Quantum electrodynamics of relativistic bound states with cutoffs

We consider an Hamiltonian with ultraviolet and infrared cutoffs, describing the interaction of relativistic electrons and positrons in the Coulomb potential with photons in Coulomb gauge. The interaction includes both interaction of the current density with transversal photons and the Coulomb interaction of charge density with itself. We prove that the Hamiltonian is self-adjoint and has a ground state for sufficiently small coupling constants.Comment: To appear in "Journal of Hyperbolic Differential Equation

Feasibility study for a numerical aerodynamic simulation facility. Volume 1

A Numerical Aerodynamic Simulation Facility (NASF) was designed for the simulation of fluid flow around three-dimensional bodies, both in wind tunnel environments and in free space. The application of numerical simulation to this field of endeavor promised to yield economies in aerodynamic and aircraft body designs. A model for a NASF/FMP (Flow Model Processor) ensemble using a possible approach to meeting NASF goals is presented. The computer hardware and software are presented, along with the entire design and performance analysis and evaluation

Hypertonicity-affected genes are differentially expressed in clear cell renal cell carcinoma and correlate with cancer-specific survival

The heterogeneity of renal cell carcinoma (RCC) subtypes reflects the cell type of origin in the nephron, with consequences for therapy and prognosis. The transcriptional cues that determine segment-specific gene expression patterns are poorly understood. We recently showed that hypertonicity in the renal medulla regulates nephron-specific gene expression. Here, we analyzed a set of 223 genes, which were identified in the present study by RNA-Seq to be differentially expressed by hypertonicity, for the prediction of cancer-specific survival (CSS). Cluster analyses of these genes showed discrimination between tumor and non-tumor samples of clear cell RCC (ccRCC). Refinement of this gene signature to a four-gene score (OSM score) through statistical analyses enabled prediction of CSS in ccRCC patients of The Cancer Genome Atlas (TCGA) (n = 436) in univariate (HR = 4.1; 95% CI: 2.78-6.07; p = 4.39 × 10(-13)), and multivariate analyses including primary tumor (T); regional lymph node (N); distant metastasis (M); grading (G)(p = 2.3 × 10(-5)). The OSM score could be validated in an independent ccRCC study (n = 52) in univariate (HR = 1.29; 95% CI = 1.05-1.59; p = 0.011) and multivariate analyses (p = 0.016). Cell culture experiments using RCC cell lines demonstrated that the expression of the tumor suppressor ELF5 could be restored by hypertonicity. The innovation of our novel gene signature is that these genes are physiologically regulated only by hypertonicity, thereby providing the possibility to be targeted for therapy

Rhythm in the speech of a person with right hemisphere damage: Applying the pairwise variability index

Although several aspects of prosody have been studied in speakers with right hemisphere damage (RHD), rhythm remains largely uninvestigated. This study compares the rhythm of an Australian English speaker with right hemisphere damage (due to a stroke, but with no concomitant dysarthria) to that of a neurologically unimpaired individual. The speakers' rhythm is compared using the pairwise variability index (PVI) which allows for an acoustic characterization of rhythm by comparing the duration of successive vocalic and intervocalic intervals. A sample of speech from a structured interview between a speech and language therapist and each participant was analysed. Previous research has shown that speakers with RHD may have difficulties with intonation production, and therefore it was hypothesized that there may also be rhythmic disturbance. Results show that the neurologically normal control uses a similar rhythm to that reported for British English (there are no previous studies available for Australian English), whilst the speaker with RHD produces speech with a less strongly stress-timed rhythm. This finding was statistically significant for the intervocalic intervals measured (t(8) = 4.7, p < .01), and suggests that some aspects of prosody may be right lateralized for this speaker. The findings are discussed in relation to previous findings of dysprosody in RHD populations, and in relation to syllable-timed speech of people with other neurological conditions

OpenVirtualObjects: An open set of standardized and validated 3D household objects for virtual reality-based research, assessment, and therapy

