1,228 research outputs found

    No Justice, No Peace: An Examination of the Conditions of the George Floyd Protests to Determine How to Facilitate Successful State Legislative Outcomes

    Get PDF
    This thesis examines the relationship between the conditions of the George Floyd protests from May to August of 2020 to the impact they had state on policing reforms within state legislatures. I examine protests in all 50 states and the District of Columbia, looking at those protests’ size, media coverage, and violence and compare that to the degree of policy change achieved within each state. I find that, contrary to expectations, protest size was not associated with policy change, but that the party control of the state government was a strong predictor of how states responded to protests. Within some state subgroups, the presence of violence and media coverage of violence had a statistically significant effect in shaping policy change. These findings help us understand what conditions are needed to create a successful protest

    Molecular Basis of C–N Bond Cleavage by the Glycyl Radical Enzyme Choline Trimethylamine-Lyase

    Get PDF
    Deamination of choline catalyzed by the glycyl radical enzyme choline trimethylamine-lyase (CutC) has emerged as an important route for the production of trimethylamine, a microbial metabolite associated with both human disease and biological methane production. Here, we have determined five high-resolution X-ray structures of wild-type CutC and mechanistically informative mutants in the presence of choline. Within an unexpectedly polar active site, CutC orients choline through hydrogen bonding with a putative general base, and through close interactions between phenolic and carboxylate oxygen atoms of the protein scaffold and the polarized methyl groups of the trimethylammonium moiety. These structural data, along with biochemical analysis of active site mutants, support a mechanism that involves direct elimination of trimethylamine. This work broadens our understanding of radical-based enzyme catalysis and will aid in the rational design of inhibitors of bacterial trimethylamine production.National Science Foundation (U.S.) (Grant 0645960

    Synthesis, stereocontrol and structural studies of highly luminescent chiral tris-amidepyridyl-triazacyclononane lanthanide complexes

    Get PDF
    The configuration of the remote amide chiral moiety determines the helicity of the metal complex in Ln(III) complexes of nonadentate N6O3 ligands based on triazacyclononane. Solution NMR studies revealed the presence of a dominant isomer whose proportion varies from 9 : 1 to 4 : 1 from Ce to Yb and X-ray crystallographic studies at 120 K of the Yb and two enantiomeric Eu complexes confirmed the configuration as S-Δ-λ in the major isomer. Global minimisation methods allowed magnetic susceptibility and electronic relaxation times of the lanthanide ions to be estimated by analysis of variable field longitudinal relaxation rate (R1) data sets. A set of four europium complexes, containing different para-substituted pyridinyl-aryl groups, exist as one major isomer (15 : 1), and absorb light strongly via an ICT transition in the range 320 to 355 nm (Δ = 55 to 65 000 M−1 cm−1). The two examples absorbing light at 332 nm, possess overall emission quantum yields of 35 and 37% in aerated water, making these systems as bright as any Eu complex in solution

    Tickling the TLR7 to cure viral hepatitis

    Full text link

    Synthesis and Catalytic Activity of (3,4-Diphenylcyclopentadienone)Iron Tricarbonyl Compounds in Transfer Hydrogenations and Dehydrogenations

    Full text link
    Four (3,4-diphenylcyclopentadienone)iron tricarbonyl compounds were synthesized, and their activities in transfer hydrogenations of carbonyl compounds and transfer dehydrogenations of alcohols were explored and compared to those of the well-established [2,5-(SiMe3)2-3,4-(CH2)4(η4-C4C═O)]Fe(CO)3 (3). A new compound, [2,5-bis(3,5-dimethylphenyl)-3,4-diphenylcyclopentadienone]iron tricarbonyl (7), was the most active catalyst in both transfer hydrogenations and dehydrogenations, and compound 3 was the least active catalyst in transfer hydrogenations. Evidence was found for product inhibition of both 3 and 7 in a transfer dehydrogenation reaction, with the activity of 3 being more heavily affected. A monomeric iron hydride derived from 7 was spectroscopically observed during a transfer hydrogenation, and no diiron bridging hydrides were found under reductive or oxidative conditions. Initial results in the transfer hydrogenation of N-benzylideneaniline showed that 3 was a significantly less active catalyst in comparison to the (3,4-diphenylcyclopentadienone)iron tricarbonyl compounds

    Avifauna discard packages and bone damage resulting from human consumption processes

