Cross-frequency couplings in non-sinusoidal dynamics of interacting oscillators: Acoustic estimation of the radial position and spatial stability of nonlinear oscillating bubbles

In this work, the analysis of cross-frequency couplings (CFC) is introduced in the context of nonlinear acoustics related to the dynamics of bubble(s)-resonator systems. The results obtained from experiments specifically designed to untangle the causal connection between the CFC patterns observed at the signal level and the underlying physical processes, are discussed. It was found that “causal” amplitude-to-amplitude (AAC) and amplitude-to-phase (APC) couplings emerge in the system dynamics as a consequence of the bubble(s)-resonator mechanistic interaction in the oscillatory steady-state. In these CFC patterns, the amplitude of the fundamental frequency component (f0) effectively modulates the amplitude and relative phase of the harmonic components (Nf0). Moreover, these AAC and APC couplings give rise to “epiphenomenal” phase-to-amplitude (PAC) and phase-to-phase (PPC) couplings, in which the link between modulating and modulated parameters represents a correlation rather than a causal connection. It is shown that these CFC patterns can be exploited to determine the presence, spatial stability and radial position of nonlinear oscillating bubble(s) trapped within the acoustic chamber. Potential applications of the proposed techniques are also discussed. Substantial evidence is presented showing that CFC patterns emerging from quasi-periodic non-sinusoidal waveforms are informative on the interaction between underlying oscillators.Fil: Dellavale, Damián. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Rosselló, Juan Manuel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Positional stability and radial dynamics of sonoluminescent bubbles under bi-harmonic driving: Effect of the high-frequency component and its relative phase

The use of bi-frequency driving in sonoluminescence has proved to be an effective way to avoid the spatial instability (pseudo-orbits) developed by bubbles in systems with high viscous liquids like sulfuric or phosphoric acids. In this work, we present extensive experimental and numerical evidence in order to assess the effect of the high frequency component (PAcHF) of a bi-harmonic acoustic pressure field on the dynamic of sonoluminescent bubbles in an aqueous solution of sulfuric acid. The present study is mainly focused on the role of the harmonic frequency (Nf0) and the relative phase between the two frequency components (φb) of the acoustic field on the spatial, positional and diffusive stability of the bubbles. The results presented in this work were analyzed by means of three different approaches. First, we discussed some qualitative considerations about the changes observed in the radial dynamics, and the stability of similar bubbles under distinct bi-harmonic drivings. Later, we have investigated, through a series of numerical simulations, how the use of high frequency harmonic components of different order N, affects the positional stability of the SL bubbles. Furthermore, the influence of φb in their radius temporal evolution is systematically explored for harmonics ranging from the second to the fifteenth harmonic (N=2-15). Finally, a multivariate analysis based on the covariance method is performed to study the dependences among the parameters characterizing the SL bubble. Both experimental and numerical results indicate that the impact of PAcHF on the positional instability and the radial dynamics turns to be progressively negligible as the order of the high frequency harmonic component grows (i.e. N1), however its effectiveness on the reduction of the spatial instability remains unaltered or even improved.Fil: Rosselló, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Dellavale Clara, Hector Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; ArgentinaFil: Bonetto, Fabian Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentin

Acoustic Resonance Effects and Cavitation in SAW Aerosol Generation

The interaction of surface acoustic waves (SAWs) with liquids enables the production of aerosols with adjustable droplet sizes in the micrometer range expelled from a very compact source. Understanding the nonlinear acousto-hydrodynamics of SAWs with a regulated micro-scale liquid film is essential for acousto-microfluidics platforms, particularly aerosol generators. In this study, we demonstrate the presence of micro-cavitation in an MHz-frequency SAW aerosol generation platform, which is touted as a leap in aerosol technology with versatile application fields including biomolecule inhalation therapy, micro-chromatography and spectroscopy, olfactory displays, and material deposition. Using analysis methods with high temporal and spatial resolution, we demonstrate that SAWs stabilize spatially arranged liquid micro-domes atop the generator's surface. Our experiments show that these liquid domes become acoustic resonators with highly fluctuating pressure amplitudes that can even nucleate cavitation bubbles, as supported by analytical modeling. The observed fragmentation of liquid domes indicates the participation of three droplet generation mechanisms, including cavitation and capillary-wave instabilities. During aerosol generation, the cavitation bubbles contribute to the ejection of droplets from the liquid domes and also explain observed microstructural damage patterns on the chip surface eventually caused by cavitation-based erosion

