877 research outputs found
Rad62 protein functionally and physically associates with the Smc5/Smc6 protein complex and is required for chromosome integrity and recombination repair in fission yeast
Smc5 and Smc6 proteins form a heterodimeric SMC (structural maintenance of chromosome) protein complex like SMC1-SMC3 cohesin and SMC2-SMC4 condensin, and they associate with non-SMC proteins Nse1 and Nse2 stably and Rad60 transiently. This multiprotein complex plays an essential role in maintaining chromosome integrity and repairing DNA double strand breaks (DSBs). This study characterizes a Schizosaccharomyces pombe mutant rad62-1, which is hypersensitive to methyl methanesulfonate (MMS) and synthetically lethal with rad2 (a feature of recombination mutants). rad62-1 is hypersensitive to UV and gamma rays, epistatic with rhp51, and defective in repair of DSBs. rad62 is essential for viability and genetically interacts with rad60, smc6, and brc1. Rad62 protein physically associates with the Smc5-6 complex. rad62-1 is synthetically lethal with mutations in the genes promoting recovery from stalled replication, such as rqh1, srs2, and mus81, and those involved in nucleotide excision repair like rad13 and rad16. These results suggest that Rad62, like Rad60, in conjunction with the Smc5-6 complex, plays an essential role in maintaining chromosome integrity and recovery from stalled replication by recombination
Two‐Dimensional Local Modeling of Thermospheric Heating and Neutral Mass Density Enhancement Driven by Alfvén Waves
In the cusp region, a significantly enhanced thermospheric mass density is commonly observed around 400 km altitude. Despite a number of studies, the enhancement mechanism has not been fully characterized. In order to determine how the Joule heating and resultant mass density enhancements are generated in the region of the ionosphere during a few hours after the Alfvén resonator modes are set up, we have developed a new efficient method to calculate Alfvén waves. In this method, the Fourier transform was used, and Alfvén waves were solved as frequency-domain boundary value problems. We employed a two-dimensional local model and performed five modeling runs. The result from the modeling runs shows that the Alfvén resonator modes generate significant neutral upwelling at ∼300 km altitude, which creates a “cell” of the neutral mass density enhancement at altitudes centered between 350 and 400 km. This cell becomes evident roughly 1 hr after the Alfvén resonator modes are set up, and this region continues to exist stably for 2 more hours. A fractional mass density enhancement at 400 km altitude 3 hr after the Alfvén resonator modes having an Alfvénic field-aligned current of 20 μAm⁻² at the top boundary are set up reaches ∼30%, which is consistent with the result obtained from satellite observations. In terms of the Poynting flux, this corresponds to ∼20 mWm⁻², which is also consistent with previous satellite observations
NMR evidence for very slow carrier density fluctuations in the organic metal (TMTSF)ClO
We have investigated the origin of the large increase in spin-echo decay
rates for the Se nuclear spins at temperatures near to in the
organic superconductor (TMTSF)ClO. The measured angular dependence of
demonstrates that the source of the spin-echo decays lies with
carrier density fluctuations rather than fluctuations in TMTSF molecular
orientation. The very long time scales are directly associated with the
dynamics of the anion ordering occurring at , and the inhomogeneously
broadened spectra at lower temperatures result from finite domain sizes. Our
results are similar to observations of line-broadening effects associated with
charge-ordering transitions in quasi-two dimensional organic conductors.Comment: 5 pages, 4 figure
Towards a consistent picture for quasi-1D organic superconductors
The electrical resistivity of the quasi-1D organic superconductor (TMTSF)2PF6
was recently measured at low temperature from the critical pressure needed to
suppress the spin-density-wave state up to a pressure where superconductivity
has almost disappeared. This data revealed a direct correlation between the
onset of superconductivity at Tc and the strength of a non-Fermi-liquid linear
term in the normal-state resistivity, going as r(T) = r0 + AT + BT2 at low
temperature, so that A goes to 0 as Tc goes to 0. Here we show that the
contribution of low-frequency antiferromagnetic fluctuations to the
spin-lattice relaxation rate is also correlated with this non-Fermi-liquid term
AT in the resistivity. These correlations suggest that anomalous scattering and
pairing have a common origin, both rooted in the low-frequency
antiferromagnetic fluctuations measured by NMR. A similar situation may also
prevail in the recently-discovered iron-pnictide superconductors.Comment: ISCOM'09 proceedings to be published in Physica
Extending the linearity range of eddy-current displacement sensor with magnetoplated wire
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.ArticleIEEE TRANSACTIONS ON MAGNETICS. 43(2): 543-548 (2007)journal articl
Reduction of eddy current loss in magnetoplated wire
ArticleCOMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING. 28(1):57-66 (2009)journal articl
Reduction of proximity effect in coil using magnetoplated wire
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.ArticleIEEE TRANSACTIONS ON MAGNETICS. 43(6): 2654-2656 (2007)journal articl
Extreme ion heating in the dayside ionosphere in response to the arrival of a coronal mass ejection on 12 March 2012
Simultaneous measurements of the polar ionosphere with the European Incoherent Scatter (EISCAT) ultra high frequency (UHF) radar
at Tromsø and the EISCAT Svalbard radar (ESR) at Longyearbyen were made
during 07:00–12:00 UT on 12 March 2012. During the period, the Advanced Composition Explorer (ACE) spacecraft
observed changes in the solar wind which were due to the arrival of
coronal mass ejection (CME) effects associated with the 10 March M8.4 X-ray
event. The solar wind showed two-step variations which caused strong
ionospheric heating. First, the arrival of shock structures in the solar wind
with enhancements of density and velocity, and a negative interplanetary magnetic field (IMF)-<i>B<sub>z</sub></i> component
caused strong ionospheric heating around Longyearbyen; the ion temperature at
about 300 km increased from about 1100 to 3400 K over Longyearbyen while
that over Tromsø increased from about 1050 to 1200 K. After the passage
of the shock structures, the IMF-<i>B<sub>z</sub></i> component showed positive values and
the solar wind speed and density also decreased. The second strong
ionospheric heating occurred after the IMF-<i>B<sub>z</sub></i> component showed
negative values again; the negative values lasted for more than
1.5 h. This solar wind variation caused stronger heating of the ionosphere in
the lower latitudes than higher latitudes, suggesting expansion of the auroral
oval/heating region to the lower latitude region. This study shows an example
of the CME-induced dayside ionospheric heating: a short-duration and very large rise in the ion temperature which was closely related to the polar
cap size and polar cap potential variations as a result of interaction
between the solar wind and the magnetosphere
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