Due to the growing capacity of gravitational-wave astronomy and black-hole imaging, we will soon be able to emphatically decide if astrophysical dark objects lurking in galactic centers are black holes. Sgr A*, one of the most prolific astronomical radio sources in our galaxy, is the focal point for tests of general relativity. Current mass and spin constraints predict that the central object of the Milky Way is supermassive and slowly rotating, thus can be conservatively modeled as a Schwarzschild black hole. Nevertheless, the well-established presence of accretion disks and astrophysical environments around supermassive compact objects can significantly deform their geometry and complicate their observational scientific yield. Here, we study extreme-mass-ratio binaries comprised of a minuscule secondary object inspiraling onto a supermassive Zipoy-Voorhees compact object; the simplest exact solution of general relativity that describes a static, spheroidal deformation of Schwarzschild spacetime. We examine geodesics of prolate and oblate deformations for generic orbits and reevaluate the non-integrability of Zipoy-Voorhees spacetime through the existence of resonant islands in the orbital phase space. By including radiation loss with post-Newtonian techniques, we evolve stellar-mass secondary objects around a supermassive Zipoy-Voorhees primary and find clear imprints of non-integrability in these systems. The peculiar structure of the primary, allows for, not only typical single crossings of transient resonant islands, that are well-known for non-Kerr objects, but also inspirals that transverse through several islands, in a brief period of time, that lead to multiple glitches in the gravitational-wave frequency evolution of the binary. The detectability of glitches with future spaceborne detectors can, therefore, narrow down the parameter space of exotic solutions that, otherwise, can cast identical shadows with black holes.

BACKGROUND: Studying chaotic dynamics in fractional- and integer-order dynamical systems has let researchers understand and predict the mechanisms of related non-linear phenomena.
OBJECTIVE: Phase transitions between the fractional- and integer-order cases is one of the main problems that have been extensively examined by scientists, economists, and engineers. This paper reports the existence of chaotic attractors that exist only in the fractional-order case when using the specific selection of parameter values in a new hyperchaotic (Matouk\'s) system.
METHODS: This paper discusses stability analysis of the steady-state solutions, existence of hidden chaotic attractors and self-excited chaotic attractors. The results are supported by computing basin sets of attractions, bifurcation diagrams and the Lyapunov exponent spectrum. These tools verify the existence of chaotic dynamics in the fractional-order case; however, the corresponding integer-order counterpart exhibits quasi-periodic dynamics when using the same choice of initial conditions and parameter set. Projective synchronization via non-linear controllers is also achieved between drive and response states of the hidden chaotic attractors of the fractional Matouk\'s system.
RESULTS: Dynamical analysis and computer simulation results verify that the chaotic attractors exist only in the fractional-order case when using the specific selection of parameter values in the Matouk\'s hyperchaotic system.
CONCLUSIONS: An example of the existence of hidden and self-excited chaotic attractors that appears only in the fractional-order case is discussed. So, the obtained results give the first example that shows chaotic states are not necessarily transmitted between fractional- and integer-order dynamical systems when using a specific selection of parameter values. Chaos synchronization using the hidden attractors\' manifolds provides new challenges in chaos-based applications to technology and industrial fields.

What is the reason for complex dynamical patterns registered from real biological neuronal networks? Noise and dynamical reconfiguring of a network (functional/dynamic connectome) were proposed as possible answers. In this case study, we report a complex dynamical pattern observed in a simple deterministic network of 25 excitatory neurons with fixed connectome. After a short initial stimulation, the network is engaged into a complex dynamics, which lasts for a long time. Eventually, with no external intervention, the dynamics comes to a periodic one with a short period. The long transient is positively checked for being chaotic. We conclude that the complex dynamics observed is the output of neural computation performed in the process of neuronal firings and spikes propagation.

Congenital high airway obstruction syndrome (CHAOS) is a rare life-threatening fetal condition resulting from obstruction of the upper fetal airway which may be partial or complete. Prenatal diagnosis is crucial as it usually results in stillbirth or death after delivery if unrecognized. We report a case of CHAOS that was diagnosed prenatally due to characteristic ultrasound features. We also briefly review literature in light of current management options.

This paper presents and briefly discusses recent observations of dynamics associated with isolated generalized bipolar transistor cells. A mathematical model of this simple system is considered on the highest level of abstraction such that it comprises many different network topologies. The key property of the analyzed structure is its bias point since the transistor is modeled via two-port admittance parameters. A necessary but not sufficient condition for the evolution of autonomous complex behavior is the nonlinear bilateral nature of the transistor with arbitrary reason that causes this effect. It is proved both by numerical analysis and experimental measurement that chaotic motion is miscellaneous, robust, and it is neither numerical artifact nor long transient motion.

