Dynamic Linkages Research Articles

Persistence in financial connectedness and systemic risk

This paper characterizes dynamic linkages arising from shocks with heterogeneous degrees of persistence. Using frequency domain techniques, we introduce measures that identify smoothly varying links of a transitory and persistent nature. Our approach allows us to test for statistical differences in such dynamic links. We document substantial differences in transitory and persistent linkages among US financial industry volatilities, argue that they track heterogeneously persistent sources of systemic risk, and thus may serve as a useful tool for market participants.

Re-examining asymmetric dynamics in the relationship between macroeconomic variables and stock market indices: empirical evidence from Malaysia

PurposeThe aim of this research is to re-examine the dynamic linkages between macroeconomic variables and the stock market indices in Malaysia following some transformational changes in the policies and the exchange rate regime.Design/methodology/approachUsing monthly data points for all the economic variables and the stock market index (KLCI Index), the authors applied vector autoregression (VAR) model to examine the relationship. The authors also used impulse response function (IRF) in order to explore the effect of one-unit shock in “X” on “Y” under the VAR environment.FindingsThe authors' study finds a significant relationship between all the macroeconomic variables and the stock market index of Malaysia. The cointegration results indicate a long-term relationship, whereas the vector autoregressive-based impulse response analysis suggests that the Malaysian stock index (KLCI) responds negatively to the money supply, inflation and producer price index (PPI). However, the authors' results indicate a positive response from the stock index to the exchange rate.Research limitations/implicationsThe authors' study's results are based on selected macroeconomic variables and the VAR model. Researchers may find other variables and methods more useful and may provide findings accordingly.Practical implicationsSince the results are quite asymmetric, it would be interesting for the market players, policymakers and regulators to consider the findings and explore appropriate opportunities.Originality/valueWhile the relationship between macroeconomic variables and stock market indices has been widely examined, a significant gap in the literature remains concerning the role of exchange rate variable on the stock market in an emerging economy context.

Chemical conversion of imine- into quinoline-linked covalent organic frameworks for photocatalytic oxidation

Post-synthetic modification is an important strategy for improving and enhancing the properties and functions of covalent organic frameworks (COFs). Two imine-linked COFs are converted into the quinolone-linked COFs by converting the dynamic imine linkages in the COFs into more robust quinolone ring via aza-Diels-Alder cycloaddition reaction. The prepared quinolone-linked COFs not only maintain good crystallinity and porosity, but also possess expanded conjugate planes, enhanced light absorption and excellent stability. The quinolone-linked COFs present remarkable performance of photocatalytic oxidation reactions, including oxidation of phenylboric acids, coupling of benzylamine, and oxidation of thioethers. This work is helpful for preparing organic porous photocatalytic materials with high performance and long life.

Dynamic financial and monetary security risk assessment based on information service security assessment model and blockchain

With the rapid development of blockchain technology, the financial and monetary (FM) blockchain fields also began to collide. Therefore, this study aims to explore the relationship between the two fields and efficiently evaluate the security of financial information. Firstly, this study introduces the theoretical basis of blockchain in the dynamic linkage mechanism of FM and gives the overall framework of digital currency based on blockchain. Meanwhile, the relationship between blockchain and digital finance is empirically analyzed and designed. Secondly, the framework of financial information service security assessment (ISSA) is created using blockchain technology, and the frame of security risk evaluation is verified by taking electronic invoice information as the research object. Finally, the results show that: (1) foreign exchange (forex) events and major stock index decline events have a significant impact on the return of Bitcoin (BTC) in the short term. Moreover, more than 70% of uncertainty events will make BTC’s abnormal return (AR) significantly positive; (2) Under the influence of forex uncertainty events, only one BTC’s AR is remarkably negative in short order, while the other seven times are markedly positive. In the uncertainty events of major stock indexes, only two times are significantly negative, and the other six times are positive. This indicates that uncertain events in the short run make prominent AR of BTC; the proposed blockchain-based ISSA model and assessment index are scientific, feasible, and operable.

