88 research outputs found
A sensitivity analysis of the prediction of the nitrogen fertilizer requirement of cauliflower crops using the HRI WELL_N computer model
HRI WELL_N is an easy to use computer model, which has been used by farmers and growers since 1994 to predict crop nitrogen (N) requirements for a wide range of agricultural and horticultural crops.
A sensitivity analysis was carried out to investigate the model predictions of the N fertilizer requirement of cauliflower crops, and, at that rate, the yield achieved, yield response to the fertilizer applied, N uptake, NO3-N leaching below 30 and 90 cm and mineral N at harvest. The sensitivity to four input factors – soil mineral N before planting, mineralization rate of soil organic matter, expected yield and duration of growth – was assessed. Values of these were chosen to cover ranges between 40% and 160% of values typical for field crops of cauliflowers grown in East Anglia. The assessments were made for three soils – sand, sandy loam and silt – and three rainfall scenarios – an average year and years with 144% or 56% of average rainfall during the growing season. The sensitivity of each output variable to each of the input factors (and interactions between them) was assessed using a unique ‘sequential' analysis of variance approach developed as part of this research project.
The most significant factors affecting N fertilizer requirement across all soil types/rainfall amounts were soil mineral N before planting and expected yield. N requirement increased with increasing yield expectation, and decreased with increasing amounts of soil mineral N before planting. The responses to soil mineral N were much greater when higher yields were expected. Retention of N in the rooting zone was predicted to be poor on light soils in the wettest conditions suggesting that to maximize N use, plants needed to grow rapidly and have reasonable yield potential.
Assessment of the potential impacts of errors in the values of the input factors indicated that poor estimation of, in particular, yield expectation and soil mineral N before planting could lead to either yield loss or an increased level of potentially leachable soil mineral N at harvest.
The research demonstrates the benefits of using computer simulation models to quantify the main factors for which information is needed in order to provide robust N fertilizer recommendations
Exact Performance of Concatenated Quantum Codes
When a logical qubit is protected using a quantum error-correcting code, the
net effect of coding, decoherence (a physical channel acting on qubits in the
codeword) and recovery can be represented exactly by an effective channel
acting directly on the logical qubit. In this paper we describe a procedure for
deriving the map between physical and effective channels that results from a
given coding and recovery procedure. We show that the map for a concatenation
of codes is given by the composition of the maps for the constituent codes.
This perspective leads to an efficient means for calculating the exact
performance of quantum codes with arbitrary levels of concatenation. We present
explicit results for single-bit Pauli channels. For certain codes under the
symmetric depolarizing channel, we use the coding maps to compute exact
threshold error probabilities for achievability of perfect fidelity in the
infinite concatenation limit.Comment: An expanded presentation of the analytic methods and results from
quant-ph/0111003; 13 pages, 6 figure
Reversing the “risk‐treatment paradox” of bleeding in patients undergoing percutaneous coronary intervention: Risk‐concordant use of bleeding avoidance strategies is associated with reduced bleeding and lower costs
Novel patient-centered approach to facilitate same-day discharge in patients undergoing elective percutaneous coronary intervention
Background
Same‐day discharge (
SDD
) after elective percutaneous coronary intervention is safe, less costly, and preferred by patients, but it is usually performed in low‐risk patients, if at all. To increase the appropriate use of
SDD
in more complex patients, we implemented a “patient‐centered” protocol based on risk of complications at Barnes‐Jewish Hospital.
Methods and Results
Our objectives were as follows: (1) to evaluate time trends in
SDD
; (2) to compare (a) mortality, bleeding, and acute kidney injury, (b) patient satisfaction, and (c) hospital costs by
SDD
versus no SDD (
NSDD
); and (3) to compare
SDD
eligibility by our patient‐centered approach versus Society for Cardiovascular Angiography and Interventions guidelines. Our patient‐centered approach was based on prospectively identifying personalized bleeding, mortality, and acute kidney injury risks, with a personalized safe contrast limit and mitigating those risks. We analyzed Barnes‐Jewish Hospital's National Cardiovascular Data Registry Cath
PCI
Registry data from July 1, 2009 to September 30, 2015 (N=1752).
SDD
increased rapidly from 0% to 77% (
P
<0.001), independent of radial access. Although
SDD
patients were comparable to
NSDD
patients,
SDD
was not associated with adverse outcomes (0% mortality, 0% bleeds, and 0.4% acute kidney injury). Patient satisfaction was high with
SDD
. Propensity score–adjusted costs were 7331 lower/
SDD
patient (
P
<0.001), saving an estimated 1.8 million annually. Only 16 patients (6.95%) met the eligibility for
SDD
by Society for Cardiovascular Angiography and Interventions guidelines, implying our patient‐centered approach markedly increased
SDD
eligibility.
Conclusions
With a patient‐centered approach,
SDD
rapidly increased and was safe in 75% of patients undergoing elective percutaneous coronary intervention, despite patient complexity. Patient satisfaction was high, and hospital costs were lower. Patient‐centered decision making to facilitate
SDD
is an important opportunity to improve the value of percutaneous coronary intervention.
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DETC2008-49886 PIEZOELECTRIC T-BEAM MICROACTUATORS
ABSTRACT This paper introduces a novel T-beam actuator fabricate
Magnetically induced metal-insulator transition in Pb2CaOsO6
We report on the structural, magnetic, and electronic properties of two new
double-perovskites synthesized under high pressure; Pb2CaOsO6 and Pb2ZnOsO6.
