151 research outputs found
Asociación de cefalópodos y secuencias deposicionales en el Cenomaniense superior y Turoniense inferior de la Península Ibérica (España y Portugal)
The comparison and correlation of the biostratigraphic successions identified in the upper Cenomanian and lower Turonian of the Iberian Trough (IT, Spain) and the Western Portuguese Carbonate Platform (WPCP, Portugal) allows differentiating nine cephalopod assemblages (1 to 9), with notably different taxa, and two (3rd order) depositional sequences (A and B). Some of these main intervals can be divided in minor ones, such as assemblage 4 (in 41 and 42) and sequence B (in B1 and B2). Assemblages 1 to 3 are related with sequence A, and assemblage 4 to 9 with sequence B (specifically, 4 to 6 with B1, and 7 to 9 with B2). The analysis and interpretation of these biostratigraphic data allows us to infer certain palaeoecologic turnovers that happened in the studied basins, both with external origin or due to local tectonic and palaeogeographical changes. Though partially altered by hypoxic phenomena (especially the sequence B1, assemblage 4) and local tectonics (mainly in the WPCP), in each of these cycles there were events of extinction of the cephalopods from shallow environments and survival of those from pelagic or deep environments, of settling of new environments, and of adaptation to them caused, successively, by intervals of low, ascending and high sea-level.La comparación y correlación de las sucesiones bioestratigráficas identificadas en el Cenomaniense superior y Turoniense inferior del Surco Ibérico (IT, España) y la Plataforma Carbonatada Occidental Portuguesa (WPCP, Portugal) permiten diferenciar nueve asociaciones de cefalópodos (1 a 9), con taxones notablemente diferentes, y dos secuencias deposicionales principales (3er orden) (A y B). Algunos de estos intervalos principales pueden dividirse en secundarios, como la Asociación 4 (en 41 and 42) y la Secuencia B (en B1 y B2). Las asociaciones 1 a 3 pueden se pueden relacionar con la secuencia A, y la asociación 4 a 9 con la secuencia la B (concretamente, 4 a 6 con B1, y 7 a 9 con B2). El análisis y la interpretación de estos datos bioestratigráficos permiten deducir ciertos cambios paleoecológicos sucedidos en las cuencas estudiadas, tanto de origen externo como debidos a la tectónica local ó a cambios paleogeográficos. Aunque parcialmente alterados por fenómenos de hipoxia (especialmente la secuencia B1, asociación 4) y de tectónica local (principalmente en el WPCP), en cada uno de estos ciclos se produjeron fenómenos de extinción de los cefalópodos de medios someros y de supervivencia de los de ambientes pelágicos ó profundos, de colonización de nuevos espacios, y de adaptación a los mismos provocados, sucesivamente, por intervalos de nivel de mar bajo, ascendente y alto
Synchrotron X-ray microdiffraction to study dental structures in Cretaceous crocodylomorphs
Synchrotron radiation X-ray microdiffraction (SR-μXRD) has been applied for the first time as a fundamental method of analysis to unveil crocodilian teeth growth and development. Teeth from a fossil crocodylomorph from the Upper Cretaceous site of Lo Hueco (Spain) and a modern crocodylian from the living species Crocodylus niloticus have been analysed. Both samples have been studied through Polarized Light Microscopy, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy, Confocal Raman Spectroscopy, and SR-μXRD. Significant differences have been found in hydroxyapatite (HA) crystallite sizes and texture, and the evolution of these two features along teeth depth. The main differences observed in crystallite size are related to postdepositional processes and/or the environmental and functional pressures of teeth during crocodylomorph life, very different from that of the modern specimen. Regarding the crystalline texture in the tooth enamel, it can be linked to teeth functionality during crocodilian life, causing the directed growth of HA crystallites due to the mechanical stress to which they are subjectedThis work was funded by the projects PGC2018-099405-B-100 (Ministerio de Ciencia, Innovacion y Universidades); HAR2017- 82755-P, HAR2016-78036-P, HAR2016-74846-P, HAR2017-83004-P, CGL2015-66604, CGL2015-68363 and MAT2015-67593-P (Ministerio de Economía y Competitividad, Spain); and 201860E127 (CSIC
Concern and Risk Perception: Effects on Osteoprotective Behaviour
