A model of rotating convection in stellar and planetary interiors: II -- gravito-inertial wave generation

Gravito-inertial waves are excited at the interface of convective and radiative regions and by the Reynolds stresses in the bulk of the convection zones of rotating stars and planets. Such waves have notable asteroseismic signatures in the frequency spectra of rotating stars, particularly among rapidly rotating early-type stars, which provides a means of probing their internal structure and dynamics. They can also transport angular momentum, chemical species, and energy from the excitation region to where they dissipate in radiative regions. To estimate the excitation and convective parameter dependence of the amplitude of those waves, a monomodal model for stellar and planetary convection as described in Paper I is employed, which provides the magnitude of the rms convective velocity as a function of rotation rate. With this convection model, two channels for wave driving are considered: excitation at a boundary between convectively stable and unstable regions and excitation due to Reynolds-stresses. Parameter regimes are found where the sub-inertial waves may carry a significant energy flux, depending upon the convective Rossby number, the interface stiffness, and the wave frequency. The super-inertial waves can also be enhanced, but only for convective Rossby numbers near unity. Interfacially excited waves have a peak energy flux near the lower cutoff frequency when the convective Rossby number of the flows that excite them are below a critical Rossby number that depends upon the stiffness of the interface, whereas that flux decreases when the convective Rossby number is larger than this critical Rossby number.Comment: 18 pages, 6 figures, accepted in Ap

How tidal waves interact with convective vortices in rapidly rotating planets and stars

Context. The dissipation of tidal inertial waves in planetary and stellar convective regions is one of the key mechanisms that drive the evolution of star–planet and planet–moon systems. This dissipation is particularly efficient for young low-mass stars and gaseous giant planets, which are rapid rotators. In this context, the interaction between tidal inertial waves and turbulent convective flows must be modelled in a realistic and robust way. In the state-of-the-art simulations, the friction applied by convection on tidal waves is commonly modeled as an effective eddy viscosity. This approach may be valid when the characteristic length scales of convective eddies are smaller than those of the tidal waves. However, it becomes highly questionable in the case where tidal waves interact with potentially stable large-scale vortices such as those observed at the poles of Jupiter and Saturn. The large-scale vortices are potentially triggered by convection in rapidly-rotating bodies in which the Coriolis acceleration forms the flow in columnar vortical structures along the direction of the rotation axis. Aims. We investigate the complex interactions between a tidal inertial wave and a columnar convective vortex. Methods. We used a quasi-geostrophic semi-analytical model of a convective columnar vortex, which is validated by numerical simulations. First, we carried out linear stability analysis using both numerical and asymptotic Wentzel–Kramers–Brillouin–Jeffreys (WKBJ) methods. We then conducted linear numerical simulations of the interactions between a convective columnar vortex and an incoming tidal inertial wave. Results. The vortex we consider is found to be centrifugally stable in the range –Ωp ≤ Ω0 ≤ 3.62Ωp and unstable outside this range, where Ω0 is the local rotation rate of the vortex at its center and Ωp is the global planetary (stellar) rotation rate. From the linear stability analysis, we find that this vortex is prone to centrifugal instability with perturbations with azimuthal wavenumbers m = {0,1, 2}, which potentially correspond to eccentricity, obliquity, and asynchronous tides, respectively. The modes with m > 2 are found to be neutral or stable. The WKBJ analysis provides analytic expressions of the dispersion relations for neutral and unstable modes when the axial (vertical) wavenumber is sufficiently large. We verify that in the unstable regime, an incoming tidal inertial wave triggers the growth of the most unstable mode of the vortex. This would lead to turbulent dissipation. For stable convective columns, the wave-vortex interaction leads to the mixing of momentum for tidal inertial waves while it creates a low-velocity region around the vortex core and a new wave-like perturbation in the form of a progressive wave radiating in the far field. The emission of this secondary wave is the strongest when the wavelength of the incoming wave is close to the characteristic size (radius) of the vortex. Incoming tidal waves can also experience complex angular momentum exchanges locally at critical layers of stable vortices. Conclusions. The interaction between tidal inertial waves and large-scale coherent convective vortices in rapidly-rotating planets (stars) leads to turbulent dissipation in the unstable regime and complex behaviors such as mixing of momentum and radiation of new waves in the far field or wave-vortex angular momentum exchanges in the stable regime. These phenomena cannot be modeled using a simple effective eddy viscosity

