TY  - JOUR
A1  - König, Markus
A1  - Baenninger, Matthias
A1  - Garcia, Andrei G. F.
A1  - Harjee, Nahid
A1  - Pruitt, Beth L.
A1  - Ames, C.
A1  - Leubner, Philipp
A1  - Brüne, Christoph
A1  - Buhmann, Hartmut
A1  - Molenkamp, Laurens W.
A1  - Goldhaber-Gordon, David
T1  - Spatially Resolved Study of Backscattering in the Quantum Spin Hall State
JF  - Physical Review X
N2  - The discovery of the quantum spin Hall (QSH) state, and topological insulators in general, has sparked strong experimental efforts. Transport studies of the quantum spin Hall state have confirmed the presence of edge states, showed ballistic edge transport in micron-sized samples, and demonstrated the spin polarization of the helical edge states. While these experiments have confirmed the broad theoretical model, the properties of the QSH edge states have not yet been investigated on a local scale. Using scanning gate microscopy to perturb the QSH edge states on a submicron scale, we identify well-localized scattering sites which likely limit the expected nondissipative transport in the helical edge channels. In the micron-sized regions between the scattering sites, the edge states appear to propagate unperturbed, as expected for an ideal QSH system, and are found to be robust against weak induced potential fluctuations.
KW  - mesoscopics
KW  - topological insulators
KW  - transport
KW  - charge
KW  - wells
KW  - branched flow
KW  - nanostructures
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127225
SN  - 2160-3308
VL  - 3
IS  - 2
ER  - 
TY  - JOUR
A1  - Edgecock, T. R.
A1  - Caretta, O.
A1  - Davenne, T.
A1  - Densam, C.
A1  - Fitton, M.
A1  - Kelliher, D.
A1  - Loveridge, P.
A1  - Machida, S.
A1  - Prior, C.
A1  - Rogers, C.
A1  - Rooney, M.
A1  - Thomason, J.
A1  - Wilcox, D.
A1  - Wildner, E.
A1  - Efthymiopoulos, I.
A1  - Garoby, R.
A1  - Gilardoni, S.
A1  - Hansen, C.
A1  - Benedetto, E.
A1  - Jensen, E.
A1  - Kosmicki, A.
A1  - Martini, M.
A1  - Osborne, J.
A1  - Prior, G.
A1  - Stora, T.
A1  - Melo Mendonca, T.
A1  - Vlachoudis, V.
A1  - Waaijer, C.
A1  - Cupial, P.
A1  - Chancé, A.
A1  - Longhin, A.
A1  - Payet, J.
A1  - Zito, M.
A1  - Baussan, E.
A1  - Bobeth, C.
A1  - Bouquerel, E.
A1  - Dracos, M.
A1  - Gaudiot, G.
A1  - Lepers, B.
A1  - Osswald, F.
A1  - Poussot, P.
A1  - Vassilopoulos, N.
A1  - Wurtz, J.
A1  - Zeter, V.
A1  - Bielski, J.
A1  - Kozien, M.
A1  - Lacny, L.
A1  - Skoczen, B.
A1  - Szybinski, B.
A1  - Ustrycka, A.
A1  - Wroblewski, A.
A1  - Marie-Jeanne, M.
A1  - Balint, P.
A1  - Fourel, C.
A1  - Giraud, J.
A1  - Jacob, J.
A1  - Lamy, T.
A1  - Latrasse, L.
A1  - Sortais, P.
A1  - Thuillier, T.
A1  - Mitrofanov, S.
A1  - Loiselet, M.
A1  - Keutgen, Th.
A1  - Delbar, Th.
A1  - Debray, F.
A1  - Trophine, C.
A1  - Veys, S.
A1  - Daversin, C.
A1  - Zorin, V.
A1  - Izotov, I.
A1  - Skalyga, V.
A1  - Burt, G.
A1  - Dexter, A. C.
A1  - Kravchuk, V. L.
A1  - Marchi, T.
A1  - Cinausero, M.
A1  - Gramegna, F.
A1  - De Angelis, G.
A1  - Prete, G.
A1  - Collazuol, G.
A1  - Laveder, M.
A1  - Mazzocco, M.
A1  - Mezzetto, M.
A1  - Signorini, C.
A1  - Vardaci, E.
A1  - Di Nitto, A.
A1  - Brondi, A.
A1  - La Rana, G.
A1  - Migliozzi, P.
A1  - Moro, R.
A1  - Palladino, V.
A1  - Gelli, N.
A1  - Berkovits, D.
A1  - Hass, M.
A1  - Hirsh, T. Y.
A1  - Schuhmann, M.
A1  - Stahl, A.
A1  - Wehner, J.
A1  - Bross, A.
A1  - Kopp, J.
A1  - Neuffer, D.
A1  - Wands, R.
A1  - Bayes, R.
A1  - Laing, A.
A1  - Soler, P.
A1  - Agarwalla, S. K.
A1  - Cervera Villanueva, A.
A1  - Donini, A.
A1  - Ghosh, T.
A1  - Gómez Cadenas, J. J.
A1  - Hernández, P.
A1  - Martín-Albo, J.
A1  - Mena, O.
A1  - Burguet-Castell, J.
A1  - Agostino, L.
A1  - Buizza-Avanzini, M.
A1  - Marafini, M.
A1  - Patzak, T.
A1  - Tonazzo, A.
A1  - Duchesneau, D.
A1  - Mosca, L.
A1  - Bogomilov, M.
A1  - Karadzhov, Y.
A1  - Matev, R.
A1  - Tsenov, R.
A1  - Akhmedov, E.
A1  - Blennow, M.
A1  - Lindner, M.
A1  - Schwetz, T.
A1  - Fernández Martinez, E.
A1  - Maltoni, M.
A1  - Menéndez, J.
A1  - Giunti, C.
A1  - González García, M. C.
A1  - Salvado, J.
A1  - Coloma, P.
A1  - Huber, P.
