27 research outputs found
Minimum Light Numbers in the -Game and Lit-Only -Game on Unicyclic and Grid Graphs
Consider a graph each of whose vertices is either in the ON state or in the OFF state and call the resulting ordered bipartition into ON vertices and OFF vertices a configuration of the graph. A regular move at a vertex changes the states of the neighbors of that vertex and hence sends the current configuration to another one. A valid move is a regular move at an ON vertex. For any graph let be the minimum integer such that given any starting configuration of there must exist a sequence of valid moves which takes to a configuration with at most ON vertices provided there is a sequence of regular moves which brings to a configuration in which there are ON vertices. The shadow graph of a graph is obtained from by deleting all loops. We prove that if is unicyclic and give an example to show that the bound is tight. We also prove that if is a two-dimensional grid graph and if is a two-dimensional grid graph but not a path and
Does the lit-only restriction make any difference for the σ-game and σ+-game?
AbstractEach vertex in a simple graph is in one of two states: “on” or “off”. The set of all on vertices is called a configuration. In the σ-game, “pushing” a vertex v changes the state of all vertices in the open neighborhood of v, while in the σ+-game pushing v changes the state of all vertices in its closed neighborhood. The reachability question for these two games is to decide whether a given configuration can be reached from a given starting configuration by a sequence of pushes. We consider the lit-only restriction on these two games where a vertex can be pushed only if it is in the on state. We show that the lit-only restriction can make a big difference for reachability in the σ-game, but has essentially no effect in the σ+-game
Self-passivated freestanding superconducting oxide film for flexible electronics
The integration of high-temperature superconducting YBa2Cu3O6+x (YBCO) into
flexible electronic devices has the potential to revolutionize the technology
industry. The effective preparation of high-quality flexible YBCO films
therefore plays a key role in this development. We present a novel approach for
transferring water-sensitive YBCO films onto flexible substrates without any
buffer layer. Freestanding YBCO film on a polydimethylsiloxane substrate is
extracted by etching the Sr3Al2O6 sacrificial layer from the LaAlO3 substrate.
In addition to the obtained freestanding YBCO thin film having a Tc of 89.1 K,
the freestanding YBCO thin films under inward and outward bending conditions
have Tc of 89.6 K and 88.9 K, respectively. A comprehensive characterization
involving multiple experimental techniques including high-resolution
transmission electron microscopy, scanning electron microscopy, Raman and X-ray
Absorption Spectroscopy is conducted to investigate the morphology, structural
and electronic properties of the YBCO film before and after the extraction
process where it shows the preservation of the structural and superconductive
properties of the freestanding YBCO virtually in its pristine state. Further
investigation reveals the formation of a YBCO passivated layer serves as a
protective layer which effectively preserves the inner section of the
freestanding YBCO during the etching process. This work plays a key role in
actualizing the fabrication of flexible oxide thin films and opens up new
possibilities for a diverse range of device applications involving thin-films
and low-dimensional materials.Comment: 22 pages,4 figures,references adde
Retinal ganglion cell-inner plexiform layer, white matter hyperintensities, and their interaction with cognition in older adults
PurposeWe explored the interaction of optical coherence tomography (OCT) parameters and white matter hyperintensities with cognitive measures in our older adult cohort.MethodsThis observational study enrolled participants who underwent a comprehensive neuropsychological battery, structural 3-T brain magnetic resonance imaging (MRI), visual acuity examination, and OCT imaging. Cerebral small vessel disease (CSVD) markers were read on MR images; lacune, cerebral microbleeds (CMB), white matter hyperintensities (WMH), and enlarged perivascular spaces (EPVS), were defined according to the STRIVE standards. Retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thicknesses (μm) were measured on the OCT tool.ResultsOlder adults with cognitive