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排序方式: 共有249条查询结果,搜索用时 15 毫秒
71.
Siracusa L Saija A Cristani M Cimino F D'Arrigo M Trombetta D Rao F Ruberto G 《Fitoterapia》2011,82(4):546-556
Three extracts of different polarities of Glycyrrhiza glabra L. leaves were characterized and evaluated for their antioxidant, anti-genotoxic and anti-inflammatory activity. In total, thirty components have been identified and quantified through the use of liquid chromatography (LC) with ultraviolet-visible diode-array-detector (UV-vis-DAD) and mass spectrometry (MS). The main components belong to the polyphenols family, being flavonoid and dihydrostilbene derivatives. The extracts have been investigated for their antioxidant, anti-genotoxic and anti-inflammatory activities, which are fundamental requirements of efficacious chemo-preventive agents. The ethyl acetate extract proved to be the most valuable, evidently for the conspicuous presence of several polyphenols, namely flavonoids and dihydrostilbenes. 相似文献
72.
Alla Shvaleva Filipe Costa e Silva Paula Scotti Mouhssin Oufir Jean-François Hausman Guignard Cedric Paula Ramos M. Helena Almeida M. Lucília Rodrigues João S. Pereira M. Manuela Chaves 《Annals of Forest Science》2008,65(2):204-204
We have compared the metabolic responses of leaves and roots of two Eucalyptus globulus L. clones CN5 and ST51 that differ in their sensitivity to water deficits (ST51 is more drought sensitive), with regard to the effect of chilling (10/5 °C, day/night). We studied changes in growth, osmotic potential and osmotically active compounds, soluble proteins, leaf pigments, and membrane lipid composition. Our data showed that both clones have the ability to acclimatize to chilling temperatures. As a result of 10 days of acclimation, an increase of soluble sugars in leaves of treated plants of both clones was observed that disappeared later on. Differences between clones were observed in the photosynthetic pigments and soluble protein content which were more stable in CN5 under chilling. It also was apparent that CN5 presented a less negative predawn water potential (ψpd) and a higher leaf turgor than ST51 throughout the chilling treatment. In the case of the CN5, increased total lipids (TEA) and concomitant increase of linolenic acid (C18:3) in leaves after acclimatization may be related to a better clone performance under chilling temperatures. Moreover, a higher constitutive investment in roots in the case of CN5 as compared to ST51 may benefit new root regeneration under low temperatures favoring growth after cold Mediterranean winter. 相似文献
73.
Manuela Panzacchi John D.C. Linnell Claudia Melis Morten Odden John Odden Lucrezia Gorini Reidar Andersen 《Forest Ecology and Management》2010
During the last century the boreal forests of south-eastern Norway have been converted into patchworks of agricultural areas, clear-cuts and even-aged conifer monocultures. Even though Scandinavian forest ecosystems are strongly influenced by small mammals’ dynamics, the effects of anthropogenic changes on these communities are still debated. We conducted an extensive capture–mark–recapture study to examine the relative abundance and distribution of 11 species of small mammals during the reproductive season with respect to all available landscape-scale habitat types and fine-scale vegetation characteristics. 相似文献
74.
Manuela S. Kaufmann Christian von Hebel Lutz Weihermüller Michael Baumecker Thomas Döring Kathlin Schweitzer Eleanor Hobley Sara L. Bauke Wulf Amelung Harry Vereecken Jan van der Kruk 《Soil Use and Management》2020,36(1):104-116
Electromagnetic induction (EMI) data are often used to investigate spatial and temporal patterns of soil texture, soil water content and soil salinity. We hypothesized that the EMI methodology might thus also offer potential to detect agricultural legacy effects originating from fertilizer application and irrigation of different fields. Therefore, we performed EMI measurements on two long-term field experiments (LTFE) at Thyrow near Berlin (Germany) that differed in agricultural management with regard to long-term irrigation in combination with mineral (NPK and lime) and organic amendments (straw and farmyard manure). Two different rigid-boom multi-coil EMI instruments were used to measure simultaneously the apparent electrical conductivity (ECa) over nine different depth ranges to study the entire soil profile from topsoil to deep subsoil. Additionally, soil samples were taken from the different treatments to ground-truth the measurements and disentangle the nutrient application or irrigation effects from natural soil heterogeneity. The soil samples indicated a rather homogenous soil and the correlation between soil parameters or states were not significant. However, the treatments showed significant differences in measured ECa values. In general, ECa values were largest on regularly irrigated as well as on mineral and organic fertilized plots, with regular irrigation exhibiting the largest impact on EMI records even though the last application was months before the EMI measurement. Overall, this study reveals that EMI data can support the classical in situ assessment of agricultural management effects within LTFE, while offering new potentials in detecting and understanding legacy effects of agricultural management on spatial soil properties at farm level. 相似文献
75.
