bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defective Histone H3K27 Trimethylation Modification in Embryos Derived from Heated Mouse Sperm
Authors: Chao Shi-Bin , Chen Lei , Li Jian-Chun , Ou Xiang-Hong , Huang Xiao-Jin , Wen Shu , Sun Qing-Yuan , Gao Guo-Lan 
Published: May 2012

AbstractThe mouse sperm genome is resistant toin vitroheat treatment, and embryos derived from heated sperm can support full-term embryonic development, but the blastocyst rate and implantation rate are lower compared to embryos derived from fresh sperm. In the present study, the patterns of DNA methylation, histone H4K12 (ACH4K12) acetylation, H3K9 trimethylation (H3K9-TriM), and H3K27 trimethylation (H3K27-TriM) in preimplantation embryos derived from 65°C-heated sperm were investigated. Although no evident changes in global DNA methyaltion, histone H4K12 (ACH4K12) acetylation, and H3K9 trimethylation (H3K9-TriM) were found, significantly lower levels of H3K27-TriM, which was thought to be one of the reasons for low efficiency of mouse cloning, were found in the inner cell mass of heated-sperm derived blastocysts. Thus, defective modification of H3K27-TriM might contribute to compromised development of embryos derived from heated sperm.
Statistical ring current of Saturn
Authors: Carbary J. F. , Achilleos N. , Arridge C. S. 
Published: May 2012

The statistical ring current of Saturn has been determined from the curl of the median magnetic field derived from over 5 years of observations of the Cassini magnetometer. The main issue addressed here is the calculation of the statistical ring current of Saturn by directly computing, for the first time, the symmetrical part of the ring current J from the Maxwell equation ∇ × B = μ0J from assembling the perturbation magnetic field B from 2004 through 2010. This study validates previous studies, based on fewer data and not using ∇ × B, and shows that the ring current flows eastward (in the +ϕ or corotation direction) and extends from ∼3 RS to at least ∼20 RS (1 RS = 60,268 km), which is the vicinity of the dayside magnetopause; that the ring current has a peak strength of ∼75 pA/m2 at ∼9.5 RS; and that the ring current has a half‐width of ∼1.5 RS. Two outcomes of this study are that the ring current bends northward, as suggested by the “bowl” model of Saturn's plasma sheet, and that the total ring current is 9.2 ± 1.0 MA. In the context of future endeavors, the statistical ring current presented here can be used for calculations of the magnetic field of Saturn for particle drifts, field line mapping, and J × B force.
Does eddy‐eddy interaction control surface phytoplankton distribution and carbon export in the North Pacific Subtropical Gyre?
Authors: Guidi Lionel , Calil Paulo H. R. , Duhamel Solange , Björkman Karin M. , Doney Scott C. , Jackson George A. , Li Binglin , Church Matthew J. , Tozzi Sasha , Kolber Zbigniew S. , Richards Kelvin J. , Fong Allison A. , Letelier Ricardo M. , Gorsky Gabriel , Stemmann Lars , Karl David M. 
Published: May 2012

In the North Pacific Subtropical Gyre (NPSG), the regular occurrence of summer phytoplankton blooms contributes to marine ecosystem productivity and the annual carbon export. The mechanisms underlying the formation, maintenance, and decay of these blooms remain largely unknown; nitrogen fixation, episodic vertical mixing of nutrients, and meso‐ (<100 km) and submesoscale (<10 km) physical processes are all hypothesized to contribute to bloom dynamics. In addition, zones of convergence in the ocean's surface layers are known to generate downwelling and/or converging currents that affect plankton distributions. It has been difficult to quantify the importance of these convergence zones in the export flux of particulate organic carbon (POC) in the open ocean. Here we use two high‐resolution ocean transects across a pair of mesoscale eddies in the vicinity of Station ALOHA (22° 45′N, 158° 00′W) to show that horizontal turbulent stirring may have been a dominant control on the spatial distribution of the nitrogen fixing cyanobacteriumTrichodesmium spp. Fast repetition rate fluorometry measurements suggested that this distribution stimulated new primary production; this conclusion was not confirmed by 14C‐based measurements, possibly because of different sampling scales for the two methods. Our observations of particle size distributions along the two transects showed that stretching by the mesoscale eddy field produced submesoscale features that mediated POC export via frontogenetically generated downwelling currents. This study highlights the need to combine high‐resolution biogeochemical and physical data sets to understand the links betweenTrichodesmium spp. surface distribution and POC export in the NPSG at the submesoscale level.
Mitochondrial glutathione in toxicology and disease of the kidneys
Authors: Lash Lawrence H. 
Published: May 2012

