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We examine the capability of the Global Modeling Initiative (GMI) chemistry and transport model to reproduce global mid-tropospheric (618 hPa) ozone–carbon monoxide (O3–CO) correlations determined by the measurements from the Tropospheric Emission Spectrometer (TES) aboard NASA's Aura satellite during boreal summer (July–August). The model is driven by three meteorological data sets (finite-volume General Circulation Model (fvGCM) with sea surface temperature for 1995, Goddard Earth Observing System Data Assimilation System Version 4 (GEOS-4 DAS) for 2005, and Modern-Era Retrospective Analysis for Research and Applications (MERRA) for 2005), allowing us to examine the sensitivity of model O3–CO correlations to input meteorological data. Model simulations of radionuclide tracers (222Rn, 210Pb, and 7Be) are used to illustrate the differences in transport-related processes among the meteorological data sets. Simulated O3 values are evaluated with climatological profiles from ozonesonde measurements and satellite tropospheric O3 columns. Despite the fact that the three simulations show significantly different global and regional distributions of O3 and CO concentrations, they show similar patterns of O3–CO correlations on a global scale. All model simulations sampled along the TES orbit track capture the observed positive O3–CO correlations in the Northern Hemisphere midlatitude continental outflow and the Southern Hemisphere subtropics. While all simulations show strong negative correlations over the Tibetan Plateau, northern Africa, the subtropical eastern North Pacific, and the Caribbean, TES O3 and CO concentrations at 618 hPa only show weak negative correlations over much narrower areas (i.e., the Tibetan Plateau and northern Africa). Discrepancies in regional O3–CO correlation patterns in the three simulations may be attributed to differences in convective transport, stratospheric influence, and subsidence, among other processes. To understand how various emissions drive global O3–CO correlation patterns, we examine the sensitivity of GMI/MERRA model-calculated O3 and CO concentrations and their correlations to emission types (fossil fuel, biomass burning, biogenic, and lightning NOx emissions). Fossil fuel and biomass burning emissions are mainly responsible for the strong positive O3–CO correlations over continental outflow regions in both hemispheres. Biogenic emissions have a relatively smaller impact on O3–CO correlations than other emissions but are largely responsible for the negative correlations over the tropical eastern Pacific, reflecting the fact that O3 is consumed and CO generated during the atmospheric oxidation process of isoprene under low-NOx conditions. We find that lightning NOx emissions degrade both positive correlations at mid- and high latitudes and negative correlations in the tropics because ozone production downwind of lightning NOx emissions is not directly related to the emission and transport of CO. Our study concludes that O3–CO correlations may be used effectively to constrain the sources of regional tropospheric O3 in global 3-D models, especially for those regions where convective transport of pollution plays an important role.

Spinal burst fractures account for about 15% of spinal injuries and, because of their predominance in the younger population, there are large associated social and healthcare costs. Although several experimental studies have investigated the burst fracture process, little work has been undertaken using computational methods. The aim of this study was to develop a finite element model of the fracture process and, in combination with experimental data, gain a better understanding of the fracture event and mechanism of injury. Experimental tests were undertaken to simulate the burst fracture process in a bovine spine model. After impact, each specimen was dissected and the severity of fracture assessed. Two of the specimens tested at the highest impact rate were also dynamically filmed during the impact. A finite element model, based on CT data of an experimental specimen, was constructed and appropriate high strain rate material properties assigned to each component. Dynamic validation was undertaken by comparison with high-speed video data of an experimental impact. The model was used to determine the mechanism of fracture and the postfracture impact of the bony fragment onto the spinal cord. The dissection of the experimental specimens showed burst fractures of increasing severity with increasing impact energy. The finite element model demonstrated that a high tensile strain region was generated in the posterior of the vertebral body due to the interaction of the articular processes. The region of highest strain corresponded well with the experimental specimens. A second simulation was used to analyse the fragment projection into the spinal canal following fracture. The results showed that the posterior longitudinal ligament became stretched and at higher energies the spinal cord and the dura mater were compressed by the fragment. These structures deformed to a maximum level before forcing the fragment back towards the vertebral body. The final position of the fragment did not therefore represent the maximum dynamic canal occlusion.

