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Gas bubbles bursting at the sea surface produce drops, which contribute to marine aerosols. The contamination or enrichment of water by surface‐active agents, of biological or anthropogenic origin, has long been recognized as affecting the bubble bursting processes and the spray composition. However, despite an improved understanding of the physics of a single bursting event, a quantitative understanding of the role of the physico‐chemical conditions on assemblies of bursting bubbles remains elusive. We present experiments on the drop production by millimetric, collective bursting bubbles, under varying surfactant concentration and bubble density. We demonstrate that the production of supermicron droplets (with radius larger than 35 μm) is non‐monotonic as the surfactant concentration increases. The bursting efficiency is optimal for short‐lived, sparsely distributed and non‐coalescing bubbles. We identify the combined role of contamination on the surface bubble arrangement and the modification of the jet drop production process in the bursting efficiency. Plain Language Summary: Understanding the production of primary ocean spray aerosol and its dependence on meteorological and environmental variables is critical for modeling potentially health‐adverse effects from dispersants used to break down oil spills, as well as radiative processes and cloud microphysical properties. We demonstrate experimentally that the coupling between the chemical properties of contaminated water and the physical mechanism of droplet production when a bubble bursts controls the efficiency of aerosols production during collective bubble bursting, and reveals an optimal production regime at intermediate contamination. This fundamental study paves the way to improved predictions of aerosol production in contaminated water. Key Points: Spray droplet production by collective bursting bubbles is non‐monotonic as surfactant concentration increasesAn optimal drop production is observed at intermediate surfactant concentrations for short‐lived, non‐coalescing surface bubblesThe saturation of the water surface by air bubbles, or formation of a foam, inhibits the drop production by bubble bursting [ABSTRACT FROM AUTHOR]

Introduction: Cerebral abscesses are rare, occurring in approximately 0.3-1 per 100 000 patients. Mortality rate still remains as high as 22%. Very few cases of acute psychotic episodes associated with brain abscess have been reported. Objectives: To present a case report of a patient with schizofrenia associated with multiple brain abscesses, focusing on clinical features and managing challenges. Methods: Presentation of a clinical case supported by a nonsystematic review of literature containing the key-words "brain abscess", "psychosis" and "schizophrenia". Results: This is a case report of a male 44-year-old patient with a known history of schizophrenia since the age of 18 and with multiple brain abscesses diagnosed 2 month ago. He was admitted to our inpatient service after discontinuation of her medication resulting in an acute psychotic episode. Antibiotic therapy with rifampicine, metronidazole, trimethoprim and sulfamethoxazole was started. Also, administration of clozapine was initiated (up to 400mg/day) with partial improvement, so aripiprazole was added (up to 45 mg/day), with insufficient response. We suspected of a drug interaction between rifampicine (known potent broad inducer of drug-metabolizing enzymes) and antipsychotic medication, so we decided to change aripiprazole to amisulpride 1200 mg/day, which CYP-catalyzed metabolism appears to be minor. A significant improvement in positive symptoms and mood was observed. The patient has since had no delusions or hallucinations and is living independently at home. Conclusions: This clinical case highlights the possible association between brain abscesses and relapses in schizophrenia. It is of utmost importance to be aware for possible drug interactions between antibiotic therapy and antipsychotic medication. [ABSTRACT FROM AUTHOR]

Electroconvulsive therapy is a type of therapy frequently used in psychiatric clinical practice. Although it is generally used for the treatment of affective disorders or severe and/or resistant psychotic disorders, it has also demonstrated its usefulness in many other neuropsychiatric conditions. We present the case of a 26-year-old woman, previously diagnosed with a functional neurological disorder-with fixed dystonia phenotype in the right upper limb-, admitted to our hospital for a severe depressive episode. After noting the absence of clinical improvement with psychopharmacological treatment, it was decided to give electroconvulsive therapy, receiving a total of 11 sessions, 9 of which were effective, with bifrontotemporal application, three times a week. The patient experienced a significant improvement, not only at an affective and behavioral level, but also in the dystonia, recovering most of the mobility in the right hand and completely relinquishing the pain. Although scientific evidence is scarce regarding the use of electroconvulsive therapy in functional neurological disorders, this clinical case supports the existing literature and raises this therapy as a possibility in resistant and comorbid conditions with severe affective disorders.

