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Functional Criteria (functional + criterion)

Distribution by Scientific Domains

Humanities and Social Sciences	50%

Selected Abstracts

Exploration of the functional hierarchy of the basal layer of human epidermis at the single-cell level using parallel clonal microcultures of keratinocytes

EXPERIMENTAL DERMATOLOGY, Issue 4 2010
Nicolas O. Fortunel
Please cite this paper as: Exploration of the functional hierarchy of the basal layer of human epidermis at the single-cell level using parallel clonal microcultures of keratinocytes. Experimental Dermatology 2010. Abstract:, The basal layer of human epidermis contains both stem cells and keratinocyte progenitors. Because of this cellular heterogeneity, the development of methods suitable for investigations at a clonal level is dramatically needed. Here, we describe a new method that allows multi-parallel clonal cultures of basal keratinocytes. Immediately after extraction from tissue samples, cells are sorted by flow cytometry based on their high integrin-,6 expression and plated individually in microculture wells. This automated cell deposition process enables large-scale characterization of primary clonogenic capacities. The resulting clonal growth profile provided a precise assessment of basal keratinocyte hierarchy, as the size distribution of 14-day-old clones ranged from abortive to highly proliferative clones containing 1.7 × 105 keratinocytes (17.4 cell doublings). Importantly, these 14-day-old primary clones could be used to generate three-dimensional reconstructed epidermis with the progeny of a single cell. In long-term cultures, a fraction of highly proliferative clones could sustain extensive expansion of >100 population doublings over 14 weeks and exhibited long-term epidermis reconstruction potency, thus fulfilling candidate stem cell functional criteria. In summary, parallel clonal microcultures provide a relevant model for single-cell studies on interfollicular keratinocytes, which could be also used in other epithelial models, including hair follicle and cornea. The data obtained using this system support the hierarchical model of basal keratinocyte organization in human interfollicular epidermis. [source]

INTRA-REGIONAL EMPLOYMENT GROWTH IN LUXEMBOURG (1994,2005)

GEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 1 2010
Olivier Walther
ABSTRACT. The specialization of city-centres towards more advanced service activities has mostly been studied in the largest city-regions, the case of smaller urban centres being less well documented. In that context, the objective of this article is to analyse the role of sectoral and regional factors in employment growth in Luxembourg between 1994 and 2005. Using statistical data from the Luxembourg General Inspection of Social Security, this contribution distinguishes 12 categories of manufacturing industries and services according to an OECD-Eurostat knowledge-based classification. Five intra-regional areas are distinguished based on morphological and functional criteria in the Luxembourg Metropolitan Area. Using several indexes, this article first analyses the sectoral specialization and geographical concentration of employment. A model of intra-regional employment growth, initially developed by Marimon and Zilibotti and applied at the European level, is then shown to account for 40 per cent of employment growth. An estimation of the contributions of sectoral and geographical factors highlights the primacy of the latter over the former. Finally, the construction of virtual economies confirms the City's overall lower performance as compared to its close periphery. Results underscore a process of functional integration in the Luxembourg metropolitan area: as the core of the city undergoes a specialization process, the urban area benefits from a relocation of activities less sensitive to distance and transaction costs, while the periphery becomes increasingly diversified, notably in the South where traditional industrial activities are being replaced by service activities. These results suggest that the evolution pattern of employment growth in Luxembourg is very similar to that of some larger metropolitan centres, owing to its exceptional financial service activities. [source]

A framework for continuous design of production systems and its application in collective redesign of production line equipment

HUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 1 2002
Françoise Darses
The continuous design of production systems is a major challenge facing companies, and one that requires organization and systematization. This article describes one of the continuous design endeavors implemented in a factory manufacturing steel tubes. We have studied the collective redesign of production line equipment. For 2 years, we followed the operations of a multioccupational group composed of the various actors involved in manufacturing (including the operators). Their task was to redesign the tools used in their production line. Our analysis is focused on the cognitive side of the activity and especially on the collective redesign processes. From the transcripts of the meetings, we have examined how the codesigners come to an agreement about the redesigned equipment. We show that the criteria spontaneously used for the evaluation of the solution are far wider (quantitatively and qualitatively) than the list of functional criteria prescribed to the codesigners for the decision-making process. This analysis leads us to propose three conditions that have to be met to guarantee success: (a) a true systemic view of the production system must be developed by all the continuous design actors, (b) there must be support for the collective decision-making process, and (c) new forms of knowledge must be institutionalized. © 2002 John Wiley & Sons, Inc. [source]

THE CHALLENGE OF ,TECHNOLOGICAL CHOICES'FOR MATERIALS SCIENCE APPROACHES IN ARCHAEOLOGY,

ARCHAEOMETRY, Issue 1 2000
B. SILLAR
Recently several anthropological and sociological studies have interpreted technologies as cultural choices that are determined as much by local perceptions and the social context fly any material constraints or purely functional criteria. Using the example of ceramic technology we consider how materials science studies can contribute to and benefit from this understanding of technology as a social construct. Although we acknowledge some potential difficulties, it is our contention that both materials scientists and archaeologists have gained much and have much to gain by cooperating together to study ancient technologies, and that the concept of ,technological choices'can facilitate a wider consideration of the factors shaping technological developments. [source]