354 research outputs found

    Albert Camus\u27s meditative ascent: a search for foundations in The Plague

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    Albert Camus\u27s concept of absurdity states that human existence is fundamentally chaotic and meaningless. Despite this appraisal of existence, Camus tirelessly campaigned for human rights at a time when many intellectuals ignored the atrocities perpetrated by ideological compatriots. Scholars admire Camus\u27s courage and foresight, but few have attempted to systematically examine Camus\u27s philosophical development of values. Eric Voegelin argues that Camus\u27s writings take the form of a philosophical meditation in which Camus conducted an analysis of existence through the medium of fictional creation. This meditation, which Voegelin likens to a Platonic periagoge, allowed Camus to establish a foundation of values that remained consistent with the logic of the absurd and fostered an appreciation of present reality. This study examines Camus\u27s mediation by emphasizing the components that are present in his novel The Plague. Camus ultimately arrives at an aesthetic theory in which he equates beauty with the common dignity of mankind

    Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles

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    Background: There is renewed interest in the development of poxvirus vector-based HIV vaccines due to the protective effect observed with repeated recombinant canarypox priming with gp120 boosting in the recent Thai placebo-controlled trial. This study sought to investigate whether a heterologous prime-boost-boost vaccine regimen in Chinese cynomolgus macaques with a DNA vaccine and recombinant poxviral vectors expressing HIV virus-like particles bearing envelopes derived from the most prevalent clades circulating in sub-Saharan Africa, focused the antibody response to shared neutralising epitopes. Methods: Three Chinese cynomolgus macaques were immunised via intramuscular injections using a regimen composed of a prime with two DNA vaccines expressing clade A Env/clade B Gag followed by boosting with recombinant fowlpox virus expressing HIV-1 clade D Gag, Env and cholera toxin B subunit followed by the final boost with recombinant modified vaccinia virus Ankara expressing HIV-1 clade C Env, Gag and human complement protein C3d. We measured the macaque serum antibody responses by ELISA, enumerated T cell responses by IFN-gamma ELISpot and assessed seroneutralisation of HIV-1 using the TZM-bl beta-galactosidase assay with primary isolates of HIV-1. Results: This study shows that large and complex synthetic DNA sequences can be successfully cloned in a single step into two poxvirus vectors: MVA and FPV and the recombinant poxviruses could be grown to high titres. The vaccine candidates showed appropriate expression of recombinant proteins with the formation of authentic HIV virus-like particles seen on transmission electron microscopy. In addition the b12 epitope was shown to be held in common by the vaccine candidates using confocal immunofluorescent microscopy. The vaccine candidates were safely administered to Chinese cynomolgus macaques which elicited modest T cell responses at the end of the study but only one out of the three macaques elicited an HIV-specific antibody response. However, the antibodies did not neutralise primary isolates of HIV-1 or the V3-sensitive isolate SF162 using the TZM-bl b-galactosidase assay. Conclusions: MVA and FP9 are ideal replication-deficient viral vectors for HIV-1 vaccines due to their excellent safety profile for use in humans. This study shows this novel prime-boost-boost regimen was poorly immunogenic in Chinese cynomolgus macaques

    An Extensive Hubble Space Telescope\textit{Hubble Space Telescope} Study of the Offset and Host Light Distributions of Type I Superluminous Supernovae

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    We present an extensive Hubble Space Telescope\textit{Hubble Space Telescope} (HST\textit{HST}) rest-frame ultraviolet (UV) imaging study of the locations of Type I superluminous supernovae (SLSNe) within their host galaxies. The sample includes 65 SLSNe with detected host galaxies in the redshift range z0.052z\approx 0.05-2. Using precise astrometric matching with SN images, we determine the distributions of physical and host-normalized offsets relative to the host centers, as well as the fractional flux distribution relative to the underlying UV light distribution. We find that the host-normalized offsets of SLSNe roughly track an exponential disk profile, but exhibit an overabundance of sources with large offsets of 1.541.5-4 times their host half-light radius. The SLSNe normalized offsets are systematically larger than those of long gamma-ray bursts (LGRBs), and even Type Ib/c and II SNe. Furthermore, we find that about 40\% of all SLSNe occur in the dimmest regions of their host galaxies (fractional flux of 0), in stark contrast to LGRBs and Type Ib/c and II SNe. We do not detect any significant trends in the locations of SLSNe as a function of redshift, or as a function of explosion and magnetar engine parameters inferred from modeling of their optical lights curves. The significant difference in SLSN locations compared to LGRBs (and normal core-collapse SNe) suggests that at least some of their progenitors follow a different evolutionary path. We speculate that SLSNe arise from massive runaway stars from disrupted binary systems, with velocities of 102\sim 10^2 km s1^{-1}.Comment: 31 pages, 14 figures, 5 tables. Submitted to ApJ. Comments welcome

