bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal Variation of the D‐Region Ionosphere: Very Low Frequency (VLF) and Machine Learning Models
Authors: Richardson David K. , Cohen Morris B. 
Published: September 2021

AbstractThe D‐region ionosphere (6090 km) plays an important role in long‐range communication and response to solar and space weather; however, it is difficult to directly measure with currently available technology. Very low frequency (VLF) radio remote sensing is one of the more promising approaches, using the efficient reflection of VLF waves from the D‐region. A number of VLF beacons can therefore be turned into diagnostic tools. VLF remote sensing techniques are useful and can provide global coverage, but in practice have been applied to a limited area and often on only a small number of days. In this work, we expand the use of a recently introduced machine learning based approach (Gross & Cohen, 2020, https://doi.org/10.1029/2019JA027135) to observe and model the D‐region electron density using VLF transmitting beacons and receivers. We have extended the model to cover nighttime in addition to daytime, and have applied it to track D‐region waveguide parameters, h’ and , over 400 daytimes and 150 nighttimes on up to 21 transmitter‐receiver paths across the continental US. Using an exponential fit, h’ represents the height of the ionosphere and represents the slope of the electron density. Using this data set, we quantify diurnal, daily and seasonal variations of the D‐region ionosphere for both daytime and nighttime D‐region ionosphere. We show that our model identifies expected variations, as well as producing results in line with other previous studies. Additionally, we show that our daytime predictions exhibit a larger autocorrelation at higher time lags than our nighttime predictions, indicating a model with persistence may perform better.
Zircon Solubility in Solute‐Rich Supercritical Fluids and Zr Transfer From Slab to Wedge in the Deep Subduction Process
Authors: Chen Wei , Xiong Xiaolin , Takahashi Eiichi 
Published: September 2021

AbstractZircon solubility in aqueous fluids, hydrous melts, and supercritical fluids is important for understanding the high field strength elements (HFSEs) chemical transport in subduction zones. Although zircon solubility was extensively studied in aqueous fluids and hydrous silicate melts, its solubility in solute‐rich fluids or supercritical fluids is poorly known. Here, we experimentally determined zircon solubility in KAlSi3O8 (±K2O ± Al2O3) – H2O supercritical fluids at 2.0–6.0 GPa and 800°C–1000°C, close to the slab‐top conditions at sub‐arc depths. The results show that zircon solubility (expressed as ZrO2 content at zircon saturation) ranges from 65 to 6,400 ppm ZrO2, 10–100 times higher than that in dilute aqueous fluids; it increases with temperature, solute content, and solute alkalinity (molar K/Al ratio) but decreases with pressure. The experiments at 2.0 GPa show that solute alkalinity in addition to temperature and solute content exerts a primary control on zircon solubility, while the experiments at 4.0–6.0 GPa show that the negative effect of pressure on zircon solubility is offset by the increase in solute alkalinity due to the crystallization of Al‐rich phases kyanite and muscovite. We suggest that high‐alkali supercritical fluids during deep subduction could be significant transfer agents for Zr from slab to mantle wedge.
Late Oligocene–Early Miocene Detachment Faulting in Crystalline Basement, Mecca Hills, CA, Documented With Zircon (U–Th)/He Date‐eU‐Visual Radiation Damage Patterns
Authors: Moser A. C. , Ault A. K. , Stearns M. A. , Evans J. P. , Guenthner W. R. 
Published: September 2021

AbstractZircon (U–Th)/He (zircon He) thermochronometry and visual radiation damage relationships reveal the timing and patterns of Orocopia Schist and North American basement exhumation in the Mecca Hills, CA. Zircon crystals from these units were selected to maximize the spectrum in visual metamictization and effective U (eU) concentrations, and thus He retentivity, in each sample. Zircon He dates (n = 31 analyses) from six of seven samples are ∼24 Ma regardless of eU, despite a large spread in eU (>2,800 ppm) across all grains. One sample (n = 7 analyses) yields a mean ∼65 Ma date. Uniform zircon He dates over a range of eU concentrations and their preserved visual metamictization indicate these grains experienced a thermal history that induced complete He loss, but did not anneal the damage. This is consistent with recent work that indicates zircon radiation damage anneals at higher temperatures than parameterized in current damage annealing models. The zircon He data patterns, together with new zircon U‐Pb results and thermal history modeling, reveal the two basement units in the Mecca Hills exhumed simultaneously at ∼24 Ma, likely by the Orocopia Mountains detachment fault. This requires both basement units lie in the footwall of the detachment, and implies the breakaway zone of the Orocopia Mountains detachment fault was west of the present‐day Mecca Hills basement exposures and has been translated by the San Andreas fault. Combined with prior work, our data suggest large‐magnitude late Oligocene–early Miocene extension in the southwestern Cordillera was more widespread than previously recognized.
Polycythemia vera: historical oversights, diagnostic details, and therapeutic views
Authors: Tefferi Ayalew , Vannucchi Alessandro M. , Barbui Tiziano 
Published: September 2021

