Increased subaerial volcanism and the rise of atmospheric oxygen 2.5 billion years ago

The hypothesis that the establishment of a permanently oxygenated atmosphere at the Archaean-Proterozoic transition (approximately 2.5 billion years ago) occurred when oxygen-producing cyanobacteria evolved is contradicted by biomarker evidence for their presence in rocks 200 million years older. To sustain vanishingly low oxygen levels despite near-modern rates of oxygen production from approximately 2.7-2.5 billion years ago thus requires that oxygen sinks must have been much larger than they are now. Here we propose that the rise of atmospheric oxygen occurred because the predominant sink for oxygen in the Archaean era-enhanced submarine volcanism-was abruptly and permanently diminished during the Archaean-Proterozoic transition. Observations are consistent with the corollary that subaerial volcanism only became widespread after a major tectonic episode of continental stabilization at the beginning of the Proterozoic. Submarine volcanoes are more reducing than subaerial volcanoes, so a shift from predominantly submarine to a mix of subaerial and submarine volcanism more similar to that observed today would have reduced the overall sink for oxygen and led to the rise of atmospheric oxygen.     

A molecular information ratchet

Motor proteins and other biological machines are highly efficient at converting energy into directed motion and driving chemical systems away from thermodynamic equilibrium. But even though these biological structures have inspired the design of many molecules that mimic aspects of their behaviour, artificial nanomachine systems operate almost exclusively by moving towards thermodynamic equilibrium, not away from it. Here we show that information about the location of a macrocycle in a rotaxane-a molecular ring threaded onto a molecular axle-can be used, on the input of light energy, to alter the kinetics of the shuttling of the macrocycle between two compartments on the axle. For an ensemble of such molecular machines, the macrocycle distribution is directionally driven away from its equilibrium value without ever changing the relative binding affinities of the ring for the different parts of the axle. The selective transport of particles between two compartments by brownian motion in this way bears similarities to the hypothetical task performed without an energy input by a 'demon' in Maxwell's famous thought experiment. Our observations demonstrate that synthetic molecular machines can operate by an information ratchet mechanism, in which knowledge of a particle's position is used to control its transport away from equilibrium.     

Recent advances in brown adipose tissue biology

In mammals, white adipose tissue （WAT） store energy, whereas brown adipose tissue （BAT） burns energy. As a thermogenic organ, BAT can help maintain body temperature during cold exposure. Owing to its important roles in energy metabolism and regulating triacylglycerol levels, BAT has received great attention in treating obesity and its related diseases. Recent studies have suggested that BAT may secrete factor（s）—batokines—to regulate whole- body energy metabolism. In this review, we summarize the recent advances in the formation and function of BAT, as well as molecules that regulate the activity of BAT and beige fat.     

Dilute (d) coat colour mutation of DBA/2J mice is associated with the site of integration of an ecotropic MuLV genome

The single endogenous DBA/2J ectropic provirus segregated concordantly with the dilute (d) coat colour mutation on chromosome 9 in 53/53 DBA/2J-derived recombinant inbred mouse strains and all seven inbred and mutant strains tested that carry the d allele. Analysis of DNA from a spontaneous DBA/2J d revertant (d+2J) showed that these mice lack ecotropic-specific MuLV DNA sequences and suggested that the dilute mutation resulted from integration of an ecotropic provirus into the mouse genome.     

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.     

Restructuring performance prediction with a rebalanced and clustered support vector machine

This paper discusses whether asset restructuring can improve firm performance over decades. Variation in the stock price or the financial ratio is used as the dependent variable of either short‐ or long‐term effectiveness to evaluate the variance both before and after asset restructuring. The result is varied. It is necessary to develop a foresight approach for the mixed situation. This work pioneers to forecast effectiveness of asset restructuring with a rebalanced and clustered support vector machine (RCS). The profitability variation 1 year before and after asset restructuring is used as the dependent variable. The current financial indicators of the year of asset restructuring are used as independent variables. Specially treated listed companies are used as research samples, as they frequently adopt asset restructuring. In modeling, the skew distribution of samples achieving and failing to achieve performance improvement with asset restructuring is handled with rebalancing. The similar experienced knowledge of asset restructuring to the current asset restructuring is filtered out with clustering. With the help from rebalancing and clustering, a support vector machine is constructed for prediction, together with other forecasting models of multivariate discriminant analysis, logistic regression, probit regression, and case‐based reasoning. These models' standalone modes are used as benchmarks. The empirical results demonstrate the applicability of the RCS for forecasting effectiveness of asset restructuring.     

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.     

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。