The COVID-19 pandemic presented several challenges, leaving the specific impact of class closures on student performance unclear. To address this, researchers examined the effect of pre-pandemic class closures due to influenza outbreaks on students’ test scores in Japan. They found that class closures adversely affected the math scores of elementary school boys from low-income households, likely due to lost instructional time and unhealthy behaviors. Fortunately, high-quality teachers could help students recover from the learning loss.

It begins as a trickle high on the Tibetan Plateau—icy, remote, and pure. By the time it reaches the Three Gorges, the Yangtze River has grown into a force of nature, carrying not just water, but the chemical fingerprint of an entire continent. Now, a groundbreaking study from Peking University reveals the invisible story hidden in the river’s flow: the molecular evolution of dissolved organic matter (DOM) along a 3,500-kilometer stretch of the upper Yangtze—the world’s third-longest river. Published on August 11, 2025, in Carbon Research as an open-access original article, this research was led by Dr. Dongqiang Zhu from the College of Urban and Environmental Sciences and the Key Laboratory of the Ministry of Education for Earth Surface Processes at Peking University, Beijing. Using a powerful suite of analytical tools—including fluorescence spectroscopy, lignin phenol markers, and ultra-high-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS)—Dr. Zhu’s team traced how organic carbon changes as it travels from the river’s high-altitude headwaters to its densely populated downstream reaches. And what they found is a dynamic, ever-changing mosaic of carbon chemistry shaped by glaciers, grasslands, wildfires, forests, and sunlight.