Search Results (161)

The fight against climate change is gaining momentum, with a growing focus on reducing carbon dioxide (CO₂) emissions and mitigating environmental impacts. Africa, the continent most vulnerable to global warming, faces unique challenges in this context. This study examines the long-term association among CO₂ emissions, economic growth, and different socio-economic factors in 36 African countries from 1990 to 2020. Employing the Pooled Mean Group (PMG) estimator with Autoregressive Distributed Lag (ARDL) model, along with U-test and Dumitrescu and Hurlin causality analyses, our study reveals substantial long-term connections amongst CO₂ emissions and factors such as economic growth, trade openness, renewable energy consumption, urbanization, and population dynamics. The findings support the Environmental Kuznets Curve (EKC) hypothesis, indicating that CO₂ emissions initially increase with GDP per capita growth but begin to decline after a turning point at approximately 10,614.75 USD. However, the evidence for this turning point remains weak, suggesting that most African countries have not yet achieved decoupling. Renewable energy consumption and urbanization are negatively associated with CO₂ emissions, while trade openness and GDP per capita show positive correlations. Causality analysis reveals bidirectional relationships among most variables, except for population growth and CO₂ emissions, which may involve other moderating factors. The findings highlight the urgent need for integrated policies that advance sustainable development by focusing on renewable energy adoption, sustainable urbanization, and green growth strategies. Policymakers should prioritize initiatives that harmonize economic growth with environmental sustainability, ensuring a lasting balance between development and ecological preservation across Africa. Full article

Recently, the recovery of metals extracted from the spent membrane electrode assemblies (MEAs) of fuel cells has attracted significant scientific attention due to its detrimental environmental impacts. Two major approaches, i.e., pyrometallurgical and hydrometallurgical, have been explored to recover platinum group metals (PMGs) from used proton exchange membrane fuel cells (PEMFCs). However, the efficacy of these methods has been limited by the low concentrations of the metals and the high costs involved. Essentially, pyrometallurgical processes result in the evolution of harmful gases. Thus, the hydrometallurgical process is preferred as a suitable alternative. In this review, an overview of the application of pyrometallurgical and hydrometallurgical methods in the recovery of PGMs is presented. The health risks, benefits, and limitations of these processes are highlighted. Finally, the hurdles faced by, opportunities for, and future directions of these approaches are identified. It is envisaged that this review will shed light on the current status of processes for the recovery of spent PGMs and propel their advancement for effective recycling strategies. Full article

Since the Great 2008 Recession, central banks around the world have been coping with monetary consequences that highlight structural costs of the economic system and the rise of unconventional monetary measures. This research aims to capture the heterogeneous effects of expansionary balance sheet (Quantitative easing) policy on the real effective exchange rate and current account balance under the different exchange rate regimes in crisis circumstances. The sample is structured of two groups of EU countries differentiated by level of monetary autonomy: EZ members (Austria, Belgium, France, Germany, Netherlands, Italy, and Spain) are represented by countries with the highest level of asset purchases by ECB and emerging monetary autonomous EU economies (Czech, Hungary, Poland, and Romania). Empirical findings are based on the framework of cross-sectional dependent, non-stationary, heterogeneous, dynamic panels using the (Pooled) Mean Group estimator during the 2014Q1–2023Q1 time horizon. Results indicate a positive long-run relationship between the central bank balance sheet assets, the real interest rate, and the real effective exchange rate. A negative long-term relationship with the current account balance is confirmed, suggesting a diminishing external position. While error-correction parameters are significant and heterogeneous, research confirms higher real effective exchange rate reaction for the EZ members with higher adjustment toward worsening competitiveness along with external balance. Full article

This paper addresses Noether’s problem for p-groups G, having an abelian normal subgroup of index p, under the condition $G^p=\{g^p:g\in G\}\le Z\left(G\right)$—the center of G. We prove that the fixed field $K\left(G\right)=K{(x\left(g\right):g\in G)}^G$ is rational over K in such cases, focusing on both the classification and structural analysis of these groups. Our results extend existing work by removing restrictive assumptions and providing a refined understanding of p-groups and their representations. Full article