A Study on the Interrelationship between the Stock Markets and the Foreign Exchange Market in India

This study aims at examining the short-run and long-run dynamic linkages among exchange rates and stock market index in India through a structured cointegration and Granger causality tests. Daily exchange rates of USD, EUR, JPY, and GBP to INR along with the daily movement of NSE NIFTY and BSE SENSEX for a period spanning 20 years from 1 January 2003 to 23 November 2022 were used for the analysis. The results reveal that there is no evidence for a stable long-run relationship between stock market index and the exchange rates under study. However, the VAR-based Granger causality test shows that USD and EURO have short-run causal relationship with NSE NIFTY and BSE SENSEX. The NSE NIFTY and BSE SENSEX also seemed to have an influence on USD and JPY expressed in terms of Indian rupee.

Modelling Dynamic Linkage between Climate Change and Food Inflation in Nigeria

The study delves into the critical issue of climate change and its detrimental impact on various regions worldwide, including Nigeria. It emphasizes the urgent need for global efforts to mitigate these effects and advocates for measures to address human activities contributing to climate dynamics. Specifically, the study empirically examines the affiliation between climate change shocks and food price inflation in Nigeria using a Nonlinear Autoregressive Distributed Lag (NARDL) approach. The dataset covers the period from January 2011 to December 2022.The empirical findings reveal a robust cointegrating relationship between climate change shocks and food price inflation in Nigeria. Notably, climate change shocks significantly contributed to rising food prices within the study period. Furthermore, the Error Correction Term (ECT), estimated at 52 percent, indicates that food price inflation adjusts by 52 percent in the current month to counteract the initial shock experienced in the previous month. The Dynamic Multiplier graph, along with a 95 percent confidence interval, demonstrates that the explanatory variables exert substantial influence on food price inflation in Nigeria during the study period. Considering these findings, the study recommends that Nigeria should transit from traditional agricultural practices to Climate-Smart Agriculture to address future needs and climate-related challenges. Additionally, the government and stakeholders should implement alternative practices such as irrigation and the replenishment of shrinking water bodies in the Sudan and Sahel savannah regions.

A qualitative analysis of health information-sharing networks in the Indonesian poultry sector.

Animal production systems are developing into increasingly complex value chains involving a large diversity of actors with multiple and dynamic linkages, concurrently creating many opportunities for disease spread. Access to timely and good-quality animal health information is vital for designing effective disease management strategies. However, several factors may hamper information flows along those chains. Understanding the structure and dynamics of information networks is essential to develop effective and acceptable health information systems. We applied a qualitative network approach to understand how information about poultry health is generated, disseminated and used for decision-making along the poultry value chain in Indonesia. Maps of the value chain and information networks were generated based on data from key informant interviews to illustrate the linkages and information-sharing patterns between stakeholders. Four types of farm business models were identified: company-owned, contract, partnership and independent. Although companies and most independent farmers collected health and production data routinely, their systems were strongly siloed and still relied on a mix of digital and paper-based methods, which impaired their analytical capacity. Technical service providers from the upstream sector and industry associations were identified as key intermediaries in the information-sharing network with the ability to create informal bridges between separate business networks and public actors. These actors can play a strategic role in the development of integrated information systems to improve stakeholders' capacity to monitor, anticipate and manage disease threats at all levels of the value chain. This study contributes to fill an important knowledge gap regarding the layer sector and may help decision-makers to design effective policies and interventions tailored to the type of business model.

High-accuracy torque estimation and safety control for induction motor used in electric vehicles

As a power output unit, Induction Motor (IM) is widely used in Electric Vehicles (EV) due to its unique advantages of higher power density and better torque ability. With more complicated motor controller system, there are some hardware and software failures which bring some risks including EV unexpected acceleration or deceleration, therefore it is necessary to build high-accuracy torque estimation and safety control strategy. Firstly, hazard and safety concept are analyzed to make sure function safety goals and levels for IM system. Secondly, a novel method of high-accuracy torque estimation is proposed based on a rotor dynamic and composite flux linkage observer. Then, fault diagnosis and handling mechanisms of motor torque are designed to avoid hazards when it is a significant difference between motor estimation torque and vehicle requested torque. Finally, power test and Hardware in Loop (HIL) bench are configured to verify torque estimation accuracy and fault protection mechanisms rationality by comparing test results and injecting related faults. Experiment result shows that motor torque accuracy is within ±5 Nm and fault protection mechanisms can bring motor to safety state promptly.

