cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Perturbation theory for quasienergy (Floquet) solutions in the low-frequency regime of the oscillating electric field
Creators: name: Martiskainen, Hanna
name: Moiseyev, Nimrod
Publisher: name: arXiv
Year: 2014
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: For a simple illustrative model Hamiltonian for Xenon in low frequency linearly polarized laser field we obtain a remarkable agreement between the zero-order energy as well as amplitude and phase of the zero-order Floquet states and the exact eigenvalues and eigenfunctions of the Floquet operator. Here we use as a zero-order Hamiltonian the adiabatic Hamiltonian where time is used as an instantaneous parameter. Moreover, for a variety of low laser frequencies, $ω$, the deviation of the zero-order solutions from the exact quasi-energy (QE) Floquet solutions approaches zero at the time the oscillating laser field is maximal. This remarkable result gives a further justification to the validity of the first step in the simple man model. It should be stressed that the numerical calculations of the exact QE (Floquet) solutions become extremely difficult when $ω$ approaches zero and many Floquet channels are nested together and are coupled by the laser field. This is the main motivation for the development of perturbation theory for QE (Floquet) solutions when the laser frequency is small, to avoid the need to represent the Floquet operator by a matrix when the Fourier functions are used as a basis set. A way to calculate the radius of convergence of the perturbational expansion of the Floquet solutions in $ω$ is given.
description: 7 pages, 6 figures
Mutual information neural estimation for unsupervised multi-modal registration of brain images
Creators: name: Snaauw, Gerard
name: Sasdelli, Michele
name: Maicas, Gabriel
name: Lau, Stephan
name: Verjans, Johan
name: Jenkinson, Mark
name: Carneiro, Gustavo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Many applications in image-guided surgery and therapy require fast and reliable non-linear, multi-modal image registration. Recently proposed unsupervised deep learning-based registration methods have demonstrated superior performance compared to iterative methods in just a fraction of the time. Most of the learning-based methods have focused on mono-modal image registration. The extension to multi-modal registration depends on the use of an appropriate similarity function, such as the mutual information (MI). We propose guiding the training of a deep learning-based registration method with MI estimation between an image-pair in an end-to-end trainable network. Our results show that a small, 2-layer network produces competitive results in both mono- and multi-modal registration, with sub-second run-times. Comparisons to both iterative and deep learning-based methods show that our MI-based method produces topologically and qualitatively superior results with an extremely low rate of non-diffeomorphic transformations. Real-time clinical application will benefit from a better visual matching of anatomical structures and less registration failures/outliers.
description: 4 pages, 4 figures, 2022 44th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), oral presentation
Class I histone deacetylases (HDAC) critically contribute to Ewing sarcoma pathogenesis
Creators: name: Schmidt, Oxana
name: Nehls, Nadja
name: Prexler, Carolin
name: Heyking, Kristina Von
name: Groll, Tanja
name: Pardon, Katharina
name: Garcia, Heathcliff D.
name: Hensel, Tim
name: Gürgen, Dennis
name: Henssen, Anton G.
name: Eggert, Angelika
name: Steiger, Katja
name: Burdach, Stefan
name: Richter, Günther H. S.
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2021
Subjects: subject: Ewing sarcoma
subject: Class I HDACs
subject: Expression profiles
subject: Pathogenesis
subject: Targeted therapy
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::610 Medizin und Gesundheit