The global trend of rapid economic development and urbanization has created questions regarding the quality of the environment. In the group of emerging economies (E7), environmental challenges have intensified due to specific dynamics unique to these nations. This research is focused on determining the influence of urbanization (UBNZ), renewable energy (RWNE), capital formation (CPFR), foreign direct investment (FDIN), and natural resources (NTRR) on the ecological footprint (ECLF) of the E7 economies. The study employs the Panel Autoregressive Distributed Lag (PMG-ARDL) approach to examine these relationships, utilizing data spanning the period of 1990–2022. The results reveal that a 1% increase in the CPFR, NTRR, and UBNZ leads to increases in the ECLF of 0.0581%, 0.0263%, and 0.0299%, respectively. Conversely, a 1% increase in RWNE and FDIN reduces the ECLF by 0.0207% and 0.0556%, respectively, in the E7 economies. The study’s findings are further validated through robustness testing via the fully modified ordinary least squares (FMOLS) method. The study concludes with actionable policy recommendations aimed at enhancing environmental quality within these economies. These recommendations include promoting renewable energy adoption, attracting environmentally sustainable foreign investments, and implementing strategies to manage urbanization and natural resource use effectively. Full article

Environmental quality is a global concern, especially in Gulf Cooperation Council (GCC) countries where abundant mineral resources, economic growth, and globalization have strained the environment through urbanization and resource exploitation. This study examines the impact of globalization (GLOL), urbanization (URBN), natural resource extraction (NRER), institutional quality (INSQ), and foreign direct investment (FDI) on environmental quality in GCC countries from 1999 to 2021. Cross-sectional dependence (CSD) was assessed using the Lagrange Multiplier (LM) and cross-dependence (CD) techniques, and stationarity was confirmed with the Levin–Lin–Chu test. The Augmented Dickey–Fuller (ADF) co-integration test verified long-term relationships, and Pooled Mean Group Autoregressive Distributed Lag (PMG-ARDL) methodology assessed short- and long-term effects. Our findings show that FDI, GLOL, and INSQ have negative long-term impacts on environmental quality, while NRER and URBN are beneficial. In the short term, FDI and INSQ improve green quality, while GLOL, URBN, and NRER have detrimental effects. Policy recommendations include discouraging FDI in non-renewable projects, promoting sustainable FDI, addressing income inequality to improve environmental quality, and investing in urban development to reduce ecological footprints (ECFTs) and enhance environmental quality in GCC countries. Full article

The extraction of excessive natural resources, as well as economic and social development, has created several ecological issues. Therefore, this study examines the effects of globalization (GLZN), digitalization (DGTZ), economic development (ECDV), natural resources use (NRRS), and technological innovation (TCIN) on ecological footprints (EFPR) in G10 economies from 2000 to 2021. We examined the cross-sectional dependence, lack of slope homogeneity, stationarity characteristics through the CIPS unit root test, and panel co-integration among the variables through the Westerlund test. We then used Pooled Mean Group Autoregressive Distributed Lag to examine the long-term and short-term associations, validated by the Hausman test. The empirical findings show that DGTZ and TCIN improve environmental quality by lowering EFPR. However, in G10 economies, ECDV, GLZN, and NRRS reduce environmental quality by increasing the impact of EFPR on the environment. Without sustainable practices, the extraction and consumption of natural resources lead to a higher EFPR, which indicates greater environmental strain. Moreover, the results indicate that TCIN and DGTZ are crucial for environmental protection in the G10; therefore, we should promote their use to maintain ecological sustainability in these economies. Full article

Pathogen-induced fruit decay is a significant threat to the kiwifruit industry, leading to considerable economic losses annually. The cell-wall-degrading enzymes (CWDEs) secreted by these pathogens are crucial for penetrating the cell wall and accessing nutrients. Among them, Diaporthe species are recognized as major causal agents of soft rot in kiwifruit, yet their pathogenic mechanisms are not well understood. In this study, we explored the production of various CWDEs secreted by Diaporthe Z1-1N, including polygalacturonase (PG), polymethylgalacturonase (PMG), polygalacturonic acid transeliminase (PGTE), pectin methyltranseliminase (PMTE), endoglucanase (Cx), and β-glucosidase (β-glu), both in liquid cultures and within infected kiwifruit tissues. Our findings revealed significant activities of two pectinases (PG and PMG) and cellulases (Cx and β-glu) in the infected tissues. In contrast, very low levels of PMTE and PGTE activities were observed under the same conditions. When orange pectin served as the carbon source, PG and PMG showed notable activities, while PMTE and PGTE remained inactive. Moreover, the activities of Cx and β-glu significantly decreased by more than 63 times in the liquid medium with carboxymethyl cellulose (CMC) as the carbon source compared to their levels in infected kiwifruit. A further analysis indicated that the necrotic lesions produced by pectinase extracts were larger than those produced by cellulase extracts. Notably, four enzymes—PG, PMG, Cx, and β-glu—exhibited high activities on the third or fourth day post-infection with Diaporthe Z1-1N. These results suggest that Diaporthe Z1-1N secretes a range of CWDEs that contribute to kiwifruit decay by enhancing the activities of PG, PMG, Cx, and β-glu. This study sheds light on the pathogenicity of Diaporthe in kiwifruit and highlights the importance of these enzymes in the decay process. Full article

