Quantitative stock-scion relationships in vine Preliminary investigations by the analysis of reciprocal graftings

The behaviour variations of a scion in association with düferent rootstocks are well known, particularly in so far as the expression of vigour is concerned. This simple effect is only an element of one of the possible break-down of the rootstockscion combination's quantitative characteristics.We analyse experiments of complete reciprocal grafting by use of two biometric models, one breaking down the variation for the "functions" (rootstock, scion and interaction), the other breaking down the variation for "genetic effects". Initial results allow us:1 - to test the interest of these two models and the parameters we propose,2 - to compute the quantitative importance of these parameters at differentgrowth stages.Relations quantitatives entre porte-greffe et greffon chez la vigne Première approche par l'analyse des greffages réciproquesChez la vigne, on observe que le comportement d'un même greffon peut varier lorsqu'on l'associe à différents porte-greffes; ceci a été sbuvent noté, particulièrement en ce qui concerne l'expression de la vigueur. Cet effet simple n'est en fait qu'un des éléments de la décomposition que l'on peut faire à partir de toute caractéristique ou performance quantitative de la combinaison du greffon et du porte-greffe.Par analogie avec l'étude des effets principaux et de leur interaction dans les associationsbinaires, l'analyse de greffages réciproques pêut être effectuée par le modèle biométrique suivant:Yij= m + pi+ gj + kijoù pi et gj sont respectivement ce que nous appelons les «fonctions» porte-greffe et greffon, et kij leur interaction. Une autre décomposition possible où apparaissent des «effets génétiques» est la suivante:Yij = m + ci + cj + sij + qij ci et cj étant les «Aptitudes Générales à l'Association» des génotypes i et j, sij leur «Aptitude Spécifique à l'Association» et qij l'effet réciproque de ces deux génotypes. Des expériences préliminaires basées sur un système de greffages réciproques complet de quatre génotypes, dont nous avons mesuré la croissance au cours de trois cycles de végétation, chacun de 120 jours, nous ont permis:1. de tester l'intérêt de ces deux modèles biométriques et celui des paramètres que nous proposons.2. de calculer l'ordre de grandeur de ces paramètres à différents stades de la croissance

Tracking the phase-transition energy in disassembly of hot nuclei

In efforts to determine phase transitions in the disintegration of highly excited heavy nuclei, a popular practice is to parametrise the yields of isotopes as a function of temperature in the form $Y(z)=z^{-\tau}f(z^{\sigma}(T-T_0))$, where $Y(z)$'s are the measured yields and $\tau, \sigma$ and $T_0$ are fitted to the yields. Here $T_0$ would be interpreted as the phase transition temperature. For finite systems such as those obtained in nuclear collisions, this parametrisation is only approximate and hence allows for extraction of $T_0$ in more than one way. In this work we look in detail at how values of $T_0$ differ, depending on methods of extraction. It should be mentioned that for finite systems, this approximate parametrisation works not only at the critical point, but also for first order phase transitions (at least in some models). Thus the approximate fit is no guarantee that one is seeing a critical phenomenon. A different but more conventional search for the nuclear phase transition would look for a maximum in the specific heat as a function of temperature $T_2$. In this case $T_2$ is interpreted as the phase transition temperature. Ideally $T_0$ and $T_2$ would coincide. We invesigate this possibility, both in theory and from the ISiS data, performing both canonical ($T$) and microcanonical ($e=E^*/A$) calculations. Although more than one value of $T_0$ can be extracted from the approximate parmetrisation, the work here points to the best value from among the choices. Several interesting results, seen in theoretical calculations, are borne out in experiment.Comment: Revtex, 10 pages including 8 figures and 2 table

Differences in daptomycin and vancomycin ex vivo behaviour can lead to false interpretation of negative blood cultures

AbstractIn clinical studies on bacteraemia, the negativity of blood cultures is an important endpoint for comparing the efficacy of different therapeutic regimens. In FAN° anaerobic blood culture medium (BacT/ALERT system), daptomycin displayed increased MIC against Staphylococcus aureus and improved abolishment of its carryover effect in charcoal when compared with vancomycin. Differences between these two drugs can lead to a false interpretation of negative blood cultures. To compare different antibiotic regimens for the treatment of bacteraemia, preliminary studies are mandatory to ensure that ex vivo antibiotic behaviour is similar in the blood-culture system used

Rich polymorphism of a rod-like liquid crystal (8CB) confined in two types of unidirectional nanopores

We present a neutron and X-rays scattering study of the phase transitions of 4-n-octyl-4'-cyanobiphenyl (8CB) confined in unidirectional nanopores of porous alumina and porous silicon (PSi) membranes with an average diameter of 30 nm. Spatial confinement reveals a rich polymorphism, with at least four different low temperature phases in addition to the smectic A phase. The structural study as a function of thermal treatments and conditions of spatial confinement allows us to get insights into the formation of these phases and their relative stability. It gives the first description of the complete phase behavior of 8CB confined in PSi and provides a direct comparison with results obtained in bulk conditions and in similar geometric conditions of confinement but with reduced quenched disorder effects using alumina anopore membranesComment: Accepted in EPJ E - Soft Matte

The liquid to vapor phase transition in excited nuclei

For many years it has been speculated that excited nuclei would undergo a liquid to vapor phase transition. For even longer, it has been known that clusterization in a vapor carries direct information on the liquid- vapor equilibrium according to Fisher's droplet model. Now the thermal component of the 8 GeV/c pion + 197Au multifragmentation data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model, thus providing the strongest evidence yet of the liquid to vapor phase transition.Comment: four pages, four figures, first two in color (corrected typo in Ref. [26], corrected error in Fig. 4

Thermally-induced expansion in the 8 GeV/c π−\pi^- + 197^{197}Au reaction

Fragment kinetic energy spectra for reactions induced by 8.0 GeV/c $\rm{\pi^-}$ beams incident on a $\rm{^{197}}$Au target have been analyzed in order to deduce the possible existence and influence of thermal expansion. The average fragment kinetic energies are observed to increase systematically with fragment charge but are nearly independent of excitation energy. Comparison of the data with statistical multifragmentation models indicates the onset of extra collective thermal expansion near an excitation energy of E*/A $\rm{\approx}$ 5 MeV. However, this effect is weak relative to the radial expansion observed in heavy-ion-induced reactions, consistent with the interpretation that the latter expansion may be driven primarily by dynamical effects such as compression/decompression.Comment: 12 pages including 4 postscript figure

Palladium‐Catalyzed Cross‐Dehydrogenative Coupling of <i>o</i>‐Xylene: Evidence of a New Rate‐Limiting Step in the Search for Industrially Relevant Conditions

An efficient cross‐dehydrogenative coupling of o‐xylene under neat conditions, which brings important industrial benefits towards the synthesis of a monomer used in polyimide resins, is reported. The catalyst based on the combination of Pd/N ligand/carboxylate=1:1:2 does not require a Cu cocatalyst and proceeds at 11 bar of O2 pressure. Evaluation of the deuterium kinetic isotope effect (KIE) provides evidence for three different rate‐determining steps, which depend on the reaction conditions (medium, temperature). Under the reported neat conditions, the dissociation of a carboxylate‐bridged dimer to generate a more reactive monometallic Pd species is proposed to be the rate‐limiting step