bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hepatocyte Nuclear Factor 1A Is a Cell-Intrinsic Transcription Factor Required for B Cell Differentiation and Development in Mice
Authors: von Wnuck Lipinski Karin , Sattler Katherine , Peters Susann , Weske Sarah , Keul Petra , Klump Hannes , Heusch Gerd , Göthert Joachim R. , Levkau Bodo 
Published: January 2016

Abstract
The hepatocyte NF (HNF) family of transcription factors regulates the complex gene networks involved in lipid, carbohydrate, and protein metabolism. In humans, HNF1A mutations cause maturity onset of diabetes in the young type 3, whereas murine HNF6 participates in fetal liver B lymphopoiesis. In this study, we have identified a crucial role for the prototypical member of the family HNF1A in adult bone marrow B lymphopoiesis. HNF1A−/− mice exhibited a clear reduction in total blood and splenic B cells and a further pronounced one in transitional B cells. In HNF1A−/− bone marrow, all B cell progenitors—from pre-pro–/early pro–B cells to immature B cells—were dramatically reduced and their proliferation rate suppressed. IL-7 administration in vivo failed to boost B cell development in HNF1A−/− mice, whereas IL-7 stimulation of HNF1A−/− B cell progenitors in vitro revealed a marked impairment in STAT5 phosphorylation. The B cell differentiation potential of HNF1A−/− common lymphoid progenitors was severely impaired in vitro, and the expression of the B lymphopoiesis-promoting transcription factors E2A, EBF1, Pax5, and Bach2 was reduced in B cell progenitors in vivo. HNF1A−/− bone marrow chimera featured a dramatic defect in B lymphopoiesis recapitulating that of global HNF1A deficiency. The HNF1A−/− lymphopoiesis defect was confined to B cells as T lymphopoiesis was unaffected, and bone marrow common lymphoid progenitors and hematopoietic stem cells were even increased. Our data demonstrate that HNF1A is an important cell-intrinsic transcription factor in adult B lymphopoiesis and suggest the IL-7R/STAT5 module to be causally involved in mediating its function.
Differential Effects of Escherichia coli Nissle and Lactobacillus rhamnosus Strain GG on Human Rotavirus Binding, Infection, and B Cell Immunity
Authors: Kandasamy Sukumar , Vlasova Anastasia N. , Fischer David , Kumar Anand , Chattha Kuldeep S. , Rauf Abdul , Shao Lulu , Langel Stephanie N. , Rajashekara Gireesh , Saif Linda J. 
Published: January 2016

Abstract
Rotavirus (RV) causes significant morbidity and mortality in children worldwide. The intestinal microbiota plays an important role in modulating host–pathogen interactions, but little is known about the impact of commonly used probiotics on human RV (HRV) infection. In this study, we compared the immunomodulatory effects of Gram-positive (Lactobacillus rhamnosus strain GG [LGG]) and Gram-negative (Escherichia coli Nissle [EcN]) probiotic bacteria on virulent human rotavirus (VirHRV) infection and immunity using neonatal gnotobiotic piglets. Gnotobiotic piglets were colonized with EcN, LGG, or EcN+LGG or uncolonized and challenged with VirHRV. Mean peak virus shedding titers and mean cumulative fecal scores were significantly lower in EcN-colonized compared with LGG-colonized or uncolonized piglets. Reduced viral shedding titers were correlated with significantly reduced small intestinal HRV IgA Ab responses in EcN-colonized compared with uncolonized piglets post-VirHRV challenge. However the total IgA levels post-VirHRV challenge in the intestine and pre-VirHRV challenge in serum were significantly higher in EcN-colonized than in LGG-colonized piglets. In vitro treatment of mononuclear cells with these probiotics demonstrated that EcN, but not LGG, induced IL-6, IL-10, and IgA, with the latter partially dependent on IL-10. However, addition of exogenous recombinant porcine IL-10 + IL-6 to mononuclear cells cocultured with LGG significantly enhanced IgA responses. The greater effectiveness of EcN in moderating HRV infection may also be explained by the binding of EcN but not LGG to Wa HRV particles or HRV 2/4/6 virus-like particles but not 2/6 virus-like particles. Results suggest that EcN and LGG differentially modulate RV infection and B cell responses.
Reassessing the Evolutionary Importance of Inflammasomes
Authors: Maltez Vivien I. , Miao Edward A. 
Published: January 2016