AbstractPolycythemia vera (PV) is a relatively indolent myeloid neoplasm with median survival that exceeds 35 years in young patients, but its natural history might be interrupted by thrombotic, fibrotic, or leukemic events, with respective 20-year rates of 26%, 16%, and 4%. Current treatment strategies in PV have not been shown to prolong survival or lessen the risk of leukemic or fibrotic progression and instead are directed at preventing thrombotic complications. In the latter regard, two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). All patients require phlebotomy to keep hematocrit below 45% and once-daily low-dose aspirin, in the absence of contraindications. Cytoreductive therapy is recommended for high-risk or symptomatic low-risk disease; our first-line drug of choice in this regard is hydroxyurea but we consider pegylated interferon as an alternative in certain situations, including in young women of reproductive age, in patients manifesting intolerance or resistance to hydroxyurea therapy, and in situations where treatment is indicated for curbing phlebotomy requirement rather than preventing thrombosis. Additional treatment options include busulfan and ruxolitinib; the former is preferred in older patients and the latter in the presence of symptoms reminiscent of post-PV myelofibrosis or protracted pruritus. Our drug choices reflect our appreciation for long-term track record of safety, evidence for reduction of thrombosis risk, and broader suppression of myeloproliferation. Controlled studies are needed to clarify the added value of twice- vs once-daily aspirin dosing and direct oral anticoagulants. In this invited review, we discuss our current approach to diagnosis, prognostication, and treatment of PV in general, as well as during specific situations, including pregnancy and splanchnic vein thrombosis.
Highly diverse flavobacterial phages isolated from North Sea spring blooms
Authors: Bartlau Nina , Wichels Antje , Krohne Georg , Adriaenssens Evelien M , Heins Anneke , Fuchs Bernhard M , Amann Rudolf , Moraru Cristina 
Published: September 2021

Abstract
It is generally recognized that phages are a mortality factor for their bacterial hosts. This could be particularly true in spring phytoplankton blooms, which are known to be closely followed by a highly specialized bacterial community. We hypothesized that phages modulate these dense heterotrophic bacteria successions following phytoplankton blooms. In this study, we focused on Flavobacteriia, because they are main responders during these blooms and have an important role in the degradation of polysaccharides. A cultivation-based approach was used, obtaining 44 lytic flavobacterial phages (flavophages), representing twelve new species from two viral realms. Taxonomic analysis allowed us to delineate ten new phage genera and ten new families, from which nine and four, respectively, had no previously cultivated representatives. Genomic analysis predicted various life styles and genomic replication strategies. A likely eukaryote-associated host habitat was reflected in the gene content of some of the flavophages. Detection in cellular metagenomes and by direct-plating showed that part of these phages were actively replicating in the environment during the 2018 spring bloom. Furthermore, CRISPR/Cas spacers and re-isolation during two consecutive years suggested that, at least part of the new flavophages are stable components of the microbial community in the North Sea. Together, our results indicate that these diverse flavophages have the potential to modulate their respective host populations.
RETRACTED ARTICLE: Expansion of monocytic myeloid-derived suppressor cells ameliorated intestinal inflammatory response by radiation through SOCS3 expression
Authors: Choi You Yeon , Seong Ki Moon , Lee Hyun Jung , Lee Seung Sook , Kim Areumnuri 
Published: September 2021

