12 research outputs found
Polydimethylsiloxane (silicone rubber) brooch as a personal passive air sampler for semi-volatile organic compounds
Exposure assessments conducted using a personal sampler include the contribution of human activities to exposure that is neglected when using a stationary air sampler. This study evaluated the uptake characteristics and application of the polydimethylsiloxane (PDMS or silicone rubber) brooch as a personal passive air sampler (PPAS) for measuring concentrations of two groups of semi-volatile organic compounds (SVOCs), namely phthalates and organophosphate esters (OPEs), indoors in proximity to the breathing zone.
Uptake rates of the PDMS brooch were calibrated against a personal low volume active air sampler (PLV-AAS) co-deployed on each of five study participants working in offices for 8âŻhs daily for four days. Sampling rates measured here ranged from 0.41âŻÂ±âŻ0.33 to 1.33âŻÂ±âŻ0.34âŻm3 dayâ1âŻdmâ2 with an average value of 0.86âŻÂ±âŻ0.29âŻm3 dayâ1âŻdmâ2.
Personal air concentrations of 1211 to 2640âŻngâŻmâ3 for â5 phthalates and 254 to 663âŻngâŻmâ3 for â5 OPEs were measured for three study participants who used the PDMS brooches continuously for seven days. These concentrations resulted in estimated inhalation exposures of 19,400 to 42,400âŻng dayâ1 for â5 phthalates and 4,070 to 10,600âŻng dayâ1 for â5 OPEs.
This study demonstrated that the PDMS brooch can be used to assess inhalation exposure when worn for at least 24âŻh indoors, for compounds present in >4âŻngâŻmâ3 in air such as individual phthalates and OPEs tested here.Research funding was provided by Environment and Climate Change Canada (GCXE17S017), the Allergy, Genes and Environment Network (Aller Gen NCE, No. 12ASI3), Health Canada (Agreement No. 4500308341), the Natural Sciences and Engineering Research Council of Canada (NSERC, No. RGPAS 429679-12). Maria Lorenzo research visit to University of Toronto was supported by the Foundation Tatiana PĂ©rez de GuzmĂĄn el Bueno (Predoctoral Grant 2014). We thank Yuchao Wan of Diamond Environmental Lab, University of Toronto for helping with instrument maintenance, the volunteers who wore the personal samplers and Dalla Lana School of Public Health, University of Toronto for lending us the active sampler pumps.Peer reviewe
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Right Prefrontal Cortical Thickness Is Associated With Response to Cognitive-Behavioral Therapy in Children With Obsessive-Compulsive Disorder.
OBJECTIVE: Cognitive-behavioral therapy (CBT) is considered a first-line treatment for obsessive-compulsive disorder (OCD) in pediatric and adult populations. Nevertheless, some patients show partial or null response. The identification of predictors of CBT response may improve clinical management of patients with OCD. Here, we aimed to identify structural magnetic resonance imaging (MRI) predictors of CBT response in 2 large series of children and adults with OCD from the worldwide ENIGMA-OCD consortium. METHOD: Data from 16 datasets from 13 international sites were included in the study. We assessed which variations in baseline cortical thickness, cortical surface area, and subcortical volume predicted response to CBT (percentage of baseline to post-treatment symptom reduction) in 2 samples totaling 168 children and adolescents (age range 5-17.5 years) and 318 adult patients (age range 18-63 years) with OCD. Mixed linear models with random intercept were used to account for potential cross-site differences in imaging values. RESULTS: Significant results were observed exclusively in the pediatric sample. Right prefrontal cortex thickness was positively associated with the percentage of CBT response. In a post hoc analysis, we observed that the specific changes accounting for this relationship were a higher thickness of the frontal pole and the rostral middle frontal gyrus. We observed no significant effects of age, sex, or medication on our findings. CONCLUSION: Higher cortical thickness in specific right prefrontal cortex regions may be important for CBT response in children with OCD. Our findings suggest that the right prefrontal cortex plays a relevant role in the mechanisms of action of CBT in children
Epigenomic Diversity in a Global Collection of Arabidopsis thaliana Accessions
The epigenome orchestrates genome accessibility, functionality, and three-dimensional structure. Because epigenetic variation can impact transcription and thus phenotypes, it may contribute to adaptation. Here, we report 1,107 high-quality single-base resolution methylomes and 1,203 transcriptomes from the 1001 Genomes collection of Arabidopsis thaliana. Although the genetic basis of methylation variation is highly complex, geographic origin is a major predictor of genome-wide DNA methylation levels and of altered gene expression caused by epialleles. Comparison to cistrome and epicistrome datasets identifies associations between transcription factor binding sites, methylation, nucleotide variation, and co-expression modules. Physical maps for nine of the most diverse genomes reveal how transposons and other structural variants shape the epigenome, with dramatic effects on immunity genes. The 1001 Epigenomes Project provides a comprehensive resource for understanding how variation in DNA methylation contributes to molecular and non-molecular phenotypes in natural populations of the most studied model plant
Epigenomic Diversity in a Global Collection of Arabidopsis thaliana Accessions
The epigenome orchestrates genome accessibility, functionality, and three-dimensional structure. Because epigenetic variation can impact transcription and thus phenotypes, it may contribute to adaptation. Here, we report 1,107 high-quality single-base resolution methylomes and 1,203 transcriptomes from the 1001 Genomes collection of Arabidopsis thaliana. Although the genetic basis of methylation variation is highly complex, geographic origin is a major predictor of genome-wide DNA methylation levels and of altered gene expression caused by epialleles. Comparison to cistrome and epicistrome datasets identifies associations between transcription factor binding sites, methylation, nucleotide variation, and co-expression modules. Physical maps for nine of the most diverse genomes reveal how transposons and other structural variants shape the epigenome, with dramatic effects on immunity genes. The 1001 Epigenomes Project provides a comprehensive resource for understanding how variation in DNA methylation contributes to molecular and non-molecular phenotypes in natural populations of the most studied model plant