This article proposes that the ’imāla phenomenon was an innovation in the Najd region. The non-’imāla form was the traditional form because it is the vowel production in the available Ancient North Arabian data. The article will separate the use of ’imāla as an assimilatory vowel from the Najdi non-assimilatory production by analyzing the testimonial data in the traditional books of grammar. Finally, the article will use the available genealogical literature to establish an approximate chronology for the innovation and to justify the spread of the innovation among the pre-Islamic tribes.
A product is referred to as robust when its performance is consistent. In current product robustness paradigms, robustness is the responsibility of engineering design. Drawings and 3D models should be released to manufacturing after applying all the possible robust design principles. But there are no methods referred for manufacturing to carry and improve product robustness after the design freeze. This paper proposes a process of inducing product robustness at all stages of product development from design release to the start of mass production. A manufacturing strategy of absorbing all obvious variations and an approach of turning variations to cancel one another are defined. Verified the application feasibility and established the robustness quantification method at each stage. The theoretical and actual sensitivity of different parameters is identified as indicators. Theoretical and actual performance variation and accuracy of estimation are established as robustness metric. Manufacturing plan alignment to design, complimenting the design and process sensitivities, countering process mean shifts with tool deviations, higher adjustable assembly tools are enablers to achieve product robustness.
Different chromosomal forms of Deschampsia antarctica Desv. (Poaceae), including diploids (2n=26), hypotriploid (2n=36–38) and a genotype with an occasional occurrence of B chromosome (2n=26+0-1B) that originated from southern marginal populations (Argentine Islands region, maritime Antarctic) were studied using molecular cytogenetic, morphometric and biochemical methods. FISH analysis revealed variations in the number of rDNA sites between the diploid and hypotriploid plants. The genome size varied among plants with a different chromosome number and was on average 10.88 pg/2C for diploids and 16.46 pg/2C for hypotriploid. The mean values of leaf length of plants grown in vitro varied within a range of 5.23–9.56 cm. The total phenolic content ranged from 51.10 to 105.40 mg/g, and the total flavonoid content ranged from 1.22 to 4.67 mg/g. The amount of phenolic compounds did not differ significantly between the genotypes, while a variation in the flavonoid content was observed for L59 and DAR12. The diploids did not differ significantly among each other in terms of the number of rDNA loci, but differed slightly in their genome size. The individuals of DAR12 carrying B chromosome were similar to other diploids in terms of their genome size, but statistically differed in leaf length. The hypotriploid had both a greater number of rDNA sites and a larger genome size. No statistical correlations were observed between the genome size and leaf length or genome size and accumulation of phenolic and flavonoid compounds. The results of this study suggest that D. antarctica plants from the southern edge of the range are characterised by the heterogeneity of the studied parameters.
This communication reports detection of somaclonal variation among tissue culture-raised plants of Amorphophallus rivieri Durieu, an economically important crop in China, with high content of glucomannan in its corms. A population of regenerated plants was obtained from a single donor plant of A. rivieri via corm organogenesis, and 28 plants were randomly selected as a representative sample and subjected to analysis of somaclonal variation using inter-simple sequence repeat (ISSR) markers. Of the 26 ISSR primers screened, 13 gave distinct and reproducible band patterns, yielding 131 bands with an average of 10.1 bands per primer. Ten primers were polymorphic and generated 16 polymorphic bands with 12.2% mean polymorphism. Based on the ISSR data from the regenerated plants and the donor plant, Jaccard's similarity coefficients were calculated; they ranged from 0.961 to 1.000 with a mean of 0.982. A dendrogram was constructed using the unweighted pair group method with arithmetic mean (Upgma); it showed that a majority of regenerated plants (including the donor plant) clustered closely, with a mean similarity coefficient of 0.987. Low somaclonal variation observed in the regenerated plants indicates that rapid propagation of A. rivieri via corm organogenesis is a practicable method with a low risk of genetic instability.
The present report describes the new occurrence of Tomato mosaic virus (ToMV) in cabbage, bean and Malva neglecta plants in Iran. In this study, sequence analyses of a partial RNA dependent RNA polymerases (RdRp) and complete movement protein (MP) and the coat protein (CP) nucleotide sequences of three new ToMV isolates collected from major crop fields in Iran revealed low genetic variation of RdRp gene compared to the CP and MP genes. The different topologies of the phylogenetic trees constructed, using available open reading frame (ORF1), ORF2 and ORF3 sequences from ToMV isolates, indicated different evolutionary constraints in these genomic regions. Statistical analysis also revealed that with the exception of CP other tested ToMV genes were under negative selection and the RdRp gene was under the strongest constraints. According to the phylogenetic tree it can be inferred from the nucleotide sequences of the complete CP and MP genes, that isolates from Iran and Egypt formed separate groups, irrespective of host origin. However, isolates clustered into groups with correlation to geographic origin but not the host. Analysis of the Ks *, Z* and Snn values also indicated genetic differentiation between ToMV populations. The Tajima’s D, Fu and Li’s statistical values were significantly negative for the RdRp gene of the Asian population which suggests the sudden expansion of ToMV in Asia. Taken together, the results indicate that negative selection and genetic drift were important evolutionary factors driving the genetic diversification of ToMV.
Currently there is a constant development in the field of aluminium alloys engineering. This results from, i.a., better understanding of the mechanisms that direct strengthening of these alloys and the role of microalloying. Now it is microalloying in aluminum alloys that is receiving a lot of attention. It affects substantially the macro- and microstructure and kinetics of phase transformation influencing the properties during production and its exploitation. 7xxx series aluminum alloys, based on the Al-Zn-Mg-Cu system, are high-strength alloys, moreover, the presence of Zr and Sr further increases their strength and improves resistance to cracking. This study aims to present the changes of the properties, depending on the alloy chemical composition and the macro- and microstructure. Therefore, the characteristics in the field of hardness, tensile strength, yield strength and elongation are shown on selected examples. Observations were made on ingot samples obtained by semi-continuous casting, in the homogenized state. Samples were prepared from aluminum alloys in accordance with PN-EN 573-3: 2013. The advantage of Al-Zn-Mg-Cu alloys are undoubtedly good strength, Light-weight and resistance to corrosion. As widening of the already published studies it is sought to demonstrate the repeatability of the physical parameters in the whole volume of the sample.
Sensitivity analysis of the dynamic response of both the designed and the actual models of a slewing superstructure with two masts to the variation of the counterweight mass and the degree of accuracy of the approximation polynomials of the digging resistance was conducted in the paper. Spatial reduced dynamic models of the bucket wheel excavator SchRs 1600 were used as a basis for the presented investigations. Based on the comparative analysis of the calculation results, the following conclusions were drawn: (a) mass of the counterweight has a significantly higher influence on the maximum intensities of accelerations of the referent points than on the spectrum of natural frequencies, (b) the accuracy of approximations of the digging resistance and the maximum values of accelerations differ by an order of magnitude, for the approximation trigonometric polynomial of the same number of harmonics.
Th e forearm is a body region of numerous anatomical variations. Due to its favorable anatomy fl exor digitorum superfi cialis muscle (FDS) is commonly used in tendon transfer surgeries. In this study a unique combination of abnormalities was found in a single forearm: the fl exor digitorum superfi cialis muscle penetrated by the median nerve, one of the fl exor digitorum superfi cialis tendons early division and absence of the palmaris longus muscle. Described variation potentially may lead to the clinical manifestation of the median nerve compression and should be also considered during FDS surgery.