bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Method to Simulate the High‐Altitude Nuclear Electromagnetic Pulse Under the Asymmetrical Situation
Authors: Zhang Jin , Zhang Ye‐Rong 
Published: August 2020

AbstractThe zero‐order integral equation method (IEM) and the second‐order IEM were introduced to simulate the high‐altitude electromagnetic pulse (HEMP) in our former reports, where the planar gamma radiation model and the point gamma radiation model were utilized, respectively. Herein, the equation of the IEM is analyzed and simplified, after which the fifth‐order method is introduced. Several asymmetric gamma radiation patterns are employed to simulate the asymmetric environments. The results show that the fifth‐order method can well describe the tendency of the variation of the electric current source in the deposition region and that the HEMP radiating onto the ground not only depends on the electric current source along the line of sight (LOS) but also depends on the distribution of the electric current source around the LOS.
Evidence for an Active, Transcrustal Magma System in the Last 60 ka and Eruptive Degassing Budget (H2O, CO2, S, F, Cl, Br): The Case of Dominica
Authors: d'Augustin T. , Balcone‐Boissard H. , Boudon G. , Martel C. , Deloule E. , Bürckel P. 
Published: August 2020

AbstractThe Morne Trois Pitons‐Micotrin volcanic complex on the island of Dominica (Lesser Antilles) emitted a series of plinian eruptions between 18 and 9 ka BP. We studied it to constrain magma storage conditions and volatile degassing balances, by comparison with the three previous ignimbrites (~60–24 ka BP). Volatile concentrations in glass inclusions and mineral‐melt thermobarometry indicate storage at ≤200 MPa (~6–8 km) and 860–880°C. The magmas feeding these plinian eruptions were stored at a shallower depth than those that older ignimbrites from the same volcanic complex and stored at ~16 km. Close magma composition and similar halogen ratios, however, suggest a common source for the magmas feeding both the plinian eruptions and the ignimbrites. The large eruptive fluxes of F, Cl, and Br to the atmosphere (up to 1.4–2.8 × 10−1 Mt/km3, 1.5–4.0 Mt/km3, and 2–4 × 10−2 Mt/km3, respectively), estimated by the petrological method, support the potentially important role of volcanic halogens in modifying the chemistry of the atmosphere, though Cl is underestimated here because of buffering in a fluid phase. The behavior of S, potentially partitioned in the same fluid phase, prevents here the calculation of an eruptive outgassing budget.
Asthenospheric Flow of Plume Material Beneath Arabia Inferred From S Wave Traveltime Tomography
Authors: Lim Jung‐A , Chang Sung‐Joon , Mai P. Martin , Zahran Hani 
Published: August 2020

AbstractWidespread Cenozoic volcanism in the Arabian Peninsula has been attributed to mantle plume activity and/or lithospheric thinning due to rift‐related extension. However, there is discrepancy between geochemical and geophysical studies about which mechanism is dominant over the other for post‐12 Ma volcanism. Plume signals in some volcanic fields in the Arabian shield are not evident in isotope analyses, but low‐velocity anomalies connected to Afar are found beneath the Arabian shield in tomographic studies and interpreted as asthenospheric flow from the Afar plume. To resolve this contradiction, we investigate the upper mantle beneath the Arabian Peninsula and northeastern Africa by inverting relative S and SKS wave arrival times recorded at dense seismic networks to derive a high‐resolution S wave velocity model. Our results clearly show a narrow, elongated low‐velocity anomaly along the Makkah‐Madinah‐Nafud (MMN) volcanic line beneath the Arabian shield at 100–300 km depth which extends northward to Harrat Ithnayn and Harrat Lunayyir, but most likely not further north. The limited extent of the low‐velocity anomaly and variations in lithospheric thickness of the Arabian shield may explain why geochemical studies did not find plume signals in some harrats. Therefore, the timing and plume signals of volcanism in western Arabia may not be age progressive from Afar. We also find a possible connection between the low‐velocity anomalies beneath Harrat Lunayyir and the MMN line, suggesting that the 2007–2009 seismic swarm may be associated with northward asthenospheric flow of plume material from Afar.
Pathways and Water Mass Transformation Along and Across the Mohn‐Knipovich Ridge in the Nordic Seas
Authors: Ypma S. L. , Georgiou S. , Dugstad J. S. , Pietrzak J. D. , Katsman C. A. 
Published: August 2020

