The dynamics, structure and stability of zonal jets in planetary flows are still poorly understood, especially in terms of coupling with the small-scale turbulent flow. Here, we use an experimental approach to address the questions of zonal jets formation and long-term evolution. A strong and uniform topographic $\beta$-effect is obtained inside a water-filled rotating tank thanks to the paraboloidal fluid free upper surface combined with a specifically designed bottom plate. A small-scale turbulent forcing is performed by circulating water through the base of the tank. Time-resolving particle image velocimetry measurements reveal the self-organization of the flow into multiple zonal jets with a strong instantaneous signature. We identify a subcritical bifurcation between two regimes of jets depending on the forcing intensity. In the first regime, the jets are steady, weak in amplitude, and directly forced by the local Reynolds stresses due to our forcing. In the second one, we observe highly energetic and dynamic jets of width larger than the forcing scale. An analytical modelling based on the quasi-geostrophic approximation reveals that this subcritical bifurcation results from the resonance between the directly forced Rossby waves and the background zonal flow.

This study explores experimentally the flows driven by precession in an oblate spheroid, in the vicinity of the possible resonance with the tilt-over mode. Two main phenomena are reported, combining observations and velocity measurements. First, a hysteretic cycle is quantitatively described between two uniform vorticity solutions, in good agreement with the historical analytical study of Busse (J. Fluid Mech., vol. 33, 1968, pp. 739–752). We then address the destabilization of each branch at low enough Ekman number. We confirm the possible presence of a so-called conical shear instability, recently depicted in the sphere by Lin et al. (Phys. Fluids, vol. 27, 2015, 046601) and in the spheroid by Horimoto et al. (Phys. Rev. Fluids, vol. 5, 2020, 063901). However, available measurements in the accessible parameter range are not sufficient to definitively discard an elliptical or shear origin of the excited instabilities in the spheroid, as first introduced by Kerswell (Geophys. Astrophys. Fluid Dyn., vol. 72, 1993, pp. 107–144).

Up until now, there is much debate about the role of asymptomatic patients and pauci-symptomatic patients in severe acute respiratory syndrome novel coronavirus 2 (SARS-CoV-2) transmission, and little is known about the kinetics of viral ribonucleic acid (RNA) shedding in these populations. This article aims to describe key features and the nature of asymptomatic and pauci-symptomatic SARS-CoV-2 infected patients. The cohort consisted of six participants, three pairs, which were infected with SARS-CoV-2 during February 2020 on board the Diamond Princess. Of the six confirmed (reverse transcription polymerase chain reaction [RT-PCR]) cases, four were initially diagnosed in Japan and two upon their arrival to Israel. Duration of infection was between four days and up to 26 days. Of the six patients, three were completely asymptomatic and the others were pauci-symptomatic. All five patients in whom a computerized tomography (CT) scan was performed had lung pathology. In one patient, infectivity was tested using cell culture and a cytopathic effect was demonstrated. A serology test was performed in three of the patients and all three had a positive immunoglobulin G (IgG) four to eight weeks after disease onset. This case series demonstrates that asymptomatic and pauci-symptomatic patients may play a role in infection transmission by demonstrating probable transmission among asymptomatic spouses and by demonstrating a viable virus via a cell culture. Additionally, asymptomatic and pauci-symptomatic patients can have lung pathology and developing IgG antibodies.

We explore the near-resonant interaction of inertial waves with geostrophic modes in rotating fluids via numerical and theoretical analysis. When a single inertial wave is imposed, we find that some geostrophic modes are unstable above a threshold value of the Rossby number $kRo$ based on the wavenumber and wave amplitude. We show this instability to be caused by triadic interaction involving two inertial waves and a geostrophic mode such that the sum of their eigenfrequencies is non-zero. We derive theoretical scalings for the growth rate of this near-resonant instability. The growth rate scaled by the global rotation rate is proportional to $(kRo)^2$ at low $kRo$ and transitions to a $kRo$ scaling for larger $kRo$ . These scalings are in excellent agreement with direct numerical simulations. This instability could explain recent experimental observations of geostrophic instability driven by waves.

Previous studies have observed reduced vagal modulation in patients with acute schizophrenia and their first degree relatives, thus suggesting a genetic predisposition.

To investigate vagal modulation at brain stem level, we investigated the coupling between heart rate and breathing as a putative measure of central autonomic function in 19 patients, 19 of their relatives and 19 matched control subjects. The interaction of heart rate and breathing was investigated in all groups applying the non-linear parameter cross-ApEn, indicating the asynchrony between both time series.

The main finding of our study is a significantly increased cross-ApEn value, indicating reduced central vagal modulation both in relatives and patients suffering from schizophrenia.

