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Introduction In this study we characterized disease progression over 48 weeks among boys receiving deflazacort vs prednisone/prednisolone placebo arm treatment in two recent Duchenne muscular dystrophy (DMD) clinical trials. Methods Ambulatory boys with DMD receiving placebo in the phase 3 ataluren (N = 115) and tadalafil (N = 116) trials were included. The trials required at least 6 months of prior corticosteroid use and stable baseline dosing. Associations between corticosteroid use and 48‐week changes in ambulatory function were estimated using mixed models. Adjusted differences between corticosteroid groups were pooled in a meta‐analysis. Results In the meta‐analysis, deflazacort‐treated patients vs prednisone/prednisolone‐treated patients experienced, on average, lower declines of 28.3 meters on 6‐minute walk distance (95% confidence interval [CI], 5.7, 50.9; 2.9 seconds on rise from supine [95% CI, 0.9, 4.9 seconds]; 2.3 seconds on 4‐stair climb [95% CI, 0.5, 4.1 seconds]; and 2.9 [95% CI, 0.1, 5.8] points on the North Star Ambulatory Assessment linearized score). Discussion Deflazacort‐treated patients experienced significantly lower functional decline over 48 weeks.

Aim:Assess the totality of efficacy evidence for ataluren in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD).Materials & methods:Data from the two completed randomized controlled trials (ClinicalTrials.gov: NCT00592553; NCT01826487) of ataluren in nmDMD were combined to examine the intent-to-treat (ITT) populations and two patient subgroups (baseline 6-min walk distance [6MWD] >= 300-= 300-= 300

ObjectiveTo evaluate the relationship between deficit in digit span and genotype in nonsense mutation (nm) Duchenne muscular dystrophy (DMD) (nmDMD).MethodsWe investigated the relationship between normalized digit-span forward (d-sf) and digit-span backward (d-sb) scores to the location of nmDMD mutations in 169 participants ≥5 to ≤20 years who participated in a phase 2b clinical trial. Because alternative promoters are found upstream of DMD exons 30, 45, and 63, we correlated d-sf and d-sb to the specific nmDMD mutation location.ResultsParticipants with nm downstream of exon 30, downstream of exon 45, and downstream of exon 63 had significantly lower normalized d-sf scores (p < 0.0001). Participants with nm downstream of exon 45 in addition had significantly lower normalized d-sb score (p < 0.04). There was no significant difference in the normalized d-sb score in participants with mutations upstream or downstream of DMD exon 30 or upstream or downstream of DMD exon 63.ConclusionOur data provide evidence that specific cognitive deficits correlate to genotype in individuals with nmDMD, highlighting the critical role of brain-specific dystrophin isoforms in the neurobiological manifestations of this disease.Clinicaltrials.gov identifierNCT02090959.

Little is known about the characteristics and treatments of patients with severe asthma across Europe, but both are likely to vary. This is the first study in the European Respiratory Society Severe Heterogeneous Asthma Research collaboration, Patient-centred (SHARP) Clinical Research Collaboration and it is designed to explore these variations. Therefore, we aimed to compare characteristics of patients in European severe asthma registries and treatments before starting biologicals.This was a cross-sectional retrospective analysis of aggregated data from 11 national severe asthma registries that joined SHARP with established patient databases.Analysis of data from 3236 patients showed many differences in characteristics and lifestyle factors. Current smokers ranged from 0% (Poland and Sweden) to 9.5% (Belgium), mean body mass index ranged from 26.2 (Italy) to 30.6 kg·m−2 (the UK) and the largest difference in mean pre-bronchodilator forced expiratory volume in 1 s % predicted was 20.9% (the Netherlands versus Hungary). Before starting biologicals patients were treated differently between countries: mean inhaled corticosteroid dose ranged from 700 to 1335 µg·day−1 between those from Slovenia versus Poland when starting anti-interleukin (IL)-5 antibody and from 772 to 1344 µg·day−1 in those starting anti-IgE (Slovenia versus Spain). Maintenance oral corticosteroid use ranged from 21.0% (Belgium) to 63.0% (Sweden) and from 9.1% (Denmark) to 56.1% (the UK) in patients starting anti-IL-5 and anti-IgE, respectively.The severe asthmatic population in Europe is heterogeneous and differs in both clinical characteristics and treatment, often appearing not to comply with the current European Respiratory Society/American Thoracic Society guidelines definition of severe asthma. Treatment regimens before starting biologicals were different from inclusion criteria in clinical trials and varied between countries.

