Highest Label Research Articles

Dose responses of silvery-thread moss (Bryum argenteum) to carfentrazone-ethyl

AbstractCarfentrazone-ethyl is one of few herbicides labeled for control of silvery-thread moss (STM) in golf course putting greens, but common use rates are up to three times higher than for broadleaf weeds. Our objective was to determine the efficacy of a single POST application of carfentrazone-ethyl for STM control in greenhouse and field dose response studies. In the greenhouse, carfentrazone-ethyl was applied at 0, 14, 28, 56, 112, and 224 g ai ha–1 to pots containing established STM and creeping bentgrass. Percent gametophyte injury was visually estimated at 14, 28, 49, and 77 d after treatment (DAT). Shoot viability was determined by excising shoots from treated pots and plating them in Petri dishes containing sand. The 28- and 49-DAT ED90 (doses required to cause 90% gametophyte injury) were 26.8 and 54.3 g ha–1, respectively; both of these doses are substantially lower than the label rates for long- and short-term control, respectively. All doses reduced the viability of transplanted shoots at 10 DAT compared to untreated STM; however, regrowth occurred in all Petri dishes by 17 DAT. Field studies were initiated in Manhattan, KS and San Luis Obispo, CA to corroborate greenhouse results. Averaged across locations, carfentrazone-ethyl applied at 56 and 112 g ha–1 caused 76% and 84% STM injury at 14 DAT, but STM injury quickly lessened to 45% and 48% by 28 DAT, respectively. In greenhouse and field studies, STM recovery did not occur until 2 wk after treatment (WAT), which indicates the label-stipulated application interval of 2 wk is too short. Our research suggests that 56 g ha–1 can provide similar burndown control of STM as compared to the highest label rate (112 g ha–1), and turfgrass managers should consider extending the reapplication interval to 3 or 4 wk when moss recovery is observed.

L(3,2,1)-Labeling problems on trapezoid graphs

In graph theory, one of the most important problems is graph labeling. Labeling of graph has a very wide range of applications in [Formula: see text]-ray crystallography, missile guidance, coding theory, signal processing, radar, data base management, astronomy, communication network addressing, circuit design, etc. An extension of [Formula: see text]-labeling ([Formula: see text]-labeling) is [Formula: see text]-labeling ([Formula: see text]-labeling), which is now becoming a well-studied problem due to its application in real life situations. [Formula: see text]-labeling problem and the importance of [Formula: see text]-labeling problem motivates us to consider [Formula: see text]-labeling problem for trapezoid graph. The [Formula: see text]-labeling of a graph [Formula: see text] is an assignment [Formula: see text] from [Formula: see text] to the set [Formula: see text] such that if [Formula: see text] then [Formula: see text], if [Formula: see text] then [Formula: see text] and if [Formula: see text] then [Formula: see text], where [Formula: see text] is the distance between the nodes [Formula: see text] and [Formula: see text]. The [Formula: see text]-labeling number of a graph is denoted by [Formula: see text], it is the highest label used to label the graph [Formula: see text]. In this paper, for trapezoid graph [Formula: see text], it is proved that [Formula: see text], where [Formula: see text] is the degree of the graph [Formula: see text]. This upper bound is the first upper bound for [Formula: see text]-labeling problem on trapezoid graph. Also, to label any trapezoid graph, we have designed an algorithm which maintains the upper bound of the label.

Algoritmos de fluxo máximo em rede aplicado em gerenciamento de fluxo de tráfego aéreo

This paper presents the air traffic Flow Balancing Model (FBM) which uses network maximum flow algorithms to accomplish air traffic flow management in the flight information regions under Brazilian control responsibility . Four maximum flow algorithms were implemented and tested in this work: Edmonds-Karp, Dinic, FIFO Preflow Push and Highest Label Preflow Push. Each algorithm has its particular method to calculate the maximum flow value, that results in different air traffic flow balancing solutions. A case study comparing the results for each algorithm is presented, and the results represent different balancing options that allow the traffic flow managers to choose which one better adapts to the tactical air traffic management scenery under analysis.

