排序方式： 共有67条查询结果，搜索用时 203 毫秒
31.
M. A. Leal M. Joppert M. V. Licínio H. Evangelista J. Maldonado K. C. Dalia C. Lima C. V. Barros Leite S. M. Correa Geiza Medeiros K. Dias da Cunha 《Water, air, and soil pollution》2008,188(1-4):67-80
The aim of the present work is to characterize the local atmospheric emissions levels and compare them to the component derived from global pollution in a remote site at South Hemisphere (Admiralty Bay located at King George Island in Antarctic Peninsula). Airborne particles, snow and soil/sediments samples were analyzed. Local-produced atmospheric aerosol dispersion was estimated for metals originated by fossil fuel burning from the permanent scientific stations using a simplified Gaussian model. Validation of atmospheric dispersion was established by in situ measurements. Soluble and insoluble particles deposited in freshly snow and airborne particles were analyzed by PIXE (Particle Induced X-Ray Emission) for the determination of the elemental mass concentration and to obtain the Mass Median Aerodynamic Diameter (MMAD). The results showed significant correlation between the concentration of atmospheric aerosol and the freshly deposited particles in the snow, and permitted an estimate of the atmospheric snow deposition factor for K, Cu, Zn, Fe, Pb, and Ti. Results of long-term aerosol data compilation suggest that besides the local aerosol sources, the continental atmospheric transport of airborne particles is not significantly affected by the airborne particles produced by local human impacts at King George Island. 相似文献
32.
Oren Froy Noam Zilberberg Nor Chejanovsky Jacob Anglister Erwann Loret Boaz Shaanan Dalia Gordon Michael Gurevitz 《Pest management science》2000,56(5):472-474
Continued use of non‐specific chemical insecticides poses potential risks to the environment and to human health resulting from non‐target toxicity and increased insect resistance to these agents. Scorpions produce anti‐insect selective polypeptide toxins that bind to and modulate voltage‐sensitive ion channels in excitable tissues, thus offering alternative, environmentally safer means for insect pest control. Despite this potential, little is known about their structural elements dictating anti‐insect preference, which may be useful for the design of selective insecticides. We used a bacterial system for expression and genetic dissection of two pharmacologically distinct scorpion toxins: alpha and excitatory. By exploiting a multi‐disciplinary approach consisting of mutagenesis, protein chemistry, electrophysiology, binding and toxicity assays, and structural studies, we elucidated the bioactive surface of two anti‐insect toxins, LqhαIT and Bj‐xtrIT. In both polypeptides the bioactive surface is composed of residues surrounding the C‐terminal region. In addition, a direct, immediate approach in using the toxin genes was demonstrated by engineering baculoviruses with cDNAs encoding LqhIT2 (depressant toxin), and LqhIT1 (excitatory toxin) resulting in viral vectors with significantly improved insecticidal efficacy. © 2000 Society of Chemical Industry 相似文献
33.
Faisal Alsenani Ahmed M. Ashour Mubarak A. Alzubaidi Ahmed F. Azmy Mona H. Hetta Dalia H. Abu-Baih Mahmoud A. Elrehany Ahmed Zayed Ahmed M. Sayed Usama Ramadan Abdelmohsen Abeer H. Elmaidomy 《Marine drugs》2021,19(11)
Gnathonemuspetersii (F. Mormyridae) commonly known as Peters’ elephant-nose fish is a freshwater elephant fish native to West and Central African rivers. The present research aimed at metabolic profiling of its derived crude oil via GC-MS analysis. In addition, wound healing aptitude in adult male New Zealand Dutch strain albino rabbits along with isolated bioactive compounds in comparison with a commercial product (Mebo®). The molecular mechanism was studied through a number of in vitro investigations, i.e., radical scavenging and inhibition of COX enzymes, in addition to in silico molecular docking study. The results revealed a total of 35 identified (71.11%) compounds in the fish oil, belonging to fatty acids (59.57%), sterols (6.11%), and alkanes (5.43%). Phytochemical investigation of the crude oil afforded isolation of six compounds 1–6. Moreover, the crude oil showed significant in vitro hydrogen peroxide and superoxide radical scavenging activities. Furthermore, the crude oil along with one of its major components (compound 4) exhibited selective inhibitory activity towards COX-2 with IC50 values of 15.27 and 2.41 µM, respectively. Topical application of the crude oil on excision wounds showed a significant (p < 0.05) increase in the wound healing rate in comparison to the untreated and Mebo®-treated groups, where fish oil increased the TGF-β1 expression, down-regulated TNF-α, and IL-1β. Accordingly, Peters’ elephant-nose fish oil may be a potential alternative medication helping wound healing owing to its antioxidant and anti-inflammatory activities. 相似文献
34.
