Resource allocation of the human brain : a competitive equilibrium approach

A novel model to study the resource allocation of a functioning brain is proposed. The mechanism is based on the theory of competitive equilibrium (CE), where users (cortical areas of the brain) are competing for a finite resource such as oxygenated blood. Concepts of CE are mathematically adjusted to be used with functional magnetic resonance imaging (FMRI) data. The current study uses imaging data were subjects are requested to selectively attend and respond to either a visual or auditory metronome in the presence of asynchronous cross-modal distractors. Two studies with distinct patient populations (patients with schizophrenia patients with mild traumatic brain injuries) are used to asses the applicability of the proposed method. Comparisons to traditionally used methods to analyze simulated and real FMRI data are also provided. Results indicate that it is possible to mathematically formulate an underlying resource allocation mechanism of a human brain. Additionally, when comparing to traditional analysis methods, the proposed model increases the sensitivity of these data when examining different stimuli conditions and also increases the classification accuracy between the patient group versus normal controls

On the origin of the extra capacity at low potential in materials for Li batteries reacting through conversion reaction

The possibility of interfacial storage at low potential for electrode materials reacting through conversion reactions was evaluated. The amount of charge that could be stored through the proposed interfacial mechanism was estimated for a range of different materials and found to be much lower than those observed experimentally. Moreover, the slope of the potential decay and the influence of the current in the extent of stored capacity for experiments carried out in composite electrodes containing Co3O4 are not consistent with a capacitive-like mechanism. In summary, no evidence for capacitive storage could be found, our results being in agreement with the process taking place at low potential being solely related to electrolyte decomposition

Development of an opposed piston geared hypocycloid engine

The conventional slider crank engine has dominated the industry with very few alternative configurations having commercial success. In aircraft applications where engine balancing is critical to reduce vibrations, boxer engines have been developed to reduce this issue. The rising cost of fuel and awareness of pollutant emissions has led to an increased interest in alternative designs where both opposed piston and geared hypocycloid engines present some advantages over the conventional slider crank engine. In this study, a comparison between an opposed piston slider crank and geared hypocycloid engine was made followed by the design of a proposed opposed piston geared hypocycloid engine to be used in aircraft applications. It was found that the performance of the geared hypocycloid engine was similar to that of the slider crank engine in all performance characteristics considered in this study, even when excluding the mechanical losses due to friction of the piston head against the cylinder. Therefore, when considering the potential reduced losses due to friction, the geared hypocycloid engine should achieve higher efficiency. It was also found that the design of an engine is a complex task that is usually done from experience and empirical relations with a lot of practical work needing to be done to better design and describe an engine’s performance. However, this study did not include any practical testing.O motor convencional biela-manivela domina a indústria com escassas alternativas a conseguirem terem sucesso comercial. Em aplicações aeronáuticas onde o balanceamento do motor é crítico para reduzir as vibrações induzidas, motores com a configuração ‘boxer’ foram desenvolvidos para minimizar este problema. O crescente custo de combustível e preocupação com as emissões de gases poluentes levou a um aumento no interesse por motores alternativos onde os ambos os motores de pistões opostos e engrenagem hipocicloidal apresentam algumas vantagens sobre os motores de biela-manivela convencionais. Neste estudo é feita uma comparação entre dois motores de pistões opostos, o primeiro com um conjunto biela-manivela e o segundo com engrenagem hipocicloidal, seguido de uma proposta de desenho de um motor de pistões opostos hipocicloidal para ser usado em aplicações aeronáuticas. Verificou-se que o desempenho do motor com engrenagem hipocicloidal foi semelhante ao do motor com biela-manivela em todas as características de desempenho consideradas neste estudo, mesmo excluindo as perdas mecânicas por fricção entre o pistão e o cilindro. Assim, se considerarmos a potencial redução nas perdas por fricção, o motor com engrenagem hipocicloidal deverá alcançar uma eficiência superior. Verificou-se também que o desenvolvimento de um motor é uma tarefa complexa que normalmente é feita com base na experiência e relações empíricas sendo necessário muito trabalho experimental para melhor desenvolver e caracterizar o desempenho do motor. Apesar disso, neste estudo não foi feito qualquer trabalho experimental

