2,165 research outputs found
Initial test results on bolometers for the Planck high frequency instrument
We summarize the fabrication, flight qualification, and dark performance of bolometers completed at the Jet Propulsion Laboratory for the High Frequency Instrument (HFI) of the joint ESA/NASA Herschel/Planck mission to be launched in 2009. The HFI is a multicolor focal plane which consists of 52 bolometers operated at 100 mK. Each bolometer is mounted to a feedhorn-filter assembly which defines one of six frequency bands centered between 100-857 GHz. Four detectors in each of five bands from 143-857 GHz are coupled to both linear polarizations and thus measure the total intensity. In addition, eight detectors in each of four bands (100, 143, 217, and 353 GHz) couple only to a single linear polarization and thus provide measurements of the Stokes parameters, Q and U, as well as the total intensity. The measured noise equivalent power (NEP) of all detectors is at or below the background limit for the telescope and time constants are a few ms, short enough to resolve point sources as the 5 to 9 arc min beams move across the sky at 1 rpm
Role of transport performance on neuron cell morphology
The compartmental model is a basic tool for studying signal propagation in
neurons, and, if the model parameters are adequately defined, it can also be of
help in the study of electrical or fluid transport. Here we show that the input
resistance, in different networks which simulate the passive properties of
neurons, is the result of an interplay between the relevant conductances,
morphology and size. These results suggest that neurons must grow in such a way
that facilitates the current flow. We propose that power consumption is an
important factor by which neurons attain their final morphological appearance.Comment: 9 pages with 3 figures, submitted to Neuroscience Letter
Diagnostic validity of early-onset obsessive-compulsive disorder in the Danish Psychiatric Central Register:findings from a cohort sample
Employing national registers for research purposes depends on a high diagnostic validity. The aim of the present study was to examine the diagnostic validity of recorded diagnoses of early-onset obsessive-compulsive disorder (OCD) in the Danish Psychiatric Central Register (DPCR)
Optical excitations in organic molecules, clusters and defects studied by first-principles Green's function methods
Spectroscopic and optical properties of nanosystems and point defects are
discussed within the framework of Green's function methods. We use an approach
based on evaluating the self-energy in the so-called GW approximation and
solving the Bethe-Salpeter equation in the space of single-particle
transitions. Plasmon-pole models or numerical energy integration, which have
been used in most of the previous GW calculations, are not used. Fourier
transforms of the dielectric function are also avoided. This approach is
applied to benzene, naphthalene, passivated silicon clusters (containing more
than one hundred atoms), and the F center in LiCl. In the latter, excitonic
effects and the defect line are identified in the energy-resolved
dielectric function. We also compare optical spectra obtained by solving the
Bethe-Salpeter equation and by using time-dependent density functional theory
in the local, adiabatic approximation. From this comparison, we conclude that
both methods give similar predictions for optical excitations in benzene and
naphthalene, but they differ in the spectra of small silicon clusters. As
cluster size increases, both methods predict very low cross section for
photoabsorption in the optical and near ultra-violet ranges. For the larger
clusters, the computed cross section shows a slow increase as function of
photon frequency. Ionization potentials and electron affinities of molecules
and clusters are also calculated.Comment: 9 figures, 5 tables, to appear in Phys. Rev. B, 200
Interprofessional spiritual care education in pediatric hematology-oncology: A pilot study.
Background
Evidence and clinical guidelines call care team members to address the spiritual well-being of pediatric patients, especially adolescents and young adults (AYA), with cancer and blood disorders. However, the lack of relevant training in generalist spiritual care has been a key barrier. Therefore, we aimed to improve clinicians’ capabilities by utilizing the Interprofessional Spiritual Care Education Curriculum (ISPEC) to close this gap in pediatric hematology-oncology. A model of interprofessional spiritual care entails that all team members attend to patients’ spirituality by employing generalist spiritual care skills and collaborating with spiritual care specialists such as chaplains.
Methods
Interdisciplinary team members providing care for AYA with cancer and blood disorders were recruited to participate in interprofessional spiritual care education. Our intervention combined an evidence-based online curriculum and in-person discussion groups. Pretest-posttest study examined changes in participants’ skills and practices to identify, address, and discuss spiritual concerns. Surveys were conducted at baseline and at 1, 3, and 6 months after the intervention.
Results
Participants (n = 21) included physicians, advanced practice providers, nurse coordinators, and psychosocial team members. We observed positive changes in participants’ ability (36%, P < 0.01), frequency (56%, P = 0.01), confidence (32%, P < 0.01), and comfort (31%, P = 0.02) providing generalist spiritual care baseline versus one month, with significant gains maintained through six months (Omnibus P < 0.05).
