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We consider family specific fitnesses that depend on mixed strategies of two basic phenotypes or behaviours. Pairwise interactions are assumed, but they are restricted to occur between sibs. To study the change in frequency of a rare mutant allele, we consider two different forms of weak selection, one applied through small differences in genotypic values determining individual mixed strategies, the other through small differences in viabilities according to the behaviours chosen by interacting sibs. Under these two specific forms of weak selection, we deduce conditions for initial increase in frequency of a rare mutant allele for autosomal genes in the partial selfing model as well as autosomal and sex-linked genes in the partial sib-mating model with selection before mating or selection after mating. With small differences in mixed strategies, we show that conditions for protection of a mutant allele are tantamount to conditions for initial increase in frequency obtained in additive kin selection models. With particular reference to altruism versus selfishness, we provide explicit ranges of values for the selfing or sib-mating rate based on a fixed cost-benefit ratio and the dominance scheme that allow the spreading of a rare mutant allele into the population. This study confirms that more inbreeding does not necessarily promote the evolution of altruism. Under the hypothesis of small differences in viabilities, the situation is much more intricate unless an additive model is assumed. In general however, conditions for initial increase in frequency of a mutant allele can be obtained in terms of fitness effects that depend on the genotypes of interacting individuals or their mates and generalized conditional coefficients of relatedness according to the inbreeding condition of the interacting individuals.  相似文献   

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We report on a 12-year-old boy with a supernumerary chromosome der(21)t(7; 21)(p21; q21.3)mat, resulting in a partial trisomy 21 and a partial trisomy 7p. The patient has a severe psychomotor retardation. Although he has most of chromosome 21 in three copies, he does not have a phenotype of Down syndrome (DS). In addition to cytogenetic analysis, molecular analysis confirmed that the "DS critical region" on chromosome 21 (21q22) is not present in three copies, since the breakpoint of the partial trisomy 21 was found to be located distal to the marker locus D21S145 but proximal to D21S226. The patient's severe mental retardation is probably due to the small telomeric 7p trisomy, having the breakpoint between markers D7S507 and D7S488. In comparison with previously published cases of partial trisomy 7p, the phenotype of this patient indicates that there is a region around the distal part of band 7p21 that in three copies might contribute to many of the facial features common to patients with partial trisomy 7p.  相似文献   

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A series of phenoxyacetic acids as subtype selective and potent hPPARδ partial agonists is described. Many analogues were readily accessible via a single solution-phase synthetic route which resulted in the rapid identification of key structure-activity relationships (SAR), and the discovery of two potent exemplars which were further evaluated in vivo. Details of the SAR, optimization, and in vivo efficacy of this series are presented herein.  相似文献   

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Gibberellin A13 7-aldehyde, previously proposed as an intermediate in the fungal biosynthesis of gibberellin A3, has been prepared from gibbere  相似文献   

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Sun Y  Deng X  Li W  Yan Y  Wei H  Jiang Y  He F 《Proteomics》2007,7(23):4398-4407
The extraordinary ability of the liver to regenerate after resection continues to be an important fascination to mammalian liver researchers. However, at present, there are still several central questions regarding the process of liver regeneration that are not clear. In our study, we try to clarify how the liver is able to maintain its functions as well as to initiate liver regeneration after a significant loss of two-thirds. Here differentially expressed proteins in rat livers at 1 h after partial hepatectomy (PHx) and sham operation were analyzed using 2-DE combined with MALDI-TOF/TOF MS. After the analysis, 24 significantly changed spots (ratio> or =2, p<0.05) were identified. Those proteins are involved in important liver functions such as metabolism, detoxification, and inflammation. Based on the changes in the protein levels found in our data, we identified two aspects of remnant liver immediately after PHx, which focused on the hepatic adaptation and the inflammatory response associated with the initiation of liver regeneration after PHx. For the first time, the differential expression of pyruvate dehydrogenase complex (PDHX), paraoxonase 1 (PON1), thyroid hormone receptor beta, GAP43 (where GAP stands for growth-associated protein), and interleukin-2 (IL2), after PHx, were validated by Western blot.  相似文献   

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We report clinical observations and cytogenetic studies of an inherited partial trisomy 8q and partial monosomy 18p. A full trisomy 8 syndrome (Warkany syndrome) is a clinically recognized syndrome. Partial trisomy 8q has been reported sporadically in the literature with variable phenotypes. Partial monosomy 18p, deletion of the short arm of chromosome 18, is also a well-recognized syndrome. This is the first report to the best of our knowledge of partial trisomy for distal 8q and partial monosomy for distal 18p occurring together in a patient.  相似文献   

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Summary Partial denervation of the sternocostalis muscle was achieved by sectioning two out of five of its intercostal nerves. The terminal sprouting response was markedly increased compared to that found following section of only one nerve. The increase in the response was greater for B type than for C type end plates, although B type end plates appear unable to produce terminal sprouts longer than 20 m after partial denervation.Double nerve section allowed terminal sprouts from C type end plates to increase in length up to three days, after which time they appeared to retract. It is postulated that the onset of collateral sprouting resulted in reinnervation of empty end plate sites and hence removed the target for terminal sprouts.  相似文献   

