bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvable points on genus-one curves over local fields
Authors: Pál Ambrus 
Published: May 2012

AbstractLet $F$ be a field complete with respect to a discrete valuation whose residue field is perfect of characteristic $p\gt 0$. We prove that every smooth, projective, geometrically irreducible curve of genus one defined over $F$ with a non-zero divisor of degree a power of $p$ has a solvable point over $F$.
A new approach to the Koszul property in representation theory using graded subalgebras
Authors: Parshall Brian J. , Scott Leonard L. 
Published: May 2012

AbstractGiven a quasi-hereditary algebra $B$, we present conditions which guarantee that the algebra $\mathrm{gr} \hspace{0.167em} B$ obtained by grading $B$ by its radical filtration is Koszul and at the same time inherits the quasi-hereditary property and other good Lie-theoretic properties that $B$ might possess. The method involves working with a pair $(A, \mathfrak{a})$ consisting of a quasi-hereditary algebra $A$ and a (positively) graded subalgebra $\mathfrak{a}$. The algebra $B$ arises as a quotient $B= A/ J$ of $A$ by a defining ideal $J$ of $A$. Along the way, we also show that the standard (Weyl) modules for $B$ have a structure as graded modules for $\mathfrak{a}$. These results are applied to obtain new information about the finite dimensional algebras (e.g., the $q$-Schur algebras) which arise as quotients of quantum enveloping algebras. Further applications, perhaps the most penetrating, yield results for the finite dimensional algebras associated with semisimple algebraic groups in positive characteristic $p$. These results require, at least at present, considerable restrictions on the size of $p$.
Propagation of medium scale traveling ionospheric disturbances at different latitudes and solar cycle conditions
Authors: Hernández‐Pajares M. , Juan J. M. , Sanz J. , Aragón‐Àngel A. 
Published: May 2012

In this work, an extension in latitude range and time span with respect previous studies on Medium Scale Traveling Ionospheric Disturbances (MSTID) propagation, is presented. So far they have been basically studied at mid latitude and for limited periods (less than few years) at solar maximum conditions. This extension has been possible due to the availability of local Global Positioning System (GPS) networks at mid‐north hemisphere (California), mid‐south hemisphere (New Zealand), high and low latitudes (Alaska and Hawaii), for the last 13, 11, 7 and 4 years respectively. Optimal algorithms specially suitable for mass data processing have been used, such as the Single Receiver Medium Scale Traveling Ionospheric activity index (SRMTID) and the phase difference method for MSTID propagation estimation. The results reveal that several of the main MSTID climatological trends at mid latitude are also shared at low and high latitude, also modulated in intensity also by the Solar Cycle. This is the case for local fall/winter day‐time equatorward propagated MSTIDs with typical velocities and wavelengths of 150–250 m/s and 100–300 km respectively. Moreover the comparison of MSTID propagation estimation using different techniques, and their implications in terms of potential origins of MSTIDs, are also discussed.
Lunar pickup ions observed by ARTEMIS: Spatial and temporal distribution and constraints on species and source locations
Authors: Halekas J. S. , Poppe A. R. , Delory G. T. , Sarantos M. , Farrell W. M. , Angelopoulos V. , McFadden J. P. 
Published: May 2012

ARTEMIS observes pickup ions around the Moon, at distances of up to 20,000 km from the surface. The observed ions form a plume with a narrow spatial and angular extent, generally seen in a single energy/angle bin of the ESA instrument. Though ARTEMIS has no mass resolution capability, we can utilize the analytically describable characteristics of pickup ion trajectories to constrain the possible ion masses that can reach the spacecraft at the observation location in the correct energy/angle bin. We find that most of the observations are consistent with a mass range of ∼20–45 amu, with a smaller fraction consistent with higher masses, and very few consistent with masses below ∼15 amu. With the assumption that the highest fluxes of pickup ions come from near the surface, the observations favor mass ranges of ∼20–24 and ∼36–40 amu. Although many of the observations have properties consistent with a surface or near‐surface release of ions, some do not, suggesting that at least some of the observed ions have an exospheric source. Of all the proposed sources for ions and neutrals about the Moon, the pickup ion flux measured by ARTEMIS correlates best with the solar wind proton flux, indicating that sputtering plays a key role in either directly producing ions from the surface, or producing neutrals that subsequently become ionized.
In vitro and in vivo studies into the biological activities of 1,10-phenanthroline, 1,10-phenanthroline-5,6-dione and its copper(ii) and silver(i) complexes
Authors: McCann Malachy , Santos André L. S. , da Silva Bianca A. , Romanos Maria Teresa V. , Pyrrho Alexandre S. , Devereux Michael , Kavanagh Kevin , Fichtner Iduna , Kellett Andrew 
Published: May 2012

