bluuebunny/crossref_metadata_2025_split huggingface dataset:
Consumption of artificially sweetened soft drinks and risk of gastrointestinal cancer: a meta-analysis of observational studies
Authors: Jatho Alfred , Cambia Jansen Marcos , Myung Seung-Kwon 
Published: March 2021

AbstractObjective:There remain inconclusive findings from previous observational epidemiological studies on whether consumption of artificially sweetened soft drinks (ASSD) increases the risk of gastrointestinal (GI) cancer. We investigated the associations between the consumption of ASSD and the risk of GI cancer using a meta-analysis.Design:Systematic review and meta-analysis.Setting:PubMed and EMBASE were searched using keywords until May 2020 to identify observational epidemiological studies on the association between the consumption of ASSD and the risk of GI cancer.Subjects:Twenty-one case–control studies and seventeen cohort studies with 12 397 cancer cases and 2 474 452 controls.Results:In the random-effects meta-analysis of all the studies, consumption of ASSD was not significantly associated with the risk of overall GI cancer (OR/relative risk (RR), 1·02; 95 % CI, 0·92, 1·14). There was no significant association between the consumption of ASSD and the risk of overall GI cancer in the subgroup meta-analyses by study design (case–control studies: OR, 0·95; 95 % CI, 0·82, 1·11; cohort studies: RR, 1·14; 95 % CI, 0·97, 1·33). In the subgroup meta-analysis by type of cancer, consumption of ASSD was significantly associated with the increased risk of liver cancer (OR/RR, 1·28; 95 % CI, 1·03, 1·58).Conclusions:The current meta-analysis of observational epidemiological studies suggests that overall, there is no significant association between the consumption of ASSD and the risk of GI cancer.
Thermodynamics of the Magnetotail Current Sheet Thinning
Authors: Yushkov E. V. , Petrukovich A. A. , Artemyev A. V. , Nakamura R. 
Published: March 2021

AbstractSubstorm growth phase in the magnetotail is characterized by formation of a thin current sheet (CS) becomes unstable due to external or internal drivers. Such instability results in magnetic field line reconnection, the substorm onset. The CS thinning, as a key process of substorm dynamics, has been included into many global and local simulations of the magnetotail magnetic reconnection. However, recent observations indicate that the evolution of plasma characteristics and magnetic field configuration during the CS thinning can differ from predictions of the classical adiabatic scenario. In this study, we combine two most extensive datasets of the CS evolution, as observed by Cluster and THEMIS missions for 2001–2009 and 2015, respectively. We show that for a wide range of downtail distances and dawn‐dusk direction there are quite similar quantitative characteristics of the thinning: the magnetic field line stretching (north‐south magnetic field decrease), the intensification of the current density, and the evolution of plasma temperatures and densities. We confirm that the process cannot be directly associated with increase of the lobe magnetic pressure. Using advantages of multispacecraft measurements and CS flapping motion, we demonstrate that the thinning is usually result in the equatorial density increase and plasma temperature decrease. We discuss the revealed evolution features in the context of the thermodynamical CS characteristics for contemporary thinning models.
Pitch Angle Phase Shift in Ring Current Ions Interacting With Ultra‐Low‐Frequency Waves: Van Allen Probes Observations
Authors: Li Xing‐Yu , Liu Zhi‐Yang , Zong Qiu‐Gang , Zhou Xu‐Zhi , Hao Yi‐Xin , Rankin Robert , Zhang Xiao‐Xin 
Published: March 2021

AbstractDrift‐bounce resonance between ultra‐low‐frequency (ULF) waves and ring current ions has been widely studied, because of its important role in ring current acceleration and relevant geomagnetic activities. To identify drift‐bounce resonance in observations, 180° phase shifts across resonant pitch angle have been proposed as diagnostic signatures. This study, however, presents observations that suggest this criterion may be invalid when phase space density (PSD) distributions vary nonmonochromatically with energy. We identified 14 ULF wave‐ion interaction cases from 2‐years Van Allen Probes data. In these cases, 180° phase shifts across pitch angle are observed at particular energies. Near these energies, pitch angle‐dependent PSD bump‐on‐tail distributions were also observed. As a result, at fixed energies, the sign of ion PSD energy gradient changes across pitch angle, which then can result in the observed 180° phase shift. Based on the observations, we suggest 180° phase shifts across pitch angle can also result from pitch angle‐dependent bump‐on‐tail distributions, which should be taken into account in future ULF wave‐ion interaction studies.
Flickering Low Frequency Auroral Hiss
Authors: LaBelle James 
Published: March 2021

