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PurposeAlthough social networks play an important role in individual ambidexterity, few studies have examined the impact of salespeople's social networks on sales-service ambidexterity. The purpose of this paper is to explore how salespeople's internal and external social networks affect sales-service ambidexterity.Design/methodology/approachThe unique data of 331 salespeople from 39 units in retail banking industry and insurance industry were collected, and the hierarchical linear model was adopted to test the hypotheses. Finally, the alternative measure of the dependent variable and the alternative estimation method were adopted for robustness test.FindingsThe results show that the strength of salespeople's internal social networks and the extensiveness of salespeople's external social networks could facilitate sales-service ambidexterity of salespeople separately and synergistically. Salespeople's role breadth self-efficacy partially mediates the influences of internal and external social networks on sales-service ambidexterity, while empowerment climate and transformational leadership positively moderate the aforementioned mediational process by strengthening the relationship between salespeople's role breadth self-efficacy and sales-service ambidexterity.Practical implicationsPractical guidelines are provided for managers to shape ambidextrous salespeople by facilitating salespeople's internal and external social networks, promoting transformational leadership and creating empowerment climate within the unit.Originality/valueTo the best of the author's knowledge, this paper is the first to systematically examine the impact of salespeople's social network on sales-service ambidexterity. Drawing from social cognitive theory and the ambidexterity literature, this research reveals the mechanism of how salespeople's internal and external social networks contribute to sales-service ambidexterity.

Background Hereditary coagulation factor XII (FXII) deficiency is an autosomal recessive disorder. At present, the contribution of severe FXII deficiency to the development of thromboembolism is still undetermined. There are limited reports on the relationship between the FXII defect and thromboembolism. Case Presentation A 27-year-old woman came to our hospital for the treatment of shoulder trauma and cervical disc herniation caused by a car accident. The shoulder trauma was treated with five stitches. After physical examination, imaging examination, and routine coagulation examination, cervical disc herniation was treated conservatively. Combined with the examination results, the patient was diagnosed with FXII deficiency. Unfortunately, the patient was readmitted 10 days after the trauma with edema in the lower limbs and secondary varicose veins. The D-dimer increased to 6.22 mg/L. Thrombus in the inferior vena cava and right common iliac was shown by lower limb venography. According to the patient's medical history, the F12 gene was analyzed by direct sequencing. The patient was also screened for other thrombotic risk factors. Genetic analysis showed that the patient had a c.1748T > A (p.Ile583Asn) homozygous missense mutation in exon 14 of the F12 gene. No other hereditary thrombophilia risk factors screened were positive in the patient. Conclusion The p.Ile583Asn missense mutation in exon 14 of the F12 gene might be responsible for the reduction of the FXII level in the patient.

PurposeThis paper aims to examine the relationships between the group affiliates’ dual legitimacy (membership legitimacy and societal legitimacy) and dual resource acquisition (intra-group and out-group), and the moderating roles of environmental uncertainty and munificence in the emerging economies.Design/methodology/approachThis paper adopts hierarchical regression analysis to test the hypotheses based on the unique data of 251 group affiliated firms in China and applies the alternative measurements and alternative methodology of structural equation modeling into robustness check to confirm the results.FindingsThe results show as follows: the group affiliates can benefit from membership legitimacy for intra-group resource acquisition and out-group resource acquisition through the mediations of societal legitimacy and intra-group resource acquisition. However, in the linkage between affiliates’ membership legitimacy and intra-group resource acquisition and the linkage between societal legitimacy and out-group resource acquisition, environmental uncertainty plays the positive moderating roles while environmental munificence plays the negative moderating roles. Under the condition of high environmental uncertainty and low environmental munificence, the linkage between membership legitimacy and intra-group resource acquisition, and the linkage between societal legitimacy and out-group resource acquisition reach the strongest level.Research limitations/implicationsThe findings highlight the importance of dual legitimacy building for group affiliates to acquire resources both inside and outside the business group when they operate in emerging economies characterized by high environmental uncertainty and low environmental munificence. However, it does not explore the contextual factors (e.g. institutional distance) affecting the relationship between the affiliate’s membership legitimacy and societal legitimacy. Then more group-level factors are expected to be included and explored with multi-level models in the future studies.Originality/valueThe findings reveal the mechanism of how group affiliates benefiting differently from dual legitimacy to acquire resources in the emerging economies, which also provide a new interpretation for the questions of who benefiting more from the group affiliation, how and why (Carney et al., 2009). This research also explores the moderating roles of task environmental characteristics (environmental uncertainty and environmental munificence) on the affiliate's dual legitimacy and dual resource acquisition, which helps understand why legitimacy building is more important in terms of resource acquisition in the emerging economy characterized by uncertainty and non-munificence.

