bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of chemically-cross-linked chitosan for the removal of Reactive Black 5 and Reactive Yellow 84 dyes from aqueous solutions
Authors: Filipkowska Urszula , Jóźwiak Tomasz
Published: October 2013

The study analyzed the sorption effectiveness of reactive dyes, Reactive Black 5 (RB5) and Reactive Yellow 84 (RY84), onto non-cross-linked chitosan beads (CHs) and onto CHs cross-linked with glutaraldehyde (ALD) i.e., ALD-CHs and epichlorohydrin (ECH) i.e., ECH-CHs. The study enabled determination of the optimal ratio of the cross-linking agent to chitosan and the optimal pH of the sorption process (from the range of 1:10–10:1, to 2–12, respectively). The time needed to reach the equilibrium concentration reached 504 h. Satisfactory effects of RB5 and RY84 sorption were achieved after 24 h sorption. Data were described with the heterogenous Langmuir’s model (double Langmuir’s equation). For RB5 dye, the most effective sorbent turned out to be CHs – the maximum sorption capacity reached 2025.11 (mg/g). For the other sorbents, ALD-CHs and ECH-CHs, the capacity accounted for 1797.0 mg/g and 1816.1 mg/g, respectively. In the case of RY84 dye, the most effective sorbent appeared to be ECH-CHs – 2234.3 mg/g. For CHs and ALD-CHs, the highest sorption capacities against RY84 reached 1774.2 and 2000.1 mg/g, respectively.
TNF-α Downregulates Inhibitory Neurotransmission through Protein Phosphatase 1-Dependent Trafficking of GABAAReceptors
Authors: Pribiag Horia , Stellwagen David
Published: October 2013

Inflammation has been implicated in the progression of neurological disease, yet precisely how inflammation affects neuronal function remains unclear. Tumor necrosis factor-α (TNFα) is a proinflammatory cytokine that regulates synapse function by controlling neurotransmitter receptor trafficking and homeostatic synaptic plasticity. Here we characterize the mechanisms through which TNFα regulates inhibitory synapse function in mature rat and mouse hippocampal neurons. Acute application of TNFα induces a rapid and persistent decrease of inhibitory synaptic strength and downregulation of cell-surface levels of GABAARs containing α1, α2, β2/3, and γ2 subunits. We show that trafficking of GABAARs in response to TNFα is mediated by neuronally expressed TNF receptor 1 and requires activation of p38 MAPK, phosphatidylinositol 3-kinase, protein phosphatase 1 (PP1), and dynamin GTPase. Furthermore, TNFα enhances the association of PP1 with GABAAR β3 subunits and dephosphorylates a site on β3 known to regulate phospho-dependent interactions with the endocytic machinery. Conversely, we find that calcineurin and PP2A are not essential components of the signaling pathway and that clustering of the scaffolding protein gephyrin is only reduced after the initial receptor endocytosis. Together, these findings demonstrate a distinct mechanism of regulated GABAAR endocytosis that may contribute to the disruption of circuit homeostasis under neuroinflammatory conditions.
Selective and Invariant Neural Responses to Spoken and Written Narratives
Authors: Regev Mor , Honey Christopher J. , Simony Erez , Hasson Uri
Published: October 2013

Linguistic content can be conveyed both in speech and in writing. But how similar is the neural processing when the same real-life information is presented in spoken and written form? Using functional magnetic resonance imaging, we recorded neural responses from human subjects who either listened to a 7 min spoken narrative or read a time-locked presentation of its transcript. Next, within each brain area, we directly compared the response time courses elicited by the written and spoken narrative. Early visual areas responded selectively to the written version, and early auditory areas to the spoken version of the narrative. In addition, many higher-order parietal and frontal areas demonstrated strong selectivity, responding far more reliably to either the spoken or written form of the narrative. By contrast, the response time courses along the superior temporal gyrus and inferior frontal gyrus were remarkably similar for spoken and written narratives, indicating strong modality-invariance of linguistic processing in these circuits. These results suggest that our ability to extract the same information from spoken and written forms arises from a mixture of selective neural processes in early (perceptual) and high-order (control) areas, and modality-invariant responses in linguistic and extra-linguistic areas.
Blockade of Toll-Like Receptor 4 Attenuates Morphine Tolerance and Facilitates the Pain Relieving Properties of Morphine
Authors: Eidson Lori N. , Murphy Anne Z.
Published: October 2013

The ventrolateral periaqueductal gray (vlPAG) is an integral locus for morphine action. Although it is clear that glia contribute to the development of morphine tolerance, to date, the investigation of their role has been limited to spinal and medullary loci. Opioids induce a neuroinflammatory response that opposes acute and long-term analgesia, thereby limiting their efficacy as therapeutic agents. Recent data suggest that the innate immune receptor Toll-like receptor 4 (TLR4), along with its coreceptor myeloid differentiation factor-2 (MD-2), mediates these effects. To date, the brain loci through which TLR4 modulates morphine tolerance have not been identified. We have previously demonstrated that chronic subcutaneous morphine results in tolerance that is accompanied by increases in vlPAG glial cell activity. Usingin vivopharmacological manipulations of vlPAG glia and TLR4 in the adult male rat, we show that intra-vlPAG administration of the general glial cell metabolic inhibitor propentofylline or the astrocyte activity inhibitor fluorocitrate attenuate tolerance to morphine. Characterization of MD-2 expression within the PAG revealed dense MD-2 expression throughout the vlPAG. Further, antagonizing vlPAG TLR4 dose dependently prevented the development of morphine tolerance, and vlPAG microinjections of TLR4 agonists dose dependently produced a “naive” tolerance to subsequent challenge doses of morphine. Finally, using a model of persistent inflammatory pain and pharmacological manipulation of TLR4 we demonstrate that systemic antagonism of TLR4 potentiated acute morphine antihyperalgesia. These results, together, indicate that vlPAG glia regulate morphine tolerance development via TLR4 signaling, and implicate TLR4 as a potential therapeutic target for the treatment of pain.
Graded Encoding of Food Odor Value in theDrosophilaBrain
Authors: Beshel Jennifer , Zhong Yi
Published: October 2013

