514 research outputs found
Effect of remobinant granulocyte-macrophage colony stimulating factor (GM-CSF) on leukopenia in AIDS
Client self-assessment in community aged care: A comparative study involving older Australians and their case managers
Self-assessment of support needs is a relatively new and under-researched phenomenon in domiciliary aged care. This article outlines the results of a comparative study focusing on whether a self-assessment approach assists clients to identify support needs and the degree to which self-assessed needs differ from an assessment conducted by community care professionals. A total of 48 older people and their case managers completed a needs assessment tool. Twenty-two semi-structured interviews were used to ascertain older people’s views and preferences regarding the self-assessment process. The study suggests that while a co-assessment approach as outlined in this article has the potential to assist older people to gain a better understanding of their care needs as well as the assessment process and its ramifications, client self-assessment should be seen as part of a co-assessment process involving care professionals. Such a co-assessment process allows older people to gain a better understanding of their support needs and the wider community aged care context. The article suggests that a co-assessment process involving both clients and care professionals contains features that have the capacity to enhance domiciliary aged care
The Coronae of AR Lac
We observed the coronally active eclipsing binary, AR Lac, with the High
Energy Transmission Grating on Chandra for a total of 97 ks, spaced over five
orbits, at quadratures and conjunctions. Contemporaneous and simultaneous EUV
spectra and photometry were also obtained with the Extreme Ultraviolet
Explorer. Significant variability in both X-ray and EUV fluxes were observed,
dominated by at least one X-ray flare and one EUV flare. We saw no evidence of
primary or secondary eclipses. X-ray flux modulation was largest at high
temperature, indicative of flare heating of coronal plasma. Line widths
interpreted in terms of Doppler broadening suggest that both binary stellar
components are active. From line fluxes obtained from total integrated spectra,
we have modeled the emission measure and abundance distributions. A strong
maximum was found in the differential emission measure, characterized by peaks
at log T = 6.9 and 7.4, together with a weak but significant cooler maximum
near log T=6.2, and a moderately strong hot tail from log T= 7.6-8.2. Coronal
abundances have a broad distribution and show no simple correlation with first
ionization potential. While the resulting model spectrum generally agrees very
well with the observed spectrum, there are some significant discrepancies,
especially among the many Fe L-lines. Both the emission measure and abundance
distributions are qualitatively similar to prior determinations from other
X-ray and ultraviolet spectra, indicating some long-term stability in the
overall coronal structure.Comment: 31 pages, 8 figures, 3 tables; Accepted for publication in the
Astrophysical Journal (tentatively October 1, 2003
The photospheric abundances of active binaries III. Abundance peculiarities at high activity level
We report the determination from high-resolution spectra of the atmospheric
parameters and abundances of 13 chemical species (among which lithium) in 8
single-lined active binaries. These data are combined with our previous results
for 6 other RS CVn systems to examine a possible relationship between the
photospheric abundance patterns and the stellar activity level. The stars
analyzed are generally found to exhibit peculiar abundance ratios compared to
inactive, galactic disk stars of similar metallicities. We argue that this
behaviour is unlikely an artefact of errors in the determination of the
atmospheric parameters or non-standard mixing processes along the red giant
branch, but diagnoses instead the combined action of various physical processes
related to activity. The most promising candidates are cool spot groups
covering a very substantial fraction of the stellar photosphere or NLTE effects
arising from nonthermal excitation. However, we cannot exclude the possibility
that more general shortcomings in our understanding of K-type stars (e.g.
inadequacies in the atmospheric models) also play a significant role. Lastly,
we call attention to the unreliability of the (V-R) and (V-I) colour indices as
temperature indicators in chromospherically active stars.Comment: Accepted for publication in A&A, 17 pages, 7 figures (6 in colour
X-Ray Spectroscopy of Stars
(abridged) Non-degenerate stars of essentially all spectral classes are soft
X-ray sources. Low-mass stars on the cooler part of the main sequence and their
pre-main sequence predecessors define the dominant stellar population in the
galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense,
of X-ray spectra from the solar corona. X-ray emission from cool stars is
indeed ascribed to magnetically trapped hot gas analogous to the solar coronal
plasma. Coronal structure, its thermal stratification and geometric extent can
be interpreted based on various spectral diagnostics. New features have been
identified in pre-main sequence stars; some of these may be related to
accretion shocks on the stellar surface, fluorescence on circumstellar disks
due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot
stars clearly dominate the interaction with the galactic interstellar medium:
they are the main sources of ionizing radiation, mechanical energy and chemical
enrichment in galaxies. High-energy emission permits to probe some of the most
important processes at work in these stars, and put constraints on their most
peculiar feature: the stellar wind. Here, we review recent advances in our
understanding of cool and hot stars through the study of X-ray spectra, in
particular high-resolution spectra now available from XMM-Newton and Chandra.
