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Abstract: The effects of high CO2 concentration (10% CO2, 17% O2) on the changes of functional cell wall components (pectic substances, hemicellulose, cellulose, lignin), mechanical properties, content of free soluble sugars (sucrose, glucose, fructose), and respiration activity were studied in harvested white asparagus spears stored at 10 and 20°C, respectively, for up to 7d. Spears stored at 2, 10 and 20°C in air were studied as controls, where the 2°C condition indicated the effects of cold storage. During storage, respiration activity declined only slightly, irrespective of the CO2 and temperature regime. Spears stored at 20°C under both CA and normal air became less stiff and more elastic, however, tissue toughness increased significantly. Changes in toughness were associated primarily with the dynamics of lignin and cellulose, revealing a strong correlation (r 2 =0.81). High CO2 concentration inhibited the synthesis of cellulose and, to some extent, lignin accumulation at 20°C. Additionally, elevated CO2 inhibited the degradation of soluble carbohydrates. In contrast, slightly lower temperatures of 10°C in combination with high CO2 did not have a pronounced effect on changes in structural carbohydrates (lignin, cellulose, hemicellulose and pectins). The effect low temperature (2°C) under normal atmosphere conditions resulted in the inhibition of cell wall changes in asparagus spears. [Copyright &y& Elsevier]

Objective: To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml).Methods: Six pigs underwent repeated chest MDCT using three different CM (iopromide 300, iopromide 370, iomeprol 400). An identical iodine delivery (IDR) rate of 1.5 gI/s and a constant total iodine dose of 300 mg/kg body weight were used. Dynamic CT were acquired at the level of the pulmonary artery, and the ascending and descending aorta. After the time enhancement curves were computed, the pulmonary and aortic peak enhancement, time to peak and plateau time above 300 HU were calculated.Results: Intra-individual peak contrast enhancement was significantly higher for the 300 mgI/ml contrast medium compared with the 370 and 400 mgI/ml media: pulmonary trunk 595 HU vs 516 HU (p = 0.0093) vs 472 HU (p = 0.0005), and aorta 505 HU vs 454 HU (p = 0.0008) vs 439 HU (p = 0.0001), respectively. Comparison of time to peaks showed no significant difference. Plateau times were significantly longer for the 300 mgI/ml than for the 370 and 400 mgI/ml CM at all anatomical sites.Conclusion: Given normalised IDR and total iodine burden, the use of CM with a standard concentration with 300 mg iodine/ml provides improved contrast enhancement compared with highly concentrated CM in the chest. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate differences in change of size and CT value between local recurrences and tumor-free areas after CT-guided radiofrequency ablation (RFA) of hepatic metastases during follow-up by means of dedicated software for automatic evaluation of hepatic lesions. Thirty-two patients with 54 liver metastases from breast or colorectal cancer underwent triphasic contrast-enhanced multidetector-row computed tomography (MDCT) to evaluate hepatic metastatic spread and localization before CT-guided RFA and for follow-up after intervention. Sixteen of these patients (65.1 + or - 10.3 years) with 30 metastases stayed tumor-free (group 1), while the other group (n = 16 with 24 metastases; 62.0 + or - 13.8 years) suffered from local recurrent disease (group 2). Applying an automated software tool (SyngoCT Oncology; Siemens Healthcare, Forchheim, Germany), size parameters (volume, RECIST, WHO) and attenuation were measured within the lesions before, 1 day after, and 28 days after RFA treatment. The natural logarithm (ln) of the quotient of the volume 1 day versus 28 days after RFA treament was computed: lnQ1//28/0(volume). Analogously, ln ratios of RECIST, WHO, and attenuation were computed and statistically evaluated by repeated-measures ANOVA. One lesion in group 2 was excluded from further evaluation due to automated missegmentation. Statistically significant differences between the two groups were observed with respect to initial volume, RECIST, and WHO (p < 0.05). Furthermore, ln ratios corresponding to volume, RECIST, and WHO differed significantly between the two groups. Attenuation evaluations showed no significant differences, but there was a trend toward attenuation assessment for the parameter lnQ28/0(attenuation) (p = 0.0527), showing higher values for group 1 (-0.4 + or - 0.3) compared to group 2 (-0.2 + or - 0.2). In conclusion, hepatic metastases and their zone of coagulation necrosis after RFA differed significantly between tumor-free and local-recurrent ablation zones with respect to the corresponding size parameters. A new parameter (lnQ1//28/0(volume/RECIST/WHO/attenuation)) was introduced, which appears to be of prognostic value at early follow-up CT. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the accuracy of automated nodal quantification in a phantom. MDCT of a phantom with 17 synthetic lymph nodes of different sizes (diameter 6.0-30.0 mm) was performed at varying tube currents, reconstruction kernels and slice thicknesses. RECIST diameter and volume were measured using an automated software tool. Results were compared with the reference diameter and volume by calculating the absolute percentage error (APE). Degree of agreement between software and reference measurements was evaluated by computing corresponding concordance correlation coefficients (CCC). Under varying tube currents the mean APE (CCC) varied between 5.18% and 10.12% (0.95-0.99) for RECIST diameter and between 7.22% and 16.21% (0.94-1.00) for the volume. At different reconstruction kernels the mean APE values ranged between 7.20% and 7.55% (0.99) (RECIST) and between 8.96% and 14.42% (1.00) (volume). With different slice thicknesses the mean APE values differed from 5.81% to 9.20% (0.97-0.99) (RECIST) and from 8.16% to 22.66% (0.99-1.00) (volume). Regarding RECIST criteria and volume, automated evaluation of lymph nodes in a phantom demonstrated a high accuracy under varying MDCT parameters. [ABSTRACT FROM AUTHOR]

