bluuebunny/crossref_metadata_2025_split huggingface dataset:
Venus: A Thick Basal Magma Ocean May Exist Today
Authors: O'Rourke J. G. 
Published: February 2020

AbstractBasal magma oceans develop in Earth and Venus after accretion as their mantles solidify from the middle outward. Fractional crystallization of the basal mantle is buffered by the core and radiogenic and latent heat in the magma ocean. Previous studies showed that Earth's basal magma ocean would have solidified after two or three billion years. Venus has a relatively hot interior that cools slowly in the absence of plate tectonics, which reduces heat flow through the solid mantle. Consequentially, the basal magma ocean could remain as thick as ~200–400 km today. Vigorous convection of liquid silicates could power a global magnetic field until recently while a core‐hosted dynamo is suppressed. The basal magma ocean may be a hidden reservoir of potassium and other incompatible elements. A high tidal Love number could reveal a basal magma ocean and would definitively establish that the core is at least partially liquid.
Three dimensional Gravity Local Inversion Across the Area Struck by the 2016–2017 Seismic Events in Central Italy
Authors: Mancinelli Paolo , Pauselli Cristina , Fournier Dominique , Fedi Maurizio , Minelli Giorgio , Barchi Massimiliano R. 
Published: February 2020

AbstractIn this work, the crustal volume struck by the 2016–2017 seismic sequence in Central and Northern Apennines is investigated using constrained 3‐D inversion of the gravity anomalies. In order to focus on the area comprising the two mainshocks of the sequence, we perform a regional field removal on the data as a preprocessing step. This residual data set is then inverted into a 3‐D density contrast model. We perform a series of inversions to test different geological scenarios and parameters, with increasing complexity in the reference geometries. We first test a model comprising turbidites, carbonates and evaporites, and basement and then introduce a low‐density layer at the top of the basement. The geometries are obtained in agreement with the available geological and geophysical information in the area. We found that the density distribution with depth is compatible with previous models. Moreover, results support the hypothesis based on borehole evidence of a low‐density upper basement across the entire area, possibly consisting of low‐grade metamorphic rocks (phyllites). Finally, we compare our modeling results to the spatial distribution at depth of major seismic events between August and November 2016. These events appear to be concentrated within the denser units at both shallow and deep locations, while the deeper events often occur in a region of major density contrast corresponding to the top of the basement.
Chemo‐mechanical Alterations Induced From CO2 Injection in Carbonate‐Cemented Sandstone: An Experimental Study at 71 °C and 29 MPa
Authors: Wu Z. , Luhmann A. J. , Rinehart A. J. , Mozley P. S. , Dewers T. A. , Heath J. E. , Majumdar B. S. 
Published: February 2020

AbstractCarbon capture, utilization, and storage may lead to mechanical degradation of the subsurface reservoir from fluid‐rock interaction, which could lead to wellbore instability or reservoir compaction. To better understand potential relationship between mechanical degradation with various carbonate cement textures and compositions in sandstone reservoirs, six flow‐through experiments were conducted. Formation water (TDS = 5,390 mg/L) enriched with CO2 flowed through two types of Pennsylvanian Morrow B Sandstone: an ankerite‐siderite‐cemented sandstone (disseminated cement texture) and a calcite‐cemented sandstone (poikilotopic cement texture). The experiments produced little change in permeability in the ankerite‐siderite‐cemented sandstone, but permeability increased up to more than 1 order of magnitude in the calcite‐cemented sandstone. Ultrasonic measurements and cylinder‐splitting tests (also known as Brazilian tests) suggested negligible mechanical degradation of the ankerite‐siderite‐cemented sandstone. Variable changes, with significant mechanical degradation in the static moduli, were observed in the calcite‐cemented sandstone. Thus, dissolution of the disseminated ankerite‐siderite cement (0.28–0.30%) had minimal impact on modifying the flow network and the mechanical integrity of the sandstone, whereas dissolution of the poikilotopic calcite cement (0.89–1.13%, quantified with fluid chemistry and visualized with X‐ray microcomputed tomography) impacted the mechanical strength of the sandstone by disconnecting framework grains. With the high water‐to‐rock mass ratios (7.3–8.2) and number of pore volumes (147–675) employed in these experiments, potential risks are most relevant to regions near injection wells. Ultimately, the chemo‐mechanical effects induced by CO2 injection are strongly influenced by the cement texture and composition and the burial history of the reservoir rock.
Features of Slope Intrusion Mesoscale Eddies in the Northern South China Sea
Authors: Su Danyi , Lin Pengfei , Mao Huabin , Wu Jiaxue , Liu Hailong , Cui Yongsheng , Qiu Chunhua 
Published: February 2020