El cabildo catedralicio de Lima contra el párroco Alonso de Huerta por las rentas eclesiásticas (1592-1606)

El objetivo de este trabajo es reconstruir las tensiones políticas entre una oligarquía eclesiástica local, centrada en el Cabildo metropolitano, y el segundo arzobispo de Lima, Toribio Alfonso de Mogrovejo (1538-1606), y el párroco Alonso de Huerta, uno de sus más fieles colaboradores. Aunque el Cabildo era una especie de senado o consejo permanente al servicio del clero diocesano, en ningún momento actuó como una institución de apoyo a la labor evangélica del Arzobispo Mogrovejo. Muy al contrario, sus miembros cerraron filas contra lo que consideraron una violación de sus privilegios económicos, y en numerosas ocasiones denunciaron al Arzobispo y al párroco Alonso de Huerta por considerar que se entrometían en el fuero interno del Cabildo.The aim of this contribution is the presentation of the political conflicts between the Archbishop of Lima, Toribio Alfonso de Mogrovejo (1538-1606), together with his faithful collaborator the parish priest Alonso de Huerta, and the cathedral chapter. Though the chapter was a sort of senate or permanent council of the diocese clergy, it by no means acted as an institution involved in the missionary commitments of Archbishop Mogrovejo. On the contrary, its members rallied around against what they considered to be a violation of their economic privileges, and on several instances they denounced the Archbishop, as well as the parish priest Alonso de Huerta, arguing that they intruded in the internal rules of the chapter.Publicad

ESCRITURAS SILENCIADAS EN LA ÉPOCA DE CERVANTES

Escrituras silenciadas en la época de Cervantes, de Manuiel Casado Arboniés, Antonio Castillo Gómez, Paulina Numhauser, Emilio Sola Castaño (eds.), Alcalá de Henares: UAM, 2006, 546 pp

IDENTIDADES AMBIVALENTES. SEFARDÍES EN LA ESPAÑA CONTEMPORÁNEA

Maite Ojeda Mata, Identidades ambivalentes. Sefardíes en la España contemporánea, Sefarad Editores, Madrid, 2012

Los jesuitas y las misiones de frontera del alto Perú: Santa Cruz de la Sierra (1587-1603)

Many historians have stressed the marginality of Santa Cruz de la Sierra, its isolation and the bellicosity of the native population as a way to understand the character no less aggressive of the Spanish colonizers. Whereas the Indian Chiriguanes acquired hostile connotations (“warlike Indians” or “slave hunters”), the Spaniards were elevated to the category of military heroes who struggled in a frontier society. To challenge these considerations, which prioritize individual enterprises, based on the private initiative of caudillos such as Domingo de Irala, Andrés Manso, Ñuflo de Chaves or Lorenzo Suarez de Figueroa in search for the gold of Paititi or that of the Mojos, I want to put a great deal of emphasis on the formation of power groups in the cruceña society at the turn of the 17th century. The projects of conquest and colonization of such “military heroes” were the result of a network of social and religious alliances to gain political hegemony. The arrival of the Jesuits as “religious heroes” was a valuable support to wage a great number of military campaigns against the chiriguanes between 1587 and 1603 in those frontier spaces in Upper Peru

Criollismo, redes clientelares y la Compañía de Jesús: la familia Garavito-Illescas en el Perú virreinal (siglo XVII)

El objetivo de este ensayo es subrayar las relaciones clientelares establecidas entre la influyente familia de los León Garavito (o Garavito de León) y la Compañía de Jesús en el Perú virreinal, poniendo especial énfasis en sus conexiones con el criollismo de finales del siglo XVIIPeer reviewe