Conclusions
Utilizing ISPEC, interprofessional spiritual care education has a strong potential to develop pediatric hematology-oncology team members’ capabilities to attend to the spiritual aspect of whole-person care and thus contribute to the well-being of AYA with cancer and blood disorders
Abundance analysis of the outer halo globular cluster Palomar 14
We determine the elemental abundances of nine red giant stars belonging to
Palomar 14 (Pal 14). Pal 14 is an outer halo globular cluster (GC) at a
distance of \sim 70 kpc. Our abundance analysis is based on high-resolution
spectra and one-dimensional stellar model atmospheres.We derived the abundances
for the iron peak elements Sc, V, Cr, Mn, Co, Ni, the {\alpha}-elements O, Mg,
Si, Ca, Ti, the light odd element Na, and the neutron-capture elements Y, Zr,
Ba, La, Ce, Nd, Eu, Dy, and Cu. Our data do not permit us to investigate light
element (i.e., O to Mg) abundance variations. The neutron-capture elements show
an r-process signature. We compare our measurements with the abundance ratios
of inner and other outer halo GCs, halo field stars, GCs of recognized
extragalactic origin, and stars in dwarf spheroidal galaxies (dSphs). The
abundance pattern of Pal 14 is almost identical to those of Pal 3 and Pal 4,
the next distant members of the outer halo GC population after Pal 14. The
abundance pattern of Pal 14 is also similar to those of the inner halo GCs,
halo field stars, and GCs of recognized extragalactic origin, but differs from
what is customarily found in dSphs field stars. The abundance properties of Pal
14 as well as those of the other outer halo GCs are thus compatible with an
accretion origin from dSphs. Whether or not GC accretion played a role, it
seems that the formation conditions of outer halo GCs and GCs in dSphs were
similar.Comment: 19 pages, 15 figures. Accepted by A&
Influence of smoking and obesity on alveolar-arterial gas pressure differences and dead space ventilation at rest and peak exercise in healthy men and women
SummaryBackground and aimsBesides exercise intolerance, the assessment of ventilatory and perfusion adequacy allows additional insights in the disease pathophysiology in many cardiovascular or pulmonary diseases. Valid measurements of dead space/tidal volume ratios (VD/VT), arterial (a′) – end-tidal (et) carbon dioxide (CO2) and oxygen (O2) pressure differences (p(a′-et)CO2) and (p(et-a′)O2), and alveolar (A)–a′ O2 pressure differences (p(A-a′)O2) require using blood samples in addition to gas exchange analyses on a breath-by-breath-basis. Smoking and nutritional status are also important factors in defining disorders. Using a large healthy population we considered the impact of these factors to develop useful prediction equations.Methods and resultsIncremental cycle exercise protocols were applied to apparently healthy volunteer adults who did not have structural heart disease or echocardiographic or lung function pathologies. Age, height, weight, and smoking were analysed for their influence on the target parameters in each gender. Reference values were determined by regression analyses. The final study sample consisted of 476 volunteers (190 female), aged 25–85 years. Smoking significantly influences p(A-a′)O2 and p(a′-et)CO2 at rest and peak exercise, and VD/VT during exercise. Obesity influences upper limits of VD/VT, p(a′-et)CO2 and p(et-a′)O2 at rest as well as p(A-a′)O2 and p(et-a′)O2 at exercise. Reference equations for never-smokers as well as for apparently healthy smokers considering influencing factors are given.ConclusionGender, age, height, weight, and smoking significantly influence gas exchange. Considering all of these factors this study provides a comprehensive set of reference equations derived from a large number of participants of a population-based study
Passive water control at the surface of a superhydrophobic lichen
Some lichens have a super-hydrophobic upper surface, which repels water drops, keeping the surface dry but probably preventing water uptake. Spore ejection requires water and is most efficient just after rainfall. This study was carried out to investigate how super-hydrophobic lichens manage water uptake and repellence at their fruiting bodies, or podetia. Drops of water were placed onto separate podetia of Cladonia chlorophaea and observed using optical microscopy and cryo-scanning-electron microscopy (cryo-SEM) techniques to determine the structure of podetia and to visualise their interaction with water droplets. SEM and optical microscopy studies revealed that the surface of the podetia was constructed in a three-level structural hierarchy. By cryo-SEM of water-glycerol droplets placed on the upper part of the podetium, pinning of the droplet to specific, hydrophilic spots (pycnidia/apothecia) was observed. The results suggest a mechanism for water uptake, which is highly sophisticated, using surface wettability to generate a passive response to different types of precipitation in a manner similar to the Namib Desert beetle. This mechanism is likely to be found in other organisms as it offers passive but selective water control
Abundant Lipid and Protein Components of Drusen
Drusen are extracellular lesions characteristic of aging and age-related maculopathy, a major retinal disease of the elderly. We determined the relative proportions of lipids and proteins in drusen capped with retinal pigment epithelium (RPE) and in RPE isolated from non-macular regions of 36 human retinas with grossly normal maculas obtained <6 hr after death.Druse pellets were examined by light and electron microscopy. Component proteins were extracted using novel methods for preserved tissues, separated, subjected to tryptic digestion and LC-MS(MS)(2) analysis using an ion trap mass spectrometer, and identified with reference to databases. Lipid classes were separated using thin layer chromatography and quantified by densitometry. Major druse components were esterified cholesterol (EC), phosphatidylcholine (PC), and protein (37.5+/-13.7, 36.9+/-12.9, and 43.0+/-11.5 ng/druse, respectively). Lipid-containing particles (median diameter, 77 nm) occupied 37-44% of druse volume. Major proteins include vitronectin, complement component 9, apoE, and clusterin, previously seen in drusen, and ATP synthase subunit beta, scavenger receptor B2, and retinol dehydrogenase 5, previously seen in RPE. Drusen and RPE had similar protein profiles, with higher intensities and greater variability in drusen. C8, part of the complement membrane attack complex, was localized in drusen by immunofluorescence.At least 40% of druse content is comprised by lipids dominated by EC and PC, 2 components that are potentially accounted for by just one pathway, the secretion of lipoproteins by RPE. Manipulating genes encoding apolipoprotein pathways would be a fruitful approach to producing drusen with high EC content in laboratory animals. Therapies that directly mitigate drusen should prepare for the substantial volume of neutral lipids. The catalog of major druse proteins is nearing completion
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