3,149 research outputs found

    Key environmental criteria associated with the invasion of Anguilla australis glass eels into estuaries of south-eastern Australia

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    Sampling for glass eels of the shortfinned eel, Anguilla australis, was conducted in a number of estuaries in south-eastern Australia using glass eel and stow nets during the winter and spring months of 1994 and 1995. Preliminary modelling of the invasion of A. australis glass eels was undertaken by determining correlations between Catch Per Unit Effort (CPUE) of glass eels and water temperature, electrical conductivity, lunar phase and height of high tide. Low (< 10000 µS/cm) electrical conductivity, medium (10-14°C) water temperature and high (>0m AHD) tide height showed significant correlation with high CPUE, but lunar phase (as moon age in days) did not. There appears to be some scope for predicting the invasion of A. australis glass eels into south-eastern Australian estuaries using temperature and electrical conductivity as key criteria for determining when glass eel fishing should commence. Such information is expected to contribute to the development of a commercial glass eel fishery in south-eastern Australia

    Mass and density of B-type asteroid (702) Alauda

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    Observations with the adaptive optics system on the Very Large Telescope reveal that outer main belt asteroid (702) Alauda has a small satellite with primary to secondary diameter ratio of \sim56. The secondary revolves around the primary in 4.9143 ±\pm 0.007 days at a distance of 1227 ±\pm 24 km, yielding a total system mass of (6.057 ±\pm 0.36) ×\times 1018^{18} kg. Combined with an IRAS size measurement, our data yield a bulk density for this B-type asteroid of 1570 ±\pm 500 kg~m3^{-3}.Comment: In press, ApJ 2011. 6 pages, 4 figure

    The impact of freight transport capacity limitations on supply chain dynamics

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    We investigate how capacity limitations in the transportation system affect the dynamic behaviour of supply chains. We are interested in the more recently defined, 'backlash' effect. Using a system dynamics simulation approach, we replicate the well-known Beer Game supply chain for different transport capacity management scenarios. The results indicate that transport capacity limitations negatively impact on inventory and backlog costs, although there is a positive impact on the 'backlash' effect. We show that it is possible for both backlog and inventory to simultaneous occur, a situation which does not arise with the uncapacitated scenario. A vertical collaborative approach to transport provision is able to overcome such a trade-off. © 2013 Taylor & Francis

    Letter from L. H. Boothe

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    Letter concerning the college choir at Utah Agricultural College

    What is the extent and distribution of evidence on effectiveness of systematic conservation planning around the globe? A systematic map protocol

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    Background: Systematic conservation planning involves the prioritisation of conservation actions to optimise biodiversity conservation outcomes whilst considering implementation challenges such as minimising costs. Thousands of systematic conservation plans have been developed around the globe (a popular software package, 'Marxan', has over 4200 active users from more than 180 countries). However, the effects of systematic approaches on conservation actions and outcomes are not generally known, nor are the factors which distinguish effective from ineffective plans. Previous reviews of conservation planning outcomes have been limited in scope and to narrow time intervals, and have revealed very few formal evaluations of plans. Given systematic approaches are widely perceived to offer the best chance to rapidly and efficiently achieve biodiversity protection targets, a thorough, up-to-date synthesis of the evidence is required. Methods: This protocol outlines the methodology for a systematic mapping exercise to identify retrospective studies measuring the effects of systematic conservation planning on biodiversity conservation at regional, national and subnational scales. Our primary research question is: what is the extent and distribution of evidence on the conservation outcomes of systematic conservation planning? Outcomes will be categorised according to types of capital: natural, financial, social, human and institutional, given the range of potential direct and indirect effects of systematic conservation planning on conservation outcomes. A comprehensive and repeatable search strategy will be undertaken, utilising a wide range of sources including grey literature sources and targeted searches of organisational websites and databases. Sources will be restricted to English language publications between 1983 and 2016. The resultant studies will be screened using standardised inclusion and exclusion criteria and data from included studies will be categorised according to a standardised data extraction form. Information about the study design of relevant articles will be recorded to determine study robustness. A searchable database of studies will be made publicly accessible and available for updating in future. The results will be published in this journal and also presented as an interactive online resource to aid conservation planners in identifying impacts and outcomes of conservation plans

    Experimental study of digital image processing techniques for LANDSAT data

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    The author has identified the following significant results. Results are reported for: (1) subscene registration, (2) full scene rectification and registration, (3) resampling techniques, (4) and ground control point (GCP) extraction. Subscenes (354 pixels x 234 lines) were registered to approximately 1/4 pixel accuracy and evaluated by change detection imagery for three cases: (1) bulk data registration, (2) precision correction of a reference subscene using GCP data, and (3) independently precision processed subscenes. Full scene rectification and registration results were evaluated by using a correlation technique to measure registration errors of 0.3 pixel rms thoughout the full scene. Resampling evaluations of nearest neighbor and TRW cubic convolution processed data included change detection imagery and feature classification. Resampled data were also evaluated for an MSS scene containing specular solar reflections

    Altered hippocampal function in major depression despite intact structure and resting perfusion

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    Background: Hippocampal volume reductions in major depression have been frequently reported. However, evidence for functional abnormalities in the same region in depression has been less clear. We investigated hippocampal function in depression using functional magnetic resonance imaging (fMRI) and neuropsychological tasks tapping spatial memory function, with complementing measures of hippocampal volume and resting blood flow to aid interpretation. Method: A total of 20 patients with major depressive disorder (MDD) and a matched group of 20 healthy individuals participated. Participants underwent multimodal magnetic resonance imaging (MRI): fMRI during a spatial memory task, and structural MRI and resting blood flow measurements of the hippocampal region using arterial spin labelling. An offline battery of neuropsychological tests, including several measures of spatial memory, was also completed. Results: The fMRI analysis showed significant group differences in bilateral anterior regions of the hippocampus. While control participants showed task-dependent differences in blood oxygen level-dependent (BOLD) signal, depressed patients did not. No group differences were detected with regard to hippocampal volume or resting blood flow. Patients showed reduced performance in several offline neuropsychological measures. All group differences were independent of differences in hippocampal volume and hippocampal blood flow. Conclusions: Functional abnormalities of the hippocampus can be observed in patients with MDD even when the volume and resting perfusion in the same region appear normal. This suggests that changes in hippocampal function can be observed independently of structural abnormalities of the hippocampus in depression
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