bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and versatile polarization control of X-ray by segmented cross undulator at SPring-8
Authors: Miyawaki Jun , Yamamoto Susumu , Hirata Yasuyuki , Horio Masafumi , Harada Yoshihisa , Matsuda Iwao 
Published: November 2021

AbstractAn X-ray is the well-known probe to examine structure of materials, including our own bodies. The X-ray beam, especially at the wavelength of nanometers, has also become significant to directly investigate electronic states of a sample. Such an X-ray is called a soft X-ray and polarization dependence of the light-matter interaction further unveils the microscopic properties, such as orbitals or spins of electrons. Generation of high brilliant beams of the polarized X-ray has linked to development of our experimental science, and it has been made by radiation from relativistic electrons at the synchrotron radiation facilities over the world. Recently, we constructed a new polarization-controlled X-ray source, the segmented cross undulator, at SPring-8, the largest synchrotron radiation facility in the world. The operation is based on interference of X-ray beams, which is sharply contrast to the conventional method of regulating electron trajectory by the mechanical control of magnets. The paradigm shift opened the measurement innovations and allowed us to design new experimental approaches to capture signals that have been hidden in materials. The present review describes the novel X-ray source with the principle of operation and the technical details of optimization. Examples of the frontier spectroscopies that use unique optical properties of the source are introduced, followed by the future prospects for next generation synchrotron radiation facilities.
Time‐Scale Dependent Relations Between Earth Observation Based Proxies of Vegetation Productivity
Authors: Linscheid Nora , Mahecha Miguel D. , Rammig Anja , Carvalhais Nuno , Gans Fabian , Nelson Jacob A. , Walther Sophia , Weber Ulrich , Reichstein Markus 
Published: November 2021

AbstractMuch uncertainty remains in measuring the inter‐annual and longer‐term dynamics of vegetation gross and net primary productivity (GPP, NPP) and the connected land carbon sink. Potential for better GPP estimation lies in newer satellite products representing different processes or vegetation states, but how they capture interannual GPP dynamics remains to be explored. Here, we differentiate shorter‐ and longer‐term vegetation dynamics and their drivers for several Earth‐observation‐based vegetation proxies and a GPP estimate using time series decomposition. We find that relations between proxies can significantly differ between time scales, along land cover and climate gradients. For GPP estimated at FLUXNET sites, seasonal and multiannual slopes differ by at least 25% for half of the cases investigated, indicating considerable mismatch if multiannual relations were derived from seasonal slopes. Considering time‐scale‐specific sensitivities between proxies of vegetation productivity may improve estimates of interannual variability in vegetation productivity.
Does Regional Hydroclimate Change Scale Linearly With Global Warming?
Authors: Lehner Flavio , Coats Sloan 
Published: November 2021

AbstractMany aspects of climate change scale linearly with global warming. However, nonlinear changes are possible, especially in the context of hydroclimate, and under emissions scenarios with stabilized global temperature, as aspired to by current climate targets. In CMIP5 and 6, a progressively larger land area shows nonlinear changes as a function of global warming when considering precipitation, evaporation, and soil moisture, with the latter showing nonlinearity over ∼50% of global land. Using ensemble simulations with the Community Earth System Model 1, in which individual forcing factors are held constant, we illustrate how nonadditive responses to anthropogenic greenhouse gases and industrial and fire‐related aerosols can yield complex soil moisture changes in certain regions. This complexity contributes to uncertainty in regional soil moisture projections and suggests that the timing of, as well as model response uncertainty to, future aerosol reductions will have significant impacts on regional hydroclimate change as global temperatures stabilize.
Magnitude and Uncertainty of Nitrous Oxide Emissions From North America Based on Bottom‐Up and Top‐Down Approaches: Informing Future Research and National Inventories
Authors: Xu R. , Tian H. , Pan N. , Thompson R. L. , Canadell J. G. , Davidson E. A. , Nevison C. , Winiwarter W. , Shi H. , Pan S. , Chang J. , Ciais P. , Dangal S. R. S. , Ito A. , Jackson R. B. , Joos F. , Lauerwald R. , Lienert S. , Maavara T. , Millet D. B. , Raymond P. A. , Regnier P. , Tubiello F. N. , Vuichard N. , Wells K. C. , Wilson C. , Yang J. , Yao Y. , Zaehle S. , Zhou F. 
Published: November 2021

