6 research outputs found
Cytotoxic CD4(+) T Cell Responses to EBV Contrast with CD8 Responses in Breadth of Lytic Cycle Antigen Choice and in Lytic Cycle Recognition
No full textEBV, a B lymphotropic herpesvirus, encodes two immediate early (IE)-, > 30 early (E)-, and > 30 late (L)-phase proteins during its replication (lytic) cycle. Despite this, lytic Ag-induced CD8 responses are strongly skewed toward IE and a few E proteins only, all expressed before HLA I presentation is blocked in lytically infected cells. For comparison, we examined CD4(+) T cell responses to eight IE, E, or L proteins, screening 14 virus-immune donors to overlapping peptide pools in IFN-gamma ELISPOT assays, and established CD4(+) T cell clones against 12 defined epitopes for target-recognition assays. We found that the lytic Ag-specific CD4(+) T cell response differs radically from its CD8 counterpart in that it is widely distributed across IE, E, and L Ag targets, often with multiple reactivities detectable per donor and with IE, E, or L epitope responses being numerically dominant, and that all CD4(+) T cell clones, whether IE, E, or L epitope-specific, show strong recognition of EBV-transformed B cell lines, despite the lines containing only a small fraction of lytically infected cells. Efficient recognition occurs because lytic Ags are released into the culture and are acquired and processed by neighboring latently infected cells. These findings suggested that lytic Ag-specific CD4 responses are driven by a different route of Ag display than drives CD8 responses and that such CD4 effectors could be therapeutically useful against EBV-driven lymphoproliferative disease lesions, which contain similarly small fractions of EBV-transformed cells entering the lytic cycle. The Journal of Immunology, 2011, 187: 92-101
Pollination ecology of the invasive tree tobacco Nicotiana glauca: comparisons across native and non-native ranges
No full textInteractions with pollinators are thought to play a significant role in determining whether plant species become invasive, and ecologically generalised species are predicted to be more likely to invade than more specialised species. Using published and unpublished data we assessed the floral biology and pollination ecology of the South American native Nicotiana glauca (Solanaceae) which has become a significant invasive of semi-arid parts of the world. In regions where specialised bird pollinators are available, for example hummingbirds in California and sunbirds in South Africa and Israel, N. glauca interacts with these local pollinators and sets seed by both out-crossing and selfing. In areas where there are no such birds, such as the Canary Islands and Greece, abundant viable seed is set by selfing, facilitated by the shorter stigma-anther distance compared to plants in native populations. Surprisingly, in these areas without pollinating birds, the considerable nectar resources are only rarely exploited by other flower visitors such as bees or butterflies, either legitimately or by nectar robbing. We conclude that Nicotiana glauca is a successful invasive species outside of its native range, despite its functionally specialised hummingbird pollination system, because it has evolved to become more frequently self pollinating in areas where it is introduced. Its invasion success is not predictable from what is known of its interactions with pollinators in its home range
Pollination ecology of the invasive tree tobacco Nicotiana glauca: comparisons across native and non-native ranges
No full textInteractions with pollinators are thought to play a significant role in determining whether plant species become invasive, and ecologically generalised species are predicted to be more likely to invade than more specialised species. Using published and unpublished data we assessed the floral biology and pollination ecology of the South American native Nicotiana glauca (Solanaceae) which has become a significant invasive of semi-arid parts of the world. In regions where specialised bird pollinators are available, for example hummingbirds in California and sunbirds in South Africa and Israel, N. glauca interacts with these local pollinators and sets seed by both out-crossing and selfing. In areas where there are no such birds, such as the Canary Islands and Greece, abundant viable seed is set by selfing, facilitated by the shorter stigma-anther distance compared to plants in native populations. Surprisingly, in these areas without pollinating birds, the considerable nectar resources are only rarely exploited by other flower visitors such as bees or butterflies, either legitimately or by nectar robbing. We conclude that Nicotiana glauca is a successful invasive species outside of its native range, despite its functionally specialised hummingbird pollination system, because it has evolved to become more frequently self pollinating in areas where it is introduced. Its invasion success is not predictable from what is known of its interactions with pollinators in its home range
Pollination ecology of the invasive tree tobacco Nicotiana glauca : comparisons across native and non-native ranges
