14,712 research outputs found
Anisotropic strains and magnetoresistance of La_{0.7}Ca_{0.3}MnO_{3}
Thin films of perovskite manganite La_{0.7}Ca_{0.3}MnO_{3} were grown
epitaxially on SrTiO_3(100), MgO(100) and LaAlO_3(100) substrates by the pulsed
laser deposition method. Microscopic structures of these thin film samples as
well as a bulk sample were fully determined by x-ray diffraction measurements.
The unit cells of the three films have different shapes, i.e., contracted
tetragonal, cubic, and elongated tetragonal for SrTiO_3, MgO, and LaAlO_3
cases, respectively, while the unit cell of the bulk is cubic. It is found that
the samples with cubic unit cell show smaller peak magnetoresistance than the
noncubic ones do. The present result demonstrates that the magnetoresistance of
La_{0.7}Ca_{0.3}MnO_{3} can be controlled by lattice distortion via externally
imposed strains.Comment: Revtex, 10 pages, 2 figure
CSO validator: improving manual curation workflow for biological pathways
Summary: Manual curation and validation of large-scale biological pathways are required to obtain high-quality pathway databases. In a typical curation process, model validation and model update based on appropriate feedback are repeated and requires considerable cooperation of scientists. We have developed a CSO (Cell System Ontology) validator to reduce the repetition and time during the curation process. This tool assists in quickly obtaining agreement among curators and domain experts and in providing a consistent and accurate pathway database
Two Circular-Rotational Eigenmodes in Vortex Gyrotropic Motions in Soft Magnetic Nanodots
We found, by micromagnetic numerical and analytical calculations, that the
clockwise (CW) and counterclockwise (CCW) circular-rotational motions of a
magnetic vortex core in a soft magnetic circular nanodot are the elementary
eigenmodes existing in the gyrotropic motion with respect to the corresponding
CW and CCW circular-rotational-field eigenbasis. Any steady-state vortex
gyrotropic motions driven by a linearly polarized oscillating in-plane magnetic
field in the linear regime can be perfectly understood according to the
superposition of the two circular eigenmodes, which show asymmetric resonance
characteristics reflecting the vortex polarization. The relative magnitudes in
the amplitude and phase between the CCW and CW eigenmodes determine the
elongation and orientation of the orbital trajectories of the vortex core
motions, respectively, which trajectories vary with the polarization and
chirality of the given vortex as well as the field frequency across the
resonance frequency.Comment: 30 pages, 7 figure
The nuclear envelope localization of DYT1 dystonia torsinA-ΔE requires the SUN1 LINC complex component
<p>Abstract</p> <p>Background</p> <p>DYT1 dystonia is an autosomal dominant neurological condition caused by a mutation that removes a single glutamic acid residue (ΔE) from the torsinA (torA) AAA+ protein. TorA appears to possess a nuclear envelope (NE) localized activity that requires Lamina-Associated-Polypeptide 1 (LAP1), which is an inner nuclear membrane localized torA-binding partner. Although hypoactive, the DYT1 dystonia torA-ΔE isoform often concentrates in the NE, suggesting that torA-ΔE also interacts with an NE-localized binding partner.</p> <p>Results</p> <p>We confirm that NE-localized torA-ΔE does not co-immunoprecipitate with LAP1, and find that torA-ΔE continues to concentrate in the NE of cells that lack LAP1. Instead, we find that variability in torA-ΔE localization correlates with the presence of the SUN-domain and Nesprin proteins that assemble into the LINC complex. We also find that siRNA depletion of SUN1, but not other LINC complex components, removes torA-ΔE from the NE. In contrast, the LAP1-dependent NE-accumulation of an ATP-locked torA mutant is unaffected by loss of LINC complex proteins. This SUN1 dependent torA-ΔE localization requires the torA membrane association domain, as well as a putative substrate-interaction residue, Y147, neither of which are required for torA interaction with LAP1. We also find that mutation of these motifs, or depletion of SUN1, decreases the amount of torA-WT that colocalizes with NE markers, indicating that each also underlies a normal NE-localized torA binding interaction.