description: Background: Histone acetylation and deacetylation seem processes involved in the pathogenesis of Ewing sarcoma (EwS). Here histone deacetylases (HDAC) class I were investigated. Methods: Their role was determined using different inhibitors including TSA, Romidepsin, Entinostat and PCI-34051 as well as CRISPR/Cas9 class I HDAC knockouts and HDAC RNAi. To analyze resulting changes microarray analysis, qRT-PCR, western blotting, Co-IP, proliferation, apoptosis, differentiation, invasion assays and xenograft-mouse models were used. Results: Class I HDACs are constitutively expressed in EwS. Patients with high levels of individual class I HDAC expression show decreased overall survival. CRISPR/Cas9 class I HDAC knockout of individual HDACs such as HDAC1 and HDAC2 inhibited invasiveness, and blocked local tumor growth in xenograft mice. Microarray analysis demonstrated that treatment with individual HDAC inhibitors (HDACi) blocked an EWS-FLI1 specific expression profile, while Entinostat in addition suppressed metastasis relevant genes. EwS cells demonstrated increased susceptibility to treatment with chemotherapeutics including Doxorubicin in the presence of HDACi. Furthermore, HDACi treatment mimicked RNAi of EZH2 in EwS. Treated cells showed diminished growth capacity, but an increased endothelial as well as neuronal differentiation ability. HDACi synergizes with EED inhibitor (EEDi) in vitro and together inhibited tumor growth in xenograft mice. Co-IP experiments identified HDAC class I family members as part of a regulatory complex together with PRC2. Conclusions: Class I HDAC proteins seem to be important mediators of the pathognomonic EWS-ETS-mediated transcription program in EwS and in combination therapy, co-treatment with HDACi is an interesting new treatment opportunity for this malignant disease.
On K3-fibred LARGE Volume Scenario with de Sitter vacua from anti-D3-branes
Creators: name: AbdusSalam, Shehu
name: Crinò, Chiara
name: Shukla, Pramod
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In the context of type IIB superstring compactifications on K3-fibred (weak) Swiss-cheese Calabi Yau (CY) orientifolds, we consider the realisation of de Sitter vacua obtained through the introduction of an anti-D3-brane at the tip of a highly warped throat of Klebanov-Strassler type. Aiming to have a concrete global realisation, we perform a systematic search for the CY threefolds with $2 < h^{1,1} < 5$ arising from the Kreuzer-Skarke database, which satisfy the minimal requirements of being K3-fibred and suitable for moduli stabilisation within the LARGE Volume Scenario (LVS). In this context, after scanning the set of K3-fibred CY threefolds with a so-called diagonal del-Pezzo divisor needed for LVS, we realise that one of the main challenging requirements for having anti-D3-brane uplifting is to find a suitable orientifold involution which can simultaneously result in a sufficient large $D3$ tadpole charge along with the presence of suitable $O3$-planes. In our detailed analysis (limited to) using the CY threefolds with small $h^{1,1}$, we observe that these topological requirements rule out most of the CY geometries leading to only few possibly suitable candidates for the purpose of anti-D3-brane uplifting. Subsequently, we present a global model using one such explicit K3-fibred CY threefold with $h^{1,1}=4$ in which all the moduli can be consistently stabilised in a de Sitter minimum of the scalar potential.
description: v2: 40 pages, 1 figure, improved version to appear in JHEP; v1: 37 pages, 1 figure
Combined hybrid functional and DFT+$U$ calculations for metal chalcogenides
Creators: name: Aras, Mehmet
name: Kılıç, Çetin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In the density-functional studies of materials with localized electronic states, the local/semilocal exchange-correlation functionals are often either combined with a Hubbard parameter $U$ as in the LDA+$U$ method or mixed with a fraction of exactly computed (Fock) exchange energy yielding a hybrid functional. Although some inaccuracies of the semilocal density approximations are thus fixed to a certain extent, the improvements are not sufficient to make the predictions agree with the experimental data. Here we put forward the perspective that the hybrid functional scheme and the LDA+$U$ method should be treated as complementary, and propose to combine the range-separated (HSE) hybrid functional with the Hubbard $U$. We thus present a variety of HSE+$U$ calculations for a set of II-VI semiconductors, consisting of zinc and cadmium monochalcogenides, along with comparison to the experimental data. Our findings imply that an optimal value $U^\ast$ of the Hubbard parameter could be determined, which ensures that the HSE+$U^\ast$ calculation reproduces the experimental band gap. It is shown that an improved description not only of the electronic structure but also of the crystal structure and energetics is obtained by adding the $U^\ast$ term to the HSE functional, proving the utility of HSE+$U^\ast$ approach in modeling semiconductors with localized electronic states.
An attempt to explain the neurological symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Creators: name: Wirth, Klaus J.
name: Scheibenbogen, Carmen
name: Paul, Friedemann
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2021
Subjects: subject: Chronic Fatigue Syndrome
subject: Myalgic Encephalomyelitis
subject: Post-Covid-19 syndrome
subject: Neurological symptoms
subject: Cognitive impairment
subject: Brain fog
subject: Hypersensitivity
subject: Dysautonomia
subject: Sleep disturbance
subject: Headache
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::610 Medizin und Gesundheit

description: There is accumulating evidence of endothelial dysfunction, muscle and cerebral hypoperfusion in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). In this paper we deduce the pathomechanisms resulting in central nervous pathology and the myriad of neurocognitive symptoms. We outline tentative mechanisms of impaired cerebral blood flow, increase in intracranial pressure and central adrenergic hyperactivity and how they can well explain the key symptoms of cognitive impairment, brain fog, headache, hypersensitivity, sleep disturbances and dysautonomia.
Gauge Natural Formulation of Conformal Theory of Gravity
Creators: name: Campigotto, M.
name: Fatibene, L.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider conformal gravity as a gauge natural theory. We study its conservation laws and superpotentials. We also consider the Mannheim and Kazanas spherically symmetric vacuum solution and discuss conserved quantities associated to conformal and diffeomorphism symmetries.
description: 13 pages, calculations added, matches published version on Annals of Physics
Eine neue Methode zur Vermeidung von Aspirationen [A new method to avoid aspirations (author's transl.)]
Creators: name: Ruben, H.
name: Hansen, Ernil
name: Ahnefeld, F. W.
name: Dick, W.
name: Wyrwoll, K.
Publisher: name: Universität Regensburg
Year: 1978
Subjects: subject: 610 Medizin
subject: Humans
subject: Inhalation
subject: Intubation, Intratracheal
subject: Respiration
subject: Suction
subject: Wounds and Injuries/complications

