Asymmetric Linkages Research Articles

Natural selection on HLA-DPB1 amino acids operates primarily on DP serologic categories

The DPB1 locus is notable among the classical HLA loci in that allele frequencies at this locus are consistent with genetic drift, whereas the frequencies of specific DPβ amino acids are consistent with the action of balancing selection. We investigated the influence of natural selection in shaping the diversity of three functional categories of DPB1 diversity defined by specific amino acid motifs, DPB1 T-cell epitopes, DPB1 supertypes and DP1-DP4 serologic categories (SCs), via Ewens-Watterson (EW) selective neutrality and asymmetric Linkage Disequilibrium (ALD) analyses in a worldwide sample of 136 populations. These EW analyses provide strong evidence for the operation of balancing selection on DP SCs, but no evidence for balancing selection on T-cell epitopes or supertypes. We further investigated the global distribution of SCs. Each SC is common in a different region of the world, with the DP1 SC most common in Southeast Asia and Oceania, the DP2 SC in North and South America, the DP3 SC in South America, and the DP4 SC in Europe. The DP2 SC is present in all populations, while 14% of populations are missing at least one DP1, DP3, or DP4 SC. We observed consistent DPA1∼DP SC haplotype associations across 10 populations from five global regions, and found that asymmetric linkage disequilibrium (LD) between the DPB1 locus and the four most-common DPA1 alleles (DPA1*01:03, *02:01, *02:02 and *03:01) is determined by variation at DPβ AA positions 85–87. These positions are in LD with both DPα positions 31 and 50. We conclude from these EW analyses that natural selection is primarily operating to maintain population-level diversity of DP SCs, rather than DPB1 alleles or other functional categories of DPB1 diversity.

Population genetic dissection of HLA-DPB1 amino acid polymorphism to infer selection

Although allele frequency data for most HLA loci provide strong evidence for balancing selection at the allele level, the DPB1 locus is a notable exception, with allele frequencies compatible with neutral evolution (genetic drift) or directional selection in most populations. This discrepancy is especially interesting as evidence for balancing selection has been seen at the nucleotide and amino acid (AA) sequence levels for DPB1. We describe methods used to examine the global distribution of DPB1 alleles and their constituent AA sequences. These methods allow investigation of the influence of natural selection in shaping DPβ diversity in a hierarchical fashion for DPB1 alleles, all polymorphic DPB1 exon 2-encoded AA positions, as well as all pairs and trios of these AA positions. In addition, we describe how asymmetric linkage disequilibrium for all DPB1 exon 2-encoded AA pairs can be used to complement other methods. Application of these methods provides strong evidence for the operation of balancing selection on AA positions 56, 85–87, 36, 55 and 84 (listed in decreasing order of the strength of selection), but no evidence for balancing selection on DPB1 alleles.

Asymmetric Effects of Development Finance Institutions Funding (DFIs) on Investment in Zimbabwe: A Futuristic Perspective

Introduction - This study aimed to explore the anticipated asymmetric effects of developmental finance institutions (DFIs) funding on investment in Zimbabwe. Given the volatile nature of development finance, Zimbabwe has faced challenges in effectively mobilizing aid, often struggling to persuade donors due to government spending plans and political factors. The research sought to investigate the potential asymmetrical linkages between DFIs funding and investment in Zimbabwe. Methodology: Model and Variables - To examine the futuristic asymmetric relationship between DFIs funding and investment in the Zimbabwean economy, a non-linear NARDL modelling approach will be employed. This methodology will estimate the projected non-linear co-integrating association between positive and negative shocks to DFIs funding and investment. The data set consisted of projected annual macroeconomic variables for Zimbabwe obtained from world bank and IMF. Results - In the short run, it was found that both positive and negative shocks influence future investment, with negative shocks expected to have a larger effect. These negative shocks arise from economic downturns or external shocks, while positive shocks could result from increased funding or favourable policy changes. In the long run, it was found that positive shocks to DFIs funding have a positive impact on investment, leading to increased economic growth and development. Conclusion and Recommendations - Based on the results, DFIs funding should exhibit an asymmetric relationship with investment in Zimbabwe. It is crucial for the government of Zimbabwe to proactively plan for these anticipated asymmetric effects and develop strategies to maximize the benefits of DFIs funding. By implementing the recommendations, Zimbabwe can be able to ensure a more favourable environment for future DFIs funding, fostering sustainable investment and economic growth.

