384 research outputs found
Quantitative Risk Evaluation of Obstacle Limitation Surfaces for Final Approaches at Airports
Obstacle limitation surfaces (OLS) are the main safeguard against objects that can pose a hazard to aircraft operations at and around airports. The standard dimensions of the most of those surfaces were estimated using the pilotâs experience at the time when they were included in the standard documents. As a result, some of these standards may have been overestimated, while others may not provide an adequate level of safety. With airports moving to the Safety Management System (SMS) approach to design and operations safety, proper evaluation of the level of safety provided by OLS at specific sites becomes important to airport operators. Therefore, this study attempts to collect actual flight path data using information provided by air traffic control radars and to construct a methodology to assess the probability of aircraft deviating from their approach path. This will be helpful to estimate safe and efficient standard dimensions of the OLS and assess the risk level of objects to the aircraft operations around airports. The methodology is presented using the aircraft trajectories of approaches at Ottawa International Airport (CYOW). Estimated dimensions of Code 3 approach surfaces also are presented
Air Connectivity and Airport Infrastructure in Northern Canada
To analyze the existing air transportation infrastructure that could potentially benefit from the Canadian Northern Corridor, a list of remote communities was obtained and investigated. A total of 182 communities have been assessed by Transport Canada or the provinces and territories, of which 146 are located inside the proposed Canadian Northern Corridor area. These communities are the focus of our study to answer the following questions:
What is the current level of air transportation infrastructure and services?
What are the existing federal and territorial regarding northern and arctic air connectivity?
What is the potential impact of climate change on air transportation systems in northern Canada?
Policies and Legislation
In Canada, air transportation is regulated by the federal government. As such, there are no provincial or territorial policies regarding air transportation. Air transportation services in Canada are not subject to any economic regulations. Airlines and aircraft operators in general are free to set routes and fares as they wish â subject to operational safety regulations. As such, air services in the North are generally subject to supply and demand.
The Airport Transfer (Miscellaneous Matters) Act that created the National Airports System made no special provisions for airports in Northern Canada.
The Civil Air Navigation Services Commercialisation Act transferred the operation of air navigation services to a private, not-for-profit corporation named NAV Canada. The act includes provisions for the continuance of air navigation services in northern and remote communities, requiring NAV Canada to give advance notice of any changes in service that could affect those communities. If the communities affected reject the proposed change, it will require approval by the Minister of Transportation.
In 2016, the Government of Canada has initiated discussions to set a framework for a specific policy for Canadaâs Arctic and Northern Region. The work on that framework has identified better airport facilities as one of the key infrastructure needs in the region. To the time of writing of this report, no specific policies had been set to address these needs.
Accessibility of Remote Communities to Nearby Airports
140 of the 146 remote communities in this study are served by an airport nearby. Three communities are served by water aerodromes. Only three communities in BC were found to not have an airport or aerodrome nearby.
Most communities have paved and/or gravel road access to the airport. Communities which were identified with nearby airports have fair distances to their respective airports, ranging from 0 to 20 km. The exceptions are the remote communities of Keno, which is more than 50 km away from Mayo Airport in the Yukon; and Iskut, located 86 km from Dease Lake Airport.
Airport Infrastructure
In general, the existing airport infrastructure provides adequate service to the remote communities in Northern Canada. Three of the 146 communities included in this study do not have access to a nearby airport, and three others can only be accessed by seaplanes. Two are accessible by road with distances between 50 and 90 km. All other 138 communities are served by an airport located within 20 km or less.
Improvements may be required to several airports to ensure year-round, all-weather accessibility and convenience. 58% of the airports are not equipped for instrument flights and can only be used under visual flight conditions. It should be noted that the mere availability of instrument approach procedures does not guarantee service, as those procedures also require trained pilots and aircraft equipped with instruments. Only 85% of the runways are not paved, which affects aircraft maintenance and durability. 30% of the airports do not offer winter maintenance, which can affect their availability during and after snow and ice storms. 20% of the airports do not feature a terminal building, leaving the processing of passengers and cargo subject to inclement weather. The costs and benefits of such improvements are likely to vary from airport to airport and should be evaluated in more detail on a case-by-case basis.
