bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defining the gift
Authors: Elder-Vass Dave 
Published: July 2019

AbstractEconomics has tended to neglect giving, and thus both its important contemporary economic role and its potential contribution to alternative, non-market systems. To remedy this, it will need to draw on the broad debates on the nature of the gift that have developed in and across the other social sciences. This paper addresses several of these by asking how we should define the termsgiftandgiving. It rejects definitional associations of giving with obligation, reciprocity and the development of social relationships. Such definitions exclude many phenomena commonly understood as giving and underpin misguided attempts to analyse gifts in contemporary late-modern societies in terms derived from anthropological discussions of very different societies. Instead, the paper develops a definition of the gift based on contemporary giving institutions. A more open, contemporary definition of the gift helps to sensitise us to the continuing importance of gift institutions in social and economic life.
Modeling Ultralow Velocity Zones as a Thin Chemically Distinct Dense Layer at the Core‐Mantle Boundary
Authors: Hernlund John William , Bonati Irene 
Published: July 2019

AbstractSeismically detected ultralow velocity zones (ULVZs) at the the core‐mantle boundary reflect the dynamical state and geological evolution of the silicate‐metal frontier of Earth's deep interior. However, modeling the dynamical context of ULVZs is hampered by challenges, such as the necessity of fine‐scale resolution and the accurate treatment of large viscosity contrasts. Here we extend the treatment of ULVZs using a lubrication theory approach and apply it to numerical and analytical models relevant for mantle convection in the core‐mantle boundary region. A generic model of a thin and dense low‐viscosity ULVZ layer embedded between an overlying convecting viscous mantle and an underlying inviscid core can explain several features that are consistent with seismic inferences, such as the absence of ULVZs in some regions and a tabular shape where they are concentrated. The model explains how the topography of a ULVZ layer tends to saturate and flatten as it becomes thicker, due to a nonlinear feedback between viscous aggregation beneath upwelling mantle currents and gravitational spreading/relaxation. Implementation of the ULVZ equation in thermal convection models indicates that ULVZs are preferentially gathered beneath long‐lived plumes and may not exist beneath newly formed plume roots where there is no source of layer material. The presence/absence of ULVZs and their detailed shapes may provide important insights into the dynamical state and convective instability of the lowermost mantle thermal boundary layer.
Interannual Variability in the Absorption and Fluorescence Characteristics of Dissolved Organic Matter in the Canada Basin Polar Mixed Waters
Authors: Dainard P. G. , Guéguen C. , Yamamoto‐Kawai M. , Williams W. J. , Hutchings J. K. 
Published: June 2019

AbstractDissolved organic matter (DOM) absorption and fluorescence properties were investigated for seawater samples collected from the polar mixed layer (0–30 m) of the Canada Basin in 2010–2012. Sea ice concentration as well as fractions of meteoric and sea ice meltwater (fMW and fSIM) calculated from oxygen isotope ratio (δ18O) were applied to assess the importance of discrete freshwater inputs to the distribution of DOM. Parallel factor analysis identified four humic‐like (C1‐2 and C4‐C5) and one protein‐like (C3) fluorescent components in 380 excitation‐emission matrix spectra. Surprisingly, despite different sea ice cover and biological regimes, DOM composition was largely homogeneous spanning these annual surveys. A strong and reoccurring coastal influence on DOM absorption and humic‐like DOM was observed each year and was particularly pronounced during the summer 2011 survey. Enrichment of DOM humic signal (C1, C2, and C4) in brine‐rich (fSIM < 0) waters relative to sea ice melt‐dominated waters (fSIM > 0; p < 0.05) was found during 2011 and 2012 in the offshore region (>76°N) where coastal influences were minimal (fMW < 0.1). Similar fSIM < 0 were found for 2011 and 2012, either when considering the Canada Basin as a whole or the offshore region (>76°N) exclusively, which could imply that brine formation influenced humic signals in polar mixed layer seawater. Findings herein highlight that future projected changes in freshwater sources and brine production in the Canada Basin will likely implicate the distribution and composition of DOM.
Sensitivity of Gravity‐Wave Momentum Flux to Moisture in the Mei‐Yu Front Systems
Authors: Wang Yuan , Zhang Lifeng , Zhang Yun , Peng Jun , Yu Shiwang 
Published: July 2019