description: When treating accident victims and other high-risk patients there is always the danger of aspiration until intubation has been completed. An ancillary unit is described that can be connected to any type of tracheal aspirator, working on the principle of increasing the suction. Thus liquids and solid particles can always be sucked out quickly and effectively. In this way the danger of aspiration is considerably reduced or avoided altogether.
The level two Zhu algebra for the Heisenberg vertex operator algebra
Creators: name: Addabbo, Darlayne
name: Barron, Katrina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 7B68, 17B69, 17B81, 81R10, 81T40, 81T60

description: We determine the level two Zhu algebra for the Heisenberg vertex operator algebra $V$ for any choice of conformal element. We do this using only the following information for $V$: the internal structure of $V$; the level one Zhu algebra of $V$ already determined by the second author, along with Vander Werf and Yang; and the information the lower level Zhu algebras give regarding irreducible modules. We are able to carry out this calculation of the level two Zhu algebra for $V$ with this minimal information by employing the general results and techniques for determining generators and relations for higher level Zhu algebras for a vertex operator algebra, as developed previously by the authors in "On generators and relations for higher level Zhu algebras and applications", by Addabbo and Barron, J. Algebra, 2023. In particular, we show that the level $n$ Zhu algebras for the Heisenberg vertex operator algebra become noncommutative at level $n=2$. We also give a conjecture for the structure of the level $n$ Zhu algebra for the Heisenberg vertex operator algebra, for any $n >2$.
description: 65 pages; minor typos corrected; some calculations shortened
The effect of revascularization on recovery of mitochondrial respiration in peripheral artery disease: a case control study
Creators: name: Gratl, Alexandra
name: Pesta, Dominik
name: Gruber, Leonhard
name: Speichinger, Fiona
name: Raude, Ben
name: Omran, Safwan
name: Greiner, Andreas
name: Frese, Jan Paul
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2021
Subjects: subject: Mitochondrial function
subject: Mitochondrial respiration
subject: Peripheral arterial disease
subject: PAD
subject: Revascularization
subject: Intermittent claudication
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::610 Medizin und Gesundheit

description: Background: Peripheral arterial disease (PAD) is accompanied by myopathy characterized by mitochondrial dysfunction. The aim of this experimental study was to investigate the effect of revascularization procedures on mitochondrial function in ischemic and non-ischemic muscle. Methods: Muscle biopsies from patients with symptomatic stage IIB/III PAD caused by isolated pathologies of the superficial femoral artery were obtained from muscle regions within the chronic ischemic muscle (gastrocnemius) and from non-ischemic muscle (vastus lateralis) before and 6 weeks after invasive revascularization. High-resolution respirometry was used to investigate mitochondrial function and results were normalized to citrate synthase activity (CSA). Results are given in absolute values and fold over basal (FOB). Results: Respiratory states (OXPHOS (P) and electron transfer (E) capacity) normalized to CSA decreased while CSA was increased in chronic ischemic muscle after revascularization. There were no changes in in non-ischemic muscle. The FOB of chronic ischemic muscle was significantly higher for CSA (chronic ischemic 1.37 (IQR 1.10-1.64) vs. non-ischemic 0.93 (IQR 0.69-1.16) p=0.020) and significantly lower for respiratory states normalized to CSA when compared to the non-ischemic muscle (P per CSA chronic ischemic 0.64 (IQR 0.46-0.82) vs non-ischemic 1.16 (IQR 0.77-1.54) p=0.011; E per CSA chronic ischemic 0.61 (IQR 0.47-0.76) vs. non-ischemic 1.02 (IQR 0.64-1.40) p=0.010). Conclusions: Regeneration of mitochondrial content and function following revascularization procedures only occur in muscle regions affected by malperfusion. This indicates that the restoration of blood and oxygen supply are important mediators aiding mitochondrial recovery.
Quantum Unfolding: A program for unfolding electronic energy bands of materials
Creators: name: Zheng, Fawei
name: Zhang, Ping
name: Duan, Wenhui
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present Quantum Unfolding, a Fortran90 program for unfolding first-principles electronic energy bands. It unfolds energy bands accurately by handling the Fourier components of Bloch wavefunctions, which are reconstructed from Wannier functions from Wannier90. Due to the wide application of Wannier90 package and the possibility of focusing only on the most important energy bands, the present code works very conveniently.
Quantifizierung von Histokompatibilitätsantigenen auf Rattenlymphozyten mittels Durchflusszytometrie [Quantitation of histocompatibility antigens on rat lymphocytes by flow cytometry (author's transl)]
Creators: name: Hansen, Ernil
Publisher: name: Universität Regensburg
Year: 1982
Subjects: subject: 610 Medizin
subject: Animals
subject: B-Lymphocytes/immunology
subject: Bone Marrow Cells
subject: Cell Separation
subject: Flow Cytometry
subject: Histocompatibility Antigens/analysis
subject: Lymph Nodes/cytology
subject: Lymphocytes/immunology
subject: Male
subject: Methods
subject: Rats
subject: Spleen/cytology
subject: T-Lymphocytes/immunology
subject: Thymus Gland/cytology

