962 resultados para 129-801


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Knowledge of the subduction input flux of nitrogen (N) in altered oceanic crust (AOC) is critical in any attempt to mass-balance N across arc-trench systems on a global or individual-margin basis. We have employed sealed-tube, carrier-gas-based methods to examine the N concentrations and isotopic compositions of AOC. Analyses of 53 AOC samples recovered on DSDP/ODP legs from the North and South Pacific, the North Atlantic, and the Antarctic oceans (with larger numbers of samples from Site 801 outboard of the Mariana trench and Site 1149 outboard of the Izu trench), and 14 composites for the AOC sections at Site 801, give N concentrations of 1.3 to 18.2 ppm and d15N_air of -11.6? to +8.3?, indicating significant N enrichment probably during the early stages of hydrothermal alteration of the oceanic basalts. The N-d15N modeling for samples from Sites 801 and 1149 (n=39) shows that the secondary N may come from (1) the sedimentary N in the intercalated sediments and possibly overlying sediments via fluid-sediment/rock interaction, and (2) degassed mantle N2 in seawater via alteration-related abiotic reduction processes. For all Site 801 samples, weak correlation of N and K2O contents indicates that the siting of N in potassic alteration phases strongly depends on N availability and is possibly influenced by highly heterogeneous temperature and redox conditions during hydrothermal alteration. The upper 470-m AOC recovered by ODP Legs 129 and 185 delivers approximately 800 kg/km N annually into the Mariana margin. If the remaining less-altered oceanic crust (assuming 6.5 km, mostly dikes and gabbros) has MORB-like N of 1.5 ppm, the entire oceanic crust transfers 5100 kg/km N annually into that trench. This N input flux is twice as large as the annual N input of 2500 kg/km in seafloor sediments subducting into the same margin, demonstrating that the N input in oceanic crust, and its isotopic consequences, must be considered in any assessment of convergent margin N flux.

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Between 1995 and 2003, 129 cemented primary THRs were performed using full acetabular impaction grafting to reconstruct acetabular deficiencies. These were classified as cavitary in 74 and segmental in 55 hips. Eighty-one patients were reviewed at mean 9.1 (6.2-14.3) years post-operatively. There were seven acetabular component revisions due to aseptic loosening, and a further 11 cases that had migrated >5mm or tilted >5° on radiological review - ten of which reported no symptoms. Kaplan-Meier analysis of revisions for aseptic loosening demonstrates 100% survival at nine years for cavitary defects compared to 82.6% for segmental defects. Our results suggest that the medium-term survival of this technique is excellent when used for purely cavitary defects but less predictable when used with large rim meshes in segmental defects.

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This article reviews the nature and purpose of s 129 of the Property Law Act 1974 (Qld) whose application has given rise to some confusion in the past, particularly where the lessee against whom it is being used is also in breach of the lease at the time of receiving the notice. The article explores the historical origins of the section, firstly in New South Wales where it was enacted in 1930, and attempts to outline modern circumstances where it may be applied or particularly applied in Queensland.

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Bentonite is a preferred buffer and backfill material for deep geological disposal of high-level nuclear waste (HLW). Bentonite does not retain anions by virtue of its negatively charged basal surface. Imparting anion retention ability to bentonite is important to enable the expansive clay to retain long-lived I-129 (iodine-129; half-life = 16 million years) species that may escape from the HLW geological repository. Silver-kaolinite (AgK) material is prepared as an additive to improve the iodide retention capacity of bentonite. The AgK is prepared by heating kaolinite-silver nitrate mix at 400 degrees C to study the kaolinite influence on the transition metal ion when reacting at its dehydroxylation temperature. Thermo gravimetric-Evolved Gas Detection analysis, X-ray diffraction analysis, X-ray photo electron spectroscopy and electron probe micro analysis indicated that silver occurs as AgO/Ag2O surface coating on thermally reacting kaolinite with silver nitrate at 400 degrees C.

