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A goal of the cooperative agreement between the U.S. Food and Drug Administration and the Center for Tobacco Reference Products (CTRP) at the University of Kentucky was to produce a standard reference cigarette for researchers to further tobacco science. The 1R6F certified reference cigarette for analytical testing was developed to be typical of an American blend cigarette. The cigarettes have been used in proficiency testing (PT) schemes under the supervision of the CTRP since 2016 for a variety of parameters. Data were compared from 8 rounds of PT schemes submitted by participating laboratories, which include various international stakeholders comprised of academic institutions, federal research/regulatory laboratories, tobacco product manufacturers, and independent contract testing laboratories. Evaluation of the datasets for harmful and potentially harmful constituents (HPHCs) within the mainstream smoke of the 1R6F certified reference cigarette included tobacco-specific nitrosamines (TSNA), tar, nicotine, and carbon monoxide (TNCO), and Benzo[α]pyrene (BαP). Of the datasets evaluated, less than 5 % resulted in either a warning or alert, and less than 2 % resulted in an alert. Comparisons across multiple PT rounds revealed no significant differences in the consensus means of the tested parameters. Evaluation of data submitted by participating laboratories for multiple proficiency test rounds shows that the 1R6F certified reference cigarette is an acceptable material as a control reference for the analysis of HPHCs which is imperative since some stakeholders may be required to participate in, and receive satisfactory results, from PT for accreditation purposes.

Summary 4-(N’-methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potentially carcinogenic tobacco specific nitrosamine (TSNA) and an important compound in the Harmful and Potentially Harmful Constituents (HPHCs) list of U.S. Food and Drug Administration (FDA). For this reason, significant effort is being made for an understanding of the formation of this compound and for the reduction of its level in tobacco products. Formation of NNK is assumed to be the result of nitrosation of 4-(methylamino)-1-(3-pyridyl)-1-butanone (pseudooxynicotine or PON). Present study evaluated the correlation between the levels of NNK and those of PON in a variety of tobaccos and tobacco products. Since nicotine-1′-N-oxide can be involved in the formation of PON, the correlation of the levels of this compound with the levels of NNK was also evaluated. Two original methods were developed for the quantitation of PON in tobacco and tobacco products and a well-established method has been used for the analysis of NNK. The correlation between the levels of NNK with that of PON was proven to be very poor. The same result was obtained for the correlation between NNK levels and nicotine-1′-N-oxide. This indicated that a higher level of PON or of nicotine-1′-N-oxide in tobacco or tobacco products does not lead to a higher level of NNK. The study does not prove that NNK in tobacco or tobacco products is not generated via PON, but it demonstrated that the limiting factor in the formation of NNK in tobacco and tobacco products is not the level of PON or that of nicotine-1′-N-oxide, and other factors are responsible for the effectiveness of NNK formation.

Ergovaline (ERV), produced in toxic endophyte-infected tall fescue, causes potent vasoconstriction of bovine peripheral and visceral vasculature. Ergovaline acts as both an agonist and an antagonist in bovine gut blood vessels through serotonin (5-HT) receptors and it appears that the type of action could be influenced by the extent of ERV exposure. Because it was unclear how the duration of ERV exposure influences 5-HT-mediated vasoactivity, experiments were designed to evaluate how simultaneous or prior ERV exposure influenced 5-HT-mediated vasoactivity of mesenteric artery (MA) and vein (MV) segments from Holstein steers (N = 10). Vessels were incubated in Krebs–Henseleit buffer containing 0, 0.01, or 0.1 μM ERV for 24 h prior to the 5-HT dose-response or exposed to fixed concentrations of 0, 0.01, or 0.1 μM ERV simultaneously during the 5-HT dose-response. Vessels were suspended in chambers of a multimyograph containing Krebs–Henseleit buffer and equilibrated to 1 g tension for 90 min. Vessels were exposed to increasing concentrations of 5-HT (5 × 10−8 M to 1 × 10−4 M) every 15 min and contractile responses were normalized as a percentage of the maximum contractile response induced by 120 mM KCl reference addition. Two-way analysis of variance was used to separately analyze data for each vessel type and duration of exposure using the MIXED procedure of SAS. When 5-HT concentration increased from 5 × 10−8 to 1 × 10−6 M, simultaneous addition of 0.1 μM ERV increased (P < 0.01) the contractile response of MV compared with additions of 0 and 0.01 μM ERV. At 1 × 10−4 M 5-HT, the simultaneous presence of 0.01 and 0.1 μM ERV decreased (P < 0.01) the contractile response of both MA and MV compared with 0 μM ERV addition. As 5-HT concentrations increased, the contractile response increased (P < 0.01) in both MA and MV with no previous ERV exposure, but decreased in MA and MV with 24 h prior exposure to 0.01 and 0.1 μM ERV. These data demonstrate that the duration of ERV exposure influences 5-HT-mediated vasoconstriction and likely vasorelaxation in bovine mesenteric vasculature. If ERV and 5-HT exposure occur simultaneously, ERV can act as a partial agonist of 5-HT-mediated vasoconstriction. If 5-HT exposure occurs after blood vessels have had prior ERV exposure, it appears that 5-HT may induce vasorelaxation of blood vessels. More research is needed to identify cellular and molecular mechanisms involved with 5-HT-mediated vasoactivity.

