150 research outputs found

    The attentional boost effect and perceptual degradation: Assessing the influence of attention on recognition memory

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    Supplementary material The Supplementary material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fpsyg. 2022.1024498/full#supplementary-materialFunding Financial support for this study was provided by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant awarded to BM (RGPIN-2019-07021) and open access to the published study was supported by funds from Goethe Universitaet awarded to JO.Researchers have suggested that the recognition memory effects resulting from two separate attentional manipulations—attentional boost and perceptual degradation—may share a common cause; namely a transient up-regulation of attention at the time of encoding that leads to enhanced memory performance at the time of retrieval. Prior research has demonstrated that inducing two similar transient shifts of attention simultaneously produces redundant performance in memory. In the present study, we sought to evaluate the combined influence of the attentional boost and perceptual degradation on recognition memory. If these two effects share a common cause, then we ought to observe a redundancy in memory performance, such that these two factors interact. Yet, across four experiments we fail to observe such a redundancy in recognition memory. We evaluate these results using the limited resource model of attention and speculate on how combining transient shifts of attention may produce redundant memory performance in the one case, but non-redundant performance in the other case.Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant awarded to BM (RGPIN-2019-07021)Open access to the published study was supported by funds from Goethe Universitae

    A panel of genes methylated with high frequency in colorectal cancer

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    Background: The development of colorectal cancer (CRC) is accompanied by extensive epigenetic changes, including frequent regional hypermethylation particularly of gene promoter regions. Specific genes, including SEPT9, VIM1 and TMEFF2 become methylated in a high fraction of cancers and diagnostic assays for detection of cancer-derived methylated DNA sequences in blood and/or fecal samples are being developed. There is considerable potential for the development of new DNA methylation biomarkers or panels to improve the sensitivity and specificity of current cancer detection tests. Methods: Combined epigenomic methods - activation of gene expression in CRC cell lines following DNA demethylating treatment, and two novel methods of genome-wide methylation assessment - were used to identify candidate genes methylated in a high fraction of CRCs. Multiplexed amplicon sequencing of PCR products from bisulfite-treated DNA of matched CRC and non-neoplastic tissue as well as healthy donor peripheral blood was performed using Roche 454 sequencing. Levels of DNA methylation in colorectal tissues and blood were determined by quantitative methylation specific PCR (qMSP). Results: Combined analyses identified 42 candidate genes for evaluation as DNA methylation biomarkers. DNA methylation profiles of 24 of these genes were characterised by multiplexed bisulfite-sequencing in ten matched tumor/normal tissue samples; differential methylation in CRC was confirmed for 23 of these genes. qMSP assays were developed for 32 genes, including 15 of the sequenced genes, and used to quantify methylation in tumor, adenoma and non-neoplastic colorectal tissue and from healthy donor peripheral blood. 24 of the 32 genes were methylated in \u3e50% of neoplastic samples, including 11 genes that were methylated in 80% or more CRCs and a similar fraction of adenomas. Conclusions: This study has characterised a panel of 23 genes that show elevated DNA methylation in \u3e50% of CRC tissue relative to non-neoplastic tissue. Six of these genes (SOX21, SLC6A15, NPY, GRASP, ST8SIA1 and ZSCAN18) show very low methylation in non-neoplastic colorectal tissue and are candidate biomarkers for stool-based assays, while 11 genes (BCAT1, COL4A2, DLX5, FGF5, FOXF1, FOXI2, GRASP, IKZF1, IRF4, SDC2 and SOX21) have very low methylation in peripheral blood DNA and are suitable for further evaluation as blood-based diagnostic markers

    Growth of Long Range Forward-Backward Multiplicity Correlations with Centrality in Au+Au Collisions at sNN\sqrt{s_{NN}} = 200 GeV

