4,291 research outputs found

    Reciprocal anatomical relationship between primary sensory and prefrontal cortices in the human brain

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    The human brain exhibits remarkable interindividual variability in cortical architecture. Despite extensive evidence for the behavioral consequences of such anatomical variability in individual cortical regions, it is unclear whether and how different cortical regions covary in morphology. Using a novel approach that combined noninvasive cortical functional mapping with whole-brain voxel-based morphometric analyses, we investigated the anatomical relationship between the functionally mapped visual cortices and other cortical structures in healthy humans. We found a striking anticorrelation between the gray matter volume of primary visual cortex and that of anterior prefrontal cortex, independent from individual differences in overall brain volume. Notably, this negative correlation formed along anatomically separate pathways, as the dorsal and ventral parts of primary visual cortex showed focal anticorrelation with the dorsolateral and ventromedial parts of anterior prefrontal cortex, respectively. Moreover, a similar inverse correlation was found between primary auditory cortex and anterior prefrontal cortex, but no anatomical relationship was observed between other visual cortices and anterior prefrontal cortex. Together, these findings indicate that an anatomical trade-off exists between primary sensory cortices and anterior prefrontal cortex as a possible general principle of human cortical organization. This new discovery challenges the traditional view that the sizes of different brain areas simply scale with overall brain size and suggests the existence of shared genetic or developmental factors that contributes to the formation of anatomically and functionally distant cortical regions

    Enhancing Resilience in Classrooms

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    Schools have historically been the great equalizer in American communities—the “ticket out” for youth struggling to overcome adversity and pov­erty (Pianta & Walsh, 1998). For children who immigrated to the United States at the turn of the twentieth century schools were safe havens where they learned English received public health services and became literate and employable (Fagan, 2000; Goldstein, 2014). As each wave of homesteaders moved west across the country schools popped up alongside the newly broken sod. Universal access to public education is a defining feature of the North American society and schools are fertile settings for promoting youth’s intellectual psychological and personal competence (Luthar & Eisenberg, 2017; Masten, 2014) The purpose of this chapter is to reframe this American dream around contemporary research and conceptual frameworks of resilience, and to show how these frameworks can be foundations for classroom level interventions that contribute to students’ psychological wellness and strengthen their competence. The chapter uses Masten and Coatsworth’s (1998) simple defini­tion of resilience: “Resilience is how children overcome adversity to achieve good developmen­tal outcomes” (p. 205). Within this definition, our own sons and daughters would not be considered “resilient” although they are successful adults, because they did not struggle with significant adversity in their first three decades of life. Alternatively, in many schools where we have worked, substantial numbers of children came to school hungry, frightened, with inadequate cloth­ing, or with shocking memories of family or community violence and abuse. Resilience describes the conditions that allow these children to succeed nevertheless

    A fiber optic spectrometry system for measuring irradiance distributions in sea ice environments

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    Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 31 (2014): 2844–2857, doi:10.1175/JTECH-D-14-00108.1.A fiber optic–based spectrometry system was developed to enable automated, long-term measurements of spectral irradiance in sea ice environments. This system utilizes a single spectrometer module that measures the irradiance transmitted by multiple optical fibers, each coupled to the input fiber of the module via a mechanical rotary multiplexer. Small custom-printed optical diffusers, fixed to the input end of each fiber, allow these probes to be frozen into ice auger holes as small as 5 cm in diameter. Temperature-dependent biases in the spectrometer module and associated electronics were examined down to −40°C using an environmental chamber to identify any artifacts that might arise when operating these electronic and optical components below their vendor-defined lower temperature limits. The optical performance of the entire system was assessed by freezing multiple fiber probes in a 1.2-m-tall ice column, illuminating from above with a light source, and measuring spectral irradiance distributions at different depths within the ice column. Results indicated that the radiometric sensitivity of this fiber-based system is comparable to that of commercially available oceanographic spectroradiometers.This research was supported by the Joint Initiative Awards Fund from the Andrew W. Mellon Foundation, through Woods Hole Oceanographic Institution’s internal Interdisciplinary Study Award program (S. R. L. and T. M.), and by a China scholarship council (CSC) scholarship and the Program for Zhejiang Leading Team of S&T Innovation (Grant 2010R50036) provided to H. W.2015-06-0

    Contextual Illusions Reveal the Limit of Unconscious Visual Processing

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    The perception of even the most elementary features of the visual environment depends strongly on their spatial context. In the study reported here, we asked at what level of abstraction such effects require conscious processing of the context. We compared two visual illusions that alter subjective judgments of brightness: the simultaneous brightness contrast illusion, in which two circles of identical physical brightness appear different because of different surround luminance, and the Kanizsa triangle illusion, which occurs when the visual system extrapolates a surface without actual physical stimulation. We used a novel interocular masking technique that allowed us to selectively render only the context invisible. Simultaneous brightness contrast persisted even when the surround was masked from awareness. In contrast, participants did not experience illusory contours when the inducing context was masked. Our findings show that invisible context is resolvable by low-level processes involved in surface-brightness perception, but not by high-level processes that assign surface borders through perceptual completion

    Hadron

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    Pg 4 : The Impact of a Sip of Coffee Pg 8 : Any Ideas About Sonoluminesence? Pg 11 : Memory, Memory, and the Brain Pg 13 : Climate Change Soon to Be a Thing of the Past? Pg 15 : Non Fungible Tokenshttps://digitalcommons.imsa.edu/hadron_magazine/1007/thumbnail.jp

    Crossover from weakly indirect to direct excitons in atomically thin films of InSe

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    We perform a kp\mathbf{k \cdot p} theory analysis of the spectra of the lowest energy and excited states of the excitons in few-layer atomically thin films of InSe taking into account in-plane electric polarizability of the film and the influence of the encapsulation environment. For the thinner films, the lowest-energy state of the exciton is weakly indirect in momentum space, with its dispersion showing minima at a layer-number-dependent wave number, due to an inverted edge of a relatively flat topmost valence band branch of the InSe film spectrum and we compute the activation energy from the momentum dark exciton ground state into the bright state. For the films with more than seven In2_2Se2_2 layers, the exciton dispersion minimum shifts to Γ\Gamma-point.Comment: 12 pages, 7 figure

    A High-Resolution Map of Arabidopsis Recombinant Inbred Lines by Whole-Genome Exon Array Hybridization

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    Recombinant populations were the basis for Mendel's first genetic experiments and continue to be key to the study of genes, heredity, and genetic variation today. Genotyping several hundred thousand loci in a single assay by hybridizing genomic DNA to oligonucleotide arrays provides a powerful technique to improve precision linkage mapping. The genotypes of two accessions of Arabidopsis were compared by using a 400,000 feature exon-specific oligonucleotide array. Around 16,000 single feature polymorphisms (SFPs) were detected in ~8,000 of the ~26,000 genes represented on the array. Allelic variation at these loci was measured in a recombinant inbred line population, which defined the location of 815 recombination breakpoints. The genetic linkage map had a total length of 422.5 cM, with 676 informative SFP markers representing intervals of ~0.6 cM. One hundred fifteen single gene intervals were identified. Recombination rate, SFP distribution, and segregation in this population are not uniform. Many genomic regions show a clustering of recombination events including significant hot spots. The precise haplotype structure of the recombinant population was defined with unprecedented accuracy and resolution. The resulting linkage map allows further refinement of the hundreds of quantitative trait loci identified in this well-studied population. Highly variable recombination rates along each chromosome and extensive segregation distortion were observed in the population
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