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151.
Resistance to anticoagulant rodenticides in brown rats (Rattus norvegicus Berk.) is associated with pleiotropic effects, notably with an increased dietary vitamin K requirement. Owing to this disadvantage, resistance is believed to be selected against if anticoagulant selection is absent. In small experimental populations of wild brown rats, an investigation was carried out to establish whether tolerance to anticoagulant exposure changed over a period of 2 years. In the same populations, DNA microsatellite markers were used to infer parentage, and this made it possible to estimate reproductive success of sensitive and resistant rats and estimate effective population size, Ne. Even though there was evidence for a selection against resistant rats with high vitamin K requirement, anticoagulant tolerance was not seen to be significantly influenced in the absence of bromadiolone selection. As the population size under investigation was small, random genetic drift may have played a role in this. In the presence of bromadiolone selection, however, the tolerance was significantly increased, suggesting that continuous selection will increase the proportion of highly resistant rats in the population. It was found that, for both males and females, surprisingly few individuals contributed to the next generation with numerous offspring, and most breeders contributed with none or a single offspring. The expected higher reproductive success and consequent increase in proportional numbers of sensitive rats in the absence of anticoagulant selection could not be observed. Among the resistant rats, moderately resistant females were found to be better breeders than highly resistant breeders, but for resistant males the reverse was true. This could be explained by the fact that the increased vitamin K requirement results in sex differential selection; in highly resistant males the selection presumably takes place at the immature stage, whereas in females the vitamin K requirement becomes crucial at the reproductive stage, as vitamin K is not only essential for the blood clotting process but also for bone formation. 相似文献
152.
Sundekilde UK Barile D Meyrand M Poulsen NA Larsen LB Lebrilla CB German JB Bertram HC 《Journal of agricultural and food chemistry》2012,60(24):6188-6196
Free oligosaccharides are key components of human milk and play multiple roles in the health of the neonate, by stimulating growth of selected beneficial bacteria in the gut, participating in development of the brain, and exerting antipathogenic activity. However, the concentration of oligosaccharides is low in mature bovine milk, normally used for infant formula, compared with both human colostrum and mature human milk. Characterization of bovine milk oligosaccharides in different breeds is crucial for the identification of viable sources for oligosaccharide purification. An improved source of oligosaccharides can lead to infant formula with improved oligosaccharide functionality. In the present study we have analyzed milk oligosaccharides by high-performance liquid chromatography chip quadrupole time-of-flight mass spectrometry and performed a detailed data analysis using both univariate and multivariate methods. Both statistical tools revealed several differences in oligosaccharide profiles between milk samples from the two Danish breeds, Jersey and Holstein-Friesians. Jersey milk contained higher relative amounts of both sialylated and the more complex neutral fucosylated oligosaccharides, while the Holstein-Friesian milk had higher abundance of smaller and simpler neutral oligosaccharides. The statistical analyses revealed that Jersey milk contains levels of fucosylated oligosaccharides significantly higher than that of Holstein-Friesian milk. Jersey milk also possesses oligosaccharides with a higher degree of complexity and functional residues (fucose and sialic acid), suggesting it may therefore offer advantages in term of a wider array of bioactivities. 相似文献
153.
McKenzie F. Johnson Nina Kanderian Christopher C. Shank Haqiq Rahmani David Lawson Peter Smallwood 《Biological conservation》2012,148(1):146-155
Planning for protected area networks is often done on an ad hoc basis, especially in data-poor countries. Afghanistan, a country mired in conflict for the past 30 years, has little of the relevant data to plan a protected area network, and security concerns hinder collection of new data. However, conservation of Afghanistan’s natural resources will be critical to recovery efforts. To assist Afghanistan in planning for its protected area network, we conducted an analysis to identify ecologically important areas for conservation. We overlaid data from ecoregion, floral, and faunal analyses on a grid map of Afghanistan (313 cells each 2500 km2), and used a ranking system to determine those cells containing diverse and/or threatened ecosystems. A color gradation was applied to each cell (white – least diverse to black – most diverse) to produce a map visually depicting ecological diversity across Afghanistan. Those cells with the highest scores were labeled as Priority Zones – defined as areas in which Afghanistan should prioritize conservation activities for protected area designation. Our results formed the basis of the National Protected Area System Plan of Afghanistan, a document setting quantitative protected area targets and outlining a concrete plan of action for the designation of a protected area network. We found the Priority Zone model to be useful in helping Government partners locate areas potentially important for conservation and prioritize activities for protected area designation. This process may be useful for other conflict or post-conflict countries working to establish protected area networks in a data deficient environment. 相似文献
154.