Influence of the Tibetan Plateau on the coupling of the North Pacific–North Atlantic pressure systems

The Tibetan Plateau (TP) exerts a profound influence on global climate change. In the boreal winter, the TP has a notable impact on the Asian winter monsoon. Nevertheless, the relationship between the TP and the climate of the remote Arctic region is not yet fully understood. The North Pacific and North Atlantic pressure systems exhibit dynamic linkages through the Aleutian Low–Icelandic Low seesaw in the boreal winter season. However, the extent to which large mountains, such as those in the TP, influence this coupling remains unclear. In this study, we conducted an orographically sensitive experiment using the Whole Atmosphere Community Climate Model Version 6. The results obtained from the model indicate that the TP influences Arctic pressure anomalies specifically via the modulation of the Aleutian Low–Icelandic Low seesaw. Specifically, the TP favors the eastward extension of a pattern resembling the Pacific–North American pattern, achieved by enhancing the horizontally propagating wave trains originating from the eastern Pacific, thus establishing a clear Aleutian Low–Icelandic Low seesaw. In addition, the TP was a critical factor in the stratosphere–troposphere coupling as it facilitated the shift of the stratospheric polar vortex towards Eurasia in a poleward direction, potentially leading to the extension of the wave train emanating from the North Pacific across North America. These results suggest that the TP significantly contributes to Arctic climate variability. This influence is observed via the TP-mediated modulation of the teleconnection between the North Pacific and North Atlantic regions and stratosphere–troposphere coupling.

A robust and efficiently reprocessable poly(dimethylsiloxane) elastomers enhanced by self‐catalysis Zn(II)‐ligand bonds and silyl ethers

AbstractIn recent years, as an emerging dynamic bonding, silyl ether linkages have been concerned and applied. However, the reprocessability of vitrimers based on it is far from satisfactory because of the inactive dynamic exchange reaction. At the same time, the mechanical properties of polysiloxane elastomers are poor because of the high flexibility of polysiloxane molecular chains and weak intermolecular forces. Herein, we have successfully synthesized a PDMS elastomer incorporating Zn(II)‐amine coordination bonds as sacrificial units, which are crosslinked through dynamic silyl ether linkages. Importantly, the presence of Zn ions promotes the exchange between the silyl ether linkages and hydroxyl groups. The elastomers exhibited excellent mechanical properties (35 times improvement in toughness) and outstanding reprocessability. The mechanical property recovery of the PDMS elastomers reached approximately 90% after four reprocessing cycles. Meanwhile, small‐molecule simulation experiments were conducted to verify the significant catalytic effect of Zn (II) ions as Lewis acid catalysts on the exchange reaction of silyl ether linkages and hydroxyl groups. In a word, this work provides a facile strategy to simultaneously enhance the mechanical properties and reprocessing performance of silyl ether‐linked polysiloxane elastomers.

High-Throughput Sequencing Reveals a Dynamic Bacterial Linkage between the Captive White Rhinoceros and Its Environment.

Soil is an essential part of the animal habitat and has a large diversity of microbiota, while the animal body was colonized by a complex bacterial community; so far, the relationship between the animal host microbial community and the soil microbial ecosystem remains largely unknown. In this study, 15 white rhinoceros from three different captive grounds were selected and the bacterial community of the gut, skin, and environment of these rhinoceros were analyzed by 16S rRNA sequencing technology. Our results showed that Firmicutes and Bacteroidota were the predominant phyla in the gut microbiome, whereas skin and environment samples share similar microbiome profiles and are dominated by the phyla of Actinobacteriota, Chloroflexi, and Proteobacteria. Although the bacterial composition of the gut differs from that of the skin and environment, the Venn diagrams showed that there were 22 phyla and 186 genera shared by all the gut, skin, and environmental microbes in white rhinoceroses. Further cooccurrence network analysis indicated a bacterial linkage based on a complex interaction was established by the bacterial communities from the three different niches. In addition, beta diversity and bacterial composition analysis showed that both the captive ground and host ages induced shifts in the microbial composition of white rhinoceroses, which suggested that the bacterial linkage between the captive white rhinoceros and its environment is dynamic. Overall, our data contribute to a better understanding of the bacterial community of the captive white rhinoceros, especially for the relationship between the environment and animal bacterial communities. IMPORTANCE The white rhinoceros is one of the world's most endangered mammals. The microbial population plays a key role in animal health and welfare; however, studies regarding the microbial communities of the white rhinoceros are relatively limited. As the white rhinoceros has a common behavior of mud baths and thus is in direct contact with the environment, a relationship between the animal microbial community and the soil microbial ecosystem appears possible, but it remains unclear. Here, we described the characteristics and interaction of bacterial communities of the white rhinoceros in three different niches, including gut, skin, and environment. We also analyzed the effects of captive ground and age on the composition of the bacterial community. Our findings highlighted the relationship among the three niches and may have important implications for the conservation and management of this threatened species.

