4 research outputs found
ULTRAVIOLET ABSORPTION SPECTRUM OF MERCURY IN Ne, Ar, Kr, AND Xe MATRICES
No full text J.-Y. Roncin and N. Damany-Astoin, Compt. Rend, 253, 835 (1961). b M. McCarty, Jr. and G. W. Robinson. J. Chem. Phys. 56, 723 (1959), and Mol. Phys. 3, 301 (1960).Author Institution: Inorganic Materials Research Division and Chemistry Department, University of CaliforniaThe absorption spectrum of mercury in Ne, Ar, Kr, and Xe matrices in the region from 2000 to has been studied as a function of temperature, deposition rate, and concentration. The fine structure of the main absorption, attributed to the transition, has been re-examined. The results are compared with those of other workers, and an apparently contradictory observation in the case of is discussed
INTERMOLECULAR POTENTIAL OF EXCITED ATOMS AND MOLECULES FROM MATRIX SHIFTS.
No full text J.-Y. Roncin, J. Mol. Spectry, 26, 105 (1968). J.-Y. Roncin, N. Damany and B. Vodar, Chem. Phys. Letters, March 1969.Author Institution: Laboratoire des Hautes, Pressions, C.N.R.S., Bellevue France and National Research Council of Canada Division of Pure PhysicsThe experimental shifts and broadening of far u.v. transitions of trapped species have so far permitted only qualitative conclusions concerning the dimensions of the excited In particular the matrix isolation technique has strikingly shown the profound difference in behavior of trapped molecules according to the nature of the transition; valence transitions are little affected whereas Rydberg transitions are strongly Enough experimental data are now available to attempt a quantitative estimation of the dimension of some excited states on the basis of a simple Lennard-Jones intermolecular potential . The values of and , computed for some excited states of Xe, Kr, Hg, CO, NO and , are given below: [FIGURE] During the year 1969, J.-Y. Roncin has been a Postdoctoral Fellow at the Division of Pure Physics, National Research Council of Canada, Ottawa, Canada
Oedeme hépatique
No full textThe author does a “mise au point” upon the theme, reminding Mac Swinney and De Giovanni’s first works; these separated his pathogeny from mechanical theory which predominated then; he continues exposing De Damany’s principal work to establish after the clinical tableau with all its varieties, and to follow later with the revision of every invoked theory to explain these types of oede- mes, and he finishes with the exposition of toxic factors of the Imidazoles group which hydropigenic roll has been experimentally established. He arrives at the conclusion that these oedemes don’t obey to an only causal but to a group of them —mechanical, endocrinal, nervous, tumoral and chemical— intimately connected among them.L'auteur fait une mise au point sur le théme, rappelant les premiers travaux de Mac Swinney et ceux de De Giovanni que séparaient son pathogénie de la théorie méchanique qui regnait alors; il continue en exposant les travaux principaux de Le Damany, pour établir aprés le tableau clinique avec toutes ses variétés et suivre plus tard avec la revisión de toutes les théories nommées pour expliquer ces types d’oedémes, finissant avec l’exposition des facteurs toxiques du groupe des Imidazoles dont role hydropigéne fut expérimentellement établi, Il arrive a la conclusion que ces oedémes n’obéissent pas a une causal unique mais á un certain groupe d’etíx —méchaniques, endocrines, nerveux, tumoraux et chimiques — intimement connexes entre eux.Facultad de Ciencias Médica
Pirates of the Caribbean (and elsewhere): three-legged lizards and the study of evolutionary adaptation.
No full textInternational audienceNatural selection is widely considered responsible for the fit between organisms and their environment. Lizard limb length variation is a paradigmatic example: studies have shown that limb length differences tightly correlate with habitat use among species, while small differences in limb length between individuals can affect biomechanical function, fitness, and survival within populations. It has therefore been surprising for many field biologists to find otherwise-healthy wild lizards with damaged or missing limbs, appearing to challenge associated expectations of substantial fitness costs. We document limb loss (from a foot to an entire limb) in 58 lizard species, with all cases showing healed limbs and many lizards appearing robust and healthy. Data indicate that limb-deficient lizards typically comprise less than 1% of populations and often exhibit body condition, sprint speed performance, and survival comparable to limb-intact individuals. We discuss the implications of these findings for how evolutionary adaptation is studied and understood in natural populations and provide a perspective on conventional assumptions about the strength and ubiquity of selection pressures on seemingly critical traits. Is natural selection always as omnipresent as Darwin envisioned it to be
