CO2 emissions,nuclear energy,renewable energy and economic growth in the US

This study explores the causal relationship between carbon dioxide (CO₂) emissions, renewable and nuclear energy consumption and real GDP for the US for the period 1960–2007. Using a modified version of the Granger causality test, we found a unidirectional causality running from nuclear energy consumption to CO₂ emissions without feedback but no causality running from renewable energy to CO₂ emissions. The econometric evidence seems to suggest that nuclear energy consumption can help to mitigate CO₂ emissions, but so far, renewable energy consumption has not reached a level where it can make a significant contribution to emissions reduction.     

定向凝固Ti—43Al—3Si合金的组织演化规律 Ⅱ.稳态生长区组织演化规律

分析了定向凝固Ti-43Al-3si(原子分数,%)合金在3-90μm/s的生长速度下的稳态生长区组织.在定向凝同过程中经历下列反应:L→Ti5Si3,L→α+Ti5Si3,α→α2(Ti3Al)+γ(TiAl),α2→γ+Ti5Si3,其中,α与Ti5Si3共晶是合金最显著的凝同行为.当生长速度大于20μm/s时,还出现L→γ+Ti5Si3.随着生长速度增大,稳态组织逐渐由粗胞晶向细胞晶、胞状枝晶及枝晶转变,起稳定α相作用的Ti5Si3相由低速时分布于α相中逐渐向高速时分布于凝固γ相中转变,不利于该合金的引晶.选择10/μm/s的初始生长速度,既能减少到达稳态生长的距离,又能保证引晶效果.     

WE43镁合金的力学性能

对WE43镁合金进行固溶和固溶后不同时间时效的热处理,得到五种热处理状态。分别对五种状态合金进行静态拉伸力学性能测试。用光学显微镜观察不同镁合金的金相组织,用SEM观察微观组织和断口形貌,用光学显微镜观察与断口相对应的显微组织。最后分析固溶和固溶后时效热处理下,WE43镁合金的显微组织和力学性能的关系。     

固溶处理对挤压态WE43镁合金显微组织和晶粒度的影响

在300~450 ℃固溶温度下对挤压态WE43镁合金进行不同时间的固溶处理,研究了固溶温度及时间对WE43镁合金组织和晶粒度的影响。结果表明,固溶处理后,合金中Mg12Nd和Mg-Y-Nd相发生溶解,含量减少,且沿晶界断续分布。固溶温度对挤压态WE43镁合金的晶粒尺寸起决定性作用,在380 ℃固溶处理1 h时,合金晶粒尺寸最为理想,且析出相含量较少。     

Molecular and Structural Parallels between Gluten Pathogenic Peptides and Bacterial-Derived Proteins by Bioinformatics Analysis

Gluten-related disorders (GRDs) are a group of diseases that involve the activation of the immune system triggered by the ingestion of gluten, with a worldwide prevalence of 5%. Among them, Celiac disease (CeD) is a T-cell-mediated autoimmune disease causing a plethora of symptoms from diarrhea and malabsorption to lymphoma. Even though GRDs have been intensively studied, the environmental triggers promoting the diverse reactions to gluten proteins in susceptible individuals remain elusive. It has been proposed that pathogens could act as disease-causing environmental triggers of CeD by molecular mimicry mechanisms. Additionally, it could also be possible that unrecognized molecular, structural, and physical parallels between gluten and pathogens have a relevant role. Herein, we report sequence, structural and physical similarities of the two most relevant gluten peptides, the 33-mer and p31-43 gliadin peptides, with bacterial pathogens using bioinformatics going beyond the molecular mimicry hypothesis. First, a stringent BLASTp search using the two gliadin peptides identified high sequence similarity regions within pathogen-derived proteins, e.g., extracellular proteins from Streptococcus pneumoniae and Granulicatella sp. Second, molecular dynamics calculations of an updated α-2-gliadin model revealed close spatial localization and solvent-exposure of the 33-mer and p31-43 peptide, which was compared with the pathogen-related proteins by homology models and localization predictors. We found putative functions of the identified pathogen-derived sequence by identifying T-cell epitopes and SH3/WW-binding domains. Finally, shape and size parallels between the pathogens and the superstructures of gliadin peptides gave rise to novel hypotheses about activation of innate immunity and dysbiosis. Based on our structural findings and the similarities with the bacterial pathogens, evidence emerges that these pathologically relevant gluten-derived peptides could behave as non-replicating pathogens opening new research questions in the interface of innate immunity, microbiome, and food research.     

