20,026 research outputs found
Ecology of A.carbonarius and ochratoxin A production in vine fruits and control in the production chain
No full textThis study examined black aspergilli, especially A. carbonarius and A. niger and
ochratoxin A (OTA) contamination of grapes, during drying and industrial processing
of dried vine fruits. This was complemented by studies on potential control using
preservatives and physical factors such as modified atmospheres. Fungal population
kinetics were determined in relation to grapes at harvest, and during drying at three
different altitudes (sea level: 0-200 m; medium level: 250-500 m; high level: >500 m)
in two seasons. At pre-harvest, A. niger aggregate species were the predominant
fungal species while A. carbonarius was occasionally isolated, in both years studied.
Both altitude and bunch position affected black aspergilli population dynamics.
Overall, they were increased during drying. However, both black aspergilli groups
were mostly isolated, at low and medium altitudes (<500 m). OTA contamination
was influenced by bunch position, although altitude did not significantly influenced
amounts. The fungal biodiversity was decreased during sun-drying of sultanas. The
widest diversity of species occurred at the sea level. However, A. niger aggregate,
were dominant during drying. Time of drying and altitude significantly influenced
fungal loads of black aspergilli. In contrast, OTA production (ca 0.001 - 0.0025 μg g
-
1
) was not significantly influenced by altitude and drying time. Shannon Index of
Biodiversity (H), for pre-harvest and pos-harvest studies, was determined for the first
time.
A. niger aggregate (ca 5.0 Log10 CFUs g
-1
) was predominant during industrial
processing, while A. carbonarius was only isolated at low levels (1.5-2.0 Log10 CFUs
g
-1
). Heat treatment (up to 90
o
C) appeared to be the key-procedure for the
elimination of fungal populations. In the contrary, SO2 treatment did not statistically
alter fungal population dynamics. OTA contamination was not significantly affected
by industrial processing.
In vitro studies conducted on both White Grape Juice Medium (WGJM) and in
sultanas with strains of A. carbonarius originated from Cretan sultanas and compared with a strain isolated from Italian wine grapes. They examined the impact of sodium
metabisulphite (NaMBS), elevated CO2 (up to 50%) concentrations and aw levels, on
black aspergilli spore germination, growth and OTA production. Moreover, fungal
interactions in vitro and in situ were also investigated.
In general, spore germination occurred over a wide range of sodium metabisulphite
concentrations, although germ tube extension was significantly controlled. At ≥ 750
mg L
-1
NaMBS, no spore germination was observed while both mycelial growth and
OTA production were completely inhibited. Medium concentrations of NaMBS (≤
250 mg L
-1
) enabled optimum spore germination, growth and OTA production (x
0.965 aw). The efficacy of controlled atmospheres x aw showed that there was very
little inhibitory effect on spore germination. However, both germ tube extension and
fungal growth were inhibited by 50% CO2. After 10 days, growth was not as
effectively controlled. Aw had a bigger effect on OTA production than modified
atmospheres. In situ experiments on sultanas confirmed these results. Competition
and dominance of A. carbonarius over other fungal species showed that aw and
temperature influenced Indices of Dominance and OTA production. In vitro and in
situ, OTA production by A. carbonarius was significantly influenced by the fungal
competitor used
Endothelial intercellular adhesion molecule-1 expression is suppressed in human malignancies: the role of angiogenic factors
No full text
General Helices of AW(k)-Type in the Lie Group
No full textWe study curves of AW(k)-type in the Lie group G with a bi-invariant metric. Also, we characterize general helices in terms of AW(k)-type curve in the Lie group G
The Aw–Rascle Traffic Model: Enskog-Type Kinetic Derivation and Generalisations
No full textWe study the derivation of second order macroscopic traffic models from kinetic descriptions. In particular, we recover the celebrated Aw–Rascle model as the hydrodynamic limit of an Enskog-type kinetic equation out of a precise characterisation of the microscopic binary interactions among the vehicles. Unlike other derivations available in the literature, our approach unveils the multiscale physics behind the Aw–Rascle model. This further allows us to generalise it to a new class of second order macroscopic models complying with the Aw–Rascle consistency condition, namely the fact that no wave should travel faster than the mean traffic flow