Virtual reality (VR) technology provides clinicians, therapists, and researchers with new opportunities to observe, assess, and train behavior in realistic yet well-controlled environments. However, VR also comes with a number of challenges. For example, compared to more abstract experiments and tests on 2D computer screens, VR-based tasks are more complex to create, which can make it more expensive and time-consuming. One way to overcome these challenges is to create, standardize, and validate VR content and to make it openly available for researchers and clinicians. Here we introduce the OpenVirtualObjects (OVO), a set of 124 realistic 3D household objects that people encounter and use in their everyday lives. The objects were rated by 34 younger and 25 older adults for recognizability, familiarity, details (i.e., visual complexity), contact, and usage (i.e., frequency of usage in daily life). All participants also named and categorized the objects. We provide the data and the experiment- and analysis code online. With OVO, we hope to facilitate VR-based research and clinical applications. Easy and free availability of standardized and validated 3D objects can support systematic VR-based studies and the development of VR-based diagnostics and therapeutic tools

OpenVirtualObjects (OVO): An open set of standardized and validated 3D household objects for virtual reality-based research, assessment, and therapy

Virtual reality (VR) technology provides clinicians, therapists, and researchers with new opportunities to observe, assess, and train behaviour in realistic yet well-controlled environments. However, VR also comes with a number of challenges. For example, compared to more abstract experiments and tests on 2D computer screens, VR-based tasks are more complex to create, which can make it more expensive and time-consuming. One way to overcome these challenges is to create, standardize, and validate VR content and to make it openly available for researchers and clinicians. Here we introduce the OpenVirtualObjects (OVO), a set of 124 realistic 3D household objects that people encounter and use in their everyday lives. The objects were rated by 34 younger and 25 older adults for recognizability, familiarity, details (i.e., visual complexity), contact, and usage (i.e., frequency of usage in daily life). All participants also named and categorized the objects. We provide the data and the experiment- and analysis code online. With OVO, we hope to facilitate VR-based research and clinical applications. Easy and free availability of standardized and validated 3D objects can support systematic VR-based studies and the development of VR-based diagnostics and therapeutic tools

Constraints on new interactions from neutron scattering experiments

Constraints for the constants of hypothetical Yukawa-type corrections to the Newtonian gravitational potential are obtained from analysis of neutron scattering experiments. Restrictions are obtained for the interaction range between 10^{-12} and 10^{-7} cm, where Casimir force experiments and atomic force microscopy are not sensitive. Experimental limits are obtained also for non-electromagnetic inverse power law neutron-nucleus potential. Some possibilities are discussed to strengthen these constraints.Comment: 18 pages, 3 figure

Formation of Ejecta and Dust Pond Deposits on Asteroid Vesta

Dust and melt ponds have been studied on planetary bodies including Eros, Itokawa, and the Moon. However, depending on the nature of the regolith material properties and the location of the planetary body, the formation mechanism of the ponded features varies. On Eros and Itokawa, ponded features are formed from dry regolith materials whereas on the Moon similar features are thought to be produced by ejecta melt. On the surface of Vesta, we have identified type 1, ejecta ponds, and type 2, dust ponds. On Vesta type 1 pond are located in the vicinity of ejecta melt of large impact craters. The material is uniformly distributed across the crater floor producing smooth pond surfaces which have a constant slope and shallow depth. The hosting crater of melt-like ponds has a low raised rim and is located on relatively low elevated regions. Whereas, the type 2 ponds on Vesta reveal an undulating surface that is frequently displaced from the crater center or extends toward the crater wall with an abruptly changing slope. We suggested that for the production of the type 2 ponds, localized seismic diffusion and volatile-induced fluidization may be responsible for Vesta. Due to Vesta's large size (in comparison to Eros and Itokawa), the surface may have experienced local-scale rare high-amplitude seismic diffusion which was sufficient to drift fine material. Similarly, short-lived volatile activities were capable to transfer dusty material on to the surface. Segregation and smoothing of transferred material lack further surface activities, hindering the formation of smooth morphology

Electromagnetic Form Factors of the Nucleon in an Improved Quark Model

Nucleon electromagnetic form factors are studied in the cloudy bag model (CBM) with center-of-mass and recoil corrections. This is the first presentation of a full set of nucleon form factors using the CBM. The center of mass motion is eliminated via several different momentum projection techniques and the results are compared. It is found that the shapes of these form factors are significantly improved with respect to the experimental data if the Lorentz contraction of the internal structure of the baryon is also appropriately taken into account.Comment: revtex, 28 pages, 8 ps figs include