AbstractWe synthesized N2O emissions over North America using 17 bottom‐up (BU) estimates from 1980–2016 and five top‐down (TD) estimates from 1998 to 2016. The BU‐based total emission shows a slight increase owing to U.S. agriculture, while no consistent trend is shown in TD estimates. During 2007–2016, North American N2O emissions are estimated at 1.7 (1.0–3.0) Tg N yr−1 (BU) and 1.3 (0.9–1.5) Tg N yr−1 (TD). Anthropogenic emissions were twice as large as natural fluxes from soil and water. Direct agricultural and industrial activities accounted for 68% of total anthropogenic emissions, 71% of which was contributed by the U.S. Our estimates of U.S. agricultural emissions are comparable to the EPA greenhouse gas (GHG) inventory, which includes estimates from IPCC tier 1 (emission factor) and tier 3 (process‐based modeling) approaches. Conversely, our estimated agricultural emissions for Canada and Mexico are twice as large as the respective national GHG inventories.
Emerging Global Ocean Deoxygenation Across the 21st Century
Authors: Gong Hongjing , Li Chao , Zhou Yuntao 
Published: November 2021

AbstractOcean deoxygenation (i.e., loss of oxygen) due to climate change can result in marine environment deterioration. Here we applied a time of emergence method to detect when and where the signals of oceanic oxygen change would emerge from its internal variability in the epipelagic, mesopelagic, and bathypelagic zones. The results from climate model simulations under low‐emission conditions (XGHG) and high‐emission conditions (RCP8.5) show that the emergence of deoxygenation is projected to occur earliest and most widespread in the mesopelagic zone. Under the RCP8.5 scenario, more than 72% of the global ocean is projected to experience an emergence of deoxygenation before 2080 for all three vertical zones. Regionally, the emergence of deoxygenation is projected to be widespread below the epipelagic zone of the western North Pacific, North Atlantic, and Southern Oceans before 2080. ToE and the spatial coverage of deoxygenation are both important for fisheries and other marine resources protection.
The Phase‐Locking of Tropical North Atlantic and the Contribution of ENSO
Authors: Chen Han‐Ching , Jin Fei‐Fei , Jiang Leishan 
Published: November 2021

AbstractThe Tropical North Atlantic (TNA) is characterized by significant interannual variability in sea surface temperature (SST), which is phase‐locked to the boreal spring. In this study, the phase‐locking of TNA is investigated by adopting a linear stochastic‐dynamical model (SDM) using seasonally modulated TNA feedbacks together with the seasonal modulation of ENSO forcing. In the observations, the role of local TNA feedbacks and ENSO forcing in TNA phase‐locking are equivalently important with both preferring the peak of TNA variability to appear in the boreal spring. Besides, the seasonal modulation of TNA feedbacks and ENSO forcing strength are both mainly controlled by thermodynamic processes. In most climate models, the contribution of ENSO on TNA phase‐locking is weaker than that in observations. The strength of ENSO‐related TNA phase‐locking is highly correlated with the relationship between ENSO and TNA, which is mainly determined by the amplitude of ENSO and its teleconnection patterns.
Impact of Formation Pathways on Secondary Inorganic Aerosol During Haze Pollution in Beijing: Quantitative Evidence From High‐Resolution Observation and Modeling
Authors: Gao Jie , Li Yiming , Li Jiayun , Shi Guoliang , Liu Zirui , Han Bo , Tian Xiao , Wang Yuesi , Feng Yinchang , Russell Armistead G. 
Published: November 2021

AbstractSecondary inorganic aerosol (especially SNA: sulfate, nitrate, and ammonium) formed from different pathways, account for significant proportions of ambient particulate matter during haze events. For the first time, we quantitatively explored contributions from different SNA formation pathways by an online monitoring AMS instrument and 3‐dimension factor analysis PMF3 model, which is called “SNA formation pathway apportionment”. Three formation process were identified: NH4NO3 heterogeneous phase reactions (NH4NO3‐heter), (NH4)2SO4 gas phase reactions ((NH4)2SO4‐gas), and mixed NH4NO3 and (NH4)2SO4 aqueous phase processes (S&N‐aque). Their overall contributions to SNA were 25.7%, 22.1%, and 52.2%, respectively. Moreover, (NH4)2SO4‐gas contributed mainly in clean (52.1%); S&N‐aque got the highest contribution in haze episode (69.6%); while sulfate gas phase formations were also found in haze stage (10.3%). The quantitative findings from this work provide hard evidence that aqueous phase processes (including sulfate aqueous phase reactions and nitrate gas‐particle partition) were major drivers for SNA increasing.
Pressure Destabilizes Oxygen Vacancies in Bridgmanite
Authors: Fei Hongzhan , Liu Zhaodong , Huang Rong , Kamada Seiji , Hirao Naohisa , Kawaguchi Saori , McCammon Catherine , Katsura Tomoo 
Published: November 2021

