bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying the Impact of Subsurface‐Land Surface Physical Processes on the Predictive Skill of Subseasonal Mesoscale Atmospheric Simulations
Authors: Sulis M. , Keune J. , Shrestha P. , Simmer C. , Kollet S. J. 
Published: July 2018

AbstractIntegrated terrestrial system modeling platforms, which simulate the 3‐D flow of water both in the subsurface and the atmosphere, are expected to improve the realism of predictions through a more detailed physics‐based representation of hydrometeorological processes and feedbacks. We test this expectation by evaluating simulation results from different configurations of an atmospheric model with increasing complexity in the representation of land surface and subsurface physical processes. The evaluation is performed using observations during the (HD(CP)2) Observational Prototype Experiment field campaign in April–May 2013 over western Germany. The augmented model physics do not improve the prediction of daily cumulative precipitation and minimum temperature during this period. Moreover, a cold bias is introduced in the simulated daily maximum temperature, which decreases the performance of the atmospheric model with respect to its standard configuration. The decreased performance in the maximum temperature is traced in part to a higher simulated soil moisture, which shifts surface flux partitioning toward higher latent and lower sensible heat fluxes. The better reproduced air temperature profiles simulated by the standard atmospheric model comes, however, with an overestimated heat flux at the land surface caused by a warm bias in the simulated soil temperature. Simulated atmospheric states do not correlate significantly with differences in soil moisture and temperature; thus, different turbulent flux parameterizations dominate the propagation of the subsurface signal into the atmosphere. The strong influence of the lateral synoptic forcings on the results suggests, however, the need for further investigations encompassing different weather situations or regions with stronger land‐atmosphere coupling conditions.
Sediment Characteristics and Methane Ebullition in Three Subarctic Lakes
Authors: Wik Martin , Johnson Joel E. , Crill Patrick M. , DeStasio Joel P. , Erickson Lance , Halloran Madison J. , Fahnestock M. Florencia , Crawford Maurice K. , Phillips Stephen C. , Varner Ruth K. 
Published: July 2018

AbstractEbullition (bubbling) from climate‐sensitive northern lakes remains an unconstrained source of atmospheric methane (CH4). Although the focus of many recent studies, ebullition is rarely linked to the physical characteristics of lakes. In this study we analyze the sediments of subarctic postglacial lakes and investigate how sediment properties relate to the large spatial variation in CH4 bubble flux, quantified over multiple years using bubble traps. The results show that the sediments from our lakes are rich in total organic carbon, containing 37 kg/m3 on average. This number is roughly 40% higher than the average for yedoma deposits, which have been identified as high CH4 emitters. However, the quantity of total organic carbon is not a useful indicator of high emissions from the study lakes. Neither is the amount of CH4 in the sediment a reliable measure of ebullition potential. Instead, our data point to coarse detritus, partly from buried submerged aquatic vegetation and redeposited peat as spatial controls on fluxes, often in combination with previously established effects of incoming solar radiation and water depth. The results once again highlight the climate sensitivity of northern lakes, indicating that biological responses to warmer waters and increased energy input and heating of organic sediments during longer ice‐free seasons can substantially alter future CH4 emissions.
Observations of Spatial Variations in O/N2 During an Auroral Substorm Using the Multichannel Downlooking Camera on the VISIONS Rocket
Authors: Hecht J. H. , Clemmons J. H. , Conde M. G. , Hampton D. L. , Michell R. G. , Rowland D. E. , Pfaff R. F. , Walterscheid R. L. 
Published: July 2018

