Small-scale magnetic flux emergence in the quiet Sun

Small bipolar magnetic features are observed to appear in the interior of individual granules in the quiet Sun, signaling the emergence of tiny magnetic loops from the solar interior. We study the origin of those features as part of the magnetoconvection process in the top layers of the convection zone. Two quiet-Sun magnetoconvection models, calculated with the radiation-magnetohydrodynamic (MHD) Bifrost code and with domain stretching from the top layers of the convection zone to the corona, are analyzed. Using 3D visualization as well as a posteriori spectral synthesis of Stokes parameters, we detect the repeated emergence of small magnetic elements in the interior of granules, as in the observations. Additionally, we identify the formation of organized horizontal magnetic sheets covering whole granules. Our approach is twofold, calculating statistical properties of the system, like joint probability density functions (JPDFs), and pursuing individual events via visualization tools. We conclude that the small magnetic loops surfacing within individual granules in the observations may originate from sites at or near the downflows in the granular and mesogranular levels, probably in the first 1 or 1.5 Mm below the surface. We also document the creation of granule-covering magnetic sheet-like structures through the sideways expansion of a small subphotospheric magnetic concentration picked up, and pulled out of the interior, by a nascent granule. The sheet-like structures we found in the models may match the recent observations of Centeno et al. (2017).Comment: 9 pages, 5 figures, Published in The Astrophysical Journal Letter

Southern Annular Mode-like changes in southwestern Patagonia at centennial timescales over the last three millennia

Late twentieth-century instrumental records reveal a persistent southward shift of the Southern Westerly Winds during austral summer and autumn associated with a positive trend of the Southern Annular Mode (SAM) and contemporaneous with glacial recession, steady increases in atmospheric temperatures and CO2 concentrations at a global scale. However, despite the clear importance of the SAM in the modern/future climate, very little is known regarding its behaviour during pre-Industrial times. Here we present a stratigraphic record from Lago Cipreses (51S), southwestern Patagonia, that reveals recurrent B200-year long dry/warm phases over the last three millennia, which we interpret as positive SAM-like states. These correspond in timing with the Industrial revolution, the Mediaeval Climate Anomaly, the Roman and Late Bronze Age Warm Periods and alternate with cold/wet multicentennial phases in European palaeoclimate records. We conclude that SAM-like changes at centennial timescales in southwestern Patagonia represent in-phase interhemispheric coupling of palaeoclimate over the last 3,000 years through atmospheric teleconnections.Fil: Moreno, Patricio. Universidad de Chile; ChileFil: Vilanova, Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Villa Martinez, R.. Universidad de Chile; ChileFil: Garreaud, R. D.. Universidad de Chile; ChileFil: Rojas, M.. Universidad de Chile; ChileFil: De Pol Holz, R.. Universidad de Chile; Chil

Lower Cretaceous (Hauterivian-Albian) ammonite biostratigraphy in the Maestrat Basin (E Spain)

Peer reviewedPublisher PD

Collision cascade effects near an edge dislocation dipole in alpha-Fe: Induced dislocation mobility and enhanced defect clustering

Collision cascades near a 1/2⟨111⟩{110} edge dipole in alpha-iron have been studied using molecular dynamics simulations for a recoil energy of 20 keV and two temperatures, 20 K and 300 K. These simulations show that the collision cascade induces the migration of the dislocations through glide along its slip plane. The motion of the dislocations starts at the peak of the collision cascade and expands a time scale much longer than the cascade duration, until restoring the equilibrium distance of the dipole, regardless of the damage produced by the cascade. At the initial stages, kinks are formed at the dislocation that enhance glide. When defects reach the dislocations, jogs are produced. We show that the initial dislocation motion is triggered by the shock wave of the collision cascade. The cascade morphology is also strongly influenced by the presence of the dislocations, having an elongated form at the peak of the displacement, which demonstrates the strong interaction of the dislocations with the cascade even at the early stages. Finally, we show that larger vacancy clusters are formed in the presence of dislocations compared to isolated cascades and that these clusters are larger for 300 K compared to 20 K.This work was partly supported by the Generalitat Valenciana through PROMETEO2017/139. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. EM gratefully acknowledges support from the U.S. DOE, Office of Science, Office of Fusion Energy Sciences, and Office of Advanced Scientific Computing Research through the Scientific Discovery through Advanced Computing (SciDAC) project on Plasma-Surface Interactions (award no. DE-SC0008875)

