bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tree root mounds and their role in transporting soil on forested landscapes
Authors: Hoffman Benjamin S. S. , Anderson Robert S. 
Published: July 2013

ABSTRACTThe growth and decay of tree roots can stir and transport soil. This is one process that contributes to the mass‐movement of soil on hillslope. To explore the efficiency of this process, we document the mounding of soil beside Ponderosa and Lodgepole pine trees in the forests that dominate the mid‐elevations of Colorado's Boulder Creek watershed. Mounds are best expressed around Ponderosa pines, reaching vertical displacements above the far‐field slopes of order 10–20 cm, fading into the slope by roughly 100 cm distance from the trunks with common diameters of 30 cm. Positive mounding occurs on all sides of trees on slopes, indicating that the mounding is not attributable to deflection of a creeping flow of soil around the tree, but rather to the insertion of root volume on all sides in the subsurface. Mounding is commonly asymmetric even on cross‐slope profiles. Significant variation in the mound sizes results in no clear relationship between tree diameter and root volume displaced. These observations motivated the development of a discrete element model of tree root growth using the LIGGGHTS model, in which grains we specified to be ‘root cells’ were allowed to enlarge within the simulated granular matrix. Mounding could be reproduced, with the majority of the vertical displacement of the surface being attributable to reduction of the bulk density due to dilation of the granular matrix during root enlargement. Finally, we develop a previous analysis of the role of roots in transporting soil during growth and decay cycles. We find that even in shallow soils, the root‐cycle can drive significant soil transport down forested montane slopes. Copyright © 2013 John Wiley & Sons, Ltd.
Comparative Performance Analysis of Anode‐Supported Micro‐Tubular SOFCs with Different Current‐Collection Architectures
Authors: De la Torre R. , Avila‐Paredes H. J. , Sglavo V. M. 
Published: July 2013

AbstractIn this study, the performances of single micro‐tubular solid oxide fuel cells based on the NiO–YSZ/YSZ/LSM system with two different current‐collection architectures were compared. In the first case, a straight Ni wire was inserted within the hole of the cell before the electrochemical testing, and in the second case, a coil integrated‐current collector within the anode layer was already arranged for electrical connections during cell processing. The current produced in each case was collected from double terminal and the performance of the cells was estimated by electrochemical I–V characterization. The maximum power outputs generated in the cells with the integrated‐current collector and the common current‐collection architectures were of ∼200 and ∼55 mW cm–2, respectively at 800 °C under a wet H2 fuel flow.
Localized refractory dissolved organic carbon sinks in the deep ocean
Authors: Hansell Dennis A. , Carlson Craig A. 
Published: July 2013

AbstractThe global ocean holds one of Earth's major carbon reservoirs as dissolved organic matter (662 ± 32 PgC). Most of this material (>95%) is termed refractory dissolved organic carbon (RDOC) as Williams and Druffel (1987) found it to be old relative to the circulation time of the ocean. While RDOC within the modern ocean is thus perceived as vast and only slowly renewed, its mobilization has been implicated by Sexton et al. (2011) to explain Earth's transient warming events (i.e., hyperthermals) of the Paleocene and Eocene epochs (65–34 million years ago). Assessing this proposed function of RDOC as a rapidly (~5–10 kyr) exchangeable carbon reservoir is presently limited by insufficient knowledge of the responsible processes. Here we investigate the dynamics of RDOC in the deep Pacific Ocean, previously characterized by concentration gradients thought to be established by slow but systematic RDOC removal with circulation and aging of the water masses. We demonstrate that RDOC is instead conserved during much of its circulation, but that there exist localized sinks in the deep, far North Pacific and at mid depth in the subtropical South Pacific. Water mass mixing into these sink regions creates the observed RDOC gradients. Together, the Pacific sinks remove 7–29% of the 43 Tg RDOC added to the deep global ocean each year with overturning circulation, and point to an important but still unidentified control on the RDOC inventory of deep marine systems.
Global assessment of limitation to symbiotic nitrogen fixation by phosphorus availability in terrestrial ecosystems using a meta‐analysis approach
Authors: Augusto Laurent , Delerue Florian , Gallet‐Budynek Anne , Achat David L. 
Published: July 2013

