Critical fluctuations, intermittent dynamics and Tsallis statistics

It is pointed out that the dynamics of the order parameter at a thermal critical point obeys the precepts of the nonextensive Tsallis statistics. We arrive at this conclusion by putting together two well-defined statistical-mechanical developments. The first is that critical fluctuations are correctly described by the dynamics of an intermittent nonlinear map. The second is that intermittency in the neighborhood of a tangent bifurcation in such map rigorously obeys nonextensive statistics. We comment on the implications of this result. Key words: critical fluctuations, intermittency, nonextensive statistics, anomalous stationary statesComment: Contribution to the proceedings of International Workshop on Trends and Perspectives on Extensive and Non-Extensive Statistical Mechanics (q-60), Angra dos Reis, Brazil, 17-21/11/2003. Submitted to Physica

Applied medical informatics for neuroanatomy training

[EN]In recent years, the efforts to apply developments in medical informatics within training contexts have increased. The objective of this paper is to illustrate the benefits associated to the use of three-dimensional visualization digital systems, in a neuroanatomical training context, and evaluate the satisfaction level and perceived usefulness of these tools by students. The three dimensional models generated allowed the anatomical interactive study of brain structures and their spatial relationships in a complete, realistic and visually appealing manner for students, regardless of previous visuo-spatial skills

Watson-Crick hydrogen-bonded macrocycles self-assembled from Z-shaped dinucleoside monomers

The self-assembly of two lipophilic dinucleoside molecules that have a common structure, comprising a bent "Z-shaped"central block substituted at the edges with complementary G and C nucleobases, are studied in this work by a combination of 1D and 2D NMR experiments, as well as by absorption, fluorescence and circular dichroism measurements as a function of the temperature and the concentration. Watson-Crick pairing affords cyclic tetramer G:C H-bound species that are less stable than those formed by related linear dinucleosides and that, in principle, due to the unusual monomer geometry, can establish an equilibrium between different conformations with the shape of a square and a rhom

Assessment of the postmortem nutritional status of children with HIV/AIDS infection

La prevalencia de la infección por el virus de la inmu-nodefi ciencia humana (VIH) se ha incrementado rápidamente en la edad pediátrica. Objetivo: Presentar las manifestaciones nutriciona-les de niños que fallecieron por virus de inmunodefi ciencia humana (VIH)/síndrome de inmunodefi ciencia adquirida (SIDA). Material y métodos: Estudio observacional descriptivo de corte transversal. Se revisaron los protocolos de autopsia e historias clínicas de 26 niños con infección por VIH/SIDA y se analizaron edad, sexo, transmisión, estadio, infecciones, causa de muerte y el estado nutricio (peso (P) y talla (T)): %P/T, %P/E, %T/E. Resultados: Se encontraron 16 casos de estadio B, 7 en C y 3 en A; con edades entre los 2 meses y 15 años; 18 masculinos y 8 femeninos. La vía de transmisión fue: perinatal 46%, transfusión sanguínea (se incluyen casos previos al control de sangre) 27% y transmisión sexual 7.6%. Dieciséis niños presentaron %P/T bajo (5 emaciados); 24% P/E bajo (10 graves), y 24% T/E baja (8 con desmedro). En el intestino se identifi caron: Candida sp., citomegalovirus, Cryptosporidium, sarampión e Histo-plasma capsulatum y extraintestinalmente Pneumocistis carinii, Es-cherichia coli, Pseodomonas aeruginosa y Klebsiella pneumoniae. Al comparar con un grupo de pacientes con leucemia, se observó que el impacto de VIH sobre el estado nutricional es más grave, intenso y prolongado. Conclusión: La alteración nutricia mas frecuente en los niños con VIH/SIDA fue desmedro en el momento de estudio post mortem, seguido de emaciación; la posible causa sería la infección concomitante presente en 85% de los casos.The prevalence of human immunodeficiency virus (HIV) infection has increased rapidly in pediatric age. Objective: To present the nutritional manifestations of children who died from human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Material and methods: Cross-sectional descriptive observational study. The autopsy protocols and medical records of 26 children with HIV/AIDS infection were reviewed and age, sex, transmission, stage, infections, cause of death and nutritional status (weight (P) and height (T)) were analyzed: %P/T, %P/E, %T/E. Results: 16 cases of stage B were found, 7 in C and 3 in A; with ages between 2 months and 15 years; 18 male and 8 female. The transmission route was: perinatal 46%, blood transfusion (cases prior to blood control are included) 27% and sexual transmission 7.6%. Sixteen children had low %P/T (5 emaciated); 24% low P/E (10 serious), and 24% low T/E (8 with impairment). In the intestine, the following were identified: Candida sp., cytomegalovirus, Cryptosporidium, measles and Histoplasma capsulatum and extraintestinally Pneumocystis carinii, Escherichia coli, Pseodomonas aeruginosa and Klebsiella pneumoniae. When compared with a group of patients with leukemia, it was observed that the impact of HIV on nutritional status is more serious, intense and prolonged. Conclusion: The most frequent nutritional alteration in children with HIV/AIDS was wasting at the time of post-mortem study, followed by wasting; The possible cause would be the concomitant infection present in 85% of cases