Tidal dissipation in rotating and evolving giant planets with application to exoplanet systems

We study tidal dissipation in models of rotating giant planets with masses in the range $0.1 - 10 M_\mathrm{J}$ throughout their evolution. Our models incorporate a frequency-dependent turbulent effective viscosity acting on equilibrium tides (including its modification by rapid rotation consistent with hydrodynamical simulations) and inertial waves in convection zones, and internal gravity waves in the thin radiative atmospheres. We consider a range of planetary evolutionary models for various masses and strengths of stellar instellation. Dissipation of inertial waves is computed using a frequency-averaged formalism fully accounting for planetary structures. Dissipation of gravity waves in the radiation zone is computed assuming these waves are launched adiabatically and are subsequently fully damped (by wave breaking/radiative damping). We compute modified tidal quality factors $Q'$ and evolutionary timescales for these planets as a function of their ages. We find inertial waves to be the dominant mechanism of tidal dissipation in giant planets whenever they are excited. Their excitation requires the tidal period ($P_\mathrm{tide}$) to be longer than half the planetary rotation ($P_\mathrm{rot}/2$), and we predict inertial waves to provide a typical $Q'\sim 10^3 (P_\mathrm{rot}/1 \mathrm{d})^2$, with values between $10^5$ and $10^6$ for a 10-day period. We show correlations of observed exoplanet eccentricities with tidal circularisation timescale predictions, highlighting the key role of planetary tides. A major uncertainty in planetary models is the role of stably-stratified layers resulting from compositional gradients, which we do not account for here, but which could modify predictions for tidal dissipation rates.Comment: Accepted by MNRAS. 12 pages, 6 figure

Feasibility of short term drainage for diagnostic thoracoscopy

Background and Aim. Thoracoscopy is a diagnostic tool superior to other available techniques for the assessment of pleural effusions. There are numerous publications that describe the technique in detail but there is very little published on the optimal time of chest drain removal post procedure. Our aim was to retrospectively study all cases of diagnostic thoracoscopy and to ascertain the time of chest drain removal, length of hospital stay and associated complications. Methods. All patients who underwent thoracoscopy during a 6-year period were identified from a computerised database. Patients who received talc for pleurodesis were excluded as they required longer drainage time. A review of the remaining patients’ charts and radiology was performed to ascertain the predefined outcomes. Results. 124 patients had a diagnostic thoracoscopy. The time to chest drain removal was documented as less than four hours, four to 24 hours, 24 to 48 hours and greater than 48 hours in 66 (53.2%), 29 (23.4%), 12 (9.7%) and 17 (13.7%) of patients respectively. The median length of stay for all patients was one day (interquartile range, 1-4 days). There was a statistically significant difference in overall length of hospital stay between the early (48 hours) chest drain removal groups, p=0.0028. The overall complication rate was 15.9%. There was no statistical difference in complication rates between the two groups. Conclusion. This retrospective series demonstrates that early chest drain removal post diagnostic thoracoscopy is possible and safe. This is likely to confer economic benefits

Hydrodynamic modelling of dynamical tide dissipation in Jupiter's interior as revealed by Juno