Daniel Mageste de Almeida Marcos Inácio Marcondes Luciana Navajas Rennó Lívia Vieira de Barros Carla Heloísa Avelino Cabral Leandro Soares Martins David Esteban Contreras Marquez Felipe Vélez Saldarriaga Faider Alberto Castaño Villadiego Manuela Acevedo Cardozo Roman Maza Ortega Javier Enrique Garces Cardenas Virginia Lucia Neves Brandão Mário Fonseca Paulino 《Tropical animal health and production》2018,50(8):1771-1777
Beef cows’ milk yield is typically determined by measuring milk yield once daily and then doubling this value to estimate daily production. However, it is not known whether this is accurate. Thus, we aimed to determine the association between morning and afternoon milk yield in grazing Nellore cows. Eighty Nellore cows were used, with initial weight of 516.0?±?1.0 kg. The experiment was a completely randomized factorial scheme, with 20 replications and four treatments (i.e., +?or ??pre-partum supplementation in combination with +?or ??post-partum supplementation): PRMM—1 kg of supplement/cow/day for 90 days pre-partum; MMPS—1 kg of supplement/cow/day for 90 days post-partum; PRPS—1 kg of supplement/cow/day for 90 days pre-partum and 90 days post-partum; and MM—only mineral mix ad libitum during pre- and post-partum. Milk was sampled on days 45, 135, and 225 post-partum (early, middle, and late lactation, respectively). No effects were observed of pre- and post-partum supplementation on milk yield (P?>?0.05). The afternoon/morning proportion of 0.45 in the early third of lactation was higher than other stages, which had a proportion of 0.41 (P?<?0.05). Post-partum supplementation increased milk protein in the morning and afternoon milking (P?<?0.05). There was also no effect of pre- and post-partum supplementation on afternoon-morning proportion other milk components (P?>?0.05). We conclude that estimating daily milk production of grazing beef cattle by multiplying a once daily milking amount times two is not accurate. Under the conditions of this study, proportion of total daily production represented by the ratio of afternoon/morning milking was 0.45 in early lactation (first third) and 0.41 in mid- and late lactation. 相似文献
76.
Serological survey of Toxoplasma gondii infection in domestic cats from northeastern Portugal 总被引:1,自引:0,他引:1
Cats are very important hosts in the epidemiological cycle of Toxoplasma gondii, a zoonotic protozoan parasite that can infect humans and many other animal species worldwide. We report a serological survey of antibodies to T. gondii in domestic cats from northeastern Portugal, by means of the modified agglutination test. Three cats had titres of 20 (3.9%), 18 had titres of 40 (23.7%) and 55 animals had titres of > or =800 (72.4%). Results of three seropositive kittens with less than 4 months were not considered for determining the seroprevalence of infection, which was found to be 35.8% (73/204). Differences in the seroprevalence levels were not statistically significant between males (35.6%) and females (36.0%) or pure non-European (26.7%) and European or mixed-breed cats (39.6%). Animals aged 36-71 months and 72-180 months had the highest seroprevalences of infection, i.e. 51.7% and 51.2%, respectively, which significantly differ from the values observed in cats with 2-11 months (14.6%) and 12-35 months (26.3%). Infection levels were also significantly different between cats that lived totally indoors (7.7%) and those that had access to outdoors (45.4%), as well as between cats living alone (13.8%) and those that had contact with other cats (39.4%). Seroprevalence values in cats fed only commercial canned or dried food (22.9%) and animals whose diet included raw or undercooked viscera and/or meat (53.5%) were also significantly different. Furthermore, considering only 108 cats, differences of seropositivity to T. gondii were significant between feline immunodeficiency virus infected and non-infected animals, but this was not observed for feline leukaemia virus. Age, habitat and diet were identified as risk factors for the feline T. gondii infection by logistic regression analysis. Some control measures are suggested based on these findings. 相似文献
77.
Manuela Baumgarten Wendelin Weis Angelika Kühn Katharina May Rainer Matyssek 《European Journal of Forest Research》2014,133(4):677-690
The assessment of forest transpiration rates is crucial for determining plant-available soil water consumption and drought risk of trees. Xylem sap flux measurements have been used increasingly to quantify stand transpiration in forest ecosystems. Here, we compare this empirical approach with hydrological modeling on the basis of a stand transpiration dataset of adult beech (Fagus sylvatica), which was acquired across Bavaria, Germany, at eight forest sites. Xylem sap flux sensors were installed in five dominant trees each. Two tree to stand upscaling approaches, related to site-specific (1) sapwood area or (2) to leaf area index, were compared. The outcome was examined each in relation to process-based stand hydrological modeling, using LWF-BROOK90. Distinct relationships between tree diameter at breast height (1.30 m) and sapwood area-weighted sap flux along the radial profile became apparent across the study sites, confirming a generic allometric basis for stand-level upscaling of transpiration. The two upscaling approaches did not differ in outcome, representatively covering stand structure for comparison with modeling. Differential analysis yielded high agreement between the empirical and modeling approaches throughout most of the study period, although LWF-BROOK90 tended to overestimate sap flux measurements under low soil moisture. The two empirical approaches proved reliable for even-aged beech stands, as performance under high stand-structural heterogeneity awaits clarification. Findings advance stand-level hydrological modeling regarding coverage of stomatal behavior during temporary limitation in water availability. 相似文献
78.
