bluuebunny/crossref_metadata_2025_split huggingface dataset:
Topographically mediated ice stream subglacial drainage networks
Authors: Hiester J. , Sergienko O. V. , Hulbe C. L. 
Published: February 2016

AbstractSatellite laser altimetry reveals short timescale changes in Antarctic ice sheet surface elevation that are suggested to be driven by subglacial water transport and storage. Here details of the interaction between the dynamics of ice stream flow, subglacial water system, and bed elevation relief are examined in the context of idealized, heterogeneous bed geometries. Using a two‐way coupled model of ice and subglacial water flow, we show that basal topography controls the temporal and spatial variability of the sub–ice stream hydraulic system. The orientation and characteristic dimensions of the topographic undulations determine the morphology (connected subglacial ponds or channel‐like subglacial water features) and timescales of the sub–ice stream drainage system. The short‐term (several years to decades) variability of the simulated coupled ice stream/subglacial water system suggests that the short‐term surface variations detected in remote sensing observations may be indicative of a rapidly evolving subglacial water system. Our simulations also show that interaction between ice flow and the highly dynamic subglacial water system has a strong effect on effective stress in the ice. Large effective stress magnitudes arise over areas where the basal traction is characterized by strong spatial gradients, that is, transitions from high to low basal traction or vise versa. These transitions migrate on multiyear timescales and thus cause large effective stress variability on the same temporal scales.
Matrix association effects on hydrodynamic sorting and degradation of terrestrial organic matter during cross‐shelf transport in the Laptev and East Siberian shelf seas
Authors: Tesi Tommaso , Semiletov Igor , Dudarev Oleg , Andersson August , Gustafsson Örjan 
Published: February 2016

AbstractThis study seeks an improved understanding of how matrix association affects the redistribution and degradation of terrigenous organic carbon (TerrOC) during cross‐shelf transport in the Siberian margin. Sediments were collected at increasing distance from two river outlets (Lena and Kolyma Rivers) and one coastal region affected by erosion. Samples were fractionated according to density, size, and settling velocity. The chemical composition in each fraction was characterized using elemental analyses and terrigenous biomarkers. In addition, a dual‐carbon‐isotope mixing model (δ13C and Δ14C) was used to quantify the relative TerrOC contributions from active layer (Topsoil) and Pleistocene Ice Complex Deposits (ICD). Results indicate that physical properties of particles exert first‐order control on the redistribution of different TerrOC pools. Because of its coarse nature, plant debris is hydraulically retained in the coastal region. With increasing distance from the coast, the OC is mainly associated with fine/ultrafine mineral particles. Furthermore, biomarkers indicate that the selective transport of fine‐grained sediment results in mobilizing high‐molecular weight (HMW) lipid‐rich, diagenetically altered TerrOC while lignin‐rich, less degraded TerrOC is retained near the coast. The loading (µg/m2) of lignin and HMW wax lipids on the fine/ultrafine fraction drastically decreases with increasing distance from the coast (98% and 90%, respectively), which indicates extensive degradation during cross‐shelf transport. Topsoil‐C degrades more readily (90 ± 3.5%) compared to the ICD‐C (60 ± 11%) during transport. Altogether, our results indicate that TerrOC is highly reactive and its accelerated remobilization from thawing permafrost followed by cross‐shelf transport will likely represent a positive feedback to climate warming.
Denitrification, leaching, and river nitrogen export in the Community Earth System Model
Authors: Nevison Cynthia , Hess Peter , Riddick Stuart , Ward Dan 
Published: February 2016