Estimating the Relative Stiffness between a Hepatic Lesion and the Liver Parenchyma through Biomechanical Simulations of the Breathing Process

[EN] In this paper, a method to in vivo estimate the relative stifness between a hepatic lesion and the liver parenchyma is presented. Tis method is based on the fnite element simulation of the deformation that the liver undergoes during the breathing process. Boundary conditions are obtained through a registration algorithm known as Coherent Point Drif (CPD), which compares the liver form in two phases of the breathing process. Finally, the relative stifness of the tumour with respect to the liver parenchyma is calculated by means of a Genetic Algorithm, which does a blind search of this parameter. Te relative stifness together with the clinical information of the patient can be used to establish the type of hepatic lesion. Te developed methodology was frst applied to a test case, i.e., to a control case where the parameters were known, in order to verify its validity. Afer that, the method was applied to two real cases and low errors were obtained.This work has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through research projects DPI2013-40859-R and TIN2014-52033-R, both also supported by European FEDER funds.Martinez-Sanchis, S.; Rupérez Moreno, MJ.; Nadal, E.; Pareja, E.; Brugger, S.; Borzacchiello, D.; López, R.... (2018). Estimating the Relative Stiffness between a Hepatic Lesion and the Liver Parenchyma through Biomechanical Simulations of the Breathing Process. Mathematical Problems in Engineering. 1-10. https://doi.org/10.1155/2018/5317324S110Kmieć, Z. (2001). Introduction — Morphology of the Liver Lobule. Advances in Anatomy Embryology and Cell Biology, 1-6. doi:10.1007/978-3-642-56553-3_1Cequera, A., & García de León Méndez, M. C. (2014). Biomarkers for liver fibrosis: Advances, advantages and disadvantages. Revista de Gastroenterología de México (English Edition), 79(3), 187-199. doi:10.1016/j.rgmxen.2014.07.001Vilar-Gomez, E., & Chalasani, N. (2018). Non-invasive assessment of non-alcoholic fatty liver disease: Clinical prediction rules and blood-based biomarkers. Journal of Hepatology, 68(2), 305-315. doi:10.1016/j.jhep.2017.11.013Giannini, E. G. (2005). Liver enzyme alteration: a guide for clinicians. Canadian Medical Association Journal, 172(3), 367-379. doi:10.1503/cmaj.1040752Oliva, M. R. (2004). Liver cancer imaging: role of CT, MRI, US and PET. Cancer Imaging, 4(Special Issue A), S42-S46. doi:10.1102/1470-7330.2004.0011Mouw, J. K., Yui, Y., Damiano, L., Bainer, R. O., Lakins, J. N., Acerbi, I., … Weaver, V. M. (2014). Tissue mechanics modulate microRNA-dependent PTEN expression to regulate malignant progression. Nature Medicine, 20(4), 360-367. doi:10.1038/nm.3497Paszek, M. J., Zahir, N., Johnson, K. R., Lakins, J. N., Rozenberg, G. I., Gefen, A., … Weaver, V. M. (2005). Tensional homeostasis and the malignant phenotype. Cancer Cell, 8(3), 241-254. doi:10.1016/j.ccr.2005.08.010Kuo, Y.-H., Lu, S.-N., Hung, C.-H., Kee, K.-M., Chen, C.-H., Hu, T.-H., … Wang, J.-H. (2010). Liver stiffness measurement in the risk assessment of hepatocellular carcinoma for patients with chronic hepatitis. Hepatology International, 4(4), 700-706. doi:10.1007/s12072-010-9223-1Heide, R., Strobel, D., Bernatik, T., & Goertz, R. (2010). Characterization of Focal Liver Lesions (FLL) with Acoustic Radiation Force Impulse (ARFI) Elastometry. Ultraschall in der Medizin - European Journal of Ultrasound, 31(04), 405-409. doi:10.1055/s-0029-1245565Frulio, N., Laumonier, H., Carteret, T., Laurent, C., Maire, F., Balabaud, C., … Trillaud, H. (2013). Evaluation of Liver Tumors Using Acoustic Radiation Force Impulse Elastography and Correlation With Histologic Data. Journal of Ultrasound in Medicine, 32(1), 121-130. doi:10.7863/jum.2013.32.1.121Ma, X., Zhan, W., Zhang, B., Wei, B., Wu, X., Zhou, M., … Li, P. (2014). Elastography for the differentiation of benign and malignant liver lesions: a meta-analysis. Tumor Biology, 35(5), 4489-4497. doi:10.1007/s13277-013-1591-4Guo, L.