AbstractSymbiotic nitrogen fixation (SNF) is the main natural source of nitrogen (N) in terrestrial ecosystems worldwide. Previous studies have shown that fixation of N by plants can be limited by the availability of phosphorus (P) in soils. We used global meta‐analysis to investigate how P availability controls SNF. In experiments in which plants were grown in an artificial medium, severe P deficiencies in the nutritive solution ([PO4] < 5–42 μM) depressed SNF flux through both a direct decrease in the plant fixation rate (i.e., decreased N fixed per unit of plant biomass) and an indirect effect (i.e., through plant biomass). In most experiments with plants grown in soils, SNF was proportional to plant biomass and was consequently only indirectly limited by P. Some cases using unfertilized and weathered soils (ultisols or oxisols), where plants were particularly P stressed, were an exception with both direct and indirect P limitations. Our global analysis of the P‐SNF relationship indicated that P bioavailability commonly limited SNF flux. We conclude that the main driver of in situ P limitation is indirect via limitation of plant growth, except in certain cases where both indirect and direct constraints may play a role. These cases of severe P deficiency may be mainly found in weathered tropical soils of Africa and South America, probably in unfertilized croplands which are depleted in P due to repeated biomass harvests.
Shifting seasonality and increasing frequency of precipitation in wet and dry seasons across the U.S.
Authors: Pal Indrani , Anderson Bruce T. , Salvucci Guido D. , Gianotti Daniel J. 
Published: July 2013

AbstractWater management, agriculture, and ecological systems are sensitive to the frequency and timing of precipitation. Here we document historical trends in these characteristics for station‐specific wet and dry seasons over the U.S. from 1930 to 2009. Simulations based on Markovian precipitation occurrence models are used as a null against which to test observed trends without resorting to area averaging. Most regions display increases in precipitation frequency during both wet and dry seasons accompanied by a decrease in length of dry spells. Prominent increases (decreases) occur over the Central and Great Plains during the dry season. An exception is the Atlantic Plains, which experienced a decrease in frequency and an increase in dry spell length, especially during the wet season. Regionally consistent trends in the timing of wet and dry seasons are also evident, particularly over the Ohio (Missouri) River valleys where the dry season now arrives up to 2–3 weeks earlier (later).
Time‐varying coupling of EEG oscillations predicts excitability fluctuations in the primary motor cortex as reflected by motor evoked potentials amplitude: An EEG‐TMS study
Authors: Ferreri Florinda , Vecchio Fabrizio , Ponzo David , Pasqualetti Patrizio , Rossini Paolo Maria 
Published: July 2013

AbstractPurposeMotor evoked potentials (MEPs) elicited by a train of consecutive, individual transcranial magnetic stimuli demonstrate fluctuations in amplitude with respect to time when recorded from a relaxed muscle. The influence of time‐varying, instantaneous modifications of the electroencephalography (EEG) properties immediately preceding the transcranial magnetic stimulation (TMS) has rarely been explored. The aim of this study was to investigate the influence of the pre‐TMS motor cortex and related areas EEG profile on time variants of the MEPs amplitude.MethodMRI‐navigated TMS and multichannel TMS‐compatible EEG devices were used. For each experimental subject, post‐hoc analysis of the MEPs amplitude that was based on the 50th percentile of the MEPs amplitude distribution provided two subgroups corresponding to “high” (large amplitude) and “low” (small amplitude). The pre‐stimulus EEG characteristics (coherence and spectral profile) from the motor cortex and related areas were analyzed separately for the “high” and “low” MEPs and were then compared.ResultsOn the stimulated hemisphere, EEG coupling was observed more often in the high compared to the low MEP trials. Moreover, a paradigmatic pattern in which TMS was able to lead to significantly larger MEPs was found when the EEG of the stimulated motor cortex was coupled in the beta 2 band with the ipsilateral prefrontal cortex and in the delta band with the bilateral centro‐parietal‐occipital cortices.ConclusionThis data provide evidence for a statistically significant influence of time‐varying and spatially patterned synchronization of EEG rhythms in determining cortical excitability, namely motor cortex excitability in response to TMS. Hum Brain Mapp 35:1969–1980, 2014. © 2013 Wiley Periodicals, Inc.
Punishing unfairness: Rewarding or the organization of a reactively aggressive response?
Authors: White Stuart F. , Brislin Sarah J. , Sinclair Stephen , Blair James R. 
Published: July 2013