AbstractRiver nitrogen export is simulated within the Community Earth System Model (CESM) by coupling nitrogen leaching and runoff fluxes from the Community Land Model (CLM) to the River Transport Model (RTM). The coupled CLM‐RTM prognostically simulates the downstream impact of human N cycle perturbation on coastal areas. It also provides a framework for estimating denitrification fluxes of N2 and associated trace gases like N2O in soils and river sediments. An important limitation of the current model is that it only simulates dissolved inorganic nitrogen (DIN) river export, due to the lack of dissolved organic nitrogen (DON) and particulate nitrogen (PN) leaching fluxes in CLM. In addition, the partitioning of soil N loss in CLM between the primary loss pathways of denitrification and N leaching/runoff appears heavily skewed toward denitrification compared to other literature estimates, especially in nonagricultural regions, and also varies considerably among the four model configurations presented here. River N export is generally well predicted in the model configurations that include midlatitude crops, but tends to be underpredicted in rivers that are less perturbed by human agriculture. This is especially true in the tropics, where CLM likely underestimates leaching and runoff of all forms of nitrogen. River export of DIN is overpredicted in some relatively unperturbed Arctic rivers, which may result from excessive N inputs to those regions in CLM. Better representation of N loss in CLM can improve confidence in model results with respect to the core model objective of simulating nitrogen limitation of the carbon cycle.
Spacecraft surface charging within geosynchronous orbit observed by the Van Allen Probes
Authors: Sarno‐Smith Lois K. , Larsen Brian A. , Skoug Ruth M. , Liemohn Michael W. , Breneman Aaron , Wygant John R. , Thomsen Michelle F. 
Published: February 2016

AbstractUsing the Helium Oxygen Proton Electron (HOPE) and Electric Field and Waves (EFW) instruments from the Van Allen Probes, we explored the relationship between electron energy fluxes in the eV and keV ranges and spacecraft surface charging. We present statistical results on spacecraft charging within geosynchronous orbit by L and MLT. An algorithm to extract the H+ charging line in the HOPE instrument data was developed to better explore intense charging events. Also, this study explored how spacecraft potential relates to electron number density, electron pressure, electron temperature, thermal electron current, and low‐energy ion density between 1 and 210 eV. It is demonstrated that it is imperative to use both EFW potential measurements and the HOPE instrument ion charging line for examining times of extreme spacecraft charging of the Van Allen Probes. The results of this study show that elevated electron energy fluxes and high‐electron pressures are present during times of spacecraft charging but these same conditions may also occur during noncharging times. We also show noneclipse significant negative charging events on the Van Allen Probes.
Integrated time‐lapse geoelectrical imaging of wetland hydrological processes
Authors: Uhlemann S.S. , Sorensen J. P. R. , House A. R. , Wilkinson P. B. , Roberts C. , Gooddy D. C. , Binley A. M. , Chambers J. E. 
Published: February 2016

AbstractWetlands provide crucial habitats, are critical in the global carbon cycle, and act as key biogeochemical and hydrological buffers. The effectiveness of these services is mainly controlled by hydrological processes, which can be highly variable both spatially and temporally due to structural complexity and seasonality. Spatial analysis of 2‐D geoelectrical monitoring data integrated into the interpretation of conventional hydrological data has been implemented to provide a detailed understanding of hydrological processes in a riparian wetland. A two‐layered hydrological system was observed in the peat. In the lower part of the peat, upwelling of deeper groundwater from underlying deposits was considered the driver for a 30% increase in peat resistivity during Winter/Spring. In Spring/Summer there was a 60% decrease in resistivity in the near‐surface peats due to plant transpiration and/or microbial activity. Water exchange between the layers only appeared to be initiated following large drops in the encircling surface water stage. For the first time, we demonstrated that automated interpretation of geoelectrical data can be used to quantify ground movement in the vertical direction. Here, we applied this method to quantify shrink‐swell of expandable soils, affecting hydrological parameters, such as, porosity and permeability. This study shows that an integrated interpretation of hydrological and geophysical data can significantly improve the understanding of wetland hydrological processes. Potentially, this approach can provide the basis for the evaluation of ecosystem services and may aid in the optimization of wetland management strategies.
The effect of loading efficiency on the groundwater response to water level changes in shallow lakes and streams
Authors: Bakker Mark 
Published: February 2016

AbstractThe loading efficiency (sometimes called the tidal efficiency) is often neglected when simulating the head response in an aquifer to water level changes in lakes and streams. This is not appropriate when the lake or stream only partially penetrates the aquifer. In such cases, the aquifer extends below the lake or stream and is hydraulically connected through a semiconfining layer of lower permeability. The loading efficiency is the ratio between the instantaneous head response below a lake or stream and the water level change in the lake or stream. In sand and clay, whose particles are not cemented together, the instantaneous head response below a stream or lake is nearly equal to the stage change, and the loading efficiency is close to 1. New semianalytic solutions are presented for the groundwater response to water level changes in shallow lakes and streams that account for the loading efficiency of the aquifer. It is shown that the loading efficiency may have a significant effect on the head response. The effect is larger for larger values of the vertical resistance of the semiconfining layer and larger width of the stream and is much more pronounced in confined aquifers than in unconfined aquifers. The importance of the loading efficiency declines with time and with distance from the lake or stream. Graphs are presented that may be used to determine whether a certain combination of parameters gives a significant difference in the head at the lake shore or river bank when the loading efficiency is taken into account.
Tension‐saturated and unsaturated flows from line sources in subsurface irrigation: Riesenkampf's and Philip's solutions revisited
Authors: Kacimov A. R. , Obnosov Yu. V. 
Published: February 2016

