1,711 research outputs found
Vector magnetometer design study: Analysis of a triaxial fluxgate sensor design demonstrates that all MAGSAT Vector Magnetometer specifications can be met
The design of the vector magnetometer selected for analysis is capable of exceeding the required accuracy of 5 gamma per vector field component. The principal elements that assure this performance level are very low power dissipation triaxial feedback coils surrounding ring core flux-gates and temperature control of the critical components of two-loop feedback electronics. An analysis of the calibration problem points to the need for improved test facilities
Charmonium mass splittings at the physical point
We present results from an ongoing study of mass splittings of the lowest
lying states in the charmonium system. We use clover valence charm quarks in
the Fermilab interpretation, an improved staggered (asqtad) action for sea
quarks, and the one-loop, tadpole-improved gauge action for gluons. This study
includes five lattice spacings, 0.15, 0.12, 0.09, 0.06, and 0.045 fm, with two
sets of degenerate up- and down-quark masses for most spacings. We use an
enlarged set of interpolation operators and a variational analysis that permits
study of various low-lying excited states. The masses of the sea quarks and
charm valence quark are adjusted to their physical values. This large set of
gauge configurations allows us to extrapolate results to the continuum physical
point and test the methodology.Comment: 7 pp, 6 figs, Lattice 201
Examining the Spatial Ability Phenomenon from the Student's Perspective
This phenomenological investigation examined the lived experience of technically-oriented students over the course of a single semester, attempting to answer the question, “What was it like for a student to experience the spatial ability phenomenon?” The study included 12 interviewees and 8 focus group freshman participants at a Midwestern university. Data sources included interview transcripts, think aloud transcripts, task solutions, focus group transcripts, researcher journal entries, course performance data, course observation data, and spatial ability test data. This paper provides the holistic, structural description of the spatial phenomenon that emerged from the descriptions of the participants’ experience, as well as an expository on four of the five invariant themes that were elicited from the data. the collaborative session. Recommendations were made for future course improvements when a real world project is used in the curriculum. This paper also discusses changes in design process and the role of designers based on the collaborative session feedback
Assessing Exposure to Violence Using Multiple Informants: Application of Hierarchical Linear Model
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72634/1/1469-7610.00692.pd
Imagined Self-Motion Differs from Perceived Self-Motion: Evidence from a Novel Continuous Pointing Method
Background The extent to which actual movements and imagined movements maintain a shared internal representation has been a matter of much scientific debate. Of the studies examining such questions, few have directly compared actual full-body movements to imagined movements through space. Here we used a novel continuous pointing method to a) provide a more detailed characterization of self-motion perception during actual walking and b) compare the pattern of responding during actual walking to that which occurs during imagined walking. Methodology/Principal Findings This continuous pointing method requires participants to view a target and continuously point towards it as they walk, or imagine walking past it along a straight, forward trajectory. By measuring changes in the pointing direction of the arm, we were able to determine participants' perceived/imagined location at each moment during the trajectory and, hence, perceived/imagined self-velocity during the entire movement. The specific pattern of pointing behaviour that was revealed during sighted walking was also observed during blind walking. Specifically, a peak in arm azimuth velocity was observed upon target passage and a strong correlation was observed between arm azimuth velocity and pointing elevation. Importantly, this characteristic pattern of pointing was not consistently observed during imagined self-motion. Conclusions/Significance Overall, the spatial updating processes that occur during actual self-motion were not evidenced during imagined movement. Because of the rich description of self-motion perception afforded by continuous pointing, this method is expected to have significant implications for several research areas, including those related to motor imagery and spatial cognition and to applied fields for which mental practice techniques are common (e.g. rehabilitation and athletics)
HATS-1b: The first transiting planet discovered by the hatsouth survey
We report the discovery of HATS-1b, a transiting extrasolar planet orbiting the moderately bright V = 12.05 G dwarf star GSC 6652-00186, and the first planet discovered by HATSouth, a global network of autonomous wide-field telescopes. HATS-1b has a period of P ≈ 3.4465 days, mass of Mp ≈ 1.86 MJ, and radius of Rp ≈ 1.30 RJ. The host star has a mass of 0.99 M⊙ and radius of 1.04 R⊙. The discovery light curve of HATS-1b has near-continuous coverage over several multi-day timespans, demonstrating the power of using a global network of telescopes to discover transiting planets.Development of the HATSouth project was funded by NSF
MRI grant NSF/AST-0723074, operations are supported by
NASA grant NNX09AB29G, and follow-up observations received
partial support from grant NSF/AST-1108686. Followup
observations with the ESO 2.2 m/FEROS instrument were performed under MPI guaranteed time (P087.A-9014(A),
P088.A-9008(A), P089.A-9008(A)) and Chilean time (P087.C-
0508(A)). A.J. acknowledges support from Fondecyt project
1095213, Ministry of Economy ICM Nuclei P07-021-F and
P10-022-F, Anillo ACT-086 and BASAL CATA PFB-06. V.S.
acknowledges support form BASAL CATA PFB-06. M.R. acknowledges
support from a Fondencyt postdoctoral fellowship
N 3120097 and contributions from the ALMA-CONICYT
FUND Project N 31090015. R.B. and N.E. acknowledge support
from Fondecyt project 1095213. Work at the
Australian National University is supported by ARC Laureate
Fellowship Grant FL0992131. We acknowledge the use of
the AAVSO Photometric All-Sky Survey (APASS), funded by
the Robert Martin Ayers Sciences Fund, and the SIMBAD
database, operated at CDS, Strasbourg, France
Microsomal triglyceride transfer protein expression in adipocytes: A new component in fat metabolism
AbstractMicrosomal triglyceride transfer protein (MTP) is a carrier of triglyceride essential for the assembly of apolipoprotein (apo)B-containing lipoproteins by the liver and the small intestine. Its role in triglyceride transfer in tissues that do not secrete lipoproteins has not been explored. In particular, MTP would seem to be a candidate for a role in triglyceride metabolism within the adipocyte. To test this hypothesis, we probed adipocytes for the presence of MTP. Immunohistochemical and biochemical studies demonstrate MTP in adipocytes from brown and white fat depots of mice and human, as well as in 3T3-L1 cells. Confocal microscopy revealed MTP throughout 3T3 cells; however, MTP fluorescence was prominent in juxtanuclear areas. In differentiated 3T3 cells MTP fluorescence was very striking around lipid droplets. In vitro lipid transfer assays demonstrated the presence of triglyceride transfer activity within microsomal fractions isolated from rat adipose tissue. In addition, quantitative rtPCR studies showed that MTP expression in mouse white fat depots was approximately 1% of MTP expression in mouse liver. MTP mRNA in differentiated 3T3 cells was approximately 13% of liver expression. Our results provide unequivocal evidence for the presence of MTP in adipocytes and present new possibilities for defining the mechanisms by which triglyceride is stored and/or hydrolyzed and mobilized
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