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排序方式: 共有406条查询结果,搜索用时 15 毫秒
101.
J. de Oliveira Peixoto S.E. Facioni Guimarães P. Sávio Lopes M.A. Menck Soares A. Vieira Pires M.V. Gualberto Barbosa R. de Almeida Torres & M. de Almeida e Silva 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2006,123(6):378-383
The associations of leptin (LEP) gene polymorphisms C798T, T2411C, T3266G and T3469C with production traits were investigated in a F2 pig population produced by divergent crosses. The statistical model included genotype, sex, batch and genotype by sex interaction as fixed effects and sire as random effect. Polymorphism C798T was associated with variation in total teat number (p < 0.02) and left teat number (p < 0.03), and polymorphism T3469C was associated with weight at 21 days (p < 0.03), 42 days (p < 0.05), 63 days (p < 0.02) and 77 days of age (p < 0.04) as well as feed intake (p < 0.01), average daily gain (p < 0.01), feed conversion (p < 0.01), bacon depth (p < 0.03) and slaughter weight (p < 0.03). Phenotypic associations were also performed by combining T3469C and C798T genotypes. Interaction between C798T genotypes and sex was observed for some traits. LEP genotypes had significant influence on performance traits, and can be considered as potential genetic markers for selection. However, these results have to be validated in commercial herds. 相似文献
102.
Phytochemicals endowed with hormonal, antihormonal, or toxic activity are potential agents for insect control. The effect of some neolignans on one of the most prevalent flies in urban areas, which constitutes a menace to public health, was investigated. 相似文献
103.
Albin Lobo Jon Kehlet Hansen Lea Vig McKinney Lene Rostgaard Nielsen Erik Dahl Kjær 《Scandinavian Journal of Forest Research》2014,29(6):519-526
The invasive fungal pathogen, Hymenoscyphus pseudoalbidus V. Queloz, has decimated stands of Fraxinus excelsior L. over most of the species' natural distribution area. We assessed crown damage from 2009 to 2014 (at ages 8, 11 and 13) in 43 open-pollinated ash families planted in north-eastern Zealand, Denmark, and confirmed the presence of substantial genetic variation in ash dieback susceptibility. The average crown damage increased in the trial from 61% in 2009 to 66% in 2012 and 72% in 2014, while the estimated heritability was 0.42 in both 2009 and 2012 but increased to 0.53 in 2014. Genetic correlation between assessments was 0.88 between 2009 and 2012 and 0.91 between 2009 and 2014, suggesting fairly good possibilities for early selection of superior genotypes in the presence of high infection levels in the trial. The level of crown damage had strong negative effect on growth and survival. Only 34% of the trees with high levels of damage in 2009 were still alive in 2014, emphasising that high susceptibility is associated with low fitness. 相似文献
104.
José D. Barbosa Jenevaldo B. da Silva Charles P. Rangel Adivaldo H. da Fonseca Natália S. Silva Henrique A. Bomjardim Nayra F. Q. R. Freitas 《Tropical animal health and production》2014,46(3):513-517
The prevalence of and possible risk factors for tuberculosis were studied in water buffalo from Pará, Brazil. In this study, 3,917 pregnant and nonpregnant female Murrah and Mediterranean buffaloes were studied; 2,089 originated from Marajó Island, and 1,108 were from the mainland. The comparative cervical tuberculin test was used as a diagnostic test for tuberculosis in these animals. The prevalence of positive buffaloes was 3.5 % (100/2,809) on Marajó Island and 7.2 % (80/1,108) on the mainland. The municipalities with the highest tuberculosis prevalence rates in animals were Ipixuna do Pará (10.1 %), Marapanim (9.8 %), Chaves (9.4 %), Paragominas (8.6 %), and Cachoeira do Arari (6.7 %). The tuberculosis prevalence was not significantly different between the Murrah (4.3 %) and Mediterranean (4.8 %) breeds or between pregnant (5 %) and nonpregnant (4.3 %) buffaloes. Tuberculosis was detected in water buffaloes from Pará, Brazil; the mainland buffalo exhibited the highest tuberculosis prevalence. These results indicate that this disease is dangerous to public health and buffalo farming in Pará. 相似文献
105.
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107.
Lobo RF Pan M Chan I Li HX Medrud RC Zones SI Crozier PA Davis ME 《Science (New York, N.Y.)》1993,262(5139):1543-1546
The framework structures of two closely related molecular sieves, SSZ-26 and SSZ-33, are described. These materials possess a previously missing but desired structural feature in a group of industrially significant zeolites. They contain a three-dimensional pore system that provides access to the crystal interior through both 10- and 12-rings. This property is a consequence of the organic structure-directing agents used in the synthesis of these materials. These materials are examples of the purposeful design of a micropore architecture. Both SSZ-26 and SSZ-33 contain the 4=4-1 building unit that had been previously found only in natural zeolites. 相似文献
108.
Alatalo RV Aragón S Avilés JM Barbosa A Gomes CB Cadée N Christe P Cuervo JJ Díaz M Erritzøe J Galeotti P Garamszegi LZ Gil D Gontard-Danek M Legendre S Martin TE Martínez J Martín-Vivaldi M Martínez JG Merino S Moreno J Mousseau T Ninni P Petrie M Pulido F Rubolini D Saino N Soler JJ Soler M Spottiswoode C Szép T Thornhill R Zamora C Sacchi R 《Science (New York, N.Y.)》2004,303(5664):1612
109.
Utilizing newly assembled data on per capita metropolitan investments from the Census of Governments - Finance Statistics, this paper assesses the effects of local (i.e., non-state and non-federal) government investments in public capital on metropolitan factor productivity. Differences in productivity across metropolitan areas are modeled as a Hicks-neutral production function shifter, and the analysis covers 261 metropolitan areas of the United States for the period 1977 to 1992. These findings indicate that there is no significant relationship between levels of public capital investments and the levels of metropolitan productivity for the periods 1977, 1982, 1987, and 1992; however, a positive and significant relationship is found between the growth rate of local government investments in public capital and the growth rate of metropolitan productivity for the fifteen-year period. 相似文献
110.
Molecular mapping and identification of QTL's associated to oat crown rust partial resistance 总被引:1,自引:0,他引:1
Marta M. Barbosa Luiz C. Federizzi Sandra C. K. Milach José A. Martinelli Gladis C. Thomé 《Euphytica》2006,150(1-2):257-269
Summary Molecular mapping is a promising strategy for studying and understanding traits with complex genetic control, such as partial resistance to oat crown rust. The objectives of this research were to develop molecular maps from the progenies of the cross UFRGS7 (susceptible) × UFRGS910906 (partially resistant) and to identify QTLs (quantitative trait loci) associated to partial resistance to oat crown rust in two generations of that population.DNA of 86 genotypes of the F2 and 90 genotypes of the F6 UFRGS7 × UFRGS910906 population were used to generate AFLP markers. Molecular maps were constructed using Mapmaker Exp. 3.0 and QTLs for partial resistance to oat crown rust were identified with Mapmaker/QTL software. Five hundred and fifty seven markers in the F2 and 243 markers in the F6 generations were identified. The F2 map integrated 250 markers in 37 linkage groups. The F6 map integrated 86 markers in 17 linkage groups.Five QTLs were identified for partial resistance to oat crown rust in the F2 generation and three QTLs in the F6. The QTL identified on F6 through the PaaaMctt340 AFLP marker showed consistency across two environments and two generations (F4 and F6), and appear to have potential for marker-assisted selection in oat. 相似文献