235 research outputs found
Unveiling the Sketching Society (1799-1851)
In 1799, a group of young London-based artists founded a new Sketching Society. It was still in existence some fifty years or so later. Up until now, the Society has principally been of interest to scholars only insomuch as the names of Thomas Girtin and John Sell Cotman can be attached to its earliest activities and meetings. However, this has been to the neglect of the far better documented and longer-lived iteration of the group that was overseen by the brothers Alfred Edward Chalon and John James Chalon. This thesis will therefore look to re-assess the development of the Sketching Society, paying particular attention to its later, currently under-appreciated history under the Chalons in order to explore the place and wider importance of such affiliations in the art world of the early nineteenth century. This will mean looking at continuities in the aims and organisation of the Society over time, but also how the changing priorities of the increasingly better connected and established members of the Chalon-led group distinguish it from that pool of artists who first met around the turn of the century.
Beginning with a brief history of the clubs associated with Girtin and Cotman, the thesis will then go on to examine the make-up of the Chalon group. Subsequent chapters discuss the actual activities of this later group, exploring the literary or thematic prompts employed at their regular evening meetings and reconstructing select sessions. They will then consider the public-facing aspects of the Societyâs life, in the form of a series of publications and exhibitions it organised to promote its activities. All told, a survey of what might be termed the long history of the Sketching Society is revealing of the significance of such collaborative and communal activities in making and sustaining a career in the capitalâs art world
Perturbed cholesterol and vesicular trafficking associated with dengue blocking in Wolbachia-infected Aedes aegypti cells
Wolbachia are intracellular maternally inherited bacteria that can spread through insect populations and block virus transmission by mosquitoes, providing an important approach to dengue control. To better understand the mechanisms of virus inhibition, we here perform proteomic quantification of the effects of Wolbachia in Aedes aegypti mosquito cells and midgut. Perturbations are observed in vesicular trafficking, lipid metabolism and in the endoplasmic reticulum that could impact viral entry and replication. Wolbachia-infected cells display a differential cholesterol profile, including elevated levels of esterified cholesterol, that is consistent with perturbed intracellular cholesterol trafficking. Cyclodextrins have been shown to reverse lipid accumulation defects in cells with disrupted cholesterol homeostasis. Treatment of Wolbachia-infected Ae. aegypti cells with 2-hydroxypropyl-ÎČ-cyclodextrin restores dengue replication in Wolbachia-carrying cells, suggesting dengue is inhibited in Wolbachia-infected cells by localised cholesterol accumulation. These results demonstrate parallels between the cellular Wolbachia viral inhibition phenotype and lipid storage genetic disorders
Total Synthesis of the Bovine Pancreatic Trypsin Inhibitor (BPTI) and the Protein Diastereomer [Gly37D-Ala]BPTI using Boc Chemistry Solid Phase Peptide Synthesis
Bovine pancreatic trypsin inhibitor (BPTI) is a wellâstudied model for investigation of protein folding and stability. Here, we report the synthesis and characterization of wildâtype BPTI and a diastereomeric protein analogue [Gly37DâAla]BPTI. Each 58âresidue polypeptide chain was made by native chemical ligation of two peptide segments, BPTI[1â29]âαthioester and the appropriate version of the Cys30â58 BPTI peptide segment. Boc chemistry in situ neutralization solid phase synthesis was used to prepare the peptide segment reactants. The resulting fullâlength polypeptide chains were folded in a cysteine/cystine redox buffer to give synthetic protein molecules containing three disulfide bonds. The diastereomeric analogue [Gly37DâAla]BPTI folded as efficiently as the native protein. Synthetic proteins were characterized by analytical LCMS and by naturalâabundance 1Hâ15N HSQC NMR fingerprinting. These results illustrate the power of Boc chemistry peptide synthesis and its utility for the total chemical synthesis of protein molecules
Morphology of the ferritin iron core by aberration corrected scanning transmission electron microscopy
As the major iron storage protein, ferritin stores and releases iron for maintaining the balance of iron in fauna, flora, and bacteria. We present an investigation of the morphology and iron loading of ferritin (from equine spleen) using aberration-corrected high angle annular dark field scanning transmission electron microscopy. Atom counting method, with size selected Au clusters as mass standards, was employed to determine the number of iron atoms in the nanoparticle core of each ferritin protein. Quantitative analysis shows that the nuclearity of iron atoms in the mineral core varies from a few hundred iron atoms to around 5000 atoms. Moreover, a relationship between the iron loading and iron core morphology is established, in which mineral core nucleates from a single nanoparticle, then grows along the protein shell before finally forming either a solid or hollow core structure
