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Search Results: 1 - 10 of 9820 matches for " and Patrick Concannon "
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Prospective Teachers’ Perceptions of Science Theories: An Action Research Study  [PDF]
James P. Concannon, Patrick L. Brown, Erikka Brown
Creative Education (CE) , 2013, DOI: 10.4236/ce.2013.41011
Abstract: This study investigates prospective teachers’ conceptions of science theories before and after instruction. Instruction focused specifically on prospective teachers’ misconceptions that theories are not used to predict, that laws are more important than theories, and that theories are simply hunches. The action research investigation was successful in helping students accommodate new information presented in the lesson and facilitated their understanding towards the accepted explanation of what a theory in science means; however, the vernacular misconception that “theories are hunches” persisted.
The role of X-chromosome inactivation in female predisposition to autoimmunity
Smita Chitnis, Joanita Monteiro, David Glass, Brian Apatoff, Jane Salmon, Patrick Concannon, Peter K Gregersen
Arthritis Research & Therapy , 2000, DOI: 10.1186/ar118
Abstract: A reduction in the sex ratio (male : female) is characteristic of most autoimmune disorders. The increased prevalence in females ranges from a modest 2:1 for multiple sclerosis [1], to approximately 10:1 for systemic lupus erythematosus [2]. This tendency toward autoimmunity in females is often ascribed to hormonal differences, because in a number of experimental disease models estrogens exacerbated disease, and androgens can inhibit disease activity [3,4]. However, human studies have failed to demonstrate a clear-cut influence of hormonal environment on disease susceptibility to lupus or other autoimmune disorders. In addition, many childhood forms of autoimmunity, such as juvenile rheumatoid arthritis, exhibit female predominance [5]. Interestingly, juvenile (type 1) diabetes is an exception to this general trend, with a sex ratio close to 1 in most studies [6]. Therefore, it is reasonable to consider alternative explanations for the increased prevalence of autoimmune diseases in human females.A unifying feature of autoimmune disorders appears to be the loss of immunologic tolerance to self-antigens, and in many of these diseases there is evidence that T-cell tolerance has been broken. The most profound form of T-cell tolerance involves deletion of potentially self-reactive T cells during thymic selection. Thus, lack of exposure to a self-antigen in the thymus may lead to the presence of autoreactive T cells and may increase the risk of autoimmunity. An elegant example of this has recently been reported [7].The existence of X-chromosome inactivation in females offers a potential mechanism whereby X-linked self-antigens may escape presentation in the thymus or in other peripheral sites that are involved in tolerance induction. Early in female development, one of the two X chromosomes in each cell undergoes an ordered process of inactivation, with subsequent silencing of most genes on the inactive X chromosome [8]. This phenomenon occurs at a very early embryonic st
ATM mutations associated with breast cancer
RA Gatti, P Concannon
Breast Cancer Research , 2005, DOI: 10.1186/bcr1048
Abstract: These efforts were partially funded by NIH grant NS35322 and the A-T Medical Research Foundation, Los Angeles, California, USA.
Imputing Amino Acid Polymorphisms in Human Leukocyte Antigens
Xiaoming Jia, Buhm Han, Suna Onengut-Gumuscu, Wei-Min Chen, Patrick J. Concannon, Stephen S. Rich, Soumya Raychaudhuri, Paul I.W. de Bakker
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0064683
Abstract: DNA sequence variation within human leukocyte antigen (HLA) genes mediate susceptibility to a wide range of human diseases. The complex genetic structure of the major histocompatibility complex (MHC) makes it difficult, however, to collect genotyping data in large cohorts. Long-range linkage disequilibrium between HLA loci and SNP markers across the major histocompatibility complex (MHC) region offers an alternative approach through imputation to interrogate HLA variation in existing GWAS data sets. Here we describe a computational strategy, SNP2HLA, to impute classical alleles and amino acid polymorphisms at class I (HLA-A, -B, -C) and class II (-DPA1, -DPB1, -DQA1, -DQB1, and -DRB1) loci. To characterize performance of SNP2HLA, we constructed two European ancestry reference panels, one based on data collected in HapMap-CEPH pedigrees (90 individuals) and another based on data collected by the Type 1 Diabetes Genetics Consortium (T1DGC, 5,225 individuals). We imputed HLA alleles in an independent data set from the British 1958 Birth Cohort (N = 918) with gold standard four-digit HLA types and SNPs genotyped using the Affymetrix GeneChip 500 K and Illumina Immunochip microarrays. We demonstrate that the sample size of the reference panel, rather than SNP density of the genotyping platform, is critical to achieve high imputation accuracy. Using the larger T1DGC reference panel, the average accuracy at four-digit resolution is 94.7% using the low-density Affymetrix GeneChip 500 K, and 96.7% using the high-density Illumina Immunochip. For amino acid polymorphisms within HLA genes, we achieve 98.6% and 99.3% accuracy using the Affymetrix GeneChip 500 K and Illumina Immunochip, respectively. Finally, we demonstrate how imputation and association testing at amino acid resolution can facilitate fine-mapping of primary MHC association signals, giving a specific example from type 1 diabetes.
