Lab-Theory Standing Talks

Complexity, expressivity, syntax and semantics

March 14 (Fri) at 14:00 - 14:30, 2025

Yusaku Nishimiya (Student Trainee, Natural Language Understanding Team, RIKEN Center for Advanced Intelligence Project (AIP))

I will summarise the philosophical motivations behind two research topics; 1. complexity/computability and 2. logic (structural proof theory), and discuss how they may help us understand what makes some problems harder than others, or equivalently, some knowledge more difficult to attain than others (my broad research goals). I. Complexity/computability Computational complexity and computability theory are a subfield of theoretical computer science in which we mathematically study the 'hardness' of problems. We do so by classifying algorithms or a collection of pre-defined rules that some solver can apply without ingenuity by how much time and memory space they require. II. Structural proof theory Even whilst maintaining the basic idea that a well-formed sentence, or a proposition, is either true or false, one can still make a conscious choice about what kind of principles to permit in deriving a new statement from assumptions. Structural proof theory formalises this as a logical-deduction system to study their effect on what the logic can and cannot do. III. What I do, more specifically I take advantage of equivalences between some computational complexity classes and logic, the latter of which, I hope, can serve as an interface to connect, via semantics, complexity with wider mathematics to elucidate something that can tell us what makes some computation inherently costly. IV. 'Computational view' of science I would love to discuss if time permits, how we may apply the idea of complexity to illuminate how information transfers from one thing to another in physical, biological and social systems.

Venue: 3rd floor public space, Main Research Building

Event Official Language: English

Sustainable Organic Synthesis with Abundant Resources

April 15 (Mon) at 13:00 - 14:00, 2024

Sobi Asako (Senior Scientist, Advanced Organic Synthesis Research Team, RIKEN Center for Sustainable Resource Science (CSRS))

The sustainable development of modern society necessitates technologies that harness earth-abundant metals and organic resources, minimizing reliance on scarce materials. This presentation will introduce our recent efforts towards this goal. We have developed sustainable organic synthesis using sodium dispersion, a molybdenum-quinone species for the diazo-free generation of carbene species from stable and readily available compounds, and a SpiroBpy ligand that enables the site-selective functionalization of arenes under remote steric control. I will also share some of the challenges we face in developing these reactions in order to ensure reproducibility.

Venue: 3rd floor public space, Main Research Building

Event Official Language: English

Basic experimental considerations for analyzing gene expression

February 28 (Wed) at 13:00 - 14:00, 2024

Hirotaka Toh (JSPS PD Researcher, RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research (CPR))

Methods such as RNA-sequencing and ribosome profiling are indispensable tools for the comprehensive elucidation of the mechanisms underlying gene expression. A fundamental aspect that requires meticulous attention in the execution of these experiment is the extraction of intact RNA and Ribosomes. The integrity and purity of the extracted RNA is critical to ensure the accuracy and reliability of the sequencing data. In this seminar, I will introduce the basic but key points of the extraction process.

Venue: 3rd floor public space, Main Research Building

Event Official Language: English

Lab-Theory Standing Talk #2

September 5 (Tue) at 13:00 - 13:50, 2023

Yusaku Nishimiya

Venue: 3rd floor public space, Main Research Building

Event Official Language: English

Lab-Theory Standing Talks #1

March 16 (Thu) at 13:00 - 13:30, 2023

Hideshi Ooka (Research Scientist, Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science (CSRS))

Venue: 3rd floor public space, Main Research Building

Event Official Language: English