4 research outputs found
A model for soap film dynamics with evolving thickness
Previous research on animations of soap bubbles, films, and foams largely focuses on the motion and geometric shape of the bubble surface. These works neglect the evolution of the bubble’s thickness, which is normally responsible for visual phenomena like surface vortices, Newton’s interference patterns, capillary waves, and deformation-dependent rupturing of films in a foam. In this paper, we model these natural phenomena by introducing the film thickness as a reduced degree of freedom in the Navier-Stokes equations and deriving their equations of motion. We discretize the equations on a nonmanifold triangle mesh surface and couple it to an existing bubble solver. In doing so, we also introduce an incompressible fluid solver for 2.5D films and a novel advection algorithm for convecting fields across non-manifold surface junctions. Our simulations enhance state-of-the-art bubble solvers with additional effects caused by convection, rippling, draining, and evaporation of the thin film
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BGLF2 Increases Infectivity of Epstein-Barr Virus by Activating AP-1 upon De Novo Infection
ABSTRACT Epstein-Barr virus (EBV) is a human gammaherpesvirus that causes infectious mononucleosis and several malignancies, such as endemic Burkitt lymphoma and nasopharyngeal carcinoma. Herpesviruses carry genes that can modify cell functions, including transcription and ubiquitination, thereby facilitating viral growth and survival in infected cells. Using a reporter screening system, we revealed the involvement of several EBV gene products in such processes. Of these, BGLF2 activated the AP-1 signaling pathway through phosphorylation of p38 and c-Jun N-terminal kinase (JNK). Knockout of the BGLF2 gene did not affect viral gene expression and viral genome DNA replication, but resulted in marked reduction of progeny titer. We also found that the BGLF2 disruption resulted in significant loss of infectivity upon de novo infection. Interestingly, expression of a binding partner, BKRF4, repressed the activation of AP-1 by BGLF2. These results shed light on the physiological role of the tegument protein BGLF2. IMPORTANCE: Epstein-Barr virus (EBV), an oncogenic gammaherpesvirus, carries ~80 genes. While several genes have been investigated extensively, most lytic genes remain largely unexplored. Therefore, we cloned 71 EBV lytic genes into an expression vector and used reporter assays to screen for factors that activate signal transduction pathways, viral and cellular promoters. BGLF2 activated the AP-1 signaling pathway, likely by interacting with p38 and c-Jun N-terminal kinase (JNK), and increased infectivity of the virus. We also revealed that BKRF4 can negatively regulate AP-1 activity. Therefore, it is suggested that EBV exploits and modifies the AP-1 signaling pathway for its replication and survival
Calculation of 1/<i>f</i> Fluctuation from Sound Signal and Comfort Evaluation
Providing a comfortable sound for users is an important factor for high-value products. Therefore, many studies have investigated pleasant sound levels for developing and manufacturing new products. Notably, sounds containing 1/f fluctuations provide a relaxing effect in humans. There are many studies on the influence of sound signals, including 1/f fluctuations; however, the verification of fluctuations, including sound signals, has not been performed. In this study on fluctuation, the discrete Fourier transform was used to directly calculate the time of the sound signal. We evaluated the duration of music and the 1/f fluctuation via the discrete Fourier transform using the time history of the music data. Furthermore, we investigated the relaxation effect of music containing a 1/f fluctuation. We determined a person’s comfort according to the difference in the calculated fluctuation coefficient by subjectively evaluating the comfort felt by people when listening to music with two different fluctuation coefficients, and we examined the improvement in the fluctuation coefficient and human comfort
Calculation of 1/f Fluctuation from Sound Signal and Comfort Evaluation
Providing a comfortable sound for users is an important factor for high-value products. Therefore, many studies have investigated pleasant sound levels for developing and manufacturing new products. Notably, sounds containing 1/f fluctuations provide a relaxing effect in humans. There are many studies on the influence of sound signals, including 1/f fluctuations; however, the verification of fluctuations, including sound signals, has not been performed. In this study on fluctuation, the discrete Fourier transform was used to directly calculate the time of the sound signal. We evaluated the duration of music and the 1/f fluctuation via the discrete Fourier transform using the time history of the music data. Furthermore, we investigated the relaxation effect of music containing a 1/f fluctuation. We determined a person’s comfort according to the difference in the calculated fluctuation coefficient by subjectively evaluating the comfort felt by people when listening to music with two different fluctuation coefficients, and we examined the improvement in the fluctuation coefficient and human comfort