4,177 research outputs found
Role of antibodies and T cells in pigeon fanciers' lung
No full textAbstract: Introduction: Pigeon fanciers’ lung (PFL) is one of the most common forms of hypersensitivity pneumonitis (HP) in the UK. Generally it is considered that PFL is caused by immune complexes, however, this does not explain why some fanciers are asymptomatic despite the presence of high levels of anti-avian antigen antibodies in their serum. Pigeon intestinal mucin (PIM) is considered to be an important antigen in PFL. Thus this study was designed in order to understand the role of specific antibodies and T cells in the pathogenesis of PFL. Methods: Anti-avian IgG and IgG subclass responses among 50 symptomatic and 50 asymptomatic pigeon fanciers were determined by ELISA and the functional affinity of IgG1 and IgG2 against a range of pigeon antigens was determined by inhibition ELISA and microcalimetry. Mucin-specific T cell clones were also generated from pigeon fanciers and T cell phenotypes and cytokine profile of these cells were identified. Results: The median titres of IgG1 and IgG2 against all the pigeon antigens tested was always higher in asymptomatic than symptomatic fanciers and these differences were significant for anti-PS IgG1 (P=0.04), anti-PDF IgG2 (P=0.028), anti-PDO IgG2 (P=0.04) and anti-PIS IgG2 (P=0.03). The functional affinity of IgG1 and IgG2 against PDO was higher in symptomatic individuals as compared to asymptomatic fanciers (P=0.006 and P=0.002, respectively) whilst the functional affinity of anti-PDF IgG2 was also significantly higher in these patients (P?0.001). Symptomatic fanciers were also significantly more likely to have high ?H and thus had higher avidity antibodies against PDO (P=0.044). 12 T cell clones specific for t mucin also were generated from an asymptomatic fancier and 90-96% of clone 04, 22, 23 were CD4-CD8- double negative (DN). Conclusion: The data suggests that the magnitude of the serum antibody response cannot determine the development of the disease and as symptomatic fanciers had higher IgG antibody avidities and therefore immune complexes in individuals with PFL may have a stronger composition and bonds. In addition, this is the first demonstration of the use of ITC to measure antibody avidity in a clinical situation. This is a rapid and simple method of measuring antibody avidity and has a diagnostic potential in PFL. Finally t mucin-specific T cell clones with double negative phenotype may have a crucial role in immune regulation in asymptomatic fanciers and can be one of the reasons why these individuals do not have any symptoms in spite of having high antibody responses
Passaging of a Newcastle disease virus pigeon variant in chickens results in selection of viruses with mutations in the polymerase complex enhancing virus replication and virulence
No full textSome Newcastle disease virus (NDV) variants isolated from pigeons (pigeon paramyxovirus type 1; PPMV-1) do not show their full virulence potential for domestic chickens but may become virulent upon spread in these animals. In this study we examined the molecular changes responsible for this gain of virulence by passaging a low-pathogenic PPMV-1 isolate in chickens. Complete genome sequencing of virus obtained after 1, 3 and 5 passages showed the increase in virulence was not accompanied by changes in the fusion protein – a well known virulence determinant of NDV – but by mutations in the L and P replication proteins. The effect of these mutations on virulence was confirmed by means of reverse genetics using an infectious cDNA clone. Acquisition of three amino acid mutations, two in the L protein and one in the P protein, significantly increased virulence as determined by intracerebral pathogenicity index tests in day-old chickens. The mutations enhanced virus replication in vitro and in vivo and increased the plaque size in infected cell culture monolayers. Furthermore, they increased the activity of the viral replication complex as determined by an in vitro minigenome replication assay. Our data demonstrate that PPMV-1 replication in chickens results in mutations in the polymerase complex rather than the viral fusion protein, and that the virulence level of pigeon paramyxoviruses is directly related to the activity of the viral replication complex
On the epidemiology, biology and food-dependent reproduction of the feral pigeon (Columba livia)
No full textMillions of feral pigeons (Columba livia, Gmelin 1789) live in close association with the human population in our cities. They have managed to adapt extremely well to city life. The partial absence of an effective regulation by enemies and the rich food basis in urban habitats allows the development and maintenance of large feral pigeon populations. These, however, can cause various problems such as fouling with feces, and the transmission of pathogenic microorganisms and parasites to humans. While many wild-living species have a parasitic fauna comparable to that of feral pigeons, no other species lives as close to humans and offers that many possibilities of transmission. Feral pigeons breeding and roosting close to human lodgings thus pose a serious health risk, which is why many homeowners try to protect themselves by repelling the birds from their house facades, window ledges and balconies.
New pigeon proofing systems are regularly introduced onto the market, but scientific proof of efficacy and a statement regarding their use from the point of view of animal welfare is usually lacking. We therefore evaluated the effectiveness of two gel repellents on free ranging feral pigeons in an experimental pigeon loft. The gels used an alleged tactile or visual aversion of the birds, reinforced by additional sensory cues. This study concludes that both gels show a restricted, transient repellent effect, but fail to prove the claimed complete effectiveness. In addition, the adhesive effect of the gels conflicts with animal welfare concerns because gluing of plumage presents a serious risk to feral pigeons and also to other non-target birds. The repellent gels are therefore not suitable for feral pigeon management in urban areas.
Additionally, an overview of the most essential pigeon proofing systems is provided within the frame of this thesis. It discusses the advantages and disadvantages of the most widespread systems and further sets the focus on animal welfare issues. The overview points out that even initially harmless and animal friendly proofing systems might become dangerous to the birds over time if they are not regularly maintained. It further highlights how important it is to scientifically test each system before usage. Moreover, this outline supports the recommendation that each system should come with a proper installation and maintenance guide when it is introduced onto the market. If untested systems are being put to the test by unknowing end users, they might endanger the birds. Additionally, uninformed homeowners violate the animal protection law if a system harms an animal, even if this happens with no ill intent.
In a further study, we examined the effect of a sudden decrease in the natural food basis on the reproduction of a well-studied feral pigeon breeding colony. Despite the known fact that food shortage is a major source of reproductive failure in feral pigeons, it was still unclear at which phase of the reproductive cycle it reduces overall reproductive success. The findings of this study imply that the number of broods per pair decreased significantly under food reduction, while the hatching success remained more or less constant. However, a significantly greater number of nestlings died during the costly rearing phase. Results suggest that the high energy demand of the fast growing feral pigeon nestlings cannot be met under food scarcity. The decreased number of broods and the limited fledging success consequently reduce the total number of fledged young by more than half, which finally leads to a decrease in colony size.
Another negative side effect of large feral pigeon populations, maintained through the abundant anthropogenic nutritional basis in urban surroundings, is the overcrowding at breeding places. From an epidemiological point of view, these high population densities can increase the transmission of pathogenic microorganisms and parasites, such as the pigeon tick Argas reflexus. The medically and veterinary important A. reflexus usually feeds on pigeons, but if a natural host is not available, it also enters dwellings to bite humans who can respond with severe allergic reactions including anaphylactic shock. The pigeon tick is ecologically extremely successful due to certain outstanding morphological, physiological, and ethological features. Yet, until today, it was still unclear how it finds its hosts. In the main study, we tested different host stimuli, such as living nestlings as well as begging calls, body heat, smell, host breath and pigeon tick feces, under controlled laboratory conditions. Of all stimuli tested, only heat seemed to play a central role in host-finding. Subsequently, the crucial heat stimulus was tested under natural conditions within a pigeon loft. The results demonstrated that the host finding ability of A. reflexus is restricted to only a few centimeters. We concluded that this ectoparasite finds its host by random movements and recognizes it only shortly before direct contact is made. These findings are useful for the control of A. reflexus in infested apartments, both to diagnose an infestation and to perform successful monitoring after disinfestation.
