371 research outputs found

    Neural Indices of Vowel Discrimination in Monolingual and Bilingual Infants and Children

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    Objectives: To examine maturation of neural discriminative responses to an English vowel contrast from infancy to 4 years of age and to determine how biological factors (age and sex) and an experiential factor (amount of Spanish versus English input) modulate neural discrimination of speech. Design: Event-related potential (ERP) mismatch responses (MMRs) were used as indices of discrimination of the American English vowels [ε] versus [I] in infants and children between 3 months and 47 months of age. A total of 168 longitudinal and cross-sectional data sets were collected from 98 children (Bilingual Spanish–English: 47 male and 31 female sessions; Monolingual English: 48 male and 42 female sessions). Language exposure and other language measures were collected. ERP responses were examined in an early time window (160 to 360 msec, early MMR [eMMR]) and late time window (400 to 600 msec, late MMR). Results: The eMMR became more negative with increasing age. Language experience and sex also influenced the amplitude of the eMMR. Specifically, bilingual children, especially bilingual females, showed more negative eMMR compared with monolingual children and with males. However, the subset of bilingual children with more exposure to English than Spanish compared with those with more exposure to Spanish than English (as reported by caretakers) showed similar amplitude of the eMMR to their monolingual peers. Age was the only factor that influenced the amplitude of the late MMR. More negative late MMR was observed in older children with no difference found between bilingual and monolingual groups. Conclusions: Consistent with previous studies, our findings revealed that biological factors (age and sex) and language experience modulated the amplitude of the eMMR in young children. The early negative MMR is likely to be the mismatch negativity found in older children and adults. In contrast, the late MMR amplitude was influenced only by age and may be equivalent to the Nc in infants and to the late negativity observed in some auditory passive oddball designs

    Structures of CD6 and Its Ligand CD166 Give Insight into Their Interaction

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    SummaryCD6 is a transmembrane protein with an extracellular region containing three scavenger receptor cysteine rich (SRCR) domains. The membrane proximal domain of CD6 binds the N-terminal immunoglobulin superfamily (IgSF) domain of another cell surface receptor, CD166, which also engages in homophilic interactions. CD6 expression is mainly restricted to T cells, and the interaction between CD6 and CD166 regulates T-cell activation. We have solved the X-ray crystal structures of the three SRCR domains of CD6 and two N-terminal domains of CD166. This first structure of consecutive SRCR domains reveals a nonlinear organization. We characterized the binding sites on CD6 and CD166 and showed that a SNP in CD6 causes glycosylation that hinders the CD6/CD166 interaction. Native mass spectrometry analysis showed that there is competition between the heterophilic and homophilic interactions. These data give insight into how interactions of consecutive SRCR domains are perturbed by SNPs and potential therapeutic reagents

    Spitzer Photometry of WISE-Selected Brown Dwarf and Hyper-Luminous Infrared Galaxy Candidates

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    We present Spitzer 3.6 and 4.5 μ\mum photometry and positions for a sample of 1510 brown dwarf candidates identified by the WISE all-sky survey. Of these, 166 have been spectroscopically classified as objects with spectral types M(1), L(7), T(146), and Y(12); Sixteen other objects are non-(sub)stellar in nature. The remainder are most likely distant L and T dwarfs lacking spectroscopic verification, other Y dwarf candidates still awaiting follow-up, and assorted other objects whose Spitzer photometry reveals them to be background sources. We present a catalog of Spitzer photometry for all astrophysical sources identified in these fields and use this catalog to identify 7 fainter (4.5 μ\mum \sim 17.0 mag) brown dwarf candidates, which are possibly wide-field companions to the original WISE sources. To test this hypothesis, we use a sample of 919 Spitzer observations around WISE-selected high-redshift hyper-luminous infrared galaxy (HyLIRG) candidates. For this control sample we find another 6 brown dwarf candidates, suggesting that the 7 companion candidates are not physically associated. In fact, only one of these 7 Spitzer brown dwarf candidates has a photometric distance estimate consistent with being a companion to the WISE brown dwarf candidate. Other than this there is no evidence for any widely separated (>> 20 AU) ultra-cool binaries. As an adjunct to this paper, we make available a source catalog of \sim 7.33 ×105\times 10^5 objects detected in all of these Spitzer follow-up fields for use by the astronomical community. The complete catalog includes the Spitzer 3.6 and 4.5 μ\mum photometry, along with positionally matched BB and RR photometry from USNO-B; JJ, HH, and KsK_s photometry from 2MASS; and W1W1, W2W2, W3W3, and W4W4 photometry from the WISE all-sky catalog

    ART adherence changes among patients in community substance use treatment: a preliminary analysis from MACH14

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    Abstract Background Opiate substitution treatment has been associated with better adherence to lifesaving antiretroviral medications, but the impact of other substance abuse treatment on adherence is unknown. Findings In this study, 215 patients who had been in adherence-focused research studies provided electronically-measured adherence data and a measure of whether the patient had recently been in substance abuse treatment. Recent engagement in substance abuse treatment was independently associated with significantly higher adherence, after covarying for recent substance use and other factors potentially affecting adherence. Conclusions The findings suggest that substance abuse treatment is associated with better adherence. Potential mechanisms by which substance abuse treatment improves adherence, such as more stability or more future-orientation, require further study

    High-resolution deconstruction of evolution induced by chemotherapy treatments in breast cancer xenografts.

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    The processes by which tumors evolve are essential to the efficacy of treatment, but quantitative understanding of intratumoral dynamics has been limited. Although intratumoral heterogeneity is common, quantification of evolution is difficult from clinical samples because treatment replicates cannot be performed and because matched serial samples are infrequently available. To circumvent these problems we derived and assayed large sets of human triple-negative breast cancer xenografts and cell cultures from two patients, including 86 xenografts from cyclophosphamide, doxorubicin, cisplatin, docetaxel, or vehicle treatment cohorts as well as 45 related cell cultures. We assayed these samples via exome-seq and/or high-resolution droplet digital PCR, allowing us to distinguish complex therapy-induced selection and drift processes among endogenous cancer subclones with cellularity uncertaint

    ART adherence changes among patients in community substance use treatment: a preliminary analysis from MACH14

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    Background: Opiate substitution treatment has been associated with better adherence to lifesaving antiretroviral medications, but the impact of other substance abuse treatment on adherence is unknown. Findings: In this study, 215 patients who had been in adherence-focused research studies provided electronically-measured adherence data and a measure of whether the patient had recently been in substance abuse treatment. Recent engagement in substance abuse treatment was independently associated with significantly higher adherence, after covarying for recent substance use and other factors potentially affecting adherence. Conclusions: The findings suggest that substance abuse treatment is associated with better adherence. Potential mechanisms by which substance abuse treatment improves adherence, such as more stability or more future-orientation, require further study
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