Return-Map Cryptanalysis Revisited

As a powerful cryptanalysis tool, the method of return-map attacks can be used to extract secret messages masked by chaos in secure communication schemes. Recently, a simple defensive mechanism was presented to enhance the security of chaotic parameter modulation schemes against return-map attacks. Two techniques are combined in the proposed defensive mechanism: multistep parameter modulation and alternative driving of two different transmitter variables. This paper re-studies the security of this proposed defensive mechanism against return-map attacks, and points out that the security was much over-estimated in the original publication for both ciphertext-only attack and known/chosen-plaintext attacks. It is found that a deterministic relationship exists between the shape of the return map and the modulated parameter, and that such a relationship can be used to dramatically enhance return-map attacks thereby making them quite easy to break the defensive mechanism.Comment: 11 pages, 7 figure

A Comparative Note on Tunneling in AdS and in its Boundary Matrix Dual

For charged black hole, within the grand canonical ensemble, the decay rate from thermal AdS to the black hole at a fixed high temperature increases with the chemical potential. We check that this feature is well captured by a phenomenological matrix model expected to describe its strongly coupled dual. This comparison is made by explicitly constructing the kink and bounce solutions around the de-confinement transition and evaluating the matrix model effective potential on the solutions.Comment: 1+12 pages, 9 figure

Algas de aguas continentales de La Pampa (ARGENTINA) I Vol vocales y Chlorococcales (Chorophyta).

Volvocales and Chlorococcales from Continental waters of La Pampa Province are studied; a11of them are new records for this province. Among the algae observed, six taxa, including varietes and forms are new records for Argentine.Trabajo realizado en el Lab. de Ficología, UBA, con una pasantía de CRUN, 1983. Presentado en 11J. de Geol. l.P. y I J. de Biol. l.P. 1983. Fac. Cs. Exac. Nat. UNLPam.Se estudian Volvocales y Chlorococcales de la provincia de La Pampa, todos los taxones se citan por primera vez para ésta provincia. Siete especies, incluidas. variedades y formas, son citas nuevas para el país.Trabajo realizado en el Lab. de Ficologia, UBA, con una pasantia de CRUN, 1983. Presentado en 11 J. de Geol. l.P. y I J. de Biol. l.P. 1983. Fac. Cs. Exac. Nat. UNLPam

Fracturas de antebrazo: resultado funcional tras reducción abierta y osteosíntesis

Hemos realizado una revisión retrospectiva de pacientes intervenidos por fracturas de antebrazo, recogiendo el resultado funcional (Grace-Eversmann). También hemos analizado la deformidad radial residual mediante el cálculo curvatura mayor del radio (CMR). Se cálculo el coeficiente de correlación de Pearson entre la CMR y el resultado funcional. Los resultados de 20 pacientes intervenidos entre 1972 y 2005. El tratamiento quirúrgico fue de reducción abierta y fijación interna (RAFI) en el 70%. El resultado funcional fue de excelente el 50% y malo en el 20%. La curvatura mayor del radio oscilaba entre 5 mm - 20 mm. No hemos observado correlación entre las variables estudiadas. No hemos observado correlación anatómico-funcional en los pacientes tratados quirúrgicamente por fractura de cubito y radio.Retrospective review of clinical notes. Data regarding to the surgical treatments. Functional outcomes (Grace-Eversmann). Residual radius deformity was analyzed measuring the radius curvature. Pearson's correlation coefficient was measured between radius curvature and functional outcome. Data of 20 patients attended between 1972 and 2005 are reviewed. Surgical treatment was open reduction and internal fíxation in 70% patients. The outcome was excellent in 50 % and poor in 20%. La major curve of the radius was between 5mm -20 mm. We haven't seen correlation in the variables studied. We haven't seen between the curvature of the radius and functional outcome any correlation in patients treated surgically of ulna and radius fractures

Effect of pressure-induced changes in the ionization equilibria of buffers on inactivation of Escherichia coli and staphylococcus aureus by high hydrostatic pressure

Survival rates of Escherichia coli and Staphylococcus aureus after high-pressure treatment in buffers that had large or small reaction volumes (¿V°), and which therefore underwent large or small changes in pH under pressure, were compared. At a low buffer concentration of 0.005 M, survival was, as expected, better in MOPS (morpholinepropanesulfonic acid), HEPES, and Tris, whose ¿V° values are approximately 5.0 to 7.0 cm3 mol-1, than in phosphate or dimethyl glutarate (DMG), whose ¿V° values are about -25 cm3 mol-1. However, at a concentration of 0.1 M, survival was unexpectedly better in phosphate and DMG than in MOPS, HEPES, or Tris. This was because the baroprotective effect of phosphate and DMG increased much more rapidly with increasing concentration than it did with MOPS, HEPES, or Tris. Further comparisons of survival in solutions of salts expected to cause large electrostriction effects (Na2SO4 and CaCl2) and those causing lower electrostriction (NaCl and KCl) were made. The salts with divalent ions were protective at much lower concentrations than salts with monovalent ions. Buffers and salts both protected against transient membrane disruption in E. coli, but the molar concentrations necessary for membrane protection were much lower for phosphate and Na2SO4 than for HEPES and NaCl. Possible protective mechanisms discussed include effects of electrolytes on water compressibility and kosmotropic and specific ion effects. The results of this systematic study will be of considerable practical significance in studies of pressure inactivation of microbes under defined conditions but also raise important fundamental questions regarding the mechanisms of baroprotection by ionic solutes

