be optimal to maximize reinforcement (local feedback from the most recent trials). In contrast, rats (Rattus norvegicus) and humans show near-optimal reversal learning on this task. To determine whether this is a general characteristic of mammals, in the present research, pigeons (Columba livia) and dogs (Canis familiaris) were tested with a simultaneous spatial discrimination mid-session reversal. Overall, dogs performed the task more poorly than pigeons. Interestingly, both pigeons and dogs employed what resembled a timing strategy. However, dogs showed greater perseverative errors, suggesting that they may have relatively poorer working memory and inhibitory control with this task. The greater efficiency shown by pigeons with this task suggests they are better able to time and use the feedback from their preceding choice as the basis of their future choice, highlighting what may be a qualitative difference between the species.

  10. Manipulation of primary sex ratio in birds: lessons from the homing pigeon (Columba livia domestica).

    Science.gov (United States)

    Goerlich-Jansson, Vivian C; Müller, Martina S; Groothuis, Ton G G

    2013-12-01

    Across various animal taxa not only the secondary sex ratio but also the primary sex ratio (at conception) shows significant deviations from the expected equal proportions of sons and daughters. Birds are especially intriguing to study this phenomenon as avian females are the heterogametic sex (ZW); therefore sex determination might be under direct control of the mother. Avian sex ratios vary in relation to environmental or maternal condition, which can also affect the production of maternal steroids that in turn are involved in reproduction and accumulate in the developing follicle before meiosis. As the proximate mechanisms underlying biased primary sex ratio are largely elusive, we explored how, and to what extent, maternal steroid hormones may be involved in affecting primary or secondary sex ratio in clutches of various species of pigeons. First we demonstrated a clear case of seasonal change in sex ratio in first eggs both in the Rock Pigeon (Columba livia) and in a related species, the Wood Pigeon (Columba palumbus), both producing clutches of two eggs. In the Homing Pigeon (Columba livia domestica), domesticated from the Rock Pigeon, testosterone treatment of breeding females induced a clear male bias, while corticosterone induced a female bias in first eggs and we argue that this is in line with sex allocation theory. We next analyzed treatment effects on follicle formation, yolk mass, and yolk hormones, the latter both pre- and post-ovulatory, in order to test a diversity of potential mechanisms related to both primary and secondary sex ratio manipulation. We conclude that maternal plasma hormone levels may affect several pre-ovulatory mechanisms affecting primary sex ratio, whereas egg hormones are probably involved in secondary sex ratio manipulation only.

  11. Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour

    OpenAIRE

    Bamidele, Oluwaseun P; Akanbi, Charles T

    2013-01-01

    The effect of gamma irradiation at various doses (5, 10, 15, 20 kGy) was observed on pigeon pea flour stored for 3 months on proximate composition, functional properties, and peroxide value. Sensory evaluation was also carried out on bean cake (moinmoin) made from nonirradiated and irradiated pigeon pea flour. The results showed that stored gamma-irradiated samples had significantly lower (P < 0.05) value of protein and little or no effect on moisture content. There were slight decreases in c...

  12. Gastrointestinal helminths of two populations of wild pigeons (Columba livia) in Brazil.

    Science.gov (United States)

    Vaz, Frederico Fontanelli; Silva, Lidiane Aparecida Firmino da; Ferreira, Vivian Lindmayer; Silva, Reinaldo José da; Raso, Tânia Freitas

    2017-01-01

    The present study analyzed gastrointestinal helminth communities in 265 wild pigeons (Columba livia) living in the municipalities of São Paulo and Tatuí, state of São Paulo, Brazil, over a one-year period. The birds were caught next to grain storage warehouses and were necropsied. A total of 790 parasites comprising one nematode species and one cestode genus were recovered from 110 pigeons, thus yielding an overall prevalence of 41.5%, mean intensity of infection of 7.2 ± 1.6 (range 1-144) and discrepancy index of 0.855. Only 15 pigeons (5.7%) presented mixed infection. The helminths isolated from the birds were Ascaridia columbae (Ascaridiidae) and Raillietina sp. (Davaineidae). The birds' weights differed according to sex but this did not influence the intensity of infection. The overall prevalence and intensity of infection did not differ between the sexes, but the prevalence was higher among the birds from Tatuí (47.8%). The gastrointestinal helminth community of C. livia was characterized in the two areas studied and parasite homogeneity was observed over the 12 months analyzed at both locations. These results make contributions to the current literature on health aspects of wild C. livia populations.

  13. Sentinel pigeon surveillance for West Nile virus by using lard-can traps at differing elevations and canopy cover classes.

    Science.gov (United States)

    Deegan, Carrie S; Burns, Joseph E; Huguenin, Michael; Steinhaus, Eliza Y; Panella, Nicholas A; Beckett, Susan; Komar, Nicholas

    2005-11-01

    Sentinel pigeons, Columba livia, were installed in lard-can traps at heights of 1.5 m and 7.6-9.1 m within differing canopy cover classes in New York City. Adult mosquitoes were collected weekly from July to October 2002, as were serum samples from each pigeon. Culex pipiens L. and Culex restuans Theobald comprised 97% of mosquitoes collected and were most numerous in canopy-level, forested traps. The West Nile virus (family Flaviviridae, genus Flavivirus, WNV) seroconversion rate was significantly greater for pigeons in canopy-level traps, although seroconversions occurred concurrently with human cases in the city and were of little prognostic value to public health agencies. Our results indicate that sentinel pigeons were most effective for monitoring enzootic transmission of WNV when placed in single-sentinel caging 7.6-9.1 m above ground level.

  14. Development of cookies made with cocoyam, fermented sorghum and germinated pigeon pea flour blends using response surface methodology.

    Science.gov (United States)

    Okpala, Laura C; Okoli, Eric C

    2014-10-01

    Cookies were produced from blends of cocoyam, fermented sorghum and germinated pigeon pea flours. The study was carried out to evaluate the effects of varying the proportions of these components on the sensory and protein quality of the cookies. The sensory attributes studied were colour, taste, texture, crispness and general acceptability while the protein quality indices were biological value (BV) and net protein utilization (NPU). Mixture response surface methodology was used to model the sensory and protein quality with single, binary and ternary combinations of germinated pigeon pea, fermented sorghum and cocoyam flours. Results showed that BV and NPU of most of the cookies were above minimum acceptable levels. With the exception of cookies containing high levels of pigeon pea flour, cookies had acceptable sensory scores. Increase in pigeon pea flour resulted in increase in the BV and NPU. Regression equations suggested that the ternary blends produced the highest increase in all the sensory attributes (with the exception of colour).

  15. The Relationship between MC1R Mutation and Plumage Color Variation in Pigeons

    Directory of Open Access Journals (Sweden)

    Jin-Shan Ran

    2016-01-01

    Full Text Available The polymorphisms of MC1R gene play a crucial role in coat color variation in mammals; however, the relationship is still unclear in pigeons. In this study, we sequenced 741 bp fragment of the MC1R for 39 individuals with five plumage color patterns (gray plumage, n=12; black plumage, n=9; white plumage, n=3; spotted plumage, n=12; red plumage, n=3. A total of three single nucleotide polymorphisms (SNPs were detected, including G199A, G225A, and A466G, which subsequently determined four haplotypes (H1–H4. Among them, H1 is the predominant haplotype. Association analysis revealed that H1 and H3 were significantly associated with the black plumage trait (P<0.05, while the H4 was significantly associated with gray plumage trait (P<0.05. Furthermore, only diplotype H1H1 was significantly associated with black and gray traits of pigeons. Collectively, our study suggested an association between genetic variation of MC1R and plumage color in pigeon.

  16. Alterations in the Helicoverpa armigera midgut digestive physiology after ingestion of pigeon pea inducible leucine aminopeptidase.

    Directory of Open Access Journals (Sweden)

    Purushottam R Lomate

    Full Text Available Jasmonate inducible plant leucine aminopeptidase (LAP is proposed to serve as direct defense in the insect midgut. However, exact functions of inducible plant LAPs in the insect midgut remain to be estimated. In the present investigation, we report the direct defensive role of pigeon pea inducible LAP in the midgut of Helicoverpa armigera (Lepidoptera: Noctuidae and responses of midgut soluble aminopeptidases and serine proteinases upon LAP ingestion. Larval growth and survival was significantly reduced on the diets supplemented with pigeon pea LAP. Aminopeptidase activities in larvae remain unaltered in presence or absence of inducible LAP in the diet. On the contrary, serine proteinase activities were significantly decreased in the larvae reared on pigeon pea LAP containing diet as compared to larvae fed on diet without LAP. Our data suggest that pigeon pea inducible LAP is responsible for the degradation of midgut serine proteinases upon ingestion. Reduction in the aminopeptidase activity with LpNA in the H. armigera larvae was compensated with an induction of aminopeptidase activity with ApNA. Our findings could be helpful to further dissect the roles of plant inducible LAPs in the direct plant defense against herbivory.

  17. US Advanced Freight and Passenger MAGLEV System

    Science.gov (United States)

    Morena, John J.; Danby, Gordon; Powell, James

    1996-01-01

    Japan and Germany will operate first generation Maglev passenger systems commercially shortly after 2000 A.D. The United States Maglev systems will require sophisticated freight and passenger carrying capability. The U.S. freight market is larger than passenger transport. A proposed advanced freight and passenger Maglev Project in Brevard County Florida is described. Present Maglev systems cost 30 million dollars or more per mile. Described is an advanced third generation Maglev system with technology improvements that will result in a cost of 10 million dollars per mile.

  18. Stable panoramic views facilitate snap-shot like memories for spatial reorientation in homing pigeons.

    Directory of Open Access Journals (Sweden)

    Tommaso Pecchia

    Full Text Available Following spatial disorientation, animals can reorient themselves by relying on geometric cues (metric and sense specified both by the macroscopic surface layout of an enclosed space and prominent visual landmarks in arrays. Whether spatial reorientation in arrays of landmarks is based on explicit representation of the geometric cues is a matter of debate. Here we trained homing pigeons (Columba livia to locate a food-reward in a rectangular array of four identical or differently coloured pipes provided with four openings, only one of which allowed the birds to have access to the reward. Pigeons were trained either with a stable or a variable position of the opening on pipes, so that they could view the array either from the same or a variable perspective. Explicit mapping of configural geometry would predict successful reorientation irrespective of access condition. In contrast, we found that a stable view of the array facilitated spatial learning in homing pigeons, likely through the formation of snapshot-like memories.

  19. ACTION OF CHEMICALLY DIFFERENT PROSTAGLANDIN BLOCKERS ON THE ADRENAL HORMONES IN PIGEONS DURING STRESS.

    Science.gov (United States)

    Sarkar, S; Ghosh, S; Sengupta, S; Dasadhikari, S; Ghosh, A

    1999-01-01

    The effect of prostaglandin (PG) inhibitors differing in their chemical nature, viz. Aspirin (acetylsalicylic acid), Mefenamic acid (fenamates), Diclofenac (phenylacetic acid derivative) and Piroxicam (oxicam derivative) on the adrenal hormones was studied in acutely stressed pigeons. None of these PG blockers exerted any significant effect on the catecholamine and corticosterone content of the control, i.e. unstressed pigeon adrenal gland excepting mefenamic acid which caused a release of epinephrine. Aspirin, diclofenac and piroxicam did not modulate the catecholamine or corticosterone secretion whereas mefenamic acid caused a released of both epinephrine and norepinephrine and increased the adrenal corticosterone content in the acutely stressed pigeons. These results were compared with those obtained from studies on the effects of other chemically different PG blockers, indomethacin (a methylated indole derivative) and ibuprofen (a propionic acid derivative). It is suggested that chemically and structurally different PG inhibitors show diverse action in the same species under similar stress conditions.

  20. Genetic characterization of 11 microsatellite loci in Egyptian pigeons (Columba livia domestica) and their cross-species amplification in other Columbidae populations.

    Science.gov (United States)

    Ramadan, Sherif; Dawod, Ahmed; El-Garhy, Osama; Nowier, Amira M; Eltanany, Marwa; Inoue-Murayama, Miho

    2018-04-01

    This study aimed to analyze the genetic diversity and relationships of 10 Egyptian pigeon populations belonging to Columba livia domestica speciesusing 11 microsatellite markers and to investigate the success of these markers amplification across another eight pigeon species. Genomic DNA was isolated from feather samples of179 pigeon samples from 10 Egyptian breeds: Asfer Weraq (n=14), Austoraly (n=20), Reehani (n=21), Messawed (n=17), Nemssawy (n=27), Otatti (n=12), Morasla (n=17), Tumbler (n=22), Halaby Asfer (n=10), and Karakandy (n=19) in addition to Japanese feral pigeons (n=30). Genotyping was done using 11 specific polymorphic microsatellite makers. Moreover, 37 samples not belonging to C. livia domestica but belonging to another eight pigeon species were genotyped. The polymerase chain reaction (PCR) products were electrophoresed on an ABI 3130xl DNA Sequencer. The basic measures of genetic diversity and phylogenetic trees were computed using bioinformatics software. Across the 10 studied Egyptian populations, the number of alleles per locus ranged from 3 to 19 and the average number of alleles observed was 9.091. The lowest value of expected heterozygosity (0.373) was obtained for the Reehani breed, and the highest value (0.706) was found for Morasla breed. The overall expected heterozygosity of Egyptian pigeons was 0.548. The F ST coefficient which indicates fixation coefficients of subpopulations within the total population for the 11 loci varied from 0.318 to 0.114 with a relatively high mean (0.226). In our study, the F IS showed a relatively high average(0.037). The pairwise Reynolds's genetic distance between the11 studied pigeon populations recorded lower values between Otatti and Austoraly (0.025) and between Morasla and Japanese feral pigeons (0.054). These results are supported by clustering pattern either by the neighbor-joining phylogenetic tree or by a Bayesian clustering of STRUCTURE with the admixture method. We confirm the applicability of

  1. Genetic characterization of 11 microsatellite loci in Egyptian pigeons (Columba livia domestica) and their cross-species amplification in other Columbidae populations

    Science.gov (United States)

    Ramadan, Sherif; Dawod, Ahmed; El-Garhy, Osama; Nowier, Amira M.; Eltanany, Marwa; Inoue-Murayama, Miho

    2018-01-01

    Aim This study aimed to analyze the genetic diversity and relationships of 10 Egyptian pigeon populations belonging to Columba livia domestica speciesusing 11 microsatellite markers and to investigate the success of these markers amplification across another eight pigeon species. Methods Genomic DNA was isolated from feather samples of179 pigeon samples from 10 Egyptian breeds: Asfer Weraq (n=14), Austoraly (n=20), Reehani (n=21), Messawed (n=17), Nemssawy (n=27), Otatti (n=12), Morasla (n=17), Tumbler (n=22), Halaby Asfer (n=10), and Karakandy (n=19) in addition to Japanese feral pigeons (n=30). Genotyping was done using 11 specific polymorphic microsatellite makers. Moreover, 37 samples not belonging to C. livia domestica but belonging to another eight pigeon species were genotyped. The polymerase chain reaction (PCR) products were electrophoresed on an ABI 3130xl DNA Sequencer. The basic measures of genetic diversity and phylogenetic trees were computed using bioinformatics software. Results Across the 10 studied Egyptian populations, the number of alleles per locus ranged from 3 to 19 and the average number of alleles observed was 9.091. The lowest value of expected heterozygosity (0.373) was obtained for the Reehani breed, and the highest value (0.706) was found for Morasla breed. The overall expected heterozygosity of Egyptian pigeons was 0.548. The FST coefficient which indicates fixation coefficients of subpopulations within the total population for the 11 loci varied from 0.318 to 0.114 with a relatively high mean (0.226). In our study, the FIS showed a relatively high average(0.037). The pairwise Reynolds’s genetic distance between the11 studied pigeon populations recorded lower values between Otatti and Austoraly (0.025) and between Morasla and Japanese feral pigeons (0.054). These results are supported by clustering pattern either by the neighbor-joining phylogenetic tree or by a Bayesian clustering of STRUCTURE with the admixture method. Conclusions

  2. Getting passengers out : evacuation behaviours

    NARCIS (Netherlands)

    Boer, L.C.

    2003-01-01

    When disaster strikes, mass transportation means mass evacuation. The issue is especially urgent if, despite precautions, a train comes to a stop in a tunnel and there is a fire. Adequate behaviour of passengers is a major success factor of an evacuation. Passengers should replace their original

  3. Effect of Pigeon pea and Cow pea on the performance and gut immunity of broiler chicks

    International Nuclear Information System (INIS)

    Yagoub, Yagoub Magboul

    1998-03-01

    two experiments were conducted to examine the effect of pigeon pea and cow pea on the performance and gut immunity of broiler chicks. In experiment 1, 3 experimental diets were formulated containing graded levels of cow pea were maintained. Diets were prepared containing 18.21, 18.25 and 18.25% crude protein and 3076.41, 3062 Kel/Kg metabolizable energy for experiment 1, while diets of experiment 11 were prepared containing 18.21, 18.22, and 18.22% crude protein and 3076.41, 3080.5 and 3055.89 KEl/Kg metabolized energy. 120 Loghmann broiler chicks were equally allocated into 15 pens (8 chicks/pen). Then the experimental diets were randomly assigned to the pens. feed and water were provided ad libitum in both experiments. In experiment 1, the results showed no significant difference were found in chick performance at day 45. The feed conversation ratio increased with the level of pigeon pea used. The pancreas mass was increased as the level of pigeon pea increase. In experiment 2 the results showed significant decrease in the body weight and feed intake at day 45, while the pancreas mass tend to increase with increasing level of cow pea in the diet. Histological examination of small intestine slides showed no histopathological differences between the control and chicks fed cow pea and/or pigeon pea. Immunological test of the serum and mucous samples using ELISA techniques revealed no significant difference between the control and chicks given cow pea and / or pigeon pea

  4. Genetic parameters of body weight and prolificacy in pigeons

    Directory of Open Access Journals (Sweden)

    Beaumont Catherine

    2000-07-01

    Full Text Available Abstract Genetic parameters of body weight at weaning and of prolificacy were estimated in three commercial lines of pigeons selected by BLUP (Best Linear Unbiased Prediction on both traits. The model of analysis took into account the direct genetic effects for both traits and the effect of parental permanent environment for body weight. Depending on the line considered, body weight varied from 556.7 g to 647.6 g and prolificacy ranged from 12.5 to 16.8 pigeons weaned per couple of parents per year. Heritability of body weight was high, varying between 0.46 and 0.60, and permanent environment was responsible for 6% to 9% of the total variability. On the contrary, prolificacy was poorly heritable (0.04 to 0.12. They were highly and negatively correlated (-0.77 to -0.82. Body weight showed significant genetic trends in lines B and C. No significant genetic difference could be observed between males and females for both traits.

  5. Chlamydia psittaci and C. avium in feral pigeon (Columba livia domestica) droppings in two cities in the Netherlands

    NARCIS (Netherlands)

    Burt, Sara A.; Röring, Romy E.; Heijne, Marloes

    2018-01-01

    Background: Feral pigeons (Columba livia domestica) live and breed in many city centres and contact with their droppings can be a hazard for human health if the birds carry Chlamydia psittaci. Objective: The aim of this study was to establish whether pigeon droppings in two Dutch cities (Utrecht and

  6. Preparation and evaluation of doxycycline hydrochloride and bromhexine hydrochloride dosage forms for pigeons / Marga le Roux

    OpenAIRE

    Le Roux, Marga

    2004-01-01

    Objective: To prepare and evaluate three different dosage forms, containing doxycycline hydrochloride (HCI) and bromhexine hydrochloride (HCI) respectively and in combination, for the treatment of respiratory diseases in pigeons. Background: Birds have held a place in man's affection since the ancient Egyptians and Romans kept birds. Europeans have successfully bred birds, especially smaller birds and pigeons, for centuries. Only in recent years, however, have science and me...

  7. Pigeons (Columba livia) as Trainable Observers of Pathology and Radiology Breast Cancer Images.

    Science.gov (United States)

    Levenson, Richard M; Krupinski, Elizabeth A; Navarro, Victor M; Wasserman, Edward A

    2015-01-01

    Pathologists and radiologists spend years acquiring and refining their medically essential visual skills, so it is of considerable interest to understand how this process actually unfolds and what image features and properties are critical for accurate diagnostic performance. Key insights into human behavioral tasks can often be obtained by using appropriate animal models. We report here that pigeons (Columba livia)-which share many visual system properties with humans-can serve as promising surrogate observers of medical images, a capability not previously documented. The birds proved to have a remarkable ability to distinguish benign from malignant human breast histopathology after training with differential food reinforcement; even more importantly, the pigeons were able to generalize what they had learned when confronted with novel image sets. The birds' histological accuracy, like that of humans, was modestly affected by the presence or absence of color as well as by degrees of image compression, but these impacts could be ameliorated with further training. Turning to radiology, the birds proved to be similarly capable of detecting cancer-relevant microcalcifications on mammogram images. However, when given a different (and for humans quite difficult) task-namely, classification of suspicious mammographic densities (masses)-the pigeons proved to be capable only of image memorization and were unable to successfully generalize when shown novel examples. The birds' successes and difficulties suggest that pigeons are well-suited to help us better understand human medical image perception, and may also prove useful in performance assessment and development of medical imaging hardware, image processing, and image analysis tools.

  8. Behavioral studies with anxiolytic drugs. IV. Serotonergic involvement in the effects of buspirone on punished behavior of pigeons

    International Nuclear Information System (INIS)

    Witkin, J.M.; Mansbach, R.S.; Barrett, J.E.; Bolger, G.T.; Skolnick, P.; Weissman, B.

    1987-01-01

    Interactions of the nonbenzodiazepine anxiolytic, buspirone, with serotonin (5-HT) were studied using behavioral and neurochemical procedures. Punished responding was studied in pigeons as this behavior is a generally acknowledged preclinical predictor of anxiolytic activity and because buspirone increases punished responding of pigeons with greater potency and efficacy than in other species. Keypeck responses were maintained under either fixed-interval or fixed-ratio schedules of food presentation; every 30th response produced a brief electric shock and suppressed responding (punishment). Buspirone (0.1-5.6 mg/kg i.m.) produced dose-related increases in punished responding which reached a maximum at 1 mg/kg. A serotonin agonist, MK-212 (0.01 mg/kg), antagonized whereas the 5-HT antagonist, cyproheptadine (0.01 mg/kg), potentiated the effects of buspirone without having behavioral effects of their own. The characteristics of [ 3 H]-5-HT binding in pigeon brain membranes were similar to results reported in mammalian brain. Neither buspirone, MJ-13805 (gepirone, a related analog), nor MJ-13653 (a buspirone metabolite), significantly affected [ 3 H]-5-HT binding and none of the compounds appreciably inhibited uptake of [ 3 H]-5-HT into pigeon cerebral synaptosomes. Hill coefficients significantly less than unity for all drugs except 5-HT suggested multiple serotonergic binding sites for buspirone and analogs. Buspirone and MJ-13805 (1 nM) inhibited [ 3 H]ketanserin binding (a measure of 5-HT2 binding sites) in pigeon cerebrum with Ki values above 10(-6) M. The number of [ 3 H]ketanserin binding sites was estimated to be 109 fmol/mg of protein in pigeon cerebrum compared to 400 fmol/mg of protein in rat cerebrum

  9. Optimal boarding method for airline passengers

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab

    2008-02-01

    Using a Markov Chain Monte Carlo optimization algorithm and a computer simulation, I find the passenger ordering which minimizes the time required to board the passengers onto an airplane. The model that I employ assumes that the time that a passenger requires to load his or her luggage is the dominant contribution to the time needed to completely fill the aircraft. The optimal boarding strategy may reduce the time required to board and airplane by over a factor of four and possibly more depending upon the dimensions of the aircraft. I explore some features of the optimal boarding method and discuss practical modifications to the optimal. Finally, I mention some of the benefits that could come from implementing an improved passenger boarding scheme.

  10. Telemedical advice to long-distance passenger ferries

    DEFF Research Database (Denmark)

    Jensen, Olaf C; Bo Bøggild, Niels; Kristensen, Søren

    2005-01-01

    BACKGROUND: Radio medical (RM) advice for seafarers and traveling passengers is important and can be crucial for the optimal medical treatment on board ships. The aim of this study was to analyze the data from consultations with passenger ferries to identify areas for possible improvements. METHODS......: Data from the journals for 1 year from Radio Medical Denmark consultations with the medical officers on passenger ferries were analyzed retrospectively. RESULTS: Two hundred fourteen RM records, 73% pertaining to passengers and 27% for crew members, were analyzed. Passenger patients were generally...... complaints, and more than half of these involved severe or considerable pain. Only acetaminophen (paracetamol) and opioids were in the ferry medicine chest. At least 77 patients would have benefited from use of nonsteroidal anti-inflammatory drugs. CONCLUSIONS: The paramedical assistance and the medicine...

  11. Evaluation of Clausena pentaphylla (Roxb.) DC oil as a fungitoxicant against storage mycoflora of pigeon pea seeds.

    Science.gov (United States)

    Pandey, Abhay K; Palni, Uma T; Tripathi, Nijendra N

    2013-05-01

    The present study aimed to evaluate the antifungal activity of 30 essential oils against four dominant fungi Aspergillus flavus Link., A. niger van Tieghem, A. ochraceus Wilhelm and A. terreus Thom of stored pigeon pea seeds at a concentration of 0.36 µL mL(-1). Various fungitoxic properties, such as minimum inhibitory concentration, minimum fungicidal concentration and fungitoxic spectrum, of the most potent oil were determined. The efficacy of the most potent oil in preservation of pigeon pea seeds for 6 months was also carried out by storing 1 kg of seeds in the oil vapour. Clausena pentaphylla and Citrus limon oils were more effective against all the fungi tested, which exhibited 100% per cent mycelial inhibition. The minimum inhibitory concentration of C. pentaphylla oil was determined as 0.07 µL mL(-1) against all the test fungi and was found to be more toxic than Citrus limon oil. C. pentaphylla oil exhibited a broad range of fungitoxicity against 16 other storage fungi of pigeon pea seeds. C. pentaphylla oil significantly protected 1 kg seeds of pigeon pea from fungal deterioration and was superior to synthetic fumigants. The oil did not show any phytotoxicity and the protein content of the seeds was significantly retained for up to 6 months of storage. Thus, C. pentaphylla oil may be used as an effective fumigant in the ecofriendly management of storage fungi of pigeon pea seeds. © 2012 Society of Chemical Industry.

  12. Level of service at airport passenger terminals

    Directory of Open Access Journals (Sweden)

    Tasić Tamara D.

    2016-01-01

    Full Text Available Airport terminals are designed by level of service standards which are regulated by International Air Transport Association (IATA. Level of service offered to passengers, regarding to the primary processes, is not necessarily equivalent to the level of service perceived by them. The fact that passengers spending longer times in terminals makes the secondary processes more important in passenger experience. Aiming to improving airport attractiveness, and business success, passenger perception is approached by paying close attention. This paper discusses the two aspects of level of service. Concept of level of service used in air traffic industry with purpose of designing and planning of passenger terminal is derived from the Highway Capacity Manual. Subject of the paper regards last changes which have been introduced during 2014. Second part of the paper explains the needs of examining and analyzing passenger perception from the management point of view, and gives overview of methods which are conducted during researches. Similarities and differences are shown among measurements of level of service and perceived level of service, including the importance of these aspects mutual complementing.

  13. Differential expression of fatty acid transporters and fatty acid synthesis-related genes in crop tissues of male and female pigeons (Columba livia domestica) during incubation and chick rearing.

    Science.gov (United States)

    Xie, Peng; Wang, Xue-Ping; Bu, Zhu; Zou, Xiao-Ting

    2017-10-01

    1. The growth performance of squabs reared solely by male or female parent pigeons was measured, and the changes of lipid content of crop milk and the expression profiles of genes potentially involved in lipid accumulation by crop tissues of parent pigeons were evaluated during incubation and chick rearing. 2. Squabs increased in body weight during 25 d of rearing, whereas both male and female pigeons lost weight after finishing rearing chicks, and the weight loss of male pigeons was significantly greater than that of female parent pigeons. Lipid content of crop milk from both parent pigeons gradually decreased to the crude fat level in the formulated diet after 10 d (R10) of chick rearing. 3. The gene expression of fatty acid translocase (FAT/CD36), fatty acid-binding protein 5 (EFABP) and acyl-CoA-binding protein (ACBP) in male pigeon crop tissue were the greatest at 17 d (I17) of incubation. In female pigeons, FAT/CD36 expression was the highest at I14, and both EFABP and ACBP expression peaked at I14 and R7. The expression of acetyl-CoA carboxylase and fatty acid synthase in male pigeons reached the maximum level at R1, while they peaked at I14 and I17, respectively in female pigeons. The gene expression of peroxisome proliferators-activated receptor-gamma (PPARγ) was the greatest at I17 in the male, while it was at I14 in the female. However, no regular changing pattern was found in PPARα gene expression in male pigeons. 4. These results indicated that male and female pigeons may make different contributions in rearing squabs. The gene expression study suggested that fatty acids used in lipid biosynthesis of crop milk probably originated from both exogenous supply and de novo synthesis. The sex of the parent pigeon affected the lipid content of crop milk and the expression profiles of genes involved in fatty acid transportation and lipogenesis.

  14. The effect of food quality during growth on spatial memory consolidation in adult pigeons.

    Science.gov (United States)

    Scriba, M F; Gasparini, J; Jacquin, L; Mettke-Hofmann, C; Rattenborg, N C; Roulin, A

    2017-02-15

    Poor environmental conditions experienced during early development can have negative long-term consequences on fitness. Animals can compensate for negative developmental effects through phenotypic plasticity by diverting resources from non-vital to vital traits such as spatial memory to enhance foraging efficiency. We tested in young feral pigeons ( Columba livia ) how diets of different nutritional value during development affect the capacity to retrieve food hidden in a spatially complex environment, a process we refer to as 'spatial memory'. Parents were fed with either high- or low-quality food from egg laying until young fledged, after which all young pigeons received the same high-quality diet until memory performance was tested at 6 months of age. The pigeons were trained to learn a food location out of 18 possible locations in one session, and then their memory of this location was tested 24 h later. Birds reared with the low-quality diet made fewer errors in the memory test. These results demonstrate that food quality during development has long-lasting effects on memory, with a moderate nutritional deficit improving spatial memory performance in a foraging context. It might be that under poor feeding conditions resources are redirected from non-vital to vital traits, or pigeons raised with low-quality food might be better in using environmental cues such as the position of the sun to find where food was hidden. © 2017. Published by The Company of Biologists Ltd.

