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causes of high blood o2 affinity of animals living at high altitude.we have measured the partial pressure of o2 at 50% saturation (p50) and the concentration of various phosphate compounds in the erythrocytes of the bar-headed goose and the guanaco to establish the cause of the high blood o2 affinity in animals who normally reside at high altitude. the same data were obtained in the blood of two goose species, that live at sea level, and in human blood. at standard conditions (ph 7.4, pco2 40 torr, 37 degrees c), p50 was 29.7 torr in the blood of the bar-headed ...197714096
[the primary structure of the hemoglobin of the greylag goose (answer anser) and the unequal evolution of the beta-chains (an experimental approach to a biochemical analysis of behaviour (author's transl)].the primary structures of the alpha- and beta-chains from greylag goose (anser anser) hemoglobin are given. the sequence was deduced automatically in the sequenator. they differ from chicken alpha-chains in the exchange of 30, from beta-chains in the exchange of only 8 amino acid residues, respectively. the contact points of inositol pentaphosphate with the beta-chains are identical in chicken and greylag goose. unequal evolution of the beta-chains was found, which is published here for the firs ...1979468112
environment-dependent attachment behaviour of goslings (anser indicus) due to environment-specific separation experience.hand-reared bar-headed goslings (anser indicus) were always left alone by the human parent in one room, while in another room the parent was always with them. after 13--22 h of experience in each room and at an age of 4--5 days individual goslings were left alone for 5 min in each room. they uttered significantly fewer distress calls in the room in which they were accustomed to being left alone by the parent. the result is interpreted in terms of environment-dependent calibration of interindivid ...1977888582
adaptation of bird hemoglobins to high altitudes: demonstration of molecular mechanism by protein engineering.of two closely related species of geese, one, the greylag goose, lives in the indian plains all year round, while the other, the bar-headed goose, lives at the tibetan lakes and migrates across the himalayas to winter in india. another species, the andean goose, lives in the high andes all year round. possession of a hb with high oxygen affinity helps to adapt bar-headed and andean geese to high altitudes. the hb amino acid sequences of the bar-headed and the greylag geese differ by four substit ...19911862080
the primary structures of the major and minor hemoglobin-components of adult andean goose (chloephaga melanoptera, anatidae): the mutation leu----ser in position 55 of the beta-chains.the primary structures of the hemoglobin components hb a and hb d of the adult andean goose (chloephaga melanoptera) are presented. the globin chains were separated on cm-cellulose in 8m urea buffer. the amino-acid sequences were established by automatic edman degradation of the globin chains and of the tryptic peptides in liquid- and gas-phase sequenators. the sequences are aligned with those of greylag goose (anser anser) as a biological reference and other sequences of birds. a detailed evalu ...19873442599
high-altitude respiration of birds. the primary structures of the alpha d-chains of the bar-headed goose (anser indicus), the greylag goose(anser anser) and the canada goose (branta canadensis).the primary structures of the alpha d-chains of the minor component hb d of anser indicus, anser anser and branta canadensis are presented. following chain separation by rp-hplc, the amino-acid sequences were established by automatic edman degradation of the globin chains and the tryptic peptides. the three chains show a high degree of homology. for the high altitude respiration the alpha 1 beta 1 interface at position alpha 119 is important. for the bar-headed goose a mechanism for high altitud ...19863755960
blood flow distribution during hypocapnic hypoxia in pekin ducks and bar-headed geese.the purpose of this study was to determine the effects of hypocapnic hypoxia on regional blood flow in birds. regional blood flow was measured using the radioactive microsphere method in unanesthetized pekin ducks (anas platyrhynchos) and bar-headed geese (anser indicus) breathing 21, 10 and 5% o2. in both birds, arterial po2 was reduced from about 96 torr during normoxia to about 28 torr during severe hypoxia. severe hypocapnic hypoxia produced a change in the pattern of blood flow in ducks; bl ...19853929351
attenuated pulmonary pressor response to hypoxia in bar-headed geese.we determined the pulmonary pressor response during hypoxia in bar-headed geese (anser indicus), a species that flies at altitudes up to 9,000 m, and pekin ducks (anas platyrhynchos), a non-flyer. mean pulmonary arterial blood pressure (pap) and arterial o2 partial pressure (pao2) were measured in unanesthetized birds acutely exposed to 21, 10, 5, and, in geese only, 4% o2. pap in geese did not change as pao2 was reduced from 95 to 46 torr and rose only 3 mmhg when pao2 was reduced to 28 torr. t ...19846465351
oxygen delivery to the heart and brain during hypoxia: pekin duck vs. bar-headed goose.to investigate mechanisms that may allow birds to tolerate extreme high altitude, we acutely exposed unanesthetized bar-headed geese (anser indicus) and pekin ducks (anas platyrhynchos) to 0.21, 0.10, and 0.05 inspired fractional concentrations of o2 (fio2). in both birds, arterial o2 partial pressure (pao2) was about 95 torr at 0.21 fio2, 45 torr at 0.10 fio2, and 28 torr at 0.05 fio2. hyperventilation occurred at both levels of hypoxia, with paco2 decreasing to about 7 torr at 28 torr pao2. at ...19846742237
[hemoglobins, xlvii. hemoglobins of the bar-headed goose (anser indicus): primary structure and physiology of respiration, systematic and evolution].the primary structures of the alpha- and beta-chains of the main component of bar-headed goose (anser indicus) are given. by homologous comparison with the hemoglobin of the grey-lag goose (anser anser) 3 differences were found in the alpha-chains, 1 difference in the beta-chains. in position alpha 119 h2ala and beta 125 h3asp alpha 1 beta 2-contact points are changed. the mutation alpha 63 e12val brings a drastic change in tertiary structure of the alpha-chains of bar-headed goose: the helices ...19827106705
oxygen transport during progressive hypoxia in high-altitude and sea-level waterfowl.under conditions of progressive hypoxia, oxygen transport was compared in bar-headed geese (anser indicus), a species which breeds on the tibetan plateau and migrates at altitudes up to 9200 m, and pekin ducks (anas platyrhynchos, forma domestica), a similarly sized, sea-level water fowl that does not fly. pekin ducks showed no altitude-induced behavioral effects (e.g., restlessness) up to 7620 m, while bar-headed geese tolerated 10,668 m with no observable behavioral changes. ventilatory and c ...19807375742
[the sequence of the hemoglobin of barheaded goose (anser indicus) and ostrich (struthio camelus). inositol pentaphosphate as a modulator of the evolution rate: the surprising sequence alpha 63 (e12) valine (author's transl)]. 19807399417