Advanced design requirements have dictated a need for the mechanical properties of materials at high strain rates. Mechanical testing for these data poses a significant problem for experimentalists. High-speed testing machines have a limited capability at rates approaching 102/s. The split Hopkinson pressure bar is the most reliable alternative for rates approaching 104/s. Plate impact experiments are capable of generating strain rates of 108/s and higher. The Taylor impact test occupies a place of particular importance by providing data at strain rates on the order of 104/s–105/s. The issue at present is extracting the data. This paper provides a method for obtaining dynamic strength model material constants from a single Taylor impact test. A polynomial response surface is used to describe the volume difference (error) between the deformed specimen from the Taylor test and the results of a computer simulation. The volume difference can be minimized using an optimizer, with the result being an optimum set of material constants. This method was applied to the modified Johnson-Cook model for OFHC copper. Starting from a nominal set of material constants, the iterative process improved the relative volume difference from 23.1 percent to 4.5 percent. Other starting points were used that yielded similar results. The material constants were validated by comparing numerical results with Taylor tests of cylinders having varying aspect ratios, calibers and impact velocities.

Bean common mosaic necrosis virus (BCMNV) was isolated from Centrosema pubescens, Crotalaria incana, Lablab purpureus, Phaseolus lunatus, Senna bicapsularis, S. sophera, Vigna vexillata and an unidentified Crotalaria species growing in Uganda. Thirteen distinct isolates were characterized using symptoms, pathogenicity in differential bean cultivars, serology, immunosorbent electron microscopy, and seed and aphid transmission. Some isolates conformed with the characteristics of previously described strains of BCMNV but others showed novel properties. All isolates reinfected the natural host from which they were obtained. The origin and ecological significance of these isolates is discussed.

The application of laser irradiation to etch dental enamel in preparation for direct bonding of orthodontic appliances has been studied. Forty extracted human teeth were divided into four groups of 10 teeth. Within each group, five teeth were subjected to a 30 sec acid etch of the buccal enamel surface; the other five in each group were etched with a laser. Four power settings on the laser etching unit were used: 80mJ, 1W, 2W and 3W. After etching, brackets were adhered to the prepared buccal enamel surfaces with composite resin. Shear bond strength was tested 7 days later. The findings showed that an acceptable shear bond strength, viz.or = 0.6 kg/mm, could be achieved at laser power settings of 1 to 3W but not at the lowest setting (80 mJ). However, the mean shear bond strengths obtained with laser treatment of the enamel at 80mJ, 1W and 2W were lower (p0.01 or 0.001) than that achieved with acid etching.

The heat produced at the dentinal pulpal wall opposite the irradiation site was measured during etching of dental enamel with an Nd:YAG laser in preparation for direct bonding of orthodontic appliances. Forty extracted human teeth were randomly divided into four groups of 10 teeth. Within each group, the buccal surfaces of 5 teeth and the lingual surfaces of the other 5 teeth were laser treated for 12 sec. Irradiation was performed with a commercial Nd:YAG laser at the power settings of 80mJ, 1W, 2W and 3W. Prior to irradiation, an occlusal access preparation was made into the pulp in order to facilitate the placement of a thermocouple for measurement of temperature changes at the dentinal pulpal wall opposite the irradiation site. The thermocouple was held against the dentinal pulpal wall and the resulting temperature changes were recorded. Heating effects at the dentinal pulpal wall on both buccal and lingual surfaces showed an increase in heat as a function of the increase in power output from the laser unit (p0.01). The temperatures measured at power levels 1-3W appeared to be of sufficient magnitude to cause at least localized pulpal inflammation and possible irreversible damage to the pulp tissue immediately opposite the site of laser irradiation.

Repeated thrombin treatment of washed platelets prepared from rabbits can decrease the serotonin content of the platelets by about 80%. When these platelets are deaggregated they reaccumulate serotonin but their storage capacity for serotonin is reduced by about 60%. If thrombin-pretreated platelets are allowed to equilibrate with a high concentration of serotonin (123 mu M), they release a smaller percentage of their total serotonin upon further thrombin treatment, in comparison with the percentage of serotonin released from control platelets equilibrated with the same concentration of serotonin calculations indicate that in thrombin-treated platelets reequilibrated with serotonin, two-thirds of the serotonin is in the granule compartment and one-third is in the extragranular compartment, presumably the cytoplasm. Analysis of the exchange of serotonin between the suspending fluid and the platelets showed that thrombin treatment does not alter the transport rate of serotonin across the platelet membrane and does not cause increased diffusion of serotonin from the platelets into the suspending fluid. The primary reason for the reduced serotonin accumulation by the thrombin-treated platelets appears to be loss of amine storage granules or of the storage capacity within the granules.

