bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mental Health Status of Healthcare Workers During the COVID-19 Outbreak
Authors: Nicolaou Christiana , Menikou Joanna , Lamnisos Demetris , Lubenko Jelena , Presti Giovambattista , Squatrito Valeria , Constantinou Marios , Papacostas Savvas , Aydın Gokcen , Chong Yuen Yu , Chien Wai Tong , Cheng Ho Yu , Ruiz Francisco J. , Segura-Vargas Miguel A. , Garcia-Martin Maria B. , Obando-Posada Diana P. , Vasiliou Vasilis S. , McHugh Louise , Höfer Stefan , Baban Adriana , Neto David Dias , da Silva Ana Nunes , Monestès Jean-Louis , Alvarez-Galvez Javier , Paez-Blarrina Marisa , Montesinos Francisco , Valdivia-Salas Sonsoles , Ori Dorottya , Kleszcz Bartosz , Lappalainen Raimo , Ivanović Iva , Gosar David , Dionne Frederick , Merwin Rhonda M. , Kassianos Angelos P. , Karekla Maria , Gloster Andrew T. 
Published: September 2021

Abstract. Background: The COVID-19 pandemic is a massive health crisis that has exerted enormous physical and psychological pressure. Mental healthcare for healthcare workers (HCWs) should receive serious consideration. This study served to determine the mental-health outcomes of 1,556 HCWs from 45 countries who participated in the COVID-19 IMPACT project, and to examine the predictors of the outcomes during the first pandemic wave. Methods: Outcomes assessed were self-reported perceived stress, depression symptom, and sleep changes. The predictors examined included sociodemographic factors and perceived social support. Results: The results demonstrated that half of the HCWs had moderate levels of perceived stress and symptoms of depression. Half of the HCWs ( n = 800, 51.4%) had similar sleeping patterns since the pandemic started, and one in four slept more or slept less. HCWs reported less perceived stress and depression symptoms and higher levels of perceived social support than the general population who participated in the same project. Predictors associated with higher perceived stress and symptoms of depression among HCWs included female sex, not having children, living with parents, lower educational level, and lower social support. Discussion: The need for establishing ways to mitigate mental-health risks and adjusting psychological interventions and support for HCWs seems to be significant as the pandemic continues.
Symbiont Photosynthesis and Its Effect on Boron Proxies in Planktic Foraminifera
Authors: Hönisch Bärbel , Fish Carina R. , Phelps Samuel R. , Haynes Laura L. , Dyez Kelsey , Holland Kate , Fehrenbacher Jennifer , Allen Katherine A. , Eggins Stephen M. , Goes Joaquim I. 
Published: September 2021

AbstractBoron proxies in the calcium carbonate shells of planktic foraminifera are sensitive to seawater acidity, but B/Ca ratios and isotopic composition (i.e., δ11B) recorded by different foraminifer species grown under identical environmental conditions differ significantly and systematically. Specifically, Globigerinoides ruber displays higher B/Ca and δ11B than Trilobatus sacculifer and Orbulina universa. It has been hypothesized that these differences are caused by species‐specific rates of symbiont photosynthesis and habitat depth with greater symbiont photosynthesis elevating the microenvironmental pH of G. ruber relative to T. sacculifer and O. universa. Here we test this hypothesis by applying fast repetition rate fluorometry (FRRF), Chlorophyll a quantification, and symbiont counts in laboratory grown specimens of G. ruber (pink), T. sacculifer and O. universa to study species‐specific differences in symbiont photochemical quantum efficiencies. In addition, we report B/Ca shell profiles measured by laser ablation on the same specimens previously monitored by FRRF, and δ11B data of discrete populations of all three species grown under high and low light conditions in the laboratory. While the light experiments document that symbiont photosynthesis elevates pH and/or δ11B in the calcifying microenvironment of all three foraminifer species, the FRRF, Chl. a and symbiont abundance data are relatively uniform among the three species and do not scale consistently with intrashell B/Ca, or with observed species‐specific offsets in B/Ca or δ11B. Implications of these findings for foraminiferal physiology and biomineralization processes are discussed.
Beyond 4 × 100 Gbps Optical Backhaul Network With DSP Assistance Based Nonlinear Impairments Mitigation
Authors: Ali Farman , Armghan Ammar , Muhammad Fazal , Habib Usman , Ali Asar , Qamar Muhamamd Salman , Ali Usman , Khan Maqsood Ahmad 
Published: September 2021

