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A self-consistent framework to study magnetic fields with strong gravitational lensing and polarized radio sources
Ndiritu, S.W.; Vegetti, S.; Powell, D.M.; McKean, John P. (Oxford University Press, 2025-04)
We introduce a unified approach that, given a strong gravitationally lensed polarized source, self-consistently infers its complex surface brightness distribution and the lens galaxy mass–density profile, magnetic field and electron density from interferometric data. The method is fully Bayesian, pixellated, and three-dimensional: the source light is reconstructed in each frequency channel on a Delaunay tessellation with a magnification-adaptive resolution. We tested this technique using simulated interferometric observations with a realistic model of the lens, for two different levels of source polarization and two different lensing configurations. For all data sets, the presence of a Faraday rotating screen in the lens is supported by the data with strong statistical significance. In the region probed by the lensed images, we can recover the rotation measure and the parallel component of the magnetic field with an average error between 0.6 and 11 rad m −2 and 0.3 and 3nG, respectively. Given our choice of model, we find the electron density is the least well-constrained component due to a degeneracy with the magnetic field and disc inclination. The background source total intensity, polarization fraction, and polarization angle are inferred with an error between 4 and 10 per cent, 15 and 50 per cent, and 1–12 de g, respectively. Our analysis shows that both the lensing configuration and the intrinsic model degeneracies play a role in the quality of the constraints that can be obtained.
A grand-design spiral galaxy with an ordered magnetic field at redshift 2.6 as resolved with ALMA and gravitational lensing
De Roo, W.; Vegetti , S.; Powell , D.M.; Ndiritu, S.W.; Pakmor, R.; McKean, John P. (Oxford University Press, 2025-06)
Magnetic fields play an important role in the evolution of galaxies and in shaping the dynamics of their interstellar medium. However, the formation history of magnetic fields from initial seed-fields to well-ordered systems is not clear. Favoured scenarios include a turbulent dynamo that amplifies the field, and a mean-field dynamo that organizes it. Such a model can be tested through observing the magnetic-field structure of galaxies in the early Universe given the relative formation time-scales involved. Here, we combine the high angular resolution of the Atacama Large Millimetre Array (ALMA) and gravitational lensing to resolve the magnetic field structure of a 4 kpc in extent grand-design spiral when the Universe was just 2.6 Gyr old. We find that the spiral arm structure, as traced by the heated dust emission, is coincident with the linearly polarized emission, which is consistent with a highly ordered magnetic field. The time-scale needed to produce such an ordered field is likely within at least several rotations of the disc. Our study highlights the importance of combining the long baselines of ALMA and gravitational lensing to resolve the structure of galaxies at cosmologically interesting epochs.
A first glimpse at the MeerKAT DEEP2 field at S-band
Ranchod, S.; Wagenveld, J.D.; Klockner, H.-R.; Wucknitz, O.; Deane, Roger; Sridhar, S.S.; Barr, E.; Buchner, S.; Camilo, F.; Damas-Segovia, A.; Kasemann, C.; Kramer , M.; Legodi, L.S.; Mao, S.A.; Menten, K.; Rammala, I.; Rugel, M.R.; Wieching, G. (Oxford University Press, 2025-02)
Please read abstract in the article.
The common concept of anticooperativity among molecules is fundamentally flawed, based on novel and unified molecular-wide and electron density (MOWeD) concept of chemical bonding
Cukrowski, Ignacy; Zaaiman, Stéfan; Hussain, Shahnawaz (MDPI, 2025-04-27)
A non-linear (non-additive) increase in stability of hexamers follows an increase in the total number of (i) aad (a double proton acceptor) plus add (a double proton donor) waters commonly linked with anticooperativity and (ii) the total number of intermolecularly delocalized electrons (intermolNdeloc) in the 3D space occupied by a hexamer. Subsequently, we obtained nearly a perfect linear correlation between increase in the cluster stability and intermolNdeloc. Individual water molecules that act as either aad or add (i) delocalize the largest number of electrons throughout a cluster; (ii) are involved in the strongest attractive, hence energy-stabilizing intermolecular interaction with the remaining five waters; (iii) have the most significant quantum component of the intermolecular interaction energy and (iv) relative to six non-interacting water molecules, stabilize a hexamer the most, as quantified by a purposely derived mol-FAMSEC energy term. Clearly, the all-body approach used in the unified, molecular-wide and electron density (MOWeD)-based concept of chemical bonding contradicts the commonly accepted view that aad and add water molecules are involved in anticooperativity in 3D water hexamers. Consequently, we propose here a general definition of cooperativity that should be applicable to any n-membered molecular cluster, namely the quantifiable, classical physics- and quantum-based cooperativity phenomenon is synonymous with the intermolecular all-body delocalization of electrons, leading to the increase in stability of individual molecules on an n-membered cluster formation.
CD44 variant expression in follicular cell-derived thyroid cancers : implications for overcoming multidrug resistance
Mosoane, Benny; McCabe, Michelle; Jackson, Brandon Spencer; Dlamini, Zodwa (MDPI, 2025-04-24)
Thyroid cancer (TC) is a significant global health issue that exhibits notable heterogeneity in incidence and outcomes. In low-resource settings such as Africa, delayed diagnosis and limited healthcare access exacerbate mortality rates. Among follicular cell-derived thyroid cancers—including papillary (PTC), follicular (FTC), anaplastic (ATC), and poorly differentiated (PDTC) subtypes—the role of CD44 variants has emerged as a critical factor influencing tumor progression and multidrug resistance (MDR). CD44, a transmembrane glycoprotein, and its splice variants (CD44v) mediate cell adhesion, migration, and survival, contributing to cancer stem cell (CSC) maintenance and therapy resistance. Differential expression patterns of CD44 isoforms across TC subtypes have shown diagnostic, prognostic, and therapeutic implications. Specifically, CD44v6 expression in PTC has been correlated with metastasis and aggressive tumor behavior, while in FTC, its expression aids in distinguishing malignant from benign lesions. Furthermore, CD44 contributes to MDR through enhanced drug efflux via ABC transporters, apoptosis evasion, and CSC maintenance via the Wnt/β-catenin and PI3K/Akt pathways. Targeted therapies against CD44 such as monoclonal antibodies, hyaluronic acid-based nanocarriers, and gene-editing technologies hold promise in overcoming MDR. However, despite the mounting evidence supporting CD44-targeted strategies in various cancers, research on this therapeutic potential in TC remains limited. This review synthesizes existing knowledge on CD44 variant expression in follicular cell-derived thyroid cancers and highlights potential therapeutic strategies to mitigate MDR, particularly in high-burden regions, thereby improving patient outcomes and survival.