A Non-Gaussian Spatial Generalized Linear Latent Variable Model     

Irina Irincheeva  Eva Cantoni  Marc G. Genton 《Journal of Agricultural, Biological & Environmental Statistics》2012,17(3):332-353

We consider a spatial generalized linear latent variable model with and without normality distributional assumption on the latent variables. When the latent variables are assumed to be multivariate normal, we apply a Laplace approximation. To relax the assumption of marginal normality in favor of a mixture of normals, we construct a multivariate density with Gaussian spatial dependence and given multivariate margins. We use the pairwise likelihood to estimate the corresponding spatial generalized linear latent variable model. The properties of the resulting estimators are explored by simulations. In the analysis of an air pollution data set the proposed methodology uncovers weather conditions to be a more important source of variability than air pollution in explaining all the causes of non-accidental mortality excluding accidents.  相似文献   

Accumulation of coal humic acids by wheat seedlings: Direct evidence using tritium autoradiography and occurrence in lipid fraction          下载免费PDF全文

Natalia A. Kulikova  Gennadii A. Badun  Viktor I. Korobkov  Maria G. Chernysheva  Eugenia A. Tsvetkova  Dmitry P. Abroskin  Andrey I. Konstantinov  Boris T. Zaitchik  Alexander O. Ruzhitsky  Irina V. Perminova 《植物养料与土壤学杂志》2014,177(6):875-883

Humic acids (HA) are natural organic compounds that are important components of organic matter. The accumulation, distribution, and fate of tritium‐labeled HA prepared from coal were analyzed using wheat (Triticum aestivum L.) seedlings. There was a period of rapid accumulation of HA followed by a slower one in the period from 1 to 24 h. There was a significant decrease in HA accumulation at low temperature, indicating that the slower rate of HA accumulation represented a membrane‐mediated process. HA distribution in plant tissues was analyzed using autoradiography. In all cases, HA concentration was considerably higher in the roots than in the shoots. Detailed examination of autoradiograms showed that there was preferential accumulation of HA in the apices of roots and shoots of wheat seedlings. Lipid fractions were extracted from seedlings and analyzed with thin layer chromatography and gas chromatography–mass spectrometry. These analyses revealed that labeled HA were present in the neutral lipid fraction consisting mainly of alkanes and alkenes, which are usually found in plant waxes, associated with the cuticle and suberized tissues. Based on these data, it is suggested that HA‐derived hydrocarbons may be used in wax biosynthesis. This role could explain the mitigating activity of humic substances under stress conditions.  相似文献   

Monoclonal antibody-based fluorescence polarization immunoassay for sulfamethoxypyridazine and sulfachloropyridazine   总被引：1，自引：0，他引：1  

Wang Z  Zhang S  Nesterenko IS  Eremin SA  Shen J 《Journal of agricultural and food chemistry》2007,55(17):6871-6878

In this paper, a new monoclonal antibody (Mab) against sulfamethoxypyridazine (SMP) was produced, and a fluorescence polarization immunoassay (FPIA) based on the produced Mab was developed and optimized for the qualitative screening analysis of SMP. The Mab was raised from mice immunized with SMP linked to bovine serum albumin (BSA) by carbodiimide activated ester formation, using a succinic anhydride spacer molecule between SMP and BSA. Fluorescein labeled sulfachloropyridazine (SCP) and SMP (tracer) were synthesized and purified by thin layer chromatography (TLC). The developed screening FPIA method can tolerate up to 20% methanol, and satisfactory assay sensitivity can be obtained between pH 4 and pH 8 and at lower salt concentration. The anti-SMP Mab exhibited a high cross-reactivity with SCP. The effect of the tracer structure on the analytical characteristic of the determination and on antigen-antibody binding constants was studied. The limits of detection (LOD) were 0.7 ng/mL for SMP and 0.25 ng/mL for SCP in buffer, respectively, whereas negligible cross-reactivities were exhibited by related sulfonamides. Analysis of SMP and SCP-fortified milk samples by the FPIA showed average recoveries from 60 to 145%.  相似文献   

Endogenous formation of N'-nitrosonornicotine in F344 rats in the presence of some antioxidants and grape seed extract     