A1  - Li, T.
A1  - López Pavón, J.
A1  - Orme, C.
A1  - Pascoli, S.
A1  - Meloni, D.
A1  - Tang, J.
A1  - Winter, W.
A1  - Ohlsson, T.
A1  - Zhang, H.
A1  - Scotto-Lavina, L.
A1  - Terranova, F.
A1  - Bonesini, M.
A1  - Tortora, L.
A1  - Alekou, A.
A1  - Aslaninejad, M.
A1  - Bontoiu, C.
A1  - Kurup, A.
A1  - Jenner, L. J.
A1  - Long, K.
A1  - Pasternak, J.
A1  - Pozimski, J.
A1  - Back, J. J.
A1  - Harrison, P.
A1  - Beard, K.
A1  - Bogacz, A.
A1  - Berg, J. S.
A1  - Stratakis, D.
A1  - Witte, H.
A1  - Snopok, P.
A1  - Bliss, N.
A1  - Cordwell, M.
A1  - Moss, A.
A1  - Pattalwar, S.
A1  - Apollonio, M.
T1  - High intensity neutrino oscillation facilities in Europe
JF  - Physical Review Special Topics-Accelerators and Beams
N2  - The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Frejus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of mu(+) and mu(-) beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular He-6 and Ne-18, also stored in a ring. The far detector is also the MEMPHYS detector in the Frejus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive.
KW  - EMMA
KW  - beta-beam
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126611
VL  - 16
IS  - 2
ER  - 
TY  - JOUR
A1  - Hedrich, Christian M.
A1  - Hofmann, Sigrun R.
A1  - Pablik, Jessica
A1  - Morbach, Henner
A1  - Girschick, Hermann J.
T1  - Autoinflammatory bone disorders with special focus on chronic recurrent multifocal osteomyelitis (CRMO)
JF  - Pediatric Rheumatology
N2  - Sterile bone inflammation is the hallmark of autoinflammatory bone disorders, including chronic nonbacterial osteomyelitis (CNO) with its most severe form chronic recurrent multifocal osteomyelitis (CRMO). Autoinflammatory osteopathies are the result of a dysregulated innate immune system, resulting in immune cell infiltration of the bone and subsequent osteoclast differentiation and activation. Interestingly, autoinflammatory bone disorders are associated with inflammation of the skin and/or the intestine. In several monogenic autoinflammatory bone disorders mutations in disease-causing genes have been reported. However, regardless of recent developments, the molecular pathogenesis of CNO/CRMO remains unclear. Here, we discuss the clinical presentation and molecular pathophysiology of human autoinflammatory osteopathies and animal models with special focus on CNO/CRMO. Treatment options in monogenic autoinflammatory bone disorders and CRMO will be illustrated.
KW  - bisphosphonate treatment
KW  - IL-10 expression
KW  - TNF-α
KW  - IL-10
KW  - inflammation
KW  - bone
KW  - CRMO
KW  - CNO
KW  - DIRA
KW  - PAPA
KW  - Majeed-Syndrome
KW  - disease
KW  - deficiency
KW  - pediatric patients
KW  - treatment
KW  - TLR4
KW  - PAPA syndrome
KW  - hypertrophic osteodystrophy
KW  - chronic nonbacterial osteomyelitis
KW  - congenital dyserythropoietic anemia
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125694
SN  - 1546-0096
VL  - 11
IS  - 47
ER  - 
TY  - JOUR
A1  - Walter, Maggie C.
A1  - Reilich, Peter
A1  - Thiele, Simone
A1  - Schessl, Joachim
A1  - Schreiber, Herbert
A1  - Reiners, Karlheinz
A1  - Kress, Wolfram
A1  - Müller-Reible, Clemens
A1  - Vorgerd, Matthias
A1  - Urban, Peter
A1  - Schrank, Bertold
A1  - Deschauer, Marcus
A1  - Schlotter-Weigel, Beate
A1  - Kohnen, Ralf
A1  - Lochmüller, Hans
T1  - Treatment of dysferlinopathy with deflazacort: a double-blind, placebo-controlled clinical trial
JF  - Orphanet Journal of Rare Diseases
N2  - Background: Dysferlinopathies are autosomal recessive disorders caused by mutations in the dysferlin (DYSF) gene encoding the dysferlin protein. DYSF mutations lead to a wide range of muscular phenotypes, with the most prominent being Miyoshi myopathy (MM) and limb girdle muscular dystrophy type 2B (LGMD2B). 
Methods: We assessed the one-year-natural course of dysferlinopathy, and the safety and efficacy of deflazacort treatment in a double-blind, placebo-controlled cross-over trial. After one year of natural course without intervention, 25 patients with genetically defined dysferlinopathy were randomized to receive deflazacort and placebo for six months each (1 mg/kg/day in month one, 1 mg/kg every 2nd day during months two to six) in one of two treatment sequences. Results: During one year of natural course, muscle strength declined about 2% as measured by CIDD (Clinical Investigation of Duchenne Dystrophy) score, and 76 Newton as measured by hand-held dynamometry. Deflazacort did not improve muscle strength. In contrast, there is a trend of worsening muscle strength under deflazacort treatment, which recovers after discontinuation of the study drug. During deflazacort treatment, patients showed a broad spectrum of steroid side effects. 
Conclusion: Deflazacort is not an effective therapy for dysferlinopathies, and off-label use is not warranted. This is an important finding, since steroid treatment should not be administered in patients with dysferlinopathy, who may be often misdiagnosed as polymyositis.
KW  - Deflazacort
KW  - muscle strength
KW  - gridle muscular-dystrophy
KW  - Duchenne dystrphy
KW  - Miyoshi myopathy
KW  - mutation
KW  - prednisone
KW  - gene
KW  - 2B
KW  - children
KW  - design
KW  - steroids
KW  - therapy
KW  - dysferlinopathy
KW  - Limb girdle muscular dystrophy (LGMD)
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125663
SN  - 1750-1172
VL  - 8
IS  - 26
ER  - 
TY  - JOUR
A1  - Weidemann, Frank
A1  - Sanchez-Nino, Maria D.