Abstract1,10-Phenanthroline (phen, 5), 1,10-phenanthroline-5,6-dione (phendione, 6), [Cu(phendione)3](ClO4)2·4H2O (12) and [Ag(phendione)2]ClO4 (13) are highly active, in vitro, against a range of normal and cancerous mammalian cells, fungal and insect cell lines, with the metal complexes offering a clear enhancement in activity. Cytoselectivity was not observed between the tumorigenic and non-tumorigenic mammalian lines. In in vivo tests, using Galleria mellonella and Swiss mice, all four compounds were well tolerated in comparison to the clinical agent, cisplatin. In addition, blood samples taken from the Swiss mice showed that the levels of the hepatic enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), remained unaffected. Immunocompromised nude mice showed a much lower tolerance to 13 and, subsequently, when these mice were implanted with Hep-G2 (hepatic) and HCT-8 (colon) human-derived tumors, there was no influence on tumor growth.
Sfrp5 expression and secretion in adipocytes are up‐regulated during differentiation and are negatively correlated with insulin resistance
Authors: Lv Ci , Jiang Youzhao , Wang Hui , Chen Bing 
Published: May 2012

AbstractWe have examined the patterns of Sfrp5 (secreted frizzled‐related protein 5) mRNA expression and protein secretion during adipocyte differentiation, and investigated the potential role of Sfrp5 in IR (insulin resistance) in adipocytes. 3T3‐L1 pre‐adipocytes were induced for differentiation, and RT—PCR (reverse transcription—PCR) and ELISA assays were used to determine Sfrp5 mRNA expression and protein secretion. The results showed that with the differentiation and maturity of pre‐adipocytes, transcription and protein secretion of Sfrp5 gradually increased, peaking on the 9th day of differentiation. Sfrp5 mRNA expression in mature adipocytes was decreased by 20, 22 and 32 upon treatment with dexamethasone, insulin and TNF (tumour necrosis factor) respectively, whereas Sfrp5 protein secretion was decreased by 15, 17 and 30%, correspondingly. In contrast, Sfrp5 mRNA expression in mature adipose was increased by 34 and 19% upon treatment with rosiglitazone and metformin respectively, whereas Sfrp5 protein secretion was increased by 10 and 6%, correspondingly. In conclusion, Sfrp5 mRNA expression and protein secretion depend on the differentiation of adipocytes. The dysregulation of Sfrp5 expression and secretion is directly correlated with IR. Up‐regulation of Sfrp5 expression and secretion in adipocytes may be one crucial mechanism by which rosiglitazone and metformin improve insulin sensitivity.
Epithelial cells in culture: injured or differentiated cells?
Authors: Baer Patrick C. , Bereiter‐Hahn Jürgen 
Published: May 2012

AbstractIsolation of epithelial cells for cell culture is based on destruction of epithelial integrity. The consequences are manifold: cell polarity and specific cell functions are lost; cells acquire non‐epithelial characteristics and start to proliferate. This situation may also occur in situ when parts of the epithelium are lost, either by apoptosis or necrosis by organ or tissue injury. During recovery from this injury, surviving epithelial cells proliferate and may restore epithelial integrity and finally re‐differentiate into functional epithelial cells. In vitro, this re‐differentiation is mostly not complete due to sub‐optimal culture conditions. Therefore cultured epithelial cells resemble wounded or injured epithelia rather than healthy and well differentiated epithelia. The value of an in vitro cell model is the extent to which it helps to understand the function of the cells in situ. A variety of parameters influence the state of differentiation of cultured cells in vitro. Although each of these parameters had been studied, the picture how they co‐ordinately influence the state of differentiation of epithelial cells in vitro is incomplete. Therefore we discuss the influence of the isolation method and cell culture on epithelial cells, and outline strategies to achieve highly differentiated epithelial cells for the use as an in vitro model.
Microcavity array plasma system for remote chemical processing at atmospheric pressure
Authors: Lee Dae-Sung , Hamaguchi Satoshi , Sakai Osamu , Park Sung-Jin , Eden J Gary 
Published: May 2012

