571 research outputs found

    Plant canopy shape and the influences on UV exposures to the canopy

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    The solar spectra at selected sites over hemispherical, conical and pinnacle plant canopy models has been evaluated with a dosimetric technique. The irradiance at the sites varies by up to a factor of 0.31 compared to the irradiance on a horizontal plane. The biologically effective (UVBE) exposures evaluated with the dosimetric technique at sites over the plant canopy are up to 19% of that on a horizontal plane. Compared to a spectroradiometer, the technique provides a more practicable method of measuring the UVBE exposures at multiple sites over a plant canopy. Usage of a dosimeter at one site to provide the exposures at that site for different sun angles introduces an error of more than 50%. Knowledge of the spectra allowed the UV and UVBE exposures to be calculated at each site along with the exposures to the entire canopies. These were dependent on the sun angle and the canopy shape. For plant damage, the UVBE was a maximum of about 1.4 mJ cm-2/min. Compared to the hemispherical canopy, the UVBE exposure for generalised plant damage was 45% less for the pinnacle canopy and 23% less for the conical canopy. The canopy exposures could not be determined from measurements of the ambient exposure

    Local ras and ros in the hypertrophic differentiation of chondrocytes

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    Newsletter of the Boston University School of Medicine, Student American Medical Association (SAMA

    Sum rules for X-ray magnetic circular dichroism spectra in strongly correlated ferromagnets

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    It is proven that the sum rules for X-ray magnetic dichroism (XMCD) spectra that are used to separate spin and orbital contributions to the magnetic moment are formally correct for an arbitrary strength of electron-electron interactions. However, their practical application for strongly correlated systems can become complicated due to the spectral density weight spreading over a broad energy interval. Relevance of incoherent spectral density for the XMCD sum rules is illustrated by a simple model of a ferromagnet with orbital degrees of freedom.Comment: 4 pages, final versio

    Changes of Serum Calcium Concentration, Frequency of Ruminal Contraction and Feed Intake Soon after Parturition of Dairy Cows Fed Difructose Anhydride III

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    Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis (R2 = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition

    The Role of Flavonol Glycosides and Carotenoids in Protecting Soybean from Ultraviolet-B Damage

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    Soft x-ray magnetic circular dichroism study of Ca_1-xSr_xRuO_3 across the ferromagnetic quantum phase transition

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    Ca_1-xSr_xRuO_3, which is ferromagnetic for Sr concentration x > 0.3, has been studied by x-ray magnetic circular dichroism (XMCD) in Ru 3p and O 1s core-level x-ray absorption. XMCD signals appear at x ~ 0.3 and monotonically increases with x in the ferromagnetic phase. While the monotonic increase of the XMCD signals with x is of a typical Stoner-type, the absence of appreciable change in the spectral line shapes of both the Ru 3p and O 1s XMCD spectra indicate that the itinerant-electron ferromagnetism in Ca_1-xSr_xRuO_3 is influenced by strong electron correlation.Comment: 5 pages, 4 figures, accepted in Phys. Rev. B 1 page, correct the 4th affiliation 5 page, modifiy 9th referenc

    Light-Promoted Hydrogenation of Carbon DioxideÂżAn Overview

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    [EN] Hydrogenation of carbon dioxide is considered as a viable strategy to generate fuels while closing the carbon cycle (heavily disrupted by the abuse in the exploitation of fossil resources) and reducing greenhouse gas emissions. The process can be performed by heat-powered catalytic processes, albeit conversion and selectivity tend to be reduced at increasing temperatures owing to thermodynamic constraints. Recent investigations, as summarised in this overview, have proven that light activation is a distinct possibility for the promotion of CO2 hydrogenation to fuels. This effect is particularly beneficial in methanation processes, which can be enhanced under simulated solar irradiation using materials based on metallic nanoparticles as catalysts. The use of nickel, ruthenium and rhodium has led to substantial efficiencies. Light-promoted processes entail performances on a par with (or even superior to) those of thermally-induced, industrially-relevant, commercial technologies.The author thanks the Spanish Government (Ministerio de EconomĂ­a y Competitividad, MINECO) for financial support via a project for young researchers (CTQ2015-74138-JIN), and the ‘‘Severo Ochoa’’ programme (SEV 2012-0267). The European Union is also acknowledged for the SynCatMatch project (ERCAdG-2014-671093)Puga Vaca, A. (2016). Light-Promoted Hydrogenation of Carbon DioxideÂżAn Overview. Topics in Catalysis. 59(15-16):1268-1278. https://doi.org/10.1007/s11244-016-0658-zS126812785915-16Centi G, Perathoner S (2009) Opportunities and prospects in the chemical recycling of carbon dioxide to fuels. Catal Today 148:191–205Aresta M, Dibenedetto A, Angelini A (2014) Catalysis for the valorization of exhaust carbon: from CO2 to chemicals, materials, and fuels. technological use of CO2. 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    An evaluation tool for FKBP12-dependent and -independent mTOR inhibitors using a combination of FKBP-mTOR fusion protein, DSC and NMR

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    Mammalian target of rapamycin (mTOR), a large multidomain protein kinase, regulates cell growth and metabolism in response to environmental signals. The FKBP rapamycin-binding (FRB) domain of mTOR is a validated therapeutic target for the development of immunosuppressant and anticancer drugs but is labile and insoluble. Here we designed a fusion protein between FKBP12 and the FRB domain of mTOR. The fusion protein was successfully expressed in Escherichia coli as a soluble form, and was purified by a simple two-step chromatographic procedure. The fusion protein exhibited increased solubility and stability compared with the isolated FRB domain, and facilitated the analysis of rapamycin and FK506 binding using differential scanning calorimetry (DSC) and solution nuclear magnetic resonance (NMR). DSC enabled the rapid observation of protein–drug interactions at the domain level, while NMR gave insights into the protein–drug interactions at the residue level. The use of the FKBP12–FRB fusion protein combined with DSC and NMR provides a useful tool for the efficient screening of FKBP12-dependent as well as -independent inhibitors of the mTOR FRB domain

    Differences in serum IL-6 response after 1°C rise in core body temperature in individuals with spinal cord injury and cervical spinal cord injury during local heat stress

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    Objectives: Passive rise in core body temperature achieved by head-out hot water immersion (HHWI) results in acute increases in serum interleukin (IL)-6 but no change in plasma adrenaline in patients with cervical spinal cord injury (CSCI). The purpose of the present study was to determine the mechanism of heat stress-induced increase in serum IL-6. Setting: A cross-sectional study. Methods: The study subjects were 9 with CSCI, 10 with thoracic and lumbar spinal cord injury (TLSCI) and 8 able-bodied (AB) subjects. Time since injury was 16.4±4.1 years in TLSCI and 16.1±3.4 years in CSCI. Subjects were subjected to lower-body heat stress (LBH) by wearing a hot water-perfused suit until 1°C increase in core temperature. The levels of serum IL-6, plasma adrenaline, tumor necrosis factor (TNF)-α, C-reactive protein (CRP), and counts of blood cells were measured at normothermia and after LBH. Results: Serum IL-6 concentrations increased significantly immediately after LBH in all the three groups. ΔIL-6% was lower in CSCI subjects compared with AB subjects. Plasma adrenaline concentrations significantly increased after LBH in AB and TLSCI subjects, but did not change throughout the study in CSCI subjects. Cardiac output and heart rate increased at the end of LBH in all three groups. Conclusion: Under a similar increase in core temperature, ΔIL-6% was lower in the CSCI group compared with the AB group. These findings suggest that the observed rise in IL-6 during hyperthermia is mediated, at least in part, by plasma adrenaline
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