Quorum sensing (QS) is a type of cell-cell communication using signal molecules that are released and detected by cells, which respond to changes in their population density. A few studies explain that QS may operate in a density-dependent manner; however, due to experimental challenges, this fundamental hypothesis has never been investigated. Here, we present a microfluidic static droplet array (SDA) that combines a droplet generator with hydrodynamic traps to independently generate a bacterial population gradient into a parallel series of droplets under complete chemical and physical isolation. The SDA independently manipulates both a chemical concentration gradient and a bacterial population density. In addition, the bacterial population gradient in the SDA can be tuned by a simple change in the number of sample plug loading. Finally, the method allows the direct analysis of complicated biological events in an addressable droplet to enable the characterization of bacterial communication in response to the ratio of two microbial populations, including two genetically engineered QS circuits, such as the signal sender for acyl-homoserine lactone (AHL) production and the signal receiver bacteria for green fluorescent protein (GFP) expression induced by AHL. For the first time, we found that the population ratio of the signal sender and receiver indicates a significant and potentially interesting partnership between microbial communities. Therefore, we envision that this simple SDA could be a useful platform in various research fields, including analytical chemistry, combinatorial chemistry, synthetic biology, microbiology, and molecular biology.

The purpose of this research is to see how continent specific sports rose to its modern-day status through globalization. This research focuses on the historical background of how England’s football, America’s national pastime, baseball, Japan’s Judo, and Korea’s Taekwondo developed into sports in addition to the reasoning behind its globalization. Promoted by England and the rest of the European continent, Soccer is considered to be one of the world’s most popular sports and has served its function as a form of cultural imperialism. It has also advanced alongside commerce, missionary work and other types of cultural clashes. In America, baseball was used to integrate its multicultural society and developed so that the team captain leads the rest of his team. The sports of Oriental countries were reborn through modernization that was influenced by the modern rationality, education etc. of its Western counterparts. Judo and Taekwondo were introduced globally through the Olympic Games. As mentioned above the birth of sporting events has a close connection to a nation’s cultural background and globalization has taken different forms depending on which continent it originated from.