Genotype and Genotype X Environment Interaction Effects on Forage Yield and Quality of Crested Wheatgrasses

Genotype, environment, and genotype X environment interaction effects for forage yield and quality of the crested wheatgrasses (Agropyron cristatum) and (A. desertorum) were studied using an array of 42 crested wheatgrass introductions, experimental lines, and released cultivars that were selected to be representative of the mix of germplasm available to a breeder. They were grown in two environments, Lincoln and Alliance, Nebr., that differ markedly in climate. Forage yield and forage quality as measured by in vitro dry matter digestibility (IVDMD) and percent protein were determined in both locations in 1980 and 1981. In the combined analyses over years and locations, there were significant differences among strains or genotypes and locations for first-harvest forage yield, IVDMD, and protein. Strain X location interaction effects were significant only for first-harvest forage yield and for this trait its variance component was only 0.3 as large as the variance component for strains. Strain X year interaction effects were not significant. Spearmen correlations, used to show relative ranking of the strains at the two locations, were moderate and positive for all first-cut traits. The results indicate that existing genetic variability in forage yield and quality should permit the development of improved crested wheatgrasses and that at least in the initial stages of a breeding program, selection for these traits could be done in a single location and year

Genotype and Genotype X Environment Interaction Effects on Forage Yield and Quality of Crested Wheatgrasses

Genotype, environment, and genotype X environment interaction effects for forage yield and quality of the crested wheatgrasses (Agropyron cristatum) and (A. desertorum) were studied using an array of 42 crested wheatgrass introductions, experimental lines, and released cultivars that were selected to be representative of the mix of germplasm available to a breeder. They were grown in two environments, Lincoln and Alliance, Nebr., that differ markedly in climate. Forage yield and forage quality as measured by in vitro dry matter digestibility (IVDMD) and percent protein were determined in both locations in 1980 and 1981. In the combined analyses over years and locations, there were significant differences among strains or genotypes and locations for first-harvest forage yield, IVDMD, and protein. Strain X location interaction effects were significant only for first-harvest forage yield and for this trait its variance component was only 0.3 as large as the variance component for strains. Strain X year interaction effects were not significant. Spearmen correlations, used to show relative ranking of the strains at the two locations, were moderate and positive for all first-cut traits. The results indicate that existing genetic variability in forage yield and quality should permit the development of improved crested wheatgrasses and that at least in the initial stages of a breeding program, selection for these traits could be done in a single location and year

A frictionless microswimmer

We investigate the self-locomotion of an elongated microswimmer by virtue of the unidirectional tangential surface treadmilling. We show that the propulsion could be almost frictionless, as the microswimmer is propelled forward with the speed of the backward surface motion, i.e. it moves throughout an almost quiescent fluid. We investigate this swimming technique using the special spheroidal coordinates and also find an explicit closed-form optimal solution for a two-dimensional treadmiler via complex-variable techniques.Comment: 6 pages, 4 figure

Antinociceptive Effects of Herkinorin, a MOP Receptor Agonist Derived from Salvinorin A in the Formalin Test in Rats: New Concepts in Mu Opioid Receptor Pharmacology

Herkinorin is the first μ opioid (MOP) selective agonist derived from salvinorin A, a hallucinogenic natural product. Previous work has shown that, unlike other opioids, herkinorin does not promote the recruitment of β-arrestin-2 to the MOP receptor and does not lead to receptor internalization. This paper presents the first in vivo evaluation of herkinorin’s antinociceptive effects in rats, using the formalin test as a model of tonic inflammatory pain. Herkinorin was found to produce a dose-dependent decrease in the number of flinches evoked by formalin. These antinociceptive effects were substantially blocked by pretreatment with the nonselective antagonist naloxone, indicating that the antinociception is mediated by opioid receptors. Contralateral administration of herkinorin did not attenuate the number of flinches evoked by formalin, indicating that its effects are peripherally restricted to the site of injection. Following chronic administration (5-day), herkinorin maintained antinociceptive efficacy in both phases of the formalin test. Furthermore, unlike morphine, herkinorin was still able to inhibit flinching in both phases of the formalin test in animals made tolerant to chronic systemic morphine treatment. Collectively, these results suggest that herkinorin may produce peripheral antinociception with decreased tolerance liability and thereby represents a promising template for the development of agents for the treatment of a variety of pain states

Development of a Colon Cancer GEMM-Derived Orthotopic Transplant Model for Drug Discovery and Validation

Purpose: Effective therapies for KRAS-mutant colorectal cancer (CRC) are a critical unmet clinical need. Previously, we described genetically engineered mouse models (GEMM) for sporadic Kras-mutant and non-mutant CRC suitable for preclinical evaluation of experimental therapeutics. To accelerate drug discovery and validation, we sought to derive low-passage cell lines from GEMM Kras-mutant and wild-type tumors for in vitro screening and transplantation into the native colonic environment of immunocompetent mice for in vivo validation. Experimental Design: Cell lines were derived from Kras-mutant and non-mutant GEMM tumors under defined media conditions. Growth kinetics, phosphoproteomes, transcriptomes, drug sensitivity, and metabolism were examined. Cell lines were implanted in mice and monitored for in vivo tumor analysis. Results: Kras-mutant cell lines displayed increased proliferation, mitogen-activated protein kinase signaling, and phosphoinositide-3 kinase signaling. Microarray analysis identified significant overlap with human CRC-related gene signatures, including KRAS-mutant and metastatic CRC. Further analyses revealed enrichment for numerous disease-relevant biologic pathways, including glucose metabolism. Functional assessment in vitro and in vivo validated this finding and highlighted the dependence of Kras-mutant CRC on oncogenic signaling and on aerobic glycolysis. Conclusions: We have successfully characterized a novel GEMM-derived orthotopic transplant model of human KRAS-mutant CRC. This approach combines in vitro screening capability using low-passage cell lines that recapitulate human CRC and potential for rapid in vivo validation using cell line-derived tumors that develop in the colonic microenvironment of immunocompetent animals. Taken together, this platform is a clear advancement in preclinical CRC models for comprehensive drug discovery and validation efforts