Odors are highly evocative, yet how and where in the brain odors derive meaning remains unknown. Our analysis of theDrosophilabrain extends the role of a small number of hunger-sensing neurons to include food-odor value representation.In vivotwo-photon calcium imaging shows the amplitude of food odor-evoked activity in neurons expressing Drosophila neuropeptide F (dNPF), the neuropeptide Y homolog, strongly correlates with food-odor attractiveness. Hunger elevates neural and behavioral responses to food odors only, although food odors that elicit attraction in the fed state also evoke heightened dNPF activity in fed flies. Inactivation of a subset of dNPF-expressing neurons or silencing dNPF receptors abolishes food-odor attractiveness, whereas genetically enhanced dNPF activity not only increases food-odor attractiveness but promotes attraction to aversive odors. Varying the amount of presented odor produces matching graded neural and behavioral curves, which can function to predict preference between odors. We thus demonstrate a possible motivationally scaled neural “value signal” accessible from uniquely identifiable cells.
Superficially Projecting Principal Neurons in Layer V of Medial Entorhinal Cortex in the Rat Receive Excitatory Retrosplenial Input
Authors: Czajkowski Rafał , Sugar Jørgen , Zhang Sheng-Jia , Couey Jonathan J. , Ye Jing , Witter Menno P.
Published: October 2013

Principal cells in layer V of the medial entorhinal cortex (MEC) have a nodal position in the cortical–hippocampal network. They are the main recipients of hippocampal output and receive inputs from several cortical areas, including a prominent one from the retrosplenial cortex (RSC), likely targeting basal dendrites of layer V neurons. The latter project to extrahippocampal structures but also relay information to the superficial layers of MEC, closing the hippocampal–entorhinal loop. In the rat, we electrophysiologically and morphologically characterized RSC input into MEC and conclude that RSC provides an excitatory input to layer V pyramidal cells. Ultrastructural analyses of anterogradely labeled RSC projections showed that RSC axons in layer V of MEC form predominantly asymmetrical, likely excitatory, synapses on dendritic spines (90%) or shafts (8%), with 2% symmetrical, likely inhibitory, synapses on shafts and spines. The overall excitatory nature of the RSC input was confirmed by an optogenetic approach. Patterned laser stimulation of channelrhodopsin-expressing presynaptic RSC axons evoked exclusively EPSPs in recorded postsynaptic layer V cells. All responding layer V pyramidal cells had an axon extending toward the white matter. Half of these neurons also sent an axon to superficial layers. Confocal imaging of RSC synapses onto MEC layer V neurons shown to project superficially by way of retrogradely labeling from superficial layers confirmed that proximal dendrites of superficially projecting cells are among the targets of inputs from RSC. The excitatory RSC input thus interacts with both entorhinal–cortical and entorhinal–hippocampal circuits.
Where Pain Meets Action in the Human Brain
Authors: Perini Irene , Bergstrand Simon , Morrison India
Published: October 2013

Pain's complex influence on behavior implies that it involves an action component, although little is known about how the human brain adaptively translates painful sensations into actions. The consistent activation of premotor and motor-related regions during pain, including the midcingulate cortex (MCC), raises the question of whether these areas contribute to an action component. In this fMRI experiment, we controlled for voluntary action-related processing during pain by introducing a motor task during painful or nonpainful stimulation. The MCC (particularly the caudal cingulate motor zone [CCZ]), motor cortex, thalamus, and cerebellum responded during action regardless of pain. Crucially, however, these regions did not respond to pain unless an action was performed. Reaction times were fastest during painful stimulation and correlated with CCZ activation. These findings are consistent with the results of an activation likelihood estimate meta-analysis in which activation across experiments involving pain, action execution, or action preparation (with a total of 4929 subjects) converged in a similar network. These findings suggest that specific motor-related areas, including the CCZ, play a vital role in the control and execution of context-sensitive behavioral responses to pain. In contrast, bilateral insular cortex responded to pain stimulation regardless of action.
Risk Prediction Error Coding in Orbitofrontal Neurons
Authors: O'Neill Martin , Schultz Wolfram
Published: October 2013

