553 research outputs found

    THE EPIDERMIS AND CYCLIC AMP

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73687/1/j.1365-2133.1974.tb06390.x.pd

    Photoionization Of Atomic Oxygen At The Multiplet Term Level From 20 To 212 Ev

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    The valence shell photoionization branching ratios of atomic oxygen are measured at the multiplet term level in a synchrotron-radiation-based electron spectrometry experiment and calculated using the multiconfiguration Hartree-Fock (MCHF) method for photon energies between 20 and 212 eV. The 2p (S-4,D-2,P-2) branching ratios, 2s P-2 to 2s P-4 intensity ratio, and 2s to 2p cross-section ratio for removal of a 2s of 2p electron are presented, and satisfactory agreement between the experiment and the MCHF calculation is found. In addition, the relative photoionization cross section is measured between 24 and 122 eV and is compared with calculations and a previous absolute cross-section measurement. Good agreement between the experimental and MCHF results is seen

    Generalized Central Limit Theorem and Renormalization Group

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    We introduce a simple instance of the renormalization group transformation in the Banach space of probability densities. By changing the scaling of the renormalized variables we obtain, as fixed points of the transformation, the L\'evy strictly stable laws. We also investigate the behavior of the transformation around these fixed points and the domain of attraction for different values of the scaling parameter. The physical interest of a renormalization group approach to the generalized central limit theorem is discussed.Comment: 16 pages, to appear in J. Stat. Phy

    Semantic Web Services for Multi-Agent Systems Interoperability

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    Agent-based technologies are often used including existing web services. The outputs of some services are also frequently used as inputs for other services, including other MAS. However, while agent-based technologies can be used to provide services, these are not described using the same semantic web technologies web services use, which makes it difficult to discover, invoke and compose them with web services seamlessly. In this paper, we analyse different agent-based technologies and how these can be described using extensions to OWL-S. Additionally, we propose an architecture that facilitates these services’ usage, where services of any kind can be registered and executed (semi-)automatically.The present work has been developed under the PIANISM Project (ANI|P2020 40125) and has received funding from FEDER Funds through NORTE2020 program and from National Funds through Fundação para a CiĂȘncia e a Tecnologia (FCT) under the project UID/EEA/00760/2019. Gabriel Santos is supported by national funds through FCT PhD studentship with reference SFRH/BD/118487/2016.info:eu-repo/semantics/publishedVersio

    The impact of the Val158Met catechol-O-methyltransferase genotype on neural correlates of sad facial affect processing in patients with bipolar disorder and their relatives

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    Background - The Met allele of the catechol-O-methyltransferase (COMT) valine-to-methionine (Val158Met) polymorphism is known to affect dopamine-dependent affective regulation within amygdala-prefrontal cortical (PFC) networks. It is also thought to increase the risk of a number of disorders characterized by affective morbidity including bipolar disorder (BD), major depressive disorder (MDD) and anxiety disorders. The disease risk conferred is small, suggesting that this polymorphism represents a modifier locus. Therefore our aim was to investigate how the COMT Val158Met may contribute to phenotypic variation in clinical diagnosis using sad facial affect processing as a probe for its neural action. Method - We employed functional magnetic resonance imaging to measure activation in the amygdala, ventromedial PFC (vmPFC) and ventrolateral PFC (vlPFC) during sad facial affect processing in family members with BD (n=40), MDD and anxiety disorders (n=22) or no psychiatric diagnosis (n=25) and 50 healthy controls. Results - Irrespective of clinical phenotype, the Val158 allele was associated with greater amygdala activation and the Met allele with greater signal change in the vmPFC and vlPFC. Signal changes in the amygdala and vmPFC were not associated with disease expression. However, in the right vlPFC the Met158 allele was associated with greater activation in all family members with affective morbidity compared with relatives without a psychiatric diagnosis and healthy controls. Conclusions - Our results suggest that the COMT Val158Met polymorphism has a pleiotropic effect within the neural networks subserving emotional processing. Furthermore the Met158 allele further reduces cortical efficiency in the vlPFC in individuals with affective morbidity

    The liquid-vapor interface of an ionic fluid

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    We investigate the liquid-vapor interface of the restricted primitive model (RPM) for an ionic fluid using a density-functional approximation based on correlation functions of the homogeneous fluid as obtained from the mean-spherical approximation (MSA). In the limit of a homogeneous fluid our approach yields the well-known MSA (energy) equation of state. The ionic interfacial density profiles, which for the RPM are identical for both species, have a shape similar to those of simple atomic fluids in that the decay towards the bulk values is more rapid on the vapor side than on the liquid side. This is the opposite asymmetry of the decay to that found in earlier calculations for the RPM based on a square-gradient theory. The width of the interface is, for a wide range of temperatures, approximately four times the second moment correlation length of the liquid phase. We discuss the magnitude and temperature dependence of the surface tension, and argue that for temperatures near the triple point the ratio of the dimensionless surface tension and critical temperature is much smaller for the RPM than for simple atomic fluids.Comment: 6 postscript figures, submitted to Phys. Rev.