Abstract
Inflammasomes monitor the cytosol for microbial contamination or perturbation and, thus, are predicted to provide potent defense against infection. However, the compendium of data from murine infection models suggests that inflammasomes merely delay the course of disease, allowing the host time to mount an adaptive response. Interpretations of such results are confounded by inflammasome-evasion strategies of vertebrate-adapted pathogens. Conversely, environmental opportunistic pathogens have not evolved in the context of inflammasomes and, therefore, are less likely to evade them. Indeed, opportunistic pathogens do not normally cause disease in wild-type animals. Accordantly, the extreme virulence of two opportunistic bacterial pathogens, Burkholderia thailandensis and Chromobacterium violaceum, is fully counteracted by inflammasomes in murine models. This leads us to propose a new hypothesis: perhaps animals maintain inflammasomes over evolutionary time not to defend against vertebrate-adapted pathogens but instead to counteract infection by a plethora of undiscovered opportunistic pathogens residing in the environment.
Human Endothelial Cell Activation by Escherichia coli and Staphylococcus aureus Is Mediated by TNF and IL-1β Secondarily to Activation of C5 and CD14 in Whole Blood
Authors: Nymo Stig , Gustavsen Alice , Nilsson Per H. , Lau Corinna , Espevik Terje , Mollnes Tom Eirik 
Published: January 2016

Abstract
Endothelial cells (EC) play a central role in inflammation. E-selectin and ICAM-1 expression are essential for leukocyte recruitment and are good markers of EC activation. Most studies of EC activation are done in vitro using isolated mediators. The aim of the present study was to examine the relative importance of pattern recognition systems and downstream mediators in bacteria-induced EC activation in a physiological relevant human model, using EC incubated with whole blood. HUVEC were incubated with human whole blood. Escherichia coli– and Staphylococcus aureus–induced EC activation was measured by E-selectin and ICAM-1 expression using flow cytometry. The mAb 18D11 was used to neutralize CD14, and the lipid A analog eritoran was used to block TLR4/MD2. C5 cleavage was inhibited using eculizumab, and C5aR1 was blocked by an antagonist. Infliximab and canakinumab were used to neutralize TNF and IL-1β. The EC were minimally activated when bacteria were incubated in serum, whereas a substantial EC activation was seen when the bacteria were incubated in whole blood. E. coli–induced activation was largely CD14-dependent, whereas S. aureus mainly caused a C5aR1-mediated response. Combined CD14 and C5 inhibition reduced E-selectin and ICAM-1 expression by 96 and 98% for E. coli and by 70 and 75% for S. aureus. Finally, the EC activation by both bacteria was completely abolished by combined inhibition of TNF and IL-1β. E. coli and S. aureus activated EC in a CD14- and C5-dependent manner with subsequent leukocyte secretion of TNF and IL-1β mediating the effect.
Degranulating Neutrophils Promote Leukotriene B4 Production by Infected Macrophages To Kill Leishmania amazonensis Parasites
Authors: Tavares Natália , Afonso Lilian , Suarez Martha , Ampuero Mariana , Prates Deboraci Brito , Araújo-Santos Théo , Barral-Netto Manoel , DosReis George A. , Borges Valéria Matos , Brodskyn Cláudia 
Published: January 2016

Abstract
Neutrophils mediate early responses against pathogens, and they become activated during endothelial transmigration toward the inflammatory site. In the current study, human neutrophils were activated in vitro with immobilized extracellular matrix proteins, such as fibronectin (FN), collagen, and laminin. Neutrophil activation by FN, but not other extracellular matrix proteins, induces the release of the granules’ contents, measured as matrix metalloproteinase 9 and neutrophil elastase activity in culture supernatant, as well as reactive oxygen species production. Upon contact with Leishmania amazonensis–infected macrophages, these FN-activated neutrophils reduce the parasite burden through a mechanism independent of cell contact. The release of granule proteases, such as myeloperoxidase, neutrophil elastase, and matrix metalloproteinase 9, activates macrophages through TLRs, leading to the production of inflammatory mediators, TNF-α and leukotriene B4 (LTB4), which are involved in parasite killing by infected macrophages. The pharmacological inhibition of degranulation reverted this effect, abolishing LTB4 and TNF production. Together, these results suggest that FN-driven degranulation of neutrophils induces the production of LTB4 and TNF by infected macrophages, leading to the control of Leishmania infection.
Determination of heavy metals concentration in raw sheep milk from mercury polluted area
Authors: Stanovič Radovan , Árvay Július , Hauptvogl Martin , Tomáš Ján , Kováčik Anton , Záhorcová Zuzana , Slávik Marek 
Published: January 2016

