1,798 research outputs found
Towards wafer scale inductive determination of magnetostatic and dynamic parameters of magnetic thin films and multilayers
We investigate an inductive probe head suitable for non-invasive
characterization of the magnetostatic and dynamic parameters of magnetic thin
films and multilayers on the wafer scale. The probe is based on a planar
waveguide with rearward high frequency connectors that can be brought in close
contact to the wafer surface. Inductive characterization of the magnetic
material is carried out by vector network analyzer ferromagnetic resonance.
Analysis of the field dispersion of the resonance allows the determination of
key material parameters such as the saturation magnetization MS or the
effective damping parameter Meff. Three waveguide designs are tested. The
broadband frequency response is characterized and the suitability for inductive
determination of MS and Meff is compared. Integration of such probes in a wafer
prober could in the future allow wafer scale in-line testing of magnetostatic
and dynamic key material parameters of magnetic thin films and multilayers
Measurement of the analyzing power in pp elastic scattering in the peak CNI region at RHIC
We report the first measurements of the A_N absolute value and shape in the
-t range from 0.0015 to 0.010GeV/c^2 with a precision better than 0.005 for
each A_N data point using a polarized atomic hydrogen gas jet target and the
100 GeV RHIC proton beam.Comment: 4 pages, 5 figure
āCare for the common homeā : responses to Pope Francis's Encyclical Letter
Abstract: This article aims to build awareness of the growing global crisis in social, economic and environmental terms from different disciplinary approaches. The authors respond to the message of Pope Francis presented in his Encyclical Letter published in 2015. The article provides a short current overview of the discourse and presents three hypotheses anchored in the disciplines of Psychology, Health and Theology for a deeper discussion of Pope Francisās viewpoints on the challenges to humankind and how to address them. It thereby contributes to the discourse on health and religion with regard to the Popeās message to the world community. The article leads to an interdisciplinary conclusion and directions for future research and practice
First Results from MASIV: The Micro-Arcsecond Scintillation-Induced Variability Survey
We are undertaking a large-scale, Micro-Arcsecond Scintillation-Induced
Variability (MASIV) survey of the northern sky, Dec > 0 deg, at 4.9 GHz with
the VLA. Our objective is to construct a sample of 100 to 150 scintillating
extragalactic sources with which to examine both the microarcsecond structure
and the parent populations of these sources, and to probe the turbulent
interstellar medium responsible for the scintillation. We report on our first
epoch of observations which revealed variability on timescales ranging from
hours to days in 85 of 710 compact flat-spectrum sources. The number of highly
variable sources, those with RMS flux density variations greater than 4% of the
mean, increases with decreasing source flux density but rapid, large amplitude
variables such as J1819+3845 are very rare. When compared with a model for the
scintillation due to irregularities in a 500 pc thick electron layer, our
preliminary results indicate maximum brightness temperatures ~10E+12 K, similar
to those obtained from VLBI surveys even though interstellar scintillation is
not subject to the same angular resolution limit.Comment: 18 pages, 5 figures. To appear in the Astronomical Journa
The Properties of the Radio-Selected 1Jy Sample of BL Lacertae Objects
We present new optical and near-IR spectroscopy as well as new high dynamic
range, arcsecond-resolution VLA radio maps of BL Lacs from the complete
radio-selected "1 Jansky" (1Jy) sample (RBLs) for which such data were not
previously available. Unlike BL Lacs from the complete X-ray-selected Einstein
Medium Sensitivity Survey (EMSS) sample (XBLs), most RBLs possess weak but
moderately luminous emission lines. And whereas nearly all XBLs have extended
power levels consistent with FR-1s, more than half of the RBLs have extended
radio power levels too luminous to be beamed FR-1 radio galaxies. In fact, we
find evidence for and examples of three distinct mechanisms for creating the BL
Lac phenomenon in the 1Jy sample: beamed FR-1s, beamed FR-2s and possibly a few
gravitationally-lensed quasars. The v/v_max determined for the 1Jy sample is
0.614+/-0.047, which is markedly different from the negative evolution seen in
the EMSS and other XBL samples. A correlation between logarithmic X-ray to
radio flux ratio and v/v_max is observed across the EMSS and 1Jy samples, from
negative evolution in the more extreme XBLs to positive evolution in the more
extreme RBLs. There is evidence that the selection criteria chosen by Stickel
et al. eliminates some BL Lac objects from the 1Jy sample, although how many is
unknown. And several objects currently in the sample have exhibited strong
emission lines in one or more epochs, suggesting they should be reclassified as
FSRQs. However these selection effects cannot account for the observed
discrepancy in XBL and RBL properties. From these observational properties we