Bases y caminos algebraicos hacia los OLL/PLL del cubo rubik

El presente libro pretende realizar un compendio de los resultados del análisis matemático de los movimientos y algoritmos, tanto OLL(Orientation of Last Layer: Orientación de la última capa), como PLL(Permutation of Last Layer: Permutación de la última capa), realizados sobre la última capa en el cubo de Rubik 3x3x3, como un verdadero objeto de Enseñanza – Aprendizaje. Es resultado de una investigación aplicada en estudiantes de la Licenciatura de Matemáticas, como alternativa didáctica en asignaturas tales como Teoría de Grupos, Teoría de Números y Matemáticas Recreativas, con una duración aproximada de dos años, en los que se realizó la búsqueda de información, desarrollo intuitivo, formalización, pruebas de campo con los estudiantes, recolección de resultados, entre otros

A Machine-Learning Model for Lung Age Forecasting by Analyzing Exhalations

Spirometers are important devices for following up patients with respiratory diseases. These are mainly located only at hospitals, with all the disadvantages that this can entail. This limits their use and consequently, the supervision of patients. Research efforts focus on providing digital alternatives to spirometers. Although less accurate, the authors claim they are cheaper and usable by many more people worldwide at any given time and place. In order to further popularize the use of spirometers even more, we are interested in also providing user-friendly lung-capacity metrics instead of the traditional-spirometry ones. The main objective, which is also the main contribution of this research, is to obtain a person’s lung age by analyzing the properties of their exhalation by means of a machine-learning method. To perform this study, 188 samples of blowing sounds were used. These were taken from 91 males (48.4%) and 97 females (51.6%) aged between 17 and 67. A total of 42 spirometer and frequency-like features, including gender, were used. Traditional machine-learning algorithms used in voice recognition applied to the most significant features were used. We found that the best classification algorithm was the Quadratic Linear Discriminant algorithm when no distinction was made between gender. By splitting the corpus into age groups of 5 consecutive years, accuracy, sensitivity and specificity of, respectively, 94.69%, 94.45% and 99.45% were found. Features in the audio of users’ expiration that allowed them to be classified by their corresponding lung age group of 5 years were successfully detected. Our methodology can become a reliable tool for use with mobile devices to detect lung abnormalities or diseases.This research was funded by the Spanish Ministerio de Ciencia e Innovación under contract PID2020-113614RB-C22

Feigenbaum graphs at the onset of chaos

We analyze the properties of the self-similar network obtained from the trajectories of unimodal maps at the transition to chaos via the horizontal visibility (HV) algorithm. We first show that this network is uniquely determined by the encoded sequence of positions in the dynamics within the Feigenbaum attractor and it is universal in that it is independent of the shape and nonlinearity of the maps in this class. We then find that the network degrees fluctuate at all scales with an amplitude that increases as the size of the network grows. This suggests the definition of a graph-theoretical Lyapunov exponent that measures the expansion rate of trajectories in network space. On good agreement with the map's counterpart, while at the onset of chaos this exponent vanishes, the subexponential expansion and contraction of network degrees can be fully described via a Tsallis-type scalar deformation of the expansion rate, that yields a discrete spectrum of non-null generalized exponents. We further explore the possibility of defining an entropy growth rate that describes the amount of information created along the trajectories in network space. Making use of the trajectory distributions in the map's accumulation point and the scaling properties of the associated network, we show that such entropic growth rate coincides with the spectrum of graph-theoretical exponents, what appears as a set of Pesin-like identities in the network.Comment: Accepted for publication in Physics Letters

Assessment of a surface-active ionic liquid formulation for EOR applications: Experimental and simulation studies

