排序方式: 共有69条查询结果,搜索用时 31 毫秒
31.
Ranked set sampling allocation models for multiple skewed variables: an application to agricultural data 总被引:1,自引:0,他引:1
Chiara Bocci Alessandra Petrucci Emilia Rocco 《Environmental and Ecological Statistics》2010,17(3):333-345
The mean of a balanced ranked set sample is more efficient than the mean of a simple random sample of equal size and the precision of ranked set sampling may be increased by using an unbalanced allocation when the population distribution is highly skewed. The aim of this paper is to show the practical benefits of the unequal allocation in estimating simultaneously the means of more skewed variables through real data. In particular, the allocation rule suggested in the literature for a single skewed distribution may be easily applied when more than one skewed variable are of interest and an auxiliary variable correlated with them is available. This method can lead to substantial gains in precision for all the study variables with respect to the simple random sampling, and to the balanced ranked set sampling too. 相似文献
32.
Ten adult male loggerhead sea turtles, captured by trawlers or dip nets, were satellite-tracked from a neritic foraging ground in the Mediterranean in order to investigate adult spatio-temporal distribution and breeding migration. Five individuals migrated to potential breeding sites in Libya and one to Greece. The results complement previous studies and show that: (1) the Tunisian shelf may be more important for turtles from Libyan rookeries than previously thought; (2) male tracks corroborate a conservation hotspot previously identified for juveniles; (3) the north African coast represents a preferred migratory corridor, unless open sea routes are more direct; (4) adult males may exhibit high fidelity to relatively small areas, without evident seasonal differences; (5) adults home ranges were smaller and more neritic than juveniles frequenting the same area; (6) males may frequent multiple courtship areas; (7) the average remigration interval of males frequenting this region is longer than 1 year. 相似文献
33.
Abstract Dissolved iodine in sea water, about 60 μg L?1, usually exists in equal proportions as iodate and iodide ions. For their determination several techniques have been proposed (Riley, 1975); among them the volumetric one which depends upon the release of elementary iodine by the addition of acid and iodide ions to the iodate present in the sample. The liberated iodine is titrated with thiosulphate the equivalence point being detected photometrically (Matthews and Riley, 1970; Wong and Brewer, 1974) or it can also be reduced with an excess of thiosulphate and the residual thiosulphate back-titrated with iodate amperometrically (Barkley and Thompson, 1960; Truesdale and Spencer, 1974; Tsonkova and Kulev, 1981). To titrate total iodine in the sample the iodide must be previously oxidized to iodate with bromine (Barkley and Thompson, 1960; Tsonkova and Kulev, 1981) or permanganate (Schnepfe, 1972). In the amperometric procedure Truesdale and Spencer (1974) observed that platinum electrodes often do not respond reliably. 相似文献
34.
Claudio Rocco Antonio Andrea Gentile 《International Journal of Sustainable Engineering》2016,9(3):197-205
The novel “Palette Modular Device” (PMD) technology, addressing the recovery of wastes from Physical Vapour Deposition (PVD) maintenance, is evaluated according to a Life Cycle Assessent (LCA) approach. The PMD recovery technology was recently developed with the aim of an easier and more sustainable separation of the film layers used in PVD, with a particular emphasis on multi-material film productions, frequently adopted in the electronic industry. The PMD is briefly presented in the paper, along with three implementations for industrial purposes. Each implementation adopts a different light solvent for the metal recovery like acetone and formic acid. The usage of light solvents is a peculiar feature enabled by the system considered, as an alternative to traditional approaches. The LCA starts with the objectives and prosecutes with inventories of all material and energy flows for each different scenario considered. Additionally, a global impact assessment is provided in a specific section, in order to enable a quantitative comparison of the potential effects on the environment in every scenario. The results of this study allow the industrial designer to perform an overall environmental evaluation of the three strategies proposed and to compare the performances of the novel technology. The research, furthermore, highlights some critical points in the adoption of the PMD and suggests how to improve the implementation of this recovery process. 相似文献
35.
36.
In human dominated landscapes, ecosystems are under increasing pressures caused by urbanization and infrastructure development.