Drug development for rare diseases is challenged by small populations and limited data. This makes development of clinical trial protocols difficult and contributes to the uncertainty around whether or not a potential therapy is efficacious. The use of data standards to aggregate data from multiple sources, and the use of such integrated databases to develop statistical models can inform protocol development and reduce the risks in developing new therapies. Achieving regulatory endorsement of such models through defined pathways at the US Food and Drug Administration and European Medicines Authority allows such tools to be used by the drug development community for defined contexts of use without further need for discussion of the underlying model(s). The Duchenne Regulatory Science Consortium (D-RSC) has brought together multiple stakeholders to develop a clinical trial simulation tool for Duchenne muscular dystrophy using such an approach. Here we describe the work of D-RSC as an example of how such an approach may be effective at reducing uncertainty in drug development for rare diseases, and thus bringing effective therapies to patients faster.

In low-collisionality scenarios exhibiting mitigation of edge localized modes (ELMs), stable ideal kink modes at the edge are excited by externally applied magnetic perturbation (MP)-fields. In ASDEX Upgrade these modes can cause three-dimensional (3D) boundary displacements up to the centimeter range. These displacements have been measured using toroidally localized high resolution diagnostics and rigidly rotating n = 2 MP-fields with various applied poloidal mode spectra. These measurements are compared to non-linear 3D ideal magnetohydrodynamics (MHD) equilibria calculated by VMEC. Comprehensive comparisons have been conducted, which consider for instance plasma movements due to the position control system, attenuation due to internal conductors and changes in the edge pressure profiles. VMEC accurately reproduces the amplitude of the displacement and its dependencies on the applied poloidal mode spectra. Quantitative agreement is found around the low field side (LFS) midplane. The response at the plasma top is qualitatively compared. The measured and predicted displacements at the plasma top maximize when the applied spectra is optimized for ELM-mitigation. The predictions from the vacuum modeling generally fails to describe the displacement at the LFS midplane as well as at the plasma top. When the applied mode spectra is set to maximize the displacement, VMEC and the measurements clearly surpass the predictions from the vacuum modeling by a factor of four. Minor disagreements between VMEC and the measurements are discussed. This study underlines the importance of the stable ideal kink modes at the edge for the 3D boundary displacement in scenarios relevant for ELM-mitigation., 22 pages, 12 figure, for submission to nuclear fusion

209th ENMC International Workshop: Outcome Measures and Clinical Trial Readiness in Spinal Muscular Atrophy 7–9 November 2014, Heemskerk, The Netherlands Richard Finkel *, Enrico Bertini , Francesco Muntoni , Eugenio Mercuri d on behalf of the ENMC SMA Workshop Study Group 1 a Nemours Children’s Hospital, Orlando, USA b UCL Institute of Child Health, Dubowitz Neuromuscular Centre, London, UK c Bambino Gesu Children’s Research Hospital, Rome, Italy d Pediatric Neurology Unit, Catholic University, Rome, Italy Received 2 March 2015

The neutralization of a single He2+ ion near a Ir surface leads to the emission of an electron pair. Via coincidence spectroscopy we give evidence that a sizable amount of these electron pairs originate from a correlated single step neutralization of the ion involving a total of four electrons from the metal. These correlated electron pairs cannot be explained in the common picture of two consecutive and independent neutralization steps. We infer a characteristic time scale for the correlated electron dynamics in the metal of 40–400 as.

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al., The atomic structure of ultrathin iron films deposited on the (0001) surface of the topological insulator Bi2Se3 is analyzed by surface x-ray absorption spectroscopy. Iron atoms deposited on a Bi2Se3 (0001) surface kept at 160 K substitute bismuth atoms within the first quintuple layer. Iron atoms are neighbored by six selenium atoms at a distance in the 2.4 Å range indicating substantial atomic relaxations. Mild annealing up to 520 K leads to the formation of α-FeSe, characterized by a local order extending up to the sixth shell (5.80 Å). Ab initio calculations predict a noncollinear magnetic ordering with a transition temperature of 3.5-10 K depending on the iron concentration and the number of the layers in which Fe is located., We acknowledge financial support from DFG through priority program SPP1666 (Topological Insulators). M.M.O. and E.V.C. thank the Tomsk State University Academic D. I. Mendeleev Fund Program (Research Grant No. 8.1.05.2015). Partial support by the Saint Petersburg State University Project No. 11.50.202.2015 is also acknowledged.