Price vs quantity in duopoly supergames with close substitutes

We model the non-cooperative choice between quantity and price in order to stabilize collusion with horizontally differentiated goods, through two meta-games where each firm alternatively considers its payoff in the market supergame as directly related to its own or the rivals ability to collude. In the first setting, firms collude in prices irrespective of the degree of differentiation, so that initially a Prisoners Dilemma is observed, while for very close substitutes the outcome is Pareto-efficient. In the second setting, the Nash equilibrium is unique and Pareto-efficient for the most part of the substitutability range, while two asymmetric equilibria obtain when products are very close substitutes.The first version of this paper was written while both authors were at the Institute of Economics, University of Copenhagen. The views expressed in this article do not necessarily reflect those of the European Commission. We thank three anonymous referees and the audience at a seminar in Copenhagen for useful comments. The usual disclaimer applies.Received: March 2003/Accepted: September 2003     

A consideration of the “no-black-hole” condition

The purpose of this paper is to investigate the economic interpretation of the no-black-hole condition (NBHC) described in the Chapt. 4 of the book by Fujita, Krugman and Venables (1999), under the context of a more general model. The main findings are as follows. First, there is the case in which the NBHC does not hold even though the real wage falls at the symmetric equilibrium. Secondly, the NBHC in the more general model requires both a reduction in profits in response to an increase in the number of firms and a fall in the real wage rate in response to an increase in labor at the symmetric equilibrium. Thirdly, we show that NBHCs obtained in some analyses are special cases of our model. Moreover, we show that the NBHC includes the stability condition for the short-run equilibrium. Therefore the NBHC is not affected by relative speed of labor movement and entry/exit of firms.Received: November 2002/Accepted: March 2004     

Tonabersat Inhibits Connexin43 Hemichannel Opening and Inflammasome Activation in an In Vitro Retinal Epithelial Cell Model of Diabetic Retinopathy

This study was undertaken to evaluate the connexin hemichannel blocker tonabersat for the inhibition of inflammasome activation and use as a potential treatment for diabetic retinopathy. Human retinal pigment epithelial cells (ARPE-19) were stimulated with hyperglycemia and the inflammatory cytokines IL-1β and TNFα in order to mimic diabetic retinopathy molecular signs in vitro. Immunohistochemistry was used to evaluate the effect of tonabersat treatment on NLRP3, NLRP1, and cleaved caspase-1 expression and distribution. A Luminex cytokine release assay was performed to determine whether tonabersat affected proinflammatory cytokine release. NLRP1 was not activated in ARPE-19 cells, and IL-18 was not produced under disease conditions. However, NLRP3 and cleaved caspase-1 complex formation increased with hyperglycemia and cytokine challenge but was inhibited by tonabersat treatment. It also prevented the release of proinflammatory cytokines IL-1β, VEGF, and IL-6. Tonabersat therefore has the potential to reduce inflammasome-mediated inflammation in diabetic retinopathy.     

热处理对挤压铸造ZA43-Mn合金组织和性能的影响

研究了热处理对冲头式挤压铸造ZA43 Mn合金显微组织和力学性能的影响。结果表明 :挤压铸造ZA43 Mn合金的时效处理使α和 β相分解 ,枝晶偏析减轻 ,富锰相碎化与钝化 ,可提高其塑性 (δ5=18% )。固溶处理使富锰相和富铜相分解 ,基体内二次相弥散析出 ,晶间组织形态和分布改善 ,可获得较高强度的铸件 (σb=5 10MPa)     

变质ZA43合金中稀土的存在形式

通过电子探针附带扫描背散射电子成像（sEM）观察分析了ZA43合金的显微结构和相组成。利用电子探针对合金中各相的元素分布进行了分析。研究了变质ZA43合金铸态组织中含0．15％混合稀土的存在形式。实验结果表明，稀土元素主要分布于合金组织的晶界上，并以稀土金属化合物的形式存在。在枝晶中心和枝晶边缘没有发现稀土元素。稀土在α相的边缘含量较低，在η相中未见存在。ZA43合金经稀土调质，细化了合金晶粒。