SU(m) non-Abelian anyons in the Jain hierarchy of quantum Hall states

We show that different classes of topological order can be distinguished by the dynamical symmetry algebra of edge excitations. Fundamental topological order is realized when this algebra is the largest possible, the algebra of quantum area-preserving diffeomorphisms, called $W_{1+\infty}$. We argue that this order is realized in the Jain hierarchy of fractional quantum Hall states and show that it is more robust than the standard Abelian Chern-Simons order since it has a lower entanglement entropy due to the non-Abelian character of the quasi-particle anyon excitations. These behave as SU($m$) quarks, where $m$ is the number of components in the hierarchy. We propose the topological entanglement entropy as the experimental measure to detect the existence of these quantum Hall quarks. Non-Abelian anyons in the $\nu = 2/5$ fractional quantum Hall states could be the primary candidates to realize qbits for topological quantum computation.Comment: 5 pages, no figures, a few typos corrected, a reference adde

Fever, febrile seizures and epilepsy.

Seizures induced by fever (febrile seizures) are the most common type of pathological brain activity in infants and children. These febrile seizures and their potential contribution to the mechanisms of limbic (temporal lobe) epilepsy have been a topic of major clinical and scientific interest. Key questions include the mechanisms by which fever generates seizures, the effects of long febrile seizures on neuronal function and the potential contribution of these seizures to epilepsy. This review builds on recent advances derived from animal models and summarizes our current knowledge of the mechanisms underlying febrile seizures and of changes in neuronal gene expression and function that facilitate the enduring effects of prolonged febrile seizures on neuronal and network excitability. The review also discusses the relevance of these findings to the general mechanisms of epileptogenesis during development and points out gaps in our knowledge, including the relationship of animal models to human febrile seizures and epilepsy

The Transmuted Exponentiated Additive Weibull Distribution: Properties and Applications

A new generalization of the transmuted additive Weibull distribution is proposed by using the quadratic rank transmutation map, the so-called transmuted exponentiated additive Weibull distribution. It retains the characteristics of a good model. It is more flexible, being able to analyze more complex data; it includes twenty-seven sub-models as special cases and it is interpretable. Several mathematical properties of the new distribution as closed forms for ordinary and incomplete moments, quantiles, and moment generating function are presented, as well as the MLEs. The usefulness of the model is illustrated by using two real data sets

Remarks on the tight-binding model of graphene

We address a simple but fundamental issue arising in the study of graphene, as well as of other systems that have a crystalline structure with more than one atom per unit cell. For these systems, the choice of the tight-binding basis is not unique. For monolayer graphene two bases are widely used in the literature. While the expectation values of operators describing physical quantities should be independent of basis, the form of the operators may depend on the basis, especially in the presence of disorder or of an applied magnetic field. Using the inappropriate form of certain operators may lead to erroneous physical predictions. We discuss the two bases used to describe monolayer graphene, as well as the form of the most commonly used operators in the two bases. We repeat our analysis for the case of bilayer graphene.Comment: 15 pages, 4 figure

A blade for all seasons? Making and using Amudian blades at Qesem Cave, Israel

The Qesem Cave prehistoric sequence consists of one dominant lithic industry - the Amudian, a part of the Acheulo-Yabrudian (late Lower Paleolithic) cultural complex. The Acheulo-Yabrudian complex comprises three major lithic industries - Acheulo-Yabrudian, Yabrudian and Pre-Aurignacian/Amudian. While the first two industries are dominated by typical Lower Paleolithic lithic traditions, namely flake production technologies, hand-axes and scrapers, the Amudian presents an innovative blade industry. This relatively poorly known industry is of importance being stratigraphically situated between the Lower Paleolithic Acheulian and the Middle Paleolithic Mousterian. The available radiometric dates for this entity indicate a range from ca. 400 to about 200 kyr. The Amudian in the Levant is characterized by systematic blade production and a major component of shaped blades. At Qesem Cave the majority of the lithic artefacts belong to the Amudian industry with distinctive blade-dominated assemblages throughout a stratigraphic sequence of 7.5 meters. During the 2006 excavation season a scraper-dominated Yabrudian assemblage was discovered, indicating variability and more complex human behaviour at the cave rather than specialized blade-related activities only. The Amudian at Qesem Cave is a very early blade production industry and it reflects technological choices of the artisans as well as specific modes of resource exploitation and subsistence activities. This paper will summarize the current state of research on the Qesem cave lithic assemblages, focusing on the composition of the rich Amudian assemblages, the reconstruction of Amudian blade production and the functional interpretation of Amudian blades. A short survey of the new Yabrudian assemblage will be provided as well. We finally discuss interpretations of Acheulo-Yabrudian lithic variability and the meaning of late Lower Paleolithic blade production as a technological, functional and cultural phenomenon.The Qesem Cave prehistoric sequence consists of one dominant lithic industry - the Amudian, a part of the Acheulo-Yabrudian (late Lower Paleolithic) cultural complex. The Acheulo-Yabrudian complex comprises three major lithic industries - Acheulo-Yabrudian, Yabrudian and Pre-Aurignacian/Amudian. While the first two industries are dominated by typical Lower Paleolithic lithic traditions, namely flake production technologies, hand-axes and scrapers, the Amudian presents an innovative blade industry. This relatively poorly known industry is of importance being stratigraphically situated between the Lower Paleolithic Acheulian and the Middle Paleolithic Mousterian. The available radiometric dates for this entity indicate a range from ca. 400 to about 200 kyr. The Amudian in the Levant is characterized by systematic blade production and a major component of shaped blades. At Qesem Cave the majority of the lithic artefacts belong to the Amudian industry with distinctive blade-dominated assemblages throughout a stratigraphic sequence of 7.5 meters. During the 2006 excavation season a scraper-dominated Yabrudian assemblage was discovered, indicating variability and more complex human behaviour at the cave rather than specialized blade-related activities only. The Amudian at Qesem Cave is a very early blade production industry and it reflects technological choices of the artisans as well as specific modes of resource exploitation and subsistence activities