description: zugleich Diss. LMU München 1982. lt. DNB: Diss. A
The Davenport constant of a box
Creators: name: Plagne, Alain
name: Tringali, Salvatore
Publisher: name: arXiv
Year: 2014
Subjects: subject: Combinatorics (math.CO)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: Primary: 11B75, Secondary: 11B30, 11P70

description: Given an additively written abelian group $G$ and a set $X\subseteq G$, we let $\mathscr{B}(X)$ denote the monoid of zero-sum sequences over $X$ and $\mathsf{D}(X)$ the Davenport constant of $\mathscr{B}(X)$, namely the supremum of the positive integers $n$ for which there exists a sequence $x_1 \cdots x_n$ of $\mathscr{B}(X)$ such that $\sum_{i \in I} x_i \ne 0$ for each non-empty proper subset $I$ of $\{1, \ldots, n\}$. In this paper, we mainly investigate the case when $G$ is a power of $\mathbb{Z}$ and $X$ is a box (i.e., a product of intervals of $G$). Some mixed sets (e.g., the product of a group by a box) are studied too, and some inverse results are obtained.
description: 23 pages, no figures; fixed minor mistakes; added a new reference
Generalised Score Distribution: A Two-Parameter Discrete Distribution Accurately Describing Responses from Quality of Experience Subjective Experiments
Creators: name: Nawała, Jakub
name: Janowski, Lucjan
name: Ćmiel, Bogdan
name: Rusek, Krzysztof
name: Pérez, Pablo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: Subjective responses from Multimedia Quality Assessment (MQA) experiments are conventionally analysed with methods not suitable for the data type these responses represent. Furthermore, obtaining subjective responses is resource intensive. A method allowing reuse of existing responses would be thus beneficial. Applying improper data analysis methods leads to difficult to interpret results. This encourages drawing erroneous conclusions. Building upon existing subjective responses is resource friendly and helps develop machine learning (ML) based visual quality predictors. We show that using a discrete model for analysis of responses from MQA subjective experiments is feasible. We indicate that our proposed Generalised Score Distribution (GSD) properly describes response distributions observed in typical MQA experiments. We highlight interpretability of GSD parameters and indicate that the GSD outperforms the approach based on sample empirical distribution when it comes to bootstrapping. We evidence that the GSD outcompetes the state-of-the-art model both in terms of goodness-of-fit and bootstrapping capabilities. To do all of that we analyse more than one million subjective responses from more than 30 subjective experiments. Furthermore, we make the code implementing the GSD model and related analyses available through our GitHub repository: https://github.com/Qub3k/subjective-exp-consistency-check
description: 15 pages, 6 figures. Under review in IEEE Transactions on Multimedia
Topological Effects in Chiral Symmetric Driven Systems
Creators: name: Ho, Derek Y. H.
name: Gong, Jiangbin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Recent years have seen a strong interest in topological effects within periodically driven systems. In this work, we explore topological effects in two closely related 2-dimensional driven systems described by Floquet operators possessing chiral symmetry (CS). Our numerical and analytical results suggest the following. Firstly, the CS is associated with the existence of the anomalous counter-propagating (ACP) modes reported recently. Specifically, we show that a particular form of CS protects the ACP modes occurring at quasienergies of $\pm π$. We also find that these modes are only present along selected boundaries, suggesting that they are a weak topological effect. Secondly, we find that CS can give rise to protected $0$ and $π$ quasienergy modes, and that the number of these modes may increase without bound as we tune up certain system parameters. Like the ACP modes, these $0$ and $π$ modes also appear only along selected boundaries and thus appear to be a weak topological effect. To our knowledge, this work represents the first detailed study of weak topological effects in periodically driven systems. Our findings add to the still-growing knowledge on driven topological systems.
description: 37 pages, 5 figures, to appear in Physical Review B
Klassifizierung von Glottiscysfunktionen mit Hilfe der Elektroglottographie [Classification of glottal dysfunctions on the basis of electroglottography]
Creators: name: Hacki, Tamas
Publisher: name: Universität Regensburg
Year: 1989
Subjects: subject: 610 Medizin
subject: Electrodiagnosis
subject: Glottis/physiopathology
subject: Humans
subject: Muscle Contraction
subject: Voice Disorders/physiopathology