A1  - Politei, Juan
A1  - Oliveira, João-Paulo
A1  - Wanner, Christoph
A1  - Warnock, David G.
A1  - Oritz, Alberto
T1  - Fibrosis: a key feature of Fabry disease with potential therapeutic implications
JF  - Orphanet Journal of Rare Diseases
N2  - Fabry disease is a rare X-linked hereditary disease caused by mutations in the AGAL gene encoding the lysosomal enzyme alpha-galactosidase A. Enzyme replacement therapy (ERT) is the current cornerstone of Fabry disease management. Involvement of kidney, heart and the central nervous system shortens life span, and fibrosis of these organs is a hallmark of the disease. Fibrosis was initially thought to result from tissue ischemia secondary to endothelial accumulation of glycosphingolipids in the microvasculature. However, despite ready clearance of endothelial deposits, ERT is less effective in patients who have already developed fibrosis. Several potential explanations of this clinical observation may impact on the future management of Fabry disease. Alternative molecular pathways linking glycosphingolipids and fibrosis may be operative; tissue injury may recruit secondary molecular mediators of fibrosis that are unresponsive to ERT, or fibrosis may represent irreversible tissue injury that limits the therapeutic response to ERT. We provide an overview of Fabry disease, with a focus on the assessment of fibrosis, the clinical consequences of fibrosis, and recent advances in understanding the cellular and molecular mechanisms of fibrosis that may suggest novel therapeutic approaches to Fabry disease.
KW  - Fabry
KW  - fibrosis
KW  - podocyte
KW  - Lyso-Gb3
KW  - kidney
KW  - enzyme replacement therapy
KW  - alpha-galactosidase-A
KW  - focal semental glomerulosclerosis
KW  - cardiovascular magnetic-resonance
KW  - left-ventricular hypertrophy
KW  - biopsy findings
KW  - agalsidase-beta
KW  - natural-history data
KW  - cardiac energy metabolism
KW  - randomized controlled trial
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124773
SN  - 1750-1172
VL  - 8
IS  - 116
ER  - 
TY  - JOUR
A1  - Karle, Kathrin N.
A1  - Schüle, Rebecca
A1  - Klebe, Stephan
A1  - Otto, Susanne
A1  - Frischholz, Christian
A1  - Liepelt-Scarfone, Inga
A1  - Schöls, Ludger
T1  - Electrophysiological characterisation of motor and sensory tracts in patients with hereditary spastic paraplegia (HSP)
JF  - Orphanet Journal of Rare Diseases
N2  - Background: Hereditary spastic paraplegias (HSPs) are characterised by lower limb spasticity due to degeneration of the corticospinal tract. We set out for an electrophysiological characterisation of motor and sensory tracts in patients with HSP. 
Methods: We clinically and electrophysiologically examined a cohort of 128 patients with genetically confirmed or clinically probable HSP. Motor evoked potentials (MEPs) to arms and legs, somato-sensory evoked potentials of median and tibial nerves, and nerve conduction studies of tibial, ulnar, sural, and radial nerves were assessed. 
Results: Whereas all patients showed clinical signs of spastic paraparesis, MEPs were normal in 27% of patients and revealed a broad spectrum with axonal or demyelinating features in the others. This heterogeneity can at least in part be explained by different underlying genotypes, hinting for distinct pathomechanisms in HSP subtypes. In the largest subgroup, SPG4, an axonal type of damage was evident. Comprehensive electrophysiological testing disclosed a more widespread affection of long fibre tracts involving peripheral nerves and the sensory system in 40%, respectively. Electrophysiological abnormalities correlated with the severity of clinical symptoms. 
Conclusions: Whereas HSP is primarily considered as an upper motoneuron disorder, our data suggest a more widespread affection of motor and sensory tracts in the central and peripheral nervous system as a common finding in HSP. The distribution patterns of electrophysiological abnormalities were associated with distinct HSP genotypes and could reflect different underlying pathomechanisms. Electrophysiological measures are independent of symptomatic treatment and may therefore serve as a reliable biomarker in upcoming HSP trials.
KW  - motor evoked potential (MEP)
KW  - amyotrophic-lateral-sclerosis
KW  - somatosensory-evoked-potentials
KW  - Silver-syndrome
KW  - gene mutations
KW  - SPG4
KW  - mouse model
KW  - ALSIN gene
KW  - neuropathy
KW  - paraparesis
KW  - protein
KW  - electrophysiology
KW  - hereditary spastic paraplegia (HSP)
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124763
SN  - 1750-1172
VL  - 8
IS  - 158
ER  - 
TY  - JOUR
A1  - Farag, Heba Gamal
A1  - Froehler, Sebastian
A1  - Oexle, Konrad
A1  - Ravindran, Ethiraj
A1  - Schindler, Detlev
A1  - Staab, Timo
A1  - Huebner, Angela
A1  - Kraemer, Nadine
A1  - Chen, Wei
A1  - Kaindl, Angela M.
T1  - Abnormal centrosome and spindle morphology in a patient with autosomal recessive primary microcephaly type 2 due to compound heterozygous WDR62 gene mutation
JF  - Orphanet Journal of Rare Diseases
N2  - Background: Autosomal recessive primary microcephaly (MCPH) is a rare neurodevelopmental disease with severe microcephaly at birth due to a pronounced reduction in brain volume and intellectual disability. Biallelic mutations in the WD repeat-containing protein 62 gene WDR62 are the genetic cause of MCPH2. However, the exact underlying pathomechanism of MCPH2 remains to be clarified. 