Smokeless tobacco (ST) products are used worldwide, and consumption is increasing in the USA. Although ST products are considered to occupy a different position on the tobacco product continuum of risk compared to combusted tobacco products, they can still lead to health problems, including cancer, dental problems and changes in heart rate and blood pressure. Therefore, the determination of harmful and potentially harmful constituents released from ST products into human saliva is important. Four certified reference ST products were tested in this study: loose leaf chewing tobacco (3S1), Swedish-style snus (1S4), snus (1S5) and moist snuff (3S3). These certified reference ST products are manufactured for research purposes, not for human consumption. The reference ST products were used in this study because they have been well characterized and are intended and designed to represent commercial ST products. The reference ST products were incubated in human saliva at 37°C with a range of incubation times for the evaluation of constituents released from these products into human saliva. In this study, alkaloids (nicotine and cotinine), tobacco-specific N-nitrosamines (TSNAs) (N’-nitrosornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) and benzo[α]pyrene (B[α]P) in the reference ST products and saliva samples were determined by gas chromatography--mass spectrometry (GC--MS), gas chromatography--flame ionization detection (GC--FID), or ultra-performance liquid chromatography--tandem mass spectrometry (UPLC--MS-MS). Our results indicate that the amounts of each constituent released from the reference ST products were altered by the tobacco cut size and product format (pouched or unpouched). The constituents (TSNAs and alkaloids) in moist snuff and loose leaf chewing tobacco were released faster compared to those in Swedish-style snus and snus. B[α]P was only detected in reference moist snuff samples, and only 3.4% of the total B[α]P was released into human saliva after incubation for 60 min, whereas higher percentages of total TSNAs and alkaloids were released at different rates from the four reference ST products.

Aromatic amines are a class of carcinogenic compounds in tobacco smoke that are listed on the FDA list of harmful and potentially harmful constituents (HPHCs). A method using solid-phase microextraction-coupled to gas chromatography-triple quadrupole mass spectrometry (SPME headspace GC–MS/MS) was developed and validated for the quantitative determination of six aromatic amines, including 1-aminonaphthalene (1-AN), 2-aminonaphthalene (2-AN), 3-aminobiphenyl (3-ABP), 4-aminobiphenyl (4-ABP), o-toluidine (o-TOL), and o-anisidine (o-ANI), in the mainstream smoke of cigarettes, cigars, and heated tobacco products. The method developed here combines high sensitivity with simple sample preparation and has demonstrated satisfactory linearity for all six aromatic amines with correlation coefficients greater than 0.9994. The limits of detection range and the limits of quantitation range were 12–96 pg/mL and 41–320 pg/mL, respectively. Their recoveries and coefficients of variation (CV%) were 90–112% and 2.1–6.6%, respectively. The new SPME headspace GC/MS/MS method has been successfully applied to measure the contents of the six aromatic amines in the mainstream smoke of cigarettes, cigars, and heated tobacco products.

