bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil thermal dynamics, snow cover, and frozen depth under five temperature treatments in an ombrotrophic bog: Constrained forecast with data assimilation
Authors: Huang Yuanyuan , Jiang Jiang , Ma Shuang , Ricciuto Daniel , Hanson Paul J. , Luo Yiqi 
Published: August 2017

AbstractAccurate simulation of soil thermal dynamics is essential for realistic prediction of soil biogeochemical responses to climate change. To facilitate ecological forecasting at the Spruce and Peatland Responses Under Climatic and Environmental change site, we incorporated a soil temperature module into a Terrestrial ECOsystem (TECO) model by accounting for surface energy budget, snow dynamics, and heat transfer among soil layers and during freeze‐thaw events. We conditioned TECO with detailed soil temperature and snow depth observations through data assimilation before the model was used for forecasting. The constrained model reproduced variations in observed temperature from different soil layers, the magnitude of snow depth, the timing of snowfall and snowmelt, and the range of frozen depth. The conditioned TECO forecasted probabilistic distributions of soil temperature dynamics in six soil layers, snow, and frozen depths under temperature treatments of +0.0, +2.25, +4.5, +6.75, and +9.0°C. Air warming caused stronger elevation in soil temperature during summer than winter due to winter snow and ice. And soil temperature increased more in shallow soil layers in summer in response to air warming. Whole ecosystem warming (peat + air warmings) generally reduced snow and frozen depths. The accuracy of forecasted snow and frozen depths relied on the precision of weather forcing. Uncertainty is smaller for forecasting soil temperature but large for snow and frozen depths. Timely and effective soil thermal forecast, constrained through data assimilation that combines process‐based understanding and detailed observations, provides boundary conditions for better predictions of future biogeochemical cycles.
Complex terrain influences ecosystem carbon responses to temperature and precipitation
Authors: Reyes W. M. , Epstein H. E. , Li X. , McGlynn B. L. , Riveros‐Iregui D. A. , Emanuel R. E. 
Published: August 2017

AbstractTerrestrial ecosystem responses to temperature and precipitation have major implications for the global carbon cycle. Case studies demonstrate that complex terrain, which accounts for more than 50% of Earth's land surface, can affect ecological processes associated with land‐atmosphere carbon fluxes. However, no studies have addressed the role of complex terrain in mediating ecophysiological responses of land‐atmosphere carbon fluxes to climate variables. We synthesized data from AmeriFlux towers and found that for sites in complex terrain, responses of ecosystem CO2 fluxes to temperature and precipitation are organized according to terrain slope and drainage area, variables associated with water and energy availability. Specifically, we found that for tower sites in complex terrain, mean topographic slope and drainage area surrounding the tower explained between 51% and 78% of site‐to‐site variation in the response of CO2 fluxes to temperature and precipitation depending on the time scale. We found no such organization among sites in flat terrain, even though their flux responses exhibited similar ranges. These results challenge prevailing conceptual framework in terrestrial ecosystem modeling that assumes that CO2 fluxes derive from vertical soil‐plant‐climate interactions. We conclude that the terrain in which ecosystems are situated can also have important influences on CO2 responses to temperature and precipitation. This work has implications for about 14% of the total land area of the conterminous U.S. This area is considered topographically complex and contributes to approximately 15% of gross ecosystem carbon production in the conterminous U.S.
Storm time empirical model of O+ and O6+ distributions in the magnetosphere
Authors: Allen R. C. , Livi S. A. , Vines S. K. , Goldstein J. , Cohen I. , Fuselier S. A. , Mauk B. H. , Spence H. E. 
Published: August 2017

