Marie Kondo, a Japanese organization expert, talks about objects being able to “spark joy” for those who own them. She says in her best-selling book “The life-changing magic of tidying up: The Japanese art of decluttering and organizing” that we should “keep only the things that spark joy” when advising people as they go through their decluttering journey. Given Kondo’s popularity, this phrase has influenced Western popular culture in the past few years. Still, there is no specific definition of spark joy in her books nor her Netflix show. In Japan, spark joy or tokimeki, is a common phrase that has been used since the 900s, but the phrase has been used more to describe the emotions surrounding romantic relationships rather than for objects. Previous studies on the meaning of objects (largely in the West) have indicated more focus on the self-reflection brought on by an object rather than relational reasons for seeing an object as special. For instance, objects have been found to represent self and achievement. People also give meaning to an object based on memories or identities, such as ties with ones’ family or ethnic background, suggesting some relational ties to an object. In this research, I examine what object sparks joy to people and what “spark joy” means to them. The research was conducted by interviewing people from Japan and the U.S., where popular culture has been influenced by her methods. I also had participants complete assessments of their self-construals and attachment styles. Qualitative data were examined by content analysis where I looked for relationships between self-construals and attachment styles to see if these predict the ways people give meaning to an object. This research deepens knowledge about objects and their meanings as well as provides a cultural comparison of what spark joy means to people.

The link between protein sequence and structure is not always apparent. The dogma is that sequence determines structure, but it is not clear how very different sequences can give rise to the same structure. Here, we employ high temperature molecular dynamics unfolding simulations to probe the pathways and specific interactions that direct the folding and unfolding of the SH3 domain, a family of small proteins consisting of two β-sheets arranged to form a barrel. SH3 domain proteins are involved in various functions including protein binding, cell signaling, and nucleic acid modification. The SH3 metafold consists of 753 proteins with the same structure but varied sequence and function. To investigate the relationship between sequence and structure, we selected 17 SH3 proteins with an average pairwise sequence identity of only 27%. Six unfolding simulations were performed for each protein and unfolding transition states were determined, revealing two unfolding/folding pathways. Transition states were also expressed as mathematical graphs of contacts between chemical groups, and three positions in the transition state structure were consistently more connected to the rest of the graph than other nearby positions. These positions represent a folding hub connecting different portions of the structure in the transition state. Analysis of the multiple sequence alignment and covariation also highlighted positions with high conservation due to packing constraints and long-range contacts. This study demonstrates that the SH3 domain can fold through two distinct pathways, but certain folding/unfolding characteristics are conserved independent of sequence and unfolding pathway. By identifying similar interactions, we demonstrate how different sequences can have the same influence on folding pathway and final structure.