Microplastics are globally ubiquitous in marine environments, and their concentration is expected to continue rising at significant rates as a result of human activity. They present a major ecological problem with well-documented environmental harm. Sea spray from bubble bursting can transport salt and biological material from the ocean into the atmosphere, and there is a need to quantify the amount of microplastic that can be emitted from the ocean by this mechanism. We present a mechanistic study of bursting bubbles transporting microplastics. We demonstrate and quantify that jet drops are efficient at emitting microplastics up to 280 μ m in diameter and are thus expected to dominate the emitted mass of microplastic. The results are integrated to provide a global microplastic emission model which depends on bubble scavenging and bursting physics; local wind and sea state; and oceanic microplastic concentration. We test multiple possible microplastic concentration maps to find annual emissions ranging from 0.02 to 7.4-with a best guess of 0.1-mega metric tons per year and demonstrate that while we significantly reduce the uncertainty associated with the bursting physics, the limited knowledge and measurements on the mass concentration and size distribution of microplastic at the ocean surface leaves large uncertainties on the amount of microplastic ejected., (© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.)

Objective: The objective of this study was to determine the effectiveness of an intervention related to social isolation and loneliness among hospitalized patients by improving: 1) social connectedness; 2) anxiety; and 3) loneliness and to evaluate experiences of the connection intervention., Background: Social isolation and loneliness can lead to detrimental effects on morbidity/mortality and health indices. A connection intervention was developed by investigators using key strategies to promote connectedness, providing in-person contact for hospitalized patients to meet individual and self-care needs., Methods: This quasi-experimental study was conducted in a Midwest adult academic health center. Social connectedness, anxiety, and loneliness were evaluated at baseline and postintervention using a paired-sample t test. Experience responses were analyzed using content analysis., Results: There were no significant differences in social connectedness, anxiety, or loneliness when comparing baseline with postintervention. Experience themes included sharing personal stories back and forth, treating me as a person, mitigating loneliness, and finding benefit., Conclusion: Despite nonsignificant findings, participants found benefit in filling the social void of being an inpatient. Clinicians should ensure that holistic care is delivered to hospitalized inpatients. Inclusive patient-centered strategies targeted to decrease social isolation and loneliness among acute care inpatients should continue to be developed and tested., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Ocean spray aerosol formed by bubble bursting are at the core of a broad range of atmospheric processes: they are efficient cloud condensation nuclei and carry a variety of chemical, biological, and biomass material from the surface of the ocean to the atmosphere. The origin and composition of these aerosols is sensibly controlled by the detailed fluid mechanics of bubble bursting. This perspective summarizes our present-day knowledge on how bursting bubbles at the surface of a liquid pool contribute to its fragmentation, namely to the formation of droplets stripped from the pool, and associated mechanisms. In particular, we describe bounds and yields for each distinct mechanism, and the way they are sensitive to the bubble production and environmental conditions. We also underline the consequences of each mechanism on some of the many air-sea interactions phenomena identified to date. Attention is specifically payed at delimiting the known from the unknown and the certitudes from the speculations., (© The Author(s) 2022. Published by Oxford University Press on behalf of the National Academy of Sciences.)

Although bubble pinch-off is an archetype of a dynamical system evolving toward a singularity, it has always been described in idealized theoretical and experimental conditions. Here, we consider bubble pinch-off in a turbulent flow representative of natural conditions in the presence of strong and random perturbations, combining laboratory experiments, numerical simulations, and theoretical modeling. We show that the turbulence sets the initial conditions for pinch-off, namely the initial bubble shape and flow field, but after the pinch-off starts, the turbulent time at the neck scale becomes much slower than the pinching dynamics: The turbulence freezes. We show that the average neck size, [Formula: see text], can be described by [Formula: see text], where [Formula: see text] is the pinch-off or singularity time and [Formula: see text], in close agreement with the axisymmetric theory with no initial flow. While frozen, the turbulence can influence the pinch-off through the initial conditions. Neck shape oscillations described by a quasi-2-dimensional (quasi-2D) linear perturbation model are observed as are persistent eccentricities of the neck, which are related to the complex flow field induced by the deformed bubble shape. When turbulent stresses are less able to be counteracted by surface tension, a 3-dimensional (3D) kink-like structure develops in the neck, causing [Formula: see text] to escape its self-similar decrease. We identify the geometric controlling parameter that governs the appearance of these kink-like interfacial structures, which drive the collapse out of the self-similar route, governing both the likelihood of escaping the self-similar process and the time and length scale at which it occurs., Competing Interests: The authors declare no competing interest., (Copyright © 2019 the Author(s). Published by PNAS.)