metabolic and ventilatory adjustments and tolerance of the bat pteropus poliocephalus to acute hypoxic stress.we have investigated the maximum tolerance and the ventilatory responses of a bat, p. poliocephalus (pp), to normobaric hypoxic stress. pp can tolerate inspired po2s (pio2) down to 30 torr. this bat is one of the most hypoxia-tolerant non-hibernating species of mammals known, and has a tolerance which lies within the range of pio2s reported for different birds. unlike most mammals in its size range, pp maintains its normoxic oxygen consumption rate even in deep hypoxia. the maximum hypoxic venti ...19957553335
the crystal structure of a high oxygen affinity species of haemoglobin (bar-headed goose haemoglobin in the oxy form).we have determined the crystal structure of bar-headed goose haemoglobin in the oxy form to a resolution of 2.0 a. the r-factor of the model is 19.8%. the structure is similar to human hba, but contacts between the subunits show slightly altered packing of the tetramer. bar-headed goose blood shows a greatly elevated oxygen affinity compared to closely related species of geese. this is apparently due to a single proline to alanine mutation at the alpha 1 beta 1 interface which destabilises the t ...19968568892
[helminth fauna anseriformes (aves) in the lodz zoological garden].in the years 1959-1990 429 birds on 30 species of anseriformes were examined post mortem at zoo lódź. the helminths were found in 108 birds (25.17%) of 19 species. in infected birds there were found 4 species of trematodes: one of them, catatropis verrucosa is in poland new for cygnus olor; 9 species of cestodes--7 of them are in poland new for examined hosts; namely: drepanidotaenia lanceolata for dendrocygna viduata, cygnus atratus, branta bernicla, and anas platyrhynchos; microsomacanthus par ...19979424942
avian haemoglobins and structural basis of high affinity for oxygen: structure of bar-headed goose aquomet haemoglobin.haemoglobin from the bar-headed goose (anser indicus) has higher oxygen affinity than that from its lowland relatives such as greylag goose (a. anser). the crystal structure of bar-headed goose aquomet haemoglobin was determined at 2.3 a resolution and compared with the structures of the goose oxy, human, horse and other avian haemoglobins and the sequences of other avian haemoglobins. four amino-acid residues differ between greylag goose and bar-headed goose haemoglobins, among which alaalpha11 ...200111375496
the crystal structure of bar-headed goose hemoglobin in deoxy form: the allosteric mechanism of a hemoglobin species with high oxygen affinity.the crystal structure of a high oxygen affinity species of hemoglobin, bar-headed goose hemoglobin in deoxy form, has been determined to a resolution of 2.8 a. the r and r(free) factor of the model are 0.197 and 0.243, respectively. the structure reported here is a special deoxy state of hemoglobin and indicates the differences in allosteric mechanisms between the goose and human hemoglobins. the quaternary structure of the goose deoxy hemoglobin shows obvious differences from that of human deox ...200111601851
the structure of greylag goose oxy haemoglobin: the roles of four mutations compared with bar-headed goose haemoglobin.the greylag goose (anser anser), which lives on lowlands and cannot tolerate hypoxic conditions, presents a striking contrast to its close relative the bar-headed goose (a. indicus), which lives at high altitude and possesses high-altitude hypoxia adaptation. there are only four amino-acid residue differences at alpha18, alpha63, alpha119 and beta125 between the haemoglobins of the two species. the crystal structure of greylag goose oxy haemoglobin was determined at 3.09 a resolution. its quater ...200111717498
molecular basis of bird respiration: primary hemoglobin structure component from tufted duck (aythya fuligula, anseriformes)--role of alpha99arg in formation of a complex salt bridge network.the primary structure of the major hemoglobin component, hba (alpha(a)- and beta-chain), from tufted duck (aythya fuligula) is presented. the separation of the globin subunits was achieved by ion exchange chromatography on cm-cellulose in 8 m urea. the amino acid sequence was determined by automatic edman degradation of native chains as well as tryptic and hydrolytic peptides in a gas-phase sequencer. the automated homology model was generated by the protein structure modeling package what if us ...200211829480
[isolation of influenza a/h5n1 virus strains from poultry and wild birds in west siberia during epizooty (july 2005) and their depositing to the state collection of viruses (august 8, 2005)].six strains of influenza ah5n1 virus were isolated, by using ps and mdck continuous cell lines from poultry and wild birds, which were collected on july 28, 2005 in the samples taken from 5 examines species of wild birds in the novosibirsk region during the epizootic outbreak with a high mortality. the strains were identified by means of hit, rt-pcr, and microchip-based techniques. two strains, a/grebe/novosibirsk/29/05 (h5n1) and a/duck/novosibirsk/56/05 (h5n1), were deposited to the russian st ...200616515035
seroprevalance and identification of influenza a virus infection from migratory wild waterfowl in china (2004-2005).outbreaks of a highly pathogenic avian influenza (h5n1) were reported in birds in more than eight asian countries. we sought to identify the origin of this infection, and herein report the results of serological and virological monitoring of migrant wild waterfowl in mainland china. from a total of 493 serum samples, collected from 15 migratory wild waterfowl species for 9 months (from june 2004 to may 2005) in mainland china, we detected only low-level antibodies against influenza subtypes h2, ...200616629983
properties and dissemination of h5n1 viruses isolated during an influenza outbreak in migratory waterfowl in western china.h5n1 influenza a viruses are widely distributed among poultry in asia, but until recently, only a limited number of wild birds were affected. during late april through june 2005, an outbreak of h5n1 virus infection occurred among wild birds at qinghai lake in china. here, we describe the features of this outbreak. first identified in bar-headed geese, the disease soon spread to other avian species populating the lake. sequence analysis of 15 viruses representing six avian species and collected a ...200616731936
characterization of a highly pathogenic h5n1 influenza virus derived from bar-headed geese in china.influenza a viruses are usually non-pathogenic in wild aquatic birds, their natural reservoir. however, from may to july 2005, at qinghai lake in china, an unprecedented outbreak of highly pathogenic h5n1 avian influenza virus caused the death of thousands of wild migratory waterbirds. herein, h5n1 influenza virus from bar-headed geese collected during the outbreak was characterized. genomic analysis showed that a/bar-headed goose/qinghai/0510/05 (bh h5n1 virus) is a reassortant virus. amino aci ...200616760384
newcastle disease virus-based live attenuated vaccine completely protects chickens and mice from lethal challenge of homologous and heterologous h5n1 avian influenza viruses.h5n1 highly pathogenic avian influenza virus (hpaiv) has continued to spread and poses a significant threat to both animal and human health. current influenza vaccine strategies have limitations that prevent their effective use for widespread inoculation of animals in the field. vaccine strains of newcastle disease virus (ndv), however, have been used successfully to easily vaccinate large numbers of animals. in this study, we used reverse genetics to construct a ndv that expressed an h5 subtype ...200717050610