Innovation for a greener future: Disentangling the asymmetric impact of green finance on green technology in european union economies

Green finance has originated as a critical factor for green development, where green technology innovation is a primary approach. Yet, limited information is available regarding how green finance influences green technological creation. This work probes the asymmetric linkage between green finance and green technology innovation in the selected European Union countries (Germany, Sweden, France, Italy, Netherlands, Spain, Denmark, Norway, Belgium, and Finland). Prior works adopted panel data methods to get usual outcomes concerning the green finance-green technology nexus, nevertheless the reality is that various nations did not establish such connection separately. The present work, in contrast, utilizes a peculiar tool, 'Quantile-on-Quantile,' that facilitates research to probe temporal reliance in entire nations by giving global yet economy-specific intuitions on the variables’ correlation. Estimates exhibit that green finance enhances green technology innovation in almost all our chosen nations at definite quantiles of data distribution. Furthermore, the findings expose that the extent of asymmetry throughout various quantiles of our variables differs by the economy, emphasising the relevance of policymakers paying particular consideration while employing green innovation and green finance policies.

Impact of carbon pricing on comparative advantage in environmental goods export in sub‐Saharan Africa: Evidence of asymmetries from South Africa

AbstractThis paper examines the asymmetric link between carbon pricing and the comparative advantage in environmental goods exports in South Africa from 1995 to 2021. The non‐linear autoregressive distributed lag model is utilized to investigate the effects of both minor and major positive and negative fluctuations in carbon taxes, technological innovation, and energy transition on comparative advantage. The results reveal that carbon taxes have an asymmetric effect on comparative advantage in both the short and long runs, with positive shocks exerting a greater beneficial influence than negative shocks. Specifically, it is found that a 1% reduction in carbon taxes corresponds to a 1.24% decline in the response variable, whereas a 1% increase in carbon taxes is associated with a 2.72% increase in comparative advantage in environmental goods exports, which is twice as large. The study also uncovers evidence of an asymmetric relationship between low‐carbon technological innovation and comparative advantage in environmental goods exports. However, strong evidence of a long‐run asymmetric linkage between the energy transition and comparative advantage is not established. Nevertheless, it is noteworthy that a positive shift in energy transition is linked with a 0.32% rise in comparative advantage in environmental goods exports, whereas a negative shift in energy transition corresponds to a 0.11% decrease. The practical policy implications are also discussed.

PyPop: a mature open-source software pipeline for population genomics.

Python for Population Genomics (PyPop) is a software package that processes genotype and allele data and performs large-scale population genetic analyses on highly polymorphic multi-locus genotype data. In particular, PyPop tests data conformity to Hardy-Weinberg equilibrium expectations, performs Ewens-Watterson tests for selection, estimates haplotype frequencies, measures linkage disequilibrium, and tests significance. Standardized means of performing these tests is key for contemporary studies of evolutionary biology and population genetics, and these tests are central to genetic studies of disease association as well. Here, we present PyPop 1.0.0, a new major release of the package, which implements new features using the more robust infrastructure of GitHub, and is distributed via the industry-standard Python Package Index. New features include implementation of the asymmetric linkage disequilibrium measures and, of particular interest to the immunogenetics research communities, support for modern nomenclature, including colon-delimited allele names, and improvements to meta-analysis features for aggregating outputs for multiple populations. Code available at: https://zenodo.org/records/10080668 and https://github.com/alexlancaster/pypop.

On the linkage of oil prices and oil uncertainty with US equities: a combination analysis based on the wavelet approach and quantile-on-quantile regression

This paper aims to investigate the dynamic and asymmetric linkage between crude oil, oil uncertainty, and the United States (US) equity markets across various horizons and tails using a combination of a time-frequency approach, Granger causality, and quantile-on-quantile regression from January 2020 to December 2022. The empirical results indicate that causal relationships and the dynamic co-movement between crude oil, oil implied volatility, and the Dow Jones industrial and transportation indices are confirmed across various frequencies through wavelet-based Granger causality and wavelet coherence. Then, the wavelet-based quantile-on-quantile regression shows that the relationship between oil, oil implied volatility, and both US equity markets is heterogeneous and asymmetric across short- and long-run horizons, in particular. The findings provide new insights into the sensitivity of US stock markets to oil shocks across various time frequencies and tails, offering several portfolio implications useful for heterogeneous investors and portfolio managers.

