201 research outputs found
Living with the Lesser Black-backed Gull in the Dutch Delta
No full textIn advanced capitalist societies, nature has become more dependent on human influence. But some species are living in closer proximity than others. Including the Lesser Black-backed Gull. Throughout the 20th century, human activities have led to changes in the environment of this “synanthropic” species, a species living in close proximity to humans, not only affecting the size of the population but also the place where they settle. Animals that follow us as humans are often unappreciated and therefore present a challenge.The Lesser Black-backed Gull is a migratory bird, of which almost 80,000 pairs are spending their breeding season starting from February until September in the Netherlands. It is a relatively new species here that is normally loyal to their breeding ground. However, since its first appearance, colonies have already been displaced from the Dutch dunes to large vacant lots on industrial sites in the Dutch Delta and urban environments.Because they cause different types of nuisance and friction in the latter two, port owners and municipalities are trying to work around the protected status of the species by, amongst others, applying for exemptions. But ultimately, we ourselves are the driving factor, so the solution will also lie in recognising the agency of these species by studying their response to our entanglements while learning to live alongside them. Therefore, this project aimed to design an intervention that contributes to a sustainable life for the Lesser Black-backed Gull in the context of the Dutch Delta, by taking a gulls’ perspective and examining the Lesser Black-backed Gull’s desires based on our current entanglements. As design-with-animals methods are still scarce, the design approach is made up by taking both parts of More-Than-Human design theory and systemic design practices. First, the relations or entanglements between gulls and humans over time and the effects on their population and human-gull interactions were explored. And finally, in case studies of the Port of Rotterdam and cities, attempts were made to understand what is driving gulls to settle there, the interactions between humans and gulls that arise, and the different perspectives of actors on how to deal with the gull in the future. Human-induced changes in the environment of gulls are both causing them to respond in unpredictable ways by dispersing, and are causing the population to decline, potentially threatening the Natura2000 conservation objective. For these reasons, an intervention has ultimately been proposed for co-habitation in the Port of Rotterdam, which can function as an important example for the many industrial areas in the (Southwestern) Delta.The Port of Rotterdam, and especially the area of Europoort West is both meaningful to humans as gulls. The largest colony of Lesser Black-backed Gulls in the world is settled here, in the largest port in Europe. Various affordances, while being a species of routines, make it a meaningful place for the gulls.The intervention is called “Land van Meeuw en Mens” and should ensure that gulls are taken into account in the world we design while highlighting their acknowledged agency to employees and visitors.The “Land van Meeuw en Mens” first consists of a spatial redesign of an area where gulls and humans are crossing paths. Secondly, it consists of a design proposal for gull roofs that are currently arising from the popular breeding area, but do not yet take into account the loss of habitat for this species. The last proposal includes a breeding object that has been further developed to translate the affordances of their previous nesting site to the roof.Last but not least, the specific case of the Lesser Black-backed gulls can be seen as an example of how humans and other species can share living space as we will continue to entangle.Integrated Product Desig
Cytochrome oxidase subunit VI of Trypanosoma brucei is imported without a cleaved presequence and is developmentally regulated at both RNA and protein levels
No full textMitochondrial respiration in the African trypanosome undergoes dramatic developmental stage regulation. This requires co-ordinated control of components encoded by both the nuclear genome and the kinetoplast, the unusual mitochondrial genome of these parasites. As a model for understanding the co-ordination of these genomes, we have examined the regulation and mitochondrial import of a nuclear-encoded component of the cytochrome oxidase complex, cytochrome oxidase subunit VI (COXVI). By generating transgenic trypanosomes expressing intact or mutant forms of this protein, we demonstrate that COXVI is not imported using a conventional cleaved presequence and show that sequences at the N-terminus of the protein are necessary for correct mitochondrial sorting. Analyses of endogenous and transgenic COXVI mRNA and protein expression in parasites undergoing developmental stage differentiation demonstrates a temporal order of control involving regulation in the abundance of, first, mRNA and then protein. This represents the first dissection of the regulation and import of a nuclear-encoded protein into the cytochrome oxidase complex in these organisms, which were among the earliest eukaryotes to possess a mitochondrion
Replication of 2 subtypes of low-pathogenicity avian influenza virus of duck and gull origins in experimentally infected mallard ducks
No full textMany subtypes of low-pathogenicity avian influenza (LPAI) virus circulate in wild bird reservoirs, but their prevalence may vary among species. We aimed to compare by real-time reverse-transcriptase polymerase chain reaction, virus isolation, histology, and immunohistochemistry the distribution and pathogenicity of 2 such subtypes of markedly different origins in Mallard ducks (Anas platyrhynchos): H2N3 isolated from a Mallard duck and H13N6 isolated from a Ring-billed Gull (Larus delawarensis). Following intratracheal and intraesophageal inoculation, neither virus caused detectable clinical signs, although H2N3 virus infection was associated with a significantly decreased body weight gain during the period of virus shedding. Both viruses replicated in the lungs and air sacs until approximately day 3 after inoculation and were associated with a locally extensive interstitial, exudative, and proliferative pneumonia. Subtype H2N3, but not subtype H13N6, went on to infect the epithelia of the intestinal mucosa and cloacal bursa, where it replicated without causing lesions until approximately day 5 after inoculation. Larger quantities of subtype H2N3 virus were detected in cloacal swabs than in pharyngeal swabs. The possible clinical significance of LPAI virus-associated pulmonary lesions and intestinal tract infection in ducks deserves further evaluation
