654 research outputs found

    Application of Dexter’s soil physical quality index: an Irish case study

    Get PDF
    peer-reviewedHistorically, due to a lack of measured soil physical data, the quality of Irish soils was relatively unknown. Herein, we investigate the physical quality of the national representative profiles of Co. Waterford. To do this, the soil physical quality (SPQ) S-Index, as described by Dexter (2004a,b,c) using the S-theory (which seeks the inflection point of a soil water retention curve [SWRC]), is used. This can be determined using simple (S-Indirect) or complex (S-Direct) soil physical data streams. Both are achievable using existing data for the County Waterford profiles, but until now, the suitability of this S-Index for Irish soils has never been tested. Indirect-S provides a generic characterisation of SPQ for a particular soil horizon, using simplified and modelled information (e.g. texture and SWRC derived from pedo-transfer functions), whereas Direct-S provides more complex site-specific information (e.g. texture and SWRC measured in the laboratory), which relates to properties measured for that exact soil horizon. Results showed a significant correlation between S-Indirect (Si) and S-Direct (Sd). Therefore, the S-Index can be used in Irish soils and presents opportunities for the use of Si at the national scale. Outlier horizons contained >6% organic carbon (OC) and bulk density (Bd) values <1 g/cm3 and were not suitable for Si estimation. In addition, the S-Index did not perform well on excessively drained soils. Overall correlations of Si. with Bd and of Si. with OC% for the dataset were detected. Future work should extend this approach to the national scale dataset in the Irish Soil Information System.Funding was provided as part of Department of Agriculture, Food and the Marine (DAFM) Soil Quality Assessment and Research (SQUARE) Research Stimulus Fund No. 6582.Task 1 output

    A methodological framework to determine optimum durations for the construction of soil water characteristic curves using centrifugation

    Get PDF
    peer-reviewedDuring laboratory assessment of the soil water characteristic curve (SWCC), determining equilibrium at various pressures is challenging. This study establishes a methodological framework to identify appropriate experimental duration at each pressure step for the construction of SWCCs via centrifugation. Three common temporal approaches to equilibrium – 24-, 48- and 72-h – are examined, for a grassland and arable soil. The framework highlights the differences in equilibrium duration between the two soils. For both soils, the 24-h treatment significantly overestimated saturation. For the arable site, no significant difference was observed between the 48- and 72-h treatments. Hence, a 48-h treatment was sufficient to determine ‘effective equilibrium’. For the grassland site, the 48- and 72-h treatments differed significantly. This highlights that a more prolonged duration is necessary for some soils to conclusively determine that effective equilibrium has been reached. This framework can be applied to other soils to determine the optimum centrifuge durations for SWCC construction.Teagasc Walsh Fellowship Programm

    Graphical representation of the partition function for a 1-D delta-function Bose gas

    Full text link
    One-dimensional repulsive delta-function bose system is studied. By only using the Bethe ansatz equation, n-particle partition functions are exactly calculated. From this expression for the n-particle partition function, the n-particle cluster integral is derived. The results completely agree with those of the thermal Bethe ansatz (TBA). This directly proves the validity of the TBA. The theory of partitions and graphs is used to simplify the discussion.Comment: 15 page

    Local correlations in a strongly interacting 1D Bose gas

    Full text link
    We develop an analytical method for calculating local correlations in strongly interacting 1D Bose gases, based on the exactly solvable Lieb-Liniger model. The results are obtained at zero and finite temperatures. They describe the interaction-induced reduction of local many-body correlation functions and can be used for achieving and identifying the strong-coupling Tonks-Girardeau regime in experiments with cold Bose gases in the 1D regime.Comment: 8 pages, REVTeX4, published in the New Journal of Physic

    The quantum non-linear Schrodinger model with point-like defect

    Get PDF
    We establish a family of point-like impurities which preserve the quantum integrability of the non-linear Schrodinger model in 1+1 space-time dimensions. We briefly describe the construction of the exact second quantized solution of this model in terms of an appropriate reflection-transmission algebra. The basic physical properties of the solution, including the space-time symmetry of the bulk scattering matrix, are also discussed.Comment: Comments on the integrability and the impurity free limit adde

    Universal correlations of trapped one-dimensional impenetrable bosons

    Full text link
    We calculate the asymptotic behaviour of the one body density matrix of one-dimensional impenetrable bosons in finite size geometries. Our approach is based on a modification of the Replica Method from the theory of disordered systems. We obtain explicit expressions for oscillating terms, similar to fermionic Friedel oscillations. These terms are universal and originate from the strong short-range correlations between bosons in one dimension.Comment: 18 pages, 3 figures. Published versio