This study aimed to determine the effect that level of concern for osteoporosis, as well as self-perceived risk of osteoporosis and fracture, has on supplementation use, seeking medical advice, bone mineral density (BMD) testing, and antiosteoporosis medication (AOM) use. Study subjects were 1,095 female Australian participants of the Global Longitudinal study of Osteoporosis in Women (GLOW) untreated for osteoporosis at baseline. Study outcomes from self-administered questionnaires included calcium and vitamin D supplementation, self-reported seeking of medical advice regarding osteoporosis, BMD testing, and AOM use in the last 12 months at the late assessment. Logistic regression was used in the analysis. Concern significantly increased the likelihood of seeking medical advice and, however, had no significant impact on screening or treatment. Heightened self-perceived risks of osteoporosis and fracture both significantly increased the likelihood of seeking medical advice and BMD testing while elevated self-perceived risk of fracture increased AOM use. Supplementation use was not significantly associated with concern levels and risk perception. Concern and risk perceptions to osteoporosis and fracture were significantly associated with certain bone-protective behaviours. However, the disconnect between perceived osteoporosis risk and AOM use illustrates the need to emphasize the connection between osteoporosis and fracture in future education programs
Concern and Risk Perception: Effects on Osteoprotective Behaviour
This study aimed to determine the effect that level of concern for osteoporosis, as well as self-perceived risk of osteoporosis and fracture, has on supplementation use, seeking medical advice, bone mineral density (BMD) testing, and antiosteoporosis medication (AOM) use. Study subjects were 1,095 female Australian participants of the Global Longitudinal study of Osteoporosis in Women (GLOW) untreated for osteoporosis at baseline. Study outcomes from self-administered questionnaires included calcium and vitamin D supplementation, self-reported seeking of medical advice regarding osteoporosis, BMD testing, and AOM use in the last 12 months at the late assessment. Logistic regression was used in the analysis. Concern significantly increased the likelihood of seeking medical advice and, however, had no significant impact on screening or treatment. Heightened self-perceived risks of osteoporosis and fracture both significantly increased the likelihood of seeking medical advice and BMD testing while elevated selfperceived risk of fracture increased AOM use. Supplementation use was not significantly associated with concern levels and risk perception. Concern and risk perceptions to osteoporosis and fracture were significantly associated with certain bone-protective behaviours. However, the disconnect between perceived osteoporosis risk and AOM use illustrates the need to emphasize the connection between osteoporosis and fracture in future education programs
The Impact of Fracture Incidence on Health Related Quality of Life among Community-Based Postmenopausal Women
This prospective study aimed to examine the impact of fracture incidence on health-related quality of life (HRQOL) among postmenopausal women. Study subjects were Australian female community-dwellers in the Global Longitudinal Study of Osteoporosis in Women (GLOW). Self-administered questionnaires were collected annually from 2007 to 2010. Outcomes were the Medical Outcomes Study Short Form-36 (SF-36 physical function (SF36PFS) and vitality (SF36VS) scores), European Quality of Life (EQ-5D), and self-reported general health (GH) of excellent/good. Questionnaires were divided into prior to, the 1st, the 2nd, and the 3rd year after incident fracture assessments. Generalized linear models with generalised estimating equations (GEE) were employed for the analysis. The 2,872 participants (age: median 65; interquartile range 60-73 years) provided a total of 10,436 assessments including 266, 165 and 76 assessments for the 1st, the 2nd, and the 3rd year after incident fracture, respectively. Multivariate adjustments showed reductions in HRQOL measures peaking at the 1st year for SF36VS (coefficient −3.0; 95% CI: −5.1, −0.8) and EQ-5D (coefficient −0.03; 95% CI: −0.06, −0.00) and at the 2nd year for SF36PFS (coefficient −3.0; 95% CI: −5.6, −0.5) and GH (odds ratio 0.92; 95% CI: 0.70, 1.19). Fracture incidence reduced HRQOL including vitality and physical function among relatively young, healthy postmenopausal women and the reduction in European Quality of Life measure was clinically important
GOING DEEPER INTO MODERN AND FOSSIL CROCODILIAN TOOTH MICROANATOMY: WHAT CAN BE INFERRED OF PALAEOENVIRONMENT AND TAPHONOMY FROM HISTOCHEMICAL ANALYSES?
