210 research outputs found

    Archaeological Survey and Assessment of the Proposed Eno River and Little Lick Creek Force Main Routes, Durham County, North Carolina

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    Technical Report No. 20, Research Laboratories of Archaeology, University of North Carolina at Chapel Hill. Reports in this series present the findings of archaeological surveys and test excavations completed by the RLA between 1983 and present

    An Abbreviated NAGPRA Inventory of the North Carolina Archaeological Collection

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    The Research Laboratories of Archaeology's inventory of human skeletal remains and associated and unassociated funerary objects from Native American sites in the North Carolina Archaeological Collection at the University of North Carolina at Chapel Hill

    Electrochemical Investigation of Azurin Thermodynamic and Adsorption Properties at Monolayer-Protected Cluster Film Assemblies – Evidence for a More Homogeneous Adsorption Interface

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    Thermodynamic and adsorption properties of protein monolayer electrochemistry (PME) are examined for Pseudomonas aeruginosa azurin (AZ) immobilized at an electrode modified with a networked film of monolayer-protected clusters (MPCs) to assess if nanoparticle films of this nature offer a more homogeneous adsorption interface compared to traditional self-assembled monolayer (SAM) modified electrodes. Specifically, electrochemistry is used to assess properties of surface coverage, formal potential, peak broadening, and electron transfer (ET) kinetics as a function of film thickness. The modification of a surface with dithiol-linked films of MPCs (Au225C675) provides a more uniform binding interface for AZ that results in voltammetry with less peak broadening (mV) compared to SAMs (\u3e120–130 mV). Improved homogeneity of the MPC interface for protein adsorption is confirmed by atomic force microscopy imaging that shows uniform coverage of the gold substrate topography and by electrochemical analysis of film properties during systematic desorption of AZ, which indicates a more homogeneous population of adsorbed protein at MPC films. These results suggest MPC film assemblies may be used in PME to provide greater molecular level control of the protein adsorption interface, a development with applications for strategies to study biological ET processes as well as the advancement of biosensor technologies

    Distance Dependence of Electron Transfer Kinetics for Azurin Protein Adsorbed to Monolayer Protected Nanoparticle Film Assemblies

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    The distance dependence and kinetics of the heterogeneous electron transfer (ET) reaction for the redox protein azurin adsorbed to an electrode modified with a gold nanoparticle film are investigated using cyclic voltammetry. The nanoparticle films are comprised of nonaqueous nanoparticles, known as monolayer-protected clusters (MPCs), which are covalently networked with dithiol linkers. The MPC film assembly serves as an alternative adsorption platform to the traditional alkanethiolate self-assembled monolayer (SAM) modified electrodes that are commonly employed to study the ET kinetics of immobilized redox proteins, a strategy known as protein monolayer electrochemistry. Voltammetric analysis of the ET kinetics for azurin adsorbed to SAMs of increasing chain length results in quasi-reversible voltammetry with significant peak splitting. We observed rate constants (k°ET) of 12−20 s−1 for the protein at SAMs of shorter alkanethiolates that decays exponentially (ÎČ = 0.9/CH2 or 0.8/Å) at SAMs of longer alkanethiolates (9−11 methylene units) or an estimated distance of 1.23 nm and is representative of classical electronic tunneling behavior over increasing distance. Azurin adsorbed to the MPC film platforms of increasing thickness results in reversible voltammetry with very little voltammetric peaks splitting and nearly negligible decay of the ET rate over significant distances up to 20 nm. The apparent lack of distance dependence for heterogeneous ET reactions at MPC film assemblies is attributed to a two-step mechanism involving extremely fast electronic hopping through the MPC film architecture. These results suggest that MPC platforms may be used in protein monolayer electrochemistry to create adsorption platforms of higher architecture that can accommodate greater than monolayer protein coverage and increase the Faradaic signal, a finding with significant implications for amperometric biosensor design and development