  15. Molecular cloning, characterization, and expression analysis of ghrelin and cholecystokinin in the pigeon (Columba livia).

    Science.gov (United States)

    Xie, P; Wan, X P; Bu, Z; Zou, X T

    2016-11-01

    Ghrelin and cholecystokinin (CCK) are multifunctional peptides. In the current study, complete sequences of ghrelin (800 bp) and CCK (739 bp) were firstly cloned in Columba livia by using rapid amplification of cDNA ends (RACE) method. The open reading frames of ghrelin (351bp) and CCK (393bp) encoded 116 amino acids and 130 amino acids, respectively. Sequence comparison indicated that pigeon ghrelin and CCK shared high identity with those reported in other avian species. Quantitative real-time PCR analysis found that ghrelin and CCK mRNAs expressed in three intestinal segments of pigeon during development. Both ghrelin and CCK showed generally higher expressions at days posthatch than embryonic periods regardless of intestinal segments. In duodenum and ileum, the expressions of ghrelin and CCK mRNA reached the peak values at 8 d posthatch. Jejunum CCK mRNA level increased linearly after hatching, and reached the highest point at posthatch 28 d. Based on documented effects of long chain fatty acids (LCFAs) on pigeon ghrelin and CCK expression were also investigated in vitro. Higher concentrations (50 μM or 250 μM) of linoleic acid, α-linolenic acid or arachidonic acid can significantly increase ghrelin mRNA level in pigeon jejunum. However, for oleic acid, the induction of ghrelin gene expressions needed a lower concentration (5 μM). 5 μM of linoleic acid, α-linolenic acid or arachidonic acid and 250 μM palmitic acid repressed CCK expression significantly. A higher concentration (250 μM) of oleic acid or α-linolenic acid can up-regulate CCK mRNA level significantly. Our results indicated that ghrelin and CCK may act key functions in pigeon intestine development and their expressions could be regulated by LCFAs. © 2016 Poultry Science Association Inc.

  16. Pigeons and their droppings as reservoirs of Candida and other zoonotic yeasts.

    Science.gov (United States)

    Rosario Medina, Inmaculada; Román Fuentes, Lorena; Batista Arteaga, Miguel; Real Valcárcel, Fernando; Acosta Arbelo, Félix; Padilla Del Castillo, Daniel; Déniz Suárez, Soraya; Ferrer Quintana, Otilia; Vega Gutiérrez, Belinda; Silva Sergent, Freddy; Acosta-Hernández, Begoña

    The importance of pigeons as reservoirs and carriers of Cryptococcus neoformans and other species of this genus is well-known; however, less is known about their role as reservoirs and carriers of other yeasts that impact public health. The present study was performed on Gran Canaria Island to define yeasts other than Cryptococcus spp. that have been reported to impact public health and which could be carried by pigeons. Samples were obtained from 83 pigeon lofts (Columba livia); moreover, 331 crop samples, 331 cloacal samples and 174 dropping samples were collected. In addition, 17 dropping samples were taken from a total of 17 public squares. Samples were inoculated on Sabouraud dextrose agar with chloramphenicol. Different yeast species, i.e. Candida guilliermondii (24.36%), Candida kefyr (1.21%), Saccharomyces cerevisiae (2.43%), and Trichosporon asahii (1.21%) were isolated for the first time from the cloaca. The most frequently isolated yeast from the crop, cloaca and dropping samples from lofts was C. guilliermondii (30.46%, 24.36% and 49.37%, respectively). In addition, for the first time, C. kefyr (3.65%), Candida pelliculosa (2.43%), Candida rugosa (1.21%), T. asahii (3.65%), Trichosporon mucoides (3.65%) and Prototheca wickerhamii (1.21%) were obtained from crop samples; Candida pelliculosa (1.20%), T. asahii (9.63%) and T. mucoides (7.22%) were isolated from dropping samples in the lofts. Candida albicans was the most frequently isolated yeast in dropping samples collected in public squares. It can be assumed that pigeons and their droppings act as carriers and reservoirs of Candida spp. and other zoonotic yeasts. Copyright © 2017 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. 49 CFR 223.15 - Requirements for existing passenger cars.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Requirements for existing passenger cars. 223.15... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SAFETY GLAZING STANDARDS-LOCOMOTIVES, PASSENGER CARS AND CABOOSES Specific Requirements § 223.15 Requirements for existing passenger cars. (a) Passenger cars built or...

  18. The Effect of Passengers on Teen Driver Behavior

    Science.gov (United States)

    2012-04-01

    A number of studies have shown that passengers substantially increase the risk of crashes for young, novice drivers. This increased risk may result from distractions that young passengers create for drivers. Alternatively, the presence of passengers ...

  19. Pigeons learn stimulus identity and stimulus relations when both serve as redundant, relevant cues during same-different discrimination training.

    Science.gov (United States)

    Gibson, Brett M; Wasserman, Edward A

    2003-01-01

    The authors taught pigeons to discriminate displays of 16 identical items from displays of 16 nonidentical items. Unlike most same-different discrimination studies--where only stimulus relations could serve a discriminative function--both the identity of the items and the relations among the items were discriminative features of the displays. The pigeons learned about both stimulus identity and stimulus relations when these 2 sources of information served as redundant, relevant cues. In tests of associative competition, identity cues exerted greater stimulus control than relational cues. These results suggest that the pigeon can respond to both specific stimuli and general relations in the environment.

  20. Antioxidation, angiotensin converting enzyme inhibition activity, nattokinase, and antihypertension of Bacillus subtilis (natto)-fermented pigeon pea

    OpenAIRE

    Bao-Hong Lee; Yi-Syuan Lai; She-Ching Wu

    2015-01-01

    Because of the high incidence of cardiovascular diseases in Asian countries, traditional fermented foods from Asia have been increasingly investigated for antiatherosclerotic effects. This study investigated the production of nattokinase, a serine fibrinolytic enzyme, in pigeon pea by Bacillus subtilis fermentation. B. subtilis 14714, B. subtilis 14715, B. subtilis 14716, and B. subtilis 14718 were employed to produce nattokinase. The highest nattokinase activity in pigeon pea was obtained us...

  1. Perfect state of Cryptococcus neoformans, Filobasidiella neoformans, on pigeon manure filtrate agar

    Energy Technology Data Exchange (ETDEWEB)

    Staib, F.

    1981-02-01

    To enable studies of the dependence of Cryptococcus neoformans and its perfect and imperfect states upon bird manure as a habitat of this pathogen, a nutrient medium closely resembling natural conditions was prepared. As sole nutrient, the water soluble ingredients of manure from pigeons (Columbia livia) were used. There was no heat sterilization of the manure filtrate. Using a standard pair of C. neoformans strains for mating, it could be demonstrated that the perfect state of the fungus developed on this so called pigeon manure filtrate agar within 48 h at 26 degrees C. This medium is supposed to help in the elucidation of the epidemiological significance of the perfect and imperfect states of this pathogen.

  2. COMPARATIVE EFFICACY (SEDATIVE AND ANAESTHETIC OF DETOMIDINE, KETAMINE AND DETOMIDINE-KETAMINE COCKTAIL IN PIGEONS (COLUMBA LIVIA

    Directory of Open Access Journals (Sweden)

    UZMA F. DURRANI, M. ARIF KHAN1 AND S. SALEEM AHMAD

    2008-07-01

    Full Text Available A study was conducted to compare the synergistic efficacy of detomidine, ketamine and their cocktail in pigeons (Columba livia. For this study, 15 adult and healthy pigeons were divided into three equal groups A, B and C. Birds of groups A and B were intramuscularly administered detomidine and ketamine @ 1.4 and 60 mg/kg b. wt., respectively. Pigeons of group C received detomidine + Ketamine cocktail @ 0.7 and 30 mg/kg b. wt. Induction of sedation and anaesthesia was smooth in all groups. Mean duration of induction was 11.1 + 2.03, 11.0 + 1.49 and 1.6 + 0.48 minutes in groups A, B, C, respectively. In groups A and B, smooth but light sedation and anaesthesia were observed accompanied by superficial analgesia, while in group C, birds showed deep anaesthesia alongwith deep analgesia. Birds in groups A and C elicited hypothermia, respiratory depression and bradycardia till complete recovery, while group B showed hyperthermia and tachycardia with rapid respiration. In group A, sedation persisted for 54.2 + 21.82 minutes and mean recovery period was 49.9 + 5.91 minutes, while groups B and C had anaesthesia for 47.7 + 8.06 and 103.5 + 27.52 minutes, and recovery periods were 52.6 + 9.64 and 61.3 + 17.26 minutes, respectively. Recovery was rough in group B and smooth in groups A and C. It was concluded that in pigeons, detomidine (alone is safe for handling and for least painful procedures, while detomidine-ketamine cocktail is safe as intramuscular anaesthetic for major surgical procedures. However, ketamine is not a good anaesthetic to be used alone in pigeons.

  3. Gastrointestinal helminths of two populations of wild pigeons (Columba livia in Brazil

    Directory of Open Access Journals (Sweden)

    Frederico Fontanelli Vaz

    Full Text Available Abstract The present study analyzed gastrointestinal helminth communities in 265 wild pigeons (Columba livia living in the municipalities of São Paulo and Tatuí, state of São Paulo, Brazil, over a one-year period. The birds were caught next to grain storage warehouses and were necropsied. A total of 790 parasites comprising one nematode species and one cestode genus were recovered from 110 pigeons, thus yielding an overall prevalence of 41.5%, mean intensity of infection of 7.2 ± 1.6 (range 1-144 and discrepancy index of 0.855. Only 15 pigeons (5.7% presented mixed infection. The helminths isolated from the birds were Ascaridia columbae (Ascaridiidae and Raillietina sp. (Davaineidae. The birds’ weights differed according to sex but this did not influence the intensity of infection. The overall prevalence and intensity of infection did not differ between the sexes, but the prevalence was higher among the birds from Tatuí (47.8%. The gastrointestinal helminth community of C. livia was characterized in the two areas studied and parasite homogeneity was observed over the 12 months analyzed at both locations. These results make contributions to the current literature on health aspects of wild C. livia populations.

  4. Experimental infection with Brazilian Newcastle disease virus strain in pigeons and chickens

    Directory of Open Access Journals (Sweden)

    Adriano de Oliveira Torres Carrasco

    2016-03-01

    Full Text Available Abstract This study was designed with the goal of adding as much information as possible about the role of pigeons (Columba livia and chickens (Gallus gallus in Newcastle disease virus epidemiology. These species were submitted to direct experimental infection with Newcastle disease virus to evaluate interspecies transmission and virus-host relationships. The results obtained in four experimental models were analyzed by hemagglutination inhibition and reverse transcriptase polymerase chain reaction for detection of virus shedding. These techniques revealed that both avian species, when previously immunized with a low pathogenic Newcastle disease virus strain (LaSota, developed high antibody titers that significantly reduced virus shedding after infection with a highly pathogenic Newcastle disease virus strain (São Joao do Meriti and that, in chickens, prevent clinical signs. Infected pigeons shed the pathogenic strain, which was not detected in sentinel chickens or control birds. When the presence of Newcastle disease virus was analyzed in tissue samples by RT-PCR, in both species, the virus was most frequently found in the spleen. The vaccination regimen can prevent clinical disease in chickens and reduce viral shedding by chickens or pigeons. Biosecurity measures associated with vaccination programs are crucial to maintain a virulent Newcastle disease virus-free status in industrial poultry in Brazil.

  5. Echoic memory in pigeons.

    Science.gov (United States)

    Kretzschmar, Christina; Kalenscher, Tobias; Güntürkün, Onur; Kaernbach, Christian

    2008-10-01

    It is unknown whether birds are able to retain the memory of purely sensory auditory information such as white noise over an extended period of time. In a Pavlovian heart rate conditioning paradigm, four pigeons were trained to associate a mild electric shock with periodic random waveforms, and no shock with aperiodic noise. Periodic waveform detection requires echoic memory, i.e., the online retention of a waveform pattern over a limited time. Starting with 40ms, the waveform period was increased after successful learning until no significant stimulus discrimination could be found. Significant discrimination was achieved at periods of up to 2560ms. This is the first demonstration that echoic memory performance in birds is clearly superior to cats and gerbils, and comparable to naive human performance.

  6. Effect of incorporation of decorticated pigeon pea (Cajanus cajan) protein isolate on functional, baking and sensory characteristics of Wheat (Triticum aesitivum) biscuit

    OpenAIRE

    H. A. Hassan; A.I. Mustafa; A.R. Ahmed

    2013-01-01

    This study was undertaken with the objectives of using the decorticated pigeon pea protein isolate in the development of protein rich-biscuit, suitable for general and specific nutritional purposes and to study the effect of incorporation of pigeon pea protein isolate on the sensory evaluation and quality of biscuit produced. Decorticated Pigeon Pea protein Isolate (DPPI) was incorporated in wheat (Triticum aesitivum) flour (WF, extraction rate 72%), for making fortified biscuit. Ratios of DP...

  7. Memory systems interaction in the pigeon: working and reference memory.

    Science.gov (United States)

    Roberts, William A; Strang, Caroline; Macpherson, Krista

    2015-04-01

    Pigeons' performance on a working memory task, symbolic delayed matching-to-sample, was used to examine the interaction between working memory and reference memory. Reference memory was established by training pigeons to discriminate between the comparison cues used in delayed matching as S+ and S- stimuli. Delayed matching retention tests then measured accuracy when working and reference memory were congruent and incongruent. In 4 experiments, it was shown that the interaction between working and reference memory is reciprocal: Strengthening either type of memory leads to a decrease in the influence of the other type of memory. A process dissociation procedure analysis of the data from Experiment 4 showed independence of working and reference memory, and a model of working memory and reference memory interaction was shown to predict the findings reported in the 4 experiments. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  8. Detection and characterization of Escherichia coli O157:H7 from feral pigeon in Qom province, Iran

    Directory of Open Access Journals (Sweden)

    Hossein Esameili

    2015-02-01

    Full Text Available Objective: To detect and characterize Escherichia coli (E. coli O157:H7 in feral pigeons in Qom province, Iran. Methods: In this survey, 290 cloacal samples were obtained from trapped feral pigeons in Qom province. Microbiological, biochemical and serological examinations were done to detect the E. coli O157:H7. Isolates were subjected to multiplex polymerase chain reaction for the detection of stx1, stx2, eaeA and hlyA genes. Results: Four samples (1.38% were positive for E. coli O157:H7 by using O157 and H7 antisera and only one E. coli O157:H7 strain isolated showed the presence of stx1, stx2, eaeA and hlyA genes. Conclusions: The results of present survey revealed that feral pigeons in Qom province had the potential to be a reservoir of E. coli O157:H7. The low prevalence of E. coli O157:H7 can be attributed to sampling each pigeon just once and fecal culture limits, and true prevalence of the E. coli O157:H7 might be higher than our findings.

  9. Characterization of pigeon paramyxoviruses (Newcastle disease virus) isolated in South Africa from 2001 to 2006.

    Science.gov (United States)

    Abolnik, C; Gerdes, G H; Kitching, J; Swanepoel, S; Romito, M; Bisschop, S P R

    2008-06-01

    Pigeon paramyxovirus type 1 (PPMV-1), a variant of Newcastle disease virus that primarily affects doves and pigeons has been isolated in South Africa since the mid-1980s. Phylogenetic evidence indicates that pigeon paramyxovirus type 1 viruses were introduced into South Africa on multiple occasions, based on the presence of two separate lineages, 4bi and 4bii, that have been circulating in Europe and the Far East since the early 1990s. During 2006, a PPMV-1 virus was isolated from an African ground hornbill (Bucorvus leadbeateri) which became acutely infected with PPMV-1 and died, probably after scavenging off infected dove carcasses in the region, since a closely-related PPMV-1 strain was also isolated from doves collected nearby. The hornbill isolate had ICPI and MDT values characteristic of PPMV-1 strains. The threat of PPMV-1 to poultry production and biodiversity in southern Africa highlights the importance of monitoring the spread of this strain.

  10. Characterization of pigeon paramyxoviruses (Newcastle disease virus isolated in South Africa from 2001 to 2006

    Directory of Open Access Journals (Sweden)

    C. Abolnik

    2008-08-01

    Full Text Available Pigeon paramyxovirus type 1 (PPMV-1, a variant of Newcastle disease virus that primarily affects doves and pigeons has been isolated in South Africa since the mid-1980s. Phylogenetic evidence indicates that pigeon paramyxovirus type 1 viruses were introduced in to South Africa on multiple occasions, based on the presence of two separate lineages, 4bi and 4bii, that have been circulating in Europe and the Far East since the early 1990s. During 2006, a PPMV-1 virus was isolated from an African ground hornbil(l Bucorvus leadbeateri which becamea cutely infected with PPMV-1 and died, probably after scavenging off infected dove carcasses in the region, since a closely-related PPMV-1 strain was also isolated from doves collected nearby. The hornbill isolate had lCPl and MDT values characteristic of PPMV-1s trains. The threat of PPMV-1 to poultry production and biodiversity in southern Africa highlights the importance of monitoring the spread of this strain.

  11. Bimodal extinction without cross-modal extinction.

    OpenAIRE

    Inhoff, A W; Rafal, R D; Posner, M J

    1992-01-01

    Three patients with unilateral neurological injury were clinically examined. All showed consistent unilateral extinction in the tactile and visual modalities on simultaneous intramodal stimulation. There was virtually no evidence for cross-modal extinction, however, so that contralateral stimulation of one modality would have extinguished perception of ipsilateral stimuli in the other modality. It is concluded that the attentional system controlling the encoding of tactile and visual stimuli ...

  12. More than classical Chlamydia psittaci in urban pigeons.

    Science.gov (United States)

    Sachse, Konrad; Kuehlewind, Simone; Ruettger, Anke; Schubert, Evelyn; Rohde, Gernot

    2012-06-15

    In the literature, studies of Chlamydia infection in birds have usually been confined to the search for Chlamydia (C., formerly Chlamydophila) psittaci, so that little is known about the presence of other chlamydial agents. In the present study, cloacal swabs and faeces samples of urban pigeons have been examined by real-time PCR, DNA microarray assays and partial ompA sequencing. Whilst C. psittaci was the predominant chlamydial agent in this pigeon population (75.8% of all Chlamydiaceae positives), the combined use of highly specific and sensitive molecular assays facilitated the detection of atypical serovars of C. psittaci, as well as other species of Chlamydia, such as C. abortus. Detection of C. pecorum and C. trachomatis from an avian host is reported here for the first time. Rather unexpectedly, 19.5% of all Chlamydiaceae-positive cases turned out to be infected with non-classified organisms. The considerable prevalence of these novel agents raises the question of their epidemiological importance and possible role as pathogens. Future surveys in domestic and wild birds will have to take the extended variety of chlamydial organisms into account. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Effects of hormonal priming on seed germination of pigeon pea under cadmium stress

    Directory of Open Access Journals (Sweden)

    LARISSA C. SNEIDERIS

    2015-09-01

    Full Text Available In this work we investigated whether priming with auxin, cytokinin, gibberellin, abscisic acid and ethylene, alters the physiological responses of seeds of pigeon pea germinated under water and cadmium stress. Seeds treated with water or non-treated seeds were used as control. Although compared to non-treated seeds we found that the hormone treatments improve the germination of pigeon pea under cadmium stress, however, these treatments did not differ from water. However, we also observed a trend of tolerance to the effects of cadmium in the presence of ethylene, suggesting that the use of this hormone may be an efficient method to overcome seed germination under metal stress.

  14. ISSUES OF ORGANIZING THE PASSENGER TRANSPORTATION ON US RAILWAYS

    Directory of Open Access Journals (Sweden)

    R. H. Korobiova

    2017-04-01

    Full Text Available Purpose. The paper focuses on a study of the US railway transport organization management during passenger transportation. Methodology. Studies were carried out on the basis of the analysis of literature sources and reporting data on passenger transportation in the USA. Findings. Negative trends in the work of the passenger complex of the Ukrainian railways are the slowdown in the volumes of transportation, the progressive aging of the rolling stock and the overall activity running at a loss for Ukrzaliznytsia. In this regard, the actual task for domestic rail transport is the implementation of industry reforms. Therefore, the paper presented the study of the experience of organizing the passenger transportation on US railways, whose peculiarity is the extremely high degree of competition between modes of transport. As a result of the conducted analysis for working conditions of the US and Ukrainian railways, the general conditions for the functioning of the railways in both countries connected with passenger transportation securing have been established. It was found that general condition for execution of railway passenger transportation for the United States and Ukraine is the subsidization of this activity and combined use of infrastructure for the freight and passengers’ transportations. In this connection, when developing approaches to reforming the passenger economy of Ukraine's railways, it is advisable to use the experience of the United States in assessing the social effectiveness of rail transport, the impact of passenger transportation on the conditions of freight trains handling, and combined use of railway infrastructure by freight and passenger companies. Originality. The author determined the general trends in the development of passenger railway transportation in the US and Ukraine. Practical value. The resulted methods of organizing the operation of the US railway passenger transportation complex can be adapted to solve

  15. Rethinking Extinction

    OpenAIRE

    Dunsmoor, Joseph E.; Niv, Yael; Daw, Nathaniel; Phelps, Elizabeth A.

    2015-01-01

    Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavior...

  16. Study the effect of insecticide dimethoate on photosynthetic pigments and photosynthetic activity of pigeon pea: Laser-induced chlorophyll fluorescence spectroscopy.

    Science.gov (United States)

    Pandey, Jitendra Kumar; Dubey, Gunjan; Gopal, R

    2015-10-01

    Pigeon pea is one of the most important legume crops in India and dimethoate is a widely used insecticide in various crop plants. We studied the effect of dimethoate on growth and photosynthetic activity of pigeon pea plants over a short and long term exposure. Plant growth parameters, photosynthetic pigment content and chlorophyll fluorescence response of pigeon pea (Cajanus cajan L.) plants treated with various concentrations of the insecticide dimethoate (10, 20, 40 and 80 ppm) have been compared for 30 days at regular intervals of 10 days each. Laser induced chlorophyll fluorescence spectra and fluorescence-induction kinetics (FIK) curve of dimethoate treated pigeon pea plants were recorded after 10, 20 and 30 days of treatment. Fluorescence intensity ratio at the two fluorescence maxima (F685/F730) was calculated by evaluating curve-fitted parameters. The variable chlorophyll fluorescence decrease ratio (Rfd) was determined from the FIK curves. Our study revealed that after 10 days of treatment, 10 ppm of dimethoate showed stimulatory response whereas 20, 40 and 80 ppm of dimethoate showed inhibitory response for growth and photosynthetic activity of pigeon pea plants, but after 20 and 30 days of treatment all the tested concentrations of dimethoate became inhibitory. This study clearly shows that dimethoate is highly toxic to the pigeon pea plant, even at very low concentration (10 ppm), if used for a prolonged duration. Our study may thus be helpful in determining the optimal dose of dimethoate in agricultural practices. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Passenger transport and household activity patterns

    DEFF Research Database (Denmark)

    Jørgensen, Kaj

    1997-01-01

    Review of Danish passenger transport patterns and analysis of energy consumption, emissions and safety impacts for selected typical households' travelling......Review of Danish passenger transport patterns and analysis of energy consumption, emissions and safety impacts for selected typical households' travelling...

  18. Analyzing injury severity of bus passengers with different movements.

    Science.gov (United States)

    Li, Duo; Zhao, Yifei; Bai, Qiang; Zhou, Bei; Ling, Hongbiao

    2017-07-04

    Though public transport vehicles are rarely involved in mass casualty accidents, when they are, the number of injuries and fatalities is usually high due to the high passenger capacity. Of the few studies that have been conducted on bus safety, the majority focused on vehicle safety features, road environmental factors, as well as driver characteristics. Nevertheless, few studies have attempted to investigate the underlying risk factors related to bus occupants. This article presents an investigation aimed at identifying the risk factors affecting injury severity of bus passengers with different movements. Three different passenger movement types including standing, seated, and boarding/alighting were analyzed individually using classification and regression tree (CART) method based on publicly available accident database of Great Britain. According to the results of exploratory analyses, passenger age and vehicle maneuver are associated with passenger injury severity in all 3 types of accidents. Moreover, the variable "skidding and overturning" is associated with injury severity of seated passengers and driver age is correlated with injury severity of standing and boarding/alighting passengers. The CART method shows its ability to identify and easily explain the complicated patterns affecting passenger injury severity. Several countermeasures to reduce bus passenger injury severity are recommended.

  19. Energy consumption and environmental effects of passenger transport modes. A life cycle study on passenger transport modes

    International Nuclear Information System (INIS)

    Kalenoja, H.

    1996-01-01

    Energy consumption and environmental effects of different passenger transport modes vary on the different stages of the fuel chain and during the production and maintenance of vehicles and infrastructure. Energy consumption and the environmental effects calculated per passenger mileage depend strongly on the vehicle occupancy. The properties of transport modes on urban areas and on the long distance transport have been evaluated in this study. The energy consumption and environmental effects calculated per passenger mileage have been assessed for passenger car, bus, tram, train, airplane and ferry. The emissions have been evaluated during the whole fuel chain. In this study only the airborne emissions have been taken into account. In the energy consumption calculations the energy content of vehicles and the infrastructure, energy consumption during the fuel chain and during the end use have been taken into consideration. (au)

  20. Potential of Pigeon Creek, San Salvador, Bahamas, as Nursery Habitat for Juvenile Reef Fish

    Directory of Open Access Journals (Sweden)

    Conboy, Ian Christopher

    2011-10-01

    Full Text Available This project assessed the significance of Pigeon Creek, San Salvador, Bahamas as a nursery habitat for coral reef fishes. Pigeon Creek’s perimeter is lined with mangrove and limestone bedrock. The bottom is sand or seagrass and ranges in depth from exposed at low tide to a 3-m deep, tide-scoured channel. In June 2006 and January 2007, fish were counted and their maturity was recorded while sampling 112 of 309 possible 50-m transects along the perimeter of the Pigeon Creek. Excluding silversides (Atherinidae, 52% of fish counted, six families each comprised >1% of the total abundance (Scaridae/parrotfishes, 35.3%; Lutjanidae/snappers, 23.9%; Haemulidae/grunts, 21.0%; Gerreidae/mojarras, 8.5%; Pomacentridae/damselfishes, 6.1%; Labridae/wrasses, 2.4%. There were few differences in effort-adjusted counts among habitats (mangrove, bedrock, mixed, sections (north, middle, southwest and seasons (summer 2006 and winter 2007. Red Mangrove (Rhizophora mangle, covering 68% of the perimeter was where 62% of the fish were counted. Snappers, grunts and parrotfishes are important food fishes and significant families in terms of reef ecology around San Salvador. Mangrove was the most important habitat for snappers and grunts; bedrock was most important for parrotfishes. The southwest section was important for snappers, grunts and parrotfishes, the north section for grunts and parrotfishes, and the middle section for snappers. Among the non-silverside fish counted, 91.2% were juveniles. These results suggest that Pigeon Creek is an important nursery for the coral reefs surrounding San Salvador and should be protected from potential disturbances.

  1. Modeling galactic extinction

    OpenAIRE

    Cecchi-Pestellini, C.; Mulas, G.; Casu, S.; Iatì, M. A.; Saija, R.; Cacciola, A.; Borghese, F.; Denti, P.

    2011-01-01

    We present a model for interstellar extinction dust, in which we assume a bimodal distribution of extinction carriers, a dispersion of core-mantle grains, supplemented by a collection of PAHs in free molecular form. We use state-of-the-art methods to calculate the extinction due to macroscopic dust particles, and the absorption cross-sections of PAHs in four different charge states. While successfull for most of observed Galactic extinction curves, in few cases the model cannot provide reliab...

  2. Stress-induced core temperature changes in pigeons (Columba livia).

    Science.gov (United States)

    Bittencourt, Myla de Aguiar; Melleu, Fernando Falkenburger; Marino-Neto, José

    2015-02-01

    Changes in body temperature are significant physiological consequences of stressful stimuli in mammals and birds. Pigeons (Columba livia) prosper in (potentially) stressful urban environments and are common subjects in neurobehavioral studies; however, the thermal responses to stress stimuli by pigeons are poorly known. Here, we describe acute changes in the telemetrically recorded celomatic (core) temperature (Tc) in pigeons given a variety of potentially stressful stimuli, including transfer to a novel cage (ExC) leading to visual isolation from conspecifics, the presence of the experimenter (ExpR), gentle handling (H), sham intracelomatic injections (SI), and the induction of the tonic immobility (TI) response. Transfer to the ExC cage provoked short-lived hyperthermia (10-20 min) followed by a long-lasting and substantial decrease in Tc, which returned to baseline levels 2 h after the start of the test. After a 2-hour stay in the ExC, the other potentially stressful stimuli evoked only weak, marginally significant hyperthermic (ExpR, IT) or hypothermic (SI) responses. Stimuli delivered 26 h after transfer to the ExC induced definite and intense increases in Tc (ExpR, H) or hypothermic responses (SI). These Tc changes appear to be unrelated to modifications in general activity (as measured via telemetrically recorded actimetric data). Repeated testing failed to affect the hypothermic responses to the transference to the ExC, even after nine trials and at 1- or 8-day intervals, suggesting that the social (visual) isolation from conspecifics may be a strong and poorly controllable stimulus in this species. The present data indicated that stress-induced changes in Tc may be a consistent and reliable physiological parameter of stress but that they may also show stressor type-, direction- and species-specific attributes. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Peak Shift in Pigeon and Human Categorisation

    OpenAIRE

    Aitken, Michael R. F.