Decreased blood flow caused by vasoconstriction is a hallmark of ergot alkaloid exposure. Previous research has utilized the cranial branch of the lateral saphenous vein as a model to characterize the impact of ergot alkaloids on bovine peripheral vasculature. The digital vein is more distal and closer to the hoof where damage caused by vasoconstriction occurs and may be more sensitive to ergot alkaloids. Thus, the objective was to compare contractility of the bovine lateral saphenous vein and the digital vein to increasing concentrations of ergot alkaloids. Blood vessels were collected from Holstein steers at slaughter (n = 12; 551 ±29 kg), cleaned, cut into 2-mm cross-sections, and mounted in a multi-myograph. In the myograph blood vessels were submersed in continuously gassed (95% O2/5% CO2) Krebs-Henseleit buffer. Following a 1.5-hr tension equilibration, blood vessels were exposed to a reference dose of 1x10-4 M norepinephrine. Digital and lateral saphenous veins from each steer were then exposed to increasing concentrations of a-ergocryptine (ERP), ergotamine (ERT), ergocristine (ERS), ergocornine (ERO), ergonovine (ERN), tall fescue seed extract (EXT; dilutions based on measured ergovaline concentration), lysergic acid (LSA), and lysergol (LYS) were diluted to final concentrations for use in the tissue bath of 5x10-10 to 1x10-4 M. All resultant contractile response data were normalized as a percentage of the 1x10-4 M norepinephrine response and analyzed as randomized design for effects of vein and alkaloid concentration. The maximal contractile response induced by EXT, ERT, ERO, ERS, and ERP did not differ by vein type and EXT was the most vasoactive alkaloid. The response to ERN was greater for the saphenous than the digital vein (P = 0.03) and LYS and LSA did not differ (P >0.05). These data confirm that the cranial branch of lateral saphenous vein is a representative model of peripheral vasculature of the bovine hindlimb.

Fescue toxicosis impacts beef cattle production via reductions in weight gain and muscle development. Isoflavone supplementation has displayed potential for mitigating these effects. The objective of the current study was to evaluate isoflavone supplementation with fescue seed consumption on rumen and serum metabolomes. Angus steers (n = 36) were allocated randomly in a 2 &times, 2 factorial arrangement of treatments including endophyte-infected (E+) or endophyte-free (E&minus, ) tall fescue seed, with (P+) or without (P&minus, ) isoflavones. Steers were provided a basal diet with fescue seed for 21 days, while isoflavones were orally administered daily. Following the trial, blood and rumen fluid were collected for metabolite analysis. Metabolites were extracted and then analyzed by UPLC-MS. The MAVEN program was implemented to identify metabolites for MetaboAnalyst 4.0 and SAS 9.4 statistical analysis. Seven differentially abundant metabolites were identified in serum by isoflavone treatment, and eleven metabolites in the rumen due to seed type (p &lt, 0.05). Pathways affected by treatments were related to amino acid and nucleic acid metabolism in both rumen fluid and serum (p &lt, 0.05). Therefore, metabolism was altered by fescue seed in the rumen, however, isoflavones altered metabolism systemically to potentially mitigate detrimental effects of seed and improve animal performance.

Tobacco-specific nitrosamines (TSNAs) are carcinogens that accumulate in tobacco leaves during curing, storage, and processing, and their amounts in processed tobacco vary dependent on several intrinsic and extrinsic factors. Here, we assessed the hypothesis that there is a link between reactive oxygen species levels in leaves and TSNA formation during curing. First, we show that burley varieties KT 204LC and NCBH 129LC accumulate TSNAs to different levels but not as a result of a variety-specific abundance of TSNA precursors. Next, we measured the levels of reactive oxygen species, and we show that the variety that accumulates more TSNAs, NCBH 129LC, had significantly higher levels of hydrogen peroxide than KT 204LC. The NCBH 129LC also has more oxidatively damaged and glutathionylated proteins. Finally, we analyzed the antioxidant levels in KT 204LC and NCBH 129LC and their tolerance to oxidative stress. NCBH 129LC contained more of the essential antioxidant glutathione and was more tolerant to the oxidative stress-generating compound paraquat. Collectively, our data suggest that there is indeed a link between foliar oxidative stress parameters and the extent to which TSNAs accumulate in cured tobacco leaves.

