180 research outputs found
Boosting potato defence against late blight
Full text linkFor more than one century efforts has been made to obtain potato (Solanum tuberosum) cultivars resistant to late blight. However, introduced resistance has repeatedly been overcome by Phytophthora infestans (Mont) de Bary. Today late blight control is dependent on the frequent use of fungicides, but development of fungicide resistance and increasing fungicide restrictions by EU are of major concern. Methods with less fungicide requirement is therefore of crucial importance for a more environmentally sound and sustainable late blight control in the future.
In this study the potential of integrating BABA-induced resistance in existing late blight management with fungicides was investigated in field. The fungicide dose could be lowered with up to 25% when combined with BABA, without any decrease in late blight control or metabolic cost in terms of tuber yield. BABA was shown to directly activate basal defence responses and hormone signaling in potato. The BABA-induced hypersensitive-like lesions and major changes in the amino acid balance indicate that BABA induces resistance by stress imprinting.
Furthermore the potential of using a biosurfactant, produced by Psuedomonas koreensis strain 2.74, to control late blight in greenhouse was demonstrated. The biosurfactant was shown to have a direct effect on zoospores and also to induce PR-1 accumulation in the apoplast of potato leaves. Future experiments will reveal if the biosurfactant induces other defence mechanisms in potato.
This study demonstrated how integration of different control methods could lead to unchanged or even improved late blight control despite the decrease in fungicide dose
[Essai] Daniel C. Blight "Be it in light or shadow: Photography and the Essay"
No full textWilliam Henry Fox Talbot, "A Scene in a Library", from The Pencil of Nature, Part 2, Plate 8, January 1845 Daniel C. Blight est professeur d’études historiques et critiques de la photographie à l’Université de Brighton (Angleterre) et co-éditeur de Loose Associations, un périodique sur la culture de l'image, publié par The Photographers’ Gallery. Il vient de publier un article intitulé « Be it in light or shadow: Photography and the Essay » où il réfléchit à la relation spécifique entre la p..
Biological control of chestnut blight. Detection, identification and characterization of the Hypovirus - CHV1
No full textO cancro do castanheiro é provocado pelo fungo Cryphonectria parasitica é considerado a principal causa do declínio dos castanheiros na Europa. C. parasitica é um ascomiceta (Diaporthales) nativo do continente asiático. A infeção do castanheiro manifesta-se pelo aparecimento de necroses extensas na casca dos ramos e troncos, que resulta na morte dos
castanheiros. A hipovirulência é um método seletivo de controlo biológico do Cancro do Castanheiro, trata-se de uma infeção do fungo C. parasitica com Cryphonectria hypovirus 1 (CHV1), um vírus de dsRNA não encapsulado do género Hypovirus. O controlo biológico com estirpes hipovirulentas é considerado um método eficaz no controlo da doença e promove a recuperação dos castanheiros. A aplicação necessita da produção em laboratório de estirpes hipovirulentas compatíveis com a estirpe virulenta presente no campo e a sua introdução na margem de cancros ativos. Neste estudo pretendeu-se detetar, identificar e caracterizar o hipovirus CHV1 com potencial para integrar programas de controlo biológico do Cancro do castanheiro em Portugal. Com a utilização de métodos moleculares foram identificados e caracterizados 11 hipovirus em isolados brancos de C. parasitica obtidos em cancros no nordeste de Portugal.The chestnut blight caused by the fungus Cryphonectria parasitica is considered a major cause of the decline and disappearance
of chestnut trees across Europe. C. parasitica is an ascomycete fungus (Diaporthales) that is native to eastern
Asia. Infection of chestnut plants with this fungus is typically associated with extensive necrosis (cankers) of the bark
on stems and branches, resulting in the subsequent death of the tree. Hypovirulence is a specific method for biological
control of Chestnut Blight, it is an infection of C. parasitica with Cryphonectria hypovirus 1 (CHV1), a unencapsidate
dsRNA virus of the genus Hypovirus. Biological control with hypovirulent strains is considered an efficient method to
control the disease and improve the host plant recovery. The field application needs laboratorial production of compatible
hypovirulent strain and introduction by inoculation at the margin of active cankers. In this work it was intended to
identify and characterize the hypovirus with potential ability to integrate biological control programmes against Chestnut
Blight. Using molecular techniques 11 hypovirus with hypovirulence potential were identified on white isolates of
C. parasitica isolated on cankers from northeast of Portugal
Fighting blight in Philadelphia