Cyber Terrorism
Kevin Curran,Kevin Concannon,Sean Mc Keever
Asian Journal of Information Technology , 2012,
Abstract: Cyber terrorism is the premeditated, politically motivated attacks against information, computer systems, computer programs, and data which result in violence against non-combatant targets by sub-national groups or clandestine agents. This study provides a brief overview of previous cyber terrorism attacks and government responses.
Spatiotemporally complete condensation in a non-Poissonian exclusion process
R. J. Concannon,R. A. Blythe
Physics , 2013, DOI: 10.1103/PhysRevLett.112.050603
Abstract: We investigate a non-Poissonian version of the asymmetric simple exclusion process, motivated by the observation that coarse-graining the interactions between particles in complex systems generically leads to a stochastic process with a non-Markovian (history-dependent) character. We characterize a large family of one-dimensional hopping processes using a waiting-time distribution for individual particle hops. We find that when its variance is infinite, a real-space condensate forms that is complete in space (involves all particles) and time (exists at almost any given instant) in the thermodynamic limit. The mechanism for the onset and stability of the condensate are both rather subtle, and depends on the microscopic dynamics subsequent to a failed particle hop attempts.
Single nucleotide polymorphisms associated with risk for contralateral breast cancer in the Women's Environment, Cancer, and Radiation Epidemiology (WECARE) Study
Sharon N Teraoka, Jonine L Bernstein, Anne S Reiner, Robert W Haile, Leslie Bernstein, Charles F Lynch, Kathleen E Malone, Marilyn Stovall, Marinela Capanu, Xiaolin Liang, Susan A Smith, Josyf Mychaleckyj, Xuanlin Hou, Lene Mellemkjaer, John D Boice, Ashley Siniard, David Duggan, Duncan C Thomas, The WECARE Study Collaborative Group, and Patrick Concannon
Breast Cancer Research , 2011, DOI: 10.1186/bcr3057
Abstract: We genotyped 21 SNPs in 708 women with contralateral breast cancer and 1394 women with unilateral breast cancer who serve as the cases and controls in the Women's Environment, Cancer and Radiation Epidemiology (WECARE) Study. Records of treatment and ER status were available for most of WECARE Study participants. Associations of SNP genotypes and risk for contralateral breast cancer were calculated with multivariable adjusted conditional logistic regression methods.Multiple SNPs in the FGFR2 locus were significantly associated with contralateral breast cancer, including rs1219648 (per allele rate ratio (RR) = 1.25, 95%CI = 1.08-1.45). Statistically significant associations with contralateral breast cancer were also observed at rs7313833, near the PTHLH gene (per allele RR = 1.26, 95%CI = 1.08-1.47), rs13387042 (2q35) (per allele RR = 1.19, 95%CI = 1.02-1.37), rs13281615 (8q24) (per allele RR = 1.21, 95%CI = 1.04-1.40), and rs11235127 near TMEM135 (per allele RR = 1.26, 95%CI = 1.04-1.53). The A allele of rs13387042 (2q35) was significantly associated with contralateral breast cancer in ER negative first tumors while the A allele of rs11235127 (near TMEM135) was significantly associated with contralateral breast cancer in ER positive first tumors. Although some SNP genotypes appeared to modify contralateral breast cancer risk with respect to tamoxifen treatment or particular radiation doses, trend tests for such effects were not significant.Our results indicate that some common risk variants associated with primary breast cancer also increase risk for contralateral breast cancer, and that these risks vary with the ER status of the first tumor.Patients with breast cancer are two to five times more likely to develop a second primary cancer in the contralateral breast than are unaffected women to develop an initial breast cancer [1-4]. Established risk factors for asynchronous second primary contralateral breast cancer (CBC) include those suggesting a genetic basis, suc
Study design: Evaluating gene–environment interactions in the etiology of breast cancer – the WECARE study
Jonine L Bernstein, Bryan Langholz, Robert W Haile, Leslie Bernstein, Duncan C Thomas, Marilyn Stovall, Kathleen E Malone, Charles F Lynch, J?rgen H Olsen, Hoda Anton-Culver, Roy E Shore, John D Boice, Gertrud S Berkowitz, Richard A Gatti, Susan L Teitelbaum, Susan A Smith, Barry S Rosenstein, Anne-Lise B?rresen-Dale, Patrick Concannon, W Douglas Thompson
Breast Cancer Research , 2004, DOI: 10.1186/bcr771
