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961.
962.
M. G. Pleskacheva Z. A. Zorina 《Journal of Evolutionary Biochemistry and Physiology》2012,48(5-6):548-567
There has been compared behavior of rats, corvid birds, and monkeys of different species at their performance of the Revecz-Krushinskii test (RKT) developed by L.V. Krushinskii to estimate the human capability for revealing rule of discrete translocation of hidden target object. RKT was introduced as an addition to the test for extrapolation of the movement direction of the lure seen only at the initial pathway fragment; this test is close to Piaget’s test (stage 6) evaluating the capability for mental representation and location of the moving hidden object. During RKT, the lure, hidden from animals, was placed, near where it was previous time: at the first test presentation—under the 1st cylinder, at the 2nd one—under the 2nd cylinder, etc. The animals were tested once. It was shown that they did not catch the necessary for successful solution rule of the lure translocation, direction and step of its translocation at each presentation. Only some of the animals solved RKT, found the lure 3 and more times in succession with no errors or with one error. Nevertheless, in all groups the number of errors was lower than that in the model situation of random search. Such optimization was a consequence of universal for all groups’ strategy of search in the places where the lure was found recently. With the similar number of errors, rats, birds, and monkeys performed the search differently. Rats were looking for lure mainly among the cylinders where they had found it previously, whereas monkeys and birds the first the new cylinders located near the target one, which implies the existence, to the weak extent, of elements of prognosis. For all groups of animals, RKT turned out to be more difficult both of the test for extrapolation and of the Piaget’s test. 相似文献
963.
Huiskonen JT Kivelä HM Bamford DH Butcher SJ 《Nature structural & molecular biology》2004,11(9):850-856
Biological membranes are notoriously resistant to structural analysis. Excellent candidates to tackle this problem in situ are membrane-containing viruses where the membrane is constrained by an icosahedral capsid. Cryo-EM and image reconstruction of bacteriophage PM2 revealed a membrane bilayer following the internal surface of the capsid. The viral genome closely interacts with the inner leaflet. The capsid, at a resolution of 8.4 A, reveals 200 trimeric capsomers with a pseudo T = 21 dextro organization. Pentameric receptor-binding spikes protrude from the surface. It is evident from the structure that the PM2 membrane has at least two important roles in the life cycle. First, it acts as a scaffold to nucleate capsid assembly. Second, after host recognition, it fuses with the host outer membrane to promote genome entry. The structure also sheds light on how the viral supercoiled circular double-stranded DNA genome might be packaged and released. 相似文献
964.
Qiu YC Zhou RH Kong XY Zhang SS Jia JZ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(8):1524-1531
A powdery mildew resistance gene from Triticum urartu Tum. accession UR206 was successfully transferred into hexaploid wheat (Triticum aestivum L.) through crossing and backcrossing. The F1 plants, which had 28 chromosomes and an average of 5.32 bivalents and 17.36 univalents in meiotic pollen mother cells (PMC),
were obtained through embryos rescued owing to shriveling of endosperm in hybrid seed of cross Chinese Spring (CS) × UR206.
Hybrid seeds were produced through backcrossing F1 with common wheat parents. The derivative lines had normal chromosome numbers and powdery mildew resistance similar to the
donor UR206, indicating that the powdery mildew resistance gene originating from T. urartu accession UR206 was successfully transferred and expressed in a hexaploid wheat background. Genetic analysis indicated that
a single dominant gene controlled the powdery mildew resistance at the seedling stage. To map and tag the powdery mildew resistance
gene, 143 F2 individuals derived from a cross UR206 × UR203 were used to construct a linkage map. The resistant gene was mapped on the
chromosome 7AL based on the mapped microsatellite makers. The map spanned 52.1 cM and the order of these microsatellite loci
agreed well with the established microsatellite map of chromosome arm 7AL. The resistance gene was flanked by the microsatellite
loci Xwmc273 and Xpsp3003, with the genetic distances of 2.2 cM and 3.8 cM, respectively. On the basis of the origin and chromosomal location of the
gene, it was temporarily designated PmU. 相似文献
965.