Air Connectivity
Compared to other communities, the majority of the remote communities in the northern parts of the provinces are generally well connected, with scheduled services connecting them to regional and international airports. There are, however, several airports with limited or no commercial services. 18% of the airports in this study have no commercial services that connect them regularly to other communities. 7 airports are only served by charter services. Even in the case of the 109 airports that do have regularly scheduled services, the flights are infrequent and costly â it should be noted, however, that this study did not include an assessment of the prices of air tickets serving the Northern remote communities.
One other limitation of this study is the absence of information on cargo and ambulance services. For the latter, the existing runway infrastructure â in terms of length and surface â is sufficient to accommodate aircraft with enough ranges to connect them to a larger airport and/or community. Cargo, however, is severely limited by the size of the aircraft that can operate on the existing runways. Only 44% of the airports can accommodate jet and larger turboprop aircraft. Once more, an economic analysis of cargo operations and the improvements required to improve them is beyond the scope of this study.
This study is also limited to an evaluation of air services in Northern remote communities from a purely air services perspective. Even though a large portion of the communities have adequate services from that point of view, it should be noted that this by no means implies that their transportation needs are being met. Even in large communities and urban settlements, the transportation of goods and people relies mostly on ground transportation, with air transportation providing faster connections for higher valued travel.
For future studies, we recommend a deeper comparison of the costs and benefits of implementing a Northern Corridor with the existing air services.
Impact of climate change on northern air operations
A weather study conducted for 21 select airports using cloud ceiling data â one of the critical factors in determining the ability of pilots to land at an airport â showed no evidence of impact of climate change in airport operational availability over the last 17 years. At 60% of the airports, the number of annual inoperative hours shows a slight negative trend. In the summer, 60% of the airports have shown a slight increase in the number of inoperative hours, whereas in the winter the trend is mixed, with 50% of the airports with a negative trend and the other 50% showing a positive trend.
Flying an aircraft is a very complex operation that is affected by many factors. Climate change can affect not only cloud coverage but also runway visual range, precipitation (snow and rain), runway surface condition such as snow and ice, wind speed and direction, and other factors that can affect an aircraftâs ability to operate at an airport. However, most of these conditions are correlated. Although a deeper investigation may find stronger evidence that climate change has impacted airport operations in other ways, the fact that cloud ceiling was not found to be affected does not indicate that climate change has significantly affected air access to the Northern remote communities.
 
Air Connectivity and Airport Infrastructure in Northern Canada
To analyze the existing air transportation infrastructure that could potentially benefit from the Canadian Northern Corridor, a list of remote communities was obtained and investigated. A total of 182 communities have been assessed by Transport Canada or the provinces and territories, of which 146 are located inside the proposed Canadian Northern Corridor area. These communities are the focus of our study to answer the following questions:
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âą What is the current level of air transportation infrastructure and services?
âą What are the existing federal and territorial regarding northern and arctic air connectivity?
âą What is the potential impact of climate change on air transportation systems in northern Canada?
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Policies and Legislation
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In Canada, air transportation is regulated by the federal government. As such, there are no provincial or territorial policies regarding air transportation. Air transportation services in Canada are not subject to any economic regulations. Airlines and aircraft operators in general are free to set routes and fares as they wish â subject to operational safety regulations. As such, air services in the North are generally subject to supply and demand.
The Airport Transfer (Miscellaneous Matters) Act that created the National Airports System made no special provisions for airports in Northern Canada.
           The Civil Air Navigation Services Commercialisation Act transferred the operation of air navigation services to a private, not-for-profit corporation named NAV Canada. The act includes provisions for the continuance of air navigation services in northern and remote communities, requiring NAV Canada to give advance notice of any changes in service that could affect those communities. If the communities affected reject the proposed change, it will require approval by the Minister of Transportation.
           In 2016, the Government of Canada has initiated discussions to set a framework for a specific policy for Canadaâs Arctic and Northern Region. The work on that framework has identified better airport facilities as one of the key infrastructure needs in the region. To the time of writing of this report, no specific policies had been set to address these needs.
