175 research outputs found
Recommended from our members
Distinguishing processing difficulties in inhibition, implicature, and negation
Despite their considerable communicative abilities, youngchildren often have difficulty interpreting complex linguisticstructures in context. Two examples of this phenomenon arenegation and pragmatic implicature, both of which pose some-times surprising difficulties for preschoolers. Both of thesestructures require children to resist a more salient alternativeinterpretation; since executive function abilities develop ex-tensively during childhood, perhaps failures are due to prob-lems in inhibition. To test this hypothesis, we designed tasksto measure inhibitory control, negation, and implicature com-prehension in children and adults. Using standard analyses aswell as drift diffusion models, we found different patterns ofprocessing on all three tasks, and no support for the hypothesisthat inhibitory control per se is playing a role in either adultsâor childrenâs negation or implicature processing. Instead, ouranalyses reveal qualitatively different developmental trajecto-ries, suggesting task-specific factors driving these changes
Siteâspecific weed managementâconstraints and opportunities for the weed research community: Insights from a workshop
The adoption of siteâspecific weed management (SSWM) technologies by farmers is not aligned with the scientific achievements in this field. While scientists have demonstrated significant success in realâtime weed identification, phenotyping and accurate weed mapping by using various sensors and platforms, the integration by farmers of SSWM and weed phenotyping tools into weed management protocols is limited. This gap was therefore a central topic of discussion at the most recent workshop of the SSWM Working Group arranged by the European Weed Research Society (EWRS). This insight paper aims to summarise the presentations and discussions of some of the workshop panels and to highlight different aspects of weed identification and spray application that were thought to hinder SSWM adoption. It also aims to share views and thoughts regarding steps that can be taken to facilitate future implementation of SSWM
Radiomics-based aortic flow profile characterization with 4D phase-contrast MRI
4D PC MRI of the aorta has become a routinely available examination, and a multitude of single parameters have been suggested for the quantitative assessment of relevant flow features for clinical studies and diagnosis. However, clinically applicable assessment of complex flow patterns is still challenging. We present a concept for applying radiomics for the quantitative characterization of flow patterns in the aorta. To this end, we derive cross-sectional scalar parameter maps related to parameters suggested in literature such as throughflow, flow direction, vorticity, and normalized helicity. Derived radiomics features are selected with regard to their inter-scanner and inter-observer reproducibility, as well as their performance in the differentiation of sex-, age- and disease-related flow properties. The reproducible features were tested on user-selected examples with respect to their suitability for characterizing flow profile types. In future work, such signatures could be applied for quantitative flow assessment in clinical studies or disease phenotyping
A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments
PVP-capped silver nanoparticles with a diameter of the metallic core of 70 nm,
a hydrodynamic diameter of 120 nm and a zeta potential of â20 mV were prepared
and investigated with regard to their biological activity. This review
summarizes the physicochemical properties (dissolution, protein adsorption,
dispersability) of these nanoparticles and the cellular consequences of the
exposure of a broad range of biological test systems to this defined type of
silver nanoparticles. Silver nanoparticles dissolve in water in the presence
of oxygen. In addition, in biological media (i.e., in the presence of
proteins) the surface of silver nanoparticles is rapidly coated by a protein
corona that influences their physicochemical and biological properties
including cellular uptake. Silver nanoparticles are taken up by cell-type
specific endocytosis pathways as demonstrated for hMSC, primary T-cells,
primary monocytes, and astrocytes. A visualization of particles inside cells
is possible by X-ray microscopy, fluorescence microscopy, and combined FIB/SEM
analysis. By staining organelles, their localization inside the cell can be
additionally determined. While primary brain astrocytes are shown to be fairly
tolerant toward silver nanoparticles, silver nanoparticles induce the
formation of DNA double-strand-breaks (DSB) and lead to chromosomal
