CO2/O2 specificity factor of ribulose-1,5-bisphosphate carboxylase/oxygenase in grapevines (Vitis vinifera L.): First in vitro determination and comparison to in vivo estimations

The specificity factor (S) of ribulose-1,5-bisphosphate. carboxylase/oxygenase (Rubisco) defines the relative rates of carboxylation and oxygenation of Ribulose-1,5-bisphosphate (RuBP) catalysed by the enzyme. The determination of S for Rubisco purified from the Vitis vinifera L. cvs Tempranillo and Manto Negro is described here for the first time. Rubisco extraction was made in Bicine buffer with the inclusion of polyethylene glycol (PEG), beta-mereaptoethanol, diethyldithio-carbamic acid (DIECA) and several protease inhibitors. Furthermore, in the same cultivars, the apparent in vivo specificity factor for Rubisco (S*), was obtained from gas exchange and chlorophyll fluorescence measurements. For both cultivars the values of S were close to 100 at 25 degreesC. However, in mature leaves, S* was about 67 for Manto Negro and 55 or 77 for Tempranillo, depending on leaf age. Leaves of plants under drought showed even lower values. These discrepancies between S and S* are ascribed to equating CO2 in the sub-stomatal cavity with CO2 at the Rubisco catalytic site in the chloroplast. However, S* values from young developing leaves were very close to S for both cultivars. It is concluded that estimations of S* based on gas exchange and chlorophyll fluorescence data are reliable only in thin, young and non-stressed leaves.

Predesign study for a modern 4-bladed rotor for the NASA rotor systems research aircraft

Trade-off study results and the rationale for the final selection of an existing modern four-bladed rotor system that can be adapted for installation on the Rotor Systems Research Aircraft (RSRA) are reported. The results of the detailed integration studies, parameter change studies, and instrumentation studies and the recommended plan for development and qualification of the rotor system is also given. Its parameter variants, integration on the RSRA, and support of ground and flight test programs are also discussed

Molecular random tilings as glasses

We have recently shown [Blunt et al., Science 322, 1077 (2008)] that p-terphenyl-3,5,3',5'-tetracarboxylic acid adsorbed on graphite self-assembles into a two-dimensional rhombus random tiling. This tiling is close to ideal, displaying long range correlations punctuated by sparse localised tiling defects. In this paper we explore the analogy between dynamic arrest in this type of random tilings and that of structural glasses. We show that the structural relaxation of these systems is via the propagation--reaction of tiling defects, giving rise to dynamic heterogeneity. We study the scaling properties of the dynamics, and discuss connections with kinetically constrained models of glasses.Comment: 5 pages, 5 figure

Evaluating the cost-effectiveness of tiotropium versus salmeterol in the treatment of chronic obstructive pulmonary disease

Shalini Naik, Khalid M Kamal, Patricia A Keys, Thomas J MatteiDuquesne University School of Pharmacy, Pittsburgh, PA, USAObjective: To assess the cost-effectiveness of 3 treatments (tiotropium, salmeterol, and no treatment) in patients with moderate chronic obstructive pulmonary disease (COPD).Methods: A Markov model with a time horizon of 1 year was developed. A hypothetical cohort of 100,000 subjects with moderate COPD with mean age of 65 years, smoking history of 50 pack-years, and disease duration of 9.5 years were included in the model. The efficacy and withdrawal data were taken from published randomized clinical trials. The effectiveness measure was exacerbations avoided per patient per year. Incremental cost-effectiveness ratio (ICER) was calculated as additional cost per patient to prevent 1 exacerbation, compared with the next most expensive option. A payer’s perspective was used and only direct costs were included in the study. Sensitivity analyses were conducted to test the robustness of the baseline estimates and study assumptions.Results: The mean annual costs for the no treatment, salmeterol, and tiotropium groups were $392.1,$1268.7, and $1408.6, respectively. The ICER of tiotropium compared with no treatment was$1817.36 per exacerbation avoided, while the ICER of salmeterol compared with no treatment was $2454.48 per exacerbation avoided. Thus, in patients with moderate COPD, tiotropium is more cost-effective than salmeterol and no treatment.Keywords: cost-effectiveness, chronic obstructive pulmonary disease, markov model, tiotropium, salmetero

Performance of an Earthdam and Cut-off Through Deep Alluvium

The main dam at the Bighorn development consists of a zoned earthfill embankment with a concrete cut-off wall constructed through the river alluvium by the slurry trench technique. Upon first filling of the reservoir in 1972, erratic drops in piezometric heads in the alluvium upstream of the cut-off and significant downstream leakage prompted the construction of a weight berm at the downstream toe and implementation of a program of regular monitoring of all piezometers and seepage measuring facilities. Concern for the integrity of the structure was not allayed until completion of a dam safety evaluation in 1984. The paper summarizes the design and construction aspects of the main dam and concrete cut-off, documents the results of monitoring records of seepage and piezometric heads since reservoir filling and assesses the extent of reservoir siltation. Records and inspections demonstrate satisfactory performance of the structure

Infrared measurements in the spring 1987 ozone hole

Solar spectra were recorded from Arrival Heights (McMurdo), Antartica, with a FTIR system during the austral spring of 1987. Spectra were recorded on 22 days from September 13 through October 28. The instrument was setup with 2 detectors for simultaneous operation in 2 wavelength regions. Several stratospheric gases have measurable absorptions in these regions including HCl, HNO3, O3, ClONO2, and NO2. The system is equipped with an automatic solar tracking system and records data on tape cartridges. A portable personal computer allows Fourier transforming and initial processing of some of the data. The HNO3 gas column amount shows large variations, but no apparent correlation with stratospheric temperature. The HCl column shows a steady increase from 0.9 x 10 to the 15th power molecules/sq.cm. on September 13 to 1.5 x 10 to the 15th power on October 6. McMurdo moved out of the polar vortex for a few days, and the HCl column jumped to 2.9 x 10 to the 15th power by October 11. Although McMurdo moved back under the vortex, the HCl continued to increase, reaching 3.4 x 10 to the 15th power at the end of the period