Markov-modulated model for landing flow dynamics: An ordinal analysis validation.

Air transportation is a complex system characterized by a plethora of interactions at multiple temporal and spatial scales; as a consequence, even simple dynamics like sequencing aircraft for landing can lead to the appearance of emergent behaviors, which are both difficult to control and detrimental to operational efficiency. We propose a model, based on a modulated Markov jitter, to represent ordinal pattern properties of real landing operations in European airports. The parameters of the model are tuned by minimizing the distance between the probability distributions of ordinal patterns generated by the real and synthetic sequences, as estimated by the Permutation Jensen-Shannon Distance. We show that the correlation between consecutive hours in the landing flow changes between airports and that it can be interpreted as a metric of efficiency. We further compare the dynamics pre and post COVID-19, showing how this has changed beyond what can be attributed to a simple reduction of traffic. We finally draw some operational conclusions and discuss the applicability of these findings in a real operational environment.

Description of a migrant pediatric population visiting the Toulouse Children's Hospital emergency department.

BACKGROUND: Today, one in eight migrants and one in two refugees are children. Since this population has been less studied than the adult population, there is little data available on the state of health of this pediatric migrant population and the reasons they seek care. OBJECTIVE: The objective of this study was to describe the sociodemographic and medical characteristics of a pediatric migrant population visiting an emergency department in order to better understand their specific needs. MATERIALS AND METHODS: This was a retrospective observational study using data from medical records and social surveys of migrant children who had visited the Toulouse pediatric emergency department between 1 January 2018 and 31 December 2018. RESULTS: A total of 203 migrant children, i.e., 344 emergency visits, were analyzed. The average age of the children was 3.3 years old. More than half (58.1%) of the children were from Eastern Europe; 71% visited due to infectious pathologies. The severity of the reasons for visiting (90% of the reasons for visiting had a CCMU (Clinical Classification of Emergency Patients) of 1 or 2) and the hospitalization rate (9%) were not higher in the pediatric migrant population than in the general pediatric population. We discovered associated diagnoses (e.g., scabies, anemia, oral and dental disorders) in connection with migration and/or the resulting vulnerability. There was a language barrier in 78% of the visits analyzed with underuse of professional interpreting (7%). CONCLUSION: Because of the journey they make, migrant children are likely to have specific health needs and require dedicated care.

Contrasting chaotic with stochastic dynamics via ordinal transition networks.

We introduce a representation space to contrast chaotic with stochastic dynamics. Following the complex network representation of a time series through ordinal pattern transitions, we propose to assign each system a position in a two-dimensional plane defined by the permutation entropy of the network (global network quantifier) and the minimum value of the permutation entropy of the nodes (local network quantifier). The numerical analysis of representative chaotic maps and stochastic systems shows that the proposed approach is able to distinguish linear from non-linear dynamical systems by different planar locations. Additionally, we show that this characterization is robust when observational noise is considered. Experimental applications allow us to validate the numerical findings and to conclude that this approach is useful in practical contexts.

Discriminating chaotic and stochastic dynamics through the permutation spectrum test.

In this paper, we propose a new heuristic symbolic tool for unveiling chaotic and stochastic dynamics: the permutation spectrum test. Several numerical examples allow us to confirm the usefulness of the introduced methodology. Indeed, we show that it is robust in situations in which other techniques fail (intermittent chaos, hyperchaotic dynamics, stochastic linear and nonlinear correlated dynamics, and deterministic non-chaotic noise-driven dynamics). We illustrate the applicability and reliability of this pragmatic method by examining real complex time series from diverse scientific fields. Taking into account that the proposed test has the advantages of being conceptually simple and computationally fast, we think that it can be of practical utility as an alternative test for determinism.

Distinguishing chaotic and stochastic dynamics from time series by using a multiscale symbolic approach.

In this paper we introduce a multiscale symbolic information-theory approach for discriminating nonlinear deterministic and stochastic dynamics from time series associated with complex systems. More precisely, we show that the multiscale complexity-entropy causality plane is a useful representation space to identify the range of scales at which deterministic or noisy behaviors dominate the system's dynamics. Numerical simulations obtained from the well-known and widely used Mackey-Glass oscillator operating in a high-dimensional chaotic regime were used as test beds. The effect of an increased amount of observational white noise was carefully examined. The results obtained were contrasted with those derived from correlated stochastic processes and continuous stochastic limit cycles. Finally, several experimental and natural time series were analyzed in order to show the applicability of this scale-dependent symbolic approach in practical situations.

Permutation-information-theory approach to unveil delay dynamics from time-series analysis.

In this paper an approach to identify delay phenomena from time series is developed. We show that it is possible to perform a reliable time delay identification by using quantifiers derived from information theory, more precisely, permutation entropy and permutation statistical complexity. These quantifiers show clear extrema when the embedding delay τ of the symbolic reconstruction matches the characteristic time delay τ(S) of the system. Numerical data originating from a time delay system based on the well-known Mackey-Glass equations operating in the chaotic regime were used as test beds. We show that our method is straightforward to apply and robust to additive observational and dynamical noise. Moreover, we find that the identification of the time delay is even more efficient in a noise environment. Our permutation approach is also able to recover the time delay in systems with low feedback rate or high nonlinearity.