AbstractSome mesoscale eddies intrude over the continental slope in the northern South China Sea, supporting cross‐shelf matter transport. We investigated the characteristics, the intruding tracks and formation mechanisms, of slope intrusion mesoscale eddies using satellite altimeter data and model outputs. In total, 36 and 22 slope intrusion anticyclonic and cyclonic eddies (SAEs/SCEs) are found, respectively. Slope intrusion eddies have longer lifetimes (~58 days), smaller size (~110 km), and greater eddy kinetic energy and vorticity compared to ordinary eddies but are more unstable and more easily deformed during their life cycles. The statistical results show that more slope intrusion eddies are generated during winter than other seasons. It is found that slope intrusion eddies mainly propagate westward/northwestward, and southwestward along the continental slope and shelf. Eddy intrusions occur mainly near the Dongsha Islands, east of Hainan, and north of the Xisha Islands. SAEs continue to propagate onshore after arrival at the continental slope, while SCEs dissipate more quickly. Using mooring data, we found that eddy‐ambient flow interaction could cause the differences between SAEs and SCEs around the Dongsha Islands. Energy conversion was analyzed in these three regions using numerical products. During intrusion, eddies lose eddy kinetic energy and ambient flows gain energy.
Vertical Turbulent Cooling of the Mixed Layer in the Atlantic ITCZ and Trade Wind Regions
Authors: Foltz Gregory R. , Hummels Rebecca , Dengler Marcus , Perez Renellys C. , Araujo Moacyr 
Published: February 2020

AbstractThe causes of the seasonal cycle of vertical turbulent cooling at the base of the mixed layer are assessed using observations from moored buoys in the tropical Atlantic Intertropical Convergence Zone (ITCZ) (4°N, 23°W) and trade wind (15°N, 38°W) regions together with mixing parameterizations and a one‐dimensional model. At 4°N the parameterized turbulent cooling rates during 2017–2018 and 2019 agree with indirect estimates from the climatological mooring heat budget residual: both show mean cooling of 25–30 W m
during November–July, when winds are weakest and the mixed layer is thinnest, and 0–10 W m
during August–October. Mixing during November–July is driven by variability on multiple time scales, including subdiurnal, near‐inertial, and intraseasonal. Shear associated with tropical instability waves (TIWs) is found to generate mixing and monthly mean cooling of 15–30 W m
during May–July in 2017 and 2019. At 15°N the seasonal cycle of turbulent cooling is out of phase compared to 4°N, with largest cooling of up to 60 W m
during boreal fall. However, the relationships between wind speed, mixed layer depth, and turbulent mixing are similar: weaker mean winds and a thinner mixed layer in the fall are associated with stronger mixing and turbulent cooling of SST. These results emphasize the importance of seasonal modulations of mixed layer depth at both locations and shear from TIWs at 4°N.
Does the Mass Balance of the Reactive Tracers Resazurin and Resorufin Close at the Microbial Scale?
Authors: Dallan Eleonora , Regier Peter , Marion Andrea , González‐Pinzón Ricardo 
Published: February 2020

AbstractResazurin (Raz) is a phenoxazine dye that can be reduced irreversibly to the daughter compound resorufin (Rru) by aerobic respiration. Previous hydrologic studies using the Raz‐Rru reactive tracer system to quantify water‐sediment interactions and metabolic activity have reported that dilution‐corrected masses of Raz and Rru recovered are smaller than the mass of Raz injected. This lack of mass balance closure has been reported as a nonideality of this tracer system and, to date, it is still unclear what drives incomplete recovery. We used controlled laboratory experiments varying the initial concentrations of Raz, the duration of the experiments, and the type of microbial communities present to quantify mass balances of Raz and Rru under conditions that removed other suspected causes of incomplete recovery in field experiments, i.e., sorption to sediments and photodecay. We used the summation of Raz and Rru concentrations over time to assess mass recovery and variability and found mass recoveries in the range of 85.6–110.4%, with a maximum standard deviation of 7.5%. In three of the four experiments, no strong temporal trend in mass recovery is present. In an experiment with Bacillus subtilis bacteria, lower recovery and evidence of a temporal trend in recovery only occurred after 13 hr past the complete transformation of Raz (i.e., beyond the duration of most field experiments). These results suggest that the lack of mass recovery in field studies is likely associated with physical or chemical mechanisms rather than biological interactions with the Raz‐Rru tracer system.
Active sulfur cycling in the terrestrial deep subsurface
Authors: Bell Emma , Lamminmäki Tiina , Alneberg Johannes , Andersson Anders F , Qian Chen , Xiong Weili , Hettich Robert L , Frutschi Manon , Bernier-Latmani Rizlan 
Published: February 2020

