Cambrian of Ireland

As discussed in Chapter 11 of this Report, some authors have considered that the uppermost part of the Southern Highland Group of the Dalradian in Scotland might be Lower Palaeozoic, possibly Early Cambrian to Early Ordovician. The age of the Irish Dalradian is also not fully clear (Daly 2001). Thus, in Ireland, strata that are clearly Cambrian in age are restricted in outcrop, being confined to some areas of the southeast (Fig. 16) in the Leinster Terrane (Murphy et al. 1991; Woodcock 2000; Holland 2001, 2009). There they comprise the Bray and Cahore Groups and part of the Lower Palaeozoic Ribband Group (Figs 18, 19). In addition, in southernmost Leinster (Fig. 20), palynological studies have now shown that the Cullenstown Formation is Cambrian. In the same area, the Ballycogly Group mylonites, which occur along the boundary between the Leinster Terrane and the Precambrian basement of the Rosslare Terrane, are considered to be Cambrian (Tietzsch-Tyler & Sleeman 1994a) although there is no direct biostratigraphical evidence

The contrasting relationships between betaine and homocysteine in two clinical cohorts are associated with plasma lipids and drug treatments

10.1371/journal.pone.0032460PLoS ONE73e3246

Ganymede’s tenous atmosphere

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Isolating auroral FUV emission lines using compact, broadband instrumentation

Images of auroral emissions at far ultraviolet (FUV, 122–200 nm) wavelengths are useful tools with which to study magnetospheric-ionospheric coupling, as the scattered sunlight background in this region is low, allowing both dayside and nightside auroras to be imaged simultaneously. The ratio of intensities between certain FUV emission lines or regions can be used to characterise the precipitating particles responsible for auroral emissions, and hence is a useful diagnostic of magnetospheric dynamics. Here, we describe how the addition of simple transmission filters to a compact broadband imager design allows far ultraviolet emission ratios to be deduced while also providing large-scale instantaneous images of the aurora. The low mass and volume of such an instrument would make it well-suited for both small satellite Earth-orbiting missions and larger outer planet missions from which it could be used to characterise the tenuous atmospheres observed at several moons, as well as studying the auroral emissions of the gas giants. We present a study to investigate the accuracy of a technique to allow emission line ratio retrieval, as applied to the OI 130.4 nm and 135.6 nm emissions at Ganymede. The ratio of these emissions provides information about the atmospheric composition, specifically the relative abundances of O and O2. Using modelled FUV spectra representative of Ganymede's atmosphere, based on observations by the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS), we find that the accuracy of the retrieved ratios is a function of the magnitude of the ratio, with the best measurements corresponding to a ratio of ∼1.3

Ganymede’s tenous atmosphere

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