42 research outputs found
Modelling serial order in behaviour: studies of spelling
Serial order in behaviour remains an interesting problem for computational modelling in
psychology, especially for connectionist approaches. The 'Competitive Queuing' (CQ)
approach to sequence generation has the advantage of accounting for a number of
common features apparent in several different types of serial behaviour. This thesis
addresses the general account which the CQ approach can give for constraints on serial
errors within sequences by developing models of an acquired disorder of spelling,
'graphemic buffer disorder' (GBD). Two approaches to the development of a simple
initial model of GBD into more complex models are demonstrated, and are related to
the general problem of accounting for serial category constraints in sequencing.
The initial CQ model of GBD is based on an existing model of speech production with
minimal spelling-specific changes. A number of shortcomings are identified in the
I performance of this model, in particular the inability to distinguish consonant and vowel
letters, which prevents a striking feature of GBD errors - the preservation of
consonant/vowel status - from being modelled. An analysis of the general problem of
adding domain-specific constraints to CQ models suggests two approaches to
improving the initial model. Two alternative extended models are thus advanced. The
first is a development of the initial model incorporating an external template to specify
consonant/vowel information. Simulations with this model demonstrate a much improved fit to :the data. The second model" develops a novel architecture, generalising
the CQ approach to multi-layer networks. The model is less detailed but demonstrates
the correct general features of the GBD error pattern. The relationship between the
models is discussed and possible future research directions are identified
Interactive Decision Support for Risk Management: a Qualitative Evaluation in Cancer Genetic Counselling Sessions
Genetic counselling for inherited susceptibility to cancer involves communication of a significant amount of information about possible consequences of different interventions. This study explores counsellors' attitudes to computer software designed to aid this process. Eight genetic counsellors used the software with actors playing patients. Clinicians' rating of expected patient satisfaction, content, accuracy, timeliness, format, overall value, ease of use, effect on the patient–provider relationship and effect on clinician's performance were evaluated via qualitative and quantitative analysis of interviews, training tasks and questionnaires. Most counsellors found the software effective. Concerns related to possible impact on consultation dynamics and content. Participants suggested countering these through appropriate new counselling skills and selective use of the computer. The REACT software could provide effective support for genetic risk management counselling
Assessment of variation in immunosuppressive pathway genes reveals TGFBR2 to be associated with risk of clear cell ovarian cancer
BACKGROUND: Regulatory T (Treg) cells, a subset of CD4+ T lymphocytes, are mediators of immunosuppression in cancer, and, thus, variants in genes encoding Treg cell immune molecules could be associated with ovarian cancer. METHODS: In a population of 15,596 epithelial ovarian cancer (EOC) cases and 23,236 controls, we measured genetic associations of 1,351 SNPs in Treg cell pathway genes with odds of ovarian cancer and tested pathway and gene-level associations, overall and by histotype, for the 25 genes, using the admixture likelihood (AML) method. The most significant single SNP associations were tested for correlation with expression levels in 44 ovarian cancer patients. RESULTS: The most significant global associations for all genes in the pathway were seen in endometrioid (p = 0.082) and clear cell (p = 0.083), with the most significant gene level association seen with TGFBR2 (p = 0.001) and clear cell EOC. Gene associations with histotypes at p < 0.05 included: IL12 (p = 0.005 and p = 0.008, serous and high-grade serous, respectively), IL8RA (p = 0.035, endometrioid and mucinous), LGALS1 (p = 0.03, mucinous), STAT5B (p = 0.022, clear cell), TGFBR1 (p = 0.021 endometrioid) and TGFBR2 (p = 0.017 and p = 0.025, endometrioid and mucinous, respectively). CONCLUSIONS: Common inherited gene variation in Treg cell pathways shows some evidence of germline genetic contribution to odds of EOC that varies by histologic subtype and may be associated with mRNA expression of immune-complex receptor in EOC patients
Variants in genes encoding small GTPases and association with epithelial ovarian cancer susceptibility
Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality in American women. Normal ovarian physiology is intricately connected to small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) which govern processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. We hypothesized that common germline variation in genes encoding small GTPases is associated with EOC risk. We investigated 322 variants in 88 small GTPase genes in germline DNA of 18,736 EOC patients and 26,138 controls of European ancestry using a custom genotype array and logistic regression fitting log-additive models. Functional annotation was used to identify biofeatures and expression quantitative trait loci that intersect with risk variants. One variant, ARHGEF10L (Rho guanine nucleotide exchange factor 10 like) rs2256787, was associated with increased endometrioid EOC risk (OR=1.33, p=4.46 x 10-6). Other variants of interest included another in ARHGEF10L, rs10788679, which was associated with invasive serous EOC risk (OR=1.07, p=0.00026) and two variants in AKAP6 (A-kinase anchoring protein 6) which were associated with risk of invasive EOC (rs1955513, OR=0.90, p=0.00033; rs927062, OR =0.94, p=0.00059). Functional annotation revealed that the two ARHGEF10L variants were located in super-enhancer regions and that AKAP6 rs927062 was associated with expression of GTPase gene ARHGAP5 (Rho GTPase activating protein 5). Inherited variants in ARHGEF10L and AKAP6, with potential transcriptional regulatory function and association with EOC risk, warrant investigation in independent EOC study populations
PALB2, CHEK2 and ATM rare variants and cancer risk: data from COGS
Background: The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study.Methods: We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant.Results: For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p=7.1×10−5), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p=6.9×10−8) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p=0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p≤0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p=0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p=0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants.Conclusions: This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important.</p
Identification of six new susceptibility loci for invasive epithelial ovarian cancer.
