65 research outputs found

    Sideband cooling and coherent dynamics in a microchip multi-segmented ion trap

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    Miniaturized ion trap arrays with many trap segments present a promising architecture for scalable quantum information processing. The miniaturization of segmented linear Paul traps allows partitioning the microtrap in different storage and processing zones. The individual position control of many ions - each of them carrying qubit information in its long-lived electronic levels - by the external trap control voltages is important for the implementation of next generation large-scale quantum algorithms. We present a novel scalable microchip multi-segmented ion trap with two different adjacent zones, one for the storage and another dedicated for the processing of quantum information using single ions and linear ion crystals: A pair of radio-frequency driven electrodes and 62 independently controlled DC electrodes allows shuttling of single ions or linear ion crystals with numerically designed axial potentials at axial and radial trap frequencies of a few MHz. We characterize and optimize the microtrap using sideband spectroscopy on the narrow S1/2 D5/2 qubit transition of the 40Ca+ ion, demonstrate coherent single qubit Rabi rotations and optical cooling methods. We determine the heating rate using sideband cooling measurements to the vibrational ground state which is necessary for subsequent two-qubit quantum logic operations. The applicability for scalable quantum information processing is proven.Comment: 17 pages, 11 figure

    Norovirus Transmission on Cruise Ship

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    We documented transmission by food and person-to-person contact; persistence of virus despite sanitization onboard, including introductions of new strains; and seeding of an outbreak on land

    Norovirus Detection and Genotyping for Children with Gastroenteritis, Brazil

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    During 1998–2005, we analyzed stool samples from 289 children in Rio de Janeiro to detect and genotype norovirus strains. Previous tests showed all samples to be negative for rotavirus and adenovirus. Of 42 (14.5%) norovirus-positive specimens, 20 (47.6%) were identified as genogroup GI and 22 (52.3%) as GII

    SARS-associated Coronavirus Transmission, United States

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    To better assess the risk for transmission of the severe acute respiratory syndrome–associated coronavirus (SARS-CoV), we obtained serial specimens and clinical and exposure data from seven confirmed U.S. SARS patients and their 10 household contacts. SARS-CoV was detected in a day-14 sputum specimen from one case-patient and in five stool specimens from two case-patients. In one case-patient, SARS-CoV persisted in stool for at least 26 days after symptom onset. The highest amounts of virus were in the day-14 sputum sample and a day-14 stool sample. Residual respiratory symptoms were still present in recovered SARS case-patients 2 months after illness onset. Possible transmission of SARS-CoV occurred in one household contact, but this person had also traveled to a SARS-affected area. The data suggest that SARS-CoV is not always transmitted efficiently. Laboratory diagnosis of SARS-CoV infection is difficult; thus, sputum and stool specimens should be included in the diagnostic work-up for SARS-CoV infection

    Sixteen diverse laboratory mouse reference genomes define strain-specific haplotypes and novel functional loci.

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    We report full-length draft de novo genome assemblies for 16 widely used inbred mouse strains and find extensive strain-specific haplotype variation. We identify and characterize 2,567 regions on the current mouse reference genome exhibiting the greatest sequence diversity. These regions are enriched for genes involved in pathogen defence and immunity and exhibit enrichment of transposable elements and signatures of recent retrotransposition events. Combinations of alleles and genes unique to an individual strain are commonly observed at these loci, reflecting distinct strain phenotypes. We used these genomes to improve the mouse reference genome, resulting in the completion of 10 new gene structures. Also, 62 new coding loci were added to the reference genome annotation. These genomes identified a large, previously unannotated, gene (Efcab3-like) encoding 5,874 amino acids. Mutant Efcab3-like mice display anomalies in multiple brain regions, suggesting a possible role for this gene in the regulation of brain development

    Reduced evolutionary rate in reemerged Ebola virus transmission chains

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    On 29 June 2015, Liberia’s respite from Ebola virus disease (EVD) was interrupted for the second time by a renewed outbreak (“flare-up”) of seven confirmed cases. We demonstrate that, similar to the March 2015 flare-up associated with sexual transmission, this new flare-up was a reemergence of a Liberian transmission chain originating from a persistently infected source rather than a reintroduction from a reservoir or a neighboring country with active transmission. Although distinct, Ebola virus (EBOV) genomes from both flare-ups exhibit significantly low genetic divergence, indicating a reduced rate of EBOV evolution during persistent infection. Using this rate of change as a signature, we identified two additional EVD clusters that possibly arose from persistently infected sources. These findings highlight the risk of EVD flare-ups even after an outbreak is declared over

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
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