29 research outputs found

    Marsh macrophyte responses to inundation anticipate impacts of sea-level rise and indicate ongoing drowning of North Carolina marshes

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    In situ persistence of coastal marsh habitat as sea level rises depends on whether macrophytes induce compensatory accretion of the marsh surface. Experimental planters in two North Carolina marshes served to expose two dominant macrophyte species to six different elevations spanning 0.75 m (inundation durations 0.4ñ€“99 %). Spartina alterniflora and Juncus roemerianus exhibited similar responsesñ€”with production in planters suggesting initial increases and then demonstrating subsequent steep declines with increasing inundation, conforming to a segment of the ecophysiological parabola. Projecting inundation levels experienced by macrophytes in the planters onto adjacent marsh platforms revealed that neither species occupied elevations associated with increasing production. Declining macrophyte production with rising seas reduces both bioaccumulation of roots below-ground and baffle-induced sedimentation above-ground. By occupying only descending portions of the parabola, macrophytes in central North Carolina marshes are responding to rising water levels by progressive declines in production, ultimately leading to marsh drowning

    Exome sequencing identifies frequent mutation of ARID1A in molecular subtypes of gastric cancer

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    LettersGastric cancer is a heterogeneous disease with multiple environmental etiologies and alternative pathways of carcinogenesis. Beyond mutations in TP53, alterations in other genes or pathways account for only small subsets of the disease. We performed exome sequencing of 22 gastric cancer samples and identified previously unreported mutated genes and pathway alterations; in particular, we found genes involved in chromatin modification to be commonly mutated. A downstream validation study confirmed frequent inactivating mutations or protein deficiency of ARID1A, which encodes a member of the SWI-SNF chromatin remodeling family, in 83% of gastric cancers with microsatellite instability (MSI), 73% of those with Epstein-Barr virus (EBV) infection and 11% of those that were not infected with EBV and microsatellite stable (MSS). The mutation spectrum for ARID1A differs between molecular subtypes of gastric cancer, and mutation prevalence is negatively associated with mutations in TP53. Clinically, ARID1A alterations were associated with better prognosis in a stage-independent manner. These results reveal the genomic landscape, and highlight the importance of chromatin remodeling, in the molecular taxonomy of gastric cancer. © 2011 Nature America, Inc. All rights reserved.link_to_subscribed_fulltex

    The development and validation of a health-related quality of life questionnaire for pre-school children with a chronic heart disease

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    PURPOSE: Heart diseases are often associated with residual injuries, persisting functional restrictions, and long-term sequelae for psychosocial development. Currently, there are no disease-specific instruments to assess the health-related quality of life (HrQoL) of pre-school children. The aims of this study were to develop a parent proxy instrument to measure the HrQoL of children aged 3-7 years with a heart disease and to confirm its validity and reliability. METHODS: Items from the Preschool Pediatric Cardiac Quality of Life Inventory (P-PCQLI) were generated through focus groups of caregivers. In a pilot study, comprehensibility and feasibility were tested. Five subdimensions were defined theoretically. Psychometric properties were analysed within a multicentre study with 167 parental caregivers. RESULTS: The final 52-item instrument contains a total score covering five moderately inter-correlated dimensions. The total score of the questionnaire showed a very high internal consistency (Cronbachs' α = 0.95). Test-retest correlation was at r tt = 0.96. External validity was indicated by higher correlations (r = 0.24-0.68) with a generic paediatric quality of life questionnaire (KINDL) compared to the Strengths and Difficulties Questionnaire (r = 0.17 to 0.59). Low P-PCQLI total scores were significantly associated with inpatient as opposed to outpatient treatment (t = 6.04, p < .001), with at least moderate disease severity ((t = 5.05, p < .001) NYHA classification) and with poorer prognosis (t = 5.53, p < .001) as estimated by the physician. CONCLUSIONS: The P-PCQLI is reliable and valid for pre-school children with a heart disease. It could be used as a screening instrument in routine care, and for evaluation of HrQoL outcomes in clinical trials and intervention research
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