AbstractBackhaul networking is the highlighted objective of today telecommunication structure. Additionally, the backhaul networking can be possible easily utilizing optical fiber networks (OFNs). This paper studies 4 × 100 Gbps framework of long haul capacity wavelength division multiplexing (WDM) system, taking into account the impairments of nonlinearities, amplified spontaneous emission (ASE) fiber dispersion. Digital signal processing based receiver is proposed to maintain performance of OFNs in presence of nonlinear issues. The complete procedure of proposed WDM based OFNs is verified theoretically. The simulation analysis proved the validation of presented model against nonlinear impairments and provides 2.1 bit error rate (BER) at 25 and 50 GHz channel spacing, 90 μm2 effective area and 500 km transmission length.
On the Implementation and Usability of Crystal Preferred Orientation Evolution in Geodynamic Modeling
Authors: Fraters M. R. T. , Billen M. I. 
Published: September 2021

AbstractFlow in the Earth's mantle causes the preferred orientation of crystals called lattice/crystal preferred orientation (LPO or CPO). This preferred orientation is one of the main reasons why seismic anisotropy is observed. Seismic anisotropy observations could therefore be used to constrain the mantle flow in geodynamic models through tracking CPO evolution, and computing the resulting elastic tensor and the anisotropy predicted at the surface. Even though there are many types of CPO models, only a few studies include CPO calculations due to the complexity and computational cost. Here, we implemented an extended version of the CPO model D‐Rex into the open‐source community geodynamics code ASPECT. We show that the implementation is correct, how to use it, and that it is feasible and important to use in large 3D models. We also show that it is important to calculate CPO, especially for models focusing on plate boundary of smaller scale flow because the resulting fast axis directions can greatly deviate from the flow direction. The added infrastructure will also allow for future enhancement, testing, and even replacement of the CPO model.
Variability of Natural Methane Bubble Release at Southern Hydrate Ridge
Authors: Marcon Yann , Kelley Deborah , Thornton Blair , Manalang Dana , Bohrmann Gerhard 
Published: September 2021

AbstractCurrent estimations of seabed methane release into the ocean (0.4–48 Tg yr−1) are based on short‐term observations and implicitly assume that fluxes are constant over time. However, the intensity of gas seepage varies significantly throughout a seep lifetime. We used instruments operated by the Ocean Observatories Initiative's Regional Cabled Array to monitor variations of gas emissions over the entire Southern Hydrate Ridge summit. We show that bubble plumes emanate from distinct and persistent vents. Multiple plumes can occur within each vent and the location of their outlets may shift progressively. Active bubble plumes vary temporally in number and intensity, even within single vents. Gas emission fluctuations are partly periodic and linked to the local tide. However, short‐term variability and high ebullition events unrelated to tidal cycles are also commonly observed. Our data indicate that small‐scale processes beneath or at the sediment surface are responsible for the short‐term variability of the venting activity that is otherwise modulated by tides. Furthermore, a decrease of venting at one vent may coincide with an increase in plume activity at other vents. Our results depict a spatially and temporally dynamic seep environment, the variability of which cannot be fully characterized without systematic and comprehensive monitoring of the entire area. These results indicate that flux estimations may be largely overestimated or underestimated depending on the time, duration, and place of observation. Although sudden ebullition bursts are hardly predictable, we argue that tidal cycles must be taken into consideration when estimating gas fluxes.
Temperature‐Regulated Turnover of Chromophoric Dissolved Organic Matter in Global Dark Marginal Basins
Authors: Wang Chao , Guo Weidong , Li Yan , Dahlgren Randy A. , Guo Xianghui , Qu Liyin , Zhuang Wei 
Published: September 2021

AbstractOceanic absorption of heat generated by greenhouse gas emissions has resulted in warming of the dark ocean (>200 m) that contains a large refractory DOM (RDOM) pool. However, changes in microbially mediated production and degradation dynamics for RDOM components in response to warming of dark marginal basins remain unclear. Herein, we integrated data from the dark South China, Mediterranean and Japan Seas (temperature range: 0.09–15.1°C) to demonstrate that in situ production efficiency of two ubiquitous humic‐like fluorophores increased at higher dark ocean temperature, whereas chromophores at a wavelength of 325 nm (aCDOM(325)) changed from production to degradation at higher temperature. Increased oxygen consumption and a reduction of labile substrates in future warmer dark ocean environments may initiate the final degradation of some semi‐refractory components, thereby increasing the recalcitrance of RDOM, but decreasing the DOM inventory in dark basins and creating a positive feedback to rising atmospheric CO2.
Understanding Lead Times of Warm Water Volumes to ENSO Sea Surface Temperature Anomalies
Authors: Zhao Sen , Jin Fei‐Fei , Stuecker Malte F. 
Published: September 2021