AbstractAtlantic Water takes various pathways through the Nordic Seas, and its transformation to denser waters forms a crucial connection to the lower limb of the Atlantic Meridional Overturning Circulation. Circulation maps often schematize two distinct pathways of Atlantic Water: one following the Norwegian Atlantic Slope Current along the continental slope of Norway and one following the Norwegian Atlantic Front Current along the Mohn and Knipovich Ridges. In this paper, the connectivity between the northward flow along these ridges is investigated. Analyzing trajectories of surface drifters and ARGO floats, we find that only 8% of the floats that travel near the mid‐ocean ridges take the frontal pathway to the north. Indeed, by tracing numerical particles in a realistic numerical simulation, part of the water mass traveling along the Mohn Ridge follows the 2,500 m isobath eastward and joins the slope current, instead of flowing north along the Knipovich Ridge. Furthermore, north of 74°N, frequent exchange between the slope current and the front current is observed. Therefore, the slope current and front current are less isolated than often schematized. Additionally, the observational data set reveals substantial cross‐ridge exchange; 31% of the floats that travel within 60 km from the mid‐ocean ridges cross it. Results from numerical simulations indicate that the cross‐ridge exchange leads to cooling and freshening of the Atlantic Water along the front. Deployments of floats near the mid‐ocean ridges are needed to investigate the pathway of Atlantic Water and its exchange across the ridge in more detail.
GLM and ABI Characteristics of Severe and Convective Storms
Authors: Thiel Kevin C. , Calhoun Kristin M. , Reinhart Anthony E. , MacGorman Donald R. 
Published: August 2020

AbstractThe recent deployment of the Geostationary Lightning Mapper (GLM) on board GOES‐16 and GOES‐17 provides a new perspective of total lightning production for the severe convective storms research and operational communities. While the GLM has met its performance targets, further understanding flash characteristics and the physical limitations of the GLM are required to increase the applicability of the data. Derived cloud‐top height and infrared (IR) brightness temperature products from the Advanced Baseline Imager (ABI) are used to assess data quality and characteristics from gridded GLM imagery across 7 weeks of active severe weather: 13 April through 31 May 2019. Areas with cloud tops colder than 240 K typically produced lightning, though this becomes less certain near the edge of the field of view due to algorithm limitations. Increasing flash rates were observed to correlate with decreasing flash areas, increasing cloud‐top heights, and colder cloud‐top temperatures. However, flash rates and size were more strongly tied to convective intensity and proximity to convective hazards at the surface due to the ability to delineate between convective and stratiform precipitation. Results show that merging ABI and GLM data sets could add value to both machine learning and statistical‐based algorithms and also forecast applications with each providing unique details, although parameters such as GOES‐16 viewing angle should be considered. Lastly, two case studies (24 and 27 May 2019) are used to help interpret the results from the 7‐week sampling period and identify GLM and ABI trends related to thunderstorm evolution.
Sensitivity of Analytical Flux Footprint Models in Diverse Source‐Receptor Configurations: A Field Experimental Study
Authors: Kumari Shweta , Kambhammettu B. V. N. P. , Niyogi Dev 
Published: August 2020

