4,965 research outputs found

    On the Stability of Fundamental Couplings in the Galaxy

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    Astrophysical tests of the stability of Nature's fundamental couplings are a key probe of the standard paradigms in fundamental physics and cosmology. In this report we discuss updated constraints on the stability of the fine-structure constant α\alpha and the proton-to-electron mass ratio μ=mp/me\mu=m_p/m_e within the Galaxy. We revisit and improve upon the analysis by Truppe {\it et al.} by allowing for the possibility of simultaneous variations of both couplings and also by combining them with the recent measurements by Levshakov {\it et al.} By considering representative unification scenarios we find no evidence for variations of α\alpha at the 0.4 ppm level, and of μ\mu at the 0.6 ppm level; if one uses the Levshakov bound on μ\mu as a prior, theα\alpha bound is improved to 0.1 ppm. We also highlight how these measurements can constrain (and discriminate among) several fundamental physics paradigms.Comment: 7 pages, 1 figur

    Solving 1ODEs with functions

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    Here we present a new approach to deal with first order ordinary differential equations (1ODEs), presenting functions. This method is an alternative to the one we have presented in [1]. In [2], we have establish the theoretical background to deal, in the extended Prelle-Singer approach context, with systems of 1ODEs. In this present paper, we will apply these results in order to produce a method that is more efficient in a great number of cases. Directly, the solving of 1ODEs is applicable to any problem presenting parameters to which the rate of change is related to the parameter itself. Apart from that, the solving of 1ODEs can be a part of larger mathematical processes vital to dealing with many problems.Comment: 31 page

    Degradation of sugar colourants by the white rot fungus Phanerochaete chrysosporium

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    Colour in sugar industry consists in a complex mixture of different types of colouranfs . The most important being: (1) phenolic compounds coming from the cane plant, (2) caramels which are produced by thermal degradation and condensation reactions of sugars and (3) melanoidins formed from sugar-amino acid reactions via the Maillard reaction. During refining process colourants are removed, at least in part, from the "Iugar liquor by anion-exchange resins. The regeneration of the resins produces an effluent containing those colourants. In order to study the ability of P. chrysosporium to degrade each family of colourant, different culture media specifically enriched with each colourant type were assayed. The results showed that the organism was able to degrade all kinds of tested colourants

    Anisakis infection in allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), from Western Iberian Peninsula Rivers : zoonotic and ecological implications

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    Acknowledgments The authors would like to thank M. N. Cueto and J.M. Antonio (ECOBIOMAR) for their excellent technical support and also Rodrigo López for making the map of the study area. We also thank the personal of the Vigo IEO, for providing information about shad captures at sea collected on the basis of national program (AMDES) included in the European Data Collection Framework (DCF) project. We are also grateful to Comandancia Naval de Tui for providing fishing data. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068). This study was partially supported by a PhD grant from the Portuguese Foundation for Science and Technology (FCT) SFRH/BD/44892/2008) and partially supported by the European Regional Development Fund (ERDF) through the COMPETE—Operational Competitiveness Programme and national funds through Foundation for Science and Technology (FCT), under the project BPEst-C/MAR/ LA0015/2013. The authors thank the staff of the Station of Hydrobiology of the USC BEncoro do Con^ due their participation in the surveys. This work has been partially supported by the project 10PXIB2111059PR of the Xunta de Galicia and the project MIGRANET of the Interreg IV BSUDOE (South-West Europe) Territorial Cooperation Programme (SOE2/P2/E288). D.J. Nachón is supported by a PhD grant from the Xunta de Galicia (PRE/2011/198)Peer reviewedPostprin

    Primary vulvar Paget disease - the importance of clinical suspicion

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    Extramammary Paget disease of the vulva is a rare condition that accounts for only 1-2% of vulvar malignancies and represents a frequent cause of misdiagnosis. It is most commonly seen in postmenopausal women. Clinically it is similar to Paget disease of the breast, appearing as red, well-demarcated eczematoid lesions, with slightly raised edges. A high degree of clinical suspicion is very important when evaluating these lesions in order to avoid misdiagnosis and delay of effective treatment. We present a case of vulvar Paget disease treated with vulvectomy.info:eu-repo/semantics/publishedVersio

    On virialization with dark energy

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    We review the inclusion of dark energy into the formalism of spherical collapse, and the virialization of a two-component system, made of matter and dark energy. We compare two approaches in previous studies. The first assumes that only the matter component virializes, e.g. as in the case of a classic cosmological constant. The second approach allows the full system to virialize as a whole. We show that the two approaches give fundamentally different results for the final state of the system. This might be a signature discriminating between the classic cosmological constant which cannot virialize and a dynamical dark energy mimicking a cosmological constant. This signature is independent of the measured value of the equation of state. An additional issue which we address is energy non-conservation of the system, which originates from the homogeneity assumption for the dark energy. We propose a way to take this energy loss into account.Comment: 15 pages, 5 figures. Accepted for publication in JCA
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