The severity of a root rot disease of cereals, caused by Rhizoctonia solani Kühn AG8, was inversely correlated to the Zn status of plants in field studies in 1989 and 1990. In 1989, a preliminary survey was conducted in a farmer's field in South Australia where Zn deficiency and disease were both widespread. Zn concentration in Spear wheat plants at the 3-leaf to early tillering stage was negatively correlated with severity of the disease. For the elevent elements analysed, a correlation matrix showed that Zn had the highest, and only significant (R2=0.52**) association with disease. The effect of Zn applications and their residual value on disease severity was further studied in a long-term field experiment in 1989 and 1990 to which Zn had been applied in 1986. There was a decrease in the area of Rhizoctonia bare patch as Zn rate was increased, a result consistent with the field survey results; the recommended rate of 2.5 kg Zn ha–1 reduced the area affected by bare patch from 42% to 21% of the total crop area compared with no Zn application, overcame Zn deficiency and increased grain yield from 1.1 to 2.8 t ha–1. In 1990, fresh Zn application treatments were applied to trial plots designed for this purpose, in order to compare the response with the older Zn treatments applied in 1986. The areas of bare patch in the older Zn treatments were approximately 5% greater than those in the fresh Zn treatments. The results are consistent with the hypothesis that Zn deficient plants are more susceptible to root rot caused by R. solani. Testing this hypothesis is the subject of a companion paper. 相似文献
966.
遥感数据支持下不同地表覆盖的区域蒸散 总被引:11,自引:0,他引:11
将地表能量平衡系统(SEBS)扩展成遥感日蒸散估算模型,利用MODIS遥感数据估算了黄淮海地区的区域蒸散,并在地理信息系统的支持下分析了不同地表覆盖下的区域蒸散统计分布特征.在缺乏各地表覆盖类型相应蒸散量实测值进行对比的情况下,以2001年4月17日估算的日蒸散量为例,通过各地表覆盖类型日蒸散量间的相互对比分析表明,SEBS估算的区域日蒸散量具有一定的合理性.分析结果表明:在黄淮海地区,荒地具有最低的蒸散量;森林、灌木、草地等地表覆盖类型具有中等的蒸散量;而水体、湿地以及耕地具有较高的蒸散量.可能由于包含绿地和水面,城镇用地的蒸散量也较高.土壤含水量的空间差异性导致森林、灌木、草地和耕地等地表覆盖类型的蒸散量具有明显的空间差异性.耕地蒸散量的空间差异性可以为制定合理、高效的农田灌溉计划提供指示作用.SEBS遥感日蒸散模型的局限性在于有可能低估水体和湿地等地表覆盖类型的蒸散量. 相似文献
967.
Krzyzanowska K Mittermayer F Krugluger W Kopp HP Schernthaner G 《Obesity (Silver Spring, Md.)》2006,14(11):1886-1889
Objective: The recently described adipokine visfatin is produced in visceral fat and has been suggested to influence insulin resistance. To investigate whether visfatin concentrations are related to changes in body weight, this adipokine was measured in insulin‐resistant severely obese patients before and after gastroplastic surgery. Research Methods and Procedures: Visfatin, interleukin‐6, high‐sensitivity C‐reactive protein, homeostasis model assessment of insulin resistance (HOMA‐IR), and other clinical parameters were assessed in 36 severely obese subjects (28 female; mean age, 43 years) with a median BMI of 44.3 kg/m2 (95% confidence interval, 43.3 to 48.1 kg/m2). Results: After surgery, BMI decreased to a median of 31.9 kg/m2 (30.1 to 35.1 kg/m2) (p < 0.0001). Median visfatin concentrations increased significantly after weight loss [70.9 ng/mL (61.4 to 75.6 ng/mL) vs. 86.4 ng/mL (79.4 to 89.8 ng/mL); p < 0.0005]. This increase correlated with the decrease of insulin and HOMA‐IR and was associated with a reduction in plasma interleukin‐6 and high‐sensitivity C‐reactive protein concentrations. Discussion: Massive weight loss after gastroplastic surgery is accompanied by an increase in circulating concentrations of the novel adipokine visfatin. This increase correlates with the decrease in plasma insulin concentrations and HOMA‐IR. 相似文献
968.
Playing with bone and fat 总被引:15,自引:0,他引:15
Gimble JM Zvonic S Floyd ZE Kassem M Nuttall ME 《Journal of cellular biochemistry》2006,98(2):251-266
The relationship between bone and fat formation within the bone marrow microenvironment is complex and remains an area of active investigation. Classical in vitro and in vivo studies strongly support an inverse relationship between the commitment of bone marrow-derived mesenchymal stem cells or stromal cells to the adipocyte and osteoblast lineage pathways. In this review, we focus on the recent literature exploring the mechanisms underlying these differentiation events and discuss their implications relevant to osteoporosis and regenerative medicine. 相似文献
969.
Yang Z. T. Lu D. X. Hong E.-K. Zhang B. Y. Jiang M. C. Yang Y. J. Zhang D. J. 《Molecular Biology》2020,54(6):911-918
Molecular Biology - Brassica campestris L. is the important oil-bearing crop in China. Rapeseed cake is the main byproduct of rapeseed oil extraction. As the main active ingredient in rapeseed... 相似文献
970.