AbstractFlux footprint models simulate the source area of scalar fluxes from a measurement site but are hindered by the assumptions that are rarely satisfied in real field conditions. We conducted artificial tracer (CO2) experiments in unstable conditions over an open field, to evaluate three analytical footprint models (Kormann and Meixner‐KM, Hsieh‐HS, and Schuepp‐SP) under variable source‐receptor settings. Experimental configurations include (i) source length (point to semi‐infinite), (ii) emission height (below and above zero‐plane displacement), (iii) measurement height (1.5 and 2.8 m above ground level), and (iv) offset from the principal wind direction (±60°). Eddy covariance (EC) fluxes were measured using one source‐multiple sampling system approach. Results indicate that KM model is in good agreement with the EC measurements under ideal conditions (R2 = 0.81, root‐mean‐square error (RMSE) = 0.008 m−1) compared to HS (R2 = 0.60, RMSE = 0.014 m−1) and SP (R2 = 0.72, RMSE = 0.009 m−1) models. The KM model captured both footprint maximum and its location. Uncertainties in the model estimates were ascertained by considering random ensembles of wind speed, friction velocity, and Obukhov length. The KM model has resulted in the least uncertainty band containing all the flux observations. Error propagation into model simulations resulting from a progressive deviation of the underlying assumptions was assessed. Model‐to‐measurement discrepancies were positive (flux overestimation) for offset deviations up to ±30° and negative beyond. Modeled fluxes were sensitive to source length and emission height in comparison to the offset deviation. Overall, the KM model showed the least error (9.6 ± 8.12%) for different source‐receptor deviations. Study findings can help in evaluating and improving the analytical models for use under nonideal source‐receptor configurations and scaling measurements for different applications.
Analysis of the human breast milk microbiome and bacterial extracellular vesicles in healthy mothers
Authors: Kim Su Yeong , Yi Dae Yong 
Published: August 2020

AbstractThe microbiota of human breast milk (HBM) contribute to infant gut colonization; however, whether bacterial extracellular vesicles (EVs) are present in HBM or might contribute to this process remains unknown. In this study, we characterized the HBM microbiota of healthy Korean mothers and measured the key bacteria likely affecting infant gut colonization by analyzing both the microbiota and bacterial EVs. A total of 22 HBM samples were collected from lactating mothers. The DNA of bacteria and bacteria-derived EVs was extracted from each sample. In alpha-diversity analyses, bacterial samples showed higher richness and evenness than bacterial EV samples, and beta-diversity analyses showed significant differences between bacteria and bacterial EVs within identical individual samples. Firmicutes accounted for the largest proportion among the phyla, followed by Proteobacteria, Bacteroidetes, and Actinobacteria, in both bacteria and bacterial EV samples. At the genus level,Streptococcus(25.1%) andStaphylococcus(10.7%) were predominant in bacterial samples, whereasBacteroides(9.1%),Acinetobacter(6.9%), andLactobacillaceae(f)(5.5%) were prevalent in bacterial EV samples. Several genera, includingBifidobacterium, were significantly positively correlated between the two samples. This study revealed the diverse bacterial communities in the HBM of healthy lactating mothers, and found that gut-associated genera accounted for a high proportion in bacterial EV samples. Our findings suggest the existence of key bacteria with metabolic activity that are independent of the major bacterial populations that inhabit HBM, and the possibility that EVs derived from these bacteria are involved in the vertical transfer of gut microbiota.
Volumetric changes in subcortical structures following repeated ketamine treatment in patients with major depressive disorder: a longitudinal analysis
Authors: Zhou Yan-Ling , Wu Feng-Chun , Liu Wei-Jian , Zheng Wei , Wang Cheng-Yu , Zhan Yan-Ni , Lan Xiao-Feng , Ning Yu-Ping 
Published: August 2020

AbstractAbnormal subcortical structures have been associated with major depressive disorder (MDD) and could be reversed by antidepressant treatment. To date no study has examined the relationship between subcortical volumes and repeated ketamine treatment. The current study investigated volume changes in specific subcortical structures and hippocampal subfields after six ketamine infusions. Forty-four patients with MDD received six subanesthetic dose infusions of ketamine. Depressive symptoms were assessed and magnetic resonance imaging scans were performed before and after six ketamine infusions. FreeSurfer software was used to process the T1 images and analyze the volumes of the subcortical regions and hippocampal subfields. After six ketamine infusions, increases were observed in the volumes of the left amygdala; the right hippocampus; the cornu ammonis 4 body, granule cell and molecular layer of the dentate gyrus body in the left hippocampus; and the cornu ammonis 4 head and molecular layer head in the right hippocampus. Positive correlations were found between symptom improvement and the pretreatment volumes of the right thalamus (r = 0.501; P = 0.001) and left subiculum head of the hippocampus (r = 0.471; P = 0.002), and changes in the volumes of the left amygdala (r = −0.452; P = 0.003) and the left cornu ammonis 4 body (r = −0.537; P < 0.001). Our findings provided evidence for critical roles of the amygdala and specific hippocampal subfields in the antidepressant effect of repeated ketamine treatment. Relatively larger volumes in right thalamus and left subiculum head in the hippocampus can predict a superior clinical outcome of ketamine treatment in MDD patients.
Neuroinflammation in dementia with Lewy bodies: a human post-mortem study
Authors: Amin Jay , Holmes Clive , Dorey Robert B. , Tommasino Emanuele , Casal Yuri R. , Williams Daisy M. , Dupuy Charles , Nicoll James A. R. , Boche Delphine 
Published: August 2020

