1,921 research outputs found
Analysis of the Effects of Hypogeal and Epigeal Emergence on Seedling Competition in Legumes
Seedling emergence is either hypogeal or epigeal. In hypogeal emergence the cotyledons remain below the soil surface during seedling development, while in epigeal emergence the cotyledons extend above the soil surface due to elongation of the hypocotyl. Here we examine the effect of seed size, and emergence type, on seedling growth. Six legumes with variation in seed size and either epigeal or hypogeal emergence were grown under dark and light conditions. A competition study was also conducted where a hypogeal and epigeal legume were grown in combination with wheat and ryegrass. Legumes expressing epigeal emergence were cowpea (Vigna unguiculata), mung bean (Vigna radiata) and soybean (Glycine max Merr.), while Austrian winter pea (Pisurn sativum var. arvense (L.) Poir), field pea (Pisum arvense) and lentil (Lens culinaris) expressed hypogeal emergence. In the dark growth study, seed size did not have a direct effect on growth, but there was a correlation with the heavier seeded species having heavier seedlings. Soybean had the largest seedlings under both dark and light conditions. Wheat and ryegrass competition reduced both Austrian winter pea and soybean growth. However, the cool air-temperature during the study may have favored the growth of Austrian winter pea, a cool-season legume. Soybean, a warm-season legume, seedling development may have been limited by the cool-temperature. We could not separate hypogeal or epigeal emergence types as to seedling growth or competitiveness. However, seed size did have a direct effect on seedling size, regardless of emergence \u27 type
Mineral evaluation and Quantitative Trait Loci mapping in a soybean (Glycine max (L.) Merr.) population developed for iron deficiency chlorosis resistance
The identification of the causal gene(s) of disease resistance is paramount in plant breeding. Nutrient analysis in plant tissues can lead to the identification of these gene(s). The objectives of this research were 1) to map quantitative trait loci (QTL) for seed and leaf iron and zinc concentration in the soybean population Anoka x A7, 2) to determine if QTL for iron and zinc accumulation co-localized to the same regions of the genome, 3) to determine if any of newly identified QTL for Fe and/or Zn concentration correlate with QTL previously identified for Fe efficiency, 4) to determine the amount of variation of total phosphorus in a population developed for iron deficiency chlorosis resistance, and 5) to map total phosphorus as a QTL. Iron, zinc, and total phosphorus concentration was determined in 92 F2:4 lines from the Anoka x A7 population grown on non-calcareous soil grown in 2008 and 2009. Dry ashing was the method used to determine iron and zinc, and total phosphorus was determined through an overnight digestion. Nutrients in each set of samples were quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES). The genetic map was integrated with the map of Lin et al. (1997) which consisted of a total of 150 markers and used to locate QTL.
For the iron and zinc study, one significant QTL for iron concentration in soybean seed was mapped on chromosome 20 in the combined data. One marker in this QTL interval, pa_515-1, previously mapped an Fe efficiency QTL. This result presented evidence of a genetic link between Fe efficiency and iron concentration in soybean.
In the total phosphorus study, one significant QTL was mapped on chromosome 12 for phosphorus concentration in the combined data. Candidate genes in this marker interval, S12_0711-S12_1103, are involved in the P storage and homeostasis pathways and mediate the transport of phosphate. The results of this study indicated that total phosphorus uptake and transport could be modified
Research Investments and Market Structure in the Food Processing, Agricultural Input, and Biofuel Industries Worldwide
Meeting growing global demand for food, fiber, and biofuel requires robust investment in agricultural research and development (R&D) from both public and private sectors. This study examines global R&D spending by private industry in seven agricultural input sectors, food manufacturing, and biofuel and describes the changing structure of these industries. In 2007 (the latest year for which comprehensive estimates are available), the private sector spent 19.7 billion on food and agricultural research (56 percent in food manufacturing and 44 percent in agricultural input sectors) and accounted for about half of total public and private spending on food and agricultural R&D in high-income countries. In R&D related to biofuel, annual private-sector investments are estimated to have reached 1.47 billion worldwide by 2009. Incentives to invest in R&D are influenced by market structure and other factors. Agricultural input industries have undergone significant structural change over the past two decades, with industry concentration on the rise. A relatively small number of large, multinational firms with global R&D and marketing networks account for most R&D in each input industry. Rising market concentration has not generally been associated with increased R&D investment as a percentage of industry sales.agricultural biotechnology, agricultural chemicals, agricultural inputs, animal breeding, animal health, animal nutrition, aquaculture, biofuel, concentration ratio, crop breeding, crop protection, farm machinery, fertilizers, Herfindahl index, globalization, market share, market structure, research intensity, seed improvement, Productivity Analysis,
Home Tobacco Smoke Exposure and Neighborhood Support and Safety among U.S. School-Aged Children
