Context.
Revealing the mechanisms shaping the architecture of planetary systems is crucial for our understanding of their formation and evolution. In this context, it has been recently proposed that ...stellar clustering might be the key in shaping the orbital architecture of exoplanets.
Aims.
The main goal of this work is to explore the factors that shape the orbits of planets.
Methods.
We performed different statistical tests to compare the properties of planets and their host stars associated with different stellar environments.
Results.
We used a homogeneous sample of relatively young FGK dwarf stars with radial velocity detected planets and tested the hypothesis that their association to phase space (position-velocity) over-densities (“cluster” stars) and under-densities (“field” stars) impacts the orbital periods of planets. When controlling for the host star properties on a sample of 52 planets orbiting around cluster stars and 15 planets orbiting around field stars, we found no significant difference in the period distribution of planets orbiting these two populations of stars. By considering an extended sample of 73 planets orbiting around cluster stars and 25 planets orbiting field stars, a significant difference in the planetary period distributions emerged. However, the hosts associated with stellar under-densities appeared to be significantly older than their cluster counterparts. This does not allow us to conclude as to whether the planetary architecture is related to age, environment, or both. We further studied a sample of planets orbiting cluster stars to study the mechanism responsible for the shaping of orbits of planets in similar environments. We could not identify a parameter that can unambiguously be responsible for the orbital architecture of massive planets, perhaps, indicating the complexity of the issue.
Conclusions.
An increased number of planets in clusters and in over-density environments will help to build large and unbiased samples which will then allow to better understand the dominant processes shaping the orbits of planets.
The MAGIC collaboration has studied the high peaked BL-Lac object 1ES1218+30.4 at a redshift z = 0.182, using the MAGIC imaging air Cherenkov telescope located on the Canary island of La Palma. A ...gamma-ray signal was observed with 6.4sigma significance. The differential energy spectrum for an energy threshold of 120GeV can be fitted by a simple power law yielding F_E(E) = (8.1+-2.1)*10^-7 (E/250GeV)^(-3.0+-0.4) TeV^-1 m^-2 s^-1. During the six days of observation in January 2005 no time variability on time scales of days was found within the statistical errors. The observed integral flux above 350GeV is nearly a factor two below the the upper limit reported by the Whipple Collaboration in 2003.
ABSTRACT
We present an analysis of the galactocentric distributions of the ‘normal’ and peculiar ‘91bg-like’ subclasses of 109 supernovae (SNe) Ia, and study the global parameters of their elliptical ...hosts. The galactocentric distributions of the SN subclasses are consistent with each other and with the radial light distribution of host stellar populations, when excluding bias against central SNe. Among the global parameters, only the distributions of u − r colours and ages are inconsistent significantly between the ellipticals of different SN Ia subclasses: the normal SN hosts are on average bluer/younger than those of 91bg-like SNe. In the colour–mass diagram, the tail of colour distribution of normal SN hosts stretches into the Green Valley – transitional state of galaxy evolution, while the same tail of 91bg-like SN hosts barely reaches that region. Therefore, the bluer/younger ellipticals might have more residual star formation that gives rise to younger ‘prompt’ progenitors, resulting in normal SNe Ia with shorter delay times. The redder and older ellipticals that already exhausted their gas for star formation may produce significantly less normal SNe with shorter delay times, outnumbered by ‘delayed’ 91bg-like events. The host ages (lower age limit of the delay times) of 91bg-like SNe does not extend down to the stellar ages that produce significant u-band fluxes – the 91bg-like events have no prompt progenitors. Our results favour SN Ia progenitor models such as He-ignited violent mergers that have the potential to explain the observed SN/host properties.
The long-duration GRB050713a was observed by the MAGIC Telescope, 40 seconds after the burst onset, and followed up for 37 minutes, until twilight. The observation, triggered by a SWIFT alert, ...covered energies above ~175 GeV. Using standard MAGIC analysis, no evidence for a gamma signal was found. As the redshift of the GRB was not measured directly, the flux upper limit, estimated by MAGIC, is still compatible with the assumption of an unbroken power-law spectrum extending from a few hundred keV to our energy range.
Recurrent haemarthrosis results in chronic synovitis and destructive arthropathy. The long‐term effect of a single haemorrhage is not known. To investigate the histopathological changes following a ...single, but major joint haemorrhage, an animal model of massive haemarthrosis without mechanical trauma was developed and is described in this manuscript. The knee joint capsule of mice deficient in coagulation factor VIII or IX and non‐haemophilic wild type mice was punctured to induce a one time, but massive haemorrhage. The single joint puncture resulted in acute haemarthrosis in both types of haemophilic mice but not in wild type mice. Subsequent to injury, the changes in the knee joints were analysed using gross, histological and radiographic assessments and compared with the uninjured knee. In addition, a novel imaging modality, micro‐computed tomography, was used to document the structural damage to the joint. Our results indicate that the long‐term changes classically observed in patients with advanced haemophilic arthropathy are evident following a single massive haemarthrosis. This model will allow a thorough investigation of the pathobiology of blood‐induced joint disease and will be useful to test the efficacy of innovative therapeutic strategies to prevent haemophilic synovitis and arthropathy.
We observe a strong effect of surfactant structure on the aggregation of ferromagnetic nanoparticles in nematic liquid crystal (LC) hosts, and the colloidal stability and ordering of the resulting ...nematic matrix. We find that ferromagnetic nanoparticles coated with surfactants that possess terminal mesogenic groups induce minimal aggregation of the nanoparticles, resulting in a 1.5 times reduction in the value of the Frederikscz transition field in comparison with the parent LC host.