The objectives of this study were to evaluate degradation of ergovaline in a tall fescue [ (Schreb.) Darbysh.] seed extract by rumen microbiota ex vivo and to identify specific bacteria capable of ergovaline degradation in vitro. Rumen cell suspensions were prepared by harvesting rumen fluid from fistulated wether goats ( = 3), straining, and differential centrifugation. Suspensions were dispensed into anaerobic tubes with added Trypticase with or without extract (∼10 μg kg ergovaline). Suspensions were incubated for 48 h at 39°C. Samples were collected at 0, 24, and 48 h for ergovaline analysis and enumeration of hyper-ammonia producing (HAB) and tryptophan-utilizing bacteria. Ergovaline values were analyzed by repeated measures using the mixed procedure of SAS. Enumeration data were log transformed for statistical analysis. When suspensions were incubated with extract, 11 to 15% of ergovaline disappearance was observed over 48 h ( = 0.02). After 24 h, suspensions with added extract had 10-fold less HAB than controls ( = 0.04), but treatments were similar by 48 h ( = 1.00). However, after 24 h and 48 h, suspensions with extract had 10-fold more tryptophan-utilizing bacteria ( < 0.01) that were later isolated and identified by their 16S RNA gene sequence as . The isolates and other known rumen pure cultures ( JB1, B159, HD4, B, F, MD1, SR) were evaluated for the ability to degrade ergovaline in vitro. Pure culture cell suspensions were incubated as described above and samples were taken at 0 and 48 h for ergovaline analysis. Data were analyzed using the ANOVA procedure of SAS. All HAB, including the isolates, tested degraded ergovaline (54 to 75%; < 0.05). B14 was also able to degrade ergovaline but to a lesser capacity (12%; < 0.05), but all other bacteria tested did not degrade ergovaline. The results of this study indicate which rumen bacteria may play an important role in ergovaline degradation and that microbiological strategies for controlling their activity could have ramifications for fescue toxicosis and other forms of ergotism in ruminants.

Nʹ-Nitrosonornicotine (NNN), a carcinogenic tobacco-specific Nʹ-nitrosamine (TSNA), is on the FDA list of harmful and potentially harmful constituents (HPHCs). Nornicotine, a product of the demethylation of nicotine, is the immediate alkaloid precursor for NNN formation. Nicotine, nornicotine and NNN are optically active. The accumulation of the isomers of nicotine, nornicotine, and NNN impacts their biological activity. In this paper, we report the determination of tobacco alkaloid enantiomers (including nicotine, nornicotine, anabasine, and anatabine) in samples of different tobacco lines using a reversed phase ultra-performance liquid chromatography-tandem mass spectrometer (UPLC/MS/MS) method. Current method demonstates excellent detection capability for all alkaloid enantiomers, with correlation coefficients (r2) > 0.996 within their linear dynamic ranges. The limit of detection (LOD) and limit of quantitation (LOQ) of all analytes are less than 10 ng/mL and 30 ng/mL, respectively. In addition, their recovery and coefficient of variation (CV%) are within 100–115% and 0.2–3.7%, respectively. The method validated in this paper is simple, fast, and sensitive for the quantification of alkaloid enantiomers in tobacco leaf and has been applied to investigations of tobacco alkaloid enantiomer ratios in different tobacco lines and tobacco products.

The MADS box transcription factor Arabidopsis (Arabidopsis thaliana) AGAMOUS-LIKE15 (AGL15) and a putative ortholog from soybean (Glycine max), GmAGL15, are able to promote somatic embryogenesis (SE) in these plants when ectopically expressed. SE is an important means of plant regeneration, but many plants, or even particular cultivars, are recalcitrant for this process. Understanding how (Gm)AGL15 promotes SE by identifying and characterizing direct and indirect downstream regulated genes can provide means to improve regeneration by SE for crop improvement and to perform molecular tests of genes. Conserved transcription factors and the genes they regulate in common between species may provide the most promising avenue to identify targets for SE improvement. We show that (Gm)AGL15 negatively regulates auxin signaling in both Arabidopsis and soybean at many levels of the pathway, including the repression of AUXIN RESPONSE FACTOR6 (ARF6) and ARF8 and TRANSPORT INHIBITOR RESPONSE1 as well as the indirect control of components via direct expression of a microRNA-encoding gene. We demonstrate interaction between auxin and gibberellic acid in the promotion of SE and document an inverse correlation between bioactive gibberellic acid and SE in soybean, a difficult crop to transform. Finally, we relate hormone accumulation to transcript accumulation of important soybean embryo regulatory factors such as ABSCISIC ACID INSENSITIVE3 and FUSCA3 and provide a working model of hormone and transcription factor interaction in the control of SE.

