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Abstract Background Native warm‐season grass (NWSG) mixtures may provide a low‐nitrogen (N)‐input summer perennial forage option to extensively managed forage–livestock systems. Methods Mixed pastures of big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium Michx.), and indiangrass (Sorghastrum nutans L.) fertilized with 0 or 67 kg N ha−1 were continuously stocked with beef heifers and cows. Forage mass, nutritive value, and canopy heights were determined every 2 weeks during the grazing season. Stand persistence measures included the canopy cover and leaf area index (LAI) and plant crown density at spring emergence following 3 years of grazing management. Results Forage mass, canopy height, and stocking densities were greater for N‐fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3‐year study. Forage NWSG fertilized with N had a greater decrease in LAI during the growing season (51% decrease) than unfertilized NWSG. Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies. Conclusions Forage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low‐level N than zero‐N‐input systems and may provide a low‐N‐input alternative for improved species use in southeastern US forage–livestock systems.

The spatial distribution of snow plays a vital role in sub-Arctic and Arctic climate, hydrology, and ecology due to its fundamental influence on the water balance, thermal regimes, vegetation, and carbon flux. However, the spatial distribution of snow is not well understood, and therefore, it is not well modeled, which can lead to substantial uncertainties in snow cover representations. To capture key hydro-ecological controls on snow spatial distribution, we carried out intensive field studies over multiple years for two small (2017–2019; ∼ 2.5 km2) sub-Arctic study sites located on the Seward Peninsula of Alaska. Using an intensive suite of field observations (> 22 000 data points), we developed simple models of the spatial distribution of snow water equivalent (SWE) using factors such as topographic characteristics, vegetation characteristics based on greenness (normalized different vegetation index, NDVI), and a simple metric for approximating winds. The most successful model was random forest, using both study sites and all years, which was able to accurately capture the complexity and variability of snow characteristics across the sites. Approximately 86 % of the SWE distribution could be accounted for, on average, by the random forest model at the study sites. Factors that impacted year-to-year snow distribution included NDVI, elevation, and a metric to represent coarse microtopography (topographic position index, TPI), while slope, wind, and fine microtopography factors were less important. The characterization of the SWE spatial distribution patterns will be used to validate and improve snow distribution modeling in the Department of Energy's Earth system model and for improved understanding of hydrology, topography, and vegetation dynamics in the sub-Arctic and Arctic regions of the globe.

The COVID-19 pandemic led to the rapid and worldwide development of highly effective vaccines against SARS-CoV-2. However, there is significant individual-to-individual variation in vaccine efficacy due to factors including viral variants, host age, immune status, environmental and host genetic factors. Understanding those determinants driving this variation may inform the development of more broadly protective vaccine strategies. While host genetic factors are known to impact vaccine efficacy for respiratory pathogens such as influenza and tuberculosis, the impact of host genetic variation on vaccine efficacy against COVID-19 is not well understood. To model the impact of host genetic variation on SARS-CoV-2 vaccine efficacy, while controlling for the impact of non-genetic factors, we used the Diversity Outbred (DO) mouse model. We found that DO mice immunized against SARS-CoV-2 exhibited high levels of variation in vaccine-induced neutralizing antibody responses. While the majority of the vaccinated mice were protected from virus-induced disease, similar to human populations, we observed vaccine breakthrough in a subset of mice. Importantly, we found that this variation in neutralizing antibody, virus-induced disease, and viral titer is heritable, indicating that the DO serves as a useful model system for studying the contribution of genetic variation of both vaccines and disease outcomes.

Both HIV infection and tenofovir disoproxil fumarate (TDF) treatment adversely impact bone metabolism and may lead to osteopenia, which has critical implications for youth with HIV (YWH). This study evaluates changes in the biomarkers of bone metabolism and inflammation among YWH receiving initial treatment with TDF- and non-TDF-containing antiretroviral therapies (ARTs). YWH [n = 23, median age 21 years (range 18-24), 87% male, 61% African American] were assessed for inflammatory and bone metabolism biomarkers at enrollment, after 48 weeks of TDF-containing ART, and 96 weeks of ART without TDF with continued viral suppression. Spearman's rank correlation evaluated biomarker associations. Bone alkaline phosphatase, parathyroid hormone, and osteopontin increased after TDF treatment. All fell after TDF was discontinued. Levels of RANKL and osteoprotegerin did not change throughout the study. There was little correlation between biomarkers of bone metabolism and either macrophage or lymphocyte activation at any time point. Our results establish baseline associations between bone metabolism and immune biomarkers for this population, and find that before CD4 T cell decline chronic inflammation does not perturb biomarkers of bone metabolism among YWH. The adverse effects of TDF on bone health may be marginal for YWH at the early stages of disease.