description: The close relationship between the muscular tension at the level of the glottis and the glottal opening time, closing time, and open quotient encourages the use of these temporal measures as an aid in classifying functional dysphonias. The validity of a 'quasi-open quotient' (QOQ) derived from the electroglottogram was explored by means of a crescendo singing task at comfortable frequency. The pattern of QOQ change during the crescendo task was determined and the range of the variable measured. In normal speakers QOQ varied from 0.75 (at low vocal intensity) to 0.40 (at high intensity). In contrast, the range of QOQ values was significantly restricted in patients with hyper- and hypofunctional dysphonia. The electroglottographical curves were registered and documented by a computer system (IBM AT, Gould DASA).
In vivo analysis of hip joint loading on Nordic walking novices
Creators: name: Palmowski, Yannick
name: Popovic, Srdan
name: Schuster, Simone G.
name: Hardt, Sebastian
name: Damm, Philipp
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2021
Subjects: subject: Nordic walking (NW)
subject: hip joint loads
subject: postoperative physiotherapy
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::610 Medizin und Gesundheit

description: Objective: To evaluate the influence of Nordic walking (NW) on hip joint loads in order to determine whether it can be safely performed during postoperative physiotherapy in patients after orthopeadic surgery of the hip. Methods: Internal hip joint loads were directly measured in vivo in 6 patients using instrumented hip prostheses during NW and ordinary walking (OW). All patients received training in two different NW techniques (double-poling and the diagonal technique) by a certified NW instructor. Measurements were conducted on a treadmill at a speed of 4 km/h on level ground, at 10% inclination and at 10% slope as well as on a level lawn at a self chosen comfortable speed. Resultant contact force (F-res), bending moment (M-bend) and torsional torque (M-tors) were compared between NW and OW as well as between both NW techniques. Results: Joint loads showed a double peak pattern during all setups. Neither NW technique significantly influenced hip joint loads at the time of the first load peak during contralateral toe-off (CTO), which was also the absolute load peak, in comparison to OW. Compared to OW, double-poling significantly reduced F-res and M-bend at the time of the second load peak during the contralateral heel strike (CHS) on level ground both on the treadmill (- 6% and - 7%, respectively) and on the lawn (- 7% and - 9%). At 10% inclination, the diagonal technique increased F-res and M-bend at CHS (by + 6% and + 7%), but did not increase the absolute load peak at CTO. Conclusion: Joint loads during NW are comparable to those of OW. Therefore, NW can be considered a low-impact activity and seems to be safe for patients that are allowed full weight bearing, e.g. during postoperative rehabilitation after THA.
Pixle: a fast and effective black-box attack based on rearranging pixels
Creators: name: Pomponi, Jary
name: Scardapane, Simone
name: Uncini, Aurelio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Recent research has found that neural networks are vulnerable to several types of adversarial attacks, where the input samples are modified in such a way that the model produces a wrong prediction that misclassifies the adversarial sample. In this paper we focus on black-box adversarial attacks, that can be performed without knowing the inner structure of the attacked model, nor the training procedure, and we propose a novel attack that is capable of correctly attacking a high percentage of samples by rearranging a small number of pixels within the attacked image. We demonstrate that our attack works on a large number of datasets and models, that it requires a small number of iterations, and that the distance between the original sample and the adversarial one is negligible to the human eye.
Raman study of magnetic excitations and magneto-elastic coupling in alpha-SrCr2O4
Creators: name: Valentine, Michael
name: Koohpayeh, Seyed
name: Mourigal, Martin
name: McQueen, Tyrel M.
name: Broholm, Collin
name: Drichko, Natalia
name: Dutton, Siân E.
name: Cava, Robert J.
name: Birol, Turan
name: Das, Hena
name: Fennie, Craig J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using Raman spectroscopy, we investigate the lattice phonons, magnetic excitations, and magneto-elastic coupling in the distorted triangular-lattice Heisenberg antiferromagnet alpha-SrCr2O4, which develops helical magnetic order below 43 K. Temperature dependent phonon spectra are compared to predictions from density functional theory calculations which allows us to assign the observed modes and identify weak effects arising from coupled lattice and magnetic degrees of freedom. Raman scattering associated with two-magnon excitations is observed at 20 meV and 40 meV. These energies are in general agreement with our ab-initio calculations of exchange interactions and earlier theoretical predictions of the two-magnon Raman response of triangular-lattice antiferromagnets. The temperature dependence of the two-magnon excitations indicates that spin correlations persist well above the Néel temperature.
Effects of person-environment fit of gender-role orientation on burnout, engagement and hair steroids as stress biomarkers among women
Creators: name: Wacker, Eva
name: Fischer, Axel
name: Schorlemmer, Julia
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2021
Subjects: subject: Person-environment fit
subject: Gender-role orientation
subject: Burnout
subject: Engagement
subject: Hair steroids
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::610 Medizin und Gesundheit

