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排序方式: 共有141条查询结果,搜索用时 15 毫秒
101.
Brito LF Barth AD Rawlings NC Wilde RE Crews DH Mir PS Kastelic JP 《Domestic animal endocrinology》2007,33(4):460-469
The objective of the present study was to evaluate the effects of improved nutrition during calfhood on serum metabolic hormones, gonadotropins and testosterone concentrations, and on sexual development in bulls. Bulls received high (n = 17) or control nutrition (n = 16) diets from 10 to 30 week of age and the same control nutrition diet from 31 to 74 week of age. Improved nutrition during calfhood resulted in a more sustained period of elevated LH secretion (pulse frequency and total secretion in 10 h) during the early gonadotropin rise. GnRH-stimulated LH secretion was not affected by diet, indicating that pituitary responsiveness was not altered; therefore, improved nutrition had direct effects on GnRH secretion by the hypothalamus. Insulin and insulin-like growth factor-I (IGF-I) concentrations were greater during calfhood in bulls receiving high nutrition, indicating that these metabolic hormones might be involved in regulating GnRH and LH secretion. Improved nutrition also resulted in increased testosterone secretion that was associated with greater circulating IGF-I concentrations, suggesting a role for this metabolic hormone in regulating Leydig cell number and function. Furthermore, improved nutrition during calfhood resulted in greater testicular weight and sperm production in mature bulls, indicating that increased LH secretion during calfhood, and increased IGF-I and testosterone concentrations during calfhood and peripubertal period were associated with greater testicular cell proliferation and enhanced function. 相似文献
102.
A greenhouse experiment was conducted to investigate the effects of different culture media on plantlet emergence, vegetative and generative traits of Marigold (Calendula officinalis) in randomized complete block design with ten treatments and three replications. The treatments were consisted of spent mushroom compost (SMC), alluvium soil (AS), garden soil (GS), SMC + AS (2:1), SMC + GS (2:1), SMC + AS (1:2), SMC + GS (1:2), AS + GS (2:1), GS + AS (2:1) and SMC + AS + GS (1:1:1). The results showed that application of SMC had positive effects on the vase life of flower and the number of days from the first bloom appearance. The vase life of flower was the highest (17.4 days) in the media containing SMC alone and the shortest (12.3 days) in media containing SMC + AS (1:2). However, mixture of SMC with AS or GS had significant positive effects on the evaluated traits. Generally, AS, SMC + AS or GS (2:1) and GS treatments had a better situation than other media. 相似文献
103.
Aitor?García-Tomillo José?Manuel?Mirás-AvalosEmail author Jorge?Dafonte-Dafonte Antonio?Paz-González 《Precision Agriculture》2017,18(5):882-897
Soil organic matter (SOM) is a key indicator of soil quality although, usually, detailed data for a given area is difficult to obtain at low cost. This study was conducted to evaluate the usefulness of soil apparent electrical conductivity (ECa), measured with an electromagnetic induction sensor, to improve the spatial estimation of SOM for site-specific soil management purposes. Apparent electrical conductivity was measured in a 10-ha prairie in NW Spain in November 2011. The ECa measurements were used to design a sampling scheme of 80 locations, at which soil samples were collected from 0 to 20 cm depth and from 20 cm to the boundary of the A horizon (ranging from 25 to 48 cm). The SOM values determined at the two depths considered were weighted to obtain the results for the entire A Horizon. SOM distribution maps were obtained by inverse distance weighting and geostatistical techniques: ordinary kriging (OK), cokriging (COK), regression kriging either with linear models (LM-RK) or with random forest (RF-RK). SOM ranged from 46.3 to 78.0 g kg?1, whereas ECa varied from 6.7 to 14.7 mS m?1. These two variables were significantly correlated (r = ?0.6, p < 0.05); hence, ECa was used as an ancillary variable for interpolating SOM. A strong spatial dependence was found for both SOM and ECa. The maps obtained exhibited a similar spatial pattern for SOM; COK maps did not show a significant improvement from OK predictions. However, RF-RK maps provided more accurate spatial estimates of SOM (error of predictions was between four and five times less than the other interpolators). This information is helpful for site-specific management purposes at this field. 相似文献
104.