conclude that RBLs and XBLs cannot be related by viewing angle alone, and that
RBLs are more closely related to FSRQs.Comment: 29 pages, 47 figures, accepted A
Measuring the Polarization of a Rapidly Precessing Deuteron Beam
This paper describes a time-marking system that enables a measurement of the
in-plane (horizontal) polarization of a 0.97-GeV/c deuteron beam circulating in
the Cooler Synchrotron (COSY) at the Forschungszentrum J\"ulich. The clock time
of each polarimeter event is used to unfold the 120-kHz spin precession and
assign events to bins according to the direction of the horizontal
polarization. After accumulation for one or more seconds, the down-up
scattering asymmetry can be calculated for each direction and matched to a
sinusoidal function whose magnitude is proportional to the horizontal
polarization. This requires prior knowledge of the spin tune or polarization
precession rate. An initial estimate is refined by re-sorting the events as the
spin tune is adjusted across a narrow range and searching for the maximum
polarization magnitude. The result is biased toward polarization values that
are too large, in part because of statistical fluctuations but also because
sinusoidal fits to even random data will produce sizeable magnitudes when the
phase is left free to vary. An analysis procedure is described that matches the
time dependence of the horizontal polarization to templates based on
emittance-driven polarization loss while correcting for the positive bias. This
information will be used to study ways to extend the horizontal polarization
lifetime by correcting spin tune spread using ring sextupole fields and thereby
to support the feasibility of searching for an intrinsic electric dipole moment
using polarized beams in a storage ring. This paper is a combined effort of the
Storage Ring EDM Collaboration and the JEDI Collaboration.Comment: 28 pages, 15 figures, prepared for Physical Review ST - Accelerators
and Beam
Speaker-independent emotion recognition exploiting a psychologically-inspired binary cascade classification schema
In this paper, a psychologically-inspired binary cascade classification schema is proposed for speech emotion recognition. Performance is enhanced because commonly confused pairs of emotions are distinguishable from one another. Extracted features are related to statistics of pitch, formants, and energy contours, as well as spectrum, cepstrum, perceptual and temporal features, autocorrelation, MPEG-7 descriptors, Fujisakis model parameters, voice quality, jitter, and shimmer. Selected features are fed as input to K nearest neighborhood classifier and to support vector machines. Two kernels are tested for the latter: Linear and Gaussian radial basis function. The recently proposed speaker-independent experimental protocol is tested on the Berlin emotional speech database for each gender separately. The best emotion recognition accuracy, achieved by support vector machines with linear kernel, equals 87.7%, outperforming state-of-the-art approaches. Statistical analysis is first carried out with respect to the classifiers error rates and then to evaluate the information expressed by the classifiers confusion matrices. Ā© Springer Science+Business Media, LLC 2011
Tetraspanin (TSP-17) Protects Dopaminergic Neurons against 6-OHDA-Induced Neurodegeneration in <i>C. elegans</i>
Parkinson's disease (PD), the second most prevalent neurodegenerative disease after Alzheimer's disease, is linked to the gradual loss of dopaminergic neurons in the substantia nigra. Disease loci causing hereditary forms of PD are known, but most cases are attributable to a combination of genetic and environmental risk factors. Increased incidence of PD is associated with rural living and pesticide exposure, and dopaminergic neurodegeneration can be triggered by neurotoxins such as 6-hydroxydopamine (6-OHDA). In C. elegans, this drug is taken up by the presynaptic dopamine reuptake transporter (DAT-1) and causes selective death of the eight dopaminergic neurons of the adult hermaphrodite. Using a forward genetic approach to find genes that protect against 6-OHDA-mediated neurodegeneration, we identified tsp-17, which encodes a member of the tetraspanin family of membrane proteins. We show that TSP-17 is expressed in dopaminergic neurons and provide genetic, pharmacological and biochemical evidence that it inhibits DAT-1, thus leading to increased 6-OHDA uptake in tsp-17 loss-of-function mutants. TSP-17 also protects against toxicity conferred by excessive intracellular dopamine. We provide genetic and biochemical evidence that TSP-17 acts partly via the DOP-2 dopamine receptor to negatively regulate DAT-1. tsp-17 mutants also have subtle behavioral phenotypes, some of which are conferred by aberrant dopamine signaling. Incubating mutant worms in liquid medium leads to swimming-induced paralysis. In the L1 larval stage, this phenotype is linked to lethality and cannot be rescued by a dop-3 null mutant. In contrast, mild paralysis occurring in the L4 larval stage is suppressed by dop-3, suggesting defects in dopaminergic signaling. In summary, we show that TSP-17 protects against neurodegeneration and has a role in modulating behaviors linked to dopamine signaling
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