4,353 research outputs found

    Macrofossils as indicators of Plio-Pleistocene climates in Tasmania and Antarctica

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    Plant macrofossils can be used as proxy palaeoclimatic indicators, since both the taxa present at a site and the form ofleaves depend on the climate, and macrofossils are rarely transported far. In the simple case of the Sirius Group Nothofagus leaves and wood in Antarctica, the fossils provide data on climate that suggest temperatures at the time of deposition were in the order of> 10°C warmer than at present. While the age of the fossils is still debated, the climatic signal is not. However, in more subtle cases, where the climatic differences are smaller and the fossil evidence is more complex, it is critical to interpret the evidence cauriously. Macrofossils from Pleistocene localities in Tasmania provide a clear signal on temperature and rainfall that is sometimes at odds with pollen-based reconstructions, bur the former is inherently likely to be more accurate

    The macrofossil record of Proteaceae in Tasmania: a review with new species

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    About ten taxa of Proteaceae are known from the Early Eocene in Tasmania, one from a Late Eocene site, 22 from four Early Oligocene sites, one from a Late Oligocene/Early Miocene site, 12 or 13 from two Early Pleistocene sites, and five or six from the Middle and Late Pleistocene. Most of the Tertiary fossils are of extinct species, but the extant species Lomatia fraxinifolia and Telopea truncata have been recorded from the Early Oligocene as well as apparent close relatives of the subalpine rainforest species Orites milliganii, and the sub-tropical rainforest species, O. excelsa. None of the Early Oligocene species are known from more than one site, implying very high regional diversity, and floristic differentiation among the sites. High diversity of Proteaceae at some sites may be associated with oligotrophic soils. There is no evidence of any of the modern species-rich scleromorphic groups of Proteaceae except Banksiinae. Scleromorphy was well established in Oriteae, Embothrieae and Banksiinae by the Early Oligocene. The Early Eocene fossils have very small stomata, sparsely distributed on the leaf, which may have been due to elevated atmospheric CO2. All extant Tasmanian genera and many extant species were present by the Early Pleistocene as well as some extinct species. The specific diversity within the region was probably higher than it is now. In order to resolve a nomenclatural problem with the genus Proteaciphyllum, Euproteaciphyllum G.J.Jord., R.J.Carp. & R.S.Hill, gen. nov. is proposed and this name is applied to 10 previously described species. The Tasmanian fossil taxa include three new records, and nine new species: Euproteaciphyllum brookerensis G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., and E. tasmanicum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov. from Early Eocene sediments; and Orites milliganoides G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., O. scleromorpha G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. papillosum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. polymorphum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. microlobium G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. falcatum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., and E. serratum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov. from Early Oligocene sediments

    Telling the tale of the first stars

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    HE 0107-5240 is a star in more than once sense of the word. Chemically, it is the most primitive object yet discovered, and it is at the centre of debate about the origins of the first elements in the Universe.Comment: 3 pages, 0 figures, published in Nature "News and Views," Apr. 24, 200

    Time-motion characteristics and physiological responses of small-sided games in elite youth players: The influence of player number and rule changes

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    The aim of this study was to examine acute physiological responses and time-motion characteristics associated with 4 soccer-specific small-sided game (SSG) formats (3 vs. 4 players, 3 vs. 3 players + floater, 5 vs. 6 players, and 5 vs. 5 players + floater) and 4 rule changes in elite youth soccer players. Sixteen male youth soccer players (mean ± SD: age = 15.6 ± 0.8 years, stature = 170.8 ± 6.6 cm, body mass = 67.5 ± 6.2 kg, and 20-m shuttle run estimated V̇2 max = 57.4 ± 3.7 ml·kg-1-min-1) participated in the study, in which heart rate (HR), rating of perceived exertion (RPE), blood lactate (La -), and time-motion characteristics were recorded. The rule change requiring extra sprint running had a greater effect on the time-motion characteristics than all other rule modifications but no effect on acute %HRmax, La-, and RPE. Rule changes had no effect on RPE. Fixed underload teams (i.e., lower number of players compared with the opponent team) recorded a significantly higher RPE compared with the fixed overload teams, although there were no differences in %HRmax and La-. The major practical findings are that subtle changes in SSGs playing rules can influence the physiological, perceptual, and time-motion responses in young elite soccer players. Rules that are related to a team's chances of scoring may improve player motivation and thereby increase training intensity during SSGs. There were no differences between fixed and variable formats in terms of physiological and perceptual responses, although both may provide useful technical-tactical training. Coaches should take care in designing different soccer SSGs as each rule or game format change may influence exercise intensity independently. © 2010 National Strength and Conditioning Association

    Shoreline and Bathymetry Approximation in Mesh Generation for Tidal Renewable Simulations

