Developmental changes in the processing of faces as revealed by EEG decoding

Rapidly and accurately processing information from faces is a critical human function that is known to improve with developmental age. Understanding the underlying drivers of this improvement remains a contentious question, with debate continuing as to the presence of early vs. late maturation of face-processing mechanisms. Recent behavioural evidence suggests an important ‘hallmark’ of expert face processing – the face inversion effect – is present in very young children, yet neural support for this remains unclear. To address this, we conducted a detailed investigation of the neural dynamics of face processing in children spanning a range of ages (6 – 11 years) and adults. Uniquely, we applied multivariate pattern analysis (MVPA) to the electroencephalogram signal (EEG) to test for the presence of a distinct neural profile associated with canonical upright faces when compared both to other objects (houses) and to inverted faces. Results revealed robust discrimination profiles, at the individual level, of differentiated neural activity associated with broad face categorization and further with its expert processing, as indexed by the face inversion effect, from the youngest ages tested. This result is consistent with an early functional maturation of broad face processing mechanisms. Yet, clear quantitative differences between the response profile of children and adults is suggestive of age-related refinement of this system with developing face and general expertise. Standard ERP analysis also provides some support for qualitative differences in the neural response to inverted faces in children in contrast to adults. This neural profile is in line with recent behavioural studies that have reported impressively expert early face abilities during childhood, while also providing novel evidence of the ongoing neural specialisation between child and adulthood

Tracing carbon sources of southern Beaufort Sea and Chukchi Sea polar bears using stable isotope analyses

Thesis (M.S.) University of Alaska Fairbanks, 2020The Southern Beaufort Sea (SBS) polar bear (Ursus maritimus) subpopulation has declined in response to sea ice loss, while the Chukchi Sea (CS) subpopulation appears stable. The substantial population decline in the SBS subpopulation in recent years is concurrent with increases in the proportion of polar bears coming on shore, and the duration they spend there. Both of these changes have been associated with the loss of access to their primary sea ice habitat, which is mainly used as a platform to hunt seals. The first objective of this study was to determine if the SBS and CS polar bear subpopulations could be distinguished based on stable isotope signatures (delta¹³C and delta¹⁵N values) of bone collagen. The second objective was to examine patterns in SBS polar bear trophic level and terrestrial carbon sources over a 65-year time period, as polar bears have increasingly used coastal environments. We analyzed 112 SBS and CS polar bear bones (predominantly mandibles) from 1954-2019 that had been archived at the University of Alaska Museum of the North, as well as bones from subsistence-harvested polar bears. In addition to delta¹³C and delta¹⁵N, samples from the SBS bears were analyzed for compound-specific stable carbon isotopes of amino acids (delta¹³CAA values). Another 50 bone collagen samples from terrestrial mammals and pinnipeds from northern Alaska were analyzed for delta¹³CAA values to provide a regional comparative dataset. Our study showed a significant difference in bulk delta¹³C (p<0.001) values, but not delta¹⁵N (p=0.654) values between the CS (-13.0‰±0.3‰ and 22.0‰±0.9‰, respectively) and the SBS bears (-14.7‰±1.3‰ and 22.2‰±1.0‰, respectively). We performed a logistic regression analysis (LR) using bulk delta¹³C and delta¹⁵N values of the polar bears to predict their placement into these two subpopulations. Using Icy Cape, AK as the geographical boundary, LR correctly placed polar bears in their respective subpopulations 82% of the time. Overall accuracy of placement changed to 84% when using the current geographical boundary at Utqiaġvik, AK. Bone collagen has a slow turnover rate, providing long-term, potentially life-long stable isotope signatures. Our findings could be used to determine the association of harvested polar bears to Alaska subpopulations, thus aiding in harvest quota management. The LR predicted samples collected from the Wainwright, AK region to be 58% CS and 42% SBS polar bears. This indicates that the area between Wainwright and Icy Cape is a polar bear mixing zone that includes bears from both subpopulations. Over the 65-year study period, two distinct groups of SBS polar bears were identified based on their delta¹³C values of the amino acid proline: a high delta¹³CPro group (1.8‰±2.3‰, n=45) and a low delta¹³CPro group (-15.7‰±1.9‰, n=26). The high proline polar bear group had delta¹³CPro values similar to those of Arctic brown bears (Ursus arctos; 0.4‰±1.6‰), while the low group had delta¹³CPro values similar to ice seals (-15.3‰±1.2‰). Among the available samples, there were more high proline/pelagic bears (n=17) after the 2007 sea ice minimum than high proline/coastal bears (n=12), which is opposite of what we expected. This study provides evidence that two distinct ecotypes in Southern Beaufort Sea polar bears, pelagic and coastal, have existed since at least the 1950's. Overall, our results represent a detailed isotopic view of the Alaskan polar bear subpopulations, demonstrating the possibility of distinguishing and categorizing individuals as either SBS or CS, while also highlighting the existence of two ecotypes in the SBS subpopulation.Coastal Impact Assistance Program, U.S. Fish and Wildlife Service grant (F12AF01265), U.S. Department of the Interior, North Slope Borough Department of Wildlife Management, MJ Murdock Charitable Trust Grant SR-10 201811010Chapter 1: General Introduction -- Chapter 2: Stable carbon and nitrogen isotope differences of polar bears in the Southern Beaufort Sea and Chukchi Sea -- Chapter 3: Compound-specific stable isotope analyses of amino acids provide evidence of two distinct ecotypes of Southern Beaufort Sea polar bears -- Chapter 4: General Conclusion -- Appendices