Reduced caveolae density in arteries of SHR contributes to endothelial dysfunction and ROS production

Caveolae are plasma membrane invaginations enriched with high cholesterol and sphingolipid content; they also contain caveolin proteins in their structure. Endothelial nitric oxide synthase (eNOS), an enzyme that synthesizes nitric oxide (NO) by converting L-arginine to L-citrulline, is highly concentrated in plasma membrane caveolae. Hypertension is associated with decreased NO production and impaired endothelium-dependent relaxation. Understanding the molecular mechanisms that follow hypertension is important. For this study, we hypothesized that spontaneously hypertensive rat (SHR) vessels should have a smaller number of caveolae, and that the caveolae structure should be disrupted in these vessels. This should impair the eNOS function and diminish NO bioavailability. Therefore, we aimed to investigate caveolae integrity and density in SHR aortas and mesenteric arteries and the role played by caveolae in endothelium-dependent relaxation. We have been able to show the presence of caveolae-like structures in SHR aortas and mesenteric arteries. Increased phenylephrine-induced contractile response after treatment with dextrin was related to lower NO release. In addition, impaired acetylcholine-induced endothelium-dependent relaxation could be related to decreased caveolae density in SHR vessels. The most important finding of this study was that cholesterol depletion with dextrin induced eNOS phosphorylation at Serine1177 (Ser1177) and boosted reactive oxygen species (ROS) production in normotensive rat and SHR vessels, which suggested eNOS uncoupling. Dextrin plus L-NAME or BH4 decreased ROS production in aorta and mesenteric arteries supernatant's of both SHR and normotensive groups. Human umbilical vein endothelial cells (HUVECs) treated with dextrin confirmed eNOS uncoupling, as verified by the reduced eNOS dimer/monomer ratio. BH4, L-arginine, or BH4 plus L-arginine inhibited eNOS monomerization. All these results showed that caveolae structure and integrity are essential for endothelium-dependent relaxation. Additionally, a smaller number of caveolae is associated with hypertension. Finally, caveolae disruption promotes eNOS uncoupling in normotensive and hypertensive rat vessels and in HUVECs.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2016/22180-9, 2016/21239-0, 2017/14797-9]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [400.164/2014-0, 304.137/2014-6]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Water use in Citrus: effect on porosity in water retention in a “Latossolo vermelho-escuro” of Northeast of Estado de Sao Paulo

[Abstract] The objective of this research was to study the porosity, bulk density and retention of water of an Oxisol, located in the Northwestern region of São Paulo state, Brazil. The soil was cultivated with Citrus sp., to which green manure was applied between rows for three years. Each of six species of green manure crops (Crotalaria junceaL., Mucunade eringian a Steph. & Bart., Canavalia ensiformis L. DC., Cajanus cajan L., Lablab purpureum L. and Ricinus communis L.) were seeded for three years (1995, 1996 and 1997) between Citrus rows, plus a treatment with a mix of all six species and a control (natural regrowth af vegetation). The experimental design was a randomized complete block design, with four replications for each of the eight treatments. Water retention, microporosity, macroporosity, total porosity and bulk density were analyzed in the beginning (1995) and end (1997) of the experiment, at three depth ranges (0-0.10; 0.10-0.20 and 0.20-0.40m). We concluded that there were statistically significant differences for bulk density, macroporosity, total porosity and retention of water among the different soil depth ranges; there were no significant differences among treatments though

Spin Transport in a Quantum Wire

We study the effect of electron-electron backscattering interactions on spin transport in a quantum wire. Even if these interactions have no significant effect on charge transport, they strongly influence the transport of spin. We use the quantum Boltzmann equation in the collision approximation to derive equations of motion for spin current and magnetization. In the limit of small perturbations from equilibrium, we explain the existence of `precessional' and `diffusive' behaviors. We also discuss the low-temperature non-linear decay of an uniform spin current outside the hydrodynamic regime.Comment: 10 pages, 5 figures, REVTE