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The knowledge of how magnetization looks inside a ferromagnet is often hindered by the limitations of the available experimental methods which are sensitive only to the surface regions or limited in spatial resolution. Here we report a vector tomographic reconstruction based on soft X-ray transmission microscopy and magnetic dichroism data, which has allowed visualizing the three-dimensional magnetization in a ferromagnetic thin film heterostructure. Different non-trivial topological textures have been resolved and the determination of their topological charge has allowed us to identify a Bloch point and a meron-like texture. Our method relies only on experimental data and might be of wide application and interest in 3D nanomagnetism. Although magnetic tomography has been used in the past to determine the 3D magnetization of materials its application to thin films remains challenging. Here the authors reconstruct the magnetization of a thin film, enabling the measurement of topological charges of magnetic singularities.

In this study, we demonstrate that the expression in tumorigenic epidermal cells of a catalytically inactive form of CYLD (CYLD C/S ) that mimics the identified mutations of cyld in human tumors and competes with the endogenous CYLD results in enhanced cell proliferation and inhibition of apoptosis; it also stimulates cell migration and induces the expression of angiogenic factors, including vascular endothelial growth factor-A. Altogether, these characteristics indicate an increased oncogenicity of the tumorigenic epidermal CYLD C/S mutant cells in vitro. Moreover, we show the increase in malignancy of epidermal squamous cell carcinomas that express the CYLD C/S transgene in an in vivo xenograft model. Tumors carrying the mutated CYLD C/S exhibit a fast growth, are poorly differentiated and present a robust angiogenesis. CYLD C/S tumors are also characterized by their elevated proliferation rate and decreased apoptosis. In contrast with previous studies showing the development of benign tumors by mutations in the CYLD gene, here we provide evidence that the occurrence of mutations in the CYLD gene in tumorigenic epidermal cells (carrying previous mutations) increases the aggressiveness of carcinomas, mainly through enhancement of the expression of angiogenic factors, having therefore a key role in epidermal cancer malignancy.

Advances in nanoscale magnetism increasingly require characterization tools providing detailed descriptions of magnetic configurations. Magnetic transmission X-ray microscopy produces element specific magnetic domain images with nanometric lateral resolution in films up to ∼100 nm thick. Here we present an imaging method using the angular dependence of magnetic contrast in a series of high resolution transmission X-ray microscopy images to obtain quantitative descriptions of the magnetization (canting angles relative to surface normal and sense). This method is applied to 55–120 nm thick ferromagnetic NdCo 5 layers (canting angles between 65° and 22°), and to a NdCo 5 film covered with permalloy. Interestingly, permalloy induces a 43° rotation of Co magnetization towards surface normal. Our method allows identifying complex topological defects (merons or ½ skyrmions) in a NdCo 5 film that are only partially replicated by the permalloy overlayer. These results open possibilities for the characterization of deeply buried magnetic topological defects, nanostructures and devices. Transmission X-ray microscopy allows for the imaging of magnetic domains in thin film materials. Here, the authors exploit the angular dependence of the magnetic contrast to extract out-of-plane canting angles of stripe domains and topological defects in NdCo 5 films buried under a NiFe layer.

CYLD is a gene mutated in familial cylindromatosis and related diseases, leading to the development of skin appendages tumors. Although the deubiquitinase CYLD is a skin tumor suppressor, its role in skin physiology is unknown. Using skin organotypic cultures as experimental model to mimic human skin, we have found that CYLD acts as a regulator of epidermal differentiation in humans through the JNK signaling pathway. We have determined the requirement of CYLD for the maintenance of epidermal polarity, keratinocyte differentiation and apoptosis. We show that CYLD overexpression increases keratinocyte differentiation while CYLD loss of function impairs epidermal differentiation. In addition, we describe the important role of CYLD in the control of human non-melanoma skin cancer progression. Our results show the reversion of the malignancy of human squamous cell carcinomas that express increased levels of CYLD, while its functional inhibition enhances the aggressiveness of these tumors which progress toward spindle cell carcinomas. We have found that the mechanisms through which CYLD regulates skin cancer progression include the control of tumor differentiation, angiogenesis and cell survival. These findings of the role of CYLD in human skin cancer prognosis make our results relevant from a therapeutic point of view, and open new avenues for exploring novel cancer therapies.

During the initial stages of copper electrodeposition onto a thin seed layer, a nonuniform potential distribution arises, resulting in local variations in growth rate and deposit morphology. Early stages of morphology evolution during copper electrodeposition are of practical importance but have not been well studied. Here, a new multiscale approach is developed for numerical simulation of the effect of a macroscopic potential distribution along a seed layer on microscopic local roughness evolution. The key contribution is a generic method for coupling multiple computer codes, and the demonstration of its use. The macroscopic code passes the local potential at ten points along the seed layer to ten kinetic Monte Carlo codes, each of which simulates additive-free copper electrodeposition and roughness evolution on an initially flat surface. Periodically, each Monte Carlo code computes the local film thickness and passes it back to the resistance code, which updates the potential distribution for the next iteration. Results are obtained for a wide range of parameter space including both constant-potential and constant-current operation. A confirmation procedure was developed to verify that the multiscale approach (using small Monte Carlo simulation domains with periodic boundary conditions) does not significantly alter the physical accuracy of the simulations. [PUBLICATION ABSTRACT]

Sophisticated data-distribution schemes and recent developments in sensors and instruments that can monitor the lower kilometers of the atmosphere at high levels of resolution have rapidly expanded the quantity of information available to mesoscale meteorology. The myLEAD personalized information-management tool helps geoscience users make sense of this vastly expanded information space. MyLEAD extends the general globus metadata catalog service and leverages a well-known general and extensible schema. Its orientation makes it an active player in large-scale distributed computation environments characterized by interacting grid and Web services.

Amorphous Nd-Co films deposited by DC-magnetron sputtering presented perpendicular magnetic anisotropy (PMA) with energies, KN, of the order of 106 erg/cc at RT. To understand the origin of their PMA, we measured the orbital and spin magnetic moments in Co and Nd by XMCD at the Co L3,2 and Nd M5,4 edges in two kinds of samples of similar thickness (30 nm) and composition: one compositionally modulated Nd/Co film (CM) with strong PMA (KN ~107 erg/cc at 10 K) and a homogenous alloy (A) with not strong enough PMA to see stripe domains for such thickness. The XMCD analysis evidenced the significant role of Nd in the PMA of these films.

Domain wall propagation has been studied in perpendicular anisotropy CoPt multilayers patterned by e-beam lithography into 5 μm wide wires. Positive and negative peaks appear in time resolved magnetoresistance curves, associated to the different directions of domain wall propagation along the wires. The field dependence of domain wall velocity is well described by a creep model of a 1D wall in the presence of weak disorder with critical exponent μ=1/4.

Micromagnetic simulations have been performed in uniaxial magnetic films with 2D array of asymmetric arrow shape holes. In order to understand the asymmetric pinning potential created by the holes, different boundary geometries conditions are used on the simulations. The depinning fields for forward and backward domain wall propagation have been calculated by the analysis of the energy landscapes as a function of the domain wall position. Domain wall depinning occurs preferentially at the free ends of the domain wall at the film boundaries. We have found that the domain wall propagation is different at the top/bottom boundaries of the simulated film which can be understood in terms of the magnetostatic energy and the chirality of the domain wall.