4,038 research outputs found

    Development of Body Emotion Perception in Infancy: From Discrimination to Recognition

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    Research suggests that infants progress from discrimination to recognition of emotions in faces during the first half year of life. It is unknown whether the perception of emotions from bodies develops in a similar manner. In the current study, when presented with happy and angry body videos and voices, 5-month-olds looked longer at the matching video when they were presented upright but not when they were inverted. In contrast, 3.5-month-olds failed to match even with upright videos. Thus, 5-month-olds but not 3.5-month-olds exhibited evidence of recognition of emotions from bodies by demonstrating intermodal matching. In a subsequent experiment, younger infants did discriminate between body emotion videos but failed to exhibit an inversion effect, suggesting that discrimination may be based on low-level stimulus features. These results document a developmental change from discrimination based on non-emotional information at 3.5 months to recognition of body emotions at 5 months. This pattern of development is similar to face emotion knowledge development and suggests that both the face and body emotion perception systems develop rapidly during the first half year of life

    Effects of an Unusual Poison Identify a Lifespan Role for Topoisomerase 2 in Saccharomyces Cerevisiae

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    A progressive loss of genome maintenance has been implicated as both a cause and consequence of aging. Here we present evidence supporting the hypothesis that an age-associated decay in genome maintenance promotes aging in Saccharomyces cerevisiae (yeast) due to an inability to sense or repair DNA damage by topoisomerase 2 (yTop2). We describe the characterization of LS1, identified in a high throughput screen for small molecules that shorten the replicative lifespan of yeast. LS1 accelerates aging without affecting proliferative growth or viability. Genetic and biochemical criteria reveal LS1 to be a weak Top2 poison. Top2 poisons induce the accumulation of covalent Top2-linked DNA double strand breaks that, if left unrepaired, lead to genome instability and death. LS1 is toxic to cells deficient in homologous recombination, suggesting that the damage it induces is normally mitigated by genome maintenance systems. The essential roles of yTop2 in proliferating cells may come with a fitness trade-off in older cells that are less able to sense or repair yTop2-mediated DNA damage. Consistent with this idea, cells live longer when yTop2 expression levels are reduced. These results identify intrinsic yTop2-mediated DNA damage as a potentially manageable cause of aging

    Tuning the magnetic ground state of Ce1−xYbxRhIn5 by Yb valence fluctuations

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    We characterize the properties of Ce1−xYbxRhIn5 single crystals with 0 ⩽ x ⩽ 1 using measurements of powder x-ray diffraction, energy dispersive x-ray spectroscopy, electrical resistivity, magnetic susceptibility, specific heat, x-ray absorption near edge structure (XANES), and neutron diffraction. The Yb valence vYb, calculated from the magnetic susceptibility and measured using XANES, decreases from 3+ at x = 0 to ∼2.1+ at xact = 0.2, where xact is the measured Yb concentration. A transition from incommensurate to commensurate antiferromagnetism is observed in neutron diffraction measurements along Q = (0.5, 0.5, l) between 0.2 ⩽ xact ⩽ 0.27; this narrative is supported by specific-heat measurements in which a second robust feature appears at a temperature TI (TI \u3c TN) for the same concentration range. Magnetic susceptibility measurements also reveal features which provide additional evidence of magnetic ordering. The results of this study suggest that the evolution of the Yb valence plays a critical role in tuning the magnetic ground state of Ce1−xYbxRhIn5

    Mutant U2AF1-induced alternative splicing of H2afy (macroH2A1) regulates B-lymphopoiesis in mice

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    Somatic mutations in spliceosome genes are found in ∼50% of patients with myelodysplastic syndromes (MDS), a myeloid malignancy associated with low blood counts. Expression of the mutant splicing factor U2AF1(S34F) alters hematopoiesis and mRNA splicing in mice. Our understanding of the functionally relevant alternatively spliced target genes that cause hematopoietic phenotypes in vivo remains incomplete. Here, we demonstrate that reduced expression of H2afy1.1, an alternatively spliced isoform of the histone H2A variant gene H2afy, is responsible for reduced B cells in U2AF1(S34F) mice. Deletion of H2afy or expression of U2AF1(S34F) reduces expression of Ebf1 (early B cell factor 1), a key transcription factor for B cell development, and mechanistically, H2AFY is enriched at the EBF1 promoter. Induced expression of H2AFY1.1 in U2AF1(S34F) cells rescues reduced EBF1 expression and B cells numbers in vivo. Collectively, our data implicate alternative splicing of H2AFY as a contributor to lymphopenia induced by U2AF1(S34F) in mice and MDS

    From Cosmetic to Metabolized Change: Promoting Paradigm Shifts in a Dominant Culture University

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    The authors provide three case examples modeling the implementation of the Diversity agenda in a school of education within a private Christian university. The second article in a series, the case studies demonstrate contextual application of confronting privilege as it manifests itself in a seemingly homogeneous environment. As the authors document programmatic, personal, and pedagogical methods informed by principles of social justice and equity, the intent is to move beyond cosmetic compliance with accreditation obligations towards a metabolized second order change within students and faculty

    Ferromagnetism in Electronic Models for Manganites

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    Ground state properties of the Kondo model for manganese oxides in one dimension are studied using numerical techniques. The large Hund coupling (JHJ_{H}) limit is specially analyzed. A robust region of fully saturated ferromagnetism (FM) is identified at all densities. For open boundary conditions it is shown exactly that the ground state is FM at JH=∞J_{H} = \infty. Hole-spin phase separation competing with FM was also observed when a large exchange JJ between the Mn3+Mn^{3+} ions is used. As the spin of the transition metal ion grows, the hole mobility decreases providing a tentative explanation for the differences between Cu-oxides and Mn-oxides.Comment: 4 pages with 3 figures embedded in the text, Submitted for publication on August 20, 1996, Minor change
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