    1996-01-01

    In a series of experiments, both pigeon and human subjects were trained to categorise two groups of confusable stimuli, with each category being made up of distortions of a ‘Prototype’. Once the subjects had successfully learned to categorise the training stimuli, they were tested on their responding to a variety of previously unseen stimuli: these were distortions of the Prototypes towards (‘Closer’ exemplars), or away from (‘Further’ exemplars), the other category, and the Prototypes thems...

  4. Arachidonic acid assimilation by thrombocytes from white carneau pigeons

    International Nuclear Information System (INIS)

    Saxon, D.J.; Blankenship, T.

    1986-01-01

    The metabolism of arachidonic acid was investigated using thrombocyte-enriched-plasma from RBWC and WC-II white carneau pigeons, which differ genetically in their susceptibility to atherosclerosis. Thrombocytes were incubated at 42 C with [ 14 C] arachidonate in Puck's solution. After a 1 hour labeling period the WC-II cells had taken up 69% and RBWC 77% of the [ 14 C]arachidonate from the medium. When 8,11,14-eicosatrienoic acid or 5,8,11,14,17-eicosapentaenoic acid were added to incubation media the [ 14 C] uptake was reduced in each type cell, with WC-II exhibiting the greatest effect. Release of [ 14 C]molecules from cells labeled with [ 14 ]Carachidonate was studied using calcium ionophore and indomethacin. Indomethacin inhibited [ 14 C] molecule release similarly in both RBWC and WC-II cells. Calcium ionophore was twice as effective in stimulating [ 14 C]molecule release from WC-II than RBWC cells. Therefore, the WE-II cells (from pigeons greater in susceptibility to atherosclerosis) are more sensitive to calcium ionophore than the REWC cells

  5. [Comfort of crew and passengers and atmospheric pressure, noise, wind speed in high-speed train of Shijiazhuang-Taiyuan passenger dedicated line].

    Science.gov (United States)

    Zhai, Yi-biao; Huo, Wei; Liu, Qiao-ying; Chen, Bao-shan; Zhang, Jin-long; Shi, Lei

    2012-11-01

    To explore the crew and passengers' comfort on the Shijiazhuang-Taiyuan passenger dedicated line and physical factors, such as air pressure, noise, wind speed. Comfort investigation of all the crew (n = 244) and passengers (n = 377) on the Shijiazhuang-Taiyuan passenger dedicated line at speed of 250 km/h and 200 km/h and the detection of the air pressure, noise and wind speed were performed in 2011. Significantly higher ratio of comfortable feeling, lower ratio of seriously discomfortable feeling were observed in crew and passengers at 200 km/h compared with those at 250 km/h (P noise in passengers at 200 km/h. No significant difference was observed in ear discomfort induced by air pressure and noise among crew, and the duration of disappearance of discomfortable feeling among passengers between 200 km/h and 250 km/h. The noise in carriages exceeded the related standard when the high-speed train passing through the tunnels. The individuals feel more comfortable at 200 km/h than 250 km/h in this line., which may be related with rapid variation of wind speed and noise when the train passes through the tunnels with high speed.

  6. External fixation to correct tarsal-metatarsal fracture in rock pigeon (Columba livia

    Directory of Open Access Journals (Sweden)

    Leandro Almeida Rui

    Full Text Available ABSTRACT Orthopedic conditions, such as bone fractures, are very common in avian medicine. External fixators have been considered the gold standard for birds, since they allow early movement of the limbs and minimal invasive surgery. Fractures in several bones have been successfully treated in pigeons. However, to the best of our knowledge, this case represents the first report of successful surgical repair of tarsal-metatarsal fracture in rock pigeon. External fixator was made with four 24G catheters, being inserted manually proximal and distal to the fracture and connected with polymerizable acrylic. Radiographic consolidation of fracture was observed 60 days post-surgery and anti-inflammatory and antibiotic protocols were successful on avoiding pain and infection during surgery and bone healing.

  7. LOOKING AT THE TYPES OF PIGEON HOUSES REMAINING IN ISFAHAN AND REVIVAL OPPORTUNITIES IN THESE BUILDINGS

    OpenAIRE

    BEIGHAMI, Mojgan; GHAHARI, Azadeh; PANAH, Hossein Hojjat; KALAEE, Ebrahim Amir

    2015-01-01

    Abstract. Pigeon Houses are  used in Iran in science simultaneously because of the diversity of forms and interior architecture and miracle and also it is used in the masterpieces of Iranian architecture which has always been interested by travelers and foreign tourists. Isfahan has long been considered for diversity of pigeon houses that produce natural fertilizer with high quality. Unfortunately, in recent years, much of this valuable building in the city is being destroyed . Hence, identif...

  8. Concurrent outbreak of Newcastle disease and Trichomoniasis in pigeons of Tehran

    Directory of Open Access Journals (Sweden)

    nariman sheykhi

    2014-08-01

    Full Text Available Newcastle disease is the most important viral disease that affected pigeons. The disease is characterized by sudden onset of anorexia and neurological symptoms in pigeon. Trichomonas gallinae causes trichomoniasis of pigeons in the upper gastrointestinal tract and the respiratory system. The symptoms of this disease include yellowish green fetid discharge from the mouth, diarrhea, emaciation, severe weakness and death. In the first 6 months of 1392, from a total of 32      suspicious cases from Tehran and its surrounding, swab samples of the mouth, pharynx and larynx of birds were prepared. The samples were studied for trichomonas infection. At necropsy, foci of white to cream color in the oral mucosa, pharynx, larynx and pharyngeal and tracheal mucous congestion associated with the presence of fetid fluid in the crop were observed. Also, general congestion of the carcass, urate deposition in the ureters, and the emptiness gastrointestinal tract was observed. For detection of Newcastle disease virus (NDV, samples of the trachea and spleen were collected and RT-PCR experiments were performed on the samples. Trichomonas was observed in the samples under the microscope. All of the 19 samples studied were considered positive to the presence of high virulence strain of the virus. Metronidazole and supportive therapies were used for treatment. Adherence to the principles of biosecurity, treatment or removal of trichomoniasis infected birds, and annual Newcastle disease vaccine are essential for the prevention of concurrent outbreak of these two diseases.

  9. Consumption-leisure tradeoffs in pigeons: Effects of changing marginal wage rates by varying amount of reinforcement.

    Science.gov (United States)

    Green, L; Kagel, J H; Battalio, R C

    1987-01-01

    Pigeons' rates of responding and food reinforcement under simple random-ratio schedules were compared with those obtained under comparable ratio schedules in which free food deliveries were added, but the duration of each food delivery was halved. These ratio-with-free-food schedules were constructed so that, were the pigeon to maintain the same rate of responding as it had under the simple ratio schedule, total food obtained (earned plus free) would remain unchanged. However, any reduction in responding would reduce total food consumption below that under the simple ratio schedule. These "compensated wage decreases" led to decreases in responding and decreases in food consumption, as predicted by an economic model of labor supply. Moreover, the reductions in responding increased as the ratio value increased (i.e., as wage rates decreased). Pigeons, therefore, substituted leisure for consumption. The relationship between these procedures and negative-income-tax programs is noted.

  10. How Important is the Integration of Public Passenger Transport

    Directory of Open Access Journals (Sweden)

    Mrníková Michaela

    2017-11-01

    Full Text Available The significance of the issue of an effective mode of passenger transport is currently increasing. On the one hand, there is the increasing economic demand of public passenger transport, on the other hand, there is the growing traffic share of individual automobile transport. The objective of the paper is to analyze public passenger transport without mutual integration of individual transport systems resulting in the fact that it is not sufficiently able to compete with individual automobile transport. It is proposed the integration of different modes of public passenger transport as a way to increase the competitiveness of public passenger transport. Aim of this paper is to analyze the individual elements of integration systems and describe why integration of public passenger transport systems is needed.

  11. Purification, crystallization and preliminary X-ray diffraction studies on avian haemoglobin from pigeon (Columba livia)

    International Nuclear Information System (INIS)

    Sathya Moorthy, Pon.; Neelagandan, K.; Balasubramanian, M.; Ponnuswamy, M. N.

    2009-01-01

    Crystallization of pigeon haemoglobin at low pH (5.5) and high ionic concentration (1 M) using the hanging-drop vapour-diffusion method is reported. Haemoglobin is a physiologically significant metalloprotein that is involved in the exchange of gases for sustaining life. The respiratory system of birds is unique and complex compared with that of mammals. Many investigations of avian haemoglobins have revealed the presence of inositol pentaphosphate (IP5), a principal allosteric effector that is involved in regulation of their function. Structural investigations of avian haemoglobins are presently not adequate to explain their function. Efforts have been made in this direction in order to understand the oxygen-binding affinity involved in adapting to hypoxia in avian haemoglobins. Fresh whole blood was collected from pigeon (Columba livia) and purified using a DEAE cellulose anion-exchange chromatographic column. Crystallization of pigeon haemoglobin was accomplished using the hanging-drop vapour-diffusion method using PEG 3350 as a precipitant in 50 mM sodium acetate buffer pH 5.5 with 1 M NaCl. Data collection was carried out using a MAR345 image-plate detector system. The crystals diffracted to 2 Å resolution. Pigeon haemoglobin crystallizes in a triclinic space group, with two whole biological molecules in the asymmetric unit and with unit-cell parameters a = 55.005, b = 65.528, c = 104.370 Å, α = 78.742, β = 89.819, γ = 65.320°

  12. Knowledge of the ordinal position of list items in pigeons.

    Science.gov (United States)

    Scarf, Damian; Colombo, Michael

    2011-10-01

    Ordinal knowledge is a fundamental aspect of advanced cognition. It is self-evident that humans represent ordinal knowledge, and over the past 20 years it has become clear that nonhuman primates share this ability. In contrast, evidence that nonprimate species represent ordinal knowledge is missing from the comparative literature. To address this issue, in the present experiment we trained pigeons on three 4-item lists and then tested them with derived lists in which, relative to the training lists, the ordinal position of the items was either maintained or changed. Similar to the findings with human and nonhuman primates, our pigeons performed markedly better on the maintained lists compared to the changed lists, and displayed errors consistent with the view that they used their knowledge of ordinal position to guide responding on the derived lists. These findings demonstrate that the ability to acquire ordinal knowledge is not unique to the primate lineage. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

  13. Comparison of airline passenger oxygen systems.

    Science.gov (United States)

    Byrne, N J

    1995-08-01

    The principal sources of oxygen for inflight passenger use, scheduled and unscheduled, are examined. Present practices of assessment of the passenger's "fitness to fly" are described. Three partner airlines, British Airways, U.S. Air, and Qantas, catering for more than 8000 oxygen requests annually, are compared. Analysis of customer use suggests that medical oxygen requests are frequently not clinically justified. The growth in demand, for both scheduled and unscheduled use of an expensive resource, supports the need for a "recommended best practice" among carriers. Passengers with respiratory disorders who will most benefit from inflight oxygen are vulnerable either to hypoxia or asthma.

  14. 150 Passenger Commercial Aircraft

    Science.gov (United States)

    Bucovsky, Adrian; Romli, Fairuz I.; Rupp, Jessica

    2002-01-01

    It has been projected that the need for a short-range mid-sized, aircraft is increasing. The future strategy to decrease long-haul flights will increase the demand for short-haul flights. Since passengers prefer to meet their destinations quickly, airlines will increase the frequency of flights, which will reduce the passenger load on the aircraft. If a point-to-point flight is not possible, passengers will prefer only a one-stop short connecting flight to their final destination. A 150-passenger aircraft is an ideal vehicle for these situations. It is mid-sized aircraft and has a range of 3000 nautical miles. This type of aircraft would market U.S. domestic flights or inter-European flight routes. The objective of the design of the 150-passenger aircraft is to minimize fuel consumption. The configuration of the aircraft must be optimized. This aircraft must meet CO2 and NOx emissions standards with minimal acquisition price and operating costs. This report contains all the work that has been performed for the completion of the design of a 150 passenger commercial aircraft. The methodology used is the Technology Identification, Evaluation, and Selection (TIES) developed at Georgia Tech Aerospace Systems Design laboratory (ASDL). This is an eight-step conceptual design process to evaluate the probability of meeting the design constraints. This methodology also allows for the evaluation of new technologies to be implemented into the design. The TIES process begins with defining the problem with a need established and a market targeted. With the customer requirements set and the target values established, a baseline concept is created. Next, the design space is explored to determine the feasibility and viability of the baseline aircraft configuration. If the design is neither feasible nor viable, new technologies can be implemented to open up the feasible design space and allow for a plausible solution. After the new technologies are identified, they must be evaluated

  15. Occurrence of Thermotolerant Campylobacter in Raw Poultry Meat, Environmental and Pigeon Stools Collected in Open-Air Markets.

    Science.gov (United States)

    Bellio, Alberto; Traversa, Amaranta; Adriano, Daniela; Bianchi, Daniela Manila; Colzani, Alberto; Gili, Stefano; Dondo, Alessandro; Gallina, Silvia; Grattarola, Carla; Maurella, Cristiana; Zoppi, Simona; Zuccon, Fabio; Decastelli, Lucia

    2014-08-28

    Campylobacteriosis was the most commonly reported zoonosis for confirmed human cases in European Union during 2011. Poultry meat was very often implicated in Campylobacter infections in humans. In Italy commerce of raw poultry meat is common in open-air markets: these areas can be considered at high risk of bacterial contamination due to the high presence birds like pigeons. The aim of this study was to collect data about the contamination by thermotolerant Campylobacter of raw poultry meat commercialised in open-air markets, of work-surfaces in contact with poultry meat and of pigeon stools sampled in the market areas in Turin, Northern Italy. Between September 2011 and December 2012, 86 raw poultry meat samples, 86 environmental swabs and 108 animal samples were collected in 38 open-air markets. Analysis were carried out according to ISO10272-1:2006 standard. C.coli was detected in 2.3% (2/86) of raw poultry meat samples, whereas no swab (0/86) resulted positive. Of pigeon stool 28% (30/107) was positive for C.jejuni (83.3% C.jejuni subsp . jejuni and 16.7% C.jejuni subsp . doylei ). C.jejuni subsp. jejuni was isolated from 1 dead pigeon . Our results showed lower rates of contamination than those reported at retail in Europe. Although samples were collected in areas at high risk of contamination, raw poultry meat and work surfaces reported a low level of presence of thermotolerant Campylobacter . The high percentage of C.jejuni isolated from pigeon stools showed the importance of a continuous application of preventive measures by the food business operators and the surveillance activity by the Competent Authority.

  16. Do release-site biases reflect response to the Earth's magnetic field during position determination by homing pigeons?

    Science.gov (United States)

    Mora, Cordula V; Walker, Michael M

    2009-09-22

    How homing pigeons (Columba livia) return to their loft from distant, unfamiliar sites has long been a mystery. At many release sites, untreated birds consistently vanish from view in a direction different from the home direction, a phenomenon called the release-site bias. These deviations in flight direction have been implicated in the position determination (or map) step of navigation because they may reflect local distortions in information about location that the birds obtain from the geophysical environment at the release site. Here, we performed a post hoc analysis of the relationship between vanishing bearings and local variations in magnetic intensity using previously published datasets for pigeons homing to lofts in Germany. Vanishing bearings of both experienced and naïve birds were strongly associated with magnetic intensity variations at release sites, with 90 per cent of bearings lying within +/-29 degrees of the magnetic intensity slope or contour direction. Our results (i) demonstrate that pigeons respond in an orderly manner to the local structure of the magnetic field at release sites, (ii) provide a mechanism for the occurrence of release-site biases and (iii) suggest that pigeons may derive spatial information from the magnetic field at the release site that could be used to estimate their current position relative to their loft.

  17. Two types of external fixators to correct humeral fracture in domestic pigeons

    International Nuclear Information System (INIS)

    Dalmolin, F.; Schossler, J.E.; Bertoletti, B.; Vasconcelos, A.; Muller, D.; Schossler, D.R.; Gomes, K.

    2007-01-01

    This paper was aimed at evaluating two changes in the external fixators for osteosynthesis of the humeral fracture that induce the correction of the humeral fracture in pigeons. The reduction of diaphyseal fracture was made with an intramedulary pin associated to another perpendicular one inserted into the distal segment (Group A - GA); in the Group B (GB) an additional pin was used in the proximal fragment. All the pigeons were evaluated clinically and radiographically up to 60 days, except for four of each group which were submitted to euthanasia at 15, 22, 29 and 36 days for the macro and microscope exams. The flight test was successful in all pigeons. The bone calus was radiografically visible only in the GA; the mean time and the standard deviation for flight was 32.25 ± 6.5 days for the GA and 39.8 ± 3.83 for the GB. The mean time and standard deviation for fracture healing was 36 ± 0 days in the GA and 34 ± 3.4 in the GB. The two types of external fixator evaluated were efficient to stabilized the fracture site allowing complete consolidation and return to function. The use of the external fixator with two perpendicular pins provides more stability at the fracture site although it is necessary more time for the surgery procedure [pt

  18. Phylogenetic and Pathotypic Characterization of a Newcastle Disease Virus Strain Isolated from Ducks and Pigeons in Hubei, China

    Directory of Open Access Journals (Sweden)

    Y Wang

    Full Text Available ABSTRACT Newcastle disease is a highly contagious disease responsible for major outbreaks and considerable economic losses in the poultry industry in China. There is still little information available regarding gene characterization of the NDV, especially in ducks and pigeons. Therefore, the aim of this study was to investigate NDV isolated from ducks and pigeons in Hubei, China. In this study, three NDVs from ducks and pigeons were isolated between 2013 and 2015.The fusion protein (F gene of the NDV isolates was sequenced and phylogenetically analyzed. The clinical signs and gross histopathological lesions were examined. Phylogenetic analysis of these strains indicated that all the sequences are classified as genotype II. The isolates shared a 112 G-R-Q-G-R-L 117motif at the F protein cleavage site, indicating that these three isolates strains are lentogenic. Necropsy and histopathology showed the typical pathological changes. It was concluded that commercial ducks and pigeons in Hubei province carry lentogenic NDV strains with regular genetic divergence, indicating that these species may act as the main reservoirs of NDV in poultry. Therefore, strategies and surveillance should be undertaken to reduce the risk of ND outbreaks.

  19. Long-term maintenance of immediate or delayed extinction is determined by the extinction-test interval

    OpenAIRE

    Johnson, Justin S.; Escobar, Martha; Kimble, Whitney L.

    2010-01-01

    Short acquisition-extinction intervals (immediate extinction) can lead to either more or less spontaneous recovery than long acquisition-extinction intervals (delayed extinction). Using rat subjects, we observed less spontaneous recovery following immediate than delayed extinction (Experiment 1). However, this was the case only if a relatively long extinction-test interval was used; a relatively short extinction-test interval yielded the opposite result (Experiment 2). Previous data appear co...

  20. Risky Choice in Pigeons and Humans: A Cross-Species Comparison

    Science.gov (United States)

    Lagorio, Carla H.; Hackenberg, Timothy D.

    2010-01-01

    Pigeon and human subjects were given repeated choices between variable and adjusting delays to token reinforcement that titrated in relation to a subject's recent choice patterns. Indifference curves were generated under two different procedures: "immediate exchange," in which a token earned during each trial was exchanged immediately for access…

  1. Selecting for extinction: nonrandom disease-associated extinction homogenizes amphibian biotas.

    Science.gov (United States)

    Smith, Kevin G; Lips, Karen R; Chase, Jonathan M

    2009-10-01

    Studying the patterns in which local extinctions occur is critical to understanding how extinctions affect biodiversity at local, regional and global spatial scales. To understand the importance of patterns of extinction at a regional spatial scale, we use data from extirpations associated with a widespread pathogenic agent of amphibian decline, Batrachochytrium dendrobatidis (Bd) as a model system. We apply novel null model analyses to these data to determine whether recent extirpations associated with Bd have resulted in selective extinction and homogenization of diverse tropical American amphibian biotas. We find that Bd-associated extinctions in this region were nonrandom and disproportionately, but not exclusively, affected low-occupancy and endemic species, resulting in homogenization of the remnant amphibian fauna. The pattern of extirpations also resulted in phylogenetic homogenization at the family level and ecological homogenization of reproductive mode and habitat association. Additionally, many more species were extirpated from the region than would be expected if extirpations occurred randomly. Our results indicate that amphibian declines in this region are an extinction filter, reducing regional amphibian biodiversity to highly similar relict assemblages and ultimately causing amplified biodiversity loss at regional and global scales.

  2. Three-dimensional organization of vestibular related eye movements to rotational motion in pigeons

    Science.gov (United States)

    Dickman, J. D.; Beyer, M.; Hess, B. J.

    2000-01-01

    During rotational motions, compensatory eye movement adjustments must continually occur in order to maintain objects of visual interest as stable images on the retina. In the present study, the three-dimensional organization of the vestibulo-ocular reflex in pigeons was quantitatively examined. Rotations about different head axes produced horizontal, vertical, and torsional eye movements, whose component magnitude was dependent upon the cosine of the stimulus axis relative to the animal's visual axis. Thus, the three-dimensional organization of the VOR in pigeons appears to be compensatory for any direction of head rotation. Frequency responses of the horizontal, vertical, and torsional slow phase components exhibited high pass filter properties with dominant time constants of approximately 3 s.

  3. Necrotizing hepatitis in a domestic pigeon (Columba livia).

    Science.gov (United States)

    Himmel, L; O'Connor, M; Premanandan, C

    2014-11-01

    An adult male domestic pigeon (Columba livia) was presented for necropsy following natural death after a period of chronic weight loss and severe intestinal ascariasis. Histopathologic examination of the liver found moderate to marked, multifocal necrotizing hepatitis with large, basophilic intranuclear inclusion bodies. Transmission electron microscopy of affected hepatocytes demonstrated numerous intra- and perinuclear icosahedral virions arranged in a lattice structure, consistent with adenoviral infection. © The Author(s) 2014.

  4. Passenger safety, health, and comfort: a review.

    Science.gov (United States)

    Rayman, R B

    1997-05-01

    Since the birth of aviation medicine approximately 80 yrs ago, practitioners and scientists have given their attention primarily to flight deck crew, cabin crew, and ground support personnel. However, in more recent years we have broadened our horizons to include the safety, health, and comfort of passengers flying commercial aircraft. This will be even more compelling as more passengers take to the air in larger aircraft and flying longer hours to more distant destinations. Further, we can expect to see more older passengers because people in many countries are living longer, healthier lives. The author first discusses the stresses imposed by ordinary commercial flight upon travelers such as airport tumult, barometric pressure changes, immobility, jet lag, noise/ vibration, and radiation. Medical considerations are next addressed describing inflight illness and medical care capability aboard U.S. air carriers. Passenger safety, cabin air quality, and the preventive medicine aspects of air travel are next reviewed in the context of passenger safety, health, and comfort. Recommendations are addressed to regulator agencies, airlines aircraft manufacturers, and the aerospace medicine community.

  5. Metal Accumulation, Blood δ-Aminolevulinic Acid Dehydratase Activity and Micronucleated Erythrocytes of Feral pigeons (Columba Livia Living Near Former Lead-Zinc Smelter “ Trepça” – Kosovo

    Directory of Open Access Journals (Sweden)

    Elezaj I. R.

    2013-04-01

    Full Text Available The concentration of lead in blood and tibia (Pb, zinc (Zn and cupper (Cu in tibia, blood δ- aminolevulinic acid dehydratase (ALA-D; EC: 4.2.1.24 activity, hematocrit value (Hct and micronuclei frequency (MN of peripheral erythrocytes have been determinated in three different populations of feral pigeons (Columba livia; forma urbana and forma domestica, collected in Mitrovica town (situated close to smelter “Trepça”, down closed in 2000 year and in rural area (Koshare willage . The blood lead level in feral pigeons from Mitrovica (forma urbana was 3 times higher (149.6; 50.5 μg% in comparison with that in feral pigeons from Mitrovica (forma domestica and 27.7 times higher (5.4 μg% in comparison with pigeons from rural area. The Pb concentration of tibia of feral pigeons (froma urbana and forma domestica, from Mitrovica town was significantly higher (P<0.001 in comparison with control. The concentration of Zn in tibia of feral pigeons from Mitrovica town (forma urbana, was significantly higher (P<0.006 in comparison with control. The blood ALA-D activity of feral pigeons from Mitrovica town (forma urbana and froma domestica, was significantly inhibited in comparison with control. The blood ALA-D activity of feral pigeons –forma urbana from Mitrovica town was significantly inhibited (P<0.001 in comparison with the blood ALA-D activity of feral pigeons-forma domestica from Mitrovica town. The erythrocyte MN frequency of feral pigeons from Mitrovica was significantly higher (P <0.001 in comparison with controls. The smelter “Trepça” ten year after closed down pose a threat to the local environment, biota and people’s health.

  6. Change Blindness in Pigeons (Columba livia: the Effects of Change Salience and Timing

    Directory of Open Access Journals (Sweden)

    Walter Troy Herbranson

    2015-08-01

    Full Text Available Change blindness is a well-established phenomenon in humans, in which plainly visible changes in the environment go unnoticed. Recently a parallel change blindness phenomenon has been demonstrated in pigeons. The reported experiment follows up on this finding by investigating whether change salience affects change blindness in pigeons the same way it affects change blindness in humans. Birds viewed alternating displays of randomly generated lines back-projected onto three response keys, with one or more line features on a single key differing between consecutive displays. Change salience was manipulated by varying the number of line features that changed on the critical response key. Results indicated that change blindness is reduced if a change is made more salient, and this matches previous human results. Furthermore, accuracy patterns indicate that pigeons’ effective search area expanded over the course of a trial to encompass a larger portion of the stimulus environment. Thus, the data indicate two important aspects of temporal cognition. First, the timing of a change has a profound influence on whether or not that change will be perceived. Second, pigeons appear to engage in a serial search for changes, in which additional time is required to search additional locations.

  7. Interstellar extinction correlations

    International Nuclear Information System (INIS)

    Jones, A.P.; Williams, D.A.; Duley, W.W.

    1987-01-01

    A recently proposed model for interstellar grains in which the extinction arises from small silicate cores with mantles of hydrogenated amorphous carbon (HAC or α-C:H), and large, but thinly coated, silicate grains can successfully explain many of the observed properties of interstellar dust. The small silicate cores give rise to the 2200 A extinction feature. The extinction in the visual is produced by the large silicates and the HAC mantles on the small cores, whilst the far UV extinction arises in the HAC mantles with a small contribution form the silicate grains. The grain model requires that the silicate material is the more resilient component and that variations in the observed extinction from region to region are due to the nature and depletion of the carbon in the HAC mantles. (author)

  8. Lead Effect on Aminolevulinic Acid Dehydratase Activity of Feral Pigeon (Columba livia in Drenas

    Directory of Open Access Journals (Sweden)

    Albana Plakiqi Milaimi

    2015-09-01

    Full Text Available This study was aimed to investigate the effects of environmental pollution with heavy metals from ferro-nickel smelter on Aminolevulinic Acid Dehydratase (ALAD activity, and to analyze the blood lead level of feral pigeon (Columba livia in ferro-nickel smelter courtyard in Drenas City, Republic of Kosovo. For this purpose, twenty specimens of feral pigeon (20 birds, males and females, were collected in Drenas city which were living in ferro-nickel smelter courtyard, and 20 specimens in Lubizhdë village as control group (non-contaminated area. ALAD activity in Drenas group was significantly inhibited (P<0.001, compared with ALAD activity of controls. The blood lead level was significantly increased (P=0.015 compared to control group. Correlation between ALAD and blood lead level in Drenas group was negative (r=-0.117; P>0.050 and positive in Lubizhdë group (r=0.452; P> 0.050, but not in significant difference between the input groups. Feral pigeons can play an important role as bioindicators, which can used to monitor the environmental pollution with heavy metals that may originate from Nickel metallurgy.

  9. The potential of pigeon pea (Cajanus cajan) beverage as an anti-diabetic functional drink

    Science.gov (United States)

    Ariviani, S.; Affandi, D. R.; Listyaningsih, E.; Handajani, S.

    2018-01-01

    The number of patients with diabetes continues to increase. Diabetes complications might induce serious diseases such as kidney, nervous, cardiovascular diseases and stroke. Diabetic complications can be prevented by keeping blood glucose and cholesterol at normal levels. This study aims to determine the potential of pigeon pea beverage for lowering glucose and total cholesterol plasma levels and increasing the antioxidant status of diabetic-hypercholesterolemia rats. The research was conducted using 18 Sprague Dawley male rats aged 3 months old with an average body weight of 154 g. The rats were divided into three groups: normal group, D-H group (diabetic-hypercholesterolemia group), and pigeon pea beverage group. The results showed that pigeon pea beverage diet showed hypoglycemic and hypocholesterolemic activities, and could improve the antioxidant status of diabetic-hypercholesterolemia rats. Plasma glucose and total cholesterol levels of diabetic-hypercholesterolemia rats decreased 33.86% and 19.78% respectively. The improvement of the plasma antioxidant status was indicated by the decrease of plasma MDA (malondialdehyde) level, reaching 37.16%. The research result provides an alternative to diabetes management by using the local bean as an anti-diabetic functional drink.

  10. Genomic diversity and evolution of the head crest in the rock pigeon.

    Science.gov (United States)

    Shapiro, Michael D; Kronenberg, Zev; Li, Cai; Domyan, Eric T; Pan, Hailin; Campbell, Michael; Tan, Hao; Huff, Chad D; Hu, Haofu; Vickrey, Anna I; Nielsen, Sandra C A; Stringham, Sydney A; Hu, Hao; Willerslev, Eske; Gilbert, M Thomas P; Yandell, Mark; Zhang, Guojie; Wang, Jun

    2013-03-01

    The geographic origins of breeds and the genetic basis of variation within the widely distributed and phenotypically diverse domestic rock pigeon (Columba livia) remain largely unknown. We generated a rock pigeon reference genome and additional genome sequences representing domestic and feral populations. We found evidence for the origins of major breed groups in the Middle East and contributions from a racing breed to North American feral populations. We identified the gene EphB2 as a strong candidate for the derived head crest phenotype shared by numerous breeds, an important trait in mate selection in many avian species. We also found evidence that this trait evolved just once and spread throughout the species, and that the crest originates early in development by the localized molecular reversal of feather bud polarity.