This paper proposes a nonparametric approach for estimation of stochastic production functions with categorical and continuous variables, and then develops procedures that allow for inference on production risk. The estimation is based on the kernel method and the inference is based on a bootstrapping approach. We establish the asymptotic properties of our proposed estimator. Monte Carlo simulation results suggest that our proposed nonparametric procedure is more robust and outperforms other existing parametric and nonparametric methods. In addition, we empirically illustrate the proposed nonparametric approach using long‐run corn production data from university field trials in Wisconsin that examines the performance of genetically modified corn varieties. Specifically, the proposed nonparametric procedure is used to empirically examine the production risk effects of categorical genetically modified variety variables and a continuous planting density variable.

There have been a number of previous studies that examined the effects of yield‐ or revenue‐based crop insurance products on input use of farmers. However, no study has specifically investigated the input use impacts of a cost‐of‐production (COP) crop insurance policy, even though this type of crop insurance is the predominant one used in several other countries outside of the United States (such as the Philippines and China). This article aims to theoretically and empirically examine the effect of a COP crop insurance product on farmers’ chemical input use. Our theoretical model suggests that the effect of COP insurance on input use can either be positive or negative, with the resulting impact depending on the strengths of (a) the traditional moral hazard effect of insurance (i.e., an input use decreasing effect); versus (b) the marginal incentives to apply more inputs due to input levels being the main determinant for expected indemnity amounts in this type of insurance (i.e., an input use increasing effect). A survey data set from corn farmers in the Philippines is then used to empirically illustrate how a particular COP insurance product influences input use in a real‐life context. In this case, we find that COP insurance increases the use of chemical inputs (e.g., fertilizers and total chemical expenditure), implying that the positive marginal incentive to apply more inputs dominates the negative moral hazard effect.

Background Tumor progression and distant metastasis are the main causes of deaths in colorectal cancer (CRC) patients, and the molecular mechanisms in CRC metastasis have not been completely discovered. Methods We identified differentially expressed genes (DEGs) and lncRNAs (DELs) of CRC from The Cancer Genome Atlas (TCGA) database. Then we conducted the weighted gene co-expression network analysis (WGCNA) to investigate co-expression modules related with CRC metastasis. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, DEG-DEL co-expression network and survival analyses of significant modules were also conducted. Finally, the expressions of selected biomarkers were validated in cell lines by quantitative real-time PCR (qRT-PCR). Results 2032 DEGs and 487 DELs were involved the construction of WGCNA network, and greenyellow, turquoise and brown module were identified to have more significant correlation with CRC metastasis. GO and KEGG pathway analysis of these three modules have proven that the functions of DEGs were closely involved in many important processes in cancer pathogenesis. Through the DEG-DEL co-expression network, 12 DEGs and 2 DELs were considered as hub nodes. Besides, survival analysis showed that 30 DEGs were associated with the overall survival of CRC. Then 10 candidate biomarkers were chosen for validation and the expression of CA2, CHP2, SULT1B1, MOGAT2 and C1orf115 were significantly decreased in CRC cell lines when compared to normal human colonic epithelial cells, which were consistent with the results of differential expression analysis. Especially, low expression of SULT1B1, MOGAT2 and C1orf115 were closely correlated with poorer survival of CRC. Conclusion This study identified 5 genes as new biomarkers affecting the metastasis of CRC. Besides, SULT1B1, MOGAT2 and C1orf115 might be implicated in the prognosis of CRC patients.

