17 research outputs found

    Quantization Noise Shaping for Information Maximizing ADCs

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    ADCs sit at the interface of the analog and digital worlds and fundamentally determine what information is available in the digital domain for processing. This paper shows that a configurable ADC can be designed for signals with non constant information as a function of frequency such that within a fixed power budget the ADC maximizes the information in the converted signal by frequency shaping the quantization noise. Quantization noise shaping can be realized via loop filter design for a single channel delta sigma ADC and extended to common time and frequency interleaved multi channel structures. Results are presented for example wireline and wireless style channels.Comment: 4 pages, 6 figure

    Some observations on high resolution thermogravimetry

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    Alternative models of cardiac rehabilitation: a systematic review

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    The traditional hospital-based model of cardiac rehabilitation faces substantial challenges, such as cost and accessibility. These challenges have led to the development of alternative models of cardiac rehabilitation in recent years. The aim of this study was to identify and critique evidence for the effectiveness of these alternative models. A total of 22 databases were searched to identify quantitative studies or systematic reviews of quantitative studies regarding the effectiveness of alternative models of cardiac rehabilitation. Included studies were appraised using a Critical Appraisal Skills Programme tool and the National Health and Medical Research Council's designations for Level of Evidence. The 83 included articles described interventions in the following broad categories of alternative models of care: multifactorial individualized telehealth, internet based, telehealth focused on exercise, telehealth focused on recovery, community- or home-based, and complementary therapies. Multifactorial individualized telehealth and community- or home-based cardiac rehabilitation are effective alternative models of cardiac rehabilitation, as they have produced similar reductions in cardiovascular disease risk factors compared with hospital-based programmes. While further research is required to address the paucity of data available regarding the effectiveness of alternative models of cardiac rehabilitation in rural, remote, and culturally and linguistically diverse populations, our review indicates there is no need to rely on hospital-based strategies alone to deliver effective cardiac rehabilitation. Local healthcare systems should strive to integrate alternative models of cardiac rehabilitation, such as brief telehealth interventions tailored to individual's risk factor profiles as well as community- or home-based programmes, in order to ensure there are choices available for patients that best fit their needs, risk factor profile, and preferences

    Detrital zircon provenance of Permo-Carboniferous glacial diamictites across Gondwana

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    Gondwana changed its high latitude location during the late Paleozoic (338–265 Ma), relative to the South Pole, and the style of glaciation evolved from localized alpine glaciers and ice fields to ~30 small ice sheets across the supercontinent. We report the analysis of heavy mineral populations (n = 2217) and the ages of detrital zircons (n = 2920 U-Pb LA-ICPMS results) from Gondwana diamictite deposits from eight landmasses: Africa (5 samples), Antarctica (5), Australia (8), the Ellsworth Mountains terrane (1, Antarctica), the Falkland Islands (2, diamictite plus U-Pb SHRIMP ages on granite clasts), India (1), Madagascar (1), Oman (3), the equatorial Lhasa terrane (2), the equatorial North Qiantang terrane (2) and South America (10). Heavy mineral separations (SEM-WDS analysis) identified one anomaly, pyrope garnets present only in Dwyka Group and Dwyka-equivalent samples suggesting an ultramafic Antarctic source. Statistical analysis of detrital zircon age distributions support the inference of local transport of sediment from many small ice centers with five examples of far-field ice transport (>1000 km; four with ice flow >2000 km), and three from ice fields located along coastal Antarctica. We propose that ice was distributed from five main ice-caps of different ages in southern Gondwana with ice flow away from central Gondwana. We also confirm that the Permo-Carboniferous detrital zircon populations of Euramerica (eolian and fluvial) and Gondwana (ash, detrital-glacial) are not mixed across the equator or seaway and ponder the possibility of a late Paleozoic snowball Earth

    Influence of the physical environment and conspecific aggression on the spatial arrangement of breeding grey seals

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    Understanding the habitat requirements of a species for breeding is essential for its conservation, particularly if the availability of suitable habitat is a limiting factor for population growth. This is postulated to be the case for grey seals, one of the more abundant marine apex predators in northern European waters. In common with similar studies that have investigated the habitat preferences of breeding grey seals, we use abiotic (topographical, climatological) attributes but, unlike previous work, we also incorporate behavioural variables, particularly the occurrence of aggressive interactions between females and the presence of neighbouring seals. We used two Generalized Additive Models (GAM) in a sequential and iterative fashion. The first model links the occurrence of aggression at particular points in the colony to local topography derived from a Geographical Information System (GIS), presence of neighbouring seal pups and the day of the breeding season. The output of this GAM is used as one of the explanatory variables in a GAM of daily variation in the spatial distribution of births. Although proximity of a birth site to a water source and the presence of neighbouring seal pups both had significant influences on the distribution of newborn pups over time and space, at the scale of the study site it was found that simple rules could predict pup distribution more efficiently than a complex individual-based simulation model

    An early Permian brachiopod–gastropod fauna from the Calytrix Formation, Barbwire Terrace, Canning Basin, Western Australia

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    A small brachiopod–gastropod fauna from a core close to the base of the Calytrix Formation within the Grant Group includes the brachiopods Altiplecus decipiens (Hosking), Myodelthyrium dickinsi (Thomas), Brachythyrinella narsarhensis (Reed), Neochonetes (Sommeriella) obrieni Archbold, Tivertonia barbwirensis sp. nov. and the gastropod Peruvispira canningensis sp. nov. The fauna has affinities with that of the late Sakmarian‒early Artinskian Nura Nura Member directly overlying the Grant Group in other parts of the basin but, as with all lower Cisuralian (and Pennsylvanian) glacial strata in Western Australia, its precise age remains poorly constrained, especially in terms of correlation to international stages. Although the Calytrix fauna lies within the Pseudoreticulatispora confluens Palynozone, the only real constraint on its age (and that of the associated glacially influenced strata) is from Sakmarian (Sterlitamakian) and stratigraphically younger faunas. A brief review of radiometric ages from correlative strata elsewhere in Gondwana shows that those ages need to be updated. The presence of Asselian strata and the position of the Carboniferous‒Permian boundary remain unclear in Western Australia.Arturo César Taboada [[email protected]], CONICET-Laboratorio de Investigaciones en Evolución y Biodiversidad (LIEB), Facultad de Ciencias Naturales, Sede Esquel, Universidad Nacional de la Patagonia ‘San Juan Bosco’, Edificio de Aulas, Ruta Nacional 259, km. 16,5, Esquel U9200, Chubut, Argentina; Arthur Mory [[email protected]], Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, School of Earth and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Guang R. Shi [[email protected]], School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia; David W. Haig [[email protected]], School of Earth and Environment (M004), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; María Karina Pinilla [[email protected]], División Paleozoología Invertebrados, Museo de Ciencias Naturales de La Plata, Paseo del Bosque s/n, 1900 La Plata, Buenos Aires, Argentina
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