Life after extinction: palaeoenvironments of the earliest Triassic lower Katberg formation, including the origin of Lystrosaurus Bonebeds from the Karoo Basin, South Africa

Includes abstract.Includes bibliographical references.This study argues for the formation of bonebeds by aggregation of sub-adult Lystrosaurus during extended episodic periods of extreme climatic conditions, such as cold or drought, in the earliest Triassic Karoo Basin

Estimation of Iron Bioavailability from the Diets of an Adolescent Population

Estimation of dietary iron bioavailability and determination of dietary iron intake were evaluated from 24-hour food records of 224 adolescents in eastern Tennessee. Total daily iron intakes, 16.1 mg for males and 11.1 mg for females, were below the Recommended Dietary Allowances (RDA). Application of the Monsen and Balintfy model to estimate iron bioavailability showed that absorbable iron from males\u27 diets, 1.38 mg, and from females\u27 diets, 0.91 mg, was below recommended levels. Percentages of bioavailable iron were below the assumed 10% absorption level,a criterion used in establishing the RDA for iron. Thus, total dietary iron was inadequate for males and females as indicated by both measures. Patterns of iron bioavailability differed among eating occasions but were similar for males and females. Although intakes of the enhancing factor, ascorbic acid, were high at breakfast, the meal was lowest in total iron, percentages of bioavailable iron, and amounts of absorbable iron compared with other meals. The nutrient density of ascorbic acid and iron of lunch meals of adolescents did not meet recommended levels, but more meat, fish, and poultry foods were consumed at lunch than at breakfast. In comparison to other meals, evening meal patterns were highest in meat, fish, and poultry; total iron; total amounts of enhancing factors; amounts of absorbable iron; and percentages of bioavailable iron. Dietary patterns of adolescent males at the evening meal approached desirable patterns to maximize iron bioavailability. Intakes of iron and absorbable amounts of iron in adolescent females\u27 diets were less than in males\u27 diets and were inadequate. Snacks, which were consumed frequently by adolescents, contributed substantial amounts of food energy but were low in total iron, absorbable iron, and bioavailable iron. The inclusion of ascorbic acid sources and animal tissue foods, enhancers of iron bioavailability, were low in snacks. Further evaluation of dietary patterns of adolescents shows that some males and females exhibited patterns that contributed to desirable levels of absorbable iron. Ascorbic acid and meat, fish, and poultry foods were high in their diets. Mean iron intakes of adolescent males and females in this group exceeded or approached the RDA. Adolescents whose iron intakes were inadequate may not be able to significantly improve iron adequacy through enhancement of iron absorption. They need to increase consumption of iron as well as enhancing factors. Application of the model to estimate iron bioavailability was useful in identifying patterns contributing to iron bioavailability

Stratigraphy and sedimentary environments of the Late Permian Dicynodon Assemblage Zone (Karoo Supergroup, South Africa) and implications for basin development