The feeding preferences and consumption rates of the exotic woodlouse Armadillidium vulgare were measured on litters from the autochthonous Rio Grande cottonwood and the exotic Russian olive. When offered a choice between five litter types (green and shed leaves of Russian olive and cottonwood, and fruits of Russian olive), the isopods consumed more of the exotic plant litter (green leaves and the fruits of Russian olive) than of the autochthonous cottonwood. When offered only one diet, consumption rates of green leaves and fruits of Russian olive were again the highest. Feeding was related with N and C:N ratios of the litter, with highest consumption of diets with low and high C:N ratios and lowest consumption of diets with intermediate C:N ratios. The N content was highest (and C:N ratios lowest) on isopods feeding shed leaves of Russian olive. Growth was not related to the amount or the C:N ratio of the food consumed, being highest for animals feeding on shed leaves of cottonwood. Our results show that the consumption patterns and the C and N body composition of the exotic woodlouse A. vulgare are altered when fed with Russian olive litter, suggesting that the replacement of the autochthonous cottonwood by the exotic Russian olive may negatively affect the maintenance of the population of these exotic detritivores in the area. 相似文献
79.
Leilson O. Ribeiro Ricardo N. C. Pereira Renata V. Tonon Lourdes Maria C. Cabral Manuela Cristina P. A. Santiago António A. Vicente José António C. Teixeira Virgínia M. Matta Suely P. Freitas 《Plant foods for human nutrition (Dordrecht, Netherlands)》2018,73(1):68-73
This study aimed to recover bioactive compounds by solid-liquid extraction from the agro-industrial residue obtained during juçara fruits processing into pulp. A preliminary study using different solvents (methanol, ethanol and water) indicated ethanol in aqueous solution as the best solvent for antioxidants recovery. Then, a Box-Behnken design was applied considering as independent variables the solvent composition (30–70% ethanol in water), temperature (30–70 °C) and time (30–60 min), in order to evaluate the effects of these factors on antioxidant activity in juçara extract. Results showed that the extracts with higher antioxidant activity were obtained using 30% ethanol at 70 °C for 60 min; measurements included ABTS and DPPH assays, determination of total phenolic content and total monomeric anthocyanins. Furthermore, the effect of pH in antioxidants recovery was evaluated. For this purpose, the 30% ethanol solution was acidified to pH 1 and 2 with HCl. Principal component analysis showed the formation of three distinct groups: one characterized by high bioactive compounds content (pH 1.0), another with superior antioxidant activity (pH 5.75, non-acidified), and finally the group at pH 2 presenting the worst concentrations in the evaluated responses. HPLC analysis showed the presence of cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside in the extracts. Therefore, the conventional solid-liquid extraction using renewable solvent can be successfully applied to recover bioactive compounds from juçara residue, which can be used by different food industries. 相似文献
80.
Margarida Pestana Isabel M. de O. Abrantes Manuela Gouveia 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(2):283-292
The translocon-associated protein (TRAP) complex comprises four subunits (α, β, γ, δ) and is located in the endoplasmic reticulum membrane at translocation sites. The TRAP complex is required for the efficient translocation of substrates and to correct or eliminate misfolded proteins. In this study, we described the cloning and characterization of a cDNA encoding a TRAP from the phytoparasitic nematode Pratylenchus goodeyi (Pg). The full-length cDNA had an estimated size of 690 bp and encodes a 177 amino acid peptide. The deduced protein after sequence analysis codes for TRAPδ subunit homologous to TRAPδ from other nematodes. The Pg-TRAPδ had a signal peptide indicating a possible involvement in the transport and binding of other proteins at the endoplasmic reticulum membrane. The increase in relative expression of Pg-trapδ, assessed by semi-quantitative PCR, was induced over time in nematodes exposed to a nematostatic/nematicide extract of Solanum nigrum, suggesting that this gene product might be influenced by response mechanisms to stress in P. goodeyi. This is the first report of the cloning and characterization of trap cDNA from plant endoparasitic nematodes. 相似文献