Understanding and improving model representation of aerosol optical properties for a Chinese haze event measured during KORUS-AQ

KORUS-AQ was an international cooperative air quality field study in South Korea that measured local and remote sources of air pollution affecting the Korean Peninsula during May–June 2016. Some of the largest aerosol mass concentrations were measured during a Chinese haze transport event (24 May). Air quality forecasts using the WRF-Chem model with aerosol optical depth (AOD) data assimilation captured AOD during this pollution episode but overpredicted surface particulate matter concentrations in South Korea, especially PM2.5, often by a factor of 2 or larger. Analysis revealed multiple sources of model deficiency related to the calculation of optical properties from aerosol mass that explain these discrepancies. Using in situ observations of aerosol size and composition as inputs to the optical properties calculations showed that using a low-resolution size bin representation (four bins) underestimates the efficiency with which aerosols scatter and absorb light (mass extinction efficiency). Besides using finer-resolution size bins (8–16 bins), it was also necessary to increase the refractive indices and hygroscopicity of select aerosol species within the range of values reported in the literature to achieve better consistency with measured values of the mass extinction efficiency (6.7 m2 g−1 observed average) and light-scattering enhancement factor (f(RH)) due to aerosol hygroscopic growth (2.2 observed average). Furthermore, an evaluation of the optical properties obtained using modeled aerosol properties revealed the inability of sectional and modal aerosol representations in WRF-Chem to properly reproduce the observed size distribution, with the models displaying a much wider accumulation mode. Other model deficiencies included an underestimate of organic aerosol density (1.0 g cm−3 in the model vs. observed average of 1.5 g cm−3) and an overprediction of the fractional contribution of submicron inorganic aerosols other than sulfate, ammonium, nitrate, chloride, and sodium corresponding to mostly dust (17 %–28 % modeled vs. 12 % estimated from observations). These results illustrate the complexity of achieving an accurate model representation of optical properties and provide potential solutions that are relevant to multiple disciplines and applications such as air quality forecasts, health impact assessments, climate projections, solar power forecasts, and aerosol data assimilation

Secondary organic aerosol production from local emissions dominates the organic aerosol budget over Seoul, South Korea, during KORUS-AQ

Organic aerosol (OA) is an important fraction of submicron aerosols. However, it is challenging to predict and attribute the specific organic compounds and sources that lead to observed OA loadings, largely due to contributions from secondary production. This is especially true for megacities surrounded by numerous regional sources that create an OA background. Here, we utilize in situ gas and aerosol observations collected on board the NASA DC-8 during the NASA–NIER KORUS-AQ (Korea–United States Air Quality) campaign to investigate the sources and hydrocarbon precursors that led to the secondary OA (SOA) production observed over Seoul. First, we investigate the contribution of transported OA to total loadings observed over Seoul by using observations over the Yellow Sea coupled to FLEXPART Lagrangian simulations. During KORUS-AQ, the average OA loading advected into Seoul was ∼1–3 µg sm−3. Second, taking this background into account, the dilution-corrected SOA concentration observed over Seoul was ∼140 µgsm−3ppmv−1 at 0.5 equivalent photochemical days. This value is at the high end of what has been observed in other megacities around the world (20–70 µgsm−3ppmv−1 at 0.5 equivalent days). For the average OA concentration observed over Seoul (13 µg sm−3), it is clear that production of SOA from locally emitted precursors is the major source in the region. The importance of local SOA production was supported by the following observations. (1) FLEXPART source contribution calculations indicate any hydrocarbons with a lifetime of less than 1 day, which are shown to dominate the observed SOA production, mainly originate from South Korea. (2) SOA correlated strongly with other secondary photochemical species, including short-lived species (formaldehyde, peroxy acetyl nitrate, sum of acyl peroxy nitrates, dihydroxytoluene, and nitrate aerosol). (3) Results from an airborne oxidation flow reactor (OFR), flown for the first time, show a factor of 4.5 increase in potential SOA concentrations over Seoul versus over the Yellow Sea, a region where background air masses that are advected into Seoul can be measured. (4) Box model simulations reproduce SOA observed over Seoul within 11 % on average and suggest that short-lived hydrocarbons (i.e., xylenes, trimethylbenzenes, and semi-volatile and intermediate-volatility compounds) were the main SOA precursors over Seoul. Toluene alone contributes 9 % of the modeled SOA over Seoul. Finally, along with these results, we use the metric ΔOA/ΔCO2 to examine the amount of OA produced per fuel consumed in a megacity, which shows less variability across the world than ΔOA∕ΔCO