OBJECTIVE:The aim of the Advanced Approach to Arterial Stiffness study was to compare arterial stiffness measured simultaneously with two different methods in different age groups of middle-aged and ...older adults with or without metabolic syndrome (MetS). The specific effects of the different MetS components on arterial stiffness were also studied.
METHODS:This prospective, multicentre, international study included 2224 patients aged 40 years and older, 1664 with and 560 without MetS. Patients were enrolled in 32 centres from 18 European countries affiliated to the International Society of Vascular Health & Aging. Arterial stiffness was evaluated using the cardio-ankle vascular index (CAVI) and the carotid–femoral pulse wave velocity (CF-PWV) in four prespecified age groups40–49, 50–59, 60–74, 75–90 years. In this report, we present the baseline data of this study.
RESULTS:Both CF-PWV and CAVI increased with age, with a higher correlation coefficient for CAVI (comparison of coefficients P < 0.001). Age-adjusted and sex-adjusted values of CF-PWV and CAVI were weakly intercorrelated (r = 0.06, P < 0.001). Age-adjusted and sex-adjusted values for CF-PWV but not CAVI were higher in presence of MetS (CF-PWV9.57 ± 0.06 vs. 8.65 ± 0.10, P < 0.001; CAVI8.34 ± 0.03 vs. 8.29 ± 0.04, P = 0.40; mean ± SEM; MetS vs. no MetS). The absence of an overall effect of MetS on CAVI was related to the heterogeneous effects of the components of MetS on this parameterCAVI was positively associated with the high glycaemia and high blood pressure components, whereas lacked significant associations with the HDL and triglycerides components while exhibiting a negative association with the overweight component. In contrast, all five MetS components showed positive associations with CF-PWV.
CONCLUSION:This large European multicentre study reveals a differential impact of MetS and age on CAVI and CF-PWV and suggests that age may have a more pronounced effect on CAVI, whereas MetS increases CF-PWV but not CAVI. This important finding may be due to heterogeneous effects of MetS components on CAVI. The clinical significance of these original results will be assessed during the longitudinal phase of the study.
Natural antimony targets were irradiated in a 60 MeV bremsstrahlung beam and gamma spectrometric measurements were performed. The goal was to establish the yield of 117mSn, a radionuclide with great ...potential for application in medicine. Considering that 117mSn is predominantly produced through a photonuclear reaction in which an charged particle is emitted (121Sb(γ,p3n)), the yield of this tin isotope is much lower than the yields of several antimony isotopes produced in (γ,xn) reactions. It has been estimated that photonuclear reactions on natural antimony could produce 117mSn activities needed for therapeutic applications, with accelerators having electron currents of the order of mA. For the used bremsstrahlung energy of 60 MeV, it was estimated how much 119mSn activity can be expected when exposing the antimony target.
•Natural Sb targets were exposed to 60 MeV bremsstrahlung.•Yield of 117mSn was determined using gamma spectroscopy.•It is estimated that (γ,xn) reaction can be used for production of 117mSn for medical purpose.
Antiviral activity of antisense oligodeoxyribonucleotides with phosphorothioate or mesyl phosphoramidate internucleotidic groups targeting the main capsid protein VP72 mRNA of the African swine fever ...virus (ASFV), either in a free form with Lipofectamine 3000 transfection or in the form of ionic complexes with amino-modified mesoporous silicon dioxide nanoparticles, has been evaluated in Vero cells infected with ASFV. Relatively high cytotoxicity of oligonucleotide nanocomplexes for Vero cells at concentrations above 500 nM was detected. Two sequences of antisense oligonucleotides were identified, which reduced the virus titer by an order of magnitude at 500 nM. The antiviral effect of nanocomplexes exceeded that of free oligonucleotides in the presence of Lipofectamine 3000, which indicates a more efficient delivery of nanocomplexes to the cells. Antisense oligonucleotides able to reduce the replication of ASFV were hitherto unknown from the literature. The obtained data can be used as a starting point for further research on the development of oligonucleotide-based antiviral drugs against the African swine fever virus.
Abstract
We present an analysis of the height distributions of the different types of supernovae (SNe) from the plane of their host galaxies. We use a well-defined sample of 102 nearby SNe appearing ...inside high-inclined (i ≥ 85°), morphologically non-disturbed S0–Sd host galaxies from the Sloan Digital Sky Survey. For the first time, we show that in all the subsamples of spirals, the vertical distribution of core-collapse (CC) SNe is about twice closer to the plane of the host disc than the distribution of SNe Ia. In Sb–Sc hosts, the exponential scale height of CC SNe is consistent with those of the younger stellar population in the Milky Way (MW) thin disc, while the scale height of SNe Ia is consistent with those of the old population in the MW thick disc. We show that the ratio of scale lengths to scale heights of the distribution of CC SNe is consistent with those of the resolved young stars with ages from ∼10 up to ∼100 Myr in nearby edge-on galaxies and the unresolved stellar population of extragalactic thin discs. The corresponding ratio for SNe Ia is consistent with the same ratios of the two populations of resolved stars with ages from a few 100 Myr up to a few Gyr and from a few Gyr up to ∼10 Gyr, as well as with the unresolved population of the thick disc. These results can be explained considering the age–scale height relation of the distribution of stellar population and the mean age difference between Type Ia and CC SNe progenitors.
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