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  • 1
    In: Nature, Springer Science and Business Media LLC, Vol. 600, No. 7889 ( 2021-12-16), p. 472-477
    Abstract: The genetic make-up of an individual contributes to the susceptibility and response to viral infection. Although environmental, clinical and social factors have a role in the chance of exposure to SARS-CoV-2 and the severity of COVID-19 1,2 , host genetics may also be important. Identifying host-specific genetic factors may reveal biological mechanisms of therapeutic relevance and clarify causal relationships of modifiable environmental risk factors for SARS-CoV-2 infection and outcomes. We formed a global network of researchers to investigate the role of human genetics in SARS-CoV-2 infection and COVID-19 severity. Here we describe the results of three genome-wide association meta-analyses that consist of up to 49,562 patients with COVID-19 from 46 studies across 19 countries. We report 13 genome-wide significant loci that are associated with SARS-CoV-2 infection or severe manifestations of COVID-19. Several of these loci correspond to previously documented associations to lung or autoimmune and inflammatory diseases 3–7 . They also represent potentially actionable mechanisms in response to infection. Mendelian randomization analyses support a causal role for smoking and body-mass index for severe COVID-19 although not for type II diabetes. The identification of novel host genetic factors associated with COVID-19 was made possible by the community of human genetics researchers coming together to prioritize the sharing of data, results, resources and analytical frameworks. This working model of international collaboration underscores what is possible for future genetic discoveries in emerging pandemics, or indeed for any complex human disease.
    Type of Medium: Online Resource
    ISSN: 0028-0836 , 1476-4687
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    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 120714-3
    detail.hit.zdb_id: 1413423-8
    SSG: 11
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  • 2
    In: Zeitschrift für analytische Chemie, Springer Science and Business Media LLC, Vol. 110, No. 7-8 ( 1937-7), p. 299-303
    Type of Medium: Online Resource
    ISSN: 0016-1152
    Language: German
    Publisher: Springer Science and Business Media LLC
    Publication Date: 1937
    detail.hit.zdb_id: 201093-8
    detail.hit.zdb_id: 1459122-4
    detail.hit.zdb_id: 2071767-2
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  • 3
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2003
    In:  The Journal of the Acoustical Society of America Vol. 114, No. 4_Supplement ( 2003-10-01), p. 2402-2402
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 114, No. 4_Supplement ( 2003-10-01), p. 2402-2402
    Abstract: Changes in the thermocline perturb the acoustic horizontal wave numbers and to a less extent the mode shapes. The measured acoustic field is the combination of modes and phase terms dependent on these wave numbers. Without a full water column spanning time-reversal mirror, inter-modal destructive and constructive interference patterns produce seemingly unpredictable measured fields. As demonstrated in simulation, the field produced by a time-reversal mirror is robust to internal wave perturbation. [Work supported by ONR.]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
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    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2003
    detail.hit.zdb_id: 1461063-2
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  • 4
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2000
    In:  The Journal of the Acoustical Society of America Vol. 108, No. 5_Supplement ( 2000-11-01), p. 2606-2606
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 108, No. 5_Supplement ( 2000-11-01), p. 2606-2606
    Abstract: For a time-independent medium, one can use stored probe pulses to focus on a specific location in time-reversal acoustics. However, the temporal variability of the ocean is expected to limit such a procedure. In the earlier low-frequency (445 Hz) experiments, we found that probe pulses up to 1 week old still produced a significant focus at the original probe source location. In the recent high-frequency (3500 Hz) experiments, however, stability of the focus was limited to less than an hour or even a few minutes, depending upon the oceanographic variability since the acoustic wavelength is much smaller than the one for 445 Hz. A quick and robust diagnosis for the focal stability appears to be the modal group velocity versus phase velocity (gp curves) derived from the sound-speed profile, where the phase speed is directly related to the mode number and the slopes of the curves separate different groups of modes. In this paper, we investigate the stability and scintillation of the focus observed during the May 2000 time-reversal experiment using the gp curves.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
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    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2000
    detail.hit.zdb_id: 1461063-2
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  • 5
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2001
    In:  The Journal of the Acoustical Society of America Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2476-2476
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 109, No. 5_Supplement ( 2001-05-01), p. 2476-2476
    Abstract: Underwater acoustic communications must mitigate the intersymbol interference caused by the time-varying multipath dispersion. An experiment was conducted in June 2000 demonstrating that the time-reversal process recombined the temporal multipath resulting in reduced bit errors for communication. Quantitative bit error results will be shown for BPSK (binary phase shift keying) and QPSK (quadrature phase shift keying). Communication sequences were transmitted over a distance of 10 km both in range-independent and range-dependent environments north of Elba Island, Italy. The range-independent transmissions were made in 100-m-deep water and the range-dependent transmissions were made upslope from 100-m-deep water into 40-deep-water. [Work supported by ONR.]
