改进的GM(1,1)模型对内蒙古自治区手足口病高峰期发病率预测

以内蒙古自治区2009~2016年手足口病每年的高发月5~7月的发病数据为研究数据,分别建立自回归移动平均求和(Autoregressive Integrated Moving Average Model,ARIMA)模型与GM(1,1)灰色模型,对内蒙古自治区手足口病的高发月9岁以下儿童发病率进行拟合与预测,两种单一模型预测结果显示,GM(1,1)模型的预测精度高于ARIMA模型。为降低数据波动性对GM(1,1)模型预测效果的影响,文中基于弱化缓冲算子对GM(1,1)模型进行了改进,改进的GM(1,1)模型具有较大的灵活性且提高了传统GM(1,1)模型的预测精度。     

GM(1,1)模型残差修正的探讨

近年来,灰色系统理论在农业病虫害预测中已得到广泛应用,其中最易为人接受的GM（1,1）模型已经在实践中取得可喜的成就。但是灰色系统理论作为一门新兴学科,在实际应用中,还有不少理论问题有待于研究。本文就GM（l,呈）预测模型建模过程中出现的有关残差修正问题作了如下有益的探讨。1GM（1,1）预测模型现以“褐稻虱灰色灾变长期预测初探”（吕雨土,昆虫知识26（5）：257～260）一文为例,加以说明。文章采用浙江街县1974～1986年晚稻田间揭稻虱发生量的历史资料,对原始资料规定加权平均最高时百丛虫量达2000只为灾年,不到刘如…     

用GM(n,h)模型预测森林资源发展趋势

应用灰色系统理论,对森林资源的主要指标进行了预测,建立了灰色动态预测模型GM（1,1）．其预测结果误差小,精度高,为林业宏观决策,森林经营管理提供了科学依据和方法．     

宝安区结核病控制策略的初步分析

目的:评价宝安区实施结核病控制(DOTS)策略的效果.方法:利用宝安区结核病控制有关资料进行分析.结果:宝安区在组织机构建设、流动人口管理、专项经费落实、人员培训等方面取得了积极的成果.特有的宝安结核病控制提高了防治的社会效益和经济效益,为降低宝安区结核病的疫情发挥了重要的作用.结论:通过国家重大专项,全面实施新的DOTS策略必将有力地推动了宝安区的结核病防治工作,从而为在全国范围内推广提供基础和依据.     

应用ARIMA模型预测宝安区某街道其它感染性腹泻发病率的探讨

目的:探讨应用ARIMA模型预测宝安区某街道其它感染性腹泻发病率的可行性。方法:应用SPSSl3.0软件对2005年～2009年宝安区某街道其它感染性腹泻逐月发病率进行ARIMA模型建模拟合,用所得到的模型对2010年各月发病率进行预测,并评价其预测效果。结果:宝安区桌街道其它感染性腹泻发病率每年11月为发病高峰,ARIMA(0,1,1)(0,1,0)12模型是其拟合的最佳模型,其预测结果和实际值绝对误差的绝对值最大为930.47,最小为1.96,平均值214.83,平均相对误差百分比39.04%。结论:模型虽然起到一定的预测效果,但预测精度仍存在误差,可通过积累新的周期数据对ARIMA模型进行修正和重新拟合,也可尝试新的预测方法或其他模型,才能加强和保证预测的精度。     

应用ARIMA模型预测宝安区某街道其它感染性腹泻发病率的探讨

目的：探讨应用ARIMA模型预测宝安区某街道其它感染性腹泻发病率的可行性。方法：应用SPSS13．0软件对2005年～2009年宝安区某街道其它感染性腹泻逐月发病率进行ARIMA模型建模拟合,用所得到的模型对2010年各月发病率进行预测,并评价其预测效果。结果：宝安区某街道其它感染性腹泻发病率每年11月为发病高峰,ARIMA（0,1,1）（0,1,0）12模型是其拟合的最佳模型,其预测结果和实际值绝对误差的绝对值最大为930．47,最小为1．96,平均值214．83,平均相对误差百分比39．04％。结论：模型虽然起到一定的预测效果,但预测精度仍存在误差,可通过积累新的周期数据对ARIMA模型进行修正和重新拟合,也可尝试新的预测方法或其他模型,才能加强和保证预测的精度。     

三种预测林木生长量方法的比较

本研究选择了三种方法灰色GM(1,1)模型法、回归法、灰色线性回归组合模型法,经过数据的加载,灰色GM(1,1)为Ⅱ级合格模型,发展系数|a|＜0.3可用于中长期预测;在回归法中选用5个模型进行拟合,以Richards方程的复相关系高,残差平方和最小,被选中;灰色线性回组合模型达到Ⅲ级勉强可用模型.用三个模型分别对32、34龄阶的生长量进行预测,其平均相对精度分别为94.64%、80.68%、92.41%.     