The growing concerns about global warming and its perceived influence on economic sustainability require a reassessment of the environmental consequences of gold mining, with a special focus on BRICS countries: Brazil, Russia, India, China, and South Africa. This paper examines the environmental sustainability corridor, carbon emission, gold price, economic growth, foreign direct investment (FDI), and renewable energy use between 1989 and 2020. The long-run association among the variables is checked by us through the PMG technique. Our findings indicate that while the gold price, FDI, and renewable energy use decrease carbon emission, economic growth adds to the increase in carbon emissions in the long run. These findings bring out the dual challenge of promoting economic growth while managing environmental impact. The study underlines how policymakers need to provide regulatory frameworks which will encourage renewable energy and responsible foreign investment, as a means of trying to mitigate the environmental impacts of gold mining and achieve sustainable development. Our research adds to the continuing debate about how economic expansion can be balanced with environmental preservation for resource-rich countries. Full article

In recent years, fiscal policy in the Eurozone (EZ) has faced challenges posed by the strong and rapid increase in inflation as a consequence of the COVID-19 pandemic and other geo-political crises. Due to the fear of “fiscal inflation” present during episodes of fiscal stimulus during the pandemic crisis, this paper assesses the relationship between discretionary fiscal policy and inflation in developed EZ economies, taking into consideration the rise in energy prices as a control variable. This study considers the econometric framework of heterogeneous, non-stationary panels (Pooled Mean Group (PMG) and Common Correlated Effects Mean Group (CCEMG) estimators). Using quarterly panel data for the period 2015q1–2024q1, the results show that, in the long run, the effects of fiscal policy on inflation are insignificant. However, covering only the pandemic and other geo-political crises (2020q1–2024q1), research shows a significant negative long-run relationship between fiscal expenditure and inflation and heterogeneous short-run fiscal adjustments due to the lack of a fiscal union in the EU economies. Hence, accompanied by monetary policy, the discretionary response of fiscal policy to inflationary shock was oriented in the same direction—the reduction in inflationary pressures during a geo-political crisis. Fiscal policy mitigated inflationary pressures in these recent crises, while in the long run, it did not affect nominal variables, indicating that there is no evidence of fiscal inflation in the sample of EZ economies during a stabilization period or under crisis conditions. Full article

This paper examines key driving forces of inflationary pressures, taking into account supply and demand side determinants and actions of policy makers, during the pandemic and geopolitical crises in the Eurozone. Using heterogeneous nonstationary macro-panel models, especially the Mean Group (MG) and Pooled Mean Group (PMG) methods in the period 2020q1–2024q4, it is concluded that the dominant determination of inflationary pressures comes from the supply side. There is a long-run positive equilibrium relationship between the growth of energy prices and the growth of the consumer price index (CPI), and between the index representing supply bottlenecks (SBI) and the growth of CPI, while the relationship with the unemployment rate is insignificant. Also, the existence of a long-run equilibrium between the interest rate and CPI is homogeneous due to the unique monetary policy on a sample, and negative, indicating the efficiency of that policy. However, the speed of adjustment of individual economies is heterogeneous, and in the case of Greece and Ireland, insignificant. The heterogeneous or insignificant response of Eurozone member states, especially related to core-periphery asymmetry, refers to the vulnerability and structural weakness of the Eurozone economies, and the need for deeper integration. Full article

The issue of non-performing loans (NPLs) in a bank’s portfolio is important for a bank’s stability and sustainability. Their increased presence indicates a potential worsening of the economy and a lower quality of the bank’s assets. We estimated determinants of non-performing loans in the Eurozone for quarterly data 2015–2020. The results confirmed spatial spillover effects within Eurozone countries, which means that when a shock happens in one country in the Eurozone, it will also affect the other economies of the Eurozone area. Based on the Hausman test, a fixed-effects model was chosen as appropriate and showed that bank-specific and macroeconomic determinants significantly affect NPLs in these economies. In relation to previous studies that dealt with this issue, a co-integration analysis was introduced. A significant impact of return on assets, return on equity, and the loan-to-deposit ratio, as well as the gross domestic product, inflation, and exchange rate on NPLs in the short run and long run, was confirmed using a Pooled Mean Group (PMG) estimator. Bank management should customize credit policy based on both internal and external conditions to improve their performance, focusing on enhancing profitability and maintaining a lower loan-to-deposit ratio to reduce NPLs. The research suggests that a higher gross domestic product (GDP) growth rate is associated with fewer NPLs, while inflation uncertainty and a volatile exchange rate can increase NPLs, highlighting the importance of adjusting strategies to the macroeconomic landscape. Full article