Between Here and There: Surveying the Global Work of Diaspora, Migration, and Mobility-Engaged Museums

Diaspora, migration, and mobility-engaged museums are a growing sector amongst global cultural institutions. These museums play a significant role in shaping understandings of migration and representing diaspora identities, cultures, and experiences. Through their work, they also serve an increasingly diplomatic function in fostering mutual understanding amongst various groups and communities. At a time when migration is increasingly contested and politicized, the work of these institutions has never been more pressing. This report presents a global survey of the work of diaspora, migration, and mobility-engaged museums. Our study focused on understanding the sector, including the range and scope of institutions and their approaches, as well as their social and diplomatic impacts. This report shares our findings, which include an assessment of how diaspora and migration are defined in the sector, a typology of museums, their representational strategies, and an analysis of the cultural diplomacy work of these museums. Our research demonstrates the ability of these institutions to unsettle traditional understandings of culture and identity as bounded, singular, and homogenous and to foster narratives that bridge local and global connections

On the Heisenberg invariance and the Elliptic Poisson tensors

We study different algebraic and geometric properties of Heisenberg invariant Poisson polynomial quadratic algebras. We show that these algebras are unimodular. The elliptic Sklyanin-Odesskii-Feigin Poisson algebras $q_{n,k}(\mathcal E)$ are the main important example. We classify all quadratic $H-$invariant Poisson tensors on ${\mathbb C}^n$ with $n\leq 6$ and show that for $n\leq 5$ they coincide with the elliptic Sklyanin-Odesskii-Feigin Poisson algebras or with their certain degenerations.Comment: 14 pages, no figures, minor revision, typos correcte

Braided Matrix Structure of the Sklyanin Algebra and of the Quantum Lorentz Group

Braided groups and braided matrices are novel algebraic structures living in braided or quasitensor categories. As such they are a generalization of super-groups and super-matrices to the case of braid statistics. Here we construct braided group versions of the standard quantum groups $U_q(g)$. They have the same FRT generators $l^\pm$ but a matrix braided-coproduct \und\Delta L=L\und\tens L where $L=l^+Sl^-$, and are self-dual. As an application, the degenerate Sklyanin algebra is shown to be isomorphic to the braided matrices $BM_q(2)$; it is a braided-commutative bialgebra in a braided category. As a second application, we show that the quantum double D(\usl) (also known as the `quantum Lorentz group') is the semidirect product as an algebra of two copies of \usl, and also a semidirect product as a coalgebra if we use braid statistics. We find various results of this type for the doubles of general quantum groups and their semi-classical limits as doubles of the Lie algebras of Poisson Lie groups.Comment: 45 pages. Revised (= much expanded introduction