AbstractA low‐ and medium‐frequency (LF/MF) receiving system at South Pole Station, using a wide‐beam dipole antenna, measured continuous fully sampled waveforms of more than 100 LF auroral hiss events between June and October 2019. Spectra of fluctuations of LF auroral hiss intensity at selected frequencies between 110 and 530 kHz showed these are broadband, with spectral power monotonically decreasing to an upper bound typically 20–60 Hz, comparable to frequencies reported for optical flickering aurora. Occasionally intervals of periodic fluctuations in auroral hiss intensity occurred, in most cases lasting only tens of cycles. On September 1, 2019, periodic fluctuations lasted thousands of cycles during two 30‐s intervals, at frequencies 125–145 Hz. Close examination showed these to be dispersed with low frequencies arriving before high frequencies by approximately 4.5 ms per 100 kHz. Ray‐tracing calculations and consideration of the Temerin et al. (1986, 1993) mechanisms of flickering aurora shows that the September 1 flickering auroral hiss observations are consistent with resonant amplification of whistler mode noise by an electron beam accelerated and modulated by electromagnetic proton cyclotron waves originating near 4,500 km, with the wave excitation taking place at 2,000–3,000 km.
Combined Optical and Radio‐Frequency Perspectives on a Hybrid Cloud‐To‐Ground Lightning Flash Observed by the FORTE Satellite
Authors: Peterson Michael , Light Tracy E. L. , Shao Xuan‐Min 
Published: March 2021

AbstractWe use the coincident optical and radio‐frequency (RF) measurements taken by the Fast On‐orbit Recording of Transient Events (FORTE) satellite to shed light on common optical signatures recorded by NASA and NOAA lightning imagers during Cloud‐to‐Ground (CG) lightning. We build flash cluster data for FORTE using the same techniques as the NASA/NOAA instruments to document the optical/RF evolution of an oceanic hybrid ‐CG flash. The flash began with strong Very High Frequency (VHF)‐band emission from a Narrow Bipolar Event (NBE) that initiated a period of normal bilevel intracloud (IC) activity in two vertical layers (8 and 12 km) that lasted for 490 ms. VHF waveforms show step leader activity ahead of the return stroke. All impulsive VHF sources after the stroke come from the lower (8 km) layer. K‐changes are noted following the return stroke, but no subsequent strokes are detected. The optical flash began 136 ms after the NBE RF pulse. Twenty‐two of the 33 optical groups were dim and occurred during the in‐cloud phase of the flash. This activity included both isolated pulses and sustained periods of illumination over tens of milliseconds. Initial cloud pulses accounted for 23% of the total optical radiance from the flash. Illumination during the return stroke contributed 58% of the total radiance, and the K‐changes and cloud pulses after the stroke supplied the remaining 19%. These results highlight the benefit of having RF alongside optical lightning measurements for clarifying signatures in the optical data and providing information on their physical origins.
Watershed and Lake Attributes Dictate Landscape Patterns of Resource Flows in Mountain Lakes
Authors: Smits Adrianne P. , Currinder Bryan , Framsted Nicholas , Loken Luke C. , Lucero Delores , Neal Kelly A. , Parisek Christine A. , Sickman Jim , Sadro Steven 
Published: March 2021

AbstractThe extent to which terrestrial organic matter supports aquatic consumers remains uncertain because factors regulating resource flows are poorly understood. We sampled 12 lakes throughout the Sierra Nevada (California, USA) spanning large gradients in elevation and size to evaluate how watershed attributes and lake morphometry influence resource flows to lake carbon pools and zooplankton. We found that the size and composition of carbon pools in lakes were often more strongly determined by watershed or lake features rather than by elevational position. Using three different tracers of resource origin (δ13C, Δ14C, C:N ratio), we found terrestrial contributions to most lake resource pools (dissolved organic carbon, particulate organic matter (POM), sediments) and pelagic consumers (zooplankton) were more strongly related to local‐scale watershed features such as vegetation cover or watershed area: lake area rather than to elevation. Landscape patterns in multiple tracers indicated consistent contribution of within‐lake C sources to bulk resource pools across elevations (POM, sediments, zooplankton). δ13C‐enrichment of lake C pools and overlap with δ13C of terrestrial resources can arise due to reduced fractionation of 13C by phytoplankton under CO2 limitation, therefore we recommend careful consideration of potential environmental drivers when interpreting among‐lake patterns in δ13C. Our findings emphasize the importance of local‐scale variation in mediating terrestrial contributions to lake food webs.
Observed Decrease in Soil and Atmosphere Temperature Coupling in Recent Decades Over Northern Eurasia
Authors: Chen Liangzhi , Aalto Juha , Luoto Miska 
Published: March 2021

