Moving Magnetic Features around a Pore

Spectropolarimetric observations from Sunrise II/IMaX obtained in June 2013 are used for a statistical analysis to determine the physical properties of moving magnetic features (MMFs) observed near a pore. MMFs of the same and opposite polarity with respect to the pore are found to stream from its border at an average speed of 1.3 km s$^{-1}$ and 1.2 km s$^{-1}$ respectively, with mainly same-polarity MMFs found further away from the pore. MMFs of both polarities are found to harbor rather weak, inclined magnetic fields. Opposite-polarity MMFs are blue-shifted, while same-polarity MMFs do not show any preference for up- or downflows. Most of the MMFs are found to be of sub-arcsecond size and carry a mean flux of $\sim$ 1.2$\times 10^{17}$ Mx.Comment: 8 pages, 4 figures, accepted for publication in ApJ

Maximum Entropy Limit of Small-scale Magnetic Field Fluctuations in the Quiet Sun

The observed magnetic field on the solar surface is characterized by a very complex spatial and temporal behavior. Although feature-tracking algorithms have allowed us to deepen our understanding of this behavior, subjectivity plays an important role in the identification and tracking of such features. In this paper, we continue studies Gorobets, A. Y., Borrero, J. M., & Berdyugina, S. 2016, ApJL, 825, L18 of the temporal stochasticity of the magnetic field on the solar surface without relying either on the concept of magnetic features or on subjective assumptions about their identification and interaction. We propose a data analysis method to quantify fluctuations of the line-of-sight magnetic field by means of reducing the temporal field's evolution to the regular Markov process. We build a representative model of fluctuations converging to the unique stationary (equilibrium) distribution in the long time limit with maximum entropy. We obtained different rates of convergence to the equilibrium at fixed noise cutoff for two sets of data. This indicates a strong influence of the data spatial resolution and mixing-polarity fluctuations on the relaxation process. The analysis is applied to observations of magnetic fields of the relatively quiet areas around an active region carried out during the second flight of the Sunrise/IMaX and quiet Sun areas at the disk center from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory satellite.Comment: 11 pages, 5 figures, The Astrophysical Journal Supplement Series (accepted

Reaction pathways and textural aspects of the replacement of anhydrite by calcite at 25 °C

The replacement of sulfate minerals by calcium carbonate polymorphs (carbonation) has important implications in various geological processes occurring in Earth surface environments. In this paper we report the results of an experimental study of the interaction between anhydrite (100), (010), and (001) surfaces and Na₂CO₃ aqueous solutions under ambient conditions. Carbonation progress was monitored by glancing incidence X-ray diffraction (GIXRD) and scanning electron microscopy (SEM). We show that the reaction progresses through the dissolution of anhydrite and the simultaneous growth of calcite. The growth of calcite occurs oriented on the three anhydrite cleavage surfaces and its formation is accompanied by minor vaterite. The progress of the carbonation always occurs from the outer-ward to the inner-ward surfaces and its rate depends on the anhydrite surface considered, with the (001) surface being much more reactive than the (010) and (100) surfaces. The thickness of the formed carbonate layer grows linearly with time. The original external shape of the anhydrite crystals and their surface details (e.g., cleavage steps) are preserved during the carbonation reaction. Textural characteristics of the transformed regions, such as the gradation in the size of calcite crystals, from ~2 μm in the outer region to ~17 μm at the calcite-anhydrite interface, the local preservation of calcite crystalographic orientation with respect to anhydrite and the distribution of the microporosity mainly within the carbonate layer without development of any significant gap at the calcite-anhydrite interface. Finally, we compare these results on anhydrite carbonation with those on gypsum carbonation and can explain the differences on the basis of four parameters: (1) the molar volume change involved in the replacement process in each case, (2) the lack/existence of epitactic growth between parent and product phases, (3) the kinetics of dissolution of the different surfaces, and (4) the chemical composition (amount of structural water) of the parent phases

Improving the understanding of N transport in a rural catchment under Atlantic climate conditions from the analysis of the concentration–discharge relationship derived from a high-frequency data set

Understanding processes controlling stream nutrient dynamics over time is crucial for implementing effective management strategies to prevent water quality degradation. In this respect, the study of the nutrient concentration–discharge (C–Q) relationship during individual runoff events can be a valuable tool for extrapolating the hydrochemical processes controlling nutrient fluxes in streams. This study investigated nitrogen concentration dynamics during events by analyzing and interpreting the nitrogen C–Q relationship in a small Atlantic (NW Iberian Peninsula) rural catchment. To this end, nitrate (NO3-N) and total Kjeldahl nitrogen (TKN) concentrations were monitored at a high temporal resolution during 102 runoff events over a 6-year period. For each of the selected runoff events, C–Q response was examined visually for the presence and direction of hysteresis loops and classified into three types of responses, namely clockwise, counterclockwise, and no hysteresis. Changes in concentration (ΔC) and the hysteresis direction (ΔR) were used to quantify nitrogen (NO3- and TKN) patterns during the runoff events. The transport mechanisms varied between compounds. The most frequent hysteretic response for NO3- was counterclockwise with enrichment. On the contrary, the main TKN dynamic was enrichment with clockwise hysteresis. Event characteristics, such as rainfall amount, peak discharge (i.e., maximum discharge of the runoff event), and event magnitude relative to the initial baseflow (i.e., the difference between the maximum discharge of the runoff event and the initial baseflow divided by initial baseflow) provided a better explanation for hysteresis direction and magnitude for TKN than antecedent conditions (antecedent precipitation and baseflow at the beginning of the event). For NO3- hysteresis, the role of hydrometeorological conditions was more complex. The NO3- hysteresis magnitude was related to the magnitude of the event relative to the initial baseflow and the time elapsed since a preceding runoff event. These findings could be used as a reference for the development of N mitigation strategy in the region.</p