-H., Wang, S.-J., Xu, H.-X., Sun, L.-P., Zhang, Y.-F., Xu, J.-M., … Xu, X.-H. (2015). Differentiation of benign and malignant focal liver lesions: value of virtual touch tissue quantification of acoustic radiation force impulse elastography. Medical Oncology, 32(3). doi:10.1007/s12032-015-0543-9Dietrich, C., Bamber, J., Berzigotti, A., Bota, S., Cantisani, V., Castera, L., … Thiele, M. (2017). EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography, Update 2017 (Long Version). Ultraschall in der Medizin - European Journal of Ultrasound, 38(04), e16-e47. doi:10.1055/s-0043-103952Ferraioli, G., Filice, C., Castera, L., Choi, B. I., Sporea, I., Wilson, S. R., … Kudo, M. (2015). WFUMB Guidelines and Recommendations for Clinical Use of Ultrasound Elastography: Part 3: Liver. Ultrasound in Medicine & Biology, 41(5), 1161-1179. doi:10.1016/j.ultrasmedbio.2015.03.007Sigrist, R. M. S., Liau, J., Kaffas, A. E., Chammas, M. C., & Willmann, J. K. (2017). Ultrasound Elastography: Review of Techniques and Clinical Applications. Theranostics, 7(5), 1303-1329. doi:10.7150/thno.18650Cosgrove, D., Piscaglia, F., Bamber, J., Bojunga, J., Correas, J.-M., Gilja, O., … Dietrich, C. (2013). EFSUMB Guidelines and Recommendations on the Clinical Use of Ultrasound Elastography.Part 2: Clinical Applications. Ultraschall in der Medizin - European Journal of Ultrasound, 34(03), 238-253. doi:10.1055/s-0033-1335375Palmeri, M. L., & Nightingale, K. R. (2011). What challenges must be overcome before ultrasound elasticity imaging is ready for the clinic? Imaging in Medicine, 3(4), 433-444. doi:10.2217/iim.11.41Samir, A. E., Dhyani, M., Vij, A., Bhan, A. K., Halpern, E. F., Méndez-Navarro, J., … Chung, R. T. (2015). Shear-Wave Elastography for the Estimation of Liver Fibrosis in Chronic Liver Disease: Determining Accuracy and Ideal Site for Measurement. Radiology, 274(3), 888-896. doi:10.1148/radiol.14140839Toshima, T., Shirabe, K., Takeishi, K., Motomura, T., Mano, Y., Uchiyama, H., … Maehara, Y. (2011). New method for assessing liver fibrosis based on acoustic radiation force impulse: a special reference to the difference between right and left liver. Journal of Gastroenterology, 46(5), 705-711. doi:10.1007/s00535-010-0365-7Barr, R. G., Ferraioli, G., Palmeri, M. L., Goodman, Z. D., Garcia-Tsao, G., Rubin, J., … Levine, D. (2015). Elastography Assessment of Liver Fibrosis: Society of Radiologists in Ultrasound Consensus Conference Statement. Radiology, 276(3), 845-861. doi:10.1148/radiol.2015150619Venkatesh, S. K., Yin, M., & Ehman, R. L. (2013). Magnetic resonance elastography of liver: Technique, analysis, and clinical applications. Journal of Magnetic Resonance Imaging, 37(3), 544-555. doi:10.1002/jmri.23731Low, G. (2016). General review of magnetic resonance elastography. World Journal of Radiology, 8(1), 59. doi:10.4329/wjr.v8.i1.59Thompson, S. M., Wang, J., Chandan, V. S., Glaser, K. J., Roberts, L. R., Ehman, R. L., & Venkatesh, S. K. (2017). MR elastography of hepatocellular carcinoma: Correlation of tumor stiffness with histopathology features—Preliminary findings. Magnetic Resonance Imaging, 