Disruption of the developmental programme of Trypanosoma brucei by genetic ablation of TbZFP1, a differentiation-enriched CCCH protein
No full textThe regulation of differentiation is particularly important in microbial eukaryotes that inhabit multiple environments. The parasite Trypanosoma brucei is an extreme example of this, requiring exquisite gene regulation during transmission from mammals to the tsetse fly vector. Unusually, trypanosomes rely almost exclusively on post-transcriptional mechanisms for regulated gene expression. Hence, RNA binding proteins are potentially of great significance in controlling stage-regulated processes. We have previously identified TbZFP1 as a trypanosome molecule transiently enriched during differentiation to tsetse midgut procyclic forms. This small protein (101 amino acids) contains the unusual CCCH zinc finger, an RNA binding motif. Here, we show that genetic ablation of TbZFP1 compromises repositioning of the mitochondrial genome, a specific event in the strictly regulated differentiation programme. Despite this, other events that occur both before and after this remain intact. Significantly, this phenotype correlates with the TbZFP1 expression profile during differentiation. This is the first genetic disruption of a developmental regulator in T. brucei. It demonstrates that programmed events in parasite development can be uncoupled at the molecular level. It also further supports the importance of CCCH proteins in key aspects of trypanosome cell function
Environmental and Parental Influences on Offspring Health and Growth in Great Tits (Parus major)
No full textPMCID: PMC3728352This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Sino-African Relations: Economic Opportunities and Challenges for China
No full textAfrica is known for its massive labour force and natural resources. In terms of economic growth, African countries have faced prolonged phases of economic crises. China is a significant contributor in Africa’s economic stability. This paper analyses and evaluates the current opportunities and challenges related to China’s engagements in Africa and its policies for triggering economic development in African countries. China’s comprehensive approach is more concentrated on the sustainable development of the domestic infrastructure and job creation for the Africa communities. But there exists a gap in the current Chinese policies that have deepened the concerns of the locals about economic growth and progress. China needs to develop policies that would be mutually beneficial, these policies must ensure economic stability, job creation and growth. Various ongoing development projects initiated by the Chinese have in fact created insecurities amongst the Africans. This anxiety among the locals have become a major hurdle for China’s plans in the continent. Ongoing Chinese policies need to be innovative along with the integration of modern economic models. A reform in the current policies would ensure maximum benefits for both economic partners
The developmental cell biology of Trypanosoma brucei
No full textTrypanosoma brucei provides an excellent system for studies of many aspects of cell biology, including cell structure and morphology, organelle positioning, cell division and protein trafficking. However, the trypanosome has a complex life cycle in which it must adapt either to the mammalian bloodstream or to different compartments within the tsetse fly. These differentiation events require stage-specific changes to basic cell biological processes and reflect responses to environmental stimuli and programmed differentiation events that must occur within a single cell. The organization of cell structure is fundamental to the trypanosome throughout its life cycle. Modulations of the overall cell morphology and positioning of the specialized mitochondrial genome, flagellum and associated basal body provide the classical descriptions of the different life cycle stages of the parasite. The dependency relationships that govern these morphological changes are now beginning to be understood and their molecular basis identified. The overall picture emerging is of a highly organized cell in which the rules established for cell division and morphogenesis in organisms such as yeast and mammalian cells do not necessarily apply. Therefore, understanding the developmental cell biology of the African trypanosome is providing insight into both fundamentally conserved and fundamentally different aspects of the organization of the eukaryotic cell
Management of sternebral osteomyelitis in a horse
No full textRE: 16 ref.; SC: 0I; ZA; VE; HE; CASource type: Electronic(1) http://upei-resolver.asin-risa.ca?sid=SP:CABI&id=pmid:&id=&issn=0932-0814&isbn=&volume=14&issue=2&spage=111&pages=111-114&date=2001&title=Veterinary%20and%20Comparative%20Orthopaedics%20and%20Traumatology&atitle=Management%20of%20sternebral%20osteomyelitis%20in%20a%20horse.&aulast=Rhoads&pid=%3Cauthor%3ERhoads%2c%20W%20S%3bNeuwirth%2c%20L%3bGull%2c%20T%3bPack%2c%20L%20A%3C%2Fauthor%3E%3CAN%3E20013082123%3C%2FAN%3E%3CDT%3EJournal%20article%3C%2FDT%3
Evaluating UAV-based techniques to census an urban-nesting gull population on Canada's Pacific coast
No full textThe use of unmanned aerial vehicles, or drones, in wildlife monitoring has increased in recent years, particularly in hard-to-access habitats. We used fixed-wing and quadcopter drones to census an urban-nesting population of Glaucous-winged Gulls in Victoria, Canada. We conducted our study over 2 years and asked whether (i) drones represent a suitable survey method for rooftop-nesting gulls in our study region; and (ii) Victoria’s urban gull population had increased since the last survey >30 years earlier. Using orthomosaic imagery derived from drone overflights, we estimated at least a threefold increase over the 1986 count reported for the entire city (from 114 to 346 pairs), and an approximate tenfold increase in the number of gulls nesting in the downtown core. Drones proved to be an excellent platform from which to census rooftop-nesting birds: occupied nests were readily discernible in our digital imagery, and incubating birds were undisturbed by drones. This lack of disturbance may be due to Victoria’s location in an aerodrome; gulls experience dozens of floatplane and helicopter flights per day and are likely habituated to air traffic. Glaucous-winged Gulls have declined considerably at their natural island colonies in the region since the 1980s. Our results indicate that although urban roofs provide replacement nesting habitat for this species, local gull populations have not simply relocated en masse from islands to rooftops in the region.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
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