The social profitability of rural roads in a small open economy: Do urban agglomeration economies matter?

The effects of a rural roads programme depend on labour mobility, how the programme is financed, and agglomeration economies. If financed by a rural poll tax and cross-price effects and agglomeration economies are sufficiently small, the wage will rise, with some return migration. Taxes on trade act as countervailing distortions, yielding urban households some relief. Rural-urban commuting promotes the exploitation of agglomeration economies; taxes on international trade are then inferior to a poll tax. The change in the value, at producer prices, of the rural sector's net supply vector can be a poor measure of the programme's social profitability.     

MHD mixed convection of a Cu–water nanofluid flow through a channel with an open trapezoidal cavity and an elliptical obstacle

In the current work, numerical simulations are achieved to study the properties and the characteristics of fluid flow and heat transfer of (Cu–water) nanofluid under the magnetohydrodynamic effects in a horizontal rectangular canal with an open trapezoidal enclosure and an elliptical obstacle. The cavity lower wall is grooved and represents the heat source while the obstacle represents a stationary cold wall. On the other hand, the rest of the walls are considered adiabatic. The governing equations for this investigation are formulated, nondimensionalized, and then solved by Galerkin finite element approach. The numerical findings were examined across a wide range of Richardson number (0.1 ≤ Ri ≤ 10), Reynolds number (1 ≤ Re ≤ 125), Hartmann number (0 ≤ Ha ≤ 100), and volume fraction of nanofluid (0 ≤ φ ≤ 0.05). The current study's findings demonstrate that the flow strength increases inversely as the Reynolds number rises, which pushes the isotherms down to the lower part of the trapezoidal cavity. The Nu_avg rises as the Ri rise, the maximum Nu_avg = 10.345 at Ri = 10, Re = 50, ϕ = 0.05, and Ha = 0; however, it reduces with increasing Hartmann number. Also, it increase by increasing ϕ, at Ri = 10, the Nu_avg increased by 8.44% when the volume fraction of nanofluid increased from (ϕ = 0–0.05).     

Lipids and Fatty Acids of the Gonads of Sea Urchin Diadema setosum (Echinodermata) From the Coastal Area of the Nha Trang Bay,Central Vietnam

The sea urchin Diadema setosum is edible and desirable as food by locals in central Vietnam and a promising target for potential fishing. The lipid profiles of the gonads of the sea urchin inhabiting the coastal area in Nha Trang Bay are studied for the first time. The determination of the content of the total lipids (TL), total phospholipids (PL), monoacylglycerols (MAG), diacylglycerols (DAG), triacylglycerols (TAG), cholesterol (Chol), sterol esters, and free fatty acids (FFA) is analyzed by high-performance thin layer chromatography (HPTLC); the phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and sphingomyelin (SM) are determined by high-pressure liquid chromatography (HPLC); and the fatty acid levels of TLs are identified using gas chromatography (GC). Non-polar TAG, FFA, Chol, and DAG dominated. The content of total PL is significant. PC is abundant among PL fractions, followed by PE, PI, and PS. The TLs contain a high proportion of PUFA, mainly due to arachidonic fatty acid and eicosapentanoic fatty acid. The (n−6)/(n−3) ratio is 1.68, and the atherogenic and thrombogenic indexes of D. setosum are 1.13 and 0.73. The results can be used in the development of marine bioprospecting and methodological approaches for the creation of functional substances.     

Crosstalk between MicroRNA and Oxidative Stress in Primary Open-Angle Glaucoma

Reactive oxygen species (ROS) plays a key role in the pathogenesis of primary open-angle glaucoma (POAG), a chronic neurodegenerative disease that damages the trabecular meshwork (TM) cells, inducing apoptosis of the retinal ganglion cells (RGC), deteriorating the optic nerve head, and leading to blindness. Aqueous humor (AH) outflow resistance and intraocular pressure (IOP) elevation contribute to disease progression. Nevertheless, despite the existence of pharmacological and surgical treatments, there is room for the development of additional treatment approaches. The following review is aimed at investigating the role of different microRNAs (miRNAs) in the expression of genes and proteins involved in the regulation of inflammatory and degenerative processes, focusing on the delicate balance of synthesis and deposition of extracellular matrix (ECM) regulated by chronic oxidative stress in POAG related tissues. The neutralizing activity of a couple of miRNAs was described, suggesting effective downregulation of pro-inflammatory and pro-fibrotic signaling pathways, including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), transforming growth factor-beta 2 (TGF-β2), Wnt/β-Catenin, and PI3K/AKT. In addition, with regards to the elevated IOP in many POAG patients due to increased outflow resistance, Collagen type I degradation was stimulated by some miRNAs and prevented ECM deposition in TM cells. Mitochondrial dysfunction as a consequence of oxidative stress was suppressed following exposure to different miRNAs. In contrast, increased oxidative damage by inhibiting the mTOR signaling pathway was described as part of the action of selected miRNAs. Summarizing, specific miRNAs may be promising therapeutic targets for lowering or preventing oxidative stress injury in POAG patients.     

