2,097 research outputs found
Probing the host galaxy of a luminous quasar
Mathematical and Physical Sciences: 3rd Place (The Ohio State University Edward F. Hayes Graduate Research Forum)We present a study of PG 1426+015, a quasar and host galaxy system at a distance of 1.3 billion light years. Quasars are intrinsically bright objects found at the center of 0.1% of local galaxies. With luminosities greater than 30 billion times that of our Sun, quasars must be powered by an exceptionally energetic phenomenon: the accretion of matter onto a black hole more than ten million times as massive as our Sun. The science goal of our study is to place PG 1426+015 on the M-sigma relation --- an empirical correlation between the mass of the central black hole (M) and the stellar velocity dispersion of the host galaxy (sigma). The velocity dispersion is a measure of the average random velocity of stars in a galaxy; typically more massive galaxies have larger velocity dispersions. The M-sigma relation implies that the growth of the central black hole and the stellar component of a galaxy is synchronized. This is an area of intensive research because a well-accepted theory explaining the M-sigma relation has not yet emerged. In our work, we focus on populating the high-mass end of the relation with luminous quasars because these objects are often extreme in their black hole masses and accretion rates. Previous work investigating luminous quasars on the M-sigma relation was limited by low-precision velocity dispersions. This is a symptom of the general challenge of quasar host galaxy studies: a quasar typically outshines its host galaxy by a factor of about ten. To circumvent this challenge, we obtained data using a combination of state of the art instrumentation available at the Gemini North telescope located on the summit of Mauna Kea in Hawaii: the Near-Infrared Integral Field Spectrometer (NIFS) and the recently installed Altair Laser Guide Star adaptive optics system. The technical goal of our study is to determine whether this combination of instrumentation is an aid to host galaxy studies of luminous quasars.No embarg
Roles in E-Science for Health and Science Librarians
Presentation to science librarians about library roles in e-science and data services, and the University of Minnesota libraries\u27 approach to meeting these needs for their institution
Fathers\u27 and Mothers\u27 Verbal Responsiveness and the Language Skills of Young Children With Autism Spectrum Disorder
Purpose: In this observational study, we examined the interactions of 16 young children with autism spectrum disorder (ASD) and their parents to investigate (a) differences in verbal responsiveness used by fathers and mothers in interactions with their children with ASD and (b) concurrent associations between the language skills of children with ASD and the verbal responsiveness of both fathers and mothers.
Method: Parent verbal responsiveness was coded from video recordings of naturalistic parent–child play sessions using interval-based coding. Child language skills were measured by the Preschool Language Scale–Fourth Edition (Zimmerman, Steiner, & Pond, 2002).
Results: For both fathers and mothers, parent verbal responsiveness was positively associated with child language skills. Mothers\u27 responsiveness was also significantly associated with child cognition. After controlling for child cognition, fathers\u27 verbal responsiveness continued to be significantly related to child language skills.
Conclusions: Although other studies have documented associations between mothers\u27 responsiveness and child language, this is the 1st study to document a significant concurrent association between child language skills of children with ASD and the verbal responsiveness of fathers. Findings of this study warrant the inclusion of fathers in future research on language development and intervention to better understand the potential contributions fathers may make to language growth for children with ASD over time as well as to determine whether coaching fathers to use responsive verbal strategies can improve language outcomes for children with ASD
Joint attention revisited: Finding strengths among children with autism
Differences in joint attention (JA) are prominent for some children with autism and are often used as an indicator of the disorder. This study examined the JA competencies of young children with autism who demonstrated JA ability and compared them to children with developmental delays. Method: Forty children with autism and developmental delays were matched pairwise based on mental and chronological age. Videos of children engaging in play were coded for the frequency and forms (eye contact, gestures, affect, etc.) of JA. Additionally, concurrent language was compared among children with autism (N=32) by their JA ability. Results: Children with ASD entered into JA significantly less often than children with DD but once engaged, used the forms of JA similarly. For the matched pairs there were no differences in language but the children with autism who used JA had significantly better language than children with autism who did not (even after controlling for mental age). Conclusions: There is a group of young children with autism who can use JA but do so at lower frequencies than children with DD. Possible reasons include difficulty disengaging attention and limited intrinsic social motivation to share. Adult persistence is recommended to encourage JA
Parental Broad Autism Phenotype and the Language Skills of Children with Autism Spectrum Disorder
Father–child and mother–child interactions were examined in order to investigate concurrent associations between three characteristics of parental broad autism phenotype (i.e., aloofness, rigidity, pragmatic language deficits), parental verbal responsiveness, and language skills of children with ASD. Results for mothers indicated that aloofness and rigidity were negatively associated with both child-initiated engagement and child language skills. Maternal aloofness was also negatively correlated with verbal responsiveness to their children, but rigidity was not. Results suggest that the association between aloofness and child language are potentially mediated by maternal use of responsive verbal behaviors. Maternal pragmatic language deficits were not concurrently related to child-initiated engagement or language skills. In contrast, for fathers, aloofness and rigidity were unrelated to child-initiated engagement and language skills. Paternal pragmatic deficits were also not associated with child language, however significant positive associations were found between paternal pragmatic language deficits and frequency of child-initiated engagement. Results are discussed in reference to potential clinical implications and directions for future research
“I Didn’t See It as a Cultural Thing”: Supervisors of Student Teachers Define and Describe Culturally Responsive Supervision
Student teaching supervisors can play an integral role in teacher candidates’ ability to understand and enact culturally responsive pedagogy (CRP). However, supervisors may lack the awareness, knowledge, skill, or willingness to serve as culturally responsive supervisors. This paper reports the findings from a qualitative study to find out how supervisors described and supported CRP. We found that supervisors hold unsophisticated views of CRP and face the following challenges enacting culturally responsive supervision: feelings of inadequacy, difficulty talking about race, color-blind orientations, and a tendency to purposefully avoid race talk. We provide recommendations for professional development to address these challenges and narrow the theory-to-practice divide in order to promote the democratic education ideals of equality and justice in our schools
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