213 research outputs found

    The role of cyclic climatic regimes and riparian vegetation: a qualitative and quantitative study into the cause of river bank slope instability and channel widening on the Macdonald River, New South Wales.

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    Numerous case studies have demonstrated the catastrophic nature of channel change experienced on the Macdonald River, a tributary of the Hawkesbury-Nepean River, New South Wales. However, there is an absence of studies that clearly state how and why the channel changed as dramatically as it did. As a consequence, the magnitude of, and ultimate controls on the changes to the Macdonald River’s form and processes are not fully appreciated. In this study, a comparison is undertaken on the three existing river morphology perspectives with respect to the Macdonald River. The Warner and Erskine Perspective states the sole importance of the cyclic hydro-climatic conditions of the FDR and DDRs on river morphology. The Brierely and co-workers Perspective states the sole importance of anthropogenic influence in the catchment and on the banks on river morphology. The Intermediate Perspective of Hubble and co-workers considers both existing and conflicting perspectives and states the importance of both cyclic climatic regimes and anthropogenic activity in the catchment and particularly on the river banks, in determining river morphology. Resultantly, a selection of Hubble and co-workers Perspective is made to classify the Macdonald River’s morphology. It is clear, from the analysis of historical aerial photographs, archival sketches, photographs and historical documentation, that riparian vegetation was absent from the banks of the Macdonald River from 1941 as a result of land-clearing practices from the early 19th Century. The banks of the Macdonald River would not have experienced this ‘catastrophic’ channel change between 1949 and 1955 had riparian vegetation remained on the banks. Riparian vegetation has been found to increase the soil-shear strength and hence the stability of river bank slopes, in particularly on the Upper Nepean and the Macdonald Rivers in New South Wales, where vulnerable sands to silty-sands predominate the bank material. This has been further proved with geochemical bank stability modeling

    Hybrid and Interactive Domain-Specific Translation for Multilingual Access to Digital Libraries

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    Accurate high-coverage translation is a vital component of reliable cross language information retrieval (CLIR) systems. This is particularly true for retrieval from archives such as Digital Libraries which are often specific to certain domains. While general machine translation (MT) has been shown to be effective for CLIR tasks in laboratory information retrieval evaluation tasks, it is generally not well suited to specialized situations where domain-specific translations are required. We demonstrate that effective query translation in the domain of cultural heritage (CH) can be achieved using a hybrid translation method which augments a standard MT system with domain-specific phrase dictionaries automatically mined from Wikipedia. We further describe the use of these components in a domain-specific interactive query translation service. The interactive system selects the hybrid translation by default, with other possible translations being offered to the user interactively to enable them to select alternative or additional translation(s). The objective of this interactive service is to provide user control of translation while maximising translation accuracy and minimizing the translation effort of the user. Experiments using our hybrid translation system with sample query logs from users of CH websites demonstrate a large improvement in the accuracy of domain-specific phrase detection and translation

    Association of STAT4 with rheumatoid arthritis:A replication study in three European populations

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    OBJECTIVE: This study was undertaken to investigate the previously reported association of the STAT4 polymorphism rs7574865 with rheumatoid arthritis (RA) in 3 different European populations from Spain, Sweden, and The Netherlands, comprising a total of 2,072 patients and 2,474 controls. METHODS: Three different cohorts were included in the study: 923 RA patients and 1,296 healthy controls from Spain, 273 RA patients and 285 healthy controls from Sweden, and 876 RA patients and 893 healthy controls from The Netherlands. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the STAT4 single-nucleotide polymorphism rs7574865 using a TaqMan 5'-allele discrimination assay. The chi-square test was performed to compare allele and genotype distributions. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: We observed a significantly increased frequency of the minor T allele in RA patients compared with healthy controls in the Spanish population (24.8% versus 20.8%; P = 0.001, OR 1.26 [95% CI 1.09-1.45]). This association was confirmed in both the Swedish population (P = 0.03, OR 1.35 [95% CI 1.03-1.77]) and the Dutch population (P = 0.03, OR 1.45 [95% CI 1.21-1.73]). The overall P value for all 3 populations was 9.79 x 10(-6) (OR 1.25 [95% CI 1.13-1.37]). No association between rs7574865 and the presence of rheumatoid factor or anti-cyclic citrullinated peptide autoantibodies was observed. A meta-analysis of all published STAT4 associations revealed an OR of 1.25 (95% CI 1.19-1.33) (P = 1 x 10(-5)). CONCLUSION: Our findings indicate an association between the STAT4 polymorphism rs7574865 and RA in 3 different populations, from Spain, Sweden, and The Netherlands, thereby confirming previous data

    Expedition 361 summary

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    International Ocean Discovery Program Expedition 361 drilled six sites on the southeast African margin (southwest Indian Ocean) and in the Indian-Atlantic Ocean gateway, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days of on-site operations. The sites, situated in the Mozambique Channel at locations directly influenced by discharge from the Zambezi and Limpopo River catchments, the Natal Valley, the Agulhas Plateau, and Cape Basin, were targeted to reconstruct the history of the greater Agulhas Current system over the past ~5 My. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data further point at a potential role of the Agulhas Current in controlling the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Spillage of saline Agulhas water into the South Atlantic stimulates buoyancy anomalies that may influence basin-wide AMOC, with implications for convective activity in the North Atlantic and global climate change. The main objectives of the expedition were to establish the role of the Agulhas Current in climatic changes during the Pliocene–Pleistocene, specifically to document the dynamics of the Indian-Atlantic Ocean gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution. Additionally, the expedition set out to fulfill the needs of Ancillary Project Letter number 845, consisting of high-resolution interstitial water sampling to help constrain the temperature and salinity profiles of the ocean during the Last Glacial Maximum. The expedition made major strides toward fulfilling each of these objectives. The recovered sequences allowed generation of complete spliced stratigraphic sections that range from 0 to between ~0.13 and 7 Ma. This sediment will provide decadal- to millennial-scale climatic records that will allow answering the paleoceanographic and paleoclimatic questions set out in the drilling proposal
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