AbstractThe sensitivity of gravity‐wave momentum flux in the Mei‐Yu front systems to moisture is investigated via idealized simulations with various degrees of initial moisture content. Gravity waves generated in moist experiments result in net northward momentum flux and drag forcing, and the drag is indistinctive in the lower stratosphere near the tropopause but strengthens with height. As moisture content increases, the meridional flux intensifies remarkably in both physical and spectral space and extends to smaller spatiotemporal scales. However, the change of moisture has little effect on the selectivity of the strongest flux to relatively large scales and specific phase speeds. At slow phase speeds, the fanlike waves excited by the front are effectively coupled with the convective waves excited by the prefrontal moist convection, which leads to the weakening of the coupled wave flux.
Pedersen Ionic Contribution in Different Time Scales
Authors: Zossi Bruno S. , Fagre Mariano , Elias Ana G. 
Published: July 2019

AbstractPedersen conductivity is one of the main parameters in atmospheric electrodynamics, magnetosphere‐ionosphere‐thermosphere coupling, and several other geophysical processes. It is determined by the collision frequency between charged and neutral components and the Earth's magnetic field intensity through the gyrofrequency. This work analyzes the contribution of different ionic species to the variability of Pedersen conductance in time scales from hours to years within the period 1964–2008 based on the results of various atmospheric and ionospheric models. The main results are (1) there is a positive correlation between O+ density and Pedersen conductance, (2) Pedersen conductance of F layer has a larger increase with the solar activity than that of E layer, (3) Pedersen conductance has a long‐term trend that is determined by Earth's magnetic field intensity and electron density, and (4) at midlatitudes trends are mainly governed by the Earth's magnetic field and modulated by the electron density, while at high latitudes both are important.
Solar Cell Degradation Due to Proton Belt Enhancements During Electric Orbit Raising to GEO
Authors: Lozinski Alexander R. , Horne Richard B. , Glauert Sarah A. , Del Zanna Giulio , Heynderickx Daniel , Evans Hugh D. R. 
Published: June 2019

AbstractThe recent introduction of all‐electric propulsion on geosynchronous satellites enables lower‐cost access to space by replacing chemical propellant. However, the time period required to initially raise the satellite to geostationary orbit (GEO) is around 200 days. During this time the satellite can be exposed to dynamic increases in trapped flux, which are challenging to model. To understand the potential penalty of this new technique in terms of radiation exposure, the influence of several key parameters on solar cell degradation during the electric orbit raising period has been investigated. This is achieved by calculating the accumulation of nonionizing dose through time for a range of approaches. We demonstrate the changes in degradation caused by launching during a long‐lived (hundreds of days) enhancement in megaelectron volt trapped proton flux for three different electric orbit raising scenarios and three different thicknesses of coverglass. Results show that launching in an active environment can increase solar cell degradation due to trapped protons by ∼5% before start of service compared with a quiet environment. The crucial energy range for such enhancements in proton flux is 3–10 MeV (depending on shielding). Further changes of a few percent can occur between different trajectories, or when a 50‐μm change in coverglass thickness is applied.
ER complex proteins are required for rhodopsin biosynthesis and photoreceptor survival in Drosophila and mice
Authors: Xiong Liangyao , Zhang Lin , Yang Yeming , Li Na , Lai Wenjia , Wang Fengchao , Zhu Xianjun , Wang Tao 
Published: July 2019

AbstractDefective rhodopsin homeostasis is one of the major causes of retinal degeneration, including the disease Retinitis pigmentosa. To identify cellular factors required for the biosynthesis of rhodopsin, we performed a genome-wide genetic screen in Drosophila for mutants with reduced levels of rhodopsin. We isolated loss-of-function alleles in endoplasmic reticulum membrane protein complex 3 (emc3), emc5, and emc6, each of which exhibited defective phototransduction and photoreceptor cell degeneration. EMC3, EMC5, and EMC6 were essential for rhodopsin synthesis independent of the ER associated degradation (ERAD) pathway, which eliminates misfolded proteins. We generated null mutations for all EMC subunits, and further demonstrated that different EMC subunits play roles in different cellular functions. Conditional knockout of the Emc3 gene in mice led to mislocalization of rhodopsin protein and death of cone and rod photoreceptor cells. These data indicate conserved roles for EMC subunits in maintaining rhodopsin homeostasis and photoreceptor function, and suggest that retinal degeneration may also be caused by defects in early biosynthesis of rhodopsin.
Nrf2 drives oxidative stress-induced autophagy in nucleus pulposus cells via a Keap1/Nrf2/p62 feedback loop to protect intervertebral disc from degeneration
Authors: Tang Zehan , Hu Bo , Zang Fazhi , Wang Jianxi , Zhang Xingda , Chen Huajiang 
Published: July 2019

