3,150 research outputs found

    Albert Camus: Philosopher -- Artist

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    In lieu of an abstract, below is the essay\u27s first paragraph. Much of modern fiction, whether it can be said to be existential in theme or not, is concerned with deep philosophical problems. The rapid technological development and increase in the very tempo of our lives so noticeable in the Twentieth Century has caused many thinkers to re-evaluate and rediscover fundamental truths and ideas. A sense of isolation or estrangement from other men and from God is a dominant theme in today\u27s writing. Modern man feels lost or alone when he observes the world around him. Thrown hack upon the limited resources of his own mind, each thinking man feels a need for making absolute truths applicable in his own life

    Going On Ten

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    In lieu of an abstract, below is the essay\u27s first paragraph. All of a sudden, on Christmas Eve, my old dog Prince decided to die. Me and my dad found him the next day stretched out in front of his doghouse with his leash all twisted around the old Chestnut tree. My dad said that he probably died of a broken heart because be couldn\u27t catch Santa Claus and his reindeer (he thought I still believed in him). But I once heard that when dogs get old they sometimes die of mistemper. Besides, old Prince never would have noticed Santa, because as my dad used to say, He\u27s deaf in one ear and can\u27t hear a thing out of the other, and he was getting kind of blind too. He was real old, old Prince was. He and I were the same people age, nine, but in dog\u27s age he was a lot older, older than my grandmother who used to stay in bed all the time and cry every time me and my dad went to see her. Old Prince didn\u27t Stay in bed though, and he never cried, except for one time when my big brother hit him in the side with a football. But, as I said, old Prince died, so me and my dad scraped away some snow, dug a hole, and buried him. We even put a wooden cross on his grave

    Rydberg excitation of a single trapped ion

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    We demonstrate excitation of a single trapped cold 40^{40}Ca+^+ ion to Rydberg levels by laser radiation in the vacuum-ultraviolet at 122 nm wavelength. Observed resonances are identified as 3d2^2D3/2_{3/2} to 51 F, 52 F and 3d2^2D5/2_{5/2} to 64F. We model the lineshape and our results imply a large state-dependent coupling to the trapping potential. Rydberg ions are of great interest for future applications in quantum computing and simulation, in which large dipolar interactions are combined with the superb experimental control offered by Paul traps.Comment: 4 pages, 3 figure

    Vanishing Fe 3d orbital moments in single-crystalline magnetite

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    We show detailed magnetic absorption spectroscopy results of an in situ cleaved high quality single crystal of magnetite. In addition the experimental setup was carefully optimized to reduce drift, self absorption, and offset phenomena as far as possible. In strong contradiction to recently published data, our observed orbital moments are nearly vanishing and the spin moments are quite close to the integer values proposed by theory. This very important issue supports the half metallic full spin polarized picture of magnetite.Comment: 7 pages, 4 figure

    Mouse Models of Genomic Syndromes as Tools for Understanding the Basis of Complex Traits: An Example with the Smith-Magenis and the Potocki-Lupski Syndromes

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    Each human's genome is distinguished by extra and missing DNA that can be “benign” or powerfully impact everything from development to disease. In the case of genomic disorders DNA rearrangements, such as deletions or duplications, correlate with a clinical specific phenotype. The clinical presentations of genomic disorders were thought to result from altered gene copy number of physically linked dosage sensitive genes. Genomic disorders are frequent diseases (~1 per 1,000 births). Smith-Magenis syndrome (SMS) and Potocki-Lupski syndrome (PTLS) are genomic disorders, associated with a deletion and a duplication, of 3.7 Mb respectively, within chromosome 17 band p11.2. This region includes 23 genes. Both syndromes have complex and distinctive phenotypes including multiple congenital and neurobehavioral abnormalities. Human chromosome 17p11.2 is syntenic to the 32-34 cM region of murine chromosome 11. The number and order of the genes are highly conserved. In this review, we will exemplify how genomic disorders can be modeled in mice and the advantages that such models can give in the study of genomic disorders in particular and gene copy number variation (CNV) in general. The contributions of the SMS and PTLS animal models in several aspects ranging from more specific ones, as the definition of the clinical aspects of the human clinical spectrum, the identification of dosage sensitive genes related to the human syndromes, to the more general contributions as the definition of genetic locus impacting obesity and behavior and the elucidation of general mechanisms related to the pathogenesis of gene CNV are discussed