Mutations in TPM3, encoding Tpm3.12, cause a clinically and histopathologically diverse group of myopathies characterized by muscle weakness. We report two patients with novel de novo Tpm3.12 single glutamic acid deletions at positions ΔE218 and ΔE224, resulting in a significant hypercontractile phenotype with congenital muscle stiffness, rather than weakness, and respiratory failure in one patient.The effect of the Tpm3.12 deletions on the contractile properties in dissected patient myofibers was measured. We used quantitative in vitro motility assay to measure Ca(2+) sensitivity of thin filaments reconstituted with recombinant Tpm3.12 ΔE218 and ΔE224.Contractility studies on permeabilized myofibers demonstrated reduced maximal active tension from both patients with increased Ca(2+) sensitivity and altered cross-bridge cycling kinetics in ΔE224 fibers. In vitro motility studies showed a two-fold increase in Ca(2+) sensitivity of the fraction of filaments motile and the filament sliding velocity concentrations for both mutations.These data indicate that Tpm3.12 deletions ΔE218 and ΔE224 result in increased Ca(2+) sensitivity of the troponin-tropomyosin complex, resulting in abnormally active interaction of the actin and myosin complex. Both mutations are located in the charged motifs of the actin-binding residues of tropomyosin 3, thus disrupting the electrostatic interactions that facilitate accurate tropomyosin binding with actin necessary to prevent the on-state. The mutations destabilize the off-state and result in excessively sensitized excitation-contraction coupling of the contractile apparatus. This work expands the phenotypic spectrum of TPM3-related disease and provides insights into the pathophysiological mechanisms of the actin-tropomyosin complex.

Background Nintedanib (formerly known as BIBF 1120) is an intracellular inhibitor that targets multiple tyrosine kinases. A phase 2 trial suggested that treatment with 150 mg of nintedanib twice daily reduced lung-function decline and acute exacerbations in patients with idiopathic pulmonary fibrosis. Methods We conducted two replicate 52-week, randomized, double-blind, phase 3 trials (INPULSIS-1 and INPULSIS-2) to evaluate the efficacy and safety of 150 mg of nintedanib twice daily as compared with placebo in patients with idiopathic pulmonary fibrosis. The primary end point was the annual rate of decline in forced vital capacity (FVC). Key secondary end points were the time to the first acute exacerbation and the change from baseline in the total score on the St. George’s Respiratory Questionnaire, both assessed over a 52-week period. Results A total of 1066 patients were randomly assigned in a 3:2 ratio to receive nintedanib or placebo. The adjusted annual rate of change in FVC was −114.7 ml with nintedanib versus −239.9 ml with placebo (difference, 125.3 ml; 95% confidence interval [CI], 77.7 to 172.8; P

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al., We present a surface x-ray analysis of the atomic structure of the (0001) surface of the topological insulator Bi2Se3, which was grown as a single crystal and as an ultrathin film on Si(111) using molecular beam epitaxy (MBE). In general we find that the top Se-Bi layer spacing is expanded between 2% and 17% relative to the bulk, while deeper layers and the first van der Waals gap are unrelaxed. The top layer expansion is directly related to the amount of surface contamination by carbon and oxygen. The near-surface structures of the single crystal and the MBE-grown thin film differ in the degree of (static) disorder: for the former an overall Debye parameter (B) per quintuple layer (QL) of 5Å2 is found to decrease slowly with depth. MBE-grown Bi2Se3 films exhibit the opposite scenario, characterized by an increase in B from about 10Å2 for the topmost QL to values of B=20-40 Å2 for the fourth QL. This is attributed to the lattice misfit to the Si(111) surface. Ab initio calculations reveal carbon to act as an n-dopant, while the first interlayer spacing expansion induces a shift of the Dirac point towards the Bi2Se3 bulk conduction band minimum., We acknowledge the financial support from the DFG through priority program SPP1666 (Topological Insulators).

Resumen del trabajo presentado al Moscow International Symposium on Magnetism (MISM), celebrado en Moscú (Rusia) del 29 de junio al 3 de julio de 2014., Support by DFG through SPP1666 is acknowledged.

The structural and magnetic properties of FexMn1-x alloy thin films deposited on Cu(001) and on Co/Cu(001) are investigated. A layer-by-layer growth mode of the alloy films in a large range of concentration is deduced from the presence of regular oscillations in medium-energy electron-diffraction intensity. Low-energy electron-diffraction experiments reveal that Fe50Mn50 films keep the fcc structure when growing on Cu(001) and on Co/Cu(001). Magneto-optic Kerr effect is used to study the magnetic properties of Co/FeMn bilayers. A temperature-dependent increase in the coercive field of the Co film, when the thickness of the adjacent FeMn film exceeds a certain value, is related to the antiferromagnetic state of the FexMn1-x alloy.