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    Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au+Au and p+p\textit{p+p} collisions at sNN\sqrt{s_{NN}} = 200 GeV. Strong short and long range correlations (LRC) are seen in central Au+Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short range correlations are observed in peripheral Au+Au collisions. Both the Dual Parton Model (DPM) and the Color Glass Condensate (CGC) predict the existence of the long range correlations. In the DPM the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC longitudinal color flux tubes generate the LRC. The data is in qualitative agreement with the predictions from the DPM and indicates the presence of multiple parton interactions.Comment: 6 pages, 3 figures The abstract has been slightly modifie

    Spin alignment measurements of the K0(892)K^{*0}(892) and ϕ(1020)\phi(1020) vector mesons at RHIC

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    We present the first spin alignment measurements for the K0(892)K^{*0}(892) and ϕ(1020)\phi(1020) vector mesons produced at mid-rapidity with transverse momenta up to 5 GeV/c at sNN\sqrt{s_{NN}} = 200 GeV at RHIC. The diagonal spin density matrix elements with respect to the reaction plane in Au+Au collisions are ρ00\rho_{00} = 0.32 ±\pm 0.04 (stat) ±\pm 0.09 (syst) for the K0K^{*0} (0.8<pT<5.00.8<p_T<5.0 GeV/c) and ρ00\rho_{00} = 0.34 ±\pm 0.02 (stat) ±\pm 0.03 (syst) for the ϕ\phi (0.4<pT<5.00.4<p_T<5.0 GeV/c), and are constant with transverse momentum and collision centrality. The data are consistent with the unpolarized expectation of 1/3 and thus no evidence is found for the transfer of the orbital angular momentum of the colliding system to the vector meson spins. Spin alignments for K0K^{*0} and ϕ\phi in Au+Au collisions were also measured with respect to the particle's production plane. The ϕ\phi result, ρ00\rho_{00} = 0.41 ±\pm 0.02 (stat) ±\pm 0.04 (syst), is consistent with that in p+p collisions, ρ00\rho_{00} = 0.39 ±\pm 0.03 (stat) ±\pm 0.06 (syst), also measured in this work. The measurements thus constrain the possible size of polarization phenomena in the production dynamics of vector mesons.Comment: 7 pages, 4 figures. fig.1 updated; one more reference added, one typo corrected, published in PRC.77.06190

    System-Size Independence of Directed Flow Measured at the BNL Relativistic Heavy-Ion Collider

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    We measure directed flow (ν_1) for charged particles in Au+Au and Cu+Cu collisions at √S_(NN)=200 and 62.4 GeV, as a function of pseudorapidity (η), transverse momentum (p_t), and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all available model implementations, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to ν_1 in different collision systems, and investigate possible explanations for the observed sign change in ν_1(p_t)

    Measurements of ϕ\phi meson production in relativistic heavy-ion collisions at RHIC

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    We present results for the measurement of ϕ\phi meson production via its charged kaon decay channel ϕK+K\phi \to K^+K^- in Au+Au collisions at sNN=62.4\sqrt{s_{_{NN}}}=62.4, 130, and 200 GeV, and in p+pp+p and dd+Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (y<0.5|y|<0.5) ϕ\phi meson transverse momentum (pTp_{T}) spectra in central Au+Au collisions are found to be well described by a single exponential distribution. On the other hand, the pTp_{T} spectra from p+pp+p, dd+Au and peripheral Au+Au collisions show power-law tails at intermediate and high pTp_{T} and are described better by Levy distributions. The constant ϕ/K\phi/K^- yield ratio vs beam species, collision centrality and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for ϕ\phi production at RHIC. The Ω/ϕ\Omega/\phi yield ratio as a function of pTp_{T} is consistent with a model based on the recombination of thermal ss quarks up to pT4p_{T}\sim 4 GeV/cc, but disagrees at higher transverse momenta. The measured nuclear modification factor, RdAuR_{dAu}, for the ϕ\phi meson increases above unity at intermediate pTp_{T}, similar to that for pions and protons, while RAAR_{AA} is suppressed due to the energy loss effect in central Au+Au collisions. Number of constituent quark scaling of both RcpR_{cp} and v2v_{2} for the ϕ\phi meson with respect to other hadrons in Au+Au collisions at sNN\sqrt{s_{_{NN}}}=200 GeV at intermediate pTp_{T} is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate pTp_{T} region at RHIC.Comment: 22 pages, 21 figures, 4 table

