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291.
292.
Dario Di Giuseppe Gianluca Bianchini Livia Vittori Antisari Annalisa Martucci Claudio Natali Luigi Beccaluva 《Environmental monitoring and assessment》2014,186(5):2925-2940
This geochemical study is focused on the easternmost part of the Po River alluvial plain in Northern Italy, which is interested by widespread agricultural activities, investigating a reclaimed sector of the Province of Ferrara, known as “Valle del Mezzano” (Mezzano Low Land, hereafter reported as MLL) characterized by peat-rich soils. The chemical–mineralogical characterization of these reclaimed soils is important to compare the local geochemical backgrounds with those recorded in other sectors of the River Po plain and to monitor if the observed concentration exceeds critical thresholds. The reported analyses include (a) measurement of the soil salinity, (b) nutrient evaluation, (c) major and trace element concentrations carried out on bulk soils, (d) tests of metal extraction with both aqua regia and EDTA to highlight the distinct elemental mobility and (e) phyto-toxicological measurement of heavy metal concentrations in plants (Lactuca sativa acephala) grown on the studied soils. The results indicate (1) high soil salinity, often with drastic increase of sodium and chloride along the soil profiles, (2) high nitrogen content (in part related to anthropogenic activities) on superficial horizons and nitrate decrease along the soil profiles and (3) comparative enrichments in heavy metals with respect to other soils of the province, which indicate that peat deposits are effective in trapping metals from anthropogenic sources. This, in turn, implies potential geochemical risks for the agricultural activities. In this regard, specific concerns are related to the high nickel and arsenic content of MLL soils due to the mobility of these elements and their attitude to be taken up by plants. 相似文献
293.
Chiara Guarisco Giovanni Palmisano Giuseppe Calogero Rosaria Ciriminna Gaetano Di Marco Vittorio Loddo Mario Pagliaro Francesco Parrino 《Environmental science and pollution research international》2014,21(19):11135-11141
Sensitized P25 TiO2 was prepared by wet impregnation with a home-prepared perylene dye, i.e., N,N′-bis(2-(1-piperazino)ethyl)-3,4,9,10-perylene-tetracarboxylic acid diimide dichloride (PZPER). Energy levels of PZPER were found to be compatible with those of TiO2 allowing fast electron transfer. The obtained catalyst has been characterized and used in the gas-phase partial oxidation of aliphatic primary and secondary alcohols, i.e., methanol, ethanol, and 2-propanol. The reaction was carried out under cut-off (λ?>?400 nm) simulated solar radiation in O2 atmosphere. The perylene derivative allowed a good absorbance of visible radiation thanks to its low optical energy gap (2.6 eV) which was evaluated by cyclic voltammetry. The optimal organic sensitizing amount was found to be 5.6 % w/w in terms of yield in carbonyl derivatives. Moreover, no change in reactivity/selectivity was observed after 10-h irradiation thus confirming the catalyst stability. Yields into formaldehyde, acetaldehyde, and acetone were 67, 70, and 96 %, respectively. No significant amounts of organic byproducts were detected but for methanol oxidation, whereas a minor amount of the substrate degraded to CO2. 相似文献
294.
Fatty acid trophic markers elucidate resource partitioning within the demersal fish community of South Georgia and Shag Rocks (Southern Ocean) 总被引:2,自引:1,他引:1
Fatty acid analysis was used to study the trophic ecology of 10 demersal fish species in the South Georgia region. Principal component analysis grouped the species into three general clusters, revealing resource partitioning between species. Two groups were characterised by large proportions of either monounsaturated or polyunsaturated fatty acids, separating species according to their predominant feeding habitat. The third group showed fatty acid signatures overlapping with either or both of the previous two groups, suggesting a more opportunistic feeding behaviour for these species. Intraspecific comparisons furthermore revealed dietary variability with size, year and geographical location in several species. Mackerel icefish (Champsocephalus gunnari) in particular showed inter-annual differences in muscle lipid concentrations closely linked to prey availability with low lipid contents found in years of low krill (Euphausia superba) abundance. Despite the intraspecific differences the majority of species could be easily distinguished from each other, which indicates the utility of this method in the dietary analysis of higher predators. 相似文献
295.
Mauro De Marchis Giuseppe Ciraolo Carmelo Nasello Enrico Napoli 《Environmental Fluid Mechanics》2012,12(1):81-100
The hydrodynamic circulation is analyzed in the coastal lagoon of Stagnone di Marsala, a natural reserve located in the north-western part of Sicily, using both experimental measurements and numerical simulations.
Field measurements of velocities and water levels, carried out using an ultrasound sensor (3D), are used to validate the numerical
model. A 3D finite-volume model is used to solve the Reynolds-averaged momentum and mass balance differential equations on
a curvilinear structured grid, employing the k–e{\varepsilon} turbulence model for the Reynolds stresses. The numerical analysis allows to identify the relative contribution of the forces
affecting the hydrodynamic circulation inside the lagoon. In the simulations only wind and tide forces are considered, neglecting
the effects of water density changes. Two different conditions are considered. In the first both the wind stress over the
free-surface and the tidal motion are imposed. In the second the wind action is neglected, to separately analyze the tide-induced
circulation. The comparison between the two test cases highlights the fundamental role of the wind on the hydrodynamics of
the Stagnone lagoon, producing a strong vertical recirculation pattern that is not observed when the flow is driven by tides
only. 相似文献
296.
