The article provides valuable information about the scope of “PM 2.5” pollution in the United States but reveals that less is known about its even smaller cousin, “submicron” or “PM 1” particulate matter. The study published in The Lancet Planetary Health by researchers at Washington University in St. Louis aimed to quantify PM 1 over the past 25 years across America.

Randall Martin, a professor of energy, environmental and chemical engineering, emphasized that this measurement serves as a starting point for understanding which pollutants regulators could target to make the most effective health impact. The study found that the very small particles quantified generally come from direct air emissions or secondary processes when sulfur dioxide or nitrogen oxides are released through fuel combustion and burning coal.

The researchers calculated their submicron estimates based on known ratios of what makes up PM 2.5 particles, which include seven main components such as sulfate, nitrate, and mineral dust. This research sets the stage for further analysis of where, how, and why certain types of particles congregate, and how they can affect the environment and human body.

The study also revealed that pollution regulation does help. Average PM 1 levels in the air people breathe dropped sharply from 1998 to 2022, thanks to decades of environmental regulations like the Clean Air Act. However, this progress has slowed since 2010, mainly because of rising wildfire activity.

Other countries like China have a head start tracking nationwide PM 1, but now the U.S. can quickly catch up with this new dataset offering unprecedented information for the United States about an important pollutant for which few other measurements exist.

The article concludes that future pollution controls will need to address emerging, non-fossil fuel sources, and that working with epidemiologists to assess the association of PM 1 with health outcomes is a next step in this research.

The article discusses how consuming high levels of oleic acid, a type of monounsaturated fat commonly found in olive oil, may be contributing to obesity. Research published in the journal Cell Reports suggests that oleic acid can cause the body to produce more fat cells by boosting a signaling protein called AKT2 and reducing the activity of a regulating protein called LXR.

Lead researcher Michael Rudolph, Ph.D., notes that while it’s difficult to isolate specific fatty acids in human diets due to the complexity of food combinations, there is evidence that oleic acid levels are increasing in the food supply. This is particularly concerning for individuals with limited access to dietary variety and those who rely heavily on fast food.

The study involved feeding mice specialized diets enriched with different types of fatty acids, including those found in coconut oil, peanut oil, milk, lard, and soybean oil. Oleic acid was the only type that caused an increase in precursor cells that give rise to fat cells, ultimately leading to a higher capacity for storing excess nutrients.

Rudolph emphasizes the importance of moderation and variety when it comes to consuming fats. He suggests that relatively balanced levels of oleic acid may be beneficial, but higher and prolonged levels could be detrimental, particularly for individuals at risk for heart disease.

The take-home message is clear: while some types of healthy fats are essential for our well-being, overconsumption or imbalance can have negative consequences. By being mindful of the fatty acids in our diets and consuming a variety of sources, we can minimize the risks associated with obesity and related health issues.

The discovery of ipecac alkaloids in two distantly related plant species has shed light on the independent evolution of this complex biosynthetic pathway. Ipecac Carapichea ipecacuanha, a member of the gentian family, and Alangium salviifolium, a sage-leaved alangium from the dogwood family, both produce these medically interesting substances. While earlier studies had identified some enzymes involved in their production, the elucidation of the entire biosynthetic pathway has provided valuable insights into the evolutionary history of this process.

The researchers found that ipecac alkaloids are present throughout all plant tissues of both species but accumulate more heavily in young leaf tissues and underground organs. By comparing tissues with high and low levels of these compounds, genes involved in their synthesis were identified. Further genetic transformation and model plant experiments allowed the stepwise reconstruction of the biosynthetic pathway in both species.

Surprisingly, the first step in this process does not involve an enzyme but occurs spontaneously. The subsequent steps are catalyzed by a unique sugar-cleaving enzyme that has a distinct three-dimensional structure compared to other enzymes performing the same reaction. This enzyme’s unusual nature and spatial separation from its substrate within the cell may have evolved as a defense mechanism against herbivores.

The discovery of this independent evolution of ipecac alkaloid biosynthesis in two distantly related plant species highlights the plant’s ability to develop complex natural products through convergent evolution. The study also provides valuable insights into the potential pharmacological effects of downstream metabolites, such as tubulosin, which have been poorly studied due to their low abundance.

In further research, the final steps of the biosynthesis are to be elucidated, providing a more complete understanding of this complex metabolic pathway. This knowledge could ultimately lead to the production of these substances in larger quantities, allowing for more detailed investigations into their pharmacological activities.