julilili42/papers huggingface dataset:
Reprogramming of plant cells by filamentous plant‐colonizing microbes
2014-07-24

Summary Although phylogenetically unrelated, filamentous oomycetes and fungi establish similar structures to colonize plants and they represent economically the most important microbial threat to crop production. In mutualistic interactions established by root‐colonizing fungi, clear differences to pathogens can be seen, but there is mounting evidence that their infection strategies and molecular interactions have certain common features. To infect the host, fungi and oomycetes employ similar strategies to circumvent plant innate immunity. This process involves the suppression of basal defence responses which are triggered by the perception of conserved molecular patterns. To establish biotrophy, effector proteins are secreted from mutualistic and pathogenic microbes to the host tissue, where they play central roles in the modulation of host immunity and metabolic reprogramming of colonized host tissues. This review article discusses key effector mechanisms of filamentous pathogens and mutualists, how they modulate their host targets and the fundamental differences or parallels between these different interactions. The orchestration of effector actions during plant infection and the importance of their localization within host tissues are also discussed.
Studies on European species of the water mite family Aturidae Thor (Acari: Hydrachnidia)
2014-07-24

Selected water mite species of the family Aturidae are revised. The following synonyms are established: Aturus intermedius serrata K. Viets, 1922 = A. asserculatus Walter, 1906; A. lelgioensis Rensburg, 1971 = A. natangensis Protz, 1900; A. oudemansi Besseling, 1932 = A. intermedius Protz, 1900. The proposal of E. Angelier (1965), to synonymize A. paucisetus Motaş &amp; Tanasachi, 1946 with A. brachypus K. Viets, 1934 is rejected. Aturus elongatus Walter, 1927 (described after females, type material heavily damaged) and Ljania bipapillata subterranea Schwoerbel, 1964 (no type material available, no type locality defined) are considered as species incertae. Ljania macilenta longissima Schwoerbel, 1962 is redescribed and elevated to species rank. Two species of the genus Kongsbergia are described as new to science from interstitial habitats in the Central Mediterranean: K. albanorum sp. nov. from Western Sicily and K. jaentschi sp. nov. from Sicily and Sardinia. Woolastookia basilicalabrica sp. nov. is described from mountain streams in Southern Italy. Numerous new records are given, extending noteworthy the known distribution area of several species in Southern Europe. Aturus rotundus Romijn, 1921, Kongsbergia dentata Walter, 1947 and K. simillima K. Viets, 1949 are recorded for the first time from Italy, K. pectinigera Motaş &amp; Tanasachi, 1946 from France and Italy; first records from Corsica are given for Aturus intermedius and A. spatulifer Piersig, 1904. Lectotypes are designated for Aturus asserculatus Walter, 1906; A. asserculatus serratus K. Viets, 1922; A. oudemansi Besseling, 1932.
Glucocorticoids Induce Gastroparesis in Mice Through Depletion of l-Arginine
2014-07-24

Abstract Glucocorticoids (GCs) constitute a highly pleiotropic class of drugs predominantly employed in the treatment of inflammatory diseases. In our search for new mechanisms of action, we identified a hitherto unknown effect of GCs in the gastrointestinal tract. We found that oral administration of dexamethasone (Dex) to mice caused an enlargement of the stomach due to the induction of gastroparesis and that this effect was abolished in GRdim mice carrying the A458T mutation in the GC receptor (GR). Gastroparesis was unrelated to the enhanced gastric acid secretion observed after Dex treatment, although both effects were mediated by the same molecular mechanism of the GR. Using conditional GR-knockout mice, we could further rule out that GC effects on enterocytes or myeloid cells were involved in the induction of gastroparesis. In contrast, we found that Dex upregulated arginase 2 (Arg2) in the stomach both at the mRNA and protein level. This suggests that GC treatment leads to a depletion of l-arginine thereby impeding the production of nitric oxide (NO), which is required for gastric motility. We tested this hypothesis by supplementing the drinking water of the mice with exogenous l-arginine to compensate for the presumed shortage of this major substrate of NO synthases. Importantly, this measure completely prevented both the enlargement of the stomach and the induction of gastroparesis after Dex treatment. Our findings raise considerations of combining orally applied GCs with l-arginine to improve tolerability of GC treatment and provide a possible explanation for the antiemetic effects of GCs widely exploited in chemotherapy.
The Cryogenic AntiCoincidence detector for ATHENA: the progress towards the final pixel design
2014-07-24