Our results suggest that autonomic dysfunction in schizophrenia is present in first-degree relatives not only at the target organs as shown previously, but also affects the central vagal component.

Co-morbit medical conditions such as hyperglycemia, diabetes, hypertension are frequent in psychiatric patients. Tragically, this population is less likely to receive necessary medical care during hospitalization and has higher rates of morbidity and mortality from medical illnesses when compared with nonpsychiatric population. The present study evaluated for diagnosis and management of comorbit medical conditions in hospitalized patients with and without mental illness.

Background: There is an unmet need for blood-based biomarkers that can reliably detect MS disease activity. Serum Biomarkers of interest includ Neurofilament-light-chain (NfL), Glial-fibrillary-strocyte-protein(GFAP) and Tau. Bone Marrow Transplantation (BMT) is reserved for aggressive forms of MS and has been shown to halt detectable CNS inflammatory activity for prolonged periods. Significant pre-treatment tissue damage at followed by inflammatory disease abeyance should be reflected longitudinal sera collected from these patients. Methods: Sera were collected from 23 MS patients pre-treatment, and following BMT at 3, 6, 9 and 12-months in addition from 33 non-inflammatory neurological controls. Biomarker quantification was performed with SiMoA. Results: Pre-AHSCT levels of serum NfL and GFAP but not Tau were elevated compared to controls (p=0.0001), and NfL correlated with lesion-based disease activity (6-month-relapse, MRI-T2 and Gadolinium-enhancement). 3-months post-treatment, while NfL levels remained elevated, Tau/GFAP paradoxically increased (p=0.0023/0.0017). These increases at 3m correlated with MRI ‘pseudoatrophy’ at 6-months. NfL/Tau levels dropped to that of controls by 6-months (p=0.0036/0.0159). GFAP levels dropped progressively after 6-months although even at 12-months remained higher than controls (p=0.004). Conclusions: NfL was the closest correlate of MS disease activity and treatment response. Chemotherapy-related toxicity may account for transient increases in NfL, Tau and MRI brain atrophy post-BMT.

Highly resolved, well-dated paleoclimate records from the southern South African coast are needed to contextualize the evolution of the highly diverse extratropical plant communities of the Greater Cape Floristic Region (GCFR) and to assess the environmental impacts on early human hunter-gatherers. We present new speleothem stable oxygen and carbon isotope ratios (δ18Oc and δ13C) from two caves at Pinnacle Point, South Africa, covering the time between 330 and 43 ka. Composite δ18Oc and δ13C records were constructed for Staircase Cave and PP29 by combining all stable isotope analyses into a single time series and smoothing by a 3-point running mean. δ18Oc and δ13C values record changes in rainfall seasonality and the proportions of C3 and C4 plants in the vegetation, respectively. We show that in general increased summer rainfall brought about a wider spread of C4 grasses and retreat of the C3 plant–dominated GCFR communities. The occurrence of summer rainfall on the southern coast of South Africa was linked to total rainfall amounts in the interior region through tropical temperate troughs. These rainfall systems shifted the southern coastal climate toward more summer (winter) rainfall when precession was high (low) and/or the westerlies were in a northern (southern) position.

Using water–salt water laboratory experiments, we investigate the mechanism of erosion by a turbulent jet impinging onto a density interface, for moderate Reynolds and Froude numbers. The Froude number is defined by $Fr_{i}=u_{i}/\sqrt{b_{i}g^{\prime }}$ , with $u_{i}$ and $b_{i}$ , the typical velocity and width of the jet at the interface, and $g^{\prime }$ the reduced gravitational acceleration. The Froude number $Fr_{i}$ characterizes the competition between inertial forces against the restoring buoyancy force. Contrary to previous observations reporting baroclinic destabilization of the interface, we show that the entrainment, in the range of parameters explored here, is driven by interfacial gravity waves. The waves are generated by the barotropic excitation coming from the turbulent fluctuations of the jet; they are then amplified by a mechanism of wave-induced stress; and they finally break and induce entrainment and mixing. Based on those physical observations, we introduce a scaling model for the entrainment rate, which varies continuously from $Fr_{i}^{3}$ to an $Fr_{i}$ power law from small to large Froude numbers, in agreement with the present and some of the previous laboratory data.

Modern conceptions of brain function consider the brain as a “predictive organ,” where learned regularities about the world are utilised to facilitate perception of incoming sensory input. Critically, this process hinges on a role for cognitive penetrability. We review a mechanism to explain this process and expand our previous proposals of cognitive penetrability in visual recognition to social vision and visual hallucinations.