4,861 research outputs found

    Relaxion and light (pseudo)scalars at the HL-LHC and lepton colliders

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    We study the potential of future lepton colliders, running at the Z-pole and above, and the High-Luminosity LHC to search for the relaxion and other light scalars ϕ\phi. We investigate the interplay of direct searches and precision observables for both CP-even and -odd couplings. In particular, precision measurements of exotic Z-decays, Higgs couplings, the exotic Higgs decay into a relaxion pair and associated ZϕZ\phi and γϕ\gamma \phi production are promising channels to yield strong bounds.Comment: 27 pages + references, 5 figures, 2 table

    What are the microscopic events of colloidal membrane fouling?

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    Due to the complex interplay between surface adsorption and hydrodynamic interactions, representative microscopic mechanisms of colloidal membrane fouling are still not well understood. Numerical simulations overcome experimental limitations such as the temporal and spatial resolution of microscopic events during colloidal membrane fouling: they help to gain deeper insight into fouling processes. This study uses coupled computational fluid dynamics - discrete element methods (CFD-DEM) simulations to examine mechanisms of colloidal fouling in a microfluidic architecture mimicking a porous microfiltration membrane. We pay special attention to how particles can overcome energy barriers leading to adsorption and desorption with each other and with the external and internal membrane surface. Interparticle interaction leads to a transition from the secondary to the primary minimum of the DLVO potential. Adsorbed particles can show re-entrainment or they can glide downstream. Since particles mainly re-suspend as clusters, the inner pore geometry significantly affects the fouling behavior. The findings allow a basic understanding of microscopic fouling events during colloidal filtration. The methodology enables future systematic studies on the interplay of hydrodynamic conditions and surface energy contributions represented by potentials for soft and patchy colloids

    Endurance of quantum coherence due to particle indistinguishability in noisy quantum networks

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    Quantum coherence, the physical property underlying fundamental phenomena such as multi-particle interference and entanglement, has emerged as a valuable resource upon which modern technologies are founded. In general, the most prominent adversary of quantum coherence is noise arising from the interaction of the associated dynamical system with its environment. Under certain conditions, however, the existence of noise may drive quantum and classical systems to endure intriguing nontrivial effects. In this vein, here we demonstrate, both theoretically and experimentally, that when two indistinguishable non-interacting particles co-propagate through quantum networks affected by non-dissipative noise, the system always evolves into a steady state in which coherences accounting for particle indistinguishabilty perpetually prevail. Furthermore, we show that the same steady state with surviving quantum coherences is reached even when the initial state exhibits classical correlations.Comment: arXiv admin note: substantial text overlap with arXiv:1709.0433

    A Versatile, Voltage-Pulse Based Read and Programming Circuit for Multi-Level RRAM Cells

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    In this work, we present an integrated read and programming circuit for Resistive Random Access Memory (RRAM) cells. Since there are a lot of different RRAM technologies in research and the process variations of this new memory technology often spread over a wide range of electrical properties, the proposed circuit focuses on versatility in order to be adaptable to different cell properties. The circuit is suitable for both read and programming operations based on voltage pulses of flexible length and height. The implemented read method is based on evaluating the voltage drop over a measurement resistor and can distinguish up to eight different states, which are coded in binary, thereby realizing a digitization of the analog memory value. The circuit was fabricated in the 130 nm CMOS process line of IHP. The simulations were done using a physics-based, multi-level RRAM model. The measurement results prove the functionality of the read circuit and the programming system and demonstrate that the read system can distinguish up to eight different states with an overall resistance ratio of 7.9

    Inhibiting Multiple Deubiquitinases to Reduce Androgen Receptor Expression in Prostate Cancer Cells

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    Prostate cancer (PCa), a leading cause of cancer-related death in men, becomes resistant to androgen deprivation therapy by inducing androgen receptor (AR) activity, which is known as castration-resistant PCa (CRPC). Enzalutamide is an approved drug that inhibits AR activity and increases overall survival. However, resistance to enzalutamide develops rapidly often by increasing AR activity, suggesting that new therapies are required for CRPC. We investigated whether betulinic acid (BA), a small molecule from plants that inhibits multiple deubiquitinases (DUBs), reduces AR, and selectively kills PCa cells, can provide an adjuvant strategy for CRPC. Our data indicated that BA reduced AR protein stability and mRNA expression, making it an attractive agent for CRPC. BA decreased AR mRNA possibly by inhibiting a histone 2A DUB thereby increasing ubiquitinated histone 2A, a transcriptional repressor. We identified multiple and specific DUBs inhibited by BA either in PCa cells or using recombinant DUBs. Similar results were obtained using another multi-DUB inhibitor WP1130, suggesting that these DUB inhibitors can decrease AR expression and increase PCa-specific death. Our results also suggest that combining multi-DUB inhibitors BA or WP1130 with enzalutamide may provide a novel strategy for CRPC by further decreasing AR expression and increasing apoptotic cell death.</p

    Clasp2 ensures mitotic fidelity and prevents differentiation of epidermal keratinocytes

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    Epidermal homeostasis is tightly controlled by a balancing act of self-renewal or terminal differentiation of proliferating basal keratinocytes. An increase in DNA content as a consequence of a mitotic block is a recognized mechanism underlying keratinocyte differentiation, but the molecular mechanisms involved in this process are not yet fully understood. Using cultured primary keratinocytes, here we report that the expression of the mammalian microtubule and kinetochore-associated protein Clasp2 is intimately associated with the basal proliferative makeup of keratinocytes, and its deficiency leads to premature differentiation. Clasp2-deficient keratinocytes exhibit increased centrosomal numbers and numerous mitotic alterations, including multipolar spindles and chromosomal misalignments that overall result in mitotic stress and a high DNA content. Such mitotic block prompts premature keratinocyte differentiation in a p53-dependent manner in the absence of cell death. Our findings reveal a new role for Clasp2 in governing keratinocyte undifferentiated features and highlight the presence of surveillance mechanisms that prevent cell cycle entry in cells that have alterations in the DNA content.This work was supported by grants from the Spanish Ministerio de Economia y Competitividad (MINECO) [BFU2012-33910 and BFU2015-71376-R (MINECO/ European Regional Development Fund (ERDF), European Union) to M.P.-M.]. Deposited in PMC for immediate release.S

    Optimal interpolation of satellite and ground data for irradiance nowcasting at city scales

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    We use a Bayesian method, optimal interpolation, to improve satellite derived irradiance estimates at city-scales using ground sensor data. Optimal interpolation requires error covariances in the satellite estimates and ground data, which define how information from the sensor locations is distributed across a large area. We describe three methods to choose such covariances, including a covariance parameterization that depends on the relative cloudiness between locations. Results are computed with ground data from 22 sensors over a 75Ă—80 km area centered on Tucson, AZ, using two satellite derived irradiance models. The improvements in standard error metrics for both satellite models indicate that our approach is applicable to additional satellite derived irradiance models. We also show that optimal interpolation can nearly eliminate mean bias error and improve the root mean squared error by 50%
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