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31.
A 'step-by-step' method was used to develop a simplified procedure for calculating pesticide residue levels on fruit at harvest by considering the application of the compound and the relevant routes of loss. The model is applicable to cases where the most important exposure route is by direct spray to the canopy of the crop and where uptake into the plant by the roots can be disregarded. The exposure dose is calculated by considering the proportion of total crop cover represented by the fruits. The loss processes considered are photodegradation, uptake, volatilization and washoff.The outputs of the model were compared with measured residues of pesticides on pear. Analysis of the model fit demonstrates that the model predicted the measured data with a good level of accuracy for four of seven investigated pesticides. The predicted/observed quotients are close to 1, as is the modelling efficiency, and there are no great differences between the predicted and observed values. Taking into account the extreme simplicity of the model and the complexity of the environmental processes considered, these results encourage further research into the modelling of residue behaviour in food commodities.The objectives of this work were to produce a tool to predict pesticide residues in products of plant origin, to complement monitoring of pesticide levels and to be useful in evaluating the effect of government policies on food safety. All predicted values were below the maximum levels fixed for pesticide residues in pear, as amended in Council Directives 86/362/EEC and 90/642/EEC. Copyright (c) 2008 Society of Chemical Industry.  相似文献   
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Anticoagulant poisoning is a common rodent control method in urban areas, but rodents may exhibit versatile feeding behavioural habits in varying environmental conditions. This study has been conducted to determine those environmental factors that could directly influence bait consumption and which therefore may affect an urban rodent control plan carried out with chemical methods. In the city of Bologna (Italy), 2500 bait stations have been monitored in various urban biotopes and the bait consumption studied in relation to several environmental factors, using both bivariate and multivariate analysis. Results reveal that the rodent patch distribution triggers the avoidance of baits placed outside of their home-range, hence the importance on bait placement. The logistic regression model confirms that vegetation, harbourage and water supplies are important variables in determining bait consumption, probably because they may spatially and temporarily facilitate the agoraphobic rodent movement, ensuring undisturbed bait consumption. The role of predators (dogs and cats) and food competitors (synanthropic birds) remains insignificant. However, bait eating invertebrates may consume part of the bait. For a proper rodent control plan the first real need is to minimize the alternative food sources, which may compete with baits. Weather conditions in which rodents could possibly pass unnoticed (fog and rainfall) may encourage bait consumption, vice versa with a cold climate. The considered environmental factors have satisfactorily explained bait consumption, highlighting the importance of human influence. The study of environmental factors may be useful in categorizing several site-specific conditions where rodent control efforts should be targeted, enhancing any intervention by matching the correct and specific strategy.  相似文献   
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Sequence Tagged Microsatellite Sites (STMSs) and morphological trait markers were used to evaluate 33 rhododendron germplasm for genetic diversity assessment and discrimination power. The average genetic diversity estimates were 0.724 (morphological traits) and 0.174 (STMSs) marker datasets. The Shannon index was higher for morphological traits (1.797) than STMS (0.302). The correlation coefficients obtained by the Mantel matrix correspondence test, which was used to compare the cophenetic matrices for the two markers, showed that estimated values of relationships given for morphological and STMS were not significantly related (p > 0.05). The dataset from STMS, supported by the total probability of identity (1.13 × 10−9) and total paternity exclusion probability (0.9999), allowed all accessions to be uniquely identified. In summary, STMS marker proved to be an efficient tool in assessing the genetic variability among old broad leaf rhododendron genotypes. The pattern of variation appeared to be consistent, and it can be used for germplasm conservation and management for restoration of historical genetic resources.  相似文献   
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Over forty-five complex free oligosaccharides (of which several are novel) have been isolated and chemically characterized by gas chromatography and high resolution and high mass accuracy matrix-assisted laser desorption/ionization mass spectrometry (MALDI-FTICR MS) in red and white wines, Grignolino and Chardonnay, respectively. Oligosaccharides with a degree of polymerization between 3 and 14 were separated from simple monosaccharides and disaccharides by solid-phase extraction. The concentrations of free oligosaccharides were over 100 mg/L in both red and white wines. The free oligosaccharides-characterized for the first time in the present study-include hexose-oligosaccharides, xyloglucans, and arabinogalactans and may be the natural byproduct of the degradation of cell wall polysaccharides. The coupled gas chromatography and accurate mass spectrometry approach revealed an effective method to characterize and quantify complex functional oligosaccharides in both red and white wine.  相似文献   
