5,838 research outputs found

    Calcium regulation of carbohydrate modification in sorghum

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    Two improved Nigeria sorghum cultivars (KSV 8 and ICSV 400) were used to evaluate the effects of steep water Ca2+ treatment on carbohydrate modification in sorghum. The response of all the carbohydrate mobilization indicators evaluated [- and - amylases, diastatic activity (DP), extract andcold water soluble carbohydrates (CWS-carbohydrates)], to steep water Ca2+ treatment was highly significantly (p 0.001) cultivar and steep water Ca2+ treatment dependent. In contrast to KSV 8, Ca2+ treatment generally caused significant repression of -amylase development in ICSV 400. Development of -amylolytic activity in KSV 8 was however, significantly repressed by Ca2+ treatment. Interestingly, - amylase activity constituting well over 80% of total diastatic activity was attained in ICSV 400 grainssubjected to 100 ppm Ca2+ treatment. Hot water extract (HWE) showed statistically insignificant (p 0.1) linear variation with Ca2+ treatment. Although Ca2+ treatment significantly (p .001) repressed  CWS carbohydrates in both cultivars, significantly higher CWS-carbohydrates and HWE were released in ICSV 400 for each DP unit than the corresponding DP in KSV 8 malts would permit. Thus, suggesting important roles for factors other than DP, possibly proteolysis, in determining HWE and  CWS carbohydrates. The benefits of reduced kernel growth and malting loss were neutralized by the general repression of carbohydrate modification indices for both cultivars

    The effects of calcium regulation of endosperm reserve protein mobilization of the Nigeria sorghum cultivars, ICSV 400 and KSV 8 during malting

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    The effects of steep liquor calcium ion on sorghum endosperm reserve protein mobilization were evaluated using two improved Nigeria sorghum cultivars (ICSV 400 and KSV 8). The key protein modification factors evaluated were free amino nitrogen (FAN), total non protein nitrogen (TNPN) and soluble protein of cold water extract (CWS-P). Ca2+ treatment highly significantly (P < 0.001) repressed FAN development in both sorghum cultivars ICSV 400 and KSV 8. TNPN accumulation significantly enhanced in ICSV 400 by Ca2+ treatment in contrast to KSV8 malts which showed 23 to 69% repression. Similarly, Ca2+ treatment was effective in stimulating peptide accumulation in ICSV 400 at all levels of treatment indicating that the enhancement of TNPN accumulation in this cultivar was derived mainly from the stimulation of peptide accumulation. KSV 8 in contrast showed highly significant repression of peptide accumulation. Protein solubilisation, soluble protein accumulation and cold water soluble protein modification in both cultivars were all highly significantly repressed by Ca2+ treatment; although, ICSV 400 appeared to be better modified. Carboxypeptidase development was stimulated significantly by Ca2+ treatment in both cultivars. Existence of multiple high points in  carboxypeptidase activity suggests heterogeneity of this enzyme in sorghum while Ca2+ treatment caused reduced proteinase development in ICSV 400, the enzyme activity was enhance in KSV 8 albeit marginally.Key words: Sorghum malt, steep water Ca2+ treatment, modification, free amino nitrogen, total non protein nitrogen, carboxypeptidase

    Marked long-term decline in ambient CO mixing ratio in SE England, 1997–2014:Evidence of policy success in improving air quality

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    Atmospheric CO at Egham in SE England has shown a marked and progressive decline since 1997, following adoption of strict controls on emissions. The Egham site is uniquely positioned to allow both assessment and comparison of ‘clean Atlantic background’ air and CO-enriched air downwind from the London conurbation. The decline is strongest (approximately 50ppb per year) in the 1997–2003 period but continues post 2003. A ‘local CO increment’ can be identified as the residual after subtraction of contemporary background Atlantic CO mixing ratios from measured values at Egham. This increment, which is primarily from regional sources (during anticyclonic or northerly winds) or from the European continent (with easterly air mass origins), has significant seasonality, but overall has declined steadily since 1997. On many days of the year CO measured at Egham is now not far above Atlantic background levels measured at Mace Head (Ireland). The results are consistent with MOPITT satellite observations and ‘bottom-up’ inventory results. Comparison with urban and regional background CO mixing ratios in Hong Kong demonstrates the importance of regional, as opposed to local reduction of CO emission. The Egham record implies that controls on emissions subsequent to legislation have been extremely successful in the UK

