The quality of groundwaters in the central wheatbelt of W.A

IN south-western Australia permanent rivers are virtually absent and the larger drainage systems such as the Swan-Avon, Murray and Blackwood, which have their headwaters in inland low rainfall areas, are generally saline

Let\u27s look at herringbone dairies

THE first of the modern type herringbone dairies in Western Australia was constructed by Mr. F. Tucker of Ruabon, in 1957. Since then there has been strong interest in this system, and there are now at least six such sheds operating in the district between Ludlow and Augusta. Many more are being constructed

A Systematic Review on the Diagnosis of Pediatric Bacterial Pneumonia: When Gold Is Bronze

In developing countries, pneumonia is one of the leading causes of death in children under five years of age and hence timely and accurate diagnosis is critical. In North America, pneumonia is also a common source of childhood morbidity and occasionally mortality. Clinicians traditionally have used the chest radiograph as the gold standard in the diagnosis of pneumonia, but they are becoming increasingly aware that it is not ideal. Numerous studies have shown that chest radiography findings lack precision in defining the etiology of childhood pneumonia. There is no single test that reliably distinguishes bacterial from non-bacterial causes. These factors have resulted in clinicians historically using a combination of physical signs and chest radiographs as a 'gold standard', though this combination of tests has been shown to be imperfect for diagnosis and assigning treatment. The objectives of this systematic review are to: 1) identify and categorize studies that have used single or multiple tests as a gold standard for assessing accuracy of other tests, and 2) given the 'gold standard' used, determine the accuracy of these other tests for diagnosing childhood bacterial pneumonia.Search strategies were developed using a combination of subject headings and keywords adapted for 18 electronic bibliographic databases from inception to May 2008. Published studies were included if they: 1) included children one month to 18 years of age, 2) provided sufficient data regarding diagnostic accuracy to construct a 2x2 table, and 3) assessed the accuracy of one or more index tests as compared with other test(s) used as a 'gold standard'. The literature search revealed 5,989 references of which 256 were screened for inclusion, resulting in 25 studies that satisfied all inclusion criteria. The studies examined a range of bacterium types and assessed the accuracy of several combinations of diagnostic tests. Eleven different gold standards were studied in the 25 included studies. Criterion validity was calculated for fourteen different index tests using eleven different gold standards. The most common gold standard utilized was blood culture tests used in six studies. Fourteen different tests were measured as index tests. PCT was the most common measured in five studies each with a different gold standard.We have found that studies assessing the diagnostic accuracy of clinical, radiological, and laboratory tests for bacterial childhood pneumonia have used a heterogeneous group of gold standards, and found, at least in part because of this, that index tests have widely different accuracies. These findings highlight the need for identifying a widely accepted gold standard for diagnosis of bacterial pneumonia in children

Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot

Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs) provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR). However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR) data and Red Green and Blue (RGB) imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region.Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8) and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R2 of 0.8–0.9) allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented enables the integration of site-based biotic assessment with structural vegetation types for the rapid delineation and prioritization of key refugia

Soils of the Merredin area, Western Australia

Map from - Bettenay E and Hingston FJ (1961). Soils and Land Use of the Merredin area, Western Australia. CSIRO Australia. Division of Soils. Soils and Land Use Series No. 41https://researchlibrary.agric.wa.gov.au/lr_images/1097/thumbnail.jp

Adjustment of weak partial extraction data assuming metal ion adsorption: examples using bulk cyanide leach

<p><strong>ABSTRACT</strong> Geochemical analysis of soils using partial extractions, purported to detect only a fraction of elements mobilized during dispersion, represents a useful exploration tool. Interpretation of partial extraction data is, however, subject to uncertainty because the effects of changing soil or sediment properties on extraction are poorly defined. In particular, soil properties which are known to affect the retention of metal ions (e.g. clay content, organic carbon content, pH) may provide useful parameters against which to calculate adjusted total and partial assay values and thereby enhance anomaly contrast in geochemical exploration. Bulk cyanide leach (BCL), a commonly-used weak partial extraction technique, reduces the nugget effect for Au and can provide higher anomaly contrast than total elemental analyses. For a range of elements (Ag, Au, Cd, Co, Cu, Mo, Ni, Pd and Zn), we conducted BCL determinations, measured the same elements by NAA, XRF or aqua regia digest, and determined a range of soil chemical properties for traverses at 10 exploration prospects in Australia and Namibia. Raw total and BCL data were compared with (i) concentration : soil parameter ratios, and (ii) adjusted BCL values based on a simple model of trace element speciation in soils. Anomaly contrasts for raw and normalized or adjusted data were compared using an estimate of anomalism based on both quantitative and heuristic criteria. At prospects with soils containing detectable carbonate, normalization of total and BCL assays to carbonate content significantly improved multi-element anomaly contrast. Normalization to amorphous Fe or Mn oxide content, or total Al, K or Mg also significantly improved anomaly contrast at fewer prospects. Adjusting BCL values using a simple adsorption model also showed limited success in improving anomaly contrast, and represents a useful framework for interpreting weak partial extraction data. </p