15,417 research outputs found
Low level radiation altimeter system study
Low level radiation altimeter for measuring altitude 50 feet above lunar surfac
SCRIPTKELL : a tool for measuring cognitive effort and time processing in writing and other complex cognitive activities
We present SCRIPTKELL, a computer-assisted experimental tool that makes it possible to measure the time and cognitive effort allocated to the subprocesses of writing and other cognitive activities, SCRIPTKELL was designed to easily use and modulate Kellogg's (1986) triple-task procedure,.which consists of a combination of three tasks: a writing task (or another task), a reaction time task (auditory signal detection), and a directed retrospection task (after each signal detection during writing). We demonstrate how this tool can be used to address several novel empirical and theoretical issues. In sum, SCRIPTKELL should facilitate the flexible realization of experimental designs and the investigation of critical issues concerning the functional characteristics of complex cognitive activities
Thermoregulation of the \u3ci\u3epap\u3c/i\u3e Operon: Evidence for the Involvement of RimJ, the N-terminal Acetylase of Ribosomal Protein S5
Our previous work showed that pap pilin gene transcription is subject to a thermoregulatory control mechanism under which pap pilin is not transcribed at a low temperature (23°C) (L. B. Blyn, B. A. Braaten, C. A. White-Ziegler, D. H. Rolfson, and D. A. Low, EMBO J. 8:613-620, 1989). In order to isolate genes involved in this temperature regulation of gene expression, chromosomal mini-TnlO (mTnlO) mutations that allowed transcription of the pap pilin gene at 23°C were identified, and the locus was designated tcp, for thermoregulatory control of pap (C. A. White-Ziegler, L. B. Blyn, B. A. Braaten, and D. A. Low, J. Bacteriol. 172:1775-1782, 1990). In the present study, quantitative analysis showed that the tcp mutations restore pap pilin transcription at 23°C to levels similar to those measured at 37°C. By in vivo recombination, the tcp mutations were mapped to phage E4H1OS of the Kohara library of the Escherichia coli chromosome (Y. Kohara, K. Akiyama, and K. Isono, Cell 50:495-508, 1987). The tcp locus was cloned by complementation, in which a 1.3-kb DNA fragment, derived from the Kohara phage, was shown to restore thermoregulation to the mTnlO mutants. DNA sequencing revealed two open reading frames (ORFs) encoding proteins with calculated molecular masses of 22.7 and 20.3 kDa. The sequence of the 22.7-kDa ORF was identical to that of rimJ, the N-terminal acetylase of the ribosomal protein S5. The gene encoding the 20.3-kDa ORF, designated g20.3 here, did not display significant homology to any known. DNA or protein sequence. On the basis of Northern (RNA) blot data, rimj and g20.3 are located within the same operon. Two of the mTnlO transposons in the thermoregulatory mutants were inserted within the coding region of rimi, indicating that the RimJ protein plays an important role in the temperature regulation ofpap pilin gene transcription. However, rimj itself is not thermoregulated, since rim. transcripts were detected at both 23 and 37°C. Disruption of the g20.3 gene by insertion and deletion mutagenesis did not affect thermoregulation of the pap operon, suggesting that, although g20.3 lies within the same operon as rimj, it does not play a role in thermoregulation
HESS J1826130: A Very Hard -Ray Spectrum Source in the Galactic Plane
HESS J1826130 is an unidentified hard spectrum source discovered by
H.E.S.S. along the Galactic plane, the spectral index being = 1.6 with
an exponential cut-off at about 12 TeV. While the source does not have a clear
counterpart at longer wavelengths, the very hard spectrum emission at TeV
energies implies that electrons or protons accelerated up to several hundreds
of TeV are responsible for the emission. In the hadronic case, the VHE emission
can be produced by runaway cosmic-rays colliding with the dense molecular
clouds spatially coincident with the H.E.S.S. source.Comment: 6 pages, 3 figures, Proceedings of the 6th International Symposium on
High Energy Gamma-Ray Astronomy (Gamma2016), Heidelberg, German
The reaction 13C(alpha,n)16O: a background for the observation of geo-neutrinos
The absolute cross section of the C(,n)O reaction has
been measured at E = 0.8 to 8.0 MeV with an overall accuracy of 4%.
