On the Hypothetical Model of Childbearing Iconography in the Octateuchs

Στην παρούσα μελέτη προτείνεται να ερμηνευθεί η εικονογραφία γεννήσεων στις Οκτατεύχους ως ένα σχήμα με δύο πτυχές, που εικονίζει συνολικά μια διαδικασία τοκετού. Διατυπώνεται η άποψη ότι αυτή η εικονογραφία ανάγεται σχεδόν με βεβαιότητα σε ένα χειρόγραφο των Γυνακείων του Σωρανού, που ήταν πιθανότατα εικονογραφημένο και ότι ο αντιγραφέας περιόρισε τον ανεπτυγμένο εικονογραφικό τύπο –τόσο της στιγμής του τοκετού όσο και των φάσεων μετά από αυτόν-στα πιο ουσιαστικά στοιχεία του, χωρίς να μειώσει τη σαφήνεια της σκηνής.The present study proposes to see the childbearing iconography in the Octateuchs as a two-fold scheme depicting a continuous birth narrative. It is suggested that this iconography almost certainly drew specifically on a manuscript of Soranus’ Gynaikeia, most likely illuminated, and that the copyist abridged the full iconographic formulae-both that of giving birth and that of the post birth phases-to its most essential elements, without detracting from the legibility of the scene.

On the Hypothetical Model of Childbearing Iconography in the Octateuchs

Στην παρούσα μελέτη προτείνεται να ερμηνευθεί η εικονογραφία γεννήσεων στις Οκτατεύχους ως ένα σχήμα με δύο πτυχές, που εικονίζει συνολικά μια διαδικασία τοκετού. Διατυπώνεται η άποψη ότι αυτή η εικονογραφία ανάγεται σχεδόν με βεβαιότητα σε ένα χειρόγραφο των Γυνακείων του Σωρανού, που ήταν πιθανότατα εικονογραφημένο και ότι ο αντιγραφέας περιόρισε τον ανεπτυγμένο εικονογραφικό τύπο –τόσο της στιγμής του τοκετού όσο και των φάσεων μετά από αυτόν-στα πιο ουσιαστικά στοιχεία του, χωρίς να μειώσει τη σαφήνεια της σκηνής.The present study proposes to see the childbearing iconography in the Octateuchs as a two-fold scheme depicting a continuous birth narrative. It is suggested that this iconography almost certainly drew specifically on a manuscript of Soranus’ Gynaikeia, most likely illuminated, and that the copyist abridged the full iconographic formulae-both that of giving birth and that of the post birth phases-to its most essential elements, without detracting from the legibility of the scene.

Surface oxidation of liquid Sn

We report the results of an x-ray scattering study that reveals oxidation kinetics and formation of a previously unreported crystalline phase of SnO at the liquid-vapour interface of Sn. Our experiments reveal that the pure liquid Sn surface does not react with molecular oxygen below an activation pressure of \~5.0*10-6 Torr. Above that pressure a rough solid Sn oxide grows over the liquid metal surface. Once the activation pressure has been exceeded the oxidation proceeds at pressures below the oxidation pressure threshold. The observed diffraction pattern associated with the surface oxidation does not match any of the known Sn oxide phases. The data have an explicit signature of the face-centred cubic structure, however it requires lattice parameters that are about 9% smaller than those reported for cubic structures of high-pressure phases of Sn oxides. Keywords: X-ray scattering, diffraction, and reflection; Oxidation; Surface chemical reaction; Surface structure, morphology, roughness, and topography; Tin; Tin oxides; Liquid surfaces; Polycrystalline thin filmsComment: 18 pages, 6 figures, 1 table; Submitted to Surface Scienc

Direct and indirect modulation of neuropeptide Y gene expression in response to hypoglycemia in rat arcuate nucleus

AbstractExpression of neuropeptide Y (Npy) heteronuclear (hn) RNA, an indicator of gene transcription, was significantly increased in the arcuate nucleus of rats 30min after insulin injection. Npy hnRNA levels were also increased significantly in response to hypoglycemia in rats in which the hypothalamus was deafferentated, although the absolute levels were significantly lower than in sham-operated rats. Direct effects of lowering glucose levels on Npy gene expression were also confirmed in hypothalamic organotypic cultures. Thus, Npy gene transcription in the arcuate nucleus increases rapidly in response to hypoglycemia, and both direct and indirect inputs are involved in the rapid upregulation

Glutamate regulation of calcium and IP3 oscillating and pulsating dynamics in astrocytes

Recent years have witnessed an increasing interest in neuron-glia communication. This interest stems from the realization that glia participates in cognitive functions and information processing and is involved in many brain disorders and neurodegenerative diseases. An important process in neuron-glia communications is astrocyte encoding of synaptic information transfer: the modulation of intracellular calcium dynamics in astrocytes in response to synaptic activity. Here, we derive and investigate a concise mathematical model for glutamate-induced astrocytic intracellular Ca2+ dynamics that captures the essential biochemical features of the regulatory pathway of inositol 1,4,5-trisphosphate (IP3). Starting from the well-known two-state Li-Rinzel model for calcium-induced-calcium release, we incorporate the regulation of the IP3 production and phosphorylation. Doing so we extended it to a three-state model (referred as the G-ChI model), that could account for Ca2+ oscillations triggered by endogenous IP3 metabolism as well as by IP3 production by external glutamate signals. Compared to previous similar models, our three-state models include a more realistic description of the IP3 production and degradation pathways, lumping together their essential nonlinearities within a concise formulation. Using bifurcation analysis and time simulations, we demonstrate the existence of new putative dynamical features. The cross-couplings between IP3 and Ca2+ pathways endows the system with self-consistent oscillator properties and favor mixed frequency-amplitude encoding modes over pure amplitude modulation ones. These and additional results of our model are in general agreement with available experimental data and may have important implications on the role of astrocytes in the synaptic transfer of information.Comment: 42 pages, 16 figures, 1 table. Figure filenames mirror figure order in the paper. Ending "S" in figure filenames stands for "Supplementary Figure". This article was selected by the Faculty of 1000 Biology: "Genevieve Dupont: Faculty of 1000 Biology, 4 Sep 2009" at http://www.f1000biology.com/article/id/1163674/evaluatio