bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear Long‐Term Large Watershed Hydrologic Response to Wildfire and Climatic Dynamics Locally Increases Water Yields
Authors: Wine Michael L. , Makhnin Oleg , Cadol Daniel 
Published: June 2018

AbstractOn all inhabited continents, wildfires are important ecological disturbances that influence water resources. As an exemplar of this global phenomenon, wildfire activity in the western United states increased in the 1980s and has continued to trend upward in subsequent decades. However, the hydrologic impact of wildfire has been difficult to ascertain at a continental scale due to the complexity of processes that influence critical zone dynamics. We calibrated Fuh's equation to wildfire‐impacted gauged watersheds and used the validated model to retrospectively quantify the proportion of streamflow attributed to wildfire hydrologic impacts from 1986 to 2015 across ungauged watersheds, accounting for interwatershed variability in water retention capacity and climate as well as how these factors interact with burned area and postwildfire vegetation recovery. Here we show that in parts of the western United States with high proportion of area burned by fire, wildfire‐linked streamflow accounts for as much as 20% of streamflow, rivaling or exceeding predicted climate change impacts. This analytic framework demonstrates that over a multidecadal period, the present trajectory of rising temperatures and increases in large wildfires may enhance the regional‐scale importance of wildfires in streamflow generation, thereby partially offsetting projected streamflow reductions due to rising temperatures and evaporative demand.
Infrasound Tornillos Produced by Volcán Cotopaxi's Deep Crater
Authors: Johnson J. B. , Ruiz M. C. , Ortiz H. D. , Watson L. M. , Viracucha G. , Ramon P. , Almeida M. 
Published: June 2018

AbstractWe characterize and interpret a new type of infrasound signal originating from the summit of Volcán Cotopaxi (Ecuador) that was primarily observed between September 2015 and March 2016, following the 2015 eruptive period. This infrasound waveform is a slowly decaying sinusoid with exceptional low‐frequency (fp = 0.2 Hz) and high quality factor (Q = ~10) and resembles the shape of tornillo seismic waveforms. The repeating events, occurring about once per day in early 2016, are stable in frequency content, and we attribute them to excitation of a vertical‐walled crater, with radius of about 125 m and length of 300 m. Spectral properties of the tornillo permit constraints on crater sound speed (335 m/s ± 6%) and temperature (4–32°C). The initial polarity of the tornillos is predominantly a rarefaction and could reflect repeating crater bottom collapse events (implosions) or explosion sources whose infrasound is heavily modulated by the crater's pipe‐like geometry.
Enhanced Ammonia Oxidation Caused by Lateral Kuroshio Intrusion in the Boundary Zone of the Northern South China Sea
Authors: Xu Min Nina , Zhang Weijie , Zhu Yifan , Liu Li , Zheng Zhenzhen , Wan Xianhui Sean , Qian Wei , Dai Minhan , Gan Jianping , Hutchins David A. , Kao Shuh‐Ji 
Published: June 2018

AbstractLateral input of dissolved organics may play a significant role to support productivity in oligotrophic ocean although associated biogeochemical evidences are lacking in the field. Ammonia oxidation (AO), the first step of nitrification that bridges organic remineralization and nitrate, is potentially an immediate responder. By using 15N‐NH4+, the spatial distribution of AO was investigated in the northern South China Sea, where Kuroshio Current intrudes frequently. AO ranged widely (0.001 to 134 nmol · L−1 · day−1) in space and the depth‐integrated (200 m) AO peaked where the Kuroshio influence is moderate suggesting that enhanced AO had occurred due to lateral mixing. Since oligotrophic Kuroshio is characterized by high dissolved organic nitrogen (DON), such lateral mixing not only introduces external DON into the northern South China Sea but also enhances NH4+ regeneration and subsequent oxidation to complicate the conventional new production in the boundary zone with DON gradient.
Effects of the September 2005 Solar Flares and Solar Proton Events on the Middle Atmosphere in WACCM
Authors: Pettit J. , Randall C. E. , Marsh D. R. , Bardeen C. G. , Qian L. , Jackman C. H. , Woods T. N. , Coster A. , Harvey V. L. 
Published: June 2018