    Autofluorescence endoscopic spectro-imaging and 2D-cartography for in situ localisation and diagnosis of cancerous lesions

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    Early diagnosis is the most efficient way to struggle against cancer. Among all the existing techniques, optical methods (photodiagnosis from NUV to NIR) show important characteristics required by the physicians : high sensitivity, non-ionising radiations and non-traumatic measurements. They are particularly well suited to the detection of cancers in hollow organs, that are usually superficial and hardly visible with classical endoscopy. This paper describes a methodological approach based on the use of tissue autofluorescence, applicable in clinical endoscopy, and leading to the definition of diagnosis indicators from the spectral parameters. Following a state-of-the-art on autofluorescence spectroscopic (LIFS) and endoscopic imaging methods, we present the efficiency of fibered LIFS in terms of sensitivity and specificity for the diagnosis of esophagus cancerous lesions (clinical study over 25 patients). We then present the technological characteristics of an autofluorescence endoscopic imaging prototype developed in our labs as well as its calibration. A second part is devoted to endoscopic image registration and mosaicing and to optics aberration correction in perspective of the automatic construction of a panoramic image (cartography) of the organ’s explored areas. Finally, exploiting the fluorescence data provided by the imager, the feasibility of the superimposition of spatial and spectral information is validated with a phantom.Le diagnostic prĂ©coce est le moyen le plus efficace de lutte contre le cancer. Parmi toutes les techniques possibles, les mĂ©thodes optiques (photodiagnostic du proche UV au proche IR) prĂ©sentent des caractĂ©ristiques importantes recherchĂ©es par les mĂ©decins : grande sensibilitĂ©, radiations non ionisantes et mesures atraumatiques. Elles sont particuliĂšrement bien adaptĂ©es Ă  la dĂ©tection des cancers des organes creux, par nature superficiels et difficilement dĂ©celables en endoscopie classique. Cet article dĂ©crit une approche mĂ©thodologique fondĂ©e sur l’exploitation de l’autofluorescence tissulaire, applicable en endoscopie clinique, et conduisant Ă  l’élaboration d’indicateurs diagnostiques issus des paramĂštres spectraux. AprĂšs un Ă©tat de l’art sur les mĂ©thodes spectroscopiques (LIFS) et d’imagerie endoscopique d’autofluorescence, nous montrons l’efficacitĂ© de la LIFS fibrĂ©e en terme de sensibilitĂ© et de spĂ©cificitĂ© pour le diagnostic de lĂ©sions cancĂ©reuses de l’oesophage (Ă©tude clinique sur 25 patients). Nous prĂ©sentons ensuite les caractĂ©ristiques technologiques et le calibrage du prototype d’imageur endoscopique d’autofluorescence dĂ©veloppĂ©. Une seconde partie traite du prĂ©-traitement, du recalage et du mosaĂŻquage des images endoscopiques appliquĂ©s Ă  la construction automatique d’une image panoramique (cartographie) Ă  partir de sĂ©quences vidĂ©os des zones explorĂ©es de l’organe. Finalement, en exploitant les informations de fluorescence fournies par l’imageur, la faisabilitĂ© d’une superposition des informations spatiale et spectrale est validĂ©e sur fantĂŽme

    Direct probe of Mott-Hubbard to charge-transfer insulator transition and electronic structure evolution in transition-metal systems

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    We report the most direct experimental verification of Mott-Hubbard and charge-transfer insulators through x-ray emission spectroscopy in transition-metal (TM) fluorides. The p-d hybridization features in the spectra allow a straightforward energy alignment of the anion-2p and metal-3d valence states, which visually shows the difference between the two types of insulators. Furthermore, in parallel with the theoretical Zaanen-Sawatzky-Allen diagram, a complete experimental systematics of the 3d Coulomb interaction and the 2p-3d charge-transfer energy is reported and could serve as a universal experimental trend for other TM systems including oxides
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