The U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists have worked in agricultural and natural ecosystems, including agronomic and horticultural crops, pastures, forests, wild lands, aquatic habitats, wetlands, and riparian areas. Through strong partnerships with academia, state agencies, private industry, and numerous federal programs, ARS weed scientists have made contributions to discoveries in the newest fields of robotics and genetics, as well as the traditional and fundamental subjects of weed–crop competition and physiology and integration of weed control tactics and practices. Weed science at ARS is often overshadowed by other research topics; thus, few are aware of the long history of ARS weed science and its important contributions. This review is the result of a symposium held at the Weed Science Society of America’s 62nd Annual Meeting in 2022 that included 10 separate presentations in a virtual Weed Science Webinar Series. The overarching themes of management tactics (IWM, biological control, and automation), basic mechanisms (competition, invasive plant genetics, and herbicide resistance), and ecosystem impacts (invasive plant spread, climate change, conservation, and restoration) represent core ARS weed science research that is dynamic and efficacious and has been a significant component of the agency’s national and international efforts. This review highlights current studies and future directions that exemplify the science and collaborative relationships both within and outside ARS. Given the constraints of weeds and invasive plants on all aspects of food, feed, and fiber systems, there is an acknowledged need to face new challenges, including agriculture and natural resources sustainability, economic resilience and reliability, and societal health and well-being.

Shallow firn cores, in addition to a near-basal ice core, were recovered in 2018 from the Quelccaya ice cap (5470 m a.s.l) in the Cordillera Vilcanota, Peru, and in 2017 from the Nevado Illimani glacier (6350 m a.s.l) in the Cordillera Real, Bolivia. The two sites are ~450 km apart. Despite meltwater percolation resulting from warming, particle-based trace element records (e.g. Fe, Mg, K) in the Quelccaya and Illimani shallow cores retain well-preserved signals. The firn core chronologies, established independently by annual layer counting, show a convincing overlap indicating the two records contain comparable signals and therefore capture similar regional scale climatology. Trace element records at a ~1–4 cm resolution provide past records of anthropogenic emissions, dust sources, volcanic emissions, evaporite salts and marine-sourced air masses. Using novel ultra-high-resolution (120 μm) laser technology, we identify annual layer thicknesses ranging from 0.3 to 0.8 cm in a section of 2000-year-old radiocarbon-dated near-basal ice which compared to the previous annual layer estimates suggests that Quelccaya ice cores drilled to bedrock may be older than previously suggested by depth-age models. With the information collected from this study in combination with past studies, we emphasize the importance of collecting new surface-to-bedrock ice cores from at least the Quelccaya ice cap, in particular, due to its projected disappearance as soon as the 2050s.

Recent studies implicate maternal gestational diabetes mellitus (GDM) in differential methylation of infant DNA. Folate and vitamin B12 play a role in DNA methylation, and these vitamins may also influence GDM risk. The aims of this study were to determine folate and vitamin B12 status in obese pregnant women and investigate associations between folate and vitamin B12 status, maternal dysglycaemia and neonatal DNA methylation at cytosine-phosphate-guanine sites previously observed to be associated with dysglycaemia. Obese pregnant women who participated in the UK Pregnancies Better Eating and Activity Trial were included. Serum folate and vitamin B12 were measured at the oral glucose tolerance test (OGTT) visit. Cord blood DNA methylation was assessed using the Infinium MethylationEPIC BeadChip. Regression models with adjustment for confounders were used to examine associations. Of the 951 women included, 356 (37.4%) were vitamin B12 deficient, and 44 (4.6%) were folate deficient. Two-hundred and seventy-one women (28%) developed GDM. Folate and vitamin B12 concentrations were not associated with neonatal DNA methylation. Higher folate was positively associated with 1-h plasma glucose after OGTT (β = 0.031, 95% CI 0.001–0.061, p = 0.045). There was no relationship between vitamin B12 and glucose concentrations post OGTT or between folate or vitamin B12 and GDM. In summary, we found no evidence to link folate and vitamin B12 status with the differential methylation of neonatal DNA previously observed in association with dysglycaemia. We add to the evidence that folate status may be related to maternal glucose homoeostasis although replication in other maternal cohorts is required for validation.

As part of the roundtable “International Institutions and Peaceful Change,” this essay examines the role of institutional soft balancing in bringing forth peaceful change in international relations. Soft balancing is understood as attempts at restraining a threatening power through institutional delegitimization, as opposed to hard balancing, which relies on arms buildup and formal alignments. We argue that soft balancing through international institutions can be an effective means to peaceful change, spanning minimalist goals, which aim at incremental change without the use of military force and war, and maximalist goals, which seek more profound change and transformation in the form of continuous interstate cooperation aimed at a more peaceful and just world order. However, the success of soft-balancing strategies in fostering peaceful change varies widely, even in today's globalized and institutionalized international environment. We explore these variations and identify three conditions for success that can inform both academic analysis and political practice: inclusion, commitment, and status recognition. We draw lessons from two historical examples: the Concert of Europe in the early nineteenth century and the League of Nations in the early twentieth century, and discuss how current threats to the liberal international order challenge soft balancing for peaceful change.

The rise of “the rest,” especially China, has triggered an inevitable transformation of the so-called liberal international order. Rising powers have started to both challenge and push for the reform of existing multilateral institutions, such as the International Monetary Fund (IMF), and to create new ones, such as the Asian Infrastructure Investment Bank (AIIB). The United States under the Trump administration, on the other hand, has retreated from the international institutions that the country once led or helped to create, including the Trans-Pacific Partnership (TPP); the Paris Agreement; the Iran nuclear deal; the Intermediate-Range Nuclear Forces (INF) Treaty; the United Nations Educational, Scientific and Cultural Organization (UNESCO); and the United Nations Human Rights Council (UNHRC). The United States has also paralyzed the ability of the World Trade Organization (WTO) to settle trade disputes by blocking the appointment of judges to its appellate body. Moreover, in May 2020, President Trump announced his decision to quit the Open Skies Treaty, an arms control regime designed to promote transparency among its members regarding military activities. During the past decade or so, both Russia and the United States have been dismantling multilateral arms control treaties one by one while engaging in new nuclear buildups at home.