ObjectivesThe neural correlates of human cooperative behavior remain poorly understood. Previous work has suggested that increases in striatal activation while punishing unfair offers represents reward signaling. However, other regions are also implicated when punishing others, for example dorsomedial frontal cortex (dmFC), anterior insula cortex (AIC), and periaqueductal gray (PAG). Moreover, the response of other regions implicated in signaling reward, for example ventromedial prefrontal cortex (vmPFC) or posterior cingulate cortex (PCC), has not been systematically examined.Experimental Design:Functional magnetic resonance imaging utilizing parametric modulation was conducted on 21 healthy adults participating in a social exchange paradigm.Principal Observations:Participants showed significant positive modulation of activity as a function of delivered punishment in caudate, dmFC, AIC, and PAG; that is, higher punishments by participants of unsatisfactory offers were associated with increasing activity within these regions. However, participants showed significantnegativemodulation of activity as a function of delivered punishment in vmPFC and PCC; increases in punishment level by participants were associated withdecreasesin activity within these regions.Conclusions:The current data question whether caudate activity when punishing unfair offers should be considered to indicate the reward value of this punishment. Instead, this activity, in conjunction with activity within dmFC, AIC, and PAG, may represent the organization of an untypical, punishing response that represents a reactive aggressive response to provocation. Notably, an inverse, regulatory relationship between vmPFC and PAG activity has been previously implicated in the context of another stimulus for reactive aggression; looming threat (Mobbs et al. [2007]: Science 317:1079–1083).Hum Brain Mapp 35:2137–2147, 2014. ©2013 Wiley Periodicals, Inc.
IMPROVING FARMERS’ ACCESS TO IRRIGATION IN THE BUFFER ZONE: AN EFFECTIVE WAY TO CONSERVE BIODIVERISTY IN THE CHITWAN NATIONAL PARK
Authors: Adhikari K.R. , Tan Y.C. , Lai J.S. , Chen Z.S. , Mishra V.S. 
Published: July 2013

ABSTRACTDrawing results from multi‐scale studies, this paper addresses the important coexistence between the Chitwan National Park and buffer‐zone farmers’ communities in the East Rapti River basin of Nepal. The relationship between the two is discussed using results of land use change (1978–2010) and water availability analysis (1976–2010). At basin level, though there are indications of losses of the government forest, the utilizable outflow of water in the river is still abundant because the process of depletion of water is very low. Scaling down to local level, irrigation systems originating in the river were evaluated and farmers interviewed across locations. There were statistical differences in irrigation system performance affecting water availability for crop production in the buffer zone. Because irrigation plays a disproportionately greater role in farm income and economic water scarcity could be removed, improvement in access to irrigation could effectively help improve food sufficiency and reduce income disparity in this basin. In the forest of the national park, encroachment seems to be low but frequencies of rhino poaching and timber pilferage have remained relatively high. As the buffer zone is the gateway to the park, and subsistence farm families live on the fringes of the park, helping irrigation development would strengthen farmers’ cooperation in enhancing resource conservation of the park. Copyright © 2013 John Wiley & Sons, Ltd.
Novel molecular correlates of endocannabinoid‐mediated fear‐conditioned analgesia in rats
Authors: Olango W.M. , Géranton S.M. , Roche M. , Hunt S.P. , Finn D.P. 
Published: July 2013