    Mapping Soils in Ireland

    Get PDF
    peer-reviewedThis project is jointly funded by Teagasc and EPA STRIVE funding.Harmonised soil data across Europe with a 1:250 000 geo-referenced soil database will allow for exchange of data across member states and the provide the information needed for reporting on issues re-lating to soil quality under a future Soil Framework Directive. The current status of soils data available in Eu-rope is inconsistent at best. The Irish Soil Information System (ISIS) project is currently developing a national soil map of 1:250,000 and an associated digital soil information system, providing both spatial and quantita-tive information on soil types and properties across Ireland. Both the map and the information system will be freely available to the public through a designated website.This project is jointly funded by Teagasc and EPA STRIVE funding

    Digital Soil Mapping in the Irish Soil Information System

    Get PDF
    Harmonised soil data across Europe with a 1:250 000 geo-referenced soil database will allow for exchange of data across member states and the provide the information needed by the European Commission and European Environment Agency for reporting on issues relating to soil quality under a fu-ture Soil Framework Directive. Within this context, the Environmental Protection Agency of the Republic of Ireland commissioned a project run by Teagasc to produce a 1:250 000 soil map of the Republic of Ire-land. Delivery of this map and associated database is a collaborative effort between Teagasc, the National Soil Resources Institute at Cranfield in the UK and University College Dublin.Environmental Protection Agenc

    Internet-based prevention of posttraumatic stress symptoms in injured trauma patients: design of a randomized controlled trial.

    Get PDF
    Background: Injured trauma victims are at risk of developing Posttraumatic Stress Disorder (PTSD) and other post-trauma psychopathology. So far, interventions using cognitive behavioral techniques (CBT) have proven most efficacious in treating early PTSD in highly symptomatic individuals. No early intervention for the prevention of PTSD for all victims has yet proven effective. In the acute psychosocial care for trauma victims, there is a clear need for easily applicable, accessible, cost-efficient early interventions. Objective: To describe the design of a randomized controlled trial (RCT) evaluating the effectiveness of a brief Internet-based early intervention that incorporates CBT techniques with the aim of reducing acute psychological distress and preventing long-term PTSD symptoms in injured trauma victims. Method: In a two armed RCT, 300 injured trauma victims from two Level-1 trauma centers in Amsterdam, the Netherlands, will be assigned to an intervention or a control group. Inclusion criteria are: being 18 years of age or older, having experienced a traumatic event according to the diagnostic criteria of the DSM-IV and understanding the Dutch language. The intervention group will be given access to the intervention&#x0027;s website (www.traumatips.nl), and are specifically requested to login within the first month postinjury. The primary clinical study outcome is PTSD symptom severity. Secondary outcomes include symptoms of depression and anxiety, quality of life, and social support. In addition, a cost-effectiveness analysis of the intervention will be performed. Data are collected at one week post-injury, prior to first login (baseline), and at 1, 3, 6 and 12 months. Analyses will be on an intention-to-treat basis. Discussion: The results will provide more insight into the effects of preventive interventions in general, and Internet-based early interventions specifically, on acute stress reactions and PTSD, in an injured population, during the acute phase after trauma. We will discuss possible strengths and limitations

    Temperature Dependence of Backbone Dynamics in Human Ileal Bile Acid-Binding Protein: Implications for the Mechanism of Ligand Binding

    Get PDF
    Human ileal bile acid-binding protein (I-BABP), a member of the family of intracellular lipid binding proteins plays a key role in the cellular trafficking and metabolic regulation of bile salts. The protein has two internal and, according to a recent study, an additional superficial binding site and binds di- and trihydroxy bile salts with positive cooperativity and a high degree of site-selectivity. Previously, in the apo form, we have identified an extensive network of conformational fluctuations on the millisecond time scale, which cease upon ligation. Additionally, ligand binding at room temperature was found to be accompanied by a slight rigidification of picosecond-nanosecond (ps-ns) backbone flexibility. In the current study, temperature-dependent N-15 NMR spin relaxation measurements were used to gain more insight into the role of dynamics in human I-BABP-bile salt recognition. According to our analysis, residues sensing a conformational exchange in the apo state can be grouped into two clusters with slightly different exchange rates. The entropy-enthalpy compensation observed for both clusters suggests a disorder-order transition between a ground and a sparsely populated higher energy state in the absence of ligands. Analysis of the faster, ps-ns motion of N-15-H-1 bond vectors indicates an unusual nonlinear temperature-dependence for both ligation states. Intriguingly, while bile salt binding results in a more uniform response to temperature change throughout the protein, the temperature derivative of the generalized order parameter shows different responses to temperature increase for the two forms of the protein in the investigated temperature range. Analysis of both slow and fast motions in human I-BABP indicates largely different energy landscapes for the apo and halo states suggesting that optimization of binding interactions might be achieved by altering the dynamic behavior of specific segments in the protein
    corecore