As semi-automated measurement would be desirable for lesion quantification and therapy-response control, the purpose of this study was to compare semi-automated measurements with manual assessment of different types of hepatic metastases. Seventy-six patients with known liver metastases were analysed. All of them underwent contrast-enhanced 16-MDCT (16 x 0.75 mm collimation, 120 kV, 0.5 s rotation time, 160 mAs(eff)) for evaluation of follow-up status. On the basis of standard reconstructed 5-mm slices (in 4-mm increments), each lesion was quantified based on RECIST and WHO criteria using a semi-automated software tool (Syngo Oncology) and also manually by an experienced radiologist. Results from the software were compared to manual measurements. Statistical analysis was performed applying the concordance correlation coefficient, and results were represented graphically in Bland-Altman plots. A total of 52 hyperdense, 57 hypodense and 56 heterogeneous metastases were found and correctly measured by the software. All three lesion types revealed a strong correlation agreement between measurement techniques [RECIST diameter: 0.93 (hyperdense), 0.95(hypodense), 0.94 (heterogeneous); WHO area: 0.95, 0.98, 0.93]. Semi-automatic measurement of hyperdense, hypodense and heterogeneous liver metastases showed reliable results on standard axial reconstructions in comparison to manual quantification. [ABSTRACT FROM AUTHOR]

The purpose of this study was to intraindividually evaluate the difference in intraluminal vessel and parenchyma contrast enhancement of two different iodine concentrations in multidetector-row computed tomography (MDCT) of the abdomen. Eighty-three patients underwent baseline and follow-up MDCT-scanning (Somatom Sensation 16; Siemens, Forchheim, Germany) of the abdomen using contrast media containing 370 mg iodine/ml (protocol A; Ultravist 370, Bayer Schering Pharma, Berlin, Germany) and 300 mg iodine/ml (protocol B; Ultravist 300). The total iodine load (37 g iodine) and the iodine delivery rate (1.29 g iodine/s) were identical for both protocols. Contrast enhancement in the portal venous phase was measured in the abdominal aorta, inferior vena cava, portal vein, liver, spleen, pancreas and kidney. Mean attenuation values were compared using paired t-test. Intraindividual comparison revealed no statistically significant differences of the mean attenuation values between protocols A and B for all anatomic sites: abdominal aorta, inferior vena cava, portal vein, liver, spleen, pancreas and kidney (all P > 0.05). Given an injection protocol with constant total iodine load and constant iodine delivery rate, the iodine concentration of contrast media does not significantly influence abdominal contrast enhancement in the portal venous phase. [ABSTRACT FROM AUTHOR]