Sara Sadat Aghabozorg Afjeh Jamal Shams Safar Hamednia Behzad Boshehri Asmaolhosna Amini Amin Omrani Mir Davood Omrani 《Iranian Biomedical Journal》2022,26(2):110
Background:Lithium is a therapeutic option for the treatment of the acute phase of the bipolar disorder and long-term management of this disorder. However, it is estimated that 10 to 60% of patients do not properly response to this medication.Methods:To investigate the role of MARK2 gene in response to lithium, we genotyped the MARK2 rs10792421 polymorphism in Iranian bipolar patients using ARMS-PCR.Results:Results of this study showed a significant association of this polymorphism with response to lithium. The A allele was more frequent in the responder than the non-responder group and also in the semi- responder group compared to the non-responder group in the codominant model of analysis. AA and AG genotypes were more frequent in both the responder and semi-responder groups compared to the non-responder group in dominant model of analysis.Conclusion:Based on the findings of the current study, the rs10792421 variant of MARK2 gene could be considered as a potential biomarker for predicting the treatment outcome of bipolar disorder type 1 in Iranian population. Key Words: Biomarkers, Bipolar, Lithium, Genotyping 相似文献
105.
Amita Mohan Pawan Kulwal Ravinder Singh Vinay Kumar Reyazul Rouf Mir Jitendra Kumar Manoj Prasad H. S. Balyan P. K. Gupta 《Euphytica》2009,168(3):319-329
A framework linkage map comprising 214 molecular marker (SSR, AFLP, SAMPL) loci was prepared using an intervarietal recombinant
inbred line (RIL) mapping population of bread wheat. The RIL population that was developed from the cross SPR8198 (red-grained
and PHS tolerant genotype) × HD2329 (white-grained and PHS susceptible genotype) following single seed descent segregated
for pre-harvest sprouting (PHS). The RIL population and parental genotypes were evaluated in six different environments and
the data on PHS were collected. Using the linkage map and PHS data, genome-wide single-locus and two-locus QTL analyses were
conducted for PHS tolerance (PHST). Single-locus analysis following composite interval mapping (CIM) detected a total of seven
QTL, located on specific arms of five different chromosome (1AS, 2AL, 2DL, 3AL and 3BL). These seven QTL included two major
QTL one each on 2AL and 3AL. Two of these seven QTL were also detected following two-locus analysis, which resolved a total
of four main-effect QTL (M-QTL), and 12 epistatic QTL (E-QTL), the latter involved in 7 QTL × QTL interactions. Interestingly,
none of these M-QTL and E-QTL detected by two-locus analysis was involved in Q × E and Q × Q × E interactions, supporting
the results of ANOVA, where genotype × environment interaction were non-significant. The QTL for PHS detected in the present
study may be efficiently utilized for marker-aided selection for enhancing PHST in bread wheat. 相似文献
106.
Antibacterial activity of immobilized silver nanoparticles on TEPA‐Den‐SiO2 against shrimp pathogen,Vibrio sp. Persian1
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Mehrdad Sarkheil Iman Sourinejad Maryam Mirbakhsh Davood Kordestani Seyed Ali Johari 《Aquaculture Research》2017,48(5):2120-2132
In this study, we prepared silver nanoparticles immobilized onto silica sand beads as an antibacterial material against pathogenic luminous Vibrio sp. Persian1. Silica beads were modified with 3‐aminopropyltriethoxysilane (APTES), cyanuric chlorid and tetraethylene pentamine, and silver nanoparticles were generated in various concentrations (0.5, 1, and 2 mM g?1 of silica beads) of AgNO3 on the surface using chemical reduction. Ag/TEPA‐Den‐SiO2 samples were characterized by TEM, FE‐SEM/EDS, FT‐IR and ICP OES and their antibacterial activity assayed by zone of inhibition and test tube tests against pathogenic Vibrio sp. The results of the zone inhibitory test revealed that all the Ag/TEPA‐Den‐SiO2 samples had an antibacterial effect against luminous Vibrio sp. Persian1. In addition, the tube test results showed 100% killing of bacteria in 2 h contact period. Ag/TEPA‐Den‐SiO2 samples maintained their antibacterial activity after 14‐day immersion in seawater by slow release of silver ions. These results suggest that Ag/TEPA‐Den‐SiO2 substrates could be effective antibacterial materials for disinfection of seawater used to culture Penaeid shrimp larvae. 相似文献
107.
