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The effects of fire seasonality and prescribed burning on exotic species invasion are poorly understood in black greasewood (Sarcobatus vermiculatus) plant communities of North America. The impacts of reintroducing fire in the fall and spring on community composition and current-year biomass were evaluated at two such sites, one dominated by exotic annual C3 grasses in Miles City, Montana, USA, and one dominated by native perennial C4 grasses in Laramie, Wyoming, USA. Study sites were assessed based on existing Ecological Site Description (ESD) and State-and-Transition Models (STMs) and the Montana site was determined to be more degraded than the Wyoming site. Experimental design was a randomized complete block design with burns conducted in the fall of 2020 and spring of 2021. Exotic species such as Bromus arvensis were reduced by 56% in spring burned plots the following year and by 25% in the fall burned plots over the course of the study in Montana (58.3–43.5%) and Bromus tectorum did not increase in spring or fall burned plots in Wyoming. Accordingly, the proportion of native species in both plant communities remained constant and native perennial C4 grasses such as Sporobolus airoides were resilient to fire. Moreover, burn treatment had no negative effects on plant species richness, evenness, or diversity in either location. Fire treatments had variable effects on current-year biomass with variable influences of drought and season of burn. Prescribed fire, regardless of season, did not exacerbate exotic plant species spread or reduce native species dominance in either location – suggesting that phreatophytic S. vermiculatus rangelands near the eastern terminus of their range are resilient to anthropogenic burning. Future research should investigate the use of prescribed fire with other methods such as revegetation and herbicide application for reducing exotic plant dominance and increasing native plant species.

Targeted nanoparticles offer potential to selectively deliver therapeutics to cells; however, their subcellular fate following endocytosis must be understood to properly design mechanisms of drug release. Here we describe a nanoparticle platform and associated cell-based assay to observe lysosome trafficking of targeted nanoparticles in live cells. The nanoparticle platform utilizes two fluorescent dyes loaded onto PEG-poly(glutamic acid) and PEG-poly(Lysine) block co-polymers that also comprise azide reactive handles on PEG termini to attach antibody-based targeting ligands. Fluorophores were selected to be pH-sensitive (pHrodo Red) or pH-insensitive (Alexafluor 488) to report when nanoparticles enter low pH lysosomes. Dye-labelled block co-polymers were further assembled into polyion complex micelle nanoparticles and crosslinked through amide bond formation to form stable nano-scaffolds for ligand attachment. Cell binding and lysosome trafficking was determined in live cells by fluorescence imaging in 96-well plates and quantification of red- and green-fluorescence signals over time. The platform and assay was validated for selection of optimal antibody-derived targeting ligands directed towards CD22 for nanoparticle delivery. Kinetic analysis of uptake and lysosome trafficking indicated differences between ligand types and the ligand with the highest lysosome trafficking efficiency translated into effective DNA delivery with nanoparticles bearing the optimal ligand.

Abstract RNA binding proteins (RBPs) act as critical facilitators of spatially regulated gene expression. Muscleblind-like (MBNL) proteins, implicated in myotonic dystrophy and cancer, localize RNAs to myoblast membranes and neurites through unknown mechanisms. We find that MBNL forms motile and anchored granules in neurons and myoblasts, and selectively associates with kinesins Kif1bα and Kif1c through its zinc finger (ZnF) domains. Other RBPs with similar ZnFs associate with these kinesins, implicating a motor-RBP specificity code. MBNL and kinesin perturbation leads to widespread mRNA mis-localization, including depletion of Nucleolin transcripts from neurites. Live cell imaging and fractionation reveal that the unstructured carboxy-terminal tail of MBNL1 allows for anchoring at membranes. An approach, termed RBP Module Recruitment and Imaging (RBP-MRI), reconstitutes kinesin- and membrane-recruitment functions using MBNL-MS2 coat protein fusions. Our findings decouple kinesin association, RNA binding, and membrane anchoring functions of MBNL while establishing general strategies for studying multi-functional, modular domains of RBPs.