Abstract: To examine the joint roles of radiation exposure and genetic susceptibility in the etiology of breast cancer, we designed a case-control study nested within five population-based cancer registries. We hypothesized that a woman carrying a mutant allele in one of these genes is more susceptible to radiation-induced breast cancer than is a non-carrier. In our study, 700 women with asynchronous bilateral breast cancer were individually matched to 1400 controls with unilateral breast cancer on date and age at diagnosis of the first breast cancer, race, and registry region, and counter-matched on radiation therapy. Each triplet comprised two women who received radiation therapy and one woman who did not. Radiation absorbed dose to the contralateral breast after initial treatment was estimated with a comprehensive dose reconstruction approach that included experimental measurements in anthropomorphic and water phantoms applying patient treatment parameters. Blood samples were collected from all participants for genetic analyses.Our study design improves the potential for detecting gene–environment interactions for diseases when both gene mutations and the environmental exposures of interest are rare in the general population. This is particularly applicable to the study of bilateral breast cancer because both radiation dose and genetic susceptibility have important etiologic roles, possibly by interactive mechanisms. By using counter-matching, we optimized the informativeness of the collected dosimetry data by increasing the variability of radiation dose within the case–control sets and enhanced our ability to detect radiation–genotype interactions.The WECARE (for Women's Environmental Cancer and Radiation Epidemiology) Study is a multi-center, population-based case-control study of breast cancer designed to examine the interaction of gene carrier status and radiation exposure in the etiology of breast cancer. We are currently focusing on three major breast cancer suscepti
Star formation histories of early-type galaxies. I: Higher order Balmer lines as age indicators
Nelson Caldwell,James A. Rose,Kristi Dendy Concannon
Physics , 2003, DOI: 10.1086/375308
Abstract: (shortened) We have obtained blue integrated spectra of 175 nearby early-type galaxies, covering a wide range in galaxy velocity dispersion, and emphasizing those with sigma < 100 km/s. Galaxies have been observed both in the Virgo cluster and in lower-density environments. The main goals are the evaluation of higher order Balmer lines as age indicators, and differences in stellar populations as a function of mass, environment and morphology. In this first paper our emphasis is on presenting the evolutionary population synthesis models. Lower-sigma galaxies exhibit a substantially greater intrinsic scatter, in a variety of line strength indicators, than do higher-sigma galaxies, with the large intrinsic scatter setting in below a sigma of 100 km/s. Modeling of the observed spectral indices indicates that the strong Balmer lines found primarily among the low-sigma galaxies are caused by young age, rather than by low metallicity. Thus we find a trend between the population age and the velocity dispersion, such that low sigma galaxies have younger luminosity-weighted mean ages. We have repeated this analysis using several different Balmer lines, and find consistent results from one spectral indicator to another.
Spectral Variations in Early-Type Galaxies as a Function of Mass
K. D. Concannon,J. A. Rose,N. Caldwell
Physics , 2000, DOI: 10.1086/312727
Abstract: We report on the strengths of three spectral indicators - Mg_2, Hbeta, and Hn/Fe - in the integrated light of a sample of 100 field and cluster E/S0 galaxies. The measured indices are sensitive to age and/or and metallicity variations within the galaxy sample. Using linear regression analysis for data with non-uniform errors, we determine the intrinsic scatter present among the spectral indices of our galaxy sample as a function of internal velocity dispersion. Our analysis indicates that there is significantly more intrinsic scatter in the two Balmer line indices than in the Mg_2 index, indicating that the Balmer indices provide more dynamic range in determining the age of a stellar population than does the Mg_2 index. Furthermore, the scatter is much larger for the low velocity dispersion galaxies, indicating that star formation has occurred more recently in the lower mass galaxies.
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