AbstractThe equatorial Pacific warm water volume (WWV) and western equatorial Pacific WWV (WWVw) are two important long‐lead time El Niño‐Southern Oscillation (ENSO) event precursors. Here, we utilize the recharge‐discharge oscillator framework to obtain the analytical solution of WWV and WWVw lead times to ENSO sea surface temperatures (SSTs). Both WWV and WWVw lead times show a strong dependence on the inherent ENSO periodicity, whereas WWV lead time is further modulated by the air‐sea coupling strength and ENSO SST spatial pattern. The derived solution is able to explain observed decadal variations in lead times of WWV to SST in terms of variations in ENSO periodicity and air‐sea coupling strength.
Atmospheric Circulation Sensitivity to Changes in the Vertical Structure of Polar Warming
Authors: Kim Doyeon , Kang Sarah M. , Merlis Timothy M. , Shin Yechul 
Published: September 2021

AbstractThis study examines the effects of the vertical structure of polar warming on the remote atmospheric circulation. We apply thermal forcing at different vertical levels in the Northern Hemisphere polar region in two atmospheric global climate models of different complexity, both coupled to an aquaplanet slab ocean. The efficacy of polar heating in perturbing the remote climate increases with the altitude at which it is applied. This robust sensitivity arises from the dominance of surface temperature contribution to the outgoing longwave radiation owing to the large emissivity of the polar troposphere. An upper‐level polar heating has a smaller fraction of forcing balanced by radiative flux changes and a larger contribution from atmospheric energy transport changes, which provokes larger shifts in the extratropical jet and Hadley circulation. Our results suggest increasingly far‐reaching impacts of Arctic warming as a less surface‐trapped profile is projected for seasonally ice‐free conditions in the near future.
Coupled Impacts of Atmospheric Circulation and Sea‐Ice on Late Pleistocene Terrigenous Sediment Dynamics in the Subarctic Pacific Ocean
Authors: Zhong Yi , Liu Yanguang , Gong Xun , Wilson David J. , Lu Zhengyao , Liu Jiabo , Song Tengfei , Gorbarenko Sergey A. , Shi Xuefa , Yang Xiaoqiang , Liu Qingsong 
Published: September 2021

AbstractProcesses controlling environmental change in the subarctic Pacific Ocean on millennial to orbital timescales are not well understood. Here we use a 230‐kyr sedimentary record from the northwest Pacific Ocean to assess the response of late Pleistocene sediment dynamics to orbital forcing. Combining a source‐to‐sink perspective based on sedimentological records with climate model reanalysis, we reveal that fluctuations in sediment provenance were closely linked to obliquity‐forced changes in atmospheric circulation modes. Specifically, the position of the Aleutian Low controlled sediment transport from the Bering Sea and Aleutian Arc sources. Furthermore, a distinct shift in North Pacific ocean circulation during the Last Glacial Maximum may have been related to a strengthened Siberian High. The coincidence of atmospheric mode switches with changes in sea‐ice extent and North Pacific Intermediate Water formation in the marginal seas suggests that this coupled ocean‐atmosphere system may have acted as a regional amplifier of global climate variability.
The Response of Middle Thermosphere (∼160 km) Composition to the November 20 and 21, 2003 Superstorm
Authors: Yu Tingting , Wang Wenbin , Ren Zhipeng , Cai Xuguang , Yue Xinan , He Maosheng 
Published: September 2021

