1,739 research outputs found

    Fault identification using multidisciplinary techniques at the Mars/Uranus Station antenna sites

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    A fault investigation was performed at the Mars and Uranus antenna sites at the Goldstone Deep Space Communications Complex in the Mojave desert. The Mars/Uranus Station consists of two large-diameter reflector antennas used for communication and control of deep-space probes and other missions. The investigation included interpretation of Landsat thematic mapper scenes, side-looking airborne radar transparencies, and both color-infrared and black-and-white aerial photography. Four photolineaments suggestive of previously undocumented faults were identified. Three generally discrete morphostratigraphic alluvial-fan deposits were also recognized and dated using geomorphic and soil stratigraphic techniques. Fourteen trenches were excavated across the four lineaments; the trenches show that three of the photolineaments coincide with faults. The last displacement of two of the faults occurred between about 12,000 and 35,000 years ago. The third fault was judged to be older than 12,000 years before present (ybp), although uncertainty remains. None of the surface traces of the three faults crosses under existing antennas or structures; however, their potential activity necessitates appropriate seismic retrofit designs and loss-prevention measures to mitigate potential earthquake damage to facilities and structures

    A national multiple baseline cohort study of mental health conditions in early adolescence and subsequent educational outcomes in New Zealand

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    Young people experiencing mental health conditions are vulnerable to poorer educational outcomes for many reasons, including: social exclusion, stigma, and limited in-school support. Using a near-complete New Zealand population administrative database, this prospective cohort study aimed to quantify differences in educational attainment (at ages 15-16 years) and school suspensions (over ages 13-16 years), between those with and without a prior mental health condition. The data included five student cohorts, each starting secondary school from 2013 to 2017 respectively (N=272,901). Both internalising and externalising mental health conditions were examined. Overall, 6.8% had a mental health condition. Using adjusted modified Poisson regression analyses, those with prior mental health conditions exhibited lower rates of attainment (IRR=0.87, 95% CI 0.86-0.88) and higher rates of school suspensions (IRR=1.63, 95% CI 1.57-1.70) by age 15-16 years. Associations were stronger among those exhibiting behavioural conditions, compared to emotional conditions, in line with previous literature. These findings highlight the importance of support for young people experiencing mental health conditions at this crucial juncture in their educational pathway. While mental health conditions increase the likelihood of poorer educational outcomes, deleterious outcomes were not a necessary sequalae. In this study, most participants with mental health conditions had successful educational outcomes

    The island–mainland species turnover relationship

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    Many oceanic islands are notable for their high endemism, suggesting that islands may promote unique assembly processes. However, mainland assemblages sometimes harbour comparable levels of endemism, suggesting that island biotas may not be as unique as is often assumed. Here, we test the uniqueness of island biotic assembly by comparing the rate of species turnover among islands and the mainland, after accounting for distance decay and environmental gradients. We modelled species turnover as a function of geographical and environmental distance for mainland (M–M) communities of Anolis lizards and Terrarana frogs, two clades that have diversified extensively on Caribbean islands and the mainland Neotropics. We compared mainland–island (M–I) and island–island (I–I) species turnover with predictions of the M–M model. If island assembly is not unique, then the M–M model should successfully predict M–I and I–I turnover, given geographical and environmental distance. We found that M–I turnover and, to a lesser extent, I–I turnover were significantly higher than predicted for both clades. Thus, in the first quantitative comparison of mainland–island species turnover, we confirm the long-held but untested assumption that island assemblages accumulate biodiversity differently than their mainland counterparts

    Designing robust and reliable timestamps for remote patient monitoring

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    This article has been made available through the Brunel Open Access Publishing Fund.Having timestamps that are robust and reliable is essential for remote patient monitoring in order for patient data to have context and to be correlated with other data. However, unlike hospital systems for which guidelines on timestamps are currently provided by HL7 and IHE, remote patient monitoring platforms are: operated in environments where it can be difficult to synchronize with reliable time sources; include devices with simple or no clock; and may store data spanning significant periods before able to upload. Existing guidelines prove inadequate. This paper analyses the requirements and the operating scenarios of remote patient monitoring platforms and defines a framework to convey information on the conditions under which observations were made by the device and forwarded by the gateway in order for data to be managed appropriately and to include both reference to local time and an underlying continuous reference timeline. We define the timestamp formats of HL7 to denote the different conditions of operation and describe extensions to the existing definition of the HL7 timestamp to differentiate between time local to GMT (+0000) and UTC or NTP time where no geographic time zone is implied (-0000). We further describe how timestamps from devices having only simple or no clocks might be managed reliably by a gateway to provide timestamps that are referenced to local time and an underlying continuous reference timeline. We extend the HL7 message to include information to permit a subsequent receiver of the data to understand the quality of the timestamp and how it has been translated. We present evaluation from deploying a platform for 12 months

