University of Groningen

About: University of Groningen is a education organization based out in Groningen, Groningen, Netherlands. It is known for research contribution in the topics: Population & Poison control. The organization has 36346 authors who have published 69116 publications receiving 2940370 citations. The organization is also known as: Rijksuniversiteit Groningen & RUG.

Software Architecture as a Set of Architectural Design Decisions

Abstract: Software architectures have high costs for change, are complex, and erode during evolution We believe these problems are partially due to knowledge vaporization Currently, almost all the knowledge and information about the design decisions the architecture is based on are implicitly embedded in the architecture, but lack a first-class representation Consequently, knowledge about these design decisions disappears into the architecture, which leads to the aforementioned problems In this paper, a new perspective on software architecture is presented, which views software architecture as a composition of a set of explicit design decisions This perspective makes architectural design decisions an explicit part of a software architecture Consequently, knowledge vaporization is reduced, thereby alleviating some of the fundamental problems of software architecture

Cancer stem cell definitions and terminology: the devil is in the details

Abstract: The cancer stem cell (CSC) concept has important therapeutic implications, but its investigation has been hampered both by a lack of consistency in the terms used for these cells and by how they are defined. Evidence of their heterogeneous origins, frequencies and their genomic, as well as their phenotypic and functional, properties has added to the confusion and has fuelled new ideas and controversies. Participants in The Year 2011 Working Conference on CSCs met to review these issues and to propose a conceptual and practical framework for CSC terminology. More precise reporting of the parameters that are used to identify CSCs and to attribute responses to them is also recommended as key to accelerating an understanding of their biology and developing more effective methods for their eradication in patients.

Band gap, excitons, and Coulomb interaction in solid C60.

Abstract: The band gap of solid ${\mathrm{C}}_{60}$ is found to be 2.3\ifmmode\pm\else\textpm\fi{}0.1 eV. The on-site molecular ${\mathrm{C}}_{60}$ Coulomb interaction (U) as determined from the KVV ${\mathrm{C}}_{60}$ Auger spectrum is found to be 1.6\ifmmode\pm\else\textpm\fi{}0.2 eV. This value of U is shown to lead to Frenkel-type molecular excitons in the 1.5--2 eV range. These results lead us to suggest that doped ${\mathrm{C}}_{60}$ should be considered as a highly correlated system with U/W comparable to that in high-${\mathit{T}}_{\mathit{c}}$ cuprates and that stoichiometric ${\mathrm{K}}_{3}$${\mathrm{C}}_{60}$ is a Mott-Hubbard insulator with a gap of about 0.7 eV.

Archaeological and palaeoecological indications of an abrupt climate change in The Netherlands, and evidence for climatological teleconnections around 2650 BP

Abstract: A sudden and sharp rise in the C-14 content of the atmosphere, which occurred between ca. 850 and 760 calendar yr BC (ca. 2750-2450 BP on the radiocarbon time-scale), was contemporaneous with an abrupt climate change. In northwest Europe (as indicated by palaeoecological and geological evidence) climate changed from relatively warm and continental to oceanic. As a consequence, the ground-water table rose considerably in certain low-lying areas in The Netherlands. Archaeological and palaeoecological evidence for the abandonment of such areas in the northern Netherlands is interpreted as the effect of a rise of the water table and the extension of fens and bogs. Contraction of population and finally migration from these low-lying areas, which had become marginal for occupation, and the earliest colonisation by farming communities of the newly emerged salt marshes in the northern Netherlands around 2550 BP, is interpreted as the consequence of loss of cultivated land. Thermic contraction of ocean water and/or decreased velocity and pressure on the coast by the Gulf Stream may have caused a fall in relative sea-level rise and the emergence of these salt marshes. Evidence for a synchronous climatic change elsewhere in Europe and on other continents around 2650 BP is presented. Temporary aridity in tropical regions and a reduced transport of warmth to the temperate climate regions by atmospheric and/or oceanic circulation systems could explain the observed changes. As yet there is no clear explanation for this climate change and the contemporaneous increase of C-14 in the atmosphere. The strategy of C-14 wiggle-match dating can play an important role in the precise dating of organic deposits, and can be used to establish possible relationships between changing C-14 production in the atmosphere, climate change, and the impact of such changes on hydrology, vegetation, and human communities.