This interdisciplinary study critically analyzes current research, establishing a profound connection between sea water, sea ice, sea temperature, and surface temperature through a 4D hyperchaotic Caputo fractional differential equation. Emphasizing the collective impact on climate, focusing on challenges from anthropogenic global warming, the study scrutinizes theoretical aspects, including existence and uniqueness. Two sliding mode controllers manage chaos in this 4D fractional system, assessed amid uncertainties and disruptions. The global stability of these controlled systems is also confirmed, considering both commensurate and non-commensurate 4D fractional order. To demonstrate the intricate chaotic motion within the system, we employ the Lyapunov exponent and Poincare sections. Numerical simulations are conducted by using the predictor-corrector method. The effects of surface temperature on chaotic dynamics are discussed. The crucial role of sea ice reflection in climate stability is highlighted in two scenarios. Correlation graphs, comparing model and observational data using the predictor-corrector method, enhance the proposed 4D hyperchaotic model\'s credibility. Subsequently, numerical simulations validate theoretical assertions about the controllers\' influence. These controllers indicate which variable significantly contributes to controlling the chaos.

The multi-particle Arnol\'d cat is a generalization of the Hamiltonian system, both classical and quantum, whose period evolution operator is the renowned map that bears its name. It is obtained following the Joos-Zeh prescription for decoherence by adding a number of scattering particles in the configuration space of the cat. Quantization follows swiftly if the Hamiltonian approach, rather than the semiclassical approach, is adopted. The author has studied this system in a series of previous works, focusing on the problem of quantum-classical correspondence. In this paper, the dynamics of this system are tested by two related yet different indicators: the time autocorrelation function of the canonical position and the out-of-time correlator of position and momentum.

The remarkable signal-detection capabilities of the auditory and vestibular systems have been studied for decades. Much of the conceptual framework that arose from this research has suggested that these sensory systems rest on the verge of instability, near a Hopf bifurcation, in order to explain the detection specifications. However, this paradigm contains several unresolved issues. Critical systems are not robust to stochastic fluctuations or imprecise tuning of the system parameters. Further, a system poised at criticality exhibits a phenomenon known in dynamical systems theory as critical slowing down, where the response time diverges as the system approaches the critical point. An alternative description of these sensory systems is based on the notion of chaotic dynamics, where the instabilities inherent to the dynamics produce high temporal acuity and sensitivity to weak signals, even in the presence of noise. This alternative description resolves the issues that arise in the criticality picture. We review the conceptual framework and experimental evidence that supports the use of chaos for signal detection by these systems, and propose future validation experiments.

BACKGROUND: The Confusion, Hubbub, and Order Scale (CHAOS in English Version) was originally developed in the USA by Matheny et al (Bringing order out of chaos: psychometric characteristics of the confusion, hubbub, and order scale. Journal of Applied Developmental Psychology 16(3):429-444, 1995) to measure chaos in the family environment, characterized by confusion, lack of routine, and organization.
OBJECTIVE: To present evidence of content validity, internal structure validity, and validity based on relationships with external measures of an adapted version of the CHAOS into Brasilian Portuguese with adolescents sample in São Paulo - Brasil.
METHODS: Study 1 involved the translation/back-translation and adaptation of the scale into Brazilian Portuguese [here named \"Escala de Confusão, Alvoroço e Ordem no Sistema familiar\" (CAOS)], assessed by 5 judges. In Study 2, we conducted an exploratory factor analyses (EFA) to determine the scale\'s factor structure (N = 180 adults). In Study 3, we carried out confirmatory factor analyses (CFA) to confirm the internal validity of the scale, along with complete structural equation modeling to explore convergent validity in another sample (N = 239 adolescents).
RESULTS: The CAOS scale displayed content validity, and the EFA and CFA showed a unifactorial structure (with some scale adjustments) with an acceptable fit. The family chaos latent factor was associated with externalizing symptoms and perceived stress in adolescents.
CONCLUSIONS: Overall, the Brazilian version of the scale presented evidence of construct, internal, and concurrent validity that indicate its usefulness in Brazil.

This research paper investigates discrete predator-prey dynamics with two logistic maps. The study extensively examines various aspects of the system\'s behavior. Firstly, it thoroughly investigates the existence and stability of fixed points within the system. We explores the emergence of transcritical bifurcations, period-doubling bifurcations, and Neimark-Sacker bifurcations that arise from coexisting positive fixed points. By employing central bifurcation theory and bifurcation theory techniques. Chaotic behavior is analyzed using Marotto\'s approach. The OGY feedback control method is implemented to control chaos. Theoretical findings are validated through numerical simulations.

Compression systems based electromechanical actuators require a good understanding of their dynamics for a better performance. This paper deals with the study of the nonlinear dynamics of an electromechanical system with two rotating arms subjected to a sinusoidal excitation for fluid compression purposes. The physical model integrating two balloons to be compressed by the arms alternately is presented and the mathematical equations traducing their dynamics are established. We emphasize on the influence of some control parameters namely the supply voltage, the discontinuity position and the viscoelastic ratio on the behaviour of the angular displacement of the arms. The study is also done by neglecting the inductance in the electrical part of the system. It is obtained that while the arms exhibit periodic motion during regular movement, compression of the balloons induces a shift to multi-periodic or chaotic dynamics, occasionally reverting to periodicity. Experimental and numerical simulation results demonstrate good agreement, with the R-system approximating more experimental outcomes than the RL-system. These findings hold significant implications for various environmental applications utilizing pump technology.