AbstractBridgmanite may contain a large proportion of ferric iron in its crystal structure in the forms of FeFeO3and MgFeO2.5components. We investigated the pressure dependence of FeFeO3and MgFeO2.5contents in bridgmanite coexisting with MgFe2O4‐phase and with or without ferropericlase in the MgO‐SiO2‐Fe2O3ternary system at 2,300 K, 33 and 40 GPa. Together with the experiments at 27 GPa reported in Fei et al. (2020,https://doi.org/10.1029/2019GL086296), our results show that the FeFeO3and MgFeO2.5contents in bridgmanite decrease from 7.6 to 5.3 mol % and from 2 to 3 mol % to nearly zero, respectively, with increasing pressure from 27 to 40 GPa. Accordingly, the total Fe3+decreases from 0.18 to 0.11 pfu. The formation of oxygen vacancies (MgFeO2.5component) in bridgmanite is therefore dramatically suppressed by pressure. Oxygen vacancies can be produced by ferric iron in Fe3+‐rich bridgmanite under the topmost lower mantle conditions, but the concentration should decrease rapidly with increasing pressure. The variation of oxygen‐vacancy content with depth may potentially affect the physical properties of bridgmanite and thus affect mantle dynamics.
High Electrical Conductivity of Olivine at Oxidizing Conditions of the Shallow Mantle and Geophysical Implications
Authors: Liu Hanyong , Zhu Qiao , Xu Xisheng , Fei Hongzhan , Yang Xiaozhi 
Published: November 2021

AbstractHigh electrical conductivity in the shallow mantle has long been recognized by electromagnetic depth soundings, but the origin remains debated. Various candidates, of which the two most popular are water enrichment in olivine (the dominant mineral in the upper mantle) and partial melt, have been proposed to explain the electrical anomalies. These models nearly exclusively assume a very low conductivity for dry or water‐poor olivine. Here, we show by experimental work that, under well‐controlled conditions of pressure, temperature, oxygen fugacity (fO2), and water inventory, the conductivity of olivine is in fact insensitive to water content at mantle temperature (e.g., >1,000°C), although the enhancement is substantial at relatively low temperature. In particular, the conductivity of olivine at temperature beyond ∼1,000°C is strikingly high, about 0.01–0.1 S/m, at the oxidizing conditions of the shallow mantle. The high conductivity is comparable to the geophysically measured high conductivity in many conductive regions of the shallow mantle. The results provide a new framework for understanding the electrical anomalies and electrical structure of the shallow mantle.
Multivariate Statistical Appraisal of Regional Susceptibility to Induced Seismicity: Application to the Permian Basin, SW United States
Authors: Hicks Stephen P. , Goes Saskia , Whittaker Alexander C. , Stafford Peter J. 
Published: November 2021

AbstractInduced earthquake sequences are typically interpreted through causal triggering mechanisms. However, studies of causality rarely consider large regions and why some regions experiencing similar anthropogenic activities remain largely aseismic. Therefore, it can be difficult to forecast seismic hazard at a regional scale. In contrast, multivariate statistical methods allow us to find the combinations of factors that correlate best with seismicity, which can help form the basis of hypotheses that can be subsequently tested with physical models. While strong correlations do not necessarily equate to causality, such a statistical approach is particularly important for large regions with newly emergent seismicity comprising multiple distinct clusters and multifaceted industrial operations. Recent induced seismicity in the Permian Basin provides an excellent test‐bed for multivariate statistical analyses because the main causal industrial and geological factors driving earthquakes in the region remain highly debated. Here, we use logistic regression to retrospectively predict the spatial variation of seismicity across the western Permian Basin. We reproduce the broad distribution of seismicity using a combination of both industrial and geological factors. Our model shows that the proximity to neotectonic faults west of the Delaware Basin is the most important factor that contributes to induced seismicity. The second‐most important factor is salt‐water disposal at shallow depths, with hydraulic fracturing playing a less dominant role. The higher tectonic stressing, together with a poor correlation between seismicity and large‐volume deep salt‐water disposal wells, indicates a very different mechanism of induced seismicity compared to that in Oklahoma.
Overlooked Significant Impact of Trace Metals on the Bacterial Community of PM2.5 in High‐Time Resolution
Authors: Xu Caihong , Chen Hui , Zhu Chao , Li Jiarong , Xie Guangzhao , Zhao Jinzhuo , Zhao Zhuohui , Kan Haidong , Ouyang Huiling , Tang Xu , Guo Xueping , Yin Daqiang , Li Dan , Sui Guodong , Chen Jianmin 
Published: November 2021