Summary Burley tobaccos (Nicotiana tabacum) display a nitrogen‐use‐deficiency phenotype that is associated with the accumulation of high levels of nitrate within the leaf, a trait correlated with production of a class of compounds referred to as tobacco‐specific nitrosamines (TSNAs). Two TSNA species, 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone (NNK) and N‐nitrosonornicotine (NNN), have been shown to be strong carcinogens in numerous animal studies. We investigated the potential of molecular genetic strategies to lower nitrate levels in burley tobaccos by overexpressing genes encoding key enzymes of the nitrogen‐assimilation pathway. Of the various constructs tested, only the expression of a constitutively active nitrate reductase (NR) dramatically decreased free nitrate levels in the leaves. Field‐grown tobacco plants expressing this NR variant exhibited greatly reduced levels of TSNAs in both cured leaves and mainstream smoke of cigarettes made from these materials. Decreasing leaf nitrate levels via expression of a constitutively active NR enzyme represents an exceptionally promising means for reducing the production of NNN and NNK, two of the most well‐documented animal carcinogens found in tobacco products.

Negative impacts of endophyte-infectedLolium arundinaceum (Darbyshire)(tall fescue) are responsible for over $2 billion in losses to livestock producers annually. While the influence of endophyte-infected tall fescue has been studied for decades, mitigation methods have not been clearly elucidated. Isoflavones found inTrifolium pretense(red clover) have been the subject of recent research regarding tall fescue toxicosis mitigation. Therefore, the aim of this study was to determine the effect of ergovaline and red clover isoflavones on rumen microbial populations, fiber degradation, and volatile fatty acids (VFA) in anin vitrosystem. Using a dose of 1.10 mg × L−1, endophyte-infected or endophyte-free tall fescue seed was added to ANKOM fiber bags with or without 2.19 mg of isoflavones in the form of a control, powder, or pulverized tablet, resulting in a 2 × 3 factorial arrangements of treatments. Measurements of pH, VFA, bacterial taxa, as well as the disappearance of neutral detergent fiber (aNDF), acid detergent fiber (ADF), and crude protein (CP) were taken after 48 h of incubation. aNDF disappearance values were significantly altered by seed type(P= 0.003) and isoflavone treatment (P= 0.005), and ADF disappearance values were significantly different in a seed x isoflavone treatment interaction (P≤ 0.05). A seed x isoflavone treatment interaction was also observed with respect to CP disappearance (P≤ 0.05). Seventeen bacterial taxa were significantly altered by seed x isoflavone treatment interaction groups (P≤ 0.05), six bacterial taxa were increased by isoflavones (P≤ 0.05), and eleven bacterial taxa were altered by seed type (P≤ 0.05). Due to the beneficial effect of isoflavones on tall fescue seed fiber degradation, these compounds may be viable options for mitigating fescue toxicosis. Further research should be conducted to determine physiological implications as well as microbiological changesin vivo.

Negative impacts of endophyte-infected Lolium arundinaceum (Darbyshire) (tall fescue) are responsible for over $2 billion in losses to livestock producers annually. While the influence of endophyte-infected tall fescue has been studied for decades, mitigation methods have not been clearly elucidated. Isoflavones found in Trifolium pratense (red clover) have been the subject of recent research regarding tall fescue toxicosis mitigation. Therefore, the aim of this study was to determine the effect of ergovaline and red clover isoflavones on rumen microbial populations, fiber degradation, and volatile fatty acids (VFA) in an in vitro system. Using a dose of 1.10 mg × L-1, endophyte-infected or endophyte-free tall fescue seed was added to ANKOM fiber bags with or without 2.19 mg of isoflavones in the form of a control, powder, or pulverized tablet, resulting in a 2 × 3 factorial arrangements of treatments. Measurements of pH, VFA, bacterial taxa, as well as the disappearance of neutral detergent fiber (aNDF), acid detergent fiber (ADF), and crude protein (CP) were taken after 48 h of incubation. aNDF disappearance values were significantly altered by seed type (P = 0.003) and isoflavone treatment (P = 0.005), and ADF disappearance values were significantly different in a seed × isoflavone treatment interaction (P ≤ 0.05). A seed × isoflavone treatment interaction was also observed with respect to CP disappearance (P ≤ 0.05). Eighteen bacterial taxa were significantly altered by seed × isoflavone treatment interaction groups (P ≤ 0.05), eight bacterial taxa were increased by isoflavones (P ≤ 0.05), and ten bacterial taxa were altered by seed type (P ≤ 0.05). Due to the beneficial effect of isoflavones on tall fescue seed fiber degradation, these compounds may be viable options for mitigating fescue toxicosis. Further research should be conducted to determine physiological implications as well as microbiological changes in vivo.