the role of hemoglobin oxygen affinity in oxygen transport at high altitude.hemoglobin is involved in the regulation of o(2) transport in two ways: a long-term adjustment in red cell mass is mediated by erythropoietin (epo), a response to renal oxgyenation. short-term, rapid-response adjustments are mediated by ventilation, cardiac output, hemoglobin oxygen affinity (p50), barriers to o(2) diffusion, and the control of local microvascular tissue perfusion. the distribution of o(2) between dissolved (po2) and hemoglobin-bound (saturation) is the familiar oxygen equilibri ...200717449336
control of breathing and adaptation to high altitude in the bar-headed goose.the bar-headed goose flies over the himalayan mountains on its migratory route between south and central asia, reaching altitudes of up to 9,000 m. we compared control of breathing in this species with that of low-altitude waterfowl by exposing birds to step decreases in inspired o(2) under both poikilocapnic and isocapnic conditions. bar-headed geese breathed substantially more than both greylag geese and pekin ducks during severe environmental (poikilocapnic) hypoxia (5% inspired o(2)). this w ...200717491113
highly pathogenic avian influenza virus (h5n1) in domestic poultry and relationship with migratory birds, south korea.during the 2006-2007 winter season in south korea, several outbreaks of highly pathogenic avian influenza virus (h5n1) were confirmed among domestic poultry and in migratory bird habitats. phylogenetic analysis showed that all isolates were closely related and that all belong to the a/bar-headed goose/qinghai/5/2005-like lineage rather than the a/chicken/korea/es/2003-like lineage.200818325269
body temperature depression and peripheral heat loss accompany the metabolic and ventilatory responses to hypoxia in low and high altitude birds.the objectives of this study were to compare the thermoregulatory, metabolic and ventilatory responses to hypoxia of the high altitude bar-headed goose with low altitude waterfowl. all birds were found to reduce body temperature (t(b)) during hypoxia, by up to 1-1.5 degrees c in severe hypoxia. during prolonged hypoxia, t(b) stabilized at a new lower temperature. a regulated increase in heat loss contributed to t(b) depression as reflected by increases in bill surface temperatures (up to 5 degre ...200818375857
a survey on the faunal diversity of savar upazila, dhaka, bangladesh.a survey was conducted during january to december 2006 to assess the status of faunal diversity of savar upazila, dhaka, bangladesh. a total of 30 species of birds, 24 species of winter birds, 7 species of reptiles, 3 species of amphibians, 15 species of mammalians and 32 species of fishes were recorded. relative abundance of those species were determined. of the birds, house sparrow (passer domesticus) was abundant while blyth's kingfisher (alcedo hercules), rock eagle owl (bubo bengalensis), h ...200818817158
immunogenicity of hemagglutinin from a/bar-headed goose/qinghai/1a/05 and a/anhui/1/05 strains of h5n1 influenza viruses produced in nicotiana benthamiana plants.highly pathogenic avian influenza (hpai) viruses of the h5n1 subtype have been identified as a potential pandemic threat by the world health organization (who). since 1997, these viruses have been spreading from asia to europe and africa with increasing genetic and antigenic diversities. vaccination is the preferred strategy for the prevention and control of influenza infections and the availability of a system for the rapid engineering and production of vaccines is required in the event of an i ...200919200814
effect of hemolysis on plasma protein levels and plasma electrophoresis in birds.protein electrophoresis is recognized as a reliable diagnostic tool for birds even though results are seldom pathognomonic. unfortunately, this technique is underused in avian medicine because many factors interfere with electrophoresis patterns; hemolysis is one of these factors and is often associated with improper specimen handling. in human laboratory medicine, hemolysis is a known interference factor that can lead to erroneous results. published data on the influence of hemolysis on protein ...200919204337
immunogenicity and protective efficacy of a live attenuated h5n1 vaccine in nonhuman primates.the continued spread of highly pathogenic h5n1 influenza viruses among poultry and wild birds, together with the emergence of drug-resistant variants and the possibility of human-to-human transmission, has spurred attempts to develop an effective vaccine. inactivated subvirion or whole-virion h5n1 vaccines have shown promising immunogenicity in clinical trials, but their ability to elicit protective immunity in unprimed human populations remains unknown. a cold-adapted, live attenuated vaccine w ...200919412338
evolution of muscle phenotype for extreme high altitude flight in the bar-headed goose.bar-headed geese migrate over the himalayas at up to 9000 m elevation, but it is unclear how they sustain the high metabolic rates needed for flight in the severe hypoxia at these altitudes. to better understand the basis for this physiological feat, we compared the flight muscle phenotype of bar-headed geese with that of low altitude birds (barnacle geese, pink-footed geese, greylag geese and mallard ducks). bar-headed goose muscle had a higher proportion of oxidative fibres. this increased mus ...200919640884
parallel evolution in the major haemoglobin genes of eight species of andean waterfowl.theory predicts that parallel evolution should be common when the number of beneficial mutations is limited by selective constraints on protein structure. however, confirmation is scarce in natural populations. here we studied the major haemoglobin genes of eight andean duck lineages and compared them to 115 other waterfowl species, including the bar-headed goose (anser indicus) and abyssinian blue-winged goose (cyanochen cyanopterus), two additional species living at high altitude. one to five ...200919754505
characterization of low pathogenicity avian influenza viruses isolated from wild birds in mongolia 2005 through 2007.since the emergence of h5n1 high pathogenicity (hp) avian influenza virus (aiv) in asia, numerous efforts worldwide have focused on elucidating the relative roles of wild birds and domestic poultry movement in virus dissemination. in accordance with this a surveillance program for aiv in wild birds was conducted in mongolia from 2005-2007. an important feature of mongolia is that there is little domestic poultry production in the country, therefore aiv detection in wild birds would not likely be ...200919891786
identification of amino acids in ha and pb2 critical for the transmission of h5n1 avian influenza viruses in a mammalian host.since 2003, h5n1 influenza viruses have caused over 400 known cases of human infection with a mortality rate greater than 60%. most of these cases resulted from direct contact with virus-contaminated poultry or poultry products. although only limited human-to-human transmission has been reported to date, it is feared that efficient human-to-human transmission of h5n1 viruses has the potential to cause a pandemic of disastrous proportions. the genetic basis for h5n1 viral transmission among human ...200920041223
spatial dynamics of bar-headed geese migration in the context of h5n1.virulent outbreaks of highly pathogenic avian influenza (hpai) since 2005 have raised the question about the roles of migratory and wild birds in the transmission of hpai. despite increased monitoring, the role of wild waterfowl as the primary source of the highly pathogenic h5n1 has not been clearly established. the impact of outbreaks of hpai among species of wild birds which are already endangered can nevertheless have devastating consequences for the local and non-local ecology where migrato ...201020472636