AbstractBioaerosol has been increasingly recognized as a hazardous factor, possibly leading to environmental issues and health risks. However, the driving factors were rarely investigated, which impeded comprehensive assessment of environmental quality. Herein ambient trace metals and bacterial community in PM2.5 and their interactions during severe pollution were characterized in high time resolution. The results showed that the mass concentrations of total trace elements in PM2.5 were 1.4–9.4 μg m−3, with As and Cr exceeding the national standard, which might pose health risks to humans, especially children with frequently hand‐to‐mouth activity. The airborne bacterial community structure responded to the changing environmental and meteorological variables including PM2.5, related water‐soluble ions, SO2, O3, temperature, relative humidity, and wind speed. Our results suggested that the trace metal was an overlooked factor in shaping the bacterial community compared to PM2.5, related water‐soluble inorganic ions, trace gases, and meteorological variables based on the aggregated boosted tree. Cd, Ga, and Nb were main trace metals factors affecting the bacterial community. The better knowledge of airborne bacterial diversity in high‐time resolution were essential to assess the environmental quality and help to explore the interactions of bioaerosols and atmospheric pollutants in PM2.5. The synergistic toxicity effects for the combination of trace metals and bioaerosol should be considered in future studies when evaluating their health effects.
The Oligocene‐Miocene Guadalope‐Matarranya Fan, Spain, as an Analog for Long‐Lived, Ridge‐Bearing Megafans on Mars
Authors: Hayden A. T. , Lamb M. P. , Myrow P. M. , Mohrig D. , Williams R. M. E. , Cuevas Martínez J. L. , Cardenas B. T. , Findlay C. P. , Ewing R. C. , McElroy B. J. 
Published: November 2021

AbstractNumerous sedimentary fans on Mars have been studied to better understand the early martian hydrological system. Of particular interest is to estimate the duration of fluvial activity from alluvial fan size by dividing deposit volume by bankfull sediment flux. However, such a calculation requires an intermittency factor—a parameter relating sediment discharge from channel‐filling (bankfull) floods to the long‐term mean sediment discharge—which is poorly constrained. Here, we investigated fluvial fan deposits from the Oligocene–Miocene Caspe Formation, Spain, as an analog to fans on Mars because it has exhumed channel belts that create sinuous ridges in the modern topography, similar to those observed on Mars that are used for paleohydraulics. We made measurements of the thicknesses of dune and bar cross sets within exhumed channel belts at nine field sites to reconstruct bankfull channel depth (∼1.4 m) and bankfull sediment flux (∼0.48 m3/s). We estimated total bed‐material sediment volume of the fan (362 km3) from stratigraphic thickness, the area containing exhumed channel belts, porosity and sand fraction. Combined with previous constraints on depositional timespan (∼6 Myr), we calculated a sediment‐transport intermittency factor of 0.004 (range: 0.0004–0.04). Our approach can be applied to Mars by using remote sensing measurements of fluvial ridge morphology, which indicates the possibility of long depositional timespans exceeding millions of years for martian fans.
TCF7L1 regulates cytokine response and neuroendocrine differentiation of prostate cancer
Authors: Wen Yu-Ching , Liu Yen-Nien , Yeh Hsiu-Lien , Chen Wei-Hao , Jiang Kuo-Ching , Lin Shian-Ren , Huang Jiaoti , Hsiao Michael , Chen Wei-Yu 
Published: November 2021