Productivity is a primary indicator when assessing plant communities or their responses to various stimuli, but it can be difficult and costly to determine. Adding to this complication is the retention of standing litter from previous years’ growth intermingled with current-year biomass. The most accurate and commonly applied method for estimating productivity is to clip and manually sort vegetation to separate current-year and previous years’ growth. Because sorting is costly, it is often only done for subsamples or not done at all. Without accounting for previous years’ growth, productivity estimates will be biased upward for conditions that accumulate more standing dead material, which is problematic when comparing treatments such as fire or different levels of herbivory. We tested whether line-point intercept methods could be adapted to determine proportions of current-year and older vegetation and estimate current-year biomass directly or by calculating the product of percent current-year intercepts and total standing crop. Data were collected by seven observers across four years and five experiments in northern mixed prairie using a total of 306 plots. Point-intercept transects with 20-cm spacing between points were used to determine number of intercepts for current-year and older vegetation and compared with data derived by clipping, manually sorting and weighing herbaceous vegetation. Regression analyses were used to test relationships between 1) total standing crop and total point intercepts; 2) current-year biomass and current-year point intercepts; 3) percent current-year biomass based on manual sorting versus point intercept methods; and 4) sorted current-year biomass and point intercept-derived current-year biomass. Number of intercepts per 100 points was positively related to total standing crop and current-year biomass, but r2 values were only 0.49 and 0.53. The relationship between manually-sorted current-year biomass and that derived from the product of point-intercept percentages and total standing crop was positive, explained 96 % of the variation, and had a mean absolute error of 122 kg ha−1. Point-intercept sampling is more efficient than manual sorting and can provide more indicators, including cover and diversity. Data indicate point intercept methods are accurate and can replace manual sorting of current-year herbaceous biomass.

A new aim for grassland management is to increase soil organic carbon (SOC) and to offset CO2 emissions by companies. This practice of carbon ranching may be informed by grazing-induced shifts in plant biomass and diversity which may foretell changes in SOC. Unfortunately, little is known about how grazing-induced shifts in plant properties correspond with shifts in SOC stocks. To help fill this gap, we used data from a field experiment to test whether above-ground plant properties (i.e. biomass, species richness) act as leading indicators of grazing-induced SOC accrual in the Northern Great Plains. The 5-yr bovine grazing experiment had a randomized complete block design and pre-treatment data. Moderate summer grazing (control) is widely used in the Northern Great Plains, and treatments that may alter grassland vegetation and SOC included: severe summer grazing, moderate fall grazing, and severe fall grazing. Severe fall and summer grazing increased SOC but had no effect on plant species richness and biomass relative to controls. Fall moderate grazing increased above-ground plant biomass but had no effect on SOC relative to controls. Changes to grazing practices can affect SOC without measurably affecting plant properties and can affect plant properties without measurably affecting SOC. While two drivers of SOC are plant carbon inputs and microbial respiration, our study indicates that grazing-induced change in above-ground vegetation is not predictive of change in SOC.

The purpose of this study was to assess organ dosimetry and clinical use of [124I]I-NM404, a radiotheranostic alkylphosphocholine (APC) analog, for accurate detection and characterization of a wide variety of solid primary and metastatic malignancies anywhere in the body. Methods: Patterns of [124I]I-NM404 uptake were quantitatively analyzed and qualitatively compared with [18F]FDG PET/CT in 14 patients (median age, 61.5 years; 7 males, 7 females) with refractory metastatic cancer who were enrolled in one of two Phase I imaging studies. Primary cancer types included bronchogenic (n = 7), colorectal (n = 1), prostate (n = 1), triple-negative breast (n = 1), head and neck (n = 2), pancreatic (n = 1) carcinoma, and melanoma (n = 1). Patients were administered [124I]I-NM404 and imaged via PET/CT at 1–2, 4–6, 24, and 48 h and at 5–10 days post injection, from top of the skull to mid-thigh. Volumes of interest were drawn over lungs, heart, liver, kidneys, and whole body for dosimetry estimation using OLINDA 1.1 Representative metastatic index lesions were chosen when applicable for each case with active sites of disease to calculate maximum and mean tumor-to-background ratios (TBRmax, TBRmean), using the adjacent normal organ parenchyma as background when possible. Results: Administrations of [124I]-NM404 were safe and well-tolerated. The organs with the highest estimated absorbed dose (mean ± SD) were the lungs (1.74 ± 0.39 mSv/MBq), heart wall (1.52 ± 0.29 mSv/MBq), liver (1.28 ± 0.21 mSv/MBq) and kidneys (1.09 ± 0.20 mSv/MBq). The effective dose was 0.77 ± 0.05 mSv/MBq. Preferential uptake within metastatic foci was observed with all cancer subtypes, TBRmax ranged from 1.95 to 15.36 and TBRmean ranged from 1.63 to 6.63. Robust sensitive imaging of lesions was enhanced by delayed timing (2–6 days after single injection of [124I]I-NM404, respectively) due to persistent tumor retention coupled with progressive washout of background activity. NM404 uptake was evident in pulmonary, nodal, skeletal, CNS, and other metastatic sites of disease. Radiation related injury or necrosis were NM404 negative, whereas certain small number of metastatic brain lesions were false negative for NM404. Conclusions: In addition to being well tolerated, selective tumor uptake of NM404 with prolonged retention was demonstrated within a broad spectrum of highly treated metastatic cancers.

Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis-that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally.

LINE-1 (L1) is the only autonomously active retrotransposon in the human genome, and accounts for 17% of the human genome. The L1 mRNA encodes two proteins, ORF1p and ORF2p, both essential for retrotransposition. ORF2p has reverse transcriptase and endonuclease activities, while ORF1p is a homotrimeric RNA-binding protein with poorly understood function. Here, we show that condensation of ORF1p is critical for L1 retrotransposition. Using a combination of biochemical reconstitution and live-cell imaging, we demonstrate that electrostatic interactions and trimer conformational dynamics together tune the properties of ORF1p assemblies to allow for efficient L1 ribonucleoprotein (RNP) complex formation in cells. Furthermore, we relate the dynamics of ORF1p assembly and RNP condensate material properties to the ability to complete the entire retrotransposon life-cycle. Mutations that prevented ORF1p condensation led to loss of retrotransposition activity, while orthogonal restoration of coiled-coil conformational flexibility rescued both condensation and retrotransposition. Based on these observations, we propose that dynamic ORF1p oligomerization on L1 RNA drives the formation of an L1 RNP condensate that is essential for retrotransposition.

Competency-based education has become a defining characteristic of higher social work education. This movement provides ample opportunity for students to have transformative learning experiences that will prepare them for professional practice. Yet, scholarly work on competency-based education runs the risk of overlooking the important developmental processes associated with competency attainment. We propose conceptualizing competency as both process and outcome to fully realize the potential of transformative learning in competency-based education. To this end, we offer two teaching case examples. The first describes a recorded role-play assignment for promoting clinical judgment and skill in a master's level practice course. The second describes an assignment that uses photovoice to deepen undergraduate students' understandings of macrolevel practice. These approaches present possibilities for teaching strategies that support transformational learning by attending to processes as well as outcomes that will lead to competence in social work education.

Disturbance seasonality and return interval can create complex interactions of direct and indirect effects on species and ecosystems. Fire is a key grassland disturbance, yet long‐term research examining seasonality and return intervals is limited. A 15‐year experiment testing combinations of fire seasonality (summer, fall, spring) and return interval (2, 3, 6‐year) plus non‐burned controls was conducted in northern mixed prairie to evaluate effects on the plant community. Hesperostipa comata is a native C3 bunchgrass and dominant species in northern mixed prairie and previously observed to be fire‐sensitive. Current‐year aboveground biomass results were generally counter to expectations based on short‐term research. Fire increased H. comata biomass with a strong, rhythmic response pattern to a specific fire seasonality‐return‐interval combination (fall fire at 3‐year return intervals) that periodically increased biomass to more than three times that with no fire. Through the first four post‐fire growing seasons, biomass with summer, fall and spring fire across return intervals was 41, 89 and 93% of that with no fire. Afterward, no fire combination produced less biomass than no fire and recurring patterns emerged with large increases in biomass, particularly with fall fire at 3‐year intervals. Peak biomass years were regularly two growing seasons after 3‐year fall fire and occurred across wet, near‐average and dry conditions. We hypothesize that productivity responses were driven by the combination of demographic processes of seedling recruitment and synchronization of multiple tiller age classes. Because short‐term negative effects were reversed and regular patterns only emerged 5 years after study initiation, more long‐term research evaluating fire regimes is recommended to expand upon tests of individual factors over short periods. This suggestion is based on fire research, but likely applies to multiple forms of disturbance and demonstrates how demographic processes can inform responses for individual species and larger ecosystem functions, such as productivity. [ABSTRACT FROM AUTHOR]

