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排序方式: 共有438条查询结果,搜索用时 15 毫秒
21.
Javier Bezos Sergio Marqués Julio Álvarez Carmen Casal Beatriz Romero Ana Grau Olga Mínguez Lucas Domínguez Lucía de Juan 《Research in veterinary science》2014
Goats can act as reservoirs for tuberculosis (TB) infection. The main etiological agents of TB in goats are Mycobacterium caprae and Mycobacterium bovis and they infect also a wide range of domestic and wild animals and humans. Control programmes based mainly on the application of single and comparative intradermal tuberculin (SIT and SCIT respectively) tests are being implemented in certain regions of Spain with a high density of caprine flocks as Castilla y León, including goats with epidemiological relationship with cattle. The aim of this study was to evaluate the performance of the intradermal tests in naturally TB-infected caprine flocks from this region. The study was performed using data from 17,450 goats in 54 different flocks that were classified as TB-infected in the control programmes executed in 2010 and 2011. Data from 1237 goats from 7 dairy flocks depopulated after the first intradermal testing were used to estimate the sensitivity (Se) using bacteriology as the gold-standard. Overall Se of the SIT test using the severe interpretation was 43.9% (CI 95%, 40.4–47.4) and decreased to 38.8% (CI 95%, 35.5–42.3) using the standard interpretation. Overall Se of the SCIT test ranged between 21.3% (CI 95%, 17.6–25.4) and 7% (CI 95%, 4.9–9.8) depending of the interpretation criteria. A significant weak positive correlation was found between age and skin fold thickness (Spearman’s test p < 0.05). Results from this study yielded, in general, low Se values probably due the systematic detection and slaughter of reactors as a consequence of the eradication programme in previous years or the presence of factors that may interfere in the diagnosis. Therefore, these results suggest the necessity of including ancillary diagnostic tools and/or strict interpretation criteria to maximize detection of positive animals in infected settings. 相似文献
22.
Ortega Jaime Díaz Sedov Sergey Romero Francisco Jardines Luis Gerardo Martínez Rebolledo Elizabeth Solleiro 《Journal of Soils and Sediments》2022,22(3):942-956
Journal of Soils and Sediments - The objective of this study was to examine the pedogenetic evolution occurring in technic hard materials from an iron mine through the characterization of a... 相似文献
23.
Intraspecific olive diversity assessed with AFLP 总被引:6,自引:0,他引:6
F. Sanz-Cortés D. E. Parfitt C. Romero D. Struss G. Llacer M. L. Badenes 《Plant Breeding》2003,122(2):173-177
Amplified fragment length polymorphism (AFLP) was used to study diversity within and among Spanish olive varieties. A high degree of diversity was found among the varieties present in each growing region. Olive oil production and quality relies on appropriate cultivar selection as well as good orchard management. Production based only on a few superior cultivars would result in improved yield, oil quality, and production management. Amplified fragment length polymorphism were evaluated as a tool to identify the intraspecific and intravarietal diversity of olive. Amplified fragment length polymorphism analysis of 38 accessions belonging to 10 cultivars using six primer combinations produced 106 polymorphic bands. Results were analyzed for similarity among accessions via unweighted pair‐group means cluster analysis, resulting in 10 clusters corresponding to named variety designations. Similarity among varieties ranged from 0.60 to 0.72. Diversity within varieties was identified. Similarity within named varieties (accessions with the same varietal name) ranged from 0.75 to 0.96. Differences in several markers were found among 34 accessions. Intravarietal diversity was shown to exist within the Spanish olive varieties grown in the region surrounding Valencia. 相似文献
24.
To verify the compatibility behaviour of the almond cultivar ‘Francolí’ and to clarify its S genotype a combination of pollination tests, stylar ribonuclease and allele specific PCR analysis was used. ‘Francolí’ was released from IRTA's breeding programme in 1994, having been putatively raised from the cross ‘Cristomorto’ (S1S2) × ‘Gabaix’ (S10S25). This cultivar was also reported to be self‐incompatible but revealing only one S band in the zymograms after S‐RNases analysis. ‘Francolí’ sets nuts after test crossing with two S1S25 cultivars, having a different genotype from that earlier reported. ‘Francolí’ was also observed to be self‐compatible after selfing flowers in the field and in the laboratory. ‘Francolí’ was re‐assigned the S1Sf genotype after test crossing, stylar ribonuclease and PCR data analysis. After microsatellite analysis, the self‐compatible ‘Tuono’ (S1Sf) cultivar is suggested as the male parent of ‘Francolí’ instead of the earlier reported ‘Gabaix’. 相似文献
25.