  11. The comparison of assessment of pigeon semen motility and sperm concentration by conventional methods and the CASA system (HTM IVOS).

    Science.gov (United States)

    Klimowicz, M D; Nizanski, W; Batkowski, F; Savic, M A

    2008-07-01

    The aim of these experiments was to compare conventional, microscopic methods of evaluating pigeon sperm motility and concentration to those measured by computer-assisted sperm analysis (CASA system). Semen was collected twice a week from two groups of pigeons, each of 40 males (group I: meat-type breed; group II: fancy pigeon) using the lumbo-sacral and cloacal region massage method. Ejaculates collected in each group were diluted 1:100 in BPSE solution and divided into two equal samples. One sample was examined subjectively by microscope and the second one was analysed using CASA system. The sperm concentration was measured by CASA using the anti-collision (AC) system and fluorescent staining (IDENT). There were not any significant differences between the methods of evaluation of sperm concentration. High positive correlations in both groups were observed between the sperm concentration estimated by Thom counting chamber and AC (r=0.87 and r=0.91, respectively), and between the sperm concentration evaluated by Thom counting chamber and IDENT (r=0.85 and r=0.90, respectively). The mean values for CASA measurement of proportion of motile spermatozoa (MOT) and progressive movement (PMOT) were significantly lower than the values estimated subjectively in both groups of pigeons (pCASA system is very rapid, objective and sensitive method in detecting subtle motility characteristics as well as sperm concentration and is recommended for future research into pigeon semen.

  12. Passenger Perspectives in Railway Timetabling: A Literature Review

    DEFF Research Database (Denmark)

    Jensen, Jens Parbo; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2016-01-01

    When looking at railway planning, a discrepancy exists between planners who focus on the train operations and publish fixed railway schedules, and passengers who look not only at the schedules but also at the entirety of their trip, from access to waiting to on-board travel and egress. Looking...... with fluctuating passenger demand. A key aspect is the robustness of railway timetables. Empirical evidence indicates that passengers give more importance to travel time certainty than travel time reductions, as passengers associate an inherent disutility with travel time uncertainty. This disutility may...... be broadly interpreted as an anxiety cost for the need for having contingency plans in case of disruptions, and may be looked at as the motivator for the need for delay-robust railway timetables. Interestingly, passenger-oriented optimisation studies considering robustness in railway planning typically limit...

  13. Methods to estimate railway capacity and passenger delays

    DEFF Research Database (Denmark)

    Landex, Alex

    that an evaluation of passenger delays obtained with simulation software (in this case RailSys) and the passenger delay model is comparable with the daily operation of the Copenhagen suburban railway network. Using a microscopic simulation model, the thesis demonstrates that it is possible to compare travel times...... of additional travel time. The differences between the different kinds of delay (train delays, passenger delays and scheduled waiting time) are illustrated through simple, but representative, case examples in CHAPTER 10. The examples demonstrate that 3rd generation passenger delay models are more realistic than...... depend on the given infrastructure and timetable and can result in longer travel times for trains and passengers. Furthermore, the thesis shows that the network effects can result in reduced capacity as some trains or train services can make it impossible to operate other planned/desired trains or train...

  14. Hippocampal lesions, contextual retrieval, and autoshaping in pigeons.

    Science.gov (United States)

    Richmond, Jenny; Colombo, Michael

    2002-02-22

    Both pigeons and rats with damage to the hippocampus are slow to acquire an autoshaped response and emit fewer overall responses than control animals. Experiment 1 explored the possibility that the autoshaping deficit was due to an impairment in contextual retrieval. Pigeons were trained for 14 days on an autoshaping task in which a red stimulus was followed by reinforcement in context A, and a green stimulus was followed by reinforcement in context B. On day 15, the subjects were given a context test in which the red and green stimuli were presented simultaneously in context A and then later in context B. Both control and hippocampal animals showed context specificity, that is, they responded more to the red stimulus in context A and to the green stimulus in context B. In Experiment 2 we video-recorded the control and hippocampal animals performing the autoshaping task. Hippocampal animals tended to miss-peck the key more often than control animals. In addition, the number of missed pecks increased across days for hippocampal animals but not for control animals, suggesting that while the control animals increased their pecking accuracy, the hippocampal animals actually decreased their pecking accuracy. Our findings suggest that impairments in moving through space may underlie the hippocampal autoshaping deficit.

  15. Interaction rules underlying group decisions in homing pigeons

    Science.gov (United States)

    Pettit, Benjamin; Perna, Andrea; Biro, Dora; Sumpter, David J. T.

    2013-01-01

    Travelling in groups gives animals opportunities to share route information by following cues from each other's movement. The outcome of group navigation will depend on how individuals respond to each other within a flock, school, swarm or herd. Despite the abundance of modelling studies, only recently have researchers developed techniques to determine the interaction rules among real animals. Here, we use high-resolution GPS (global positioning system) tracking to study these interactions in pairs of pigeons flying home from a familiar site. Momentary changes in velocity indicate alignment with the neighbour's direction, as well as attraction or avoidance depending on distance. Responses were stronger when the neighbour was in front. From the flocking behaviour, we develop a model to predict features of group navigation. Specifically, we show that the interactions between pigeons stabilize a side-by-side configuration, promoting bidirectional information transfer and reducing the risk of separation. However, if one bird gets in front it will lead directional choices. Our model further predicts, and observations confirm, that a faster bird (as measured from solo flights) will fly slightly in front and thus dominate the choice of homing route. Our results explain how group decisions emerge from individual differences in homing flight behaviour. PMID:24068173

  16. Characterization of Five Fungal Endophytes Producing Cajaninstilbene Acid Isolated from Pigeon Pea [Cajanus cajan (L.) Millsp.

    OpenAIRE

    Gao, Yuan; Zhao, Jin Tong; Zu, Yuan Gang; Fu, Yu Jie; Wang, Wei; Luo, Meng; Efferth, Thomas

    2011-01-01

    Five fungal endophytes (K4, K5, K6, K9, K14) producing Cajaninstilbene acid (CSA, 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid) were isolated from the roots of pigeon pea [Cajanus cajan (L.) Millsp.]. CSA is responsible for the prominent pharmacological activities in pigeon pea. The amount of CSA in culture solution varied among the five fungal endophytes. K4 produced the highest levels of CSA (1037.13 µg/L) among the endophytes tested after incubation for five days. Both morphologi...

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

    Directory of Open Access Journals (Sweden)

    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

  18. Genetic diversity of the Japanese wood pigeon, Columba janthina, endemic to islands of East Asia, estimated by newly developed microsatellite markers.

    Science.gov (United States)

    Ando, Haruko; Kaneko, Shingo; Suzuki, Hajime; Horikoshi, Kazuo; Takano, Hajime; Ogawa, Hiroko; Isagi, Yuji

    2011-12-01

    The Japanese wood pigeon Columba janthina is endemic to islands of East Asia and is listed as Near Threatened by the International Union for Conservation of Nature (IUCN). One subspecies, C. janthina nitens, in particular, is at the greatest risk of extinction due to its small population size. To reduce the extinction risk of C. janthina, it is important to understand the species' present genetic status and to develop an appropriate conservation plan based on genetic data. We developed seven new microsatellite markers for two subspecies of C. janthina: C. janthina janthina and C. janthina nitens. We also confirmed the cross-use of one microsatellite marker developed for Columba livia var. domestica. Seven loci were polymorphic in C. janthina janthina, while two loci were polymorphic in C. janthina nitens. Using the markers, we performed preliminary analysis of genetic diversity and genetic structure within each subspecies. The expected heterozygosity ranged from 0.00 to 0.64 in C. janthina janthina and from 0.00 to 0.08 in C. janthina nitens. Each subspecies and each population within C. janthina janthina had different allele frequencies. C. janthina nitens exhibited far lower genetic diversity than C. janthina janthina. Furthermore, C. janthina nitens appears to have experienced strong genetic drift from a common ancestral population, inferred by STRUCTURE analysis. The markers described here may be useful for investigating genetic diversity and genetic structure of C. janthina populations, and could be used to estimate appropriate evolutionary significant unit and to guide development of a captive breeding program based on genetic information.

  19. Facilitation of extinction and re-extinction of operant behavior in mice by chlordiazepoxide and D-cycloserine.

    Science.gov (United States)

    Leslie, Julian C; Norwood, Kelly

    2013-05-01

    The aim was to compare operant extinction with re-extinction following re-acquisition and to investigate neuropharmacological mechanisms through administration of drugs potentiating GABAergic or glutamatergic systems. Groups of C57Bl/6 mice were trained to lever press for food on a fixed ratio schedule, then extinguished with or without pre-session chlordiazepoxide or post-session d-cycloserine administration (15mg/kg in each case), then retrained to lever press for food, then re-extinguished with or without pre-session chlordiazepoxide or post-session d-cycloserine. Under vehicle injections, extinction and re-extinction curves were indistinguishable, but drug treatments showed that there was less resistance to extinction in the re-extinction phase. Chlordiazepoxide facilitated extinction and re-extinction, with an earlier effect during re-extinction. d-Cycloserine also facilitated extinction and re-extinction, with some evidence of an earlier effect during re-extinction. These results replicate and extend earlier findings with operant extinction, but differ from some previous reports of d-cycloserine on re-extinction of Pavlovian conditioned fear. Implications for accounts of the similarities and differences between neural mechanisms of extinction following either Pavlovian or operant conditioning, and applications of these findings, are discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Long-Term Maintenance of Immediate or Delayed Extinction Is Determined by the Extinction-Test Interval

    Science.gov (United States)

    Johnson, Justin S.; Escobar, Martha; Kimble, Whitney L.

    2010-01-01

    Short acquisition-extinction intervals (immediate extinction) can lead to either more or less spontaneous recovery than long acquisition-extinction intervals (delayed extinction). Using rat subjects, we observed less spontaneous recovery following immediate than delayed extinction (Experiment 1). However, this was the case only if a relatively…

  1. the role of the pigeon in the first world war

    African Journals Online (AJOL)

    plt

    Despite a stream of publications acknowledging the war-time role of non- ... discourse on the military or of bridging the “long-existing gap in the larger narrative ... the pigeon memorialisation movement in general and in France and Belgium in ...... a short time: New perspectives on the Anglo-Boer War, Pretoria: Nexus.

  2. Pigeon fancier’s lung – An under-diagnosed cause of severely debilitating and chronic breathlessness

    Directory of Open Access Journals (Sweden)

    Vishal Chopra

    2017-07-01

    Full Text Available Pigeon fanciers lung or Bird fanciers lung (BFL is one of the common and preventable causes of hypersensitivity pneumonitis. It is an under diagnosed cause of severe incapacitating breathlessness and can be acute, sub-acute or chronic. We report a case of 53 year old female who presented with severe chronic breathlessness due to regular exposure to pigeons for last 35 years. Clinicians should take a detailed history of exposure in patients with unexplained breathlessness as the avoidance of exposure to the antigens can reverse the disease preventing the morbidity and mortality of the patient.

  3. Stress analysis on passenger deck due to modification from passenger ship to vehicle-carrying ship

    Science.gov (United States)

    Zubaydi, A.; Sujiatanti, S. H.; Hariyanto, T. R.

    2018-03-01

    Stress is a basic concept in learning about material mechanism. The main focus that needs to be brought to attention in analyzing stress is strength, which is the structural capacity to carry or distribute loads. The structural capacity not only measured by comparing the maximum stress with the material’s yield strength but also with the permissible stress required by the Indonesian Classification Bureau (BKI), which certainly makes it much safer. This final project analyzes stress in passenger deck that experiences modification due to load changes, from passenger load to vehicle one, carrying: 6-wheels truck with maximum weight of 14 tons, a passenger car with maximum weight of 3.5 tons, and a motorcycle with maximum weight of 0.4 tons. The deck structure is modelled using finite element software. The boundary conditions given to the structural model are fix and simple constraint. The load that works on this deck is the deck load which comes from the vehicles on deck with three vehicles’ arrangement plans. After that, software modelling is conducted for analysis purpose. Analysis result shows a variation of maximum stress that occurs i.e. 135 N/mm2, 133 N/mm2, and 152 N/mm2. Those maximum stresses will not affect the structure of passenger deck’s because the maximum stress that occurs indicates smaller value compared to the Indonesian Classification Bureau’s permissible stress (175 N/mm2) as well as the material’s yield strength (235 N/mm2). Thus, the structural strength of passenger deck is shown to be capable of carrying the weight of vehicles in accordance with the three vehicles’ arrangement plans.

  4. Rescheduling of Railway Rolling Stock with Dynamic Passenger Flows

    NARCIS (Netherlands)

    L.G. Kroon (Leo); G. Maróti (Gábor); L.K. Nielsen (Lars Kjaer)

    2010-01-01

    textabstractTraditional rolling stock rescheduling applications either treat passengers as static objects whose influence on the system is unchanged in a disrupted situation, or they treat passenger behavior as a given input. In case of disruptions however, we may expect the flow of passengers to

  5. 49 CFR 541.5 - Requirements for passenger motor vehicles.

    Science.gov (United States)

    2010-10-01

    ... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE THEFT PREVENTION STANDARD § 541.5 Requirements for passenger motor vehicles. (a) Each passenger motor vehicle subject to... 49 Transportation 6 2010-10-01 2010-10-01 false Requirements for passenger motor vehicles. 541.5...

  6. Assessment of beneficial role of an insectivorous bird, jungle babbler (Turdoides striatus predation, on Helicoverpa armigera infesting pigeon pea (Cajanus cajan crop

    Directory of Open Access Journals (Sweden)

    Bharucha Bhavna

    2010-06-01

    Full Text Available Jungle babbler (Turdoides striatus, a widely spread sub-tropical insectivorous passerine is considered beneficial to agro-ecosystem, as they devour voraciously on insect matter especially Helicoverpa armigera, the gram pod borer, a notorious pest infesting and causing heavy loses to crops like pigeon pea (Cajanus cajan which is a vital crop of semi-arid tropical and subtropical farming system, providing high quality vegetable protein. Helicoverpa is known to feed on flowers, pods, and seeds and is the most important biotic constraint affecting pigeon pea yields. Jungle babblers have a peculiar foraging style which helps expose the Helicoverpa larvae as well as pupae through various phenological stages of pigeon pea. For comparative assessment of their beneficial role and as a possible bio control agent, in Baroda city (State of Gaujarat, India, was studied, two crops of pigeon pea (insecticide treated and untreated (control were selected. In both treated and control crops, the number of jungle babblers were maximum in pigeon pea fields during october and november in both small pod stage and large pod stage which had heavy infestation of Helicoverpa. Least number of birds was seen during the flowering stage in September. Later in treatment crop three applications of Dunnate and Monocrotophos insecticide spray was done after which the pest population decreased which is reflected in number of birds in the field, while the bird number in control crops grew since insecticide spray was not done and number of larvae increased with the stage of the crop. Along with the main crop pigeon pea, comparative study was also done to see the food preference by these birds in crops like sorghum, maize, cow pea and ploughed and unploughed fields. Maximum number of birds was seen in unploughed field and least in sorghum suggesting that Helicoverpa is preferred food over sorghum grains thus pigeon pea

  7. Growth curves and age-related changes in carcass characteristics, organs, serum parameters, and intestinal transporter gene expression in domestic pigeon (Columba livia).

    Science.gov (United States)

    Gao, C Q; Yang, J X; Chen, M X; Yan, H C; Wang, X Q

    2016-04-01

    Two experiments were conducted to fit growth curves, and determine age-related changes in carcass characteristics, organs, serum biochemical parameters, and gene expression of intestinal nutrient transporters in domestic pigeon (Columba livia). In experiment 1, body weight (BW) of 30 pigeons was respectively determined at 1, 3, 7, 14, 21, 28, and 35 days old to fit growth curves and to describe the growth of pigeons. In experiment 2, eighty-four 1-day-old squabs were grouped by weight into 7 groups. On d 1, 3, 7, 14, 21, 28, and 35, twelve birds from each group were randomly selected for slaughter and post-slaughter analysis. The results showed that BW of pigeons increased rapidly from d 1 to d 28 (a 25.7-fold increase), and then had little change until d 35. The Logistic, Gompertz, and Von Bertalanffy functions can all be well fitted with the growth curve of domestic pigeons (R2>0.90) and the Gompertz model showed the highest R2value among the models (R2=0.9997). The equation of Gompertz model was Y=507.72×e-(3.76exp(-0.17t))(Y=BW of pigeon (g); t=time (day)). In addition, breast meat yield (%) increased with age throughout the experiment, whereas the leg meat yield (%) reached to the peak on d 14. Serum total protein, albumin, globulin, and glucose concentration were increased with age, whereas serum uric acid concentration was decreased (P<0.05). Furthermore, the gene expressions of nutrient transporters (y+LAT2, LAT1, B0AT1, PepT1, and NHE2) in jejunum of pigeon were increased with age. The results of correlation analysis showed the gene expressions of B0AT1, PepT1, and NHE2 had positive correlations with BW (0.73pigeon. And the various physiological and functional properties of organs, serum profiles, and gene expression of nutrient transporters in small intestine might cause the differences in their development patterns. © 2016 Poultry

  8. Young drivers and their young passengers.

    NARCIS (Netherlands)

    2015-01-01

    More than one-third of all fatalities among car passengers occurs in the 10-24-year age group. The majority of these young passengers die in a car driven by an 18 to 24-year old. Compared with the composition of the population, these are high proportions, yet the exposure (for example in distance

  9. Extinction and the fossil record

    Science.gov (United States)

    Sepkoski, J. J. Jr; Sepkoski JJ, ,. J. r. (Principal Investigator)

    1994-01-01

    The author examines evidence of mass extinctions in the fossil record and searches for reasons for such large extinctions. Five major mass extinctions eliminated at least 40 percent of animal genera in the oceans and from 65 to 95 percent of ocean species. Questions include the occurrence of gradual or catastrophic extinctions, causes, environment, the capacity of a perturbation to cause extinctions each time it happens, and the possibility and identification of complex events leading to a mass extinction.

  10. Extinctions. Paleontological baselines for evaluating extinction risk in the modern oceans.

    Science.gov (United States)

    Finnegan, Seth; Anderson, Sean C; Harnik, Paul G; Simpson, Carl; Tittensor, Derek P; Byrnes, Jarrett E; Finkel, Zoe V; Lindberg, David R; Liow, Lee Hsiang; Lockwood, Rowan; Lotze, Heike K; McClain, Craig R; McGuire, Jenny L; O'Dea, Aaron; Pandolfi, John M

    2015-05-01

    Marine taxa are threatened by anthropogenic impacts, but knowledge of their extinction vulnerabilities is limited. The fossil record provides rich information on past extinctions that can help predict biotic responses. We show that over 23 million years, taxonomic membership and geographic range size consistently explain a large proportion of extinction risk variation in six major taxonomic groups. We assess intrinsic risk-extinction risk predicted by paleontologically calibrated models-for modern genera in these groups. Mapping the geographic distribution of these genera identifies coastal biogeographic provinces where fauna with high intrinsic risk are strongly affected by human activity or climate change. Such regions are disproportionately in the tropics, raising the possibility that these ecosystems may be particularly vulnerable to future extinctions. Intrinsic risk provides a prehuman baseline for considering current threats to marine biodiversity. Copyright © 2015, American Association for the Advancement of Science.

  11. Association of MYF5 and KLF15 gene polymorphisms with carcass traits in domestic pigeons (Columba livia).

    Science.gov (United States)

    Yin, Z Z; Dong, X Y; Dong, D J; Ma, Y Z

    2016-10-01

    Single nucleotide polymorphisms (SNPs) in the exons of the myogenic factor 5 (MYF5) and Kruppel-like factor 15 (KLF15) genes were identified and analysed by using DNA sequencing methods in 60 female domestic pigeons (Columba livia). Five SNPs (T5067A, C5084T, C5101T, T5127A and C5154G) were detected in exon 3 of MYF5 and 6 SNPs (C1398T, C1464T, G1542A, C1929T, G1965A and A2355G) were found in exon 2 of KLF15, respectively. The analysis revealed three genotypes, in which the AA genotype was dominant and the A allele showed a dominant advantage. For the MYF5 gene, the C5084T and T5127A SNP genotypes were significantly associated with carcass traits of pigeons. Within those two SNPs, the BB genotype showed relatively higher trait association values than those of AA or AB genotypes. No significant association was observed between the KLF15 SNP genotypes and carcass traits. These results indicated that the MYF5 gene is a potential major gene affecting carcass traits in domestic pigeons. The BB genotype of the C5084T and T5127A SNPs could be a potential candidate genetic marker for marker-assisted selection in pigeon.

  12. Association of DGAT2 gene polymorphisms with carcass and meat quality traits in domestic pigeons (Columba livia).

    Science.gov (United States)

    Mao, H G; Dong, X Y; Cao, H Y; Xu, N Y; Yin, Z Z

    2018-04-01

    1. Diacylglycerol acyltransferase (DGAT) plays an important role in the synthesis of triacylglycerol, but its effects on meat quality and carcass composition in pigeons are unclear. In this study, single-nucleotide polymorphisms (SNPs) in the exons of the DGAT2 gene were identified and analysed by using DNA sequencing methods in 200 domestic pigeons (Columba livia). The associations between DGAT2 polymorphisms and carcass and meat quality traits were also analysed. 2. Sequencing results showed that 5 nucleotide mutations were detected in exons 3, 4, 5 and 6 of the DGAT2 gene. The analysis revealed three genotypes (AA, AB and BB) in G18398T and G22484C, in which the AA genotype and A allele had the highest frequency. 3. In the SNP of G18398T located in exon 5, individuals with genotype BB had significantly higher meat quality and lower abdominal fat content than those with AA or AB genotype. In the SNP of G22484C located in exon 6, the genotype AA showed highest carcass trait values, while the genotype BB represented better meat quality, compared to AA and AB genotypes. 4. The results imply that DGAT2 gene has a close relationship with carcass and meat quality traits in pigeons, and the SNPs of G18398T and G22484C can be used as genetic markers for marker-assisted breeding in pigeon.

  13. 36 CFR 1005.4 - Commercial passenger-carrying motor vehicles.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Commercial passenger-carrying motor vehicles. 1005.4 Section 1005.4 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.4 Commercial passenger-carrying motor vehicles. Passenger-carrying motor...

  14. Biochemical and ultrastructural analysis of β-VLDL and AC-LDL metabolism by pigeon monocyte-derived macrophages in culture

    International Nuclear Information System (INIS)

    Henson, D.A.

    1987-01-01

    It is proposed that monocyte-derived foam cells in atherosclerotic lesions of White Carneau pigeons become lipid-filled through the uptake of lipoproteins including β-migrating very low density lipoproteins (β-VLDL) and acetylated low density lipoproteins (Ac-LDL). Using iodinated forms of the above lipoproteins, specific and saturable receptors for both β-VLDL and Ac-LDL were detected on the surface of White Carneau pigeon monocyte-derived macrophages in culture. Competition studies demonstrated the high degree of binding specificity for 125 I-Ac-LDL. Likewise, binding of 125 I-β-VLDL to its receptor was significantly inhibited by excess β-VLDL, however LDL from both hyper- and normocholesterolemic pigeons were also recognized by the receptor. Upon binding of β-VLDL and Ac-LDL to their respective receptors, the lipoproteins were rapidly internalized and delivered to intracellular sites of degradation. As measured by the amount of 14 C-oleate incorporated into cholesteryl 14 C-oleate, the cholesterole liberated from the degradation of both β-VLDL and Ac-LDL stimulated cholesteryl ester synthesis in the pigeon cells. Using lipoproteins conjugated to colloidal gold of visualization with transmission electron microscopy, a major difference in the binding and uptake properties of β-VLDL-Gold and Ac-LDL-Gold was documented

  15. Nutrient composition, functional, and pasting properties of unripe cooking banana, pigeon pea, and sweetpotato flour blends.

    Science.gov (United States)

    Ohizua, Ehimen R; Adeola, Abiodun A; Idowu, Micheal A; Sobukola, Olajide P; Afolabi, T Adeniyi; Ishola, Raphael O; Ayansina, Simeon O; Oyekale, Tolulope O; Falomo, Ayorinde

    2017-05-01

    This study investigated some quality attributes of unripe cooking banana (UBF), pigeon pea (PPF), and sweetpotato (SPF) flour blends. Simplex centroid mixture design was used to obtain 17 blends from the flours. The nutrient composition, color, and functional properties of the blends were evaluated using standard methods. Data were subjected to analysis of variance and treatment means were compared using Duncan's multiple range test at 5% probability level. There were significant ( p  pigeon pea-sweetpotato flour blends are desirable for alleviating malnutrition in Nigeria and developing new food formulations.

  16. Intercity passenger rail : the congress faces critical decisions about the role of and funding for intercity passenger rail systems

    Science.gov (United States)

    2001-07-25

    With the growth in the nation's highway and aviation systems in the : previous decades, intercity passenger rail service lost its competitive edge. Highways have enabled cars to be competitive with conventional passenger trains (those operating up to...

  17. Transfer between local and global processing levels by pigeons (Columba livia) and humans (Homo sapiens) in exemplar- and rule-based categorization tasks.

    Science.gov (United States)

    Aust, Ulrike; Braunöder, Elisabeth

    2015-02-01

    The present experiment investigated pigeons' and humans' processing styles-local or global-in an exemplar-based visual categorization task in which category membership of every stimulus had to be learned individually, and in a rule-based task in which category membership was defined by a perceptual rule. Group Intact was trained with the original pictures (providing both intact local and global information), Group Scrambled was trained with scrambled versions of the same pictures (impairing global information), and Group Blurred was trained with blurred versions (impairing local information). Subsequently, all subjects were tested for transfer to the 2 untrained presentation modes. Humans outperformed pigeons regarding learning speed and accuracy as well as transfer performance and showed good learning irrespective of group assignment, whereas the pigeons of Group Blurred needed longer to learn the training tasks than the pigeons of Groups Intact and Scrambled. Also, whereas humans generalized equally well to any novel presentation mode, pigeons' transfer from and to blurred stimuli was impaired. Both species showed faster learning and, for the most part, better transfer in the rule-based than in the exemplar-based task, but there was no evidence of the used processing mode depending on the type of task (exemplar- or rule-based). Whereas pigeons relied on local information throughout, humans did not show a preference for either processing level. Additional tests with grayscale versions of the training stimuli, with versions that were both blurred and scrambled, and with novel instances of the rule-based task confirmed and further extended these findings. PsycINFO Database Record (c) 2015 APA, all rights reserved.

  18. Quality evaluation of cassava-pigeon pea composite flour and the ...

    African Journals Online (AJOL)

    Cassava flour (CF) and pigeon pea flours (PF) were respectively produced and blended in the ratios of 100:0, 95:5, 90:10, 85:15 and 80:20. The flour blends were subjected to proximate, functional and anti-nutrient analysis after which they were used to produce cookies. The sensory and physical characteristics were ...

  19. Biological extinction in earth history

    Science.gov (United States)

    Raup, D. M.

    1986-01-01

    Virtually all plant and animal species that have ever lived on the earth are extinct. For this reason alone, extinction must play an important role in the evolution of life. The five largest mass extinctions of the past 600 million years are of greatest interest, but there is also a spectrum of smaller events, many of which indicate biological systems in profound stress. Extinction may be episodic at all scales, with relatively long periods of stability alternating with short-lived extinction events. Most extinction episodes are biologically selective, and further analysis of the victims and survivors offers the greatest chance of deducing the proximal causes of extinction. A drop in sea level and climatic change are most frequently invoked to explain mass extinctions, but new theories of collisions with extraterrestrial bodies are gaining favor. Extinction may be constructive in a Darwinian sense or it may only perturb the system by eliminating those organisms that happen to be susceptible to geologically rare stresses.

  20. Biological Extinction in Earth History

    Science.gov (United States)

    Raup, David M.

    1986-03-01

    Virtually all plant and animal species that have ever lived on the earth are extinct. For this reason alone, extinction must play an important role in the evolution of life. The five largest mass extinctions of the past 600 million years are of greatest interest, but there is also a spectrum of smaller events, many of which indicate biological systems in profound stress. Extinction may be episodic at all scales, with relatively long periods of stability alternating with short-lived extinction events. Most extinction episodes are biologically selective, and further analysis of the victims and survivors offers the greatest chance of deducing the proximal causes of extinction. A drop in sea level and climatic change are most frequently invoked to explain mass extinctions, but new theories of collisions with extraterrestrial bodies are gaining favor. Extinction may be constructive in a Darwinian sense or it may only perturb the system by eliminating those organisms that happen to be susceptible to geologically rare stresses.

  1. Metapopulation extinction risk: dispersal's duplicity.

    Science.gov (United States)

    Higgins, Kevin

    2009-09-01

    Metapopulation extinction risk is the probability that all local populations are simultaneously extinct during a fixed time frame. Dispersal may reduce a metapopulation's extinction risk by raising its average per-capita growth rate. By contrast, dispersal may raise a metapopulation's extinction risk by reducing its average population density. Which effect prevails is controlled by habitat fragmentation. Dispersal in mildly fragmented habitat reduces a metapopulation's extinction risk by raising its average per-capita growth rate without causing any appreciable drop in its average population density. By contrast, dispersal in severely fragmented habitat raises a metapopulation's extinction risk because the rise in its average per-capita growth rate is more than offset by the decline in its average population density. The metapopulation model used here shows several other interesting phenomena. Dispersal in sufficiently fragmented habitat reduces a metapopulation's extinction risk to that of a constant environment. Dispersal between habitat fragments reduces a metapopulation's extinction risk insofar as local environments are asynchronous. Grouped dispersal raises the effective habitat fragmentation level. Dispersal search barriers raise metapopulation extinction risk. Nonuniform dispersal may reduce the effective fraction of suitable habitat fragments below the extinction threshold. Nonuniform dispersal may make demographic stochasticity a more potent metapopulation extinction force than environmental stochasticity.

  2. 46 CFR 71.75-5 - Passenger Ship Safety Certificate.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Passenger Ship Safety Certificate. 71.75-5 Section 71.75-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS INSPECTION AND... Passenger Ship Safety Certificate. (a) All vessels on an international voyage are required to have a...