protective efficacy of the h5 inactivated vaccine against different highly pathogenic h5n1 avian influenza viruses isolated in china and vietnam.an inactivated h5n1 avian influenza (ai) vaccine generated by reverse genetics and containing the hemagglutinin and neuraminidase genes of the h5n1 a/goose/guangdong/1/96 (gs/gd/06) virus has been used in domestic poultry in china and vietnam as an important control strategy for h5n1 ai. the efficacy of this vaccine against early h5n1 isolates has been fully evaluated in chicken, ducks, and geese. however, there are no reports about its efficacy against h5n1 viruses recently isolated in china an ...201020521646
dogs are highly susceptible to h5n1 avian influenza virus.replication of avian influenza viruses (aivs) in dogs may facilitate their adaptation in humans; however, the data to date on h5n1 influenza virus infection in dogs are conflicting. to elucidate the susceptibility of dogs to this pathogen, we infected two groups of 6 beagles with 10(6) 50% egg-infectious dose of h5n1 aiv a/bar-headed goose/qinghai/3/05 (bhg/qh/3/05) intranasally (i.n.) and intratracheally (i.t.), respectively. the dogs showed disease symptoms, including anorexia, fever, conjunct ...201020580396
captive rearing and release of bar-headed geese (anser indicus) in china: a possible hpai h5n1 virus infection route to wild birds. 201020966292
flying over an infected landscape: distribution of highly pathogenic avian influenza h5n1 risk in south asia and satellite tracking of wild waterfowl.highly pathogenic avian influenza (hpai) h5n1 virus persists in asia, posing a threat to poultry, wild birds, and humans. previous work in southeast asia demonstrated that hpai h5n1 risk is related to domestic ducks and people. other studies discussed the role of migratory birds in the long distance spread of hpai h5n1. however, the interplay between local persistence and long-distance dispersal has never been studied. we expand previous geospatial risk analysis to include south and southeast as ...201121267626
wild bird migration across the qinghai-tibetan plateau: a transmission route for highly pathogenic h5n1.qinghai lake in central china has been at the center of debate on whether wild birds play a role in circulation of highly pathogenic avian influenza virus h5n1. in 2005, an unprecedented epizootic at qinghai lake killed more than 6000 migratory birds including over 3000 bar-headed geese (anser indicus). h5n1 subsequently spread to europe and africa, and in following years has re-emerged in wild birds along the central asia flyway several times.201121408010
side-necked turtle (pleurodira, chelonia, reptilia) hemoglobin: cdna-derived primary structures and x-ray crystal structures of hb a.red blood cells of yellow-spotted river turtles (podocnemis unifilis, pleurodira, chelonia, reptilia) have two hemoglobin (hb) components, hb a and hb d. we purified the hemoglobin component homologous to amniote (reptiles, birds, and mammals) adult hb a which comprises two identical a(a) -globin polypeptides and two identical ß-globin polypeptides. to establish the crystal structure of podocnemis hb a, we first determined the globin primary structures using cdna nucleotide sequencing with the a ...201121445850
differences in the priming effect of various clades/subclades of inactivated h5n1 vaccine for booster injection with heterologous clades of vaccine strains.the prime-boost response induced by different combinations of four h5n1 vaccines (nibrg-14 (clade 1), indo05/2005(h5n1)/pr8-ibcdc-rg2 (clade 2.1), a/bar-headed goose/qinhai lake/1a/05 sj163222 (clade 2.2), and anhui01/2005(h5n1)-pr8-ibcdc-rg5 (clade 2.3.4)) was evaluated in mice. clade 1-primed balb/c mice showed a booster response to all of the other three h5n1 vaccines. clade 2.2 vaccine was also a good priming vaccine. however, mice primed with clade 2.1 or clade 2.3.4 vaccine did not respond ...201121497637
structure of greyhound hemoglobin: origin of high oxygen affinity.this study presents the crystal structure of greyhound hemoglobin (grhb) determined to 1.9 å resolution. grhb was found to crystallize with an α(1)β(1) dimer in the asymmetric unit and belongs to the r2 state. oxygen-affinity measurements combined with the fact that grhb crystallizes in the r2 state despite the high-salt conditions used for crystallization strongly indicate that grhb can serve as a model high-oxygen-affinity hemoglobin (hb) for higher mammals, especially humans. structural analy ...201121543841
mhc class i loci of the bar-headed goose (anser indicus).mhc class i proteins mediate functions in anti-pathogen defense. mhc diversity has already been investigated by many studies in model avian species, but here we chose the bar-headed goose, a worldwide migrant bird, as a non-model avian species. sequences from exons encoding the peptide-binding region (pbr) of mhc class i molecules were isolated from liver genomic dna, to investigate variation in these genes. these are the first mhc class i partial sequences of the bar-headed goose to be reported ...201021637434
rapid generation of pandemic influenza virus vaccine candidate strains using synthetic dna.please cite this paper as: verity et al. (2011) rapid generation of pandemic influenza virus vaccine candidate strains using synthetic dna. influenza and other respiratory viruses doi:10.1111/j.1750-2659.2011.00273.x. background vaccination is considered the most effective means of reducing influenza burden. the emergence of h5n1 and pandemic spread of novel h1n1/2009 viruses reinforces the need to have strategies in place to rapidly develop seed viruses for vaccine manufacture. methods candid ...201121771285
characterisation of a highly pathogenic h5n1 clade 2.3.2 influenza virus isolated from swans in shanghai, china.in spring 2009, one strain of h5n1 clade 2.3.2 virus was isolated from wild swans in shanghai, indicating the importance of the wild swan in the ecology of this highly pathogenic avian influenza virus (hpaiv) in eastern china. pathogenicity experiments conducted in this study indicated that the virus was highly pathogenic for chickens but lowly pathogenic for mammalian hosts, as evidenced by reduced infection of mice. the analysis of complete genome sequences and genetic evolution showed that a/ ...201121904849
genetic and environmental influences on gas exchange.gas exchange is a critical process required for sufficient tissue perfusion. the environment, genetics, or a combination of the two can affect this process. various strategies have evolved to overcome the specific gas exchange challenges in different environments and it is clear that some genes are pivotal to the development of gas exchanging organs (e.g. bmp4). lower partial pressure of oxygen (hypoxia), reducing the partial pressure gradient, makes gas exchange more challenging and therefore t ...201223720259
stable isotopes suggest low site fidelity in bar-headed geese (anser indicus) in mongolia: implications for disease transmission.population connectivity is an important consideration in studies of disease transmission and biological conservation, especially with regard to migratory species. determining how and when different subpopulations intermingle during different phases of the annual cycle can help identify important geographical regions or features as targets for conservation efforts and can help inform our understanding of continental-scale disease transmission. in this study, stable isotopes of hydrogen and carbon ...027695389