"The Hot and Energetic Universe" is the scientific theme approved by the ESA SPC for a Large mission to be flown in the next ESA slot (2028th) timeframe. ATHENA is a space mission proposal tailored on this scientific theme. It will be the first X-ray mission able to perform the so-called "Integral field spectroscopy", by coupling a high-resolution spectrometer, the X-ray Integral Field Unit (X-IFU), to a high performance optics so providing detailed images of its field of view (5' in diameter) with an angular resolution of 5" and fine energy-spectra (2.5eV@E&lt;7keV). The X-IFU is a kilo-pixel array based on TES (Transition Edge Sensor) microcalorimeters providing high resolution spectroscopy in the 0.2-12 keV range. Some goals is the detection of faint and diffuse sources as Warm Hot Intergalactic Medium (WHIM) or galaxies outskirts. To reach its challenging scientific aims, it is necessary to shield efficiently the X-IFU instrument against background induced by external particles: the goal is 0.005 cts/cm2/s/keV. This scientific requirement can be met by using an active Cryogenic AntiCoincidence (CryoAC) detector placed very close to X-IFU (â1⁄4 1 mm below). This is shown by our GEANT4 simulation of the expected background at L2 orbit. The CryoAC is a TES based detector as the X-IFU sharing with it thermal and mechanical interfaces, so increasing the Technology Readiness Level (TRL) of the payload. It is a 2x2 array of microcalorimeter detectors made by Silicon absorber (each of about 80 mm2 and 300 Î1⁄4m thick) and sensed by an Ir TES. This choice shows that it is possible to operate such a detector in the so-called athermal regime which gives a response faster than the X-IFU (&lt; 30 Î1⁄4s), and low energy threshold (above few keV). Our consortium has developed and tested several samples, some of these also featured by the presence of Al-fins to efficiently collect the athermal phonons, and increased x-ray absorber area (up to 1 cm2). Here the results of deep test related to one of the last sample produced (namely AC-S5), and steps to reach the final detector design will be discussed.
Background simulations for the ATHENA X-IFU instrument: impact on the instrumental design
2014-07-24

On 28 november 2013 ESA selected "The Hot and Energetic Universe" as the scientific theme for a large mission to be flown in 2028 in the second lagrangian point, and ATHENA is the mission that will address this science topic. It will carry on board the X-ray Integral Field Unit (X-IFU), a 3840 pixel array based on TES (Transition Edge Sensor) microcalorimeters providing high resolution spectroscopy (2.5 eV @ 6 keV) in the 0.3-12 keV range. Among X-IFU goals there is the detection and characterization of high redshift AGNs, Clusters of galaxies and their outskirts, and the elusive Warm Hot Intergalactic Medium (WHIM), so great care must be paid to the reduction of the background level. These scientific objectives will be reached if the particle background is kept lower than 0.05 cts cm<sup>−2</sup> s<sup>−1</sup>, and to this aim, it is mandatory the use of a Cryogenic AC (CryoAC), as well as an optimized design of the cryostat and of the structures surrounding X-IFU. Our team, that is responsible for the ACD design, performed a detailed study to predict the rejection efficiency of the ACD as a function of its geometrical parameters and design choices. Since no experimental data on the background experienced by X-Ray microcalorimeters in the L2 orbit are available at the moment, the particle background levels have been calculated by means of Monte Carlo simulations using the Geant4 software.
The large area detector of LOFT: the Large Observatory for X-ray Timing
2014-07-24

