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This article is part of the theme issue 'Vibrational and stochastic resonance in driven nonlinear systems (part 1)'.We consider a two-level quantum system interacting with two classical time-periodic electromagnetic fields. The frequency of one of the fields far exceeds that of the other. The effect of the high-frequency field can be averaged out of the dynamics to realize an effective transition frequency of the field-dressed two-level system. We examine the linear response, second harmonic response and Stokes and anti-Stokes Raman response of the dressed two-level system, to the weak frequency field. The vibrational resonance enhancement in each case is demonstrated for optimal strength of the high-frequency field. Our theoretical scheme is corroborated by full numerical simulation of the two-level, two-field dynamics governed by loss-free Bloch equations. We suggest that quantum optics can offer an interesting arena for the study of the vibrational resonance. This article is part of the theme issue 'Vibrational and stochastic resonance in driven nonlinear systems (part 1)'.The dynamic system described by a finite number of first-order differential equations is considered. The right side of each equation is a sum of a slow, deterministic and, in the general case, nonlinear function of dynamic variables and a stochastic excitation. The stochastic action is a superposition of a finite number of independent random processes with coefficients depending on dynamic variables and slow time. The problem statement is oriented to applications in the field of driven systems. The analysis is based on the concept of vibration mechanics proposed by I. I. Blekhman. The modified method of direct separation of slow and fast motions uses the explicit introduction of a small parameter and some ideas of the two-scale technique. The general formulas for vibrational forces (or fluxes) are obtained. These additional terms appear in the resulting system for averaged motion instead of the stochastic terms to make the averaged system equivalent to the initial stochastic system with respect to slow motions and, in particular, to low-frequency resonances. As an example, the model of a vibration machine for bulk material processing is considered. The stochastic effect is caused by random oscillations of the bulk material mass. It is transformed into a modification of the machine's frequency characteristics leading to a specific stochastic resonance. This article is part of the theme issue 'Vibrational and stochastic resonance in driven nonlinear systems (part 1)'.Combined effects of the damping and forcing in the underdamped time-delayed Duffing oscillator are considered in this paper. We analyse the generation of a certain damping-induced unpredictability due to the gradual suppression of interwell oscillations. We find the minimal amount of the forcing amplitude and the right forcing frequency to revert the effect of the dissipation, so that the interwell oscillations can be restored, for different time delay values. This is achieved by using the delay-induced resonance, in which the time delay replaces one of the two periodic forcings present in the vibrational resonance. A discussion in terms of the time delay of the critical values of the forcing for which the delay-induced resonance can tame the dissipation effect is finally carried out. CL-82198 price This article is part of the theme issue 'Vibrational and stochastic resonance in driven nonlinear systems (part 1)'.This paper reports the stochastic resonance (SR) phenomenon with memory effects for a Brownian particle in a potential whose shape is subjected to deformation. We model the deformation in the system by the Remoissenet-Peyrard potential and the memory effects by the time-delayed feedback. The question of the possible influence of time-delayed feedback on the occurrence of SR is then of our interest. We examine numerically the effect of feedback strength as well as time delay on SR phenomenon in terms of hysteresis loop area. It is found that time-delayed feedback has a significant effect on SR and can induce double resonances in the system. We show that the properties of SR are varying, depending on interdependence between feedback strength, time delay and shape parameter. This article is part of the theme issue 'Vibrational and stochastic resonance in driven nonlinear systems (part 1)'.The paper presents the results of the experimental study of an application of the phenomenon of vibrational resonance (VR) for enhancement of the response of a bistable vertical-cavity surface-emitting laser (VCSEL) to the effect of optical modulating signals. Specifically, two different cases were investigated (a) the control of all-optical switching caused by a modulated orthogonal optical injection from another VCSEL and (b) the amplification of autodyne signals from a vibrating diffusely reflecting surface in the self-mixing optical interferometry. It is experimentally demonstrated that an application of the phenomenon of VR in both cases studied leads to a strong amplification of the input optical signals by a factor from 10 to 200 depending on the experimental conditions with respect to the initial values. The effect of the asymmetry of a bistable potential on the amplification factor was also studied. The results obtained can be used to improve all-optical switchings for application in communication systems and enhancement of autodyne signals in self-mixing optical interferometry. This article is part of the theme issue 'Vibrational and stochastic resonance in driven nonlinear systems (part 1)'.Background In critically ill children, sepsis-associated acute kidney injury (SA-AKI) has significant morbidity and mortality.Aim To estimate whether early initiation of peritoneal dialysis (PD) has a better short-term outcome than standard PD.Methods Early PD (n = 25) was defined as a need for PD in Kidney