Gusella Giorgio Costanzo Mariangela Benedetta Aiello Dalia Polizzi Giancarlo 《European journal of plant pathology / European Foundation for Plant Pathology》2021,161(4):999-1005
Brachychiton species are planted in Italy as ornamental trees. A survey in a nursery in Sicily (Italy) revealed the presence of young B. acerifolius and B. populneus showing severe trunk cankers, massive gummosis from the bark cracks, wood discolouration, and twig dieback. Morphological characterization was based on conidia measurement, and molecular characterization was carried out performing phylogenetic analysis (Maximum Parsimony) based on multi-locus approach of partial ITS, EF-1α, and tub2. Identification of the causal agent resulted in Neofusicoccum parvum (Botryosphaeriaceae). Pathogenicity tests were conducted in order to fulfill the Koch’s postulates. Five and three-years-old potted Brachychiton plants were inoculated (indoor and outdoor) using mycelial plugs. All the inoculated plants showed severe symptoms similar of those observed in the nursery during the survey. Some of the inoculated plants were completely dead. Re-isolations fully confirmed the causal agent. For our knowledge, this is the first report worldwide of N. parvum attacking Brachychiton spp.
相似文献35.
Dalia A. Conde Fernando Colchero Heliot Zarza Joseph O. Sexton Cuauhtémoc Chávez Danae Azuara 《Biological conservation》2010,143(9):1980-1988
Competition for mates, cub rearing, and other behaviors differ between males and females in large carnivores. Although these differences can be reflected in patterns of habitat use, gender has rarely been incorporated into habitat models. We evaluated differences in habitat use between male and female jaguars in the Mayan Forest of the Yucatan Peninsula by modeling occupancy as a function of land cover type, distance to roads, and sex. Nested models were fitted to high-spatiotemporal resolution satellite (GPS) telemetry, controlled for temporal autocorrelation, and eliminated selection bias of pseudo-absences using a semi-non-parametric bootstrap. Although both male and female jaguars prefer tall forest, short forest was also preferred by females but avoided by males. Whereas females significantly avoided roads, males didn’t and ventured into low-intensity cattle ranching and agriculture. Females’ preference for intact forests and against roads led to their habitat being fragmented to a greater degree than that of males. Models that ignored sexual differences failed to capture the effect of roads and agriculture on jaguar habitat use, blurred the distinction of use between short and tall forest, and underestimated fragmentation of female jaguar habitat; but incorporating these differences increased precision of habitat maps and allowed the identification of potential jaguar-human conflict areas associated with male’s use of cattle and agricultural lands. Specifying sex differences increases the power of habitat models to understand landscape occupancy by large carnivores, and so greater attention should be paid to these differences in their modeling and conservation. 相似文献
36.
