Cryptanalysis of a family of self-synchronizing chaotic stream ciphers

Unimodal maps have been broadly used as a base of new encryption strategies. Recently, a stream cipher has been proposed in the literature, whose keystream is basically a symbolic sequence of the (one-parameter) logistic map or of the tent map. In the present work a thorough analysis of the keystream is made which reveals the existence of some serious security problemsComment: 10 pages, 6 figure

Electromagnetic radiation produced by avalanches in the magnetization reversal of Mn12-Acetate

Electromagnetic radiation produced by avalanches in the magnetization reversal of Mn12-Acetate has been measured. Short bursts of radiation have been detected, with intensity significantly exceeding the intensity of the black-body radiation from the sample. The model based upon superradiance from inversely populated spin levels has been suggested

Ventilatory function in young adults and dietary antioxidant intake

Artículo de publicación ISIDietary antioxidants may protect against poor ventilatory function. We assessed the relation between ventilatory function and antioxidant components of diet in young Chileans. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and the ratio FEV1/FVC were measured in 1232 adults aged 22-28 years, using a Vitalograph device. Dietary intake was ascertained with a food frequency questionnaire (FFQ) designed for this study, from which nutrient and flavonoid intakes were estimated. Dietary patterns were derived with Principal Component Analysis (PCA). After controlling for potential confounders, dietary intake of total catechins was positively associated with FVC (Regression coefficient (RC) of highest vs. lowest quintile of intake 0.07; 95% CI 0.01 to 0.15; p per trend 0.006). Total fruit intake was related to FVC (RC of highest vs. lowest quintile 0.08; 95% CI 0.003 to 0.15; p per trend 0.02). Intake of omega 3 fatty acids was associated with a higher FEV1 (RC for highest vs. lowest quintile 0.08; 95% CI 0.01 to 0.15 L; p per trend 0.02) and with FVC 0.08 (RC in highest vs. lowest quintile of intake 0.08, 95% CI 0.001 to 0.16; p per trend 0.04). Our results show that fresh fruits, flavonoids, and omega 3 fatty acids may contribute to maintain ventilatory function.Wellcome Trust 059448Z

Mismatches between childhood television audience and protection schedules

La ley audiovisual reconoce que el público infantil necesita una atención especial por parte de las televisiones y reserva unos horarios de protección reforzada en los que se deben vigilar los contenidos. Este artículo analiza si hay correlación entre esos horarios y el consumo real que hacen los espectadores de 4 a 12 años. A través de los datos de audiencia facilitados por Kantar Media se investiga de forma exhaustiva y comparada en qué momentos hay más niños viendo la televisión, qué cadenas ven y cuáles son sus contenidos preferidos. Se concluye que la segunda hora del día con mayor presencia de niños frente al televisor (de 22:00 a 23:00) se encuentra fuera del horario protegido. Los canales más vistos por el público infantil son Clan, Boing y Disney, con datos muy superiores a los demás. Pero los niños, escogen su propio menú audiovisual: se concentran en los canales específicos en las franjas protegidas y buscan otro tipo de contenidos en los momentos de mayor consumo. También destaca que los niños acompañados por adultos consumen más los canales generalistas que aquellos que lo hacen sin presencia de mayores.Spanish audiovisual law recognizes that children need a special care from broadcasters and to keep a strengthened schedule in. This article analyses if there is correlation between the real consumption that make viewers from 4 to 12 years and the time-slots that are proposed in the Bill. Through some audience data provided by Kantar media, it is investigated in an exhaustive and a compared way which are the hours with most children watching television, and which channels and contents are their favorites. It is concluded that the second hour with more kids in front of TV (from 22:00 to 23:00) is out of the strengthened schedule. The children´s favorite channels are Clan, Boing and Disney, with higher ratings than other. But children build their own audiovisual menu: they choose kids channels in strengthened schedule, but they look for other contents in prime time. Also is remarkable, that kids accompanied by adults consume more the general channels than the ones who do it without adults

Contribución historiográfica a la visita del Papa a Sevilla

Discurso de ingreso para tomar posesión de una plaza de Numerario, leido el 19 de febrero de 1984

Temperatura del sol : conferencia de extensión universitaria, Valladolid, 10 abril 1920

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201