336 research outputs found

    Masterly Confusion: Ported Protection in the American Interwar

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    In domestic design projects ranging from carpet prototypes for the Metropolitan Museum in New York to bridge infrastructures for Robert Moses, architects Ralph Walker and Aymar Embury II drew from their experiences of trauma, play, and tectonic improvisation as camoufleurs during the First World War to work through logics of protective concealment. As with the operations of artillery and personnel camouflage, where makeshift flat tops of fabric and foliage provided portable spaces of relief within a brutal theater of reciprocal violence, the 'masterly confusion' of much interwar architectural work long deemed 'modernistic', middlebrow, or not fully modern was often animated by therapeutic desires for safety and comfort. Here, designs which sought to mask or avoid the aesthetic and physiological shocks of modernity also furthered the entrenchment of modern forms of mobilization, organization, and risk management. This essay traces how formal ambivalence born out of protective necessity on the battlefields of the First World War migrated across surfaces and mutated into surfaces back in the United States, advancing fluid forms of capital and corporatism via subtle tectonic and material means across a range of scales. It also argues that descriptive difficulty with respect to interwar style (and its relation to 'modernity') starts to dissolve when switching registers to look at the attitudes that pervade these architectural practices of conscious equivocation. This work marks a critical episode in modern architecture's construction of an expanded notion of environment, where engagement was produced through and experienced as relief

    Mechanisms of ligand-receptor interactions of the dopamine D2L receptor and their relation to functional selectivity

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    Binding and functional studies indicate that some agonists are capable of differentially activating pathways linked to a single receptor isoform. In cases where known mechanisms like other receptors or receptor reserve are ruled out, this phenomenon is referred to as “functional selectivity,” “agonist directed trafficking,” and a variety of other terms. Rather than viewing receptors in a traditional way as digital entities (i.e., one or more active or inactive states), functional selectivity posits that a receptor can be induced into unique conformations that may lead to different patterns of activation of functional responses linked to a single receptor. This dissertation elucidates the molecular mechanisms that explain why some ligands can differentially activate the effector pathways coupled to the human D2L receptor. The focus will be to discern the structural interactions of the hD2L receptor with such functionally selective ligands, and how these interactions result in selective activation of effector pathways. Computationally-selected point mutations of the D2L receptor were made, and detailed analysis of both binding and function made for a series of rationally selected ligands, emphasizing compounds that were relatively rigid and had fewer degrees of freedom in possible docking poses. Functional assays tested the intrinsic activity and potency for GTPγS binding, inhibition of forskolin-stimulated cAMP, phosphorylation of MAPK, and release of [3H]-arachidonic acid. Results from this dissertation provide evidence to support the hypothesis that ligand-selective interactions with specific residues of the receptor can induce conformational changes that lead to a characteristic pattern of activation of one of more signaling pathways. Developing a structure-based understanding of functional selectivity will provide general insight into the mechanisms of GPCR activation, and may also open the door to design of small molecules with desired patterns of functional effects at a single receptor

    CO2-plume geothermal: Power net generation from 3D fluvial aquifers

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    Previously CO2, as a heat-extraction fluid, has been proposed as a superior substitute for brine in geothermal energy extraction. Hence, the new concept of CO2-plume geothermal (CPG) is suggested to generate heat from geothermal aquifers using CO2 as the working fluid. In January 2015, a CPG-thermosiphon system commenced at the SECARB Cranfield Site, Mississippi. By utilising CO2, the demand for the pumping power is greatly reduced due to the thermosiphon effect at the production well. However, there are still parameters such as aquifer thermal depletion, required high injection rates, and CO2-plume establishment time, that hinder CPG from becoming viable. Moreover, the fluvial nature of sedimentary aquifers significantly affects the heat and mass transfer inside the aquifer, as well as the system performance. In the present study, a direct-CO2 thermosiphon system is considered that produces electricity from a 3D braided-fluvial sedimentary aquifer by providing an excess pressure at the surface that is used in the turbine. The system performance and net power output are analyzed in 15 3D fluvial heterogeneous - with channels’ widths of 50, 100, and 150 m - and three homogeneous aquifer realizations with different CO2 injection rates. It is observed that the presence of fluvial channels significantly increases the aquifer thermal depletion pace (22-120%) and therefore, reduces the system’s performance up to about 75%. Additionally, it is found that the CPG system with the CO2 injection rate of 50 kg/s and the I-P line parallel to the channels provides the maximum cycle operation time (44 years), as well as the optimum performance for the heterogeneous cases of the present study by providing about 0.06-0.12 TWh energy during the simulation time of 50 years. Also, to prevent rapid drops in excess pressure, a system with a yearly adjustable injection rate is implemented, which prevents the production well bottomhole temperature to fall below 80 ◦C

