Evidence for early disk-locking among low-mass members of the Orion Nebula Cluster

We present high-resolution spectroscopic observations for 91 PMS stars in ONC with masses in the range 0.10-0.25Msun carried out with the multi-fiber spectrograph FLAMES@ESO. Our aim is to better understand the disk-locking scenario in very low-mass stars. We have derived radial velocities, vsini, and full width at 10% of the Halpha emission peak. Using published measurements of infrared excess as disk tracer, and equivalent width of the NIR CaII line lambda8542, mid-IR difference [3.6]-[8.0]micron derived by Spitzer data, and 10% Halpha width as diagnostic of the level of accretion, we have looked for any correlation between vsini divided by the radius and presence of disk and accretion. Four low-mass stars are SB2 systems. The distribution of rotation periods derived from our vsini measurements is unimodal with a peak of few days. Our is lower than the one expected for a random distribution. We find no evidence for a population of fast rotators close to the break-up velocity. A clear correlation between vsini/R and Delta(Ic-K) has been found. While for stars with no circumstellar disk a spread in the rotation rates is seen, stars with a circumstellar disk show an abrupt drop in their rotation rates by a factor of ~5. On the other hand, only a partial correlation between vsini and accretion is observed when other indicators are used. The X-ray coronal activity level shows no dependence on vsini/R suggesting that all stars are in a saturated regime limit. The critical velocity is probably below our vsini detection limit of 9 km/s. The ONC low-mass stars in our sample at present seem to be not locked, but the clear correlation we find between rotation and IR color excess suggests that they were locked once. In addition, the percentage of accretors seems to scale inversely to the stellar mass.Comment: 16 pages, 2 Tables, 17 figures. Accepted by Astronomy and Astrophysics. Full version of abstract is available in the manuscrip

An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core

Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles

Loss of Function in Escherichia coli exposed to Environmentally Relevant Concentrations of Benzalkonium Chloride

Assessing the risk of resistance associated with biocide exposure commonly involves exposing microorganisms to biocides at concentrations close to the MIC. With the aim of representing exposure to environmental biocide residues, MG1655 was grown for 20 passages in the presence or absence of benzalkonium chloride (BAC) at 100 ng/L and 1000 ng/L (0.0002% and 0.002% of the MIC respectively). BAC susceptibility, planktonic growth rates, motility and biofilm-formation were assessed, and differentially expressed genes determined via RNA-sequencing. Planktonic growth rate and biofilm-formation were significantly reduced (p<0.001) following BAC adaptation, whilst BAC minimum bactericidal concentration increased two-fold. Transcriptomic analysis identified 289 upregulated and 391 downregulated genes after long-term BAC adaptation when compared to the respective control organism passaged in BAC-free-media. When the BAC-adapted bacterium was grown in biocide-free medium, 1052 genes were upregulated and 753 were down regulated. Repeated passage solely in biocide-free medium resulted in 460 upregulated and 476 downregulated genes compared to unexposed bacteria. Long-term exposure to environmentally relevant BAC concentrations increased the expression of genes associated with efflux and reduced gene expression associated with outer-membrane porins, motility and chemotaxis. This was manifested phenotypically through loss-of-function (motility). Repeated passage in a BAC-free-environment resulted in the up-regulation of multiple respiration-associated genes, which was reflected by increased growth rate. In summary, repeated exposure of to BAC residues resulted in significant alterations in global gene expression that were associated with minor decreases in biocide susceptibility, reductions in growth-rate and biofilm-formation, and loss of motility. Exposure to very low concentrations of biocide in the environment is a poorly understood risk factor for antimicrobial resistance. Repeated exposure to trace levels of the biocide BAC resulted in loss of function (motility) and a general reduction in bacterial fitness, but relatively minor decreases in susceptibility. These changes were accompanied by widespread changes in the transcriptome. This demonstrates the importance of including phenotypic characterisation in studies designed to assess the risks of biocide exposure. [Abstract copyright: Copyright © 2018 American Society for Microbiology.

Clinician-rated mental health in outpatient child and adolescent mental health services: associations with parent, teacher and adolescent ratings