AbstractRiesenkampf's (1938), R‐38 (referred to here as R‐38), analytical solution for steady 2‐D flow from a buried line source in a homogeneous Green‐Ampt soil, with a wetting plume bounded by a free surface (capillary fringe), is compared with Philip's (1969), (P‐69), one for genuinely unsaturated wetting of Gardner's infinite‐extension soil. Conformal mappings are used in R‐38, from which we derived the flow net, pore‐water isobars, isochrones, fields of Darcian velocity and resultant force acting on saturated porous skeleton, fine geometry (shape and size) of the constant‐head contour encompassing a mole‐emitter or leaky‐pipe, as well as the dependence of the total discharge per unit pipe length on uniform pressure in the pipe, capillarity of the soil, radius of the pipe, and saturated hydraulic conductivity. An ovalic “water table” isobar, encompassing P‐69 source, is compared with one of R‐38 for a fixed discharge and saturated conductivity but adjusted sorptive numbers. The Whisler and Bouwer (1970) relation between the static height of capillary rise and sorptive number is shown to give a good match between R‐38 and P‐69 isobars. This allows to use R‐38 in the source vicinity and P‐69 in the far‐field zone. Computer algebra (Mathematica) routines are used for visualization of the known and extended R‐38 and P‐69 solutions.
Hydrogeomorphic controls on hyporheic and riparian transport in two headwater mountain streams during base flow recession
Authors: Ward Adam S. , Schmadel Noah M. , Wondzell Steven M. , Harman Ciaran , Gooseff Michael N. , Singha Kamini 
Published: February 2016

AbstractSolute transport along riparian and hyporheic flow paths is broadly expected to respond to dynamic hydrologic forcing by streams, aquifers, and hillslopes. However, direct observation of these dynamic responses is lacking, as is the relative control of geologic setting as a control on responses to dynamic hydrologic forcing. We conducted a series of four stream solute tracer injections through base flow recession in each of two watersheds with contrasting valley morphology in the H.J. Andrews Experimental Forest, monitoring tracer concentrations in the stream and in a network of shallow riparian wells in each watershed. We found hyporheic mean arrival time, temporal variance, and fraction of stream water in the bedrock‐constrained valley bottom and near large roughness elements in the wider valley bottom were not variable with discharge, suggesting minimal control by hydrologic forcing. Conversely, we observed increases in mean arrival time and temporal variance and decreasing fraction stream water with decreasing discharge near the hillslopes in the wider valley bottom. This may indicate changes in stream discharge and valley bottom hydrology control transport in less constrained locations. We detail five hydrogeomorphic responses to base flow recession to explain observed spatial and temporal patterns in the interactions between streams and their valley bottoms. Models able to account for the transition from geologically dominated processes in the near‐stream subsurface to hydrologically dominated processes near the hillslope will be required to predict solute transport and fate in valley bottoms of headwater mountain streams.
El Niño and the U.S. precipitation and floods: What was expected for the January–March 2016 winter hydroclimate that is now unfolding?
Authors: Steinschneider Scott , Lall Upmanu 
Published: February 2016

AbstractSea surface temperatures in the equatorial Pacific exhibited persistent warming beginning in January 2015 and by November 2015 were predicted to deliver a strong El Niño in the coming winter, perhaps the strongest on record, with wide‐reaching hydroclimate impacts. As ENSO continues to evolve over the 2016 winter season, we ask the question: To what degree could ENSO‐related hydroclimate impacts have been anticipated a season prior? We provide a retrospective hydroclimate outlook for the 2016 winter, accounting for the prevailing uncertainties that often pose a challenge to local resource managers seeking to make use of seasonal forecasts.
Emotional Security Theory and Developmental Psychopathology
Authors: Davies Patrick T. , Martin Meredith J. , Sturge‐Apple Melissa L. 
Published: February 2016