Infección por SARS-CoV-2 : implicaciones para la salud sexual y reproductiva. Una declaración de posición de la Asociación Española de Andrología, Medicina Sexual y Reproductiva (ASESA)

El objetivo de esta revisión es resumir la evidencia disponible sobre los posibles efectos adversos del SARS-CoV-2 en el sistema reproductor masculino y proporcionar una declaración de posición oficial de la Asociación Española de Andrología, Medicina Sexual y Reproductiva (ASESA). Se realizó una búsqueda exhaustiva en las bibliotecas Pubmed, Web of Science, Embase, Medline, Cochrane y MedRxiv. No se ha confirmado la orquitis como una posible complicación de la infección por SARS-CoV-2. Un estudio informó que el 19% de los hombres con COVID-19 presentaban molestias escrotales sugestivas de orquitis viral, que no se pudo confirmar. Es posible que el virus no infecte los testículos directamente, si no que desencadene una respuesta autoinmune secundaria y que cause una orquitis autoinmune. COVID-19 se ha asociado con anormalidades en la coagulación por lo que la orquitis podría ser el resultado de una vasculitis segmentaria. Los datos disponibles sobre la presencia del virus en semen son contradictorios. Sólo un estudio informó de la presencia de ARN en el 15,8% de enfermos de COVID-19. La presencia de ácido nucleico o antígeno en el semen no implica la existencia de virus con capacidad de replicación o infección. En hombres con COVID-19 se ha observado un incremento significativo de LH en suero y una drástica disminución de la ratio T/LH y FSH/LH, congruente con un hipogonadismo subclínico. Los datos disponibles y los hallazgos de los estudios recientes se basan en tamaños de muestra pequeños y proporcionan informaciones contradictorias. Existe la posibilidad teórica de que pueda producirse daño testicular y posterior infertilidad después de la infección por COVID-19, por lo que especialmente para aquellos hombres en edad reproductiva, se debe sugerir consulta y evaluación de la función gonadal y análisis de semen. En cuanto a la posibilidad de transmisión sexual, no hay evidencia suficiente para respaldar la necesidad de que las parejas asintomáticas eviten las relaciones sexuales para protegerse contra la transmisión del virus. Se necesita más investigación para comprender los impactos a largo plazo del SARS-CoV-2 en la función reproductiva masculina, incluidos sus posibles efectos sobre la fertilidad y la función endocrina testicular

Prokaryotic and viral community of the sulfate‐rich crust from Peñahueca ephemeral lake, an astrobiology analogue

Peñahueca is an athalassohaline hypersaline inland ephemeral lake originated under semiarid conditions in the central Iberian Peninsula (Spain). Its chemical composition makes it extreme for microbial life as well as a terrestrial analogue of other planetary environments. To investigate the persistence of microbial life associated with sulfate‐rich crusts, we applied cultivation‐independent methods (optical and electron microscopy, 16S rRNA gene profiling and metagenomics) to describe the prokaryotic community and its associated viruses. The diversity for Bacteria was very low and was vastly dominated by endospore formers related to Pontibacillus marinus of the Firmicutes phylum. The archaeal assemblage was more diverse and included taxa related to those normally found in hypersaline environments. Several ‘metagenome assembled genomes’ were recovered, corresponding to new species of Pontibacillus, several species from the Halobacteria and one new member of the Nanohaloarchaeota. The viral assemblage, although composed of the morphotypes typical of high salt systems, showed little similarity to previously isolated/reconstructed halophages. Several putative prophages of Pontibacillus and haloarchaeal hosts were identified. Remarkably, the Peñahueca sulfate‐rich metagenome contained CRISPR‐associated proteins and repetitions which were over 10‐fold higher than in most hypersaline systems analysed so far.This research was supported by the Spanish Ministry of Economy projects CLG2015_66686-C3-1 (to RRM) CLG2015_66686-C3-3 (to JA), CGL2015-66455-R (to MAGC, MESM, JPRA), AYA2011-24803 and ESP2015-69540-R (to VP) which were also supported by the European Regional Development Fund and the MDM-2017-0737 Unidad de Excelencia “María de Maeztu”- Centro de Astrobiología (INTA-CSIC)