N'-Nitrosonornicotine (6) is a potent and organ-specific carcinogen found in tobacco and tobacco smoke in substantial amounts. Nicotine (1) and nornicotine (2) are proposed to be the precursors of 6 in tobacco. Since 1 can be rapidly demethylated to 2 in tobacco, to distinguish between the direct formation of 6 from these potential precursors is difficult. A gas chromatography/thermal energy analyzer method using two columns in series was developed to separate the enantiomers of 6, N'-nitrosoanabasine (7), and N'-nitrosoanatabine (8). Tobacco lines with different combinations of three nicotine demethylases inhibited were grown in the field. Air-cured leaves were analyzed for the enantiomeric composition of four main alkaloids and their corresponding tobacco-specific nitrosamines. The percentage of (R)-6 of total 6 varied from 7% to 69% in mutant lines. The measured 6 had the same enantiomeric composition as 2, rather than 1, even when the level of 2 was reduced to 0.6% of 1 in a triple mutant line. The pattern of the enantiomeric composition of 1, 2, and 6 demonstrated that the direct formation of 6 from 1, if it occurs, is negligible in air-cured tobacco. Since (S)-6 is more highly carcinogenic than its R form, the reduction of (S)-2 should be a priority for the reduction of 6.

Ergot alkaloids produced by a fungal endophyte (Epichloë coenophiala; formerly Neotyphodium coenophialum) that infects tall fescue (Lolium arundinaceum) can induce persistent constriction of the vasculature in ruminants, hindering their capability to thermo-regulate core body temperature. There is evidence that isoflavones produced by legumes can relax the vasculature, which suggests that they could relieve ergot alkaloid-induced vasoconstriction and mitigate the vulnerability to severe heat stress in ruminants that graze tall fescue. To test if isoflavones can relieve alkaloid-induced vasoconstriction, two pen experiments were conducted with rumen-fistulated goats (Capra hircus) to determine with ultrasonograpy if isoflavones can (1) promote vascular compliance by countering alkaloid-induced vasoconstriction and (2) relieve already imposed alkaloid-induced vasoconstriction. Goats were fed ad libitum chopped orchardgrass (Dactylis glomerata)–timothy (Phleum pratense) hay prior to conducting the experiments. Measures of carotid and interosseous luminal areas were obtained pre- (baseline) and post-ruminal infusions in both experiments with goats being fed the hay, and for blood flow rate in the carotid artery in Experiment 2. Responses to infusion treatments were evaluated as proportionate differences from baseline measures. Peak systolic velocity, pulsatility index, and heart rate were measured on the last day on treatment (DOT) in Experiment 1, and on all imaging sessions during Experiment 2. For Experiment 1, rumens were infused with ground toxic fescue seed and isoflavones in Phase A and with only the toxic seed in Phase B. The infusion treatments were switched between phases in Experiment 2, which employed a fescue seed extract having an ergot alkaloid composition equivalent to that of the ground seed used in Experiment 1. During Experiment 1, luminal areas of carotid and interosseous arteries in Phase A did not deviate (P > 0.1) from baselines over 1, 2, 3, and 4 DOT, but the areas of both declined linearly from baselines over 1, 2, 3, and 4 DOT in Phase B. By 6, 7, and 8 DOT in Experiment 2, luminal areas of the arteries and flow rate declined from baselines with infusions with the only seed extract in Phase A, but luminal areas and flow rate increased over 4, 5, and 6 DOT with the additional infusion of isoflavones. Peak systolic velocity and heart rate were not affected by treatment in either experiment, but were highest when infused with only ergot alkaloids in both experiments. Treatment with isoflavones was demonstrated to relax the carotid and interosseous arteries and reduce resistance to blood flow. Results indicate that isoflavones can relax persistent vasoconstriction in goats caused by consumption of ergot alkaloids, and mitigate the adverse effect that ergot alkaloids have on dry matter intake.

