We report a draft sequence for the genome of the domesticated silkworm ( Bombyx mori ), covering 90.9% of all known silkworm genes. Our estimated gene count is 18,510, which exceeds the 13,379 genes reported for Drosophila melanogaster . Comparative analyses to fruitfly, mosquito, spider, and butterfly reveal both similarities and differences in gene content.
Gene number difference among organisms demonstrates that new gene origination is a fundamental biological process in evolution. Exon shuffling has been universally observed in the formation of new genes. Yet to be learned are the ways new exons originate and evolve, and how often new exons appear. To address these questions, we identified 2695 newly evolved exons in the mouse and rat by comparing the expressed sequences of 12,419 orthologous genes between human and mouse, using 743,856 pig ESTs as the outgroup. The new exon origination rate is about 2.71 × 10-3 per gene per million years. These new exons have markedly accelerated rates both of nonsynonymous substitutions and of insertions/deletions (indels). A much higher proportion of new exons have Ka/Ks ratios >1 (where Ka is the nonsynonymous substitution rate and Ks is the synonymous substitution rate) than do the old exons shared by human and mouse, implying a role of positive selection in the rapid evolution. The majority of these new exons have sequences unique in the genome, suggesting that most new exons might originate through “exonization” of intronic sequences. Most of the new exons appear to be alternative exons that are expressed at low levels.
1 December 2024 in Online Journal of Applied Knowledge Management
This paper investigates the dynamic interplay between Artificial Intelligence (AI) and human logic in the domain of mathematical problem-solving. By critically examining a series of case studies, we compare the efficacy of AI-generated solutions, particularly those offered by ChatGPT, against traditional human problem-solving methods. The study employs various mathematical challenges, ranging from abstract logical puzzles to applied numerical problems, to evaluate AI's problem-solving approach and alignment with human cognitive processes. Our analysis highlights instances where AI's computational strategies complement or diverge from human reasoning, shedding light on AI's potential and limitations in deciphering mathematical problems. Furthermore, we explore the implications of integrating AI tools in educational contexts, specifically their role in enhancing students' mathematical problem-solving skills. The paper aims to contribute to the ongoing discourse on the optimal utilization of AI in education, proposing a balanced approach that leverages AI's computational power while fostering the depth and creativity of human logic. Through this comparative study, we advocate for a collaborative model where AI and human reasoning merge to enrich the educational landscape, particularly in the teaching and learning of mathematics.
A Rubik’s Snake is a toy that has been around for more than 40 years. It can be twisted to many interesting shapes. In particular a Rubik’s Snake can be twisted to form a knot. The trefoil knot is the simplest non-trivial knot. In this paper we study how many blocks are needed to form a trefoil knot for the original version of the Rubik’s Snake with integer multiple of 90 degree rotations for joints. We also study how many blocks are needed to form a trefoil knot using the tube version of the Rubik’s Snake.
The domination (number) of a graph , denoted by , is the size of the minimum dominating sets of , also known as -sets. As such, the dominion of G, denoted by , counts all its -sets. We proved a conjecture from one of the authors on the dominion of cycles and , . Further, we found the formulae and recurrence relations for the dominions of several grids, , with and other results when and . In general, domination and dominion play important roles in assessing certain vulnerabilities of any given network system.