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.

Lacustrine sedimentary records and the proxies contained within them are valuable archives of past climate. However, the resolution of these records is frequently coarse or contains a high degree of uncertainty, making it difficult to resolve how climatic variability impacts the ecosystems on which humans depend. The goal of this study is to couple recent sediment cores sampled at centimeter-scale resolution with paleo- and historical information about lake levels to document how changes in the paleoenvironment impact the paleoecology of a rift basin lake. We present multiproxy data from three short cores collected from Ferguson's Gulf (FG), a shallow embayment connected to the western shore of Lake Turkana, Kenya. Five distinct biozones were interpreted on the basis of ostracods and geochemistry (δ18O, δ13C, and major elements), spanning the Little Ice Age (LIA) to the modern. Overall, ostracod total abundance and assemblage diversity decreased up-core, with the largest total abundance and genera diversity occurring during the LIA. This fits with regional datasets that indicate the Eastern Branch of the East African Rift System was wetter during the LIA than it is today. This also suggests that human impact in and around Lake Turkana has weakened the resiliency of the ecosystems in FG.

The ‘16Up’ study conducted at the QIMR Berghofer Medical Research Institute from January 2014 to December 2018 aimed to examine the physical and mental health of young Australian twins aged 16−18 years (N = 876; 371 twin pairs and 18 triplet sets). Measurements included online questionnaires covering physical and mental health as well as information and communication technology (ICT) use, actigraphy, sleep diaries and hair samples to determine cortisol concentrations. Study participants generally rated themselves as being in good physical (79%) and mental (73%) health and reported lower rates of psychological distress and exposure to alcohol, tobacco products or other substances than previously reported for this age group in the Australian population. Daily or near-daily online activity was almost universal among study participants, with no differences noted between males and females in terms of frequency or duration of internet access. Patterns of ICT use in this sample indicated that the respondents were more likely to use online information sources for researching physical health issues than for mental health or substance use issues, and that they generally reported partial levels of satisfaction with the mental health information they found online. This suggests that internet-based mental health resources can be readily accessed by adolescent Australians, and their computer literacy augurs well for future access to online health resources. In combination with other data collected as part of the ongoing Brisbane Longitudinal Twin Study, the 16Up project provides a valuable resource for the longitudinal investigation of genetic and environmental contributions to phenotypic variation in a variety of human traits.

The Fontan Outcomes Network was created to improve outcomes for children and adults with single ventricle CHD living with Fontan circulation. The network mission is to optimise longevity and quality of life by improving physical health, neurodevelopmental outcomes, resilience, and emotional health for these individuals and their families. This manuscript describes the systematic design of this new learning health network, including the initial steps in development of a national, lifespan registry, and pilot testing of data collection forms at 10 congenital heart centres.

Variation in human cognitive ability is of consequence to a large number of health and social outcomes and is substantially heritable. Genetic linkage, genome-wide association, and copy number variant studies have investigated the contribution of genetic variation to individual differences in normal cognitive ability, but little research has considered the role of rare genetic variants. Exome sequencing studies have already met with success in discovering novel trait-gene associations for other complex traits. Here, we use exome sequencing to investigate the effects of rare variants on general cognitive ability. Unrelated Scottish individuals were selected for high scores on a general component of intelligence (g). The frequency of rare genetic variants (in n = 146) was compared with those from Scottish controls (total n = 486) who scored in the lower to middle range of the g distribution or on a proxy measure of g. Biological pathway analysis highlighted enrichment of the mitochondrial inner membrane component and apical part of cell gene ontology terms. Global burden analysis showed a greater total number of rare variants carried by high g cases versus controls, which is inconsistent with a mutation load hypothesis whereby mutations negatively affect g. The general finding of greater non-synonymous (vs. synonymous) variant effects is in line with evolutionary hypotheses for g. Given that this first sequencing study of high g was small, promising results were found, suggesting that the study of rare variants in larger samples would be worthwhile.

Effects of 10 MeV electron and fast reactor neutron irradiations on carrier removal rate and deep traps spectra were compared for undoped n-GaN samples. It is shown that for electron irradiation the carrier removal rate is well accounted for by the difference in introduction rates of nitrogen-vacancy-related donors with activation energy 0.2 eV and of nitrogen-interstitial-related acceptors at Ec-1.2 eV. In the case of neutron irradiation the introduction rate of all deep traps was much lower than the carrier removal rate indicating that the main contribution to electron removal was due to disordered regions. These regions give rise to a marked persistent photocapacitance signal and a hole-trap-like feature in deep traps spectra. The Fermi level position in the core of disordered regions is located near Ec-(0.85-1) eV.

