Relativistic quantum clocks

The conflict between quantum theory and the theory of relativity is exemplified in their treatment of time. We examine the ways in which their conceptions differ, and describe a semiclassical clock model combining elements of both theories. The results obtained with this clock model in flat spacetime are reviewed, and the problem of generalizing the model to curved spacetime is discussed, before briefly describing an experimental setup which could be used to test of the model. Taking an operationalist view, where time is that which is measured by a clock, we discuss the conclusions that can be drawn from these results, and what clues they contain for a full quantum relativistic theory of time.Comment: 12 pages, 4 figures. Invited contribution for the proceedings for "Workshop on Time in Physics" Zurich 201

Functional foods. Reflexions of a scientist regarding a market in expansion

The International Union of Pure and Applied Chemistry (IUPAC) decidió en 2006 impulsar el estudio en América Latina de los nutracéuticos como una oportunidad científica y de interés comercial para toda la comunidad. La inciativa, impulsada por el Subcommittee on Medicinal Chemistry and Drug Development de la IUPAC, presidido por C.R. Ganellin, ha permitido unir esfuerzos de investigadores de América Latina. El proyecto se ha realizado con una presentación general del tema, que se corresponde con este trabajo, al que seguirá inmediatamente una publicación acerca de la situación concreta en diferentes países de la región. El trabajo se presenta de forma simultánea en distintas revistas de manera que se facilite el acceso a él y su siguiente discusión por parte de los interesados, en un intento de crear un clima de interés por el tema sobre la base de la investigación de conocimientos tradicionales y experiencias científicas que permitan la innovación en beneficio de todos, muy especialmente, de las sociedades productoras, así como de las personas que precisen de los compuesto

Functional foods. Reflexions of a scientist regarding a market in expansion

The International Union of Pure and Applied Chemistry (IUPAC) decidió en 2006 impulsar el estudio en América Latina de los nutracéuticos como una oportunidad científica y de interés comercial para toda la comunidad. La inciativa, impulsada por el Subcommittee on Medicinal Chemistry and Drug Development de la IUPAC, presidido por C.R. Ganellin, ha permitido unir esfuerzos de investigadores de América Latina. El proyecto se ha realizado con una presentación general del tema, que se corresponde con este trabajo, al que seguirá inmediatamente una publicación acerca de la situación concreta en diferentes países de la región. El trabajo se presenta de forma simultánea en distintas revistas de manera que se facilite el acceso a él y su siguiente discusión por parte de los interesados, en un intento de crear un clima de interés por el tema sobre la base de la investigación de conocimientos tradicionales y experiencias científicas que permitan la innovación en beneficio de todos, muy especialmente, de las sociedades productoras, así como de las personas que precisen de los compuesto

Constraints on dark matter-nucleon effective couplings in the presence of kinematically distinct halo substructures using the DEAP-3600 detector

DEAP-3600 is a single-phase liquid argon detector aiming to directly detect weakly interacting massive particles (WIMPs), located at SNOLAB (Sudbury, Canada). After analyzing data taken during the first year of operation, a null result was used to place an upper bound on the WIMP-nucleon, spin-independent, isoscalar cross section. This study reinterprets this result within a nonrelativistic effective field theory framework and further examines how various possible substructures in the local dark matter halo may affect these constraints. Such substructures are hinted at by kinematic structures in the local stellar distribution observed by the Gaia satellite and other recent astronomical surveys. These include the Gaia Sausage (or Enceladus), as well as a number of distinct streams identified in recent studies. Limits are presented for the coupling strength of the effective contact interaction operators O1, O3, O5, O8, and O11, considering isoscalar, isovector, and xenonphobic scenarios, as well as the specific operators corresponding to millicharge, magnetic dipole, electric dipole, and anapole interactions. The effects of halo substructures on each of these operators are explored as well, showing that the O5 and O8 operators are particularly sensitive to the velocity distribution, even at dark matter masses above 100 GeV=c

The 'redefinition of death' debate: western concepts and western bioethics.

Biomedicine is a global enterprise constructed upon the belief in the universality of scientific truths. However, despite huge scientific advances over recent decades it has not been able to formulate a specific and universal definition of death: In fact, in its attempt to redefine death, the concept of death appears to have become immersed in ever increasing vagueness and ambiguity. Even more worrisome is that bioethics, in the form of principlism, is also endeavouring to become a global enterprise by claiming neutrality. It appears that the discourse within both disciplines have similarly manipulated the boundaries of death to include the "dying". This paper argues that the redefinition of death debate in biomedicine reveals a concept of personhood which is profoundly western in origin and which is in accordance to the concept adhered to within principlism. Biomedicine and bioethics do not appear to acknowledge the limitations of their own world view and hence lack an understanding of their applicability and appropriateness in diverse social and cultural contexts; a situation which adds credence to claims as to the hegemonic and imperialistic nature of all such global enterprises