Cavity optomechanics provides a powerful platform for observing many interesting classical and quantum nonlinear phenomena due to the radiation-pressure coupling between its optical and mechanical modes. In particular, the chaos induced by optomechanical nonlinearity has been of great concern because of its importance both in fundamental physics and potential applications ranging from secret information processing to optical communications. This review focuses on the chaotic dynamics in optomechanical systems. The basic theory of general nonlinear dynamics and the fundamental properties of chaos are introduced. Several nonlinear dynamical effects in optomechanical systems are demonstrated. Moreover, recent remarkable theoretical and experimental efforts in manipulating optomechanical chaotic motions are addressed. Future perspectives of chaos in hybrid systems are also discussed.

This paper describes a novel 4-D hyperchaotic system with a high level of complexity. It can produce chaotic, hyperchaotic, periodic, and quasi-periodic behaviors by adjusting its parameters. The study showed that the new system experienced the famous dynamical property of multistability. It can exhibit different coexisting attractors for the same parameter values. Furthermore, by using Lyapunov exponents, bifurcation diagram, equilibrium points\' stability, dissipativity, and phase plots, the study was able to investigate the dynamical features of the proposed system. The mathematical model\'s feasibility is proved by applying the corresponding electronic circuit using Multisim software. The study also reveals an interesting and special feature of the system\'s offset boosting control. Therefore, the new 4D system is very desirable to use in Chaos-based applications due to its hyperchaotic behavior, multistability, offset boosting property, and easily implementable electronic circuit. Then, the study presents a voice encryption scheme that employs the characteristics of the proposed hyperchaotic system to encrypt a voice signal. The new encryption system is implemented on MATLAB (R2023) to simulate the research findings. Numerous tests are used to measure the efficiency of the developed encryption system against attacks, such as histogram analysis, percent residual deviation (PRD), signal-to-noise ratio (SNR), correlation coefficient (cc), key sensitivity, and NIST randomness test. The simulation findings show how effective our proposed encryption system is and how resilient it is to different cryptographic assaults.

Three-phase induction motors are widely used in various industrial sectors and are responsible for a significant portion of the total electrical energy consumed. To ensure their efficient operation, it is necessary to apply control systems with specific algorithms able to estimate rotation speed accurately and with an adequate response time. However, the angular speed sensors used in induction motors are generally expensive and unreliable, and they may be unsuitable for use in hostile environments. This paper presents an algorithm for speed estimation in three-phase induction motors using the chaotic variable of maximum density. The technique used in this work analyzes the current signals from the motor power supply without invasive sensors on its structure. The results show that speed estimation is achieved with a response time lower than that obtained by classical techniques based on the Fourier Transform. This technique allows for the provision of motor shaft speed values when operated under variable load.

UNASSIGNED: Computerised hexapod-assisted orthopaedic surgery (CHAOS) is a method by which complex multiplanar, multilevel deformity can be corrected with a high degree of accuracy utilising minimally invasive techniques within a single operative event. This study\'s aim was to report the reliability, accuracy and magnitude of correction achieved, alongside patient-reported outcomes and risk factors for complications when using the CHAOS technique throughout the lower limb.
UNASSIGNED: Retrospective review of medical records and radiographs for consecutive patients who underwent CHAOS for lower limb deformity correction at a tertiary centre between 2012 and 2020.
UNASSIGNED: There were 70 cases in 56 patients, with the site of surgery being the femur in 48 cases, proximal tibia in 17 and distal tibia in 5 cases. Multiplanar correction was performed in 43 cases, and multilevel osteotomy was undertaken in 23 cases. Fixation was undertaken with intramedullary nailing (IMN) in 49 cases and locked plates in 21.The maximum corrections were 40° rotation, 20° coronal angulation, 51° sagittal angulation and 62-mm mechanical axis deviation (MAD). Deformity correction was mechanically satisfactory in all patients bar one who was undercorrected requiring revision. The mean patient global impression of change (PGIC) score was 6.2 out of 7.Overall complication rate was 12/70 (17%). Complications from femoral surgery included two nonunions, one case of undercorrection, one case of stiffness, one muscle hernia and one pulmonary embolism. Complications from tibial surgery were one compartment syndrome, one pseudoaneurysm of the anterior tibial artery requiring stenting, one transient neurapraxia of the common peroneal nerve, one locking plate fatigue failure, one seroma and one superficial wound infection.
UNASSIGNED: Computerised hexapod-assisted orthopaedic surgery can be used for accurate correction of complex multilevel and multiplanar deformities of both the femur and tibia. The risk profile appears to differ between femoral and tibial surgeries, and also to that of traditional circular frame correction. Patients remain highly satisfied with both the functional and symptomatic outcomes.
UNASSIGNED: French JMR, Filer J, Hogan K, et al. Computer Hexapod-assisted Orthopaedic Surgery for the Correction of Multiplanar Deformities throughout the Lower Limb. Strategies Trauma Limb Reconstr 2024;19(1):9-14.