1,300 research outputs found
Dynamics of entanglement entropy of interacting fermions in a 1D driven harmonic trap
Following up on a recent analysis of two cold atoms in a time-dependent
harmonic trap in one dimension, we explore the entanglement entropy of two and
three fermions in the same situation when driven through a parametric
resonance. We find that the presence of such a resonance in the two-particle
system leaves a clear imprint on the entanglement entropy. We show how the
signal is modified by attractive and repulsive contact interactions, and how it
remains present for the three-particle system. Additionaly, we extend the work
of recent experiments to demonstrate how restricting observation to a limited
subsystem gives rise to locally thermal behavior.Comment: Proceedings of Lattice2017, Granada, Spai
Universal Wait-Free Memory Reclamation
In this paper, we present a universal memory reclamation scheme, Wait-Free
Eras (WFE), for deleted memory blocks in wait-free concurrent data structures.
WFE's key innovation is that it is completely wait-free. Although some prior
techniques provide similar guarantees for certain data structures, they lack
support for arbitrary wait-free data structures. Consequently, developers are
typically forced to marry their wait-free data structures with lock-free Hazard
Pointers or (potentially blocking) epoch-based memory reclamation. Since both
these schemes provide weaker progress guarantees, they essentially forfeit the
strong progress guarantee of wait-free data structures. Though making the
original Hazard Pointers scheme or epoch-based reclamation completely wait-free
seems infeasible, we achieved this goal with a more recent, (lock-free) Hazard
Eras scheme, which we extend to guarantee wait-freedom. As this extension is
non-trivial, we discuss all challenges pertaining to the construction of
universal wait-free memory reclamation.
WFE is implementable on ubiquitous x86_64 and AArch64 (ARM) architectures.
Its API is mostly compatible with Hazard Pointers, which allows easy
transitioning of existing data structures into WFE. Our experimental
evaluations show that WFE's performance is close to epoch-based reclamation and
almost matches the original Hazard Eras scheme, while providing the stronger
wait-free progress guarantee
The effects of the interaction of animals with children diagnosed with autism spectrum disorder and their families [abstract]
The CDC estimates that one in 110 children receive a diagnosis of Autism Spectrum Disorder (ASD) annually. Pet dogs have been found to be a social catalyst and service dogs have demonstrated measurable benefits for children with ASD. Given that 39% of American households have a dog, this survey investigates the perceived benefits and barriers of having a dog in a family with a child with ASD
Identifying plant cell wall remnants in detritus of a subtropical wetland with fluorescence labeling
Sediment accretion in wetlands represents a significant carbon burial pathway. While litter studies can quantify the loss rates of plant leaf material, those studies do not provide insight into the specific cell wall polymers being retained or lost within the detrital matrix. The Everglades ecosystem has been dramatically altered due to anthropogenic eutrophication and hydrologic modifications. The results are changes in macrophyte species composition and sediment accretion- and loss- rates. To improve ecological conditions, active management strategies are re-establishing open water slough environments. A question remains about the persistence of new- and old- plant cell wall material in sediments because of active management. In this pilot project we utilized immuno-fluorescence labeling with lectins applied to plant leaf material and detrital flocculent collected from created open and control plots in the Everglades to observe the presence, absence, and overlap of specific cell wall polymers between macrophytes and detrital flocculent in increasingly recalcitrant materials that would most likely contribute to peat accumulation. The persistence and loss of specific polymers between treatment and control plots provided insight into the differing levels of recalcitrance amongst plant cell walls and their relative potential as a carbon sink. This study provides a novel method for testing for the presence and persistence of specific cell wall polymers in detritus to gain a better understanding of plant material persistence in wetland ecosystems
Microtubules gate tau condensation to spatially regulate microtubule functions.
Tau is an abundant microtubule-associated protein in neurons. Tau aggregation into insoluble fibrils is a hallmark of Alzheimer's disease and other types of dementia1, yet the physiological state of tau molecules within cells remains unclear. Using single-molecule imaging, we directly observe that the microtubule lattice regulates reversible tau self-association, leading to localized, dynamic condensation of tau molecules on the microtubule surface. Tau condensates form selectively permissible barriers, spatially regulating the activity of microtubule-severing enzymes and the movement of molecular motors through their boundaries. We propose that reversible self-association of tau molecules, gated by the microtubule lattice, is an important mechanism of the biological functions of tau, and that oligomerization of tau is a common property shared between the physiological and disease-associated forms of the molecule
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