  3. Temporal and contextual consistency of leadership in homing pigeon flocks.

    Directory of Open Access Journals (Sweden)

    Carlos D Santos

    Full Text Available Organized flight of homing pigeons (Columba livia was previously shown to rely on simple leadership rules between flock mates, yet the stability of this social structuring over time and across different contexts remains unclear. We quantified the repeatability of leadership-based flock structures within a flight and across multiple flights conducted with the same animals. We compared two contexts of flock composition: flocks of birds of the same age and flight experience; and, flocks of birds of different ages and flight experience. All flocks displayed consistent leadership-based structures over time, showing that individuals have stable roles in the navigational decisions of the flock. However, flocks of balanced age and flight experience exhibited reduced leadership stability, indicating that these factors promote flock structuring. Our study empirically demonstrates that leadership and followership are consistent behaviours in homing pigeon flocks, but such consistency is affected by the heterogeneity of individual flight experiences and/or age. Similar evidence from other species suggests leadership as an important mechanism for coordinated motion in small groups of animals with strong social bonds.

  4. Autophagy response in the liver of pigeon exposed to avermectin.

    Science.gov (United States)

    Wang, Xian-Song; Liu, Ci; Khoso, Pervez Ahmed; Zheng, Weijia; Li, Ming; Li, Shu

    2017-05-01

    Pesticide residues are an important aspect of environmental pollution. Environmental avermectin residues have produced adverse effects in organisms. Many pesticides exert their toxic effects via the mechanism of autophagy. The purpose of this study was to examine the changes in autophagy levels and in autophagy-related genes, including LC3, Beclin 1, Dynein, ATG5, TORC1, and TORC2, resulting from exposure to subchronic levels of AVM in liver tissue in the king pigeon model. We observed abundant autophagic vacuoles with extensively degraded organelles, autophagosomal vacuoles, secondary lysosomes, and double-membrane structures in the liver. The expression levels of the autophagy-related genes LC3-I, LC3-II, Beclin 1, ATG5, and Dynein were up-regulated; however, TORC1 and TORC2 expression levels were down-regulated. These changes occurred in a concentration-dependent manner after AVM exposure for 30, 60, and 90 days in pigeons. Taken together, these results suggested that AVM increased the autophagic flux and that upregulation of autophagy might be closely related to the hepatotoxicity of AVM in birds.

  5. Accounting for negative automaintenance in pigeons: a dual learning systems approach and factored representations.

    Directory of Open Access Journals (Sweden)

    Florian Lesaint

    Full Text Available Animals, including Humans, are prone to develop persistent maladaptive and suboptimal behaviours. Some of these behaviours have been suggested to arise from interactions between brain systems of Pavlovian conditioning, the acquisition of responses to initially neutral stimuli previously paired with rewards, and instrumental conditioning, the acquisition of active behaviours leading to rewards. However the mechanics of these systems and their interactions are still unclear. While extensively studied independently, few models have been developed to account for these interactions. On some experiment, pigeons have been observed to display a maladaptive behaviour that some suggest to involve conflicts between Pavlovian and instrumental conditioning. In a procedure referred as negative automaintenance, a key light is paired with the subsequent delivery of food, however any peck towards the key light results in the omission of the reward. Studies showed that in such procedure some pigeons persisted in pecking to a substantial level despite its negative consequence, while others learned to refrain from pecking and maximized their cumulative rewards. Furthermore, the pigeons that were unable to refrain from pecking could nevertheless shift their pecks towards a harmless alternative key light. We confronted a computational model that combines dual-learning systems and factored representations, recently developed to account for sign-tracking and goal-tracking behaviours in rats, to these negative automaintenance experimental data. We show that it can explain the variability of the observed behaviours and the capacity of alternative key lights to distract pigeons from their detrimental behaviours. These results confirm the proposed model as an interesting tool to reproduce experiments that could involve interactions between Pavlovian and instrumental conditioning. The model allows us to draw predictions that may be experimentally verified, which could help

  6. Molecular cloning, characterization, and expression analysis of fatty acid translocase (FAT/CD36) in the pigeon (Columba livia domestica).

    Science.gov (United States)

    Xie, P; Zhang, A T; Wang, C; Azzam, M M M; Zou, X T

    2012-07-01

    Fatty acid translocase (FAT/CD36) is a transmembrane glycoprotein that plays an important role in transporting long-chain fatty acids. In the current study, a full-length cDNA of FAT/CD36 was first cloned from the intestine of White King pigeon by rapid amplification of cDNA ends (RACE) method. The full-length cDNA of pigeon FAT/CD36 was 2,282 bp, including a 5'-untranslated region of 224 bp, a 3'-untranslated region of 642 bp, and an open reading frame of 1,416 bp encoding a protein of 471 amino acids with the predicted molecular weight of 52.7 kDa. Sequence comparison indicated that FAT/CD36 of pigeon had high identity with other avian FAT/CD36. Using quantitative real-time PCR, expression of FAT/CD36 was the greatest in the duodenum at 28 d posthatch, and in the jejunum, the expression of FAT/CD36 at 14 d posthatch was greater than at 8 d but the same as 28 d posthatch. However, in the ileum, expression of FAT/CD36 peaked at embryonic d 15 and 8 d posthatch. The effects of long-chain fatty acids on pigeon FAT/CD36 and peroxisome proliferator activated receptor γ (PPARγ) mRNA expression were also investigated in vitro. It showed that a low concentration (5 μM) of oleic acid, palmitic acid, and linoleic acid can significantly increase FAT/CD36 and PPARγ mRNA level in pigeon jejunum. However, for linolenic acid or arachidonic acid, the induction of both gene expressions needed a higher concentration (50 μM or 250 μM). Two hundred and 50 μM palmitic acid was shown to suppress FAT/CD36 gene expression. The results suggest that FAT/CD36 may be a representative of intestine development in pigeon, and it could be regulated by long-chain fatty acids via PPARγ pathway.

  7. Stress before extinction learning enhances and generalizes extinction memory in a predictive learning task.

    Science.gov (United States)

    Meir Drexler, Shira; Hamacher-Dang, Tanja C; Wolf, Oliver T

    2017-05-01

    In extinction learning, the individual learns that a previously acquired association (e.g. between a threat and its predictor) is no longer valid. This learning is the principle underlying many cognitive-behavioral psychotherapeutic treatments, e.g. 'exposure therapy'. However, extinction is often highly-context dependent, leading to renewal (relapse of extinguished conditioned response following context change). We have previously shown that post-extinction stress leads to a more context-dependent extinction memory in a predictive learning task. Yet as stress prior to learning can impair the integration of contextual cues, here we aim to create a more generalized extinction memory by inducing stress prior to extinction. Forty-nine men and women learned the associations between stimuli and outcomes in a predictive learning task (day 1), extinguished them shortly after an exposure to a stress/control condition (day 2), and were tested for renewal (day 3). No group differences were seen in acquisition and extinction learning, and a renewal effect was present in both groups. However, the groups differed in the strength and context-dependency of the extinction memory. Compared to the control group, the stress group showed an overall reduced recovery of responding to the extinguished stimuli, in particular in the acquisition context. These results, together with our previous findings, demonstrate that the effects of stress exposure on extinction memory depend on its timing. While post-extinction stress makes the memory more context-bound, pre-extinction stress strengthens its consolidation for the acquisition context as well, making it potentially more resistant to relapse. These results have implications for the use of glucocorticoids as extinction-enhancers in exposure therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Environmental Performance Evaluation of Ro-Ro Passenger Ferry Transportation

    DEFF Research Database (Denmark)

    Kristensen, Hans Otto Holmegaard; Hagemeister, Constantin

    2012-01-01

    /or emissions per transport unit, is related to the same unit for the different transport forms. For Ro-Ro passenger ferries it can be difficult to find a suitable common transport unit, as they often transport a mix of cargo, such as passengers, passenger cars, trucks, lorries, busses and other rolling...

  9. Mortality of German travellers on passenger vessels.

    Science.gov (United States)

    Oldenburg, Marcus; Herzog, Jan; Püschel, Klaus; Harth, Volker

    2016-01-01

    In the past two decades, more and more Germans decided to spend their holidays on a passenger vessel. This study examined the frequencies and causes of deaths of German travellers aboard passenger vessels of all flags. The shipboard deaths of all German travellers within the time period from 1998 to 2008 were counted using the German civil central register in Berlin. The available documentation in this register provides information on frequencies, circumstances and causes of deaths on ships. In the above-mentioned period of time, the total cohort of German travellers on cruise ships is estimated to be 5.97 million persons. During the 11-year examination period, 135 shipboard deaths of German passengers [102 males (75.6%) and 33 females (24.4%)] were recorded. Out of these travellers, 110 died on cruise ships. When considering only the passengers on cruise ships (without those on ferries) an average crude mortality rate of 1.8 per 100,000 German passengers was calculated. The crude mortality rate of shipboard death for males and females was 2.5 and 0.8 per 100,000 German passengers with a mean age of 71.2 years [standard deviation (SD) 16.0 years] and 73.3 years (SD 16.0 years), respectively. Significantly, more deceased travellers older than 70 years were observed on traditional cruise ships and resort vessels than on passenger ferries (P = 0.001). The causes of death were documented in 85 cases (63.0%). Out of these documented deaths, 82 (96.5%) cases were regarded to be natural causes (particularly circulatory diseases) and 3 (3.5%) as unnatural causes (twice drowning and once an accidental fall). In spite of the large proportion of unknown causes of death, this study argues for a high significance of internal causes of deaths among German passengers. Thus, ship's doctors-particularly those on traditional cruise ships-should be well experienced in internal and geriatric medicines. © The Author 2016. Published by Oxford University Press on behalf of

  10. Real-time passenger counting by active linear cameras

    Science.gov (United States)

    Khoudour, Louahdi; Duvieubourg, Luc; Deparis, Jean-Pierre

    1996-03-01

    The companies operating subways are very much concerned with counting the passengers traveling through their transport systems. One of the most widely used systems for counting passengers consists of a mechanical gate equipped with a counter. However, such simple systems are not able to count passengers jumping above the gates. Moreover, passengers carrying large luggage or bags may meet some difficulties when going through such gates. The ideal solution is a contact-free counting system that would bring more comfort of use for the passengers. For these reasons, we propose to use a video processing system instead of these mechanical gates. The optical sensors discussed in this paper offer several advantages including well defined detection areas, fast response time and reliable counting capability. A new technology has been developed and tested, based on linear cameras. Preliminary results show that this system is very efficient when the passengers crossing the optical gate are well separated. In other cases, such as in compact crowd conditions, reasonable accuracy has been demonstrated. These results are illustrated by means of a number of sequences shot in field conditions. It is our belief that more precise measurements could be achieved, in the case of compact crowd, by other algorithms and acquisition techniques of the line images that we are presently developing.

  11. Temporal factors in the extinction of fear in inbred mouse strains differing in extinction efficacy.

    Science.gov (United States)

    MacPherson, Kathryn; Whittle, Nigel; Camp, Marguerite; Gunduz-Cinar, Ozge; Singewald, Nicolas; Holmes, Andrew

    2013-07-05

    Various neuropsychiatric conditions, including posttraumatic stress disorder (PTSD), are characterized by deficient fear extinction, but individuals differ greatly in risk for these. While there is growing evidence that fear extinction is influenced by certain procedural variables, it is unclear how these influences might vary across individuals and subpopulations. To model individual differences in fear extinction, prior studies identified a strain of inbred mouse, 129S1/SvImJ (S1), which exhibits a profound deficit in fear extinction, as compared to other inbred strains, such as C57BL/6J (B6). Here, we assessed the effects of procedural variables on the impaired extinction phenotype of the S1 strain and, by comparison, the extinction-intact B6 strain. The variables studied were 1) the interval between conditioning and extinction, 2) the interval between cues during extinction training, 3) single-cue exposure before extinction training, and 4) extinction of a second-order conditioned cue. Conducting extinction training soon after ('immediately') conditioning attenuated fear retrieval in S1 mice and impaired extinction in B6 mice. Spacing cue presentations with long inter-trial intervals during extinction training augmented fear in S1 and B6 mice. The effect of spacing was lost with one-trial fear conditioning in B6, but not S1 mice. A single exposure to a conditioned cue before extinction training did not alter extinction retrieval, either in B6 or S1 mice. Both the S1 and B6 strains exhibited robust second-order fear conditioning, in which a cue associated with footshock was sufficient to serve as a conditioned exciter to condition a fear association to a second cue. B6 mice extinguished the fear response to the second-order conditioned cue, but S1 mice failed to do so. These data provide further evidence that fear extinction is strongly influenced by multiple procedural variables and is so in a highly strain-dependent manner. This suggests that the efficacy of

  12. Prevalence and risk factors for Campylobacter spp., Salmonella spp., Coxiella burnetii, and Newcastle disease virus in feral pigeons (Columba livia) in public areas of Montreal, Canada

    Science.gov (United States)

    Gabriele-Rivet, Vanessa; Fairbrother, Julie-Hélène; Tremblay, Donald; Harel, Josée; Côté, Nathalie; Arsenault, Julie

    2016-01-01

    Feral pigeons (Columbia livia) can harbor a range of zoonotic pathogens. A transversal study was undertaken to estimate the prevalence of feral pigeons infected by various pathogens in public areas in Montreal, Quebec. Cloacal swabs from captured birds were cultured for Salmonella spp. and Campylobacter spp. and tested by real-time polymerase chain reaction (RT-PCR) for the detection of Coxiella burnetii. An oropharyngeal swab was also submitted to real-time reverse-transcription polymerase chain reaction (RRT-PCR) for the detection of Newcastle disease virus. Among the 187 pigeons tested from 10 public areas, 9.1% (95% CI: 3.0 to 15.2) were positive for Campylobacter spp. with all strains identified as Campylobacter jejuni. The Campylobacter status of birds was not associated with individual characteristics of birds, with the exception of body score. None of the pigeons tested positive for the other pathogens. Direct or indirect contacts with feral pigeons may constitute a potential risk for Campylobacter infection in humans. PMID:26733736

  13. 14 CFR 135.113 - Passenger occupancy of pilot seat.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Passenger occupancy of pilot seat. 135.113... Operations § 135.113 Passenger occupancy of pilot seat. No certificate holder may operate an aircraft type certificated after October 15, 1971, that has a passenger seating configuration, excluding any pilot seat, of...

  14. Survey of Shiga toxin-producing Escherichia coli O157:H7 in urban pigeons (Columba livia in the city of Napoli, Italy

    Directory of Open Access Journals (Sweden)

    Alessandro Fioretti

    2010-01-01

    Full Text Available Recently, several studies have demonstrated that pigeon is an important reservoir of Shiga toxin-producing E. coli O157:H7. The aim of this study was to evaluate the presence of this pathogen in urban pigeons in the city of Napoli. The sampling was carried out during the period November 2005/July 2006. The city was subdivided in 56 quadrants by Geographical Information System. Each quadrant was analysed three times. From each quadrant, 3 pigeons were analysed by cloacal swabs. A total of 504 cloacal swabs was obtained. We isolated four E. coli O157:H7 strains. By multiplex PCR, all strains carried eae and stx2 genes, whereas only one strain carried the stx1 gene. 2/4 isolated strains carried hly gene which is considered a hallmark of human pathogenic strains. Our results indicate that pigeon faces are a source of E. coli O157:H7 for birds, mammals and humans.

  15. Principles of Logistics Applied to Railway Passenger Transport

    Directory of Open Access Journals (Sweden)

    Vojtek Martin

    2017-01-01

    Full Text Available Main challenge of logistics is delivering right assortment of products in exact amount, to exact place, in exact time, ecologically and for exact price. Logistics deals with freight transport but when the word ‘products’ is changed to ‘passengers’, then many principles can be applied to passenger transport. Railway passenger transport is the key part of passenger transport system, so it is necessary to optimize it on logistics philosophy at first.

  16. Antitrichomonal activity of Peganum harmala alkaloid extract against trichomoniasis in pigeon (Columba livia domestica).

    Science.gov (United States)

    Tabari, M A; Youssefi, M R; Moghadamnia, A A

    2017-06-01

    1. This study was designed to evaluate the antitrichomonal effects of P. harmala alkaloid extract against T. gallinae, both in vitro and in vivo, as well as comparing it to that of metronidazole, conventional antitrichomonal medication and harmine and harmaline, the two alkaloids present in P. harmala. 2. T. gallinae were collected by the wet mount method from infected free-living pigeons. The in vitro assay was performed using multi-well plates containing test compounds in final concentrations of 5, 10, 15, 20, 30, 50 or 100 μg/ml. The in vivo assay was done on 60 experimentally infected pigeons dosed with metronidazole at 50 mg/kg body weight (BW) or alkaloids at 25 mg/kg BW. 3. The 24 h minimum inhibitory concentration (MIC) of alkaloid extract was 15 µg/ml while that of metronidazole was 50 µg/ml. Harmine and harmaline revealed 24 h MIC of 30 and 100 µg/ml, respectively. Treatment of infected pigeons with alkaloids led to a full recovery after 3 d but with metronidazole total eradication of trophozoites was not achieved. 4. In conclusion, data of the present study suggested P. harmala is a potent natural anti-trichomonal agent, effective against T. gallinae.

  17. The effects of nidopallium caudolaterale inactivation on serial-order behaviour in pigeons (Columba livia).

    Science.gov (United States)

    Johnston, Melissa Jane; Clarkson, Andrew N; Gowing, Emma K; Scarf, Damian; Colombo, Mike

    2018-06-06

    Serial-order behaviour is the ability to complete a sequence of responses in a predetermined order to achieve a reward. In birds, serial-order behaviour is thought to be impaired by damage to the nidopallium caudolaterale (NCL). In the current study, we examined the role of the NCL in serial-order behaviour by training pigeons on a 4-item serial-order task and a go/no-go discrimination task. Following training, pigeons were received infusions of 1μl of either tetrodotoxin (TTX) or saline. Saline infusions had no impact on serial-order behaviour whereas TTX infusions resulted in a significant decrease in performance. The serial-order impairments, however, were not the results of errors of any specific error at any specific list item. With respect to the go/no-go discrimination task, saline infusions also had no impact on performance whereas TTX infusions impaired pigeons' discrimination abilities. Given the impairments on the go/no-go discrimination task, which does not require processing of serial-order information, we tentatively conclude that damage to the NCL does not impair serial-order behaviour per se, but rather results in a more generalised impairment that may impact performance across a range of tasks.

  18. Extinction produces context inhibition and multiple-context extinction reduces response recovery in human predictive learning.

    Science.gov (United States)

    Glautier, Steven; Elgueta, Tito; Nelson, James Byron

    2013-12-01

    Two experiments with human participants were used to investigate recovery of an extinguished learned response after a context change using ABC designs. In an ABC design, the context changes over the three successive stages of acquisition (context A), extinction (context B), and test (context C). In both experiments, we found reduced recovery in groups that had extinction in multiple contexts, and that the extinction contexts acquired inhibitory strength. These results confirm those of previous investigations, that multiple-context extinction can produce less response recovery than single-context extinction, and they also provide new evidence for the involvement of contextual inhibitory processes in extinction in humans. The foregoing results are broadly in line with a protection-from-extinction account of response recovery. Yet, despite the fact that we detected contextual inhibition, predictions based on protection-from-extinction were not fully reliable for the single- and multiple-context group differences that we observed in (1) rates of extinction and (2) the strength of context inhibition. Thus, although evidence was obtained for a protection-from-extinction account of response recovery, this account can not explain all of the data.

  19. A train dispatching model based on fuzzy passenger demand forecasting during holidays

    Directory of Open Access Journals (Sweden)

    Fei Dou Dou

    2013-03-01

    Full Text Available Abstract: Purpose: The train dispatching is a crucial issue in the train operation adjustment when passenger flow outbursts. During holidays, the train dispatching is to meet passenger demand to the greatest extent, and ensure safety, speediness and punctuality of the train operation. In this paper, a fuzzy passenger demand forecasting model is put up, then a train dispatching optimization model is established based on passenger demand so as to evacuate stranded passengers effectively during holidays. Design/methodology/approach: First, the complex features and regularity of passenger flow during holidays are analyzed, and then a fuzzy passenger demand forecasting model is put forward based on the fuzzy set theory and time series theory. Next, the bi-objective of the train dispatching optimization model is to minimize the total operation cost of the train dispatching and unserved passenger volume during holidays. Finally, the validity of this model is illustrated with a case concerned with the Beijing-Shanghai high-speed railway in China. Findings: The case study shows that the fuzzy passenger demand forecasting model can predict outcomes more precisely than ARIMA model. Thus train dispatching optimization plan proves that a small number of trains are able to serve unserved passengers reasonably and effectively. Originality/value: On the basis of the passenger demand predictive values, the train dispatching optimization model is established, which enables train dispatching to meet passenger demand in condition that passenger flow outbursts, so as to maximize passenger demand by offering the optimal operation plan.

  20. Seasonal Changes in Atmospheric Noise Levels and the Annual Variation in Pigeon Homing Performance

    Science.gov (United States)

    Hagstrum, J. T.; McIsaac, H. P.; Drob, D. P.

    2015-12-01

    The remarkable navigational ability of homing pigeons (Columba livia) is influenced by a number of factors, an unknown one of which causes the "Wintereffekt"1 or annual variation in homing performance. Minima in homeward orientation and return speeds have been observed in winter, with maxima in summer, during repetitive pigeon releases from single sites near experimental lofts in Wilhelmshaven, Göttingen, and Munich, Germany, and near Pisa, Italy1-4. Overall the annual variation is more pronounced in northern Germany than Italy4, and both mature and juvenile cohorts respond to this seasonal factor. Older, more experienced pigeons are better at compensating for its effects than naïve ones, but are still affected after numerous releases. The narrow low-frequency band of atmospheric background noise (microbaroms; 0.1-0.3 Hz) also varies with an annual cycle that generally has higher amplitudes in winter than in summer depending on location5. In addition, homing pigeons, and possibly other birds, apparently use infrasonic signals of similar frequency as navigational cues6, and a seasonal variation in background noise levels could cause corresponding changes in signal-to-noise ratios and thus in homing performance. The annual variation in homing performance, however, was not observed during long-term pigeon releases at two sites in eastern North America. The annual and geographic variability in homing performance in the northern hemisphere can be explained to a first order by seasonal changes in infrasonic noise sources related to ocean storm activity, and to the direction and intensity of stratospheric winds. In addition, increased dispersion in departure bearings of individual birds for some North American releases were likely caused by additional infrasonic noise associated with severe weather events during tornado and Atlantic hurricane seasons. 1Kramer, G. & von Saint Paul, U., J. Ornithol. 97, 353-370 (1956); 2Wallraff, H. G., Z. Tierpsychol. 17, 82-113 (1960

  1. Modern examples of extinctions

    DEFF Research Database (Denmark)

    Lövei, Gabor L

    2013-01-01

    No species lives forever, and extinction is the ultimate fate of all living species. The fossil record indicates that a recent extinction wave affecting terrestrial vertebrates was parallel with the arrival of modern humans to areas formerly uninhabited by them. These modern instances of extinction...

  2. Plasma uric acid, creatinine, and urea nitrogen concentrations after whole blood administration via the gastrointestinal tract in domestic pigeons (Columba livia).

    Science.gov (United States)

    Sheldon, Julie; Hoover, John P; Payton, Mark E

    2007-06-01

    To determine if blood administered to pigeons by gavage tube would simulate gastrointestinal hemorrhage in a noncarnivorous avian model, be digested in the gastrointestinal tract, and subsequently alter concentrations of plasma urea nitrogen, creatinine, or uric acid, blood from common peacocks (Pavo cristatus) was administered by gavage tube to 5 healthy domestic pigeons (Columba livia) at doses of 0.5, 1.0, 2.0, 4.0, and 8.0 ml/kg. No significant difference in plasma concentrations of urea nitrogen, creatinine, or uric acid was seen 4-6 hours after gavage. The findings did not support or rule out the presence of gastrointestinal blood in pigeons as a model for hemorrhage in noncarnivorous avian species.

  3. Delay Management with Re-Routing of Passengers

    NARCIS (Netherlands)

    T.A.B. Dollevoet (Twan); D. Huisman (Dennis); M.E. Schmidt (Marie); A. Schöbel (Anita)

    2010-01-01

    textabstractThe question of delay management is whether trains should wait for a delayed feeder train or should depart on time. In classical delay management models passengers always take their originally planned route. In this paper, we propose a model where re-routing of passengers is

  4. Salmonella outbreak among railway and airline passengers.

    Science.gov (United States)

    Hatakka, M

    1992-01-01

    A widespread outbreak by Salmonella infantis, infecting a total of 226 people, occurred in Finland at the beginning of August 1986. Of those infected, 107 were railway passengers, 91 were airline passengers and 28 were employed in a food processing establishment. The outbreak among the railway passengers was caused by egg sandwiches, the airline passengers were infected by a meal served on board and the catering employees by the breakfast served in the establishment. The outbreak was caused by food prepared in the establishment's kitchen. The employees' breakfasts had probably been contaminated by an employee who was a symptom-free Salmonella infantis carrier, and a number of the employees subsequently became infected, leading to widespread contamination of the food prepared in the establishment. The spread of the outbreak was further influenced by a heatwave at the time and by shortcomings in the cold storage facilities. The kitchen's hygiene supervision and the quality control of its output were reorganized after the outbreak.

  5. Study of LH2 fueled subsonic passenger transport aircraft

    Science.gov (United States)

    Brewer, G. D.; Morris, R. E.

    1976-01-01

    The potential of using liquid hydrogen as fuel in subsonic transport aircraft was investigated to explore an expanded matrix of passenger aircraft sizes. Aircraft capable of carrying 130 passengers 2,780 km (1500 n.mi.); 200 passengers 5,560 km (3000 n.mi.); and 400 passengers on a 9,265 km (5000 n.mi.) radius mission, were designed parametrically. Both liquid hydrogen and conventionally fueled versions were generated for each payload/range in order that comparisons could be made. Aircraft in each mission category were compared on the basis of weight, size, cost, energy utilization, and noise.

  6. Detection of magnetic field intensity gradient by homing pigeons (Columba livia in a novel "virtual magnetic map" conditioning paradigm.

    Directory of Open Access Journals (Sweden)

    Cordula V Mora

    Full Text Available It has long been thought that birds may use the Earth's magnetic field not only as a compass for direction finding, but that it could also provide spatial information for position determination analogous to a map during navigation. Since magnetic field intensity varies systematically with latitude and theoretically could also provide longitudinal information during position determination, birds using a magnetic map should be able to discriminate magnetic field intensity cues in the laboratory. Here we demonstrate a novel behavioural paradigm requiring homing pigeons to identify the direction of a magnetic field intensity gradient in a "virtual magnetic map" during a spatial conditioning task. Not only were the pigeons able to detect the direction of the intensity gradient, but they were even able to discriminate upward versus downward movement on the gradient by differentiating between increasing and decreasing intensity values. Furthermore, the pigeons typically spent more than half of the 15 second sampling period in front of the feeder associated with the rewarded gradient direction indicating that they required only several seconds to make the correct choice. Our results therefore demonstrate for the first time that pigeons not only can detect the presence and absence of magnetic anomalies, as previous studies had shown, but are even able to detect and respond to changes in magnetic field intensity alone, including the directionality of such changes, in the context of spatial orientation within an experimental arena. This opens up the possibility for systematic and detailed studies of how pigeons could use magnetic intensity cues during position determination as well as how intensity is perceived and where it is processed in the brain.

  7. A phantom extinction? New insights into extinction dynamics of the Don-hare Lepus tanaiticus.

    Science.gov (United States)

    Prost, S; Knapp, M; Flemmig, J; Hufthammer, A K; Kosintsev, P; Stiller, M; Hofreiter, M

    2010-09-01

    The Pleistocene to Holocene transition was accompanied by a worldwide extinction event affecting numerous mammalian species. Several species such as the woolly mammoth and the giant deer survived this extinction wave, only to go extinct a few thousand years later during the Holocene. Another example for such a Holocene extinction is the Don-hare, Lepus tanaiticus, which inhabited the Russian plains during the late glacial. After being slowly replaced by the extant mountain hare (Lepus timidus), it eventually went extinct during the middle Holocene. Here, we report the phylogenetic relationship of L. tanaiticus and L. timidus based on a 339-basepair (bp) fragment of the mitochondrial D-loop. Phylogenetic tree- and network reconstructions do not support L. tanaiticus and L. timidus being different species. Rather, we suggest that the two taxa represent different morphotypes of a single species and the extinction of 'L. tanaiticus' represents the disappearance of a local morphotype rather than the extinction of a species.

  8. Global population collapse in a superabundant migratory bird and illegal trapping in China.

    Science.gov (United States)

    Kamp, Johannes; Oppel, Steffen; Ananin, Alexandr A; Durnev, Yurii A; Gashev, Sergey N; Hölzel, Norbert; Mishchenko, Alexandr L; Pessa, Jorma; Smirenski, Sergey M; Strelnikov, Evgenii G; Timonen, Sami; Wolanska, Kolja; Chan, Simba

    2015-12-01

    Persecution and overexploitation by humans are major causes of species extinctions. Rare species, often confined to small geographic ranges, are usually at highest risk, whereas extinctions of superabundant species with very large ranges are rare. The Yellow-breasted Bunting (Emberiza aureola) used to be one of the most abundant songbirds of the Palearctic, with a very large breeding range stretching from Scandinavia to the Russian Far East. Anecdotal information about rapid population declines across the range caused concern about unsustainable trapping along the species' migration routes. We conducted a literature review and used long-term monitoring data from across the species' range to model population trend and geographical patterns of extinction. The population declined by 84.3-94.7% between 1980 and 2013, and the species' range contracted by 5000 km. Quantitative evidence from police raids suggested rampant illegal trapping of the species along its East Asian flyway in China. A population model simulating an initial harvest level of 2% of the population, and an annual increase of 0.2% during the monitoring period produced a population trajectory that matched the observed decline. We suggest that trapping strongly contributed to the decline because the consumption of Yellow-breasted Bunting and other songbirds has increased as a result of economic growth and prosperity in East Asia. The magnitude and speed of the decline is unprecedented among birds with a comparable range size, with the exception of the Passenger Pigeon (Ectopistes migratorius), which went extinct in 1914 due to industrial-scale hunting. Our results demonstrate the urgent need for an improved monitoring of common and widespread species' populations, and consumption levels throughout East Asia. © 2015 Society for Conservation Biology.