Methods/results: We characterized the clinical, radiological, and cellular features that add to the human MCPH2 phenotype. Exome sequencing followed by Sanger sequencing in a German family with two affected daughters with primary microcephaly revealed in the index patient the compound heterozygous mutations c. 1313G>A (p.R438H) / c.2864-2867delACAG (p.D955Afs*112) of WDR62, the second of which is novel. Radiological examination displayed small frontal lobes, corpus callosum hypoplasia, simplified hippocampal gyration, and cerebellar hypoplasia. We investigated the cellular phenotype in patient-derived lymphoblastoid cells and compared it with that of healthy female controls. WDR62 expression in the patient's immortalized lymphocytes was deranged, and mitotic spindle defects as well as abnormal centrosomal protein localization were apparent. 
Conclusion: We propose that a disruption of centrosome integrity and/or spindle organization may play an important role in the development of microcephaly in MCPH2.
KW  - cell division
KW  - intellectual disability
KW  - missense mutations
KW  - protein
KW  - malformations
KW  - establishment
KW  - cytokinesis
KW  - genome
KW  - midbody
KW  - database
KW  - maintenance
KW  - families
KW  - microcephaly
KW  - WDR62 mutation
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123505
SN  - 1750-1172
VL  - 8
IS  - 178
ER  - 
TY  - JOUR
A1  - Mueller, Kerstin
A1  - Quandt, Jasmin
A1  - Marienfeld, Ralf B.
A1  - Weihrich, Petra
A1  - Fiedler, Katja
A1  - Claussnitzer, Melina
A1  - Laumen, Helmut
A1  - Vaeth, Martin
A1  - Berberich-Siebelt, Frederike
A1  - Serfling, Edgar
A1  - Wirth, Thomas
A1  - Brunner, Cornelia
T1  - Octamer-dependent transcription in T cells is mediated by NFAT and \(NF-\kappa B\)
JF  - Nucleic Acids Research
N2  - The transcriptional co-activator BOB.1/OBF.1 was originally identified in B cells and is constitutively expressed throughout B cell development. BOB.1/OBF.1 associates with the transcription factors Oct1 and Oct2, thereby enhancing octamer-dependent transcription. In contrast, in T cells, BOB.1/OBF.1 expression is inducible by treatment of cells with PMA/Ionomycin or by antigen receptor engagement, indicating a marked difference in the regulation of BOB.1/OBF.1 expression in B versus T cells. The molecular mechanisms underlying the differential expression of BOB.1/OBF.1 in T and B cells remain largely unknown. Therefore, the present study focuses on mechanisms controlling the transcriptional regulation of BOB.1/OBF.1 and Oct2 in T cells. We show that both calcineurin- and \(NF-\kappa B\)-inhibitors efficiently attenuate the expression of BOB.1/OBF.1 and Oct2 in T cells. In silico analyses of the BOB.1/OBF.1 promoter revealed the presence of previously unappreciated combined NFAT/\(NF-\kappa B\) sites. An array of genetic and biochemical analyses illustrates the involvement of the \(Ca^{2+}\)/calmodulin-dependent phosphatase calcineurin as well as NFAT and \(NF-\kappa B\) transcription factors in the transcriptional regulation of octamer-dependent transcription in T cells. Conclusively, impaired expression of BOB.1/OBF.1 and Oct2 and therefore a hampered octamer-dependent transcription may participate in T cell-mediated immunodeficiency caused by the deletion of NFAT or \(NF-\kappa B\) transcription factors.
KW  - germinal center formation
KW  - OBF-1 OCA-B
KW  - coactivator OBF-1
KW  - gene expression
KW  - functional characterization
KW  - immunoglobulin promoters
KW  - OCT-1-deficient mice
KW  - embryonic lethality
KW  - endothelial cells
KW  - murine homolog
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123280
SN  - 1362-4962
VL  - 41
IS  - 4
ER  - 
TY  - JOUR
A1  - Müller, Sara
A1  - Windhof, Indra M.
A1  - Maximov, Vladimir
A1  - Jurkowski, Tomasz
A1  - Jeltsch, Albert
A1  - Förstner, Konrad U.
A1  - Sharma, Cynthia M.
A1  - Gräf, Ralph
A1  - Nellen, Wolfgang
T1  - Target recognition, RNA methylation activity and transcriptional regulation of the Dictyostelium discoideum Dnmt2-homologue (DnmA)
JF  - Nucleic Acids Research
N2  - Although the DNA methyltransferase 2 family is highly conserved during evolution and recent reports suggested a dual specificity with stronger activity on transfer RNA (tRNA) than DNA substrates, the biological function is still obscure. We show that the Dictyostelium discoideum Dnmt2-homologue DnmA is an active tRNA methyltransferase that modifies C38 in \(tRNA^{Asp(GUC)}\) in vitro and in vivo. By an ultraviolet-crosslinking and immunoprecipitation approach, we identified further DnmA targets. This revealed specific tRNA fragments bound by the enzyme and identified \(tRNA^{Glu(CUC/UUC)}\) and \(tRNA^{Gly(GCC)}\) as new but weaker substrates for both human Dnmt2 and DnmA in vitro but apparently not in vivo. Dnmt2 enzymes form transient covalent complexes with their substrates. The dynamics of complex formation and complex resolution reflect methylation efficiency in vitro. Quantitative PCR analyses revealed alterations in dnmA expression during development, cell cycle and in response to temperature stress. However, dnmA expression only partially correlated with tRNA methylation in vivo. Strikingly, dnmA expression in the laboratory strain AX2 was significantly lower than in the NC4 parent strain. As expression levels and binding of DnmA to a target in vivo are apparently not necessarily accompanied by methylation, we propose an additional biological function of DnmA apart from methylation.
KW  - DNA methylferase homolog
KW  - drospophila
KW  - TRNA(ASP)
KW  - mechanism
KW  - binding
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123149
SN  - 1362-4962
VL  - 41
IS  - 18
ER  - 
TY  - JOUR
A1  - Hopfmann, C.
A1  - Albert, F.
A1  - Schneider, C.
A1  - Höfling, S.
