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801.
Fonda Umani S Milani L Borme D de Olazabal A Parlato S Precali R Kraus R Lucić D Njire J Totti C Romagnoli T Pompei M Cangini M 《The Science of the total environment》2005,353(1-3):218-231
The temporal dynamics of microphytoplankton, microzooplankton and mesozooplankton were monitored over 37 months in the Adriatic Sea in order to identify alterations in the plankton structures, which can lead to, or enhance the production of macro-aggregates, that affected the entire northern basin in summers 2000 and 2002, and to assess any negative effects of mucilage on plankton temporal patterns. Samples were collected monthly, from June 1999 to July 2002, on three transects at 9 stations across the northern and central Adriatic Sea. Besides the high year-to-year variations in abundances and taxonomical composition, plankton communities only showed a clear seasonal succession during 2001, when since April a grazing food web developed and was able to control large sized phytoplankton increase. In spring-summer 2000 and 2002 consumer abundances remained quite low and the dominant mesozooplankton summer species (Penilia avirostris) did not reach its usual summer maximum. The lack of an efficient top control was more evident on the northernmost transect, where generally grazing food web prevails over the microbial one. A large part of the microphytoplankton blooms, although not particularly intense, was exported to the bottom in the particulate phase, where it was processed by bacteria, enhancing the production of refractory dissolved material. 相似文献
802.
803.
Alessandra Fernicola Maria Assunta Navarra Stefania Panero 《Journal of Applied Electrochemistry》2008,38(7):993-996
In this paper we describe the preparation and the properties of a series of aprotic ionic liquid-based, proton-conducting
membranes. The ionic liquids (ILs) 1,2-dimethyl-3-n-propylimidazolium bis(trifluoromethanesulfonyl)imide and the 3-methyl-1-n-propylpyridinium bis(trifluoromethanesulfonyl)imide are used as the casting solvents of PVdF gel-type membranes; the proton
conductivity is achieved by the addition of a superacid component, namely, trifluoromethanesulfonic acid (HTf) or N,N-bis(trifluoromethanesulfonyl)imide
(HTFSI). The polymer electrolytes showed good thermal and electrochemical properties in the temperature range of interest
for PEMFC applications. The strong coordination between the ILs and the HTFSI, which have the same anion, improves the thermal
stability of this kind of membrane, but lowers the chemical properties and the conductivity, due to an increase in viscosity.
HTf-added samples have an ionic conductivity of 2 × 10−2 S cm−1 at 100 °C, showing the best overall properties and making these membranes of interest applications in fuel cells. 相似文献
804.
Fontanesi L Beretti F Dall'Olio S Portolano B Matassino D Russo V 《The Journal of dairy research》2011,78(1):122-128
Massese is an Italian sheep breed, with black or grey coat colour, mainly reared in the Tuscany and Emilia Romagna regions. Recently, the emerging interests in this breed have resulted in the production of Pecorino cheese obtained with only Massese milk. In order to be profitable, this marketing link between Massese breed and its products should be defended against fraudsters who could include milk of other sheep breeds or cow milk in Massese labelled productions. To identify the genetic factors affecting coat colour in sheep, we have recently analysed the melanocortin 1 receptor (MC1R) gene and identified several single nucleotide polymorphisms (SNPs). In this work, as a first step to set up a DNA based protocol for authentication of Massese dairy products, we further investigated the presence and distribution of one of these SNPs (c.-31G>A) in 143 Massese sheep and in another 13 sheep breeds (for a total of 351 animals). The Massese breed was fixed for allele c.-31A, whereas in all other breeds allele c.-31 G was the most frequent or with frequency of 0?·50. At the same nucleotide position the cattle MC1R gene carries the G nucleotide. Using these data we developed a method to detect adulterating milk (from other sheep breeds or from cow) in Massese dairy products based on the analysis of the c.-31G>A SNP. We first tested the sensitivity of the protocol and then applied it to analyse DNA extracted from ricotta and Pecorino cheese obtained with only Massese milk or obtained with unrestricted sheep and cattle milk. To our knowledge, this system represents the first one that can be used for breed authentication of a sheep production and that, at the same time, can reveal frauds derived from the admixture of milk of an unreported species. 相似文献
805.
Piccione G Messina V Schembari A Casella S Giannetto C Alberghina D 《The Journal of dairy research》2011,78(4):421-425
In dairy cows the period of transition from late gestation to early lactation is recognized as inducing considerable metabolic adaptation. The aim of this study was to analyse modifications in serum protein values occurring during the dry and the transition period and during lactation in a group of five Holstein cows of high average milk production. For all subjects, selected on the basis of their pregnancy status, blood samples were collected at different physiological phases: dry period (-60, -30 d to calving), transition period (almost 7 d to calving, 7 d after calving), and lactation (weeks 2, 5 and 15 after calving), for a total of eight blood samples for each cow. On each blood sample total proteins and electrophoresis analysis were performed. On the data obtained, normally distributed (P<0·05, Kolmogorov-Smirnov's test), one-way Repeated Measure Analysis of Variance (ANOVA), was applied to evaluate the influence of different stages of gestation and lactation on the considered parameters. Results showed a significant effect on total proteins, α1-globulins, β-globulins, γ-globulins and albumin/globulin ratio. Most of the detected modifications were related to the transition from gestation to lactation, indicating that it is a period of great metabolic stress for cows. On the basis of the obtained results we can affirm that the pattern of serum protein fraction rn could give information about dehydration, plasma volume expansion and hepatic function occurring during the peripartum period in dairy cows. 相似文献
806.
