2,250 research outputs found
Internet-based self-management in asthma
This thesis describes the role of internet-based support in the delivery of an asthma self management program. First, the compliance and reliability of home lung function monitoring, one of the key features of asthma self-management, was studied and appeared to be high over a 4-week period. Second, we explored intrinsic barriers to current asthma management and revealed possible benefits from internet-based asthma self-management. Participants considered feasible electronic monitoring, easily accessible information, e-mail communication and the use of an electronic action plan to be the main benefits of internet-based asthma self-management. Third, we assessed the clinical effectiveness and cost effectiveness of an internet-based asthma self-management program over a period of 1 year. Internet-based self-management improved asthma related quality of life, asthma control, symptom-free days and lung function, but did not decrease the number of exacerbations. The benefits gained were attained at reasonable costs from a societal perspective and even more so from a health care perspective.ZonMW (Nederlandse organisatie voor gezondheidsonderzoek en zorginnovatie), Astmafonds en SBOH (werkgever van huisartsen in opleiding).UBL - phd migration 201
Draft Genome Sequence of Plantibacterflavus Strain 251 Isolated from a Plant Growing in a Chronically Hydrocarbon-Contaminated Site.
Plantibacter flavus isolate 251 is a bacterial endophyte isolated from an Achillea millefolium plant growing in a natural oil seep soil located in Oil Springs, Ontario, Canada. We present here a draft genome sequence of an infrequently reported genus Plantibacter, highlighting an endophytic lifestyle and biotechnological potential
Physiological and transcriptome changes induced by Pseudomonas putida acquisition of an integrative and conjugative element.
Integrative and conjugative elements (ICEs) comprise ubiquitous large mobile regions in prokaryotic chromosomes that transmit vertically to daughter cells and transfer horizontally to distantly related lineages. Their evolutionary success originates in maximized combined ICE-host fitness trade-offs, but how the ICE impacts on the host metabolism and physiology is poorly understood. Here we investigate global changes in the host genetic network and physiology of Pseudomonas putida with or without an integrated ICEclc, a model ICE widely distributed in proteobacterial genomes. Genome-wide gene expression differences were analyzed by RNA-seq using exponentially growing or stationary phase-restimulated cultures on 3-chlorobenzoate, an aromatic compound metabolizable thanks to specific ICEclc-located genes. We found that the presence of ICEclc imposes a variety of changes in global pathways such as cell cycle and amino acid metabolism, which were more numerous in stationary-restimulated than exponential phase cells. Unexpectedly, ICEclc stimulates cellular motility and leads to more rapid growth on 3-chlorobenzoate than cells carrying only the integrated clc genes. ICEclc also concomitantly activates the P. putida Pspu28-prophage, but this in itself did not provoke measurable fitness effects. ICEclc thus interferes in a number of cellular pathways, inducing both direct benefits as well as indirect costs in P. putida
Genome-wide gene expression changes of Pseudomonas veronii 1YdBTEX2 during bioaugmentation in polluted soils.
Bioaugmentation aims to use the capacities of specific bacterial strains inoculated into sites to enhance pollutant biodegradation. Bioaugmentation results have been mixed, which has been attributed to poor inoculant growth and survival in the field, and, consequently, moderate catalytic performance. However, our understanding of biodegradation activity mostly comes from experiments conducted under laboratory conditions, and the processes occurring during adaptation and invasion of inoculants into complex environmental microbiomes remain poorly known. The main aim of this work was thus to study the specific and different cellular reactions of an inoculant for bioaugmentation during adaptation, growth and survival in natural clean and contaminated non-sterile soils, in order to better understand factors limiting bioaugmentation.
As inoculant we focused on the monoaromatic compound-degrading bacterium Pseudomonas veronii 1YdBTEX2. The strain proliferated in all but one soil types in presence and in absence of exogenously added toluene. RNAseq and differential genome-wide gene expression analysis illustrated both a range of common soil responses such as increased nutrient scavenging and recycling, expression of defense mechanisms, as well as environment-specific reactions, notably osmoprotection and metal homeostasis. The core metabolism of P. veronii remained remarkably constant during exponential growth irrespective of the environment, with slight changes in cofactor regeneration pathways, possibly needed for balancing defense reactions.
P. veronii displayed a versatile global program, enabling it to adapt to a variety of soil environments in the presence and even in absence of its target pollutant toluene. Our results thus challenge the widely perceived dogma of poor survival and growth of exogenous inoculants in complex microbial ecosystems such as soil and provide a further basis to developing successful bioaugmentation strategies
Draft Genome Sequence of Microbacterium foliorum Strain 122 Isolated from a Plant Growing in a Chronically Hydrocarbon-Contaminated Site.
Microbacterium foliorum strain 122 is a bacterial endophyte isolated from a Dactylis glomerata plant growing in a natural oil seep soil located in Oil Springs, Ontario, Canada. We present here a draft genome sequence of an endophytic strain that has promising potential in hydrocarbon degradation and plant growth promotion
Insights into Mobile Genetic Elements of the Biocide-Degrading Bacterium Pseudomonas nitroreducens HBP-1.