AbstractDementia with Lewy bodies (DLB) is the second most common neurodegenerative cause of dementia, behind Alzheimer’s disease (AD). It is now established that cerebral inflammation has a key role in the aetiology and progression of AD, but this has yet to be confirmed in DLB. We aimed to determine the neuroinflammatory profile in the cerebral cortex of a large cohort of DLB cases. Thirty post-mortem confirmed DLB cases and twenty-nine matched controls were immunolabelled (Brodmann area 21) and quantified for: neuropathology—αSYN, Aβ, P-tau; microglial phenotype—Iba1, HLA-DR, CD68, FcƴR (CD64, CD32a, CD32b, CD16); presence of T lymphocytes—CD3; and anti-inflammatory markers—IL4R, CHI3L1. Status spongiosis, as a marker of neuropil degeneration, was quantified using Haematoxylin and Eosin staining. We found no significant difference between groups in protein load for Iba1, HLA-DR, CD68, CD64, CD32b, IL4R, or CHI3L1, despite increased neuropathology in DLB. CD32a load was significantly lower, and CD16 load higher, in DLB compared with controls. There was no difference in status spongiosis between groups. Significantly more DLB cases than controls showed T-lymphocyte recruitment. Overall, we conclude that microglial activation is not a prominent feature of DLB, and that this may be associated with the relatively modest neuropil degeneration observed in DLB. Our findings, based on the largest post-mortem cohort to date exploring neuroinflammation in DLB, demonstrate a dissociation between protein deposition, neurodegeneration and microglial activation. The relative preservation of cortical structures in DLB suggests the dementia could be more amenable to potential therapies.
Preclinical support for the therapeutic potential of zolmitriptan as a treatment for cocaine use disorders
Authors: Garcia Raul , Le Tien , Scott Samantha N. , Charmchi Delaram , Sprout Jamie M.L. , Pentkowski Nathan S. , Neisewander Janet L. 
Published: August 2020

AbstractSerotonin 1B receptor (5-HT1BR) agonists enhance cocaine intake in rats during daily self-administration but attenuate cocaine intake after prolonged abstinence. Here we investigated whether the less selective but clinically available 5-HT1D/1BR agonist, zolmitriptan, produces similar effects. Male and free-cycling female Sprague-Dawley rats were trained to lever press for cocaine (0.75 mg/kg, i.v.) or sucrose (45 mg pellet) reinforcement until performance rates stabilized. Rats then received zolmitriptan (3.0, 5.6, and 10 mg/kg, s.c.) prior to testing for its effects on response and reinforcement rates. Under cocaine testing conditions, rats had access to the training dose for the first hour followed by a lower cocaine dose (0.075 mg/kg, i.v.) for the second hour. Zolmitriptan decreased cocaine intake at both cocaine doses and in both sexes even without a period of abstinence and without altering sucrose intake. A separate group of rats underwent identical training procedures and were tested for effects of the selective 5-HT1Band 5-HT1Dreceptor antagonists, SB224289 (3.2, 5.6, and 10 mg/kg, s.c.) and BRL15572 (0.3, 1.0, and 3.0 mg/kg, i.p.), respectively, alone or in combination with zolmitriptan (5.6 mg/kg, s.c.) under identical cocaine testing procedures as above. The zolmitriptan-induced decrease in cocaine intake was reversed by SB224289 and to a lesser extent by BRL15572, suggesting that the effects of zolmitriptan involve both 5-HT1Band 5-HT1Dreceptors. Neither zolmitriptan, SB224289, or BRL15572 altered locomotor activity at the doses effective for modulating cocaine intake. These findings suggest that zolmitriptan has potential for repurposing as a treatment for cocaine use disorders.
PSGL-1 inhibits HIV-1 infection by restricting actin dynamics and sequestering HIV envelope proteins
Authors: Liu Ying , Song Yutong , Zhang Siyu , Diao Min , Huang Shanjin , Li Sai , Tan Xu 
Published: August 2020