AbstractThis work investigates middle atmosphere effects of the September 2005 solar flares and solar proton events (SPEs). X‐17 and X‐6.2 flares occurred on 7 and 9 September, respectively, while two moderate SPEs occurred on 10 and 15 September. Flare ionization and dissociation were calculated in the Whole Atmosphere Community Climate Model (WACCM) using the Flare Irradiance Spectral Model. Proton measurements from the Geostationary Operational Environmental Satellite system were used to compute solar proton ionization. SPEs are shown to have a larger impact than solar flares on the polar stratosphere and mesosphere; however, flares have a larger influence on the sunlit and equatorial lower thermosphere. The two flares differed significantly with respect to photon spectrum. The larger, X‐17 flare was stronger during the impulsive phase, while the X‐6.2 flare was stronger during the gradual phase. This resulted in the X‐17 flare causing more initial ionization but for a shorter duration. The simulated flare impacts also differed because specific wavelengths of the flares influenced the atmosphere above the model top. Model‐measurement comparisons show that WACCM captures the overall timing and spatial distribution of the observed electron enhancements, indicating a reasonable simulation of flare and SPE‐induced ionization. Both the SPEs and flares caused odd nitrogen increases in the mesosphere. Odd hydrogen produced in the lower mesosphere by the SPEs led to short‐lived ozone decreases of nearly 100%. The flares caused small temperature increases in the lower thermosphere but had no effect on the stratosphere.
Gold-patched graphene nano-stripes for high-responsivity and ultrafast photodetection from the visible to infrared regime
Authors: Cakmakyapan Semih , Lu Ping Keng , Navabi Aryan , Jarrahi Mona 
Published: June 2018

AbstractGraphene is a very attractive material for broadband photodetection in hyperspectral imaging and sensing systems. However, its potential use has been hindered by tradeoffs between the responsivity, bandwidth, and operation speed of existing graphene photodetectors. Here, we present engineered photoconductive nanostructures based on gold-patched graphene nano-stripes, which enable simultaneous broadband and ultrafast photodetection with high responsivity. These nanostructures merge the advantages of broadband optical absorption, ultrafast photocarrier transport, and carrier multiplication within graphene nano-stripes with the ultrafast transport of photocarriers to gold patches before recombination. Through this approach, high-responsivity operation is realized without the use of bandwidth-limiting and speed-limiting quantum dots, defect states, or tunneling barriers. We demonstrate high-responsivity photodetection from the visible to infrared regime (0.6 A/W at 0.8 μm and 11.5 A/W at 20 μm), with operation speeds exceeding 50 GHz. Our results demonstrate improvement of the response times by more than seven orders of magnitude and an increase in bandwidths of one order of magnitude compared to those of higher-responsivity graphene photodetectors based on quantum dots and tunneling barriers.
Dynamics and interactions of highly resolved marine plankton via automated high-frequency sampling
Authors: Needham David M , Fichot Erin B , Wang Ellice , Berdjeb Lyria , Cram Jacob A , Fichot Cédric G , Fuhrman Jed A 
Published: June 2018

Abstract
Short timescale observations are valuable for understanding microbial ecological processes. We assessed dynamics in relative abundance and potential activities by sequencing the small sub-unit ribosomal RNA gene (rRNA gene) and rRNA molecules (rRNA) of Bacteria, Archaea, and Eukaryota once to twice daily between March 2014 and May 2014 from the surface ocean off Catalina Island, California. Typically Ostreococcus, Braarudosphaera, Teleaulax, and Synechococcus dominated phytoplankton sequences (including chloroplasts) while SAR11, Sulfitobacter, and Fluviicola dominated non-phytoplankton Bacteria and Archaea. We observed short-lived increases of diatoms, mostly Pseudo-nitzschia and Chaetoceros, with quickly responding Bacteria and Archaea including Flavobacteriaceae (Polaribacter & Formosa), Roseovarius, and Euryarchaeota (MGII), notably the exact amplicon sequence variants we observed responding similarly to another diatom bloom nearby, 3 years prior. We observed correlations representing known interactions among abundant phytoplankton rRNA sequences, demonstrating the biogeochemical and ecological relevance of such interactions: (1) The kleptochloroplastidic ciliate Mesodinium 18S rRNA gene sequences and a single Teleaulax taxon (via 16S rRNA gene sequences) were correlated (Spearman r = 0.83) yet uncorrelated to a Teleaulax 18S rRNA gene OTU, or any other taxon (consistent with a kleptochloroplastidic or karyokleptic relationship) and (2) the photosynthetic prymnesiophyte Braarudosphaera bigelowii and two strains of diazotrophic cyanobacterium UCYN-A were correlated and each taxon was also correlated to other taxa, including B. bigelowii to a verrucomicrobium and a dictyochophyte phytoplankter (all r &gt; 0.8). We also report strong correlations (r &gt; 0.7) between various ciliates, bacteria, and phytoplankton, suggesting interactions via currently unknown mechanisms. These data reiterate the utility of high-frequency time series to show rapid microbial reactions to stimuli, and provide new information about in situ dynamics of previously recognized and hypothesized interactions.
Signal beyond nutrient, fructose, exuded by an arbuscular mycorrhizal fungus triggers phytate mineralization by a phosphate solubilizing bacterium
Authors: Zhang Lin , Feng Gu , Declerck Stéphane 
Published: June 2018

