207 research outputs found

    The First Billion Years

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    Spectral measurements of atomic and molecular lines embedded in the cosmic microwave background (CMB) have the potential to open entirely new probes of the early Universe. Two avenues are of great interest: 1) Spectral line deviations from the CMB blackbody spectrum will enable the study of hydrogen and helium recombination physics during and before the time of the surface of last scattering, and could provide the potential for game-changing discoveries by testing dark matter annihilation in the redshift range 6000> z > 1000, by allowing a test of the time-dependence of the fine-structure constant at a critical epoch, and by testing inflation models using an independent method. 2) Extension of CMB anisotropy measurements to detect unresolved spectral line emission from starforming galaxies during reionization (6 < z < 10) would directly delineate the large-scale structure of the galaxies responsible for reionizing the Universe and provide the only foreseeable measurements on scales sufficiently large to compare with upcoming observations of reionization by way of the redshifted hydrogen 21 cm line. CO, [C II], and Ly-a lines were investigated as promising targets. CO and [C II] line transitions emerged as particularly compelling. The two science objectives identified in the Program share some common core technological requirements based on the shared need for approximately 1000-element feed arrays followed by broadband, highresolution spectral correlators. The technical requirements lead to a roadmap for development of large feed arrays beginning with applications in a ground-based CO mapping instrument and leading to a spaceborne recombination-line all-sky spectrometer. The key technical issues include compact and light-weight integrated spectral dual-polarization inexpensive receiver modules, large high-resolution spectral correlators (analog and/or digital), and light-weight feeds. In parallel we recommend long-term investigations into high precision calibrators and calibration techniques that will be required for the recombination line instrument. A second roadmap addresses technical developments required for a 2-D spectroscopic instrument for [C II] mapping

    The First Billion Years

    Get PDF
    Spectral measurements of atomic and molecular lines embedded in the cosmic microwave background (CMB) have the potential to open entirely new probes of the early Universe. Two avenues are of great interest: 1) Spectral line deviations from the CMB blackbody spectrum will enable the study of hydrogen and helium recombination physics during and before the time of the surface of last scattering, and could provide the potential for game-changing discoveries by testing dark matter annihilation in the redshift range 6000> z > 1000, by allowing a test of the time-dependence of the fine-structure constant at a critical epoch, and by testing inflation models using an independent method. 2) Extension of CMB anisotropy measurements to detect unresolved spectral line emission from starforming galaxies during reionization (6 < z < 10) would directly delineate the large-scale structure of the galaxies responsible for reionizing the Universe and provide the only foreseeable measurements on scales sufficiently large to compare with upcoming observations of reionization by way of the redshifted hydrogen 21 cm line. CO, [C II], and Ly-a lines were investigated as promising targets. CO and [C II] line transitions emerged as particularly compelling. The two science objectives identified in the Program share some common core technological requirements based on the shared need for approximately 1000-element feed arrays followed by broadband, highresolution spectral correlators. The technical requirements lead to a roadmap for development of large feed arrays beginning with applications in a ground-based CO mapping instrument and leading to a spaceborne recombination-line all-sky spectrometer. The key technical issues include compact and light-weight integrated spectral dual-polarization inexpensive receiver modules, large high-resolution spectral correlators (analog and/or digital), and light-weight feeds. In parallel we recommend long-term investigations into high precision calibrators and calibration techniques that will be required for the recombination line instrument. A second roadmap addresses technical developments required for a 2-D spectroscopic instrument for [C II] mapping

    Long-range depth imaging using a single-photon detector array and non-local data fusion

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    The ability to measure and record high-resolution depth images at long stand-off distances is important for a wide range of applications, including connected and automotive vehicles, defense and security, and agriculture and mining. In LIDAR (light detection and ranging) applications, single-photon sensitive detection is an emerging approach, offering high sensitivity to light and picosecond temporal resolution, and consequently excellent surface-to-surface resolution. The use of large format CMOS (complementary metal-oxide semiconductor) single-photon detector arrays provides high spatial resolution and allows the timing information to be acquired simultaneously across many pixels. In this work, we combine state-of-the-art single-photon detector array technology with non-local data fusion to generate high resolution three-dimensional depth information of long-range targets. The system is based on a visible pulsed illumination system at a wavelength of 670 nm and a 240 × 320 array sensor, achieving sub-centimeter precision in all three spatial dimensions at a distance of 150 meters. The non-local data fusion combines information from an optical image with sparse sampling of the single-photon array data, providing accurate depth information at low signature regions of the target

    Sex differences in infant vocalization and the origin of language

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    Seeking to discern the earliest sex differences in language-related activities, our focus is vocal activity in the first two years of life, following up on recent research that unexpectedly showed boys produced significantly more speech-like vocalizations (protophones) than girls during the first year of life.We now bring a much larger body of data to bear on the comparison of early sex differences in vocalization, data based on automated analysis of all-day recordings of infants in their homes. The new evidence, like that of the prior study, also suggests boys produce more protophones than girls in the first year and offers additional basis for informed speculation about biological reasons for these differences. More broadly, the work offers a basis for informed speculations about foundations of language that we propose to have evolved in our distant hominin ancestors, foundations also required in early vocal development of modern human infants

    Provision of NHS generalist and specialist services to care homes in England: review of surveys

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    Background: The number of beds in care homes (with and without nurses) in the United Kingdom is three times greater than the number of beds in National Health Service (NHS) hospitals. Care homes are predominantly owned by a range of commercial, not-for-profit or charitable providers and their residents have high levels of disability, frailty and co-morbidity. NHS support for care home residents is very variable, and it is unclear what models of clinical support work and are cost-effective. Objectives: To critically evaluate how the NHS works with care homes.MethodsA review of surveys of NHS services provided to care homes that had been completed since 2008. It included published national surveys, local surveys commissioned by Primary Care organisations, studies from charities and academic centres, grey literature identified across the nine government regions, and information from care home, primary care and other research networks. Data extraction captured forms of NHS service provision for care homes in England in terms of frequency, location, focus and purpose. Results: Five surveys focused primarily on general practitioner services, and 10 on specialist services to care home. Working relationships between the NHS and care homes lack structure and purpose and have generally evolved locally. There are wide variations in provision of both generalist and specialist healthcare services to care homes. Larger care home chains may take a systematic approach to both organising access to NHS generalist and specialist services, and to supplementing gaps with in-house provision. Access to dental care for care home residents appears to be particularly deficient. Conclusions:Historical differences in innovation and provision of NHS services, the complexities of collaborating across different sectors (private and public, health and social care, general and mental health), and variable levels of organisation of care homes, all lead to persistent and embedded inequity in the distribution of NHS resources to this population. Clinical commissioners seeking to improve the quality of care of care home residents need to consider how best to provide fair access to health care for older people living in a care home, and to establish a specification for service delivery to this vulnerable population
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