AbstractThe tripeptide glutathione (GSH), comprised of the amino acids l-cysteine, glycine, and l-glutamate, is found in all cells of aerobic organisms and plays numerous, critical roles as an antioxidant and nucleophile in regulating cellular homeostasis and drug metabolism. GSH is synthesized exclusively in the cytoplasm of most cells by two ATP-dependent reactions. Despite this compartmentation, GSH is found in other subcellular compartments, including mitochondria. As the GSH molecule has a net negative charge at physiological pH, it cannot cross cellular membranes by diffusion. Rather, GSH is a substrate for a variety of anion and amino acid transporters. Two organic anion carriers in the inner membrane of renal mitochondria, the dicarboxylate carrier (DIC; Slc25a10) and the 2-oxoglutarate carrier (OGC; Slc25a11), are responsible for most of the transport of GSH from cytoplasm into mitochondrial matrix. Genetic manipulation of DIC and/or OGC expression in renal cell lines demonstrated the ability to produce sustained increases in mitochondrial GSH content, which then protected these cells from cytotoxicity due to several oxidants and mitochondrial toxicants. Several diseases and pathological states are associated with mitochondrial dysfunction and oxidative stress, suggesting that the mitochondrial GSH pool may be a therapeutic target. One such disease that is of particular concern for public health is diabetic nephropathy. Another chronic, pathological state that is associated with bioenergetic and redox changes is compensatory renal hypertrophy that results from reductions in functional renal mass. This review summarizes pathways of mitochondrial GSH transport and discusses studies on its manipulation in toxicological and pathological states.
Mechanotransduction in cells1
Authors: Goldmann Wolfgang H 
Published: May 2012

AbstractCell—matrix and cell—cell adhesions critically influence cell metabolism, protein synthesis, cell survival, cytoskeletal architecture and consequently cell mechanical properties such as migration, spreading and contraction. An important group of adhesive transmembrane receptors that mechanically link the ECM (extracellular matrix) with the internal cytoskeleton are integrins which are intimately connected with the FAs (focal adhesions) which consists of many proteins. The transient formation of FAs is greatly augmented either through externally applied tension to the cell or internally through myosin II‐driven cell contractility. Exactly which protein(s) within FAs sense, transmit and respond to mechanical stress is currently debated and numerous candidates have been proposed.
Enhancing nonvolatile write-once-read-many-times memory effects with SiO2 nanoparticles sandwiched by poly(N-vinylcarbazole) layers
Authors: Xia Xianhai , Liu Xiangmei , Yi Mingdong , Fan Quli , Wang Lianhui , Tai Qiang , Shi Weiwei , Xie Linghai , Huang Wei 
Published: May 2012

Abstract
A nonvolatile write-once-read-many-times (WORM) memory device based on the ITO/poly(N-vinylcarbazole) (PVK)/SiO2 nanoparticles (SiO2 NPs)/PVK/Al structure is demonstrated. By employing SiO2 NPs, the ON/OFF current ratio of the device is enlarged from 20 to 7 × 102 at a low voltage, and the device shows obvious negative differential resistance (NDR) phenomenon at a high electric field. Compared with the ITO/PVK/Al and ITO/PVK/PVK/Al devices, it is found that the size of the SiO2 NPs sandwiched between two PVK layers plays an important role in enhancing the reproducibility and the ON state retention time of the WORM memory device. The WORM memory mechanisms of the device are investigated on the basis of the current–voltage (I–V) characteristics and scanning electron microscopy image. Here, the strength of the NDR effect in our devices is only related to the charge defects and traps of PVK films, and it can be enlarged by embedding charge traps into the PVK films.
Study of phase transformation behaviour of alumina through precipitation method
Authors: Shen Lu , Hu Chunfeng , Sakka Yoshio , Huang Qing 
Published: May 2012

