319 research outputs found

    Estimation of Carbon Stock in Sungai Merah Protection Forest, Musi Banyuasin Regency of South Sumatra Province

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    Calculation and estimation of carbon stocks in various types of forests and ecosystems in Indonesia has been widely practiced. However, the availability of carbon stock information for some locations in the remaining forest area in South Sumatra Province is still very limited. This study aim to measuring the carbon storage potential and the ratio between the carbon storage value derived from the interpretation of satellite imagery and the storage of carbon stock from the field calculation. The method used is to calculate the estimation of carbon stock through satellite imagery interpretation and field measurement. The largest estimation of carbon stock through satellite image interpretation was found in secondary forest cover type with yield 896,234 ton/c/ha, followed by plantation land type with a yield of 147.104 ton/c/Ha and the smallest is open land cover with value yield of 2.883 tons/c/ha. While carbon stocks through field measurement yield 429,181 ton/c/ha of secondary forest cover type, followed by plantation land type with 41,169 ton/c/ha and 4,283 ton/c/ha for open land type. A comparison of carbon stock estimates of the two approaches used, yielding a reference value of 220%. These comparative values can be used to assist in carrying out initial estimates of carbon stocks in some types of land cover, especially for lowland forest types

    Characterisation of complex polymer mixtures

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    The polymer of intrinsic microporosity PIM-1 was synthesized following various procedures: (i) from fluoro-monomer by the conventional method, (ii) from fluoro-monomer by a high temperature, high shear mixing method and (iii) from chloro-monomer. For a more complete understanding of the structure of the resultant products of a series of polymerizations under different reaction conditions, a multi-detector gel permeation chromatography (GPC) method was established and validated. A procedure for fractionating PIM-1 using chloroform methanol solvent mixtures was established and validated. A combination of multi-detector GPC and matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) masss pectrometry was used for the determination of molar mass distribution and to identify structural differences between fractions and between the products from different synthetic procedures. High molar mass samples tended to have broader molar mass distributions. Both Mark-Houwink plots and hydrodynamic volume plots showed deviation from linearity at Mw= 200000 g mol-1, which was attributed to branching. A low cost route for the preparation of PIM-1 from chloro-monomer was successfully established, though samples prepared by this route had broader polydispersities than those prepared from fluoro-monomers. It was found that stable flexible membranes were formed from samples with Mw > 83000 g mol -1. In addition, a comparison of two analytical methods for extraction and determination of additives in HDPE, LLDPE and PP polymers of interest to Saudi Basic Industries Corporation was performed. A comparison of dissolution with ultrasonic assisted extraction methods for the determination of anti-oxidant additives in polyolefins was performed. Ultrasound assisted extraction methods were found to be superior for HDPE and LLDPE, where conventional dissolution was preferred for PP.EThOS - Electronic Theses Online ServiceSaudi Basic Industries Corporation, Chemical Research DepartmentGBUnited Kingdo

    Acute compartment syndrome of the hand in Henoch-Schonlein Purpura

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    An eight year old boy with Henoch-Schonlein Purpura (HSP) presented with acute compartment syndrome (ACS) of his left hand following arterial cannulation of his radial artery in intensive care unit. Emergency decompression and fasciotomy were performed. The authors report this first case in literature and discuss how HSP can be complicated by ACS and ways to prevent the latter from happening

    Are stentless valves hemodynamically superior to stented valves? Long-term follow-up of a randomized trial comparing Carpentier–Edwards pericardial valve with the Toronto Stentless Porcine Valve

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    ObjectiveThe benefit of stentless valves remains in question. In 1999, a randomized trial comparing stentless and stented valves was unable to demonstrate any hemodynamic or clinical benefits at 1 year after implantation. This study reviews long-term outcomes of patients randomized in the aforementioned trial.MethodsBetween 1996 and 1999, 99 patients undergoing aortic valve replacement were randomized to receive either a stented Carpentier–Edwards pericardial valve (CE) (Edwards Lifesciences, Irvine, Calif) or a Toronto Stentless Porcine Valve (SPV) (St Jude Medical, Minneapolis, Minn). Among these, 38 patients were available for late echocardiographic follow-up (CE, n = 17; SPV, n = 21). Echocardiographic analysis was undertaken both at rest and with dobutamine stress, and functional status (Duke Activity Status Index) was compared at a mean of 9.3 years postoperatively (range, 7.5–11.1 years). Clinical follow-up was 82% complete at a mean of 10.3 years postoperatively (range, 7.5–12.2 years).ResultsPreoperative characteristics were similar between groups. Effective orifice areas increased in both groups over time. Although there were no differences in effective orifice areas at 1 year, at 9 years, effective orifice areas were significantly greater in the SPV group (CE, 1.49 ± 0.59 cm2; SPV, 2.00 ± 0.53 cm2; P = .011). Similarly, mean and peak gradients decreased in both groups over time; however, at 9 years, gradients were lower in the SPV group (mean: CE, 10.8 ± 3.8 mm Hg; SPV, 7.8 ± 4.8 mm Hg; P = .011; peak: CE, 20.4 ± 6.5 mm Hg; SPV, 14.6 ± 7.1 mm Hg; P = .022). Such differences were magnified with dobutamine stress (mean: CE, 22.7 ± 6.1 mm Hg; SPV, 15.3 ± 8.4 mm Hg; P = .008; peak: CE, 48.1 ± 11.8 mm Hg; SPV, 30.8 ± 17.7 mm Hg; P = .001). Ventricular mass regression occurred in both groups; however, no differences were demonstrated between groups either on echocardiographic, magnetic resonance imaging, or biochemical (plasma B-type [brain] natriuretic peptide) assessment (P = .74). Similarly, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups (CE, 27.5 ± 19.1; SPV, 19.9 ± 12.0; P = .69). Freedom from reoperation at 12 years was 92% ± 5% in patients with CEs and 75% ± 5% in patients with SPVs (P = .65). Freedom from valve-related morbidity at 12 years was 82% ± 7% in patients with CEs and 55% ± 7% in patients with SPVs (P = .05). Finally, 12-year actuarial survival was 35% ± 7% in patients with CEs and 52% ± 7% in patients with SPVs (P = .37).ConclusionAlthough offering improved hemodynamic outcomes, the SPV did not afford superior mass regression or improved clinical outcomes up to 12 years after implantation