Abstract
A microplasma system designed for chemical processing at atmospheric pressure is fabricated and characterized with flowing He/O2 gas mixtures. At the heart of this microcavity dielectric barrier discharge (MDBD) system are two arrays of half-ellipsoidal microcavities engraved by micropowder blasting into dielectric surfaces facing a flowing, low-temperature plasma. Experiments demonstrate that the ignition voltage is reduced, and the spatially averaged optical emission is doubled, for an MDBD flowing plasma array relative to an equivalent system having no microcavities. As an example of the potential of flowing atmospheric microplasma systems for chemical processing, the decomposition of methylene blue (as evidenced by decoloration at 650.2 nm) is shown to proceed at a rate as much as a factor of two greater than that for a non-microcavity equivalent.
Structural characterization of ZnO thin films grown on various substrates by pulsed laser deposition
Authors: Novotný M , Čížek J , Kužel R , Bulíř J , Lančok J , Connolly J , McCarthy E , Krishnamurthy S , Mosnier J-P , Anwand W , Brauer G 
Published: May 2012

Abstract
ZnO thin films were grown by pulsed laser deposition on three different substrates: sapphire (0 0 0 1), MgO (1 0 0) and fused silica (FS). The structure and morphology of the films were characterized by x-ray diffraction and scanning electron microscopy and defect studies were carried out using slow positron implantation spectroscopy (SPIS). Films deposited on all substrates studied in this work exhibit the wurtzite ZnO structure and are characterized by an average crystallite size of 20–100 nm. However, strong differences in the microstructure of films deposited on various substrates were found. The ZnO films deposited on MgO and sapphire single-crystalline substrates exhibit local epitaxy, i.e. a well-defined relation between film crystallites and the substrate. Domains with different orientation relationships with the substrate were found in both films. On the other hand, the film deposited on the FS substrate exhibits fibre texture with random lateral orientation of crystallites. Extremely high compressive in-plane stress of σ ∼ 14 GPa was determined in the film deposited on the MgO substrate, while the film deposited on sapphire is virtually stress-free, and the film deposited on the FS substrate exhibits a tensile in-plane stress of σ ∼ 0.9 GPa. SPIS investigations revealed that the concentration of open-volume defects in the ZnO films is substantially higher than that in a bulk ZnO single crystal. Moreover, the ZnO films deposited on MgO and sapphire single-crystalline substrates exhibit a significantly higher density of defects than the film deposited on the amorphous FS substrate.
Impact of extended defects on Hall and magnetoresistivity effects in cubic silicon carbide
Authors: Vasiliauskas R , Mekys A , Malinovskis P , Juillaguet S , Syväjärvi M , Storasta J , Yakimova R 
Published: May 2012

Abstract
From magnetoresistivity effect measurements the carrier mobility at room temperature is found to be 200 cm2 V−1 s−1 in heteroepitaxially grown 3C-SiC on 6H-SiC by sublimation epitaxy. The main scattering mechanisms are found to be scattering by neutral impurities at low temperatures and by phonons at higher temperatures. The carrier concentration is in the range of 1016 cm−3, which corresponds to the concentration of residual doping by nitrogen acquired from photoluminescence measurements. Using magnetoresistance and Hall mobility data we have created a simple model which quantifies the volume of the samples influenced by extended defects. A higher doping near extended defects is either not present in the samples or might be screened by the electrostatic field created by these defects.
Secondary fluorescence in electron probe microanalysis of material couples
Authors: Llovet X , Pinard P T , Donovan J J , Salvat F 
Published: May 2012

