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.

Seedlings of wheat (Triticum aestivum L.), corn (Zea mays L.), and sorghum (Sorghum vulgare Pers.) were exposed to 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) in solution culture. Following prolonged treatment, the tolerant species, corn and sorghum, accumulated leaf concentrations of unaltered atrazine which were comparable to those found in the sensitive species at the point of acute toxicity. In the sensitive species, wheat, there did not seem to be a critical leaf concentration of atrazine which was necessary to bring about acute toxicity. The leaf concentration in wheat could be raised by increasing the concentration of atrazine in the nutrient solution or by lowering the temperature at which the plants were grown. The loss of chlorophyll in sensitive species was closely related to and preceded acute toxicity symptoms.

Background: Oncotype DX (ODX), a tumor gene profiling test, has been incorporated into clinical guidelines to aid in adjuvant chemotherapy decision making for early-stage, hormone receptor positive breast cancer patients. Despite United States (U.S.) guidelines, less than half of eligible women receive testing. Reasons for low usage are unclear: Our objective was to better understand U.S. oncologists’ ODX uptake and how they use ODX during adjuvant chemotherapy decision making.

Methods: We conducted semi-structured, ~30-minute phone interviews with medical and surgical oncologists in one U.S. State using purposive sampling. Oncologists were included if they saw greater than or equal to five breast cancer patients per week. Recruitment ended upon thematic saturation. Interviews were recorded, transcribed, and double-coded using template analysis.

Results: During analysis, themes emerged across three domains. First, organizational factors (i.e., departmental structure, ODX marketing, and medical/insurance guidelines) influenced ease of ODX use. Second, oncologists referenced the influence of interpersonal factors (e.g., normative beliefs and peer use of ODX) over their own practices and recommendations. Third, intrapersonal factors (e.g., oncologist attitudes, perceived barriers, and research gaps) were discussed: although oncologists largely held positive attitudes about ODX, they reported challenges with interpreting intermediate scores for treatment decisions and explaining test results to patients. Finally, oncologists identified several research gaps.

Conclusions: As more tumor gene profiling tests are incorporated into cancer care for treatment decision making, it is important to understand their use in clinical practice. This study identified multi-level factors that influence ODX uptake into clinical practice, providing insights into facilitators and modifiable barriers that can be leveraged for improving ODX uptake to aid treatment decision making.

This paper reports a study of local orientation change occurring within micro-scale tensile samples as a function of strain. These samples were fabricated from a thin film of single crystal bcc Fe and deformed in tension using an in situ micro-mechanical testing device inside a scanning electron microscope. Samples were loaded along the <110> direction parallel to the specimen axis, strained to different levels, and then subjected to electron backscatter diffraction scans over the entire area of the gauge section. Analysis of the surface orientation data shows that, within a necked zone of the micro-sample gauge section, there are two distinct regions of significant orientation change, in which local crystal rotations occur in opposite directions. These two regions are separated by an intermediate band that shows minimal misorientation from the original state. Crystal rotations within the two regions that develop opposite orientations are found to be consistent with classic single crystal slip, where the slip direction rotates toward the tensile axis. It is shown that increasing tensile strain causes an increasing degree of rotation away from the starting orientation. The tests also illustrate the occurrence of slip on at least two different slip systems, based on the slip traces and orientation change.

In an attempt to study the thermal transport at the interface between nanotubes and graphene, vertically aligned multiwalled carbon nanotubes (CNTs) were grown on graphite thin film substrates. A systematic cross-sectional probing of the materials’ morphology of the interface by scanning electron microscopy and high-resolution transmission electron microscopy revealed that an excellent bond existed between the nanotubes and the substrate along some fraction of interface. Imaging and electron diffraction analyses performed at the boundary reveal a polycrystalline interfacial structure. Compositional probing along the interface by energy dispersive x-ray spectroscopy revealed that there were no catalyst particles or other impurities present. The estimated interfacial thermal resistance of lower than 5–7.5 (mm2K)/W suggests that this type of CNT/graphite interface could open up multiple routes toward the designing and development of advanced thermal interface materials for aerospace and nano-/microelectronics applications.

Fungivorous Coleoptera were sampled from old-growth and managed (selectively logged in 1999) hemlock–hardwood forests in southeastern Ontario to examine the effect of small-scale forest management on fungivore diversity in forest fragments. Sampling using flight-intercept traps and trunk-window traps for 22 weeks in 2003 yielded 11 888 beetles representing 73 species in 11 target families (Anthribidae, Cerylonidae, Endomychidae, Erotylidae, Leiodidae, Mycetophagidae, Scaphidiidae, Sphindidae, Tenebrionidae, Trogossitidae, and Zopheridae). The leiodid subfamily Leiodinae was the dominant taxon (10 386 individuals, 38 species). While old-growth stands had no recent logging and had higher volumes of coarse woody debris, species diversity and composition of fungivorous Coleoptera were similar between forest types, suggesting that the stand differences measured (recent logging history, volume of coarse woody debris) did not have a significant effect on beetle diversity in this study. Indicator species analysis showed that Triplax macra LeConte (Erotylidae) was strongly associated with old-growth stands, while Anisotoma blanchardi (Horn), Anogdus obsoletus (Melsheimer), Agathidium sp. 1 (Leiodidae), and Mycetina perpulchra (Newman) (Endomychidae) were associated with managed stands. The lack of difference observed between stand types may be related to the small size of the forest fragments or the relatively small scale of the disturbance.

Nitidulid beetles were sampled from old-growth and mature managed hemlock-hardwood forest stands in southeastern Ontario, Canada. Large-area flight-intercept traps and trunk-window traps were operated for 22 weeks in 2003 and yielded 2129 nitidulid beetles representing 30 species. Species richness was similar in both forest types but relative abundance was higher in managed stands. Other diversity measures (rarefaction-estimated species richness, Fisher's α, Simpson's index) were all higher in old-growth stands, and managed stands were separated from old-growth stands in cluster analyses based on overall species diversity. These results were strongly influenced by the dominance of Glischrochilus quadrisignatus (Say) in two managed stands; removal of that species from analyses resulted in higher species diversity in managed stands and no distinct separation of forest types in cluster analyses. Indicator species analysis showed that G. quadrisignatus and Pallodes pallidus (Palisot de Beauvois) were strongly associated with managed stands. Glischrochilus sanguinolentus (Olivier) was collected more frequently in trunk-window traps than in flight-intercept traps and data suggested a possible association of this beetle with old-growth stands. Pallodes pallidus and Cychramus adustus Erichson, both known to feed on fleshy white fungi, displayed a clear division in seasonal abundance peaks, suggesting that resource partitioning may be occurring.

In small-scale testing at elevated temperatures, impurities in inert gases can pose problems so that testing in vacuum would be desirable. However, previous experiments have indicated difficulties with thermal stability and instrument noise. To investigate this, measurements of the temperature changes in a modified nanoindenter have been made and their influence on the displacement and load measurements is discussed. It is shown that controlling the temperatures of the indenter tip and the sample enabled flat punch indentations of gold, a good thermal conductor, to be carried out over several minutes at 665 °C in vacuum, as well as permitting thermal stability to be quickly re-established in site-specific microcompression experiments. This allowed compression of nickel superalloy micropillars up to sample temperatures of 630 °C with very low levels of oxidation after 48 h. Furthermore, the measured Young moduli, yield and flow stresses were consistent with literature data.