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Germanium as key dopant to boost the catalytic performance of small platinum clusters for alkane dehydrogenation
Dynamical Ne K Edge and Line Variations in the X-Ray Spectrum of the Ultra-compact Binary 4U 0614+091
We observed the ultra-compact binary candidate 4U 0614+091 for a total of 200
ksec with the high-energy transmission gratings onboard the \chandra X-ray
Observatory. The source is found at various intensity levels with spectral
variations present. X-ray luminosities vary between 2.0 \ergsec
and 3.5 \ergsec. Continuum variations are present at all times
and spectra can be well fit with a powerlaw component, a high kT blackbody
component, and a broad line component near oxygen. The spectra require
adjustments to the Ne K edge and in some occasions also to the Mg K edge. The
Ne K edge appears variable in terms of optical depths and morphology. The edge
reveals average blue- and red-shifted values implying Doppler velocities of the
order of 3500 \kms. The data show that Ne K exhibits excess column densities of
up to several 10 cm. The variability proves that the excess is
intrinsic to the source. The correponding disk velocities also imply an outer
disk radius of the order of cm consistent with an ultra-compact binary
nature. We also detect a prominent soft emission line complex near the \oviii
L position which appears extremely broad and relativistic effects from
near the innermost disk have to be included. Gravitationally broadened line
fits also provide nearly edge-on angles of inclination between 86 and
89. The emissions appear consistent with an ionized disk with
ionization parameters of the order of 10 at radii of a few 10 cm. The
line wavelengths with respect to \oviiia\ are found variably blue-shifted
indicating more complex inner disk dynamics.Comment: 24 pages, 8 figures, submitted to the Astrophyscial Main Journa
A synthetic human Agouti-related protein-(83–132)-NH2 fragment is a potent inhibitor of melanocortin receptor function
AbstractChemical synthesis of Agouti proteins – Agouti and Agouti-related proteins – is complicated by their large size and by multiple cysteine residues located in the carboxyl terminal regions. Three human Agouti-related protein (AGRP) fragments, two of which correspond to a proposed endoprotease cleavage site between amino acids 82 and 83, were synthesized and tested for anti-melanotropic activity using Xenopus laevis dermal melanophores. Amino-terminal fragments AGRP(25–51) and (54–82) were devoid of significant antagonist activity, whereas the amidated carboxyl-terminal AGRP fragment (83–132)-NH2 was potently active with an inhibitory equilibrium dissociation constant (Ki) of 0.7 nM. The ability to synthesize functionally active AGRP should help unravel its role in the central nervous system and its unusual properties with respect to interaction with the melanocortin family of G-protein coupled receptors
Enterobiliary Fistula as a Complication of Eosinophilic Gastroenteritis: a Case Report
Eosinophilic gasteroenteritis is an uncommon disease with variable clinical features characterized by eosinophilic infiltration. Clinical manifestations range from non-specific gastrointestinal complaints such as nausea, vomiting, crampy abdominal pain, and diarrhea to specific findings such as malabsorption, protein loosing enteropathy, luminal obstruction, eosinophilic ascites and effusion. We report here on a case of eosinophilic gastroenteritis causing enterobiliary fistula which is an extremely unusual complication
Phase-resolved optical and X-ray spectroscopy of low-mass X-ray binary X1822-371
(Abridged) X1822-371 is the prototypical accretion disc corona X-ray source,
a low-mass X-ray binary viewed at very high inclination, thereby allowing the
disc structure and extended disc coronal regions to be visible. We study the
structure of the accretion disc in X1822-371 by modelling the phase-resolved
spectra both in optical and X-ray regime. We analyse high time resolution
optical ESO/VLT spectra of X1822-371 to study the variability in the emission
line profiles. In addition, we use data from XMM-Newton space observatory to
study phase-resolved as well as high resolution X-ray spectra. We apply the
Doppler tomography technique to reconstruct a map of the optical emission
distribution in the system. We fit multi-component models to the X-ray spectra.
We find that our results from both the optical and X-ray analysis can be
explained with a model where the accretion disc has a thick rim in the region
where the accretion stream impacts the disc. The behaviour of the H_beta line
complex implies that some of the accreting matter creates an outburst around
the accretion stream impact location and that the resulting outflow of matter
moves both away from the accretion disc and towards the centre of the disc.