The paper focuses on determining the content of monitored contaminants (Cd, Cu, Hg, Pb and Zn) in 53 samples of raw sheep milk collected in 2013 and 2014 on the sites Poráč and Matejovce nad Hornádom (middle Spiš). The area is characterized by historical mining and metalworking activity (mining and processing of polymetallic ores rich in Hg, Cd and Pb). Currently, the area is one of the most mercury contaminated areas in Central Europe. All statistical analyses were carried out using the statistical software Statistica 10.0 (Statsoft, USA). Descriptive data analysis included minimum value, maximum value, arithmetic mean and standard deviation. The results of the studied contaminant content show that the limit value for cadmium (10 μg.kg-1) was exceeded in 25 samples. In the case of lead, the limit value of 20 μg.kg-1 was exceeded in 16 cases. The limit value for copper (0.4 mg.kg-1) was exceeded in one case. The limit value for zinc is not defined by a legislative standard. The risk level of the studied contaminants in the samples of raw sheep milk decreases as follows: Cd > Pb > Hg > Cu > Zn. It can be concluded that frequent and long-term consumption of the raw sheep milk originating from the studied sites poses a health risk. The content of the contaminants in the milk and their eventual transition into dairy products should be monitored over a longer term in more detail.
Analyzing the Linkage between Agricultural Exports and Agriculture’s Share of Gross Domestic Products in South Africa
Authors: Bulagi Mushoni B. , Hlongwane Jan J. , Belete Abenet 
Published: January 2016

The paper analyses the link between avocado, apple, mango and orange exports and agriculture’s share of Gross Domestic Product in South Africa. The study used secondary time series data that covered a sample size of 20 years (1994 - 2014) of avocado, apple, mango and orange exports in South Africa. Two Stages Least Square models were used for data analysis. Empirical results for agricultural exports equation revealed that agricultural economic growth in South Africa was significant with a positive coefficient. Also a negative relationship between the Net Factor Income (NFI) and the agricultural exports in South Africa was noticed. Real Capital Investments had a significant positive coefficient. Consequently, results from agricultural economic growth equation revealed that agricultural exports were significant with a positive correlation. A relationship between NFI and agricultural GDP was also witnessed. Like other variables, Real Capital Investment was significant but negatively correlated.
Characterization of differential pore‐forming activities of ESAT‐6 proteins from Mycobacterium tuberculosis and Mycobacterium smegmatis
Authors: Peng Xiuli , Jiang Guozhong , Liu Wei , Zhang Qi , Qian Wei , Sun Jianjun 
Published: January 2016

Mycobacterium tuberculosis ESAT‐6 (MtbESAT‐6) plays essential roles in pathogenesis. MtbESAT‐6 exhibits a unique pore‐forming activity (PFA) that is not found in its ortholog from non‐pathogenic Mycobacterium smegmatis (MsESAT‐6). Here, we characterized the differential PFAs and found that exchange of I25‐H26/T25‐A26 between two proteins reciprocally affected their PFAs. MtbESAT‐6(IH/TA) had ~ 40% reduction, while MsESAT‐6(TA/IH) fully acquired its activity similar to MtbESAT‐6. Mutations of A17E, K38T, N67L or R74Q on MtbESAT‐6(IH/TA) further reduced the activity, with MtbESAT‐6(IH/TA‐17) being the lowest. This study suggests I25‐H26 as the pH‐sensor essential for MsESAT‐6 to fully acquire the activity, while multiple residues contributed to MtbESAT‐6 PFA.
A new kinematic model of the Mid‐Atlantic Ridge between 55°55'N and the Bight Transform Fault for the past 6 Ma
Authors: Benediktsdóttir Á. , Hey R. , Martinez F. , Höskuldsson Á. 
Published: January 2016

AbstractWe present a new fine‐scaled tectonic model of the Mid‐Atlantic Ridge between 55°55'N and the Bight Transform Fault for the past 6 Ma. We model our new marine magnetic data, providing a robust kinematic model for the area. The new model uses propagating rifts to explain observed asymmetry in high‐resolution marine magnetic data. The area closest to the Bight Transform Fault has undergone two relatively large (9 km and 6 km) relocations of the spreading center within the past 1 Ma, which explains the divided central anomaly; we attribute this relocation to two very fast propagations. The amount of lithosphere transferred between the plates during each propagation event is 2–10 km, and the propagators identified are short‐lived (0.5–4.0 Ma). Most of the propagation in the area is to the north, and all but two propagators transfer lithosphere from the Eurasian plate to the North American plate, which is consistent with the overall eastward relocation of the Reykjanes Ridge.
An evaluation of gas transfer velocity parameterizations during natural convection using DNS
Authors: Fredriksson Sam T. , Arneborg Lars , Nilsson Håkan , Zhang Qi , Handler Robert A. 
Published: January 2016

