77 research outputs found

    16.3 Are Visual Motion Perception and Detection of Animacy Critical to Higher-Order Social Cognitive Function in Schizophrenia?

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    Background The observation that individuals with schizophrenia tend to misinterpret subtle social cues is often attributed to deficit in Theory of Mind (ToM). While ToM is commonly assessed using videos portraying interaction between actors, recent work in vision science shows that stimuli with no innate animate features can also convey similar social information through motion alone. These simplified stimuli are advantageous for experimental purposes and may provide further insights into perceptual mechanisms supporting social cognitive function. The Social Attribution Task-Multiple Choice (SAT-MC), based on the classic Hieder and Simmel (1944) stimuli, tells a story using three geometric shapes moving about a centrally fixed figure, followed by questions about what the viewer observed. Although there are no explicit social cues, viewers typically detect actions suggestive of relationships between objects, their intentions, and emotions. This talk will present findings from three studies examining psychometric, functional, and neurophysiological aspects on SAT -MC performance in schizophrenia. Methods Study 1 examined psychometric properties of two forms of the SAT-MC in comparison to video-based social cognitive tests using human actors in 32 schizophrenia (SZ) and 30 substance use disorder (SUD) participants. Study 2 examined functional relationships of the SAT-MC and affect recognition (BLERT) performance across neurocognitive, metacognitive, ToM, and symptom domains in 72 adults with SZ. Study 3 is an in-progress investigation of neurophysiological mechanisms of social cognition using test versions adapted for EEG recording. Chronic SZ, clinical high-risk (CHR), and healthy age-matched community samples are being collected. Results SZ scored significantly lower than SUD on two versions of the SAT-MC, each classifying ~60% of SZ as impaired, compared with ~30% of SUD. The two SAT-MC forms demonstrated good test-retest and parallel form reliability, minimal practice effect, high internal consistency, similar patterns of correlation with social cognitive test performance, and compared favorably to social cognitive tests across psychometric features. When examining functional correlates of SAT -MC performance, impairment is found to co-occur with deficits in affect recognition in the majority of cases but relates uniquely to reductions in verbal memory and emotional intelligence measures. Finally, a preliminary analysis (n=8 SZ, n=2 CHR) of EEG collected during SAT-MC video presentation finds significant correlations (r=.66-.72) between occipito-parietal gamma desynchronization and task performance. Additional analyses find task-related EEG during SAT to be predictive of affect recognition (BLERT) and ToM (TASIT) performance, with correlates including alpha desynchronization in frontal, occipital, and temporal regions, and synchronization of temporal theta and occipital gamma (all r > .5). Conclusions SAT-MC performance is found to be reliable using different stimuli, related to affect recognition and ToM in three independent samples, and shows high diagnostic specificity in classifying SZ against a SUD sample. Functional correlates also involve encoding and emotional intelligence abilities tested outside the visual modality. Analysis of neural oscillatory activity related SAT-MC performance to visual and attention processes, as well as engagement of a broader social cognitive network applied to affect recognition and ToM tasks. Impairment in visual motion processing appears integral to schizophrenia pathophysiology and a critical factor influencing social cognitive abilities attributed to higher-order ToM ability

    Developing Tracer Particles for X-Ray Particle Tracking Velocimetry

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    X-ray imaging, as a noninvasive flow visualization technique, has been shown to be a useful method for observing and characterizing multiphase flows. One type of X-ray flow visualization technique, called X-ray Particle Tracking Velocimetry (XPTV), tracks an X-ray attenuating particle in an opaque fluid flow. A significant challenge with XPTV is identifying tracer particles with the desired fluid flow characteristics (e.g., small and neutrally buoyant) but yet differentially attenuate X-rays, which is based primarily on density differences. This paper describes the manufacturing of XPTV tracer particles that satisfy specific particle characteristics including high X-ray attenuation, uniform shape, specified effective density, and desired diameter. An example use of these particles as an intruder particle in a fluidized bed (to simulate biomass injection) is then demonstrated using X-ray stereographic imaging to determine intruder particle position as a function of time in a three-dimensional opaque system

    Time-Dependent Photoluminescence and Photoluminescence Excitation in Exciton Systems and Related Phenomena

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    The term “exciton” covers an extremely diverse range of materials, phenomena, processes, interactions, and experimental techniques. This review provides a general introduction-with selected descriptive examples-of excitonic systems with an emphasis on excitonic photoluminescence and photoexcitation spectroscopy in the ultrafast time-resolved femtosecond time domain

    Values of the Federal Public Lands

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    v, 158 p. ; 28 cmhttps://scholar.law.colorado.edu/books_reports_studies/1038/thumbnail.jp

    Nos2 Inactivation Promotes the Development of Medulloblastoma in Ptch1+/− Mice by Deregulation of Gap43–Dependent Granule Cell Precursor Migration

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    Medulloblastoma is the most common malignant brain tumor in children. A subset of medulloblastoma originates from granule cell precursors (GCPs) of the developing cerebellum and demonstrates aberrant hedgehog signaling, typically due to inactivating mutations in the receptor PTCH1, a pathomechanism recapitulated in Ptch1+/− mice. As nitric oxide may regulate GCP proliferation and differentiation, we crossed Ptch1+/− mice with mice lacking inducible nitric oxide synthase (Nos2) to investigate a possible influence on tumorigenesis. We observed a two-fold higher medulloblastoma rate in Ptch1+/− Nos2−/− mice compared to Ptch1+/− Nos2+/+ mice. To identify the molecular mechanisms underlying this finding, we performed gene expression profiling of medulloblastomas from both genotypes, as well as normal cerebellar tissue samples of different developmental stages and genotypes. Downregulation of hedgehog target genes was observed in postnatal cerebellum from Ptch1+/+ Nos2−/− mice but not from Ptch1+/− Nos2−/− mice. The most consistent effect of Nos2 deficiency was downregulation of growth-associated protein 43 (Gap43). Functional studies in neuronal progenitor cells demonstrated nitric oxide dependence of Gap43 expression and impaired migration upon Gap43 knock-down. Both effects were confirmed in situ by immunofluorescence analyses on tissue sections of the developing cerebellum. Finally, the number of proliferating GCPs at the cerebellar periphery was decreased in Ptch1+/+ Nos2−/− mice but increased in Ptch1+/− Nos2−/− mice relative to Ptch1+/− Nos2+/+ mice. Taken together, these results indicate that Nos2 deficiency promotes medulloblastoma development in Ptch1+/− mice through retention of proliferating GCPs in the external granular layer due to reduced Gap43 expression. This study illustrates a new role of nitric oxide signaling in cerebellar development and demonstrates that the localization of pre-neoplastic cells during morphogenesis is crucial for their malignant progression

    Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

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    Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

    Preventive Dental Care and Unmet Dental Needs Among Low-Income Children

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    Objectives. We examined the ways in which levels of preventive dental care and unmet dental needs varied among subgroups of low-income children. Methods. Data were drawn from the 2002 National Survey of America’s Families. We conducted bivariate and multivariate analyses, including logistic regression analyses, to assess relationships between socioeconomic, demographic, and health factors and receipt of preventive dental care and unmet dental needs. Results. More than half of low-income children without health insurance had no preventive dental care visits. Levels of unmet dental needs among low-income children who had private health insurance coverage but no dental benefits were similar to those among uninsured children. Children of parents whose mental health was rated as poor were twice as likely to have unmet dental needs as other children. Conclusions. Additional progress toward improving the dental health of low-income children depends on identifying and responding to factors limiting both the demand for and the supply of dental services. In particular, it appears that expanding access to dental benefits is key to improving the oral health of this population
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