基于遥感的黄土丘陵沟壑区人口密度分布模拟——以甘肃省榆中县为例

基于“面向对象”的人口分配原则,通过扩展的城市人口-面积异速生长模型,以SPOT5遥感影像为基本数据源,提取居民地信息;以榆中县为例,建立居民地分类体系,采取城乡人口分割算法,以人口统计数据为总量控制建立了人口分布的反演模型,模拟了榆中县域人口的空间分布。研究方法可为黄土丘陵沟壑区中尺度人口分布模拟的理论与应用研究提供借鉴。     

Genetics of photoreceptor degeneration and regeneration in zebrafish

Zebrafish are unique in that they provide a useful model system for studying two critically important problems in retinal neurobiology, the mechanisms responsible for triggering photoreceptor cell death and the innate stem cell–mediated regenerative response elicited by this death. In this review we highlight recent seminal findings in these two fields. We first focus on zebrafish as a model for studying photoreceptor degeneration. We summarize the genes currently known to cause photoreceptor degeneration, and we describe the phenotype of a few zebrafish mutants in detail, highlighting the usefulness of this model for studying this process. In the second section, we discuss the several different experimental paradigms that are available to study regeneration in the teleost retina. A model outlining the sequence of gene expression starting from the dedifferentiation of Müller glia to the formation of rod and cone precursors is presented.     

Rapid isolation of mitochondrial DNA. Mitochondrial DNA fromDrosophila serrata

A simple and rapid method for isolation of high quality mitochondrial DNA (mtDNA) is presented in this report. Using this method, isolation and restriction site maps for 10 enzymes of the mtDNA ofDrosophila serrata were established.     

基于DSP和CPLD的电力数据远程通讯系统设计

本文根据电力数据的特点,提出了一种新的电力数据压缩处理方案。首先对电力数据进行预处理,然后再用自适应Huffman编码对实时采集的电力数据进行压缩。通过对比测试结果,本文给出了运用此处理方案的效果仿真图。最后提出了基于DSP和CPLD的电力数据远程通讯的设计方案,该方案简单易行,适合电力系统,为本算法的移植打下了基础。     

The five problems of irreversibility

Thermodynamics has a clear arrow of time, characterized by the irreversible approach to equilibrium. This stands in contrast to the laws of microscopic theories, which are invariant under time-reversal. Foundational discussions of this “problem of irreversibility” often focus on historical considerations, and do therefore not take results of modern physical research on this topic into account. In this article, I will close this gap by studying the implications of dynamical density functional theory (DDFT), a central method of modern nonequilibrium statistical mechanics not previously considered in philosophy of physics, for this debate. For this purpose, the philosophical discussion of irreversibility is structured into five problems, concerned with the source of irreversibility in thermodynamics, the definition of equilibrium and entropy, the justification of coarse-graining, the approach to equilibrium and the arrow of time. For each of these problems, it is shown that DDFT provides novel insights that are of importance for both physicists and philosophers of physics.     

Formation of carthamin by a partially purified enzyme from safflower seedlings

Summary An enzyme responsible for synthesizing carthamin from precarthamin was partially purified and the catalytic properties were investigated.Acknowledgments. The authors wish to thank Prof. A. Komamine, University of Tokyo, for reading this paper. We are indebted to Prof. A. Saito, Tokai University, for performing emission spectrochemical analysis of the enzyme protein used in this study.     

The plasma membrane proton-translocating ATPase

Living cells require membranes and membrane transporters for the maintenance of life. After decades of biochemical scrutiny, the structures and molecular mechanisms by which membrane transporters catalyze transmembrane solute movements are beginning to be understood. The plasma membrane proton-translocating adenosine triphosphatase (ATPase) is an archetype of the P-type ATPase family of membrane transporters, which are important in a wide variety of cellular processes. The H+-ATPase has been crystallized and its structure determined to a resolution of 8 angstrom in the membrane plane. When considered together with the large body of biochemical information that has been accumulated for this transporter, and for enzymes in general, this new structural information is providing tantalizing insights regarding the molecular mechanism of active ion transport catalyzed by this enzyme.     

The possible role of glutamine in some cells of the immune system and the possible consequence for the whole animal

Glutamine is important for the function of lymphocytes and macrophages. A role for the high rate of glutamine utilisation by these cells is presented. Since muscle syntheses, stores and releases glutamine, this tissue may play a role in the immune response. Since the number of immune cells utilising glutamine may be large, the demand for glutamine from muscle, especially during trauma sepsis or burns, may be very high. A speculative suggestion is put forward that this requirement for glutamine from muscle may play a role in cachexia under some of these conditions.     

Correcting the January optimism effect

Each month, various professional forecasters give forecasts for next year's real gross domestic product (GDP) growth and unemployment. January is a special month, when the forecast horizon moves to the following calendar year. Instead of deleting the January data when analyzing forecast updates, I propose a periodic version of a test regression for weak-form efficiency. An application of this periodic model for many forecasts across a range of countries shows that in January GDP forecast updates are positive, whereas the forecast updates for unemployment are negative. I document that this January optimism about the new calendar year is detrimental to forecast accuracy. To empirically analyze Okun's law, I also propose a periodic test regression, and its application provides more support for this law.     