No full textCITATION: Ollerton, J. et al 2012. Pollination ecology of the invasive tree tobacco Nicotiana glauca : comparisons across native and non-native ranges. Journal of Pollination Ecology, 9:85–95, doi:10.26786/1920-7603(2012)12.The original publication is available at https://pollinationecology.orgInteractions with pollinators are thought to play a significant role in determining whether plant species become invasive, and ecologically generalised species are predicted to be more likely to invade than more specialised species. Using published and unpublished data we assessed the floral biology and pollination ecology of the South American native Nicotiana glauca (Solanaceae) which has become a significant invasive of semi-arid parts of the world. In regions where specialised bird pollinators are available, for example hummingbirds in California and sunbirds in South Africa and Israel, N. glauca interacts with these local pollinators and sets seed by both out-crossing and selfing. In areas where there are no such birds, such as the Canary Islands and Greece, abundant viable seed is set by selfing, facilitated by the shorter stigma-anther distance compared to plants in native populations. Surprisingly, in these areas without pollinating birds, the considerable nectar resources are only rarely exploited by other flower visitors such as bees or butterflies, either legitimately or by nectar robbing. We conclude that Nicotiana glauca is a successful invasive species outside of its native range, despite its functionally specialised hummingbird pollination system, because it has evolved to become more frequently self pollinating in areas where it is introduced. Its invasion success is not predictable from what is known of its interactions with pollinators in its home range.https://pollinationecology.org/index.php/jpe/article/view/189Publisher's versio
Prospectus, April 13, 1978
No full textALBIN, HOOD, O\u27DELL ON BOARD; Letters to the editor: Bio teachers: science and religion don\u27t mix, Our last chance for wilderness, Spring cleaning applies to the outdoor litter, too; Tax deadline hours away: avoid mistakes; Bradley U. to host transfer day; Pre-registration begins April 17; King still reigns this weekend; Parkland College News in brief: Open House has events for you..., ...and for the kiddies, Student art displayed here, Career night, H.S. math contest here, AFROTC scholarships, ROTC rep here, WPCD rocks Friday; Osgood gives grad talk; Safety tips for cycle riders; Accidents increase during spring; Alice: a special type of children\u27s story; Wonderland! Kids only? Nonsense!; Isolation and fear for life: Battered women share common horrors; Portrayals photo show marks 1st at Krannert; Nautilus (arrgh!) good for what (aieee!!) ails you; More events this semester: Women\u27s program is recognized statewide; Day Senators have day for discussion; Parkland is more than \u27just another school\u27; Clubs have something for everyone; Tube menu \u27terribly narrow\u27 Children need games, not TV; 300,000 at work today: Computers shrink in size as uses grow; 100th anniversary: Sandburg collection at U of I; Experts wrong, baby boom fizzles; Gates of Paradise restored by U. of I.; Parkland people keep on dancing, caring; Classifieds; Trampolines have ups and downs as national pros discuss dangers; On the merry-go-round; Author at kids workshop; Beware this pretty poison that grows in your garden; Cobras can\u27t score, lose three of four; Women win two, even record; Tracksters put in \u27good performance\u27; New Cobra coach soon?; Stand back! It\u27s recruiting time
Additional material: IMAGES literary magazinehttps://spark.parkland.edu/prospectus_1978/1018/thumbnail.jp
Shrouded in darkness : a phenomenological path towards a new social ontology in international relations
No full textThe thesis sets out to critique recent accounts dealing with the notion and role of ontology in IR theorising as it can be found, for instance, in Alexander Wendt and more recently in the writings of critical realists. The main aim of these treatises on ontology is to provide a new perspective for IR theory that is in line with a more general critique of epistemological foundationalism and strict empiricism. Thereby these accounts rely upon an interpretation of scientific realism as it can be found in the Philosophy of Science.
The thesis shows how these approaches to ontology on the one hand overcome epistemological foundationalism but, on the other hand, reaffirm a form of ontological foundationalism through the apodictic positing of ‘intransitive objects’ that exist outside and independent of the human mind. Such an approach, rather than leading to a new and better conception of ontology, reifies the same biases of Cartesian subjectivity, the designative nature of language, a correspondence theory of truth and the problem-laden concept of freedom as it was conceived in Kant’s third antinomy. In response to these approaches whose general aim at reconceptualising ontology must be welcomed, the thesis develops a new approach that does not recreate the same problems in a different fashion but tries to overcome them through a reconceptualisation of the term ontology itself. The basis for the thesis is to be found in post-Husserlian phenomenology, a body of literature that has so far been widely ignored in IR theorising. By explicating the main tenets in the thought of such eminent philosophers as Heidegger, Gadamer, Merleau-Ponty and Ricoeur the thesis reconstructs the notion of ontology on the basis of an enquiry into the meaning of being in general and human being in particular. From this perspective a new approach to the notions of agency, language, truth and freedom becomes possible without recreating the rifts and foundationalisms that characterises many approaches to social and political relations