    Longitudinal double-spin asymmetry for inclusive jet production in p+p collisions at sqrt(s)=200 GeV

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    We report a new STAR measurement of the longitudinal double-spin asymmetry A_LL for inclusive jet production at mid-rapidity in polarized p+p collisions at a center-of-mass energy of sqrt(s) = 200 GeV. The data, which cover jet transverse momenta 5 < p_T < 30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit of polarized deep-inelastic scattering measurements.Comment: 7 pages, 4 figures + 1 tabl

    Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR

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    Identified charged particle spectra of π±\pi^{\pm}, K±K^{\pm}, pp and \pbar at mid-rapidity (y<0.1|y|<0.1) measured by the \dedx method in the STAR-TPC are reported for pppp and d+Au collisions at \snn = 200 GeV and for Au+Au collisions at 62.4 GeV, 130 GeV, and 200 GeV. ... [Shortened for arXiv list. Full abstract in manuscript.]Comment: 58 pages, 46 figures, 37 table

    Hadronic resonance production in dd+Au collisions at sNN\sqrt{s_{_{NN}}} = 200 GeV at RHIC

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    We present the first measurements of the ρ(770)0\rho(770)^0, KK^*(892), Δ\Delta(1232)++^{++}, Σ\Sigma(1385), and Λ\Lambda(1520) resonances in dd+Au collisions at sNN\sqrt{s_{_{NN}}} = 200 GeV, reconstructed via their hadronic decay channels using the STAR detector at RHIC. The masses and widths of these resonances are studied as a function of transverse momentum (pTp_T). We observe that the resonance spectra follow a generalized scaling law with the transverse mass (mTm_T). The ofresonancesinminimumbiascollisionsiscomparedtothe of resonances in minimum bias collisions is compared to the of π\pi, KK, and pˉ\bar{p}. The ρ0/π\rho^0/\pi^-, K/KK^*/K^-, Δ++/p\Delta^{++}/p, Σ(1385)/Λ\Sigma(1385)/\Lambda, and Λ(1520)/Λ\Lambda(1520)/\Lambda ratios in dd+Au collisions are compared to the measurements in minimum bias p+pp+p interactions, where we observe that both measurements are comparable. The nuclear modification factors (RdAuR_{dAu}) of the ρ0\rho^0, KK^*, and Σ\Sigma^* scale with the number of binary collisions (NbinN_{bin}) for pT>p_T > 1.2 GeV/cc.Comment: STAR Collaboration. Submitted to PR

    Identified baryon and meson distributions at large transverse momenta from Au+Au collisions at sNN=200\sqrt{s_{_{NN}}} = 200 GeV

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    Transverse momentum spectra of π±\pi^{\pm}, pp and pˉ\bar{p} up to 12 GeV/c at mid-rapidity in centrality selected Au+Au collisions at sNN=200\sqrt{s_{_{NN}}} = 200 GeV are presented. In central Au+Au collisions, both π±\pi^{\pm} and p(pˉ)p(\bar{p}) show significant suppression with respect to binary scaling at pT>p_T > 4 GeV/c. Protons and anti-protons are less suppressed than π±\pi^{\pm}, in the range 1.5 <pT<< p_{T} <6 GeV/c. The π/π+\pi^-/\pi^+ and pˉ/p\bar{p}/p ratios show at most a weak pTp_T dependence and no significant centrality dependence. The p/πp/\pi ratios in central Au+Au collisions approach the values in p+p and d+Au collisions at pT>p_T > 5 GeV/c. The results at high pTp_T indicate that the partonic sources of π±\pi^{\pm}, pp and pˉ\bar{p} have similar energy loss when traversing the nuclear medium.Comment: 6 pages, 4 figure
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