AbstractRadiation-induced colitis is a common clinical problem after radiation therapy and accidental radiation exposure. Myeloid-derived suppressor cells (MDSCs) have immunosuppressive functions that use a variety of mechanisms to alter both the innate and the adaptive immune systems. Here, we demonstrated that radiation exposure in mice promoted the expansion of splenic and intestinal MDSCs and caused intestinal inflammation due to the increased secretion of cytokines. Depletion of monocytic MDSCs using anti-Ly6C exacerbated radiation-induced colitis and altered the expression of inflammatory cytokine IL10. Adoptive transfers of 0.5 Gy-derived MDSCs ameliorated this radiation-induced colitis through the production IL10 and activation of both STAT3 and SOCS3 signaling. Intestinal-inflammation recovery using 0.5 Gy-induced MDSCs was assessed using histological grading of colitis, colon length, body weight, and survival rate. Using in vitro co-cultures, we found that 0.5 Gy-induced MDSCs had higher expression levels of IL10 and SOCS3 compared with 5 Gy-induced MDSCs. In addition, IL10 expression was not enhanced in SOCS3-depleted cells, even in the presence of 0.5 Gy-induced monocytic MDSCs. Collectively, the results indicate that 0.5 Gy-induced MDSCs play an important immunoregulatory role in this radiation-induced colitis mouse model by releasing anti-inflammatory cytokines and suggest that IL10-overexpressing mMDSCs may be potential immune-therapy targets for treating colitis.
Aggravated stress fluctuation and mechanical size effects of nanoscale lamellar bone pillars
Authors: Ma Zhichao , Qiang Zhenfeng , Guo Chaowei , Jiang Yue , Zhao Hongwei , Wen Cuie , Ren Luquan 
Published: September 2021

AbstractThe size effects of mechanical properties influence the microdeformation behaviors and failure mechanisms of hierarchical lamellar bones. Investigations of the continuous deformation behaviors and structure–behavior–property relationships of nanoscale lamellar bones provide essential data for reducing the risk of fracture. Here, five pillars with diameters ranging from 640 to 4971 nm inside a single lamella were fabricated. In situ pillar compressive tests inside a scanning electron microscope directly revealed the diameter-dependent enhanced strength, ductility, and stress fluctuation amplitude. Real-time observations also revealed the segmented deformation and morphological anisotropy of pillars with smaller diameters and the slight elastic recovery of pillars with larger diameters. The critical diameter leading to the brittle-to-ductile transition was confirmed. The “analogous to serrated flow” stress fluctuation behaviors at the nanoscale exhibited a significant size effect, with coincident fluctuation cycles independent of diameter, and each cycle of the fluctuation manifested as a slow stress increase and a rapid stress release. The discontinuous fracture of collagen fibrils, embedded enhancement of hydroxyapatite crystals, and layered dislocation movement on the basis of strain gradient plasticity theory were expected to induce cyclical stress fluctuations with different amplitudes.
In vivo non-invasive near-infrared spectroscopy distinguishes normal, post-stroke, and botulinum toxin treated human muscles
Authors: Currà Antonio , Gasbarrone Riccardo , Cardillo Alessandra , Fattapposta Francesco , Missori Paolo , Marinelli Lucio , Bonifazi Giuseppe , Serranti Silvia , Trompetto Carlo 
Published: September 2021

AbstractIn post-stroke hemiparesis, neural impairment alters muscle control, causing abnormal movement and posture in the affected limbs. A decrease in voluntary use of the paretic arm and flexed posture during rest also induce secondary tissue transformation in the upper limb muscles. To obtain a specific, accurate, and reproducible marker of the current biological status of muscles, we collected visible (VIS) and short-wave Infrared (SWIR) reflectance spectra in vivo using a portable spectroradiometer (350–2500 nm), which provided the spectral fingerprints of the elbow flexors and extensors. We compared the spectra for the affected and unaffected sides in 23 patients with post-stroke hemiparesis (25–87 years, 8 women) and eight healthy controls (33–87 years, 5 women). In eight patients, spectra were collected before and after botulinum toxin injection. Spectra underwent off-line preprocessing, principal component analysis, and partial least-squares discriminant analysis. Spectral fingerprints discriminated the muscle (biceps vs. triceps), neurological condition (normal vs. affected vs. unaffected), and effect of botulinum toxin treatment (before vs. 30 to 40 days vs. 110 to 120 days after injection). VIS-SWIR spectroscopy proved valuable for non-invasive assessment of optical properties in muscles, enabled more comprehensive evaluation of hemiparetic muscles, and provided optimal monitoring of the effectiveness of medication.
Changes in plasma C1q, apelin and adropin concentrations in older adults after descending and ascending stair walking intervention
Authors: Chen Trevor C. , Huang Tsang-Hai , Tseng Wei-Chin , Tseng Kuo-Wei , Hsieh Chung-Chan , Chen Mei-Yen , Chou Tai-Ying , Huang Yuh-Chuan , Chen Hsin-Lian , Nosaka Kazunori 
Published: September 2021