Dynamic and functional linkage between von Willebrand factor and ADAMTS-13 with aging: an Atherosclerosis Risk in Community study

Backgroundvon Willebrand factor (VWF) is a multimeric glycoprotein critically involved in hemostasis, thrombosis, and inflammation. VWF function is regulated by its antigen levels, multimeric structures, and the state of enzymatic cleavage. Population studies in the past have focused almost exclusively on VWF antigen levels in cross-sectional study designs. ObjectiveTo identify subjects in the Atherosclerosis Risk in Community study who had persistently low and high VWF antigen over 10 years and to quantify longitudinal changes in the biological activities and cleavage of VWF in these subjects. MethodsWe measured VWF antigen, propeptide, adhesive activities, and cleavage by ADAMTS-13 quantified using a mass spectrometry method that detected the cleaved VWF peptide EQAPNLVY, as well as coagulation factor VIII activity. ResultsWe determined the mean subject-specific increase in VWF to be 22.0 International Units (IU)/dL over 10 years, with 95% between -0.3 and 59.7 IU/dL. This aging-related increase was also detected in VWF propeptide levels, ristocetin cofactor activity, and VWF binding to collagen. We identified 4.1% and 25.0% of subjects as having persistently low (<50 IU/dL) and high (>200 IU/dL) VWF antigen, respectively. Subjects with persistently low VWF had enhanced ristocetin cofactor activity, whereas those with persistently high VWF had elevated levels of ADAMTS-13, resulting in a comparable rate of VWF cleavage between the 2 groups. ConclusionsThese results provide new information about the effects of aging on VWF antigens and adhesive activity and identify a functional coordination between VWF and the rate of its cleavage by ADAMTS-13.

Understanding groundwater storage and drainage dynamics of a high mountain catchment with complex geology using a semi-distributed process-based modelling approach

Mountainous groundwater systems are usually characterized by great geological complexity and highly heterogeneous hydraulic properties. For that reason, proper system characterization, monitoring and modelling remain challenging. In this study, we investigated a geologically complex alpine catchment (from 1400 to 2900 m asl) in the Dolomites (Italian Alps) by combining hydrogeological field investigation, hydrological monitoring and modelling. A semi-distributed process-based hydrological model was applied to simulate the continuous measured catchment discharge in a period of three years, which covers a large variation of hydrodynamic conditions. The model structure couples the sequential hydrogeological units within the studied catchment: (1) the fractured dolomitic rocks as bedrock aquifer and 2) the unconsolidated deposits accumulating on the slopes and at the valley floor as porous aquifer. In order to evaluate the model structure and parameterization in depth, we applied a multi-step evaluation approach considering both parameter sensitivity and uncertainty. The modelling results demonstrate that the newly developed model can reproduce most discharge behavior of aquifers. The model indicates a seasonal dynamic linkage between surface and subsurface storage units during different flow conditions. Besides the matrix and conduit flow in fractured dolomitic aquifer, it highlights the important role of unconsolidated sediments (porous aquifer) to the storage and discharge behavior of the entire groundwater system. Furthermore, with the comprehensive model evaluation we learned the model performance deficit during extreme high flow conditions and proposed a more detailed hydrogeological conceptual model. We believe that the proposed modelling approach can be transferred to other high mountain catchments with similar hydro(geo)logical characteristics to characterize the collective behavior of aquifer systems, explore conceptual model weakness and optimize catchment monitoring work.

