Assessing the extraction efficiency of CaCl2 and rhizon extraction methods after the application of organic matter and CaCl2 as soil amendments to enhance the mobility of Cd and Zn

A pot experiment was conducted to study the extractability of cadmium and zinc by CaCl 2 and rhizon extraction methods after the application of organic matter and chloride as soil amendments. Two methods, Rhizon and CaCl 2 extraction methods were concurrently employed to study the effects of the various amendments on the mobility of Cd and Zn. Both CaCl 2 and Rhizon extraction methods generally extracted appreciable amounts of the heavy metals after the application of the amendments. However, the results from the experiment shows that the Rhizon samplers extracted higher concentrations of both Cd and Zn as compared to the CaCl 2 extraction method. The use of rhizon soil moisture sampler is also non destructive to the soil and makes it possible to ascertain levels of heavy metals at equilibrium in the soil solution without changing the compisition of the soil solution in the process of extracting it. Assessment of the soil pH in the soil samples and the Rhizon extracts after the application of the amendments showed no significant difference with the control. Comparatively, application of CaCl 2 had a significant mobilizing effect on the mobility of both Cd and Zn as a result of the combined effect of complexation of Cd and Zn by the chloride anion, and by the fact that Cd and Zn are referentially absorbed in cation exchange positions. Therefore the Ca 2+ ion can displace these metals into the soil solution

Factors affecting metal mobilisation during oxidation of sulphidic, sandy wetland substrates

Most metals accumulate as sulphides under anoxic conditions in wetland substrates, reducing their bioavailability due to the solubility of metal sulphides. However, upon oxidation of these sulphides when the substrate is occasionally oxidised, metals can be released from the solid phase to the pore water or overlaying surface water. This release can be affected by the presence of carbonates, organic matter and clay. We compared changes of Cd, Cu and Zn mobility (CaCl2 extraction) during oxidation of a carbonate-rich and a carbonate-poor sulphidic, sandy wetland substrate. In addition, we studied how clay with low and high cation sorption capacity (bentonite and kaolinite, respectively) and organic matter (peat) can counteract Cd, Cu and Zn release during oxidation of both carbonate-rich and carbonate-poor sulphidic sediments. CaCl2-extractability of Cu, a measure for its availability, is low in both carbonate-poor and carbonate-rich substrates, whereas its variability is high. The availability of Cd and Zn is much higher and increases when peat is supplied to carbonate-poor substrates. A strong reduction of Cd and Zn extractability is observed when clay is added to carbonate-poor substrates. This reduction depends on the clay type. Most observations could be explained taking into account pH differences between treatments, with kaolinite resulting in a lower pH in comparison to bentonite. These pH differences affect the presence and characteristics of dissolved organic carbon and the metal speciation, which in turns affects the interaction of metals with the solid soil phase. In carbonate-rich substrates, Cd and Zn availability is lower and the effects of peat and clay amendment are less clear. The latter can also be attributed to the high pH and lack of pH differences between treatments

Randomised clinical trial: the long‐term safety and tolerability of naloxegol in patients with pain and opioid‐induced constipation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108643/1/apt12899.pd

Perturbative Expansion around the Gaussian Effective Potential of the Fermion Field Theory

We have extended the perturbative expansion method around the Gaussian effective action to the fermionic field theory, by taking the 2-dimensional Gross-Neveu model as an example. We have computed both the zero temperature and the finite temperature effective potentials of the Gross-Neveu model up to the first perturbative correction terms, and have found that the critical temperature, at which dynamically broken symmetry is restored, is significantly improved for small value of the flavour number.Comment: 14pages, no figures, other comments Typographical errors are corrected and new references are adde

Radiation dose optimization in thoracic imaging

Guidelines for reduction of CT radiation dose were introduced in 1997 and are now more than 12 years old. The process initiated by the European Regulatory authorities to reduce the excess of radiation from CT has however not produced the expected results. Reference diagnostic levels (DRL) from surveys are still twice as high as needed in most European countries and were not significantly reduced as compared to the initial European ones. Many factors may at least explain partially the lack of dose reduction. One of them is the complexity of the dose optimization process while maintaining image quality at a diagnostically acceptable level. Chest is an anatomical region where radiation dose could be substantially reduced because of high natural contrasts between structures, such as air in the lungs and fat in the mediastinum. In this article, the concept of CT radiation dose optimization and the factors that contribute to maintain global excess in radiation dose are reviewed and a brief summary of results from research in the field of chest CT radiation dose is given

DIFFERENCES IN GAIT DYNAMICS AMONG VARIOUS TYPES OF SHOE

INTRODUCTION: The foot provides an important source of feedback for locomotion (Nurse et al., 2005). The healthy locomotor system integrates input from the neuronal system as well as feedback from visual, vestibular and proprioceptive sensors (Hausdorff, 2007). Shoe constructions can support altering gait mechanics and/or stability training (Nigg et al., 2006). Particularly, feedback from the feet may be influenced by changing the types of shoe. According to recent studies, gait variability, such as stride-to-stride fluctuation, may be a biomechanical marker for changes of gait mechanics (Hausdorff, 2007; Peng et al., 1995). The study of gait variability offers a complementary way of quantifying locomotion and its changes with aging and disease as well as a means of monitoring the effects of therapeutic interventions and rehabilitation (Hausdorff, 2007). Then, usually temporal (stride interval time, swing interval time, stance interval time, step interval time, double support time) and spatial (stride length, step length, step width) variables were used for variability analysis. Thus, analyses for gait variability were so-called “gait dynamics“. And types of shoe may cause changes of gait performance during walking. In present study we would like to identify differences of gait dynamics (from variability point of views) between shoe types during treadmill walking

A STUDY ON GAIT PATTERN BETWEEN OLD AND YOUNG ADULTS TO EVALUATE ELDERLY SHOE: PRELIMINARY STUDY

INTRODUCTION: There are differences between gait performance of old and that of young adults (Paroczai, 2006). It is believed that these differences might have effects on the developmental procedure of shoes for the elderly. However the standard of elderly shoe for development and evaluation is not enough. Traditional gait analysis methods (kinematics and kinetics) and gait variability were used. Gait variability can offer a complementary way of quantifying locomotion and its changes with aging and disease as well as a means of monitoring the effects of therapeutic interventions and rehabilitation (Hausdorff, 2007). Especially, according to recent studies, variability was closely related to gait stability (Hausdorff, 2007). The goal of this study was to find elderly gait pattern for evaluating elderly shoe based on stability point of view

Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments

Background: The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus. Methods: We sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent. Results: During summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro- and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks and their hosts and hence the transmission likelihood.[br/] Conclusions: Diluting effects of more diverse habitat patches would pose another reason to maintain or restore high biodiversity in forest patches of rural landscapes. We suggest classifying habitat patches by their regulating services as dilution and amplification habitat, which predominantly either decrease or increase B. burgdorferi prevalence at local and landscape scale and hence LB risk. Particular emphasis on promoting LB-diluting properties should be put on the management of those habitats that are frequently used by humans. In the light of these findings, climate change may be of little concern for LB risk at local scales, but this should be evaluated further

Dosimetry: which dose for screening, diagnosis and follow-up ?

The question of which dose for screening, diagnosing ad follow-up of pulmonary nodules is a permanent issue for radiologists and radiotherapists. The proposed dose values for 2013 reflect the possibilities of the latest CT generations, from 2010 or later and include all technical novelties such as iterative reconstructions, automatic tube potential selection, and latest detectors. As the technology is constantly evolving, these parameters are susceptible to lower every year