37, 41-45. doi:10.1016/j.mri.2016.11.005Myronenko, A., & Xubo Song. (2010). Point Set Registration: Coherent Point Drift. IEEE Transactions on Pattern Analysis and Machine Intelligence, 32(12), 2262-2275. doi:10.1109/tpami.2010.46Martínez-Martínez, F., Lago, M. A., Rupérez, M. J., & Monserrat, C. (2013). Analysis of several biomechanical models for the simulation of lamb liver behaviour using similarity coefficients from medical image. Computer Methods in Biomechanics and Biomedical Engineering, 16(7), 747-757. doi:10.1080/10255842.2011.637492Untaroiu, C. D., & Lu, Y.-C. (2013). Material characterization of liver parenchyma using specimen-specific finite element models. Journal of the Mechanical Behavior of Biomedical Materials, 26, 11-22. doi:10.1016/j.jmbbm.2013.05.013Large deformation isotropic elasticity – on the correlation of theory and experiment for incompressible rubberlike solids. (1972). Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 326(1567), 565-584. doi:10.1098/rspa.1972.0026Chui, C., Kobayashi, E., Chen, X., Hisada, T., & Sakuma, I. (2006). Transversely isotropic properties of porcine liver tissue: experiments and constitutive modelling. Medical & Biological Engineering & Computing, 45(1), 99-106. doi:10.1007/s11517-006-0137-yHostettler, A., George, D., Rémond, Y., Nicolau, S. A., Soler, L., & Marescaux, J. (2010). Bulk modulus and volume variation measurement of the liver and the kidneys in vivo using abdominal kinetics during free breathing. Computer Methods and Programs in Biomedicine, 100(2), 149-157. doi:10.1016/j.cmpb.2010.03.003Chatterjee, S., Laudato, M., & Lynch, L. A. (1996). Genetic algorithms and their statistical applications: an introduction. Computational Statistics & Data Analysis, 22(6), 633-651. doi:10.1016/0167-9473(96)00011-4Martínez-Martínez, F., Rupérez, M. J., Martín-Guerrero, J. D., Monserrat, C., Lago, M. A., Pareja, E., … López-Andújar, R. (2013). Estimation of the elastic parameters of human liver biomechanical models by means of medical images and evolutionary computation. Computer Methods and Programs in Biomedicine, 111(3), 537-549. doi:10.1016/j.cmpb.2013.05.005Lago, M. A., Rupérez, M. J., Martínez-Martínez, F., Monserrat, C., Larra, E., Güell, J. L., & Peris-Martínez, C. (2015). A new methodology for the in vivo estimation of the elastic constants that characterize the patient-specific biomechanical behavior of the human cornea. Journal of Biomechanics, 48(1), 38-43. doi:10.1016/j.jbiomech.2014.11.009Lago, M. A., Rupérez, M. J., Martínez-Martínez, F., Martínez-Sanchis, S., Bakic, P. R., & Monserrat, C. (2015). Methodology based on genetic heuristics for in-vivo characterizing the patient-specific biomechanical behavior of the breast tissues. Expert Systems with Applications, 42(21), 7942-7950. doi:10.1016/j.eswa.2015.05.058Hoyt, K., Castaneda, B., Zhang, M., Nigwekar, P., di Sant’Agnese, P. A., Joseph, J. V., … Parker, K. J. (2008). Tissue elasticity properties as biomarkers for prostate cancer. Cancer Biomarkers, 4(4-5), 213-225. doi:10.3233/cbm-2008-44-505Xu, W., Mezencev, R., Kim, B., Wang, L., McDonald, J., & Sulchek, T. (2012). Cell Stiffness Is a Biomarker of the Metastatic Potential of Ovarian Cancer Cells. PLoS ONE, 7(10), e46609. doi:10.1371/journal.pone.0046609Martinez-Sanchis, S., Rupérez, M. J., Nadal, E., Borzacchiello, D., Monserrat, C., Pareja, E., … López-Andújar, R. (2017). Estimating the Patient-Specific Relative Stiffness Between a Hepatic Lesion and the Liver Parenchyma. Lecture Notes in Computational Vision and Biomechanics, 485-494. doi:10.1007/978-3-319-68195-5_5