This paper uses truncated count model with endogeneity and simulated maximum likelihood estimation technique to estimate gender differences in moral hazard in health care insurance. We use the dataset that consists of invoices for all outpatient services from a regional hospital in Croatia. Our theoretical model predicts that higher risk aversion is associated with smaller ex-post moral hazard effect. If women are more risk averse than men, then the moral hazard effect due to health insurance should be lower in women than in men. After adjusting for the sample selection in the estimation, we found a statistically significant evidence of moral hazard for the general population but statistically insignificant difference in moral hazard between men and women.

We investigate contract elements and growing conditions associated with anomalous claims behaviour in the U.S. Federal Crop Insurance Program. In this study the measure of “anomalous claims behaviour” is based on the number of producers (in a county) placed on the “Spot Check List” (SCL)—a list generated from government compliance efforts that aim to detect and deter fraud, waste, and abuse in the U.S. Federal Crop Insurance Program. Using county-level data and various econometric approaches that control for features of this data set (e.g., the count nature of the dependent variable, censoring, potential endogeneity, and spatial/temporal dependence), we find that the following crop insurance contract attributes influence the extent of anomalous claims behaviour in a county: (a) the ability to insure individual fields through “optional units”; (b) the coverage level choice; and (c) the total number of acres insured. In addition, our empirical analyses suggest that anomalous claims behaviour significantly increases when extreme weather events occur (e.g., droughts, floods) and when economic conditions are unfavourable (i.e., high input costs that lower profit levels). Results from this study have important implications for addressing potential underwriting vulnerabilities in crop insurance contracts and the frequency of more rigorous compliance inspections.

Summary shelf nutrition labels are one of a handful of practical strategies that hold the promise of improving nutrition and public health. We use a difference‐in‐differences approach to estimate the effect of the NuVal shelf label—an interpretive numeric score, now defunct, that rated the overall nutrition of foods from one (least healthful) to 100 (most healthful)—on consumer demand for yogurt. The results indicate that NuVal labels affected product sales through an information provision effect that increases with the value of the nutrition score on the product and a publicity (i.e., salience) effect that is unrelated to the level of the score. A one‐point increase in NuVal score on a yogurt product is estimated to increase demand by 0.23%.

We conduct the first econometric analysis of the determinants of the formation of Taobao villages, the rural e-commerce clusters recently appeared in China. We examine the roles of various factors such as location, education, transportation infrastructure, the structure of local economy, urban-rural income difference, local government policies and spillover from nearby Taobao villages in the formation of Taobao villages. We find that education plays an important and positive role in the formation of Taobao villages, while credit support for other businesses makes the formation of new Taobao villages less likely.

This article examines the moral hazard and adverse selection effects of cost‐of‐production (COP) crop insurance products. Building on existing crop insurance models of moral hazard, as well as a survey‐based data set that allows us to separately identify moral hazard from adverse selection, we find evidence that farmers insured under COP contracts spend more on chemical fertilizers and pesticides (i.e. those inputs whose costs determine the indemnity payments). However, since these same COP insured farmers are still likely to use less inputs (like effort) whose costs do not enter the indemnity payment formula, and yield depends on both types of inputs (i.e. the determinants and non‐determinants of the indemnity payments), the final moral hazard effect of COP insurance on yields is ambiguous. Our analysis also suggests that farmers who tend to spend less on chemical fertilizers and pesticides are the ones with private information on soil conditions and pest incidence. These are the types of farmers who adversely select into COP contracts that only cover weather related losses.