In Alpine valleys remnant natural areas are increasingly affected by habitat fragmentation and loss. In these contexts, there
is a growing risk of local extinction for wildlife populations; hence assessing the consequences on biodiversity of proposed
land use changes is extremely important. The article presents a methodology to assess the impacts of land use changes on target
species at a local scale. The approach relies on the application of ecological profiles of target species for habitat potential
(HP) assessment, using high resolution GIS-data within a multiple level framework. The HP, in this framework, is based on
a species-specific assessment of the suitability of a site, as well of surrounding areas. This assessment is performed through
spatial rules, structured as sets of queries on landscape objects. We show that by considering spatial dependencies in habitat
assessment it is possible to perform better quantification of impacts of local-level land use changes on habitats. 相似文献
37.
Anna Doffini Claudio Forcato Chiara Mangano Debora Lattuada Roberta Aversa Chiara Maranta Emilia D. Giovannone Genny Buson Chiara Bolognesi Rebecca Maiocchi Martina Dori Liyana Jamal Raidah B. Ahmad George S. H. Yeo Tai Wai Yeo Silvia Saragozza Rosamaria Silipigni Marta Serafini Andrea Biondi Sofia Perego Patrizia Vergani Enrico Ferrazzi Paola Ricciardi-Castagnoli Thomas J. Musci Francesca Romana Grati 《黑龙江环境通报》2023,43(1):14-27
Objective
To develop a multi-step workflow for the isolation of circulating extravillous trophoblasts (cEVTs) by describing the key steps enabling a semi-automated process, including a proprietary algorithm for fetal cell origin genetic confirmation and copy number variant (CNV) detection.Methods
Determination of the limit of detection (LoD) for submicroscopic CNV was performed by serial experiments with genomic DNA and single cells from Coriell cell line biobank with known imbalances of different sizes. A pregnancy population of 372 women was prospectively enrolled and blindly analyzed to evaluate the current workflow.Results
An LoD of 800 Kb was demonstrated with Coriell cell lines. This level of resolution was confirmed in the clinical cohort with the identification of a pathogenic CNV of 800 Kb, also detected by chromosomal microarray. The mean number of recovered cEVTs was 3.5 cells per sample with a significant reverse linear trend between gestational age and cEVT recovery rate and number of recovered cEVTs. In twin pregnanices, evaluation of zygosity, fetal sex and copy number profiling was performed in each individual cell.Conclusion
Our semi-automated methodology for the isolation and single-cell analysis of cEVTS supports the feasibility of a cell-based noninvasive prenatal test for fetal genomic profiling. 相似文献38.
Nicolino Antonella Ligato Mattia Rocco Ferraro Mario Procopio Salvatore 《Environmental science and pollution research international》2022,29(17):25020-25028
Environmental Science and Pollution Research - Radon exhalation from soil and ores is among the most dangerous risks for the public health care. The impact becomes even more powerful when... 相似文献
39.
40.
Sabrina Portofino Antonio Donatelli Pierpaolo Iovane Carolina Innella Rocco Civita Maria Martino Domenico Antonio Matera Antonio Russo Giacinto Cornacchia Sergio Galvagno 《Waste management (New York, N.Y.)》2013,33(3):672-678
An experimental survey of waste tyre gasification with steam as oxidizing agent has been conducted in a continuous bench scale reactor, with the aim of studying the influence of the process temperature on the yield and the composition of the products; the tests have been performed at three different temperatures, in the range of 850–1000 °C, holding all the other operational parameters (pressure, carrier gas flow, solid residence time). The experimental results show that the process seems promising in view of obtaining a good quality syngas, indicating that a higher temperature results in a higher syngas production (86 wt%) and a lower char yield, due to an enhancement of the solid–gas phase reactions with the temperature. Higher temperatures clearly result in higher hydrogen concentrations: the hydrogen content rapidly increases, attaining values higher than 65% v/v, while methane and ethylene gradually decrease over the range of the temperatures; carbon monoxide and dioxide instead, after an initial increase, show a nearly constant concentration at 1000 °C. Furthermore, in regards to the elemental composition of the synthesis gas, as the temperature increases, the carbon content continuously decreases, while the oxygen content increases; the hydrogen, being the main component of the gas fraction and having a small atomic weight, is responsible for the progressive reduction of the gas density at higher temperature. 相似文献