448 research outputs found
The use of indicators for unobservable product qualities: inferences based on consumer sorting
Using the dietary supplement black cohosh to demonstrate our method, we employ data on a product characteristic unobservable to consumers to decompose the contribution to consumers’ valuations of observable characteristics into surrogate indicator and direct components. Because consumers are not all “expert appraisers” of the unobservable characteristic, the measured relationship of indicators to the unobservable quality is generally not the one consumers perceive. Consequently, biases that depend upon the nature of consumers’ ineptitude are introduced into the component estimation. The researcher’s inference problem is solved by recognizing that consumers with greater appraisal expertise sort disproportionately to higher quality products. This enables feasible measurement of inept consumers’ relative valuations and conjectures through separate hedonic estimation on high- and low-quality product subsamples. We find that, relative to experts, inept consumers likely underestimate the value of most observable characteristics in indicating black cohosh product authenticity; however they overweight online product ratings.hedonic analysis; surrogate indicators; asymmetric information; pricing strategy; product strategy
Estimating Signal Timing of Actuated Signal Control Using Pattern Recognition under Connected Vehicle Environment
The Signal Phase and Timing (SPaT) message is an important input for research and applications of Connected Vehicles (CVs). However, the actuated signal controllers are not able to directly give the SPaT information since the SPaT is influenced by both signal control logic and real-time traffic demand. This study elaborates an estimation method which is proposed according to the idea that an actuated signal controller would provide similar signal timing for similar traffic states. Thus, the quantitative description of traffic states is important. The traffic flow at each approaching lane has been compared to fluids. The state of fluids can be indicated by state parameters, e.g. speed or height, and its energy, which includes kinetic energy and potential energy. Similar to the fluids, this paper has proposed an energy model for traffic flow, and it has also added the queue length as an additional state parameter. Based on that, the traffic state of intersections can be descripted. Then, a pattern recognition algorithm was developed to identify the most similar historical states and also their corresponding SPaTs, whose average is the estimated SPaT of this second. The result shows that the average error is 3.1 seconds
Effects of Intrinsic Tannins on Metabolome During Sainfoin Ensiling
Condensed tannins (CT) from sainfoin have a high capacity to inhibit proteolysis. The objective of the present study was to investigate the effects of CT (following supplementation of deactivated CT with polyethylene glycol [PEG]) on the metabolome during sainfoin ensiling. In total, 510 metabolites were identified after 60 d of sainfoin ensiling, with 33 metabolites were annotated in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Among those metabolites, phospholipids were the most abundant (72.7% of total 33 metabolites). In addition, 10 up-regulated and 23 down-regulated metabolites, respectively, were identified in the PEG treated group when compared with the control group, after 60 d of ensiling (p \u3c 0.05). Pediococcus (correlated with 20 metabolites, R2 \u3e 0.88, p\u3c 0.05) and Lactobacillus (correlated with 16 metabolites, R2 \u3e 0.88, p \u3c 0.05) were the bacteria most correlated with metabolites. The results suggest antagonistic effects between Lactobacillus and Pediococcus occur during ensiling. The proteolysis decreased partly due to CT inhibiting Pediococcus activity during ensiling, with Pediococcus being significantly and positively correlated with dopamine after 60 d of ensiling (R2=0.8857, p \u3c 0.05)
Management Effects on the Vegetation of Rangeland in the Middle of Southern Slope of Tianshan Mountains
Rangeland degradation is a widespread problem and its restoration remains a major challenge. In recent years, many scientists have discussed the primary causes of over-grazing and approaches to restoration of China’s grasslands (e.g. Harris 2010; Wang and Han 2005; Lu et al. 2005). The major evidence of grassland degradation is lower plant productivity, reduced biodiversity and increase in poisonous weeds (Zhao et al. 2010), increased frequency of rodent and grasshopper infestations, and large scale dust storms (Lu et al. 2005). Restoration of these impacted ecosystems is an important and challenging task, especially in Xinjiang Province, China, where the natural grassland is rapidly degrading year by year (Yuan et al. 2011). Many strategies have been used to restore condition to these degrading grasslands, but since not all have proved successful, efforts are continuing to find methods that promote vigorous growth low soil disturbance and minimal vegetation destruction. In this study we investigated the response of grassland species and soils to strategic rest and shallow cultivation relative to current overgrazed grassland in the Tianshan Mountains of the Xinjiang Uyghur Autonomous Region, China