ABSTRACT: This study investigated the effect of conjugated linolenic acid (CLNA) on the growth and lipid composition of fingerling rainbow trout Oncorhynchus mykiss . Thirty individuals in each tank with three dietary treatments and duplicate groups were subjected to three dietary levels (0:4, 2:2, 4:0) of CLNA and linolenic acid (LNA) at 16°C in the laboratory for a period of 9 weeks. Punicic acid ( cis -9, trans -11, cis -13–18:3) and linseed oil were used as sources of CLNA and LNA, respectively. The hepatosomatic index and body lipid content of the 2% CLNA dietary treatment increased significantly ( P < 0.05) with respect to the control (LNA treatment). But the specific growth rate and percent gain did not improve significantly. After 6 weeks' observation, the 4% CLNA dietary treatment exhibited higher mortality and liver weight but lower weight gains (1.1–1.9 g). No significant differences were observed in the results of the feed efficiency and moisture as well as the protein content of the whole body among the treatments. Incorporation of CLNA into fish tissues was at a distinctly higher level in neutral lipids than in polar lipids. Increased levels of 22:6n-3 were found in the 4% CLNA treatment but decreased levels were found in the 2% CLNA treatment in both neutral and polar fractions. In the CLNA treatments, saturated fatty acid was relatively unaffected, the level of 18:1 was increased and the level of 18:2n-6 was decreased. These results indicate that the lower level (2%) of CLNA had no significant effect on the growth and the higher level (4%) of CLNA caused higher mortality as well as attenuating the growth of the fish. Dietary CLNA accumulated in a greater amount in the neutral lipids and modulated the fatty acid composition in the whole body of rainbow trout fingerlings. 相似文献
37.
Sophie Cornu Saskia Keesstra Antonio Bispo Maria Fantappie Fenny van Egmond Bozena Smreczak Rafał Wawer Lenka Pavlů Jaroslava Sobocká Zsófia Bakacsi Kinga Farkas-Iványi Sándor Molnár Anders Bjørn Møller Sevinc Madenoglu Dalia Feiziene Katrien Oorts Florian Schneider Maria da Conceição Gonçalves Raquel Mano Gina Garland Rastislav Skalský Lilian O'Sullivan Raimonds Kasparinskis Claire Chenu 《European Journal of Soil Science》2023,74(4):e13398
At the European scale, soil characteristics are needed to evaluate soil quality, soil health and soil-based ecosystem services in the context of the European Green Deal. While some soil databases exist at the European scale, a much larger wealth of data is present in individual European countries, allowing a more detailed soil assessment. There is thus an urgent and crucial need to combine these data at the European scale. In the frame of a large European Joint Programme on agricultural soils launched by the European Commission, a survey was conducted in the spring of 2020, in the 24 European participating countries to assess the existing soil data sources, focusing on agricultural soils. The survey will become a contribution to the European Soil Observatory, launched in December 2020, which aims to collect metadata of soil databases related to all kind of land uses, including forest and urban soils. Based upon a comprehensive questionnaire, 170 soil databases were identified at local, regional and national scales. Soil parameters were divided into five groups: (1) main soil parameters according to the Global Soil Map specifications; (2) other soil chemical parameters; (3) other physical parameters; (4) other pedological parameters; and (5) soil biological features. A classification based on the environmental zones of Europe was used to distinguish the climatic zones. This survey shows that while most of the main pedological and chemical parameters are included in more than 70% of the country soil databases, water content, contamination with organic pollutants, and biological parameters are the least frequently reported parameters. Such differences will have consequences when developing an EU policy on soil health as proposed under the EU soil strategy for 2023 and using the data to derive soil health indicators. Many differences in the methods used in collecting, preparing, and analysing the soils were found, thus requiring harmonization procedures and more cooperation among countries and with the EU to use the data at the European scale. In addition, choosing harmonized and useful interpretation and threshold values for EU soil indicators may be challenging due to the different methods used and the wide variety of soil land-use and climate combinations influencing possible thresholds. The temporal scale of the soil databases reported is also extremely wide, starting from the '20s of the 20th century. 相似文献
38.