AbstractAt 0821 UT on 7 February 2013, during an auroral substorm, the NASA VISIONS rocket was launched northward from Poker Flat Research Range on a flight to approximately 750‐km altitude that terminated in the Arctic Ocean. A subpayload jettisoned on the up leg carried a multichannel optical imager that looked downward and observed the auroral emission through four narrow passband filters. Three of the channels had sufficiently strong signal to allow a measure of the time evolution of the horizontal extent of the electron aurora and changes in the ratio of the column O to the column N2. These data revealed rather rapid changes in this measure of composition over an area larger than would be expected from the changes expected from particle and Joule heating. Although such rapid large changes have been observed previously, and Christensen et al. (1997, https://doi.org/10.1029/97JA01800) had hypothesized that they were due to enhanced turbulent diffusion, this imaging experiment is the first to show their evolution over a large area. On the down leg the camera was able to see the vertical spatial extent of the auroral emission which is consistent with the decrease in O/N2 seen in the downlooking data. The change in this ratio with altitude suggests the deposition of an additional number of low‐energy electrons that would cause a larger decrease in that ratio at higher altitudes.
Time Variations in Ocean Bottom Pressure from a Few Hours to Many Years: In Situ Data, Numerical Models, and GRACE Satellite Gravimetry
Authors: Poropat L. , Dobslaw H. , Zhang L. , Macrander A. , Boebel O. , Thomas M. 
Published: July 2018

AbstractIn situ ocean bottom pressure (OBP) obtained from 154 different locations irregularly scattered over the globe is carefully processed to isolate signals related to the ocean general circulation and large‐scale sea level changes. Comparison against a global numerical ocean model experiment indicates poor correspondence for periods below 24 hr, possibly related to residual tidal signals and small timing errors in the atmospheric forcing applied to the ocean model. Correspondence increases rapidly for periods between 3 and 10 days, where wind‐driven dynamics are already well understood and consequently well implemented into numerical models. Coherence decreases again for periods around 30 days and longer, where processes not implemented into ocean general circulation models as barystatic sea level changes become more important. Correspondence between in situ data and satellite‐based OBP as obtained from the Gravity Recovery and Climate Experiment (GRACE) German Research Centre for Geosciences RL05a gravity fields critically depends on the postprocessing of Level‐2 Stokes coefficients that also includes the selection of appropriate averaging regions for the GRACE‐based mass anomalies. The assessment of other available GRACE Level‐2 products indicates even better fit of more recent solutions as ITSG‐Grace2016 and the Center for Space Research and Jet Propulsion Laboratory RL05 mascons. In view of the strong high‐frequency component of OBP, however, a higher temporal resolution of the oceanic GRACE products would be rather advantageous.
The Uncertainty of Penman‐Monteith Method and the Energy Balance Closure Problem
Authors: Hao Xingming , Zhang Shuhua , Li Weihong , Duan Weili , Fang Gonghuan , Zhang Ying , Guo Bin 
Published: July 2018

AbstractThe Penman‐Monteith (PM) method is considered the most accurate method for estimating reference crop evapotranspiration (ET0). However, the method has obvious flaws in energy balance closure. In this study, the changing trends between latent heat flux of ET0 (LEp) and surface net radiation (Rn) in China were analyzed based on observational data from 800 meteorological stations. The results showed that the multiyear average ratio of LEp/Rn was highest in the warm temperate zone and was lowest in the subfrigid zone of the Tibetan Plateau. Correspondingly, the values of LEp/Rn in these areas were ranged from 1.138 to 0.647. At the site scale, there were 61, 178, and 170 meteorological stations with daily average LEp/Rn values >1 during three periods (from January to April, May to August, and September to December, respectively). The ratio of LEp/Rn showed an obvious surface energy imbalance, and it was extremely obvious in northern China. Meanwhile, it is found that there was also great uncertainty of the ET0, which estimated based on the calculated and measured net radiation. In general, the uncertainty of ET0 was ranged from −0.955 to 1.028 mm/day and the average value of uncertainty was 0.154 mm/day. The uncertainty also showed obviously temporal variation, which was lower during April to October, but was higher in other times. The main cause of the energy balance closure problem was the overestimation of the aerodynamic component of ET0. In view of such situation, this study suggested the two ways to estimate ET0 for different regions.
Performance Analysis and Projected Changes of Agroclimatological Indices Across West Africa Based on High‐Resolution Regional Climate Model Simulations
Authors: Dieng Diarra , Laux Patrick , Smiatek Gerhard , Heinzeller Dominikus , Bliefernicht Jan , Sarr Abdoulaye , Gaye Amadou Thierno , Kunstmann Harald 
Published: July 2018