Benny De Cauwer Nina Biesemans Sander De Ryck Lieven Delanote Karel Dewaele Koen Willekens Thijs Vanden Nest Dirk Reheul 《Weed Research》2021,61(1):55-67
Galinsoga quadriradiata and Galinsoga parviflora are very troublesome weeds in many organic vegetable crops in Europe. A very straightforward method to keep Galinsoga infestations under control is by targeting the Galinsoga seedbank. To identify cropping systems able to reduce the seedbank size in vegetable‐based cropping systems, the relationships between the seedbank size of Galinsoga species and prevailing soil/crop management practices and pedo‐hydrological conditions were investigated. Hereto, the seedbank of the 0–20 cm topsoil layer was sampled in 50 organic vegetable fields and analysed according to the seedling emergence method. Field history data were collected for the past 5 years, and physical, chemical and microbial soil quality was determined. Galinsoga quadriradiata was the most frequent and abundant Galinsoga species in the weed seedbank. The genus Galinsoga was present in 90% of the soil weed seedbanks of organic vegetable fields but displayed wide variation in abundance. Smallest Galinsoga seedbanks were found in fields that were predominantly tilled with non‐inversion implements or rotationally ploughed, and continuously cropped with competitive crops during the entire growing season (April 15‐November 15). Contrary to G. quadriradiata, seedbank size of G. parviflora was closely related to soil organic carbon content and sand fraction. Remarkably, soils with a low level of easily plant‐available phosphorus and concomitant high activity of arbuscular mycorrhizae had smaller G. quadriradiata seedbanks. To reduce Galinsoga infestations, fields should preferably be tilled without soil inversion, fertilised with organic amendments with low content of readily plant‐available phosphorus and cropped with competitive crops all season long. 相似文献
155.
Jevtić Radivoje Skenderović Nina Župunski Vesna Lalošević Mirjana Orbović Branka Maširević Stevan Bagi Ferenc 《植物病害和植物保护杂志》2021,128(4):1013-1022
Journal of Plant Diseases and Protection - The influence of abiotic and biotic factors on yield loss has usually been analysed separately without considering their interactions. Consequently, the... 相似文献
156.
为鉴定广东水松的遗传多样性,应用改良 CTAB 法分别提取广东不同地区的孑遗植物水松基因组 DNA,以真核生物 rDNA ITS 序列的通用引物分别对其 ITS 区进行 PCR 扩增及测序后进行比对、分析,将得到的序列申请登录入 GenBank 核苷酸数据库。结果表明:广东地区不同来源水松的 rDNA ITS 序列长度均为988 bp,相互之间仅有2~3个碱基差异,说明该序列可作为从分子水平鉴别水松种质资源的参考标记。珠海、中山和广州地区孑遗植物水松 GenBank 核苷酸数据库登录号分别是 KF977874、KF977876和 KF977875。 相似文献
157.
Rosenblat M Volkova N Coleman R Aviram M 《Journal of agricultural and food chemistry》2006,54(5):1928-1935
The effects of a pomegranate byproduct (PBP, which includes the whole pomegranate fruit left after juice preparation) on atherosclerosis development in apolipoprotein E-deficient (E degrees ) mice were studied. Consumption of PBP (17 or 51.5 microg of gallic acid equiv/kg/day) by the mice resulted in a significant reduction in atherosclerotic lesion size by up to 57%. PBP consumption significantly reduced oxidative stress in the mice peritoneal macrophages (MPM): Cellular lipid peroxide content decreased by up to 42%, the reduced glutathione levels increased by up to 53%, and paraoxonase 2 lactonase activity increased by up to 50%, as compared to MPM from E degrees mice that consumed only water. Furthermore, oxidized low-density lipoprotein (Ox-LDL) uptake by the MPM was reduced by up to 19%. Similar results were observed also in vitro. Treatment of J774A.1 macrophages with PBP (10 or 50 micromol/L of total polyphenols) significantly decreased both cellular total peroxide content and Ox-LDL uptake. It was thus concluded that PBP significantly attenuates atherosclerosis development by its antioxidant properties. 相似文献
158.