Abstract
Cooperation is a prevalent phenomenon in nature and how it originates and maintains is a fundamental question in ecology. Many efforts have been made to understand cooperation between individuals in the same species, while the mechanisms enabling cooperation between different species are less understood. Here, we investigated under strict in vitro culture conditions if the exchange of carbon and phosphorus is pivotal to the cooperation between the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis and the phosphate solubilizing bacterium (PSB) Rahnella aquatilis. We observed that fructose exuded by the AMF stimulated the expression of phosphatase genes in the bacterium as well as the rate of phosphatase release into the growth medium by regulating its protein secretory system. The phosphatase activity was subsequently increased, promoting the mineralization of organic phosphorus (i.e., phytate) into inorganic phosphorus, stimulating simultaneously the processes involved in phosphorus uptake by the AMF. Our results demonstrated for the first time that fructose not only is a carbon source, but also plays a role as a signal molecule triggering bacteria-mediated organic phosphorus mineralization processes. These results highlighted the molecular mechanisms by which the hyphal exudates play a role in maintaining the cooperation between AMF and bacteria.
Eavesdropping and crosstalk between secreted quorum sensing peptide signals that regulate bacteriocin production in Streptococcus pneumoniae
Authors: Miller Eric L , Kjos Morten , Abrudan Monica I , Roberts Ian S , Veening Jan-Willem , Rozen Daniel E 
Published: June 2018

Abstract
Quorum sensing (QS), where bacteria secrete and respond to chemical signals to coordinate population-wide behaviors, has revealed that bacteria are highly social. Here, we investigate how diversity in QS signals and receptors can modify social interactions controlled by the QS system regulating bacteriocin secretion in Streptococcus pneumoniae, encoded by the blp operon (bacteriocin-like peptide). Analysis of 4096 pneumococcal genomes detected nine blp QS signals (BlpC) and five QS receptor groups (BlpH). Imperfect concordance between signals and receptors suggested widespread social interactions between cells, specifically eavesdropping (where cells respond to signals that they do not produce) and crosstalk (where cells produce signals that non-clones detect). This was confirmed in vitro by measuring the response of reporter strains containing six different blp QS receptors to cognate and non-cognate peptides. Assays between pneumococcal colonies grown adjacent to one another provided further evidence that crosstalk and eavesdropping occur at endogenous levels of signal secretion. Finally, simulations of QS strains producing bacteriocins revealed that eavesdropping can be evolutionarily beneficial even when the affinity for non-cognate signals is very weak. Our results highlight that social interactions can mediate intraspecific competition among bacteria and reveal that competitive interactions can be modified by polymorphic QS systems.
Long non-coding RNA HOTAIR promotes osteoarthritis progression via miR-17-5p/FUT2/β-catenin axis
Authors: Hu Jialei , Wang Zi , Shan Yujia , Pan Yue , Ma Jia , Jia Li 
Published: June 2018

AbstractOsteoarthritis (OA) is a chronic joint disease and hard to cure at present. Accumulating evidence suggests long noncoding RNA-HOTAIR (lncRNA-HOTAIR) plays important role in OA progression. However, the underlying molecular mechanism of HOTAIR in OA progression has not been well elucidated. In the present study, we identified that HOTAIR level was upregulated in OA cartilage tissues. High expression of HOTAIR was correlated with modified Mankin scale, extracellular matrix (ECM) degradation and chondrocytes apoptosis. The expression of miR-17-5p was down-regulated, while alpha-1, 2 fucosyltransferase 2 (FUT2) was increased in OA progression. Luciferase reporter and RNA immunoprecipitation (RIP) assays indicated that HOTAIR could directly bind to miR-17-5p and indirectly upregulate FUT2 level. Functional investigation revealed HOTAIR and FUT2 aggravated ECM degradation and chondrocytes apoptosis, and this effect could be reversed by miR-17-5p. Altered FUT2 modulated the activity of wnt/β-catenin pathway and HOTAIR/miR-17-5p also mediated wnt/β-catenin pathway through FUT2. Collectively, our findings indicated that HOTAIR/miR-17-5p/FUT2 axis contributed to OA progression via wnt/β-catenin pathway, which might provide novel insights into the function of lncRNA-driven in OA.
Mitotic polarization of transcription factors during asymmetric division establishes fate of forming cancer cells
Authors: Liu Yongqing , Siles Laura , Lu Xiaoqin , Dean Kevin C. , Cuatrecasas Miriam , Postigo Antonio , Dean Douglas C. 
Published: June 2018