AbstractDirect numerical simulations (DNS) of free surface flows driven by natural convection are used to evaluate different methods of estimating air‐water gas exchange at no‐wind conditions. These methods estimate the transfer velocity as a function of either the horizontal flow divergence at the surface, the turbulent kinetic energy dissipation beneath the surface, the heat flux through the surface, or the wind speed above the surface. The gas transfer is modeled via a passive scalar. The Schmidt number dependence is studied for Schmidt numbers of 7, 150 and 600. The methods using divergence, dissipation and heat flux estimate the transfer velocity well for a range of varying surface heat flux values, and domain depths. The two evaluated empirical methods using wind (in the limit of no wind) give reasonable estimates of the transfer velocity, depending however on the surface heat flux and surfactant saturation. The transfer velocity is shown to be well represented by the expression,
, where
is a constant,
is the buoyancy flux,
is the kinematic viscosity,
is the Schmidt number, and the exponent
depends on the water surface characteristics. The results suggest that
and
and
for slip and no‐slip boundary conditions at the surface, respectively. It is further shown that slip and no‐slip boundary conditions predict the heat transfer velocity corresponding to the limits of clean and highly surfactant contaminated surfaces, respectively.
Impact of atmospheric convectively coupled equatorial Kelvin waves on upper ocean variability
Authors: Baranowski Dariusz B. , Flatau Maria K. , Flatau Piotr J. , Matthews Adrian J. 
Published: January 2016

AbstractConvectively coupled Kelvin waves (CCKWs) are atmospheric weather systems that propagate eastward along the equatorial wave guide with phase speeds between 11 and 14 m s−1. They are an important constituent of the convective envelope of the Madden‐Julian oscillation (MJO), for which ocean‐atmosphere interactions play a vital role. Hence, ocean‐atmosphere interactions within CCKWs may be important for MJO development and prediction and for tropical climate, in general. Although the atmospheric structure of CCKWs has been well studied, their impact on the underlying ocean is unknown. In this paper, the ocean‐atmosphere interactions in CCKWs are investigated by a case study from November 2011 during the CINDY/DYNAMO field experiment, using in situ oceanographic measurements from an ocean glider. The analysis is then extended to a 15 year period using precipitation data from the Tropical Rainfall Measuring Mission and surface fluxes from the TropFlux analysis. A methodology is developed to calculate trajectories of CCKWs. CCKW events are strongly controlled by the MJO, with twice as many CCKWs observed during the convectively active phase of the MJO compared to the suppressed phase. Coherent ocean‐atmosphere interaction is observed during the passage of a CCKW, which lasts approximately 4 days at any given longitude. Surface wind speed and latent heat flux are enhanced, leading to a transient suppression of the diurnal cycle of sea surface temperature (SST) and a sustained decrease in bulk SST of 0.1°C. Given that a typical composite mean MJO SST anomaly is of the order of 0.3°C, and more than one CCKW can occur during the active phase of a single MJO event, the oceanographic impact of CCKWs is of major importance to the MJO cycle.
Quantification of relative contribution of Antarctic ozone depletion to increased austral extratropical precipitation during 1979–2013
Authors: Bai Kaixu , Chang Ni‐Bin , Gao Wei 
Published: January 2016

AbstractAttributing the observed climate changes to relevant forcing factors is critical to predicting future climate change scenarios. Precipitation observations in the Southern Hemisphere indicate an apparent moistening pattern over the extratropics during the time period 1979 to 2013. To investigate the predominant forcing factor in triggering such an observed wetting climate pattern, precipitation responses to four climatic forcing factors, including Antarctic ozone, water vapor, sea surface temperature (SST), and carbon dioxide, were assessed quantitatively in sequence through an inductive approach. Coupled time‐space patterns between the observed austral extratropical precipitation and each climatic forcing factor were firstly diagnosed by using the maximum covariance analysis (MCA). With the derived time series from each coupled MCA modes, statistical relationships were established between extratropical precipitation variations and each climatic forcing factor by using the extreme learning machine. Based on these established statistical relationships, sensitivity tests were conducted to estimate precipitation responses to each climatic forcing factor quantitatively. Quantified differential contribution with respect to those climatic forcing factors may explain why the observed austral extratropical moistening pattern is primarily driven by the Antarctic ozone depletion, while mildly modulated by the cooling effect of equatorial Pacific SST and the increased greenhouse gases, respectively.
Litter dominates surface fluxes of carbonyl sulfide in a Californian oak woodland
Authors: Sun Wu , Maseyk Kadmiel , Lett Céline , Seibt Ulli 
Published: January 2016