Risk assessment of herbicides towards non-target plants in Europe is currently based solely on tests on algae and floating aquatic plants of Lemna sp. Effects on terrestrial non-target species is not systematically addressed. The purpose of the present study was to compare combination effects of herbicide mixtures across aquatic and terrestrial test systems, and to test whether results obtained in the traditional aquatic test systems can be extrapolated to the terrestrial environment. This was done by evaluating ten binary mixtures of nine herbicides representing the seven most commonly used molecular target sites for controlling broadleaved weeds. Data were evaluated statistically in relation to the concentration addition model, and for selected concentrations to the independent action model. The mixtures were tested on the terrestrial species Tripleurospermum inodorum (L.) Schultz-Bip. (Scentless Mayweed) and Stellaria media (L.) Vill. (Common Chickweed), and on the aquatic species Lemna minor L. (Lesser duckweed) and the alga Pseudokirchneriella subcapitata (Korschikov) Hindak. For the two mixtures of herbicides with the same molecular site of action, the joint effect was additive. For the eight mixtures of herbicides with different sites of action, two of the mixtures were consistently antagonistic across species, while for the remaining six mixtures the joint effect depended on the species tested. This dependence was, however, not systematic, in the sense that none of the species or test systems (terrestrial versus aquatic) had a significantly higher probability of showing synergistic or antagonistic joint effects than others. Synergistic interactions were not observed, but approximately 70% of the mixtures of herbicides with different sites of action showed significant antagonism. Hence, the concentration addition model can be used to estimate worst-case effects of mixtures of herbicides on both terrestrial and aquatic species. Comparing the sensitivity of the species to a 10% spray drift event showed that the terrestrial species were more vulnerable to all herbicides compared with the aquatic species, emphasising the importance of including terrestrial non-target plants in herbicide risk assessment. 相似文献
159.
Schmid T Weishaupt MA Meyer SW Waldern N Peinen Kv Nuss K 《Veterinary journal (London, England : 1997)》2009,181(2):151-157
To evaluate the manner in which a cow's claws make contact with the ground at the walk, the gait, and in particular the claw-ground contact pattern, were studied in 12 healthy, lactating dairy cows, using high-speed cinematography (500frames/s) while the animals were walking on a treadmill. The results showed that the limbs were advanced around the contralateral limbs in a sigmoid curve. The feet contacted the ground with the foot axis and the tips of the claws rotated slightly outwards. In all cows the lateral claws contacted the ground before the medial claws in the hindlimbs, and in 10/12 cows in the forelimbs. The heel of the lateral claws was the region of initial contact with the ground in the hindlimbs of all cows and in the forelimbs in 9/12 cows. Lateral 'heel first' contact in the fore and hindlimbs appeared to be the normal gait pattern in these animals. Compared with a previous study of heifers, lactating cows had a larger step width in the hindlimbs and a smaller step width in the forelimbs. These ground contact patterns offer an explanation for the predisposition to claw disorders of the lateral claw of the hindlimb. The results of this study reinforce the suggestion that soft floor surfaces should be provided for cattle to prevent mechanical injury to the claws. 相似文献
160.
Imboden I Waldern NM Wiestner T Lischer CJ Ueltschi G Weishaupt MA 《Veterinary journal (London, England : 1997)》2009,179(1):50-59
Extracorporeal shock wave therapy (ESWT) is an accepted form of treatment for chronic cases of proximal suspensory desmitis (PSD). Subjective evaluation of horses shortly after being treated with ESWT has led clinicians to comment on an immediate reduction in lameness. This study aimed to evaluate the analgesic effect of ESWT on 16 horses with PSD or PSD-like pain in a fore- or hindlimb. To objectively assess lameness, gait analysis was performed on an instrumented treadmill before and 6, 24, 48 and 72h after ESWT of the origin of the suspensory ligament and the results compared to the effects of local anaesthesia. Stride frequency, stance duration, vertical impulse and peak vertical force were determined. Thermographic imaging and evaluation of skin sensitivity of the treated area were carried out before and after ESWT in the same interval as gait analysis. The results showed that there were no significant improvements in the investigated parameters at any time after ESWT; however, in horses with affected forelimbs the contralateral weightbearing asymmetry decreased significantly 72h after ESWT. Neither skin sensitivity nor thermographic imaging revealed changes that could be attributed to ESWT. 相似文献