draft genome sequence of bacillus megaterium bhg1.1, a strain isolated from bar-headed goose (anser indicus) feces on the qinghai-tibet plateau.bacillus megaterium is a soil-inhabiting gram-positive bacterium that is routinely used in industrial applications for recombinant protein production and bioremediation. studies involving bacillus megaterium isolated from waterfowl are scarce. here, we report a 6.26-mbp draft genome sequence of bacillus megaterium bhg1.1, which was isolated from feces of a bar-headed goose.201627174262
a replicating modified vaccinia tiantan strain expressing an avian-derived influenza h5n1 hemagglutinin induce broadly neutralizing antibodies and cross-clade protective immunity in mice.to combat the possibility of a zoonotic h5n1 pandemic in a timely fashion, it is necessary to develop a vaccine that would confer protection against homologous and heterologous human h5n1 influenza viruses. using a replicating modified vaccinia virus tian tan strain (mvtt) as a vaccine vector, we constructed mvttha-qh and mvttha-ah, which expresses the h5 gene of a goose-derived qinghai strain a/bar-headed goose/qinghai/1/2005 or human-derived anhui strain a/anhui/1/2005. the immunogenicity prof ...201324358269
experimental infection of bar-headed geese (anser indicus) and ruddy shelducks (tadorna ferruginea) with a clade 2.3.2 h5n1 highly pathogenic avian influenza virus.since 2005, clade 2.2 h5n1 highly pathogenic avian influenza (hpai) viruses have caused infections and morbidity among numerous species of wild waterfowl in eurasia and africa. however, outbreaks associated with clade 2.3.2 viruses have increased since 2009, and viruses within this clade have become the dominant strain of the h5n1 hpai virus detected in wild birds, reaching endemic status in domestic birds in select regions of asia. to address questions regarding the emergence and expansion of c ...201323735616
reverse engineering the antigenic architecture of the haemagglutinin from influenza h5n1 clade 1 and 2.2 viruses with fine epitope mapping using monoclonal antibodies.the induction of neutralising antibodies to the viral surface glycoprotein, haemagglutinin (ha) is considered the cornerstone of current seasonal and pandemic influenza vaccines. mapping of neutralising epitopes using monoclonal antibodies (mabs) helps define mechanisms of antigenic drift, neutralising escape and facilitates pre-pandemic vaccine design. in the present study we reverse engineered the antigenic structure of the has of two highly pathogenic h5n1 vaccine strains representative of cu ...201323127859
antigenic diversity and cross-reactivity of avian influenza h5n1 viruses in egypt between 2006 and 2011.influenza epidemics are a major health concern worldwide. highly pathogenic avian influenza (hpai) h5n1 viruses in egypt have been subject to rapid genetic and antigenic changes since the first outbreak in february 2006 and have been endemic in poultry in egypt since 2008. in this study, 33 h5n1 viruses isolated from avian hosts were antigenically analysed by using a panel of eight mabs raised against the a/viet nam/1203/04 (h5n1; clade 1) and a/bar-headed goose/qinghai-lake/1a/05 (h5n1; clade 2 ...201222956735
characterization of immune responses induced by immunization with the ha dna vaccines of two antigenically distinctive h5n1 hpaiv isolates.the evolution of the h5n1 highly pathogenic avian influenza virus (hpaiv) has resulted in high sequence variations and diverse antigenic properties in circulating viral isolates. we investigated immune responses induced by ha dna vaccines of two contemporary h5n1 hpaiv isolates, a/bar-headed goose/qinghai/3/2005 (qh) and a/chicken/shanxi/2/2006 (sx) respectively, against the homologous as well as the heterologous virus isolate for comparison. characterization of antibody responses induced by imm ...201222859976
eco-virological approach for assessing the role of wild birds in the spread of avian influenza h5n1 along the central asian flyway.a unique pattern of highly pathogenic avian influenza (hpai) h5n1 outbreaks has emerged along the central asia flyway, where infection of wild birds has been reported with steady frequency since 2005. we assessed the potential for two hosts of hpai h5n1, the bar-headed goose (anser indicus) and ruddy shelduck (tadorna tadorna), to act as agents for virus dispersal along this 'thoroughfare'. we used an eco-virological approach to compare the migration of 141 birds marked with gps satellite transm ...201222347393
antibodies to influenza a virus in wild birds across mongolia, 2006-2009.wild waterbirds sampled july 2006-september 2009 in mongolia were tested for antibodies to avian influenza (ai) virus with the use of a commercially available blocking enzyme-linked immunosorbent assay. antibodies were detected in 25% (572/2,282) of tested birds representing 26 species, and all antibody-positive samples were from 12 species in the orders anseriformes and charadriiformes. the highest antibody prevalence was in ruddy shelducks (tadorna ferruginea; 61.7%; n=261; 95% confidence inte ...201222740544
avian hemosporidian parasite lineages in four species of free-ranging migratory waterbirds from mongolia, 2008.avian hemosporidian parasites have been detected in asia, but little information is known about the hemosporidian parasite lineages that circulate in waterbirds that migrate along the east asian and central asian migratory flyways to breed in mongolia. to gather baseline data on hemosporidian parasite presence in mongolian waterbirds, 151 blood-spot samples (81 hatch year [hy] and 70 after hatch year [ahy]) from bar-headed goose (anser indicus), ruddy shelduck (tadorna ferruginea), great cormora ...201627243330
draft genome sequence of staphylococcus hominis bhg17 isolated from wild bar-headed goose (anser indicus) feces.staphylococcus hominis belongs to a group of coagulase-negative staphylococci and is an opportunistic pathogen, usually found on the skin and mucous membranes. studies involving s. hominis isolated from wild birds are scarce. here, we report a 2.365-mb draft genome sequence of s. hominis bhg17, isolated from the feces of a bar-headed goose.201728153901
bohr effect of avian hemoglobins: quantitative analyses based on the wyman equation.the bohr effect data for bar-headed goose, greylag goose and pheasant hemoglobins can be fitted with the wyman equation for the bohr effect, but under one proviso: that the pka of his146β does not change following the t→r quaternary transition. this assumption is based on the x-ray structure of bar-headed goose hemoglobin, which shows that the salt-bridge formed between his146β and asp94β in human deoxyhemoglobin is not formed in goose deoxyhemoglobin. when the bohr data for chicken hemoglobin w ...201627614259
metagenomic profiling of gut microbial communities in both wild and artificially reared bar-headed goose (anser indicus).bar-headed goose (anser indicus), a species endemic to asia, has become one of the most popular species in recent years for rare bird breeding industries in several provinces of china. there has been no information on the gut metagenome configuration in both wild and artificially reared bar-headed geese, even though the importance of gut microbiome in vertebrate nutrient and energy metabolism, immune homeostasis and reproduction is widely acknowledged. in this study, metagenomic methods have bee ...201727998035