AbstractThis study compared changes in plasma complement component 1q (C1q), apelin and adropin concentrations in older obese women after descending (DSW) and ascending stair walking (ASW) training (n = 15/group) performed twice a week for 12 weeks, with gradual increases in exercise time from 5 to 60 min. Fasting blood samples were collected 3 days before the first and 4 days after the last training session. The improvements in the maximal voluntary isometric contraction (MVIC) strength of the knee extensors, functional physical fitness [e.g., 30-s chair stand (CS) performance], resting systolic blood pressure (SBP), insulin sensitivity [e.g., oral glucose tolerance test (OGTT)] and blood lipid profiles [e.g., total cholesterol (TC)] were greater (p < 0.05) in the DSW than ASW group. Plasma C1q decreased (− 51 ± 30%), and apelin (23 ± 15%) and adropin (127 ± 106%) increased (p ≤ .0.05) only after DSW. Significant (p ≤  0.01) partial correlations were found between the pre- to post-DSW changes in C1q, apelin or adropin and changes in outcome measures [e.g., C1q and MVIC (r = − 0.837), apelin and SBP (r = − 0.854), and andropin and OGTT (r = − 0.729)]. These results showed that greater decreases in plasma C1q and greater increases in apelin and adropin concentrations were associated with greater improvements in outcome measures after DSW than after ASW.
Optical coherence tomography angiography (OCTA) of retinal vasculature in patients with post fever retinitis: a qualitative and quantitative analysis
Authors: Sanjay Srinivasan , Gadde Santosh Gopi Krishna , Agrawal Sameeksha , Mahendradas Padmamalini , Govindaswamy Nivedhitha , Kawali Ankush , Jayadev Chaitra , Sangai Sajjan , Roy Abhijit Sinha , Shetty Rohit 
Published: September 2021

AbstractPost fever retinitis is a heterogenous entity that is seen 2–4 weeks after a systemic febrile illness in an immunocompetent individual. It may occur following bacterial, viruses, or protozoal infection. Optical coherence angiography (OCTA) is a newer non-invasive modality that is an alternative to fundus fluorescein angiography to image the retinal microvasculature. We hereby describe the vascular changes during the acute phase of post fever retinitis on OCTA. Imaging on OCTA was done for all patients with post fever retinitis at presentation with 3 × 3 mm and 8 × 8 mm scans centred on the macula and corresponding enface optical coherence tomography (OCT) scans obtained. A qualitative and quantitative analysis was done for all images. 46 eyes of 33 patients were included in the study. Salient features noted were changes in the superficial (SCP) and deep capillary plexus (DCP) with capillary rarefaction and irregularity of larger vessels in the SCP. The DCP had more capillary rarefaction when compared to the SCP. The foveal avascular zone (FAZ) was altered with an irregular perifoveal network. Our series of post fever retinitis describes the salient vascular features on OCTA. Although the presumed aetiology was different in all our patients, they developed similar changes on OCTA. While OCTA is not useful if there is gross macular oedema, the altered FAZ can be indicative of macular ischemia.
Camera realignment imposes a cost on laparoscopic performance
Authors: Hewitson Christopher L. , Shukur Sinan T. , Cartmill John , Crossley Matthew J. , Kaplan David M. 
Published: September 2021

AbstractThere is an unresolved question about whether realigned visual feedback is beneficial or costly to laparoscopic task performance. We provide evidence that camera realignment imposes a reliable cost on performance across both naive controls and experienced surgeons. This finding clarifies an important ongoing discussion in the literature about the effects of camera realignment, which could inform the strategies that laparoscopic surgeons use in the operating room.
Parasites and diet as main drivers of the Malagasy gut microbiome richness and function
Authors: Mondot Stanislas , Poirier Philippe , Abou-Bacar Ahmed , Greigert Valentin , Brunet Julie , Nourrisson Céline , Randrianarivelojosia Milijaona , Razafindrakoto Jean-Louis , Morel Eugene , Rakotomalala Rivo S. , Leclerc Marion , Le Roux Karine , Monot Céline , Lepage Patricia , Candolfi Ermanno 
Published: September 2021

