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<jats:title>Abstract</jats:title> <jats:p>The X-ray plateau emission observed in many long gamma-ray bursts (LGRBs) has been usually interpreted as the spin-down luminosity of a rapidly spinning, highly magnetized neutron star (millisecond magnetar). If this is true, then the magnetar may emit extended gravitational wave (GW) emission associated with the X-ray plateau due to nonaxisymmetric deformation or various stellar oscillations. The advanced LIGO and Virgo detectors have searched for long-duration GW transients for several years; no evidence of GWs from any magnetar has been found until now. In this work, we attempt to search for signatures of GW radiation in the electromagnetic observation of 30 LGRBs under the assumption of the magnetar model. We utilize the observations of the LGRB plateau to constrain the properties of the newborn magnetar, including the initial spin period <jats:italic>P</jats:italic> <jats:sub>0</jats:sub>, dipole magnetic field strength <jats:italic>B</jats:italic> <jats:sub> <jats:italic>p</jats:italic> </jats:sub>, and the ellipticity <jats:italic>ϵ</jats:italic>. We find that there are some tight relations between magnetar parameters, e.g., <jats:inline-formula> <jats:tex-math> <?CDATA $\epsilon \propto {B}_{p}^{1.29}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ϵ</mml:mi> <mml:mo>∝</mml:mo> <mml:msubsup> <mml:mrow> <mml:mi>B</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>p</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>1.29</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7c13ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math> <?CDATA ${B}_{p}\propto {P}_{0}^{1.14}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>B</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>p</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∝</mml:mo> <mml:msubsup> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>1.14</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7c13ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>. In addition, we derive the GW strain for the magnetar sample via their spin-down processes, and find that the GWs from these objects may not be detectable by the aLIGO and Einstein Telescope (ET) detectors. For a rapidly spinning magnetar (<jats:italic>P</jats:italic> ∼ 1 ms, <jats:italic>B</jats:italic> ∼ 10<jats:sup>15</jats:sup> G), the detection horizon for the advanced LIGO O5 detector is ∼180 Mpc. The detection of such a GW signal associated with the X-ray plateau would be a smoking gun that the central engine of a GRB is a magnetar.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We report results on the timing analysis of the 2020 giant outburst of 1A 0535+262, using broadband data from Insight-HXMT. The analysis of the pulse profile evolution from the subcritical-luminosity to the supercritical-luminosity regime is presented for the first time. We found that the observed pulse profile exhibits a complex dependence on both energy and luminosity. A dip structure at the energy of the cyclotron resonant scattering features is found for the first time in the pulse fraction–energy relation of 1A 0535+262, when the outburst evolves in a luminosity range from 4.8 × 10<jats:sup>37</jats:sup> to 1.0 × 10<jats:sup>38</jats:sup> erg s<jats:sup>−1</jats:sup>. The observed structure is luminosity dependent and appears around the source critical luminosity (∼6.7 × 10<jats:sup>37</jats:sup> erg s<jats:sup>−1</jats:sup>).</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present an analysis of 450 solitary wave pulses observed by the Langmuir Probe and Waves instrument on the Mars Atmosphere and Volatile EvolutioN spacecraft during its five passes around Mars on 2015 February 9. The magnitude and duration of these pulses vary between 1 and 25 mV m<jats:sup>−1</jats:sup> and 0.2–1.7 ms, respectively. The ambient plasma conditions suggest that these pulses are quasi-parallel to the ambient magnetic field and can be considered electrostatic. These pulses are dominantly seen in the dawn (5–6 LT) and afternoon-dusk (15–18 LT) sectors at an altitude of 1000–3500 km. The frequencies of these electric field pulses are close to the ion plasma frequency (i.e., <jats:italic>f</jats:italic> <jats:sub>pi</jats:sub> ≤ <jats:italic>f</jats:italic> <jats:sub>ef</jats:sub> ≪ <jats:italic>f</jats:italic> <jats:sub>pe</jats:sub>), which suggests that their formation is governed by ion dynamics. The computer simulation performed for the Martian magnetosheath plasma hints that these pulses are ion-acoustic solitary waves generated by drifted ion and electron populations and their spatial scales are in the range of few ion Debye lengths (1.65–10<jats:italic>λ</jats:italic> <jats:sub>di</jats:sub>). This is the first study to report and model solitary wave structures in the Martian magnetosheath.