AbstractThe deep terrestrial subsurface remains an environment where there is limited understanding of the extant microbial metabolisms. At Olkiluoto, Finland, a deep geological repository is under construction for the final storage of spent nuclear fuel. It is therefore critical to evaluate the potential impact microbial metabolism, including sulfide generation, could have upon the safety of the repository. We investigated a deep groundwater where sulfate is present, but groundwater geochemistry suggests limited microbial sulfate-reducing activity. Examination of the microbial community at the genome-level revealed microorganisms with the metabolic capacity for both oxidative and reductive sulfur transformations. Deltaproteobacteria are shown to have the genetic capacity for sulfate reduction and possibly sulfur disproportionation, while Rhizobiaceae, Rhodocyclaceae, Sideroxydans, and Sulfurimonas oxidize reduced sulfur compounds. Further examination of the proteome confirmed an active sulfur cycle, serving for microbial energy generation and growth. Our results reveal that this sulfide-poor groundwater harbors an active microbial community of sulfate-reducing and sulfide-oxidizing bacteria, together mediating a sulfur cycle that remained undetected by geochemical monitoring alone. The ability of sulfide-oxidizing bacteria to limit the accumulation of sulfide was further demonstrated in groundwater incubations and highlights a potential sink for sulfide that could be beneficial for geological repository safety.
Refined spatial temporal epigenomic profiling reveals intrinsic connection between PRDM9-mediated H3K4me3 and the fate of double-stranded breaks
Authors: Chen Yao , Lyu Ruitu , Rong Bowen , Zheng Yuxuan , Lin Zhen , Dai Ruofei , Zhang Xi , Xie Nannan , Wang Siqing , Tang Fuchou , Lan Fei , Tong Ming-Han 
Published: February 2020

AbstractMeiotic recombination is initiated by the formation of double-strand breaks (DSBs), which are repaired as either crossovers (COs) or noncrossovers (NCOs). In most mammals, PRDM9-mediated H3K4me3 controls the nonrandom distribution of DSBs; however, both the timing and mechanism of DSB fate control remain largely undetermined. Here, we generated comprehensive epigenomic profiles of synchronized mouse spermatogenic cells during meiotic prophase I, revealing spatiotemporal and functional relationships between epigenetic factors and meiotic recombination. We find that PRDM9-mediated H3K4me3 at DSB hotspots, coinciding with H3K27ac and H3K36me3, is intimately connected with the fate of the DSB. Our data suggest that the fate decision is likely made at the time of DSB formation: earlier formed DSBs occupy more open chromatins and are much more competent to proceed to a CO fate. Our work highlights an intrinsic connection between PRDM9-mediated H3K4me3 and the fate decision of DSBs, and provides new insight into the control of CO homeostasis.
Nanocatalytic activity of clean-surfaced, faceted nanocrystalline gold enhances remyelination in animal models of multiple sclerosis
Authors: Robinson Andrew P. , Zhang Joanne Zhongyan , Titus Haley E. , Karl Molly , Merzliakov Mikhail , Dorfman Adam R. , Karlik Stephen , Stewart Michael G. , Watt Richard K. , Facer Benjin D. , Facer Jon D. , Christian Noah D. , Ho Karen S. , Hotchkin Michael T. , Mortenson Mark G. , Miller Robert H. , Miller Stephen D. 
Published: February 2020