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
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    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2001
    detail.hit.zdb_id: 1461063-2
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  • 6
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2000
    In:  The Journal of the Acoustical Society of America Vol. 108, No. 5_Supplement ( 2000-11-01), p. 2607-2607
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 108, No. 5_Supplement ( 2000-11-01), p. 2607-2607
    Abstract: The classic difficulty in constructing an acoustic trip line barrier is that the forward-scattered field from the target must be extracted from the (usually) much more intense direct blasting arriving beam, i.e., ‘‘looking into the sunlight effect.’’ During the time-reversal experiment conducted in May 2000, we investigated the forward-scatter barrier concept using a six-element transponder at 65-m depth drifting along with a ship, which traversed the trip line between two moored vertical arrays separated by 5 km in 110-m water depth. A 10-ms cw pulse from a probe source (PS) located at the bottom of the vertical receive array (VRA) is received and time-reversed at the source/receive array (SRA). The transmitted time-reversed signal is then refocused at the PS location of the VRA. This time-reversed signal is also captured by the transponder simulating the forward-scatter target and is retransmitted to the VRA with various amplitudes simulating different forward-scatter target strengths. With an appropriate time delay, the main blast and the transponder signal arrived at the VRA simultaneously. For comparison, one-way broadside transmissions were also made.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
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    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2000
    detail.hit.zdb_id: 1461063-2
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  • 7
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2002
    In:  The Journal of the Acoustical Society of America Vol. 112, No. 1 ( 2002-07-01), p. 189-197
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 112, No. 1 ( 2002-07-01), p. 189-197
    Abstract: Null-broadening, introduced in plane wave beamforming, is extended to an ocean waveguide in the context of matched field processing. The method is based on the minimum variance processor with white noise constraint and the distribution of fictitious sources using the theory of waveguide invariants. The proposed method is demonstrated in simulation as well as with data collected during the SWellEx-96 experiment. As another application, it is shown that the width of a null can be controlled in an adaptive time reversal mirror with a source-receive array.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2002
    detail.hit.zdb_id: 1461063-2
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  • 8
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2006
    In:  The Journal of the Acoustical Society of America Vol. 120, No. 5_Supplement ( 2006-11-01), p. 3007-3008
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 120, No. 5_Supplement ( 2006-11-01), p. 3007-3008
    Abstract: Time reversal (TR), a two-step process, involves time reversing the measured transfer functions from a source and then retransmitting this signal to produce a focus back at the source position. When attempting TR in a fluctuating ocean environment, it is desirable to alter the transmitted signal such that it produces a more robust focus. This has typically been done with work based on frequency domain analysis. In contrast, this work, using oceanic data measured during FAF05, is broadband and the development is totally in the time domain. Different definitions of robustness give different optimal answers to the question of how to design the most robust transformation of the time-reversed data of the first step in the TR process. Two definitions of robustness are studied, one related to outage probability and another related to average power. For each definition, a different approach to a practical approximation is taken. In the case of outage probability, we iteratively solve a minimax optimization problem. In the case of average power, principal component analysis is performed on time-domain data.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
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    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2006
    detail.hit.zdb_id: 1461063-2
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  • 9
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2006
    In:  The Journal of the Acoustical Society of America Vol. 120, No. 4 ( 2006-10-01), p. 2067-2076
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 120, No. 4 ( 2006-10-01), p. 2067-2076
    Abstract: A time reversal mirror exploits spatial diversity to achieve spatial and temporal focusing, a useful property for communications in an environment with significant multipath. Taking advantage of spatial diversity involves using a number of receivers distributed in space. This paper presents the impact of spatial diversity in passive time reversal communications between a probe source (PS) and a vertical receive array using at-sea experimental data, while the PS is either fixed or moving at about 4knots. The performance of two different approaches is compared in terms of output signal-to-noise ratio versus the number of receiver elements: (1) time reversal alone and (2) time reversal combined with adaptive channel equalization. The time-varying channel response due to source motion requires an adaptive channel equalizer such that approach (2) outperforms approach (1) by up to 13dB as compared to 5dB for a fixed source case. Experimental results around 3kHz with a 1kHz bandwidth illustrate that as few as two or three receivers (i.e., 2 or 4m array aperture) can provide reasonable performance at ranges of 4.2 and 10km in 118m deep water.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2006
    detail.hit.zdb_id: 1461063-2
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  • 10
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2005
    In:  The Journal of the Acoustical Society of America Vol. 118, No. 4 ( 2005-10-01), p. 2365-2372
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 118, No. 4 ( 2005-10-01), p. 2365-2372
    Abstract: Time reversal has been shown as an effective way to focus in both time and space. The temporal focusing properties have been used extensively in underwater acoustics communications. Typical time-reversal communication experiments use vertical transducer arrays both to increase the signal-to-noise ratio and decrease the temporal sidelobes created in the time reversal process. Comparable temporal focusing is achieved using a horizontal array. In this paper, synthetic aperture time-reversal communications are accomplished, requiring only two transducers (one transmitter and one receiver). Deriving results from an at-sea experiment, this work confirms the viability of synthetic aperture time-reversal communications.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2005
    detail.hit.zdb_id: 1461063-2
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