Dendronized nanoparticles, also called nanoparticle-cored dendrimers, combine the advantages of nanoparticles and dendrimers. These very stable and polyvalent nanoparticles can be used for diverse applications. One such application is drug delivery, because the dendrons can enhance the density of the payload. In this report, we describe the design of multifunctional gold nanoparticles (AuNPs) coated with poly(propylene imine) (PPI) dendrons that contain both prostate cancer active targeting and chemotherapeutic drugs. The PPI dendron is a good candidate for the design of drug delivery vehicles because of its ability to induce a proton sponge effect that will enhance lysosomal escape and intracellular therapeutic delivery. The chemotherapeutic drug used is doxorubicin (DOX), and it was linked to the dendron through a hydrazone acid-sensitive bond. Subsequent acidification of the AuNP system to a pH of 4–5 resulted in the release of 140 DOX drugs per nanoparticles. In addition, the PPI dendron was conjugated via “click” chemistry to an EphA2-targeting antibody fragment that has been shown to target prostate cancer cells. In vitro cell viability assays revealed an IC50 of 0.9 nM for the targeted DOX-bearing AuNPs after 48 h incubation with PC3 cells. These results are very promising upon optimization of the system.

It is increasingly recognised that the spatial localisation of RNA is important for proper cellular function. Here, the authors investigate RNA localisation in skeletal muscle and develop methods to show that global active transport of RNA is required to maintain dispersion of gene products in the large muscle syncytium.

Abstract Background The study was conducted to prospectively examine how pregnancy intendedness and prenatal provider counseling about postpartum contraceptive options are associated with lack of contraception use at 6 months post-birth (e.g., increased risk for a short interpregnancy interval). Methods Logistic regression models were used to examine risk for no postpartum contraception use among a sample of low-income and racially/ethnically diverse women recruited from two metropolitan perinatal clinics in Tulsa, OK. Results Women who reported that they were trying to get pregnant or “okay either way” about getting pregnant had significantly lower odds of using contraception at 6 months post childbirth than those who had unintended pregnancies. Having providers who discussed postpartum contraceptive options during pregnancy significantly increased the odds of contraceptive uptake among those who were planning or ambivalent about their pregnancies. Conclusions Intentions of a current pregnancy and provider contraceptive counseling matter for postpartum contraceptive use and the associated risk for a short interval subsequent pregnancy. Provider contraceptive counseling that accounts for the intendedness of a current pregnancy may offer a more targeted approach to prevent a short interval subsequent pregnancy.

Abstract Little research has assessed how the timing and intensity of grazing might affect plant biomass, available nutrients, soil extracellular enzyme activity (EEA), and how climate change might influence these responses. We tested the effect of two spring precipitation schemes (70, 100% of ambient), two mowing intensities (moderate, severe), and two mowing season treatments (June, October) on plant and soil properties. We detected an interactive effect of precipitation, mowing intensity, and mowing season on plant biomass. When plots were mowed at a moderate intensity, water reductions had irregular effects on plant biomass depending on the mowing season. Plant biomass was also 11% greater in plots mowed at moderate than at severe intensities. Most soil nutrients were unaffected by treatments except for calcium. Soil EEA was unaffected by treatments; however, the activity of a phosphorus (P)‐acquisition enzyme was more than four times greater than the activity of nitrogen (N)‐ and carbon‐acquisition enzymes. A substantial amount (adjusted R2 = .51) of plot‐to‐plot variation in plant biomass was explained by three soil properties especially an N‐acquisition enzyme and to a lesser degree by plant available P and soil pH. The grassland had a high degree of natural buffering capacity as most soil properties were resistant to shifts in 6‐yr spring precipitation and 5‐yr simulated grazing intensity and season. Grassland plant biomass varied by treatments and was seemingly limited by biogeochemical constraints especially the prevalent need to mobilize P and a secondary need to acquire N as plant biomass increased.