Porubin D  Hecht SS  Li ZZ  Gonta M  Stepanov I 《Journal of agricultural and food chemistry》2007,55(17):7199-7204

N'-Nitrosonornicotine (NNN) is one of the most abundant strong carcinogens in unburned tobacco and cigarette smoke and is classified by the International Agency for Research on Cancer as carcinogenic to humans. Human exposure to NNN mainly occurs upon use of tobacco products. It is also possible that additional amounts of NNN are formed endogenously. The goal of this study was to evaluate the inhibitory effect of some antioxidants, including ascorbic acid and grape seed extract (GSE), on endogenous NNN formation in rats treated with nornicotine and sodium nitrite by gavage twice daily for 3 days. The study included four groups of rats: (1) negative control group A, to which no chemical was administered; (2) negative control group B, treated with nornicotine alone (2.5 micromol per gavage); (3) positive control group, to which both nornicotine (2.5 micromol per gavage) and sodium nitrite (7.5 micromol per gavage) were administered; and (4) rats treated with nornicotine (2.5 micromol per gavage), inhibitor (7.5 or 37.5 micromol per gavage), and sodium nitrite (7.5 micromol per gavage). The mean (+/-SD) total amount of NNN in the 3-day urine of rats treated with both nornicotine and sodium nitrite was 4.78 +/- 2.88 nmol. The order of inhibition of endogenous NNN formation in rats at the molar ratio [nitrite]:[inhibitor] 1:5 was as follows: ascorbic acid (91%) > dihydroxyfumaric acid (86%) approximately catechin (85%) > resveratrol (no inhibition). Treatment of rats with grape seed extract did not produce statistically significant inhibition of endogenous nornicotine nitrosation. This is the first study that demonstrates endogenous NNN formation in rats treated with nornicotine and sodium nitrite and effective inhibition of this process by ascorbic acid, dixydroxyfumaric acid, and catechin.  相似文献   

Glacial survival of boreal trees in northern Scandinavia     

Parducci L  Jørgensen T  Tollefsrud MM  Elverland E  Alm T  Fontana SL  Bennett KD  Haile J  Matetovici I  Suyama Y  Edwards ME  Andersen K  Rasmussen M  Boessenkool S  Coissac E  Brochmann C  Taberlet P  Houmark-Nielsen M  Larsen NK  Orlando L  Gilbert MT  Kjær KH  Alsos IG  Willerslev E 《Science (New York, N.Y.)》2012,335(6072):1083-1086

It is commonly believed that trees were absent in Scandinavia during the last glaciation and first recolonized the Scandinavian Peninsula with the retreat of its ice sheet some 9000 years ago. Here, we show the presence of a rare mitochondrial DNA haplotype of spruce that appears unique to Scandinavia and with its highest frequency to the west-an area believed to sustain ice-free refugia during most of the last ice age. We further show the survival of DNA from this haplotype in lake sediments and pollen of Tr?ndelag in central Norway dating back ~10,300 years and chloroplast DNA of pine and spruce in lake sediments adjacent to the ice-free And?ya refugium in northwestern Norway as early as ~22,000 and 17,700 years ago, respectively. Our findings imply that conifer trees survived in ice-free refugia of Scandinavia during the last glaciation, challenging current views on survival and spread of trees as a response to climate changes.  相似文献   

Evaluation of reproductive traits and ovarian and uterine morphology of sows with different genotypes for the estrogen receptor,prolactin receptor,and follicle-stimulating hormone subunit beta genes     

Alena Yurina  Evgeny Skovorodin  Irina Dolmatova 《Canadian journal of veterinary research》2021,85(3):186