AbstractA model of K-Ras-initiated lung cancer was used to follow the transition of precancerous adenoma to adenocarcinoma. In hypoxic, Tgf-β1-rich interiors of adenomas, we show that adenoma cells divide asymmetrically to produce cancer-generating cells highlighted by epithelial mesenchymal transition and a CD44/Zeb1 loop. In these cells, Zeb1 represses the Smad inhibitor Zeb2/Sip1, causing Pten loss and launching Tgf-β1 signaling that drives nuclear translocation of Yap1. Surprisingly, the nuclear polarization of transcription factors during mitosis establishes parent and daughter fates prior to cytokinesis in sequential asymmetric divisions that generate cancer cells from precancerous lesions. Mutation or knockdown of Zeb1 in the lung blocked the production of CD44hi, Zeb1hi cancer-generating cells from adenoma cells. A CD44/Zeb1 loop then initiates two-step transition of precancerous cells to cancer cells via a stable intermediate population of cancer-generating cells. We show these initial cancer-generating cells are independent of cancer stem cells generated in tumors by p53-regulated reprogramming of existing cancer cells.
Conformational switching of the pseudokinase domain promotes human MLKL tetramerization and cell death by necroptosis
Authors: Petrie Emma J. , Sandow Jarrod J. , Jacobsen Annette V. , Smith Brian J. , Griffin Michael D. W. , Lucet Isabelle S. , Dai Weiwen , Young Samuel N. , Tanzer Maria C. , Wardak Ahmad , Liang Lung-Yu , Cowan Angus D. , Hildebrand Joanne M. , Kersten Wilhelmus J. A. , Lessene Guillaume , Silke John , Czabotar Peter E. , Webb Andrew I. , Murphy James M. 
Published: June 2018

AbstractNecroptotic cell death is mediated by the most terminal known effector of the pathway, MLKL. Precisely how phosphorylation of the MLKL pseudokinase domain activation loop by the upstream kinase, RIPK3, induces unmasking of the N-terminal executioner four-helix bundle (4HB) domain of MLKL, higher-order assemblies, and permeabilization of plasma membranes remains poorly understood. Here, we reveal the existence of a basal monomeric MLKL conformer present in human cells prior to exposure to a necroptotic stimulus. Following activation, toggling within the MLKL pseudokinase domain promotes 4HB domain disengagement from the pseudokinase domain αC helix and pseudocatalytic loop, to enable formation of a necroptosis-inducing tetramer. In contrast to mouse MLKL, substitution of RIPK3 substrate sites in the human MLKL pseudokinase domain completely abrogated necroptotic signaling. Therefore, while the pseudokinase domains of mouse and human MLKL function as molecular switches to control MLKL activation, the underlying mechanism differs between species.
Effects of overlayer capping and lattice strain on perpendicular magnetic anisotropy of TM|FePt|MgO heterostructures
Authors: Han Xiaocui , Cui Hong , Liu Bo , Tian Cunling , Wang Junzhong , Chen Hong , Yuan Hongkuan 
Published: June 2018

AbstractMagnetic tunnel junctions (MTJs) with ferromagnetic electrodes possessing the strong perpendicular magnetocrystalline anisotropy (PMA) are of great interest as they have a potential for realizing next-generation high-density non-volatile memory and logic chips. To date, it is an urgent and critical issue to continuously promote the PMAs through feasible modifications such as the substitution of ferromagnetic layers as well as the overlayer coating on them. Here, we perform the relativistic first principles calculations of TM|L10-FePt|MgO sandwich systems, and demonstrate that the changes in PMAs by capping TM layers are always giant and positive, e.g., PMA of Fe|FePt|MgO, the largest one among all our studied systems, is about 2 times larger than that of FePt|MgO. The interfacial PMAs at TM|FePt and FePt|MgO interfaces are extracted to be 3.31~9.40 meV and 3.32 meV, respectively, which are at least 3 times larger than 0.93 meV/ML of interior FePt layer. We illustratively verify that PMAs of TM|FePt|MgO can be turned in a large range by varying the TM layer and in-plane strain. Our results and model analyses provide useful insights for how these magnetic quantities are linked, and pave a way for the promotion of PMAs of FePt-based heterostructures via contact with TM overlayers.
Quantitative association analysis between PM2.5 concentration and factors on industry, energy, agriculture, and transportation
Authors: Zhang Nan , Huang Hong , Duan Xiaoli , Zhao Jinlong , Su Boni 
Published: June 2018