Taxonomic and functional metagenomic profiling of the microbial community in the anoxic sediment of a sub-saline Shallow Lake (Laguna de Carrizo, Central Spain)

The phylogenetic and functional structure of the microbial community residing in a Ca2+-rich anoxic sediment of a sub-saline shallow lake (Laguna de Carrizo, initially operated as a gypsum (CaSO4 × 2 H2O) mine) was estimated by analyzing the diversity of 16S rRNA amplicons and a 3.1 Mb of consensus metagenome sequence. The lake has about half the salinity of seawater and possesses an unusual relative concentration of ions, with Ca2+ and SO 4 2- being dominant. The 16S rRNA sequences revealed a diverse community with about 22% of the bacterial rRNAs being less than 94.5% similar to any rRNA currently deposited in GenBank. In addition to this, about 79% of the archaeal rRNA genes were mostly related to uncultured Euryarchaeota of the CCA47 group, which are often associated with marine and oxygen-depleted sites. Sequence analysis of assembled genes revealed that 23% of the open reading frames of the metagenome library had no hits in the database. Among annotated genes, functions related to (thio) sulfate and (thio) sulfonate-reduction and iron-oxidation, sulfur-oxidation, denitrification, synthrophism, and phototrophic sulfur metabolism were found as predominant. Phylogenetic and biochemical analyses indicate that the inherent physical–chemical characteristics of this habitat coupled with adaptation to anthropogenic activities have resulted in a highly efficient community for the assimilation of polysulfides, sulfoxides, and organosulfonates together with nitro-, nitrile-, and cyanide-substituted compounds. We discuss that the relevant microbial composition and metabolic capacities at Laguna de Carrizo, likely developed as an adaptation to thrive in the presence of moderate salinity conditions and potential toxic bio-molecules, in contrast with the properties of previously known anoxic sediments of shallow lakes.This research was supported by the Spanish CSD2007-00005 project and FEDER funds. M-E.G. thanks the CSIC for a JAE fellowship.Peer Reviewe

Cross-frequency coupling and phase synchronization in nonlinear acoustics

The Cross-Frequency Coupling (CFC) characterizes the correlation between the phase/amplitude of a low-frequency band with those of a high-frequency band within or across time series. The CFC phenomenon has been observed in a variety of systems: earth seismic waves, stock market fluctuations, pulsatile hormone secretions and in the scale-free activity of the human brain. In this work, experiments were conducted using a liquid-filled spherical chamber arranged in an experimental setup tailored for characterizing the acoustic field developed in typical nonlinear dynamics found in bubbly liquid media, like single/multi-bubble sonoluminescence (SL). The measured time series data were analyzed using signal processing algorithms specialized for quantifying CFC and phase synchronization phenomena. Our results suggest that in absence of bubbles, the excitatory-inhibitory interaction among the acoustic modes of the spherical resonator, coupled via 1:n internal resonances, produces the nonlinear harmonics observed in the system response. On the other hand, it was found that the interaction between the acoustic modes of the spherical resonator with the SL bubble(s) acoustic emission, generates nonlinear harmonics amplitude-modulated by the phase of the fundamental driving frequency in which the overall modulation strength and its variance across multiple time series data depend on the spatial stability of the SLbubble( s).Fil: Dellavale Clara, Hector Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; ArgentinaFil: Rosselló, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentin