Phase separation in coupled chaotic maps on fractal networks

The phase ordering dynamics of coupled chaotic maps on fractal networks are investigated. The statistical properties of the systems are characterized by means of the persistence probability of equivalent spin variables that define the phases. The persistence saturates and phase domains freeze for all values of the coupling parameter as a consequence of the fractal structure of the networks, in contrast to the phase transition behavior previously observed in regular Euclidean lattices. Several discontinuities and other features found in the saturation persistence curve as a function of the coupling are explained in terms of changes of stability of local phase configurations on the fractals.Comment: (4 pages, 4 Figs, Submitted to PRE

Pattern Formation on Trees

Networks having the geometry and the connectivity of trees are considered as the spatial support of spatiotemporal dynamical processes. A tree is characterized by two parameters: its ramification and its depth. The local dynamics at the nodes of a tree is described by a nonlinear map, given rise to a coupled map lattice system. The coupling is expressed by a matrix whose eigenvectors constitute a basis on which spatial patterns on trees can be expressed by linear combination. The spectrum of eigenvalues of the coupling matrix exhibit a nonuniform distribution which manifest itself in the bifurcation structure of the spatially synchronized modes. These models may describe reaction-diffusion processes and several other phenomena occurring on heterogeneous media with hierarchical structure.Comment: Submitted to Phys. Rev. E, 15 pages, 9 fig

On Exact and Approximate Solutions for Hard Problems: An Alternative Look

We discuss in an informal, general audience style the da Costa-Doria conjecture about the independence of the P = NP hypothesis and try to briefly assess its impact on practical situations in economics. The paper concludes with a discussion of the Coppe-Cosenza procedure, which is an approximate, partly heuristic algorithm for allocation problems.P vs. NP , allocation problem, assignment problem, traveling salesman, exact solution for NP problems, approximate solutions for NP problems, undecidability, incompleteness

Occurrence and transformation of illicit drugs in wastewater treatment plants.

Illicit drugs (IDs) and their metabolites have been recently recognized as a new group of water emerging contaminants (ECs) with potent psychoactive properties and unknown effects to the aquatic environment (Pal et al., 2013). IDs are excreted via urine and feces and arrive at wastewater treatment plants (WWTPs) where can reach ppb levels (Castiglioni et al., 2006). Over the past few years, it has been demonstrated that conventional biological processes in WWTPs are not or scarcely able to remove IDs. Thus, they are discharged into water bodies through the treated effluent (Postigo et al., 2011). Therefore, monitoring the IDs concentration in WWTPs can have a twofold advantage: i. increase knowledge on the amount of IDs discharged in the environment and estimate their effect; ii. estimating indirectly the community level consumption (Senta et al., 2014). The objective of this paper is to provide a comprehensive analysis of the occurrence and behaviour of illicit drugs and their metabolites in two Sicilian WWTPs. Specifically, two WWTPs (namely, WWTP-1 and WWTP-2) located at the north-western Sicilian coast have been monitored for 5 months (one sampling per week). The two WWTPs have a conventional scheme and mainly differ for their potentiality. Indeed, the average daily flow expressed as m3d-1 for WWTP-1 and WWTP-2 was equal to 153,600 and 19,704, respectively. Samples were analyzed for total suspended solids (TSS), illicit drugs and their metabolites (metham-phetamine; COC = cocaine; MDMA = 3,4-methylenedioxymethamphetamine; METH = methadone; EDDP = 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine; MDA = 3,4-methylenedioxy amphetamine; MDEA = 3,4-methylenedioxy ethylamphetamine; THC-COOH = 11-nor-9-carboxy-\u3949-tetrahydrocannabinol; BEG= Benzoylecgonine). In order to provide a fast and sensitive approach to quantify IDs, an automated online sample preparation method has been developed. The method uses a Thermo Scientific Transcend TLX-1 system powered by TurboFlowTM technology coupled with a TSQ Quantiva Triple Quadrupole Mass Spectrometer. Specifically, THC-COOH has been extracted from 75 \ub5L of pre-filtered water (using 7 and 0.4 \ub5m paper filters) by an online sample extraction method and quantified using an isotopic dilution approach between 30 and 2000 ng L-1