基于改进TOPSIS-灰色GM(1,1)模型的张家界市旅游生态安全动态预警

旅游生态安全预警对旅游地协调生态环境保护与旅游产业快速发展的矛盾,推进区域社会经济持续健康发展具有重要意义.本文基于DPSIR模型,从驱动力、压力、状态、影响、响应5方面构建了张家界市旅游生态安全预警指标体系,在此基础上,运用改进TOPSIS法对2001—2014年张家界市的旅游生态安全警情格局进行评估,并运用灰色GM(1,1)模型对其2015—2020年的警情演变趋势进行预测.结果表明: 总体上,2001—2014年,张家界市的旅游生态安全贴近度呈略微上升态势,警度处于“中警”.就各子系统而言,2001—2014年,张家界市旅游生态安全驱动力系统和压力系统的警度呈上升趋势,由“轻警”演变成“重警”;状态系统和影响系统的警度变化不大,一直处于“中警”;响应系统的警度呈下降趋势,由“巨警”转变成“无警”.按现状发展态势,2015—2020年,张家界市的旅游生态安全贴近度将进一步上升,警度将由“中警”向“轻警”转变,但协调旅游发展与生态建设和环境保护关系的任务依然较艰巨.     

普陀山岛旅游生态安全发展趋势预测

科学地预测海岛目的地旅游生态安全发展趋势,对促进海岛旅游经济和生态环境协调发展具有重要的理论意义和实践价值。基于可持续发展的视角,建立了由承载力-支持力-吸引力-延续力和发展力(CSAED模型)子系统构成的普陀山旅游生态安全指标体系,并在灰色系统GM(1,1)模型和RBF神经网络模型比较选优的基础上,对普陀山岛旅游生态安全发展趋势进行了预测。研究结果表明:(1)和灰色系统GM(1,1)模型相比,RBF神经网络模型的Pearson相关系数和误差均方根值更优,可更精确地拟合普陀山岛旅游生态安全发展趋势;(2)2015—2020年,普陀山岛旅游生态安全指数的RBF神经网络模型预测结果由0.7017增加至0.8135,安全等级由比较安全上升至非常安全。研究结果可为维护普陀山岛旅游生态安全提供决策依据。     

基于GM(1,1)组合模型的小麦条锈病预测方法研究

小麦条锈病的预测是制定小麦条锈病防治方案的重要组成部分.鉴于小麦条锈病病害系统的复杂性和灰色性,首先用Brown指数平滑法和灰色预测建立了甘肃天水地区1995年到2003年的普遍率的单项预测模型,然后采用预测残差方差最小的原则进行优化组合,从而获得更为精确的预测模型和预测值,拟合率达到94.5%.     

灰色GM~*(1,l)模型的性质及其应用

灰色GM（l，l）模对生态预测有重要应用，本文讨论了它的一个改进模GM*（l，1），并深化了文[l]提出的两个问题，给出了较简明的证法，还确定了文[1]所希望的一个“合适的”常数．     

Let them eat (GM) straw

Approximately half of aboveground biomass of grain crops (straw) is wasted, with negative ecological and economic impact. Straw use could increase animal production by at least one third if lignin could be transgenically decreased or modified, rendering more carbohydrate available to ruminant animals. Such digestible straw can be upgraded by ammonification, which further separates lignin and serves as a nitrogen source for ruminant bacteria, or biotreatment with ligninolytic fungi and/or physical treatments. Such technologies could supply animal protein to an increasing population, while releasing more grain for direct human consumption without the need to put more land under plough.     

Equivalent Circuit Method Analysis of Graphene-Metamaterial (GM) Absorber

This paper presents an effective method to model and analyze graphene-metamaterial (GM) absorbers by using an equivalent circuit model. A reliable and closed formula to describe the absorption mechanism of the GM structure was derived from this approach. With the obtained expressions, the effect of the graphene chemical potential on the absorber’s resonance frequency is able to be predicted. In order to verify this proposed equivalent circuit method, an absorber consists of metamaterial and graphene was simulated and the physical mechanism was well explained. This method provides an effective way to analyze multilayered GM absorbers for the future.     