ICRRA Policy Brief 2022: Culture in Security: International Cultural Relations as an Enabler of Peace through Engagement

How can the arts, heritage and cultural sectors contribute to peace and security in an increasingly conflicted world? At the 2022 ICRRA conference, academic approaches and practical projects from around the world showcased the important role that international cultural relations can play in this. This report shares the overarching message of the conference – about the potential for international cultural relations to re-energise delivery of SDG 16 (peace and justice) and to promote a more holistic understanding of peace and security – along with a summary of reflections from the conference around the key concepts of human security and cultural rights. Case studies and quotes by the participants illustrate these points and exemplify how this cultural relations approach to peace and security works on the ground in different settings

Phase mixing of standing Alfven waves with shear flows in solar spicules

Alfvenic waves are thought to play an important role in coronal heating and solar wind acceleration. Here we investigate the dissipation of such waves due to phase mixing at the presence of shear flow and field in the stratified atmosphere of solar spicules. The initial flow is assumed to be directed along spicule axis and to vary linearly in the x direction and the equilibrium magnetic field is taken 2-dimensional and divergence-free. It is determined that the shear flow and field can fasten the damping of standing Alfven waves. In spite of propagating Alfven waves, standing Alfven waves in Solar spicules dissipate in a few periods. As height increases, the perturbed velocity amplitude does increase in contrast to the behavior of perturbed magnetic field. Moreover, it should be emphasized that the stratification due to gravity, shear flow and field are the facts that should be considered in MHD models in spicules.Comment: Accepted for publication in Astrophysics & Space Scienc

The recent and rapid spread of Themeda triandra

Tropical savannas cover over 20% of land surface. They sustain a high diversity of mammalian herbivores and promote frequent fires, both of which are dependent on the underlying grass composition. These habitats are typically dominated by relatively few taxa, and the evolutionary origins of the dominant grass species are largely unknown. Here, we trace the origins of the genus Themeda, which contains a number of widespread grass species dominating tropical savannas. Complete chloroplast genomes were assembled for seven samples and supplemented with chloroplast and nuclear ITS markers for 71 samples representing 18 of the 27 Themeda species. Phylogenetic analysis supports a South Asian origin for both the genus and the widespread dominant T. triandra. This species emerged ~1.5 Ma from a group that had lived in the savannas of Asia for several million years. It migrated to Australia ~1.3 Ma and to mainland Africa ~0.5 Ma, where it rapidly spread in pre-existing savannas and displaced other species. Themeda quadrivalvis, the second most widespread Themeda species, is nested within T. triandra based on whole chloroplast genomes, and may represent a recent evolution of an annual growth form that is otherwise almost indistinguishable from T. triandra. The recent spread and modern-day dominance of T. triandra highlight the dynamism of tropical grassy biomes over millennial time-scales that has not been appreciated, with dramatic shifts in species dominance in recent evolutionary times. The ensuing species replacements likely had profound effects on fire and herbivore regimes across tropical savannas

Summary of the effects of three tillage and three traffic systems on cereal yields over a four-year rotation

This paper reports the design and results of a study to consider the effects of deep, shallow and zero tillage with random conventional and low tyre inflation pressures and controlled traffic systems on the yield of winter wheat, winter barley (×2) and spring oats. The results show that crop yields for zero tillage were significantly less (P<0.001) than deep and shallow tillage for all crops with an overall reduction of 1.0 t ha-1 below the mean of the deep and shallow tillage practices. Controlled traffic farming with a 30% trafficked area produced significantly higher yields than random conventional pressure traffic for the winter wheat and spring oats. Controlled traffic farming, with trafficked areas of 30% and 15% showed overall benefits over random conventional inflation pressure traffic of 0.32 t ha-1 (£41 ha-1) and 0.61 t ha-1 (£77 ha-1) respectively, requiring breakeven areas of 312 ha and 168 ha to cover the costs of three vehicle guidance/auto-steering systems