  9. Differential toxic effects of Carbofuran and Diazinon on time of flight in pigeons (Columba livia): Potential for pesticide effects on migration

    International Nuclear Information System (INIS)

    Brasel, Jeffrey M.; Collier, Abby C.; Pritsos, Chris A.

    2007-01-01

    Cholinesterase inhibiting compounds such as carbamates and organophosphate insecticides have been widely used in agriculture since the ban on organochlorines in the 1970s. Carbofuran, a carbamate, and diazinon, an organophosphate, are among the most commonly implicated cholinesterase inhibitors in episodes of accidental avian toxicity and mortality. Despite the apparent effects of these compounds, little work has been done to study effects of low-level, environmentally relevant doses at the population level in migratory bird species. In this study, homing pigeons were used as surrogate species to assess the differences in the effect of incrementally low doses (0.0, 0.25, 0.5, and 1.0 mg/kg) of carbofuran and diazinon on time of flight and determine whether there was a threshold dose of either or both xenobiotics when orally administered at these levels. The results indicate that there is a significant dose-dependent increase in flight time in pigeons dosed with carbofuran while diazinon exposed pigeons showed little effect. More profound effects were noted with carbofuran with pigeons falling off the pace of the flock and a dose for highly significant increase in flight time elucidated between 0.5 and 1.0 mg/kg. The results of the studies validate the homing pigeon as a good subject for comparative studies of cholinesterase inhibitors in birds and the need for further research on repeated low-level exposures on populations of avian species

  10. 75 FR 16552 - High-Speed Intercity Passenger Rail (HSIPR) Program

    Science.gov (United States)

    2010-04-01

    ...; Enhancing intercity travel options; Ensuring a state of good repair of key intercity passenger rail assets... DEPARTMENT OF TRANSPORTATION Federal Railroad Administration High-Speed Intercity Passenger Rail... selections for the High-Speed Intercity Passenger Rail (HSIPR) Program. This notice builds on the program...

  11. Passengers, Crowding and Complexity : Models for passenger oriented public transport

    NARCIS (Netherlands)

    P.C. Bouman (Paul)

    2017-01-01

    markdownabstractPassengers, Crowding and Complexity was written as part of the Complexity in Public Transport (ComPuTr) project funded by the Netherlands Organisation for Scientific Research (NWO). This thesis studies in three parts how microscopic data can be used in models that have the potential

  12. The Late Ordovician Extinction: How it became the best understood of the five major extinctions.

    Science.gov (United States)

    Sheehan, P.

    2003-04-01

    The end Ordovician extinction has become arguably the best-understood major extinction event in Earth History. A plethora of workers have established the pattern of faunal change and causes of the extinction with remarkably little disagreement. The first indication of increased extinction at the end of the Ordovician was a graph of global diversity patterns by Norman Newell in 1967, although he did not recognize it as a major event. The presence of a major extinction event became clear as William Berry and Art Boucot assembled data for Silurian correlation charts in the late 1960s. The first reports of North African glaciation in the late 1960s provided a cause for the extinction and study of the event snowballed. It was no accident that recognition of the extinction began in North America, because it was there that the extinction completely overturned faunas in the epicontinental seas. Glacio-eustatic regression of shallow seaway coincided with the disappearance of endemic Laurentian faunas and replacement by a highly cosmopolitan fauna in the Silurian. Once the event was established in North America, paleontologists soon found evidence of the event around the globe. The well-documented Hirnantia Fauna was found to correspond to the glacial interval, and Pat Brenchley soon recognized that there were two pulses of extinction, at the beginning and end of the glaciation. At the same time that the faunal changes were being documented geologic studies of the glaciation provided information on the environmental changes associated with the extinction. The timing of the glacial maximum was established in Africa and by the presence of dropstones in high latitude marine rocks. The 1990s saw geochemical techniques employed that allowed examination of atmospheric CO2 and temperature changes. In many places carbonate deposition declined. Glacio-eustatic regression was obvious in many areas, and a sea-level decline in the range of 50-100 m was established. Shallow

  13. Passengers' attitudes and behaviour towards motorcycle helmet use ...

    African Journals Online (AJOL)

    Passengers' attitudes and behaviour towards motorcycle helmet use in Ilorin, ... Remember me ... The purpose of this study was to examine the attitudes, knowledge, and behavior of motorcycle passengers to helmet use in Ilorin metropolis, ...

  14. The seated bus passenger--a review.

    Science.gov (United States)

    Levis, J A

    1978-09-01

    The paper describes the inter-relationship of anthropometry, rig studies and dynamic testing of aspects related to problems of the seated bus passenger. It seeks to draw together sub-sections of a very large study sponsored by the government through the Transport and Road Research Laboratory and undertaken by the Human Factors Group of Leyland Truck and Bus. It is relevant to all those designing passenger carrying transport systems.

  15. Modelling interstellar extinction: Pt. 1

    International Nuclear Information System (INIS)

    Jones, A.P.

    1988-01-01

    Several methods of calculating the extinction of porous silicate grains are discussed, these include effective medium theories and hollow spherical shells. Porous silicate grains are shown to produce enhanced infrared, ultraviolet and far-ultraviolet extinction and this effect can be used to reduce the abundance of carbon required to match the average interstellar extinction, however, matching the visual extinction is rather more problematical. We have shown that the enhanced extinction at long and short wavelengths have different origins, and have explained why the visual extinction is little affected by porosity. The implications of porous grains in the interstellar medium are discussed with particular reference to surface chemistry, the polarization of starlight, and their dynamical evolution. (author)

  16. Manikin families representing obese airline passengers in the US.

    Science.gov (United States)

    Park, Hanjun; Park, Woojin; Kim, Yongkang

    2014-01-01

    Aircraft passenger spaces designed without proper anthropometric analyses can create serious problems for obese passengers, including: possible denial of boarding, excessive body pressures and contact stresses, postural fixity and related health hazards, and increased risks of emergency evacuation failure. In order to help address the obese passenger's accommodation issues, this study developed male and female manikin families that represent obese US airline passengers. Anthropometric data of obese individuals obtained from the CAESAR anthropometric database were analyzed through PCA-based factor analyses. For each gender, a 99% enclosure cuboid was constructed, and a small set of manikins was defined on the basis of each enclosure cuboid. Digital human models (articulated human figures) representing the manikins were created using a human CAD software program. The manikin families were utilized to develop design recommendations for selected aircraft seat dimensions. The manikin families presented in this study would greatly facilitate anthropometrically accommodating large airline passengers.

  17. Changes in hippocampal volume and neuron number co-occur with memory decline in old homing pigeons (Columba livia).

    Science.gov (United States)

    Coppola, Vincent J; Kanyok, Nate; Schreiber, Austin J; Flaim, Mary E; Bingman, Verner P

    2016-05-01

    The mammalian hippocampus is particularly susceptible to age-related structural changes, which have been used to explain, in part, age-related memory decline. These changes are generally characterized by atrophy (e.g., a decrease in volume and number of synaptic contacts). Recent studies have reported age-related spatial memory deficits in older pigeons similar to those seen in older mammals. However, to date, little is known about any co-occurring changes in the aging avian hippocampal formation (HF). In the current study, it was found that the HF of older pigeons was actually larger and contained more neurons than the HF of younger pigeons, a finding that suggests that the pattern of structural changes during aging in the avian HF is different from that seen in the mammalian hippocampus. A working hypothesis for relating the observed structural changes with spatial-cognitive decline is offered. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Delayed matching-to-sample: A tool to assess memory and other cognitive processes in pigeons.

    Science.gov (United States)

    Zentall, Thomas R; Smith, Aaron P

    2016-02-01

    Delayed matching-to-sample is a versatile task that has been used to assess the nature of animal memory. Although once thought to be a relatively passive process, matching research has demonstrated considerable flexibility in how animals actively represent events in memory. But delayed matching can also demonstrate how animals fail to maintain representations in memory when they are cued that they will not be tested (directed forgetting) and how the outcome expected can serve as a choice cue. When pigeons have shown divergent retention functions following training without a delay, it has been taken as evidence of the use of a single-code/default coding strategy but in many cases an alternative account may be involved. Delayed matching has also been used to investigate equivalence learning (how animals represent stimuli when they learn that the same comparison response is correct following the presentation of two different samples) and to test for metamemory (the ability of pigeons to indicate that they understand what they know) by allowing animals to decline to be tested when they are uncertain that they remember a stimulus. How animals assess the passage of time has also been studied using the matching task. And there is evidence that when memory for the sample is impaired by a delay, rather than use the probability of being correct for choice of each of the comparison stimuli, pigeons tend to choose based on the overall sample frequency (base-rate neglect). Finally, matching has been used to identify natural color categories as well as dimensional categories in pigeons. Overall, matching to sample has provided an excellent methodology for assessing an assortment of cognitive processes in animals. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. The Simultaneous Vehicle Scheduling and Passenger Service Problem

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann; Larsen, Allan; Madsen, Oli B.G.

    2013-01-01

    , by modifying the timetable. The planning approach is referred to as the simultaneous vehicle scheduling and passenger service problem (SVSPSP). The SVSPSP is modelled as an integer programming problem and solved using a large neighborhood search metaheuristic. The proposed framework is tested on data inspired......Passengers using public transport systems often experience waiting times when transferring between two scheduled services. In this paper we propose a planning approach that seeks to obtain a favourable trade-off between the two contrasting objectives, passenger service and operating cost...

  20. The Simultaneous Vehicle Scheduling and Passenger Service Problem

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann; Larsen, Allan; Madsen, Oli B.G.

    modifications of the timetable during the vehicle scheduling phase. This planning approach is referred to as the Simultaneous Vehicle Scheduling and Passenger Service Problem (SVSPSP). The SVSPSP is solved using a large neighbourhood search metaheuristic. The proposed framework is tested on data inspired......Passengers using public transport systems often experience waiting times when transferring between two scheduled services. We propose a planning approach which seeks to obtain a favorable trade-off between the conflicting objectives passenger service and operating cost, by allowing some moderate...

  1. Radiation Exposure of Passengers to Cosmic Radiation

    International Nuclear Information System (INIS)

    Salah El-Din, T.; Gomaa, M.A.; Sallah, N.

    2010-01-01

    The main aim of the present study is to review exposure of Egyptian passengers and occupational workers to cosmic radiation during their work. Computed effective dose of passengers by computer code CARI-6 using during either short route, medium route or long route as well as recommended allowed number of flights per year

  2. Econometric Forecasting Models for Air Traffic Passenger of Indonesia

    Directory of Open Access Journals (Sweden)

    Viktor Suryan

    2017-01-01

    Full Text Available One of the major benefits of the air transport services operating in bigger countries is the fact that they provide a vital social economic linkage. This study is an attempt to establish the determinants of the passenger air traffic in Indonesia. The main objective of the study is to determine the economic variables that affect the number of airline passengers using the econometrics model of projection with an emphasis on the use of panel data and to determine the economic variables that affect the number of airline passengers using the econometrics model of projection with an emphasis on the use of time series data. This research also predicts the upcoming number of air traffic passenger until 2030. Air transportation and the economic activity in a country are interdependent. This work first uses the data at the country level and then at the selected airport level for review. The methodology used in this study has adopted the study for both normal regression and panel data regression techniques. Once all these steps are performed, the final equation is taken up for the forecast of the passenger inflow data in the Indonesian airports. To forecast the same, the forecasted numbers of the GDP (Gross Domestic Product and population (independent variables were chosen as a part of the literature review exercise are used. The result of this study shows the GDP per capita have significant related to a number of passengers which the elasticity 2.23 (time-series data and 1.889 for panel data. The exchange rate variable is unrelated to a number of passengers as shown in the value of elasticity. In addition, the total of population gives small value for the elasticity. Moreover, the number of passengers is also affected by the dummy variable (deregulation. With three scenarios: low, medium and high for GDP per capita, the percentage of growth for total number of air traffic passenger from the year 2015 to 2030 is 199.3%, 205.7%, and 320.9% respectively.

  3. Gravity anomalies without geomagnetic disturbances interfere with pigeon homing--a GPS tracking study.

    Science.gov (United States)

    Blaser, Nicole; Guskov, Sergei I; Entin, Vladimir A; Wolfer, David P; Kanevskyi, Valeryi A; Lipp, Hans-Peter

    2014-11-15

    The gravity vector theory postulates that birds determine their position to set a home course by comparing the memorized gravity vector at the home loft with the local gravity vector at the release site, and that they should adjust their flight course to the gravity anomalies encountered. As gravity anomalies are often intermingled with geomagnetic anomalies, we released experienced pigeons from the center of a strong circular gravity anomaly (25 km diameter) not associated with magnetic anomalies and from a geophysical control site, equidistant from the home loft (91 km). After crossing the border zone of the anomaly--expected to be most critical for pigeon navigation--they dispersed significantly more than control birds, except for those having met a gravity anomaly en route. These data increase the credibility of the gravity vector hypothesis. © 2014. Published by The Company of Biologists Ltd.

  4. Divers of Passenger Demand

    OpenAIRE

    Wittmer, Andreas

    2011-01-01

    -Overview drivers of passenger demand -Driver 1: Economic growth in developing countries -Driver 2: International business travel in developed countries -Driver 3: International leisure travel in developed countries

  5. Changes in hepatic glucose and lipid metabolism-related parameters in domestic pigeon (Columba livia) during incubation and chick rearing.

    Science.gov (United States)

    Wan, X P; Xie, P; Bu, Z; Zou, X T

    2018-04-01

    This study aimed to evaluate the hepatic glucose and lipid metabolism-related parameters of adult male and female White King pigeons (Columba livia) during incubation and chick rearing. At day 4 (I4), 10 (I10) and 17 (I17) of incubation and day 1 (R1), 7 (R7), 15 (R15) and 25 (R25) of chick rearing, livers were sampled from six pigeons for each sex. Glycogen and fat contents, activities of glycolytic enzymes (hexokinase, HK; 6-phosphofructokinase, 6-PFK), and genes expressions of key enzymes involved in glycolysis (pyruvate kinase, PK; glucokinase, GK), gluconeogenesis (phosphoenolpyruvate carboxykinase cytosolic, PCK1; fructose-1,6-bisphosphatase, FBP1; glucose-6-phosphatase, G6Pase), fatty acid synthesis (fatty acid synthase, FAS; acetyl-CoA carboxylase, ACC) and fatty acid β-oxidation (carnitine palmitoyltransferase 1, CPT1; acyl-CoA 1, ACO) were measured. In male and female pigeon livers, glycogen content and HK activity dramatically increased after I17 and after R1, respectively; expressions of FBP1 and G6Pase genes were maximized at R15; activity of 6-PFK and expressions of PK and CPT1 genes were highest at R7; fat content and expressions of FAS and ACC genes steeply increased from I10 to R1. In females, hepatic expressions of GK and PCK1 genes were greatest at R7 and I17, respectively; however, in males, both of them were maximized at R15. Hepatic expression of ACO gene was significantly enhanced at R1 compared to I17 and R7 in males, whereas it was notably up-regulated at I17 and R7 in females. Furthermore, expressions of PCK1, GK, FAS and ACC genes were in significant relation to fat content in the livers of female pigeons, while fat content in male pigeons was highly correlated with expression of PCK1, ACC, CPT1 and ACO genes. In conclusion, regulations of glucose and lipid metabolic processes were enhanced in parent pigeon livers from terminal phases of incubation to mid phase of chick rearing with sexual effects. © 2017 Blackwell Verlag GmbH.

  6. Isolation and characteristics of Shiga toxin 2f-producing Escherichia coli among pigeons in Kyushu, Japan.

    Directory of Open Access Journals (Sweden)

    Koichi Murakami

    Full Text Available An increasing number of Shiga toxin 2f-producing Escherichia coli (STEC2f infections in humans are being reported in Europe, and pigeons have been suggested as a reservoir for the pathogen. In Japan, there is very little information regarding carriage of STEC2f by pigeons, prompting the need for further investigation. We collected 549 samples of pigeon droppings from 14 locations in Kyushu, Japan, to isolate STEC2f and to investigate characteristics of the isolates. Shiga toxin stx 2f gene fragments were detected by PCR in 16 (2.9% of the 549 dropping samples across four of the 14 locations. We obtained 23 STEC2f-isolates from seven of the original samples and from three pigeon dropping samples collected in an additional sampling experiment (from a total of seven locations across both sampling periods. Genotypic and phenotypic characteristics were then examined for selected isolates from each of 10 samples with pulsed-field gel electrophoresis profiles. Eight of the stx 2f gene fragments sequenced in this study were homologous to others that were identified in Europe. Some isolates also contained virulence-related genes, including lpfA O26, irp 2, and fyuA, and all of the 10 selected isolates maintained the eae, astA, and cdt genes. Moreover, five of the 10 selected isolates contained sfpA, a gene that is restricted to Shiga toxin-producing E. coli O165:H2 and sorbitol-fermenting Shiga toxin-producing E. coli O157:NM. We document serotypes O152:HNM, O128:HNM, and O145:H34 as STEC2f, which agrees with previous studies on pigeons and humans. Interestingly, O119:H21 was newly described as STEC2f. O145:H34, with sequence type 722, was described in a German study in humans and was also isolated in the current study. These results revealed that Japanese zoonotic STEC2f strains harboring several virulence-related factors may be of the same clonal complexes as some European strains. These findings provide useful information for public health

  7. Analysis of Pigeon (Columba) Ovary Transcriptomes to Identify Genes Involved in Blue Light Regulation

    Science.gov (United States)

    Wang, Ying; Ding, Jia-tong; Yang, Hai-ming; Yan, Zheng-jie; Cao, Wei; Li, Yang-bai

    2015-01-01

    Monochromatic light is widely applied to promote poultry reproductive performance, yet little is currently known regarding the mechanism by which light wavelengths affect pigeon reproduction. Recently, high-throughput sequencing technologies have been used to provide genomic information for solving this problem. In this study, we employed Illumina Hiseq 2000 to identify differentially expressed genes in ovary tissue from pigeons under blue and white light conditions and de novo transcriptome assembly to construct a comprehensive sequence database containing information on the mechanisms of follicle development. A total of 157,774 unigenes (mean length: 790 bp) were obtained by the Trinity program, and 35.83% of these unigenes were matched to genes in a non-redundant protein database. Gene description, gene ontology, and the clustering of orthologous group terms were performed to annotate the transcriptome assembly. Differentially expressed genes between blue and white light conditions included those related to oocyte maturation, hormone biosynthesis, and circadian rhythm. Furthermore, 17,574 SSRs and 533,887 potential SNPs were identified in this transcriptome assembly. This work is the first transcriptome analysis of the Columba ovary using Illumina technology, and the resulting transcriptome and differentially expressed gene data can facilitate further investigations into the molecular mechanism of the effect of blue light on follicle development and reproduction in pigeons and other bird species. PMID:26599806

  8. Analysis of Pigeon (Columba Ovary Transcriptomes to Identify Genes Involved in Blue Light Regulation.

    Directory of Open Access Journals (Sweden)

    Ying Wang

    Full Text Available Monochromatic light is widely applied to promote poultry reproductive performance, yet little is currently known regarding the mechanism by which light wavelengths affect pigeon reproduction. Recently, high-throughput sequencing technologies have been used to provide genomic information for solving this problem. In this study, we employed Illumina Hiseq 2000 to identify differentially expressed genes in ovary tissue from pigeons under blue and white light conditions and de novo transcriptome assembly to construct a comprehensive sequence database containing information on the mechanisms of follicle development. A total of 157,774 unigenes (mean length: 790 bp were obtained by the Trinity program, and 35.83% of these unigenes were matched to genes in a non-redundant protein database. Gene description, gene ontology, and the clustering of orthologous group terms were performed to annotate the transcriptome assembly. Differentially expressed genes between blue and white light conditions included those related to oocyte maturation, hormone biosynthesis, and circadian rhythm. Furthermore, 17,574 SSRs and 533,887 potential SNPs were identified in this transcriptome assembly. This work is the first transcriptome analysis of the Columba ovary using Illumina technology, and the resulting transcriptome and differentially expressed gene data can facilitate further investigations into the molecular mechanism of the effect of blue light on follicle development and reproduction in pigeons and other bird species.

  9. Extinction Events Can Accelerate Evolution

    DEFF Research Database (Denmark)

    Lehman, Joel; Miikkulainen, Risto

    2015-01-01

    Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate...... evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending...... computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific...

  10. Avian poxvirus in a free-range juvenile speckled (rock pigeon (Columba guinea

    Directory of Open Access Journals (Sweden)

    Dauda G. Bwala

    2015-04-01

    Full Text Available A flightless wild juvenile rock pigeon (Columba guinea with pox-like lesions was picked up on the premises of the Faculty of Veterinary Science, University of Pretoria, Onderstepoort. The pigeon was housed overnight for possible treatment the following day but died before any other intervention could be instituted. At necropsy, coalescing masses of yellowish nodular cutaneous tumour-like lesions principally on the featherless areas were noticed on the dead pigeon’s head as well as the beak. Histological examination of the sampled skin lesions revealed multifocal areas of hypertrophic and hyperplastic epidermal epithelial cells with eosinophilic intracytoplasmic inclusion bodies (Bollinger bodies. Extract from the lesion was processed and inoculated on the chorioallantoic membranes (CAM of 11-day-old embryonated chicken eggs and this produced pocks on one of the CAM at day 7 post-inoculation. Electron microscopy confirmed the presence of poxvirus in the CAM with the pock lesions.

  11. Timing of extinction relative to acquisition: A parametric analysis of fear extinction in humans

    NARCIS (Netherlands)

    Norrholm, S.D.; Vervliet, B.; Jovanovic, T.; Boshoven, W.; Myers, K.M.; Davis, M.; Rothbaum, B.O.; Duncan, E.J.

    2008-01-01

    Fear extinction is a reduction in conditioned fear following repeated exposure to the feared cue in the absence of any aversive event. Extinguished fear often reappears after extinction through spontaneous recovery. Animal studies suggest that spontaneous recovery can be abolished if extinction

  12. Ocean passenger vessels : migrating south for the winter

    Science.gov (United States)

    2010-01-01

    In response to consumer demand, the passenger vessels that operate from seaports along the Atlantic, Gulf, and Pacific coasts alternate between north and south. Passenger vessels that sail out of ports such as New York, Baltimore and Seattle in the s...

  13. Detection of Magnetic Field Intensity Gradient by Homing Pigeons (Columba livia) in a Novel “Virtual Magnetic Map” Conditioning Paradigm

    Science.gov (United States)

    Mora, Cordula V.; Bingman, Verner P.

    2013-01-01

    It has long been thought that birds may use the Earth's magnetic field not only as a compass for direction finding, but that it could also provide spatial information for position determination analogous to a map during navigation. Since magnetic field intensity varies systematically with latitude and theoretically could also provide longitudinal information during position determination, birds using a magnetic map should be able to discriminate magnetic field intensity cues in the laboratory. Here we demonstrate a novel behavioural paradigm requiring homing pigeons to identify the direction of a magnetic field intensity gradient in a “virtual magnetic map” during a spatial conditioning task. Not only were the pigeons able to detect the direction of the intensity gradient, but they were even able to discriminate upward versus downward movement on the gradient by differentiating between increasing and decreasing intensity values. Furthermore, the pigeons typically spent more than half of the 15 second sampling period in front of the feeder associated with the rewarded gradient direction indicating that they required only several seconds to make the correct choice. Our results therefore demonstrate for the first time that pigeons not only can detect the presence and absence of magnetic anomalies, as previous studies had shown, but are even able to detect and respond to changes in magnetic field intensity alone, including the directionality of such changes, in the context of spatial orientation within an experimental arena. This opens up the possibility for systematic and detailed studies of how pigeons could use magnetic intensity cues during position determination as well as how intensity is perceived and where it is processed in the brain. PMID:24039812

  14. Comparison of pigeon guillemot, Cepphus columba, blood parameters from oiled and unoiled areas of Alaska eight years after the Exxon Valdez oil spill

    Science.gov (United States)

    Seiser, P.E.; Duffy, L.K.; McGuire, David A.; Roby, D.D.; Golet, Gregory H.; Litzow, Michael A.

    2000-01-01

    In 1997, we compared the haematological and plasma biochemical profiles among populations of pigeon guillemots, Cepphus columba, in areas oiled and not oiled by the 1989 Exxon Valdez oil spill (EVOS) that occurred in Prince William Sound (PWS), Alaska. Pigeon guillemot populations in PWS were injured by EVOS and have not returned to pre-spill levels. If oil contamination is limiting recovery of pigeon guillemots in PWS, then we expected that blood parameters of pigeon guillemots would differ between oiled and unoiled areas and that these differences would be consistent with either toxic responses or lower fitness. We collected blood samples from chicks at approximately 20 and 30 days after hatching. Physiological changes associated with chick growth were noted in several blood parameters. We found that only calcium and mean cell volume were significantly different between the chicks in oiled and unoiled areas. Despite these differences, blood biomarkers provided little evidence of continuing oil injury to pigeon guillemot chicks, eight years after the EVOS. Preliminary data from adults indicated elevated aspartate aminotransferase activity in the adults from the oiled area, which is consistent with hepatocellular injury. Because adults have greater opportunities for exposure to residual oil than nestlings, we recommend studies that fully evaluate the health of adults residing in oiled areas. (C) 2000 Elsevier Science Ltd.

  15. Genetic diversity of pigeon pea (Cajanus cajan (l.) Millsp.) based on molecular characterization using randomly amplified polymorphic DNA (RAPD) markers

    Science.gov (United States)

    Khoiriyah, N.; Yuniastuti, E.; Purnomo, D.

    2018-03-01

    Pigeon pea (Cajanus cajan (L.) Millsp.) is an annual leguminous crop (perennial) which has advantages over other local leguminous crops as drought resistant, hold collapsed and strong pods. The research on drought resistance plant is very important to adapt to climate change adverse impact to support food security. The potential of pigeon pie has not been supported by accurate data. To explore the potential of pigeon pea, it is necessary to record the important properties by characterization, one of which is molecular. Increasing genetic diversity can be done through mutation which widely used gamma ray for the induction. The purpose of this study was to identify the genetic diversity of pigeon pea of black, white and brown seeds type resulted by gamma-ray irradiation with a wavelength of 100, 200 and 300 grays by using RAPD method. The experiment resulted 14 bands, 12 of them are polymorphic bands and 2 of them are monomorphic with size varied from 300 bp to 1.3 kbp. The dendrogram showed from 30 accessions are divided into two main clusters, B shows clear genetical divergence from other clusters and some others split randomly. The range of similarity coefficient is from 0.43 to 1.00

  16. Identification of a Transcriptionally Forward α Gene and Two υ Genes within the Pigeon (Columba livia) IgH Gene Locus.

    Science.gov (United States)

    Huang, Tian; Wang, Xifeng; Si, Run; Chi, Hao; Han, Binyue; Han, Haitang; Cao, Gengsheng; Zhao, Yaofeng

    2018-06-01

    Compared with mammals, the bird Ig genetic system relies on gene conversion to create an Ab repertoire, with inversion of the IgA-encoding gene and very few cases of Ig subclass diversification. Although gene conversion has been studied intensively, class-switch recombination, a mechanism by which the IgH C region is exchanged, has rarely been investigated in birds. In this study, based on the published genome of pigeon ( Columba livia ) and high-throughput transcriptome sequencing of immune-related tissues, we identified a transcriptionally forward α gene and found that the pigeon IgH gene locus is arranged as μ-α-υ1-υ2. In this article, we show that both DNA deletion and inversion may result from IgA and IgY class switching, and similar junction patterns were observed for both types of class-switch recombination. We also identified two subclasses of υ genes in pigeon, which share low sequence identity. Phylogenetic analysis suggests that divergence of the two pigeon υ genes occurred during the early stage of bird evolution. The data obtained in this study provide new insight into class-switch recombination and Ig gene evolution in birds. Copyright © 2018 by The American Association of Immunologists, Inc.

  17. Isolation and molecular characterization of Cryptococcus species isolated from pigeon nests and Eucalyptus trees

    Directory of Open Access Journals (Sweden)

    Abuzar Kamari

    2017-06-01

    Conclusion: The presence of pigeons and Eucalyptus trees in the vicinity of some particular places such as rest homes and hospitals should be considered as a risk factor for the immunocompromised population.  

  18. Rescaling of temporal expectations during extinction

    Science.gov (United States)

    Drew, Michael R.; Walsh, Carolyn; Balsam, Peter D

    2016-01-01

    Previous research suggests that extinction learning is temporally specific. Changing the CS duration between training and extinction can facilitate the loss of the CR within the extinction session but impairs long-term retention of extinction. In two experiments using conditioned magazine approach with rats, we examined the relation between temporal specificity of extinction and CR timing. In Experiment 1 rats were trained on a 12-s, fixed CS-US interval and then extinguished with CS presentations that were 6, 12, or 24 s in duration. The design of Experiment 2 was the same except rats were trained using partial rather than continuous reinforcement. In both experiments, extending the CS duration in extinction facilitated the diminution of CRs during the extinction session, but shortening the CS duration failed to slow extinction. In addition, extending (but not shortening) the CS duration caused temporal rescaling of the CR, in that the peak CR rate migrated later into the trial over the course of extinction training. This migration partially accounted for the faster loss of the CR when the CS duration was extended. Results are incompatible with the hypothesis that extinction is driven by cumulative CS exposure and suggest that temporally extended nonreinforced CS exposure reduces conditioned responding via temporal displacement rather than through extinction per se. PMID:28045291

  19. Designing Train Passenger Seat by Kansei Engineering in Indonesia

    Directory of Open Access Journals (Sweden)

    Hapsari Sakya Nabila

    2017-01-01

    Full Text Available Public transport adoption is still major problem in Indonesia. Integrating impression and emotion to service may change the image of public transport, leading to fast adoption rate. As product development technique, Kansei Engineering is well known to facilitate that integration. This paper communicates the implementation of Kansei Engineering (KE in designing train passenger seat in Indonesia. The train between Bandung-Solo (8 hours journey was chosen to be the investigated object. The train was selected to be refurbished by introducing a new passenger seat design, emphasizing on the improvement of passenger experience. As the first step of KE type I technique, travel experience of the existing passengers were taken into the consideration for selecting Kansei words. It was found that the relevant Kansei words to design passenger train seat in Indonesia were: comfort, people-friendly, multifunction, safe, soft, spacious, relaxing, superior, maintainable, strong, producible, minimalist, attractive, modern, unique, and durable. Upon understanding the semantic meaning of those words, physical properties and technical specification were produced by consulting to the related members. Finally, a passenger seat with synthetic leather cover, modular design, foldable table, individual power point, bluesilver color, and adjusted to Indonesian’s anthropometry data was proposed as the final design

  20. End Ordovician extinctions

    DEFF Research Database (Denmark)

    Harper, David A. T.; Hammarlund, Emma; Rasmussen, Christian M. Ø.