Ultraconserved element (UCE) probe set design: Base genome and initial design parameters critical for optimization
This work is licensed under a Creative Commons Attribution 4.0 International License.Targeted capture and enrichment approaches have proven effective for phylogenetic study. Ultraconserved elements (UCEs) in particular have exhibited great utility for phylogenomic analyses, with the software package phyluce being among the most utilized pipelines for UCE phylogenomics, including probe design. Despite the success of UCEs, it is becoming increasing apparent that diverse lineages require probe sets tailored to focal taxa in order to improve locus recovery. However, factors affecting probe design and methods for optimizing probe sets to focal taxa remain underexplored. Here, we use newly available beetle (Coleoptera) genomic resources to investigate factors affecting UCE probe set design using phyluce. In particular, we explore the effects of stringency during initial design steps, as well as base genome choice on resulting probe sets and locus recovery. We found that both base genome choice and initial bait design stringency parameters greatly alter the number of resultant probes included in final probe sets and strongly affect the number of loci detected and recovered during in silico testing of these probe sets. In addition, we identify attributes of base genomes that correlated with high performance in probe design. Ultimately, we provide a recommended workflow for using Phyluce to design an optimized UCE probe set that will work across a targeted lineage, and use our findings to develop a new, openâsource UCE probe set for beetles of the suborder Adephaga.NIH IRACDA postdoctoral fellowship (5K12GM063651)Harold E. and Leona M. Rice Endowment Fund at Oregon State Universit
Helicoidal instability of a scroll vortex in three-dimensional reaction-diffusion systems
We study the dynamics of scroll vortices in excitable reaction-diffusion
systems analytically and numerically. We demonstrate that intrinsic
three-dimensional instability of a straight scroll leads to the formation of
helicoidal structures. This behavior originates from the competition between
the scroll curvature and unstable core dynamics. We show that the obtained
instability persists even beyond the meander core instability of
two-dimensional spiral wave.Comment: 4 pages, 5 figures, revte
Lives before and after Stonehenge: An osteobiographical study of four prehistoric burials recently excavated from the Stonehenge World Heritage Site
Osteobiographies of four individuals whose skeletal remains were recovered in 2015â16 from the Stonehenge World Heritage Site are constructed, drawing upon evidence from funerary taphonomy, radiocarbon dating, osteological study, stable isotope analyses, and microscopic and biomolecular analyses of dental calculus. The burials comprise an adult from the Middle Neolithic period, immediately prior to the building of Stonehenge, and two adults and a perinatal infant dating from the Middle Bronze Age, shortly after the monument ceased to be structurally modified. The two Middle Bronze Age adults were closely contemporary, but differed from one another in ancestry, appearance and geographic origin (key components of ethnicity). They were nevertheless buried in very similar ways. This suggests that aspects they held in common (osteological analysis suggests perhaps a highly mobile lifestyle) were more important in determining the manner of deposition of their bodies than any differences between them in ethnicity. One of these individuals probably came from outside Britain, as perhaps did the Middle Neolithic adult. This would be consistent with the idea that the Stonehenge landscape had begun to draw people to it from beyond Britain before Stonehenge was constructed and that it continued to do so after structural modification to the monument had ceased
Scroll waves in isotropic excitable media : linear instabilities, bifurcations and restabilized states
Scroll waves are three-dimensional analogs of spiral waves. The linear
stability spectrum of untwisted and twisted scroll waves is computed for a
two-variable reaction-diffusion model of an excitable medium. Different bands
of modes are seen to be unstable in different regions of parameter space. The
corresponding bifurcations and bifurcated states are characterized by
performing direct numerical simulations. In addition, computations of the
adjoint linear stability operator eigenmodes are also performed and serve to
obtain a number of matrix elements characterizing the long-wavelength
deformations of scroll waves.Comment: 30 pages 16 figures, submitted to Phys. Rev.
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