Upon cooling below 80 K, Pb2CaOsO6 simultaneously undergoes a metal--insulator
transition and develops antiferromagnetic order. Pb2ZnOsO6, on the other hand,
remains a paramagnetic metal down to 2 K. The key difference between the two
compounds lies in their crystal structure. The Os atoms in Pb2ZnOsO6 are
arranged on an approximately face-centred cubic lattice with strong
antiferromagnetic nearest-neighbor exchange couplings. The geometrical
frustration inherent to this lattice prevents magnetic order from forming down
to the lowest temperatures. In contrast, the unit cell of Pb2CaOsO6 is heavily
distorted up to at least 500 K, including antiferroelectric-like displacements
of the Pb and O atoms despite metallic conductivity above 80 K. This distortion
relieves the magnetic frustration, facilitating magnetic order which in turn
drives the metal--insulator transition. Our results suggest that the phase
transition in Pb2CaOsO6 is spin-driven, and could be a rare example of a Slater
transition.Comment: 14 pages, 9 figures. Accepted as a regular article in Phys. Rev.
Elesclomol restores mitochondrial function in genetic models of copper deficiency
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 115 (2018): 8161-8166, doi:10.1073/pnas.1806296115.Copper is an essential cofactor of cytochrome c oxidase (CcO), the terminal enzyme of the mitochondrial respiratory chain. Inherited loss-of-function mutations in several genes encoding proteins required for copper delivery to CcO result in diminished CcO activity and severe pathologic conditions in affected infants. Copper supplementation restores CcO function in patient cells with mutations in two of these genes, COA6 and SCO2, suggesting a potential therapeutic approach. However, direct copper supplementation has not been therapeutically effective in human patients, underscoring the need to identify highly efficient copper transporting pharmacological agents. By using a candidate-based approach, we identified an investigational anticancer drug, elesclomol (ES), that rescues respiratory defects of COA6-deficient yeast cells by increasing mitochondrial copper content and restoring CcO activity. ES also rescues respiratory defects in other yeast mutants of copper metabolism, suggesting a broader applicability. Low nanomolar concentrations of ES reinstate copper-containing subunits of CcO in a zebrafish model of copper deficiency and in a series of copper-deficient mammalian cells, including those derived from a patient with SCO2 mutations. These findings reveal that ES can restore intracellular copper homeostasis by mimicking the function of missing transporters and chaperones of copper, and may have potential in treating human disorders of copper metabolism.This work was supported by National Institutes of Health Awards R01GM111672 (to V.M.G.), R01 DK110195 (to B.-E.K.), and DK 44464 (to J.D.G.); Welch Foundation Grant A-1810 (to V.M.G.); and Canadian Institutes of Health Research Operating Grant MOP 133562 (to S.C.L.)
Extensional faulting on Tinos island, Aegean sea, Greece: How many detachments?
Zircon and apatite fission track (ZFT and AFT) and (U-Th)/He, 40Ar/39Ar hornblende, and U-Pb zircon ages from the granites of Tinos Island in the Aegean Sea, Greece, suggest, together with published ZFT data, that there are three extensional detachments on Tinos. The Tinos granites crosscut the Tinos detachment. Cooling of the granites was controlled by the Livadi detachment, which occurs structurally above the Tinos detachment. Our U-Pb zircon age is 14.6 ± 0.2 Ma and two 40Ar/39Ar hornblende ages are 14.4 ± 0.4 and 13.7 ± 0.4 Ma. ZFT and AFT ages go from 14.4 ± 1.2 to 12.2 ± 1.0 Ma and 12.8 ± 2.4 to 11.9 ± 2.0 Ma. (U-Th)/He ages are from 10.4 ± 0.2 to 9.9 ± 0.2 Ma (zircon) and 11.9 ± 0.5 to 10.0 ± 0.3 Ma (apatite). All ages decrease northeastward in the direction of hanging wall transport on the Livadi detachment and age-distance relationships yield a slip rate of 2.6 (+3.3 / −1.0) km Ma−1. This rate is smaller than a published slip rate of 6.5 km Ma−1 for the Vari detachment, which is another detachment structurally above the Tinos detachment. Because of the different rates and because published ZFT ages from the footwall of the Vari detachment are ∼10 Ma, we propose that the Vari detachment has to be distinguished from the older Livadi detachment. We discuss various models of how the extensional detachments may have evolved and prefer a scenario in which the Vari detachment cut down into the footwall of the Livadi detachment successively exhuming deeper structural units. The thermochronologic ages demonstrate the importance of quantitative data for constraining localization processes during extensional deformation
The O28 Antigen Gene Clusters of Salmonella enterica
A 10 kb O-antigen gene cluster was sequenced from a Salmonella enterica subsp. enterica Dakar O28 reference strain and from two S. Pomona serogroup O28 isolates. The two S. Pomona O antigen gene clusters showed only moderate identity with the S. Dakar O28 gene cluster, suggesting that the O antigen oligosaccharides may contain one or more sugars conferring the O28 epitope but may otherwise be different. These novel findings are absolutely critical for the correct interpretation of molecular serotyping assays targeting genes within the O antigen gene clusters of these Salmonella serotypes and suggest the possibility that the O antigen gene clusters of other Salmonella serovars may also be heterogenous
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