Children who are socioeconomically disadvantaged face a myriad of environmental hardships in the neighborhoods in which they live. This study examined the associations between home tobacco smoke exposure (TSE) and neighborhood support, neighborhood safety, and school safety among U.S. school-aged children. Children ages 6-11 years were included in this secondary analysis of 2018-2019 National Survey of Children’s Health data (N = 17,300). Children’s home TSE status was categorized into three levels: (1) no TSE: Child did not live with a smoker; (2) Outside TSE only: Child lived with a smoker who did not smoke inside the home; and (3) Inside TSE: Child lived with a smoker who smoked inside the home. Parent-reported measures of perceived neighborhood support, and neighborhood and school safety were examined; covariates included the child’s age, sex, and race/ethnicity; the parent’s education; the family’s household structure, and federal poverty level. Weighted logistic and ordinal regression models were built adjusting for the covariates. In total, 13.2% of children had outside TSE and 1.7% of children had inside TSE. Multivariable logistic regression model results indicated that children with outside TSE were at decreased odds (AOR = 0.79, 95%CI = 0.65-0.96) of living in a supportive neighborhood compared to children with no TSE. Ordinal regression model results indicated that children with outside TSE (AOR = 0.77, 95%CI = 0.61-0.97) and children with inside TSE were at decreased odds (AOR = 0.62, 95%CI = 0.39-0.99) of going to a school that was perceived as safe. Community-level programs, policies, and funding are needed to improve neighborhood characteristics among children with TSE to improve their future health outcomes
Vibrational relaxation of highly excited toluene
The collisional loss of vibrational energy from gas‐phase toluene, pumped by a pulsed KrF laser operating at 248 nm, has been observed by monitoring the time‐resolved infrared fluorescence from the C–H stretch modes near 3.3 μm. The fragmentation quantum yield of toluene pumped at 248 nm was determined experimentally to be ∼6%. Energy‐transfer data were obtained for 20 collider gases, including unexcited toluene, and analyzed by an improved inversion technique that converts the fluorescence intensity to the bulk average energy, from which is extracted 〈〈ΔE〉〉, the bulk average amount of energy transferred per collision. Comparisons are presented of these results with similar studies of benzene and azulene, and with the time‐resolved ultraviolet absorption study of toluene carried out by Hippler et al. [J. Chem. Phys. 78, 6709 (1983)]. The present results show 〈〈ΔE〉〉 to be nearly directly proportional to the vibrational energy of the excited toluene from 5000 to 25 000 cm−1. For many of the colliders at higher energies, the energy dependence of 〈〈ΔE〉〉 is somewhat reduced. A simple method is described for obtaining good estimates of 〈ΔE〉d (the energy transferred per collision in deactivating collisions) by carrying out an appropriate least‐squares analysis of the 〈〈ΔE〉〉 data. The values of 〈ΔE〉d are then used in master‐equation calculations to investigate possible contributions from ‘‘supercollisions’’ (in which surprisingly large amounts of energy are transferred) in the deactivation of toluene.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70529/2/JCPSA6-95-1-176-1.pd
Towards a viable grand unified model with and GeV
We present a model based on the gauge group
SU(2)SU(2)SU(4) with gauge couplings that are found to
be unified at a scale near the string unification scale. The model breaks
to the minimal supersymmetric standard model at a scale GeV,
which is instrumental in producing a neutrino in a mass range that can serve as
hot dark matter and this scale can also solve the strong CP problem via
Peccei-Quinn (PQ) mechanism with an invisible harmless invisible axion. We show
how this model can accommodate low and high values of and ``exotic"
representations that often occur in string derived models. We show that this
model has lepton flavor violation which can lead to processes which are one or
two orders of magnitude below the current experimental limits.Comment: 16 pages(Latex), 1 PS Figures (uuencoded, epsf.tex), Typo in the
archive title (not in the paper), no change in pape
Assessing the conservation value of waterbodies: the example of the Loire floodplain (France)
In recent decades, two of the main management tools used to stem biodiversity erosion have been biodiversity monitoring and the conservation of natural areas. However, socio-economic pressure means that it is not usually possible to preserve the entire landscape, and so the rational prioritisation of sites has become a crucial issue. In this context, and because floodplains are one of the most threatened ecosystems, we propose a statistical strategy for evaluating conservation value, and used it to prioritise 46 waterbodies in the Loire floodplain (France). We began by determining a synthetic conservation index of fish communities (Q) for each waterbody. This synthetic index includes a conservation status index, an origin index, a rarity index and a richness index. We divided the waterbodies into 6 clusters with distinct structures of the basic indices. One of these clusters, with high Q median value, indicated that 4 waterbodies are important for fish biodiversity conservation. Conversely, two clusters with low Q median values included 11 waterbodies where restoration is called for. The results picked out high connectivity levels and low abundance of aquatic vegetation as the two main environmental characteristics of waterbodies with high conservation value. In addition, assessing the biodiversity and conservation value of
territories using our multi-index approach plus an a posteriori hierarchical classification methodology reveals two major interests: (i) a possible geographical extension and (ii) a multi-taxa adaptation
BioID-based proteomic analysis of the Bid interactome identifies novel proteins involved in cell-cycle-dependent apoptotic priming
From Springer Nature via Jisc Publications RouterHistory: received 2020-05-13, rev-recd 2020-09-24, accepted 2020-09-28, collection 2020-10, registration 2020-10-07, online 2020-10-16, pub-electronic 2020-10-16Publication status: PublishedFunder: John and Janet HartleyAbstract: Apoptotic priming controls the commitment of cells to apoptosis by determining how close they lie to mitochondrial permeabilisation. Variations in priming are important for how both healthy and cancer cells respond to chemotherapeutic agents, but how it is dynamically coordinated by Bcl-2 proteins remains unclear. The Bcl-2 family protein Bid is phosphorylated when cells enter mitosis, increasing apoptotic priming and sensitivity to antimitotic drugs. Here, we report an unbiased proximity biotinylation (BioID) screen to identify regulators of apoptotic priming in mitosis, using Bid as bait. The screen primarily identified proteins outside of the canonical Bid interactome. Specifically, we found that voltage-dependent anion-selective channel protein 2 (VDAC2) was required for Bid phosphorylation-dependent changes in apoptotic priming during mitosis. These results highlight the importance of the wider Bcl-2 family interactome in regulating the temporal control of apoptotic priming
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