Context. The Juno spacecraft has acquired exceptionally precise data on Jupiter’s gravity field, offering invaluable insights into Jupiter’s tidal response, interior structure, and dynamics, establishing crucial constraints. Aims. We aim to develop a new model for calculating Jupiter’s tidal response based on its latest interior model, while also examining the significance of different dissipation processes for the evolution of its system. We studied the dissipation of dynamical tides in Jupiter by thermal, viscous, and molecular diffusivities acting on gravito-inertial waves in stably stratified zones and inertial waves in convection ones. Methods. We solved the linearised equations for the equilibrium tide. Next, we computed the dynamical tides using linear hydrodynamical simulations based on a spectral method. The Coriolis force is fully taken into account, but the centrifugal effect is neglected. We studied the dynamical tides occurring in Jupiter using internal structure models that respect Juno’s constraints. We specifically looked at the dominant quadrupolar tidal components, and our focus is on the frequency range that corresponds to the tidal frequencies associated with Jupiter’s Galilean satellites. Results. By incorporating the different dissipation mechanisms, we calculated the total dissipation and determined the imaginary part of the tidal Love number. We find a significant frequency dependence in dissipation spectra, indicating a strong relationship between dissipation and forcing frequency. Furthermore, our analysis reveals that, in the chosen parameter regime in which kinematic viscosity and thermal and molecular diffusivities are equal, the dominant mechanism contributing to dissipation is viscosity, exceeding both thermal and chemical dissipation in magnitude. We find that the presence of stably stratified zones plays an important role in explaining the high dissipation observed in Jupiter

Positive thyroid transcription factor 1 staining strongly correlates with survival of patients with adenocarcinoma of the lung

This study investigated the relation between positive thyroid transcription factor 1 (TTF1) staining and survival of patients affected by primary adenocarcinoma (ADC) of the lung. Pathological tissue from consecutive ADC patients was collected from 2002 to 2004. The anti-TTF1 antibody (8G7G3/1, dilution of 1/200) was used. Thyroid transcription factor 1 staining was assessed for each tumour as positive or negative. Probability of survival was estimated by Kaplan–Meier and difference tested by log-rank test. A Cox's regression multivariate analysis was carried out. In all, 106 patients were studied (66% male, 69% PS0–1, 83% with stage III or IV). Tumours expressed positive TTF1 staining in 66% of cases. Multivariate analysis demonstrated an independent lower risk of death for patients whose tumour expresses positive TTF1 staining (HR=0.51, 95% CI 0.30–0.85; P=0.01) and higher grade of differentiation (HR=0.40, 95% CI 0.24–0.68; P=0.001). In conclusion, positive TTF1 staining strongly and independently correlates with survival of patients with primary ADC of the lung

Summary report of the Standards, Options and Recommendations for the management of patients with non-small-cell lung carcinoma (2000)

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

cDNA cloning and functional expression of the α-d-galactose-binding lectin frutalin in escherichia coli

cDNA clones encoding frutalin, the α-d-galactose-binding lectin expressed in breadfruit seeds (Artocarpus incisa), were isolated and sequenced. The deduced amino acid sequences indicated that frutalin may be encoded by a family of genes. The NCBI database searches revealed that the frutalin sequence is highly homologous with jacalin and mornigaG sequences. Frutalin cDNA was re-amplified and cloned into the commercial expression vector pET-25b(+) for frutalin production in Escherichia coli. An experimental factorial design was employed to maximise the soluble expression of the recombinant lectin. The results indicated that temperature, time of induction, concentration of IPTG and the interaction between the concentration of IPTG and the time of induction had the most significant effects on the soluble expression level of recombinant frutalin. The optimal culture conditions were as follows: induction with 1 mM IPTG at 22°C for 20 h, yielding 16 mg/l of soluble recombinant frutalin. SDS-PAGE and Western blot analysis revealed that recombinant frutalin was successfully expressed by bacteria with the expected molecular weight (17 kDa). These analyses also showed that recombinant frutalin was mainly produced as insoluble protein. Recombinant frutalin produced by bacteria revealed agglutination properties and carbohydrate-binding specificity similar to the native breadfruit lectin.Fundação para a Ciência e a Tecnologia (FCT