737 research outputs found
Stability of Spinmotive Force in Perpendicularly Magnetized Nanowires under High Magnetic Fields
Spinmotive force induced by domain wall motion in perpendicularly magnetized
nanowires is numerically demonstrated. We show that using nanowires with large
magnetic anisotropy can lead to a high stability of spinmotive force under
strong magnetic fields. We observe spinmotive force in the order of tens of
microvolt in a multilayered Co/Ni nanowire and in the order of several hundred
microvolt in a FePt nanowire; the latter is two orders of magnitude greater
than that in permalloy nanowires reported previously. The narrow structure and
low mobility of a domain wall under magnetic fields in perpendicularly
magnetized nanowires permits downsizing of spinmotive force devices.Comment: submitted to Applied Physics Letter
Effects of mechanical rotation on spin currents
We study the Pauli--Schr\"odinger equation in a uniformly rotating frame of
reference to describe a coupling of spins and mechanical rotations. The
explicit form of the spin-orbit interaction (SOI) with the inertial effects due
to the mechanical rotation is presented. We derive equations of motion for a
wavepacket of electrons in two-dimensional planes subject to the SOI. The
solution is a superposition of two cyclotron motions with different frequencies
and a circular spin current is created by the mechanical rotation.Comment: 4 pages, 2 figure
Revisiting substorm events with preonset aurora
Nishimura et al. (2010) proposed a new plasma intrusion or preonset aurora
scenario of substorm triggering. In this scenario, a substorm is triggered by
a fast earthward flow generated at the distant neutral line which corresponds
to a preonset auroral streamer or arc in the ionosphere propagating from the
auroral poleward boundary to the initial auroral brightening site, i.e.,
preonset aurora. In the present paper, we revisited three substorm events
reported as being triggered by such a mechanism related to preonset auroras,
based on THEMIS ground-based all-sky imager data. Unlike previous studies, we
examined the arrival timing of the preonset aurora relative to the three
steps of auroral onset arc development (initial brightening, enhancement of
the wave-like structure, and poleward expansion) to make the role of the
preonset aurora in the auroral steps clearer. Our detailed timing analysis
found that preonset auroral streamers reached the auroral onset arc but away
from the initial brightening site after initial brightening for two events,
while no preonset aurora reaching the initial brightening site could be
identified for the other event. This result suggests that the processes
associated with auroral streamers are unlikely to affect at least initial
brightening, even if we consider not only the presence and arrival timing and
location of the auroral streamers but also the scale of the corresponding
flow and flow vortices. We list a series of open questions for testing the
preonset aurora scenario further in future studies.</p
Multicomponent Bright Solitons in F = 2 Spinor Bose-Einstein Condensates
We study soliton solutions for the Gross--Pitaevskii equation of the spinor
Bose--Einstein condensates with hyperfine spin F=2 in one-dimension. Analyses
are made in two ways: by assuming single-mode amplitudes and by generalizing
Hirota's direct method for multi-components. We obtain one-solitons of
single-peak type in the ferromagnetic, polar and cyclic states, respectively.
Moreover, twin-peak type solitons both in the ferromagnetic and the polar state
are found.Comment: 15 pages, 8 figure
O espectro das falências ovarianas ligadas ao cromossomo X
Clinically ovarian failure is presented by primary or secondary amenorrhea and high levels of pituitary gonadotropins mainly FSH. Monossomy or X-chromosome rearrangements are among a variable number of suggested etiopathogenic factors of ovarian failure in young women. Besides in Turner syndrome (X-monossomy or mosaicism), where the short stature and sexual infantilism point to the diagnosis, X-chromosome long arm (Xq) rearrangements, or genetic mutations of genes mapped at this segment are related with ovarian failure presented in prepubertal girls and in young women without other clinical signal. The present revision focuses these chromosomal abnormalities, some of them disclosed by conventional cytogenetic methods and other only disclosed by means of molecular biological toolsA falência ovariana manifesta-se clinicamente por amenorréia primária ou secundária, e do ponto de vista hormonal caracteriza-se pelos níveis elevados de gonadotrofinas hipofisárias, principalmente FSH, cuja etiologia pode ser atribuída a varias causas, como redução numérica ou rearranjos do cromossomo X, entre outras. Além da síndrome de Turner (monossomia do cromossomo X, com ou sem mosaicismo cromossômico), cujo principal estigma - a baixa estatura - e o infantilismo sexual apontam o diagnóstico, rearranjos do braço longo de X (Xq), ou mutações instaladas em genes mapeados neste cromossomo estão relacionados com a falência ovariana em meninas pré-púberes e em mulheres adultas jovens, sem outros sinais clínicos. Neste cromossomo, nos segmentos da falência ovariana precoce (FOP1 e FOP2) situam-se genes já relacionados à insuficiência ovariana de instalação precoce. Esta revisão trata destas alterações, algumas detectadas pelas técnicas citogenéticas convencionais, outras somente por meio de recursos de biologia molecularUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Disciplina de Endocrinologia e MetabologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de GinecologiaUNIFESP, EPM, Disciplina de Endocrinologia e MetabologiaUNIFESP, EPM, Depto. de GinecologiaSciEL
Effect of the FACs distribution on the middle and low latitude ionospheric current patterns deduced by a 2-D ionospheric potential solver (GEMSIS-POT)
第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月15日(火) 国立極地研究所 2階大会議室前フロ
Pressure-driven instability in auroral images to create auroral patches
第3回極域科学シンポジウム/第36回極域宙空圏シンポジウム 11月27日(火) 国立極地研究所 2階大会議
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Assessment of inter-examiner agreement and variability in the manual classification of auditory brainstem response
Abstract
Background: The analysis of the Auditory Brainstem Response (ABR) is of
fundamental importance to the investigation of the auditory system behaviour,
though its interpretation has a subjective nature because of the manual process
employed in its study and the clinical experience required for its analysis. When
analysing the ABR, clinicians are often interested in the identification of ABR signal
components referred to as Jewett waves. In particular, the detection and study of
the time when these waves occur (i.e., the wave latency) is a practical tool for the
diagnosis of disorders affecting the auditory system. Significant differences in
inter-examiner results may lead to completely distinct clinical interpretations of the
state of the auditory system. In this context, the aim of this research was to evaluate
the inter-examiner agreement and variability in the manual classification of ABR.
Methods: A total of 160 ABR data samples were collected, for four different stimulus
intensity (80dBHL, 60dBHL, 40dBHL and 20dBHL), from 10 normal-hearing subjects
(5 men and 5 women, from 20 to 52 years). Four examiners with expertise in the
manual classification of ABR components participated in the study. The Bland-Altman
statistical method was employed for the assessment of inter-examiner agreement
and variability. The mean, standard deviation and error for the bias, which is the
difference between examiners’ annotations, were estimated for each pair of
examiners. Scatter plots and histograms were employed for data visualization and
analysis.
Results: In most comparisons the differences between examiner’s annotations were
below 0.1 ms, which is clinically acceptable. In four cases, it was found a large error
and standard deviation (>0.1 ms) that indicate the presence of outliers and thus,
discrepancies between examiners.
Conclusions: Our results quantify the inter-examiner agreement and variability of
the manual analysis of ABR data, and they also allows for the determination of
different patterns of manual ABR analysis
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