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1.
Stefania Korontzi David P. Roy Christopher O. Justice 《Remote sensing of environment》2004,92(2):255-275
This paper uses three recently generated southern African satellite burned area products for the month of September 2000 in a sensitivity study of regional biomass burning emissions for a number of trace gases and particulates. Differences in the extent and location of areas burned among products generated from Moderate Resolution Imaging Spectroradiometer (MODIS), Systeme Pour l'Observation de la Terre (SPOT-VEGETATION), and Along Track Scanning Radiometer (ATSR-2) data are significant and result in different emissions estimates for woodland and grassland land cover types. Due to the different emission profiles in woodlands and grasslands, favoring relatively more products of incomplete combustion in woodlands compared with products of complete combustion in grasslands in the late dry season, these changes are not proportional to the differences in the burned area amounts. The importance of accurate burned area information not just in terms of the total area but also in terms of its spatial distribution becomes apparent from our modeling results. This paper highlights the urgent need for satellite data producers to provide accuracy assessments associated with satellite-derived products. Preferably, these accuracy data will be spatially explicit, or defined in a way that can be applied in a spatially explicit modeling context, to enable emissions uncertainties to be defined with respect to different landscape units in support of greenhouse gas emissions reporting. 相似文献
2.
G Scala I Quinto MR Ruocco M Mallardo C Ambrosino B Squitieri P Tassone S Venuta 《Canadian Metallurgical Quarterly》1993,67(5):2853-2861
Human immunodeficiency virus type 1 (HIV-1)-infected subjects show a high incidence of Epstein-Barr virus (EBV) infection. This suggests that EBV may function as a cofactor that affects HIV-1 activation and may play a major role in the progression of AIDS. To test this hypothesis, we generated two EBV-negative human B-cell lines that stably express the EBNA2 gene of EBV. These EBNA2-positive cell lines were transiently transfected with plasmids that carry either the wild type or deletion mutants of the HIV-1 long terminal repeat (LTR) fused to the chloramphenicol acetyltransferase (CAT) gene. There was a consistently higher HIV-1 LTR activation in EBNA2-expressing cells than in control cells, which suggested that EBNA2 proteins could activate the HIV-1 promoter, possibly by inducing nuclear factors binding to HIV-1 cis-regulatory sequences. To test this possibility, we used CAT-based plasmids carrying deletions of the NF-kappa B (pNFA-CAT), Sp1 (pSpA-CAT), or TAR (pTAR-CAT) region of the HIV-1 LTR and retardation assays in which nuclear proteins from EBNA2-expressing cells were challenged with oligonucleotides encompassing the NF-kappa B or Sp1 region of the HIV-1 LTR. We found that both the NF-kappa B and the Sp1 sites of the HIV-1 LTR are necessary for EBNA2 transactivation and that increased expression resulted from the induction of NF-kappa B-like factors. Moreover, experiments with the TAR-deleted pTAR-CAT and with the tat-expressing pAR-TAT plasmids indicated that endogenous Tat-like proteins could participate in EBNA2-mediated activation of the HIV-1 LTR and that EBNA2 proteins can synergize with the viral tat transactivator. Transfection experiments with plasmids expressing the EBNA1, EBNA3, and EBNALP genes did not cause a significant HIV-1 LTR activation. Thus, it appears that among the latent EBV genes tested, EBNA2 was the only EBV gene active on the HIV-1 LTR. The transactivation function of EBNA2 was also observed in the HeLa epithelial cell line, which suggests that EBV and HIV-1 infection of non-B cells may result in HIV-1 promoter activation. Therefore, a specific gene product of EBV, EBNA2, can transactivate HIV-1 and possibly contribute to the clinical progression of AIDS. 相似文献
3.
Zhao Donghui Wang Hua Chen Guorong Stefania Baccaro Angelica Cecilia Mauro Falconieri L. Pilloni 《Journal of the American Ceramic Society》2006,89(11):3582-3584
Gamma-ray irradiations induced various alterations in sulfur- and selenium-based chalcogenide glasses. The absorbed dose was in the range of 0.01–3.6 MGy. The glasses exhibit prominent sensitivity to γ-ray irradiation, characterized by changes in some of the physical properties of the glasses, e.g., optical transmission, optical band gap, density, and thermal expansion coefficient. The effects on glass structure and microscopic morphology were also studied by Raman spectra and scanning electron microscopic observations. 相似文献
4.
