136 research outputs found

    Caledonian and Knoydartian overprinting of a Grenvillian inlier and the enclosing Morar Group rocks: structural evolution of the Precambrian Proto-Moine Nappe, Glenelg, NW Scotland

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    The Grenville and Caledonian orogens, fundamental to building Laurentia and Baltica, intersect in northern Scotland. The Precambrian Glenelg Inlier, within the Scottish Caledonides, preserves a record of Grenvillian, Knoydartian and Caledonian orogenesis. Based on new mapping and re-interpretation of previous mapping, we present a structural model for the evolution of the Glenelg Inlier. The inlier can be divided into Western Glenelg gneiss comprising orthogneiss with no record of Grenville-age metamorphism, and Eastern Glenelg gneiss with ortho- and paragneiss, affected by Grenvillian eclogite-facies metamorphism. The basement gneisses and their original cover of psammitic, Neoproterozoic Morar Group (Moine) rocks were deformed by three generations of major ductile folds (F1–F3). In medium-strain areas F2 and F3 folds are broadly coaxial and both face to the west; in higher strain areas F2 and F3 folds are oblique to each other. By restoring post-F1 folds and late faults, the Glenelg gneiss inliers are seen to form the core of a major recumbent SSE-facing F1 isoclinal fold nappe – the Proto-Moine Nappe. The upper limb of this nappe is a thick, right-way-up sequence of moderately strained Morar Group rocks whereas the lower, inverted limb comprises intensely deformed, migmatitic Morar Group rocks. Within the constraints of published geochronology, the Proto-Moine Nappe is likely Pre-Caledonian and may have originated during the early Neoproterozoic Knoydartian Orogeny

    Hospitalization after Adolescent and Young Adult (AYA) Cancer: A population-based study in Utah

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    Background: Adolescents and young adults (AYA, age 15 39 years) with cancer may be at elevated risk for late morbidity following their cancer treatment, but few studies have quantified the excess burden of severe disease in this population. Using population-based data from Utah, we examined the risk of inpatient hospitalizations among AYA cancer survivors compared with their siblings and the general population. Methods: Survivors of AYA cancer who were 2 years from diagnosis and diagnosed from 1994 to 2015 (N 1/4 6,330), their siblings (N 1/4 12,924), and an age- and sex-matched comparison cohort (N 1/4 18,171) were identified using the Utah Population Database (UPDB). Hospitalizations from 1996 to 2017 were identified from statewide discharge records in the UPDB. We estimated multivariable-adjusted hazard ratios (HR) for first hospitalization and rate ratios (RR) for total hospitalizations for survivors relative to the matched comparison cohort and siblings. Results: Overall, the risk of a first hospitalization was higher among AYA cancer survivors than the matched populationbased cohort [HR 1/4 1.93; 95% confidence interval (CI), 1.81 2.06]. Risk was most elevated for survivors of leukemia (HR 1/4 4.76), central nervous system tumors (HR 1/4 3.45), colorectal cancers (HR 1/4 2.83), non-Hodgkin lymphoma (HR 1/4 2.76), and breast cancer (HR 1/4 2.37). The rate of total hospitalizations was also increased among survivors relative to the comparison cohort (RR 1/4 2.05; 95% CI, 1.95 2.14). Patterns were generally similar in analyses comparing survivors to their siblings. Conclusions: AYA cancer survivors have a higher burden of inpatient hospitalization than their siblings and the general population. Impact: Results indicate the importance of long-term, riskbased follow-up care to prevent and treat severe morbidities after cancer treatment

    A review of the fossil record of turtles of the clade Pan-Carettochelys

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    Turtles of the total clade Pan-Carettochelys have a relatively poor fossil record that extends from the Early Cretaceous. The clade is only found in Asia during the Cretaceous, but spreads to Europe and North America during the Eocene. Neogene finds are restricted to Europe, Africa and Australia, whereas the only surviving species, Carettochelys insculpta, lives in New Guinea and the Northern Territories of Australia. The ecology of fossil pan-carettochelyids appears similar to that of the extant C. insculpta, although more primitive representatives were likely less adapted to brackish water. Current phylogenies only recognize three internested clades: Pan- Carettochelys, Carettochelyidae and Carettochelyinae. A taxonomic review of the group concludes that of 25 named taxa, 13 are nomina valida, 7 are nomina invalida, 3 are nomina dubia, and 2 are nomina nuda

    A Welsh first

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    The Fforest Fawr (Great Forest) Geopark became the first Welsh Geopark and the 24th member of the European and Global Geopark Network at the annual meeting of the European Geopark Network (EGN) on the Greek island of Lesvos in October 2005. The status was achieved as a result of the concerted efforts of the Brecon Beacons National Park Authority, Cardiff University and the British Geological Survey. Representatives from these organisations put together the successful application and received contributions to the submission from the communities within the Geopar

    Embryo and seedling morphology in Trithuria lanterna (Hydatellaceae, Nymphaeales): new data for infrafamilial systematics and a novel type of syncotyly

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    Keywords: anatomy; cotyledon; embryology; evolution; gravitropism; heterocotyly; monocots; seed germination; vasculature The monogeneric early-divergent angiosperm family Hydatellaceae (Trithuria) was formerly placed in the monocots and shows several features that are at least superficially monocot-like. Seedlings of Hydatellaceae are unusually diverse and have been interpreted as either dicotylar or monocotylar. We provide the first detailed developmental description of seedlings of Trithuria lanterna (including the first data on mature embryos of tropical Hydatellaceae) as a basis for the general discussion of seedling diversity in Hydatellaceae. Seedlings at various stages after germination were studied using serial sections and scanning electron microscopy. The embryo is dicotylar. It lacks pronounced asymmetry and lacks a plumule before seed germination. In the majority of seedlings, the cotyledons are free and appear attached to the seedling axis at different levels. In other seedlings, the cotyledons are united via a non-haustorial leaf-like organ; this alternative condition represents a novel type of syncotyly for seed plants and a second type of syncotyly recorded for Hydatellaceae. Seedling morphology is determined by strong one-sided growth of the hypocotyl, which is an unusual way of overcoming the basic seed plant spatial constraint at germination. The direction of one-sided growth is independent of cotyledon orientation and could be environmentally determined. Seedlings provide synapomorphies for the two major clades of Trithuria, which can be regarded as subgenera. Although no direct homology is inferred, the exceptional degree of morphological variation in Hydatellaceae seedlings, including the variable occurrence of several superficially monocot-like features, leads us to hypothesize that the stem group of monocots could have exhibited an analogous degree of variation in cotyledon morphology. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 201
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