Abstract
Alumina hydrates were prepared by the wet chemical method under different pH values and subsequently calcined through both conventional and microwave heating approaches. After calcination at 500 °C for 2 h, amorphous precursor was partially transformed to α-alumina. NH4NO3 remaining in the dried precursor without further washing after precipitation reaction was found to increase the transformation temperature, which is different from previous published results. Microwave calcination was also employed and can dramatically enhance the phase transformation rate in comparison with the conventional method. A combination of microwave heating and amorphous precursor may be a viable strategy to fabricate α-alumina at low temperatures rapidly.
Structural depth profile and nanoscale piezoelectric properties of randomly oriented Pb(Zr0.50Ti0.50)O3 thin films
Authors: Lima E C , Araújo E B , Souza Filho A G , Paschoal A R , Bdikin I K , Kholkin A L 
Published: May 2012

Abstract
The structural properties of Pb(Zr0.50Ti0.50)O3 thin films with no preferential orientation were studied throughout the film thickness. An analysis on depth profile shows the existence of a significant (1 0 0) alignment near the film–electrode interface. Nanoscale piezoelectric measurements demonstrate the existence of a self-polarization effect in the studied films. An increase in this effect with film thickness increasing from 200 to 710 nm suggests that Schottky barriers and/or mechanical coupling near the film–electrode interface cannot be the main mechanisms responsible for the self-polarization effect in the studied films.
The Fifth Workshop on Stochasticity in Fusion Plasmas (Jülich, Germany, 11–14 April 2011)
Authors: Oliver Schmitz  
Published: May 2012

'Fusion meets chaotic dynamics'—this was the headline for the Fifth International Workshop on Stochasticity in Fusion Plasmas (SFP) held in Jülich, Germany from 11–14 April 2011. This headline reflects a landmark as the generic topic of chaotic dynamical systems has emerged a prominent application by controlling the plasma stability and transport. The workshop facilitated once more gathering of expertise from basic research in the field of non-linear dynamic systems and experts on plasma stability and transport from magnetically confined high temperature plasmas.
Resonant magnetic perturbations are used in most large-scale fusion experiments for control of the cyclic high heat flux pulses caused by edge-localized modes in high performance plasmas. This is one of the most prominent applications of non-linear perturbation schemes in modern plasma physics. It was experimentally shown that the edge transport in toroidal magnetic confinement systems as tokamaks and stellarators can be improved towards elimination of transient events, reduction of steady state heat flux densities and reduction of impurity inflow with improvement of the particle confinement. These results sketch the versatile application space of small-scale perturbations for optimization of the rigid magnetic cages used in magnetic confinement of fusion plasmas.
At the same time, these experimental observations represent a challenge to theory. The understanding of the experimental observations for extrapolation to future devices is a root requirement in this field of research. Two aspects were dominant in the workshop. First, the question of how the high temperature plasma as highly conductive media with potentially high rotation and plasma drift speeds reacts to a stationary external perturbation was central in all discussions on structural formation, related transport effects and interaction to plasma stability. Second, the topic was highlighted in how far the perturbed system and the final plasma stage is optimized in view of plasma–wall interaction.
The papers published in this special issue represent an overview of key aspects discussed at the workshop. This selection is a vital mixture taken out of the following four topical sessions: (1) Formation of stochastic magnetic layers and plasma response to external, non-axisymmetric magnetic perturbations; (2) Energy and particle transport in stochastic magnetic fields; (3) Exhaust in helical and island divertors; (4) Application of resonant magnetic perturbations for ELM control and implications for ITER. Each topical session was concluded with an appended discussion session. An overview of the key points identified in these discussion sessions is given in the workshop summary.
The next workshop is planned for early 2013. For details please see www.fz-juelich.de/sfp/. We hope this special issue of Nuclear Fusion will give a stimulating overview of the newest results in this field and highlights key aspects for application in next step fusion devices.
Screening of resonant magnetic perturbations by flows in tokamaks
Authors: Becoulet M. , Orain F. , Maget P. , Mellet N. , Garbet X. , Nardon E. , Huysmans G.T.A. , Casper T. , Loarte A. , Cahyna P. , Smolyakov A. , Waelbroeck F.L. , Schaffer M. , Evans T. , Liang Y. , Schmitz O. , Beurskens M. , Rozhansky V. , Kaveeva E. 
Published: May 2012