altitude matters: differences in cardiovascular and respiratory responses to hypoxia in bar-headed geese reared at high and low altitudes.bar-headed geese (anser indicus) fly at high altitudes during their migration across the himalayas and tibetan plateau. however, we know relatively little about whether rearing at high altitude (i.e. phenotypic plasticity) facilitates this impressive feat because most of what is known about their physiology comes from studies performed at sea level. to provide this information, a comprehensive analysis of metabolic, cardiovascular and ventilatory responses to progressive decreases in the equival ...201627385754
the complete mitochondrial genome of anser indicus (aves, anseriformes, anatidae).the bar-headed goose is known one of the world's highest-flying birds. in this study, the complete mitochondrial genome of anser indicus (16,728 bp in length) was sequenced. similar to the typical mtdna of other vertebrates, goose mtdna contained 37 genes (13 protein-coding genes, 2 rrna genes and 22 trna genes) and a non-coding region (d-loop). the characteristics of the mitochondrial genome were analyzed in detail. we deduce that nd5 may be a major gene required for adaptation to high-altitude ...201627210615
high-throughput sequencing reveals the core gut microbiome of bar-headed goose (anser indicus) in different wintering areas in tibet.elucidating the spatial dynamic and core gut microbiome related to wild bar-headed goose is of crucial importance for probiotics development that may meet the demands of bar-headed goose artificial breeding industries and accelerate the domestication of this species. however, the core microbial communities in the wild bar-headed geese remain totally unknown. here, for the first time, we present a comprehensive survey of bar-headed geese gut microbial communities by illumina high-throughput seque ...201626842811
comparative analysis of the gastrointestinal microbial communities of bar-headed goose (anser indicus) in different breeding patterns by high-throughput sequencing.the bar-headed goose is currently one of the most popular species for rare birds breeding in china. however, bar-headed geese in captivity display a reduced reproductive rate. the gut microbiome has been shown to influence host factors such as nutrient and energy metabolism, immune homeostasis and reproduction. it is therefore of great scientific and agriculture value to analyze the microbial communities associated with bar-headed geese in order to improve their reproductive rate. here we descri ...201626686614
validation of the i-stat and hemocue systems for the analysis of blood parameters in the bar-headed goose, anser indicus.every year, bar-headed geese (anser indicus) perform some of the most remarkable trans-himalayan migrations, and researchers are increasingly interested in understanding the physiology underlying their high-altitude flight performance. a major challenge is generating reliable measurements of blood parameters on wild birds in the field, where established analytical techniques are often not available. therefore, we validated two commonly used portable clinical analysers (pcas), the i-stat and the ...201527293706
matrix m(tm) adjuvanted virosomal h5n1 vaccine induces balanced th1/th2 cd4(+) t cell responses in man.t cellular responses play a significant role in mediating protective immune responses against influenza in humans. in the current study, we evaluated the ability of a candidate virosomal h5n1 vaccine adjuvanted with matrix m(tm) to induce cd4(+) and cd8(+) t cell responses in a phase 1 clinical trial. we vaccinated 60 healthy adult volunteers (at days 0 and 21) with 30 μg haemagglutinin (ha) alone or 1.5, 7.5, or 30 μg ha formulated with matrix m(tm). to evaluate the t cellular responses, lympho ...201425424948
an immunosensor based on antibody binding fragments attached to gold nanoparticles for the detection of peptides derived from avian influenza hemagglutinin h5.this paper concerns the development of an immunosensor for detection of peptides derived from avian influenza hemagglutinin h5. its preparation consists of successive gold electrode modification steps: (i) modification with 1,6-hexanedithiol and gold colloidal nanoparticles; (ii) immobilization of antibody-binding fragments (fab') of anti-hemagglutinin h5 monoclonal antibodies mab 6-9-1 via s-au covalent bonds; and (iii) covering the remaining free space on the electrode surfaces with bovine ser ...201425157550
[the geese who flew home for christmas].gray geese of the bar-headed type (anser indicus synonym: eulabeia indica) perform trans-himalayan migratory flight at extreme altitude. the physiological mechanisms include hyperventilation of cold air, increased lung diffusion capacity, proton gradients, high muscular temperature, amino acid mutation in haemoglobin and cytochrome oxidase, re-location of mitochondria, and extreme shifts in the oxy-haemoglobin dissociation curve due to bohr- and temperature effects. the second annual migration t ...201324629472
an implantable instrument for studying the long-term flight biology of migratory birds.the design of an instrument deployed in a project studying the high altitude himalayan migrations of bar-headed geese (anser indicus) is described. the electronics of this archival datalogger measured 22 × 14 × 6.5 mm, weighed 3 g, was powered by a ½aa-sized battery weighing 10 g and housed in a transparent biocompatible tube sealed with titanium electrodes for electrocardiography (ecg). the combined weight of 32 g represented less than 2% of the typical bodyweight of the geese. the primary task ...201424517787
influence of hbco structure of the bar-headed goose on photolysis thermodynamics as studied by the nanosecond laser-ultrasonic technique.the bar-headed goose, a specialized high-altitude species, has a capacity for high oxygen uptake from a hypoxic environment. it thus has a higher oxygen affinity than other bird species of lower-altitude environments. oxygen affinity is determined by molecular structures and genetic mutations of hemoglobin (hb), which can also influence the coordinating structures and dynamics of oxygen-hb. to explore the structural differences in hbs as between high and low altitude species, photolysis dynamic ...201323748768
high thermal sensitivity of blood enhances oxygen delivery in the high-flying bar-headed goose.the bar-headed goose (anser indicus) crosses the himalaya twice a year at altitudes where oxygen (o2) levels are less than half those at sea level and temperatures are below -20°c. although it has been known for over three decades that the major hemoglobin (hb) component of bar-headed geese has an increased affinity for o2, enhancing o2 uptake, the effects of temperature and interactions between temperature and ph on bar-headed goose hb-o2 affinity have not previously been determined. an increas ...201323470665
the paradox of extreme high-altitude migration in bar-headed geese anser indicus.bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the himalayas, where partial pressure of oxygen is dramatically reduced while flight costs, in terms of rate of oxygen consumption, are greatly increased. such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. in addition, direct empirical measurements of high-altitude flight are lacking. we test whether migrating bar-headed gee ...201323118436
