Effect of Chaotic Noise on Multistable Systems

In a recent letter [Phys.Rev.Lett. {\bf 30}, 3269 (1995), chao-dyn/9510011], we reported that a macroscopic chaotic determinism emerges in a multistable system: the unidirectional motion of a dissipative particle subject to an apparently symmetric chaotic noise occurs even if the particle is in a spatially symmetric potential. In this paper, we study the global dynamics of a dissipative particle by investigating the barrier crossing probability of the particle between two basins of the multistable potential. We derive analytically an expression of the barrier crossing probability of the particle subject to a chaotic noise generated by a general piecewise linear map. We also show that the obtained analytical barrier crossing probability is applicable to a chaotic noise generated not only by a piecewise linear map with a uniform invariant density but also by a non-piecewise linear map with non-uniform invariant density. We claim, from the viewpoint of the noise induced motion in a multistable system, that chaotic noise is a first realization of the effect of {\em dynamical asymmetry} of general noise which induces the symmetry breaking dynamics.Comment: 14 pages, 9 figures, to appear in Phys.Rev.

Validation of the International Trauma Questionnaire – Child and Adolescent Version (ITQ-CA) in a Chinese mental health service seeking adolescent sample

Background. The International Trauma Questionnaire – Child and Adolescent version (ITQ-CA) is a self-report measure that assesses posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) based on the diagnostic formulation of the 11th version of the International Classification of Diseases (ICD-11). This study aimed to provide a Chinese translation and psychometric evaluation of the ITQ-CA using a sample of mental-health service seeking adolescents in Mainland China. Methods. The ITQ-CA was translated and back-translated from English to simplified Chinese and finalized with consensus from an expert panel. Adolescents ages 12-17 were recruited via convenience sampling from an outpatient psychiatric clinic in Mainland China. Participants completed the ITQ-CA; measures of four criterion variables (depression, anxiety, stress, adverse childhood experiences); and the PTSD Checklist for DSM-5 (PCL-5). Construct validity, concurrent validity, and comparison of PTSD caseness between ICD-11 and DSM-5 measures were assessed. Results. The final sample consisted of 111 Chinese adolescents (78% female; mean age of 15.23), all diagnosed with a major depressive disorder. Confirmatory factor analysis indicated the two-factor second-order model provided optimal fit. All criterion variables were positively and significant correlated with the six ITQ-CA symptom cluster summed scores. In the present sample, 69 participants (62.16%) met symptom criteria for ICD-PTSD or CPTSD using the ITQ-CA, and 73 participants (65.77%) met caseness for DSM-5 PTSD using the PCL-5. Rates of PTSD symptom cluster endorsement and caseness deriving from both diagnostic systems were comparable. Conclusions. The Chinese ITQ-CA has acceptable psychometric properties and confers additional benefits in identifying complex presentations of trauma-related responses in younger people seeking mental health services

AEROgui: A graphical user interface for the optical properties of aerosols

Atmospheric aerosols have an uncertain effect on climate and serious impacts on human health. The uncertainty in the aerosols' role on climate has several sources. First, aerosols have great spatial and temporal variability. The spatial variability arises from the fact that aerosols emitted in a certain place can travel thousands of kilometers, swept by the winds to modify the destination region's climate. The spatial variability also means that aerosols are inhomogeneously distributed in the vertical direction, which can lead to a differential effect on the energy balance depending on the aerosols' altitude. On the other hand, aerosols experience physical and chemical transformations in the time they spend in the atmosphere, commonly known as aging, which modifies its optical properties. These factors make necessary the use of two approaches for the study of the aerosol impact on climate: global aerosol models and satellite- and ground-based measurements. The disagreement between the estimates of the two approaches is the main cause of the climate uncertainty. One way to reduce climate uncertainty is to create new tools to simulate more realistic aerosol scenarios. We present a graphical user interface to obtain aerosol optical properties: extinction, scattering, and absorption coefficients; single-scattering albedo; asymmetry parameter; and aerosol optical depth. The tool can be used to obtain the optical properties of the external and internal mixture of several aerosol components. Interface outputs have successfully been compared to a black carbon plume and to aging mineral dust

Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory

The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal

SENSITIZATION TO KAPPA OPIOID MECHANISMS ASSOCIATED WITH TOLERANCE TO THE ANORECTIC EFFECTS OF CATHINONE

To evaluate the possibility that tolerance to the anorectic effects of cathinone (CATH), an amphetamine-like compound, involves the sensitization of endogenous kappa opioid mechanisms, the influence of chronic treatment with CATH on the effects of the selective kappa opioid agonist U50488H (U50) on food and water intake was evaluated in rats. Since kappa agonists specifically increase urine output, the interaction between CATH and U50 on this physiological function was also evaluated. Acutely, CATH produced anorexia and diuresis, whereas water intake was not affected. U50 resulted in an increase in both food and water intake as well as urine output. After 9 days of daily CATH, tolerance to its anorectic effects had developed. In addition, water intake, which was not affected acutely by CATH, was significantly enhanced with respect to controls treated daily with water. In a group treated chronically with U50, its diuretic effect was unchanged, but water intake was no longer increased after 9 days of treatment. Food intake in this group remained higher than control intake for at least 19 days, but this hyperphagic effect was not detectable on day 34. On days 10 and 20 of the chronic regimen, the administration of U50 to the chronic CATH group resulted in a doubling of the hyperphagic response to U50, and this effect was naloxone-reversible. Water intake was also increased but to a lesser extent. The diuretic effect of U50 did not appear to be influenced by chronic CATH administration. Despite sensitization to the hyperphagic effects of U50 in the chronic CATH group, 3H-bremazocine binding to crude synaptosomal membranes of whole brain did not differ between chronically water-, CATH-, or U50-treated animals. These results suggest that tolerance to the anorectic effects of an amphetamine-like agent is associated with a sensitization to kappa-opiate mediated activation of feeding