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Accessibility of Remote Communities to Nearby Airports
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140 of the 146 remote communities in this study are served by an airport nearby. Three communities are served by water aerodromes. Only three communities in BC were found to not have an airport or aerodrome nearby.
Most communities have paved and/or gravel road access to the airport. Communities which were identified with nearby airports have fair distances to their respective airports, ranging from 0 to 20 km. The exceptions are the remote communities of Keno, which is more than 50 km away from Mayo Airport in the Yukon; and Iskut, located 86 km from Dease Lake Airport.
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Airport Infrastructure
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           In general, the existing airport infrastructure provides adequate service to the remote communities in Northern Canada. Three of the 146 communities included in this study do not have access to a nearby airport, and three others can only be accessed by seaplanes. Two are accessible by road with distances between 50 and 90 km. All other 138 communities are served by an airport located within 20 km or less.
           Improvements may be required to several airports to ensure year-round, all-weather accessibility and convenience. 58% of the airports are not equipped for instrument flights and can only be used under visual flight conditions. It should be noted that the mere availability of instrument approach procedures does not guarantee service, as those procedures also require trained pilots and aircraft equipped with instruments. Only 85% of the runways are not paved, which affects aircraft maintenance and durability. 30% of the airports do not offer winter maintenance, which can affect their availability during and after snow and ice storms. 20% of the airports do not feature a terminal building, leaving the processing of passengers and cargo subject to inclement weather. The costs and benefits of such improvements are likely to vary from airport to airport and should be evaluated in more detail on a case-by-case basis.
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Air Connectivity
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Compared to other communities, the majority of the remote communities in the northern parts of the provinces are generally well connected, with scheduled services connecting them to regional and international airports. There are, however, several airports with limited or no commercial services. 18% of the airports in this study have no commercial services that connect them regularly to other communities. 7 airports are only served by charter services. Even in the case of the 109 airports that do have regularly scheduled services, the flights are infrequent and costly â it should be noted, however, that this study did not include an assessment of the prices of air tickets serving the Northern remote communities.
           One other limitation of this study is the absence of information on cargo and ambulance services. For the latter, the existing runway infrastructure â in terms of length and surface â is sufficient to accommodate aircraft with enough ranges to connect them to a larger airport and/or community. Cargo, however, is severely limited by the size of the aircraft that can operate on the existing runways. Only 44% of the airports can accommodate jet and larger turboprop aircraft. Once more, an economic analysis of cargo operations and the improvements required to improve them is beyond the scope of this study.
           This study is also limited to an evaluation of air services in Northern remote communities from a purely air services perspective. Even though a large portion of the communities have adequate services from that point of view, it should be noted that this by no means implies that their transportation needs are being met. Even in large communities and urban settlements, the transportation of goods and people relies mostly on ground transportation, with air transportation providing faster connections for higher valued travel.
For future studies, we recommend a deeper comparison of the costs and benefits of implementing a Northern Corridor with the existing air services.
Â
Impact of climate change on northern air operations
Â
A weather study conducted for 21 select airports using cloud ceiling data â one of the critical factors in determining the ability of pilots to land at an airport â showed no evidence of impact of climate change in airport operational availability over the last 17 years. At 60% of the airports, the number of annual inoperative hours shows a slight negative trend. In the summer, 60% of the airports have shown a slight increase in the number of inoperative hours, whereas in the winter the trend is mixed, with 50% of the airports with a negative trend and the other 50% showing a positive trend.
Flying an aircraft is a very complex operation that is affected by many factors. Climate change can affect not only cloud coverage but also runway visual range, precipitation (snow and rain), runway surface condition such as snow and ice, wind speed and direction, and other factors that can affect an aircraftâs ability to operate at an airport. However, most of these conditions are correlated. Although a deeper investigation may find stronger evidence that climate change has impacted airport operations in other ways, the fact that cloud ceiling was not found to be affected does not indicate that climate change has significantly affected air access to the Northern remote communities.
