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Precision placement of fertiliser for optimising the early nutrition of vegetable crops : a review of the implications for the yield and quality of crops, and their nutrient use efficiency
The research outlined in this paper highlights the importance of the early nutrition of vegetable crops, and its long-term effects on their subsequent growth and development. Results are also presented to demonstrate how the nutrient supply during the establishment stages of young seedlings and transplants can be enhanced by targeting fertiliser to a zone close to their developing roots. Three different precision fertiliser placement techniques are compared for this purpose: starter, band or side-injected fertiliser. The use of each of these methods consistently produced the same (or greater) yields at lower application rates than those from conventional broadcast applications, increasing the apparent recovery of N, P and K, and the overall efficiency of nutrient use, while reducing the levels of residual nutrients in the soil. Starter fertilisers also advanced the maturity of some crops, and enhanced produce quality by increasing the proportions of the larger and/or more desirable marketable grades. The benefits of the different placement techniques are illustrated with selected examples from research at Warwick HRI using different vegetable crops, including lettuce, onion and carrot
Atomic spectrometry update. Clinical and biological materials, foods and beverages
This review discusses developments in elemental mass spectrometry, atomic absorption, emission and fluorescence, XRF and LIBS, as applied to the analysis of specimens of clinical interest, foods and beverages. Sample preparation procedures and quality assurance are also included.</p
Breeding for improved nitrogen use efficiency in oilseed rape
Oilseed rape has a high requirement for nitrogen (N) fertiliser relative to its seed yield. This paper uses published and unpublished work to explore the extent to which the N use efficiency (seed yield Ă· N supply) of oilseed rape could be improved without reducing seed yield. It was estimated that if the concentration of N in the stem and pod wall at crop maturity could be reduced from 1.0 to 0.6%, the root length density increased to 1 cm/cm3 to 100 cm soil depth and the post flowering N uptake increased by 20 kg N/ha then the fertiliser requirement could be reduced from 191 to 142 kg N/ha and the N use efficiency could be increased from 15.2 to 22.4 kg of seed dry matter per kg N. Genetic variation was found for all of the traits that were estimated to be important for N use efficiency. This indicates that there is significant scope for plant breeders to reduce N use efficiency in oilseed rape
The Extraordinarily Rapid Expansion of the X-ray Remnant of Kepler's Supernova (SN1604)
Four individual high resolution X-ray images from ROSAT and the Einstein
Observatory have been used to measure the expansion rate of the remnant of
Kepler's supernova (SN 1604). Highly significant measurements of the expansion
have been made for time baselines varying from 5.5 yrs to 17.5 yrs. All
measurements are consistent with a current expansion rate averaged over the
entire remnant of 0.239 (+/-0.015) (+0.017,-0.010) % per yr, which, when
combined with the known age of the remnant, determines the expansion parameter
m, defined as , to be 0.93 (+/-0.06) (+0.07,-0.04). The error
bars on these results include both statistical (first set of errors) and
systematic (second set) uncertainty. According to this result the X-ray remnant
is expanding at a rate that is remarkably close to free expansion and nearly
twice as fast as the mean expansion rate of the radio remnant. The expansion
rates as a function of radius and azimuthal angle are also presented based on
two ROSAT images that were registered to an accuracy better than 0.5
arcseconds. Significant radial and azimuthal variations that appear to arise
from the motion of individual X-ray knots are seen. The high expansion rate of
the X-ray remnant appears to be inconsistent with currently accepted dynamical
models for the evolution of Kepler's SNR.Comment: 14 pages, including 7 postscript figs, LaTeX, emulateapj. Accepted by
Ap
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Optimising the analysis of transcript data using high density oligonucleotide arrays and genomic DNA-based probe selection
Background: Affymetrix GeneChip arrays are widely used for transcriptomic studies in a diverse range of species. Each gene is represented on a GeneChip array by a probe-set, consisting of up to 16 probe-pairs. Signal intensities across probe-pairs within a probe-set vary in part due to different physical hybridisation characteristics of individual probes with their target labelled transcripts. We
have previously developed a technique to study the transcriptomes of heterologous species based
on hybridising genomic DNA (gDNA) to a GeneChip array designed for a different species, and subsequently using only those probes with good homology.
Results: Here we have investigated the effects of hybridising homologous species gDNA to study the transcriptomes of species for which the arrays have been designed. Genomic DNA from Arabidopsis thaliana and rice (Oryza sativa) were hybridised to the Affymetrix Arabidopsis ATH1 and Rice Genome GeneChip arrays respectively. Probe selection based on gDNA hybridisation
intensity increased the number of genes identified as significantly differentially expressed in two
published studies of Arabidopsis development, and optimised the analysis of technical replicates obtained from pooled samples of RNA from rice.
Conclusion: This mixed physical and bioinformatics approach can be used to optimise estimates of gene expression when using GeneChip arrays
Capital Budgeting for Small Businesses: An Appropriate Modification of Net Present Value
This paper sets forth a capital budgeting technique that is both theoretically correct and sensitive to the special financing needs of the small business. This technique involves evaluating cash flows and determining if they are sufficient to meet the loan payment schedule. A sufficient amount of cash flow must remain after debt obligations are met to compensate the equity investment. Net operating cash flows are discounted at the cost of equity while the tax shield from interest and depreciation is discounted at the cost of debt
Stereocontrolled Synthesis of AminoâSubstituted Carbocycles by PdâCatalyzed Alkene Carboamination Reactions
Aminoâsubstituted alkylidenecyclopentanes were synthesized through a stereoselective intermolecular Pdâcatalyzed alkene carboamination reaction between alkenyl triflates bearing a pendant alkene and exogenous amine nucleophiles. The reactions are effective with a range of different substrate combinations, and proceed with generally high diastereoselectivity. Use of (S)âtBuPhox as the ligand in reactions of achiral substrates provides enantioenriched products with up to 98.5:1.5â
e.r.Adding amines: The palladiumâcatalyzed coupling of amines with enol triflates derived from 2âallylcycloalkanones provides substituted alkylidenecyclopentylamine derivatives in good yield with high levels of stereoselectivity. Achiral substrates are transformed with up to 98.5:1.5â
e.r.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136662/1/chem201700466_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136662/2/chem201700466.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136662/3/chem201700466-sup-0001-misc_information.pd
A Proposed Capital Budgeting Technique For Liquidity Constrained Small Businesses
Although the ad vantages of capital budgeting models using discounted cash flaws are well known, small businesses continue to rely on non-discounted techniques in making capital budgeting decisions. This paper analyzes the financial environment in which small businesses operate that makes traditional capital budgeting models inappropriate. A capital budgeting technique is developed that is sensitive to the needs of small businesses and also meets the three-fold criteria for capital budgeting methods.
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