Institutional quality,financial development and sustainable economic growth among lower income countries

This article postulates strong endogenous relationships in lower income countries between institutional quality, financial development and sustained economic growth. These associations were investigated using the vector-error correction model (VECM) and Granger causality method for a sample of 79 countries from 2005 to 2022. The findings show that (1) these variables reinforce each other in the short run. (2) In the long run, both institutional quality and financial development can fuel economic growth. (3) The positive effect of institutional quality on economic growth is greater than that of financial development. Policy implications of these findings are that careful attention should be paid to co-development policies to enhance the institutional quality and the financial system in these economies. Policies should also consider economic growth strategies to enable sustainable economic growth rates.     

Environmental pollution,hydropower and nuclear energy generation before and after catastrophe: Bathtub-Weibull curve and MS-VECM methods

In this paper, the life span of hydro and nuclear energy generations and the relationship between hydro and nuclear energy generations, environmental pollution, and economic growth were investigated for Japan covering the period of 1960–2018 by employing the Bathtub-Weibull curve and Markov switching-vector error correcting (MSVEC) method, respectively. According to the Bathtub-Weibull curve analysis, a rising failure rate for nuclear energy was found, indicating that the life of nuclear energy has expired, but a decreasing failure rate for hydroelectric energy has been detected. Then two different MSVEC models were used. The MSVEC method, unlike traditional approaches, determines the relationship between variables under different regimes. The results of MSVEC methods indicate three important points. First, regime-dependent asymmetry and regime changes are crucial for policy recommendations. Second, the shocks to hydropower and nuclear energy generations cause temporary deviations from the long-run growth path in both regimes. Lastly, the increase in hydropower generation leads to a decrease in environmental pollution and an increase in GDP, and an increase in nuclear power generation increases pollution and growth in both regimes.     

Discounting in the presence of scarce ecosystem services

The discount rate for cost-benefit analysis has to take account of future scarcity of ecosystem services in consumption and production. Previous literature focuses on the first aspect and shows the importance of the relative price effect, for given growth rates of consumption and ecosystem services. This paper focuses on intermediate ecosystem services in production and shows that for limited substitutability and a low growth rate of these ecosystem services, the growth rate of consumption, and thus the discount rate, declines towards a low value. Using a Ramsey growth model, the paper distinguishes three cases. If ecosystem services can be easily substituted, the discount rate converges to the usual value in the long term. Secondly, if ecosystem services can be easily substituted in production but not in consumption, the relative price effect is important. Finally, and most interestingly, if ecosystem services cannot be easily substituted in production, the discount rate declines towards a low value and the relative price effect is less important. Another part of the previous literature has shown that a declining discount rate is the result of introducing several forms of uncertainty, but this paper reaches that conclusion from an endogenous effect on the growth rate of the economy.     

Community participation in cultural heritage and environmental policy formulation in Botswana

Cultural heritage does not have direct economic benefits. However, if properly managed it can stimulate social cohesions, improving the environment and have beneficial economic spin offs for the local communities. This paper discusses the role of communities in the formulation of the policies concerning their local environment. It argues that community engagement by policy makers is important in giving legitimacy and ownership of the policies. Furthermore, this paper discusses the potential of cultural heritage in diversifying the economy in Botswana. This paper recommends for the re-assessment of the relationship between the state and local communities which is critical in resuscitating the seemingly ailing community business organizations. In conclusion, it argues for the sustainable management of cultural heritage as a social and economic resource in the next 50 years of Botswana’s independence.     

Cd/Sb/Pb复合污染对竺麻生长及吸收富集特征的影响

通过盆栽试验,分析了不同浓度Cd/Sb/Pb复合作用下苎麻的生长响应及重金属吸收、富集和迁移特征变化。结果表明,低浓度Cd/Sb/Pb复合处理对苎麻生长及生物量没有产生明显影响,而高浓度条件下则产生明显抑制效应,株高变矮,茎粗变细及生物量明显减少。苎麻体内Cd、Pb和Sb吸收量与污染土壤具有直接相关性,随复合处理浓度增加明显增大。至最高污染浓度处理时,苎麻体内重金属吸收量以Cd>Sb>Pb,地上部含量分别达335.74 mg/kg、157.55 mg/kg和92.31 mg/kg。复合处理下苎麻地上部对Cd、Sb和Pb的富集系数分别在0.67~0.88、0.13~0.17和0.05~0.06之间,均表现为随复合处理浓度增加而减少变化。苎麻Cd、Sb和Pb的转运系数分别为0.81~0.92、0.38~0.46和0.53~0.73,其中Cd、Sb的转运系数随复合处理浓度增加而增大,Pb则随复合处理浓度增加而减少。苎麻对重金属Cd/Sb/Pb复合污染具有较好吸收累积及转运能力,相比生物量小的植物而言,是目前修复重金属Cd/Sb/Pb复合污染的理想植物。     

淀山湖浮游藻类群落的早期增长

对2004～2009年淀山湖浮游藻类群落生物量[以叶绿素a（Chla）表示]随时间的变化进行了数学模拟.模拟结果表明,Logistic增长模型能够很好地描述淀山湖浮游藻类群落春季和夏季的早期增长.一般说来,淀山湖春季以硅藻和绿藻为主的浮游藻类群落于2月下旬进入指数级增长,到3月上旬浮游藻类密度已经达到始盛点的2倍,浮游...     

