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Governments have recently become increasingly concerned about environmental policy choice in a mixed economy because many countries are mixed economies where public and private firms engage in the output market. This paper provides an analytical framework to compare emission taxes and emission standards in a mixed economy. Through theoretical analysis and numerical example, two main conclusions are drawn. First, the ranking of emission taxes and standards in the aspect of bringing about greater social welfare depends on the policy stringency. More specifically, for high levels of environmental stringency, taxes yield a greater social welfare than the standards regulation does, while the opposite conclusion holds for low levels of environmental stringency. Second, the total production level under emission taxes is always larger than under emission standards. Our findings provide important implications for the policy choice and design in a mixed economy.

Abstract Background Heterosis is a phenomenon in which hybrids exhibit superior performance relative to parental phenotypes. In addition to the heterosis of above-ground agronomic traits on which most existing studies have focused, root heterosis is also an indispensable component of heterosis in the entire plant and of major importance to plant breeding. Consequently, systematic investigations of root heterosis, particularly in reproductive-stage rice, are needed. The recent advent of RNA sequencing technology (RNA-Seq) provides an opportunity to conduct in-depth transcript profiling for heterosis studies. Results Using the Illumina HiSeq 2000 platform, the root transcriptomes of the super-hybrid rice variety Xieyou 9308 and its parents were analyzed at tillering and heading stages. Approximately 391 million high-quality paired-end reads (100-bp in size) were generated and aligned against the Nipponbare reference genome. We found that 38,872 of 42,081 (92.4%) annotated transcripts were represented by at least one sequence read. A total of 829 and 4186 transcripts that were differentially expressed between the hybrid and its parents (DGHP) were identified at tillering and heading stages, respectively. Out of the DGHP, 66.59% were down-regulated at the tillering stage and 64.41% were up-regulated at the heading stage. At the heading stage, the DGHP were significantly enriched in pathways related to processes such as carbohydrate metabolism and plant hormone signal transduction, with most of the key genes that are involved in the two pathways being up-regulated in the hybrid. Several significant DGHP that could be mapped to quantitative trait loci (QTLs) for yield and root traits are also involved in carbohydrate metabolism and plant hormone signal transduction pathways. Conclusions An extensive transcriptome dataset was obtained by RNA-Seq, giving a comprehensive overview of the root transcriptomes at tillering and heading stages in a heterotic rice cross and providing a useful resource for the rice research community. Using comparative transcriptome analysis, we detected DGHP and identified a group of potential candidate transcripts. The changes in the expression of the candidate transcripts may lay a foundation for future studies on molecular mechanisms underlying root heterosis.

Objective: To investigate the effects of different intensities of aerobic exercise on the morphology of the atrioventricular node and the expressions of vascular endothelial growth factor (VEGF), vasoactive intestinal peptide (VIP) and synaptophysin (Syn) in rats. Methods: Three-month-old SD rats were randomly divided into 3 groups: quiet control group (C), moderate-intensity aerobic exercise group (AE), and high-intensity aerobic exercise group (FE), each with 8 rats. The moderate-intensity aerobic exercise and high-intensity aerobic exercise rat models were rats established by using 8-week treadmill training ways. Results: Compared with the quiet control group, in the moderate-intensity aerobic exercise group, the atrioventricular nodule muscle fibers were evenly distributed, with smaller gaps, a sense of transparency, and collagen tightly wraps around the atrioventricular nodules. The intercalary disc had a clear structure and complete connection, and the capillary tube wall was relatively clear. Thick elastic fibers were more developed, the expression levels of VEGF and VIP in the atrioventricular node were increased significantly ( P ＜0.05), and there was no significant change in the expression of Syn. In the high-intensity aerobic exercise group, the atrioventricular nodule muscle fibers were unevenly distributed and arranged abnormally, connection between cells were disordered, and vacuolated. The intercalary disk was twisted, circling and overlapping, fuzzy, discontinuous, and extremely dilated. The wall was thick and the endothelial cells were arranged sparsely and disorderly. Moreover, high-intensity aerobic exercise significantly inhibited the expressions of VEGF, VIP, and Syn ( P ＜0.05). Conclusion: Aerobic exercise training of different intensities has obvious effects on the morphology and structure of the atrioventricular node and the expressions of VEGF, VIP and Syn. Moderate aerobic exercise can maintain and promote the normal morphology and structure of the atrioventricular node, while high-intensity aerobic exercise can damage the morphology and structure of the ventricular node, which is presumably closely related to the arrhythmia induced by high-intensity exercise.