AbstractIntervertebral disc (IVD) degeneration is known to aggravate with age and oxidative stress is implicated in the pathogenesis of many age-related diseases. Nuclear factor (erythroid-derived-2)-like 2 (Nrf2) can confer adaptive protection against oxidative and proteotoxic stress in cells. In this study, we assessed whether Nrf2 can protect against oxidative stress in nucleus pulposus (NP) cells. In addition, we investigated Nrf2 expression in NP tissue samples from patients with different degrees of IVD degeneration and a mouse model of aging and IVD degeneration and the influence of H2O2-induced oxidative stress on autophagic pathways in NP cells. Autophagy was assessed by measuring levels of autophagy-related protein (ATG) family members and the autophagic markers, p62 and LC3. We found that expression of Nrf2 progressively decreased in human NP tissue samples of patients with increasing degrees of IVD degeneration. Nrf2 deficiency leads to the degeneration of IVDs during aging. Nrf2 knockout also aggravates IVD degeneration and reduces autophagic gene expression in an induced mouse model of IVD degeneration. The detrimental effects of H2O2-induced oxidative stress were increased in autophagy-deficient cells via reduced expression of Atg7 and the Keap1–Nrf2–p62 autophagy pathway. Taken together, these results suggest that excessive oxidative stress causes the upregulation of autophagy, and autophagy acts as an antioxidant feedback response activated by a Keap1-Nrf2-p62 feedback loop in IVD degeneration.
E1A oncogene induced sensitization to NK cell induced apoptosis requires PIDD and Caspase-2
Authors: Radke Jay R. , Routes John M. , Cook James L. 
Published: July 2019

AbstractExpression of the adenovirus E1A oncogene sensitizes tumor cells to innate immune rejection by NK cells. This increased NK sensitivity is only partly explained by an E1A-induced increase in target cell surface expression of NKG2D ligands. The post-recognition mechanisms by which E1A sensitizes cells to the apoptotic cell death response to NK injury remains to be defined. E1A sensitizes cells to apoptotic stimuli through two distinct mechanisms—repression of NF-κB-dependent antiapoptotic responses and enhancement of caspase-2 activation and related mitochondrial injury. The current studies examined the roles of each of these post-NKG2D-recognition pathways in the increased sensitivity of E1A-positive target cells to NK killing. Sensitization to NK-induced apoptosis was independent of E1A-mediated repression of cellular NF-κB responses but was dependent on the expression of both caspase-2 and the upstream, caspase-2 activating molecule, PIDD. Target cells lacking caspase-2 or PIDD expression retained E1A-induced increased expression of the NKG2D ligand, RAE-1. NK cell-induced mitochondrial injury of E1A-expressing cells did not require expression of the mitochondrial molecules, Bak or Bax. These results define a PIDD/caspase-2-dependent pathway, through which E1A sensitizes cells to NK-mediated cytolysis independently of and complementarily to E1A-enhanced NKG2D/RAE-1 ligand expression.
Structure and function of the Orc1 BAH-nucleosome complex
Authors: De Ioannes Pablo , Leon Victor A. , Kuang Zheng , Wang Miao , Boeke Jef D. , Hochwagen Andreas , Armache Karim-Jean 
Published: July 2019

AbstractThe Origin Recognition Complex (ORC) is essential for replication, heterochromatin formation, telomere maintenance and genome stability in eukaryotes. Here we present the structure of the yeast Orc1 BAH domain bound to the nucleosome core particle. Our data reveal that Orc1, unlike its close homolog Sir3 involved in gene silencing, does not appear to discriminate between acetylated and non-acetylated lysine 16, modification states of the histone H4 tail that specify open and closed chromatin respectively. We elucidate the mechanism for this unique feature of Orc1 and hypothesize that its ability to interact with nucleosomes regardless of K16 modification state enables it to perform critical functions in both hetero- and euchromatin. We also show that direct interactions with nucleosomes are essential for Orc1 to maintain the integrity of rDNA borders during meiosis, a process distinct and independent from its known roles in silencing and replication.
An ErbB2/c-Src axis links bioenergetics with PRC2 translation to drive epigenetic reprogramming and mammary tumorigenesis
Authors: Smith Harvey W. , Hirukawa Alison , Sanguin-Gendreau Virginie , Nandi Ipshita , Dufour Catherine R. , Zuo Dongmei , Tandoc Kristofferson , Leibovitch Matthew , Singh Salendra , Rennhack Jonathan P. , Swiatnicki Matthew , Lavoie Cynthia , Papavasiliou Vasilios , Temps Carolin , Carragher Neil O. , Unciti-Broceta Asier , Savage Paul , Basik Mark , van Hoef Vincent , Larsson Ola , Cooper Caroline L. , Vargas Calderon Ana Cristina , Beith Jane , Millar Ewan , Selinger Christina , Giguère Vincent , Park Morag , Harris Lyndsay N. , Varadan Vinay , Andrechek Eran R. , O’Toole Sandra A. , Topisirovic Ivan , Muller William J. 
Published: July 2019