Microparticle subpopulations are potential markers of disease progression and vascular dysfunction across a spectrum of connective tissue disease

OBJECTIVE: Microparticles (MPs) are membrane-bound vesicles derived from vascular and intravascular cells such as endothelial cells (EMPs) and platelets (PMPs). We investigated EMP and PMP numbers across a spectrum of autoimmune rheumatic diseases (AIRDs) with the aim of comparing the levels of, and relationship between, EMPs and PMPs.METHODS: Patients with Systemic Lupus Erythematosus (SLE) (n = 24), Systemic Sclerosis (SSc) (n = 24), Primary Raynauds Phenomenon (RP) (n = 17) and "other CTD" (n = 15) (Primary Sjogrens Syndrome, UCTD or MCTD) as well as 15 healthy controls were recruited. EMPs and PMPs were quantified using flow cytometry. Associations between MP levels and objective functional vascular assessments were evaluated.RESULTS: SLE patients had significantly higher EMPs compared with healthy controls and SSc patients. Higher PMP levels were noted in SSc and primary RP when compared to healthy controls and 'other CTD' patients. A modest correlation was noted between EMP and PMP levels in healthy controls (Spearman r = 0.6, p = 0.017). This relationship appeared stronger in SLE (r = 0.72, p &lt; 0.0001) and other CTD patients (r = 0.75, p &lt; 0.0001). The association between EMPs and PMPs was notably less strong in SSc (r = 0.45, p = 0.014) and RP (r = 0.37, p = 0.15). A significantly lower EMP/PMP ratio was detected in SSc/RP patients in comparison to both healthy controls and SLE/other CTD patients. Higher EMP and PMP levels were associated with higher digital perfusion following cold challenge in SSc. In contrast, higher PMP (but not EMP) levels were associated with lower digital perfusion at both baseline and following cold challenge in primary RP. Higher PMP levels were associated with greater endothelial-independent dilation in patients with SLE.CONCLUSION: MP populations differ across the spectrum of AIRDS, possibly reflecting differences in vascular cell injury and activation. MP levels are associated with functional assessments of vascular function and might have a role as novel vascular biomarkers in AIRDs.SIGNIFICANCE AND INNOVATIONS: Levels of circulating endothelial and platelet microparticles differ between SSc/primary RP compared with SLE and other CTDs (UCTD, MCTD and Primary Sjogrens). MP release may occur within different vascular sites across these disease groups (macrovascular and microvascular). The association between circulating MP levels and objective assessment of macro- and microvascular dysfunction within these disease areas suggests that MPs might have a useful role as novel circulating biomarkers of vascular disease within the CTDs.</p

An allosteric cross-talk between the activation loop and the ATP binding site regulates the activation of Src kinase

Phosphorylation of the activation loop is a fundamental step in the activation of most protein kinases. In the case of the Src tyrosine kinase, a prototypical kinase due to its role in cancer and its historic importance, phosphorylation of tyrosine 416 in the activation loop is known to rigidify the structure and contribute to the switch from the inactive to a fully active form. However, whether or not phosphorylation is able per-se to induce a fully active conformation, that efficiently binds ATP and phosphorylates the substrate, is less clear. Here we employ a combination of solution NMR and enhanced-sampling molecular dynamics simulations to fully map the effects of phosphorylation and ATP/ADP cofactor loading on the conformational landscape of Src tyrosine kinase. We find that both phosphorylation and cofactor binding are needed to induce a fully active conformation. What is more, we find a complex interplay between the A-loop and the hinge motion where the phosphorylation of the activation-loop has a significant allosteric effect on the dynamics of the C-lobe