    Get PDF
    Few actualistic studies of the patterns resulting from human preparation and consumption of birds inform interpretations of archeological avifauna assemblages. This study focuses on developing new and adding to existing interpretive models. We examine differences in bone modifications produced by a culturally homogeneous group of eaters consuming medium-sized birds cooked using three cross-culturally common methods. We use the analytical concept of discard packages to capture variability in how groups of skeletal elements might be deposited into the archeological record. We also examine chop/cut marks, burn marks, and chew marks as these are variables that archeologists frequently use to identify and interpret anthropogenic avifaunal assemblages. We find that the creation of discard packages appears to be culturally motivated and varies little within our group of eaters, but the degree to which the associated elements are disaggregated during consumption is highly variable and depends on individual preference. Additionally, we find that while the presence and locations of chop marks are consistent across cooking methods and individual consumption preferences, the presence and locations of cut marks, burn marks, and chew marks are affected by cooking methods, individual preferences, or both

    (Cyclopentadienone)iron-Catalyzed Transfer Dehydrogenation of Symmetrical and Unsymmetrical Diols to Lactones

    Full text link
    Air-stable iron carbonyl compounds bearing cyclopentadienone ligands with varying substitution were explored as catalysts in dehydrogenative diol lactonization reactions using acetone as both the solvent and hydrogen acceptor. Two catalysts with trimethylsilyl groups in the 2- and 5-positions, [2,5-(SiMe3)2-3,4-(CH2)4(η4-C4C═O)]Fe(CO)3 (1) and [2,5-(SiMe3)2-3,4-(CH2)3(η4-C4C═O)]Fe(CO)3 (2), were found to be the most active, with 2 being the most selective in the lactonization of diols containing both primary and secondary alcohols. Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no over-oxidations to carboxylic acids were detected. The lactonization of unsymmetrical diols containing two primary alcohols occurred with catalyst 1, but selectivity was low based on alcohol electronics and modest based on alcohol sterics. Evidence for a transfer dehydrogenation mechanism was found, and insight into the origin of selectivity in the lactonization of 1°/2° diols was obtained. Additionally, spectroscopic evidence for a trimethylamine-ligated iron species formed in solution during the reaction was discovered

    Routine childhood immunisation during the COVID-19 pandemic in Africa: a benefit-risk analysis of health benefits versus excess risk of SARS-CoV-2 infection.

    Get PDF
    BACKGROUND: National immunisation programmes globally are at risk of suspension due to the severe health system constraints and physical distancing measures in place to mitigate the ongoing COVID-19 pandemic. We aimed to compare the health benefits of sustaining routine childhood immunisation in Africa with the risk of acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through visiting routine vaccination service delivery points. METHODS: We considered a high-impact scenario and a low-impact scenario to approximate the child deaths that could be caused by immunisation coverage reductions during COVID-19 outbreaks. In the high-impact scenario, we used previously reported country-specific child mortality impact estimates of childhood immunisation for diphtheria, tetanus, pertussis, hepatitis B, Haemophilus influenzae type b, Streptococcus pneumoniae, rotavirus, measles, meningitis A, rubella, and yellow fever to approximate the future deaths averted before 5 years of age by routine childhood vaccination during a 6-month COVID-19 risk period without catch-up campaigns. In the low-impact scenario, we approximated the health benefits of sustaining routine childhood immunisation on only the child deaths averted from measles outbreaks during the COVID-19 risk period. We assumed that contact-reducing interventions flattened the outbreak curve during the COVID-19 risk period, that 60% of the population will have been infected by the end of that period, that children can be infected by either vaccinators or during transport, and that upon child infection the whole household will be infected. Country-specific household age structure estimates and age-dependent infection-fatality rates were applied to calculate the number of deaths attributable to the vaccination clinic visits. We present benefit-risk ratios for routine childhood immunisation, with 95% uncertainty intervals (UIs) from a probabilistic sensitivity analysis. FINDINGS: In the high-impact scenario, for every one excess COVID-19 death attributable to SARS-CoV-2 infections acquired during routine vaccination clinic visits, 84 (95% UI 14-267) deaths in children could be prevented by sustaining routine childhood immunisation in Africa. The benefit-risk ratio for the vaccinated children is 85 000 (4900-546 000), for their siblings (60 years) is 96 (14-307). In the low-impact scenario that approximates the health benefits to only the child deaths averted from measles outbreaks, the benefit-risk ratio to the households of vaccinated children is 3 (0-10); if the risk to only the vaccinated children is considered, the benefit-risk ratio is 3000 (182-21 000). INTERPRETATION: The deaths prevented by sustaining routine childhood immunisation in Africa outweigh the excess risk of COVID-19 deaths associated with vaccination clinic visits, especially for the vaccinated children. Routine childhood immunisation should be sustained in Africa as much as possible, while considering other factors such as logistical constraints, staff shortages, and reallocation of resources during the COVID-19 pandemic. FUNDING: Gavi, the Vaccine Alliance; Bill & Melinda Gates Foundation
    • 

    corecore