</p> <p>Conclusions</p> <p>These data suggest that the disease causing ΔE mutation promotes an association between torA and SUN1 that is distinct to the interaction between LAP1 and ATP-bound torA. This evidence for two NE-localized binding partners suggests that torA may act on multiple substrates and/or possesses regulatory co-factor partners. In addition, finding that the DYT1 mutation causes abnormal association with SUN1 implicates LINC complex dysfunction in DYT1 dystonia pathogenesis, and suggests a gain-of-function activity contributes to this dominantly inherited disease.</p
Interplay between carrier and impurity concentrations in annealed GaMnAs intrinsic anomalous Hall Effect
Investigating the scaling behavior of annealed GaMnAs anomalous
Hall coefficients, we note a universal crossover regime where the scaling
behavior changes from quadratic to linear, attributed to the anomalous Hall
Effect intrinsic and extrinsic origins, respectively. Furthermore, measured
anomalous Hall conductivities when properly scaled by carrier concentration
remain constant, equal to theoretically predicated values, spanning nearly a
decade in conductivity as well as over 100 K in T. Both the qualitative
and quantitative agreement confirms the validity of new equations of motion
including the Berry phase contributions as well as tunablility of the intrinsic
anomalous Hall Effect.Comment: 4 pages, 5 figure
Two semi-Lagrangian fast methods for Hamilton-Jacobi-Bellman equations
In this paper we apply the Fast Iterative Method (FIM) for solving general
Hamilton-Jacobi-Bellman (HJB) equations and we compare the results with an
accelerated version of the Fast Sweeping Method (FSM). We find that FIM can be
indeed used to solve HJB equations with no relevant modifications with respect
to the original algorithm proposed for the eikonal equation, and that it
overcomes FSM in many cases. Observing the evolution of the active list of
nodes for FIM, we recover another numerical validation of the arguments
recently discussed in [Cacace et al., SISC 36 (2014), A570-A587] about the
impossibility of creating local single-pass methods for HJB equations
Жаростойкий сорт перца демонстрирует высокие показатели хлорофилла, фотосинтеза, устьичной проводимости и транспирации в режиме теплового стресса на стадии развития плодов
Relevance. Abiotic stress, as heat, significantly affect plant and floral organs growth and development, fruit set, productivity, the quality, and survival of crops. Heat injury occurs when plants are exposed to these temperatures for a long period of time. Depending on the intensity and duration of exposure to the high temperatures, photosynthesis, respiration, membrane integrity, water relations and the hormone balance of the plants may affected.Material and methods. In this study used the commercial pepper cultivar “NW Bigarim” (HT37) released in South Korea and accessions “Kobra” (HT1) and “Samchukjaere” (HT7) selected as heat tolerant and susceptible, respectively. Total chlorophyll index and photosynthetic activities measured using a SPAD meter (Konica, Japan) and portable photosynthesis measurement system (LI-6400, LI-COR Bioscience, Lincoln, NE, USA), respectively.Results. To evaluate the positive effects of high temperature regime (40/28°C day/night, 14/10-h light/dark cycle) on the response of photosynthetic parameters in pepper plants with different heat susceptibility, we measured the total chlorophyll content (CHL) and photosynthetic activities such as photosynthesis (Pn), stomatal conductance to H2O (Gs) and transpiration rate (Tr) in a heat-tolerant (HT1) and -susceptible cultivars (HT7) in comparison with released cultivar (HT37) at fruit development stage. Heat-tolerant cultivars showed higher and more stable index of the CHL, Pn, Gs and Tr than those in heat-sensitive cultivars for 14 days of heat treatment (HT) period. However, the initial index of Pn, Gs and Tr showed significant alteration among pepper plants regardless of thermotolerance rate before HT on day 0 and day 7 after recovery at normal treatment condition (NT) except for CHL, meaning that plants response to high temperature regime is different from that in normal condition. These results suggest that constant high rates of Pn, Gs and Tr as well as of CHL in heat stress condition periods confer to avoid from heat injury during reproductive growth stages.