Effect of Greenhouse Film Cover on the Development of Fungal Diseases on Tomato (Solanum lycopersicum L.) and Pepper (Capsicum annuum L.) in a Mediterranean Protected Crop

Greenhouses on the Mediterranean coast mainly use plastic materials as their cover. The influence of light exerted by these materials directly affects the crops by modifying the environment in which they develop. The aim of this study was to analyze the effect of the use of two plastic films in an experimental greenhouse on the development of fungal diseases in two spring–summer crop cycles: tomato (Solanum lycopersicum L.) from february to July 2021 and pepper (Capsicum annuum L.) from February to July 2022. The study was carried out in Almeria (Spain) in a multispan greenhouse divided transversely into two sectors by a polyethylene sheet. A commercial film was installed in the east sector (90% of transmissivity and 55% diffusivity) and an experimental film was installed in the west sector (85% of transmissivity and 60% diffusivity). In addition, the effect of the yield and quality of the harvested fruit was determined. In this study, two diseases were established naturally on the crop: (i) powdery mildew (Leveillula taurica) in both the tomato and the pepper crop cycles and (ii) early blight (Alternaria solani) in the tomato. The analyses of both diseases showed that the areas of the greenhouse that used the plastic cover, which presented a lower sunlight transmissivity, showed higher levels of disease than the areas that used the plastic cover that allowed greater transmissivity of light within the greenhouse, differing statistically in some phases of the crop. The marketable yield was 4.2% (for tomato) and 3.1% (for pepper) higher in the sector with the experimental film with high transmissivity. For both crops, the quality of the fruits did not show statistically significant difference

Impact of compacted bentonite microbial community on the clay mineralogy and copper canister corrosion: a multidisciplinary approach in view of a safe Deep Geological Repository of nuclear wastes

Deep Geological Repository (DGR) is the preferred option for the final disposal of high-level radioactive waste. Microorganisms could affect the safety of the DGR by altering the mineralogical properties of the compacted bentonite or inducing the corrosion of the metal canisters. In this work, the impact of physicochemical parameters (bentonite dry density, heat shock, electron donors/acceptors) on the microbial activity, stability of compacted bentonite and corrosion of copper (Cu) discs was investigated after one-year anoxic incubation at 30 ºC. No-illitization in the bentonite was detected confirming its structural stability over 1 year under the experimental conditions. The microbial diversity analysis based on 16 S rRNA gene Next Generation Sequencing showed slight changes between the treatments with an increase of aerobic bacteria belonging to Micrococcaceae and Nocardioides in heat-shock tyndallized bentonites. The survival of sulfate-reducing bacteria (the main source of Cu anoxic corrosion) was demonstrated by the most probable number method. The detection of CuxS precipitates on the surface of Cu metal in the bentonite/Cu metal samples amended with acetate/lactate and sulfate, indicated an early stage of Cu corrosion. Overall, the outputs of this study help to better understand the predominant biogeochemical processes at the bentonite/Cu canister interface upon DGR closure

Relativistic quantum mechanics of a Dirac oscillator

The Dirac oscillator is an exactly soluble model recently introduced in the context of many particle models in relativistic quantum mechanics. The model has been also considered as an interaction term for modelling quark confinement in quantum chromodynamics. These considerations should be enough for demonstrating that the Dirac oscillator can be an excellent example in relativistic quantum mechanics. In this paper we offer a solution to the problem and discuss some of its properties. We also discuss a physical picture for the Dirac oscillator's non-standard interaction, showing how it arises on describing the behaviour of a neutral particle carrying an anomalous magnetic moment and moving inside an uniformly charged sphere.Comment: 19 pages, 1 figur