AbstractInteractions between the prokaryotic microbiome and eukaryotic parasites in the vertebrate gut may affect overall host health and disease. While intertropical areas exhibit a high rate of parasites carriers, such interactions are understudied in these populations. Our objectives were to (1) describe the gut microbiome of individuals living in Madagascar, (2) identify potential associations between bacterial taxa and parasites colonizing the digestive tract and (3) highlight main determinants of the gut microbiota composition in this developing country. Metadata (socioeconomic, diet, clinical) and fecal samples were collected from 219 volunteers from North-West Madagascar (Mahajanga). Fecal microbiome was assessed through 16S rRNA gene sequencing and metabolomics, and related to dietary habits and parasites carriage. We highlight important Malagasy gut microbiome peculiarities. Out of three detected enterotypes, only one is similar to that observed in Westernized countries (Ruminococcus-driven). Functions associated with the two others (Clostridium sensu stricto-driven and Escherichia/Shigella-driven) are mostly directed toward amino acids biosynthesis and degradation, respectively. Diet and protozoan carriage were the main drivers of microbiota composition. High protozoan carriage was associated with higher diversity, richness and microbial functionalities. The gut microbiome of Malagasy strongly differs from that of Westernized countries. Asymptomatic protozoan carriage and dietary habits are the external factors with the deepest impact on gut microbiome. Further studies are needed to understand whether gut microbial richness constitute a predilection niche for protozoans colonization, due to their gazing features, or whether the parasites themselves induce a higher bacterial richness.
A Bayesian approach for accurate de novo transcriptome assembly
Authors: Shi Xu , Wang Xiao , Neuwald Andrew F. , Halakivi-Clarke Leena , Clarke Robert , Xuan Jianhua 
Published: September 2021

AbstractDe novo transcriptome assembly from billions of RNA-seq reads is very challenging due to alternative splicing and various levels of expression, which often leads to incorrect, mis-assembled transcripts. BayesDenovo addresses this problem by using both a read-guided strategy to accurately reconstruct splicing graphs from the RNA-seq data and a Bayesian strategy to estimate, from these graphs, the probability of transcript expression without penalizing poorly expressed transcripts. Simulation and cell line benchmark studies demonstrate that BayesDenovo is very effective in reducing false positives and achieves much higher accuracy than other assemblers, especially for alternatively spliced genes and for highly or poorly expressed transcripts. Moreover, BayesDenovo is more robust on multiple replicates by assembling a larger portion of common transcripts. When applied to breast cancer data, BayesDenovo identifies phenotype-specific transcripts associated with breast cancer recurrence.
Longitudinal changes in physical activity during and after the first national lockdown due to the COVID-19 pandemic in England
Authors: Bu Feifei , Bone Jessica K. , Mitchell John J. , Steptoe Andrew , Fancourt Daisy 
Published: September 2021

AbstractRecent studies have shown reduced physical activity at early stages of the COVID-19 pandemic. However, there is a lack of investigation on longitudinal changes in physical activity beyond lockdowns and stay-at-home orders. Moreover, it is unclear if there is heterogeneity in physical activity growth trajectories. This study aimed to explore longitudinal patterns of physical activity and factors associated with them. Data were from the UCL COVID-19 Social Study. The analytical sample consisted of 35,915 adults in England who were followed up for 22 weeks from 24th March to 23rd August 2020. Data were analysed using growth mixture models. Our analyses identified six classes of growth trajectories, including three stable classes showing little change over time (62.4% in total), two classes showing decreasing physical activity (28.6%), and one class showing increasing physical activity over time (9%). A range of factors were found to be associated the class membership of physical activity trajectories, such as age, gender, education, income, employment status, and health. There is substantial heterogeneity in longitudinal changes in physical activity during the COVID-19 pandemic. However, a substantial proportion of our sample showed persistent physical inactivity or decreasing physical activity. Given the well-established link between physical activity and health, persistent or increased physical inactivity is likely to have both immediate and long-term implications for people’s physical and mental health, as well as general wellbeing. More efforts are needed to promote physical activity during the pandemic and beyond.