Abstract
We describe a semi-analytical method for the fast calculation of secondary fluorescence in electron probe microanalysis of material couples. The calculation includes contributions from primary K-, L- and M-shell characteristic x-rays and bremsstrahlung photons. The required physical interaction parameters (subshell partial cross sections, attenuation coefficients, etc) are extracted from the database of the Monte Carlo simulation code system PENELOPE. The calculation makes use of the intensities of primary photons released in interactions of beam electrons and secondary electrons. Since these intensities are not readily available and do not allow analytical calculation, they are generated from short Monte Carlo simulation runs. The reliability of the proposed calculation method has been assessed by comparing calculated, distance-dependent k-ratios with experimental data available in the literature and with results from simulations with PENELOPE. Numerical results are found to be in close agreement with both simulated and experimental data.
Progress in characterization and modelling of the current ramp-up phase of ASDEX Upgrade discharges
Authors: Fable E. , Angioni C. , Fischer R. , Geiger B. , McDermott R.M. , Pereverzev G.V. , Puetterich T. , Ryter F. , Scott B. , Tardini G. , Viezzer E. 
Published: May 2012

Abstract
Measurements of plasma core impurity ion temperature and toroidal rotation are obtained during the current ramp-up phases of plasma discharges in the ASDEX Upgrade tokamak, by means of charge exchange recombination spectroscopy utilizing short neutral beam injected blips. The phenomenology of these profiles as the current is varied is presented. The observations are reported for both ohmically heated and electron cyclotron heating assisted ramps, with auxiliary heating applied both on-axis and off-axis. The evolution of global parameters is also reported. A comparison between ion and electron kinetic profiles evolution is made. Power balance analysis is performed to establish the local confinement properties and their evolution during the current ramp. Transport modelling of several cases with a theory-based model is carried out and a recipe, which involves edge-relevant parameters, is proposed to account for the transport in the outer plasma region. Finally, linear gyrokinetic calculations of dominant microinstabilities allow us to correlate the observed transport with the background turbulence regime.
Plasma profile evolution during disruption mitigation via massive gas injection on MAST
Authors: Thornton A.J. , Gibson K.J. , Chapman I.T. , Harrison J.R. , Kirk A. , Lisgo S.W. , Lehnen M. , Martin R. , Scannell R. , Cullen A. 
Published: May 2012

Abstract
Massive gas injection (MGI) is one means of ameliorating disruptions in future devices such as ITER, where the stored energy in the plasma is an order of magnitude larger than in present-day devices. The penetration of the injected impurities during MGI in MAST is diagnosed using a combination of high-speed (20 kHz) visible imaging and high spatial (1 cm) and temporal (0.1 ms) resolution Thomson scattering (TS) measurements of the plasma temperature and density. It is seen that the rational surfaces, in particular q = 2, are the critical surfaces for disruption mitigation. The TS data shows the build-up of density on rational surfaces in the edge cooling period of the mitigation, leading to the collapse of the plasma in a thermal quench. The TS data are confirmed by the visible imaging, which shows filamentary structures present at the start of the thermal quench. The filamentary structures have a topology which matches that of a q = 2 field line in MAST, suggesting that they are located on the q = 2 surface. Linearized magnetohydrodynamic stability analysis using the TS profiles suggests that the large density build-up on the rational surfaces drives modes within the plasma which lead to the thermal quench. The presence of such modes is seen experimentally in the form of magnetic fluctuations on Mirnov coils and the growth of an n = 1 toroidal mode in the period prior to the thermal quench. These results support the observations of other machines that the 2/1 mode is the likely trigger for the thermal quench in a mitigated disruption and suggests that the mitigation process in spherical tokamaks is similar to that in conventional aspect ratio devices.
Scrape-off layer ion acceleration during fast wave injection in the DIII-D tokamak
Authors: Pace D.C. , Pinsker R.I. , Heidbrink W.W. , Fisher R.K. , Van Zeeland M.A. , Austin M.E. , McKee G.R. , García-Muñoz M. 
Published: May 2012

