5,243 research outputs found
Relaxion and light (pseudo)scalars at the HL-LHC and lepton colliders
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 . 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 and 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?
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
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
Wellbeing impacts of city policies for reducing greenhouse gas emissions
To mitigate climate change, city authorities are developing policies in areas such as transportation, housing and energy use, to reduce greenhouse gas emissions. In addition to their effects on greenhouse gas emissions, these policies are likely to have consequences for the wellbeing of their populations for example through changes in opportunities to take physical exercise. In order to explore the potential consequences for wellbeing, we first explore what âwellbeingâ is and how it can be operationalised for urban planners. In this paper, we illustrate how wellbeing can be divided into objective and subjective aspects which can be measured quantitatively; our review of measures informs the development of a theoretical model linking wellbeing to policies which cities use to reduce greenhouse gas emissions. Finally, we discuss the extent to which the links proposed in the conceptual model are supported by the literature and how cities can assess wellbeing implications of policies.</p
A Versatile, Voltage-Pulse Based Read and Programming Circuit for Multi-Level RRAM Cells
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
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
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
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