AbstractCoupling of soil‐air temperature is fundamentally relevant to various biophysical and biogeochemical functions near the land surface. However, coupling at an interannual scale is less addressed than at finer timescales, such as diurnal and seasonal scales. Here, we show that interannual variability of soil‐air temperature coupling decreased significantly during 1984–2013 across 196 stations in northern Eurasia. Coupling at a depth of 0.2 m remained significant in only 53% of stations during 1999–2013, while it was significant in 80% of stations during 1984–1998. Decreased coupling is mainly attributable to air temperature change in the snow‐free season and snow cover retreat. Moreover, change in the extreme snow cover frequency also contributes to the decline, while other climate extremes are less influential. The findings can help us to understand long‐term land‐climate thermal interactions and to evaluate soil temperature profiles simulated by land surface models.
Morphotype and Crust Effects on the Geochemistry of Globorotalia inflata
Authors: Jonkers Lukas , Gopalakrishnan Akshat , Weßel Lea , Chiessi Cristiano M. , Groeneveld Jeroen , Monien Patrick , Lessa Douglas , Morard Raphaël 
Published: March 2021

AbstractSedimentary specimens of the planktonic foraminifera Globorotalia inflata can provide information on subsurface conditions of past oceans. However, interpretation of their geochemical signal is complicated by possible effects of cryptic diversity and encrustation. Here we address these issues using plankton tow and sediment samples from the western South Atlantic, where two genotypes of G. inflata occur. To separate the genotypes, we analyzed shells from the extreme ends of the morphospace of G. inflata. The δ18O and δ13C of encrusted specimens from both morphotypes are indistinguishable. However, we do find a large influence of encrustation on δ18O and Mg/Ca. Whereas crust Mg/Ca ratios are at all locations lower than lamellar calcite, the crust effect on δ18O is less consistent in space. Plankton tows show that encrusted specimens occur at any depth and that even close to the surface crust Mg/Ca ratios are lower than in lamellar calcite. This is inconsistent with formation of the crust at lower temperature at greater depth. Instead we suggest that the difference between the crust and lamellar calcite Mg/Ca ratio is temperature‐independent and due to the presence of high Mg/Ca bands only in the lamellar calcite. The variable crust effect on δ18O is more difficult to explain, but the higher incidence of crust‐free specimens in warmer waters and the observation that a crust effect is clearest in the confluence zone, hint at the possibility that the difference reflects advective mixing of specimens from warmer and colder areas, rather than vertical migration.
Caribbean plate tilted and actively dragged eastwards by low-viscosity asthenospheric flow
Authors: Chen Yi-Wei , Colli Lorenzo , Bird Dale E. , Wu Jonny , Zhu Hejun 
Published: March 2021

AbstractThe importance of a low-viscosity asthenosphere underlying mobile plates has been highlighted since the earliest days of the plate tectonics revolution. However, absolute asthenospheric viscosities are still poorly constrained, with estimates spanning up to 3 orders of magnitude. Here we follow a new approach using analytic solutions for Poiseuille-Couette channel flow to compute asthenospheric viscosities under the Caribbean. We estimate Caribbean dynamic topography and the associated pressure gradient, which, combined with flow velocities estimated from geologic markers and tomographic structure, yield our best-estimate asthenospheric viscosity of (3.0 ± 1.5)*1018 Pa s. This value is consistent with independent estimates for non-cratonic and oceanic regions, and challenges the hypothesis that higher-viscosity asthenosphere inferred from postglacial rebound is globally-representative. The active flow driven by Galapagos plume overpressure shown here contradicts the traditional view that the asthenosphere is only a passive lubricating layer for Earth’s tectonic plates.
Warming from tropical deforestation reduces worker productivity in rural communities
Authors: Masuda Yuta J. , Garg Teevrat , Anggraeni Ike , Ebi Kristie , Krenz Jennifer , Game Edward T. , Wolff Nicholas H. , Spector June T. 
Published: March 2021