Risk is a ubiquitous feature of life. It plays an important role in economic decisions by affecting subjective reward value. Informed decisions require accurate risk information for each choice option. However, risk is often not constant but changes dynamically in the environment. Therefore, risk information should be updated to the current risk level. Potential mechanisms involve error-driven updating, whereby differences between current and predicted risk levels (risk prediction errors) are used to obtain currently accurate risk predictions. As a major reward structure, the orbitofrontal cortex is involved in coding key reward parameters such as reward value and risk. In this study, monkeys viewed different visual stimuli indicating specific levels of risk that deviated from the overall risk predicted by a common earlier stimulus. A group of orbitofrontal neurons displayed a risk signal that tracked the discrepancy between current and predicted risk. Such neuronal signals may be involved in the updating of risk information.
Comparative study of viability measurement methods in crop plants
Authors: Gondor O. , Janda T. , Szalai G.
Published: October 2013

The aim of the present study was to find the best way of measuring the viability of root and leaf samples from various plant species (pea, wheat and maize) exposed to different concentrations of the heavy metal Cd. A comparison was made of three viability tests, namely electrolyte leakage measurements, and TTC and NBT reduction. The results suggested that electrolyte leakage was the most useful method for measuring leaf viability, being simple, fast, reliable and reproducible. The TTC reduction measurement proved the most useful for maize roots, while NBT reduction was the best method for detecting the viability of pea and wheat roots.
Dancing, skating and sex
Authors: Jones Rodney H.
Published: October 2013

This paper explores the relationship between discourse and action in practices involved in making and consuming texts. Texts are produced through the process of ‘entextualization’ in which strips of action and discourse are extracted from their original contexts and recontextualized into other situations. Different technologies for turning actions into texts affect the kinds of social actions and social identities that are made possible both at moments of entextualization and at future moments of recontextualization. In particular, I focus on how digital technologies affect the practices and participation structures around entextualization. Digital photography and video have had a profound effect on social practices and relationships around the making of texts. Specifically, they have made processes of entextualization more immediate, more contingent and more communal. Implications of these features of digital text making are discussed in light of previous work on literacy and orality.
Tempo, Auftakt, levels of actions, and practice
Authors: Norris Sigrid
Published: October 2013

This article builds on Scollon’s work on rhythm in ordinary talk (1981, 1982) and mediated discourse analysis (primarily 1998 and 2001) extending his work by utilizing multimodal interaction analysis (MIA) (Norris 2004) as the methodological framework. With multimodal transcripts of everyday interactions from grooming a horse to a workplace interaction and two boys painting Easter eggs, the article first illustrates Scollon’s notion of tempo, then discusses the new findings of Auftakt (offbeat or prelude taken from musicology) and that rhythm in chains of lower-level action may cross modal boundaries, before investigating a micro-medium-macro link. This micro-medium-macro link in everyday interaction is then explored through the analysis of the complexity of rhythm in everyday interaction by analysing an example of a father playing ball with his two-year old son. Here, it is demonstrated how multimodal rhythms are superimposed from chains of lower-level actions to chains of higher-level actions and to practices. Further, these superimposed rhythms are shown to take on a different tempo at each level. The article ends with the claim that rhythm, as Scollon thought, to a large extent structures ordinary interaction; but, as discussed throughout, and Scollon would have agreed, it is MIA that allows us to analyse the multimodal complexity.
Cutaneous metastasis from internal carcinomas: a review of 45 years
Authors: Sittart Jose Alexandre de Souza , Senise Monica
Published: October 2013

BACKGROUND: cutaneous metastases are not so frequent and in the medical literature there are several communications of isolated cases, thereby we decided to continue our study initiated in 1981 (45 years).OBJECTIVE: our objective is to present the research and review of cutaneous metastases of 45 years through our archives at Hospital do Servidor Publico Estadual de Sao Paulo. METHODS: the data were collected from clinical cases registered in our archives at anatomopathology department.RESULTS: since 1963 we have registered 209 patients with cutaneous metastases being the anterior thorax region the most affected area and in second place the abdominal region. Breast cancer was responsible for most of the cases in women and the lung in men.CONCLUSION: this study represents a signioficant number of cases in medical practice because skin metastases of internal carcinomas rarely are observed and the great predominance, mainly due of his origin were represented by adenocarcinomas.
Hereditary angioedema type III (estrogen-dependent) report of three cases and literature review*
Authors: Miranda Amanda Rodrigues , Ue Ana Paula Fusel de , Sabbag Dominique Vilarinho , Furlani Wellington de Jesus , Souza Patricia Karla de , Rotta Osmar
Published: October 2013

In this article, three cases of hereditary angioedema (HAE) type III (estrogen-dependent or with normal C1 inhibitor) are reported. The HAE was initially described in women of the same family in association with high-leveled estrogenic conditions such as the use of oral contraceptives and pregnancy. There is no change in the C1 inhibitor as happens in other types of hereditary angioedema, and mutations are observed in the encoding gene of the XII factor of coagulation in several patients. The current diagnosis is mainly clinical and treatment consists in the suspension of the triggering factors and control of acute symptoms. A brief review of physiopathology, clinical features, genetic alterations and treatment are also presented.
Off-label use of rituximab in dermatology: pemphigus treatment
Authors: Bomm Lislaine , Fracaroli Tainá Scalfoni , Sodré João Luz , Bressan Aline , Gripp Alexandre Carlos
Published: October 2013