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Background: Sporadic Creutzfeldt-Jakob disease (sCJD) is a rare neurodegenerative disorder in humans included in the group of Transmissible Spongiform Encephalopathies or prion diseases. The vast majority of sCJD cases are molecularly classified according to the abnormal prion protein (PrPSc) conformations along with polymorphism of codon 129 of the PRNP gene. Recently, a novel human disease, termed "protease-sensitive prionopathy", has been described. This disease shows a distinct clinical and neuropathological phenotype and it is associated to an abnormal prion protein more sensitive to protease digestion. Case presentation: We report the case of a 75-year-old-man who developed a clinical course and presented pathologic lesions compatible with sporadic Creutzfeldt-Jakob disease, and biochemical findings reminiscent of "protease-sensitive prionopathy". Neuropathological examinations revealed spongiform change mainly affecting the cerebral cortex, putamen/globus pallidus and thalamus, accompanied by mild astrocytosis and microgliosis, with slight involvement of the cerebellum. Confluent vacuoles were absent. Diffuse synaptic PrP deposits in these regions were largely removed following proteinase treatment. PrP deposition, as revealed with 3F4 and 1E4 antibodies, was markedly sensitive to pre-treatment with proteinase K. Molecular analysis of PrPSc showed an abnormal prion protein more sensitive to proteinase K digestion, with a five-band pattern of 28, 24, 21, 19, and 16 kDa, and three aglycosylated isoforms of 19, 16 and 6 kDa. This PrPSc was estimated to be 80% susceptible to digestion while the pathogenic prion protein associated with classical forms of sporadic Creutzfeldt-Jakob disease were only 2% (type VV2) and 23% (type MM1) susceptible. No mutations in the PRNP gene were found and genotype for codon 129 was heterozygous methionine/valine. Conclusions: A novel form of human disease with abnormal prion protein sensitive to protease and MV at codon 129 was described. Although clinical signs were compatible with sporadic Creutzfeldt-Jakob disease, the molecular subtype with the abnormal prion protein isoforms showing enhanced protease sensitivity was reminiscent of the "protease-sensitive prionopathy". It remains to be established whether the differences found between the latter and this case are due to the polymorphism at codon 129. Different degrees of proteinase K susceptibility were easily determined with the chemical polymer detection system which could help to detect proteinase-susceptible pathologic prion protein in diseases other than the classical ones.

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This paper tries to develop more generally some fundamental bases for the ecological study of freshwater plankton. A special attention is given to the phytoplankton associations which can be separated out and made into groups according to their dependence upon changing environments. Plankton formations in different types of water bodies (ponds, lakes and rivers) are studied.

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Monkeys have strong abilities to remember the visual properties of potential food sources for survival in the nature. The present study demonstrated the first observations of rhesus monkeys learning to solve complex spatial mazes in which routes were guid

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土壤有机碳、全氮的空间分布及特性研究一直是土壤学研究的热点,研究东北黑土有机碳、全氮的空间分布和特性可以为东北黑土退化机理及可持续利用提供理论依据。本文以东北黑土区1200个样点为基础,依据尺度分布理论,采用宏观统计分析和微观化学分析相结合,研究了黑土有机碳、全氮空间分布规律;黑土有机碳与其它养分之间的关系;黑土有机碳、全氮在团聚体中的富集以及黑土活性有机碳、氮的区域分布特性。本次研究是继第二次土壤普查以来对黑土有机碳系统研究,首次摸清了东北黑土有机碳库的现状和分布规律,及其与其它养分库的关系,采用经典统计学方法绘制了黑土有机碳空间分布图;对影响有机碳库和养分的驱动因素进行了分析,发现了黑土有机碳库的“经向”和“纬向”分布规律;总结了黑土有机碳库频数分布特征,以及自第二次土壤普查以来几十年间的变化。探讨了土壤有机碳空间分布的驱动因子,绘制了土壤有机碳、全氮的空间分布等值线图,阐明了土壤活性有机碳、氮库的空间分布对土壤有机碳库的贡献: 1、土壤有机碳、全氮水平空间分布在纬向上主要受温度控制,在经向上主要受水分控制,黑土有机碳与纬度的显著相关(r=0.70188, P<0.01),与黏粒显著正相关(r=0.43, P<0.01),与砂粒显著负相关(r=-0.44, P<0.01)。 2、土壤有机碳、全氮垂直空间分布在一定深度内受温度控制,水分状况作用较小,黏粒在深度剖面作用不显著,随着土壤深度的增加,土壤有机C和全N含量降低。 3、土壤团聚体组分中有机碳、全氮含量与纬度呈正相关关系,大团聚体和微团聚体更易受水热条件影响,大团聚体的有机碳富集因子E≥1的趋势明显而微团聚体及粉+黏组分有机碳的富集因子E≤1的趋势明显,说明大团聚体中有机碳具有累积趋势而微团聚体和粉+黏组分中有机碳处于消耗状态。 4、黑土其它养分的分布均非正态分布,有机碳与全磷、全钾、碱解氮、速效钾和速效磷之间的相关关系分别为0.795、-0.295、0.801、0.244和0.036,只有有机碳和速效磷之间没有相关性,而与其它养分在P<0.01水平呈显著相关。 5、土壤活性有机碳和活性有机氮随纬度增加活性组分增大,土壤活性有机碳的比例较小,说明黑土有机物料输入较低;黑土活性有机氮含量差别不大,说明微生物活动相似。