187 research outputs found
AS-204/LM-1 launch vehicle operational flight trajectory
Apollo Saturn-204/LM-1 launch vehicle operational flight trajector
A Traveling-Wave Parametric Amplifier and Converter
High-fidelity qubit measurement is a critical element of all quantum
computing architectures. In superconducting systems, qubits are typically
measured by probing a readout resonator with a weak microwave tone which must
be amplified before reaching the room temperature electronics. Superconducting
parametric amplifiers have been widely adopted as the first amplifier in the
chain, primarily because of their low noise performance, approaching the
quantum limit. However, they require isolators and circulators to route signals
up the measurement chain, as well as to protect qubits from amplified noise.
While these commercial components are wideband and very simple to use, their
intrinsic loss, size, and magnetic shielding requirements impact the overall
measurement efficiency while also limiting prospects for scalable readout in
large-scale superconducting quantum computers. Here we demonstrate a parametric
amplifier that achieves both broadband forward amplification and backward
isolation in a single, compact, non-magnetic circuit that could be integrated
on chip with superconducting qubits. It relies on a nonlinear transmission line
which supports traveling-wave parametric amplification of forward propagating
signals, and isolation via frequency conversion of backward propagating
signals. This kind of traveling-wave parametric amplifier and converter is
poised to reduce the readout hardware overhead when scaling up the size of
superconducting quantum computers
Evaluation of the novel substrate RUGtm for the detection of Escherichia coli in water from temperate (Zurich, Switzerland) and tropical (Bushenyi, Uganda) field sites
Direct testing of water quality to promote drinking water safety contributes to the sustainable development goals, which call for universal access to safely-managed drinking water services by 2030. Enzyme–substrate tests offer a potentially simple and reliable approach for the detection and quantification of fecal indicator bacteria, including Escherichia coli (E. coli). The novel aquatest (AT) based on resorufin-β-D-glucuronide methyl ester (RUG™) (AT-RUG) is an enzyme–substrate test that overcomes several drawbacks of other established tests. In this study, AT-RUG was used to detect and quantify E. coli in water from temperate (Zurich, Switzerland) and tropical (Bushenyi, Uganda) regions. Quantitative results of AT-RUG were compared with IDEXX Colilert-18® (C-18), m-TEC and m-ColiBlue24®. In temperate waters, AT-RUG was found to be as sensitive as m-TEC (97.0%) and C-18 (98.5%) and showed strong agreement with the reference methods. The false-positive rate for E. coli detection in temperate waters using AT-RUG was 6%. AT-RUG performed well at incubation temperatures of 37 °C and 45 °C, but not at 24 °C. In tropical waters, AT-RUG sensitivity was 94.1% compared to m-ColiBlue24®. AT-RUG detected significantly more E. coli than m-ColiBlue24®, suggesting it is a more conservative estimate. At both field sites, AT-RUG was able to effectively indicate categorical concentrations of E. coli in water samples indicating the level of risks of fecal contamination of water supplies. This study indicates that AT-RUG is a reliable and accurate medium for the detection and quantification of E. coli in temperate and tropical waters
Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 108 (2011):9148-9153, doi:10.1073/pnas.1019090108.Camouflage is a widespread phenomenon throughout nature and an important
anti-predator tactic in natural selection. Many visual predators have keen color
perception, thus camouflage patterns should provide some degree of color matching in
addition to other visual factors such as pattern, contrast, and texture. Quantifying
camouflage effectiveness in the eyes of the predator is a challenge from the
perspectives of both biology and optical imaging technology. Here we take advantage
of Hyperspectral Imaging (HSI), which records full-spectrum light data, to
simultaneously visualize color match and pattern match in the spectral and the spatial
domains, respectively. Cuttlefish can dynamically camouflage themselves on any
natural substrate and, despite their colorblindness, produce body patterns that appear
to have high-fidelity color matches to the substrate when viewed directly by humans
or with RGB images. Live camouflaged cuttlefish on natural backgrounds were
imaged using HSI, and subsequent spectral analysis revealed that most reflectance
spectra of individual cuttlefish and substrates were similar, rendering the color match
possible. Modeling color vision of potential di- and tri-chromatic fish predators of
cuttlefish corroborated the spectral match analysis and demonstrated that camouflaged
cuttlefish show good color match as well as pattern match in the eyes of fish predators.