We combine X-ray magnetic circular dichroism (XMCD) and photoelectron emission microscopy to obtain locally resolved magnetic information on a microscopic scale. Scanning the photon energy across elemental absorption edges and recording microscopic images of the local secondary electron intensity for both photon helicities at each photon energy step allows to analyze local XMCD spectra at any position of the imaged area of the sample. With the help of magnetic sum-rules local quantitative information about magnetic moments can be extracted from such microspectroscopic measurements. The full power of XMCD as a spectroscopic tool is so maintained, while microscopic spatial resolution is added.

The magnetic phases of 0-6 atomic monolayers (ML) Ni/0-14 ML Fe/6 ML Co/Cu(001) trilayer crossed double wedges are studied by the combination of photoelectron emission microscopy and X-ray magnetic circular dichroism spectroscopy at the Fe L2,L3 edges. This microspectroscopic technique allows the extraction of local quantitative magnetic information. The presence of three magnetically different thickness regions of Fe with effective spin moments per atom of 2.5 mu(B) (below approximate to 3.5 ML), 0.7 mu(B) (approximate to 3.5-11 ML), and 2.0 mu(B) (above approximate to 11 ML) is confirmed. At 7-9 ML thickness, the value of 0.7 mu(B) is consistent with a ferromagnetic Fe surface layer on top of non-ferromagnetic layers. The ratio of orbital to effective spin moment varies between 0.05 for very thin Fe films and 0.15 for thicker films, if correction of saturation effects is taken into account. Images of the magnetic circular dichroism asymmetry at the Ni and Co L-3 edges show that at 5.5 ML Fe thickness the Ni and Co magnetizations have opposite orientations, pointing towards antiferromagnetic coupling across the Fe layer.

Photoelectron emission microscopy is combined with soft x-ray magnetic circular dichroism (XMCD) absorption spectroscopy to obtain local element-resolved quantitative magnetic properties with microscopic resolution. This is applied to study 0-14 ML Fe wedges with a slope of 0.055 ML/mu m on 6 ML Co/Cu(001). Local XMCD spectra at the Fe L-2,L-3 edge confirm the presence of three magnetically different thickness regions of Fe with effective spin moments of 2.5 mu(B) (0-4.5 ML), 0.7 mu(B) (4.5-11 ML), and 1.8 mu(B) (> 11 ML). The value of 0.7 mu(B) in the second phase is consistent with an fcc Fe phase containing nonferromagnetic layers underneath a ferromagnetic surface.

The benefit of combining soft X-ray magnetic circular dichroism and photoelectron microscopy is demonstrated by applying this combination to the observation of the magnetic domain structures of rectangular microstructures. The size and aspect-ratio dependence of the transformation of the domain structures by magnetic field pulses is investigated. The switching mechanism, which is very important in the application to magnetic storage, is discussed in terms of transformation between saturated and vortex domain structures.

Magnetization induced optical second harmonic generation (MSHG) in combination with the magneto-optical Kerr effect (MOKE) was used to study thin Co films and Cu/Co multilayers of thicknesses between 1 and 20 monolayers (ML) grown on a Cu(001) substrate. From the different dependence of MSHG and MOKE on Co film thickness we get direct information about the interface sensitivity of MSHG. Modifying the vacuum/Co interface by gas adsorption yields the relative contributions of the vacuum/Co and the Co/Cu(001)-substrate interfaces. Both MSHG and MOKE data can be accurately described by a multiple reflection model.

The scanning electron microscope with spin polarization analysis of secondary electrons has been proven to be a powerful tool for studying magnetic microstructures. Secondary electrons created at the surface of a ferromagnet are spin-polarized and contain information about the sample magnetization and its orientation. The combination of a spin polarization analyzer with a scanning electron microscope yields an unique apparatus for probing magnetic properties on a very small lateral scale. The magnetic resolution of < 40 nm is demonstrated. This type of microscope provides high magnetic contrast, while the surface morphology is strongly or even totally suppressed. The capability of studying magnetic properties of semi- infinite samples as well as in ultrathin films is demonstrated with a Fe(lOO) single crystal, video tape, CoCr perpendicular recording medium and ultrathin cobalt films.

