Morphological responses of shoot apices of grapevine cultured in vitro Effects of cytokinins in routine subculturing

Shoots derived from shoot apices of grapevine were repeatedly subcultured on nutrient media containing difterent concentrations of 6-benzylaminopurine (BAP) and zeatin riboside (ZR). Optimum shoot proliferation resulted with a combination of the cytokinins, each at 2 mg/l. Shoots produced with ZR only (10 mg/l) elongated rapidly, were slim and erect, with almost normal leaves. With BAP at 2 mg/l alone and in combination with low concentrations of ZR {2 mg/l) proliferated shoots were thicker, often branched, less elongated, curved and not uniform in size. Leaves were atypical. It was concluded that application of cytokinins should be useful in the production of large numbers of grapevine clones.Die morphologischen Reaktionen in vitro kultivierter Rebentriebspitzen Der Einfluß von Cytokininen bei aufeinanderfolgenden SubkulturenAus Rebentriebspitzen gewonnene Triebe wurden wiederholt auf Nährmedien mit unterschiedlichen Konzentrationen von 6-Benzylaminopurin (BAP) und Zeatinribosid (ZR) übertragen. Eine optimale Triebvermehrung wurde mit 2 mg BAP/l in Verbindung mit 2 mg ZR/1 erzielt. Ohne BAP, nur mit 10 mg ZR/l erzeugte Triebe wuchsen rasch in die Länge, waren schlank und aufrecht und besaßen nahezu normale Blätter. Mit 2 mg BAP/l, allein oder mit 2 mg ZR/1 kombiniert, entstanden unterschiedlich große, gestauchte, oftmals verzweigte Triebe von gekrümmtem Wuchs und mit atypischen Blättern. Cytokinine dürften ein wertvolles Hilfsmittel darstellen, um Rebenklone in großer Zahl zu erzeugen

The relationship between various risk factors and the cost of equity premium implied by analysts' forecasts on the New York Stock Exchange

The cost of equity is used extensively for capital allocation decisions, and the various methods used to estimate it often result in materially different outcomes. A model of the impact of known risk factors on the implied cost of equity used by equity analysts, who are seen as informed market participants, could be a guideline and sense check for other professionals estimating cost of equity for capital allocation decisions. This study, an implementation of Arbitrage Pricing Theory, attempts to create a parsimonious model of factors that are associated with the implied cost of equity premium utilised by equity analysts on the New York Stock Exchange ("NYSE"). After limiting the sample to NYSE-listed companies that were primarily exposed to US macro-economic conditions and were likely to be valued overwhelmingly on a going-concern basis, the test sample consisted of 5,343 company quarters covering the period 2006 to 2015. In the first part of the methodology, sixteen factors identified from previous literature as possibly influencing the cost of equity were tested for their association with the implied equity risk premium, as calculated from analysts' two-year earnings forecasts and target share prices using the Easton-method. Only those factors that were statistically significantly associated with the implied cost of equity were retained for the second part of the methodology, in which mixed effects modelling and optimisation using the Akaike information criterion was used to find a parsimonious model linking the statistically most significant factors to the implied cost of equity. The final model could explain 40% of the variation in implied risk premium by the fixed effects (specified variables), and 62% when the random effects (observable effects of unspecified variables) were included. The study found that the risk free rate was most strongly (and negatively) associated with the size of the implied equity risk premium. Other factors that are statistically significantly associated with the implied equity risk premium are the two-year beta (+), the profitability dummy variable (-), return on equity (-), two-year share price volatility (+), long-term growth (+), Market momentum (+), and the debt to equity ratio (+). It was further found that not all factors which have historically been shown to influence returns are significantly associated with implied cost of equity estimates, which is contrary to expectations in a fully efficient market, where the only difference in the two would result from the information that changes cash flow expectations or the risk profile of the cash flows. This study contributes to the current body of literature on cost of equity in the following ways: • To the author's knowledge, this study combines a far wider array of factors of all types than any of the previous studies on the topic, and uses target prices rather than market prices to calculate the implied cost of equity premium. • The study uses the adaptive and recursive option valuation model to eliminate companies for which the testing would not be relevant. • The study used mixed effects modelling to measure the impact of the various factors on the cost of equity premium

On Algorithms Based on Joint Estimation of Currents and Contrast in Microwave Tomography

This paper deals with improvements to the contrast source inversion method which is widely used in microwave tomography. First, the method is reviewed and weaknesses of both the criterion form and the optimization strategy are underlined. Then, two new algorithms are proposed. Both of them are based on the same criterion, similar but more robust than the one used in contrast source inversion. The first technique keeps the main characteristics of the contrast source inversion optimization scheme but is based on a better exploitation of the conjugate gradient algorithm. The second technique is based on a preconditioned conjugate gradient algorithm and performs simultaneous updates of sets of unknowns that are normally processed sequentially. Both techniques are shown to be more efficient than original contrast source inversion.Comment: 12 pages, 12 figures, 5 table

