407 research outputs found
Internal polarized gas targets: systematic studies on intensity and correlated effects
No full textThe work carried out during the PhD was dedicated to the study of high-density polarized
gas targets used in high-energy physics. The thesis is related to the PAX experiment,
which aims to produce a beam of polarized anti-protons, by means of spin-filtering with a
polarized atomic target. In order to obtain the densities required by high-energy particle
physic, gaseous targets are a combination of an Atomic Beam Source and a storage cell.
The possibility to improve the various components of the ABS and the storage cell has been
evaluated, through dedicated systematic studies, using the facilities available in “Spinlab”
of Universit´a di Ferrara.
The attenuation of a collimated beam passing through the rest gas of a vacuum system
has been studied; different nozzle geometries have been tested (comparing the measured
data with the data calculated by simulation programs); design and tests of an new kind
of injection tube with internal fins (with the aim of decreasing the conductance of the
storage cell without diminishing the acceptance and thus to increase the integrated target
thickness).
Estimation of the attenuation coefficients and total cross sections have been derived from
the measurements of the attenuation of a hydrogen or deuterium beam. This quantities
are important for projecting new ABS and to improve the existing ones. A favorable
nozzle geometry (called “trumpet”) that increases the beam intensity has been derived
from simulations and experimental tests. Tests on the injection tubes with fins did not
give positive results when applied to the PAX storage cell geometry; however a azimuthal
motion of the atoms of a focused beam emerged from the measurements, a motion that
until now has been completely neglected
Incontri di Fisica delle Alte Energie - IFAE 2012 - Il Nuovo Cimento C Year 2013 - Issue 1 - January-February - Year 2013 Vol 036 -
No full textIncontri di Fisica delle Alte Energie 201
Estimation of cotyledon isoflavone abundance by a grey luminance-based model in variously hilum-coloured soybean varieties
No full textBACKGROUND: The nutraceutical uses of soybean (Glycine max L. Merr.) have received increasing attention in recent years, due to the therapeutic effects of high seed isoflavone concentrations against heart disease, cancer and menopausal symptoms.
RESULTS: We found a close correlation between seed isoflavone abundance and hilum colour in a set of 17 contrasting soybean varieties. Image analysis of the hilum greylevel pattern allowed us to identify a power model which approximates total cotyledon isoflavone concentrations (TCIC) at 65–71% by the normalised modal grey level. Higher TCIC levels were assigned to darker hilum varieties and vice versa within a variety-dependent response. Optimisation of the algorithm required correction for a few specific varieties falling in the intermediate 1.1–1.5 mg/g TCIC range, which were over-estimated by the model, perhaps due to variations in hilar optical properties related to the geometric features of both hilum and seed.
CONCLUSION: In view of its easy, low-cost detection, seed hilum colour is a useful phenotypic trait in soybean for rapid evaluation of isoflavone abundance in food uses and for improving specific nutraceutical breeding programmes
Accumulation and effects of perfluoroalkyl substances in three hydroponically grown Salix L. species
No full textThe potential of young rooted cuttings of three Salix L. species plants to accumulate a mixture of eleven perfluoroalkyl substances (PFASs), in particular, perfluoroalkyl acids (PFAAs), from the nutrient solution and their effects on plant growth and photosynthesis were assessed in an 8-day experiment. The growth rate of the willow plants exposed to the PFAA mixture was not much affected except for S. triandra. Regarding photosynthesis, the gas exchange parameters were affected more than those related to chlorophyll fluorescence, with significant increase of the net CO2 assimilation rate and parameters related to stomatal conductance. A decreasing trend in the PFAA concentration in leaves with increasing carbon chain length was observed, whereas long-chain PFAAs showed higher concentrations in roots. Accordingly, the foliage to root concentration factor highlighted that PFAAs with shorter carbon chain length (C ≤ 7) translocated and accumulated relatively more in leaves compared to roots. Removal efficiency of individual PFAAs for leaves and roots were comparatively higher with S. eleagnos and S. purpurea than S. triandra, with mean removal values at the whole plant level ranging around 10% of the amount initially spiked, suggesting their potential for phytoremediation of PFASs
Intensità di colorazione dell’ilo quale indicatore fenotipico del contenuto di isoflavoni nel seme di soia
No full textIntraspecific variability for soybean cotyledon isoflavones in different cropping and soil condidtions.
No full textCotyledon isoflavones, such as genistein, daidzein and their glucosyl and malonyl forms, were detected by HPLC-UV in 18 0- and 1-maturity class soybean varieties, cultivated under organic and conventional farming (3 years) and various soils (2 years) at Legnaro, NE Italy. Among varieties, the overall coefficient of variation for total cotyledon isoflavone concentration (TCIC) was 22%, and cluster analysis revealed three variety groups. Group L had 1.22 mg g(-1) TCIC (low) and 40.3% proteins: group H, mainly including black-hilum varieties, 2.10 mg g(-1) (high) and 39.2%, and group 11.77 mg g(-1) (intermediate) and 39.4%. Isoflavone profiles were similar in groups L and H (55% genistein and 45% daidzein aglycone equivalents), whereas group I had increased genistein (61%), which is recognised to have lower intestinal bioavailability (nutraceutics). Under organic management, a 2% protein increase (all groups) was associated with a 5-15% variety-dependent decrease - in groups H and I - and stable TCIC in group L Isoflavone accumulation was positively affected by rainfall and limited daily range temperature regimes during pod filling, and hail damage (year 2005). In the Nikir variety (maturity class 1), grown in four lysimeter soils, TCIC was negatively correlated with soil C/N ratio, partially explaining the worse TCIC in organic cultivation. Based on this relationship, TCIC followed the order clay-loam > silty-loam > organic > sandy, with a 64% difference between extremes
Intraspecific variability for soybean cotyledon isoflavones under different cropping and soil conditions.
No full textCotyledon isoflavones, such as genistein, daidzein and their glucosyl and malonyl forms, were detected by HPLC–UV in 18 0- and 1-maturity class soybean varieties, cultivated under organic and conventional farming (3 years) and various soils (2 years) at Legnaro, NE Italy.
Among varieties, the overall coefficient of variation for total cotyledon isoflavone concentration (TCIC) was 22%, and cluster analysis revealed three variety groups. Group L had 1.22mgg−1 TCIC (low) and 40.3% proteins; group H, mainly including black-hilum varieties, 2.10mgg−1 (high) and 39.2%, and group I 1.77mgg−1 (intermediate) and 39.4%. Isoflavone profiles were similar in groups L and H (55% genistein and 45% daidzein aglycone equivalents), whereas group I had increased genistein (61%), which is recognised to have lower intestinal bioavailability (nutraceutics).
Under organic management, a 2% protein increase (all groups) was associated with a 5–15% variety-dependent decrease – in groups H and I – and stable TCIC in group L. Isoflavone accumulation was positively affected by rainfall and limited daily range temperature regimes during pod filling, and hail damage (year 2005).
In the Nikir variety (maturity class 1), grown in four lysimeter soils, TCIC was negatively correlated with soil C/N ratio, partially explaining the worse TCIC in organic cultivation. Based on this relationship, TCIC followed the order clay-loam > silty-loam >organic > sandy, with a 64% difference between extremes
Nitrogen fertilization and irrigation compulsory effect on soybean (Glycine max L. Merr) isoflavone
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