Vitreous GeO2 response to shock loading

Shock wave profiles in vitreous GeO2 (6.56 Mg/m^3) under planar loading were measured using stress gauges to 14 GPa. New and previous data yield Hugoniot: D=0.974 (km/s)+1.711 u for shocks of 6 to 40 GPa. We show that the phase change from 4- to 6-fold coordination of Ge+4 with O–2 in vitreous GeO2 occurs from 4 to 15 GPa. Hugoniots of vitreous GeO2 and SiO2 are found to approximately coincide if the pressure in SiO2 is scaled by the ratio of SiO2 to GeO2 initial density

Revealing the details of vortex core precession in cyclones by means of large-eddy simulation

Acknowledgement The authors wish to thank A.J. Hoekstra (T.U. Delft) for making available the experimental data.Peer reviewedPostprin

Role of Paclobutrazol and Ethephon in Reproductive Growth of 'Allahabad Safeda' Guava (Psidium guajava L.) Plants at Different Spacing

A study on 4-year 'Allahabad Safeda' guava plants was made to assess the influence of Paclobutrazol (PP 333), [(2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4 triazol-1-yl) pentan-3-ol], a gibberellin-inhibitor, and Ethephon [(2-chloroethyl) phosphonic acid], a vegetative growth inhibitor and a ripening promoter, on reproductive growth of plants. Treatments in the form of foliar application at 500 and 1000 ppm were applied consecutively during March 2007 and 2008 on plants at 6m x 2m, 6m x 3m, 6m x 4m and 6m x 5m spacing. Maximum flowering and fruit set was recorded in paclobutrazol treated plants in both rainy and winter crops. Ethephon reduced flower bud density (FBD) and fruit set during both the cropping seasons. However, Ethephon treated plants exhibited slightly higher fruit retention. Ethephon advances fruit maturity by upto a week during rainy season and two weeks during winter season. Paclobutrazol treated plants exhibited significantly higher fruit number, fruit yield, yield efficiency, fruiting density compared to Ethephon treated and control plants. Reproductive growth of plants at wider spacing of 6m x 5m and 6m x 4m significantly improved compared to closer spacings of 6m x 2m and 6m x 3m during both cropping seasons. Plants at wider spacing responded better to Paclobutrazol applications with respect to flowering and fruiting

In vivo development of ovule in seedless and seeded cultivars of grapes (Vitis vinifera L.)- a particular reference to in ovulo embryo culture

Ovule development was examined in the three seedless cvs Perlette, Thompson Seedless, Beauty Seedless and the seeded cv. Anab-e-Shahi, to identify the proper developmental stage of the embryo for in ovulo embryo culture. The number of shrivelled ovules started increasing 20 d post anthesis. At the same time, the number of viable ovules started declining in all the seedless cultivars. Amongst seedless cultivars, the growth of ovules was least in cvs Thompson Seedless and Beauty Seedless. The ovule development was faster in Anab-e-Shahi as compared to all the seedless cultivars. Total number of ovules per berry declined 20 and 30 d post anthesis in cvs Beauty Seedless and Perlette, respectively. Keeping in view the above mentioned parameters, the embryos in seedless cultivars of grapes may be rescued in vitro prior to 20 d post anthesis to obtain plantlets from these abortive ovules.Die Entwicklung der Samenanlagen bei kernlosen und kernhaltigen Rebsorten (Vitis vinifera L.) in vivo im Hinblick auf die Embryokultur in vitroUm das geeignetste Entwicklungsstadium der Embryonen für ihre in-vitro-Kultur zu ermitteln, wurde bei den drei kernlosen Rebsorten Perlette, Thompson Seedless und Beauty Seedless sowie der kernhaltigen Sorte Anab-e-Shahi die Entwicklung der Samenanlagen verfolgt. Die Anzahl geschrumpfter Samenanlagen begann 20 d nach der Anthese anzusteigen. Gleichzeitig setzte bei allen kernlosen Sorten die Abnahme der vitalen Samenanlagen ein. Von den kernlosen Sorten zeigten Thompson Seedless und Beauty Seedless das schwächste Wachstum der Samenanlagen. Bei Anab-e-Shahi entwickelten sich die Samenanlagen schneller als bei den drei kernlosen Sorten. Bei Beauty Seedless und Perlette ging die Gesamtzahl der Samenanlagen 20 bzw. 30 d nach der Anthese zurück. Unter Berücksichtigung der oben genannten Entwicklungszeiten sollten die Embryonen binnen 20 d nach der Anthese in Kultur genommen werden, um aus den später absterbenden Samenanlagen in-vitro-Pflanzen zu gewinnen

In vitro plant regeneration in seedless grapes (Vitis vinifera L.)

Young leaves, shoot apices, nodal and internodal segments from mature field-grown grapevines (Vitis vinifera L.) cvs Thompson Seedless and Perlette were cultured on MS medium containing different concentrations and combinations of NAA, 2,4-D, Kin and BAP. The genotype, nature of explant and chemical composition of medium affected the callusing frequency and type of callus. The media containing auxins produced friable, soft and creamish white to green calli. Such calli turned brown and died within 4-6 weeks. The medium containing BAP or Kin produced green compact and nodular calli. The subculturing of green nodular calli on MS basal medium induced 20.0 and 12.5 % rooting in cvs Perlette and Thompson Seedless respectively. Subculturing of calli on MS medium containing BAP (2 mg/l) resulted in 12.1 % complete plant regeneration in Thompson Seedless, cv. Perlette failed to regenerate. Adventitious shoots developed in 65.4 and 50.0 % of the cases from the in vitro derived leaves of Thompson Seedless and Perlette when cultured on MS medium containing BAP (2 mg/l). More than 85 % of the adventitious shoots of both the cultivars rooted successfully on MS medium containing IBA (1 mg/l)

Three-Omega Thermal-Conductivity Measurements with Curved Heater Geometries

The three-omega method, a powerful technique to measure the thermal conductivity of nanometer-thick films and the interfaces between them, has historically employed straight conductive wires to act as both heaters and thermometers. When investigating stochastically prepared samples such as two-dimensional materials and nanomembranes, residue and excess material can make it difficult to fit the required millimeter-long straight wire on the sample surface. There are currently no available criteria for how diverting three-omega heater wires around obstacles affects the validity of the thermal measurement. In this Letter, we quantify the effect of wire curvature by performing three-omega experiments with a wide range of frequencies using both curved and straight heater geometries on SiO$_2$/Si samples. When the heating wire is curved, we find that the measured Si substrate thermal conductivity changes by only 0.2%. Similarly, we find that wire curvature has no significant effect on the determination of the thermal resistance of a $\sim$65 nm SiO$_2$ layer, even for the sharpest corners considered here, for which the largest measured ratio of the thermal penetration depth of the applied thermal wave to radius of curvature of the heating wire is 4.3. This result provides useful design criteria for three-omega experiments by setting a lower bound for the maximum ratio of thermal penetration depth to wire radius of curvature.Comment: 4 pages, 3 figure

Activated protein C: cost-effective or costly?

The authors offer a commentary on the study by Dhainaut et al. on the cost-effectiveness of activated protein C in severe sepsis. Using data from "real world" conditions, the results of this economic evaluation are consistent with previous analyses, and highlight the need for "real world" investigations of new health technologies in critical care