A1  - Kamp, M.
A1  - Forchel, A.
A1  - Kanter, I.
A1  - Reizenstein, S.
T1  - Nonlinear emission characteristics of quantum dot-micropillar lasers in the presence of polarized optical feedback
JF  - New Journal of Physics
N2  - We report on electrically pumped quantum dot-microlasers in the presence of polarized self-feedback. The high-\(\beta\) microlasers show two orthogonal, linearly polarized emission modes which are coupled via the common gain medium. This coupling is explained in terms of gain competition between the two lasing modes and leads to distinct differences in their input-output characteristics. By applying polarized self-feedback via an external mirror, we are able to control the laser characteristics of the emission modes in terms of the output power, the coherence time and the photon statistics. We find that linearly polarized self-feedback stabilizes the lasing of a given mode, while cross-polarized feedback between the two modes reduces strongly the intensity of the other emission mode showing particular high-intensity fluctuations and even super-thermal values of the photon autocorrelation function \(g^{(2)} (\tau)\) at zero delay. Measurements of \(g^{(2)} (\tau)\) under external feedback also allow us to detect revival peaks associated with the round trip time of the external cavity. Analyzing the damping and shape of the \(g^{(2)} (\tau)\) revival peaks by a phenomenological model provides us insight into the underlying physics such as the effective exciton lifetime and gain characteristics of the quantum dots in the active region of these microlasers.
KW  - semiconductor lasers
KW  - coherence
KW  - system
KW  - gain
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123127
SN  - 1367-2630
VL  - 15
IS  - 025030
ER  - 
TY  - JOUR
A1  - Kim, N. Y.
A1  - Kusudo, K.
A1  - Löffler, A.
A1  - Höfling, S.
A1  - Forchel, A.
A1  - Yamamoto, Y.
T1  - Exciton-polariton condensates near the Dirac point in a triangular lattice
JF  - New Journal of Physics
N2  - Dirac particles, massless relativistic entities, obey linear energy dispersions and hold important implications in particle physics. The recent discovery of Dirac fermions in condensed matter systems including graphene and topological insulators has generated a great deal of interest in exploring the relativistic properties associated with Dirac physics in solid-state materials. In addition, there are stimulating research activities to engineer Dirac particles, elucidating their exotic physical properties in a controllable setting. One of the successful platforms is the ultracold atom-optical lattice system, whose dynamics can be manipulated and probed in a clean environment. A microcavity exciton-polariton-lattice system offers the advantage of forming high-orbital condensation in non-equilibrium conditions, which enables one to explore novel quantum orbital order in two dimensions. In this paper, we experimentally construct the band structures near Dirac points, the vertices of the first hexagonal Brillouin zone with exciton-polariton condensates trapped in a triangular lattice. Due to the finite spectral linewidth, the direct map of band structures at Dirac points is elusive; however, we identify the linear part above Dirac points and its associated velocity value is similar to ~0.9-2 x \(10^8 cm s^{-1}\), consistent with the theoretical estimate \(1 x 10^8 cm s^{-1}\) with a \(2 \mu m\) lattice constant. We envision that the exciton-polariton condensates in lattices would be a promising solid-state platform, where the system order parameter can be accessed in both real and momentum spaces.
KW  - Bose-Einstein condensation
KW  - carbon nanotubes
KW  - graphene
KW  - electron
KW  - dynamics
KW  - fermions
KW  - trap
KW  - gas
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123103
SN  - 1367-2630
VL  - 15
IS  - 035032
ER  - 
TY  - JOUR
A1  - Kasprzak, J.
A1  - Sivalertporn, K.
A1  - Albert, F.
A1  - Schneider, C.
A1  - Höfling, S.
A1  - Kamp, M.
A1  - Forchel, A.
A1  - Muljarov, E. A.
A1  - Langbein, W.
T1  - Coherence dynamics and quantum-to-classical crossover in an exciton-cavity system in the quantum strong coupling regime
JF  - New Journal of Physics
N2  - Interaction between light and matter generates optical nonlinearities, which are particularly pronounced in the quantum strong coupling regime. When a single bosonic mode couples to a single fermionic mode, a Jaynes-Cummings (JC) ladder is formed, which we realize here using cavity photons and quantum dot excitons. We measure and model the coherent anharmonic response of this strongly coupled exciton-cavity system at resonance. Injecting two photons into the cavity, we demonstrate a \(\sqrt 2\) larger polariton splitting with respect to the vacuum Rabi splitting. This is achieved using coherent nonlinear spectroscopy, specifically four-wave mixing, where the coherence between the ground state and the first (second) rung of the JC ladder can be interrogated for positive (negative) delays. With increasing excitation intensity and thus rising average number of injected photons, we observe spectral signatures of the quantum-to-classical crossover of the strong coupling regime.
KW  - Jaynes-Cummings ladder
KW  - spectral interferometry
KW  - photon
KW  - dot
KW  - spectroscopy
KW  - oscillations
KW  - microcavity
KW  - resonance
KW  - light
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123005
SN  - 1367-2630
VL  - 15
IS  - 045013
ER  - 
TY  - JOUR
A1  - Okada, Michio
A1  - Rotenberg, Eli
A1  - Kevan, S. D.
A1  - Schäfer, J.
A1  - Ujfalussy, Balazs
A1  - Stocks, G. Malcolm
A1  - Genatempo, B.
A1  - Bruno, E.
A1  - Plummer, E. W.