    Electronic interactions in fullerene spheres

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    The electron-phonon and Coulomb interactions inC60_{60}, and larger fullerene spheres are analyzed. The coupling between electrons and intramolecular vibrations give corrections 110\sim 1 - 10 meV to the electronic energies for C60_{60}, and scales as R4R^{-4} in larger molecules. The energies associated with electrostatic interactions are of order 14\sim 1 - 4 eV, in C60_{60} and scale as R1R^{-1}. Charged fullerenes show enhanced electron-phonon coupling, 10\sim 10 meV, which scales as R2R^{-2}. Finally, it is argued that non only C60_{60}^{-}, but also C60_{60}^{--} are highly polarizable molecules. The polarizabilities scale as R3R^3 and R4R^4, respectively. The role of this large polarizability in mediating intermolecular interactions is also discussed.Comment: 12 pages. No figure

    Crater lake cichlids individually specialize along the benthic-limnetic axis

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    A common pattern of adaptive diversification in freshwater fishes is the repeated evolution of elongated open water (limnetic) species and high-bodied shore (benthic) species from generalist ancestors. Studies on phenotype-diet correlations have suggested that population-wide individual specialization occurs at an early evolutionary and ecological stage of divergence and niche partitioning. This variable restricted niche use across individuals can provide the raw material for earliest stages of sympatric divergence. We investigated variation in morphology and diet as well as their correlations along the benthic-limnetic axis in an extremely young Midas cichlid species, Amphilophus tolteca, endemic to the Nicaraguan crater lake Asososca Managua. We found that A. tolteca varied continuously in ecologically relevant traits such as body shape and lower pharyngeal jaw morphology. The correlation of these phenotypes with niche suggested that individuals are specialized along the benthic-limnetic axis. No genetic differentiation within the crater lake was detected based on genotypes from 13 microsatellite loci. Overall, we found that individual specialization in this young crater lake species encompasses the limnetic- as well as the benthic macro-habitat. Yet there is no evidence for any diversification within the species, making this a candidate system for studying what might be the early stages preceding sympatric divergence

    Polio Outbreak Response in Ethiopia

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    Background: Ethiopia had been polio-free for almost four years until December 2004. However, between December 2004 and February 2006, 24 children were paralysed as a result of infection with wild poliovirus imported from the neighbouring country of Sudan. In response, the country has attempted to document the impact of various response measures on the containment of wild poliovirus transmission. Objectives: This study aims at systematic and epidemiological assessment of the extent of the outbreak, its determinants, and the lessons learned as well as the implications for future control strategies to interrupt wild poliovirus transmission. Design: A cross-sectional study design with qualitative and quantitative data collection approaches was used to conduct the epidemiologic assessment. Subjects: All confirmed wild poliovirus cases, and reported acute flaccid paralysis cases in close proximity to the confirmed polio cases were the study subjects. Child caretakers and health service providers were interviewed as part of the investigation. Results: Between December 2004 and February 2006, eight children from Tigray Regional State, nine children from Amhara Regional State and seven children from Oromia Regional State were paralysed as a result of infection with wild poliovirus type 1. Genetic sequencing demonstrated two separate importations to Ethiopia. Risk factors that may have facilitated spread of the outbreak within the country included gaps in vaccination coverage and interruption of the cold chain system, gaps in acute flaccid paralysis surveillance performance, high population mobility, poor environmental sanitation, crowded living conditions and unsafe drinking water. In response to the outbreak, Ethiopia conducted detailed outbreak investigations within two days of confirmation of the index cases. Large-scale, house-to-house vaccination campaigns were also implemented. As a result, the three regions interrupted the wild poliovirus transmission within the regions within one year of confirmation of the index case. Conclusion: Outbreak response activities were successful in interrupting the imported wild poliovirus transmission in Tigray, Amhara and Oromia Regional States of Ethiopia within a oneyear period of time. In Ethiopia, programme strategies should be intensified to contain further spread and prevent future importation of wild poliovirus. Large-scale immunisation campaigns should reach every child, including those isolated by geography, poverty and security. East African Medical Journla Vol. 85 (5) 2008: pp. 222-23

    The Lorentz force in atmospheres of CP stars: θ\theta Aurigae

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    Several dynamical processes may induce considerable electric currents in the atmospheres of magnetic chemically peculiar (CP) stars. The Lorentz force, which results from the interaction between the magnetic field and the induced currents, modifies the atmospheric structure and induces characteristic rotational variability of the hydrogen Balmer lines. To study this phenomena we have initiated a systematic spectroscopic survey of the Balmer lines variation in magnetic CP stars. In this paper we continue presentation of results of the program focusing on the high-resolution spectral observations of A0p star \aur (HD 40312). We have detected a significant variability of the Hα\alpha, Hβ\beta, and Hγ\gamma spectral lines during full rotation cycle of the star. This variability is interpreted in the framework of the model atmosphere analysis, which accounts for the Lorentz force effects. Both the inward and outward directed Lorentz forces are considered under the assumption of the axisymmetric dipole or dipole+quadrupole magnetic field configurations. We demonstrate that only the model with the outward directed Lorentz force in the dipole+quadrupole configuration is able to reproduce the observed hydrogen line variation. These results present new strong evidences for the presence of non-zero global electric currents in the atmosphere of an early-type magnetic star.Comment: 10 figure
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