Abstract
The non-linear reduced four-field RMHD model in cylindrical geometry was extended to include plasma rotation, neoclassical poloidal viscosity and two fluid diamagnetic effects. Interaction of the static resonant magnetic perturbations (RMPs) with the rotating plasmas in tokamaks was studied. The self-consistent evolution of equilibrium electric field due to RMP penetration is taken into account in the model. It is demonstrated that in the pedestal region with steep pressure gradients, mean flows perpendicular to the magnetic field, which includes

and electron diamagnetic components plays an essential role in RMP screening by plasma. Generally, the screening effect increases for lower resistivity, stronger rotation and smaller RMP amplitude. Strong screening of central islands was observed limiting RMP penetration to the narrow region near the separatrix. However, at certain plasma parameters and due to the non-linear evolution of the radial electric field produced by RMPs, the

rotation can be compensated by electron diamagnetic rotation locally. In this case, RMPs can penetrate and form magnetic islands. Typical plasma parameters and RMPs spectra on DIII-D, JET and ITER were used in modelling examples presented in the paper.
First use of three-dimensional equilibrium, stability and transport calculations for interpretation of ELM triggering with magnetic perturbations in NSTX
Authors: Canik J.M. , Hirshman S.P. , Sanchez R. , Maingi R. , Ahn J.-W. , Bell R.E. , Diallo A. , Gerhardt S.P. , LeBlanc B.P. , Menard J.E. , Park J.-K. , Podesta M. , Sabbagh S.A. 
Published: May 2012

Abstract
The application of non-axisymmetric magnetic perturbations has been demonstrated to destabilize edge-localized modes (ELMs) in the National Spherical Torus Experiment. A model 3D equilibrium has been calculated for these experiments using the VMEC code, which assumes nested flux surfaces and therefore that resonant perturbations are shielded. First, a free-boundary equilibrium is calculated using the NSTX coil set, with pressure and current profiles matched to a standard 2D reconstruction, but with up–down symmetry enforced. A new equilibrium is then calculated with the n = 3 field applied at a level consistent with experiment. This equilibrium is then used as the basis of further calculations using codes developed for analysis of stellarator plasmas. The neoclassical transport due to the 3D fields is calculated to be small compared with the experimental transport rates. Initial stability analysis has been performed, and indicates a modest degradation in ballooning stability with 3D fields applied. A new 3D equilibrium is also calculated using the SIESTA code, which allows for the formation of islands and stochastic regions. A comparison of the field structure between the SIESTA calculation and the assumption of fully penetrated vacuum perturbation indicates smaller island sizes and very small stochastic transport in the SIESTA case.
Modifying locally the safety profile to improve the confinement of magnetic field lines in tokamak plasmas
Authors: Constantinescu D. , Firpo M.-C. 
Published: May 2012

Abstract
Using Hamiltonian models for the magnetic field lines, we propose a methodology to improve their confinement through the creation of transport barriers. A local modification of the safety profile creating a low-shear zone is shown to be sufficient to locally enhance drastically the regularity of the magnetic field lines without requesting a reversed shear. The optimal benefits of low-shear are obtained when the value q
0 of the safety profile in the low-shear zone is sufficiently far from the main resonance values m/n with low m and n, in the case of large enough values of those (m, n) mode amplitudes. A practical implementation in tokamak plasmas should involve electron cyclotron current drive to locally modify the magnetic shear.
Analysis of stochastic magnetic fields formed by the application of resonant magnetic perturbations on MAST and comparison with experiment
Authors: Denner P. , Liu Yueqiang , Nardon E. , Kirk A. 
Published: May 2012