Such behaviour can be explained by an almost isotropic outflow of matter from
the accretion stream impact region. The optical emission lines of HeII 4686 and
5411 show double peaked profiles, typical for an accretion disc at high
inclination. However, their velocities are slower than expected for an
accretion disc in a system like X1822-371. This, combined with the fact that
the HeII emission lines do not get eclipsed during the partial eclipse in the
continuum, suggests that the line emission does not originate in the orbital
plane and is more likely to come from above the accretion disc, for example the
accretion disc wind.Comment: 10 pages, 13 figures, accepted for publication in A&
Granulosa Cell Tumor of Scrotal Tunics: A Case Report
We report a case of adult granulosa cell tumor arising in the scrotal tunics. The patient was a 34-year-old man who presented with right scrotal swelling, first noticed four months previously. Under the initial clinical impression of epididymoorchitis, antibiotic treatment was instituted but there was no response. The paratesticular nodules revealed by ultrasound and magnetic resonance imaging mimicked intratesticular lesion, and radical orchiectomy was performed. Although several cases of adult testicular granulosa cell tumor, have been reported, the occurrence of this entity in the paratesticular area has not, as far as we are aware, been previously described
3D-vision based detection, localization, and sizing of broccoli heads in the field
This paper describes a 3D vision system for robotic harvesting of broccoli using low-cost RGB-D sensors, which was developed and evaluated using sensory data collected under real-world field conditions in both the UK and Spain. The presented method addresses the tasks of detecting mature broccoli heads in the field and providing their 3D locations relative to the vehicle. The paper evaluates different 3D features, machine learning, and temporal filtering methods for detection of broccoli heads. Our experiments show that a combination of Viewpoint Feature Histograms, Support Vector Machine classifier, and a temporal filter to track the detected heads results in a system that detects broccoli heads with high precision. We also show that the temporal filtering can be used to generate a 3D map of the broccoli head positions in the field. Additionally, we present methods for automatically estimating the size of the broccoli heads, to determine when a head is ready for harvest. All of the methods were evaluated using ground-truth data from both the UK and Spain, which we also make available to the research community for subsequent algorithm development and result comparison. Cross-validation of the system trained on the UK dataset on the Spanish dataset, and vice versa, indicated good generalization capabilities of the system, confirming the strong potential of low-cost 3D imaging for commercial broccoli harvesting
Experimental analysis of the effect of local base blowing on three-dimensional wake modes
Wake modes of a three-dimensional blunt-based body near a wall are investigated at a Reynolds number . The targeted modes are the static symmetry-breaking mode and two antisymmetric periodic modes. The static mode orientation is aligned with the horizontal major -axis of the base and randomly switches between a positive and a negative state leading to long-time bistable dynamics of the turbulent wake. The modifications of these modes are studied when continuous blowing is applied at different locations through four slits along the base edges (denoted L for left, R for right, T for top and B for bottom) in either four single asymmetric configurations or two double symmetric configurations (denoted LR and TB). Two regimes, referred to as mass and momentum, are clearly identifiable for all configurations. The mass regime, which is fairly insensitive to blowing momentum and location, is characterized by the growth of the recirculating bubble as the total injected flow rate is increased, and is associated with a base drag reduction and interpreted as resulting from the equilibrium between mass fluxes feeding and emptying the recirculating region. A simple budget model is shown to be in agreement with entrainment velocities measured for isolated turbulent mixing layers. The strength of the static mode is reduced up to 20 % when the bubble length is maximum, whereas no change in the periodic mode frequencies is found. On the other hand, the momentum regime is characterized by the deflating of the recirculating bubble, leading to base drag increase, and it is interpreted by the free shear layer forcing, which increases the entrainment velocity, thus emptying the recirculating bubble. In this regime the static mode orientation is imposed by the blowing symmetry. Lateral L and R (respectively top/bottom T and B) blowing configurations select or states in the horizontal (respectively vertical) direction, while bistable dynamics persists for the symmetric LR and TB configurations. The shape of periodic modes follows the changes in wake static orientation. The transition between the two regimes is governed by both the total injected flow rate and the location of the injection
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