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The LIGO–Virgo–KAGRA (LVK) Collaboration has reported nearly 100 black hole (BH)–BH mergers. LVK provides estimates of rates, masses, effective spins, and redshifts for these mergers. Yet the formation channel(s) of the mergers remains uncertain. One way to search for a formation site is to contrast the properties of detected BH–BH mergers with different models of BH–BH merger formation. Our study is designed to investigate the usefulness of the total BH–BH merger mass and its evolution with redshift in establishing the origin of gravitational-wave sources. We find that the average <jats:italic>intrinsic</jats:italic> BH–BH total merger mass shows exceptionally different behaviors for the models that we adopt for our analysis. In the local universe (<jats:italic>z</jats:italic> = 0), the average merger mass changes from <jats:inline-formula> <jats:tex-math> <?CDATA ${\overline{M}}_{\mathrm{tot},\mathrm{int}}\sim 25\,{M}_{\odot }$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo stretchy="true">¯</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>tot</mml:mi> <mml:mo>,</mml:mo> <mml:mi>int</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mn>25</mml:mn> <mml:mspace width="0.25em" /> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac8167ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> for the common envelope binary evolution and open cluster formation channels, to <jats:inline-formula> <jats:tex-math> <?CDATA ${\overline{M}}_{\mathrm{tot},\mathrm{int}}\sim 30\,{M}_{\odot }$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo stretchy="true">¯</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>tot</mml:mi> <mml:mo>,</mml:mo> <mml:mi>int</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mn>30</mml:mn> <mml:mspace width="0.25em" /> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac8167ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> for the stable Roche lobe overflow binary channel, to <jats:inline-formula> <jats:tex-math> <?CDATA ${\overline{M}}_{\mathrm{tot},\mathrm{int}}\sim 45\,{M}_{\odot }$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo stretchy="true">¯</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>tot</mml:mi> <mml:mo>,</mml:mo> <mml:mi>int</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mn>45</mml:mn> <mml:mspace width="0.25em" /> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac8167ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> for the globular cluster channel. These differences are even more pronounced at larger redshifts. However, these differences are diminished when considering the LVK O3 detector sensitivity. A comparison with the LVK O3 data shows that none of our adopted models can match the data, despite the large errors on BH–BH masses and redshifts. We emphasize that our conclusions are derived from a small set of six models that are subject to numerous known uncertainties. We also note that BH–BH mergers may originate from a mix of several channels, and that other (than those adopted here) BH–BH formation channels may exist.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Laboratory measurements of X-ray emissions following charge exchange (CX) between highly charged ions and neutrals are important to assess their diagnostic utility for the nonequilibrium astrophysical plasma environments, where hot flows meet cold gases. With a high-resolution X-ray quantum microcalorimeter detector, we report the CX-induced X-ray spectra and line ratios in Ne<jats:sup>8+</jats:sup> on He and Kr collisions at solar wind velocities of 392, 554, 678, and 876 km s<jats:sup>−1</jats:sup>, respectively. The experimentally determined line ratios quantify the differences in CX state selectivity and the following X-ray emission between He and Kr at different collision velocities. This suggests that target and velocity dependence should be considered for accurately modeling astrophysical CX plasmas.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We analyze the gravitational wave signals with a model-independent time-frequency analysis, which is improved from the Hilbert–Huang transform (HHT) and optimized for characterizing the frequency variability on the time-frequency map. Instead of the regular HHT algorithm, i.e., obtaining intrinsic mode functions with ensemble empirical mode decomposition and yielding the instantaneous frequencies, we propose an alternative algorithm that operates the ensemble mean on the time-frequency map. We systematically analyze the known gravitational wave events of the compact binary coalescence observed in the first gravitational-wave transient catalog, and in the simulated gravitational wave signals from core-collapse supernovae (CCSNe) with our method. The time-frequency maps of the binary black hole coalescence cases show much more detail compared to those wavelet spectra. Moreover, the oscillation in the instantaneous frequency caused by mode-mixing could be reduced with our algorithm. For the CCSNe data, the oscillation from the proto-neutron star and the radiation from the standing accretion shock instability can be precisely determined with the HHT in great detail. More importantly, the initial stage of different modes of oscillations can be clearly separated. These results provide new hints for further establishment of the detecting algorithm and new probes to investigate the underlying physical mechanisms.