The aim of this thesis was to provide important insights into the epidemiology, biology and food-dependent reproduction of the feral pigeon. With these findings we hope to contribute to the healthier coexistence of feral pigeons and humans in urban habitats
Hydrologic Events and Water Quality in the Pigeon River, Ottawa County, Michigan
No full textThe Pigeon River drains a 16,765-ha agricultural watershed in western Ottawa County, Michigan and discharges into south-central Lake Michigan. Extensive areas of wetlands in the upper watershed were drained in the 1920s, causing significantly altered hydrology characteristics by flashy discharges during storms and periods of snowmelt. We studied stream chemistry and hydrology for a four-year period between September, 1996, and October, 2000, to determine water quality status, to estimate annual nutrient exports, and to evaluate the effects of different seasonal flow types. Results of our study confirmed that the upper reaches of the Pigeon River experience chronically degraded water quality, with contributions from both nonpoint and point sources. As a result, the watershed has high annual rates of nutrient export (approximately 10.8 kg ha-1 inorganic N and 0.25 kg ha-1 PO4-P). With the influx of groundwater, change in land use to forest, and development of natural stream channel characteristics in the lower mainstream, water quality at baseflow in this section of the Pigeon River improves to the point where coldwater fish populations should persist. Inputs of degraded water during high flows, however, produce periods of environmental stress and the fish population in the lower Pigeon includes only a low number of pollution-tolerant, warmwater species. Large summer storms are biologically stressful because of increased temperatures and reduced dissolved oxygen levels, while spring storms and snowmelt contribute substantially to total nutrient suspended solids exports. Efforts to improve water quality in this and similar agricultural watersheds need to emphasize major reductions in the nonpoint source inputs through substantial improvements in land and water management practices. Wetland restoration and implementation of other stormwater retention practices in such watersheds also are required to reverse the acute impacts of high stormwater discharges caused by past drainage and steam channelization
Latvian Canadian Immigrants at Pigeon Lake
No full textBlack & White photo of Tom Pederson, family and perhaps acquaintences at Pigeon Lake4.0 Latvian Immigration into Canada, 4.1.1 First Wave Immigrants, 5.0 Early life of Latvians in Alberta,, 5.1.2 Lake Isl
Negative Externalities on Property Values Resulting from Water Impairment: The Case of the Pigeon River Watershed
No full textThe following hypothesis was tested: Willingness to bear a negative water impairment externality differs between those who do and those who do not receive economic benefit from the impairment source, e.g., a paper mill. The hypothesis was tested using a hedonic analysis of ambient water quality in two discrete housing markets in the Pigeon River Watershed, which have been polluted by the operation of a paper mill. The results suggest that North Carolina residents of the subwatersheds with impaired river, who experience economic benefits from the paper mill in addition to harmful effects, do perceive the pollution as a negative externality, whereas they may have a willingness to bear a similar type of negative externality associated with impaired streams. In contrast, the effects of both degraded river and streams on property values is perceived as a negative externality by residents in the Tennessee side, who experience only harmful effects from the pollution. North Carolina residents may hold greater willingness to bear the harmful effects of pollution as a given condition in their decision-making process because they receive economic benefits from the paper mill, while this internalization of the negative externality is weaker for residents in the Tennessee side.negative Externalities, water quality, spatial hedonic model, Environmental Economics and Policy,
The Auzin's Extended Family Celebrating a Birthday at Pigeon Lake, Alberta
No full textThe extended Auzins family celebrating a birthday at the family farm at Pigeon Lake, Alberta15.0 Family photos, 15.1.4 Group Family Photos in Alberta, 8.1.3 Family Hom ein Albert
pigeon
No full textpigeon nSoon after the pigeons and saddlers arrive, the first harp seals begin to migrate north along the floe edge. p. 202 Pigeon is the comon Settler name for the black guillemot.PRINTED ITEM DNE-citUsed I and SupUsed I and SupUsed
On the biology and epidemiology of the feral pigeon (Columba livia)
No full textFeral pigeons (Columba livia, Gmelin 1789) are among the most abundant vertebrates in the urban environment of almost every city in the world. Close contacts to humans bear the risk of transmission of zoonotic pathogens and parasites. The most important of these zoopathogens is the bacterium Chlamydia psittaci, the agent of avian chlamydiosis and human psittacosis/ornithosis. Many human infections reported in the medical literature were attributed to brief and transient contacts to feral pigeons in the urban environment. The aim of the present thesis is to investigate the prevalence of C. psittaci in the feral pigeon population of Basel, to identify possible routes of transmission in the city and to propose measures for the prevention of zoonotic C. psittaci transmissions.
