705 research outputs found

    A study of morphology, provenance, and movement of desert sand seas in Africa, Asia, and Australia

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    A description and classification of major types of sand seas on the basis of morphological pattern and lineation are discussed. The steps involved in analyzing the patterns of deposits on ERTS-1 imagery, where the visible forms are mostly dune complexes rather than individual dunes are outlined. After completion of thematic maps portraying the pattern and lineation of the sand bodies, data on directions and intensity of prevailing and other winds are plotted on corresponding bases, as a preliminary to determination of internal structures through ground truth

    A synthesis of sand seas throughout the world

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    There are no author-identified significant results in this report

    'No-One Can Tell a Story Better than the One Who Lived It': Reworking Constructions of Childhood and Trauma Through the Arts in Rwanda

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    The intergenerational legacies of conflict and violence for children and young people are typically approached within research and interventions through the lens of trauma. Understandings of childhood and trauma are based on bio-psychological frameworks emanating from the Global North, often at odds with the historical, political, economic, social and cultural contexts in which interventions are enacted, and neglect the diversity of knowledge, experiences and practices. Within this paper we explore these concerns in the context of Rwanda and the aftermath of the 1994 Genocide Against the Tutsi. We reflect on two qualitative case studies: Connective Memories and Mobile Arts for Peace which both used arts-based approaches drawing on the richness of Rwandan cultural forms, such as proverbs and storytelling practices, to explore knowledge and processes of meaning-making about trauma, memory, and everyday forms of conflict from the perspectives of children and young people. We draw on these findings to argue that there is a need to refine and elaborate understandings of intergenerational transmission of trauma in Rwanda informed by: the historical and cultural context; intersections of structural and ‘everyday’ forms of conflict and social trauma embedded in intergenerational relations; and a reworking of notions of trauma ‘transmission’ to encompass the multiple connectivities between generations, temporalities and expressions of trauma

    CD8αα intestinal intraepithelial lymphocytes derived from two thymic precursors seed the intestine in early life

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    TCRαβ CD4 CD8αα intestinal intraepithelial lymphocytes (CD8αα IEL) descend from thymic precursors. To better define this IEL precursor (IELp) population, we analyzed their maturation, localization, and emigration. Using rigorous lineage exclusion criteria, we defined two precursors among DN TCRβ thymocytes: a nascent PD-1 population and a T-bet population that accumulates with age. Both gave rise to intestinal CD8αα IEL upon adoptive transfer. In adult mice, PD-1 cells contained more self-reactive clones, localized to the cortex, and were dominant in S1PR1-dependent thymic egress. Gut homing α4β7 was already expressed by these IELp at a thymic stage. To understand the kinetics of CD8αα IEL seeding the intestine, we performed "timestamp" experiments: We crossed Cd4 with Rosa26 (stop-floxed tdTomato) mice. In these mice, tamoxifen or its metabolite 4-OHT permanently labels every CD4 expressing cell. As TCRαβ T cells (including CD8αα IEL) go through a CD4 CD8 stage during thymic development, a single dose of tamoxifen or 4-OHT will label thymic IEL precursors permanently, so that they can be tracked when seeding the gut. Our results indicate that these cells enter the intestine during a narrow time window in early life and that this influx is almost completely shut down by the age of 3 weeks. These data provide an important foundation for understanding the biology of this abundant population of barrier surface T cells

    Increasing the Quantity of Silver in Zinc-Based Glass Polyalkenoate Cement: is There an Improvement in Antibacterial Efficacy?

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    Bone cements should have the ability to chemically bond to both bone and surgical metals, exhibit no chemical or thermal necrosis, and have no significant shrinkage or exotherm upon setting. Taking these properties into consideration, glass polyalkenoate cements (GPCs) have potential as bone cements. GPCs are formed by the reaction between an ion-leachable glass and an aqueous solution of polyacrylic acid (PAA) [1] and have proven antibacterial and cariostatic properties [2], which are related to their ability to release beneficial amounts of ions over time [3, 4]. The GPCs can be formulated to release ions that can have a therapeutic benefit in a chosen application such as fluoride release in dental applications [5], which assists in the prevention of secondary caries [6]. Recently, GPCs have been formulated with zinc (Zn) replacing Al; a more biologically acceptable ion [7]. The authors have previously shown that GPCs based on a glass phase containing both Zn and silver (Ag) have the ability to release ions which are antibacterial against both Staphylococcus aureus (Oxford strain) [8] and Pseudomonas aeruginosa (a clinical isolate) [9, 10] in vitro and methicillin-resistant S. aureus (MRSA) both in vitro and in vivo [11]. The authors have also shown that their cements have the ability to inhibit proliferation of a biofilm of P. aeruginosa (PA01) [9]. The objective of the study reported herein is to build on the authors previous publications in order to determine if increases in Ag content of the glass phase of these cements will result in a concomitant increase in antibacterial efficacy of the resultant Ag-Zn GPCs formulated from them. © 2012 IEEE

    Classical Correlation-Length Exponent in Non-Universal Quantum Phase Transition of Diluted Heisenberg Antiferromagnet

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    Critical behavior of the quantum phase transition of a site-diluted Heisenberg antiferromagnet on a square lattice is investigated by means of the quantum Monte Carlo simulation with the continuous-imaginary-time loop algorithm. Although the staggered spin correlation function decays in a power law with the exponent definitely depending on the spin size SS, the correlation-length exponent is classical, i.e., ν=4/3\nu=4/3. This implies that the length scale characterizing the non-universal quantum phase transition is nothing but the mean size of connected spin clusters.Comment: 4 pages, 3 figure

