Eigencentrality based on dissimilarity measures reveals central nodes in complex networks.

One of the most important problems in complex network's theory is the location of the entities that are essential or have a main role within the network. For this purpose, the use of dissimilarity measures (specific to theory of classification and data mining) to enrich the centrality measures in complex networks is proposed. The centrality method used is the eigencentrality which is based on the heuristic that the centrality of a node depends on how central are the nodes in the immediate neighbourhood (like rich get richer phenomenon). This can be described by an eigenvalues problem, however the information of the neighbourhood and the connections between neighbours is not taken in account, neglecting their relevance when is one evaluates the centrality/importance/influence of a node. The contribution calculated by the dissimilarity measure is parameter independent, making the proposed method is also parameter independent. Finally, we perform a comparative study of our method versus other methods reported in the literature, obtaining more accurate and less expensive computational results in most cases.

Comment on "Similarity between quantum mechanics and thermodynamics: Entropy, temperature, and Carnot cycle".

In the paper by Abe and Okuyama [Phys. Rev. E 83, 021121 (2011)], the quantum Carnot cycle of a simple two-state model of a particle confined in a one-dimensional infinite potential well is discussed. It is claimed that the state at the beginning of the quantum Carnot cycle is pure. After that, it is apparently transmuted to a mixed state if Clausius equality is imposed. We prove that this statement is incorrect. In particular, we prove that the state at the beginning of the cycle is mixed due to the process of measuring energy.

Neurolinfomatosis como manifestación inicial de recidiva en linfoma / Neurolymphomatosis as initial manifestation of recurrence in lymphoma

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Winnerless competition in coupled Lotka-Volterra maps.

Winnerless competition is analyzed in coupled maps with discrete temporal evolution of the Lotka-Volterra type of arbitrary dimension. Necessary and sufficient conditions for the appearance of structurally stable heteroclinic cycles as a function of the model parameters are deduced. It is shown that under such conditions winnerless competition dynamics is fully exhibited. Based on these conditions different cases characterizing low, intermediate, and high dimensions are therefore computationally recreated. An analytical expression for the residence times valid in the N-dimensional case is deduced and successfully compared with the simulations.

Retinopatía del prematuro / Retinopathy of Prematurity

La retinopatía del prematuro (RDP) es una complicación frecuente en los egresados de las UCIN y una causa importante de ceguera. Su prevención primaria depende de una tención reacional que respete límites de saturación en la oxigenoterapia. Su prevención secundaria requiere controles oftalmológicos oportunos y reiterados hasta completarse la vascularización de la retina. Estudios epidemiológcios realizados en el 2002 encontraron una situación alarmante por la frecuente afectación de pacientes de bajo riesgo (PN > 1500 g) y controles oftalmológicos tardíos. A partir del 2003 se conformó un grupo colaborativo multicéntrico para revertir esta situación. Objetivo: analizar las modificaciones de las características de los RN derivados por RDP al hospital JP Garrahan durante los períodos 1996-1999, 2000-2003 y 2004-2007. Métodos: diseño retrospectivo. Las variables analizadas fueron: PN, edad gestacional (EG), tiempo de tratamiento con 02 y ARM, edad de consulta, severidad de RDP, lugar dederivación (> o < a 70 Km). Resultados: el nº de consultas fue de 190, 613 y 489 respectivamente. La proporción de pacientes derivados de > 70 Km disminuyó del 50 al 35 por ciento. Los pacientes del último período han tenido > tiempo de ARM (P 0.04) y oxigenoterapia (p 0.001) pero no varió significativamente su PN ni EG. La proporción de pacientes con RDP severa aumentó del 56 por ciento al 67 por ciento. conclusión: ha disminuido la frecuentcia de derivaciones y las mismas coresponden a pacientes más graves. Continúa siendo la inaceptable la proporción de pacientes de bajo riesgo y la severidad de la RDP al momento de consulta.