2,165 research outputs found
Dependence of quantum-Hall conductance on the edge-state equilibration position in a bipolar graphene sheet
By using four-terminal configurations, we investigated the dependence of
longitudinal and diagonal resistances of a graphene p-n interface on the
quantum-Hall edge-state equilibration position. The resistance of a p-n device
in our four-terminal scheme is asymmetric with respect to the zero point where
the filling factor () of the entire graphene vanishes. This resistance
asymmetry is caused by the chiral-direction-dependent change of the
equilibration position and leads to a deeper insight into the equilibration
process of the quantum-Hall edge states in a bipolar graphene system.Comment: 5 pages, 4 figures, will be published in PR
Thermoelectric Transport of Massive Dirac Fermions in Bilayer Graphene
Thermoelectric power (TEP) is measured in bilayer graphene for various
temperatures and charge-carrier densities. At low temperatures, measured TEP
well follows the semiclassical Mott formula with a hyperbolic dispersion
relation. TEP for a high carrier density shows a linear temperature dependence,
which demonstrates a weak electron-phonon interaction in the bilayer graphene.
For a low carrier density, a deviation from the Mott relation is observed at
high temperatures and is attributed to the low Fermi temperature in the bilayer
graphene. Oscillating TEP and the Nernst effect for varying carrier density,
observed in a high magnetic field, are qualitatively explained by the two
dimensionality of the system.Comment: published versio
The voltage-gated potassium channel Shaker promotes sleep via thermosensitive GABA transmission
Genes and neural circuits coordinately regulate animal sleep. However, it remains elusive how these endogenous factors shape sleep upon environmental changes. Here, we demonstrate that Shaker (Sh)-expressing GABAergic neurons projecting onto dorsal fan-shaped body (dFSB) regulate temperature-adaptive sleep behaviors in Drosophila. Loss of Sh function suppressed sleep at low temperature whereas light and high temperature cooperatively gated Sh effects on sleep. Sh depletion in GABAergic neurons partially phenocopied Sh mutants. Furthermore, the ionotropic GABA receptor, Resistant to dieldrin (Rdl), in dFSB neurons acted downstream of Sh and antagonized its sleep-promoting effects. In fact, Rdl inhibited the intracellular cAMP signaling of constitutively active dopaminergic synapses onto dFSB at low temperature. High temperature silenced GABAergic synapses onto dFSB, thereby potentiating the wake-promoting dopamine transmission. We propose that temperature-dependent switching between these two synaptic transmission modalities may adaptively tune the neural property of dFSB neurons to temperature shifts and reorganize sleep architecture for animal fitness.
Ji-hyung Kim and Yoonhee Ki et al. show that low temperatures suppress sleep in Drosophila by increasing GABA transmission in Shaker-expressing GABAergic neurons projecting onto the dorsal fan-shaped body, while high temperatures potentiate dopamine-induced arousal by reducing GABA transmission. This study highlights a role for Shaker in sleep modulation via a temperature-dependent switch in GABA signaling
Comparison of longitudinal treatment effects with facemask and chincup therapy followed by fixed orthodontic treatment on Class III malocclusion
Objective: The purpose of this study was to compare the longitudinal treatment effects of facemask with
rapid maxillary expansion (FM/RME) and chincup (CC) therapy followed by fixed orthodontic treatment
(FOT) in Class III malocclusion (CIII) patients. Methods: The samples consisted of twenty-one CIII patients
who had similar skeletal and dental characteristics before FM/RME or CC therapy and good retention results
(Class I molar/canine relationship and positive overbite/overjet) after FOT (Group 1, FM/RME, n =
11; Group 2, CC, n = 10). Lateral cephalograms were taken before (T0) and after FM/RME or CC therapy
(T1), and after FOT and retention (T2). Skeletal and dental variables were measured. Mann-Whitney U-test
and Wilcoxon signed-rank test were used for statistical analysis. Results: During T0-T1, FM/RME therapy
induced forward movement of point A, and labioversion of the upper incisors. Both groups showed posterior
repositioning of the mandible. FM/RME resulted in increase of the vertical dimension; however, CC caused
an increase in articular angle and decrease in gonial angle. During T1-T2, both groups exhibited forward
growth of point A. Group 1 showed forward growth and counterclockwise rotation of the mandible and increase
of IMPA; however, Group 2, showed increase of ANS-Me/N-Me and decrease of overbite.
Conclusions: The key factor for successful FM/RME and CC therapy and good retention results might be
a harmonized forward growth of the maxilla that could keep pace with the growth and rotation of the
mandible
Variation in leaf functional traits of the Korean maple (Acer pseudosieboldianum) along an elevational gradient in a montane forest in Southern Korea
Plant functional traits have been shown to be useful to understand how and why ecosystems and their components vary across environmental heterogeneity or gradients. This study investigated how plant functional (leaf) traits vary according to an elevation-associated environmental gradient. Environmental gradients (mean annual temperature and precipitation) were quantified, and leaf traits (leaf area, specific leaf area, leaf nitrogen, leaf phosphorus, leaf carbon, and leaf C/N ratio) of the understory woody plant species Acer pseudosieboldianum were examined across an elevational gradient ranging from 600 to 1200 m in a Baegunsan Mountain in Gwangyang-si, Jeollanam-do, South Korea. The results showed that mean annual temperature and precipitation decreased and increased along with elevation, respectively. Leaf area of the plant species decreased slightly with increasing elevation, while specific leaf area did not differ significantly. Leaf nutrients (nitrogen, phosphorus, and carbon concentrations) were higher at high elevations, but leaf C/N ratio decreased with elevation.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2015R1C1A1A01053841), (2017-0994)
Leukoaraiosis is associated with pneumonia after acute ischemic stroke
Diagnostic criteria for stroke associated pneumonia based on the CDC criteria. (DOCX 25 kb
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