Genome-wide association studies (GWAS) have identified 12 epithelial ovarian cancer (EOC) susceptibility alleles. The pattern of association at these loci is consistent in BRCA1 and BRCA2 mutation carriers who are at high risk of EOC. After imputation to 1000 Genomes Project data, we assessed associations of 11 million genetic variants with EOC risk from 15,437 cases unselected for family history and 30,845 controls and from 15,252 BRCA1 mutation carriers and 8,211 BRCA2 mutation carriers (3,096 with ovarian cancer), and we combined the results in a meta-analysis. This new study design yielded increased statistical power, leading to the discovery of six new EOC susceptibility loci. Variants at 1p36 (nearest gene, WNT4), 4q26 (SYNPO2), 9q34.2 (ABO) and 17q11.2 (ATAD5) were associated with EOC risk, and at 1p34.3 (RSPO1) and 6p22.1 (GPX6) variants were specifically associated with the serous EOC subtype, all with P < 5 × 10(-8). Incorporating these variants into risk assessment tools will improve clinical risk predictions for BRCA1 and BRCA2 mutation carriers.COGS project is funded through a European Commission's Seventh Framework Programme grant (agreement number 223175 ] HEALTH ]F2 ]2009 ]223175). The CIMBA data management and data
analysis were supported by Cancer Research.UK grants 12292/A11174 and C1287/A10118. The Ovarian Cancer Association Consortium is supported by a grant from the Ovarian Cancer Research
Fund thanks to donations by the family and friends of Kathryn Sladek Smith (PPD/RPCI.07). The scientific development and funding for this project were in part supported by the US National Cancer Institute GAME ]ON Post ]GWAS Initiative (U19 ]CA148112). This study made use of data generated by the Wellcome Trust Case Control consortium. Funding for the project was provided by the Wellcome Trust under award 076113. The results published here are in part based upon data
generated by The Cancer Genome Atlas Pilot Project established by the National Cancer Institute and National Human Genome Research Institute (dbGap accession number phs000178.v8.p7). The cBio portal is developed and maintained by the Computational Biology Center at Memorial Sloan ] Kettering Cancer Center. SH is supported by an NHMRC Program Grant to GCT. Details of the funding of individual investigators and studies are provided in the Supplementary Note. This study made use of data generated by the Wellcome Trust Case Control consortium, funding for which was provided by the Wellcome Trust under award 076113. The results published here are, in part, based upon data generated by The Cancer Genome Atlas Pilot Project established by the National Cancerhttp://dx.doi.org/10.1038/ng.3185This is the Author Accepted Manuscript of 'Identification of six new susceptibility loci for invasive epithelial ovarian cancer' which was published in Nature Genetics 47, 164–171 (2015) © Nature Publishing Group - content may only be used for academic research
Analyses of germline variants associated with ovarian cancer survival identify functional candidates at the 1q22 and 19p12 outcome loci
We previously identified associations with ovarian cancer outcome at five genetic loci. To identify putatively causal genetic variants and target genes, we prioritized two ovarian outcome loci (1q22 and 19p12) for further study. Bioinformatic and functional genetic analyses indicated that MEF2D and ZNF100 are targets of candidate outcome variants at 1q22 and 19p12, respectively. At 19p12, the chromatin interaction of a putative regulatory element with the ZNF100 promoter region correlated with candidate outcome variants. At 1q22, putative regulatory elements enhanced MEF2D promoter activity and haplotypes containing candidate outcome variants modulated these effects. In a public dataset, MEF2D and ZNF100 expression were both associated with ovarian cancer progression-free or overall survival time. In an extended set of 6,162 epithelial ovarian cancer patients, we found that functional candidates at the 1q22 and 19p12 loci, as well as other regional variants, were nominally associated with patient outcome; however, no associations reached our threshold for statistical significance (p < 1×10-5). Larger patient numbers will be needed to convincingly identify any true associations at these loci
Towards a unified process model for graphemic buffer disorder and deep dysgraphia
Models based on the competitive queuing (CQ) approach can explain many of the effects on
dysgraphic patients\u2019 spelling attributed to disruption of the \u201cgraphemic output buffer\u201d. Situating
such a model in the wider spelling system, however, raises the question of what happens when
input to the buffer (e.g., from a semantic system) is degraded while the buffer remains intact. We
present a preliminary exploration of predictions following from the CQ approach. We show that
the CQ account of the graphemic buffer predicts and explains the finding that deep dysgraphic
patients generally show features of graphemic buffer disorder, as disrupted input from a damaged
semantic system has an inevitable effect upon the functioning of the buffer. The approach also explains
the most salient differences between the two syndromes, which are seen as consequences of the differ-
ence between an intact sequence generation system operating on degraded input versus a damaged
sequencing system operating on intact input
Spelling and serial recall: Insights from a Competitive Queueing model
ACKGROUND: Issues in Spelling Research: An Overview; Spelling Routes (or Roots or Rutes); Writing and Spelling: The View from Linguistics; SPELLING DEVELOPMENT: Sources of Information used by Beginning Spellers; The Role of Phonological and Orthographic Processes in Learning to Spell; Towards a Model of Spelling Acquisition: The Development of Some Component Skills; ABNORMAL SPELLING: Spelling Processes of the Reading Disabled; On the Development of Lexical and Non-Lexical Spelling Procedures of French-Speaking, Normal and Disabled Children; The Modularity of Reading and Spelling: Evidence from Hyperlexia; COMPUTATIONAL MODELS: Computational Approaches to Normal and Dyslexic Spelling; Representation and Connectionist Models: The NETspell Experience; REMEDIATION: Teaching Spelling: Bridging Theory and Practice; Organizing Sound and Letter Patterns for Spelling