280 research outputs found
Compact Patch Antenna for Automatic Identification System (AIS)
International audienceThis paper presents a radiating element developed for the space AIS application. This element is a compact sized and reduced mass microstrip patch antenna integrating frequency resonant adjustment devices. Theoretical and experimental results with good agreement are presented
Slc2a10 knock-out mice deficient in ascorbic acid synthesis recapitulate aspects of arterial tortuosity syndrome and display mitochondrial respiration defects
Arterial tortuosity syndrome (ATS) is a recessively inherited connective tissue disorder, mainly characterized by tortuosity and aneurysm formation of the major arteries. ATS is caused by loss-of-function mutations in SLC2A10, encoding the facilitative glucose transporter GLUT10. Former studies implicated GLUT10 in the transport of dehydroascorbic acid, the oxidized form of ascorbic acid (AA). Mouse models carrying homozygous Slc2a10 missense mutations did not recapitulate the human phenotype. Since mice, in contrast to humans, are able to intracellularly synthesize AA, we generated a novel ATS mouse model, deficient for Slc2a10 as well as Gulo, which encodes for L-gulonolactone oxidase, an enzyme catalyzing the final step in AA biosynthesis in mouse. Gulo;Slc2a10 double knock-out mice showed mild phenotypic anomalies, which were absent in single knock-out controls. While Gulo;Slc2a10 double knock-out mice did not fully phenocopy human ATS, histological and immunocytochemical analysis revealed compromised extracellular matrix formation. Transforming growth factor beta signaling remained unaltered, while mitochondrial function was compromised in smooth muscle cells derived from Gulo;Slc2a10 double knock-out mice. Altogether, our data add evidence that ATS is an ascorbate compartmentalization disorder, but additional factors underlying the observed phenotype in humans remain to be determined
Identification of noncompliant glaucoma patients using Bayesian networks and the Eye-Drop Satisfaction Questionnaire
Bathymetric Artifacts in Sea Beam Data: How to Recognize Them and What Causes Them
Sea Beam multibeam bathymetric data have greatly advanced understanding of the deep seafloor. However, several types of bathymetric artifacts have been identified in Sea Beam\u27s contoured output. Surveys with many overlapping swaths and digital recording on magnetic tape of Sea Beam\u27s 16 acoustic returns made it possible to evaluate actual system performance. The artifacts are not due to the contouring algorithm used. Rather, they result from errors in echo detection and processing. These errors are due to internal factors such as side lobe interference, bottom-tracking gate malfunctions, or external interference from other sound sources (e.g., 3.5 kHz echo sounders or seismic sound sources). Although many artifacts are obviously spurious and would be disregarded, some (particularly the omega effects described in this paper) are more subtle and could mislead the unwary observer. Artifacts observed could be mistaken for volcanic constructs, abyssal hill trends, hydrothermal mounds, slump blocks, or channels and could seriously affect volcanic, tectonic, or sedimentological interpretations. Misinterpretation of these artifacts may result in positioning errors when seafloor bathymetry is used to navigate the ship. Considering these possible geological misinterpretations, a clear understanding of the Sea Beam system\u27s capabilities and limitations is deemed essential
Jet-flap installation noise of pylon mounted jet engine on 3D wing
The cost of experimental testing allows to focus only on a finite number of operations for installation noise. How can other operations be interpolated in between test conditions? How can test points with partially poor signal to noise ratio be repaired? How is it possible to extrapolate to and cross-compare with a known test point which is out of scope for the current test facility, but has been measured before in another wind tunnel? All of the above can be attempted with the knowledge of the problem-specific physics, which is among others represented in terms of velocity scaling laws. Hence, a major contribution presented in this paper is the analytical derivation of an analogy for the far-field noise of installed flight jets and a cross-check with experimental data from the DJINN AWB test. This analogy is a specific solution of Ffowcs-Williams-Hawking's and Curle's analogies for fixed objects which experience unsteady flow fluctuations on their surfaces. The analysis shows that velocity scaling exponents are qualitatively different depending on directivity, mainly between forward and rear arc. The experimentally acquired isolated flight jet noise data scales with I~(ΔU)⁶Uc² in the forward arc and with I~(ΔU)⁸ in the rear arc. Installed flight jets are dominated by loading noise I~(ΔU)⁶ in the forward arc, and are otherwise very similar to jet noise, i.e. in the rear arc they scale with I~(ΔU)⁸. The transition of velocity scaling coefficients between forward arc and rear arc are extracted by a study over 47 flyover microphones using various operations of either same shear layer difference velocity or same shear layer convection velocity. The exponents can also be used to improve the prediction of extrapolating to out-of-scope wind tunnel velocities
Improving tuberculosis surveillance by detecting international transmission using publicly available whole genome sequencing data
Improving the surveillance of tuberculosis (TB) is one of the eight core activities identified by the World Health Organization (WHO) and the European Respiratory Society to achieve TB elimination, defined as less than one incident case per million [1]. Monitoring transmission is especially important for multidrug-resistant (MDR) Mycobacterium tuberculosis isolates – defined as being resistant to rifampicin and isoniazid – and for extensively drug-resistant (XDR) M. tuberculosis isolates – defined as MDR isolates with additional resistance to at least one of the fluoroquinolones and at least one of the second-line injectable drugs. In 2017, the WHO estimated that worldwide more than 450,000 people fell ill with MDR-TB and among these, more than 38,000 fell ill with XDR-TB [2].
