Plasmid-mediated dissemination of antibiotic resistance among fecal Enterobacteriaceae in natural ecosystems may contribute to the persistence of antibiotic resistance genes in anthropogenically impacted environments. Plasmid transfer frequencies measured under laboratory conditions might lead to overestimation of plasmid transfer potential in natural ecosystems. This study assessed differences in the conjugative transfer of an IncP-1 (pKJK5) plasmid to three natural Escherichia coli strains carrying extended-spectrum beta-lactamases, by filter mating. Matings were performed under optimal laboratory conditions (rich LB medium and 37°C) and environmentally relevant temperatures (25, 15 and 9°C) or nutrient regimes mimicking environmental conditions and limitations (synthetic wastewater and soil extract). Under optimal nutrient conditions and temperature, two recipients yielded high transfer frequencies (5 × 10–1) while the conjugation frequency of the third strain was 1000-fold lower. Decreasing mating temperatures to psychrophilic ranges led to lower transfer frequencies, albeit all three strains conjugated under all the tested temperatures. Low nutritive media caused significant decreases in transconjugants (−3 logs for synthetic wastewater; −6 logs for soil extract), where only one of the strains was able to produce detectable transconjugants. Collectively, this study highlights that despite less-than-optimal conditions, fecal organisms may transfer plasmids in the environment, but the transfer of pKJK5 between microorganisms is limited mainly by low nutrient conditions.
MULTIFILE
This research focuses on exit choices within SMEs. In this study, “exit choice” refers to the decision to opt for either liquidation or sale of the firm. The predictions focus on human-capital and firm-resource variables. The hypotheses are tested on a set of 158 owners of small firms, the majority of which are micro-firms with 0–9 employees. The results of a series of binominal logistic regression analyses show that firm-resource characteristics (previous sales turnover, the firm’s independence from its owner, and firm size), together with one aspect of the owner’s specific human capital (the owner’s acquisition experience), predict exit choice. The conclusions have been made with caution, as the dataset is relatively small and the number of predictors is limited.
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The aim of this study is to examine the relationship between successor characteristics, transfer planning characteristics and post-transfer profitability within Dutch SMEs. On the one hand, based on the resource dependency view, it is assumed that successors with more knowledge and experience, derived from work experience from outside the target firm, will be able to extract higher rents from the firm than those with less (diverse) work experience. On the other hand, based on the knowledge management literature, and in particular, concepts such as tacit knowledge, this research makes the contrasting prediction that posttransfer profitability is likely to be higher in firms where the successor is an insider and is related to the predecessor. Moreover, this paper proposes, based on the theory of planned behaviour, that written plan and strategic intent have a positive association with post-transfer profitability. The study is based on quantitative analysis of a random sample of Dutch SMEs. Initial results from the current study suggest that determinants of post-transfer profitability may be quite different in the family-to-family ownership vs. nonfamily ownership transfer conditions (i.e. whether or not the successor is related to the predecessor). Significant interaction effect is found such that the effect of strategic planning, in particular, varies depending on the nature of the transfer relationship (family to family, vs family to nonfamily). Other results offer mixed support for the proposed theories.
MKB-bedrijven op het gebied van architectuur, gebiedsontwikkeling, ontwerp, digital design en technologie-ontwikkeling zien een nieuwe ‘markt’ ontstaan in de toenemende interesse voor de stedelijke commons. Dat zijn lokale gemeenschappen waarin mensen resources zoals energie, mobiliteit of woonruimte met elkaar delen en beheren, op een duurzame en pro-sociale manier. MKB-bedrijven zien kansen om in co-creatie met deze leefgemeenschappen nieuwe diensten en producten te ontwikkelen waarmee bewoners hun hulpbronnen gemeenschappelijk kunnen managen. MKB-bedrijven zien de ontwikkeling van stedelijke commons daarnaast als mogelijke oplossing voor urgente maatschappelijke vraagstukken en missies op het gebied van inclusieve woningbouw, duurzaamheid en de energietransitie. Voor het goed functioneren van de commons is een heldere articulatie en implementatie van hun onderliggende (maatschappelijke) waarden essentieel. Dit vraagt van MKB-bedrijven een zoektocht naar nieuwe manieren van gebieds- en technologie-ontwikkeling in samenwerking met bewoners. Een specifiek probleem daarbij betreft het vertalen van de commons-waarden naar een technologisch systeem dat het gezamenlijk beheer van hulpbronnen mogelijk maakt. Hiervoor wordt veel verwacht van digitale platformen en distributed ledgers technologies zoals de blockchain. Dit zijn databases die precies bijhouden wie wat bijdraagt en gebruikt. Ze koppelen zo’n boekhouding ook aan rechten, plichten en reputaties van de deelnemers. Bij de inrichting van zo’n systeem moeten ontwerpers steeds keuzes maken en rekening houden met spanningen tussen bijvoorbeeld privacy en transparantie, of individuele en collectieve belangen. In dit ontwerpproces stuiten MKBs op een kennishiaat. Hoe kunnen de onderliggende (maatschappelijke) waarden van commons-gemeenschappen 1) worden gearticuleerd en 2) vertaald naar een ontwerp voor de organisatie van een stedelijke commons met behulp van digitale platformen? Dit onderzoek verkent deze vragen in een fieldlab in Amersfoort, op twee ‘transfersites’ in Amsterdam en Birmingham, en met community of practice partners. Samen met hen worden een set design-principes en richtlijnen ontwikkeld voor het ontwerp van DLTs voor de stedelijke commons.
This research is a collaborative project between Water Future, Looop, and MNEXT to address the valorisation of a residual stream that remain after valorisation of whey towards food and feed applications: whey permeate. This permeate is a high-volume but low-quality stream, which is currently used as a filler for mainly animal feed, but with the large amounts produced in NW-Europe it is essential to valorise whey permeate higher in the value chain, for example into a biobased resource which replace fossil-based resources in the chemical industry. To accomplish this, pre-processing steps are necessary to remove minerals. Electrodialysis (ED) can remove unwanted minerals from whey permeate by applying an electric field across its membranes. Using ED, whey permeate is expected to demineralize into a liquid which is suitable for application as biobased resource for various applications. Moreover, the extracted mineral stream can also be reused. This one-year project aims to quantify and optimize the demineralisation of whey permeates using a lab-scale ED setup to make the whey permeate stream suitable for re-use and thus reduce the environmental impact of this stream. The project involves setting up an ED setup provided by Water Future to treat whey permeates supplied by Looop, assessing the suitability of treated permeate as a biobased resource in the chemical industry and processing the produced mineral streams into new biobased resources. The result of this research will demonstrate the use of ED as a valorisation technique for whey permeates and the integration of multiple processes into a valorisation pathway to transform costly whey permeates into value-added products. MNEXT leads the research development, aiming to potentially establish a recycle strategy for resource recovery in the dairy industry. The results will be presented through educational activities, reports, digital platforms, and conferences to transfer knowledge to a broader audience.
