Novel Brain Complexity Measures Based on Information Theory

Brain networks are widely used models to understand the topology and organization of the brain. These networks can be represented by a graph, where nodes correspond to brain regions and edges to structural or functional connections. Several measures have been proposed to describe the topological features of these networks, but unfortunately, it is still unclear which measures give the best representation of the brain. In this paper, we propose a new set of measures based on information theory. Our approach interprets the brain network as a stochastic process where impulses are modeled as a random walk on the graph nodes. This new interpretation provides a solid theoretical framework from which several global and local measures are derived. Global measures provide quantitative values for the whole brain network characterization and include entropy, mutual information, and erasure mutual information. The latter is a new measure based on mutual information and erasure entropy. On the other hand, local measures are based on different decompositions of the global measures and provide different properties of the nodes. Local measures include entropic surprise, mutual surprise, mutual predictability, and erasure surprise. The proposed approach is evaluated using synthetic model networks and structural and functional human networks at different scales. Results demonstrate that the global measures can characterize new properties of the topology of a brain network and, in addition, for a given number of nodes, an optimal number of edges is found for small-world networks. Local measures show different properties of the nodes such as the uncertainty associated to the node, or the uniqueness of the path that the node belongs. Finally, the consistency of the results across healthy subjects demonstrates the robustness of the proposed measures

Dos nuevas especies de Anillini cavernícolas pertenecientes al género Speleotyphlus Jeanne,1973 (Coleoptera, Carabidae)

Speleotyphlus comasi n. sp. and S . virgilii n. sp. from two caves Cueva del Turcacho (Teruel province) and Cova Bonica in Ulldecona (Tarragona province) are described. The former was collected in 1981 and was a female. Despite several attempts the male was not found. Only one other species S. fideli Viñolas & Escolà has been described for the province of Teruel but S. comasi clearly differs regarding the shape of the elytra and umbilicate series. S. virgilii n. sp. is very similar to S. fadriquei Español, 1999 but is slightly larger and the pronotum is transverse rather than elongated as in S. fadriquei Español.Se describen dos nuevas especies Speleotyphlus comasi sp. n. y S . virgilii sp. n. procedentes de dos cuevas: Cueva del Turcacho (provincia de Teruel) y Cova Bonica de Ulldecona (provincia de Tarragona). La primera fue recolectada en 1981 y es una hembra. A pesar de muchos intentos, no se pudo localizar el macho. En la provincia de Teruel sólo se ha descrito otra especie S. fideli Viñolas & Escolà aunque S. comasi difiere claramente de ella en la forma de los elitros y las series umbilicadas. S. virgilii sp. n. es muy simlar a S. fadriquei Español, 1999 pero es ligeramente más larga y el pronoto es transverso más que alargado como en S. fadriquei Español

Caracterización de expresiones artísticas y su utilización como medio catártico y terapéutico

Imágenes, Gráficas.El presente trabajo de investigación tiene como finalidad reconocer el valor del arte como medio de expresión en diferentes procesos humanos, sociales, políticos, económicos y culturales, entre otros a lo largo de la historia, profundizando además en el proceso catártico, comprendido como la descarga de emociones que se conciben desde la fase creativa y su incidencia en la conducta del individuo. Por otra parte, registrar la utilidad de la terapia artística como aporte al fortalecimiento de las relaciones interpersonales, el diálogo, la comunicación, el pensamiento, las ideas, y en general a la transformación de conductas que a su vez están relacionadas con la optimización del bienestar emocional en el ser humano. El objetivo principal, se centra en la caracterización de cuatro expresiones artísticas a saber: música, danza, pintura y teatro, para determinar en cuál de ellas es posible establecer en mayor medida la eficacia del proceso catártico para la generación de bienestar emocional, a partir de la experiencia de doce (12) artistas duitamenses teniendo en cuenta la entrevista como técnica de recolección de información. A partir de los resultados obtenidos a través del análisis de contenidos, establecer criterios de aplicación a la conducción de proceso catártico y bienestar emocional por medio de la terapia artística, con el fin de que pueda ser empleada en diferentes comunidades para reforzar procesos de desarrollo humano y vínculo social. Determinando por medio del análisis de resultados, que la pintura desde su modalidad individual y fase de creación, es la expresión que permite crear un espacio óptimo para el proceso catártico, asumiendo la terapia artística como el medio oportuno para su obtención.The present investigation work has as purpose to recognize the value of the art like half of expression in different human, social, political, economic and cultural processes among others along the history, also deepening in the cathartic process, understood as the discharge of emotions that they are conceived from the creative phase and its incidence in the individual's behavior. On the other hand, to register the utility of the artistic therapy as contribution to the invigoration of the interpersonal relationships, the one dialogues, the communication, the thought, the ideas, and in general to the transformation of behaviors that in turn are related with the optimization of the emotional well-being in the human being. The main objective, is centered that is in the characterization of four artistic expressions: music, dances, painting and theater, to determine in which of them it is possible to settle down in more measure the effectiveness of the cathartic process for the generation of emotional well-being, starting from the experience of twelve (12) artists duitamenses keeping in mind the interview like technique of gathering of information. Starting from the results obtained through the analysis of contents, to establish application approaches to the conduction of cathartic process and emotional well-being by means of the artistic therapy with the purpose of that he/she can be an employee in different communities to reinforce processes of human development and social bond. Determining by means of the analysis of results that the painting from its individual modality and creation phase, is the expression that allows creating a good space for the cathartic process, assuming the artistic therapy as the opportune means for its obtaining