AbstractDevelopment of pharmacotherapies that promote remyelination is a high priority for multiple sclerosis (MS), due to their potential for neuroprotection and restoration of function through repair of demyelinated lesions. A novel preparation of clean-surfaced, faceted gold nanocrystals demonstrated robust remyelinating activity in response to demyelinating agents in both chronic cuprizone and acute lysolecithin rodent animal models. Furthermore, oral delivery of gold nanocrystals improved motor functions of cuprizone-treated mice in both open field and kinematic gait studies. Gold nanocrystal treatment of oligodendrocyte precursor cells in culture resulted in oligodendrocyte maturation and expression of myelin differentiation markers. Additional in vitro data demonstrated that these gold nanocrystals act via a novel energy metabolism pathway involving the enhancement of key indicators of aerobic glycolysis. In response to gold nanocrystals, co-cultured central nervous system cells exhibited elevated levels of the redox coenzyme nicotine adenine dinucleotide (NAD+), elevated total intracellular ATP levels, and elevated extracellular lactate levels, along with upregulation of myelin-synthesis related genes, collectively resulting in functional myelin generation. Based on these preclinical studies, clean-surfaced, faceted gold nanocrystals represent a novel remyelinating therapeutic for multiple sclerosis.
HemoSYS: A Toolkit for Image-based Systems Biology of Tumor Hemodynamics
Authors: Senarathna Janaka , Prasad Ayush , Bhargava Akanksha , Gil Stacy , Thakor Nitish V. , Pathak Arvind P. 
Published: February 2020

AbstractAbnormal tumor hemodynamics are a critical determinant of a tumor’s microenvironment (TME), and profoundly affect drug delivery, therapeutic efficacy and the emergence of drug and radio-resistance. Since multiple hemodynamic variables can simultaneously exhibit transient and spatiotemporally heterogeneous behavior, there is an exigent need for analysis tools that employ multiple variables to characterize the anomalous hemodynamics within the TME. To address this, we developed a new toolkit called HemoSYS for quantifying the hemodynamic landscape within angiogenic microenvironments. It employs multivariable time-series data such as in vivo tumor blood flow (BF), blood volume (BV) and intravascular oxygen saturation (Hbsat) acquired concurrently using a wide-field multicontrast optical imaging system. The HemoSYS toolkit consists of propagation, clustering, coupling, perturbation and Fourier analysis modules. We demonstrate the utility of each module for characterizing the in vivo hemodynamic landscape of an orthotropic breast cancer model. With HemoSYS, we successfully described: (i) the propagation dynamics of acute hypoxia; (ii) the initiation and dissolution of distinct hemodynamic niches; (iii) tumor blood flow regulation via local vasomotion; (iv) the hemodynamic response to a systemic perturbation with carbogen gas; and (v) frequency domain analysis of hemodynamic heterogeneity in the TME. HemoSYS (freely downloadable via the internet) enables vascular phenotyping from multicontrast in vivo optical imaging data. Its modular design also enables characterization of non-tumor hemodynamics (e.g. brain), other preclinical disease models (e.g. stroke), vascular-targeted therapeutics, and hemodynamic data from other imaging modalities (e.g. MRI).
Genome-wide screening of lipoproteins in Actinobacillus pleuropneumoniae identifies three antigens that confer protection against virulent challenge
Authors: Cao Yurou , Gao Lulu , Zhang Li , Zhou Lixiang , Yang Jihong , Deng Lingfu , Zhao Jin , Qi Chao , Liu Jinlin 
Published: February 2020

AbstractActinobacillus pleuropneumoniaeis an important veterinary pathogen that causes porcine pleuropneumonia. Lipoproteins of bacterial pathogens play pleiotropic roles in the infection process. In addition, many bacterial lipoproteins are antigenic and immunoprotective. Therefore, characterization of lipoproteins is a promising strategy for identification of novel vaccine candidates or diagnostic markers. We cloned 58 lipoproteins fromA.pleuropneumoniaeJL03 (serovar 3) and expressed them inEscherichia coli. Five proteins with strong positive signals in western blotting analysis were used to immunize mice. These proteins elicited significant antibody responses, and three of them (APJL_0922, APJL_1380 and APJL_1976) generated efficient immunoprotection in mice against lethal heterologous challenge withA.pleuropneumoniae4074 (serovar 1), both in the active and passive immunization assays. Then immunogenicity of these three lipoproteins (APJL_0922, APJL_1380 and APJL_1976) were further tested in pigs. Results showed that these proteins elicited considerable humoral immune responses and effective protective immunity against virulentA.pleuropneumoniaechallenge. Our findings suggest that these three novel lipoproteins could be potential subunit vaccine candidates.
A secreted protein of 15 kDa plays an important role in Phytophthora palmivora development and pathogenicity
Authors: Pettongkhao Sittiporn , Navet Natasha , Schornack Sebastian , Tian Miaoying , Churngchow Nunta 
Published: February 2020

