1,664 research outputs found

    The age and provenance of Cambro-Ordovician sedimentary rocks of the Murrawong Creek Formation, southern New England Orogen, Australia

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    The Murrawong Creek and overlying Pipeclay Creek formations are a volcaniclastic sedimentary sequence containing some of the oldest fossil assemblages (Middle Cambrian to Ordovician) in the southern New England Orogen (NEO). These ages contrast markedly with the younger Devonian units that comprise most of the neighbouring Gamilaroi (Tamworth Group) and Djungati (Woolomin Group) terranes. Some researchers suggest that the fossils date allochthonous limestone blocks that slumped into younger deep marine basins. This project aims to test these competing hypotheses by utilizing detrital zircon geochronology (U-Pb SHRIMP dating) to establish the maximum depositional age by determining the youngest population of detrital zircons. Previous attempts to extract zircons from pre-Devonian rocks have been unsuccessful, but through targeting Zr-rich sandstone layers using a handheld XRF in the field, six detrital zircons were extracted from the Murrawong Creek Formation. All zircons show minimal rounding indicating minimal residence in sediment systems and are devoid of inherited cores derived from older melted crust. The youngest population of two zircons in the Murrawong Creek Formation have an age of 450 ±10 Ma indicating a maximum depositional age of ca. 460 – 440 (early Late Ordovician). The Pipeclay Creek Formation yielded thousands of zircons with a unimodal detrital zircon population of 443.4 ± 4.3 Ma, indicating a maximum depositional age in the latest Ordovician to earliest Silurian. This is consistent with the slightly older age of the Murrawong Creek Formation. These two formations still represent the oldest sedimentary units in the NEO, albeit younger than the age inferred from biostratigraphy. In a broader tectonic framework, two tectonic models explaining the Gamilaroi terrane currently exist: 1. the island arc is an exotic terrane which accreted onto the eastern margin of Gondwana via east directed subduction, 2. the island arc developed just outboard of Gondwana and was later merged onto the Gondwanan margin via continuously west directed subduction. The lack of ‘Gondwanan’ Precambrian zircon grains suggest that the sediments are sourced from an island arc receiving no sedimentary influence from Gondwana. Point counting results plotted in QFL diagrams confirm that these quartz-poor sediments were sourced from an undissected arc. Geochemical analysis identified calc-alkaline, tholeiitic, boninitic and MORB-like clasts within the conglomerate. Together with chert clasts, this suggests that sediment deposition occurred within a forearc basin of an intra-oceanic island arc that was eroding detritus derived from old, offscraped accretionary wedge material and the adjacent island arc volcanic edifice. This explains the mixture of Cambrian shallow water fauna from older accreted volcanic seamounts with Ordovician-Silurian zircons in the same formations. It is likely that these represent portions of a forearc basin from the earliest stage of development of the Gamilaroi terrane somewhere in the Panthalassan Ocean. The arc evolved to more felsic composition throughout the Late Ordovician whereby the erosional unroofing of arc plutonic rocks occurred, resulting in the increasing presence of monzonitic clasts and zircons in the Pipeclay Creek Formation. Subsequent arc rifting in the Devonian was followed by collision and accretion onto the Gondwanan margin during the latest Devonian

    Do different subjective evaluation criteria reflect distinct constructs?

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    This is not the published version. Published version available from: http://journals.lww.com/jonmd/pages/default.asp

    Comment on "Origin of Giant Optical Nonlinearity in Charge-Transfer--Mott Insulators: A New Paradigm for Nonlinear Optics"

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    Comment on Phys. Rev. Lett. 86, 2086 (2001)Comment: 1 page, 1 eps figur

    Soil fertility management for organic rice production in the Lao PDR

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    Rice is the most important agricultural commodity of the Lao People's Democratic Republic (Lao PDR), produced largely using traditional methods with limited inputs of fertilizers and other chemicals. The country has a wide diversity in rice production systems and rice varieties, with over 3000 different varieties recorded. The rich diversity and the production environment and methods are favorable for organic rice production. Investigations were carried out to describe soil fertility conditions, management practices, opportunities and problems associated with organic production methods for rice. Soils used for rice production are mostly of low fertility, with low organic matter and N-availability. In spite of this, virtually no fertilizer inputs are used for upland rice production. Inorganic fertilizer inputs for lowland rice production have increased rapidly over the past decade, but are still below 20 kg ha−1. The most important nutrient sources are rice straw and manure from buffalo and cattle. Chromolaena odorata plays an important role in nutrient cycling in upland rice systems and is sometimes added to lowland fields. In a range of fertility management studies, yield increase ranged from 2 to 89% for manure, straw or rice husk applied at modest rates (3 t ha−1), 32-156% for modest rates of inorganic fertilizer (60 kg N ha−1) and 36-167% for combined application of manure or crop residues with inorganic fertilizer. The response to locally produced commercial organic fertilizer was poor. The most promising inputs and strategies available to optimize yields in organic rice production systems are (1) optimizing use of locally available nutrients, mostly from manure, crop residues and weed biomass, (2) N addition through green manure and legumes growing in rotation and (3) additions of P through guano or rock-phosphate. The Lao PDR is fortunate to have substantial bat guano deposits in limestone caves. Extensive experience is available on straw and husk management for lowland systems and green manure species for upland production system