Characterization of Gaussian self-similar stochastic processes using wavelet-based informational tools.

Efficient tools to characterize stochastic processes are discussed. Quantifiers originally proposed within the framework of information theory, like entropy and statistical complexity, are translated into wavelet language, which renders the above quantifiers into tools that exhibit the important "localization" advantages provided by wavelet theory. Two important and popular stochastic processes, fractional Brownian motion and fractional Gaussian noise, are studied using these wavelet-based informational tools. Exact analytical expressions are obtained for the wavelet probability distribution. Finally, numerical simulations are used to validate our analytical results.

Extracting features of Gaussian self-similar stochastic processes via the Bandt-Pompe approach.

By recourse to appropriate information theory quantifiers (normalized Shannon entropy and Martín-Plastino-Rosso intensive statistical complexity measure), we revisit the characterization of Gaussian self-similar stochastic processes from a Bandt-Pompe viewpoint. We show that the ensuing approach exhibits considerable advantages with respect to other treatments. In particular, clear quantifiers gaps are found in the transition between the continuous processes and their associated noises.

Phytochemical and antioedematogenic studies of commercial copaiba oils available in Brazil.

The composition of eight samples of commercial copaiba oils, used in the Amazonian region as antiinflammatory agents and available in popular markets, were analysed by gas chromatography/mass spectrometry (HRGC-MS). Major differences were observed in their chemical composition and some adulterations were pointed out. When tested in vivo oils 1 and 3, and to a lesser extent oil 6, significantly inhibited bradykinin-induced oedema formation. The other tested oils had no effect. When assessed in carrageenan-induced oedema formation, oils 1, 2 and 6, but not oil 3, significantly attenuated the oedema formation. The other tested oils failed to affect carrageenan-induced paw oedema. Oils 1 and 6 were further fractionated and several sesquiterpenes and diterpenes were detected. It is suggested that the naturally occurring sesquiterpenes present in the copaiba oils seem to be responsible for the antiinflammatory action reported in the folk medicine. Furthermore, our results clearly show an adulteration in copaiba oils available in Brazil.

Concentration of collagen, aggrecan and cartilage oligomeric matrix protein (COMP) in synovial fluid from equine middle carpal joints.

The aim of the present investigation was to study the metabolic activity of the third carpal bone and the release of COMP, aggrecan and collagen type II molecules in the synovial fluid as a result of injury. Cartilage oligomeric matrix protein (COMP), aggrecan and collagen type II or fragments of these molecules released to the synovial fluid and serum (COMP) were quantified in samples from 73 left equine middle carpal joints from 2 breeds with different activity profiles (52 Standardbred trotters [STB] and 21 Swedish Warmblood riding horses [SWH]) and different articular cartilage lesions. Synovial and serum samples were analysed using inhibition ELISA for COMP and aggrecan. An ELISA that combines features of both the competitive and capture ELISAs was used for collagen type II. COMP and aggrecan concentrations decreased in synovial fluid from the joints with moderate lesions of STB compared with the normal joints; COMP from 16.6 to 12.0 microg/ml and aggrecan from 93.0 to 68.1 microg/ml. In serum, COMP concentrations were also lowered in the STB with moderate lesions compared with the normal joints, while in the SWH, the COMP concentration in synovial fluids from joints with moderate lesions was somewhat increased at 19.6 microg/ml compared with the normal joints (17.6 microg/ml). The ratio between aggrecan/COMP in the synovial fluid from joints with moderate lesions was higher in the STB (6.2) than in the SWH (3.4). The level of collagen type II in synovial fluid was higher in the SWH (8.8 microg/ml) than the STB (1.6 microg/ml), but there was no correlation between joint damage and collagen concentrations in synovial fluids (10.0 and 1.8 microg/ml in joints with moderate lesions from SWH and STB, respectively). A marked difference in COMP synthesised upon metabolic labelling between the normal and osteoarthritic cartilage was seen and the synthesis of COMP in the articular cartilage of the third carpal bone with moderate articular lesions (from an STB) was lower than in the joint with mild lesions. This difference between breeds may reflect different load characters, in release of macromolecules in osteoarthritic and normal joints. This a novel finding that should be considered in studies of equine traumatic arthritis.

Antinociceptive and anti-oedematogenic properties of astilbin, taxifolin and some related compounds.

Astilbin (3-0-alpha-1-rhamnosyl-(2R,3R)-dihydroquercetin), the major constituent isolated from Hymeneae martiana and some derivatives obtained by structural modification, such as taxifolin and two related compounds, were evaluated as analgesics by using both writhing test and formalin test in mice. Their anti-oedematogenic actions were also analysed against paw oedema caused by carrageenan, dextran and bradykinin in rat. The results indicated that some compounds, such as taxifolin (2) and its tetramethylated derivative (4) exhibited potent and dose-dependent antinociceptive action against acetic acid-induced abdominal constriction when administered intraperitoneally or orally. They were more potent than acetylsalicylic acid and paracetamol (acetaminophen), two standard drugs used for comparison. Compounds 2 and 4 were also more potent than these drugs in attenuating to the second phase of the formalin-induced licking. Moreover, both compounds showed significant anti-oedematogenic effect, inhibiting the paw oedema formation induced by dextran. In contrast pentaacetylated taxifolin (3) was capable of inhibiting the paw oedema induced by bradykinin.