AbstractRapid urbanization is causing serious PM2.5 (particulate matter ≤2.5 μm) pollution in China. However, the impacts of human activities (including industrial production, energy production, agriculture, and transportation) on PM2.5 concentrations have not been thoroughly studied. In this study, we obtained a regression formula for PM2.5 concentration based on more than 1 million PM2.5 recorded values and data from meteorology, industrial production, energy production, agriculture, and transportation for 31 provinces of mainland China between January 2013 and May 2017. We used stepwise regression to process 49 factors that influence PM2.5 concentration, and obtained the 10 primary influencing factors. Data of PM2.5 concentration and 10 factors from June to December, 2017 was used to verify the robustness of the model. Excluding meteorological factors, production of natural gas, industrial boilers, and ore production have the highest association with PM2.5 concentration, while nuclear power generation is the most positive factor in decreasing PM2.5 concentration. Tianjin, Beijing, and Hebei provinces are the most vulnerable to high PM2.5 concentrations caused by industrial production, energy production, agriculture, and transportation (IEAT).
Development of a Novel Backbone Cyclic Peptide Inhibitor of the Innate Immune TLR/IL1R Signaling Protein MyD88
Authors: Dishon Shira , Schumacher Adi , Fanous Joseph , Talhami Alaa , Kassis Ibrahim , Karussis Dimitrios , Gilon Chaim , Hoffman Amnon , Nussbaum Gabriel 
Published: June 2018

AbstractMyD88 is a cytoplasmic adaptor protein that plays a central role in signaling downstream of the TLRs and the IL1R superfamily. We previously demonstrated that MyD88 plays a critical role in EAE, the murine model of multiple sclerosis, and showed that the MyD88 BB-loop decoy peptide RDVLPGT ameliorates EAE. We now designed and screened a library of backbone cyclized peptides based on the linear BB loop peptide, to identify a metabolically stable inhibitor of MyD88 that retains the binding properties of the linear peptide. We identified a novel cyclic peptide protein mimetic that inhibits inflammatory responses to TLR ligands, and NFκB activation in response to IL-1 activation. The inhibitor, c(MyD 4-4), is metabolically stable in comparison to the linear peptide, blocks MyD88 in a specific manner, and inhibits MyD88 function by preventing MyD88 dimerization. Finally, treatment of mice with c(MyD 4-4) reduced the severity of clinical disease in the murine EAE model of multiple sclerosis. Thus, modulation of MyD88-dependent signaling using c(MyD 4-4) is a potential therapeutic strategy to lower innate immune inflammation in autoimmune CNS disease.
Amelioration of High Fructose-Induced Cardiac Hypertrophy by Naringin
Authors: Park Jung Hyun , Ku Hyeong Jun , Kim Jae Kyeom , Park Jeen-Woo , Lee Jin Hyup 
Published: June 2018

AbstractHeart failure is a frequent unfavorable outcome of pathological cardiac hypertrophy. Recent increase in dietary fructose consumption mirrors the rise in prevalence of cardiovascular diseases such as cardiac hypertrophy leading to concerns raised by public health experts. Mitochondria, comprising 30% of cardiomyocyte volume, play a central role in modulating redox-dependent cellular processes such as metabolism and apoptosis. Furthermore, mitochondrial dysfunction is a key cause of pathogenesis of fructose-induced cardiac hypertrophy. Naringin, a major flavanone glycoside in citrus species, has displayed strong antioxidant potential in models of oxidative stress. In this study, we evaluated protective effects of naringin against fructose-induced cardiac hypertrophy and associated mechanisms of action, usingin vitroandin vivomodels. We found that naringin suppressed mitochondrial ROS production and mitochondrial dysfunction in cardiomyocytes exposed to fructose and consequently reduced cardiomyocyte hypertrophy by regulating AMPK-mTOR signaling axis. Furthermore, naringin counteracted fructose-induced cardiomyocyte apoptosis, and this function of naringin was linked to its ability to inhibit ROS-dependent ATM-mediated p53 signaling. This result was supported by observations inin vivomouse model of cardiac hypertrophy. These findings indicate a novel role for naringin in protecting against fructose-induced cardiac hypertrophy and suggest unique therapeutic strategies for prevention of cardiovascular diseases.