Congenital upper airway obstruction syndrome is a rare malformation that can be fatal to a newborn baby. It is defined as a complete or almost complete obstruction of the upper airways. CHAOS rate is unknown. We here report the case of a 24-year-old primiparous patient with no medical or surgical history. First-trimester ultrasound didn\'t show any abnormality. During the second trimester, ultrasonography showed extensive subcutaneous edema, hypertrophied lung with hyperechoic appearance, hypoplastic heart and large-volume ascites associated with severe oligoamnios. After having excluded the most common causes, including isoimmunization (indirect negative Coombs), infections (negative serologies) kariotiping was not performed because the patient refused it. The results of ultrasonography suggested fetal hydrops secondary to CHAOS syndrome, because of pathognomonic signs of pulmonary hypertrophy with inverted or convex diaphragm. MRI was requested; it suggested CHAOS syndrome associated with other malformations: laryngeal atresia, microphthalmia with hypertelorism and deviation of the nasal septum with lack of visualization of the thymic tissue, no clear identification of the bladder, absence of right kidney and hypoplastic left kidney. The outcome of pregnancy was marked by premature labour at the 24th week of amenorrhea. The baby had a birth weight of 1475g, polimalformations such as sexual ambiguity, distended abdomen and polydactyly . The newborn died 3 min after birth. Karyotyping was performed which showed 46XX.

Congenital high airway obstruction syndrome (CHAOS) is a rare life-threatening fetal condition resulting from obstruction of the upper fetal airway which may be partial or complete. Prenatal diagnosis is crucial as it usually results in stillbirth or death after delivery if unrecognized. We report a case of CHAOS that was diagnosed prenatally due to characteristic ultrasound features. We also briefly review literature in light of current management options.

Background: Congenital high airway obstruction syndrome (CHAOS) is a near fatal condition, except when the ex utero intrapartum treatment (EXIT) procedure is performed as rescue. After antenatal diagnosis of the condition, counseling regarding prognosis and outcome needs to be provided.Case: We describe here a case with CHAOS due to isolated fetal laryngeal atresia, presented at our center at 33-week gestation. After counseling regarding the uncertain outcome, consent for elective caesarean was not given. Intact cord resuscitation (ICR) was done as a rescue by a well-coordinated team during delivery. Tracheostomy was performed successfully under local anesthesia within five minutes, while the cord was still attached to the placenta. The baby had supraglottic stenosis on CT scan. Reconstructive surgery is planned after 8 months. The literature review showed 24 reports of 28 cases with intrinsic airway obstruction managed by EXIT, laryngeal atresia was the most common cause (18/28). The outcome was poor in tracheal agenesis (1/4 survived) whereas those having laryngeal web or small communication (4/4 survived) had better outcome. Tracheal reconstruction was done in 3/28 cases only.Conclusions: The case emphasizes that ICR and tracheostomy during vaginal delivery can rescue the baby. The literature reviewed provided insight into the outcome of CHAOS cases in world literature.

BACKGROUND: Congenital High Airway Obstruction Syndrome (CHAOS) is a rare anomaly where a partial or complete obstruction of upper airway is seen. As a consequence, the foetus develops enlarged lungs, inverted or flattened diaphragm and ascites. The pathological findings in a case of CHAOS is presented.
METHODS: A 28-year-old primigravida presented with a history of 5 months of amenorrhoea. Ultrasonography revealed enlarged echogenic lungs, cardiac mid-position, inverted diaphragm, foetal ascites and talipes of left foot. The parents opted for termination of pregnancy. Foetal autopsy revealed a male foetus with ascites and talipes of left foot. Lungs were massively enlarged, diaphragm was flattened. A dome-shaped cricoid cartilage at the subglottic level was seen as the cause of obstruction.
CONCLUSIONS: CHAOS is a rare anomaly. A foetal autopsy can be helpful in establishing the level and nature of the obstruction and in documenting other associated foetal anomalies.

In this case, we describe a newborn with prenatal diagnosis of congenital high airway obstruction syndrome (CHAOS), successfully managed with a cesarean section with delayed cord clamping 180 seconds. In case of prenatal diagnosis of CHAOS, prompt airway intervention at delivery allows survival of this otherwise fatal condition. Ex utero intrapartum treatment (EXIT) is considered the elective procedure to secure the fetal airway before the baby is completely separated from the maternal circulation. In cases where the EXIT procedure is not possible for maternal reasons (Ballantyne\'s syndrome), delayed cord clamping may serve as an alternative method to manage CHAOS.