Since its approval in 1997 by the FDA (United States Food and Drug Administration), rituximab has been used for certain B-cell lymphomas and treatment-resistant rheumatoid arthritis. Nevertheless, over the past 14 years, many case reports have demonstrated the efficacy of off-label rituximab in several dermatological inflammatory conditions. This study describes two cases of pemphigus vulgaris and two cases of pemphigus foliaceous that were treated with rituximab at 375 mg/m2 once a week for 4 weeks, and that responded well to treatment.
Breast carcinoma en Cuirasse - case report
Authors: Oliveira Gabriela Mantovanelli de , Zachetti Daniele Bueno Carvalho , Barros Hugo Rocha , Tiengo Adriana , Romiti Ney
Published: October 2013

Cutaneous metastasis is a phenomenon that results from a tumor spreading via lymphatic or vascular embolization, direct implant during surgery or skin involvement by contiguity. The primary malignant tumor that most commonly metastasizes to the skin in women is breast cancer, which can be manifested through papulonodular lesions, erysipeloid or sclerodermiform infiltration, en cuirasse. We report the case of a female patient, 78 years old, with papular, scaly and confluent lesions in the right breast for one year, progressing to edema and skin infiltration, reduction of breast volume and plaque en cuirasse, and similar lesions in the contralateral breast and abdomen for four months. The pathological diagnosis was invasive ductal breast carcinoma with Paget-like foci, epidermal skin metastases and lymphatic embolization.
Linear IgA dermatosis associated with ulcerative colitis: complete and sustained remission after total colectomy
Authors: Vargas Thiago Jeunon de Sousa , Fialho Mônica , Santos Luiza Tavares dos , Rodrigues Palmira Assis de Jesus Barreto , Vargas Ana Luisa Bittencourt Sampaio Jeunon , Sousa Maria Auxiliadora Jeunon
Published: October 2013

Linear IgA dermatosis has been increasingly associated with inflammatory bowel diseases, particularly ulcerative colitis. A 13-year-old male patient with an 11-month history of ulcerative colitis developed vesicles, pustules and erosions on the skin of the face, trunk and buttocks and in the oral mucosa. The work-up revealed a neutrophil-rich sub-epidermal bullous disease and linear deposition of IgA along the dermoepidermal junction, establishing the diagnosis of linear IgA dermatosis. The patient experienced unsatisfactory partial control of skin and intestinal symptoms despite the use of adalimumab, mesalazine, prednisone and dapsone for some months. After total colectomy, he presented complete remission of skin lesions, with no need of medications during two years of follow-up. A review of previously reported cases of the association is provided here and the role of ulcerative colitis in triggering linear IgA dermatosis is discussed.
Dermatoscopic findings in telangiectasia macularis eruptiva perstans
Authors: Unterstell Natasha , Lavorato Fernanda Guedes , Nery Natalia Solon , Mann Danielle , Alves Maria de Fatima Scotelaro Guimaraes , Barcaui Carlos
Published: October 2013

Telangiectasia macularis eruptiva perstans is a rare form of cutaneous mastocytosis, characterized by the presence of erythematous or yellowish-brown macules with telangiectasias, preferably located on the trunk and upper limbs. We have described a case of telangiectasia macularis eruptiva perstans focusing on the dermoscopic characteristics of this disease.
Treatment of HIV-associated facial lipoatrophy: impact on infection progression assessed by viral load and CD4 count
Authors: Soares Flávia Machado Gonçalves , Costa Izelda Maria Carvalho
Published: October 2013

BACKGROUND: HIV/AIDS-Associated Lipodystrophy Syndrome includes changes in body fat distribution, with or without metabolic changes. The loss of fat from the face, called facial lipoatrophy, is one of the most stigmatizing signs of the syndrome.OBJECTIVES:To evaluate the effect of FL treatment using polymethylmethacrylate (PMMA) implants on disease progression, assessed by viral load and CD4 cell count.METHODS: This was a prospective study of 44 patients treated from July 2009 to December 2010. Male and female patients, aged over 18 years, with clinically detectable FL and who had never been treated were included in the study. PMMA implantation was done to fill atrophic areas. Laboratory tests were conducted to measure viral load and CD4 count before and after treatment.RESULTS: Of the 44 patients, 72.72% were male and 27.27% female, mean age of 44.38 years. Before treatment, 82% of patients had undetectable viral load, which increased to 88.6% after treatment, but without statistical significance (p = 0.67). CD4 count before treatment ranged from 209 to 1293, averaging 493.97. After treatment, the average increased to 548.61. The increase in CD4 count after treatment was statistically significant with p = 0.02.CONCLUSION: The treatment of FL with PMMA implants showed a statistically significant increase in CD4 count after treatment, revealing the impact of FL treatment on disease progression. Viral load before and after treatment did not vary significantly.
Spatial Averaging of van Genuchten Hydraulic Parameters for Steady‐State Flow in Heterogeneous Soils: A Numerical Study
Authors: Zhu Jianting , Mohanty Binayak P.
Published: October 2013

For meso‐ or regional‐scale Soil–Vegetation–Atmosphere Transfer (SVAT) schemes in hydroclimatic models, pixel dimensions may range from several hundred square meters to several hundred square kilometers. Pixel‐scale soil hydraulic parameters and their accuracy are critical for the success of hydroclimatic and soil hydrologic models. This study tries to answer a major question: What will be the effective and average hydraulic properties for the entire pixel (or footprint of a remote sensor) consisting of several textures if the soil hydraulic properties can be estimated for each individual texture? In this study, we examined the impact of areal heterogeneity in soil hydraulic parameters on soil ensemble behavior for steady‐state evaporation and infiltration. Using the widely used van Genuchten model and hydraulic parameter statistics obtained from neural network–based pedotransfer functions (PTFs) for various soil textural classes, we address the impact of areal hydraulic property heterogeneity on ensemble behavior and uncertainty in steady‐state vertical flow in large‐scale heterogeneous fields. The various averaging schemes of van Genuchten parameters are compared with “effective parameters” calculated by conceptualizing the areally heterogeneous soil formation as an equivalent homogeneous medium that will discharge approximately the same amount of ensemble flux of the heterogeneous soil. The impact of boundary conditions and parameter correlation on the effective parameters, as well as the accuracy and uncertainty of the averaging schemes for the hydraulic parameters, are investigated and discussed. In light of our results, we suggest the following guidelines for van Genuchten hydraulic parameter averaging: arithmetic means for Ks and n, a value between arithmetic and geometric means for α when Ks and α are highly correlated, and a value between geometric and harmonic means for α when Ks and α are poorly correlated.
SHAFT‐MOUNTED TIME DOMAIN REFLECTOMETRY PROBE FOR WATER CONTENT AND ELECTRICAL CONDUCTIVITY MEASUREMENTS
Authors: Persson Magnus , Wraith Jon M.
Published: October 2013

A new shaft‐mounted time domain reflectometry (TDR) probe design is described and evaluated. In contrast to previous shaft‐mounted TDR probes (SMPs), the new design may be used to measure both dielectric constant (Ka) and bulk electrical conductivity (σa). Two SMP prototypes, 0.03 and 0.04 m long and having diameters of 0.006 m, were evaluated. The probes were calibrated in several fluids having different Ka and σa A primary advantage of the SMP is minimal physical probe length without sacrificing accuracy of Ka readings. Accuracy of Ka measurements for the new probes was similar to that of standard 0.20‐m‐long three‐rod probes.
Measuring Soil Water Content with Ground Penetrating Radar: A Review
Authors: Huisman J. A. , Hubbard S. S. , Redman J. D. , Annan A. P.
Published: October 2013

We present a comprehensive review of methods to measure soil water content with ground penetrating radar (GPR). We distinguish four methodologies: soil water content determined from reflected wave velocity, soil water content determined from ground wave velocity, soil water content determined from transmitted wave velocity between boreholes, and soil water content determined from the surface reflection coefficient. For each of these four methodologies, we discuss the basic principles, illustrate the quality of the data with field examples, discuss the possibilities and limitations, and identify areas where future research is required. We hope that this review will further stimulate the community to consider ground penetrating radar as one of the possible tools to measure soil water content.
Monitoring Temporal Development of Spatial Soil Water Content Variation: Comparison of Ground Penetrating Radar and Time Domain Reflectometry
Authors: Huisman J. A. , Snepvangers J. J. J. C. , Bouten W. , Heuvelink G. B. M.
Published: October 2013

We compare the capability of ground penetrating radar (GPR) and time domain reflectometry (TDR) to assess the temporal development of spatial variation of surface volumetric water content. In the case of GPR, we measured surface water content with the ground wave, which is a direct wave between the sender and receiver through the upper centimeters of the soil. Spatial water content variation was measured on 18 d with GPR and TDR during a 30‐d monitoring period. To ensure large fluctuations in the spatial water content variation, we created a heterogeneous pattern of water content by irrigation on 2 d. The temporal development of the spatial variation was studied by means of the variogram and interpolated water content maps. To compare GPR and TDR variograms, we estimated confidence intervals of the experimental variograms and the variogram model parameters with a jackknife approach and a first‐order approximation of model parameter uncertainty. The results showed that the 95% confidence intervals of the GPR experimental variogram were one to two orders of magnitude smaller than the 95% confidence intervals of the TDR experimental variogram because of the larger number of GPR measurements. Consequently, the uncertainty in the variogram model parameters was also much lower for GPR, which meant that the temporal development of the fitted GPR variogram model parameters was easier to interpret. Furthermore, the larger GPR measurement volume resulted in a low spatial nugget variance of 1 × 10−6to 1 × 10−9(m3m−3)2because short distance variation was averaged. This meant that GPR accurately measured spatial correlation lengths, even in the case of low water content variation. Interpolated maps showing the increase of water content due to irrigation and the subsequent gradual drying of the soil were more accurate and reproducible for GPR. It was concluded that the noninvasive GPR measurements provide the means to accurately and consistently monitor the development of spatial water content variation in time.
Conjunctive Use of Tension Infiltrometry and Time‐Domain Reflectometry for Inverse Estimation of Soil Hydraulic Properties
Authors: Schwartz R. C. , Evett S. R.
Published: October 2013

Infiltration from a tension disc infiltrometer can be applied conjointly with time‐domain reflectometry (TDR) measurements of soil water content to improve estimates of field hydraulic parameters. However, interpretation of TDR‐measured water contents for use in inverse optimizations may be problematic when rods are partially within the wetted zone. The objective of this study was to assess if TDR‐measured soil water contents in addition to cumulative infiltration could improve parameter estimability for the inverse optimization problem. Infiltration experiments were conducted with a 0.58‐m‐diam. cylinder packed with a loamy sand. Three trifilar TDR probes were inserted diagonally into the soil to measure transient water contents during infiltration. Inverse optimizations utilized cumulative infiltration, water contents from diagonally placed TDR probes, and a branch of the wetting water characteristic θ(h) from extracted soil cores. Measured θ(h) at one or more pressure heads was required in optimizations to provide a satisfactory description of the water characteristic in the dry region. Optimizations for three infiltration experiments yielded similar parameter estimates with overlapping 95% confidence intervals. The use of diagonal TDR‐measured water contents improved the predicted redistribution of soil water and decreased covariances between parameter pairs that led to better parameter estimability. Optimized simulations predicted water contents in a three‐dimensional region within 0.03 m3 m−3 of values measured by buried horizontal TDR probes. Parameter estimates were relatively insensitive to changes in the assumed averaging depth transverse to TDR rods. For the diagonally placed probes, the dominant gradients in water content were in directions that minimized errors associated with assuming a uniform weighting of water content within the TDR sampling volume.
Field Evaluation of the Dual‐Probe Heat‐Pulse Method for Measuring Soil Water Content
Authors: Heitman J. L. , Basinger J. M. , Kluitenberg G. J. , Ham J. M. , Frank J. M. , Barnes P. L.
Published: October 2013

The dual‐probe heat‐pulse (DPHP) method is useful for measuring water content (θ) and change in water content (Δθ) near the soil surface. The method has been evaluated in laboratory and greenhouse experiments, but not in a field setting. Our objective was to test the DPHP method under field conditions and for a range of soil properties. Twenty‐five DPHP sensors and five monitoring stations were constructed and installed at five locations in northeastern Kansas to measure θ and Δθ at 3‐h intervals for 3 mo. In addition, θ was estimated by coupling Δθ measurements with independent measurements of θ obtained by soil sampling at sensor installation. Additional soil samples were collected from each location during the monitoring period to provide independent measurements of θ. Regression of DPHP and independent θ measurements revealed slight bias but substantial offset error (about 0.1 m3 m−3) in the DPHP method. The offset error could not be fully attributed to bias in any single input parameter, but could have been caused by a combination of biased parameters. Estimates of θ from Δθ measurements also revealed slight bias, but offset error was considerably smaller. Use of a published empirical calibration for DPHP sensors almost completely eliminated this bias and further reduced the offset error to approximately 0.01 m3 m−3 Thus, the Δθ approach combined with use of the empirical calibration appears to have practical utility.
Multi‐Functional Heat Pulse Probe for the Simultaneous Measurement of Soil Water Content, Solute Concentration, and Heat Transport Parameters
Authors: Mori Y. , Hopmans J. W. , Mortensen A. P. , Kluitenberg G. J.
Published: October 2013

Water, solute, and heat transport processes in soils are mutually interdependent as each includes convective water flow and each transport mechanism is partly controlled by fluid saturation, pore geometry, temperature, and other soil environmental conditions. Therefore, their measurement in approximately identical measurement locations and volume is essential for understanding transport phenomena in soils. We introduce a 2.7‐cm‐diameter multi‐functional heat pulse probe (MFHPP), which consists of a single central heater, four thermistors, and four electrodes (Wenner array) that together are incorporated in six 1.27‐mm‐o.d. stainless‐steel tubes. The bulk soil thermal properties and volumetric water content of Tottori Dune sand were determined from the measurement of the temperature response of all four thermistor sensors after application of an 8‐s heat pulse by the heater sensor. Simultaneously with the temperature measurements, the bulk soil electrical conductivity (ECb) was measured using the Wenner array, from which soil solution concentration (ECw) can be obtained after calibration. All measurements were taken during multistep outflow experiments, which also allowed estimation of the soil's hydraulic properties. We demonstrated that the MFHPP can effectively measure volumetric water content, thermal properties, and ECb, and can be used to indirectly estimate soil water fluxes at rates larger than 0.7 m d−1 in the sand.
Errors in Heat Flux Measurement by Flux Plates of Contrasting Design and Thermal Conductivity
Authors: Sauer T. J. , Meek D. W. , Ochsner T. E. , Harris A. R. , Horton R.
Published: October 2013

The thermal conductivity (λ) of soils may vary by a factor of about 4 for a range of field soil water contents. Measurement of soil heat flux (G) using a heat flux plate with a fixed λ distorts heat flow through the plates and in the adjacent soil. The objectives of this research were to quantify heat flow distortion errors for soil heat flux plates of widely contrasting designs and to evaluate the accuracy of a previously reported correction. Six types of commercially available heat flux plates with varying thickness, face area, and thermal conductivity (λm) were evaluated. Steady‐state laboratory experiments at flux densities from 20 to 175 W m−2 were completed in a large box filled with dry or saturated sand having λ of 0.36 and 2.25 W m−1 K−1 A field experiment compared G measured with pairs of four plate types buried at 6 cm in a clay soil with G determined using the gradient technique. The flux plates underestimated G in the dry sand by 2.4 to 38.5% and by 13.1 to 73.2% in saturated sand while in moist clay plate performance ranged from a 6.2% overestimate to a 71.4% underestimate. Application of the correction generally improved agreement between plate estimates and independent G measurements, especially when λ > λm, although most plate estimates were still significantly lower than the actual G Limitations of the correction procedure indicate that renewed effort should be placed on innovative sensor designs that avoid or minimize heat flow distortion and/or provide direct, in situ calibration capability.
Field Application of a Portable Air Permeameter to Characterize Spatial Variability in Air and Water Permeability
Authors: Iversen Bo V. , Moldrup Per , Schjønning Per , Jacobsen Ole H.
Published: October 2013

