Organic Matter Fractions and Quality of the Surface Layer of a Constructed and Vegetated Soil After Coal Mining. II - Physical Compartments and Carbon Management Index

Soils constructed after mining often have low carbon (C) stocks and low quality of organic matter (OM). Cover crops are decisive for the recovery process of these stocks, improving the quality of constructed soils. Therefore, the goal of this study was to evaluate the effect of cover crops on total organic C (TOC) stocks, C distribution in physical fractions of OM and the C management index (CMI) of a soil constructed after coal mining. The experiment was initiated in 2003 with six treatments: Hemarthria altissima (T1), Paspalum notatum (T2), Cynodon dactylon (T3), Urochloa brizantha (T4), bare constructed soil (T5), and natural soil (T6). Soil samples were collected in 2009 from the 0.00-0.03 m layer, and the TOC and C stocks in the physical particle size fractions (carbon in the coarse fraction - CCF, and mineral-associated carbon - MAC) and density fractions (free light fraction - FLF; occluded light fraction - OLF, and heavy fraction - HF) of OM were determined. The CMI components: carbon pool index (CPI), lability (L) and lability index (LI) were estimated by both fractionation methods. No differences were observed between TOC, CCF and MAC stocks. The lowest C stocks in FLF and OLF fractions were presented by T2, 0.86 and 0.61 Mg ha-1, respectively. The values of TOC stock, C stock in physical fractions and CMI were intermediate, greater than T5 and lower than T6 in all treatments, indicating the partial recovery of soil quality. As a result of the better adaptation of the species Hemarthria and Brizantha, resulting in greater accumulation of labile organic material, the CPI, L, LI and CMI values were higher in these treatments, suggesting a greater potential of these species for recovery of constructed soils.

Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration

ABSTRACT Intrinsic equilibrium constants of 17 representative Brazilian Oxisols were estimated from potentiometric titration measuring the adsorption of H+ and OH− on amphoteric surfaces in suspensions of varying ionic strength. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. The former was fitted by calculating total site concentration from curve fitting estimates and pH-extrapolation of the intrinsic equilibrium constants to the PZNPC (hand calculation), considering one and two reactive sites, and by the FITEQL software. The latter was fitted only by FITEQL, with one reactive site. Soil chemical and physical properties were correlated to the intrinsic equilibrium constants. Both surface complexation models satisfactorily fit our experimental data, but for results at low ionic strength, optimization did not converge in FITEQL. Data were incorporated in Visual MINTEQ and they provide a modeling system that can predict protonation-dissociation reactions in the soil surface under changing environmental conditions.

Surface Complexation Modeling in Variable Charge Soils: Prediction of Cadmium Adsorption

ABSTRACT Intrinsic equilibrium constants for 22 representative Brazilian Oxisols were estimated from a cadmium adsorption experiment. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. Intrinsic equilibrium constants were optimized by FITEQL and by hand calculation using Visual MINTEQ in sweep mode, and Excel spreadsheets. Data from both models were incorporated into Visual MINTEQ. Constants estimated by FITEQL and incorporated in Visual MINTEQ software failed to predict observed data accurately. However, FITEQL raw output data rendered good results when predicted values were directly compared with observed values, instead of incorporating the estimated constants into Visual MINTEQ. Intrinsic equilibrium constants optimized by hand calculation and incorporated in Visual MINTEQ reliably predicted Cd adsorption reactions on soil surfaces under changing environmental conditions.

Potential of Spectroradiometry to Classify Soil Clay Content

ABSTRACT Diffuse reflectance spectroscopy (DRS) is a fast and cheap alternative for soil clay, but needs further investigation to assess the scope of application. The purpose of the study was to develop a linear regression model to predict clay content from DRS data, to classify the soils into three textural classes, similar to those defined by a regulation of the Brazilian Ministry of Agriculture, Livestock and Food Supply. The DRS data of 412 soil samples, from the 0.0-0.5 m layer, from different locations in the state of Rio Grande do Sul, Brazil, were measured at wavelengths of 350 to 2,500 nm in the laboratory. The fitting of the linear regression model developed to predict soil clay content from the DRS data was based on a R2 value of 0.74 and 0.75, with a RMSE of 7.82 and 8.51 % for the calibration and validation sets, respectively. Soil texture classification had an overall accuracy of 79.0 % (calibration) and 80.9 % (validation). The heterogeneity of soil samples affected the performance of the prediction models. Future studies should consider a previous classification of soil samples in different groups by soil type, parent material and/or sampling region.

Water-Stable Aggregates and Associated Carbon in a Subtropical Rice Soil Under Variable Tillage

ABSTRACT Tillage systems can influence C sequestration by changing aggregate formation and C distribution within the aggregate. This study was undertaken to explore the impact of no-tillage without straw (NT-S) and with straw (NT+S), and moldboard plow without straw (MP-S) and with straw (MP+S), on soil aggregation and aggregate-associated C after six years of double rice planting in a Hydragric Anthrosol in Guangxi, southwest of China. Soil samples of 0.00-0.05, 0.05-0.20 and 0.20-0.30 m layers were wet-sieved and divided into four aggregate-size classes, >2 mm, 2.00-0.25 mm, 0.25-0.053 and <0.053 mm, respectively, for measuring aggregate associated C and humic and fulvic acids. Results showed that the soil organic carbon (SOC) stock in bulk soil was 40.2-51.1 % higher in the 0.00-0.05 m layer and 11.3-17.0 % lower in the 0.05-0.20 m layer in NT system (NT+S and NT-S) compared to the MP system (MP+S and MP-S), respectively. However, no statistical difference was found across the whole 0.00-0.30 m layer. The NT system increased the proportion of >2 mm aggregate fraction and reduced the proportion of <0.053 mm aggregates in both 0.00-0.05 and 0.05-0.20 m layers. The SOC concentration, SOC stock and humic and fulvic acids within the >0.25 mm macroaggregate fraction also significantly increased in the 0.00-0.5 m layer in NT system. However, those within the 2.00-0.25 mm aggregate fraction were significantly reduced in the 0.05-0.200 m layer under NT system. Straw incorporation increased not only the SOC stock in bulk soil, but also the proportion of macroaggregate, aggregate associated with SOC and humic and fulvic acids concentration within the aggregate. The effect of straw on C sequestration might be dependent on the location of straw incorporation. In conclusion, the NT system increased the total SOC accumulation and humic and fulvic acids within macroaggregates, thus contributing to C sequestration in the 0.00-0.05 m layer.

Autofluorescence Study In NR2E3 p.G56R-linked Autosomal Dominant Retinitis Pigmentosa In A Single Kindred

Purpose: To date, the genotype/phenotype correlation of p.G56R-linked autosomal dominant retinitis pigmentosa (ADRP) is limited to less than 10 kindred. The purpose of this study is to report an unusual appearance of fundus autofluorescence (AF) with NR2E3 p.G56R-linked ADRP in a single kindred.Methods: Patients were enrolled among three generations in a previously unreported family. Molecular diagnosis was performed on all exons of NR2E3 and a p.G56R mutation was identified in affected family members only. Examinations included fundus photography, visual fields, optical coherence tomography, AF, near-infrared AF and ISCEV-standard electrophysiology (ERG).Results: Among 10 examined family members, 5 were affected. The youngest and oldest patients were 16 and 65 years old, respectively. Fundus examination revealed a range of retinal disorder from normal to optic nerve pallor, attenuated arterial caliber and bone spicule-like pigment deposits. In all patients, AF showed a double hyperfluorescent ring; an inner paramacular ring which extension was comparable among patients and an outer ring along the vascular arcades which extended towards periphery in older patients and became hypofluorescent. Maximal scotopic ERGs when recordable showed an increased a/b wave ratio.Conclusions: A double hyperfluorescent ring on AF is an uncommon observation and might be a specific clinical finding in NR2E3 p.G56R-linked ADRP. The consistency of that finding in all affected members of our 3-generation family confirms a previous study. Further analysis is required to determine whether AF changes are associated with particular retinal layer abnormalities.

Diffuse nesidioblastosis with hypoglycemia mimicking an insulinoma: a case report.

INTRODUCTION: We describe a case of diffuse nesidioblastosis in an adult patient who presented with exclusively fasting symptoms and a focal pancreatic 111In-pentetreotide uptake mimicking an insulinoma. CASE PRESENTATION: A 23-year-old Caucasian man had severe daily fasting hypoglycemia with glucose levels below 2mmol/L. Besides rare neuroglycopenic symptoms (confusion, sleepiness), he was largely asymptomatic. His investigations revealed low venous plasma glucose levels, high insulin and C-peptide levels and a 72-hour fast test that were all highly suggestive for an insulinoma. Abdominal computed tomography and magnetic resonance imaging did not reveal any lesions. The sole imagery that was compatible with an insulinoma was a 111In-somatostatin receptor scintigraphy that showed a faint but definite focal tracer between the head and the body of the pancreas. However, this lesion could not be confirmed by endoscopic ultrasonography of the pancreas. Following duodenopancreatectomy, the histological findings were consistent with diffuse nesidioblastosis. Postoperatively, the patient continued to present with fasting hypoglycemia and was successfully treated with diazoxide. CONCLUSION: In the absence of gastrointestinal surgery, nesidioblastosis is very rare in adults. In addition, nesidioblastosis is usually characterized by post-prandial hypoglycemia, whereas this patient presented with fasting hypoglycemia. This case also illustrates the risk for a false positive result of 111In-pentetreotide scintigraphy in the case of nesidioblastosis. Selective arterial calcium stimulation and venous sampling is the most reliable procedure for the positive diagnosis of insulinoma or nesidioblastosis and should be used to confirm any suspicion based on imaging modalities.