characterization of influenza hemagglutinin interactions with receptor by nmr.in influenza, the envelope protein hemagglutinin (ha) plays a critical role in viral entry by first binding to sialic acid receptors on the cell surface and subsequently mediating fusion of the viral and target membranes. in this work, the receptor binding properties of influenza a ha from different subtypes (h1 a/california/04/09, h5 a/vietnam/1205/04, h5 a/bar-headed goose/qinghai/1a/05, and h9 a/hong kong/1073/99) have been characterized by nmr spectroscopy. using saturation transfer differen ...201222815674
the trans-himalayan flights of bar-headed geese (anser indicus).birds that fly over mountain barriers must be capable of meeting the increased energetic cost of climbing in low-density air, even though less oxygen may be available to support their metabolism. this challenge is magnified by the reduction in maximum sustained climbing rates in large birds. bar-headed geese (anser indicus) make one of the highest and most iconic transmountain migrations in the world. we show that those populations of geese that winter at sea level in india are capable of passin ...201121628594
molecular evolution of cytochrome c oxidase underlies high-altitude adaptation in the bar-headed goose.bar-headed geese (anser indicus) fly at up to 9,000 m elevation during their migration over the himalayas, sustaining high metabolic rates in the severe hypoxia at these altitudes. we investigated the evolution of cardiac energy metabolism and o(2) transport in this species to better understand the molecular and physiological mechanisms of high-altitude adaptation. compared with low-altitude geese (pink-footed geese and barnacle geese), bar-headed geese had larger lungs and higher capillary dens ...201120685719
phylogenetic and structural analysis of the hba (alphaa/betaa) and hbd (alphad/betaa) hemoglobin genes in two high-altitude waterfowl from the himalayas and the andes: bar-headed goose (anser indicus) and andean goose (chloephaga melanoptera).two species of waterfowl living at high altitude provide a prominent example of parallel adaptation at the molecular level. the bar-headed goose (anser indicus) breeds at high elevations in central asia and migrates across the himalayas, where the partial pressure of oxygen (o(2)) is one-third of sea level. in south america, the distantly related andean goose (chloephaga melanoptera) is endemic to the high andes. both species exhibit increased blood-o(2) affinity, which has been attributed to th ...201020434566
high fliers: the physiology of bar-headed geese.up to half the world's population of bar-headed geese (anser indicus) migrate between central asia and india and fly between 5000 m and 9000 m above sea level as they cross the himalayas. the partial pressures of oxygen at these altitudes are, respectively, about 50% and 30% those at sea level. flapping flight is energetically expensive, so how are bar-headed geese able to migrate at such altitudes? the haemoglobin of bar-headed geese has a greater affinity for oxygen than those of lowland birds ...201020116442
control of respiration in flight muscle from the high-altitude bar-headed goose and low-altitude birds.bar-headed geese fly at altitudes of up to 9,000 m on their biannual migration over the himalayas. to determine whether the flight muscle of this species has evolved to facilitate exercise at high altitude, we compared the respiratory properties of permeabilized muscle fibers from bar-headed geese and several low-altitude waterfowl species. respiratory capacities were assessed for maximal adp stimulation (with single or multiple inputs to the electron transport system) and cytochrome oxidase exc ...200919657102
influence of molt on plasma protein electrophoretic patterns in bar-headed geese (anser indicus).plasma protein electrophoresis is recognized as a reliable diagnostic tool in avian medicine; however, the influence of circannual phenomena such as molt on protein electrophoregrams is poorly documented. the molt is a period of heavy hormonal and metabolic change in birds. the purpose of this study was to investigate the effects of molt on total protein concentration and electrophoresis patterns in birds. blood samples were taken from 19 bar-headed geese (anser indicus) from mid-may to mid-augu ...200919617476
have wing morphology or flight kinematics evolved for extreme high altitude migration in the bar-headed goose?bar-headed geese (anser indicus) migrate over the himalayan mountains, at altitudes up to 9000 m above sea level, where air density and oxygen availability are extremely low. this study determined whether alterations in wing morphology or wingbeat frequency during free flight have evolved in this species to facilitate extreme high altitude migration, by comparing it to several closely related goose species. wingspan and wing loading scaled near isometrically with body mass across all species (wi ...200818635402
heart rate and the rate of oxygen consumption of flying and walking barnacle geese (branta leucopsis) and bar-headed geese (anser indicus).we tested the hypotheses that the relationship between heart rate (fh) and the rate of oxygen consumption ((o(2))) differs between walking and flying in geese and that fh and (o(2)) have a u-shaped relationship with flight speed. we trained barnacle geese branta leucopsis (mean mass 2.1 kg) and bar-headed geese anser indicus (mean mass 2.6 kg) to walk inside a respirometer on a treadmill and to fly in a wind tunnel with a respirometry mask at a range of speeds. we measured fh and (o(2)) simultan ...200212324544
crystallization and preliminary crystallographic studies of bar-headed goose fluoromethaemoglobin with inositol hexaphosphate.bar-headed goose fluoromethaemoglobin (fluoromet-hb) complexed with inositol hexaphosphate (ihp) has been crystallized using peg 6000 as precipitant. the crystal belongs to space group p2(1), with unit-cell parameters a = 59.8, b = 72.0, c = 79.8 a, beta = 102.1 degrees, and diffracts to 2.5 a resolution. to prove the presence of ihp, the structure was determined by the molecular-replacement method. ihp was observed at the entrance to the central cavity between the n and c termini of two beta su ...200010957640
the second space experiment of protein crystallization with domestic facilities.the second experiment of protein crystallization was performed on domestic re-entry satellite fsw-2 in 1994-07. the results are superior to the ones of the first mission in 1992: 9 of 10 different proteins were crystallized in space, and 70% of the total 48 samples yielded single crystals. besides hen egg-white lysozyme which grew high-quality crystals on the first mission, an acidic phospholipase a2(apla2) from snake venom and hemoglobin from anser indicus produced good-quality crystals suitabl ...19969772349
cardiopulmonary function in exercising bar-headed geese during normoxia and hypoxia.to investigate possible physiologic mechanisms that allow the bar-headed goose to perform strenuous physical activity when flying at high altitude (e.g., above 9,000 m), we measured cardiopulmonary variables during running exercise (treadmill; 0.6 m.sec-1; 2 degrees incline) while the bird breathed either normoxic (21% o2) or hypoxic (7% o2) gases via a face mask. 1. during normoxic exercise, o2 uptake rate doubled and both ventilation and cardiac output increased. blood gases and ph in arterial ...19892506620
[molecular aspects of high altitude respiration of birds. hemoglobins of the striped goose (anser indicus), the andean goose, (chloephaga melanoptera) and vulture (gyps rueppellii)].respiration of birds at high altitude and the structural adaptation of avian hemoglobins are studied. applying the method of the "minimal biological distance", hemoglobins of closely related species were sequenced and compared with each other. physiological measurements and sequence data show that adaptation to hypoxic stress can be interpreted as exchange of one amino acid. the structural aspects of the genetical data are discussed on the basis of the atomic model of hemoglobin. high-altitude r ...19883205309