AbstractRecent studies have utilized different charge states of oxygen ions as a tracer for the origins of plasma populations in the magnetosphere of Earth, using O+ as an indicator of ionospheric‐originating plasma and O6+ as an indicator of solar wind‐originating plasma. These studies have correlated enhancements in O6+ to various solar wind and geomagnetic conditions to characterize the dominant solar wind injection mechanisms into the magnetosphere but did not include analysis of the temporal evolution of these ions. A sixth‐order Fourier expansion model based empirically on a superposed epoch analysis of geomagnetic storms observed by Polar is presented in this study to provide insight into the evolution of both ionospheric‐originating and solar wind‐originating plasma throughout geomagnetic storms. At high energies (~200 keV) the flux of O+ and O6+ are seen to become comparable in the outer magnetosphere. Moreover, while the density of O+ is far higher than O6+, the two charge states have comparable pressures in the outer magnetosphere. The temperature of O6+ is generally higher than that of O+, because the O6+ is injected from preheated magnetosheath populations before undergoing further heating once in the magnetosphere. A comparison between the model results with O+ observations from the Magnetospheric Multiscale mission and the Van Allen Probes provides a validation of the model. In general, this empirical model agrees qualitatively well with the trends seen in both data sets. Quantitatively, the modeled density, pressure, and temperature almost always agree within a factor of at most 10, 5, and 2, respectively.
Velocity models and hypocenter relocations for the Charlevoix Seismic Zone
Authors: Powell Christine A. , Lamontagne Maurice 
Published: August 2017

AbstractThree‐dimensional P and S wave velocity (Vp and Vs) models and hypocenter relocations are determined for the Charlevoix Seismic Zone (CSZ) using local arrival time tomography. The CSZ is located along the St. Lawrence River about 100 km downstream from Quebec City, Canada, and is one of the most active seismic zones in eastern North America. Earthquakes occur in Grenvillian basement rocks affected by Iapetan Ocean rifting and a large Devonian meteor impact. Low Vp and Vs are associated with the impact structure to a depth of 12 km. Relocated hypocenters form a semicircle delineating the eastern margin of the impact structure. Northeast of the impact, hypocenters cluster into two groups separated by a region of high Vp and Vs velocity. Hypocenters within each group align along planar surfaces, suggesting the presence of distinct seismogenic faults. The planes trend NE, in the same direction as the Iapetan rift faults, and dip to the SE. One plane is located beneath the north shore of the St. Lawrence River and extends to a depth of at least 30 km. Two other planes with shallower dips are located beneath the river and extend to depths of 12 and 15 km. All three planes are disrupted within the impact zone but can be followed, suggesting partial preservation of rift‐parallel fault fabric.
Assessment of NOAA NUCAPS upper air temperature profiles using COSMIC GPS radio occultation and ARM radiosondes
Authors: Feltz M. L. , Borg L. , Knuteson R. O. , Tobin D. , Revercomb H. , Gambacorta A. 
Published: August 2017

AbstractThe U.S. National Oceanic and Atmospheric Administration (NOAA) recently began operational processing to derive vertical temperature profiles from two new sensors, Cross‐Track Infrared Sounder and Advanced Technology Microwave Sounder, which were developed for the next generation of U.S. weather satellites. The NOAA‐Unique Combined Atmospheric Processing System (NUCAPS) has been developed by NOAA to routinely process data from future Joint Polar Satellite System operational satellites and the preparatory Suomi‐NPP satellite. This paper assesses the NUCAPS vertical temperature profile product from the upper troposphere into the middle stratosphere using radiosonde and GPS radio occultation (RO) data. Radiosonde data from the Department of Energy Atmospheric Radiation Measurement (ARM) program are=] compared to both the NUCAPS and GPS RO temperature products to evaluate bias and RMS errors. At all three fixed ARM sites for time periods investigated the NUCAPS temperature in the 100–40 hPa range is found to have an average bias to the radiosondes of less than 0.45 K and an RMS error of less than 1 K when temperature averaging kernels are applied. At a 95% confidence level, the radiosondes and RO were found to agree within 0.4 K at the North Slope of Alaska site and within 0.83 K at Southern Great Plains and Tropical Western Pacific. The GPS RO‐derived dry temperatures, obtained from the University Corporation for Atmospheric Research Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission, are used as a common reference for the intercomparison of NUCAPS temperature products to similar products produced by NASA from Atmospheric Infrared Sounder (AIRS) and by European Organisation for the Exploitation of Meteorological Satellites from MetOp‐B Infrared Atmospheric Sounding Interferometer (IASI). For seasonal and zonal scales, the NUCAPS agreement with AIRS and IASI is less than 0.5 K after application of averaging kernels.
Granular avalanches on the Moon: Mass‐wasting conditions, processes, and features
Authors: Kokelaar B. P. , Bahia R. S. , Joy K. H. , Viroulet S. , Gray J. M. N. T. 
Published: August 2017