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Transiting Exoplanet Survey Satellite (TESS) is performing a near all-sky survey for planets that transit bright stars. It provides excellent photometric data for asteroseismology of solar-like stars that exhibit oscillation by a convection-driven mechanism. In this paper, we analyze the light curves of 14 stars that are observed by TESS. These stars mainly focus on Sector 21 and the other Sectors intersecting with Sector 21. Through crossmatching with the LAMOST surveys, 14 stars with signals of solar-like oscillations are selected, and asteroseismic analysis is present. The frequency of maximum power <jats:inline-formula> <jats:tex-math> <?CDATA ${\nu }_{\max }$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>ν</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>max</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7b7dieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and the large frequency separation Δ<jats:italic>ν</jats:italic> are extracted from its frequency power spectrum using the pySYD pipeline. Scaling relations are an attractive method that can easily and immediately be applied to observations to derive the stellar properties. To validate the different calibrated scaling relations for 14 TESS stars, the fundamental stellar properties are estimated by the relations and compared with grid-based modeling results, which use the constraints of global asteroseismic parameters and nonasteroseismic parameters. The new red-giant branch (RGB) scaling relations are found to overestimate the radius and mass when compared to the grid results, while the <jats:italic>f</jats:italic> <jats:sub>Δ<jats:italic>ν </jats:italic> </jats:sub>scaling relations lead to overall lower radius and mass estimates. The average uncertainties of these stars from grid modeling are within 2% in the radius and 3% in the mass. Regardless of the method, we can get almost equally good results of log <jats:italic>g</jats:italic> for all the stars. Besides the grid method, the new RGB scaling relations for ages provide a simple and accurate method to determine the stellar ages.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Fast empirical models of the broad emission line region (BLR) are a powerful tool to interpret velocity-resolved reverberation mapping (RM) data, estimate the mass of the supermassive black holes, and gain insight into its geometry and kinematics. Much of the effort so far has been devoted to describing the emissivity of one emission line at a time. We present here an alternative approach aimed at describing the underlying BLR gas distribution, by exploiting simple numerical recipes to connect it with emissivity. This approach is a step toward describing multiple emission lines originating from the same gas and allows us to clarify some issues related to the interpretation of RM data. We illustrate this approach—implemented in the code <jats:sc>CARAMEL-gas</jats:sc>—using three data sets covering the H<jats:italic>β</jats:italic> emission line (Mrk 50, Mrk 1511, Arp 151) that have been modeled using the emissivity-based version of the code. As expected, we find differences in the parameters describing the BLR gas and emissivity distribution, but the emissivity-weighted lag measurements and all other model parameters including black hole mass and overall BLR morphology and kinematics are consistent with the previous measurements. We also model the H<jats:italic>α</jats:italic> emission line for Arp 151 using both the gas- and emissivity-based BLR models. We find ionization stratification in the BLR with H<jats:italic>α</jats:italic> arising at larger radii than H<jats:italic>β</jats:italic>, while all other model parameters are consistent within the uncertainties.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We provide the first combined cosmological analysis of the South Pole Telescope (SPT) and Planck cluster catalogs. The aim is to provide an independent calibration for Planck scaling relations, exploiting the cosmological constraining power of the SPT-SZ cluster catalog and its dedicated weak lensing (WL) and X-ray follow-up observations. We build a new version of the Planck cluster likelihood. In the <jats:italic>ν</jats:italic>Λ CDM scenario, focusing on the mass slope and mass bias of Planck scaling relations, we find <jats:inline-formula> <jats:tex-math> <?CDATA ${\alpha }_{\mathrm{SZ}}={1.49}_{-0.10}^{+0.07}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>α</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>SZ</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>1.49</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.07</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7ab4ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math> <?CDATA ${\left(1-b\right)}_{\mathrm{SZ}}={0.69}_{-0.14}^{+0.07}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mfenced close=")" open="("> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>b</mml:mi> </mml:mrow> </mml:mfenced> </mml:mrow> <mml:mrow> <mml:mi>SZ</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>0.69</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.14</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.07</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7ab4ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, respectively. The results for the mass slope show a ∼4 <jats:italic>σ</jats:italic> departure from the self-similar evolution, <jats:italic>α</jats:italic> <jats:sub>SZ</jats:sub> ∼ 1.8. This shift is mainly driven by the matter density value preferred by SPT data, Ω<jats:sub> <jats:italic>m</jats:italic> </jats:sub> = 0.30 ± 0.03, lower than the one obtained by Planck data alone, <jats:inline-formula> <jats:tex-math> <?CDATA ${{\rm{\Omega }}}_{m}={0.37}_{-0.06}^{+0.02}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">Ω</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>m</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>0.37</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.06</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.02</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7ab4ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>. The mass bias constraints are consistent both with outcomes of hydrodynamical simulations and external WL calibrations, (1 − <jats:italic>b</jats:italic>) ∼ 0.8, and with results required by the Planck cosmic microwave background cosmology, (1 − <jats:italic>b</jats:italic>) ∼ 0.6. From this analysis, we obtain a new catalog of Planck cluster masses <jats:italic>M</jats:italic> <jats:sub>500</jats:sub>. We estimate the ratio between the published Planck <jats:italic>M</jats:italic> <jats:sub>SZ</jats:sub> masses and our derived masses <jats:italic>M</jats:italic> <jats:sub>500</jats:sub>, as a “measured mass bias,” <jats:inline-formula> <jats:tex-math> <?CDATA ${\left(1-b\right)}_{M}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mfenced close=")" open="("> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>b</mml:mi> </mml:mrow> </mml:mfenced> </mml:mrow> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7ab4ieqn4.gif" xlink:type="simple" /> </jats:inline-formula>. We analyze the mass, redshift, and detection noise dependence of <jats:inline-formula> <jats:tex-math> <?CDATA ${\left(1-b\right)}_{M}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mfenced close=")" open="("> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>b</mml:mi> </mml:mrow> </mml:mfenced> </mml:mrow> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac7ab4ieqn5.gif" xlink:type="simple" /> </jats:inline-formula>, finding an increasing trend toward high redshift and low mass. These results mimic the effect of departure from self-similarity in cluster evolution, showing different dependencies for the low-mass, high-mass, low-<jats:italic>z</jats:italic>, and high-<jats:italic>z</jats:italic> regimes.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Isotopic and elemental abundances seen in Galactic cosmic rays (GCRs) imply that ∼20% of the cosmic-ray (CR) nuclei are probably synthesized by massive Wolf–Rayet (W-R) stars. Massive star clusters hosting W-R- and OB-type stars have been proposed as potential GCR accelerators for decades, in particular via diffusive shock acceleration at wind termination shocks. Here we report the analysis of Fermi Large Area Telescope data toward the direction of Masgomas-6a, a young massive star cluster candidate hosting two W-R stars. We detect an extended <jats:italic>γ</jats:italic>-ray source with a test statistic = 183 in the vicinity of Masgomas-6a, spatially coincident with two unassociated Fermi 4FGL sources. We also present the CO observational results of molecular clouds in this region, using the data from the Milky Way Imaging Scroll Painting project. The <jats:italic>γ</jats:italic>-ray emission intensity correlates well with the distribution of molecular gas at the distance of Masgomas-6a, indicating that these <jats:italic>γ</jats:italic>-rays may be produced by CRs accelerated by massive stars in Masgomas-6a. At the distance of 3.9 kpc of Masgomas-6a, the luminosity of the extended source is (1.81 ± 0.02) × 10<jats:sup>35</jats:sup> erg s<jats:sup>−1</jats:sup>. With a kinetic luminosity of ∼10<jats:sup>37</jats:sup> erg s<jats:sup>−1</jats:sup> in the stellar winds, the W-R stars are capable of powering the <jats:italic>γ</jats:italic>-ray emission via neutral pion decay resulted from CR proton–proton interactions. The size of the GeV source and the energetic requirement suggests a CR diffusion coefficient smaller than that in the Galactic interstellar medium, indicating a strong suppression of CR diffusion in the molecular cloud.</jats:p>