西南地区近60年商品材消耗和经济增长关系

首次定义和使用了"GDP黄金当量"作为经济全球化背景下经济增长的新指标。"GDP黄金当量"是指把历年GDP总量按年均汇价和国际黄金市场年均价换算成黄金重量,其可在一定程度上绕开纸币的贬值或升值,反映GDP的贵金属本质,把资源消耗和经济增长的关系分析转变成物物关系分析。研究资源消耗和经济增长的关系有助于提高资源使用效率和调整经济发展方式。通过分析西南地区1949年以来历年商品材产量、人口数量、GDP总量、GDP黄金当量及其单位木材能耗之间的关系,检验了近现代资源环境与经济发展关系中的"资源诅咒"和"库兹涅茨曲线"假设,结果表明:①1952—2008年GDP总量增长了422倍,人口增长了1倍,GDP黄金当量增加了4.5倍,商品材产量增加了12倍;②商品材产量1997—2000年因天然林保护工程下降了80%,然而2008年的946×104m3又恢复到了天然林保护工程前的水平,总体上增长趋势未变;③经济发展出现3个GDP黄金当量"平台",目前处在第3个"平台"上,GDP黄金当量和商品材产量仅前20 a成线性相关(P0.01);④商品材产量和人口数量之间线性相关显著(P0.01),GDP黄金当量和人口数量之间非参数相关显著(P=0.005),人均GDP增长了162倍,人均GDP黄金当量只增长了1.5倍,商品材产量和人均GDP(或人均GDP黄金当量)之间不存在环境库兹涅茨曲线关系,也不存在森林资源诅咒经济增长现象;⑤每万元GDP或每kg GDP黄金当量的商品材消耗量先增加后减少,呈现倒"U"曲线走势,经济发展走过了劳动和森林资源密集型时期。     

尿素对中国近海3种典型赤潮藻生长的影响

采用实验室一次性培养的方法,研究了尿素对中国近海3种赤潮藻---球形棕囊藻(Phaeocystis globosa)、锥状斯氏藻(Scrippsiellatrochoidea)和中肋骨条藻(Skeletonema costatum)生长的影响.结果表明,这3种赤潮藻均能利用有机氮源尿素生长,且表现出明显的浓度效应:当尿素浓度介于0~8.82μmol.L-1(以N计,下同)时,3种赤潮藻的比生长速率均较低,细胞密度也较低,与对照组相比无显著差异;当尿素浓度大于8.82μmol.L-1时,这3种赤潮藻表现出明显的生长效应.然而,3种赤潮藻适宜生长的尿素浓度并不一致,当尿素浓度分别为882、8820和8820μmol.L-1时,球形棕囊藻、锥状斯氏藻和中肋骨条藻分别达到最大比生长率0.76、0.54和0.66d-1.将3种赤潮藻在不同尿素浓度下的最大比生长速率用Monod方程拟合,得出球形棕囊藻、锥状斯氏藻和中肋骨条藻在以尿素为唯一氮源条件下的最大比生长速率和半饱和常数分别为0.73、0.47、0.63d-1和12.36、21.83和20.34μmo.lL-1.由此可见,这3种藻能够利用有机氮源尿素,无疑扩展了其氮营养来源,在无机氮源缺乏时,具有竞争优势.相比较而言,球形棕囊藻对尿素的亲和力最高,在低浓度尿素条件下,球形棕囊藻具有较高的竞争力.     

一株丁草胺降解菌的分离鉴定及培养条件优化

利用富集培养技术从长期施用丁草胺的稻田土壤中分离得到1株能够降解丁草胺的细菌,标记为LYC-2.经形态特征、生理生化特征和16SrDNA序列分析,将该菌株鉴定为钩杆菌属(Ancylobacter sp.).同时,为探索菌株LYC-2的生长特性和最佳培养条件,利用正交试验设计法考察了接种量、温度、pH值3个因素对菌株LYC-2生长的影响.结果表明,菌株LYC-2的最适生长温度为35℃,最适pH值为7.5.当接种量为6%(体积分数,下同)时,该菌株在含100mg.L-1的丁草胺无机盐基础培养液中培养5d后,可使丁草胺降解率达90.85%以上.     

光照与磷对铜绿微囊藻生长的交互作用

采用单种分批培养的方法研究了光照与磷对铜绿微囊藻比生长速率、细胞叶绿素a和P含量的交互作用。通过光照强度和培养基P浓度的双因素试验设计,设置了4种培养基P浓度,每种P浓度下又设置了6种光照强度。结果显示:铜绿微囊藻生长的饱和光照强度为40～100μmol(/m·2s),培养基P浓度对其生长速率的影响符合Monod方程;随着光照增强,细胞叶绿素a含量呈下降趋势;提高P浓度,细胞叶绿素a含量会升高,但在较低P浓度下,铜绿微囊藻也能维持一定的细胞叶绿素a含量;细胞P含量的变化趋势与比生长速率的变化趋势相似。因此,光照和P浓度对铜绿微囊藻的生长、细胞叶绿素a和P含量均存在交互作用,且微囊藻生长变化与另外两种特征变化存在一定的关联。