    2014-01-01

    -global anoxia associated with a marked transgression during the Late Hirnantian. Most recently, however, new drivers for the extinctions have been proposed, including widespread euxinia together with habitat destruction caused by plate tectonic movements, suggesting that the end Ordovician mass extinctions were...

  1. High-Speed Train Stop-Schedule Optimization Based on Passenger Travel Convenience

    OpenAIRE

    Dingjun Chen; Shaoquan Ni; Chang’an Xu; Hongxia Lv; Simin Wang

    2016-01-01

    The stop-schedules for passenger trains are important to the operation planning of high-speed trains, and they decide the quality of passenger service and the transportation efficiency. This paper analyzes the specific manifestation of passenger travel convenience and proposes the concepts of interstation accessibility and degree of accessibility. In consideration of both the economic benefits of railway corporations and the travel convenience of passengers, a multitarget optimization model i...

  2. Extinction of NGC 7027

    International Nuclear Information System (INIS)

    Seaton, M.J.

    1979-01-01

    Emission intensities of recombination lines in hydrogenic spectra are known accurately relative to intensities in the free-free radio continuum. For NGC 7027 intensities have been measured for the radio continuum and for H I and He II lines in the wavelength range from lambda = 2.17 μm to lambda = 1640 A: comparison with the calculated emission intensities gives the extinction. Determinations of the standard interstellar extinction function are critically discussed. The extinction deduced for the total radiation from NGC 7027 has a dependence on wavelength for 6563 A >= lambda >= 1640 A which is in excellent agreement with the adopted standard results, but there are some anomalies for longer wavelengths and for the ratio of total to selective extinction. These can be explained using a model which allows for a local contribution to the extinction which is variable over the surface of the nebula. (author)

  3. Airline Passengers

    OpenAIRE

    Wittmer, Andreas; Hinnen, Gieri

    2016-01-01

    Airlines create value for employees, investors, governments, customers and consumers. This chapter focuses on the customers and consumers of the airline product. Airline customers, who include passengers and corporate travel providers, exert considerable market power in the air transport industry through their purchasing decisions and travel behaviour. As a purchaser of a commercial aviation product, customers are responsible for stimulating product and service innovation and their behaviour ...

  4. Extinction with multiple excitors

    OpenAIRE

    McConnell, Bridget L.; Miguez, Gonzalo; Miller, Ralph R.

    2013-01-01

    Four conditioned suppression experiments with rats, using an ABC renewal design, investigated the effects of compounding the target conditioned excitor with additional, nontarget conditioned excitors during extinction. Experiment 1 showed stronger extinction, as evidenced by less renewal, when the target excitor was extinguished in compound with a second excitor, relative to when it was extinguished with associatively neutral stimuli. Critically, this deepened extinction effect was attenuated...

  5. Molecular cloning and tissue distribution of peroxisome proliferator-activated receptor-alpha (PPARα) and gamma (PPARγ) in the pigeon (Columba livia domestica).

    Science.gov (United States)

    Xie, P; Yuan, C; Wang, C; Zou, X-T; Po, Z; Tong, H-B; Zou, J-M

    2014-01-01

    1. Peroxisome proliferator-activated receptors (PPAR) are involved in lipid metabolism through transcriptional regulation of target gene expression. The objective of the current study was to clone and characterise the PPARα and PPARγ genes in pigeon. 2. The full-length of 1941-bp PPARα and 1653-bp PPARγ were cloned from pigeons. The two genes were predicted to encode 468 and 475 amino acids, respectively. Both proteins contained two C4-type zinc fingers, a nuclear hormone receptor DNA-binding region signature and a HOLI domain (ligand binding domain of hormone receptors), and had high identities with other corresponding avian genes. 3. Using quantitative real-time PCR, pigeon PPARα gene expression was shown to be high in kidney, liver, gizzard and duodenum whereas PPARγ was predominantly expressed in adipose tissue.

  6. Is IR going extinct?

    Science.gov (United States)

    Mitchell, Audra

    2016-01-01

    A global extinction crisis may threaten the survival of most existing life forms. Influential discourses of ‘existential risk’ suggest that human extinction is a real possibility, while several decades of evidence from conservation biology suggests that the Earth may be entering a ‘sixth mass extinction event’. These conditions threaten the possibilities of survival and security that are central to most branches of International Relations. However, this discipline lacks a framework for addressing (mass) extinction. From notions of ‘nuclear winter’ and ‘omnicide’ to contemporary discourses on catastrophe, International Relations thinking has treated extinction as a superlative of death. This is a profound category mistake: extinction needs to be understood not in the ontic terms of life and death, but rather in the ontological context of be(com)ing and negation. Drawing on the work of theorists of the ‘inhuman’ such as Quentin Meillassoux, Claire Colebrook, Ray Brassier, Jean-Francois Lyotard and Nigel Clark, this article provides a pathway for thinking beyond existing horizons of survival and imagines a profound transformation of International Relations. Specifically, it outlines a mode of cosmopolitics that responds to the element of the inhuman and the forces of extinction. Rather than capitulating to narratives of tragedy, this cosmopolitics would make it possible to think beyond the restrictions of existing norms of ‘humanity’ to embrace an ethics of gratitude and to welcome the possibility of new worlds, even in the face of finitude.

  7. Getting Frustrated: Modelling Emotion Contagion in Stranded Passengers

    NARCIS (Netherlands)

    van der Wal, C. Natalie; Couwenberg, Maik; Bosse, T.

    2017-01-01

    Train passengers can get stranded due to a variety of events, such as a delay, technical malfunctioning or a natural disaster. Stranded passengers can get frustrated, which could escalate in misbehaviours. Examples are verbal and physical violence or dangerous behaviours such as opening emergency

  8. Frequency of endophytic fungi isolated from Dendrobium crumenatum (Pigeon orchid and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    WIBOWO MANGUNWARDOYO

    2012-01-01

    Full Text Available Mangunwardoyo W, Suciatmih, Gandjar I. 2012. Frequency of endophytic fungi isolated from Dendrobium crumenatum (Pigeon orchid and antimicrobial activity. Biodiversitas 13: 34-39. The aims of this research was to isolate and study the frequency of endophytic fungi from roots, bulbous, stems, and leaves of Dendrobium crumenatum Sw. (pigeon orchid collected from Tanah Baru housing area, Bogor Botanical Garden, and Herbarium Bogoriense; and to assess for antimicrobial activity against Candida albicans ATCC 2091, Candida tropicalis LIPIMC 203, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 25923. Twelve species of endophytic fungi were identified from 60 samples obtained from D. crumenatum. Guignardia endophyllicola (anamorph: Phyllosticta capitalensis were the dominant endophytic fungi. Screening of the anti-microorganism activity of the endophytic fungi revealed that Fusarium nivale inhibited C albicans and C. tropicalis. All specimens did not inhibit B. subtilis, E. coli, and S. aureus.

  9. Breeding high yielding varieties of pigeon pea, mungbean and black gram using induced mutations

    International Nuclear Information System (INIS)

    Pawar, S.E.; Wanjari, K.B.

    1994-01-01

    The present communication emphasis the developing of high yielding varieties of pigeon pea, mungbean and black gram using induced mutation with disease resistance in these crops. This would help in stabilisation of the higher yield potential

  10. Diarrhea and related factors among passengers on world cruises departing from Japan.

    Science.gov (United States)

    Yamakawa, Michiyo; Sasai, Megumi; Kasai, Yosuke; Tsuda, Toshihide; Suzuki, Etsuji

    2018-01-25

    Despite growth in the number of cruises worldwide, evidence about diarrhea experienced by cruise ship passengers remains sparse. We investigated rates of diarrhea and related factors among passengers on world cruises departing from Japan. Targeting passengers on five world cruises (n = 4180) from 2012 to 2013 (85-103 travel days), we calculated rates of health seeking behavior for diarrhea by sex, age group, and number of roommates for each cruise. We estimated rate ratios and 95% confidence intervals, using the group aged 20-39 years, women, and 2-4 roommates as referent categories. We found 5.04-6.00 cases per 10,000 person-days in the five cruises, with an elevated number after calling at ports. Older passengers (>60 years) and passengers with fewer roommates had an elevated risk of health seeking behavior for diarrhea, although passengers aged 60 years and without roommates. Older passengers and passengers with fewer roommates may be more likely to seek medical treatment for diarrhea during travel on a world cruise, and should take preventive measures. Copyright © 2018. Published by Elsevier Ltd.

  11. The currency and tempo of extinction.

    Science.gov (United States)

    Regan, H M; Lupia, R; Drinnan, A N; Burgman, M A

    2001-01-01

    This study examines estimates of extinction rates for the current purported biotic crisis and from the fossil record. Studies that compare current and geological extinctions sometimes use metrics that confound different sources of error and reflect different features of extinction processes. The per taxon extinction rate is a standard measure in paleontology that avoids some of the pitfalls of alternative approaches. Extinction rates reported in the conservation literature are rarely accompanied by measures of uncertainty, despite many elements of the calculations being subject to considerable error. We quantify some of the most important sources of uncertainty and carry them through the arithmetic of extinction rate calculations using fuzzy numbers. The results emphasize that estimates of current and future rates rely heavily on assumptions about the tempo of extinction and on extrapolations among taxa. Available data are unlikely to be useful in measuring magnitudes or trends in current extinction rates.

  12. Dynamical Modeling of Collective Behavior from Pigeon Flight Data: Flock Cohesion and Dispersion

    Science.gov (United States)

    Xu, Xiao-Ke; Small, Michael

    2012-01-01

    Several models of flocking have been promoted based on simulations with qualitatively naturalistic behavior. In this paper we provide the first direct application of computational modeling methods to infer flocking behavior from experimental field data. We show that this approach is able to infer general rules for interaction, or lack of interaction, among members of a flock or, more generally, any community. Using experimental field measurements of homing pigeons in flight we demonstrate the existence of a basic distance dependent attraction/repulsion relationship and show that this rule is sufficient to explain collective behavior observed in nature. Positional data of individuals over time are used as input data to a computational algorithm capable of building complex nonlinear functions that can represent the system behavior. Topological nearest neighbor interactions are considered to characterize the components within this model. The efficacy of this method is demonstrated with simulated noisy data generated from the classical (two dimensional) Vicsek model. When applied to experimental data from homing pigeon flights we show that the more complex three dimensional models are capable of simulating trajectories, as well as exhibiting realistic collective dynamics. The simulations of the reconstructed models are used to extract properties of the collective behavior in pigeons, and how it is affected by changing the initial conditions of the system. Our results demonstrate that this approach may be applied to construct models capable of simulating trajectories and collective dynamics using experimental field measurements of herd movement. From these models, the behavior of the individual agents (animals) may be inferred. PMID:22479176

  13. Dynamical modeling of collective behavior from pigeon flight data: flock cohesion and dispersion.

    Directory of Open Access Journals (Sweden)

    Graciano Dieck Kattas

    Full Text Available Several models of flocking have been promoted based on simulations with qualitatively naturalistic behavior. In this paper we provide the first direct application of computational modeling methods to infer flocking behavior from experimental field data. We show that this approach is able to infer general rules for interaction, or lack of interaction, among members of a flock or, more generally, any community. Using experimental field measurements of homing pigeons in flight we demonstrate the existence of a basic distance dependent attraction/repulsion relationship and show that this rule is sufficient to explain collective behavior observed in nature. Positional data of individuals over time are used as input data to a computational algorithm capable of building complex nonlinear functions that can represent the system behavior. Topological nearest neighbor interactions are considered to characterize the components within this model. The efficacy of this method is demonstrated with simulated noisy data generated from the classical (two dimensional Vicsek model. When applied to experimental data from homing pigeon flights we show that the more complex three dimensional models are capable of simulating trajectories, as well as exhibiting realistic collective dynamics. The simulations of the reconstructed models are used to extract properties of the collective behavior in pigeons, and how it is affected by changing the initial conditions of the system. Our results demonstrate that this approach may be applied to construct models capable of simulating trajectories and collective dynamics using experimental field measurements of herd movement. From these models, the behavior of the individual agents (animals may be inferred.

  14. Immediate extinction causes a less durable loss of performance than delayed extinction following either fear or appetitive conditioning

    OpenAIRE

    Woods, Amanda M.; Bouton, Mark E.

    2008-01-01

    Five experiments with rat subjects compared the effects of immediate and delayed extinction on the durability of extinction learning. Three experiments examined extinction of fear conditioning (using the conditioned emotional response method), and two experiments examined extinction of appetitive conditioning (using the food-cup entry method). In all experiments, conditioning and extinction were accomplished in single sessions, and retention testing took place 24 h after extinction. In both f...

  15. Methods for analysis of passenger trip performance in a complex networked transportation system

    Science.gov (United States)

    Wang, Danyi

    2007-12-01

    The purpose of the Air Transportation System (ATS) is to provide safe and efficient transportation service of passengers and cargo. The on-time performance of a passenger's trip is a critical performance measurement of the Quality of Service (QOS) provided by any Air Transportation System. QOS has been correlated with airline profitability, productivity, customer loyalty and customer satisfaction (Heskett et al. 1994). Btatu and Barnhart have shown that official government and airline on-time performance metrics (i.e. flight-centric measures of air transportation) fail to accurately reflect the passenger experience (Btatu and Barnhart, 2005). Flight-based metrics do not include the trip delays accrued by passengers who were re-booked due to cancelled flights or missed connections. Also, flight-based metrics do not quantify the magnitude of the delay (only the likelihood) and thus fails to provide the consumer with a useful assessment of the impact of a delay. Passenger-centric metrics have not been developed because of the unavailability of airline proprietary data, which is also protected by anti-trust collusion concerns and civil liberty privacy restrictions. Moveover, the growth of the ATS is trending out of the historical range. The objectives of this research were to (1) estimate ATS-wide passenger trip delay using publicly accessible flight data, and (2) investigate passenger trip dynamics out of the range of historical data by building a passenger flow simulation model to predict impact on passenger trip time given anticipated changes in the future. The first objective enables researchers to conduct historical analysis on passenger on-time performance without proprietary itinerary data, and the second objective enables researchers to conduct experiments outside the range of historic data. The estimated passenger trip delay was for 1,030 routes between the 35 busiest airports in the United States in 2006. The major findings of this research are listed as

  16. Ejection of a rear facing, golf cart passenger.

    Science.gov (United States)

    Schau, Kyle; Masory, Oren

    2013-10-01

    The following report details the findings of a series of experiments and simulations performed on a commercially available, shuttle style golf cart during several maneuvers involving rapid accelerations of the vehicle. It is determined that the current set of passive restraints on these types of golf carts are not adequate in preventing ejection of a rear facing passenger during rapid accelerations in the forward and lateral directions. Experimental data and simulations show that a hip restraint must be a minimum of 13 in. above the seat in order to secure a rear facing passenger during sharp turns, compared to the current restraint height of 5 in. Furthermore, it is determined that a restraint directly in front of the rear facing passenger is necessary to prevent ejection. In addressing these issues, golf cart manufacturers could greatly reduce the likelihood of injury due to ejection of a rear facing, golf cart passenger. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Experimental infection with highly pathogenic H5N8 avian influenza viruses in the Mandarin duck (Aix galericulata) and domestic pigeon (Columba livia domestica).

    Science.gov (United States)

    Kwon, Jung-Hoon; Noh, Yun Kyung; Lee, Dong-Hun; Yuk, Seong-Su; Erdene-Ochir, Tseren-Ochir; Noh, Jin-Yong; Hong, Woo-Tack; Jeong, Jei-Hyun; Jeong, Sol; Gwon, Gyeong-Bin; Song, Chang-Seon; Nahm, Sang-Soep

    2017-05-01

    Wild birds play a major role in the evolution, maintenance, and dissemination of highly pathogenic avian influenza viruses (HPAIV). Sub-clinical infection with HPAI in resident wild birds could be a source of dissemination of HPAIV and continuous outbreaks. In this study, the pathogenicity and infectivity of two strains of H5N8 clade 2.3.4.4 virus were evaluated in the Mandarin duck (Aix galericulata) and domestic pigeon (Columba livia domestica). None of the birds experimentally infected with H5N8 viruses showed clinical signs or mortality. The H5N8 viruses efficiently replicated in the virus-inoculated Mandarin ducks and transmitted to co-housed Mandarin ducks. Although relatively high levels of viral shedding were noted in pigeons, viral shedding was not detected in some of the pigeons and the shedding period was relatively short. Furthermore, the infection was not transmitted to co-housed pigeons. Immunohistochemical examination revealed the presence of HPAIV in multiple organs of the infected birds. Histopathological evaluation showed the presence of inflammatory responses primarily in HPAIV-positive organs. Our results indicate that Mandarin ducks and pigeons can be infected with H5N8 HPAIV without exhibiting clinical signs; thus, they may be potential healthy reservoirs of the H5N8 HPAIV. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Extinction risk escalates in the tropics.

    Directory of Open Access Journals (Sweden)

    Jana C Vamosi

    Full Text Available The latitudinal biodiversity gradient remains one of the most widely recognized yet puzzling patterns in nature. Presently, the high level of extinction of tropical species, referred to as the "tropical biodiversity crisis", has the potential to erode this pattern. While the connection between species richness, extinction, and speciation has long intrigued biologists, these interactions have experienced increased poignancy due to their relevancy to where we should concentrate our conservation efforts. Natural extinction is a phenomenon thought to have its own latitudinal gradient, with lower extinction rates in the tropics being reported in beetles, birds, mammals, and bivalves. Processes that have buffered ecosystems from high extinction rates in the past may also buffer ecosystems against disturbance of anthropogenic origin. While potential parallels between historical and present-day extinction patterns have been acknowledged, they remain only superficially explored and plant extinction patterns have been particularly neglected. Studies on the disappearances of animal species have reached conflicting conclusions, with the rate of extinction appearing either higher or lower in species richness hotspots. Our global study of extinction risk in vascular plants finds disproportionately higher extinction risk in tropical countries, even when indicators of human pressure (GDP, population density, forest cover change are taken into account. Our results are at odds with the notion that the tropics represent a museum of plant biodiversity (places of historically lowered extinction and we discuss mechanisms that may reconcile this apparent contradiction.

  19. Extinction risk escalates in the tropics.

    Science.gov (United States)

    Vamosi, Jana C; Vamosi, Steven M

    2008-01-01

    The latitudinal biodiversity gradient remains one of the most widely recognized yet puzzling patterns in nature. Presently, the high level of extinction of tropical species, referred to as the "tropical biodiversity crisis", has the potential to erode this pattern. While the connection between species richness, extinction, and speciation has long intrigued biologists, these interactions have experienced increased poignancy due to their relevancy to where we should concentrate our conservation efforts. Natural extinction is a phenomenon thought to have its own latitudinal gradient, with lower extinction rates in the tropics being reported in beetles, birds, mammals, and bivalves. Processes that have buffered ecosystems from high extinction rates in the past may also buffer ecosystems against disturbance of anthropogenic origin. While potential parallels between historical and present-day extinction patterns have been acknowledged, they remain only superficially explored and plant extinction patterns have been particularly neglected. Studies on the disappearances of animal species have reached conflicting conclusions, with the rate of extinction appearing either higher or lower in species richness hotspots. Our global study of extinction risk in vascular plants finds disproportionately higher extinction risk in tropical countries, even when indicators of human pressure (GDP, population density, forest cover change) are taken into account. Our results are at odds with the notion that the tropics represent a museum of plant biodiversity (places of historically lowered extinction) and we discuss mechanisms that may reconcile this apparent contradiction.

  20. Antibiotic resistance in Escherichia coli isolates from roof-harvested rainwater tanks and urban pigeon faeces as the likely source of contamination.

    Science.gov (United States)

    Chidamba, Lizyben; Korsten, Lise

    2015-07-01

    The objective of this study was to investigate the risks associated with the use of roof-harvested rainwater (RHRW) and the implication of pigeons as the most likely source of contamination by testing for antibiotic resistance profiles of Escherichia coli. A total of 239 E. coli were isolated from thirty fresh pigeon faecal samples (130 isolates), 11 RHRW tanks from three sites in Pretoria (78) and two in Johannesburg (31). E. coli isolates were tested against a panel of 12 antibiotics which included ampicillin, amoxicillin, amikacin, cefoxitin, ceftriaxone, chloramphenicol, ciprofloxacin, cotrimoxazole, enrofloxacin, gentamicin, nalidixic acid and tetracycline. In all samples, resistance to ampicillin (22.7.9%), gentamicin (23.6%), amikacin (24%), tetracycline (17.4) and amoxicillin (16.9%) were the most frequently encountered form of resistance. However, a relatively higher proportion of isolates from pigeon faeces (67.3%) were antibiotic resistant than those from RHRW (53.3%). The highest number of phenotypes was observed for single antibiotics, and no single antibiotic resistance was observed for chloramphenicol, ceftriaxone, gentamicin, cefoxitin, cotrimoxazole, although they were detected in multiple antibiotic resistance (MAR) phenotypes. The highest multiple antibiotic resistance (MAR) phenotypes were observed for a combination of four antibiotics, on isolates from JHB (18.8%), pigeon faeces (15.2%) and Pretoria (5.1%). The most abundant resistance phenotype to four antibiotics, Ak-Gm-Cip-T was dominated by isolates from pigeon faeces (6.8%) with Pretoria and Johannesburg isolates having low proportions of 1.3 and 3.1%, respectively. Future studies should target isolates from various environmental settings in which rainwater harvesting is practiced and the characterisation of the antibiotic resistance determinant genes among the isolates.

  1. Linking landscape characteristics to mineral site use by band-tailed pigeons in Western Oregon: Coarse-filter conservation with fine-filter tuning

    Science.gov (United States)

    Overton, C.T.; Schmitz, R.A.; Casazza, Michael L.

    2006-01-01

    Mineral sites are scarce resources of high ion concentration used heavily by the Pacific Coast subpopulation of band-tailed pigeons. Over 20% of all known mineral sites used by band-tailed pigeons in western Oregon, including all hot springs, have been abandoned. Prior investigations have not analyzed stand or landscape level habitat composition in relation to band-tailed pigeon use of mineral sites. We used logistic regression models to evaluate the influence of habitat types, identified from Gap Analysis Program (GAP) products at two spatial scales, on the odds of mineral site use in Oregon (n = 69 currently used and 20 historically used). Our results indicated that the odds of current use were negatively associated with non-forested terrestrial and private land area around mineral sites. Similarly, the odds of current mineral site use were positively associated with forested and special status (GAP stewardship codes 1 and 2) land area. The most important variable associated with the odds of mineral site use was the amount of non-forested land cover at either spatial scale. Our results demonstrate the utility of meso-scale geographic information designed for regional, coarse-filter approaches to conservation in fine-filter investigation of wildlife-habitat relationships. Adjacent landcover and ownership status explain the pattern of use for known mineral sites in western Oregon. In order for conservation and management activities for band-tailed pigeons to be successful, mineral sites need to be addressed as important and vulnerable resources. Management of band-tailed pigeons should incorporate the potential for forest management activities and land ownership patterns to influence the risk of mineral site abandonment.

  2. Evaluation of gastrointestinal tract transit times using barium-impregnated polyethylene spheres and barium sulfate suspension in a domestic pigeon (Columba livia) model.

    Science.gov (United States)

    Bloch, Rebecca A; Cronin, Kimberly; Hoover, John P; Pechman, Robert D; Payton, Mark E

    2010-03-01

    Barium impregnated polyethylene spheres (BIPS) are used in small animal medicine as an alternative to barium sulfate for radiographic studies of the gastrointestinal tract. To determine the usefulness of BIPS as an alternative to barium suspension in measuring gastrointestinal (GI) transit time for avian species, ventrodorsal radiographs were used to follow the passage of BIPS and 30% barium sulfate suspension through the GI tracts of domestic pigeons (Columba livia). Gastrointestinal transit times of thirty 1.5-mm BIPS administered in moistened gelatin capsules and 30% barium sulfate suspension gavaged into the crop were compared in 6 pigeons. Although the barium suspension passed out of the GI tract of all pigeons within 24 hours, the 1.5-mm BIPS remained in the ventriculus for 368.0 +/- 176.8 hours and did not clear the GI tract for 424.0 +/- 204.6 hours. Although the times for passage of BIPS and 30% barium sulfate suspension from the crop into the ventriculus were not significantly different (P = .14), the times for passage of BIPS from the ventriculus into the large intestine-cloaca and for clearance from the GI tract of the pigeons were significantly longer (P barium sulfate suspension. From the results of this study, we conclude that BIPS are not useful for radiographically evaluating GI transit times in pigeons and are unlikely to be useful in other avian species that have a muscular ventriculus. BIPS may or may not be useful for evaluating GI transit times in species that lack a muscular ventriculus.

  3. A Model of Bus Bunching under Reliability-based Passenger Arrival Patterns

    OpenAIRE

    Fonzone, Achille; Schmöcker, Jan-Dirk; Liu, Ronghui

    2015-01-01

    If bus service departure times are not completely unknown to the passengers, non-uniform passenger arrival patterns can be expected. We propose that passengers decide their arrival time at stops based on a continuous logit model that considers the risk of missing services. Expected passenger waiting times are derived in a bus system that allows also for overtaking between bus services. We then propose an algorithm to derive the dwell time of subsequent buses serving a stop in order to illustr...

  4. Estimating passenger numbers in trains using existing weighing capabilities

    DEFF Research Database (Denmark)

    Nielsen, Bo Friis; Frølich, Laura; Nielsen, Otto Anker

    2013-01-01

    trains to control braking. This technique makes passenger counting cheaper and ensures a complete sample. The paper compares numbers estimated by this technique with manual counts and counts from an infrared system in trains in urban Copenhagen. It shows that the weighing system provides more accurate......Knowing passenger numbers is important for the planning and operation of the urban rail systems. Manual and electronic counting systems (typically infrared or video) are expensive and therefore entail small sample sizes. They usually count boarding and alighting passengers, which means that errors...... in estimates of total numbers of passengers propagate along train runs. Counting errors in manual and electronic counting systems are typically flow-dependent, making uncertainty a function of volume. This paper presents a new counting technique that exploits the weighing systems installed in most modern...

  5. Purification, crystallization and preliminary X-ray diffraction studies on avian haemoglobin from pigeon (Columba livia)

    Science.gov (United States)

    Sathya Moorthy, Pon.; Neelagandan, K.; Balasubramanian, M.; Ponnuswamy, M. N.

    2009-01-01

    Haemoglobin is a physiologically significant metalloprotein that is involved in the exchange of gases for sustaining life. The respiratory system of birds is unique and complex compared with that of mammals. Many investigations of avian haemoglobins have revealed the presence of inositol pentaphosphate (IP5), a principal allosteric effector that is involved in regulation of their function. Structural investigations of avian haemoglobins are presently not adequate to explain their function. Efforts have been made in this direction in order to understand the oxygen-binding affinity involved in adapting to hypoxia in avian haemoglobins. Fresh whole blood was collected from pigeon (Columba livia) and purified using a DEAE cellulose anion-exchange chromatographic column. Crystallization of pigeon haemoglobin was accomplished using the hanging-drop vapour-diffusion method using PEG 3350 as a precipitant in 50 mM sodium acetate buffer pH 5.5 with 1 M NaCl. Data collection was carried out using a MAR345 image-plate detector system. The crystals diffracted to 2 Å resolution. Pigeon haemoglobin crystallizes in a triclinic space group, with two whole biological molecules in the asymmetric unit and with unit-cell parameters a = 55.005, b = 65.528, c = 104.370 Å, α = 78.742, β = 89.819, γ = 65.320°. PMID:19194000

  6. 49 CFR 583.10 - Outside suppliers of passenger motor vehicle equipment.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Outside suppliers of passenger motor vehicle... CONTENT LABELING § 583.10 Outside suppliers of passenger motor vehicle equipment. (a) For each unique type of passenger motor vehicle equipment for which a manufacturer or allied supplier requests information...

  7. Suboptimal Choice in Pigeons: Stimulus Value Predicts Choice over Frequencies.

    Directory of Open Access Journals (Sweden)

    Aaron P Smith

    Full Text Available Pigeons have shown suboptimal gambling-like behavior when preferring a stimulus that infrequently signals reliable reinforcement over alternatives that provide greater reinforcement overall. As a mechanism for this behavior, recent research proposed that the stimulus value of alternatives with more reliable signals for reinforcement will be preferred relatively independently of their frequencies. The present study tested this hypothesis using a simplified design of a Discriminative alternative that, 50% of the time, led to either a signal for 100% reinforcement or a blackout period indicative of 0% reinforcement against a Nondiscriminative alternative that always led to a signal that predicted 50% reinforcement. Pigeons showed a strong preference for the Discriminative alternative that remained despite reducing the frequency of the signal for reinforcement in subsequent phases to 25% and then 12.5%. In Experiment 2, using the original design of Experiment 1, the stimulus following choice of the Nondiscriminative alternative was increased to 75% and then to 100%. Results showed that preference for the Discriminative alternative decreased only when the signals for reinforcement for the two alternatives predicted the same probability of reinforcement. The ability of several models to predict this behavior are discussed, but the terminal link stimulus value offers the most parsimonious account of this suboptimal behavior.