AbstractDysregulation of histone modifications promotes carcinogenesis by altering transcription. Breast cancers frequently overexpress the histone methyltransferase EZH2, the catalytic subunit of Polycomb Repressor Complex 2 (PRC2). However, the role of EZH2 in this setting is unclear due to the context-dependent functions of PRC2 and the heterogeneity of breast cancer. Moreover, the mechanisms underlying PRC2 overexpression in cancer are obscure. Here, using multiple models of breast cancer driven by the oncogene ErbB2, we show that the tyrosine kinase c-Src links energy sufficiency with PRC2 overexpression via control of mRNA translation. By stimulating mitochondrial ATP production, c-Src suppresses energy stress, permitting sustained activation of the mammalian/mechanistic target of rapamycin complex 1 (mTORC1), which increases the translation of mRNAs encoding the PRC2 subunits Ezh2 and Suz12. We show that Ezh2 overexpression and activity are pivotal in ErbB2-mediated mammary tumourigenesis. These results reveal the hitherto unknown c-Src/mTORC1/PRC2 axis, which is essential for ErbB2-driven carcinogenesis.
Approaching coupled cluster accuracy with a general-purpose neural network potential through transfer learning
Authors: Smith Justin S. , Nebgen Benjamin T. , Zubatyuk Roman , Lubbers Nicholas , Devereux Christian , Barros Kipton , Tretiak Sergei , Isayev Olexandr , Roitberg Adrian E. 
Published: July 2019

AbstractComputational modeling of chemical and biological systems at atomic resolution is a crucial tool in the chemist’s toolset. The use of computer simulations requires a balance between cost and accuracy: quantum-mechanical methods provide high accuracy but are computationally expensive and scale poorly to large systems, while classical force fields are cheap and scalable, but lack transferability to new systems. Machine learning can be used to achieve the best of both approaches. Here we train a general-purpose neural network potential (ANI-1ccx) that approaches CCSD(T)/CBS accuracy on benchmarks for reaction thermochemistry, isomerization, and drug-like molecular torsions. This is achieved by training a network to DFT data then using transfer learning techniques to retrain on a dataset of gold standard QM calculations (CCSD(T)/CBS) that optimally spans chemical space. The resulting potential is broadly applicable to materials science, biology, and chemistry, and billions of times faster than CCSD(T)/CBS calculations.
Cathelicidin- derived PR39 protects enterohemorrhagic Escherichia coli O157:H7 challenged mice by improving epithelial function and balancing the microbiota in the intestine
Authors: Haiwen Zhang , Rui Hua , Bingxi Zhang , Qingfeng Guan , Beibei Wang , Jifeng Zeng , Xuemei Wang , Kebang Wu 
Published: July 2019

AbstractThe zoonotic enterohaemorrhagic Escherichia coli (EHEC) O157:H7 can disrupt intestinal epithelial barrier function and in turn leading to serious intestinal and systemic disease. PR39 could effectively inhibit the growth of Gram-negative bacteria, but there is little knowledge of its effects on intestinal barrier function and the microbiota in E. coli-challenged mice. In this study, an intestinal disease caused by EHEC O157:H7 was established, to analyze the effect of PR39 on EHEC O157:H7 induced intestinal epithelial barrier injury and disorder. Interestingly, PR39 attenuated EHEC O157:H7-induced systemic symptoms and significantly decreased mortality and the degree of E. coli shedding in faeces. Furthermore, the infiltration index of macrophages and neutrophils in intestine of the PR39 treatment group were obviously attenuated, along with the level of apoptosis. PR39 treatment group had distinctly improved tight junction associated proteins’ expression after EHEC O157:H7 caused injury. Additionally, the sequencing analysis of cecum microbiota showed that PR39 altered the abnormal increase in Bacteroides caused by EHEC O157:H7 and promoted the growth of probiotics such as Lactobacillus. In conclusion, cathelicidin-derived PR39 could effectively improve EHEC O157:H7-induced epithelial barrier injury, and dysfunction of immune and microbiota homeostasis in the intestinal tract, indicating that PR39 could be an excellent potential drug for zoonotic EHEC O157:H7-related intestinal disease.
Expression of neuropeptide Y is increased in an activated human HSC cell line
Authors: Dai Wufei , Liu Yang , Zhang Yali , Sun Yufeng , Sun Changjiang , Zhang Yu , Lv Xiufang 
Published: July 2019