description: Background: Analysis on gender related differences in occupational stress and burnout levels usually reveal higher occupational stress and burnout levels for women compared to men, especially in male-dominated working environments. In opposition to group differentiation, more specific gender-related dimensions feminity and masculinity were used in the study to describe individual and work environment characteristics and analyze their effects. Methods: In a cross-sectional design, survey results were linked to steroid levels in hair samples. Data was collected in a German medical services company with 146 employed women age 22-66 years (M = 40.48, SD = 10.38), 58 of them provided hair samples for steroid detection. Feminity and masculinity were measured by Gender Role Orientation Scale GTS+. Two Person-Environment fit scores in feminity and masculinity were calculated by subtracting individual from environment values. Both fit scores were proved as predictors in hierarchical linear regression models predicting burnout and work engagement as well as hair steroids cortisol, cortisone, DHEA, testosterone and progesterone detected by Liquid Chromatography-Mass Spectrometry (LC-MS/MS) as stress biomarkers. Bivariate correlations as well as moderator and mediator analysis were implemented. Results: After considering age, role clarity, and work organization, Person-Environment fit in feminity still added significant variance explanation (beta = .23, increment R-2 = .05, p = .003) for burnout. Person-Environment fit in feminity also explained poor variance in work engagement (beta = -.29, R-2 = .09, p < .001). Person-Environment fit in masculinity added considerable variance explanation (beta = .34, increment R-2 = .12, p = 0.018) to cortisol levels after including quantitative demands to the model. Conclusions: Person-Environment fit in feminity might be inspected as a predictor for burnout and work engagement. Person-Environment fit in masculinity can be taken into consideration as a predictor for hair cortisol as stress biomarker. Feminity and masculinity can be used as personality traits as well as characteristics of work environment, thus providing a particular gender-role related method of differentiation within gender groups. Also, specific methods could be derived for stress and burnout prevention and promotion of work engagement. Representative population studies with bigger samples and longitudinal surveys are needed to better explore the benefits and limitations of this approach.
Non-linear growth and condensation in multiplex networks
Creators: name: Nicosia, Vincenzo
name: Bianconi, Ginestra
name: Latora, Vito
name: Barthelemy, Marc
Publisher: name: arXiv
Year: 2013
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Different types of interactions coexist and coevolve to shape the structure and function of a multiplex network. We propose here a general class of growth models in which the various layers of a multiplex network coevolve through a set of non-linear preferential attachment rules. We show, both numerically and analytically, that by tuning the level of non-linearity these models allow to reproduce either homogeneous or heterogeneous degree distributions, together with positive or negative degree correlations across layers. In particular, we derive the condition for the appearance of a condensed state in which one node in each layer attracts an extensive fraction of all the edges.
description: 15 pages, 9 figures
The tidal effects in the Finite-volumE Sea ice–Ocean Model (FESOM2.1): a comparison between parameterised tidal mixing and explicit tidal forcing
Creators: name: Song, Pengyang
name: Sidorenko, Dmitry
name: Scholz, Patrick
name: Thomas, Maik
name: Lohmann, Gerrit
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: tides
subject: effect
subject: ocean
subject: 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften

description: Tides are proved to have a significant effect on the ocean and climate. Previous modelling research either adds a tidal mixing parameterisation or an explicit tidal forcing to the ocean models. However, no research compares the two approaches in the same framework. Here we implement both schemes in a general ocean circulation model and assess both methods by comparing the results. The aspects for comparison involve hydrography, sea ice, meridional overturning circulation (MOC), vertical diffusivity, barotropic streamfunction and energy diagnostics. We conclude that although the mesh resolution is poor in resolving internal tides in most mid-latitude and shelf-break areas, explicit tidal forcing still shows stronger tidal mixing at the Kuril–Aleutian Ridge and the Indonesian Archipelago than the tidal mixing parameterisation. Beyond that, the explicit tidal forcing method leads to a stronger upper cell of the Atlantic MOC by enhancing the Pacific MOC and the Indonesian Throughflow. Meanwhile, the tidal mixing parameterisation leads to a stronger lower cell of the Atlantic MOC due to the tidal mixing in deep oceans. Both methods maintain the Antarctic Circumpolar Current at a higher level than the control run by increasing the meridional density gradient. We also show several phenomena that are not considered in the tidal mixing parameterisation, for example, the changing of energy budgets in the ocean system, the bottom drag induced mixing on the continental shelves and the sea ice transport by tidal motions. Due to the limit of computational capacity, an internal-tide-resolving simulation is not feasible for climate studies. However, a high-resolution short-term tidal simulation is still required to improve parameters and parameterisation schemes in climate studies.
Microglia as target for anti-inflammatory approaches to prevent secondary brain injury after subarachnoid hemorrhage (SAH)
Creators: name: Heinz, Rebecca
name: Brandenburg, Susan
name: Nieminen-Kelhä, Melina
name: Kremenetskaia, Irina
name: Boehm-Sturm, Philipp
name: Vajkoczy, Peter
name: Schneider, Ulf C.
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2021
Subjects: subject: Subarachnoid hemorrhage
subject: Inflammation
subject: Microglia
subject: Secondary brain injury
subject: Inflammatory preconditioning
subject: CSF1-Receptor
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::610 Medizin und Gesundheit