Background: For fresh thoracolumbar burst fracture, a new method which can not only promote the fracture healing, but also retain the movement segment, and restore the spinal movement function to the maximum extent is needed. The purpose of this study is to determine the performance of stabilization of a semi-rigid stabilization system combined with transpedicular intracorporeal bone grafting for thoracolumbar burst fractures.Methods Six thoracolumbar cadaver spines were used for testing. A controlled L2 burst fracture was created. The L1-3 motions were determined.Results In extension, flexion and lateral bending, the semi-rigid fixator stabilized the segment to a range of motion(ROM) and neutral zone(NZ) below the magnitude of the intact spine, but showed increased ROM and NZ of axial rotation (P < 0.05) compared with the intact spine.Conclusions Restoration of stability with the semi-rigid dynamic system combined with transpedicular intracorporeal bone grafting is possible in flexion, extension, right and left lateral bending for thoracolumbar burst fracture but for axial rotation.

Waardenburg syndrome (WS) is a genetic disorder characterized by hearing loss and pigmentary abnormalities with variable penetrance. Though heterozygous mutations in MITF are a major cause for Waardenburg syndrome type 2 (WS2), homozygous mutations in this gene and the associated phenotype have been rarely characterized. In this study, we identified a novel p.R223H mutation in MITF in a Chinese Han family with variable WS features. Both parents carried a heterozygous p.R223H mutation. They had normal hearing, and premature greying of the hair is their only pigmentary abnormality. In contrast, their two children both carried a homozygous p.R223H mutation and had classic WS features including profound hearing loss, heterochromia irides and marked pigmentary abnormalities in hair and skin. Interestingly, the two affected children also have persistent chronic constipation since the neonatal period, symptoms suggestive of Waardenburg syndrome type 4 (WS4). Our study revealed a likely association between homozygous mutations in MITF and WS4, which implies a dosage effect for the underlying pathogenesis mechanism.

Using household survey data from three Agro‐Taobao villages, which are clusters of e‐commerce agribusinesses recently appeared in China, and three nearby non‐Agro‐Taobao villages, we examine whether originating from an Agro‐Taobao village influences a farmer’s migration decision. Results show that individuals from Agro‐Taobao villages are 26% less likely to migrate than their counterparts from non‐Agro‐Taobao villages, after controlling for various factors that are likely to influence the migration decision such as demographic characteristics, migration experience, educational background, and health status. Policy implications of our findings are also discussed. [EconLit citations: Q13; Q12]

We extend the recently proposed multi‐dimensional asymmetric information model to show that advantageous selection could be present in crop insurance with two types of coverage: (i) multiple perils (e.g. a multi‐peril, ‘all risk’ policy), and (ii) a specific named peril (or set of perils). Our theoretical model suggests that certain characteristics of an insured farmer (or farm) under both types of coverage can be sources of advantageous selection. Farmers who advantageously select are more likely to purchase insurance coverage and less likely to realise a loss. A supplementary empirical analysis, based on data from the Philippine crop insurance market, illustrates how sources of advantageous selection can be identified econometrically.

Background Reactive oxygen species modulator 1 (ROMO1) is recognized to be involved in cell proliferation and is elevated in serum of various cancer patients. However, ROMO1 had little research in distinguishing between malignant pleural effusions (MPEs) and benign pleural effusions (BPEs). Methods Malignant pleural effusion samples from patients with non–small‐cell lung cancer (NSCLC) and benign pleural effusion (BPE) samples containing tuberculous and inflammatory pleural effusions were collected. The samples were tested for ROMO1, pleural effusion adenosine deaminase (pADA), pleural effusion carbohydrate antigen (pCA125, pCA153, pCA199), pleural effusion ferritin (pFER), and pleural effusion lactate dehydrogenase (pLDH) levels, and the other relevant partial clinical data that were gathered were used to conduct statistical analysis. Results The ROMO1, pCA125, pCA199, pCA153, pADA + ROMO1, pCA153 + ROMO1, pCA125 + ROMO1, and pCA199 + ROMO1 levels in MPE were appreciably higher in comparison with BPE group (all P = .000). The concentration of pADA in MPE was markedly lower than BPE (P = .000). When the cutoff = 0.38, the sensitivity of combined detection of ROMO1 + pADA is 98.67% and the specificity is 70.73%, respectively, and the AUC (0.941) is the highest among other parameters. Conclusion The combined detection of ROMO1 + ADA in pleural effusion is an effective biomarker for identifying MPE caused by NSCLC.