Alicja egota Stefania Bachman 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1987,184(1):3-7
Summary The effect of irradiation on the nonenzymatic browning reaction in the model system consisting of 0,03M-fructose, 0.01M-alanine and 0.01M-phenylalanine in aqueous solution was investigated. The loss of phenylalanine and fructose after irradiation, due to their high reactivity towards radical species of water radiolysis was greater compared with alanine. The heating of preirradiated solution caused only a slight decrease in the concentration of substrates. The characteristic absorption spectra for only irradiated and for irradiated and heated solutions were recorded. The heating produced a chromophore with a broadened absorption maximum about 285 nm. Two unidentified Amadori type compounds which gave positive response to ninhydrin were found by amino-acid analysis.
For part 3 see [8] 相似文献
Durch -Strahlung induzierte nichtenzymatische Bräunung im Modell-System Teil IV. Dreikomponentenmodellsystem aus Fructose, Alanin und Phenylalanin
Zusammenfassung Es wurde der Einfluß von -Strahlen auf die nichtenzymatische Bräunung im Dreikomponenten-Modellsystem, bestehend aus 0,03m-Fructose, 0,01m-Alanin und 0,01m-Phenylalanin in wäßriger Lösung untersucht. Der Verlust an Phenylalanin und Fructose nach der Bestrahlung war größer als bei Alanin wegen dessen größerer Reaktivität zu den Radikalen der Wasserradiolyse. Beim Erhitzen von bestrahlten Losungen wurde eine Abnahme in der Konzentration von Substraten beobachtet. Es wurden die charakteristischen Absorptionsspektren von lediglich bestrahlten und von bestrahlten und gleichzeitig erhitzten Lösungen aufgenommen. Beim Erhitzen wird ein Chromophor mit breitem Absorptionsmaximum bei ungefähr 285 nm, gebildet. Es wurden zwei nichtidentifizierte Amadoriprodukte mit positiver Ninhydrin-Reaktion bei den Aminosäureanalysen gefunden.
For part 3 see [8] 相似文献
5.
Rosalinda Madonna Stefania Moscato Enza Polizzi Damiana Pieragostino Maria Concetta Cufaro Piero Del Boccio Francesco Bianchi Raffaele De Caterina Letizia Mattii 《International journal of molecular sciences》2021,22(11)
Cardiac connexins (Cxs) are proteins responsible for proper heart function. They form gap junctions that mediate electrical and chemical signalling throughout the cardiac system, and thus enable a synchronized contraction. Connexins can also individually participate in many signal transduction pathways, interacting with intracellular proteins at various cellular compartments. Altered connexin expression and localization have been described in diseased myocardium and the aim of this study is to assess the involvement of Cx43, Cx26, and some related molecules in ponatinib-induced cardiac toxicity. Ponatinib is a new multi-tyrosine kinase inhibitor that has been successfully used against human malignancies, but its cardiotoxicity remains worrisome. Therefore, understanding its signaling mechanism is important to adopt potential anti cardiac damage strategies. Our experiments were performed on hearts from male and female mice treated with ponatinib and with ponatinib plus siRNA-Notch1 by using immunofluorescence, Western blotting, and proteomic analyses. The altered cardiac function and the change in Cxs expression observed in mice after ponatinib treatment, were results dependent on the Notch1 pathway and sex. Females showed a lower susceptibility to ponatinib than males. The downmodulation of cardiac Cx43, Cx26 and miR-122, high pS368-Cx43 phosphorylation, cell viability and survival activation could represent some of the female adaptative/compensatory reactions to ponatinib cardiotoxicity. 相似文献
6.
Elisabetta Tornatore Pasquale Vetro Stefania Maria Buccellato 《Neural computing & applications》2014,24(2):309-315
We propose a stochastic disease model where vaccination is included and such that the immunity is permanent. The existence, uniqueness, and positivity of the solution and the stability of the disease-free equilibrium are studied. 相似文献
7.