Dynamic linkages between real exchange rates and real unit labour costs: evidence from 18 economies

ABSTRACT The article examines the long-run behaviour of real exchange rates based on the premises of classical political economy. Specifically, it investigates the dynamics between real exchange rates and real unit labour costs of tradable commodities for 18 developed and developing economies. The analysis is carried out by applying recent methods of panel data, while the short- and long-run dynamics are estimated based on the cross-sectional autoregressive distributed lag model. Our findings confirm the presence of short- and long-run effects of real unit labour costs on real exchange rates. Consequently, new and more effective foreign exchange rate policies may be designed.

Dynamic linkage between oil shocks and economic growth: New evidence from Alaska

The long- and short-run impacts of oil supply and demand shocks on economic growth are investigated for Alaska. The responses to positive and negative oil shocks are allowed to be asymmetric. The structural VAR as well as ARDL/NARDL techniques are considered. We discover that oil supply and demand shocks are significant forces affecting Alaska’s growth in the short run, but not in the long run. We also reveal no evidence of asymmetric effects in both the short and long run.

Large-Scale Synthesis of Covalent Organic Frameworks: Challenges and Opportunities.

Connecting organic building blocks by covalent bonds to design porous crystalline networks has led to covalent organic frameworks (COFs), consequently transferring the flexibility of dynamic linkages from discrete architectures to extended structures. By virtue of the library of organic building blocks and the diversity of dynamic linkages and topologies, COFs have emerged as a novel field of organic materials that propose a platform for tailor-made complex structural design. Progress over the past two decades in the design, synthesis, and functional exploration of COFs in diverse applications successively established these frameworks in materials chemistry. The large-scale synthesis of COFs with uniform structures and properties is of profound importance for commercialization and industrial applications; however, this is in its infancy at present. An innovative designing and synthetic approaches have paved novel ways to address future hurdles. This review article highlights the fundamental of COFs, including designing principles, coupling reactions, topologies, structural diversity, synthetic strategies, characterization, growth mechanism, and activation aspects of COFs. Finally, the major challenges and future trends for large-scale COF fabrication are outlined.

Adhesive injectable cellulose-based hydrogels with rapid self-healing and sustained drug release capability for promoting wound healing

Injectable biocompatible hydrogels with multiple functions, including self-healing, adhesion, antibacterial activity, and suitable mechanical properties, are highly desirable for enhancing wound healing. In this study, a new class of multi-functional injectable self-healing cellulose-based hydrogels was synthesised using dynamic covalent acylhydrazone linkages for wound dressing. The carboxymethyl cellulose-graft-adipic dihydrazide (CMC-ADH)/4-Formylbenzoic acid-terminated poly(ethylene glycol) (PEG-FBA) (CMC-ADH/PEG-FBA) hydrogels have adjustable gelation time and excellent self-healing ability. In addition, drug release and in vitro antibacterial activities against Gram-positive and Gram-negative bacteria confirmed the sustained drug-release capacity of the hydrogels. Moreover, haemostasis and wound-healing effects were investigated using an in vivo haemorrhaging liver mouse model and a full-thickness skin defect model, and the results indicated that they not only promoted the wound-healing process but also presented excellent haemostatic effects. The CMC-ADH/PEG-FBA gels also exhibited good adhesion to irregular wounds and significantly enhanced angiogenic ability in vivo. This excellent wound-healing performance occurs because hydrogels can quickly stop bleeding, provide a moist and closed environment for the wound to prevent bacterial invasion, release ciprofloxacin (CIP), reduce inflammatory reactions, and promote wound tissue regeneration. In summary, the synthesised multi-functional gels are ideal candidates for treating haemorrhages and irregular wounds.

