Prop de tres-cents cinquanta anys d'història natural dels protozous

Quan pensem en microorganismes, ens acostumen a venir al cap els bacteris, i potser els fongs. Però hi ha un grup d'eucariotes unicel·lulars heteròtrofs que tenen una llarga trajectòria en la història de la biologia i que tot sovint passen desapercebuts. Són els protozous, un grup que inclou des de paràsits que afecten els humans i el bestiar, fins a organismes que són actors principals de les xarxes tròfiques marines. Tot sovint oblidem que van ser els primers microbis observats pels humans i que ja fa prop de tres-cents cinquanta anys que són objecte d'estudi pels biòlegs

Work Statistics, Loschmidt Echo and Information Scrambling in Chaotic Quantum Systems

Characterizing the work statistics of driven complex quantum systems is generally challenging because of the exponential growth with the system size of the number of transitions involved between different energy levels. We consider the quantum work distribution associated with the driving of chaotic quantum systems described by random matrix Hamiltonians and characterize exactly the work statistics associated with a sudden quench for arbitrary temperature and system size. Knowledge of the work statistics yields the Loschmidt echo dynamics of an entangled state between two copies of the system of interest, the thermofield double state. This echo dynamics is dictated by the spectral form factor. We discuss its relation to frame potentials and its use to assess information scrambling.Comment: 11+6pp, 5 figures. v3: version accepted for publication in Quantu

Sensor electroquímic de clor per a aigües potables

El lleixiu, amb el clor que conté, és necessari per a desinfectar l'aigua que prenem, però en dosis elevades podria intoxicar-nos. Per això, és important que les eines que detecten la quantitat de clor en l'aigua siguin fiables. Investigadors del Centre Nacional de Microelectrónica han creat un xip que permet verificar amb exactitud i de manera continuada la quantitat de clor en l'aigua

On the orteguian condemnation of literature: Presicion and speech “in partibus infidelium”

Este trabajo pretende esclarecer la ambigua posición que ocupa la perspectiva literaria en la obra de José Ortega y Gasset, manifiesta en la tensión que se da entre la condena explícita que hace de la literatura en algunos de sus textos y el carácter literario que posee su propia escritura. Se trata, a la postre, de sugerir una lectura alejada de las líneas interpretativas que han definido tradicionalmente los análisis de esta cuestión, incidiendo en la importancia que los elementos literarios juegan en el entramado de la filosofía de Ortega incluso a pesar de esos juicios condenatoriosThis paper aims to clarify the ambiguous role of the literary perspective in the work of José Ortega y Gasset, manifested in the tension between the explicit condemnation he makes of literature in some of his texts and the literary character of his own writing. In the end, the objective is to suggest a reading away from the interpretive lines that have traditionally defined the analyzes of this issue, emphasizing the importance that the literary elements play in the framework of the philosophy of Ortega even in spite of those condemnatory judgementsTrabajo cofinanciado por la Agencia Canaria de Investigación, Innovación y Sociedad de la Información de la Consejería de Economía, Industria, Comercio y Conocimiento y por el Fondo Social Europeo (FSE) Programa Operativo Integrado de Canarias 2014-2020, Eje 3 Tema Prioritario 74 (85%

Some notes about Arabic writing and Muslim documents of the moriscos of La Mancha before and after the expulsion

El uso del árabe (escrito o hablado) estuvo bastante extendido entre los moriscos de algunas regiones peninsulares, especialmente en los reinos de Valencia y Granada. Sin embargo, en Castilla, esa situación es más difícil de percibir, al menos hasta que se produce la llegada de los granadinos en 1571. El objetivo del presente trabajo es poner de manifiesto que los moriscos castellanos también hicieron uso de dicho idioma y leyeron y poseyeron libros, documentos y escritos prohibidos. Como resultado de dicha constatación, se pretende también observar cómo dicho uso tuvo una doble dimensión: primero, como vehículo de expresión religiosa; segundo, y sobre todo, como elemento de identificación y cohesión cultural.The use of the Arabic (written or spoken) was considerably extended to the Moriscos of some regions of the Iberian Peninsula, specially in the kingdoms of Valencia and Granada. Nevertheless, in Castile, this situation is hardly noticed, at least until the arrival of the Moriscos of the Kingdom of Granada in 1571. The aim of this paper is to highlight that the Moriscos of Castile also used the Arabic language and that they both read and owned forbidden books and documents. As a result of the above mentioned verification, we also observe how that already mentioned application had a double dimension: on the one hand, as a vehicle of religious expression; and, specially, on the other hand, as an element of cultural identification

Quantum work statistics, Loschmidt echo and information scrambling

A universal relation is established between the quantum work probability distribution of an isolated driven quantum system and the Loschmidt echo dynamics of a two-mode squeezed state. When the initial density matrix is canonical, the Loschmidt echo of the purified double thermofield state provides a direct measure of information scrambling and can be related to the analytic continuation of the partition function. Information scrambling is then described by the quantum work statistics associated with the time-reversal operation on a single copy, associated with the sudden negation of the system Hamiltonian.Comment: 6 pages, 1 figure, published versio

Market risk premium used in 2010 by analysts and companies: A survey with 2.400 answers

The average MRP used by analysts in the United States and Canada (5.1%) was similar to the one used by their colleagues in Europe (5.0%), and United Kingdom (5.2%). But the average MRP used by companies in the United States and Canada (5.3%) was smaller than the one used by companies in Europe (5.7%), and United Kingdom (5.6%). The dispersion of the MRP used was high, but lower than that of the MRP used by professors: the average range of MRP used by analysts (companies) for the same country was 5.7% (4.1%) and the average standard deviation was 1.7% (1.2%). These statistics were 7.4% and 2.4% for the professors. Most previous surveys have been interested in the Expected MRP, but this survey asks about the Required MRP. The paper also contains the references that analysts and companies use to justify their MRP, and comments from 89 respondents that illustrate the various interpretations of what is the required MRP.market risk premium; required equity premium; expected equity premium; historical equity premium;

Market risk premium used in 2010 by professors: A survey with 1,500 answers

The average Market Risk Premium (MRP) used in 2010 by professors in the United States (6.0%) was higher than the one used by their colleagues in Europe (5.3%). We also report statistics for 33 countries: the average MRP used in 2010 ranges from 3.6% (Denmark) to 10.9% (Mexico). 29% of the professors decreased the MRP in 2010, 16% increased it and 55% used the same MRP. The dispersion of the MRP used was high: the average range of MRP used by professors for the same country was 7.4% and the average standard deviation was 2.4%. Most previous surveys have been interested in the Expected MRP, but this survey asks about the Required MRP. The paper also contains the references that professors use to justify their MRP, and comments from 85 professors that illustrate the various interpretations of what is the required MRP.equity premium puzzle; required equity premium; expected equity premium; historical equity premium;