We report on the development of a Scanning Low Energy Diffraction Microscope, operating in the range of 250 to 1000 eV primary energy. By discriminating against inelastically scattered electrons, low energy electron diffraction (LEED) patterns are obtained from areas of about 100 nm in size. By selecting a particular diffracted beam dark-field images of the surface structure are obtained in the scanning mode. Examples are given for polycrystalline Si and clean and adsorbate covered Si (111) surfaces.

Calpainopathy is an autosomal-recessive limb girdle muscular dystrophy (LGMD2A) characterized by selective atrophy and weakness of proximal limb girdle muscles. The clinical phenotype of the disease is highly variable inter-familial, but little is known about intra-familial variability. This study reports the phenotypic variability in eight sibling pairs with genetically proven LGMD2A. Although siblings with identical mutations were often similarly affected, in some families the age of onset and the clinical course varied considerably.

Age research in vertebrates is often limited by the longevity of available models. The teleost fish Nothobranchius furzeri has an exceptionally short lifespan with 3.5 months for the laboratory strain GRZ and about 6 months for the wild-derived strain MZM-0403. Here we have investigated telomere length in muscle and skin tissue of young and old fish of both strains using different methods. We found age-dependent telomere shortening in the MZM-0403 strain with the longer lifespan, whereas the short-lived GRZ strain showed no significant telomere shortening with advanced age. Sequencing of the two main telomerase genes Tert and Terc revealed that both genes are highly conserved between the N. furzeri strains while there is little conservation to other fish species and humans. Both genes are ubiquitously expressed in N. furzeri and expression levels of Tert and Terc correlate with telomerase activity in a tissue-specific manner. Unexpectedly, the expression level of Tert is increased in aged muscle and skin tissue of MZM-0403 suggesting that telomeres shorten upon ageing despite increased Tert expression and hence high telomerase activity. We further conclude that the extremely short lifespan of the GRZ strain is not caused by diminished telomerase activity or accelerated telomere shortening.

The as-grown magnetic domain patterns of epitaxial single-crystalline Co/FeMn bilayers and Co/Cu/FeMn trilayers were investigated by magnetic circular dichroism domain imaging using a photoelectron emission microscope. Small domains were observed when Co was deposited directly on top of antiferromagnetic FeMn films. On inserting a Cu spacer layer between the ferromagnetic Co layer and the antiferromagnetic FeMn layer, the as-grown domain size increases continuously with increasing Cu layer thickness, which is attributed to the decrease of the interlayer exchange coupling between the Co and FeMn layers. Domain images of the Co layer acquired after applying different external magnetic fields confirm the relation between as-grown domain size and interface coupling to the antiferromagnetic FeMn layer across the non-magnetic Cu spacer layer. It is found that a field of 44 Oe is sufficient to annihilate most small domains in the area where Co and FeMn are coupled through the Cu wedge, while it has no effect on the domain configuration of a Co/FeMn bilayer. By analysing the dependence of the average domain size of the Co layer on the Cu thickness in terms of interface coupling between the Co and FeMn layers across the Cu layer, the apparent estimated coupling energy was found to be different for different Co thickness. This is ascribed to kinetic barriers hindering the formation of larger domains from smaller ones.

By using a photoemission electron microscope in combination with X-ray magnetic circular dichroism, the domain configuration in a single crystalline Co film exchange coupled to an Fe 50 Mn 50 film is obtained. The effect of the ferromagnetic/antiferromagnetic interaction is observed to be different in Co domains with different magnetization direction, establishing the fact that the exchange bias is locally set by the magnetization of the ferromagnetic layer, without external field.

The micromagnetic properties of a Ni film in a Cu/Ni crossed-wedge on Cu(0 0 1) are investigated by a combination of photoelectron emission microscopy and X-ray magnetic circular dichroism. Two spin-reorientation transitions (SRT) from in-plane to perpendicular to the film plane and back to in-plane were observed with increasing Ni thickness. Whereas no clear Cu thickness dependence of the former SRT has been observed, the latter strongly depends on Cu thickness, and is shifted to thinner Ni thicknesses by increasing Cu overlayer thickness. Furthermore, the size and the shape of the ferromagnetic domain structure in the perpendicular magnetization region also depend on Cu thickness. The average domain size decreases with increasing Ni thickness near the second SRT line. It is observed for the first time that these domain structure changes also depend on Cu overlayer thickness.