Dhruv Aditya Srivastava Mariana Yakubov Reut Feldbaum Nimrod Tish Hagit Shoyhet Ekaterina Manasherova Eswari P. J. Pandaranayaka Dalia Rav-David Yigal Elad Arye Harel 《Phytoparasitica》2018,46(4):569-581
The necrotrophic fungus Botrytis cinerea, known as the causal agent of gray mold, is ranked second for its phytopathological global-impact. The disease is controlled by cultural means and fungicides, however, these techniques have variable effect on different fungal isolates due to the plasticity of the pathogen populations. Here we studied and characterized the genetic and virulence associated variability of B. cinerea isolates from different sources. Starting from initial survey of 31 B. cinerea isolates, collected from seven hosts in different locations of Israel, we have focused on 10 isolates that exhibited potential phytopathogenic variability. Two genetic markers (microsatellite) Bc1 and Bc7, were able to differentiate between these isolates. Our analysis demonstrates significant variability in saprophytic growth rate, necrotrophic growth rate on tomato leaves and stems, and in the incidence of infection on leaves of whole plants. Following the observation of significant correlation between saprophytic growth rate, and necrotrophic growth on leaves, we have studied normalized (by saprophytic growth) virulence. Utilization of normalized necrotrophic growth rate enabled to indicate on the presence of virulence mechanisms other than growth rate, for several isolates. Exploration of this direction illustrated variability in resistance to paraquat (associated with resistance to oxidation), which was associated with high and low superoxide dismutase (SOD) gene expression for selected isolates showing high or low paraquat resistance, respectively. Finally, we have used unsupervised learning (clustering analysis) to explore patterns in the multivariable space, which demonstrated two modes of pathogenicity in the tested B. cinerea isolates. 相似文献
39.
Rashad A. M. A. EL-Hedainy Dalia K. Mahdy A. E. Badran A. E. El-Barbary A. S. A. 《Tropical animal health and production》2019,51(8):2405-2412
Tropical Animal Health and Production - Carcass performance of 12 fattened male buffalo calves equally grouped by slaughter weights of 300, 350, 400, and 450 kg was evaluated. Six... 相似文献
40.
Michal Brand Yoel Messika Yigal Elad Dalia Rav David Abraham Sztejnberg 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(2):309-329
The effects of several spray and climate treatments on Leveillula taurica were tested under controlled and commercial greenhouse conditions either alone or combined with a climate treatment. Ampelomyces quisqualis AQ10 inhibited the germination of conidia on leaves, but not on glass. Trichoderma harzianum T39 inhibited germination on both surfaces. Neither the examined biological control agents (BCAs) nor the two tested mineral
oils (AddQ and JMS Stylet-Oil) affected the viability of conidia. Sulphur drastically limited the germination and viability
of L. taurica. In experiments at 15–25°C, AQ10 alone reduced hyphal leaf colonisation at 25°C. T. harzianum T39 significantly reduced leaf colonisation at all temperatures but significantly reduced disease only at 20–25°C. The oils
significantly reduced leaf colonisation and sulphur reduced both leaf colonisation and disease at all temperatures. Results
were confirmed in an experimental greenhouse. In a field experiment, azoxystrobin, polyoxin AL, neem extract, and T39 were
effective; sulphur was superior to them. Under severe epidemic conditions the disease had a negative impact on yield; late
fungicide treatments at spring-time were found unnecessary. Chemical sprays applied in alternation was compared with the ‘friendly’
spray regime (alternation of Heliosoufre, T. harzianum T39 + JMS Stylet oil, A. quisqualis AQ10+AddQ oil and Neemgard) in two climates i.e. (i.) day warm climate and (ii.) regular (cool) day climate regimes. In the
warm climate, there was no significant difference in the performance of the ‘friendly’ spray regime and the chemical spray
regime. However, in the cooler climate, the ‘friendly’ spray programme was not as effective as the chemical spray programme.
It was concluded that a change in the greenhouse climate may affect the development of powdery mildew and, at the same time,
promote the activity of BCAs and render a pathogen more vulnerable to these control agents, allowing for better disease suppression. 相似文献