After a bubble bursts at a liquid surface, the collapse of the cavity generates capillary waves, which focus on the axis of symmetry to produce a jet. The cavity and jet dynamics are primarily controlled by a nondimensional number that compares capillary inertia and viscous forces, i.e., the Laplace number La=ργR_{0}/μ^{2}, where ρ, μ, γ, and R_{0} are the liquid density, viscosity, interfacial tension, and the initial bubble radius, respectively. In this Letter, we show that the time-dependent profiles of cavity collapse (tt_{0}) both obey a |t-t_{0}|^{2/3} inviscid scaling, which results from a balance between surface tension and inertia forces. Moreover, we present a scaling law, valid above a critical Laplace number, which reconciles the time-dependent scaling with the recent scaling theory that links the Laplace number to the final jet velocity and ejected droplet size. This leads to a self-similar formula which describes the history of the jetting process, from cavity collapse to droplet formation.

In propagating wave systems, three- or four-wave resonant interactions constitute a classical nonlinear mechanism exchanging energy between the different scales. Here we investigate three-wave interactions for gravity-capillary surface waves in a closed laboratory tank. We generate two crossing wave trains and we study their interaction. Using two optical methods, a local one (laser doppler vibrometry) and a spatiotemporal one (diffusive light photography), a third wave of smaller amplitude is detected, verifying the three-wave resonance conditions in frequency and in wave number. Furthermore, by focusing on the stationary regime and by taking into account viscous dissipation, we directly estimate the growth rate of the resonant mode. The latter is then compared to the predictions of the weakly nonlinear triadic resonance interaction theory. The obtained results confirm qualitatively and extend previous experimental results obtained only for collinear wave trains. Finally, we discuss the relevance of three-wave interaction mechanisms in recent experiments studying gravity-capillary turbulence.

This work presents direct numerical simulations of capillary wave turbulence solving the full three-dimensional Navier-Stokes equations of a two-phase flow. When the interface is locally forced at large scales, a statistical stationary state appears after few forcing periods. Smaller wave scales are generated by nonlinear interactions, and the wave height spectrum is found to obey a power law in both wave number and frequency, in good agreement with weak turbulence theory. By estimation of the mean energy flux from the dissipated power, the Kolmogorov-Zakharov constant is evaluated and found to be compatible with the exact theoretical value. The time scale separation between linear, nonlinear interaction, and dissipative times is also observed. These numerical results confirm the validity of the weak turbulence approach to quantify out-of equilibrium wave statistics.

We study experimentally the influence of dissipation on stationary capillary wave turbulence on the surface of a liquid by changing its viscosity. We observe that the frequency power-law scaling of the capillary spectrum departs significantly from its theoretical value when the dissipation is increased. The energy dissipated by capillary waves is also measured and found to increase nonlinearly with the mean power injected within the liquid. Here we propose an experimental estimation of the energy flux at every scale of the capillary cascade. The latter is found to be nonconstant through the scales. For fluids of low enough viscosity, we found that both capillary spectrum scalings with the frequency and the newly defined mean energy flux are in good agreement with wave turbulence theory. The Kolmogorov-Zakharov constant is then experimentally estimated and compared to its theoretical value.

We report on the observation of freely decaying capillary wave turbulence on the surface of a fluid. The capillary wave turbulence spectrum decay is found to be self-similar in time with the same power law exponent as the one found in the stationary regime, in agreement with weak turbulence predictions. The amplitude of all Fourier modes are found to decrease exponentially with time at the same damping rate. The longest wavelengths involved in the system are shown to be damped by a viscous surface boundary layer. These long waves play the role of an energy source during the decay that sustains nonlinear interactions to keep capillary waves in a wave turbulent state.

The present review aims to offer a concise of information about the diverse mental disorders affecting HIV-infected patients. Although most studies coincide in remarking that HIV-infected patients are frequently burden with psychological distress, the prevalence of the different mental disorders being present at the time of evaluation is widely variable. HIV infection clinical stage, prior psychiatric morbidity, and sociodemographic issues are also related to the type and risk for mental disorders. When planning therapeutic interventions, psychopharmacological or psychological, for HIV-infected patients several peculiarities should be taken into account. The accurate psychosocial evaluation and prompt therapeutic intervention, could help to reduce psychiatric-psychologic morbidity in a population of patients with multifactorial impairment in their quality of life and improve the adherence to treatment.