Rapid isolation of mitochondrial DNA. Mitochondrial DNA from Drosophila serrata.

A simple and rapid method for isolation of high quality mitochondrial DNA (mtDNA) is presented in this report. Using this method, isolation and restriction site maps for 10 enzymes of the mtDNA of Drosophila serrata were established.     

Detecting and Predicting Economic Accelerations,Recessions, and Normal Growth Periods in Real‐Time

The dichotomous characterization of the business cycle in recessions and expansions has been central in the literature over the last 50 years. However, there are various reasons to question the adequacy of this dichotomous, recession/expansion approach for our understanding of the business cycle dynamics, as well as for the prediction of future business cycle developments. In this context, the contribution of this paper to the literature is twofold. First, since a positive rate of growth at the level of economic activity can be considered as the normal scenario in modern economies due to both population and technological growth, it proposes a new non‐parametric algorithm for the detection and dating of economic acceleration periods, trend or normal growth periods, and economic recessions. Second, it uses an ordered probit framework for the estimation and forecasting of these three business cycle phases, applying an automatized model selection approach using monthly macroeconomic and financial data on the German economy. The empirical results show that this approach has superior out‐of‐sample properties under real‐time conditions compared to alternative probit models specified individually for the prediction of recessions and/or economic accelerations. Copyright © 2016 John Wiley & Sons, Ltd.     

非正态总体卞的EWMA控制图

主要讨论了非正态分布情况下EWMA图的效率分析和优化设计问题。首先引入赋权方差法将非正态总体转换为正态过程,由此构造适用于非正态总体的EWMA图,然后以平均产品长度作为效率度量时非正态EWMA控制图进行了优化设计。通过与其他几种方法的比较说明该方法在监控非正态总体中出现的较小波动时具有的优势。     

MAPK pathway activation in pilocytic astrocytoma

Pilocytic astrocytoma (PA) is the most common tumor of the pediatric central nervous system (CNS). A body of research over recent years has demonstrated a key role for mitogen-activated protein kinase (MAPK) pathway signaling in the development and behavior of PAs. Several mechanisms lead to activation of this pathway in PA, mostly in a mutually exclusive manner, with constitutive BRAF kinase activation subsequent to gene fusion being the most frequent. The high specificity of this fusion to PA when compared with other CNS tumors has diagnostic utility. In addition, the frequency of alteration of this key pathway provides an opportunity for molecularly targeted therapy in this tumor. Here, we review the current knowledge on mechanisms of MAPK activation in PA and some of the downstream consequences of this activation, which are now starting to be elucidated both in vitro and in vivo, as well as clinical considerations and possible future directions.     

Effect of thiamine hydrochloride on the blood level of 2-formyl 1-methyl pyridinium oxime chloride (2-PAM.Cl) in rats

Summary The biological half-life of 2-PAM.Cl was found to increase in female rats pretreated with thiamine hydrochloride (10 mg/kg i.m.). No such effect was observed in the male rats.Dr B.L. Chowdhri very kindly synthesized the compound 2-PAM.Cl in the Department of Chemistry of this establishment for this work.The authors are thankful to Dr P.K. Ramachandran, Director, and Dr A.K. Chatterjee, Deputy Director, Defence Research and Development Establishment, Gwalior, for their keen interest in this work.     

面向装配的复杂模型几何及结构轻量化技术研究

复杂三维模型轻量化是节约存储空间、加快处理速度和实现信息隐藏的有效途径.为了快速有效地生成装配体的轻量化模型,提出了一套面向装配的复杂模型轻量化算法框架及处理流程,以零部件抑制、基于特征缝合的模型表面处理和模型整体抽壳等关键技术为手段,实现了复杂装配模型几何与结构的简化表示.该算法已顺利地运用到相关企业的装配设计,模型轻量化效率比较高,为复杂装配模型的网络协同设计和运动仿真等后续应用提供了一种有益的途径.     

Model‐based forecast adjustment: With an illustration to inflation

This paper introduces the idea of adjusting forecasts from a linear time series model where the adjustment relies on the assumption that this linear model is an approximation of a nonlinear time series model. This way of creating forecasts could be convenient when inference for a nonlinear model is impossible, complicated or unreliable in small samples. The size of the forecast adjustment can be based on the estimation results for the linear model and on other data properties such as the first few moments or autocorrelations. An illustration is given for a first‐order diagonal bilinear time series model, which in certain properties can be approximated by a linear ARMA(1, 1) model. For this case, the forecast adjustment is easy to derive, which is convenient as the particular bilinear model is indeed cumbersome to analyze in practice. An application to a range of inflation series for low‐income countries shows that such adjustment can lead to some improved forecasts, although the gain is small for this particular bilinear time series model.