Teeth provide information about the evolutionary pathway of an organism, its biology and habitat. This is the case even of fossilized teeth, since they have perdurable biomineralized structures, as biological apatite. The material that has been selected for this study comprises teeth from modern crocodilian individuals and extinct Cretaceous crocodylomorphs from Lo Hueco site. Microanatomy, histochemistry and crystallographic nature of enamel, dentine and cementum have been characterized by Polarized Light Microscopy, SEM-EDS, Confocal Raman Spectroscopy and SR-µXRD. A focus has been made on dentine lamination. In the fossil sample short-period incremental lines show alternate presence of dentinal tubules that has not been described previously either in living or fossil archosaur. This could be related to influence of environmental circadian rhythms in the abundance, size and/or activity of cells depositing dentine in the day-night cycle. Regarding histochemical and crystallographic compositions, the major and mostly unique phase is HA, but in the case of fossil teeth, a secondary phase identified as hematite appears locally between discontinuities of the material. Incremental lines would not be related to variation in chemical composition and furthermore do not present different HA crystallographic nature (different directions of HA or different crystallite sizes) either. Only small intensity oscillations are observed in the fossil sample by SR-µXRD which are compatible with the alternating abundance of dentinal tubules. Crystallinity differences between modern and fossil material, as crystallite size and presence of CO32- groups could be explained by postdepositional processes.
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Comparative prebiotic activity of mixtures of cereal grain polysaccharides
The main components of the non-starch polysaccharide (NSP) fraction of wheat flour are arabinoxylan (AX) and β-glucan. These are also present in other cereal grains, but their proportions vary with AX being the major component in wheat and rye and β-glucan in barley and oats. Therefore, it was hypothesised that these NSPs could act synergistically when fermented in vitro at the ratios present in the major foods consumed, resulting in increased prebiotic activity. AX and β-glucan were therefore tested in in vitro fermentation studies to assess their prebiotic activity when used individually and/or in different ratios. Short-chain fatty-acids (SCFAs) produced from in vitro fermentation were measured using HPLC and bacterial populations were measured using flow cytometry with fluorescence in situ hybridisation (Flow-FISH). Fermentation of AX alone resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate, after 8-24 h of fermentation, however β-glucan alone did not show prebiotic activity. The greatest prebiotic activity, based on concentration of total SCFAs and increases in total bacteria as well as beneficial Bifidobacterium and Clostridium coccoides/Eubacterium groups, was observed when AX and β-glucan were combined at a 3:1 ratio, which corresponds to their ratios in wheat flour which is major source of cereal fibre in the diet. This indicates that the population of bacteria in the human GI tract may be modulated by the composition of the fibre in the diet, to maximise the prebiotic potential
Synchrotron X-ray microdiffraction to study dental structures in Cretaceous crocodylomorphs
Synchrotron radiation X-ray microdiffraction (SR-μXRD) has been applied for the first time as a fundamental method of analysis to unveil crocodilian teeth growth and development. Teeth from a fossil crocodylomorph from the Upper Cretaceous site of Lo Hueco (Spain) and a modern crocodylian from the living species Crocodylus niloticus have been analysed. Both samples have been studied through Polarized Light Microscopy, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy, Confocal Raman Spectroscopy, and SR-μXRD. Significant differences have been found in hydroxyapatite (HA) crystallite sizes and texture, and the evolution of these two features along teeth depth. The main differences observed in crystallite size are related to postdepositional processes and/or the environmental and functional pressures of teeth during crocodylomorph life, very different from that of the modern specimen. Regarding the crystalline texture in the tooth enamel, it can be linked to teeth functionality during crocodilian life, causing the directed growth of HA crystallites due to the mechanical stress to which they are subjected