State-of-the-art phacoemulsification performed by residents in Buenos Aires, Argentina.

PURPOSE: To analyze the learning curve for state-of-the-art phacoemulsification performed by residents. SETTING: Department of Ophthalmology, Hospital de Clinicas José de San Martin, University of Buenos Aires, Buenos Aires, Argentina. METHODS: The records of patients having phacoemulsification performed by residents from June 1996 to January 1998 were reviewed for preoperative and postoperative best corrected visual acuities and the occurrence of complications. The phacoemulsification technique used for the first 35 surgeries of each resident was compared with that of their last 35 surgeries. RESULTS: The records showed 249 cases of phacoemulsification by residents. Mean preoperative best corrected visual acuity was 0.19 +/- 0.19 (SD). One month postoperatively, it was 0.86 +/- 0.2. Nuclear fracture was performed in a mean of 28.33 +/- 5.0 of the first 35 surgeries by each resident, whereas chopping techniques were used in a mean of 23.33 +/- 1.5 of the last 35 cases. Vitreous loss occurred in 2.8% of cases. CONCLUSION: Residents learned cracking and chopping phacoemulsification techniques safely with satisfactory outcomes.

The distribution of cartilage oligomeric matrix protein (COMP) in tendon and its variation with tendon site, age and load.

A protein prominent in guanidine hydrochloride extracts of adult bovine and equine digital flexor tendons was confirmed to be Cartilage Oligomeric Matrix Protein (COMP) by non-reducing and reducing SDS-PAGE, reaction with rabbit anti-COMP polyclonal antiserum on Western blots, trypsin digestion followed by HPLC on a C2/C18 column, and identification of COMP mRNA from tendon on Northern blots. Immunohistochemistry and Western blots of extracts showed COMP to be present in all regions of digital flexor tendons. Equine tendon COMP was purified by ion exchange chromatography and gel filtration and used in a heterologous inhibition ELISA to quantify COMP in equine digital flexor tendons at different ages, and in other tendons and ligaments. Mean COMP levels in digital flexor tendon were approximately 2-5mg/g wet weight, but they showed a large variation. Levels were low in neonatal tendon but rose rapidly during growth, with the metacarpal (tensional) superficial digital flexor tendon having the highest levels (approximately 10mg/g wet weight). Levels subsequently declined in this region, while in areas which experience a variable amount of compression, levels increased less but then remained constant. Extensor tendons and collateral ligaments, which experience less loading in vivo, had levels similar to those in neonatal tendon. COMP was identified in scarred skin and granulation tissue but not in normal skin, chronic fibrosis, or a fibrosarcomatous skin growth. A unilateral non-weight-bearing growing animal contained three to six times more COMP in the weight-bearing digital flexor tendons compared to the paralyzed limb, while the extensor tendons had similar amounts in both limbs. With the recent discovery of a COMP gene mutation causing pseudoachondroplasia (Hecht et al., 1995), in which lax tendons and ligaments are a feature, the present data suggest that COMP is synthesized in response to, and is necessary for tendon to resist, load.

Increased release of bone sialoprotein into synovial fluid reflects tissue destruction in rheumatoid arthritis.

OBJECTIVE: Bone sialoprotein (BSP) was quantified in synovial fluids and sera from rheumatoid arthritis (RA) patients to elucidate whether its release from bone relates to the degree of joint tissue destruction. Osteocalcin was assayed for comparison. METHODS: BSP and osteocalcin levels were determined by immunoassays of knee synovial fluids and of sera from RA patients who were selected on the basis of radiographic knee joint tissue damage. RESULTS: Synovial fluid concentrations of BSP increased with increasing degrees of knee joint damage (rs = 0.6848, P < 0.001). Synovial fluid concentrations of osteocalcin did not relate to the degree of joint damage. Serum concentrations of BSP were increased, but did not relate to the degree of joint damage. Serum concentrations of osteocalcin were normal, but increased within the range of normal during progression of joint destruction (rs = 0.4567, P < 0.001). CONCLUSION: Quantification of BSP in synovial fluid holds promise as a useful means of assessing the degree of tissue damage at the molecular level in patients with RA.

Characterization of a methanogenic sludge to be used as inoculum for a high-rate reactor.

The sludge of an anaerobic lagoon treating the wastewater from a factory producing baker's yeast was evaluated as inoculum for anaerobic digestion. Specific methanogenic activity tests failed to give a good estimation of the trophic groups that were evidenced by enumerations involving Most Probable Number estimations. This failure was ascribed to the toxic effects of either the acetate concentrations used or to the ammonia content of the sludge.