    Estimating prevalence of distant metastatic breast cancer: a means of filling a data gap

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    PURPOSE: To develop and validate a method for estimating numbers of people with distant cancer metastases, for evidence-based service planning. METHODS: Estimates were made employing an illness-death model with distant metastatic cancer as the illness state- and site-specific mortality as an outcome, using MIAMOD software. To demonstrate the method, we estimated numbers of females alive in Australia following detection of distant metastatic breast cancer during 1980-2004, using data on patient survival from an Australian population-based cancer registry. We validated these estimates by comparing them with direct prevalence counts. RESULTS: Relative survival at 10 years following detection of distant metastases was low (5-20 %), with better survival experienced by: (1) females where distant metastatic disease was detected at initial diagnosis rather than subsequently (e.g., at recurrence); (2) those diagnosed in more recent calendar years; and (3) younger age groups. For Australian females aged less than 85 years, the modeled cumulative risk of detection of distant metastatic breast cancer (either at initial diagnosis or subsequently) declined over time, but numbers of cases with this history rose from 71 per 100,000 in 1980 to 84 per 100,000 in 2004. The model indicated that there were approximately 3-4 prevalent distant metastatic breast cancer cases for every breast cancer death. Comparison of estimates with direct prevalence counts showed a reasonable level of agreement. CONCLUSIONS: The method is straightforward to apply and we recommend its use for breast and other cancers when registry data are insufficient for direct prevalence counts. This will provide estimates of numbers of people who would need ongoing medical surveillance and care following detection of distant metastase

    Validation of administrative hospital data for identifying incident pancreatic and periampullary cancer cases: A population-based study using linked cancer registry and administrative hospital data in New South Wales, Australia

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    © 2015 Published by the BMJ Publishing Group Limited. For permission to use. Objectives: Informing cancer service delivery with timely and accurate data is essential to cancer control activities and health system monitoring. This study aimed to assess the validity of ascertaining incident cases and resection use for pancreatic and periampullary cancers from linked administrative hospital data, compared with data from a cancer registry (the 'gold standard'). Design, setting and participants: Analysis of linked statutory population-based cancer registry data and administrative hospital data for adults (aged .18 years) with a pancreatic or periampullary cancer case diagnosed during 2005.2009 or a hospital admission for these cancers between 2005 and 2013 in New South Wales, Australia. Methods: The sensitivity and positive predictive value (PPV) of pancreatic and periampullary cancer case ascertainment from hospital admission data were calculated for the 2005.2009 period through comparison with registry data. We examined the effect of the look-back period to distinguish incident cancer cases from prevalent cancer cases from hospital admission data using 2009 and 2013 as index years. Results: Sensitivity of case ascertainment from the hospital data was 87.5% (4322/4939), with higher sensitivity when the cancer was resected (97.9%, 715/730) and for pancreatic cancers (88.6%, 3733/4211). Sensitivity was lower in regional (83.3%) and remote (85.7%) areas, particularly in areas with interstate outflow of patients for treatment, and for cases notified to the registry by death certificate only (9.6%). The PPV for the identification of incident cases was 82.0% (4322/5272). A 2-year look-back period distinguished the majority (98%) of incident cases from prevalent cases in linked hospital data. Conclusions: Pancreatic and periampullary cancer cases and resection use can be ascertained from linked hospital admission data with sufficient validity for informing aspects of health service delivery and system-level monitoring. Limited tumour clinical information and variation in case ascertainment across population subgroups are limitations of hospitalderived cancer incidence data when compared with population cancer registries

    Increased fluorescence of PbS quantum dots in photonic crystals by excitation enhancement

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    We report on the enhanced fluorescence of lead sulfide quantum dots interacting with leaky modes of slab type silicon photonic crystals. The photonic crystal slabs were fabricated, supporting leaky modes in the near infrared wavelength range. Lead sulfite quantum dots which are resonant in the same spectral range were prepared in a thin layer above the slab. We selectively excited the leaky modes by tuning the wavelength and angle of incidence of the laser source and measured distinct resonances of enhanced fluorescence. By an appropriate experiment design, we ruled out directional light extraction effects and determined the impact of enhanced excitation. Three dimensional numerical simulations consistently explain the experimental findings by strong near field enhancements in the vicinity of the photonic crystal surface. Our study provides a basis for systematic tailoring of photonic crystals used in biological applications such as biosensing and single molecule detection, as well as quantum dot solar cells and spectral conversion application

