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Related Elements (relate + element)

Distribution by Scientific Domains
Life Sciences50%

Selected Abstracts

Identification of regulatory elements involved in expression and induction by sucrose and UV-B light of the Arabidopsis thaliana COX5b-2 gene, encoding an isoform of cytochrome c oxidase subunit 5b

PHYSIOLOGIA PLANTARUM, Issue 3 2009
Raśl N. Comelli
The promoter sequences required for expression of the Arabidopsis thaliana COX5b-2 gene, encoding an isoform of cytochrome c oxidase subunit 5b, were analyzed using plants transformed with deleted and mutagenized forms of the promoter fused to gus. A 1000-bp promoter fragment produces expression in root and shoot meristems, leaf and cotyledon tips, and anthers. Deletion analysis indicated the presence of positive and negative regulatory elements. A regulatory element located between ,660 and ,620 from the translation start site was identified as a G-box by mutagenic analysis. Mutation of the G-box, that is present within the coding region of the preceding gene in the genome, increases expression of COX5b-2 in cotyledon and leaf lamina and abolishes induction by ultraviolet-B (UV-B) light, which presumably acts through the removal of an inhibitory factor. Identified positive regulatory elements include a site II element (TGGGCC), a related element with the sequence TGGGTC and four initiator elements (YTCANTYY) that completely abolish expression when mutated in combination. Site II elements are also involved in the response to sucrose. The results imply that the COX5b-2 gene has retained expression characteristics presented by most respiratory chain component genes, but its expression mechanisms have diverged from those employed by COX5b-1, the other gene encoding cytochrome c oxidase subunit 5b in Arabidopsis. [source]

Knowledge Life Cycle, Knowledge Inventory, and Knowledge Acquisition Strategies,

DECISION SCIENCES, Issue 1 2010
Andrew N. K. Chen
ABSTRACT For a knowledge- and skill-centric organization, the process of knowledge management encompasses three important and closely related elements: (i) task assignments, (ii) knowledge acquisition through training, and (iii) maintaining a proper level of knowledge inventory among the existing workforce. Trade-off on choices between profit maximization in the short run and agility and flexibility in the long term is a vexing problem in knowledge management. In this study, we examine the effects of different training strategies on short-term operational efficiency and long-term workforce flexibility. We address our research objective by developing a computational model for task and training assignment in a dynamic knowledge environment consisting of multiple distinct knowledge dimensions. Overall, we find that organizational slack is an important variable in determining the effectiveness of training strategies. Training strategies focused on the most recent skills are found to be the preferred option in most of the considered scenarios. Interestingly, increased efficiencies in training can actually create preference conflict between employees and the firm. Our findings indicate that firms facing longer knowledge life cycles, higher slack in workforce capacity, and better training efficiencies actually face more difficult challenges in knowledge management. [source]

A new fate for old cells: brush cells and related elements

JOURNAL OF ANATOMY, Issue 4 2005
A. Sbarbati
Abstract Over the past 50 years, hundreds of studies have described those cells that are characterized by a brush of rigid apical microvilli with long rootlets, and which are found in the digestive and respiratory apparatuses. These cells have been given names such as brush cells, tuft cells, fibrillovesicular cells, multivesicular cells and caveolated cells. More recently, it has been realized that all these elements may represent a single cell type, probably with a chemosensory role, even if other functions (e.g. secretory or absorptive) seem to be possible. Very recent developments have permitted a partial definition of the chemical code characterizing these elements, revealing the presence of molecules involved in chemoreceptorial cell signalling. A molecular cascade, similar to those characterizing the gustatory epithelium, seems to be present in these elements. These new data suggest that these elements can be considered solitary chemosensory cells with the presence of the apical ,brush' as an inconsistent feature. They seem to comprise a diffuse chemosensory system that covers large areas (probably the whole digestive and respiratory apparatuses) with analogies to chemosensory systems described in aquatic vertebrates. [source]

Alienation and obligation: Religion and social change in Samoa

ASIA PACIFIC VIEWPOINT, Issue 1 2010
Alec Thornton
Abstract This paper will explore social change in contemporary Samoan society with respect to the traditional expectations of the church and kinship conflicting with the modern needs of an urbanising population. In the Samoan way of life , the fa'aSamoa , religion, matai (chiefly system) and reciprocal ,gift-giving' kinship arrangements among the aiga (extended family) are fundamental and closely related elements. However, pressures from continued integration into the global economy, the importance of remittance income and related migration of well-educated and highly skilled Samoans overseas are presenting several challenges to the strongly held traditions of kinship and church obligations. Among these challenges, low-income households are increasingly placing the material well-being of the immediate household first, thus ,opting out' of the culturally defined primary obligation to the church and risk alienation from beneficial familial ties. As a result, settlement patterns are shifting towards leaseholds in urbanising Apia, with consequences, we will speculate, that may have deeper cultural implications. Our research revealed that the church has been slow to accept that, increasingly, Samoans are seeking relief from hardships that spirituality alone cannot address. However, given its influence, strengths and resources, the church is well positioned to take a lead role in facilitating opportunities for ,bottom-up', alternative development in Samoa, as well as providing lessons for church-led participatory approaches in the Pacific Island Region. [source]