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101.
三维地学建模技术与Kriging方法在固体矿产储量计算中的应用 总被引:4,自引:0,他引:4
结合Kriging方法在计算机上的实现和应用,介绍了运用三维地学建模技术生成矿体的三维品位模型的原理流程以及关键技术,并在此基础上进行矿产资源储最计算.其基本流程为:根据实际地质勘探数据生成矿体三维实体模型;在实体tin模型内部应用块模型方法进行划分,建立矿体块体模型;利用Kriging方法进行插值,生成矿体的品位模型... 相似文献
102.
施工企业经营风险是指企业在经营中对未来经营环境中的不确定因素与多变性无法全部或精确预测所造成预计支出与收益偏离实际的风险。企业经营风险是在经营过程中产生的,因此,经营风险贯穿于企业生产经营的全过程。 相似文献
103.
Nitrogen (N) limits the productivity of many ecosystems worldwide, thereby restricting the ability of terrestrial ecosystems to offset the effects of rising atmospheric CO(2) emissions naturally. Understanding input pathways of bioavailable N is therefore paramount for predicting carbon (C) storage on land, particularly in temperate and boreal forests. Paradigms of nutrient cycling and limitation posit that new N enters terrestrial ecosystems solely from the atmosphere. Here we show that bedrock comprises a hitherto overlooked source of ecologically available N to forests. We report that the N content of soils and forest foliage on N-rich metasedimentary rocks (350-950?mg?N?kg(-1)) is elevated by more than 50% compared with similar temperate forest sites underlain by N-poor igneous parent material (30-70?mg?N?kg(-1)). Natural abundance N isotopes attribute this difference to rock-derived N: (15)N/(14)N values for rock, soils and plants are indistinguishable in sites underlain by N-rich lithology, in marked contrast to sites on N-poor substrates. Furthermore, forests associated with N-rich parent material contain on average 42% more carbon in above-ground tree biomass and 60% more carbon in the upper 30?cm of the soil than similar sites underlain by N-poor rocks. Our results raise the possibility that bedrock N input may represent an important and overlooked component of ecosystem N and C cycling elsewhere. 相似文献
104.
基于遗传算法的管理信息系统的智能分解 总被引:1,自引:0,他引:1
将遗传算法原理应用于管理信息大系统的结构化分解,并对具体分解技术进行了详细描述,最后对一个具体实例进行了仿真计算。仿真说明,该算法具有全局快速收敛性、并行性和极高的分解效率。 相似文献
105.
Péterfy M Ben-Zeev O Mao HZ Weissglas-Volkov D Aouizerat BE Pullinger CR Frost PH Kane JP Malloy MJ Reue K Pajukanta P Doolittle MH 《Nature genetics》2007,39(12):1483-1487
Hypertriglyceridemia is a hallmark of many disorders, including metabolic syndrome, diabetes, atherosclerosis and obesity. A well-known cause is the deficiency of lipoprotein lipase (LPL), a key enzyme in plasma triglyceride hydrolysis. Mice carrying the combined lipase deficiency (cld) mutation show severe hypertriglyceridemia owing to a decrease in the activity of LPL and a related enzyme, hepatic lipase (HL), caused by impaired maturation of nascent LPL and hepatic lipase polypeptides in the endoplasmic reticulum (ER). Here we identify the gene containing the cld mutation as Tmem112 and rename it Lmf1 (Lipase maturation factor 1). Lmf1 encodes a transmembrane protein with an evolutionarily conserved domain of unknown function that localizes to the ER. A human subject homozygous for a deleterious mutation in LMF1 also shows combined lipase deficiency with concomitant hypertriglyceridemia and associated disorders. Thus, through its profound effect on lipase activity, LMF1 emerges as an important candidate gene in hypertriglyceridemia. 相似文献
106.
Receptor communication within the lymphocyte plasma membrane: a role for the thrombospondin family of matricellular proteins 总被引:1,自引:0,他引:1
Lymphocytes, the principal cells of the immune system, carry out immune surveillance throughout the body by their unique capacity
to constantly reposition themselves between a free-floating vascular state and a tissue state characterized by migration and
frequent adhesive interactions with endothelial cells and components of the extracellular matrix. Therefore, mechanisms co-ordinating
adhesion and migration with signals delivered through antigen recognition probably play a pivotal role for the regulation
of lymphocyte behaviour and function. Endogenous thrombospondin-1 (TSP-1) seems to be the hub in such a mechanism for autocrine
regulation of T cell adhesion and migration. TSP-1 functions as a mediator of cis interaction of vital receptors within the T lymphocyte plasma membrane, including integrins, low density lipoprotein receptor-related
protein, calreticulin and integrin-associated protein.
Received 1 June 2006; received after revision 28 June 2006; accepted 11 October 2006 相似文献
107.
