Lancaster University

About: Lancaster University is a education organization based out in Lancaster, Lancashire, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 13080 authors who have published 44563 publications receiving 1692277 citations. The organization is also known as: The University of Lancaster & Lancaster University.

Local and long-range signaling pathways regulating plant responses to nitrate

Abstract: ▪ Abstract Nitrate is the major source of nitrogen (N) for plants growing in aerobic soils. However, the NO3− ion is also used by plants as a signal to reprogram plant metabolism and to trigger changes in plant architecture. A striking example is the way that a root system can react to a localized source of NO3− by activating the NO3− uptake system and proliferating lateral roots preferentially within the NO3−-rich zone. That roots are able to respond autonomously in this fashion implies the existence of local signaling pathways that are sensitive to local changes in the external NO3− concentration. On the other hand, long-range signaling pathways are also needed to modulate these responses according to the plant's N status and to coordinate the allocation of resources between the root and the shoot. This review examines these signaling mechanisms and their interactions with sugar-sensing and hormonal response pathways.

Uniqueness of place and process representations in hydrological modelling

Abstract: . This paper addresses the problem of uniqueness of catchment areas in relation to model representations of flow processes. The uniqueness of field measurements as a limitation on model representations is discussed. The treatment of uniqueness as a residual from a modelled relationship may conceal information about the uniqueness of catchments, while the treatment of uniqueness as a set of parameter values within a particular model structure is problematic due to the equifinality of model structures and parameter sets. The analysis suggests that a fully reductionist approach to describe the uniqueness of individual catchment areas by the aggregation of descriptions of small scale behaviour will be impossible given current measurement technologies. A suggested strategy for the representation of uniqueness of place as a fuzzy mapping of the landscape into a model space is suggested. This will lead to a quantification of the uncertainty in predictions of any particular location in a way that allows a conditioning of the mapping on the basis of the available data. This process can incorporate a hypothesis testing approach to model evaluation but the problem of multiple behavioural models may provide an ultimate limitation on the realism of process representations: not on the principle of realism but on the possibility of unambiguous process representations.

From key words to key semantic domains

Abstract: This paper reports the extension of the key words method for the comparison of corpora. Using automatic tagging software that assigns part-of-speech and semantic field (domain) tags, a method is described which permits the extraction of key domains by applying the keyness calculation to tag frequency lists. The combination of the key words and key domains methods is shown to allow macroscopic analysis (the study of the characteristics of whole texts or varieties of language) to inform the microscopic level (focussing on the use of a particular linguistic feature) and thereby suggesting those linguistic features which should be investigated further. The resulting 'data-driven' approach presented here combines elements of both the 'corpus-based' and 'corpus-driven' paradigms in corpus linguistics. A web-based tool, Wmatrix, implementing the proposed method is applied in a case study: the comparison of UK 2001 general election manifestos of the Labour and Liberal Democratic parties.

Situating Technoscience: An Inquiry into Spatialities

Abstract: This paper explores the spatial characteristics of science and technology. Originally seen as universal, and therefore outside space and place, studies in science, technology, and society (STS) located it first in specific locations -- laboratories -- and then in narrow networks linking laboratories. This double location implied that science is caught up in and enacts two topological forms -- region and network -- since objects in networks hold their shape by freezing relations rather than fixing Euclidean coordinates. More recent STS work suggests that science and technology also exist in and help to enact additional spatial forms. Thus some technoscience objects are fluid, holding their form by shifting their relations. And yet others achieve constancy by enacting simultaneous absence and presence, a topological possibility which we call here fire . The paper concludes by arguing that the 'global' includes and is enacted in all four of these topological systems.

Big-bang nucleosynthesis and gravitinos

Abstract: We derive big-bang nucleosynthesis (BBN) constraints on both unstable and stable gravitino taking account of recent progress in theoretical study of the BBN processes as well as observations of primordial light-element abundances In the case of unstable gravitino, we set the upper limit on the reheating temperature assuming that the primordial gravitinos are mainly produced by the scattering processes of thermal particles For stable gravitino, we consider B-ino, stau, and sneutrino as the next-to-the-lightest supersymmetric particle and obtain constraints on their properties Compared with the previous works, we improved the following points: (i) we use the most recent observational data, (ii) for gravitino production, we include contribution of the longitudinal component, and (iii) for the case with unstable long-lived stau, we estimate the bound-state effect of stau accurately by solving the Boltzmann equation