AbstractThe accelerating loss of tropical forests in the 21st century has eliminated cooling services provided by trees in low latitude countries. Cooling services can protect rural communities and outdoor workers with little adaptive capacity from adverse heat exposure, which is expected to increase with climate change. Yet little is still known about whether cooling services can mitigate negative impacts of heat on labor productivity among rural outdoor workers. Through a field experiment in Indonesia, we show that worker productivity was 8.22% lower in deforested relative to forested settings, where wet bulb globe temperatures were, on average, 2.84 °C higher in deforested settings. We demonstrate that productivity losses are driven by behavioral adaptations in the form of increased number of work breaks, and provide evidence that suggests breaks are in part driven by awareness of heat effects on work. Our results indicate that the cooling services from forests have the potential for increasing resilience and adaptive capacity to local warming.
Joint profiling of DNA and proteins in single cells to dissect genotype-phenotype associations in leukemia
Authors: Demaree Benjamin , Delley Cyrille L. , Vasudevan Harish N. , Peretz Cheryl A. C. , Ruff David , Smith Catherine C. , Abate Adam R. 
Published: March 2021

AbstractStudies of acute myeloid leukemia rely on DNA sequencing and immunophenotyping by flow cytometry as primary tools for disease characterization. However, leukemia tumor heterogeneity complicates integration of DNA variants and immunophenotypes from separate measurements. Here we introduce DAb-seq, a technology for simultaneous capture of DNA genotype and cell surface phenotype from single cells at high throughput, enabling direct profiling of proteogenomic states in tens of thousands of cells. To demonstrate the approach, we analyze the disease of three patients with leukemia over multiple treatment timepoints and disease recurrences. We observe complex genotype-phenotype dynamics that illustrate the subtlety of the disease process and the degree of incongruity between blast cell genotype and phenotype in different clinical scenarios. Our results highlight the importance of combined single-cell DNA and protein measurements to fully characterize the heterogeneity of leukemia.
mTORC1 couples cyst(e)ine availability with GPX4 protein synthesis and ferroptosis regulation
Authors: Zhang Yilei , Swanda Robert V. , Nie Litong , Liu Xiaoguang , Wang Chao , Lee Hyemin , Lei Guang , Mao Chao , Koppula Pranavi , Cheng Weijie , Zhang Jie , Xiao Zhenna , Zhuang Li , Fang Bingliang , Chen Junjie , Qian Shu-Bing , Gan Boyi 
Published: March 2021

AbstractGlutathione peroxidase 4 (GPX4) utilizes glutathione (GSH) to detoxify lipid peroxidation and plays an essential role in inhibiting ferroptosis. As a selenoprotein, GPX4 protein synthesis is highly inefficient and energetically costly. How cells coordinate GPX4 synthesis with nutrient availability remains unclear. In this study, we perform integrated proteomic and functional analyses to reveal that SLC7A11-mediated cystine uptake promotes not only GSH synthesis, but also GPX4 protein synthesis. Mechanistically, we find that cyst(e)ine activates mechanistic/mammalian target of rapamycin complex 1 (mTORC1) and promotes GPX4 protein synthesis at least partly through the Rag-mTORC1-4EBP signaling axis. We show that pharmacologic inhibition of mTORC1 decreases GPX4 protein levels, sensitizes cancer cells to ferroptosis, and synergizes with ferroptosis inducers to suppress patient-derived xenograft tumor growth in vivo. Together, our results reveal a regulatory mechanism to coordinate GPX4 protein synthesis with cyst(e)ine availability and suggest using combinatorial therapy of mTORC1 inhibitors and ferroptosis inducers in cancer treatment.
Hepatitis B virus cccDNA is formed through distinct repair processes of each strand
Authors: Wei Lei , Ploss Alexander 
Published: March 2021

AbstractHepatitis B virus (HBV) is a highly contagious pathogen that afflicts over a third of the world’s population, resulting in close to a million deaths annually. The formation and persistence of the HBV covalently closed circular DNA (cccDNA) is the root cause of HBV chronicity. However, the detailed molecular mechanism of cccDNA formation from relaxed circular DNA (rcDNA) remains opaque. Here we show that the minus and plus-strand lesions of HBV rcDNA require different sets of human repair factors in biochemical repair systems. We demonstrate that the plus-strand repair resembles DNA lagging strand synthesis, and requires proliferating cell nuclear antigen (PCNA), the replication factor C (RFC) complex, DNA polymerase delta (POLδ), flap endonuclease 1 (FEN-1), and DNA ligase 1 (LIG1). Only FEN-1 and LIG1 are required for the repair of the minus strand. Our findings provide a detailed mechanistic view of how HBV rcDNA is repaired to form cccDNA in biochemical repair systems.
A randomised controlled trial to reduce highest priority critically important antimicrobial prescription in companion animals
Authors: Singleton David A. , Rayner Angela , Brant Bethaney , Smyth Steven , Noble Peter-John M. , Radford Alan D. , Pinchbeck Gina L. 
Published: March 2021