    Pancreatic cyst fluid harbors a unique microbiome

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    __Background:__ It is clear that specific intestinal bacteria are involved in the development of different premalignant conditions along the gastrointestinal tract. An analysis of the microbial constituents in the context of pancreatic cystic lesions has, however, as yet not been performed. This consideration prompted us to explore whether endoscopically obtained pancreatic cyst fluids (PCF) contain bacterial DNA and to determine the genera of bacteria present in such material. __Methods:__ Total DNA was isolated from 69 PCF samples. Bacterial 16S rRNA gene-specific PCR was performed followed by Sanger sequencing and de novo deep sequencing for the V3-V4 variable region of 16S rRNA gene. __Results:__ We observed that 98.2% of the samples were positive in conventional PCR, and that 100% of selected PCF samples (n = 33) were positive for bacterial microbiota as determined by next generation sequencing (NGS). Comprehensive NGS data analysis of PCF showed the presence of 408 genera of bacteria, of which 17 bacterial genera were uniquely abundant to PCF, when compared to the Human Microbiome Project (HMP) database and 15 bacterial microbiota were uniquely abundant in HMP only. Bacteroides spp., Escherichia/Shigella spp., and Acidaminococcus spp. which were predominant in PCF, while also a substantial Staphylococcus spp. and Fusobacterium spp. component was detected. __Conclusion:__ These results reveal and characterize an apparently specific bacterial ecosystem in pancreatic cyst fluid samples and may reflect the local microbiota in the pancreas. Some taxa with potential deleterious functions are present in the bacterial abundance profiles, suggesting that the unique microbiome in this specific niche may contribute to neoplastic processes in the pancreas. Further studies are needed to explore the intricate relationship between pathophysiological status in the host pancreas and its microbiota

    LHCD and ICRF heating experiments in H-mode plasmas on EAST

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    An ICRF system with power up to 6.0 MW and a LHCD system up to 4MW have been applied for heating and current drive experiments on EAST. Intensive lithium wall coating was intensively used to reduce particle recycling and Hydrogen concentration in Deuterium plasma, which is needed for effective ICRF and LHCD power absorption in high density plasmas. Significant progress has been made with ICRF heating and LHW current drive for realizing the H-mode plasma operation in EAST. In 2010, H-mode was generated and sustained by LHCD alone, where lithium coating and gas puffing launcher mouth were applied to improve the LHCD power coupling and penetration into the core plasmas at high density of H-modes. During the last two experimental campaigns, ICRF Heating experiments were carried out at the fixed frequency of 27MHz, achieving effective ions and electrons heating with the H Minority Heating (H-MH) mode, where electrons are predominantly heated by collisions with high energy minority ions. The H-MH mode gave the best plasma performance, and realized H-mode alone in 2012. Combination of ICRF and LHW power injection generated the H-mode plasmas with various ELMy characteristics. The first successful application of the ICRF Heating in the D (He3) plasma was also achieved. The progress on ICRF heating, LHCD experiments and their application in achieving H-mode operation from last two years will be discussed in this report

    Closing the sea surface mixed layer temperature budget from in situ observations alone: Operation Advection during BoBBLE

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    Sea surface temperature (SST) is a fundamental driver of tropical weather systems such as monsoon rainfall and tropical cyclones. However, understanding of the factors that control SST variability is lacking, especially during the monsoons when in situ observations are sparse. Here we use a ground-breaking observational approach to determine the controls on the SST variability in the southern Bay of Bengal. We achieve this through the first full closure of the ocean mixed layer energy budget derived entirely from in situ observations during the Bay of Bengal Boundary Layer Experiment (BoBBLE). Locally measured horizontal advection and entrainment contribute more significantly than expected to SST evolution and thus oceanic variability during the observation period. These processes are poorly resolved by state-of-the-art climate models, which may contribute to poor representation of monsoon rainfall variability. The novel techniques presented here provide a blueprint for future observational experiments to quantify the mixed layer heat budget on longer time scales and to evaluate these processes in models

    Terahertz frequency quantum cascade lasers for use as waveguide-integrated local oscillators

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    Since their first demonstration in 2002, the performance of terahertz frequency quantum cascade lasers has developed extremely rapidly. We consider the potential use of terahertz frequency quantum cascade lasers as local oscillators in satellite-borne instrumentation for future Earth observation and planetary science missions. A specific focus will be on the development of compact, waveguide-integrated, heterodyne detection systems for the supra-terahertz range

    Feedhorn-integrated THz QCL local oscillators for the LOCUS atmospheric sounder

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    The LOCUS atmospheric sounder is a satellite-borne THz radiometer concept, for studying molecular species in the mesosphere and lower thermosphere. We report waveguide-integrated THz quantum-cascade lasers for use as 3.5 THz local oscillators. A waveguide-integration scheme, using an integrated diagonal feedhorn significantly improves power outcoupling. 1.3 mW THz emission is demonstrated in a space-qualified Stirling cryocooler at 57 K, with ∼15° beam divergence

    A lipidomic approach to identify cold-induced changes in Arabidopsis membrane lipid composition

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    Lipidomic analysis using electrospray ionization triple quadrupole mass spectrometry can be employed to monitor lipid changes that occur during cold and freezing stress of plants. Here we describe the analysis of Arabidopsis thaliana polar glycerolipids with normal and oxidized acyl chains, sampled during cold and freezing treatments. Mass spectral data are processed using the online capabilities of LipidomeDB Data Calculation Environment
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