6,141 research outputs found
The effects of organic farming on the soil physical environment
The aim of this research was to investigate the effects of organic farming practices on the development of soil physical properties, and in particular, soil structure in comparison with conventional agricultural management. The soil structure of organically and conventionally managed soils at one site was compared in a quantitative manner at different scales of observations using image analysis. Key soil physical and chemical properties were measured as well as the pore fractal geometry to characterise pore roughness. Organically managed soils had higher organic matter content and provided a more stable soil structure than conventionally managed soils. The higher porosity (%) at the macroscale in soil under conventional management was due to fewer larger pores while mesoand microscale porosity was found to be greater under organic management. Organically managed soils typically provided spatially well distributed pores of all sizes and of greater roughness compared to those under conventional management. These variations in the soil physical environment are likely to impact significantly on the performance of these soils for a number of key processes such as crop establishment and water availabilit
Assessing the influence of the rhizosphere on soil hydraulic properties using X-ray Computed Tomography and numerical modelling
Understanding the dynamics of water distribution in soil is crucial for enhancing our knowledge of managing soil and water resources. The application of X-ray Computed Tomography (CT) to the plant and soil sciences is now well established. However, few studies have utilised the technique for visualising water in soil pore spaces. Here we utilise this method to visualise the water in soil in situ and in three-dimensions at successive reductive matric potentials in bulk and rhizosphere soil. The measurements are combined with numerical modelling to determine the unsaturated hydraulic conductivity, providing a complete picture of the hydraulic properties of the soil. The technique was performed on soil cores that were sampled adjacent to established roots (rhizosphere soil) and from soil that had not been influenced by roots (bulk soil). A water release curve was obtained for the different soil types using measurements of their pore geometries derived from CT imaging and verified using conventional methods e.g. pressure plates. The water, soil and air phases from the images were segmented and quantified using image analysis. The water release characteristics obtained for the contrasting soils showed clear differences in hydraulic properties between rhizosphere and bulk soil, especially in clay soil. The data suggests that soils influenced by roots (rhizosphere soil) are less porous due to increased aggregation when compared to bulk soil. The information and insights obtained on the hydraulic properties of rhizosphere and bulk soil will enhance our understanding of rhizosphere biophysics and improve current water uptake models
Thinking beyond the hybrid:âactually-existingâ cities âafter neoliberalismâ in Boyle <i>et al.</i>
In their article, âThe spatialities of actually existing neoliberalism in Glasgow, 1977 to presentâ, Mark Boyle, Christopher McWilliams and Gareth Rice (2008) usefully problematise our current understanding of neoliberal urbanism. Our response is aimed at developing a sympathetic but critical approach to Boyle et al's understanding of neoliberal urbanism as illustrated by the Glasgow example. In particular, the counterposing by Boyle et al of a 'hybrid, mutant' model to a 'pure' model of neoliberalism for us misrepresents existing models of neoliberalism as a perfectly finished object rather than a roughly mottled process. That they do not identify any âpureâ model leads them to create a straw construct against which they can claim a more sophisticated, refined approach to the messiness of neoliberal urbanism. In contrast, we view neoliberalism as a contested and unstable response to accumulation crises at various scales of analysis
Book Recommending Using Text Categorization with Extracted Information
Content-based recommender systems suggest documents, items, and services to users based on learning a profile of the user from rated examples containing information about the given items. Text categorization methods are very useful for this task but generally rely on unstructured text. We have developed a bookrecommending system that utilizes semi-structured information about items gathered from the web using simple information extraction techniques. Initial experimental results demonstrate that this approach can produce fairly accurate recommendations. Introduction There is a growing interest in recommender systems that suggest music, films, and other items and services to users (e.g. www.bignote.com, www.filmfinder.com) (Maes 1994; Resnik & Varian 1997). These systems generally make recommendations using a form of computerized matchmaking called collaborative filtering. The system maintains a database of the preferences of individual users, finds other users whose known preferenc..