Abstract
Fast wave injection is employed on the DIII-D tokamak as a current drive and electron heating method. Bursts of energetic ions with energy E
o > 20 keV are observed immediately following fast wave injection in experiments featuring the 8th ion cyclotron harmonic near the antenna. Using the energy and pitch angle of the energetic ion burst as measured by a fast-ion loss detector, it is possible to trace the origin of these ions to a particular antenna. The ion trajectories exist entirely within the scrape-off layer. These observations are consistent with the presence of parametric decay instabilities near the antenna strap. It is suggested that the phase space capabilities of the loss detector diagnostic can improve studies of wave injection coupling and efficiency in tokamaks by directly measuring the effects of parametric decay thresholds.
Increased Rho kinase activity in congestive heart failure
Authors: Dong Ming , Liao James K. , Fang Fang , Lee Alex Pui‐Wai , Yan Bryan Ping‐Yen , Liu Ming , Yu Cheuk‐Man 
Published: May 2012

AimsRho kinases (ROCKs) are the best characterized effectors of the small G‐protein RhoA, and play a role in enhanced vasoconstriction in animal models of congestive heart failure (CHF). This study examined if ROCK activity is increased in CHF and how it is associated with the outcome in CHF.Methods and resultsPatients admitted with CHF (n =178), disease controls (n =31), and normal subjects (n =30) were studied. Baseline ROCK activity was measured by phosphorylation of themyosin‐binding subunit in peripheral leucocytes. The patients were followed up for 14.4 ± 7.2 months (range 0.5–26 months) or until the occurrence of cardiac death. The ROCK activity in CHF patients (2.93 ± 0.87) was significantly higher than that of the disease control (2.06 ± 0.38, P < 0.001) and normal control (1.57 ± 0.43, P < 0.001) groups. Similarly, protein levels of ROCK1 and ROCK2 as well as the activity of RhoA in CHF were significantly higher than in disease controls and normal controls (all P < 0.05). Dyspnoea at rest (β =0.338, P < 0.001), low left ventricular ejection fraction (β = –0.277, P < 0.001), and high creatinine (β =0.202, P =0.006) were independent predictors of the baseline ROCK activity in CHF. Forty‐five patients died within 2 years follow‐up (25.3%). Combining ROCK activity and N‐terminal pro brain natriuretic peptide (NT‐proBNP) had an incremental value (log rank χ2 =11.62) in predicting long‐term mortality when compared with only NT‐proBNP (log rank χ2 =5.16, P < 0.05).ConclusionROCK activity is increased in CHF and it might be associated with the mortality in CHF. ROCK activity might be a complementary biomarker to CHF risk stratification.
Acute effect of percutaneous MitraClip therapy in patients with haemodynamic decompensation
Authors: Biner Simon , Siegel Robert J. , Feldman Ted , Rafique Asim M. , Trento Alfredo , Whitlow Patrick , Rogers Jason , Moon Marc , Lindman Brian , Zajarias Alan , Glower Donald , Kar Saibal ,   on behalf of the EVEREST investigators
Published: May 2012

AimsTo evaluate the haemodynamic effect of acute procedural success (APS) after MitraClip therapy in patients with haemodynamic decompensation.Methods and resultsOf 107 patients, 79 achieved APS after MitraClip implantation. The increase in cardiac index (CI) was primarily detected in patients with a low baseline CI (2.0 ± 0.5 to 2.5 ± 5 L/min/m2, P < 0.001). There was a decrease in left ventricular end‐diastolic pressure (LVEDP) (20 ± 5 to 13 ± 5 mmHg, P = 0.002) and mean pulmonary capillary wedge pressure (PCWPm) (20 ± 4 to 16 ± 5 mmHg, P = 0.001) in patients with values >15 mmHg at baseline, and a decrease in mean pulmonary artery systolic (PAPm) (36 ± 4 to 29 ± 7 mmHg P = 0.003) in those with values >30 mmHg before the MitraClip procedure. Patients with decompensation compared with patients with compensation experienced significant reduction in LVEDP (–8.3 ± 11.9 mmHg vs. –0.2 ± 4.5 mmHg, P = 0.009), a reduction in PCWPm (–3.5 ± 5.6 mmHg vs. 1.9 ± 4.7 mmHg, P < 0.001), and a reduction in PAPm (–8 ± 9 mmHg vs. 3 ± 6 mmHg, P < 0.001).ConclusionThe favourable haemodynamic effects of MitraClip therapy on CI were primarily detected in patients with low CI before the procedure, and improvements in left‐sided filling pressure and PAP were primarily seen in those with elevated values at baseline.