A note on the predictive power of survey data in nowcasting euro area GDP

This paper investigates the trade‐off between timeliness and quality in nowcasting practices. This trade‐off arises when the frequency of the variable to be nowcast, such as gross domestic product (GDP), is quarterly, while that of the underlying panel data is monthly; and the latter contains both survey and macroeconomic data. These two categories of data have different properties regarding timeliness and quality: the survey data are timely available (but might possess less predictive power), while the macroeconomic data possess more predictive power (but are not timely available because of their publication lags). In our empirical analysis, we use a modified dynamic factor model which takes three refinements for the standard dynamic factor model of Stock and Watson (Journal of Business and Economic Statistics, 2002, 20, 147–162) into account, namely mixed frequency, preselections and cointegration among the economic variables. Our main finding from a historical nowcasting simulation based on euro area GDP is that the predictive power of the survey data depends on the economic circumstances; namely, that survey data are more useful in tranquil times, and less so in times of turmoil.     

First record of genus Promalactis Meyrick (Lepidoptera: oecophoridae) from Cambodia with five new species

In this study, species of the genus Promalactis found in Cambodia are reviewed for the first time. Five new species, P. infundibulina sp. nov., P. prolixa sp. nov., P. seimana sp. nov., P. serratiola sp. nov., P. spiraliola sp. nov., are described. Promalactis albisquama Kim and Park is also newly discovered in Cambodia. Illustrations of adults and genitalia of each species are also provided with distributional data.

www.zoobank.org/urn:lsid:zoobank.org:pub:88AF790D-B677-498F-20A5B4-F287B5D52318     

The role of dietary carbohydrates in organismal aging

Carbohydrates are essential nutrients that are used as a primary source of energy. Carbohydrate utilization should be properly controlled, as abnormal regulation of carbohydrate metabolism is associated with diseases, such as diabetes, cardiovascular diseases, and stroke. These metabolic syndromes have become a serious problem in developed countries, and there is an increased need for research examining the influence of carbohydrates on animal physiology. Diets enriched in glucose, a major carbohydrate, are also associated with accelerated aging in several model organisms, including yeast and Caenorhabditis elegans (C. elegans). Genetic factors that mediate the effects of high glucose diets on aging have been identified during the last decade, mostly through the use of C. elegans. In this review, we describe studies that determine the effects of carbohydrate-enriched diets on aging by focusing on the mechanisms through which evolutionarily conserved pathways mediate the lifespan-altering effects of glucose in C. elegans. These include the insulin/insulin-like growth factor-1, sterol-regulatory element-binding protein, and AMP-activated protein kinase signaling pathways. We also discuss the effects of various carbohydrates and carbohydrate-derived metabolites on aging in model organisms and cultured mammalian cells. Finally, we discuss how dietary carbohydrates influence health and aging in humans.     

A cloud based fuzzy approach for spatial site selection  in decision support system 

In decision support system for spatial site selection, the fuzzy synthetic evaluation is a useful way. However, the method can’t pay attention to the randomness in factors. To remedy the problem, this paper proposes a cloudedbase fuzzy approach which combines advantages of cloud transform and fuzzy synthetic evaluation. The cloud transform considers the randomness in the factors and product the higher concept layer for data mining. At the same time, the check mechanism controls the quality of partitions in factors. Then the fuzzy approach was used to get final evaluation value with randomness and fuzziness. It make the final result is optimization. Finally, performance evaluations show that this approach spent less runtime and got more accuracy than the fuzzy synthetic. The experiments prove that the proposed method is faster and more accuracy than the original method.     

一种基于Jacket矩阵变换的扩频序列

提出了一种基于Jacket矩阵变换的扩频序列，给出了该序列的产生电路。理论分析和实验证明该序列具有零互相关特性，使用该序列的CDMA通信系统具有良好的抗用户间串扰能力。因此，Jacket矩阵变换的扩频序列设计方法具有重要的理论意义和广泛的应用价值。     

Sedimentary environments of the Cenozoic sedimentary debris found in the moraines of the Grove Mountains, east Antarctica and its climatic implications

During the field work of the 1998～1999's and 1999～2000's Chinese National Antarctic Research Expedition (CHNARE) in the Grove Mountains, east Antarctica, some Cenozoic sedimentary debris are found in two terminal moraine banks over the blue ice near Harding Mount in the center of this region. All the debris are of characteristics of glaciogenic diamicton and belong to the products of the glacial movements of the East Antarctic Ice Sheet. In this paper, the authors make a detailed study on the sedimentary environments of the sedimentary debris through petrologic, sedimentological, mineralogical, and geo-chemical methods. Characteristics of their sedimentary textures and structures, grain size distributions, quartz grains' surface textures and features, together with their geo-chemical compositions all show that these sedimentary rocks are a kind of subglacial lodgement tills which are deposited in the ice sheet frontal area by reactions of glacial movements and glaciogenic melt water. Their palaeoenvironmental implications in revealing the retreat history of East Antarctic Ice Sheet are discussed. The authors draw the conclusion from current study that the glacial frontal of the East Antarctica Ice Sheet might have been retreated to this area during the Pliocene Epoch, which represents a warm climate event accompanied by a large-scale ice sheet retreat in Antarctica at that time.     

Dynamical Suppression of Magnetic Tunneling

Introduction　　Macroscopicquantumphenomena(MQP)havebeeninvestigatedintensivelyformanyyears.AccordingtothepioneeringworksofCaldeiraandLeggett[1,2],ifthedissipationinteractionwiththeenvironmentwassmallenough,quantumtunnelingcouldtakeplaceonthemacroscopicscale.Overthelastfifteenyears,alotofexperimentalandtheoreticalworkhavebeendevotedtothisfield.Recently,owingmainlytothedevelopmentsoftechnologyinnanostructurephysics,manystudieshavefocusedonthenanometer-scalemagneticsystemswhichexhibitmacroscop…     

Prediction of grain structure in direct-chill cast Al–Zn–Mg–Cu billets using cellular automaton-finite element method

A cellular automaton-finite element(CA-FE) model was used to predict the solidification grain structure of permanent mold cast A7086 alloy. In this model, a Gaussian distribution of nucleation sites was adopted, and the Kurz-Giovanola-Trivedi model was extended to a multicomponent Al–Zn–Mg–Cu alloy system to determine the growth kinetics of the dendrite tip. For describing the Gaussian distribution of nucleation sites on the mold surface, an empirical relationship between the initial cooling rat...     

缪子：通往新物理的门户

2021年4月7日,美国费米实验室缪子反常磁矩(Muon g-2)国际合作组发布了最新的实验测量结果。结合美国布鲁克海文实验室15年前的实验值,目前缪子反常磁矩最新的实验平均值与标准模型预言值有4.2个标准方差的差异,强烈暗示超越标准模型物理的存在。文章通过介绍基本粒子磁矩的研究历史,希望帮助读者加深对缪子反常磁矩和高精度前沿相关研究的了解和认识。     

Dynamical theory of spectroscopy with pulse excitation

In the coupling system, the dynamical theory of Raman spectroscopy with pulse excitation was developed, and applied to the continuum Raman of IBr. The structure of Raman excitation profile of IBr was explained, which does not follow the new reflection principle.