AbstractIn this study, we analyze a set of agroclimatological indices across West Africa and assess their projected changes for the future. We apply the regional climate model CCLM (COnsortium for Small‐scale MOdelling in CLimate Mode) with a high spatial resolution of 0.11° (approximately 12 km) under current (1981–2010) and future climate conditions, based on the emission scenario RCP4.5. The focus is on purely rainfall‐based indices, that is, the onset (ORS), the cessation (CRS), and the length of the rainy season (LRS) and the joint rainfall‐ and temperature‐based indices, that is, growing degree days (GDD) and the water availability (WAV), derived for maize, sorghum, and pearl millet across Guinea, Savanna, and Sahel. For the present, in general, the CCLM compares well to observations, represented by three different products. However, CCLM shows limitations in the representation of the CRS over Guinea with a delay of >30 days and the GDD and WAV over Sahel with biases up to 30% and 70% for all crops. For the future climate projections, ORS, CRS, and LRS are expected to be delayed up to 2 weeks for most regions, in particular for the period 2071–2100. The GDD is expected to increase by around 8% till 2021–2050 and by around 5% till 2071–2100 for all crops. The WAV is expected to be decreased by up to 10% in 2021–2050, and by up to 24% in 2071–2100 in Sahel, and <12% over Guinea and Savanna in both periods. In particular, we evaluate the added value of the high‐resolution CCLM information for decision support in agricultural management.
Distinct Turbulence Structures in Stably Stratified Boundary Layers With Weak and Strong Surface Shear
Authors: Lan Changxing , Liu Heping , Li Dan , Katul Gabriel G. , Finn Dennis 
Published: July 2018

AbstractTurbulence structures and exchange of momentum and heat in the nocturnal stable boundary layer (SBL) show distinct features under different stability conditions prompting interest in their connection. Here eddy covariance data collected at four different heights on a 62‐m meteorological tower over a large open flat terrain are used to characterize different SBL states and associated turbulence structures. In a SBL characterized by strong near‐surface winds, turbulent eddy sizes scale with their observational heights and the SBL experiences enhanced turbulent mixing of momentum and heat throughout (a state hereafter referred to as a “coupled” state). Conversely, in a decoupled SBL, weak winds occur near the surface and turbulent eddies are depressed and detached from the boundary leading to suppressed vertical mixing and layered SBL profiles. Because the transport of momentum and heat to the surface across SBL layers is determined by turbulent eddies, cross‐layer correlation and the aforementioned SBL coupling states can be delineated by distinct turbulence structures.
Lack of association between PER3 variable number tandem repeat and circadian rhythm sleep–wake disorders
Authors: Hida Akiko , Kitamura Shingo , Kadotani Hiroshi , Uchiyama Makoto , Ebisawa Takashi , Inoue Yuichi , Kamei Yuichi , Mishima Kazuo 
Published: July 2018

AbstractCircadian rhythm sleep–wake disorders (CRSWDs) are characterized by disturbed sleep–wake patterns. We genotyped a PER3 variable number tandem repeat (VNTR) in 248 CRSWD individuals and 925 controls and found no significant association between the VNTR and CRSWDs or morningness–eveningness (diurnal) preferences in the Japanese population. Although the VNTR has been associated with circadian and sleep phenotypes in some other populations, the polymorphism may not be a universal genetic marker.
TBK-binding protein 1 regulates IL-15-induced autophagy and NKT cell survival
Authors: Zhu Lele , Xie Xiaoping , Zhang Lingyun , Wang Hui , Jie Zuliang , Zhou Xiaofei , Shi Jianhong , Zhao Shuli , Zhang Boxiang , Cheng Xuhong , Sun Shao-Cong 
Published: July 2018

AbstractThe cytokine IL-15 mediates development and survival of immune cells, including natural killer T (NKT) cells, but the underlying mechanism of IL-15 function is incompletely understood. Here we show that IL-15 induces autophagy in NKT cells with a mechanism that involves a crucial signaling component, TBK-binding protein 1 (Tbkbp1). Tbkbp1 facilitates activation of the autophagy-initiating kinase Ulk1 through antagonizing the inhibitory action of mTORC1. This antagonization involves the recruitment of an mTORC1-opposing phosphatase to Ulk1. Tbkbp1 deficiency attenuates IL-15-stimulated NKT cell autophagy, and is associated with mitochondrial dysfunction, aberrant ROS production, defective Bcl2 expression and reduced NKT cell survival. Consequently, Tbkbp1-deficient mice have profound deficiency in NKT cells, especially IFN-γ-producing NKT1. We further show that Tbkbp1 regulates IL-15-stimulated autophagy and survival of NK cells. These findings suggest a mechanism of autophagy induction by IL-15, and establish Tbkbp1 as a regulator of NKT cell development and survival.
Remote C−H functionalization using radical translocating arylating groups
Authors: Friese Florian W. , Mück-Lichtenfeld Christian , Studer Armido 
Published: July 2018

