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Bayesian methods have been well-studied in single-tiered stochastic frontier literature, but as of yet have not been proposed in a two-tiered stochastic frontier (2TSF) setting. Recently, 2TSF models have drawn much attention, observed by increased theoretical extensions and empirical applications. This paper fills the gap in the literature by presenting a Bayesian approach to estimating 2TSF models, with and without independence, as well as with and without efficiency (or bargaining power) determinants. Posterior distributions for the parameters and efficiencies for two bargaining parties are derived. To test our methods, we use both maximum likelihood estimation and Bayesian methods to analyze bargaining power in Major League Baseball salary arbitration negotiations. We find that players who generate their value by hitting for power have more bargaining power, while players who generate their value by having high on-base abilities have less bargaining power. This result is consistent with pre-Moneyball free agent market valuations for these skills. [ABSTRACT FROM AUTHOR]

Tiller number greatly contributes to grain yield in wheat. Using ethylmethanesulfonate mutagenesis, we previously discovered the oligo-tillering mutant ot1. The tiller number was significantly lower in ot1 than in the corresponding wild type from the early tillering stage until the heading stage. Compared to the wild type, the thousand-grain weight and grain length were increased by 15.41% and 31.44%, respectively, whereas the plant height and spike length were decreased by 26.13% and 37.25%, respectively. Transcriptomic analysis was conducted at the regreening and jointing stages to identify differential expressed genes (DEGs). Functional enrichment analysis with the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) databases showed differential expression of genes associated with ADP binding, transmembrane transport, and transcriptional regulation during tiller development. Differences in tiller number in ot1 led to the upregulation of genes in the strigolactone (SL) and abscisic acid (ABA) pathways. Specifically, the SL biosynthesis genes DWARF (D27), D17, D10, and MORE AXILLARY GROWTH 1 (MAX1) were upregulated by 3.37- to 8.23-fold; the SL signal transduction genes D14 and D53 were upregulated by 1.81- and 1.32-fold, respectively; the ABA biosynthesis genes 9-CIS-EPOXICAROTENOID DIOXIGENASE 3 (NCED3) and NCED5 were upregulated by 1.66- and 3.4-fold, respectively; and SNF1-REGULATED PROTEIN KINASE2 (SnRK2) and PROTEIN PHOSPHATASE 2C (PP2C) genes were upregulated by 1.30- to 4.79-fold. This suggested that the tiller number reduction in ot1 was due to alterations in plant hormone pathways. Genes known to promote tillering growth were upregulated, whereas those known to inhibit tillering growth were downregulated. For example, PIN-FORMED 9 (PIN9), which promotes tiller development, was upregulated by 8.23-fold in ot1; Ideal Plant Architecture 1 (IPA1), which inhibits tiller development, was downregulated by 1.74-fold. There were no significant differences in the expression levels of TILLER NUMBER 1 (TN1) or TEOSINTE BRANCHED 1 (TB1), indicating that the tiller reduction in ot1 was not controlled by known genes. Our findings provide valuable data for subsequent research into the genetic bases and regulatory mechanisms of wheat tillering. [ABSTRACT FROM AUTHOR]

Si-based optical position-sensitive detectors (PSDs) have stimulated the interest of researchers due to their wide range of practical applications. However, due to the rigidity and fragility of Si crystals, the applications of flexible PSDs have been limited. Therefore, we presented a flexible broadband PSD based on a WS2/Si heterostructure for the first time. A scalable sputtering method was used to deposit WS2 thin films onto the etched ultrathin crystalline Si surface. The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450–1350 nm, with a high position sensitivity of ∼539.8 mV·mm−1 and a fast response of 2.3 µs, thanks to the strong light absorption, the built-in electrical field at the WS2/Si interface, and facilitated transport. Furthermore, mechanical-bending tests revealed that after 200 mechanical-bending cycles, the WS2/Si PSDs have excellent mechanical flexibility, stability, and durability, demonstrating the great potential in wearable PSDs with competitive performance. [ABSTRACT FROM AUTHOR]