AbstractSeven lunar crater sites of granular avalanches are studied utilizing high‐resolution images (0.42–1.3 m/pixel) from the Lunar Reconnaissance Orbiter Camera; one, in Kepler crater, is examined in detail. All the sites are slopes of debris extensively aggraded by frictional freezing at their dynamic angle of repose, four in craters formed in basaltic mare and three in the anorthositic highlands. Diverse styles of mass wasting occur, and three types of dry‐debris flow deposit are recognized: (1) multiple channel‐and‐lobe type, with coarse‐grained levees and lobate terminations that impound finer debris, (2) single‐surge polylobate type, with subparallel arrays of lobes and fingers with segregated coarse‐grained margins, and (3) multiple‐ribbon type, with tracks reflecting reworked substrate, minor levees, and no coarse terminations. The latter type results from propagation of granular erosion‐deposition waves down slopes dominantly of fine regolith, and it is the first recognized natural example. Dimensions, architectures, and granular segregation styles of the two coarse‐grained deposit types are like those formed in natural and experimental avalanches on Earth, although the timescale of motion differs due to the reduced gravity. Influences of reduced gravity and fine‐grained regolith on dynamics of granular flow and deposition appear slight, but we distinguish, for the first time, extensive remobilization of coarse talus by inundation with finer debris. The (few) sites show no clear difference attributable to the contrasting mare basalt and highland megaregolith host rocks and their fragmentation. This lunar study offers a benchmarking of deposit types that can be attributed to formation without influence of liquid or gas.
Visualization and quantification of capillary drainage in the pore space of laminated sandstone by a porous plate method using differential imaging X‐ray microtomography
Authors: Lin Qingyang , Bijeljic Branko , Rieke Holger , Blunt Martin J. 
Published: August 2017

AbstractThe experimental determination of capillary pressure drainage curves at the pore scale is of vital importance for the mapping of reservoir fluid distribution. To fully characterize capillary drainage in a complex pore space, we design a differential imaging‐based porous plate (DIPP) method using X‐ray microtomography. For an exemplar mm‐scale laminated sandstone microcore with a porous plate, we quantify the displacement from resolvable macropores and subresolution micropores. Nitrogen (N2) was injected as the nonwetting phase at a constant pressure while the porous plate prevented its escape. The measured porosity and capillary pressure at the imaged saturations agree well with helium measurements and experiments on larger core samples, while providing a pore‐scale explanation of the fluid distribution. We observed that the majority of the brine was displaced by N2 in macropores at low capillary pressures, followed by a further brine displacement in micropores when capillary pressure increases. Furthermore, we were able to discern that brine predominantly remained within the subresolution micropores, such as regions of fine lamination. The capillary pressure curve for pressures ranging from 0 to 1151 kPa is provided from the image analysis compares well with the conventional porous plate method for a cm‐scale core but was conducted over a period of 10 days rather than up to few months with the conventional porous plate method. Overall, we demonstrate the capability of our method to provide quantitative information on two‐phase saturation in heterogeneous core samples for a wide range of capillary pressures even at scales smaller than the micro‐CT resolution.
Nutrigenomics
Authors: Gasperi Valeria , Vangapandu Chaitanya , Catani Maria Valeria , Savini Isabella 
Published: August 2017