Japanese brome (Bromus japonicus Thunb.) has been introduced to four continents from its Eurasian origins and has increased during recent decades, particularly in North America. Invasion of this C3 annual grass into rangelands diminishes native plant communities and hinders livestock performance. Control methods have been developed, but have proven short-lived. Japanese brome is positively correlated with plant litter and standing dead material, suggesting management of those components could be important. Objectives for this study were to isolate and quantify the effects of litter and standing dead on Japanese brome utilizing fall defoliation with four different mowing heights (10, 6, 4, or 1 cm) compared to a non-mowed control. Research was conducted on two ecological sites (silty and claypan) with each site consisting of 25 plots (5.5 × 1.6-m). This study was conducted over 4 yr (2013–2017) and fall mowing reduced old dead mass every year except 2016, which followed a severe drought. Spring soil water was not reduced by fall defoliation. Mowing to 1 cm reduced brome biomass by 40% compared to non-mowed plots and brome production was highly dependent on Sep-Oct precipitation. Brome biomass was least in 2015 during a drought and greatest in 2017 following double the median Sep-Oct precipitation. Non-brome biomass was similar across treatments. An 11% reduction in current-year biomass was observed for mowing heights of 10, 6, and 4 cm whereas a 22% reduction was measured for the 1 cm mowing height compared to non-mowed plots. Perennial grass basal cover was similar for 10, 6, and 4 cm mowing heights and greater than that for mowing at 1 cm whereas, no differences were detected between non-mowed plots and any mowing height. Increasing fall defoliation intensity reduced annual bromes while allowing perennial grasses to persist, indicating fall mowing and possibly grazing are viable options for annual brome management.

Large planetary seedlings, comets, microscale pharmaceuticals, and nanoscale soot particles are made from rigid, aggregated subunits that are compacted under low compression into larger structures spanning over 10 orders of magnitude in dimensional space. Here, we demonstrate that the packing density (θf) of compacted rigid aggregates is independent of spatial scale for systems under weak compaction. The θf of rigid aggregated structures across six orders of magnitude were measured using nanoscale spherical soot aerosol composed of aggregates with ∼ 17-nm monomeric subunits and aggregates made from uniform monomeric 6-mm spherical subunits at the macroscale. We find θf = 0.36 ± 0.02 at both dimensions. These values are remarkably similar to θf observed for comet nuclei and measured values of other rigid aggregated systems across a wide variety of spatial and formative conditions. We present a packing model that incorporates the aggregate morphology and show that θf is independent of both monomer and aggregate size. These observations suggest that the θf of rigid aggregates subject to weak compaction forces is independent of spatial dimension across varied formative conditions.

Abstract Background Skeletal muscle contributes to roughly 40% of lean body mass, and its loss contributes to morbidity and mortality in a variety of pathogenic conditions. Significant insights into muscle function have been made using cultured cells, in particular, the C2C12 myoblast line. However, differentiation of these cells in vitro typically yields immature myotubes relative to skeletal muscles in vivo. While many efforts have attempted to improve the maturity of cultured myotubes, including the use of bioengineered substrates, lack of molecular characterization has precluded their widespread implementation. This study characterizes morphological, molecular, and transcriptional features of C2C12 myotubes cultured on crosslinked, micropatterned gelatin substrates fabricated using previously established methods and compares them to myotubes grown on unpatterned gelatin or traditional plasticware. Methods We used immunocytochemistry, SDS-PAGE, and RNAseq to characterize C2C12 myotubes grown on micropatterned gelatin hydrogels, unpatterned gelatin hydrogels, and typical cell culture substrates (i.e., plastic or collagen-coated glass) across a differentiation time course. The ability to form aligned sarcomeres and myofilament protein concentration was assessed. Additionally, the transcriptome was analyzed across the differentiation time course. Results C2C12 myotubes grown on micropatterned gelatin hydrogels display an increased ability to form aligned sarcomeres as well as increased contractile protein content relative to myotubes cultured on unpatterned gelatin and plastic. Additionally, genes related to sarcomere formation and in vivo muscle maturation are upregulated in myotubes grown on micropatterned gelatin hydrogels relative to control myotubes. Conclusions Our results suggest that growing C2C12 myotubes on micropatterned gelatin hydrogels accelerates sarcomere formation and yields a more fully matured myotube culture. Thus, the use of micropatterned hydrogels is a viable and simple approach to better model skeletal muscle biology in vitro.