The precision is needed to subtract reliably a background in the observation of
geo-neutrinos, e.g. in the KamLAND detector.Comment: LaTex file, 13 pages including 3 ps figures. Any request to
[email protected]. Phys. Rev . C, to appea
Scaling near random criticality in two-dimensional Dirac fermions
Recently the existence of a random critical line in two dimensional Dirac
fermions is confirmed. In this paper, we focus on its scaling properties,
especially in the critical region. We treat Dirac fermions in two dimensions
with two types of randomness, a random site (RS) model and a random hopping
(RH) model. The RS model belongs to the usual orthogonal class and all states
are localized. For the RH model, there is an additional symmetry expressed by
. Therefore, although all non-zero energy states
localize, the localization length diverges at the zero energy. In the weak
localization region, the generalized Ohm's law in fractional dimensions,
, has been observed for the RH model.Comment: RevTeX with 4 postscript figures, To appear in Physical Review
CLASH-VLT: Strangulation of cluster galaxies in MACSJ0416.1-2403 as seen from their chemical enrichment
(abridged) We explore the Frontier Fields cluster MACS J0416.1-2403 at
z=0.3972 with VIMOS/VLT spectroscopy from the CLASH-VLT survey covering a
region which corresponds to almost three virial radii. We measure fluxes of 5
emission lines of 76 cluster members enabling us to unambiguously derive O/H
gas metallicities, and also SFRs from Halpha. For intermediate massses we find
a similar distribution of cluster and field galaxies in the MZR and mass vs.
sSFR diagrams. Bulge-dominated cluster galaxies have on average lower sSFRs and
higher O/Hs compared to their disk-dominated counterparts. We use the location
of galaxies in the projected velocity vs. position phase-space to separate our
cluster sample into a region of objects accreted longer time ago and a region
of recently accreted and infalling galaxies. We find a higher fraction of
accreted metal-rich galaxies (63%) compared to the fraction of 28% of
metal-rich galaxies in the infalling regions. Intermediate mass galaxies
falling into the cluster for the first time are found to be in agreement with
predictions of the fundamental metallicity relation. In contrast, for already
accreted star-forming galaxies of similar masses, we find on average
metallicities higher than predicted by the models. This trend is intensified
for accreted cluster galaxies of the lowest mass bin, that display
metallicities 2-3 times higher than predicted by models with primordial gas
inflow. Environmental effects therefore strongly influence gas regulations and
control gas metallicities of log(M/Msun)<10.2 (Salpeter IMF) cluster galaxies.
We also investigate chemical evolutionary paths of model galaxies with and
without inflow of gas showing that strangulation is needed to explain the
higher metallicities of accreted cluster galaxies. Our results favor a
strangulation scenario in which gas inflow stops for log(M/Msun)<10.2 galaxies
when accreted by the cluster.Comment: Version better matched to the published version, including table with
observed and derived quantities for the 76 cluster galaxie
Nonlinear electromagnetic response of graphene: Frequency multiplication and the self-consistent-field effects
Graphene is a recently discovered carbon based material with unique physical
properties. This is a monolayer of graphite, and the two-dimensional electrons
and holes in it are described by the effective Dirac equation with a vanishing
effective mass. As a consequence, electromagnetic response of graphene is
predicted to be strongly non-linear. We develop a quasi-classical kinetic
theory of the non-linear electromagnetic response of graphene, taking into
account the self-consistent-field effects. Response of the system to both
harmonic and pulse excitation is considered. The frequency multiplication
effect, resulting from the non-linearity of the electromagnetic response, is
studied under realistic experimental conditions. The frequency up-conversion
efficiency is analysed as a function of the applied electric field and
parameters of the samples. Possible applications of graphene in terahertz
electronics are discussed.Comment: 14 pages, 7 figures, invited paper written for a special issue of
JPCM "Terahertz emitters
Emotions while awaiting lung transplantation : a comprehensive qualitative analysis
Patients awaiting lung transplantation are at risk of negative emotional and physical experiences. How do they talk about emotions? Semi-structured interviews were performed (15 patients). Categorical analysis focusing on emotion-related descriptions was organized into positive–negative–neutral descriptions: for primary and secondary emotions, evaluation processes, coping strategies, personal characteristics, emotion descriptions associated with physical states, (and) contexts were listed. Patients develop different strategies to maintain positive identity and attitude, while preserving significant others from extra emotional load. Results are discussed within various theoretical and research backgrounds, in emphasizing their importance in the definition of emotional support starting from the patient’s perspective
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