The rapid advance in molecular typing technology – especially the availability of whole genome sequencing (WGS) to identify and characterise pathogens – gives us the chance to integrate this information into disease surveillance. For TB surveillance, it is possible to combine the results of molecular typing of isolates from the M. tuberculosis complex with traditional epidemiological information to infer or to exclude TB transmission [3,4]. This is of particular relevance if transmission occurs among multiple countries, where epidemiological data such as social contacts are more difficult to get and where data exchange is more difficult to organise. The European Centre for Disease Prevention and Control (ECDC) reported 44 events of international transmission (international clusters) of MDR-TB in different European countries between 2012 and 2015 [5]. In that report, the authors inferred TB transmission using the mycobacterial interspersed repetitive units variable number of tandem repeats (MIRU-VNTR) typing method. However, this method has limitations such as low correlation with epidemiological information in outbreak settings and low discriminatory power [3,6]. In comparison, WGS analysis offers a much higher discriminatory power and allows inferring (or excluding) TB transmission at a higher resolution [4]. In a recent systematic review, van der Werf et al. identified three studies that used WGS to investigate the international transmission of TB [7].
In recent years, the amount of available WGS data is increasing, especially because sequencing has become cheaper [8]. In addition, more and more authors deposit the raw data of their projects in open access public repositories such as the Sequence Read Archive (SRA) of the National Center for Biotechnology Information (NCBI) [9]. These publicly available raw WGS data for thousands of isolates enable the re-use and the additional analyses at a large and global scale [10]. For example, it is possible to compare genomic data among different studies or countries since the data are available in a single place. Moreover, new software tools can be tested using the same raw WGS data [11]. However, standards in bioinformatics analysis and interpretation of these WGS data for surveillance purposes are not yet fully established [12].
We aimed to assess the usefulness of raw WGS data of global MDR/XDR M. tuberculosis isolates available in public repositories to improve TB surveillance. Specifically, we wanted to identify potential international events of TB transmission and to compare the international isolates with a collection of M. tuberculosis isolates collected in Germany in 2012 and 2013.Peer Reviewe
Exciton-exciton interaction beyond the hydrogenic picture in a MoSe monolayer in the strong light-matter coupling regime
In transition metal dichalcogenides layers of atomic scale thickness, the
electron-hole Coulomb interaction potential is strongly influenced by the sharp
discontinuity of the dielectric function across the layer plane. This feature
results in peculiar non-hydrogenic excitonic states, in which exciton-mediated
optical nonlinearities are predicted to be enhanced as compared to their
hydrogenic counterpart. To demonstrate this enhancement, we performed optical
transmission spectroscopy of a MoSe monolayer placed in the strong coupling
regime with the mode of an optical microcavity, and analyzed the results
quantitatively with a nonlinear input-output theory. We find an enhancement of
both the exciton-exciton interaction and of the excitonic fermionic saturation
with respect to realistic values expected in the hydrogenic picture. Such
results demonstrate that unconventional excitons in MoSe are highly
favourable for the implementation of large exciton-mediated optical
nonlinearities, potentially working up to room temperature
Programming of Dopaminergic Neurons by Early Exposure to Sex Hormones: Effects on Morphine-Induced Accumbens Dopamine Release, Reward, and Locomotor Behavior in Male and Female Rats
Neonatal programming with sex hormones produces long-term functional changes in various tissues, including the brain. Previously, we demonstrated a higher content of dopamine and an increase in potassium-induced dopamine release in the nucleus accumbens of adult rats exposed to estradiol valerate. On the other hand, sex hormones also affect the opioid system increasing the expression of the μ opioid receptor and β-endorphins. Here, we investigated if neonatal programming with sex hormones alters the response to morphine during adulthood in rats and predispose them to neurochemical, rewarding and behavioral activating effects. We examined the effects of neonatal exposure to a single dose of estradiol valerate or testosterone propionate on morphine-induced (5 mg/kg, i.v.) dopamine release in the nucleus accumbens and morphine-induced (3 mg/kg, s.c.) locomotor activity and conditioned place preference when these rats were adults. Our results showed a significant increase in morphine-induced dopamine release in the nucleus accumbens of rats that were exposed neonatally to estradiol compared with control rats. This effect was correlated with higher place preference and locomotor activity induced by morphine in adult rats neonatally exposed to estradiol valerate. However, the effect of morphine on dopamine release and behaviors was similar in rats treated with testosterone compared to control rats. Additionally, the expression of mu (μ) opioid receptor, dopamine receptor type 1 (D1) and dopamine receptor type 2 (D2) in the nucleus accumbens of adult rats was not different after treatment with sex hormones. Taken together, our results demonstrated an enhancement of pharmacological effects produced by morphine in rats neonatally programmed with estradiol valerate, suggesting that early exposure to sex hormones could represent a vulnerability factor in the development of addiction to opioid drugs such as morphine and heroin in adulthood
Analogues of antifungal tjipanazoles from rebeccamycin
Analogues of antifungal tjipanazoles were obtained by semi-synthesis from rebeccamycin, an antitumor antibiotic isolated from cultures of Saccharothrix aerocolonigenes. The antiproliferative activities of the new compounds were evaluated in vitro against nine tumor cell lines. The effect on the cell cycle of murine leukemia L1210 cells was examined and the antimicrobial activities against two Gram positive bacteria, a Gram negative bacterium and a yeast were determined. The inhibitory properties toward four kinases and toward topoisomerase I were evaluated. The most cytotoxic compound in the series was a dinitro derivative characterized as a potent topoisomerase I inhibito
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