Asymmetric and time-frequency co-movements among innovation-themed investments and carbon emission efficiency: Thematic investing and hedging opportunities.

This study is aimed at investigating the asymmetric and time-frequency co-movements and the hedge or safe-haven properties of carbon efficient indices, the MSCI ACWI Sustainable Impact, and MSCI World EGS indices, in relation to technology and innovation-themed investments. In doing so, the ADCC-GJR-GARCH and wavelet coherence techniques are applied to a daily return series ranging from January 2019 to January 2023. Findings of the ADCC-GJR-GARCH model show negative and insignificant asymmetric linkage among underlying indices during the sample period. The S&P 500 carbon efficient index (CEI) acts as a strong hedge or safe-haven for technology and innovation-themed indices during tranquil and tumultuous periods. The MSCI ACWI Sustainable Impact, MSCI World EGS, and carbon efficient indices except for S&P 500 CEI exhibit weak hedge or safe-haven attributes. Wavelet coherence reveals negative (positive) co-movements between the thematic and carbon efficient indices in short-term (medium-term and long-term) horizons with consistent leading behavior of thematic indices to carbon efficient indices outcomes. It justifies the presence of short-lived hedging or safe-haven characteristics in the thematic domain for investors. These strong and weak hedge or safe-haven characteristics of low carbon and sustainability indices reveal that adding low carbon efficient and sustainable investments to a portfolio result in considerable diversification benefits for investors who tend to take minimal risk in both tranquil and tumultuous periods. The current findings imply that financial institutions, thematic investing companies, and governments need to encourage carbon efficient technology transfer and innovation-themed investments by increasing the fund allocations in underlying asset classes. Policy-making and regulatory bodies can encourage investors to make carbon-efficient and thematic investments and companies to issue carbon-efficient stocks or investments to safeguard social and economic risks during fragile periods. These investments can offer greater opportunities to combat the intensity of economic shocks on portfolios for responsible or sustainable investors.

The systemic risk-uncertainty-real economic activity nexus: What is beyond median estimation?

The paper investigates the lead-lag relationships among systemic risk, economic uncertainty and real economic activity for top-5 contributors to global systemic risk, the USA, China, the UK, France and Japan, during January 2010-July 2023. By decomposing these variables into a below- and above-the-median components and applying VAR models to them, we confirm the presence of asymmetric relationships among systemic risk, economic uncertainty and real economic activity. Most of these asymmetric linkages are found for the USA, followed by the UK and China.

Asymmetric linkages among fintech, oil prices, governance, and growth in Southeast Asian economies

Fintech's disruptive potential in Southeast Asia can revolutionize financial inclusion and accelerate economic growth, warranting a comprehensive analysis of its interplay with oil prices, governance, and overall economic development. Against this backdrop, this study analyze the quantile-dependent (asymmetric) influence of oil prices, cumulative financial technology index, and institutional quality on economic growth for selected Southeast Asian countries from 1996 to 2021. Method of Moments Quantile Regression (MMQR) is used to analyse the asymmetric relationship, while the Dumitrescu-Hurlin Panel Causality test applies to the intrinsic casualty. The study's outcomes exposed the positive (negative) influence of Fintech and governance (oil prices); however, there marginal impact substantially varies at lower a higher growth quantiles. Labor headcount and capital stocks are among the main contributor of economic growth, specifically at higher growth quantiles (countries). Bi-directional causality has been confirmed through Dumitrescu-Hurlin Panel Causality test between Fintech, oil prices and governance with economic growth. Therefore, Generalized Method of Moment and Augmented Mean Group is further applied for robustness. After controlling reverse causality and endogeneity issues, the prior outcomes are validated. These findings offer valuable outcomes.