Summary None of the tested cultivars of lettuce was found resistant to Stemphylium leaf spot, a common disease in Israel. Within a Lactuca saligna population collected in wild lettuce in Israel, resistance was traced. Interspecific crosses of L. saligna x L. sativa were made and the mode of inheritance of resistance to this disease was studied. Resistance is apparently controlled by two genes: one dominant (Sm1) and one recessive (sm2).Contribution No. 1176-E 1984 series, from the ARO. 相似文献
26.
An incubation experiment was conducted to evaluate the ameliorating role of two organic amendments—olive-mill solid wastes and compost from olive-mill solid wastes- in the ecological reclamation of a lead/Zn-mine tailing collected in southern Spain. Four enzymatic activities (dehydrogenase, β-glucosidase, urease and phosphatase) and soluble and AB-DTPA extractable Pb and Zn and were periodically determined. High concentrations of Pb (5394 mg kg?1) and Zn (9607 mg kg?1), mainly in insoluble forms, were recorded in the lead/zinc-mine tailing, as well as very low biochemical activity. Application of the compost from olive-mill solid waste stimulated microbial activity and the biogeochemical cycles into the mine tailing because of the initially increased dehydrogenase, β-glucosidase and urease activities, which tended to decline or remained constant during the incubation period. By contrast, these enzyme activities were scarcely affected by the incorporation of the olive-mill solid wastes because this olive-organic amendment contains extractable polyphenols (36 g kg?1), which inhibit these enzyme activities. Phosphatase activity was enhanced by the application of both olive-organic amendments, especially when the olive-mill solid waste was added to the mine tailing. Amounts of soluble and AB-DTPA-extractable Pb and Zn in the mine tailing were increased by the application of the olive-mill solid waste, and to a lesser degree, by the compost from this olive waste. This fact could restrict the use of these olive-organic amendements as useful materials in reclamation of lead/zinc-mine tailings. Nevertheless, the increases of available lead and zinc would represent an advantage where Pb/Zn-mine tailings are reclaimed by phytoextraction, effectively reducing the metal pollution in these mining wastes. 相似文献
27.
Romero MP Tovar MJ Girona J Motilva MJ 《Journal of agricultural and food chemistry》2002,50(19):5349-5354
The HPLC phenolic profile of virgin olive oils obtained from young olive trees (Arbequina cv.) grown under different deficit irrigation strategies was studied. Deficit irrigation (RDI) did not affect all the phenolic compounds in the same way. Lignans, vanillic acid, vanillin, and the unknown phenolic compound named P24 increased in the oils from the most irrigated treatments. The secoiridoid derivatives and the unknown phenolic compound named P19 increased in the oils from the most stressed irrigation treatments. The period of growth where a water stress significantly affects the phenolic profile of oils was between pit hardening and the first stages of fruit growth and oil accumulation, independently of the water applied during the previous period to harvest. The phenolic profile and those parameters related to phenol content, oxidative stability, and the bitter index were significantly affected only in the most severe RDI strategies. Other strategies produced important savings in irrigation requirements and an increase in the water use efficiency without noticeably affecting the phenolic profile. 相似文献
28.