Stefania Grzeszczyk 《Cement and Concrete Research》1986,16(6):798-804
This paper reports upon the research into the influence of sodium ions on C12A7. The actual research work consisted in synthesizing C12A7, treated with the sodium ions as Na2CO3, within the sodium concentration range of up to 25% Na2O by weight in C12A7. The resultant combinations have been identified by the X-ray analysis, the infra-red spectroscopy and the quantitative chemical analysis.
The identification procedure together with the analysis of free CaO content in the products of C12A7 sodium synthesis gave evidence that sodium which is introduced into the researched amount of C12A7 up to 10% Na2O by weight, contributes to the formation of the ever increasing phase of the solid solutions of Na2O in C3A. The continued increase of the sodium volume ( 15% Na2O by weight ) makes it resolve gradually into sodium aluminate β -NA and free CaO. 相似文献
8.
Alfonso Ranalli Luciano Pollastri Stefania Contento Emilia Iannucci Lucia Lucera 《European Journal of Lipid Science and Technology》2003,105(2):57-67
The influence of the olive paste malaxation time on the composition and the industrial output of oil was investigated. To this purpose, three Italian olive varieties (Leccino, Dritta, Caroleo) were processed with a centrifugal system for six malaxation periods (0, 15, 30, 45, 60 and 75 min). The concentrations of the majority of the oil constituents changed during the malaxation. However, these changes were not significant for all of them: the contents of β‐carotene, the major xanthophylls, chlorophylls a and b, pheophytins a and b in the oils increased progressively with increasing malaxing times, whereas the contents of simple and hydrolysable phenols (secoiridoid derivatives), o‐diphenols and total phenols decreased. A significant increase in total volatiles and green volatiles of the lipoxygenase cascade (C6 aldehydes, C6 alcohols, C5 alcohols and C5 carbonyls) was detected. An opposite trend was observed for the green C6 esters. As a result, the global analytical quality, flavour, aroma and shelf‐life of the oils were negatively affected. The oil yield increased substantially up to 45 min of paste malaxation times. Beyond 60 min, the yields tended to decrease. 相似文献
9.
Stefania Vichi Lorena Pizzale Lanfranco S. Conte 《European Journal of Lipid Science and Technology》2007,109(1):72-78
The positional distribution of fatty acids (FA) in triacylglycerols (TAG) of 47 virgin olive oils from diverse cultivars grown in distinct areas of North‐Eastern Italy was studied. Few data were previously available on oils from these geographical areas. The effects of climatic and geographical conditions on the stereospecific distribution of TAG in olive oil were confirmed. Moreover, the results of the stereospecific analysis were used to evaluate the preferential esterification position of each FA on the basis of the degree of unsaturation and the chain length. The data of the stereospecific analysis of olive oil TAG can contribute to the determination of the selectivity of olive fruit acyltransferases for distinct FA. 相似文献
10.
Fengshuo Hu John J. La Scala Santosh Kumar Yadav James Throckmorton Giuseppe R. Palmese 《应用聚合物科学杂志》2021,138(24):50579
A series of bio-rubber (BR) tougheners for thermosetting epoxy resins was prepared by grafting renewable fatty acids with different chain lengths onto epoxidized soybean oil at varying molar ratios. BR-toughened samples were prepared by blending BRs with diglycidyl ether of bisphenol A resins, Epon 828 and Epon 1001F, at different weight fractions and stoichiometrically cured using an amine curing agent, 4, 4′-methylene biscyclohexanamine (PACM). Fracture toughness properties of the unmodified and BR toughened polymer samples—including critical strain energy release rate (GIc), and critical stress intensity factor (KIc)—were measured to investigate the toughening effect of prepared BRs. It was found that the degree of phase separation and toughening were more controllable relative to similar polymers cured using the aromatic curing agent Epikure W, and the use of higher molecular epoxy resins produces a synergistic effect increasing the toughness much more than similar polymers made with lower molecular weight epoxy resins. Average BR domain sizes ranging from 200 to 900 nm were observed, and formulations with GIc, values KIc as high as 1.0 kJ/m2 and 1.4 MPa m1/2 were attained respectively for epoxy systems with Tg greater than 130°C. 相似文献