Objective: To compare and analyze the clinical effects of internal fixation of minimally invasive elastic stable intramedullary nail and plate in the treatment of pediatric femoral shaft fracture. Methods: A total of 120 children with femoral shaft fractures who were admitted to our hospital from December 2016 to April 2018 were enrolled. The children were divided into an observation group and a control group by random number table, with 60 children in each group. The children in the observation group underwent internal fixation of minimally invasive elastic stable intramedullary nail, while those in the control group underwent open reduction based on internal fixation of plate. The surgical status and postoperative complications of the two groups were observed and compared, and Kolmert knee function scoring criteria were used for assessing the surgical effects of children. Results: The operation duration, intraoperative blood loss, hospitalization duration, fracture healing time and time of off-bed loaded activity of the observation group were significantly shorter than those of the control group, and the differences were statistically significant (P0.05). Conclusion: Pediatric femoral shaft fractures can be treated with internal fixation of minimally invasive elastic intramedullary nail, and it has advantages of significant curative effect, small trauma and fast postoperative recovery, which is conducive to fracture healing and worth promoting.

Objective: To compare and analyze the clinical effects of internal fixation of minimally invasive elastic stable intramedullary nail and plate in the treatment of pediatric femoral shaft fracture. Methods: A total of 120 children with femoral shaft fractures who were admitted to our hospital from December 2016 to April 2018 were enrolled. The children were divided into an observation group and a control group by random number table, with 60 children in each group. The children in the observation group underwent internal fixation of minimally invasive elastic stable intramedullary nail, while those in the control group underwent open reduction based on internal fixation of plate. The surgical status and postoperative complications of the two groups were observed and compared, and Kolmert knee function scoring criteria were used for assessing the surgical effects of children. Results: The operation duration, intraoperative blood loss, hospitalization duration, fracture healing time and time of off-bed loaded activity of the observation group were significantly shorter than those of the control group, and the differences were statistically significant (P0.05). Conclusion: Pediatric femoral shaft fractures can be treated with internal fixation of minimally invasive elastic intramedullary nail, and it has advantages of significant curative effect, small trauma and fast postoperative recovery, which is conducive to fracture healing and worth promoting. doi: https://doi.org/10.12669/pjms.35.5.513 How to cite this:Wang W, Zheng X, Sun Z. Comparison of efficacy between internal fixation of minimally invasive elastic stable intramedullary nail and plate in the treatment of pediatric femoral shaft fracture. Pak J Med Sci. 2019;35(5):1417-1421. doi: https://doi.org/10.12669/pjms.35.5.513 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

In the US-China international flight market, airlines sell tickets in two different distribution channels at vastly different prices. This provides a rare opportunity to examine how airlines practice price discrimination across different ticket distribution channels. Using a unique dataset collected from this market, we find that price discrimination across different ticket distribution channels is not influenced by market competition but increases with demand.

Gelsemine from Gelsemium elegans Benth is a potential anesthetic and analgesic agent with no physical dependence and opiate addiction. This study was aimed at developing an ultrafast liquid chromatography coupled to tandem mass spectrometry method to quantify gelsemine in rat plasma and tissues. Plasma and tissues were processed with acetonitrile precipitation, and dendrobine was chosen as the internal standard. Sample separation was performed on an ACQUITY HSS T3 column. The mobile phase consisted of acetonitrile and 0.1% formic acid aqueous solution. Multiple reactions monitoring mode was utilized to detect the compounds of interest. The mass spectrometer was operated in the positive ion mode for detection. The MS/MS ion transitions monitored were m/z 323.2→70.5 for gelsemine and 264.2→108.05 for dendrobine, respectively. The calibration curves were linear over the range of 1-500 ng/mL in all biological matrices. The lower limit of quantification for rats plasma and tissues was 1.0 ng/mL. The values for inter- and intraday precision and accuracy were well within the ranges acceptable (< 15%). It was successfully applied to the pharmacokinetic and tissue distribution studies of gelsemine after intravenous doses of 5, 2, and 0.5 mg/kg in rats. These data of gelsemine would be useful for clinical application and further development.