In a German vineyard (PRO) between 10 and 13 June 2004, the incidence of grapevine downy mildew ( Plasmopara viticola) increased abruptly from 0 to 99%. Infected vines bore on average between 45 and 60 lesions each, corresponding to about 220 000 lesions ha−1 in a non-aggregated distribution. A second vineyard (FUT), approximately 50 m distant from PRO, had been inoculated 3 weeks before the abrupt increase in incidence of disease in PRO. Using microsatellites to ascertain the sources of inoculum and likelihood and extent of interplot spread from FUT to PRO, 555 samples were collected and 20 unique genotypes were identified, of which one caused 80% of the sampled lesions in both vineyards. Three genotypes responsible for 95% of the lesions in FUT and PRO were identified as the genotypes originally established through earlier inoculations in FUT. This is the first report of definitive and quantitative evidence of sporangial migration up to 130 m in a single infection event. The utility of molecular tools to address practical epidemiological issues in this pathosystem is illustrated. The results of this study provide an example of how P. viticola was able to rapidly colonize European vineyards after the pathogen was introduced from North America in 1878. [ABSTRACT FROM AUTHOR]

Abstract: Fruit quality of pepino (Solanum muricatum Ait.) at two ripening stages (mature and ripe) was evaluated under different controlled atmosphere storage conditions (CA) at 5°C and 10°C for up to 21 days. The effect of continuous or varying CA treatments on changes in chroma and pigments was depending on the physiological fruit age. In addition, the cell wall carbohydrates were affected by fruit maturation. In mature fruits, the content of insoluble pectin decreased, while the increase in water-soluble pectin was tendentiously more suppressed by the continuous and varying CA treatments after 21 days of storage, and resulted in a higher retention of fruit firmness. Changes of water-soluble pectin in ripe fruits were inhibited by the CA conditions during storage. Mono- and disaccharides were hardly not affected by CA treatments. Therefore, for shipping purposes and subsequent market distribution, the applied CA treatments used here are suitable for maintaining the quality of mature pepino fruits. However, ripe pepino fruits should be distributed only to local fresh markets as a ready-to-eat-fruit. [Copyright &y& Elsevier]

The Advanced Technology Solar Telescope (ATST) will perform high-resolution studies of the Sun's magnetic fields needed to understand their role in the fundamental processes responsible for solar variability. The generation of magnetic fields through dynamo processes, the amplification of fields through the interaction with plasma flows, and the destruction of fields remain poorly understood. There is incomplete insight as to what physical mechanisms are responsible for heating the corona, what causes variations in the radiative output of the Sun, and what mechanisms trigger flares and coronal mass ejections. Progress in answering these critical questions requires study of the interaction of the magnetic field and convection with a resolution sufficient to observe scales fundamental to these processes.The 4-m aperture ATST is designed as a unique scientific tool, with excellent angular resolution, a large wavelength range, and low scattered light. With its integrated adaptive optics, the ATST will achieve a spatial resolution nearly 10 times better than any existing solar telescope.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html [ABSTRACT FROM PUBLISHER]

A pathogen-reduction technology (PRT) system using riboflavin and light has been developed for the treatment of platelet concentrates (PC) obtained by either buffy coat preparation (BCPC) or apheresis procedures (APPC). The aim of this study was to evaluate the effects of the treatment process onin vitrocell quality and on riboflavin conversion in PC.BCPC were prepared with the Compomat G4™ from whole blood which had been stored overnight after collection. APPC were obtained using the TRIMA™ apheresis procedure. Both PC products had been stored for 18–24 h prior to PRT treatment. BCPC and APPC were treated with PRT on day 2 and day 1 of shelf-life, respectively. The treated PCs were then maintained for an additional 5 days after the PRT treatment. A panel of cell quality assays and high-performance liquid chromatography (HPLC) analysis were performed.Cell counts and plasma lactate dehydrogenase (LDH) levels during storage indicated that PRT did not induce significant cell lysis. Acceleration of a decrease in glucose and an increase in lactate was observed for treated PCs, but no significant differences were observed between treated BCPC and APPC. The pH of treated samples remained above 7·0, although was lower than that of the control. Platelet morphology of BCPC and APPC was well preserved. P-selectin expression indicated significant platelet activation when compared with control PC (BCPC on day 6: 39% vs. 12%; APPC on day 5: 35% vs. 18%). Both P-selectin expression and microparticle formation were not significantly different between treated BCPC and APPC during storage. The JC-1 assay also displayed no loss of mitochondria integrity during the storage of treated products. Approximately 20% of riboflavin converted into photoproducts, including lumichrome.PRT treatment had an effect on the development of the normal platelet storage lesion at a level which seems tolerable for clinical usage. [ABSTRACT FROM AUTHOR]