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    Due to the fractal nature of the domain geometry in geophysical flow simulations, a completely accurate description of the domain in terms of a computational mesh is frequently deemed infeasible. Shoreline and bathymetry simplification methods are used to remove small scale details in the geometry, particularly in areas away from the region of interest. To that end, a novel method for shoreline and bathymetry simplification is presented. Existing shoreline simplification methods typically remove points if the resultant geometry satisfies particular geometric criteria. Bathymetry is usually simplified using traditional filtering techniques, that remove unwanted Fourier modes. Principal Component Analysis (PCA) has been used in other fields to isolate small-scale structures from larger scale coherent features in a robust way, underpinned by a rigorous but simple mathematical framework. Here we present a method based on principal component analysis aimed towards simplification of shorelines and bathymetry. We present the algorithm in detail and show simplified shorelines and bathymetry in the wider region around the North Sea. Finally, the methods are used in the context of unstructured mesh generation aimed at tidal resource assessment simulations in the coastal regions around the UK

    Nutritional status of cancer patients in chemotherapy; dietary intake, nitrogen balance and screening

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldOBJECTIVE: To evaluate a short screening sheet (SSM) for malnutrition and to investigate the nutritional status of patients receiving chemotherapy for cancer of the lungs, colon or breast at an outpatient clinic. DESIGN: Full nutritional assessment was conducted to define malnutrition and validate the SSM. Additionally, weight change from earlier healthy weight was evaluated, and calculations for intake of energy-giving nutrients (three-day-weighed food records) and protein balance were performed. After the evaluation study, the SSM was tested in clinical routine and data collected about patients' need for nutritional counseling. SUBJECTS: Patients at the outpatient clinic of the Department of Oncology at Landspitali-University Hospital (n=30 with lung-, colon- or breast cancer in the study population, n=93 with all cancer type in clinical routine screening). RESULTS: Malnutrition was defined by full nutritional assessment in 20% of the participating patients and SSM had high sensitivity and specificity. Declining nutritional status of the patients was seen as a negative nitrogen balance and unintentional weight loss from healthy weight, but not as total energy intake, recent weight loss or underweight. The test of SSM in clinical routine showed that 40% were malnourished. According to the patients, 80% needed nutritional counseling but only 17% had such counseling. CONCLUSION: Screening (SSM) for malnutrition in cancer patients is a valid simple approach to define cancer patients for nutritional care. More patients regard themselves in need for nutritional counseling than the number of patients really achieving any

    Climate change education for universities: a conceptual framework from an international study

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    The role of universities in climate change education (CCE) is of great importance if the scientific, social, environmental and political challenges the world faces are to be met. Future leaders must make decisions from an informed position and the public will need to embed climate change mitigation tools into their work and private life. It is therefore essential to understand the range of CCE strategies being taken globally by Higher Education Institutions (HEIs) and to explore and analyse the ways that HEIs could better address this challenge. Consistent with this research need, this paper offers an analysis of the extent to which HEIs in 45 countries approach CCE and provides a conceptual framework for exploring how HEIs are embedding CCE into their curricula. In addition to the specialist approach (where students choose to study a degree to become experts in climate change adaptation and mitigation tools), the CCE framework developed identifies and highlights three other approaches HEIs can deploy to embed CCE: Piggybacking, mainstreaming and connecting (transdisciplinary). Using data gathered in an explorative international survey involving participants working across academic and senior management, this paper illustrates the different approaches taken and analyses practical examples of current CCE practice from across the world. Responses from 212 university staff from 45 countries indicated that CCE was highly variable – no clear pattern was identified at the country level, with CCE approaches varying significantly, even within individual HEIs. This plurality highlights the wide range of ideas and examples being shared and used by institutions in very different countries and contexts, and underlines the importance of the independence and autonomy of HEIs so that they can choose the right CCE approaches for them. To highlight the breadth and variety of approaches that were uncovered by our survey, the paper offers a range of examples illustrating how climate change education may be embedded in a higher education context, some of which could be replicated in HEIs across the world. The conceptualisation of CCE and the examples given in this paper are valuable for anyone who is thinking about strategies for embedding more climate education in the higher education curriculum

    New macrofossils of the Australian cycad bowenia and their significance in reconstructing the past morphological range of the genus

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    Premise of research:This study describes a new fossil species of Bowenia and reconsiders known fossil species and their evolutionary significance.Methodology:The fossils we describe here were collected for this study or were available from previous collections made over several decades. The fossils were identified by direct comparisons with extant and fossil species.Pivotal results:A reexamination of known and newly discovered Bowenia macrofossils confirms the presence of at least three fossil species in Australia. A new species, Bowenia johnsonii, is described from the southernmost location, the Early Eocene Lowana Road site in southwest Tasmania. When compared with the two extant species, the three fossil species demonstrate two distinct pinnule morphologies: relatively small with distinct serrations in Bowenia eocenica and Bowenia papillosa and larger pinnules with minute serrations in B. johnsonii. When considered together, the stomata of the extant species are denser and larger than those of the fossil taxa.Conclusions:The cycad genus Bowenia has a restricted extant distribution along the east coast of Queensland but is known more widely within Australia from fossils. The fossil record of Bowenia is important in documenting the past distribution of this genus, and aspects of its pinnule morphology provide insights into its environmental interactions. The possible relationship of the fossil Bowenia species with the Aptian Argentinian genus Eobowenia is considered, along with some fragmentary Australian fossils of probable Bowenia
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