Tall fescue pastures cover extensive acreage in the eastern half of the United States and contribute to important ecosystem services, including the provisioning of forage for grazing livestock. Yet little is known concerning how these pastures will respond to climate change. Tall fescue’s ability to persist and provide forage under a warmer and wetter environment, as is predicted for much of this region as a result of climate change, will likely depend on a symbiotic relationship the plant can form with the fungal endophyte, Epichloe coenophiala. While this symbiosis can confer environmental stress tolerance to the plant, the endophyte also produces alkaloids toxic to insects (e.g., lolines) and mammals (ergots; which can cause ‘fescue toxicosis’ in grazing animals). The negative animal health and economic consequences of fescue toxicosis make understanding the response of the tall fescue symbiosis to climate change critical for the region. We experimentally increased temperature (+3oC) and growing season precipitation (+30% of the long-term mean) from 2009 – 2013 in a mixed species pasture, that included a tall fescue population that was 40% endophyte-infected. Warming reduced the relative abundance of tall fescue within the plant community, and additional precipitation did not ameliorate this effect. Warming did not alter the incidence of endophyte infection within the tall fescue population; however, warming significantly increased concentrations of ergot alkaloids (by 30-40%) in fall-harvested endophyte-infected individuals. Warming alone did not affect loline alkaloid concentrations, but when combined with additional precipitation, levels increased in fall-harvested material. Although future warming may reduce the dominance of tall fescue in eastern U.S. pastures and have limited effect on the incidence of endophyte infection, persisting endophyte-infected tall fescue will have higher concentrations of toxic alkaloids which may exacerbate fescue toxicosis.

Effect of LED supplemental illumination on the growth of strawberry plants is presented. Four LED combination lighting systems with different LED colors and power were designed and developed for supplemental illumination of the strawberry plants cultivated in the greenhouse. The LED supplemental illumination time is 4 hours everyday. The growth parameters of the strawberry plants were measured every 7 days. The plant height, leaf number, petiole length, leaf area of the strawberry plants which cultivated with LED supplemental illumination were more superior to those cultivated under the normal condition. However, there was no significant difference in the number of blossoms and fruits. The study results indicated that the supplemental illumination with LED combination lighting systems could promote the vegetative growth of strawberry plants and the promoting effect is better with the LED power increase. LEDs combination of orange/red/blue ratio of 3:2:1 is more superior to the LEDs with red/blue ratio of 5:1. the spectrum of the former is much more similar to the absorption spectrum of the plant photosynthesis.

An intelligent controlling system for LED plant supplemental lighting greenhouse is presented in this paper. The key unit of the system is a remote controlling and management center, which comprises of the sensing subsystem, the data acquisition subsystem, the information processing subsystem and the execution subsystem. The combined lighting with red and blue LED was used to provide supplemental lighting for plants in greenhouse. In order to adjust the environment of greenhouse, the controlling system will obtain real-time parameters feedback of the temperature, the relative humidity and the light intensity, and send commands to the execution subsystem through RS-485 communication lines.

The method to evaluate the grade of the pork based on hyperspectral imaging techniques was studied. Principal component analysis (PCA) was performed on the hyperspectral image data to extract the principal components which were used as the inputs of the evaluation model. By comparing the different discriminating rates in the calibration set and the validation set under different information, the choice of the components can be optimized. Experimental results showed that the classification evaluation model was the optimal when the principal of component (PC) of spectra was 3, while the corresponding discriminating rate was 89.1% in the calibration set and 84.9% in the validation set. It was also good when the PC of images was 9, while the corresponding discriminating rate was 97.2% in the calibration set and 91.1% in the validation set. The evaluation model based on both information of spectra and images was built, in which the corresponding PCs of spectra and images were used as the inputs. This model performed very well in grade classification evaluation, and the discriminating rates of calibration set and validation set were 99.5% and 92.7%, respectively, which were better than the two evaluation models based on single information of spectra or images.

A new apparatus for continuous measuring the falling velocity of wind-dispersal seeds is presented in this paper. The key unit of this apparatus is the photo-detectors installed on the ends of a vertical tube. The photodetector is composed of a LED and a photo-sensor. The LED light goes through a horizontal slit to from a flat light plane, which be received by the photo-sensors on the opposite side. When a plant seed falls down and passes through the flat light plane, a pulse signal will be detected by the photo-sensor. The average falling velocity of the seed is calculated according to the falling time and the distance from the starting point to the testing point. By using several tubes and photo-detectors, the apparatus can continuously measure the velocity of a seed falling down to different height. This apparatus avoids the affect of the static electricity and airflow to the seeds.