T1  - Evolution of the electronic structure in \(Mo_{1-x}Re_x\) alloys
JF  - New Journal of Physics
N2  - We report a detailed experimental and theoretical study of the electronic structure of \(Mo_{1-x}Re_x\) random alloys. We have measured electronic band dispersions for clean and hydrogen-covered \(Mo_{1-x}Re_x\) ( 110) with x = 0-0.25 using angle-resolved photoemission spectroscopy. Our results suggest that the bulk and most surface electronic bands shift relative to the Fermi level systematically and approximately rigidly with Re concentration. We distinguish and quantify two contributions to these shifts: a raise of the Fermi energy and an increase of the overall bandwidth. Alloy bands calculated using the first-principles Korringa-Kohn-Rostoker coherent-potential-approximation method accurately predict both of these effects. As derived from the rigid band model, the Fermi energy shift is inversely related to the bulk density of states in this energy region. Using our results, we also characterize an electronic topological transition of the bulk Fermi surface and relate this to bulk transport properties. Finally, we distinguish effects beyond the rigid band approximation: a highly surface-localized state and a composition-dependent impact of the spin-orbit interaction.
KW  - topological transitions
KW  - surface state
KW  - metals
KW  - total energy
KW  - W(110)
KW  - hydrogen
KW  - mo
KW  - superconductivity
KW  - spectra
KW  - coherent potential approximation
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122993
SN  - 1367-2630
VL  - 15
IS  - 093010
ER  - 
TY  - JOUR
A1  - Zadeh-Khorasani, Maryam
A1  - Nolte, Thomas
A1  - Mueller, Thomas D.
A1  - Pechlivanis, Markos
A1  - Rueff, Franziska
A1  - Wollenberg, Andreas
A1  - Fricker, Gert
A1  - Wolf, Eckhard
A1  - Siebeck, Matthias
A1  - Gropp, Roswitha
T1  - NOD-scid IL2R \(\gamma^{null}\) mice engrafted with human peripheral blood mononuclear cells as a model to test therapeutics targeting human signaling pathways
JF  - Journal of Translational Medicine
N2  - Background: Animal models of human inflammatory diseases have limited predictive quality for human clinical trials for various reasons including species specific activation mechanisms and the immunological background of the animals which markedly differs from the genetically heterogeneous and often aged patient population. 
Objective: Development of an animal model allowing for testing therapeutics targeting pathways involved in the development of Atopic Dermatitis (AD) with better translatability to the patient. 
Methods: NOD-scid IL2R \(\gamma^{null}\) mice engrafted with human peripheral blood mononuclear cells (hPBMC) derived from patients suffering from AD and healthy volunteers were treated with IL-4 and the antagonistic IL-4 variant R121/Y124D (Pitrakinra). Levels of human (h) IgE, amount of B-, T- and plasma-cells and ratio of CD4 : CD8 positive cells served as read out for induction and inhibition of cell proliferation and hIgE secretion. Results were compared to in vitro analysis. 
Results: hIgE secretion was induced by IL-4 and inhibited by the IL-4 antagonist Pitrakinra in vivo when formulated with methylcellulose. B-cells proliferated in response to IL-4 in vivo; the effect was abrogated by Pitrakinra. IL-4 shifted CD4 : CD8 ratios in vitro and in vivo when hPBMC derived from healthy volunteers were used. Pitrakinra reversed the effect. Human PBMC derived from patients with AD remained inert and engrafted mice reflected the individual responses observed in vitro. 
Conclusion: NOD-scid IL2R \(\gamma^{null}\) mice engrafted with human PBMC reflect the immunological history of the donors and provide a complementary tool to in vitro studies. Thus, studies in this model might provide data with better translatability from bench to bedside.
KW  - atopic dermatitis
KW  - T-cells
KW  - rheumatoid arthritis
KW  - human interleukin-4
KW  - TGN1412
KW  - oxazolone colitis
KW  - cytokine release
KW  - expression
KW  - antagonists
KW  - responses
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122960
SN  - 1479-5876
VL  - 11
IS  - 4
ER  - 
TY  - JOUR
A1  - Vainio, Rami
A1  - Valtonen, Eino
A1  - Heber, Bernd
A1  - Malandraki, Olga E.
A1  - Papaioannou, Athanasios
A1  - Klein, Karl-Ludwig
A1  - Afanasiev, Alexander
A1  - Agueda, Neus
A1  - Aurass, Henry
A1  - Battarbee, Markus
A1  - Braune, Stephan
A1  - Dröge, Wolfgang
A1  - Ganse, Urs
A1  - Hamadache, Clarisse
A1  - Heynderickx, Daniel
A1  - Huttunen-Heikinmaa, Kalle
A1  - Kiener, Jürgen
A1  - Kilian, Patrick
A1  - Kopp, Andreas
A1  - Kouloumvakos, Athanasios
A1  - Maisala, Sami
A1  - Mishev, Alexander
A1  - Miteva, Rosita
A1  - Nindos, Alexander
A1  - Oittinen, Tero
A1  - Raukunen, Osku
A1  - Riihonen, Esa
A1  - Rodriguez-Gasen, Rosa
A1  - Saloniemi, Oskari
A1  - Sanahuja, Blai
A1  - Scherer, Renate
A1  - Spanier, Felix
A1  - Tatischeff, Vincent
A1  - Tziotziou, Kostas
A1  - Usoskin, Ilya G.
