286 research outputs found
Criterion validity of the Center for Epidemiologic Studies Depression scale (CES-D): results from a community-based sample of older subject in the Netherlands
The Center for Epidemiologic Studies Depression scale (CES-D) has been widely used in studies of late-life depression. Psychometric properties are generally favourable, but data on the criterion validity of the CES-D in elderly community-based samples are lacking. In a sample of older (55-85 years) inhabitants of the Netherlands, 487 subjects were selected to study criterion validity of the CES-D. Using the 1-month prevalence of major depression derived from the Diagnostic Interview Schedule (DIS) as criterion, the weighted sensitivity of the CES-D was 100%; specificity 88%; and positive predictive value 13.2%. False positives were not more likely among elderly with physical illness, cognitive decline or anxiety. We conclude that the criterion validity of the CES-D for major depression was very satisfactory in this sample of older adults
Monitoring the T-Cell Receptor Repertoire at Single-Clone Resolution
The adaptive immune system recognizes billions of unique antigens using highly variable T-cell receptors. The αβ T-cell receptor repertoire includes an estimated 10(6) different rearranged β chains per individual. This paper describes a novel micro-array based method that monitors the β chain repertoire with a resolution of a single T-cell clone. These T-arrays are quantitative and detect T-cell clones at a frequency of less than one T cell in a million, which is 2 logs more sensitive than spectratyping (immunoscope), the current standard in repertoire analysis. Using T-arrays we detected CMV-specific CD4+ and CD8+ T-cell clones that expanded early after viral antigen stimulation in vitro and in vivo. This approach will be useful in monitoring individual T-cell clones in diverse experimental settings, and in identification of T-cell clones associated with infectious disease, autoimmune disease and cancer
Isospin Asymmetry in Nuclei and Neutron Stars
The roles of isospin asymmetry in nuclei and neutron stars are investigated
using a range of potential and field-theoretical models of nucleonic matter.
The parameters of these models are fixed by fitting the properties of
homogeneous bulk matter and closed-shell nuclei. We discuss and unravel the
causes of correlations among the neutron skin thickness in heavy nuclei, the
pressure of beta-equilibrated matter at a density of 0.1 fm, the
derivative of the nuclear symmetry energy at the same density and the radii of
moderate mass neutron stars. Constraints on the symmetry properties of nuclear
matter from the binding energies of nuclei are examined. The extent to which
forthcoming neutron skin measurements will further delimit the symmetry
properties is investigated. The impact of symmetry energy constraints for the
mass and moment of inertia contained within neutron star crusts and the
threshold density for the nucleon direct Urca process, all of which are
potentially measurable, is explored. We also comment on the minimum neutron
star radius, assuming that only nucleonic matter exists within the star.Comment: 49 pages, 17 figures, Phys. Rep. (in press); made improvements to
"RAPR" and corrected transition densitie
Multicore liquid perfluorocarbon-loaded multimodal nanoparticles for stable ultrasound and <sup>19</sup> F MRI applied to in vivo cell tracking
Ultrasound is the most commonly used clinical imaging modality. However, in applications requiring cell-labeling, the large size and short active lifetime of ultrasound contrast agents limit their longitudinal use. Here, 100 nm radius, clinically applicable, polymeric nanoparticles containing a liquid perfluorocarbon, which enhance ultrasound contrast during repeated ultrasound imaging over the course of at least 48 h, are described. The perfluorocarbon enables monitoring the nanoparticles with quantitative 19 F magnetic resonance imaging, making these particles effective multimodal imaging agents. Unlike typical core–shell perfluorocarbon-based ultrasound contrast agents, these nanoparticles have an atypical fractal internal structure. The nonvaporizing highly hydrophobic perfluorocarbon forms multiple cores within the polymeric matrix and is, surprisingly, hydrated with water, as determined from small-angle neutron scattering and nuclear magnetic resonance spectroscopy. Finally, the nanoparticles are used to image therapeutic dendritic cells with ultrasound in vivo, as well as with 19 F MRI and fluorescence imaging, demonstrating their potential for long-term in vivo multimodal imaging. </p
Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation
The current status of electric dipole moments of diamagnetic atoms which
involves the synergy between atomic experiments and three different theoretical
areas -- particle, nuclear and atomic is reviewed. Various models of particle
physics that predict CP violation, which is necessary for the existence of such
electric dipole moments, are presented. These include the standard model of
particle physics and various extensions of it. Effective hadron level combined
charge conjugation (C) and parity (P) symmetry violating interactions are
derived taking into consideration different ways in which a nucleon interacts
with other nucleons as well as with electrons. Nuclear structure calculations
of the CP-odd nuclear Schiff moment are discussed using the shell model and
other theoretical approaches. Results of the calculations of atomic electric
dipole moments due to the interaction of the nuclear Schiff moment with the
electrons and the P and time-reversal (T) symmetry violating
tensor-pseudotensor electron-nucleus are elucidated using different
relativistic many-body theories. The principles of the measurement of the
electric dipole moments of diamagnetic atoms are outlined. Upper limits for the
nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained
combining the results of atomic experiments and relativistic many-body
theories. The coefficients for the different sources of CP violation have been
estimated at the elementary particle level for all the diamagnetic atoms of
current experimental interest and their implications for physics beyond the
standard model is discussed. Possible improvements of the current results of
the measurements as well as quantum chromodynamics, nuclear and atomic
calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for
EPJ
Global data on earthworm abundance, biomass, diversity and corresponding environmental properties
14 p.Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change
- …