Актуальность. Абиотический стресс, такой как высокая температура, существенно влияет на рост и развитие репродуктивных органов растений, завязываемость плодов, продуктивность, качество и выживание. При длительном воздействия высоких температур у растений наблюдаются повреждения, и в зависимости от продолжительности и интенсивности высоких температур нарушается фотосинтез, транспирация, целостность мембраны, водный и гормональный баланс.Материал и методика. В данной работе использовали районированный в Южной Корее сорт перца «NW Bigarim» (HT37), а также сортообразцы «Kobra» (HT1) и «Samchukjaere» (HT7) выделенные как устойчивый и восприимчивый к высоким температурам, соответственно. Фотосинтез и общее содержание хлорофилла в листьях определяли при помощи портативного системы (LI-6400, LI-COR Bioscience, Lincoln, NE, USA) и спадметера (Konica Japan), соответственно.Результаты. Изучено и выявлено положительное влияние высокотемпературного режима (40/28°C день/ночь, 14/10-часовой цикл свет/темнота) на реакцию фотосинтетических параметров у растений перца с различной тепловой восприимчивостью, измерено общее содержание хлорофилла (CHL) и фотосинтетической активности, таких параметров, как фотосинтез (Pn), устьичная проводимость в H2O (Gs) и скорость транспирации (Tr) у листьев термостойкого (HT1) и чувствительного сортов (HT7) в сравнении с районированным сортом (HT37) на стадии развития плода. Термостойкий сорт показал более высокие и более стабильные показатели CHL, Pn, Gs и Tr, чем термочувствительный сорт HT7 в течение 14 дней термической обработки (HT). Однако исходные показатели Pn, Gs и Tr показали значительную вариабельность среди растений перца независимо от степени термотолерантности перед обработкой высокой температурой на 0 день и на день 7 после восстановления при нормальных условиях выращивание (NT), за исключением CHL, что означает, что растения реагируют на высокотемпературный режим, отличающийся от условий роста в NT. Эти результаты предполагают, что постоянное высокое снижение Pn, Gs и Tr, а также CHL в периоды теплового стресса позволяет избежать теплового повреждения на стадиях репродуктивного роста растений
Noise temperature measurements for axion haloscope experiments at IBS/CAPP
The axion was first introduced as a consequence of the Peccei-Quinn mechanism
to solve the CP problem in strong interactions of particle physics and is a
well motivated cold dark matter candidate. This particle is expected to
interact extremely weakly with matter and its mass is expected to lie in
eV range with the corresponding frequency roughly in GHz range. In 1983 P.
Sikivie proposed a detection scheme, so called axion haloscope, where axions
resonantly convert to photons in a tunable microwave cavity permeated by a
strong magnetic field. A major source of the experimental noise is attributed
to added noise by RF amplifiers, and thus precise understandings of amplifiers'
noise is of importance. We present the measurements of noise temperatures of
various low noise amplifiers broadly used for axion dark matter searches.Comment: 7 pages, 3 figure
Cluster Model of Decagonal Tilings
A relaxed version of Gummelt's covering rules for the aperiodic decagon is
considered, which produces certain random-tiling-type structures. These
structures are precisely characterized, along with their relationships to
various other random tiling ensembles. The relaxed covering rule has a natural
realization in terms of a vertex cluster in the Penrose pentagon tiling. Using
Monte Carlo simulations, it is shown that the structures obtained by maximizing
the density of this cluster are the same as those produced by the corresponding
covering rules. The entropy density of the covering ensemble is determined
using the entropic sampling algorithm. If the model is extended by an
additional coupling between neighboring clusters, perfectly ordered structures
are obtained, like those produced by Gummelt's perfect covering rules.Comment: 10 pages, 20 figures, RevTeX; minor changes; to be published in Phys.
Rev.
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