Report of the Sydney Women and Sexual Health (SWASH) Survey 2006, 2008, 2010, 2012, 2014
The Sydney Women and Sexual Health (SWASH) survey is a comprehensive survey of important health issues relevant to lesbian, bisexual and queer (LBQ) women including sexual health and wellbeing, violence, mental health, tobacco use, illicit drug use, alcohol consumption, and cancer screening behaviours. This report presents results from surveys conducted at the Sydney Gay and Lesbian Mardi Gras Fair Day and other community events and venues during the Sydney Gay and Lesbian Mardi Gras seasons in 2006, 2008, 2010, 2012, and 2014. It highlights several health issues of particular concern â many of which have persisted over time â where mainstream preventive health interventions that are inclusive of this group or targeted to LBQ, are needed.ACON (formerly the AIDS Council of NSW) is NSWâs leading health promotion organisation specialising in HIV prevention, care and support, and lesbian, gay, bisexual, transgender and intersex (LGBTI) health
Hybrid density functional theory description of N- and C-doping of NiO
The large intrinsic bandgap of NiO hinders its potential application as a photocatalyst under visible-light irradiation. In this study, we have performed first-principles screened exchange hybrid density functional theory with the HSE06 functional calculations of N- and C-doped NiO to investigate the effect of doping on the electronic structure of NiO. C-doping at an oxygen site induces gap states due to the dopant, the positions of which suggest that the top of the valence band is made up primarily of C 2p-derived states with some Ni 3d contributions, and the lowest-energy empty state is in the middle of the gap. This leads to an effective bandgap of 1.7 eV, which is of potential interest for photocatalytic applications. N-doping induces comparatively little dopant-Ni 3d interactions, but results in similar positions of dopant-induced states, i.e., the top of the valence band is made up of dopant 2p states and the lowest unoccupied state is the empty gap state derived from the dopant, leading to bandgap narrowing. With the hybrid density functional theory (DFT) results available, we discuss issues with the DFT corrected for on-site Coulomb description of these systems
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Neuroimaging the sleeping brain: Insight on memory functioning in infants and toddlers.
Episodic memory, or the ability to remember past events with specific detail, is central to the human experience and is related to learning and adaptive functioning in a variety of domains. In typically developing children, episodic memory emerges during infancy and improves during early childhood and beyond. Developmental processes within the hippocampus are hypothesized to be primarily responsible for both the early emergence and persistence of episodic memory in late infancy and early childhood. However, these hypotheses are based on non-human models. In-vivo investigations in early human development of hippocampal processes have been significantly limited by methodological challenges in acquiring neuroimaging data, particularly task-related functional neuroimaging data, from infants and toddlers. Recent studies in adults have shown neural activity in the brain regions supporting episodic memory during slow-wave sleep using functional magnetic resonance imaging (fMRI), and fMRI has been increasingly utilized in infancy and early childhood to address other research questions. We review initial evidence and present preliminary data showing the promise of this approach for examining hippocampal contribution to how infants and toddlers remember individual events, and their association with information about the context in which the event occurred. Overall, our review, integrated with the presentation of some preliminary data provides insight on leveraging sleep to gain new perspectives on early memory functioning
Multiple Kinase Involvement in the Regulation of Vascular Growth
The initial discovery of protein phosphorylation as a regulatory mechanism for the control of glycogen metabolism has led to intense interest of protein phosphorylation in regulating protein function (Cohen et al., 2001). Kinases play a variety of roles in many physiological processes within cells and represent one of the largest families in the human genome with over 500 members comprising protein serine/threonine, tyrosine, and dual-specificity kinases (Manning et al., 2002). Phosphorylation of proteins is one of the most significant signal transduction mechanisms which regulate intracellular processes such as transport, growth, metabolism, apoptosis, cystoskeletal arrangement and hormone responses (Bononi et al., 2011; Heidenreich et al., 1991; Manning et al., 2002; Pawson et al., 2000). As such, abnormal phosphorylation of proteins can be either a cause or a consequence of disease. Kinases are regulated by activator and inhibitor proteins, ligand binding, and phosphorylation by other proteins or via autophosphorylation (Hanks et al., 1991; Hug et al., 1993; Scott, 1991; Taylor et al., 1990; Taylor et al., 1992). Since kinases play key functions in many cellular processes, they represent an attractive target for therapeutic interventions in many disease states such as cancer, inflammation, diabetes and arthritis (Cohen et al., 2010; Fry et al., 1994; Karin, 2005; Mayers et al., 2005). In particular, the serine/threonine family of kinases comprises approximately 125 of the 500 family of kinases and includes the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA), the cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG), and protein kinase C (PKC). These kinases are implicated in the regulation of cell growth and are the focus of this current study.We would like to acknowledge Jonathan C. Fox and Patti Shaver for assistance with isolation and culture of rat primary vascular smooth muscle cells. This project was supported by Award Number R01HL081720 from the National Institutes of Health National
Heart, Lung, and Blood Institute (NHLBI), by ARRA Award Number R01HL081720-03S2, and by Post-doctoral Research Supplement Award Number R01HL081720-05S1 from the NHLBI
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