AbstractNeuroendocrine differentiation (NED) is associated with WNT signaling activation and can be significantly observed after failure of androgen-deprivation therapy (ADT) for prostatic adenocarcinomas. Cytokine signaling is stimulated in NED prostate cancer; however, how ADT-upregulated WNT signaling promotes activation of cytokine signaling and contributes to NED of prostate cancer is poorly understood. In this study, we identified ADT-mediated upregulation of transcription factor 7 like 1 (TCF7L1), which increases the cytokine response and enhances NED of prostate cancer through interleukin (IL)-8/C-X-C motif chemokine receptor type 2 (CXCR2) signaling activation. ADT induced the secretion of WNT4 which upon engagement of TCF7L1 in prostate cancer cells, enhanced IL-8 and CXCR2 expressions. TCF7L1 directly binds to the regulatory sequence region of IL-8 and CXCR2 through WNT4 activation, thus upregulating IL-8/CXCR2 signaling-driven NED and cell motility. Analysis of prostate tissue samples collected from small-cell neuroendocrine prostate cancer (SCPC) and castration-resistant prostate cancer (CRPC) tumors showed an increased intensity of nuclear TCF7L1 associated with CXCR2. Our results suggest that induction of WNT4/TCF7L1 results in increased NED and malignancy in prostate cancer that is linked to dysregulation of androgen receptor signaling and activation of the IL-8/CXCR2 pathway.
Associations between expression of indoleamine 2, 3-dioxygenase enzyme and inflammatory cytokines in patients with first-episode drug-naive Schizophrenia
Authors: Zhang Yan , Shi Han , Yang Ge , Yang Yongfeng , Li Wenqiang , Song Meng , Shao Minglong , Su Xi , Lv Luxian 
Published: November 2021

AbstractThe indoleamine 2,3-dioxygenase (IDO) enzyme is the first rate-limiting enzyme of the tryptophan degradation pathway in which dysfunction of neuroactive metabolites has been implicated in the pathophysiology of schizophrenia. Inflammatory molecules such as pro-inflammatory cytokines could enhance the activity of IDO. There are few studies on the expression of IDO levels and its correlation with levels of inflammatory cytokines in first-episode drug-naive patients with schizophrenia. One hundred inpatients (female = 33, male = 67) with first-episode drug-naive schizophrenia entered a 6-week, double-blind, randomized, placebo-controlled clinical trial. All individuals were assigned celecoxib or placebo combined with risperidone. Serum levels of IDO and six inflammatory cytokines (IL-1β, IL-6, TNF-α IL-17, IL-4, and INF-γ) were measured. The Positive and Negative Syndrome Scale (PANSS) was used to assess the severity of psychotic symptoms. Compared to healthy subjects, patients had significantly elevated levels of IDO and six cytokines at baseline. Over the 6-week treatment period, the decrease in the levels of IDO and TNF-α and the improvement in the PANSS total score, positive scores, and negative scores in the celecoxib group were significantly greater than in the placebo group. There was a significantly positive correlation between IDO levels and the PANSS negative scores and between IDO levels and TNF-α and IFN-γ levels in the celecoxib group. These findings showed abnormal expression of IDO levels which correlated with negative symptoms and pro-inflammatory cytokine levels in patients with first-episode drug-naive schizophrenia, suggesting the important role of IDO in the pathological mechanism of schizophrenia. Registration number: ChiCTR2000041403.
Lactobacillus spp. create a protective micro-ecological environment through regulating the core fucosylation of vaginal epithelial cells against cervical cancer
Authors: Fan Qingjie , Wu Yuanhang , Li Mechou , An Fan , Yao Lulu , Wang Meixian , Wang Xiuying , Yuan Jieli , Jiang Kui , Li Wenzhe , Li Ming 
Published: November 2021

AbstractVaginal dysbiosis often occurs in patients with cervical cancer. The fucosylation of mucosal epithelial cells is closely related to microbial colonization, and play an important role in protecting the vaginal mucosal epithelial cells. However, no reports on the relationship between vaginal dysbiosis and abnormal mucosal epithelial cell fucosylation, and their roles in the occurrence and development of cervical cancer are unavailable. Here we report that core fucosylation levels were significantly lower in the serum, exfoliated cervical cells and tumor tissue of cervical cancer patients. Core fucosyltransferase gene (Fut8) knockout promoted the proliferation and migration of cervical cancer cells. In patients with cervical cancer, the vaginal dysbiosis, and the abundance ofLactobacillus, especiallyL. iners, was significantly reduced. Meanwhile, the abundance ofL.inerswas positively correlated with core fucosylation levels. TheL. inersmetabolite lactate can activate the Wnt pathway through the lactate-Gpr81 complex, which increases the level of core fucosylation in epidermal cells, inhibiting the proliferation and migration of cervical cancer cells, and have application prospects in regulating the vaginal microecology and preventing cervical cancer.