189 research outputs found
Using Provenance to support Good Laboratory Practice in Grid Environments
Conducting experiments and documenting results is daily business of
scientists. Good and traceable documentation enables other scientists to
confirm procedures and results for increased credibility. Documentation and
scientific conduct are regulated and termed as "good laboratory practice."
Laboratory notebooks are used to record each step in conducting an experiment
and processing data. Originally, these notebooks were paper based. Due to
computerised research systems, acquired data became more elaborate, thus
increasing the need for electronic notebooks with data storage, computational
features and reliable electronic documentation. As a new approach to this, a
scientific data management system (DataFinder) is enhanced with features for
traceable documentation. Provenance recording is used to meet requirements of
traceability, and this information can later be queried for further analysis.
DataFinder has further important features for scientific documentation: It
employs a heterogeneous and distributed data storage concept. This enables
access to different types of data storage systems (e. g. Grid data
infrastructure, file servers). In this chapter we describe a number of building
blocks that are available or close to finished development. These components
are intended for assembling an electronic laboratory notebook for use in Grid
environments, while retaining maximal flexibility on usage scenarios as well as
maximal compatibility overlap towards each other. Through the usage of such a
system, provenance can successfully be used to trace the scientific workflow of
preparation, execution, evaluation, interpretation and archiving of research
data. The reliability of research results increases and the research process
remains transparent to remote research partners.Comment: Book Chapter for "Data Provenance and Data Management for eScience,"
of Studies in Computational Intelligence series, Springer. 25 pages, 8
figure
К вопросу о визуализации травматичного и деструктивного опыта в европейском искусстве
На основании разведения понятий травматичного и деструктивного опытов производится анализ конкретных произведений искусства. Акцент сделан на соотношении художественного образа и художественных приемов с процессом разрушения традиционного, классического мировосприятия, основанного на центрировании метафизических категорий. Полагается, что европейское искусство, вплоть до второй половины ХХ в., в большей степени было ориентировано на визуализацию деструктивного культурного опыта; современное искусство сосредотачивается на травматичном опыте
The Magnetic Gr\"uneisen Parameter for Model Systems
The magneto-caloric effect (MCE), which is the refrigeration based on the
variation of the magnetic entropy, is of great interest in both technological
applications and fundamental research. The MCE is quantified by the magnetic
Gr\"uneisen parameter . We report on an analysis of
for the classical Brillouin-like paramagnet, for a
modified Brillouin function taking into account a zero-field splitting
originated from the spin-orbit (SO) interaction and for the one-dimensional
Ising (1DI) model under longitudinal field. For both Brillouin-like model with
SO interaction and the longitudinal 1DI model, for 0 and
vanishing field a sign change of the MCE is observed, suggestive of a quantum
phase transition. SO interaction leads to a narrowing of the critical
fluctuations upon approaching the critical point. Our findings emphasize the
relevance of for exploring critical points. Also, we
show that the Brillouin model with and without SO interaction can be recovered
from the 1DI model in the regime of high-temperatures and vanishing coupling
constant .Comment: 10 pages, 12 figures, comments are welcom
Direct visualization of dynamic magnetic coupling in a Co/Py bilayer with picosecond and nanometer resolution
We present a combination of ferromagnetic resonance (FMR) with spatially and
time-resolved X-ray absorption spectroscopy in a scanning transmission X-ray
microscope (STXM-FMR). The transverse high frequency component of the
resonantly excited magnetization is measured with element-specifity in a
Permalloy (Py) disk - Cobalt (Co) stripe bilayer microstructure. STXM-FMR
mappings are snapshots of the local magnetization-precession with nm spatial
resolution and ps temporal resolution. We directly observe the transfer of
angular momentum from Py to Co and vice versa at their respective
element-specific resonances. A third resonance could be observed in our