The magnetic domain patterns of epitaxial single-crystalline Co/FeMn bilayers and Co/Cu/FeMn trilayers were investigated by magnetic circular dichroism domain imaging using photoelectron emission microscopy. The as-grown domain size increases continuously with increasing Cu layer thickness, which is attributed to the decrease of the interlayer exchange coupling between ferromagnetic Co and antiferromagnetic FeMn layers. Domain images of the Co layer acquired after applying different external magnetic fields show a decrease in coercivity with increasing Cu layer thickness, confirming the reduction of magnetic coupling energy with increasing Cu thickness.

X-ray photoemission electron microscopy (X-PEEM) is a powerful imaging technique that can be used to perform element selective magnetic domain imaging on heterogeneous samples with different magnetic layers, like spin valves and tunnel junctions. We have performed nanosecond time-resolved X-PEEM measurements, on the permalloy layer of a Ni80Fe20 (5 nm)/Cu (10 nm)/Co (5 nm) trilayer deposited on Si(111). We used the pump-probe mode, synchronizing a magnetic pulse from a microcoil with the x-ray photon bunches delivered by the BESSY synchrotron in single bunch mode. Images could be acquired during and after the 20 ns long and 80 Oe high field pulses. The nucleation and subsequent growth of reversed domains in the permalloy could be observed, demonstrating the feasibility of element selective and time-resolved domain imaging using X-PEEM.

The magnetism-induced symmetry breaking in photoelectron diffraction patterns of $2{p}_{3∕2}$ photoelectrons from a ferromagnetic Fe(001) single crystal surface is studied experimentally and theoretically. Two-dimensional photoelectron intensity angular distribution patterns were recorded at 1193 eV photon energy for both helicities of the circularly polarized light and for opposite magnetization directions of the sample by a display-type spherical mirror analyzer, which allows simultaneous energy and momentum analysis of emitted photoelectrons. The macroscopic magnetization of the sample induces an additional symmetry breaking in the circular dichroism of the $\mathrm{Fe}\phantom{\rule{0.3em}{0ex}}2{p}_{3∕2}$ photoelectron angular distribution patterns which is related to the presence of magnetic moments on the Fe atoms. Multiple-scattering cluster photoelectron diffraction calculations agree well with experiment, and reproduce even fine details of the observed photoelectron diffraction features. The details of that breaking of mirror symmetry of photoelectron scattering in the plane spanned by light incidence and electron emission due to the presence of a magnetization within that plane depends both on the structure and the magnetism of the sample. In connection with multiple scattering calculations, measurements of the magnetism-induced symmetry breaking by two-dimensional photoelectron diffraction patterns may thus be used as a powerful tool for simultaneous structural and magnetic investigations of single crystalline magnetic samples and ultrathin films.

We present experimental evidence for a three-dimensional noncollinear antiferromagnetic spin structure in ultrathin single-crystalline fcc Fe 5 0 Mn 5 0 layers using magnetic circular dichroism photoelectron emission microscopy and x-ray magnetic linear dichroism. Layer-resolved as-grown domain images of epitaxial trilayers grown on Cu(001) in which FeMn is sandwiched between ferromagnetic layers with different easy axes reveal the presence of antiferromagnetic spin components in the film plane and normal to the film plane. An FeMn spin structure with no collinear order in the film plane is consistent with the absence of x-ray magnetic linear dichroism in Fe L 3 absorption in FeMn/Co bilayers.

Using photoemission electron microscopy in combination with x-ray magnetic circular dichroism, element selective magnetic domain images have been obtained from single-crystalline Co/FeMn and FeMn/Co bilayers epitaxially grown on a Cu(001) single crystal. The contact with ferromagnetic Co leads to the observation of a net magnetic moment in Fe and Mn, independently of the paramagnetic or antiferromagnetic state of the FeMn thin films. Only a small fraction of this moment might mediate the magnetic interaction at the interface, and thus be responsible for the exchange bias effect.

Magnetic contrast for the operation of a photoelectron emission microscope (PEEM) with synchrotron radiation is provided by magnetic dichroisms. Besides the most frequently employed magnetic dichroism, magnetic circular dichroism in x-ray absorption spectroscopy, energy filtering of photoemitted electrons allows one to also use magnetic dichroisms in photoelectron emission as complementary contrast mechanisms. We demonstrate that it is possible to obtain magnetic contrast in photoemission using PEEM equipped with a simple retarding field electron energy analyzer. Magnetic domain images of an ultrathin film of 10 atomic monolayers of Fe on W(001), obtained by three, different contrast mechanisms (circular magnetic dichroism in x-ray absorption, circular magnetic dichroism in Fe valence band photoemission, and linear magnetic dichroism in Fe 3p photoemission) are presented and compared.