We study the productivity-survival link in the U.S. poultry processing industry using longitudinal data constructed from 5 censuses of manufactures between 1987 and 2007. First, we study the effects of physical productivity and demand-specific factors on plant survival and ownership change. Second, we analyze the determinants of the firm-level expansion. The results show that higher demand-specific factors decrease the probability of exit and increase the probability of ownership change. The effect of physical productivity on the probability of exit or ownership change is generally insignificant. Also, firms with higher demand-specific factors have higher probability to expand, whereas average firm-level physical productivity turns out to be an insignificant determinant of firm expansion. Since demand specific factors all favor large companies, this could expedite industry concentration process already well under way and could raise new concerns over contract growers' income and consumers' welfare.

The cooperative material basis of the multi-component and multi-target mechanism of action of Traditional Chinese Medicine (TCM) is difficult to elucidate because of the current lack of appropriate techniques and strategies. In this paper, we focus on rhubarb treatment of renal fibrosis. Molecular docking, metabolic pathway enrichment, and network pharmacology methods were used to theoretically determine the interaction between the components of the rhubarb and disease targets related to renal fibrosis. Moreover, the methods of metabolomics, serum pharmacochemistry, histopathology and immunohistochemistry were used for the model group, the sham-operated group and the rhubarb administration group to reveal the active components and mechanisms of rhubarb. Finally, the experimental and theoretical results were integrated and comprehensively analyzed. Results indicated that anthraquinones and flavanols, such as rhein, emodin, catechin, and epicatechin, were the main active components of rhubarb. These active components play synergistic therapeutic efficacies through regulating the abnormal accumulation of the extracellular matrix, controlling the release of inflammatory factors and maintaining the balance of coagulation and fibrinolysis. Our study showed that the integration of metabolomics and network pharmacology is a powerful strategy for discovering active components of TCMs and for elucidating their mechanisms.

Jujuboside B (JuB) is a main bioactive saponin constituent of Ziziphi Spinosae Semen. The compound is used clinically as an anti-insomnia and anti-anxiety medicine. In this study, a sensitive, simple, and rapid ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) was developed and validated to quantify JuB in rat plasma. A simple protein-precipitation method was used to extract JuB from rat plasma samples. Jujuboside A was used as an internal standard (IS). Chromatographic separation was performed using an Acquity HSS T3 column. The mobile phase consisted of acetonitrile and 0.1% formic acid in water with a flow rate of 0.3 mL min−1. Identification and quantification were performed through electrospray ionization in a negative mode with multiple reaction monitoring of JuB and IS transitions of m/z 1043.3 → 911.5 and m/z 1205.6 → 1073.4, respectively. The calibration curve was linear in the range of 0.1 ng mL−1 to 1000 ng mL−1 (R2 = 0.990) with a limit of detection of 0.03 ng mL−1. The extraction recoveries of JuB were 90.3% to 95.7% and the precisions of intra-and inter-day were less than 11.5%. The matrix effect of JuB at three different concentrations ranged from 93.5% to 95.9% with a standard deviation of

Purpose – The purpose of this paper is to quantify the benefits to farmers from using alternative marketing arrangements (AMAs) in the USA. The authors first estimate a behavioral model explaining farmers' joint decisions on which commodities to produce and which marketing channels to use when selling their outputs. The authors then use the estimated model to quantify the benefits to farmers from using AMAs. Design/methodology/approach – The authors use the discrete choice random utility maximization model to examine farmers' choices on production regimes, where a regime is defined as a possible combination of all the individual commodity/marketing arrangement channels that the farmer can choose to use. The farmer is assumed to compare the utilities he gets from each of the possible production regimes and then selects the production regime that yields the highest utility to him. The benefit of having access to a particular AMA is measured as the negative of the welfare loss associated with forcing the farmer to abandon that particular AMA. Findings – The results indicate that AMAs yield an economically significant amount of benefits to farmers who rely on them to market their outputs. At the national level, the benefit of using production contracts to hog farmers is valued at $336.4 million. The benefits of using marketing contracts are valued at $374.2, $156.6 and $92.1 million for corn, soybeans and wheat producers. Originality/value – The paper is the first study that uses the farm-level data to study the welfare effects of marketing contracts in the grain sector. The results show that considering a multi-enterprises farm, farmers' welfare loss might be smaller when the hog production contract is no longer existed.