AbstractPSGL-1 has recently been identified as an HIV restriction factor that inhibits HIV DNA synthesis and more potently, virion infectivity. But the underlying mechanisms of these inhibitions are unknown. Here we show that PSGL-1 directly binds to cellular actin filaments (F-actin) to restrict actin dynamics, which leads to inhibition of HIV DNA synthesis. PSGL-1 is incorporated into nascent virions and restricts actin dynamics in the virions, which partially accounts for the inhibition of virion infectivity. More potently, PSGL-1 inhibits incorporation of Env proteins into nascent virions, causing a loss of envelope spikes on the virions as shown by Cryo-electron microscopy and super-resolution imaging. This loss is associated with a profound defect in viral entry. Mechanistically, PSGL-1 binds gp41 and sequesters gp41 at the plasma membrane, explaining the inhibition of Env incorporation in nascent virions. PSGL-1’s dual anti-HIV mechanisms represent novel strategies of human cells to defend against HIV infection.
An optimal posttreatment surveillance strategy for cancer survivors based on an individualized risk-based approach
Authors: Zhou Guan-Qun , Wu Chen-Fei , Deng Bin , Gao Tian-Sheng , Lv Jia-Wei , Lin Li , Chen Fo-ping , Kou Jia , Zhang Zhao-Xi , Huang Xiao-Dan , Zheng Zi-Qi , Ma Jun , Liang Jin-Hui , Sun Ying 
Published: August 2020

AbstractThe optimal post-treatment surveillance strategy that can detect early recurrence of a cancer within limited visits remains unexplored. Here we adopt nasopharyngeal carcinoma as the study model to establish an approach to surveillance that balances the effectiveness of disease detection versus costs. A total of 7,043 newly-diagnosed patients are grouped according to a clinic-molecular risk grouping system. We use a random survival forest model to simulate the monthly probability of disease recurrence, and thereby establish risk-based surveillance arrangements that can maximize the efficacy of recurrence detection per visit. Markov decision-analytic models further validate that the risk-based surveillance outperforms the control strategies and is the most cost-effective. These results are confirmed in an external validation cohort. Finally, we recommend the risk-based surveillance arrangement which requires 10, 11, 13 and 14 visits for group I to IV. Our surveillance strategies might pave the way for individualized and economic surveillance for cancer survivors.
A systematic comparison of pharmacogene star allele calling bioinformatics algorithms: a focus on CYP2D6 genotyping
Authors: Twesigomwe David , Wright Galen E. B. , Drögemöller Britt I. , da Rocha Jorge , Lombard Zané , Hazelhurst Scott 
Published: August 2020

AbstractGenetic variation in genes encoding cytochrome P450 enzymes has important clinical implications for drug metabolism. Bioinformatics algorithms for genotyping these highly polymorphic genes using high-throughput sequence data and automating phenotype prediction have recently been developed. The CYP2D6 gene is often used as a model during the validation of these algorithms due to its clinical importance, high polymorphism, and structural variations. However, the validation process is often limited to common star alleles due to scarcity of reference datasets. In addition, there has been no comprehensive benchmark of these algorithms to date. We performed a systematic comparison of three star allele calling algorithms using 4618 simulations as well as 75 whole-genome sequence samples from the GeT-RM project. Overall, we found that Aldy and Astrolabe are better suited to call both common and rare diplotypes compared to Stargazer, which is affected by population structure. Aldy was the best performing algorithm in calling CYP2D6 structural variants followed by Stargazer, whereas Astrolabe had limitations especially in calling hybrid rearrangements. We found that ensemble genotyping, characterised by taking a consensus of genotypes called by all three algorithms, has higher haplotype concordance but it is prone to ambiguities whenever complete discrepancies between the tools arise. Further, we evaluated the effects of sequencing coverage and indel misalignment on genotyping accuracy. Our account of the strengths and limitations of these algorithms is extremely important to clinicians and researchers in the pharmacogenomics and precision medicine communities looking to haplotype CYP2D6 and other pharmacogenes using high-throughput sequencing data.