Regeneração medular: a ação do neurotrophin-3 sobre a lesão medular de ratos
OBJECTIVE: For many years, it was believed that medullary regeneration could not occur, although currently there are many trials using neurotrophic factors, stem cells, fetal medulla grafts, peripheral nerve grafts, and antibodies against myelin-associated proteins that demonstrate the existence of the possibility of spinal cord regeneration. The purpose of this study was to investigate the action of neurotrophin-3, a novel neurotrophic factor. METHODS: The New York University impactor, a standardized device for delivery of spinal cord injuries was used on 33 rats, which were divided into 2 groups: a control group receiving distilled water intraperitoneally and a treatment group receiving neurotrophin-3 intraperitoneally. RESULTS: Using the Basso, Beattie, and Bresnahan scale, the locomotor recovery curve for the neurotrophin-3 treated group was superior to that of the control group (P < 0.05); the administration of neurotrophin-3 was associated with the absence of deaths, while the control group showed a 28.5% (P = 0.026) mortality rate. Other parameters (hematuria rate and histological analysis) showed no significant differences. CONCLUSIONS: Based on these results, it appears that a strong relationship exists between the use of neurotrophin-3 in rats with spinal cord injury and better functional recovery.OBJETIVO: Por muitos anos acreditou-se que a regeneração medular nĂŁo fosse factĂvel. Atualmente porĂ©m, existem vĂĄrias experiĂȘncias utilizando fatores neurotrĂłficos, cĂ©lulas troncos, enxerto de medula fetal, enxerto de nervo perifĂ©rico e anticorpos contra proteĂnas associadas a mielina que sugerem o contrĂĄrio. Esta pesquisa estudou a ação de um dos mais novos neurotrĂłficos, o Neurotrophin-3. MĂTODOS: As lesĂ”es medulares foram realizadas atravĂ©s do New York University impator, mĂ©todo experimental de produção de lesĂŁo medular padronizada. Foram utilizados 33 ratos divididos em 2 grupos. Um grupo controle com administração intraperitoneal de ĂĄgua destilada e um grupo tratamento, tratado com Neurotrophin-3 por via intraperitoneal. RESULTADOS: Observamos que a curva de recuperação locomotora, segundo a escala de Basso, Beattie e Bresnahan, do grupo Neurotrophin-3 foi superior Ă do grupo controle (p < 0,05); a administração de Neurotrophin-3 determinou ausĂȘncia de mortes no grupo tratamento, enquanto o grupo controle apresentou taxa de mortalidade de 28,5% (p = 0,026). Os outros parĂąmetros (taxa de hematĂșria e anĂĄlise histolĂłgica) nĂŁo apresentaram diferenças estatisticamente significantes. CONCLUSĂES: Existe forte relação entre a aplicação de Neurotrophin-3 em ratos com lesĂŁo medular e melhor recuperação funcional
Fossil fuel and the global energy transition: regulation and standardisation as panacea for a more sustainable world energy order / O combustĂvel fĂłssil e a transição energĂ©tica global: regulação e normalização como panaceia para uma ordem energĂ©tica mundial mais sustentĂĄvel
The transition from fossil fuels to more sustainable sources of energy has become a topical issue that is likely to remain in the front burner of stakeholders as governments and businesses gradually move towards low-carbon economies. This move has been partly accelerated by the need to combat climate change and greenhouse gases (GHG). The move towards more sustainable energy sources has led to an upsurge in the number of international mechanisms such as the 2015 Paris Agreement on Climate Change (COP 15) (and a plethora of regional and domestic initiatives). Regulations and standardisation have been identified as strategic tools that can play critical roles in the drive towards energy transition. Regulation in this context refers to laws or other form of instruments with legal backing and having cohesiveness, while Standardisation entails the voluntary process of developing technical specifications based on consensus among stakeholders. The focus of this paper is how these two strategic tools interact and how they can be used to, enhance creativity, and further accelerate the drive towards energy transition and therefore more sustainable sources of energy.