The biota of the Upper Cretaceous site of Lo Hueco (Cuenca, Spain)
The Late Cretaceous (Campanian-Maastrichtian) fossil site of Lo Hueco was recently discovered close to the village of Fuentes (Cuenca,
Spain) during the cutting of a little hill for installation of the railway of the Madrid-Levante high-speed train. To date, it has yielded a rich
collection of well-preserved Cretaceous macrofossils, including plants, invertebrates, and vertebrates. The recovered fossil assemblage
is mainly composed of plants, molluscs (bivalves and gastropods), actinopterygians and teleosteans fishes, amphibians, panpleurodiran
(bothremydids) and pancryptodiran turtles, squamate lizards, eusuchian crocodyliforms, rhabdodontid ornithopods, theropods (mainly
dromaeosaurids), and titanosaur sauropods. This assemblage was deposited in a near-coast continental muddy floodplain crossed by distributary
sandy channels, exposed intermittently to brackish or marine and freshwater flooding as well as to partial or total desiccation events.The Konzentrat-Lagerstatt of Lo Hueco constitutes a singular accumulation of fossils representing individuals of some particular lineages
of continental tetrapods, especially titanosaurs, eusuchians and bothremydid turtles. In the case of the titanosaurs, the site has yielded
multiple partial skeletons in anatomical connection or with a low dispersion of their skeletal elements. A combination of new taxa, new
records of taxa previously known in the Iberian Peninsula, and relatively common taxa in the European record compose the Lo Hueco biota.
The particular conditions of the fossil site of Lo Hueco and the preliminary results indicate that the analysis of the geological context, the
floral and faunal content, and the taphonomical features of the site provide elements that will be especially useful for reassess the evolutionary
history of some lineages of European Late Cretaceous reptiles.Peer reviewe
Neurocranial osteology and neuroanatomy of a late Cretaceous Titanosaurian Sauropod from Spain (Ampelosaurus sp.)
Titanosaurians were a flourishing group of sauropod dinosaurs during Cretaceous times. Fossils of titanosaurians have been found on all continents and their remains are abundant in a number of Late Cretaceous sites. Nonetheless, the cranial anatomy of titanosaurians is still very poorly known. The Spanish latest Cretaceous locality of "Lo Hueco" yielded a relatively well preserved, titanosaurian braincase, which shares a number of phylogenetically restricted characters with Ampelosaurus atacis from France such as a flat occipital region. However, it appears to differ from A. atacis in some traits such as the greater degree of dorsoventral compression and the presence of proatlas facets. The specimen is, therefore, provisionally identified as Ampelosaurus sp. It was CT scanned, and 3D renderings of the cranial endocast and inner-ear system were generated. Our investigation highlights that, although titanosaurs were derived sauropods with a successful evolutionary history, they present a remarkably modest level of paleoneurological organization. Compared with the condition in the basal titanosauriform Giraffatitan brancai, the labyrinth of Ampelosaurus sp. shows a reduced morphology. The latter feature is possibly related to a restricted range of head-turning movementsThis is a contribution to the research project CGL2009-12143 (Ministerio de Economía y Competitividad, Madrid), of which FK, who is currently supported by the Ramón y Cajal Program, is Principal Investigator. LMW and RCR acknowledge funding support from the United States National Science Foundation (IBN-9601174, IBN-0343744, IOB-0517257, IOS-1050154) and the Ohio University Heritage College of Osteopathic Medicine. The Ohio Supercomputing Center also provided suppor
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