We used a laboratory model of gouty synovitis giving quantitative dose-dependent results with urate injection intrasynovially into the knee joint of dogs. We found that when precautions were taken to prevent any possible endotoxin contamination of the urate crystals, they became significantly less active. Endotoxin by itself, from Escherichia coli, was very potent in causing pain and leukocytic infiltration into the knee joint. Such endotoxin was readily and firmly adsorbed onto urate crystals. A small dose of urate crystals that caused no pain by itself became very painful when the crystals were allowed to adsorb endotoxin in vitro. When this same small non-painful dose of urate crystals was given into the joint, and the dog also received endotoxin by the oral route, signs of pain arose very clearly. It is known that gouty patients even when in remission may have crystals of sodium urate in the synovial fluid. It would therefore appear possible that if such urate crystals were to adsorb an endotoxin passing from the gastrointestinal tract into the plasma, thence into the synovial space, the patients may develop an attack of gout.

A significant portion of the demand for industrial process heat can be met with solar energy. Whether this energy source is widely used will depend not only on its economic attractiveness, but also on the ease with which solar thermal systems interface with the remainder of the industrial plant. Foster Wheeler has recently designed solar thermal systems to supply hot water and process steam to industry and has nearly completed the construction of one of these. Drawing on this experience, this paper discusses selection of solar technologies that can best satisfy the user’s energy requirements and minimize interfacing problems.

Solar thermal systems capable of providing process heat to the industries that make up the Food and Kindred Products Group are now commercially available. Whether or not they will be adopted by these industries will depend not only upon further reductions in capital costs, but also upon the costs and availability of alternative fossil fuels, the operating and maintenance costs of solar thermal systems, and tax incentives.

Acrosin and acrosomal hyaluronidase were inhibited by tetradecyl sodium sulphate (TDSS) in vitro at concentrations of less than 10(-4) M. TDSS prevented the removal in vitro of the cumulus oophorus by testicular hyaluronidase and the zona pellucida by acrosin. TDSS had a contraceptive effect in rabbits when administered intravaginally before coitus or released at levels of 1-3 micrograms/day from intrauterine silicone rubber devices.

Within multicompartment cellular systems in the steady state the distrubution of tracer as a function of time is described by sums of exponentials. A design for data collection and analysis is set forward to deal with the problems of lumping and ill-conditioning inherent in such a mathematical description. This design requires the provision of multiple responses and can be analyzed by a Bayesian multivariate technique. Although only one response may be capable of completely characterizing the system, there is much to be gained from additional responses in terms of precision in parameter estimation. A time series is used to account for autocorrelated error in the responses. The design is compared to other least squares approaches and is demonstrated in an investigation of the transport and storage of serotonin in blood platelets. The kinetic parameters describing serotinin movement are estimated and their joint confidnece regions plotted.

Subcellular changes in 12 dura mater cardiac valves (in the mitral or aortic position) surgically removed after 23 to 108 months of implantation owing to calcification, rupture, or endocarditis show signs of a remodeling process. Significant morphologic changes in the connective tissue fiber matrices and cell populations were noted in the recovered valvular leaflets. Macrophages were found within electronlucent (cleared-out) areas, and they seemed to play an essential role in the remodeling process by ingesting and digesting selected connective tissue components. Fibroblasts found within these "rebuilding" areas in the dura mater tissue possessed small cytoplasmic vesicles (65 nm in diameter) being extruded from the cell. Evidence of early collagen formation was also found in association with both peripheral filaments and peripheral condensations, as well as within the connective tissue matrices surrounding the cellular elements, where electron dense amorphous material was observed. In conclusion, the long-term durability of dura mater bioprosthetic cardiac valves may be directly related to (1) glycerin stabilization and preservation of the collagen fibers, (2) the viability of the fibroblasts and macrophages within the implanted valves, and (3) the unique morphology and fine structure of the double-layered dura mater encephali. We hypothesize that the fibroblasts or myofibroblast-like cells found within the implanted leaflets, no matter what their origin, are capable of giving form and organization to the early developing connective tissue.