AbstractPhytophthora palmivorais a destructive oomycete plant pathogen with a wide host range. So far, little is known about the factors governing its infection structure development and pathogenicity. From the culture filtrate of aP. palmivorastrain isolated from papaya, we identified a secreted glycoprotein of 15 kDa, designated as Ppal15kDa, using liquid chromatography tandem mass spectrometry. Two gene variants,Ppal15kDaAandPpal15kDaBwere amplified from aP. palmivorapapaya isolate. Transient expression of both variants inNicotiana benthamianaby agroinfiltration enhancedP. palmivorainfection. SixPpal15kDamutants with diverse mutations were generated via CRISPR/Cas9-mediated gene editing. All mutants were compromised in infectivity onN. benthamianaand papaya. Two mutants with allPpal15kDacopies mutated almost completely lost pathogenicity. The pathogenicity of the other four containing at least one wild-type copy ofPpal15kDawas compromised at varying levels. The mutants were also affected in development as they produced smaller sporangia, shorter germ tubes, and fewer appressoria. The affected levels in development corresponded to the levels of reduction in pathogenicity, suggesting that Ppal15kDa plays an important role in normal development ofP. palmivorainfection structures. Consistent with its role in infection structure development and pathogenicity,Ppal15kDawas found to be highly induced during appressorium formation. In addition, Ppal15kDa homologs are broadly present inPhytophthoraspp., but none were characterized. Altogether, this study identified a novel component involved in development and pathogenicity ofP. palmivoraand possibly otherPhytophthoraspp. known to contain a Ppal15kDa homolog.
Discoidin Domain Receptors, DDR1b and DDR2, Promote Tumour Growth within Collagen but DDR1b Suppresses Experimental Lung Metastasis in HT1080 Xenografts
Authors: Wasinski Benjamin , Sohail Anjum , Bonfil R. Daniel , Kim Seongho , Saliganan Allen , Polin Lisa , Bouhamdan Mohamad , Kim Hyeong-Reh C. , Prunotto Marco , Fridman Rafael 
Published: February 2020

AbstractThe Discoidin Domain Receptors (DDRs) constitute a unique set of receptor tyrosine kinases that signal in response to collagen. Using an inducible expression system in human HT1080 fibrosarcoma cells, we investigated the role of DDR1b and DDR2 on primary tumour growth and experimental lung metastases. Neither DDR1b nor DDR2 expression altered tumour growth at the primary site. However, implantation of DDR1b- or DDR2-expressing HT1080 cells with collagen I significantly accelerated tumour growth rate, an effect that could not be observed with collagen I in the absence of DDR induction. Interestingly, DDR1b, but not DDR2, completely hindered the ability of HT1080 cells to form lung colonies after intravenous inoculation, suggesting a differential role for DDR1b in primary tumour growth and lung colonization. Analyses of tumour extracts revealed specific alterations in Hippo pathway core components, as a function of DDR and collagen expression, that were associated with stimulation of tumour growth by DDRs and collagen I. Collectively, these findings identified divergent effects of DDRs on primary tumour growth and experimental lung metastasis in the HT1080 xenograft model and highlight the critical role of fibrillar collagen and DDRs in supporting the growth of tumours thriving within a collagen-rich stroma.
Seasonal variations in cause-specific mortality and transition to renal replacement therapy among patients with end-stage renal disease
Authors: Goto Shunsuke , Hamano Takayuki , Ogata Satoshi , Masakane Ikuto 
Published: February 2020

AbstractDespite some studies showing seasonal variations in mortality and the transition to renal replacement therapy in patients with end-stage renal disease, detailed evidence is still scarce. We investigated seasonal variations in patients with end-stage renal disease using a large Japanese database for dialysis patients. We compared the fractions of all-cause and cause-specific mortality and the transition to renal replacement therapy among seasons and performed a mixed-effects Poisson regression analysis to compare the mortality among seasons after adjustment for some variables. The initiation of hemodialysis was highest in winter and lowest in summer. Seasonality in the initiation of peritoneal dialysis and transition to kidney transplantation differed from hemodialysis. All-cause mortality was highest in the winter and lowest in the summer. Death from coronary artery disease, heart failure, cerebral hemorrhage, and infectious pneumonia had similar seasonality, but death from cerebral infarction, septicemia, or malignant tumor did not have similar seasonality. In conclusion, the initiation of hemodialysis, all-cause mortality, and mortality from coronary heart disease, heart failure, cerebral hemorrhage, and infectious pneumonia were significantly highest in winter and lowest in summer. However, the initiation of peritoneal dialysis, transition to kidney transplantation, or mortality from cerebral infarction, septicemia, or malignant tumor did not have similar seasonal variations.