    Choreography, controversy and child sex abuse: Theoretical reflections on a cultural criminological analysis of dance in a pop music video

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    This article was inspired by the controversy over claims of ‘pedophilia!!!!’ undertones and the ‘triggering’ of memories of childhood sexual abuse in some viewers by the dance performance featured in the music video for Sia’s ‘Elastic Heart’ (2015). The case is presented for acknowledging the hidden and/or overlooked presence of dance in social scientific theory and cultural studies and how these can enhance and advance cultural criminological research. Examples of how these insights have been used within other disciplinary frameworks to analyse and address child sex crime and sexual trauma are provided, and the argument is made that popular cultural texts such as dance in pop music videos should be regarded as significant in analysing and tracing public perceptions and epistemologies of crimes such as child sex abuse

    KRAS-specific inhibition using a DARPin binding to a site in the allosteric lobe.

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    Inhibiting the RAS oncogenic protein has largely been through targeting the switch regions that interact with signalling effector proteins. Here, we report designed ankyrin repeat proteins (DARPins) macromolecules that specifically inhibit the KRAS isoform by binding to an allosteric site encompassing the region around KRAS-specific residue histidine 95 at the helix α3/loop 7/helix α4 interface. We show that these DARPins specifically inhibit KRAS/effector interactions and the dependent downstream signalling pathways in cancer cells. Binding by the DARPins at that region influences KRAS/effector interactions in different ways, including KRAS nucleotide exchange and inhibiting KRAS dimerization at the plasma membrane. These results highlight the importance of targeting the α3/loop 7/α4 interface, a previously untargeted site in RAS, for specifically inhibiting KRAS function

    Evaluation of ELISA and haemagglutination inhibition as screening tests in serosurveillance for H5/H7 avian influenza in commercial chicken flocks

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    Avian influenza virus (AIV) subtypes H5 and H7 can infect poultry causing low pathogenicity (LP) AI, but these LPAIVs may mutate to highly pathogenic AIV in chickens or turkeys causing high mortality, hence H5/H7 subtypes demand statutory intervention. Serological surveillance in the European Union provides evidence of H5/H7 AIV exposure in apparently healthy poultry. To identify the most sensitive screening method as the first step in an algorithm to provide evidence of H5/H7 AIV infection, the standard approach of H5/H7 antibody testing by haemagglutination inhibition (HI) was compared with an ELISA, which detects antibodies to all subtypes. Sera (n = 1055) from 74 commercial chicken flocks were tested by both methods. A Bayesian approach served to estimate diagnostic test sensitivities and specificities, without assuming any 'gold standard'. Sensitivity and specificity of the ELISA was 97% and 99.8%, and for H5/H7 HI 43% and 99.8%, respectively, although H5/H7 HI sensitivity varied considerably between infected flocks. ELISA therefore provides superior sensitivity for the screening of chicken flocks as part of an algorithm, which subsequently utilises H5/H7 HI to identify infection by these two subtypes. With the calculated sensitivity and specificity, testing nine sera per flock is sufficient to detect a flock seroprevalence of 30% with 95% probability

    Transfer of environmental microbes to the skin and respiratory tract of humans after urban green space exposure

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    Available online 22 September 2020BACKGROUND: In industrialized countries, non-communicable diseases have been increasing in prevalence since the middle of the 20th century. While the causal mechanisms remain poorly understood, increased population density, pollution, sedentary behavior, smoking, changes in diet, and limited outdoor exposure have all been proposed as significant contributors. Several hypotheses (e.g. Hygiene, Old Friends, and Biodiversity Hypotheses) also suggest that limited environmental microbial exposures may underpin part of this rise in non-communicable diseases. In response, the Microbiome Rewilding Hypothesis proposes that adequate environmental microbial exposures could be achieved by restoring urban green spaces and could potentially decrease the prevalence of non-communicable diseases. However, the microbial interactions between humans and their surrounding environment and the passaging of microbes between both entities remains poorly understood, especially within an urban context. RESULTS: Here, we survey human skin (n = 90 swabs) and nasal (n = 90 swabs) microbiota of three subjects that were exposed to air (n = 15), soil (n = 15), and leaves (n = 15) from different urban green space environments in three different cities across different continents (Adelaide, Australia; Bournemouth, United Kingdom; New Delhi, India). Using 16S ribosomal RNA metabarcoding, we examined baseline controls (pre-exposure) of both skin (n = 16) and nasal (n = 16) swabs and tracked microbiota transfer from the environment to the human body after exposure events. Microbial richness and phylogenetic diversity increased after urban green space exposure in skin and nasal samples collected in two of the three locations. The microbial composition of skin samples also became more similar to soil microbiota after exposure, while nasal samples became more similar to air samples. Nasal samples were more variable between sites and individuals than skin samples. CONCLUSIONS: We show that exposure to urban green spaces can increase skin and nasal microbial diversity and alter human microbiota composition. Our study improves our understanding of human-environmental microbial interactions and suggests that increased exposure to diverse outdoor environments may increase the microbial diversity, which could lead to positive health outcomes for non-communicable diseases.Caitlin A. Selway, Jacob G. Mills, Philip Weinstein, Chris Skelly, Sudesh Yadav, Andrew Lowe, Martin F. Breed, Laura S. Weyric
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