Effects of manipulating spray-application parameters on efficacy of the entomopathogenic fungus Beauveria bassiana against western flower thrips, Frankliniella occidentalis, infesting greenhouse impatiens crops*

The effects of various spray application parameters on the efficacy of a clay-based wettable powder formulation of Beauveria bassiana strain GHA conidia against western flower thrips, Frankliniella occidentalis, were evaluated in a series of greenhouse tests. With the aim of optimizing spray application methods to maximize biopesticide efficacy, a series of independent experiments was conducted that varied four spray parameters: application interval, rate, volume, and spray-program timing. Impatiens crops infested with western flower thrips were treated with (1) multiple sprays at the rate of 5×1013 conidia in 935 L aqueous carrier ha−1 applied at 3-, 5-, and 7-day intervals, (2) weekly sprays at rates of 5×1013, 1×1014, and 2.0×1014 conidia in 935 L carrier ha−1, (3) weekly sprays at a rate of 2.0×1014 conidia in volumes of 935, 1870, and 3740 L water ha−1, and (4) multiple sprays at the rate of 2.0×1014 conidia in 3740 L carrier ha−1 applied at 5-day intervals in spray programs initiated before versus after the onset of flowering. Pollen-bearing impatiens flowers were sampled twice weekly to estimate thrips population density, and adult female and second-instar thrips were collected 24 h post application for determination of acquired dose (conidia/insect). Numbers of conidia inoculated onto thrips increased with increasing spray frequency and volume. Dose was unexpectedly not directly correlated with application rate when volume was held constant, suggesting that thrips avoided concentrated spray residues. Statistically significant thrips population reductions relative to controls were achieved only when three to four sprays were applied at the highest label rate in the highest volume at < 7-day intervals. Applications against thrips infesting young, preflowering impatiens crops were not consistently more effective than applications in older crops. The most effective treatment programs reduced pest populations by 30–40% compared to untreated controls; this slowed, but did not stop, the growth of pest populations. Results indicate that use of fungi for thrips management will require integration with other control agents.

Electron Microscopic Investigation of Nitrobenzene Distribution and Effect on Plant Root Tip Cells Ultrastructure

Electron microscopic radioautography demonstrated the penetration of [1-614C]nitrobenzene in maize and soybean root tip cells: radioactive label was detected in cell wall, plasmalemma, nuclei, and cytoplasm. Among cytoplasmic organelles, the highest label was found in mitochondria and plastids. [1-614C]nitrobenzene and/or products of its transformation accumulated in vacuoles. Study of the action of different concentrations of nitrobenzene on cell ultrastructural organization revealed the following picture. Nitrobenzene concentration up to 0.015 mM was harmless for plant cells. Increase of nitrobenzene concentration from 0.015 to 1.5 mM induced several pathological changes, up to the complete destruction of cells. The most damaged organelles were nuclei, mitochondria, and plastids. In the presence of 0.15 mM nitrobenzene the intensification of contacts among cell organelles, especially between endoplasmic reticulum and mitochondria/plastids, was observed. The data indicate some coordination between detoxication activity and energy metabolism during cell reaction to xenobiotic toxicity.

Regioselective Binding of 2,5-Hexanedione to High-Molecular-Weight Rat Neurofilament Proteinsin Vitro

Previous studies have shown selective binding of the neurotoxicant 2,5-hexanedione (2,5-HD) to carboxyl-terminal domains of rat neurofilament (NF) M and H proteinsin vitro.The present study was designed to further localize this binding in native rat NF preparations exposed to [14C]2,5-HD. Purified M and H proteins from 2,5-HD-treated NFs were subjected to cyanogen bromide (CNBr) cleavage, and the resultant peptides were separated by Tris-tricine SDS–PAGE and electroblotted to PVDF membranes. Peptides were identified by direct sequencing of stained bands and the relative radiolabeling of each peptide was determined by comparing band intensities in fluorographed blots. For NF-M, the highest label was found in CNBr 10, a peptide corresponding to residues 678–846 at the extreme carboxyl terminus. This region of the protein includes three highly conserved lysine-containing sequences believed to be critical to its function. For NF-H, the greatest binding was localized in CNBr 7 + 8, representing an incomplete cleavage product of residues 390–810. This peptide contains essentially all of the phosphorylation sites in the carboxyl terminus of NF-H, a domain believed to control NF interactions in the axon. Only minor radiolabeling was observed in other M or H peptides. Extensive dephosphorylation of NFs prior to 2,5-HD exposure had no effect on relative adduct levels in each protein. These results provide additional support for limited and specific binding of 2,5-HD to neurofilaments and indicate that the phosphorylation state of the protein may not substantially influence this binding.

Immunogold Localization and Quantitative Distribution of Two Proteins of the Glycine Decarboxylase Complex in Developing Leaflets of Pea (Pisum sativum L.)

