146 research outputs found
Evaluation des Einflusses primärer normaler und tumorassoziierter Fibroblasten auf Wachstum und Differenzierung humaner Mammakarzinomzellen
Bei der Tumorprogression des Mammakarzinoms spielen nicht nur die Tumorzellen selbst, sondern auch das umgebende Stroma eine wichtige Rolle. Durch ein verhärtetes Tumorstroma können reguläre interzelluläre und mechanische Prozesse gestört werden, so dass ein kanzerogenes Wachstum von Mammakarzinomzellen begünstigt wird. In unserer Arbeitsgemeinschaft konnte kürzlich bewiesen werden, dass sich durch frei schwimmende Kollagenmatrizen die Reversion maligner Epithelzellen (T4-2-Zellen) in Cokultur mit humanen Mammafibroblasten (HMF) beobachten ließ. Die Reversion von T4-2-Zellen, in einem 3D Zellkulturmodell, wird wesentlich durch die zwei Einflussfaktoren Matrixcompliance und Fibroblasten induziert. Die schwimmende Matrixbeschaffenheit ermöglicht sowohl NF als auch CAF durch Kontraktion die Matrixcompliance zu regulieren und dadurch das Wachstumsverhalten T4-2-Zellen zu verändern, so dass sich vermehrt polarisierte Azini bilden
Intervention effects on dietary intake among children by maternal education level: results of the Copenhagen School Child Intervention Study (CoSCIS)
Dietary intake among Danish children, in general, does not comply with the official recommendations. The objectives of the present study were to evaluate the 3-year effect of a multi-component school-based intervention on nutrient intake in children, and to examine whether an intervention effect depended on maternal education level. A total of 307 children (intervention group: n 184; comparison group: n 123) were included in the present study. All had information on dietary intake pre- and post-intervention (mean age 6·8 and 9·5 years for intervention and comparison groups, respectively) assessed by a 7-d food record. Analyses were conducted based on the daily intake of macronutrients (energy percentage (E%)), fatty acids (E%), added sugar (E%) and dietary fibre (g/d and g/MJ). Analyses were stratified by maternal education level into three categories. Changes in nutrient intake were observed in the intervention group, mainly among children of mothers with a short education ( < 10 years). Here, intake of dietary fibre increased (β = 2·1 g/d, 95 % CI 0·5, 3·6, P= 0·01). Intake of protein tended to increase (β = 0·6 E%, 95 % CI − 0·01, 1·2, P= 0·05), while intake of fat (β = − 1·7 E%, 95 % CI − 3·8, 0·3, P= 0·09) and SFA (β = − 0·9, 95 % CI − 2·0, 0·2, P= 0·10) tended to decrease. Also, a significant intervention effect was observed on the intake of SFA among children of mothers with a long education (β = − 0·8, 95 % CI − 1·5, − 0·03, P= 0·04). This multi-component school-based intervention resulted in changes in the dietary intake, particularly among children of mothers with a short education. As the dietary intake of this subgroup generally differs most from the recommendations, the results of the present study are particularly encouraging
Vector Competence of the Invasive Mosquito Species Aedes koreicus for Arboviruses and Interference with a Novel Insect Specific Virus
The global spread of invasive mosquito species increases arbovirus infections. In addition to the invasive species Aedes albopictus and Aedes japonicus, Aedes koreicus has spread within Central Europe. Extensive information on its vector competence is missing. Ae. koreicus from Germany were investigated for their vector competence for chikungunya virus (CHIKV), Zika virus (ZIKV) and West Nile virus (WNV). Experiments were performed under different climate conditions (27 ± 5 °C; 24 ± 5 °C) for fourteen days. Ae. koreicus had the potential to transmit CHIKV and ZIKV but not WNV. Transmission was exclusively observed at the higher temperature, and transmission efficiency was rather low, at 4.6% (CHIKV) or 4.7% (ZIKV). Using a whole virome analysis, a novel mosquito-associated virus, designated Wiesbaden virus (WBDV), was identified in Ae. koreicus. Linking the WBDV infection status of single specimens to their transmission capability for the arboviruses revealed no influence on ZIKV transmission. In contrast, a coinfection of WBDV and CHIKV likely has a boost effect on CHIKV transmission. Due to its current distribution, the risk of arbovirus transmission by Ae. koreicus in Europe is rather low but might gain importance, especially in regions with higher temperatures. The impact of WBDV on arbovirus transmission should be analyzed in more detail
Vector Competence of Northern European Culex pipiens Biotype pipiens and Culex torrentium to West Nile Virus and Sindbis Virus
The West Nile Virus (WNV) and Sindbis virus (SINV) are avian-hosted mosquito-borne zoonotic viruses that co-circulate in some geographical areas and share vector species such as Culex pipiens and Culex torrentium. These are widespread in Europe, including northern parts and Finland, where SINV is endemic, but WNV is currently not. As WNV is spreading northwards in Europe, we wanted to assess the experimental vector competence of Finnish Culex pipiens and Culex torrentium mosquitoes to WNV and SINV in different temperature profiles. Both mosquito species were found susceptible to both viruses and got infected via infectious blood meal at a mean temperature of 18 °C. WNV-positive saliva was detected at a mean temperature of 24 °C, whereas SINV-positive saliva was detected already at a mean temperature of 18 °C. Cx. torrentium was found to be a more efficient vector for WNV and SINV over Cx. pipiens. Overall, the results were in line with the previous studies performed with more southern vector populations. The current climate does not seem optimal for WNV circulation in Finland, but temporary summertime transmission could occur in the future if all other essential factors are in place. More field data would be needed for monitoring and understanding the northward spreading of WNV in Europe