    Encounters with the moral economy of water: convergent evolution in Valencia

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    [EN] This article presents the results of comparative fieldwork on the huerta of Valencia in Spain, a successful community-managed irrigation system of medium scale, one governed collectively by thousands of small farmers organized into 10 autonomous but highly interdependent irrigator groups. The study tested a model identified previously in research on successful systems of much smaller scale in Peru, a set of principles of operation that, when affirmed by farmers and obeyed as collective-choice rules, interact to create equity among water rights and transparency in water use in an unusual way. The authors show that a nearly identical set are at work in all 10 communities of Valencia, revealing the unique manner in which these work together to promote successful and sustainable cooperation, both within and between the user groups, and arguing that their presence in Spain and the Andes is indicative, not of diffusion from one continent to another, but of independent invention. These principles together laid the foundations for separate Andean and Islamic hydraulic traditions, which were often manifested locally in robust and equitable systems of the same general type, here called the moral economy of water. This kind of communal system appears to have emerged repeatedly, and often independently, in a great many other locales and settings throughout the world; its adaptive dynamics are shown to be of great relevance to small farmers today as they face the growing scarcity of water being induced by population growth and by climate change.Trawick, P.; Ortega Reig, MV.; Palau-Salvador, G. (2014). Encounters with the moral economy of water: convergent evolution in Valencia. Wiley Interdisciplinary Reviews: Water. 1(1):87-110. doi:10.1002/wat2.1008S871101

    Breadwinners and Homemakers: Migration and Changing Conjugal Expectations in Rural Bangladesh

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    The literature on marriage norms and aspirations across societies largely sees the institution as static – a tool for the assertion of masculinities and subordination of women. The changing meanings of marriage and conjugality in the contemporary context of globalisation have received scant attention. Based on research in rural Bangladesh, this article questions the usefulness of notions of autonomy and dependence in understanding conjugal relations and expectations in a context of widespread migration for extended periods, especially to overseas destinations, where mutuality is crucial for social reproduction, though in clearly genderdemarcated domains

    An unusual cause of granulomatous disease

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    BACKGROUND: Chronic granulomatous disease (CGD) is an inherited disorder of phagocytic cells caused by an inability to generate active microbicidal oxygen species required kill certain types of fungi and bacteria. This leads to recurrent life-threatening bacterial and fungal infections with tissue granuloma formation. CASE PRESENTATION: We describe a case of X-linked Chronic granulomatous disease (CGD) diagnosed in an 18-year-old male. He initially presented with granulomatous disease mimicking sarcoidosis and was treated with corticosteroids. He subsequently developed Burkholderia cepacia complex pneumonia and further investigation confirmed a diagnosis of CGD. CONCLUSION: Milder phenotypes of CGD are now being recognised. CGD should be considered in patients of any age with granulomatous diseases, especially if there is a history of recurrent or atypical infection

    Differentiated legitimacy, differentiated resilience: beyond the natural in ‘natural disasters’

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    This paper starts with a flood in southern Malawi. Although apparently a ‘natural’ event, those most affected argued that it was made much worse by the rehabilitation of a nearby irrigation scheme. We use this example to interrogate the current interest in resilience from a perspective informed by political ecology and political economy, arguing that a focus on resilience should not be at the expense of understanding the conditions that shape vulnerability, including the ways in which ‘communities’ are differentiated. Complex factors are at play – and the ways in which these combine can result in a ‘perfect storm’ for some individuals and households. These factors include the effects of history combining with ethnicity, of legitimacy influencing voice, and of the interplay of political dynamics at different levels. In particular, processes of commodification have played an important role in shaping how some may benefit at the cost of catastrophic harm to others

    Proton irradiation of CVD diamond detectors for high-luminosity experiments at the LHC

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    CVD diamond shows promising properties for use as a position sensitive detector for experiments in the highest radiation areas at the Large Hadron Collider. In order to study the radiation hardn ess of diamond we exposed CVD diamond detector samples to 24~GeV/cc and 500~MeV protons up to a fluence of 5×1015 p/cm25\times 10^{15}~p/{\rm cm^2}. We measured the charge collection distance, the ave rage distance electron hole pairs move apart in an external electric field, and leakage currents before, during, and after irradiation. The charge collection distance remains unchanged up to 1 times1015 p/cm21\ times 10^{15}~p/{\rm cm^2} and decreases by ≈\approx40~\% at 5×1015 p/cm25\times 10^{15}~p/{\rm cm^2}. Leakage currents of diamond samples were below 1~pA before and after irradiation. The particle indu ced currents during irradiation correlate well with the proton flux. In contrast to diamond, a silicon diode, which was irradiated for comparison, shows the known large increase in leakage curren t. We conclude that CVD diamond detectors are radiation hard to 24~GeV/cc and 500~MeV protons up to at least 1×1015 p/cm21\times 10^{15}~p/{\rm cm^2} without signal loss
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