Abstract
In MAST experiments with applied resonant magnetic perturbations (RMPs), clear reduction in line-averaged density has been observed in a wide range of L-mode plasmas when there is an alignment between the perturbation and the equilibrium magnetic field that maximizes the size of the resonant components of the applied magnetic field, as well as in a few H-mode plasmas but with a much stronger sensitivity to this alignment. This density pump-out is the result of increased particle transport, which is thought to be caused by the formation of a stochastic magnetic field in the plasma edge. This paper presents an analysis of the magnetic field structures formed by the application of n = 3 RMPs on MAST, including various parameters characterizing the degree of stochasticity in the plasma edge. Values for these parameters are calculated and compared with the amount of density pump-out observed in MAST experiments. It is found that density pump-out is fairly well correlated with some of the parameters calculated using vacuum modelling, but none of them provides a single threshold value for pump-out that applies to both L- and H-mode plasmas. Plasma response modelling provides a robust criterion for density pump-out that applies both to L- and H-mode plasmas.
Strike point splitting in the heat and particle flux profiles compared with the edge magnetic topology in a n = 2 resonant magnetic perturbation field at JET
Authors: Harting D.M. , Liang Y. , Jachmich S. , Koslowski R. , Arnoux G. , Devaux S. , Eich T. , Nardon E. , Reiter D. , Thomsen H. 
Published: May 2012

At JET the error field correction coils can be used to generate an n = 1 or n = 2 magnetic perturbation field (Liang et al 2007 Plasma Phys. Control. Fusion
49 B581). Various experiments at JET have already been carried out to investigate the mitigation of ELMs by resonant magnetic perturbations (RMPs) (Liang et al 2010 Nucl. Fusion
50 025013, Liang et al 2011 Nucl. Fusion
51 073001). However, the typical formation of a secondary strike point (strike point splitting) by RMPs observed in other machines (Jakubowski et al 2010 Contrib. Plasma Phys.
50 701–7, Jakubowski et al 2004 Nucl. Fusion
44 S1–11, Nardon et al 2011 J. Nucl. Mater.

415 S914–7, Eich et al 2003 Phys. Rev. Lett.
91 195003, Evans et al 2007 J. Nucl. Mater.
363–365 570–4, Evans et al 2005 J. Phys.: Conf. Ser.
7 174–90, Watkins et al 2009 J. Nucl. Mater.
390–391 839–42) has never been observed at JET before. In this work we will present discharges where for the first time a strike point splitting by RMPs at JET has been observed. We will show that in these particular cases the strike point splitting matches the vacuum edge magnetic field topology. This is done by comparing heat and particle flux profiles on the outer divertor plate with the magnetic footprint pattern obtained by field line tracing. Further the evolution of the strike point splitting during the ramp up phase of the perturbation field and during a q
95-scan is investigated, and it will be shown that the spontaneous appearance of the strike point splitting is only related to some geometrical effects of the toroidal asymmetric magnetic topology.
First EMC3-Eirene simulations of the impact of the edge magnetic perturbations at ASDEX Upgrade compared with the experiment
Authors: Lunt T. , Feng Y. , Bernert M. , Herrmann A. , de Marné P. , McDermott R. , Müller H.W. , Potzel S. , Pütterich T. , Rathgeber S. , Suttrop W. , Viezzer E. , Wolfrum E. , Willensdorfer M. 
Published: May 2012

Abstract
The EMC3-Eirene code package was applied for the first time to simulate the edge plasma in an ASDEX Upgrade discharge, in which the newly installed magnetic perturbation (MP) coils were used to mitigate edge-localized modes (ELMs). Two different points in time during this discharge were simulated, the ELM-mitigated phase after turning-on of the MP coils and, as a reference, the ELMy H-mode phase before. The results were compared with the measurements of various edge and divertor diagnostics. Assuming the main chamber profiles to be shifted by 15 mm with respect to their calibrated positions, an agreement within a factor of 2 was found between the main chamber profiles outside the separatrix and those at the outer divertor target. The most important result is the observation of several maxima and minima in the particle flux and in particular in the power deposition pattern of both the simulation and the experiment for the case with MPs, an effect also known as strike-point splitting.