"On the Spot": travelling artists and Abolitionism, 1770-1830

Until recently the visual culture of Atlantic slavery has rarely been critically scrutinised. Yet in the first decades of the nineteenth century slavery was frequently represented by European travelling artists, often in the most graphic, sometimes voyeuristic, detail. This paper examines the work of several itinerant artists, in particular Augustus Earle (1793-1838) and Agostino Brunias (1730–1796), whose very mobility along the edges of empire was part of a much larger circulatory system of exchange (people, goods and ideas) and diplomacy that characterised Europe’s Age of Expansion. It focuses on the role of the travelling artist, and visual culture more generally, in the development of British abolitionism between 1770 and 1830. It discusses the broad circulation of slave imagery within European culture and argues for greater recognition of the role of such imagery in the abolitionist debates that divided Britain. Furthermore, it suggests that the epistemological authority conferred on the travelling artist—the quintessential eyewitness—was key to the rhetorical power of his (rarely her) images. Artists such as Earle viewed the New World as a boundless source of fresh material that could potentially propel them to fame and fortune. Johann Moritz Rugendas (1802-1858), on the other hand, was conscious of contributing to a global scientific mission, a Humboldtian imperative that by the 1820s propelled him and others to travel beyond the traditional itinerary of the Grand Tour. Some artists were implicated in the very fabric of slavery itself, particularly those in the British West Indies such as William Clark (working 1820s) and Richard Bridgens (1785-1846); others, particularly those in Brazil, expressed strong abolitionist sentiments. Fuelled by evangelical zeal to record all aspects of the New World, these artists recognised the importance of representing the harsh realities of slave life. Unlike those in the metropole who depicted slavery (most often in caustic satirical drawings), many travelling artists believed strongly in the evidential value of their images, a value attributed to their global mobility. The paper examines the varied and complex means by which visual culture played a significant and often overlooked role in the political struggles that beset the period

Efficient Photocatalytic Water Reduction Using In Situ Generated Knölker's Iron Complexes

Inâ situ generated ironâ based Knölker complexes were found to be efficient catalysts in a fully nonâ noble metal Cuâ Fe photocatalytic water reduction system. These mononuclear iron catalysts were able to generate hydrogen up to 15 times faster than previously reported [Fe3(CO)12]. A reductive quenching mechanism was shown to operate by fluorescence experiments.Photo finish: Inâ situ generated ironâ based Knölker complexes are efficient catalysts in a fully nonâ noble metal Cuâ Fe photocatalytic water reduction system. These mononuclear iron catalysts generate hydrogen up to 15 times faster than previously reported [Fe3(CO)12]. A reductive quenching mechanism is shown to operate by fluorescence experiments. CuPS=copper(I) photosensitizer; SR=sacrificial reductant.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137356/1/cctc201600186.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137356/2/cctc201600186_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137356/3/cctc201600186-sup-0001-misc_information.pd

Vesicular Stomatitis Virus-Based Ebola Vaccine Is Well-Tolerated and Protects Immunocompromised Nonhuman Primates

Ebola virus (EBOV) is a significant human pathogen that presents a public health concern as an emerging/re-emerging virus and as a potential biological weapon. Substantial progress has been made over the last decade in developing candidate preventive vaccines that can protect nonhuman primates against EBOV. Among these prospects, a vaccine based on recombinant vesicular stomatitis virus (VSV) is particularly robust, as it can also confer protection when administered as a postexposure treatment. A concern that has been raised regarding the replication-competent VSV vectors that express EBOV glycoproteins is how these vectors would be tolerated by individuals with altered or compromised immune systems such as patients infected with HIV. This is especially important as all EBOV outbreaks to date have occurred in areas of Central and Western Africa with high HIV incidence rates in the population. In order to address this concern, we evaluated the safety of the recombinant VSV vector expressing the Zaire ebolavirus glycoprotein (VSVΔG/ZEBOVGP) in six rhesus macaques infected with simian-human immunodeficiency virus (SHIV). All six animals showed no evidence of illness associated with the VSVΔG/ZEBOVGP vaccine, suggesting that this vaccine may be safe in immunocompromised populations. While one goal of the study was to evaluate the safety of the candidate vaccine platform, it was also of interest to determine if altered immune status would affect vaccine efficacy. The vaccine protected 4 of 6 SHIV-infected macaques from death following ZEBOV challenge. Evaluation of CD4+ T cells in all animals showed that the animals that succumbed to lethal ZEBOV challenge had the lowest CD4+ counts, suggesting that CD4+ T cells may play a role in mediating protection against ZEBOV