AbstractIn recent years, nutrition research has moved from epidemiology and physiology to molecular genetics. In this context, omics studies are emerging as an appealing tool for nutritional scientists. It is known that nutrients can interact with genes affecting transcription factors, protein expression and metabolite production. Nutritional genomics (nutrigenomics) is seen as a bridge between health diet and genotype. Dietary components affect gene expression patterns (transcriptome), chromatin organisation (epigenome) and protein expression patterns, including posttranslational modifications (proteome) and metabolite profiles (metabolome).Key ConceptsDietary habits are one of the crucial exogenous factors impacting health and incidence of several chronic diseases, including obesity, type 2 diabetes, cardiovascular diseases, metabolic syndrome and cancer.Several lines of evidence indicate that nutrients can interact with genes, affecting gene transcription, protein expression and metabolite production.Nutrigenomic studies describe the effect of food on gene expression, thus providing insight into how diet and genotype interactions affect physical and mental health.Macronutrients may directly act as ligands for transcription factors or alter signal transduction pathways responsible for modifications in gene expression.Glucose, in the presence of insulin, induces the expression of genes encoding for glycolytic and lipogenic enzymes, thereby regulating glucose homeostasis.Dietary fats deeply change gene expression, triggering an adaptive response to fluctuations in the quantity and quality of fat ingested.Both quantity and quality of ingested proteins influence the expression of several genes.In addition, micronutrients (vitamins and minerals) and phytochemicals exert a health‐promoting action by modulating distinct signal transduction pathways via direct interaction with transcription factors or via epigenetic modifications of target promoters.Gene–diet interaction is a complex network, where food components usually act in concert; therefore, it is not easy to translate scientific evidence into nutritional advice.
Retinoic Acid and Immunity
Authors: Larange Alexandre 
Published: August 2017

Abstract

Vitamin A and its active metabolite retinoic acid (RA) are key players in the regulation of the immune response, especially at the mucosal borders, where RA is particularly abundant. Retinoic acid receptors (RARs), via their transcriptional activity, modulate the expression of many genes in many types of immune cells, such as T cells, B cells, macrophages or dendritic cells. Among the pleiotropic effects on immune cells, the ability of RA and RARs to confer gut tropism and to promote the generation of regulatory T cells (Tregs) are undoubtedly the most prominent. However, depending on the physiopathological context, RA can also promote inflammation. These multiple and sometimes paradoxical properties of RA reflect the importance of this nutrient‐derived molecule in the fine‐tuning of the immune system.

Key Concepts

Retinoic acid is the active metabolite of Vitamin A, a nutrient essential for many biological processes.

Retinoic acid receptors act as transcription factors to regulate the expression of several genes.

Retinoic acid induces the expression of gut homing receptors on several immune cells.

Retinoic acid induces the generation of regulatory T cells that control the immune and inflammatory response.

In certain physiopathological contexts, retinoic acid can act as an adjuvant to promote inflammation.
Conjugated Polymer Nanoparticles toward In Vivo Theranostics – Focus on Targeting, Imaging, Therapy, and the Importance of Clearance
Authors: Kuehne Alexander J. C. 
Published: August 2017

AbstractConjugated polymer nanoparticles are highly fluorescent colloids with tunable emission colors ranging from the visible deep into the near infrared spectrum. Conjugated polymer nanoparticles are easy to prepare, tunable in their size, and virtually nonbleachable. Conjugated polymer particles can also be designed to give off heat upon irradiation. All these properties make conjugated polymer particles ideal materials for biomedical fluorescence and photoacoustic imaging as well as for theranostic applications. Here, different examples of surface functionalization to attach pathological homing devices, imaging modalities, as well as the emerging possibilities for therapeutic measures are discussed. Furthermore, clearance of the particles is considered, which is important to ultimately apply the materials for in vivo theranostics. Due to the conjugated backbone of the conjugated polymers, established degradation strategies, as known from hydrophilic nonconjugated polymer carriers, cannot be applied. Bioinspired strategies and potential pathways for degradation and clearance via structural changes upon triggers such as pH, oxidation, and temperature are also discussed in this progress report.
Integrin‐Mediated Interactions Control Macrophage Polarization in 3D Hydrogels
Authors: Cha Byung‐Hyun , Shin Su Ryon , Leijten Jeroen , Li Yi‐Chen , Singh Sonali , Liu Julie C. , Annabi Nasim , Abdi Reza , Dokmeci Mehmet R. , Vrana Nihal Engin , Ghaemmaghami Amir M. , Khademhosseini Ali 
Published: August 2017