Potencial reprodutivo de Spodoptera eridania (Stoll) (Lepidoptera: Noctuidae) em laboratĂłrio : efeito de mĂșltiplos casais e do tamanho
Este estudo objetivou avaliar o efeito de confinar trĂȘs casais em cada gaiola e o tamanho de adultos emergidos de pupas pequenas, medias e grandes (278,67 mg, 333,20 mg e 381,58 mg, respectivamente), sobre o potencial reprodutivo de S. eridania (Stoll, 1782), em condiçÔes controladas (25 ± 1 °C, 70% UR e 14 horas de fotofase). Avaliou-se a sobrevivĂȘncia, o nĂșmero de cĂłpulas, fecundidade e fertilidade dos adultos. A sobrevivĂȘncia nĂŁo diferiu significativamente entre fĂȘmeas provenientes de pupas de diferentes tamanhos, mas os machos oriundos de pupas grandes tiveram sobrevivĂȘncia significativamente menor que os demais tamanhos. A fecundidade diferiu significativamente e correlacionou-se positivamente com o tamanho. O nĂșmero de cĂłpulas (espematĂłforos) e a fertilidade nĂŁo variaram em função do peso pupal. Os resultados enfatizam a importĂąncia de indicar o nĂșmero de cĂłpulas e o tamanho dos insetos estudados para que comparaçÔes entre os parĂąmetros reprodutivos possam ser efetuadas.This study aimed to evaluate the effect of keeping three couples in the same cage, and the size of adults emerged from small, medium-sized and large pupae (278.67 mg; 333.20 mg and 381.58 mg, respectively), on the reproductive potential of S. eridania (Stoll, 1782) adults, under controlled conditions (25 ± 1 °C, 70% RH and 14 hour photophase). We evaluated the survival, number of copulations, fecundity and fertility of the adult females. The survival of females from these different pupal sizes did not differ statistically, but the survival of males from large pupae was statistically shorter than from small pupae. Fecundity differed significantly and correlated positively with size. The number of effective copulations (espematophores) and fertility did not vary significantly with pupal size. Our results emphasize the importance of indicating the number of copulations and the size of the insects when reproductive parameters are compared
A fibrin coating method of polypropylene meshes enables the adhesion of menstrual blood-derived mesenchymal stromal cells: a new delivery strategy for stem cell-based therapies
Polypropylene (PP) mesh is well-known as a gold standard of all prosthetic materials of choice for the reinforcement of soft tissues in case of hernia, organ prolapse, and urinary incontinence. The adverse effects that follow surgical mesh implantation remain an unmet medical challenge. Herein, it is outlined a new approach to allow viability and adhesion of human menstrual blood-derived mesenchymal stromal cells (MenSCs) on PP surgical meshes. A multilayered fibrin coating, based on fibrinogen and thrombin from a commercial fibrin sealant, was optimized to guarantee a homogeneous and stratified film on PP mesh. MenSCs were seeded on the optimized fibrin-coated meshes and their adhesion, viability, phenotype, gene expression, and immunomodulatory capacity were fully evaluated. This coating guaranteed MenSC viability, adhesion and did not trigger any change in their stemness and inflammatory profile. Additionally, MenSCs seeded on fibrin-coated meshes significantly decreased CD4+ and CD8+ T cell proliferation, compared to in vitro stimulated lymphocytes (p < 0.0001). Hence, the proposed fibrin coating for PP surgical meshes may allow the local administration of stromal cells and the reduction of the exacerbated inflammatory response following mesh implantation surgery. Reproducible and easy to adapt to other cell types, this method undoubtedly requires a multidisciplinary and translational approach to be improved for future clinical uses.This work was supported by: SANTANDER BANK: âConvenio de colaboraciĂłn empresarial en actividades de interĂ©s generalâ to F.M.; FUNDAĂĂO PARA A CIĂNCIA E A TECNOLOGIA
(FCT): post-doctoral contract CEECIND/01026/2018 to J.M.S.; INSTITUTO DE SALUD CARLOS
III (ISCIII): a âPFISâ contract (FI19/00041) to M.Ă.P., a âSara Borrellâ grant (CD19/00048) to E.L.;
a âMiguel Servet Iâ grant (MS17/00021), co-funded by the European Social Fund (ESF) âInvesting
in your futureâ, and projects CP17/00021 and PI18/0911, co-funded by the European Regional
Development Fund (ERDF) âA way to make Europeâ to J.G.C.; a âCIBERCVâ grant (CB16/11/00494),
co-funded by the ERDF to F.M.S.-M; JUNTA DE EXTREMADURA, CONSEJERĂA DE ECONOMĂA,