LOFT (Large Observatory for X-ray Timing) is one of the five candidates that were considered by ESA as an M3 mission (with launch in 2022-2024) and has been studied during an extensive assessment phase. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. Its pointed instrument is the Large Area Detector (LAD), a 10 m 2 -class instrument operating in the 2-30keV range, which holds the capability to revolutionise studies of variability from X-ray sources on the millisecond time scales. The LAD instrument has now completed the assessment phase but was not down-selected for launch. However, during the assessment, most of the trade-offs have been closed leading to a robust and well documented design that will be re- proposed in future ESA calls. In this talk, we will summarize the characteristics of the LAD design and give an overview of the expectations for the instrument capabilities.
Radiation tests of the silicon drift detectors for LOFT
2014-07-24

During the three years long assessment phase of the LOFT mission, candidate\\nto the M3 launch opportunity of the ESA Cosmic Vision programme, we estimated\\nand measured the radiation damage of the silicon drift detectors (SDDs) of the\\nsatellite instrumentation. In particular, we irradiated the detectors with\\nprotons (of 0.8 and 11 MeV energy) to study the increment of leakage current\\nand the variation of the charge collection efficiency produced by the\\ndisplacement damage, and we "bombarded" the detectors with hypervelocity dust\\ngrains to measure the effect of the debris impacts. In this paper we describe\\nthe measurements and discuss the results in the context of the LOFT mission.\\n
An introduction to the IAAT ultraviolet MCP detector development
2014-07-24

Observations of ultraviolet light is the key to understand high temperature processes in the universe like hot plasma, accretion processes or illuminated protoplanetary discs around UV sources. Furthermore these observation contribute to major cosmological questions, like the distribution of baryonic matter or the formation of the milky way, as pointed out by Gomez de Castro et al.<SUP>1</SUP> Driven by the idea to participate in the Russian World Space Observatory we started to develop a position sensitive micro channel plate detector (MCP) for spectroscopy in the range of 160nm to 300 nm. Although we are not part of this project we still build a MCP detector prototype. In this paper we will present the general design of the detector and mainly focus on the aspect of our photocathode, while the electronics will be explained in more detail in the paper Characterisation of low power readout electronics for a UV microchannel plate detector with cross-strip readout" (Paper number 9144-116) by Marc Pfeifer.
Characterisation of low power readout electronics for a UV microchannel plate detector with cross-strip readout
2014-07-24

Astronomical observations in the ultraviolet (UV) wavelength range between 91 and 300nm are fundamental for the progress in astrophysics. Scientific success of future UV observatories raises the need for technology development in the areas of detectors, optical components, and their coatings. We develop solar blind and photon counting microchannel plate (MCP) UV detectors as a contribution to the progress in UV observation technology. New combinations of materials for the photocathode (see paper No. 9144-111, this volume, for details) as well as a cross-strip (XS) anode, having 64 strips on each layer, are used. Pre-amplification of the charge deposited onto the anode is performed by the Beetle chip designed at the Max-Planck-Institute for Nuclear Physics in Heidelberg for LHCb at CERN. It features 128 pre-amplifiers on one die and provides the analogue output in a four-fold serial stream. This stream is digitised by only four ADCs and is processed in an FPGA. This concept results in a reduced power consumption well below 10W as well as a reduced volume, weight and complexity of the readout electronics compared to existing cross-strip readouts. We developed an electronics prototype assembly and a setup in a vacuum chamber that is similar to the configuration in the final detector. The setup in the chamber is used for the burn-in of the MCPs as well as for tests of the readout electronics prototype assembly incorporating realistic signals. In this paper, information on the XS anodes as well as on the hybrid PCB carrying the Beetle pre-amplifier chip is shown. Details on the readout electronics design as well as details of the setup in the vacuum chamber are presented. An outlook to the next steps in the development process is given.
Analysis of proton propagation through the eROSITA telescope
2014-07-24

