1,231 research outputs found

    The Barbarians of Hollywood : The Exploitation of Aurora Mardiganian by the American Film Industry

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    As the first genocide of the 20th century tore through Ottoman Turkey, advances within the film industry opened new doors for humanitarian aid. The story of Aurora Mardiganian, a teenage Armenian survivor, provided Americans with a visual representation of what mass atrocity looked like through the film Ravished Armenia. However, the means to which the film and accompanying autobiography were created exemplify a violation of ethics. Anthony Slideā€™s edited edition of the narrative titled Ravished Armenia and the Story of Aurora Mardiganian offers an insightful account of Mardiganianā€™s plight, and gives evidence to the claim that she was exploited physically, psychologically, and financially, in order to yield the maximum profit. Mardiganianā€™s legacy highlights the need for remembrance over apathy, and active awareness over indifference

    QUANTUM KEY DISTRIBUTION LABORATORY DEMONSTRATION

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    Quantum key distribution (QKD) is a method of secure key distribution which provides protection against the tampering and interception of information. Following the Bennet-Brassard 1984 (BB84) protocol of QKD, we select randomly from a set of bases in which to produce polarized photons and send the photons to a receiver, who measures them in a basis randomly selected from the same set. The fact that quantum mechanics prohibits the exact copying of a photon ensures that any eavesdropper who intercepts, measures, and attempts to pass the photons on to the receiver will be unable to faithfully reproduce that signal. The presence of the eavesdropper can then be detected, prior to any exchange of information, by an examination of the error rate between portions of the keys generated by the sender and receiver. Using a biphoton source, we have constructed a QKD system for use in research towards naval applications.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

    Lifetimes, transition probabilities, and level energies in Fe I

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    We use time-resolved laser-induced fluorescence to measure the lifetime of 186 Fe levels with energies between 25 900 and 60 758 cm . Measured emission branching fractions for these levels yield transition probabilities for 1174 transitions in the range 225-2666 nm. We find another 640 Fe transition probabilities by interpolating level populations in the inductively coupled plasma spectral source. We demonstrate the reliability of the interpolation method by comparing our transition probabilities with absorption oscillator strengths measured by the Oxford group [Blackwell et al., Mon. Not. R. Astron. Soc. 201, 595-602 (1982)]. We derive precise Fe level energies to support the automated method that is used to identify transitions in our spectra

    Impact of Tumor-Derived CCL2 on Macrophage Effector Function

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    Monocyte chemoattractant protein-1 (MCP-1, CCL2) is produced by many different types of cells. In the current investigation, the effect of tumor-derived CCL2 on macrophages was evaluated to determine the extent to which this chemokine influenced the innate immune response to cancer. To do this, we used the 4T1 murine mammary carcinoma cell line that constitutively expresses CCL2 and generated 4T1 expressing an antisense CCL2 transcript. The antisense-CCL2-expressing 4T1 produced no detectable CCL2. Macrophages from female BALB/c mice were exposed to supernatants from these tumor cells. The results showed that tumor-derived CCL2 was capable of modulating cytokine gene expression but not protein production in resting, activated, and tumor-associated macrophages. In addition, tumor-derived CCL2 did not affect phagocytic activity, nitric oxide production, or cytolytic activity of the macrophages. Overall, these data suggest that tumor-derived CCL2 does not directly influence macrophage-mediated antitumor activity

    Weak line water vapor spectrum in the 13 200ā€“15 000 cmāˆ’1 region

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    New Fourier transform spectra of water vapor are presented in the range 6500ā€“16 400 cmāˆ’1 obtained using pathlengths of up to 800 m and long integration times. These spectra have a significantly higher signal-to-noise than previous measurements in this wavenumber range. Wavenumbers, absolute intensities and self-broadening coefficients, all with associated uncertainties, are presented for 3604 lines in the region 13 200ā€“15 000 cmāˆ’1. Analysis of these lines using variational linelists, along with other unassigned lines from previous studies, has been conducted. This leads to 952 new line assignments to transitions involving 35 different vibrational states of H216O. A smaller number of lines are assigned to H218O and H217O

    Searching for overturning convection in penumbral filaments: slit spectroscopy at 0.2 arcsec resolution