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《遗传学报》2014,41(11):591-599
Partial amphiploids created by crossing common wheat (Triticum aestivum L.) and Thinopyrum ponticum (Podp.) Barkworth & D. R. Dewey are important intermediates in wheat breeding because of their resistance to major wheat diseases. In this study, we examined the chromosome compositions of five Xiaoyan-series wheat−Th. ponticum partial amphiploids (Xiaoyan 68, Xiaoyan 693, Xiaoyan 784, Xiaoyan 7430, and Xiaoyan 7631) using GISH, multicolor-GISH, and multicolor-FISH. We found several chromosome changes in these lines. For example, wheat chromosomes 1B and 2B were added in Xiaoyan 68 and Xiaoyan 7430, respectively, while wheat chromosome 6B was eliminated from Xiaoyan 693 and Xiaoyan 7631. Chromosome rearrangements were also detected in these amphiploids, including an interspecific translocation involving chromosome 4D and some intergenomic translocations, such as A–B and A–D translocations, among wheat genomes. Analysis of the Th. ponticum chromosomes in the amphiploids showed that some lines shared the same alien chromosomes. We also evaluated these partial amphiploids for resistance to nine races of stem rust, including TTKSK (commonly known as Ug99). Three lines, Xiaoyan 68, Xiaoyan 784, and Xiaoyan 7430, exhibited excellent resistance to all nine races, and could therefore be valuable sources of stem rust resistance in wheat breeding.  相似文献   

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Heterogeneity in susceptibility and infectivity is inherent to infectious disease transmission in nature. Here we are concerned with the formulation of mathematical models that capture the essence of heterogeneity while keeping a simple structure suitable of analytical treatment. We explore the consequences of host heterogeneity in the susceptibility to infection for epidemiological models for which immunity conferred by infection is partially protective, known as susceptible-infected-recovered-infected (SIRI) models. We analyze the impact of heterogeneity on disease prevalence and contrast the susceptibility profiles of the subpopulations at risk for primary infection and reinfection. We present a systematic study in the case of two frailty groups.We predict that the average rate of reinfection may be higher than the average rate of primary infection, which may seem paradoxical given that primary infection induces life-long partial protection. Infection generates a selection mechanism whereby fit individuals remain in S and frail individuals are transferred to R. If this effect is strong enough we have a scenario where, on average, the rate of reinfection is higher than the rate of primary infection even though each individual has a risk reduction following primary infection. This mechanism may explain high rates of tuberculosis reinfection recently reported.Finally, the enhanced benefits of vaccination strategies that target the high-risk groups are quantified.  相似文献   

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This paper presents the family of a dysmorphic child with the phenotypic features of Turner's syndrome and 5q trisomy, whose parents are both carriers of a balanced translocation. The parents' karyotypes are 46,X,t(X;5)(p11.1;q31) and 45,XY,der(13;14)(q10;q10), respectively.  相似文献   

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At present, the parents are included in the experimental material for judging the performance of crosses over parents and for calculation of heterosis but they are ignored for combining ability analysis of Partial Diallel Crosses due to the non-availability of the method of analysis for such designs. To satisfy the practical need of the breeders on one hand and to remove the statistical objections on the other hand, a method of analysis of Partial Diallel Crosses based on circulant sample including parents has been presented in this paper. A numerical example is given for llustration of technique.  相似文献   

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目的:评价经腹腔入路与后腹腔入路两种途径腹腔镜肾部分切除术治疗T1a期肾癌的技术特点及临床效果。方法:回顾性比较分析35例经腹腔入路(A组)与33例后腹腔入路03组)腹腔镜肾部分切除术治疗T1a期肾癌患者的临床资料,对两组肿瘤大小、标本重量、性别、年龄、手术时间、术中出血量、热缺血时间、术后肠功能恢复时间、术后住院天数、围手术期并发症等指标进行对比研究。两组共68例患者均获得随访,比较两种术式的肿瘤学效果。结果:两组在肿瘤大小、标本重量、性别、年龄、手术时间、术中出血量、热缺血时间、围手术期并发症发生率、术后无瘤生存率等方面均无明显差异(p〉0.05);B组在术后肠功能恢复时间及术后住院天数小于A组(P〈0.05)。结论:对于治疗T1a期肾癌,两种途径的腹腔镜手术效果相似。后腹腔入路腹腔镜肾部分切除术对肠道干扰少,可缩短术后肠功能恢复时间及术后住院天数。本中心采用”三步走”方法-剪刀剪除肿瘤、双极电凝止血、Hem-0-lok结扎夹辅助8字缝合,安全、高效、可靠。肌苷、廿露醇及利尿荆使用可减少缺血再灌注损伤,操护肾功能。  相似文献   

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While β-boswellic acid is very readily available by extraction from frankincense resin, the accessibility of α-boswellic from the resin involved great effort and tedious purification procedures. Alternatively, a partial synthesis from readily available oleanolic acid was developed, the key steps of which are a reduction of the carboxyl group C-28 furnishing a methyl group, followed by palladium-assisted oxidation of the methyl group C-24, and configurational inversion at C-3.  相似文献   

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Thresholds in transmission are responsible for critical changes in infectious disease epidemiology. The epidemic threshold indicates whether infection invades a totally susceptible population. The reinfection threshold indicates whether self-sustained transmission occurs in a population that has developed a degree of partial immunity to the pathogen (by previous infection or vaccination). In models that combine susceptible and partially immune individuals, the reinfection threshold is technically not a bifurcation of equilibria as correctly pointed out by Breban and Blower. However, we show that a branch of equilibria to a reinfection submodel bifurcates from the disease-free equilibrium as transmission crosses this threshold. Consequently, the full model indicates that levels of infection increase by two orders of magnitude and the effect of mass vaccination becomes negligible as transmission increases across the reinfection threshold.  相似文献   

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