The sewage sludge isolate Pseudomonas nitroreducens HBP-1 was the first bacterium known to completely degrade the fungicide 2-hydroxybiphenyl. PacBio and Illumina whole-genome sequencing revealed three circular DNA replicons: a chromosome and two plasmids. Plasmids were shown to code for putative adaptive functions such as heavy metal resistance, but with unclarified ability for self-transfer. About one-tenth of strain HBP-1's chromosomal genes are likely of recent horizontal influx, being part of genomic islands, prophages and integrative and conjugative elements (ICEs). P. nitroreducens carries two large ICEs with different functional specialization, but with homologous core structures to the well-known ICEclc of Pseudomonas knackmussii B13. The variable regions of ICEPni1 (96 kb) code for, among others, heavy metal resistances and formaldehyde detoxification, whereas those of ICEPni2 (171 kb) encodes complete meta-cleavage pathways for catabolism of 2-hydroxybiphenyl and salicylate, a protocatechuate pathway and peripheral enzymes for 4-hydroxybenzoate, ferulate, vanillin and vanillate transformation. Both ICEs transferred at frequencies of 10 <sup>-6</sup> -10 <sup>-8</sup> per P. nitroreducens HBP-1 donor into Pseudomonas putida, where they integrated site specifically into tRNA <sup>Gly</sup> -gene targets, as expected. Our study highlights the underlying determinants and mechanisms driving dissemination of adaptive properties allowing bacterial strains to cope with polluted environments
Using State-of-the-art Emotion Detection Models in a Crisis Communication Context
Times of crisis are usually associated with highly emotional experiences, which often result in emotionally charged communication. This is especially the case on social media. Identifying the emotional climate on social media is imperative in the context of crisis communication, e.g., in view of shaping crisis response strategies. However, the sheer volume of social media data often makes manual oversight impossible. In this paper, we therefore investigate how automatic methods for emotion detection can aid research on crisis communication and social media. Concretely, we investigate two Dutch emotion detection models (a transformer model and a classical machine learning model based on dictionaries) and apply them to Dutch tweets about four different crisis cases. First, we perform a validation study to assess the performance of these models in the domain of crisis-related tweets. Secondly, we propose a framework for monitoring the emotional climate on social media, and assess whether emotion detection models can be used to address the steps in the framework
Long-term effects of husbandry procedures on stress-related parameters in male mice of two strains
In socially unstable groups of male laboratory mice, individuals may experience a chronic stress situation. Previous experiments have shown that the transfer of specific olfactory cues during cage cleaning, and the provision of nesting material decrease aggression and stress in group-housed male mice. In this study, the combined effect of these husbandry procedures were tested for their long-term effect on stress in groups of moderately aggressive (BALB/c) and severely aggressive (CD-1) male mice. The physiological and behavioural stress-related parameters used were body weight, food and water intake, spleen and thymus weight, adrenal tyrosine hydroxylase activity, urine corticosterone levels and behaviour in a cage emergence test. Long-term provision of nesting material and its transfer during cage cleaning was found to influence several stress-related physiological parameters. Mice housed in cages enriched with nesting material had lower urine corticosterone levels and heavier thymuses, and they consumed less food and water than standard-housed mice. Furthermore, marked differences were found between strains. CD-1 mice were less anxious in the cage emergence test, weighed more, ate and drank more, and had heavier thymuses but lighter spleens and lower corticosterone levels than BALB/c mice. We conclude that the long-term provision of nesting material, including the transfer of nesting material during cage cleaning, reduces stress and thereby enhances the welfare of laboratory mice.</p
Reproducible Propagation of Species-Rich Soil Bacterial Communities Suggests Robust Underlying Deterministic Principles of Community Formation.
Microbiomes are typically characterized by high species diversity but it is poorly understood how such system-level complexity can be generated and propagated. Here, we used soil microcosms as a model to study development of bacterial communities as a function of their starting complexity and environmental boundary conditions. Despite inherent stochastic variation in manipulating species-rich communities, both laboratory-mixed medium complexity (21 soil bacterial isolates in equal proportions) and high-diversity natural top-soil communities followed highly reproducible succession paths, maintaining 16S rRNA gene amplicon signatures prominent for known soil communities in general. Development trajectories and compositional states were different for communities propagated in soil microcosms than in liquid suspension. Compositional states were maintained over multiple renewed growth cycles but could be diverged by short-term pollutant exposure. The different but robust trajectories demonstrated that deterministic taxa-inherent characteristics underlie reproducible development and self-organized complexity of soil microbiomes within their environmental boundary conditions. Our findings also have direct implications for potential strategies to achieve controlled restoration of desertified land. IMPORTANCE There is now a great awareness of the high diversity of most environmental ("free-living") and host-associated microbiomes, but exactly how diverse microbial communities form and maintain is still highly debated. A variety of theories have been put forward, but testing them has been problematic because most studies have been based on synthetic communities that fail to accurately mimic the natural composition (i.e., the species used are typically not found together in the same environment), the diversity (usually too low to be representative), or the environmental system itself (using designs with single carbon sources or solely mixed liquid cultures). In this study, we show how species-diverse soil bacterial communities can reproducibly be generated, propagated, and maintained, either from individual isolates (21 soil bacterial strains) or from natural microbial mixtures washed from top-soil. The high replicate consistency we achieve both in terms of species compositions and developmental trajectories demonstrates the strong inherent deterministic factors driving community formation from their species composition. Generating complex soil microbiomes may provide ways for restoration of damaged soils that are prevalent on our planet
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