    Epithelial cells in bone marrow of oesophageal cancer patients: a significant prognostic factor in multivariate analysis

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    The detection of epithelial cells in bone marrow, blood or lymph nodes indicates a disseminatory potential of solid tumours. 225 patients with squamous cell carcinoma of the oesophagus were prospectively studied. Prior to any therapy, cytokeratin-positive (CK) cells in bone marrow were immunocytochemically detected in 75 patients with the monoclonal anti-epithelial-cell antibody A45-B/B3 and correlated with established histopathologic and patient-specific prognosis factors. The prognosis factors were assessed by multivariate analysis. Twenty-nine of 75 (38.7%) patients with oesophageal cancer showed CK-positive cells in bone marrow. The analyses of the mean and median overall survival time showed a significant difference between patients with and without epithelial cells in bone marrow (P< 0.001). Multivariate analysis in the total patient population and in patients with curative resection of the primary tumour confirmed the curative resection rate and the bone marrow status as the strongest independent prognostic factors, besides the T-category. The detection of epithelial cells in bone marrow of oesophageal cancer patients is a substantial prognostic factor proved by multivariate analysis and is helpful for exact preoperative staging, as well as monitoring of neoadjuvant therapy. © 2000 Cancer Research Campaig

    History of screening by BreastScreen New South Wales of women with invasive breast cancer

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    © 2019 The Author(s) Background: The principal target age for Australian BreastScreen services was 50–69 years in 1991–2013 and 50–74 years from 2014. History of BreastScreen NSW screening participation of NSW women diagnosed with breast cancer in 2005–2014 was examined using linked BreastScreen and Cancer Registry data. Methods: Differences in BreastScreen participation were investigated by sociodemographic and tumour characteristics, and diagnostic period, using the Pearson Chi-square test, or Fisher's Exact test when numbers were small, and by multivariate logistic regression. Results: At breast cancer diagnosis, a history of BreastScreen participation varied by age from 23 % for 40−49 years to 68 % for 50–59 years, 72 % for 70–74 years and 78 % for 60–69 years. Among women experiencing breast cancer at age 50–69 years, 60 % had participated in BreastScreen <24 months of diagnosis. Higher odds of BreastScreen participation applied to residents of inner regional and remote compared with major city areas and for women with localized compared with more distant cancer spread. BreastScreen participation was lower in Indigenous than non-Indigenous women. Differences in participation existed by country of birth and residential location, but they were not pronounced. Conclusion: The history of BreastScreen NSW participation of 60 % <24 months for women aged 50–69 years at breast-cancer diagnosis is less than the 70 % target for biennial screening coverage at a population level, but this target has never been reached by an Australian jurisdiction. Qualitative research of screening barriers and opportunities may provide a useful guide for reducing barriers across the population

    Country of birth and non-small cell lung cancer incidence, treatment, and outcomes in New South Wales, Australia: a population-based linkage study.

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    OBJECTIVE: To compare treatment within 12 months of diagnosis, and survival by country of birth for people diagnosed with invasive non-small cell lung cancer (NSCLC) in New South Wales (NSW), Australia. DESIGN, PATIENTS, AND SETTING: A population-based cohort study of NSW residents diagnosed with NSCLC in 2003-2016 using de-identified linked data from the NSW Cancer Registry, NSW Admitted Patient Data collection, Emergency Departments, Medicare Benefits and Pharmaceutical Benefits Scheme, and National Death Index. MAIN OUTCOME MEASURES: Odds of receiving any treatment, surgery, systemic therapy, or radiotherapy respectively, in the 12 months following diagnosis were calculated using multivariable logistic regression. The hazard of death (all-cause) at one- and five-years following diagnosis was calculated using multivariable proportional hazards regression. RESULTS: 27,114 People were recorded with NSCLC in the 14-year study period. Higher percentages of older males from European countries applied in the earlier years, with a shift to younger people from South East Asia, New Zealand, and the Middle East. Adjusted analyses indicated that, compared with the Australian born, people from European countries were more likely to receive treatment, and, specifically surgery. Also, people from Asian countries were more likely to receive systemic therapy but less likely to receive radiotherapy. Survival at one- and five-years following diagnosis was higher for people born in countries other than Australia, New Zealand the United Kingdom and Germany. CONCLUSIONS: Variations exist in treatment and survival by country of birth in NSW. This may be affected by differences in factors not recorded in the NSW Registry, including use of general health services, family histories, underlying health conditions, other intrinsic factors, and cultural, social, and behavioural influences
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