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81.
Alessandra Capponi Dr Giuseppe Rizzo Donatella Rinaldo Domenico Arduini Carlo Romanini 《黑龙江环境通报》1995,15(11):1007-1016
The objective of this study was to evaluate the effect of fetal blood sampling on cardiac flow velocity waveforms. Flow velocity waveforms were measured from the ascending aorta and pulmonary artery immediately before and after fetal blood sampling in 29 normally grown and 12 growth-retarded fetuses. The latter group was characterized by abnormal Doppler indices in the umbilical artery and middle cerebral artery suggestive of uteroplacental insufficiency as the causative factor of the impaired growth. The flow velocity parameters studied were the peak velocity, the time to peak velocity, and the left and right cardiac output and their ratio. In normally grown fetuses, the peak velocity and right and left cardiac output values increased significantly after fetal blood sampling, while no significant changes were observed in the other indices considered. The gestational age at the time of the procedure was positively related to the amplitude of these changes. In growth-retarded fetuses, fetal blood sampling did not induce any significant increase in cardiac output or peak velocities, while in more than 50 per cent of the fetuses these Doppler indices decreased. The amplitude of the decrease was significantly related to the severity of acidosis in the umbilical vein. In conclusion, the cardiac haemodynamic response to fetal blood sampling differs between normally grown and growth-retarded fetuses. This difference may explain the higher rate of complications occurring in the latter group of fetuses after blood sampling. 相似文献
82.
Marco Barucca Francesca Azzini Giorgio Bavestrello Maria Assunta Biscotti Barbara Calcinai Adriana Canapa Carlo Cerrano Ettore Olmo 《Marine Biology》2007,151(2):529-535
A phylogenetic analysis of some bioeroding sponges of the family Clionaidae (Order Hadromerida) was performed to resolve some
taxonomic problems both at the specific and the supraspecific level using the D2 and D3 regions of 28S rDNA. Species belonging
to the genera Cliona, Cliothosa, Spheciospongia (fam. Clionaidae) and Diplastrella (fam. Spirastrellidae) from the Mediterranean Sea and Celebes Sea (Indonesia) were analysed. In the phylogenetic tree, the
species clustered on two main branches, one comprising Cliona celata, C. rhodensis, C. utricularis, and Cliothosa hancocki, and the other made up of C. viridis, C. nigricans, C. schmidti, C. jullieni, Spheciospongia solida and S. vagabunda. Above the species level, data do not support the separation of the genus Cliothosa from Cliona, while they do support the inclusion of some massive boring species, previously assigned to the genus Spirastrella, in the family Clionaidae. At the species level, data demonstrated the genetic identity of taxa C. viridis and C. nigricans, in spite of their considerable morphological differences. In contrast, the yellow species commonly attributed to C. celata are probably to be considered as a complex of sibling species with a number of distinct taxa present in the Mediterranean.
Data also showed the identity of the Mediterranean and Pacific populations of C. schmidti, suggesting the status of a Tethyan relict for this species. 相似文献
83.
Moreno Di Marco Thomas Brooks Annabelle Cuttelod Lincoln D.C. Fishpool Carlo Rondinini Robert J. Smith Leon Bennun Stuart H.M. Butchart Simon Ferrier Ruud P.B. Foppen Lucas Joppa Diego Juffe‐Bignoli Andrew T. Knight John F. Lamoreux Penny F. Langhammer Ian May Hugh P. Possingham Piero Visconti James E.M. Watson Stephen Woodley 《Conservation biology》2016,30(2):392-402
World governments have committed to increase the global protected areas coverage by 2020, but the effectiveness of this commitment for protecting biodiversity depends on where new protected areas are located. Threshold‐ and complementarity‐based approaches have been independently used to identify important sites for biodiversity. We brought together these approaches by performing a complementarity‐based analysis of irreplaceability in important bird and biodiversity areas (IBAs), which are sites identified using a threshold‐based approach. We determined whether irreplaceability values are higher inside than outside IBAs and whether any observed difference depends on known characteristics of the IBAs. We focused on 3 regions with comprehensive IBA inventories and bird distribution atlases: Australia, southern Africa, and Europe. Irreplaceability values were significantly higher inside than outside IBAs, although differences were much smaller in Europe than elsewhere. Higher irreplaceability values in IBAs were associated with the presence and number of restricted‐range species; number of criteria under which the site was identified; and mean geographic range size of the species for which the site was identified (trigger species). In addition, IBAs were characterized by higher irreplaceability values when using proportional species representation targets, rather than fixed targets. There were broadly comparable results when measuring irreplaceability for trigger species and when considering all bird species, which indicates a good surrogacy effect of the former. Recently, the International Union for Conservation of Nature has convened a consultation to consolidate global standards for the identification of key biodiversity areas (KBAs), building from existing approaches such as IBAs. Our results informed this consultation, and in particular a proposed irreplaceability criterion that will allow the new KBA standard to draw on the strengths of both threshold‐ and complementarity‐based approaches. 相似文献
84.