The present research focuses on the endogenous development theory and investigates the relationships between economic growth (dependent variable) and renewable energy consumption, technological innovation, and export diversification (independent variables) in seven emerging economies known as the E-7. Previous studies have examined these factors individually but have not explored their combined impact on the E-7 economies. Therefore, this study contributes to the existing literature on the effects of renewable energy consumption, technological advancement, and export diversification on economic development. This study analyses the dynamic connections among these variables in seven selected emerging countries: Brazil, China, Indonesia, India, Mexico, Russia, and Turkey. Panel data from 1990 to 2022 are utilised, and various methodologies, including panel cointegration, the pooled mean group–autoregressive distributed lag (PMG-ARDL) estimator, and robustness tests, such as the fully modified ordinary least square and dynamic ordinary least square tests, are employed. Empirical inferences are drawn using the Dumitrescu–Hurlin panel causality (DHC) test, and the long-run relationships among the variables are validated using the Westerlund residual cointegration tests. The results from the PMG-ARDL estimator show that renewable energy consumption, technological advancement, and export diversification have a significant and positive impact on economic expansion, confirming the validity of the endogenous growth model in the E-7 countries. The control variable of the financial sector has a positive but insignificant effect on economic growth, while trade openness has a negative and significant effect. The DHC test results indicate a neutral feedback effect of renewable energy consumption on economic growth. The findings also reveal a unidirectional causal relationship between technological innovation and economic growth. Overall, these findings provide valuable insights for economic policymakers in the E-7 countries. By removing barriers to renewable energy consumption, technological innovation, and export diversification, policymakers can promote sustainable economic development. Full article

Energy is pivotal in achieving sustainable development’s economic, social, and environmental objectives. However, to attain this crucial goal, it is essential to focus on the type of energy we generate and the methods by which we use them. The availability, accessibility, and use of green technologies have improved significantly since the Fourth Industrial Revolution (4IR). This paper applies the pooled mean group Autoregressive Distributed Lag (PMG ARDL) model from 2000 to 2021 to 11 countries that, according to the Climate Council, are most affected by environmental degradation issues and are taking new initiatives to reduce their emissions. The results indicate a significant relationship between renewable energy consumption and technological advancements in the short and long term. However, there needs to be more of the literature about the negative impact of research and development on renewable energy consumption. The findings of this paper can assist policymakers in determining effective strategies in the renewable energy sector, as any technological advancement is an innovative way to transform the renewable energy industry completely. By optimizing energy production and reducing costs, technological advancement can help a country achieve its renewable energy goals. Full article

Anthracnose is one of the destructive diseases of pitaya that seriously affects the plant growth and fruit quality and causes significant yield and economic losses worldwide. However, information regarding the species of pathogens that cause anthracnose in pitaya (Hylocereus undatus) fruits in Gansu Province, China, and its pathogenic mechanism is unknown. Thus, the purposes of our present study were to identify the species of pathogens causing H. undatus fruits anthracnose based on the morphological and molecular characteristics and determine its pathogenic mechanism by physiological and biochemical methods. In our present study, forty-six isolates were isolated from the collected samples of diseased H. undatus fruits and classified as three types (named as H-1, H-2, and H-3), according to the colony and conidium morphological characteristics. The isolation frequencies of H-1, H-2, and H-3 types were 63.04%, 21.74%, and 15.22%, respectively. The representative single-spore isolate of HLGTJ-1 in H-1 type has significant pathogenicity, and finally we identified Colletotrichum truncatum as the pathogen based on the morphological characteristics as well as multi-locus sequence analysis. Moreover, the H. undatus fruits inoculated with C. truncatum had a significantly increased activity of cell wall-degrading enzymes (CWDEs) cellulase (Cx), β-glucosidase (β-Glu), polygalacturonase (PG), and pectin methylgalacturonase (PMG), while having a decreased level of cell wall components of original pectin and cellulose in comparison to control. The average increased activities of Cx, β-Glu, PG, and PMG were 30.73%, 40.40%, 51.55%, and 32.23% from day 0 to 6 after inoculation, respectively. In contrast, the average decreased contents of original pectin and cellulose were 1.82% and 16.47%, respectively, whereas the average increased soluble pectin content was 38.31% in comparison to control. Our results indicate that C. truncatum infection increased the activities of CWDEs in H. undatus fruits to disassemble their cell wall components, finally leading to the fruits’ decay and deterioration. Thus, our findings will provide significant evidence in the controlling of pitaya anthracnose in the future. Full article