Whole-Body MRI and Ethnic Differences in Adipose Tissue and Skeletal Muscle Distribution in Overweight Black and White Adolescent Boys

It is unclear whether ethnic differences exist in adipose tissue (AT) and skeletal muscle (SM) distribution in black and white youth. Investigation into the pattern of AT and SM distribution in black versus white youth may provide insight into the previously reported health disparities between these ethnicities. Therefore, we examined total and regional AT and SM in overweight black and white boys. The study sample included overweight black (n = 19) and white (n = 21) boys (11–18 yr, BMI ≥ 85th) whose body composition was evaluated using whole-body MRI. Despite similar age, Tanner stage, and BMI, black boys had significantly (P < .05) less visceral AT than white boys and more (P < .05) total and lower-body subcutaneous AT (SAT) in both absolute (kg) and relative (%) terms. There was a main effect (P < .05) of ethnicity on the relationship between total and regional AT, such that for a given amount of total body AT (kg), black boys had a greater (P < .05) lower-body SAT and less visceral AT than their white peers. For a given amount of total SM, black boys had more (P < .05) SM in the thigh. Compared with overweight white boys, overweight black boys have less visceral fat, more subcutaneous fat, and more thigh skeletal muscle

Topological Wilson-loop area law manifested using a superposition of loops

We introduce a new topological effect involving interference of two meson loops, manifesting a path-independent topological area dependence. The effect also draws a connection between quark confinement, Wilson-loops and topological interference effects. Although this is only a gedanken experiment in the context of particle physics, such an experiment may be realized and used as a tool to test confinement effects and phase transitions in quantum simulation of dynamic gauge theories.Comment: Superceding arXiv:1206.2021v1 [quant-ph

Brain parcellation based on information theory

BACKGROUND AND OBJECTIVE: In computational neuroimaging, brain parcellation methods subdivide the brain into individual regions that can be used to build a network to study its structure and function. Using anatomical or functional connectivity, hierarchical clustering methods aim to offer a meaningful parcellation of the brain at each level of granularity. However, some of these methods have been only applied to small regions and strongly depend on the similarity measure used to merge regions. The aim of this work is to present a robust whole-brain hierarchical parcellation that preserves the global structure of the network. METHODS: Brain regions are modeled as a random walk on the connectome. From this model, a Markov process is derived, where the different nodes represent brain regions and in which the structure can be quantified. Functional or anatomical brain regions are clustered by using an agglomerative information bottleneck method that minimizes the overall loss of information of the structure by using mutual information as a similarity measure. RESULTS: The method is tested with synthetic models, structural and functional human connectomes and is compared with the classic k-means. Results show that the parcellated networks preserve the main properties and are consistent across subjects. CONCLUSION: This work provides a new framework to study the human connectome using functional or anatomical connectivity at different levels

Novel Brain Complexity Measures Based on Information Theory

Brain networks are widely used models to understand the topology and organization of the brain. These networks can be represented by a graph, where nodes correspond to brain regions and edges to structural or functional connections. Several measures have been proposed to describe the topological features of these networks, but unfortunately, it is still unclear which measures give the best representation of the brain. In this paper, we propose a new set of measures based on information theory. Our approach interprets the brain network as a stochastic process where impulses are modeled as a random walk on the graph nodes. This new interpretation provides a solid theoretical framework from which several global and local measures are derived. Global measures provide quantitative values for the whole brain network characterization and include entropy, mutual information, and erasure mutual information. The latter is a new measure based on mutual information and erasure entropy. On the other hand, local measures are based on different decompositions of the global measures and provide different properties of the nodes. Local measures include entropic surprise, mutual surprise, mutual predictability, and erasure surprise. The proposed approach is evaluated using synthetic model networks and structural and functional human networks at different scales. Results demonstrate that the global measures can characterize new properties of the topology of a brain network and, in addition, for a given number of nodes, an optimal number of edges is found for small-world networks. Local measures show different properties of the nodes such as the uncertainty associated to the node, or the uniqueness of the path that the node belongs. Finally, the consistency of the results across healthy subjects demonstrates the robustness of the proposed measures

Technical results, clinical efficacy and predictors of outcome of intercostal arteries embolization for hemothorax: A two-institutions’ experience

Background: To evaluate the clinical efficacy and identify the predictors of outcome of intercostal arterial embolization for hemothorax caused by intercostal artery (ICA) injuries. Methods: A retrospective multi-institutional study was conducted. Outcomes were analyzed in 30 consecutive patients presenting with hemothorax caused by active ICA hemorrhage undergoing transcatheter arterial embolization (TAE). Clinical and procedural parameters were compared between outcomes groups. Results: Overall technical success rate was 87% (n=26). Among the 4 failed cases, 2 underwent repeated TAE and 2 underwent additional surgery. Overall 30-day mortality rate was 23%. Low haemoglobin levels and haematocrit, hepatic comorbidities and more than one artery undergoing embolization increased technical failure rate significantly. Survival was poorer in patients with massive bleeding. Conclusions: ICA embolization was found to be a safe and effective method in treating hemothorax caused by active ICA haemorrhage. Careful pre-embolization evaluation may be required for patient with low haemoglobin levels and haematocrit, hepatic comorbidities and active haemorrhage from more than one artery