In this task, you are given an abstract of article. Your task is to generate label "True" if abstract is structured, otherwise generate "False". A structured abstract is composed of a topic sentence (or key sentence), relevant supporting sentences, and a closing (or transition) sentence. This structure is key to keeping your abstract focused on the main idea and creating a clear and concise image.

Input: Consider Input: Age-related changes in the niche have long been postulated to impair the function of somatic stem cells. Here we demonstrate that the aged stem cell niche in skeletal muscle contains substantially reduced levels of fibronectin (FN), leading to detrimental consequences for the function and maintenance of muscle stem cells (MuSCs). Deletion of the gene encoding FN from young regenerating muscles replicates the aging phenotype and leads to a loss of MuSC numbers. By using an extracellular matrix (ECM) library screen and pathway profiling, we characterize FN as a preferred adhesion substrate for MuSCs and demonstrate that integrin-mediated signaling through focal adhesion kinase and the p38 mitogen-activated protein kinase pathway is strongly de-regulated in MuSCs from aged mice because of insufficient attachment to the niche. Reconstitution of FN levels in the aged niche remobilizes stem cells and restores youth-like muscle regeneration. Taken together, we identify the loss of stem cell adhesion to FN in the niche ECM as a previously unknown aging mechanism.

Output: False

Input: Consider Input: OBJECTIVE To assess the robustness of patient responses to a new national survey of patient experience as a basis for providing financial incentives to doctors.
DESIGN Analysis of the representativeness of the respondents to the GP Patient Survey compared with those who were sampled (5.5 million patients registered with 8273 general practices in England in January 2009) and with the general population. Analysis of non-response bias looked at the relation between practice response rates and scores on the survey. Analysis of the reliability of the survey estimated the proportion of the variance of practice scores attributable to true differences between practices.
RESULTS The overall response rate was 38.2% (2.2 million responses), which is comparable to that in surveys using similar methodology in the UK. Men, young adults, and people living in deprived areas were under-represented among respondents. However, for questions related to pay for performance, there was no systematic association between response rates and questionnaire scores. Two questions which triggered payments to general practitioners were reliable measures of practice performance, with average practice-level reliability coefficients of 93.2% and 95.0%. Less than 3% and 0.5% of practices had fewer than the number of responses required to achieve conventional reliability levels of 90% and 70%. A change to the payment formula in 2009 resulted in an increase in the average impact of random variation in patient scores on payments to general practitioners compared with payments made in 2007 and 2008.
CONCLUSIONS There is little evidence to support the concern of some general practitioners that low response rates and selective non-response bias have led to systematic unfairness in payments attached to questionnaire scores. The study raises issues relating to the validity and reliability of payments based on patient surveys and provides lessons for the UK and for other countries considering the use of patient experience as part of pay for performance schemes.

Output: True

Input: Consider Input: BACKGROUND Interleukin (IL)-17F, produced in IL-23R-expressing Th17 cells, is a novel member of the IL-17 cytokine family. Given the association of IL23R with inflammatory bowel disease (IBD), we characterized the role of IL-17F in IBD including its intestinal gene expression and the effect of the IL17F p. His161Arg polymorphism on disease susceptibility and phenotype of Crohn's disease (CD) and ulcerative colitis (UC). In addition, we analyzed the IL17F p. His161Arg polymorphism for potential epistasis with IL23R and NOD2/CARD15 variants.
METHODS Intestinal IL-17F mRNA expression was measured by quantitative polymerase chain reaction (PCR). Genomic DNA from 1682 individuals (CD: n = 499; UC: n = 216; controls: n = 967) was analyzed for the presence of the IL17F p. His161Arg polymorphism, the 3 NOD2 variants, p. Arg702Trp, p. Gly908Arg, and p. Leu1007fsX1008, and 10 CD-associated IL23R variants.
RESULTS Intestinal IL-17F mRNA expression was 4.4-fold increased in inflamed colonic lesions compared to uninflamed biopsies in CD (P = 0.016) but not in UC. However, the mean intestinal IL-17F mRNA expression was higher in UC than in CD (P < 0.0001). The IL17F p. His161Arg substitution was observed with similar frequencies in IBD patients and controls and was not associated with a certain disease phenotype, but weakly associated with a low body mass index (BMI; P = 0.009) and an earlier age of disease onset (P = 0.039) in UC. There was no evidence for epistasis between the IL17F p. His161Arg polymorphism and IBD-associated single nucleotide polymorphisms within the IL23R gene.
CONCLUSIONS Intestinal IL17F gene expression is increased in active CD. The IL17F p. His161Arg polymorphism is not associated with IBD susceptibility and has no epistatic interaction with CD-associated IL23R variants.
Output: True