355 research outputs found

    Title Wave: The Diffusion of the CEO Title throughout the US Corporate Network

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    http://deepblue.lib.umich.edu/bitstream/2027.42/51340/1/576.pd

    Book Reviews

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    Reviews of the following books: Mount Hope Cemetery of Bangor, Maine: The Complete History by Trudy Irene Scee; The Reverend Jacob Bailey, Maine Loyalist: For God, King, Country and for Self by James S. Leamon; The Barns of Maine: Our History, Our Stories by Don Perkins; Gateway to Vacationland: The Making of Portland, Maine by John F. Bauman; Maine: The Wilder Half of New England by William David Berry; The Cross of War: Christian Nationalism and U.S. Expansion in the Spanish-American War by Matthew McCullough; Omaha Beach: The Life and Military Service of a Penobscot Indian Elder by Charles Norman Shay

    Electrochemical analysis of gold nanoparticles multifunctionalised withCytochrome c and a zinc Porphyrin

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    Cytochrome c (Cyt c), known for its functional redox capabilities, plays a pivotal role in biologicalprocesses such as the electron transport chain and apoptosis. However, understanding how differentconjugation strategies impact its structural and redox characteristics is limited. To fill this gap, weinvestigated the effects of conjugating Cyt c and a zinc(II) porphyrin (Zn Porph) to gold nanoparticles(AuNPs). We used circular dichroism (CD) spectroscopy to detect structural conformational changesin Cyt c upon conjugation and time-of-flight secondary ion mass spectrometry (TOF-SIMS) toidentify protein orientation. Cyt c was predicted to have different orientations depending on the sizeof AuNPs and methods used to conjugate the protein, it was hypothesised that the orientation of Cythttps://doi.org/10.26434/chemrxiv-2023-rsrwv ORCID: https://orcid.org/0000-0002-4872-8928 Content not peer-reviewed by ChemRxiv. License: CC BY 4.02c may influence the redox properties of the protein. The electrochemical properties of Cyt c wereassessed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). We used DPVbasedto determine the heterogeneous rate constant (k0). The results show a lower k0 for conjugatedCyt c than free Cyt c, likely due to structural changes in the protein. The spatial orientation of Cyt chad minimal influence on k0, while ligand density and AuNP size had an effect. The k0 value of ZnPorph did not decrease on conjugation. Despite these changes, Cyt c and Zn Porph maintained theirelectrochemical capabilities after conjugation.</p

    Exact sampling from non-attractive distributions using summary states

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    Propp and Wilson's method of coupling from the past allows one to efficiently generate exact samples from attractive statistical distributions (e.g., the ferromagnetic Ising model). This method may be generalized to non-attractive distributions by the use of summary states, as first described by Huber. Using this method, we present exact samples from a frustrated antiferromagnetic triangular Ising model and the antiferromagnetic q=3 Potts model. We discuss the advantages and limitations of the method of summary states for practical sampling, paying particular attention to the slowing down of the algorithm at low temperature. In particular, we show that such a slowing down can occur in the absence of a physical phase transition.Comment: 5 pages, 6 EPS figures, REVTeX; additional information at http://wol.ra.phy.cam.ac.uk/mackay/exac

    Dynamically Driven Evolution of the Interstellar Medium in M51

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    Massive star formation occurs in giant molecular clouds (GMCs); an understanding of the evolution of GMCs is a prerequisite to develop theories of star formation and galaxy evolution. We report the highest-fidelity observations of the grand-design spiral galaxy M51 in carbon monoxide (CO) emission, revealing the evolution of GMCs vis-a-vis the large-scale galactic structure and dynamics. The most massive GMCs (giant molecular associations (GMAs)) are first assembled and then broken up as the gas flow through the spiral arms. The GMAs and their H_2 molecules are not fully dissociated into atomic gas as predicted in stellar feedback scenarios, but are fragmented into smaller GMCs upon leaving the spiral arms. The remnants of GMAs are detected as the chains of GMCs that emerge from the spiral arms into interarm regions. The kinematic shear within the spiral arms is sufficient to unbind the GMAs against self-gravity. We conclude that the evolution of GMCs is driven by large-scale galactic dynamics—their coagulation into GMAs is due to spiral arm streaming motions upon entering the arms, followed by fragmentation due to shear as they leave the arms on the downstream side. In M51, the majority of the gas remains molecular from arm entry through the interarm region and into the next spiral arm passage

    Impacts of Climate Change on indirect human exposure to pathogens and chemicals from agriculture

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    Objective: Climate change is likely to affect the nature of pathogens and chemicals in the environment and their fate and transport. Future risks of pathogens and chemicals could therefore be very different from those of today. In this review, we assess the implications of climate change for changes in human exposures to pathogens and chemicals in agricultural systems in the United Kingdom and discuss the subsequent effects on health impacts. Data sources: In this review, we used expert input and considered literature on climate change ; health effects resulting from exposure to pathogens and chemicals arising from agriculture ; inputs of chemicals and pathogens to agricultural systems ; and human exposure pathways for pathogens and chemicals in agricultural systems. Data synthesis: We established the current evidence base for health effects of chemicals and pathogens in the agricultural environment ; determined the potential implications of climate change on chemical and pathogen inputs in agricultural systems ; and explored the effects of climate change on environmental transport and fate of different contaminant types. We combined these data to assess the implications of climate change in terms of indirect human exposure to pathogens and chemicals in agricultural systems. We then developed recommendations on future research and policy changes to manage any adverse increases in risks. Conclusions: Overall, climate change is likely to increase human exposures to agricultural contaminants. The magnitude of the increases will be highly dependent on the contaminant type. Risks from many pathogens and particulate and particle-associated contaminants could increase significantly. These increases in exposure can, however, be managed for the most part through targeted research and policy changes

    Dynamically Driven Evolution of the Interstellar Medium in M51

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    We report the highest-fidelity observations of the spiral galaxy M51 in CO emission, revealing the evolution of giant molecular clouds (GMCs) vis-a-vis the large-scale galactic structure and dynamics. The most massive GMCs (so-called GMAs) are first assembled and then broken up as the gas flow through the spiral arms. The GMAs and their H2 molecules are not fully dissociated into atomic gas as predicted in stellar feedback scenarios, but are fragmented into smaller GMCs upon leaving the spiral arms. The remnants of GMAs are detected as the chains of GMCs that emerge from the spiral arms into interarm regions. The kinematic shear within the spiral arms is sufficient to unbind the GMAs against self-gravity. We conclude that the evolution of GMCs is driven by large-scale galactic dynamics --their coagulation into GMAs is due to spiral arm streaming motions upon entering the arms, followed by fragmentation due to shear as they leave the arms on the downstream side. In M51, the majority of the gas remains molecular from arm entry through the inter-arm region and into the next spiral arm passage.Comment: 6 pages, including 3 figures. Accepted, ApJ
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