Full text linkThesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 139-145).Blight has plagued Philadelphia for the better part of a century, though the understanding of blight has changed dramatically over time. Originally used to describe neighborhood overcrowding, the term retained its currency even as once-overcrowded neighborhoods emptied out in the decades after World War II. The agenda of eradicating blight in its various forms has driven successive waves of redevelopment policy since the 1940s, and yet the problem persists to an astonishing degree in neighborhoods throughout the City. The "image" as a transformative planning tool is another concept with sustained significance in Philadelphia. This thesis defines an image as the vehicle for communicating a compelling idea about urban form that shapes broader understandings of place, and that serves as a catalyst of, and a framework for, individual and collective action. The importance of an image is best captured in longtime Director of the Philadelphia City Planning Commission (1949- 70) Edmund Bacon's declaration that "it is the image, not the planner, which has the power." Admittedly a slippery concept, the presence or absence of a strong image has consistently circumscribed the public reception and subsequent implementation of Philadelphia's redevelopment strategies. This thesis is an examination of Philadelphia's recent history of redevelopment through the dual lenses of blight and image. Noting a repeated vacillation between neighborhood-scaled design strategies and abstracted citywide analysis in the mid- and late-twentieth century, it posits the need for a flexible image, conceived at an intermediate scale.by Jonah Daniel Stern.M.C.P
"A hell of a storm": the Kansas-Nebraska act and the birth of the republican party, 1854-55 [The civil war and reconstruction era, 1845-1877]
No full textEducação Superior::Ciências Humanas::HistóriaPresents a course about the causes, course, and consequences of the American Civil War, from the 1840s to 1877 with the Professor of American History and Director of the Gilder Lehrman Center for the Study of Slavery, Resistance and Abolition at Yale University, David W. Blight. In this class the professor talks about some importants political events to the outbreak of Civil War in America. He mentions a few persons that had a leading role in this war, such as: Henry Clay, Daniel Webster, and John C. Calhoun. He also talks about the Kansas-Nebraska Act of 1854, wich represents the birth of the Republican part
"A hell of a storm": the Kansas-Nebraska act and the birth of the republican party, 1854-55 [The civil war and reconstruction era, 1845-1877]
No full textEducação Superior::Ciências Humanas::HistóriaPresents a course about the causes, course, and consequences of the American Civil War, from the 1840s to 1877 with the Professor of American History and Director of the Gilder Lehrman Center for the Study of Slavery, Resistance and Abolition at Yale University, David W. Blight. In this class the professor talks about some importants political events to the outbreak of Civil War in America. He mentions a few persons that had a leading role in this war, such as: Henry Clay, Daniel Webster, and John C. Calhoun. He also talks about the Kansas-Nebraska Act of 1854, wich represents the birth of the Republican part
"A hell of a storm": the Kansas-Nebraska act and the birth of the republican party, 1854-55 [The civil war and reconstruction era, 1845-1877]
No full textEducação Superior::Ciências Humanas::HistóriaPresents a course about the causes, course, and consequences of the American Civil War, from the 1840s to 1877 with the Professor of American History and Director of the Gilder Lehrman Center for the Study of Slavery, Resistance and Abolition at Yale University, David W. Blight. In this class the professor talks about some importants political events to the outbreak of Civil War in America. He mentions a few persons that had a leading role in this war, such as: Henry Clay, Daniel Webster, and John C. Calhoun. He also talks about the Kansas-Nebraska Act of 1854, wich represents the birth of the Republican part
"A hell of a storm": the Kansas-Nebraska act and the birth of the republican party, 1854-55 [The civil war and reconstruction era, 1845-1877]
No full textEducação Superior::Ciências Humanas::HistóriaPresents a course about the causes, course, and consequences of the American Civil War, from the 1840s to 1877 with the Professor of American History and Director of the Gilder Lehrman Center for the Study of Slavery, Resistance and Abolition at Yale University, David W. Blight. In this class the professor talks about some importants political events to the outbreak of Civil War in America. He mentions a few persons that had a leading role in this war, such as: Henry Clay, Daniel Webster, and John C. Calhoun. He also talks about the Kansas-Nebraska Act of 1854, wich represents the birth of the Republican part
Stranger Than Fiction
No full textStranger than fiction presents a selection of work by six artists from the Photography Research Group at the University of Brighton; Holly Birtles, Daniel C. Blight, Zoe Childerley, Fergus Heron, Asa Johannesson and Martin Seeds. With individual practices that engage with diverse themes, common to this exhibition is a set of tensions between the real and the imagined that the work of these artists can be seen to form. Building upon traditional genres of portraiture, landscape and still life, moving beyond straightforward notions of constructed and documentary approaches, the exhibition embraces the essential strangeness of photography to alternatively comment upon contemporary social experiences, see places as they might seem to appear, or evoke uncanny visions of worlds yet to be. The exhibition curation process situated works in dialogue with each other in a sequence around the gallery, moving from enigmatic to mimetic works, making their differences and common features newly visible
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