MALAYSIAN PROPERTY MARKET, THE STOCK MARKET AND MACROECONOMIC VARIABLES

This study examined the interactions and linkages between the property market, stock market, and macroeconomic variables. The stock market, in the long run, has a significant impact on property. Changes in house prices and stock markets have wealth and credit-price effects spilled over to economic growth. Both property and equity markets have a close dependency on income, inflation and monetary policy. The inference and dynamic relationship within asset markets have the capacity to explain the boom and bust cycles. The great potential lies with property and stock market interaction mechanisms to reflect economic conditions and as a source to enrich the present macroeconomic indicators. The Malaysian equity market was observed to be significantly co-integrated with the disaggregated real estate market (state level). The real estate market was mainly found to have a positive relationship with the stock market, GDP per capita (income) and consumer price index (CPI). However, real estate always had a negative relationship with interest rates. While real estate had a positive relationship with real GDP per capita in the long run, the relationship was not significant. This insignificance relationship covers all states and property types. The income coefficients were low and most of non-causality in the short run. This suggests a need for cautious from house price overheating. Price upsurge beyond the reach of the public may get caught with a sudden decline of the people’s affordability level. The impact of property price increase was higher than CPI (inflation). The inflation positive response on property is unusual as it normally follows the interest rate being negative. The shortage of affordable houses has pushed up prices. Inflation coefficients were mainly significant and much higher compared to stock and income coefficients. In short term dynamic linkages, bidirectional causality was detected between lending rates and the overall property market. This suggests a high temporal impact of monetary policy on the property market at the national level.

Dynamic linkages among energy consumption, urbanization and ecological footprint: empirical evidence from NARDL approach

PurposeThe primary purpose is to investigate the dynamic relationships among urbanization, energy use and environmental pollution in the context of India from 1971 to 2018. The paper also examines the validity of Environmental Kuznets Curve (EKC) hypothesis in the present Indian context.Design/methodology/approachThe study uses a nonlinear autoregressive distributed lag cointegration test (Shin et al., 2014) to investigate the dynamic relationship among the mentioned variables. The Wald test is also used to statistically check the presence of asymmetry. Additionally, the VECM test is applied to examine the causality among the variables.FindingsThis study documents that urbanization in India is good for environment in the long run, whereas energy consumption is bad for the environment. It also finds that positive and negative shocks of energy and urbanization exert asymmetric impacts on ecological footprint. Furthermore, the results could not validate the EKC hypothesis for India.Practical implicationsThe outcome of the study suggests designing an environmental policy which considers the nonlinearity of the investigated relationships and bearing in mind the use of comprehensive indicator like ecological footprint is equally important to address the wide-ranging problem of the environment. Policy reorientation towards the production and consumption of green energy, investment in research and development, and use of efficient technology is very crucial to achieve sustainable outcomes in the long run.Originality/valueIn this study, the researchers use the ‘ecological footprint’ variable to obtain a more accurate and comprehensive assessment of environmental deterioration. The mentioned dynamic relationships are investigated using an improved methodology of the NARDL model, which assumes the asymmetric impact of the explanatory variables on the response variable. The novelty of this study lies in examining the non-linear impact of urbanization and energy on ecological footprint which is inadequately addressed in the context of Indian economy.

Preparation and properties of lignin-based dual network hydrogel and its application in sensing

Ionic conductive hydrogels prepared from various biological macromolecules are ideal materials for the manufacture of human motion sensors from the perspective of resource regeneration and environmental sustainability. However, it is now difficult to develop conductive hydrogels including excellent self-healing and mechanical properties, mainly due to their inherent trade-off between dynamic cross-linked healing and stable cross-linked mechanical strength. In this work, alkali lignin-Polyvinyl alcohol-polyacrylic acid double network conductive hydrogels with high mechanical strength and good self-healing properties were prepared. We formed the primary network structure by hydrogen bonding interaction between polyvinyl alcohol, alkali lignin and polyacrylic acid, and the secondary network structure by coordination interaction with polyacrylic acid through the addition of Fe3+. The added lignin acts as a dynamic linkage bridge in a porous network mediated by multiple ligand bonds, imparting superior mechanical properties to the hydrogels. The relationships between the alkali lignin and iron ion dosage and the comprehensive properties of hydrogels (adhesion, antibacterial, self-healing, electrical conductivity and mechanical properties) were studied in detail. On this basis, the hydrogels explored the role of lignin in the regulation of hydrogels properties and revealed the self-healing and conductive mechanism.