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    Recent numerical simulations of sunspots suggest that overturning convection is responsible for the existence of penumbral filaments and the Evershed flow, but there is little observational evidence of this process. Here we carry out a spectroscopic search for small-scale convective motions in the penumbra of a sunspot located 5 deg away from the disk center. The position of the spot is very favorable for the detection of overturning downflows at the edges of penumbral filaments. Our analysis is based on measurements of the Fe I 709.0 nm line taken with the Littrow spectrograph of the Swedish 1 m Solar Telescope under excellent seeing conditions. We compute line bisectors at different intensity levels and derive Doppler velocities from them. The velocities are calibrated using a nearby telluric line, with systematic errors smaller than 150 m/s. Deep in the photosphere, as sampled by the bisectors at the 80%-88% intensity levels, we always observe blueshifts or zero velocities. The maximum blueshifts reach 1.2 km/s and tend to be cospatial with bright penumbral filaments. In the line core we detect blueshifts for the most part, with small velocities not exceeding 300 m/s. Redshifts also occur, but at the level of 100-150 m/s, and only occasionally. The fact that they are visible in high layers casts doubts on their convective origin. Overall, we do not find indications of downflows that could be associated with overturning convection at our detection limit of 150 m/s. Either no downflows exist, or we have been unable to observe them because they occur beneath tau=1 or the spatial resolution/height resolution of the measurements is still insufficient.Comment: Accepted for publication in Ap

    Class II ADP-ribosylation factors are required for efficient secretion of Dengue viruses

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    This article is available open access through the publisherā€™s website.Identification and characterization of virus-host interactions are very important steps toward a better understanding of the molecular mechanisms responsible for disease progression and pathogenesis. To date, very few cellular factors involved in the life cycle of flaviviruses, which are important human pathogens, have been described. In this study, we demonstrate a crucial role for class II Arf proteins (Arf4 and Arf5) in the dengue flavivirus life cycle. We show that simultaneous depletion of Arf4 and Arf5 blocks recombinant subviral particle secretion for all four dengue serotypes. Immunostaining analysis suggests that class II Arf proteins are required at an early pre-Golgi step for dengue virus secretion. Using a horseradish peroxidase protein fused to a signal peptide, we show that class II Arfs act specifically on dengue virus secretion without altering the secretion of proteins through the constitutive secretory pathway. Co-immunoprecipitation data demonstrate that the dengue prM glycoprotein interacts with class II Arf proteins but not through its C-terminal VXPX motif. Finally, experiments performed with replication-competent dengue and yellow fever viruses demonstrate that the depletion of class II Arfs inhibits virus secretion, thus confirming their implication in the virus life cycle, although data obtained with West Nile virus pointed out the differences in virus-host interactions among flaviviruses. Our findings shed new light on a molecular mechanism used by dengue viruses during the late stages of the life cycle and demonstrate a novel function for class II Arf proteins.Research Fund for Control of Infectious Diseases of Hong Kong and BNP Paribas Corporate and Investment Banking

    Answering Conjunctive Queries under Updates

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    We consider the task of enumerating and counting answers to kk-ary conjunctive queries against relational databases that may be updated by inserting or deleting tuples. We exhibit a new notion of q-hierarchical conjunctive queries and show that these can be maintained efficiently in the following sense. During a linear time preprocessing phase, we can build a data structure that enables constant delay enumeration of the query results; and when the database is updated, we can update the data structure and restart the enumeration phase within constant time. For the special case of self-join free conjunctive queries we obtain a dichotomy: if a query is not q-hierarchical, then query enumeration with sublinearāˆ—^\ast delay and sublinear update time (and arbitrary preprocessing time) is impossible. For answering Boolean conjunctive queries and for the more general problem of counting the number of solutions of k-ary queries we obtain complete dichotomies: if the query's homomorphic core is q-hierarchical, then size of the the query result can be computed in linear time and maintained with constant update time. Otherwise, the size of the query result cannot be maintained with sublinear update time. All our lower bounds rely on the OMv-conjecture, a conjecture on the hardness of online matrix-vector multiplication that has recently emerged in the field of fine-grained complexity to characterise the hardness of dynamic problems. The lower bound for the counting problem additionally relies on the orthogonal vectors conjecture, which in turn is implied by the strong exponential time hypothesis. āˆ—)^\ast) By sublinear we mean O(n1āˆ’Īµ)O(n^{1-\varepsilon}) for some Īµ>0\varepsilon>0, where nn is the size of the active domain of the current database

    Weak line water vapor spectrum in the 11,787ā€“13,554 cmāˆ’1 region

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    Long-pathlength Fourier transform spectra of water vapor recorded previously by Schermaul et al. (J. Mole. Spectrosc. 211, 169 (2002)) are analyzed in the range 11 787ā€“13 554 cmāˆ’1. Wavenumbers, absolute intensities, and self-broadening coefficients, with associated uncertainties, are presented for 2137 lines. Analysis of these lines using variational linelists has been conducted leading to the assignment of 1906 of the new lines to 23 different upper vibrational states in the 3Ī½+Ī“, 4Ī½, and 4Ī½+Ī“ polyads, a further 19 lines are ascribed to H218O. Comparisons are made with the HITRAN database
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