109 research outputs found

    The Biogeochemistry of Hydrogen Sulfide: Phytoplankton Production in the Surface Ocean

    Get PDF
    Hydrogen sulfide can exist in oxic waters in the form of a dissolved gas, dissociated ions, dissolved metal sulfide complexes, and particulate metal sulfides. The sum of the dissolved species is termed total dissolved sulfide (TDS). In addition to the hydrolysis of carbonyl sulfide, it has been speculated that phytoplankton may produce TDS. We present results from preliminary culture studies which demonstrate that phytoplankton produce TDS and particulate acid-volatile sulfide (pAVS). The phylogenetic order of TDS + pAVS production (per unit cell volume) for the oceanic species examined is Synechococcus sp. \u3e Emiliania huxleyi ≈ Pyramimonas obovata \u3e Thalassiosira oceanica. Moreover, TDS and pAVS production increases when the concentrations of uncomplexed trace metals in culture media are also increased, suggesting metal detoxification via the formation of metal sulfide complexes

    In-Home Training for Fathers of Children with Autism: A Follow up Study and Evaluation of Four Individual Training Components

    Get PDF
    Literature regarding fathers of children with autism remains sparse, and because mothers are the more common intervening parent, few training methods have focused on fathers. Thus, we sought to evaluate effects of in-home training directed at fathers and their ability to train mothers in the same manner in which they were trained. Fathers were taught four skills commonly associated with in-home training interventions for parents of children with autism: following the child’s lead, imitation with animation, commenting on the child, and expectant waiting. Father skills were evaluated twice a week for 12 weeks during videotaped in-home father–child play sessions. Analyses included visual inspection of graphed data and statistical analyses of father skill acquisition, mother skill acquisition, and child behaviors with both parents. A multivariate repeated measures analysis of 18 dyads revealed significant increases in frequencies of fathers’ imitation with animation, expectant waiting, and commenting on the child. Child initiating rates increased significantly as did frequencies of child non-speech vocalizations. Analysis of mothers revealed significant increases in frequencies of imitation with animation, expectant waiting, and following the child’s lead. Child behaviors had similar results for father and mother sessions. Findings are consistent with those from our first study indicating that fathers can effectively implement skills that promote father–child social interactions and that children respond positively to this approach

    The impact of dengue illness on social distancing and caregiving behavior

    Get PDF
    Background Human mobility among residential locations can drive dengue virus (DENV) transmission dynamics. Recently, it was shown that individuals with symptomatic DENV infection exhibit significant changes in their mobility patterns, spending more time at home during illness. This change in mobility is predicted to increase the risk of acquiring infection for those living with or visiting the ill individual. It has yet to be considered, however, whether social contacts are also changing their mobility, either by socially distancing themselves from the infectious individual or increasing contact to help care for them. Social, or physical, distancing and caregiving could have diverse yet important impacts on DENV transmission dynamics; therefore, it is necessary to better understand the nature and frequency of these behaviors including their effect on mobility. Methodology and principal findings Through community-based febrile illness surveillance and RT-PCR infection confirmation, 67 DENV positive (DENV+) residents were identified in the city of Iquitos, Peru. Using retrospective interviews, data were collected on visitors and home-based care received during the illness. While 15% of participants lost visitors during their illness, 22% gained visitors; overall, 32% of all individuals (particularly females) received visitors while symptomatic. Caregiving was common (90%), particularly caring by housemates (91%) and caring for children (98%). Twenty-eight percent of caregivers changed their behavior enough to have their work (and, likely, mobility patterns) affected. This was significantly more likely when caring for individuals with low “health-related quality of well-being” during illness (Fisher’s Exact, p = 0.01). Conclusions/Significance Our study demonstrates that social contacts of individuals with dengue modify their patterns of visitation and caregiving. The observed mobility changes could impact a susceptible individual’s exposure to virus or a presymptomatic/clinically inapparent individual’s contribution to onward transmission. Accounting for changes in social contact mobility is imperative in order to get a more accurate understanding of DENV transmission

    A Genetic Risk Score Combining Ten Psoriasis Risk Loci Improves Disease Prediction

    Get PDF
    Psoriasis is a chronic, immune-mediated skin disease affecting 2–3% of Caucasians. Recent genetic association studies have identified multiple psoriasis risk loci; however, most of these loci contribute only modestly to disease risk. In this study, we investigated whether a genetic risk score (GRS) combining multiple loci could improve psoriasis prediction. Two approaches were used: a simple risk alleles count (cGRS) and a weighted (wGRS) approach. Ten psoriasis risk SNPs were genotyped in 2815 case-control samples and 858 family samples. We found that the total number of risk alleles in the cases was significantly higher than in controls, mean 13.16 (SD 1.7) versus 12.09 (SD 1.8), p = 4.577×10−40. The wGRS captured considerably more risk than any SNP considered alone, with a psoriasis OR for high-low wGRS quartiles of 10.55 (95% CI 7.63–14.57), p = 2.010×10−65. To compare the discriminatory ability of the GRS models, receiver operating characteristic curves were used to calculate the area under the curve (AUC). The AUC for wGRS was significantly greater than for cGRS (72.0% versus 66.5%, p = 2.13×10−8). Additionally, the AUC for HLA-C alone (rs10484554) was equivalent to the AUC for all nine other risk loci combined (66.2% versus 63.8%, p = 0.18), highlighting the dominance of HLA-C as a risk locus. Logistic regression revealed that the wGRS was significantly associated with two subphenotypes of psoriasis, age of onset (p = 4.91×10−6) and family history (p = 0.020). Using a liability threshold model, we estimated that the 10 risk loci account for only11.6% of the genetic variance in psoriasis. In summary, we found that a GRS combining 10 psoriasis risk loci captured significantly more risk than any individual SNP and was associated with early onset of disease and a positive family history. Notably, only a small fraction of psoriasis heritability is captured by the common risk variants identified to date