African American men who have sex with men and women (MSMW) are among the populations with the highest need for HIV prevention programs in the USA. We tested a theory-based, community participatory behavioral intervention aiming to reduce sexual risk for HIV transmission in this population. A randomized clinical trial involving 396 African American MSMW who were assigned to a 4-session intervention involving HIV testing and counseling (n = 199) or to a HIV testing and counseling only (n = 197) control. In the 4-session intervention program, counselors provided education on HIV and STI risk, condom use, HIV testing, interpersonal sexual dynamics with both male and female partners, and motivational "triggers" of condomless sex. Participants completed baseline, 6-month, and 9-month assessments, and changes in HIV behavioral risk indicators were examined by condition and time. There were no statistically significant differences in sexual risk between the intervention condition and the control condition. Regardless of condition, participants reported significant reductions in mean number of condomless sex events with female casual partners from baseline (6.04) to 6 months (2.58) and 9 months (1.47), and with male casual partners from baseline (2.61) to 6 months (1.18) and 9 months (0.60). Condition-by-time interaction effects and condition main effects were non-significant. Although there were no significant differences by condition, findings support the effects of brief behavioral counseling and HIV testing on reducing condomless sex with casual female and male partners among African American MSMW. Future research should examine further the potential for brief behavioral counseling to promote biomedical HIV prevention and to reduce co-morbid health issues such as substance use among African American MSMW.

This resource paper draws lessons from a twenty-year partnership between the Native Hawaiian community of Papakōlea, the Hawai‘i Alliance for Community-Based Economic Development, and the Department of Urban and Regional Planning at the University of Hawai‘i. Key players and co-authors describe five principles for sustained partnerships: (1) building partnerships based upon community values with potential for long-term commitments; (2) privileging indigenous ways of knowing; (3) creating a culture of learning together as a co-learning community; (4) fostering reciprocity and compassion in nurturing relationships; and (5) utilizing empowering methodologies and capacity-building strategies.

ABSTRACT The cytosol of eukaryotic host cells is an intrinsically hostile environment for bacteria. Understanding how cytosolic pathogens adapt to and survive in the cytosol is critical to developing novel therapeutic interventions against these pathogens. The cytosolic pathogen Listeria monocytogenes requires glmR (previously known as yvcK), a gene of unknown function, for resistance to cell-wall stress, cytosolic survival, inflammasome avoidance, and, ultimately, virulence in vivo. In this study, a genetic suppressor screen revealed that blocking utilization of UDP N-acetylglucosamine (UDP-GlcNAc) by a nonessential wall teichoic acid decoration pathway restored resistance to lysozyme and partially restored virulence of ΔglmR mutants. In parallel, metabolomic analysis revealed that ΔglmR mutants are impaired in the production of UDP-GlcNAc, an essential peptidoglycan and wall teichoic acid (WTA) precursor. We next demonstrated that purified GlmR can directly catalyze the synthesis of UDP-GlcNAc from GlcNAc-1P and UTP, suggesting that it is an accessory uridyltransferase. Biochemical analysis of GlmR orthologues suggests that uridyltransferase activity is conserved. Finally, mutational analysis resulting in a GlmR mutant with impaired catalytic activity demonstrated that uridyltransferase activity was essential to facilitate cell-wall stress responses and virulence in vivo. Taken together, these studies indicate that GlmR is an evolutionary conserved accessory uridyltransferase required for cytosolic survival and virulence of L. monocytogenes. IMPORTANCE Bacterial pathogens must adapt to their host environment in order to cause disease. The cytosolic bacterial pathogen Listeria monocytogenes requires a highly conserved protein of unknown function, GlmR (previously known as YvcK), to survive in the host cytosol. GlmR is important for resistance to some cell-wall stresses and is essential for virulence. The ΔglmR mutant is deficient in production of an essential cell-wall metabolite, UDP-GlcNAc, and suppressors that increase metabolite levels also restore virulence. Purified GlmR can directly catalyze the synthesis of UDP-GlcNAc, and this enzymatic activity is conserved in both Bacillus subtilis and Staphylococcus aureus. These results highlight the importance of accessory cell wall metabolism enzymes in responding to cell-wall stress in a variety of Gram-positive bacteria.