aberrations and sister-chromatid exchanges in Chinese hamster fibroblast cell
lines (CHO9, K1, V79B). An exposure of rats to silver nanoparticles in vivo
induced a moderate pulmonary toxicity, however, only at rather high
concentrations. The same was found in precision-cut lung slices of rats in
which silver nanoparticles remained mainly at the tissue surface. In a human
3D triple-cell culture model consisting of three cell types (alveolar
epithelial cells, macrophages, and dendritic cells), adverse effects were also
only found at high silver concentrations. The silver ions that are released
from silver nanoparticles may be harmful to skin with disrupted barrier (e.g.,
wounds) and induce oxidative stress in skin cells (HaCaT). In conclusion, the
data obtained on the effects of this well-defined type of silver nanoparticles
on various biological systems clearly demonstrate that cell-type specific
properties as well as experimental conditions determine the biocompatibility
of and the cellular responses to an exposure with silver nanoparticles
Analysis of sex and gender-specific research reveals a common increase in publications and marked differences between disciplines
Oertelt-Prigione S, Parol R, Krohn S, PreiĂner R, Regitz-Zagrosek V. Analysis of sex and gender-specific research reveals a common increase in publications and marked differences between disciplines. BMC Medicine. 2010;8(1): 70.© 2010 Oertelt-Prigione et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Disease- and sex-specific differences in patients with heart valve disease: a proteome study
Pressure overload in patients with aortic valve stenosis and volume overload in mitral valve regurgitation trigger specific forms of cardiac remodeling; however, little is known about similarities and differences in myocardial proteome regulation. We performed proteome profiling of 75 human left ventricular myocardial biopsies (aortic stenosis = 41, mitral regurgitation = 17, and controls = 17) using high-resolution tandem mass spectrometry next to clinical and hemodynamic parameter acquisition. In patients of both disease groups, proteins related to ECM and cytoskeleton were more abundant, whereas those related to energy metabolism and proteostasis were less abundant compared with controls. In addition, disease group-specific and sex-specific differences have been observed. Male patients with aortic stenosis showed more proteins related to fibrosis and less to energy metabolism, whereas female patients showed strong reduction in proteostasis-related proteins. Clinical imaging was in line with proteomic findings, showing elevation of fibrosis in both patient groups and sex differences. Disease- and sex-specific proteomic profiles provide insight into cardiac remodeling in patients with heart valve disease and might help improve the understanding of molecular mechanisms and the development of individualized treatment strategies
Non-orographic gravity waves and turbulence caused by merging jet streams
Jet streams are important sources of non-orographic internal gravity waves and clear air turbulence (CAT). We analyze non-orographic gravity waves and CAT during a merger of the polar front jet stream (PFJ) with the subtropical jet stream (STJ) above the southern Atlantic. Thereby, we use a novel combination of airborne observations covering the meso-scale and turbulent scale in combination with high-resolution deterministic short-term forecasts. Coherent phase lines of temperature perturbations by gravity waves stretching along a highly sheared tropopause fold are simulated by the ECMWF IFS (integrated forecast system) forecasts. During the merging event, the PFJ reverses its direction from approximately antiparallel to parallel with respect to the STJ, going along with strong wind shear and horizontal deformation. Temperature perturbations in limb-imaging and lidar observations onboard the research aircraft HALO during the SouthTRAC campaign show remarkable agreement with the IFS data. Ten hours earlier, the IFS data show an âX-shapedâ pattern in the temperature perturbations emanating from the sheared tropopause fold. Tendencies of the IFS wind components show that these gravity waves are excited by spontaneous emission adjusting the strongly divergent flow when the PFJ impinges the STJ. In situ observations of temperature and wind components at 100 Hz confirm upward propagation of the probed portion of the gravity waves. They furthermore reveal embedded episodes of light-to-moderate CAT, Kelvin Helmholtz waves, and indications for partial wave reflection. Patches of low Richardson numbers in the IFS data coincide with the CAT observations, suggesting that this event was accessible to turbulence forecasting
- âŠ