    Long-lived heteronuclear spin-singlet states

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    We report observation of long-lived spin-singlet states in a 13C-1H spin pair at zero magnetic field. In 13C-labeled formic acid, we observe spin-singlet lifetimes as long as 37 seconds, about a factor of three longer than the T1 lifetime of dipole polarization in the triplet state. We also observe that the lifetime of the singlet-triplet coherence, T2, is longer than T1. Moreover, we demonstrate that this singlet states formed by spins of a heteronucleus and a 1H nucleus, can exhibit longer lifetimes than the respective triplet states in systems consisting of more than two nuclear spins. Although long-lived homonuclear spin-singlet states have been extensively studied, this is the first experimental observation of analogous spin-singlets consisting of a heteronucleus and a proton.Comment: 5 pages, 4 figure

    Rapid effects of 17beta-estradiol on TRPV5 epithelial Ca2+ channels in rat renal cells.

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    The renal distal tubules and collecting ducts play a key role in the control of electrolyte and fluid homeostasis. The discovery of highly calcium selective channels, Transient Receptor Potential Vanilloid 5 (TRPV5) of the TRP superfamily, has clarified the nature of the calcium entry channels. It has been proposed that this channel mediates the critical Ca(2+) entry step in transcellular Ca(2+) re-absorption in the kidney. The regulation of transmembrane Ca(2+) flux through TRPV5 is of particular importance for whole body calcium homeostasis.In this study, we provide evidence that the TRPV5 channel is present in rat cortical collecting duct (RCCD(2)) cells at mRNA and protein levels. We demonstrate that 17beta-estradiol (E(2)) is involved in the regulation of Ca(2+) influx in these cells via the epithelial Ca(2+) channels TRPV5. By combining whole-cell patch-clamp and Ca(2+)-imaging techniques, we have characterized the electrophysiological properties of the TRPV5 channel and showed that treatment with 20-50nM E(2) rapidly (\u3c5min) induced a transient increase in inward whole-cell currents and intracellular Ca(2+) via TRPV5 channels. This rise was significantly prevented when cells were pre-treated with ruthenium red and completely abolished in cells treated with siRNA specifically targeting TRPV5.These data demonstrate for the first time, a novel rapid modulation of endogenously expressed TRPV5 channels by E(2) in kidney cells. Furthermore, the results suggest calcitropic effects of E(2). The results are discussed in relation to present concepts of non-genomic actions of E(2) in Ca(2+) homeostasis

    One thousand days of SN 2015bn: HST imaging shows a light curve flattening consistent with magnetar predictions

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    We present the first observations of a Type I superluminous supernova (SLSN) at 1000\gtrsim 1000 days after maximum light. We observed SN 2015bn using the Hubble Space Telescope Advanced Camera for Surveys in the F475W, F625W and F775W filters at 721 days and 1068 days. SN 2015bn is clearly detected and resolved from its compact host, allowing reliable photometry. A galaxy template constructed from these data further enables us to isolate the SLSN flux in deep ground-based imaging. We measure a light curve decline rate at >700>700 days of 0.19±0.030.19 \pm 0.03 mag (100 d)1^{-1}, much shallower than the earlier evolution, and slower than previous SLSNe (at any phase) or the decay rate of 56^{56}Co. Neither additional radioactive isotopes nor a light echo can consistently account for the slow decline. A spectrum at 1083 days shows the same [O I] and [Ca II] lines as seen at 300400\sim300-400 days, with no new features to indicate strong circumstellar interaction. Radio limits with the Very Large Array rule out an extended wind for mass-loss rates 102.7M˙/v10101.110^{-2.7} \lesssim \dot{M}/v_{10} \lesssim 10^{-1.1} M_\odot yr1^{-1} (where v10v_{10} is the wind velocity in units of 10 km s1^{-1}). The optical light curve is consistent with Lt4L \propto t^{-4}, which we show is expected for magnetar spin-down with inefficient trapping; furthermore, the evolution matches predictions from earlier magnetar model fits. The opacity to magnetar radiation is constrained at 0.01\sim 0.01 cm2^2 g1^{-1}, consistent with photon-matter pair-production over a broad \simGeV-TeV range. This suggests the magnetar spectral energy distribution, and hence the 'missing energy' leaking from the ejecta, may peak in this range.Comment: Accepted for publication in ApJL, updated to match accepted versio