Disease Improving Global Outcomes (KDIGO) stage 2 AKI, while those fulfilling the criteria for stage 3 KDIGO were categorised as a standard PD group (n = 25). The primary outcome measure was the estimated glomerular filtration rate (eGFR) at discharge or at 4 weeks after initiation of PD, whichever occurred earlier.Results A prospective cohort of 50 children (32 boys) aged 2 months to 16 years with SA-AKI who underwent PD were recruited. The most frequent indication for PD was fluid overload (40%), followed by persistent metabolic acidosis (36%). Children in the early PD group had lower creatinine and higher eGFR at discharge/4-week follow-up (p less then 0.001). The duration of PD was less if it was coment therapy; SA-AKI sepsis-associated acute kidney injury; SYL Saving Young Lives; SOFA sequential (sepsis-related) organ failure assessment score; STARRT-AKI standard versus accelerated initiation of renal replacement therapy in acute kidney injury.Animal-origin food has been suggested as the main dietary source of perfluorinated alkylated substances (PFASs) for humans, and pork liver is a major contributor. The nationwide survey data of PFASs from pork liver in China was limited. This study determined 17 PFASs in pork liver samples from 30 regions including different provinces, autonomous regions and municipalities, using traditional high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The average detection rate of PFASs (≥the limit of detection, LOD) in pork liver samples throughout China reached 97.4%, with ΣPFASs of 1.80 μg/kg. Both in areas with well-developed manufacturing industries and in non-production areas of perfluorinated compounds, PFASs were widely detectable in pork liver samples, especially for perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS). The detection rates of PFOA and PFOS (≥LOD) were 77.0% and 86.1%, with contents of 0.160 μg/kg and 0.397 μg/kg. The risk assessments of PFOA and PFOS from pork liver for different populations demonstrated the necessity for continuous exposure monitoring and risk investigation of PFASs. This work accomplished systematic and nationwide determination data of PFASs in pork liver, and provides a valuable reference for contamination monitoring and risk assessment of PFASs from animal origin food.We investigated the representation and breakdown of verb knowledge employing different syntactic and semantic classes of verbs in a group of individuals with probable Alzheimer's Disease (pAD). In an action naming task with coloured photographs (Fiez & Tranel, 1997. Standardized stimuli and procedures for investigating the retrieval of lexical and conceptual knowledge for action. Memory and Cognition, 25(4), 543-569. https//doi.org/10.3758/BF03201129), pAD individuals were impaired for naming actions compared to objects. Verb tense was also affected, with simple-past (e.g., chopped) being more difficult to name than the gerundial form (e.g., chopping). Employing action-naming with short movies depicting events and states, we contrasted three verb classes based on their hypothetical structural and semantic/conceptual properties argument structure, thematic structure, and conceptual templates. The three classes were causatives (peel), verbs of perception (hear), and verbs of motion (run) Overall, results suggest that individuals with pAD are selectively impaired for verb tense and thematic assignment, but not conceptual-template complexity. Methodologically, we also show that dynamic scenes are more ecologically valid than static scenes to probe verb knowledge in AD.Experiential avoidance, dissociation, and guilt have been shown to be associated with trauma exposure and to play an important role in explaining the development and maintenance of posttraumatic stress symptoms. However, there is a lack of studies that simultaneously address the relationship between these variables, which has never been studied within the framework of emotional processing theory. Furthermore, gender differences in traumatic victimization, posttraumatic stress symptoms, experiential avoidance, dissociation, and guilt have also been reported. Therefore, this study had a double aim a) to assess the mediating roles of dissociation and guilt in the relationship between experiential avoidance and posttraumatic stress symptoms; and b) to investigate whether gender moderates any such relationship. The final sample comprised 683 undergraduate students (150 men and 533 women) with a history of exposure to traumatic events and with posttraumatic stress symptoms. Mediation and moderated mediation analyses were conducted. Dissociation and guilt independently mediated the association between experiential avoidance and posttraumatic stress symptoms however, this mediation effect was not moderated by gender. The findings suggest that interventions aimed at controlling psychological variables linked to PTSD (i.e. experiential avoidance, dissociation, and guilt) may be of help to both men and women.The disease caused by the new coronavirus, initially described in China in December 2019, became known as coronavirus disease 2019 and quickly spread to countries on all continents, becoming a pandemic with an important global impact. Despite being a virus that typically affects the respiratory tract, some studies have already described neurological manifestations associated with this infection, including acute ischaemic vascular insult. We report a case series including 30 patients, who presented with neurological symptoms during admission to our service, being diagnosed with ischaemic stroke and, concomitantly, coronavirus disease 2019. In the subgroup of patients analysed, a state of hypercoagulability and pro thrombosis was observed through laboratory tests, probably related to the cytokine storm syndrome associated with infection by this virus. With that, we discussed the possibility of this finding being an aggravating factor in the occurrence of stroke in these patients.