The saturated hydraulic conductivity (Ks) is an essential parameter for modeling water and chemical transport in the vadose zone. Since in situ measurements of Ks are complex and time‐consuming, indirect methods that are dependable, fast, and inexpensive with regard to assessing magnitude and spatial variability in Ks at the field scale are needed. In situ measurements of air permeability (ka,in situ) may fulfill these criteria. In this study, a portable insertion‐type air permeameter was used to measure ka,in situ in the Ap and B horizons at five agricultural field sites in Denmark with soil types ranging from sand to sandy loam. Around 100 ka,in situ measurements were performed within 2 d at each field site. The data showed spatial correlation in ka,in situ at three out of five sites, with correlation distances between 30 and >120 m. On the basis of additional laboratory measurements on large, undisturbed soil samples (6280 cm3), a log‐log linear relationship between air permeability (ka) measured at the actual soil‐water content (close to field capacity) and Ks was found. The Ks–ka relation was in agreement with an earlier predictive relationship based on undisturbed 100‐cm3 samples from nine other field sites. Using pedotransfer functions for Ks based only on soil texture yielded an unrealistic narrow range in predicted Ks values whereas pedotransfer functions based on ka,in situ yielded a more realistic prediction range. Measurements of ka,in situ constitute a promising indirect method for assessing spatial variability in Ks at the field scale.
Chromate Transport and Retention in Variably Saturated Soil Columns
Authors: Hutchison J. M. , Seaman J. C. , Aburime S. A. , Radcliffe D. E.
Published: October 2013

Most subsurface contamination passes through the unsaturated zone before reaching an aquifer; however, transport studies are often conducted under saturated conditions because of the difficulty in maintaining steady‐state flow. Chromate migration was measured in coarse‐textured, oxide‐rich sediment under different water contents using vacuum and centrifuge techniques to obtain a steady‐state unsaturated flow regime. Leaching solutions contained 0.5 or 1.0 mMCr(VI) and tritium in artificial groundwater. Breakthrough curves (BTCs) were modeled using CXTFIT assuming equilibrium conditions, since evaluation of data using a “two‐region” physical nonequilibrium model indicated that mobile water was >90% regardless of saturation level. Dispersivity increased nonlinearly with decreasing water content. Retardation (R) increased with decreasing water content, but water content had little effect on the distribution coefficient calculated fromR,Kd‐appThe averageKd‐appof all Cr(VI) experiments (water content range: 0.07–0.43 cm3cm−3) was 0.633 mL g−1, very similar to the distribution coefficient derived from batch equilibration,Kd(0.684 mL g−1). Though results in both transport systems were similar, average solute residence times in the vacuum system were 4 to 23 times longer than in the centrifuge system at comparable water contents. The centrifuge system column experiments could also be run over a greater range in volumetric water content (0.07–0.42 cm3cm−3) than the vacuum column system (0.23–0.43 cm3cm−3).
Wet‐End Deviations from Scaling of the Water Retention Characteristics of Fractal Porous Media
Authors: Hunt A. G. , Gee G. W.
Published: October 2013

A previous work investigated the dry‐end deviation from fractal scaling of water retention characteristics of a suite of 43 U.S. Department of Energy (USDOE) Hanford site soils in relationship with the vanishing of solute diffusion at a moisture content θt It was found that the deviation from fractal scaling of the water retention set on at a moisture content typically about 0.06 higher than the moisture content at which solute diffusion vanishes. Assuming that the vanishing of solute diffusion resulted from a lack of continuity of the water phase, we interpreted the deviation from fractal scaling in terms of a lack of water‐phase continuity rather than as a breakdown of the fractal model. Now the wet‐end deviations from fractal scaling of the same suite of soils are investigated. It is shown that the wet‐end moisture contents at which the deviation occurs are correlated with the critical volume fraction for percolation and with the dry‐end deviations. However, wet‐end deviations occur at moisture contents closer to full saturation than do dry‐end deviations from zero saturation. This contrast between the wet and dry ends of the water retention curve, h(θ), is suggested to be a result of the role of equilibration in the experimental determination of h(θ), and thus to be traceable to the much lower values of the hydraulic conductivity, K, at the dry end.
A Survey of Department of Energy–Sponsored Geophysical Research for Shallow Waste Site Characterization
Authors: Guillen Donna Post , Hertzog Russel C.
Published: October 2013