Intercity asymmetrical linkages influenced by Spring Festival migration and its multivariate distance determinants: a case study of the Yangtze River Delta Region in China

Understanding intercity linkage patterns is of great importance to understanding urbanization. With advancements in transportation, communication technology, and the availability of big data, the “death of distance” concept has gained significant attention. This paper analyzes the asymmetric spatial intercity linkage network in China’s economically developed YRDR based on big data derived from Spring Festival (SF) migration. The aim is to explore the determinants of these linkages considering multivariate distance factors. The findings indicate a notable pattern of asymmetry in the intercity linkage network of the YRDR between core and non-core cities. The spatial decay effect of geographic distance on intercity asymmetry linkage is observed. Despite technological advancements, geographic distance remains the most influential and decisive factor in determining intercity asymmetric linkages. While other attribute distances also play a positive role, their effects become complex when controlling for geographic distance. Understanding these attribute distances is essential in comprehending the decay effect. This study contributes to the empirical investigation of the “death of distance” debate and provides a practical analytical framework for analyzing the drivers of intercity linkage patterns. It enhances our understanding of intercity spatial linkages within the context of urbanization in China and offers valuable insights for formulating development policies in the YRDR.

Assessing the asymmetric influence of ICT on the tourism development: fresh insights from a tourist destination economy

ABSTRACT The United Nations’ ‘Sustainable Development Goals (SDGs)’ recommended seventeen viable strategies aimed at eradicating poverty, maintaining the quality of the natural environment, and assuring everyone's prosperity. Travel and tourism are the primary stream segments by which all three of the above-mentioned United Nations agendas may be effectively addressed. However, India's long-term vision is also in accordance with the SDGs, which place considerable attention on tourism expansion, invention, and sustainable development through the ‘information and communication technology (ICT)’ renaissance. In this milieu, considering annual data from 1990 to 2017, this research aims to examine the asymmetric linkage between tourism (no. of tourist arrivals), ICT (ratio of the population using the internet), and economic growth in India. We employed the ‘non-linear autoregressive distributed lag (NARDL)’ bounds approach to explore the asymmetric cointegration among the drivers under investigation and confirmed long-run cointegration. Results from NARDL elicited that a positive shock in the partial sum of ICT dwindles tourist arrivals, whereas a negative shock to the ICT fosters tourist visits in the long run. Furthermore, it seems that the expansion of the Indian tourist industry is positively correlated with economic growth. The single Fourier Frequency Granger causality test revealed ICT and Tourist Arrivals (TA), and GDP and TA have a feedback loop.

Chain-Kinked Design: Improving Stretchability of Polymer Semiconductors through Nonlinear Conjugated Linkers.

The manipulation of the polymer backbone structure has a profound influence on the crystalline behavior and charge transport characteristics of polymers. These strategies are commonly employed to optimize the performance of stretchable polymer semiconductors. However, a universal method that can be applied to conjugated polymers with different donor-acceptor combinations is still lacking. In this study, we propose a universal strategy to boost the stretchability of polymers by incorporating the nonlinear conjugated linker (NCL) into the main chain. Specifically, we incorporate meta-dibromobenzene (MB), characterized by its asymmetric linkage sites, as the NCL into the backbone of diketopyrrolopyrrole-thiophene-based (DPP-based) polymers. Our research demonstrates that the introduction of MB prompts chain-kinking, thereby disrupting the linearity and central symmetry of the DPP conjugated backbone. This modification reshapes the polymer conformation, decreasing the radius of gyration and broadening the free volume, which consequently adjusts the level of crystallinity, leading to a considerable increase in the stretchability of the polymer. Importantly, this method increases stretchability without compromising mobility and exhibits broad applicability across a wide range of donor-acceptor pair polymers. Leveraging this strategy, fully stretchable transistors were fabricated using a DPP polymer that incorporates 10 mol % of MB. These transistors display a mobility of approximately 0.5 cm2 V-1 s-1 and prove remarkably durable, maintaining 90% of this mobility even after enduring 1000 cycles at 25% strain. Overall, we propose a method to systematically control the main-chain conformation, thereby enhancing the stretchability of conjugated polymers in a widely applicable manner.

