748 research outputs found
Protoplast transformation as a potential platform for exploring gene function in Verticillium dahliae
Position of siRNAs along the Vta2 gene of V. dahliae. The position of different siRNAs designed to target this gene is shown in this figure. Sequence underlined with different colors shows different siRNAs. (JPG 7797 kb
Fractional crystallization causes the iron isotope contrast between mid-ocean ridge basalts and abyssal peridotites
The iron isotope contrast between mid-ocean ridge basalts and abyssal peridotites is far greater than can be explained by mantle melting alone. Here we investigate a suite of mid-ocean ridge magma chamber rocks sampled by the Ocean Drilling Project Hole 735B in the Atlantis Bank of the Indian Ocean. We report major and trace element geochemistry from these rocks and measure their iron isotope compositions to investigate the potential role of fractional crystallization during melt evolution. We observe a large range of δ56Fe that defines a significant inverse curvilinear correlation with bulk rock MgO/FeOT. These data confirm that δ56Fe in the melt increases as fractional crystallization proceeds but, contrary to expectation, δ56Fe continues to increase even when oxides begin to crystallize. We conclude that iron isotope fractionation through fractional crystallization during the evolution of mid-ocean ridge basalts from abyssal peridotites reconciles the disparity in isotopic compositions between these two lithologies
Influence of receptor flexibility on intramolecular H-bonding interactions.
Atropisomers of a series of zinc tetraphenyl porphyrins were synthesized and used as supramolecular receptors. Rotation around the porphyrin-meso phenyl bonds is restricted by installing ortho-chlorine substituents on the phenyl groups. The chlorine substituents allowed chromatographic separation of atropisomers, which did not interconvert at room temperature. The porphyrin meso phenyl groups were also equipped with phenol groups, which led to the formation of intramolecular H-bonds when the zinc porphyrins were bound to pyridine ligands equipped with ester or amide side arms. Binding of the pyridine ligands with the conformationally locked chloroporphyrins was compared with the corresponding unsubstituted porphyrins, which are more flexible. The association constants of 150 zinc porphyrin-pyridine complexes were measured in two different solvents, toluene and 1,1,2,2-tetrachloroethane (TCE). These association constants were then used to construct 120 chemical double mutant cycles to quantify the influence of chlorine substitution on the free energy of intramolecular H-bonds formed between the phenol side arms of the porphyrins and the ester or amide side arms of the pyridine ligands. Conformational restriction leads to increases in the stability of some complexes and decreases in the stability of others with variations in the free energy contribution due to intramolecular H-bonding of -5 to +6 kJ mol(-1).We thank the EPSRC, the China Scholarship Council, and the University of Sheffield for funding.This is the final version of the article. It first appeared from RSC via http://dx.doi.org/10.1039/C5OB00805
Bargaining Power Choices with Moral Hazard in a Supply Chain
A supply chain contract is established using a dynamic, Nash bargaining game which determines the optimal bargaining power allocation for the manufacturer, retailer, and society in an environment affected by moral hazard and irreversible investment. The results found that the manufacturer’s choice was to hold all bargaining power; however, due to the remaining information problem, the retailer still had a profit; in contrast, the retailer was only willing to give up bargaining power if the manufacturer’s profit was reserved. The optimal bargaining power allocation was found to be strongly related to the ability to convert and monitor technology, with the bargaining power gradually shifting to the manufacturer as the technology improved. A numerical simulation is given to examine the theoretical results
Contractile Force of Human Extraocular Muscle: A Theoretical Analysis
Aim. The length-contractile force relationships of six human extraocular muscles (EOMs) in primary innervations should be determined during eye movement modeling and surgery of clinical EOMs. This study aims to investigate these relationships. Method. The proposal is based on the assumption that six EOMs have similar constitutive relationships, with the eye suspended in the primary position. The constitutive relationships of EOMs are obtained by optimizing from previous experimental data and the theory of mechanical equilibrium using traditional model. Further, simulate the existing experiment of resistance force, and then compare the simulated results with the existing experimental results. Finally, the mechanical constitutive relationships of EOMs are obtained. Results. The results show that the simulated resistance forces from the other four EOMs except for the horizontal recti well agree with previous experimental results. Conclusion. The mechanical constitutive relationships of six EOMs in primary innervations are obtained, and the rationality of the constitutive relationships is verified. Whereafter, the active stress-strain relationships of the six EOMs in the primary innervations are obtained. The research results can improve the eye movement model to predict the surgical amounts of EOMs before EOM surgery more precisely
Sedentary Behavior Is Independently Related to Fat Mass among Children and Adolescents in South China
We aim to explore the independent associations of sedentary behaviors (SB)
with body mass distribution among Chinese children. Data on the screen-based
sedentary time (television viewing and computer use) and doing homework,
physical activities and dietary intake of 1586 Chinese children (50.3% girls)
aged 7–15 years were obtained through validated questionnaires. Skin-fold
thickness, body height, and weight were measured to calculate percent body fat
(%BF), fat mass index (FMI), and fat-free mass index (FFMI). Parental
characteristics were collected by questionnaires. Among girls, time of SB
(screen time or doing homework) was positively related to %BF, FMI, and FFMI
(p < 0.03) after adjusting for maternal overweight, the average annual income
of family, moderate-to-vigorous physical activity energy expenditure, and
energy intake: Girls in the highest tertile of screen time/homework had
16.7%/23.3% higher relative FMI and 2.9%/2.9% higher relative FFMI than girls
in the lowest tertile. Among boys, screen time was positively associated with
FFMI (p 0.09), while time of
doing homework was positively related to %BF and FMI (p = 0.03). Sedentary
behaviors might be positively and independently related to fat mass among
Chinese children, and were more pronounced in girls
Effect of acupotomy on nitric oxide synthase and beta-endorphin in third lumbar vertebrae transverse process syndrome model rats
AbstractObjectiveTo explore the long-term effects and pain relief mechanism of acupotomy by observing changes in nitric oxide synthase (NOS) and beta-endorphin (β-EP) in the hypothalamus, spinal cord, and peripheral blood of rats with third lumbar vertebrae (L3) transverse process syndrome.MethodsTwenty-eight SD rats were randomly assigned to normal, model, electroacupuncture (EA), and acupotomy group. The last three groups were put through an operation to emulate L3 transverse process syndrome. Fourteen days after the simulation operation, EA and acupotomy treatments were applied to the respective groups. Fifty-six days after the simulation operation, biochemistry tests and enzyme-linked immunosorbent assay were used to measure NOS and β-EP in the hypothalamus, spinal cord, and peripheral blood.ResultsRats with the simulation operation showed significantly higher levels of NOS and β-EP in the hypothalamus, spinal cord, and peripheral blood than those in the normal group. The EA and acupotomy groups had significantly lower levels of NOS and β-EP than those in the model group. There was no statistical difference between the EA and acupotomy groups.ConclusionEA and acupotomy treatments significantly lowered NOS and β-EP levels in the hypothalamus, spinal cord, and peripheral blood and alleviated L3 transverse process syndrome
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