This investigation used light microscopy and transmission and scanning electron microscopy to study native human and bovine parietal pericardium, glutaraldehyde-fixed bovine pericardial patch-grafts, and bovine pericardial cusps of unimplanted Incor or Puig - Zerbini heart valves. The primary objective was to obtain a data base for the future evaluation of postimplantation structural alteration in this valve and in other cardiac valvular bioprostheses constructed of pericardium. The mesothelial cell layer in normal pericardium was best preserved in the bovine tissue. In both bovine patch-grafts and Puig - Zerbini valvular cusps, the serosal surface usually was completely devoid of mesothelial cells and revealed an underlying, finely fibrillar basal lamina. The fibrosa varied in thickness and organization, both within and between the two species, but similar nervous, vascular, and connective tissue components were observed in each. The epipericardial surface was smoother, had fewer elastic fibers, and possessed more surface cells in the human tissue than in the bovine tissue. No evidence of significant tissue degeneration or remodeling was noted in either the stored patch-grafts or heart valves when compared with control bovine and human pericardial tissue layers.

1. Temperature, oxygen consumption, electromyographic activity, plasma non-esterified fatty acids and blood sugar were estimated in conscious unrestrained young chickens under conditions of thermoneutrality (31 degrees C) and below thermoneutrality (16 degrees C). In some chickens carotid arterial pressure was also recorded.2. At thermoneutrality, alpha-methylnoradrenaline lowered temperature and oxygen consumption in intact or chronically vagotomized chicks. alpha-Methylnoradrenaline was ineffective on temperature in chicks with transection of the brain-stem posterior to the hypothalamus but anterior to the respiratory centre. Hypothermia due to alpha-methylnoradrenaline was associated with a significant reduction of plasma non-esterified fatty acids but blood sugar was not significantly altered. Lowering of temperature by alpha-methylnoradrenaline occurred despite vasoconstriction which would hinder heat loss.3. Temperature and oxygen consumption were reduced by alpha-methylnoradrenaline in chronically thyroidectomized chicks to the same extent as in intact chicks but recovery did not occur unless the chicks were taken from the metabolism chamber and warmed artificially. In contrast, chronically thyroidectomized chicks given replacement thyroxine were relatively resistant to alpha-methylnoradrenaline.4. Oxygen consumption of tissue slices from different parts of the chick's brain, including the diencephalon, was not altered by alpha-methylnoradrenaline over an extensive dose range. The effects of alpha-methylnoradrenaline on temperature and oxygen consumption in intact chickens were unlikely, therefore, to be due to depressed metabolism of neurones.5. In an environment below thermoneutrality (16 degrees C) temperature was considerably reduced and carotid arterial pressure fell 40-50 mmHg. In contrast, electromyographic activity, oxygen consumption and plasma non-esterified fatty acids were markedly raised whereas blood sugar was insignificantly elevated.6. In experiments at 16 degrees C, alpha-methylnoradrenaline markedly reduced oxygen consumption although values were still higher than those at thermoneutrality. Temperature fell further, but whereas the reductions in oxygen consumption and temperature were long-lasting, electromyographic activity (shivering) was only transiently diminished. Plasma non-esterified fatty acids were reduced after alpha-methylnoradrenaline but not significantly so; blood sugar was not significantly altered. The time-course for recovery of oxygen consumption following a-methylnoradrenaline paralleled recovery from its blood pressure effects but the effect on oxygen consumption was not a consequence of the blood pressure changes. The effects of a-methylnoradrenaline on temperature, oxygen consumption and electromyographic activity were similar to those of another central depressant, pentobarbitone.

SUMMARY Within multicompartment cellular systems in the steady state the distribution of tracer as a function of time is described by sums of exponentials. A design for data collection and analysis is set forward to deal with the problems of lumping and ill-conditioning inherent in such a mathematical description. This design requires the provision of multiple responses and can be analyzed by a Bayesian multivariate technique. Although only one response may be capable of completely characterizing the system, there is much to be gainied from additional responses in terms of precision in parameter estimation. A time series is used to account for autocorrelated error in the responses. The design is compared to other least squares approaches and is demonstrated in an investigation of the transport and storage of serotonin in blood platelets. The kinetic parameters describing serotonin movement are estimated and their joint confidence regions plotted.