These findings (i) indicate the strong potential of HSI technology to enhance studies
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of biological coloration, and (ii) provide supporting evidence that cuttlefish can
produce color-coordinated camouflage on natural substrates despite lacking color
vision.We gratefully acknowledge financial support from the
National Science Council of Taiwan NSC-98-2628-B-007-001-MY3 to CCC, from
the Network Science Center at West Point and the Army Research Office to JKW,
from the NDSEG Fellowship to JJA, and from ONR grant N000140610202 to RTH
Estimating food production in an urban landscape
There is increasing interest in urban food production for reasons of food security, environmental sustainability, social and health benefits. In developed nations urban food growing is largely informal and localised, in gardens, allotments and public spaces, but we know little about the magnitude of this production. Here we couple own-grown crop yield data with garden and allotment areal surveys and urban fruit tree occurrence to provide one of the first estimates for current and potential food production in a UK urban setting. Current production is estimated to be sufficient to supply the urban population with fruit and vegetables for about 30 days per year, while the most optimistic model results suggest that existing land cultivated for food could supply over half of the annual demand. Our findings provide a baseline for current production whilst highlighting the potential for change under the scaling up of cultivation on existing land
At Least Ten Genes Define the Imprinted Dlk1-Dio3 Cluster on Mouse Chromosome 12qF1
Background: Genomic imprinting is an exception to Mendelian genetics in that imprinted genes are expressed monoallelically, dependent on parental origin. In mammals, imprinted genes are critical in numerous developmental and physiological processes. Aberrant imprinted gene expression is implicated in several diseases including Prader-Willi/ Angelman syndromes and cancer. Methodology/Principal Findings: To identify novel imprinted genes, transcription profiling was performed on two uniparentally derived cell lines, androgenetic and parthenogenetic primary mouse embryonic fibroblasts. A maternally expressed transcript termed Imprinted RNA near Meg3/Gtl2 (Irm) was identified and its expression studied by Northern blotting and whole mounts in situ hybridization. The imprinted region that contains Irm has a parent of origin effect in three mammalian species, including the sheep callipyge locus. In mice and humans, both maternal and paternal uniparental disomies (UPD) cause embryonic growth and musculoskeletal abnormalities, indicating that both alleles likely express essential genes. To catalog all imprinted genes in this chromosomal region, twenty-five mouse mRNAs in a 1.96Mb span were investigated for allele specific expression. Conclusions/Significance: Ten imprinted genes were elucidated. The imprinting of three paternally expressed protein coding genes (Dlk1, Peg11, and Dio3) was confirmed. Seven noncoding RNAs (Meg3/Gtl2, Anti-Peg11, Meg8, Irm/‘‘Rian’’
Microstructural and petrophysical properties of the Permo-Triassic sandstones (Buntsandstein) from the Soultz-sous-Forêts geothermal site (France)
Quantitative analysis of language production in Parkinson's disease using a cued sentence generation task
Ancestral diversity improves discovery and fine-mapping of genetic loci for anthropometric traits — The Hispanic/Latino Anthropometry Consortium
Hispanic/Latinos have been underrepresented in genome-wide association studies (GWAS) for anthropometric traits despite their notable anthropometric variability, ancestry proportions, and high burden of growth stunting and overweight/obesity. To address this knowledge gap, we analyzed densely imputed genetic data in a sample of Hispanic/Latino adults to identify and fine-map genetic variants associated with body mass index (BMI), height, and BMI-adjusted waist-to-hip ratio (WHRadjBMI). We conducted a GWAS of 18 studies/consortia as part of the Hispanic/Latino Anthropometry (HISLA) Consortium (stage 1, n = 59,771) and generalized our findings in 9 additional studies (stage 2, n = 10,538). We conducted a trans-ancestral GWAS with summary statistics from HISLA stage 1 and existing consortia of European and African ancestries. In our HISLA stage 1 + 2 analyses, we discovered one BMI locus, as well as two BMI signals and another height signal each within established anthropometric loci. In our trans-ancestral meta-analysis, we discovered three BMI loci, one height locus, and one WHRadjBMI locus. We also identified 3 secondary signals for BMI, 28 for height, and 2 for WHRadjBMI in established loci. We show that 336 known BMI, 1,177 known height, and 143 known WHRadjBMI (combined) SNPs demonstrated suggestive transferability (nominal significance and effect estimate directional consistency) in Hispanic/Latino adults. Of these, 36 BMI, 124 height, and 11 WHRadjBMI SNPs were significant after trait-specific Bonferroni correction. Trans-ancestral meta-analysis of the three ancestries showed a small-to-moderate impact of uncorrected population stratification on the resulting effect size estimates. Our findings demonstrate that future studies may also benefit from leveraging diverse ancestries and differences in linkage disequilibrium patterns to discover novel loci and additional signals with less residual population stratification
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