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The existence of genetic control over the abundance of particular taxa and the link of these to energy balance and growth has been documented in model organisms and humans as well as several livestock species. Preliminary evidence of the same mechanisms is currently under investigation in pigs. Future research should expand these results and elicit the extent of genetic control of the gut microbiome population in swine and its relationship with growth efficiency. The quest for a more efficient pig at the interface between the host and its metagenome rests on the central hypothesis that the gut microbiome is an essential component of the variability of growth in all living organisms. Swine do not escape this general rule, and the identification of the significance of the interaction between host and its gut microbiota in the growth process could be a game-changer in the achievement of sustainable and efficient lean meat production. Standard sampling protocols, sequencing techniques, bioinformatic pipelines and methods of analysis will be paramount for the portability of results across experiments and populations. Likewise, characterizing and accounting for temporal and spatial variability will be a necessary step if microbiome is to be utilized routinely as an aid to selection.  相似文献   
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Highly pathogenic avian influenza virus subtype H5N1 first entered Myanmar in 2006 in the Mandalay District. Several H5N1 outbreaks followed and the one of Bago East District (2007) required post outbreak surveillance in the at-risk domestic duck population of the Moyingyi Wetland. A field epidemiological study based on a randomised prospective stratified study with five surveys provided the serological evidence that the avian influenza H5 subtype circulates in the domestic duck population and spreads to almost all the newly housed (and negative) flocks in the time span of a seasonal production cycle. Virological investigation was negative. The survival analysis showed that the probability of seroconversion increased rapidly over the study period, without significant difference among different agro-ecosystems. The analysis suggests that viral spread in the new cycle could be limited if control measures were adopted at the time new flocks are housed. The study recommends that future surveillance schemes for ducks are designed in a way to get as much information as possible from serological results which should drive virological sampling to determined farms.  相似文献   
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This study focuses on the method for sperm extraction and artificial insemination in snakes. Ten adult healthy snakes (4.6) were included in the study (Pantherophis guttatus 1.3; Hydrodynastes gigas 1.1; Corallus hortulanus 1.1; and Sanzinia madagascariesis 1.1). Massage of the ventral aspect of the caudal third of the male snake body for 2 to 3 minutes was performed successfully for the semen collection. Both female and male P. guttatus and H. gigas were placed in brumation, with the female snakes being assessed for ovarian activity after emerging from dormancy. Only females showing ultrasonographic evidence of vitellogenic follicles were included in the study. S. madagascariensis and C. hortulanus were maintained at the same temperature through the year, and the ovarian activity was assessed ultrasonographically prior to artificially inseminating the animal. With the aid of a rigid endoscope, fresh semen was delivered through the cloaca and into the females’ oviducts using a catheter connected to the syringe. The technique failed in female S. madagascariensis and H. gigas. Two female P. guttatus laid eggs 2 months after artificial insemination, with hatchlings emerging following 2 months of development within the eggs. The third female corn snake did not lay an egg. The female C. hortulans produced eggs 4 months after insemination. The manual massage method of sperm collection in male snakes and endoscopy-assisted insemination in female snakes may be useful for conservation programs.  相似文献   
39.
The European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), is a well-known species that is cosmopolitan and present throughout Europe. Due to its omnivorous feeding behaviour, this species can act as a generalist predator, preying on several top fruit pests, but also as a pest causing shallow gouges or holes in stone and soft fruits such as apricots, strawberries, raspberries or blackberries. In Piedmont (NW Italy), significant fruit damage has been observed lately in apricot orchards where earwigs fed on ripening fruits and made a considerable part of the produce unmarketable. In this study, we sampled earwig populations in three apricot orchards in Piedmont and tested the effectiveness of glue barriers applied to the tree trunks in reducing both earwig density in the canopy and fruit damage. The arboreal glues Rampastop® and Vebicolla® were tested both in the field and laboratory trials. Glue barriers demonstrated to be effective control measures, significantly reducing earwig abundance in the canopy and fruit damage. Rampastop® gave better results on old trees with a very rough and cracked bark, since in that case Vebicolla® could not perfectly bond with the trunk.  相似文献   
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