Double blind controlled trial of D-penicillamine in patients with primary biliary cirrhosis.

One hundred and eighty nine patients with primary biliary cirrhosis were entered into a double blind, placebo controlled randomised trial starting in January 1978 to assess the therapeutic value of d-penicillamine 1200 mg daily. Eighteen of the 98 patients receiving d-penicillamine and 22 of the 91 placebo treated patients died during the study. Thirty six per cent of those on d-penicillamine and 8% of those on placebo were withdrawn from the study. No difference in overall survival was noted between the two groups of patients whether the results were analysed for the entire period of observation or only during the period in which the patients were receiving therapy. The mortality rate of those receiving d-penicillamine in histological stage I to II, however, was one third of that of the placebo group although this difference did not reach statistical significance. Using the occurrence rate ratio as the statistical method of analysis, no effect of d-penicillamine was noted on any clinical, biochemical or hist

Chronic norovirus gastroenteritis in a double hematopoietic stem cell and lung transplant recipient.

N. Boillat Blanco, R. Kuonen, C. Bellini, O. Manuel, C. Estrade, J. Mazza-Stalder, J.D. Aubert, R. Sahli, P. Meylan. Chronic norovirus gastroenteritis in a double hematopoietic stem cell and lung transplant recipient. Transpl Infect Dis 2011: 13: 213-215. All rights reserved.

Regional and cellular patterns of reelin mRNA expression in the forebrain of the developing and adult mouse

The reelin gene encodes an extracellular protein that is crucial for neuronal migration in laminated brain regions. To gain insights into the functions of Reelin, we performed high-resolution in situ hybridization analyses to determine the pattern of reelin expression in the developing forebrain of the mouse. We also performed double-labeling studies with several markers, including calcium-binding proteins, GAD65/67, and neuropeptides, to characterize the neuronal subsets that express reelin transcripts. reelinexpression was detected at embryonic day 10 and later in the forebrain, with a distribution that is consistent with the prosomeric model of forebrain regionalization. In the diencephalon, expression was restricted to transverse and longitudinal domains that delineated boundaries between neuromeres. During embryogenesis,reelin was detected in the cerebral cortex in Cajal-Retzius cells but not in the GABAergic neurons of layer I. At prenatal stages, reelin was also expressed in the olfactory bulb, and striatum and in restricted nuclei in the ventral telencephalon, hypothalamus, thalamus, and pretectum. At postnatal stages, reelin transcripts gradually disappeared from Cajal-Retzius cells, at the same time as they appeared in subsets of GABAergic neurons distributed throughout neocortical and hippocampal layers. In other telencephalic and diencephalic regions,reelin expression decreased steadily during the postnatal period. In the adult, there was prominent expression in the olfactory bulb and cerebral cortex, where it was restricted to subsets of GABAergic interneurons that co-expressed calbindin, calretinin, neuropeptide Y, and somatostatin. This complex pattern of cellular and regional expression is consistent with Reelin having multiple roles in brain development and adult brain function.

Reelin regulates the development and synaptogenesis of the layer-specific entorhino-hippocampal connections

Here we examine the role of Reelin, an extracellular protein involved in neuronal migration, in the formation of hippocampal connections. Both at prenatal and postnatal stages, the general laminar and topographic distribution of entorhinal projections is preserved in the hippocampus of reeler mutant mice, in the absence of Reelin. However, developing and adult entorhinal afferents show severe alterations, including increased numbers of misrouted fibers and the formation of abnormal patches of termination from the medial and lateral entorhinal cortices. At perinatal stages, single entorhinal axons in reeler mice are grouped into thick bundles, and they have decreased axonal branching and decreased extension of axon collaterals. We also show that the number of entorhino-hippocampal synapses is lower in reeler mice than in control animals during development. Studies performed in mixed entorhino-hippocampal co-cultures combining slices from reeler and wild-type mice indicate that these abnormalities are caused by the lack of Reelin in the target hippocampus. These findings imply that Reelin fulfills a modulatory role during the formation of layer-specific and topographic connections in the hippocampus. They also suggest that Reelin promotes maturation of single fibers and synaptogenesis by entorhinal afferents.

Influence of ohmic heating on the flow field in thin-layer electrodeposition

In thin-layer electrodeposition the dissipated electrical energy leads to a substantial heating of the ion solution. We measured the resulting temperature field by means of an infrared camera. The properties of the temperature field correspond closely with the development of the concentration field. In particular, we find that the thermal gradients at the electrodes act similar to a weak additional driving force to the convection rolls driven by concentration gradients.