Non-monotonic behavior of weak-polyelectrolytes adsorption on a cationic surface: A Monte Carlo simulation study

In this work, the weak polyelectrolyte (PE) adsorption on a strong cationic surface is studied with constant pH Monte Carlo simulations using a coarse-grained model. When a large number of PE chains is added to the system, the PE adsorbed amount vs pH curve exhibits a non-monotonic behavior, with the appearance of a maximum close to the intrinsic pKa0-value of the PE titratable groups. The apparent pKa-value of the PE chains shows a non-trivial tendency depending on the pH-value and the surface coverage degree. In increasing the pH-value, the small anions that accompany the cationic surface are replaced by PE chains and small cations. For pH>pKa0+1, an evident charge reversion of surface is observed. These results are explained analyzing the interplay between the attractive and repulsion electrostatic interactions between the different components of the system (inter- and intra-charged monomers of PE chains, the strong cationic surface and small ions) and their effects on the PE chain ionization.Fil: Narambuena, Claudio Fabian. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - San Luis. Instituto de Fisica Aplicada "dr. Jorge Andres Zgrablich". Grupo Vinculado Bionanotecnologia y Sistemas Complejos | Universidad Nacional de San Luis. Facultad de Cs.fisico Matematicas y Naturales. Instituto de Fisica Aplicada "dr. Jorge Andres Zgrablich". Grupo Vinculado Bionanotecnologia y Sistemas Complejos. - Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Grupo Vinculado Bionanotecnologia y Sistemas Complejos.; ArgentinaFil: Blanco, Pablo M.. Universidad de Barcelona. Facultad de Quimica. Instituto de Quimica Teorica y Computacional.; EspañaFil: Rodriguez, Adrian. Universidad Tecnológica Nacional. Facultad Reg. Neuquen; ArgentinaFil: Rodríguez, Diego E.. Universidad Tecnológica Nacional. Facultad Reg. Neuquen; ArgentinaFil: Madurga, Sergio. Universidad de Barcelona. Facultad de Quimica. Instituto de Quimica Teorica y Computacional.; EspañaFil: Garcés, José L.. Universidad de Barcelona. Facultad de Quimica. Instituto de Quimica Teorica y Computacional.; EspañaFil: Mas Pujadas, Francesc. Universidad de Barcelona. Facultad de Quimica. Instituto de Quimica Teorica y Computacional.; Españ

Anti-MPER antibodies with heterogeneous neutralization capacity are detectable in most untreated HIV-1 infected individuals

Background The MPER region of the HIV-1 envelope glycoprotein gp41 is targeted by broadly neutralizing antibodies. However, the localization of this epitope in a hydrophobic environment seems to hamper the elicitation of these antibodies in HIV infected individuals. We have quantified and characterized anti-MPER antibodies by ELISA and by flow cytometry using a collection of mini gp41-derived proteins expressed on the surface of 293T cells. Longitudinal plasma samples from 35 HIV-1 infected individuals were assayed for MPER recognition and MPER-dependent neutralizing capacity using HIV-2 viruses engrafted with HIV-1 MPER sequences. Results Miniproteins devoid of the cysteine loop of gp41 exposed the MPER on 293T cell membrane. Anti-MPER antibodies were identified in most individuals and were stable when analyzed in longitudinal samples. The magnitude of the responses was strongly correlated with the global response to the HIV-1 envelope glycoprotein, suggesting no specific limitation for anti-MPER antibodies. Peptide mapping showed poor recognition of the C-terminal MPER moiety and a wide presence of antibodies against the 2F5 epitope. However, antibody titers failed to correlate with 2F5-blocking activity and, more importantly, with the specific neutralization of HIV-2 chimeric viruses bearing the HIV-1 MPER sequence; suggesting a strong functional heterogeneity in anti-MPER humoral responses. Conclusions Anti-MPER antibodies can be detected in the vast majority of HIV-1 infected individuals and are generated in the context of the global anti-Env response. However, the neutralizing capacity is heterogeneous suggesting that eliciting neutralizing anti-MPER antibodies by immunization might require refinement of immunogens to skip nonneutralizing responses

