80,305 research outputs found
The Benefits of Being Economics Professor A (and not Z)
Full text linkAlphabetic name ordering on multi-authored academic papers, which is the convention in the economics discipline and various other disciplines, is to the advantage of people whose last name initials are placed early in the alphabet. As it turns out, Professor A, who has been a first author more often than Professor Z, will have published more articles and experienced afaster growth rate over the course of her career as a result of reputation and visibility. Moreover, authors know that name ordering matters and indeed take ordering seriously: Several characteristics of an author group composition determine the decision to deviate from the default alphabetic name order to a significant extent.performance measurement, incentives, economists, name ordering
Service Offshoring and Productivity: Evidence from the United States
Full text linkThe practice of sourcing service inputs from overseas suppliers has been growing in response to new technologies that have made it possible to trade in some business and computing services that were previously considered non-tradable. This paper estimates the effects of offshoring on productivity in US manufacturing industries between 1992 and 2000. It finds that service offshoring has a significant positive effect on productivity in the US, accounting for around 10 percent of labor productivity growth during this period. Offshoring material inputs also has a positive effect on productivity, but the magnitude is smaller accounting for approximately 5 percent of productivity growth.
Swarm behavioral sorting based on robotic hardware variation
No full textSwarm robotic systems can offer advantages of robustness, flexibility and scalability, just like social insects. One of the issues that researchers are facing is the hardware variation when implementing real robotic swarms. Identical software cannot guarantee identical behaviors among all robots due to hardware differences between swarm members. We propose a novel approach for sorting swarm robots according to their hardware differences. This method is based on the large number of interactions between robots and the environment. Individual robot’s unique hardware circumstance determines its unique decision and reaction during each robotic controlling step, and these unique local reactions accumulate and contribute to the robot’s global behavior. Accordingly by separating these hardware-triggered global behaviors, swarm robots can be sorted according to their hardware variations
Optimal production of poly-gamma-glutamic acid by metabolically engineered Escherichia coli
No full textMetabolically-engineered Escherichia coli strains were developed by cloning poly-gamma-glutamic acid (gamma-PGA) biosynthesis genes, consisting of pgsB, pgsC and pgsA, from Bacillus subtilis The metabolic and regulatory pathways of gamma-PGA biosynthesis in E. coli were analyzed by DNA microarray. The inducible trc promoter and a constitutive promoter (P-HCE) derived from the D-amino acid aminotransferase (D-AAT) gene of Geobacillus toebii were employed. The constitutive HCE promoter was more efficient than inducible trc promoter for the expression of gamma-PGA biosynthesis genes. DNA microarray analysis showed that the expression levels of several NtrC family genes, glnA, glnK, glnG, yhdX, yhdY, yhdZ, amtB, nac, argT and cbl were up-regulated and sucA, B, C, D genes were down-regulated. When (NH4)(2)SO4 was added at 40 g/l into the feeding solution, the final gamma-PGA concentration reached 3.7 g/l in the fed-batch culture of recombinant E. coli/pCOpgs.This work was supported by the
Basic Industrial Technology Development Project of the
Korea Ministry of Commerce, Industry and Energy,
National Research Laboratory Program of the Korea
Ministry of Science and Technology, Center for Ultramicrochemical
Process Systems, and by the BK21 project of
Korea
Final word on Jersey Dutch
No full textIn this article, William Z. Shetter compares and contrasts the dialects that developed between different Dutch colonies in the New World. He explores in-depth the nuances of Jersey Dutch, and provides theories to explain how Dutch and colonial languages blended. The article is reprinted from American Speech, December 1958, Volum XXXIII, No. 4
Zinc Ion Released from Xenopus Transcription Factor IIIA Induced by Chemical Modification
No full textNonparametric time series forecasting with dynamic updating
Full text linkWe present a nonparametric method to forecast a seasonal univariate time series, and propose four dynamic updating methods to improve point forecast accuracy. Our methods consider a seasonal univariate time series as a functional time series. We propose first to reduce the dimensionality by applying functional principal component analysis to the historical observations, and then to use univariate time series forecasting and functional principal component regression techniques. When data in the most recent year are partially observed, we improve point forecast accuracy using dynamic updating methods. We also introduce a nonparametric approach to construct prediction intervals of updated forecasts, and compare the empirical coverage probability with an existing parametric method. Our approaches are data-driven and computationally fast, and hence they are feasible to be applied in real time high frequency dynamic updating. The methods are demonstrated using monthly sea surface temperatures from 1950 to 2008.Functional time series, Functional principal component analysis, Ordinary least squares, Penalized least squares, Ridge regression, Sea surface temperatures, Seasonal time series.
Data from: Dianyuea gen. nov. (Salicaceae: Scyphostegioideae) from southwestern China
No full textDianyuea C. Shang, S. Liao & Z. X. Zhang, a new monotypic genus of Salicaceae based on Flacourtia turbinata H. J. Dong & H. Peng, is described and illustrated. Morphologically, Dianyuea differs from Flacourtia Comm. ex L'Hér. by having six connate stamens, basal placentation and lobed seed appendages. All those features indicate that Dianyuea is allied with Scyphostegia Stapf. A molecular phylogenetic analysis using plastid trnL-F, matK, and rbcL sequence data for representatives of 16 genera in Salicaceae s.l. shows that Dianyuea is sister to Scyphostegia. The new combination Dianyuea turbinata (H. J. Dong & H. Peng) C. Shang, S. Liao & Z. X. Zhang is proposed
- …
