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Quantitative description of root-water uptake under combined salinity and water stress is needed to optimize crop yields and water management in arid and semiarid regions. This study was conducted to develop a simple macroscopic root-water uptake model for nonuniform transient soil water content and salinity conditions in the root zone. This new model and previous models were tested against detailed experimental data obtained with Alfalfa (Medicago sativa L.) grown in the greenhouse in packed sandy loam (Typic Haplaquent) columns. Soil water content, pressure head, and osmotic head distributions in the root zone were varied by means of the amounts, application intervals, and salinities of the irrigation water. Experimental data under separate and combined stresses were used to test the various models using mean values of soil solution osmotic and pressure heads. The simple additive reduction function provided the worst agreement with the experimental data, while for most cases the multiplicative reduction functions could not adequately account for both water and salinity stress conditions. The newly proposed linear reduction function is neither additive nor multiplicative, but was assumed that both the intersect and slope of the reduction function increased with salinity. This model provided excellent agreement with the experimental data, particularly at higher soil solution salinities. The new reduction function could be used with any other nonlinear salinity reduction function.

Comparison of six different laboratory methods for obtaining hydraulic diffusivity and conductivity on eolian silt loam, eolian sand, fluviatile silt loam and marine sandy loam reveals that all the methods yield different results. The information about soil hydraulic properties is essential for the development of soil-waterflow models, making the accurate determination of the properties important. The comparison of the different methods could not be effectively performed due to hysteresis.

Automatic atomized water spray system is used to measure the soil hydraulic conductivity as function of volumetric water content. This technique enables the accurate prediction of soil hydraulic conductivities between saturation and values around 0.1 mm/d. Simultaneous measurements with time-domain reflectometry exhibit the hydraulic conductivity as a single-valued function of water content.

Researchers compared the Topp-Davis-Annan calibration equation with a theoretical (Maxwell-De Loor) and an empirical (fitting exponent alpha) mixing construct for the solid phase (s), tightly bound water (bw), free water and air components. The Maxwell-De Loor equation allows for effects and ostensible anomalous behavior such as falling effective Epsilon with rising Epsilon s, which shows that it is the better calibration equation.

The development of surface seals on soils under different rain intensities is affected by erosion, runoff and infiltration. In an experiment conducted to study the evolution of soil horizons under different rain intensities, high values for surface seal conductances occurred when the seal was partially open. Maximum thickening of the surface seal and minimum macroporosity was observed five minutes after intensity peak. Soil erosion was heightened with continous rain as the surface seal thinned out and total porosity in terms of planar voids increased.

Aim: There is considerable heterogeneity in outcomes in studies reporting on the treatment of haemorrhoidal disease (HD). The aim of this study was to develop a Core Outcome Set (COS) for HD in cooperation with the European Society of Coloproctology. Method: A Delphi study was performed according to the Outcome Measures in Rheumatology (OMERACT) methodology. In total 38 healthcare professionals and 30 patients were invited to the panel. Previously, 10 outcome domains and 59 outcomes were identified through a systematic literature review. In this study, these domains and outcomes were formed into one questionnaire for healthcare professionals and a separate questionnaire for patients. Sequential questionnaire rounds prioritizing the domains and outcomes were conducted. Panel members were asked to rate the appropriateness of each domain and outcome on a nine‐point Likert scale. During a face‐to‐face meeting, healthcare professionals agreed on the primary and secondary end‐points of the COS for HD. Finally, a short survey was sent to the healthcare professionals in order to reach consensus on how the chosen end‐points should be assessed and at which time points. Results: The response rate in questionnaire round 1 for healthcare professionals was 44.7% (n = 17). Sixteen out of 17 healthcare professionals also completed the questionnaire in round 2. The response rate for the patient questionnaire was 60% (n = 18). Seventeen healthcare professionals participated in the face‐to‐face meeting. The questionnaire rounds did not result in a clear‐cut selection of primary and secondary end‐points. Most domains and outcomes were considered important, and only three outcomes were excluded. During the face‐to‐face meeting, agreement was reached to select the domain 'symptoms' as primary end‐point, and 'complications', 'recurrence' and 'patient satisfaction' as secondary end‐points in the COS for HD. Furthermore, consensus was reached that the domain 'symptoms' should be a patient reported outcome measure and should include the outcomes 'pain' and 'prolapse', 'itching', 'soiling' and 'blood loss'. The domain 'complications' should include the outcomes 'incontinence', 'abscess', 'urinary retention', 'anal stenosis' and 'fistula'. Consensus was reached to use 'reappearance of initial symptoms' as reported by the patient to define recurrence. During an additional short survey, consensus was reached that 'incontinence' should be assessed by the Wexner Fecal Incontinence Score, 'abscess' by physical examination, 'urinary retention' by ultrasonography, 'anal stenosis' by physical examination, and 'fistula' by physical examination and MR imaging if inconclusive. During follow‐up, the outcome 'symptoms' should be assessed at baseline, 7 days, 6 weeks and 1 year post‐procedure. The outcomes 'abscess' and 'urinary retention' should be assessed 7 days post‐procedure and 'incontinence', 'anal stenosis' and 'fistula' 1 year post‐procedure. Conclusions: We developed the first European Society of Coloproctology COS for HD based on an international Delphi study among healthcare professionals. The next step is to incorporate the patients' perspective in the COS. Use of this COS may improve the quality and uniformity of future research and enhance the analysis of evidence. [ABSTRACT FROM AUTHOR]

The electrical permittivity of soil is a function of the water content, which facilitates water content measurements. The permittivity of soil is also a function of the frequency of the applied electric field. This frequency dependence can be described by the relationship between the dielectric relaxation frequency and the activation enthalpy of the water, which in turn is related to the soil matric pressure. The activation enthalpy or soil matrix pressure is a measure of the binding forces acting on a water molecule in the soil matrix. Each water molecule is differently bound, varying from tightly bound to free water. The permittivity of the bulk soil results from the contribution of all the water molecules in the soil matrix. Therefore, the permittivity of soil as a function of frequency is related to the soil matrix pressure. It is realistic to consider hygroscopic water as ice like. A relatively sharp transition can be observed from free to hygroscopic water at matric pressure -- 100 MPa corresponding to relaxation frequency [f.sub.r] [approximately equals] 8 GHz. Therefore, for the interpretation of dielectric data using a dielectric mixture equation, the water content of soil can be split conveniently in 'free' water and 'hygroscopic' water.

A change in the relative proportions of the constituents of a porous material like soil will cause a change in its electrical permittivity. The measured permittivity reflects the impact of the permittivities of the individual material constituents. Numerous dielectric mixture equations are published, but none of these equations are generally applicable. A new theoretical mixture equation is derived, using the principle of superposition of electric (E) fields. This mixture equation relates the measured permittivity to a weighted sum of the permittivities of the individual material constituents and includes depolarization factors to account for electric field refractions at the interfaces of the constituents. The depolarization factors are related to physical properties of the material. Most other mixture equations contain one or more empirical factors. The concept of the depolarization factor is comparable with that of the 'shape factor' of particles as described by other authors. A special case of the new mixture equation, for which the depolarization factors equals one (no depolarizations), appeared equal to a mixture equation for fluids derived from using thermodynamics. The new mixture equation is compared with other mixture equations. Comparison of the new mixture equation with measured data for glass beads and fine sand was promising. Concluding, depolarization factors in the new mixture equation relate the microstructural and compositional material properties to the measured bulk permittivity of a material. Although not shown, depolarization factors can be calculated from physical material properties.