Especies de caza: procesos de extinción ocultos tras elevados tamaños de censo

Management of game species may involve a risk of alteration of their genetic properties. Local adaptations may be disrupted if artificially selected individuals from farms or those belonging to distant geographical areas are introduced to increase population density or trophy “quality”. In Spain, red deer (Cervus elaphus) from different European subspecies have been introduced to increase the size of trophies (antlers) of local populations. Legislation against these introductions is not effective for various reasons, and once the individuals are in the Iberian peninsula it is virtually impossible to prevent their spreading throughout the whole territory without a genetic tool to distinguish between autochthonous and foreign specimens. We have developed such a genetic test and propose a strategy to dissuade land–owners from importing foreign deer. Since deer are bred mainly for their antlers, our strategy is based on an agreement with the National Trophy Body in Spain which rejects trophies from foreign populations. Rejection decreases the value of the trophy so that it becomes more profitable to produce autochthonous deer. Using such a strategy at some critical step in the production or commercialization process may be a good model to apply in protecting genetic properties of exploited species.La gestión de las especies de caza puede conllevar riesgos de alteración de sus propiedades genéticas. Las adaptaciones locales pueden deteriorarse si ejemplares producidos mediante selección artificial en granjas o procedentes de áreas geográficas distantes, son introducidos para aumentar la densidad poblacional o la "calidad" de los trofeos de caza. En España, se han introducido ejemplares de ciervo ibérico (Cervus elaphus) procedentes de distintas subespecies europeas para aumentar así el tamaño de las cuernas (trofeos de caza) de las poblaciones autóctonas. La legislación contra este tipo de introducciones no es eficaz por diversos motivos y, una vez introducidos los ejemplares en la península ibérica, es prácticamente imposible prevenir su dispersión por todo el territorio sin contar con herramientas genéticas que permitan diferenciar los ejemplares autóctonos de los foráneos. Nosotros hemos desarrollado un test genético para este fin, y hemos propuesto una estrategia para disuadir a lospropietarios de llevar a cabo la importación de ejemplares foráneos. Puesto que los ciervos se crían fundamentalmente por su cornamenta como trofeo de caza, nuestra estrategia se ha basado en un acuerdo con la Junta Nacional de Homologación de Trofeos de Caza, para que ésta rechace los trofeos pertenecientes a ejemplares foráneos. Este rechazo reduce el valor de los ejemplares procedentes de otras poblaciones y favorece la producción de ciervo autóctono. Sugerimos que la utilización de estrategias de este tipo en puntos clave de procesos de producción o comercialización, puede ser un buen modelo a aplicar para proteger las propiedades genéticas de las especies sujetas a explotación por el hombre

Game species: extinction hidden by census numbers

Management of game species may involve a risk of alteration of their genetic properties. Local adaptations may be disrupted if artificially selected individuals from farms or those belonging to distant geographical areas are introduced to increase population density or trophy ‘quality’. In Spain, red deer (Cervus elaphus) from different European subspecies have been introduced to increase the size of trophies (antlers) of local populations. Legislation against these introductions is not effective for various reasons, and once the individuals are in the Iberian peninsula it is virtually impossible to prevent their spreading throughout the whole territory without a genetic tool to distinguish between autochthonous and foreign specimens. We have developed such a genetic test and propose a strategy to dissuade land-owners from importing foreign deer. Since deer are bred mainly for their antlers, our strategy is based on an agreement with the National Trophy Body in Spain which rejects trophies from foreign populations. Rejection decreases the value of the trophy so that it becomes more profitable to produce autochthonous deer. Using such a strategy at some critical step in the production or commercialisation process may be a good model to apply in protecting genetic properties of exploited species

Use of Multiple Astrocytic Configurations within an Artificial Neuro-Astrocytic Network

[Abstract] The artificial neural networks used in a multitude of fields are achieving good results. However, these systems are inspired in the vision of classical neuroscience where neurons are the only elements that process information in the brain. Advances in neuroscience have shown that there is a type of glial cell called astrocytes that collaborate with neurons to process information. In this work, a connectionist system formed by neurons and artificial astrocytes is presented. The astrocytes can have different configurations to achieve a biologically more realistic behaviour. This work indicates that the use of different artificial astrocytes behaviours is beneficial.Xunta de Galicia; ED431G/01Xunta de Galicia; ED431D 2017/16Xunta de Galicia; ED431D 2017/23Ministerio de Economía y Competitividad; UNLC08-1E-002Ministerio de Economía y Competitividad; UNLC13-13-350