Partial and total replacement of fish meal by marine microalga Spirulina platensis in the diet of Pacific white shrimp Litopenaeus vannamei: Growth,digestive enzyme activities,fatty acid composition and responses to ammonia and hypoxia stress
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Somayeh Pakravan Arash Akbarzadeh Mir Masoud Sajjadi Abdolmajid Hajimoradloo Farzaneh Noori 《Aquaculture Research》2017,48(11):5576-5586
In the this study, we evaluated the effect of replacement of fish meal by a marine microalgae Spirulina platensis on growth, digestive enzyme activities, fatty acid composition and responses to ammonia and hypoxia stress in Pacific white shrimp Litopenaeus vannamei (2.6 ± 0.2 g). Experimental diets contained S. platensis at 0%, 25%, 50%, 75% and 100% replacement levels. After 8 weeks of feeding trial, growth parameters and proximate body composition were not significantly different among treatments (p > .05). Amylase and lipase activities did not show any significant differences between control group and other experimental diets (p > .05), while activities of trypsin and chymotrypsin were significantly higher in shrimp fed diet with 50% substitution of microalgae compared to control group. Fatty acid contents, particularly polyunsaturated fatty acids (PUFAs) including arachidonic acid (ARA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), were significantly higher in control diet compared to other experimental diets. On the contrary, the majority of fatty acids including the contents of PUFAs in the whole body of L. vannamei fed with different levels of S. platensis were significantly higher compared to those of control group. After 48‐h exposure to ammonia, survival per cent was not statistically different between all groups (p > .05), but in hypoxia challenge, the survival per cent of control group was significantly less than that of treatments fed diets contained S. platensis (p < .05). Altogether, o ur results demonstrated the effectiveness of S. platensis as a reliable protein source for substitution of fish meal in shrimp aquaculture. 相似文献
108.
Agro-Morphological,Physico-Chemical and Molecular Characterization of Rice Germplasm with Similar Names of Bangladesh 总被引:1,自引:0,他引:1
Mir Sharf Uddin AHMED Mohammad KHALEQUZZAMAN Md.Khairul BASHAR Abul Kalam Mohammad SHAMSUDDIN 《水稻科学》2016,(4):211-218
Thirty-one duplicate and similar named rice germplasms of Bangladesh were studied to assess the genetic variation for the agro-morphological and physico-chemical traits and simple sequence repeat banding patterns during 2009–2012 at Bangladesh Rice Research Institute. The range of variations within the cultivar groups showed higher degree. The principal component analysis showed that the first five components with vector values 1 contributed 82.90% of the total variations. The cluster analysis grouped the genotypes into four clusters, where no duplicate germplasm was found. The highest number(11) of genotypes was constellated in cluster I and the lowest(3) in cluster II. The intra- and inter-cluster distances were the maximum in cluster I(0.93) and between clusters I and IV(24.61), respectively, and the minimum in cluster IV(0.62) and between clusters I and III(5.07), respectively. The cluster mean revealed that the crosses between the genotypes of cluster I with those of clusters II and IV would exhibit high heterosis for maximum good characters. A total of 350 alleles varied from 3(RM277) to 14(RM21) with an average of 7.8 per locus were detected at 45 microsatellite loci across the 31 rice accessions. The gene diversity ranged from 0.48 to 0.90 with an average of 0.77, and the polymorphism information content values from 0.44(RM133) to 0.89(RM206) with an average of 0.74. RM206, RM21, RM55, RM258 and RM433 were considered as the best markers on the basis of their higher polymorphism information content values. The dendrogram from unweighted pair-group method with arithmetic average clustering also classified the genotypes into four groups, where group IV comprised of 20 genotypes and group III of one genotype, but no duplicate was found. Finally, similar and duplicate named rice germplasms need to be conserved in gene bank as are distinct from each other. 相似文献
109.
J. Kumar V. Jaiswal A. KumarN. Kumar R.R. Mir S. KumarR. Dhariwal S. TyagiM. Khandelwal K.V. PrabhuR. Prasad H.S. BalyanP.K. Gupta 《Field Crops Research》2011,123(3):226-233
In bread wheat, high grain protein content (GPC) determines nutritional value, processing properties and quality of the end-product. In view of this, marker-assisted selection (MAS) was performed for introgression of a major gene for high GPC (Gpc-B1) into 10 wheat genotypes. As a result, 124 BC3F5/F6 progenies with Gpc-B1 were developed and evaluated in multi-location field trials. Significant interaction of Gpc-B1 with the recipient parent genotypes and the environment was noticed. However, a total of seven MAS-derived progenies with significantly higher GPC (14.83-17.85%) than their recipient parental genotypes and having no yield penalty were obtained. In these selected progenies, no significant negative correlation of grain yield with GPC (%) or protein yield was observed suggesting that GPC could be improved without yield penalty. This study thus suggested that MAS in combination with phenotypic selection is a useful strategy for development of wheat genotypes with high GPC associated with no loss in yield. 相似文献
110.