Unravelling The Mechanism of Basic Aqueous Methanol Dehydrogenation Catalyzed By Ru-PNP Pincer Complexes

Ruthenium PNP complex <b>1a</b> (RuH­(CO)­Cl­(HN­(C₂H₄P<i>i</i>-Pr₂)₂)) represents a state-of-the-art catalyst for low-temperature (<100 °C) aqueous methanol dehydrogenation to H₂ and CO₂. Herein, we describe an investigation that combines experiment, spectroscopy, and theory to provide a mechanistic rationale for this process. During catalysis, the presence of two anionic resting states was revealed, Ru–dihydride (<b>3</b>^<b>–</b>) and Ru–monohydride (<b>4</b>^<b>–</b>) that are deprotonated at nitrogen in the pincer ligand backbone. DFT calculations showed that O- and C<u>H</u>- coordination modes of methoxide to ruthenium compete, and form complexes <b>4</b>^<b>–</b> and <b>3</b>^<b>–</b>, respectively. Not only does the reaction rate increase with increasing KOH, but the ratio of <b>3</b>^<b>–</b>/<b>4</b>^<b>–</b> increases, demonstrating that the “inner-sphere” CH cleavage, via C<u>H</u> coordination of methoxide to Ru, is promoted by base. Protonation of <b>3</b>^<b>–</b> liberates H₂ gas and formaldehyde, the latter of which is rapidly consumed by KOH to give the corresponding gem-diolate and provides the overall driving force for the reaction. Full MeOH reforming is achieved through the corresponding steps that start from the gem-diolate and formate. Theoretical studies into the mechanism of the catalyst <b>Me-1a</b> (<i>N</i>-methylated <b>1a</b>) revealed that CH coordination to Ru sets-up CH cleavage and hydride delivery; a process that is also promoted by base, as observed experimentally. However, in this case, Ru–dihydride <b>Me-3</b> is much more stable to protonation and can even be observed under neutral conditions. The greater stability of <b>Me-3</b> rationalizes the lower rates of <b>Me-1a</b> compared to <b>1a</b>, and also explains why the reaction rate then drops with increasing KOH concentration

Solar Hydrogen Production by Plasmonic Au–TiO₂ Catalysts: Impact of Synthesis Protocol and TiO₂ Phase on Charge Transfer Efficiency and H₂ Evolution Rates

The activity of plasmonic Au–TiO₂ catalysts for solar hydrogen production from H₂O/MeOH mixtures was found to depend strongly on the support phase (anatase, rutile, brookite, or composites thereof) as well as on specific structural properties caused by the method of Au deposition (sol-immobilization, photodeposition, or deposition–precipitation). Structural and electronic rationale have been identified for this behavior. Using a combination of spectroscopic in situ techniques (EPR, XANES, and UV–vis spectroscopy), the formation of plasmonic Au particles from precursor species was monitored, and the charge-carrier separation and stabilization under photocatalytic conditions was explored in relation to H₂ evolution rates. By in situ EPR spectroscopy, it was directly shown that abundant surface vacancies and surface OH groups enhance the stabilization of separated electrons and holes, whereas the enrichment of Ti³⁺ in the support lattice hampers an efficient electron transport. Under the given experimental conditions, these properties were most efficiently generated by depositing gold particles on anatase/rutile composites using the deposition–precipitation technique

Mechanisms of Resistance to Prostate-Specific Membrane Antigen-Targeted Radioligand Therapy in a Mouse Model of Prostate Cancer

Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) is effective against prostate cancer (PCa), but all patients relapse eventually. Poor understanding of the underlying resistance mechanisms represents a key barrier to development of more effective RLT. We investigate the proteome and phosphoproteome in a mouse model of PCa to identify signaling adaptations triggered by PSMA RLT. Methods: Therapeutic efficacy of PSMA RLT was assessed by tumor volume measurements, time to progression, and survival in C4-2 or C4-2 TP53-/- tumor-bearing nonobese diabetic scid γ-mice. Two days after RLT, the proteome and phosphoproteome were analyzed by mass spectrometry. Results: PSMA RLT significantly improved disease control in a dose-dependent manner. Proteome and phosphoproteome datasets revealed activation of genotoxic stress response pathways, including deregulation of DNA damage/replication stress response, TP53, androgen receptor, phosphatidylinositol-3-kinase/AKT, and MYC signaling. C4-2 TP53-/- tumors were less sensitive to PSMA RLT than were parental counterparts, supporting a role for TP53 in mediating RLT responsiveness. Conclusion: We identified signaling alterations that may mediate resistance to PSMA RLT in a PCa mouse model. Our data enable the development of rational synergistic RLT-combination therapies to improve outcomes for PCa patients