    Graduates of different UK medical schools show substantial differences in performance on MRCP(UK) Part 1, Part 2 and PACES examinations

    Get PDF
    Background: The UK General Medical Council has emphasized the lack of evidence on whether graduates from different UK medical schools perform differently in their clinical careers. Here we assess the performance of UK graduates who have taken MRCP( UK) Part 1 and Part 2, which are multiple-choice assessments, and PACES, an assessment using real and simulated patients of clinical examination skills and communication skills, and we explore the reasons for the differences between medical schools. Method: We perform a retrospective analysis of the performance of 5827 doctors graduating in UK medical schools taking the Part 1, Part 2 or PACES for the first time between 2003/2 and 2005/3, and 22453 candidates taking Part 1 from 1989/1 to 2005/3. Results: Graduates of UK medical schools performed differently in the MRCP( UK) examination between 2003/2 and 2005/3. Part 1 and 2 performance of Oxford, Cambridge and Newcastle-upon-Tyne graduates was significantly better than average, and the performance of Liverpool, Dundee, Belfast and Aberdeen graduates was significantly worse than average. In the PACES ( clinical) examination, Oxford graduates performed significantly above average, and Dundee, Liverpool and London graduates significantly below average. About 60% of medical school variance was explained by differences in pre-admission qualifications, although the remaining variance was still significant, with graduates from Leicester, Oxford, Birmingham, Newcastle-upon-Tyne and London overperforming at Part 1, and graduates from Southampton, Dundee, Aberdeen, Liverpool and Belfast underperforming relative to pre-admission qualifications. The ranking of schools at Part 1 in 2003/2 to 2005/3 correlated 0.723, 0.654, 0.618 and 0.493 with performance in 1999-2001, 1996-1998, 1993-1995 and 1989-1992, respectively. Conclusion: Candidates from different UK medical schools perform differently in all three parts of the MRCP( UK) examination, with the ordering consistent across the parts of the exam and with the differences in Part 1 performance being consistent from 1989 to 2005. Although pre-admission qualifications explained some of the medical school variance, the remaining differences do not seem to result from career preference or other selection biases, and are presumed to result from unmeasured differences in ability at entry to the medical school or to differences between medical schools in teaching focus, content and approaches. Exploration of causal mechanisms would be enhanced by results from a national medical qualifying examination

    Association of a de novo 16q copy number variant with a phenotype that overlaps with Lenz microphthalmia and Townes-Brocks syndromes

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Anophthalmia and microphthalmia are etiologically and clinically heterogeneous. Lenz microphthalmia is a syndromic form that is typically inherited in an X-linked pattern, though the causative gene mutation is unknown. Townes-Brocks syndrome manifests thumb anomalies, imperforate anus, and ear anomalies. We present a 13-year-old boy with a syndromic microphthalmia phenotype and a clinical diagnosis of Lenz microphthalmia syndrome.</p> <p>Case Presentation</p> <p>The patient was subjected to clinical and molecular evaluation, including array CGH analysis. The clinical features included left clinical anophthalmia, right microphthalmia, anteriorly placed anus with fistula, chordee, ventriculoseptal defect, patent ductus arteriosus, posteriorly rotated ears, hypotonia, growth retardation with delayed bone age, and mental retardation. The patient was found to have an approximately 5.6 Mb deletion of 16q11.2q12.1 by microarray based-comparative genomic hybridization, which includes the <it>SALL1 </it>gene, which causes Townes-Brocks syndrome.</p> <p>Conclusions</p> <p>Deletions of 16q11.2q12.2 have been reported in several individuals, although those prior reports did not note microphthalmia or anophthalmia. This region includes <it>SALL1</it>, which causes Townes-Brocks syndrome. In retrospect, this child has a number of features that can be explained by the <it>SALL1 </it>deletion, although it is not clear if the microphthalmia is a rare feature of Townes-Brocks syndrome or caused by other mechanisms. These data suggest that rare copy number changes may be a cause of syndromic microphthalmia allowing a personalized genomic medicine approach to the care of patients with these aberrations.</p

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

    Get PDF
    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

    Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

    Get PDF
    Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

    Get PDF
    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images

    Get PDF
    Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL maps are derived through computational staining using a convolutional neural network trained to classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and correlation with overall survival. TIL map structural patterns were grouped using standard histopathological parameters. These patterns are enriched in particular T cell subpopulations derived from molecular measures. TIL densities and spatial structure were differentially enriched among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for the TCGA image archives with insights into the tumor-immune microenvironment
    corecore