Jianning Su

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 x 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 K(a)/K(s) ratios >1 (where K(a) is the nonsynonymous substitution rate and K(s) 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.

Problem-solving is essential in various fields, including business, technology, and everyday life. It often involves a combination of experience, knowledge, intuition, and rational analysis. Furthermore, it requires integrating disciplines such as logic and reasoning, mathematics, algorithms, Python, and generative AI in today's complex world. We will provide detailed descriptions of how to solve problems based on integrating previously mentioned disciplines. Later, we will discuss how to guide students through making intelligent investment decisions.

There are around 857 items on Pell numbers in the On-Line Encyclopedia of Integer Sequences. Mathematicians and Computer Scientists love Pell numbers because they seem to be very easy, but they are related to many challenging topics. We will discuss some properties, algorithms, and Python programs used to generate Pell numbers, conjectures, and applications of Pell numbers.

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.