We investigated the distribution of the P- and H-proteins of the glycine decarboxylase complex (EC 2.1.2.10) in developing pea (Pisum sativum L.) leaflets using immunogold techniques. Antibodies to these two proteins did not bind to young, nonphotosynthetic cells. Once the leaflet turned green, the labeling density in the mitochondria of the mesophyll cells increased substantially. Few particles were found in the mitochondria of the paraveinal mesophyll and guard cells. None were found either in the epidermis or in the parenchyma of the vascular tissue. Thus leaflets not yet exposed to light, and nonphotosynthetic cells, do not express these two proteins needed for photorespiration. The process of photorespiration seems to be correlated with the photosynthetic state of the cell and of the organ. It was also found to be positively linked with the integrity of the chloroplast since the highest label density obtained in the mitochondria was found just before the onset of ultrastructural senescence in the chl...

Optimal edge ranking of trees in polynomial time

An edge ranking of a graph is a labeling of the edges using positive integers such that all paths between two edges with the same label contain an intermediate edge with a higher label. An edge ranking isoptimal if the highest label used is as small as possible. The edge-ranking problem has applications in scheduling the manufacture of complex multipart products; it is equivalent to finding the minimum height edge-separator tree. In this paper we give the first polynomial-time algorithm to find anoptimal edge ranking of a tree, placing the problem inP. An interesting feature of the algorithm is an unusual greedy procedure that allows us to narrow an exponential search space down to a polynomial search space containing an optimal solution. AnNC algorithm is presented that finds an optimal edge ranking for trees of constant degree. We also prove that a natural decision problem emerging from our sequential algorithm isP-complete.

Incorporation of 14CO2 in prenylquinones of Chlorella pyrenoidosa

Incorporation and release of (14)C-label in prenylquinones of Chlorella was investigated under steady state conditions. After one hour of (14)CO2-photosynthesis all plastid quinones investigated were labeled. The highest label was found in phylloquinone (18%) while α-tocopherol exhibits the lowest label (0.38%). Among the plastoquinones, plastohydroquinone-9 shows a higher labeling degree (5.1%) and a faster labeling kinetic than plastoquinone-9 (1.6%). After replacement of (14)CO2 against (12)CO2 the total radioactivity in plastohydroquinone-9, α-tocopherol and phylloquinone decreases but in α-tocoquinone and plastoquinone-9 proceeds further. From this labeling kinetic we conclude, that newly synthesized [(14)C]α-tocopherol molecules are converted to [(14)C]α-tocoquinone and [(14)C]plastohydroquinone-9 molecules to [(14)C]plastoquinone-9. From their (14)C-incorporation kinetic half-lives could be calculated for all prenylquinones in the same ranges as previously found for the chlorophylls and carotenoids (Grumbach et al., 1978). Half-lives are shorter in plastohydroquinone-9 (30 min) and plastoquinone-9 (40 min) than in phylloquinone (55 min), α-tocoquinone (50 min) and α-tocopherol (220 min). This means that all prenyl-lipids such as chlorophyll a, α-and β-carotene, plastohydroquinone-9 and plastoquinone-9 which are more directly involved in the process of photosynthesis are subject to a continuous and higher turnover than the xanthophyll and α-tocopherol. From the fast labeling kinetic and short half-lives of α-tocoquinone and especially phylloquinone with a labeling degree of 12% after one hour of (14)CO2 photosynthesis we suppose that perhaps these two prenylquinones are also involved in the photosynthetic activity of chloroplasts.

Half‐Life of sRNA from Primary Roots of Zea mays. A Contribution to the Cytokinin Production

AbstractRoots produce cytokinins, which could be generated from the catabolism of transfer RNA. To prove such a hypothesis, the half‐life of sRNA from primary roots of corn was measured. The shortest half‐life was estimated to be 3 days. Depending on growth, cells at the root tips are “moving” out of the growing region and become differentiated cells. Therefore the highest label at the root tip during the pulse incubation is moving backwards during the chase incubation. Prolonged chase increases the half‐life of sRNA successively, possibly due to decreasing metabolic activities of the originally labeled cells.

TRANSPORT AND METABOLISM OF14C-VALINE IN DATURA STRAMONIUM L

Summary Slight transport of 14C-valine fed to leaves of Datura stramonium L. was found to occur, mainly to fruits but also to roots. The intensity of translocation was affected by the age of the fed leaf, the age of the fruit, the duration of the experiment and the illumination of the plant. Mature leaves of plants kept in darkness do not export 14C-valine in measurable amounts. The inhibition of export in darkness probably occurs in the leaf blade. The fed 14C-valine is metabolized mainly to sucrose, glutamic acid and leucine. Among the amino acids of the proteins, valine carries the highest label, followed by leucine.