The effect of different postharvest treatments (film wrapping in conventional and biodegradable materials, foodtainer, surface coating) were evaluated in respect to their suitability to prevent quality loss of bioactive compounds in highly perishable fruits and vegetables. In lettuce, film packaging did not show any beneficial effects on pectic substances and pigments. However, in pepino dulce fruits the use of foodtainer maintained the β-carotene and chlorophyll contents, whereas Semperfresh coating led to a desired inhibition of pectin degradation. Starch coating and OPP-Coex-film packaging prevented the loss of soluble pectins in radish, whereas glucosinolates were only maintained by film packaging. [ABSTRACT FROM AUTHOR]

Focuses on the imaging of vortices and low frequency noise sources in yttrium barium copper oxide direct current superconducting quantum interference device by low temperature scanning electron microscopy. Local perturbation of noise sources; Electron beam-induced local displacement of vortices.

Inference of magnetic fields from very high spatial, spectral, and temporal resolution polarized images is critical in understanding the physical processes that form and evolve fine scale structures in the solar atmosphere. Studying high spectral resolution data also helps in understanding the limits of lower resolution spectral data. We compare three different methods for calibrating the line-of-sight component of the magnetic field. Each method is tested for varying degrees of spectral resolution on both synthetic line profiles computed for known magnetic fields and real data. The methods evaluated are: (a) the differences in the center of gravity of the right and left circular components for different spectral resolution, (b) conversion of circular polarization, at particular wavelengths, to magnetic fields using model-dependent numerical solutions to the equations of polarized radiative transfer, and (c) the derivative method using the weak field approximation. Each method is applied to very high spatial and spectral resolution circular polarization images of an active region, acquired in the Fe i 5250 Å Zeeman-sensitive spectral line. The images were obtained using the 20 mÅ pass-band tunable filter at NSO/Sacramento Peak Observatory Vacuum Tower Telescope. We find that the center-of-gravity separation offers the best way of inferring the longitudinal magnetic field. [ABSTRACT FROM AUTHOR]

We have used the SPO tower telescope and echelle spectrograph to study differences in the profiles of three Fe i lines, between magnetic network and cells. Ca K slit-jaw pictures were used to identify the network and cell areas, and mean network and cell profiles were computed from digitized spectra for the g = 0 lines λλ4065, 5434, and the g = 1.5 line λ 5233. The profile bisectors show that the wings of all three lines are red-shifted in the network by between 75-200 m s relative to the cell profiles. But the redshift decreases in the line core and becomes less than the standard error of 20 m s near the line core minimum. This disappearance of the redshift at the cores of all 3 lines formed over the height range 250-500 km above τ = 1, argues against a steady downflow at supergranule boundaries. We show that such red-shifted wings and a relatively unshifted core can result if granular convection is suppressed near the network flux tubes, without implying any downflow in the vicinity of these flux tubes. Our results also indicate that searches for large-scale convective velocity patterns should measure shifts of the line core, rather than the line wings which appear to be very sensitive to inhomogeneities in granule structure. [ABSTRACT FROM AUTHOR]

We analyze spectral line profiles obtained from regions of the solar surface exhibiting either an upflow or a downflow on a spatial and temporal scale corresponding to the white-light granulation. The differences between their line bisectors are measured to quantify changes in the asymmetry of the profile resulting from granular motion. The observed bisector differences are compared with differences predicted using conflicting granular models. Models, in which the motion of large, long-lived granules decreases rapidly with increasing height in the photosphere, are compatible with the observed line profile asymmetries. [ABSTRACT FROM AUTHOR]