  8. Rescuing Ecosystems from Extinction Cascades

    Science.gov (United States)

    Sahasrabudhe, Sagar; Motter, Adilson

    2010-03-01

    Food web perturbations stemming from climate change, overexploitation, invasive species, and natural disasters often cause an initial loss of species that results in a cascade of secondary extinctions. Using a predictive modeling framework, here we will present a systematic network-based approach to reduce the number of secondary extinctions. We will show that the extinction of one species can often be compensated by the concurrent removal of a second specific species, which is a counter-intuitive effect not previously tested in complex food webs. These compensatory perturbations frequently involve long-range interactions that are not a priori evident from local predator-prey relationships. Strikingly, in numerous cases even the early removal of a species that would eventually be extinct by the cascade is found to significantly reduce the number of cascading extinctions. Other nondestructive interventions based on partial removals and growth suppression and/or mortality increase are shown to sometimes prevent all secondary extinctions.

  9. The Research of China's Civil Aviation Passenger Multi-Channel Service Technology Platform

    Science.gov (United States)

    Zhibing, Xue; Xinming, Wang

    IATA is promoting Simplifying the Business. The traditional passenger services and business process, such as ticketing, airport counters, had a great influence. The airlines have the passenger service and convenience as the next product development requirements. With civil aviation industry and their company's products construction, the authors propose a solution of passenger multi-channel service product platform. The solution is to streamline the business as the breakthrough point, around the convenience of passengers travel services to travelers as the center, using the current mainstream and the latest IT technology to establish passenger service product platform. The solution will promote DCS e-ticketing business development and service channel diversity. In this paper, the research results have been applied in the product platform construction of the authors' company. The practice shows that through traditional business with the latest IT technologies, traditional passenger services into the emerging service model, passenger service product platform has strong advantages and characteristics. Based on the platform, various types of service products is growing rapidly.

  10. Monitoring air pollution at Mohammedia (Morocco): Pb, Cd and Zn in the blood of pigeons (Columba livia).

    Science.gov (United States)

    Kouddane, N; Mouhir, L; Fekhaoui, M; Elabidi, A; Benaakame, R

    2016-05-01

    The concentrations of Pb, Cd and Zn were investigated in the blood of pigeons (Columba livia) in order to assess the degree of pollution by heavy metal. For this, wild city pigeons were caught at four different locations in Mohammedia classified according to their industrial activity and road traffic density. Significant difference in heavy metal concentrations were observed between sites studied, the highest lead and cadmium levels were found in industrial area and center town, while the highest zinc level was found in the less contaminated area. These results indicate that the industrial activities and the road traffic are the most important source of pollution.

  11. 46 CFR 176.910 - Passenger Ship Safety Certificate.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Passenger Ship Safety Certificate. 176.910 Section 176... 100 GROSS TONS) INSPECTION AND CERTIFICATION International Convention for Safety of Life at Sea, 1974, as Amended (SOLAS) § 176.910 Passenger Ship Safety Certificate. (a) A vessel, which carries more than...

  12. 36 CFR 13.1316 - Commercial transport of passengers by motor vehicles.

    Science.gov (United States)

    2010-07-01

    ... passengers by motor vehicles. 13.1316 Section 13.1316 Parks, Forests, and Public Property NATIONAL PARK... National Park General Provisions § 13.1316 Commercial transport of passengers by motor vehicles. Commercial transport of passengers by motor vehicles on Exit Glacier Road is allowed without a written permit. However...

  13. 49 CFR 583.11 - Allied suppliers of passenger motor vehicle equipment.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Allied suppliers of passenger motor vehicle... CONTENT LABELING § 583.11 Allied suppliers of passenger motor vehicle equipment. (a) For each unique type of passenger motor vehicle equipment which an allied supplier supplies to the manufacturer with which...

  14. Convenient Airports: Point of View of the Passengers

    Science.gov (United States)

    Magri, Adival Aparecido, Jr.; Alves, Claudio Jorge Pinto

    2003-01-01

    The competition among airlines or among airports aiming at to increase the demand for its services has been more and more incited. Knowledge the perception of the users for the offered services means to meet the customer's needs and expectations in order either to keep the customer, and therefore keep a significant advantage over competitors. The passenger of the air transportation wants rapidity, security and convenience. Convenience can be translated by comfort that the passenger wants for the price that he can pay. In this paper had been identified. as a result of a survey achieved in six Brazilian airports during 2002, the best indicators in the passenger's perception. These indicators among any others were listed m the handbook of Airports Council International (ACI). Distinctive perceptions were observed among passengers with different travel motivations. This survey had been carried through in the airports of Brasilia, Porto Alegre, Salvador. Fortaleza, Curitiba and Bel6m. Considering this survey we can identified the most attractive airport among them. This work is a way to help improve quality of service, in particular, m these six airports of the Brazilian network. The results should be published and made available to all the parties concerned (airport authority, airlines and service providers) and should lead to corrective action when the passenger is not satisfied with the service.

  15. Color differences among feral pigeons (Columba livia) are not attributable to sequence variation in the coding region of the melanocortin-1 receptor gene (MC1R)

    Science.gov (United States)

    2013-01-01

    Background Genetic variation at the melanocortin-1 receptor (MC1R) gene is correlated with melanin color variation in many birds. Feral pigeons (Columba livia) show two major melanin-based colorations: a red coloration due to pheomelanic pigment and a black coloration due to eumelanic pigment. Furthermore, within each color type, feral pigeons display continuous variation in the amount of melanin pigment present in the feathers, with individuals varying from pure white to a full dark melanic color. Coloration is highly heritable and it has been suggested that it is under natural or sexual selection, or both. Our objective was to investigate whether MC1R allelic variants are associated with plumage color in feral pigeons. Findings We sequenced 888 bp of the coding sequence of MC1R among pigeons varying both in the type, eumelanin or pheomelanin, and the amount of melanin in their feathers. We detected 10 non-synonymous substitutions and 2 synonymous substitution but none of them were associated with a plumage type. It remains possible that non-synonymous substitutions that influence coloration are present in the short MC1R fragment that we did not sequence but this seems unlikely because we analyzed the entire functionally important region of the gene. Conclusions Our results show that color differences among feral pigeons are probably not attributable to amino acid variation at the MC1R locus. Therefore, variation in regulatory regions of MC1R or variation in other genes may be responsible for the color polymorphism of feral pigeons. PMID:23915680

  16. Human Factors Engineering in Designing the Passengers' Cockpit of the Malaysian Commercial Suborbital Spaceplane

    Science.gov (United States)

    Ridzuan Zakaria, Norul; Mettauer, Adrian; Abu, Jalaluddin; Hassan, Mohd Roshdi; Ismail, Anwar Taufeek; Othman, Jamaluddin; Shaari, Che Zhuhaida; Nasron, Nasri

    2010-09-01

    The design of the passengers’ cabin or cockpit of commercial suborbital spaceplane is a new and exciting frontier in human factors engineering, which emphasizes on comfort and safety. There is a program to develop small piloted 3 seats commercial suborbital spaceplane by a group of Malaysians with their foreign partners, and being relatively small and due to its design philosophy, the spaceplane does not require a cabin, but only a cockpit for its 2 passengers. In designing the cockpit, human factors engineering and safety principles are given priority. The cockpit is designed with the intention to provide comfort and satisfaction to the passengers without compromising the safety, in such a way that there are passenger-view wide angled video camera to observe the passengers at all time in flight, “rear-view”, “under-the-floor-view” and “fuselage-view” video cameras for the passengers, personalized gauges and LCDs on the dashboard to provide vital and useful information during the flight to the passengers, and biomedical engineered products which not only entertain the passengers, but also provide important information on the passengers to the ground crews who are responsible in the comfort and safety of the passengers. The passenger-view video-camera, which record the passengers with Earth visible through the glass canopy as the background, not only provides live visual of the passengers for safety reason, but also provide the most preferred memorable video collection for the passengers, while other video cameras provide the opportunity to view at various angles from unique positions to both the passengers and the ground observers. The gauges and LCDs on the dashboard provide access to the passengers to information such as the gravity, orientation, rate of climb and flight profile of the spaceplane, graphical presentation of the spaceplane in flight, and live video from the onboard video cameras. There is also a control stick for each passenger to

  17. Transfer to Intermediate Forms Following Concept Discrimination by Pigeons: Chimeras and Morphs

    Science.gov (United States)

    Ghosh, Natasha; Lea, S. E. G.; Noury, Malia

    2004-01-01

    Two experiments examined pigeons' generalization to intermediate forms following training of concept discriminations. In Experiment 1, the training stimuli were sets of images of dogs and cats, and the transfer stimuli were head/body chimeras, which humans tend to categorize more readily in terms of the head part rather than the body part. In…

  18. Stress and Fear Extinction

    Science.gov (United States)

    Maren, Stephen; Holmes, Andrew

    2016-01-01

    Stress has a critical role in the development and expression of many psychiatric disorders, and is a defining feature of posttraumatic stress disorder (PTSD). Stress also limits the efficacy of behavioral therapies aimed at limiting pathological fear, such as exposure therapy. Here we examine emerging evidence that stress impairs recovery from trauma by impairing fear extinction, a form of learning thought to underlie the suppression of trauma-related fear memories. We describe the major structural and functional abnormalities in brain regions that are particularly vulnerable to stress, including the amygdala, prefrontal cortex, and hippocampus, which may underlie stress-induced impairments in extinction. We also discuss some of the stress-induced neurochemical and molecular alterations in these brain regions that are associated with extinction deficits, and the potential for targeting these changes to prevent or reverse impaired extinction. A better understanding of the neurobiological basis of stress effects on extinction promises to yield novel approaches to improving therapeutic outcomes for PTSD and other anxiety and trauma-related disorders. PMID:26105142

  19. Temporal specificity of extinction in autoshaping.

    Science.gov (United States)

    Drew, Michael R; Yang, Cynthia; Ohyama, Tatsuya; Balsam, Peter D

    2004-07-01

    Three experiments investigated the effects of varying the conditioned stimulus (CS) duration between training and extinction. Ring doves (Streptopelia risoria) were autoshaped on a fixed CS-unconditioned stimulus (US) interval and extinguished with CS presentations that were longer, shorter, or the same as the training duration. During a subsequent test session, the training CS duration was reintroduced. Results suggest that the cessation of responding during an extinction session is controlled by generalization of excitation between the training and extinction CSs and by the number of nonreinforced CS presentations. Transfer of extinction to the training CS is controlled by the similarity between the extinction and training CSs. Extinction learning is temporally specific. (c) 2004 APA, all rights reserved

  20. 78 FR 51812 - Urbanized Area Formula Grants; Passenger Ferry Grant Program

    Science.gov (United States)

    2013-08-21

    ... authorized by the Moving Ahead for Progress in the 21st Century Act (MAP-21), Public Law 112- 141, July 6... accommodate walk-on passengers. 2. Eligible Projects Under this competitive program, eligible projects are... the number of trips (passengers and vehicles), the number of walk-on passengers, and transfers to...

  1. Organization of ascending auditory pathways in the pigeon (Columba livia) as determined by autoradiographic methods

    International Nuclear Information System (INIS)

    Correia, M.J.; Eden, A.R.; Westlund, K.N.; Coulter, J.D.

    1982-01-01

    A mixture of tritiated proline and fucose was injected into the labyrinthine endolymphatic space of 5 white king pigeons (Columba livia). Using standard autoradiographic techniques, the authors observed transsynaptic labeling in ascending auditory pathways to the level of the mesencephalon. Auditory system structures, ipsilateral to the injection site, which labeled heavily were the cochlear nerve, the magnocellular and angular nuclei, and the superior olive. Those ipsilateral structures which were slightly labeled were the lateral lemniscus and the dorsal part of the lateral mesencephalic nucleus. Contralateral structures which labeled were the superior olive, lateral lemniscus, and dorsal part of the lateral mesencephalic nucleus. The results of this study suggest that ascending auditory pathways (to the level of mesencephalon) in the pigeon are more similar to those described for mammals in general than previously thought. (Auth.)

  2. Organization of ascending auditory pathways in the pigeon (Columba livia) as determined by autoradiographic methods

    Energy Technology Data Exchange (ETDEWEB)

    Correia, M.J.; Eden, A.R.; Westlund, K.N.; Coulter, J.D. (Texas Univ., Galveston (USA). Medical Branch)

    1982-02-25

    A mixture of tritiated proline and fucose was injected into the labyrinthine endolymphatic space of 5 white king pigeons (Columba livia). Using standard autoradiographic techniques, the authors observed transsynaptic labeling in ascending auditory pathways to the level of the mesencephalon. Auditory system structures, ipsilateral to the injection site, which labeled heavily were the cochlear nerve, the magnocellular and angular nuclei, and the superior olive. Those ipsilateral structures which were slightly labeled were the lateral lemniscus and the dorsal part of the lateral mesencephalic nucleus. Contralateral structures which labeled were the superior olive, lateral lemniscus, and dorsal part of the lateral mesencephalic nucleus. The results of this study suggest that ascending auditory pathways (to the level of mesencephalon) in the pigeon are more similar to those described for mammals in general than previously thought.

  3. Thermal Transgressions and Phanerozoic Extinctions

    Science.gov (United States)

    Worsley, T. R.; Kidder, D. L.

    2007-12-01

    A number of significant Phanerozoic extinctions are associated with marine transgressions that were probably driven by rapid ocean warming. The conditions associated with what we call thermal transgressions are extremely stressful to life on Earth. The Earth system setting associated with end-Permian extinction exemplifies an end-member case of our model. The conditions favoring extreme warmth and sea-level increases driven by thermal expansion are also conducive to changes in ocean circulation that foster widespread anoxia and sulfidic subsurface ocean waters. Equable climates are characterized by reduced wind shear and weak surface ocean circulation. Late Permian and Early Triassic thermohaline circulation differs considerably from today's world, with minimal polar sinking and intensified mid-latitude sinking that delivers sulfate from shallow evaporative areas to deeper water where it is reduced to sulfide. Reduced nutrient input to oceans from land at many of the extinction intervals results from diminished silicate weathering and weakened delivery of iron via eolian dust. The falloff in iron-bearing dust leads to minimal nitrate production, weakening food webs and rendering faunas and floras more susceptible to extinction when stressed. Factors such as heat, anoxia, ocean acidification, hypercapnia, and hydrogen sulfide poisoning would significantly affect these biotas. Intervals of tectonic quiescence set up preconditions favoring extinctions. Reductions in chemical silicate weathering lead to carbon dioxide buildup, oxygen drawdown, nutrient depletion, wind and ocean current abatement, long-term global warming, and ocean acidification. The effects of extinction triggers such as large igneous provinces, bolide impacts, and episodes of sudden methane release are more potent against the backdrop of our proposed preconditions. Extinctions that have characteristics we call for in the thermal transgressions include the Early Cambrian Sinsk event, as well as

  4. Research on the compressive strength of a passenger vehicle roof

    Science.gov (United States)

    Zhao, Guanglei; Cao, Jianxiao; Liu, Tao; Yang, Na; Zhao, Hongguang

    2017-05-01

    To study the compressive strength of a passenger vehicle roof, this paper makes the simulation test on the static collapse of the passenger vehicle roof and analyzes the stress and deformation of the vehicle roof under pressure in accordance with the Roof Crush Resistance of Passenger Cars (GB26134-2010). It studies the optimization on the major stressed parts, pillar A, pillar B and the rail of roof, during the static collapse process of passenger vehicle roof. The result shows that the thickness of pillar A and the roof rail has significant influence on the compressive strength of the roof while that of pillar B has minor influence on the compressive strength of the roof.

  5. Trajectories of Late Permian – Jurassic radiolarian extinction rates: no evidence for an end-Triassic mass extinction

    Directory of Open Access Journals (Sweden)

    W. Kiessling

    2011-02-01

    Full Text Available The hypothesis that ocean acidification was a proximate trigger of the marine end-Triassic mass extinction rests on the assumption that taxa that strongly invest in the secretion of calcium-carbonate skeletons were significantly more affected by the crisis than other taxa. An argument against this hypothesis is the great extinction toll of radiolarians that has been reported from work on local sections. Radiolarians have siliceous tests and thus should be less affected by ocean acidification. We compiled taxonomically vetted occurrences of late Permian and Mesozoic radiolarians and analyzed extinction dynamics of radiolarian genera. Although extinction rates were high at the end of the Triassic, there is no evidence for a mass extinction in radiolarians but rather significantly higher background extinction in the Triassic than in the Jurassic. Although the causes for this decline in background extinction levels remain unclear, the lack of a major evolutionary response to the end-Triassic event, gives support for the hypothesis that ocean acidification was involved in the dramatic extinctions of many calcifying taxa. doi:10.1002/mmng.201000017

  6. Passenger and Cell Phone Conversations in Simulated Driving

    Science.gov (United States)

    Drews, Frank A.; Pasupathi, Monisha; Strayer, David L.

    2008-01-01

    This study examines how conversing with passengers in a vehicle differs from conversing on a cell phone while driving. We compared how well drivers were able to deal with the demands of driving when conversing on a cell phone, conversing with a passenger, and when driving without any distraction. In the conversation conditions, participants were…

  7. CFD Investigation on Long-Haul Passenger Bus

    Science.gov (United States)

    Tan, C. F.; Tee, B. T.; Law, H. C.; Lim, T. L.

    2015-09-01

    Air flow distribution is one of the important factors that will influence the bus passenger comfort during long haul travel. Poor air flow distribution not only cause discomfort to the bus passenger but also influence their travel mode as well. The main purpose of this study is to investigate the air flow performance of the bus air-conditioning system through CFD simulation approach. A 3D CAD model of air ducts was drawn and hence analysed by using CFD software, namely ANSYS Fluent, to determine the airflow rate for every outlets of the air-conditioning system. The simulated result was then validated with experimental data obtained from prototype model of air duct. Based on the findings, new design concepts is proposed with the aim to meet the industry requirement as well as to improve the bus passenger comfort during long haul travel.

  8. APPLICATION OF NFC TECHNOLOGY IN PASSENGER RAIL TRANSPORT

    Directory of Open Access Journals (Sweden)

    Henryk KOMSTA

    2016-09-01

    Full Text Available The article discusses the possibility of the application of the NFC technology as a system of selling tickets in passenger rail transport. The NFC (Near Field Communication technology is a wireless and contactless technology of transmission of radio data over short distances (max. 5 cm. This technology is very similar to the RFID (Radio Frequency Identification technology. It is assumed that this technology will spread rapidly and that already in 2015 around 85% of the payments in the EU will be made via mobile phones. This paper presents a research of passenger interest in this method of payment for tickets in the passenger rail transport in Slovakia. Further, an analysis of the applications of the NFC technology as a system of selling tickets in passenger rail transport, including the protection of data in mobile phones, the processes in case of losing a mobile phone and ensuring the communication between both parties was presented in the article. The last part of this analysis shows the possibility of purchasing tickets regardless of the carrier and the transport type.

  9. THE PROBLEMS OF PASSENGER TRANSPORTATIONS IN AN INTERNATIONAL COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Yu. S. Barash

    2010-05-01

    Full Text Available The basic aspects of international passenger transportations in Ukraine are represented. The analysis of present situation in these transportations is carried out. Some variants of solving the problems of passenger transportations in an international communication are considered.

  10. Integrating passenger and freight transportation : model formulation and insights

    NARCIS (Netherlands)

    Ghilas, V.; Demir, E.; Woensel, van T.

    2013-01-01

    Integrating passenger and freight ows creates attractive business opportunities because the same transportation needs can be met with fewer vehicles and emissions. This paper seeks an integrated solution for the transportation of passenger and freight simultaneously, so that fewer vehicles are

  11. Child Passenger Safety (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    Proper installation and use of car seats and booster seats for child passengers can save their lives. CDC recommends drivers ensure children are always buckled up. In this podcast, Bethany West discusses how to keep young passengers as safe as possible.

  12. Spatial-Temporal Similarity Correlation between Public Transit Passengers Using Smart Card Data

    Directory of Open Access Journals (Sweden)

    Hamed Faroqi

    2017-01-01

    Full Text Available The increasing availability of public transit smart card data has enabled several studies to focus on identifying passengers with similar spatial and/or temporal trip characteristics. However, this paper goes one step further by investigating the relationship between passengers’ spatial and temporal characteristics. For the first time, this paper investigates the correlation of the spatial similarity with the temporal similarity between public transit passengers by developing spatial similarity and temporal similarity measures for the public transit network with a novel passenger-based perspective. The perspective considers the passengers as agents who can make multiple trips in the network. The spatial similarity measure takes into account direction as well as the distance between the trips of the passengers. The temporal similarity measure considers both the boarding and alighting time in a continuous linear space. The spatial-temporal similarity correlation between passengers is analysed using histograms, Pearson correlation coefficients, and hexagonal binning. Also, relations between the spatial and temporal similarity values with the trip time and length are examined. The proposed methodology is implemented for four-day smart card data including 80,000 passengers in Brisbane, Australia. The results show a nonlinear spatial-temporal similarity correlation among the passengers.

  13. The Hybrid Airline Model. Generating Quality for Passengers

    Directory of Open Access Journals (Sweden)

    Bogdan AVRAM

    2017-12-01

    Full Text Available This research aims to investigate the different strategies adopted by the airline companies in adapting to the ongoing changes while developing products and services for passengers in order to increase their yield, load factor and passenger satisfaction. Finding a balance between costs and services quality in the airline industry is a crucial task for every airline wanting to gain a competitive advantage on the market. Also, the rise of the hybrid business operating model has brought up many challenges for airlines as the line between legacy carriers and low-cost carriers is getting thinner in terms of costs and innovative ideas to create a superior product for the passengers.

  14. Bus-stop Based Real Time Passenger Information System - Case Study Maribor

    Science.gov (United States)

    Čelan, Marko; Klemenčič, Mitja; Mrgole, Anamarija L.; Lep, Marjan

    2017-10-01

    Real time passenger information system is one of the key element of promoting public transport. For the successful implementation of real time passenger information systems, various components should be considered, such as: passenger needs and requirements, stakeholder involvement, technological solution for tracking, data transfer, etc. This article carrying out designing and evaluation of real time passenger information (RTPI) in the city of Maribor. The design phase included development of methodology for selection of appropriate macro and micro location of the real-time panel, development of a real-time passenger algorithm, definition of a technical specification, financial issues and time frame. The evaluation shows that different people have different requirements; therefore, the system should be adaptable to be used by various types of people, according to the age, the purpose of journey, experience of using public transport, etc. The average difference between perceived waiting time for a bus is 35% higher than the actual waiting time and grow with the headway increase. Experiences from Maribor have shown that the reliability of real time passenger system (from technical point of view) must be close to 100%, otherwise the system may have negative impact on passengers and may discourage the use of public transport. Among considered events of arrivals during the test period, 92% of all prediction were accurate. The cost benefit analysis has focused only on potential benefits from reduced perceived users waiting time and foreseen costs of real time information system in Maribor for 10 years’ period. Analysis shows that the optimal number for implementing real time passenger information system at the bus stops in Maribor is set on 83 bus stops (approx. 20 %) with the highest number of passenger. If we consider all entries at the chosen bus stops, the total perceived waiting time on yearly level could be decreased by about 60,000 hours.

  15. Cultivar preference and sensory evaluation of vegetable pigeon pea (Cajanus cajan) in Eastern Kenya

    Science.gov (United States)

    Preference and acceptability of twelve vegetable pigeon pea genotypes of medium maturity was evaluated in Eastern Kenya based on six seed cultivar parameters of color, appearance, taste, odor, tenderness and overall seed acceptability. The sensory characteristics were scored by consumers and farmers...

  16. Passenger car fuel consumption survey

    Energy Technology Data Exchange (ETDEWEB)

    1984-03-01

    This survey originated from a proposal to monitor the fuel consumption and fuel economy of personal use passenger cars operated in Canada. Its purpose is to establish a data base which would contain information on total distance travelled, total amount of fuel consumed, average distance obtained per unit of fuel, total expenditures on fuel, and seasonal fluctuations in fuel consumption and in distance travelled. Among the needs served by this data base are the monitoring of passenger car fuel economy standards and the estimation of pasenger car fuel requirements in conditions involving fuel shortages. Survey methodology is by telephone interview to trace selected vehicles to the registered owners, at which time a fuel purchase diary is then mailed to the principal driver of the car. The results are tabulated on a quarterly basis and to be released as they become available in bulletins similar to this. Data are presented for each province and the total for Canada is given. During the fourth quarter of 1982, it is estimated that there were 7.3 million personal use passenger cars operated in Canada. These cars were driven 28 billion kilometers and consumed 4.3 billion litres of fuel. Their average litres/100 kilometres and the average fuel consumption was 590 litres. 8 tabs.

  17. Crop milk protein is synthesised following activation of the IRS1/Akt/TOR signalling pathway in the domestic pigeon (Columba livia).

    Science.gov (United States)

    Hu, X-C; Gao, C-Q; Wang, X-H; Yan, H-C; Chen, Z-S; Wang, X-Q

    2016-12-01

    The experiment was conducted to study whether insulin receptor substance 1 (IRS1) / Protein kinase B (Akt)/target of the rapamycin (TOR) signalling pathway activation stimulates crop milk protein synthesis in the domestic pigeon (Columba livia). Crop milk was collected from ten 1-d-old squabs and analysed for nutrient content. During the non-breeding period and the first day of lactation, blood samples were collected from 5 pairs of breeding pigeons and the levels of prolactin and insulin were determined. Crop samples were collected from 5 pairs of breeders at d 14 and 16 of the incubation period and d 1, 3 and 7 of the lactation period. Crop samples were evaluated for changes in crop weight and thickness and changes in the expression patterns of IRS1/Akt/TOR signalling pathway-related proteins. The results demonstrated that prolactin induces a gradual increase in the relative weight and thickness of the crop, with crops reaching a maximum size at the third day of lactation. Pigeon crop milk contains 64.1% crude protein and 29.7% crude fat based on dry weight. Serum prolactin and insulin levels in the lactation period were significantly higher than those in the non-breeding period. Compared with non-breeding pigeons, the expression of the phosphorylated IRS1 phosphorylated Akt, phosphorylated TOR, phosphorylated ribosomal protein S6 kinase, phosphorylated S6, phosphorylated eukaryotic initiation factor 4E binding protein 1 and eukaryotic initiation factor 4E were significantly up-regulated in the crop of pigeons in the lactation period. In conclusion, prolactin might induce changes in crop tissue and form the physiological structure for crop milk synthesis. Furthermore, the synthesis of crop milk protein is regulated by activation of the IRS1/Akt/TOR signalling pathway.

  18. Prevalence of ectoparasites in free-range backyard chickens, domestic pigeons (Columba livia domestica) and turkeys of Kermanshah province, west of Iran.

    Science.gov (United States)

    Rezaei, Farid; Hashemnia, Mohammad; Chalechale, Abdolali; Seidi, Shahin; Gholizadeh, Maryam

    2016-06-01

    This study was carried out on free-range backyard chickens, domestic pigeons (Columba livia domestica) and turkeys from May 2012 to April 2013 to determine the prevalence and identify the species of ectoparasites in Kermanshah province, west of Iran. Of the total of 600 free-range backyard chickens (185 ♂ and 415 ♀), 700 domestic pigeons (278 ♂ and 422 ♀) and 150 turkeys (53 ♂ and 97 ♀), 389 (64.83 %), 608 (86.85 %) and 54 (36 %) were infected with one or more parasites respectively. Eleven ectoparasites species including five of lice (50.16 % Menacanthus stramineus, 13.66 % Menopon gallinae, 4.83 % Cuclotogaster heterographus, 5.16 % Goniocotes gallinae, 2.33 % Goniodes gigas), three of mites (26.33 % Dermanyssus gallinae, 8.5 % Ornithonyssus bursa, 7 % Cnemidocoptes mutans), one of tick (78.66 % Argas persicus) and two of flea (12.33 % Echidnophaga gallinacea, 2 % Pulex irritans) were found in the backyard chickens. The domestic pigeons were infected with six species of parasites including: Columbicola columbae (61.7 %), M. gallinae (10.43 %), M. stramineus (9 %), D. gallinae (8.28 %), Argas reflexus (74.14 %) and Pseudolynchia canariensis (27.7 %). The ectoparasites species recorded in turkeys were M. gallinae (14 %), M. stramineus (8 %), D. gallinae (12.66 %), C. mutans (6 %), A. persicus (24.66 %) and E. gallinacean (6 %). This is the first survey to determine the prevalence and identify the species of ectoparasites among free-range backyard chicken, domestic pigeons and turkeys in Kermanshah province. The high prevalence rate of ectoparasites in free-range backyard chickens and domestic pigeons indicates that parasitic infection is a common problem in this area.

  19. Constraints on Enhanced Extinction Resulting from Extinction Treatment in the Presence of an Added Excitor

    Science.gov (United States)

    Urcelay, Gonzalo P.; Lipatova, Olga; Miller, Ralph R.

    2009-01-01

    Three Pavlovian fear conditioning experiments with rats as subjects explored the effect of extinction in the presence of a concurrent excitor. Our aim was to explore this particular treatment, documented in previous studies to deepen extinction, with novel control groups to shed light on the processes involved in extinction. Relative to subjects…

  20. Pigeons trade efficiency for stability in response to level of challenge during confined flight.

    Science.gov (United States)

    Williams, C David; Biewener, Andrew A

    2015-03-17

    Individuals traversing challenging obstacles are faced with a decision: they can adopt traversal strategies that minimally disrupt their normal locomotion patterns or they can adopt strategies that substantially alter their gait, conferring new advantages and disadvantages. We flew pigeons (Columba livia) through an array of vertical obstacles in a flight arena, presenting them with this choice. The pigeons selected either a strategy involving only a slight pause in the normal wing beat cycle, or a wings-folded posture granting reduced efficiency but greater stability should a misjudgment lead to collision. The more stable but less efficient flight strategy was not used to traverse easy obstacles with wide gaps for passage but came to dominate the postures used as obstacle challenge increased with narrower gaps and there was a greater chance of a collision. These results indicate that birds weigh potential obstacle negotiation strategies and estimate task difficulty during locomotor pattern selection.