Using data from all 50 US states plus the District of Columbia, two mathematicians have developed a new method to analyse COVD-19 rates to help policymakers identify demonstrable turning points in infection surges.
As the COVID-19 pandemic continues, some locations have experienced decreasing numbers of cases followed by an increase. In the journal Chaos, mathematicians report a method to analyze these numbers for evidence of a first or second wave. The authors studied data from all 50 U.S. states plus D.C. for the seven-month period from Jan. 21 to July 31. They found 31 states and D.C. were experiencing a second wave as of the end of July.
The COVID-19 pandemic has caused "kinks" in the movement of goods and services around the globe, but how important a role do multinational companies play in local economies and supply chains?
Using data from humans and other mammals, a team of scientists including researchers from the Santa Fe Institute has developed one of the first quantitative models that explains why sleep times across species and during development decrease as brains get bigger. Crucially, the model identifies a sharp transition at around 2.4 years of age, where sleep patterns change in humans as the primary purpose of sleep shifts from reorganization, which is essentially learning, to repair.
In the 2019 Boeing 737 Max crash, the recovered black box from the aftermath hinted that a failed pressure sensor may have caused the ill-fated aircraft to nose dive. This incident and others have fueled a larger debate on sensor selection, number and placement to prevent the reoccurrence of such tragedies. Texas A&M University researchers have now developed a comprehensive mathematical framework that can help engineers make informed decisions about which sensors to use.
A paper published in the Proceedings of the National Academy of Science (PNAS) explains the advantage that animals have of using a specific type of chaotic type of movement called a "Lévy walk," and how this type of behavior emerges. Using computer modeling, the author shows that this type of movement can allow animals to make flexible decisions between "exploitation" and "exploring" in an environment.
Researchers have analyzed data from deep-sea sediments in order to reconstruct Earth's climate with an unprecedented temporal resolution. To achieve this, the international team, led by Dr. Thomas Westerhold of MARUM and Dr. Norbert Marwan of PIK, compiled and analyzed a comprehensive dataset obtained from sediment cores from the ocean floor. The team's new climate reference curve is now published in Science.
In the paper, 'How directed is a directed network?', published today, the 9th September in the journal Royal Society Open Science, researchers from the University of Warwick and the University of Birmingham reveal a new method for analysing hierarchies in complex networks and illustrate it by applications to economics, language and gene expression.
At the macroscopic level, there are numerous examples of people cooperating to form groupings. Yet at the basic two-person level, people tend to betray each other, as found in games like the prisoner's dilemma, even though people would receive a better payoff if they cooperated among themselves. The topic of cooperation and how and when people start trusting one another has been studied numerically, and in the journal Chaos, researchers investigate what drives cooperation analytically.
In physics, it is essential to be able to show a theoretical assumption in actual, physical experiments. For more than a hundred years, physicists have been aware of the link between the concepts of disorder in a system, and information obtained by measurement. However, a clean experimental assessment of this link in common monitored systems, that is systems which are continuously measured over time, was missing so far.