<p>Abstract</p> <p>Background</p> <p>Clinician-rated measures are used extensively in child and adolescent mental health services (CAMHS). The Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA) is a short clinician-rated measure developed for ordinary clinical practice, with increasing use internationally. Several studies have investigated its psychometric properties, but there are few data on its correspondence with other methods, rated by other informants. We compared the HoNOSCA with the well-established Achenbach System of Empirically Based Assessment (ASEBA) questionnaires: the Child Behavior Checklist (CBCL), the Teacher's Report Form (TRF), and the Youth Self-Report (YSR).</p> <p>Methods</p> <p>Data on 153 patients aged 6-17 years at seven outpatient CAMHS clinics in Norway were analysed. Clinicians completed the HoNOSCA, whereas parents, teachers, and adolescents filled in the ASEBA forms. HoNOSCA <it>total score </it>and nine of its scales were compared with similar ASEBA scales. With a multiple regression model, we investigated how the ASEBA ratings predicted the clinician-rated HoNOSCA and whether the different informants' scores made any unique contribution to the prediction of the HoNOSCA scales.</p> <p>Results</p> <p>We found moderate correlations between the total problems rated by the clinicians (HoNOSCA) and by the other informants (ASEBA) and good correspondence between eight of the nine HoNOSCA scales and the similar ASEBA scales. The exception was HoNOSCA scale 8 <it>psychosomatic symptoms </it>compared with the ASEBA s<it>omatic problems </it>scale. In the regression analyses, the CBCL and TRF <it>total problems </it>scores together explained 27% of the variance in the HoNOSCA <it>total scores </it>(23% for the age group 11-17 years, also including the YSR). The CBCL provided unique information for the prediction of the HoNOSCA <it>total score</it>, HoNOSCA scale 1 <it>aggressive behaviour</it>, HoNOSCA scale 2 <it>overactivity or attention problems</it>, HoNOSCA scale 9 <it>emotional symptoms</it>, and HoNOSCA scale 10 <it>peer problems; </it>the TRF for all these except HoNOSCA scale 9 <it>emotional symptoms; </it>and the YSR for HoNOSCA scale 9 <it>emotional symptoms </it>only.</p> <p>Conclusion</p> <p>This study supports the concurrent validity of the HoNOSCA. It also demonstrates that parents, teachers and adolescents all contribute unique information in relation to the clinician-rated HoNOSCA, indicating that the HoNOSCA ratings reflect unique perspectives from multiple informants.</p

Differences between patients' and clinicians' report of sleep disturbance: a field study in mental health care in Norway

<p>Abstract</p> <p>Background</p> <p>The aims of the study was to assess the prevalence of diagnosed insomnia and the agreement between patient- and clinician-reported sleep disturbance and use of prescribed hypnotic medication in patients in treatment for mental disorders.</p> <p>Methods</p> <p>We used three cross-sectional, multicenter data-sets from 2002, 2005, and 2008. Data-set 1 included diagnostic codes from 93% of all patients receiving treatment in mental health care in Norway (<it>N </it>= 40261). Data-sets 2 (<it>N </it>= 1065) and 3 (<it>N </it>= 1181) included diagnostic codes, patient- and clinician-reported sleep disturbance, and use of prescribed hypnotic medication from patients in 8 mental health care centers covering 10% of the Norwegian population.</p> <p>Results</p> <p>34 patients in data-set 1 and none in data-sets 2 and 3 had a diagnosis of insomnia as a primary or comorbid diagnosis. In data-sets 2 and 3, 42% and 40% of the patients reported sleep disturbance, whereas 24% and 13% had clinician-reported sleep disturbance, and 7% and 9% used hypnotics. Patients and clinicians agreed in 29% and 15% of the cases where the patient or the clinician or both had reported sleep disturbance. Positive predictive value (PPV) of clinicians' evaluations of patient sleep disturbance was 62% and 53%. When the patient reported sleep disturbance as one of their most prominent problems PPV was 36% and 37%. Of the patients who received hypnotic medication, 23% and 29% had neither patient nor clinician-rated sleep disturbance.</p> <p>Conclusion</p> <p>When patients meet the criteria for a mental disorder, insomnia is almost never diagnosed, and sleep disturbance is imprecisely recognized relative to the patients' experience of sleep disturbance.</p

GeneTools – application for functional annotation and statistical hypothesis testing

BACKGROUND: Modern biology has shifted from "one gene" approaches to methods for genomic-scale analysis like microarray technology, which allow simultaneous measurement of thousands of genes. This has created a need for tools facilitating interpretation of biological data in "batch" mode. However, such tools often leave the investigator with large volumes of apparently unorganized information. To meet this interpretation challenge, gene-set, or cluster testing has become a popular analytical tool. Many gene-set testing methods and software packages are now available, most of which use a variety of statistical tests to assess the genes in a set for biological information. However, the field is still evolving, and there is a great need for "integrated" solutions. RESULTS: GeneTools is a web-service providing access to a database that brings together information from a broad range of resources. The annotation data are updated weekly, guaranteeing that users get data most recently available. Data submitted by the user are stored in the database, where it can easily be updated, shared between users and exported in various formats. GeneTools provides three different tools: i) NMC Annotation Tool, which offers annotations from several databases like UniGene, Entrez Gene, SwissProt and GeneOntology, in both single- and batch search mode. ii) GO Annotator Tool, where users can add new gene ontology (GO) annotations to genes of interest. These user defined GO annotations can be used in further analysis or exported for public distribution. iii) eGOn, a tool for visualization and statistical hypothesis testing of GO category representation. As the first GO tool, eGOn supports hypothesis testing for three different situations (master-target situation, mutually exclusive target-target situation and intersecting target-target situation). An important additional function is an evidence-code filter that allows users, to select the GO annotations for the analysis. CONCLUSION: GeneTools is the first "all in one" annotation tool, providing users with a rapid extraction of highly relevant gene annotation data for e.g. thousands of genes or clones at once. It allows a user to define and archive new GO annotations and it supports hypothesis testing related to GO category representations. GeneTools is freely available through www.genetools.n