description: Background: Microglia-driven cerebral spreading inflammation is a key contributor to secondary brain injury after SAH. Genetic depletion or deactivation of microglia has been shown to ameliorate neuronal cell death. Therefore, clinically feasible anti-inflammatory approaches counteracting microglia accumulation or activation are interesting targets for SAH treatment. Here, we tested two different methods of interference with microglia-driven cerebral inflammation in a murine SAH model: (i) inflammatory preconditioning and (ii) pharmacological deactivation. Methods: 7T-MRI-controlled SAH was induced by endovascular perforation in four groups of C57Bl/6 mice: (i) Sham-operation, (ii) SAH naive, (iii) SAH followed by inflammatory preconditioning (LPS intraperitoneally), and (iv) SAH followed by pharmacological microglia deactivation (colony-stimulating factor-1 receptor-antagonist PLX3397 intraperitoneally). Microglia accumulation and neuronal cell death (immuno-fluorescence), as well as activation status (RT-PCR for inflammation-associated molecules from isolated microglia) were recorded at day 4 and 14. Toll-like receptor4 (TLR4) status was analyzed using FACS. Results: Following SAH, significant cerebral spreading inflammation occurred. Microglia accumulation and pro-inflammatory gene expression were accompanied by neuronal cell death with a maximum on day 14 after SAH. Inflammatory preconditioning as well as PLX3397-treatment resulted in significantly reduced microglia accumulation and activation as well as neuronal cell death. TLR4 surface expression in preconditioned animals was diminished as a sign for receptor activation and internalization. Conclusions: Microglia-driven cerebral spreading inflammation following SAH contributes to secondary brain injury. Two microglia-focused treatment strategies, (i) inflammatory preconditioning with LPS and (ii) pharmacological deactivation with PLX3397, led to significant reduction of neuronal cell death. Increased internalization of inflammation-driving TLR4 after preconditioning leaves less receptor molecules on the cell surface, providing a probable explanation for significantly reduced microglia activation. Our findings support microglia-focused treatment strategies to overcome secondary brain injury after SAH. Delayed inflammation onset provides a valuable clinical window of opportunity.
Boosting the accuracy of SPH techniques: Newtonian and special-relativistic tests
Creators: name: Rosswog, S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We study the impact of different discretization choices on the accuracy of SPH and we explore them in a large number of Newtonian and special-relativistic benchmark tests. As a first improvement, we explore a gradient prescription that requires the (analytical) inversion of a small matrix. For a regular particle distribution this improves gradient accuracies by approximately ten orders of magnitude and the SPH formulations with this gradient outperform the standard approach in all benchmark tests. Second, we demonstrate that a simple change of the kernel function can substantially increase the accuracy of an SPH scheme. While the "standard" cubic spline kernel generally performs poorly, the best overall performance is found for a high-order Wendland kernel which allows for only very little velocity noise and enforces a very regular particle distribution, even in highly dynamical tests. Third, we explore new SPH volume elements that enhance the treatment of fluid instabilities and, last, but not least, we design new dissipation triggers. They switch on near shocks and in regions where the flow --without dissipation-- starts to become noisy. The resulting new SPH formulation yields excellent results even in challenging tests where standard techniques fail completely.
description: accepted for publication in MNRAS
Coupling of (ferro)electricity and magnetism through Coulomb blockade in Composite Multiferroics
Creators: name: Udalov, O. G.
name: Chtchelkatchev, N. M.
name: Beloborodov, I. S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Composite multiferroics are materials exhibiting the interplay of ferroelectricity, magnetism, and strong electron correlations. Typical example --- magnetic nano grains embedded in a ferroelectric matrix. Coupling of ferroelectric and ferromagnetic degrees of freedom in these materials is due to the influence of ferroelectric matrix on the exchange coupling constant via screening of the intragrain and intergrain Coulomb interaction. Cooling typical magnetic materials the ordered state appears at lower temperatures than the disordered state. We show that in composite multiferroics the ordered magnetic phase may appear at higher temperatures than the magnetically disordered phase. In non-magnetic materials such a behavior is known as inverse phase transition.
description: 5 pages, 4 figures
Conditional Motion In-betweening
Creators: name: Kim, Jihoon
name: Byun, Taehyun
name: Shin, Seungyoun
name: Won, Jungdam
name: Choi, Sungjoon
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: Motion in-betweening (MIB) is a process of generating intermediate skeletal movement between the given start and target poses while preserving the naturalness of the motion, such as periodic footstep motion while walking. Although state-of-the-art MIB methods are capable of producing plausible motions given sparse key-poses, they often lack the controllability to generate motions satisfying the semantic contexts required in practical applications. We focus on the method that can handle pose or semantic conditioned MIB tasks using a unified model. We also present a motion augmentation method to improve the quality of pose-conditioned motion generation via defining a distribution over smooth trajectories. Our proposed method outperforms the existing state-of-the-art MIB method in pose prediction errors while providing additional controllability.
Aktueller Stand: Caden
Creators: name: Bronger, Torsten
name: Nestler, Britta
name: Selzer, Michael
name: Schlenz, Hartmut
name: Manideep Jayavarapu
name: Flemming, Michael
Publisher: name: Zenodo
Year: 2021
Subjects: knowledge graph
RDF
semantic web
electronic lab notebook