    Parameter uncertainty of a dynamic multispecies size spectrum model

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    Dynamic size spectrum models have been recognized as an effective way of describing how size-based interactions can give rise to the size structure of aquatic communities. They are intermediate-complexity ecological models that are solutions to partial differential equations driven by the size-dependent processes of predation, growth, mortality, and reproduction in a community of interacting species and sizes. To be useful for quantitative fisheries management these models need to be developed further in a formal statistical framework. Previous work has used time-averaged data to “calibrate” the model using optimization methods with the disadvantage of losing detailed time-series information. Using a published multispecies size spectrum model parameterized for the North Sea comprising 12 interacting fish species and a background resource, we fit the model to time-series data using a Bayesian framework for the first time. We capture the 1967–2010 period using annual estimates of fishing mortality rates as input to the model and time series of fisheries landings data to fit the model to output. We estimate 38 key parameters representing the carrying capacity of each species and background resource, as well as initial inputs of the dynamical system and errors on the model output. We then forecast the model forward to evaluate how uncertainty propagates through to population- and community-level indicators under alternative management strategies

    Civil Statutes of Limitation for Child Sexual Abuse and Domestic Minor Sex Trafficking

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    The Wilbanks Child Endangerment and Sexual Exploitation (CEASE) Clinic is a teaching and research clinic at the University of Georgia School of Law. The clinic represents survivors of childhood sexual abuse and exploitation in civil and juvenile dependency proceedings. Since opening its doors in 2016, CEASE has assisted over 100 survivors in the state of Georgia through legal representation, legal advice, and/or referrals. Law and masters of social work students work in the clinic and participate in a seminar covering best practices in representing survivors, relevant laws and policies, and practical legal and social work skills. Law students represent survivors under attorney supervision and engage in policy research on issues affecting survivors. As a unit of the University of Georgia, the CEASE Clinic does not engage in lobbying activities and does not endorse any specific legislation. This report is a summary of research on child sexual abuse, how Georgia compares to other states and national trends in providing civil remedies to survivors, common concerns with allowing retroactive claims, and the impact of civil lawsuits on survivors and entities

    Assessing fishery and ecological consequences of alternate management options for multispecies fisheries

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    Demands for management advice on mixed and multispecies fisheries pose many challenges, further complicated by corresponding requests for advice on the environmental impacts of alternate management options. Here, we develop, and apply to North Sea fisheries, a method for collectively assessing the effects of, and interplay between, technical interactions, multispecies interactions, and the environmental effects of fishing. Ecological interactions involving 21 species are characterized with an ensemble of 188 plausible parameterizations of size-based multispecies models, and four fleets (beam trawl, otter trawl, industrial, and pelagic) characterized with catch composition data. We use the method to evaluate biomass and economic yields, alongside the risk of stock depletion and changes in the value of community indicators, for 10 000 alternate fishing scenarios (combinations of rates of fishing mortality F and fleet configuration) and present the risk vs. reward trade-offs. Technical and multispecies interactions linked to the beam and otter trawl fleets were predicted to have the strongest effects on fisheries yield and value, risk of stock collapse and fish community indicators. Increasing beam trawl effort led to greater increases in beam trawl yield when otter trawl effort was low. If otter trawl effort was high, increases in beam trawl effort led to reduced overall yield. Given the high value of demersal species, permutations of fleet effort leading to high total yield (generated primarily by pelagic species) were not the same as permutations leading to high catch values. A transition from F for 1990 to 2010 to FMSY, but without changes in fleet configuration, reduced risk of stock collapse without affecting long-term weight or value of yield. Our approach directly addresses the need for assessment methods that treat mixed and multispecies issues collectively, address uncertainty, and take account of trade-offs between weight and value of yield, state of stocks and state of the environment
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