The German telescope eROSITA will be the first X-ray instrument orbiting around the L-2 lagrangian point. Therefore, modelling the radiation environment in that region of space and its interaction with the instrument is particularly important, as no measured data of other X-ray detectors can be used as a reference to predict how the space conditions will impact the instrumental capabilities. The orbit around L-2 extends well beyond the Earth ́s magnetosphere, where the flux of galactic cosmic particles is cut by the geomagnetic field, and fluxes of energetic particles one order of magnitude higher than in low Earth orbits are expected. Furthermore, as experienced by Chandra and XMM-Newton, softer protons may be scattered through the mirror shells and funneled to the focal plane, representing a potential additional source of background. To investigate and assess this component we are developing a ray tracing simulator for protons, that follows the track of each proton from the entrance pupil down to the focal plane. As a first step of analysis, we report here the estimate of the proton reflection efficiency for the eROSITA mirror shells obtained using a dataset of reflectivity parameters for Gold based on TRIM simulations.
Hyper-velocity impact test and simulation of a double-wall shield concept for the Wide Field Monitor aboard LOFT
2014-07-24

The space mission LOFT (Large Observatory For X-ray Timing) was selected in\\n2011 by ESA as one of the candidates for the M3 launch opportunity. LOFT is\\nequipped with two instruments, the Large Area Detector (LAD) and the Wide Field\\nMonitor (WFM), based on Silicon Drift Detectors (SDDs). In orbit, they would be\\nexposed to hyper-velocity impacts by environmental dust particles, which might\\nalter the surface properties of the SDDs. In order to assess the risk posed by\\nthese events, we performed simulations in ESABASE2 and laboratory tests. Tests\\non SDD prototypes aimed at verifying to what extent the structural damages\\nproduced by impacts affect the SDD functionality have been performed at the Van\\nde Graaff dust accelerator at the Max Planck Institute for Nuclear Physics\\n(MPIK) in Heidelberg. For the WFM, where we expect a rate of risky impacts\\nnotably higher than for the LAD, we designed, simulated and successfully tested\\nat the plasma accelerator at the Technical University in Munich (TUM) a\\ndouble-wall shielding configuration based on thin foils of Kapton and\\nPolypropylene. In this paper we summarize all the assessment, focussing on the\\nexperimental test campaign at TUM.\\n
Background studies for ATHENA: towards a new assessment phase
2014-07-24

In view of the endorsement of ATHENA as the future large space mission to explore the Hot and Energetic Universe scientific theme recently selected by ESA, we summarize here some aspects of the interplanetary radiation environment that will require further investigation in the new phase of assessment studies of background and radiation damage for the ATHENA focal plane instrumentation.
A setup for soft proton scattering on x-ray mirrors
2014-07-24

Protons with energies between tens of keV and some MeV can degrade the performance of X-ray detectors and contribute to the instrument background. In-orbit measurements showed that the flux of soft protons funneled through Wolter-type mirrors is considerably larger than expected from simulations. Up to now, just very few results from laboratory experiments have been reported and the data is not sufficient to pinpoint the best analytical description of the physical process or to validate simulation codes. In order to improve this situation, a small angle scattering experiment to measure the proton reflection properties of X-ray mirrors has been set up at the accelerator facility of the University of Tübingen. The experimental setup and initial preliminary results obtained with samples of eROSITA mirror shells are presented.
Bumber filter against micrometeoroids for eROSITA
2014-07-24

The German X-ray telescope eROSITA will perform the first imaging all-sky survey in the medium energy range up to 10 keV with unprecedented spectral and angular resolution. The launch of eROSITA onboard of the Russian Spectrum- Röntgen-Gamma satellite into an orbit around the L-2 lagrangian point is foreseen in 2016. Even tough the L-2 space environment can be considered free of orbital debris, the presence of extraterrestrial meteoroids in the interplanetary space implies a certain hazard for the eROSITA pnCCDs, as experienced by both pn and MOS cameras onboard XMM-Newton. In this paper we address this question and investigate the response of the optical blocking filter to hypervelocity impacts.
ChemInform Abstract: Between Oxoborate and Nitridoborate: The Oxonitridoborate Oxide La3(OBN2)O2.
2014-07-24