PpNAC187 Enhances Lignin Synthesis in ‘Whangkeumbae’ Pear (Pyrus pyrifolia) ‘Hard-End’ Fruit
A disorder in pears that is known as ‘hard-end’ fruit affects the appearance, edible quality, and market value of pear fruit. RNA-Seq was carried out on the calyx end of ‘Whangkeumbae’ pear fruit with and without the hard-end symptom to explore the mechanism underlying the formation of hard-end. The results indicated that the genes in the phenylpropanoid pathway affecting lignification were up-regulated in hard-end fruit. An analysis of differentially expressed genes (DEGs) identified three NAC transcription factors, and RT-qPCR analysis of PpNAC138, PpNAC186, and PpNAC187 confirmed that PpNAC187 gene expression was correlated with the hard-end disorder in pear fruit. A transient increase in PpNAC187 was observed in the calyx end of ‘Whangkeumbae’ fruit when they began to exhibit hard-end symptom. Concomitantly, the higher level of PpCCR and PpCOMT transcripts was observed, which are the key genes in lignin biosynthesis. Notably, lignin content in the stem and leaf tissues of transgenic tobacco overexpressing PpNAC187 was significantly higher than in the control plants that were transformed with an empty vector. Furthermore, transgenic tobacco overexpressing PpNAC187 had a larger number of xylem vessel elements. The results of this study confirmed that PpNAC187 functions in inducing lignification in pear fruit during the development of the hard-end disorder. View Full-Tex
Effects of adding Allium mongolicum Regel powder and yeast cultures to diet on rumen microbial flora of Tibetan sheep (Ovis aries)
The purpose of this experiment was to study the effect of Allium mongolicum Regel powder (AMR) and yeast cultures (YC) on rumen microbial diversity in Tibetan sheep in different Ecological niches. A total of 40 male Tibetan lambs with an initial weight of 18.56 ± 1.49 kg (6 months old) were selected and divided into four groups (10 sheep/pen; n = 10). In the Control Group, each animal was grazed for 8 h per day, in Group I, each animal was supplemented with 200 g of concentrate per day, in Group II, each animal was supplemented with 200 g of concentrate and 10 g of AMR per day, in Group III, each animal was supplemented with 200 g of concentrate and 20 g of YC per day. The experiment lasted 82 days and consisted of a 7-day per-feeding period and a 75-day formal period. The results indicated that at the phylum level, the abundance of Bacteroidota and Verrucomimicrobiota in L-Group II and L-Group III was increased, while the abundance of Proteobacteria was decreased in the LA (Liquid-Associated) groups. The proportion of F/B in S-Group II and S-Group III was increased compared to S-Group I and S-CON in the SA (Soild-Associated) group. At the genus level, the abundance of uncultured_rumen_bacterium and Eubacterium_ruminantium_group in L-Group II and L-Group III was increased. Furthermore, while the abundance of Rikenellaceae_RC9_gut_group was decreased in the LA, the abundance of Prevotella and Eubacterium_ruminantium_group was increased in the S-Group II and S-Group III compared to S-Group I and S-CON. The abundance of probable_genus_10 was the highest in S-Group II in the SA group. After the addition of YC and AMR, there was an increase in rumen microbial abundance, which was found to be beneficial for the stability of rumen flora and had a positive impact on rumen health
A Bayesian Method for Water Resources Vulnerability Assessment: A Case Study of the Zhangjiakou Region, North China
Water resources vulnerability (WRV) assessment is an important basis for maintaining water resources security in a basin. In this paper, considering the complexity of the water resources system and the uncertainty of the assessment information, a method based on the Bayesian theory was developed for performing WRV assessments while using the constructed indicator system. This system includes four subsystems, the hydrological subsystem, the socioeconomic subsystem, the ecoenvironmental subsystem and the hydraulic engineering subsystem. The WRV degree for each subsystem and the integrated water resources system were assessed. Finally, the assessment results and the characteristics of the Bayesian method were compared with those of the grey relational analysis method and the parametric-system method. The results showed the following
Long-term bicycle riding ameliorates the depression of the patients undergoing hemodialysis by affecting the levels of interleukin-6 and interleukin-18
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