9,989 research outputs found
Variability of the HeI5876 A line in early type chemically peculiar stars
Chemically peculiar stars present spectral and photometric variability with a
single period. In the oblique rotator model, the non homogeneous distribution
of elements on the stellar surface is at the origin of the observed variations.
As to helium weak stars, it has been suggested that photometric and helium line
equivalent width variations are out of phase. To understand the behaviour of
helium in CP stars, we have obtained time resolved spectra of the HeI5876 A
line for a sample of 16 chemically peculiar stars in the spectral range B3 --
A1 and belonging to different sub-groups. The HeI5876 A line is too weak to be
measured in the spectra of the stars HD 24155, HD 41269, and HD 220825. No
variation of the equivalent width of the selected He line has been revealed in
the stars HD 22920, HD 24587, HD 36589, HD 49606, and HD 209515. The equivalent
width variation of the HeI5876 A line is in phase with the photometric
variability for the stars HD 43819, HD 171247 and HD 176582. On the contrary it
is out of phase for the stars HD 28843, HD 182255 and HD 223640. No clear
relation has been found for the stars HD 26571 and HD 177003.Comment: 8 pages, 9 figures. 1998, A&AS in pres
Soft drink and juice consumption and renal cell carcinoma incidence and mortality in the european prospective investigation into cancer and nutrition
The Morphology and Emergence Patterns of the Cercaria of Allocreadium pseudotritoni Rankin 1937 (Trematoda: Allocreadiidae)
Author Institution: Department of Biological Sciences, University of CincinnatiCercariae of Allocreadium pseudotritoni, a trematode parasite of salamanders, develop in the sphaeriid clam, Pisidium casertanum, and have the eyespots and stylet (ophthalmoxiphidiocercaria) characteristic of this larval stage in the genus Allocreadium. Allocreadium pseudotritoni cercariae are further characterized by a flame cell formula 2[(4 + 4 + 4) + (4 + 4 + 4)] = 48, three pairs of penetration glands, cystogenous glands, and a slender unadorned tail. Maximum cercarial emergence occurs within three hours of the onset of light with large numbers from individual clams usually appearing in a single day
Comparing Engagement in Advance Care Planning Between Stages of Heart Failure
Indiana University-Purdue University Indianapolis (IUPUI)Heart failure is a terminal disease with an unpredictable trajectory. Family
members of patients with heart failure are often called upon to make decisions about
treatment and end of life care, sometimes with little guidance as to the patients’ wishes.
Advance care planning (ACP) is an ongoing process by which patients make decisions
about their future healthcare. Only about one-third of patients with heart failure have
participated in ACP, which is a similar percentage to the overall population. Despite
increased focus on ACP and interventions to improve it, the rates of ACP in the
population remain relatively unchanged. There is a need to develop interventions that are
targeted based on patient engagement in the process rather than the existing broad-based
interventions.
The purpose of this dissertation study is to examine the relationship between the
American Heart Association stage of heart failure and readiness to engage in advance
care planning. The study consisted of mailed surveys that consisted of demographic
questionnaires and the Advance Care Planning Engagement Survey. Engagement was
analyzed in relation to heart failure stage, heart failure class, comorbidities, perception of
health status, recent hospitalizations, making healthcare decisions for others, and
demographic variables. The results demonstrated that although there was no significant
association between heart failure stage or class and engagement in advance care planning,
there were significant associations between medical comorbidities and advance care
planning engagement. Other significantly associated participant characteristics included age, gender, education, ethnicity, and income. Findings suggest that people with multiple
comorbid conditions will be more likely to be ready to engage in ACP than those with
fewer health conditions. The results from this study will contribute to the development of
strategies to improve advance care planning that are targeted based on engagement level
Low radiation dose in computed tomography: the role of iodine
Recent approaches to reducing radiation exposure during CT examinations typically utilize automated dose modulation strategies on the basis of lower tube voltage combined with iterative reconstruction and other dose-saving techniques. Less clearly appreciated is the potentially substantial role that iodinated contrast media (CM) can play in low-radiation-dose CT examinations. Herein we discuss the role of iodinated CM in low-radiation-dose examinations and describe approaches for the optimization of CM administration protocols to further reduce radiation dose and/or CM dose while maintaining image quality for accurate diagnosis. Similar to the higher iodine attenuation obtained at low-tube-voltage settings, high-iodine-signal protocols may permit radiation dose reduction by permitting a lowering of mAs while maintaining the signal-to-noise ratio. This is particularly feasible in first pass examinations where high iodine signal can be achieved by injecting iodine more rapidly. The combination of low kV and IR can also be used to reduce the iodine dose. Here, in optimum contrast injection protocols, the volume of CM administered rather than the iodine concentration should be reduced, since with high-iodine-concentration CM further reductions of iodine dose are achievable for modern first pass examinations. Moreover, higher concentrations of CM more readily allow reductions of both flow rate and volume, thereby improving the tolerability of contrast administration
Lumped element kinetic inductance detectors maturity for space-borne instruments in the range between 80 and 180 GHz
This work intends to give the state-of-the-art of our knowledge of the
performance of LEKIDs at millimetre wavelengths (from 80 to 180~GHz). We
evaluate their optical sensitivity under typical background conditions and
their interaction with ionising particles. Two LEKID arrays, originally
designed for ground-based applications and composed of a few hundred pixels
each, operate at a central frequency of 100, and 150~GHz (
about 0.3). Their sensitivities have been characterised in the laboratory using
a dedicated closed-circle 100~mK dilution cryostat and a sky simulator,
allowing for the reproduction of realistic, space-like observation conditions.
The impact of cosmic rays has been evaluated by exposing the LEKID arrays to
alpha particles (Am) and X sources (Cd) with a readout sampling
frequency similar to the ones used for Planck HFI (about 200~Hz), and also with
a high resolution sampling level (up to 2~MHz) in order to better characterise
and interpret the observed glitches. In parallel, we have developed an
analytical model to rescale the results to what would be observed by such a
LEKID array at the second Lagrangian point.Comment: 7 pages, 2 tables, 13 figure
Uniform non-stoichiometric titanium nitride thin films for improved kinetic inductance detector array
We describe the fabrication of homogeneous sub-stoichiometric titanium
nitride films for microwave kinetic inductance detector (mKID) arrays. Using a
6 inch sputtering target and a homogeneous nitrogen inlet, the variation of the
critical temperature over a 2 inch wafer was reduced to <25 %. Measurements of
a 132-pixel mKID array from these films reveal a sensitivity of 16 kHz/pW in
the 100 GHz band, comparable to the best aluminium mKIDs. We measured a noise
equivalent power of NEP = 3.6e-15 W/Hz^(1/2). Finally, we describe possible
routes to further improve the performance of these TiN mKID arrays.Comment: 7 pages, 4 figures, submitted to Journal of low temperature physics,
Proceedings of LTD-1
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