AbstractSite selective chemical functionalization at unactivated C(sp3)−H bonds is highly challenging and recent successful studies mostly focus on the use of transition metal catalysis in combination with directing groups. Radical chemistry offers a complementary approach with the Barton and the Hofmann-Löffler-Freytag reactions being landmark contributions in the area of remote C−H functionalization at unactivated aliphatic sites. Herein we introduce the concept of radical translocation arylation at unactivated secondary and tertiary C(sp3)−H bonds in various alcohols. The straightforward two-step sequence comprises an ionic alcohol sulfonylation with especially designed ortho-iodoaryl sulfonyl chlorides followed by a radical cascade reaction including aryl radical generation, remote radical translocation, aryl migration, reduction, and SO2 extrusion to give the corresponding γ-arylated alcohols. Moderate to good yields are obtained, remote C−H arylation occurs with excellent regioselectivity and for secondary C(sp3)−H bonds good to excellent stereoselectivity is achieved.
Nano-photosensitizer based on layered double hydroxide and isophthalic acid for singlet oxygenation and photodynamic therapy
Authors: Gao Rui , Mei Xuan , Yan Dongpeng , Liang Ruizheng , Wei Min 
Published: July 2018

AbstractSinglet oxygen has won a great deal of attention to catalysis and biological studies due to its strong oxidizing properties. However, the photosensitizers which require for the generation of singlet oxygen remain inadequate because of their lack of long-wavelength absorption, weak hydrophilicity, and poor biocompatibility. Here, we develop near-infrared laser activated supramolecular photosensitizers (isophthalic acid/layered double hydroxide nanohybrids) for efficient two-photon photodynamic therapy. The singlet oxygen quantum yield of nanohybrid is up to 0.74. Critically, in vitro tests verify the superior anti-cancer properties of nanohybrid with an IC50 determine to be 0.153 μg mL−1. The nanohybrids take advantage of the superior tissue penetration of 808 nm laser irradiation and exhibit a dramatically strong ability to ablate tumors in vivo, with extremely low toxicity. This work provides the proof of concept that ultralong-lived triplet excitons can function as two-photon-activated photosensitizers for an effective singlet oxygen generation.
A complex of C9ORF72 and p62 uses arginine methylation to eliminate stress granules by autophagy
Authors: Chitiprolu Maneka , Jagow Chantal , Tremblay Veronique , Bondy-Chorney Emma , Paris Geneviève , Savard Alexandre , Palidwor Gareth , Barry Francesca A. , Zinman Lorne , Keith Julia , Rogaeva Ekaterina , Robertson Janice , Lavallée-Adam Mathieu , Woulfe John , Couture Jean-François , Côté Jocelyn , Gibbings Derrick 
Published: July 2018

AbstractMutations in proteins like FUS which cause Amyotrophic Lateral Sclerosis (ALS) result in the aberrant formation of stress granules while ALS-linked mutations in other proteins impede elimination of stress granules. Repeat expansions in C9ORF72, the major cause of ALS, reduce C9ORF72 levels but how this impacts stress granules is uncertain. Here, we demonstrate that C9ORF72 associates with the autophagy receptor p62 and controls elimination of stress granules by autophagy. This requires p62 to associate via the Tudor protein SMN with proteins, including FUS, that are symmetrically methylated on arginines. Mice lacking p62 accumulate arginine-methylated proteins and alterations in FUS-dependent splicing. Patients with C9ORF72 repeat expansions accumulate symmetric arginine dimethylated proteins which co-localize with p62. This suggests that C9ORF72 initiates a cascade of ALS-linked proteins (C9ORF72, p62, SMN, FUS) to recognize stress granules for degradation by autophagy and hallmarks of a defect in this process are observable in ALS patients.
Bistable and photoswitchable states of matter
Authors: Worrell Brady T. , McBride Matthew K. , Lyon Gayla B. , Cox Lewis M. , Wang Chen , Mavila Sudheendran , Lim Chern-Hooi , Coley Hannah M. , Musgrave Charles B. , Ding Yifu , Bowman Christopher N. 
Published: July 2018