AbstractEmotional security theory was introduced over two decades ago to explain how and why children exposed to interparental and family conflict are at greater risk for developing psychopathology. Using developmental psychopathology as an evaluative lens, this chapter provides a review of the progress, challenges, and future directions in testing EST. After characterizing the distinctive properties of the goal system of emotional security in relation to developmental constructs outlined in other approaches, we review empirical evidence supporting the hypothesis that emotional insecurity is a unique and robust mediator of multiple pathways involving family adversity and children's adjustment problems. Next, the chapter addresses the family, contextual, developmental sources underlying the multiplicity of pathways among family discord, emotional insecurity, and children's psychological functioning. Throughout the chapter, we distinguish between two formulations of EST to adequately characterize the significant developments in the history of the theory. Finally, we conclude by outlining scientific and clinical growing points for EST.
Interpersonal Theories of Developmental Psychopathology
Authors: Rudolph Karen D. , Lansford Jennifer E. , Rodkin Philip C. 
Published: February 2016

AbstractInterpersonal theories enjoy a long and multidisciplinary history in the field of developmental psychopathology. A core theme is that disruption in developmentally salient interpersonal processes interferes with youths' inherent need for relatedness, creating risk for multiple types of disorders. We review major theories of interpersonal risk—focusing on the family, the peer group, and broader stressful interpersonal contexts—and describe how each theory accounts for the emergence of particular disorders. We then discuss the intersection between interpersonal theories and other theories of psychopathology, postulating how multiple interacting and transacting levels and systems of development (e.g., biological, cognitive, emotional, contextual) jointly contribute to risk for psychopathology. Synthesizing across these broad approaches, we discuss specific integrative interpersonal theories of depression, anxiety, and externalizing disorders. We close with a discussion of ways to enrich interpersonal theories and bridge the divide between theory and practice to protect youth against psychopathology and maximize youth potential across development.
Synthesis and Characterization of Biodegradable Hydrogels for Oral Delivery of 5‐Fluorouracil Targeted to Colon: Screening with Preliminary In Vivo Studies
Authors: Minhas Muhammad Usman , Ahmad Mahmood , Anwar Jamshed , Khan Shahzeb 
Published: February 2016

ABSTRACTIn this communication, we developed a thermally stable, biocompatible, and colonically degradable hydrogel‐based device [pectin‐co‐poly(MAA)] for oral delivery of 5‐fluorouracil (5‐FU) to treat colon cancer with minimal upper gastrointestinal invasion. Toward this end, ethylene glycol dimethacrylate (EGDMA) cross‐linked hydrogels of pectin were synthesized. Methacrylic acid (MAA) was grafted to impart pH‐responsive character, whereas benzoyl peroxide (BPO) was applied for simultaneous grafting and cross‐linking polymerization. The hydrogels were characterized by Fourier transform infrared , thermogravimetric analysis, differential scanning calorimetry, and X‐ray diffractometry. Scanning electron microscopic photographs were taken to analyze the surface morphology. Swelling behavior was analyzed to assess better performance of biodegradable hydrogels for optimized loading and release of the drug targeted to the colon. Gel fraction, swelling ratio, diffusion coefficient, drug loading, and cumulative release increased with an increase of pectin ratio and decreased with an increase of MAA and EGDMA ratio. Strategically, hydrogels with higher amounts of pectin were prepared for complete degradation in the colon. Our investigations indicate that pectin‐co‐poly(MAA) hydrogel is a suitable delivery system developed for oral delivery of the drug targeted to the colon.
Fabrication of Thickness‐Controllable Micropatterned Polyelectrolyte‐Film/Nanoparticle Surfaces by Using the Plasma Oxidation Method
Authors: Zhu Chun‐Tao , Ma Sheng‐Hua , Zhang Ying , Wang Xue‐Jing , Lv Peng , Han Xiao‐Jun 
Published: February 2016