Synthesis and Characterization of Biobased Polyesters with Tunable T-g by ROCOP of Beta-Elemene Oxides and Phthalic Anhydride
No full textThe use of terpene-based oxides derived from beta-elemene is reported in the context of new functional semiaromatic polyester development. In particular, poly(beta-elemene monoxide-alt-phthalic anhydride) featuring two double bonds per repeating unit having distinct reactivity is conveniently prepared by iron- and aluminum-mediated ring-opening polymerization (ROCOP). Sequential and selective transformation of each of these double bonds is addressed by epoxidation allowing one to precisely manipulate the degree and nature of the functionality in the polymer backbone while modulating the T-g from 68 to 121 degrees C. Direct access to cross-linked polyesters is demonstrated by ROCOP of bifunctional beta-elemene dioxide and phthalic anhydride furnishing a material with a Tg of 125 degrees C
[aw-faw] (offal)
No full textoffalThe fore-castle of the ANDERSON- It was full to see; And the 'aw-faw' from the boilers- It was nearly to your knees; The 'G-D gubby-bucket, It was always full, you know, And the kettle always empty, Burning hot upon the stove.PRINTED ITEM W.J. KIRWIN MAR 1970JH 3/70Used I and SupUsed Sup1Used Su
Gamma attenuation, dose rate and exposure/absorption buildup factors of apatite–wollastonite (AW) ceramic system
No full textApatite-wollastonite (AW) is an important biomaterial useful in clinical practice for tissue engineering and other applications. In this research paper, AW and B2O3-doped AW glass ceramics (GCs) were reported and investigated deeply by means of their ability to attenuate gamma-photons. The studied samples denoted by AW, AW-10B, and AW-20B as the B2O3 content from 0 to 20 mol% with the step of 10. Using FLUKA and other theoretical approaches, photon interaction parameters for narrow and broad beam transmission through the AW GCs were estimated for the 15 keV–15 MeV energy range. Also, the density of the GCs increased as the B2O3 content increased. The mass attenuation coefficients were found to be within the ranges 0.0231–13.5659 cm2/g, 0.0225–12.3561 cm2/g, and 0.0220–11.1079 cm2/g for AW, AW-10B, and AW-20B, respectively. The effective atomic number of the GCs fell within the range 11.04–17.26, 10.88–17.01, and 10.21–16.72, respectively. As the doping concentration of B2O3 increased, the gamma energy that the AW GCs were able to absorb decreased. The addition of B2O3 compromised the photon shielding competence of AW in both narrow beam and broad beam scenarios. The GCs had better photon-absorbing competence than some existing gamma-photon shields. The GCs may thus be used as photon absorbers in clinical practice or in other nuclear applications. © 202
Gamma attenuation, dose rate and exposure/absorption buildup factors of apatite-wollastonite (AW) ceramic system
No full textApatite-wollastonite (AW) is an important biomaterial useful in clinical practice for tissue engineering and other applications. In this research paper, AW and B2O3-doped AW glass ceramics (GCs) were reported and investigated deeply by means of their ability to attenuate gamma-photons. The studied samples denoted by AW, AW10B, and AW-20B as the B2O3 content from 0 to 20 mol% with the step of 10. Using FLUKA and other theoretical approaches, photon interaction parameters for narrow and broad beam transmission through the AW GCs were estimated for the 15 keV-15 MeV energy range. Also, the density of the GCs increased as the B2O3 content increased. The mass attenuation coefficients were found to be within the ranges 0.0231-13.5659 cm2/g, 0.0225-12.3561 cm2/g, and 0.0220-11.1079 cm2/g for AW, AW-10B, and AW-20B, respectively. The effective atomic number of the GCs fell within the range 11.04-17.26, 10.88-17.01, and 10.21-16.72, respectively. As the doping concentration of B2O3 increased, the gamma energy that the AW GCs were able to absorb decreased. The addition of B2O3 compromised the photon shielding competence of AW in both narrow beam and broad beam scenarios. The GCs had better photon-absorbing competence than some existing gamma-photon shields. The GCs may thus be used as photon absorbers in clinical practice or in other nuclear applications
Substrate recognition by ribosome-inactivating protein studied by molecular modeling and molecular electrostatic potentials
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