85.
Pedro A. Ochoa George Alexis Sagastume Gutiérrez Juan B. Cogollos Martínez Carlo Vandecasteele 《Journal of Cleaner Production》2010,18(12):1171-1176
An approach to Cleaner Production in a small factory of hydrated lime is presented. The work aims to improving fuel and limestone utilization and reducing waste production in the plant. Efforts mainly focus on the calcination stage, where around 50% of the production costs due to fuel consumption occur. To fulfill this objective, new indicators are proposed to evaluate the performance of the lime shaft kiln, in order to develop an operational control method for the calcination process. The systematic use of the developed operational control method is a powerful tool in the daily operation of a small lime factory, since it allows a more efficient calcination process with reduced environmental impact and production cost. 相似文献
86.
A positive surge results from a sudden change in flow that increases the depth. It is the unsteady flow analogy of the stationary
hydraulic jump and a geophysical application is the tidal bore. Positive surges are commonly studied using the method of characteristics
and the Saint-Venant equations. The article presents the results from new experimental investigations conducted in a large
rectangular channel. Detailed unsteady velocity measurements were performed with a high temporal resolution using acoustic
Doppler velocimetry and non-intrusive free-surface measurement devices. Several experiments were conducted with the same initial
discharge (Q = 0.060 m3/s) and six different gate openings after closure resulting in both non-breaking undular and breaking bores. The analysis
of undular surges revealed wave amplitude attenuation with increasing distance of surge propagation were in agreement with
Ippen and Kulin theory. Also, undular wave period and wave length data were relatively close to the values predicted by the
wave dispersion theory for gravity waves in intermediate water depths. 相似文献
87.
Manzo Sonia Parrella Luisa Schiavo Simona Spaziani Fabio Chiavarini Salvatore Tebano Carlo De Maio Lucio Capone Stefano Siciliano Anna Valeria Armiento Giovanna 《Environmental science and pollution research international》2022,29(55):83291-83303
Environmental Science and Pollution Research - In this study we propose, a multi-step strategy of selection and characterization of long-term dataset of contaminant concentrations in different... 相似文献
88.
For many plant species, seed dispersal is one of the most important spatial demographic processes. We used a diffusion approximation and a spatially explicit simulation model to explore the mechanisms generating seed dispersal kernels for plants dispersed by frugivores. The simulation model combined simple movement and foraging rules with seed gut passage time, plant distribution, and fruit production. A simulation experiment using plant spatial aggregation and frugivore density as factors showed that seed dispersal scale was largely determined by the degree of plant aggregation, whereas kernel shape was mostly dominated by frugivore density. Kernel shapes ranged from fat tailed to thin tailed, but most shapes were between an exponential and that of the solution of a diffusion equation. The proportion of dispersal kernels with fat tails was highest for landscapes with clumped plant distributions and increased with increasing number of dispersers. The diffusion model provides a basis for models including more behavioral details but can also be used to approximate dispersal kernels once a diffusion rate is estimated from animal movement data. Our results suggest that important characteristics of dispersal kernels will depend on the spatial pattern of plant distribution and on disperser density when frugivores mediate seed dispersal. 相似文献
89.
90.
Gloria Antonini Paolo Audisio Emiliano Mancini Alessio De Biase Carlo Tronci Giulia Rossetti Marco Trizzino 《Marine Biology》2010,157(2):371-381
Marine rock-pools, commonly found along the Mediterranean coasts, are isolated patches of habitat characterised by large spatial
and temporal variations. The phylogeography of Calobius quadricollis and C. urbanelliae, two sibling species of moss beetles (Coleoptera, Hydraenidae) inhabiting Italian temporary marine rock-pool ecosystems,
were studied using mitochondrial cytochrome c oxidase subunit I (COI). Our data suggest a strong association between the scored
genetic variability and the geographical distribution of populations sampled for both species. These analyses provided evidences
of episodic species range expansion and fragmentation, recurrent “flush and crash” and bottleneck episodes probably occurring
during the Glacial Cycles. The observed phylogeographical pattern is probably related to the historical and biogeographical
processes of Mediterranean areas, as well as both to the ephemeral habitat tipology and limited dispersal ability of these
beetles. 相似文献