This study aims to assess a surfactant blend for enhanced oil recovery from carbonate rocks. Due to the abundance of these reservoirs, their profitable exploitation would ensure our petrochemical needs are met, and maintain current quality of life. The objective of this work is to increase the technology readiness level of our previous proposal based on the use of a blend of pure sodium dodecylbenzene sulfonate and the surface-active ionic liquid cocosalkylpentaethoximethyl ammonium methylsulfate. To that aim, the method was adapted for its application with a commercially available petrochemical surfactant (RECOLAS103, a mixture of lineal alkyl benzene sulfonates), and reservoir simulations were carried out to evaluate its effectiveness. Phase behavior, stability, dynamic interfacial tension, adsorption and core flooding were the experimental tests carried out. An optimized formulation consisting of 1 wt% of blend (40 wt% RECOLAS103) in synthetic sea water was found stable and able to reduce water-oil interfacial tension down to 0.02 mN/m. The dynamic blend adsorption in carbonate rocks was found to be 0.60 mg/grock, a promising value for the application. Core flooding tests were conducted at 25 and 120 °C and additional oil recoveries achieved ranged from 10.2 to 12.7% of the original oil in place, the lowest production obtained at the highest temperature. This work offers an advance in the application of surfactants for EOR in carbonate reservoirs, since it improves previous proposals that show stability or high adsorption problems. Moreover, a chemical injection optimization was also carried out by simulation with the CMG-STARS software. Results point to the possibility of reaching higher oil recoveries than those obtained experimentally if the extraction method is optimizedS

Leading Interview and Interrogation Techniques. Focus on Cognitive Interview

Criminal investigation in Mexico is performed by the investigation triad, which is made up of police and experts in diff erent areas such as medicine and prosecutors. They all use interview and interrogation techniques to do their work. Unfortunately, in Mexico, there is no culture of training in governmental institutions responsible for investigating crimes, and results in ignorance of techniques for obtaining objective and reliable information that guarantees the protection of fundamental rights. This chapter illustrates the scope and limits of interview and interrogation techniques and their objectives, with emphasis on the cognitive interview (CI). Th e CI, which has been validated scientifi cally, is one of the best tools to obtain useful information, that is, results of a CI that have been conducted in the field can be used in a court of law. Th is technique can be used with victims, witnesses, or suspects. The current chapter also describes the most utilized techniques, cognitive interview, mnemonic techniques, Strategic Use of Evidence, and Verifi ability Approach

Stacked or folded? impact of chelate cooperativity on the self-assembly pathway to helical nanotubes from dinucleobase monomers

Self-assembled nanotubes exhibit impressive biological functions that have always inspired supramolecular scientists in their efforts to develop strategies to build such structures from small molecules through a bottom-up approach. One of these strategies employs molecules endowed with self-recognizing motifs at the edges, which can undergo either cyclization-stacking or folding-polymerization processes that lead to tubular architectures. Which of these self-assembly pathways is ultimately selected by these molecules is, however, often difficult to predict and even to evaluate experimentally. We show here a unique example of two structurally related molecules substituted with complementary nucleobases at the edges (i.e., G:C and A:U) for which the supramolecular pathway taken is determined by chelate cooperativity, that is, by their propensity to assemble in specific cyclic structures through Watson-Crick pairing. Because of chelate cooperativities that differ in several orders of magnitude, these molecules exhibit distinct supramolecular scenarios prior to their polymerization that generate self-assembled nanotubes with different internal monomer arrangements, either stacked or coiled, which lead at the same time to opposite helicities and chiroptical propertiesFunding from the European Research Council (ERC-Starting Grant 279548 PROGRAM-NANO) MCIN (RED2018- 102331-T, PID2020-116921GB-I00, and TED2021-132602BI00), the Italian Ministry of Education, University and Research (PRIN project prot. 2017A4XRCA_003), the Ministry of Education, Youth, and Sports of the Czech Republic (CZ.02.1.01/0.0/0.0/16_019/0000754, e-INFRA CZ (ID:90254)), the Swedish Research Council (2018- 4343), and the Swedish e-Science Research Centre (SeRC) is gratefully acknowledged. The authors also acknowledge the provision of supercomputer resources from the Swedish National Infrastructure for Computing (SNIC). F.A. is grateful to MCIN and Next Generation EU funding for a “Ramon-yCajal” fellowship (RyC-2021-031538-I). A.dJ. is grateful to EU funding from a MSCA-IEF action (897507-SuprAlloCat