Z. Campos F. Muniz A. L. J Desbiez W. E. Magnusson 《Journal of Natural History》2016,50(25-26):1543-1548
Nests of Schneider’s dwarf caiman, Paleosuchus trigonatus, were located in the forests around three streams that drain into the Xingu River, Brazilian Amazonia, in October 2014. Camera traps were installed at the edge of four nests to document predators and female parental care. At two nests, females unsuccessfully defended their nests against one or more giant armadillos, Priodontes maximus, and nine-banded armadillos, Dasypus novemcinctus. Both armadillo species responded to the attack by fleeing and returning on the opposite side of the nest by going around the tree under which the nest was located. Giant armadillos have never before been recorded consuming caiman eggs and their diet has been described as consisting mostly of ants and termites. Another species of armadillo, Cabassous unicinctus, was also registered digging into a nest and probably consuming eggs, though it is generally considered to be primarily insectivorous. A tayra (Eira barbara), lizard (Tupinambis teguixin) and coati (Nasua nasua) were also registered taking eggs from nests during the day, but we obtained no registers of nest defence by caimans during the day. The three nests were attacked after 60 days of incubation, when the eggs were well developed. 相似文献
108.
讨论了导体与电介质同时存在情况下的电像法问题,指出了文献[1-2]中关于这一问题所出现的一些错误,并给出了正确的解答. 相似文献
109.
Lei Chen Cong-Fa Huang Yi-Cun Li Wei-Wei Deng Liang Mao Lei Wu Wen-Feng Zhang Lu Zhang Zhi-Jun Sun 《Cellular and molecular life sciences : CMLS》2018,75(11):2045-2058
The NLRP3 inflammasome is a critical innate immune pathway responsible for producing active interleukin (IL)-1β, which is associated with tumor development and immunity. However, the mechanisms regulating the inflammatory microenvironment, tumorigenesis and tumor immunity are unclear. Herein, we show that the NLRP3 inflammasome was over-expressed in human HNSCC tissues and that the IL-1β concentration was increased in the peripheral blood of HNSCC patients. Additionally, elevated NLRP3 inflammasome levels were detected in tumor tissues of Tgfbr1/Pten 2cKO HNSCC mice, and elevated IL-1β levels were detected in the peripheral blood serum, spleen, draining lymph nodes and tumor tissues. Blocking NLRP3 inflammasome activation using MCC950 remarkably reduced IL-1β production in an HNSCC mouse model and reduced the numbers of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) and tumor-associated macrophages (TAMs). Moreover, inhibiting NLRP3 inflammasome activation increased the numbers of CD4+ and CD8+ T cells in HNSCC mice. Notably, the numbers of exhausted PD-1+ and Tim3+ T cells were significantly reduced. A human HNSCC tissue microarray showed that NLRP3 inflammasome expression was correlated with the expression of CD8 and CD4, the Treg marker Foxp3, the MDSC markers CD11b and CD33, and the TAM markers CD68 and CD163, PD-1 and Tim3. Overall, our results demonstrate that the NLRP3 inflammasome/IL-1β pathway promotes tumorigenesis in HNSCC and inactivation of this pathway delays tumor growth, accompanied by decreased immunosuppressive cell accumulation and an increased number of effector T cells. Thus, inhibition of the tumor microenvironment through the NLRP3 inflammasome/IL-1β pathway may provide a novel approach for HNSCC therapy. 相似文献
110.
Macgregor S Montgomery GW Liu JZ Zhao ZZ Henders AK Stark M Schmid H Holland EA Duffy DL Zhang M Painter JN Nyholt DR Maskiell JA Jetann J Ferguson M Cust AE Jenkins MA Whiteman DC Olsson H Puig S Bianchi-Scarrà G Hansson J Demenais F Landi MT Dębniak T Mackie R Azizi E Bressac-de Paillerets B Goldstein AM Kanetsky PA Gruis NA Elder DE Newton-Bishop JA Bishop DT Iles MM Helsing P Amos CI Wei Q Wang LE Lee JE Qureshi AA Kefford RF Giles GG Armstrong BK Aitken JF Han J Hopper JL Trent JM Brown KM 《Nature genetics》2011,43(11):1114-1118
We performed a genome-wide association study of melanoma in a discovery cohort of 2,168 Australian individuals with melanoma and 4,387 control individuals. In this discovery phase, we confirm several previously characterized melanoma-associated loci at MC1R, ASIP and MTAP-CDKN2A. We selected variants at nine loci for replication in three independent case-control studies (Europe: 2,804 subjects with melanoma, 7,618 control subjects; United States 1: 1,804 subjects with melanoma, 1,026 control subjects; United States 2: 585 subjects with melanoma, 6,500 control subjects). The combined meta-analysis of all case-control studies identified a new susceptibility locus at 1q21.3 (rs7412746, P = 9.0 × 10(-11), OR in combined replication cohorts of 0.89 (95% CI 0.85-0.95)). We also show evidence suggesting that melanoma associates with 1q42.12 (rs3219090, P = 9.3 × 10(-8)). The associated variants at the 1q21.3 locus span a region with ten genes, and plausible candidate genes for melanoma susceptibility include ARNT and SETDB1. Variants at the 1q21.3 locus do not seem to be associated with human pigmentation or measures of nevus density. 相似文献