AbstractAdverse immune reactions prevent clinical translation of numerous implantable devices and materials. Although inflammation is an essential part of tissue regeneration, chronic inflammation ultimately leads to implant failure. In particular, macrophage polarity steers the microenvironment toward inflammation or wound healing via the induction of M1 and M2 macrophages, respectively. Here, this paper demonstrates that macrophage polarity within biomaterials can be controlled through integrin‐mediated interactions between human monocytic THP‐1 cells and collagen‐derived matrix. Surface marker, gene expression, biochemical, and cytokine profiling consistently indicate that THP‐1 cells within a biomaterial lacking cell attachment motifs yield proinflammatory M1 macrophages, whereas biomaterials with attachment sites in the presence of interleukin‐4 (IL‐4) induce an anti‐inflammatory M2‐like phenotype and propagate the effect of IL‐4 in induction of M2‐like macrophages. Importantly, integrin α2β1 plays a pivotal role as its inhibition blocks the induction of M2 macrophages. The influence of the microenvironment of the biomaterial over macrophage polarity is further confirmed by its ability to modulate the effect of IL‐4 and lipopolysaccharide, which are potent inducers of M2 or M1 phenotypes, respectively. Thus, this study represents a novel, versatile, and effective strategy to steer macrophage polarity through integrin‐mediated 3D microenvironment for biomaterial‐based programming.
Surfaces Inspired by the Nepenthes Peristome for Unidirectional Liquid Transport
Authors: Zhang Pengfei , Zhang Liwen , Chen Huawei , Dong Zhichao , Zhang Deyuan 
Published: August 2017

AbstractThe slippery peristome of the pitcher plant Nepenthes has attracted much attention due to its unique function for preying on insects. Recent findings on the peristome surface of Nepenthes alata demonstrate a fast and continuous unidirectional liquid transport, which is enabled by the combination of a pinning effect at the sharp edges and a capillary rise in the wedge, deriving from the multiscale structure, which provides inspiration for designing and fabricating functional surfaces for unidirectional liquid transport. Developments in the fabrication methods of peristome‐inspired surfaces and control methods for liquid transport are summarized. Both potential applications in the fields of microfluidic devices, biomedicine, and mechanical engineering and directions for further research in the future are discussed.
Mixed Ionic–Electronic Conduction in Binary Polymer Nanoparticle Assemblies
Authors: Renna Lawrence A. , Lenef Julia D. , Bag Monojit , Venkataraman D. 
Published: August 2017

AbstractPolymer‐based mixed ionic–electronic conductors (MIECs) are desired for both bulk and interfacial materials in next‐generation energy storage and electronic devices. Polymer‐based MIECs contain two principal components, one for electronic conduction and the other for ionic conduction. The central problem is the lack of a general approach to control the molecular packing and morphology of the constituent components that will afford the ability to easily tune transport properties. This study demonstrates the efficacy of a modular method based on polymer nanoparticle self‐assembly to achieve MIECs with tunable conductivity. This work uses poly(3‐hexylthiophene) nanoparticles as the electronic conductor and lithium ion‐doped poly(vinylpyridine) nanoparticles as the ionic conductors. AC impedance spectroscopic studies show that nanoparticle–nanoparticle interfaces in unary assemblies do not impede ion transport in the solid state. AC impedance spectroscopy and DC steady‐state conductivity measurements show that binary nanoparticle assemblies exhibit concurrent ionic and electronic conduction. The power‐law scaling percolation of both the ionic and electronic transport displays nonuniversal values of transport critical exponent, revealing different transport mechanisms. The simplicity of fabrication combined with the versatility in obtainable transport properties illustrates the power of using nanoparticle assemblies as a means to realize MIEC polymer mesoscale morphologies.