AbstractCarbonyl sulfide (COS) is a promising tracer for partitioning terrestrial photosynthesis and respiration from net carbon fluxes, based on its daytime co‐uptake alongside CO2 through leaf stomata. Because ecosystem COS fluxes are the sum of plant and soil fluxes, using COS as a photosynthesis tracer requires accurate knowledge of soil COS fluxes. At an oak woodland in Southern California, we monitored below‐canopy surface (soil + litter) COS and CO2 fluxes for 40 days using chambers and laser spectroscopy. We also measured litter fluxes separately and used a depth‐resolved diffusion‐reaction model to quantify the role of litter uptake in surface COS fluxes. Soil and litter were primarily COS sinks, and mean surface COS uptake was small (∼1 pmol m−2 s−1). After rainfall, uptake rates were higher (6–8 pmol m−2 s−1), and litter contributed a significant fraction (up to 90%) to surface fluxes. We observed rapid concurrent increases in COS uptake and CO2 efflux following the onset of rain. The patterns were similar to the Birch effect widely documented for soils; however, both COS and CO2 flux increases originated mainly in the litter. The synchronous COS‐CO2 litter Birch effect indicates that it results from a rapid increase in litter microbial activity after rainfall. We expect that the drying‐rewetting cycles typical for mediterranean and other semiarid ecosystems create a pronounced seasonality in surface COS fluxes. Our results highlight that litter uptake is an important component of surface COS exchange that needs to be taken into account in ecosystem COS budgets and model simulations.
GEM‐CEDAR challenge: Poynting flux at DMSP and modeled Joule heat
Authors: Rastätter Lutz , Shim Ja Soon , Kuznetsova Maria M. , Kilcommons Liam M. , Knipp Delores J. , Codrescu Mihail , Fuller‐Rowell Tim , Emery Barbara , Weimer Daniel R. , Cosgrove Russell , Wiltberger Michael , Raeder Joachim , Li Wenhui , Tóth Gábor , Welling Daniel 
Published: January 2016

AbstractPoynting flux into the ionosphere measures the electromagnetic energy coming from the magnetosphere. This energy flux can vary greatly between quiet times and geomagnetic active times. As part of the Geospace Environment Modeling‐coupling energetics and dynamics of atmospheric regions modeling challenge, physics‐based models of the 3‐D ionosphere and ionospheric electrodynamics solvers of magnetosphere models that specify Joule heat and empirical models specifying Poynting flux were run for six geomagnetic storm events of varying intensity. We compared model results with Poynting flux values along the DMSP‐15 satellite track computed from ion drift meter and magnetic field observations. Although being a different quantity, Joule heat can in practice be correlated to incoming Poynting flux because the energy is dissipated primarily in high latitudes where Poynting flux is being deposited. Within the physics‐based model group, we find mixed results with some models overestimating Joule heat and some models agreeing better with observed Poynting flux rates as integrated over auroral passes. In contrast, empirical models tend to underestimate integrated Poynting flux values. Modeled Joule heat or Poynting flux patterns often resemble the observed Poynting flux patterns on a large scale, but amplitudes can differ by a factor of 2 or larger due to the highly localized nature of observed Poynting flux deposition that is not captured by the models. In addition, the positioning of modeled patterns appear to be randomly shifted against the observed Poynting flux energy input. This study is the first to compare Poynting flux and Joule heat in a large variety of models of the ionosphere.
Planar‐Chiral Cyclopentadienyl‐Ruthenium‐Catalyzed Regio‐ and Enantioselective Asymmetric Allylic Alkylation of Silyl Enolates under Unusually Mild Conditions
Authors: Kanbayashi Naoya , Yamazawa Arisa , Takii Koichiro , Okamura Taka‐aki , Onitsuka Kiyotaka 
Published: January 2016

AbstractWe report the asymmetric allylic alkylation of allylic chlorides with silyl enolates as a carbon nucleophile using a planar‐chiral cyclopentadienyl‐ruthenium (Cp′Ru) catalyst. The reaction proceeds under unusually mild conditions to give the desired branched products with complete regioselectivity and high enantioselectivity, and reactive functional groups, such as aldehyde, can be tolerated. In this reaction system, Cp′Ru plays an important role in activating both silyl enolate and allylic chloride.magnified image