The purpose of this study was to analyze the morpho-functional features of the ovaries and uterus of sows with different genotypes for the estrogen receptor (ESR), prolactin receptor (PRLR), and follicle-stimulating hormone subunit beta (FSHβ) genes associated with reproductive traits. Healthy Large White sows were studied. The genotypic status of the ESR, PRLR, and FSHβ genes was detected by polymerase chain reaction-restriction fragment length polymorphism. The structure of the ovaries and uterus was studied using quantitative assessment of organs and histological research.Sows with the ESR^BB genotype significantly exceeded animals with the ESR^AA genotype in milk yield (by 0.3 kg) and in the number of piglets at birth (by 0.9 animals) and at weaning (by 0.7 animals). Sows with the ESR^AB genotype were midway between those with ESR^BB and ESR^AA genotypes in terms of these reproductive traits. Animals with the PRLR^AA genotype significantly exceeded those with the PRLR^BB genotype in the number of piglets born (P < 0.05); the differences in litter weight at birth were not significant. Compared to other genotypes, sows with genotypes ESR^BB (P < 0.05) and PRLR^{AA (AB)} (P < 0.05) had larger uteruses and more yellow bodies, tertiary follicles, and primordial follicles in their ovaries. Animals with the FSHβ^BB genotype significantly exceeded animals with the FSHβ^AB genotype in the length of uterus by 21 cm (P < 0.05).  相似文献   

Stand der Hybridweizenzüchtung in der DDR     

W. Merfert    Irina  Schilowa M. Faustmann 《Plant Breeding》1988,101(3):236-244

  相似文献   

Phytoextraction of Thorium from Soil and Water Media     

Irina Shtangeeva  Sophie Ayrault 《Water, air, and soil pollution》2004,154(1-4):19-35

Remediation of ecosystems that have been exposed to radionuclides is of great importance for many countries. At present the remediation efforts using existing technologies are rather expensive. Phytoremediation can serve as a perspective method for rehabilitation of the radioactive contaminated soils and wastes. Among other radio-nuclides, limited information is available on screening and selection of plants for thorium uptake. In our work short-term pot experiments in a greenhouse have been performed to study the phytoextraction of thorium by wheat seedlings grown in soil and different water media artificially contaminated with thorium. Addition of a small amount of thorium to the media resulted in a significant increase of thorium concentration both in roots and leaves of the wheat seedlings. The uptake of Th by roots depended of the media where the plants grew: it was more significant in water-grown plants. The rate of Th translocation from roots to leaves was approximately the same regardless of the growth medium. The bioaccumulation of Th in the wheat resulted inthe removal of Th from the soil and water. During the short-term vegetation test concentration of Th in all the media decreased: in water — 2—5 times, in soil — 1.7 times. Th accumulation in the wheat seedlings affected concentrations and relationships between other elements in the plants. More significant changes were found in the wheat grown in doubly distilled water and in nutrient solution.The most affected part of the plants was the root system.  相似文献   

Nematicidal effects of the entomopathogenic bacteria Bacillus thuringiensis in soil     

Irina N. Mozgovaya  Boris A. Byzov  Nikolai F. Ryabchenko  Nikolai D. Romanenko  Dmitri G. Zvyagintsev 《Pedobiologia》2002,46(6):558-572

  相似文献   

Isolation and multiresidue detection of macrolide endectocides present in animal matrices.   总被引：1，自引：0，他引：1  

Irina Rudik  Margie R Cummings  Robert H Poppenga 《Journal of veterinary diagnostic investigation》2002,14(4):295-302

A simple, rapid, and sensitive method for isolation and detection of macrolide endectocides (moxidectin, doramectin, selamectin, ivermectin, and eprinomectin) in animal sera and liver is described. Fortified sera or homogenized liver samples were treated with sodium chloride followed by organic solvent extraction. No additional steps were required prior to analysis. Separation of analytes and collection of mass information was achieved by liquid chromatography/mass spectrometry with positive atmospheric pressure chemical ionization set in selected ion monitoring mode with each sample analysis complete in 15 minutes. Presence of each compound was confirmed based on 2 separate extracted ion profiles. Detection of avermectins and moxidectin in a range of working standards was achieved at 10, 50, and 100 ppb. Quantitation of these compounds in fortified samples was based on standard calibration curves with R2 > 0.99. Detection limits of 10 ppb for ivermectin, moxidectin, and doramectin, 50 ppb for selamectin, and 100 ppb for eprinomectin were achieved in spiked sera. Recoveries of avermectins and moxidectin in 500 ppb fortified sera fell between 61 and 89% (+/-5.7-15.7). Analysis of fortified liver gave comparable results with recovery of selamectin of 83-91% +/- 18.3. A complete mass spectral fragmentation pattern of selamectin and affordable screening method for 6 macrolide endectocides are reported. Method comparison for salt treatment and solid-phase extraction of fortified samples is discussed.  相似文献