Stefania Pellegrinelli Nicola Pedrocchi Lorenzo Molinari Tosatti Anath Fischer Tullio Tolio 《CIRP Annals》2014,63(1):17-20
The necessity to manage several vehicle models on the same robotized assembly cell has made the cell design and the robot off-line motion planning two fundamental activities. Industrial practice and state-of-the-art methods focus on the technical issues of each activity, but no integrated approach has been yet proposed, resulting in a lack of optimality for the final cell configuration. The paper introduces a formalization of the whole process and proposes a heuristic multi-stage method for the identification of the optimal combination of cell design choices and motion planning. The proposed architecture is depicted through a real case for welding application. 相似文献
807.
Loizzo MR Nigro S De Luca D Menichini F 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2011,28(11):1561-1568
The natural occurrence of ochratoxin A (OTA) and cis- and trans-resveratrols in red wines has been widely reported. The aim of this work was to evaluate the ochratoxin A (OTA) and both cis- and trans-resveratrol content of red wine (from must to wine) in a pilot-scale vinification process in Calabria (Italy). Eleven samples were collected at different stages of vinification and analysis was carried out by HPLC. Wine from manufacturer 3 contained the highest amount of trans-resveratrol (3.41 mg l(-1)). This wine was characterized by an Aglianico-Magliocco grape variety. Interestingly, data regarding OTA showed that the value of this contaminant was low in all analyzed samples and, in each case, below the legal limit (2.0 mg l(-1) (ppb)). Overall, the results demonstrated the high quality of wines produced in Calabria. 相似文献
808.
Fibre reinforced soils have been investigated for several decades and different models have been suggested to estimate their improved shear strength. The shear strength of such composite materials is affected by the micro and macro mechanical characteristics of both the fibres and the soils (e.g., relative sizes of fibres and soil grains, fibres aspect ratio, stress state, mechanical properties of the fibres), yet no model is available to explicitly take all of them into account. The aim of this work is to establish a new expression for the shear strength of the reinforced material, able to consider the main characteristics of the soil and the fibres as well as the effect of fibre to grains relative dimensions. Data from triaxial tests carried out on fibre reinforced soils with distinct grain size distributions (from clayey sands to sandy gravels) and from previous experimental works were considered and have been analysed successfully within the proposed framework. 相似文献
809.
Hegseth MN Camus L Gorbi S Regoli F Gabrielsen GW 《The Science of the total environment》2011,409(14):2717-2724
The Herring gull (HG) (Larus argentatus) is naturally exposed to halogenated organic compounds such as polychlorinated biphenyls (PCBs) through its diet. During periods of food scarcity, arctic seabirds experience lipid mobilization, allowing stored lipid soluble contaminants to re-enter the body circulation. In the present study, we investigated the effects of PCB exposure and fasting on the antioxidant defense system in HG chicks. Forty newly hatched chicks were exposed to contaminated cod liver oil for 6 weeks and then fasted for 1 week. We assessed the hepatic total oxyradical scavenging capacity (TOSC) against peroxynitrite, hydroxyl and peroxyl radicals, and measured glutathione (reduced: GSH, and oxidized: GSSG) levels and the enzymatic activities of catalase, glutathione peroxidase, glutathione reductase and superoxide dismutase. The results show that fasting significantly increased the HOC levels in the HG chick livers. Limited effects were observed on antioxidant responses; significant effects were only found for catalase (CAT) activity, Se-dependent GPX activity and the GSH/GSSG ratio in the exposed and fasted group. CAT and Se-dependent GPX activities correlated negatively with the PCB concentrations within this group, and a nonlinear relationship between glutathione and contaminant levels was also found. These effects were generally not observed after exposure or fasting alone and were likely related to the high PCB levels induced by the combination of exposure and fasting. 相似文献
810.
Maurizio Servili Sonia EspostoGianluca Veneziani Stefania UrbaniAgnese Taticchi Ilona Di MaioRoberto Selvaggini Beatrice SordiniGianFrancesco Montedoro 《Food chemistry》2011
Olive-vegetation water (OVW) is very rich in phenols, which can cause pollution problems, due to their high hydrophilicity and antimicrobial activity. In this study, a three-phase membrane system was applied for the recovery of hydrophilic phenols from fresh OVW in an industrial plant, through a prior enzymatic treatment. This innovation yielded both a crude phenolic concentrate (CPC) and a very high reduction in OVW pollution. Furthermore, the CPC was utilised in a virgin olive oil (VOO) extraction process with the aim of improving VOO phenolic content. The results obtained with four different olive cultivars showed that the CPC extraction increased the phenolic content of the VOOs without any alteration of their aroma profiles. 相似文献