    Real time x-ray studies during nanostructure formation on silicon via low energy ion beam irradiation using ultrathin iron films

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    Real time grazing incidence small angle x-ray scattering and x-ray fluorescence (XRF) are used to elucidate nanodot formation on silicon surfaces during low energy ion beam irradiation of ultrathin iron-coated silicon substrates. Four surface modification stages were identified: (1) surface roughening due to film erosion, (2) surface smoothing and silicon-iron mixing, (3) structure formation, and (4) structure smoothing. The results conclude that 2.5 x 10(15) iron atoms in a 50 nm depth triggers surface nanopatterning with a correlated nanodots distance of 25 nm. Moreover, there is a wide window in time where the surface can have correlated nanostructures even after the removal of all the iron atoms from the sample as confirmed by XRF and ex-situ x-ray photoelectron spectroscopy (XPS). In addition, in-situ XPS results indicated silicide formation, which plays a role in the structure formation mechanism. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773202

    Size Matters: Microservices Research and Applications

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    In this chapter we offer an overview of microservices providing the introductory information that a reader should know before continuing reading this book. We introduce the idea of microservices and we discuss some of the current research challenges and real-life software applications where the microservice paradigm play a key role. We have identified a set of areas where both researcher and developer can propose new ideas and technical solutions.Comment: arXiv admin note: text overlap with arXiv:1706.0735

    Age-related changes in eye lens biomechanics, morphology, refractive index and transparency

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    Life-long eye lens function requires an appropriate gradient refractive index, biomechanical integrity and transparency. We conducted an extensive study of wild-type mouse lenses 1-30 months of age to define common age-related changes. Biomechanical testing and morphometrics revealed an increase in lens volume and stiffness with age. Lens capsule thickness and peripheral fiber cell widths increased between 2 to 4 months of age but not further, and thus, cannot account for significant age-dependent increases in lens stiffness after 4 months. In lenses from mice older than 12 months, we routinely observed cataracts due to changes in cell structure, with anterior cataracts due to incomplete suture closure and a cortical ring cataract corresponding to a zone of compaction in cortical lens fiber cells. Refractive index measurements showed a rapid growth in peak refractive index between 1 to 6 months of age, and the area of highest refractive index is correlated with increases in lens nucleus size with age. These data provide a comprehensive overview of age-related changes in murine lenses, including lens size, stiffness, nuclear fraction, refractive index, transparency, capsule thickness and cell structure. Our results suggest similarities between murine and primate lenses and provide a baseline for future lens aging studies

    Candidate gene polymorphisms study between human African trypanosomiasis clinical phenotypes in Guinea

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    Human African trypanosomiasis (HAT), a lethal disease induced by Trypanosoma brucei gambiense, has a range of clinical outcomes in its human host in West Africa: an acute form progressing rapidly to second stage, spontaneous self-cure and individuals able to regulate parasitaemia at very low levels, have all been reported from endemic foci. In order to test if this clinical diversity is influenced by host genetic determinants, the association between candidate gene polymorphisms and HAT outcome was investigated in populations from HAT active foci in Guinea.Samples were collected from 425 individuals; comprising of 232 HAT cases, 79 subjects with long lasting positive and specific serology but negative parasitology and 114 endemic controls. Genotypes of 28 SNPs in eight genes passed quality control and were used for an association analysis. IL6 rs1818879 allele A (p = 0.0001, OR = 0.39, CI95 = [0.24-0.63], BONF = 0.0034) was associated with a lower risk of progressing from latent infection to active disease. MIF rs36086171 allele G seemed to be associated with an increased risk (p = 0.0239, OR = 1.65, CI95 = [1.07-2.53], BONF = 0.6697) but did not remain significant after Bonferroni correction. Similarly MIF rs12483859 C allele seems be associated with latent infections (p = 0.0077, OR = 1.86, CI95 = [1.18-2.95], BONF = 0.2157). We confirmed earlier observations that APOL1 G2 allele (DEL) (p = 0.0011, OR = 2.70, CI95 = [1.49-4.91], BONF = 0.0301) is associated with a higher risk and APOL1 G1 polymorphism (p = 0.0005, OR = 0.45, CI95 = [0.29-0.70], BONF = 0.0129) with a lower risk of developing HAT. No associations were found with other candidate genes.Our data show that host genes are involved in modulating Trypanosoma brucei gambiense infection outcome in infected individuals from Guinea with IL6 rs1818879 being associated with a lower risk of progressing to active HAT. These results enhance our understanding of host-parasite interactions and, ultimately, may lead to the development of new control tools
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