Subsurface contamination plagues many USDOE sites and threatens groundwater supplies. This survey discusses research sponsored by the DOE Environmental Management Science Program (EMSP) for geophysical characterization of the vadose zone at the Idaho National Engineering and Environmental Laboratory (INEEL) and other contaminated sites. Various types of geophysical imaging techniques are used to characterize the shallow subsurface, including electromagnetic (EM), ground‐penetrating radar (GPR), electrical, seismic, and nuclear magnetic resonance (NMR). Three common themes appear in the research surveyed in this article: (i) the development of high‐resolution imaging capabilities to capture important details of the heterogeneous nature of subsurface properties and processes, (ii) the coupling of nonintrusive survey geophysical measurements (e.g., electrical surveys) with detailed quantitative precise point‐sensor measurements (e.g., lysimeters and vapor‐port systems) or borehole (e.g., NMR, neutron‐based moisture, and geochemical tools) measurements to extend high‐precision knowledge away from the borehole, and finally (iii) the application of multiple geophysical methods to constrain the uncertainty in determining critical subsurface physical properties. Laboratory, field, theoretical, and computational studies are necessary to develop our understanding of the manner in which contaminants travel through the vadose zone. Applications of geophysical methods to various contaminated areas at the INEEL are given.
Evaporation Effects on Oxygen and Hydrogen Isotopes in Deep Vadose Zone Pore Fluids at Hanford, Washington
Authors: DePaolo Donald J. , Conrad Mark E. , Maher Katharine , Gee Glendon W.
Published: October 2013

Stable isotopes of O and H were measured in pore fluid extracted from a sediment core located in a relatively undisturbed area in the Hanford site near the S‐SX Tank Farms. Pore fluids from most of the 70‐m‐thick vadose zone section have δ18O values that are shifted to higher values than those for winter precipitation (and Columbia River water) by 3 to 4‰. The shift of δ18O and the δ18O‐δD slope of about 4 in the deep vadose zone pore fluids is attributed to partial evaporation during residence in the upper meter of the soil section. A model relating the isotopic shift to recharge and soil properties suggests that the shift should be inversely proportional to recharge, and larger for coarser soils with lower water retention. When applied to Hanford soils and precipitation patterns, the model predicts that vadose zone pore fluids at Hanford should typically be shifted by +2 to +6‰ in δ18O relative to the values in wet season precipitation, even for relatively high values of annual net infiltration (up to 100 mm yr−1 or 60% of annual precipitation). The model has implications for groundwater as well as vadose zone δ18O. The effects of vegetation are not included, so only upper limit values for the net infiltration flux can be inferred from vadose zone δ18O. The shifted δ18O of natural pore fluids allows identification of the presence of subsurface water that comes from industrial discharges at the Hanford site. An example is provided by a low δ18O, high water content horizon at a depth of 44 m in the core, which is interpreted as industrial water that was transported laterally above a capillary barrier as a result of a nearby, near‐surface point discharge that happened within the past 50 yr.
Preferential Transport of Soil Colloidal Particles: Physicochemical Effects on Particle Mobilization
Authors: Rousseau M. , Di Pietro L. , Angulo‐Jaramillo R. , Tessier D. , Cabibel B.
Published: October 2013

The quantification of particle transport through soil is of great importance for estimating the potential risk of adsorbing contaminants leaching into groundwater. In the present study, we investigated the mobilization of natural soil particles in an undisturbed soil column (diameter = 0.3 m, height = 0.66 m). We tested the effects of physicochemical properties of soil and infiltrating water on the mobilization and transport of soil particles. A square pulse of water was applied at the top of the column. Water was allowed to drain freely at the bottom of the column. We tested two rainfall intensities (11 and 23 mm h−1), three ionic strengths (10−5, 10−3, and 10−1 M), and two initial moisture contents (0.34 and 0.38 m3 m−3). For the whole set of infiltration experiments, the concentration of eluted particles was correlated with the drainage flow intensity, particularly during transient flow. Particle leaching during steady flow varied with the boundary and initial conditions. The highest mobilization of particles was observed for deionized water, the highest infiltration rate and the highest initial soil moisture content. Particle mobilization was limited for high ionic strength associated with the divalent cation Mg2+ During transient flow, mechanical detachment by hydrodynamic shear could lead to particle mobilization. During steady flow, the ionic strength of the incoming solution may alter the energy potential at the soil–water interface, and thus have an effect on the mobilization rate as well.
A Generalized Function of Wheat's Root Length Density Distributions
Authors: Zuo Qiang , Jie Feng , Zhang Renduo , Meng Lei
Published: October 2013

The root length density (RLD) is an important parameter to model water and nutrient movement in the vadose zone and to study soil–root–shoot–atmosphere interactions. However, it is difficult and time‐consuming to measure and determine RLD distributions accurately. Especially RLD distributions change with different soil environment, plant species, growing seasons, and climatic conditions. In this study, measured data sets of wheat RLD distributions were collected from the literature and transformed into normalized root length density (NRLD) distributions. A total of 610 values of wheat NRLD distributions were pooled together. These data showed a general trend, independent of soil environment, wheat species, growing seasons, and climates. A generalized function was established to characterize the NRLD distributions versus normalized root depths. To verify the generalized function, we measured RLD distributions of winter wheat (Triticum aestivum L.) using laboratory and field experiments for different soils, growing stages of wheat, atmospheric conditions, and water supplies. Using the generalized function, we predicted winter wheat RLD and compared the predicted results with the experimental data and with results using other NRLD functions. The comparison showed that the generalized function predicted RLD distributions more accurately than the other functions. Although simulated results of soil water dynamics in soil–wheat systems were similar for the different NRLD functions, the generalized function should be advantageous for applications that require accurate information of root development and distribution.