Electrochemical Quantification of Neurotransmitters in Single Live Cell Vesicles Shows Exocytosis is Predominantly Partial

Exocytosis plays an essential role in the communication between cells in the nervous system. Understanding the regulation of neurotransmitter release during exocytosis and the amount of neurotransmitter content that is stored in vesicles is of importance, as it provides fundamental insights to understand how the brain works and how neurons elicit a certain behavior. In this minireview, we summarize recent progress in amperometric measurements for monitoring exocytosis in single cells and electrochemical cytometry measurements of vesicular neurotransmitter content in individual vesicles. Important steps have increased our understanding of the different mechanisms of exocytosis. Increasing evidence is firmly establishing that partial release is the primary mechanism of release in multiple cell types.     

User idea implementation in open innovation communities: Evidence from a new product development crowdsourcing community

In collaborative crowdsourcing communities for open innovation, users generate and submit ideas as idea co‐creators. Firms then select and implement valuable ideas for new product development. Despite the popularity and success of these open innovation communities, relatively little is known about the factors that determine the implementation of the user‐generated ideas. Based on research on individual creativity, we propose a conceptual model integrating users' previous experience, idea presentation characteristics and feedback valence to explain the likelihood of idea implementation. We validate our research model with a panel data analysis of 43 550 ideas submitted by 16 360 users in the MIUI new product development community hosted by Xiaomi, a large electronics manufacturing company in China. We find an inverted U‐shaped relationship between users' past successful experience and idea implementation. Furthermore, the length of ideas is positively associated with the likelihood of idea implementation. There is also an inverted U‐shaped relationship between supporting evidence and idea implementation. Finally, we demonstrate the negative effect of positive feedback and the positive effect of negative feedback on idea implementation. These findings offer rich insights to understand the phenomenon of open innovation better. Theoretical and practical implications are discussed.     

露天矿多煤层软岩复合边坡底摩擦实验研究

以新疆某露天矿设有排土场的东帮复合边坡为研究对象,采用正交设计法设计实验方案,研究利用底摩擦实验相似模拟边坡的破坏过程。4种典型露天矿生产状态模型的底摩擦实验全面反映了露天矿多煤层软岩复合边坡的破坏过程,实验结果表明:21煤底板弱层是边坡滑动的关键因素,结合监测点位移变化规律分析得复合边坡的潜在滑移面具有4种形态,直线形、斜直线形、折线形、圆弧曲线形,通过分析实验现象得出边坡的破坏模式有2种,沉降、蠕滑-拉裂。讨论了弱层、时间和排土场对边坡稳定的影响以及底摩擦实验需要改进的地方,提出了提高边坡稳定性的合理加固时间,上覆排土场对边坡稳定性具有的两面性,它与弱层共同控制了潜在滑体的规模,以及合理制作底摩擦模型的重要性。     

鄂尔多斯盆地奥陶系马家沟组五段膏盐下白云岩储层形成的主控因素

近期勘探实践表明，鄂尔多斯盆地东部奥陶系马家沟组五段膏盐下白云岩具有良好的天然气勘探开发潜力。为此，综合岩心观察、薄片鉴定、物性分析及地球化学特征等资料，对其岩石学、储集空间和孔渗特征等开展了系统研究。结果表明，鄂尔多斯盆地奥陶系膏盐下储集层为孔隙型白云岩储层，纵向上分布在马五6亚段、马五7亚段和马五9亚段。马五6亚段储集层岩性主要为颗粒白云岩和斑状粉晶白云岩，马五7亚段和马五9亚段储集层岩性主要为颗粒白云岩和粉-细晶白云岩。三个储层段储集空间均以溶蚀孔洞为主，次为残余粒间孔、晶间溶孔、晶间孔和微裂缝，平均孔隙度分别为5.84%、6.81%和7.03%。沉积古地貌、海平面变化和准同生期大气淡水溶蚀作用等因素共同控制膏盐下白云岩储集层的发育与分布。研究认为位于盐岩边界线外侧的中央古隆起带和榆林-横山隆起带地势相对较高，颗粒滩沉积厚度大，在准同生期和浅埋藏期易于发生大气淡水溶蚀作用，其内部赋存的孔隙不易被膏盐岩充填，是盆地内膏盐下有利白云岩储集层的发育区。     

海参硫酸软骨素的荧光标记方法

海参硫酸软骨素是海参体壁的重要组成物质之一,已被证实具有多种生理调节功能,在功能食品开发方面展现出良好的应用前景。与其他碳水化合物类似,海参硫酸软骨素缺乏特异的发色及发光基团。基于此背景,本研究旨在对海参硫酸软骨素进行荧光标记。以6-氨基荧光素为荧光染料并配合溴化氢活化法成功对该多糖进行了荧光衍生,每分子标记产物中约含4.4分子荧光染料,其最佳荧光激发波长为495 nm、发射波长为520 nm。分子质量测定、硫酸根质量分数测定及傅里叶变换红外光谱比较分析的结果表明,标记前后多糖的结构特征未发生明显变化,标记产物在中性及碱性环境中展现出较强的荧光强度及稳定性,溶液环境中的NaCl对标记产物的影响有限。海参硫酸软骨素荧光标记方法的建立为后续研究该多糖的吸收代谢过程、功能机理、生物分子间相互作用等科学问题提供了有利条件。