    E2 strengths and transition radii difference of one-phonon 2+ states of 92Zr from electron scattering at low momentum transfer

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    Background: Mixed-symmetry 2+ states in vibrational nuclei are characterized by a sign change between dominant proton and neutron valence-shell components with respect to the fully symmetric 2+ state. The sign can be measured by a decomposition of proton and neutron transition radii with a combination of inelastic electron and hadron scattering [C. Walz et al., Phys. Rev. Lett. 106, 062501 (2011)]. For the case of 92Zr, a difference could be experimentally established for the neutron components, while about equal proton transition radii were indicated by the data. Method: Differential cross sections for the excitation of one-phonon 2+ and 3- states in 92Zr have been measured with the (e,e') reaction at the S-DALINAC in a momentum transfer range q = 0.3-0.6 fm^(-1). Results: Transition strengths B(E2;2+_1 -> 0+_1) = 6.18(23), B(E2; 2+_2 -> 0+_1) = 3.31(10) and B(E3; 3-_1 -> 0+_1) = 18.4(11) Weisskopf units are determined from a comparison of the experimental cross sections to quasiparticle-phonon model (QPM) calculations. It is shown that a model-independent plane wave Born approximation (PWBA) analysis can fix the ratio of B(E2) transition strengths to the 2+_(1,2) states with a precision of about 1%. The method furthermore allows to extract their proton transition radii difference. With the present data -0.12(51) fm is obtained. Conclusions: Electron scattering at low momentum transfers can provide information on transition radii differences of one-phonon 2+ states even in heavy nuclei. Proton transition radii for the 2+_(1,2) states in 92Zr are found to be identical within uncertainties. The g.s. transition probability for the mixed-symmetry state can be determined with high precision limited only by the available experimental information on the B(E2; 2+_1 -> 0+_1) value.Comment: 14 pages, 5 figures, submitted to Phys. Rev. C, revised manuscrip

    Anti-malarial ozonides OZ439 and OZ609 tested at clinically relevant compound exposure parameters in a novel ring-stage survival assay

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    BACKGROUND: Drug efficacy against kelch 13 mutant malaria parasites can be determined in vitro with the ring-stage survival assay (RSA). The conventional assay protocol reflects the exposure profile of dihydroartemisinin. METHODS: Taking into account that other anti-malarial peroxides, such as the synthetic ozonides OZ439 (artefenomel) and OZ609, have different pharmacokinetics, the RSA was adjusted to the concentration-time profile of these ozonides in humans and a novel, semi-automated readout was introduced. RESULTS: When tested at clinically relevant parameters, it was shown that OZ439 and OZ609 are active against the Plasmodium falciparum clinical isolate Cam3.I(R539T). CONCLUSION: If the in vitro RSA does indeed predict the potency of compounds against parasites with increased tolerance to artemisinin and its derivatives, then the herein presented data suggest that following drug-pulses of at least 48 h, OZ439 and OZ609 will be highly potent against kelch 13 mutant isolates, such as P. falciparum Cam3.I(R539T)

    Cross-Scale Vulnerability Assessment for Smallholder Farming: A Case Study from the Northeast of Brazil

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    Climate change heavily impacts smallholder farming worldwide. Cross-scale vulnerability assessment has a high potential to identify nested measures for reducing vulnerability of smallholder farmers. Despite their high practical value, there are currently only limited examples of cross-scale assessments. The presented study aims at assessing the vulnerability of smallholder farmers in the Northeast of Brazil across three scales: regional, farm and field scale. In doing so, it builds on existing vulnerability indices and compares results between indices at the same scale and across scales. In total, six independent indices are tested, two at each scale. The calculated indices include social, economic and ecological indicators, based on municipal statistics, meteorological data, farm interviews and soil analyses. Subsequently, indices and overlapping indicators are normalized for intra- and cross-scale comparison. The results show considerable differences between indices across and within scales. They indicate different activities to reduce vulnerability of smallholder farmers. Major shortcomings arise from the conceptual differences between the indices. We therefore recommend the development of hierarchical indices, which are adapted to local conditions and contain more overlapping indicators for a better understanding of the nested vulnerabilities of smallholder farmers
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