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in fulfilment of the requirements for the degree of Doctor of Philosophy. June 2016.The Dicynodon Assemblage Zone (DiAZ) spans the last three million years of the Late Permian (Lopingian) Beaufort Group (Karoo Supergroup). Fluvio-lacustrine conditions covered the entire Karoo Basin during this period, preserved as the rocks of the Balfour, Teekloof, and Normandien formations. However widely separated exposures and few dateable horizons make correlating between lithostratigraphic subdivisions difficult. Here a revised litho- and biostratigraphic framework is provided for the Upper Permian DiAZ. The Balfour Formation’s Barberskrans Member (BM) is renamed due to identifying the Oudeberg Member and not the BM at the current type locality (Barberskrans Cliffs). It is renamed Ripplemead member (RM) after Ripplemead farm 20 km north of Nieu Bethesda where it outcrops. The Teekloof Formation’s Javanerskop member and Musgrave Grit unit in the central Free State Province are regarded mappable units whereas the Boomplaas sandstone (BS) may represent a unit that is a lateral equivalent to the Oudeberg Member. Palaeontological and detrital zircon data suggest none of these locally persistent sandstone horizons correlate temporally. Three index fossils that currently define the DiAZ (Dicynodon lacerticeps, Theriognathus microps, and Procynosuchus delaharpeae) appear below its lower boundary and disappear below the Permo-Triassic Boundary (PTB), coincidentally with the appearance of Lystrosaurus maccaigi. The base of the DiAZ is redefined, with the revived Daptocephalus leoniceps and T. microps re-established as the index fossil for the newly proposed Daptocephalus Assemblage Zone (DaAZ), and is subdivided into two subzones. Da. leoniceps and T. microps’ appearance define the lower and L. maccaigi defines the base of the upper subzone. The same patterns of disappearance are observed at the same stratigraphic interval throughout the basin, despite the thinning of strata northward. Additionally wetter floodplain conditions prevailed in the Lower DaAZ than in the Upper DaAZ which likely reflects climatic changes associated with the Permo-Triassic mass extinction (PTME). Palaeocurrent and detrital zircon data demonstrate a southerly source area, and recycled orogen petrography indicates the Cape Supergroup is the source of Upper Permian strata. Dominant late Permian zircon population supports the foreland nature of the Karoo Basin. Orogenic loading/unloading events are identified by two fining-upward cycles, separated by a diachronous third-order subaerial unconformity at the base of the RM and Javanerskop members. Sediment progradation northwards was out-of-phase with the south and wedge-shaped. Distributive fluvial systems depositing sediment within a retroarc foreland basin best explains these observations. Lithostratigraphic beds and members are recommended for use as local marker horizons only in conjunction with other proxies, such as index fossils or radiometric dates in future studies.LG201

Free vibration analysis of locally damaged aerospace tapered composite structures using component-wise models

This work presents the free vibration analysis of tapered aircraft structures made of composite and metallic materials, with reference to global and local damage. A refined one-dimensional model, developed in the framework of the Carrera Unified Formulation, has been used to provide a detailed description of structures. Multi-component aeronautical structures have been modeled adopting Lagrange polynomials to evaluate the displacement field over the cross-section. Each component has been described through the component-wise approach, with its own geometrical and mechanical characteristics. The effects of localized damage have been investigated, thanks to the accuracy of the layer-wise models adopted. The model has been assessed by comparing the results with classical FE models. The results show that the present approach provides an accurate solution for the free vibration analyses of complex structures and is able to predict the consequences of a global or local failure of a structural component. The computational efficiency and the accuracy of the model used in this work can be exploited to characterize the dynamic response of complex composite structures considering a large number of damage configurations

Free vibration analysis of variable angle-tow composite wing structures

This paper investigates the possibility to improve the dynamic response of complex aeronautical structures using variable angle-tow composites. The study has been performed using an innovative numerical approach developed in the framework of the Carrera Unified Formulation able to study laminates with curvilinear fibres whose trajectories can be arbitrarily defined. Refined kinematic structural models have been used to deal with the complex behaviour of such structures. Several cases have been investigated in order to validate this approach and the results have been compared with those from classical modelling approaches. Simple beam models and complex wing structures, have been considered. The effects of different fibres-paths have also been studied and compared. The results confirm that an appropriate tow lay-up can be used to improve the performances of wing structures, i.e. innovative design solutions can be achieved

Carmelo Bene

Un’analisi dell’opera di Carmelo Bene attraverso un idea autobiografica che collega tutto il percosrso artistico, da Nostra Signora dei Turchi al ‘l mal de’ fiori. Ricostruisce un corpo alle opere che frequenta, come per il dottor Frankenstein le sue creazioni tendono a rompere gli equilibri costituiti. I personaggi universali come Amleto, Pinocchio, Macbeth, Achille, Adelchi e Aligi sono anti-eroi per eccellenza, vincolati ad un ideale altro e idealmente alto che Carmelo Bene non gli riconosce mai