Skalenhandbuch zur Dokumentation der Erhebungsinstrumente
Dies in eine aktualisierte Version von: https://doi.org/10.18452/3125 - Grund der Aktualisierung: In der FDZ-Version der Daten des IQB-LV 2012 wurde eine Änderung im Lehrkräftedatensatz vorgenommen. Die folgenden Variablen wurden hinzugefügt, um eine Replikation des Ergebnisberichts zu ermöglichen (Kapitel 12, Tabelle 12.1 und Tabelle 12.2): lalter_re, mathe_ind, bio_ind, che_ind, phy_ind. Dies wurde in der vorliegenden Version des SHB des LV 12 aktualisiert.Das Skalenhandbuch dokumentiert die Erhebungsinstrumente, die im IQB-Ländervergleich 2012 in der Sekundarstufe I eingesetzt wurden. Dies umfasst die Testinstrumente zur Erfassung der Kompetenzen in den Fächern Mathematik, Biologie, Chemie und Physik sowie die Fragebögen der Schüler*innen, der Lehrkräfte und der Schulleitungen. Der IQB-Ländervergleich dient einem systematischen Vergleich der Länder der Bundesrepublik Deutschland mit Blick auf die in den Bildungsstandards für die naturwissenschaftlichen Fächer und Mathematik beschriebenen Kompetenzen am Ende der Sekundarstufe I
Simulating image coaddition with the Nancy Grace Roman Space Telescope: I. Simulation methodology and general results
The upcoming Nancy Grace Roman Space Telescope will carry out a wide-area
survey in the near infrared. A key science objective is the measurement of
cosmic structure via weak gravitational lensing. Roman data will be
undersampled, which introduces new challenges in the measurement of source
galaxy shapes; a potential solution is to use linear algebra-based coaddition
techniques such as Imcom that combine multiple undersampled images to produce a
single oversampled output mosaic with a desired "target" point spread function
(PSF). We present here an initial application of Imcom to 0.64 square degrees
of simulated Roman data, based on the Roman branch of the Legacy Survey of
Space and Time (LSST) Dark Energy Science Collaboration (DESC) Data Challenge 2
(DC2) simulation. We show that Imcom runs successfully on simulated data that
includes features such as plate scale distortions, chip gaps, detector defects,
and cosmic ray masks. We simultaneously propagate grids of injected sources and
simulated noise fields as well as the full simulation. We quantify the residual
deviations of the PSF from the target (the "leakage"), as well as noise
properties of the output images; we discuss how the overall tiling pattern as
well as Moir\'e patterns appear in the final leakage and noise maps. We include
appendices on interpolation algorithms and the interaction of undersampling
with image processing operations that may be of broader applicability. The
companion paper ("Paper II") explores the implications for weak lensing
analyses.Comment: 28 pages, 19 figures, matches version accepted by MNRA
Simulating image coaddition with the Nancy Grace Roman Space Telescope: II. Analysis of the simulated images and implications for weak lensing
One challenge for applying current weak lensing analysis tools to the Nancy
Grace Roman Space Telescope is that individual images will be undersampled. Our
companion paper presented an initial application of Imcom - an algorithm that
builds an optimal mapping from input to output pixels to reconstruct a fully
sampled combined image - on the Roman image simulations. In this paper, we
measure the output noise power spectra, identify the sources of the major
features in the power spectra, and show that simple analytic models that ignore
sampling effects underestimate the power spectra of the coadded noise images.
We compute the moments of both idealized injected stars and fully simulated
stars in the coadded images, and their 1- and 2-point statistics. We show that
the idealized injected stars have root-mean-square ellipticity errors (1 - 6) x
10-4 per component depending on the band; the correlation functions are >= 2
orders of magnitude below requirements, indicating that the image combination
step itself is using a small fraction of the overall Roman 2nd moment error
budget, although the 4th moments are larger and warrant further investigation.
The stars in the simulated sky images, which include blending and chromaticity
effects, have correlation functions near the requirement level (and below the
requirement level in a wide-band image constructed by stacking all 4 filters).
We evaluate the noise-induced biases in the ellipticities of injected stars,
and explain the resulting trends with an analytical model. We conclude by
enumerating the next steps in developing an image coaddition pipeline for
Roman.Comment: 25 pages, 20 figures. Submitted to MNRA
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