We address issues related to coronal structure, flares, the composition of
coronal plasma, X-ray production in accretion streams and outflows, X-rays from
single OB-type stars, massive binaries, magnetic hot objects and evolved WR
stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures
(partly multiple); some corrections made after proof stag
Importance of the loading factor in transport CO2 emissions
This paper is focusing on the influence of the loading factor on CO2 emissions, from freight and passengers. A
common approach in economics to relate greenhouse gas (GHG) emissions to economic activity is the ASIF model (Unander & Schipper 2000). However, this model has been
elaborated for all economic sectors, and it doesn’t take into account the vehicle load factor for the calculation of transport emissions. The objective of this paper is to include the loading factor into the ASIF approach. First, we will include this loading factor into the ASIF equation, aggregating step by step from trip level to macro level; loading will appear as a result of empty running, vehicle capacity and occupancy rate (section 2). Then section 3 will analyse the relationship between loading factor and energy consumption, per type of vehicle. Section 4 will focus on issues concerning freight, as well as section 5 for passengers. The examples will be mainly taken from road transport, which causes most of transport CO2 emissions. Then our conclusion will draw attention on data needs and policy implications
Ephyrae and metaephyrae of Pelagia noctiluca: stage determination, morphometry and shrinkage
Understanding processes occurring in the different life stages of jellyfish is key to advance knowledge on their trophic interactions and population dynamics. We describe four developmental stages of Pelagia noctiluca ephyrae and metaephyrae based on the progress of feeding structures and morphometric measurements on the central disc diameter and total body diameter. Size differs significantly among stages, but it can overlap substantially, suggesting that it is not always coupled with development progress due to different somatic growth. Morphological distinction of stages is biologically important because it implies different levels of food specialization and capture efficiency. We further report a 25% (±13 SD) shrinkage of ephyrae and metaephyrae after storage in 4% formaldehyde solution. This metric can be used in ecological studies focusing on size-related traits of field observed individuals.Postprint1,74
Bluefin tuna larval indices in the western Mediterranean, ecological and analytycal sources of uncertainity
The main objective of this study is to provide the knowledge to design adequate sensitivity
analyses on the assessment models used for the Eastern stock of Bluefin tuna. We analyze how
different configuration for the same environmental variable (temperature in the mixed layer
depth) and different modeling approaches (nonlinear Delta-log,delta-gamma, tweedy and
bayesian) affects to the variability of the larval indices of the Eastern bluefin tuna from data
collected in the Balearic Sea (Western Mediterranean). We also investigate the effects on the
index caused from having differences in the total sampled area among years. We used these
results to interpolate larval index values in years with not standard larval surveys but with some
ichthyoplankton surveys available, and to propose a “revised version” of the index providing
parameters of uncertainty
Small fish eat smaller fish: A model of interaction strength in early life stages of two tuna species
Fish larvae are rarely a major driver of fish mortality, but tunas can produce large batches of larvae that rapidly develop the capacity to kill other fish. We combine a model for the killing potential from Atlantic bluefin tuna (BFT) larvae on larval albacore (ALB) with field observations at a major spawning ground. Both species spawn from June to August, but BFT has a narrow spawning peak at the beginning of the season that results in priority effects. Our model shows that, following a recent stock recovery, BFT larvae have increased their killing pressure, leaving areas of up to 1000 km2 with < 1% chance of ALB daily survival. Such increase in killing pressure suggests larval ALB has reduced chances to survive; yet in large areas with few BFT, other drivers of early survival prevail over BFT predation. This shows that strong predatory interactions can occur during larval stages in some fishes.En prensa3,38
Spawning site distribution of a bluefin tuna reduces jellyfish predation on early life stages
Bluefin tunas across the world migrate long distances to spawn in particularly warm and oligotrophic areas constrained by oceanographic fronts. The low abundance of predators in these areas increases survival chances of their early life stages, but its importance for choice of spawning habitat is unknown. Here, we use estimated clearance rates and data on spatial distributions of Atlantic bluefin tuna larvae Thunnus thynnus and metaephyrae of the jellyfish Pelagia noctiluca to quantify predation at a major spawning ground in the Mediterranean Sea. We found that high densities of P. noctiluca can rapidly deplete tuna eggs and preflexion larvae, but their patchy distribution and low spatial and temporal overlap results in overall low predation. The specific distribution of the spawning sites suggests that bluefin tunas may use local oceanography as cues to spawn outside areas with high predator densities.Postprint3,38
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