AbstractTIMED/GUVI limb measurements and first‐principles simulations from the Thermosphere Ionosphere Electrodynamics Global Circulation Model (TIEGCM) are used to investigate thermospheric atomic oxygen (O) and molecular nitrogen (N2) responses in the middle thermosphere on a constant pressure surface (∼160 km) to the November 20 and 21, 2003 superstorm. The consistency between GUVI observations and TIEGCM simulated composition changes allows us to utilize TIEGCM outputs to investigate the storm‐time behaviors of O and N2 systematically. Diagnostic analysis shows that horizontal and vertical advection are the two main processes that determine the storm‐induced perturbations in the middle thermosphere. Molecular diffusion has a relatively smaller magnitude than the two advection processes, acting to compensate for the changes caused by the transport partly. Contributions from chemistry and eddy diffusion are negligible. During the storm initial and main phases, composition variations at high latitudes are determined by both horizontal and vertical advection. At middle‐low latitudes, horizontal advection is the main driver for the composition changes where O mass mixing ratio decreases (N2 mass mixing ratio increases); whereas horizontal and vertical advection combined to dominate the changes in the regions where increases ( decreases). Over the entire storm period, horizontal advection plays a significant role in transporting high‐latitude composition perturbations globally. Our results also demonstrate that storm‐time temperature changes are not the direct cause of the composition perturbations on constant pressure surfaces.
Pore and Mineral Fabrics Control the Elastic Wave Velocities of Metapelite With Implications for Subduction Zone Tomography
Authors: Fliedner C. , French M. E. 
Published: September 2021

AbstractSeismic tomography is used to infer compositional variations and environmental conditions in active subduction zones. In some regions, low P‐wave and S‐wave velocities and high are documented near and along the plate boundary, and are interpreted to reflect high pore fluid pressures in metasedimentary rocks. However, there are limited experimental data with which to constrain the in‐situ wave speeds of metasedimentary rocks, particularly under elevated pore pressure. To determine whether the velocities of metasedimentary rocks are consistent with low wave speeds and high , we measured the ultrasonic velocities of the Orocopia schist, a greenschist facies metapelite, in the laboratory. Velocities were measured under dry and saturated conditions, at effective pressures between 1 and 136 MPa, parallel and normal to foliation, and at room temperature. We find that, under fluid‐saturated conditions, the velocities of the Orocopia schist and are consistent with anomalous values in subduction zones ( km/s, km/s, and ) at effective pressures less than 10 MPa and normal to foliation. We used differential effective medium models and microscopy to quantify the contributions of mineralogy, mineral fabric, porosity, and pore shape to , , and their anisotropies. We find that, although mineralogy and mineral anisotropy impart some control on the wave velocities, aligned, small aspect ratio pores (0.005–0.03) are required to explain the measured velocities and high . The low and and high in subduction zones can be explained by phyllosilicate‐rich metapelitic rocks under near‐lithostatic pore pressure.
Time Series of Near‐Inertial Gravity Wave Energy Fluxes: The Effect of a Strong Wind Event
Authors: Löb Jonas , Köhler Janna , Walter Maren , Mertens Christian , Rhein Monika 
Published: September 2021

AbstractLow mode internal waves in the stratified ocean are partially generated by the wind field in the near‐inertial range and important for interior mixing and for the oceanic energy pathways. Long‐term observations of energy fluxes of internal waves are sparse. Here, we study the temporal variability of wind‐generated low mode near‐inertial internal waves inside an internal tide beam emanating from seamounts south of the Azores. We use 20 months of consecutive mooring observations to calculate the mode 1 and mode 2 near‐inertial energy flux as well as the near‐inertial kinetic and potential energy. The energy flux time series is not steady due to its intermittent forcing with modes 1 and 2 contributing in a similar way to the total. A peak in the energy flux time series that can be directly linked to a storm event allows us to split the time series into a background period and a storm event period. The relative contribution of mode 1 to mode 2 remains the same during a storm event and background period. This study provides new insights into the relative importance of single wind events for the near‐inertial energy flux and the opportunity to quantify the impact of an isolated strong wind event compared to a calm, tide‐dominated background state. Thus, an adequate representation of storm events in parameterizations used for mixing estimates by ocean general circulation models is needed, as they are potentially of similar importance as the internal tides.
Methane Emissions Offset Net Carbon Dioxide Uptake From an Alpine Peatland on the Eastern Qinghai‐Tibetan Plateau
Authors: Peng Haijun , Chi Jinshu , Yao Hu , Guo Qian , Hong Bing , Ding Hanwei , Zhu Yongxuan , Wang Jie , Hong Yetang 
Published: September 2021