A functional variant in the stearoyl-CoA desaturase (SCD) gene promoter affects gene expression in ovine muscle

The nutritional quality of lambs may be improved with increased stearoyl-CoA desaturase (SCD) gene expression, which increases the desaturation of stearic acid to oleic acid. The aim of this study was to evaluate the effect of the rs412429481 (FJ513370: g.31C > A) SNP located at the SCD gene on the functionality of the gene in lambs reared under different production systems. The effect of the rs412429481 SNP on gene expression in Rasa Aragonesa male lambs slaughtered at 22–24 kg was studied in two experiments. In Experiment 1 (n = 44), the semitendinosus muscle of lambs grazing alfalfa (ALF) or fed concentrates indoors (IND) was analysed; in Experiment 2 (n = 48), the semitendinosus and longissimus thoracis muscles of lambs that received supplementation with dl-a-tocopheryl acetate for different finishing periods were used. In Experiment 1, the effect of the rs412429481 SNP on the expression of the SCD gene in the semitendinosus muscle depended on the feeding group (P < 0.001), as it had no effect in ALF lambs, but CA lambs had greater SCD expression than CC lambs under the IND conditions. Moreover, ALF lambs showed lower levels of SCD gene expression than IND lambs (P < 0.05). In Experiment 2, gene expression was affected by the rs412429481 SNP in both muscles. Animals carrying the C- allele showed a lower expression rate than animals carrying the A- allele. These different expression levels were not associated with changes in the DNA methylation pattern or by the binding of specific nuclear proteins. Finally, we confirmed these results by luciferase assays, demonstrating that the SCD promoter containing the A variant had a 23.9% higher activity than the promoter containing the C variant

Incidencia del ejercicio físico y el entrenamiento vibratorio sobre la amplitud de movimiento de mujeres con fibromialgia

ResumenObjetivoEn la presente investigación hemos planteado como objetivos principales, por un lado, valorar el efecto del ejercicio físico y el entrenamiento vibratorio sobre la amplitud de movimiento en mujeres con fibromialgia (FM) y, por otro, determinar si existe alguna relación entre dicha variable y el dolor y la rigidez.MétodoLa muestra estuvo constituida por un total de cuarenta y seis mujeres (edad: 58,2±8,5 años; peso: 72,1±9,6kg; altura: 156,9±6,1cm) diagnosticadas con FM. Los participantes fueron divididos aleatoriamente en tres grupos: ejercicio físico y entrenamiento vibratorio (WBV + EJ; n=15); ejercicio físico sin vibraciones (EJ; n=15) y un grupo control (GC; n=16). Los grupos WBV + EJ y EJ realizaron dos sesiones semanales de ejercicio físico durante 8 semanas. Además, los integrantes de WBV + EJ realizaron 3 sesiones semanales de entrenamiento vibratorio (30Hz, 4mm). Las pruebas de evaluación incluyeron el test de sit and reach (variable principal), la valoración del número de tender points (TP) y una escala analógica visual (VAS) para determinar la rigidez.ResultadosLos resultados derivados del análisis intra e intergrupo no mostraron diferencias significativas en la rigidez o el número de TP, si bien, la prueba de sit and reach mostró una mejora estadísticamente significativa en WBV + EJ (58%; p<0,05). El análisis correlacional mostró una relación inversa (r =-0,55; p<0,05) entre el sit and reach y el número de TP.ConclusiónComo conclusión, podemos indicar que los datos obtenidos en la presente investigación han mostrado los efectos significativos del entrenamiento vibratorio sobre la amplitud de movimiento en mujeres con FM, aunque el número de TP o la rigidez no se vieron afectados en ningún caso.AbstractObjectiveThe main aim of this investigation was twofold: first to evaluate the effects of exercise and whole body vibration training on flexibility in women with fibromyalgia (FM) and determine whether these improvements are related to symptom severity (stiffness and bodily pain).MethodForty-six women (mean±sd, age: 58.2±8.5 years; weight: 72.1±9.6kg; height: 156.9±6.1cm) with FM were randomized into one of three groups: exercise and whole body vibration (WBV) training group (WBV + EX; n=15), exercise training group (EX), and usual-care control group (CG). WBV + EX and EX groups carried out two sessions per week of exercise training for 8 weeks. In addition, WBV + EX group performed 3 vibration-training (30Hz, 4mm) sessions per week. Outcome assessed included sit and reach test (primary outcome), tender points (TP) evaluation, and a visual analog scale (VAS) was used to determine the stiffness level.ResultsResults showed no statistical intra and intergroup differences in stiffness or the number of TP. However, a significant increment in the sit and reach performance was observed in WBV + EX (58%; p<0.05). Moreover, correlation analysis showed an inverse and significant relationship (r=-0.55; p<0.05) between sit and reach and number of TP in WBV+EX group.ConclusionIn conclusion, exercise and WBV seems to be effective on flexibility in women with FM. However, the number of TP and stiffness was not modified after the interventio