AbstractRobust evidence supporting strategies for companion animal antimicrobial stewardship is limited, despite frequent prescription of highest priority critically important antimicrobials (HPCIA). Here we describe a randomised controlled trial where electronic prescription data were utilised (August 2018–January 2019) to identify above average HPCIA-prescribing practices (n = 60), which were randomly assigned into a control group (CG) and two intervention groups. In March 2019, the light intervention group (LIG) and heavy intervention group (HIG) were notified of their above average status, and were provided with educational material (LIG, HIG), in-depth benchmarking (HIG), and follow-up meetings (HIG). Following notification, follow-up monitoring lasted for eight months (April–November 2019; post-intervention period) for all intervention groups, though HIG practices were able to access further support (i.e., follow-up meetings) for the first six of these months if requested. Post-intervention, in the HIG a 23.5% and 39.0% reduction in canine (0.5% of total consultations, 95% confidence interval, 0.4-0.6, P = 0.04) and feline (4.4%, 3.4-5.3, P < 0.001) HPCIA-prescribing consultations was observed, compared to the CG (dogs: 0.6%, 0.5-0.8; cats: 7.4%, 6.0-8.7). The LIG was associated with a 16.7% reduction in feline HPCIA prescription (6.1% of total consultations, 5.3-7.0, P = 0.03). Therefore, in this trial we have demonstrated effective strategies for reducing veterinary HPCIA prescription.
DeepTCR is a deep learning framework for revealing sequence concepts within T-cell repertoires
Authors: Sidhom John-William , Larman H. Benjamin , Pardoll Drew M. , Baras Alexander S. 
Published: March 2021

AbstractDeep learning algorithms have been utilized to achieve enhanced performance in pattern-recognition tasks. The ability to learn complex patterns in data has tremendous implications in immunogenomics. T-cell receptor (TCR) sequencing assesses the diversity of the adaptive immune system and allows for modeling its sequence determinants of antigenicity. We present DeepTCR, a suite of unsupervised and supervised deep learning methods able to model highly complex TCR sequencing data by learning a joint representation of a TCR by its CDR3 sequences and V/D/J gene usage. We demonstrate the utility of deep learning to provide an improved ‘featurization’ of the TCR across multiple human and murine datasets, including improved classification of antigen-specific TCRs and extraction of antigen-specific TCRs from noisy single-cell RNA-Seq and T-cell culture-based assays. Our results highlight the flexibility and capacity for deep neural networks to extract meaningful information from complex immunogenomic data for both descriptive and predictive purposes.
Novel evolutionary dynamics of small populations in breast cancer adjuvant and neoadjuvant therapy
Authors: Artzy-Randrup Yael , Epstein Tamir , Brown Joel S. , Costa Ricardo L. B. , Czerniecki Brian J. , Gatenby Robert A. 
Published: March 2021

AbstractDisseminated cancer cells (DCCs) are detected in the circulation and bone marrow of up to 40% of breast cancer (BC) patients with clinically localized disease. The formation of metastases is governed by eco-evolutionary interactions of DCCs with the tissue during the transition from microscopic populations to macroscopic disease. Here, we view BC adjuvant and neoadjuvant treatments in the context of small population extinction dynamics observed in the Anthropocene era. Specifically, the unique eco-evolutionary dynamics of small asexually reproducing cancer populations render them highly vulnerable to: (1) environmental and demographic fluctuations, (2) Allee effects, (3) genetic drift and (4) population fragmentation. Furthermore, these typically interact, producing self-reinforcing, destructive dynamics—termed the Extinction Vortex—eradicating the population even when none of the perturbations is individually capable of causing extinction. We propose that developing BC adjuvant and neoadjuvant protocols may exploit these dynamics to prevent recovery and proliferation of small cancer populations during and after treatment—termed “Eco-evolutionary rescue” in natural extinctions. We hypothesize more strategic application of currently available agents based on the extinction vulnerabilities of small populations could improve clinical outcomes.