Evidence of the internationalization of China's crude oil futures: Asymmetric linkages to global financial risks

Since its launch, China's crude oil futures (COIL) have gradually integrated with the international financial market but undoubtedly face more risks. For the purpose of exploring the influence mechanism between COIL and global risk, this paper uses a series of Granger causality tests to provide more evidence of COIL internationalization. In addition, we focus on exploring whether this influence mechanism has asymmetric characteristics. We choose a comprehensive new indicator, the Global Financial Risk Index (COVOL), to represent global financial risk, and also pay attention to three kinds of global risk refer to international energy, inflation, and financial system uncertainty. First, we find a marked asymmetry in the impact of global risks on COIL, especially energy-related risks, followed by financial system uncertainty. Second, COIL also has a significant asymmetric impact on global financial risks, including COVOL, GOIL, FSI, and EPU. Next, we further explore long-term and short-term changes in these asymmetric relationships. Empirical results have found that most asymmetric patterns exhibit long-term characteristics. Finally, given the potential impact of global extreme events, we provide an in-depth analysis of whether this asymmetric link still holds after the COVID-19 outbreak and the Russia-Ukraine conflict. These findings may provide important implications for improving coil market policy and related investment decisions.

Poverty and financial development: an asymmetric and nonlinear ARDL analysis for India

PurposeThe primary objective of the paper is to examine the asymmetric Cointegration and asymmetric causality between financial development and poverty alleviation on annual data in Indian context over the period from 1980 to 2019.Design/methodology/approachFirst nonlinearity test by Brooks et al. (1999) is applied to ascertain the nonlinear behavior of the variables used. Once the nonlinear behavior of variables is confirmed, asymmetric and nonlinear unit root tests by Kapetanios and Shin (2008) are applied to check for the order of integration of selected variables. Next, nonlinear autoregressive distributed lag model (NARDL) is employed to analyze the asymmetric Cointegration. Finally, Hatemi-j- asymmetric causality tests is applied to work out the direction of asymmetric causality.FindingsThe empirical findings document the existence of asymmetries in the short-run as well as long-run between poverty and financial development. The asymmetry reveals that negative financial development shocks leave a more profound impact on poverty alleviation than their positive equivalents. The findings of Wald's test also confirm the presence of asymmetric Cointegration. The asymmetric cumulative dynamic multipliers used to examine the behavior of asymmetries and adjustments with respect to time lend credence to the results calculated using NARDL estimator. This result exhibits the robustness of the model. Furthermore, the result emanating from recently introduced asymmetric causality test reveals a unidirectional asymmetric causality between negative shocks in financial development and poverty. The findings of the present study necessitate the need for investigating asymmetric and nonlinear effects in finance–poverty nexus, which existent literature has completely neglected, in order to have relevant policy conclusions.Research limitations/implicationsThe study used “Per capita consumption expenditure” as a measure for poverty due to lack of continuous time series data on headcount ratio. In future, researchers can extend this study by incorporating headcount ratio as a measure of poverty in their respective works. There is further scope of research on this issue by finding out the impact of formal and informal sources of credit on poverty separately. A panel data study for developing countries over a period of time could further confirm/negate the findings of the present study.Originality/valueTo the best of the authors’ knowledge none of the studies in Indian context has scrutinized asymmetric and nonlinear impact of financial development on poverty. To dredge up asymmetric structures at work, the authors have used the highly celebrated NARDL estimator. To enrich the existent body of knowledge along the lines of asymmetric (nonlinear) linkages, the authors have also used recently introduced asymmetric causality test by Hatemi-j-(2012) to find out the direction asymmetric causality.

Charting a Sustainable Future: The Impact of Economic Policy, Environmental Taxation, Innovation, and Natural Resources on Clean Energy Consumption

Energy availability especially that derived from renewable sources has sustainable effects on economic progress and environmental rectifications. However, using clean energy in the energy mix has been influenced by several macro fundamentals. The motivation of this study is to gauge the impact of uncertainties, environmental restrictions and innovation on clean energy consumption for the period 1997–2021 by employing the new econometric estimation techniques commonly known as CUP-FM and CUP-BC. Referring to the preliminary assessment with the slope of homogeneity, cross-sectional dependency and panel cointegration test, it is unveiled that research variables have exposed heterogeneity prosperities, cross-sectional dependence, and long-run association in the empirical equation. According to the empirical model output with CUP-FM and CUP-BC, EPU has a native statistically significant connection to clean energy consumption. At the same time, environmental taxation and technological innovation have had beneficial effects on clean energy development. Additionally, the nonlinear estimation disclosed asymmetric linkage between explanatory and explained variables in the long and short run. Directional causality revealed a feedback hypothesis explaining the relationship between EPU, TI and clean energy consumption. The study has offered policy suggestions based on the findings for future development.