1. This study was aimed at developing a high sensitive and selective liquid chromatography-tandem mass spectrometry method to quantify neohesperidin dihydrochalcone (NHDC) in rat plasma and tissues for pharmacokinetic, bioavailability and tissue distribution studies. 2. Biological samples were processed with one-step protein precipitation. Rutin was chosen as the internal standard (IS). Chromatographical separation was achieved on an SB-C18 (2.1 mm× 150 mm, 5 μm) column with acetonitrile--0.1% formic acid in water as the mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in negative ion mode; selected ion monitoring mode was used for quantification using target fragment ions m/z 611.4 for NHDC and m/z 609.1 for IS. 3. Calibration plots were linear over the range of 10-3000 ng/mL for NHDC. Lower limit of quantification (LLOQ) for NHDC was 10 ng/mL. Mean recovery of NHDC from plasma and tissues was better than 80.3%. Coefficient of variation of intra-day and inter-day precision were both less than 15%. The bioavailability of NHDC was 21.8%. 4. In conclusion, a sensitive, simple and specific LC-ESI-MS method for the determination of NHDC in rat biological samples was developed. This developed method is successfully used in the pharmacokinetic and tissue distribution study of NHDC in rats.

Alumina microfibers with porous structures were prepared through hydrothermal reaction, and then used to modify the surface of carbon paste electrode (CPE). After modification with alumina microfibers, the electrochemical activity of CPE was found to be greatly improved. On the surface of alumina microfibers-modified CPE, the oxidation peak current of salvianolic acid B, a main bioactive compound in Danshen with anti-oxidative and anti-inflammatory effects, was remarkably increased compared with that on the bare CPE surface. The influences of pH value, amount of alumina microfibers and accumulation time were studied. Based on the strong signal amplification effects of alumina microfibers, a novel electrochemical method was developed for the detection of salvianolic acid B. The linear range was from 5 to 0.3 mg , and the detection limit was 2 (2.78 nM) after 1-min accumulation. The new method was successfully used to detect salvianolic acid B in ShuangDan oral liquid samples, and the recovery was over the range from 97.4% to 102.9%.

We focus on the relationship between a player's effort provision and tournament heterogeneity in a setting where players only know the distribution of their opponents' abilities. By isolating whether increases in heterogeneity influence optimal effort provision in cardinal, ordinal, and piece rate tournaments, we show that a model in which ability and effort are complements can be empirically distinguished from a model in which ability and effort are neither complements nor substitutes. To discriminate between the two models, we conduct a laboratory experiment where subjects participate in a real effort task and are paid based on performance relative to a group of opponents that may be relatively homogeneous or relatively heterogeneous. In these laboratory data, the level of effort provision is independent of tournament heterogeneity, lending support to the model in which ability and effort are neither complements nor substitutes.

Using household scanner data and a discrete choice modeling approach, we estimate demand for milk products at the micro-level and compute the distribution of welfare effects from introducing organic milk across households with different characteristics within the partial equilibrium framework. The price effects of introducing organic milk are larger for low-income households than for high-income households, and the differences in the variety effects of introducing organic milk to groups with various levels of education are larger than the differences in the variety effects among groups with different income levels. Policy implications of these findings are discussed. Copyright 2013, Oxford University Press.

In this study, we test the relationship between price volatility and contract maturity, or the “Samuelson effect,” using futures contract prices for a major sports event. Applying four different performance measures, we show supportive evidence of the Samuelson effect in futures contracts for tickets to the Super Bowl XLIII &lsqb;2009&rsqb;, using the dynamic panel estimation method. Our main contributions are testing the existing theories in a novel setting with unique product features and advancing our understanding of the prediction market for sports events.