AbstractBackgroundFear‐conditioned analgesia (FCA) is the profound suppression of pain during exposure to conditioned aversive stimuli and is mediated at spinal and supraspinal levels. The endocannabinoid system plays a key role in FCA. This study investigated brain and spinal cord expression of genes implicated in pain‐ and fear‐related plasticity (Zif268 and Sgk1), following expression of formalin‐evoked nociception, contextual fear or endocannabinoid‐mediated FCA.MethodsAdult male Lister‐Hooded rats received intra‐plantar injection of formalin or saline, with or without administration of the CB1 receptor antagonist AM251 (3 mg/kg, i.p.) or vehicle, 30 min prior to re‐exposure to an arena paired 24 h previously with footshock. Real time quantitative polymerase chain reaction was used to measure expression of Zif268 and Sgk1 mRNA in the dorsal horn of the spinal cord (DHSC) and rostral ventromedial medulla (RVM) 30 min following arena re‐exposure.ResultsIntra‐plantar injection of formalin resulted in an increase in Zif268 and Sgk1 mRNA expression in the ipsilateral DHSC of non–fear‐conditioned rats, effects not observed in rats expressing FCA. Systemic administration of the CB1 receptor antagonist/inverse agonist AM251 attenuated both FCA and the FCA‐associated suppression of Zif268 expression in the ipsilateral DHSC without affecting expression of Sgk1. Conditioned fear was associated with an increase in Zif268 mRNA expression in the RVM of saline‐, but not formalin‐treated rats.ConclusionsThe present findings suggest that Zif268 in the DHSC is an important molecular correlate of endocannabinoid‐mediated FCA, and that fear‐related expression of Zif268 in the RVM is influenced by the presence of nociceptive tone.
The Asymptotic Existence of Group Divisible ‐Designs of Large Order with Index One
Authors: Mohácsy Hedvig 
Published: July 2013

AbstractThe following result gives the answer to the question of whether for a fixed number of groups u and fixed block size k a group divisible t‐design of group type with block size k and index one exists for sufficiently large m if the necessary arithmetic conditions are satisfied. Let k and u be positive integers, . Then there exists an integer such that there exists a group divisible t‐design of group type with block size k and index one for any integer satisfying the necessary arithmetic conditions

urn:x-wiley:10638539:media:jcd21365:jcd21365-math-0007The case of this theorem gives an existence theorem for transversal t‐designs of large order, which was previously proved by J. L. Blanchard in an unpublished manuscript.
Transcription Factor Sp1 Regulates T‐Type Ca2+ Channel CaV3.1 Gene Expression
Authors: González‐Ramírez Ricardo , Martínez‐Hernández Elizabeth , Sandoval Alejandro , Felix Ricardo 
Published: July 2013

AbstractVoltage‐gated T‐type Ca2+ (CaV3) channels mediate a number of physiological events in developing and mature cells, and are implicated in neurological and cardiovascular diseases. In mammals, there are three distinct T‐channel genes (CACNA1G, CACNA1H, and CACNA1I) encoding proteins (CaV3.1–CaV3.3) that differ in their localization as well as in molecular, biophysical, and pharmacological properties. The CACNA1G is a large gene that contains 38 exons and is localized in chromosome 17q22. Only basic characteristics of the CACNA1G gene promoter region have been investigated classifying it as a TATA‐less sequence containing several potential transcription factor‐binding motifs. Here, we cloned and characterized a proximal promoter region and initiated the analysis of transcription factors that control CaV3.1 channel expression using the murine Cacna1g gene as a model. We isolated a ∼1.5 kb 5′‐upstream region of Cacna1g and verified its transcriptional activity in the mouse neuroblastoma N1E‐115 cell line. In silico analysis revealed that this region possesses a TATA‐less minimal promoter that includes two potential transcription start sites and four binding sites for the transcription factor Sp1. The ability of one of these sites to interact with the transcription factor was confirmed by electrophoretic mobility shift assays. Consistent with this, Sp1 over‐expression enhanced promoter activity while siRNA‐mediated Sp1 silencing significantly decreased the level of CaV3.1 protein and reduced the amplitude of whole‐cell T‐type Ca2+ currents expressed in the N1E‐115 cells. These results provide new insights into the molecular mechanisms that control CaV3.1 channel expression. J. Cell. Physiol. 229: 551–560, 2014. © 2013 Wiley Periodicals, Inc.
Doxylamine pharmacokinetics following single dose oral administration in children ages 2–17 years
Authors: Balan Guhan , Thompson Gary A. , Gibb Roger , Li Lijuan , Hull David , Seeck Molly 
Published: July 2013