Periodic Neural Activity Induced by Network Complexity

We study a model for neural activity on the small-world topology of Watts and Strogatz and on the scale-free topology of Barab\'asi and Albert. We find that the topology of the network connections may spontaneously induce periodic neural activity, contrasting with chaotic neural activities exhibited by regular topologies. Periodic activity exists only for relatively small networks and occurs with higher probability when the rewiring probability is larger. The average length of the periods increases with the square root of the network size.Comment: 4 pages, 5 figure

Generalized synchronization of chaos in autonomous systems

We extend the concept of generalized synchronization of chaos, a phenomenon that occurs in driven dynamical systems, to the context of autonomous spatiotemporal systems. It means a situation where the chaotic state variables in an autonomous system can be synchronized to each other but not to a coupling function defined from them. The form of the coupling function is not crucial; it may not depend on all the state variables nor it needs to be active for all times for achieving generalized synchronization. The procedure is based on the analogy between a response map subject to an external drive acting with a probability p and an autonomous system of coupled maps where a global interaction between the maps takes place with this same probability. It is shown that, under some circumstances, the conditions for stability of generalized synchronized states are equivalent in both types of systems. Our results reveal the existence of similar minimal conditions for the emergence of generalized synchronization of chaos in driven and in autonomous spatiotemporal systems.Comment: 5 pages, 7 figures, accepted in PR

Shifting paradigms in two common abdominal surgical emergencies during the pandemic

During the pandemic there was a reduction in access to the hospital and surgical treatment of appendicitis and cholecystitis at a global level. Some strategies adopted during this challenging time could be applied even after the emergency has been controlled

Water resource recovery facilities (Wrrfs): The case study of palermo university (Italy)

The wastewater sector paradigm is shifting from wastewater treatment to resource recovery. In addition, concerns regarding sustainability during the operation have increased. In this sense, there is a need to break barriers (i.e., social, economic, technological, legal, etc.) for moving forward towards water resource recovery facilities and demonstration case studies can be very effective and insightful. This paper presents a new water resource recovery case study which is part of the Horizon 2020 EU Project “Achieving wider uptake of water-smart solutions—Wider Uptake”. The final aim is to demonstrate the importance of a resource recovery system based on the circular economy concept. The recovery facilities at Palermo University (Italy) are first presented. Afterwards, the resource recovery pilot plants are described. Preliminary results have underlined the great potential of the wastewater treatment plant in terms of resources recovery and the central role of the University in fostering the transition towards circular economy. The fermentation batch test highlighted a volatile fatty acids (VFAs) accumulation suitable for polyhydroxyalkanoates (PHAs) production. The results of static adsorption and desorption tests showed that the highest amount of adsorbed NH4+ was recorded for untreated and HCl-Na treated clinoptilolite

The effects of dietary counseling on children with food allergy: a prospective, multicenter intervention study.

Although dietary counseling is generally recommended in children with food allergy (FA), its effect on the nutritional status of these patients has not yet been evaluated. Our nonrandomized multicenter prospective intervention study was undertaken to investigate the effects of dietary counseling on children with FA. Anthropometric data, dietary intakes, and laboratory biomarkers of nutritional status were evaluated in children with FA (aged 6 to 36 months) before and after dietary counseling, by multidisciplinary teams composed of pediatricians, dietitians, and nurses. Ninety-one children with FA (49 boys and 42 girls; mean age 18.9 months, 95% CI 16.5 to 21.3) were evaluated; 66 children without FA (41 boys and 25 girls; mean age 20.3 months, 95% CI 17.7 to 22.8) served as controls providing baseline values only. At enrollment, energy and protein intakes were lower in children with FA (91 kcal/kg/day, interquartile range [IQR]=15.1, minimum=55.2, maximum=130.6; and 2.2 g/kg/day, IQR=0.5, minimum=1.5, maximum=2.7, respectively) than in children without FA (96 kcal/kg/day, IQR=6.1, minimum=83.6, maximum=118.0; and 4.6 g/kg/day, IQR=1.2, minimum=2.0, maximum=6.1, respectively; P<0.001). A weight to length ratio <2 standard deviations was more frequent in children with FA than in children without FA (21% vs 3%; P<0.001). At 6 months following dietary counseling, the total energy intake of children with FA was similar to the baseline values of control children. Dietary counseling also resulted in a significant improvement of their anthropometric and laboratory biomarkers of nutritional status. The results of our study support the crucial role of dietary counseling in the clinical management of children with FA