Giuseppe?BoncoraglioEmail author Manuela?Caprioli Nicola?Saino 《Behavioral ecology and sociobiology》2012,66(4):539-546
Reproduction entails parental decisions over allocation of limiting resources. ‘Begging’ solicitation displays by the offspring
have been hypothesised to evolve as reliable indicators of quality, allowing parents to adopt optimal allocation strategies.
To function as such, however, begging signals must covary with offspring traits that affect viability. Here we tested whether
oxidative damage of nestling barn swallows predicts begging bout duration, call amplitude and intensity of postural displays
both under normal food provisioning and under food shortage. Oxidative damage as determined by normal metabolism, pathological
conditions and functioning of the immune system can serve as a comprehensive indicator of offspring condition because it can
profoundly affect viability, senescence and reproduction. Begging bout duration was negatively predicted by oxidative damage
but only after food deprivation. Postural begging negatively covaried with oxidative damage, at least when nestlings were
confronted with related nest mates. Plasma antioxidant capacity did not predict begging behaviour. Thus, we show for the first
time that behavioural begging covaries with a comprehensive index of chick condition, lending support to reliability of such
begging traits also as signals of quality rather than need or hunger only. Future studies are candidate to decouple the effect
of hunger state and individual condition on behavioural begging. 相似文献
297.
Daniel B. Wright James A. Smith Gabriele Villarini Mary Lynn Baeck 《Journal of the American Water Resources Association》2014,50(3):713-734
Accurate records of high‐resolution rainfall fields are essential in urban hydrology, and are lacking in many areas. We develop a high‐resolution (15 min, 1 km2) radar rainfall data set for Charlotte, North Carolina during the 2001‐2010 period using the Hydro‐NEXRAD system with radar reflectivity from the National Weather Service Weather Surveillance Radar 1988 Doppler weather radar located in Greer, South Carolina. A dense network of 71 rain gages is used for estimating and correcting radar rainfall biases. Radar rainfall estimates with daily mean field bias (MFB) correction accurately capture the spatial and temporal structure of extreme rainfall, but bias correction at finer timescales can improve cold‐season and tropical cyclone rainfall estimates. Approximately 25 rain gages are sufficient to estimate daily MFB over an area of at least 2,500 km2, suggesting that robust bias correction is feasible in many urban areas. Conditional (rain‐rate dependent) bias can be removed, but at the expense of other performance criteria such as mean square error. Hydro‐NEXRAD radar rainfall estimates are also compared with the coarser resolution (hourly, 16 km2) Stage IV operational rainfall product. Stage IV is adequate for flood water balance studies but is insufficient for applications such as urban flood modeling, in which the temporal and spatial scales of relevant hydrologic processes are short. We recommend the increased use of high‐resolution radar rainfall fields in urban hydrology. 相似文献
298.
An obvious means to secure paternity is the production of a mating plug that blocks the female genital opening after mating. Although the mechanical efficacy and persistence of plugs on/in the female genital openings are key traits that determine the degree of paternity protection, these factors have hardly been explored. We therefore investigated the influence of the size of the amorphous plug material (experimentally terminated mating duration as a proxy) and age of the mating plug (time interval between copulations with two successive males) on the efficacy of the plug by analysing the mating success of subsequent males in the dwarf spider Oedothorax retusus (Linyphiidae: Erigoninae). Overall, subsequent males attempted to mate in 82 % of trials but only 32.5 % of these resulted in copulation, demonstrating that the plugs are effective safeguards against remating. Remating probability was significantly higher after previous short copulations (~small plug size) compared to long copulations (~large plug size). In the small plug group, fresh plugs (short remating intervals) were significantly less effective compared to older plugs. In the large plug group, remating probability was similarly low over all remating intervals. The observed copulations, however, do not necessarily result in sperm transfer, since sperm masses were found on the plugged female genital area. Our study on O. retusus shows that mating plugs are a powerful mechanical safeguard whose efficacy varies with plug size and age. We discuss these findings in the light of theoretical considerations on the evolution of effective mating plugs. 相似文献
299.
Professor Bruno Dallapiccola Leopoldo Zelante Gianni Perla Giuseppe Villani 《黑龙江环境通报》1984,4(5):383-386
Cyst-like masses in the neck and back region, simulating an encephalocele, were detected by midtrimester ultrasound examinations in two sib fetuses. After termination, the fetuses were found to have large cystic hygromas. The present observation strongly suggests the existence of an autosomal recessive type of cystic hygroma. 相似文献
300.
Chemical investigation of the deepwater sponge Macandrewia azorica, collected from the flanks of the Gettysburg and Ormonde Sea Mount, North Atlantic, from a depth of 600 m, has led to the isolation of a new sterol with an unusual side chain (1), along with S-methylergothioneine (2). The structures of compounds 1 and 2 were established by employing spectroscopic techniques (NMR, MS, UV, IR and polarimetry). This is the first report of metabolites of a sponge belonging to the genus Macandrewia. 相似文献