AbstractTo characterize doxylamine pharmacokinetics in children. This study was conducted in 41 subjects, ages 2–17 years. Doxylamine succinate doses based on age/weight ranged from 3.125 to 12.5 mg. A single oral dose was administered with 2 to 4 oz. of water or decaffeinated beverages ∼2 hours after a light breakfast. Plasma samples were obtained before and for 72 hours after dosing and analyzed for doxylamine using HPLC MS/MS. Pharmacokinetic parameters were estimated using non‐compartmental methods and relationships with age were assessed using linear regression. Over the fourfold dose range, Cmax was similar while AUC increased only 60%, although not statistically significant (P‐value = 0.0517). As expected due to increasing body size, CLo and Vz/F increased with age. Due to a similar increase with age for Clo and Vz/F, no age‐related differences in t1/2,z were observed (∼16 hours). Allometric scaling indicated no maturation related changes in CLo; although Vz/F remained age‐dependent, the predicted range decreased ∼70%. Overall, the single doses were well tolerated. Somnolence was the most common reported AE with no apparent differences in incidence noted with age. An age/weight dosing nomogram utilizing a fourfold range of doses achieves similar Cmax, whereas AUC increases only 60%.
Recovery of sludge humic acids with alkaline pretreatment and its impact on subsequent anaerobic digestion
Authors: Li Huan , Li Youkang , Jin Yiying , Zou Shuxin , Li Chenchen 
Published: July 2013

AbstractBACKGROUNDSludge humic and fulvic acids (HAs and FAs) can be utilized as a source of organic fertilizer. After alkaline sludge pretreatment, recovery of HAs and FAs and the impact on subsequent anaerobic digestion were studied.RESULTSTotal content of HAs and FAs in the raw sludge was 112.5 mg g‐1 total solids, and HAs constituted the major fraction. After the raw sludge was disintegrated with NaOH, an ultrafiltration membrane with a molecular weight cut‐off of 30 000 D was chosen for humic recovery from the alkaline lysate. 22.9% of HAs and FAs in the raw sludge were recovered and their total concentration was 4083 mg L‐1 in the retentate. HAs and FAs provided 30% of the organic carbon in the recovered retentate, which could be processed for humic fertilizer together with the other co‐recovered macromolecular organic substances. After alkaline pretreatment and humic recovery, the biogas yield increased by 29.4–49.2% during subsequent sludge anaerobic digestion. Due to the recovery of humic substances and the enhanced organic biodegradation, the removal rate of sludge volatile solids was improved by about 70% compared with the control.CONCLUSIONHAs, FAs and other macromolecular organic substances can be recovered from sludge by alkaline pretreatment and ultrafiltration separation, and subsequent anaerobic digestion improved significantly. © 2013 Society of Chemical Industry
Evaluation of an inclined gravity settler for microalgae harvesting
Authors: Wang Zhaowei , Hou Jing , Bowden Dustin , Belovich Joanne M. 
Published: July 2013

AbstractBACKGROUNDGiven the small size of microalgae, and the low biomass concentrations obtained in light‐limited cultures, the cost of algae harvesting is a significant barrier to commercial‐scale production of biofuel from algae. A downward‐ flow inclined gravity settler was evaluated for its effectiveness in dewatering the microalgae Scenedesmus dimorphus and Chlorella vulgaris.RESULTSExperimental results showed that S. dimorphus can be concentrated up to 8‐fold using a single settler stage, with a biomass recovery of 80%. Separation efficiency was independent of biomass concentration between 1 and 5 gdw L−1, suggesting that a two‐stage sequential system of settlers may maximize biomass recovery and concentration effectively. Efficiency of separation of C. vulgaris was slightly lower than that of S. dimorphus, most likely due to the fact that S. dimorphus exist in aggregates of four or more cells and thus may settle more easily.CONCLUSIONThe downward‐flow inclined gravity settler demonstrated consistent results with 72% efficiency in biomass recovery and low operating costs. This separation system warrants further investigation at the industrial scale, for the harvesting of algae from dilute cell suspensions, with applications to biofuels. © 2013 Society of Chemical Industry