AbstractNeuropeptide Y (NPY) is an abundant neuropeptide in the mammalian central and peripheral nervous systems. Transgenic mice overexpressing NPY in noradrenergic neurons have increased level of hepatic triglycerides, fatty acids and cholesterol, which contributed to the development of hepatosteatosis. However, the roles of NPY in the activation of hepatic stellate cells (HSCs) and the underlying mechanisms remain unclear. This study aimed to investigate the expression and secretion of NPY in human immortalized HSC LX-2 cells and the regulatory function of NPY on the fibrogenic response in LX-2 cells, to explore the potential association between NPY and LX-2 activation. The results showed an increase in the expression and secretion of NPY(1–36) in activated LX-2 cells. Both endogenous and exogenous NPY(1–36) induced the phosphorylation of mTOR, p70S6K, and 4EBP1 and promoted the fibrogenic response via NPY Y1 receptor subtype (NPY1R), as these responses were blocked by either an NPY1R antagonist (BIBP3226) or NPY1R knockdown. Moreover, NPY(1–36) serum levels were increased in patients with liver cirrhosis (LC) and hepatocellular carcinoma (HCC) and presented a positive relationship with MELD scores in LC patients. These findings suggest that immortalized HSCs LX-2 have the potential to produce NPY(1–36). High serum levels of NPY(1–36) is correlated with hepatic dysfunction in cirrhotic patients.
Associations between body mass index, waist circumference, waist-to-height ratio, and high blood pressure among adolescents: a cross-sectional study
Authors: Kuciene Renata , Dulskiene Virginija 
Published: July 2019

AbstractThe purpose of the present study was to examine the associations between body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and high blood pressure (HBP), and to determine which anthropometric parameters can best predict HBP among Lithuanian adolescents aged 12–15 years. Data from the survey of “Prevalence and Risk Factors of HBP in 12–15-Year-Old Lithuanian Children and Adolescents (Study 1, 2010–2012)” were used; a total of 7,457 respondents (3,494 boys and 3,963 girls) were included in this analysis. Adolescents with BP above the 90th percentile were measured on two different occasions. Logistic regression analysis was used to assess the associations and to calculate odds ratios. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of the three anthropometric parameters to predict HBP. The adjusted odds ratios (aOR) in the highest quartiles of BMI, WC, and WHtR were statistically significant for both sexes separately (reference group – the first quartile): in boys, prehypertension – 4.91, 4.09, and 1.59; hypertension – 7.96, 6.44, and 2.81; and prehypertension/hypertension – 6.85, 5.65, and 2.37, respectively; and in girls, prehypertension – 3.42, 2.70, and 1.66; hypertension – 5.71, 3.54, and 2.90; and prehypertension/hypertension – 4.62, 3.17, and 2.31, respectively). According to the analyses of the ROC curve, BMI z-score provided the largest area under the curve (AUC) value, followed by WC z-score, while WHtR z-score showed the lowest AUC value in predicting elevated BP in both sexes separately. Among Lithuanian adolescents aged 12–15 years, both anthropometric indices – BMI and WC (but particularly BMI) – showed stronger associations with HBP and were better for the prediction of HBP, compared to WHtR.
USP21 modulates Goosecoid function through deubiquitination
Authors: Liu Fuwei , Fu Qian , Li Yunpeng , Zhang Kai , Tang Mingyue , Jiang Wei , Bo Bin , Cui Yajun , Kong Liang 
Published: June 2019

AbstractThe homeobox gene Goosecoid (GSC), which is known to regulate craniofacial development, is activated by mono-ubiquitination; however, the deubiquitylase responsible for GSC deubiquitination and inhibition has yet to be identified. In the present study, we constructed the recombinant plasmid pFlag-CMV-2-GSC and the SRY (sex-determining region Y)-box 6 (Sox6) reporter gene system to identify deubiquitylases that regulate GSC expression. We demonstrate that the ubiquitin carboxyl-terminal hydrolase 21 (USP21) regulates the deubiquitination of GSC negatively, as demonstrated by its inhibition of Sox6 reporter gene transcription. USP21 interacted with GSC to promote GSC deubiquitination while having no effect on GSC protein stability. Cell viability, migration, and function in ATDC5 cells were probably influenced by USP21 through GSC. These findings suggest that USP21 modulates GSC function through deubiquitination.