A1  - Vilmer, Nicole
T1  - The first SEPServer event catalogue similar to ~68-MeV solar proton events observed at 1 AU in 1996-2010
JF  - Journal of Space Weather and Space Climate
N2  - SEPServer is a three-year collaborative project funded by the seventh framework programme (FP7-SPACE) of the European Union. The objective of the project is to provide access to state-of-the-art observations and analysis tools for the scientific community on solar energetic particle (SEP) events and related electromagnetic (EM) emissions. The project will eventually lead to better understanding of the particle acceleration and transport processes at the Sun and in the inner heliosphere. These processes lead to SEP events that form one of the key elements of space weather. In this paper we present the first results from the systematic analysis work performed on the following datasets: SOHO/ERNE, SOHO/EPHIN, ACE/EPAM, Wind/WAVES and GOES X-rays. A catalogue of SEP events at 1 AU, with complete coverage over solar cycle 23, based on high-energy (similar to 68-MeV) protons from SOHO/ERNE and electron recordings of the events by SOHO/EPHIN and ACE/EPAM are presented. A total of 115 energetic particle events have been identified and analysed using velocity dispersion analysis (VDA) for protons and time-shifting analysis (TSA) for electrons and protons in order to infer the SEP release times at the Sun. EM observations during the times of the SEP event onset have been gathered and compared to the release time estimates of particles. Data from those events that occurred during the European day-time, i.e., those that also have observations from ground-based observatories included in SEPServer, are listed and a preliminary analysis of their associations is presented. We find that VDA results for protons can be a useful tool for the analysis of proton release times, but if the derived proton path length is out of a range of 1 AU < s less than or similar to 3 AU, the result of the analysis may be compromised, as indicated by the anti-correlation of the derived path length and release time delay from the associated X-ray flare. The average path length derived from VDA is about 1.9 times the nominal length of the spiral magnetic field line. This implies that the path length of first-arriving MeV to deka-MeV protons is affected by interplanetary scattering. TSA of near-relativistic electrons results in a release time that shows significant scatter with respect to the EM emissions but with a trend of being delayed more with increasing distance between the flare and the nominal footpoint of the Earth-connected field line.
KW  - radio emissions (dynamic)
KW  - projects
KW  - advanced composition explorer
KW  - wind spacecraft
KW  - stereo mission
KW  - alpha monitor
KW  - electron
KW  - plasma
KW  - radio
KW  - spectrometer
KW  - heliosphere
KW  - instrument
KW  - radiation
KW  - flares
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122847
SN  - 2115-7251
VL  - 3
IS  - A12
ER  - 
TY  - JOUR
A1  - Ojha, Animesh K.
A1  - Forster, Stefan
A1  - Kumar, Sumeet
A1  - Vats, Siddharth
A1  - Negi, Segeeta
A1  - Fischer, Ingo
T1  - Synthesis of well-dispersed silver nanorods of different aspect ratios and their antimicrobial properties against gram positive and negative bacterial strains
JF  - Journal of Nanobiotechnology
N2  - In the present contribution, we describe the synthesis of highly dispersed silver nanorods (NRs) of different aspect ratios using a chemical route. The shape and size of the synthesized NRs were characterized by Transmission Electron Microscopy (TEM) and UV-visible spectroscopy. Longitudinal and transverse absorptions bands confirm the rod type structure. The experimentally recorded UV-visible spectra of NRs solutions were fitted by using an expression of the extinction coefficient for rod like nano structures under the dipole approximation. Simulated and experimentally observed UV-visible spectra were compared to determine the aspect ratios (R) of NRs. The average values of R for NR1, NR2 and NR3 solutions are estimated to be 3.0 +/- 0.1, 1.8 +/- 0.1 and 1.2 +/- 0.1, respectively. These values are in good agreement with those obtained by TEM micrographs. The silver NRs of known aspect ratios are used to study antimicrobial activities against B. subtilis (gram positive) and E. coli (gram negative) microbes. We observed that the NRs of intermediate aspect ratio (R = 1.8) have greater antimicrobial effect against both, B. subtilis (gram positive) and E. coli (gram negative). The NRs of aspect ratio, R = 3.0 has better antimicrobial activities against gram positive than on the gram negative.
KW  - silver
KW  - nano rods
KW  - TEM
KW  - antimicrobial activities
KW  - nanowire formation
KW  - gold nanoparticles
KW  - Raman-scattering
KW  - nanostructures
KW  - particles
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122837
SN  - 1477-3155
VL  - 11
IS  - 42
ER  - 
TY  - JOUR
A1  - Meuche, Ivonne
A1  - Brusa, Oscar
A1  - Linsenmair, K. Eduard
A1  - Keller, Alexander
A1  - Pröhl, Heike
T1  - Only distance matters - non-choosy females in a poison frog population
JF  - Frontiers in Zoology
N2  - Background: Females have often been shown to exhibit preferences for certain male traits. However, little is known about behavioural rules females use when searching for mates in their natural habitat. We investigated mate sampling tactics and related costs in the territorial strawberry poison frog (Oophaga pumilio) possessing a lek-like mating system, where both sequential and simultaneous sampling might occur. We continuously monitored the sampling pattern and behaviour of females during the complete period between two successive matings. 
Results: We found no evidence that females compared males by visiting them. Instead females mated with the closest calling male irrespective of his acoustic and physical traits, and territory size. Playback experiments in the natural home ranges of receptive females revealed that tested females preferred the nearest speaker and did not discriminate between low and high call rates or dominant frequencies. 
Conclusions: Our results suggest that females of O. pumilio prefer the closest calling male in the studied population. We hypothesize that the sampling tactic in this population is affected by 1) a strongly female biased sex ratio and 2) a low variance in traits of available males due to strong male-male competition, preventing low quality males from defending a territory and mating.
KW  - operational sex ratio
KW  - sequential mate choice
KW  - gray tree frogs
KW  - treefrogs hyla-gratiosa
KW  - male mating success
KW  - Bocas-del-Toro
KW  - dendrobates pumilio
KW  - oophaga pumilio
KW  - pied flycatchers
KW  - sampling behavior
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122617
SN  - 1742-9994
VL  - 10
IS  - 29
ER  - 
TY  - JOUR
A1  - Menzel, Florian
A1  - Blüthgen, Nico
A1  - Tolasch, Till
A1  - Conrad, Jürgen
A1  - Beifuss, Uwe
A1  - Beuerle, Till
A1  - Schmitt, Thomas
T1  - Crematoenones - a novel substance class exhibited by ants functions as appeasement signal
JF  - Frontiers in Zoology
N2  - Background: Parasitic, commensalistic, and mutualistic guests in social insect colonies often circumvent their hosts' nestmate recognition system to be accepted. These tolerance strategies include chemical mimicry and chemical insignificance. While tolerance strategies have been studied intensively in social parasites, little is known about these mechanisms in non-parasitic interactions. Here, we describe a strategy used in a parabiotic association, i.e. two mutualistic ant species that regularly share a common nest although they have overlapping food niches. One of them, Crematogaster modiglianii, produces an array of cuticular compounds which represent a substance class undescribed in nature so far. They occur in high abundances, which suggests an important function in the ant's association with its partner Camponotus rufifemur. 