description: Current status of the task area “Caden” in the NFDI4Ing consortium.
description: The authors would like to thank the Federal Government and the Heads of Government of the Länder, as well as the Joint Science Conference (GWK), for their funding and support within the framework of the NFDI4Ing consortium. Funded by the German Research Foundation (DFG) – 442146713.
Layer Systems for Proving Confluence
Creators: name: Felgenhauer, Bertram
name: Middeldorp, Aart
name: Zankl, Harald
name: van Oostrom, Vincent
Publisher: name: arXiv
Year: 2014
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: F.4.1

description: We introduce layer systems for proving generalizations of the modularity of confluence for first-order rewrite systems. Layer systems specify how terms can be divided into layers. We establish structural conditions on those systems that imply confluence. Our abstract framework covers known results like modularity, many-sorted persistence, layer-preservation and currying. We present a counterexample to an extension of persistence to order-sorted rewriting and derive new sufficient conditions for the extension to hold. All our proofs are constructive.
Genome-level analyses resolve an ancient lineage of symbiotic ascomycetes
Creators: name: Díaz-Escandón, David
name: Tagirdzhanova, Gulnara
name: Vanderpool, Dan
name: Allen, Carmen C. G.
name: Aptroot, André
name: Češka, Oluna
name: Hawksworth, David L.
name: Huereca, Alejandro
name: Knudsen, Kerry
name: Lücking, Robert
Publisher: name: Freie Universität Berlin
Year: 2022
Subjects: subject: carbohydrate-active enzymes
subject: comparative genomics
subject: endosymbiosis
subject: functional annotation
subject: fungal genomes
subject: lichens
subject: genome reduction
subject: Lichinomycetes
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie::579 Mikroorganismen, Pilze, Algen

description: Ascomycota account for about two-thirds of named fungal species.1 Over 98% of known Ascomycota belong to the Pezizomycotina, including many economically important species as well as diverse pathogens, decomposers, and mutualistic symbionts.2 Our understanding of Pezizomycotina evolution has until now been based on sampling traditionally well-defined taxonomic classes.3,4,5 However, considerable diversity exists in undersampled and uncultured, putatively early-diverging lineages, and the effect of these on evolutionary models has seldom been tested. We obtained genomes from 30 putative early-diverging lineages not included in recent phylogenomic analyses and analyzed these together with 451 genomes covering all available ascomycete genera. We show that 22 of these lineages, collectively representing over 600 species, trace back to a single origin that diverged from the common ancestor of Eurotiomycetes and Lecanoromycetes over 300 million years BP. The new clade, which we recognize as a more broadly defined Lichinomycetes, includes lichen and insect symbionts, endophytes, and putative mycorrhizae and encompasses a range of morphologies so disparate that they have recently been placed in six different taxonomic classes. To test for shared hidden features within this group, we analyzed genome content and compared gene repertoires to related groups in Ascomycota. Regardless of their lifestyle, Lichinomycetes have smaller genomes than most filamentous Ascomycota, with reduced arsenals of carbohydrate-degrading enzymes and secondary metabolite gene clusters. Our expanded genome sample resolves the relationships of numerous “orphan” ascomycetes and establishes the independent evolutionary origins of multiple mutualistic lifestyles within a single, morphologically hyperdiverse clade of fungi.