Objective: To observe the effect of Yiqi Huoxue Qingre Huashi Recipe (YHQHR, a recipe capable of supplementing qi, activating blood, clearing heat, and dissipating dampness) on ulcer healing and Helicobacter pylori (Hp) eradication rate in Hp positive peptic ulcer patients, and to explore coccoid Hp occurrence in the eradication., Methods: Totally 80 Hp positive peptic ulcer patients were assigned to the treatment group and the control groups by random digit table, 40 in each group. All patients received standard triple therapy of Western medicine for 2 successive weeks. Those in the control group additionally took omeprazole enteric coated tablet, 20 mg each time, once per day for 4 successive weeks. Those in the treatment group additionally took YHQHR, twice per day for 6 successive weeks. The ulcer healing was observed and recorded by gastroscope after discontinued medication of 14 days. The effective rate of ulcer healing under endoscope was statistically calculated. Rapid urease test (RUT) was performed in one small piece of tissue from corpora ventriculi and sinuses ventriculi using 14C breathe test (UBT). Gastric juice was collected from the stomach. Hp urease gene amplification test (urea A-PCR) was performed in living tissue from gastric antrum. Results obtained from the above three test methods were recorded and assessed to decide the final eradiation rate. Gastric mucosa tissue was observed under electron microscope,attempting to find non-eradicated Hp, which was further observed., Results: The total curative effect under gastroscope was 97.5% (39/40 cases) in the treatment group, obviously higher than that in the control group (80.0%, 32/40 cases) (P < 0.05). The eradication rate of Hp was 75.0% (30/40 cases), obviously better than that of the control group (52.5%, 21/40 cases) (P < 0.05). The total positive Hp numbers after treatment was 14C UBT (12), RUT (8), and urea A-PCR (27), respectively. The Hp positive rate detected by 14C UBT and RUT was lower than the Hp positive rate detected by urea A-PCR (P < 0.05). Rod-like and coccoid Hp bacteria could be observed under electron microscope., Conclusion: YHQHR combined standard triple therapy was more effective than standard triple therapy alone in promoting ulcer healing and elevating the eradication rate of Hp.

Objective: To observe the effect of Dahuang Zhechong Pill (DZP) on the content of amino acids in hippocampal tissue of model rats of ischemic cerebral hemorrhage (ICH)., Methods: Collagenase and heparin were injected into caudate nucleus to establish ICH rat model. The content of glutamic acid (Glu), aspartic acid (Asp) and gamma-aminobutyric acid (GABA) in hippocampal tissue was detected by anti-phase high-performance liquid chromatographic fluorimetry to observe the effect of DZP on the content of amino acids in brain tissue., Results: Three days after modeling, the content of Glu, Asp and GABA was significantly higher in the model group than those in the sham-operation and the normal control group (P < 0.05), for Glu 15.2926 +/- 4.2429 micromol/g vs 8.0057 +/- 1.1227 micromol/g and 8.5040 +/- 1.7794 micromol/g, for Asp 3.6384 +/- 3.1021 micromol/g vs 1.4986 +/- 0.4174 micromol/g and 1.2669 +/- 0.4695 micromol/g, and for GABA 0.3859 +/- 0.1846 micromol/g vs 0.1829 +/- 0.04665 micromol/g and 0.1770 +/- 0.0472 micromol/g. The content of Glu (9.0550 +/- 1.7195 micromol/g), Asp (1.8085 +/- 0.6862 micromol/g) and GABA (0.1993 +/- 0.0424 micromol/g) in hippocampal tissue in the DZP group was reduced significantly, as compared with that in the model group (P <0.05)., Conclusion: DZP could reduce the release of excitatory amino acids (EAA-Glu, ASP) to balance EAA/inhibitory amino acid (IAA), so as to relieve ICH-induced brain injury.