AbstractClassical materials readily switch phases (solid to fluid or fluid to gas) upon changes in pressure or heat; however, subsequent reversion of the stimulus returns the material to their original phase. Covalently cross-linked polymer networks, which are solids that do not flow when strained, do not change phase even upon changes in temperature and pressure. However, upon the addition of dynamic cross-links, they become stimuli responsive, capable of switching phase from solid to fluid, but quickly returning to the solid state once the stimulus is removed. Reported here is the first material capable of a bistable switching of phase. A permanent solid to fluid transition or vice versa is demonstrated at room temperature, with inherent, spatiotemporal control over this switch in either direction triggered by exposure to light.
Paeonin extracted from potatoes protects gastric epithelial cells from H2O2-induced oxidative damage in vitro by PI3K/Akt-mediated Nrf2 signaling pathway
Authors: Xiao Jiping , Chen Bo , Wang Qiong , Yang Lijuan , Guo Huachun 
Published: July 2018

AbstractIn this study, it is aimed to investigate the antioxidant mechanism of new extracts from potatoes. Four pigments, namely, Petunin, Paeonin, Malvidin and Pelargonidin, were extracted from potatoes by high performance liquid chromatography (HPLC). Our results showed that the cellular morphology and cell viability were significantly altered in gastric mucosal epithelial cells (GES-1) treated with different hydrogen peroxide (H2O2) concentrations over time (P < 0.05). Paeonin presented the strongest anti-oxidative effects on H2O2-treated cells, in both a dose- and time-dependent manner, determined by ARE-luciferase activity and HO-1 mRNA expression. After pre-treatment with Paeonin in H2O2-exposed cells, Keap1, Nrf2, HO-1 and NQO1 protein expressions were remarkably up-regulated. Furthermore, immunostaining of Nrf2 expression was obviously elevated in the H2O2 + Paeonin group over time. The GSH content in the H2O2 + Paeonin group was notably lower than that in the H2O2 + Paeonin + GSK690693 group. Paeonin promoted cell cycle with augmented Cyclin D1 and p27 protein expressions. Moreover, Paeonin suppressed apoptosis with increased Bcl2, total Caspase3 and total Caspase8 protein expressions and decreased Bax, p-Caspase3 and p-Caspase8 protein expression in H2O2-treated cells. These results suggested that Paeonin might exert an anti-oxidative role by activating Nrf2 signaling pathway with the changes of cell cycle and apoptosis.
Biotic and abiotic drivers of tree seedling recruitment across an alpine treeline ecotone
Authors: Frei Esther R. , Bianchi Eva , Bernareggi Giulietta , Bebi Peter , Dawes Melissa A. , Brown Carissa D. , Trant Andrew J. , Mamet Steven D. , Rixen Christian 
Published: July 2018

AbstractTreeline responses to climate change ultimately depend on successful seedling recruitment, which requires dispersal of viable seeds and establishment of individual propagules in novel environments. In this study, we evaluated the effects of several abiotic and biotic drivers of early tree seedling recruitment across an alpine treeline ecotone. In two consecutive years, we sowed seeds of low- and high-elevation provenances of Larix decidua (European larch) and Picea abies (Norway spruce) below, at, and above the current treeline into intact vegetation and into open microsites with artificially removed surface vegetation, as well as into plots protected from seed predators and herbivores. Seedling emergence and early establishment in treatment and in control plots were monitored over two years. Tree seedling emergence occurred at and several hundred metres above the current treeline when viable seeds and suitable microsites for germination were available. However, dense vegetation cover at lower elevations and winter mortality at higher elevations particularly limited early recruitment. Post-dispersal predation, species, and provenance also affected emergence and early establishment. This study demonstrates the importance of understanding multiple abiotic and biotic drivers of early seedling recruitment that should be incorporated into predictions of treeline dynamics under climate change.