CIENCIA Y AGENDA DIGITAL: project IB20184 (co-funded by ERDF) to E.L. and M.P.; grant
GR18199, co-funded by the ERDF, to F.M.S.-M.; contracts TA18054 to I.J. and TA18011 to J.J.L. (cofinanced by FEDER)
APRENDIZAGEM BASEADA EM PROBLEMAS SOCIOAMBIENTAIS DE PIRACICABA
A interaçaÌo entre os municiÌpios e universidades pode fornecer poderosas ferramentas na resoluçaÌo de problemas socioambientais locais. Apresentamos aqui os processos de construçaÌo e os resultados de uma dessas formas de interaçaÌo. A disciplina Ecologia Aplicada eÌ destinada aos ingressantes do curso de CieÌncias BioloÌgicas da Escola Superior de Agricultura âLuiz de Queirozâ (ESALQ/USP), em Piracicaba, SaÌo Paulo. Nela, grupos de alunos, com a ajuda de um tutor e sempre monitorados pelos docentes responsaÌveis, trabalham na resoluçaÌo de problemas socioambientais, contando com a Aprendizagem Baseada em Problemas. No primeiro semestre de 2020, excepcionalmente, em contexto da pandemia da COVID-19, a disciplina foi oferecida a distaÌncia e sem as excursoÌes nas quais os problemas socioambientais a serem trabalhados seriam identificados. Para sua realizaçaÌo, o ambiente virtual da universidade foi fundamental em todas as etapas. A cada aluno foi pedido que identificasse questoÌes ambientais no municiÌpio de Piracicaba. Os docentes formaram grupos de alunos por afinidade de assunto. Cada grupo escolheu um problema ambiental a ser trabalhado durante o semestre. ApoÌs trabalharem com os tutores ao longo do semestre, os alunos propuseram resoluçoÌes a seus problemas ambientais. Os trabalhos foram considerados pelos docentes de alta qualidade, tendo muitos grupos chegado a resultados que podem futuramente se transformar em poliÌticas puÌblicas. Alguns grupos produziram material informativo aÌ sociedade, outros criaram perfis em redes sociais para comunicaçaÌo. A Aprendizagem Baseada em Problemas se mostrou vaÌlida para promover reflexoÌes e buscar soluçoÌes para problemas do municiÌpio
Wild dogs at stake: deforestation threatens the only Amazon endemic canid, the short-eared dog (Atelocynus microtis)
The persistent high deforestation rate and fragmentation of the Amazon forests are the main threats to their biodiversity. To anticipate and mitigate these threats, it is important to understand and predict how species respond to the rapidly changing landscape. The short-eared dog Atelocynus microtis is the only Amazon-endemic canid and one of the most understudied wild dogs worldwide. We investigated short-eared dog habitat associations on two spatial scales. First, we used the largest record database ever compiled for short-eared dogs in combination with species distribution models to map species habitat suitability, estimate its distribution range and predict shifts in species distribution in response to predicted deforestation across the entire Amazon (regional scale). Second, we used systematic camera trap surveys and occupancy models to investigate how forest cover and forest fragmentation affect the space use of this species in the Southern Brazilian Amazon (local scale). Species distribution models suggested that the short-eared dog potentially occurs over an extensive and continuous area, through most of the Amazon region south of the Amazon River. However, approximately 30% of the short-eared dog's current distribution is expected to be lost or suffer sharp declines in habitat suitability by 2027 (within three generations) due to forest loss. This proportion might reach 40% of the species distribution in unprotected areas and exceed 60% in some interfluves (i.e. portions of land separated by large rivers) of the Amazon basin. Our local-scale analysis indicated that the presence of forest positively affected short-eared dog space use, while the density of forest edges had a negative effect. Beyond shedding light on the ecology of the short-eared dog and refining its distribution range, our results stress that forest loss poses a serious threat to the conservation of the species in a short time frame. Hence, we propose a re-assessment of the short-eared dog's current IUCN Red List status (Near Threatened) based on findings presented here. Our study exemplifies how data can be integrated across sources and modelling procedures to improve our knowledge of relatively understudied species
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