AbstractPeatlands store large amounts of carbon (C) and actively exchange greenhouse gases (GHGs) with the atmosphere, thus significantly affecting global C cycle and climate. Large uncertainty exists in C and GHG estimates of the alpine peatlands on Qinghai‐Tibetan Plateau (QTP), as direct measurements of CO2 and CH4 fluxes are scarce in this region. In this study, we provided 32‐month CO2 and CH4 fluxes measured using the eddy covariance (EC) technique in a typical alpine peatland on the eastern QTP to estimate the net C and CO2 equivalent (CO2‐eq) fluxes and investigate their environmental controls. Our results showed that the mean annual CO2 and CH4 fluxes were −68 ± 8 g CO2‐C m−2 yr−1 and 35 ± 0.3 g CH4‐C m−2 yr−1, respectively. While considering the traditional and sustained global warming potentials of CH4 over the 100‐year timescale, the peatland acted as a net CO2‐eq source (1,059 ± 30 and 1,853 ± 31 g CO2‐eq m−2 yr−1, respectively). The net CO2‐eq emissions during the non‐growing seasons contributed to over 40% of the annual CO2‐eq budgets. We further found that net CO2‐eq flux was primarily influenced by global radiation and soil temperature variations. This study was the first assessment to quantify the net CO2‐eq flux of the alpine peatland in the QTP region using EC measurements. Our study highlights that CH4 emissions from the alpine peatlands can largely offset the net cooling effect of CO2 uptake and future climate changes such as global warming might further enhance their potential warming effect.
Single-cell transcriptome analysis reveals cellular heterogeneity in the ascending aortas of normal and high-fat diet-fed mice
Authors: Kan Hao , Zhang Ka , Mao Aiqin , Geng Li , Gao Mengru , Feng Lei , You Qingjun , Ma Xin 
Published: September 2021

AbstractThe aorta contains numerous cell types that contribute to vascular inflammation and thus the progression of aortic diseases. However, the heterogeneity and cellular composition of the ascending aorta in the setting of a high-fat diet (HFD) have not been fully assessed. We performed single-cell RNA sequencing on ascending aortas from mice fed a normal diet and mice fed a HFD. Unsupervised cluster analysis of the transcriptional profiles from 24,001 aortic cells identified 27 clusters representing 10 cell types: endothelial cells (ECs), fibroblasts, vascular smooth muscle cells (SMCs), immune cells (B cells, T cells, macrophages, and dendritic cells), mesothelial cells, pericytes, and neural cells. After HFD intake, subpopulations of endothelial cells with lipid transport and angiogenesis capacity and extensive expression of contractile genes were defined. In the HFD group, three major SMC subpopulations showed increased expression of extracellular matrix-degradation genes, and a synthetic SMC subcluster was proportionally increased. This increase was accompanied by upregulation of proinflammatory genes. Under HFD conditions, aortic-resident macrophage numbers were increased, and blood-derived macrophages showed the strongest expression of proinflammatory cytokines. Our study elucidates the nature and range of the cellular composition of the ascending aorta and increases understanding of the development and progression of aortic inflammatory disease.
Bromodomain proteins: protectors against endogenous DNA damage and facilitators of genome integrity
Authors: Lee Seo Yun , Kim Jae Jin , Miller Kyle M. 
Published: September 2021

AbstractEndogenous DNA damage is a major contributor to mutations, which are drivers of cancer development. Bromodomain (BRD) proteins are well-established participants in chromatin-based DNA damage response (DDR) pathways, which maintain genome integrity from cell-intrinsic and extrinsic DNA-damaging sources. BRD proteins are most well-studied as regulators of transcription, but emerging evidence has revealed their importance in other DNA-templated processes, including DNA repair and replication. How BRD proteins mechanistically protect cells from endogenous DNA damage through their participation in these pathways remains an active area of investigation. Here, we review several recent studies establishing BRD proteins as key influencers of endogenous DNA damage, including DNA–RNA hybrid (R-loops) formation during transcription and participation in replication stress responses. As endogenous DNA damage is known to contribute to several human diseases, including neurodegeneration, immunodeficiencies, cancer, and aging, the ability of BRD proteins to suppress DNA damage and mutations is likely to provide new insights into the involvement of BRD proteins in these diseases. Although many studies have focused on BRD proteins in transcription, evidence indicates that BRD proteins have emergent functions in DNA repair and genome stability and are participants in the etiology and treatment of diseases involving endogenous DNA damage.