In a preliminary study, 47 faecal samples were collected from nest boxes in a feral pigeon loft in Basel, Switzerland. In addition 34 samples were collected from the feather dust film on the water surface of public fountains, where feral pigeons regularly bathe. All 81 samples were tested for the presence of chlamydial antigen by use of an antigen-ELISA assay. Initially the ELISA assay yielded a high proportion of positive results: 8 out of 47 (23.5 %) faecal samples and 26 out of 34 (76.5 %) of the water film samples were tested positive. However, a subsequent blocking test revealed only one true positive faecal sample, which could be confirmed by microarray. This ELISA assay was not used for further studies.
In the main study, the prevalence of C. psittaci shedding in free ranging feral pigeons living in a pigeon loft in Basel was investigated. A total of 202 individual birds were tested on four different time points between 2007 and 2009 by analysis of pharyngeal and cloacal swabs. Some of the birds could be tested repeatedly. All samples were analyzed by use of a species-specific nested PCR assay targeting the ompA gene of C. psittaci. The tested feral pigeons were shedding C. psittaci by respiratory secretions, since 9 out of 447 (2.0 %) of the pharyngeal swabs were tested positive. Furthermore, 11 out of 348 (3.2 %) of the cloacal swabs were tested positive, indicating that these birds are shedding C. psittaci in their faecal droppings. In total, C. psittaci was documented in 17 of 202 individual birds (8.4 %). The majority of the positive birds were shedding the pathogen intermittently. At present, this is the first study to test individual free-living feral pigeons repeatedly and therefore the first to prove intermittent shedding of C. psittaci in these birds. Genotyping of the positive samples by real-time PCR revealed C. psittaci genotype B in 7 of the birds, as well as a mixed infection with the genotypes A, B and E/B in one bird. A mixed infection with three different chlamydial genotypes could be documented for the first time. Seven of the birds that tested positive immigrated into the pigeon loft as adults, including the bird with the mixed infection. Thus, it could be proven how the interconnectedness of feral pigeon subpopulations favours the spread of pathogens. Additionally, 620 faecal samples from public sites in the city were analyzed. However, C. psittaci could not be detected in these faecal samples from the urban environment.
Feral pigeons on building facades, on balconies and window ledges, or in open attics pose a health risk. Avoiding attractive building structures already during building design is the best and most cost-effective way to prevent problems with feral pigeons in the future. We identified the structural parameters required to proof a building against feral pigeons. It could be demonstrated that feral pigeons are not able to pass through an outlet width of 4 cm, the respective outlet height is 5 cm, and a pigeon-safe square opening size is not exceeding 6 × 6 cm. A feral pigeon is not able to sit on a ledge if it’s width is 4 cm or smaller. The pigeon-safe angle of inclination for smooth construction materials (tinplate, glass, plastics) is 25°, for medium rough materials (wood, plane concrete) 35°, and for rough materials (sandstone, rough concrete) at least 50°. With these essential data, required to proof a building against feral pigeons, we contribute to the prevention of disease transmissions and parasite infestations due to these birds.
The low proportion of our feral pigeons in Basel, which are shedding C. psittaci, could be documented. However, C. psittaci could not be detected in faecal samples from public sites in the urban environment. The regular cleaning of streets and squares in Basel additionally contributes to public health, since potentially infectious feral pigeon faeces are removed quickly. Considering the numerous opportunities of close contacts to feral pigeons in the urban environment, a transmission of the pathogen from feral pigeons to humans can never be ruled out. Therefore, feral pigeons present a significant potential health risk
Birthday Celebration at Pigeon Lake Family Farm (food tent)
No full textThe Auzins family at a birthday celebration at the family farm at Pigeon Lake (sitting under food tent)8.0 Family Home in Alberta, 9.0 Life in Edmonton and Alberta, 15.1.3 Family Life in Albert
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