regional circulatory responses to hypocapnia and hypercapnia in bar-headed geese.to investigate mechanisms that may allow birds to tolerate extreme high altitude (hypocapnic hypoxia), we examined the effects of severe hypocapnia and moderate hypercapnia on regional blood flow in bar-headed geese (anser indicus), a species that flies at altitudes up to 9,000 m. cerebral, coronary, and pectoral muscle blood flows were measured using radioactive microspheres, while arterial co2 tension (paco2) was varied from 7 to 62 torr in awake normoxic birds. arterial blood pressure was not ...19863082220
seasonal changes in follicle-stimulating hormone in a breeding population of barheaded geese, anser indicus.changes in the plasma titers of follicle-stimulating hormone were investigated in a free-living population of barheaded geese over the whole year. adult males had pronounced seasonal changes from prebreeding levels of approximately equal to 20 ng/ml to a peak in the breeding season of about 300 ng/ml. changes in females were only slight. an increase from nondetectable, approximately equal to 20 ng/ml to a mean of 32.2 ng/ml before egg-laying was found. the data are discussed with regard to the l ...19853920119
effects of hypoxia on tissue capillarity in geese.tissue capillarity in the gastrocnemius and myoglobin concentrations in the gastrocnemius and heart were determined for hatchling canada geese, branta canadensis, following incubation of the embryos under either normoxic (po2 = 120 torr) or hypoxic (po2 = 94 torr) conditions. similar observations were made on a limited number of hatchling bar-headed geese, anser indicus, a species native to high altitude. capillary densities were higher and diffusion distances shorter in the hypoxic canada geese ...19846522870
respiratory properties of blood from embryos of highland vs. lowland geese.respiratory properties of whole blood during development were studied in embryos of the bar-headed and canada geese. in both species, affinity of the blood for o2 [expressed as o2 half-saturation pressure (p50)] increased with development, to a low and stable value. the low and stable p50 at ph 7.4 for the bar-headed goose, 20.1 +/- 0.3 torr, is significantly lower than that for the canada goose, 26.9 +/- 0.8 torr. the data suggest a higher bohr effect for the bar-headed goose. hill's coefficien ...19827153141
seasonal changes in the behavior and plasma titers of various hormones in barheaded geese, anser indicus.a number of behavioral and physiological parameters including the circulating levels of 7 hormones were investigated in a free ranging population of barheaded geese in seewiesen, w. germany. behavioral data were collected on the entire flock from which seasonal changes in the frequencies were determined. in addition, data on the behavior of individuals were obtained to aid in the comparison of seasonal changes in behavior and hormones. the resulting curves were used to examine whether the annual ...19817269825
[production, development and function of the vocalization of four species of geese (anser indicus, a. albifrons and branta canadensis)]. 19705524987
integrative approaches for studying mitochondrial and nuclear genome co-evolution in oxidative phosphorylation.in animals, interactions among gene products of mitochondrial and nuclear genomes (mitonuclear interactions) are of profound fitness, evolutionary, and ecological significance. most fundamentally, the oxidative phosphorylation (oxphos) complexes responsible for cellular bioenergetics are formed by the direct interactions of 13 mitochondrial-encoded and ∼80 nuclear-encoded protein subunits in most animals. it is expected that organisms will develop genomic architecture that facilitates co-adaptat ...201728316610
do bar-headed geese train for high altitude flights?exercise at high altitude is extremely challenging, largely due to hypobaric hypoxia (low oxygen levels brought about by low air pressure). in humans, the maximal rate of oxygen consumption decreases with increasing altitude, supporting progressively poorer performance. bar-headed geese (anser indicus) are renowned high altitude migrants and, although they appear to minimize altitude during migration where possible, they must fly over the tibetan plateau (mean altitude 4800 m) for much of their ...201728859401
high-altitude champions: birds that live and migrate at altitude.high altitude is physiologically challenging for vertebrate life for many reasons, including hypoxia (low environmental oxygen); yet, many birds thrive at altitude. compared to mammals, birds have additional enhancements to their oxygen transport cascade, the conceptual series of steps responsible for acquiring oxygen from the environment and transporting it to the mitochondria. these adaptations have allowed them to inhabit a number of high-altitude regions. waterfowl are a taxon prolific at al ...201728839002
the physiological basis of bird flight.flapping flight is energetically more costly than running, although it is less costly to fly a given body mass a given distance per unit time than it is for a similar mass to run the same distance per unit time. this is mainly because birds can fly faster than they can run. oxygen transfer and transport are enhanced in migrating birds compared with those in non-migrators: at the gas-exchange regions of the lungs the effective area is greater and the diffusion distance smaller. also, migrating bi ...201627528774
how bar-headed geese fly over the himalayas.bar-headed geese cross the himalayas on one of the most iconic high-altitude migrations in the world. heart rates and metabolic costs of flight increase with elevation and can be near maximal during steep climbs. their ability to sustain the high oxygen demands of flight in air that is exceedingly oxygen-thin depends on the unique cardiorespiratory physiology of birds in general along with several evolved specializations across the o2 transport cascade.201525729056
mapping migratory flyways in asia using dynamic brownian bridge movement models.identifying movement routes and stopover sites is necessary for developing effective management and conservation strategies for migratory animals. in the case of migratory birds, a collection of migration routes, known as a flyway, is often hundreds to thousands of kilometers long and can extend across political boundaries. flyways encompass the entire geographic range between the breeding and non-breeding areas of a population, species, or a group of species, and they provide spatial frameworks ...201525709838
the roller coaster flight strategy of bar-headed geese conserves energy during himalayan migrations.the physiological and biomechanical requirements of flight at high altitude have been the subject of much interest. here, we uncover a steep relation between heart rate and wingbeat frequency (raised to the exponent 3.5) and estimated metabolic power and wingbeat frequency (exponent 7) of migratory bar-headed geese. flight costs increase more rapidly than anticipated as air density declines, which overturns prevailing expectations that this species should maintain high-altitude flight when trave ...201525593180
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