The corrected ordinary least squares (COLS) estimator of the stochastic frontier model exploits the higher order moments of the OLS residuals to estimate the parameters of the composed error. However, both "Type I" and "Type II" failures in COLS can result from finite sample bias that arises in the estimation of these higher order moments, especially in small samples. We propose a novel modification to COLS by using the first moment of the absolute value of the composite error term in place of the third moment for both the Normal-Half Normal and Normal-Exponential specifications. We demonstrate via simulations that this switch considerably reduces the occurrence of both Type I and Type II failures. These Monte Carlo simulations also reveal that our alternative COLS approach, in general, performs better than standard COLS. [ABSTRACT FROM AUTHOR]

Key message: A minor-effect QTL, Qhd.2AS, that affects heading date in wheat was mapped to a genomic interval of 1.70-Mb on 2AS, and gene analysis indicated thatthe C2H2-type zinc finger proteingene TraesCS2A02G181200is the best candidate for Qhd.2AS. Heading date (HD) is a complex quantitative trait that determines the regional adaptability of cereal crops, and identifying the underlying genetic elements with minor effects on HD is important for improving wheat production in diverse environments. In this study, a minor QTL for HD that we named Qhd.2AS was detected on the short arm of chromosome 2A by Bulked Segregant Analysis and validated in a recombinant inbred population. Using a segregating population of 4894 individuals, Qhd.2AS was further delimited to an interval of 0.41 cM, corresponding to a genomic region spanning 1.70 Mb (from 138.87 to 140.57 Mb) that contains 16 high-confidence genes based on IWGSC RefSeq v1.0. Analyses of sequence variations and gene transcription indicated that TraesCS2A02G181200, which encodes a C2H2-type zinc finger protein, is the best candidate gene for Qhd.2AS that influences HD. Screening a TILLING mutant library identified two mutants with premature stop codons in TraesCS2A02G181200, both of which exhibited a delay in HD of 2–4 days. Additionally, variations in its putative regulatory sites were widely present in natural accession, and we also identified the allele which was positively selected during wheat breeding. Epistatic analyses indicated that Qhd.2AS-mediated HD variation is independent of VRN-B1 and environmental factors. Phenotypic investigation of homozygous recombinant inbred lines (RILs) and F2:3 families showed that Qhd.2AS has no negative effect on yield-related traits. These results provide important cues for refining HD and therefore improving yield in wheat breeding programs and will deepen our understanding of the genetic regulation of HD in cereal plants. [ABSTRACT FROM AUTHOR]

A simple yet easy to implement method is proposed to further improve the finite sample approximation of the recently developed central limit theorems for aggregates of envelopment estimators. Focusing on the simple mean efficiency, we propose using the bias-corrected individual efficiency estimate to improve the variance estimator. The extensive Monte-Carlo experiments confirm that, for relatively small sample sizes (≤100), with both low dimensions and especially for high dimensions, our new method combined with the data sharpening method generally provides better 'coverage' (of the true values by the estimated confidence intervals) than the previously developed approaches. [ABSTRACT FROM AUTHOR]

This paper examines the performance of Chinese commercial banks before, during and after the 2007–2008 global financial crisis and China's 4 trillion renminbi stimulus plan during 2008–2010. Fully nonparametric methods are used to estimate technical efficiencies. Recently-developed statistical results are used to test for changes in efficiencies as well as productivity over time, and to test for changes in technology over time. We also test for differences in efficiency and productivity between big and small banks, and between domestic and foreign banks. We find evidence of non-convexity of banks' production set. Our results suggest that technical efficiency declined at the start of the global financial crisis and again during 2011–2012 after enactment of the stimulus plan. Although efficiency recovered somewhat during 2013–2014, China's banks ended with lower technical efficiency on average in 2014 than in 2007. We find that productivity declined during 2008–2009, increased during 2013–2014, but as with efficiency ended lower on average in 2014 than in 2007. We find compelling evidence that big banks were more efficient than small banks throughout 2007–2014, and in most years also were more productive. Finally, domestic banks were on average more efficient than foreign banks in 2007, but foreign banks were more efficient than domestic banks in 2014. Similarly, foreign banks were on average more productive than domestic banks in 2007, but less productive than domestic banks in 2012–2014. [ABSTRACT FROM AUTHOR]

