Two different cytoplasmic male-sterility (CMS) systems, nap and pol, are found in the oilseed rape (canola) species Brassica napus. Physical mapping studies have previously shown that organizational differences between the sterile pol and fertile cam mitochondrial genomes are restricted to a relatively small region immediately upstream of the atp6 gene. An approximately 4.5-kb pol mtDNA segment containing a chimeric open reading frame (orf224) co-transcribed with atp6 is missing from cam mtDNA and located at a different site on nap mtDNA; expression of the orf224/atp6 gene region is highly correlated with the pol CMS trait. Sequence analysis now shows that the transposed nap segment contains an open reading frame (ORF) related to, but distinct from, pol orf224. This open reading frame (orf222) potentially encodes a protein of 222 amino acids possessing 79% sequence similarity to the predicted product of the pol orf224 gene. nap orf222 is co-transcribed with the third exon of the trans-spliced nad5 gene and another ORF. orf222 transcripts are several times more abundant in nap CMS than in fertility restored nap-cytoplasm plants and qualitative transcript differences for the region between CMS and restored plants are found as well. Expression of the orf222/nad5c/orf139 region is specifically correlated with nap CMS: of 21 mitochondrial gene regions examined, including all the sites of rearrangement between the nap and fertile cam mitochondrial genomes and 22 known genes, only the orf222/nad5c/orf139 region detected transcript differences between maintainer cam cytoplasm, nap CMS- and fertility restored nap cytoplasm-plants. Our results suggest that expression of the orf222/nad5c/orf139 region may be associated with nap CMS, and, more generally, that different forms of CMS may be associated with genes encoding structurally similar proteins.
The present study explores the impact of the age-diverse workforce (young and old employees) on organization’s performance (financial and non-financial) and how job crafting mediates the relationship between age-diverse workforce and organization’s performance. By following the administrative survey approach, a total of 450 questionnaires were distributed to the employees of the Pakistan Post Office; however, 288 properly filled questionnaires (64%) were received back. The partial least squares–structural equation modeling (PLS-SEM) approach was used for data analyses. The outcomes of this study explain that there is a significant relationship between both age groups of employees (young and old) and an organization’s financial and non-financial performance. In addition, job craft partially mediates the relationship between young-age employees and organization’s financial and non-financial performance. However, job crafting fails to mediate the association between old-age employees and organization’s financial and non-financial performance. Implications, limitations, and future direction are discussed in the last sections of this study.
Snake robots are the multibody mechanisms allowing us to solve specific problems efficiently, i.e., navigate into diverse environments and maneuver through tight spaces or uneven grounds in a way that resembles living organisms. However, the path following and controlling such systems is challenging due to nonlinear dynamics, coupling between links, and nonstandard definitions of the set-point that differ from industrial applications. This paper describes a framework for simulation and evaluation of the controller design for snake robot as the set of tools for the 3D design and robot dynamic simulation. Combined with a theoretical background (equations of robot dynamics), it allows testing new solutions and strategies of robot control design. Firstly, based on the proposed methodology, we provide a mechanical design of a ten-link snake robot. We present control algorithms enabling point-to-point tracking of the robot position in two cases: (i) tracking the center of gravity of the robot and (ii) tracking the position of the head of the robot. Then we provide a simulation-based robustness analysis of a simple fault-tolerant control algorithm, where some snake robot joints are broken. The proposed framework can be used efficiently to study control strategies for multibody mechanisms.
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