Effect of hot-water treatments on vine cuttings and one-yearold grafts

One-year-old grape cuttings were submerged in hot water at temperatures of 45, 50, 55, 60 and 65 °C respectively. Intervals for each temperature range were 1, 5, 10, 30 and 60 min. Callusing was inhibited at temperatures of 55 °C for longer than 10 min. Optimum callusing was obtained at 50 °C for 30 min and 60 °C for 1 min. Bud-burst was also inhibited at higher temperatures and longer exposure times (above 55 °C with intervas longer than 1 min). One-year-old grafts could not survive temperatures above 60 °C at immersion times of longer than 1 min.Einfluß der Warmwasserbehandlung auf Rebenstecklinge und einjährige PfropfrebenUnbewurzelte Stecklinge aus einjährigem Holz von Vitis vinifera cv. Cabernet Sauvignon wurden in 45, 50, 55, 60 und 65 oc heißes Wasser getaucht. Die Behandlungsdauer betrug jeweils 1, 5, 10, 30 und 60 min. Die Kallusbildung wurde im Temperaturbereich von 55 oc gehemmt, wenn die Einwirkungsdauer 10 min überstieg. Eine optimale Kallusbildung erfolgte bei 50 °C - 30 min und 60 °C - 1 min. Der Knospenaustrieb wurde bei höheren Temperaturen und längeren Behandlungszeiten (über 55 oc und mehr als 1 min) ebenfalls gehemmt. Einjährige, bewurzelte Pfropfreben von Cabernet Sauvignon/99 R. überlebten Temperaturen über 60 °C nicht, wenn sie länger als 1 min eingetaucht wurden

BDP de Saône-et-Loire - synthèse du rapport d\u27activité 2007

Synthèse du rapport d\u27activité 2007 de la BDP de Saône-et-Loir

Anatomical responses to cytokinins of abscised grapevine shoot apices cultured in vitro

Responses of excised shoot apices of V. vinifera L. cv. Chenin blanc to different cytokinin treatments were studied at various intervals (days) after the start of in vitro culture, using light and scanning electron microscopy. Results clearly indicated that in vitro produced shoots were of axillary origin. Shoot clusters were produced by the enhanced release of axillary meristems from apical dominance, due to the application of 6-benzylaminopurine (BAP) singly as well as in combination with zeatin riboside (ZR). Axillary meristems on these axillary shoots were subsequently released from apical dominance, thus giving rise to shoot clusters of high densities. Shoot clusters induced by ZR alone were less dense, probably due to an initial delay in elongation of axillary meristems nearest to the main apical meristem of the shoot. However, elongation of axillary meristems lower down the axes proceeded strongly in the presence of ZR. Application of BAP resulted in more pronounced release of axillary meristems from apical dominance than with ZR

Effects of cytokinins on elongation, proliferation and total mass of shoots derived from shoot apices of grapevine cultured in vitro

Shoot apices of grapevine (Vitis vinifera L.) were cuUured on a nutrient medium containing differerut concentrations singly and in combination of 6-benzylaminopurine (BAP) and zeatin riboside (ZR). lf supplied separately, maximum elonga0tion and shoot proliferation resulted with BAP at 2 mg/l or with ZR at 10 mg/l. Both processes were inhibited by BAP at 5 mg/l. Combined applications of ZR (even at 10 mg/l failed in cancelling this inhibition. Optimum shoot proliferation resulted with the cytokinins in combination, provided the concentration of BAP did not exceed 2 mg/l.Der Einfluß von Cytokininen auf Längenwachstum, Vermehrung und Gesamtmasse der aus Rebentriebspitzen bei in-vitro-Kultur entstandenen TriebeTriebspitzen der Rebe (Vitis vinifera L.) wurden auf einem Nährmedium kultiviert, das - einzeln und kombiniert - unterschiedliche Konzentrationen von 6-Benzylaminopurin (BAP) und Zeatinribosid (ZR) enthielt. Bei getrennter Anwendung der Wachstumsregulatoren förderten 2 mg BAP/l oder 10 mg ZR/l das Längenwachstum und die Triebvermehrung . am meisten. Beide Vorgänge wurden durch 5 mg BAP/l unterdrückt. Diese Hemmung konnte auch nicht durch zusätzliche Anwendung von ZR, selbst nicht in der Konzentration von 10 mg/l, aufgehoben werden. Eine optimale Triebvermehrung wurde durch ZR in Verbindung mit BAP erzielt, falls die BAP-Konzentration 2 mg/l nicht überschritt

BDP de Saône-et-Loire - Rapport d\u27activités 2007

Rapport d\u27activité de la Bibliothèque Départementale de Prêt de Saône-et-Loire, pour l\u27année 2007. ce rapport revient sur la bibliothèque départementale et son réseau (moyens, fourniture de documents, PEB, formation, animation, publication, promotion...). Il revient ensuite sur le cadre du réseau (taille des communes, sections proposées, répartition des bibliothèques de niveau 1.2 et 3, point lectures et dépôts). Le rapport revient enfin sur chacune de ces catégories de manière plus précise (budgets, personnels, prêts, collections, animation etc.). Un dernier point s\u27attarde sur les bibliothèques centre de ressources, établissements dans le département disposant d\u27un rôle documentaire particulier, et sur les bibliothèques intercommunales