Evaluating shadow prices is critical in devising environmental regulatory policies for pollutants. Compared to traditional frontier estimation methods, this paper uses a recently developed data-driven approach named convex quantile regression, taking both the noise and inefficiency into account and estimating the shadow prices locally. This paper is the first work applying convex quantile regression to jointly evaluate shadow prices of CO2, SO2, and NOx produced by U.S. coal power plants from 2010 to 2017. During this period, five major regulatory provisions were implemented for U.S. coal power plants. We find that the shadow prices of CO2, SO2, and NOx increased from 2010 to 2017. The increase in the shadow price of CO2 is mainly due to the increase in electricity prices, while the increase in shadow prices of SO2 and NOx is mainly due to the successful emission reductions. Moreover, the results show that the CSARP and CSARP Update have significantly increased the shadow prices of SO2 and NOx. However, the relatively lower market allowance prices compared to the shadow prices indicate that society could benefit more if the government could increase the market prices of the pollutants to be more close to the shadow prices. [ABSTRACT FROM AUTHOR]

This paper estimates the shadow price of equity for U.S. commercial banks over 2001–2018 using nonparametric local-linear estimators of the underlying cost frontier and tests the existence of "Too-Big-to-Fail" (TBTF) banks. Evidence for the existence of TBTF banks is found. We find that a negative correlation exists between the shadow price of equity and the size of banks in each year, suggesting that big banks pay less for equity than small banks. In addition, in each year there are more banks with a negative shadow price of equity in the fourth quartile based on total assets than in the other three quartiles. The data also reveal that for each year, the estimated mean shadow price of equity for the 50 largest banks is smaller than the mean price of deposits, even though equity is commonly viewed as a riskier asset than deposits. Finally, we find that the top 10 largest banks are willing to pay much more at the start of the global financial crisis and after the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 than the other periods. These results imply that these regulations are effective in reducing the implicit subsidy, at least for the top 10 largest banks. However, it is also evident that the recapitalization has imposed significant equity funding costs for the top 10 largest banks. [ABSTRACT FROM AUTHOR]

To identify novel allelic variations in key genes of wheat quality, the present study used the targeting induced local lesions in genomes platform to detect point mutations in target genes. The wheat variety Longfumai 17 was treated by the mutagen ethyl methanesulfonate to produce a bulk M generation, and the population included 1122 plants. A total length of 3906.80 kb nucleotides was analyzed, and the average mutation density was 1/244.17 kb. The identified mutations included G>A substitutions (43.75%), C>T substitutions (31.25%), A insertions (12.50%), T insertions (6.25%), and deletions (6.25%). These point mutations led to changes in amino acids and thus the encoded protein sequences, ultimately producing 18.75% of missense mutations, 12.50% of frame shift mutations, 6.25% of nonsense mutations, 25.00% of silent mutations and 37.50% of non-coding region mutations. In the kernel hardness gene Pinb and 3 starch synthesis genes waxy, Agp2 and SSIIa-A, we detected 16 different point mutations in 25 mutant lines. The Pinb gene harbored two missense mutations and a nonsense mutation; the C>T missense mutation resulted in a novel allele, this novel allele and the nonsense mutation alerted protein 3D structure; the waxy gene presented missense and frame shift mutations; the Agp2 gene carried a missense mutation; the SSIIa-A incurred a missense mutation and a frame shift mutation that resulted in premature protein termination. All the frame shift mutations, nonsense mutations and the Pinb novel allele resulted in allelic variation of their corresponding genes, which in turn affected their gene functions. The identified mutant lines can be used as intermediate materials in wheat quality improvement schemes. [ABSTRACT FROM AUTHOR]

We report on the temperature-dependent contact resistivity and high-temperature stability of the annealed Ni/Au ohmic contacts to p-type GaN in air. As the measure temperature increases from 25°C to 390°C, both the specific contact resistivity ( ρ) and sheet resistance ( R) decrease by factors ∼10, contributing to the 10-fold increase in current at 390°C compared with that at 25°C. It was also observed that the ρ was further reduced by 36%, i.e., from 2.2 × 10 Ω cm to 1.4 × 10 Ω cm, during the 48-h high-temperature stability test at 450°C in air, showing excellent stability of the contacts. An increase in ρ was observed after the contacts were subjected to 500°C in air. Higher temperature stress led to a significant increase in ρ. The contacts show rectifying I-V characteristics after being subjected to 700°C for 1 h. The degradation mechanics were analyzed with the assistance of transmission electron microscopy and energy dispersive x-ray spectroscopy. [ABSTRACT FROM AUTHOR]