impairment (CI) showed lower RNFL (p = 0.001), GCIPL (p = 0.009) thicknesses, and lower hippocampal volume (p = 0.004) when compared to non-cognitively impaired (NCI). RNFL (p = 0.006) and GCIPL thicknesses (p = 0.032) correlated with MoCA scores. GCIPL thickness (p = 0.037), total WMH (p = 0.003), PWMH (p = 0.041), and DWMH (p = 0.001) correlated with hippocampal volume in our older adults after adjusting for covariates. With hippocampal volume as the outcome, a significant interaction (p < 0.05) between GCIPL and PWMH and total WMH was observed in our older adults.ConclusionBoth GCIPL thinning and higher WMH burden (especially PWMH) are associated with hippocampal volume and older adults with both pathologies are more susceptible to subclinical cognitive decline
Direct observation of two-dimensional small polarons at correlated oxide interface
Two-dimensional (2D) perovskite oxide interfaces are ideal systems where
diverse emergent properties can be uncovered.The formation and modification of
polaronic properties due to short-range strong charge-lattice interactions of
2D interfaces remains hugely intriguing.Here, we report the direct observation
of small-polarons at the LaAlO3/SrTiO3 (LAO/STO) conducting interface using
high-resolution spectroscopic ellipsometry.First-principles investigations
further reveals that strong coupling between the interfacial electrons and the
Ti-lattice result in the formation of localized 2D small polarons.These
findings resolve the longstanding issue where the excess experimentally
measured interfacial carrier density is significantly lower than theoretically
predicted values.The charge-phonon induced lattice distortion further provides
an analogue to the superconductive states in magic-angle twisted bilayer
graphene attributed to the many-body correlations induced by broken periodic
lattice symmetry.Our study sheds light on the multifaceted complexity of broken
periodic lattice induced quasi-particle effects and its relationship with
superconductivity
Minimum light number of lit-only σ-game on a tree. Theoretical Computer Science 381
Abstract Let T be a tree with leaves. Each vertex of T is assigned a state either lit or off. An assignment of states to all the vertices of T is called a configuration. The lit-only σ -game allows the player to pick a lit vertex and change the states of all its neighbours. We prove that for any initial configuration one can make a sequence of allowable moves to arrive at a configuration in which the number of lit vertices is no greater than 2 . We also give examples to show that the bound 2 cannot be relaxed to 2
LH-21, A Peripheral Cannabinoid Receptor 1 Antagonist, Exerts Favorable Metabolic Modulation Including Antihypertensive Effect in KKAy Mice by Regulating Inflammatory Cytokines and Adipokines on Adipose Tissue
Patients with obesity are susceptible to hypertension and diabetes. Over-activation of cannabinoid receptor 1 (CB1R) in adipose tissue is proposed in the pathophysiology of metabolic disorders, which led to the metabolic dysfunction of adipose tissue and deregulated production and secretion of adipokines. In the current study, we determined the impact of LH-21, a representative peripheral CB1R antagonist, on the obesity-accompanied hypertension and explored the modulatory action of LH-21 on the adipose tissue in genetically obese and diabetic KKAy mice. 3-week LH-21 treatment significantly decreased blood pressure with a concomitant reduction in body weight, white adipose tissue (WAT) mass, and a slight loss on food intake in KKAy mice. Meanwhile, glucose handling and dyslipidemia were also markedly ameliorated after treatment. Gene expression of pro-inflammatory cytokines in WAT and the aortae were both attenuated apparently by LH-21, as well the mRNA expression of adipokines (lipocalin-2, leptin) in WAT. Concomitant amelioration on the accumulation of lipocalin-2 was observed in both WAT and aortae. In corresponding with this, serum inflammatory related cytokines (tumor necrosis factor α, IL-6, and CXCL1), and lipocalin-2 and leptin were lowered notably. Thus according to current results, it can be concluded that the peripheral CB1R antagonist LH-21 is effective in managing the obesity-accompanied hypertension in KKAy mice. These metabolic benefits are closely associated with the regulation on the production and secretion of inflammatory cytokines and adipokines in the WAT, particularly alleviated circulating lipocalin-2 and its accumulation in aortae