Coffee agroecosystem performance under full sun, shade, conventional and organic management regimes in Central America 总被引:1,自引:0,他引:1
J. Haggar M. Barrios M. Bola?os M. Merlo P. Moraga R. Munguia A. Ponce S. Romero G. Soto C. Staver E. de M. F. Virginio 《Agroforestry Systems》2011,82(3):285-301
Changes in coffee economics are leading producers to reduce agrochemical use and increase the use of shade. Research is needed on how to balance the competition from shade trees with the provision of ecological services to the coffee. In 2000, long-term coffee experiments were established in Costa Rica and Nicaragua to compare coffee agroecosystem performance under full sun, legume and non-legume shade types, and intensive and moderate conventional and organic inputs. Coffee yield from intensive organic production was not significantly different from intensive conventional in Nicaragua, but in Costa Rica it was lower during three of the six harvests. Full sun coffee production over 6 years was greater than shaded coffee in Costa Rica (61.8 vs. 44.7 t ha?1, P = 0.0002). In Nicaragua, full sun coffee production over 5 years (32.1 t ha?1) was equal to coffee with shade that included Tabebuia rosea (Bertol.) DC., (27?C30 t ha?1) and both were more productive (P = 0.03) than coffee shaded with Inga laurina (Sw.) Willd. (21.6 t ha?1). Moderate input organic production was significantly lower than other managements under all shade types, except in the presence of Erythrina poepiggina (Walp.) O.F. Cook. Inga and Erythrina had greater basal area and nutrient recycling from prunings than other shade species. Intensive organic production increased soil pH and P, and had higher K compared to moderate conventional. Although legume shade trees potentially provide ecological services to associated coffee, this depends on management of the competition from those same trees. 相似文献
29.
Total pollution indexes for measuring heavy metal contamination of industrialized areas may be quickly estimated from selected metal partial indexes for soil (M-SPI) or plants (M-PPI). Partial pollution indexes for plants (or soils) are calculated by the formula M-PPI (or M-SPI) = 100 (I ? I unp)/(I tox ?I unp), where I = c i 1/ni is the ionic impulsion of the selected metal M, with oxidation number n i, for its actual plant (or soil) concentration c i,and I unp and I tox, the ionic impulsions for unpolluted and toxid levels of the M in plants (or soils). The total pollution indexes were proposed by analogous formulae containing the sums of contributions of metals accumulated in roots (Pb, Cd, Co, Cr, Ni, Cu, Zn and also Fe for plants), without participation of macroconstituents (K, Mg, Ca, Na, and also Mn), accumulated in plant tops. Partial pollution indexes may also serve to show (i) deficiency or toxicity levels of plants (or soils) and (ii) associations between pollutants, easily detected by a numerical taxonomy's dendrogram. Using correlation coefficient techniques for the Bilbao (Spain) model zone, the total soil pollution index, SPI, may be calculated from Zn-SPI, Pb-SPI, Cu-SPI or Cu-PPI. The total plant pollution index, PPI, is similarly related to Fe-PPI or Zn-PPI, though some distortion is evident when the sampling point is close to specific industrial factories. The best estimation (without distortion) for monitoring total plant pollution index is based on the sum of contributions of essential elements (Fe, Cu, and Zn). This fact suggests the existence of defense mechanisms of plants for balancing both the uptake of toxic metals and deficiencies of essential constituents. Finally total pollution indexes may be used for the estimation of the number of pollutants with toxic levels in plants or soils. 相似文献
30.
The aim of the present work was to determine the influence of different CaCl(2) dosages on foliar biomass and quality of tobacco plants (Nicotiana tabacum L. var. Tennesse 86). Plants were grown under controlled conditions and submitted to regular fertilization with macro- and micronutrients. The CaCl(2) was applied to the nutrient solution at 1.25 mM (T1), 2.5 mM (T2), and 5 mM (T3). The results indicated that, under the experimental conditions of this work, the application of 1.25 mM of CaCl(2) favored the growth and development of the leaves, this leading to improved biomass production in tobacco leaves. The increase in foliar biomass in treatment T1 could largely be a result of the stimulation of NO(3)(-) assimilation. However, this situation has negative consequences for tobacco quality, given that the T1 treatment augmented the NO(3)(-) concentration and the foliar concentration of nicotine (both effects being harmful for human consumption) and decreased the concentration of reducing sugars in leaves of tobacco plants compared with those of T2 and T3. Finally, a close and directly proportional relationship was found in our experiment between the parameters of foliar-biomass production, total N concentration, chlorophyll concentration, and decline in quality. 相似文献