Effects of 10 MeV electron and fast reactor neutron irradiations on carrier removal rate and deep traps spectra were compared for undoped n-GaN samples. It is shown that for electron irradiation the carrier removal rate is well accounted for by the difference in introduction rates of nitrogen-vacancy-related donors with activation energy 0.2 eV and of nitrogen-interstitial-related acceptors at Ec-1.2 eV. In the case of neutron irradiation the introduction rate of all deep traps was much lower than the carrier removal rate indicating that the main contribution to electron removal was due to disordered regions. These regions give rise to a marked persistent photocapacitance signal and a hole-trap-like feature in deep traps spectra. The Fermi level position in the core of disordered regions is located near Ec-(0.85-1) eV.

Microsatellite primers are often developed in one species and used to assess neutral variability in related species. Such analyses may be confounded by ascertainment bias (i.e. a decline in amplification success and allelic variability with increasing genetic distance from the source of the microsatellites). In addition, other factors, such as the size of the microsatellite, whether it consists of perfect or interrupted tandem repeats, and whether it is autosomal or X-linked, can affect variation. To test the relative importance of these factors on microsatellite variation, we examine patterns of amplification and allelic diversity in 52 microsatellite loci amplified from five individuals in each of six populations of Cyrtodiopsis stalk-eyed flies that range from 2·2% to 11·2% mitochondrial DNA sequence divergence from the population used for microsatellite development. We find that amplification success and most measures of allelic diversity declined with genetic distance from the source population, in some cases an order of magnitude faster than in birds or mammals. The median and range of the repeat array length did not decline with genetic distance. In addition, for loci on the X chromosome, we find evidence of lower observed heterozygosity compared with loci on autosomes. The differences in variability between X-linked and autosomal loci are not adequately explained by differences in effective population sizes of the chromosomes. We suggest, instead, that periodic selection events associated with X-chromosome meiotic drive, which is present in many of these populations, reduces X-linked variation.

Incrementally applied static stretch over 3 weeks resulted in a 72 % increase in the weight of the in situ latissimus dorsi muscle in rabbits. True growth rather than tissue oedema was confirmed by increases in the protein content (130 %), the cross-sectional area of the type I fibres (30 %) and the muscle length (i.e. number of sarcomeres in series increased 25 %). Despite an increase in the proportion of fibres staining positive for the enzyme succinate dehydrogenase (SDH), the myosin ATPase stain showed no appreciable fibre type transformation. While total power output in the stretched muscle was unchanged, its maximum mass specific power output, as determined by oscillatory work loops, was decreased by 50 %. The cross-sectional area that was occupied by connective tissue increased from 15 to 19 % in the stretched muscles, with a concomitant increase in passive energy dissipation. Some incrementally stretched muscles were then allowed an additional 3 weeks of maintained stretch to determine whether the adaptive changes would be preserved or reversed. Previous gains in muscle weight, length and area of type I fibres all remained. In contrast, the connective tissue content and the passive properties returned to control values during this period.

Infrared imaging of interacting galaxies is especially interesting because their optical appearance is often so chaotic due to extinction by dust and emission from star formation regions, that it is impossible to locate the nuclei or determine the true stellar distribution. However, at near-infrared wavelengths extinction is considerably reduced, and most of the flux from galaxies originates from red giant stars that comprise the dominant stellar component by mass. Thus near infrared images offer the opportunity to study directly components of galactic structure which are otherwise inaccessible. Such images may ultimately provide the framework in which to understand the activity taking place in many of the mergers with high IRAS luminosities.

We present infrared (IR) spectroscopy and imaging of the supernova remnant IC443. [FeII] 1.644µm, Brackett γ and H2 1-0 S(l) were detected. The most striking feature of the spectra is the high [FeII] 1.644µm/Brackett γ ratio, which is typically ~30. We argue that this ratio is due to shock excitation. Two 5’×3’ maps of the remnant in the 1.644µm [FeII] line are used to study the line excitation. The IR [FeII] line is a sensitive probe for regions of shocked gas which is especially useful where the extinction is high, or the shocks are too slow to excite optical lines.