760 resultados para signature of knowledge
Resumo:
Among the efforts for the improvement of agricultural productivity, the cultivation of useful plants is particularly at the center of the Economic Enlightenment. In contrast to fodder and textile plants, cereals and potatoes, fruit trees are not included among its favoured subjects. This may be considered as astonishing in view of the significance that fruit has acquired in the contemporary diet. Be that as it may, efforts to improve fruit cultivation go back to even before the classical period of the Economic Enlightenment. The example of Bern in particular is suited to such an analysis over the Longue durée that covers the time from Daniel Rhagor’s «Pflantz-Gart» (1639) to the «Register of varieties of excellent species of pome fruits for the canton of Bern» (Stammregister, 1865). From the perspective of the history of knowledge, the connections between scholarly knowledge and local experience on the one hand and the changing actors in these knowledge systems on the other hand are of special interest here
Resumo:
The objects of study in this thesis are knots. More precisely, positive braid knots, which include algebraic knots and torus knots. In the first part of this thesis, we compare two classical knot invariants - the genus g and the signature σ - for positive braid knots. Our main result on positive braid knots establishes a linear lower bound for the signature in terms of the genus. In the second part of the thesis, a positive braid approach is applied to the study of the local behavior of polynomial functions from the complex affine plane to the complex numbers. After endowing polynomial function germs with a suitable topology, the adjacency problem arises: for a fixed germ f, what classes of germs g can be found arbitrarily close to f? We introduce two purely topological notions of adjacency for knots and discuss connections to algebraic notions of adjacency and the adjacency problem.
Resumo:
The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature ("Core" OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this combinatorial stem cell niche is a novel mechanism that may also explain cancer cell osteotropism and local interference with hematopoiesis (myelophthisis). Accordingly, these stem cell niche components may represent innovative therapeutic targets and/or serum biomarkers in osteoblastic bone metastasis.
Resumo:
Better access to knowledge and knowledge production has to be reconsidered as key to successful individual and social mitigation and adaptation strategies for global change. Indeed, concepts of sustainable development imply a transformation of science towards fostering democratisation of knowledge production and the development of knowledge societies as a strategic goal. This means to open the process of scientific knowledge production while simultaneously empowering people to implement their own visions for sustainable development. Advocates of sustainability science support this transformation. In transdisciplinary practice, they advance equity and accountability in the access to and production of knowledge at the science–society interface. UNESCO points to advancements, yet Northern dominance persists in knowledge production as well as in technology design and transfer. Further, transdisciplinary practice remains experimental and hampered by inadequate and asymmetrically equipped institutions in the North and South and related epistemological and operational obscurity. To help identify clear, practicable transdisciplinary approaches, I recommend examining the institutional route – i.e., the learning and adaptation process – followed in concrete cases. The transdisciplinary Eastern and Southern Africa Partnership Programme (1998–2013) is a case ripe for such examination. Understanding transdisciplinarity as an integrative approach, I highlight ESAPP’s three key principles for a more democratised knowledge production for sustainable development: (1) integration of scientific and “non-scientific” knowledge systems; (2) integration of social actors and institutions; and (3) integrative learning processes. The analysis reveals ESAPP’s achievements in contributing to more democratic knowledge production and South ownership in the realm of sustainable development.
Resumo:
Better access to knowledge and knowledge production has to be reconsidered as key to successful individual and social mitigation and adaptation strategies for global change. Indeed, concepts of sustainable development imply a transformation of science (Lubchenco 1998; WBGU 2011 and 2012) towards fostering democratisation of knowledge production as a contribution to the development of knowledge societies as a strategic goal (UNESCO 2005). This means to open the process of scientific knowledge production while simultaneously empowering people to implement their own visions for sustainable development. Advocates of sustainability science support this transformation. In transdisciplinary practice, they advance equity and accountability in the access to and production of knowledge at the science–society interface (Hirsch Hadorn et al 2006; Hirsch Hadorn et al 2008; Jäger 2009; Adger and Jordan 2009; KFPE 2012). UNESCO (2010) points to advancements, yet Northern dominance persists in knowledge production as well as in technology design and transfer (Standing and Taylor 2007; Zingerli 2010). Further, transdisciplinary practice remains experimental and hampered by inadequate and asymmetrically equipped institutions in the North and South and related epistemological and operational obscurity (Wiesmann et al 2011). To help identify clear, practicable transdisciplinary approaches, I recommend examining the institutional route (Mukhopadhyay et al 2006) – i.e., the learning and adaptation process – followed in concrete cases. The transdisciplinary Eastern and Southern Africa Partnership Programme (1998–2013) is a case ripe for such examination. Understanding transdisciplinarity as an integrative approach (Pohl et al 2008; Stock and Burton 2011), I highlight ESAPP’s three key principles for a more democratised knowledge production for sustainable development: (1) integration of scientific and “non-scientific” knowledge systems; (2) integration of social actors and institutions; and (3) integrative learning processes. The analysis reveals ESAPP’s achievements in contributing to more democratic knowledge production and South ownership in the realm of sustainable development.
Resumo:
Since 1947, Australia has formally resettled more than 750,000 refugees. During that time, researchers have successfully completed more than 150 Masters and doctoral theses and published more than 900 articles, books and reports about issues of refugee settlement in Australia, with about half of them being published in the past 10 years. In this paper, we discuss the development of the production of knowledge about refugee resettlement. We identify trends in the literature, such as the emergence of an ethno-specific focus, and the concern with settlement's psychological and emotional impact, and relate them to policy changes. We suggest that scholars need critically to take stock of the knowledge produced so far and be more cognisant of the international scholarly debate.
Resumo:
Plants activate local and systemic defence mechanisms upon exposure to stress. This innate immune response is partially regulated by plant hormones, and involves the accumulation of defensive metabolites. Although local defence reactions to herbivores are well studied, less is known about the impact of root herbivory on shoot defence. Here, we examined the effects of belowground infestation by the western corn rootworm Diabrotica virgifera virgifera on aboveground resistance in maize. Belowground herbivory by D. v. virgifera induced aboveground resistance against the generalist herbivore Spodoptera littoralis, and the necrotrophic pathogen Setosphaeria turcica. Furthermore, D. v. virgifera increased shoot levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), and primed the induction of chlorogenic acid upon subsequent infestation by S. littoralis. To gain insight into the signalling network behind this below- and aboveground defence interaction, we compiled a set of 32 defence-related genes, which can be used as transcriptional marker systems to detect activities of different hormone-response pathways. Belowground attack by D. v. virgifera triggered an ABA-inducible transcription pattern in the shoot. The quantification of defence hormones showed a local increase in the production of oxylipins after root and shoot infestation by D. v. virgifera and S. littoralis, respectively. On the other hand, ABA accumulated locally and systemically upon belowground attack by D. v. virgifera. Furthermore, D. v. virgifera reduced the aboveground water content, whereas the removal of similar quantities of root biomass had no effect. Our study shows that root herbivory by D. v. virgifera specifically alters the aboveground defence status of a maize, and suggests that ABA plays a role in the signalling network mediating this interaction.