Consumer practices and prevalence of Campylobacter, Salmonella and norovirus in kitchens from six European countries

About 40% of foodborne infections are acquired in the home. The aim of the present study was to track contamination of pathogens during domestic food preparation and link the contamination to preparation practices. Research participants from 87 households in six European countries were observed and interviewed during shopping and preparation of a chicken and vegetable meal. The presence of Salmonella spp., Campylobacter spp. and norovirus on raw chicken, kitchen surfaces, cloths and sponges was determined. The prevalence of Campylobacter on raw chicken varied from 8.3% in Norway (NO) to 80% in France (FR) and Portugal (PT), with a mean prevalence of 57%. Campylobacter was found on half of the products that had been frozen and appeared to be less prevalent on chicken from supermarkets than other sources. Salmonella was found in 8.6% of raw chicken samples, exclusively from Hungary (HU). A relationship between observed practices and spread of pathogens to kitchen surfaces was found only for the use of cutting boards for chicken and/or vegetables. After food preparation, Campylobacter and Salmonella were isolated from 23% (samples derived from HU, RO, UK) and 8.7% (HU), respectively of cutting boards. Research participants in France and Portugal were more likely to buy products that fitted their recipe, with less need for using cutting boards. Using the same board and knife for vegetables after using it for chicken and without washing with detergent was common in Portugal and Romania, but not in the other countries. Contamination with Campylobacter to other kitchen surfaces or washing utensils were found in five households (UK, RO, PT). Rinsing chicken in sinks was common in three countries (PT, HU, RO), and washing vegetables in the same sink was also usual. Prevalence of Norovirus was low, with detection in one out of 451 samples. The participants' awareness of the risk posed by pathogens from raw chicken differed among the six countries, with higher awareness in Norway and the UK than the other countries studied. In conclusion, practices intended to avoid cross-contamination from chicken to kitchen surfaces and washing utensils are not established among consumers in all European countries. Nevertheless, cross-contamination events that disseminate infectious doses of pathogens seems to be rare, probably due to the relatively low levels of pathogens in food combined with food preferences. Food safety interventions must consider the national food culture, preferences, practices and the prevalence and levels of pathogens in food. Emphasis should be on providing and promoting chicken products with lower risk (prevalence of pathogens, ready-to-cook) and safe use of cutting boards

Antibacterial activity and mode of action of selected glucosinolate hydrolysis products against bacterial pathogens

Plants contain numerous components that are important sources of new bioactive molecules with antimicrobial properties. Isothiocyanates (ITCs) are plant secondary metabolites found in cruciferous vegetables that are arising as promising antimicrobial agents in food industry. The aim of this study was to assess the antibacterial activity of two isothiocyanates (ITCs), allylisothiocyanate (AITC) and 2-phenylethylisothiocyanate (PEITC) against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. The antibacterial mode of action was also characterized by the assessment of different physiological indices: membrane integrity, intracellular potassium release, physicochemical surface properties and surface charge. The minimum inhibitory concentration (MIC) of AITC and PEITC was 100 g/mL for all bacteria. The minimum bactericidal concentration (MBC) of the ITCs was at least 10 times higher than the MIC. Both AITC and PEITC changed the membrane properties of the bacteria decreasing their surface charge and compromising the integrity of the cytoplasmatic membrane with consequent potassium leakage and propidium iodide uptake. The surface hydrophobicity was also non-specifically altered (E. coli and L. monocytogenes become less hydrophilic; P. aeruginosa and S. aureus become more hydrophilic). This study shows that AITC and PEITC have strong antimicrobial potential against the bacteria tested, through the disruption of the bacterial cell membranes. Moreover, phytochemicals are highlighted as a valuable sustainable source of new bioactive products.This work was supported by the Operational Programme for Competitiveness Factors - COMPETE and by the Portuguese Foundation for Science and Technology through Project Phytodisinfectants - PTDC/DTP-SAP/1078/2012 (COMPETE: FCOMP-01-0124-FEDER-028765), the PhD grant awarded to Ana Abreu (SFRH/BD/84393/2012), and the post-doctoral grants awarded to Anabela Borges (SFRH/BPD/98684/2013) and Lucia C. Simoes (SFRH/BPD/81982/2011). Also, this work was undertaken as part of the European Research Project SUSCLEAN (Contract no FP7-KBBE-2011-5, project number: 287514) and the COST Action FA1202. The authors are solely responsible for this work. It does not represent the opinion of the European Community, and the Community is not responsible for any use that might be made of data appearing herein