Serum lipoproteins inhibitors of granulocyte-macrophage (GM) colony formation

Normal and chloroform-extracted human sera, fractionated by Sephadex column chromatography, were tested for inhibitory activity on granulocyte-macrophage (GM) colony formation. This activity was found to be connected with lipoproteins with a molecular weight of about 200,000. Serum native fractions of lipoproteins were isolated and mainly high density lipoproteins (HDL) and very low density lipoproteins (VLDL) were shown to have an unspecific inhibitory activity directed on colony stimulating factor (CSF) action.     

Expression machinery of GM4: the excess amounts of GM3/GM4S synthase (ST3GAL5) are necessary for GM4 synthesis in mammalian cells

The ganglioside GM4 is a sialic acid-containing glycosphingolipid mainly expressed in mammalian brain and erythrocytes. GM4 is synthesized by the sialylation of galactosylceramide (GalCer), while the ganglioside GM3 is synthesized by the sialylation of lactosylceramide (LacCer). Recently, the enzyme GM3 synthase was found to be responsible for the synthesis of GM4 in vitro and in vivo, yet the mechanism behind GM4 expression in cells remains unclear. In this study, we attempted to establish GM4-reconstituted cells to reveal the regulation of GM4 synthesis. Interestingly, GM4 was not detected in RPMI 1846 cells expressing LacCer, GalCer, and GM3. Similarly, GM4 was not detected in CHO-K1 cells, even when such cells expressing LacCer and GM3 were stably transfected with the GalCer synthase (GalCerS) gene. GM4 became detectable only when the GM3/GM4 synthase (GM3/GM4S, ST3GAL5) gene was overexpressed in either RPMI 1846 or CHO-K1/GalCerS cells. A mutant of the B16 melanoma cell line, GM-95, lacks GlcCer and LacCer, due to an absence of GlcCer synthase, but carries endogenous LacCer synthase and GM3/GM4S. GalCer became detectable after transfection of GalCerS into GM95 cells, but the GM95/GalCerS reconstituted cells did not express GM4, indicating that competition between the substrates LacCer and GalCer for GM3/GM4S does not cause the failure of GM4 synthesis. These results suggest that the expression machinery of GM4 under physiological conditions is independent from that of GM3.     

1,1-Difluoroethyl-substituted triazolothienopyrimidines as inhibitors of a human urea transport protein (UT-B): New analogs and binding model

The kidney urea transport protein UT-B is an attractive target for the development of small-molecule inhibitors with a novel diuretic (‘urearetic’) action. Previously, two compounds in the triazolothienopyrimidine scaffold (1a and 1c) were reported as UT-B inhibitors. Compound 1c incorporates a 1,1-difluoroethyl group, which affords improved microsomal stability when compared to the corresponding ethyl-substituted compound 1a. Here, a small focused library (4a–4f) was developed around lead inhibitor 1c to investigate the requirement of an amidine-linked thiophene in the inhibitor scaffold. Two compounds (4a and 4b) with nanomolar inhibitory potency (IC₅₀ ≈ 40 nM) were synthesized. Computational docking of lead structure 1c and 4a–4f into a homology model of the UT-B cytoplasmic surface suggested binding with the core heterocycle buried deep into the hydrophobic pore region of the protein.     

Accelerated release of exosome-associated GM1 ganglioside (GM1) by endocytic pathway abnormality: another putative pathway for GM1-induced amyloid fibril formation

Exosomes are extracellularly released small vesicles that are derived from multivesicular bodies formed via the endocytic pathway. We treated pheochromocytoma PC12 cells with chloroquine, an acidotropic agent, which potently perturbs membrane trafficking from endosomes to lysosomes. Chloroquine treatment increased the level of GM1 ganglioside in cell media only when the cells were exposed to KCl for depolarization, which is known to enhance exosome release from neurons. In the sucrose-density-gradient fractionation of cell media, GM1 ganglioside was exclusively recovered with Alix, a specific marker of exosomes, in the fractions with the density corrresponding to that of exosomes. Notably, amyloid-β assembly was markedly accelerated when incubated with the exosome fraction prepared from the culture media of PC12 cells treated with chloroquine and KCl. Furthermore, amyloid-β assembly was significantly suppressed by the co-incubation with an antibody specific to GM1-bound amyloid-β, an endogenous seed for amyloid formation of Alzheimer's disease. Together with our previous finding that chloroquine treatment induces the accumulation of GM1 ganglioside in early endosomes, results of this study suggest that endocytic pathway abnormality accelerates the release of exosome-associated GM1 ganglioside following its accumulation in early endosomes. Furthermore, this study also suggests that extracellular amyloid fibril formation is induced by not only GM1 gangliosides accumulated on the surface of the cells but also those released in association with exosomes.