Modeling of oligomeric-state dependent spectral heterogeneity in the B875 light-harvesting complex of Rhodobacter sphaeroides by numerical simulation

A series of detergent-isolated light-harvesting 1 (LH1, B875) complexes from Rhodobacter sphaeroides, estimated to range in size from (RâBChl2)4 to (RâBChl2)13, was used to study the combined effects of spectral disorder and excitonic interactions on oligomeric-state dependent optical properties. Numerical simulations of absorption and fluorescence emission, excitation, and polarization spectra, based on the structure of the related LH2 complex, were compared to spectra measured experimentally at 77 K (Westerhuis and Niederman, in preparation). The aggregation-state dependence of the polarization spectra was found to be particularly sensitive to the choice of parameters, and vibronic components were included to obtain satisfactory simulations. Good agreement with most experimental features, including the oligomeric-state dependence of the absorption and emission maxima, was obtained only when the inter- and intradimer coupling strengths for adjacent BChls were similar (200-260 cm-1), and the width for the inhomogeneous distribution function (300-400 cm-1) was comparable. The relevance of these findings to existing controversies on the physical origin of spectral heterogeneity observed for the LH1 complex is discussed

Advancing the Age of Cycling

In the Netherlands, the number of older cyclists is increasing. This is desirable because cycling supports healthy ageing and personal independence. Older cyclists, however, run relatively large risks on (single) bicycle crashes. The goal of this thesis is to explore which parts of the infrastructure and (on-road) interactions lead to problems for older cyclists and, thereafter, to test the effectiveness of infrastructural and on-bicycle interventions to increase safety. ‘Everyday cycling’ observations of older cyclists revealed that obstacles, irregular surfaces, sharp corners, slopes, and narrow paths may cause difficulties. Some cyclists were also observed to (unintentionally) ride into the verge. Predicting the behaviour of other cyclists was also found to be difficult. At different locations, the effects of virtual 3D-objects, edge lines, slanted kerbstones, shoulder strips, and edge strips on cycling behaviour of older cyclists were measured. With small GPS action-cameras mounted on older participant’s bicycles, on-site experiments revealed that shoulder strips and edge strips were the most beneficial interventions for safety: at cycle paths with these modifications, participants rode further away from the soft verge compared to other (control) paths. They also cycled slower on the cycle paths with shoulder strips. Lastly, effects of using bicycle lights to communicate speed, braking, and turning intentions to other road users were investigated. The results showed that the tested speed signal was not effective. The turning indicator and brake light, however, seem useful for older cyclists

Comparative VET European Research since the 1980s: Accommodating Changes in VET Systems and Labour Markets

The article assesses the role comparative research plays from the 1980s in understanding vocational education and training (VET) systems in Europe, driven by political, economic, social and labour market changes. This research has been transformed, moving from national comparisons of VET systems, grounded in institutional theory and engaging with convergence versus divergence debates or human capital theory, to the varieties of capitalism approach considering groups of countries as representative of particular capitalist economies, to transcending national boundaries and emphasising capitalist diversity, governance and labour agency. Drawing on examples of research in which the authors and others have been involved, particularly on the construction industry, the article traces this development and shows how, despite governance weaknesses, comparative research has been enriched by the addition of a European Union level through the introduction of tools, such as the European Qualifications Framework. Four dimensions are proposed - labour market, governance, education and competence - capable of identifying VET 'families' and intra-national variations and capturing the dynamics of VET systems. Through a multi-dimensional and multi-level framework, comparative VET research can provide a deeper understanding of how and why VET systems respond to the challenges of technological, economic and environmental change

Міжнародний пакт «Про економічні, соціальні і культурні права»

Paper voor ORD 2014 In deze reviewstudie wordt de positie van het voorbereidend middelbaar beroepsonderwijs (vmbo) geanalyseerd als deel van het onderwijsbestel zowel in relatie tot de eerste fase voortgezet onderwijs als in relatie tot de beroepsonderwijskolom. De dualiteit van het vmbo wordt beschouwd ten aanzien van ontwikkelingen in maatschappelijke doelen, keuze- en selectieprocessen, inrichtingskenmerken en deelnamepatronen. Er wordt een historisch perspectief gehanteerd, niet zozeer voor een descriptief overzicht maar om inzicht te krijgen in de ontwikkelingen. Aanvullend vindt een internationale vergelijking plaats met enkele onderwijsstelsels die dezelfde of juist andere kenmerken hebben. Is de meervoudige positie van het vmbo al dan niet herkenbaar in andere stelsels, welke horizontale en verticale verbindingen zijn elders aanwezig, hoe zijn deelnameontwikkelingen vervolgens te begrijpen

Genetic algorithm based two-mode clustering of metabolomics data

Metabolomics and other omics tools are generally characterized by large data sets with many variables obtained under different environmental conditions. Clustering methods and more specifically two-mode clustering methods are excellent tools for analyzing this type of data. Two-mode clustering methods allow for analysis of the behavior of subsets of metabolites under different experimental conditions. In addition, the results are easily visualized. In this paper we introduce a two-mode clustering method based on a genetic algorithm that uses a criterion that searches for homogeneous clusters. Furthermore we introduce a cluster stability criterion to validate the clusters and we provide an extended knee plot to select the optimal number of clusters in both experimental and metabolite modes. The genetic algorithm-based two-mode clustering gave biological relevant results when it was applied to two real life metabolomics data sets. It was, for instance, able to identify a catabolic pathway for growth on several of the carbon sources