Abstract The new title compound is prepared by solid state reaction of LaOCl and Li 3 (BN 2 ) in the molar ratio of 3:1 (sealed Nb ampoule in evacuated silica ampoule, 1200 °C, 12 h, heating and cooling rates of 2 °C/min).
Comparison of Hydrogen Elimination from Molecular Zinc and Magnesium Hydride Clusters
2014-07-25

Abstract In analogy to the previously reported tetranuclear magnesium hydride cluster with a bridged dianionic bis‐β‐diketiminate ligand, a related zinc hydride cluster has been prepared. The crystal structures of these magnesium and zinc hydride complexes are similar: the metal atoms are situated at the corners of a tetrahedron in which the vertices are bridged either by dianionic bis‐β‐diketiminate ligands or hydride ions. Both structures are retained in solution and show examples of H − ⋅⋅⋅H − NMR coupling (Mg: 8.5 Hz; Zn: 16.0 Hz). The zinc hydride cluster [ NN ‐(ZnH) 2 ] 2 thermally decomposes at 90 °C and releases 1.8 equivalents of H 2 . In contrast to magnesium hydride clusters, there is no apparent relationship between cluster size and thermal decomposition temperature for the zinc hydrides. DFT calculations reproduced the structure of the zinc hydride cluster reasonably well and charge density analysis showed no bond paths between the hydride ions. This contrasts with calculations on the analogous magnesium hydride cluster in which a counter‐intuitive H − ⋅⋅⋅H − bond path was observed. Forcing a reduced H − ⋅⋅⋅H − distance in the zinc hydride cluster, however, gave rise to a H − ⋅⋅⋅H − bond path. Such weak interactions could play a role in H 2 desorption. The presumed molecular product after H 2 release, a Zn(I) cluster, could not be characterized experimentally but DFT calculations predicted a cluster with two localized ZnZn bonds.
The microchannel x-ray telescope for the gamma-ray burst mission SVOM
2014-07-25

We present the Microchannel X-ray Telescope, a new light and compact focussing telescope that will be ying on the Sino-French SVOM mission dedicated to Gamma-Ray Burst science. The MXT design is based on the coupling of square pore micro-channel plates with a low noise pnCCD. MXT will provide an effective area of about 50 cm2, and its point spread function is expected to be better than 3.7 arc min (FWHM) on axis. The estimated sensitivity is adequate to detect all the afterglows of the SVOM GRBs, and to localize them to better then 60 arc sec after five minutes of observation. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Role of γ ‐aminobutyric acid signalling in the attenuation of counter‐regulatory hormonal responses after antecedent hypoglycaemia in healthy men
2014-07-25

The attenuated counter‐regulatory response to hypoglycaemia after antecedent hypoglycaemic episodes has been observed in animals to be associated with an increase in γ ‐aminobutyric acid ( GABA ) signalling. We therefore tested the hypothesis that the pharmacological suppression of GABAergic activity during a repeated hypoglycaemic episode enhances counter‐regulatory responses. Fourteen healthy men participated in two experimental sessions each comprising three insulin‐induced hypoglycaemic episodes. Before the third hypoglycaemic episode, participants received the GABA ‐antagonistic drug modafinil (200 mg orally) and placebo, respectively. In the placebo condition, the secretion of norepinephrine, adrenocorticotropic hormone, cortisol and growth hormone, and the perception of neuroglycopenic symptoms were attenuated during the third as compared with the first hypoglycaemic episode (each p &lt; 0.05). Modafinil reversed this effect for the noradrenergic response (p &lt; 0.05), while not significantly altering the attenuation of other hormonal responses and symptom perception (p &gt; 0.3). Our findings indicate that increased GABAergic transmission could contribute to aspects of the attenuated counter‐regulatory response after recurrent hypoglycaemia in humans.