    Mutation of Arabidopsis copper-containing amine oxidase gene AtCuAOδ alters polyamines, reduces gibberellin content and affects development

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    Polyamines (PAs) are essential metabolites in plants performing multiple functions during growth and development. Copper-containing amine oxidases (CuAOs) catalyse the catabolism of PAs and in Arabidopsis thaliana are encoded by a gene family. Two mutants of one gene family member, AtCuAOδ, showed delayed seed germination, leaf emergence, and flowering time. The height of the primary inflorescence shoot was reduced, and developmental leaf senescence was delayed. Siliques were significantly longer in mutant lines and contained more seeds. The phenotype of AtCuAOδ over-expressors was less affected. Before flowering, there was a significant increase in putrescine in AtCuAOδ mutant leaves compared to wild type (WT), while after flowering both spermidine and spermine concentrations were significantly higher than in WT leaves. The expression of GA (gibberellic acid) biosynthetic genes was repressed and the content of GA1, GA7, GA8, GA9, and GA20 was reduced in the mutants. The inhibitor of copper-containing amine oxidases, aminoguanidine hydrochloride, mimicked the effect of AtCuAOδ mutation on WT seed germination. Delayed germination, reduced shoot height, and delayed flowering in the mutants were rescued by GA3 treatment. These data strongly suggest AtCuAOδ is an important gene regulating PA homeostasis, and that a perturbation of PAs affects plant development through a reduction in GA biosynthesis

    Effects of Goat Manure Fertilization on Grain Nutritional Value in Two Contrasting Quinoa (Chenopodium quinoa Willd.) Varieties Cultivated at High Altitudes

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    In this study, the effects of goat manure fertilization (2, 4, 8, and 12 Tn/ha) on the grain yield, organic compounds, and mineral composition of two quinoa varieties (CICA-17 and Regalona Baer) were evaluated under field conditions in Northwest Argentina. The results indicate that fertilization improved the quinoa grain yield and total protein content. Low manure doses positively affected the fatty acid (FA) profile, and significant changes were determined for the monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acid contents of CICA-17 and on the saturated fatty acid (SFA) contents of R. Baer seeds. The amino acid contents were positively affected in CICA-17 and negatively in R. Baer. Soluble sugars (glucose, fructose, and sucrose), major elements (K, Si, P, Mg, Ca, and Na), minor elements (Fe, Mn, Al, Zn, and Cu), and ultratrace elements (Cr and Li) were detected and discussed in terms of their impact on human nutrition and health. Conclusively, manure addition affected some essential amino acids, the desaturase activity, the n6:n3 and SFA/UFA ratios, the atherogenic index, soluble sugars, and mineral content, and the fatty acid metabolism of each variety was differently affected, especially the C16 and C18 desaturase activity, which responded differently to various manure doses. Manure addition is a promising alternative to improve the nutritional quality and functionality of quinoa grains, but the response is not linear

    Sub-micron moulding topological mass transport regimes in angled vortex fluidic flow

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    Shear stress in dynamic thin films, as in vortex fluidics, can be harnessed for generating non-equilibrium conditions, but the nature of the fluid flow is not understood. A rapidly rotating inclined tube in the vortex fluidic device (VFD) imparts shear stress (mechanical energy) into a thin film of liquid, depending on the physical characteristics of the liquid and rotational speed,ω, tilt angle,θ, and diameter of the tube. Through understanding that the fluid exhibits resonance behaviours from the confining boundaries of the glass surface and the meniscus that determines the liquid film thickness, we have established specific topological mass transport regimes. These topologies have been established through materials processing, as spinning top flow normal to the surface of the tube, double-helical flow across the thin film, and spicular flow, a transitional region where both effects contribute. The manifestation of mass transport patterns within the film have been observed by monitoring the mixing time, temperature profile, and film thickness against increasing rotational speed,ω. In addition, these flow patterns have unique signatures that enable the morphology of nanomaterials processed in the VFD to be predicted, for example in reversible scrolling and crumbling graphene oxide sheets. Shear-stress induced recrystallisation, crystallisation and polymerisation, at different rotational speeds, provide moulds of high-shear topologies, as ‘positive’ and ‘negative’ spicular flow behaviour. ‘Molecular drilling’ of holes in a thin film of polysulfone demonstrate spatial arrangement of double-helices. The grand sum of the different behavioural regimes is a general fluid flow model that accounts for all processing in the VFD at an optimal tilt angle of 45°, and provides a new concept in the fabrication of novel nanomaterials and controlling the organisation of matter
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