Results: We elucidated the structure of one of the main compounds from cuticular extracts using gas chromatography, mass spectrometry, chemical derivatizations and nuclear magnetic resonance spectroscopy (NMR). The compound consists of two fused six-membered rings with two alkyl groups, one of which carries a keto functionality. To our knowledge, this is the first report on the identification of this substance class in nature. We suggest naming the compound crematoenone. In behavioural assays, crematoenones reduced interspecific aggression. Camponotus showed less aggression to allospecific cuticular hydrocarbons when combined with crematoenones. Thus, they function as appeasement substances. However, although the crematoenone composition was highly colony-specific, interspecific recognition was mediated by cuticular hydrocarbons, and not by crematoenones. 
Conclusions: Crematenones enable Crematogaster to evade Camponotus aggression, and thus reduce potential costs from competition with Camponotus. Hence, they seem to be a key factor in the parabiosis, and help Crematogaster to gain a net benefit from the association and thus maintain a mutualistic association over evolutionary time. To our knowledge, putative appeasement substances have been reported only once so far, and never between non-parasitic species. Since most organisms associated with social insects need to overcome their nestmate recognition system, we hypothesize that appeasement substances might play an important role in the evolution and maintenance of other mutualistic associations as well, by allowing organisms to reduce costs from antagonistic behaviour of other species.
KW  - cuticular hydrocarbons
KW  - appeasement substance
KW  - bees
KW  - ecology
KW  - parasitism
KW  - alkyloctahydronaphthalene
KW  - usurpation
KW  - venom
KW  - pheromone
KW  - crematogaster
KW  - parabiotic ants
KW  - Dufours gland
KW  - polyergus rufescens
KW  - formicidae
KW  - interspecific aggression
KW  - nestmate recognition cues
KW  - parabiotic association
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122595
SN  - 1742-9994
VL  - 10
IS  - 32
ER  - 
TY  - JOUR
A1  - Fischer, Rico
A1  - Plessow, Franziska
A1  - Kiesel, Andrea
T1  - The effects of alerting signals in masked priming
JF  - Frontiers in Psychology
N2  - Alerting signals often serve to reduce temporal uncertainty by predicting the time of stimulus onset. The resulting response time benefits have often been explained by facilitated translation of stimulus codes into response codes on the basis of established stimulus-response (S-R) links. In paradigms of masked S-R priming alerting signals also modulate response activation processes triggered by subliminally presented prime stimuli. In the present study we tested whether facilitation of visuo-motor translation processes due to alerting signals critically depends on established S-R links. Alerting signals resulted in significantly enhanced masked priming effects for masked prime stimuli that included and that did not include established S-R links fi.e., target vs. novel primes). Yet, the alerting-priming interaction was more pronounced for target than for novel primes. These results suggest that effects of alerting signals on masked priming are especially evident when S-R links between prime and target exist. At the same time, an alerting-priming interaction also for novel primes suggests that alerting signals also facilitate stimulus-response translation processes when masked prime stimuli provide action-trigger conditions in terms of programmed S-R links.
KW  - response selection
KW  - visual cortex
KW  - temporal predictability
KW  - stimuli
KW  - primes
KW  - target primes
KW  - simon task
KW  - automaticity
KW  - performance
KW  - perception
KW  - mechanism
KW  - novel primes
KW  - action-trigger
KW  - masked priming
KW  - accessory
KW  - alerting signal
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122581
SN  - 1664-1078
VL  - 4
IS  - 448
ER  - 
TY  - JOUR
A1  - Meule, Adrian
A1  - Kübler, Andrea
A1  - Blechert, Jens
T1  - Time course of electrocortical food-cue responses during cognitive regulation of craving
JF  - Frontiers in Psychology
N2  - In our current obesogenic environment, exposure to visual food-cues can easily lead to craving and overeating because short-term, pleasurable effects of food intake dominate over the anticipated long-term adverse effects such as weight gain and associated health problems. Here we contrasted these two conditions during food-cue presentation while acquiring event-related potentials (ERPs) and subjective craving ratings. Female participants (n = 25) were presented with either high-calorie (HC) or low-calorie (LC) food images under instructions to imagine either immediate (NOW) or long-term effects (LATER) of consumption. On subjective ratings for HC foods, the LATER perspective reduced cravings as compared to the NOW perspective. For LC foods, by contrast, craving increased under the LATER perspective. Early ERPs (occipital N1, 150-200 ms) were sensitive to food type but not to perspective. Late ERPs (late positive potential, LPP, 350-550 ms) were larger in the HC-LATER condition than in all other conditions, possibly indicating that a cognitive focus on negative long-term consequences induced negative arousal. This enhancement for HC-LATER attenuated to the level of the LC conditions during the later slow wave (550-3000 ms), but amplitude in the HC-NOW condition was larger than in all other conditions, possibly due to a delayed appetitive response. Across all conditions, LPP amplitudes were positively correlated with self-reported emotional eating. In sum, results reveal that regulation effects are secondary to an early attentional analysis of food type and dynamically evolve over time. Adopting a long-term perspective on eating might promote a healthier food choice across a range of food types.
KW  - EEG
KW  - disorder examination questionnaire
KW  - eating disorder
KW  - emotion regulation
KW  - future directions
KW  - attention
KW  - brain
KW  - high-calorie
KW  - german version
KW  - bulimia nervosa
KW  - chocolate images
KW  - event-related potentials
KW  - eating
KW  - calorie content
KW  - food-cues
KW  - food craving
KW  - LPP
KW  - slow wave
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122566
SN  - 1664-1078
VL  - 4
IS  - 669
ER  -