O27 A web-based visualization tool for asymmetric linkage disequilibrium (ALD) between amino acid positions of classical HLA loci in US populations

O27 A web-based visualization tool for asymmetric linkage disequilibrium (ALD) between amino acid positions of classical HLA loci in US populations

The asymmetric nexus of energy-growth and CO2 emissions: An empirical evidence based on hidden cointegration analysis

Noting the significance of asymmetries in macroeconomic literature, this study aimed to estimate the asymmetric linkages between energy growth and the environment for BRICST countries between 1990 & 2017. For this purpose, this study applied hidden cointegration, panel NARDL, and asymmetric causality tests between the variables. In the first step, the results supported the existence of hidden cointegration between the variables. In the next step, empirical results obtained from panel NARDL results explained that the chosen variables have asymmetric relationships and are highly responsive to macroeconomic shocks. Initially, the positive shocks of energy consumption positively respond to environmental degradation; similarly, the negative shocks also correspond positively to CO2 emissions. In the economic expansion phase, the positive shocks of growth have insignificant, and adverse shocks negatively respond to CO2 emissions in BRICST countries. The results of individual countries along BRICST differ at various levels in response to asymmetric shocks. Different asymmetric causalities between the chosen dimension of variables are explored. From the asymmetric associations between the variables, the study proposes to forecast the energy demand and explore alternative ways to energy resources to shift their fossil energy bases to renewable systems. Similarly, adopting ICT products could make energy efficiency in these countries more productive towards improving environmental quality.

Exploring Asymmetric Linkages and Volatility Transmission between Stock Market and Foreign Exchange (FOREX)

This study examines the direction and nature of volatility transmission between the stock market and the foreign exchange market (FOREX) of Pakistan. For this purpose, daily data is gathered to conduct the analysis for both markets. Stock market returns are measured by using the KSE-100 index and the daily Pakistan Rupee-PKR to the United States Dollar-USD exchange rate is used for the foreign exchange market. Noticeably, both the variables are stationary at their first difference. Normality is examined through Skewness and Kurtosis, Autocorrelation through Correlogram Q-statistics, and the ARCH effect through the ARCH-LM test. Volatility transmission between the two markets is examined by using bivariate diagonal BEKK-GARCH and bivariate E-GARCH models. The results of the study indicate that bi-directional volatility transmission exists between the stock market and the foreign exchange market (FOREX) of Pakistan. Results from the E-GARCH model further indicate that the nature of volatility transmission between these two markets is asymmetric, which means bad news of one market has a greater impact on the volatility of another market than the good news. Hence, the results of this study also indicate that past variances of the stock market and foreign exchange market has a significant effect on their own current volatility.

Realized semi variance quantile connectedness between oil prices and stock market: Spillover from Russian-Ukraine clash

This study aims to investigate the dynamic relationship between oil prices and stock markets in the G5+ countries using Parkinson's proximal realized volatility. We separate positive and negative semi-variance to compute asymmetric aggregate static spillovers according to the Diebold and Yilmaz (DY) approach. Moreover, we use a Quantile VAR to investigate the behavior of series in different quantiles corresponding to different market scenarios. Consistently with the literature concerns, we use a daily sample of market indices prices with the Brent oil price from June 1, 2017, to July 2, 2022. We found an asymmetric linkage between oil prices and the stock market, which has significant implications for portfolio hedging strategies. Specifically, our research indicates that the impact of the Russian-Ukrainian conflict on the energy crisis has been significantly higher than that of the COVID-19 pandemic, especially in the short term. However, we observe a higher persistence of negative spillovers for COVID-19 compared to those recorded during the Russia-Ukraine war. From a methodological viewpoint, this result enforces the choice of an asymmetric model to investigate the volatility transmission between financial market series. Finally, we found crude oil to emit volatility spillovers in quantiles above 80%. This result emphasizes the instability perceived in crude oil price when general market volatility increase. Quite the opposite, about one-third of oil price shocks, are linked to the national stock exchange uncertainty in low and middle quantiles, underlining the investors' dependency on this commodity. These results have important implications for policymakers and institutional authorities, who must consider the changing macroeconomic environment and reduce dependence on Russian energy.