Search results for "retention"

Hydro-mechanical behaviour of a sandy silt from a river embankment

2020

The paper presents the results of an experimental campaign aimed at characterizing the hydro-mechanical behaviour of a sandy silt from a river embankment. Due to continuous river level fluctuations and changing climatic and environmental conditions, flood embankment materials experience frequent variations in degree of saturation and suction values. Such variations strongly impact the earthwork performance both in terms of seepage and stability conditions. For these reasons, a detailed characterization of the material behaviour in unsaturated conditions was carried out. Experiments were designed in order to highlight the response of the involved soil in terms of changes in matric suction an…

Artificial Neural Networks for Predicting the Water Retention Curve of Sicilian Agricultural Soils

2018

Modeling soil-water regime and solute transport in the vadose zone is strategic for estimating agricultural productivity and optimizing irrigation water management. Direct measurements of soil hydraulic properties, i.e., the water retention curve and the hydraulic conductivity function, are often expensive and time-consuming, and represent a major obstacle to the application of simulation models. As a result, there is a great interest in developing pedotransfer functions (PTFs) that predict the soil hydraulic properties from more easily measured and/or routinely surveyed soil data, such as particle size distribution, bulk density (&rho

Coupling of iron and dissolved organic matter in lakes–selective retention of different size fractions

2023

AbstractIncreasing concentration of iron (Fe) is observed in many boreal lakes, such as for the present study in Oslo Østmark, SE-Norway (1983–2018). As Fe-regulating processes are complex and dynamic, the link between mobilizing and retention processes is still not well understood. A seasonal study (2017–2018) from two headwaters, with medium and high dissolved organic matter (DOM) concentrations, showed that the loading of Fe to the lakes was highly dependent on flow conditions. Significantly higher values of Fe were related to autumn and winter periods with high runoff of highly colored and aromatic DOM compared to a severe drought period with minimum Fe values in the lakes. Compared to …

Using static and dynamic indicators to evaluate soil physical quality in a Sicilian area

2016

Both capacitive indicators derived from the water retention curve and dynamic measurements of the flow-weighted mean pore radius, R0, were used to assess the soil physical quality of two agricultural areas (cropland and olive orchard) and two natural areas (grassland and managed woodlot plantation) potentially subject to soil degradation. The overall idea of the study was to investigate whether a dynamic indicator quantitatively derived from hydraulic conductivity measurements could be used to supplement the traditionally applied capacitive indicators retrieved from water retention measurements. According to the available criteria, only the surface layer of the cropland site showed optimal …

Emergency surgery in a patient with large spontaneous spinal epidural hematoma determining excellent neurological recovery: Review of the literature

2014

Study design: Case report. Objectives: We report a case of a 75-year-old woman suffering from voluminous idiopathic spontaneous spinal epidural hematoma (SSEH) that was rapidly diagnosed and successfully treated. Methods: Clinical presentation was characterized by sudden and intense back pain that rapidly evolved into plegia of the right leg and severe paresis of the left leg. Hypoesthesia below T6 and urinary retention were also present. Magnetic resonance imaging showed a significant posterior spinal compression from T6 through L3 caused by an epidural hematoma that involved 10 metameric levels, extending for ∼20 cm, with a maximum thickness of 1.6 cm from T12 to L1. Results: Within 12 h,…

The impact of sacral root anatomy on selective electrical stimulation for bladder evacuation.

1998

Although different structures have been studied with electrostimulation to elicit bladder evacuation, only the sacral root remains feasible for clinical application at present. However, the resultant concomitant contractions of the bladder and sphincteric muscles have been the principal problem over the last few decades. Attempts to identify fibers within the sacral ventral root that innervate the detrusor predominantly have been made by microsurgery alone or in combination with advanced electrical blocking techniques. This article evaluates our past and present efforts to achieve voiding in light of the mixed nature of sacral root anatomy.

Oral local drug delivery and new perspectives in oral drug formulation

2012

Modern pharmaceutical science has provided us with a wide range of substances to be administered with a wide large variety of dosage forms. Local drug delivery systems have been used for a long time; in particular, for the local therapy of diseases affecting the oral cavity. Although these diseases are often extremely responsive to local therapy, the mouth often presents various difficulties in the application of topical compounds (owing to saliva and the mouth's different functions), resulting in a short retention time of dosage forms with a consequent low therapeutic efficacy. To resolve these limitations, research today concentrates on the development of bioadhesive formulations. This re…

Remember, know, confidence and the mirror effect: Changes as a function of discriminability conditions

2003

Recognition memory for Spanish-Catalan cognate and noncognate words was tested at retention intervals of 20 minutes, 1 hour, and 24 hours (Experiment 1) using a remember/know response procedure, and requiring a confidence judgement on the yes/no response. Noncognate words were accompanied by more “remember” responses than cognates, and overall A' was significantly different from remember A', except in the cognate condition at the longest retention interval. A strong mirror effect for the cognate-noncognate stimulus class was found for overall responding, and for high but not low confidence, indicating a differential use of recollection and familiarity in recognition. In general, the pattern…

Efficacy and acceptance of the sacral neuromodulation in the treatment of female lower urinary tract dysfunctions.

2017

[S1 Herpes zoster localization: acute urinary retention in woman].

2011

Acute urinary retention in women is rare. The varicella-zoster virus causes inflammatory lesions of the sensory-root ganglions, meninges and, less frequently, spinal cord. Herpes zoster has been reported to affect, although rarely, lower urinary tract innervations, and acute urinary retention can be thought to occur in the presence of sacral dermatome involvement. Usually it is located in S2–4 dermatome and the prognosis for acute urinary retention is benign resolving in about 20 days. We present a case in which the S1 dermatome was interested and acute urinary retention developed. After 10 days of specific therapy and self catheterism the problem resolved.