experiments, which is identified as a coupled resonance of Py and Co.Comment: Version submitted to Physical Review Applied with updated author list
and supplemental information (Ancillary file
Microwave soft x-ray microscopy for nanoscale magnetization dynamics in the 5-10 GHz frequency range
We present a scanning transmission x-ray microscopy setup combined with a
novel microwave synchronization scheme in order to study high frequency
magnetization dynamics at synchrotron light sources. The sensitivity necessary
to detect small changes of the magnetization on short time scales and nanometer
spatial dimensions is achieved by combination of the developed excitation
mechanism with a single photon counting electronics that is locked to the
synchrotron operation frequency. The required mechanical stability is achieved
by a compact design of the microscope. Our instrument is capable of creating
direct images of dynamical phenomena in the 5-10 GHz range, with 35 nm
resolution. When used together with circularly polarized x-rays, the above
capabilities can be combined to study magnetic phenomena at microwave
frequencies, such as ferromagnetic resonance (FMR) and spin waves. We
demonstrate the capabilities of our technique by presenting phase resolved
images of a 6 GHz nanoscale spin wave generated by a spin torque oscillator, as
well as the uniform ferromagnetic precession with ~0.1 deg amplitude at 9 GHz
in a micrometer-sized cobalt strip.Comment: 9 pages, 7 figure
Spin Pumping from Permalloy into Uncompensated Antiferromagnetic Co doped Zinc Oxide
Heterostructures of Co-doped ZnO and Permalloy were investigated for their
static and dynamic magnetic interaction. The highly Co-doped ZnO is
paramagentic at room temperature and becomes an uncompensated antiferromagnet
at low temperatures, showing a narrowly opened hysteresis and a vertical
exchange bias shift even in the absence of any ferromagnetic layer. At low
temperatures in combination with Permalloy an exchange bias is found causing a
horizontal as well as vertical shift of the hysteresis of the heterostructure
together with an increase in coercive field. Furthermore, an increase in the
Gilbert damping parameter at room temperature was found by multifrequency FMR
evidencing spin pumping. Temperature dependent FMR shows a maximum in magnetic
damping close to the magnetic phase transition. These measurements also
evidence the exchange bias interaction of Permalloy and long-range ordered
Co-O-Co structures in ZnO, that are barely detectable by SQUID due to the
shorter probing times in FMR.Comment: 9 pages, 7 figure
Irradiation Enhanced paramagnetism on graphene nanoflakes
We have studied the magnetization of vertically aligned graphene nanoflakes
irradiated with nitrogen ions of 100 KeV energy and doses in the range 10^11-
10^17 ions/cm2. The non-irradiated graphene nanoflakes show a paramagnetic
contribution, which is increased progressively by ion irradiation at low doses
up to 10^15 /cm^2. However, further increase on implantation dose reduces the
magnetic moment which coincides with the onset of amorphization as verified by
both Raman and X-ray photoelectron spectroscopic data. Overall, our results
demonstrate the absence of ferromagnetism on either implanted or unimplanted
samples from room temperature down to a temperature of 5KComment: Corresponding authors: [email protected];
[email protected]
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Genome-wide association study identifies 30 loci associated with bipolar disorder.
Bipolar disorder is a highly heritable psychiatric disorder. We performed a genome-wide association study (GWAS) including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 variants with P < 1 × 10-4 in an additional 9,412 cases and 137,760 controls. Eight of the 19 variants that were genome-wide significant (P < 5 × 10-8) in the discovery GWAS were not genome-wide significant in the combined analysis, consistent with small effect sizes and limited power but also with genetic heterogeneity. In the combined analysis, 30 loci were genome-wide significant, including 20 newly identified loci. The significant loci contain genes encoding ion channels, neurotransmitter transporters and synaptic components. Pathway analysis revealed nine significantly enriched gene sets, including regulation of insulin secretion and endocannabinoid signaling. Bipolar I disorder is strongly genetically correlated with schizophrenia, driven by psychosis, whereas bipolar II disorder is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential biological mechanisms for bipolar disorder
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