AbstractWe have demonstrated a novel way to form thickness‐controllable polyelectrolyte‐film/nanoparticle patterns by using a plasma etching technique to form, first, a patterned self‐assembled monolayer surface, followed by layer‐by‐layer assembly of polyelectrolyte‐films/nanoparticles. Octadecyltrimethoxysilane (ODS) and (3‐aminopropyl)triethoxysilane (APTES) self‐assembled monolayers (SAMs) were used for polyelectrolyte‐film and nanoparticle patterning, respectively. The resolution of the proposed patterning method can easily reach approximately 2.5 μm. The height of the groove structure was tunable from approximately 2.5 to 150 nm. The suspended lipid membrane across the grooves was fabricated by incubating the patterned polyelectrolyte groove arrays in solutions of 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) giant unilamellar vesicles (GUVs). The method demonstrated here reveals a new path to create patterned 2D or 3D structures.
Ist Evolution vorhersagbar?
Authors: Pfenninger Markus , Plath Martin 
Published: February 2016

AbstractUnsere Arbeit nutzt die mehrfach unabhängig erfolgte Anpassung an giftigen Schwefelwasserstoff (H2S) durch den Süßwasserfisch Poecilia mexicana in verschiedenen Quellbereichen mehrerer Flüsse in Mexiko, um die Frage nach der Vorhersagbarkeit von Evolution zu beantworten. Wir sequenzierten Populationsgenome von an H2S adaptierten Fischen sowie von Fischen aus der nächstgelegenen Klarwasserpopulation in zwei Flusssystemen, um das Ausmaß gleichgerichteter Evolution zwischen den beiden Flusssystemen quantitativ vergleichen zu können. In Übereinstimmung mit der Kontingenzhypothese lag der Anteil der nicht‐zufälligen Übereinstimmungen auf den meisten hierarchischen Ebenen biologischer Organisation bei weniger als einem Prozent. Selbst bei der H2S‐Toleranz als Schlüsselanpassung konnten wir verschiedene Mechanismen identifizieren. Diese weitgehend unabhängigen evolutionären Wege der Anpassung gehen auf neu entstandene, unterschiedliche Mutationen zurück.
Saccharomyces cerevisiae – eine Hefe macht Karriere
Authors: Stolzenberg Tobias 
Published: February 2016

AbstractDie Bier‐ und Bäckerhefe kann mehr als Brot backen, Bier brauen und Krankheiten kurieren. Inzwischen macht der Mikroorganismus Karriere in Biotechnologie und Synthetischer Biologie. Und auch andere Branchen sind sehr an einer Zusammenarbeit mit Saccharomyces cerevisiae interessiert.
Williams–Beuren syndrome: pitfalls for diagnosis in limited resources setting
Authors: Lumaka Aimé , Lukoo Rita , Mubungu Gerrye , Lumbala Paul , Mbayabo Gloire , Mupuala Aimée , Tshilobo Prosper Lukusa , Devriendt Koenraad 
Published: February 2016

Key Clinical MessagePatients with Williams–Beuren Syndrome can be recognized clinically, given the characteristic dysmorphism, intellectual disability, and behavior. We report on a Congolese boy with typical WBS facial characteristics. He suffered meningitis and coma at the age of 2 years then subsequently presented with profound intellectual disability and atypical behavior. The WBS was only made at age 8.2 years and confirmed with FISH testing and microarray‐CGH. The present report aims to warn clinicians that infections may associate and/or modify a genetic disease as this may be observed in developing countries given the prevalence of infectious diseases.
Local recurrence of pheochromocytoma in multiple endocrine neoplasia type 2A: a diagnostic and therapeutic challenge
Authors: Tramunt Blandine , Buffet Alexandre , Grunenwald Solange , Vezzosi Delphine , Bennet Antoine , Huyghe Eric , Zerdoud Slimane , Caron Philippe 
Published: February 2016

Key Clinical MessageIn a patient with multiple endocrine neoplasia type 2A (MEN2A), an inverted physiological ratio between urinary normetanephrines and metanephrines is an early marker of recurrence in epinephrine‐secreting pheochromocytoma, and 131I MIBG treatment appears to be a useful therapeutic option in order to avoid multiple invasive surgical procedures in pheochromocytomatosis.
A Perylene‐Based Microporous Coordination Polymer Interacts Selectively with Electron‐Poor Aromatics
Authors: Tran Ly D. , Ma Jialiu , Wong‐Foy Antek G. , Matzger Adam J. 
Published: February 2016

AbstractThe design, synthesis, and properties of the new microporous coordination polymer UMCM‐310 are described. The unique electronic character of the perylene‐based linker enables selective interaction with electron‐poor aromatics leading to efficient separation of nitroaromatics. UMCM‐310 possesses high surface area and large pore size and thus permits the separation of large organic molecules based on adsorption rather than size exclusion.