The center-to-limb variation of the root-mean-square granular contrast at 5520 Å is deduced from a set of high-spatial-resolution filtergrams obtained with the Sacramento Peak Observatory Vacuum Tower Telescope. The rms contrast is observed to decrease monotonically between μ = 1.0 and 0.6, and then increase slightly at μ = 0.4. This result is compared with the results of Edmonds (1962) and with the results of Pravdjuk et al. (1974). [ABSTRACT FROM AUTHOR]

• Red light and UV-C inhibited anthocyanin synthesis in spear tips. • Light responses of PAL and POD activities differed in the apical and basal sections. • PAL was inhibited by red and blue light and accelerated by UV-C. • POD was promoted by UV-C and inhibited by white, red and blue light. • Targeted radiation wavelength might be used to trigger quality related processes. Postharvest quality decay of white asparagus spears is often due to red discoloration of spear tips, caused by enhanced epidermal anthocyanin synthesis and accumulation. Exposure to light of different wavelengths triggers distinct physiological processes in plants leading to changes in pigments (e.g. phenolic compounds) and their associated enzymes, among them e.g. phenylalanine ammonia-lyase [PAL, EC 4.3.1.5] and guaiacol peroxidase [POD, EC 1.11.1.7]). The presented work evaluated the impact of light quality (white, red, blue light and UV-C irradiation) on changes in anthocyanin contents and the dynamics of PAL and POD activities in different morphological spears sections (apical and basal) of harvested white 'Gijnlim' asparagus. After harvest, spears were exposed to weak white, red and blue light (30 μmol m-2 s-1) for 3 h and to UV-C irradiation (254 nm, 1 kJ m-2) for 8 min; untreated spears were used as controls. Untreated and light-treated spears were stored in darkness at 20 °C in water vapour saturated atmosphere for up to 4 d. On days 0, 2 and 4, six spears per treatment were selected, severed into basal and apical segments, and respiration rate, anthocyanin content, and PAL and POD activity determined. Light quality did not influence respiration, but section-specifically mediated changes of anthocyanin contents, and PAL and POD activities. White light triggered anthocyanin synthesis via an associated PAL increase, whereas red light and UV-C irradiation tendentiously resulted in an anthocyanin inhibition or even degradation, coinciding with changes in PAL activity, respectively. Blue light increased anthocyanin content in spear tips to the same extent as for controls. However, also other enzymes might play an important role in the light induced anthocyanin synthesis. In basal segments, PAL and POD activities were higher than in apical segments; however, light treatments affected both enzyme activities differently. In the apical, PAL activity was enhanced by white light and UV-C. In contrast, in the basal segments the different wavelength ranges did not affect PAL except for UV-C also increasing PAL activity. The activity of POD increased in tip sections throughout storage and remained high irrespective of light treatments, except for UV-C, strongly stimulating POD activity. POD was also UV-C stimulated in basal segments, whereas white, blue and red light inhibited its activity for a limited time during storage. Differentiated responses in apical and basal segments indicated distinct physiological activity, signalling chains and availability of resources from primary metabolism. PAL may be a major factor controlling lignification in the basal segments of spears, irrespective of light quality, while POD activity is significantly triggered by mainly UV-C indicating its role as an antioxidant enzyme in the physiological active spear tips. [ABSTRACT FROM AUTHOR]

We used low-temperature scanning electron microscopy (LTSEM) for imaging quantized magnetic flux (vortices) in dc superconducting quantum interference devices (SQUIDs) with approximately 1 μm spatial resolution at temperature T=77 K in a controllable magnetic field up to 20 μT. We demonstrate that LTSEM allows to image the spatial distribution of vortices in a YBa[sub 2]Cu[sub 3]O[sub 7]/SrTiO[sub 3]/YBa[sub 2]Cu[sub 3]O[sub 7] multilayer thin-film structure consisting of a dc SQUID washer with an integrated input coil on top. Simultaneously, we are able to measure the low-frequency noise of the sample under test, which allows to correlate the spatial distribution of vortices with low-frequency noise in the SQUID. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]