Angiotensin-converting enzyme 2 (ACE2), part of the renin-angiotensin system (RAS), serves as an entry point for SARS-CoV-2, leading to viral proliferation in permissive cell types. Using mouse lines in which the Ace2 locus has been humanized by syntenic replacement, we show that regulation of basal and interferon induced ACE2 expression, relative expression levels of different ACE2 transcripts, and sexual dimorphism in ACE2 expression are unique to each species, differ between tissues, and are determined by both intragenic and upstream promoter elements. Our results indicate that the higher levels of expression of ACE2 observed in the lungs of mice relative to humans may reflect the fact that the mouse promoter drives expression of ACE2 in populous airway club cells while the human promoter drives expression in alveolar type 2 (AT2) cells. In contrast to transgenic mice in which human ACE2 is expressed in ciliated cells under the control of the human FOXJ1 promoter, mice expressing ACE2 in club cells under the control of the endogenous Ace2 promoter show a robust immune response after infection with SARS-CoV-2, leading to rapid clearance of the virus. This supports a model in which differential expression of ACE2 determines which cell types in the lung are infected, and this in turn modulates the host response and outcome of COVID-19.

ABSTRACT Gardnerella is the primary pathogenic bacterial genus present in the polymicrobial condition known as bacterial vaginosis (BV). Despite BV’s high prevalence and associated chronic and acute women’s health impacts, the Gardnerella pangenome is largely uncharacterized at both the genetic and functional metabolic levels. Here, we used genome-scale metabolic models to characterize in silico the Gardnerella pangenome metabolic content. We also assessed the metabolic functional capacity in a BV-positive cervicovaginal fluid context. The metabolic capacity varied widely across the pangenome, with 38.15% of all reactions being core to the genus, compared to 49.60% of reactions identified as being unique to a smaller subset of species. We identified 57 essential genes across the pangenome via in silico gene essentiality screens within two simulated vaginal metabolic environments. Four genes, gpsA, fas, suhB, and psd, were identified as core essential genes critical for the metabolic function of all analyzed bacterial species of the Gardnerella genus. Further understanding these core essential metabolic functions could inform novel therapeutic strategies to treat BV. Machine learning applied to simulated metabolic network flux distributions showed limited clustering based on the sample isolation source, which further supports the presence of extensive core metabolic functionality across this genus. These data represent the first metabolic modeling of the Gardnerella pangenome and illustrate strain-specific interactions with the vaginal metabolic environment across the pangenome. IMPORTANCE Bacterial vaginosis (BV) is the most common vaginal infection among reproductive-age women. Despite its prevalence and associated chronic and acute women’s health impacts, the diverse bacteria involved in BV infection remain poorly characterized. Gardnerella is the genus of bacteria most commonly and most abundantly represented during BV. In this paper, we use metabolic models, which are a computational representation of the possible functional metabolism of an organism, to investigate metabolic conservation, gene essentiality, and pathway utilization across 110 Gardnerella strains. These models allow us to investigate in silico how strains may differ with respect to their metabolic interactions with the vaginal-host environment.

Education elders must engage next generation Black thinkers and doers in addressing the complex global and spiritual issues in education today. Deep listening to the young is absolutely essential to imagining a future that is worthy of Black engagement and brilliance. In this article, I bear witness and honor the righteous version of endarkened feminisms being created by young sister artists and thought leaders. As an Elder in education, I believe that is an important and relevant role in Black struggle, excellence, and education that connects our past to our today and our possible futures. In this article, I put my own recent theorizing of (re)membering into conversation with Beyoncé's film, "Black is King." My goal is to illuminate and articulate what Beyoncé helps us understand about the meanings of equity and excellence in Black education when placed within the historical and contemporary Black creative and cultural spaces of Africa and the Black African diaspora.

Background Risk perceptions are central to health behavior, but some types of risk perceptions may be more strongly connected to behavior than others. This research examined different risk perceptions of COVID-19 and their respective associations with behavior intentions and worry. Material and methods U.S. college students (N = 248) and general adults (N = 300) reported their risk perceptions of COVID-19 – including absolute numerical, verbal, comparative, and feelings of risk – as well as their worry and intentions to do things such as get vaccinated. Results Although most risk perceptions related to intentions and worry, feelings of risk were the most strongly and consistently related. The associations showed that the higher people’s feelings of risk were, the greater were their intentions and worry. Conclusions Assessing feelings of risk of COVID-19 may provide the best insight into people’s perceived threat of this virus.

Media campaigns can create change in their audiences directly via message exposure and indirectly via conversations about the campaign. An experiment (N =  232) exposed regular consumers of sugar-sweetened beverages to either strong or weak messages that advocated reduced consumption, then allowed conversation or did not. There was evidence of direct media effects in that heavy drinkers who privately judged the messages as effective reported higher intended consumption reduction. However, when conversation was allowed, it erased the desired effect of campaign messages on intended reduction. Heavy drinkers had less favorable conversations about strong campaign messages than weak ones. Further, analytic language (e.g. but, because) augmented the persuasiveness of strong messages among heavy drinkers, but detracted from the persuasiveness of weak messages. Thus, we observed a complex interplay between intra personal processes devoted to the accurate assessment of campaign messages and inter personal processes that defended existing levels of sugary beverage consumption. [ABSTRACT FROM AUTHOR]